bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and tribological properties of NbSe3 nanofibers and NbSe2 microsheets
Authors: Tang Hua , Li Changsheng , Yang Xiaofei , Mo Chaochao , Cao Kesheng , Yan Fengyuan 
Published: March 2011

AbstractNbSe3 nanofibers and NbSe2 sheets were prepared by solid state reaction. The as‐prepared products are characterized by powder X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The results showed that the obtained NbSe3 nanofibers have a diameter in the range of 100–300 nm and length about 10 μm, while the NbSe2 sheets have a hexagon structure. The tribological properties of the as‐prepared NbSex powders as additives in HVI500 base oil were investigated on UMT‐2 multispecimen tribo‐tester. The wear scars were measured by VEECO WYKO NT1100 non‐contact optical profile testing instrument. It is found that the addition of both NbSex nanofibers/sheets improves the tribological properties of base oil. Furthermore, NbSe2 sheets exhibit better friction reduction and wear resistance properties than NbSe3 nanofibers in HVI500 base oil. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Basal cell adenoma: A diagnostic dilemma on fine needle aspiration cytology
Authors: Gupta Nalini , Bal Amanjit , Gupta Ashok Kumar , Rajwanshi Arvind 
Published: March 2011

AbstractBasal cell adenoma (BCA) is a rare neoplasm which is one of the basaloid tumors of salivary gland. Basaloid tumors are the most difficult problem in salivary gland fine needle aspiration cytology (FNAC). There are various benign and malignant tumors such as; cellular pleomorphic adenoma, basal cell adenocarcinoma, adenoid cystic carcinoma, metastatic basal cell carcinoma, metastatic basaloid squamous carcinoma and small cell carcinoma in differential diagnosis. We present a case of BCA, membranous type in a 39‐year‐old female with right submandibular swelling misinterpreted as adenoid cystic carcinoma (ACC) on FNAC. Diagn. Cytopathol. 2011. © 2011 Wiley Periodicals, Inc.
Synthesis, Molecular Structure, and Physical Properties of the Complexes [{PhB(pz)2(CH2SMe)}2M] (M = MnII, FeII; pz = pyrazol‐1‐yl) Containing a Novel [N,N,S]‐Heteroscorpionate Ligand
Authors: Reus Christian , Ruth Kai , Tüllmann Sandor , Bolte Michael , Lerner Hans‐Wolfram , Weber Birgit , Holthausen Max C. , Wagner Matthias 
Published: March 2011

AbstractTwo transition metal complexes [L2M] {M = FeII (2), MnII (3)} of the novel [N,N,S] scorpionate ligand L = [PhB(pz)2(CH2SMe)]– have been synthesized and characterized by X‐ray crystallography, magnetic measurements, cyclic voltammetry, and various spectroscopic techniques. In the solid state, both complexes 2 and 3 possess a distorted octahedral ligand sphere, but adopt different configurations (2: cis; 3: trans). According to X‐ray diffraction data, Mössbauer spectroscopy, and SQUID measurements, compound 2 exists as low‐spin complex in the solid state at temperatures T ≤ 20 °C (μeff ≈ 0.5 μB). Upon heating, the magnetic moment μeff increases continuously to a value of 1.8 μB at 90 °C, which indicates a temperature dependent high‐spin ↔ low‐spin transition above room temp. Solutions of 2 in CDCl3 showed paramagnetic behavior at 25 °C (μeff = 3.1 μB; Evans NMR method). Cyclic voltammetry (CH2Cl2, [Bu4N][PF6]; vs. FcH/FcH+) on 2 reveals a reversible FeII/FeIII redox transition at E1/2 = –0.16 V. Density functional theory (B3LYP‐D/def2‐TZVPP//B3LYP‐D/SVP level) has been used to evaluate relative energies of the cis and trans isomers of 2 in their high‐spin and low‐spin states. Theoretical and experimental investigations have been extended to the related literature‐known homoleptic FeII complexes [{PhB(pz)3}2Fe], [{PhB(pz)(CH2SMe)2}2Fe], and [{PhB(CH2SMe)3}2Fe]. The following order of ligand‐field strengths has been established: [PhB(CH2SMe)3]– < [PhB(pz)(CH2SMe)2]– < [PhB(pz)2(CH2SMe)]– < [PhB(pz)3]–. The only significant deviation from this systematic behavior became evident for the unexpectedly low solution magnetic moment of [{PhB(CH2SMe)3}2Fe], which finds no parallel in the solid state. Computed spin‐state splittings for the entire series of complexes, however, confirm the trend in solution magnetic moments and we relate the disaccording experimental observations to the presence of a second stereoisomer in crystals of [{PhB(CH2SMe)3}2Fe] which increases the paramagnetism of solid‐state samples of this complex.
Selective Chemical Oxidation of Risperidone: A Straightforward and Cost‐Effective Synthesis of Paliperidone
Authors: Riva Renata , Banfi Luca , Castaldi Graziano , Ghislieri Diego , Malpezzi Luciana , Musumeci Francesca , Tufaro Roberto , Rasparini Marcello 
Published: March 2011

