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   178577篇
  免费   16417篇
  国内免费   10626篇
耳鼻咽喉   1532篇
儿科学   2902篇
妇产科学   1621篇
基础医学   17185篇
口腔科学   3338篇
临床医学   22316篇
内科学   22949篇
皮肤病学   2340篇
神经病学   7872篇
特种医学   7037篇
外国民族医学   52篇
外科学   16404篇
综合类   36565篇
现状与发展   35篇
一般理论   9篇
预防医学   16135篇
眼科学   4267篇
药学   19454篇
  137篇
中国医学   11774篇
肿瘤学   11696篇
  2024年   519篇
  2023年   2045篇
  2022年   5198篇
  2021年   6989篇
  2020年   5573篇
  2019年   4517篇
  2018年   4749篇
  2017年   5025篇
  2016年   4852篇
  2015年   7406篇
  2014年   9599篇
  2013年   10413篇
  2012年   14942篇
  2011年   15702篇
  2010年   12241篇
  2009年   10563篇
  2008年   12020篇
  2007年   11840篇
  2006年   11070篇
  2005年   9598篇
  2004年   7627篇
  2003年   7490篇
  2002年   5906篇
  2001年   4712篇
  2000年   3641篇
  1999年   2510篇
  1998年   1362篇
  1997年   1475篇
  1996年   1016篇
  1995年   860篇
  1994年   756篇
  1993年   489篇
  1992年   487篇
  1991年   416篇
  1990年   370篇
  1989年   294篇
  1988年   257篇
  1987年   224篇
  1986年   174篇
  1985年   148篇
  1984年   88篇
  1983年   74篇
  1982年   45篇
  1981年   35篇
  1980年   23篇
  1979年   40篇
  1978年   36篇
  1976年   25篇
  1973年   27篇
  1970年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
Summary Thirty-one patients with stage IIIB or IV non-small cell lung cancer (NSCLC) were treated with intravenous 10-EdAM on a weekly basis. The starting dose was 80 mg/m2, with subsequent doses adjusted depending on evidence of toxicity. There were 20 men and 11 women with a median age of 58 years (range, 33–75). Response was evaluated in 30 patients, 5 with evaluable but not measurable tumors and 25 with measurable indicator lesions. There were no complete remissions; 3 patients achieved partial remission. Nine patients had a minor response, 6 showed no change, and 12 had progressive disease. Median survival for all 31 patients was 43 weeks (range, 12–65+). During the first 3-week period, the 10-EdAM dose was reduced or withheld in 19 patients (because of stomatitis in 12, SGPT elevation in 3, skin rash in 2, and granulocytopenia in 2), escalated in 11 patients, and unchanged in 1 patient. A mean of 34–88 mg/m2of 10-EdAM (median, 50) was given per week during the first 5-week period. Myelotoxicity was infrequent and there was no significant nephrotoxicity. Considering the modest side effects of this treatment and the conservative dose-modification schedule which mandated substantial dose reductions, we conclude that 10-EdAM is a promising antitumor agent for NSCLC.  相似文献   
142.
应用我室建立的化学发光自显影技术检测鸭沙门氏菌。用酶标抗体与硝酸纤维素膜上固定的细菌结合,再同发光底物溶液作用,使X线胶片感光,根据胶片上的黑斑进行半定量,可检出100个菌。其检测特异性好,约2小时即可出报告。  相似文献   
143.
Abstract: Juvenile xanthogranuloma is a xanthomatous and granulomatous condition that frequently arises before 1 year of age and mainly occurs on the head and trunk. We report a rare solitary juvenile xanthogranuloma on the right palm of a 10-year-old girl, present for one year. This solitary involvement of the palm has been reported only twice before.  相似文献   
144.
作者报告经病理诊断消化道恶性肿瘤患者30例及手术切除肿瘤患者15例的血浆胃动素水平,并以健康成人31例作为对照。消化道恶性肿瘤的胃动素水平373.4±123.7ng/L,显著高于正常对照组(162.3±52.3ng/L,P<0.001),而消化道恶性肿瘤患者术前及术后胃动素水平无显著差异。消化道恶性肿瘤患者胃动素水平增高的原因可能是肿瘤刺激神经所致。胃癌和结肠癌细胞可产生胃泌素样物质,它可刺激胃动素的释放。  相似文献   
145.
In an attempt to develop a new anticancer platinum complex with greater or equivalent antitumor activity but reduced side effects compared with cisplatin (CDDP), a series of new platinum complexes having a glycolate leaving ligand was synthesized. Among them, five complexes were selected for further development on the basis of adequate water solubility, low nephrotoxicity and high antitumor activity in a murine system. The chemosensitivity of these five complexes was examined in MTT assay against two human pulmonary adenocarcinoma cell lines, PC-9 and PC-14, and two human stomach adenocarcinoma cell lines, MKN-45 and KATO III. Their IC50 and relative antitumor activity (RAA) values were compared with those of CDDP and 254-S, a second-generation platinum complex with a glycolate leaving ligand under phase III clinical trial. The lowest mean IC50 value was observed in CDDP, followed by SKI 2034R and SKI 2033R. In this study, the antitumor activity was evaluated in terms of RAA values and SKI 2034R showed the highest RAA value. The order of RAA values was SKI 2034R > CDDP > SKI 2032R > SKI 2033R > SKI 2030R > SKI 2029R > 254-S. Based on the RAA order, we have recommended SKI 2034R as the most promising candidate for further development of a clinically useful platinum complex.  相似文献   
146.
