bluuebunny/crossref_metadata_2025_split huggingface dataset:
The transmembrane domain of HIV-1 Vpu is sufficient to confer anti-tetherin activity to SIVcpz and SIVgor Vpu proteins: cytoplasmic determinants of Vpu function
Authors: Kluge Silvia F , Sauter Daniel , Vogl Michael , Peeters Martine , Li Yingying , Bibollet-Ruche Frederic , Hahn Beatrice H , Kirchhoff Frank 
Published: March 2013

Abstract

Background
The acquisition of effective Vpu-mediated anti-tetherin activity to promote virion release following transmission of SIVcpzPtt from central chimpanzees (Pan troglodytes troglodytes) to humans distinguishes pandemic HIV-1 group M strains from non-pandemic group N, O and P viruses and may have been a prerequisite for their global spread. Some functional motifs in the cytoplasmic region of HIV-1 M Vpus proposed to be important for anti-tetherin activity are more frequently found in the Vpu proteins of SIVcpzPtt than in those of SIVcpzPts infecting eastern chimpanzees (P. t. schweinfurthii), that have not been detected in humans, and SIVgor from gorillas, which is closely related to HIV-1 O and P. Thus, SIVcpzPtt strains may require fewer adaptive changes in Vpu than SIVcpzPts or SIVgor strains to counteract human tetherin.

Results
To examine whether SIVcpzPtt may only need changes in the transmembrane domain (TMD) of Vpu to acquire anti-tetherin activity, whereas SIVcpzPts and SIVgor may also require changes in the cytoplasmic region, we analyzed chimeras between the TMD of an HIV-1 M Vpu and the cytoplasmic domains of SIVcpzPtt (n = 2), SIVcpzPts (n = 2) and SIVgor (n = 2) Vpu proteins. Unexpectedly, all of these chimeras were capable of counteracting human tetherin to enhance virion release, irrespective of the presence or absence of the putative adaptor protein binding sites and the DSGxxS β-TrCP binding motif reported to be critical for effective anti-tetherin activity of M Vpus. It was also surprising that in three of the six chimeras the gain of anti-tetherin function was associated with a loss of the CD4 degradation activity since this function was conserved among all parental HIV-1, SIVcpz and SIVgor Vpu proteins.

Conclusions
Our results show that changes in the TMD of SIVcpzPtt, SIVcpzPts and SIVgor Vpus are sufficient to render them active against human tetherin. Thus, several previously described domains in the extracellular region of Vpu are not absolutely essential for tetherin antagonism but may be required for other Vpu functions.
BDNF Regulates Atypical PKC at Spinal Synapses to Initiate and Maintain a Centralized Chronic Pain State
Authors: Melemedjian Ohannes K , Tillu Dipti V , Asiedu Marina N , Mandell Edward K , Moy Jamie K , Blute Victoria M , Taylor Caleb J , Ghosh Sourav , Price Theodore J 
Published: March 2013

Background Chronic pain is an important medical problem affecting hundreds of millions of people worldwide. Mechanisms underlying the maintenance of chronic pain states are poorly understood but the elucidation of such mechanisms have the potential to reveal novel therapeutics capable of reversing a chronic pain state. We have recently shown that the maintenance of a chronic pain state is dependent on an atypical PKC, PKMζ, but the mechanisms involved in controlling PKMζ in chronic pain are completely unknown. Here we have tested the hypothesis that brain derived neurotrophic factor (BDNF) regulates PKMζ, and possibly other aPKCs, to maintain a centralized chronic pain state. Results We first demonstrate that although other kinases play a role in the initiation of persistent nociceptive sensitization, they are not involved in the maintenance of this chronic pain state indicating that a ZIP-reversible process is responsible for the maintenance of persistent sensitization. We further show that BDNF plays a critical role in initiating and maintaining persistent nociceptive sensitization and that this occurs via a ZIP-reversible process. Moreover, at spinal synapses, BDNF controls PKMζ and PKCΛ nascent synthesis via mTORC1 and BDNF enhances PKMζ phosphorylaton. Finally, we show that BDNF signaling to PKMζ and PKCΛ is conserved across CNS synapses demonstrating molecular links between pain and memory mechanisms. Conclusions Hence, BDNF is a key regulator of aPKC synthesis and phosphorylation and an essential mediator of the maintenance of a centralized chronic pain state. These findings point to BDNF regulation of aPKC as a potential therapeutic target for the permanent reversal of a chronic pain state.
Clinical balance assessment: perceptions of commonly-used standardized measures and current practices among physiotherapists in Ontario, Canada
Authors: Sibley Kathryn M , Straus Sharon E , Inness Elizabeth L , Salbach Nancy M , Jaglal Susan B 
Published: March 2013

