bluuebunny/crossref_metadata_2025_split huggingface dataset:
Low clonogenic potential of circulating angiogenic cells is associated with lower density of capillaries in skeletal muscle in patients with impaired glucose tolerance
Authors: Prior Steven J. , Ryan Alice S. 
Published: February 2013

AbstractBackgroundReduced density of capillaries in skeletal muscle can limit insulin, glucose, and oxygen supply to the muscle, thereby contributing to worsening metabolism in older adults. The lower skeletal muscle capillarization in impaired glucose tolerance (IGT) may partially be due to circulating angiogenic cell dysfunction. Circulating angiogenic cells maintain the vasculature and promote angiogenesis, but circulating angiogenic cell number and function may be reduced in IGT. The goal of this study was to determine whether the clonogenic potential of circulating angiogenic cells is lower in IGT compared with normal‐glucose‐tolerant (NGT) controls and is associated with skeletal muscle capillarization.MethodsGlucose tolerance, endothelial cell colony‐forming unit (CFU‐EC) number, and vastus lateralis capillary density were measured in sedentary, older (62 ± 1 years, mean ± SEM) men and women with NGT (n = 16) and IGT (n = 12).ResultsAdults with IGT had 43% lower CFU‐EC number (11.4 ± 2.3 versus 20.1 ± 2.0 colonies, p < 0.01) and 12% lower capillary density (291 ± 11 versus 330 ± 9 capillaries/mm2, p < 0.01) compared with those with NGT. In regression analyses, CFU‐EC number inversely correlated with 120‐min postprandial glucose in all subjects (r = −0.47, p < 0.05), and capillary density was directly associated with CFU‐EC number (r = 0.53, p < 0.05).ConclusionsWe conclude that the clonogenic potential of circulating angiogenic cells is lower in sedentary older adults with IGT and is associated with lower skeletal muscle capillarization. Low circulating angiogenic cell clonogenic potential in IGT suggests a state of impaired angiogenesis occurring prior to overt type 2 diabetes that may mediate early microvascular changes in the development and progression of IGT to type 2 diabetes. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Tris(organotin)tungstogermanate, a Sandwich Organometallic Derivative of a Keggin‐Type Polyoxometalate: Synthesis and DFT Study
Authors: Liu Huizhang , Bandeira Nuno A. G. , Félix Vitor , Calhorda Maria José 
Published: February 2013

AbstractA phenyltin‐containing Keggin‐based polyoxometalate has been synthesised and characterised by elemental analysis, infrared and electronic spectroscopy, and multinuclear NMR spectroscopy. Structural data, complemented by DFT calculations, suggests that three phenyltin groups connect two [α‐GeW9O34]10– moieties to form the [(C6H5SnOH)3(α‐GeW9O34)2]14– anion. Each tin atom displays a distorted‐octahedral environment, composed of two sets of equatorial oxygen atoms from two edge‐sharing WO6 octahedra of each [α‐GeW9O34]10– group, and one phenyl and one OH group in the axial positions. The DFT studies lend support to the experimental proposal of the molecular structure of this polyoxometalate. The similar energy of the limiting arrangements of phenyl groups demonstrates how their fluxionality occurs as a dynamical process in solution and explains the disorder in the solid.
Synthesis of Gemini Surfactants and Evaluation of Their Interfacial and Cytotoxic Properties: Exploring the Multifunctionality of Serine as Headgroup
Authors: Silva Sandra G. , Alves Cláudia , Cardoso Ana M. S. , Jurado Amália S. , Pedroso de Lima Maria C. , Vale M. Luísa C. , Marques Eduardo F. 
Published: February 2013

AbstractTwo series of novel cationic gemini surfactants based on the amino acid serine have been synthesized. These compounds contain long alkyl chains linked to the nitrogen atoms of the amino acid residues, as well as spacers interconnecting two carboxylic acid groups, through amide or ester bonds. The most efficient synthetic pathway was established; it involves the introduction of the spacers into the N,N‐dialkylated monomeric precursors by peptide condensation methods with diamines or diols, with subsequent methylation and deprotection to yield the final target surfactants. The effects of molecular structure, type of spacer linkage, and spacer length on the interfacial and cytotoxic properties of these gemini surfactants are reported and discussed; studies on gemini surfactants with amine linkages and other relevant homologous compounds (conventional bis‐quat gemini and monomeric surfactants) are also included. Overall, it is shown that cationic serine‐based gemini surfactants have enhanced interfacial properties and low cytotoxicities, offering potential use in technical and biological applications.
5,6‐Bis(octyloxy)benzo[c][1,2,5]thiadiazole‐Bridged Dyes for Dye‐Sensitized Solar Cells with High Open‐Circuit Voltage Performance
Authors: Chen Long , Li Xin , Ying Weijiang , Zhang Xiaoyu , Guo Fuling , Li Jing , Hua Jianli 
Published: February 2013

