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41.
本文选择两种溶剂体系,用两次单向薄层层析,从小麦抗寒与不抗寒品系天然橡胶胶乳分离提纯出6种单半乳糖和双半乳糖双甘油酯。并比较了它们的疏水侧链的脂肪酸组成。小麦糖脂疏水侧链脂肪酸的不饱和指数远大于天然胶乳糖脂。抗寒品系胶乳糖脂疏水侧链脂肪酸不饱和指数大于不抗寒品系。双半乳糖双甘油酯疏水侧链脂肪酸不饱和指数均大于其单半乳糖糖脂。 相似文献
42.
The 2',3'-dideoxyriboside of 2,6-diaminopurine selectively inhibits human immunodeficiency virus (HIV) replication in vitro 总被引:1,自引:0,他引:1
J Balzarini R Pauwels M Baba M J Robins R M Zou P Herdewijn E De Clercq 《Biochemical and biophysical research communications》1987,145(1):269-276
The 2',3'-dideoxyriboside of 2,6-diaminopurine(ddDAPR) is, like 2',3'-dideoxyadenosine (ddAdo), a potent and selective inhibitor of human immunodeficiency virus (HIV) in vitro. The ddDAPR compound inhibits HIV antigen expression and HIV-induced cytopathogenicity in MT4 cells at a 50% effective dose (ED50) of 2.5-3.6 microM, as compared to 3.1-6.4 microM for ddAdo. Both compounds are endowed with a high selectivity index: 112 for ddDAPR and 139 for ddAdo. The 2',3'-unsaturated derivatives of ddDAPR and ddAdo, i.e. ddeDAPR and ddeAdo, are considerably more cytotoxic and less effective against HIV than the parental compounds. Like ddAdo, ddDAPR is only weakly inhibitory to the proliferation and DNA and RNA synthesis of a series of human B-lymphoblast, T-lymphoblast and T-lymphocyte cell lines. In contrast to ddAdo, which is rapidly deaminated by beef intestine adenosine deaminase at an initial velocity (Vi) of 145 mumol/mg protein/min, ddDAPR and ddeDAPR are poor substrates for the enzyme (Vi: 8 and 0.7 mumol/mg protein/min, respectively), which further contributes to the potential of ddDAPR as a chemotherapeutic agent against AIDS. 相似文献
43.
44.
光质对一品红叶离体培养中形态发生及生化变化的影响 总被引:3,自引:0,他引:3
本文讨论了将光质应用于一品红(Euphorbia pulcherrima)大规模细胞繁殖及形态发生调控的可行性,并测定了一些形态及生化指标作为这种调控的参数。 以一品红试管苗的叶片作为外植体,置于MS培养基中并分别培养于白(W)、红(R)、黄(Y)、蓝(B)、绿(G)色光及黑暗(D)下,一个月后进行测定。蓝光和黄光明显促进出苗。而愈伤组织形成的情况则正相反,红光利于愈伤组织的形成,黄光效果最差。过氧化物酶、过氧化氢酶活力及蛋白质、RNA、碳水化合物的含量与愈伤组织形成有较为一致的关系,但与分化不直接相关。 实验中还测定了叶绿素a、叶绿素b及类胡萝卜素的含量。白光与蓝光均能促进叶绿素及类胡萝卜素的合成,但蓝光中chl b/chl a的比率较高。此外,本文尚涉及暗处理中的晶质化现象(vitrification)及其成因。 相似文献
45.
The kinematics of an area-conserving tank-treading disk-shaped red blood cell membrane is studied using the stream function
method suggested by Secomb and Skalak (Q. Jl Mech. appl. Math.
35, Pt 2, 233–247, 1982). Two simple area-conserving velocity fields are superimposed to satisfy the continuity condition at
the curved edges of the disk. A differential equation for the trajectory of any material point of the membrane is derived.
The requirement of synchrony of the cycle for all membrane points leads to an integral equation which determines a magnitude
function. An approximate solution is made possible by assuming small trajectory deflections. 相似文献
46.
Yuzuru Mikami Sen Feng Yu Katsukiyo Yazawa Kazutaka Fukushima Akio Maeda Jun Uno Kiyoshi Terao Naoki Saito Akinori Kubo Ken -ichiro Suzuki 《Mycopathologia》1990,112(2):113-118
During our studies on toxic substances from clinically isolated Nocarida, a new isolate identified as Nocardia otitidiscaviarum from cutaneous nocardiosis was found to produce a toxic substance called HS-6 that had strong in vitro as well as in vivo toxicity. The mouse intraperitoneal LD50 value was 1.25 mg/kg and the ED50 value for L1210 cultured cells was 0.3 ng/ml. The structure of HS-6 was determined and found to belong to the 16-membered macrocyclic group with a molecular formula of C43H68O12. HS-6 also showed activity against pathogenic fungi such as Cryptococcus neoformans. 相似文献
47.
传入C纤维的兴奋在中电针“足三里”激活中缝大核中的作用 总被引:6,自引:0,他引:6
The purpose of the present work is to study whether the analgesia of "Zusanli" EA was mainly produced by its noxious effect. The antidromic C waves on N. peroneus communis innervating the area of "Zusanli" point were recorded. When "Zusanli" point was stimulated by trains of stimuli, the amplitude of the antidromic C wave was obviously decreased due to collision with the orthodromic stimulation. It was suggested that EA of "Zusanli" could excite some C fibers. It was observed that when the stimulation intensity reached the threshold of C fiber, the NRM neurons were obviously activated, and when it reached or exceeded the intensity for producing the maximal C wave, the NRM neurons were highly activated. Therefore, EA analgesia is probably produced mainly by its noxious stimulus component, especially carried by C fibers, via a negative feedback mechanism in modulating pain. 相似文献
48.
Protection of mice against Sendai virus pneumonia by non-neutralizing anti-F monoclonal antibodies 总被引:1,自引:0,他引:1
Y Mochizuki T de Ming T Hayashi M Itoh H Hotta M Homma 《Microbiology and immunology》1990,34(2):171-183
Nine monoclonal antibodies (MAbs) directed to F protein of Sendai virus were obtained and characterized for their protective ability against Sendai virus infection in mice. None of the MAbs showed hemagglutination-inhibition (HI), hemolysis-inhibition (HLI), or neutralization (NT) activities in vitro when assayed by standard methods. Some of the MAbs, however, showed complement-requiring NT (C-NT) and complement-requiring hemolysis (C-HL) activities when assayed in the presence of complement. Passive immunization experiments revealed that the MAbs with higher C-NT and C-HL activities showed protective activity against Sendai virus pneumonia in mice, and that some MAbs with IgG1 isotype having neither C-NT nor C-HL activity also showed the protective activity. Digestion of the MAbs with pepsin which split immunoglobulin molecules into F(ab')2 and Fc fragments greatly suppressed the protective activity. These results suggest that not only complement-mediated immunological responses such as immune virolysis but also antibody-dependent cellular cytotoxicity (ADCC) and/or immune phagocytosis, in which complement system is not necessarily involved, play an important role in the protection of mice from Sendai virus infection. 相似文献
49.
50.