1
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Poole CF. Assessment of liquid-liquid partition for the assignment of descriptors for the solvation parameter model. J Chromatogr A 2024; 1721:464850. [PMID: 38564932 DOI: 10.1016/j.chroma.2024.464850] [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: 03/09/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024]
Abstract
The solvation parameter model uses five system independent descriptors to characterize compound properties defined as excess molar refraction, E, dipolarity/polarizability, S, hydrogen-bond acidity, A, hydrogen-bond basicity, B, and McGowan's characteristic volume, V, to model transfer properties between condensed phases. The V descriptor is assigned from structure. For compounds liquid at 20 °C the E descriptor can be assigned from the characteristic volume and its refractive index. The E descriptor for compounds solid at 20 °C and the S, A, and B descriptors are experimental properties traditionally assigned from chromatographic, liquid-liquid partition, and solubility measurements. In this report liquid-liquid partition constants in totally organic and aqueous biphasic systems are evaluated as a standalone technique for descriptor assignments. Using six totally organic biphasic systems the S, A, and B descriptors were assigned with an average absolute deviation (AAD) of about 0.04, 0.03, and 0.04, respectively, compared with the best estimate of the true descriptor values for 65 compounds. The E descriptor for compounds solid at 20 °C can only be estimated with an AAD of approximately 0.1. For six aqueous biphasic systems the B descriptor is assigned with a lower AAD of 0.028 and higher AAD of 0.08 and 0.05 for the S and A descriptors, respectively, than for the totally organic biphasic systems for compounds with a reliable value for the E descriptor. The preferred system for descriptor assignments utilizes both totally organic biphasic systems (heptane-1,1,1-trifluoroethanol, isopentyl ether-propylene carbonate, isopentyl ether-ethanolamine, heptane-ethylene glycol, heptane-formamide, and 1,2-dichloroethane-ethylene glycol) and aqueous biphasic systems (octanol-water, cyclohexane-water) with the possible substitution of some systems with alternative systems of similar selectivity. For 55 varied compounds this combination of eight organic and aqueous biphasic systems resulted in an AAD of approximately 0.03, 0.02, and 0.02 for the S, A, and B descriptors compared to the best estimate of the true descriptor value. For 30 compounds solid at 20 °C the AAD for the E descriptor of 0.11 is poorly assigned. The relative average absolute deviation in percent (RAAD) corresponds to 9.7 %, 3.1 %. 4.0 % and 8.3 % for E, S, A, and B, respectively, for the eight biphasic systems. Liquid-liquid partition is compared to reversed-phase liquid and gas chromatography as a standalone technique for descriptor assignments.
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Affiliation(s)
- Colin F Poole
- Department of Chemistry, Wayne State University, Detroit, MI 48202, USA.
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Zheng Y, Huang W, Dhungana RK, Granados A, Keess S, Makvandi M, Molander GA. Photochemical Intermolecular [3σ + 2σ]-Cycloaddition for the Construction of Aminobicyclo[3.1.1]heptanes. J Am Chem Soc 2022; 144:23685-23690. [PMID: 36523116 PMCID: PMC10413992 DOI: 10.1021/jacs.2c11501] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The development of synthetic strategies for the preparation of bioisosteric compounds is a demanding undertaking in medicinal chemistry. Numerous strategies have been developed for the synthesis of bicyclo[1.1.1]pentanes (BCPs), bridge-substituted BCPs, and bicyclo[2.1.1]hexanes. However, progress on the synthesis of bicyclo[3.1.1]heptanes, which serve as meta-substituted arene bioisosteres, has not been previously explored. Herein, we disclose the first photoinduced [3σ + 2σ] cycloaddition for the synthesis of trisubstituted bicyclo[3.1.1]heptanes using bicyclo[1.1.0]butanes and cyclopropylamines. This transformation not only uses mild and operationally simple conditions but also provides unique meta-substituted arene bioisosteres. The applicability of this method is showcased by simple derivatization reactions.
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Affiliation(s)
- Yongxiang Zheng
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Weichen Huang
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Roshan K. Dhungana
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Albert Granados
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Sebastian Keess
- Medicinal Chemistry Department, Neuroscience Discovery Research, AbbVie Deutschland GmbH & Co. KG, 67061 Ludwigshafen, Germany
| | - Mehran Makvandi
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Gary A. Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States
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Frank N, Nugent J, Shire BR, Pickford HD, Rabe P, Sterling AJ, Zarganes-Tzitzikas T, Grimes T, Thompson AL, Smith RC, Schofield CJ, Brennan PE, Duarte F, Anderson EA. Synthesis of meta-substituted arene bioisosteres from [3.1.1]propellane. Nature 2022; 611:721-726. [PMID: 36108675 DOI: 10.1038/s41586-022-05290-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Accepted: 08/30/2022] [Indexed: 11/08/2022]
Abstract
Small-ring cage hydrocarbons are popular bioisosteres (molecular replacements) for commonly found para-substituted benzene rings in drug design1. The utility of these cage structures derives from their superior pharmacokinetic properties compared with their parent aromatics, including improved solubility and reduced susceptibility to metabolism2,3. A prime example is the bicyclo[1.1.1]pentane motif, which is mainly synthesized by ring-opening of the interbridgehead bond of the strained hydrocarbon [1.1.1]propellane with radicals or anions4. By contrast, scaffolds mimicking meta-substituted arenes are lacking because of the challenge of synthesizing saturated isosteres that accurately reproduce substituent vectors5. Here we show that bicyclo[3.1.1]heptanes (BCHeps), which are hydrocarbons for which the bridgehead substituents map precisely onto the geometry of meta-substituted benzenes, can be conveniently accessed from [3.1.1]propellane. We found that [3.1.1]propellane can be synthesized on a multigram scale, and readily undergoes a range of radical-based transformations to generate medicinally relevant carbon- and heteroatom-substituted BCHeps, including pharmaceutical analogues. Comparison of the absorption, distribution, metabolism and excretion (ADME) properties of these analogues reveals enhanced metabolic stability relative to their parent arene-containing drugs, validating the potential of this meta-arene analogue as an sp3-rich motif in drug design. Collectively, our results show that BCHeps can be prepared on useful scales using a variety of methods, offering a new surrogate for meta-substituted benzene rings for implementation in drug discovery programmes.
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Affiliation(s)
- Nils Frank
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Jeremy Nugent
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Bethany R Shire
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Helena D Pickford
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Patrick Rabe
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Alistair J Sterling
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Tryfon Zarganes-Tzitzikas
- Alzheimer's Research UK Oxford Drug Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, Oxford, UK
| | - Thomas Grimes
- Alzheimer's Research UK Oxford Drug Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, Oxford, UK
| | - Amber L Thompson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Russell C Smith
- Abbvie Drug Discovery Science & Technology (DDST), North Chicago, IL, USA
| | | | - Paul E Brennan
- Alzheimer's Research UK Oxford Drug Discovery Institute, Centre for Medicines Discovery, Nuffield Department of Medicine, Oxford, UK
| | - Fernanda Duarte
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK
| | - Edward A Anderson
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford, UK.
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Shin C, Kim DG, Kim JH, Kim JH, Song MK, Oh KS. Migration of substances from food contact plastic materials into foodstuff and their implications for human exposure. Food Chem Toxicol 2021; 154:112373. [PMID: 34182045 DOI: 10.1016/j.fct.2021.112373] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 04/19/2021] [Revised: 06/16/2021] [Accepted: 06/23/2021] [Indexed: 12/14/2022]
Abstract
The safety of food contact plastic materials, including PP, PE, PET, PCT, PLA, PBT and cross-linked polyester, was assessed with regard to migrated substances. The migrated concentrations of overall migrants (OMs), terephthalic acid, acetaldehyde, 1,4-butanediol and lead, were determined according to the standards and specifications for utensils, containers and packages in Korea. Food simulants of 4% acetic acid, water and n-heptane were used for the analysis of the substances. The dietary exposures of terephthalic acid, acetaldehyde and 1,4-butanediol were assessed using the dietary concentrations and the food consumption data. As a result, the dietary exposures were considered to be safe comparing to the health-based guidance values. In the case of lead, the margin of exposure (MOE) approach was applied. The MOEs calculated using the UB concentration and mean consumption data were ranged from 3 to 1000, which indicated low concern for health risk. Moreover, in this study, the dietary exposures were estimated by the Korean MFDS and U.S. FDA methods, respectively. As a result, the assessed risks were considered to be low in both cases. Based on the results of current exposure assessments, it could be considered that the food contact plastic materials are properly controlled by the regulatory authorities.
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Affiliation(s)
- Choonshik Shin
- Food Additives Standard Division, Food Standard Planning Office, Ministry of Food and Drug Safety, Osong, Cheongju, 28159, Republic of Korea.
| | - Dong-Gyu Kim
- Food Additives Standard Division, Food Standard Planning Office, Ministry of Food and Drug Safety, Osong, Cheongju, 28159, Republic of Korea
| | - Jun-Hyun Kim
- Food Additives Standard Division, Food Standard Planning Office, Ministry of Food and Drug Safety, Osong, Cheongju, 28159, Republic of Korea
| | - Jun Ho Kim
- Hygiene Safety Center, Korea Conformity Laboratories, Geumcheon-gu, Seoul, 08503, Republic of Korea.
| | - Min-Kyung Song
- Korea Natural Resource & Economic Research Institute, Seongdong-gu, Seoul, 04793, Republic of Korea
| | - Keum-Soon Oh
- Food Additives Standard Division, Food Standard Planning Office, Ministry of Food and Drug Safety, Osong, Cheongju, 28159, Republic of Korea
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Królikowska M, Królikowski M, Domańska U. Effect of Cation Structure in Quinolinium-Based Ionic Liquids on the Solubility in Aromatic Sulfur Compounds or Heptane: Thermodynamic Study on Phase Diagrams. Molecules 2020; 25:molecules25235687. [PMID: 33276551 PMCID: PMC7731319 DOI: 10.3390/molecules25235687] [Citation(s) in RCA: 3] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/11/2020] [Accepted: 12/01/2020] [Indexed: 11/16/2022] Open
Abstract
Experimental and theoretical studies on thermodynamic properties of quinolinium-based ionic liquids (ILs) based on bis(trifluoromethylsulfonyl)imide anion (namely N-butyl-quinoloinium bis(trifluoromethylsulfonyl)imide, [BQuin][NTf2], N-hexylquinoloinium bis(trifluoromethyl-sulfonyl)imide, [HQuin][NTf2], and N-octylquinoloinium bis(trifluoromethyl-sulfonyl)imide, [OQuin][NTf2]) with aromatic sulfur compounds and heptane, as a model compound of fuel were examined in order to assess the applicability of the studied ionic liquids for desulfurization of fuels. With this aim, the temperature-composition phase diagrams of 13 binary mixtures composed of organic sulfur compounds (thiophene, benzothiophene, or 2-methylthiophene) or heptane and ionic liquid (IL) were investigated at ambient pressure. A dynamic method was used to determine the (solid-liquid) equilibrium phase diagrams in binary systems over a wide composition range and temperature range from T = 255.15 to 365.15 K up to the fusion temperature of ILs. The immiscibility gap with an upper critical solution temperature (UCST) was observed for each binary system under study. The influence of the alkane chain length of the substituent on the IL cation and of the sulfur compounds (the aromaticity of the solvent) was described. The experimental (solid + liquid) phase equilibrium dataset were successfully correlated using the well-known NRTL equation.
