bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biobased thermosetting resins composed of L‐lysine methyl ester and bismaleimide
Authors: Ozawa Yuta , Shibata Mitsuhiro 
Published: January 2014

ABSTRACTLysine methyl ester (LME), which was generated in situ by the reaction of lysine methyl ester dihydrochloride and triethylamine in dimethyl sulfoxide (DMSO), was prepolymerized with 4,4′‐bismaleimidodiphenylmethane (BMI) at 80°C for 2 h in DMSO. Then, the formed prepolymer was precipitated in water. The obtained LME/BMI prepolymers with molar ratios of 2:2, 2:3, and 2:4 were compression‐molded at a final temperature of 230°C for 2 h to produce cured lysine methyl ester/4,4′‐bismaleimidodiphenylmethane resins (cLBs; cLB22, cLB23, and cLB24, respectively). Fourier transform infrared (FTIR) analyses revealed that the Michael addition reaction of amino groups to the CC bonds of the maleimide group occurred in addition to the homopolymerization of the maleimide group. The glass‐transition temperature (Tg) and 5% weight loss temperature (T5) of the cured resin increased with increasing BMI feed content, and cLB24 showed the highest Tg (343°C) and T5 (389°C). The flexural strengths (131–150 MPa) and moduli (3.0–3.6 GPa) of the cLBs were comparable to those of the conventionally cured resins of BMI and 4,4′‐diaminodiphenylmethane. Field emission scanning electron microscopy analysis revealed that there was no phase separation for all of the cured resins. Although cLB23 and cLB24 were not biodegradable, cLB22 had a biodegradability of 8.5% after 30 days in an aerobic aqueous medium containing activated sludge. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40379.
Carbon‐Coated LiTi2(PO4)3: An Ideal Insertion Host for Lithium‐Ion and Sodium‐Ion Batteries
Authors: Aravindan Vanchiappan , Ling Wong Chui , Hartung Steffen , Bucher Nicolas , Madhavi Srinivasan 
Published: January 2014

AbstractWe report the extraordinary performance of carbon‐coated sodium super ion conductor (NASICON)‐type LiTi2(PO4)3 as an ideal host matrix for reversible insertion of both Li and Na ions. The NASICON‐type compound was prepared by means of a Pechini‐type polymerizable complex method and was subsequently carbon coated. Several characterization techniques such as XRD, thermogravimetric analysis (TGA), field‐emission (FE) SEM, TEM, and Raman analysis were used to study the physicochemical properties. Both guest species underwent a two‐phase insertion mechanism during the charge/discharge process that was clearly evidenced from galvanostatic and cyclic voltammetric studies. Unlike that of Li (≈1.5 moles of Li), Na insertion exhibits better reversibility (≈1.59 moles of Na) while experiencing a slightly higher capacity fade (≈8 % higher than Li) and polarization (780 mV) than Li. However, excellent rate capability profiles were noted for Na insertion relative to its counterpart Li. Overall, the Na insertion properties were found to be superior relative to Li insertion, which makes carbon‐coated NASICON‐type LiTi2(PO4)3 hosts attractive for the development of next‐generation batteries.
Association between maternal COMT gene polymorphisms and fetal neural tube defects risk in a Chinese population
Authors: Liu Jufen , Wang Linlin , Fu Yunting , Li Zhiwen , Zhang Yali , Zhang Le , Jin Lei , Ye Rongwei , Ren Aiguo 
Published: January 2014

Background:Maternal tea consumption was reported to increase the risk of fetal neural tube defects (NTDs). Catechol‐O‐methyltransferase (COMT) may be involved in the metabolism of polyphenolic methylation of tea, thus influence the risk of fetal NTDs. Methods: A total of 576 fetuses or newborns with NTDs and 594 healthy newborns were included in the case–control study. Information on maternal tea consumption, sociodemographic characteristics, reproductive history, and related behavior was collected through face‐to‐face interviews. Maternal blood samples were collected to examine polymorphisms in COMT, and the possible interaction of COMT and tea consumption was analyzed. RESULTS: After controlling for potential confounders, homozygotes of rs737865 showed an elevated risk for total NTDs (odds ratio [OR] = 2.04, 95% confidence interval [CI], 1.24–3.35) and for the anencephaly subtype (OR = 1.99, 95% CI, 1.17–3.39). The CC genotype of rs4633 was positively associated with the overall risk of NTDs (OR = 3.66, 95% CI, 1.05–12.83). Heterozygotes for rs4680 were associated with a decreased risk of spina bifida (OR = 0.71, 95% CI, 0.51–0.98). The COMT rs4680 A allele was negatively related with the risk of spina bifida, with adjusted OR = 0.64 (95% CI, 0.45–0.89). An interaction between tea consumption (1 to 2 cups/day) and the rs4680AA/AG genotype was found in the spina bifida subtype (Pinteraction = .08). Conclusion: Several COMT variants were associated with elevated risk of NTDs in a Chinese population. Maternal tea consumption may be associated with an increased risk for fetal NTDs in genetically susceptible subgroups. Birth Defects Research (Part A) 100:22–29, 2014. © 2013 Wiley Periodicals, Inc.
Probing Bacterial Uptake of Glycosylated Ciprofloxacin Conjugates
Authors: Milner Stephen J. , Carrick Christopher T. , Kerr Kevin G. , Snelling Anna M. , Thomas Gavin H. , Duhme‐Klair Anne‐Kathrin , Routledge Anne 
Published: January 2014