AbstractA very short and cost‐effective synthesis of the commercial drug paliperidone has been achieved starting from its parent compound risperidone, through a thoroughly optimized oxidation with air under basic conditions.
Copper‐Catalyzed Direct Synthesis of 3‐Arylindoles
Authors: Murru Siva , Gallo August A. , Srivastava Radhey S. 
Published: March 2011

AbstractA direct method for the preparation of various 3‐arylindoles from their corresponding nitrosoarenes has been developed. Various substituted nitrosoarenes and alkynes were employed to obtain substituted indoles by using a CuII–Cu0 catalytic system. This is a two‐step method that involves annulation of the nitrosoarene and alkyne followed by deoxygenation to give 3‐arylindoles.
High yield and cost‐effective production of poly(γ‐glutamic acid) with Bacillus subtilis
Authors: Huang Jin , Du Yinming , Xu Guohua , Zhang Huili , Zhu Fan , Huang Lei , Xu Zhinan 
Published: March 2011

AbstractPoly(γ‐glutamic acid) (γ‐PGA) is a promising biopolymer with many potential industrial and pharmaceutical applications. To reduce the production costs, the effects of yeast extract and L‐glutamate in the substrate for γ‐PGA production were investigated systematically at shake flask scale. The results showed that lower concentrations of yeast extract (40 g/L) and L‐glutamate (30 g/L) were beneficial for the cost‐effective production of γ‐PGA in the formulated medium. By maintaining the glucose concentration in the range of 3–10 g/L via a fed‐batch strategy in a 10‐L fermentor, the production of γ‐PGA was greatly improved with the highest γ‐PGA concentration of 101.1 g/L, a productivity of 2.19 g/L·h and a yield of 0.57 g/g total substrate, which is about 1.4‐ to 3.2‐fold higher than those in the batch fermentation. Finally, this high‐density fermentation process was successfully scaled up in a 100‐L fermentor. The present work provides a powerful approach to produce this biopolymer as a bulk chemical in large scale.
The human carcinogen aristolochic acid i is activated to form DNA adducts by human NAD(P)H:quinone oxidoreductase without the contribution of acetyltransferases or sulfotransferases
Authors: Stiborová Marie , Mareîs Jaroslav , Frei Eva , Arlt Volker M. , Martínek Václav , Schmeiser Heinz H. 
Published: March 2011

AbstractIngestion of aristolochic acid (AA) is associated with development of urothelial tumors linked with AA nephropathy and is implicated in the development of Balkan endemic nephropathy‐associated urothelial tumors. We investigated the efficiency of human NAD(P)H:quinone oxidoreductase (NQO1) to activate aristolochic acid I (AAI) and used in silico docking, using soft–soft (flexible) docking procedure, to study the interactions of AAI with the active site of human NQO1. AAI binds to the active site of NQO1 indicating that the binding orientation allows for direct hydride transfer (i.e., two electron reductions) to the nitro group of AAI. NQO1 activated AAI, generating DNA adduct patterns reproducing those found in urothelial tissues from humans exposed to AA. Because reduced aromatic nitro‐compounds are often further activated by sulfotransferases (SULTs) or N,O‐acetlytransferases (NATs), their roles in AAI activation were investigated. Our results indicate that phase II reactions do not play a major role in AAI bioactivation; neither native enzymes present in human hepatic or renal cytosols nor human SULT1A1, ‐1A2, ‐1A3, ‐1E, or ‐2A nor NAT1 or NAT2 further enhanced DNA adduct formation by AAI. Instead under the in vitro conditions used, DNA adducts arise by enzymatic reduction of AAI through the formation of a cyclic hydroxamic acid (N‐hydroxyaristolactam I) favored by the carboxy group in peri position to the nitro group without additional conjugation. These results emphasize the major importance of NQO1 in the metabolic activation of AAI and provide the first evidence that initial nitroreduction is the rate limiting step in AAI activation. Environ. Mol. Mutagen., 2011. © 2011 Wiley‐Liss, Inc.
Role of DNA polymerase beta in the genotoxicity of arsenic
Authors: Lai Yanhao , Zhao Wei , Chen Chen , Wu Mei , Zhang Zunzhen 
Published: March 2011

