重金属复合污染对土壤—植物系统的生态效应II.对作物,苜蓿,树…

研究Ｃｄ、Ｐｂ、Ｃｕ、Ｚｎ、Ａｓ５元素复合污染对农作物、苜蓿、树木吸收元素的影响,供试污染物浓度以接近国内外土壤环境标准值作为高剂量处理,结果表明,５种元素间存在交互作用,可提高作物对Ｃｄ、Ｐｂ、Ｚｎ吸收系数,籽实超出粮食卫生标准的超标率在低剂量处理时Ｃｄ为１６．６￣４２．８５％,高剂量时达１６．６￣７１．４２％。苜蓿茎叶中Ｃｄ、Ｐｂ含量超出饲料卫生标准,树叶中含量也有所增加,在中、酸性土壤上尤甚     

兔迷走复合区内微量注射TRH对奥迪氏括约肌肌电的影响及传出途径分析

目的和方法：本工作旨在研究免迷走复合区（ＤＶＣ）内ＴＲＨ对奥迪氏括约肌（ＳＯ）肌电的调节作用及外周途径。结果：（１）ＤＶＣ内注射ＴＲＨ（０．８ｎｍｏｌ,１μｌ）后,慢波电位（ＳＷ）频率不变,但锋电位频率（ＦＳＰＳＯ）及幅度（ＡＳＰＳＯ）、锋电位发生率（ＩＳＰ）明显增加．（２）ＤＶＣ内分别注射不同剂量ＴＲＨ（０．１３,０．２５,０．５０,０．８０,１．３０ｎｍｏｌ,１μｌ）后,各剂量ＴＲＨ均能引起ＦＳＰＳＯ增加。随注射剂量的增加,ＳＯ反应强度和持续时间均增加,呈现明显的剂量反应关系。（３）ＤＶＣ内注射ＴＲＨ兴奋ＦＳＰＳＯ的效应可被静脉注射阿托品（０．２ｍｇ／ｋｇ）或迷走神经切断完全阻断,但不能被静脉注射酚妥拉明（１．５ｍｇ／ｋｇ）、心得安（１．５ｍｇ／ｋｇ）或脊髓切断术所阻断。结论：ＤＶＣ内ＴＲＨ可能对ＳＯ肌电有重要的调节作用,这种作用是通过迷走神经及外周Ｍ受体介导。     

杨树落叶前后重金属元素内外迁移循环规律研究

供试元素在杨树各部位的含量和贮量为Ｚｎ＞Ｃｕ＞Ａｓ＞Ｐｂ＞Ｃｄ,并与环境中相应元素浓度呈正相关．落叶时元素的迁移主要发生在叶、枝、根和干之间,叶中８～４８％的Ａｓ、Ｚｎ迁移至主干的皮与材中,而Ｃｕ、Ｐｂ、Ｃｄ贮量均有增加,Ｚｎ、Ａｓ的内循环占总循环量的４０％,Ｃｄ、Ｐｂ、Ｃｕ表现为外循环,占总贮量的１７～２７％．同时分析了植物对土壤重金属污染的净化效率．     

株洲工业区土壤重金属污染与蚯蚓同工酶的研究

用聚丙烯朊胺凝胶圆盘电泳法对蚯蚓酯酶及过氧化物酶同工酶进行比较研究,结果表明,重金属在蚯蚓体内富集量随污染程度增加而上升,重污染区为中污染区的２．２７倍,为轻污染区的７．３０倍,重污染区Ｃｄ、Ｐｂ、Ａｓ在蚯蚓体内分别达到４７．３、３５．２、１６．３２μｇ．ｋｇ＾－１。其秩相关系数（ｒ５）〉０．６６－０．７７。蚯蚓酯酶同工酶酶带减少,酶活性降低,而其过氧化物酶酶带和酶活性有所增加。     

头端延髓腹外侧区血管加压素在刺激中脑dPAG区诱发防御性升压反应中的…

雄性Ｓｐｒａｇｕｅ－Ｄａｗｌｅｙ大鼠,用乌拉坦（７００ｍｇ／ｋｇ）和氯醛糖（３０ｍｇ／ｋｇ）腹腔麻醉。在双侧头端延髓腹外侧区（ｒＶＬＭ区）每侧微量注射血管加压素（ＡＶＰ）（１０ｐｍｏｌ／０．１μｌ）可引起平均动脉压（ＭＢＰ）升高,心率（ＨＲ）变化不明显,每侧微量注射ＡＶＰ的Ｖ１受体拮抗剂ｄ（ＣＨ２）５［Ｔｙｒ（Ｍｅ）＾２］ＡＶＰ（０．１ｎｍｏｌ／０．１μｌ）后ＭＢＰ和ＨＲ无明显变化。若预先在ｒＶＬ     

