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Chen Y, Liao D, Lin Y, Deng T, Yin F, Su P, Feng D. Electrochemical degradation performance and mechanism of dibutyl phthalate with hydrophobic PbO 2 electrode. CHEMOSPHERE 2022; 288:132638. [PMID: 34687678 DOI: 10.1016/j.chemosphere.2021.132638] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
A polytetrafluoroethylene (PTFE) doped PbO2 anode with a highly hydrophobicity was fabricated by electrodeposition method. In this process, vertically aligned TiO2 nanotubes (TiO2NTs) are formed by the anodic oxidation of Ti plates as an intermediate layer for PbO2 electrodeposition. The characterization of the electrodes indicated that PTFE was successfully introduced to the electrode surface, the TiO2NTs were completely covered with β-PbO2 particles and gave it a large surface area, which also limited the growth of its crystal particles. Compared with the conventional Ti/PbO2 and Ti/TiO2NTs/PbO2 electrode, the Ti/TiO2NTs/PbO2-PTFE electrode has enhanced surface hydrophobicity, higher oxygen evolution potential, lower electrochemical impedance, with more active sites, and generate more hydroxyl radicals (·OH), which were enhanced by the addition of PTFE nanoparticles. The electrocatalytic performance of the three electrodes were investigated using dibutyl phthalate (DBP) as the model pollutant. The efficiency of the DBP removal of the three electrodes was in the order: Ti/TiO2NTs/PbO2-PTFE > Ti/TiO2NTs/PbO2 > Ti/PbO2. The degradation process followed the pseudo-first-order kinetic model well, with rate constants of 0.1326, 0.1266, and 0.1041 h-1 for the three electrodes, respectively. The lowest energy consumption (6.1 kWh g-1) was obtained after 8 h of DBP treatment using Ti/TiO2NTs/PbO2-PTFE compared to Ti/TiO2NTs/PbO2 (6.7 kWh g-1) and Ti/PbO2 (7.4 kWh g-1) electrodes. Moreover, the effects of current density, initial pH and electrolyte concentration were investigated. Finally, the products of the DBP degradation process were verified based on gas chromatography-mass spectrometry analysis, and possible degradation pathways were described.
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Phuangkaew T, Booranabunyat N, Kiatkamjornwong S, Thanyasrisung P, Hoven VP. Amphiphilic quaternized chitosan: Synthesis, characterization, and anti-cariogenic biofilm property. Carbohydr Polym 2022; 277:118882. [PMID: 34893285 DOI: 10.1016/j.carbpol.2021.118882] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/07/2021] [Accepted: 11/09/2021] [Indexed: 12/25/2022]
Abstract
Hydrophobized chitosan derivatives, hexyl chitosan (HCS), dodecyl chitosan (DCS), and phthaloyl chitosan (PhCS) of approximately 30 and 50% degree of substitution (%DS) reacted with glycidyltrimethylammonium chloride (GTMAC) to incorporate hydrophilic positively charged groups of N-[(2-hydroxyl-3-trimethylammonium)propyl] and yielded amphiphilic quaternized chitosan derivatives. They can assemble into spherical nanoparticles with a hydrodynamic diameter of ~100-300 nm and positive ζ-potential values (+15 to +56). Their anti-biofilm efficacy was evaluated against the dental caries pathogen, Streptococcus mutans. Among all derivatives, the one having 30%DS of hexyl group and prepared by reacting with 1 mol equivalent of GTMAC (H30CS-GTMAC) showed the best performance in terms of its aqueous solubility, the lowest minimum inhibitory concentration (138 μg/mL) and the minimum bactericidal concentration (275 μg/mL) which are superior to the unmodified chitosan. Its equivalent anti-biofilm efficacy to that of chlorhexidine suggests that it can be a greener antibacterial agent for oral care formulations.
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Karlsen-Ayala E, Gazis R, Smith ME. Asperosporus subterraneus, a new genus and species of sequestrate Agaricaceae found in Florida nursery production. Fungal Syst Evol 2022; 8:91-100. [PMID: 35005575 PMCID: PMC8687231 DOI: 10.3114/fuse.2021.08.08] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 09/19/2021] [Indexed: 12/02/2022] Open
Abstract
We describe a novel sequestrate genus and species, Asperosporus subterraneus gen. et sp. nov., found associated with nursery production of ferns in south Florida. This truffle species has a unique combination of morphological characters among described Agaricaceae in that it lacks a stipe or columella, has large, ornamented spores, the fresh sporocarps rapidly stain pink-red when cut or bruised, and they have a rancid smell. Although this fungus does not appear to be a direct plant pathogen, the hyphae of A. subterraneus produce a thick hydrophobic mycelial mat that binds the organic matter and therefore prevents water and fertilizer from being absorbed by plants, consequently causing wilting and chlorosis. Using morphological characteristics and phylogenetic reconstruction based on the internal transcribed spacer (ITS), partial large subunit nuclear ribosomal DNA (LSU), second largest subunit of RNA polymerase II (rpb2) and translation elongation factor 1-alpha (tef1) regions, we describe this taxon as a new genus and species in Agaricaceae.