AbstractThree new metal‐free dyes with a 5,6‐bis(octyloxy)benzo[c][1,2,5]thiadiazole core (DOBT‐I–III) have been designed and synthesized for use as DSSCs. Their absorption properties and electrochemical and photovoltaic performances have been investigated systematically. The DSSCs based on DOBT‐I–III show high open‐circuit voltages (Voc) of 829, 818, and 784 mV, respectively. Of the three dyes, DOBT‐III, which contains a thiophene‐bridging linker, exhibits the best photovoltaic performance: a short‐circuit photocurrent density (Jsc) of 12.74 mA cm–2 and a fill factor (FF) of 0.73, which corresponds to an overall conversion efficiency of 7.29 % under standard global AM 1.5 solar conditions.
The Sulfinyl Group as a Remote Chiral Auxiliary in Stereoselective Conjugate Additions of Alkyl Groups to α‐Methylidene Carbonyl Compounds Initiated by Et3B/O2
Authors: Fernández‐Salas José Antonio , Maestro M. Carmen , Rodríguez‐Fernández M. Mercedes , García Ruano José L. 
Published: February 2013

AbstractReactions of α‐[2‐(p‐tolylsulfinyl)phenyl] α‐methylidene carbonyl compounds 1 and 2 with alkyl radicals generated from Et3B/O2 and RI give, after protonation, β‐alkyl derivatives with a high degree of control of the configuration at the α carbon. In the case of aldehyde 2, when further combined with allylation of the carbonyl group, a one‐pot radical‐addition/protonation/allylation sequence provides a highly stereoselective synthesis of compounds bearing two adjacent chiral centres. The stereochemical course of the reaction is controlled by the sulfinyl group acting as a remote chiral auxiliary, and this group can be easily removed with tBuLi.
Sediment routing hypothesis for pool‐riffle maintenance
Authors: Milan David J. 
Published: February 2013

ABSTRACTThis paper provides comprehensive evidence that sediment routing around pools is a key mechanism for pool‐riffle maintenance in sinuous upland gravel‐bed streams. The findings suggest that pools do not require a reversal in energy for them to scour out any accumulated sediments, if little or no sediments are fed into them. A combination of clast tracing using passive integrated transponder (PIT) tagging and bedload traps (positioned along the thalweg on the upstream riffle, pool entrance, pool exit and downstream riffle) are used to provide information on clast pathways and sediment sorting through a single pool‐riffle unit. Computational fluid dynamics (CFD) is also used to explore hydraulic variability and flow pathways. Clast tracing results provide a strong indication that clasts are not fed through pools, rather they are transported across point bar surfaces, or around bar edges (depending upon previous clast position, clast size, and event magnitude). Spatial variations in bedload transport were found throughout the pool‐riffle unit. The pool entrance bedload trap was often found to be empty, when the others had filled, further supporting the notion that little or no sediment was fed into the pool. The pool exit slope trap would occasionally fill with sediment, thought to be sourced from the eroding outer bank. CFD results demonstrate higher pool shear stresses (τ ≈ 140 N m–2) in a localized zone adjacent to an eroding outer bank, compared to the upstream and downstream riffles (τ ≈ 60 N m–2) at flows of 6 · 2 m3 s–1 (≈ 60% of the bankfull discharge) and above. There was marginal evidence for near‐bed velocity reversal. Near‐bed streamlines, produced from velocity vectors indicate that flow paths are diverted over the bar top rather than being fed through the thalweg. Some streamlines appear to brush the outer edge of the pool for the 4 · 9 m3 s–1 to 7 · 8 m3 s–1 (between 50 and 80% of the bankfull discharge) simulations, however complete avoidance was found for discharges greater than this. Copyright © 2013 John Wiley & Sons, Ltd.
MicroRNA-26a suppresses tumor growth and metastasis of human hepatocellular carcinoma by targeting interleukin-6-Stat3 pathway
Authors: Yang Xin , Liang Lei , Zhang Xiao-Fei , Jia Hu-Liang , Qin Yi , Zhu Xu-Chao , Gao Xiao-Mei , Qiao Peng , Zheng Yan , Sheng Yuan-Yuan , Wei Jin-Wang , Zhou Hai-Jun , Ren Ning , Ye Qing-Hai , Dong Qiong-Zhu , Qin Lun-Xiu 
Published: February 2013

