全文获取类型
收费全文 | 18438篇 |
免费 | 1406篇 |
国内免费 | 42篇 |
专业分类
耳鼻咽喉 | 170篇 |
儿科学 | 484篇 |
妇产科学 | 327篇 |
基础医学 | 2441篇 |
口腔科学 | 657篇 |
临床医学 | 1824篇 |
内科学 | 4264篇 |
皮肤病学 | 186篇 |
神经病学 | 1743篇 |
特种医学 | 717篇 |
外国民族医学 | 1篇 |
外科学 | 2254篇 |
综合类 | 387篇 |
一般理论 | 16篇 |
预防医学 | 1539篇 |
眼科学 | 516篇 |
药学 | 1306篇 |
中国医学 | 10篇 |
肿瘤学 | 1044篇 |
出版年
2023年 | 68篇 |
2022年 | 92篇 |
2021年 | 248篇 |
2020年 | 141篇 |
2019年 | 245篇 |
2018年 | 278篇 |
2017年 | 231篇 |
2016年 | 254篇 |
2015年 | 303篇 |
2014年 | 434篇 |
2013年 | 772篇 |
2012年 | 1024篇 |
2011年 | 1097篇 |
2010年 | 583篇 |
2009年 | 601篇 |
2008年 | 1100篇 |
2007年 | 1205篇 |
2006年 | 1226篇 |
2005年 | 1215篇 |
2004年 | 1134篇 |
2003年 | 1095篇 |
2002年 | 1104篇 |
2001年 | 267篇 |
2000年 | 251篇 |
1999年 | 254篇 |
1998年 | 276篇 |
1997年 | 245篇 |
1996年 | 216篇 |
1995年 | 226篇 |
1994年 | 185篇 |
1993年 | 172篇 |
1992年 | 195篇 |
1991年 | 169篇 |
1990年 | 194篇 |
1989年 | 152篇 |
1988年 | 188篇 |
1987年 | 180篇 |
1986年 | 159篇 |
1985年 | 171篇 |
1984年 | 163篇 |
1983年 | 146篇 |
1982年 | 196篇 |
1981年 | 197篇 |
1980年 | 152篇 |
1979年 | 129篇 |
1978年 | 99篇 |
1977年 | 81篇 |
1976年 | 72篇 |
1975年 | 69篇 |
1974年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
103.
104.
105.
Effect of Postnatal Ethanol Exposure on Expression of Differentiation Antigens of Murine Splenic Lymphocytes 总被引:1,自引:0,他引:1
Pamela K. Giberson Barry R. Blakley 《Alcoholism, clinical and experimental research》1994,18(1):21-28
Ethanol is a recognized immunosuppressive agent in the chronic alcoholic. However, the effects of ethanol exposure on the developing immune system have not been extensively investigated. This study evaluated the effects of early postnatal ethanol exposure, via breast milk, on splenic lymphocyte differentiation antigen expression in offspring reared by ethanol-fed mice. Maternal mice were fed a liquid diet containing 20% ethanol-derived calories during pregnancy (E-P), pregnancy and lactation (E-PL), or lactation (E-L). Ad libitumfed (C) and pair-fed (PF) control groups, fed a control liquid diet, were included. Expression of differentiation antigens on splenic lymphocytes from 21-day-old offspring reared by females in 1 of the 3 ethanol exposure conditions was evaluated by flow cytometry. Offspring reared by E-P females had similar numbers of splenic lymphocytes as offspring reared by C and pair-fed during pregnancy (PF-P) females. In contrast, offspring reared by E-PL and E-L females had fewer splenic lymphocytes than both PF-PL and PF-L (respectively), and C offspring. The number of Thy 1.2+, CD4+, CD8+, and IgG+ (B-cell) splenic lymphocytes was reduced in E-PL and E-L offspring compared with PF and C offspring. E-P offspring had fewer CD4+ and IgG+ splenic lymphocytes than C, but not PF-P, offspring. The percentage of Thy 1.2+ splenic lymphocytes was significantly reduced among E-PL and E-L offspring compared with PF-PL and PF-L (respectively), and C offspring. These results suggest that ethanol exposure of female mice during pregnancy, pregnancy and lactation, or lactation alone, alters the phenotypic development of splenic lymphocytes of offspring reared by these females. The greatest effect on differentiation antigen expression occurred when females consumed ethanol during the period of lactation. We speculate that direct exposure of the nursing offspring to ethanol via the breast milk was responsible for the reductions in specific splenic lymphocyte populations. These data demonstrate that mice reared by females fed ethanol during the early postnatal period have a marked depletion of each of the major subpopulations of splenic lymphocytes, and that Thy 1.2+ lymphocytes are differentially sensitive to ethanol. 相似文献
106.
