bluuebunny/crossref_metadata_2025 huggingface dataset:
A mutated glucagon-like peptide-1 with improved glucose-lowering activity in diabetic mice
Authors: Gao Mingming , Tong Yue , Gao Xiangdong , Yao Wenbing
Published: November 2012

Objectives

The aim of this study was to characterize the conformation and potency of a mutated glucagon-like peptide-1 (mGLP-1), and evaluate its glucose-lowering activity in diabetic mice.

Methods

Spectroscopy techniques were employed to characterize the conformation of mGLP-1. Glucose tolerance test was performed to determine the potency of mGLP-1 in vivo. A mouse model in which diabetes was induced by multiple low doses of streptozotocin was established to evaluate the glucose-lowering activity of mGLP-1.

Key findings

Compared with native GLP-1, mGLP-1 had a similar conformation and an enhanced potency in vivo. In diabetic mice, mGLP-1 displayed a significantly improved glucose-lowering activity as judged by fasting glucose and insulin, oral glucose tolerance test, beta cell function analysis and histochemical analysis.

Conclusions

Collectively, mGLP-1 possesses an improved glucose-lowering activity in vivo and therefore can be recognized as a potential candidate for the future development of anti-diabetic drugs.
Maternal mental health and infant dietary patterns in a statewide sample ofMarylandWICparticipants
Authors: Hurley Kristen M. , Black Maureen M. , Merry Brian C. , Caulfield Laura E.
Published: November 2012

The study's objective was to examine the relation between maternal mental health and infant dietary intake. A cross‐sectional, population‐based telephone survey was employed within a statewide sample ofMarylandSpecialSupplementalNutritionProgram forWomen,Infants andChildren participants. A 24‐h diet recall was performed using theUnitedStatesDepartment ofAgricultureAutomatedMultiple‐PassMethod. Analyses presented were based on 689 mother–infant pairs. Overall, 36.5% of mothers reported introducing solids to their infants early (<4 months of age), and 40% reported adding cereal to their infant's bottle. Among 0–6‐month‐old infants, higher infant energy intake was associated with symptoms of maternal stress [β = 0.02; confidence interval (CI): 0.01, 0.04], depression (β = 0.04;CI: 0.01, 0.06) and overall maternal psychological distress (β = 0.02;CI: 0.003, 0.03). With early introduction of solids in the model, the significant associations between infant energy intake and maternal stress and maternal psychological distress became marginal (P‘s = 0.06–0.10). The association between infant energy intake and maternal depression remained significant (β = 0.03;CI: 0.01, 0.06). Among 4–6‐month‐old infants, intakes of breads and cereals were higher among mothers who reported more symptoms of stress (β = 0.12;CI: 0.04, 0.23), depression (β = 0.19;CI: 0.03, 0.34), anxiety (β = 0.15;CI: 0.02, 0.27) and overall psychological distress (β = 0.04;CI: 0.01, 0.07). Among 7–12‐month‐old infants, dietary intake was not related to mental health symptoms. Findings suggest poorer infant feeding practices and higher infant dietary intake during the first 6 months of age in the context of maternal mental health symptoms. Further research is needed to evaluate these effects on child dietary habits and growth patterns over time.
The Importance of Social Cues for Discretionary Health Services Utilization: The Case of Infertility
Authors: Greil Arthur L. , Shreffler Karina M. , Johnson Katherine M. , McQuillan Julia , Slauson‐Blevins Kathleen
Published: November 2012

Infertility is a discretionary health condition; although it carries with it important life course implications, treatment is rarely necessary for health reasons. Sociological theories of medical help‐seeking emphasize demographic factors, perceived need, and enabling conditions in health services utilization, but we find that social cues are also strongly associated with health services utilization for infertility. Adjusted for conventional predictors of medical help‐seeking, several social cue indicators have significant associations with utilization, including having friends and family with children, perceiving infertility stigma, and having a partner and/or family member who encourages treatment. Perceived need accounts for the largest portion of the variation in utilization. Enabling conditions explain less of the variance than social cues. Social cues should be especially important for discretionary health services utilization. Studies of service utilization for discretionary health conditions should explicitly incorporate a range of measures of social cues into their models.
Specialized functions of the PP2A subfamily II catalytic subunits PP2A‐C3 and PP2A‐C4 in the distribution of auxin fluxes and development in Arabidopsis
Authors: Ballesteros Isabel , Domínguez Teresa , Sauer Michael , Paredes Pilar , Duprat Anne , Rojo Enrique , Sanmartín Maite , Sánchez‐Serrano Jose J.
Published: November 2012

Protein phosphorylation is a key molecular switch used to transmit information in biological signalling networks. The output of these signalling circuits is governed by the counteracting activities of protein kinases and phosphatases that determine the direction of the switch. Whereas many kinases have been functionally characterized, it has been difficult to ascribe precise cellular roles to plant phosphatases, which are encoded by enlarged gene families that may provide a high degree of genetic redundancy. In this work we have analysed the role in planta of catalytic subunits of protein phosphatase 2A (PP2A), a family encoded by five genes in Arabidopsis. Our results indicate that the two members of subfamily II, PP2A‐C3 and PP2A‐C4, have redundant functions in controlling embryo patterning and root development, processes that depend on auxin fluxes. Moreover, polarity of the auxin efflux carrier PIN1 and auxin distribution, determined with the DR5pro:GFP proxy, are affected by mutations in PP2A‐C3 and PP2A‐C4. Previous characterization of mutants in putative PP2A regulatory subunits had established a link between this class of phosphatases and PIN dephosphorylation and subcellular distribution. Building on those findings, the results presented here suggest that PP2A‐C3 and PP2A‐C4 catalyse this reaction and contribute critically to the establishment of auxin gradients for proper plant development.
Gasification of Biomass to Second Generation Biofuels: A Review
Authors: Matas Güell Berta , Sandquist Judit , Sørum Lars
Published: November 2012

