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   121726篇
  免费   10390篇
  国内免费   5896篇
耳鼻咽喉   1445篇
儿科学   1717篇
妇产科学   2782篇
基础医学   14760篇
口腔科学   2349篇
临床医学   14505篇
内科学   20101篇
皮肤病学   1848篇
神经病学   6513篇
特种医学   4487篇
外国民族医学   46篇
外科学   14312篇
综合类   14785篇
现状与发展   25篇
一般理论   25篇
预防医学   7806篇
眼科学   3046篇
药学   11580篇
  85篇
中国医学   5132篇
肿瘤学   10663篇
  2024年   259篇
  2023年   1279篇
  2022年   3083篇
  2021年   5233篇
  2020年   3586篇
  2019年   3493篇
  2018年   4023篇
  2017年   3323篇
  2016年   3217篇
  2015年   5109篇
  2014年   6257篇
  2013年   6306篇
  2012年   9026篇
  2011年   9377篇
  2010年   6234篇
  2009年   5237篇
  2008年   6685篇
  2007年   6683篇
  2006年   6517篇
  2005年   6139篇
  2004年   5034篇
  2003年   4768篇
  2002年   4021篇
  2001年   3274篇
  2000年   2944篇
  1999年   2691篇
  1998年   1446篇
  1997年   1312篇
  1996年   1042篇
  1995年   1042篇
  1994年   900篇
  1993年   564篇
  1992年   1075篇
  1991年   914篇
  1990年   818篇
  1989年   732篇
  1988年   623篇
  1987年   612篇
  1986年   488篇
  1985年   408篇
  1984年   294篇
  1983年   228篇
  1982年   136篇
  1981年   147篇
  1980年   107篇
  1979年   225篇
  1978年   161篇
  1977年   104篇
  1976年   111篇
  1975年   102篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
原位杂交法检测BP1基因在乳腺癌组织中表达   总被引:3,自引:0,他引:3  
目的探讨BP1同源盒基因在乳腺癌中的表达及其与临床病理指标的关系。方法收集165例乳腺癌临床和病理资料,采用原位杂交法检测BP1的表达,同时用二步法进行ER、p53、PCNA、bcl2、cerbB2免疫组化染色。结果BP1基因表达率为67.88%,免疫组化:ER70.30%、p5349.09%、PCNA74.55%、bcl253.33%、cerbB275.52%。BP1与bcl2具有相关性(P<0.01),且均与ER相关(P<0.05),与p53呈负相关(P<0.05)。BP1与PCNA、cerbB2、患者年龄、组织学类型、淋巴结转移等无相关性。结论BP1可能通过某种非依赖p53基因调控机制,与bcl2、ER协同抑制肿瘤细胞的凋亡而参与乳腺癌的发生。  相似文献   
132.
BACKGROUND AND PURPOSE: This study investigated the characteristics of intussusception in Taiwanese children of different age groups, including the incidence, length of hospitalization and hospital costs. METHODS: Children with a diagnosis of intussusception who were hospitalized from 1999 through 2001 were identified from a nationwide health insurance claims database. The incidence of intussusception was calculated by age, gender, and season. Length of hospitalization and hospital costs were also analyzed. RESULTS: A total of 6988 cases of intussusception were identified in Taiwan from 1999 to 2001. Among them, 4859 cases occurred in children below 15 years of age. The average incidence among children below age 15 years was 34.5 per 100,000, with a peak incidence of 118.8 per 100,000 observed among children younger than 24 months old. The highest incidence of intussusception in Taiwanese children occurred between 12 and 24 months of age. According to the data for patients below 15 years of age hospitalized for intussusception in year 2000, males were more likely to be affected than females (61.3% vs 38.7%). Intussusception-related hospitalizations were rare in infants in the first few months of life, increased in those 6 to 12 months old, and peaked among children 1 to 3 years old. Among the 952 patients with intussusception admitted to hospitals in 2000, 297 (31.2%) received surgery, incurring higher median medical costs (New Taiwan Dollars [NT dollars] 42,265 or US dollars 1234) and longer median hospital stay (6.2 days) than the 655 patients who did not require surgery (NT dollars 6290 or US dollars 185 for hospitalization of 2.4 days). CONCLUSIONS: The study found that the incidence of intussusception peaked in the second year of life in Taiwanese children. There was also a male predominance and lack of seasonal variation in incidence.  相似文献   
133.