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Composite repair: On the fatigue strength of universal adhesives. Dent Mater 2022; 38:231-241. [PMID: 35027240 DOI: 10.1016/j.dental.2021.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/11/2021] [Accepted: 12/02/2021] [Indexed: 11/03/2022]
Abstract
OBJECTIVES To determine whether the composition of universal adhesives and the use of silane coupling agents could affect the fatigue strength of composite repair. METHODS Composite samples were aged in water at 37 °C for 90 days and bonded to fresh composite to produce twin-bonded bar-shaped composite specimens (2 × 2 × 12 mm). Five universal adhesives, a multistep composite repair system and a hydrophobic solvent-free resin associated to a separate silane coupling agent application were used for bonding. Composite samples were tested under 4-pointflexure initially at quasi-static loading (n = 12) followed by cyclic loading (n = 25). The stress-life fatigue behavior was evaluated following the staircase method at 4 Hz. The unfractured side of cyclic loaded beams were evaluated under SEM to determine crack initiation sites. Fatigue data was analyzed by ANOVA and Tukey test and Wilcoxon Rank Sum Test (α = 0.05). RESULTS Bonding protocols were unable to restore the cohesive strength of the nanofilled composite (p < 0.05). Fatigue testing was more discriminative to reveal discrepancies in composite repair than conventional quasi-static loading. While the composition of universal adhesives affected composite repair potential, the highest endurance limits occurred for the separate silane coupling agent application. Crack propagation sites were mostly located on the aged composite surface. SIGNIFICANCE Although a trend for simplification invariably overruns current adhesive dentistry, composite repair using solely universal adhesives may result in inferior repair potential. The additonal use of silane coupling agents remains as an important procedure in composite repairs.
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Moulod M, Moghaddam S. Insights from molecular dynamics simulations of albumin adsorption on hydrophilic and hydrophobic surfaces. J Mol Graph Model 2022; 112:108120. [PMID: 34998131 PMCID: PMC8993224 DOI: 10.1016/j.jmgm.2021.108120] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Revised: 12/21/2021] [Accepted: 12/31/2021] [Indexed: 11/26/2022]
Abstract
Protein adsorption at the surface affects the material biocompatibility directly as it is the first reaction that happens when a foreign material comes in contact with blood. In this study, the mechanism of albumin adsorption on hydrophilic and hydrophobic surfaces is investigated. Although it is studied extensively and has been of keen interest for decades, the adsorptive nature of albumin is still not fully understood with contradicting reported studies. This problem results from previous works focusing on mostly qualitative and quantitative adsorption properties of albumin, rather than the specific interaction mechanisms. The variable local surface properties across albumin can significantly impact adsorption and must be explored. In this work, the effect of hydration is found to significantly increase adsorption with minor reductions. The adsorption of albumin on hydrophilic or hydrophobic surfaces is dependent on albumin orientation, which is dictated by local charge effects. Based on these findings, an optimized material surface is proposed to minimize albumin adsorption using functional groups to limit surface availability for hydrophobic interactions while inhibiting excess electrostatic effects at hydrophilic sites. The extent of albumin adsorption and shape change are characterized herein using the heat capacity. Current study identifies interaction mechanisms previously missing in literature, which are responsible for inconsistent adsorption results.
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Satta A, Lu Z, Plan MR, Esquirol L, Ebert BE. Microbial Production, Extraction, and Quantitative Analysis of Isoprenoids. Methods Mol Biol 2022; 2469:239-259. [PMID: 35508844 DOI: 10.1007/978-1-0716-2185-1_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Isoprenoids, also known as terpenes or terpenoids, are compounds made of one or more isoprene (C5H8) moieties and constitute the largest class of natural products. They play diverse roles in biology and have broad industrial uses as flavors, fragrances, biofuels, polymers, agricultural chemicals, and medicines. Most isoprenoids are secondary plant metabolites and only produced in very low amounts. To make these valuable compounds economically accessible, significant efforts in the culture and engineering of microbial cells for isoprenoid biosynthesis have been made in the last decades. The protocols presented here describe lab-scale cultivation of microbes, either naturally producing or engineered, for isoprenoid production, the extraction of products and their quantification by high-performance liquid chromatography. Examples of isoprenoids covered in this chapter include (C10) mono-, (C15) sesqui-, (C20) di-, (C30) tri-, and (C40) tetraterpenoids. We focus on yeast and cyanobacteria as production systems, but the protocols can be adapted for other organisms.
