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   50725篇
  免费   4552篇
  国内免费   892篇
耳鼻咽喉   251篇
儿科学   2360篇
妇产科学   819篇
基础医学   5102篇
口腔科学   995篇
临床医学   6674篇
内科学   7903篇
皮肤病学   691篇
神经病学   809篇
特种医学   813篇
外国民族医学   1篇
外科学   5796篇
综合类   7286篇
现状与发展   7篇
预防医学   10049篇
眼科学   294篇
药学   4162篇
  41篇
中国医学   1019篇
肿瘤学   1097篇
  2024年   146篇
  2023年   925篇
  2022年   1845篇
  2021年   2416篇
  2020年   2469篇
  2019年   1941篇
  2018年   1876篇
  2017年   1842篇
  2016年   1992篇
  2015年   2145篇
  2014年   3490篇
  2013年   3982篇
  2012年   3476篇
  2011年   3547篇
  2010年   2520篇
  2009年   2329篇
  2008年   2202篇
  2007年   2251篇
  2006年   2160篇
  2005年   1887篇
  2004年   1557篇
  2003年   1338篇
  2002年   964篇
  2001年   877篇
  2000年   718篇
  1999年   672篇
  1998年   539篇
  1997年   499篇
  1996年   435篇
  1995年   418篇
  1994年   387篇
  1993年   325篇
  1992年   294篇
  1991年   275篇
  1990年   198篇
  1989年   207篇
  1988年   157篇
  1987年   127篇
  1986年   100篇
  1985年   138篇
  1984年   86篇
  1983年   70篇
  1982年   77篇
  1981年   63篇
  1980年   41篇
  1979年   40篇
  1978年   25篇
  1977年   25篇
  1976年   33篇
  1975年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Conclusion Reviewing the history of diagnostic procedures of causative organisms of respiratory infections, invasive techniques such as the protected specimen catheter (PSB) and bronchoalveolar lavage (BAL) have become the preferred choices because they have many advantages. These methods cause the patient relatively little discomfort, and permit an early diagnosis since they can easily be performed at the bedside and the causative organism from the disease site is obtained in cultures. These procedures can be used not only in patients with community-acquired lung infections, but also in immunocompromised hosts, including those with blood diseases or following renal transplantation, in patients in intensive care units and in mechanically-ventilated patients so that the cause can be accurately determined and chemotherapy started quickly, resulting in better therapeutic efficacy. Although these invasive procedures are advantageous for the diagnosis of respiratory infections, they also present various problems which remain to be addressed including minimizing contamination and setting diagnostic threshold values. However, the importance of accurately determining the causative organism in respiratory infections should be recognized as the most important factor, and these methods have shown to date to provide the most accurate information to aid in the timely treatment of respiratory infections in a wide variety of patients.  相似文献   
92.
A case of actinomycotic brain infection in a juvenile patient is described. Cases of actinomycosis affecting the head and neck are rare, particularly in juvenile patients. In this case complete resolution of the infection was achieved by means of surgical treatment and prolonged antibiotic therapy. The authors emphasize the importance of a combined approach for treatment of this unusual brain infection and stress the difficulties involved in the diagnosis of this pathology. Received: 3 November 1997  相似文献   
93.
Congenital endophthalmitis following maternal shellfish ingestion   总被引:1,自引:0,他引:1  
Purpose: To highlight an unusual organism causing a unilateral endophthalmitis by transplacental spread.
Method: We report a case of Plesiomonas shigelloides endophthalmitis, presenting in a newborn, with co-existing septicaemia and meningitis. There was a significant maternal history of diarrhoea associated with the ingestion of oysters 2 weeks prior to delivery.
Result: The endophthalmitis was treated with parenteral antibiotics and topical mydriatics with complete resolution, although subsequent assessment of the affected eye suggests a poor visual outcome.
Conclusion: Endophthalmitis in the newborn is an unusual clinical finding and usually presents with other manifestations of bacteraemia. Plesiomonas shigelloides is fortunately an infrequent cause of neonatal infection, but is associated with a high degree of morbidity and mortality. We postulate that this neonate acquired P. shigelloides via the transplacental route, and suggest that this organism be included in the list of 'other' causes of transplacental infection that has been abbreviated to 'O' in the acronym TORCH.  相似文献   
94.