Biomass gasification has gained significant attention in the last couple of decades for the production of heat, power, and second generation biofuels. Biomass gasification processes are highly complex due to the large number of reactions involved in the overall process as well as the high sensitivity of the process to changes in the operational conditions. This report reviews the state-of-the-art of biomass gasification by evaluating key process parameters such as gasifying agent, temperature, pressure, particle size, etc., for fluidized bed and entrained flow gasifiers. The pros and cons of each technology and the remaining bottlenecks are also addressed.
Computational Study of Edge Cooling for Open-Cathode Polymer Electrolyte Fuel Cell Stacks
Authors: Sasmito Agus P. , Shamim Tariq , Birgersson Erik , Mujumdar Arun S.
Published: November 2012

In open-cathode polymer electrolyte fuel cell (PEFC) stacks, a significant temperature rise can exist due to insufficient cooling, especially at higher current densities. To improve stack thermal management while reducing the cost of cooling, we propose a forced air-convection open-cathode fuel cell stack with edge cooling (fins). The impact of the edge cooling is studied via a mathematical model of the three-dimensional two-phase flow and the associated conservation equations of mass, momentum, species, energy, and charge. The model includes the stack, ambient, fan, and fins used for cooling. The model results predict better thermal management and stack performance for the proposed design as compared to the conventional open-cathode stack design, which shows potential for practical applications. Several key design parameters—fin material and fin geometry—are also investigated with regard to the stack performance and thermal management.
Seal Leakage Effects on the Electrical Performance of an SOFC Button Cell
Authors: DiGiuseppe Gianfranco
Published: November 2012

This paper reports a new study where leakages through a seal in a solid oxide fuel cell (SOFC) button cell is investigated in detail. A 2D model is used to determine different flow characteristics of the leakages and its effects on the cell performance. The leakage effects on the performance are studied at different seal porosities, and other parameters are also investigated. The results of this investigation indicate that a seal leakage can affect the cell performance significantly if the leak comes from outside the test rig. That is, an air leak must be present through the seal and must flow into the anode chamber, where then it affects negatively the cell performance. In addition, the model developed here can be used to include leakages in stack modeling studies.
An Aerodynamic Investigation of an Isolated Rotating Formula 1 Wheel Assembly
Authors: Axerio-Cilies John , Iaccarino Gianluca
Published: November 2012

The flowfield around a 60% scale rotating Formula 1 tire in contact with the ground in a closed wind tunnel at a Reynolds number of 500,000 was examined computationally and experimentally. The goal of this study was to assess the accuracy of unsteady Reynolds-averaged Navier–Stokes (URANS) equations and confirm the existence of large scale vortical and flow recirculating features. A replica deformable F1 tire model that includes four tire treads and all brake components was used to determine the sensitivity of the wake to cross flow within the tire hub as well as the flow blockage caused by the brake assembly. Several turbulence closures were employed and the one that matched closest to the experimental PIV data was the Reynolds stress model. The variability between the six turbulence closures is shown by comparing velocity profiles, pressure distributions, and vortex eccentricity. The sensitivity of the wake to four different hub geometries, contact patch boundary conditions, multiple reference frame (MRF) rotor and spoke treatment, and time step size are also discussed.
Dependency on Runner Geometry for Reversible-Pump Turbine Characteristics in Turbine Mode of Operation
Authors: Olimstad Grunde , Nielsen Torbjørn , Børresen Bjarne
Published: November 2012

Characteristics of a reversible-pump turbine have been measured with five different leading edge profiles in turbine mode. These profiles varied the inlet blade angle and the radius of curvature. Further geometry parameters have been investigated through numerical simulations. The pump turbine tested has much steeper flow-speed characteristics than a comparable Francis turbine. The most obvious geometry difference is the inlet part of the runner blades, where the blade angle for the pump turbine is much smaller than for the Francis turbine. Two different blade angles have been tested on a physical model and computational fluid dynamics (CFD) simulations have been performed on four different angles. Both methods show that a smaller blade angle gives less steep characteristics in turbine mode, whereas the measured s-shape in turbine brake- and turbine pumping mode gets more exaggerated. Long-radius leading edges result in less steep characteristics. The unstable pump turbine characteristics are in the literature shown to be a result of vortex formation in the runner and guide vane channels. A leading edge with longer curvature radius moves the formation of vortices towards higher speed of rotation.
Numerical Simulation of Emergency Shutdown Process of Ring Gate in Hydraulic Turbine Runaway
Authors: Xiao Juliang , Zhu Enqiang , Wang Guodong
Published: November 2012

