全文获取类型
收费全文 | 3993篇 |
免费 | 260篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 181篇 |
妇产科学 | 63篇 |
基础医学 | 356篇 |
口腔科学 | 99篇 |
临床医学 | 464篇 |
内科学 | 762篇 |
皮肤病学 | 169篇 |
神经病学 | 242篇 |
特种医学 | 343篇 |
外国民族医学 | 3篇 |
外科学 | 463篇 |
综合类 | 259篇 |
一般理论 | 10篇 |
预防医学 | 318篇 |
眼科学 | 136篇 |
药学 | 200篇 |
2篇 | |
中国医学 | 32篇 |
肿瘤学 | 145篇 |
出版年
2022年 | 39篇 |
2021年 | 56篇 |
2020年 | 45篇 |
2019年 | 32篇 |
2018年 | 45篇 |
2017年 | 41篇 |
2016年 | 48篇 |
2015年 | 65篇 |
2014年 | 89篇 |
2013年 | 126篇 |
2012年 | 169篇 |
2011年 | 180篇 |
2010年 | 129篇 |
2009年 | 151篇 |
2008年 | 142篇 |
2007年 | 168篇 |
2006年 | 165篇 |
2005年 | 128篇 |
2004年 | 132篇 |
2003年 | 123篇 |
2002年 | 103篇 |
2001年 | 101篇 |
2000年 | 95篇 |
1999年 | 77篇 |
1998年 | 104篇 |
1997年 | 83篇 |
1996年 | 95篇 |
1995年 | 77篇 |
1994年 | 52篇 |
1993年 | 57篇 |
1992年 | 59篇 |
1991年 | 59篇 |
1990年 | 63篇 |
1989年 | 68篇 |
1988年 | 75篇 |
1987年 | 63篇 |
1986年 | 75篇 |
1985年 | 69篇 |
1984年 | 46篇 |
1983年 | 48篇 |
1979年 | 31篇 |
1978年 | 34篇 |
1977年 | 42篇 |
1976年 | 38篇 |
1973年 | 33篇 |
1972年 | 31篇 |
1958年 | 29篇 |
1956年 | 30篇 |
1955年 | 42篇 |
1954年 | 35篇 |
排序方式: 共有4300条查询结果,搜索用时 31 毫秒
41.
42.
氯化镧对内毒素诱导巨噬细胞肿瘤坏死因子表达的影响 总被引:1,自引:1,他引:1
目的 探讨稀土化合物氯化镧对内毒素效应的影响。 方法 分离培养小鼠腹腔巨噬细胞 (M) ,用内毒素 (lipopolysaccharide ,LPS)对其进行诱导实验。采用ELISA法及SYBRGreen荧光定量RT PCR方法 ,观察氯化镧对LPS诱导的小鼠M肿瘤坏死因子α(TNFα)分泌及TNFαmRNA表达的影响。BALB/C小鼠随机分为 2组 ,分别给予致死量LPS及经氯化镧处理的LPS ,观察 7d内小鼠死亡率。 结果 经氯化镧处理的LPS诱导的小鼠 ,MTNFα分泌量及TNFαmRNA表达水平均明显低于LPS组 (P <0 .0 1)。经氯化镧处理的致死量LPS攻击小鼠 ,其死亡率明显低于LPS对照组。 结论 氯化镧具有降低内毒素毒性、抑制LPS诱导小鼠MTNFα分泌及TNFαmRNA表达的作用 相似文献
43.
目的对内膜修整后所取得的内膜组织按妊娠结果的不同分组进行分子水平的分析和检测,寻找合适的内膜发育分子标志物,早期预测辅助生殖技术(ART)患者的妊娠结果。方法随机选择10例接受增殖期子宫内膜修整术患者,其B超及组织学检查结果表明内膜处于相同发育阶段,按妊娠结果分为妊娠组与未妊娠组,抽提每例的子宫内膜组织总RNA,4例妊娠患者和3例未妊娠患者的内膜组织RNA符合芯片检测要求,使用Affymetrix U133 plus 2.0基因芯片进行表达谱分析。结果妊娠组与未妊娠组子宫内膜组织具有218个差异表达基因(≥2倍),其中177个基因在未妊娠组高表达,41个基因在妊娠组高表达。差异基因主要涉及代谢、细胞通讯和胞内过程调控等生物学过程,参与离子结合、信号传导和物质转运等重要功能。结论妊娠组与未妊娠组的增殖期子宫内膜细胞表达在转录组水平上差异明显,某些重要差异表达基因(LAMA4i、ntegrinα6和MMP1)有可能成为便利的早期预测ART患者妊娠结果的分子标志物。 相似文献
44.
