全文获取类型
收费全文 | 57277篇 |
免费 | 4672篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 516篇 |
儿科学 | 1530篇 |
妇产科学 | 1092篇 |
基础医学 | 7573篇 |
口腔科学 | 958篇 |
临床医学 | 6381篇 |
内科学 | 10909篇 |
皮肤病学 | 812篇 |
神经病学 | 4909篇 |
特种医学 | 2240篇 |
外科学 | 9529篇 |
综合类 | 800篇 |
一般理论 | 57篇 |
预防医学 | 5679篇 |
眼科学 | 1423篇 |
药学 | 4094篇 |
1篇 | |
中国医学 | 54篇 |
肿瘤学 | 3550篇 |
出版年
2023年 | 323篇 |
2022年 | 465篇 |
2021年 | 1170篇 |
2020年 | 665篇 |
2019年 | 1105篇 |
2018年 | 1330篇 |
2017年 | 977篇 |
2016年 | 1049篇 |
2015年 | 1259篇 |
2014年 | 1831篇 |
2013年 | 2543篇 |
2012年 | 3886篇 |
2011年 | 3969篇 |
2010年 | 2148篇 |
2009年 | 1909篇 |
2008年 | 3456篇 |
2007年 | 3711篇 |
2006年 | 3586篇 |
2005年 | 3494篇 |
2004年 | 3232篇 |
2003年 | 3068篇 |
2002年 | 2885篇 |
2001年 | 915篇 |
2000年 | 867篇 |
1999年 | 854篇 |
1998年 | 651篇 |
1997年 | 523篇 |
1996年 | 495篇 |
1995年 | 520篇 |
1994年 | 436篇 |
1993年 | 406篇 |
1992年 | 558篇 |
1991年 | 499篇 |
1990年 | 517篇 |
1989年 | 477篇 |
1988年 | 438篇 |
1987年 | 386篇 |
1986年 | 391篇 |
1985年 | 436篇 |
1984年 | 375篇 |
1983年 | 308篇 |
1982年 | 258篇 |
1981年 | 235篇 |
1980年 | 218篇 |
1979年 | 252篇 |
1978年 | 238篇 |
1974年 | 215篇 |
1973年 | 199篇 |
1972年 | 197篇 |
1968年 | 187篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
21.
Kathleen Pierson Donald Addington Jean Addington Scott Patten 《Revue canadienne de psychiatrie》2006,51(11):715-718
OBJECTIVE: To assess whether pharmacokinetic drug interactions occur when sertraline is added to antipsychotic medications. METHOD: Forty-eight patients with remitted DSM-IV schizophrenia and comorbid major depression were randomized to placebo for 6 weeks or sertraline 50 mg for 4 weeks followed by sertraline 50 mg to 100 mg for 2 weeks for nonresponders. Treatment with the patients' usual antipsychotic continued. Weekly clinical outcome assessments occurred for 6 weeks, and serum samples for drug monitoring were collected at Weeks 1, 5, and 6. Serum concentrations of sertraline and antipsychotics were measured with standard assays. RESULTS: In both placebo- and sertraline-treated groups, most patients displayed minor fluctuations in antipsychotic serum levels over 6 weeks. There was no clinical evidence of drug interactions in the sertraline-treated group. CONCLUSIONS: Clinically significant adverse effects did not occur despite variable antipsychotic serum levels with or without sertraline. Concern about pharmacokinetic interactions should not deter the use of sertraline for depression in individuals with schizophrenia. 相似文献
22.
AIMS: To establish all-cause and cause-specific death rates, and risk factors for mortality in insulin-treated diabetic individuals living in the province of Canterbury, New Zealand. METHODS: Insulin-treated diabetic subjects (n = 995) on the Canterbury Diabetes Registry were followed up over 15 years and vital status determined. Death rates were standardized and hazard regression was used to model the effects of demographic covariates on relative survival time. RESULTS: There were 419 deaths in 11 226.3 person-years of follow-up with a standardized mortality ratio (SMR) of 2.0 (95% confidence interval (CI) 1.8-2.2). Relative mortality was greatest for the group aged 0-29 years (SMR 3.0 (95% CI 2.4-3.7)). After controlling for diabetes duration and gender, a 10-year increment in age of onset was associated with a 33% decrease in relative hazard (95% CI 29-36%), indicating that excess mortality due to diabetes declines with rising age of onset. After controlling for age of onset and gender, each 10-year increment in duration of diabetes is associated with a 26% decrease in relative hazard (95% CI 24-29%), indicating that with longer survival the mortality hazard approaches the general population hazard. Relative mortalities were increased for cardiovascular, renal and respiratory disease, but not malignancy. Relative mortality from acute metabolic complications was increased in the subgroup with age of onset of diabetes < 30 years and requiring insulin within 1 year of diagnosis. CONCLUSIONS: Mortality rates are high for insulin-treated diabetic individuals relative to the general population. 相似文献
23.
