bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hierarchical Zn/Ni‐MOF‐2 Nanosheet‐Assembled Hollow Nanocubes for Multicomponent Catalytic Reactions
Authors: Zhang Zhicheng , Chen Yifeng , He Su , Zhang Jingchao , Xu Xiaobin , Yang Yong , Nosheen Farhat , Saleem Faisal , He Wei , Wang Xun 
Published: July 2014

AbstractMetal‐organic frameworks (MOFs) are potentially useful molecular materials that can exhibit structure flexibilities induced by some external stimuli. Such structure transformations can furnish MOFs with improved properties. The shape‐controlled growth of MOFs combined with crystal‐structure transformation is rarely achieved. Herein, we demonstrate the synthesis of hierarchical Zn/Ni‐MOF‐2 nanosheet‐assembled hollow nanocubes (NAHNs) by a facile surfactant‐free solvothermal approach. The unique nanostructures undergo crystal‐structure transformation from Zn/Ni‐MOF‐5 nanocubes to Zn/Ni‐MOF‐2 nanosheets, which is analogous to the dissolution and recrystallization of inorganic nanocrystals. The present synthetic strategy to fabricate isostructural MOFs with hierarchical, hollow, and bimetallic nanostructures is expected to expand the diversity and range of potential applications of MOFs.
A comprehensive study on mechanism of formation and techniques to diagnose asphaltene structure; molecular and aggregates: a review
Authors: Hosseini‐Dastgerdi Z. , Tabatabaei‐Nejad S.A.R. , Khodapanah E. , Sahraei E. 
Published: July 2014

AbstractAs the formation of asphaltene aggregates causes its deposition in various processes, exact determination of the molecular and aggregate structure and mechanism of aggregate formation is very important in order to prevent asphaltene deposit formation. The aim of this paper is to review the molecular and aggregate structure of asphaltene using various techniques. The other purpose is to specify and compare different mechanisms of aggregate formation, suggested by researchers. These mechanisms are proposed by researchers according to the molecular characteristics of asphaltene and the structure of aggregates. Researchers have considered four general models for the formation mechanism of asphaltene aggregates: the micellar/colloidal, polymeric, solubility, and modified Yen models. In comparison with other models, the modified Yen model shows more consistency with new studies, which determine the island molecular structure and small nano‐aggregates for asphaltene. Experimental studies show that the dominant mechanism of aggregate formation depends on asphaltene architecture, intermolecular forces, and the solubility definition of asphaltene. Depending on the asphaltene source, solvent, thermodynamic conditions, and various techniques such as near‐infrared spectroscopy, nuclear magnetic resonance, small‐angle neutron scattering, and small‐angle X‐ray scattering, different structural information on the shape (spheres, discoid, oblate, membrane‐like, prolate cylinders, and mass fractal aggregates) and size of aggregates has been reported. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Designing and preparing of quercetin surface‐imprinted material and its molecular recognition characteristics
Authors: Gao Baojiao , Zhang Yanyan , Chen Tao 
Published: July 2014

ABSTRACTQuercetin is an important compound of flavonoids. In this work, quercetin molecule surface‐imprinted material with high performance was prepared using a novel surface‐imprinting technique of “synchronously graft‐polymerizing and imprinting.” The modified micron‐sized silica gel particles containing amino groups were used as matrix, methacrylic acid (MAA) was used as functional monomer, and N,N′‐Methylenebisacrylamide (MBA) was used as crosslinker. In dimethyl formamide solution of quercetin, MAA molecules arranged automatically around the template quercetin molecule by right of hydrogen bonding interactions of two type, ordinary hydrogen bond and π‐type hydrogen bond. By initiating the surface‐initiating system of –
, the graft/cross‐linking polymerization of MAA on SiO2 particles and the quercetin molecule surface‐imprinting were simultaneously carried out, forming quercetin molecule surface‐imprinted material MIP‐PMAA/SiO2. With another two flavonoids, rutin and genistein, as contrasting substances, the molecule recognition character of the quercetin molecule surface‐imprinted material MIP‐PMAA/SiO2 was investigated with batch and column methods. The experimental results show that the imprinted material MIP‐PMAA/SiO2 possesses special recognition selectivity and excellent binding affinity for quercetin molecule. The binding capacity of MIP‐PMAA/SiO2 for quercetin is 0.325 mmol/g, and its selectivity coefficients for quercetin relative to rutin and genistein are 7.69 and 4.40, respectively. The main conditions of imprinting process affect the property of MIP‐PMAA/SiO2 greatly, and the optimal molar ratio of monomer MAA to crosslinker MBA is 7 : 1 and appropriate molar ratio of monomer MAA to template quercetin is equal to 6 : 1. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41112.
Cotton‐fabric‐grafted poly(N‐isopropyl acrylamide) initiated by ammonium peroxydisulfate
Authors: Jian Nenmei , Xu Tao 
Published: July 2014

