bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of bicyclic bis(γ‐butyrolactone) derivatives bearing sulfide moieties and their alternating copolymers with epoxide
Authors: Ohsawa Sousuke , Morino Kazuhide , Sudo Atsushi , Endo Takeshi 
Published: August 2012

AbstractA series of bicyclic bis(γ‐butyrolactone)s (BBL) bearing sulfide moiety 2 were readily synthesized from a precursor BBL bearing isopropenyl group 1. This efficient and versatile synthesis of 2 was achieved by a highly reliable radical addition reaction of thiols to the C‐C double bond in the isopropenyl group 2 underwent anionic copolymerization with glycidyl phenyl ether in a 1:1 alternating manner to give a series of the corresponding polyester 3, of which side chains inherited the sulfide group from 2. The glass transition temperatures (Tg) of 3 showed clear dependence on the flexibility of the sulfide side chains. The scope of this copolymerization system was further expanded by synthesizing a bifunctional BBL 4 from 1 with using hexanedithiol and performing its copolymerization with bisphenol A diglycidyl ether 5. The copolymerization gave the corresponding networked polymer in high yield. During the copolymerization, the volume expanding nature of the double ring‐opening reaction of 4 contributed to the efficient compensation of the intrinsic volume shrinkage of the ring‐opening of epoxide to achieve a shrinkage‐free curing system. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Photoinitiated cationic polymerization of limonene 1,2‐oxide and α‐pinene oxide
Authors: Park Han Jin , Ryu Chang Y. , Crivello James V. 
Published: August 2012

AbstractLimonene 1,2‐oxide (LMO) and α‐pinene oxide (α‐PO) are two high reactivity biorenewable monomers that undergo facile photoinitiated cationic ring‐opening polymerizations using both diaryliodonium salt and triarylsufonium salt photoinitiators. Comparative studies showed that α‐PO is more reactive than LMO, and this is because it undergoes a simultaneous double ring‐opening reaction involving both the epoxide group and the cyclobutane ring. It was also observed that α‐PO also undergoes more undesirable side reactions than LMO. The greatest utility of these two monomers is projected to be as reactive diluents in crosslinking photocopolymerizations with multifunctional epoxide and oxetane monomers. Prototype copolymerization studies with several difunctional monomers showed that LMO and α‐PO were effective in increasing the reaction rates and shortening the induction periods of photopolymerizations of these monomers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Modeling Study on the Generation of Reactive Oxygen Species in Atmospheric Radio‐Frequency Helium–Oxygen Discharges
Authors: He Jin , Zhang Yuantao T 
Published: August 2012

AbstractAtmospheric radio‐frequency (rf) plasmas have attracted an increasing amount of attention due to its unparalleled capability for production of chemically reactive oxygen species (ROS). In this paper, we explore a one‐dimensional fluid model, incorporating 17 species and 65 key reactions, to investigate the generation mechanism of ROS in atmospheric He/O2 rf discharges. From the computational data the atomic oxygen density is almost linearly dependent on the power density and its largest value was observed at the oxygen admixture of 0.6% while altering the oxygen admixture at a constant power density, and an optimal oxygen admixture level of 0.3% is also found to produce the largest density of single delta oxygen (SDO) at a given power density.The dominant production and destruction reactions of ROS are also discussed based on the simulation results. magnified image
Engineering metal precipitate size distributions to enhance gettering in multicrystalline silicon
Authors: Hofstetter Jasmin , Fenning David P. , Lelièvre Jean‐François , del Cañizo Carlos , Buonassisi Tonio 
Published: August 2012

AbstractThe extraction of metal impurities during phosphorus diffusion gettering (PDG) is one of the crucial process steps when fabricating high‐efficiency solar cells using low‐cost, lower‐purity silicon wafers. In this work, we show that for a given metal concentration, the size and density of metal silicide precipitates strongly influences the gettering efficacy. Different precipitate size distributions can be already found in silicon wafers grown by different techniques. In our experiment, however, the as‐grown distribution of precipitated metals in multicrystalline Si sister wafers is engineered through different annealing treatments in order to control for the concentration and distribution of other defects. A high density of small precipitates is formed during a homogenization step, and a lower density of larger precipitates is formed during extended annealing at 740 °C. After PDG, homogenized samples show a decreased interstitial iron concentration compared to as‐grown and ripened samples, in agreement with simulations.
Optical transition energies in armchair‐edge graphene nanoribbons under uniaxial strain
Authors: Han Mei , Zhang Yong 
Published: August 2012