A numerical model that considers the interaction between the ring gate and its neighboring components was used to simulate the emergency shutdown process of a ring gate in hydraulic turbine runaway. The three-dimensional, unsteady Navier–Stokes equations with renormalization group (RNG) k-ε turbulence models, multiphase flow models, dynamic mesh, and sliding mesh technology were applied to model the entire flow passage of the Francis hydraulic turbine, including the spiral case, stay vanes, ring gate, guide vanes, runner, and draft tube. We present a detailed analysis on the working conditions of the turbine during its runaway quitting process, the inside and outside surface pressure distributions of the ring gate, the pressure and velocity distributions of the spiral case, stay vanes, and guide vanes at different gate openings, and the loading condition of the ring gate during its closing process. The theoretical basis for improving the dynamic quality of the transient process and for hydraulic designing and optimization is provided by analyses.
Advanced Imaging of Elementary Circuits
Authors: Baird William H. , Richards Caleb , Godbole Pranav
Published: November 2012

Students commonly find the second semester of introductory physics to be more challenging than the first, probably due to the mechanical intuition we acquire just by moving around. For most students, there is no similar comfort with electricity or magnetism. In an effort to combat this confusion, we decided to examine simple electric circuits with either a high-speed camera or a thermal imager in an effort to make things like current and voltage as familiar as slow motion or temperature.
GPRC5B Activates Obesity-Associated Inflammatory Signaling in Adipocytes
Authors: Kim Yeon-Jeong , Sano Takamitsu , Nabetani Takuji , Asano Yoshimi , Hirabayashi Yoshio
Published: November 2012

Mice lacking an orphan G protein–coupled receptor show reduced inflammatory signaling and obesity.
SUMOylation Silences Heterodimeric TASK Potassium Channels Containing K2P1 Subunits in Cerebellar Granule Neurons
Authors: Plant Leigh D. , Zuniga Leandro , Araki Dan , Marks Jeremy D. , Goldstein Steve A. N.
Published: November 2012

Potassium channels that respond to acidification and the anesthetic halothane become electrically silenced when SUMOylated.
Limited Activity of Miltefosine in Murine Models of Cryptococcal Meningoencephalitis and Disseminated Cryptococcosis
Authors: Wiederhold Nathan P. , Najvar Laura K. , Bocanegra Rosie , Kirkpatrick William R. , Sorrell Tania C. , Patterson Thomas F.
Published: November 2012

Miltefosine is an alkyl phosphocholine with good oral bioavailability and
in vitro
activity against
Cryptococcus
species that has gained interest as an additional agent for cryptococcal infections. Our objective was to further evaluate the
in vivo
efficacy of miltefosine in experimental
in vivo
models of cryptococcal meningoencephalitis and disseminated cryptococcosis. Mice were infected intracranially or intravenously with either
C. neoformans
USC1597 or H99. Miltefosine treatment (1.8 to 45 mg/kg of body weight orally once daily) began at either 1 h or 1 day postinoculation. Fluconazole (10 mg/kg orally twice daily) or amphotericin B deoxycholate (3 mg/kg intraperitoneally once daily) served as positive controls. In our standard models, miltefosine did not result in significant improvements in survival or reductions in fungal burden against either
C. neoformans
isolate. There was a trend toward improved survival with miltefosine at 7.2 mg/kg against disseminated cryptococcosis with the H99 strain but only at a low infecting inoculum. In contrast, both fluconazole and amphotericin B significantly improved survival in mice with cryptococcal meningoencephalitis and disseminated cryptococcosis due to USC1597. Amphotericin B also improved survival against both cryptococcal infections caused by H99. Combination therapy with miltefosine demonstrated neither synergy nor antagonism in both models. These results demonstrate limited efficacy of miltefosine and suggest caution with the potential use of this agent for the treatment of
C. neoformans
infections.
Anthelmintic Avermectins Kill Mycobacterium tuberculosis, Including Multidrug-Resistant Clinical Strains
Authors: Lim Leah E. , Vilchèze Catherine , Ng Carol , Jacobs William R. , Ramón-García Santiago , Thompson Charles J.
Published: November 2012

Avermectins are a family of macrolides known for their anthelmintic activities and traditionally believed to be inactive against all bacteria. Here we report that members of the family, ivermectin, selamectin, and moxidectin, are bactericidal against mycobacterial species, including multidrug-resistant and extensively drug-resistant clinical strains of
Mycobacterium tuberculosis
. Avermectins are approved for clinical and veterinary uses and have documented pharmacokinetic and safety profiles. We suggest that avermectins could be repurposed for tuberculosis treatment.
Comparing the validity of the Modified Modified Ashworth Scale (MMAS) and the Modified Tardieu Scale (MTS) in the assessment of wrist flexor spasticity in patients with stroke: protocol for a neurophysiological study
Authors: Abolhasani Hamid , Ansari Noureddin Nakhostin , Naghdi Soofia , Mansouri Korosh , Ghotbi Nastaran , Hasson Scott
Published: November 2012

Introduction

Reliable and valid tools must be used to assess spasticity in clinical practise and research settings. There is a paucity of literature regarding the validity of the Modified Modified Ashworth Scale (MMAS) and the Modified Tardieu Scale (MTS). No study, to date, has been performed to compare the validity of the MMAS and the MTS. This neurophysiological study protocol will compare the validity of the MMAS and the MTS in the assessment of poststroke wrist flexor spasticity.

