1,480 research outputs found
Pulsed versus DC I-V characteristics of resistive manganites
We report on pulsed and DC I-V characteristics of polycrystalline samples of
three charge-ordered manganites, Pr_{2/3}Ca_{1/3}MnO_3, Pr_{1/2}Ca_{1/2}MnO_3,
Bi_{1/2}Sr_{1/2}MnO_3 and of a double-perovskite Sr_2MnReO_6, in a temperature
range where their ohmic resistivity obeys the Efros-Shklovskii variable range
hopping relation. For all samples, the DC I(V) exhibits at high currents
negative differential resistance and hysteresis, which mask a perfectly ohmic
or a moderately nonohmic conductivity obtained by pulsed measurements. This
demonstrates that the widely used DC I-V measurements are usually misleading.Comment: 6 pages, 4 figures. Accepted for publication to AP
Inter-grain tunneling in the half-metallic double-perovskites SrBB'O (BB'-- FeMo, FeRe, CrMo, CrW, CrRe
The zero-field conductivities () of the polycrystaline title
materials, are governed by inter-grain transport. In the majority of cases
their (T) can be described by the "fluctuation induced tunneling"
model. Analysis of the results in terms of this model reveals two remarkable
features: 1. For \emph{all} SrFeMoO samples of various microstructures,
the tunneling constant (barrier width inverse decay-length of the
wave-function) is 2, indicating the existence of an intrinsic insulating
boundary layer with a well defined electronic (and magnetic) structure. 2. The
tunneling constant for \emph{all} cold-pressed samples decreases linearly with
increasing magnetic-moment/formula-unit.Comment: 10 pages, 2 tables, 3 figure
Non-Suicidal Self-Injury in a Large Online Sample of Transgender Adults
Non-suicidal self-injury (NSSI) has been increasing in clinical as well as nonclinical populations in recent years. There are few published reports examining lifetime occurrence of this behavior in transgender and gender nonconforming (TGNC) people. An online survey was conducted with self-identified TGNC adults (n = 773) in the United States over the course of 6 months in 2009. The mean age for the sample was 40.4 years (SD = 13.9). Most participants identified on the trans masculine spectrum (female-to-male or FTM; 52.0%), 33.9% identified on the trans feminine spectrum (male-to-female or MTF), and 8.0% identified as genderqueer. Participants completed the Body Investment Scale, the Depression, Anxiety, and Stress Scales, and the Inventory of Statements about Self-Injury. Results indicated that 41.9% of participants had a lifetime history of NSSI. Scores on the subscales of Protection and Feeling from the Body Investment Scale were found to be statistically predictive of NSSI. These findings shed new light on the lifetime prevalence of NSSI in this online TGNC respondent sample. Practice implications are discussed for mental health professionals who work with TGNC clients in addition to research recommendations
Guided reading staff development training manual
The purpose of this project was to provide a training manual for the topic of guided reading within a balanced literacy program for an elementary school. A broader goal was to use collaboration and reflection when providing training in guided reading. The teachers at my school started asking me questions about guided reading: What is guided reading? How do you get started? How can it help all of my students? What does a guided reading lesson look like? I wanted to prepare a workshop that would give them the knowledge they need
Photocatalytic Formic Acid Conversion on CdS Nanocrystals with Controllable Selectivity for H2 or CO.
Formic acid is considered a promising energy carrier and hydrogen storage material for a carbon-neutral economy. We present an inexpensive system for the selective room-temperature photocatalytic conversion of formic acid into either hydrogen or carbon monoxide. Under visible-light irradiation (λ>420 nm, 1 sun), suspensions of ligand-capped cadmium sulfide nanocrystals in formic acid/sodium formate release up to 116±14 mmol H2 g(cat)(-1) h(-1) with >99% selectivity when combined with a cobalt co-catalyst; the quantum yield at λ=460 nm was 21.2±2.7%. In the absence of capping ligands, suspensions of the same photocatalyst in aqueous sodium formate generate up to 102±13 mmol CO g(cat)(-1) h(-1) with >95% selectivity and 19.7±2.7% quantum yield. H2 and CO production was sustained for more than one week with turnover numbers greater than 6×10(5) and 3×10(6), respectively.This work was supported by the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and the National Foundation for Research, Technology and Development), the OMV Group, the EPSRC (EP/H00338X/2 to ER), the Isaac Newton Trust, the German Research Foundation (MFK), and the Advanced Institute for Materials Research-Cambridge Joint Research Centre (KLO). XPS spectra were obtained at the National EPSRC XPS User's Service (NEXUS) at Newcastle University, an EPSRC Mid-Range Facility.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/anie.20150623
Evaluation of Asperger Syndrome in Youth Presenting to a Gender Dysphoria Clinic
Purpose: There is evolving evidence that children and adolescents with gender dysphoria have higher-than-expected rates of autism spectrum disorder (ASD), yet clinical data on ASD among youth with gender dysphoria remain limited, particularly in North America. This report aims to fill this gap. Methods: We conducted a retrospective review of patient chart data from 39 consecutive youth ages 8 to 20 years (mean age 15.8 years, natal male: n?=?22, natal female: n?=?17) presenting for evaluation at a multidisciplinary gender clinic in a large U.S. pediatric hospital from 2007 to 2011 to evaluate the prevalence of ASD in this patient population. Results: Overall, 23.1% of patients (9/39) presenting with gender dysphoria had possible, likely, or very likely Asperger syndrome as measured by the Asperger Syndrome Diagnostic Scale (ASDS). Conclusion: These findings are consistent with growing evidence supporting increased prevalence of ASD in gender dysphoric children. To guide provision of optimal clinical care and therapeutic intervention, routine assessment of ASD is recommended in youth presenting for gender dysphoria.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140161/1/lgbt.2015.0070.pd
Prevention of Hospital-Acquired Pneumonia: An Integrative Review
Background: Hospital-acquired pneumonia (HAP) not only brings about physical challenges to patients that can lead to death, it also involves financial burdens. Research on how to prevent HAP is a necessity; however, a deficit exists in research concerning prevention of non-ventilator hospital-acquired pneumonia (NV-HAP). The purpose of this study is to synthesize the current research on the nurse’s role in prevention of NV-HAP, identify where additional research is needed, and suggest clinical standards of care to prevent pneumonia in hospitalized patients.
