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Yue Yu, Ya-Nan Wang, Wei Ding, Jianfei Zhou, Bi Shi
A series of highly-oxidized starch (HOS) were prepared using H2O2 and a copper-iron catalyst as a desired ligand for zirconium tanning of leather. The effects of catalyst and H2O2 dosages, and reaction temperature on the oxidation degree (OD, represented as the amount of carbonyl and carboxyl groups derived) of starch were investigated. The OD reached 76.2% when oxidation was conducted using 60% H2O2 and 0.015% catalyst at 98°C for 2h. (13)C NMR and FT-IR illustrated carbonyl and carboxyl groups were formed in HOS after oxidation...
October 15, 2017: Carbohydrate Polymers
Min Xiao, Edurne González, Alexis Martell Monterroza, Margaret Frey
A thermo-responsive polymer with hydrophilic to hydrophobic transition behavior, poly(vinyl caprolactam-co-hydroxyethyl acrylamide) P(VCL-co-HEAA), was prepared by copolymerization of vinyl caprolactam and N-hydroxyethyl acrylamide via free radical solution polymerization. The resulting copolymer was characterized by Fourier transform infrared spectroscopy (FTIR), (1)H nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA)...
October 15, 2017: Carbohydrate Polymers
Wei Xu, Ran Guan, Fushan Shi, Aifang Du, Songhua Hu
RAMP60, RAMP70, RAMP80 and RAMPtp extracted from the rhizome of Atractylodis macrocephalae Koidz. were chemically analyzed and tested for their lymphocyte stimulation. Among them, only RAMPtp was found to induce proliferation of lymphocytes from bovine supramammary lymph node (SMLN). It was found that RAMPtp was homogeneous polysaccharide with Mn of 1.867×10(3) by GPC analysis, composed of glucose, mannose, rhamnose, arabinose and galactose, with mass percentages of 60.67%, 14.99%, 10.61%, 8.83% and 4.90%, respectively by HPLC analysis, connected by 1, 3-linked β-D Galp and 1, 6-linked β-D Galp residues by NMR analysis and was amorphous in structure by SEM analysis...
October 15, 2017: Carbohydrate Polymers
Qijing Chen, Ting Shi, Fei Han, Zihan Li, Chao Lin, Peng Zhao
A hydrophobic CCS polymer of poly(benzyl methacrylate) (PBzMA) was prepared in toluene by reversible addition-fragmentation chain transfer (RAFT)-mediated dispersion polymerization. The CCS polymer, with poly(benzyl methacrylate) as the arm and crosslinked N, N'-bis(acryloyl)cystamine (BAC) as the core, was confirmed by characterization with gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. Three kinds of oils (toluene, anisole and styrene) were chosen to study the emulsification properties of PBzMA CCS polymer...
August 17, 2017: Scientific Reports
Zhiqiang Chen, Mo Li, Qinxue Wen, Nanqi Ren
Effluent organic matter (EfOM) is an emerging concern to receiving aquatic environment due to its refractory property. The degradation of EfOM in ozonation and other two advanced oxidation processes (AOPs), UV/H2O2 and UV/persulfate (PS), was investigated in this study. Fluorescence spectra coupled with parallel factor analysis (PARAFAC) and two-dimensional correlation gel permeation chromatography (2D-GPC) were used to track the evolution of EfOM during each oxidation process. Results showed that the degradation of EfOM indicated by dissolved organic carbon (DOC), UV254 and fluorescence components, fitted well with pseudo-first-order kinetic model during the oxidation processes...
August 4, 2017: Water Research
C-X Yang, T Wang, L-N Gao, H-J Yin, X Lü
AIMS: Lignin is an aromatic heteropolymer forming a physical barrier and is a big challenge in biomass utilization. This paper firstly investigated lignin-degradation bacteria from rotten wood in Qinling Mountain. METHODS AND RESULTS: 19 potential strains were selected and ligninolytic enzyme activities were determined during 84 h. The strains which had higher enzymes activities were selected. Further the biodegradation of wheat straw lignin and alkali lignin was evaluated, which indicated Burkholderia sp...
August 12, 2017: Journal of Applied Microbiology
Zhengyu Ma, Yi Wu, Jing Wang, Changsheng Liu
We present P(TMC-co-DLLA) copolymer with the molar ratio of TMC: DLLA = 15: 85 was used to systematic study of in vivo and in vitro degradation behaviors. Dense homogeneous copolymer specimens were prepared by compression molding method. The in vitro and in vivo degradation were, respectively, performed at simulative body condition and implanted into rat's subcutaneous condition. Investigations were followed via physicochemical and histological analysis such as SEM, GPC, DSC, FTIR and H&E stain. The results demonstrate that copolymeric material can degrade in phosphate buffer solution (PBS) and in rat's body, and the in vivo degradation rate is faster...
