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801.
Within the context of microorganism/host interactions, those which last over weeks are expected to be sensitive to more or less sustained and targeted immuno-intervention, such as delivery of cytokines known to operate as down-regulators of acute inflammatory processes. IL-10 has received growing attention as a potential tool in immunotherapy, due to its anti-inflammatory and immunosuppressive properties. Therefore, using two experimental models of long-term interactions between parasites and laboratory mice, we monitored some effects of the systemic delivery of an adenovirus (Ad) expressing EBV-derived IL-10 (vIL-10) designated Ad-vIL-10. We first monitored the vIL-10 serum level following intranasal, intraperitoneal, intramuscular and intravenous administration. The i. p. and i.v. delivery of Ad-vIL-10 allowed a high serum level of vIL-10 (= 100 ng/ml), the i.v. route leading to a more sustained expression (up to 3 weeks). As a first model of parasite/mouse interaction, Schistosoma mansoni/C57Bl/6 mouse was selected. Ad-vIL-10 delivery was performed 4 weeks after S. mansoni infection i.e. at the time of egg-laying, and several parameters were monitored: (i) number of adult worms in the mesenteric vein, (ii) number of eggs trapped in the liver and intestine, (iii) liver fibrosis, (iv) serum levels of egg-reactive antibody subclasses, (v) serum content of cytokines, and (vi) cytokine production in the supernatant of antigen-stimulated mesenteric lymph node cells. No apparent effect was observed, either on the different parasitological parameters or on fibrosis development at day 70 of infection. Surprisingly, a marked increase in both Th1 and Th2 type cytokines was observed in the sera of the Ad-vIL-10 injected animals, as well as in the supernatants of their Ag-stimulated mesenteric lymph node cells. Nevertheless, polarization of the humoral response towards a Th2 profile was demonstrated by an increase in the IgE level in the Ad-vIL-10-injected animals. As far as the second model is concerned, namely the Leishmania amazonensis /C57Bl6 mouse interactions, Ad-vIL-10 was delivered intravenously one day before subcutaneous injection of stationary promastigotes and footpad swelling was monitored over 110 days. Under these conditions, vIL-10 exhibited a biphasic effect, decreasing the lesion size at the early stages of infection, but leading to a more pronounced lesion size during the chronic phase. This observation suggests a deactivation of the macrophage host cells under the influence of vIL-10. The results are discussed in the context of immunotherapy and the paradoxical effects observed in immunointervention with vIL-10.  相似文献   
802.
Plants of four isolines of soyabean [Glycine max(L.) Merrill]‘Clark’, viz‘L71-920’ (maturity genecomplemente1e2e3 ), ‘L80-5914’ (E1e2e3), ‘Clark’(e1E2E3), and ‘L65-3366’ (E1E2E3), were grown inshort (12.25 h d - 1natural light) and long days (12.25 h d- 1natural light supplemented with 2.75 h d - 1low-irradianceartificial light) from first flowering to maturity in a polythenetunnel maintained at 30/24°C (day/night). Whereas therewere few differences among the isolines grown in short days,in long days the dominant alleles increased crop duration, biomassand seed yield substantially. Increases in biological and economicyield were not solely a consequence of longer crop duration:the dominant alleles also increased crop growth rate and radiationuse efficiency in long days (from 1.3 g MJ - 1total radiationine1e2e3 to 2.8 g MJ - 1inE1E2E3 ). Greater radiation use efficiencyresulted from a relatively longer leaf area duration, betterdistribution and orientation of a larger mass of leaves withinthe canopy, and smaller partitioning of assimilates to reproductivestructures. The work reveals the substantial effects of thethree lociE1 / e1, E2/ e2and E3/e3 on the response of plantgrowth, as well as development, to environment. Their relevanceto crop adaptation is discussed. Copyright 2000 Annals of BotanyCompany Glycine max(L.) Merrill, soyabean, maturity genes, flowering, phenology, growth, yield  相似文献   
803.
Two new species of Haptoglossa , one zoosporic, H. northumbrica , and one aplanosporic, H. polymorphs, , were isolated from samples of manure and horse dung in north-east England. The zoosporic H. northumbrica is morphologically similar to H. dickii but differs in having slightly smaller infection gun cells with a unique internal arrangement of cones in the apical missile chamber. The thallus of the aplanosporic H. polymorpha is similar to H. heteromorpha but produces three different types of aplanospore. The smaller cysts either develop into broad, arcuate gun cells or form curved adhesive cells that have a rounded base. These curved adhesive cells have very different internal ultrastructural organization. The large cysts develop into infection cells that are morphologically similar to the curved adhesive cells, but their internal structure has not yet been observed.  相似文献   
804.
