全文获取类型
收费全文 | 105929篇 |
免费 | 11030篇 |
国内免费 | 6871篇 |
专业分类
耳鼻咽喉 | 860篇 |
儿科学 | 1897篇 |
妇产科学 | 1186篇 |
基础医学 | 9821篇 |
口腔科学 | 1565篇 |
临床医学 | 15068篇 |
内科学 | 12459篇 |
皮肤病学 | 1073篇 |
神经病学 | 4262篇 |
特种医学 | 3467篇 |
外国民族医学 | 29篇 |
外科学 | 7635篇 |
综合类 | 22834篇 |
现状与发展 | 27篇 |
一般理论 | 4篇 |
预防医学 | 10283篇 |
眼科学 | 2668篇 |
药学 | 12831篇 |
187篇 | |
中国医学 | 8779篇 |
肿瘤学 | 6895篇 |
出版年
2024年 | 461篇 |
2023年 | 1687篇 |
2022年 | 4207篇 |
2021年 | 5347篇 |
2020年 | 4374篇 |
2019年 | 3276篇 |
2018年 | 3276篇 |
2017年 | 3600篇 |
2016年 | 3224篇 |
2015年 | 4900篇 |
2014年 | 6161篇 |
2013年 | 6495篇 |
2012年 | 9152篇 |
2011年 | 9877篇 |
2010年 | 7344篇 |
2009年 | 6255篇 |
2008年 | 6981篇 |
2007年 | 6711篇 |
2006年 | 6121篇 |
2005年 | 5238篇 |
2004年 | 3618篇 |
2003年 | 3250篇 |
2002年 | 2594篇 |
2001年 | 2032篇 |
2000年 | 1714篇 |
1999年 | 1333篇 |
1998年 | 710篇 |
1997年 | 726篇 |
1996年 | 583篇 |
1995年 | 509篇 |
1994年 | 479篇 |
1993年 | 277篇 |
1992年 | 237篇 |
1991年 | 196篇 |
1990年 | 192篇 |
1989年 | 159篇 |
1988年 | 139篇 |
1987年 | 120篇 |
1986年 | 91篇 |
1985年 | 57篇 |
1984年 | 27篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 19篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1977年 | 6篇 |
1974年 | 5篇 |
1972年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
142.
143.
A spot weld & heating treatment tri-uses device based on modern mechanical-electric technique, was developed for dental spot weld, stainless steel orthodontic wire heating-reversion and Ni-Ti orthodontic wire heating-overload metamorphism. The device will be very helpful instrument in orthodontic clinic. The paper not only described the operating methods of the device, but also discussed the Performance-improved principles of stainless steel orthodontic wire and the principles of heating overload metamorphism of Ni-Ti orthodontic wire. 相似文献
144.
Sertraline and fluoxetine have different pharmacologic and pharmacokinetic profiles which may be of clinical relevance in the determination of response in different subtypes of depression. A randomized, double-blind, 6-week study comparing sertraline (50-100 mg/day) with fluoxetine (20-40 mg/day) in 286 outpatients with major depression, who had demonstrated comparable efficacy and tolerability for the two drugs, was analysed by subgroups of patients at baseline with melancholia, severe depression, single depressive episode, multiple depressive episodes, high anxiety, low anxiety, psychomotor retardation and psychomotor agitation. Multiple logistic regression with regressors including treatment-by-subgroup variables revealed that, within certain subgroups, the efficacy might differ substantially from that of the whole treatment group. However, the only treatment-by-subgroup interaction term that was significant was anxiety (P < 0.05). There was no evidence of interaction in single or recurrent episode subgroups, and these were not included in subsequent analyses. Subsequent two-sample statistical comparison tests of response (i.e. Hamilton Depression Scale reduction > or = 50%) rates at study endpoint between treatment groups demonstrated that patients with melancholic depression and those with symptoms of psychomotor agitation yielded a significantly greater proportion of responders with sertraline compared to fluoxetine (P < 0.05). Response rates in sertraline- and fluoxetine-treated patients, respectively, were: overall study 59%, 51%; melancholia 59%, 44%; severe depression 59%, 41%; low anxiety 71%, 55%; high anxiety 47%, 48%; psychomotor retardation, 48%, 46%; and psychomotor agitation 62%, 39%. Multiple logistic regression adjusting for possible confounding factors, that included a treatment by anxiety interaction term, also led to similar findings. In particular, the analysis showed that significant differences existed in favour of sertraline in patients with low anxiety in the melancholia and severe depression subgroups (P < 0.05), indicating that these characteristics predicted a superior response to 6 weeks of treatment with sertraline relative to fluoxetine. Sertraline also demonstrated advantages over fluoxetine on parameters such as sleep and weight disturbance in severely depressed patients, and sleep disturbance, weight, cognitive disturbance and retardation in melancholic patients. 相似文献
145.
药流与负压吸宫法的效果和可接受性研究 总被引:5,自引:1,他引:4
研究的目的:比较RU486/Cytotec药物和负压吸宫术两种流产方法的效果,以及医学的和个人的可接受性.对象为通过咨询,介绍两种流产方法后,让对象自愿选择而组成.年龄在20~34岁.药物组100例,闭经35~42天,第1天口服RU486 600mg,第3天服Cytotec(PGE1)0.4mg,第17、43天回医院随访.手术组100例,闭经≤56天,负压吸宫术后第14、43天回医院随访.结果:完全流产率药物组为89%,手术组为100%.对象选择这两种流产方法的主要原因:药物组94%的人认为痛苦少,手术组的55%认为手术快、节省时间,而且手术同时可取出或放置宫内节育器(占45%).结论:RU486/Cytotec药物流产和负压吸宫术在各自适合的人群中都具有高度的可接受性.两种方法各具优缺点,不能相互取代,二者相辅相成,取长补短,将使终止妊娠的措施更为安全 相似文献
146.
Influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. 总被引:21,自引:4,他引:17 下载免费PDF全文
V A Varney Q A Hamid M Gaga S Ying M Jacobson A J Frew A B Kay S R Durham 《The Journal of clinical investigation》1993,92(2):644-651
We have studied the influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. In a double-blind, placebo-controlled trial of immunotherapy in 40 adult hay fever sufferers, clinical improvement was accompanied by a decrease in the size of the late-phase skin response. When the immunotherapy-treated group was compared with the placebo group, analysis of skin biopsies obtained 24 h after intradermal allergen revealed a significant reduction in the number of infiltrating CD3+ (P = 0.04) and CD4+ (P = 0.009) cells and a trend for a decrease in EG2+ eosinophils (P = 0.08). Treatment did not influence allergen-induced recruitment of CD8+ cells, neutrophils, or macrophages. Unexpected increases in expression of CD25 (P = 0.006) and HLA-DR (P = 0.007) were observed in the actively treated group. In situ hybridization using a panel of riboprobes demonstrated "TH2-type" (IL-4, IL-5) cytokine mRNA responses in both groups of patients. In contrast, significant hybridization for IL-2 (8/16 patients, P = 0.02) and for interferon-gamma (6/16 patients, P = 0.04) was observed only in the actively treated group. These findings indicate that immunotherapy is associated with suppression of allergen-induced CD4+ T lymphocyte infiltration, but among the cells that are recruited, there is upregulation of CD25 and HLA-DR. At least in this model, immunotherapy does not appear to affect expression of TH2-pattern cytokines in response to allergen exposure, but expression of mRNA for Th1-type cytokines was enhanced in half of the patients. The results support the view that immunotherapy may possibly be working through induction of T cell tolerance. 相似文献
147.
电针对去势大鼠外周血淋巴细胞雌激素受体影响的研究 总被引:4,自引:0,他引:4
目的 从生殖内分泌 -免疫网络角度探讨电针治疗围绝经期综合征的作用机制。方法 以去势大鼠为实验对象 ,取双侧三阴交、太溪、后三里穴 ,采用放射免疫法和流式细胞分析技术 ,观察电针治疗对去势大鼠血清雌激素 (E2 )、促黄体生成素 (LH)、促卵泡生成素(FSH)及外周血淋巴细胞内雌激素受体 (ER)水平的影响。结果 电针可使去势大鼠血清E2 明显升高 ,LH及FSH明显下降 ,外周血淋巴细胞内ER明显升高 ,与造模组比较有显著性差异。结论 电针可明显改善去势大鼠的生殖内分泌功能 ,并能调节免疫细胞的雌激素受体表达。 相似文献
148.
辨证分期治疗慢性盆腔炎合并免疫性不孕症18例疗效观察 总被引:1,自引:0,他引:1
目的:探讨辨证分期治疗慢性盆腔炎合并免疫性不孕症的临床疗效。方法:选择慢性盆腔炎合并免疫性不孕症(血清抗精子抗体阳性)患者18例,采用辨证分期治疗。月经干净后,治以活血化瘀、理气祛湿为主;在(或相当于)排卵期或排卵后,治以补肾养血,活血化瘀为主;在经前期,治以理气活血调经为主;在月经干净后至经前期,加用小剂量阿司匹林。结果:盆腔炎临床症状及体征痊愈7例,显效6例,有效5例;全部患者获得妊娠,宫内妊娠者17例(观察至妊娠3月,均正常),输卵管妊娠1例;结论:中医辨病辨证结合的周期疗法加小剂量阿司匹林治疗慢性盆腔灸合并免疫性不孕症有一定的疗效。 相似文献
149.
药敏纸片的质量控制研究 总被引:1,自引:0,他引:1
目的:探讨和研究药敏纸片质量控制的方法。方法:以克拉霉素药敏纸片为例,参照美国临床实验室标准化委员会(NCCLS)和联邦法规全书(CFR)的方法,建立一套药敏纸片质量控制的指标,包括鉴别、检查及含量测定。结果:采用专属性较强、灵敏度较高的TLC法进行鉴别,最低检出量为50μg;制订纸片的的直径、重量差异、含量均匀性及干燥失重作为检查项,采用短小芽孢杆菌(Bacillus pumilus)[CMCC(B)63202]作为检定菌,进行含量测定。结论:建立的克拉霉素药敏纸片质量标准能够控制其质量,可作为其他抗生素药敏纸片建立质量标准的参考。 相似文献
150.
Shuzhi Yang Lingxiang Li Jun Han Haiyan Chen Wei Zhang Erzhong Fan Ying Li 《临床耳鼻咽喉头颈外科杂志》2003,17(6):336-338
OBJECTIVE: To explore the expression of TGF-beta 1/T beta R II in laryngeal carcinoma. METHOD: Immunohistochemical study using SP kit in 53 cases. RESULT: The expression of TGF-beta 1 was decreased in carcinoma tissues when compared with peri-cancer controls (P < 0.05). There wasn't difference in T beta R II expression when compared with peri cancer controls (P > 0.05). But it was correlated with the stage, differentiation and lymph node metastasis of laryngeal carcinoma. CONCLUSION: TGF-beta 1/T beta R II may involve in the histogenesis and development of laryngeal carcinoma. The decreased expression of TGF-beta 1/T beta R II may serve as an important molecular marker of laryngeal carcinoma. 相似文献