496 research outputs found
Kinetic Parameters Evaluation for Isoprene Mixed with Aluminum Oxide
AbstractWe analyzed the basic hazard characteristics for isoprene in the manufacturing process by evaluating the runaway reaction, kinetic parameters and safety parameters in this study. Experiments were carried out by calculating the thermal decomposition reactions for isoprene and mixed with aluminum oxide in non-isothermal conditions by differential scanning calorimetry (DSC). Afterwards results indicated that isoprene had a conjugated double bond of unstable structure, and therefore it was prone to produce exothermic reaction during the process of polymerization. Aluminum oxide was applied to mix with isoprene, which could increase the heat release rate. Based on the results, safety information should be provided to government and relevant industries for prevention the accident occur in relevant plants
The Role of the Fabrication of Anatase-TiO2 Chain-Networked Photoanodes
A novel, sandwich-layered Ti/TiO2/Ti/fluorine-doped tin oxide (FTO) architecture is reported. The Ti layers play a critical role in the formation of long pear-necklace chains made of interconnected TiO2 nanoparticles. The chains interpenetrate a network structure on FTO glass substrates under alkaline hydrothermal-processing conditions. A significant enhancement in the photocurrent density of dye-sensitized solar cells employing non-volatile polymer-based electrolytes is obtained
Measurement of Trace I-129 Concentrations in CsI Powder and Organic Liquid Scintillator with Accelerator Mass Spectrometry
Levels of trace radiopurity in active detector materials is a subject of
major concern in low-background experiments. Procedures were devised to measure
trace concentrations of I-129 in the inorganic salt CsI as well as in organic
liquid scintillator with Accelerator Mass Spectrometry (AMS) which leads to
improvement in sensitivities by several orders of magnitude over other methods.
No evidence of their existence in these materials were observed. Limits of < 6
X 10^{-13} g/g and < 2.6 X 10^{-17} g/g on the contaminations of I-129 in CsI
and liquid scintillator, respectively, were derived.These are the first results
in a research program whose goals are to develop techniques to measure trace
radioactivity in detector materials by AMS.Comment: Proceedings of 10th International Conference on Accelerator Mass
Spectrometr
Association between first caesarean delivery and adverse outcomes in subsequent pregnancy: a retrospective cohort study
BACKGROUND:Few studies have explored the association between a previous caesarean section (CS) and adverse perinatal outcomes in a subsequent pregnancy, especially in women who underwent a non-indicated CS in their first delivery. We designed this study to compare the perinatal outcomes of a subsequent pregnancy in women who underwent spontaneous vaginal delivery (SVD) or CS in their first delivery. METHODS:This retrospective cohort study included women who underwent singleton deliveries at the International Peace Maternity and Child Health Hospital from January 2013 to December 2016. Data on the perinatal outcomes of all the women were extracted from the medical records. Multivariate logistic regression was conducted to assessed the association between CS in the first delivery and adverse perinatal outcomes in the subsequent pregnancy. RESULTS:CS delivery in the subsequent pregnancy was more likely for women who underwent CS in their first birth than for women with previous SVD (97.3% versus 13.2%). CS in the first birth was also associated with a significantly increased risk of adverse outcomes in the subsequent pregnancy, especially in women who underwent a non-indicated CS. Adverse perinatal outcomes included pregnancy-induced hypertension [adjusted odds ratio (OR), 95% confidence interval (CI): 2.20, 1.59-3.05], gestational diabetes mellitus (1.82, 1.57-2.11), gestational anaemia (1.27, 1.05-1.55), placenta previa (3.18, 2.15-4.71), placenta accreta (2.75, 1.75-4.31), and polyhydramnios (2.60, 1.57-4.31) in the mother and preterm delivery (1.37, 1.06-1.78), low birth weight (3.78, 2.07-6.90), macrosomia (5.04, 3.95-6.44), and neonatal jaundice (1.72, 1.39-2.14) in the baby. CONCLUSIONS:CS in the first delivery markedly increases the risk of repeated CS and maternal-fetal complications in the subsequent pregnancy, especially in women with a non-indicated CS.Hong-Tao Hu, Jing-Jing Xu, Jing Lin, Cheng Li, Yan-Ting Wu, Jian-Zhong Sheng, Xin-Mei Liu and He-Feng Huan
Independent Eigenstates of Angular Momentum in a Quantum N-body System
The global rotational degrees of freedom in the Schr\"{o}dinger equation for
an -body system are completely separated from the internal ones. After
removing the motion of center of mass, we find a complete set of
independent base functions with the angular momentum . These are
homogeneous polynomials in the components of the coordinate vectors and the
solutions of the Laplace equation, where the Euler angles do not appear
explicitly. Any function with given angular momentum and given parity in the
system can be expanded with respect to the base functions, where the
coefficients are the functions of the internal variables. With the right choice
of the base functions and the internal variables, we explicitly establish the
equations for those functions. Only (3N-6) internal variables are involved both
in the functions and in the equations. The permutation symmetry of the wave
functions for identical particles is discussed.Comment: 24 pages, no figure, one Table, RevTex, Will be published in Phys.
Rev. A 64, 0421xx (Oct. 2001
Role of calcineurin in Porphyromonas gingivalis-induced myocardial cell hypertrophy and apoptosis
Background and objective: Periodontal pathogen Porphyromonas gingivalis (P. gingivalis) increased cardiomyocyte hypertrophy and apoptosis whereas Actinobaeillus actinomycetemcomitans and Prevotella intermedia had no effects. The purpose of this study is to clarify the role of calcineurin signaling pathway in P. gingivalis-induced H9c2 myocardial cell hypertrophy and apoptosis. Methods: DNA fragmentation, nuclear condensation, cellular morphology, calcineurin protein, Bcl2- associated death promoter (Bad) and nuclear factor of activated T cell (NFAT)-3 protein products in cultured H9c2 myocardial cell were measured by agarose gel electrophoresis, DAPI, immunofluorescence, and Western blotting following P. gingivalis and/or pre-administration of CsA (calcineurin inhibitors cyclosporin A). Results: P. gingivalis not only increased calcineurin protein, NFAT-3 protein products and cellular hypertrophy, but also increased DNA fragmentation, nuclear condensation and Bad protein products in H9c2 cells. The increased cellular sizes, DNA fragmentation, nuclear condensation, and Bad of H9c2 cells treated with P. gingivalis were all significantly reduced after pre-administration of CsA. Conclusion: Our findings suggest that the activity of calcineurin signal pathway may be initiated by P. gingivalis and further lead to cell hypertrophy and death in culture H9c2 myocardial cells
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