ABSTRACTIn this article, we report that thermoresponsive poly(N‐isopropyl acrylamide) (PNIPAAm) was successfully grafted onto a cotton fabric (CF) surface by free‐radical solution grafting polymerization; we obtained a thermoresponsive CF‐grafted PNIPAAm. This reaction system only contained four constituents: the monomer, solvent, initiator, and CFs. Ammonium peroxydisulfate was chosen as the initiator, and water was chosen as the solvent. A series of initiator concentrations and grafting polymerization temperatures were used in the experiments, and their effects on the grafting ratio (G) were also studied. Also, the effects of the G of CF‐g‐PNIPAAm on their corresponding thermoresponses was studied further. The structure of CF‐g‐PNIPAAm was characterized by Fourier transform infrared spectroscopy–attenuated total reflectance analysis and scanning electron microscopy analysis. The G of CF‐g‐PNIPAAm was measured by a gravimetric method. The thermoresponse of CF‐g‐PNIPAAm was characterized by modulated differential scanning calorimetry, water contact angle measurements, and wetting time measurements. The experiments manifested the following results: (1) the initiator concentration and grafting polymerization temperature both influenced G, (2) the grafted PNIPAAm covered the CF surface, (3) the CF‐g‐PNIPAAm showed thermoresponsive hydrophilicity/hydrophobicity, and (4) a relationship existed between the thermoresponse of CF‐g‐PNIPAAm and the corresponding G. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41193.
Modification of chitosan onto PE by irradiation in salt solutions and possible use as Cu2+ complex film for pest snail control
Authors: Pasanphan Wanvimol , Haema Kamonwon , Tangthong Theeranan , Piroonpan Thananchai 
Published: July 2014

ABSTRACTChitosan‐grafted‐polyethylene (CS‐g‐PE) film was prepared using simultaneous radiation‐inducing grafting technique. The copper ion (Cu2+) adsorptivity on the CS‐g‐PE film was determined. The CS‐hydroxybenzyltriazole (CS‐HOBt), CS‐N‐hydroxysuccinimide (CS‐NHS), CS‐acetic acid (CS‐HOAc), and CS‐glutathione (CS‐GSH) were used as CS‐salts in aqueous solutions. Among these grafting solution systems, the CS‐g‐PE film prepared from CS‐HOBt solution showed the greatest grafting amount and highest Cu2+ adsorptivity, up to 30.2% (1.51 ppm, 7.56 µg cm−2). The effects of the CS‐HOBt concentration and mixing solution on the grafting amount were also observed to clarify their efficacies to assist radiation‐induced grafting reaction. SEM/EDS mapping, ICP and XRF were used to clarify the Cu2+ adsorption capacity of the CS‐g‐PE film and the stability of Cu2+ on the CS‐g‐PE complex film. The Cu2+ showed its stability on the CS‐g‐PE film at room temperature in neutral and basic solutions. The Cu2+‐‐‐CS‐g‐PE complex film reduced pest snail breeding as high as 54%. The success of this observation is a new approach to modify PE surface with a functional biopolymer, CS containing Cu2+ complex for controlling pest snail breeding. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41204.
Synthesis of macroporous monolithic materials from a waste renewable source
Authors: Forgacz Claire , Birot Marc , Deleuze Hervé 
Published: July 2014

ABSTRACTInterconnected porous monolithic materials can be directly obtained from non‐templating methods by reacting raw Kraft black liquor with epichlorohydrin either in the presence or not of surfactant, whereas extracted lignin leads to non‐porous materials. In the presence of a surfactant, micelles organization takes place and porosity of 40–60% can be achieved. Without surfactant, chemically induced phase separation occurs, giving materials with agglomerated nodules morphology. Carbonization followed by activation with CO2 yield monolithic micro/mesoporous carbons with surface area of 300 m2 g−1. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41215.
Improved thermostability and interfacial matching of nanoclay filler and ethylene vinyl alcohol matrix by silane‐modification
Authors: Geyer Björn , Röhner Stefan , Lorenz Günter , Kandelbauer Andreas 
Published: July 2014