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Zhou M, Bhatt K, Campbell G, Travis E, Skrdla P. Considerations for Defining the Intravenous Administration Procedure for Nano-dose Sterile Drug Product in Clinical Studies. J Pharm Sci 2021; 111:1911-1917. [PMID: 34922927 DOI: 10.1016/j.xphs.2021.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 12/11/2021] [Accepted: 12/11/2021] [Indexed: 11/18/2022]
Abstract
The loss of active substance, both small and large molecules, from sterile liquid drug products after contact with an administration kit has been extensively reported in the literature. This loss has been reported to be caused by incompatibility of the active substances with the contact surfaces of the administration kit and adsorption or sticking of the active substance to the surfaces of the administration kit. This paper investigates the mechanism for loss of a highly potent active substance based on the type and design of the administration kit. Two administration kits (syringe/Insyte Catheter and syringe/Nexiva Catheter) of different designs were used to administer a solution formulation of an ultra-low dose (nanograms) of a model hydrophobic active substance Compound X. The Nexiva Catheter was longer with tubing and Y connectors while the Insyte Catheter was shorter with no split septum tubing. Dose recovery from both administration kits was determined using high pressure liquid chromatography. The results indicated that the full dose was recovered from the syringes and Insyte Catheter. However, there was a significant loss of active substance from the Nexiva Catheter configuration even after post administration flush, which was due to holdup volume of the formulation within dead spaces of the Nexiva Catheter. It was also demonstrated that the dose recovery from the Nexiva Catheter can be significantly increased with increase in the post administration flush volume, which further confirms that the observed loss of active substance was not due to incompatibility or surface adsorption. The significance of this work is to provide awareness to formulation scientists that closed system Catheter design with Y connectors can be the main contributor for the loss in active substance, especially at ultra-low doses, and therefore dose recovery experiments should be expanded to include proper flushing of the Y connectors to expel any holdup volume from the Catheter.
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Ji F, Zhao Y, Jiang F, Shang D. Membrane mechanism of temporin-1CEc, an antimicrobial peptide isolated from the skin secretions of Rana chensinensis, and its systemic analogs. Bioorg Chem 2021; 119:105544. [PMID: 34953322 DOI: 10.1016/j.bioorg.2021.105544] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 11/29/2021] [Accepted: 12/04/2021] [Indexed: 12/15/2022]
Abstract
Antimicrobial peptides (AMPs) are new and powerful target molecules in the development of new antibacterial agents. Temporin-1CEc, a natural peptide isolated and purified from the skin secretions of the Chinese brown frog Rana chensinensis, exhibits low or no antibacterial activity against gram-negative and gram-positive bacteria, which limits its potential therapeutic use; however, it displays low hemolysis to human erythrocytes. Here, a series of temporin-1CEc analogs was designed and synthesized by amino acid residue substitutions based on cationicity, hydrophobicity, amphipathicity and secondary structure to understand the structure-activity relationships of this peptide in depth. The results showed that all of the analogs, except for 2K and 4K, had significantly improved antibacterial activity against the tested standard bacterial strains and multidrug-resistant bacterial strains compared to temporin-1CEc. 2K2L and 2K4L, but not 4K2L and 4K4L, showed the strongest antibacterial activity compared with their parent peptides 2K and 4K, suggesting that peptide hydrophobicity plays a more important role in antibacterial activity than cationicity for this series of AMPs. However, the antibacterial activity of the 6 Trp-containing analogs of 2K4L decreased with a further increase in hydrophobicity based on the results of 2K4L, indicating that it is more important to balance cationicity and hydrophobicity. Moreover, an increase in AMP hydrophobicity led to hemolysis. Notably, all of the peptides adopted α-helical structures in 50% trifluoroethanol/water and 30 mM SDS solutions. 2K2L and 2K4L displayed broad-spectrum antibacterial activity against sensitive and multidrug-resistant bacteria, effectively killing the tested multidrug resistant strain Staphylococcus epidermidis (MRSE1208). 2K2L and 2K4L were able to increase the permeability of the outer and inner membranes by depolarization and disturb the integration of the cytoplasmic membrane of MRSE1208 cells, leading to leakage of its cellular contents. In addition, 2K2L and 2K4L at low concentrations inhibited biofilm formation and degraded mature 1-day-old MRSE1208 biofilms. Notably, 2K2L and 2K4L inhibited the formation of MRSE1208 biofilms at concentrations below its MIC value, suggesting that the peptide may exert an inhibitory effect through not only direct antimicrobial activity but also a biofilm-specific mechanism. Collectively, these results suggest that 2K2L and 2K4L could be effective antibiotics against multidrug-resistant bacterial strains.
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Latham SG, Carr F, Ali H, Gangwani V. Clinical safety and efficacy of a preloaded monofocal hydrophobic acrylic intraocular lens in a real-world population. BMC Ophthalmol 2021; 21:379. [PMID: 34696772 PMCID: PMC8543946 DOI: 10.1186/s12886-021-02142-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 09/23/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND This study was designed to evaluate visual, refractive and safety outcomes in eyes after they underwent phacoemulsification and implantation of a preloaded monofocal hydrophobic acrylic intraocular lens. METHODS This was a single center observational study conducted at Ashford and St Peter's Hospitals NHS Foundation Trust, United Kingdom. Patients were included if they had cataract extraction with in-the-bag implantation of the EyeCee® One preloaded intraocular lens from August to October 2019. Pre-operative, surgery-related and 2 weeks and 3 months post-operative data was collected. Surgeons at this trust were then asked to complete a feedback form to evaluate their experience of implanting the EyeCee® One. RESULTS One hundred fifty-two eyes were included in the study. Ninety-four (62%) of these eyes had cataract but no concomitant ocular pathology that could potentially affect visual acuity. Three months post-operatively, 98.7% of all eyes had monocular CDVA ≤0.3 logMAR. 100% of the eyes without concomitant ocular pathology achieved this target. The mean CDVA of all eyes in this study improved from 0.43 ± 0.43 logMAR pre-operatively, to 0.05 ± 0.11 logMAR post-operatively (p < 0.05). The mean sphere and spherical equivalent values showed significant improvements (p < 0.05) and (p < 0.05). There were no intraoperative complications and 1.3% of patients reported complications 2 weeks post-operatively. All of the participating surgeons said they would use the EyeCee® One again with 64% providing an overall rating of 'excellent' for their experience of implanting this intraocular lens. CONCLUSIONS This study indicates excellent post-operative visual acuity and refractive outcomes in eyes after EyeCee® One implantation. This is accompanied with very little risk of intraoperative and post-operative complications.
