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   6621篇
  免费   347篇
  国内免费   122篇
耳鼻咽喉   28篇
儿科学   131篇
妇产科学   69篇
基础医学   530篇
口腔科学   436篇
临床医学   507篇
内科学   1016篇
皮肤病学   73篇
神经病学   82篇
特种医学   208篇
外科学   2273篇
综合类   998篇
预防医学   215篇
眼科学   29篇
药学   340篇
  3篇
中国医学   77篇
肿瘤学   75篇
  2024年   59篇
  2023年   151篇
  2022年   169篇
  2021年   296篇
  2020年   274篇
  2019年   209篇
  2018年   231篇
  2017年   194篇
  2016年   179篇
  2015年   214篇
  2014年   384篇
  2013年   433篇
  2012年   294篇
  2011年   353篇
  2010年   325篇
  2009年   320篇
  2008年   314篇
  2007年   330篇
  2006年   285篇
  2005年   271篇
  2004年   245篇
  2003年   228篇
  2002年   189篇
  2001年   172篇
  2000年   129篇
  1999年   93篇
  1998年   80篇
  1997年   73篇
  1996年   69篇
  1995年   64篇
  1994年   54篇
  1993年   55篇
  1992年   46篇
  1991年   42篇
  1990年   37篇
  1989年   35篇
  1988年   31篇
  1987年   23篇
  1986年   30篇
  1985年   14篇
  1984年   18篇
  1983年   7篇
  1982年   12篇
  1981年   12篇
  1980年   5篇
  1979年   6篇
  1978年   14篇
  1977年   8篇
  1976年   5篇
  1975年   4篇
排序方式: 共有7090条查询结果,搜索用时 0 毫秒
61.
Background: Ischemic heart disease is the major cause of death inpatients with end-stage renal disease. The high prevalence of coronary artery disease results in a rising number of dialysis patients requiring myocardial revascularisation. Objective: The objective of this study was to compare the outcomes of recurrent angina, myocardial infarction, rate of reinterventions and cardiovascular death following percutaneous coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) inpatients with end-stage renal disease. Patients and methods: In a retrospective investigation 40 patients with chronic renal failure undergoing primarily PTCA and 65 patients undergoing CABG were included. Both groups were comparable for gender, duration on dialysis and the number of cardiovascular risk factors per patient. Patients undergoing PTCA were younger (53 ± 12 years vs. 57 ± 8 years; p < 0.05) and more often diabetics (30% vs. 14%; p < 0.05). Results: Most patients in both groups had a multi-vessel disease (95% in the CABG group vs. 74% in the PTCA group), in the CABG group there were significantly more patients with a triple-vessel disease (62% with vs. 40%in the PTCA group; p < 0.01), PTCA was primarily successful in 95% of the patients while complete revascularization was achieved in 88% of patients undergoing CABG. The perioperative mortality after CABG was 4.8% as compared to none after interventional revascularisation. The cumulative freedom of angina after 6, 12 and 24 months after intervention was significantly lower after PTCA (54%, 40%, 29%) than after bypass grafting (97%, 94%, 90%, p < 0.001). The frequency of reinterventions following PTCA was significantly higher compared to patients following CABG (p < 0.001). After PTCA 15 patients needed further revascularisations, 8 of them underwent CABG, whereas after CABG only two patients required additional myocardial revascularisation. There was no significant difference in the overall mortality between both groups; the survival rate after 12 and 24 months was 95% and 82% after PTCA and 93% and 86% after CABG, respectively. Condition: Although patients receiving CABG had a more severe coronary artery disease the overall mortality was comparable and clinical and functional outcome was improved compared to patients after coronary angioplasty. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
62.
This study was conducted to evaluate the vascular relaxant effects of toborinone on canine internal mammary ring preparations. We determined the concentration–contraction curves for various vasoconstrictors, namely norepinephrine, serotonin, U46619, endothelin-1, phenylephrine, and KCl in internal mammary artery (IMA) preparations, then assessed the vascular relaxant effects of the test drugs. As models, preparations with and without functional endothelium were used. As vasorelaxants, we used milrinone, papaverine, and nitroglycerin. Toborinone produced concentration-dependent relaxation in preparations precontracted with norepinephrine and serotonin. However, the vascular relaxant effect of toborinone on KCl-induced contraction was weaker than those on norepinephrine- and serotonin-induced contraction. Toborinone produced concentration-dependent relaxation in preparations with, and those without functional endothelium. There was no difference in the potency between the preparations with, and those without functional endothelium. The relaxing effect of toborinone on norepinephrine-induced contraction (EC50 = 1.3 × 10−6 M) was significantly weaker than that of nitroglycerin (EC50 = 7.8 × 10−8 M), equal to that of papaverine (EC50 = 2.2 × 10−6 M), and significantly stronger than that of milrinone (EC50 = 3.3 × 10−6 M). These results demonstrate that toborinone produces relaxant effects on canine IMA preparations, and that it may be effective in the treatment of IMA malperfusion syndrome. Received: December 7, 2000 / Accepted: May 15, 2001  相似文献   
63.
