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Zhang L, Herzog H. Important role of NPY-Y4R signalling in the dual control of feeding and physical activity. Neuropeptides 2024; 105:102425. [PMID: 38554699 DOI: 10.1016/j.npep.2024.102425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/14/2024] [Accepted: 03/16/2024] [Indexed: 04/02/2024]
Abstract
The control of feeding and physical activity is tightly linked and coordinated. However the underlying mechanisms are unclear. One of the major regulatory systems of feeding behaviour involves neuropeptide Y (NPY) signalling, with the signalling mediated through NPY Y4 receptor also known to influence activity. Here we show that mice globally lacking the Npy4r (Npy4r-/-) in the absence of access to a running wheel behaved WT-like with regards to food intake, energy expenditure, respiratory exchange ratio and locomotion regardless of being fed on a chow or high fat diet. Interestingly however, when given the access to a running wheel, Npy4r-/- mice while having a comparable locomotor activity, showed significantly higher wheel-running activity than WT, again regardless of dietary conditions. This higher wheel-running activity in Npy4r-/-mice arose from an increased dark-phase running time rather than changes in number of running bouts or the running speed. Consistently, energy expenditure was higher in Npy4r-/- than WT mice. Importantly, food intake was reduced in Npy4r-/-mice under wheel access condition which was due to decreased feeding bouts rather than changes in meal size. Together, these findings demonstrate an important role of Npy4r signalling in the dual control of feeding and physical activity, particularly in the form of wheel-running activity.
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Affiliation(s)
- Lei Zhang
- St Vincent's Centre for Applied Medical Research, School of Clinical Medicine, UNSW Medicine and Health, UNSW SYDNEY, NSW 2052, Australia.
| | - Herbert Herzog
- St Vincent's Centre for Applied Medical Research, School of Clinical Medicine, UNSW Medicine and Health, UNSW SYDNEY, NSW 2052, Australia
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2
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Vicuña L, Jaramillo-Fierro X, Cuenca PE, Godoy-Paucar B, Inga-Lafebre JD, Chavez Torres JL, García JF, Guaya D, Febres JD. Evaluation of the Effectiveness of Geogrids Manufactured from Recycled Plastics for Slope Stabilization-A Case Study. Polymers (Basel) 2024; 16:1151. [PMID: 38675071 PMCID: PMC11053962 DOI: 10.3390/polym16081151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/08/2024] [Accepted: 04/13/2024] [Indexed: 04/28/2024] Open
Abstract
This study aimed to investigate the sustainable use of recycled plastics, specifically polypropylene (PP) and high-density polyethylene (HDPE), in the manufacture of geogrids for geotechnical and civil engineering applications. Plastics were collected from a recycling center, specifically targeting containers used for food, cleaning products, and other domestic packaging items. These plastics were sorted according to the Möbius triangle classification system, with HDPE (#2) and PP (#5) being the primary categories of interest. The research methodologically evaluates the mechanical properties of PP/HDPE (0/100, 25/75, 50/50, 75/25 and 100/0% w/w) composites through tensile and flexural tests, exploring various compositions and configurations of geogrids. The results highlight the superiority of pure recycled HDPE processed into 1.3 mm thick laminated yarns and hot air welded for 20 to 30 s, exhibiting a deformation exceeding 60% in comparison to the PP/HDPE composites. Through SolidWorks® Simulation, it was shown that the adoption of a trigonal geogrid geometry optimizes force distribution and tensile strength, significantly improving slope stabilization efficiency. Based on the results obtained, a laboratory-scale prototype geogrid was developed using an extrusion process. The results underscore the importance of careful composite design and yarn configuration selection to achieve the desired mechanical properties and performance in geogrid applications. It emphasizes the potential of recycled plastics as a viable and environmentally friendly solution for stabilizing slopes, contributing to the reduction in plastic waste and promoting sustainable construction practices.
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Affiliation(s)
- Lenin Vicuña
- Departamento de Producción, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (L.V.); (P.E.C.); (J.D.I.-L.); (J.D.F.)
| | - Ximena Jaramillo-Fierro
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (J.F.G.); (D.G.)
| | - Paúl Eduardo Cuenca
- Departamento de Producción, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (L.V.); (P.E.C.); (J.D.I.-L.); (J.D.F.)
| | - Brenda Godoy-Paucar
- Carrera de Ingeniería Industrial, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador;
| | - Jorge Daniel Inga-Lafebre
- Departamento de Producción, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (L.V.); (P.E.C.); (J.D.I.-L.); (J.D.F.)
| | - Jose Luis Chavez Torres
- Departamento de Ingeniería Civil, Facultad de Ingenierías y Arquitectura, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador;
| | - Juan Fernando García
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (J.F.G.); (D.G.)
| | - Diana Guaya
- Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (J.F.G.); (D.G.)
| | - Juan Diego Febres
- Departamento de Producción, Facultad de Ciencias Exactas y Naturales, Universidad Técnica Particular de Loja, San Cayetano Alto, Loja 1101608, Ecuador; (L.V.); (P.E.C.); (J.D.I.-L.); (J.D.F.)
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Kitamura T. Useful biomarkers and clinical characteristics of post-pancreatitis diabetes mellitus ( PPDM). J Clin Endocrinol Metab 2024:dgae174. [PMID: 38501454 DOI: 10.1210/clinem/dgae174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 03/12/2024] [Indexed: 03/20/2024]
Affiliation(s)
- Tadahiro Kitamura
- Metabolic Signal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan
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Minh PS, Nguyen VT, Uyen TMT, Huy VQ, Le Dang HN, Nguyen VTT. Enhancing Amplification in Compliant Mechanisms: Optimization of Plastic Types and Injection Conditions. Polymers (Basel) 2024; 16:394. [PMID: 38337283 DOI: 10.3390/polym16030394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 01/19/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
This study surveys the impacts of injection parameters on the deformation rate of the injected flexure hinge made from ABS, PP, and HDPE. The flexure hinges are generated with different filling time, filling pressure, filling speed, packing time, packing pressure, cooling time, and melt temperature. The amplification ratio of the samples between different injection parameters and different plastic types is measured and compared to figure out the optimal one with a high amplification ratio. The results show that the relationship between the input and output data of the ABS, PP, and HDPE flexure hinges at different injection molding parameters is a linear relation. Changing the material or many injection molding parameters of the hinge could lead to a great impact on the hinge's performance. However, changing each parameter does not lead to a sudden change in the input and output values. Each plastic material has different optimal injection parameters and displacement behaviors. With the ABS flexure hinge, the filling pressure case has the greatest amplification ratio of 8.81, while the filling speed case has the lowest value of 4.81. With the optimal injection parameter and the input value of 105 µm, the ABS flexure hinge could create a maximum average output value of 736.6 µm. With the PP flexure hinge, the melt temperature case achieves the greatest amplification ratio of 6.73, while the filling speed case has the lowest value of 4.1. With the optimal injection parameter and the input value of 128 µm, the PP flexure hinge could create a maximum average output value of 964.8 µm. The average amplification ratio values of all injection molding parameters are 6.85, 5.41, and 4.01, corresponding to ABS, PP, and HDPE flexure hinges. Generally, the ABS flexure hinge has the highest amplification ratios, followed by the PP flexure hinge. The HDPE flexure hinge has the lowest amplification ratios among these plastic types. With the optimal injection parameter and the input value of 218 µm, the HDPE flexure hinge could create a maximum average output value of 699.8 µm. The results provide more insight into plastic flexure hinges and broaden their applications by finding the optimal injection parameters and plastic types.
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Affiliation(s)
- Pham Son Minh
- Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology and Education, Ho Chi Minh City 71307, Vietnam
| | - Van-Thuc Nguyen
- Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology and Education, Ho Chi Minh City 71307, Vietnam
| | - Tran Minh The Uyen
- Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology and Education, Ho Chi Minh City 71307, Vietnam
| | - Vu Quang Huy
- Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology and Education, Ho Chi Minh City 71307, Vietnam
| | - Hai Nguyen Le Dang
- Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology and Education, Ho Chi Minh City 71307, Vietnam
| | - Van Thanh Tien Nguyen
- Faculty of Mechanical Engineering, Industrial University of Ho Chi Minh City, Nguyen Van Bao Street, Ward 4, Go Vap District, Ho Chi Minh City 70000, Vietnam
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Hanna SM, Rabea HM, Abdelrahim MEA, Mahmoud HB. Safety and efficacy of candesartan versus valsartan combined with amlodipine on peripheral and central blood pressure. Hipertens Riesgo Vasc 2024; 41:17-25. [PMID: 38418298 DOI: 10.1016/j.hipert.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/12/2023] [Accepted: 11/29/2023] [Indexed: 03/01/2024]
Abstract
INTRODUCTION "Amlodipine/valsartan" or "amlodipine/candesartan" combinations represent two effective antihypertensive agents with complementary mechanisms of action. Nevertheless, a study has yet to be done to evaluate the effect of amlodipine/candesartan on central blood pressure and compare it with amlodipine/valsartan combination. To see how "amlodipine plus candesartan combination" reduces peripheral and central blood pressure compared to the most studied combination, "amlodipine plus valsartan". MATERIAL AND METHODS Eighty-six patients were randomized in an open-label, prospective study by 1:1 ratio to two groups. Group I (n=42) received the amlodipine and valsartan combination, and group II (n=44) received the amlodipine and candesartan combination. Peripheral and central blood pressure (CBP) was measured at baseline, at 6 and 12 weeks of follow-up. DISCUSSION Both treatment groups reduced peripheral systolic, diastolic, and mean blood pressure. There was no significant difference between and within both groups. The amlodipine/candesartan combination showed more reduction in peripheral systolic blood pressure (PSBP) after 12 weeks of treatment (p=<0.001). Both groups decreased CBP without significant differences between groups. The amlodipine/candesartan combination showed additional efficacy in decreasing CSBP after 12 weeks (p=<0.001). The two treatment groups did not exert significant efficacy in lowering heart rate (HR) and augmentation index% (AIx%). CONCLUSION To conclude, the amlodipine 10mg/candesartan 16mg combination was non-inferior to the amlodipine 10mg/valsartan 160mg combination in terms of reducing peripheral and CBP over time.
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Affiliation(s)
- S M Hanna
- Clinical Pharmacist, Cardiovascular Department, Beni-Suef University Hospital, Egypt.
| | - H M Rabea
- Clinical Pharmacy Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - M E A Abdelrahim
- Clinical Pharmacy Department, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - H B Mahmoud
- Prof. of Cardiology, Beni-Suef University Hospital, Beni-Suef, Egypt
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Lin F, Zhang M, Zhao T, Zhang Y, Ning D, Cui W, Li Y, Chen X, Luo J. Exploitation of a New Nucleating Agent by Molecular Structure Modification of Aryl Phosphate and Its Effect on A pplication Properties of the Polypropylene. Polymers (Basel) 2023; 15:4730. [PMID: 38139981 PMCID: PMC10747455 DOI: 10.3390/polym15244730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/08/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
In this work, a novel α-nucleating agent (NA) for polypropylene (PP) termed APAl-3C-12Li was prepared and evaluated compared with the commercially available type NA-21. For the synthesis of the organophosphate-type NA (APAl-3C), the -OH group of the acid part of NA-21 was substituted by the isopropoxy group. The structure of APAl-3C was analyzed by spectroscopy and element analysis, the results of which were consistent with the theoretical molecular formula. APAl-3C's thermal stability was studied by differential scanning calorimetry (DSC) and thermogravimetry (TG), which showed only weak mass loss below 230 °C, meaning that it would not decompose during the processing of PP. The APAl-3C-12Li was used as a novel nucleating agent, studying its effects on crystallization, microstructure, mechanical and optical properties. Tests were performed in a PP random copolymer at different contents, in comparison to the commercial NA-21. The composite with 0.5 wt% APAl-3C-12Li has a similar crystallization temperature of 118.8 °C as with the addition of 0.5 wt% NA-21. An advantage is that the composite with the APAl-3C-12Li has a lower haze value of 9.3% than the counterpart with NA-21. This is due to the weaker polarity of APAl-3C-12Li after the introduction of methyl and better uniform dispersion in the PP matrix, resulting in stronger improvement of optical and mechanical properties.
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Affiliation(s)
- Fuhua Lin
- School of Traffic Engineering, Shanxi Vocational University of Engineering Science and Technology, Jinzhong 030619, China
- School of Materials Science and Engineering, North University of China, Taiyuan 030024, China;
| | - Mi Zhang
- Shanxi Province Institute of Chemical Industry (Co., Ltd.), Jinzhong 030621, China;
| | - Tianjiao Zhao
- School of Chemical Engineering and Technology, Taiyuan University of Science and Technology, Taiyuan 030024, China; (T.Z.); (Y.Z.); (D.N.); (W.C.)
| | - Yanli Zhang
- School of Chemical Engineering and Technology, Taiyuan University of Science and Technology, Taiyuan 030024, China; (T.Z.); (Y.Z.); (D.N.); (W.C.)
| | - Dingyi Ning
- School of Chemical Engineering and Technology, Taiyuan University of Science and Technology, Taiyuan 030024, China; (T.Z.); (Y.Z.); (D.N.); (W.C.)
| | - Wenju Cui
- School of Chemical Engineering and Technology, Taiyuan University of Science and Technology, Taiyuan 030024, China; (T.Z.); (Y.Z.); (D.N.); (W.C.)
| | - Yingchun Li
- School of Materials Science and Engineering, North University of China, Taiyuan 030024, China;
| | - Xinde Chen
- Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China;
| | - Jun Luo
- Guangzhou Fibre Product Testing and Research Institute, Guangzhou 510220, China
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Jiang C, Almuhtaram H, McKie MJ, Andrews RC. Assessment of Biofilm Growth on Microplastics in Freshwaters Using a Passive Flow-Through System. Toxics 2023; 11:987. [PMID: 38133388 PMCID: PMC10748376 DOI: 10.3390/toxics11120987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/24/2023] [Accepted: 12/01/2023] [Indexed: 12/23/2023]
Abstract
Biofilms that colonize on the surface of microplastics (MPs) in freshwaters may pose a potential health risk. This study examined factors that influence MP-associated biofilm growth, including polymer type, degree of weathering, and source water quality. Weathered MPs produced in-lab were employed in biofilm trials conducted on site using a passive flow-through system with raw water at drinking water treatment facility intakes. Adenosine triphosphate (ATP) was used to quantify biofilm abundance; biofilm composition was assessed via metagenomic sequencing. Biofilm growth was observed on all polymer types examined and most prevalent on polyvinyl chloride (PVC), where ATP levels were 6 to 12 times higher when compared to other polymers. Pathogen-containing species including Salmonella enterica and Escherichia coli were present on all polymers with relative abundance up to 13.7%. S. enterica was selectively enriched on weathered MPs in specific water matrices. These findings support the need to research the potential accumulation of pathogenic organisms on microplastic surfaces.