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Zhou H, Tong H, Lu J, Cheng Y, Qian F, Tao Y, Wang H. Preparation of bio-based cellulose acetate/chitosan composite film with oxygen and water resistant properties. Carbohydr Polym 2021; 270:118381. [PMID: 34364623 DOI: 10.1016/j.carbpol.2021.118381] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 11/30/2022]
Abstract
Plastic pollution has inspired the preparation of environmentally friendly bio-based plastics that can replace petroleum-based plastics. Herein, a composite film with oxygen and water resistant properties was prepared by a fluidized bed method, employing bio-based cellulose acetate (CA) as raw material, glycerol as a plasticizer, and chitosan and silica as additives. The addition of 15% chitosan greatly reduced the oxygen transmission rate of the CA film by 83.5%, and increased the tensile stress and tensile strain of the composite membrane, reaching 26.5 MPa and 22.2%, respectively. The deposition of silica particles is able to compensate for the undesired increase in the hydrophilicity caused by the addition of chitosan, and tune the hydrophilic nature of the surface of the CA/CS films to the hydrophobic nature, which is desirable for water-resistant applications. The prepared composite film displays good oxygen and water resistant properties and can be used for food packaging and related applications.
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Vo HC, Pham MH. Ecotoxicological effects of microplastics on aquatic organisms: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:44716-44725. [PMID: 34226995 DOI: 10.1007/s11356-021-14982-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Microplastics ( <5 mm), which are classified based on primary or secondary sources, are widely distributed in the environment and exert significant effects on aquatic life forms; however, evidence regarding the ecotoxicological effects of microplastics on aquatic organisms is still limited. This research aims at filling a knowledge gap regarding generation sources, distribution, physicochemical properties, and biological behavior of microplastics (MP) in aquatic environments and their interaction with aquatic organisms. The literature indicates that concentrations of MPs observed in such environments are higher than the threshold for safe concentration (6650 buoyant particles/m3). MPs having large specific surface area, low polarity, and hydrophobic properties have been shown to absorb dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbon (PAHs), bisphenol A (BPA), polyfluoroalkyl substances (PFAS), antibiotics, and heavy metals. MPs adsorb large amounts of toxic organic chemicals (18,700 ng/g PCBs; 24,000 ng/g PAHs) and heavy metals (0.21-430 μg/g Cr; 0.0029-930 μg/g Cd; 0.35-2.89 μg/g As; 0.26-698,000 μg/g Pb). MPs originating from polystyrene (PS), polypropylene (PP), and polyvinylchloride (PVC) show greater toxicity toward aquatic organisms, with effects on the immune system, reproductive system, nervous system, and endocrine system. Thus, elucidating the cumulative toxic expression of MPs in different polluted environments is critical.
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Laddha H, Pawar PR, Prakash G. Bioconversion of waste acid oil to docosahexaenoic acid by integration of "ex novo'' and "de novo'' fermentation in Aurantiochytrium limacinum. BIORESOURCE TECHNOLOGY 2021; 332:125062. [PMID: 33839510 DOI: 10.1016/j.biortech.2021.125062] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 06/12/2023]
Abstract
Thraustochytrids have predominantly been grown on hydrophilic substrates i.e. by "de novo" fermentation. The fatty acid composition of thraustochytrids oil in "de novo" mode is enriched in saturated palmitic acid and polyunsaturated docosahexaenoic acid. The "ex novo" fermentation of a novel Aurantiochytrium limacinum ICTSG-17 with waste acid oil altered the fatty acid composition of produced oil. This led to increased total unsaturated fatty acids (TUFA) and concomitant decrease in the total saturated fatty acids (TSFA) resulting in higher TUFA/TSFA ratio. However, cell growth and DHA content in "ex novo" were lower than that of "de novo" fermentation. Integration of "de novo" and "ex novo" fermentation modes were devised to attain high biomass and lipids enriched in DHA. Sequential "de novo"-"ex novo" fermentation resulted in ~20 g/L biomass and ~40% DHA content and higher TUFA/TSFA ratio as compared to that of "de novo" mode.