AbstractArsenic, an important hazard in the environment, is associated with human cancer and other degenerative diseases. However, the mechanisms underlying arsenic hazardous effects remain unclear. It has been reported arsenic exposure can result in increased cellular reactive oxygen species and oxidative DNA damage. This suggests DNA base excision repair (BER), the major pathway for repairing oxidative DNA damage, may be involved in combating arsenic hazardous effects. As a critical repair enzyme in BER, DNA polymerase beta (Pol β) might play an essential role in reducing arsenic toxicity. To test this hypothesis, we evaluated arsenic‐induced cytotoxic and genotoxic effects under Pol β deficiency. Our results demonstrated that the viability of Pol β‐deficient mouse embryonic fibroblasts was much lower than that of Pol β wild‐type cells after treatment with arsenite (As3+). An increased level of DNA damage and significantly delayed arsenite‐induced DNA damage repair in Pol β‐deficient cells indicated reduced repair of DNA lesions under Pol β deficiency. This was consistent with the increase in the frequency of micronuclei (MN), an indicator of chromosomal breakage, which was also observed in Pol β‐deficient cells treated with arsenite. In contrast, cells harboring overexpressed Pol β resulted in a lower level of DNA damage and MN than Pol β wild‐type cells, indicating overexpression of the enzyme can combat arsenic‐induced genotoxic effects. In conclusion, our results indicate an important role for Pol β in repairing arsenite‐induced DNA damage and maintaining chromosomal integrity and further suggest deficiency of BER may be involved in arsenic genotoxicity and carcinogenicity. Environ. Mol. Mutagen., 2011. © 2011 Wiley‐Liss, Inc.
Comparison of mercury concentrations in landlocked, resident, and sea-run fish (Salvelinus spp.) from Nunavut, Canada
Authors: Swanson Heidi , Gantner Nikolaus , Kidd Karen A , Muir D.C.G , Reist James D 
Published: March 2011

Abstract
Mercury concentrations ([Hg]) in Arctic food fish often exceed guidelines for human subsistence consumption. Previous research on two food fish species, Arctic char (Salvelinus alpinus) and lake trout (Salvelinus namaycush), indicates that anadromous fish have lower [Hg] than nonanadromous fish, but there have been no intraregional comparisons. Also, no comparisons of [Hg] among anadromous (sea-run), resident (marine access but do not migrate), and landlocked (no marine access) life history types of Arctic char and lake trout have been published. Using intraregional data from 10 lakes in the West Kitikmeot area of Nunavut, Canada, we found that [Hg] varied significantly among species and life history types. Differences among species–life history types were best explained by age-at-size and C:N ratios (indicator of lipid); [Hg] was significantly and negatively related to both. At a standardized fork length of 500 mm, lake trout had significantly higher [Hg] (mean 0.17 µg/g wet wt) than Arctic char (0.09 µg/g). Anadromous and resident Arctic char had significantly lower [Hg] (each 0.04 µg/g) than landlocked Arctic char (0.19 µg/g). Anadromous lake trout had significantly lower [Hg] (0.12 µg/g) than resident lake trout (0.18 µg/g), but no significant difference in [Hg] was seen between landlocked lake trout (0.21 µg/g) and other life history types. Our results are relevant to human health assessments and consumption guidance and will inform models of Hg accumulation in Arctic fish. Environ. Toxicol. Chem. 2011; 30:1459–1467. © 2011 SETAC
TCP flow aware adaptive path switching in diffserv enabled MPLS networks
Authors: Alparslan Onur , Akar Nail , Karasan Ezhan 
Published: March 2011

