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。     

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 2 5MPa ,温度 5 0℃ ,CO2 流量 30kg h ,萃取时间15 0min ,大豆磷脂夹带剂乙醇的流量为 3kg h ,得率分别为 15 72 %和 1 95 4 %。     

永州香樟叶精油的提取及其季节含量变化

本实验以永州香樟叶为原料,优化了超临界CO2萃取制备香樟叶精油的工艺条件。结果显示,超临界CO_2萃取香樟叶精油的最适工艺条件为:CO_2流量20 L/h,萃取压力18 MPa,萃取温度46℃,萃取时间1.6 h,在此工艺条件下永州香樟叶精油萃取率可达到98.37%,高出索氏提取法42.97%,高出水蒸气蒸馏法26.69%。当加入0.6%CO_2流量的乙醇作为夹带剂萃取时间缩短了26 min,可进一步节省能耗。同时研究了永州香樟叶精油在一年内各季度的变化规律,发现夏秋两季精油含量水平较高,而春冬两季较少,在1月含量达到最低。     

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。     

肾叶天胡荽精油的超临界CO2萃取、成分分析及杀虫活性初探

采用正交实验设计,对肾叶天胡荽（Hydrocotyle wigordi Maxim．）精油超临界CO2萃取条件进行了优化,并用GC—MS分析技术对精油的化学成分进行了鉴定,初步探讨了肾叶天胡荽精油对小菜蛾2龄幼虫的触杀活性。结果表明,肾叶天胡荽精油超临界CO2萃取的最佳条件为萃取压力35MPa、萃取温度50℃、解析压力5MPa、解析温度40℃、萃取时间75min、CO2流量34—36L·h^-1,精油得率最高可达5．32％。从精油中共鉴定出19种成分,总相对含量达到89．266％,主要成分为邻苯二甲酸二辛酯（64．302％）。用超临界CO2萃取技术提取的肾叶天胡荽精油对小菜蛾2龄幼虫有一定的触杀作用,20g·L^-1精油对小菜蛾2龄幼虫的24h校正死亡率高达90．00％。     

土荆芥精油的超临界CO2萃取条件及杀虫活性的初步研究

采用超临界CO2萃取技术,应用正交设计方法,以萃取率为评价指标,优化土荆芥精油的提取工艺,并对土荆芥精油的杀虫活性进行初步研究。结果表明,超临界CO2萃取土荆芥精油的较佳萃取条件为:粒度为60-80目,萃取压力为20MPa,萃取温度为55℃,解析压力为6 MPa,解析温度为60℃,萃取时间为65 min,CO2流量为34-36 L.h-1,在此条件下的萃取率为7.92%,而水蒸气蒸馏法仅为0.45%;此外采用熏蒸方法,土荆芥精油对家蝇成虫和黄曲条跳甲成虫的致死中浓度(LC50)分别为1.6102和1.3232 mg.L-1,采用点滴法,触杀致死中量(LD50)分别为166.4336和306.8287μg.头-1。     

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     

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.     

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.     

Enterovirus 71 3C proteolytically processes the histone H3 N-terminal tail during infection

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.     

Detection of EBV and HHV6 in the Brain Tissue of Patients with Rasmussen’s Encephalitis

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.     

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).     

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.