65 research outputs found
Quasiparticle transport in the vortex state of YBa_2Cu_3O_6.9
The effect of vortices on quasiparticle transport in cuprate superconductors
was investigated by measuring the low temperature thermal conductivity of
YBa_2Cu_3O_6.9 in magnetic fields up to 8 T. The residual linear term (as T \to
0) is found to increase with field, directly reflecting the occupation of
extended quasiparticle states. A study for different Zn impurity concentrations
reveals a good agreement with recent calculations for a d-wave superconductor,
thereby shedding light on the nature of scattering by both impurities and
vortices. It also provides a quantitative measure of the gap near the nodes.Comment: 4 pages, 2 included eps figures, significant new analysis wrt other
experiments, to appear in Phys Rev Lett 29 March 199
Low-Energy Quasiparticles in Cuprate Superconductors: A Quantitative Analysis
A residual linear term is observed in the thermal conductivity of
optimally-doped Bi-2212 at very low temperatures whose magnitude is in
excellent agreement with the value expected from Fermi-liquid theory and the
d-wave energy spectrum measured by photoemission spectroscopy, with no
adjustable parameters. This solid basis allows us to make a quantitative
analysis of thermodynamic properties at low temperature and establish that
thermally-excited quasiparticles are a significant, perhaps even the dominant
mechanism in suppressing the superfluid density in cuprate superconductors
Bi-2212 and YBCO.Comment: Revised version with additional page, figure, table and reference; to
appear in Physical Review B (1 August 2000
Near-Infrared Light Device Can Improve Intravenous Cannulation in Critically Ill Children
critically ill children; intravenous cannulation; near-infrared light device Background: Vascular access in critically ill children can be a real challenge for medical staff. In order to evaluate the effectiveness of a near-infrared light vein-viewing device for critically ill children, 60 pediatric inpatients were enrolled in a randomized prospective observation trial for intravenous cannulation. Methods: The patients' demographic data, mean time required to find the first available vessel, first-attempt success rate, mean number of attempts per patient, and the total time taken on the attempts per patient were compared. Results: Less time was required to find the first available vessel in the near-infrared light device group compared with the control group (126.37 vs. 383.61 seconds; p Z 0.027). In addition, the near-infrared light device group had a fewer number of attempts compared with the control group (median 1 vs. 2; p Z 0.004), and also a shorter total time of attempts per patient compared with the control group (186.16 vs. 497.23 seconds; p Z 0.014). Conclusion: The use of a near-infrared light vein-viewing device for vascular access in critically ill children can decrease the total medical time and cost
Transcriptome Changes in Relation to Manic Episode
Bipolar disorder (BD) is highly heritable and well known for its recurrent manic and depressive episodes. The present study focused on manic episode in BD patients and aimed to investigate state-specific transcriptome alterations between acute episode and remission, including messenger RNAs (mRNAs), long noncoding RNAs (lncRNAs), and micro-RNAs (miRNAs), using microarray and RNA sequencing (RNA-Seq) platforms. BD patients were enrolled with clinical information, and peripheral blood samples collected at both acute and remission status spanning for at least 2 months were confirmed by follow-ups. Symptom severity was assessed by Young Mania Rating Scale. We enrolled six BD patients as the discovery samples and used the Affymetrix Human Transcriptome Array 2.0 to capture transcriptome data at the two time points. For replication, expression data from Gene Expression Omnibus that consisted of 11 BD patients were downloaded, and we performed a mega-analysis for microarray data of 17 patients. Moreover, we conducted RNA sequencing (RNA-Seq) in additional samples of 7 BD patients. To identify intraindividual differentially expressed genes (DEGs), we analyzed data using a linear model controlling for symptom severity. We found that noncoding genes were of majority among the top DEGs in microarray data. The expression fold change of coding genes among DEGs showed moderate to high correlations (∼0.5) across platforms. A number of lncRNAs and two miRNAs (MIR181B1 and MIR103A1) exhibited high levels of gene expression in the manic state. For coding genes, we reported that the taste function-related genes, including TAS2R5 and TAS2R3, may be mania state-specific markers. Additionally, four genes showed a nominal p-value of less than 0.05 in all