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Affiliation(s)
| | - Husein Almuhtaram
- Department of Civil and Mineral Engineering, University of Toronto, 35 St. George Street, Toronto, ON M5S 1A4, Canada
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Main P, Petersmann S, Wild N, Feuchter M, Duretek I, Edeleva M, Ragaert P, Cardon L, Lucyshyn T. Impact of Multiple Reprocessing on Properties of Polyhydroxybutyrate and Polypropylene. Polymers (Basel) 2023; 15:4126. [PMID: 37896370 PMCID: PMC10611211 DOI: 10.3390/polym15204126] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/12/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Biobased plastics have the potential to be sustainable, but to explore their circularity further, current end-of-life options need to be broadened. Mechanical recycling is one of the most accepted methods to bring back plastics into the loop. Polyhydroxybutyrates (PHBs) are biobased and biodegradable in nature with promising properties and varied applications in the market. This study focuses on their potential for mechanical recycling by multiple extrusion cycles (E1-E5) and multi-faceted characterization of the virgin (V) and reprocessed materials from E1 to E5. The behavior is compared to polypropylene (PP) as a reference with a similar property profile, which has also been reprocessed five times. The thermal properties of both series showed a stable melting point and thermal decomposition temperature from thermal analyses (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)). However, a steady increase in the degree of crystallinity was observed which could counterbalance the decrease in molecular weight due to repeated extrusion measured by gel permeation chromatography and resulted in similar values of tensile strength across the cycles. The strain at break was impacted after the first extrusion, but no significant change was observed thereafter; the same was observed for impact strength. Even in scanning electron microscopy (SEM) images, virgin and E5 samples appeared similar, showing the stability of morphological characteristics. Fourier transform infrared spectroscopy (FTIR) results revealed that no new groups are being formed even on repeated processing. The deviation between the PHB and PP series was more predominant in the melt mass flow rate (MFR) and rheology studies. There was a drastic drop in the MFR values in PHB from virgin to E5, whereas not much difference was observed for PP throughout the cycles. This observation was corroborated by frequency sweeps conducted with the parallel plate method. The viscosity dropped from virgin to E1 and E2, but from E3 to E5 it presented similar values. This was in contrast to PP, where all the samples from virgin to E5 had the same values of viscosity. This paper highlights the possibilities of mechanical recycling of PHB and explains why future work with the addition of virgin material and other additives is an area to be explored.
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Affiliation(s)
- Priyanka Main
- Polymer Processing, Montanuniversitaet Leoben, Otto-Gloeckel-Straße 2, 8700 Leoben, Austria;
- Faculty of Engineering and Architecture, Centre for Polymer and Material Technologies, Ghent University, Technologiepark Zwijnaarde 130 (Zone C3), 9052 Zwijnaarde, Belgium; (M.E.); (L.C.)
- Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium;
| | - Sandra Petersmann
- Materials Science and Testing of Polymers, Montanuniversitaet Leoben, Otto Gloeckel-Straße 2, 8700 Leoben, Austria; (S.P.); (N.W.); (M.F.)
| | - Nadine Wild
- Materials Science and Testing of Polymers, Montanuniversitaet Leoben, Otto Gloeckel-Straße 2, 8700 Leoben, Austria; (S.P.); (N.W.); (M.F.)
| | - Michael Feuchter
- Materials Science and Testing of Polymers, Montanuniversitaet Leoben, Otto Gloeckel-Straße 2, 8700 Leoben, Austria; (S.P.); (N.W.); (M.F.)
| | - Ivica Duretek
- Polymer Processing, Montanuniversitaet Leoben, Otto-Gloeckel-Straße 2, 8700 Leoben, Austria;
| | - Mariya Edeleva
- Faculty of Engineering and Architecture, Centre for Polymer and Material Technologies, Ghent University, Technologiepark Zwijnaarde 130 (Zone C3), 9052 Zwijnaarde, Belgium; (M.E.); (L.C.)
| | - Peter Ragaert
- Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium;
| | - Ludwig Cardon
- Faculty of Engineering and Architecture, Centre for Polymer and Material Technologies, Ghent University, Technologiepark Zwijnaarde 130 (Zone C3), 9052 Zwijnaarde, Belgium; (M.E.); (L.C.)
| | - Thomas Lucyshyn
- Polymer Processing, Montanuniversitaet Leoben, Otto-Gloeckel-Straße 2, 8700 Leoben, Austria;
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Schefer RB, Armanious A, Mitrano DM. Eco-Corona Formation on Plastics: Adsorption of Dissolved Organic Matter to Pristine and Photochemically Weathered Polymer Surfaces. Environ Sci Technol 2023; 57:14707-14716. [PMID: 37722069 DOI: 10.1021/acs.est.3c04180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Plastic fate in freshwater systems is dependent on particle size, morphology, and physicochemical surface properties (e.g., charge, surface roughness, and hydrophobicity). Environmental aging processes, such as photochemical weathering and eco-corona formation due to dissolved organic matter (DOM) adsorption on plastic surfaces, can alter their physicochemical properties, affecting fate and transport. While plastic aging has been studied from a materials science perspective, its specific implications in environmental contexts remain less understood. Although photochemical weathering and eco-corona formation occur simultaneously in the environment, in this work, we systematically assessed the effects of photochemical weathering on the physicochemical properties of polymers (polyethylene, polypropylene, polyethylene terephthalate, and polystyrene) and how this influences the adsorption of DOMs (Suwannee River humic acid, fulvic acid, and natural organic matter) relative to pristine polymers. Pristine polymers initially had different and distinct physicochemical surface properties, but upon aging, they became more similar in terms of surface properties. Photochemical weathering resulted in a decrease in polymer film thickness, an increase in surface roughness, and hydrophilicity. DOM adlayers on the polymer surfaces resulted in more comparable wettability, effectively masking the initial polymer properties. Collectively, this study explores the physiochemical changes polymers undergo in laboratory studies mimicking environmental conditions. Understanding these changes is the initial step to rationalizing and predicting processes and interactions such as heteroaggregation that dictate the fate of plastics in the environment.
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Affiliation(s)
- Roman B Schefer
- Environmental Systems Science Department, ETH Zürich, Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Antonius Armanious
- Department of Health Science and Technology, ETH Zürich, Universitätstrasse 2, 8092 Zurich, Switzerland
| | - Denise M Mitrano
- Environmental Systems Science Department, ETH Zürich, Universitätstrasse 16, 8092 Zurich, Switzerland
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Barbosa MLS, Costa RDFS, Silva FJG, Sousa SR, Pinto AG, Ferreira BO. Studying the Degradation of Three Polymers under Different Chlorine Concentrations and Exposure Times. Polymers (Basel) 2023; 15:3931. [PMID: 37835981 PMCID: PMC10574910 DOI: 10.3390/polym15193931] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023] Open
Abstract
Due to chlorine's ability to kill bacteria and fungi through a chemical reaction, chlorine solutions are commonly used to clean and disinfect numerous public facilities, although these actions are also dependent to the equipment present in those facilities. Accordingly, the interest in studying its effect when in contact with different materials is obvious. This study was carried out through accelerated degradation tests and various analysis methods (optical microscope, scanning electron microscope, and tensile tests). The objective was to observe the wear presented by three polymeric materials, polyvinyl chloride (PVC), high-density polyethylene (HDPE), and polypropylene (PP), when exposed to chlorine's action in swimming pools and drinking water treatment plants. The resulting effect depends on the chlorine content and the type of contact between the chemical agent and the material. The aim was to select the material less likely to be affected by chlorine through tests and analyses, allowing a longer component life. The use of certain more resistant polymeric materials can drastically reduce maintenance, reducing fundamental factors such as costs, the downtime of municipal facilities, and also the risk to public health. It was concluded that PVC has the most stable behaviour overall when in contact with chlorine solutions.
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Affiliation(s)
- Marta L. S. Barbosa
- ISEP, Polytechnic of Porto, 4249-015 Porto, Portugal; (M.L.S.B.); (R.D.F.S.C.); (A.G.P.); (B.O.F.)
| | - Rúben D. F. S. Costa
- ISEP, Polytechnic of Porto, 4249-015 Porto, Portugal; (M.L.S.B.); (R.D.F.S.C.); (A.G.P.); (B.O.F.)
| | - Francisco J. G. Silva
- ISEP, Polytechnic of Porto, 4249-015 Porto, Portugal; (M.L.S.B.); (R.D.F.S.C.); (A.G.P.); (B.O.F.)
- INEGI—Institute of Science and Innovation in Mechanical and Industrial Engineering, 4200-465 Porto, Portugal
| | - Susana R. Sousa
- i3S—Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal;
- INEB—Instituto de Engenharia Biomédica, Universidade do Porto, 4200-135 Porto, Portugal
| | - Arnaldo G. Pinto
- ISEP, Polytechnic of Porto, 4249-015 Porto, Portugal; (M.L.S.B.); (R.D.F.S.C.); (A.G.P.); (B.O.F.)
| | - Bruno O. Ferreira
- ISEP, Polytechnic of Porto, 4249-015 Porto, Portugal; (M.L.S.B.); (R.D.F.S.C.); (A.G.P.); (B.O.F.)
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Wieczorowski M, Pereira A, Prado T, Lopez-Blanco A, Grochalski K, Grabon W, Perez MC. Tomographic and Tension Analysis of Polypropylene Reinforced with Carbon Fiber Fabric by Injection Molding. Materials (Basel) 2023; 16:6231. [PMID: 37763511 PMCID: PMC10532608 DOI: 10.3390/ma16186231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/07/2023] [Accepted: 09/13/2023] [Indexed: 09/29/2023]
Abstract
The use of thermoplastic materials has had significant growth in recent years. However, with great mechanical requirements, thermoplastics have limitations to their use. To improve these restrictions, these materials are reinforced to obtain better properties. Polypropylene is one of the most versatile polymers and is used in almost all modern industries. Thus, the aim of this study is to create composite materials that offer performance for various industrial fields using carbon fiber fabric reinforcement, which is an inexpensive material widely used by the aerospace, automotive, and marine industries. The samples are produced by the over-injection molding of polypropylene. The investigation is focused on the impact of two critical control parameters in the injection molding process: temperature and pressure. Twelve experiments have therefore been considered, taking into account the combination of three factors: the presence or absence of carbon fiber fabric reinforcement, three levels of temperature (200 °C, 220 °C, and 240 °C), and two injection pressures (5000 kPa and 10,000 kPa). To evaluate the influence of these factors, three analyses were carried out: first, on the samples' shrinkage using a portable metrology-grade 3D laser scanner; second, on the internal defects using computed tomography (CT); and third, on the mechanical properties with tensile tests. From the results obtained, it is observed that the mold shrinkage fell slightly when PP samples were reinforced with carbon fiber, with both materials (PP and carbon-fiber-reinforced PP) having linear behavior with temperature. It is also noticed that polypropylene behaves as a crystalline material when processed at higher temperatures and pressures. From tests on the mechanical properties, it is concluded that the mean yield strength of PP-CF for injection temperatures of 220 °C and 240 °C represents an increase of 43% compared to the non-reinforced material.
