bluuebunny/crossref_metadata_2025_split huggingface dataset:
PrEP and the syndemic of substance use, violence, and HIV among female and male sex workers: a qualitative study in Kisumu, Kenya
Authors: Bazzi Angela R , Yotebieng Kelly , Otticha Sophie , Rota Grace , Agot Kawango , Ohaga Spala , Syvertsen Jennifer L 
Published: April 2019

AbstractIntroductionFemale and male sex workers experience heightened vulnerability to HIV and other health harms that are compounded by substance use, physical and sexual violence, and limited access to health services. In Kisumu, Kenya, where sex work is widespread and substance use is a growing public health concern, offering pre‐exposure prophylaxis (PrEP) for HIV prevention could help curtail the HIV epidemic. Our study examines “syndemics,” or mutually reinforcing epidemics of substance use, violence and HIV, in relation to PrEP acceptability and feasibility among female and male sex workers in Kenya, one of the first African countries to approve PrEP for HIV prevention.MethodsFrom 2016 to 2017, sex workers in Kisumu reporting recent alcohol or drug use and experiences of violence participated in qualitative interviews on HIV risk and perspectives on health service needs, including PrEP programming. Content analysis identified themes relating to PrEP knowledge, acceptability, access challenges and delivery preferences.ResultsAmong 45 female and 28 male sex workers, median age was 28 and 25 respectively. All participants reported past‐month alcohol use and 91% of women and 82% of men reported past‐month drug use. Violence was pervasive, with most women and men reporting past‐year physical (96% women, 86% men) and sexual (93% women, 79% men) violence. Concerning PrEP, interviews revealed: (1) low PrEP knowledge, especially among women; (2) high PrEP acceptability and perceived need, particularly within syndemic contexts of substance use and violence; and (3) preferences for accessible, non‐stigmatizing PrEP delivery initiatives designed with input from sex workers.ConclusionsThrough a syndemic lens, substance use and violence interact to increase HIV vulnerability and perceived need for PrEP among female and male sex workers in Kisumu. Although interest in PrEP was high, most sex workers in our sample, particularly women, were not benefiting from it. Syndemic substance use and violence experienced by sex workers posed important barriers to PrEP access for sex workers. Increasing PrEP access for sex workers will require addressing substance use and violence through integrated programming.
Does Shorter Postnatal Hospital Stay Lead to Postdischarge Complications? An Instrumental Variables Approach
Authors: Rahman Mohammad Mahbubur , Pallikadavath Saseendran , Khatoon Rabeya 
Published: April 2019

AbstractWe exploit the difference in means of postnatal hospital stays between beneficiary mothers of Janani Suraksha Yojana (JSY) and control mothers to estimate causal effects of postnatal hospital stay on postdischarge complications of a mother and her newborn. We argue that JSY increases the demand for institutional deliveries in those hospitals, which are assigned by the government to provide such services to the JSY recipients. Given the limited supply of beds, health professionals and other facilities, an excess demand for institutional deliveries in those hospitals forces JSY recipients to stay for a shorter time after birth compared with nonrecipients of JSY who are free to deliver in any hospital. Thus, the dummy for JSY becomes a suitable instrument for postnatal hospital stay. Using instrumental variables (IV) regressions, we find that postnatal hospital stay has statistically significant negative causal effects on half of the available postdischarge complications in the data, including abdominal pain, vaginal discharge, convulsion and severe headache of a mother and fever or cold of the newborn. © 2019 John Wiley & Sons, Ltd.
Measuring near‐saturated hydraulic conductivity of soils by quasi unit‐gradient percolation—1. Theory and numerical analysis
Authors: Sarkar Subharthi , Germer Kai , Maity Rajib , Durner Wolfgang 
Published: April 2019

