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   28200篇
  免费   2790篇
  国内免费   2232篇
耳鼻咽喉   204篇
儿科学   315篇
妇产科学   313篇
基础医学   3706篇
口腔科学   476篇
临床医学   3861篇
内科学   4491篇
皮肤病学   247篇
神经病学   1441篇
特种医学   1003篇
外国民族医学   22篇
外科学   2927篇
综合类   4463篇
现状与发展   9篇
一般理论   4篇
预防医学   1696篇
眼科学   718篇
药学   2863篇
  31篇
中国医学   1503篇
肿瘤学   2929篇
  2024年   93篇
  2023年   446篇
  2022年   1128篇
  2021年   1654篇
  2020年   1228篇
  2019年   980篇
  2018年   1080篇
  2017年   920篇
  2016年   874篇
  2015年   1381篇
  2014年   1704篇
  2013年   1342篇
  2012年   2029篇
  2011年   2267篇
  2010年   1373篇
  2009年   1078篇
  2008年   1410篇
  2007年   1471篇
  2006年   1403篇
  2005年   1525篇
  2004年   897篇
  2003年   801篇
  2002年   750篇
  2001年   622篇
  2000年   617篇
  1999年   683篇
  1998年   517篇
  1997年   469篇
  1996年   395篇
  1995年   360篇
  1994年   286篇
  1993年   163篇
  1992年   225篇
  1991年   168篇
  1990年   147篇
  1989年   135篇
  1988年   154篇
  1987年   99篇
  1986年   95篇
  1985年   71篇
  1984年   41篇
  1983年   34篇
  1982年   28篇
  1981年   21篇
  1980年   10篇
  1979年   18篇
  1978年   5篇
  1975年   3篇
  1971年   5篇
  1969年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
连小赟  曹玉凤 《陕西中医》2007,28(7):920-921
目的:研究蟾皮、全蝎、蜂房对小鼠前胃癌及癌前病变的阻断作用及可能机理。方法:应用肌氨酸乙酯盐酸盐和亚硝酸钠灌胃建立小鼠前胃癌及癌前病变模型;免疫组化ELPS法测定单纯诱癌组(32只)、单纯中药组(20只)及中药阻断组(48只)p27,VEGF的表达。结果:单纯诱癌组癌及癌前病变发生率显著高于阻断组(P=0.002);p27的表达与组织分级可能相关,在癌前期及早期癌中表达增高,发展至浸润癌时表达下降;VEGF表达阳性率及强度随组织学分级进展呈现增高趋势,诱癌组表达阳性率显著高于阻断组。结论:蟾皮、全蝎、蜂房对小鼠前胃癌及癌前病变具有阻断作用,与对VEGF表达的调控有关。  相似文献   
152.
37例传染性非典型肺炎流行病学调查与讨论   总被引:1,自引:0,他引:1  
目的了解传染性非典型肺炎(SARS)流行病学的特点,提出相应的预防和控制措施.方法采取现场调查、网上电子病历审查、电话询问等方法.结果37例SARS患者的治愈率为89.2%,病死率8.1%,有接触史患者占37.8%.由于执行了严格的消毒隔离制度,医院内无任何人员感染发病.结论SARS患者在年龄上以青壮年为多,职业类以商业餐饮食人员为多.  相似文献   
153.
目的 利用聚合酶链反应的酶联免疫吸附试验 ,探讨检测自排尿脱落细胞端粒酶活性在膀胱癌早期诊断中的意义。方法 应用 (端粒酶重复序列扩增基础上PCR -ELISA)TRAP -PCR -ELISA方法检测 5 8例膀胱癌患者、 2 5例良性血尿患者及 30例健康体检者尿脱落细胞的端粒酶活性。结果  (1) 5 8例膀胱癌患者尿脱落细胞阳性率为 81 0 % (4 7/ 5 8) ,2 5例良性血尿患者及健康体检者均无端粒酶活性表达。 (2 )TRAP -PCR -ELISA方法检测膀胱癌患者尿脱落细胞端粒酶活性与常规尿细胞形态学镜检间的差别有非常显著性意义 (P <0 0 1)。结论 尿脱落细胞端粒酶活性的检测法对膀胱癌患者的阳性检出率较常规尿细胞形态学方法高 ,可用于膀胱癌的早期诊断。  相似文献   
154.
本文观察了频率为20Hz、振幅为0.67mm和作用时间为40min的振动预处理对急性缺氧小鼠肺损伤的影响。结果发现实验组的肺组织匀浆脂质过氧化物LghdPeroxde(LPO)、支气管肺泡灌洗液(BALF)中蛋白含量和白细胞数明显低于对照组(P<0.05)。这表明在特定率数的振动作用下能明显减轻急性缺氧小鼠肺的损伤。  相似文献   
155.
Summary The efficacy and safety of ivermectin in the treatment of filariasis due to Wuchereria bancrofti was assessed by a meta-analysis of the results from 15 published clinical trials. Seven hundred and forty-eight microfilaraemic patients were enrolled in 7 dose-finding and 8 comparative studies. Administered as a single dose, ivermectin induced nearly complete clearance of microfilariae from the blood from the first day to 30 days post-treatment, followed by gradual recurrence of microfilaraemia and increase in its intensity. Higher doses of ivermectin showed greater clearance effects and maintained lower microfilaraemia levels for a longer time. The adverse reactions caused by the drug were flu-like, transient, generally mild and well tolerated by patients. The frequency and intensity of adverse reactions were strongly associated with pretreatment microfilaria counts in the blood, but independent of dose. The findings of the meta-analysis suggest that ivermectin given at a single annual dose of 200 μg/kg body weight or higher, whether or not in combination with DEC, has great potential for therapeutic strategies to control bancroftian filariasis.  相似文献   
156.