Methods and analysis

Thirty-two patients with stroke from the University Rehabilitation clinics will be recruited to participate in this cross-sectional, non-interventional study. All measurements will be taken in the Physical Medicine and Rehabilitation Department of Shafa University Hospital in Tehran, Iran. First, wrist flexor spasticity will be assessed clinically using the MMAS and MTS. The tests will be applied randomly. For the MTS, the components of R1, R2, R2−R1 and quality of muscle reaction will be measured. Second, neurophysiological measures of H-reflex latency, Hmax/Mmaxratio, Hslpand Hslp/Mslpratio will be collected from the affected side. The results will be analysed using Spearman's ρ test or Pearson's correlation test to determine the validity of the MMAS and the MTS as well as to compare the validity between the MMAS and the MTS.

Ethics and dissemination

The Research Council, School of Rehabilitation and the Ethics Committee of Tehran University of Medical Sciences (TUMS) approved the study protocol.  The study results will be disseminated in peer-reviewed publications and presented at international congresses.
Life event stress and chronic obstructive pulmonary disease (COPD): associations with mental well-being and quality of life in a population-based study
Authors: Lu Yanxia , Nyunt Ma Shwe Zin , Gwee Xinyi , Feng Liang , Feng Lei , Kua Ee Heok , Kumar Rajeev , Ng Tze Pin
Published: November 2012

Objectives

To investigate whether life event stress was associated with greater psychological distress and poorer quality of life in older individuals with chronic obstructive pulmonary disease (COPD), in comparison with their counterparts without COPD.

Design

Cross-sectional study.

Participants

A population-based sample (N=497) of individuals aged 65 and above with COPD (postbronchodilatation FEV1/FVC<0.70, N=136) and without COPD (N=277).

Measurements

We measured life event stress, depressive symptoms (GDS, Geriatric Depression Scale), cognitive symptoms and function (CFQ, Cognitive Failures Questionnaire and MMSE, Mini-Mental State Examination), and physical and mental health functional status (SF36-PCS, Physical Health Component Summary and SF36-MCS, Mental Health Component Summary) in participants with and without COPD.

Results

In two-way analysis of variance controlling for potential confounders, life event stress was associated with significant main effects of worse GDS (p<0.001), SF36-PCS (p=0.008) and SF36-MCS scores (p<0.001), and with significant interaction effects on GDS score (p<0.001), SF36-PCS (p=0.045) and SF36-MCS (p=0.034) in participants with COPD, more than in non-COPD participants. The main effect of COPD was found for postbronchodilator FEV1 (p<0.001) and cognitive symptoms (p=0.02).

Conclusions

Our findings indicate that life event stress was associated with more depressive symptoms and worse quality of life in individuals with COPD, much more than in those without COPD. Further studies should explore the role of cognitive appraisal of stress, coping resources and psycho-social support in this relationship.
The PREVENT study: a prospective cohort study to identify mid-life biomarkers of late-onset Alzheimer's disease
Authors: Ritchie Craig W , Ritchie Karen
Published: November 2012

Introduction

Epidemiological studies indicate that significant decreases in the incidence of Alzheimer's disease (AD) may be obtained by targeting multiple middle-age risk factors. However, as dementia is unlikely to be diagnosed for decades, short-term outcome measures are required. AD biomarker changes precede clinical symptoms by many years, but their sensitivity to mid-life change remains unknown.

Methods and analysis

PREVENT is a prospective cohort study examining biomarker status at mid-life in at least 150 individuals genetically at high, medium or low risk of late-onset AD. Participants are children of individuals with or without a diagnosed AD allocated to high, medium and low-risk groups according to parental clinical status and ApoE genotype. The biomarkers examined over 2 years are plasma and CSF Aβ42 amyloid, Tau and pTau, proinflammatory cytokines, acute-phase proteins, medial temporal-lobe atrophy, white matter lesion volume, cognitive performance related to transentorhinal and hippocampal functioning and hypothalamic−pituitary−adrenal and sympathetic axes regulation.

Ethics and dissemination

Detected pathologies are communicated to the participant's general practitioner with their permission. Risk status by genotype would not be revealed. The results of the study would be published in peer-reviewed journals and validated biomarkers used to construct a randomised controlled intervention study.
Eliciting symptoms interpreted as normal by patients with early-stage lung cancer: could GP elicitation of normalised symptoms reduce delay in diagnosis? Cross-sectional interview study
Authors: Brindle Lucy , Pope Catherine , Corner Jessica , Leydon Geraldine , Banerjee Anindo
Published: November 2012

Objectives

To investigate why symptoms indicative of early-stage lung cancer (LC) were not presented to general practitioners (GPs) and how early symptoms might be better elicited within primary care.

Design, setting and participants

A qualitative cross-sectional interview study about symptoms and help-seeking in 20 patients from three south England counties, awaiting resection of LC (suspected or histologically confirmed). Analysis drew on principles of discourse analysis and constant comparison to identify processes involved in interpretation and communication about symptoms, and explain non-presentation.

Results

Most participants experienced health changes possibly indicative of LC which had not been presented during GP consultations. Symptoms that were episodic, or potentially caused by ageing or lifestyle, were frequently not presented to GPs. In interviews, open questions about health changes/symptoms in general did not elicit these symptoms; they only emerged in response to closed questions detailing specific changes in health. Questions using disease-related labels, for example, pain or breathlessness, were less likely to elicit symptoms than questions that used non-disease terminology, such as aches, discomfort or ‘getting out of breath’. Most participants described themselves as feeling well and were reluctant to associate potentially explained, non-specific or episodic symptoms with LC, even after diagnosis.