Abstract

Down-regulation of microRNA-26a (miR-26a) is associated with poor prognosis of hepatocellular carcinoma (HCC), but its functional mechanism in HCC remains unclear. In this study, we investigated the roles of miR-26a in tumor growth and metastasis of HCC and found that miR-26a was frequently down-regulated in HCC tissues. Down-regulation of miR-26a correlated with HCC recurrence and metastasis. Through gain- and loss-of-function studies, miR-26a was demonstrated to significantly inhibit in vitro cell proliferation, migration, and invasion. In addition, miR-26a induced G1 arrest and promoted apoptosis of HCC cells. Importantly, miR-26a suppressed in vivo tumor growth and metastasis in nude mice models bearing human HCC. Interleukin-6 (IL-6) was identified as a target of miR-26a. Knockdown of IL-6 induced effects on HCC cells similar to those induced by miR-26a. In contrast, IL-6 treatment abrogated the effects induced by miR-26a up-regulation. Moreover, miR-26a dramatically suppressed expression of signal transducer and activator of transcription 3 (Stat3) target genes, including Bcl-2, Mcl-1, cyclin D1, and MMP2. IL-6 treatment antagonized this effect, while knockdown of IL-6 by IL-6 short hairpin RNA (shIL-6) induced inhibitory effects on the expression of p-Stat3 and its main target genes, similar to miR-26a. The messenger RNA and protein levels of IL-6 inversely correlated with miR-26a in HCCs. Patients with high miR-26a or low IL-6 in HCC tissues had a better prognosis with longer overall survival (OS) and time to recurrence (TTR). In multivariate analysis, miR-26a, IL-6, and their combination were demonstrated to be independent prognostic indicators for OS and TTR of HCC patients. Conclusion: miR-26a could suppress tumor growth and metastasis of HCC through IL-6-Stat3 signaling and is a novel prognostic marker and therapeutic target for HCC. (HEPATOLOGY 2013)
Embolization of large spontaneous portosystemic shunts for refractory hepatic encephalopathy: A multicenter survey on safety and efficacy
Authors: Laleman Wim , Simon-Talero Macarena , Maleux Geert , Perez Mercedes , Ameloot Koen , Soriano German , Villalba Jordi , Garcia-Pagan Juan-Carlos , Barrufet Marta , Jalan Rajiv , Brookes Jocelyn , Thalassinos Evangelos , Burroughs Andrew K. , Cordoba Juan , Nevens Frederik 
Published: February 2013

Abstract

Refractory hepatic encephalopathy (HE) remains a major cause of morbidity in cirrhosis patients. Large spontaneous portosystemic shunts (SPSSs) have been previously suggested to sustain HE in these patients. We aimed to retrospectively assess the efficacy and safety of patients treated with embolization of large SPSSs for the treatment of chronic therapy-refractory HE in a European multicentric working group and to identify patients who may benefit from this procedure. Between July 1998 and January 2012, 37 patients (Child A6-C13, MELD [Model of Endstage Liver Disease] 5-28) with refractory HE were diagnosed with single large SPSSs that were considered eligible for embolization. On a short-term basis (i.e., within 100 days after embolization), 22 out of 37 patients (59.4%) were free of HE (

P

< 0.001 versus before embolization) of which 18 (48.6% of patients overall) remained HE-free over a mean follow-up period of 697 ± 157 days (

P

< 0.001 versus before embolization). Overall, we noted improved autonomy, decreased number of hospitalizations, and severity of the worst HE episode after embolization in three-quarters of the patients. Logistic regression identified the MELD score as strongest positive predictive factor of HE recurrence with a cutoff of 11 for patient selection. As to safety, we noted one major nonlethal procedure-related complication. There was no significant increase in

de novo

development or aggravation of preexisting varices, portal hypertensive gastropathy, or ascites.

