Research on the microbial limit verification test of tacrolimus capsules

目的按2010版《中国药典》的要求探讨他克莫司胶囊微生物限度检测方法。方法选取5种具有代表性的微生物菌悬液,用常规法、稀释法、膜过滤法或其相结合的方法分别对他克莫司胶囊进行微生物验证试验。结果细菌总数用膜过滤法稀释1∶10,霉菌和酵母菌用膜过滤法稀释1∶1 000,检测后回收率均能达到70%以上。结论避免采用单一常规法或膜过滤法进行微生物限度检测,使实验科学合理,提高工作效率,更加规范性。Objective To research the microbial limit verification test of tacrolimus capsules according to the requirements of the 2010-edition Chinese Pharmacopoeia.Methods Five types of representative microbial bacterial suspension were selected and then microbial verification tests on tacrolimus capsules through the conventional method,the dilution method,the membrane filtration method or a combination of the above methods respectively were carried out.Results Both of the recovery rates were more than 70% when the total number of bacterial was detected by the membrane filtration method as per 1∶ 10 and when mould and yeast were detected by the membrane filtration method as per 1∶ 1 000.Conclusion Microbial limit test through the single conventional method or membrane filtration method is avoided so as to ensure scientific and reasonable experiment,improve work efficiency and achieve normalization

Study on expression,purification and identification of DNA terminal binding protein Ku from mycobacterium smegmatis

目的构建耻垢分枝杆菌末端结合蛋白ku原核表达载体,并进行表达纯化及酶学测定。方法以耻垢分枝杆菌STr.MC2 155基因组dnA为模板,PCr法扩增ku基因,构建PQE-30-ku重组质粒,在表达宿主菌E.COlI M15中诱导表达蛋白,nI2+-nTA亲和层析柱纯化,最后通过凝胶迁移电泳实验测定ku蛋白与5′粘末端、3′粘末端和平末端3种不同末端dnA结合情况。结果成功构建了ku原核表达载体PQE-30-ku,并能在宿主菌E.COlI M15中表达,纯化后具有结合不同末端dnA的酶活性。结论 ku基因克隆到原核宿主菌中能进行表达、纯化,纯化后的蛋白具有结合不同末端dnA的生物学活性,为分枝杆菌非同源末端连接的研究奠定了基础。Objective To construct the prokaryotic expression vector of Ku binding protein of mycobacterium smegmatis terminal,and expressed determination of purification and characterization.Methods Ku gene was amplified from Mycobacterium smegmatis str.MC2 155 genomic DNA by PCR and then cloned into expression vector pQE-30.Finally the recombinant plasmid was expressed in E.coli M15.After induction by IPTG,the fusion protein of Ku was produced,the protein was purified by Ni2+-NTA afinity chromatography,detected it by EMSA.Results Ku was successfully constructed and expressed in E.coli M15.It could be purified and bind different terminal DNA(5'overhangs,3'overhangs and blunts).Conclusion Ku gene could be cloned into the host bacterium and successfully expressed and purified,the purified protein was biologically active,it could bind different terminal DNA,which might be provide an foundation for further research

Evaluation on skin safety for compound Oxytropis Falcata Bung gel

目的:制备一种外用复方镰形棘豆凝胶剂,并对其皮肤用药的安全性进行评价。方法:选用壳聚糖为凝胶基质制备复方镰形棘豆凝胶剂;用复方镰形棘豆凝胶剂考察豚鼠皮肤致敏性、家兔皮肤刺激试验、急性毒性试验和30d长期毒性试验。结果:复方镰形棘豆凝胶剂对豚鼠无致敏性,对家兔完整皮肤及破损皮肤无刺激;急性毒性试验中家兔体质量变化无差异,未见死亡及中毒反应发生;家兔连续给药30d后凝胶剂低中高剂量组对家兔的一般情况、体质量、脏器系数及病理组织、血液学指标、血液生化学指标均无明显影响,恢复期亦无延迟性毒性反应。结论:制备的复方镰形棘豆凝胶剂是一种安全性较高的外用制剂。OBJECTIVE To prepare a compound of Oxytropis Falcata Bung gel and evaluate its skin safety.METHODSCompound of Oxytropis Falcata Bung gel was prepared with chitosan gel matrix.The gel was used to investigate skin sensitization on guinea pig,skin irritation on rabbit,to perform acute toxicity test and 30 days long term toxicity test on rabbit.RESULTS Compound of Oxytropis Falcata Bung gel had good stability,had no induced allergic reaction on skin of guinea pigs,irritation on skin of rabbits or acute toxicity reaction,no animal death or other toxic reactions.The product had no impacts on general conditions,weight,organ coefficients,histopathlolgocal changes,hematological indexes,or blood biochemistry.The delayed toxicity reaction was not shown after drug administration.CONCLUSION Compound of Oxytropis Falcata Bung gel is an external product with high safety.中国人民解放军第一七五医院青年苗圃基金课题(编号:11Y012

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies