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排序方式: 共有10000条查询结果,搜索用时 31 毫秒
981.
Low-level environmental lead exposure and children's intellectual function: an international pooled analysis 总被引:25,自引:0,他引:25
Lanphear BP Hornung R Khoury J Yolton K Baghurst P Bellinger DC Canfield RL Dietrich KN Bornschein R Greene T Rothenberg SJ Needleman HL Schnaas L Wasserman G Graziano J Roberts R 《Environmental health perspectives》2005,113(7):894-899
Lead is a confirmed neurotoxin, but questions remain about lead-associated intellectual deficits at blood lead levels < 10 microg/dL and whether lower exposures are, for a given change in exposure, associated with greater deficits. The objective of this study was to examine the association of intelligence test scores and blood lead concentration, especially for children who had maximal measured blood lead levels < 10 microg/dL. We examined data collected from 1,333 children who participated in seven international population-based longitudinal cohort studies, followed from birth or infancy until 5-10 years of age. The full-scale IQ score was the primary outcome measure. The geometric mean blood lead concentration of the children peaked at 17.8 microg/dL and declined to 9.4 microg/dL by 5-7 years of age; 244 (18%) children had a maximal blood lead concentration < 10 microg/dL, and 103 (8%) had a maximal blood lead concentration < 7.5 microg/dL. After adjustment for covariates, we found an inverse relationship between blood lead concentration and IQ score. Using a log-linear model, we found a 6.9 IQ point decrement [95% confidence interval (CI), 4.2-9.4] associated with an increase in concurrent blood lead levels from 2.4 to 30 microg/dL. The estimated IQ point decrements associated with an increase in blood lead from 2.4 to 10 microg/dL, 10 to 20 microg/dL, and 20 to 30 microg/dL were 3.9 (95% CI, 2.4-5.3), 1.9 (95% CI, 1.2-2.6), and 1.1 (95% CI, 0.7-1.5), respectively. For a given increase in blood lead, the lead-associated intellectual decrement for children with a maximal blood lead level < 7.5 microg/dL was significantly greater than that observed for those with a maximal blood lead level > or = 7.5 microg/dL (p = 0.015). We conclude that environmental lead exposure in children who have maximal blood lead levels < 7.5 microg/dL is associated with intellectual deficits. 相似文献
982.
Almeida NA de Sousa JT Bachion MM Silveira Nde A 《Revista latino-americana de enfermagem》2005,13(1):52-58
This study aimed to evaluate the effect of respiration and relaxation techniques on pain and anxiety during labor. Seventeen parturients (Control Group--CG) received routine care and nineteen (Experimental Group--EG) were orientated and stimulated to perform respiration and relaxation techniques. Pain was evaluated by means of the visual analogy scale and anxiety by means of the anxiety inventories--trait and state. Pain intensity increased along with the evolution of the delivery for both groups. In the latent phase, anxiety levels were low for both groups; in the active phase, levels were average for CG and low for EG. In the transition phase, levels were average and, in the immediate post-labor phase, low for both groups. It was concluded that the techniques used did not reduce pain intensity, but provided EG with lower anxiety levels for a longer time during labor. 相似文献
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986.
987.
Theisen J Peters JH Fein M Hughes M Hagen JA Demeester SR Demeester TR Laird PW 《Annals of surgery》2005,241(1):63-68
SUMMARY BACKGROUND DATA: Duodenogastric-esophageal reflux disease is directly linked to Barrett's esophagus and to the development of esophageal adenocarcinoma. Despite this link, little is known about the mutagenic potential of refluxed material on the esophageal mucosa. We hypothesize that the reflux of gastric and duodenal content causes mutations in esophageal mucosa in vivo. METHODS: Seven Sprague Dawley/Big Blue F1 lacI transgenic rats underwent esophagoduodenostomy (ED) to surgically create duodeno-gastric-esophageal reflux. Fourteen nonoperated rats served as negative (n = 7) and as positive (n = 7/methyl-N-amyl-nitrosamine [MNAN] intraperitoneally) controls. The animals were killed 16 weeks after operation or injection, the entire esophageal mucosa was harvested, and mutation frequency was determined through standard Big Blue Mutagenesis Assay. RESULTS: Gross esophagitis was evident in all operated animals. The frequency of lacI mutations in esophageal mucosal cells of animals with ED was significantly higher, nearly 1.5-fold, than that of nonoperated animals. Nitrosamine administration resulted in a nearly 20-fold increase of lacI mutation frequency. Thirteen mutations were successfully sequenced, 46% occurred at CpG dinucleotide sites and 61% were either C to T or G to A transitions. CONCLUSIONS: The data provide preliminary evidence of the mutagenic potential of bile reflux on esophageal epithelium. The specific mutations are markedly higher than would be expected by chance and are similar to that found in p53 mutations of human esophageal adenocarcinoma, providing a link to human esophageal cancer. 相似文献
988.
989.
Background/Purpose
Cysteine is an amino acid necessary for the synthesis of all proteins, the antioxidant glutathione, and the neuromodulator taurine. Whether cysteine is an essential amino acid for premature neonates remains controversial. Using a [13C6]glucose precursor in very-low-birth weight (VLBW) premature neonates, we measured the 13C content of cysteine in hepatically derived apolipoprotein (apo) B-100 and in the plasma to determine whether cysteine synthesis occurs and to relate minimum synthetic capacity to neonatal maturity.Methods
Twelve VLBW premature neonates (birth weight, 907 ± 274 [SD] g; gestational age, 26.8 ± 2.4 weeks) were studied on day of life 7.8 ± 4.2 while on total parenteral nutrition (TPN) for 5.6 ± 4.5 days. A 4-hour intravenous infusion of [13C6]glucose was administered. Blood samples were obtained immediately before and at the end of the infusion. Isotopic enrichment of cysteine was determined by gas chromatography/mass spectrometry. Analysis of variance, Student's t test, and linear regression were used for comparisons.Results
The 13C isotope ratio of apo B-100-derived cysteine after the [13C6]glucose infusion was significantly higher than baseline (18.57 ± 0.38 [SEM] vs 17.54 ± 0.25 mol%, P < .05). The 13C isotope ratio of plasma cysteine was also significantly higher than baseline (17.36 ± 0.25 vs 16.91 ± 0.16 mol%, P < .05). When expressed as a product/precursor ratio, the mole percent above baseline of [13C]apo B-100 cysteine/[13C6]glucose correlated with birth weight (r = 0.74, P < .01).Conclusions
Very low-birth weight neonates are capable of cysteine synthesis as evidenced by incorporation of 13C label into hepatically derived apo B-100 cysteine and plasma cysteine from a glucose precursor. The minimum capacity for intrahepatic cysteine synthesis appears to be directly proportional to the maturity of the neonate and may impact the capabilities of VLBW neonates to counteract oxidative stresses such as bronchopulmonary dysplasia and necrotizing enterocolitis. 相似文献990.
Javid PJ Collier S Richardson D Iglesias J Gura K Lo C Kim HB Duggan CP Jaksic T 《Journal of pediatric surgery》2005,40(6):1015-1018