全文获取类型
收费全文 | 1609篇 |
免费 | 86篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 97篇 |
妇产科学 | 118篇 |
基础医学 | 134篇 |
口腔科学 | 42篇 |
临床医学 | 165篇 |
内科学 | 322篇 |
皮肤病学 | 45篇 |
神经病学 | 34篇 |
特种医学 | 146篇 |
外科学 | 115篇 |
综合类 | 136篇 |
预防医学 | 135篇 |
眼科学 | 10篇 |
药学 | 90篇 |
1篇 | |
中国医学 | 74篇 |
肿瘤学 | 35篇 |
出版年
2021年 | 17篇 |
2020年 | 11篇 |
2018年 | 15篇 |
2017年 | 19篇 |
2016年 | 14篇 |
2015年 | 38篇 |
2014年 | 44篇 |
2013年 | 45篇 |
2012年 | 56篇 |
2011年 | 54篇 |
2010年 | 56篇 |
2009年 | 44篇 |
2008年 | 45篇 |
2007年 | 39篇 |
2006年 | 45篇 |
2005年 | 20篇 |
2004年 | 25篇 |
2003年 | 19篇 |
2002年 | 12篇 |
2001年 | 22篇 |
2000年 | 12篇 |
1999年 | 25篇 |
1998年 | 44篇 |
1997年 | 55篇 |
1996年 | 47篇 |
1995年 | 42篇 |
1994年 | 57篇 |
1993年 | 35篇 |
1992年 | 15篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 28篇 |
1988年 | 27篇 |
1987年 | 30篇 |
1986年 | 25篇 |
1985年 | 16篇 |
1984年 | 16篇 |
1983年 | 16篇 |
1982年 | 13篇 |
1981年 | 23篇 |
1980年 | 16篇 |
1959年 | 35篇 |
1958年 | 58篇 |
1957年 | 87篇 |
1956年 | 45篇 |
1955年 | 75篇 |
1954年 | 67篇 |
1953年 | 17篇 |
1952年 | 14篇 |
1949年 | 10篇 |
排序方式: 共有1708条查询结果,搜索用时 15 毫秒
991.
992.
993.
Background
HIV physicians have limited time for cognitive screening. Here we developed an extra‐brief, clinically based tool for predicting HIV‐associated neurocognitive impairment (HAND) in order to determine which HIV‐positive individuals require a more comprehensive neurological/neuropsychological (NP) assessment.Methods
Ninety‐seven HIV‐positive individuals with advanced disease recruited in an HIV out‐patient clinic received standard NP testing. A screening algorithm was developed using support vector machines, an optimized prediction procedure for classifying individuals into two groups (here NP‐impaired and NP‐normal) based on a set of predictors.Results
The final algorithm utilized age, current CD4 cell count, past central nervous system HIV‐related diseases and current treatment duration and required approximately 3 min to complete, with a good overall prediction accuracy of 78% (against the gold standard; NP‐impairment status derived from standard NP testing) and a good specificity of 70%.Conclusion
This noncognitive‐based algorithm should prove useful to identify HIV‐infected patients with advanced disease at high risk of HAND who require more formal assessment. We propose staged guidelines, using the algorithm, for improved HAND therapeutic management. Future larger, international studies are planned to test the predictive effect of nadir CD4 cell count, hepatitis C virus infection, gender, ethnicity and HIV viral clade. We recommend the use of this first version for HIV‐infected Caucasian men with advanced disease. 相似文献994.
子宫内膜异位症(EM)中异位内膜的生长和侵袭依赖于性激素,而性激素与其受体结合后才能起作用.该文综述了雌、孕激素受体的结构、功能、基因、亚型及其在在位、异位内膜中的表达,并探讨其在EM的发生、发展以及治疗和预后中的作用. 相似文献
995.
细胞外基质(ECM)主要分布于细胞外空间,包括胶原蛋白、非胶原蛋白和蛋白多糖三大类,在与其特殊黏附受体结合后,连接构成复杂的网架结构,起到调节组织发生和细胞生理活动的作用.层粘连蛋白(LN)、纤维粘连蛋白(FN)作为ECM的重要组成成分,广泛存在于各种动植物的细胞表面、细胞外液、结缔组织以及多数基底膜中.不仅在支持、连接和维持组织形态方面起重要作用,而且具有调节细胞黏附、生长、分化、促进细胞迁移、增殖、离子交换和信息传递的功能.对LN和FN的分子结构、合成分布及在胚胎着床、发育过程中表达与作用进行综述. 相似文献
996.