亲和层析纯化HepG_2细胞分泌的PAI－1

本文报道用抗ＰＡＩ－１单克隆抗体（ＭｃＡｂ）亲和层析建立了纯化ＰＡＩ－１的简便方法。经免疫亲和层析,ＳｅｐｈａｃｒｙｌＳ２００凝胶过滤,从ＨｅｐＧ２细胞培液中分离到糖基化和非糖基化两种形式的ＰＡＩ－１,回收率为８４％,ＰＡＩ－１比活性６．１×１０４ＩＵ／ｍｇ。糖基化ＰＡＩ－１分子量为５０ｋＤ,比活性５．８×１０４ＩＵ／ｍｇ。非糖基化ＰＡＩ－１分子量４３ｋＤ,占总ＰＡＩ－１３０％,仍具有ＰＡＩ－１活性。用ＣｏｎＡ－Ｓｅｐｈａｒｏｓｅ亲和层析进一步纯化得到ＳＤＳ－ＰＡＧＥ纯的糖基化ＰＡＩ－１。     

兔肝金属硫蛋白β结构域的制备和鉴定

制备一定量的Ｃｄ、Ｚｎ兔肝金属硫蛋白（ｍｅｔａｌｏｔｈｉｏｎｅｉｎ,ＭＴ）,然后脱掉其中的金属,获得不含金属的硫蛋白（ａｐｏＭＴ）．用一价金属ＣｕＣｌ或ＡｇＮＯ３以５．８１的金属蛋白摩尔比与ａｐｏＭＴ结合,将其β结构域用金属饱和,在３７℃,ｐＨ７．０下用枯草杆菌蛋白酶水解掉未结合金属的α结构域,获得Ｃｕ（Ⅰ）、Ａｇ（Ⅰ）结合的兔肝ＭＴ－Ｉ、ＭＴ－Ⅱ的β结构域．通过ＨＰＬＣ、羧甲基化后的ＳＤＳ－ＰＡＧＥ、氨基酸组成分析、金属定量、Ｎ末端分析和紫外扫描等鉴定,证明确实得到了Ｎ末端为Ｍｅｔ,分子量３０００左右,金属蛋白摩尔比为５～５．５１的ＭＴβ结构域,其氨基酸组成与理论值基本相符     

重金属复合污染对大豆生长的影响及其综合评价研究

通过正交试验设计研究了溶液培养条件下Ｃｄ、Ｐｈ、Ｃｕ、Ｚｎ、Ａｓ复合污染对大豆幼苗生长的影响．结果表明,复合污染条件下,各元素在根中的积累顺序为ＡＳ＞Ｐｂ＞Ｃｕ＞Ｃｄ＞Ｚｎ,茎叶中为Ｃｄ＞Ｃｕ＞Ｚｎ＞Ａｓ＞Ｐｈ,其交互作用类型决定于元素的投加浓度及其与共存元素的比例,而对其生长发育,ＡＳ和ＣＵ是主要的毒害元素,并指出相对离子强度是复合污染综合效应指示与控制的又一有效指标．     

用国产微孔玻璃珠初步纯化人u-PA

用国产微孔玻璃珠从ＣＤ－１工程细胞株培养上清中纯化ｕ－ＰＡ,摸索了微孔玻璃珠结合ｕ－ＰＡ的条件和洗脱方法,比较了硫酸铵线性梯度洗脱或２５％乙二醇洗脱ｕ－ＰＡ活性的结果,最后确定洗脱的条件为０．２５ｍｏｌ／ＬＴｒｉｓ、１～２ｍｏｌ／Ｌ（ＮＨ４）２ＳＯ４、ｐＨ９．３。经此一步纯化,ｕ－ＰＡ比活性达到１５３２９ＩＵ／ｍｇ,回收率７８％,还原条件下ＳＤＳ－ＰＡＧＥ分子量为５２×１０３的单链ｕ－ＰＡ占７４％。     

人胎肺细胞的条件化培养液中两种类型纤溶酶原活化物的分离

用正常人胎肺细胞体外培养,从其培养液中分离纤溶酶原活化物（ＰＡ）,通过ＣＭ－ＳｅｐｈａｄｅｘＣ－５０层析,硫酸铵沉淀和Ｆｉｂｒｉｎ－Ｓｅｐｈａｒｏｓｅ,Ｌｙｓｉｎｅ－Ｓｅｐｈａｒｏｓｅ亲和层析及ＳｅｐｈａｄｅｘＧ－５０凝胶过滤等步骤,从１０．５ｌ条件培养液中分离纯化得到两种类型的纤溶酶原活化物,ｔ－ＰＡ９０μｇ,ｕ－ＰＡ８００μｇ．在还原条件下ＳＤＳ－ＰＡＧＥ均显示单带,分子量ｔ－ＰＡ为７２ｋＤ,ｕ－ＰＡ为５４ｋＤ,纤溶比活分别为１５６０００ＩＵ／ｍｇ蛋白和１０６０００ＩＵ／ｍｇ蛋白．     

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     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.