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41.
We conducted an extensive survey in search of hybrid baboons betweenPapio hamadryas andP. anubis along the Wabi-Shebeli river at the border of the Arusi and Bale Regions, Ethiopia. We made inquiries of villagers on the roadsides concerning the existence of baboon species. We also conducted direct observations at several sites. There are three routes which lead to the north bank of the Wabi-Shebeli river (Arusi Region), and we found hybrid baboons on the bank of the Wabi-Shebeli river in two routes among the three. We found hamadryas baboons in all of the three routes at the cliff areas. There are two routes which lead to the south bank of the Wabi-Shebeli river (Bale Region). We conducted a survey on one of the two. We found hamadryas baboons at the cliff areas of the route. We observed a population of gelada baboons along the cliff extending over 20 km along the north bank of the Wabi-Shebeli river (Arusi Region). This area is far to the south of the known distribution range of gelada baboons (Yalden et al., 1977). The gelada baboons of this area appeared to represent a different form (subspecies?) from those at Debre Sina (Showa Region) based on our observations in both areas. We reached the conclusion that the distributions of baboon species along the Wabi-Shebeli river may have been strongly affected by the intensive cultivation on the plateau of the highland. The distribution patterns of the three baboon species,P. anubis, P. hamadryas, andTheropithecus gelada, appeared to be influenced by their individual adaptabilities to the cliff environment. Hamadryas baboons were distributed continuously along the cliff and the narrow lowland of the Wabi-Shebeli river. Anubis baboons were distributed discontinuously on the cliffs, and their populations tended to be small and isolated. These anubis baboons were strongly hybridized with hamadryas baboons. 相似文献
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N Belay R Sparling B S Choi M Roberts J E Roberts L Daniels 《Biochimica et biophysica acta》1988,971(3):233-245
Two mesophilic methanogenic bacteria, Methanobacterium bryantii strain MOH and Methanospirillum hungatei strain GP1 were demonstrated, using several different experimental approaches, to fix dinitrogen. Evidence includes (1) growth with N2 as the sole nitrogen source; (2) incorporation of 15N2 into cellular material (both soluble amino acid pools and insoluble cell protein and other macromolecules) detected by 15N-NMR spectroscopy; (3) acetylene reduction to ethylene by the cells, and inhibition of this reaction by bromoethanesulfonic acid (BES), a methanogen inhibitor. High-resolution 15N-NMR analysis of ethanol extracts of these organisms and cross-polarization magic-angle sample spinning analysis of the solid debris from these extracts are compared to labeled material from Methanococcus thermolithotrophicus, a methanogen previously determined to fix dinitrogen. 相似文献
45.
Potential sites of bioactive gibberellin production during reproductive growth in Arabidopsis 总被引:2,自引:0,他引:2
Hu J Mitchum MG Barnaby N Ayele BT Ogawa M Nam E Lai WC Hanada A Alonso JM Ecker JR Swain SM Yamaguchi S Kamiya Y Sun TP 《The Plant cell》2008,20(2):320-336
Gibberellin 3-oxidase (GA3ox) catalyzes the final step in the synthesis of bioactive gibberellins (GAs). We examined the expression patterns of all four GA3ox genes in Arabidopsis thaliana by promoter-beta-glucuronidase gene fusions and by quantitative RT-PCR and defined their physiological roles by characterizing single, double, and triple mutants. In developing flowers, GA3ox genes are only expressed in stamen filaments, anthers, and flower receptacles. Mutant plants that lack both GA3ox1 and GA3ox3 functions displayed stamen and petal defects, indicating that these two genes are important for GA production in the flower. Our data suggest that de novo synthesis of active GAs is necessary for stamen development in early flowers and that bioactive GAs made in the stamens and/or flower receptacles are transported to petals to promote their growth. In developing siliques, GA3ox1 is mainly expressed in the replums, funiculi, and the silique receptacles, whereas the other GA3ox genes are only expressed in developing seeds. Active GAs appear to be transported from the seed endosperm to the surrounding maternal tissues where they promote growth. The immediate upregulation of GA3ox1 and GA3ox4 after anthesis suggests that pollination and/or fertilization is a prerequisite for de novo GA biosynthesis in fruit, which in turn promotes initial elongation of the silique. 相似文献
46.