AbstractThe saturated and near‐saturated hydraulic conductivity of soils, ku, is a sensitive indicator of soil structure and a key parameter for solute transport and soil aeration. In this contribution, we present and numerically investigate a double‐disk method to determine ku in the laboratory by steady‐state percolation at different suction steps. Tension infiltration of water takes place at the top of a soil column through a porous disk with a smaller diameter than the soil sample. This leaves part of the soil surface open and ensures a proper soil ventilation. Drainage takes place at the base through a porous disk with the full diameter of the soil column at exactly the same tension as applied to the top boundary. Since the infiltration area is less than the percolation area, the water flow diverges and the equality of steady flow rate and hydraulic conductivity, which characterizes the standard unit‐gradient experiment, is no longer valid. To develop a general relationship between observed steady flow rate and unsaturated hydraulic conductivity, the experiment was simulated with the Richards‐equation solver HYDRUS 2D/3D, for twelve different soil classes. We found for tensions in the range 1 cm < 10 cm, an infiltration disk diameter of 4.5 cm diameter and a sample diameter of 8 cm diameter that the flux rate at any given tension was about 0.7 times the respective hydraulic conductivity, with an error of less than 10%.
Reactivity of oil‐soluble IL with silicon surface at elevated temperature
Authors: Al‐Sallami Waleed , Parsaeian Pourya , Dorgham Abdel , Neville Anne 
Published: April 2019

AbstractThe reactivity of an oil‐miscible ionic liquid, phosphonium phosphate (PP), and the common anti‐wear additive zinc dialkyl dithio phosphate (ZDDP) with a solid surface at elevated temperature in the absence of any tribological motion is investigated. Understanding the thermal film build up, composition, and relative thickness will help in the understanding of lubrication mechanisms once tribological effects are introduced. Attenuated total reflection–Fourier transform infrared (ATR‐FTIR), scanning electron microscopy–energy dispersive spectroscopy (SEM‐EDS), and X‐ray photoelectron spectroscopy (XPS) are employed to characterise silicon surfaces before and after the experiments in terms of surface chemistry and surface morphology. The results show that both additives react with the silicon surface to produce thermal films. However, ZDDP forms a thicker film. PP reacts with the silicon and forms a thermal film, but the reaction rate is self‐limited such that an increase of time to 24 hours does not significantly increase the film thickness.
Cross‐relaxation parameters in cortical bone assessed with different MR sequences
Authors: Bouazizi Khaoula , Guillot Geneviève 
Published: April 2019

This study aimed to show evidence of MR cross‐relaxation effects in cortical bone and to compare different MR sequences for the quantification of cross‐relaxation parameters.Measurements were performed on bovine diaphysis samples with spectroscopic methods (inversion‐recovery, off‐resonance saturation) and with a variable flip angle (VFA) UTE imaging method on a 4.7 T laboratory‐assembled scanner. Cross‐relaxation parameter assessment was carried out via a two‐pool model simulation with a matrix algebra approach.A proton signal amplitude of 28 Mol/L was observed (equivalent water fraction of 25%). It was attributed to collagen‐bound water, with
values of ~ 0.3 ms, a “long‐T2” proton pool, in exchange with protons from the collagen macromolecules (
of 10–20 μs). Magnetization transfer (MT) effects were detected with all sequences. The best precision of model parameters was obtained with off‐resonance saturation; the fraction of collagen methylene protons was found in the range of 22–28% and the transverse relaxation time for collagen methylene protons was 11 μs (1% precision).The model parameters obtained were compatible with VFA‐UTE results but could not be assessed with acceptable accuracy and precision using this method. In vivo MT quantification using off‐resonance saturation with a single B1 amplitude and offset frequency may provide information about the relative amount of collagen per unit volume in cortical bone.
Synthesis and in situ functionalization of microfiltration membranes via high internal phase emulsion templating
Authors: Malakian Anna , Zhou Muchu , Zowada Ryan T , Foudazi Reza 
Published: April 2019

AbstractThe continuous phase of high internal phase emulsions (HIPEs) can be polymerized to produce highly porous materials, known as polyHIPEs. The aim of this work was to synthesize polyHIPE microfiltration membranes having a hydrophobic bulk and a hydrophilic surface to enhance their performance. Therefore, in situ functionalization was performed through interfacial copolymerization of a hydrophobic monomer (butyl acrylate) in the continuous phase with a hydrophilic monomer (sodium acrylate) in the disperse phase. The functionalization of polyHIPEs was studied by using conductometric titration and Fourier transform IR spectroscopy. We show that the surface charge density of poly(butyl acrylate)‐based polyHIPEs can be controlled by varying the concentration of sodium acrylate in the disperse phase. PolyHIPE microfiltration membranes have higher intrinsic permeability (around 1.31 × 10−8 m2) in comparison to conventional microfiltration membranes. The interfacial copolymerization of sodium acrylate increases the permeability of microfiltration membranes. In addition, the rejection of polyHIPE microfiltration membranes was studied for the separation of microalgae. © 2019 Society of Chemical Industry
Theoretical design on molecular tweezers of sodium cyanide by zinc porphyrin‐azo‐crown ether triads receptor
Authors: Li Hui , Zhang Ying , Jia Zishang , Wang Xueye 
Published: April 2019