Methods: Data for this integrative review was collected from the following databases: PubMed, Cumulative Index of Nursing and Allied Health Literature (CINAHL), GoogleScholar, Cochrane Register of Controlled Trials, MEDLINE, and OneSearch. An interview with a local hospital registered nurse was conducted.
Results: Four different categories of interventions were researched and the results were synthesized. Oral care, the early mobility bundle and isolations rooms were found to significantly decrease the occurrence of NV-HAP. Incentive spirometry, on the other hand, was not found to effectively decrease NV-HAP.
Discussion: While oral care, early mobility and isolation rooms were all found to significantly reduce the occurrence of NV-HAP, these interventions are most effective when the health care workers carrying them out are educated on properly performing each intervention.
Conclusion: Enhanced oral care and enhanced mobility should be primary interventions for the prevention of NV-HAP, while incentive spirometry should be considered a secondary intervention. More research is needed to be conclusive on the effectiveness of incentive spirometry and isolation rooms
Transition state theory demonstrated at the micron scale with out-of-equilibrium transport in a confined environment
International audienceTransition state theory (TST) provides a simple interpretation of many thermally activated processes. It applies successfully on timescales and length scales that differ several orders of magnitude: to chemical reactions, breaking of chemical bonds, unfolding of proteins and RNA structures and polymers crossing entropic barriers. Here we apply TST to out-of-equilibrium transport through confined environments: the thermally activated translocation of single DNA molecules over an entropic barrier helped by an external force field. Reaction pathways are effectively one dimensional and so long that they are observable in a microscope. Reaction rates are so slow that transitions are recorded on video. We find sharp transition states that are independent of the applied force, similar to chemical bond rupture, as well as transition states that change location on the reaction pathway with the strength of the applied force. The states of equilibrium and transition are separated by micrometres as compared with angstroms/nanometres for chemical bonds
Recommended from our members
Dye-sensitised semiconductors modified with molecular catalysts for light-driven H2 production.
The development of synthetic systems for the conversion of solar energy into chemical fuels is a research goal that continues to attract growing interest owing to its potential to provide renewable and storable energy in the form of a 'solar fuel'. Dye-sensitised photocatalysis (DSP) with molecular catalysts is a relatively new approach to convert sunlight into a fuel such as H2 and is based on the self-assembly of a molecular dye and electrocatalyst on a semiconductor nanoparticle. DSP systems combine advantages of both homogenous and heterogeneous photocatalysis, with the molecular components providing an excellent platform for tuning activity and understanding performance at defined catalytic sites, whereas the semiconductor bridge ensures favourable multi-electron transfer kinetics between the dye and the fuel-forming electrocatalyst. In this tutorial review, strategies and challenges for the assembly of functional molecular DSP systems and experimental techniques for their evaluation are explained. Current understanding of the factors governing electron transfer across inorganic-molecular interfaces is described and future directions and challenges for this field are outlined.This work was supported by the EPSRC (EP/H00338X/2 to E.R.; DTG scholarship to E.P.), the Christian Doppler Research Association (Austrian Federal Ministry of Science, Research and Economy and National Foundation for Research, Technology and Development; E.R. and J.W.), the OMV Group (E.R. and J.W.), the Advanced Institute for Materials ResearchCambridge Joint Research Centre (K.O.), European Commission Marie Curie CIG (303650 to A.R.) and the ERC (291482 to J.D.).This is the final version of the article. It was first available from RSC via http://dx.doi.org/10.1039/C5CS00733
- …