Stephen R. Thom MD PhD Tatyana N. Milovanova MD PhD Ming Yang MD Veena M. Bhopale PhD Elena M. Sorokina PhD Günalp Uzun MD D. Scot Malay DPM MSCE Michael A. Troiano DPM Kevin R. Hardy MD David S. Lambert MD Christopher J. Logue MD David J. Margolis MD PhD 《Wound repair and regeneration》2011,19(2):149-161
Diabetic patients undergoing hyperbaric oxygen therapies (HBO2T) for refractory lower extremity neuropathic ulcers exhibit more than a twofold elevation (p=0.004) in circulating stem cells after treatments and the post‐HBO2T CD34+ cell population contains two‐ to threefold higher levels of hypoxia inducible factors‐1, ‐2, and ‐3, as well as thioredoxin‐1 (p<0.003), than cells present in blood before HBO2T. Skin margins obtained from 2‐day‐old abdominal wounds exhibit higher expression of CD133, CD34, hypoxia inducible factor‐1, and Trx‐1 vs. margins from refractory lower extremity wounds and expression of these proteins in all wounds is increased due to HBO2T (p<0.003). HBO2T is known to mobilize bone marrow stem cells by stimulating nitric oxide synthase. We found that nitric oxide synthase activity is acutely increased in patients' platelets following HBO2T and remains elevated for at least 20 hours. We conclude that HBO2T stimulates vasculogenic stem cell mobilization from bone marrow of diabetics and more cells are recruited to skin wounds. 相似文献
45.
目的探讨采用二期膀胱黏膜半管状重建尿道术治疗后型尿道下裂的临床研究。方法81例后型尿道下裂病例采用二期手术:一期手术将阴茎海绵体完全伸直,阴茎包皮内板和背侧皮肤预置于阴茎腹侧;二期手术采用半管状阴茎阴囊皮肤+半管状膀胱黏膜成形尿道术。结果81例后型尿道下裂患者矫形后形态几乎接近正常。手术成功率为86.4%(70/81),尿瘘发生率为13.6%(11/81),8例(9.9%,8/81)发生尿道狭窄,经尿道扩张治疗后痊愈。结论二期膀胱黏膜半管状重建尿道术治疗后型尿道下裂的手术成功率较高,值得临床推荐。 相似文献
46.
目的:探讨阴茎手术对勃起功能的影响并评估术后长期小剂量使用伐地那非对勃起功能的恢复作用。方法:选择阴茎手术患者共60例,随机分为两组:伐地那非治疗组和对照组,每组30例。治疗组术后5~7 d开始服用伐地那非10 mg,隔日1次,持续12周;对照组口服维生素E 100 mg,每日1次,持续12周。IIEF-5问卷评估术前和用药后3个月、6个月勃起功能改变。结果:治疗组术前IIEF-5评分为(14.21±3.62)分,术后3、6个月IIEF-5评分[(18.83±2.98)分,(20.13±2.98)分]较手术前提高,差异均有显著性(P均<0.05);而对照组患者术后3个月勃起功能下降,IIEF-5评分(13.38±2.82)分较术前(15.80±3.02)分降低,差异有显著性(P>0.05)。治疗组术后IIEF-5评分较对照组高(P<0.05)。结论:阴茎手术后小剂量长期服用伐地那非有助于恢复和保持阴茎的勃起功能。 相似文献
47.
