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   53040篇
  免费   5540篇
  国内免费   3739篇
耳鼻咽喉   503篇
儿科学   450篇
妇产科学   482篇
基础医学   5467篇
口腔科学   786篇
临床医学   6803篇
内科学   7285篇
皮肤病学   389篇
神经病学   2572篇
特种医学   2059篇
外国民族医学   22篇
外科学   5833篇
综合类   10609篇
现状与发展   6篇
一般理论   6篇
预防医学   4059篇
眼科学   1492篇
药学   5807篇
  64篇
中国医学   3631篇
肿瘤学   3994篇
  2024年   275篇
  2023年   973篇
  2022年   2458篇
  2021年   3066篇
  2020年   2448篇
  2019年   1848篇
  2018年   1983篇
  2017年   1813篇
  2016年   1799篇
  2015年   2670篇
  2014年   3299篇
  2013年   3171篇
  2012年   4772篇
  2011年   4885篇
  2010年   3462篇
  2009年   2755篇
  2008年   3022篇
  2007年   2940篇
  2006年   2698篇
  2005年   2427篇
  2004年   1551篇
  2003年   1372篇
  2002年   1103篇
  2001年   866篇
  2000年   749篇
  1999年   781篇
  1998年   444篇
  1997年   443篇
  1996年   361篇
  1995年   300篇
  1994年   267篇
  1993年   156篇
  1992年   172篇
  1991年   151篇
  1990年   148篇
  1989年   113篇
  1988年   108篇
  1987年   97篇
  1986年   83篇
  1985年   65篇
  1984年   49篇
  1983年   33篇
  1982年   17篇
  1981年   14篇
  1980年   14篇
  1979年   15篇
  1978年   16篇
  1974年   9篇
  1973年   8篇
  1969年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
目的:探讨原发性十二指肠腺癌的影像表现及与手术切除相关征象。方法:对照手术回顾性分析17例经病理证实的十二指肠腺癌低张十二指肠造影(hypotonic duodenography,HD)和CT的表现。结果:HD显示息肉型9例,溃疡型7例,浸润型1例。CT均示腔内不规则肿块或肠壁增厚,3例示溃疡,胆系扩张10例,胰头浸润14例,血管浸润7例,淋巴结转移3例,肝转移2例。7例行根治术,10例行姑息术。结论:HD与CT结合可充分显示腔内病变,腔外浸润及转移。癌肿局限于腔内或仅侵犯胰头时可行根治术;侵犯周围重要血管,发生淋巴结、肠系膜及肝脏等转移时一般只能行姑息术。  相似文献   
152.
Ligustrazini in the treatment of chronic cor pulmonale   总被引:2,自引:0,他引:2  
  相似文献   
153.
154.
In this study antigen-independent factor in the pathogenesis of chronic rejection of organ transplants was examined.Kidney isografts and allografts were transplanted orthotopically into bilaterally nephroectomized rat recipients and studied functionaaly,morphologically and immunohistologically,at serial intervals up to 52 weeks after transplantation.Allograft recipients developed progressive proteinuria after 12 weeks,with gradual renal failure ultimately leading to death.At the same time,morphological changes,including progressive arteriosclerosis and glomerulosclerosis ,tubular atrophy and interstitial fibrosis,developed.Immunohistologically,macrophages infiltrated glomeruli during this period and cytokines became unregulated.Our results showed that antigen-independent functional and morphological changes occurred in long-tern kidney isografts and mimicked those appearing much earlier in allografts that reject chronically.Initial injury and extent of functioning renal mass is suggested to be important factor for such late changes.  相似文献   
155.
Experiments were conducted to determine the cell source, stimulating agents, and incubation conditions that maximize interleukin-1 (IL-1) release by chicken macrophages/monocytes. Thymocyte co-mitogen proliferation was used to assay IL-1 activity of conditioned or partially purified supernatants. Monolayers of a transformed chicken macrophage cell line, HD11, released greater amounts of IL-1 than adherent cells isolated from peripheral blood, peritoneal cavity, or spleen. E. coli endotoxin and heat-killed S. aureus induced greater release of IL-1 by HD11 and splenic macrophages than latex or a super induction protocol with mezerien. Blocking macrophage eicosanoid synthesis with indomethacin did not influence IL-1 release from HD11 macrophages. Removing low molecular weight compounds from conditioned supernatants by dialysis did not influence IL-1 activity. IL-1 release was increased by incubating macrophages at 42 C compared to 39 C. Thymocyte co-mitogenic activity of IL-1 was increased by incubating thymocytes at 42 C compared to 39 C. Species cross reactivity between chicken and mammalian IL-1 was also investigated. Chicken IL-1 had slight co-stimulation activity on murine thymocytes, but murine and human IL-1 were without activity on chicken thymocytes.  相似文献   
156.
