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   87907篇
  免费   8179篇
  国内免费   5838篇
耳鼻咽喉   600篇
儿科学   1037篇
妇产科学   1317篇
基础医学   10634篇
口腔科学   1728篇
临床医学   11310篇
内科学   13827篇
皮肤病学   901篇
神经病学   4865篇
特种医学   3138篇
外国民族医学   37篇
外科学   8418篇
综合类   14065篇
现状与发展   14篇
一般理论   12篇
预防医学   5950篇
眼科学   2312篇
药学   9390篇
  90篇
中国医学   4762篇
肿瘤学   7517篇
  2024年   358篇
  2023年   1426篇
  2022年   3592篇
  2021年   4511篇
  2020年   3385篇
  2019年   2940篇
  2018年   3133篇
  2017年   2790篇
  2016年   2583篇
  2015年   3910篇
  2014年   4778篇
  2013年   4430篇
  2012年   6718篇
  2011年   7146篇
  2010年   4516篇
  2009年   3598篇
  2008年   4858篇
  2007年   4667篇
  2006年   4259篇
  2005年   4163篇
  2004年   2984篇
  2003年   2665篇
  2002年   2384篇
  2001年   1957篇
  2000年   2043篇
  1999年   2158篇
  1998年   1365篇
  1997年   1376篇
  1996年   1059篇
  1995年   1026篇
  1994年   852篇
  1993年   523篇
  1992年   609篇
  1991年   546篇
  1990年   461篇
  1989年   409篇
  1988年   334篇
  1987年   326篇
  1986年   246篇
  1985年   201篇
  1984年   128篇
  1983年   84篇
  1982年   63篇
  1981年   52篇
  1980年   33篇
  1979年   46篇
  1978年   18篇
  1973年   17篇
  1972年   17篇
  1966年   19篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
34例高血压病患者服国产吲达帕胺后,血压持续缓慢下降,TPR显著下降,血浆肾素活性(RA)、血管紧张素Ⅱ(AT-Ⅱ)和醛固酮(ADS)浓度显著增高,而心率及血儿茶酚爱(CA)水平无显著变化。治疗4周对全轿Cd,Pb,红细胞(RBC)及血浆Zn,Cu,Na,K,Mg浓度无显著影响。其总疗效为88.24%,表明国产吲达帕胺是一种疗效显著而副作用低的降压药物。  相似文献   
92.
Congenital analgesia is a rare genetic disorder. We report here that a 12-year-old boy was able to recover from congenital insensitivity to pain. Neurological examinations revealed that there was a 'stocking' distribution of pain decrement on the lower extremities under the patient's knee joints. Magnetic Resonance Imaging (MRI) of his brain showed gyrus thinning with sulcus widening at both sides of the parietal lobe. Southern blot hybridization probed with cDNAs of various opioid receptors did not detect any significant abnormality. Our results suggest that this rare case may not be genetically determined.  相似文献   
93.
头皮缺损颅骨外露的修复   总被引:1,自引:0,他引:1  
我科1980~1991年收治外伤性或颅面部肿瘤切除后头皮缺损颅骨外露9例,分别应用吻合血管的游离大网膜结合中厚皮片移植、游离皮瓣或轴型皮瓣转位结合皮片移植修复。讨论了修复时机、修复方法以及手术注意事项。认为双侧股前外侧游离皮瓣是修复全头皮缺损颅骨外露的可取方法,而吻合血管的游离大网膜移植修复颅骨外露的方法应尽量避免。  相似文献   
94.
Adultacuteleukemia (AL)isoneofthemostcommonmalignanttumorsofhematology .Withtherecentprogressinchemotherapyandsupportivether apy ,theremissionandsurvivalrateinALhavebeenmarkedlyimproved .However ,drugresistanceandrelapsearestillimportantfactorsaffectinglongsur vivalofthese patients .Theabnormalregulationofcellcycleisanotherfactorthatcannotbeignoredex ceptformultipledrugresistance (MDR) .WedetectcyclinA ,multidrugresistantgene (mdrl) ,topoiso meraseⅡα(TopⅡα)andbcl 2inadultpatientswithA…  相似文献   
95.
乌贼墨诱生小鼠细胞毒因子活性的检测   总被引:11,自引:2,他引:9  
用乌贼墨处理小鼠后,采集血清。经体外细胞毒实验证明:乌贼墨诱生的血清对人和鼠的肿瘤细胞株均有不同程度的杀伤作用。这一结果提示:乌贼墨可能具有诱生内源性细胞毒因子产生的活性。  相似文献   
96.
Temperature-sensitive mutant vaccines protect rats against Mycoplasma pulmonis infection. The role of the humoral or cellular immune response in resistance to mycoplasma infection was investigated by adoptive-transfer experiments. Spleen cells from Lewis rats vaccinated but not challenged with wild-type organisms (vaccinated) and spleen cells from rats vaccinated (or not) and challenged were effective in preventing syngeneic recipients from developing respiratory disease. There was also a significant reduction in the incidence and number of challenging organisms in the respiratory system. In contrast, sera from the same donors had no detectable effect on the number of mycoplasmas recovered or on lesion development in the respiratory tract. We conclude that cellular immunity rather than humoral immunity generated in vaccinated rats confers protection against subsequent infection.  相似文献   
97.