AbstractMono‐ and disaccharide‐functionalised conjugates of the fluoroquinolone antibiotic ciprofloxacin have been synthesised and used as chemical probes of the bacterial uptake of glycosylated ciprofloxacin. Their antimicrobial activities against a panel of clinically relevant bacteria were determined: the ability of these conjugates to inhibit their target DNA gyrase and to be transported into the bacteria was assessed by using in vivo and in vitro assays. The data suggest a lack of active uptake through sugar transporters and that although the addition of monosaccharides is compatible with the inhibition of DNA gyrase, the addition of a disaccharide results in a significant decrease in antimicrobial activity.
Red Fluorescent Turn‐On Ligands for Imaging and Quantifying G Protein‐Coupled Receptors in Living Cells
Authors: Karpenko Iuliia A. , Kreder Rémy , Valencia Christel , Villa Pascal , Mendre Christiane , Mouillac Bernard , Mély Yves , Hibert Marcel , Bonnet Dominique , Klymchenko Andrey S. 
Published: January 2014

AbstractClassical fluorescence‐based approaches to monitor ligand–protein interactions are generally hampered by the background signal of unbound ligand, which must be removed by tedious washing steps. To overcome this major limitation, we report here the first red fluorescent turn‐on probes for a G protein‐coupled receptor (oxytocin receptor) at the surface of living cells. The peptide ligand carbetocin was conjugated to one of the best solvatochromic (fluorogenic) dyes, Nile Red, which turns on emission when reaching the hydrophobic environment of the receptor. We showed that the incorporation of hydrophilic octa(ethylene glycol) linker between the pharmacophore and the dye minimized nonspecific interaction of the probe with serum proteins and lipid membranes, thus ensuring receptor‐specific turn‐on response. The new ligand was successfully applied for background‐free imaging and quantification of oxytocin receptors in living cells.
Cellular and molecular stimulation of adipose‐derived stem cells under hypoxia
Authors: Kang Sangjin , Kim Soo‐Min , Sung Jong‐Hyuk 
Published: January 2014

AbstractCultivation under hypoxia has beneficial effects on adipose‐derived stem cells (ASCs). Despite a history of extensive research on the responses of ASCs to hypoxia, investigations have focused on functional alterations of ASCs. Therefore, we provide novel insight in this review into the cellular and molecular changes that occur in ASCs under hypoxic conditions. Hypoxia increases the proliferation and migration of ASCs by the generation of reactive oxygen species (ROS) and downstream phosphorylation of platelet‐derived growth factor receptor‐beta, ERK1/2, and Akt. Chronically, activation of these signaling pathways upregulates miR‐210 via phosphorylation of NF‐κB and Elk1. Protein tyrosine phosphatase, non‐receptor type 2 (PTPN2) is a direct miR‐210 target, and downregulation of PTPN2 mediates the proliferation and migration of ASCs during hypoxia. In addition, the paracrine effect of ASCs is enhanced under hypoxic conditions, irrespective of whether ROS are generated. Hypoxic preconditioning stabilizes hypoxia inducible factor‐1α under hypoxic conditions and increases secretion of vascular endothelial growth factor, thereby improving the regenerative potential of ASCs. Therefore, understanding the cellular and molecular changes that occur during hypoxia is highly relevant for the development of novel ASC therapies.
Immobilized Hydroxynitrile Lyase: A Comparative Study of Recyclability
Authors: Torrelo Guzman , van Midden Nelleke , Stloukal Radek , Hanefeld Ulf 
Published: January 2014

