马边大风顶自然保护区大熊猫能量摄入和食物资源能量估算

本文对凉山山系马边大风顶自然保护区大熊猫日能量摄入和食物资源能量进行了估算。结果表明,不同季节大熊猫的日能量摄入各异,春季为１５３７８ｋＪ,夏秋季为２７８５６．２ｋＪ,冬季为２０５２０２．６ｋＪ约高于日能量支出１４６５１－１６７４４ｋＪ,营养保险差较小,对环境的承受力较弱。另外,环境中每平方米大叶筇竹林能被大熊猫实际利用的能量约为１２３．５ｋＪ,约０．０６ｋｍ＾２大叶筇竹林能满足１只成年大熊猫全年     

小熊猫对食物的选择和觅食对策的初步研究

作者在四川马边大风顶自然保护区对小熊猫的食物选择和觅食对策进行了研究,结果表明小熊猫喜欢选择在坡度较大,林木郁闭度适中,竹子生长良好,竹子密度适中,离水源较近的杜鹃－大叶筇竹林中活动觅食,喜食大叶筇竹竹叶和竹笋,偶食白背玉山竹竹叶和竹笋,不食刺竹,并且对大叶筇竹竹龄和竹叶也有明显的选择,喜食１、２年生竹或刚萌生的幼嫩竹叶。环境每１ｍ＾２的大叶筇竹竹叶能提供２８５０、０９ＫＪ的能量,若按１％的利用率     

马占相思(Acacia mangium)的生长、固氮及叶状柄的营养成分

马占相思（Ａｃａｉｃａ ｍａｎｇｉｕｍ）在厦门地区生长良好,生长速度和地上部重复一均大于肯氏相思（Ａ．ｃｕｎｎｉｎｇｈａｍｉａ）和大叶相思（Ａ．ａｕｒｉｃｕｌａｅｆｏｒｍｉｓ）。４年生的马占相和大叶相思人工林年凋落物的干重分别为１１５ｇ ｍ＾２、６６５８．ｇ ｍ＾２。马占相思和肯氏相思根瘤氮酶活性均有明显的季节变化,８份〉１０月分〉５月份〉２月分,马占相思叶状柄营养丰富,含有较高的蛋白质和氨基酸,     

东北柴胡属细胞分类学研究Ⅰ．6种柴胡的核型分析

本文报道了国产６种柴胡的核型,发现在肇东五里木存在一种与日本产三岛柴胡Ｂ．ｆａｌｃａｔｕｍ具有相同核型特征的柴胡,暂称其五里木居群。柞柴胡Ｂ．ｋｏｍａｒｏｖｉａｎｕｍＬｉｎｃｚ．２ｎ＝８＝２ｍ＋６ｓｍ（２ＳＡＴ）．红柴胡Ｂｓｃｏｒｚｏｎｅｒｉｆｏｌｉｕ,Ｗｉｌｌｄ．２ｎ＝１２＝１０ｍ（２ＳＡＴ）＋２ｓｍ．北柴胡ＢｃｈｉｎｅｎｓｅＤＣ．２ｎ＝２４＝１４ｍ＋１０ｓｍ（２ＳＡＴ）．锥叶柴胡Ｂ．ｂｉｃａｕｌｅＨｅｌｍ２ｎ＝３２＝２０ｍ＋１２ｓｍ．大叶柴胡Ｂ．ｌｏｎｇｉｒａｄｉａｔｕｍＴｕｒｃｚ．２ｎ＝１２＝１０ｍ（２ＳＡＴ）＋２ｓｍ五里木居群２ｎ＝２６＝１６ｍ＋１０ｓｍ（２ＳＡＴ）文章最后根据核型特征分析了东北地区各种柴胡间的演化关系．     

冶勒自然保护区大熊猫和小熊猫种群能流分析

在冕宁县冶勒自然保护区设站,从各水平对同域分布、以同种竹子为食的大熊猫和小熊猫种群能流进行了研究。结果表明：通过大熊猫种群的能流（１．８６＊１０＾６ｋＪ／ｋｍ＾２．ｙｒ．）多于小熊猫种群（６．３４＊１０＾５ｋＪ／ｋｍ＾２．ｙｒ．）,前者大约是后者的２．９倍,说明大熊猫在群落中可能处于优势地位。虽然两种熊猫可利用食物资源占地面生物量的比例很大（大、小熊猫分别为１２．７９％和３．９２％）,但是其每年摄     

