28,286 research outputs found

    Contributions of pollutants from North China Plain to surface ozone at the Shangdianzi GAW station

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    International audienceRegional ozone pollution has become one of the top environmental concerns in China, especially in those economically vibrant and densely populated regions, such as North China region including Beijing. To address this issue, surface ozone and ancillary data over the period 2004?2006 from the Shangdianzi Regional Background Station in north China were analyzed. Due to the suitable location and valley topography of the site, transport of pollutants from the North China Plain was easily observed and quantified according to surface wind directions. Regional (polluted) and natural (clean) background ozone concentrations were obtained by detailed statistic analysis. Contribution of pollutants from North China Plain to surface ozone at SDZ was estimated by comparing ozone concentrations observed under SW wind conditions and that under NE wind conditions. The average daily accumulated ozone contribution was estimated to be 240 ppb·hr. The average regional contributions to surface ozone at SDZ from the North China Plain were 21.8 ppb for the whole year, and 19.2, 28.9, 25.0, and 10.0 ppb for spring, summer, autumn, and winter, respectively. The strong ozone contribution in summer led to disappearance of the spring ozone maximum phenomenon at SDZ under winds other than from the WNN to E sectors. High winter NOx concentrations in the North China Plain caused negative ozone contribution in winter

    Gaseous pollutants in Beijing urban area during the heating period 2007–2008: variability, sources, meteorological, and chemical impacts

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    Gaseous pollutants, NO<sub>y</sub>/NO<sub>x</sub>, SO<sub>2</sub>, CO, and O<sub>3</sub>, were measured at an urban site in Beijing from 17 November 2007 to 15 March 2008. The average concentrations (with ± 1σ) of NO, NO<sub>2</sub>, NO<sub>x</sub>, NO<sub>y</sub>, CO, SO<sub>2</sub>, and O<sub>3</sub> were 29.0 ± 2.7 ppb, 33.7 ± 1.4 ppb, 62.7 ± 4.0 ppb, 72.8 ± 4.5 ppb, 1.99 ± 0.13 ppm, 31.9 ± 2.0 ppb, and 11.9 ± 0.8 ppb, respectively, with hourly maxima of 200.7 ppb, 113.5 ppb, 303.9 ppb, 323.2 ppb, 15.06 ppm, 147.3 ppb, and 69.7 ppb, respectively. The concentrations of the pollutants show "saw-toothed" patterns, which are attributable mainly to changes in wind direction and speed. The frequency distributions of the hourly mean concentrations of NO<sub>y</sub>, SO<sub>2</sub>, CO, and O<sub>3</sub> can all be decomposed in the two Lorentz curves, with their peak concentrations representing background levels under different conditions. During the observation period, the average ratio NO<sub>x</sub>/NO<sub>y</sub> was 0.86 ± 0.10, suggesting that the gaseous pollutants in Beijing in winter are mainly from local emissions. Data of O<sub>3</sub>, NO<sub>z</sub>, and NO<sub>x</sub>/NO<sub>y</sub> indicate that photochemistry can take place in Beijing even in the cold winter period. Based on the measurements of O<sub>3</sub>, NO<sub>x</sub>, and NO<sub>y</sub>, ozone production efficiency (OPE) is estimated to be in the range of 0–8.9 (ppb ppb<sup>−1</sup>) with the mean(± 1σ) and median values being 1.1(± 1.6) and 0.5 (ppb ppb<sup>−1</sup>), respectively, for the winter 2007–2008 in Beijing. This low OPE would cause a photochemical O<sub>3</sub> source of 5 ppb day<sup>−1</sup>, which is small but significant for surface O<sub>3</sub> in winter in Beijing. Downward transport of O<sub>3</sub>-rich air from the free troposphere is the more important factor for the enhancement of the O<sub>3</sub> level in the surface layer, while high NO level for the destruction of O<sub>3</sub>. The concentrations of SO<sub>2</sub>, CO, and NO<sub>x</sub> are strongly correlated among each other, indicating that they are emitted by some common sources. Multiple linear regression analysis is applied to the concentrations of NO<sub>y</sub>, SO<sub>2</sub>, and CO and empirical equations are obtained for the NO<sub>y</sub> concentration. Based the equations, the relative contributions from mobile and point sources to NO<sub>y</sub> is estimated to be 66 ± 30 % and 40 ± 16 %, respectively, suggesting that even in the heating period, mobile sources in Beijing contribute more to NO<sub>y</sub> than point sources

    The Effect of Cognitive Behavioral Therapy on Depression, Anxiety, and Stress in Patients With COVID-19: A Randomized Controlled Trial.

