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以柿叶为材料,以总多酚的提取率为考察指标,采用Folin-Ciocalteu法对柿叶总多酚含量进行了测定,并采用超声技术通过单因素实验(乙醇浓度、料液比、温度及时间)和正交实验对柿叶中多酚类物质的提取工艺进行探讨.确定柿叶中多酚类物质的最佳超声提取工艺条件为:用40%的乙醇溶液,按1:40的料液比,在50℃下提取20min.在此条件下总多酚的提取率可达5.69%. 相似文献
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研究了提取溶剂、温度、时间、料液比4个因素对山葡萄籽中原花青素得率的影响。确定最佳提取工艺:以70%丙酮为提取荆,在60℃条件下,提取120min,料液比为1:7,原花青素的得率为2.31% 相似文献
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超声波法提取槐花中黄酮的最佳工艺研究 总被引:54,自引:3,他引:51
本文探讨了影响超声波法槐花中黄酮提取率的主要因素,最后用正交法确定了好的提取工艺,并与常规热回流提取法作了比较研究。结果表明:超声波法优于常规热回流提取法。超声法的最佳提取条件为:使用60%乙醇,在温度75℃料液比1:15条件下提取30min,连续提取2次,黄酮的总提取率可达99.84%。 相似文献
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超临界CO2萃取刺葡萄籽原花青素的工艺研究 总被引:1,自引:0,他引:1
刺葡萄(Vitis davidii Foex.)是属于葡萄属东亚种群的一个种,在湖南西部和南部的山区分布广泛,资源丰富,其果实酸甜、风味浓,但其果粒小,种子多,从种子中提取天然活性物质——原花青素的前景可能更为广阔。目前关于刺葡萄的研究报道少,为此本文以“紫秋”刺葡萄种子为原料,采用单因素试验和正交试验,探讨了超临界CO2萃取刺葡萄籽原花青素的工艺。研究结果表明,超临界CO2萃取刺葡萄籽原花青素的适宜工艺条件为:萃取压力30MPa,萃取温度55℃,料液比1:0.8,60%的乙醇为夹带剂,在此条件下,原花青素的产率为17.58 mg/100g,纯度可达89.7%。 相似文献
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利用超声波辅助提取籽瓜皮中多酚类物质并用高效液相色谱检测提取液的主要成分,同时对提取液的抑菌作用进行了研究。结果表明,最优提取工艺为提取时间35 min,乙醇浓度70 m L/100 m L,提取温度60℃,料液比1∶12。提取液的主要成分为没食子酸。0.4 mg/m L的籽瓜多酚提取液在大肠杆菌平面培养皿上产生明显的抑菌圈。籽瓜多酚提取液对大肠杆菌的最低抑菌浓度是0.05 mg/m L。 相似文献
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超声波法提取荷叶多酚工艺研究 总被引:9,自引:0,他引:9
研究利用超声波辅助提取荷叶中多酚类化合物的最佳条件,考察了超声作用时间、提取次数、料液比和乙醇体积分数等因素对荷叶多酚提取率的影响,并在单因素实验的基础上进行正交实验,确定其优化工艺条件为:乙醇体积分数60%,作用时间15 m in,料液比为1:14,提取次数为4次。 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