长江三峡地区优势植物的化学元素含量特征

分析了三峡地区１６种优势植物２０个元素的自然含量特征。〉１０００μｇ．ｇ＾－１的元素有Ｃａ,Ｋ和Ｍｇ,１００－１０００μｇ．ｇ＾－１的元素有Ａｌ,Ｐ,Ｓｉ,Ｆｅ,Ｓ和Ｍｎ,１０－１００μｇ．ｇ．＾－１的元素有Ｎａ,Ｓｒ,Ｚｎ,Ｂ,〈１０μｇ．ｇ＾－１的元素有Ｔｉ,Ｃｕ,Ｎｉ,Ｃｒ,Ｍｏ,Ｃｄ和Ｖ。     

运用油松年轮揭示承德市硫及重金属污染的历史

本文利用油松年轮研究了承德市逢１８００年以来大气污染的历史过程,结果表明：避署出庄油松年轮内Ｓ含量自本世纪初开始升高,比１９世纪初增加１－２倍,至７０－８０年代达３－５倍,而在最近８－１０年则达到１０倍以上,其中碧峰门古松木质部年轮内Ｓ含量由４０－５０μｇ．ｇ＾－１达到目前的５７２．９μｇ．ｇ＾－１,从而指示出承德市大气ＳＯ２浓度由城市化初期的＜０．１ｍｇ．ｍ＾－３增加到目前的３０ｍｇ．ｍ＾－３,     

承德市油松针叶硫及重金属含量动态及其与大气SO2之间的关系

本文分析了承德市油松（ＰｉｎｕｓｔａｂｕｔａｅｆｏｒｍｉｓＣａｒｒ．）针叶硫和重金属含量变化及其与大气ＳＯ＿２浓度之间的相关性,探讨了油松针叶对大气ＳＯ＿２的生物监测作用,结果认为：植物Ｓ含量生长末期＞休眠期＞生长初期＞生长旺盛期（ｐ＜０．００１）;重金属中Ｐｂ表现为类似的规律,Ｓ和Ｐｂ含量分别从０．７５ｍｇ·ｇ￣（－１）和０．７μｇ·ｇ￣（－１）上升到１．５８ｍｇ·ｇ￣（－１）和２．０μｇ·ｇ￣（－１）。Ｎｉ变化不明显;Ｚｎ、Ｃｕ和Ｆｅ呈下降趋势,但Ｚｎ在休眠期略有回升。Ｍｎ在休眠期最高,但生长期也很高,其余季节相对较低。这种变化特点与大气中ＳＯ＿２和总悬浮颗植物（ＴＳＰ）的变化趋势基本一致;油松针叶Ｓ含量与大气ＳＯ＿２浓度之间具有很显著的相关性,其中火车站监测点生长季节相关公式Ｙ＝－０．０２６３＋０．０９６５Ｘ（ｒ＝０．８９１１,ｐ＜０．００１）;城区Ｙ＝０．０１２６＋０．０６１８Ｘ（ｒ＝０．７８４１,ｐ＜０．０１）。利用后者可对整个承德市区的大气ＳＯ＿２污染状况进行生物监测。     

新疆呼图壁种牛场地区13种优势植物水溶性盐分的含量特点及数量分析

通过对新疆呼图壁种牛场地区１３种耐盐植物水溶性盐分含量的分析,结果阐述了盐分分布和积累的特点：１）大部分植物在盐分含量水平上是：Ｎａ＾＋〉Ｋ＾＋〉Ｍｇ＾２＋〉Ｃａ＾２＋,Ｃｌ＾－〉ＳＯ４＾２－〉ＨＣＯ３＾－〉ＣＯ３＾２－,Ｎａ＾＋超过２００００μｇ／ｇ,Ｃａ＾２＋不足８００μｇ／ｇ;Ｃｌ＾－达４．１６％,ＣＯ３＾２－仅为０．１１％。全盐量平均为２５．８１％;２）ＣＯ３＾２－、ＨＣＯ３＾－和Ｃａ＾２     

水稻对硒吸收,分布及硒与硅共施效应

水稻幼苗根吸收的＾７５Ｓｅ在顶叶分布较多,以下各叶依次减少,但根内积累更多,当Ｙｏｓｈｉｄａ营养液加入０．１和０．３μｇ／ｍｌ亚硒酸钠,根吸收＾３２Ｐ,幼苗长高并生根;但经０．６μｇ／ｍｌ处理后幼苗生长受抑制,叶片失绿。     

