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   23096篇
  免费   1320篇
  国内免费   456篇
耳鼻咽喉   305篇
儿科学   543篇
妇产科学   1659篇
基础医学   2500篇
口腔科学   1086篇
临床医学   2365篇
内科学   1791篇
皮肤病学   205篇
神经病学   2626篇
特种医学   837篇
外国民族医学   1篇
外科学   3385篇
综合类   2976篇
预防医学   974篇
眼科学   314篇
药学   1901篇
  7篇
中国医学   725篇
肿瘤学   672篇
  2024年   59篇
  2023年   322篇
  2022年   650篇
  2021年   829篇
  2020年   767篇
  2019年   720篇
  2018年   700篇
  2017年   699篇
  2016年   721篇
  2015年   747篇
  2014年   1294篇
  2013年   1420篇
  2012年   1189篇
  2011年   1339篇
  2010年   1121篇
  2009年   1101篇
  2008年   1068篇
  2007年   1008篇
  2006年   960篇
  2005年   837篇
  2004年   749篇
  2003年   593篇
  2002年   486篇
  2001年   447篇
  2000年   402篇
  1999年   375篇
  1998年   321篇
  1997年   317篇
  1996年   332篇
  1995年   337篇
  1994年   314篇
  1993年   235篇
  1992年   226篇
  1991年   212篇
  1990年   190篇
  1989年   160篇
  1988年   171篇
  1987年   151篇
  1986年   151篇
  1985年   210篇
  1984年   166篇
  1983年   115篇
  1982年   148篇
  1981年   128篇
  1980年   85篇
  1979年   73篇
  1978年   87篇
  1977年   43篇
  1976年   30篇
  1973年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
采用氨基酸自动分析仪检测了18例急性颅脑损伤患者脑脊液中谷氨酸、天门冬氨酸、牛磺酸、甘氨酸、丙氨酸、γ-氨基丁酸、脯氨酸含量的动态变化。结果发现,伤情越重、预后越差的患者,脑脊液中牛磺酸、γ-氨基丁酸、丙氨酸含量伤后早期升高越明显,恢复至正常的时间也越长;其中2例早期死于急性弥漫性脑肿胀、脑水肿的患者,伤后当天脑脊液中牛磺酸含量分别为92.6和51.5μmol/L,是对照值的9.6倍和5.4倍,γ-氨基丁酸含量分别为119.8和246.2μmol/L,是对照值的2.7倍和5.5倍。表明伤后脑脊液中牛磺酸、γ-氨基丁酸和丙氨酸含量的动态变化可初步反映颅脑损伤的严重程度及颅脑损伤患者的脑功能恢复状况,并可能与急性脑水肿、脑肿胀的病理生理过程有关。  相似文献   
72.
Granulocytic sarcoma (GS) is a localized tumour of immature granulocytes that is usually associated with myelogenous leukaemia. We report an unusual case of mastoid GS with meningeal extension but no bone marrow involvement on presentation. Histological examination of the surgical specimen and the characteristic cerebrospinal fluid (CSF) cytology showing cytoplasmic granulations and Auer bodies led to the diagnosis of GS. Positive cytochemical staining of the immature CSF cells for naphtol-ASD chloroacetate esterase and myeloperoxidase confirmed their myeloid origin. Immunophenotyping did not reveal common acute lymphoblastic leukaemia antigen, cytokeratin, T or B-cell antigens. The patient underwent surgical resection of the localized tumour, followed by radiation therapy, intrathecal and systemic chemotherapy, as if he had acute myelogenous leukaemia (AML). He did not develop AML in the 21 months after the tumour resection. This case emphasizes the value of CSF cytological examination of tumour cells and the use of an immumocytochemical marker for differentiating GS from malignant lymphoma.  相似文献   
73.
应用聚合酶链反应(PCR)检测技术对118例颅内感染性疾病患者及37例无神神经系统疾病患者脑脊液(CSF)中的单纯疱疹病毒DNA(HSV-DNA)进行了检测及分型。结果提示:“散发性脑炎”组的阳性率为38.46%(20/52),细菌、真菌性脑膜炎、其它病毒性脑炎组以及无神经系统疾病组均为阴性。作者认为:①本检测是目前单纯疹病毒性脑炎(HSE)较为简便而准确的早期诊断方法之一;②HSV分型检测,对病原诊断更具有全面性;③两型单纯疱疹病毒均可引起HSE。  相似文献   
74.
用改良的ELISA检测25例正常对照组和32例急性脑血管病患者的血清和脑脊液(CSF)中的脑型肌酸激酶同功酶BB(creatine kinase isoenzyme BB)浓度。32例急性脑血管病患者CSF CKBB平均水平为16.62±8.3ng/ml,明显高于对照组(7.5—4.8ng/ml)。发病24h内CSFCKBB轻微增高,24~48h达高峰,以后下降,7天左右尚未恢复正常。病初CSF CKBB水平明显高于恢复期。9例高血压性脑出血的血肿出血量(按CT片上血肿大小计算)与患者CSF CKBB有密切关系(r=0.8127,P<0.01)。血肿体积(X)与CSF CKBB浓度(y)的回归方程y—7.945±0.872X。  相似文献   
75.
