871 research outputs found
A Rare Presentation of Conjunctival Myxoma with Pain and Redness: Case Report and Literature Review
Background: Conjunctival myxoma is a type of rare, benign tumor of mesenchymal cells, with fewer than 30 reported cases in the English literature. It is mostly an isolated occurrence but can sometimes be associated with systemic diseases such as Carney complex or Zollinger-Ellison syndrome. It is necessary in clinical practice to differentiate it from other similar lesions, such as amelanotic nevus, lymphangioma, myxoid liposarcoma, spindle-cell lipoma, myxoid neurofibroma, and rhabdomyosarcoma. Case Presentation: The usual presentation of conjunctival myxoma is a translucent, well-circumscribed, and painless conjunctival mass, but in this report we discuss an unusual case of conjunctival myxoma in a 47-year-old Taiwanese woman who presented initially with pain and redness. This atypical presentation complicated the diagnosis and the management at first. Surgical excision of the mass was performed. The mass was found to be a conjunctival myxoma. The patient subsequently underwent extensive evaluation but was found not to have any systemic diseases with known association with conjunctival myxoma. Conclusions: In summary, we present a case of conjunctival myxoma in a 47-year-old Taiwanese woman. The initial presentation with pain and redness was atypical for conjunctival myxoma. The lesion was successfully managed with complete excisional biopsy
INVESTIGATING THE INFLUENCE OF AUTHORITARIAN LEADERSHIP AND SUPERVISOR SATISFACTION ON TURNOVER INTENTION: THE MODERATING ROLE OF EMPLOYEE UPBRINGING
Authoritarian leadership is prevalent in the Asian region, and previous research has found a positive correlation between authoritarian leadership and employees' intention to leave their jobs. However, there are employees in the workplace who can adapt to such supervisors. Therefore, we approach this study from the perspective of "fit theory" to explore whether employees with authoritarian family upbringing can match with authoritarian leadership. This study aims to investigate the impact of authoritarian leadership on employees' intention to leave, with supervisor satisfaction as the mediator and employees' authoritarian family upbringing as the moderator. A total of 232 valid questionnaires were collected in this study. The results revealed that the level of authoritarian family upbringing among employees has a moderating effect on the relationship between authoritarian leadership and supervisor satisfaction
A Study of the December 1992 Westerly Wind Burst Event during TOGA COARE
Using the Penn State/NCAR MM5 mesoscale model, a westerly wind burst (WWB) that occurred during the period from 19 to 30 December 1992 over the Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment (TOGA COARE) has been simulated and compared with observation. This event is characterized by the presence of super cloud clusters and the occurrence of a major WWB that extended over the western and central Pacific Ocean. Although several of the observed convective systems were not precisely simulated by MM5, the model did capture many other observed characteristics, such as the explosive development of convection, the cyclonic circulation and the WWB. The WWB resulted from the coalescence of three types of tropical disturbances. The first type was a low-level westerly jet (LWJ) that developed at the equator and may be associated with the eastward propagation of an ISO (Intraseasonal Oscillation). The second type featured an easterly wave-like disturbance that originated in the south central Pacific Ocean and propagated westward. Finally, the third type involved a cross-equatorial flow that deflected Northern Hemispheric easterlies into the Southern Hemisphere and may be caused by inertial instability. These disturbances worked in concert, resulting in intense convection over the TOGA COARE region. Once intense convection developed, a large-scale circulation was produced over the western Pacific warm pool, propagated eastward, and initiated a WWB
Sustained Robust Exciton Emission in Suspended Monolayer WSe_2 within the Low Carrier Density Regime for Quantum Emitter Applications
The development of semiconductor optoelectronic devices is moving toward low
power consumption and miniaturization, especially for high-efficiency quantum
emitters. However, most of these quantum sources work at low carrier density