Background
Hospital episode statistics (HES) is a UK national database for the National Health Service (NHS), now available online. The purpose of this study was to observe trends in ophthalmic operations performed during the period from 1998 to 2004, using this data. 相似文献24.
Matthew S Lewis Paul Maruff Brendan S Silbert Lis A Evered David A Scott 《Archives of clinical neuropsychology》2006,21(5):421-427
The reliable change index (RCI) expresses change relative to its associated error, and is useful in the identification of post-operative cognitive dysfunction (POCD). This paper examines four common RCIs that each account for error in different ways. Three rules incorporate a constant correction for practice effects and are contrasted with the standard RCI that had no correction for practice. These rules are applied to 160 patients undergoing coronary artery bypass graft (CABG) surgery who completed neuropsychological assessments preoperatively and 1 week post-operatively using error and reliability data from a comparable healthy non-surgical control group. The rules all identify POCD in a similar proportion of patients, but the use of the within subject standard deviation, expressing the effects of random error, as an error estimate is a theoretically appropriate denominator when a constant error correction, removing the effects of systematic error, is deducted from the numerator in a RCI. 相似文献
25.
26.
27.
28.
W J Scott C A Duggan C M Schreiner M D Collins 《Toxicology and applied pharmacology》1990,103(2):238-254
The effects of acetazolamide on the developing rodent limb bud were postulated to result from a reduction of intracellular pH (pHi). Embryonic intracellular pH was calculated from transplacental distribution of the weak acid, 5,5'-dimethyloxazolidine-2,4-dione, in teratogenically sensitive (C57BL/6) and resistant (SWV) inbred mice. pHi was reduced by acetazolamide treatment in C57 embryos and limb buds but not in SWV samples. Acetazolamide teratogenesis can be exacerbated by coadministration of amiloride, presumably through inhibition of Na+/H+ exchange attributable to the latter agent. pHi reduction after such treatment was more profound than after acetazolamide alone, providing further support for the central hypothesis. pH was also reduced in other embryonic (embryo plasma) and extraembryonic compartments (exocoelomic fluid, amniotic fluid). pH changes in these compartments could also lead or contribute to abnormal development. 相似文献
29.
C W Scott D P Blowers P T Barth M M Lo A I Salama C B Caputo 《Journal of neuroscience research》1991,30(1):154-162
Three isoforms of human tau protein were compared for their abilities to induce microtubule assembly. The three isoforms, tau 3 (tau containing three microtubule-binding domains), tau 4 (tau containing four microtubule-binding domains) and tau 4L (tau containing four microtubule binding domains plus a 58-amino-acid insert near the N-terminus) were expressed in E. coli and purified using ammonium sulfate precipitation, ion exchange, and size exclusion chromatography. All three isoforms induced microtubule assembly at micromolar concentrations and showed similar critical concentrations for assembly of 0.4-0.45 microM. However, tau 4 induced microtubule formation at a rate five- to tenfold faster than either tau 3 or tau 4L. The rate of microtubule elongation seen with tau 4 was twofold greater than with tau 3 or tau 4L, suggesting that the faster rate of microtubule assembly seen with tau 4 was due, at least in part, to faster elongation. Tau 4 induced a greater number of microtubules to form at steady state than did tau 3 or tau 4L. The microtubules generated with each tau isoform had similar steady-state length distributions and were equally susceptible to cold-induced disassembly. These results indicate that the additional microtubule-binding domain in tau 4 enhances microtubule assembly, while the 58-amino-acid insert negates the stimulatory effect of the fourth microtubule-binding domain. 相似文献
30.