INTRODUCTION
By December 2008, 90% of referrals requiring hospital admission will need to be seen and treated within the 18-week patient pathway. Previously, patients within our trust with suspected carpal tunnel syndrome had to wait 3 months to see a specialist in clinic and, once assessed, would have to wait up to a further 6 months for an open carpal tunnel decompression under local anaesthetic (OCTD/LA). We set up a one-stop clinic, where patients would have their out-patient consultation and surgery on the same day. We evaluated the clinic in order to assess whether it led to reduced waiting times whilst maintaining good clinical outcome and patient satisfaction.PATIENTS AND METHODS
Patients were selected on the basis of the standard referral letter alone. Those selected were then assessed by a single surgeon in the clinic. The patients deemed appropriate underwent an OCTD/LA and were discharged the same day. Patients were followed up with a patient satisfaction and Boston questionnaire.RESULTS
Forty-six patients underwent 63 OCTD/LA, waiting an average of 2.2 months (9 weeks) from referral. There was high patient satisfaction and improvement in symptoms following treatment in the clinic.CONCLUSIONS
We believe a one-stop carpal tunnel clinic can be an efficient and cost-effective way of treating this common condition. 相似文献997.
目的:研究桑叶多糖对实验性2型糖尿病(T2DM)模型大鼠糖代谢及脂代谢的影响。方法:大鼠高糖高脂饲料喂养4周后,腹腔注射30mg·kg^-1链脲佐菌素(STZ),建立T2DM大鼠模型,随机分为糖尿病模型对照组、桑叶多糖低剂量组(灌胃180mg·kg^-1·d^-1)、中剂量组(灌胃360mg·kg^-1·d^-1)、高剂量组(灌胃540mg·kg^-1·d^-1)及罗格列酮治疗组(灌胃4mg·kg·d^-1)。持续灌胃给药60d后测空腹血糖(FBG)、血脂、糖化血红蛋白(HbAlc)、胰岛素(Ins)的含量。结果:桑叶多糖可降低T2DM模型大鼠的FBG、HbAlc、总胆固醇(TCH)、甘油三酯(TG)及低密度脂蛋白(LDL)水平,提高高密度脂蛋白(HDL)和Ins水平,与模型组比较有明显改善(P〈0.05),与罗格列酮药物治疗组无显著性差异(P〉0.05)。结论:桑叶多糖能有效地降低T2DM模型大鼠的血糖,促进胰岛素(Ins)分泌.纠正糖尿病大鼠脂代谢紊乱.调节血脂。 相似文献
998.
目的 研究抗肿瘤药顺铂(cisplatin,Pt)对Wnt通路抑制因子FrpHE(frizzled relatd protein)和 DKK-1(dickkopf-1)表达的调节作用.方法 培养人肝癌HepG2、Hep3B、人大肠癌Lovo和人神经胶质瘤U251细胞,并分别加入5 μmol/L Pt作用24 h,以RT PCR技术检测FrpHE和DKK-1mRNA,以流式细胞术检测肿瘤细胞中Wnt通路的关键调节因子β-catenin的表达.结果 顺铂作用24 h后,FrpHE mRNA表达水平在人肝癌细胞较对照组表达水平显著增加(P<0.001).在人大肠癌细胞和人神经胶质瘤细胞中,未见FrpHE mRNA表达.DKK 1mRNA表达水平在加入Pt作用后的人肝癌细胞、人大肠癌细胞和人神经胶质瘤细胞均较对照组表达水平显著增加.β-catenin的阳性细胞百分比和平均荧光强度与对照组相比均降低(P<0.001).结论 化疗药顺铂能够诱导肝癌细胞FrpHE mRNA和人肝癌、肠癌、神经胶质瘤细胞DKK-1 mRNA的表达,抑制Wnt通路. 相似文献
999.
FABIO CAPASSO ANNA GIUNTA† GIUSEPPE STABILE PIETRO TURCO VINCENZO LA ROCCA GABRIELLA GRIMALDI ANTONIO DE SIMONE 《Pacing and clinical electrophysiology : PACE》2005,28(S1):S1-S4
Cardiac resynchronization therapy (CRT) improves myocardial performance in patients with heart failure (HF) and left bundle-branch block (LBBB). Tissue Doppler echocardiography (TDE) has already been used to guide the selection of candidates for CRT. The objective of this study is to correlate the effects of CRT on left ventricular (LV) systolic function with wall motion synchrony assessed by TDE. High frame TDE data were obtained in 15 patients (mean age = 68.9 years, 11 men) with LBBB (QRS = 163 ± 13 ms) to derive temporal intraventricular horizontal asynchrony indexes, expressed as the time difference at the onset of shortening between the septum and the lateral (S-L) and antero-inferior (A-I) walls, and measure the amount of delayed longitudinal contraction (DLC) within the LV. All measurements were made at baseline, 24 hours after implantation, and at 1 year of follow-up. The results show that LV ejection fraction (EF) increased from 25 ± 6.2% at baseline to 36.9 ± 7.9% at 1 year, and was strongly related to DLC, expressed either by time duration (DLCd, r =−0.51; P < 0.0001) or percent of the basal segments (%DLC, r =−0.50; P < 0.001). New York Heart Association functional class, which decreased from 3.6 ± 0.5 to 2.3 ± 0.8, was correlated with %DLC (r = 0.50) and DLCd (r = 0.48, P < 0.001). Weaker correlations were found between LVEF and S-Li (r =−0.40) and between NYHA and S-Li (r = 0.40). It is concluded that DLC was the best among intraventricular asynchrony indexes in predicting increases in LVEF after CRT. DLC may be useful to identify responders to CRT. 相似文献
1000.