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Affiliation(s)
- Marta Królikowska
- Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland;
- Thermodynamics Research Unit, School of Chemical Engineering, University of KwaZulu-Natal, Howard College Campus, King George V Avenue, Durban 4041, South Africa
- Correspondence:
| | - Marek Królikowski
- Department of Physical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland;
- Thermodynamics Research Unit, School of Chemical Engineering, University of KwaZulu-Natal, Howard College Campus, King George V Avenue, Durban 4041, South Africa
| | - Urszula Domańska
- Thermodynamics Research Unit, School of Chemical Engineering, University of KwaZulu-Natal, Howard College Campus, King George V Avenue, Durban 4041, South Africa
- ŁUKASIEWICZ Research Network—Industrial Chemistry Institute, Rydygiera 8, 01-793 Warsaw, Poland;
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6
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García-Camacha Gutiérrez I, Martín Martín R, Sanz Argent J. Optimal-robust selection of a fuel surrogate for homogeneous charge compression ignition modeling. PLoS One 2020; 15:e0234963. [PMID: 32584832 PMCID: PMC7316266 DOI: 10.1371/journal.pone.0234963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 06/07/2020] [Indexed: 11/23/2022] Open
Abstract
Homogeneous Charge Compression Ignition (HCCI) combustion is a potential candidate for dealing with the stringent regulations on vehicle emissions while still providing very good energy efficiency. Despite the promising results obtained in preliminary studies, the lack of autoignition control has delayed its launch in the engine industry. In the development of the HCCI concept, the availability of reliable computer models has proved extremely valuable, due to their flexibility and lower cost compared with experiments using real engines. In order to obtain the best formulation of a fuel surrogate formulated with n-heptane, toluene and cyclohexane that efficiently estimate the autoignition behaviour, regression adjustments are made to the Root-Mean-Square Errors (RMSE) of experimental Starts of Combustion (SOC) from the modeled SOC. The canonical form of the Scheffé polynomials is widely used to fit the data from mixture experiments, however the experimenter might have only partial knowledge. In this paper we present the adaptation of the robust methodology for possibly misspecified blending model and an algorithm to obtain tailor-made optimal designs for mixture experiments, instead of using standard designs which are indiscriminately employed, to make good estimations of the parameters blending model. We maximize the determinant of the mean squared error matrix of the least square estimator over a realistic neighbourhood of the fitted regression mixture model. The maximized determinant is then minimized over the class of possible designs, yielding an optimal design. Thus, the computed desings are robust to the exact form of the true blending model. Standard mixture designs, as the simplex lattice, are around 25% efficient for estimation purposes compared with the designs obtained in this work when deviances from the considered model occur during the experiments. Once an optimal-robust design was selected (based on the level of certainty about model adequacy), we computed the optimal mixture that best reproduces the combustion property to be imitated. Optimal mixtures obtained when the considered model is inadequate agree with the results achieved in empirical studies, which validates the methodology proposed in this work.
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Affiliation(s)
| | - Raúl Martín Martín
- Institute of Applied Mathematics for Science and Engineering (IMACI), University of Castilla-La Mancha, Toledo, Spain
- * E-mail:
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7
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Hoseini M, Sharifi S, Sazgarnia A. The Influence of Anionic, Cationic Surfactant and AOT/Water/Heptane Reverse Micelle on Photophysical Properties of Crocin: Compare with RPMI Effect. J Fluoresc 2020; 30:665-677. [PMID: 32338327 DOI: 10.1007/s10895-020-02525-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 01/07/2020] [Accepted: 03/09/2020] [Indexed: 12/27/2022]
Abstract
Encapsulation of crocin (CN), having large nonlinear optical (NLO) properties, can be utilized in studies of photodynamic therapy (PDT). For this purpose, photo-physical and NLO properties of CN encapsulation with and without cell culture medium (CCM) were investigated. As well, nonlinear absorption (NLA) coefficient and nonlinear refractive (NLR) indices were found to be 10-7 (cm W-1) and 10-12 (cm2 W-1); respectively. The results revealed that NLO properties of CN had changed through its dipole moment. Reflecting on the theory of Bilot and Kawski, it was evidenced that the dipole moment of CN could change with a nano-droplet size. Furthermore, it was demonstrated that RPMI-1640 as a growth medium had failed to change NLO properties of CN encapsulated in nano-droplet. Accordingly, the encapsulated CN in nano-droplet in the form of a photosensitizer (PS) was suggested as a good candidate to examine PDT under in-vitro conditions.
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Affiliation(s)
- Mehdi Hoseini
- Department of Medical Physics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
| | - Soheil Sharifi
- Department of Physics, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
| | - Ameneh Sazgarnia
- Department of Medical Physics, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
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8
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Api AM, Belsito D, Botelho D, Bruze M, Burton GA, Buschmann J, Dagli ML, Date M, Dekant W, Deodhar C, Francis M, Fryer AD, Jones L, Joshi K, La Cava S, Lapczynski A, Liebler DC, O'Brien D, Patel A, Penning TM, Ritacco G, Romine J, Sadekar N, Salvito D, Schultz TW, Sipes IG, Sullivan G, Thakkar Y, Tokura Y, Tsang S. RIFM fragrance ingredient safety assessment, 2-propyl heptanenitrile, CAS Registry Number 208041-98-9. Food Chem Toxicol 2020; 138 Suppl 1:111198. [PMID: 32081731 DOI: 10.1016/j.fct.2020.111198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/17/2020] [Accepted: 02/12/2020] [Indexed: 11/18/2022]
Affiliation(s)
- A M Api
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D Belsito
- Member RIFM Expert Panel, Columbia University Medical Center, Department of Dermatology, 161 Fort Washington Ave., New York, NY, 10032, USA
| | - D Botelho
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - M Bruze
- Member RIFM Expert Panel, Malmo University Hospital, Department of Occupational & Environmental Dermatology, Sodra Forstadsgatan 101, Entrance 47, Malmo, SE-20502, Sweden
| | - G A Burton
- Member RIFM Expert Panel, School of Natural Resources & Environment, University of Michigan, Dana Building G110, 440 Church St., Ann Arbor, MI, 58109, USA
| | - J Buschmann
- Member RIFM Expert Panel, Fraunhofer Institute for Toxicology and Experimental Medicine, Nikolai-Fuchs-Strasse 1, 30625, Hannover, Germany
| | - M L Dagli
- Member RIFM Expert Panel, University of Sao Paulo, School of Veterinary Medicine and Animal Science, Department of Pathology, Av. Prof. dr. Orlando Marques de Paiva, 87, Sao Paulo, CEP, 05508-900, Brazil
| | - M Date
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - W Dekant
- Member RIFM Expert Panel, University of Wuerzburg, Department of Toxicology, Versbacher Str. 9, 97078, Würzburg, Germany
| | - C Deodhar
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - M Francis
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - A D Fryer
- Member RIFM Expert Panel, Oregon Health Science University, 3181 SW Sam Jackson Park Rd., Portland, OR, 97239, USA
| | - L Jones
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - K Joshi
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - S La Cava
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - A Lapczynski
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D C Liebler
- Member RIFM Expert Panel, Vanderbilt University School of Medicine, Department of Biochemistry, Center in Molecular Toxicology, 638 Robinson Research Building, 2200 Pierce Avenue, Nashville, TN, 37232-0146, USA
| | - D O'Brien
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - A Patel
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - T M Penning
- Member of RIFM Expert Panel, University of Pennsylvania, Perelman School of Medicine, Center of Excellence in Environmental Toxicology, 1316 Biomedical Research Building (BRB) II/III, 421 Curie Boulevard, Philadelphia, PA, 19104-3083, USA
| | - G Ritacco
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - J Romine
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - N Sadekar
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - D Salvito
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - T W Schultz
- Member RIFM Expert Panel, The University of Tennessee, College of Veterinary Medicine, Department of Comparative Medicine, 2407 River Dr., Knoxville, TN 37996- 4500, USA
| | - I G Sipes
- Member RIFM Expert Panel, Department of Pharmacology, University of Arizona, College of Medicine, 1501 North Campbell Avenue, P.O. Box 245050, Tucson, AZ, 85724-5050, USA
| | - G Sullivan
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA.
| | - Y Thakkar
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
| | - Y Tokura
- Member RIFM Expert Panel, The Journal of Dermatological Science (JDS), Editor-in-Chief, Professor and Chairman, Department of Dermatology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, 431-3192, Japan
| | - S Tsang
- Research Institute for Fragrance Materials, Inc., 50 Tice Boulevard, Woodcliff Lake, NJ, 07677, USA
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Tănase CI, Drăghici C, Hanganu A, Pintilie L, Maganu M, Volobueva A, Sinegubova E, Zarubaev VV, Neyts J, Jochmans D, Slita AV. New HSV-1 Anti-Viral 1'-Homocarbocyclic Nucleoside Analogs with an Optically Active Substituted Bicyclo[2.2.1]Heptane Fragment as a Glycoside Moiety. Molecules 2019; 24:molecules24132446. [PMID: 31277334 PMCID: PMC6651170 DOI: 10.3390/molecules24132446] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 06/28/2019] [Accepted: 06/30/2019] [Indexed: 02/05/2023] Open
Abstract
New 1′-homocarbanucleoside analogs with an optically active substituted bicyclo[2.2.1]heptane skeleton as sugar moiety were synthesized. The pyrimidine analogs with uracil, 5-fluorouracil, thymine and cytosine and key intermediate with 6-chloropurine (5) as nucleobases were synthesized by a selective Mitsunobu reaction on the primary hydroxymethyl group in the presence of 5-endo-hydroxyl group. Adenine and 6-substituted adenine homonucleosides were obtained by the substitution of the 6-chlorine atom of the key intermediate 5 with ammonia and selected amines, and 6-methoxy- and 6-ethoxy substituted purine homonucleosides by reaction with the corresponding alkoxides. No derivatives appeared active against entero, yellow fever, chikungunya, and adeno type 1viruses. Two compounds (6j and 6d) had lower IC50 (15 ± 2 and 21 ± 4 µM) and compound 6f had an identical value of IC50 (28 ± 4 µM) to that of acyclovir, suggesting that the bicyclo[2.2.1]heptane skeleton could be further studied to find a candidate for sugar moiety of the nucleosides.
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Affiliation(s)
- Constantin I Tănase
- National Institute for Chemical-Pharmaceutical Research and Development, Department of bioactive substances and pharmaceutical technologies, 112 Vitan Av., 031299 Bucharest-3, Romania.
| | - Constantin Drăghici
- Organic Chemistry Center "C.D.Nenitescu", Spectroscopy Laboratory, 202 B Splaiul Independentei, 060023 Bucharest, Romania
| | - Anamaria Hanganu
- Organic Chemistry Center "C.D.Nenitescu", Spectroscopy Laboratory, 202 B Splaiul Independentei, 060023 Bucharest, Romania
| | - Lucia Pintilie
- National Institute for Chemical-Pharmaceutical Research and Development, Department of bioactive substances and pharmaceutical technologies, 112 Vitan Av., 031299 Bucharest-3, Romania
| | - Maria Maganu
- Organic Chemistry Center "C.D.Nenitescu", Spectroscopy Laboratory, 202 B Splaiul Independentei, 060023 Bucharest, Romania
| | - Alexandrina Volobueva
- Department of Virology, Pasteur Institute of Epidemiology and Microbiology, 197101 St. Petersburg, Russia
| | - Ekaterina Sinegubova
- Department of Virology, Pasteur Institute of Epidemiology and Microbiology, 197101 St. Petersburg, Russia
| | - Vladimir V Zarubaev
- Department of Virology, Pasteur Institute of Epidemiology and Microbiology, 197101 St. Petersburg, Russia
| | - Johan Neyts
- KU Leuven Department of Micobiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, Herestraat 49, BE-3000 Leuven, Belgium
| | - Dirk Jochmans
- KU Leuven Department of Micobiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, Herestraat 49, BE-3000 Leuven, Belgium
| | - Alexander V Slita
- KU Leuven Department of Micobiology, Immunology and Transplantation, Rega Institute, Laboratory of Virology and Chemotherapy, Herestraat 49, BE-3000 Leuven, Belgium
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10
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Imam S, Prathibha R, Dar P, Almotah K, Al-Khudhair A, Hasan SAM, Salim N, Jilani TN, Mirmira RG, Jaume JC. eIF5A inhibition influences T cell dynamics in the pancreatic microenvironment of the humanized mouse model of Type 1 Diabetes. Sci Rep 2019; 9:1533. [PMID: 30733517 PMCID: PMC6367423 DOI: 10.1038/s41598-018-38341-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/17/2018] [Indexed: 12/14/2022] Open
Abstract
We have developed a transgenic mouse model of Type 1 Diabetes (T1D) in which human GAD65 is expressed in pancreatic β-cells, and human MHC-II is expressed on antigen presenting cells. Induced GAD65 antigen presentation activates T-cells, which initiates the downstream events leading to diabetes. In our humanized mice, we have shown downregulation of eukaryotic translation initiation factor 5 A (elF5A), expressed only in actively dividing mammalian cells. In-vivo inhibition of elF5A hypusination by deoxyhypusine synthase (DHS) inhibitor "GC7" was studied; DHS inhibitor alters the pathophysiology in our mouse model by catalyzing the crucial hypusination and the rate-limiting step of elF5A activation. In our mouse model, we have shown that inhibition of eIF5A resets the pro-inflammatory bias in the pancreatic microenvironment. There was: (a) reduction of Th1/Th17 response, (b) an increase in Treg numbers, (c) debase in IL17 and IL21 cytokines levels in serum, (d) lowering of anti-GAD65 antibodies, and (e) ablation of the ER stress that improved functionality of the β-cells, but minimal effect on the cytotoxic CD8 T-cell (CTL) mediated response. Conclusively, immune modulation, in the case of T1D, may help to manipulate inflammatory responses, decreasing disease severity, and may help manage T1D in early stages of disease. Our study also demonstrates that without manipulating the CTLs mediated response extensively, it is difficult to treat T1D.
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Affiliation(s)
- Shahnawaz Imam
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
| | - R Prathibha
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Pervaiz Dar
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Faculty of Veterinary Sciences and Animal Husbandry, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir (SKUAST-K), Shuhama, Srinagar, 190006, Jammu and Kashmir, India
| | - Khalil Almotah
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Ahmed Al-Khudhair
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Syed Abdul-Moiz Hasan
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Nancy Salim
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Talha Naser Jilani
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA
| | - Raghavendra G Mirmira
- Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Juan Carlos Jaume
- Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
- Center for Diabetes and Endocrine Research (CeDER), Department of Medicine, College of Medicine and Life Sciences, University of Toledo, Toledo, OH, USA.
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11
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Abstract
This comprehensive review of filbertone, a principal flavor compound of hazelnut, evaluates the current state of the art of all relevant aspects of the title molecule: its occurrence and properties, laboratory preparation and bulk synthesis, analytical issues regarding stereochemistry and purity, sensory evaluation, and practical uses. Comparisons are made between different synthetic approaches, and a critical assessment of various applications is presented.
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Affiliation(s)
- Eva Puchl'ová
- Axxence Slovakia Ltd. , Mickiewiczova 9 , SK-811 07 Bratislava , Slovakia
| | - Peter Szolcsányi
- Department of Organic Chemistry , Slovak University of Technology , Radlinského 9 , SK-812 37 Bratislava , Slovakia
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12
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Zereshki S, Daraei P, Shokri A. Application of edible paraffin oil for cationic dye removal from water using emulsion liquid membrane. J Hazard Mater 2018; 356:1-8. [PMID: 29800620 DOI: 10.1016/j.jhazmat.2018.05.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [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: 10/20/2017] [Revised: 05/04/2018] [Accepted: 05/17/2018] [Indexed: 05/12/2023]
Abstract
Using an emulsion liquid membrane based on edible oils is investigated for removing cationic dyes from aqueous solutions. There is a great potential for using edible oils in food industry extraction processes. The parameters affecting the stability of the emulsion and the extraction rate were studied. These parameters were the emulsification time, the stirring speed, the surfactant concentration, the internal phase concentration, the feed phase concentration, the volume ratio of internal phase to organic phase and the treat ratio. In order to stabilize the emulsion without using a carrier, edible paraffin oil and heptane are used at an 80:20 ratio. The optimum conditions for the extraction of methylene blue (MB), crystal violet and methyl violet (CV and MV) cationic dyes using edible paraffin oil as an environment friendly solvent are represented. A removal percentage of 95% was achieved for a mixture of dyes. The optimum concentration of sodium hydroxide in the internal phase, which results a stabile emulsion with a high stripping efficiency of 96%, was 0.04 M. An excellent membrane recovery was observed and the extraction of dyes did not decrease up to seven run cycles.
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Affiliation(s)
- Sina Zereshki
- Department of Chemical Engineering, Kermanshah University of Technology, 6715685420 Kermanshah, Iran.
| | - Parisa Daraei
- Department of Chemical Engineering, Kermanshah University of Technology, 6715685420 Kermanshah, Iran
| | - Amin Shokri
- Department of Chemical Engineering, Kermanshah University of Technology, 6715685420 Kermanshah, Iran
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13
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Crosley DR, Araps CJ, Doyle-Eisele M, McDonald JD. Gas-phase photolytic production of hydroxyl radicals in an ultraviolet purifier for air and surfaces. J Air Waste Manag Assoc 2017; 67:231-240. [PMID: 27629801 DOI: 10.1080/10962247.2016.1229236] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/14/2016] [Accepted: 08/08/2016] [Indexed: 06/06/2023]
Abstract
UNLABELLED We have measured the concentration of hydroxyl radicals (OH) produced in the gas phase by a commercially available purifier for air and surfaces, using the time rate of decay of n-heptane added to an environmental chamber. The hydroxyl generator, an Odorox® BOSS™ model, produces the OH through 185-nm photolysis of ambient water vapor. The steady-state concentration of OH produced in the 120 m3 chamber is, with 2σ error bars, (3.25 ± 0.80) × 106 cm-3. The properties of the hydroxyl generator, in particular the output of the ultraviolet lamps and the air throughput, together with an estimation of the water concentration, were used to predict the amount of OH produced by the device, with no fitted parameters. To relate this calculation to a steady-state concentration, we must estimate the OH loss rate within the chamber owing to reaction with the n-heptane and the 7 ppb of background hydrocarbons that are present. The result is a predicted steady-state concentration in excellent agreement with the measured value. This shows we understand well the processes occurring in the gas phase during operation of this hydroxyl radical purifier. IMPLICATIONS Hydroxyl radical air purifiers are used for cleaning both gaseous contaminants, such as volatile organic compounds (VOCs) or hazardous gases, and biological pathogens, both airborne and on surfaces. This is the first chemical kinetic study of such a purifier that creates gas-phase OH by ultraviolet light photolysis of H2O. It shows that the amount of hydroxyls produced agrees well with nonparameterized calculations using the purifier lamp output and device airflow. These results can be used for designing appropriate remediation strategies.
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Affiliation(s)
- David R Crosley
- a Private consultant to HGI Industries (Boynton Beach, Florida) , Palo Alto , CA , USA
| | | | | | - Jacob D McDonald
- c Lovelace Respiratory Research Institute , Albuquerque , NM , USA
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14
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Zhang TT, Lu CL, Jiang JG. Neuroprotective and Anti-Inflammatory Effects of Diphenylheptanes from the Fruits of Amomum tsaoko, a Chinese Spice. Plant Foods Hum Nutr 2016; 71:450-453. [PMID: 27452308 DOI: 10.1007/s11130-016-0570-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [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: 05/14/2023]
Abstract
Two novel diphenylheptanes, 2,3- dihydro-2 - (4' - hydroxy-phenylethyl) - 6 - [(3″,4″ - dihydroxy-5" - methoxy) phenyl] -4 - pyrone (CG-A) and 4 - dihydro-2 - (4' - hydroxy-phenylmethyl) -6 - [(3",4″ - dihydroxy-5″ - methoxyphenyl) methylene]-pyran-3, 5 - dione (CG-B), were isolated from the dried fruits of Amomum tsaoko, a commercially important spice. This study was designed to investigate their protective effects against H2O2-induced nerve injury, using PC-12 cells to determine the cell cytotoxicity and cell viability. The inhibitory effect on (nitric oxide) NO production was also determined in (lipopolysaccharide) LPS-stimulated macrophage RAW 264.7 cells. The results showed that CG-A and CG-B displayed significant neuroprotective effect and exhibited anti-inflammatory activity in a dose-dependent manner. These findings suggest that CG-A and CG-B are very important nutritional ingredients responsible for the neuroprotective and anti-inflammatory health benefits of A. tsaoko.
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Affiliation(s)
- Tian-Tian Zhang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China
| | - Chuan-Li Lu
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China
- Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Mengla, Yunnan, 666303, China
| | - Jian-Guo Jiang
- School of Food Science and Engineering, South China University of Technology, Guangzhou, 510640, China.
