42 research outputs found

    Stability improvement of multi-beam picosecond–petawatt laser system for ultrahigh peak-power applications

    Get PDF
    Pointing fluctuations of beams reduce the possibility of incoherent or coherent addition for ultrahigh peak power in a multi-beam picosecond–petawatt laser system. Pointing fluctuations on the target were observed on Shenguang Upgrade Petawatt (SGII-UP-Petawatt) beam using a high-speed and high-resolution active pointing stabilization control system. The maximum frequency of the pointing fluctuations was less than 50 Hz, and the amplitude was approximately 2.8 ”rad (RMS). An online test of pointing fluctuations with active stabilization control demonstrated that pointing fluctuations could be reduced to 0.63 ”rad (RMS), approximately one-quarter of that without active stabilization control. The benefits of reduced pointing fluctuation were estimated using a multi-beamlet petawatt laser system; the results demonstrated that peak power could be increased by 51.7% when active stabilization control was used in an eight-beamlet picosecond–petawatt laser system

    Review Article Trends in the Treatment of Hypertension from the Perspective of Traditional Chinese Medicine

    Get PDF
    Hypertension is a major public-health issue. Much consensus has been reached in the treatment, and considerable progress has been made in the field of antihypertensive drugs. However, the standard-reaching rate of blood pressure is far from satisfaction. Considering these data and the seriousness of the effects of hypertension on the individual and society as a whole, both economically and socially, physicians must look for more effective and alternative ways to achieve the target blood pressure. Could treatment of hypertension be improved by insights from traditional Chinese medicine? As one of the most important parts in complementary and alternative therapies, TCM is regularly advocated for lowering elevated blood pressure. Due to the different understanding of the pathogenesis of hypertension between ancient and modern times, new understanding and treatment of hypertension need to be reexplored. Aiming to improve the efficacy of Chinese herbal medicine in treating hypertension, the basis of treatment is explored through systematically analyzing the literature available in both English and Chinese search engines. This paper systematically reviews the trends in emerging therapeutic strategies for hypertension from the perspective of traditional Chinese medicine

    Banxia Baizhu Tianma Decoction for Essential Hypertension: A Systematic Review of Randomized Controlled Trials

    Get PDF
    Objectives. To assess the current clinical evidence of Banxia Baizhu Tianma Decoction (BBTD) for essential hypertension (EH). Search Strategy. Electronic databases were searched until July 2012. Inclusion Criteria. We included randomized clinical trials testing BBTD against placebo, antihypertensive drugs, or combined with antihypertensive drugs against antihypertensive drugs. Data Extraction and Analyses. Study selection, data extraction, quality assessment, and data analyses were conducted according to Cochrane standards. Results. 16 randomized trials were included. Methodological quality of the included trials was evaluated as generally low. 2 trials compared prescriptions based on BBTD using alone with antihypertensive drugs. Meta-analysis showed no significant effect of modified BBTD compared with captopril in systolic blood pressure (MD: −0.75 (−5.77, 4.27); P=0.77) and diastolic blood pressure (MD: −0.75 (−2.89, 1.39); P=0.49). 14 trials compared the combination of BBTD or modified BBTD plus antihypertensive drugs with antihypertensive drugs. Meta-analysis showed there are significant beneficial effect on systolic blood pressure in the combination group compare to the antihypertensive drugs (MD: −4.33 (−8.44, −0.22); P=0.04). The safety of BBTD is uncertain. Conclusions. There is encouraging evidence of BBTD for lowering SBP, but evidence remains weak. Rigorously designed trials are warranted to confirm these results

    Pharmacodynamics, metabolomics and pathological studies on mechanisms of traditional benefits of Angelica sinensis in blood circulation

    Get PDF
    Angelica sinensis is a rich source of medically important active molecules that need in-depth understanding on its action mechanisms. Therefore, through pharmacodynamics, metabolomics, and network pharmacology, the traditional benefits of A. sinensis in blood circulation was studied using 24 randomly selected Sprague-Dawley (SD) rats. Measurement of the blood rheological parameters for whole blood viscosity (WBV) and plasma viscosity (PV), and inspection of the heart and lung tissues pathological changes were undertaken using molecular and bioinformatic techniques. Multivariate statistical analysis and establishment of the model of the relationship between metabolite expression and sample categories to test the prediction of sample categories were performed. Screening was undertaken to find the potential metabolites for A. sinensis to treat blood stasis syndrome and find related metabolic pathways. Active ingredients of A. sinensis and targets and building of an “effect component-target” network was undertaken, A. sinensis was confirmed to improve blood stasis syndrome in rats and improve heart and lung pathology to varying degrees. Compared with the blood stasis model group, A. sinensis significantly reduced WBV and PV in hemorheology (p<0.05, p<0.01) and regulated blood stasis-induced changes in 22 metabolites including alpha-D-glucose, L-isoleucine, creatine and acetylcarnitine, which are involved in the metabolism of linoleic acid, linolenic acid, phenylalanine, ascorbic acid and uronic acid. Using the network pharmacology to build a "component-target-pathway" network of A. sinensis, 62 active ingredients, 169 active proteins and 18 metabolic pathways were obtained, among which linoleic acid metabolism, ascorbic acid and uronic acid metabolism were consistent with the metabolic pathways obtained by metabolomics

