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991.
Antioxidant intake may be linked to a reduction of the chronic low-grade inflammatory state related to obesity and several accompanying disorders such as insulin resistance, cardiovascular diseases, and metabolic syndrome. So, the aim of this study was to evaluate the potential associations between nail trace elements and several indicators in healthy young adults, emphasizing on the putative effect of antioxidant trace element intake on inflammation-related marker concentrations. This study enrolled 149 healthy young adults, whose anthropometrical and blood pressure values as well as lifestyle features were analyzed. Fasting blood samples were collected for the biochemical and inflammation-related measurements (C-reactive protein, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, IL-18, and homocysteine). Nail samples were collected for the analysis of selenium, zinc, and copper concentrations. Our results showed that nail selenium was negatively associated with IL-18; nail zinc concentrations were inversely related to circulating IL-6, IL-18, and TNF-α, whereas nail copper (Cu) and Cu/selenium values were negatively correlated with homocysteine levels and the Cu/zinc ratio was unaffected. In conclusion, nail content on some trace elements related to antioxidant defense mechanisms seems to be associated with several inflammation-related markers linked to chronic diseases in apparently healthy young adults, which is of interest to understand the role of antioxidant intake.  相似文献   
992.
Scientific productivity of middle income countries correlates stronger with present and future wealth than indices reflecting its financial, social, economic or technological sophistication. We identify the contribution of the relative productivity of different scientific disciplines in predicting the future economic growth of a nation. Results show that rich and poor countries differ in the relative proportion of their scientific output in the different disciplines: countries with higher relative productivity in basic sciences such as physics and chemistry had the highest economic growth in the following five years compared to countries with a higher relative productivity in applied sciences such as medicine and pharmacy. Results suggest that the economies of middle income countries that focus their academic efforts in selected areas of applied knowledge grow slower than countries which invest in general basic sciences.  相似文献   
993.
Early experience is known to be important in the development of mating behaviour. The behavioural and chemical stimuli obtained by observing adults interacting are thought to operate as template by which young acquire the ability to sexually display when appropriate. But, while the importance of early social interactions for the development of mating behaviour is well accepted, how social deprivation at different onto‐genetic phases contributes for this effect is poorly understood. Here, we address this gap by asking how social deprivation at different ontogenetic phases (before or after 6 wk) mediates male mating behaviour in the Trinidadian guppy. We show that in the absence of early social interaction, the latency of mating behaviour is briefly delayed, but that all individuals were able to sexually display in <30 min. Interestingly, regardless of the timing of social deprivation, mating behaviour starts sooner under female‐biased sex ratios environments that than under a male‐biased sex ratio, suggesting that male sexual behaviour is driven by female cues. The short‐lived effects of social deprivation on mating behaviour reflect the extraordinary innate plasticity of guppies, which is likely to contribute to their success as invasive species.  相似文献   
994.
It has been demonstrated that the exposure of biological systems to magnetic fields (MFs) can produce several beneficial effects: tissue recovery in chronic wounds, re‐establishment of blood circulation after tissue ischemia or in necrotic tissues, improvement after epileptic episodes, angiogenesis, etc. In the current study, the effects of extremely low frequency (ELF) MF on the capillaries of some circumventricular organs (CVOs) are demonstrated; a vasodilator effect is reported as well as an increase in their permeability to non‐liposoluble substances. For this study, 96 Wistar male rats (250 g body mass) were used and divided into three groups of 32 rats each: a control group (no treatment); a sham ELF‐MF group; and an experimental group subjected to ELF‐MF (120 Hz harmonic waves and 0.66 mT, root mean square) by the use of Helmholtz coils. All animals were administered colloidal carbon (CC) intravenously to study, through optical and transmission electron microscopy, the capillary permeability in CVOs and the blood–brain barrier (BBB) in brain areas. An increase in capillary permeability to CC was detected in the ELF‐MF‐exposed group as well as a significant increase in vascular area (capillary vasodilation); none of these effects were observed in individuals of the control and sham ELF‐MF groups. It is important to investigate the mechanisms involved in the phenomena reported here in order to explain the effects of ELF‐MF on brain vasculature. Bioelectromagnetics 34:145–155, 2013. © 2012 Wiley Periodicals, Inc.  相似文献   
995.