Tumor metastasis to the pancreas is a rare but recognized cause of acute pancreatitis. Autopsy series have reported a 24-40% of pancreatic involvement in small cell lung cancer. However, only a very few cases of tumor-induced acute pancreatitis have been described. Budd-Chiari syndrome complicating lung cancer is a rarely reported condition. We report a 68-year-old woman with extensive small cell lung cancer with the unusual initial presentation of both acute pancreatitis and acute Budd-Chiari syndrome. This patient suffered from progressive epigastralgia for 3 weeks. Severe epigastralgia with radiation to back and progressive jaundice developed 2 days prior to admission. After admission, the liver enlarged rapidly and the ascites increased markedly. Chest roentgenogram showed a mass lesion over the left lower lung field. Poorly differentiated carcinoma cells were found in ascites and bone marrow. The patient died on the ninth day of hospitalization before chemotherapy was initiated. Prompt diagnosis of extensive-stage small cell lung cancer may allow early chemotherapy treatment which favorably influences recovery when the pancreatitis is mild. Although prolonged survival might have been expected had this patient recovered from pancreatitis and received chemotherapy, diagnosis was delayed due to difficulty in immunohistochemical diagnosis of the tumor and the unusual clinical presentation. The use of stains employing antibodies against neurofilament and neuron-specific enolase cell antigens is important for early diagnosis of poorly differentiated metastatic tumor cells.  相似文献   
134.
Following an encephalopathic illness, a 13-year-old Chinese boy had a partial form of Klüver-Bucy syndrome with emotional disturbance, recent memory loss, hypersexuality, and polyphagia. Other unusual features included narcolepsy, polydipsia, and polyuria. Virologic studies failed to incriminate the etiologic agent, including herpes simplex virus. Brain biopsy of the frontal lobe demonstrated Alzheimer type II astrocytosis.  相似文献   
135.
1. A new premercapturic acid metabolite of bromobenzene was isolated from the urine of beta-naphthoflavone-induced rats; using 1H-n.m.r., FAB mass spectrometry and chemical degradation it was identified as S-(2-hydroxy-3-bromocyclohexa-3,5-dienyl)-N-acetylcysteine. 2. Two regioisomeric premercapturic acids apparently derived from bromobenzene-3,4-oxide were isolated as an inseparable 1:1 mixture from the urine of phenobarbital-induced rats and characterized by similar means. 3. Acid dehydration of bromobenzene 3,4- and 4,3-premercapturic acids (mixture) afforded only p-bromophenylmercapturic acid, whereas acid dehydration of 3,2-premercapturic acid gave both o- and m-bromophenylmercapturic acids. This implies a shift of sulphur in acid dehydration of the 3,4- and 3,2- but not the 4,3-premercapturic acids. 4. Base dehydration of the 3,4- and 4,3-premercapturic acid mixture gave a mixture of p- and m-bromophenylmercapturic acids, whereas base dehydration of the 3,2-premercapturic acid gave only m-bromophenylmercapturic acid. This indicates these premercapturic acids dehydrate by direct elimination without rearrangment. 5. The 3,2-premercapturic acid was detected only in the urine of BNF-induced animals, whereas the 3,4- and 4,3-premercapturic acids were detected in the urines of untreated as well as PB- and BNF-induced animals. 6. Together with earlier reports of the isolation of the 2,3-dihydrodiol, the isolation of the 3,2-premercapturic acid as a urinary metabolite of bromobenzene implies that bromobenzene-2,3-oxide is a discrete metabolite of bromobenzene and not merely a hypothetical intermediate.  相似文献   
136.
