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   573843篇
  免费   55936篇
  国内免费   35514篇
耳鼻咽喉   5780篇
儿科学   8816篇
妇产科学   3993篇
基础医学   38356篇
口腔科学   10733篇
临床医学   68949篇
内科学   52898篇
皮肤病学   6254篇
神经病学   15637篇
特种医学   22564篇
外国民族医学   68篇
外科学   52639篇
综合类   151158篇
现状与发展   145篇
一般理论   10篇
预防医学   62808篇
眼科学   8458篇
药学   67755篇
  903篇
中国医学   56957篇
肿瘤学   30412篇
  2024年   2826篇
  2023年   7558篇
  2022年   19388篇
  2021年   24269篇
  2020年   20609篇
  2019年   12549篇
  2018年   13336篇
  2017年   16631篇
  2016年   13310篇
  2015年   23698篇
  2014年   29808篇
  2013年   36004篇
  2012年   52355篇
  2011年   55433篇
  2010年   47919篇
  2009年   42055篇
  2008年   44407篇
  2007年   43142篇
  2006年   38372篇
  2005年   30560篇
  2004年   21425篇
  2003年   18251篇
  2002年   14325篇
  2001年   12349篇
  2000年   9399篇
  1999年   4344篇
  1998年   1687篇
  1997年   1554篇
  1996年   1330篇
  1995年   1130篇
  1994年   968篇
  1993年   597篇
  1992年   563篇
  1991年   463篇
  1990年   407篇
  1989年   302篇
  1988年   258篇
  1987年   280篇
  1986年   240篇
  1985年   171篇
  1984年   93篇
  1983年   99篇
  1982年   68篇
  1981年   41篇
  1979年   43篇
  1965年   39篇
  1963年   39篇
  1959年   64篇
  1958年   49篇
  1957年   38篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
41.
四川汶川发生里氏8.0级地震后,第二军医大学第七医疗队于5月15日凌晨抵达重灾区江油市,至7月7日离开54d中,共处理开放性胫腓骨骨折43例.山于地震伤在不同时期、不同震级、不同地理环境及建筑物条件下都有其不同的特点,加上胫腓骨开放性骨折的高致残率(截肢、感染、肢体短缩)在地震伤中的高发生率[1],故将这43例的病例特点及我们的救治体会总结如下.  相似文献   
42.
A conjugate of antisense oligodeoxynucleotide (AS ODN) covalently linked with deoxorubicin (DOX) was synthesized. Its properties and antitumour activity in human carcinoma DOX resistant cells (KB-A-1) were investigated in vitro. The results showed that the conjugate was strongly stable both in Dulbecco's Phosphate-Buffered Saline (PBS) and in culture medium. The intracellular concentration of the conjugate was higher than that of the AS DON by HPLC analysis. The conjugate showed potent dose-dependent inhibition to the growth of KB-A-1 cells. Chemosensitivity of KB-A-1 cells to DOX was also investigated in vitro. When the cells were first exposed to the conjugate (0.5 microM) and then exposed to DOX for 24 h, the IC50 value of DOX decreased from 21.5 to 2.2 microM. In contrast, when treated with the mixture of the same concentration of the AS ODN with equivalent DOX, the IC50 value of DOX was 16.8 microM. Intracellular DOX concentration was detected in KB-A-1 treatment with the conjugate in vitro by HPLC. The results showed that the intracellular DOX concentration was 6.4-fold increased in KB-A-1 cells treated with the conjugate compared to treatment with DOX alone. In contrast, 1.8-fold increasing was observed when treated with the AS ODN. Western blot analysis showed a significantly decrease in the amount of P-glycoprotein in KB-A-1 cells. These results suggest that the conjugate is effective in reversing multidrug resistance. Certainly, further studies are conducting to explore the antitumour effect of the conjugate in vivo.  相似文献   
43.
44.
The performances of three widely different cathode materials (Pt, strontium-doped lanthanum manganite (LSM), and NiO) have been compared for use with proton conducting Li2SO4–Al2O3 composite electrolyte, using H2S–air and H2–air fuel cells operating at 600 °C. Surface analysis and electrochemical techniques were used to characterize fresh and used electrode materials. Pt or LSM cathodes each became covered with Li2SO4 and Al2O3 and, as a consequence, the fuel cells showed poor performance. In contrast, the NiO cathode catalyst did not become covered with Li2SO4 and good fuel cell performance was achieved. Exceptionally good current densities of over 100 mA/cm2 and power densities of over 30 mW/cm2 were obtained for H2S–air fuel cells having Mo–Ni–S anode catalysts. Slight agglomeration of NiO particles during fuel cell operation had only a minor effect on performance.  相似文献   
45.
