387 research outputs found
Infrared superbroadband emission of Bi ion doped germanium-aluminum-sodium glass
Abstract The 96GeO-(3-v)Al 2 O 3 -vNa 2 O-1NaBiO 3 (v = 0, 0.5, 1.5 molar percent designated as A1, A2 and A3) and 96GeO-(3.5-w)Al 2 O 3 -wNa 2 O-0.5Bi 2 O 3 (w = 0.5, 1, 2 molar percent designated as B1, B2 and B3) glasses were prepared by conventional melting method with the measurement of their DTA curve, fluorescence decay curve, transmission, absorption and emission spectra. The near infrared superbroadband emission characteristics of the A1, A2, B1 and B2 glasses peak at $1220 nm were observed when pumped by an 800 nm laser diode. The stimulated emission cross section (r p ) was obtained from the emission spectra. The result indicated that the introduction of Bi 5+ in NaBiO 3 into raw materials could increase the emission intensity of the obtained glasses by 5.6 times than that of Bi 3+ in Bi 2 O 3 , and the FWHM (Dk) and emission lifetime (s) at 1220 nm increased from 195 nm to 275 nm, and 280 ls to 434 ls. Meanwhile, it was found that the absorption edges were blue-shifted from 486 to 447 nm by comparing those of A1 and B1. The absorption edges were considered to be ascribed to the charge transfer from Bi 3+ 6s 2 to Bi 5+ 6s 0 . Therefore we could conclude that the content of Bi 5+ ions in A1 was more than that in B1 glasses. It could be deduced from the emission and absorption spectra that the stronger emission intensity and wider FWHM were due to the higher concentration of Bi 5+ ion in glass. In particular, the increase of Na 2 O content was in proportion to the thermal stability and the value of r p · s and r p · Dk of glasses
Stress, Coping and Suicide Ideation in Chinese College Students
The study was to examine 1) whether stress and coping styles could significantly predict the probability of suicide ideation; 2) and whether coping styles were mediators or moderators on the association between life stress and suicide ideation. The survey was conducted in a sample of 671 Chinese college students. Approximately twenty percent students reported having suicide ideation. Life stress, active coping styles, and passive coping styles all had independent effect on the probability of suicide ideation. Passive coping styles, especially fantasizing, mediated the relation between life stress and suicide ideation. Moderation hypotheses were not supported. Implications of the findings and future directions were discussed
Stress, Coping and Suicide Ideation in Chinese College Students
The study was to examine 1) whether stress and coping styles could significantly predict the probability of suicide ideation; 2) and whether coping styles were mediators or moderators on the association between life stress and suicide ideation. The survey was conducted in a sample of 671 Chinese college students. Approximately twenty percent students reported having suicide ideation. Life stress, active coping styles, and passive coping styles all had independent effect on the probability of suicide ideation. Passive coping styles, especially fantasizing, mediated the relation between life stress and suicide ideation. Moderation hypotheses were not supported. Implications of the findings and future directions were discussed
The traditional Chinese medicine (TCM), Sheng-xue-xiaoban, inhibits the angiogenesis in ovarian cancer in vitro
Purpose: The traditional Chinese medicine (TCM), Sheng-xue-xiao-van (SXXB) is reported to be effective in treatment of thrombocytopenic purpura and chemotherapy-induced thrombocytopenia in clinical practices. The purpose of this study was to explore the functions of the SXXB Capsule in ovarian cancer in vitro.Methods: The toxicity of the medicine was measured using CCK8 method in ovarian cancer cell lines A2780 and OC-3-VGH and also the human ovarian epithelial cell line IOSE80. The cells were treated using the DMSO-diluted SXXB solution with the concentration levels at0, 3.125 and 6.25 ÎĽg/ml. Western blot was applied to measure the VEGFA proteins in each group. Later, the cells treated with 0 and 25ÎĽg/ml SXXB solution for 48h were collected for supernatant. Then HUVECs were co-cultured with the supernatant. Migration and tube formation assays were performed thereafter.Results: SXXB solution showed higher toxicity in ovarian cancer cells than in IOSE80. The protein levels of VEGFA were reduced as the SXXB concentrations increased in ovarian cancer cells but not in IOSE80. Migration and formed tubes were inhibited in HUVECs co-cultured with the supernatant collected from SXXB-treated ovarian cancer cells.Conclusion: The SXXB Capsule might inhibit the angiogenesis in ovarian cancer in vitro
Temporal and bidirectional association between blood pressure variability and arterial stiffness: Cross-lagged cohort study
