魔芋葡甘露聚糖-丙烯腈接枝共聚反应的研究

本研究以硝酸铈铵作为引发剂,探讨反应时间、反应温度、引发剂浓度和单体用量对魔芋葡甘露聚糖-丙烯腈接枝共聚反应的影响;并利用扫描电镜等分析技术对接枝共聚物结构与性能的关系作了初步探。结果表明,接枝共聚物的粘度比反应前提高了2—4倍;溶胶的相对稳定性提高了近4倍;接枝共聚物成膜更为均匀、细密;且气泡明显减少。     

黑豆魔芋果冻的研制

以黑豆和魔芋精粉为主要原料,以白砂糖、柠檬酸、卡拉胶和果冻粉等食用凝胶剂为辅料,对黑豆汁、凝胶剂、白砂糖以及柠檬酸的浓度等工艺条件进行了研究。通过正交试验得出最佳产品配方为:黑豆汁5%、魔芋精粉0.2%、卡拉胶0.6%、白砂糖6%、柠檬酸0.2%。制作出一种香味独特,风味可口,营养丰富且具有较好保健功能的黑豆魔芋果冻。     

β-甘露聚糖酶产生菌R10的产酶特性研究

分离出一株能利用魔芋飞粉和魔芋精粉生产β-甘露聚糖酶的解淀粉芽孢杆菌(Bacillus amyloliquefaciens)R10。其摇瓶最适发酵条件为：魔芋飞粉1％(m／m),魔芋精粉2％(m／m),160r/min,37℃培养10h。实验结果表明β-甘露聚糖酶的最适作用温度为60℃,最适作用pH为6．0。魔芋葡甘露聚糖经酶降解后为一系列低聚糖。     

接枝共聚法合成多彩水晶花泥

采用水溶性引发剂,以N'N'-亚甲基双丙烯基酰胺为交联剂,表面活性剂为助剂进行丙烯酸和彩色聚丙烯酸脂接枝共聚,合成多彩水晶花泥。制得的共聚物可吸水100倍以上,形成水凝胶呈水晶多棱结构,色彩艳丽且色泽牢固、不溶于水、无毒、无污染,可用于家庭花卉无土培养、室内插花装饰等。本文讨论引发剂、交联剂、助剂等合成条件对共聚物性能的影响。     

增容剂甲基丙烯酸丁酯接枝聚丙烯的研究

以甲基丙烯酸丁酯(BMA)为接枝单体,过氧化苯甲酰(BPO)为引发剂,采用固相接枝技术对聚丙烯(PP)进行改性,制备了BMA接枝PP(PP-g-BMA)。研究了接枝反应工艺条件对接枝率的影响,采用傅立叶变换红外光谱表征与分析了PP-g-BMA,并对PP-g-BMA在PP/聚对苯二甲酸乙二酯(PET)共混物中的增容作用进行了验证。结果表明,当反应温度为130℃、引发剂的质量分数为6%、单体BMA质量分数为10%,接枝反应3 h,成功制得了接枝率为3.75%PP-g-BMA;PP-g-BMA可明显改善PP/PET共混物的界面相容性,相对于PP-g-BMH,其增容的PP/PET共混物的力学性能和加工流变性能更好。     

黄原胶与丙烯酰胺接枝共聚反应的研究

以过硫酸铵为引发剂,在N2气保护下,研究了黄原胶(XG)与丙烯酰胺(AM)的接枝共聚反应.考察了单体浓度、引发剂浓度、反应温度和反应时间等因素对接枝率及接枝效率的影响,探讨了过硫酸铵引发黄原胶接枝丙烯酰胺共聚反应的基本规律.采用红外光谱(FT-IR)、X射线粉末衍射(XRD)对接枝共聚物的结构进行研究,用热重分析(TGA)法表征了产物的热性能,并初步探讨了接枝机理.     

淀粉类保水剂合成过程中皂化介质对吸水性的影响

合成适用于工业生产的淀粉接枝共聚物保水剂。系统地考察了淀粉接枝共聚物在皂化过程中,分散介质对产物吸水性能的影响。     

不同品种魔芋精粉中氨基酸含量分析研究

花魔芋和白魔芋精粉中均含有 18种水解氨基酸和 18种游离氨基酸 ,前者水解氨基酸的总量为 2 .4 4 % ,其中必须氨基酸质量分数为 0 .6 2 % ,游离氨基酸总量为 1.10 % ,其中游离必须氨基酸质量分数为 0 .33% ;后者水解氨基酸总量为 2 .0 1% ,其中必须水解氨基酸质量分数为 0 .5 6 % ,游离氨基酸总量为 0 .4 1% ,其中必须游离氨基酸质量分数为 0 .13%。提示白魔芋和花魔芋精粉中氨基酸含量略有差异 ,但此差异不大 ,其品质 ,营养价值及特性等主要取决于魔芋精粉中主要成分葡甘聚糖的含量     

接枝共聚法合成多彩水晶花泥

采用水溶性引发剂,以Ｎ‘Ｎ’－亚甲基双丙烯基酰胺为交联剂,表面活性剂为助剂进行丙烯酸和彩色聚丙烯酸脂接枝共聚,合成多彩水晶花泥,制得的共聚物可吸水１００倍以上,形成水凝胶呈水晶多棱结构,色彩艳丽且色泽牢固、不溶于水、无毒、无污染,可用于家庭花卉无土培养、室内插花装饰等。本文讨论引发剂、交联剂、助剂等合成条件对共聚物性能的影响。     

高吸水性淀粉的性能

本文综述了淀粉接技丙烯腈的皂化,金属离子氧化反应引发接技共聚的机理,皂化后淀粉接技丙烯腈的吸水性能与淀粉分子聚合度的关系,吸水性能与接技共聚物中聚丙烯腈聚合度的关系,高吸水性淀粉中所含水的特性以及淀粉、聚丙烯、及其共聚物的热行为。     

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.