应用彩色多普勒组织显像(DTI)比较观察10例川畸病(KD)患儿与143例正常儿童二尖半环、左室壁及心内膜不同时相运动速度的变化.结果显示10例KD患儿的二尖半环舒张早期运动速度(MVR-DeV)明显降低,与对照组比较有显著差异,同时KD患儿M VR-DeV的异常率显著高于DTI的其它检查指标.  相似文献   
46.
目的:探讨针刺结合脑超声治疗仪治疗脑梗死恢复期的疗效。方法:选择经CT或MRI证实的脑梗死患者60例,随机分为治疗1组和治疗2组,治疗1组在治疗2组的基础上接受脑超声治疗,集声、电同步治疗技术,每次治疗30min,每日1次,10次为1疗程,治疗2个疗程。结果:治疗1组总有效率为90.0%,治疗2组为73.3%,差异有统计学意义(P〈0.05)。结论:针刺结合脑超声治疗仪治疗脑梗死恢复期有明显疗效。  相似文献   
47.
自体表皮细胞培养与异体真皮组合应用研究   总被引:13,自引:0,他引:13  
严重烧伤病人皮肤修复中主要未解决的问题是真皮的替代。动物实验结果表明,异体皮移植后5天,用自体培养表皮细胞膜片覆盖真皮床,14天后复合皮成活率是84.6%±2.4%。组织学检查证实表皮已形成了复层结构,可见基底层、颗粒层和角质层。临床应用中,异体皮移植后10天,去除异体表皮覆盖病人的自体培养表皮,35天后未见排斥征象,异体真皮促进了培养表皮的分层、成熟和完整,组织学检查证实表皮细胞的边缘清楚,已分化形成颗粒层和角质层,真皮多细胞,已血管化,但表皮嵴缺乏。  相似文献   
48.
Type IIIC tibial fractures are complex injuries involving extensive bone and soft-tissue devascularization that result in a high percentage of complications and ultimate amputation. An emergency free flap transfer not only may salvage the limb but also may improve the aesthetic and functional results of reconstruction by placing the injured structures in a well-vascularized bed. Two cases of type IIIC tibial fracture were treated in this manner, and we present our experience with a 30-month follow-up of one patient and a 6-month follow-up of another patient.  相似文献   
49.
四叠体池蛛网膜囊肿   总被引:2,自引:0,他引:2  
目的:探讨四叠体池蛛网膜囊肿的临床特征和治疗方法。方法:对11例四叠体池蛛网膜囊肿进行了回顾性总结分析。所采用的手术方法有:①脑室分流手术;②囊肿-腹腔分流术;③囊肿切除;④囊肿切除加囊肿-脑池分流术,或囊肿部分切除(即囊肿开窗术),或囊肿切除加脑室-脑池分流术。结果:其主要临床表现以颅内压增高症和中线综合征为主。上述方法中单纯囊肿壁切除只能使部分病人的病情缓解,脑室分流或囊肿切除加脑室分流手术的疗效较好。结论:四叠体区蛛网膜囊肿常合并梗阻性脑积水,单纯囊肿切除不能解除多数病人的梗阻性脑积水。作者根据囊肿是否与蛛网膜下腔相通提出:对交通性蛛网膜囊肿采用单纯性脑室分流术,对非交通性者采用囊肿切除加脑室分流手术的治疗方法。  相似文献   
50.
A national screening programme for antibody to hepatitis C virus (HCV) in blood donors in Taiwan began in July 1992 using a second-generation immunoassay. To study the impact of this screening on post-transfusion hepatitis in Taiwan, a prospective study on post-transfusion hepatitis, that was started in 1987, was continued. As of June 1994, 245 patients who received a blood transfusion after July 1992 had completed a follow-up period for more than 6 months post-transfusion. Of them, seven (2.8%) recipients developed acute post-transfusion hepatitis. The hepatitis in six cases could not be attributed to infection by hepatitis A, B, C, D, E viruses or cytomegalovirus (CMV) or Epstein-Barr virus (EBV). The remaining patient seroconverted to both IgG and IgM anti-CMV. All seven patients recovered in 6 months without development of chronicity, and the mean peak alanine aminotransferase level was lower compared with that of the cases before anti-HCV screening (i.e. pre-July 1992). These results indicate that the current anti-HCV screening has effectively interrupted HCV transmission through blood transfusion in Taiwan.  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