Conclusions

Patients with early LC are unlikely to present symptoms possibly indicative of LC that they associate with normal processes, when attending primary care before diagnosis. Faced with patients at high LC risk, GPs will need to actively elicit potential LC symptoms not presented by the patient. Closed questions using non-disease terminology might better elicit normalised symptoms.
Updates to the Spectrum/Estimation and Projection Package (EPP) model to estimate HIV trends for adults and children
Authors: Stover John , Brown Tim , Marston Milly
Published: November 2012

Background

The Spectrum and Estimation and Projection Package (EPP) programs are used to estimate key HIV indicators based on HIV surveillance and surveys, programme statistics and epidemic patterns. These indicators include the number of people living with HIV, new infections, AIDS deaths, AIDS orphans, the number of adults and children needing treatment, the need for preventing mother to child transmission (PMTCT) and the impact of antiretroviral treatment on survival.

Methods

The Joint United Nations Programme on HIV and AIDS (UNAIDS) Reference Group on Estimates, Models and Projections regularly reviews new data and information needs and recommends updates to the methodology and assumptions used in Spectrum. The latest updates described here were used in the 2011 round of global estimates.

Results

Spectrum and EPP have now been combined into one software package to enhance ease of use and ensure consistent data and assumptions for the curve fitting and indicator estimations. Major enhancements to the methods include a new adult model that tracks the HIV+ population by CD4 count; new patterns describing child survival by time of infection (perinatally, <6 months, 7–12 months and 12+ months after birth); a more detailed estimate of mother-to-child transmission that includes differential transmission rates by CD4 count of the mother, the effects of incident infections and new prophylaxis options; and new procedures to estimate uncertainty ranges around regional estimates.

Conclusions

The revised model and software facilitate the preparation of new HIV estimates and use new data to address emerging needs for better information on need for treatment among adults and children.
Focusing the HIV response through estimating the major modes of HIV transmission: a multi-country analysis
Authors: Gouws Eleanor , Cuchi Paloma
Published: November 2012

Objective

An increasing number of countries have been estimating the distribution of new adult HIV infections by modes of transmission (MOT) to help prioritise prevention efforts. We compare results from studies conducted between 2008 and 2012 and discuss their use for planning and responding to the HIV epidemic.

Methods

The UNAIDS recommended MOT model helps countries to estimate the proportion of new HIV infections that occur through key transmission modes including sex work, injecting drug use (IDU), men having sex with men (MSM), multiple sexual partnerships, stable relationships and medical interventions. The model typically forms part of a country-led process that includes a comprehensive review of epidemiological data. Recent revisions to the model are described.

Results

Modelling results from 25 countries show large variation between and within regions. In sub-Saharan Africa, new infections occur largely in the general heterosexual population because of multiple partnerships or in stable discordant relationships, while sex work contributes significantly to new infections in West Africa. IDU and sex work are the main contributors to new infections in the Middle East and North Africa, with MSM the main contributor in Latin America. Patterns vary substantially between countries in Eastern Europe and Asia in terms of the relative contribution of sex work, MSM, IDU and spousal transmission.

Conclusions

The MOT modelling results, comprehensive review and critical assessment of data in a country can contribute to a more strategically focused HIV response. To strengthen this type of research, improved epidemiological and behavioural data by risk population are needed.
Trends in HIV prevalence among young people in generalised epidemics: implications for monitoring the HIV epidemic
Authors: Mahy Mary , Garcia-Calleja Jesus Maria , Marsh Kimberly Anne
Published: November 2012

Background

Countries measure trends in HIV incidence to assess the impact of HIV prevention and treatment programmes. Most countries have approximated trends in HIV incidence through modelled estimates or through trends in HIV prevalence among young people (aged 15–24 years) assuming they have recently become sexually active and have thus only been recently exposed to HIV.

Methods

Trends in HIV incidence are described and results are compared using three proxy measures of incidence: HIV prevalence among young women attending antenatal clinics (ANCs) in 22 countries; HIV prevalence among young male and female nationally representative household survey respondents in 14 countries; and modelled estimates of adult (ages 15–49 years) HIV incidence in 26 countries. The significance of changes in prevalence among ANC attendees and young survey respondents is tested.

Results

Among 26 countries, 25 had evidence of some decline in HIV incidence and 15 showed statistically significant declines in either ANC data or survey data. Only in Mozambique did the direction of the trend in young ANC attendees differ from modelled adult incidence, and in Mali and Zambia trends among young men differed from trends in adult incidence. The magnitude of change differed by method.

Conclusions

Trends in HIV prevalence among young people show encouraging declines. Changes in fertility patterns, HIV-infected children surviving to adulthood, and participation bias could affect future proxy measures of incidence trends.
Profile of oxidant and antioxidant activity in prepubertal children related to age, gender, exercise, and fitness
Authors: Llorente-Cantarero Francisco Jesus , Gil-Campos Mercedes , Benitez-Sillero Juan de Dios , Muñoz-Villanueva Maria Carmen , Tasset Inmaculada , Pérez-Navero Juan Luis
Published: November 2012