AbstractThe optical transition energies of armchair‐edge graphene nanoribbons (AGNRs) under uniaxial strain have been studied based on tight‐binding model including up to third‐nearest‐neighbor carbon–carbon interaction and edge distortion. Obtained results show that the optical transition energies of AGNRs are sensitive to the uniaxial strain. The variations of optical transition energies on the uniaxial strains are linear but not monotonic, displaying an “N” or an upside‐down “N” type feature. The mechanism underlying the strain effects on optical transition energies has been revealed. The obtained optical transition energies can be used to help evaluating the future experiments on optical properties of strained AGNRs.
Lead‐vacancy‐related hole centers in lead tungstate crystals
Authors: Laguta Valentin , Nikl Martin , Zazubovich Svetlana 
Published: August 2012

AbstractAfter UV irradiation of PbWO4 crystals at T > 140 K in the energy range around 4.05 eV, besides the thermally stimulated luminescence (TSL) peak at ≈193 K arising from electron {Pb+ − VO} centers, a TSL peak at about 225 K appears. We suggest that this ≈225 K TSL peak arises from the thermal destruction of non‐paramagnetic hole centers of the {VPb + 2h}‐type (two holes trapped at the oxygen ions in the vicinity of a single lead vacancy VPb). The recombination of thermally or optically released electrons with these hole centers at T > 140 K is accompanied with green G(II) emission peaking at about 2.5 eV. The processes of photo‐thermally stimulated creation of VPb‐related hole centers have been studied.
A neutron reflectometry study on silicon self‐diffusion at 900 °C
Authors: Hüger E. , Kube R. , Bracht H. , Stahn J. , Geue T. , Schmidt H. 
Published: August 2012

AbstractWe carried out experiments of self‐diffusion in single crystalline silicon at a temperature of 900 °C by a method that is based on neutron reflectometry in combination with 29Si/28Si isotope multilayers. The experimental reflectivity pattern shows artificial Bragg peaks due to isotope periodicity and is fitted by the program Parratt32. Diffusivities are calculated from the roughness parameter of the isotope interfaces. The results are compared to that one obtained from a simple analytical expression on the reduction of the Bragg peak. The results exhibit that both methods deliver identical diffusivities within error limits. The diffusivity of 4 × 10−22 m2 · s−1 does not depend on annealing time for diffusion on a length scale of 1–6 nm and is in good accordance to literature data, ranging between 1 and 10 × 10−22 m2 · s−1. The results demonstrate that the neutron reflectometry method is well suited to determine self‐diffusivities in single crystalline silicon at very short length scales.
Collaborative mapping of an earthquake‐damaged building via ground and aerial robots
Authors: Michael Nathan , Shen Shaojie , Mohta Kartik , Mulgaonkar Yash , Kumar Vijay , Nagatani Keiji , Okada Yoshito , Kiribayashi Seiga , Otake Kazuki , Yoshida Kazuya , Ohno Kazunori , Takeuchi Eijiro , Tadokoro Satoshi 
Published: August 2012

AbstractWe report recent results from field experiments conducted with a team of ground and aerial robots engaged in the collaborative mapping of an earthquake‐damaged building. The goal of the experimental exercise is the generation of three‐dimensional maps that capture the layout of a multifloor environment. The experiments took place in the top three floors of a structurally compromised building at Tohoku University in Sendai, Japan that was damaged during the 2011 Tohoku earthquake. We provide details of the approach to the collaborative mapping and report results from the experiments in the form of maps generated by the individual robots and as a team. We conclude by discussing observations from the experiments and future research topics. © 2012 Wiley Periodicals, Inc.
Fabrication of Novel Hierarchical Structured Fe3O4@LnPO4 (Ln=Eu, Tb, Er) Multifunctional Microspheres for Capturing and Labeling Phosphopeptides
Authors: Wang Zhi‐Gang , Cheng Gong , Liu Yan‐Lin , Zhang Ji‐Lin , Sun De‐Hui , Ni Jia‐Zuan 
Published: August 2012

AbstractNovel core–shell structured Fe3O4@LnPO4 (Ln=Eu, Tb, Er) multifunctional microspheres with a magnetic Fe3O4 core and a LnPO4 shell covered with spikes are synthesized for the first time through the combination of a homogeneous precipitation approach and an ion‐exchange process. Their potential for selective capture, rapid separation, and easy mass spectrometry (MS) labeling of the phosphopeptides from complex proteolytic digests are evaluated. These affinity microspheres can improve the specificity for capture of the phosphopeptides, realize fast magnetic separation, enhance the MS detection signals, and directly identify phosphopeptides through 80 Da mass loss in the mass spectra. The synthesis strategy could become a general and effective technique for similar core–shell hierarchical structures.
Strain Rate Sensitivity of Pre‐Strained AISI 301LN2B Metastable Austenitic Stainless Steel
Authors: Larour Patrick , Verleysen Patricia , Dahmen Kirsten , Bleck Wolfgang 
Published: August 2012