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Goswami S, Shenoy NS, Mistry KA, Gupta S, Sharma VK, Bhanja K, Pant HJ. Residence time distribution study in a pilot-scale liquid phase catalytic exchange (LPCE) column packed with a mixture of hydrophobic and hydrophilic catalysts. Appl Radiat Isot 2021; 176:109840. [PMID: 34256272 DOI: 10.1016/j.apradiso.2021.109840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/01/2021] [Accepted: 06/21/2021] [Indexed: 10/21/2022]
Abstract
Residence time distribution (RTD) measurements were carried out in a packed bed column designed for exchange of hydrogen isotopes. The main objective of the study was to characterize the liquid phase mixing under various processes and operating conditions. The packed bed was composed of a mixture of two different types of catalytic packing materials, i.e., a hydrophobic material and a hydrophilic material. Technitium-99m (99mTc) as sodium pertechnetate was used as a radiotracer for RTD measurements. From the measured RTD curves, mean residence times (MRTs), liquid holdup and degree of mixing of liquid phase were evaluated. An axial dispersion model exchange with stagnant zones was used to simulate the measured RTD curves. The results of model simulation showed that volume fraction of hydrophobic to hydrophilic packing and gas/liquid superficial velocities affect the liquid holdup, bed pressure drop and liquid phase dispersion/mixing characteristics. The results of the present study will help to screen packing, optimize the volume of the packing fractions, design and construct the catalyst and optimize the operating conditions for scale up of the isotope exchange process.
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He X, Chen T, Jiang T, Wang C, Luan Y, Liu P, Liu Z. Preparation and adsorption properties of magnetic hydrophobic cellulose aerogels based on refined fibers. Carbohydr Polym 2021; 260:117790. [PMID: 33712138 DOI: 10.1016/j.carbpol.2021.117790] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 01/14/2023]
Abstract
A novel approach was introduced to prepare very low density, highly porous, economic, reusable, hydrophobic, and magnetic cellulose aerogels from hardwood dissolving pulp via a simple freeze-drying procedure. The aerogels showed outstanding adsorption efficiency for several oils and organic solvents and demonstrated excellent selectivity for absorbing oil from an oil/water mixture. Moreover, they were easily collected by an external magnet, indicating excellent recyclability and reusable for at least 10 cycles while still retaining supreme adsorption capacity (up to 181 g/g for silicone oil). This study proposes an economic and novel method for the large-scale preparation of hydrophobic and magnetic cellulose aerogels, making them a promising candidate for the efficient and sustainable cleaning of oils and chemical spills.
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Akpomie KG, Conradie J. Enhanced surface properties, hydrophobicity, and sorption behavior of ZnO nanoparticle-impregnated biomass support for oil spill treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:25283-25299. [PMID: 33453027 DOI: 10.1007/s11356-021-12451-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
Metallic nanoparticles (NPs) have gained significant attention in recent years due to their efficiency in the adsorption of water pollutants. Except for magnetic NPs, metallic NPs are rarely used in oil sorption studies, due to the difficulty in recovering the NPs from the treated water. This study reports for the first time the application of ZnONPs for oil spill treatment. The ZnONPs were impregnated onto Musa acuminata peel (MP) support to form a novel material (ZnOMP), which was utilized for the sorption of oil from synthetic oil spills. The as-prepared sorbents were characterized by the SEM, EDS, BET, FTIR, FE-SEM, TGA, and XRD techniques. The presence of 31.32-nm average-sized ZnONPs enhanced the oil uptake characteristics, with clear affinity for the oil phase in comparison to the pristine MP. A maximum sorption capacity of 4.146 g/g and 5.236 g/g was obtained for biosorbents MP and ZnOMP, respectively, which was higher than most reported sorbents. The Freundlich model presented the best fit for the isotherm data, while the pseudo-second-order model was most suited for the kinetics. The presence of competing heavy metal ions in solution did not have any significant effect on the oil sorption capacity onto ZnOMP. The sorption mechanism was attributed to absorption and hydrophobic interactions. ZnONPs impregnated onto the biomass enhanced the spontaneity of oil uptake at higher temperatures. Over 82% desorption of the oil contaminant from the biosorbents was achieved during recovery, using petroleum ether and n-pentane as eluents. Concisely, ZnONPs enhanced the uptake and hydrophobic characteristic of MP biomass and showed good recovery and reusability. Thus, the application of ZnONPs impregnated onto biosorbents in oil spill treatment is highly recommended.