region, where the Shockley-Read-Hall recombination may dominant and seriously
reduce the emission efficiency. In order to diminish the affection of carrier
trapping and sustain a strong photoluminescence emission under low power
pumping condition, we investigated on the influence of Suspending to
monolayered tungsten diselenide, novel two-dimensional quantum material. Not
only the PL intensity, but also the fundamental photoluminescence quantum yield
has exhibited a huge, order-scale enhancement through suspending, even
surprisingly, we found the PLQY improvement revealed far significantly under
small pumping power and came out an exponential increase tendency toward even
lower carrier density region. With its strong excitonic effect, suspended WSe_2
offers a solution to reduce carrier trapping and participate in non-radiative
processes. Moreover, in the low-power range where SRH recombination dominates,
suspended WSe_2 exhibited remarkably higher percentage of excitonic radiation
compared to contacted WSe_2. Herein, we quantitatively demonstrate the
significance of suspended WSe_2 monolayer at low carrier density region,
highlighting its potential for developing compact, low-power quantum emitters
in the future
Soluble tumor endothelial marker 1 in heart failure with reduced ejection fraction: A pilot study
BackgroundTumor endothelial marker 1 (TEM1/CD248) is a transmembrane protein that expresses in mesenchymal lineage derived cells during embryogenesis and becomes undetectable in normal adults after birth. Re-expression of TEM1 is found in organ fibrosis, wound healing and cardiac remodeling indicating its potential role in heart failure (HF). The purpose of this study is to explore the role of soluble TEM1 (sTEM1) in patients with HF with reduced ejection fraction.MethodsWe examined endomyocardial biopsy specimens from three HF patients and blood samples from 48 patients admitted for acute decompensated HF (age 72 years, men 61.7%). The expression of TEM1 in cardiac tissue and concentrations of sTEM1 in plasma were evaluated. Cultured rat cardiomyocytes (H9c2) and human cardiac fibroblasts (HCF) were stimulated with hypoxia or transforming growth factor beta (TGF-β) to observe the release of sTEM1 into culture media. The conditioned media of hypoxia-stimulated H9c2 cells was harvested and added into cultured cardiac fibroblast to evaluate its biological effect.ResultsImmunofluorescence study of biopsy specimens from three HF patients showed TEM1 expression in cardiomyocytes and cardiac fibroblasts. The plasma level of sTEM1 was significantly higher in patients (0.90 ± 0.23 vs. 0.33 ± 0.10 ng/mL, p = 0.032) with LVEF ≤ 35% compared with those with LVEF 36–49%. The sTEM1 levels had correlations with HF biomarkers of cardiac fibrosis, including growth differentiation factor-15 (GDF-15) and galectin-3. There was a significant increase in sTEM1 levels in the cultured media of H9c2 and HCF after being stressed with hypoxia or TGF-β. The conditioned media derived from hypoxia-stimulated H9c2 cells significantly increased cell proliferation of cardiac fibroblasts. This effect was partially reversed by anti-TEM1 antibody.ConclusionThis pilot study demonstrated that cardiac TEM1 expression was upregulated in HF. The levels of sTEM1 were significantly higher in HF patients with LVEF ≤ 35% and correlated with other biomarkers of cardiac fibrosis. In vitro study proved that functional sTEM1 was released into cultured media after stressing cardiomyocytes and HCF
Boron Isotopic Analysis of Representative Atmospheric Aerosols Derived From Long-Range Transported/Local Emission on an Islet Offshore NE Taiwan
To identify pollutant origins and their potential sources from either long-range transported (LRT) or local emissions, the Boron (B) concentrations and the B isotopic compositions (δ11B) in the water-soluble fraction of aerosols were determined. These aerosols were collected from an islet offshore in northeastern Taiwan, Peng Chia Yu (PCY), a non-residential islet, from January 1998 to March 2000. This islet may be influenced by various pollutants or chemical transport during monsoon periods, but suffers minimal human perturbation locally. The B in the specimens falls to 0.3–1.63 ng m−3 during the SW monsoon seasons when compared to 0.46–2.56 ng m−3 in the NE monsoon. However, the δ11B results show no clear variations in both monsoon seasons (10.7–24.3‰), regardless of differences in air mass origin. A two end-member mixing scenario is proposed to explain our observations using the obtained δ11B and 1/[B] results. The ocean endmember is characterized by high 1/[B] and high δ11B; while other endmember is from continental endmember or anthropogenic contributions that are characterized by of 1/[B] and lowδ11B (δ11B < 10‰). Based on these chemical and isotopic results, we found aerosol emissions in northern Taiwan are characterized as low B with nearly constant δ11B, when compared with long-range transported continental endmembers derived from nearby regions. This study provides preliminary B and δ11B levels in aerosols derived from LRT/local emissions and discusses potential monsoonal effects on aerosols offshore of NE Taiwan
Formulation of novel lipid-coated magnetic nanoparticles as the probe for in vivo imaging
<p>Abstract</p> <p>Background</p> <p>Application of superparamagnetic iron oxide nanoparticles (SPIOs) as the contrast agent has improved the quality of magnetic resonance (MR) imaging. Low efficiency of loading the commercially available iron oxide nanoparticles into cells and the cytotoxicity of previously formulated complexes limit their usage as the image probe. Here, we formulated new cationic lipid nanoparticles containing SPIOs feasible for <it>in vivo </it>imaging.</p> <p>Methods</p> <p>Hydrophobic SPIOs were incorporated into cationic lipid 1,2-dioleoyl-3-(trimethylammonium) propane (DOTAP) and polyethylene-glycol-2000-1,2-distearyl-3-sn-phosphatidylethanolamine (PEG-DSPE) based micelles by self-assembly procedure to form lipid-coated SPIOs (L-SPIOs). Trace amount of Rhodamine-dioleoyl-phosphatidylethanolamine (Rhodamine-DOPE) was added as a fluorescent indicator. Particle size and zeta potential of L-SPIOs were determined by Dynamic Light Scattering (DLS) and Laser Doppler Velocimetry (LDV), respectively. HeLa, PC-3 and Neuro-2a cells were tested for loading efficiency and cytotoxicity of L-SPIOs using fluorescent microscopy, Prussian blue staining and flow cytometry. L-SPIO-loaded CT-26 cells were tested for <it>in vivo </it>MR imaging.</p> <p>Results</p> <p>The novel formulation generates L-SPIOs particle with the average size of 46 nm. We showed efficient cellular uptake of these L-SPIOs with cationic surface charge into HeLa, PC-3 and Neuro-2a cells. The L-SPIO-loaded cells exhibited similar growth potential as compared to unloaded cells, and could be sorted by a magnet stand over ten-day duration. Furthermore, when SPIO-loaded CT-26 tumor cells were injected into Balb/c mice, the growth status of these tumor cells could be monitored using optical and MR images.</p> <p>Conclusion</p> <p>We have developed a novel cationic lipid-based nanoparticle of SPIOs with high loading efficiency, low cytotoxicity and long-term imaging signals. The results suggested these newly formulated non-toxic lipid-coated magnetic nanoparticles as a versatile image probe for cell tracking.</p
Radio Occultation Retrieval of Atmospheric Profiles from the FORMOSAT-3/COSMIC Mission: Early Results
Six identical micro-satellites of the FORMOSAT-3/COSMIC (Formosa Satellite #3 and Constellation Observing System for Meteorology, Ionosphere and Climate: FS-3/C) mission were successfully launched on 14 April 2006. The FS-3/C mission provides the first satellite constellation for monitoring global weather using the Global Positioning System (GPS) radio occultation (RO) technique. The mission¡¦s primary scientificific goal is to obtain near-real time profiles of the bending angle and refractivity in the neutral atmosphere and in the ionosphere. In April, 2007 the FS-3/C mission provide about RO soundings of 2000 atmospheric vertical profiles per day in a nearly uniform distribution around the globe. The lowest altitude penetration for more than 80% of RO soundings reached below 1 kmin altitude. Most soundings have penetration below 800m altitude in the equatorial region and below 200 m altitude in polar regions. The quality and accuracy of the RO sounding profiles are in good agreement with the CHAMP(CHAllenging Minisatellite Payload) RO soundings and direct measurements using dropsondes. The FS-3/C RO sounding observations are used to support operational global weather prediction, climate monitoring and research, space weather forecasting, and ionosphere and gravity research
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