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141.
Forssman Reactivity and Cell Contacts in Cultured Hamster Cells 总被引:2,自引:0,他引:2
THE net synthesis of Forssman hapten glycolipid is enhanced in contact-inhibited NIL cells, particularly in the early stages of contact inhibition1,2. We have now found that the surface reactivity of cells to anti-Forssman glycolipid antiserum is, however, significantly decreased when they are contact inhibited. 相似文献
142.
ORGANISMS existing in mutualistic interrelationships often show unusual chemical interdependencies; for example, the pupation of the beetle Xyleborus ferrugineus depends on a sterol source provided by its ectosymbiotic fungi1, 2. We now report that bacterial endosymbiotes are transmitted transovarially in this beetle. We also present evidence that natural maturation of the oocytes and haploid parthenogenesis in this insect depend on its bacterial symbiotes. 相似文献
143.
A previous study showed that some individuals of the tetraploid Galápagos endemic Scalesia affinis were able to produce offspring after selfing. The present study compares the fitness of self-pollinated offspring with the
fitness of cross-pollinated offspring. Germination success, seedling survival, and four different growth parameters was measured.
In most of the studied characters selfed offspring were significantly inferior to outcrossed progeny. The effect was very
clear in germination and survival. Outcrossed embryos were 3.4 times more likely to germinate than those that were selfed-fertilized,
and the mortality was 84% higher among selfed individuals. Also, there was no genetic variation in inbreeding depression.
The present study is based on material from a large population on Isabela Island, Galápagos. At other localities in the archipelago,
populations have been through recent dramatic bottlenecks due to the grazing of introduced mammals. Considering the significant
inbreeding depression found in the large population and the presence of a partial self-incompatibility system, these small
populations are likely to be highly vulnerable and their future survival critically threatened. 相似文献
144.
Katalin Nagy István Berhés Tibor Kovács Norbert Kávási János Somlai Tamás Bender 《Radiation and environmental biophysics》2009,48(3):311-315
Radon bath is a well-established modality of balneotherapy for the management of degenerative musculoskeletal disorders. The
present study was conducted to ascertain whether baths of relatively low (80 Bq/l) radon concentration have any influence
on the functioning of the endocrine system. In the study, a non-randomized pilot study, 27 patients with degenerative musculoskeletal
disorders received 30-min radon baths (of 31–32°C temperature and 80 Bq/l average radon concentration) daily, for 15 days.
Twenty-five patients with matching pathologies were subjected to balneotherapy according to the same protocol, using thermal
water with negligible radon content (6 Bq/l). Serum thyroid stimulating hormone, prolactin, cortisol, adrenocorticotropic
hormone, and dehydroepiandrosterone levels were measured before and after a balneotherapy course of 15 sessions. Comparison
of the accumulated data using the Wilcoxon test did not reveal any significant difference between pre- and post-treatment
values or between the two patient groups. It is noted that while the beneficial effects of balneotherapy with radon-containing
water on degenerative disorders is widely known, only few data have been published in the literature on its effect on endocrine
functions. The present study failed to demonstrate any substantial effect of thermal water with relatively low radon content
on the functioning of the endocrine system. 相似文献
145.
Cheng-Yu Hung Yi-Yen Chen Tsai-Wen Hsu Tsurng-Juhn Huang Tzen-Yuh Chiang 《Conservation Genetics》2008,9(5):1337-1339
Suzukia shikikunensis Kudo is an endemic plant in Taiwan and suffers habitat destruction caused by human overexploitation. In this study, we developed
12 microsatellite primer pairs for genetic study. These markers were screened for 24 samples collected from wild populations distributed in Taiwan, and for a sister species
S. luchuensis collected from Yonaguni and Lutao Islands. The number of alleles ranged from 5 to 14. The expected (H
E) and observed (H
O) heterozygosities were 0.65–0.922 and 0–0.625, respectively. All loci were significantly deviated from Hardy–Weinberg equilibrium
due to the heterozygote deficiency. These primers amplifying microsatellites in the two species may provide a useful tool
for population genetics to establish conservation strategy. 相似文献
146.
Intact drylands are highly evolved and complex ecosystems, which allow them to be productive despite harsh environmental conditions. However, drylands are particularly susceptible to degradation, even after minor disturbance events. Conditions for natural plant recruitment in dryland systems are spatially and temporally irregular, which can create challenges for restoration. Large-scale restoration and rehabilitation of dryland ecosystems have become a global concern, prompted by ever-increasing anthropogenic pressure and associated degradation of these natural systems worldwide. The success of plant reestablishment programs in these regions is closely linked to both ecological and socioeconomic opportunities and limitations. This special issue brings together papers that discuss the roles which ecological and socioeconomic factors play in influencing dryland ecosystem restoration outcomes. We aim to (1) highlight the current status of recovery efforts taking place across a range of dryland ecosystems, emphasize advances in the region-specific understanding of plant community development, and (2) provide comparisons between the primary drivers and limitations to restoration that exist across dryland systems. 相似文献
147.