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Affiliation(s)
- Michal Wieczorowski
- Faculty of Mechanical Engineering, Poznan University of Technology, Piotrowo Street 3, 60-965 Poznan, Poland;
| | - Alejandro Pereira
- Manufacturing Engineering Group (GEF) EEI Campus Lagoas, Universidade de Vigo, 36310 Vigo, Spain; (A.P.); (T.P.); (A.L.-B.)
| | - Teresa Prado
- Manufacturing Engineering Group (GEF) EEI Campus Lagoas, Universidade de Vigo, 36310 Vigo, Spain; (A.P.); (T.P.); (A.L.-B.)
| | - Alberto Lopez-Blanco
- Manufacturing Engineering Group (GEF) EEI Campus Lagoas, Universidade de Vigo, 36310 Vigo, Spain; (A.P.); (T.P.); (A.L.-B.)
| | - Karol Grochalski
- Faculty of Mechanical Engineering, Poznan University of Technology, Piotrowo Street 3, 60-965 Poznan, Poland;
| | - Wieslaw Grabon
- Faculty of Mechanical Engineering and Aeronautics, Rzeszow University of Technology, Powstancow Warszawy 8 Street, 35-959 Rzeszow, Poland;
| | - M. Consuelo Perez
- ENCOMAT, Centro de Investigación en Tecnologías, Energía y Procesos Industriales, Universidade de Vigo, 36310 Vigo, Spain;
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12
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Song L, Cong F, Wang W, Ren J, Chi W, Yang B, Zhang Q, Li Y, Li X, Wang Y. The Effect of Functionalized SEBS on the Properties of PP/SEBS Blends. Polymers (Basel) 2023; 15:3696. [PMID: 37765550 PMCID: PMC10535659 DOI: 10.3390/polym15183696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/29/2023] [Accepted: 09/04/2023] [Indexed: 09/29/2023] Open
Abstract
Styrene (St) was used as comonomer and glycidyl methacrylate (GMA) as grafting monomer to prepare SEBS-g-(GMA-co-St) graft copolymers via melt grafting. Then, the graft copolymers were employed as a compatibilizer for melt blending polypropylene (PP) and hydrogenated styrene-butadiene-styrene (SEBS) triblock copolymers. The effects of the amount of GMA in the graft copolymers on thermal properties, rheology, crystallization, optical and mechanical properties, and microstructure of the blends were investigated. The results show that GMA and St were successfully grafted onto SEBS. The GMA amount in the graft copolymer significantly influenced the comprehensive properties of PP/SEBS/SEBS-g-(GMA-co-St) blends. The epoxy groups of GMA reacted with PP and SEBS, forming interfacial chemical bonds, thereby enhancing the compatibility between PP and SEBS to varying extents. After introducing SEBS-g-(GMA-co-St) into PP/SEBS blends, crystallinity decreased, crystal size increased while transmittance remained above 91% with rising GMA amount in the graft copolymers, indicating excellent optical properties. Notched impact strength and elongation at break of the blends showed a trend of first increasing and then decreasing with increased amounts of GMA in the graft copolymers. When the amount of GMA in the graft copolymers was 3 wt%, the blends exhibited optimal toughness with notched impact strength and elongation at break of 30,165.82 J/m2 and 1445.40%, respectively. This was attributed to the tightest dispersion interface adhesion and maximum matrix plastic deformation, consistent with the mechanical performance results.
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Affiliation(s)
- Lixin Song
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Fei Cong
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Wei Wang
- BatteroTech Co., Ltd., Shanghai 201417, China
| | - Jiannan Ren
- AVIC Shenyang Aircraft Corporation, Shenyang 110850, China
| | - Weihan Chi
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Bing Yang
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Qian Zhang
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Yongchao Li
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Xianliang Li
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
| | - Yuanxia Wang
- Polymer High Functional Film Engineering Research Center of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China
- College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China
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13
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Naik R, Allu SG, Purnima D. PP/Jute Fiber Composites: Effect of Biological Route of Surface Treatment and Content of Jute on Composites. Appl Biochem Biotechnol 2023:10.1007/s12010-023-04589-5. [PMID: 37335456 DOI: 10.1007/s12010-023-04589-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/26/2023] [Indexed: 06/21/2023]
Abstract
Jute as a fiber has many applications. It is also used in polymers as reinforcement due to its good tensile properties. However, when it is used in polymer matrices, there is a lack of adhesion between the polymer and jute fiber. Surface treatment of fiber using chemicals has been found to improve the properties. However, the use of chemicals causes environmental pollution, when these chemicals are discharged into the environment. In this paper, an attempt has been made to study the effect of the biological route to surface treat the jute fiber. The effect of surface treatment on the morphology of jute was examined. A comparative study was on the crystalline, thermal, and tensile fracture morphology of the composites to understand the effect of the incorporation of untreated and treated jute fibers in polypropylene (PP).
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Affiliation(s)
- Rudresh Naik
- Department of Chemical Engineering, Birla Institute of Technology and Science, Jawaharnagar, Shamirpet Mandal, Hyderabad, Telangana, 500078, India
| | - Sai Gowtham Allu
- Department of Chemical Engineering, Birla Institute of Technology and Science, Jawaharnagar, Shamirpet Mandal, Hyderabad, Telangana, 500078, India
| | - D Purnima
- Department of Chemical Engineering, Birla Institute of Technology and Science, Jawaharnagar, Shamirpet Mandal, Hyderabad, Telangana, 500078, India.
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14
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Sánchez ML, Rodríguez FD, Coveñas R. Neuropeptide Y Peptide Family and Cancer: Antitumor Therapeutic Strategies. Int J Mol Sci 2023; 24:9962. [PMID: 37373115 DOI: 10.3390/ijms24129962] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 05/30/2023] [Accepted: 06/07/2023] [Indexed: 06/29/2023] Open
Abstract
Currently available data on the involvement of neuropeptide Y (NPY), peptide YY (PYY), and pancreatic polypeptide (PP) and their receptors (YRs) in cancer are updated. The structure and dynamics of YRs and their intracellular signaling pathways are also studied. The roles played by these peptides in 22 different cancer types are reviewed (e.g., breast cancer, colorectal cancer, Ewing sarcoma, liver cancer, melanoma, neuroblastoma, pancreatic cancer, pheochromocytoma, and prostate cancer). YRs could be used as cancer diagnostic markers and therapeutic targets. A high Y1R expression has been correlated with lymph node metastasis, advanced stages, and perineural invasion; an increased Y5R expression with survival and tumor growth; and a high serum NPY level with relapse, metastasis, and poor survival. YRs mediate tumor cell proliferation, migration, invasion, metastasis, and angiogenesis; YR antagonists block the previous actions and promote the death of cancer cells. NPY favors tumor cell growth, migration, and metastasis and promotes angiogenesis in some tumors (e.g., breast cancer, colorectal cancer, neuroblastoma, pancreatic cancer), whereas in others it exerts an antitumor effect (e.g., cholangiocarcinoma, Ewing sarcoma, liver cancer). PYY or its fragments block tumor cell growth, migration, and invasion in breast, colorectal, esophageal, liver, pancreatic, and prostate cancer. Current data show the peptidergic system's high potential for cancer diagnosis, treatment, and support using Y2R/Y5R antagonists and NPY or PYY agonists as promising antitumor therapeutic strategies. Some important research lines to be developed in the future will also be suggested.
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Affiliation(s)
- Manuel Lisardo Sánchez
- Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla and León (INCYL), University of Salamanca, 37008 Salamanca, Spain
| | - Francisco D Rodríguez
- Department of Biochemistry and Molecular Biology, Faculty of Chemical Sciences, University of Salamanca, 37008 Salamanca, Spain
- Group GIR-USAL: BMD (Bases Moleculares del Desarrollo), University of Salamanca, 37008 Salamanca, Spain
| | - Rafael Coveñas
- Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla and León (INCYL), University of Salamanca, 37008 Salamanca, Spain
- Group GIR-USAL: BMD (Bases Moleculares del Desarrollo), University of Salamanca, 37008 Salamanca, Spain
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15
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Xian ZN, Yin CF, Zheng L, Zhou NY, Xu Y. Biodegradation of additive-free polypropylene by bacterial consortia enriched from the ocean and from the gut of Tenebrio molitor larvae. Sci Total Environ 2023:164721. [PMID: 37301383 DOI: 10.1016/j.scitotenv.2023.164721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 05/15/2023] [Accepted: 06/05/2023] [Indexed: 06/12/2023]
Abstract
Accumulation of highly recalcitrant PP wastes has caused a serious environmental pollution. We evaluated the biodegradation of two types of additive-free PP polymers by microbial degraders from different environments. Two bacterial consortia, designated as PP1M and PP2G, were enriched from the ocean and from the guts of Tenebrio molitor larvae. Both consortia were able to utilize each of two different additive-free PP plastics with relatively low molecular weights (low molecular weight PP powder and amorphous PP pellets) as the sole carbon source for growth. After a 30-day incubation, several plastic characterization methods, including high-temperature gel permeation chromatography, scanning electron microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry, were used to characterize the PP samples. The bio-treated PP powder was covered with tight biofilms and extracellular secretions with significantly increased hydroxyl and carbonyl groups and slightly decreased methyl groups. This suggested that degradation and oxidation had occurred. The altered molecular weights and the increased melting enthalpy and average crystallinity of the bio-treated PP samples all suggested that both consortia preferred to depolymerize and degrade the fractions with molecular weights of <34 kDa and the amorphous phase fractions of the two types of PP. Furthermore, low molecular weight PP powder was more susceptible to bacterial degradation compared to amorphous PP pellets. This study provides a unique example of different types of additive-free PP degradation by different culturable bacteria from the ocean and insect guts as well as a feasibility of PP waste removal in different environments.
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Affiliation(s)
- Zhuo-Ning Xian
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 20040, China
| | - Chao-Fan Yin
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 20040, China
| | - Li Zheng
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 20040, China
| | - Ying Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 20040, China.
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16
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Kalmykov D, Shirokikh S, Grushevenko EA, Legkov SA, Bondarenko GN, Anokhina TS, Molchanov S, Bazhenov SD. Stability of Porous Polymeric Membranes in Amine Solvents for Membrane Contactor A pplications. Membranes (Basel) 2023; 13:544. [PMID: 37367748 DOI: 10.3390/membranes13060544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/12/2023] [Accepted: 05/22/2023] [Indexed: 06/28/2023]
Abstract
Membrane gas-liquid contactors have great potential to meet the challenges of amine CO2 capture. In this case, the most effective approach is the use of composite membranes. However, to obtain these, it is necessary to take into account the chemical and morphological resistance of membrane supports to long-term exposure to amine absorbents and their oxidative degradation products. In this work, we studied the chemical and morphological stability of a number of commercial porous polymeric membranes exposed to various types of alkanolamines with the addition of heat-stable salt anions as a model of real industrial CO2 amine solvents. The results of the physicochemical analysis of the chemical and morphological stability of porous polymer membranes after exposure to alkanolamines, their oxidative degradation products, and oxygen scavengers were presented. According to the results of studies by FTIR spectroscopy and AFM, a significant destruction of porous membranes based on polypropylene (PP), polyvinylidenefluoride (PVDF), polyethersulfone (PES) and polyamide (nylon, PA) was revealed. At the same time, the polytetrafluoroethylene (PTFE) membranes had relatively high stability. On the basis of these results, composite membranes with porous supports that are stable in amine solvents can be successfully obtained to create liquid-liquid and gas-liquid membrane contactors for membrane deoxygenation.
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Affiliation(s)
- Denis Kalmykov
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Sergey Shirokikh
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Evgenia A Grushevenko
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Sergey A Legkov
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Galina N Bondarenko
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Tatyana S Anokhina
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Sergey Molchanov
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
| | - Stepan D Bazhenov
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Prospekt, 119991 Moscow, Russia
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17
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Murariu M, Paint Y, Murariu O, Laoutid F, Dubois P. Engineering Polypropylene-Calcium Sulfate (Anhydrite II) Composites: The Key Role of Zinc Ionomers via Reactive Extrusion. Polymers (Basel) 2023; 15. [PMID: 36850083 DOI: 10.3390/polym15040799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 01/30/2023] [Accepted: 01/31/2023] [Indexed: 02/08/2023] Open
Abstract
Polypropylene (PP) is one of the most versatile polymers widely used in packaging, textiles, automotive, and electrical applications. Melt blending of PP with micro- and/or nano-fillers is a common approach for obtaining specific end-use characteristics and major enhancements of properties. The study aims to develop high-performance composites by filling PP with CaSO4 β-anhydrite II (AII) issued from natural gypsum. The effects of the addition of up to 40 wt.% AII into PP matrix have been deeply evaluated in terms of morphology, mechanical and thermal properties. The PP-AII composites (without any modifier) as produced with internal mixers showed enhanced thermal stability and stiffness. At high filler loadings (40% AII), there was a significant decrease in tensile strength and impact resistance; therefore, custom formulations with special reactive modifiers/compatibilizers (PP functionalized/grafted with maleic anhydride (PP-g-MA) and zinc diacrylate (ZnDA)) were developed. The study revealed that the addition of only 2% ZnDA (able to induce ionomeric character) leads to PP-AII composites characterized by improved kinetics of crystallization, remarkable thermal stability, and enhanced mechanical properties, i.e., high tensile strength, rigidity, and even rise in impact resistance. The formation of Zn ionomers and dynamic ionic crosslinks, finer dispersion of AII microparticles, and better compatibility within the polyolefinic matrix allow us to explain the recorded increase in properties. Interestingly, the PP-AII composites also exhibited significant improvements in the elastic behavior under dynamic mechanical stress and of the heat deflection temperature (HDT), thus paving the way for engineering applications. Larger experimental trials have been conducted to produce the most promising composite materials by reactive extrusion (REx) on twin-screw extruders, while evaluating their performances through various methods of analysis and processing.
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18
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Epure EL, Cojocaru FD, Aradoaei M, Ciobanu RC, Dodi G. Exploring the Surface Potential of Recycled Polyethylene Terephthalate Composite Su pports on the Collagen Contamination Level. Polymers (Basel) 2023; 15:polym15030776. [PMID: 36772077 PMCID: PMC9921895 DOI: 10.3390/polym15030776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/17/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
With a significant number of features (namely being multipurpose, inexpensive and durable), thermoplastic polymers, most often named plastics, are part of our daily routine, with an increasing production over the last decade. Among them, polyethylene terephthalate (PET), high-density polyethylene (HDPE) and polypropylene (PP) are distinguished as the five most commonly used plastics in various fields, mainly in the packaging industry. Even if it is difficult to imagine the world without plastics, the boosted plastic assembly comes with huge plastic waste, creating a number of challenges, as the most important threat for our environment, but also opportunities for recycling. Currently, a special attention is dedicated on how to improve the current recycling methods or to find new ones, since the quality of recycled plastics and potential chemical or biological contaminations are two problematic aspects. Understanding the properties of each thermoplastic polymer and the interaction with possible contaminants may be the key for an efficient recycling process. The aim of this paper was to evaluate the surface behaviour of different composite supports based on recycled PET before and after interaction with collagen (used as a biological contaminant). The surface contamination bias of PET supports was studied through different techniques: scanning electron microscopy (SEM), water uptake through swelling studies, contact angle measurements and attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR).