AbstractWe propose an adaptive flow‐level multi‐path routing‐based traffic engineering solution for an IP backbone network carrying TCP/IP traffic. Incoming TCP flows are switched between two explicitly routed paths, namely the primary and secondary paths (PP and SP), for resilience and potential goodput improvement at the TCP layer. In the proposed architecture, PPs receive a preferential treatment over SPs using differentiated services mechanisms. The reason for this choice is not for service differentiation but for coping with the detrimental knock‐on effect stemming from the use of longer SP that is well known for conventional network load balancing algorithms. Moreover, both paths are congestion‐controlled using Explicit Congestion Notification marking at the core and Additive Increase Multiplicative Decrease rate adjustment at the ingress nodes. The delay difference between PP and SP is estimated using two per‐egress rate‐controlling buffers maintained at the ingress nodes for each path, and this delay difference is used to determine the path over which a new TCP flow will be routed. We perform extensive simulations using ns‐2 in order to demonstrate the viability of the proposed distributed adaptive multi‐path routing method in terms of per‐flow TCP goodput. The proposed solution consistently outperforms the single‐path routing policy and provides substantial per‐flow goodput gains under poor PP conditions. Moreover, highest goodput improvements under the proposed scheme are achieved by flows that receive the lowest goodputs with single‐path routing, while the performance of the flows with high goodputs with single‐path routing does not deteriorate with the proposed path switching technique. Copyright © 2011 John Wiley & Sons, Ltd.
Stabilized finite element method based on local preconditioning for unsteady compressible flows in deformable domains with emphasis on the low Mach number limit application
Authors: López Ezequiel J. , Nigro Norberto M. , Sarraf Sofía S. , Damián Santiago Márquez 
Published: March 2011

SUMMARYFlows with low Mach numbers represent a limit situation in the solution of compressible flows. The preconditioning of flow equations is one of the classical approaches proposed to capture the solution in the low Mach number limit. In this method, the time derivatives are premultiplied by a suitable preconditioning matrix in order to achieve a well‐conditioned system by means of the scaling of the system eigenvalues. Hence, the modified equations have only steady‐state solutions in common with the original system. For the application of these methods to unsteady problems, the dual time‐stepping technique has emerged, where the physical time derivative terms are treated as source and/or reactive terms. The use of a preconditioning matrix defined to compute steady‐state solutions may not be a good choice for unsteady problems, as showed by Vigneronit et al. (European Conference on Computational Fluid Dynamics, 2006). However, such matrices can be adapted to perform the computation of transient flows by means of the appropriate redefinition of some coefficients. The application of a ‘steady‐state’ preconditioning matrix to unsteady problems with an ALE (Arbitrary Lagrangian Eulerian) approach is presented. The equations are discretized in space using a stabilized Finite Element method and in time using finite differences. The preconditioning of the governing equations is not applied in the numerical scheme but is used, through the eigenvalues of the preconditioned system, to design appropriately the stabilization term. Several test cases are solved, including incompressible flows and the in‐cylinder flow in a motored opposed‐piston engine. Copyright © 2011 John Wiley & Sons, Ltd.
Highly Sulphonated Multiblock‐co‐polymers for Direct Methanol Fuel Cells
Authors: Krajinovic K. , Kaz T. , Haering T. , Gogel V. , Kerres J. 
Published: March 2011

AbstractMultiblock‐co‐polymers with different ion exchange capacities were synthesised by nucleophilic aromatic step‐growth polycondensation of hydrophilic and hydrophobic oligomers. The main focus of this work was to investigate the dependence of oligomer reactivity on molecular weight and how the reaction conditions need to be changed to obtain high‐molecular multiblock‐co‐polymers, consisting of long block segments. Multiblock‐co‐polymers composed of short oligomers could be synthesised under mild reaction conditions. The coupling of longer oligomers required more basic reaction conditions, because the reactive functional end‐groups were shielded by the long oligomeric main chain. The membranes were investigated further in terms of their properties relevant for use as polymer electrolyte membrane in direct methanol fuel cells (DMFCs). The mechanical stability of the acidic polymers was improved through ionical crosslinking with basic polybenzimidazole. A series of membranes was tested in a self‐ and in an air‐breathing DMFC.
Change in stress and social support as predictors of cognitive decline in older adults with and without depression
Authors: Dickinson Whitney J. , Potter Guy G. , Hybels Celia F. , McQuoid Douglas R. , Steffens David C. 
Published: March 2011