148.
Yu Wang Miao Fan Faiza Amber Siddiqui Meilian Wang Wei Sun Xue Sun Wenjia Lei Ying Zhang 《Cardiovascular ultrasound》2017,15(1):17
Background
Identification of prenatal ventriculoarterial connections in fetuses with conotruncal anomalies (CTA) remains one of the greatest challenges for sonographers performing screening examinations. Herein, we propose a novel protocol of 4D volume analysis that identifies ventriculoarterial connections and evaluate its clinical utility in routine screenings.Methods
Twenty-nine cases of transposition of the great arteries (TGA), 22 cases of double-outlet right ventricle (DORV), 36 cases of tetralogy of Fallot (TOF), 14 cases of truncus arteriosus (TCA), and randomly selected 70 normal fetuses were reviewed in this study. All cases were evaluated using 2D data alone (2D method), post-processing volumes with no exact algorithm (4D-1 method), or with the proposed algorithm (4D-2 method), or using the 2D and 4D data together (combined method). Comparisons were made to evaluate the detection rate of ventriculoarterial connections for these different methods.Results
During 18–28 gestational weeks, the detection rate of 4D-2 modality was satisfactory. The detection rate of the combined method was significantly higher than 2D method in the identification of TGA, TOF, and TCA. The detection rate of 4D-1 method was significantly lower than 4D ?2 modality for CTA fetuses. During late pregnancy, the detection rate for both 4D modalities was very low due to the poor quality of the 4D volumes.Conclusions
We proposed a detailed protocol, which allowed the examiner to identify fetal ventriculoarterial connections by 4D volumes. Inclusion of blood information into the volumes improved diagnosis. Our findings suggest that the incorporation of 4D STIC into routine screenings could improve the detection for TGA, TOF, and TCA.149.
Michael D. Timmons Barbara L. Knutson Sue E. Nokes Herbert J. Strobel Bert C. Lynn 《Applied microbiology and biotechnology》2009,82(5):929-939
Clostridium thermocellum is a candidate organism for consolidated bioprocessing of lignocellulosic biomass into ethanol. However, commercial use is limited
due to growth inhibition at modest ethanol concentrations. Recently, an ethanol-adapted strain of C. thermocellum was produced. Since ethanol adaptation in microorganisms has been linked to modification of membrane lipids, we tested the
hypothesis that ethanol adaptation in C. thermocellum involves lipid modification by comparing the fatty acid composition and membrane anisotropy of wild-type and ethanol-adapted
strains. Derivatization to fatty acid methyl esters provided quantitative lipid analysis. Compared to wild-type, the ethanol-adapted
strain had a larger percentage of fatty acids with chain lengths >16:0 and showed a significant increase in the percentage
of 16:0 plasmalogens. Structural identification of fatty acids was confirmed through mass spectral fragmentation patterns
of picolinyl esters. Ethanol adaptation did not involve modification at sites of methyl branching or the unsaturation index.
Comparison of steady-state fluorescence anisotropy experiments, in the absence and presence of ethanol, provided evidence
for the effects of ethanol on membrane fluidity. In the presence of ethanol, both strains displayed increased fluidity by
approximately 12%. These data support the model that ethanol adaptation was the result of fatty acid changes that increased
membrane rigidity that counter-acted the fluidizing effect of ethanol. 相似文献
150.
Karol Szeszko Nina Smolinska Marta Kiezun Kamil Dobrzyn Anna Maleszka Tadeusz Kaminski 《Functional & integrative genomics》2016,16(2):101-114
Reproductive functions are closely related to nutritional status. Recent studies suggest that adiponectin may be a hormonal link between them. Adiponectin is an adipocytokine, abundantly expressed in adipose tissues. It plays a dominant role in lipid and carbohydrate metabolism by stimulating fatty acid oxidation, decreasing plasma triglycerides, and increasing cells’ sensitivity to insulin and has direct antiatherosclerotic effects. The hormone is also postulated to play a modulatory role in the regulation of the reproductive system. The aim of this study was to identify differentially expressed genes (DE-genes) in response to adiponectin treatment of porcine luteal ovarian cells. The global expression of genes in the porcine ovary was investigated using the Porcine (V2) Two-color gene expression microarray, 4?×?44 (Agilent, USA). Analysis of the microarray data showed that 701 genes were differentially expressed and 389 genes showed a fold change greater than 1.2 (p?<?0.05). Among this number, 186 genes were up-regulated and 203 were down-regulated. The list of DE-genes was used for gene ontology analyses. The biological process list was generated from up-regulated and down-regulated DE-genes. We found that up-regulated products of DE-genes take part in 30 biological processes and down-regulated products in 9. Analysis of the interaction network among DE-genes showed that adiponectin interacts with genes involved in important processes in luteal cells. These results provide a basis for future work describing the detailed interactions and relationships explaining local regulation of adiponectin actions in the ovary of pigs. 相似文献