全文获取类型
收费全文 | 4055篇 |
免费 | 341篇 |
国内免费 | 117篇 |
专业分类
耳鼻咽喉 | 122篇 |
儿科学 | 101篇 |
妇产科学 | 80篇 |
基础医学 | 520篇 |
口腔科学 | 101篇 |
临床医学 | 477篇 |
内科学 | 750篇 |
皮肤病学 | 147篇 |
神经病学 | 263篇 |
特种医学 | 175篇 |
外科学 | 693篇 |
综合类 | 195篇 |
一般理论 | 2篇 |
预防医学 | 160篇 |
眼科学 | 91篇 |
药学 | 315篇 |
中国医学 | 31篇 |
肿瘤学 | 290篇 |
出版年
2023年 | 26篇 |
2022年 | 72篇 |
2021年 | 123篇 |
2020年 | 71篇 |
2019年 | 77篇 |
2018年 | 99篇 |
2017年 | 87篇 |
2016年 | 127篇 |
2015年 | 124篇 |
2014年 | 134篇 |
2013年 | 205篇 |
2012年 | 245篇 |
2011年 | 234篇 |
2010年 | 169篇 |
2009年 | 130篇 |
2008年 | 161篇 |
2007年 | 237篇 |
2006年 | 158篇 |
2005年 | 174篇 |
2004年 | 170篇 |
2003年 | 134篇 |
2002年 | 113篇 |
2001年 | 101篇 |
2000年 | 117篇 |
1999年 | 91篇 |
1998年 | 70篇 |
1997年 | 74篇 |
1996年 | 53篇 |
1995年 | 64篇 |
1994年 | 53篇 |
1993年 | 41篇 |
1992年 | 42篇 |
1991年 | 33篇 |
1990年 | 54篇 |
1989年 | 70篇 |
1988年 | 44篇 |
1987年 | 41篇 |
1986年 | 32篇 |
1985年 | 32篇 |
1984年 | 28篇 |
1983年 | 23篇 |
1982年 | 17篇 |
1981年 | 21篇 |
1980年 | 19篇 |
1977年 | 18篇 |
1976年 | 19篇 |
1973年 | 13篇 |
1968年 | 14篇 |
1965年 | 13篇 |
1959年 | 13篇 |
排序方式: 共有4513条查询结果,搜索用时 15 毫秒
1.
2.
In the 6th Basic Plan for Long-Term Electricity Supply and Demand (6th BPE) for Korea, for the first time, the environmental costs of air pollution caused by oxides of sulfur (SOx), oxides of nitrogen (NOx), and particulate matters (PM) from power plants were estimated and included. However, several deficiencies in evaluating the environmental costs were found. In this study, (1) the validity of the environmental costs used in the 6th BPE was assessed, (2) a systematic approach was suggested and used to improve the environmental costs estimation, and (3) the sensitivity of the cost of generating electricity to the environmental costs by fuel type with the proposed approach was discussed. We found that the applied environmental costs used in the 6th BPE did not fully include the demographic characteristics of Korea. By applying more realistic parameter values, it was found that the newly estimated environmental cost was about 23 times higher than the cost estimated in the original 6th BPE for coal-fired power plants and about 1.5 times higher for liquefied natural gas (LNG)-fired power plants, suggesting that LNG-fired power plants are more economical if using more realistic environmental costs. Thus, it is critical to check the validity of parameter values when calculating environmental costs. 相似文献
3.
Marta López-Fauqued Laura Campora Frédérique Delannois Mohamed El Idrissi Lidia Oostvogels Ferdinandus J. De Looze Javier Diez-Domingo Thomas C. Heineman Himal Lal Janet E. McElhaney Shelly A. McNeil Wilfred Yeo Fernanda Tavares-Da-Silva 《Vaccine》2019,37(18):2482-2493
Background
The ZOE-50 (NCT01165177) and ZOE-70 (NCT01165229) phase 3 clinical trials showed that the adjuvanted recombinant zoster vaccine (RZV) was ≥90% efficacious in preventing herpes zoster in adults. Here we present a comprehensive overview of the safety data from these studies.Methods
Adults aged ≥50 (ZOE-50) and ≥70 (ZOE-70) years were randomly vaccinated with RZV or placebo. Safety analyses were performed on the pooled total vaccinated cohort, consisting of participants receiving at least one dose of RZV or placebo. Solicited and unsolicited adverse events (AEs) were collected for 7 and 30?days after each vaccination, respectively. Serious AEs (SAEs) were collected from the first vaccination until 12?months post-last dose. Fatal AEs, vaccination-related SAEs, and potential immune-mediated diseases (pIMDs) were collected during the entire study period.Results
Safety was evaluated in 14,645 RZV and 14,660 placebo recipients. More RZV than placebo recipients reported unsolicited AEs (50.5% versus 32.0%); the difference was driven by transient injection site and solicited systemic reactions that were generally seen in the first week post-vaccination. The occurrence of overall SAEs (RZV: 10.1%; Placebo: 10.4%), fatal AEs (RZV: 4.3%; Placebo: 4.6%), and pIMDs (RZV: 1.2%; Placebo: 1.4%) was balanced between groups. The occurrence of possible exacerbations of pIMDs was rare and similar between groups. Overall, except for the expected local and systemic symptoms, the safety results were comparable between the RZV and Placebo groups irrespective of participant age, gender, or race.Conclusions
No safety concerns arose, supporting the favorable benefit-risk profile of RZV. 相似文献4.