AbstractObjectiveThe relationship between stress, social support, and cognition in geriatric depression is complex. In this study, we sought to examine whether an increase in stressful life events or a decrease in social support would lead to subsequent cognitive decline among older adults with and without depression.MethodsThe sample consisted of 112 depressed and 101 non‐depressed older adults who enrolled in the Neurocognitive Outcomes of Depression in the Elderly (NCODE) study. Participants were assessed clinically, agreed to interviews focusing on stressful life events and social support, and underwent a battery of neuropsychological tests annually. Our global measure of cognition was the Consortium to Establish a Registry in Alzheimer's disease Total Score (CERAD TS).ResultsWe found that a decline in the total number of stressors was associated with a subsequent improvement on CERAD TS. In terms of social support, decreased social interaction, and instrumental social support predicted decline in cognitive performance. These relationships were significant even after controlling for depression status, age, education, and sex.ConclusionsThese findings extend prior research on the importance of social factors in aging and depression which have largely focused on mood‐related outcomes. Future confirmatory studies are needed. In addition, biological and other studies should be conducted to further our understanding of the relationship between stress, social support and cognition in older adults with and without depression. Copyright © 2011 John Wiley & Sons, Ltd.
Biomechanical and histologic evaluation of tissue engineered ligaments using chitosan and hyaluronan hybrid polymer fibers: A rabbit medial collateral ligament reconstruction model
Authors: Irie Toru , Majima Tokifumi , Sawaguchi Naohiro , Funakoshi Tadanao , Nishimura Shin‐ichiro , Minami Akio 
Published: March 2011

AbstractIn this study, we used a rabbit medial collateral ligament reconstruction model to evaluate a novel chitosan‐based hyaluronan hybrid polymer fiber scaffold for ligament tissue engineering and to examine whether mechanical forces exerted in an in vivo model increased extracellular matrix production by seeded fibroblasts. Scaffolds were used 2 weeks after incubation with fibroblasts obtained from the same rabbit in a cell‐seeded scaffold (CSS) group and without cells in a noncell‐seeded scaffold (NCSS) group. At 3, 6, and 12 weeks after surgery, the failure loads of the engineered ligaments in the CSS groups were significantly greater than those in the NCSS groups. At 6 weeks after surgery, the reconstructed tissue of the CSS group was positive for type I collagen, whereas that in the NCSS group was negative for type I collagen. At 12 weeks after surgery, the reconstructed tissue stained positive for type I collagen in the CSS group, but negative in the NCSS group. Our results indicate that the scaffold material enhanced the production of type I collagen and led to improved mechanical strength in the engineered ligament in vivo. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Controlling cell growth on titanium by surface functionalization of heptylamine using a novel combined plasma polymerization mode
Authors: Zhao Jing H. , Michalski Wojtek P. , Williams Catherine , Li Li , Xu Hong‐Sheng , Lamb Peter R. , Jones Scott , Zhou Yan M. , Dai Xiujuan J. 
Published: March 2011

AbstractA novel bio‐interface, produced by a combined plasma polymerization mode on a titanium (Ti) surface, was shown to enhance osteoblast growth and reduce fibroblast cell growth. This new method can securely attach a tailored interface to difficult materials such as Ti or ceramics. Here a more stable and higher density of NH2 functional groups is able to withstand sterilization in ethanol. The biocompatibility, in terms of cell attachment and actin cytoskeleton development, was markedly improved in vitro, compared with untreated Ti surfaces and samples treated by other plasma modes. It gave a boosted (approximately six times higher) cellular response of osteoblasts in their initial adhesion stage. These factors should increase the formation of new bone around implants (reducing healing time), promoting osseointegration and thereby increasing implantation success rates. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.
Development of chitosan–vancomycin antimicrobial coatings on titanium implants
Authors: Swanson T. E. , Cheng X. , Friedrich C. 
Published: March 2011

AbstractTechniques for titanium surface modification have been studied for applications in orthopedic implants specifically for local drug delivery. The extensive research in surface modification is driving the development of devices that integrate infection prevention, osseointegration, and functionality in a structural role. In this study, vancomycin was applied to modified titanium surfaces to determine the effect of surface morphology on drug loading and release profiles. The antimicrobial effectiveness of the released vancomycin was evaluated and found to have a similar effect as the standard vancomycin. The engineered surfaces included sandblasted, sandblasted acid etched, electrochemically etched, and sandblasted electrochemically etched. The antibiotic release was observed to be independent of the measured surface parameters of the engineered surfaces. The development of an implantable device in which the surface morphology can be tailored for an application with no effect on the total drug released would be beneficial to more precisely control the biological response while maintaining local drug delivery for infection prevention. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2011.