    The GRAVITY Coud\'e Infrared Adaptive Optics (CIAO) system for the VLT Interferometer

    Full text link
    GRAVITY is a second generation instrument for the VLT Interferometer, designed to enhance the near-infrared astrometric and spectro-imaging capabilities of VLTI. Combining beams from four telescopes, GRAVITY will provide an astrometric precision of order 10 micro-arcseconds, imaging resolution of 4 milli-arcseconds, and low and medium resolution spectro-interferometry, pushing its performance far beyond current infrared interfero- metric capabilities. To maximise the performance of GRAVITY, adaptive optics correction will be implemented at each of the VLT Unit Telescopes to correct for the effects of atmospheric turbulence. To achieve this, the GRAVITY project includes a development programme for four new wavefront sensors (WFS) and NIR-optimized real time control system. These devices will enable closed-loop adaptive correction at the four Unit Telescopes in the range 1.4-2.4 {\mu}m. This is crucially important for an efficient adaptive optics implementation in regions where optically bright references sources are scarce, such as the Galactic Centre. We present here the design of the GRAVITY wavefront sensors and give an overview of the expected adaptive optics performance under typical observing conditions. Benefiting from newly developed SELEX/ESO SAPHIRA electron avalanche photodiode (eAPD) detectors providing fast readout with low noise in the near-infrared, the AO systems are expected to achieve residual wavefront errors of \leq400 nm at an operating frequency of 500 Hz.Comment: to be published in Proc. SPIE vol. 8446 (2012

    Demonstration of laser-produced neutron diagnostic by radiative capture gamma-rays

    Get PDF
    We report a new scenario of time-of-flight (TOF) technique in which fast neutrons and delayed gamma-ray signals were both recorded in a millisecond time window in harsh environments induced by high-intensity lasers. The delayed gamma signals, arriving far later than the original fast neutron and often being ignored previously, were identified to be the results of radiative captures of thermalized neutrons. The linear correlation between gamma photon number and the fast neutron yield shows that these delayed gamma events can be employed for neutron diagnosis. This method can reduce the detecting efficiency dropping problem caused by prompt high-flux gamma radiation, and provides a new way for neutron diagnosing in high-intensity laser-target interaction experiments

    Stereoselective Separation and Acute Toxicity of Tau-Fluvalinate to Zebrafish

    No full text
    Tau-fluvalinate (TFLV) is one of the most potent chiral synthetic pyrethroids to control a wide range of pests in agricultural fields, especially in apiary. In this study, two stereoisomers of TFLV were fully separated by high-performance liquid chromatography (HPLC) with a semipreparative chiral column using cellulose-tris(3,5-dimethylphenylcarbamate) as chiral stationary phase and n-hexane and 2-propanol (96/4, v/v) as mobile phase at a flow rate of 2.5 mL min−1. The (+)-stereoisomer was first eluted by detecting with an optical rotation detector. After obtaining pure single stereoisomer of TFLV, acute toxicities of each isomer and TFLV standard to zebrafish were evaluated. The results showed that the (+)-stereoisomer exhibited 273.4 times higher toxicity than the (−)-stereoisomer and 6.7 times higher than TFLV standard, according to their LC50 values at 96 h after exposure. This indicates that the toxicity of TFLV mainly originates from (+)-stereoisomer. These results are very helpful to prepare single stereoisomer of chiral pesticides and evaluate their different toxicological effects to aquatic organisms

    Drought resistance of ten ground cover seedling species during roof greening.

    No full text
    Roof greening is an important national policy for maintaining the hydrological balance in China; however, plant growth is limited by drought stress. This study aims to identify strong drought resistant plant species for roof greening from ten common species: Paeonia lactiflora, Hemerocallis dumortieri, Meehania urticifolia, Iris lactea var. chinensis, Hylotelephium erythrostictum, Sedum lineare, Iris germanica, Cosmos bipinnata, Hosta plantaginea, and Dianthus barbatus. By controlling the soil relative water content (RWC), we designed three treatments: moderate drought stress (40±2% 75±2%). After the seedlings were provided different levels of water, their membrane permeability (MP), chlorophyll concentration (Chl), and superoxide dismutase (SOD), peroxidase (POD) and ascorbate peroxidase (APX) activity were measured. Finally, the membership function method was used to assess the drought resistance of these species. The results showed that C. bipinnata and M. urticifolia were not suitable for moderate or severe drought stress and did not survive. The other species presented variations in physiological and biochemical parameters. The MP of He. dumortieri, I. lactea and Ho. plantaginea showed minor changes between the well-watered control and drought stress. Most of the species showed reduced SOD activity under moderate drought stress but increased activity under severe stress. All of the plant species showed decreases in the protective enzymes POD and APX with increasing drought stress. The membership function method was applied to calculate the plant species' drought resistance, and the following order of priority of the roof-greening plant species was suggested: He. dumortieri > I. germanica > I. lactea > D. barbatus > Hy. erythrostictum > S. lineare > Ho. plantaginea > P. lactiflora
    corecore