全文获取类型
收费全文 | 25691篇 |
免费 | 1794篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 90篇 |
儿科学 | 1483篇 |
妇产科学 | 604篇 |
基础医学 | 2211篇 |
口腔科学 | 110篇 |
临床医学 | 2497篇 |
内科学 | 7836篇 |
皮肤病学 | 462篇 |
神经病学 | 2006篇 |
特种医学 | 224篇 |
外科学 | 2945篇 |
综合类 | 606篇 |
现状与发展 | 1篇 |
一般理论 | 6篇 |
预防医学 | 2222篇 |
眼科学 | 954篇 |
药学 | 1115篇 |
2篇 | |
中国医学 | 50篇 |
肿瘤学 | 2199篇 |
出版年
2024年 | 41篇 |
2023年 | 247篇 |
2022年 | 229篇 |
2021年 | 346篇 |
2020年 | 338篇 |
2019年 | 119篇 |
2018年 | 466篇 |
2017年 | 495篇 |
2016年 | 550篇 |
2015年 | 534篇 |
2014年 | 445篇 |
2013年 | 709篇 |
2012年 | 1993篇 |
2011年 | 2270篇 |
2010年 | 795篇 |
2009年 | 772篇 |
2008年 | 2434篇 |
2007年 | 2314篇 |
2006年 | 2001篇 |
2005年 | 2088篇 |
2004年 | 2042篇 |
2003年 | 2079篇 |
2002年 | 1673篇 |
2001年 | 1249篇 |
2000年 | 282篇 |
1999年 | 137篇 |
1998年 | 199篇 |
1997年 | 116篇 |
1996年 | 90篇 |
1995年 | 57篇 |
1994年 | 71篇 |
1993年 | 36篇 |
1992年 | 41篇 |
1991年 | 32篇 |
1990年 | 37篇 |
1989年 | 36篇 |
1988年 | 36篇 |
1987年 | 38篇 |
1986年 | 33篇 |
1985年 | 24篇 |
1984年 | 24篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 19篇 |
1980年 | 12篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1970年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Ekouevi DK Rouet F Becquet R Inwoley A Viho I Tonwe-Gold B Bequet L Dabis F Leroy V;ANRS / Ditrame Plus Study Group 《Journal of acquired immune deficiency syndromes (1999)》2004,36(2):755-757
The aim of this study performed in Abidjan, C?te d'Ivoire, was to describe the distribution of CD4+ T-cell lymphocytes (CD4) in HIV-1-infected (HIV+) pregnant women diagnosed during prenatal voluntary counseling and testing and to assess whether HIV-related immunodeficiency influenced the acceptance of an antiretroviral (ARV) package (zidovudine beginning at 36 weeks of amenorrhea plus intrapartum nevirapine) to prevent mother-to-child transmission. Between April and June 2002, a CD4 count was systematically performed in all HIV+ women (n=221) in 5 antenatal clinics carrying out voluntary counseling and testing. No difference in CD4 count was found in HIV+ women who did not return for their test result (n=50) and those who were informed of their positive serostatus (n=171) (median CD4 count: 389/mm3 vs. 420/mm3; P=0.19). We also found a lack of difference in CD4 count in those who accepted ARV (n=72) and those who did not but knew their HIV status (n=99) (median CD4 count: 405/mm3 vs. 425/mm3; P=0.47). The overall uptake of the intervention (31.9%) appeared to be independent of the maternal immune status. 相似文献
92.
Faller G Berndt R Borchard F Ell C Fuchs KH Geddert H Gossner L Günther T Kirchner T Koch HK Langner C Lüttges J May A Müller S Oberhuber G Seitz G Stolte M Tannapfel A Vieth M Walch A Rüschoff J;Working Group for Gastroenterological Pathology German Society for Pathology 《Der Pathologe》2003,24(1):9-14
There are a number of difficulties regarding the diagnosis of Barrett's mucosa and the varying grades of neoplasia that may be associated with it. It was therefore the aim of a consensus conference of the "Working Group for Gastroenterological Pathology within the German Society of Pathology" to achieve standardization regarding the following issues: definition and diagnostic criteria for Barrett's mucosa and its discrimination from intestinal metaplasia of the cardia, diagnostic criteria for intraepithelial neoplasia, number of biopsies necessary to establish the diagnosis, significance of additional immunohistochemical and/or molecular biological methods as well as importance of a second opinion in the diagnosis of intraepithelial neoplasia. 相似文献
93.
94.
95.
