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2.

Background  

Lung function is a strong predictor of cardiovascular and all-cause mortality. Previous studies suggest that alcohol exposure may be linked to impaired pulmonary function through oxidant-antioxidant mechanisms. Alcohol may be an important source of oxidants; however, wine contains several antioxidants. In this study we analyzed the relation of beverage specific alcohol intake with forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) in a random sample of 1555 residents of Western New York, USA.  相似文献   
3.
Shackleton  Charlie 《Plant Ecology》2002,158(1):65-76
Inter- and intra-specific competition has long been regarded as asignificant determinant of the structure and function of woody plantcommunitiesin African savannas. The most widely used approach to detect the presence orabsence of competition has been the use of nearest-neighbour methods. Althoughseveral studies have been published reporting the presence of competition inAcacia dominated communities, less than 20 plots have beensampled across all these studies. Results from broad-leaved communities arevariable, and also based on a small sample number. Consequently, this studysought to assess the prevalence of competition from a large number of savannasites (45), and to identify abiotic and biotic factors characterising siteswithcompetition relative to those without. Using the nearest-neighbour method onlyfour sites (9.3%) indicated the presence of inter-specific competition; twowereAcacia dominated communities (18.2% ofAcacia sites) and two were broad-leaved communities(7.7%).These four sites had a significantly higher mean annual rainfall and fewerwoodyspecies than sites without inter-specific competition. There were alsosignificant relationships between the inter-specific competition index and thedominance index and the number of species at a site. In terms of intra-specificcompetition only ten of the 31 sites tested revealed a significant correlationbetween nearest-neighbour distance and summed canopy volume of the twoneighbours. Seven were for Acacia species (55.6% of theAcacia species comparisons) and three were forbroad-leavedspecies (21.4% of the broad-leaved species comparisons). Sites lacking evidenceof intra-specific competition were at a significantly lower slope position andhad a smaller proportion of small stems. The lower prevalence of competition inSouth African savannas detected in this study using the same method as previousstudies is discussed, and the appropriateness of nearest-neighbour analysis isexamined.  相似文献   
4.

