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   102260篇
  免费   11452篇
  国内免费   6828篇
耳鼻咽喉   828篇
儿科学   1687篇
妇产科学   1003篇
基础医学   8717篇
口腔科学   1976篇
临床医学   14488篇
内科学   11436篇
皮肤病学   1016篇
神经病学   3285篇
特种医学   3599篇
外国民族医学   36篇
外科学   6991篇
综合类   23795篇
现状与发展   36篇
一般理论   1篇
预防医学   10379篇
眼科学   2745篇
药学   12625篇
  193篇
中国医学   9252篇
肿瘤学   6452篇
  2024年   617篇
  2023年   1797篇
  2022年   4545篇
  2021年   5618篇
  2020年   4786篇
  2019年   3338篇
  2018年   3339篇
  2017年   3913篇
  2016年   3112篇
  2015年   5163篇
  2014年   6361篇
  2013年   6866篇
  2012年   9635篇
  2011年   10241篇
  2010年   7609篇
  2009年   6284篇
  2008年   6782篇
  2007年   6293篇
  2006年   5756篇
  2005年   4493篇
  2004年   3040篇
  2003年   2766篇
  2002年   2114篇
  2001年   1670篇
  2000年   1258篇
  1999年   860篇
  1998年   439篇
  1997年   424篇
  1996年   302篇
  1995年   295篇
  1994年   219篇
  1993年   101篇
  1992年   88篇
  1991年   78篇
  1990年   76篇
  1989年   46篇
  1988年   57篇
  1987年   37篇
  1986年   21篇
  1985年   14篇
  1984年   8篇
  1982年   6篇
  1981年   9篇
  1980年   5篇
  1979年   10篇
  1977年   5篇
  1970年   7篇
  1967年   3篇
  1966年   5篇
  1956年   3篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
T lymphocytes play a fundamental role in the initiation and regulation of chronic inflammatory responses in patients with asthma. CD69 is an early marker of T‐cell activation. The levels of intercellular adhesion molecule‐1 (ICAM‐1, CD54) and L ‐selectin have been reported to increase in patients with allergic diseases and asthma. The present study was therefore undertaken to investigate the expression of CD69, CD54, and L ‐selectin by T lymphocytes of children with asthma, before and after immunotherapy. Eighteen children newly diagnosed with asthma, 11 good and nine poor responders to immunotherapy, and 16 normal subjects, were enrolled in this study. The percentages of CD69+, CD54+, and CD62L+ cells in T lymphocytes were measured by using flow cytometry. The levels of CD69, CD54, and CD62L in serum and culture supernatants were determined by using enzyme‐linked immunosorbent assay (ELISA). The expression of CD69 and CD54 on CD3+ T lymphocytes was significantly higher in children with asthma than in control patients. All the patient groups expressed (spontaneously and following stimulation with phorbol myristate acetate and ionomycin together with mite‐extract proteins) greater amounts of CD69 and CD54 than did control subjects. With long‐term immunotherapy, the percentages of CD69+ and CD54+ T lymphocytes were significantly lower in patients with a good response to immunotherapy. Our results also showed significantly lower serum L ‐selectin levels following immunotherapy. In conclusion, successful immunotherapy resulted in decreased expression and production of CD69 and CD54. These results may explain, in part, the clinical efficacy of immunotherapy.  相似文献   
12.
Seventy-two patients of chronic obstructive pulmonary disease (COPD) of Qi deficiency syndrome with abnormal immune indices were treated with Yiqi Mianyi Granule (YQMYG) and the efficacy was compared with that of 30 cases treated with Zhenqi fuzheng Granule (ZQFZG) for control. Results showed that the markedly effective rate of symptomatic improvement of Qi deficiency in YQMYG group was 65.3%, the total effective rate 93.1%. 88.6% of the immune indices lower than normal were corrected and 43. 7% of them were normalized, while for indices that were higher than normal the rate were 78.2% and 52.9% respectively. These results suggested that YQMYG could improve symptom of Qi Deficiency markedly, strengthen cellular immunity and regulate immune dysfunction. Its therapeutic efficacy was obviously superior to ZQFZG (P<0.Q5).  相似文献   
13.
Background : The present paper addressed the issue of whether pretreatment with intravenous (IV) chemotherapy affects response rate or survival in patients receiving hepatic artery chemotherapy (HAC). Methods : Case note reviews of 164 patients treated in a teaching hospital from June 1990 to July 1996 were carried out. Results : The response rate and carcino-embryonic antigen (CEA) fall in the two groups was almost identical. There was a nonsignificant survival advantage in the non-pretreatment group. Conclusions : Previous administration of IV chemotherapy did not affect the CEA response of patients receiving HAC.  相似文献   
14.
Ostial PV Isolation:   总被引:2,自引:0,他引:2  
Pulmonary vein (PV) isolation by elimination of spike potentials has been reported to cure drug refractory atrial fibrillation. Because of the heterogenous morphology of the PVs, sequential electroanatomic reconstruction of the PVs was performed in 39 patients (group A), who underwent subsequent PV isolation by interruption of all conductive myocardial fibers by distinct RF current applications using a "lasso" approach. In group B (157 patients), only biplane two-dimensional fluoroscopy was performed to guide the diagnostic and the ablation catheters. After reprocedures (in 7% of patients in group A and 22% of group B), which depicted a recurrence of a spike potential inside or at the ostium of  >1 previously isolated PV in all restudied patients, stable sinus rhythm was documented in 69% of patients in group A and 60% of patients in group B. Reasons for the relapse of the previously eliminated spike potentials include a temporary ablation effect and a too distal interruption of the conducting myocardial fiber. Detailed knowledge of the individual three-dimensional morphology enhanced the clinical success rate of PV isolation but is time-consuming using CARTO   (8.0 ± 1.7 vs 5.0 ± 1.6, P < 0.001)   . Further technical improvement to fuse the individual three-dimensional anatomy and the electrophysiological markers to a composed "electroanatomic" map may overcome this limitation in the future. (PACE 2003; 26[Pt. II]:1624–1630)  相似文献   
15.