AbstractThe dynamic behavior of AISI 301LN2B (EN 1.4318) metastable austenitic steel grade has been investigated at 296 K by means of servohydraulic tensile and split Hopkinson bar testing in the strain rate range 0.005–1000 s−1. As delivered, as well as 10% uniaxial, biaxial, and plane strain pre‐strained conditions, without subsequent heat treatment have been tested. A negative strain rate sensitivity is observed in the low strain rate range between 10−4 and 1–10 s−1. Pre‐straining reduces the magnitude of the adiabatic tensile strength softening, especially in the plane strain condition with higher triaxility. The thermal activation related dynamic flow stress increase is not dependent on pre‐straining. The γ → α′ induced additional flow stress increase, however, is highly strain rate and pre‐straining sensitive. The amount of pre‐straining determines the overall ductility at fracture, and therefore the adiabatic temperature increase. The pre‐straining stress state influences the amount of α′‐martensite formed before dynamic testing, and consequently the maximum intensity of the TRIP induced flow stress increase by subsequent dynamic testing.
Synthesis, Structure, and Bonding Analysis of the Polar Intermetallic Phase Ca2Pt2Cd
Authors: Samal Saroj L. , Corbett John D. 
Published: August 2012

AbstractThe polar intermetallic phase Ca2Pt2Cd was discovered during explorations of the Ca‐Pt‐Cd system. The compound was synthesized by high temperature reactions, and its structure refined by single‐crystal X‐ray diffraction as orthorhombic, Immm, a = 4.4514(5), b = 5.8415(6), c = 8.5976(9) Å, Z = 2. The structure formally contains infinite, planar networks of [Pt2Cd]4– along the ab plane, which can be described as tessellation of six and four‐member rings of the anions, with cations stuffed between the anion layers. The infinite condensed platinum chains show a substantial long–short distortion of 0.52 Å, an appreciable difference between Ca2Pt2Cd (26 valence electrons) and the isotypic but regular Ca2Cu2Ga (29 VE). The relatively large cation proportion diminishes the usual dominance of polar (Pt–Cd) and 5d–5d (Pt–Pt) contributions to the total Hamilton populations.
The Prolific {ZR6}X12R and {ZR6}X10 Structure Types with Isolated Endohedrally Stabilized (Z) Rare‐Earth Metal (R) Cluster Halide (X) Complexes
Authors: Rustige Christian , Brühmann Matthias , Steinberg Simon , Meyer Eva , Daub Kathrin , Zimmermann Sina , Wolberg Marike , Mudring Anja‐Verena , Meyer Gerd 
Published: August 2012

AbstractComproportionation reactions of rare‐earth metal trihalides, RX3, with the respective R metal in the presence of a transition metal Z, preferably from group 8 through 10, yielded single crystals of 31 {ZR6}X12R and 22 {ZR6}X10 type compounds, in most cases for the first time, especially with R = Tb, Dy, Ho, and Er. These are compared with literature entries. The crystal structures are discussed for the equal‐atom pair {IrEr6}I12Er and {IrEr6}I10. In both cases, {IrEr6}Ii12Ia6 cluster complexes are connected via i‐i and i‐a/a‐i bridges, respectively, the {IrEr6} clusters are isolated. Band structure calculations were carried out on the LMTO‐ASA level for a number of {ZY6}X10 examples; the density of states (DOS) and Crystal Orbital Hamiltonian Populations (COHP) derived therefrom exhibit strong Z–Y and Y–X bonding interactions. Most profitable are X = I and endohedral elements of sixth period atoms, especially Z = Os, Ir.
Koordinationspolymere mit Tris(4‐carboxyphenyl)‐phosphanoxid als Ligand – Synthese, Kristallstrukturen und topologische Untersuchungen
Authors: Schmiedel Peter , Krautscheid Harald 
Published: August 2012