目的探讨外科手术对心肌桥的治疗效果。方法1999年1月~2006年10月,我院对15例心肌桥(13例有典型心绞痛,经正规药物治疗,症状控制不佳,1例急性心肌梗死,1例心悸、晕厥)行手术治疗,其中9例行非体外循环不停跳手术(3例单纯心肌桥切开松解术,2例单纯冠状动脉搭桥术,4例心肌桥切开松解术联合冠状动脉搭桥术),6例行体外循环下手术(5例心肌桥切开松解术联合冠状动脉搭桥术,1例单纯心肌桥切开松解术)。结果15例手术均取得成功,非体外循环不停跳手术组手术时间(2.8±1.9)h;体外循环手术组手术时间(3.5±1.7)h,体外循环时间(59±37)min。无手术死亡及手术并发症,术后3个月心绞痛、心悸症状完全缓解,11例心电图恢复正常。15例随访0.5~7年,(1.9±1.2)年,1例复发心悸,其余患者无心绞痛复发。结论外科手术治疗心肌桥具有良好的近、中期效果。  相似文献   
64.
目的:探讨睾丸网腺癌的发病和临床特点,以做到早诊断、早治疗.方法:报告6例睾丸网腺癌患者的临床资料.6例均为左侧发病,术前均诊断为左侧附睾和睾丸炎,并继发性睾丸鞘膜积液;拟行患侧附睾切除加鞘膜翻转术.术中发现左睾丸质硬有肿物并侵及附睾,遂行睾丸、附睾切除术.结果:术后病理检查诊断为睾丸网腺癌侵及睾丸和附睾;6例术后均获随访.结论:睾丸网腺癌在临床表现独特,根治性睾丸切除辅以根治性腹膜后淋巴结清扫术效果满意,放疗和化疗效果欠佳.  相似文献   
65.
目的探讨应用普通股骨髓腔扩大绞刀代替专用的椎间植骨器械,进行腰椎后路椎间植骨融合术的临床经验体会,评估治疗效果。方法对我院34例应用股骨髓腔绞刀进行腰椎后路椎间植骨融合术的病例资料,进行回顾性分析。结果本组34例无围手术期硬膜及神经根损伤,无伤感染和和植骨块松脱。随访5~6年,植骨全部于6~8个月愈合,无一例植骨塌陷。按Machnab标准评定:优21例,良11例,可2例,差0例,优良率94.12%。结论改良应用股骨髓腔扩大绞刀代替专用的椎间植骨器械,作椎间植骨床的准备,效果满意,安全方便。  相似文献   
66.
目的 观察全麻复合胸段硬膜外阻滞对不停跳冠状动脉搭桥术(OPCABG)后患者T细胞亚群及止浆皮质醇的影响.方法 22例择期行OPCABG患者随机分为全麻组(A组)和全麻复合硬膜外阻滞组(E组),每组11例,术后均采用吗啡静脉镇痛(PCIA).分别于麻醉前(T1)、术毕(T2)、术后第1天(T3)及第3天(T4)抽取外周静脉血,用流式细胞仪(FCM)检测T淋巴细胞亚群变化,以化学发光法测血浆皮质醇.结果 与T1比较,两组血浆皮质醇在T2和T3均明显升高(P<0.05),但E组患者升高程度明显低于A组(P<0.05).两组T2和T3 CD3 、CD4 和CD4 /CD8 均较T1明显下降(P<0.05).但与E组比较,A组T3及T4 CD3 、CD4 、CD4 /CD8 下降更明显(P<0.05),且E组患者T淋巴细胞亚群在T4已恢复至T1水平(P>0.05).结论 全麻对OPCABG后患者细胞免疫功能有抑制作用,复合胸段硬膜外阻滞将减轻此抑制的程度.  相似文献   
67.