5.
Rebecca P. Ang Robert M. Klassen Wan Har Chong Vivien S. Huan Isabella Y.F. Wong Lay See Yeo Lindsey L. Krawchuk 《Journal of adolescence》2009,32(5):1225-1237
We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations. 相似文献
6.
7.
8.
Respiratory tract infections due to Branhamella catarrhalis: epidemiological data from Western Australia 总被引:3,自引:0,他引:3
During a 3-year period Branhamella catarrhalis was isolated in significant numbers from 239 (1.3%) of 19,488 specimens of sputum sent for routine microbiological examination at a 700-bed general hospital. The majority of patients (83%) were over 60 years of age and 65% were male. There was a distinct seasonal variation in isolations with a peak incidence during the winter and early spring, a pattern not found with other pathogens. Susceptibility to amoxycillin decreased by approximately 50% over the 3 years, corresponding to an increased incidence of beta-lactamase-producing strains. There were minimal changes in susceptibility to other antimicrobial agents. Underlying pulmonary disease was the major factor predisposing to B. catarrhalis infection, and 71% of patients were smokers or ex-smokers. 相似文献
9.
10.
Gopala K RANGAN Yiping WANG Yuet-Ching TAY Liguang CHEN David CH HARRIS 《Nephrology (Carlton, Vic.)》1998,4(1-2):57-64
SUMMARY: The effect of mild acute tubular injury on the progression of tubulointerstitial fibrosis was studied in pair-fed uninephrectomized male Wistar rats with established adriamycin nephrosis ( n = 34). Rats were stratified into three groups according to endogenous creatinine clearance (CrCl), proteinuria (Upr) and body weight (BW): (i) group 1 (Fe, n = 12) received a single intraperitoneal injection of ferric nitrilotriacetate (5 mg Fe/kg BW); (ii) group 2 (G, n = 10) three daily subcutaneous injections of gentamicin (60 mg/kg BW) and; (iii) group 3 (C, n = 12) saline injections. Serial CrCl (day 2, day 5, weeks 2, 4, 6 and 8) and renal histology (week 8) were examined following administration of nephrotoxin. CrCl was reduced on d2 (Fe: 0.78 ± 0.23 mL/min; mean ± SD) and day 5 (G: 0.91 ± 0.36 mL/min) as compared with C (1.22 ± 0.12 mL/min; P <0.05). There was no change in the serum creatinine and functional recovery occurred by d5 (Fe) and week 2 (G). Upr decreased transiently in G at week 2 (G: 482 ± 208 mg/day vs C: 716 ± 233; P = 0.05) despite similar food intake, baseline Upr and CrCl. At week 8, CrCl in Fe (0.84 ± 0.40 mL/min) was similar to C (0.84 ± 0.58 mL/min), whereas in G it remained stable (1.27 ± 0.39 mL/min; P <0.05). By morphometric analysis, mean relative interstitial volume (RIV) and glomerulosclerosis (GS) in Fe (RIV: 28.5 ± 13.4%; GS: 10.3 ± 12.3%) was no different to C (RIV: 24.5 ± 12.5%; GS: 20.9 ± 20.0%), whereas both parameters were reduced in G (RIV: 14.1 ± 8.1%; GS: 4.0 ± 4.8%; P <0.05). Mild gentamicin nephrotoxicity therefore reduced the progression of adriamycin nephrosis. the mechanism of this finding is unclear, but it may relate to altered glomerular and tubular cell handling of protein. 相似文献