AbstractThe solvothermal reaction of MnCl2·4H2O or CoCl2·6H2O with tris(4‐carboxyphenyl)‐phosphine oxide (H3TPO), in DMF orDMA resulted in the four coordination polymers [M3(tpo)2(dmf)(H2O)2](1: M = Mn; 2: M = Co), (NMe2H2)[Mn3Cl(HCO2)(htpo)(tpo)(H2O)] (3) and (NMe2H2)[Mn3(tpo)2(OAc)] (4). Structural characterization by X‐ray crystallography revealed that 1–4 form 3‐periodical infinite networks; after synthesis solvent molecules occupy the framework pores. The topologies of the networks in 1, 2 and 3 are unprecedented in literature and are systematically characterized. Furthermore, these topologies could be derived from hexagonal close packing (1, 2) and cubic close packing (3), respectively.Compounds 1, 2 and 4 were synthesized as pure crystalline materials, their thermal behaviour was examined by TG/DTA measurements and temperature dependent PXRD. 1, 2 and 4 show remarkable thermal stability with decomposition temperatures between 450 and 500 °C. Temperature dependent PXRD measurements of compounds 1 and 2 reveal a structural transition at 260 °C, framework 4 loses its crystallinity at 210 °C.
GeCpbig2 [Cpbig = C5(CH2C6H4‐iPr)5]: A Flexible Sandwich Molecule
Authors: Naglav Dominik , Tobey Briac , Harder Sjoerd , Schnepf Andreas 
Published: August 2012

AbstractGeCpbig2 (1) [Cpbig = C5(CH2C6H4‐iPr)5] was synthesized by a reaction of KCpbig either with a GeCl solution or GeCl2 and was obtained as colorless crystals. The molecular structure of 1 was determined by X‐ray diffraction, showing that 1 features two pentahapto bonded Cpbig ligands in a bent configuration with a Cpbig‐Ge–Cpbig angle of 161°. Two out of ten benzyl substituents point towards the lone pair at the germanium atom so that two molecules fit perfectly together, leading to a dimeric arrangement of 1 within the solid state. Two polymorphs of 1 could be isolated, where 1 is oriented in a different way. As indicated by quantum chemical calculations, the open structure, where all benzyl substituents point away from the germanium atom is only disfavored by 21.6 kJ·mol–1. In the open structure a bent arrangement is still realized, giving access to the lone pair at the germanium atom for further applications, e.g. in coordination chemistry.
Self‐Intercalation and Vacancy‐Ordering in 6R‐CuxTa1+yS2 (x ≈ 0.23, y = 0, 0.06)
Authors: Ali Sk Imran , Mondal Swastik , Prathapa Siriyara Jagannatha , van Smaalen Sander , Zörb Steffen , Harbrecht Bernd 
Published: August 2012

AbstractThe eightfold 2a0×2b0×2c0 superstructures of 6R‐CuxTa1+yS2 are reported for crystal A with x = 0.237 and y = 0, and crystal B with x = 0.23 and y = 0.06. Compelling evidence is presented for the self‐intercalation of tantalum onto octahedral sites, based on the diffraction data and crystal chemical arguments. The eightfold superstructure is formed by partial vacancy ordering within planes of intercalated atoms, while the stacking of TaS2 layers remains that of the 6R polytype. Temperature‐dependent X‐ray diffraction experiments show that the superstructure exists between T = 14 K and at least 370 K. Intercalated atoms enter the compound at octahedral and tetrahedral sites in alternating Van der Waals gaps. Intercalation is inhomogeneous, with average occupancies varying between 0.11 for octahedral sites within one Van der Waals gap and 0.23 for the tetrahedral sites within another Van der Waals gap. It is proposed that partial vacancy ordering is governed by the principle of maximum separation between intercalated atoms.
Novel therapeutic target for cancer stem cells in hepatocellular carcinoma
Authors: Nagano Hiroaki , Ishii Hideshi , Marubashi Shigeru , Haraguchi Naotsugu , Eguchi Hidetoshi , Doki Yuichiro , Mori Masaki 
Published: August 2012

AbstractCancer is a disease of genetic and epigenetic alterations, which are emphasized as the central mechanisms of tumor progression in the multi‐stepwise model. Discovery of rare subpopulations of cancer stem cells (CSCs) has created a new focus in cancer research. The heterogeneity of tumors can be explained with the help of CSCs supported by anti‐apoptotic signaling. CSCs mimic normal adult stem cells by demonstrating unique characteristics of self‐renewal and pluripotency, and the critical role for tumor growth and resistance to anti‐cancer therapy. We found that CD13 was a surface marker for CSCs in human liver cancer cell lines and clinical samples, and that CD13+ CSCs were associated with a hypoxic marker in clinical hepatocellular carcinoma (HCC) sample, suggesting that CD13+ CSCs have the critical role in tumor growth and resistance to anti‐cancer therapy in liver cancers. In this review article, we update recent findings regarding the involvement of CSCs, especially in HCC.
Glucokinase contributes to glucose phosphorylation in d-lactic acid production by Sporolactobacillus inulinus Y2-8
Authors: Zheng Lu , Bai Zhongzhong , Xu Tingting , He Bingfang 
Published: August 2012