Tissue damage resulting from oxidative stress induced by a pathological condition might have more serious consequences in children than in adults. Researchers have not yet identified particular markers — alone or in combination with others — of oxidative stress, or their role in pediatric diseases. The aim of this study was to identify gender-based biomarkers for measuring oxidative stress. Oxidative biomarkers were studied in 138 healthy Spanish children (85 boys, 53 girls) 7 to 12 years of age, at the prepubertal (Tanner I) stage, independent of body mass index (BMI), age, fitness (measured by 20-m shuttle run test), and physical activity (measured by participation in an after-school exercise program). The oxidative biomarkers measured were lipid peroxidation products, total nitrites, protein carbonyls, and oxidized glutathione (GSSG). The antioxidant biomarkers measured were total glutathione (TG), reduced glutathione (GSH), superoxide dismutase activity (SOD), and glutathione peroxidase activity. In the study population, height, weight, waist circumference, and BMI were lower in girls than in boys. For oxidative biomarkers, boys had higher levels of protein carbonyl than girls (p < 0.001). In spite of this, girls had higher levels of GSSG (p < 0.001) and TG (p = 0.001), and a lower GSH/GSSG ratio (p < 0.001) than boys. For the antioxidant response, girls had higher levels of SOD (p = 0.002) than boys. All analyses were adjusted for BMI, age, fitness, and physical activity. In conclusion, prepubertal girls had higher oxidative stress than boys, in addition to higher levels of SOD, independent of age, BMI, fitness, and physical activity.
On the nucleation rate for the solidification of metals
Authors: Cahoon J.R.
Published: November 2012

The classical homogeneous nucleation rate theory for the solidification of metals has been in use for over 50 years, but it is almost universally used incorrectly. Because of this, solid–liquid surface energies calculated from nucleation rate theory are also incorrect. Herein, the correct usage of the homogeneous nucleation rate equation for the solidification of metals is presented. It is shown that because of the assumption of thermodynamic equilibrium, the homogeneous nucleation rate cannot be accurately calculated but is likely in the range 1012–1014 s−1. Also, it is shown that the homogeneous nucleation temperature for a pure metal is essentially a material property. Calculations for the solidification of pure Ni are included.
DFT-BASEDAB INITIOSTUDY OF THE ELECTRONIC AND OPTICAL PROPERTIES OF CESIUM BASED FLUORO-PEROVSKITECsMF3(M = CaANDSr)
Authors: HARMEL M. , KHACHAI H. , AMERI M. , KHENATA R. , BAKI N. , HADDOU A. , ABBAR B. , UǦUR Ş. , OMRAN S. BIN , SOYALP F.
Published: November 2012

Density functional theory (DFT) is performed to study the structural, electronic and optical properties of cubic fluoroperovskite AMF3( A = Cs ; M = Ca and Sr ) compounds. The calculations are based on the total-energy calculations within the full-potential linearized augmented plane wave (FP-LAPW) method. The exchange-correlation potential is treated by local density approximation (LDA) and generalized gradient approximation (GGA). The structural properties, including lattice constants, bulk modulus and their pressure derivatives are in very good agreement with the available experimental and theoretical data. The calculations of the electronic band structure, density of states and charge density reveal that compounds are both ionic insulators. The optical properties (namely: the real and the imaginary parts of the dielectric function ε(ω), the refractive index n(ω) and the extinction coefficient k(ω)) were calculated for radiation up to 40.0 eV.
POLYTROPIC AND CHAPLYGIN f(R)-GRAVITY MODELS
Authors: KARAMI K. , KHALEDIAN M. S.
Published: November 2012

We reconstruct different f(R)-gravity models corresponding to the polytropic, standard Chaplygin, generalized Chaplygin, modified Chaplygin and modified variable Chaplygin gas dark energy (DE) models. We also obtain the equation of state (EoS) parameters of the corresponding f(R)-gravity models which describe the accelerated expansion of the universe. We conclude that although the EoS parameters of the obtained f(R)-gravities can behave like phantom or quintessence DE models, they cannot justify the transition from the quintessence state to the phantom regime. Furthermore, the polytropic and Chaplygin f(R)-gravity models in de Sitter space can satisfy the inflation condition.
Effect of Void Volume and Silver Loading on Strain Response of Electrical Resistance in Silver Flakes/Polyurethane Composite for Stretchable Conductors
Authors: Araki Teppei , Sugahara Tohru , Nogi Masaya , Suganuma Katsuaki
Published: November 2012

Silver flakes/polyurethane composites have been reported as promising materials for stretchable conductors that can be easily fabricated by wet spinning or printing and yet have low electrical resistance. However, it is also important to control the effects of strain on electrical resistance: for example, stable electrical resistance over a range of strains would be useful for flexible displays or solar cells, whereas a positive or negative correlation between electrical resistance and strain would be useful for pressure or strain sensors. Here, we show that by controlling the void volume and silver loading, the electrical resistance is kept stable at a low value under deformation or is made to increase or decrease with strain. Cyclic tensile tests confirmed that these three behaviors were repeatable. This simple method for realizing three types of electrical behaviors could be very useful in stretchable electronics.
High Uniformity and High Thermal Stability of Solution-Processed Polycrystalline Thin Films by Utilizing Highly Ordered Smectic Liquid Crystals
Authors: Iino Hiroaki , Kobori Takeo , Hanna Jun-ichi
Published: November 2012