The purpose of this study was to test the feasibility of MR-guided percutaneous ethanol ablation of liver tissue on a .2-T open MR scanner. Needles were placed by MR guidance first into an ex vivo sheep liver and then into livers of three anesthetized pigs, and injection of 10 ml of 96% alcohol was performed. T1 fast low-angle shot (FLASH), T2 turbo spin echo (TSE), and T1 spin echo (SE) images were obtained after incremental volumes of injection. In one pig, simultaneous injection of saline into normal liver was also performed with subsequent pathological correlation. Ethanol-infiltrated liver was hypointense to liver on all sequences, whereas saline caused no tissue signal changes on T1 SE and either isointense or hyperintense changes on T2 TSE images. Pathological examination confirmed ethanol-induced acute liver changes as compared with the control. MR guidance of needle placement and monitoring of ethanol effects on liver tissue is feasible. This may have implications for potential MR-guided hepatic tumor ablation.  相似文献   
98.
Several types of chronic pain syndromes are effectively treated with sodium channel blockers such as lignocaine. Further investigation of this therapeutic modality would be facilitated by refinement of the parameters describing lignocaine distribution and elimination. This would allow precise lignocaine infusion by a computer-controlled infusion to attain and maintain stable target lignocaine concentrations. Arterial blood samples were obtained at frequent intervals during a computer-controlled infusion of lignocaine in 12 adult human volunteers. Plasma lignocaine concentrations of 1, 2, 3, 4 and 5 microg/ml were targeted for 15 min at each concentration. A three-compartment mammillary pharmacokinetic model best described the resulting concentration vs time profile. A population pharmacokinetic analysis was performed using three different techniques; the two-stage, pooled and mixed effects modelling. There was marked overshoot of the plasma concentration above the target prior to refinement of the pharmacokinetic parameters. The best parameters of a three-compartment mammillary model fit to the measured concentration using the pooled data approach were: V(1) = 7.44, V(2) =11.5 and V(3) = 97.71; Cl(1) = 0.585, Cl(2) = 2.23 and Cl(3) =1.64 l/min. Similarly calculated parameters using NONMEM were V(1) = 6.99, V(2) =12.2 and V(3) =1341; Cl(1) = 0.703, Cl(2) =1.24 and Cl(3) =1.49 l/min. The addition of age as a covariate of the pharmacokinetic parameters improved the model in both cases. Height, lean body mass and body surface area as covariates of the pharmacokinetic parameters did not improve the predicted value of the model. Prospective testing of the pharmacokinetic parameters will be required to define whether they function well. The refinement of pharmacokinetic parameters for the computer-controlled intravenous infusion of lignocaine will facilitate further research in pain therapy. Published lignocaine pharmacokinetic values have a relatively large central volume of distribution, and hence, when implemented as a computer-controlled infusion, result in dramatic overshoot shortly after targeting a higher plasma concentration. In light of the long-lasting pain relief provided by sodium channel blockade in neuropathic pain states, overshoot of plasma concentrations must be avoided if the concentration vs effect relationship is to be defined.  相似文献   
99.
Pulmonary embolism (PE) is an important health problem and often a major clinical challenge, not only because of the low specificity of its clinical manifestations but also because of the increasing number of medical circumstances that are risk factors for this illness and the importance of early identification, since prompt and appropriate treatment can decrease mortality from this disease by about 25%. In recent years research on PE has been extensive, directed mainly at trying to determine and characterize its risk factors, establish new clinical probability algorithms, develop new diagnostic methods and put existing ones into perspective, seek new therapeutic approaches (pharmacological and non-pharmacological), and above all establish protocols that can guide the clinician from the stage of clinical suspicion to measures to prevent recurrence. It was the authors' aim to review the most significant literature on this subject, in order to produce a text that reflects the state of the art concerning PE and that can be used as a guide in the clinical approach to this pathology.  相似文献   
100.
目的探讨输尿管镜气压弹道碎石治疗输尿管结石的效果。方法2004年2月~2005年3月,我们对185例输尿管结石(其中伴肾绞痛96例)采用输尿管镜取石或气压弹道碎石进行总结和分析。结果失败12例,其中6例改开放手术,6例术后3d行体外冲击波碎石。一次碎石成功率93.5%(173/185),其中上段结石为75.0%(24/32),中段为95.8%(46/48),下段为98.1%(103/105)。肾绞痛者成功率为100%(96/96)。术中输尿管损伤率2.9%(5/173),其中3例(1.7%)中转开放手术。术后肾绞痛1例。全组随访6~12个月,平均10.2月,无复发。结论输尿管镜气压弹道碎石安全有效,并发症少,是治疗输尿管中下段结石的首选方法,尤其对肾绞痛者疗效更好。  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