3,964 research outputs found
Potassium-doped BaFe2As2 superconducting thin films with a transition temperature of 40 K
We report the growth of potassium-doped BaFe2As2 thin films, where the major
charge carriers are holes, on Al2O3 (0001) and LaAlO3 (001) substrates by using
an ex-situ pulsed laser deposition technique. The measured Tc's are 40 and 39 K
for the films grown on Al2O3 and LaAlO3, respectively and diamagnetism
indicates that the films have good bulk superconducting properties below 36 and
30 K, respectively. The X-ray diffraction patterns for both films indicated a
preferred c-axis orientation, regardless of the substrate structures of LaAlO3
and Al2O3. The upper critical field at zero temperature was estimated to be
about 155 T.Comment: 6 pages including 3 figure
Direct observation of CD4 T cell morphologies and their cross-sectional traction force derivation on quartz nanopillar substrates using focused ion beam technique
Direct observations of the primary mouse CD4 T cell morphologies, e.g., cell adhesion and cell spreading by culturing CD4 T cells in a short period of incubation (e.g., 20 min) on streptavidin-functionalized quartz nanopillar arrays (QNPA) using a high-content scanning electron microscopy method were reported. Furthermore, we first demonstrated cross-sectional cell traction force distribution of surface-bound CD4 T cells on QNPA substrates by culturing the cells on top of the QNPA and further analysis in deflection of underlying QNPA via focused ion beam-assisted technique
Nitrile-assistant eutectic electrolytes for cryogenic operation of lithium ion batteries at fast charges and discharges
The charge/discharge characteristics of lithium ion batteries at low temperature (LT = -20 ??C) are enhanced by using ethylene carbonate (EC)-based electrolytes with the help of assistant solvents of nitriles. Conventional liquid electrolytes (e.g. a mixture of EC and dimethyl carbonate (DMC), abbreviated as LED) cannot support a satisfactory capacity at low temperature as well as at high rates even if electric vehicles require low-temperature operation. Introducing propionitrile or butyronitrile (Pn or Bn) into LED (resulting in LEDPn or LEDBn) as a co-solvent increases significantly the high-rate capacities at -20??C. For example, LEDPn delivers 62% of the available capacity at 1 C and 46% at 3 C with a 2.7 V cut-off while the control LED provides just 6% and 4% at the same rates. Successful operation at -20??C with nitrile-assistant electrolytes results from high ionic conductivity, low viscosity and freezing point depression caused by the eutectic behavior of the carbonates (EC/DMC) and Pn. Based on the phase diagram of Pn with EC/DMC, we expect a meaningful battery operation up to -110??C, probably lower, at the eutectic composition.close0
Involvement of Heme Oxygenase-1 Induction in the Cytoprotective and Immunomodulatory Activities of Viola patrinii in Murine Hippocampal and Microglia Cells
A number of diseases that lead to injury of the central nervous system are caused by oxidative stress and inflammation in the brain. In this study, NNMBS275, consisting of the ethanol extract of Viola patrinii, showed potent antioxidative and anti-inflammatory activity in murine hippocampal HT22 cells and BV2 microglia. NNMBS275 increased cellular resistance to oxidative injury caused by glutamate-induced neurotoxicity and reactive oxygen species generation in HT22 cells. In addition, the anti-inflammatory effects of NNMBS275 were demonstrated by the suppression of proinflammatory mediators, including proinflammatory enzymes (inducible nitric oxide synthase and cyclooxygenase-2) and cytokines (tumor necrosis factor-α and interleukin-1β). Furthermore, we found that the neuroprotective and anti-inflammatory effects of NNMBS275 were linked to the upregulation of nuclear transcription factor-E2-related factor 2-dependent expression of heme oxygenase-1 in HT22 and BV2 cells. These results suggest that NNMBS275 possesses therapeutic potential against neurodegenerative diseases that are induced by oxidative stress and neuroinflammation
In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser
The remarkably high superconducting transition temperature and upper critical
field of iron(Fe)-based layered superconductors, despite ferromagnetic material
base, open the prospect for superconducting electronics. However, success in
superconducting electronics has been limited because of difficulties in
fabricating high-quality thin films. We report the growth of high-quality
c-axis-oriented cobalt(Co)-doped SrFe2As2 thin films with bulk
superconductivity by using an in-situ pulsed laser deposition technique with a
