350 research outputs found

    Plasmonic Enhancement of Emission from Si-nanocrystals

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    Plasmonic gratings of different periodicities are fabricated on top of Silicon nanocrystals embedded in Silicon Dioxide. Purcell enhancements of up to 2 were observed, which matches the value from simulations. Plasmonic enhancements are observed for the first three orders of the plasmonic modes, with the peak enhancement wavelength varying with the periodicity. Biharmonic gratings are also fabricated to extract the enhanced emission from the first order plasmonic mode, resulting in enhancements with quality factors of up to 16.Comment: 4 pages, 5 figures added explanation of low purcell enhancement updated figure

    Photoluminescence from silicon dioxide photonic crystal cavities with embedded silicon nanocrystals

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    One dimensional nanobeam photonic crystal cavities are fabricated in silicon dioxide with silicon nanocrystals. Quality factors of over 9 x 10^3 are found in experiment, matching theoretical predictions, with mode volumes of 1.5(lambda/n)^3 . Photoluminescence from the cavity modes is observed in the visible wavelength range 600-820 nm. Studies of the lossy characteristics of the cavities are conducted at varying temperatures and pump powers. Free carrier absorption effects are found to be significant at pump powers as low as a few hundred nanowatts.Comment: 13 pages 9 figure

    Electroluminescence from Strained Ge membranes and Implications for an Efficient Si-Compatible Laser

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    We demonstrate room-temperature electroluminescence (EL) from light-emitting diodes (LED) on highly strained germanium (Ge) membranes. An external stressor technique was employed to introduce a 0.76% bi-axial tensile strain in the active region of a vertical PN junction. Electrical measurements show an on-off ratio increase of one order of magnitude in membrane LEDs compared to bulk. The EL spectrum from the 0.76% strained Ge LED shows a 100nm redshift of the center wavelength because of the strain-induced direct band gap reduction. Finally, using tight-binding and FDTD simulations, we discuss the implications for highly efficient Ge lasers.Comment: 4 Pages, 5 figure

    Burkitt's Lymphoma Mimicking a Primary Gynecologic Tumor

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    SummaryObjectiveBurkitt's lymphoma (BL) occurs mostly in children; bilateral ovarian involvement mimicking a gynecologic malignancy in adults is extremely rare. Here, we report a patient with BL mimicking a gynecologic tumorCase ReportA 50-year-old Taiwanese woman presented with the complaint of persistent lower abdominal distension with dull pain, easy satiety, and progressively increasing abdominal girth for 2 weeks. Amenorrhea was also noted for about 2 months, and her review of systems was negative for the common “B” symptoms associated with lymphoma. At our hospital, imaging studies revealed a huge pelvic mass (10.8 ×8.7 cm), suggesting a large subserous myoma or an ovarian tumor. Under the impression of pelvic mass, she underwent exploratory laparotomy. Primary ovarian sex-cord malignancy with cecum involvement was impressed by the primitive intraoperative frozen section report. Subsequently, an optimal cytoreductive operation with right hemicolectomy was performed. However, final histopathologic report was an extranodal multifocal BL.ConclusionAlthough extranodal BL in ovaries is a rare condition, it should be noted in the differential diagnosis of pelvic gynecologic malignancies

    The Influence of Ingestion Glucose Beverage before Graded Exercise to Exhaustion on Saliva IgA Concentration in Hypoxia and Normoxia Environment

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    In addition to exercise, hypoxia environment might induce higher immune stress. The present study was to investigate the ingestion of glucose before graded exercise to exhaustion in hypoxia environment on immune responses. Eight healthy college students

    Antiviral Ability of Kalanchoe gracilis Leaf Extract against Enterovirus 71 and Coxsackievirus A16

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    Pandemic infection or reemergence of Enterovirus 71 (EV71) and coxsackievirus A16 (CVA16) occurs in tropical and subtropical regions, being associated with hand-foot-and-mouth disease, herpangina, aseptic meningitis, brain stem encephalitis, pulmonary edema, and paralysis. However, effective therapeutic drugs against EV71 and CVA16 are rare. Kalanchoe gracilis (L.) DC is used for the treatment of injuries, pain, and inflammation. This study investigated antiviral effects of K. gracilis leaf extract on EV71 and CVA16 replications. HPLC analysis with a C-18 reverse phase column showed fingerprint profiles of K. gracilis leaf extract had 15 chromatographic peaks. UV/vis absorption spectra revealed peaks 5, 12, and 15 as ferulic acid, quercetin, and kaempferol, respectively. K. gracilis leaf extract showed little cytotoxicity, but exhibited concentration-dependent antiviral activities including cytopathic effect, plaque, and virus yield reductions. K. gracilis leaf extract was shown to be more potent in antiviral activity than ferulic acid, quercetin, and kaempferol, significantly inhibiting in vitro replication of EV71 (IC50 = 35.88 μg/mL) and CVA16 (IC50 = 42.91 μg/mL). Moreover, K. gracilis leaf extract is a safe antienteroviral agent with the inactivation of viral 2A protease and reduction of IL-6 and RANTES expressions

    Effect of Supplementation of Tanshinone IIA and Sodium Tanshinone IIA Sulfonate on the Anticancer Effect of Epirubicin: An In Vitro Study

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    Tanshinone IIA (Tan IIA) and sodium tanshinone IIA sulfonate (STS) were found to have protective effects on cardiomyocyte against adriamycin-induced damage and may be used clinically. It is unclear whether the supplementation of STS or Tan IIA would affect the anticancer activity of anthracycline. To evaluate the effect of Tan IIA or STS on the anticancer of epirubicin, the cell viability, apoptosis, Akt expression, and uptake of epirubicin after supplementation of Tan IIA or STS in the epirubicin-treated BT-20 cells were measured and compared. Tan IIA inhibited BT-20 cell growth and induced apoptosis in a time- and dose-dependent manner. When Tan IIA was used with epirubicin, an increase of BT-20 cells apoptosis was accompanied by the decreasing phosphorylation of Akt. STS had no effect on the cell viability of BT-20 cells. However, when used with epirubicin, STS decreased the epirubicin-induced cytotoxicity and apoptosis in BT-20 cells. The antagonistic effect of STS on epirubicin-induced cytotoxicity in BT-20 cells occurred concomitantly with the reduced epirubicin uptake and the increased phosphorylation of Akt. STS decreased the uptake of epirubicin in BT-20 cells and blocked epirubicin-induced apoptosis through activation of Akt

    Mediating role of resilience in the relationships of physical activity and mindful self-awareness with peace of mind among college students

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    Abstract Peace of mind (PoM) is an index of mental health in Asian culture and emphasizes low arousal, happiness, harmony, and an internal state of peacefulness. While previous studies have found that mindful self-awareness can contribute to PoM, regular physical activity (PA) is also an important factor contributing to one’s PoM due to its function in promoting one's resilience. The study aims to investigate a hypothetical model that assumes PA is associated with resilience while controlling for mindful self-awareness, contributing to PoM. The PoM scale, Connor-Davidson Resilience Scale, Chinese translation of Mindful Attention Awareness Scale, and PA self-report questionnaire were used. A path analysis was applied to test the association between these variables and the mediating role of resilience. A total of 436 students from a university in Taiwan were recruited; the mean age was 20.87, with 46.3% female and 73.6% engaging in over 150 min/week of moderate PA. Gender and age negatively correlated with PA. After controlling for age and gender, there was no direct effect of physical activity on PoM; both mindful self-awareness and PA predict resilience, which in turn predicts PoM, suggesting that both cognitive (i.e., mindful self-awareness) and PA are important to cultivate resilience and thus PoM
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