ABSTRACTThe interfacial compatibility between polymers and nanoclay fillers as well as the thermostability of both components are important characteristics for processing them into polymer composites. While the polymer component is often grafted using common polymerization reactions, the nanoclay component is usually surface modified by surfactant treatment to improve compatibility. In the present study, the polymer ethylene vinyl alcohol and a nanoclay filler based on natural bentonite are both surface modified by different silanes, 3‐glycidoxypropyltrimethoxysilane and methacryloxymethyltrimethoxysilane and their interfacial properties are investigated by inverse gas chromatography. The silane‐modified samples had improved interfacial properties as reflected by a significant increase in dispersive and specific surface energies. Lewis acidities were determined using chloroform and 1,4‐dioxane as polar probes and showed a good match between polymer and nanofiller interfaces. Lewis acidity was generally lower after silane‐modification. Silanization yielded increased thermal stability of the treated samples. Thus, silanization led to improved compatibility and enhanced thermal stability which facilitates further processing. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41227.
Orographic disturbances of surface winds over the shelf waters adjacent to South Georgia
Authors: Hosking J. Scott , Bannister Daniel , Orr Andrew , King John , Young Emma , Phillips Tony 
Published: July 2014

AbstractThis study seeks to quantify the influence of South Georgia's orography on regional surface winds. A typical case study characterized by large‐scale westerly winds is analysed using a high‐resolution setup (3.3 km) of the Weather Research and Forecasting (WRF) regional model. The simulation produces significant fine‐scale spatial variability which is in agreement with satellite‐derived winds. The model simulation indicates that these orography‐driven wind disturbances are responsible for strong wind stress curl and enhanced heat flux over the shelf waters surrounding South Georgia. Such surface forcing is entirely absent from the reanalysis, highlighting the need to use high‐resolution forcing in regional ocean model simulations.
Molecular cloning, relative expression, and structural analysis of pattern recognition molecule β‐glucan binding protein from mangrove crabEpisesarma tetragonum
Authors: Sivakamavalli Jeyachandran , Selvaraj Chandrabose , Singh Sanjeev Kumar , Vaseeharan Baskaralingam 
Published: July 2014

AbstractA full‐length cDNA of a β‐glucan binding protein (β‐GBP) gene was identified from the mangrove crabEpisesarma tetragonum. The open reading frame of theE. tetragonumβ‐GBP (Epteβ‐GBP) is 1,167 bp long, encoding a polypeptide of 389 amino acids. The deduced amino acidsequence of Epte β‐GBPgene has conserved a potential recognition motif for β‐1,3 linkages of polysaccharides and putative RGD (Arg–Gly–Asp) cell adhesion sites. Phylogenetic analysis of theEpte β‐GBPgene showed the similarity with β‐GBPs of other crustaceans and arthropods. Quantitative RT‐PCR results showed the upregulation ofEpte β‐GBPgene expression inE. tetragonumhemocytes following a 12‐H challenge in response to β‐glucan (β‐G).Epteβ‐GBP was involved in the regulation and activation of the prophenoloxidase cascade. A three‐dimensional structure of activeEpteβ‐GBP was modeled by homology modeling and refined with molecular dynamics simulations. A structural aspect of the protein is discussed based on experimental and theoretical results obtained.
Split Ssp DnaB mini‐intein‐mediated production of recombinant human glucagon‐like peptide‐1/7‐36
Authors: Jiang Aiqin , Jin Wenbo , Zhao Feng , Tang Yanchun , Sun Ziyong , Liu Jian‐Ning 
Published: July 2014

AbstractGlucagon‐like peptide‐1 (GLP‐1) plays an important role in the regulation of postprandial insulin release. Here, we used the split DnaB mini‐intein system to produce recombinant human GLP‐1/7‐36 (rhGLP‐1) in Escherichia coli. The C‐terminal domain of DnaB mini‐intein (IntC) was genetically fused at the N‐terminus of rhGLP‐1 to produce IntC–GLP‐1. IntC–GLP‐1 and N‐terminal domain of DnaB mini‐intein (IntN) protein were prepared in a denatured buffer of pH 8.0. IntC–GLP‐1 was diluted 1:8 into the phosphate buffer of pH 6.6. IntN was added into the diluted solution of IntC–GLP‐1 at the molar ratio of 1:2. Then, rhGLP‐1 was released from IntC–GLP‐1 via inducible C‐terminal peptide‐bond cleavage by shifting pH from 8.0 to 6.6 at 25 °C for 24‐H incubation. Then, the supernatant was applied to a Ni‐Sepharose column, and the pass through fraction was collected. About 5.34 mg of rhGLP‐1 with the purity of 97% was obtained from 1 L of culture medium. Mass spectrometry showed the molecular weight of 3,300.45 Da, which was equal to the theoretical value of GLP‐1/7‐36. The glucose‐lowering activity of rhGLP‐1 was confirmed by the glucose tolerance test in mice. In conclusion, the reported method was an efficient strategy to produce rhGLP‐1 without using enzyme or chemical reagents, which could also be used for other similar peptides.
Dietary folate intake levels in rural women immediately before pregnancy in Northern China
Authors: Meng Qinqin , Zhang Le , Liu Jufen , Li Zhiwen , Jin Lei , Zhang Yali , Wang Linlin , Ren Aiguo 
Published: July 2014

