全文获取类型
收费全文 | 87387篇 |
免费 | 10519篇 |
国内免费 | 4816篇 |
专业分类
耳鼻咽喉 | 962篇 |
儿科学 | 1613篇 |
妇产科学 | 742篇 |
基础医学 | 5155篇 |
口腔科学 | 1968篇 |
临床医学 | 11623篇 |
内科学 | 9015篇 |
皮肤病学 | 1264篇 |
神经病学 | 2385篇 |
特种医学 | 3695篇 |
外科学 | 7768篇 |
综合类 | 21623篇 |
现状与发展 | 13篇 |
一般理论 | 1篇 |
预防医学 | 11638篇 |
眼科学 | 1038篇 |
药学 | 9102篇 |
117篇 | |
中国医学 | 8431篇 |
肿瘤学 | 4569篇 |
出版年
2024年 | 481篇 |
2023年 | 1429篇 |
2022年 | 2780篇 |
2021年 | 3551篇 |
2020年 | 3272篇 |
2019年 | 1703篇 |
2018年 | 2230篇 |
2017年 | 2789篇 |
2016年 | 2301篇 |
2015年 | 3852篇 |
2014年 | 4779篇 |
2013年 | 6173篇 |
2012年 | 7647篇 |
2011年 | 7966篇 |
2010年 | 7334篇 |
2009年 | 6714篇 |
2008年 | 6421篇 |
2007年 | 6164篇 |
2006年 | 5418篇 |
2005年 | 4271篇 |
2004年 | 3006篇 |
2003年 | 2449篇 |
2002年 | 1967篇 |
2001年 | 1859篇 |
2000年 | 1279篇 |
1999年 | 666篇 |
1998年 | 426篇 |
1997年 | 436篇 |
1996年 | 429篇 |
1995年 | 343篇 |
1994年 | 276篇 |
1993年 | 257篇 |
1992年 | 188篇 |
1991年 | 162篇 |
1990年 | 144篇 |
1989年 | 167篇 |
1988年 | 141篇 |
1987年 | 144篇 |
1986年 | 121篇 |
1985年 | 123篇 |
1984年 | 93篇 |
1983年 | 90篇 |
1982年 | 69篇 |
1981年 | 74篇 |
1980年 | 53篇 |
1979年 | 38篇 |
1978年 | 34篇 |
1977年 | 40篇 |
1976年 | 39篇 |
1971年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
Malcolm P. Cutchin MA James C. Norton PhD Mae Marie Quan MSEd David Bolt MA Sarah Hughes BSN Barry Lindeman MBA 《The Journal of rural health》1994,10(4):273-278
An important aspect of primary care physician availability is the retention of physicians once they have located. While retention has been under-researched compared to recruitment, it is especially important in rural areas where physician shortages already exist. This study reports the results of a retention survey completed by 132 primary care physicians in rural eastern Kentucky. The survey sets up an objective, hypothetical retention scenario and asks physicians to respond to structured questions and to an open-ended question about factors not appearing in the survey. In response to the structured portion of the survey, physicians indicate that relief coverage is the most important factor in rural physician retention. A content analysis of 75 open-ended responses reveals that besides the other factors in the survey, "sociocultural integration" is the pre-eminent retention issue for rural practitioners. This article concludes that the role of the local rural community may be more important in retention than in recruitment. Finally, it is suggested that additional in-depth qualitative research be conducted within the local contexts to enhance the understanding of rural physician retention processes. 相似文献
942.
Scott H. Fettner S. Pai V. Batra G.-R. Zhu T. Kosoglou C. R. Banfield 《European journal of clinical pharmacology》1995,48(5):351-359
SCH 42354, a neutral metalloendopeptidase (NEP) inhibitor, is the pharmacologically active form of the prodrug SCH 42495. It exerts antihypertensive effects by potentiating atrial natriuretic peptide (ANP) activity through inhibition of its hydrolysis by NEP. The objective of this study was to characterize the pharmacokinetics (PK) and pharmacodynamics (PD) of SCH 42354 in hypertensive males. SCH 42495 12.5 to 400 mg was administered orally to hypertensive men twice daily in a double-blind, placebo controlled multiple-dose parallel group design. Plasma SCH 42354 concentration and diastolic blood pressure (DBP) data were used to develop a PK-PD model using two approaches. In the first (non-integrated) approach, the link model was used to predict effect-site concentrations, and was applied to data obtained at the 300 and 400 mg BID doses only; data at the other (lower) doses were not amenable to modeling because of high variability. Effect-site concentration and DBP data were then fit to a sigmoid Emax PD model. For the 300 mg BID dose, PD parameters were: maximum effect (Emax), 8.1mmHg; no-drug effect (Eo), 3.6 mmHg; concentration corresponding to 50% of maximum response (EC50), 0.87 g·ml–1; and gamma, 3.9. In the second (time-integrated) approach, plasma SCH 42354 concentration and effect data obtained over the entire dose range were integrated with respect to time. Average plasma concentration and DBP data were then fit to a simple Emax PD model. PD parameters obtained over the dose range were: Emax, 10.3 mmHg; Eo, 2.0 mmHg; and EC50, 0.7 g·ml–1. These were similar to the estimates obtained from the first approach, demonstrating that the integrated (average) data allow PK-PD modeling over the (entire) dose range. The analysis showed that, at steady-state, a 400 mg BID dose of SCH 42495 produced an approximate 10 mmHg decrease in DBP in hypertensive males; the average plasma SCH 42354 concentration attained at this dose was approximately 1.8 g·ml–1. 相似文献
943.