Abstract

Background
Balance impairment is common in multiple clinical populations, and comprehensive assessment is important for identifying impairments, planning individualized treatment programs, and evaluating change over time. However, little information is available regarding whether clinicians who treat balance are satisfied with existing assessment tools. In 2010 we conducted a cross-sectional survey of balance assessment practices among physiotherapists in Ontario, Canada, and reported on the use of standardized balance measures (Sibley et al. 2011 Physical Therapy; 91: 1583-91). The purpose of this study was to analyse additional survey data and i) evaluate satisfaction with current balance assessment practices and standardized measures among physiotherapists who treat adult or geriatric populations with balance impairment, and ii) identify factors associated with satisfaction.

Methods
The questionnaire was distributed to 1000 practicing physiotherapists. This analysis focuses on questions in which respondents were asked to rate their general perceptions about balance assessment, the perceived utility of individual standardized balance measures, whether they wanted to improve balance assessment practices, and why. Data were summarized with descriptive statistics and utility of individual measures was compared across clinical practice areas (orthopaedic, neurological, geriatric or general rehabilitation).

Results
The questionnaire was completed by 369 respondents, of which 43.4% of respondents agreed that existing standardized measures of balance meet their needs. In ratings of individual measures, the Single Leg Stance test and Berg Balance Scale were perceived as useful for clinical decision-making and evaluating change over time by over 70% of respondents, and the Timed Up-and-Go test was perceived as useful for decision-making by 56.9% of respondents and useful for evaluating change over time by 62.9% of respondents, but there were significant differences across practice groups. Seventy-nine percent of respondents wanted to improve their assessments, identifying individual, environmental and measure-specific barriers. The most common barriers were lack of time and knowledge.

Conclusions
This study offers new information on issues affecting the evaluation of balance in clinical settings from a broad sample of physiotherapists. Continued work to address barriers by specific practice area will be critical for the success of any intervention attempting to implement optimal balance assessment practices in the clinical setting.
Prospective evaluation of quality of life 54 months after high-dose intensity-modulated radiotherapy for localized prostate cancer
Authors: Goineau Aurore , Marchand Virginie , Rigaud Jérome , Bourdin Sylvain , Rio Emmanuel , Campion Loic , Bonnaud-Antignac Angélique , Mahé Marc-André , Supiot Stéphane 
Published: March 2013

Abstract

Objective
To determine late toxicity and quality of life (QoL) in patients with localized prostate cancer after high-dose intensity-modulated radiotherapy (IMRT).

Patient and methods
This was a prospective study in patients with localized prostate adenocarcinoma who had been treated by IMRT (76 Gy) between February and November 2006. Physicians scored acute and late toxicity using the Common Terminology Criteria for Adverse Events (version 3.0). Patients completed cancer and prostate-specific QoL questionnaires (EORTC QLQ-C30 and QLQ-PR25) before IMRT (baseline) and at 2, 6, 18 and 54 months.

Result
Data were available for 38 patients (median age, 73 years) (18% low risk; 60% intermediate risk; 32% high risk). The incidence of urinary and gastrointestinal toxicity was respectively: immediately post IMRT: 36.8% and 23.7% (grade 1), 5.3% and 5.3% (grade 2), 2.6% and 0% (grade 3); at 18 months: 23.7% and 10.3% (grade 1), 26.3% and 13.2% (grade 2), 0% and 2.6% (grade 3); at 54 months: 34.2% and 23.7% (grade 1), 5.3% and 15.8% (grade 2), 5.3% and 0% (grade 3). At 54 months, significant worsening was reported by patients for 11/19 QoL items but the worsening was clinically relevant (>10 points) for 7 items only: physical, role as well as social functioning, fatigue, pain, dyspnoea and constipation. There was no significant difference between 54-month and baseline QoL scores for global health, gastrointestinal symptoms, treatment-related symptoms and sexual function. However, there was significant - but clinically non-relevant (<10 points) - worsening of urinary symptom.