我院1989年至1994年共行子宫颈癌广泛切除术和盆腔淋巴结清扫术39例,其中28例行术前放射治疗,19例临床诊断为Ⅱb,随着手术技术的提高和术前放射治疗的配合,子宫颈癌的手术适应症的选择,可以扩大至Ⅱb,不增加手术的并发症,并具有一定的优点。  相似文献   
147.
Ten (E)-and (Z)-isomers of 2-phenylcyclopropylamine (PCA), 1-Me-PCA, 2-Me-PCA, N-Me-PCA, and N, N-diMe-PCA and fifteeno , m, p isomers of (E)-PCA with substituents of Me, Cl, F, OMe, OH were synthesized in this laboratory and tested for the inhibition of rat brain mitochondrial MAO-A and MAO-B. The effects of substituents, their positions, and stereochemistry on the inhibition were assessed for the compounds with substituents at cyclopropyl and amino groups and QSAR analyses were performed using the potency data of ring-substituted compounds. The best correlated QSAR equations are as follows: pI50=0.804 Π2 Blo−1.069 Blm+0.334 Lp−1.709 HDp+7.897 (r=0.945, s=0.211, F=16.691, p=0.000) for the inhibition of MAO-A; pI50=1.815 π-0.825 Π2 R+0.900 Es2+0.869 Es3+0.796 Es4−0.992 HDp+0.562 HAo+3.893 (r=0.982, s=0.178, F=23.351, p=0.000) for the inhibition of MAO-B. Based on the potency difference between stereoisomers of cyclopropylamine-modified compounds and on QSAR results, it is proposed that the active sites of MAO-A are composed of one deep hydrophobic cavity near para position, two hydrophobic cavities interacting with Me group, a hydrophobic area accomodating phenyl and cyclopropyl backbone, steric boundaries, a hydrogen-acceptor site near para position, and an amino group binding site and that in addition to the same two hydrophobic cavities, hydrophobic area, steric boundaries, hydrogen-acceptor site, and amino group binding site, another steric boundary near para position and a hydrogen donating site near ortho position constitute active sites of MAO-B.  相似文献   
148.
在股骨颈移位骨折的治疗中,试用了7种不同的闭合复位方法。其中Whitman's法在骨折床台上进行,正常肢体外展,患肢由屈曲牵引至完全伸直位后,维持牵引并外展到与对侧肢体相称位,单髋人字石膏外固定(1914年)。 Leadbetter's法也在骨折床台上进行。将患肢髋部屈曲90°,沿大腿轴线行手法牵引。同时股骨干稍内收,患肢缓慢行环形活动至外展、内旋位,患肢向下降至骨折床台面时,行跟掌试验以验证是否完全复位(1933年)。 Bozan's法利用骨折床台使双下肢维持在伸直位,大绷带放置在患肢髂嵴部位,小绷带放置在患肢腹股沟皱襞最高点处实施牵引。然后整个患肢极度内旋,在维持侧方牵引的同时,患肢外展并轻度过牵(1934年)。  相似文献   
149.
对液化气燃烧后室内空气污染进行了流行病学调查,结果显示,液化气燃烧可造成SO_2、NO_2、空气总悬浮颗粒物和总烃类的室内空气污染。小鼠接触三个月出现T淋巴细胞计数降低、睡眠时间延长、骨髓嗜多染红细胞微核率增加、肺组织匀浆Ames试验阳性率增高、雄性小鼠精子畸形率增加,并有明显的剂量-反应关系。对接触5年以上的人群调查发现,呼吸道、鼻和眼的自觉症状明显增加,咽炎、鼻炎、结膜炎患病率增高。人群尿液浓缩物Ames试验和外周血红细胞微核率检出阳性结果,可能与液化气燃烧废气中含有致突变污染物有关。  相似文献   
150.
白细胞介素-10诱导的大鼠树突状细胞体外免疫功能的研究   总被引:19,自引:7,他引:12  
目的 研究白细胞介素 10 (IL 10 )诱导的大鼠未成熟树突状细胞 (imDCs)体外诱导免疫耐受的可行性。方法 在经典诱导方案的基础上 ,应用IL 10 ( 10 μg/L)抑制大鼠骨髓来源DCs的成熟 (IL 10组 ,10例 ) ,并设对照组 (IL 4组 ,10例 )。培养期间观察DCs形态 ,检测DCs表型、摄取抗原能力、体外免疫功能及培养上清细胞因子水平。结果 与IL 4组比较 ,IL 10组DCs细胞表面CD80 、CD86及OX6低度表达 ( 2 5 .3 %、42 .4%、3 2 .3 % ) ,吞噬能力较强 ( 81.9) ,刺激同种异体淋巴细胞增殖能力下降 ,该淋巴细胞具有抗原特异性低反应性 ;培养上清中IL 12水平 ( 4 0 6.5pg/L)及初次MLR培养上清IL 2水平 ( 2 45 .4ng/L)均较低 ,差异有非常显著性 (P <0 .0 1)。 结论 IL 10作用的大鼠imDCs具有诱导免疫耐受的应用价值。  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