We studied 654 healthy ten- to twelve-year-old children living in the Russian Far North (Taimyr peninsula) and in Siberia (town of Krasnoyarsk). The state of the body oxygenation and the systems responsible for oxygen delivery were studied according to the length of time living in the Russian Far North and season of the year. An examination of newcomer children revealed the following changes during the first year of living in the Russian Far North: an increased respiration rate and changes in its circadian rhythm; an increase in the heart rate, cardiac output, and cardiac index; an increase in the mean corpuscular volume in the red blood system; the activation of lipid peroxidation, and the changes in electrolyte balance of cells. The control mechanisms of oxygen transport system gradually stabilized during the ages of two to five years. In children living more than five years in the Russian Far North, the increased oxygen demand was met by the activation of cardiovascular and red blood systems aimed at more effective and adequate oxygen delivery to tissues.  相似文献   
805.
Biomass of bottom and near-bottom fishes in the eastern Sea of Okhotsk has been calculated using results of a bottom trawl survey performed in the summer 2010 through depths of 200?C1000 m. Obtained data are compared with the results of investigations performed in compatible water areas during the same season of 1989 and 1997. Biomass variability patterns of major species have been revealed for the period of more than two recent decades. The bathymetric and spatial distribution of major fish species has been revealed using the modern information. Species are listed whose commercial catches could be enlarged.  相似文献   
806.
807.
808.
Anthers of Vitis latifolia L. (wild grape) cultured on Nitsch and Nitsch medium supplemented with 20 μM 2,4-D and 9 μM BAP produced callus after 4–6 weeks. Subculture of callus onto Nitsch and Nitsch medium containing 10 μM NAA produced somatic embryos within 6 weeks. On growth regulator-free Nitsch and Nitsch basal medium somatic embryos converted to plantlets in 6–8 weeks. One gram of callus produced more than 400 somatic embryos with 13.7% being converted to complete plantlets, which were subsequently established in soil. Regenerated plants were found to have mixoploid populations of cells, 2n = 38 and n = 19. Received: 23 May 1998 / Revision received: 21 September 1998 / Accepted: 10 October 1998  相似文献   
809.
The distribution, antiquity and epidemiology of tuberculosis (TB) have previously been studied in osteoarchaeological material in the eastern part of Hungary, mainly on the Great Plain. The purpose of this study is to map the occurrence of skeletal TB in different centuries in the western part of Hungary, Transdanubia, and to present new cases we have found. Palaeopathological analysis was carried out using macroscopic observation supported by radiographic and molecular methods. A large human osteoarchaeological sample (n = 5684) from Transdanubian archaeological sites ranging from the 2nd to the 18th centuries served as a source of material. Spinal TB was observed in seven individuals (in three specimens with Pott's disease two of which also had cold abscess) and hip TB was assumed in one case. The results of DNA for Mycobacterium tuberculosis were positive in seven of the eight cases identified by paleopathology, and negative in the assumed case of hip TB. However, the molecular results are consistent with highly fragmented DNA, which limited further analysis. Based on the present study and previously published cases, osteotuberculosis was found in Transdanubia mainly during the 9th-13th centuries. However, there are no signs of TB in many other 9th-13th century sites, even in those that lie geographically close to those where osteotuberculous cases were found. This may be due to a true absence of TB caused by the different living conditions, way of life, or origin of these populations. An alternative explanation is that TB was present in some individuals with no typical paleopathology, but that death occurred before skeletal morphological features could develop.  相似文献   
810.
A novel biocatalytic reaction of transamidation of non-activated amides with amines is reported. Among 45 different lipolytic and proteolytic enzymes tested, only the lipase from Candida antarcticawas able to catalyze this reaction. The reaction proceeded with up to ca. 80% conversion in anhydrous methyl tert-butyl ether and worked with both N-substituted and unsubstituted amides. The biocatalytic transamidation is an equilibrium process and, therefore, higher conversions to the desired amide were achieved by using increased concentrations of the amine nucleophile.  相似文献   
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