目的:筛选中药活性成分作为鼠伤寒沙门氏菌致病性岛III(Salmonella pathogenicity island III,SPI-3)潜在毒力抑制剂。方法:通过分子对接技术明确中药成分与SPI-3中的MgtC蛋白的潜在结合关系。使用β-半乳糖苷酶测定法评估中药成分对mgt...目的:筛选中药活性成分作为鼠伤寒沙门氏菌致病性岛III(Salmonella pathogenicity island III,SPI-3)潜在毒力抑制剂。方法:通过分子对接技术明确中药成分与SPI-3中的MgtC蛋白的潜在结合关系。使用β-半乳糖苷酶测定法评估中药成分对mgtC转录的影响。最后,通过评估细菌生长曲线和关键代谢基因的转录水平研究药物对细菌生长的影响。结果:所有27个候选中药成分均显示出与MgtC结合的潜力。阿魏酸、对羟基肉桂酸、牛蒡子苷和掌叶防己碱使mgtC的转录活性降低了15%以上。这四个成分对mgtC转录的最低抑制浓度分别为:阿魏酸16μM;对羟基肉桂酸40μM;牛蒡子苷80μM;掌叶防己碱160μM。此外,我们证实这四种成分均未抑制细菌生长。结论:在本研究中,我们建立了一种基于β-半乳糖苷酶测定法的鼠伤寒沙门氏菌毒力抑制剂筛选方法。以SPI-3为靶标,筛选了27种中药成分,发现有4种对鼠伤寒沙门氏菌毒力具有潜在的强效抑制作用。这为未来从草药中开发新型抗生素提供了先导化合物。这种方法也可用于筛选其他致病菌的毒力抑制剂。展开更多
The detection of manganese(Mn)in steel by laser-induced breakdown spectroscopy(LIBS)provides essential information for steelmaking.However,self-absorption greatly disrupts the LIBS spectral lines of Mn with high conte...The detection of manganese(Mn)in steel by laser-induced breakdown spectroscopy(LIBS)provides essential information for steelmaking.However,self-absorption greatly disrupts the LIBS spectral lines of Mn with high content.In this study,to minimize self-absorption for Mn spectral lines in LIBS,laser-induced fluorescence(LIF)was applied.Compared with conventional LIBS,the self-absorption factors(α)of Mn I 403.08,403.31,and 403.45 nm lines were reduced by 90%,88%,and 88%,respectively;the root mean square errors of crossvalidation were decreased by 88%,85%,and 87%,respectively;the average relative errors were reduced by 93%,90%,and 91%,respectively;and average relative standard deviations were decreased by 29%,32%,and 33%,respectively.The LIBS-LIF was shown to successfully minimize the self-absorption effect and spectral intensity fluctuation and improve detection accuracy.展开更多
为了探讨蚯蚓遗传多样性与土壤环境的关系,2015年6-10月在河北地区进行蚯蚓资源调查和样品采集,利用PCR技术扩增线粒体基因16S r DNA、ND1序列,分析了该区蚯蚓优势种类天锡杜拉蚓（Drawida gisti）的遗传多样性。结果表明：来自河北23...为了探讨蚯蚓遗传多样性与土壤环境的关系,2015年6-10月在河北地区进行蚯蚓资源调查和样品采集,利用PCR技术扩增线粒体基因16S r DNA、ND1序列,分析了该区蚯蚓优势种类天锡杜拉蚓（Drawida gisti）的遗传多样性。结果表明：来自河北23个采集点的研究样本,16S、ND1全部DNA序列的平均单倍型多样性分别为0.76和0.64,平均核苷酸多样性分别为0.042和0.039,群体间平均遗传距离分别为0.045和0.054。土壤性质显著影响种群的遗传变异水平。展开更多
A potential strategy for patients with estrogen receptor(ER)-positive breast cancer is necessary to replace neoadjuvant chemotherapy which has limited benefit.Neoadjuvant endocrine therapy(NAE)has been indicated to be...A potential strategy for patients with estrogen receptor(ER)-positive breast cancer is necessary to replace neoadjuvant chemotherapy which has limited benefit.Neoadjuvant endocrine therapy(NAE)has been indicated to be a favorable alternate approach to downstage large or locally advanced breast cancer in ER-positive,human epidermal growth factor receptor 2(HER2)-negative(ER+/HER2-)patients,especially postmenopausal women.Previous studies have demonstrated the efficacy of various endocrine agents in NAE.Aromatase inhibitors(AIs)have proven superiority over tamoxifen as a suitable choice to optimize treatment efficacy.Fulvestrant was recently reported as an effective agent,similar to AIs.Furthermore,the addition of targeted agents exerts synergistic antiproliferative effects with endocrine agents and rapidly improves response rates in both endocrine sensitive and resistant tumors.The neoadjuvant platform provides a unique opportunity to define the appropriate strategy and address the mechanisms of endocrine resistance.In addition,the predictive value of biomarkers and genomic assays in NAE is under investigation to evaluate individual effects and validate biomarker-based strategies.In this review,we discuss the most relevant evidence on the potential of NAE for ER+breast cancer.The current understanding also offers new insights into the identification of the optimal settings and valuable predictive tools of NAE to guide clinical treatment decisions and achieve beneficial therapeutic effects.展开更多