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15
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Vuong F, Chauveau R, Grevillot G, Marsteau S, Silvente E, Vallieres C. Predicting the lifetime of organic vapor cartridges exposed to volatile organic compound mixtures using a partial differential equations model. J Occup Environ Hyg 2016; 13:675-689. [PMID: 27028086 DOI: 10.1080/15459624.2016.1166368] [Citation(s) in RCA: 2] [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] [Indexed: 06/05/2023]
Abstract
In this study, equilibria, breakthrough curves, and breakthrough times were predicted for three binary mixtures of four volatile organic compounds (VOCs) using a model based on partial differential equations of dynamic adsorption coupling a mass balance, a simple Linear Driving Force (LDF) hypothesis to describe the kinetics, and the well-known Extended-Langmuir (EL) equilibrium model. The model aims to predict with a limited complexity, the BTCs of respirator cartridges exposed to binary vapor mixtures from equilibria and kinetics data obtained from single component. In the model, multicomponent mass transfer was simplified to use only single dynamic adsorption data. The EL expression used in this study predicted equilibria with relatively good accuracy for acetone/ethanol and ethanol/cyclohexane mixtures, but the prediction of cyclohexane uptake when mixed with heptane is less satisfactory. The BTCs given by the model were compared to experimental BTCs to determine the accuracy of the model and the impact of the approximation on mass transfer coefficients. From BTCs, breakthrough times at 10% of the exposure concentration t10% were determined. All t10% were predicted within 20% of the experimental values, and 63% of the breakthrough times were predicted within a 10% error. This study demonstrated that a simple mass balance combined with kinetic approximations is sufficient to predict lifetime for respirator cartridges exposed to VOC mixtures. It also showed that a commonly adopted approach to describe multicomponent adsorption based on volatility of VOC rather than adsorption equilibrium greatly overestimated the breakthrough times.
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Affiliation(s)
- François Vuong
- a Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine , Nancy , France
- b Laboratoire de Filtration et d'Adsorption-INRS , Nancy , France
| | - Romain Chauveau
- a Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine , Nancy , France
- b Laboratoire de Filtration et d'Adsorption-INRS , Nancy , France
| | - Georges Grevillot
- a Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine , Nancy , France
| | | | - Eric Silvente
- b Laboratoire de Filtration et d'Adsorption-INRS , Nancy , France
| | - Cécile Vallieres
- a Laboratoire Réactions et Génie des Procédés, CNRS, Université de Lorraine , Nancy , France
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16
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Keller N, Nargang TM, Runck M, Kotz F, Striegel A, Sachsenheimer K, Klemm D, Länge K, Worgull M, Richter C, Helmer D, Rapp BE. Tacky cyclic olefin copolymer: a biocompatible bonding technique for the fabrication of microfluidic channels in COC. Lab Chip 2016; 16:1561-4. [PMID: 27040493 DOI: 10.1039/c5lc01498k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Cyclic olefin copolymer (COC) is widely used in microfluidics due to its UV-transparency, its biocompatibility and high chemical resistance. Here we present a fast and cost-effective solvent bonding technique, which allows for the efficient bonding of protein-patterned COC structures. The bonding process is carried out at room temperature and takes less than three minutes. Enzyme activity is retained upon bonding and microstructure deformation does not occur.
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Affiliation(s)
- Nico Keller
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Tobias M Nargang
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Matthias Runck
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Frederik Kotz
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Andreas Striegel
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Kai Sachsenheimer
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Denis Klemm
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Kerstin Länge
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Matthias Worgull
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Christiane Richter
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Dorothea Helmer
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
| | - Bastian E Rapp
- Karlsruhe Institute of Technology (KIT), Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
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17
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Rayne S, Forest K. Performance of the major semiempirical, ab initio, and DFT methods for isomerization enthalpies of linear to branched heptanes. J Environ Sci Health A Tox Hazard Subst Environ Eng 2016; 51:583-587. [PMID: 26979512 DOI: 10.1080/10934529.2016.1141626] [Citation(s) in RCA: 2] [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] [Indexed: 06/05/2023]
Abstract
The gas phase standard state (298.15 K, 1 atm) isomerization enthalpy (Δ(isom)H°(g)) prediction performance of the major semiempirical, ab initio, and density functional levels of theory for environmentally relevant transformations was investigated using the linear to branched heptanes as a representative case study. The M062X density functional, MP2 (and higher) levels of Moller-Plesset perturbation theory, and the CBS and Gaussian-n composite methods are well suited for investigating the thermodynamic properties of environmentally interesting isomerizations, although the M062X functional may not be appropriate for all systems. Where large molecular systems prohibit the use of higher levels of theory, the PM6 and PDDG semiempirical methods may offer an appropriate computational cost-accuracy compromise.
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Affiliation(s)
- Sierra Rayne
- a Chemologica Research , Moose Jaw , Saskatchewan , Canada
| | - Kaya Forest
- b Department of Environmental Engineering Technology , Saskatchewan Polytechnic , Moose Jaw , Saskatchewan , Canada
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18
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Julien M, Nun P, Robins RJ, Remaud GS, Parinet J, Höhener P. Insights into Mechanistic Models for Evaporation of Organic Liquids in the Environment Obtained by Position-Specific Carbon Isotope Analysis. Environ Sci Technol 2015; 49:12782-8. [PMID: 26443423 DOI: 10.1021/acs.est.5b03280] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Position-specific isotope effects (PSIEs) have been measured by isotope ratio monitoring (13)C nuclear magnetic resonance spectrometry during the evaporation of 10 liquids of different polarities under 4 evaporation modes (passive evaporation, air-vented evaporation, low pressure evaporation, distillation). The observed effects are used to assess the validity of the Craig-Gordon isotope model for organic liquids. For seven liquids the overall isotope effect (IE) includes a vapor-liquid contribution that is strongly position-specific in polar compounds but less so in apolar compounds and a diffusive IE that is not position-specific, except in the alcohols, ethanol and propan-1-ol. The diffusive IE is diminished under forced evaporation. The position-specific isotope pattern created by liquid-vapor IEs is manifest in five liquids, which have an air-side limitation for volatilization. For the alcohols, undefined processes in the liquid phase create additional PSIEs. Three other liquids with limitations on the liquid side have a lower, highly position-specific, bulk diffusive IE. It is concluded that evaporation of organic pollutants creates unique position-specific isotope patterns that may be used to assess the progress of remediation or natural attenuation of pollution and that the Craig-Gordon isotope model is valid for the volatilization of nonpolar organic liquids with air-side limitation of the volatilization rate.
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Affiliation(s)
- Maxime Julien
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Pierrick Nun
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Richard J Robins
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Gérald S Remaud
- EBSI Team, CEISAM, University of Nantes-CNRS UMR 6230 , 2 rue de la Houssinière BP 92208, F-44322 Nantes, France
| | - Julien Parinet
- Laboratoire Chimie Environnement, University of Aix-Marseille-CNRS FRE 3416 , place Victor Hugo 3, F-13331 Marseille, France
| | - Patrick Höhener
- Laboratoire Chimie Environnement, University of Aix-Marseille-CNRS FRE 3416 , place Victor Hugo 3, F-13331 Marseille, France
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19
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Skoblin AA, Stovbun SV. Supercoiling as a Physical Process Providing Formation of Macroscopic Anisometric Supramolecular Structures. Bull Exp Biol Med 2015; 159:607-9. [PMID: 26459482 DOI: 10.1007/s10517-015-3025-3] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Indexed: 11/26/2022]
Abstract
Solutions of chiral and achiral trifluoroacetyl amino alcohols (TFAAA) contain anisometric structures with a diameter <1 nm and length ~7 nm. In homochiral solutions and xerogels, chiral TFAAA form strings with a diameter of ~30-100 nm and length more than ~1 μ, and achiral TFAAA condensate into isometric granule with diameter of ~1 μ. We conclude that molecular chirality determines helicity of strings within tens of nanometers or more. Stabilization of supramolecular structure of strings is presumably achieved via their supercoiling.
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Affiliation(s)
- A A Skoblin
- N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
| | - S V Stovbun
- N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
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20
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Bach N, Bølling AK, Brinchmann BC, Totlandsdal AI, Skuland T, Holme JA, Låg M, Schwarze PE, Øvrevik J. Cytokine responses induced by diesel exhaust particles are suppressed by PAR-2 silencing and antioxidant treatment, and driven by polar and non-polar soluble constituents. Toxicol Lett 2015; 238:72-82. [PMID: 26160521 DOI: 10.1016/j.toxlet.2015.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [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: 09/02/2014] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 12/14/2022]
Abstract
Adsorbed soluble organics seem to be the main drivers of inflammatory responses induced by diesel exhaust particles (DEP). The specific compounds contributing to this process and the cellular mechanisms behind DEP-induced inflammation are not well known. We have assessed pro-inflammatory effects of DEP and various soluble DEP fractions, in human bronchial epithelial cells (BEAS-2B). DEP increased the expression of interleukin (IL)-6 and CXCL8. Silencing of the aryl hydrocarbon receptor (AhR) by siRNA or pretreatment with AhR-antagonists did not attenuate DEP-induced IL-6 and CXCL8 responses. However, the halogenated aromatic hydrocarbon (HAH)-selective AhR antagonist CH223191 caused a considerable reduction in DEP-induced CYP1A1 expression indicating that this response may be due to dioxin or dioxin-like constituents in DEP. Knock-down of protease activated receptor (PAR)-2 attenuated IL-6 responses without affecting CXCL8. Antioxidants did not affect IL-6 expression after 4h DEP-exposure and only partly reduced CXCL8 expression. However, after 24h exposure antioxidant treatment partly suppressed IL-6 protein release and completely blocked CXCL8 release. Furthermore, a heptane-soluble (non-polar) extract of DEP induced both IL-6 and CXCL8 release, whereas a PBS-soluble (highly polar) extract induced only IL-6. Thus, pro-inflammatory responses in DEP-exposed epithelial cells appear to be the result of both reactive oxygen species and receptor signaling, mediated through combinatorial effects between both non-polar and polar constituents adhered to the particle surface.
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Affiliation(s)
- Nicolai Bach
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway; Department of Biology, Faculty of Mathematics and Natural Sciences, University of Oslo, Norway
| | - Anette Kocbach Bølling
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Bendik C Brinchmann
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Annike I Totlandsdal
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Tonje Skuland
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Jørn A Holme
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Marit Låg
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Per E Schwarze
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Johan Øvrevik
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway.
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21
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Ruiz N, de Abreu LA, Parizi LF, Kim TK, Mulenga A, Braz GRC, Vaz IDS, Logullo C. Non-Invasive Delivery of dsRNA into De-Waxed Tick Eggs by Electroporation. PLoS One 2015; 10:e0130008. [PMID: 26091260 PMCID: PMC4474930 DOI: 10.1371/journal.pone.0130008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 05/15/2015] [Indexed: 11/18/2022] Open
Abstract
RNA interference-mediated gene silencing was shown to be an efficient tool for validation of targets that may become anti-tick vaccine components. Here, we demonstrate the application of this approach in the validation of components of molecular signaling cascades, such as the Protein Kinase B (AKT)/Glycogen Synthase Kinase (GSK) axis during tick embryogenesis. It was shown that heptane and hypochlorite treatment of tick eggs can remove wax, affecting corium integrity and but not embryo development. Evidence of AKT and GSK dsRNA delivery into de-waxed eggs of via electroporation is provided. Primers designed to amplify part of the dsRNA delivered into the electroporated eggs dsRNA confirmed its entry in eggs. In addition, it was shown that electroporation is able to deliver the fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI). To confirm gene silencing, a second set of primers was designed outside the dsRNA sequence of target gene. In this assay, the suppression of AKT and GSK transcripts (approximately 50% reduction in both genes) was demonstrated in 7-day-old eggs. Interestingly, silencing of GSK in 7-day-old eggs caused 25% reduction in hatching. Additionally, the effect of silencing AKT and GSK on embryo energy metabolism was evaluated. As expected, knockdown of AKT, which down regulates GSK, the suppressor of glycogen synthesis, decreased glycogen content in electroporated eggs. These data demonstrate that electroporation of de-waxed R. microplus eggs could be used for gene silencing in tick embryos, and improve the knowledge about arthropod embryogenesis.