AbstractHydroxynitrile lyase from cassava, Manihot esculenta, (MeHNL) catalyzes the formation of (S)‐cyanohydrins from HCN and aldehydes or ketones. Four differently immobilized MeHNLs were prepared: by noncovalent immobilization (celite R‐633), covalent immobilization (cross‐linked enzyme aggregates, CLEA), encapsulation [in a poly(vinyl alcohol) hydrogel Lentikats] and a combination of the above, an unusual immobilization, CLEA encapsulated in a poly(vinyl alcohol) hydrogel. A comparative study of the recyclability of each immobilized MeHNL was performed. Particular attention was paid to the stability and activity of the new immobilized MeHNL–CLEA–Lentikats and to the minimum enzyme loading required to achieve high yields and enantiomeric excesses. MeHNL–CLEA stability was slightly improved by encapsulation into Lentikats and good recyclability rates at low enzyme loading were obtained. However, MeHNL immobilized on celite R‐633 exhibited the best recyclability, giving >95 % conversion and an enantiomeric excess of 99 % during 12 cycles.
Electrochemical‐ and Fluorescent‐Mediated Signal Amplifications for Rapid Detection of Low‐Abundance Circulating Tumor Cells on a Paper‐Based Microfluidic Immunodevice
Authors: Wu Yafeng , Xue Peng , Hui Kam M. , Kang Yuejun 
Published: January 2014

AbstractThe design of a novel paper‐based microfluidic immunodevice with combined electrochemical‐ and fluorescent‐mediated signal amplifications for the highly specific and ultrasensitive point‐of‐care detection of rare circulating tumor cells is reported.
Ordered Hybrids from Template‐Free Organosilane Self‐Assembly
Authors: Chemtob Abraham , Ni Lingli , Croutxé‐Barghorn Céline , Boury Bruno 
Published: January 2014

AbstractDespite considerable achievements over the last two decades, nonporous organic–inorganic hybrid materials are mostly amorphous, especially in the absence of solvothermal processes. The organosilane self‐assembly approach is one of the few opportunities for creating a regular assembly of organic and inorganic moieties. Additionally, well‐established organosilicon chemistry enables the introduction of numerous organic functionalities. The synthesis of periodically ordered hybrids relies on mono‐, bis‐, or multisilylated organosilane building blocks self‐assembling into hybrid mesostructures or superstructures, subsequently cross‐linked by siloxane Si‐O‐Si condensation. The general synthesis procedure is template‐free and one‐step. However, three concurrent processes underlie the generation of self‐organized hybrid networks: thermodynamics of amphiphilic aggregation, dynamic self‐assembly, and kinetically controlled sol–gel chemistry. Hence, the set of experimental conditions and the precursor structure are of paramount importance in achieving long‐range order. Since the first developments in the mid‐1990s, the subject has seen considerable progress leading to many innovative advanced nanomaterials providing promising applications in membranes, pollutant remediation, catalysis, conductive coatings, and optoelectronics. This work reviews, comprehensively, the primary evolution of this expanding field of research.
Cerium‐Based M4L4 Tetrahedra as Molecular Flasks for Selective Reaction Prompting and Luminescent Reaction Tracing
Authors: Jiao Yang , Wang Jian , Wu Pengyan , Zhao Liang , He Cheng , Zhang Jing , Duan Chunying 
Published: January 2014

AbstractThe application of metal–organic polyhedra as “molecular flasks” has precipitated a surge of interest in the reactivity and property of molecules within well‐defined spaces. Inspired by the structures of the natural enzymatic pockets, three metal–organic neutral molecular tetrahedral, Ce‐TTS, Ce‐TNS and Ce‐TBS (H6TTS: N′,N′′,N′′′‐nitrilotris‐4,4′,4′′‐(2‐hydroxybenzylidene)‐benzohydrazide; H6TNS: N′,N′′,N′′′‐nitrilotris‐6,6′,6′′‐(2‐hydroxybenzylidene)‐2‐naphthohydrazide; H6TBS: 1,3,5‐ phenyltris ‐4,4′,4′′‐(2‐hydroxybenzylidene)benzohydrazide), which exhibit different size of the edges and cavities, were achieved through self‐assembly by incorporating robust amide‐containing tridentate chelating sites into the fragments of the ligands. They acted as molecular flasks to prompt the cyanosilylation of aldehydes with excellent selectivity towards the substrates size. The amide groups worked as trigger sites and catalytic driven forces to achieve efficient guest interactions, enforcing the substrates proximity within the cavity. Experiments on catalysts with the different cavity radii and substrates with the different molecular size demonstrated that the catalytic performance exhibited enzymatical catalytic mechanism and occurred in the molecular flask. These amides were also able to amplify guest‐bonding events into the measurable outputs for the detection of concentration variations of the substrates, providing the possibility for metal–organic hosts to work as smart molecular flasks for the luminescent tracing of catalytic reactions.
Alkylation of Terminal Alkynes with Transient σ‐Alkylpalladium(II) Complexes: A Carboalkynylation Route to Alkyl‐Substituted Alkynes
Authors: Zhou Ming‐Bo , Huang Xiao‐Cheng , Liu Yan‐Yun , Song Ren‐Jie , Li Jin‐Heng 
Published: January 2014