AbstractTheoretical study on a novel zinc porphyrin‐azobenzene‐crown ether triads receptor was explored. The(Z)‐5‐(4‐((4‐((4‐((4‐(1,4,7,10,13‐pentaoxacyclopentadecan‐2‐yl)benzyl)oxy)phenyl) diazenyl)phenoxy) methyl)phenyl)porphyrin (L1), the complex L2 (L1 with the metal ion Zn2+), and the corresponding complex L2 of ditopic receptor with sodium cyanide are investigated by density functional theory (DFT). The full optimized geometric structures are calculated at PBE0/6‐311G** level, natural bond orbital (NBO) analysis is used to study the interaction of L2 and L2·NaCN molecules. The absorption spectra of L1, L2, and L2·NaCN are studied by time‐dependent DFT (TD‐DFT) and CAM‐B3LYP method. DFT calculations show that the geometric structure of compound L2 binding sodium cyanide change greatly. The absorption peak is significant red‐shifted because of the formation of a 1:1 complex with sodium cyanide. Furthermore, it demonstrates that novel zinc porphyrin‐azo‐crown ethimer triads L2 is suitable ditopic receptor to recognize sodium cyanide salt.
tau‐Fluvalinate and other pesticide residues in honey bees before overwintering
Authors: Erban Tomas , Vaclavikova Marta , Tomesova Daniela , Halesova Tatana , Hubert Jan 
Published: April 2019

AbstractBACKGROUNDPesticides have often been linked to honey bee colony losses, which occur mainly over winter. In this study, we investigated residues in nine colonies at a model agricultural research site during the period before wintering. Moreover, we applied the acaricide tau‐fluvalinate to the colonies via a strip formulation. The pesticide content was determined by UHPLC‐QqQ‐MS/MS in bees from brood comb initially collected in mid‐September immediately prior to the start of tau‐fluvalinate treatment and 30 later at the time of tau‐fluvalinate strip removal.RESULTSIn addition to commonly analyzed pesticides, we detected two plant growth regulators, chlormequat and metazachlor, in the bee colonies. Whereas thiacloprid, chlormequat and acetamiprid decreased after 30 days and contributed considerably to differences between sample time points, other pesticides appeared to be rather stable. Interestingly, we identified diazinon, which has been banned in the European Union since 2007. The residues of methiocarb sulfoxide and imidacloprid‐urea in the absence of their parent compounds indicate historical environmental contamination that can be identified by the detection of residues in a bee colony. tau‐Fluvalinate was detected only after the 30‐day treatment at an average (± SD) concentration of 1.29 ± 1.93 ng/bee, ranging from 0.06 to 7.13 ng/bee.CONCLUSIONThe multidimensional behavior of pesticides in a bee colony was indicated. Although the research area is used for agriculture, the measured pesticide level was relatively low. The recorded concentrations of tau‐fluvalinate should not be dangerous to bees, as the values were ∼ 200–5000‐fold lower than the reported median lethal dose (LD50) values. © 2019 Society of Chemical Industry
Synthesis, Physicochemical Properties and Anti‐Fatigue Effect of Magnesium, Zinc and Chromium Polygalacturonate Based Composition
Authors: Milyukov Vasilii A. , Khabibullina Anna V. , Arkhipova Daria M. , Mironov Vladimir F. , Khamatgalimov Ayrat R. , Ryzhkina Irina S. , Murtazina Leysan I. , Mironova Lubov G. , Vyshtakalyuk Alexandra B. , Nemtarev Andrey V. , Nazarov Nail G. , Kholin Kirill V. , Nizameev Irek R. , Minzanova Salima T. 
Published: April 2019