BACKGROUND: The causal relationship between blood pressure variability (BPV) and arterial stiffness remains debated. OBJECTIVE: This study aimed to explore the temporal and bidirectional associations between long-term BPV and arterial stiffness using a cohort design with multiple surveys. METHODS: Participants from the Beijing Health Management Cohort who underwent health examinations from visit 1 (2010-2011) to visit 5 (2018-2019) were enrolled in this study. Long-term BPV was defined as intraindividual variation using the coefficient of variation (CV) and SD. Arterial stiffness was measured by brachial-ankle pulse wave velocity (baPWV). The bidirectional relationship between BPV and arterial stiffness was explored using cross-lagged analysis and linear regression models, with records before and after visit 3 categorized as phase 1 and phase 2, respectively. RESULTS: Of the 1506 participants, who were a mean of 56.11 (SD 8.57) years old, 1148 (76.2%) were male. The cross-lagged analysis indicated that the standardized coefficients of BPV at phase 1 directing to the baPWV level at phase 2 were statistically significant but not vice-versa. The adjusted regression coefficients of the CV were 4.708 (95% CI 0.946-8.470) for systolic blood pressure, 3.119 (95% 0.166-6.073) for diastolic pressure, and 2.205 (95% CI 0.300-4.110) for pulse pressure. The coefficients of the SD were 4.208 (95% CI 0.177-8.239) for diastolic pressure and 4.247 (95% CI 0.448-8.046) for pulse pressure. The associations were predominant in the subgroup with hypertension, but we did not observe any significant association of baPWV level with subsequent BPV indices. CONCLUSIONS: The findings supported a temporal relationship between long-term BPV and arterial stiffness level, especially among people with hypertension
Progress in the synthesis and reactivity studies of metallabenzenes
Metallabenzenes are metallacyclohexatriene complexes that are derived by replacement of one of the CH groups in benzene with a transition-metal fragment. Their synthesis and aromatic properties have recently attracted considerable attention. This paper summarizes the progress in the synthesis, aromatic property, and reactivity studies of metallabenzenes. We will describe the synthesis and reactivity of typical metallabenzenes with various metals (e.g. osmium, iridium, and ruthenium, etc.), the synthesis and structure of a recent reported example of metallanaphthalene and several rare examples of novel and stable metallabenzynes. Finally, the possible future developments in this field have also been suggested
Association of impaired sensitivity to thyroid hormones with hyperuricemia through obesity in the euthyroid population
Background: Impaired sensitivity to thyroid hormones is a newly proposed clinical entity associated with hyperuricemia in the subclinical hypothyroid population. However, it is unknown whether the association exists in the euthyroid population. This study aimed to explore the association of impaired sensitivity to thyroid hormones (assessed by the thyroid feedback quantile-based index [TFQI], parametric thyroid feedback quantile-based index [PTFQI], thyrotrophic thyroxine resistance index [TT4RI] and thyroid-stimulating hormone index [TSHI]) with hyperuricemia and quantify the mediating effect of body mass index BMI in the euthyroid population. Methods: This cross-sectional study enrolled Chinese adults aged ≥ 20 years who participated in the Beijing Health Management Cohort (2008–2019). Adjusted logistic regression models were used to explore the association between indices of sensitivity to thyroid hormones and hyperuricemia. Odds ratios [OR] and absolute risk differences [ARD] were calculated. Mediation analyses were performed to estimate direct and indirect effects through BMI. Results: Of 30,857 participants, 19,031 (61.7%) were male; the mean (SD) age was 47.3 (13.3) years; and 6,515 (21.1%) had hyperuricemia. After adjusting for confounders, individuals in the highest group of thyroid hormone sensitivity indices were associated with an increased prevalence of hyperuricemia compared with the lowest group (TFQI: OR = 1.18, 95% CI 1.04–1.35; PTFQI: OR = 1.20, 95% CI 1.05–1.36; TT4RI: OR = 1.17, 95% CI 1.08–1.27; TSHI: OR = 1.12, 95% CI 1.04–1.21). BMI significantly mediated 32.35%, 32.29%, 39.63%, and 37.68% of the associations of TFQI, PTFQI, TT4RI and TSHI with hyperuricemia, respectively. Conclusions: Our research revealed that BMI mediated the association between impaired sensitivity to thyroid hormones and hyperuricemia in the euthyroid population. These findings could provide useful evidence for understanding the interaction between impaired sensitivity to thyroid hormone and hyperuricemia in euthyroid individuals and suggest the clinical implications of weight control in terms of impaired thyroid hormones sensitivity
Realization of robust boundary modes and non-contractible loop states in photonic Kagome lattices
Corbino-geometry has well-known applications in physics, as in the design of
graphene heterostructures for detecting fractional quantum Hall states or
superconducting waveguides for illustrating circuit quantum electrodynamics.
Here, we propose and demonstrate a photonic Kagome lattice in the
Corbino-geometry that leads to direct observation of non-contractible loop
states protected by real-space topology. Such states represent the "missing"
flat-band eigenmodes, manifested as one-dimensional loops winding around a
torus, or lines infinitely extending to the entire flat-band lattice. In finite
(truncated) Kagome lattices, however, line states cannot preserve as they are
no longer the eigenmodes, in sharp contrast to the case of Lieb lattices. Using
a continuous-wave laser writing technique, we experimentally establish finite
Kagome lattices with desired cutting edges, as well as in the Corbino-geometry
to eliminate edge effects. We thereby observe, for the first time to our
knowledge, the robust boundary modes exhibiting self-healing properties, and
the localized modes along toroidal direction as a direct manifestation of the
non-contractible loop states
Mechanism of biomass activation and ammonia modification for nitrogen-doped porous carbon materials
- …