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   142989篇
  免费   13791篇
  国内免费   10969篇
耳鼻咽喉   1427篇
儿科学   1388篇
妇产科学   1317篇
基础医学   16148篇
口腔科学   2359篇
临床医学   19045篇
内科学   20376篇
皮肤病学   1682篇
神经病学   7291篇
特种医学   5346篇
外国民族医学   84篇
外科学   14417篇
综合类   26658篇
现状与发展   51篇
一般理论   7篇
预防医学   10297篇
眼科学   3891篇
药学   15164篇
  137篇
中国医学   9173篇
肿瘤学   11491篇
  2024年   568篇
  2023年   2414篇
  2022年   6195篇
  2021年   7832篇
  2020年   5980篇
  2019年   4903篇
  2018年   5161篇
  2017年   4727篇
  2016年   4399篇
  2015年   6769篇
  2014年   8343篇
  2013年   7638篇
  2012年   10837篇
  2011年   11911篇
  2010年   7805篇
  2009年   6272篇
  2008年   7693篇
  2007年   7497篇
  2006年   7121篇
  2005年   6927篇
  2004年   4559篇
  2003年   4211篇
  2002年   3512篇
  2001年   3050篇
  2000年   3121篇
  1999年   3201篇
  1998年   2111篇
  1997年   2131篇
  1996年   1640篇
  1995年   1553篇
  1994年   1330篇
  1993年   823篇
  1992年   1032篇
  1991年   834篇
  1990年   689篇
  1989年   662篇
  1988年   545篇
  1987年   483篇
  1986年   422篇
  1985年   317篇
  1984年   156篇
  1983年   119篇
  1982年   69篇
  1981年   78篇
  1980年   48篇
  1979年   57篇
  1978年   1篇
  1975年   1篇
  1974年   1篇
  1965年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
内脏高敏感与功能性胃肠病   总被引:3,自引:0,他引:3  
功能性胃肠病(functional gastrointestinal disorders,FGIDs)是指一组以慢性或反复发作的消化道症状就诊,但无明确胃肠黏膜结构改变或生化异常可查的症候群。心理、社会因素可加重FGIDs患者症状,患者可同时伴有躯体症状[1]。其发病机制目前尚不明确,最初该类疾病被认为是胃肠神经官能症,大量的流行病学资料表明,尽管精神压力与患者症状发作有关,但主要还是决定于患者的就医行为。此后,FGIDs发病机制的研究又集中在胃肠动力改变方面,肠易激综合征患者(IBS)、功能性消化不良患者(FD)、非心源性胸痛患者(NCCP)均发现了各种胃肠动力异…  相似文献   
72.
S D Xu 《中华外科杂志》1990,28(10):588-91, 636
108 pigs were shot at the level of lumbar 1 to investigate the changes of spinal cord in relation to the speed of shooting and the trajectory through which the bullet passed. The cord lesions of the specimens could be divided, according to its severity, into 4 grades: (1) transection in 41; (2) complete destruction in 43; both lesion 1&2 resulted in permanent paraplegia; (3) incomplete destruction in 13, those resulted in incomplete paraplegia eventually recovered; (4) mild damage, that was concussion in 11, resumed perfectly. Through a transducer sealed into the spinal canal, the intracanal pressure was recorded: (1) Shooting through spinal canal with a pressure over 5 kg caused cord transection. (2) shooting through canal wall with a pressure of 2.5 to 5; 0 kg caused complete cord destruction. (3) shooting nearby the outer margin of vertebra with a pressure less than 1.0 kg caused mild cord damage. It was found that the speed of bullet, the trajectory with relation to cord and the grade of cord lesion are in agreement with each other. The mutual effects among them would make one think it reasonable to classify cord injury as follows: 1. Injury from bullet through spinal canal or vertebral body usually causes cord transaction; 2. Injury from bullet through canal wall at high speed would make a chance of complete destruction in 94%; at low speed, a chance of either complete or incomplete lesion in 50% each. 3. Injury nearby vertebra, high speed bullet would cause a chance of complete cord lesion in 86%; low speed one would make a chance of incomplete lesion in 1/3 and mild lesion in 2/3.  相似文献   
73.
H T Xu  S L Chen  L S Li 《中西医结合杂志》1990,10(12):737-9, 710
In 24 open-chest mongrel dogs, coronary artery critical stenosis were produced by a micrometer constriction on left circumflex coronary artery. It was reduction about 87% in lumen area. CBF, -Vce, -dp/dt max were decreased, T was increased (P less than 0.01). 15 minutes after stenosis, the Salvia miltiorrhiza injection was injected into left atrium. CBF, -dp/dt max, -Vce were increased and T was decreased after the injection of Salvia miltiorrhiza. Moreover, the change of CBF was the earliest. The results proved that the Salvia miltiorrhiza could improve the left ventricular diastolic function in coronary artery stenosis.  相似文献   
74.
