1,162 research outputs found
Phase-Resolved Timing Analysis of GRS 1915+105 in Its {\rho} State
We made a phase-resolved timing analysis of GRS 1915+105 in its {\rho} state
and obtained detailed {\rho} cycle evolutions of the frequency, the amplitude
and the coherence of low-frequency quasi-periodic oscillation (LFQPO). We
combined our timing results with the spectral study by Neilsen et al. to
perform an elaborate comparison analysis. Our analyses show that the LFQPO
frequency does not scale with the inner disk radius, but it is related to the
spectral index, indicating a possible correlation between the LFQPOs and the
corona. The LFQPO amplitude spectrum and other results are naturally explained
by tying the LFQPO to the corona. The similarities of the spectra of
variability parameters between the LFQPO from {\rho} state and those from more
steady states indicate that the LFQPOs of GRS 1915+105 in very different states
seem to share the same origin.Comment: 21 pages, 4 figures, accepted for publication in Ap
The role of globular heads of the C1q receptor in HPV 16 E2-induced human cervical squamous carcinoma cell apoptosis is associated with p38 MAPK/JNK activation
BACKGROUND Human papillomavirus type 16 (HPV 16) E2 protein is a multifunctional DNA-binding protein. HPV 16 E2 regulates many biological responses, including DNA replication, gene expression, and apoptosis. The purpose of this study was to investigate the relationship among the receptor for globular heads of the human C1q (gC1qR) gene expression, HPV 16 E2 transfection and apoptosis regulation in human cervical squamous carcinoma cells (C33a and SiHa). METHODS gC1qR expression was examined in C33a and SiHa cells using real-time PCR and Western blot analysis. Apoptosis of C33a and SiHa cells was assessed by flow cytometry. C33a and SiHa cell viability, migration and proliferation were detected using the water-soluble tetrazolium salt (WST-1) assay, a transwell assay and 3H-thymidine incorporation into DNA (3H-TdR), respectively. RESULTS C33a and SiHa cells that were transfected with a vector encoding HPV 16 E2 displayed significantly increased gC1qR gene expression and p38 mitogen-activated protein kinase (p38 MAPK)/c-jun N-terminal kinase (JNK) activation as well as up-regulation of cellular apoptosis, which was abrogated by the addition of gC1qR small interfering RNA (siRNA). Furthermore, the changes in C33a and SiHa cell viability, migration and proliferation that were observed upon HPV 16 E2 transfection were abrogated by SB203580 (a p38 MAPK inhibitor) or SP600125 (a JNK inhibitor) treatment. CONCLUSION These data support a mechanism whereby HPV 16 E2 induces apoptosis by silencing the gC1qR gene or inhibiting p38 MAPK/JNK signalling in cervical squamous cell carcinoma.This study was supported by grants from the National Natural Science Foundation of China (No. 81000251) and the Nanjing Medical Science and Technique Development Foundation
Three-level Back-to-Back Converter Simulation for Wind Turbine Energy Source
AbstractThis paper presents the simulation of three-level back-to-back converter for wind turbine energy source. For this paper, it will be focused on wind turbine energy source and determined the voltage from wind turbine energy source being regular value. The operation of the converter can be simulated by using MATLAB/SIMULINK program. Moreover, the voltage and current of the converter can be properly controlled by SVPWM. The simulation results shown that the output current waveform have signal distortion less than the input current waveform, and also the output voltage waveform is more than the input as well. Therefore, this converter can convert the voltage and current from the AC to DC and from the DC to AC for more performance, and it can be connected to the grid
Effects of Thiophene Units on Substituted Benzothiadiazole and Benzodithiophene Copolymers for Photovoltaic Applications
Two conjugated copolymers, P1 and P2, comprising of benzodithiophene and 5, 6-dioctyloxy-benzothiadiazole (DOBT) derivatives with/without thiophene unit, were synthesized via Stille cross-coupling polymerization reaction. These copolymers are promising for the applications in BHJ solar cells due to their good solubilities, proper thermal stability and moderate hole mobility as well as low bandgap. The photovoltaic properties of the copolymers were investigated based on the blend of the different polymer/PC71BM weight ratio under AM1.5G illumination, 100 mW/cm2. The device with ITO/PEDOT:PSS/P2: PC71BM (1:2, w/w)/Ca/Al gave relatively better photovoltaic performance, with a power conversion efficiency of 1.55%
A Systematic Study on Energy Dependence of Quasi-Periodic Oscillation Frequency in GRS 1915+105
Systematically studying all the RXTE/PCA observations for GRS 1915+105 before
November 2010, we have discovered three additional patterns in the relation
between Quasi-Periodic Oscillation (QPO) frequency and photon energy, extending
earlier outcomes reported by Qu et al. (2010). We have confirmed that as QPO
frequency increases, the relation evolves from the negative correlation to
positive one. The newly discovered patterns provide new constraints on the QPO
models
Magnesium Lithospermate B Protects Cardiomyocytes from Ischemic Injury Via Inhibition of TAB1–p38 Apoptosis Signaling