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Affiliation(s)
- Elena-Luiza Epure
- Faculty of Chemical Engineering and Environmental Protection, Gheorghe Asachi Technical University, Mangeron Bd., 700454 Iasi, Romania
| | - Florina Daniela Cojocaru
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 9-13 M. Kogalniceanu Street, 700454 Iasi, Romania
- Faculty of Medical Bioengineering, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 9-13 M. Kogalniceanu Street, 700454 Iasi, Romania
| | - Mihaela Aradoaei
- Electrical Engineering Faculty, Gheorghe Asachi Technical University of Iasi, 67 Prof. Dimitrie Mangeron Bd., 700050 Iasi, Romania
- ALL GREEN SRL, 8 G. Cosbuc Street, 700470 Iasi, Romania
- Correspondence: (M.A.); (G.D.)
| | - Romeo Cristian Ciobanu
- Electrical Engineering Faculty, Gheorghe Asachi Technical University of Iasi, 67 Prof. Dimitrie Mangeron Bd., 700050 Iasi, Romania
- ALL GREEN SRL, 8 G. Cosbuc Street, 700470 Iasi, Romania
| | - Gianina Dodi
- Advanced Research and Development Center for Experimental Medicine, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 9-13 M. Kogalniceanu Street, 700454 Iasi, Romania
- Faculty of Medical Bioengineering, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 9-13 M. Kogalniceanu Street, 700454 Iasi, Romania
- Correspondence: (M.A.); (G.D.)
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19
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Giaganini G, Cifelli M, Biagini D, Ghimenti S, Corti A, Castelvetro V, Domenici V, Lomonaco T. Multi-Analytical A pproach to Characterize the Degradation of Different Types of Microplastics: Identification and Quantification of Released Organic Compounds. Molecules 2023; 28:molecules28031382. [PMID: 36771048 PMCID: PMC9919824 DOI: 10.3390/molecules28031382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023] Open
Abstract
Microplastics and nanoplastics represent one of the major environmental issues nowadays due to their ubiquitous presence on Earth, and their high potential danger for living systems, ecosystems, and human life. The formation of both microplastics and nanoplastics strongly depends on both the type of pristine materials and the degradation processes related to biological and/or abiotic conditions. The aim of this study is to investigate the effect of two of the most relevant abiotic parameters, namely temperature and light, taken under direct control by using a Solar box, on five types of reference polymers: high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET). A multi-analytical approach was adopted to investigate in detail the first steps of plastics degradation. Samples of plastic materials at different degradation times were analyzed by means of 1H NMR spectroscopy and thermal desorption gas chromatography mass spectrometry (TD-GC-MS) technique. Several minor molecular species released during degradation were consistently identified by both techniques thus providing a comprehensive view of the various degradation products of these five types of microplastics.
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20
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Li G, Fei Y, Kuang T, Liu T, Zhong M, Li Y, Jiang J, Turng LS, Chen F. The Injected Foaming Study of Polypropylene/Multiwall Carbon Nanotube Composite with In Situ Fibrillation Reinforcement. Polymers (Basel) 2022; 14:polym14245411. [PMID: 36559778 PMCID: PMC9781881 DOI: 10.3390/polym14245411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 11/30/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open
Abstract
This paper explored the injection foaming process of in situ fibrillation reinforced polypropylene composites. Using polypropylene (PP) as the continuous phase, polytetrafluoroethylene (PTFE) as the dispersed phase, multi-wall carbon nanotubes (MWCNTs) as the conductive filler, and PP grafted with maleic anhydride (PP-g-MA) as the compatibilizer, a MWCNTs/PP-g-MA masterbatch was prepared by using a solution blending method. Then, a lightweight, conductive PP/PTFE/MWCNTs composite foam was prepared by means of extruder granulation and supercritical nitrogen (ScN2) injection foaming. The composite foams were studied in terms of rheology, morphological, foaming behavior and mechanical properties. The results proved that the in situ fibrillation of PTFE can have a remarkable effect on melt strength and viscoelasticity, thus improving the foaming performance; we found that PP/3% PTFE showed excellent performance. Meanwhile, the addition of MWCNTs endows the material with conductive properties, and the conductivity reached was 2.73 × 10-5 S/m with the addition of 0.2 wt% MWCNTs. This study's findings are expected to be applied in the lightweight, antistatic and high-performance automotive industry.
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Affiliation(s)
- Gang Li
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yanpei Fei
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China
- Correspondence: (Y.F.); (J.J.); (F.C.)
| | - Tairong Kuang
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Tong Liu
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Mingqiang Zhong
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Yanbiao Li
- College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Jing Jiang
- National Center for International Research of Micro-Nano Molding Technology, School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou 450001, China
- Correspondence: (Y.F.); (J.J.); (F.C.)
| | - Lih-Sheng Turng
- Department of Mechanical Engineering, University of Wisconsin–Madison, Madison, WI 53706, USA
- Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Feng Chen
- College of Material Science and Engineering, Zhejiang University of Technology, Hangzhou 310014, China
- Correspondence: (Y.F.); (J.J.); (F.C.)
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Wu C. β-catenin inhibitors ICG-001 and pyrvinium sensitize bortezomib-resistant multiple myeloma cells to bortezomib. Oncol Lett 2022; 24:205. [PMID: 35720475 PMCID: PMC9178704 DOI: 10.3892/ol.2022.13326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 08/23/2021] [Indexed: 11/06/2022] Open
Abstract
Although bortezomib (BTZ) displays efficacy in treating multiple myeloma (MM), BTZ resistance in MM patients has been reported. Meanwhile, treating BTZ resistant MM cells with β-catenin inhibitors have demonstrated the ability to reserve BTZ resistance. Thus, the present study aimed to investigate the synergistic effect of the β-catenin inhibitors, ICG-001 and pyrvinium (PP), with BTZ in the treatment of BTZ-resistant MM cells. Different concentrations of ICG-001 (0–32 µM) or PP (0–32 nM) were used to treat the BTZ-resistant RPMI-8226 (RPMI-8226BR) and BTZ-resistant KMS-11 (KMS-11BR) cell lines, followed by a BTZ combination treatment. Subsequently, cell viability and apoptosis in these two cell lines were determined by CCK-8 assay and flow cytometry, respectively. The proteins involved in the Wnt/β-catenin signaling pathway were detected using western blotting. The Wnt/β-catenin signaling pathway was activated in the RPMI-8226BR and the KMS-11BR cells. In addition, the cell viability of RPMI-8226BR and KMS-11BR cells were decreased following β-catenin inhibitor (ICG-001 and PP) treatment alone. Furthermore, the β-catenin inhibitors, ICG-001 and PP, plus BTZ combination treatment revealed a notable decrease in cell viability and a marked increase in cell apoptosis rate, compared with that in cells treated with ICG-001, PP or BTZ alone in the RPMI-8226BR and KMS-11BR cell lines. In conclusion, the β-catenin inhibitors, ICG-001 and PP not only increased apoptosis, but also sensitized BTZ-resistant MM cells to BTZ, indicating their potential therapeutic application in MM.
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Affiliation(s)
- Cuicui Wu
- Department of Hematology, Yueyang Second People's Hospital, Yueyang, Hunan 414000, P.R. China
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22
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Qiu Z, He C. Polypropylene Hollow Fiber Membrane by Dissolution-Inducing Pore Methods. Membranes (Basel) 2022; 12:463. [PMID: 35629788 PMCID: PMC9144892 DOI: 10.3390/membranes12050463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/17/2022] [Accepted: 04/17/2022] [Indexed: 02/01/2023]
Abstract
Plasma leakage limits the development of polypropylene membranes as oxygenated membranes. Here, a new method named the dissolution-induced pore method was adapted to prepare polypropylene hollow fiber membranes: after polypropylene and polyvinyl chloride were melt-blended and extruded, the polyvinyl chloride was removed by N, N-dimethylacetamide to obtain a porous polypropylene membrane material. The variation of membranes has been explored in detail with respect to the influence of different parameters on the flux and mechanical properties of membranes and the feasibility of the polyvinyl chloride recovery. The resulting polypropylene hollow fiber membrane shows that plasma penetration was zero within 6 h of test, gas flux can reach 189,000 L/(m2·h·0.1 MPa), and its strength at break reaches 65 MPa and the elongation at break is 890%; polyvinyl chloride recovery achieves more than 99%. This research has developed a promising and low-cost extracorporeal membrane oxygenation material, which provides benefits for patients with less capacity for medical expenditure.
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Affiliation(s)
| | - Chunju He
- The State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, China;
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23
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Langley DB, Schofield P, Jackson J, Herzog H, Christ D. Crystal structures of human neuropeptide Y (NPY) and peptide YY (PYY). Neuropeptides 2022; 92:102231. [PMID: 35180645 DOI: 10.1016/j.npep.2022.102231] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/18/2022] [Accepted: 02/03/2022] [Indexed: 10/19/2022]
Abstract
Neuropeptide Y (NPY), peptide YY (PYY) and pancreatic polypeptide (PP) form the evolutionarily conserved pancreatic polypeptide family. While the fold is widely utilized in nature, crystal structures remain elusive, particularly for the human forms, with only the structure of a distant avian form of PP reported. Here we utilize a crystallization chaperone (antibody Fab fragment), specifically recognizing the amidated peptide termini, to solve the structures of human NPY and human PYY. Intriguingly, and despite limited sequence identity (~50%), the structure of human PYY closely resembles that of avian PP, highlighting the broad structural conservation of the fold throughout evolution. Specifically, the PYY structure is characterized by a C-terminal amidated α-helix, preceded by a backfolded poly-proline N-terminus, with the termini in close proximity to each other. In contrast, in the structure of human NPY the N-terminal component is disordered, while the helical component of the peptide is observed in a four-helix bundle type arrangement, consistent with a propensity for multimerization suggested by NMR studies.
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Affiliation(s)
- David B Langley
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, New South Wales 2010, Australia
| | - Peter Schofield
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, New South Wales 2010, Australia
| | - Jenny Jackson
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, New South Wales 2010, Australia
| | - Herbert Herzog
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, New South Wales 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW, Sydney, Australia
| | - Daniel Christ
- Garvan Institute of Medical Research, 384 Victoria St, Darlinghurst, New South Wales 2010, Australia; St Vincent's Clinical School, Faculty of Medicine, UNSW, Sydney, Australia.
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24
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Cai J, Jiang J, Yang Q, Cheng P, Chen K, Wang S. Effect of Drawing Parameters on the Properties of Polypropylene/Inorganic Particles Composites by Solid-State Die Drawing. Polymers (Basel) 2021; 13:polym13223913. [PMID: 34833211 PMCID: PMC8624137 DOI: 10.3390/polym13223913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/04/2021] [Accepted: 11/09/2021] [Indexed: 11/16/2022] Open
Abstract
Die drawing is an effective method for improving the properties of polymer. In this work, polypropylene (PP)/inorganic particle composites were fabricated by a solid-state die drawing process to investigate the effects of drawing parameters, such as inorganic particles types, drawing temperature, and drawing speed, on the thermal properties, microstructure, and mechanical behavior of the drawn composites. The mechanical properties of the material were significantly improved through this processing method. For the drawn PP/inorganic particle composites with 45 wt% CaCO3, when the drawing speed was 2.0 m/min and the drawing temperature was 110 °C, the density of the drawn composites reached the lowest at 1.00 g/cm3. At this time, the tensile strength, flexural strength, and impact strength of the drawn composites were 128.32 MPa, 77.12 MPa, and 170.42 KJ/m2, respectively. This work provides a new strategy for the preparation of lightweight and high-strength PP-based composites, which have broad application prospects in the field of engineering and structural materials.
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Affiliation(s)
- Jianchen Cai
- College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; (J.C.); (J.J.)
| | - Jinyun Jiang
- College of Mechanical Engineering, Quzhou University, Quzhou 324000, China; (J.C.); (J.J.)
| | - Qun Yang
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (Q.Y.); (P.C.)
| | - Peng Cheng
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (Q.Y.); (P.C.)
| | - Ke Chen
- College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029, China; (Q.Y.); (P.C.)
