社鼠核型的研究

社鼠核型的研究ＫＡＲＹＯＴＹＰＥＳＯＦＮＩＶＩＶＥＮＴＥＲＣＯＮＦＵＣＩＡＮＵＳ（ＲＯＤＥＮＴＩＡ：ＭＵＲＩＤＡＥ）关键词核型Ｃ带Ｇ带ＡｇＮＯＲｓ社鼠ＫｅｙｗｏｒｄｓＫａｒｙｏｔｙｐｅ,Ｃｂａｎｄｉｎｇ,Ｇｂａｎｄｉｎｇ,ＡｇＮＯＲＳ,Ｎ...     

紫叶酢浆草的组织培养

1　植物名称　紫叶酢浆草 (Ｏｘａｌｉｓｖｉｏｌａｃｅａ)。2　材料类别　叶片、叶柄。3　培养条件　培养基有 :( 1 )ＭＳ ＮＡＡ 0 .5ｍｇ·Ｌ- 1 (单位下同 ) ;( 2 )ＭＳ ＩＢＡ 1 .0 ＮＡＡ 0 .5 ;( 3)ＭＳ ＩＢＡ 1 .0 ＮＡＡ 0 .5 ＫＴ 1 .0 ;( 4 )ＭＳ ＩＢＡ 0 .5 ＮＡＡ 0 .5 ＫＴ 1 .0。以上培养基含蔗糖 2 5 ｇ·Ｌ- 1 、琼脂 0 .5 %,ｐＨ 5 .8。培养温度为 2 2～ 2 5℃ ,照光 1 2ｈ·ｄ- 1 ,光照度为 2 0 0 0ｌｘ。4　生长与分化情况4.1　叶柄的分化情况　取盆栽紫叶酢浆草叶片与叶柄 ,流水洗净 ,用 70 %酒精浸洗 30ｓ…     

长白松人工林生态系统营养元素的分配格局和积累规律

对长白松人工林生态系统营养元素的分配格局和积累规律研究表明,乔木层不同器官营养元素含量为叶＞枝＞根＞干皮＞干材;同化器官──针叶中养分含量为Ｎ＞Ｋ＞Ｃａ＞Ｐ＞Ｍｇ;吸收器官──根中养分含量为Ｃａ＞Ｎ＞Ｋ＞Ｐ＞Ｍｇ;人工林生态系统中的养分含量为土壤＞凋落层＞草本层＞灌木层＞乔木层,乔木层养分贮量和积累率分别为８８．７９％和７６．４３％;长白松林生态系统中植物对Ｎ、Ｐ的吸收较强烈．     

达乌尔黄鼠染色体银染核仁组织者分析

达乌尔黄鼠染色体银染核仁组织者分析ＡＮＡＬＹＳＩＳＯＮＣＨＲＯＭＯＳＯＭＥＳＡｇ－ＮＯＲＳＯＦＣＩＴＥＬＬＵＳＤＡＵＲＩＣＵＳＫｅｙｗｏｒｄｓＣｉｌｅｌｌｕｓｄａｕｒｉｃｕｓ;Ｃｈｒｏｍｏｓｏｍｅ;Ａｇ－ＮＯＲ达乌尔黄鼠（ｃｉｌｅｌｌｕｓｄａｕｒｉｃ...     

Cr6+污染对菱叶中矿质元素含量的影响

研究Ｃｒ＾６＋污染后菱浮水叶和沉水叶中Ｃｒ、Ｋ、Ｍｇ、Ｆｅ、Ｍｎ、Ｚｎ、Ｃｕ、Ｍｏ元素的含量,结果显示：Ｃｒ含量随培养浓度的上升而上升,Ｋ、Ｍｇ随培养浓度的上升而下降,Ｆｅ含量随培养浓度的上升而出现先上升后下降,Ｍｎ、Ｚｎ、Ｃｕ、Ｍｏ与Ｃｒ＾６＋的培养浓度无明显的相关关系。     