Obesity is a multifactorial, chronic, inflammatory disease that involves different processes, such as adipose tissue hypoxia. The aim of the current study was to characterize the effects of conditioned medium (CM) from lipopolysaccharide (LPS)-activated macrophages on the regulation of hypoxia-inducible factor 1α (HIF-1α)-related genes in murine adipocytes. For the in vitro analyses, 3T3-L1 murine adipocytes (9 days postdifferentiation) were incubated either in CM (25% medium of RAW 264.7 murine macrophages with 24 hr 500 ng/ml LPS), LPS at 500 ng/ml, or hypoxia (Hx; 1% O2, 94% N2, 5% CO2) for 24 hr. For the in vivo experiments, mice were fed a high-fat diet. Both epididymal white adipose tissue (eWAT) and adipocytes in CM showed upregulation of Glut1, Mcp1, Il10, Tnf, and Il1b. The secretion of IL-6, TNF-α, and MCP-1 was also increased in CM-treated adipocytes. Moreover, increased levels of HIF-1α subunit and nuclear factor kappa B p65 were found after CM treatment, linking Hx, and inflammation. HIF-1α directly bound vascular endothelial growth factor A (Vegfa) and uncoupling protein 2 (Ucp2) genes, up- and downregulating its expression, respectively. Furthermore, the oxygen consumption rate was 30% lower in CM. The siRNA knockdown of mammalian target of rapamycin (Mtor) reversed the induction of HIF-1α found in CM. The macrophage infiltration simulated through CM seems to be a similar environment to an abnormally enlarged eWAT. We have evidenced that HIF-1α plays a regulatory role in the expression of Vegfa and Ucp2 in CM. Finally, the inhibition of the mTOR pathway prevented the HIF-1α activation induced by CM. The involvement of HIF-1α under proinflammatory conditions provides insight into the origins of Hx in obesity.  相似文献   
996.
997.
Aim To identify the dominant spatial patterns of Fagus sylvatica radial growth in the Eastern Alps, and to understand their relationships to climate variation and bioclimatic gradients. Location Fourteen beech stands in the Eastern Alps, growing between 200 and 1500 m a.s.l. in Italy, Slovenia and Austria. Methods At each site, trees were sampled using increment borers or by taking discs from felled trees. Cores and discs were processed by measuring and crossdating ring width. Ring width series were standardized, averaged, and prewhitened to obtain site chronologies. Hierarchical Cluster Analysis (HCA) and Principal Components Analysis of prewhitened site chronologies were used to identify spatial and altitudinal growth patterns, related to the bioclimatic position of each stand. Bootstrap correlation and response functions were computed between monthly climatic variables and either principal component scores or composite chronologies from stands associated by HCA. The stability of dendroclimatic signals was analyzed by moving correlation functions (MCF). Correlation analysis (teleconnections) based on a data base of 37 Italian and Slovenian beech tree‐ring chronologies revealed the spatial extent of principal component scores. Results Sampled trees were 200–400 years old, representing the oldest beech trees that have been crossdated for the Alps to date. Maximum age was directly related to altitude and to the presence of historical forms of conservation. Tree‐ring parameters varied according to geographic patterns and the age of sampled trees. Stands were bioclimatically organized according to their location, and with reference to their elevation and distance from the Adriatic Sea. A direct response to winter temperature was found at all elevations. The altitudinal gradient ranged from low‐elevation stands, characterized by a Mediterranean‐type, late spring–summer drought signal, to mountain and high‐elevation stands, characterized by a direct response to growing season temperature plus an inverse response to the previous year’s July temperature. The mountain and high‐elevation signal was evident in Austria, the Central Alps and Slovenia, while the low‐elevation signal was confined to mountains adjacent to the Adriatic Sea. MCF revealed trends in the response to climatic factors affecting tree‐ring formation in mountain and high‐mountain stands linked to climatic warming. Main conclusions Dendroclimatic networks can be used for bioclimatic studies of tree populations. A biogeographical separation emerged between the Alps and the Apennines at the upper elevations, while different degrees of mediterraneity distinguished sites at lower elevations. This information will be useful in assessing any future climate‐related bioclimatic shifts, especially for forests at ecotones and along altitudinal gradients.  相似文献   
998.
999.
A Bacillus thuringiensis respiratory mutant (AB1 strain) that shows premature sporulation and insecticidal crystal protein (ICP) production was isolated. The mutant strain harbours the cryIC and cryID insecticidal genes and could be important for the production of ICP highly toxic to Spodoptera sp. The mutant was selected by its increased capacity to oxidize. N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD). In this strain, cytochrome aa 3 expression is not repressed during the sporulation phase, in contrast with the wild-type strain. The growth, spore production, dissolved O2, O2 consumption, CO2 evolution rate and ICP production were recorded as a function of time. The AB1 mutant strain has a similar growth yield to the wild-type strain, but begins sporulation at least 4 h earlier. The AB1 strain consumes 74.5% more O2 than the wild-type strain, during the fermentation process. The mutation on strain AB1 has an important positive effect on ICP production. This procedure shows that ICP production could be increased during fermentation by increasing the respiration capacity of Bacillus thuringiensis. Correspondence to: A. Bravo  相似文献   
1000.
The effect of different doses of estradiol-17β (E2) on the netabolic pregnenolone to progesterone pathway in fragments of human term placenta incubated in vitro was studied. Doses considered as being physiological of 0.09 and 0.9 μM had a stimulatory effect on the conversion (p < 0.008 to 0.0l6). However, a supraphysiological dose of 45 μM showed an inhibitory activity related to the maximal stimulation (p < 0.03). A dose of 0.9 μM E2 favoured the accumulation of (3H)-progesterone in the tissue (p < 0.05). These results suggest that E2 may regulate the synthesis of progesterone in human term placenta.  相似文献   
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