Song Y Manson JE Tinker L Rifai N Cook NR Hu FB Hotamisligil GS Ridker PM Rodriguez BL Margolis KL Oberman A Liu S 《Diabetes》2007,56(7):1898-1904
Elevated circulating levels of soluble adhesion molecules as markers of endothelial dysfunction have been related to insulin resistance and its associated metabolic abnormalities. However, their associations with type 2 diabetes remain inconclusive. We conducted a prospective nested case-control study to examine the associations between plasma levels of E-selectin, intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) and diabetes risk among 82,069 initially healthy women aged 50-79 years from the Women's Health Initiative Observational Study. During a median follow-up of 5.9 years, 1,584 incident diabetes case subjects were matched with 2,198 control subjects by age, ethnicity, clinical center, time of blood draw, and follow-up time. Baseline median levels of the biomarkers were each significantly higher among case subjects than among control subjects (E-selectin, 49 vs. 37 ng/ml; ICAM-1, 324 vs. 280 ng/ml; and VCAM-1, 765 vs. 696 ng/ml [all P values <0.001]). After adjustment for risk factors, the relative risks of diabetes among women in the highest quartile versus those in the lowest quartile were 3.46 for E-selectin (95% CI 2.56-4.68; P for trend <0.0001), 2.34 for ICAM-1 (1.75-3.13; P for trend <0.0001), and 1.48 for VCAM-1 (1.07-2.04; P for trend = 0.009). E-selectin and ICAM-1 remain significant in each ethnic group. In conclusion, higher levels of E-selectin and ICAM-1 were consistently associated with increased diabetes risk in a multiethnic cohort of U.S. postmenopausal women, implicating an etiological role of endothelial dysfunction in the pathogenesis of type 2 diabetes. 相似文献
48.
49.
Philip Peng FRCPC Manon Choiniere PhD Dominique Dion MD MSc Howard Intrater FRCPC Sandra LeFort PhD Mary Lynch FRCPC May Ong FRCPC Saifee Rashiq MSc DA FRCPC Gregg Tkachuk PhD Yves Veillette FRCPC 《Journal canadien d'anesthésie》2007,54(12):977-984
PURPOSE: The objective of this survey was to examine the services offered by multidisciplinary pain treatment facilities (MPTFs) across Canada and to compare access to care at these MPTFs. METHODS: A MPTF was defined as a clinic that advertised specialized multidisciplinary services for the diagnosis and management of patients with chronic pain, having a minimum of three different health care disciplines (including at least one medical speciality) available and integrated within the facility. The search method included approaching all hospital and rehabilitation centre administrators in Canada, the Insurance Bureau of Canada, the Workplace Safety and Insurance Board or similar body in each province. Designated investigators were responsible for confirming and supplementing MPTFs from the preliminary list for each province. Administrative leads at each eligible MPTF were asked to complete a detailed questionnaire regarding their MPTF infrastructure, clinical, research, teaching and administrative activities. RESULTS: Completed survey forms were received from 102 MPTFs (response rate 85%) with 80% concentrated in major cities, and none in Prince Edward Island and the Territories. The MPTFs offer a wide variety of treatments including non-pharmacological modalities such as interventional, physical and psychological therapy. The median wait time for a first appointment in public MPTFs is six months, which is approximately 12 times longer than non-public MPTFs. Eighteen pain fellowship programs exist in Canadian MPTFs and 64% engage in some form of research activities CONCLUSION: Canadian MPTFs are unable to meet clinical demands of patients suffering from chronic pain, both in terms of regional accessibility and reasonable wait time for patients' first appointment. 相似文献
50.
Recent advances in multiparametric magnetic resonance imaging (MRI) have enabled image-guided detection of prostate cancer. Fusion of MRI with real-time ultrasound (US) allows the information from MRI to be used to direct biopsy needles under US guidance in an office-based procedure. Fusion can be performed either cognitively or electronically, using a fusion device. Fusion devices allow superimposition (coregistration) of stored MRI images on real-time US images; areas of suspicion found on MRI can then serve as targets during US-guided biopsy. Currently available fusion devices use a variety of technologies to perform coregistration: robotic tracking via a mechanical arm with built-in encoders (Artemis/Eigen, BioJet/Geoscan); electromagnetic tracking (UroNav/Philips-Invivo, Hi-RVS/Hitachi); or tracking with a 3D US probe (Urostation/Koelis). Targeted fusion biopsy has been shown to identify more clinically significant cancers and fewer insignificant cancers than conventional biopsy. Fusion biopsy appears to be a major advancement over conventional biopsy because it allows (1) direct targeting of suspicious areas not seen on US and (2) follow-up biopsy of specific cancerous sites in men undergoing active surveillance. 相似文献