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Women of reproductive age who use and abuse psychoactive drugs and alcohol present a special challenge to primary care physicians. There are compelling medical reasons for identifying and intervening with pregnant women who are addicted or have alcoholism. The teratogenicity of all drugs of abuse and alcohol, the risk of infection with the acquired immunodeficiency syndrome (AIDS), and the potential for full recovery of a pregnant woman from addiction are some of the reasons that identification and intervention in the problem are indicated. Whether encountered in the clinic setting or in private practice, chemically dependent pregnant or postpartum women are usually responsive to appropriate physician interventions that include a detailed and caring confrontation- and advocacy-oriented support. Complex legal and ethical issues surround perinatal addiction including the role of toxicologic screening, reports to child welfare services, issues in noncompliance, and interdisciplinary case management.  相似文献   

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The genetics of retinoblastoma, revisited.   总被引:13,自引:7,他引:6       下载免费PDF全文
Our epidemiological and genetic analyses of sporadic and familial retinoblastoma indicate that an X-chromosome-linked gene is involved in the genesis of a significant fraction of new bilateral cases of the disease. The activity of this gene results in sex-ratio distortion in favor of males among patients with bilateral sporadic disease. Among the offspring of these males, both sex-ratio distortion in favor of males and transmission-ratio distortion in favor of affecteds are observed. We propose that these phenomena are due to the inability of these males to erase the genome imprint established on the half of the genome inherited from their mothers.  相似文献   

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In the present study SDS polyacrylamide gel electrophoresis was used to reinvestigate the conditions under which b-TSH dissociates into its constituent subunits. The effects of SDS, itself, urea, acid pH and temperature were assessed by the decrease in the amount of undissociated TSH and the increase in the dissociated components as revealed by SDS gel electrophoresis. In SDS alone 25--30% dissociation occurred. Pre-treatment with increasing concentrations of urea up to 7.1 M increased the degree of dissociation to 70% after h at room temperature. Maximum dissociation was achieved by treatment at pH 2.5 and 37 degree C for 1 h. In 1 M propionic acid approximately 10% of the TSH was still undissociated after 18 h at 25 degree C.  相似文献   

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The Florey Lecture, 1992. The secretion of proteins by cells.   总被引:2,自引:0,他引:2  
In eukaryotic cells, protein secretion provides a complex organizational problem. Secretory proteins are first transported, in an unfolded state, across the membrane of the endoplasmic reticulum (ER), and are then carried in small vesicles to the Golgi apparatus and finally to the cell membrane. The ER contains soluble proteins which catalyse the folding of newly synthesized polypeptides. These proteins are sorted from secretory proteins in the Golgi complex: they carry a sorting signal (the tetrapeptide KDEL or a related sequence) that allows them to be selectively retrieved and returned to the ER. This retrieval process also appears to be used by some bacterial toxins to aid their invasion of the cell: these toxins contain KDEL-like sequences and may, in effect, follow the secretory pathway in reverse. The membrane-bound receptor responsible for sorting luminal ER proteins has been identified in yeast by genetic means, and related receptors are found in mammalian cells. Unexpectedly, this receptor has a second role: in yeast it is required to maintain the normal size and function of the Golgi apparatus. By helping to maintain the composition of both ER and Golgi compartments, the KDEL receptor has an important role in the organization of the secretory pathway.  相似文献   

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The lands including Cave Spring and most of northwest Georgia were held by the Cherokee until Cherokee removal in 1838. In 2010, a two-story pine structure that was encased inside the Green Hotel in downtown Cave Spring, Georgia, was revealed during renovation. Local Cave Spring historians insist the log structure was built by Avery Vann in 1810, making it a Cherokee structure. However, the Gold Lottery maps of 1832 show no structure on lot 871, which today contains the Green Hotel. A construction date also cannot be verified by historical documents, maps, or artifacts discovered around the Green Hotel. The purpose of this research was to determine the construction date of the Green Hotel log structure. Archaeological dating of the window glass thickness of the hotel gave dates of 1810 or 1823. However, the dendroarchaeological dating of the wood indicates cutting dates during the late spring/early summer of 1839. This would indicate that the log structure inside the Green Hotel was not built by Avery Vann or any Cherokee, but by later Euro-American settlers.  相似文献   

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Infrared and Raman spectra are presented for salt solutions in N-methyl formamide and N,N'-dimethylformamide. Viscosities are reported for many of these solutions. Spectroscopic and viscosity data are also given for amide-salt solutions containing water. The three-component systems exhibit a hydrogen-bonding strength of water proton greater than amide proton, and an acceptor strength of Cl- greater than amide carbonyl oxygen greater than water oxygen. The salt cation is deduced by means of viscosity measurements to interact strongly with the amide carbonyl oxygen, even in the presence of appreciable quantities of water. Association of amides by hydrogen bonding through halide ions is also indicated.  相似文献   

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The 5-nitroimidazoles tinidazole (Fasigyn), ipronidazole (Ro-7-1554), panidazole and ornidazole (Tiberal, Ro-7-0207) in concentrations of 0.02--1 mM per liter increased the mutation frequency of Klebsiella pneumoniae. Escherichia coli K12 and Citrobacter freundii to streptomycin resistance, including streptomycin dependence, in Luria and Delbrück's fluctuation test. At low concentration (0.1 mM), the increase of the mutation frequency caused by each compound was nearly the same, i.e. 3--4 times the spontaneous mutation frequency. At higher concentrations, considerable differences between the mutagenic activities of the compounds occurred.  相似文献   

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