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排序方式: 共有1078条查询结果,搜索用时 15 毫秒
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Kai-Hang Yiu MBBS Chung-Wah Siu MBBS Chu-Pak Lau MD Kathy L.F. Lee MBBS Hung-Fat Tse MD 《Heart rhythm》2007,4(2):221-223
We report a case of successful transvenous, catheter-based, cavotricuspid isthmus ablation for treatment of atrial flutter using microwave energy. Microwave energy was delivered at 900–930 MHz using 21 W of power. Bidirectional cavotricuspid isthmus conduction block was achieved by microwave ablation without any patient discomfort or complication during the procedure. Our initial experience suggests that transcatheter microwave ablation is feasible for the cure of typical atrial flutter. 相似文献
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Verna W. Y. Yiu Robert P. Dluhy Richard P. Lifton Lisa M. Guay-Woodford 《Pediatric nephrology (Berlin, Germany)》1997,11(3):343-346
In evaluating hypertensive children and adolescents, the etiological considerations should include a set of inherited disorders
that share very low plasma renin activity (PRA) as a common feature. In particular among these disorders, glucocorticoid remediable
aldosteronism (GRA) appears to be emerging as an important etiology of hypertension in the pediatric population. We report
the evaluation of a 9-year-old Caucasian girl who presented with severe hypertension and a strong family history of early-onset
hypertension. Her suppressed PRA, her family history, and her failure to respond to conventional antihypertensive therapy
raised GRA as a potential etiology. The diagnosis was confirmed by an elevated ratio of urinary 18-oxotetrahydrocortisol to
urinary tetrahydroaldosterone and genetic testing, which demonstrated the chimeric gene duplication. The molecular pathogenesis
of GRA and the clinical implications are reviewed.
Received May 15, 1996; received in revised form and accepted September 16, 1996 相似文献
5.
This study evaluated the change in the ultimate tensile strength (UTS) of five polymerised resin blends of increasing hydrophilicity, after ageing in distilled water or silicon oil. Resin blocks were prepared from each resin blend by dispensing the uncured resin into a flexible, embedding mould, containing multiple cavities. The resins were polymerised in the moulds under nitrogen at 551.6 kPa and light-activated at 125 degrees C for 10 min. After dry ageing for 24 h at 37 degrees C, the middle third of each resin specimen was trimmed into an 'I' shape. Fifteen control specimens were randomly selected from each resin blend for baseline UTS evaluation. The UTS of the experimental specimens were determined after 1, 3, 6 and 12 months of ageing in water or oil. The UTS of each group of resins at different storage periods in water or oil were analysed using the Friedman multiple ANOVA on ranks and Dunn's multiple comparison tests at 95% confidence level. Significant reduction (p < 0.01) in UTS was observed in Groups II-V resins after 12-month storage in water, while the most hydrophobic Group I resin showed no significant change (p > 0.05) in the same period. The percentage reduction in UTS increased with the hydrophilicity of the resin blends. Long-term water storage of hydrophilic resin blends such as those employed in dentine adhesives, resulted in a marked reduction in their mechanical strength that may compromise the durability of resin-dentine bonds. 相似文献
6.
Song JZ Yiu HH Qiao CF Han QB Xu HX 《Journal of pharmaceutical and biomedical analysis》2008,47(2):399-406
Eleven major isoflavonoids and three major astragalosides in the xylem and bark of cultivated Radix Astragali (RA) from different cultivated regions of China were determined by high performance liquid chromatography. The results showed that the contents of astragalosides in the bark are up to 74-fold higher than in the xylem, and that thin roots contained more astragalosides than thick roots. Although the contents of isoflavonoids varied between samples, no significant difference was observed between the isoflavonoids content of xylem and bark, or between that of thin and thick roots. It was also found that the chemical profile of isoflavonoids in the xylem and bark are related to their cultivated regions. Constituents in either xylem or bark were divided into five groups according to their chemical structures: (1) Group 1 (G1), contained calycosin and related constituents; (2) Group 2 (G2), contained ononin and related constituents; (3) Group 3 (G3), contained (6aR,11aR)-3-hydroxy-9,10-dimethoxypterocarpan and related constituents; (4) Group 4 (G4), contained (3R)-7,2′-dihydroxy-3′,4′-dimethoxyisoflavan and related constituents; and (5) Group 5 (G5), contained astragalosides, compounds AG I, AG II, and AG IV. Based on the integrated contents of constituents in each group, the cultivated region of RA was successfully distinguished by principal components analysis (PCA). Chemical constituents in RA cultivated from different regions of China were compared and it was concluded that the quality of thin RA roots is better than thick RA roots. 相似文献
7.
The mechanism of microsatellite instability is different in synchronous and metachronous colorectal cancer 总被引:1,自引:0,他引:1
Fernando?S.?Velayos Suk-Hwan?Lee Hongming?Qiu Sharon?Dykes Raymond?Yiu Jonathan?P.?Terdiman Julio?Garcia-AguilarEmail author 《Journal of gastrointestinal surgery》2005,9(3):329-335
MLH1 promoter hypermethylation has been described as the primary mechanism for high-frequency microsatellite instability (MSI-H)
in sporadic colorectal cancers (CRCs). The underlying molecular mechanism for microsatellite instability (MSI) in synchronous
and metachronous CRCs is not well described. A total of 33 metachronous CRC patients and 77 synchronous CRC patients were
identified from 2884 consecutive patients undergoing cancer surgery in an academic center. Evaluable tumors were tested for
MSI, immunohistochemistry for MLH1 and MSH2 protein expression, and hypermethylation of the MLH1 promoter. MSI-H tumors were
found in 12 (36%) metachronous CRC patients and 29 (38%) synchronous CRC patients. MSI-H metachronous CRC patients were younger
at index cancer diagnosis (64 vs. 76 years, P = 0.01) and more often were diagnosed before 50 years of age (4 of 12 vs. 0 of 29, P = 0.005). Loss of MLH1 expression associated with promoter hypermethylation was common in all patients, although more common
in MSI-H synchronous patients (50% metachronous vs. 83% synchronous, P = 0.03). Overall, MLH1 promoter hypermethylation was seen in 7 of 17 (41%) metachronous and 44 of 54 (81%) synchronous MSI-H
CRCs tested (P = 0.004). Although MSI occurred with equal frequency among patients with synchronous and metachronous CRCs, the underlying
mechanism for MSI was different. Observed differences in MLH1 promoter hypermethylation and patient characteristics suggest
most MSI-H synchronous CRCs in our population were sporadic in origin. In contrast, more MSI-H metachronous CRCs were associated
with patient and tumor characteristics suggestive of underlying hereditary nonpolyposis CRC.
Presented as a poster at Digestive Disease Week 2001, Atlanta, Georgia, May 20–23, 2001. 相似文献
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Kung SW Chan YC Lau FL 《Annals of emergency medicine》2008,51(1):108; author reply 108-108; author reply 109