BackgroundThe study aims to assess dietary folate levels and food sources in women immediately before pregnancy in a rural area of northern China associated with a high prevalence of neural tube defects.MethodsInformation was collected by face‐to‐face interviews with women who sought premarital healthcare and planned to become pregnant within the next 12 months from November 2009 through December 2012. Information regarding food consumption was obtained by means of 24‐hr dietary recall. Folate values were assigned to foods according to the China Food Composition 2004. Factors associated with dietary folate intake were analyzed by multiple linear regression.ResultsMean (± standard deviation) and median (interquartile range) daily folate intake levels were 114.3 ± 59.7 and 102.8 (69.3–146.8) μg/day, respectively. Over 99% of the subjects had an intake level below 320 μg/day, the estimated average requirement for nonpregnant women. Only 1% and 7% of the women consumed 75% and 50%, respectively, of the recommended daily folate intake of 400 μg for nonpregnant women. Over 80% of total folate consumption came from cereals, vegetables, and tubers, whereas fruit consumption was severely lacking. Underweight women, farmers, women enrolled during the winter, and women with access to fewer food types or daily meals were more likely to exhibit low folate intake levels.ConclusionDietary folate intake among study participants was far below the recommended intake level. Folic acid fortification of cereals is advised to raise folate intake in rural Chinese women planning to become pregnant. Birth Defects Research (Part A) 103:27–36, 2015. © 2014 Wiley Periodicals, Inc.
A new rhodamine‐based fluorescent chemodosimeter for mercuric ions in water media
Authors: Quy Phan Tu , Hien Nguyen Khoa , Bao Nguyen Chi , Nhan Doan Thanh , Khanh Dang Van , Nhung Nguyen Thi Ai , Tung Truong Quy , Luyen Nguyen Dinh , Quang Duong Tuan 
Published: July 2014

AbstractA new rhodamine–ethylenediamine–nitrothiourea conjugate (RT) was synthesized and its sensing property as a fluorescent chemodosimeter toward metal ions was explored in water media. Analytical results from absorption and fluorescence spectra revealed that the addition of Hg2+ ions to the aqueous solution of the chemodosimeter RT caused a distinct fluorescence OFF–ON response with a remarkable visual color change from colorless to pink; however, no clear spectral and color changes were observed from other metal ions including: Zn2+, Cu2+, Cd2+, Pb2+, Ag+, Fe2+, Cr3+, Co3+, Ni2+, Ca2+, Mg2+, K+ and Na+. The sensing results and the molecular structure suggested that a Hg2+‐induced a desulfurization reaction and cyclic guanylation of the thiourea moiety followed by ring‐opening of the rhodamine spirolactam in RT are responsible for a distinct fluorescence turn‐on signal, indicating that RT is a remarkably sensitive and selective chemodosimeter for Hg2+ ions in aqueous solution. Hg2+ within a concentration range from 0.1 to 25 μM can be determined using RT as a chemodosimeter and a detection limit of 0.04 μM is achieved. Copyright © 2014 John Wiley & Sons, Ltd.
Development of high throughput screening assays and pilot screen for inhibitors of metalloproteases meprin α and β
Authors: Madoux Franck , Tredup Claudia , Spicer Timothy P. , Scampavia Louis , Chase Peter S. , Hodder Peter S. , Fields Gregg B. , Becker‐Pauly Christoph , Minond Dmitriy 
Published: July 2014

ABSTRACTZinc metalloproteinases meprin α and meprin β are implicated in a variety of diseases, such as fibrosis, inflammation and neurodegeneration, however, there are no selective small molecule inhibitors that would allow to study their role in these processes. To address this lack of molecular tools, we have developed high throughput screening assays to enable discovery of inhibitors of both meprin α and meprin β and screened a collection of well characterized pharmaceutical agents (library of pharmaceutically active compounds, n = 1,280 compounds). Two compounds (PPNDS, NF449) confirmed their activity and selectivity for meprin β. Kinetic studies revealed competitive (PPNDS) and mixed competitive/noncompetitive (NF449) inhibition mechanisms suggesting that binding occurs in meprin β active site. Both PPNDS and NF449 exhibited low nanomolar IC50 and Ki values making them the most potent and selective inhibitors of meprin β reported to the date. These results demonstrate the ability of meprin α and β assays to identify selective compounds and discard artifacts of primary screening. © 2014 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 396–406, 2014.
Effect of anion structures on cholinium ionic liquids pretreatment of rice straw and the subsequent enzymatic hydrolysis
Authors: Hou Xue‐Dan , Xu Jie , Li Ning , Zong Min‐Hua 
Published: July 2014