The present study investigated the role of central metabotropic glutamate receptors (mGluRs) in interleukin-1beta (IL-1beta)-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Experiments were carried out on male Sprague-Dawley rats weighing 230 to 280 g. After administration of 0.01, 0.1, 1, or 10 pg of IL-1beta into a subcutaneous area of the vibrissa pad, we examined the withdrawal behavioral responses produced by 10 successive trials of an air-puff ramp pressure applied ipsilaterally or contralaterally to the IL-1beta injection site. Subcutaneous injection of IL-1beta produced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Intracisternal administration of CPCCOEt, a mGluR1 antagonist, or MPEP, a mGluR5 antagonist, reduced IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. Intracisternal administration of APDC, a group II mGluR agonist, or L-AP4, a group III mGluR agonist, reduced both IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia. The antiallodynic effect, induced by APDC or L-AP4, was blocked by intracisternal pretreatment with LY341495, a group II mGluR antagonist, or CPPG, a group III mGluR antagonist. These results suggest that groups I, II, and III mGluRs differentially modulated IL-1beta-induced mechanical allodynia, as well as mirror-image mechanical allodynia, in the orofacial area. PERSPECTIVE: Central group I mGluR antagonists and groups II and III mGluR agonists modulate IL-1beta-induced mechanical allodynia and mirror-image mechanical allodynia in the orofacial area. Therefore, the central application of group I mGluR antagonists or groups II and III mGluR agonists might be of therapeutic value in treating pain disorder.  相似文献   
137.
郑慧瑛  姚晶星  方颖 《护理研究》2006,20(4):359-359
手术中常用体位垫来调整体位及预防褥疮,但以往使用的软垫、海绵垫等却不可根据手术及术中的要求来调节高度,我科对其进行研究并利用现有材料,将其改进制成可调节型充气体位垫,投入临床试用,效果较好。现介绍如下。1材料与制作取上海百特医疗用品有限公司生产的3L容量的氯化钠溶液软包装袋一个,将其中一个出口封闭,使其不漏气。将一根长30cm~50cm长的橡胶管固定于另一个出口,使其不漏气,并将输血器调节器穿于橡胶管上,调节滚轴,起开关作用。连接气压止血器充气,即成可调节型充气调节体位垫。2使用方法根据手术要求将橡胶管连接于气压止血器…  相似文献   
138.
喉癌患者术后的适应性研究   总被引:2,自引:0,他引:2  
李菁  李峥 《护理学杂志》2006,21(14):75-78
喉癌是头颈部最常见的恶性肿瘤,目前手术仍是治疗喉癌的主要手段.通过对喉癌术后患者的适应状态、适应测量及影响适应的因素进行综述,提出对喉癌术后适应干预的研究应该针对患者的年龄与性别、个性特征提供不同的应对、治疗方式、术后时间、社会支持和信息等方面知识.  相似文献   
139.
S C Chang  G M Shiao  R P Perng 《Chest》1989,96(1):60-63
The effect of body position (right and left lateral decubitus positions) on arterial oxygen tension (PaO2) and the relationship between this postural effect on gas exchange and pulmonary function were evaluated in 21 patients who had unilateral pleural effusions without roentgenographic and bronchoscopic evidence of bronchopulmonary disorders. Our results indicated that a positional influence on gas exchange existed in these patients. We failed to find a consistent relationship between the size of effusion estimated by chest roentgenogram and alterations in PaO2 during different positions. Postural change did affect gas exchange in the patients with unilateral pleural effusions and this postural effect on gas exchange was highly correlated with their FEV1 and FVC. This may be of clinical significance in managing such patients.  相似文献   
140.
1例脊髓空洞症侧脑室延髓池内分流术的护理   总被引:1,自引:0,他引:1  
唱荣艳  陈荣莉  薛艳娥 《护理研究》2005,19(30):2819-2819
1 病例介绍病人,男,34岁,左下肢步态不稳10年,加重伴酸麻、隐痛1年,于2004年4月入院.入院时精神欠佳,生活不能完全自理,左上肢肱二腱、肱三腱反射和下肢膝反射亢进,右上肢肱二腱、肱三腱反射减弱,右前臂及手部触觉消失,左下肢膝关节以下触觉、位置觉、浅感觉消失.MRI示脊髓空洞症.术前检查未发现手术禁忌证,行全身麻醉下环枕畸形减压、侧脑室延髓池内分流术.手术顺利,术中输红细胞悬液400 mL,放置皮下引流管1根,术后恢复好,无并发症发生,病人生活上基本自理,出院随访1年,情况良好.……  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