Introduction  

Interleukin-1 (IL-1) and tumor necrosis factor-α (TNF-α) are up-regulated in injured and osteoarthritic knee joints. IL-1 and TNF-α inhibit integrative meniscal repair; however, the mechanisms by which this inhibition occurs are not fully understood. Transforming growth factor-β1 (TGF-β1) increases meniscal cell proliferation and accumulation, and enhances integrative meniscal repair. An improved understanding of the mechanisms modulating meniscal cell proliferation and migration will help to improve approaches for enhancing intrinsic or tissue-engineered repair of the meniscus. The goal of this study was to examine the hypothesis that IL-1 and TNF-α suppress, while TGF-β1 enhances, cellular proliferation and migration in cell and tissue models of meniscal repair.  相似文献   
5.
In this qualitative study of the pattern of bile acid excretion in cholestasis, methods are described for the isolation of bile acids from large volumes of urine and plasma. The bile acids were subjected to a group separation and identified by combined gas chromatography-mass spectrometry. The techniques were developed to allow identification of the minor components of the bile acid mixture. Four bile acids that have not previously been described in human urine and plasma were detected, namely 3beta, 7alpha-dihydroxy-5beta-cholan-24-oic acid, 3alpha, 6alpha-dihydroxy-5beta-cholan-24-oic acid (hyodeoxycholic acid), 3alpha, 6alpha, 7alpha-trihydroxy-5beta-cholan-24-oic acid (hyocholic acid) and 3alpha, 7beta, 12alpha-trihydroxy-5beta-cholan-24-oic acid. In addition three C27 steroids were found; 26-hydroxycholesterol and a trihydroxy cholestane, probably 5 beta-cholestane-3alpha, 7alpha, 26-triol were found in the sulphate fraction of plasma and urine. In the plasma sample, a sulphate conjugate of 24-hydroxycholesterol was found. The presence of these compounds probably reflects the existence of further pathways for bile acid metabolism. It is not yet known whether this is a consequence of the cholestasis or whether they are also present in normal man, at much lower concentrations.  相似文献   
6.
Rutin and quercitrin are hydrolysed to quercetin, and robinin is hydrolysed to kaempferol, by faecal flora from healthy subjects. The enzymes required for these hydrolyses, namely alpha-rhamnosidase and beta-galactosidase, were produced by some strains of Bacteroides distasonis; other strains, however, synthesized beta-glucosidase. The last-named enzyme was also elaborated by Bacteroides uniformis and Bacteroides ovatus. All the enzymes were produced constitutively. A cell-free extract of B. distasonis containing beta-glucosidase displayed an enzymic activity of 1 mumol/10 min per 10 mg of protein.  相似文献   
7.
First instars of the soil-inhabiting whitefringed weevil, Naupactus leucoloma (Boheman), are a particularly good bioassay model for assessing volatile soil fumigants and biofumigants. Eggs are readily obtained and can be stored for long periods with larvae hatched on demand and the first instar is non-feeding, surviving without food or shelter. Longevity varies with temperature, but readily accommodates the period required to conduct bioassays without appreciable mortality of untreated controls. In vitro bioassays of pure methyl isothiocyanate, the active ingredient from metham sodium soil fumigant, and the less volatile 2-phenylethyl isothiocyanate, sensitively detected differences in toxicity and effects of temperature. Bioassay of volatiles emitted from hydrolysed tissue of various isothiocyanate-producing Brassica plants revealed widely varying toxicity effects, indicating that bioassays with N. leucoloma are a sensitive and relevant indicator of the potential of different plants for biofumigation of soil-borne pest organisms.  相似文献   
8.
9.
Multipurpose NTFP species typically experience higher harvest demand because of their multiple uses, which, when combined with unsustainable land use practices, may threaten population viability. We assessed local knowledge on the uses, habitat, and population status of Mimusops andongensis and Mimusops kummel, both multipurpose NTFP species in Benin, to promote their valorization and conservation and thus sustain local knowledge on their uses for domestication issues. One hundred households were randomly selected for structured interviews for M. andongensis and 500 for M. kummel. The relationship between age, sex, and ethnic groups and the species uses was assessed using comparison and correspondence analyses. Nearly all organs of the species were used. Both species were mainly exploited for medicinal purposes but also in construction and as firewood. We found similarities in some uses of the species organs, although the species occur in different ecological zones and are used by different ethnic groups. This result should be considered for the valorization of the species. Most informants reported that populations of M. andongensis were decreasing, although some felt that they were increasing, whereas less than one-third said that M. kummel was decreasing. There were strong relationships between gender, age, and ethnic affiliation of the users and the exploited organs of both species. Potential uses exist based on both the past and current uses of the species and in comparison to other countries where they are exploited. Local ethnoecological knowledge and practices will help to valorize and conserve the species. However, further research on the species’ seed germination and propagation ability are also necessary.  相似文献   
10.
Equol: a contributor to enigmatic immunoassay measurements of estrogen   总被引:1,自引:0,他引:1  
The efficacy of radioimmunoassay (RIA) for the measurement of estradiol-17 beta (E2) in murine plasma was investigated. When Sephadex LH-20 or celite column chromatography was used to separate E2 from estrone (E1) and other cross-reacting compounds, the results were erratic if small volumes of mouse plasma were resolved. Assay of a diethyl ether extract of plasma (500 microL) was the most practical method for estimating the concentration of estradiol-17 beta in mice. This method was used to determine the pattern of estrogen secretion during the estrous cycle, on the day of implantation and during pregnancy. No convincing change in estrogen secretion was observed in the diestrous/proestrous mouse. By comparison, estrogen levels were elevated during pregnancy. Taken together, these results implied that cross-reactive components in plasma masked low levels of endogenous estrogen. Further evaluation of mouse plasma and urine using a co-chromatography technique to examine estrogen elution from a reverse-phase HPLC system followed by GC/MS analysis indicated the presence of equol [7-hydroxy-3-(4-hydroxyphenyl)chroman], a phytoestrogen metabolite with a ring structure similar to estradiol-17 beta. Equol and possibly other cross-reactive components of plasma may account for the apparent lack of increased estrogen secretion during the mouse estrous cycle and on the day of implantation as determined by the radioimmunoassay of ether extracts of plasma.  相似文献   
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