Abstract
Sporolactobacillus inulinus, a homofermentative lactic acid bacterium, is a species capable of efficient industrial d-lactic acid production from glucose. Glucose phosphorylation is the key step of glucose metabolism, and fine-tuned expression of which can improve d-lactic acid production. During growth on high-concentration glucose, a fast induction of high glucokinase (GLK) activity was observed, and paralleled the patterns of glucose consumption and d-lactic acid accumulation, while phosphoenolpyruvate phosphotransferase system (PTS) activity was completely repressed. The transmembrane proton gradient of 1.3–1.5 units was expected to generate a large proton motive force to the uptake of glucose. This suggests that the GLK pathway is the major route for glucose utilization, with the uptake of glucose through PTS-independent transport systems and phosphorylation of glucose by GLK in S. inulinus d-lactic acid production. The gene encoding GLK was cloned from S. inulinus and expressed in Escherichia coli. The amino acid sequence revealed significant similarity to GLK sequences from Bacillaceae. The recombinant GLK was purified and shown to be a homodimer with a subunit molecular mass of 34.5 kDa. Strikingly, it demonstrated an unusual broad substrate specificity, catalyzing phosphorylation of 2-deoxyglucose, mannitol, maltose, galactose and glucosamine, in addition to glucose. This report documented the key step concerning glucose phosphorylation of S. inulinus, which will help to understand the regulation of glucose metabolism and d-lactic acid production.
Construction and application of an Escherichia coli bioreporter for aniline and chloroaniline detection
Authors: Vangnai Alisa S , Kataoka Naoya , Soonglerdsongpha Suwat , Kalambaheti Chatvalee , Tajima Takahisa , Kato Junichi 
Published: August 2012

Abstract
Aniline and chlorinated anilines (CAs) are classified as priority pollutants; therefore, an effective method for detection and monitoring is required. In this study, a green-fluorescence protein-based bioreporter for the detection of aniline and CAs was constructed in Escherichia coli DH5α, characterized and tested with soil and wastewater. The sensing capability relied on the regulatory control between a two-component regulatory protein, TodS/TodT, and the PtodX promoter of Pseudomonas putida T-57 (PpT57), since the gene expression of todS, todT, and todC2 are positively induced with 4-chloroaniline. The bioreporter system (DH5α/pPXGFP–pTODST) is markedly unique with the two co-existing plasmids. The inducibility of the fluorescence response was culture-medium- and time-dependent. Cells grown in M9G medium exhibited a low background fluorescence level and were readily induced by 4CA after 3-h exposure, reaching the maximum induction level at 9 h. When tested with benzene, toluene, ethyl-benzene and xylene, aniline and CAs, the response data were best fit by a sigmoidal dose–response relationship, from which the K 1/2 value was determined for the positive effectors. 3CA and 4CA were relatively powerful inducers, while some poly-chlorinated anilines could also induce green fluorescence protein expression. The results indicated a broader recognition range of PpT57’sTodST than previously reported for P. putida. The test results with environmental samples were reliable, indicating the potential application of this bioreporter in the ecotoxicology assessment and bioremediation of areas contaminated with aniline- and/or CAs.
Genetic Analysis of Disheveled 2 and Disheveled 3 in Human Neural Tube Defects
Authors: De Marco Patrizia , Merello Elisa , Consales Alessandro , Piatelli Gianluca , Cama Armando , Kibar Zoha , Capra Valeria 
Published: August 2012

AbstractNeural tube defects are severe malformations affecting 1/1,000 live births. The planar cell polarity pathway controls the neural tube closure and has been implicated in the pathogenesis of neural tube defects both in animal models and human cohorts. In mouse disruption ofDvl2alone (Dvl2−/−) orDvl2andDvl3(Dvl2−/−;Dvl3+/−,Dvl2+/−;Dvl3−/−) results in incomplete neurulation, suggesting a role for Disheveled in neural tube closure. Disheveled is a multifunctional protein that is involved in both the canonical Wnt signaling and the noncanonical planar cell polarity pathway. In this study, we analyzed the role of the human orthologsDVL2andDVL3in a cohort of 473 patients with neural tube defects. Rare variants were genotyped in 639 ethnically matched controls. We identified seven rare missense mutations that were absent in all controls analyzed. Two of these mutations, p.Tyr667Cys and p.Ala53Val, identified inDVL2were predicted to be detrimental in silico. Significantly, a 1-bp insertion (c.1801_1802insG) in exon 15 ofDVL2predicted to lead to the truncation of the protein was identified in a patient with a complex form of caudal agenesis. In summary, we demonstrate a possible role for rare variants inDVL2gene as risk factors for neural tube defects.