郑景浩  苏肇伉 《上海医学》1995,18(3):128-130
小儿先心病术后左房夺和肺动脉压力的监测在ICU中十分重要。心电图是论断和评价心脏疾患的常用方法。本文分析了32例小儿先心病手术前后(伴肺动脉高压16例)6个肢体导联心电图中P波和QRS波时限总和及振幅总和与左房、肺动脉压力的关系。结果表明两者均有良好的相关性(r=0.85 ̄0.88,r=0m74 ̄0.80,P〈0.01),该法简单、方便,可广泛开展,尤其在术后未放置PA和LA管或在IOU中已拨除L  相似文献   
16.
吸碘率曲线下面积与Graves病^131I治疗效果的观察   总被引:1,自引:0,他引:1  
目的:分析131I治疗格雷夫斯(Graves)病的疗效与吸碘率曲线关系以探讨确定个体化给药剂量的可能。材料和方法:152例应用131I治疗的Graves病患者,根据疗效被分为治愈组和未愈组,比较两组间年龄、甲亢病史、甲状腺重量、血清游离T4、131I治疗剂量、24小时吸碘率以及吸碘率曲线下相对面积等。结果:两组间患者在甲状腺重量、甲亢发病时间、服药剂量、血清游离T4等方面均无显著性差异。未愈组患者年龄小于治愈组,两组间24小时最大吸碘率间无明显差异,但治愈组吸碘率曲线下相对面积(72.6±18.1)明显小于未愈组(81.5±15.4,P<0.005)。所有131I治疗患者的24小时最大吸碘率(88.2±12.5)明显大于吸碘率曲线下相对面积(75.8±17.6,P<0.001)。结论:Graves病患者吸碘率曲线下面积较24小时最大吸碘率更能够反应甲状腺组织的摄碘功能,可能是用来指导给药量计算的更好参数。  相似文献   
17.
目的:评价张力带固定法治疗锁骨远端骨折的临床效果。方法:对20例锁骨远端骨折行切开复位后张力带固定法治疗。术后随诊分析。结果:所有骨折均在半年内愈合。患侧肩关节功能恢复良好。无一例出现伤口感染。结论:张力带固定治疗锁骨远端骨折是一种简单可靠的手术方法。  相似文献   
18.
超声引导下肿瘤内注射^90钇玻璃微球的肝癌综合治疗   总被引:12,自引:0,他引:12  
董宝玮  梁萍 《中华医学杂志》1994,74(8):471-473,T048
超声引导下对28例肝癌病人进行了肿瘤内注射^90钇玻璃微球(Y-90GT MS)为主的综合性治疗(部分病人配合肿块周边注射无水酒精及门静脉穿刺化疗)。随访2~16个月(平均7.9个月),病人全健在。肿瘤缩小率为91%,其中显著缩小达75%;肿块回声呈致密增强,少数呈混合型或等回声型;肿瘤内及周边血流信号显著减少;原甲胎蛋白升高者13例,11例显著下降,其中6例降至正常;病人症状减轻,全身情况改善。  相似文献   
19.
目的探讨严重肺挫伤及缺血再灌注后早期肺泡灌洗液(BALF)中表面活性蛋白(SP)-A、B、C、D动态变化与肺功能及肺形态学改变的关系。方法75只兔随机分为对照组(A)、肺挫伤组(B)及缺血再灌注组(C)。每组均为25只。检测各组0,1,2,3,4h肺功能变化及BAIF中SP—A、B、C、D含量百分比,进行组织病理学及电镜检查。结果与A组比较,B、C组sSP—A、B、C、D含量百分比明显减少(P〈0.01);肺功能出现明显的损害且呈持续下降(P〈0.05);肺泡Ⅱ型细胞电镜及病理学检查呈不同程度的炎症及变性改变。结论严重肺挫伤BALF中SP—A、B、C、D动态变化与肺功能及肺组织病理学改变一致。  相似文献   
20.
住院糖尿病病人病情分析   总被引:1,自引:0,他引:1  
目的:通过对近年来我院住院糖尿病病人的资料分析,观察糖尿病转归、并发症的发生率及死亡原因.方法:查阅全院住院糖尿病病人病历,对患者的相关临床资料登记.结果:糖尿病患病率呈逐年增加的趋势,与1993年相比,1997年患病率增加0.5倍,1998年患病率增加1倍,2001年前半年增加2倍.2001年上半年住院糖尿病病人高血压、冠心病和心梗的患病率分别为39.1%,35.2%和6.7%,住院高血压病人糖尿病患病率由1998年的6%增至2001年的9%,住院冠心病病人糖尿病患病率增高约10%(P<0.01).住院心梗病人糖尿病患病率增高约15%(P<0.05).近3.5年,有2618例糖尿病病人住院(1.95%),与非糖尿病病人相比,病死率无显著性差异.糖尿病主要死亡原因为感染(41.2%),终末期肾病(39.2%)及癌症(31.4%).由于冠心病及脑血管意外死亡仅为15%及13%,而呼吸道感染(81%)及足感染(63%)为主要死因.结论:近8.5年中,在33 005病人中糖尿病病人逐年增多,特别是在近4年中,提高约2倍.高血压、冠心病及心梗病人糖尿病患病率逐年增高.近3.5年中住院糖尿病病人的死亡主要原因并非是心血管病变,而是感染.糖尿病病人癌症病死率有所增加.提倡早期诊断,早期预防,早期治疗糖尿病,采取健康的生活方式.  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