Developmental information on the structure and composition of the cartilaginous and bony skull in the large African barb Labeobarbus (=Barbus) intermedius (Teleostei; Cyprinidae) is provided. Sequences of cartilages and bones appearance from a large series of cleared and Alizarin red- and Alcian blue-stained laboratory-reared specimens ranging from prehatching larvae to juvenile stages are described. Comparisons of cranial development are made among cyprinids: L. intermedius, Danio rerio, Barbus barbus, and Cyprinus carpio. 相似文献
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Robert C. Holman Ermias D. Belay Krista Y. Christensen Ryan A. Maddox Arialdi M. Minino Arianne M. Folkema Dana L. Haberling Teresa A. Hammett Kenneth D. Kochanek James J. Sejvar Lawrence B. Schonberger 《PloS one》2010,5(1)
Background
Prion diseases are a family of rare, progressive, neurodegenerative disorders that affect humans and animals. The most common form of human prion disease, Creutzfeldt-Jakob disease (CJD), occurs worldwide. Variant CJD (vCJD), a recently emerged human prion disease, is a zoonotic foodborne disorder that occurs almost exclusively in countries with outbreaks of bovine spongiform encephalopathy.This study describes the occurrence and epidemiology of CJD and vCJD in the United States.Methodology/Principal Findings
Analysis of CJD and vCJD deaths using death certificates of US residents for 1979–2006, and those identified through other surveillance mechanisms during 1996–2008. Since CJD is invariably fatal and illness duration is usually less than one year, the CJD incidence is estimated as the death rate. During 1979 through 2006, an estimated 6,917 deaths with CJD as a cause of death were reported in the United States, an annual average of approximately 247 deaths (range 172–304 deaths). The average annual age-adjusted incidence for CJD was 0.97 per 1,000,000 persons. Most (61.8%) of the CJD deaths occurred among persons ≥65 years of age for an average annual incidence of 4.8 per 1,000,000 persons in this population. Most deaths were among whites (94.6%); the age-adjusted incidence for whites was 2.7 times higher than that for blacks (1.04 and 0.40, respectively). Three patients who died since 2004 were reported with vCJD; epidemiologic evidence indicated that their infection was acquired outside of the United States.Conclusion/Significance
Surveillance continues to show an annual CJD incidence rate of about 1 case per 1,000,000 persons and marked differences in CJD rates by age and race in the United States. Ongoing surveillance remains important for monitoring the stability of the CJD incidence rates, and detecting occurrences of vCJD and possibly other novel prion diseases in the United States. 相似文献49.
Silvio Notari Francisco J. Moleres Stephen B. Hunter Ermias D. Belay Lawrence B. Schonberger Ignazio Cali Piero Parchi Wun-Ju Shieh Paul Brown Sherif Zaki Wen-Quan Zou Pierluigi Gambetti 《PloS one》2010,5(1)
Background
Variant Creutzfeldt–Jakob disease (vCJD) is a prion disease thought to be acquired by the consumption of prion-contaminated beef products. To date, over 200 cases have been identified around the world, but mainly in the United Kingdom. Three cases have been identified in the United States; however, these subjects were likely exposed to prion infection elsewhere. Here we report on the first of these subjects.Methodology/Principal Findings
Neuropathological and genetic examinations were carried out using standard procedures. We assessed the presence and characteristics of protease-resistant prion protein (PrPres) in brain and 23 other organs and tissues using immunoblots performed directly on total homogenate or following sodium phosphotungstate precipitation to increase PrPres detectability. The brain showed a lack of typical spongiform degeneration and had large plaques, likely stemming from the extensive neuronal loss caused by the long duration (32 months) of the disease. The PrPres found in the brain had the typical characteristics of the PrPres present in vCJD. In addition to the brain and other organs known to be prion positive in vCJD, such as the lymphoreticular system, pituitary and adrenal glands, and gastrointestinal tract, PrPres was also detected for the first time in the dura mater, liver, pancreas, kidney, ovary, uterus, and skin.Conclusions/Significance
Our results indicate that the number of organs affected in vCJD is greater than previously realized and further underscore the risk of iatrogenic transmission in vCJD. 相似文献50.
Stacy M. Holzbauer Aaron S. DeVries James J. Sejvar Christine H. Lees Jennifer Adjemian Jennifer H. McQuiston Carlota Medus Catherine A. Lexau Julie R. Harris Sergio E. Recuenco Ermias D. Belay James F. Howell Bryan F. Buss Mady Hornig John D. Gibbins Scott E. Brueck Kirk E. Smith Richard N. Danila W. Ian Lipkin Daniel H. Lachance P. James. B. Dyck Ruth Lynfield 《PloS one》2010,5(3)