August 2017: Regenerative Biomaterials
Qianqian Li, Qiang Liu, Weijin Huang, Jiajing Wu, Jianhui Nie, Meng Wang, Chenyan Zhao, Li Zhang, Youchun Wang
Lassa virus (LASV) causes a severe hemorrhagic fever endemic throughout western Africa. Because of the ability to cause lethal disease in humans, limited treatment options, and potential as a bioweapon, the need for vaccines to prevent LASV epidemic is urgent. However, LASV vaccine development has been hindered by the lack of appropriate small animal models for efficacy evaluation independent of biosafety level four (BSL-4) facilities. Here we generated an LASV-glycoprotein precursor (GPC)-pseudotyped Human immunodeficiency virus containing firefly luciferase (Fluc) reporter gene as surrogate to develop a bioluminescent-imaging-based BALB/c mouse model for one-round infection under non-BSL-4 conditions, in which the bioluminescent intensity of Fluc was utilized as endpoint when evaluating vaccine efficacy...
August 7, 2017: Vaccine
Taha Mnasri, Françoise Ergan, Josiane Herault, Gaëlle Pencreac'h
In this work, the synthesis of oleoyl-lysophosphatidylcholine by lipase-catalyzed esterification of glycerophosphocholine (GPC) and free oleic acid in a reaction medium without solvent is presented. The complete solubilisation of GPC, which is a crucial issue in non-polar liquids such as melted free fatty acids, was reached by heating the GPC/oleic acid mixture at high temperature during a short time. The immobilized lipase from Rhizomucor miehei (Lipozyme RM-IM) was shown to catalyze the reaction more efficiently than the immobilized lipases from Thermomyces lanuginosus (Lipozyme TL-IM) and Candida antarctica (Novozym 435)...
August 8, 2017: Journal of Oleo Science
Mohd Faizan Siddiqui, Bilqees Bano
Cysteine proteinase inhibitors play an essential role in maintaining the proper functioning of all living cell by virtue of its thiol protease regulatory properties. Chemical denaturation of a new variant of cystatin super family has been studied by various biophysical techniques in order to characterize the unfolded and denatured state. Denaturation of garlic phytocystatin has been investigated using urea and guanidine hydrochloride (GdnHCl). Different biophysical techniques such as intrinsic fluorescence, circular dichroism and FTIR exhibited an altered structure of garlic phytocystatin with increasing concentration of denaturant...
August 5, 2017: International Journal of Biological Macromolecules
Aliyeh Ghamkhari, Bakhshali Massoumi, Roya Salehi
In this work,a novelthermo-responsive Fe3O4/poly(methylmethacrylate-b-N-isopropylacrylamide-b-acrylic acid) magnetic composite nanospherewas synthesized for anticancer drug delivery applications. For this propose, the poly(methylmethacrylate-b-N-isopropylacrylamide-b-acrylicacid) [poly(MMA-b-NIPAAm-b-AAc)] was synthesizedviareversible addition-fragmentation transfer (RAFT)method.The physic-chemical characterization of the Fe3O4/poly(MMA-b-NIPAAm-b-AAc) magnetic composite nanosphere was investigated by FTIR, HNMRspectroscopies and GPC,FESEM, XRD, VSM andDLS...
August 7, 2017: Journal of Biomaterials Science. Polymer Edition
Penphitcha Amonpattaratkit, Sureerat Khunmanee, Dong Hyun Kim, Hansoo Park
In this work, crosslinkers were prepared by conjugating high- and low-molecular-weight gelatin with different mole ratios of itaconic acid (IA) with double bonds. Then, the gelatin-itaconic acid (gelatin-IA) crosslinkers were compared with the gelatin-methacrylate (gelatin-MA) crosslinkers. The molecular weights and structures of gelatin-MA and gelatin-IA were confirmed using gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). Additionally, the swelling ratio and biodegradation properties of the hydrogels using IA as starting monomers and gelatin-IA and gelatin-MA as crosslinkers were investigated...
July 19, 2017: Materials
Yi-Cheng Feng, Hui Zhao, Tong-Hui Hao, Guo-Hua Hu, Tao Jiang, Qun-Chao Zhang
To understand the role of molecular structure on the crystallization behavior of copolyester in thermoplastic poly(ether ester) elastomers (TPEEs), series of poly(butylene-co-1,4-cyclohexanedimethylene terephthalate) (P(BT-co-CT))-b-poly(tetramethylene glycol) (PTMG) are synthesized through molten polycondensation process. The effects of poly(cyclohexanedimethylene terephthalate) (PCT) content on the copolymer are investigated by Fourier transform infrared spectroscopy (FT-IR), ¹H and (13)C nuclear magnetic resonance (NMR), gel permeation chromatographs (GPC), wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), mechanical, and visible light transmittance tests...
June 24, 2017: Materials
Xiaoyu Gao, Changzhen Zhan, Xiaoliang Yu, Qinghua Liang, Ruitao Lv, Guosheng Gai, Wanci Shen, Feiyu Kang, Zheng-Hong Huang
The natural Sri Lanka graphite (vein graphite) is widely-used as anode material for lithium-ion batteries (LIBs), due to its high crystallinity and low cost. In this work, graphitic porous carbon (GPC) and high-purity vein graphite (PVG) were prepared from Sri Lanka graphite ore by KOH activation, and high temperature purification, respectively. Furthermore, a lithium-ion capacitor (LIC) is fabricated with GPC as cathode, and PVG as anode. The assembled GPC//PVG LIC shows a notable electrochemical performance with a maximum energy density of 86 W·h·kg(-1) at 150 W·kg(-1), and 48 W·h·kg(-1) at a high-power density of 7...