248-nm-wavelength KrF excimer laser and an arsenic(As)-rich phase target. The
temperature and field dependences of the magnetization showing strong
diamagnetism and transport critical current density with superior Jc-H
performance are reported. These results provide necessary information for
practical applications of Fe-based superconductors.Comment: 8 pages, 3figures. to be published at Appl. Phys. Let
Immunoglobulin G Subclass Deficiency is the Major Phenotype of Primary Immunodeficiency in a Korean Adult Cohort
Primary immunodeficiency disease (PID) is a rare disorder in adults. Most often, serious forms are detected during infancy or childhood. However, mild forms of PID may not be diagnosed until later in life, and some types of humoral immunodeficiency may occur in adulthood. The purpose of this study was to identify clinical features of PID in Korean adults. A retrospective study was performed on 55 adult patients who were diagnosed as PID between January 1998 and January 2009 at a single tertiary medical center in Korea. IgG subclass deficiency was the most common phenotype (67%, 37/55), followed by total IgG deficiency (20%, 11/55), IgM deficiency (7%, 4/55), common variable immunodeficiency (2%, 1/55), and X-linked agammaglobulinemia (2%, 1/55). IgG3 and IgG4 were the most affected subclasses. Upper and lower respiratory tract infections (76%) were the most frequently observed symptoms, followed by multiple site infection (11%), urinary tract infection, and colitis. Bronchial asthma, rhinitis, and several autoimmune diseases were common associated diseases. IgG and IgG subclass deficiency should be considered in adult patients presenting with recurrent upper and lower respiratory infections, particularly in those with respiratory allergies or autoimmune diseases
Strengthening deep-learning models for intracranial hemorrhage detection: strongly annotated computed tomography images and model ensembles
Background and purposeMultiple attempts at intracranial hemorrhage (ICH) detection using deep-learning techniques have been plagued by clinical failures. We aimed to compare the performance of a deep-learning algorithm for ICH detection trained on strongly and weakly annotated datasets, and to assess whether a weighted ensemble model that integrates separate models trained using datasets with different ICH improves performance.MethodsWe used brain CT scans from the Radiological Society of North America (27,861 CT scans, 3,528 ICHs) and AI-Hub (53,045 CT scans, 7,013 ICHs) for training. DenseNet121, InceptionResNetV2, MobileNetV2, and VGG19 were trained on strongly and weakly annotated datasets and compared using independent external test datasets. We then developed a weighted ensemble model combining separate models trained on all ICH, subdural hemorrhage (SDH), subarachnoid hemorrhage (SAH), and small-lesion ICH cases. The final weighted ensemble model was compared to four well-known deep-learning models. After external testing, six neurologists reviewed 91 ICH cases difficult for AI and humans.ResultsInceptionResNetV2, MobileNetV2, and VGG19 models outperformed when trained on strongly annotated datasets. A weighted ensemble model combining models trained on SDH, SAH, and small-lesion ICH had a higher AUC, compared with a model trained on all ICH cases only. This model outperformed four deep-learning models (AUC [95% C.I.]: Ensemble model, 0.953[0.938–0.965]; InceptionResNetV2, 0.852[0.828–0.873]; DenseNet121, 0.875[0.852–0.895]; VGG19, 0.796[0.770–0.821]; MobileNetV2, 0.650[0.620–0.680]; p < 0.0001). In addition, the case review showed that a better understanding and management of difficult cases may facilitate clinical use of ICH detection algorithms.ConclusionWe propose a weighted ensemble model for ICH detection, trained on large-scale, strongly annotated CT scans, as no model can capture all aspects of complex tasks
Universal compressive characterization of quantum dynamics
Recent quantum technologies utilize complex multidimensional processes that
govern the dynamics of quantum systems. We develop an adaptive
diagonal-element-probing compression technique that feasibly characterizes any
unknown quantum processes using much fewer measurements compared to
conventional methods. This technique utilizes compressive projective
measurements that are generalizable to arbitrary number of subsystems. Both
numerical analysis and experimental results with unitary gates demonstrate low
measurement costs, of order for -dimensional systems, and
robustness against statistical noise. Our work potentially paves the way for a
reliable and highly compressive characterization of general quantum devices.Comment: 10 pages, 6 figure
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