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Niemuth N, Williams DN, Mensch AC, Cui Y, Orr G, Rosenzweig Z, Klaper RD. Redesign of hydrophobic quantum dots mitigates ligand-dependent toxicity in the nematode C. elegans. NANOIMPACT 2021; 22:100318. [PMID: 35559975 DOI: 10.1016/j.impact.2021.100318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/22/2021] [Accepted: 04/12/2021] [Indexed: 06/15/2023]
Abstract
Surface properties of engineered nanomaterials (ENMs) have been shown to influence their interaction with biological systems. However, studies to date have largely focused on hydrophilic materials, likely due to biocompatibility concerns and aqueous exposure conditions necessary for many model systems. Therefore, a knowledge gap exists in nanotoxicity literature for impacts of hydrophobic ENMs, with studies of hydrophobic materials largely limited to carbon ENMs. Here we demonstrate testing of hydrophobic quantum dots (QDs) using the nematode C. elegans, a model soil organism cultured on solid media and amenable to hydrophobic exposures. To evaluate the influence of hydrophobicity, we compared CdSe/ZnS QDs functionalized with hydrophobic trioctylphosphine oxide (TOPO) to identical QDs functionalized with hydrophilic dihydrolipoic acid-polyethylene glycol (DHLA-PEG) and alternative hydrophobic CdSe/ZnS QDs functionalized with oleic acid (OA). Results show that hydrophobic TOPO QDs are significantly more toxic than hydrophilic DHLA-PEG QDs, and substitution of TOPO with OA yields relatively non-toxic hydrophobic QDs. Fluorescence microscopy shows TOPO QDs loosely associated with the organism's cuticle, but atomic force microscopy shows no difference in cuticle structure from exposure. Importantly, TOPO ligand alone is as toxic as TOPO QDs, and our data suggests that TOPO may impact neuromuscular function, perhaps upon displacement from the QD surface. This study demonstrates the importance of examining ligand-specific impacts of hydrophobic ENMs and indicates OA-functionalized QDs as a potential alternative to TOPO QDs for reduced toxicity.
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Yang Y, Zhou H, Xiao Y, Feng L, Yang L, Mu W, Peng X, Bao L, Wang J. Hydrophobic thermoplastic starch supramolecularly-induced by a functional sucrose based ionic liquid crystal. Carbohydr Polym 2021; 255:117363. [PMID: 33436196 DOI: 10.1016/j.carbpol.2020.117363] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/13/2020] [Accepted: 11/01/2020] [Indexed: 11/16/2022]
Abstract
It is still a big challenge to obtain hydrophobic thermoplastic starch with outstanding mechanical performance due to the inevitable usage of typical hydrophilic plasticizers like glycerol during processing. Herein, we report a novel hydrophobic thermoplastic starch using a supramolecularly induced thermoplasticization technique. To achieve this aim, a functional sucrose-based ionic liquid crystal (ILC) including numerous chloride atoms has been firstly synthesized, and the obtained ILC molecules are then used as supramolecular inducers to thermoplasticize corn starch granules. Thermoplasticity and hydrophobicity of the prepared supramolecularly induced thermoplastic starch (STPS) with different ILC contents have been extensively investigated. Mechanism of the supramolecularly induced thermoplasticization has been investigated using molecular simulation as well. The prepared STPS with the maximum tensile strength of 8.4 MPa and water contact angle of about 117° show large potential applications in green and sustainable packaging materials.
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Semilin V, Janaun J, Chung CH, Touhami D, Haywood SK, Chong KP, Yaser AZ, Zein SH. Recovery of oil from palm oil mill effluent using polypropylene micro/nanofiber. JOURNAL OF HAZARDOUS MATERIALS 2021; 404:124144. [PMID: 33212411 DOI: 10.1016/j.jhazmat.2020.124144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/31/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
Residual palm oil that goes into the river untreated can become detrimental to the environment. Residual oil discharge during milling process into palm oil mill effluent (POME) is unavoidable. About 1 wt% of residual oil in POME causes major problems to the mills, in terms of environment, wastewater treatment and economy losses. This paper reports the recovery of residual oil from POME by adsorption on polypropylene micro/nanofiber (PP-MNF) and desorption of oil by hands pressing, and oil extraction from the PP-MNF using solvent and supercritical-CO2 extraction techniques. The characterization of the PP-MNF and the quality of oil extracted were analyzed using analytical instruments. The reusability of the PP-MNF was also investigated. The experimental results showed the adsorption capacity of the PP-MNF was 28.65 g of oil/g of PP-MNF on average using refined palm oil, whilst recovery of oil from POME was 10.93 g of oil/g of PP-MNF. The extraction yield of oil from PP-MNF using hand pressing was 89.62%. The extraction of residual oil from the pressed PP-MNF showed comparable yield between solvent and supercritical CO2 techniques. The quality of recovered oil was similar with the quality of the crude oil, and no trace of polypropylene contamination was detected in the oil recovered. The PP-MNF showed no significant physical change after the extraction process. In conclusion, the PP-MNF has great potential to be used commercially in residual oil recovery from POME.
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Effect of sodium bicarbonate and sodium chloride on aggregation and conformation of pork myofibrillar protein. Food Chem 2021; 350:129233. [PMID: 33592363 DOI: 10.1016/j.foodchem.2021.129233] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 11/23/2022]
Abstract
To investigate the effect of sodium bicarbonate instead of sodium chloride, the changes in pH, turbidity, aggregation, and conformation of myofibrillar protein solution with various amounts of sodium chloride and sodium bicarbonate were studied. When the sodium bicarbonate was increased from 0% to 0.4%, accompanied by the sodium chloride being decreased from 2.0% to 0.8%, the pH increased about 1.20 unites; the absolute values of the Zeta potential, active sulfhydryl, and surface hydrophobicity increased significantly (p < 0.05); and the turbidity, particle size, and Ca2+-ATPase activity decreased significantly (p < 0.05). In addition, the Mg2+-ATPase activity was not significantly different (p > 0.05) when increasing sodium bicarbonate, implying that sodium bicarbonate did not affect the actin. Overall, the results indicated that an increase in sodium bicarbonate could improve solubility, expose more hydrophobic residues and sulfhydryl groups, and induce Ca2+-ATPase inactivation and protein unfolding, leading the myofibrillar protein to denaturation easily.