944.
945.
Usha Sambamoorthi PhD Stephen Crystal PhD Rizie Kumar MA Jeff Harman PhD 《Women's health issues》1999,9(6):286-294
Research Objectives: To develop population-based estimates of estrogen replacement therapy use rates in 1995 among women over age 65 living in the community; to estimate the impact of socioeconomic and health characteristics on estrogen use. Method: Estimates are based on a large, nationally representative sample of Medicare beneficiaries; detailed self-report data were merged with Medicare claims. Results: Overall, 13.1% of women reported use of estrogen replacement therapy in 1995. Estrogen users were more likely to be white, age 65–74, with private insurance, high income, history of osteoporosis and heart problems, no history of breast cancer, and a patient of gynecologists. Conclusions: Estrogen use was substantially lower among the socioeconomically disadvantaged, controlling for medical history variables, suggesting considerable inequity in access to estrogen replacement therapy treatment. 相似文献
946.
947.
Tracy Roberts BSc MPhil RGN Stirling Bryan BSc MSc Chris Heginbotham BSc MSc MA & Alison McCallum MB ChB MSc FFPHM 《Health expectations》1999,2(4):235-244
Background Public involvement in health care decision making and priority setting in the UK is being promoted by recent policy initiatives. In 1993, the British Medical Association called for public consultation where rationing of services was to be undertaken. The approach to priority setting advocated by many health economists is the maximization of quality adjusted life years (QALYs). Typically, for a particular health care programme, the QALY calculation takes account of four features: (1) the number of patients receiving the programme, (2) the survival gain, (3) the gain in quality of life and, (4) the probability of treatment success. Only one feature, that relating to quality of life, is based upon public preferences. If the QALY is to be used as a tool for health care resource allocation at a societal level then it should incorporate broader societal preferences.
Methods This study used an interview-based survey of 91 members of the general public to explore whether the traditional QALY maximization model is a good predictor of public responses to health care priority setting choices.
Results and conclusions Many respondents did not choose consistently in line with a QALY maximization objective and were most influenced by quality of life concerns. There was little support for health care programmes that provided a prognostic improvement but left patients in relatively poor states of health. The level of respondent engagement in the survey exercise was not sensitive to the provision of supporting clinical information. 相似文献
Methods This study used an interview-based survey of 91 members of the general public to explore whether the traditional QALY maximization model is a good predictor of public responses to health care priority setting choices.
Results and conclusions Many respondents did not choose consistently in line with a QALY maximization objective and were most influenced by quality of life concerns. There was little support for health care programmes that provided a prognostic improvement but left patients in relatively poor states of health. The level of respondent engagement in the survey exercise was not sensitive to the provision of supporting clinical information. 相似文献
948.
获得纯化的由大肠杆菌表达的小鼠 Fas配体(Fas ligand,FasL)。方法:以质粒 pET-15b为载体,在大肠杆菌BL21(DE3)中表达小鼠的FasL,用金属螫合亲和层析法纯化。结果:转化菌中,重组质粒是稳定的,异丙基-β-D硫代半乳糖苷可诱导小鼠FasL的表达 ,金属螫合亲和层析法可以初步纯化此蛋白。结论:在大肠杆菌中表达出小鼠的FasL,并得到初步纯化。 相似文献
949.
目的 比较常规疗法伍用增免灵与单用常规疗法对活动性肺结核的疗效及外周血T 淋巴细胞亚群的影响。方法 抽取常规化疗组(61 例)、常规化疗加增免灵组(72 例) 及健康对照组(35 例) 患者外周血,用APAAP法测定外周血淋巴细胞亚群。结果 活动性肺结核患者外周血CD+3 及CD+4 百分率及CD+4 /CD+8 比值显著低于健康对照组( P< 0.05) ,CD+8 高于健康对照组。结论 短程化疗伍用增免灵可显著改善活动性肺结核的疗效及细胞免疫状况。 相似文献
950.
Cytomegalovirus infection of the colon is a late and severe complication in human immunodeficiency virus patients. Despite availability of medical treatment, occasional life-saving emergency surgery must be performed. The controversial surgical aspects of treatment are discussed based upon an unusual case of aseptic generalized peritonitis without perforation. The feasibility and value of limited resection are emphasized. 相似文献