AbstractA mild and general alkylation of terminal alkynes with transient σ‐alkylpalladium(II) complexes for assembling alkyl‐substituted alkynes is described. This method represents a new way to the use of transient σ‐alkylpalladium(II) complexes in organic synthesis through 1,2‐carboalkynylation of alkenes.
Regeneration of a Conjugated sp2 Graphene System through Selective Defunctionalization of Epoxides by Using a Proven Synthetic Chemistry Mechanism
Authors: Chua Chun Kiang , Pumera Martin 
Published: January 2014

AbstractGraphene is a promising material capable of driving technological advancement. It is, however, a challenge to obtain pristine graphene in large quantities given the limitation of current synthetic methods. Among the numerous methods available, the chemical approach provides an optimistic outlook and has garnered much interest within the graphene community as a potential alternative. One of the most crucial steps of the chemical approach is the chemical reduction of graphene oxide as this dictates the final quality of the graphene sheets. In recent years, much of the focus has shifted to the usage of established reducing agents or oxygen removal reagents, frequently applied in organic chemistry, onto a graphene oxide platform. Herein, the selective removal of epoxide groups and subsequent regeneration of disrupted conjugated sp2 system is highlighted, based on the synergistic effect of indium and indium(I) chloride. The morphological, structural, and electrical properties of the resulting graphene were fully characterized with X‐ray photoelectron, Fourier transform IR, solid‐state 13C NMR, and Raman spectroscopy; thermogravimetric analysis; scanning electron microscopy; and conductivity measurements. The as‐prepared graphene showed a tenfold increase in conductivity against conventional graphene treated with hydrazine reducing agent and demonstrated a high dispersion stability in ethanol. Moreover, the selective defunctionalization of the epoxide groups provides opportunities for potential tailoring of graphene properties for prospective applications.
Novozym 435‐Catalyzed Syntheses of Polyesters and Polyamides of Medicinal and Industrial Relevance
Authors: Khan Abdullah , Sharma Sunil K. , Kumar Amit , Watterson Arthur C. , Kumar Jayant , Parmar Virinder S. 
Published: January 2014

AbstractThe adverse impact of chemical and biochemical waste on the environment and human health poses a serious challenge in today’s World. The best way to address these challenges is to reduce the waste by developing more efficient processes and technologies, based on the principles of “green chemistry”. Some of these synthetic approaches involving the chemoenzymatic synthetic methodologies are discussed herein. These lead to the formation of unique nanomaterials with diverse applications, such as drugs/gene delivery systems, flame retardant materials, conducting polymers, controlled release systems, diagnostic agents, and polymeric electrolytes for nanocrystalline solar cells.
Cleavage of CO Bonds in Lignin Model Compounds Catalyzed by Methyldioxorhenium in Homogeneous Phase
Authors: Harms Reentje G. , Markovits Iulius I. E. , Drees Markus , Herrmann h.c. mult. Wolfgang A. , Cokoja Mirza , Kühn Fritz E. 
Published: January 2014

AbstractMethyldioxorhenium (MDO)‐catalyzed CO bond cleavage of a variety of lignin β‐O‐4‐model compounds yields phenolic and aldehydic compounds in homogeneous phase under mild reaction conditions. MDO is in situ generated by reduction of methyltrioxorhenium (MTO) and is remarkably stable under the applied reaction conditions allowing its reuse for least five times without significant activity loss. Based on the observed and isolated intermediates, 17 O‐ and 2 H‐isotope labeling experiments, DFT calculations, and several spectroscopic studies, a reaction mechanism is proposed.
Biosourced Nitrogen‐Doped Microcellular Carbon Monoliths
Authors: Brun Nicolas , Osiceanu Petre , Titirici Magdalena M. 
Published: January 2014

AbstractAn original approach based on the hydrothermal carbonization of nitrogen‐containing biomass derivatives within the continuous phase of a direct concentrated emulsion is reported for the synthesis of nitrogen‐doped microcellular carbon monoliths. These biosourced foams show promising performances as intrinsic electrocatalysts in the oxygen reduction reaction. Preliminary catalytic properties of powdered versus monolithic samples are discussed and suggest interesting prospects for their introduction within electrochemical devices.
The receptor‐like kinases GSO1 and GSO2 together regulate root growth in arabidopsis through control of cell division and cell fate specification
Authors: Racolta Adriana , Bryan Anthony C. , Tax Frans E. 
Published: January 2014