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Singh RK, Malosse C, Davies J, Malissen B, Kochba E, Levin Y, Birchall JC, Coulman SA, Mous J, McAteer MA, Dayan CM, Henri S, Wong FS. Using gold nanoparticles for enhanced intradermal delivery of poorly soluble auto-antigenic peptides. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2021; 32:102321. [PMID: 33184020 DOI: 10.1016/j.nano.2020.102321] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/08/2020] [Accepted: 10/10/2020] [Indexed: 12/14/2022]
Abstract
Ultra-small 1-2 nm gold nanoparticles (NP) were conjugated with a poorly-soluble peptide auto-antigen, associated with type 1 diabetes, to modify the peptide pharmacokinetics, following its intradermal delivery. Peptide distribution was characterized, in vivo, after delivery using either conventional intradermal injection or a hollow microneedle device. The poorly-soluble peptide was effectively presented in distant lymph nodes (LN), spleen and draining LN when conjugated to the nanoparticles, whereas peptide alone was only presented in the draining LN. By contrast, nanoparticle conjugation to a highly-soluble peptide did not enhance in vivo distribution. Transfer of both free peptide and peptide-NPs from the skin to LN was reduced in mice lacking lymphoid homing receptor CCR7, suggesting that both are actively transported by migrating dendritic cells to LN. Collectively, these data demonstrate that intradermally administered ultra-small gold nanoparticles can widen the distribution of poorly-soluble auto-antigenic peptides to multiple lymphoid organs, thus enhancing their use as potential therapeutics.
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Pine KR, De Silva K, Zhang F, Yeoman J, Jacobs R. Towards improving the biocompatibility of prosthetic eyes. Heliyon 2021; 7:e06234. [PMID: 33665419 PMCID: PMC7903304 DOI: 10.1016/j.heliyon.2021.e06234] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/03/2020] [Accepted: 02/05/2021] [Indexed: 11/30/2022] Open
Abstract
Prosthetic eyes are currently manufactured using Poly(methyl methacrylate) (PMMA) which is not an ideal material because it is hydrophobic. While significant research has investigated the benefits of hydrophilic materials for contact lenses, no such research has been carried out on hydrophilic materials for prosthetic eyes until now. In this study, different derivatives of Poly(ethylene glycol) (PEG) monomer and methyl methacrylate (MMA) monomer were grafted to PMMA using copolymerisation. The resulting matrixes were evaluated by water contact angle measurement, 24 h water absorption testing, and colour-difference measurement when exposed to ultraviolet light. The contact angle and water absorption results indicated that ethylene glycol dimethacrylate (EGDMA) grafted PMMA matrix had a better hydrophilic performance than the other matrixes tested. EGDMA is already a minor constituent of the PMMA matrix currently used for manufacturing prosthetic eyes but when the proportion of EGDMA monomer to MMA monomer used in the manufacturing process was increased to 50/50 the hydrophilicity of the matrix was significantly improved. EGDMA-grafted PMMA is inexpensive and comes as a liquid monomer that is easily mixed with the PMMA monomer that ocular prosthetists are familiar with. The mixture requires no special handling beyond the normal safety precautions that apply when using PMMA monomers. In-vitro testing shows that EGDMA-grafted PMMA significantly improves the wettability of PMMA currently used for the manufacture of prosthetic eyes and has the potential to significantly improve wearing comfort and socket health.
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Ma J, Zhao Y, Liu W, Song P, Yang L, Wei J, Yang F, Wang X. Fabrication and Characterization of Black GaAs Nanoarrays via ICP Etching. NANOSCALE RESEARCH LETTERS 2021; 16:15. [PMID: 33475898 PMCID: PMC7818367 DOI: 10.1186/s11671-021-03479-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
GaAs nanostructures have attracted more and more attention due to its excellent properties such as increasing photon absorption. The fabrication process on GaAs substrate was rarely reported, and most of the preparation processes are complex. Here, we report a black GaAs fabrication process using a simple inductively coupled plasma etching process, with no extra lithography process. The fabricated sample has a low reflectance value, close to zero. Besides, the black GaAs also displayed hydrophobic property, with a water contact angle of 125°. This kind of black GaAs etching process could be added to the fabrication workflow of photodetectors and solar cell devices to further improve their characteristics.