75.
76.
In this paper,250 cases of headache,shoulder pain,lumbago and leg pain weretreated with 20%Angelicae Sinensis mixed with Vitamine B_(12) point-injection therapy.The total effective rate was 95.2%and in which the cure rate was 53.6%.Authors have found a close correlation between the effectiveness and the duration of disease.  相似文献   
77.
护理服务质量的感知与期望分析   总被引:1,自引:0,他引:1  
护理服务质量是一个多维的评价指标。它即有质量部分(技术性、定量),又有非质量部分(功能性、定性),前者是指护理专业的技术水平以及护理工作结果的服务质量,后者是指服务过程的质量,因此护理服务质量不仅取决于医院护理者提供的技术性、定量的技术质量,而且还取决于病人在护理服务过程中感知与期望之间的对比。病人在住院之前对医院护理服务的质量有一个期望,接受了护理服务之后就有了感知,如果病人感知到的护理服务符合期望的护理服务,就会感到满意,如果病人感知到的护理服务高于期望的护理服务,就会感到欣喜,这就是优质护理服务,如果感知…  相似文献   
78.
The tumor microenvironment consists of tumor, immune, stromal, and inflammatory cells which produce cytokines, growth factors, and adhesion molecules that promote tumor progression and metastasis. Of particular interest in this setting is interleukin-1 (IL-1), a pleiotropic cytokine with numerous roles in both physiological and pathological states. It is known to be up regulated in many tumor types and has been implicated as a factor in tumor progression via the expression of metastatic and angiogenic genes and growth factors. A number of studies have reported that high IL-1 concentrations within the tumor microenvironment are associated with a more virulent tumor phenotype. Solid tumors in which IL-1 has been shown to be up regulated include breast, colon, lung, head and neck cancers, and melanomas, and patients with IL-1 producing tumors have generally bad prognoses. The exact mechanisms by which IL-1 promotes tumor growth remain unclear, though the protein is believed to act via induction of pro-metastatic genes such as matrix metalloproteinases and through the stimulation of adjacent cells to produce angiogenic proteins and growth factors such as VEGF, IL-8, IL-6, TNFα, and TGFβ. The IL-1 receptor antagonist (IL-1ra) is a naturally occurring inhibitor to IL-1 and acts by binding to the IL-1 receptor without activating it. The protein has been shown to decrease tumor growth, angiogenesis, and metastases in murine xenograft models. Our focus in this review is to summarize the known data on the role of IL-1 in tumor progression and metastasis and the use of IL-1 inhibition as a novel therapeutic approach in the treatment of solid organ malignancies.  相似文献   
79.
A close or even causal relation between myocardial adenosine and bradyarrhythmias during acute myocardial hypoxia was testified in guinea pig, rabbit and dog mainly by using specific competitive antagonist and synchronous quantitative analysis of 3 variables: intensity of myocardial hypoxia, degree of endogenous adenosine increment and severity of bradyarrhythmias. Results disclosed: A) striking resemblance of the bradyarrhythmias with hypoxic origin to those caused by exogenous adenosine, B) same locality of A-V conduction block induced by both myocardial hypoxia and exogenous adenosine, C) precise parallelism among the above-listed 3 variables with very high correlativity (r = 0.99, P < 0.01), D) frequent accompaniment of reversal of hypoxic bradyarrhythmias through resupply of 21% O2 with normalization of preexisted increase in myocardial adenosine, E) satisfactory blockade of hypoxic bradyarrhythmias by adenosine's specific antagonist--aminophylline and their augmentation by adenosine's uptake inhibitor--dipyridamole, F) close similarity of the characteristic curve representing relation among the above 3 variables to that among intensity of myocardial hypoxia, degree of endogenous adenosine increment and amount of coronary blood flow in which adenosine's role as a mediator has been well documented and G) reproducible persistence of bradyarrhythmias during myocardial hypoxia irrespective of preliminary vagotomy and atropinization, denoting independence of the occurrence of such dysarrhythmias upon vagal drive, suggestive of a mechanism other than vagotonia. We advocated that hypoxia-induced bradyarrhythmias was caused by increment in endogenous adenosine.
  相似文献   
80.
By differentially screening an adult Brugia malayi cDNA library with sera from microfilaremic and amicrofilaremic donors infected with Wuchereria bancrofti, we have identified a novel parasite antigen denoted SXP-1. Recombinant SXP-1 filarial antigen is preferentially recognized by sera from microfilaremic persons with bancroftian filariasis and from skin snip-positive patients with onchocerciasis. Antibodies to SXP-1 are restricted to the IgG4 subclass and gradually decline after treatment with diethylcarbamazine. These findings indicate that it may be possible to replace microscopic examination of night blood films with a serological test designed to detect antibodies to a mix of SXP-1 and other suitable antigens for the diagnosis of microfilaremia due to bancroftian filariasis.  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