ABSTRACTCOVER PHOTOGRAPH: Confocal image of a median optical section through a heart stage Arabidopsis embryo expressing the epidermalmarker pATML1:: HTA6‐GFP and counterstained with propidium iodide. From The receptor‐like kinases GSO1 and GSO2 together regulate root growth in Arabidopsis through control of cell division and cell fate specification; Racolta et al, Developmental Dynamics 243:257–278.
Increasing pCO2 correlates with low concentrations of intracellular dimethylsulfoniopropionate in the sea anemone Anemonia viridis
Authors: Borell Esther M. , Steinke Michael , Horwitz Rael , Fine Maoz 
Published: January 2014

AbstractMarine anthozoans maintain a mutualistic symbiosis with dinoflagellates that are prolific producers of the algal secondary metabolite dimethylsulfoniopropionate (DMSP), the precursor of the climate‐cooling trace gas dimethyl sulfide (DMS). Surprisingly, little is known about the physiological role of DMSP in anthozoans and the environmental factors that regulate its production. Here, we assessed the potential functional role of DMSP as an antioxidant and determined how future increases in seawater pCO2 may affect DMSP concentrations in the anemone Anemonia viridis along a natural pCO2 gradient at the island of Vulcano, Italy. There was no significant difference in zooxanthellae genotype and characteristics (density of zooxanthellae, and chlorophyll a) as well as protein concentrations between anemones from three stations along the gradient, V1 (3232 μatm CO2), V2 (682 μatm) and control (463 μatm), which indicated that A. viridis can acclimate to various seawater pCO2. In contrast, DMSP concentrations in anemones from stations V1 (33.23 ± 8.30 fmol cell−1) and V2 (34.78 ± 8.69 fmol cell−1) were about 35% lower than concentrations in tentacles from the control station (51.85 ± 12.96 fmol cell−1). Furthermore, low tissue concentrations of DMSP coincided with low activities of the antioxidant enzyme superoxide dismutase (SOD). Superoxide dismutase activity for both host (7.84 ± 1.37 U·mg−1 protein) and zooxanthellae (2.84 ± 0.41 U·mg−1 protein) at V1 was 40% lower than at the control station (host: 13.19 ± 1.42; zooxanthellae: 4.72 ± 0.57 U·mg−1 protein). Our results provide insight into coastal DMSP production under predicted environmental change and support the function of DMSP as an antioxidant in symbiotic anthozoans.
Phosphane‐Ligated Ionic Palladium Complexes: Synthesis, Characterization and Application as Efficient and Reusable Precatalysts for the Homogeneous Carbonylative Sonogashira Reaction under CuI‐Free Conditions
Authors: Zhang Jing , Wang Yongyong , Zhao Xiaoli , Liu Ye 
Published: January 2014

AbstractThe stable ionic PdII complexes 1A–4A were synthesized through the complexation of PdCl2(MeCN)2 with the phosphane‐functionalized ionic liquids (FILs) 1–4 with π‐acceptor character. Single‐crystal X‐ray diffraction analyses showed that 1A–4A were all composed of PdII‐centred square‐planar cations and triflate (OTf–, CF3SO3–) counteranions. The complex cations in 1A–3A possessed structural similarity to trans‐PdCl2(PPh3)2. The cation in 4A was a new PdII‐centered planar complex ligated by the phosphane–carbon anion–carbene (PCC) pincer in a tripodal manner. The stabilities of 1A–4A were improved due to the intensive π‐backbonding interaction between the Pd and P atoms. When complexes 1A–4A were used as precatalysts for homogeneous carbonylative Sonogashira coupling of PhI with phenylacetylene free of CuI, 1A–3A exhibited excellent catalytic behaviour with a TON of up to 1700 at a CO pressure of 0.5 MPa and moderate temperature of 100 °C, whereas 4A exhibited poor activity towards the transformation of PhI due to the high stability of 4A. The recycling experiments of 3A in [Bpy]BF4 (as a solvent) indicated that 3A could be recycled for 5 runs with neither activity loss nor metal leaching into the organic phase. Complex 3A also proved to be a general precatalyst for the carbonylative Sonogashira couplings of a wide range of aryl iodides with phenylacetylene. The selectivity of the desired carbonylation product depended more on electronic effects than the steric effects of the substituents of the aryl iodides.