James J. Kuhlman Barry Levine Rolley E. Johnson Paul J. Fudala Edward J. Cone 《Addiction (Abingdon, England)》1998,93(4):549-559
Aims. Examine the relationship between buprenorphine and norbuprenorphine plasma concentrations with subject-reported withdrawalsymptomatology during buprenorphine dose induction, maintenance treatment (daily and alternate-day dosing) and withdrawal . Design. Two groups of randomly assigned subjects inducted onto buprenorphine and maintained on 8 mg daily by the sublingual route for 18 days. Group 1 continued to receive daily buprenorphine to day 36. Group 2 subjects received alternate-day dosing of buprenorphine and placebo on days 19 to 36. Both groups received placebo on days 37 to 52 . Setting. Inpatient facilities at the Addiction Research Center, Intramural Research Center, NIDA, Baltimore, MD . Participants. Eleven male, heroin-dependent volunteers participating in a research study . Intervention. Medications for treatment of withdrawal symptoms were prescribed as needed after day 39 (72 hours after the last dose of buprenorphine) . Measurements. Plasma concentrations of buprenorphine and norbuprenorphine, withdrawal symptomatology and pupil diameter . Findings. The mean steady-state buprenorphine plasma concentration (24 hours) after daily administration of sublingual buprenorphine for study days 21-35 was 0.80 ng/ml, and the mean alternate day steady-state buprenorphine plasma concentration (24 hours) was 0.77 ng/ml. Daily and alternate day steady-state norbuprenorphine plasma concentrations were 1.10 and 0.90 ng/ml, respectively. Predicted alternate day steady-state buprenorphine and norbuprenorphine plasma concentrations at 48 hours were 0.49 ng/ml and 0.57 ng/ml, respectively. Withdrawal scores varied inversely with plasma concentration. There were no significant differences between Groups 1 and 2 during steady-state (days 21-35) with regard to withdrawal scale scores or pupillary diameter. The overall, mean terminal elimination half-lives for buprenorphine and norbuprenorphine were 42 and 57 hours, respectively . Conclusions. During daily buprenorphine maintenance, plasma concentrations greater than 0.7 ng/ml of buprenorphine and norbuprenorphine were associated with minimal withdrawal symptoms. The long elimination half-life of buprenorphine suggested that increasing the buprenorphine dose with alternate-day administration may provide an effective, flexible therapy regimen for the treatment of opioid dependence. 相似文献
107.
108.
Barry L. Carter Pharm.D. FCCP Debra J. Barnette Pharm.D. Elizabeth Chrischilles Ph.D. Gordon J. Mazzotti B.S. Ziad J. Asali M.D. 《Pharmacotherapy》1997,17(6):1274-1285
We evaluated blood pressure control, quality of life, quality of care, and satisfaction of patients who were monitored by specially trained community pharmacists in a group medical practice. After participating in an intensive skill development program, pharmacists performed in an interdisciplinary team in a rural clinic. The primary objective was assessed by evaluating outcome variables at 6 months compared with baseline in 25 patients randomly assigned to a study group. A control group of 26 patients was also evaluated to determine if outcome variables remained constant from baseline to 6 months. Systolic blood pressure was reduced in the study group (151 mm Hg baseline, 140 mm Hg at 6 mo, p<0.001) and diastolic blood pressure was significantly lower at 2, 4, and 5 months compared with baseline. Ratings from a blinded peer review panel indicated significant improvement in the appropriateness of the blood pressure regimen, going from 8.7 ± 4.7 to 10.9 ± 4.5 in the study group (p<0.01), but they did not change in the control group. Several quality of life scores improved significantly in the study group after 6 months (p<0.05). These included physical functioning (61.6 vs 70.7), physical role limitations (56.8 vs 72.8), and bodily pain (60.0 vs 71.7) at baseline and 6 months, respectively. There were no significant changes in the control group. Patient satisfaction scores were consistently higher in the study group at the end of the study. Our results indicate that when community pharmacists in a clinic setting are trained and included as members of the primary care team, significant improvements in blood pressure control, quality of life, and patient satisfaction can be achieved. 相似文献
109.
110.
Kenneth C. Chu Barry A. Miller Eric J. Feuer Benjamin F. Hankey 《Journal of clinical epidemiology》1994,47(12):1451-1461
U.S. cancer mortality data derived from information recorded on death certificates are frequently relied upon as an indicator of progress against cancer. A limitation of this measure is the lack of information pertaining to the onset of disease, such as year-of-diagnosis, age-at-diagnosis, stage of disease at diagnosis and histology of lesions. However, population-based cancer registries collect these types of data and allow the calculation of an incidence-file based mortality rate. This incidence-based mortality rate allows a partitioning of mortality by variables associated with the cancer onset. Breast cancer incidence-based mortality measures are created and compared to mortality rates based on death certificates over a comparable time period. Novel mortality measures, such as mortality rates by stage-at-diagnosis, age-at-diagnosis and year-of-diagnosis, are used to illustrate the value of this approach. 相似文献