Danshen has been used in traditional Chinese medicine for hundreds of years to treat cardiovascular diseases. However, its precise cardioprotective components and the underlying mechanism are still unclear. In the present study, we demonstrated that in a rat model of acute myocardial infarction, the treatment with magnesium lithospermate B (MLB), the representative component of phenolic acids in Danshen, significantly reduced the infarct size and the blood lactate dehydrogenase level. In contrast, tanshinone IIA, the representative component of lipophilic tanshinones in Danshen, had no such protective effects. Moreover, in the simulated ischemia cell model, MLB treatment considerably increased the cell viability and reduced the sub-G1 population and the apoptotic nuclei, indicating its anti-apoptotic effect. Further mechanism study revealed that the ischemia-induced p38 phosphorylation was abolished by MLB treatment. Interestingly, MLB specifically inhibited the TGFβ-activated protein kinase 1-binding protein 1 (TAB1) mediated p38 phosphorylation through disrupting the interaction between TAB1 and p38, but it did not affect the mitogen-activated protein kinase 3/6 mediated p38 phosphorylation. In conclusion, the present study identifies MLB as an active component of Danshen in protecting cardiomyocytes from ischemic injury through specific inhibition of TAB1–p38 apoptosis signaling. These results indicate TAB1–p38 interaction as a putative drug target in treating ischemic heart diseases
Association of p53 rs1042522, MDM2 rs2279744, and p21 rs1801270 polymorphisms with retinoblastoma risk and invasion in a Chinese population.
Single nucleotide polymorphisms (SNPs) of p53 rs1042522, MDM2 rs2279744 and p21 rs1801270, all in the p53 pathway, which plays a crucial role in DNA damage and genomic instability, were reported to be associated with cancer risk and pathologic characteristics. This case-control study was designed to analyse the association between these SNPs and retinoblastoma (RB) in a Chinese Han population. These SNPs in 168 RB patients and 185 adult controls were genotyped using genomic DNA from venous blood. No significant difference was observed in allele or genotypic frequencies of these SNPs between Chinese RB patients and controls (all P > 0.05). However, the rs1042522 GC genotype showed a protective effect against RB invasion, as demonstrated by event-free survival (HR = 0.53, P = 0.007 for GC versus GG/CC). This effect was significant for patients with a lag time >1 month and no pre-enucleation treatment (P = 0.007 and P = 0.010, respectively), indicating an interaction between p53 rs1042522 and clinical characteristics, including lag time and pre-enucleation treatment status. Thus, the rs1042522 SNP may be associated with RB invasion in the Han Chinese population; however, further large and functional studies are needed to assess the validity of this association
Consequences, measurement, and evaluation of the costs associated with adverse drug reactions among hospitalized patients in China
BACKGROUND: Adverse drug reactions (ADRs) are a leading cause of morbidity in developed countries and represent a substantial burden on health-care resources. Many countries spent 15% to 20% of their hospital budgets to treat drug complications. However, few studies have measured the pharmacoeconomic effects of ADRs on hospitalized patients in China. The study estimates the costs of ADRs as identified from the spontaneous voluntary reports completed from healthcare professionals. To do so, we calculate these costs, determine the sum of Medicare payments and their proportion of total healthcare spending, and evaluate the incidence of ADRs, characteristics of hospitalized ADR patients, and outcomes of ADRs in China. METHODS: This retrospective survey studied patients who experienced ADRs during their hospitalization at a Chinese tertiary-care teaching hospital. The patients were divided into group A and group B according to general ADRs and serious ADRs in Provisions for Adverse Drug Reaction Monitoring and Reporting. The direct costs included treatment fees, inspection fees, laboratory fees, materials fees, bed charges, drug charges, nursing care, meals, and other expenses and the sunk-cost losses were calculated according to the hospital information system (HIS). Indirect costs of ADR treatment were calculated according to the human capital approach. The epidemiological characteristics of ADRs were evaluated. RESULTS: 2739 were diagnosed with ADR during the study period, which translates to an ADR rate of 0.81%. The total socioeconomic loss from 2739 cases of ADR was estimated at ¥817401.69, consisting of direct costs of ¥603252.81 and indirect costs of ¥214148.88. On average, the costs per patient amounted to ¥196.10 in group A, ¥7032.29 in group B. The sum of medicare payment and proportion were ¥219061.13 (65.23%) and ¥105422.02 (39.42%) in group A and B. The ADR incidence in old-age patients was significantly higher than in other age groups (P < 0.0001). The most common drug class associated with ADRs represented antibiotics (957 patients, 34.94%). CONCLUSIONS: The costs of especially severe ADRs could not be ignored, and in this hospital 0.13% of patients were diagnosed with ADRs associated with relatively higher direct costs than who suffered from mild ADRs, largely due to extended hospitalization
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