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Affiliation(s)
- Newton Ruiz
- Unidade de Experimentação Animal and Laboratório de Química e Função de Proteínas—Universidade Estadual Norte Fluminense–Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
| | - Leonardo Araujo de Abreu
- Laboratório Integrado de Bioquímica Hatisaburo Masuda—Núcleo em Ecologia e Desenvolvimento Sócio-Ambiental de Macaé (NUPEM/UFRJ), Macaé, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Ilha do Fundão, RJ, Brazil
| | - Luís Fernando Parizi
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Tae Kwon Kim
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, United States of America
| | - Albert Mulenga
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, United States of America
| | - Gloria Regina Cardoso Braz
- Departamento de Bioquímica–Instituto de Química, Universidade Federal do Rio de Janeiro, Ilha do Fundão, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Ilha do Fundão, RJ, Brazil
| | - Itabajara da Silva Vaz
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Ilha do Fundão, RJ, Brazil
| | - Carlos Logullo
- Unidade de Experimentação Animal and Laboratório de Química e Função de Proteínas—Universidade Estadual Norte Fluminense–Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular (INCT-EM), Rio de Janeiro, Ilha do Fundão, RJ, Brazil
- * E-mail:
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Hayes DG, Gomez del Rio JA, Ye R, Urban VS, Pingali SV, O'Neill HM. Effect of protein incorporation on the nanostructure of the bicontinuous microemulsion phase of Winsor-III systems: a small-angle neutron scattering study. Langmuir 2015; 31:1901-1910. [PMID: 25603188 DOI: 10.1021/la504606x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Small-angle neutron scattering (SANS) analysis using the Teubner-Strey model has been employed to evaluate the effect of protein incorporation into the middle, bicontinuous microemulsion (BμE) phase of Winsor-III (WIII) systems formed by an aerosol-OT (AOT)/alkyl ethoxylate mixed surfactant system to understand better the extraction of proteins into and out of BμEs and to study the effect of proteins on a system that serves as a biomimetic analog of cell membranes. Under conditions of high salinity, the incorporation of positively charged proteins cytochrome c, lysozyme, and α-chymotrypsin, near their solubilization limit in the BμEs promoted the release of water and oil from the BμEs, a decrease in the quasi-periodic repeat distance (d), an increase in ordering (a decrease in the amphiphilicity factor, fa) for the surfactant monolayers, and a decrease in the surface area per surfactant headgroup, suggesting that the proteins affected the self-assembly of components in the BμE phase and produced Debye shielding of AOT's sulfonate headgroup. For WIII systems possessing lower salinity, cytochrome c reduced the efficiency of surfactant in the BμE phase, noted by increases in d and fa, suggesting that the enzyme and AOT underwent ion pairing. The results of this study demonstrate the importance of ionic strength to modulate protein-surfactant interactions, which in turn will control the release of proteins encapsulated in the BμEs, relevant to WIII-based protein extraction and controlled release from BμE delivery systems, and demonstrate the utility of BμEs as a model system to understand the effect of proteins on biomembranes.
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Affiliation(s)
- Douglas G Hayes
- Department of Biosystems Engineering and Soil Science, University of Tennessee , Knoxville, Tennessee 37996-4531, United States
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23
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Ocola EJ, Medders C, Cooke JM, Laane J. Vibrational spectra, theoretical calculations, and structure of 4-silaspiro(3,3)heptane. Spectrochim Acta A Mol Biomol Spectrosc 2014; 130:397-401. [PMID: 24810025 DOI: 10.1016/j.saa.2014.03.131] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 02/07/2014] [Revised: 03/26/2014] [Accepted: 03/29/2014] [Indexed: 06/03/2023]
Abstract
Theoretical computations have been carried out for 4-silaspiro(3,3)heptane (SSH) in order to calculate its structure and vibrational spectra. SSH was found to have two puckered four-membered rings with dihedral angles of 34.2° and a tilt angle of 9.4° between the two rings. The puckering and tilting reduce the D2d symmetry to C2. Nonetheless, the vibrational assignments can be done quite well on the basis of D2d symmetry. This is confirmed by the fact that all but the lowest E vibrations show insignificant splitting into A and B modes of C2 symmetry. However, the observed splittings of the lowest frequency modes do confirm the lower conformational symmetry. The calculated infrared and Raman spectra were compared to the experimental spectra collected for the vapor, liquid, and solid states, and the agreement is excellent.
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Affiliation(s)
- Esther J Ocola
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, United States
| | - Cross Medders
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, United States
| | - Joel M Cooke
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, United States
| | - Jaan Laane
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, United States.
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Hussain R, Vogt SJ, Honari A, Hollingsworth KG, Sederman AJ, Mitchell J, Johns ML. Interfacial tension measurements using MRI drop shape analysis. Langmuir 2014; 30:1566-1572. [PMID: 24471906 DOI: 10.1021/la404635x] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Accurate interfacial tension data for fluid systems such as hydrocarbons and water is essential to many applications such as reservoir oil and gas recovery predictions. Conventional interfacial tension measurement techniques typically use optical images to analyze droplet shapes but require that the continuous-phase fluid be optically transparent and that the fluids are not refractive index matched. Magnetic resonance images obtain contrast between fluids using other mechanisms such as magnetic relaxation weighting, so systems that are impossible to measure with optical methods may be analyzed. In this article, we present high-field (9.4 T) MRI images of various droplets analyzed with axisymmetric drop shape analysis. The resultant interfacial tension data show good agreement with literature data. The method is subsequently demonstrated using both opaque continuous phases and refractive-index-matched fluids. We conclude with a brief consideration of the potential to extrapolate the methodology to lower magnetic fields (0.3 T), featuring more accessible hardware; although droplet imaging is possible, resolution and stability do not currently permit accurate interfacial tension measurements.
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Affiliation(s)
- R Hussain
- Department of Chemical Engineering and Biotechnology, University of Cambridge , Pembroke Street, Cambridge CB2 3RA, United Kingdom
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25
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Cai DF, Huang WQ, Wang DL, Zhang L, Yang G. [Study on adsorption properties of organic vapor on activated carbons]. Huan Jing Ke Xue 2013; 34:4694-4700. [PMID: 24640910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Adsorption technology is widely used in oil vapor recovery, and adsorbents have decisive effect on separation. Three kinds of activated carbon (AC) were chosen to study their adsorption properties and adsorption energy, where n-hexane and n-heptane acted as adsorbate and adsorption experiments were conducted at 293.15 K. At the same time, regression formula of Logistic model was used to fit the throughout curves of active carbons. The results showed that: surface area and pore volume of activated carbon were the main factors affecting its adsorption properties; the adsorption behavior of n-hexane and n-heptane were corresponding to Langmuir adsorption isotherm model; adsorption energy of these three kinds of activated carbon became greater with increasing specific surface area. Fitting curve of Logistic model had high similarity with the experimental results, which could be used in the prediction of breakthrough curves of activated carbons.
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Scott G, Roy S, Abul-Haija YM, Fleming S, Bai S, Ulijn RV. Pickering stabilized peptide gel particles as tunable microenvironments for biocatalysis. Langmuir 2013; 29:14321-14327. [PMID: 24144273 DOI: 10.1021/la403448s] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We demonstrate the preparation of peptide gel microparticles that are emulsified and stabilized by SiO2 nanoparticles. The gels are composed of aromatic peptide amphiphiles 9-fluorenylmethoxycarbonyldiphenylalanine (Fmoc-FF) coassembled with Fmoc-amino acids with different functional groups (S: serine; D: aspartic acid; K: lysine; and Y: tyrosine). The gel phase provides a highly hydrated matrix, and peptide self-assembly endows the matrix with tunable chemical environments which may be exploited to support and stabilize proteins. The use of Pickering emulsion to stabilize these gel particles is advantageous through avoidance of surfactants that may denature proteins. The performance of enzyme lipase B immobilized in pickering/gel microparticles with different chemical functionalities is investigated by studying transesterification in heptane. We show that the use of Pickering particles enhances the performance of the enzyme, which is further improved in gel-phase systems, with hydrophilic environment provided by Fmoc-FF/S giving rise to the best catalytic performance. The combination of a tunable chemical environment in gel phase and Pickering stabilization described here is expected to prove useful for areas where proteins are to be exploited in technological contexts such as biocatalysis and also in other areas where protein performance and activity are important, such as biosensors and bioinspired solar fuel devices.
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Affiliation(s)
- Gary Scott
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K
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27
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Björk EM, Söderlind F, Odén M. Tuning the shape of mesoporous silica particles by alterations in parameter space: from rods to platelets. Langmuir 2013; 29:13551-13561. [PMID: 24102575 DOI: 10.1021/la403201v] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The knowledge of how to control the pore size and morphology of separated mesoporous silica particles is crucial for optimizing their performance in applications, such as molecular sieves and drug delivery systems. In this work, we have systematically studied the effects of various synthesis parameters to gain a deeper understanding of how particle morphologies can be altered. It was found that the morphology for isolated particles of SBA-15 type, with unusually short and wide pores, could be altered from rods to platelets by variations in the NH4F concentration. The pore length is nearly constant (~300 nm) for the different morphologies, but the particle width is increasing from 200 nm to >3 μm when decreasing the amount of NH4F, and the pore size can be tuned between 10 and 13 nm. Furthermore, other synthesis parameters such as heptane concentration, pH, silica precursor, and additions of ions have also been studied. The trend regarding particle width is independent of heptane concentration, at the same time as heptane increases the particle length up to a plateau value of ~500 nm. In all, parameters controlling particle width, length, and pore size have been separated in order to evaluate their function in the particle formation. Additionally, it was found that the formation time of the particles is strongly affected by the fluoride ion concentration, and a mechanism for particle formation for this system, where micelles transform from a foam, to multilamellar vesicles, and finally to cylindrical micelles, is suggested.
