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   64860篇
  免费   6103篇
  国内免费   3443篇
耳鼻咽喉   941篇
儿科学   898篇
妇产科学   827篇
基础医学   8628篇
口腔科学   1292篇
临床医学   7703篇
内科学   10618篇
皮肤病学   1122篇
神经病学   3991篇
特种医学   3142篇
外国民族医学   32篇
外科学   7251篇
综合类   7512篇
现状与发展   14篇
一般理论   6篇
预防医学   3700篇
眼科学   1605篇
药学   6466篇
  45篇
中国医学   2817篇
肿瘤学   5796篇
  2024年   156篇
  2023年   873篇
  2022年   1819篇
  2021年   3463篇
  2020年   2537篇
  2019年   2344篇
  2018年   2386篇
  2017年   2146篇
  2016年   2176篇
  2015年   3106篇
  2014年   3597篇
  2013年   3583篇
  2012年   5146篇
  2011年   5323篇
  2010年   3416篇
  2009年   2700篇
  2008年   3546篇
  2007年   3539篇
  2006年   3269篇
  2005年   3025篇
  2004年   2288篇
  2003年   2094篇
  2002年   1749篇
  2001年   1380篇
  2000年   1364篇
  1999年   1323篇
  1998年   709篇
  1997年   688篇
  1996年   547篇
  1995年   474篇
  1994年   432篇
  1993年   257篇
  1992年   449篇
  1991年   336篇
  1990年   336篇
  1989年   290篇
  1988年   252篇
  1987年   210篇
  1986年   190篇
  1985年   150篇
  1984年   106篇
  1983年   77篇
  1982年   45篇
  1981年   47篇
  1979年   49篇
  1977年   35篇
  1976年   41篇
  1975年   32篇
  1974年   50篇
  1972年   35篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的:探讨布一加综合征的诊治经验。方法:回顾分析本院自1993年-2002年,采用超声介入及手术方法治疗48例布加综合征的疗法结果。超声引导下支架术治疗布一加综合征38例,其中内支架术联脾肾分流术治疗5例,支架术联合肠腔分流术治疗8例;腔房人工血管转流术治疗4例,肠腔转流术治疗2例,肠颈转流术治疗2例,经右心房联合破膜2例。结果:随访1个月-9年,平均4.68年,37例获显疗效,2例改善,6例行二次手术治疗,3例死亡。结论:应重视早期诊断和治疗。腔内超声介入方法治疗布一加综合征,简便、准确、安全、疗效肯定;联合分流术解除肝静脉梗阻,可获得满意疗效。  相似文献   
62.
Summary Aged common marmosets were treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP; 0.5–2.0 mg/kg/week i.p.) for 16 or 24 weeks, observed for a total of 30 weeks and then killed for measurement of biochemical pramaters in basal ganglia. The MPTP treatment induced a marked depletion in dopamine, 3,4-dihydroxyphenylacetic acid and homovanillic acid levels in the caudate nucleus and putamen. In contrast, the concentrations of five neuropeptides: [Met5]-enkephalin, [Leu5]-enkephalin, cholecystokinin, substance P and neurotensin as measured by a combined HPLC/RIA method, remained unaltered in all basal ganglia regions examined. Enkephalin precursor levels, as reflected by cryptic [Met5]-enkephalin content, were increased in the putamen, but not in the caudate nucleus, as a consequence of MPTP administration. Cryptic [Leu5]-enkephalin content remained unchanged in the striatum of MPTP treated marmosets. Overall, these results suggest an increase in striatal [Met5]-enkephalin release following chronic MPTP treatment of aged marmosets. However, the chronic treatment of aged marmosets with MPTP does not reproduce the neuropeptide alterations characteristic of Parkinson's disease.  相似文献   
63.
The anti-granulocyte activity of serum from patients with B-cell chronic lymphocytic leukaemia (CLL) and other lymphoproliferative disorders was investigated. Granulocyte-binding IgG was measured in 34 patients with CLL, 13 patients with hairy cell leukaemia, one patient with prolymphocytic leukaemia, two patients with Sézary cell leukaemia, and seven patients with chronic T-cell lymphocytosis who had a predominance of circulating large granular lymphocytes. Anti-granulocyte activity was absent in CLL and its variants, but present in the majority of granulocytopenic patients with chronic T-cell lymphocytosis. In one of these patients, granulocytopenia was associated with complement-activating IgG granulocyte antibody. Thus, antibody-mediated granulocyte injury appears to be an unusual occurrence in chronic lymphocytic leukaemia, but is a frequent complication of chronic T-cell lymphocytosis.  相似文献   
64.