ABSTRACTIn this work, 28 cholinium ionic liquids (ILs), most of which are good solvents for dissolving lignin, were used for rice straw pretreatment to improve subsequent enzymatic hydrolysis. The anion exerted a significant effect on the pretreatment effectiveness of the IL as well as the subsequent enzymatic hydrolysis efficiency of rice straw residues. The presence of the basic group(s) in the anion significantly enhanced the IL pretreatment effectiveness, while the carboxyl, hydroxyl and aromatic groups had a negative impact on IL delignification. Except for amino acid‐based ILs, the delignification abilities of the ILs are linearly and positively correlated with the pKa values of the conjugate acids of the anions. Of the ILs tested, amino acid‐based ILs, especially basic amino acid‐based ILs, are the most effective pretreatment solvents. Satisfactory reducing sugar yields (81% for glucose and 26% for xylose) were obtained in the enzymatic hydrolysis of rice straw pretreated by cholinium argininate ([Ch][Arg]) under a pretty mild pretreatment severity (60°C, 6 h). The results presented in this work may be useful for rational design of novel and green ILs for delignification of lignocellulose. Biotechnol. Bioeng. 2015;112: 65–73. © 2014 Wiley Periodicals, Inc.
A medium‐throughput analysis of signaling pathways involved in early stages of stem cell reprogramming
Authors: Fritz Ashley L. , Mao Sunnie R. , West Mary G. , Schaffer David V. 
Published: July 2014

ABSTRACTThe induction of pluripotency from adult cells has enormous potential in regenerative medicine. While initial efforts to study mechanisms and improve efficiency of induced pluripotent stem cell (iPSC) reprogramming focused on the direct roles of transcriptional regulators, increasing evidence indicates that cellular signal transduction pathways can modulate this process. Here, we present a medium‐throughput system to study the effect of signaling pathways on the early stages of reprogramming. We generated a set of lentiviral vectors encoding 38 genes that upregulate or downregulate major signal transduction pathways and quantified each signaling factor's effect on reprogramming. This approach confirmed the role of several factors previously implicated in reprogramming, as well as identified several GTPases‐factors that to date have not been largely studied in reprogramming‐that improve or hinder iPSC reprogramming. In addition, this methodology is useful in determining new targets for enhancing pluripotency reprogramming, lineage reprogramming, and/or cell differentiation. Biotechnol. Bioeng. 2015;112: 209–219. © 2014 Wiley Periodicals, Inc.
Assembly and multiple gene expression of thermophilic enzymes in Escherichia coli for in vitro metabolic engineering
Authors: Ninh Pham Huynh , Honda Kohsuke , Sakai Takaaki , Okano Kenji , Ohtake Hisao 
Published: July 2014

ABSTRACTIn vitro reconstitution of an artificial metabolic pathway is an emerging approach for the biocatalytic production of industrial chemicals. However, several enzymes have to be separately prepared (and purified) for the construction of an in vitro metabolic pathway, thereby limiting the practical applicability of this approach. In this study, genes encoding the nine thermophilic enzymes involved in a non‐ATP‐forming chimeric glycolytic pathway were assembled in an artificial operon and co‐expressed in a single recombinant Escherichia coli strain. Gene expression levels of the thermophilic enzymes were controlled by their sequential order in the artificial operon. The specific activities of the recombinant enzymes in the cell‐free extract of the multiple‐gene‐expression E. coli were 5.0–1,370 times higher than those in an enzyme cocktail prepared from a mixture of single‐gene‐expression strains, in each of which a single one of the nine thermophilic enzymes was overproduced. Heat treatment of a crude extract of the multiple‐gene‐expression cells led to the denaturation of indigenous proteins and one‐step preparation of an in vitro synthetic pathway comprising only a limited number of thermotolerant enzymes. Coupling this in vitro pathway with other thermophilic enzymes including the H2O‐forming NADH oxidase or the malate/lactate dehydrogenase facilitated one‐pot conversion of glucose to pyruvate or lactate, respectively. Biotechnol. Bioeng. 2015;112: 189–196. © 2014 Wiley Periodicals, Inc.