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Affiliation(s)
- Emma M Björk
- Nanostructured Materials, Department of Physics, Chemistry and Biology, Linköping University , Linköping SE-58183, Sweden
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28
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Kielbus M, Skalicka-Wozniak K, Grabarska A, Jeleniewicz W, Dmoszynska-Graniczka M, Marston A, Polberg K, Gawda P, Klatka J, Stepulak A. 7-substituted coumarins inhibit proliferation and migration of laryngeal cancer cells in vitro. Anticancer Res 2013; 33:4347-4356. [PMID: 24123002] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Coumarins are a large group of naturally-occurring compounds with a wide range of biological properties, including anticancer activity. 7-Substituted coumarins (umbelliferone, scoparone, and herniarin) were analyzed for their potential anticancer activity against laryngeal cancer cells (LCC). MATERIALS AND METHODS High-performance counter-current chromatography was applied for successful separation of umbelliferone from fruits of Heracleum leskowii. A two-phase solvent system composed of n-heptane-methanol-ethyl acetate-water (1:2:1:2, v/v/v) was successfully used. Cell proliferation was assessed after 48-72 h by means of MTT test, and tumor cell motility by a wound assay model. Measurement of cell death was estimated using enzyme-linked immunosorbent assay (ELISA), and cell-cycle analysis was performed by flow cytometry. Extracellular signal-regulated kinases-1/2 (ERK1/2) and AKT kinase activation status were analyzed by western blotting. RESULTS Umbelliferone, scoparone, and, to a lesser extent, herniarin reduced viability and migration of RK33 LCC in a dose-dependent manner. Scoparone and herniarin were found to induce apoptosis of LCC. None of the tested compounds influenced the ERK1/2 and AKT kinase activity, nor significantly affected cell-cycle progression in the LCC line studied. CONCLUSION Our findings suggest the therapeutic potential of 7-substituted coumarins in the treatment of laryngeal cancer.
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Affiliation(s)
- Michal Kielbus
- Department of Biochemistry and Molecular Biology, Medical University of Lublin, Chodźki 1, 20-093 Lublin, Poland.
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Hamdan A, Noel C, Kosior F, Henrion G, Belmonte T. Dynamics of bubbles created by plasma in heptane for micro-gap conditions. J Acoust Soc Am 2013; 134:991-1000. [PMID: 23927098 DOI: 10.1121/1.4812255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The determination of the initial pressure at the bubble wall created by a discharge in heptane for micro-gap conditions cannot be determined straightforwardly by modeling the time-oscillations of the bubble. The resolution of the Gilmore equation gives the same solutions beyond 1 μs typically for various sets of initial parameters, making impossible the determination of the initial pressure at the bubble wall. Furthermore, the very first instant of the bubble formation is not easily accessible at very short time scales because of the plasma emission. Since the pressure waves propagate in the liquid, it is much easier to gain information on the first instants of the bubble formation by studying the pressure field far from the emission source. Then, it is possible to deduce by modeling what happened at the beginning of the emission of the pressure waves. The proposed solution consists in looking at the oscillations affecting another bubble located at least twice farther from the interelectrode gap than the maximum radius reached by the discharge bubble. The initial plasma pressure can be determined by this method.
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Affiliation(s)
- A Hamdan
- Institut Jean Lamour, Université de Lorraine, Parc de Saurupt, CS 14234, UMR CNRS 7198, Nancy, F-54042, France
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Leclercq L, Company R, Mühlbauer A, Mouret A, Aubry JM, Nardello-Rataj V. Versatile eco-friendly pickering emulsions based on substrate/native cyclodextrin complexes: a winning approach for solvent-free oxidations. ChemSusChem 2013; 6:1533-1540. [PMID: 23794395 DOI: 10.1002/cssc.201300081] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [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: 01/24/2013] [Indexed: 06/02/2023]
Abstract
Solvent-less Pickering emulsions were developed and applied to catalytic oxidation. These systems are stabilized by inclusion complexes between cyclodextrins and substrates, forming a 3D network among the dispersed phase. In the presence of hydrogen peroxide as a green oxidant and [Na]3 [PW12 O40 ] as a catalyst, they provide particularly efficient reaction media for the oxidation of olefins, organosulfurs, and alcohols. The reactions proceed at competitive rates (up to 400 h(-1) ) with straightforward separation of the phases by centrifugation or heating. Moreover, these new eco-friendly systems work at a preparative scale (up to 2.5 M) and are recycled without loss of activity.
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Affiliation(s)
- Loïc Leclercq
- Université Lille 1, EA 4478, Chimie Moléculaire et Formulation, F-59655 Villeneuve d'Ascq Cedexm, France
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Moyano F, Setien E, Silber JJ, Correa NM. Enzymatic hydrolysis of N-benzoyl-L-tyrosine p-nitroanilide by α-chymotrypsin in DMSO-water/AOT/n-heptane reverse micelles. A unique interfacial effect on the enzymatic activity. Langmuir 2013; 29:8245-8254. [PMID: 23734596 DOI: 10.1021/la401103q] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The reverse micelle (RM) media are very good as nanoreactors because they can create a unique microenvironment for carrying out a variety of chemical and biochemical reactions. The aim of the present work is to determine the influence of different water-dimethyl sulfoxide (DMSO) mixtures encapsulated in 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/n-heptane RMs on the enzymatic hydrolysis of N-benzoyl-L-tyrosine p-nitroanilide (Bz-Try-pNA) by α-chymotrypsin (α-CT). The reaction was first studied in homogeneous media at different DMSO-water mixture compositions and in DMSO-water/AOT/n-heptane RMs. The hydrolysis rates of Bz-Try-pNA catalyzed by α-CT were determined by UV-vis spectroscopy. The reaction follows the Michaelis-Menten mechanism and the kinetic parameters: kcat, KM, and kcat/KM were evaluated under different conditions. In this homogeneous media, DMSO plays an important role in the solubilization process of the peptide which is almost insoluble in water, but it has a tremendous impact on the inactivation of α-CT. It is shown that the enzyme dissolved in a 20% molar ratio of the DMSO-water mixture does not present enzymatic activity. Dynamic light scattering has been used to assess the formation of DMSO-water/AOT/heptane RMs at different DMSO compositions. The results also show that there is preferential solvation of the AOT RM interface by water molecules. To test the use of these RMs as nanoreactors, the kinetic parameters for the enzymatic reaction in these systems have been evaluated. The parameters were determined at fixed W(S) {W(S) = ([water] + [DMSO])/[AOT] = 20} at different DMSO-water compositions. The results show that the Michaelis-Menten mechanism is valid for α-CT in all the RM systems studied and that the reaction takes place at the RM interface. Surprisingly, it was observed that the enzyme encapsulated by the RMs show catalytic effects with similar kcat/KM values at any DMSO composition investigated, which evidence that DMSO molecules are localized far from the RM interface.
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Affiliation(s)
- Fernando Moyano
- Departamento de Química, Universidad Nacional de Río Cuarto, Agencia Postal # 3. C.P. X5804BYA Río Cuarto, Argentina
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Hamzaoui M, Renault JH, Nuzillard JM, Reynaud R, Hubert J. Stepwise elution of a three-phase solvent system in centrifugal partition extraction: a new strategy for the fractionation and phytochemical screening of a crude bark extract. Phytochem Anal 2013; 24:367-373. [PMID: 23427023 DOI: 10.1002/pca.2418] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 11/02/2012] [Accepted: 12/07/2012] [Indexed: 06/01/2023]
Abstract
INTRODUCTION Tree bark represents an interesting source of bioactive molecules for the discovery of new pharmaceutical agents. However, the detailed screening of secondary metabolites in crude bark extracts is often hampered by the presence of tannins, which are difficult to separate from other plant constituents. OBJECTIVE In the present study, a new centrifugal partition extraction (CPE) method was developed in order to fractionate a crude bark extract of Anogeissus leiocarpus Guill. & Perr. (Combretaceae). METHODS A three-phase solvent system composed of n-heptane, methyl tert-butyl ether, acetonitrile and water was optimised for the stepwise elution at 20 mL/min of different phytochemical classes according to their hydrophobicity. Onedimensional and two-dimensional NMR analyses of the simplified fractions were then performed in order to characterise potentially interesting metabolites. RESULTS In one step, 5 g of the initial crude extract were efficiently fractionated to yield highly simplified fractions that contained triterpenes, ellagic acid derivatives, flavonoids and phenolic compounds. All undesired compounds, that is, the highly abundant water-soluble tannins (78.8%), were totally removed and each run was rapidly achieved in 90 min on a the multi-gram scale and with low solvent volumes. CONCLUSION Centrifugal partition extraction in the elution mode using a three-phase solvent system can thus be proposed as an efficient and cost-effective alternative for a rapid fractionation of crude bark extracts and for an effective screening of potentially active secondary metabolites.
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Affiliation(s)
- Mahmoud Hamzaoui
- UMR CNRS 7312, Université de Reims Champagne-Ardenne, Bât. 18, Moulin de la Housse, BP 1039 51687 Reims, Cedex 2, France
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Abstract
The photoinduced wettabilities of water, n-hexadecane, dodecane, and n-heptane on a flat TiO2 surface prepared by a sol-gel method-based coating were investigated. An amphiphilic surface produced by UV irradiation exhibited underwater superoleophobicity with an extremely high static oil contact angle (CA) of over 160°. The TiO2 surface almost completely repelled the oil droplet in water. A robust TiO2 surface with no fragile nanomicrostructure was fabricated on a Ti mesh with a pore size of approximately 150 μm. The fabricated mesh was found to be applicable as an oil/water separation filter.
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Affiliation(s)
- Yusuke Sawai
- Department of Material and Energy Science, Graduate School of Environmental and Life Science, Okayama University, Kita-ku, Okayama 700-8530, Japan
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Gallegos MV, Falco LR, Peluso MA, Sambeth JE, Thomas HJ. Recovery of manganese oxides from spent alkaline and zinc-carbon batteries. An application as catalysts for VOCs elimination. Waste Manag 2013; 33:1483-1490. [PMID: 23562448 DOI: 10.1016/j.wasman.2013.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Revised: 02/19/2013] [Accepted: 03/04/2013] [Indexed: 06/02/2023]
Abstract
Manganese, in the form of oxide, was recovered from spent alkaline and zinc-carbon batteries employing a biohydrometallurgy process, using a pilot plant consisting in: an air-lift bioreactor (containing an acid-reducing medium produced by an Acidithiobacillus thiooxidans bacteria immobilized on elemental sulfur); a leaching reactor (were battery powder is mixed with the acid-reducing medium) and a recovery reactor. Two different manganese oxides were recovered from the leachate liquor: one of them by electrolysis (EMO) and the other by a chemical precipitation with KMnO4 solution (CMO). The non-leached solid residue was also studied (RMO). The solids were compared with a MnOx synthesized in our laboratory. The characterization by XRD, FTIR and XPS reveal the presence of Mn2O3 in the EMO and the CMO samples, together with some Mn(4+) cations. In the solid not extracted by acidic leaching (RMO) the main phase detected was Mn3O4. The catalytic performance of the oxides was studied in the complete oxidation of ethanol and heptane. Complete conversion of ethanol occurs at 200°C, while heptane requires more than 400°C. The CMO has the highest oxide selectivity to CO2. The results show that manganese oxides obtained using spent alkaline and zinc-carbon batteries as raw materials, have an interesting performance as catalysts for elimination of VOCs.
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Affiliation(s)
- María V Gallegos
- Pla.Pi.Mu-Planta Piloto Multipropósito, (CICPBA-UNLP) Cno. Centenario y 505, M.B. Gonnet, Buenos Aires, Argentina.
