红霉素白蛋白纳米粒的制备及体内药动学研究

目的:制备红霉素白蛋白纳米粒,以提高红霉素的生物利用度。方法:采用去溶剂化高压均质法制备红霉素白蛋白纳米粒,以载药量、包封率、粒径及多分散系数为评价指标。通过单因素考察及正交试验进行最佳处方工艺的筛选,并对最佳处方工艺进行表征。SD大鼠随机分成2组,分别尾静脉注射红霉素混悬液与红霉素白蛋白纳米粒,比较药动学参数。结果:当药物与白蛋白比例为1∶3、有机相体积为4 ml、高压均质10次、有机相加入方式为注射器注入、搅拌时间为5 h、搅拌速度为700 r·min^(-1)时,所制备的白蛋白纳米粒性质最优,最佳工艺下包封率为(65.61±1.02)%,载药量为(36.49±1.33)%,平均粒径为(280.71±5.82)nm,多分散系数(PDI)为0.20±0.04,电位为-(11.91±2.29)mV。与原料药相比,白蛋白纳米粒的最大血药浓度(C_(max))提高了5.8倍,血药浓度-时间曲线下面积(AUC_(0→12))提高了5.15倍(P<0.01)。结论:以去溶剂化高压均质法制备的红霉素白蛋白纳米粒制备方法简单,制剂稳定性良好,能显著提高红霉素的体内生物利用度。

Optimization of performance of the KM2A full array using the Crab Nebula

The full array of the Large High Altitude Air Shower Observatory(LHAASO)has been in operation since July 2021.For its kilometer-square array(KM2A),we optimized the selection criteria for very high and ultrahigh energyγ-rays using data collected from August 2021 to August 2022,resulting in an improvement in significance of the detection in the Crab Nebula of approximately 15%,compared with that of previous cuts.With the implementation of these new selection criteria,the angular resolution was also significantly improved by approximately 10%at tens of TeV.Other aspects of the full KM2A array performance,such as the pointing error,were also calibrated using the Crab Nebula.The resulting energy spectrum of the Crab Nebula in the energy range of 10-1000 TeV are well fitted by a log-parabola model,which is consistent with the previous results from LHAASO and other experiments.

Flux variations of cosmic ray air showers detected by LHAASO-KM2A during a thunderstorm on June 10,2021

The Large High Altitude Air Shower Observatory(LHAASO)has three sub-arrays,KM2A,WCDA,and WFCTA.The flux variations of cosmic ray air showers were studied by analyzing the KM2A data during a thunderstorm on June 10,2021.The number of shower events that meet the trigger conditions increases significantly in atmospheric electric fields,with a maximum fractional increase of 20%.The variations in trigger rates(increases or decreases)were found to be strongly dependent on the primary zenith angle.The flux of secondary particles increased significantly,following a trend similar to that of shower events.To better understand the observed behavior,Monte Carlo simulations were performed with CORSIKA and G4KM2A(a code based on GEANT4).We found that the experimental data(in saturated negative fields)were in good agreement with the simulations,assuming the presence of a uniform electric field of-700 V/cm with a thickness of 1500 m in the atmosphere above the observation level.Due to the acceleration/deceleration by the atmospheric electric field,the number of secondary particles with energy above the detector threshold was modified,resulting in the changes in shower detection rate.

Performance of LHAASO-WCDA and observation of the Crab Nebula as a standard candle

The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard candle.The WCDA-1 achieves a sensitivity of 65 mCU per year,with a statistical threshold of 5 cr.To accomplish this,a 97.7%cosmic-ray background rejection rate around 1 TeV and 99.8%around 6 TeV with an ap proximate photon acceptance of 50%is achieved after applying an algorithm to separate gamma-induced showers.The angular resolution is measured using the Crab Nebula as a point source to be approximately 0.45°at 1 TeV and better than 0.2°above 6 TeV,with a pointing accuracy better than 0.05°.These values all match the design specifications.The energy resolution is found to be 33%for gamma rays around 6 TeV.The spectral energy distribution of the Crab Nebula in the range from 500 GeV to 15.8 TeV is measured and found to be in agreement with the results from other TeV gamma ray observatories.

观察早期护理干预对脑梗塞伴偏瘫患者并发症的预防效果

探究早期护理干预对脑梗塞伴偏瘫患者并发症的预防价值。方法:纳入36例脑梗塞伴偏瘫患者进行对比分析,(时间:2019年10月~2020年10月),行护理对比研究,奇偶数组排列分组,对照组(n=18,常规护理),实验组(n=18,早期护理干预),分析并发症发生率、生活质量数据。结果:(1)生活质量:实验组较对照组,显著改善患者生活质量水平,(P<0.05);(2)并发症发生率:实验组较对照组,显著降低患者并发症发生率,(P<0.05)。结论:早期护理干预运用在脑梗塞伴偏瘫患者治疗当中,有效提升患者生活质量,同时还减少了并发症发生率,提高患者的预后水平,临床数据均得到了有效改善,有较高的护理价值。

Prospects for a multi-TeV gamma-ray sky survey with the LHAASO water Cherenkov detector array

The Water Cherenkov Detector Array(WCDA) is a major component of the Large High Altitude Air Shower Array Observatory(LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. WCDA is aimed at the study of TeV γ-rays. In order to evaluate the prospects of searching for TeV γ-ray sources with WCDA, we present a projection of the one-year sensitivity of WCDA to TeV γ-ray sources from TeVCat using an all-sky approach. Out of 128 TeVCat sources observable by WCDA up to a zenith angle of 45°, we estimate that 42 would be detectable in one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei(AGN).