We have investigated the fabrication of polycrystalline thin films of a liquid crystalline benzothienobenzothiophene derivative, i.e., 2-octylthienyl-benzothienobenzothiophene having a highly ordered smectic liquid crystal phase (SmE), the thermal stability of the films, and the performance of their field effect transistors (FETs). The polycrystalline thin films spin-coated at a temperature of SmE phase exhibited uniform textures and were molecularly flat. The FETs after solvent vapor anneal showed the high FET mobility of 1.1 cm2 V-1 s-1, while as-fabricated FETs did the low FET mobility of ca. 10-3 cm2 V-1 s-1. In addition, the thermal stability of the films improved up to 180 °C without melting. After thermal stress at 150 °C for 5 min, the FETs exhibited low mobility as in the as-fabricated FETs but they recovered to the high FET mobility of 1.0 cm2 V-1 s-1 after additional anneals. We compared these results with those of dialkyl benzothienobenzothiophene derivatives and discussed the role of highly ordered liquid crystal phase.
Solution-Processed C60 Single-Crystal Field-Effect Transistors
Authors: Kang Woogun , Kitamura Masatoshi , Itoh Tetsuji , Arakawa Yasuhiko
Published: November 2012

We have demonstrated high mobility C60 single-crystal field-effect transistors formed by a solution process. 1,2,4-Trichlorobenzene (TCB) C60 solution formed plate like crystals with sizes exceeding 500 µm. We found that the C60 single crystals prepared from solution consist of two TCB molecules per C60 molecule, with a triclinic crystal structure. TCB molecules in C60 crystals are extracted by an annealing process, and the crystal structure was changed to a face-centered-cubic structure. The C60 single crystal prepared from TCB solution showed typical n-channel operation and high electron mobilities of up to 1.4 cm2 V-1 s-1.
Selective-Area Growth and Electrical Characterization of Hybrid Structures between Semiconducting GaAs Nanowires and Ferromagnetic MnAs Nanoclusters
Authors: Hara Shinjiro , Sakita Shinya , Yatago Masatoshi
Published: November 2012

We report on the structural and electrical characterizations of MnAs/GaAs hybrid nanowires fabricated by combining selective-area metal–organic vapor phase epitaxy of undoped GaAs nanowires and endotaxial nanoclustering of MnAs. As a result of endotaxy, MnAs nanoclusters are typically embedded in the six ridges of hexagonal GaAs nanowires. However, the MnAs nanoclusters are formed not only at the six ridges, but on the surfaces of six 01̄1 facets of hexagonal GaAs nanowires, when we decrease the growth temperature from 600 to 400 °C. From the cross-sectional characterizations by transmission electron microscopy, the size and density of the MnAs nanoclusters formed at the top part of the GaAs nanowires are much larger than those formed at the bottom part of the nanowires. Current and voltage characteristics of MnAs/GaAs hybrid nanowires are investigated using two-terminal device structures of free-standing hybrid nanowires. The hybrid nanowires formed on Zn-doped p-type GaAs (111)B substrates show ohmic characteristics, while those formed on Si-doped n-type GaAs (111)B substrates show clear rectifying characteristics. The hybrid nanowires show p-type conductivity possibly owing to the formation of p-type GaAs layers near the nanowire surfaces caused by the thermal diffusion of Mn atoms into GaAs nanowires during the endotaxial nanoclustering of MnAs.
Zinc Oxide Nanowire Forest for Pool Boiling Heat Transfer
Authors: Lee Dongjin , Kim Taehyun , Park Sungsik , Lee Seung Seob , Ko Seung Hwan
Published: November 2012

Zinc oxide (ZnO) nanowire forest is applied for the electronics cooling by means of pool boiling heat transfer. The forest was composed of lengthwise grown backbone and branched nanowires, which were highly dense and tree-like hierarchical structures. The platinum heater and resistance temperature detector were fabricated by microfabrication on one side of silicon chips and nanowire forest was synthesized on the other side. The superheat and heat flux were evaluated at steady state while the voltage in the heater was increased gradually. The heat flux gradually increased linearly with superheat at the initial stage of heating due to convective heat transfer and abruptly increased once the coolant started to boil. It seemed that the nanowire forest played a role of increased bubble nucleation sites with superhydrophilic nature leading to enhancement of boiling heat transfer. This sheds light on application of nanostructured surface as an effective electronics cooling by boiling heat transfer.
Optical Properties of Site-Controlled InGaAs Quantum Dots Embedded in GaAs Nanowires by Selective Metalorganic Chemical Vapor Deposition
Authors: Tatebayashi Jun , Ota Yasutomo , Ishida Satomi , Nishioka Masao , Iwamoto Satoshi , Arakawa Yasuhiko
Published: November 2012

We report the optical properties of site-controlled InGaAs quantum dots (QDs) embedded in GaAs nanowires (NWs) grown by selective metalorganic chemical vapor deposition (MOCVD). InGaAs/GaAs QD-in-NWs with various QD heights and In compositions are realized on patterned GaAs(111)B substrates in the form of InGaAs/GaAs heterostructures, and identified by structural analyses using scanning transmission electron microscopy, photoluminescence (PL) characterization, and numerical analyses of the band structure using a single-band effective mass approximation. Room temperature (RT) light emission is observed at 1.03 µm from InGaAs/GaAs QD-in-NWs which is indicative of the formation of high-quality InGaAs QD-in-NWs. Sharp emission peaks from exciton and biexciton of single In(Ga)As QD-in-NWs are observed by using µ-PL characterization at 10 K.
Enhanced Piezoelectric Response in Nano-Patterned Lead Zirconate Titanate Thin Films
Authors: Waegner Martin , Schröder Mathias , Suchaneck Gunnar , Sturm Heinz , Weimann Christiane , Eng Lukas M. , Gerlach Gerald
Published: November 2012

