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1.

Background  

Populations of the Oriental White-backed Vulture (Gyps bengalensis) have declined by over 95% within the past decade. This decline is largely due to incidental consumption of the non-steroidal anti-inflammatory veterinary pharmaceutical diclofenac, commonly used to treat domestic livestock. The conservation status of other Gyps vultures in southern Asia is also of immediate concern, given the lack of knowledge regarding status of their populations and the continuing existence of taxonomic uncertainties. In this study, we assess phylogenetic relationships for all recognized species and the majority of subspecies within the genus Gyps. The continuing veterinary use of diclofenac is an unknown but potential risk to related species with similar feeding habits to Gyps bengalensis. Therefore, an accurate assessment of the phylogenetic relationships among Gyps vultures should aid in their conservation by clarifying taxonomic uncertainties, and enabling inference of their respective relatedness to susceptible G. bengalensis.  相似文献   
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alpha 1-Proteinase inhibitor (alpha 1-PI), a member of the serine proteinase inhibitor superfamily, has a primary role in controlling neutrophil elastase activity within the mammalian circulation. Several studies have indicated that the reactive center region of alpha 1-PI, the amino acid sequence of which is critical to recognition of and binding to target proteinases, is highly divergent within and among species. This appears to be a consequence of accelerated rates of evolution that may have been driven by positive Darwinian selection. In order to examine this and other features of alpha 1-PI evolution in more detail, we have isolated and sequenced cDNAs representing alpha 1- PI mRNAs of the mouse species Mus saxicola and Mus minutoides and have compared these with a number of other mammalian alpha 1-PI mRNAs. Relative to other mammalian mRNAs, the extent of nonsynonymous substitution is generally high throughout the alpha 1-PI mRNA molecule, indicating greater overall rates of amino acid substitution. Within and among mouse species, the 5'-half of the mRNA, but not the 3'-half, has been homogenized by concerted evolution. Finally, the reactive center is under diversifying or positive Darwinian selection in murid rodents (rats, mice) and guinea pigs yet is under purifying selection in primates and artiodactyls. The significance of these findings to alpha 1-PI function and the possible selective forces driving evolution of serpins in general are discussed.   相似文献   
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Patterns of mitochondrial DNA (mtDNA) variation were examined in 133 mole-rats constituting all four chromosomal species (2n = 52, 2n = 54, 2n = 58, and 2n = 60) of the Spalax ehrenbergi superspecies in Israel, as well as the peripheral isolates of 2n = 60. In the main range of the complex, a total of 28 mtDNA haplotypes were found in 64 mole-rats, with most haplotypes being unique to either a single chromosomal species or population. mtDNA divergence increased from low to high diploid number in a north-to-south direction in Israel. Overall levels of mtDNA diversity were unexpectedly the highest in the 2n = 60, the youngest species of the complex. The mtDNA haplotypes can be separated into two major groups, 2n = 52-54 and 2n = 58-60, and a phylogenetic analysis for each group revealed evidence of a few haplotypes not sorted by diploid number. The overall patterns of mtDNA divergence seen within and among the four chromosomal species are consistent with the parapatric mode of speciation as suggested from previous studies of allozyme and DNA hybridization. In a separate data set the patterns of mtDNA variation were examined across the main geographic range and across peripheral semi-isolates and isolates of the 2n = 60 chromosomal species. Fifteen haplotypes were found in 69 mole-rats. High levels of mtDNA diversity characterized the main range, semi-isolated, and even some desert isolated populations. The peripheral isolates contain much mtDNA diversity, including novel haplotypes.   相似文献   
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Summary A mixture of 1-naphthylacetic acid and 6-benzylaminopurine was found to be an effective substitute for the rhizome apex of attached rhizomes, when the plants were not at anthesis. The same mixture was not effective, however, when the plants were at anthesis. The same growth-regulators applied to the apical end of detached multi-node rhizome fragments did not maintain correlative inhibition unless growth-regulators were simultaneously applied to the basal end. Various interactions between apical and basal applications are discussed with regard to their role as a parental factor in apical dominance.Abbreviations NAA 1-naphthyl acetic acid - BAP 6-benzylaminopurine - ABA abcisic acid - IAA indole-3-acetic acid  相似文献   
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Newer agents and procedures give urologists more options in treating patients who have urinary incontinence related to such etiologies as an ineffective sphincter, detrusor hypersensitivity, obstruction, or a combination of these. Abolition of the involuntary contractions characteristic of detrusor instability can be accomplished pharmacologically or surgically. First-line anticholinergic agents are tolterodine and oxybutynin XL, given orally. Alternatively, intravesical administration provides a high concentration of drug, such as capsaicin or resiniferatoxin, at the detrusor muscle level. However, this commits the patient to intermittent self-catheterization. Surgery is reserved for those who have failed prolonged trials of conservative therapies. For patients with intractable urge incontinence, urologists have the new technique of sacral nerve stimulation.  相似文献   
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Stress urinary incontinence (SUI) involves involuntary leakage of urine in response to abdominal pressure caused by activities such as sneezing and coughing. The condition affects millions of women worldwide, causing physical discomfort as well as social distress and even social isolation. Until recently, SUI was approached by clinicians as a purely anatomic problem requiring behavioral or surgical therapy. Over the past several years, extensive basic and clinical research in the field of neurourology has enhanced our understanding of the complex neural circuitry regulating normal function of the lower urinary tract. As a result, novel concepts have emerged regarding possible neurologic dysfunctions that might underlie the development of SUI, as well as potential novel strategies for pharmacologic therapy. This article reviews the normal neurophysiologic control of lower urinary tract function and considers potential pharmacologic approaches to correcting SUI.  相似文献   
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