AbstractThe present study is focused on the development of a composition based on three pectin metal complexes (NaMg‐PG, NaZn‐PG and NaCr‐PG) at a mass ratio 7:0.3:0.001. It was evaluated by the methods of infrared spectroscopy (IR spectroscopy), atomic force microscopy (AFM), dynamic light scattering (DLS) and TEM‐EDS. The data, obtained by simultaneous thermal analysis and Fourier transform IR spectroscopy, showed that water was the main component of the gas phase at the first stage of mass loss of the specified compounds, whereas further heating led to decarboxylation and degradation. The results of Forced Swim Test (FST) showed that the specified composition at the dose of 50–100 mg/kg contributed to the stimulation of an organism‘s adaptive capacity under intensive physical loads and could be considered as a potential adaptogen and stimulator of erythropoiesis that could normalize metabolism.
Fabrication and 3D Patterning of Bio‐Composite Consisting of Carboxymethylated Cellulose Nanofibers and Cobalt Ferrite Nanoparticles
Authors: Limaye Mukta V. , Sahoo Pradosh Kumar , Shirolkar Mandar , Singh Shashi B. , Khare Amit , Shao Yu‐Cheng , Chen Kuan‐Hung , Qiu Xian‐Sheng , Hsieh Shang‐Hsien , Rana Dhanvir Singh , Pong W. F. 
Published: April 2019

AbstractIn this work, flexible and free‐standing films of bio‐composite of carboxymethylated cellulose nanofibers (CMCNF) and cobalt ferrite (CFO) nanoparticles (NPs) have been fabricated using in‐situ chemical route. Control over CFO fraction (1% ‐ 25%) in CMCNF matrix was achieved by adjusting volume of the iron and cobalt precursors. Free‐standing films of CMCNF‐CFO bio‐composite were characterized using X‐ray diffraction, spectroscopic, microscopic, thermal and Magnetic measurements. The Raman and X‐ray absorption near edge spectroscopy studies confirms the formation of CFO in CMCNF matrix. The microscopic studies revealed that CMCNF fibers are decorated with CFO NPs having size of the order of ∼ 25 nm. Comparison of the thermal properties of CMCNF and CMCNF ‐CFO composites shows that thermal stability improves as CFO content increases. Finally, preliminary results on a method to create 3D patterns of CMCNF ‐CFO nanocomposite having lateral dimensions ∼1.2 μm were presented that pave the way to new uses of bio‐composites.
Synthesize and Characterization of 2‐Aminothiazole Monomer and Polymer‐based Bifunctional Fe/N/C Catalysts for Oxygen and Carbon Dioxide Reduction Reactions
Authors: Zhang Qi , Jiang Hui , Niu Dongfang , Zhang Xinsheng , Sun Shigang , Hu Shuozhen 
Published: April 2019

Abstract2‐aminothiazole monomer (AT‐monomer) and polymer (AT‐polymer) are utilized as the nitrogen source to synthesize the Fe/N/C catalysts. The polymerization effect of nitrogen source for Fe/N/C catalysts on their bifunctional activity toward oxygen reduction reaction (ORR) and CO2 reduction reaction (CO2RR) is investigated. Both AT‐monomer‐Fe/N/C and AT‐polymer‐Fe/N/C contain pyridine N (including Fe−N) and graphitic N in the structure, resulting in displaying bifunctional activity toward ORR and CO2RR. The 2‐aminothiazole polymer structure is important to produce graphene structured nanosheets with higher amount of defect sites and more pyridinic N (including Fe−N) and graphitic N in AT‐polymer‐Fe/N/C than those in AT‐monomer‐Fe/N/C synthesized from 2‐aminothiazole monomers. With the structure advantages, AT‐polymer‐Fe/N/C displays superior bifunctional catalytic performance. It has higher catalytic efficiency than commercial Pt/C for ORR and high CO selectivity (92%) with 4.2 mA cm–2 at overpotential of 0.47 V for CO2RR than that of AT‐monomer‐Fe/N/C.
CoFe2O4@SiO2@Co(III) Salen Complex: A Magnetically Recyclable Heterogeneous Catalyst for the Synthesis of Quinoline Derivatives in Water
Authors: Hemmat Kaveh , Nasseri Mohammad Ali , Allahresani Ali 
Published: April 2019