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Born P, Kraus T. Ligand-dominated temperature dependence of agglomeration kinetics and morphology in alkyl-thiol-coated gold nanoparticles. Phys Rev E Stat Nonlin Soft Matter Phys 2013; 87:062313. [PMID: 23848681 DOI: 10.1103/physreve.87.062313] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 04/25/2013] [Indexed: 06/02/2023]
Abstract
The stability of nanoparticle suspensions and the details of their agglomeration depend on the interactions between particles. We study this relationship in gold nanoparticles stabilized with different alkyl thiols in heptane. Temperature-dependent interactions were inferred from small-angle x-ray scattering, agglomeration kinetics from dynamic light scattering, and agglomerate morphologies from transmission electron microscopy. We find that the particles precipitate at temperatures below the melting temperatures of the dry ligands. Agglomerates grow with rates that depend on the temperature: Around precipitation temperature, globular agglomerates form slowly, while at lower temperatures, fibrilar agglomerates form rapidly. All agglomerates contain random dense packings rather than crystalline superlattices. We conclude that ligand-ligand and ligand-solvent interactions of the individual particles dominate suspension stability and agglomeration kinetics. The microscopic packing is dominated by interactions between the ligands of different nanoparticles.
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Affiliation(s)
- Philip Born
- Structure Formation Group, Leibniz Institute for New Materials (INM), Campus D2 2, 66123 Saarbrücken, Germany
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36
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Abstract
Water-heptane/toluene model emulsions were prepared to study emulsion transitional phase inversion by in situ near-infrared spectroscopy (NIR). The first emulsion contained a small amount of ionic surfactant (0.27 wt % of sodium dodecyl sulfate) and n-pentanol as a cosurfactant. In this emulsion, the study was guided by an inversion coordinate route based on a phase behavior study previously performed. The morphology changes were induced by rising aqueous phase salinity in a "steady-state" inversion protocol. The second emulsion contained a nonionic surfactant (ethoxylated nonylphenol) at a concentration of 3 wt %. A continuous temperature change induced two distinct transitional phase inversions: one occurred during the heating of the system and another during the cooling. NIR spectroscopy was able to detect phase inversion in these emulsions due to differences between light scattered/absorbed by water in oil (W/O) and oil in water (O/W) morphologies. It was observed that the two model emulsions exhibit different inversion mechanisms closely related to different quantities of the middle phases formed during the three-phase behavior of Winsor type III.
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Affiliation(s)
- R M Charin
- Programa de Engenharia Química, COPPE, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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37
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Stasi LP, Artusi R, Bovino C, Buzzi B, Canciani L, Caselli G, Colace F, Garofalo P, Giambuzzi S, Larger P, Letari O, Mandelli S, Perugini L, Pucci S, Salvi M, Toro P. Discovery, synthesis, selectivity modulation and DMPK characterization of 5-azaspiro[2.4]heptanes as potent orexin receptor antagonists. Bioorg Med Chem Lett 2013; 23:2653-8. [PMID: 23535328 DOI: 10.1016/j.bmcl.2013.02.093] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 02/17/2013] [Accepted: 02/20/2013] [Indexed: 11/18/2022]
Abstract
Starting from a orexin 1 receptor selective antagonist 4,4-disubstituted piperidine series a novel potent 5-azaspiro[2.4]heptane dual orexin 1 and orexin 2 receptor antagonist class has been discovered. SAR and Pharmacokinetic optimization of this series is herein disclosed. Lead compound 15 exhibits potent activity against orexin 1 and orexin 2 receptors along with low cytochrome P450 inhibition potential, good brain penetration and oral bioavailability in rats.
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Affiliation(s)
- Luigi Piero Stasi
- Rottapharm Madaus, Medicinal Chemistry Department, via Valosa di Sopra 9, 20900 Monza, Italy.
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38
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Kota AK, Li Y, Mabry JM, Tuteja A. Hierarchically structured superoleophobic surfaces with ultralow contact angle hysteresis. Adv Mater 2012; 24:5838-43. [PMID: 22930526 DOI: 10.1002/adma.201202554] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2012] [Revised: 07/29/2012] [Indexed: 05/11/2023]
Abstract
Hierarchically structured, superoleophobic surfaces are demonstrated that display one of the lowest contact angle hysteresis values ever reported - even with extremely low-surface-tension liquids such as n-heptane. Consequently, these surfaces allow, for the first time, even ≈2 μL n-heptane droplets to bounce and roll-off at tilt angles. ≤ 2°.
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Affiliation(s)
- Arun K Kota
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
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39
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Stovbun SV, Skoblin AA, Zanin AM, Mikhailov AI, Tverdislov VA, Bragina EE, Rybin YM, Ageev IM, Shishkin GG. Metric similarity of dynamic commutation processes in situ and in vitro. Bull Exp Biol Med 2012; 153:843-5. [PMID: 23113299 DOI: 10.1007/s10517-012-1840-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The dynamics of string growth was studied in model homochiral solutions of biomimetics, trifluoroacetylated amino alcohols (TFAAA) in heptane, water, and inverted heptane-water emulsion. In heptane and water, a thick (~1 μ in diameter) string had a crown of thin strings on its growing terminal and these thin strings effectively adsorbed dissolved TFAAA. In emulsion, the strings grew inside the water droplets, in which this TFAAA cannot be solved, presumably due to transport of TFAAA molecules from heptane into water in the surface layer surrounding the string. Applications of these phenomena to in vivo cell commutation were discussed.
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Affiliation(s)
- S V Stovbun
- N. N. Semenov Institute of Chemical Physics, the Russian Academy of Sciences, Moscow, Russia.
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40
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Steinbach A, Tautzenberger A, Schaller A, Kalytta-Mewes A, Tränkle S, Ignatius A, Volkmer D. Plasma-enhanced chemical vapor deposition of n-heptane and methyl methacrylate for potential cell alignment applications. ACS Appl Mater Interfaces 2012; 4:5196-5203. [PMID: 22992135 DOI: 10.1021/am301124b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Plasma-enhanced chemical vapor deposited polymers (plasma polymers) are promising candidates for biomaterials applications. In the present study, plasma deposition as a fast and easily scalable method was adapted to deposit coatings from n-heptane and methyl methacrylate monomers onto glass substrates. Linear patterns with line and groove widths between 1.25 and 160 μm were introduced by degrative UV-lithography for cell alignment. Differential interference contrast optical microscopy, profilometry and atomic force microscopy revealed that the patterned surfaces had a smooth, homogeneous appearance and a pattern height of 8 and 45 nm for plasma deposited n-heptane and methyl methacrylate, respectively. UV-lithography increased the oxygen content on the surface drastically as shown by X-ray photoelectron spectroscopy. After immersion in simulated body fluid for 21 days, the pattern was still intact, and the ester groups were also maintained for the most part as shown by infrared spectroscopy. To test the coatings' potential applicability for biomaterial surfaces in a preliminary experiment, we cultured murine preosteoblastic MC3T3-E1 cells on these coatings. Light and electron microscopically, a normal spindle-shaped and aligned cell morphology was observed. At the mRNA level, cells showed no signs of diminished proliferation or elevated expression of apoptosis markers. In conclusion, plasma-enhanced chemical vapor deposited polymers can be patterned with a fast and feasible method and might be suitable materials to guide cell alignment.
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Affiliation(s)
- Annina Steinbach
- Chair of Solid State Chemistry, Institute of Physics, Universitätstrasse 1, 86159 Augsburg, Germany
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41
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McDonald KL, Sharp DJ, Rickoll W. Transmission electron microscopy of thin sections of Drosophila: preparation of embryos using n-heptane and glutaraldehyde. Cold Spring Harb Protoc 2012; 2012:1100-1103. [PMID: 23028066 DOI: 10.1101/pdb.prot068460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This protocol describes the simultaneous permeabilization of Drosophila embryos with n-heptane and initial fixation with glutaraldehyde. Even though the vitelline membrane around the embryo is chemically permeabilized, it must be manually removed to achieve infiltration with embedding resins. Once the embryo is embedded, it can be sectioned for transmission electron microscopy (TEM). This procedure can produce excellent preservation for ultrastructural analysis, and is useful for situations where optimal preservation (e.g., by high-pressure freezing) is not required or is not feasible.
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Voiciuk V, Valincius G, Budvytytė R, Matijoška A, Matulaitienė I, Niaura G. Surface-enhanced Raman spectroscopy for detection of toxic amyloid β oligomers adsorbed on self-assembled monolayers. Spectrochim Acta A Mol Biomol Spectrosc 2012; 95:526-532. [PMID: 22579335 DOI: 10.1016/j.saa.2012.04.043] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 03/23/2012] [Accepted: 04/08/2012] [Indexed: 05/31/2023]
Abstract
Surface-enhanced Raman spectroscopy (SERS) was used to detect different spectral features of small (1-2 nm) and large (5-10 nm) synthetic amyloid Aβ-42 oligomers, exhibiting high and no detectable neurotoxicities, respectively. Adsorption of peptides at self-assembled monolayers (SAM) terminated by methyl and pyridinium groups was employed to differentiate toxic and non-toxic oligomers. Three SAMs were analyzed: hydrophobic heptanethiol (HT) and octadecanethiol (ODT) as well as positively charged N-(6-mercapto)hexylpyridinium (MHP) chloride. SERS study revealed twofold adsorption effect, changes in the monolayer structure and appearance of new bands associated with the adsorbed peptides. A band at 1387 cm(-1), observed as a result of the SAM and Aβ-42 interaction, is tentatively assigned to the peptide symmetric stretching vibration of carboxylate groups, and appears to be the most prominent spectral feature distinguishing toxic oligomers from the non-toxic Aβ-42 forms. This band was identified in the spectra of Aβ-42 adsorption on heptanethiol and MHP monolayers, while no clear perturbations were observed in the case of ODT monolayer.
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Affiliation(s)
- Vladislava Voiciuk
- Institute of Biochemistry, Vilnius University, Mokslininkų 12, LT-08662 Vilnius, Lithuania
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43
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Tran JQ, Ceballos DM, Dills RL, Yost MG, Morgan MS. Transport of a solvent mixture across two glove materials when applied in a paint matrix. Arch Environ Contam Toxicol 2012; 63:169-176. [PMID: 22434453 DOI: 10.1007/s00244-012-9758-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 02/27/2012] [Indexed: 05/31/2023]
Abstract
The transport of mixed paint solvents through natural rubber latex (4 mil) and nitrile rubber (5 mil) gloves was evaluated after spray application of the paint formulation directly on the glove surface. Glove materials and thicknesses were those selected by the majority of spray painters in the local automobile repair industry. A flat panel containing glove specimens mounted in multiple permeation cells permitted evaporation of solvents from the applied paint and incorporated a solid sorbent receiving medium for measuring glove membrane transport. The panel was sprayed in a paint booth to simulate use conditions. Charcoal cloth under the glove adsorbed transported solvents, which were quantified by gas chromatography. For each solvent component, results were expressed as mass transported through the glove relative to the mass applied, per unit area, during 30 min after spray application. The paint formulation contained ketones, acetates, and aromatics. Natural rubber latex allowed 6-10 times the transport of solvents relative to nitrile rubber for all eight solvent components: methyl ethyl ketone, toluene, styrene, ethyl benzene, xylene isomers, and 2-heptanone. m-Xylene showed the largest difference in transport between the two glove materials. This solvent also had the highest transport for each material. The results indicate that nitrile rubber gloves offer somewhat greater chemical resistance to all eight solvents studied compared with natural rubber latex gloves, regardless of the chemical properties of the individual solvent components. However, it must be emphasized that neither of the glove materials, in the thicknesses used in this study, provide adequate protection when exposed by direct spray painting. Simulation of realistic spray conditions may offer a source of useful information on the performance of chemical protective gloves because it accounts for solvent evaporation and the effect of paint polymerization after application on glove transport.