April 14, 2017: Materials
Mahrzadi Noureen Shahi, Muhammad Arshad, Aman Ullah
Solvent-free copolymerization of epoxides derived from fatty esters of waste cooking oil with phthalic anhydride using (salen)Cr(III)Cl as catalyst and n-Bu₄NCl/DMAP (tetrabutylammonium chloride/4-(dimethylamino)pyridine) as co-catalysts was carried out for the first time under microwave irradiation, where reaction time was reduced from a number of hours to minutes. The polyesters were obtained with molecular weight (Mw = 3100-6750 g/mol) and dispersity values (D = 1.18-1.92) when (salen)Cr(III)Cl/n-Bu₄NCl was used as catalysts...
March 20, 2017: Materials
Eric S Cueny, Heather C Johnson, Bernie J Anding, Clark R Landis
Chromophore quench-labeling applied to 1-octene polymerization as catalyzed by hafnium-pyridyl amido precursors enables quantification of the amount of active catalyst and observation of the molecular weight distribution (MWD) of Hf-bound polymers via UV-GPC analysis. Comparison of the UV-detected MWD with the MWD of the "bulk" (all polymers, from RI-GPC analysis) provides important mechanistic information. The time evolution of the dual-detection GPC data, concentration of active catalyst, and monomer consumption suggests optimal activation conditions for the Hf pre-catalyst in the presence of the activator [Ph3C][B(C6F5)4]...
August 18, 2017: Journal of the American Chemical Society
Selasi Dankwa, Mudit Chaand, Usheer Kanjee, Rays H Y Jiang, Luis V Nobre, Jonathan M Goldberg, Amy K Bei, Mischka A Moechtar, Christof Grüring, Ambroise D Ahouidi, Daouda Ndiaye, Tandakha N Dieye, Souleymane Mboup, Michael P Weekes, Manoj T Duraisingh
Plasmodium falciparum, the parasite that causes the deadliest form of malaria, has evolved multiple proteins known as invasion ligands that bind to specific erythrocyte receptors to facilitate invasion of human erythrocytes. The EBA-175/glycophorin A (GPA) and Rh5/basigin ligand-receptor interactions, referred to as invasion pathways, have been the subject of intense study. In this study, we focused on the lesser characterized sialic acid-containing receptors glycophorin B (GPB) and glycophorin C (GPC). Through bioinformatic analysis, we identified extensive variation in glycophorin B transcript (GYPB) levels in individuals from Benin, suggesting selection from malaria pressure...
July 31, 2017: Infection and Immunity
Laxmi, Shabnam Khan, Abdul Kareem, Fahmina Zafar, Nahid Nishat
A series of novel coordination polyurethanes [HTPU-M, where M=Mn(II) 'd(5)', Ni(II) 'd(8)', and Zn(II) 'd(10)'] have been synthesized to investigate the effect of divalent metal ions coordination on structure, thermal and adsorption properties of low molecular weight hydroxyl terminated polyurethane (HTPU). HTPU-M have been synthesized in situ where, OH group of HTPU (synthesized by the condensation polymerization reaction of ethylene glycol (EG) and toluene diisocyanate (TDI) in presence of catalyst) on condensation polymerization with metal acetate in presence of acid catalyst synthesized HTPU-M followed by coordination of metal ions with hetero atoms...
July 21, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Lida Ahmadkhani, Abolfazl Akbarzadeh, Mojtaba Abbasian
A drug delivery system based on dual responsive units was developed. An appealing pH- and thermo-responsive triblock terpolymer as the drug carrier was synthesized by RAFT polymerization of N-isopropyl acrylamide and methacrylic acid monomers using PEG-RAFT agent. The Fe3O4 magnetic nanoparticles were synthesized by co-precipitation of Fe salts. Synthesized samples were characterized by FT-IR, XRD, GPC, SEM and TEM. The dual responsive behaviour and self-assembly of the triblock terpolymers in aqueous solution were investigated using UV-vis transmittance and DLS...
July 28, 2017: Artificial Cells, Nanomedicine, and Biotechnology
Sabrina Bertini, Giulia Risi, Marco Guerrini, Kevin Carrick, Anita Y Szajek, Barbara Mulloy
In a collaborative study involving six laboratories in the USA, Europe, and India the molecular weight distributions of a panel of heparin sodium samples were determined, in order to compare heparin sodium of bovine intestinal origin with that of bovine lung and porcine intestinal origin. Porcine samples met the current criteria as laid out in the USP Heparin Sodium monograph. Bovine lung heparin samples had consistently lower average molecular weights. Bovine intestinal heparin was variable in molecular weight; some samples fell below the USP limits, some fell within these limits and others fell above the upper limits...
July 19, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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