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    Background: As a public health emergency of international concern, the COVID-19 outbreak has had a tremendous impact on patients' psychological health. However, studies on psychological interventions in patients with COVID-19 are relatively rare. Objectives: This study examined the effectiveness of Cognitive Behavioral Therapy (CBT) in relieving patients' psychological distress during the COVID-19 epidemic. Methods: Ninety-three eligible participants selected by cluster sampling were randomized to an intervention group (N = 47) and a control group (N = 46). Participants in the control group received routine treatment according to the Chinese Management Guidelines for COVID-19, while participants in the intervention group received routine treatment with additional CBT. The Chinese Version of Depression Anxiety and Stress Scale-21 (DASS-21) was used to evaluate depression, anxiety, and stress for all participants at baseline and post-intervention. Two-sided t-test, and proportion tests were used to examine the differences between the intervention and control group for each DASS-21 indicator. Univariate linear regression was used to examine the association between chronic disease status and change in each DASS-21 indicator after intervention. Two-way scatter plots were generated to show the association of the length of hospital stay and the changes of each DASS-21 indicator by intervention and control groups. Results: Significant decreases in means were found for scales of depression, anxiety, stress and total DASS-21 in both intervention (p 0.05). Compared with participants with chronic disease, participants with no chronic disease had a significantly larger reduction of total DASS-21 scale (coefficient = -4.74, 95% CI: -9.31; -0.17).The length of hospital stay was significantly associated with a greater increase in anxiety scale in the intervention group (p = 0.005), whilst no significant association was found in the control group (p = 0.29). Conclusions: The patients with COVID-19 experienced high levels of anxiety, depression and stress. Our study result highlights the effectiveness of CBT in improving the psychological health among patients with COVID-19, also suggests that CBT should be focused on patients with chronic disease and those who have longer hospital stays. These results have important implications in clinical practice in improving psychological health in the context of COVID-19 pandemic. Trial Registration: ISRCTN68675756. Available at: http://www.isrctn.com/ISRCTN68675756

    Resonance decay effects on anisotropy parameters

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    We present the elliptic flow v2v_2 of pions produced from resonance decays. The transverse momentum pTp_T spectra of the parent particles are taken from thermal model fits and their v2v_2 are fit under the assumption that they follow number-of-constituent-quark (NCQ) scaling expected from quark-coalescence models. The v2v_2 of pions from resonance particle decays is found to be similar to the measured pion v2v_2. We also propose the measurement of electron v2v_2 as a means to extract open-charm v2v_2 and investigate whether a thermalized system of quarks and gluons (a quark-gluon plasma) is created in collisions of Au nuclei at RHIC.Comment: 5 pages, 4 figure

    Biological impacts of 'hot-spot' mutations of hepatitis B virus X proteins are genotype B and C differentiated

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    AIM: To investigate the biological impacts of “hot-spot” mutations on genotype B and C HBV X proteins (HBx). METHODS: Five types of “hot-spot” mutations of genotype B or C HBV X genes, which sequentially lead to the amino acid substitutions of HBx as I127T, F132Y, K130M+V131I, I127T+K130M+V131I, or K130M+V131I+F132Y, respectively, were generated by means of site-directed mutagenesis. To evaluate the anti-proliferative effects, HBx or related mutants’ expression vectors were transfected separately to the Chang cells by lipofectamine, and the cells were cultured in hygromycin selective medium for 14 d, drug-resistant colonies were fixed with cold methanol, stained with Giemsa dyes and scored (increase of the colonies indicated the reduction of the anti-proliferation activity, and vice versa). Different types of HBx expression vectors were co-transfected separately with the reporter plasmid pCMVÎČ to Chang cells, which were lysed 48 h post-transfection and the intra-cellular ÎČ-galactosidase activities were monitored (increase of the ÎČ-galactosidase activities indicated the reduction of the transactivation activity, and vice versa). All data obtained were calculated by paired-samples t-test. RESULTS: As compared to standard genotype B HBx, mutants of I127T and I127T+K130M+V131I showed higher transactivation and anti-proliferative activities, while the mutants of F132Y, K130M+V131I, and K130M+V131I+F132Y showed lower activities. As compared to standard genotype C HBx, I127T mutant showed higher transactivation activity, while the other four types of mutants showed no differences. With regard to anti-proliferative activity, compared to standard genotype C HBx, F132Y and K130M+V131I mutants showed lower activities, and K130M+V131I +F132Y mutant, on the other hand, showed higher activity, while the mutants of I127T and I127T+K130M+V131I showed no differences. CONCLUSION: “Hot-spot” mutations affect the anti-proliferation and transactivation activities of genotype B and/or C HBx, and the biological impacts of most “hot-spot” mutations on HBx are genotype B and C differentiated.published_or_final_versio