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Affiliation(s)
- Jackelin Q Tran
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, 98195-7234, USA
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44
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Abstract
Photodegradation is seldom considered at the surface of vegetation after crop spraying. Chlorothalonil, a broad-spectrum foliar fungicide with a very widespread use worldwide, was considered. To represent the waxy upper layer of leaves, tests were performed within thin paraffin wax films or in n-heptane. Laser flash photolysis together with steady-state irradiation in n-heptane allowed the determination of the photodegradation mechanisms Chlorothalonil ability to produce singlet oxygen was measured; noteworthy its efficiency is close to 100%. Additionally, chlorothalonil photodegradation mainly proceeds through reductive dechlorination. In these hydrophobic media, a radical mechanism was evidenced. Photochemical tests on wax films under simulated solar light show that formulated chlorothalonil is more reactive than pure chlorothalonil. The field-extrapolated half-life of photolysis on vegetation was estimated to 5.3 days. This value was compared to the half-lives of penetration and volatilization available in the literature. It appears that chlorothalonil dissipation from crops is ruled by both photodegradation and penetration. The relative importance of the two paths probably depends on meteorological factors and on physicochemical characteristics of the crop leaf cuticle.
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Affiliation(s)
- S Monadjemi
- Laboratoire de Photochimie Moléculaire et Macromoléculaire, Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
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45
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Alemán-Vázquez LO, Cano-Domínguez JL, Torres-García E, Villagómez-Ibarra JR. Industrial application of catalytic systems for n-heptane isomerization. Molecules 2011; 16:5916-27. [PMID: 21760573 PMCID: PMC6264159 DOI: 10.3390/molecules16075916] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2011] [Accepted: 07/12/2011] [Indexed: 11/16/2022] Open
Abstract
The ideal gasoline must have a high pump octane number, in the 86 to 94 range, and a low environmental impact. Alkanes, as a family, have much lower photochemical reactivities than aromatics or olefins, but only the highly branched alkanes have adequate octane numbers. The purpose of this work is to examine the possibilities of extending the technological alternative of paraffin isomerization to heavier feedstocks (i.e., n-heptane) using non-conventional catalytic systems which have been previously proposed in the literature: a Pt/sulfated zirconia catalyst and a molybdenum sub-oxide catalyst. Under the experimental conditions at which these catalysts have been evaluated, the molybdenum sub-oxide catalyst maintains a good activity and selectivity to isomerization after 24 h, while the Pt/sulfated zirconia catalyst shows a higher dimethylpentanes/methylhexanes ratio, probably due to a lower operating temperature, but also a high formation of cracking products, and presents signs of deactivation after 8 h. Though much remains to be done, the performance of these catalysts indicates that there are good perspectives for their industrial application in the isomerization of n-heptane and heavier alkanes.
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Affiliation(s)
- Laura Olivia Alemán-Vázquez
- Transformation Processes Program, Mexican Petroleum Institute, Pachuca- Cd Sahagún Road km 7.5, Canacintra Industrial Park, Mineral de la Reforma, Hgo. 42186, Mexico.
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46
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Lu W, Lu Y, Liu F, Shang K, Wang W, Yang Y. Extraction of gold(III) from hydrochloric acid solutions by CTAB/n-heptane/iso-amyl alcohol/Na2SO3 microemulsion. J Hazard Mater 2011; 186:2166-2170. [PMID: 21236565 DOI: 10.1016/j.jhazmat.2010.12.059] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Revised: 12/12/2010] [Accepted: 12/14/2010] [Indexed: 05/30/2023]
Abstract
The extraction of Au(III) from hydrochloric acid solutions by microemulsion was studied. The extraction experiments were carried out using cetyltrimethylammonium bromide (CTAB) as surfactant and iso-amyl alcohol as co-surfactant. Au(III) was found to be extracted into the microemulsion phase due to ion pair formation such as AuCl(4)(-)CTAB(+). The influence of temperature on the extraction of Au(III) has been investigated at temperatures ranging from 288 to 313 K. Temperature was found to decrease the distribution of Au(III). Thermodynamic parameters like enthalpy and entropy of the extraction, calculated by applying Van't Hoff equation, were -36.76 kJ mol(-1) and -84.87 J mol(-1) K(-1), respectively. Furthermore, the influence of the concentrations of hydrogen ion and chloride anion on the extraction efficiency (E%) were verified. Au(III) was extracted quantitatively (E%>99%) and selectively at the whole range of HCl concentrations (0.2-5 M). Recovery of gold from electrical waste and treatment of CTAB wastewater generated from the extraction were also discussed. Thus, the extraction of Au(III) from hydrochloric acid solutions by microemulsion is an effective approach.
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Affiliation(s)
- Wenjuan Lu
- Key Laboratory for Special Functional Aggregated Materials of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
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47
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Wang M, Quist HE, Hansen BJ, Peng Y, Zhang Z, Hawkins AR, Rockwood AL, Austin DE, Lee ML. Performance of a halo ion trap mass analyzer with exit slits for axial ejection. J Am Soc Mass Spectrom 2011; 22:369-378. [PMID: 21472596 DOI: 10.1007/s13361-010-0027-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 10/27/2010] [Accepted: 11/05/2010] [Indexed: 05/30/2023]
Abstract
The halo ion trap (IT) was modified to allow for axial ion ejection through slits machined in the ceramic electrode plates rather than ejecting ions radially to a center hole in the plates. This was done to preserve a more uniform electric field for ion analysis. An in-depth evaluation of the higher-order electric field components in the trap was also performed to improve resolution. The linear, cubic and quintic (5th order) electric field components for each electrode ring inside the IT were calculated using SIMION (SIMION version 8, Scientific Instrument Services, Ringoes, NJ, USA) simulations. The preferred electric fields with higher-order components were implemented experimentally by first calculating the potential on each electrode ring of the halo IT and then soldering appropriate capacitors between rings without changing the original trapping plate design. The performance of the halo IT was evaluated for 1% to 7% cubic electric field (A (4)/A (2)) component. A best resolution of 280 (m/Δm) for the 51-Da fragment ion of benzene was observed with 5% cubic electric field component. Confirming results were obtained using toluene, dichloromethane, and heptane as test analytes.
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Affiliation(s)
- Miao Wang
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA
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48
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Harris C, Kamat PV. Photocatalytic events of CdSe quantum dots in confined media. Electrodic behavior of coupled platinum nanoparticles. ACS Nano 2010; 4:7321-7330. [PMID: 21069993 DOI: 10.1021/nn102564x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The electrodic behavior of platinum nanoparticles (2.8 nm diameter) and their role in influencing the photocatalytic behavior of CdSe quantum dots (3.4 nm diameter) has been evaluated by confining both nanoparticles together in heptane/dioctyl sulphosuccinate/water reverse micelles. The particles spontaneously couple together within the micelles via micellar exchange processes and thus facilitate experimental observation of electron transfer reactions inside the water pools. Electron transfer from CdSe to Pt is found to occur with a rate constant of 1.22 × 10(9) s(-1). With the use of methyl viologen (MV(2+)) as a probe molecule, the role of Pt in the photocatalytic process is established. Ultrafast oxidation of the photogenerated MV(+•) radicals indicates that Pt acts as an electron sink, scavenging electrons from MV(+•) with a rate constant of 3.1 × 10(9) s(-1). The electron transfer between MV(+•) and Pt, and a drastically lower yield of MV(+•) under steady state irradiation, confirms the ability of Pt nanoparticles to discharge electrons quickly. The kinetic details of photoinduced processes in CdSe-Pt assemblies and the electrodic behavior of Pt nanoparticles provide important information for the development of light energy conversion devices.
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Affiliation(s)
- Clifton Harris
- Radiation Laboratory and Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, USA
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49
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Salari JWO, van Heck J, Klumperman B. Steric stabilization of Pickering emulsions for the efficient synthesis of polymeric microcapsules. Langmuir 2010; 26:14929-14936. [PMID: 20726532 DOI: 10.1021/la1025284] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
It is commonly known that Pickering emulsions are extremely stable against coalescence and are, therefore, potentially interesting for the synthesis of new materials, such as colloidosomes, microcapsules, composite particles, foams, and so on. However, for the efficient synthesis of such materials, one also has to consider the colloidal stability against aggregation, which is often neglected. In this study, it is demonstrated that steric stabilization is provided to Pickering emulsion droplets by the adsorption of poly(styrene-block-ethylene-co-propylene) (pS-b-EP) and that it is a requirement for the efficient synthesis of polymeric microcapsules. Monodisperse polystyrene particles of 648 nm are synthesized by soap-free emulsion polymerization. A model Pickering emulsion is then formed by the addition of sodium chloride at a critical concentration of 325 mM and mixing it with either heptane or decane. Subsequently, pS-b-EP is added to the Pickering emulsion to provide steric stabilization. Size exclusion chromatography is used to prove and quantify the adsorption of pS-b-EP onto the Pickering emulsion droplets. A maximum surface coverage of 1.3 mg/m(2) is obtained after 2 h, which is approximately one-third of the adsorption on a pure pS surface. We believe that the presence of polar sulfate groups on the particle, which initially stabilized the particle in water, reduces the adsorption of pS-b-EP. Microcapsules are formed by heating the Pickering emulsion above the glass-transition temperature of the particles. Significant aggregation is observed, if no pS-b-EP is used. The adsorption of pS-b-EP provides steric stabilization to the Pickering emulsion droplets, reduces aggregation significantly, and ultimately leads to the successful and efficient synthesis of pS microcapsules.
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Affiliation(s)
- Joris W O Salari
- Department of Polymer Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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50
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Mark H, Rubinovitz R, Heaps D, Gemperline P, Dahm D, Dahm K. Comparison of the use of volume fractions with other measures of concentration for quantitative spectroscopic calibration using the classical least squares method. Appl Spectrosc 2010; 64:995-1006. [PMID: 20828436 DOI: 10.1366/000370210792434314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Since the commercial development of modern near-infrared spectroscopy in the 1970s, analysts have almost invariably used units of weight percent as the measure of analyte concentration, due largely to the historical precedent from other analytical methods, including other spectroscopic techniques. The application of the CLS algorithm to a set of binary and ternary liquid mixtures reveals that the spectroscopic measurement sees the sample differently; that the measured absorbance spectrum is in fact sensitive to the volume fraction of the various components of the mixture. Because there is not a one-to-one relationship between volume fraction and other measures of analyte concentration, nor is the relationship linear, this has important implications for the application of both the CLS algorithm and the various other, more conventional, calibration algorithms that are commonly used.
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Affiliation(s)
- Howard Mark
- Mark Electronics, 69 Jamie Court, Suffern, New York 10901, USA.
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