黑曲霉生产β—葡萄糖苷酶发酵条件的研究

经多项式回归分析,研究了不同浓度Ｎ源、Ｃ源、无机盐等对酶产量的影响,确定出最佳培养基配方为：麸皮４．９％,（ＮＨ４）２ＳＯ４０．４％,ＫＨ２ＰＯ４０．２９％,ＣａＣｌ２０．０５％,ＭｇＳＯ４·７Ｈ２Ｏ０．０４％,ＦｅＳＯ４·７５ｍｇ·Ｌ＾－ＺｎＣｌ２１．４ｍｇ·Ｌ＾－,０．２％油酸钠。并对培养温度１时间、培养基初妈ｐＨ、通气量、接种量、接种方式等培养条件进行优化,使黑曲霉生产β－葡萄糖苷酶的产量由     

滇池太湖新银鱼的生长特性与资源量关系的研究

为了滇池中太源新银鱼（ＮｅｏｓａｌａｎｘｔａｉｈｕｅｎｓｉｓＣｈｅｎ）达到稳产,高产,优质,高效的目的,管理部门急需寻求一个合理的资源平衡点,经３１个月的连续采样调查,应用ＶｏｎＢｅｒｔａｌａｎｆｆｙ生长方程,得到太湖新银鱼１９８９年和１９９０年生长方程分别为：Ｌ＝６．７０（１－ｅ＾－０．１９８（ｔ－０．２２５）,Ｗ＝１．７８（１－ｅ＾－０．１９８（ｔ－０．２２５））＾３和Ｌ＝７．４８（１－ｅ＾－     

中温碱性脂肪酶的研究：Ⅲ.扩展青霉PF868变株碱性脂肪酶的纯化及其…

扩展青霉ＰＦ８６８变株发酵液经硫酸铵盐析和Ｓｅｐｈａｄｅｘ－Ｇ－２００及Ｓｅｐｈａｒｏｓｅ４Ｂ柱层析纯化,获得纯化倍数为３２．４的酶粉。该酶分子量为２３４４２Ｄａｌ,酶学特性表明：该酶的最适作用温度为３２℃,５０℃保温３０ｍｉｎ仍保留５０％酶活性,最适ｐＨ为９．０,作用ｐＨ稳定范围在７．０－１０．０之间,Ｃａ＾２＋和Ｍｇ＾２＋对酶有激活作用,Ｆｅ＾２＋,Ｃｕ＾２＋和Ｍｎ＾２＋酶活力有抑制作用。     

影响高山红景天细胞悬浮培养中细胞生长和红景天苷积累的几个…

高山红景天细胞悬浮培养过程中３ｍｇ·Ｌ＾－１６－ＢＡ,０．３ｍｇ·Ｌ＾－１ＮＡＡ,６０ｍｍｏｌ·Ｌ＾－１氮源、０．５￣１．２５ｍｍｏｌ·Ｌ－１ＫＨ２ＰＯ４和２０ｍｇ·Ｌ＾－１蛋白胨,较适合于细胞生长和红景天苷的积累。在适宜的接种量下细胞培养２４ｄ后,生物量达１４．０４ｇ·Ｌ＾－１,干细胞中红景天苷含量为５．６６ｍｇ·ｇ＾－１。     

黑曲霉生产β-葡萄糖苷酶发酵条件的研究产

经多项式回归分析,研究了不同浓度Ｎ 源、Ｃ 源、无机盐等对酶产量的影响,确定出最佳培养基配方为：麸皮４ ．９ ％ ,（ＮＨ４）２ＳＯ４ ０ ．４ ％ ,ＫＨ２ＰＯ４ ０ ．２９ ％ ,ＣａＣｌ２ ０ ．０５ ％ ,ＭｇＳＯ４·７Ｈ２Ｏ０ ．０４ ％ ,ＦｅＳＯ４·７Ｈ２ Ｏ５ｍｇ·Ｌ－ １ ,ＺｎＣｌ２ １ ．４ｍｇ·Ｌ－ １ ,０ ．２ ％ 油酸钠．并对培养温度、时间、培养基初始ｐＨ、通气量、接种量、接种方式等培养条件进行优化,使黑曲霉生产β葡萄糖苷酶的产量由１７Ｕ·ｍｌ－ １ 增至２１ ．３Ｕ·ｍｌ－ 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.