宝天曼自然保护区栓皮栎林生物量和净生产力研究

对河南内乡宝天曼自然保护区４５年生天然次生栓皮栎林的生物量和净生产力的研究表明,栓皮栎林生物量为１６７．６４１７ｔ·ｈｍ－２,其中乔木层为１５８．８３８２ｔ·ｈｍ－２,占总量的９４．７５％;该林净生产力为８．４８８０ｔ·ｈｍ－２·ａ－１,其中乔木层为７．９２５４ｔ·ｈｍ－２·ａ－１,生物量平均相对生长速率为０．０４１．灌木层的生物量和净生产力分别为０．０６９４和０．０４５６ｔ·ｈｍ－２·ａ－１;而草本层的分别为０．１０４１和０．０９０８ｔ·ｈｍ－２·ａ－１．凋落物现存量为８．６３ｔ·ｈｍ－２,凋落物量为５．０３９５ｔ·ｈｍ－２·ａ－１,分别占总量的５．１５％及５９．３７％．净生产量与叶面积指数、叶量成正比关系,而与叶效率呈负相关关系．     

昆明北郊水源保护区圣诞树人工林分生物量及生产力的研究

昆明北郊松华坝水源保护区１０年生圣诞树人工林分生物量为１３７．９２６ｔ／ｈｍ２,净生产量为２４．１２８ｔ／ｈｍ２·ａ,其中乔木层生物量为１３０．４１８ｔ／ｈｍ２,净生产量为１９．３６９ｔ／ｈｍ２·ａ,下木和草本植物生物量和净生产量分别为０．９３５ｔ／ｈｍ２和０．６０９ｔ／ｈｍ２·ａ,枯枝落叶层现存量和林分凋落物量分别为６．５７３ｔ／ｈｍ２和４．１５０ｔ／ｈｍ２·ａ。在林分产量结构方面,１０ｍ以下树干生物量占其总量的９８．３７％,４～１２ｍ之间枝、叶生物量分别占整个枝、叶生物量的８５．５１％和９４．９０％,地下根系在离地面２０ｃｍ深土层内的生物量占总根量的７３．０４％。目前,该类林分群落结构不合理,整体效应较差,保持水土作用未能充分发挥出来。应及时进行间伐,调整群落产量结构;注重对林下地被植物及枯枝落叶层的保护,以提高其综合效益。     

天山云杉林生物量和生产力的研究

对新疆昌吉地区木垒林场天山云杉林的生物量和生产力进行了测定和研究,结果表明,林分总生物量为２１６．１７０ｔ·ｈｍ－２,净生长量为１２．６３４ｔ·ｈｍ－２·年－１．林分生物量在各器官的分配是：干占４８．６８％,枝占１７．７７％,叶占９．８１％,果占０．０３％,根占１８．６％;净生长量的分配是：干占３１．４９％,枝占１．２％,叶占１２．７％,果占０．４６％,根占２６．８７％．     

福建武夷山甜槠群落能量的研究

在生物量、生产力研究基础上,对武夷山甜槠（Ｃａｓｔａｎｏｐｓｉｓ ｅｙｒｅｉ（Ｃｈａｍ ｐ．ｅｘ Ｂｅｎｔｈ．） Ｔｕｔｃｈ．）群落各组分的热值、群落能量现存量、能量年净固定量以及太阳能转化效率进行了研究。结果表明：（１）甜槠群落各组分样品的干重热值具有一定的差异,树皮热值最高,细根热值最低。（２）甜槠群落的能量现存量达７８０５８４．１ ｋＪ·ｍ － ２,其中地上部分为６７８９１３．８ ｋＪ·ｍ － ２,占总量的８６．９８％ ;地下部分为１０１６７０．３ ｋＪ·ｍ － ２,占１３．０２％ 。（３）甜槠群落的能量年净固定量（１９９２年）为２６８５６．２ ｋＪ·ｍ － ２·ａ－ １,林地太阳光合有效辐射能的转化效率为１．２９６％ 。     

鼎湖山针阔叶混交林的第一性生产力研究

本文应用“树木收获法”和“气体分析法”,结合凋落物收集数据,综合测定了鼎湖山针阔叶混交林中的各种群第一性生产力以及群落的光。进一步综合分析表明,该群落的叶面积指数为１１;生物量为２６１ｔ·ｈｍ￣（－２）;总生产力约为１１７．６ｔ·ｈｍ￣（－２）·ａ￣（－１）,光能利用效率为１２％;第一性生产力为２０．９ｔ·ｈｍ￣（－２）·ａ￣（－１）。由于该群落是南亚热带演替系列中间阶段的代表性类型,因而本研究结果有助于了解本地带植被动态过程生产力发展规律和对能量的利用状况。     

