首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14771篇
  免费   1573篇
  国内免费   890篇
耳鼻咽喉   112篇
儿科学   123篇
妇产科学   180篇
基础医学   1692篇
口腔科学   277篇
临床医学   1890篇
内科学   2098篇
皮肤病学   119篇
神经病学   861篇
特种医学   607篇
外国民族医学   8篇
外科学   1549篇
综合类   2739篇
现状与发展   4篇
一般理论   1篇
预防医学   971篇
眼科学   338篇
药学   1553篇
  34篇
中国医学   939篇
肿瘤学   1139篇
  2025年   1篇
  2024年   207篇
  2023年   319篇
  2022年   668篇
  2021年   795篇
  2020年   648篇
  2019年   500篇
  2018年   536篇
  2017年   536篇
  2016年   452篇
  2015年   674篇
  2014年   832篇
  2013年   665篇
  2012年   1017篇
  2011年   1114篇
  2010年   704篇
  2009年   571篇
  2008年   706篇
  2007年   749篇
  2006年   740篇
  2005年   731篇
  2004年   519篇
  2003年   477篇
  2002年   439篇
  2001年   374篇
  2000年   364篇
  1999年   401篇
  1998年   251篇
  1997年   236篇
  1996年   179篇
  1995年   136篇
  1994年   142篇
  1993年   60篇
  1992年   86篇
  1991年   90篇
  1990年   84篇
  1989年   60篇
  1988年   41篇
  1987年   26篇
  1986年   32篇
  1985年   30篇
  1984年   13篇
  1983年   9篇
  1982年   7篇
  1981年   8篇
  1979年   4篇
  1942年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
The mortality of conservative treatment and the risk resulting from operation for elderly patients with femoral intertrochanteric fractures are high. Safety in the perioperative period and quicker recovery should be placed at the top priority for elderly patients with hip fractures. We reported a case of 109-year-old female patient with intertrochanteric fracture who has undergone the hemiarthroplasty in our center recently. With sciatic nerve and lateral cutaneous nerve block anesthesia, she was offered the artificial femoral head replacement in the lumbar plexus block after sufficient preoperative preparation. The surgery went well with minimally invasive cut, and the patient''s recovery was satisfactory.  相似文献   
102.
采用薄层色谱法对制剂中的大黄、赤芍进行了定性鉴别 ;用消化—配位滴定法对硫酸锌进行了含量测定 ,方法简便 ,专属性及重现性好 ,可作为该制剂的质量控制指标。  相似文献   
103.
INTRODUCTION: Bone marrow mesenchymal stem cells (MSCs) are ideal target cells for cell transplantation and tissue engineering. We investigated their biological characteristics and differentiation mediated by different methods. It is important to study the short-term fate of labeled allogeneic MSCs after subcutaneous implantation in rabbits in order to provide insights into the application of allogeneic MSCs for tissue regeneration. MATERIALS AND METHODS: Mesenchymal stem cells were labeled by two different methods in vitro and then were incubated with gelatin sponge. Autologous MSCs-Gelatin constructs and allogeneic MSCs-Gelatin constructs were subcutaneously implanted into 32 rabbits. The constructs were analyzed for the survival and migration of labeled MSCs at day 3, week 1, 3, and 5 post-implantation. RESULTS: EGFP was successfully expressed following transfection of MSCs with the retroviral vector pLEGFP-N1. In addition, EGFP-MSCs can be functionally induced into osteocytes, chondrocytes, and adipocytes in conditioned media. By weeks 3 after implantation, the labeled cells distributed extensively on the surface of gelatin sponge and gradually integrated into host tissues. EGFP-labeled MSCs were observed under fluorescence microscopy and BrdU-expressing cells were detected with immunohistochemical stain in allogeneic or autologous MSCs-Gelatin constructs during the initial five weeks after implantation. CONCLUSIONS: It is a simple and reliable way to trace the changes of MSCs in vivo by EGFP in cell transplantation and gene therapy. Allogeneic rabbit MSCs can survive for at least 5 weeks after subcutaneous implantation and maintain a strong ability of migration, indicating that allogeneic MSCs are of certain value in clinical application for temporary replacement.  相似文献   
104.
Multiple cell types infiltrate acutely rejecting renal allografts. Typically, monocytes and T cells predominate. Although T cells are known to be required for acute rejection, the degree to which monocytes influence this process remains incompletely defined. Specifically, it has not been established to what degree monocytes impact the clinical phenotype of rejection or how their influence compares to that of T cells. We therefore investigated the relative impact of T cells and monocytes by correlating their presence as measured by immunohistochemical staining with the magnitude of the acute change in renal function at the time of biopsy in 78 consecutive patients with histological acute rejection. We found that functional impairment was strongly associated with the degree of overall cellular infiltration as scored using Banff criteria. However, when cell types were considered, monocyte infiltration was quantitatively associated with renal dysfunction while T-cell infiltration was not. Similarly, renal tubular stress, as indicated by HLA-DR expression, increased with monocyte but not T-cell infiltration. These data suggest that acute allograft dysfunction is most closely related to monocyte infiltration and that isolated T-cell infiltration has less acute functional impact. This relationship may be useful in assigning acute clinical relevance to biopsy findings.  相似文献   
105.