OBJECTIVE: To measure and compare Chinese mandibular genial tubercles measured anatomically and with computed tomography (CT). STUDY DESIGN AND SETTING: Spiral CT scans were taken of 40 adult human skulls; the superior genial spines were measured using anatomic and CT methods. RESULTS: The height and width of the superior genial spines, mandible thickness, and distance from the menton to the inferior and superior margins of the superior genial spines were 5.82 +/- 0.71, 6.98 +/- 1.35, 11.95 +/- 1.59, 11.08 +/- 2.05, and 16.91 +/- 2.30 mm from anatomic measurements and 6.17 +/- 0.71, 7.01 +/- 1.13, 12.19 +/- 1.64, 10.41 +/- 1.55, and 15.73 +/- 2.12 mm using spiral CT, respectively. The anatomic and CT measurements were correlated. CONCLUSION: Spiral CT of the genial tubercles can help locate the osteotomy in genioglossus advancement. SIGNIFICANCE: This study acquired reference data on Chinese genial tubercles demonstrating that CT measurements of the genial tubercles reflect their anatomy, which should allow accurately locate the osteotomy.  相似文献   
157.
We detected the presence and distribution of HBcAg in the liver by immunohistochemistry (ABC method) and the presence of HBV-DNA in serum (spot hybridization) and anti-HBe in serum (ELISA) from 59 cases of hepatitis B hospitalized in our hospital, including 47 cases of CAH, 5 cases of CPH, and 7 cases of subacute fulminant hepatitis. 1. HBcAg in the liver was detected in 25 out of 47 cases (53%) of CAH, in 2 out of 5 cases of CPH and in 4 out of 7 cases of subacute fulminant hepatitis. The total percentage was 53% (31/59). 2. There was no positive correlation between HBV replication activity and liver disease activity (P greater than 0.05). Our results did not support the hypothesis that suggests a direct cytopathic effect of HBV. Oppositely, the fact was that the presence, the amount and the patterns of HBcAg in the liver, and the presence of HBV-DNA in serum were predominant in mild CAH compared with those in severe CAH, predominant in CAH without cirrhosis compared with those in CAH with cirrhosis. There was a tendency of inverse correlation between HBV replication activity and liver disease activity. The results above were in line with the concept that HBcAg expressed on the surface of infected hepatocytes may be relevant target for T lymphocyte cytotoxicity. The results have suggested that an immune response to HBV is present, leading to the destruction of most infected cells. 3. There was a positive correlation between HBV-DNA in serum and HBcAg in the liver (P less than 0.005), indicating that HBV-DNA in serum can represent HBV replication.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
158.
肝动脉化疗,栓塞与肝静脉暂时闭塞治疗肝癌   总被引:1,自引:0,他引:1  
本文报道在10例肝癌患者中运用肝静脉暂时闭塞和肝动脉内灌注化疗、栓塞的方法治疗取得较好疗效。7例甲胎蛋白阳性患者5例下降大于50%,2例转阴。4例肿瘤缩小>50%。2例合并肝动-静脉瘘者成功实行碘油栓塞,1例经治疗后肝动-静脉瘘消失。对肝功能的影响与普通介入治疗相同。消化道反应相对较轻。并可提高肿瘤局部药物浓度,延长药物作用时间。配合肝段动脉或靶血管的插管可进一步提高疗效,减少并发症。  相似文献   
159.
Celiac disease (CD) has one of the strongest class II HLA associations of any human illness. We used DNA-RFLP typing to study the class II HLA genotypes of celiac disease patients from the West of Ireland, the geographic area with the highest rate of celiac disease in the world. We confirmed the high frequency of HLA-DR3 in this population, and we were also able to demonstrate the additional risk of developing celiac disease imparted by HLA-DR7. This was done by clearly distinguishing DR7, DQ2 haplotypes from DR7, DQ9 haplotypes, and by "subtraction analysis" of haplotype frequencies. As reported in other populations, most of the patients without DR3 were heterozygous for DR7 and DR11 or 12 (DR5), or had DR4. We used PCR-RFLP and direct sequencing of amplified DNA to examine HLA-DR4 subtypes. The frequency of HLA-DR4 was markedly decreased in patients compared with controls (p=0.000001) and there was a significant alteration of DR4 subtypes of the patients compared with controls (p=0.0227). Moreover, all of the CD patients (5 of 5) with DR4 had a haplotype associated with the DQB1*0302 allele compared with only 11 of 23 control subjects with DR4. Our results in this population with exceptionally high risk of CD strongly support the DQ heterodimer hypothesis and suggest that the recently described sequence difference between the DQB1*02 alleles of DR3 and DR7 may contribute to a synergistic increased risk when these haplotypes are inherited together. In addition, our findings suggest a role for HLA-DQ in DR4-associated CD.  相似文献   
160.
采用PAS、波形蛋白(vimentin)、上皮膜抗原(EMA)、雌激素抗体(ER)和孕酮抗体(PR),对3例卵巢蜕膜结节(其中2例伴有腹膜结节),进行了免疫组织化学染色和光镜观察。结果3例均表达波形蛋白,而上皮膜呈阴性,支持蜕膜样细胞来源于体腔上皮。雌激素受体和孕激素受体显强阳性。说明妊娠期间,雌激素和孕激素的大量存在对异位蜕膜的形成和生长具有决定性的作用。  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