马边大风顶自然保护区大熊猫对竹类资源的选择利用

本文对凉山山系大熊猫对竹子资源选择利用进行了研究,发现对不同的竹类有不同程度的选择性。最喜食大叶筇竹和白背玉山竹,几乎不选择刺竹子;就大叶筇竹而言,喜食基径大于１０ｍｍ的幼竹竹茎,特别喜食基径大于１８ｍｍ的竹笋;就白背玉山竹而言,喜欢选择基径大于１２ｍｍ的竹茎和基径大于１６ｍｍ的竹笋,但对白背玉山竹的老嫩无明显选择。     

华蟹甲草属和蟹甲草属4种植物的核型

４种植物的染色体间期均为复杂型,前期染色体为中间型。华蟹甲草两居群的染色体数目及核型为２ｎ＝６０＝４４ｍ＋１６ｓｍ（４ＳＡＴ）和２ｎ＝６０＝４２ｍ＋１８ｓｍ（２ＳＡＴ）。蟹甲草属３种：阔柄蟹甲草为２ｎ＝６０＝５０ｍ＋１０ｓｍ;蛛毛蟹甲草为２ｎ＝６０＝５０ｍ＋１０ｓｍ（２ＳＡＴ）;三角叶蟹甲草两居群分别为２ｎ＝６０＝４４ｍ＋１６ｓｍ（２ＳＡＴ）和２ｎ＝６０＝４４ｍ＋１６ｓｍ。核型均为２Ａ型,尽管华蟹     

黄龙大熊猫对华西箭竹选择与利用的研究

１９９６年６～１０月,在黄龙寺自然保护区详细研究了大熊猫（Ａｉｌｕｒｏｐｏｄａ ｍｅｌａｎｏｌｅｕｃａ）对其主食竹之一－－华西箭竹的选择和利用情况,并与其他山系进行比较,结果表明：①黄龙大熊猫一年的食性选择可分为４个时期;②黄龙大熊猫喜食基径大于１０ｍｍ的竹笋和竹秆,而拒食基径小于６ｍｍ的竹笋及小于４ｍｍ的竹秆;③不同山系的大熊猫对竹类的选择既有差异又有共性;④大熊猫对华西箭竹竹茎的利用率为２２．     

世居及移居高原青少年最大有氧能力的特征

本文报道海拔３４１７ｍ和４２８０ｍ地区世居藏族和移居汉族青少年运动状态下心肺功能的对比研究。结果显示：３４１７ｍ和４２８０ｍ世居藏族的最大氧耗量、无氧阈值及最大心输出量都明显大于汉族,血氧饱和度（Ｓａｏ２）随运动负荷的增加而降低。海拔３４１７ｍ藏、汉族的△Ｓａｏ２分别为７．４６％和１０．０３％,４２８０ｍ处为８．５７％和１３．７５％,最大心率随海拔升高而下降。研究提示,藏族青少年有较高的最大有氧能力,反映了他们对低氧环境的适应优势。     

重离子束对酵母细胞的失活与突变

双倍体酵母细胞Ｄ７经单核能为１１．４ＭｅＶ／ｕ的Ａｎ和Ｕ离子辐照后,测定了细胞随剂量的存活率和突变率。获得细胞对Ａｕ和Ｕ离子的失活截面分别为２．５４μｍ２和１．９２μｍ２。在存活率为３７％的条件下,Ａｕ、Ｕ离子的ＲＢＥ分别为０．２８和０．１９。在突变实验中,研究了ＤＮＡ断链后的重组与倒位,它们对Ａｕ和Ｕ离子的截面为：８．３×１０－２μｍ２［σｍ－ｒｅｃ（Ａｕ）］,９．５×１０－５μｍ２［σｍ－ｒｅｃ（Ｕ）］和６．１×１０－４μｍ２［σｍ－ｒｅｖ（Ａｕ）］和３．８×１０－５μｍ２［σｍ－ｒｅｖ（Ｕ）］．最后,对所获结果进行了讨论。     

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.     

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     

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.     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various