Race and the response to adrenergic blockade with carvedilol in patients with chronic heart failure 总被引:9,自引:0,他引:9
Yancy CW Fowler MB Colucci WS Gilbert EM Bristow MR Cohn JN Lukas MA Young ST Packer M;U.S. Carvedilol Heart Failure Study Group 《The New England journal of medicine》2001,344(18):1358-1365
BACKGROUND: The benefits of angiotensin-converting-enzyme inhibitors and beta-blockers may be smaller in black patients than in patients of other races, but it is unknown whether race influences the response to carvedilol in patients with chronic heart failure. METHODS: In the U.S. Carvedilol Heart Failure Trials Program, 217 black and 877 nonblack patients (in New York Heart Association class II, III, or IV and with a left ventricular ejection fraction of no more than 0.35) were randomly assigned to receive placebo or carvedilol (at doses of 6.25 to 50 mg twice daily) for up to 15 months. The effects of carvedilol on ejection fraction, clinical status, and major clinical events were retrospectively compared between black and nonblack patients. RESULTS: As compared with placebo, carvedilol lowered the risk of death from any cause or hospitalization for any reason by 48 percent in black patients and by 30 percent in nonblack patients. Carvedilol reduced the risk of worsening heart failure (heart failure leading to death, hospitalization, or a sustained increase in medication) by 54 percent in black patients and by 51 percent in nonblack patients. The ratios of the relative risks associated with carvedilol for these two outcome variables in black as compared with nonblack patients were 0.74 (95 percent confidence interval, 0.42 to 1.34) and 0.94 (95 percent confidence interval, 0.43 to 2.05), respectively. Carvedilol also improved functional class, ejection fraction, and the patients' and physicians' global assessments in both the black patients and the nonblack patients. For all these measures of outcome and clinical status, carvedilol was superior to placebo within each racial cohort (P<0.05 in all analyses), and there was no significant interaction between race and treatment (P> 0.05 in all analyses). CONCLUSIONS: The benefit of carvedilol was apparent and of similar magnitude in both black and nonblack patients with heart failure. 相似文献
96.
Lipid abnormalities in HIV-infected patients are not correlated with lopinavir plasma concentrations
97.
van Leth F Huisamen CB Badaro R Vandercam B de Wet J Montaner JS Hall DB Wit FW Lange JM;NN Study Group 《Journal of acquired immune deficiency syndromes (1999)》2005,38(3):296-300
BACKGROUND: The initial rate of plasma HIV-1 RNA (pVL) decline has been proposed as a marker of early efficacy of antiretroviral therapy (ART) and a possible predictor of late efficacy. We compared the rate of pVL decline in patients starting ART with nevirapine (NVP), efavirenz (EFV), or both drugs combined in addition to lamivudine (3TC) and stavudine (d4T). METHODS: Analysis of the viral decay constant (VDc) during the first 2 weeks of treatment in patients enrolled in the 2NN study who remained on allocated treatment. RESULTS: The median VDc (log10 copies per day, [interquartile range]) was similar for NVP (0.30 [0.25-0.36], EFV (0.31 [0.27-0.37]), and NVP + EFV (0.30 [0.27-0.36]). Patients with a baseline pVL >100,000 copies/mL were 8.7 (95% confidence interval [CI]: 6.2-12.3) times more likely to have a VDc >75th percentile. A high VDc was not associated with plasma drug concentration or with a decreased risk of virologic failure at week 48 after the start of therapy (hazard ratio = 0.8, 95% CI: 0.6-1.2). CONCLUSION: NVP, EFV, or NVP + EFV in combination with 3TC and d4T show similar rates of pVL decline during the first 2 weeks of treatment. The VDc with these regimens is not predictive of late virologic efficacy. 相似文献
98.
Balotta C Facchi G Violin M Van Dooren S Cozzi-Lepri A Forbici F Bertoli A Riva C Senese D Caramello P Carnevale G Rizzardini G Cremonini L Monno L Rezza G Perno CF Ippolito G d'Arminio-Monforte A Vandamme AM Moroni M;ICONA Study Group 《Journal of acquired immune deficiency syndromes (1999)》2001,27(5):499-505
99.
Guidelines for the validation and application of typing methods for use in bacterial epidemiology 总被引:3,自引:0,他引:3
A. van Belkum P. T. Tassios L. Dijkshoorn S. Haeggman B. Cookson N. K. Fry V. Fussing J. Green E. Feil P. Gerner-Smidt S. Brisse M. Struelens for the European Society of Clinical Microbiology Infectious Diseases Study Group on Epidemiological Markers 《Clinical microbiology and infection》2007,13(S3):1-46
100.
A. Stathi J. Papaparaskevas L. Zachariadou A. Pangalis N. J. Legakis A. Tseleni-Kotsovili the Hellenic Strep-EURO Study Group P. T. Tassios 《Clinical microbiology and infection》2008,14(8):808-812
Among a total of 101 isolates from the first systematic multicentre surveillance effort concerning invasive Streptococcus pyogenes disease in Greece, conducted between 2003 and 2005 and covering 38% of the population, emm types 1 and 12 were prevalent, being responsible for 27 and nine cases, respectively. The isolates from the remaining 65 cases were assigned to 26 other emm types. Erythromycin resistance (12 isolates) was primarily mef (A)-mediated, although all emm type 1 strains were susceptible. Tetracycline resistance, due mostly to tet (M), was detected in 26 isolates. Subtyping by pulsed-field gel electrophoresis yielded 50 chromosomal fingerprints, thus discriminating further among ten of the 28 observed emm types. 相似文献