Conclusion

: This multicenter European cohort study demonstrated a role for large SPSSs in chronic protracted or recurrent HE and substantiated the effectiveness and safety of embolization of these shunts, provided there is sufficient functional liver reserve.
Osseointegration of hydroxyapatite and remodeling‐resorption of tricalciumphosphate ceramics
Authors: Draenert Miriam , Draenert Alice , Draenert Klaus 
Published: February 2013

ABSTRACTBackground: Cancellous bone defects surrounded by still intact bone structures never heal. Ceramics offer a solution providing osteoconductive scaffolds. Purpose: The purpose of the study is to evaluate whether structured β‐TCP and HA implants can reconstruct cancellous bone defects, which role micro‐ and macro‐porosity, stiffness and surface area play; finally the indication for both materials based on its resorbability. Material & Methods: 10 German Shepard dogs were operated on both tibial heads implanting shell‐like fully interconnected ceramic cylinders, using a wet grinding hollow drill coated with diamonds. β‐TCP was compared with HA. A polychromatic sequential labelling with 4 different fluorochromes controlled bone formation dynamics. Non‐decalcifying histology after perfusion fixation and vessel casting was performed. μ‐CT was combined with high resolution microradiography and histology on thin ground crossections. The stages after 6 weeks, 2, 3, 4 months and 15 months were evaluated. Results: In spite of osseointegration of HA and β‐TCP, the osseointegration of both materials was completely different. Both shell‐like bone void fillers were osseointegrated in a sandwich‐like manner. HA yielded primarily a reinforcement of the recipient's cancellous‐bone bed and full osseointegration after 4 months, whereas β‐TCP‐implants were fully osseointegrated after 6 weeks. HA did not show signs of resorption. The resorption of the β‐TCP resulted during remodelling. The final stage showed restitution “ad integrum” of the β‐TCP defects with a physiological architecture, whereas HA was integrated in the cancellous bone construction providing 600 μm measuring macropores showing osteoinductive properties. Microsc. Res. Tech. 76:370–380, 2013. © 2013 Wiley Periodicals, Inc.
Performance comparison of three types of GPU‐accelerated indirect boundary element method for voxel model analysis
Authors: Hamada Shoji 
Published: February 2013

SUMMARYAn indirect boundary element method that is geared to electrostatic field analysis in voxel models is accelerated by graphics processing units (GPUs). The method considers square walls on cubic voxels as boundary surface elements and uses the fast multipole method (FMM) to analyze large‐scale models. On the basis of two conventional CPU codes, three GPU codes are programmed in search of higher computing performance. These GPU codes are designed as follows: In GPU code 1, direct and far fields in the FMM are simultaneously calculated on the GPU and the CPU, respectively; in GPU code 2, both fields are calculated on the GPU with a rotation‐coaxial translation–rotation decomposition algorithm; and in GPU code 3, both fields are calculated on the GPU with a diagonal translation scheme. The electric fields in human models are generated by applying a 50‐Hz magnetic field or by injecting direct‐current (DC) current through two electrodes and they were calculated successfully using a personal computer with three GPUs and six CPU cores. An analysis with 3.9 million surface elements took 89.4 s to solve its governing linear system with double‐precision floating‐point arithmetic. GPU codes 1, 2, and 3 demonstrated the least memory usage, the greatest speed‐up ratio, and the fastest calculation time, respectively. These results show an example of the trade‐off relationships of computation performances on a heterogeneous CPU–GPU system. Copyright © 2013 John Wiley & Sons, Ltd.
Patterns of prophylactic gastrostomy tube placement in head and neck cancer patients: A consideration of the significance of social support and practice variation
Authors: Locher Julie L. , Bonner James A. , Carroll William R. , Caudell Jimmy J. , Allison Jeroan J. , Kilgore Meredith L. , Ritchie Christine S. , Tajeu Gabriel S. , Yuan Ya , Roth David L. 
Published: February 2013

Objectives/HypothesisThe purpose of this study was to examine factors associated with prophylactic placement of feeding tubes in head and neck cancer patients receiving radiation therapy as a part of treatment using multilevel models that account for patient‐, physician‐, and institution‐level sources of variation.Study DesignA retrospective analysis using binary logistic regression and hierarchical linear models was run to evaluate independent predictors of prophylactic feeding tube placement.MethodsSurveillance, Epidemiology, and End Results–Medicare data were used. Head and neck cancer patients diagnosed with locoregionally advanced stage disease from 2000 to 2005 were included in this study (N = 8,306).ResultsAcross all models, prophylactic gastrostomy tube placement was found to be more likely in patients who had cancer of the larynx or oropharynx compared with those with cancer of the nasopharynx or oral cavity; who had regional instead of local cancer; who did not receive surgery as a part of treatment, but did receive chemotherapy; and who were divorced, separated, or widowed. Additionally, although practice variation was observed to occur, its overall contribution in predicting prophylactic gastrostomy tube placement was minimal.ConclusionsAs health care enters an era of patient‐centered care, further investigation of the potential role of social support (or lack of social support) in influencing treatment decisions of head and neck cancer patients and providers is warranted.Level of Evidence2b Laryngoscope, 123:1918–1925, 2013
Facile One‐Pot Synthesis of a Polyvinylpyrrolidone‐Based Self‐Crosslinked Fluorescent Film
Authors: Yin Meizhen , Ye Yong , Sun Mengmeng , Kang Naiwen , Yang Wantai 
Published: February 2013