In order to investigate the effect of ligustrazine (Lig)i.p.on peritoneal permeability in peritoneal dialysis and its side effects,creatinine was given intravenously and continuously to maintain the high plasma creatinine level.All the rabbits were divided into three groups:normal control group (goup A),group B treated with 0.12% Lig and group C treated with 0.24% Lig.The peritoneal dialysis of all rabbits lasted 2h.The plasma and dialysate levels of glucose,protein and creatining were observed immediate,30min,60min,90min,120min after dialysis.Creastinine dialysate/plasma ratio (D/P),protein D/P ratio,grucose D/Do at different time points after dialysis and creatinine mass transfer area coefficient (MTAC) at 120min were calculated.The structures of peritoneum were observed under optical microscope and electron microscope after continuously intraperitoneal injection of Lig for 14 days.The results showed that the 90-min and 12-min creatinine D/P ratios in the group C were higher than in the group A.The 120-min creatinine MATC in the group C was higher than in the group A.The rabbits treated with Lig did not show significant structure changes of peritoneum and signs of peritoneal irritation.It was suggested that Lig could increase mass transfer ability of peritoneum without significant side effects.  相似文献   
157.
控制性降压在鼻内窥镜手术中的应用   总被引:2,自引:0,他引:2  
王彭  孙进军  王绪锐  于飞 《吉林医学》2002,23(5):270-271
目的 :观察控制性降压在鼻内窥镜手术中应用的意义。方法 :80例双侧鼻息肉、鼻窦炎患者 ,局麻、鼻内窥镜下行双侧鼻息肉摘除、全筛切除及开放上颌窦自然开口。其中 38例术中控制性降压 (降压组 ) ,另 42例作为对照。结果 :降压组术中出血 (6 1 39± 38 5 2 )ml,对照组出血 (140 12± 81 82 )ml,差异有显著性意义 (P <0 0 1) ;手术时间分别为 (4 9 2 5± 7 0 6 )min和(6 2 4 0± 9 90 )min ,差异有显著性意义 (P <0 0 1)。结论 :控制性降压可明显减少术中出血 ,缩短手术时间。  相似文献   
158.
目的 了解深圳口岸入出境人员乙型肝炎病毒感染情况.方法 采用酶联免疫吸附试验(ELISA)检测受检人员血清HBsAg,并分析比较各类人员的HBsAg阳性率. 结果本次受检人员HBsAg阳性率为9.61%,其中台湾籍人员的HBsAg阳性率最高(为13.80%),其次是香港籍人员(10.94%)和交通员工(10.47%)以及大陆出国人员(6.99%),外籍人员最低,仅2.80%. 结论我国乙型肝炎病毒感染率仍较高,要注意加强乙肝知识的宣传,强化乙肝有防治和监测.  相似文献   
159.
Summary To investigate the distribution of possible novel mutations from parkin gene in variant subset of patients with Parkinson’s disease (PD) in China and explore whether parkin gene plays an important role in the pathogenesis of PD, 70 patients were divided into early-onset group and late-onset group; 70 healthy subjects were included as controls. Genomic DNA from 70 normal controls and from those of PD patients were extracted from peripheral blood leukocytes by using standard procedures. Mutations of parkin gene (exon 1–12) in all the subjects were screened by PCR-single strand conformation polymorphism (SSCP), and further sequencing was performed in the samples with abnormal SSCP results, in order to confirm the mutation and its location. A new missense mutation Gly284Arg in a patient and 3 abnormal bands in SSCP electrophoresis from samples of another 3 patients were found. All the DNA variants were sourced from the samples of the patients with early-onset PD. It was concluded that Parkin point mutation also partially contributes to the development of early-onset Parkinson’s disease in Chinese. WANG Tao, male, born in 1961, Associate Professor This work was supported by grants from the key program of the special scientific project of Scientific & Technologic Agency of Hubei Province (Serial No. 2001AA308B01) and the Hygienic Research Project of Hygienic Agency of Hubei province (Serial No. WJ 01529).  相似文献   
160.
城市一般人群艾滋病相关知识、态度及其影响因素调查   总被引:29,自引:1,他引:28  
目的 了解城市一般人群对艾滋病知识的认识、态度情况。以确定城市一般人群艾滋病知识水平及其影响因素,为今后在一般人群中采取针对性的艾滋病知识宣传策略提供依据。方法 于2002年12月1日在广州市商业区采用街头随机拦截的方式,对一般人群采用匿名自填问卷的方法调查其艾滋病相关知识和态度。结果 本次调查共发放问卷200份,收回有效问卷147份。结果显示,艾滋病知识总知晓率为63.3%;传播途径知识总知晓率为59.2%;预防知识知晓率为46.9%;对艾滋病感染/患正确态度率为49.7%。多因素Logistic回归分析显示,艾滋病知识知晓率的影响因素为年龄、性别、化程度和婚姻状况。30~39岁年龄组(OR=0.101,95%CI:0.015~0.678)和40岁及以上年龄组(OR=0.060,95%CI:0.007~0.498)艾滋病知识总知晓率低于15~20岁年龄组;女性艾滋病知识知晓率(OR=0.230,95%CI:0.099~0.532)低于男性;化程度初中(OR=14.161。95%CI:2.195~91.364)、高中(OR=23.455,95%CI:4.568~120.434)、大专以上(OR=35.378,95%CI:6.001~208.571)艾滋病知识知晓率高于小学及以下组;已婚(OR=5.761,95%CI:1.589~20.893)高于未婚。结论 目前城市一般人群的艾滋病知识水平仍然很低,因此应进一步加强对一般人群的艾滋病知识的宣传,尤其是针对化程度低、未婚及女性人群开展艾滋病知识的宣传教育。  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