- Correspondence: ; Tel.: +86-10-6443-6016
| | - Suwei Wang
- National Special Superfine Powder Engineering Research Center of China, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China;
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Alsabri A, Tahir F, Al-Ghamdi SG. Life-Cycle Assessment of Polypropylene Production in the Gulf Cooperation Council (GCC) Region. Polymers (Basel) 2021; 13:polym13213793. [PMID: 34771349 PMCID: PMC8587715 DOI: 10.3390/polym13213793] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/26/2021] [Accepted: 10/29/2021] [Indexed: 11/16/2022] Open
Abstract
The environmental impacts of the polypropylene (PP) manufacturing process are not fully understood in the Gulf Cooperation Council (GCC) region. There is a growing interest in assessing the environmental impacts of this highly demanded product, especially for the petrochemical industry sector. This research examines the environmental impacts of the polypropylene manufacturing process using a life cycle assessment (LCA) approach. Gabi software is selected to carry out this research study and quantify the risks associated with manufacturing one ton of polypropylene, chosen as the functional unit for this LCA study. This work has the following merits: (i) an evaluation of environmental impacts specific to GCC region based on actual plant data; (ii) the results in this work can be used to evaluate LCA impacts of PP based products; and (iii) emphasizing the importance of waste management in reducing environmental impacts. This study shows that the polypropylene manufacturing process releases numerous pollutants into the environment, as the gross CO2 emissions for the manufacturing process of PP in the plant located in the GCC region were estimated to be 1.58 kg CO2 eq./kg-PP. The manufacturing process of propylene has extremely high impacts on global warming potential, fossil resource depletion (1.722 kg Oil eq./kg-PP), human toxicity (0.077 kg 1,4-DB eq./kg-PP), acidification (0.0049 kg SO2 eq./kg-PP), and petrochemical oxidant formation (0.0042 kg NMVOC/kg-PP). Additionally, based on the results of this present research, this study proposes possible improvements and alternative solutions such as applying advanced technologies, clean energy, and safe recycling processes in the GCC that are environmentally friendly.
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Zhang Y, Wang H, Xu J, Su X, Lu M, Wang Z, Zhang Y. Occurrence and Characteristics of Microplastics in a Wastewater Treatment Plant. Bull Environ Contam Toxicol 2021; 107:677-683. [PMID: 33616703 DOI: 10.1007/s00128-021-03142-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
Large quantities of microplastics (MPs) are discharged into the hydrosphere via the municipal wastewater treatment plant (WWTP) as an important route. Herein, we sampled the influent, effluent and sludge of WWTP in order to investigate the abundance, size, type, and shape of MPs. The detected MPs were primarily in the shape of fiber with the abundance up to 44 particles per liter. Polyethylene terephthalate, polypropylene, and polyethylene were found to be the three largest types of MPs. MPs in the influent was effectively eliminated with a removal efficiency of ~ 96%. However, a large quantity of MPs was still discharged in the effluent and the excess sludge, approximately 2.87 × 108 particles per day, indicating that some specific control facilities should be installed at WWTP to minimize the environmental impacts of MPs.
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Affiliation(s)
- Yunhai Zhang
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China
| | - Hao Wang
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China
| | - Jimin Xu
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China
| | - Xin Su
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China
| | - Meichi Lu
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China
| | - Zhiyuan Wang
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China
| | - Yongjun Zhang
- School of Environmental Science and Engineering, Nanjing Tech University, No. 30 Puzhu Road(S), Nanjing, 211816, China.
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Wu H, Huang J, Liu Y, Pan Y, Li Y, Miao Q, Qu L, Tian J. Feline Calicivirus Proteinase-Polymerase Protein Degrades mRNAs To Inhibit Host Gene Expression. J Virol 2021; 95:e0033621. [PMID: 33853967 DOI: 10.1128/JVI.00336-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To replicate efficiently and evade the antiviral immune response of the host, some viruses degrade host mRNA to induce host gene shutoff via encoding shutoff factors. In this study, we found that feline calicivirus (FCV) infection promotes the degradation of endogenous and exogenous mRNAs and induces host gene shutoff, which results in global inhibition of host protein synthesis. Screening assays revealed that proteinase-polymerase (PP) is a most effective factor in reducing mRNA expression. Moreover, PP from differently virulent strains of FCV could induce mRNA degradation. Further, we found that the key sites of the PP protein required for its proteinase activity are also essential for its shutoff activity but also required for viral replication. The mechanism analysis showed that PP mainly targets Pol II-transcribed RNA in a ribosome-, 5' cap-, and 3' poly(A) tail-independent manner. Moreover, purified glutathione S-transferase (GST)-PP fusion protein exhibits RNase activity in vitro in assays using green fluorescent protein (GFP) RNA transcribed in vitro as a substrate in the absence of other viral or cellular proteins. Finally, PP-induced shutoff requires host Xrn1 to complete further RNA degradation. This study provides a newly discovered strategy in which FCV PP protein induces host gene shutoff by promoting the degradation of host mRNAs. IMPORTANCE Virus infection-induced shutoff is the result of targeted or global manipulation of cellular gene expression and leads to efficient viral replication and immune evasion. FCV is a highly contagious pathogen that persistently infects cats. It is unknown how FCV blocks the host immune response and persistently exists in cats. In this study, we found that FCV infection promotes the degradation of host mRNAs and induces host gene shutoff via a common strategy. Further, PP protein for different FCV strains is a key factor that enhances mRNA degradation. An in vitro assay showed that the GST-PP fusion protein possesses RNase activity in the absence of other viral or cellular proteins. This study demonstrates that FCV induces host gene shutoff by promoting the degradation of host mRNAs, thereby introducing a potential mechanism by which FCV infection inhibits the immune response.
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28
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Manaia JP, Manaia A. Interface Modification, Water Absorption Behaviour and Mechanical Properties of Injection Moulded Short Hemp Fiber-Reinforced Thermoplastic Composites. Polymers (Basel) 2021; 13:1638. [PMID: 34070199 DOI: 10.3390/polym13101638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 11/16/2022] Open
Abstract
The effects of maleic anhydride, stearic acid and water absorption on the physical and flexural properties of injection moulded short hemp fiber-reinforced thermoplastic composites were investigated, in order to understand the suitability of these materials for outdoor applications. The water absorption, diffusion mechanisms and kinetics of composites were evaluated by immersing the specimens in distilled water at 23 °C. Flexural fracture surface morphologies were investigated in order to compare the results of flexural tests with qualitative morphological observations. The process of water absorption was found to follow the Fickian mode of diffusion. Flexural properties (Ef and σfm) were affected by the water absorption. The addition of maleic anhydride and stearic acid enhanced the resistance to water absorption of composites and resulted in a slight increase of flexural properties of composites based on a high-density polyethylene (HDPE) matrix. The reduction in flexural properties induced by the degradation of matrix-fiber interfacial bonding due to water absorbed was confirmed by scanning electron microscopy analysis.
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29
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Pîrvu C, Musteată AE, Ojoc GG, Deleanu L. Numerical and Experimental Results on Charpy Tests for Blends Polypropylene + Polyamide + Ethylene Propylene Diene Monomer ( PP + PA + EPDM). Materials (Basel) 2020; 13:E5837. [PMID: 33371408 PMCID: PMC7767435 DOI: 10.3390/ma13245837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/10/2020] [Accepted: 12/14/2020] [Indexed: 11/16/2022]
Abstract
This paper presents results from numerical and experimental investigation on Charpy tests in order to point out failure mechanisms and to evaluate new polymeric blends PP + PA6 + EPDM. Charpy tests were done for initial velocity of the impactor of 0.96 m/s and its mass of 3.219 kg and these data were also introduced in the finite element model. The proposed model takes into account the system of four balls, including support and the ring of fixing the three balls and it has a finer discretization of the impact area to highlight the mechanisms of failure and their development in time. The constitutive models for four materials (polypropylene with 1% Kritilen, two blends PP + PA6 + EPDM and a blend PA6 + EPDM) were derived from tensile tests. Running simulations for each constitutive model of material makes possible to differentiate the destruction mechanisms according to the material introduced in the simulation, including the initiation and the development of the crack(s), based on equivalent plastic strain at break (EPS) for each material. The validation of the model and the simulation results were done qualitatively, analyzing the shape of broken surfaces and comparing them to SEM images and quantitatively by comparing the impact duration, energy absorbed by the sample, the value of maximum force during impact. The duration of the destruction of the specimen is longer than the actual one, explainable by the fact that the material model does not take into account the influence of the material deformation speed in Charpy test, the model being designed with the help of tests done at 0.016 m/s (1000 mm/min) (maximum strain rate for the tensile tests). Experimental results are encouraging for recommending the blends 20% PP + 42% PA6 + 28% EPDM and 60% PA6 + 40% EPDM as materials for impact protection at low velocity (1 m/s). Simulation results are closer to the experimental ones for the more brittle tested materials (with less content of PA6 and EPDM) and more distanced for the more ductile materials (with higher content of PA6 and EPDM).
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Affiliation(s)
- Cătălin Pîrvu
- National Institute of Aerospace Research “Elie Carafoli” INCAS, 061126 Bucharest, Romania
| | - Andreea Elena Musteată
- Faculty of Engineering, “Dunărea de Jos” University of Galati, 800008 Galati, Romania; (A.E.M.); (G.G.O.)
| | - George Ghiocel Ojoc
- Faculty of Engineering, “Dunărea de Jos” University of Galati, 800008 Galati, Romania; (A.E.M.); (G.G.O.)
| | - Lorena Deleanu
- Faculty of Engineering, “Dunărea de Jos” University of Galati, 800008 Galati, Romania; (A.E.M.); (G.G.O.)
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30
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Noori A, Bartoli M, Frache A, Piatti E, Giorcelli M, Tagliaferro A. Development of Pressure-Responsive PolyPropylene and Biochar-Based Materials. Micromachines (Basel) 2020; 11:E339. [PMID: 32218104 DOI: 10.3390/mi11040339] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 03/23/2020] [Accepted: 03/23/2020] [Indexed: 11/16/2022]
Abstract
In this research paper, we reported the synthesis of biochar-based composites using biochar derived from exhausted tea leaves and polypropylene. The resulting materials were deeply characterized investigating mechanical (dynamic mechanical thermal analysis), thermal (thermogravimetrical analysis and differential scanning calorimetry), morphological (field emission scanning microscopy) and electrical properties vs. temperature. Furthermore, electrical conductivity was studied for a wide range of pressures showing an irreversible plastic deformation. An increment of one order of magnitude in the conductivity was observed in the case of 40 wt% biochar loading, reaching a value of 0.2 S/m. The material produced exhibited the properties of an irreversible pressure sensor.
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Fenton TM, Jørgensen PB, Niss K, Rubin SJS, Mörbe UM, Riis LB, Da Silva C, Plumb A, Vandamme J, Jakobsen HL, Brunak S, Habtezion A, Nielsen OH, Johansson-Lindbom B, Agace WW. Immune Profiling of Human Gut-Associated Lymphoid Tissue Identifies a Role for Isolated Lymphoid Follicles in Priming of Region-Specific Immunity. Immunity 2020; 52:557-570.e6. [PMID: 32160523 DOI: 10.1016/j.immuni.2020.02.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 01/09/2020] [Accepted: 02/13/2020] [Indexed: 12/19/2022]
Abstract
The intestine contains some of the most diverse and complex immune compartments in the body. Here we describe a method for isolating human gut-associated lymphoid tissues (GALTs) that allows unprecedented profiling of the adaptive immune system in submucosal and mucosal isolated lymphoid follicles (SM-ILFs and M-ILFs, respectively) as well as in GALT-free intestinal lamina propria (LP). SM-ILF and M-ILF showed distinct patterns of distribution along the length of the intestine, were linked to the systemic circulation through MAdCAM-1+ high endothelial venules and efferent lymphatics, and had immune profiles consistent with immune-inductive sites. IgA sequencing analysis indicated that human ILFs are sites where intestinal adaptive immune responses are initiated in an anatomically restricted manner. Our findings position ILFs as key inductive hubs for regional immunity in the human intestine, and the methods presented will allow future assessment of these compartments in health and disease.
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Affiliation(s)
- Thomas M Fenton
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark.
| | - Peter B Jørgensen
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Kristoffer Niss
- Translational Disease Systems Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Samuel J S Rubin
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Urs M Mörbe
- Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden
| | - Lene B Riis
- Department of Pathology, Herlev Hospital, University of Copenhagen, 2730 Herlev, Denmark
| | - Clément Da Silva
- Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden
| | - Adam Plumb
- Immunological Memory Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Julien Vandamme
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - Henrik L Jakobsen
- Department of Gastroenterology, Surgical Section, Herlev Hospital, University of Copenhagen, 2730 Herlev, Denmark
| | - Søren Brunak
- Translational Disease Systems Biology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Aida Habtezion
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ole H Nielsen
- Department of Gastroenterology, Medical Section, Herlev Hospital, University of Copenhagen, 2730 Herlev, Denmark
| | - Bengt Johansson-Lindbom
- Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden; Immunological Memory Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark
| | - William W Agace
- Mucosal Immunology Group, Department of Health Technology, Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby, Denmark; Immunology Section, Lund University, BMC D14, 221-84 Lund, Sweden.