缙云山常绿阔叶林四川大头茶果实中矿质营养元素含量及季节动态

本文测定了缙云山常绿阔叶林中四川大头茶果实中Ｎ,Ｐ,Ｋ,Ｃａ,Ｍｇ,Ｃｕ,Ｚｎ,Ｆｅ,Ｍｎ９种矿质营养元素的含量,研究了这些元素的季节吸收特点与繁殖分配,并探讨了这些元素与某些土壤化学因素之间的关系,结果表明：四川大头茶果实在生长期内矿质营养元素含量随季节而变化,各元素平均含量顺序为：Ｎ＞Ｋ＞Ｃａ＞Ｍｇ＞Ｐ＞Ｍｎ＞Ｆｅ＞Ｚｎ＞Ｃｕ。土壤中化学因子与四川大头茶果实中常量元素含量之间的关系密切,果实中Ｎ含量受土壤中Ｎ,Ｐ,Ｋ含量的综合影响,土壤有机质最终会影响到果实中Ｎ,Ｐ,Ｋ,Ｃａ的吸收,矿质元素的果实繁殖分配量与果实净生物生产量分配之间不存在特定的比例关系。果实元素分配所占比例的大小顺序为Ｐ＞Ｎ＞Ｋ＞Ｃａ＞Ｆｅ＞Ｍｇ＞Ｍｎ＞Ｚｎ＞Ｃｕ。     

鼎湖山南亚热带常绿阔叶林植物营养元素含量分配格局研究

在鼎湖山南亚热带常绿阔叶林中,植物叶片营养元素含量为Ｎ ０．９４６％－２．５３５％,Ｐ ０．０３０－０．１２７％,Ｋ ０．６１４％－１．８３３％,Ｃａ ０．４４２％－１．９９５％,Ｍｇ ０．０２４％－０．１８８％。叶片各营养养元素间相关性较差,仅Ｐ与Ｍｇ及Ｍｇ与Ｋ之间存在显著的线性相关。叶片Ｎ元素平均含量在各层中的序列为：乔木Ⅲ〉乔木Ⅱ〉乔木Ⅰ〉灌木〉藤本〉草本;其它营养元素浓度随层次分配的规律性     

北方阔叶树木固氮与非固氮树种间营养元素含量的差异及数量化分类

研究了北方阔叶树木中固氮和非固氮树种间养分元素含量的差异及季节变化趋势．在生长旺盛期到落叶期固氮和非固氮树种叶片之间Ｎ、Ｍｇ含量始终存在明显差异;固氮树种叶片中Ｎ、Ｋ含量降低的趋势明显低于非固氮树种,所研究的其它５个元素和灰分的季节变化率即累积的趋势则高于非固氮树种．在Ｆ检验和Ｔ检验的基础上,选择Ｎ、Ｐ、Ｍｇ、Ｓｉ４个营养元素为参数进行的数量化分类,成功地区分了固氮和非固氮树种．     

趋化因子CX_3C——Fractalkine的结构与功能

趋化因子是一类结构和功能相关的多肽超家族 ,分子量为 7～ 1 5ｋＤ ,分子序列中多数有四个半胱氨酸残基 (Ｃｙｓ或Ｃ)。根据Ｎ末端两个保守Ｃｙｓ的排列方式 ,趋化因子被分为Ｃ、ＣＣ、ＣＸＣ和ＣＸ3Ｃ四个亚家族。Ｆｒａｃｔａｌｋｉｎｅ(ＦＫＮ) [1] 是ＣＸ3Ｃ亚家族的唯一成员。过去认为 ,ＦＫＮ具有趋化功能 ,参与白细胞特别是吞噬细胞和淋巴细胞的游走和活化 ,同时表现有粘附作用 ,介导细胞间粘附。近年的研究发现 ,ＦＫＮ还具有其它多种潜在功能 ,如增强细胞粘附、介导免疫损伤等。1 .ＦＫＮ的结构及其受体ＣＸ3ＣＲ1ＦＫＮ编码基因…     

隆安县荔枝适生地层研究

本文研究隆安县不同地层的土壤元素含量对荔枝生产的影响。通过分析地层的岩石、土壤、荔枝叶矿物元素含量及其与产量的相关性,确定隆安县荔枝适生地层。提出可能促进隆安县荔枝高产的有ＳｉＯ２和Ｍｇ元素;隆安荔枝生产中,土壤的Ｚｎ、Ｂ及Ｎ、Ｐ、Ｋ均感不足;引起荔枝中毒造成地层劣势可能是因为Ａｌ、Ｃｕ、Ａｓ和Ｍｎ含量过高;荔枝含硫量很低,可能为低硫植物。在上述基础上,进行隆安县荔枝生产布局和管理建议。     

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.