Conclusion
High-dose IMRT to the prostate with accurate patient positioning did not induce any clinically relevant worsening in late urinary and gastrointestinal QoL at 54 months. Impaired physical and role functioning may be related to age and comorbidities.
In vivo and in silico analysis of PCNA ubiquitylation in the activation of the Post Replication Repair pathway in S. cerevisiae
Authors: Amara Flavio , Colombo Riccardo , Cazzaniga Paolo , Pescini Dario , Csikász-Nagy Attila , Falconi Marco Muzi , Besozzi Daniela , Plevani Paolo 
Published: March 2013

Abstract

Background
The genome of living organisms is constantly exposed to several damaging agents that induce different types of DNA lesions, leading to cellular malfunctioning and onset of many diseases. To maintain genome stability, cells developed various repair and tolerance systems to counteract the effects of DNA damage. Here we focus on Post Replication Repair (PRR), the pathway involved in the bypass of DNA lesions induced by sunlight exposure and UV radiation. PRR acts through two different mechanisms, activated by mono- and poly-ubiquitylation of the DNA sliding clamp, called Proliferating Cell Nuclear Antigen (PCNA).

Results
We developed a novel protocol to measure the time-course ratios between mono-, di- and tri-ubiquitylated PCNA isoforms on a single western blot, which were used as the wet readout for PRR events in wild type and mutant S. cerevisiae cells exposed to acute UV radiation doses. Stochastic simulations of PCNA ubiquitylation dynamics, performed by exploiting a novel mechanistic model of PRR, well fitted the experimental data at low UV doses, but evidenced divergent behaviors at high UV doses, thus driving the design of further experiments to verify new hypothesis on the functioning of PRR. The model predicted the existence of a UV dose threshold for the proper functioning of the PRR model, and highlighted an overlapping effect of Nucleotide Excision Repair (the pathway effectively responsible to clean the genome from UV lesions) on the dynamics of PCNA ubiquitylation in different phases of the cell cycle. In addition, we showed that ubiquitin concentration can affect the rate of PCNA ubiquitylation in PRR, offering a possible explanation to the DNA damage sensitivity of yeast strains lacking deubiquitylating enzymes.

Conclusions
We exploited an in vivo and in silico combinational approach to analyze for the first time in a Systems Biology context the events of PCNA ubiquitylation occurring in PRR in budding yeast cells. Our findings highlighted an intricate functional crosstalk between PRR and other events controlling genome stability, and evidenced that PRR is more complicated and still far less characterized than previously thought.
Cohesin codes – interpreting chromatin architecture and the many facets of cohesin function
Authors: Rudra Soumya , Skibbens Robert V. 
Published: March 2013

Summary
Sister chromatid tethering is maintained by cohesin complexes that minimally contain Smc1, Smc3, Mcd1 and Scc3. During S-phase, chromatin-associated cohesins are modified by the Eco1/Ctf7 family of acetyltransferases. Eco1 proteins function during S phase in the context of replicated sister chromatids to convert chromatin-bound cohesins to a tethering-competent state, but also during G2 and M phases in response to double-stranded breaks to promote error-free DNA repair. Cohesins regulate transcription and are essential for ribosome biogenesis and complete chromosome condensation. Little is known, however, regarding the mechanisms through which cohesin functions are directed. Recent findings reveal that Eco1-mediated acetylation of different lysine residues in Smc3 during S phase promote either cohesion or condensation. Phosphorylation and SUMOylation additionally impact cohesin functions. Here, we posit the existence of a cohesin code, analogous to the histone code introduced over a decade ago, and speculate that there is a symphony of post-translational modifications that direct cohesins to function across a myriad of cellular processes. We also discuss evidence that outdate the notion that cohesion defects are singularly responsible for cohesion-mutant-cell inviability. We conclude by proposing that cohesion establishment is linked to chromatin formation.
Price Shopping in Consumer-Directed Health Plans
Authors: Sood Neeraj , Wagner Zachary , Huckfeldt Peter , Haviland Amelia M. 
Published: March 2013

Abstract
We use health insurance claims data from 63 large employers to estimate the extent of price shopping for nine common outpatient services in consumer-directed health plans (CDHPs) compared to traditional health plans. The main measures of price shopping include (1) the total price paid on the claim, (2) the share of claims from low- and high-cost providers, and (3) the savings from price shopping relative to choosing prices randomly. All analyses control for individual and zip code level demographics and plan characteristics. We also estimate differences in price shopping within CDHPs depending on expected health care costs and whether the service was bought before or after reaching the deductible. For eight out of nine services analyzed, prices paid by CDHP and traditional plan enrollees did not differ significantly; CDHP enrollees paid 2.3% less for office visits. Similarly, office visits was the only service where CDHP enrollment resulted in a significantly larger share of claims from low-cost providers and greater savings from price shopping relative to traditional plans. There was also no evidence that, within CDHP plans, consumers with lower expected medical expenses exhibited more price shopping or that consumers exhibited more price shopping before reaching the deductible.
Effect of Equivalent Sites on the Dynamics of Bimetallic Nanoparticles
Authors: Fernández-Navarro C. , Gutiérrez-Esparza A. J. , Montejano-Carrizales J.M. , Mejía-Rosales S.J. 
Published: March 2013

ABSTRACTUsing a Sutton and Chen interatomic potential, we study the molecular dynamics of Au-Pd nanoparticles with an initial icosahedral structure at different temperatures and concentrations, where each relative concentration of the 561-atom particles was made by placing atoms of the same species at equivalent sites, in order to identify under which conditions the melting transition temperature appears for each particle. In addition, we compute global order parameters in order to correlate the obtained results with the caloric curves of each particle. As a result, we observe that the melting transition temperature depends on the relative atomic positions of gold and palladium. The melting transition temperature of the Au-Pd alloy particles appears at higher temperature than that of the pure-gold particle. From the analysis of the structure of the particles, we found that the melting temperature increases with the proportion of gold atoms, and for those particles with a higher concentration of palladium on the surface, we observe an early migration of gold atoms before the melting transition temperature appears.
Synthesis and Characterization of Alloys and Bimetallic Nanoparticles of CuNi Prepared by Sol-Gel Method
Authors: de León-Quiroz E.L. , Obregón D. Vázquez , Pedraza A. Ponce , Larios-Rodríguez E. , José-Yacaman M. , García-Cerda L.A. 
Published: March 2013

ABSTRACTRecently, bimetallic nanostructures and nanoalloys have received special interest due to their promising chemical and physical properties. Specifically, Cu-Ni nanoparticles have been investigated for biomedical and catalytic applications. This work reports the synthesis of alloys and bimetallic nanoparticles of CuxNi100-x(x = 20, 40, 50, 60 and 80) by sol-gel method, and their morphological, structural and magnetic characterization. A precursor material was prepared using a standard Pechini method and then CuNi nanoparticles were obtained by calcination treatments of the precursor in H2/N2atmosphere at 600 and 700°C for 15 minutes. The resulting nanoparticles were characterized by X-ray diffraction (XRD), which reveals that this method led to the formation of CuNi substitutional nanoalloys and bimetallic nanoparticles with good cristallinity related with the calcination temperatures and Cu:Ni weight ratios. Transmission electron microscopy (TEM) shows nearly monodisperse and uniform spherical nanoparticles with sizes between 40 and 70 nm. The magnetic properties were studied using SQUID magnetometry, according with these results, the CuNi nanoparticles showed a ferromagnetic behavior, the magnetization value increases as a function of the weight percentage of Ni.
Preparation of Polymer Nanocomposites with Enhanced Antimicrobial Properties
Authors: España-Sánchez Beatriz L. , Ávila-Orta Carlos A. , Neira-Velázquez Maria G. , Solís-Rosales Silvia G. , González -Morones Pablo 
Published: March 2013

ABSTRACTPlasma surface activation and antibacterial properties of nanocomposites of polypropylene/silver nanoparticles (PP/nAg) and nylon-6/silver nanoparticles (Ny6/nAg) were investigated. The nanocomposites were prepared by melt blending assisted by ultrasound, while surface activation was achieved by means of argon plasma. To evaluate the antimicrobial properties of the nanocomposites, pathogen microorganisms such as Pseudomonas aeruginosa and Aspergillus niger were tested. Scanning Electron Microscopy (SEM) analyses showed a uniform dispersion of nanoparticles within the polymer matrix, though the presence of some agglomerates was also appreciated. On the other hand, surface topography by Atomic Force Microscopy (AFM) suggested that ions from the argon plasma generated ion collisions with the surface of the nanocomposites removing or etching polymer from surface and improving silver nanoparticles exposure, increasing their antimicrobial properties as corroborated by antimicrobial analyses. Nanocomposites exposed to argon plasma presented higher antimicrobial properties than the ones not exposed. These results indicated that plasma treatment increased the contact area of the nanoparticles with the microorganisms and enhanced the antimicrobial properties of nanocomposites. The results also showed that PP/nAg nanocomposites presented higher bacterial inhibition than Ny6/nAg nanocomposites, indicating that the chemical structure of the polymer also plays a big role in the final performance of the composite.
Effect of the Nucleation Layer on TiO2 Nanoflowers Growth via Solvothermal Synthesis
Authors: Jaramillo Oscar A. , Raman Reshmi , Rincón Marina E. 
Published: March 2013

