1,612 research outputs found
Atomic ionization by sterile-to-active neutrino conversion and constraints on dark matter sterile neutrinos with germanium detectors
The transition magnetic moment of a sterile-to-active neutrino conversion
gives rise to not only radiative decay of a sterile neutrino, but also its
non-standard interaction (NSI) with matter. For sterile neutrinos of keV-mass
as dark matter candidates, their decay signals are actively searched for in
cosmic X-ray spectra. In this work, we consider the NSI that leads to atomic
ionization, which can be detected by direct dark matter experiments. It is
found that this inelastic scattering process for a nonrelativistic sterile
neutrino has a pronounced enhancement in the differential cross section at
energy transfer about half of its mass, manifesting experimentally as peaks in
the measurable energy spectra. The enhancement effects gradually smear out as
the sterile neutrino becomes relativistic. Using data taken with germanium
detectors that have fine energy resolution in keV and sub-keV regimes,
constraints on sterile neutrino mass and its transition magnetic moment are
derived and compared with those from astrophysical observations
Unraveling the Role of the rssC Gene of Serratia marcescens by Atomic Force Microscopy
100學年度研究獎補助論文[[abstract]]The product and direct role of the rssC gene of Serratia marcescens is unknown. For unraveling the role of the rssC gene, atomic force microscopy has been used to identify the surfaces of intact S. marcescens wild-type CH-1 cells and rssC mutant CH-1ΔC cells. The detailed surface topographies were directly visualized, and quantitative measurements of the physical properties of the membrane structures were provided. CH-1 and CH-1ΔC cells were observed before and after treatment with lysozyme, and their topography-related parameters, e.g., a valley-to-peak distance, mean height, surface roughness, and surface root-mean-square values, were defined and compared. The data obtained suggest that the cellular surface topography of mutant CH-1ΔC becomes rougher and more precipitous than that of wild-type CH-1 cells. Moreover, it was found that, compared with native wild-type CH-1, the cellular surface topography of lysozyme-treated CH-1 was not changed profoundly. The product of the rssC gene is thus predicted to be mainly responsible for fatty-acid biosynthesis of the S. marcescens outer membrane. This study represents the first direct observation of the structural changes in membranes of bacterial mutant cells and offers a new prospect for predicting gene expression in bacterial cells.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]GB
Clinical characteristics and treatment outcomes of patients with tubo-ovarian abscess at a tertiary care hospital in Northern Taiwan
Background/PurposeControversy exists regarding the need for surgical intervention in patients with tubo-ovarian abscess (TOA). This study was aimed at investigating the clinical characteristics and treatment outcomes in patients with TOA at a tertiary care hospital in Taiwan.MethodsThe medical records of 83 patients who presented at the hospital with TOA between January 1, 2006, and December 31, 2007, were retrospectively reviewed. Outcomes of patients who received medical treatment alone or underwent surgical intervention were analyzed using univariate and logistic regression analyses.ResultsAmong the 83 patients with TOA, 13 patients (15.7%) underwent surgical intervention, and 70 patients (84.3%) received medical treatment alone. Significant variables related to surgical treatment in the univariate analysis were length of stay (short vs. long; t = −2.267, p = 0.026), department of admission (emergency room vs. outpatient department; χ2 = 7.459, p = 0.006), number of live births (nulliparous vs. multiparous; χ2 = 18.202, p = 0.001), and C-reactive protein (CRP) level (high vs. low; t = −2.250, p = 0.028). Logistic regression analysis performed to determine influential factors for surgical treatment showed that the operation odds ratio of three to four live births versus no live births was 33.995 (p = 0.043) and that of two live births versus no live births was 13.598 (p = 0.026).ConclusionPatients with TOA who underwent surgery had a longer duration of hospitalization. Among the patients who underwent surgical intervention, those admitted to the emergency room had higher CRP levels and were more likely to be multiparous
Emergency medical services key performance measurement in Asian cities
10.1186/s12245-015-0062-7International Journal of Emergency Medicine8
Knowledge withholding intentions in teams: the roles of normative conformity, affective bonding, rational choice and social cognition
The decision of members in a knowledge-intensive team to withhold their knowledge may threaten the performance of the team. To address the problem of knowledge resource risk in project teams, we maintain that it is important to understand why team members choose to withhold their knowledge, conceptualized as knowledge-withholding intention. In line with the literature on effort withholding, the research on multifoci relations between justice perceptions and social exchanges, and social cognitive theory, we proposed that the social exchange relationships that individuals form in the workplace, their perceptions of justice, and their knowledge withholding self-efficacy would influence their knowledge-withholding intentions. Through a survey of 227 information system development team workers, we found that all social exchange relationship variables had a significant impact on knowledge-withholding intentions. However, the justice perception variables only indirectly influenced knowledge-withholding intentions through the mediation of social exchange relationships. In addition, one of the task variables, task interdependence, influenced knowledge withholding intention through the mediation of knowledge withholding self-efficacy. Our results contribute to the knowledge management literature by providing a better understanding of the antecedents of knowledge withholding. We also offer suggestions for future research utilizing the framework of Kidwell and Bennett (1993) to study effort and knowledge withholding
To Enhance the Fire Resistance Performance of High-Speed Steel Roller Door with Water Film System
The structure of high-speed roller door with water film has improved in this study. The flameproof water film system is equipped with a water circulating device to reduce the water consumption of water film system. The water film is generated at the roller box of the high-speed roller door in this study. The heating test is done with the full-scale heating furnace. Both cases of the water film on unexposed surface and water film on exposed surface passed the fire resistance test based on ISO 834, proving that the high-speed roller door with water film system has 120A fire resistance period. The main findings indicate that the water film on exposed surface shows that as the amount of water film evaporated by high temperature inside the furnace must be greater than the evaporation capacity of water film on unexposed surface, the required water supply is 660 L more than the water film on unexposed surface
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