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本试验通过对高氯酸和硫酸体系进行比较,选择香草醛-冰醋酸-高氯酸体系作为测定苦瓜皂甙的合适显色条件,并对体系中各个因素逐一考察,确定比色法测定苦瓜皂甙的条件为:0.2mL冰醋酸,0.8mL高氯酸,5%香草醛.冰醋酸溶液,70℃条件下反应20min。试验以苦瓜皂甙建立了苦瓜皂甙测定回归曲线,线性和稳定性可靠,平均加标回收率100.78%,变异系数为1.910%。 相似文献
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白术提取物对六价铬致人外周血淋巴细胞
抗突变作用研究 总被引:1,自引:0,他引:1
目的:探讨白术提取物抗六价铬的致突变作用。方法:采用人外周血淋巴细胞程序外DNA合成(UDS)试验检测了0.03g、0.015g和0.0075/ml白术提取物对重铬酸钾(含Cr^6+0.31ug/ml)所致淋巴细胞程序外DNA合成的影响。同时检测白术提取物与重铬酸钾的加入顺序对UDS的影响。结果:阳性对照(重铬酸钾,含CCr^6+0.31ug/ml)组CPM值显著高于阴性对照(蒸馏水)组,P〈0.01。白术提取物与重铬酸钾同时加入以及两者间隔2h先后加入均显示白术提取物浓度与CPM值呈显著负相关(P〈0.05),在上述不同加入方法中,白术提取物的各浓度均显示CPM值显著低于阳性对照。结论:白术提取物具有抑制Cr^6+的致突变作用。 相似文献
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生长调节剂对石刁柏悬浮培养细胞的生长和多糖含量的影响 总被引:2,自引:1,他引:1
选取在MS十2,4DI.0ms/L(单位下同)+6-BA0.2培养基上,每30~40d继代1次的一年生长石刁柏(As~(nxv)zllaLLi)愈伤组织无性系,于26士IC下进行无菌悬浮培养,培养基为MS+2,4D0·4+6-BA0.4,每4d换液1次,8~12d继代1次,3个月后用于实验。测定生长(60C下供至恒重)和多糖(0.15g干培养物加3ml水,超声波处理回~2min后匀浆,于90C水浴中置lh,离心,上清液加2倍体积酒精沉淀过夜,取沉淀加入1.5ml水)。多糖测定按苯酚硫酸法(张惟杰.复合多糖生化研究技术.上海:上海科学技术出版社,1987.6)。结果表明:回… 相似文献
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薄层层析-比色法测定降糖安胶囊中胡芦巴皂苷B的含量 总被引:6,自引:1,他引:5
建立薄层层析-比色法测定降糖安胶囊中胡芦巴皂苷B含量的方法。采用硅胶H薄层板,氯仿:甲醇:醋酸:水(25:12:2:2)为展开剂,在碘蒸气中定位,用高氯酸显色,325nm波长处检测,点样量在35ug~385ug范围内呈现良好的线性关系,其回归方程为A=285.6C-1.313,相关系数r=0.9991,平均回收率为96.23%,RSD=1.75%。本法准确,适用于该药的质量控制。 相似文献
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介绍一种测定银杏花粉生活力的方法 总被引:1,自引:0,他引:1
银杏是雌雄异株植物,雌花开放一般晚于雄花。依靠自然传粉产量不高,生产上常采用人工授粉方法以提高结果率。这就需要收集和贮藏花粉,检查花粉生活力。但银杏花粉以常规的花粉发芽试验和Brewbackwack配制的培养基均难以前发。我们用改良的测定种子活力的氯化三苯四氮吐还原法(TTC),同样可以测定银杏花粉的生活力,十分方便。其实验程序如下:取99ml0.05mol.L-1、pH为7.5的磷酸缓冲液,加入0.6gTTC和1ml1%吐温-80,从中取3ml加到盛有50mg花粉的IOInl试管中,放在25℃的光照培养箱中sh后,以80Or·Wu一滴心SWn,花粉下沉,… 相似文献
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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases 相似文献
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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme
responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare
the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show
that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by
distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of
demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least
one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of
the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable
potent antiproliferative synthetic drugs. 相似文献
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The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle. 相似文献
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Meng Miao Gang Deng Xiaobei Xiong Yang Qiu Wenda Huang Meng Yuan Fei Yu Shimei Bai Xi Zhou Xiaolu Zhao 《中国病毒学》2022,37(2):314-317
Highlights
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions. 相似文献
1. The N-terminal tail of histone H3 is specifically cleaved during EV71 infection.
2. Viral protease 3C is identified as a protease responsible for proteolytically processing the N-terminal H3 tail.
3. Our finding reveals a new epigenetic regulatory mechanism for Enterovirus 71 in virus-host interactions. 相似文献
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Dong Liu Xin Wang Yisong Wang Peigang Wang Dongying Fan Sichang Chen Yuguang Guan Tianfu Li Jing An Guoming Luan 《中国病毒学》2018,33(5):402-409
Rasmussen’s encephalitis (RE) is a rare pediatric neurological disorder, and the exact etiology is not clear. Viral infection may be involved in the pathogenesis of RE, but conflicting results have reported. In this study, we evaluated the expression of both Epstein-Barr virus (EBV) and human herpes virus (HHV) 6 antigens in brain sections from 30 patients with RE and 16 control individuals by immunohistochemistry. In the RE group, EBV and HHV6 antigens were detected in 56.7% (17/30) and 50% (15/30) of individuals, respectively. In contrast, no detectable EBV and HHV6 antigen expression was found in brain tissues of the control group. The co-expression of EBV and HHV6 was detected in 20.0% (6/30) of individuals. In particular, a 4-year-old boy had a typical clinical course, including a medical history of viral encephalitis, intractable epilepsy, and hemispheric atrophy. The co-expression of EBV and HHV6 was detected in neurons and astrocytes in the brain tissue, accompanied by a high frequency of CD8+ T cells. Our results suggest that EBV and HHV6 infection and the activation of CD8+ T cells are involved in the pathogenesis of RE. 相似文献
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Shen Jia-Yuan Li Man Xie Lyu Mao Jia-Rong Zhou Hong-Ning Wang Pei-Gang Jiang Jin-Yong An Jing 《中国病毒学》2021,36(1):145-148
正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016). 相似文献
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Renfei Lu Xiuming Wu Zhenzhou Wan Yingxue Li Lulu Zuo Jianru Qin Xia Jin Chiyu Zhang 《中国病毒学》2020,35(3):344-347
In conclusion, the novel visual RT-LAMP assay is a simple, rapid, and sensitive approach for detection of SARS-CoV-2, and it is ready for application in primary care and community hospitals or health care centers, and even patients' own houses in response to the current SARS-CoV-2 epidemic because the assay does not require sophisticated equipment and skilled personnel. Furthermore, it is also ready to be used in fields for screening samples from wild animals and environments to facilitate the identification of potential intermediate hosts that mediate the cross-species transmission of SARS-CoV-2 from bats to humans. 相似文献