ABSTRACTTiO2 nanoflowers were obtained on modified ITO substrates by solvothermal synthesis. Surface modification was achieved with a layer of TiO2 seeds/nucleus obtained by dip-coating at various pH and dip cycles. Field emission scanning electron microscopy results indicated that at all nucleation conditions there was a dual population of TiO2 nanoparticles and nanoflowers. For a particular pH, the effect of increasing the number of dips was to increase the size and number of the nanoflowers, whereas for a fixed number of dips, the increase in pH causes a decrease in nanoflower population. The comparison with solvothermal films obtained on unmodified substrates indicates that TiO2 nanoflowers grew up on the nucleation sites. These microstructural changes determine the active surface area and sensing properties of the solvothermal films. At room temperature, no evidence of superior ethanol sensing properties was found for TiO2 nanoflowers, which show larger resistivity than TiO2 nanoparticles.
Computational Fluid Dynamics in the Carbon Nanotubes Synthesis by Chemical Vapor Deposition
Authors: Sánchez Alejandro Gómez , Lvova Lada Domratcheva , Garza Víctor López , Doval Ramón Román , Sánchez María de Lourdes Mondragón 
Published: March 2013

ABSTRACTIn this paper, an experimental study aimed at achieving better control of the deposition patterns of carbon nanotubes (CNTs) is presented. CNTs were grown on a long of reactor by the catalytic chemical vapor deposition (CVD) of a benzene/ferrocene solution at 1073 K. The deposition patterns on the substrate were controlled for process times and carrier gas flow rates. In order to investigate the reaction mechanism and production rate for the growth of CNTs in catalyst CVD, computational fluid dynamics (CFD) model was developed in this study. Then the computational model was integrated with the dynamic model to optimize the process parameters formulating a correlation between turbulence, deposition rate for the growth of carbon nanotubes and parameters as process time and carrier gas flow rate. Scanning electron microscopes (SEM) are used to characterize carbon nanotubes products.
Synthesis and Electrical Properties of Garnet-type Solid Oxide Electrolyte Thin Films from Solution Route
Authors: Matsuda Hirofumi , Hosono Eiji , Zhou Haoshen 
Published: March 2013

ABSTRACTDevelopment of Al-stabilized Li7La3Zr2O12 (LLZO) fast Li ion conducting thin films was attempted by chemical solution deposition (CSD) method with the nominal composition of Li5.95Al0.35La3Zr2O12. The films were crystallized at 600°C on Pt-coated Si substrates in almost single phase without a preferred orientation to any crystallographic axis. Subsequent thermal annealing at 760°C improved packing of LLZO grains with the film thickness of 1.1μm. AC impedance measurements were conducted both with Li reversible and Au blocking microelectrodes deposited on the films annealed at 760°C. Total Li ion conductivity σtotal comprised of bulk and grain boundary contribution was studied. The temperature dependence of σtotal was described with single thermal activation process and σtotal∼2x10-5 S/cm and activation energy of Ea=0.58eV were estimated. These values may be attributed to tetragonal modification of LLZO crystal.
Flexible Fast Lithium Ion Conducting Ceramic Electrolyte
Authors: Hamamoto Koichi , Matveev Danila , Yamaguchi Toshiaki , Sumi Hirofumi , Suzuki Toshio , Bredikhin Sergey , Fujishiro Yoshinobu 
Published: March 2013

ABSTRACTLarge-area fast lithium ion conducting ceramic thin freestanding sheets was successfully prepared using a sheet forming technique. This ceramic sheet contains the crystalline phase of Li1+x+yAlxTi2-xSiyP3-yO12 with the NASICON type structure. The ceramic sheet showed maximum overall conductivity over 10−3 S cm−1 at room temperature. And, the developed thin ceramic sheet has sufficient flexibility against bending stress. Because a thin large-area ceramic electrolyte sheet was prepared using less energy compared with a conventional glass casting method, it is suitable for practical use.