目的:对硬脑膜动静脉瘘临床诊断治疗特点进行探讨。方法:对60例患者行血管内栓塞治疗,5例行颈动脉压迫法治疗。其中13例1次栓塞,25 例行2次栓塞,17例行3次栓塞,5例行4次或多次栓塞,结果:治愈36例,好转25例,4例无效,无一例死亡,结论:硬脑膜动静脉瘘的临床表现和预后与其发病部位,静脉引流类型密切相关,颈动脉压迫法及选择性血管内栓塞是安全有效的治疗方法。  相似文献   
65.
荷包环扎式结直肠吻合保肛术治疗低位直肠癌*   总被引:1,自引:1,他引:0  
目的 :评价荷包环扎式结直肠吻合保肛术治疗低位直肠癌的价值。方法 :对低位直肠癌采用荷包环扎结直肠吻合保肛术治疗 2 3例 (A组 ) ,采用Miles手术治疗 2 6例 (B组 )。结果 :A组术后 1、3年生存率分别为 10 0 % (2 3/ 2 3) ,95 7% (2 2 / 2 3) ,术后无局部复发病例 ;排便功能优 16例 (6 9 6 % ) ,良 7例 (30 4 % )。B组术后 1、3年生存率分别为 10 0 % (2 6 / 2 6 ) ,96 2 % (2 5 /2 6 ) ,术后局部复发率 3 8% (1/ 2 6 )。两组术后 1、3年生存率 ,局部复发率经统计检验 ,均无显著差异 (P值均 >0 0 5 )。术后并发症 :A组无吻合口瘘及吻合口狭窄发生 ,盆腔感染 1例。B组 :切口感染 1例 ,人工肛门狭窄 1例。结论 :采用螺纹支架管荷包环扎结直肠吻合保肛术治疗低位直肠癌既能达到根治目的 ,又有保留肛门的良好排便功能 ,且并发症少 ,操作简便易行 ,不用特殊器械 ,值得推广应用  相似文献   
66.
外伤性延迟性脾破裂的诊断和治疗(附21例报告)   总被引:1,自引:0,他引:1  
目的探讨外伤性延迟性脾破裂的发病规律、临床特点、诊断和治疗方法。方法结合国内外资料及本组病例进行回顾性分析。结果明确诊断16例,误诊为肝破裂2例,宫外孕破裂2例,脾肿瘤1例。21例均手术治疗,行脾切除14例,其中保留副脾2例;脾切除加自体脾组织网膜内移植术3例;脾缝合修补术3例;脾部分切除术1例。死亡1例,原因有就诊晚、失血性休克。结论本病由于腹腔内出血与受伤时间间隔长,容易误诊。诊断除依靠病史、临床表现外,应及时进行腹腔穿刺、B超及CT检查。治疗以脾切除为主,可根据病情、脾破裂的程度以及是否有合并伤等情况采取保脾手术。  相似文献   
67.
68.
Many studies have recently reported on laparoscopic liver resection, although its development has been slow compared to laparoscopy in other fields. The indications for the location of laparoscopic liver resection have previously been limited to easily accessible lesions. Performing laparoscopic liver resection in the posterior and superior parts of the liver has been considered difficult due to inadequate exposure, the poor operative field and the difficulty with parenchymal dissection. Flexible endoscopy, high definition imaging and various kinds of equipment for parenchymal transection have been introduced for clinical use. In addition, much experience with this procedure has been accumulated at many centers. Accordingly, there are an increasing number of reports on laparoscopic liver resection in difficult locations. At our institution, the location of the tumor is no longer a limitation to laparoscopic liver resection. However, for safer laparoscopic liver resection, the patient positioning and trocar placement should be individualized according to the tumor location. The type of resection also may depend on the remaining liver’s functional capacity. We describe here the technical considerations for performing laparoscopic liver resection, including the technical considerations for performing laparoscopic liver resection for lesions located in the postero-superior segments of the liver.  相似文献   
69.
We provide further evidence for the two-factor structure of the 9-item Academic Expectations Stress Inventory (AESI) using confirmatory factor analysis on a sample of 289 Canadian adolescents and 310 Singaporean adolescents. Examination of measurement invariance tests the assumption that the model underlying a set of scores is directly comparable across groups. This study also examined the cross-cultural validity of the AESI using multigroup confirmatory factor analysis across both the Canadian and Singaporean adolescent samples. The results suggested cross-cultural invariance of form, factor loadings, and factor variances and covariances of the AESI across both samples. Evidence of AESI's convergent and discriminant validity was also reported. Findings from t-tests revealed that Singaporean adolescents reported a significantly higher level of academic stress arising from self expectations, other expectations, and overall academic stress, compared to Canadian adolescents. Also, a larger cross-cultural effect was associated with academic stress arising from other expectations compared with academic stress arising from self expectations.  相似文献   
70.
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