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32
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Veedfald S, Vedtofte L, Skov-Jeppesen K, Deacon CF, Hartmann B, Vilsbøll T, Knop FK, Christensen MB, Holst JJ. Glucose-Dependent Insulinotropic Polypeptide Is a Pancreatic Polypeptide Secretagogue in Humans. J Clin Endocrinol Metab 2020; 105:5607542. [PMID: 31665480 DOI: 10.1210/clinem/dgz097] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 10/05/2019] [Indexed: 02/13/2023]
Abstract
BACKGROUND Glucose-dependent insulinotropic polypeptide (GIP) has been suggested to stimulate the secretion of pancreatic polypeptide (PP), an islet hormone thought to regulate gut motility, appetite, and glycemia. OBJECTIVE To determine whether human GIP1-42 (hGIP) stimulates PP secretion. METHOD As glycemia modulates the secretion of PP, we measured plasma PP concentrations from 2 studies in healthy men (n = 10) and in patients with type 2 diabetes (T2D) (n = 12), where hGIP1-42 had been administered intravenously during fasting glycemia, hyperglycemia (12 mmol/L), and insulin-induced hypoglycemia (targets: 2.5 mmol/L [healthy]; 3.5 mmol/L [T2D]). Porcine GIP1-42 (pGIP) was also infused intra-arterially in isolated porcine pancreata (n = 4). RESULTS Mean fasting plasma glucose concentrations were approximately 5 mmol/L (healthy) and approximately 8 mmol/L (T2D). At fasting glycemia, PP concentrations were higher during intravenous hGIP1-42 infusion compared with saline in healthy men (mean [standard error of the mean, SEM], net incremental areas under the curves (iAUCs)[0-30min], 403 [116] vs -6 [57] pmol/L × min; P = 0.004) and in patients with T2D (905 [177] vs -96 [86] pmol/L × min; P = 0.009). During hyperglycemic clamping, mean [SEM] PP concentrations were significantly higher during hGIP1-42 infusion compared with saline in patients with T2D (771 [160] vs -183 [117] pmol/L × min; P = 0.001), but not in healthy individuals (-8 [86] vs -57 [53] pmol/L × min; P = 0.69). When plasma glucose levels were declining in response to exogenous insulin, mean [SEM] PP concentrations were higher during hGIP1-42 infusion compared with saline in healthy individuals (294 [88] vs -82 [53] pmol/L × min; P = 0.0025), but not significantly higher in patients with T2D (586 [314] vs -120 [53]; P = 0.070). At target hypoglycemia, PP levels surged in both groups during both hGIP1-42 and saline infusions. In isolated pancreata, pGIP1-42 increased mean [SEM] PP output in the pancreatic venous effluent (baseline vs infusion, 24[5] vs 79 [16] pmol/min x min; P = 0.044). CONCLUSION GIP1-42 increases plasma PP secretion in healthy individuals, patients with T2D, and isolated porcine pancreata. Hyperglycemia blunts the stimulatory effect of hGIP1-42 in healthy individuals, but not in patients with T2D.
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Affiliation(s)
- Simon Veedfald
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Louise Vedtofte
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Kirsa Skov-Jeppesen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Carolyn F Deacon
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Bolette Hartmann
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
| | - Tina Vilsbøll
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Filip K Knop
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Gentofte, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mikkel B Christensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Clinical Pharmacology, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark
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Schiavo S, Oliviero M, Chiavarini S, Manzo S. Adverse effects of oxo-degradable plastic leachates in freshwater environment. Environ Sci Pollut Res Int 2020; 27:8586-8595. [PMID: 31904098 DOI: 10.1007/s11356-019-07466-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 12/19/2019] [Indexed: 06/10/2023]
Abstract
The production of biodegradable plastics is considered to be a way to reduce plastic waste issue. Among others, oxo-degradant additives enable a faster degradation of plastics in the environment. However, the introduction of these new materials could provoke the release of substances potentially toxic in the environment. This work determined and compared the toxicity of leachates from various additivated polymers (polyethylene, PE; polypropylene, PP; polystyrene, PS) upon different test organisms: plants (Sorghum saccharatum, Lepidium sativum, Sinapis alba, and Vicia faba), crustacean (Daphnia magna), and luminescent bacteria (Vibrio fischeri). Daphnia magna survival was mainly affected by PS and PP leachates (72% and 61% effect, respectively) while PS notably reduced the reproduction rate. On plants, only PP exerted a negative effect (S. saccharatum IG% 32.4), while V. fischeri always showed values around 50%. The data integration, through the Toxicity Test Battery Integrated Index (TBI) approach, allowed to rank the leachates toxicity as PE > PS > PP. This result could be mainly ascribable to the highest metals content in PE since no difference with organic compounds analysis was evidenced. In conclusion, since the polymers exerted dissimilar toxicity, the additive could not be considered the sole responsible of the measured toxicity, but its role in the enhancement of the virgin polymers leachates effects can be solidly hypothesized.
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Affiliation(s)
- Simona Schiavo
- ENEA CR Portici, SSPT-PROTER Division, P. le E. Fermi, 1, 80055, Portici, Naples, Italy
- University of Naples Parthenope, Naples, Italy
| | - Maria Oliviero
- ENEA CR Portici, SSPT-PROTER Division, P. le E. Fermi, 1, 80055, Portici, Naples, Italy
| | - Salvatore Chiavarini
- ENEA CR Casaccia, SSPT-PROTER Division, via Anguillarese 301, 00123, Rome, Italy
| | - Sonia Manzo
- ENEA CR Portici, SSPT-PROTER Division, P. le E. Fermi, 1, 80055, Portici, Naples, Italy.
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He X, Rytöluoto I, Anyszka R, Mahtabani A, Saarimäki E, Lahti K, Paajanen M, Dierkes W, Blume A. Surface Modification of Fumed Silica by Plasma Polymerization of Acetylene for PP/POE Blends Dielectric Nanocomposites. Polymers (Basel) 2019; 11:E1957. [PMID: 31795227 DOI: 10.3390/polym11121957] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/08/2019] [Accepted: 11/26/2019] [Indexed: 11/17/2022] Open
Abstract
Novel nanocomposites for dielectric applications-based polypropylene/poly(ethylene-co-octene) (PP/POE) blends filled with nano silica are developed in the framework of the European ‘GRIDABLE’ project. A tailor-made low-pressure-plasma reactor was applied in this study for an organic surface modification of silica. Acetylene gas was used as the monomer for plasma polymerization in order to deposit a hydrocarbon layer onto the silica surface. The aim of this modification is to increase the compatibility between silica and the PP/POE blends matrix in order to improve the dispersion of the filler in the polymer matrix and to suppress the space charge accumulation by altering the charge trapping properties of these silica/PP/POE blends composites. The conditions for the deposition of the acetylene plasma-polymer onto the silica surface were optimized by analyzing the modification in terms of weight loss by thermogravimetry (TGA). X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray fluorescence spectroscopy (EDX) measurements confirmed the presence of hydrocarbon compounds on the silica surface after plasma modification. The acetylene plasma modified silica with the highest deposition level was selected to be incorporated into the PP/POE blends matrix. X-ray diffraction (XRD) showed that there is no new crystal phase formation in the PP/POE blends nanocomposites after addition of the acetylene plasma modified silica. Differential scanning calorimetry results (DSC) show two melting peaks and two crystallization peaks of the PP/POE blends nanocomposites corresponding to the PP and POE domains. The improved dispersion of the silica after acetylene plasma modification in the PP/POE blends matrix was shown by means of SEM–EDX mapping. Thermally stimulated depolarization current (TSDC) measurements confirm that addition of the acetylene plasma modified silica affects the charge trapping density and decreases the amount of injected charges into PP/POE blends nanocomposites. This work shows that acetylene plasma modification of the silica surface is a promising route to tune charge trapping properties of PP/POE blend-based nanocomposites.
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Watanabe R, Hagihara H, Sato H, Mizukado J, Shinzawa H. Rheo-Optical Near-Infrared (NIR) Characterization of Hydroxyl-Functionalized Polypropylene ( PPOH)-Mesoporous Silica Nanocomposites Using Two-Trace Two-Dimensional (2T2D) Correlation Analysis. Appl Spectrosc 2019; 73:1317-1326. [PMID: 31219323 DOI: 10.1177/0003702819861564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A rheo-optical characterization technique based on the combination of near-infrared (NIR) spectroscopy and mechanical analysis was applied to the nanocomposite consisting of hydroxyl-functionalized polypropylene (PPOH) and mesoporous silica (MPS) to probe the deformation behavior. Substantial levels of spectral changes of NIR spectral features were captured when the polymer samples underwent tensile deformation. Sets of spectra were subjected to projection treatment to remove the effect of baseline fluctuations and thickness change inevitably caused by the tensile deformation of the sample. Then, two-trace two-dimensional (2T2D) correlation spectroscopy was applied to the pretreated spectra to elucidate spectroscopic signature associated with the difference between the initial and deformed samples. An asynchronous correlation peak appears between the bands at 1720 and 1700 nm respectively reflecting the contributions of predominantly amorphous and crystalline component of the PPOH, indicating the predominant variation of amorphous structure followed by that of crystalline structure. In addition, the predominant spectral change related to the amorphous band becomes even more acute by including the MPS with large pores. It is hence likely that the larger pore size of the MPS confines the more amorphous structure, which, in turn, causes simultaneous reorientation of the polymer chains in the amorphous region during the elastic deformation. Consequently, the incorporation of the MPS selectively restricts the deformation of the amorphous structure which eventually provides the obvious increase in the mechanical property of the PPOH polymer.
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Affiliation(s)
- Ryota Watanabe
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Hideaki Hagihara
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Hiroaki Sato
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Junji Mizukado
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Hideyuki Shinzawa
- Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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Veigure R, Lossmann K, Hecht M, Parman E, Born R, Leito I, Herodes K, Kipper K. Retention of acidic and basic analytes in reversed phase column using fluorinated and novel eluent additives for liquid chromatography-tandem mass spectrometry. J Chromatogr A 2020; 1613:460667. [PMID: 31708217 DOI: 10.1016/j.chroma.2019.460667] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 10/24/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022]
Abstract
This research focuses on retention mechanisms in a LC column with C18 stationary phase when novel eluent additives (HFIP, HFTB and TFE as well as NFTB and perfluoropinacol) are used. The retention factors between novel eluent additives and conventional ones like ammonium acetate and ammonium bicarbonate at different eluent pH values were compared. A simple set of drug-like molecules, widely spread over different logP values, containing protonated and deprotonated acids and bases was selected for this investigation. HFIP, HFTB, NFTB and PP demonstrated strong influence on basic polar analytes in basic medium. These additives drastically increased retention. A decrease in retention was observed for acidic analytes when novel eluent additives were used. Additionally, for the first time, the absolute pH (pHabs) scale was used for expressing the mobile phase pH.
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Mao Y, Li Q, Wu C. Surface Modification of PET Fiber with Hybrid Coating and Its Effect on the Properties of PP Composites. Polymers (Basel) 2019; 11:E1726. [PMID: 31640264 DOI: 10.3390/polym11101726] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/18/2019] [Accepted: 10/18/2019] [Indexed: 11/18/2022] Open
Abstract
Surface modification fundamentally influences the morphology of polyethylene terephthalate (PET) fibers produced from abandoned polyester textiles and improve the compatibility between the fiber and the matrix. In this study, PET fiber was modified through solution dip-coating using a novel synthesized tetraethyl orthosilicate (TEOS)/KH550/ polypropylene (PP)-g-MAH (MPP) hybrid (TMPP). The PET fiber with TMPP modifier was exposed to the air. SiO2 particles would be hydrolyzed from TEOS and become the crystalline cores of MPP. Then, the membrane formed by MPP, SiO2 and KH550 covered the surface of the PET fiber. TMPP powder was investigated and characterized by fourier transform infrared spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). TMPP-modified PET fiber was researched by X-ray diffraction and SEM. Furthermore, tensile strength of single fiber was also tested. PET fiber/PP composites were studied through dynamic mechanical analysis and SEM. Flexural properties of composites were also measured. The interfacial properties of PET fiber and PP matrix were indirectly represented by contact angle analysis. Results showed that the addition of TEOS is helpful in homogenizing the distribution of PP-g-MAH. Furthermore, TMPP generates an organic-inorganic ‘armor’ structure on PET fiber, which can make up for the damage areas on the surface of PET fiber and strengthen each single-fiber by 14.4%. Besides, bending strength and modulus of TMPP-modified PET fiber-reinforced PP composite respectively, increase by 10 and 800 MPa. The compatibility between PET fiber and PP was also confirmed to be increased by TMPP. Predictably, this work supplied a new way for PET fiber modification and exploited its potential applications in composites.
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Eggersdorfer M, Wyss A. Carotenoids in human nutrition and health. Arch Biochem Biophys 2018; 652:18-26. [PMID: 29885291 DOI: 10.1016/j.abb.2018.06.001] [Citation(s) in RCA: 416] [Impact Index Per Article: 69.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/17/2018] [Accepted: 06/01/2018] [Indexed: 01/05/2023]
Abstract
Carotenoids are naturally occurring pigments found in most fruits and vegetables, plants, algae, and photosynthetic bacteria. Humans cannot synthesize carotenoids and must ingest them in food or via supplementation. Carotenoids have a range of functions in human health. They primarily exert antioxidant effects, but individual carotenoids may also act through other mechanisms; for example, β-carotene has a pro-vitamin A function, while lutein/zeaxanthin constitute macular pigment in the eye. The benefit of lutein in reducing progression of age-related macular eye disease and cataracts is strengthening; an intake recommendation would help to generate awareness in the general population to have an adequate intake of lutein rich foods. There is evidence that carotenoids, in addition to beneficial effects on eye health, also produce improvements in cognitive function and cardiovascular health, and may help to prevent some types of cancer. Despite the evidence for the health benefits of carotenoids, large population-based supplementation studies have produced mixed results for some of the carotenoids. To establish and confirm the health benefits of the different carotenoids more research, including clinical studies, is needed.
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Affiliation(s)
- Manfred Eggersdorfer
- Department of Internal Medicine, University Medical Center Groningen, The Netherlands; Nutrition Science & Advocacy, DSM Nutritional Products, Wurmisweg 576, Kaiseraugst, Switzerland
| | - Adrian Wyss
- DSM Nutritional Products, R&D Human Nutrition, Wurmisweg 576, Kaiseraugst, Switzerland.
