超临界CO2萃取洋葱挥发油工艺研究

本实验采用超临界CO2萃取技术从冻干洋葱粉中萃取挥发油。以洋葱挥发油得率为考察指标,经单因素及正交试验,考察了萃取温度、萃取压力、CO2流量、萃取时间4个因素对超临界CO2流体萃取的影响。结果表明萃取压力20 MPa,萃取温度35℃,CO2流量为14 kg/h的条件下萃取2.5 h为最佳工艺,洋葱挥发油得率达0.53%。     

超临界CO2萃取鱼腥草的挥发油成分

从萃取的压力、温度、流量和时间等条件探讨超临界CO2萃取对鱼腥草(Houttuynia cordata Thunb.)挥发油萃取率的影响,确定最佳萃取条件为萃取压力20mPa、温度35℃、CO2流量40kg/h和萃取时间80min,鱼腥草挥发油得率为1．76％。而水蒸气蒸馏提取和石油醚提取的得率分别为0．05％和0．08％。超临界CO2法萃取的鱼腥草挥发油收率高,萃取时间短。     

超临界CO_2和微波辅助萃取艾叶挥发油工艺的研究

通过超临界CO2萃取均匀设计实验和微波辅助萃取艾叶挥发油的正交实验比较,考察影响提取的主要因素,寻求最佳萃取工艺。超临界CO2萃取最佳工艺条件为:萃取压力16MP,萃取温度31℃,CO2流量20kg/h和时间80min,得率3.75%;微波萃取最佳工艺条件为:辐射功率720w,辐射时间200s,溶剂量400mL,洗涤剂量50mL,得率4.85%。水蒸馏法提取率为1.87%。结果表明超临界CO2和水蒸馏法萃取艾叶挥发油品质最好;微波萃取收率最高,但品质较差。     

超临界CO2萃取石香薷挥发油工艺的研究

石香薷（Molsa chinensis）为多年生草本植物,具有重要的药用价值。本文首次探讨了超临界CO2萃取的压力,温度,流量,时间等条件对石薷挥发油收率的影响,确定其最佳萃取条件,萃取压力15MPa,温度45℃,CO2流量25kg/h和90min,得率为3.56%,水蒸气蒸馏提取得率为1.62%,石油醚提取得率为1.87%,结果表明超临界CO2萃取挥发油比后二者质优,收率大大提高,萃取时间短,无溶剂残留。     

生姜的超临界CO2提取分离工艺的研究

本文研究了超临界CO2流体萃取生姜的工艺,探讨了萃取压力、温度扣时问等因素对生姜萃取率的影响,通过正交实验确定了生姜超临界CO2流体萃取最佳工艺：生姜原料切成薄片,含水率15％以下,萃取条件为压力24Mpa、温度40℃、时间2h。     

超临界二氧化碳萃取鸢尾油的工艺条件研究

本文采用L9（3^4）正交实验考察了二氧化碳超临界萃取中萃取压力、萃取温度和萃取时间对鸢尾精油提取率的影响。结果表明各影响因子的影响顺序为：压力〉时间〉温度;当原料的颗粒度为60-80目、CO2流量为20．0m^3/h时,用超临界二氧化碳萃取鸢尾精油的最佳工艺条件为：萃取压力26．0MPa,萃取温度55．0℃,萃取完成时间为2．5h,此条件下鸢尾香根中鸢尾油的萃取率高达12．71％,得到的精油中鸢尾酮的含量为39．95％,与索氏法和微波提取法相比,超临界萃取具有提取率高和产品质量好的优点。     

均匀设计法优选芝麻油提取新工艺

本文通过超临界CO2提取芝麻油的均匀设计实验和微波和超声波诱导提取芝麻油的正交实验比较,考察影响提取的主要因素,寻求最佳萃取工艺。超临界CO2萃取最佳工艺条件为：压力32MPa,温度60℃,CO2流量31kg／h,萃取时问80min,得率46．39％;微波萃取最佳工艺条件为：溶剂为丙酮,物料与溶剂比例1：7,辐射时间7min,辐射功率810W,得率23．01％。超声波萃取最佳工艺条件为：物料与溶剂比例1：7,溶剂为石油醚,浸泡时间30h,得率23．99％。结果表明超临界CO2萃取芝麻油品质最好,而且萃取也最高,质量最稳定。     

超临界CO2萃取大豆油与大豆磷脂工艺条件研究

应用超临界CO2萃取技术从大豆中直接提取大豆油和纯度为95.98%的大豆磷脂。探讨了超临界CO2萃取的压力、温度、流量、时间等条件对大豆油和大豆磷脂的影响,确定其最佳萃取条件：萃取压力25MPa,温度50℃,CO2流量30kg/h,萃取时间150min,大豆磷脂夹带剂乙醇的流量为3kg/h,得率分别为15.72%和1.954%。     

超临界CO_2萃取当归挥发油及其在烟草中的应用研究

为开发新的天然烟用香料,研究了超临界CO2萃取当归挥发油的工艺,用GC/MS分析了挥发油中的挥发性和半挥发性成分,并用该挥发油进行了卷烟加香试验。结果表明:①超临界CO2萃取当归挥发油的优化工艺条件为:萃取温度40℃、萃取压力45Mpa、萃取时间1.5 h、CO2流量20 L.h-1,分离釜压力8 Mpa,分离釜温度45℃。②当归挥发油共鉴定出29种成分,主要有藁本内酯、丁烯基芙内酯、亚油酸、棕榈酸、油酸以及萜烯类化合物等。③卷烟加香评价结果表明,当归挥发油在丰富烟香、掩盖杂气、改善口感方面有较好的作用。     

超临界CO2萃取去除蛋黄粉中胆固醇和甘油三酯的研究

采用超临界CO2萃取,对去除蛋白黄粉中胆固醇和甘油三酯进行了研究,市购鲜鸡蛋去壳、分别收集湿蛋白和蛋黄,在45℃下分别真空干燥,得蛋白粉和蛋黄粉,取蛋黄粉装入高压釜中,进行超临界CO2循环萃取,通过正交试验得最佳工艺条件是：A萃取压力为31.5MPa,B萃取温度40℃,C被萃取蛋黄粉重300g,D萃取时间3h,所得蛋黄粉中胆固醇和甘油三酯等中性脂的残留量质量分数仅为0.019%,与不含此类旨质的蛋白粉混合,制成几乎不含胆固醇和甘油三酯的高级绿色保健营养食品－－鸡蛋粉。     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

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.     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

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     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

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.     

鸡传染性法氏囊病病毒研究进展

传染性法氏囊病(Infection bursal disease, IBD)是由鸡传染性法氏囊病毒(Infectious bursal disease virus, IBDV)引起的鸡和火鸡的一种高度接触性传染病,给世界各国的禽养殖业带来了巨大损失.自IBDV发现至今新的变异株不断出现,分子结构的改变导致病毒致病力的改变及宿主对疫苗应答的改变,使得传统的疫苗已不能控制其流行,因此各国学者对其基因组结构和功能进行了广泛深入的研究,并积极研制新型有效的疫苗以达到防治的目的.     

Development of a Novel Reverse Transcription Loop-Mediated Isothermal Amplification Method for Rapid Detection of SARS-CoV-2

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.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

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).