AbstractIn this study, a description is made upon the preparation, characterization and catalytic application of CoFe2O4@SiO2@Co(III) salen complex, i. e., Co(III) salen complex loaded on cobalt ferrite‐silica nanoparticle. TEM, SEM‐EDX, VSM, FT‐IR analyses were used to characterize the complex. Thermal gravimetric analysis (TGA) was also used to determine the thermal stability of the material. Using Scherrer's approximation, an average crystallite size is determined from the full width at half maximum of strongest reflection by powder X‐ray diffractometry (XRD). The efficiency is studied for CoFe2O4@SiO2@Co(III) salen complex in quinolines of various 1,3‐dicarbonyls synthesizing with 2‐aminobenzophenone. Good to excellent yields (85–96%) are given to corresponding products by excellent catalytic activity that is demonstrated by the nanocatalyst. Moreover, the investigation of CoFe2O4@SiO2@Co(III) salen complex revealed that nanocatalyst could be recovered and reused at least five times without any appreciable decrease in activity and selectivity. This confirms its high efficiency and high stability under the reaction conditions and during recycling stages.
Catalytic Enhancement of Aldol Condensation by Oxygen Vacancy on CeO2 Catalysts
Authors: Liang Zhe , Jiang Dahao , Fang Geqian , Leng Wenhua , Tu Pengxiang , Tong Yuqin , Liu Liu , Ni Jun , Li Xiaonian 
Published: April 2019

AbstractAldol condensation is a very useful reaction for biomass upgrading by coupling small molecule platform compounds into high value‐added products. Here we choose acetaldehyde (AcH) condensation, the rate‐determining step in bioethanol transformations, as a targeted reaction, and prepared four CeO2 catalysts with different concentrations of surface oxygen vacancies to investigate the role of oxygen vacancies in this reaction. To the best of our knowledge, it is the first time to demonstrate that there is a linear correlation between the activity of aldol condensation and the concentration of oxygen vacancies. Based on in‐situ FTIR studies, we conclude that oxygen vacancies are the Lewis acid sites for activation and stabilization of AcH, while lattice oxygen act as base sites for the formation of enolate species which are the key intermediates for AcH coupling reactions. Moreover, the proposed reaction mechanism indicates that Ce cations which are weak Lewis acid sites are not involved in the AcH condensation.
Studies on CuCe0.75Zr0.25Ox preparation using bacterial cellulose and its application in toluene complete oxidation
Authors: Yan Ningna , Hao Qinglan , Zhao Chenchen , Yang Deyu , Dou Baojuan , Hui K.S. , Hui Kwun Nam 
Published: April 2019

AbstractA series of CuCe0.75Zr0.25Ox catalysts (CCZ) were synthesized based on the environmental‐friendly bacterial cellulose (BC) by using the sol‐gel method. The corresponding synthesis mechanism, physicochemical properties of the catalysts and catalytic performances for toluene oxidation were comprehensively studied. In the presence of BC without sugar, the CCZ−A synthesized by ethanol‐gel exhibits better catalytic activity than the CCZ−W synthesized by water‐gel, which may be due to the different roles of BC in different solvents. However, it is worth noting that the graft copolymerization between BC and active metal (Ce4+, Cu2+) is the same process in both water‐gel and ethanol‐gel. The activity of CCZ‐SW synthesized by water‐gel using BC with sugar is obviously higher than that of CCZ−W and CCZ−A. The temperature of complete degradation of toluene over CCZ‐SW is 205 °C, which is 35 °C lower than that of CCZ−W. The results from BET, Raman and H2‐TPR indicate that the larger the specific surface area, the more oxygen vacancies and better low‐temperature reducibility, that are mainly responsible for the excellent activity of CCZ‐SW. The existence of sugar in BC could hinder the agglomeration of active metal particles during the calcination process. Combined with the results of in situ DRIFT, the adsorbed toluene on the catalyst surface is oxidized into alkoxide, aldehydic and carboxylic acid species as intermediates before the complete oxidation into CO2 and H2O.
Enantioseparation of basic drugs by capillary electrochromatography using a stationary phase of transfersomes
Authors: Huang Zhifeng , Du Yingxiang , Li Xiaoqi , Sun Xiaodong , Feng Zijie , Ma Xiaofei 
Published: April 2019

AbstractTransfersomes, a special kind of phospholipid vesicles with higher deformability and flexibility, were applied as coating material to prepare a transfersomes‐coated capillary column. A capillary electrochromatography enantioseparation system based on the new transfersomes‐coated column with carboxymethyl‐β‐cyclodextrin added to the running buffer as a chiral selector was established for the first time. Compared with a bare column, three basic drugs achieved baseline separation with better resolution (3.17 for Propranolol, 2.38 for Metoprolol, 2.34 for Esmolol) in this transfersomes‐electrochromatography system. Several important parameters including concentration of chiral selector, buffer pH and applied voltage were systematically investigated to provide the optimal separation condition. This study constructed a flexible and efficient enantioseparation electrochromatography system with a small amount of transfersomes, and showed that transfersomes as the stationary phase could efficiently improve chiral separation effect.