应用放射免疫方法联合检测支气管肺泡灌洗液(BALF)、血清、尿液中癌胚抗原(CEA)含量,结果显示:肺癌患者BALF、血清、尿液中CEA均有不同程度的升高,与结核及肺良性疾病组间有显著差异(P<0.01)。其阳性率分别为63.64%,57.38%,27.58%,以BALF阳性率为最高,这对肺癌的诊断及判断预后提供了方便可行的检测手段。  相似文献   
76.
Summary In this report we describe 3 patients with syringomyelia in association with tumours of the posterior fossa. In each patient the syrinx was demonstrated on pre-operative magnetic resonance imaging (MRI). After total or partial removal of the tumour the syrinx collapsed. It is concluded that the pathogenesis of syrinx formation in this entity requires interference with normal cerebrospinal fluid (CSF) flow at the foramen magnum. We suggest that the obstruction to the flow of CSF causes alterations in the passage of extracellular fluid (ECF) in the spinal cord which lead to syringomyelia.  相似文献   
77.
A 37 year old male was admitted with the diagnosis of bacterial meningitis. Pneumococci were seen in the Gram stain of the cerebrospinal fluid. The clinical condition did not suggest severely raised intracranial pressure, there were no localizing signs and symptoms. CSF was turpid, with 20.100/3/mm3, mainly polymorphonuclear cells. Tumor necrosis factor alpha in CSp was greatly increased with 813 pg/ml. Parallel to the application of intravenous Penicillin G a CSF filtration was carried out. Within 214 h 225 ml CSF were filtrated through a Pall-filter, using a bidirectional pump. Cell count dropped to 720/3 cells/mm3, TNF-alpha to 39 pg/ml. The clinical course was uneventful, on day 12 the patient could be discharged without sequelae. CSF filtration may be a highly effective method to reduce from the CSF pathogenetically important cytokines, such as TNF-alpha, being responsible for intrathecal/meningeal inflammatory processes and triggered by cell-wall components of bacteria, e.g. pneumococci.  相似文献   
78.
The neurochemistry of Alzheimer's disease   总被引:1,自引:0,他引:1  
Our knowledge of the neurochemical pathology of AD has increased immensely the last years. Although it is now clear that mutations in the APP gene can cause some rare hereditary forms of AD, and that ApoE4 is a prominent risk factor for AD, we at present know little about the underlying cause of AD in the general population and the biochemical mechanisms by which the apolipoprotein E4 isoform affects AD pathogenesis. It is hoped that the near future will see a resolution of the current controversies in AD research, including: 1) whether APP mutations cause Alzheimer's disease by affecting Aβ deposition or the function of APP itself; 2) whether abnormal phosphorylation of tau is a central pathogenetic event, or whether it occurs as epiphenomena that reflect general neurodegeneration in a variety of disease processes; 3) Whether Aβ deposition in the brain is the central event in AD or whether it occurs as epiphenomena in a variety of brain disorders such as head trauma; and 4) whether altered tau phosphorylation occurs secondary to Aβ deposition or vice versa, and what the link is (if any) between the two processes.  相似文献   
79.
BACKGROUND: Patients with diabetes mellitus have a high incidence of coronary heart disease and congestive heart failure (CHF). Thiazolidinediones (TZD) are a new class of pharmacological agents for the treatment of Type 2 diabetes mellitus, which have many beneficial cardiovascular effects. Peripheral oedema and weight gain have been reported in 4.8% of subjects on TZDs alone, with a higher incidence noted in those receiving combination insulin therapy (up to 15%), but there is limited data on the occurrence of CHF. METHODS AND RESULTS: In this paper, we report on six cases of TZD-induced fluid retention with symptoms and signs of peripheral oedema and/or CHF that occurred in subjects attending our diabetic clinic. The predominant finding in all cases was of diastolic dysfunction. All subjects were obese and hypertensive, with 5/6 having the additional risk factor of LVH, 5/6 subjects had microvascular complications, whilst 3/6 were also on insulin therapy. CONCLUSION: We suggest that obese, hypertensive diabetics may benefit from echocardiographic screening prior to commencement of TZDs, as these agents may exacerbate underlying undiagnosed left ventricular diastolic dysfunction.  相似文献   
80.
中西医结合治疗慢性盆腔炎100例疗效观察   总被引:2,自引:1,他引:1  
目的:采用中西医结合治疗慢性盆腔炎,减少复发,提高治愈率。方法:对我院门诊患者100例采用胎盘组织液肌注,金钢藤胶囊口服,并用我院自制中药妇炎肠疗液灌肠。结果:临床显效40例,有效56例,无效4例,总有效率96%。结论:中西医结合治疗慢性盆腔炎疗效满意,是目前治疗慢性盆腔炎的最好方法。  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