In this work, Pb(Zr,Ti)O3 thin films were used to fabricate well-ordered nanodot arrays by means of nanosphere lithography. This technique is based on a two-step etch process that enables excellent control of the fabrication of ordered nanodisc arrays of defined height, diameter, and pitch. Piezoresponse force microscopy was used to investigate both non-patterned and patterned films. The topography and both the out-of-plane and the in-plane polarization were deduced in this mode. Grains of nanodots with a low aspect ratio form domain structures comparable to domains in non-patterned two-dimensional films. In contrast, nanodots with a higher aspect ratio form particular structures like bi-sectioned domain assemblies, c-shaped domains or multi-domains surrounding a center domain. The patterning of the ferroelectric material was shown to affect the formation of ferroelectric domains. The initial polycrystalline films with random polarization orientation re-orient upon patterning and then show domain structures dependent on the nanodisc diameter and aspect ratio.
Growth Aspects of Thin-Film Composite Heterostructures of Oxide Multicomponent Perovskites for Electronics
Authors: Endo Kazuhiro , Badica Petre , Arisawa Shunichi , Kezuka Hiroshi , Endo Tamio
Published: November 2012

We review, based on our results, the problems and solutions for the growth of thin films and composite heterostructures emphasizing the general growth aspects and principles vs specifics for each material or heterostructure. The materials used in our examples are Bi2Sr2Ca2Cu3O10, Bi2Sr2CaCu2O8, YBa2Cu3O7, (Sr, Ca)CuO2, (Ba, Ca)CuO2, and Bi4Ti3O12. The growth method was metal organic chemical vapor deposition (MOCVD). The presented thin films or heterostructures havec- and non-c-axis orientations. We discuss the implications of the film–substrate lattice relationships, paying attention to film–substrate lattice mismatch anisotropy and to film–film lattice mismatch, which has a significant influence on the quality of the non-c-axis heterostructures. We also present growth control through the use of vicinal substrates and two-temperature (template) and interrupted growth routes allowing significant quality improvements or optimization. Other key aspects of the growth mechanism, that is, roughness, morphology, and interdiffusion, are addressed. It is concluded that the requirements for the growth of non-c-axis heterostructures are more severe than those for thec-axis ones.
Long Lifetime of Plasma Effect on Bonding of Poly(ethylene terephthalate) Films and Surface Analyses
Authors: Yokura Miyoshi , Hanada Kazuya , Uehara Kenichi , Nakamura Yuichi , Reddy Lakshmi Sanapa , Nishikawa Hiroaki , Nagashima Masatsugu , Endo Tamio
Published: November 2012

Poly(ethylene terephthalate) (PET) films can be bonded directly by oxygen plasma irradiation and heat press at low temperatures of 100–160 °C. The irradiated films were kept in the atmosphere for six years, yet they can be bonded tightly. The irradiated surface is extremely active just after the irradiation, and it is considerably active after five years. Dry- and wet-peel tests suggest hydrogen bonding and chemical bonding. The films are bonded by these two elements at lower press temperatures, while by the pure chemical bonding at higher temperatures. Fourier transform infrared spectroscopy (FTIR) results on the non-irradiated, irradiated and bonded samples indicate that OH and COOH groups are created at the surface, they are responsible for the both bondings. Dehydrated condensation reaction is proposed for the chemical bonding. The hydrogen bonding is broken by water penetration, causing smaller peel strength under the wet-peel test. Cross-linking layer may be the origin for the long lifetime.
Nonvolatile Hybrid Memory Cell Embedded with Ni Nanocrystals in Poly(3-hexylthiophene)
Authors: Lee Jong-Dae , Park Jea-Gun
Published: November 2012

We developed a cross-bar nonvolatile hybrid memory cell embedded with Ni nanocrystals in poly(3-hexylthiophene) (P3HT) with cell area of 4F
2, where F is a feature size. The cell demonstrated nonvolatile memory characteristics, such as a memory margin (I
on/I
off ratio) of ∼5×10, over 103 endurance cycles of program-and-erase, and a retention time of 104 s at 85 °C. In addition, the mechanism of nonvolatile memory operation for the hybrid memory cell was confirmed by the combination of space-charge-limited current and a Fowler–Nordheim tunneling conduction.
Study of Defect Levels in the Band Gap for a Thick InGaN Film
Authors: Lozac'h Mickael , Nakano Yoshitaka , Sang Liwen , Sakoda Kazuaki , Sumiya Masatomo
Published: November 2012

Deep-level transient spectroscopy, thermal admittance spectroscopy (TAS), and deep-level optical spectroscopy techniques have been used to investigate the defect levels in the band gap of a non-doped In0.09Ga0.91N film with a thickness of 300 nm. At temperatures ranging from 10 to 450 K, TAS analysis revealed defect levels at ∼7 meV under the conduction band (E
c) which were homogenously distributed in the InGaN film. The defect levels are considered to be attributed to the residual carrier density, probably originating from indium fluctuations and/or nitrogen vacancies (VN). Compared with the defect density of GaN, the defects of the InGaN film corresponding to the cation vacancies (VIII) and/or the VIII–O complex at 2.07 eV, and the shallow acceptor carbon (CN) defect at 3.05 eV, respectively, were remarkably enhanced. The possible increase of these defects is discussed in terms of VN and its complex with VIII that have been induced in the InGaN film.