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Nguyen-Tran HD, Hoang VT, Do VT, Chun DM, Yum YJ. Effect of Multiwalled Carbon Nanotubes on the Mechanical Properties of Carbon Fiber-Reinforced Polyamide-6/Polypropylene Composites for Lightweight Automotive Parts. Materials (Basel) 2018; 11:E429. [PMID: 29543754 DOI: 10.3390/ma11030429] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/03/2018] [Accepted: 03/14/2018] [Indexed: 11/16/2022]
Abstract
The development of lightweight automotive parts is an important issue for improving the efficiency of vehicles. Polymer composites have been widely applied to reduce weight and improve mechanical properties by mixing polymers with carbon fibers, glass fibers, and carbon nanotubes. Polypropylene (PP) has been added to carbon fiber-reinforced nylon-6 (CF/PA6) composite to achieve further weight reduction and water resistance. However, the mechanical properties were reduced by the addition of PP. In this research, multiwalled carbon nanotubes (CNTs) were added to compensate for the reduced mechanical properties experienced when adding PP. Tensile testing and bending tests were carried out to evaluate the mechanical properties. A small amount of CNTs improved the mechanical properties of carbon fiber-reinforced PA6/PP composites. For example, the density of CF/PA6 was reduced from 1.214 to 1.131 g/cm³ (6.8%) by adding 30 wt % PP, and the tensile strength of 30 wt % PP composite was improved from 168 to 173 MPa (3.0%) by adding 0.5 wt % CNTs with small increase of density (1.135 g/cm³). The developed composite will be widely used for lightweight automotive parts with improved mechanical properties.
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Wang X, Sterr M, Burtscher I, Chen S, Hieronimus A, Machicao F, Staiger H, Häring HU, Lederer G, Meitinger T, Cernilogar FM, Schotta G, Irmler M, Beckers J, Hrabě de Angelis M, Ray M, Wright CVE, Bakhti M, Lickert H. Genome-wide analysis of PDX1 target genes in human pancreatic progenitors. Mol Metab 2018; 9:57-68. [PMID: 29396371 PMCID: PMC5870105 DOI: 10.1016/j.molmet.2018.01.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/05/2018] [Accepted: 01/16/2018] [Indexed: 12/14/2022] Open
Abstract
Objective Homozygous loss-of-function mutations in the gene coding for the homeobox transcription factor (TF) PDX1 leads to pancreatic agenesis, whereas heterozygous mutations can cause Maturity-Onset Diabetes of the Young 4 (MODY4). Although the function of Pdx1 is well studied in pre-clinical models during insulin-producing β-cell development and homeostasis, it remains elusive how this TF controls human pancreas development by regulating a downstream transcriptional program. Also, comparative studies of PDX1 binding patterns in pancreatic progenitors and adult β-cells have not been conducted so far. Furthermore, many studies reported the association between single nucleotide polymorphisms (SNPs) and T2DM, and it has been shown that islet enhancers are enriched in T2DM-associated SNPs. Whether regions, harboring T2DM-associated SNPs are PDX1 bound and active at the pancreatic progenitor stage has not been reported so far. Methods In this study, we have generated a novel induced pluripotent stem cell (iPSC) line that efficiently differentiates into human pancreatic progenitors (PPs). Furthermore, PDX1 and H3K27ac chromatin immunoprecipitation sequencing (ChIP-seq) was used to identify PDX1 transcriptional targets and active enhancer and promoter regions. To address potential differences in the function of PDX1 during development and adulthood, we compared PDX1 binding profiles from PPs and adult islets. Moreover, combining ChIP-seq and GWAS meta-analysis data we identified T2DM-associated SNPs in PDX1 binding sites and active chromatin regions. Results ChIP-seq for PDX1 revealed a total of 8088 PDX1-bound regions that map to 5664 genes in iPSC-derived PPs. The PDX1 target regions include important pancreatic TFs, such as PDX1 itself, RFX6, HNF1B, and MEIS1, which were activated during the differentiation process as revealed by the active chromatin mark H3K27ac and mRNA expression profiling, suggesting that auto-regulatory feedback regulation maintains PDX1 expression and initiates a pancreatic TF program. Remarkably, we identified several PDX1 target genes that have not been reported in the literature in human so far, including RFX3, required for ciliogenesis and endocrine differentiation in mouse, and the ligand of the Notch receptor DLL1, which is important for endocrine induction and tip-trunk patterning. The comparison of PDX1 profiles from PPs and adult human islets identified sets of stage-specific target genes, associated with early pancreas development and adult β-cell function, respectively. Furthermore, we found an enrichment of T2DM-associated SNPs in active chromatin regions from iPSC-derived PPs. Two of these SNPs fall into PDX1 occupied sites that are located in the intronic regions of TCF7L2 and HNF1B. Both of these genes are key transcriptional regulators of endocrine induction and mutations in cis-regulatory regions predispose to diabetes. Conclusions Our data provide stage-specific target genes of PDX1 during in vitro differentiation of stem cells into pancreatic progenitors that could be useful to identify pathways and molecular targets that predispose for diabetes. In addition, we show that T2DM-associated SNPs are enriched in active chromatin regions at the pancreatic progenitor stage, suggesting that the susceptibility to T2DM might originate from imperfect execution of a β-cell developmental program. PDX1 ChIP-seq analysis revealed 5664 target genes in human pancreatic progenitors, including unreported target genes. Comparison of PDX1 profiles from PPs and adult human islets identified stage-specific PDX1 target gene sets. T2DM-associated SNPs are enriched in active chromatin regions from iPSC-derived PPs. Three SNPs fall into PDX1 occupied sites, located in intronic regions of the developmental regulatory TFs TCF7L2 and HNF1B.
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Affiliation(s)
- Xianming Wang
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of ß-Cell Biology, Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Michael Sterr
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of ß-Cell Biology, Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Ingo Burtscher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Shen Chen
- iPS and Cancer Research Unit, Department of Histology and Embryology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China
| | - Anja Hieronimus
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, University of Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Fausto Machicao
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Harald Staiger
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Institute of Pharmaceutical Sciences, Department of Pharmacy and Biochemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Disease, Nephrology and Clinical Chemistry, University of Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Gabriele Lederer
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Filippo M Cernilogar
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Gunnar Schotta
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Johannes Beckers
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Martin Hrabě de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Michael Ray
- Vanderbilt University Program in Developmental Biology, Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Christopher V E Wright
- Vanderbilt University Program in Developmental Biology, Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Parkring 11, 85748, Garching, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of ß-Cell Biology, Technische Universität München, Ismaningerstraße 22, 81675 München, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
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Abstract
PURPOSE OF REVIEW In recent years, the role of the gastrointestinal (GI) tract in energy homeostasis through modulation of the digestion and absorption of carbohydrates and the production of incretin hormones is well recognized. RECENT FINDINGS Bariatric surgery for obesity has been a very effective method in substantially improving weight, and numerous studies have focused on intestinal adaptation after bariatric procedures. A number of structural and functional changes in the GI tract have been reported postsurgery, which could be responsible for the altered hormonal responses. Furthermore, the change in food absorption rate and the intestinal regions exposed to carbohydrates may affect blood glucose response. This review hopes to give new insights into the direct role of gut hormones, by summarising the metabolic effects of bariatric surgery.
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Affiliation(s)
- Georgios K Dimitriadis
- Division of Translational and Experimental Medicine, Clinical Sciences Research Laboratories, University of Warwick Medical School, Coventry, CV2 2DX, UK.
- Academic Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, London, W12 0NN, UK.
- Division of Translational and Experimental Medicine-Metabolic and Vascular Health, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK.
| | - Manpal S Randeva
- Division of Translational and Experimental Medicine, Clinical Sciences Research Laboratories, University of Warwick Medical School, Coventry, CV2 2DX, UK
| | - Alexander D Miras
- Academic Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, London, W12 0NN, UK
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He C, Zhang J, Gao S, Meng F, Bu G, Li J, Wang Y. Molecular characterization of three NPY receptors (Y2, Y5 and Y7) in chickens: Gene structure, tissue expression, promoter identification, and functional analysis. Gen Comp Endocrinol 2016; 236:24-34. [PMID: 27142335 DOI: 10.1016/j.ygcen.2016.04.019] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 04/18/2016] [Accepted: 04/22/2016] [Indexed: 02/02/2023]
Abstract
Six neuropeptide Y (NPY) receptors are suggested to mediate the biological actions of NPY, peptide YY (PYY), and pancreatic polypeptide (PP), such as food intake in birds, however, information regarding the structure and signaling of avian NPY receptors are rather limited. In this study, we investigated the gene structure, tissue expression and signaling property of three NPY receptors (cY2, cY5 and cY7) in chickens. The results showed that 1) cY2, cY5 and cY7 contain novel non-coding exons upstream of their start codon and alternative mRNA splicing in their 5'-UTR results in the formation of multiple transcript variants; 2) cY2, cY5 and cY7 transcripts were detected to be widely expressed in adult chicken tissues including various brain regions by RT-PCR, and their expression is controlled by a promoter(s) near exon 1, which display promoter activity in DF-1 cells as demonstrated by Dual-luciferase reporter assay; 3) cY2, cY5 and cY7 expressed in HEK293 cells were preferentially (or potently) activated by cNPY1-36 and cPYY1-37, but not by cPP1-36, and their activation led to the inhibition of cAMP/PKA signaling pathway and activation of MAPK/ERK signaling pathway, monitored by the cell-based luciferase reporter systems or western blots, indicating that the three NPY receptors are functional and capable of transmitting signals effectively. On the whole, our data establishes a molecular basis to elucidate the actions of three functional NPY receptors (cY2, cY5 and cY7) and their ligands in birds, which helps to uncover the conserved roles of these ligand-receptor pairs in vertebrates.
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Affiliation(s)
- Chen He
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Jiannan Zhang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Shunyu Gao
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China; College of Chemistry and Life Sciences, Chuxiong Normal University, Chuxiong 675000, PR China
| | - Fengyan Meng
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Guixian Bu
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Juan Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China
| | - Yajun Wang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, PR China.
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Wu H, Zu S, Sun X, Liu Y, Tian J, Qu L. N-Terminal Domain of Feline Calicivirus (FCV) Proteinase-Polymerase Contributes to the Inhibition of Host Cell Transcription. Viruses 2016; 8:E199. [PMID: 27447663 DOI: 10.3390/v8070199] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 07/13/2016] [Accepted: 07/15/2016] [Indexed: 11/17/2022] Open
Abstract
Feline Calicivirus (FCV) infection results in the inhibition of host protein synthesis, known as “shut-off”. However, the precise mechanism of shut-off remains unknown. Here, we found that the FCV strain 2280 proteinase-polymerase (PP) protein can suppress luciferase reporter gene expression driven by endogenous and exogenous promoters. Furthermore, we found that the N-terminal 263 aa of PP (PPN-263) determined its shut-off activity using the expression of truncated proteins. However, the same domain of the FCV strain F9 PP protein failed to inhibit gene expression. A comparison between strains 2280 and F9 indicated that Val27, Ala96 and Ala98 were key sites for the inhibition of host gene expression by strain 2280 PPN-263, and PPN-263 exhibited the ability to shut off host gene expression as long as it contained any two of the three amino acids. Because the N-terminus of the PP protein is required for its proteinase and shut-off activities, we investigated the ability of norovirus 3C-like proteins (3CLP) from the GII.4-1987 and -2012 isolates to interfere with host gene expression. The results showed that 3CLP from both isolates was able to shut off host gene expression, but 3CLP from GII.4-2012 had a stronger inhibitory activity than that from GII.4-1987. Finally, we found that 2280 PP and 3CLP significantly repressed reporter gene transcription but did not affect mRNA translation. Our results provide new insight into the mechanism of the FCV-mediated inhibition of host gene expression.
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Brereton MF, Vergari E, Zhang Q, Clark A. Alpha-, Delta- and PP-cells: Are They the Architectural Cornerstones of Islet Structure and Co-ordination? J Histochem Cytochem 2015. [PMID: 26216135 DOI: 10.1369/0022155415583535] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Islet non-β-cells, the α- δ- and pancreatic polypeptide cells (PP-cells), are important components of islet architecture and intercellular communication. In α-cells, glucagon is found in electron-dense granules; granule exocytosis is calcium-dependent via P/Q-type Ca(2+)-channels, which may be clustered at designated cell membrane sites. Somatostatin-containing δ-cells are neuron-like, creating a network for intra-islet communication. Somatostatin 1-28 and 1-14 have a short bioactive half-life, suggesting inhibitory action via paracrine signaling. PP-cells are the most infrequent islet cell type. The embryologically separate ventral pancreas anlage contains PP-rich islets that are morphologically diffuse and α-cell deficient. Tissue samples taken from the head region are unlikely to be representative of the whole pancreas. PP has anorexic effects on gastro-intestinal function and alters insulin and glucagon secretion. Islet architecture is disrupted in rodent diabetic models, diabetic primates and human Type 1 and Type 2 diabetes, with an increased α-cell population and relocation of non-β-cells to central areas of the islet. In diabetes, the transdifferentiation of non-β-cells, with changes in hormone content, suggests plasticity of islet cells but cellular function may be compromised. Understanding how diabetes-related disordered islet structure influences intra-islet cellular communication could clarify how non-β-cells contribute to the control of islet function.