our microarray data, mega-analysis, and RNA-Seq analysis. They were upregulated in the manic state and consisted of MS4A14, PYHIN1, UTRN, and DMXL2, and their gene expression patterns were further validated by quantitative real-time polymerase chain reaction (PCR) (qRT-PCR). We also performed weight gene coexpression network analysis to identify gene modules for manic episode. Genes in the mania-related modules were different from the susceptible loci of BD obtained from genome-wide association studies, and biological pathways in relation to these modules were mainly related to immune function, especially cytokine–cytokine receptor interaction. Results of the present study elucidated potential molecular targets and genomic networks that are involved in manic episode. Future studies are needed to further validate these biomarkers for their roles in the etiology of bipolar illness
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
Long-Term Effectiveness of Physical Exercise-Based Swallowing Interventions for Older Adults with Dementia in a Day-Care Center
Swallowing safety is one of the top health concerns of dementia. Coughing and choking (coughing/choking) are signs of impaired swallowing safety. This study aimed to investigate the effectiveness of regular physical exercise-based swallowing intervention for reducing coughing-choking at the dementia day-care center. This was a retrospective analysis with data from medical records, including age, the clinical dementia rating (CDR), and the frequencies of coughing/choking in ten days (10-day coughing/choking). Those who complied with the exercise programs were assigned to the exercise-based group (n = 22), and those who could not comply were assigned to the non-exercised-based group (n = 7). The non-exercised-based group showed more advanced age and higher CDR than the exercise-based group (p p < 0.05). Our findings suggested that regular physical exercise-based swallowing intervention effectively alleviated coughing/choking problems of older adults with dementia and its effectiveness was long-lasting. For those who could not comply with exercise programs, noticeably with more advanced age and dementia, the effective swallowing intervention period was short-term
The Effect of Cycling Through a Projection-Based Virtual Environment System on Generalized Anxiety Disorder
Virtual reality (VR) has the potential to help clinical medicine manage generalized anxiety disorder (GAD). However, patients with GAD who use traditional head-mounted VR to cycle may cause them to feel motion sickness and fatigue. To solve this problem, a projection-based virtual environment (VE) system was built to provide GAD patients with a sense of immersion while they are cycling. This projection-based VE system allows patients with GAD to interact with the virtual environment and produce experiences similar to cycling in the outdoors. Sixty GAD patients met several screening criteria and were selected as participants. All participants were randomly assigned to one of the two 20-min conditions: (1) Observing watercolor paintings projected by the projector while engaged in cycling with a stationary bicycle; or (2) observing the scenes (i.e., forest or park) projected by the VE system and engaging in cycling with a stationary bicycle. Finally, this study confirmed that patients with GAD in the projection-based VE group exhibited higher alpha values and lower galvanic skin responses (GSR) after cycling than those cycling in the control group. These results showed that cycling in the projection-based VE group allowed the patient with GAD to achieve higher exercise intensity and lower perceived emotional stress
The Investigation of High Quality PEDOT:PSS Film by Multilayer-Processing and Acid Treatment
In this study, we have investigated the performance of multilayer films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) treated with one of the perfluorinated carboxylic acids, named trifluoroacetic acid (TFA). According to the increased density of the PEDOT chain under unit area conditions, the sheet resistance (Rsq) has improved from 300 to 65 Ω/sq through additional processing of PEDOT:PSS from single layer to multilayer. After the further treatment with TFA, however, the Rsq of the multilayer PEDOT:PSS was enhanced to 45 Ω/sq, leading to the decline of film thickness from 400 to 270 nm. Both conductivity and work function based on X-ray photoelectron spectroscopy results have built a breakthrough by double-processing because of the higher density of conductive PEDOT chains and the increase of 0.4 eV alternatives to typical indium tin oxide substrate, respectively. This improvement is contributed to the development of more effective transparent electrodes
- …