Gonadotroph-specific expression of metallothionein fusion genes in pituitaries of transgenic mice   总被引：4，自引：0，他引：4  

M J Low  R M Lechan  R E Hammer  R L Brinster  J F Habener  G Mandel  R H Goodman 《Science (New York, N.Y.)》1986,231(4741):1002-1004

Transgenic mice expressing a metallothionein-somatostatin fusion gene contain high concentrations of somatostatin in the anterior pituitary gland, a tissue that does not normally produce somatostatin. Immunoreactive somatostatin within the anterior pituitaries was found exclusively within gonadotrophs. Similarly, a metallothionein-human growth-hormone fusion gene was also expressed selectively in gonadotrophs. It is proposed that sequences common to the two fusion genes are responsible for the gonadotroph-specific expression.  相似文献   

持续、低剂量金霉素对肉仔鸡免疫机能的抑制作用研究   总被引：14，自引：0，他引：14  

佟建明  张日俊等 《中国农业科学》2001,34(2):200-204

270只Abore Acre商品代肉用公鸡随机分成3组，金霉素在饲料中添加水平分别为0、50只和150mg/kg，研究饲用金霉素对肉仔鸡法氏囊、脾脏和胸腺等免疫器官发育、以及免疫反应的影响。结果表明50mg/kg的金霉素对肉仔鸡脾脏和21日龄的胸腺无明显抑制作用，对T、B淋巴细胞转化率也无明显抑制作用（P＜0.05），而且显著促进法氏囊的萎缩（P＜0.05）。金霉素对T淋巴细胞转化率有明显的直接抑制作用；50mg/kg和150mg/kg的金素对BAS特异性抗体的产生均有显著的抑制作用（P＜0.01）。研究结果表明，持续、低剂量和金霉素对肉 鸡免疫器官发育和免疫应答具有显著的抑制作用，抑制作用随剂量增加而加强，150mg/kg的金霉素对肉仔鸡具有显著促生长作用。  相似文献   

Quantum-confined stark effect in single CdSe nanocrystallite quantum dots     

SA Empedocles  MG Bawendi 《Science (New York, N.Y.)》1997,278(5346):2114-2117

The quantum-confined Stark effect in single cadmium selenide (CdSe) nanocrystallite quantum dots was studied. The electric field dependence of the single-dot spectrum is characterized by a highly polarizable excited state ( approximately 10(5) cubic angstroms, compared to typical molecular values of order 10 to 100 cubic angstroms), in the presence of randomly oriented local electric fields that change over time. These local fields result in spontaneous spectral diffusion and contribute to ensemble inhomogeneous broadening. Stark shifts of the lowest excited state more than two orders of magnitude larger than the linewidth were observed, suggesting the potential use of these dots in electro-optic modulation devices.  相似文献   

Immunogenicity of glucagon: determinants responsible for antibody binding and lymphocyte stimulation   总被引：4，自引：0，他引：4  

G Senyk  D Nitecki  J W Goodman 《Science (New York, N.Y.)》1971,171(969):407-408

Bovine glucagon, a polypeptide of 29 amino acids, is immunogenic in rabbits and guinea pigs. The antigenic determinants of glucagon were investigated with isolated tryptic peptides of the hormone. Antibodies from virtually all of more than a dozen animals tested had specificity primarily for the aminoterminal heptadecapeptide. However, only intact glucagon and its carboxy-terminal dodecapeptide stimulated spleen or lymph node cells to synthesize DNA. It thus appears that glucagon was cleaved along functional lines into two parts, one of which contained the major antigenic determinant for serum antibody and the other of which was "recognized" by antigen-reactive cells.  相似文献   

Eppendorf essay winner. Deconstructing C. elegans sensory mechanotransduction     

Goodman MB 《Science (New York, N.Y.)》2004,306(5695):427-428

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Coherin: a new peptide of the bovine neurohypophysis with activity on gastrointestinal motility   总被引：1，自引：0，他引：1  

I Goodman  R B Hiatt 《Science (New York, N.Y.)》1972,178(59):419-421

A factor with potent activity in the regulation of mammalian gastrointestinal motor function has been isolated from the bovine posterior pituitary gland by a process allowing minimal dissociation of neurophysin-bound complexes and the separation of free unbound peptides. This substance alters the frequency, amplitude, rhythm, and duration of peristaltic contraction.  相似文献   

Federal land releases     

Goodman GL 《Science (New York, N.Y.)》1971,172(3988):1085

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Standardized Pain Stimulation as Controlled Stress in Physiological Studies of Psychoneurosis     

Malmo RB  Shagass C  Davis JF  Cleghorn RA  Graham BF  Goodman AJ 《Science (New York, N.Y.)》1948,108(2810):509-511

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基于EDA技术的自动立木整枝机无线遥控接收系统   总被引：1，自引：0，他引：1  

张俊梅  李文彬  撒潮  王德明 《北京林业大学学报》2007,29(4):19-21

在分析自动立木整枝机工作过程和控制要求的基础上,该文详细阐述了自动立木整枝机无线遥控接收系统的组成及工作原理,进而采用电子设计自动化(EDA)技术设计了自动立木整枝机无线遥控接收系统的数字控制逻辑.通过优化CPLD内部逻辑电路,有效消除了逻辑竞争冒险.仿真结果表明,该系统控制可靠性较高,能有效提高自动立木整枝机的功能安全性.   相似文献   

Tumor DNA structure in plant cells transformed by A. tumefaciens   总被引：25，自引：0，他引：25  

P Zambryski  M Holsters  K Kruger  A Depicker  J Schell  M Van Montagu  H M Goodman 《Science (New York, N.Y.)》1980,209(4463):1385-1391

Crown gall tumors are induced in plants by infection with the soil bacterium Agrobacterium tumefaciens. Because the tumor induction involves transfer of a portion of the tumor-inducing (Ti) plasmid DNA from the bacterium to the plant cells, this system is of interest for the study of genetic exchange as well as tumor induction. The boundaries of the transferred DNA (T-DNA) have been cloned from transformed plant cells of tobacco. Detailed mapping with restriction enzymes and nucleotide sequence analysis of two independent clones were used to study the molecular structure of the ends of the T-DNA. One clone contains the two ends of the T-DNA joined together; the other contains one end of the T-DNA joined to repetitive plant DNA sequences. These studies provide direct evidence that the T-DNA can be integrated into the plant genome. In addition, the data suggest that in the plant, T-DNA can be tandemly repeated. Sequence analysis of the junction of crown gall clone 1 reveals several direct repeats as well as an inverted repeat; these structures may be involved in the transfer of the DNA from Agrobacterium to plant cells.  相似文献