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Affiliation(s)
- Melissa F Brereton
- Department of Physiology, Anatomy and Genetics, University of Oxford, United Kingdom. (MFB)
| | - Elisa Vergari
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom. (EV, QZ, AC)
| | - Quan Zhang
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom. (EV, QZ, AC)
| | - Anne Clark
- Oxford Centre for Diabetes, Endocrinology and Metabolism, University of Oxford, United Kingdom. (EV, QZ, AC)
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Montemurro F, Prat A, Rossi V, Valabrega G, Sperinde J, Peraldo-Neia C, Donadio M, Galván P, Sapino A, Aglietta M, Baselga J, Scaltriti M. Potential biomarkers of long-term benefit from single-agent trastuzumab or lapatinib in HER2-positive metastatic breast cancer. Mol Oncol 2014; 8:20-6. [PMID: 24075779 PMCID: PMC5528507 DOI: 10.1016/j.molonc.2013.08.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 01/06/2023] Open
Abstract
In 2009 a prospective, randomized Phase II trial (NCT00842998) was initiated to evaluate the activity of HER2-targeting agents without chemotherapy (CT) in HER2-positive metastatic breast cancer (MBC) patients. The primary tumors of the patients enrolled in this study offered a unique opportunity to identify biomarkers that could predict durable clinical benefit from CT-free anti-HER2 therapy. Patients with HER2-positive MBC were randomized to trastuzumab or lapatinib as first-line therapy. CT was added to anti-HER2 therapy in patients failing to achieve tumor regression at the 8-week evaluation and in those progressing at any time. Expression analysis of 105 selected genes was performed from formalin-fixed paraffin-embedded primary tumor samples. The research-based PAM50 intrinsic subtypes were also identified. Additionally, quantitative HER2 (H2T) and p95HER2 (p95) protein expression were evaluated by HERmark® and VeraTag® assay, respectively. Predictors of persistence on protocol (PP) were studied by Cox univariate and multivariate analysis. Nineteen patients were enrolled. Median overall survival was 43 months and median PP was 3.8 months (0.8-38.8+), with 4 patients (21.1%) persisting on single agent trastuzumab or lapatinib for longer than 12 mo (14.9-38.8 + mo). Seventeen patients were evaluable for PP. Gene expression analysis revealed that high expression of the 17q12-21 amplicon genes HER2 and GRB7, and the PAM50 HER2-enriched intrinsic profile, were significantly associated with longer PP. Conversely, high expression of luminal-related genes such as PGR, MDM2 or PIK3CA, or the PAM50 luminal intrinsic profile correlated with reduced PP. Moreover, increasing H2T/p95 ratio was found to be significantly associated with longer PP (HR 0.56 per 2-fold increase in H2T/p95, P = 0.0015). Our data suggest that patients belonging to the "HER2-enriched" subtype and/or having high H2T/p95 protein expression ratio are exquisitely sensitive to anti-HER2 agents. MBC patients with these tumors could be candidates for studies aimed at establishing chemotherapy-free regimens.
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Affiliation(s)
- Filippo Montemurro
- Unit of Investigative Clinical Oncology (INCO), Fondazione del Piemonte per l'Oncologia, Institute of Candiolo (IRCCs), Str. Provinciale 142, 10060 Candiolo, Italy; Division of Medical Oncology, Fondazione del Piemonte per l'Oncologia, Institute of Candiolo (IRCCs), Str. Provinciale 142, 10060 Candiolo, Italy
| | - Aleix Prat
- Translational Genomics Group, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Valentina Rossi
- Unit of Investigative Clinical Oncology (INCO), Fondazione del Piemonte per l'Oncologia, Institute of Candiolo (IRCCs), Str. Provinciale 142, 10060 Candiolo, Italy
| | - Giorgio Valabrega
- Division of Medical Oncology, Fondazione del Piemonte per l'Oncologia, Institute of Candiolo (IRCCs), Str. Provinciale 142, 10060 Candiolo, Italy
| | - Jeff Sperinde
- Clinical Research, Monogram Biosciences, Inc., 345 Oyster Point Blvd., South San Francisco, CA, USA
| | - Caterina Peraldo-Neia
- Laboratory of Cell Therapy, Fondazione del Piemonte per l'Oncologia, Institute of Candiolo (IRCCs), Candiolo, Italy
| | - Michela Donadio
- A.O. Città della Salute e della Scienza di Torino - sede Molinette, C.so Bramante 88/90, 10126 Torino, Italy
| | - Patricia Galván
- Translational Genomics Group, Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - Anna Sapino
- Department of Biological Sciences and Human Oncology, Universita di Torino, Str. Provinciale 142, 10060 Candiolo, Italy
| | - Massimo Aglietta
- Division of Medical Oncology, Fondazione del Piemonte per l'Oncologia, Institute of Candiolo (IRCCs), Str. Provinciale 142, 10060 Candiolo, Italy
| | - José Baselga
- Human Oncology & Pathogenesis Program (HOPP), Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 20, New York, NY 10065, USA
| | - Maurizio Scaltriti
- Human Oncology & Pathogenesis Program (HOPP), Memorial Sloan Kettering Cancer Center, 1275 York Avenue, Box 20, New York, NY 10065, USA.
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Wang H, Wang CQ, Fu JG, Gu GH. Flotability and flotation separation of polymer materials modulated by wetting agents. Waste Manag 2014; 34:309-315. [PMID: 24355830 DOI: 10.1016/j.wasman.2013.11.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 11/17/2013] [Accepted: 11/19/2013] [Indexed: 06/03/2023]
Abstract
The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS)>tannic acid (TA)>methylcellulose (MC)>triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%.
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Affiliation(s)
- Hui Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China.
| | - Chong-qing Wang
- School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China
| | - Jian-gang Fu
- School of Chemistry and Chemical Engineering, Key Laboratory of Resources Chemistry of Nonferrous Metals, Ministry of Education, Central South University, Changsha, 410083 Hunan, China
| | - Guo-hua Gu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083 Hunan, China
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Graham DY, Lee YC, Wu MS. Rational Helicobacter pylori therapy: evidence-based medicine rather than medicine-based evidence. Clin Gastroenterol Hepatol 2014; 12:177-86.e3; Discussion e12-3. [PMID: 23751282 PMCID: PMC3830667 DOI: 10.1016/j.cgh.2013.05.028] [Citation(s) in RCA: 249] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/07/2013] [Accepted: 05/15/2013] [Indexed: 02/07/2023]
Abstract
Data are available such that choice of Helicobacter pylori therapy for an individual patient can be reliably predicted. Here, treatment success is defined as a cure rate of 90% or greater. Treatment outcome in a population or a patient can be calculated based on the effectiveness of a regimen for infections with susceptible and with resistant strains coupled with the knowledge of the prevalence of resistance (ie, based on formal measurement, clinical experience, or both). We provide the formula for predicting outcome and we illustrate the calculations. Because clarithromycin-containing triple therapy and 10-day sequential therapy are now only effective in special populations, they are considered obsolete; neither should continue to be used as empiric therapies (ie, 7- and 14-day triple therapies fail when clarithromycin resistance exceeds 5% and 15%, respectively, and 10-day sequential therapy fails when metronidazole resistance exceeds 20%). Therapy should be individualized based on prior history and whether the patient is in a high-risk group for resistance. The preferred choices for Western countries are 14-day concomitant therapy, 14-day bismuth quadruple therapy, and 14-day hybrid sequential-concomitant therapy. We also provide details regarding the successful use of fluoroquinolone-, rifabutin-, and furazolidone-containing therapies. Finally, we provide recommendations for the efficient development (ie, identification and optimization) of new regimens, as well as how to prevent or minimize failures. The trial-and-error approach for identifying and testing regimens frequently resulted in poor treatment success. The described approach allows outcome to be predicted and should simplify treatment and drug development.
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Affiliation(s)
- David Y Graham
- Department of Medicine, Michael E. DeBakey VA Medical Center, and Baylor College of Medicine, Houston, Texas.
| | - Yi-Chia Lee
- Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Ming-Shiang Wu
- Department of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
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Juhász T, Matta C, Somogyi C, Katona É, Takács R, Soha RF, Szabó IA, Cserháti C, Sződy R, Karácsonyi Z, Bakó E, Gergely P, Zákány R. Mechanical loading stimulates chondrogenesis via the PKA/CREB-Sox9 and PP2A pathways in chicken micromass cultures. Cell Signal 2013; 26:468-82. [PMID: 24333667 DOI: 10.1016/j.cellsig.2013.12.001] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/28/2013] [Accepted: 12/06/2013] [Indexed: 12/15/2022]
Abstract
Biomechanical stimuli play important roles in the formation of articular cartilage during early foetal life, and optimal mechanical load is a crucial regulatory factor of adult chondrocyte metabolism and function. In this study, we undertook to analyse mechanotransduction pathways during in vitro chondrogenesis. Chondroprogenitor cells isolated from limb buds of 4-day-old chicken embryos were cultivated as high density cell cultures for 6 days. Mechanical stimulation was carried out by a self-designed bioreactor that exerted uniaxial intermittent cyclic load transmitted by the culture medium as hydrostatic pressure and fluid shear to differentiating cells. The loading scheme (0.05 Hz, 600 Pa; for 30 min) was applied on culturing days 2 and 3, when final commitment and differentiation of chondroprogenitor cells occurred in this model. The applied mechanical load significantly augmented cartilage matrix production and elevated mRNA expression of several cartilage matrix constituents, including collagen type II and aggrecan core protein, as well as matrix-producing hyaluronan synthases through enhanced expression, phosphorylation and nuclear signals of the main chondrogenic transcription factor Sox9. Along with increased cAMP levels, a significantly enhanced protein kinase A (PKA) activity was also detected and CREB, the archetypal downstream transcription factor of PKA signalling, exhibited elevated phosphorylation levels and stronger nuclear signals in response to mechanical stimuli. All the above effects were diminished by the PKA-inhibitor H89. Inhibition of the PKA-independent cAMP-mediators Epac1 and Epac2 with HJC0197 resulted in enhanced cartilage formation, which was additive to that of the mechanical stimulation, implying that the chondrogenesis-promoting effect of mechanical load was independent of Epac. At the same time, PP2A activity was reduced following mechanical load and treatments with the PP2A-inhibitor okadaic acid were able to mimic the effects of the intervention. Our results indicate that proper mechanical stimuli augment in vitro cartilage formation via promoting both differentiation and matrix production of chondrogenic cells, and the opposing regulation of the PKA/CREB-Sox9 and the PP2A signalling pathways is crucial in this phenomenon.
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Affiliation(s)
- Tamás Juhász
- Department of Anatomy, Histology and Embryology, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Csaba Matta
- Department of Anatomy, Histology and Embryology, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Csilla Somogyi
- Department of Anatomy, Histology and Embryology, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Éva Katona
- Department of Anatomy, Histology and Embryology, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Roland Takács
- Department of Anatomy, Histology and Embryology, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Rudolf Ferenc Soha
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary
| | - István A Szabó
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary
| | - Csaba Cserháti
- Department of Solid State Physics, University of Debrecen, Bem tér 18/b, H-4026 Debrecen, Hungary
| | - Róbert Sződy
- Péterfy Hospital Trauma Centre, Péterfy Sándor utca 8-20, H-1076 Budapest, Hungary
| | - Zoltán Karácsonyi
- Department of Orthopaedics, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Eva Bakó
- Department of Medical Chemistry, Medical and Health Science Centre, University of Debrecen, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Pál Gergely
- Department of Medical Chemistry, Medical and Health Science Centre, University of Debrecen, Nagyerdei krt. 98, H-4032 Debrecen, Hungary
| | - Róza Zákány
- Department of Anatomy, Histology and Embryology, University of Debrecen, Medical and Health Science Centre, Nagyerdei krt. 98, H-4032 Debrecen, Hungary.
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Di Maria F, Micale C, Sordi A, Cirulli G, Marionni M. Urban mining: quality and quantity of recyclable and recoverable material mechanically and physically extractable from residual waste. Waste Manag 2013; 33:2594-2599. [PMID: 24011783 DOI: 10.1016/j.wasman.2013.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 07/22/2013] [Accepted: 08/06/2013] [Indexed: 06/02/2023]
Abstract
The mechanically sorted dry fraction (MSDF) and Fines (<20mm) arising from the mechanical biological treatment of residual municipal solid waste (RMSW) contains respectively about 11% w/w each of recyclable and recoverable materials. Processing a large sample of MSDF in an existing full-scale mechanical sorting facility equipped with near infrared and 2-3 dimensional selectors led to the extraction of about 6% w/w of recyclables with respect to the RMSW weight. Maximum selection efficiency was achieved for metals, about 98% w/w, whereas it was lower for Waste Electrical and Electronic Equipment (WEEE), about 2% w/w. After a simulated lab scale soil washing treatment it was possible to extract about 2% w/w of inert exploitable substances recoverable as construction materials, with respect to the amount of RMSW. The passing curve showed that inert materials were mainly sand with a particle size ranging from 0.063 to 2mm. Leaching tests showed quite low heavy metal concentrations with the exception of the particles retained by the 0.5mm sieve. A minimum pollutant concentration was in the leachate from the 10 and 20mm particle size fractions.
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Abstract
The redox-inert transition metal Zn is a micronutrient that plays essential roles in protein structure, catalysis, and regulation of function. Inhalational exposure to ZnO or to soluble Zn salts in occupational and environmental settings leads to adverse health effects, the severity of which appears dependent on the flux of Zn(2+) presented to the airway and alveolar cells. The cellular toxicity of exogenous Zn(2+) exposure is characterized by cellular responses that include mitochondrial dysfunction, elevated production of reactive oxygen species, and loss of signaling quiescence leading to cell death and increased expression of adaptive and inflammatory genes. Central to the molecular effects of Zn(2+) are its interactions with cysteinyl thiols, which alters their functionality by modulating their reactivity and participation in redox reactions. Ongoing studies aimed at elucidating the molecular toxicology of Zn(2+) in the lung are contributing valuable information about its role in redox biology and cellular homeostasis in normal and pathophysiology.
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Affiliation(s)
- Weidong Wu
- School of Public Health XinXiang Medical University XinXiang, China 453003; Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Philip A Bromberg
- Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - James M Samet
- Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, U.S. EPA, Chapel Hill, NC 27514, USA.
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