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991.
992.
Koyama T Kirjavainen PV Fisher C Anukam K Summers K Hekmat S Reid G 《Canadian journal of microbiology》2010,56(9):730-738
Microbial exposure may direct the immune system away from allergic-type responses, but until now probiotic interventions have had limited success in the prevention and treatment of allergic diseases. In this study, a novel probiotic mixture was specifically created based on preliminary in vitro investigations on pollen-induced immune responses. A mixture with Lactobacillus rhamnosus GR-1 and a novel fecal Bifidobacterium adolescentis isolate was formulated into a yogurt and tested for its effects in 36 subjects with allergic rhinitis over 2 pollen seasons in a double-blind, placebo-controlled trial. The new formulation was well tolerated, but did not have significant effects on the quality of life scores, use of antihistamines, or eosinophil cationic protein concentration in nasal lavage. However, at the end of the grass pollen season, serum IL-10 and IL-12 levels were increased in the probiotic group compared to the controls. During the ragweed season, the serum TGF-β levels were significantly higher in the probiotic group than in the controls. In conclusion, the novel probiotic formulation had potentially desirable effects on the cytokine profile of patients with allergic rhinitis, but provided few clinical benefits. The study highlights the challenges in designing efficient immunomodulatory probiotic therapies based upon in vitro findings. 相似文献
993.
994.
Masaki Takahashi Kentarou Ushijima Yohei Hayashi Tomohiro Maekawa Hitoshi Ando Shu-ichi Tsuruoka Akio Fujimura 《Life sciences》2010,86(1-2):24-29
AimsWhile glucocorticoids are widely used to treat patients with various diseases, they often cause adverse effects such as bone fractures. In this study, we investigated whether the decrease in bone density induced by glucocorticoid therapy was ameliorated by optimizing a dosing-time.Main methodsRats were administered with dexamethasone (Dex) orally (1 mg/kg/day) for 6 weeks at a resting or an active period. After the end of the treatment, bone density of femur, biomarkers of bone formation and resorption, and other biomedical variables were measured.Key findingsBone density of femur was significantly decreased by the 6-week treatment with Dex, and the degree of decrease in the 14 HALO (hours after light on) dosing group (an active period) was larger than that in the 2 HALO dosing group (a resting period). Although urinary calcium excretion was accelerated by Dex treatment, secondary hyperparathyroidism was not detected. Histomorphometry analysis showed that Dex suppressed bone resorption, which was larger in the 2 HALO than in the 14 HALO groups. These data indicate that Dex equally suppressed bone formation in the 2 and 14 HALO groups, but inhibited bone resorption more in the 2 HALO than in the 14 HALO groups.SignificanceThis study shows that the decrease in bone density induced by Dex was changed by its dosing-time. 相似文献
995.
996.
Geometrical similarity analysis of photosynthetic light response curves, light saturation and light use efficiency 总被引:1,自引:0,他引:1
Light absorption and use efficiency (LAUE mol mol−1, daily gross photosynthesis per daily incident light) of each leaf depends on several factors, including the degree of light
saturation. It is often discussed that upper canopy leaves exposed to direct sunlight are fully light-saturated. However,
we found that upper leaves of three temperate species, a heliophytic perennial herb Helianthus tuberosus, a pioneer tree Alnus japonica, and a late-successional tree Fagus crenata, were not fully light-saturated even under full sunlight. Geometrical analysis of the photosynthetic light response curves
revealed that all the curves of the leaves from different canopy positions, as well as from the different species, can be
considered as different parts of a single non-rectangular hyperbola. The analysis consistently explained how those leaves
were not fully light-saturated. Light use optimization models, called big leaf models, predicted that the degree of light
saturation and LAUE are both independent of light environment. From these, we hypothesized that the upper leaves should not
be fully light-saturated even under direct sunlight, but instead should share the light limitation with the shaded lower-canopy
leaves, so as to utilize strong sunlight efficiently. Supporting this prediction, within a canopy of H. tuberosus, both the degree of light saturation and LAUE were independent of light environment within a canopy, resulting in proportionality
between the daily photosynthesis and the daily incident light among the leaves. 相似文献
997.
Hiroyuki Oka Tetsuo Koyama Ken Hatano Daiyo Terunuma Koji Matsuoka 《Bioorganic & medicinal chemistry letters》2010,20(6):1969-1971
Synthesis of bi-fluorescence-labeled maltooligosaccharides for amylase assay was accomplished. Preliminary biological evaluation of both bi-fluorescence-labeled maltohexasaccharide and maltose using α-amylase was carried out, and the hexaosyl derivative showed unique variation on the basis of fluorescence resonance energy transfer (FRET). 相似文献
998.
Koji Matsuoka Reina Kaneko Tetsuo Koyama XiaoTao Ma Yasuaki Esumi Takemichi Nakamura Ken Hatano Daiyo Terunuma 《Bioorganic & medicinal chemistry letters》2010,20(16):4906-4910
An efficient synthesis of sialyllactosamine (SiaLacNAc) clusters using carbosilanes as core scaffolds has been accomplished by means of chemical and enzymatic approaches. N-Acetyl-d-glucosamine (GlcNAc) clusters having O-glycosidic linkage or S-glycosidic linkage were chemically synthesized from known intermediates in high yields. The GlcNAc clusters were first used as substrates for β1,4 galactosyl transferase using UDP-galactose (UDP-Gal) as a sugar source to provide corresponding N-acetyllactosamine clusters. Further sugar elongation of the LacNAc clusters was demonstrated using α2,3 sialyl transferase and CMP-neuraminic acid (CMP-NANA) to yield the corresponding SiaLacNAc clusters. 相似文献
999.
1000.
Wildfire Effects on Soil Gross Nitrogen Transformation Rates in Coniferous Forests of Central Idaho, USA 总被引:2,自引:0,他引:2
Forest fires often result in a series of biogeochemical processes that increase soil nitrate (NO3 ?) concentrations for several years; however, the dynamic nature of inorganic nitrogen (N) cycling in the plant–microbe–soil complex makes it challenging to determine the direct causes of increased soil NO3 ?. We measured gross inorganic N transformation rates in mineral soils 2 years after wildfires in three central Idaho coniferous forests to determine the causes of the elevated soil NO3 ?. We also measured key factors that could affect the soil N processes, including temperature during soil incubation in situ, soil water content, pH and carbon (C) availability. We found no significant differences (P = 0.461) in gross nitrification rates between burned and control soils. However, microbial NO3 ? uptake rates were significantly lower (P = 0.078) in burned than control soils. The reduced consumption of NO3 ? caused slightly elevated NO3 ? concentrations in the burned soils. C availability was positively correlated with microbial NO3 ? uptake rates. Despite reduced microbial NO3 ? uptake capacity in the burned soils, soil microbes were a strong enough N sink to maintain low soil NO3 ? concentrations 2 years post fire. Soil NH4 + concentrations between the treatments were not significantly different (P = 0.673). However, gross NH4 + production and microbial uptake rates in burned soils were significantly lower (P = 0.028 and 0.035, respectively) than in the controls, and these rates were positively correlated with C availability. Our results imply that C availability is an important factor regulating soil N cycling of coniferous forests in the region. 相似文献