鹤山马占相思人工林的生物量和净初级生产力

通过对鹤山马占相思（Ａｃａｃｉａ ｍａｎｇｉｕｍ）人工林的群落结构,生物量、净初级生产力的研究表明,１５龄的马占相思人工林乔木层总生物量为１９６．９４ｔ．ｈｍ＾－２,其中树干为８０．７５ｔ．ｈｍ＾－２,树枝为５５．１４ｔ．ｈｍ＾－２,树叶为１９．６９ｔ．ｈｍ＾－２,根为４１．３６ｔ．ｈｍ＾－２,该人工林１－７龄生物量增长迅速,而７－１１龄的生物量增则相对较慢,１１龄后生物量趋。１１龄马占相思林的净     

武夷山甜槠群落钙,镁的累积和循环

对５１年生甜槠群落Ｃａ、Ｍｇ含量及其生物循环研究表明,甜槠群落现存量中,Ｃａ、Ｍｇ总量分别为１０２９．９６和２３１．３４ｋｇ·ｈｍ－２;其中地上部分分别为８０１．４０和１５９．６８ｋｇ·ｈｍ－２,地下部分分别为２２８．５６和７１．６６ｋｇ·ｈｍ－２．该群落Ｃａ、Ｍｇ生物循环中,年吸收量分别为６３．１７和１８．６８ｋｇ·ｈｍ－２,年存留量分别为３１．７７和１１．４１ｋｇ·ｈｍ－２,年归还量分别为３１．４０和７．２７ｋｇ·ｈｍ－２;Ｃａ、Ｍｇ的富集率分别为１．６６和２．１４．     

青冈常绿阔叶林的碳素动态

报道了浙江建德青冈林碳素的含量、现存量、存留量、归还量、释放量以及在生态系统中的动态过程。结果表明：植物群落中碳素含量的变化幅度不大,一般在１０％以下。其中,叶片（器官比较）、乔木层（层次比较）和春夏季（季节比较）的含量稍高,根系、草本层、秋冬季的含量稍低。群落的碳素现存量为６６．１１３ｔ／ｈｍ２,主要集中在乔木层或常绿树种内;群落的碳素存留量为５．６９１ｔ／ｍ２·ａ;每年通过凋落物归还至地表的量为２．２９６ｔ／ｍ２·ａ;死地被物中又有０．９１１ｔ／ｈｍ２·ａ的碳素释放至大气库中。     

西双版纳季节雨林与橡胶多层林凋落物动态的比较研究

本语文对西双版纳季节雨林及橡胶多层林的凋落物量动态、各组分的季节变化规律、林地残留物现存量及其分解进行了研究,分析比较了两个种群落的凋落节律,结果显示,“双凋落峰”及“叶分解速率较枝分解更快”为两类群落的共有特征;森林凋落物量及凋落物分解速率则因群落类型而异,橡胶多层林年凋落物总量为９．８５±０．７８ｔ·ｈｍ＾－２·ａ＾－１,大于季节雨林的年凋落物总量８．４２±０．１６ｔ·ｈｍ＾－２·ａ＾－１。     

鹤山南亚热带草坡生态系统的生物量和生产力研究

以能量利用效率研究为中心,系统研究并分析了鹤山南亚热带草坡多年的光合作用与总第一性生产力、生物量与生物量增量、气候生产力模型和能量利用效率等能量学特征。草坡的总生物量为１１．３０ｔ·（ｈｍ）－２·ａ－１,其生物量增量为１．３９８ｔ·（ｈｍ）－２·ａ－１;草坡的总第一性生产力为４５．５４ｔ·（ｈｍ）－２·ａ－１,净第一性生产力为９．１０８ｔ·（ｈｍ）－２·ａ－１,用于净光合作用耗热１０５．５ＭＪ·ｍ－２·ａ－１,净光合耗热中又仅有２１．１ＭＪ·ｍ－２·ａ－１,用于净第一性生产力,净第一性生产力中又仅有３．２４ＭＪ·ｍ－２·ａ－１用于生物量增量;草坡生态系统的光能利用效率为０．０７％。草坡的能量利用效率是很低的     

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.