目的探讨应用微骨折技术对全层关节软骨缺损修复的效果。方法20只大白兔随机分为两组,在其右股骨内髁先建立全层软骨缺损模型,实验组进行微骨折处理,对照组则不予特殊处理。分别在4周和8周各处死10只实验兔,作大体观察、病理学检查和修复组织厚度测量。临床上对68例全层关节软骨缺损进行随机分组:实验组35例,关节清理后应用微骨折技术进行处理;对照组33例,仅作关节清理术。结果对照组只有肉芽组织和瘢痕组织生长,仅边缘有少量软骨组织生长,实验组在4周时大部分为软骨组织生长,8周已全部被软骨组织修复。术后平均随访8.6个月,Lysholm评分实验组明显优于对照组。结论微骨折技术是一种有效的修复全层关节软骨缺损方法。  相似文献   
106.
目的:探讨膀胱肿瘤组织巾MMP-2及MMP-9表达与膀胱移行细胞癌(TCCB)临床病理分期分级的关系。方法:选择同济医院2004年1~12月间手术治疗的TCCB患者38例作为实验组,以16例附带癌旁正常黏膜或膀胱镜下活检正常膀胱黏膜作为对照组。运用免疫组织化学SP法检测MMP-2及MMP-9在膀胱组织中的表达。结果:MMP-2和MMP-9在实验组的表达显著高于对照组(P〈0.01),且与肿瘤临床分期呈显著正相关(r=0.51361,P〈0.01),与肿瘤病理分级也呈正相关(r=0.59818,P〈0.05)。结论:TCCB患者膀胱组织中高表达的MMP-2及MMP-9与肿瘤细胞侵袭和转移密切相关,联合检测MMP-2及MMP-9,对TCCB的早期诊断及判断预后有参考价值。  相似文献   
107.
Recent studies confirmed that the new cell survival signal pathway of Insulin-PI3K-Akt exerted cyto-protective actions involving anti-apoptosis. This study was undertaken to investigate the potential neuroprotective effects of insulin in the pathogenesis of spinal cord injury (SCI) and evaluate its therapeutic effects in adult rats. SCI was produced by extradural compression using modified Allen's stall with damage energy of 40 g-cm force. One group of rats was subjected to SCI in combination with the administration of recombinant human insulin dissolved in 50% glucose solution at the dose of 1 IU/kg day, for 7 days. At the same time, another group of rats was subjected to SCI in combination with the administration of an equal volume of sterile saline solution. Functional recovery was evaluated using open-field walking, inclined plane tests, and motor evoked potentials (MEPs) during the first 14 days post-trauma. Levels of protein for B-cell lymphoma/leukemia-2 gene (Bcl-2), Caspase-3, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were quantified in the injured spinal cord by Western blot analysis. Neuronal apoptosis was detected by TUNEL, and spinal cord blood flow (SCBF) was measured by laser-Doppler flowmetry (LDF). Ultimately, the data established the effectiveness of insulin treatment in improving neurologic recovery, increasing the expression of anti-apoptotic bcl-2 proteins, inhibiting caspase-3 expression decreasing neuronal apoptosis, reducing the expression of proinflammatory cytokines iNOS and COX-2, and ameliorating microcirculation of injured spinal cord after moderate contusive SCI in rats. In sum, this study reported the beneficial effects of insulin in the treatment of SCI, with the suggestion that insulin should be considered as a potential therapeutic agent.  相似文献   
108.
目的:探讨经腹膜外途径腹腔镜下前列腺癌根治术(ELRP)的手术方法和临床效果。方法:对2011年6月~2014年2月行ELRP术29例患者的临床资料进行回顾性分析:患者年龄60~77岁,平均68岁。所有患者均于术前行前列腺穿刺活组织检查或前列腺电切术后经病理检查证实为前列腺癌,术前总PSA平均18.9μg/L,其中4.0μg/L者2例,4~20μg/L者16例,20μg/L者11例。均行ELRP。结果:手术时间60~330min,平均125min;术中出血量80~1 200ml,平均150ml;术中输血2例。1例因阴茎背静脉复合体出血中转开放手术。术中直肠损伤1例。术后病理检查均证实为前列腺癌,Gleason评分6~9分,切缘阳性3例。术后留置导尿管时间12~26d,平均15d。拔除尿管后出现轻度尿失禁8例,术后1~3个月均可满意控尿。术后3个月检查血清PSA为0~0.18μg/L,未发现肿瘤局部生化复发和远处转移。结论:ELRP创伤小,并发症少,患者恢复快,是治疗局限性前列腺癌安全有效的手术方法。  相似文献   
109.
目的:研究TUEB剜除电极下经尿道等离子前列腺剜除术(TUEP)的安全性及有效性。方法:收集2011年5月~2011年9月我院因中、重度下尿路症状诊断为前列腺增生(BPH)具备手术指征,行TUEB剜除电极下的TUEP术的56例患者的临床资料。监测术前经腹超声前列腺重量,血清前列腺特异抗原(PSA);术中出血量,前列腺切除率,术后血红蛋白,血钠浓度,血葡萄糖浓度;术前、术后1个月及3个月的国际前列腺症状评分(IPSS),生活质量评分(QOL),最大尿流率(Qmax),剩余尿量(RUV)(经腹超声)及术后并发症发生率等指标。结果:43例患者完成3个月随访,前列腺切除率(64.18±7.54)%,单位时间切除量(0.89±0.36)g,患者无电切综合征及包膜穿孔,血糖、血钠浓度手术前后差异无统计学意义。术后1个月IPSS评分、QOL评分、Qmax及RUV较术前显著好转。术后1个月及术后3个月上述指标差异无统计学意义。术后短暂性尿失禁发生率7.14%,恢复时间(4.50±1.29)d,无永久性尿失禁,术后1个月尿道狭窄发生率16.07%,尿道扩张后均缓解。结论:TUEB剜除电极下TUEP术是安全有效的手术方法。  相似文献   
110.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号