AbstractA polyvinylpyrrolidone (PVP)‐based fluorescent film with stable optical properties is successfully prepared in one pot without any additive. The reaction mechanism of ring‐opening and self‐crosslinking of linear PVP is proposed and demonstrated. The morphologies and the nanostructures of the fluorescent film as well as the unmodified film are investigated. The dye is incorporated into the film networks via covalent linkages, thus leading to the highly stable optical properties. The facile and effective synthesis approach opens a new way for the design of other multi‐functional composite materials based on linear PVP.magnified image
Formation of Integral Asymmetric Membranes of AB Diblock and ABC Triblock Copolymers by Phase Inversion
Authors: Jung Adina , Filiz Volkan , Rangou Sofia , Buhr Kristian , Merten Petra , Hahn Janina , Clodt Juliana , Abetz Clarissa , Abetz Volker 
Published: February 2013

AbstractThe formation of integral asymmetric membranes from ABC triblock terpolymers by non‐solvent‐induced phase separation is shown. They are compared with the AB diblock copolymer precursors. Triblock terpolymers of polystyrene‐block‐poly(2‐vinylpyridine)‐block‐poly(ethylene oxide) (PS‐b‐P2VP‐b‐PEO) with two compositions are investigated. The third block supports the formation of a membrane in a case, where the corresponding diblock copolymer does not form a good membrane. In addition, the hydrophilicity is increased by the third block and due to the hydroxyl group the possibility of post‐functionalization is given. The morphologies are imaged by scanning electron microscopy. The influence of the PEO on the membrane properties is analyzed by water flux, retention, and dynamic contact angle measurements.magnified image
Obstacles to the Development of a Neuroprotective Therapy for Parkinson's Disease
Authors: Stocchi Fabrizio , Olanow C. Warren 
Published: February 2013

ABSTRACTA neuroprotective or disease‐modifying therapy that can slow or stop disease progression and prevent the development of intolerable disability is the major unmet medical need in the treatment of Parkinson's disease (PD). Many putative neuroprotective agents have been identified in the laboratory, but none has been unequivocally demonstrated to provide disease‐modifying effects in PD patients, even when clinical trials are positive. Obstacles to defining a neuroprotective therapy in PD include: (1) uncertainty about the cause of PD and precisely what to target, (2) a reliable animal model in which to test putative neuroprotective agents that accurately predicts results in PD patients, (3) insight about which dose to employ in clinical trials and which patient group to study, (4) a clinical trial design that reliably differentiates disease‐modifying and symptomatic effects and that is acceptable to regulatory authorities, and (5) the cost and time of the development program. Advances have been made in each of these areas, thereby increasing the prospects of developing a neuroprotective or disease‐modifying therapy in the not‐too‐distant future. These issues are reviewed in the present article. © 2013 Movement Disorder Society
Trophic Factor Gene Therapy for Parkinson's Disease
Authors: Kordower Jeffrey H. , Bjorklund Anders 
Published: February 2013

ABSTRACTParkinson's disease (PD) is a chronic and progressive neurodegenerative movement disorder for which there is presently no cure. Pharmacological remedies targeting the dopaminergic network are relatively effective at ameliorating motor deficits, especially in the early stages of the disease, but none of these therapies are curative and many generate their own problems. Recent advances in PD research have demonstrated that gene delivery of trophic factors, glial cell line–derived neurotrophic factor (GDNF) and neurturin, in particular, can provide structural and functional recovery in rodent and nonhuman primate models of PD. Similar success has been gleaned in open‐label clinical trials, although this has yet to be realized in double‐blinded analyses. This work reviews the field of trophic factor gene delivery for PD. © 2013 Movement Disorder Society