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Tang Q, Chen W, Dai X, Liu Y, Liu H, Fan L, Luo H, Ji L, Zhang K. Exploring the perspective of nano-TiO 2 in hydrophobic modified cationic flocculant preparation: Reaction kinetics and emulsified oil removal performance. CHEMOSPHERE 2021; 263:128066. [PMID: 33297071 DOI: 10.1016/j.chemosphere.2020.128066] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/16/2020] [Accepted: 08/18/2020] [Indexed: 06/12/2023]
Abstract
To reduce the polymerization difficulty of hydrophobic modified copolymers, a hydrophobic modified cationic flocculant was fabricated using nano-TiO2 as initiator with acrylamide (AM) and methyl acryloxyethyl dimethyl benzyl ammonium chloride (DML) as monomers, and named it PAD. The copolymers were characterized by scanning electron microscopy (SEM), nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TG). Results verified that PAD was synthesized successfully and nano-TiO2 was more conducive to DML grafting than traditional photo-initiators. Reaction kinetics demonstrated that the polymerization process was a typical precipitation polymerization initiated by free radicals. Flocculation performance of flocculant on simulated emulsified oil was evaluated and optimized. The simulation results indicated that the flocculation performance of PAD was superior to traditional flocculant, which was attributed to the higher content of DML in PAD. The maximum removal rate of emulsified oil could reach 92.10%, and the corresponding turbidity removal rate was 93.54%. Further, the mechanism studies suggested that the removal of emulsified oil was realized by the synergistic effects of electric neutralization, demulsification, hydrophobic association and adsorption bridging. The findings of this study showed that nano-TiO2 exhibited a promising prospect in the field of polymer-initiated polymerization.
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Borkenstein AF, Borkenstein EM. Analysis of YAG Laser-Induced Damage in Intraocular Lenses: Characterization of Optical and Surface Properties of YAG Shots. Ophthalmic Res 2020; 64:417-431. [PMID: 33221803 DOI: 10.1159/000513203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 11/15/2020] [Indexed: 01/19/2023]
Abstract
PURPOSE To assess differences in neodymium:yttrium aluminum garnet (Nd:YAG)-induced defects in hydrophilic and hydrophobic intraocular lenses (IOLs) and describe optical and surface properties of YAG shots/pitting. Describing and measuring the iatrogenic produced defects should achieve higher awareness on this topic and change the mindset of such a trivial procedure to be proceeded with more caution and calmness in the future. MATERIALS Twelve IOLs from different manufacturers made of hydrophilic and hydrophobic materials were evaluated before and after treatment with the Nd:YAG laser. Microscopy and environmental scanning electron microscopic (ESEM) images were used to visually analyze the defects. Additionally, wavefront measurements were taken for power mapping and Raman spectroscopy was performed. Vertical and horizontal dimensions of the defects were analyzed and compared, and Raman line scans assessed the changes in the chemical structure in the defect area of the IOL. RESULTS Microscopically, pitting of the surface could be observed in both lens types. Defects in hydrophobic lenses appeared bigger and were visible with less magnification than in hydrophilic lenses. Similar results were obtained with ESEM images where the defects in hydrophobic IOLs seemed to be frayed while defects in hydrophilic IOLs were of circular shape. Raman spectroscopy revealed deeper defects in hydrophobic lenses. Vertical dimensions of the defects were statistically significant (p = 0.036) and greater in hydrophobic materials while horizontal dimensions did not reach significance (p = 0.056). The area of chemical changes was greater than the visible defect area and smaller in hydrophilic than that in hydrophobic materials. CONCLUSION Nd:YAG seems to have greater impact on hydrophobic IOL materials as that damage was greater and more frayed than that in hydrophilic materials. Moreover, there seems to be larger, distinctive damage area in IOLs (with chemical changes in the material) than that is visually recognizable. Therefore, a very cautious approach is recommended when performing capsulotomy, as defects in the surface structure can occur. This might come along with problems in quality of vision in monofocal and primarily premium IOLs (multifocal, enhanced depth of focus, and toric IOLs), dependent on the size, dimension, and position in the IOL. YAG capsulotomy should not be considered trivial but should be carried out with precision and without time pressure, just like surgery itself.
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Yin Z, Sun X, Bao M, Li Y. Construction of a hydrophobic magnetic aerogel based on chitosan for oil/water separation applications. Int J Biol Macromol 2020; 165:1869-1880. [PMID: 33086115 DOI: 10.1016/j.ijbiomac.2020.10.068] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/23/2020] [Accepted: 10/10/2020] [Indexed: 02/01/2023]
Abstract
Hydrophobic/oleophilic absorbents have been largely studied and used in recovering spilled oil. However, they still suffer from several drawbacks and two of them are poor biocompatibility and hard to thoroughly rinse. In order to address these problems, here a hydrophobic magnetic chitosan-based aerogel is fabricated via electrostatic interactions between chitosan (CS), itaconic acid (IA) and Fe3O4 nanoparticles and dip-coating in ethanol solution of Candelilla wax (CW). Due to the interconnected porous structure of chitosan-based aerogel, the magnetism of Fe3O4 nanoparticles and the hydrophobicity of CW, the prepared aerogel exhibits high absorption capacities (from 17.7 to 43.8 g/g) towards various types of organic liquids, excellent magnetic controllability with saturation magnetization of 15.93 emu/g and good water repellency with water contact angle (WCA) of 147.9°. In addition, the aerogel can also continuously separate immiscible oil/water mixtures and water-in-oil emulsions as the form of filter. More significantly, the absorbed organic liquids can be completely recovered by simply placing the aerogel in water solution of IA at 75 °C, which can avoid cleaning agent consumption. As a consequence, this renewable, biodegradable and eco-friendly oil scavenger presents a bright prospect in practical applications.
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