基金supported by the National Natural Science Foundation of China(82072247 and 82374154)National Key Research and Development Project of China(2022YFC3502300)+2 种基金Natural Science Foundation of Beijing Municipality(L222150)Tianjin Chasesun Pharmaceutical(BUCM-2022-JS-FW-076)Zhuhai Yourun Co.,Ltd.(BUCM-2023-JS-KF-018)
文摘目的:筛选中药活性成分作为鼠伤寒沙门氏菌致病性岛III(Salmonella pathogenicity island III,SPI-3)潜在毒力抑制剂。方法:通过分子对接技术明确中药成分与SPI-3中的MgtC蛋白的潜在结合关系。使用β-半乳糖苷酶测定法评估中药成分对mgtC转录的影响。最后,通过评估细菌生长曲线和关键代谢基因的转录水平研究药物对细菌生长的影响。结果:所有27个候选中药成分均显示出与MgtC结合的潜力。阿魏酸、对羟基肉桂酸、牛蒡子苷和掌叶防己碱使mgtC的转录活性降低了15%以上。这四个成分对mgtC转录的最低抑制浓度分别为:阿魏酸16μM;对羟基肉桂酸40μM;牛蒡子苷80μM;掌叶防己碱160μM。此外,我们证实这四种成分均未抑制细菌生长。结论:在本研究中,我们建立了一种基于β-半乳糖苷酶测定法的鼠伤寒沙门氏菌毒力抑制剂筛选方法。以SPI-3为靶标,筛选了27种中药成分,发现有4种对鼠伤寒沙门氏菌毒力具有潜在的强效抑制作用。这为未来从草药中开发新型抗生素提供了先导化合物。这种方法也可用于筛选其他致病菌的毒力抑制剂。
基金financially supported by National Natural Science Foundation of China(No.62005078)the Scientific Research Foundation of Hunan Provincial Education Department(No.21B0477)the Natural Science Foundation of Hunan Province(No.2020JJ5206)。
文摘The detection of manganese(Mn)in steel by laser-induced breakdown spectroscopy(LIBS)provides essential information for steelmaking.However,self-absorption greatly disrupts the LIBS spectral lines of Mn with high content.In this study,to minimize self-absorption for Mn spectral lines in LIBS,laser-induced fluorescence(LIF)was applied.Compared with conventional LIBS,the self-absorption factors(α)of Mn I 403.08,403.31,and 403.45 nm lines were reduced by 90%,88%,and 88%,respectively;the root mean square errors of crossvalidation were decreased by 88%,85%,and 87%,respectively;the average relative errors were reduced by 93%,90%,and 91%,respectively;and average relative standard deviations were decreased by 29%,32%,and 33%,respectively.The LIBS-LIF was shown to successfully minimize the self-absorption effect and spectral intensity fluctuation and improve detection accuracy.
文摘为了探讨蚯蚓遗传多样性与土壤环境的关系,2015年6-10月在河北地区进行蚯蚓资源调查和样品采集,利用PCR技术扩增线粒体基因16S r DNA、ND1序列,分析了该区蚯蚓优势种类天锡杜拉蚓（Drawida gisti）的遗传多样性。结果表明：来自河北23个采集点的研究样本,16S、ND1全部DNA序列的平均单倍型多样性分别为0.76和0.64,平均核苷酸多样性分别为0.042和0.039,群体间平均遗传距离分别为0.045和0.054。土壤性质显著影响种群的遗传变异水平。
基金Supported by the National Natural Science Foundation of China,No.81773083
文摘A potential strategy for patients with estrogen receptor(ER)-positive breast cancer is necessary to replace neoadjuvant chemotherapy which has limited benefit.Neoadjuvant endocrine therapy(NAE)has been indicated to be a favorable alternate approach to downstage large or locally advanced breast cancer in ER-positive,human epidermal growth factor receptor 2(HER2)-negative(ER+/HER2-)patients,especially postmenopausal women.Previous studies have demonstrated the efficacy of various endocrine agents in NAE.Aromatase inhibitors(AIs)have proven superiority over tamoxifen as a suitable choice to optimize treatment efficacy.Fulvestrant was recently reported as an effective agent,similar to AIs.Furthermore,the addition of targeted agents exerts synergistic antiproliferative effects with endocrine agents and rapidly improves response rates in both endocrine sensitive and resistant tumors.The neoadjuvant platform provides a unique opportunity to define the appropriate strategy and address the mechanisms of endocrine resistance.In addition,the predictive value of biomarkers and genomic assays in NAE is under investigation to evaluate individual effects and validate biomarker-based strategies.In this review,we discuss the most relevant evidence on the potential of NAE for ER+breast cancer.The current understanding also offers new insights into the identification of the optimal settings and valuable predictive tools of NAE to guide clinical treatment decisions and achieve beneficial therapeutic effects.