PURPOSE: Tissue-engineered tendon grafts will meet an important clinical need. To engineer tendons, we used acellularized allogeneic tendon as scaffold material. To determine the ideal cell type to seed the scaffolds, we studied in vitro characteristics of epitenon tenocytes, tendon sheath fibroblasts, bone marrow-derived mesenchymal stem cells (BMSCs), and adipoderived mesenchymal stem cells (ASCs). Subsequently, we implanted reseeded acellularized tendons in vivo as flexor tendon grafts. METHODS: Tenocytes, sheath fibroblasts, BMSCs, and ASCs were obtained from adult rabbits. For all cell lines, collagen 1, 2, and 3 immunocytochemistry was performed, and proliferation was assessed by hemacytometry and senescence by beta-galactosidase staining. Flexor tendons were acellularized after harvest. Tendons were assessed by histology after in vitro reseeding with each of the cell types after 1, 4, and 8 weeks. Finally, reseeded tendons and controls were implanted in a flexor profundus tendon defect. After 6 weeks, the reseeded tendons were harvested and assessed by histology. Statistical analysis for cell proliferation was performed using analysis of variance and t-tests with Bonferroni correction. RESULTS: All cell types had similar collagen expression. Cell proliferation was higher in ASCs in late passage compared with early passage and in ASCs compared with epitenon tenocytes at late passage. The other cell types were similar in growth characteristics. No senescence was detected. In vitro assessment of reseeded constructs showed the presence of cells on the construct surface. In vivo assessment after implantation showed viable cells seen within the tendon architecture in all cell types. CONCLUSIONS: This study suggests that the four cell types may be successfully used to engineer tendons. Adipoderived mesenchymal stem cells proliferate faster in cell culture, but the cell types were similar in other respects. All could be used to successfully repopulate acellularized tendon in vivo as flexor tendon grafts.  相似文献   
68.
The results of treatment of femoral head osteonecrosis with free vascularized fibular grafting (FVFG) following failed core decompression (core decompression-FVFG [CD-FVFG] group: 32 hips) were reviewed and compared with those of a control group that underwent FVFG only (54 hips). Outcome was considered unsuccessful if total hip arthroplasty was subsequently performed. Total hip arthroplasty was performed in 15 and 20 hips of the CD-FVFG and control groups, respectively. When considering age, sex, and presence of bilateral disease, patients with previous core decompression did not have a significantly different failure rate from patients with FVFG only. However, patients with preoperative stage V osteonecrosis or corticosteroid use had worse outcomes after vascularized fibular grafting if they had a previous core decompression of the femoral head.  相似文献   
69.
目的 探讨非体外循环下冠状动脉搭桥术(OPCABG)围术期输注地尔硫(艹卓)对心肌的保护作用.方法 40例择期手术患者,随机分为地尔硫(艹卓)组(D组)与硝酸甘油组(C组),每组20例.D组静脉给予地尔硫(艹卓)0.1 mg·kg-1·h-1至术后24 h,C组常规给予硝酸甘油0.1μg·kg-1·h-1至术后24 h.分别在术毕、术后1、3、6、12和24 h记录血流动力学参数,并采集血样测定血清肌钙蛋白Ⅰ(cTnI).结果 与C组比较,D组的心率术后1、3、6、12、24 h均较慢(P<0.05).C组房颤4例,D组1例;C组室上性心动过速5例,D组1例.术后6 h的cTnI,D组显著低于C组(P<0.05).结论 OPCABG围术期持续输注地尔硫(艹卓)有比硝酸甘油更好的抗缺血和抗心律失常的保护作用.  相似文献   
70.
目的:探讨自体脂肪移植修复面部凹陷性及萎缩性瘢痕的方法和临床疗效。方法:对10例面部凹陷性及萎缩性瘢痕患者采用自体脂肪移植进行治疗。脂肪获取、提纯及注射采用3M3L移植技术。每例自体脂肪移植1~3次,每次间隔3~6个月,综合评价患者术后面部轮廓畸形、瘢痕皮肤质地改善情况。结果:患者均获随访3个月~1年,无感染、囊肿、钙化、血管和神经损伤等并发症发生,也未产生新畸形及新瘢痕。轮廓凹陷畸形得到矫正,瘢痕皮肤质地及色泽有所改善,患者均对治疗效果满意。结论:自体脂肪移植是一种治疗面部凹陷性及萎缩性瘢痕可行的微创方法。  相似文献   
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