OBJECTIVE: Our purpose was to determine whether the incidence of postoperative endometritis and wound infection is associated with the method of placental removal at the time of cesarean section.STUDY DESIGN: Parturients undergoing cesarean delivery were prospectively randomized to have the placenta removed manually or spontaneously. Patients were excluded from participation if they had received intrapartum prophylactic antibiotics or had been determined to have chorioamnionitis. After delivery of the infant women in the manual group had the placenta extracted by the primary surgeon, whereas women in the spontaneous group had the placenta delivered by gentle traction on the umbilical cord. All study subjects received perioperative prophylactic antibiotics. The primary outcome variable was a postcesarean infection, defined as postcesarean endometritis or wound cellulitis requiring drainage and antibiotic therapy.RESULTS: A total of 333 women were enrolled in the investigation, with 165 assigned to the manual removal group and 168 allocated to have spontaneous removal. There were no statistically significant differences in mean gestational age, frequency or duration of ruptured membranes, frequency or duration of labor, or mean number of vaginal examinations between the two study groups. Postoperative infections occurred in 25 of 168 (15%) women in the spontaneous delivery group compared with 44 of 165 (27%) women in which the placenta was manually extracted (relative risk 0.6, 95% confidence interval 0.4 to 0.9, p = 0.01). Subset analysis of patients delivered with ruptured membranes similarly demonstrated a statistically significant reduction in the incidence of postoperative infections with spontaneous placental removal compared with manual extraction (20% vs. 38%, relative risk 0.5, 95% confidence interval 0.3 to 0.9, p = 0.02). There was a similar trend toward a reduction in postdelivery infections associated with spontaneous placental removal in women with intact membranes; however, this difference did not attain statistical significance.CONCLUSIONS: Spontaneous delivery of the placenta after cesarean delivery is associated with a decrease in the incidence of postcesarean infections. (Am J Obstet Gynecol 1997;176:1250-4.)  相似文献   
95.
呼吸道感染是呼吸系统常见病、多发病。利用杭州地区1990年1月~1992年12月气象资料作了统计分析,并对同期来海军杭州疗养院门诊就诊的呼吸道感染病人进行了调查。结果为1~3、11、12月发病率高,与5~9月相比有非常显著差异(P<0.001),呼吸道感染与气温低,湿度高,温差大,天气骤变等气象因素密切相关。潮冷天气(气温在10℃以下),频繁降温(每月3次以上),大幅度降温(4℃以上)三种气象因素共同存在情况下可导致呼吸道感染性疾病的高发。同时从气象学角度提出了预防该病的一些措施。  相似文献   
96.
This case report describes infantile nephrotic syndrome (NS) in a baby girl with a clinically severe cytomegalovirus (CMV) infection. Culture of the baby's urine was positive for CMV and IgM anti-CMV antibodies were detected. After an unsuccessful course of corticosteroids, gancyclovir treatment was started and a remission of cutaneous, pulmonary, and renal symptoms was achieved. As the mother also developed NS at the end of pregnancy, a common etiology could be postulated, although there were no signs of recent CMV infection in the mother, only anti-CMV IgG. The relationship between CMV infection and glomerular disease is still unclear: NS may represent another manifestation of CMV disease.  相似文献   
97.
为探讨孕妇乙型肝炎病毒(HBV)感染和某些因素对先天性畸形的致病作用,本文进行了96对新生儿先天畸形的配对(1:1)病例对照研究,报道先天畸形的频率和构成,单因素和多因素的条件Logistic回归分析,表明孕妇HBsAg阳性等6个因素对先天畸形呈阴性结果,而与接触农药和孕周的因素有明显联系,值得进一步探讨。  相似文献   
98.
为加强医院感染控制,开展医院感染控制继续教育,本介绍了医院感染控制多媒体软件的设计与应用,为有效预防和控制医院感染,促进医院感染控制的进展,把感染管理工作推上新的台阶提供参考。  相似文献   
99.
The MIC values of the antifungal drug ketoconazole were evaluated on 66 Candida albicans strains. These strains were isolated from 26 HIV-1 infected patients with oral recurrent candidosis. Each episode of oral candidosis observed in these patients was orally treated with ketoconazole (200 mg/day) until the clinical disappearance of the lesions. The most frequent MIC values were 20 micrograms/ml and 10 micrograms/ml, observed in 37 and 19 isolates respectively. Only strains from five patients showed changes in their susceptibility to ketoconazole. This fact could indicate that a different strain causes the subsequent reappearance of the oral lesions, rather than the drug selecting resistant fungal strains. Our results stress the role of host characteristics in the occurrence of candidal infections, pointing to the progressing failure of the immunological response as the most important factor responsible for the recurrence of oral candidosis during HIV-1 infection.  相似文献   
100.
应用单链构象多态性分析多聚酶链反应EB染色法(PCR-SSCP-EB)对40例肺癌组织标本的P53基因序列5~8外显子突变进行分析,同时应用PCR方法检测上述标本及18例肺良性疾病组织标本中HPV16、18型DNA相关序列,旨在分析二者在肺鳞癌发病中的作用及相互关系,并就肺鳞癌与P53基因结构和功能异常的关系进行初步探讨。  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