    Identification of Urinary Biomarkers for Exercise-Induced Immunosuppression by iTRAQ Proteomics

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    Purpose: To identify noninvasive immune biomarkers of exercise-induced immunosuppression using the iTRAQ proteomics technique. Methods: Fifteen healthy males were recruited and subjected to a four-week incremental treadmill running training program. After each week of training, WBC counts and CD4+ and CD8+ lymphocytes were measured to monitor the immune function status. iTRAQ proteomics technology was used to identify differential proteins and their characteristics in urine. Results: Our data showed that the WBC counts, CD4+ lymphocytes, and CD4+/CD8+ ratio decreased by more than 10% after four weeks of training, suggesting exercise-induced immunosuppression. A total of 1854 proteins were identified in urine during the incremental running using the iTRAQ technology. Compared with the urine before training, there were 89, 52, 77, and 148 proteins significantly upregulated and 66, 27, 68, and 114 proteins significantly downregulated after each week, respectively. Among them, four upregulated proteins, SEMG-1, PIP, PDGFRL, and NDPK, increased their abundance with the increased exercise intensity. Bioinformatics analysis indicates that these proteins are involved in stress response and immune function. Conclusion: Four weeks of incremental treadmill running induced immunosuppression in healthy males. By using iTRAQ proteomics, four proteins in the urine, SEMG-1, PIP, PDGFRL, and NDPK, were found to increase incrementally with the increased exercise intensity, which have the potential to be used as noninvasive immune biomarkers of exercise-induced immunosuppression

    Limited Comp Handover Algorithm For LTE-Advanced

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    Coordinated multipoint (CoMP) transmission and reception is the key technique in LTE-Advanced to improve the cell-edge throughput and/or system throughput. Joint processing (JP) in CoMP technology provides multiple data transmission points for each user among multiple cooperated radio base stations. Hard handover mechanism is adopted to be used in LTE-Advanced. Standard hard handover algorithm could not satisfy the concept of JP in CoMP in LTE-A due to the constraint of single connection for each user at any time. While the radio resources in the system are fixed, the more multiple data connections a user has, the more radio resources are used for the extra data connections, thus the lower capacity a system becomes. Therefore a new handover algorithm that not only supports JP in CoMP but also takes system capacity into consideration in LTE-A system is necessary. This paper proposes a new handover algorithm known as Limited CoMP Handover Algorithm to support JP in CoMP and overcome the system capacity issue. System performance of Limited CoMP Handover Algorithm is evaluated and compared with open literature handover algorithm via simulation in this paper. The simulation results show that Limited CoMP Handover Algorithm outperforms open literature handover algorithm by having shorter system delay and less system load whilst maintaining a higher system throughput in a high congested network

    Development of Competency Indexes to Assess Nursing Postgraduate's Tutor

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    The aim of this study was to develop competency indexes assessing nursingpostgraduate's tutor in China. Based on Iceberg competency theory, a Delphisurvey was carried out. 30 nursing experts in 16 provinces of China wereinvited to rate the importance of indexes and give some comments on thecontent. There were 22 experts taking part in two rounds Delphi study. AKendall's W test also demonstrated experts were well coordinated. Duringthe first round, overall mean scores were high, except for 1 tertiary index.We also added and moved some indexes building on the experts'suggestions. After two rounds, we developed competency indexesappropriate to assess tutots' competencies, consisting of 5 preliminaryindexes, 13 secondary indexes and 68 tertiary indexes. The competencyindexes were validated and scientific, it can be used to assess tutors in China
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