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   46808篇
  免费   3711篇
  国内免费   74篇
耳鼻咽喉   445篇
儿科学   1614篇
妇产科学   1177篇
基础医学   6263篇
口腔科学   925篇
临床医学   5808篇
内科学   8380篇
皮肤病学   634篇
神经病学   4448篇
特种医学   1223篇
外国民族医学   1篇
外科学   6167篇
综合类   862篇
一般理论   94篇
预防医学   5758篇
眼科学   853篇
药学   2624篇
中国医学   23篇
肿瘤学   3294篇
  2023年   396篇
  2022年   629篇
  2021年   1324篇
  2020年   821篇
  2019年   1284篇
  2018年   1413篇
  2017年   1032篇
  2016年   1062篇
  2015年   1154篇
  2014年   1633篇
  2013年   2255篇
  2012年   3348篇
  2011年   3327篇
  2010年   1820篇
  2009年   1504篇
  2008年   2625篇
  2007年   2642篇
  2006年   2599篇
  2005年   2528篇
  2004年   2261篇
  2003年   1990篇
  2002年   1789篇
  2001年   665篇
  2000年   662篇
  1999年   638篇
  1998年   468篇
  1997年   313篇
  1996年   294篇
  1995年   255篇
  1994年   250篇
  1993年   239篇
  1992年   502篇
  1991年   424篇
  1990年   402篇
  1989年   378篇
  1988年   374篇
  1987年   332篇
  1986年   349篇
  1985年   355篇
  1984年   283篇
  1983年   285篇
  1982年   223篇
  1981年   247篇
  1980年   200篇
  1979年   288篇
  1978年   227篇
  1977年   182篇
  1975年   170篇
  1974年   204篇
  1973年   214篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
This study examined the use and effectiveness of the Alert assessment form. The form is part of the Alert system, used by one large acute care hospital to identify patients with a propensity for violence. All reported incidents of patient violence from August 1, 2003, through December 31, 2004, were included in patient charts. One hundred seventeen violent patient charts were reviewed and compared with 161 non-violent patient charts, randomly chosen from the same time period. Overall use of the Alert assessment form for violent and non-violent patients was 75.7% and 35.4%, respectively. The assessment form was found to have moderate sensitivity (71%) and high specificity (94%). It is reasonably effective in identifying potentially violent or aggressive patients when it is used according to protocol. Efforts to improve the tool are warranted, as is evaluation of its benefit in settings with low prevalence of violence. Also, greater effort must be taken to prevent violence once an aggressive patient has been identified.  相似文献   
72.
Hurricanes Katrina and Rita forced many individuals along the coast of Texas and Louisiana to seek shelter inland. Among the evacuees were residents with special needs and residents of nursing homes and group homes caring for mentally retarded and physically disabled persons. Many nurses volunteered to provide health care for those in need. This article discusses challenges and opportunities that were encountered by nurses volunteering in special-needs shelters. Issues related to human and physical resources, patient care, and confidentiality are discussed including lessons learned. As nurses who cared for evacuees in the shelter, it is hoped some of the lessons learned can be utilized in future disasters.  相似文献   
73.
The significance of life stress, coping, and social support was examined in relation to depressive symptomatology in a sample of 160 asymptomatic and mildly symptomatic HIV-antibody-positive (HIV+) men. The participants (mean age = 32 years) were interviewed about the life stress that they had experienced in the previous 6  相似文献   
74.
Risk Factors for a First Febrile Seizure: A Matched Case-Control Study   总被引:10,自引:6,他引:4  
Summary We conducted a matched casecontrol study to identify risk factors for first febrile seizures, with special emphasis on characteristics of the acute illness episode. Cases were identified through hospital emergency departments; controls were identified through outpatient clinics and emergency departments. Sixtynine children with first febrile seizures and no history of previous unprovoked seizures were matched for age (±6 months), site of routine pediatric care, and date of visit (±weeks) with 1 or 2 febrile controls who had no history of previous febrile or unprovoked seizures. Medical records for the index visit were reviewed, and parents were interviewed by telephone. Illness characteristics examined included height of temperature, type of underlying illness, contact with a physician during the illness but before the index visit, and use of acetaminophen or decongestants. Family history of febrile and of unprovoked seizures, sociodemographic characteristics, daycare use, and selected preand perinatal variables were also studied. On multivariable analysis, significant independent risk factors were height of temperature, history of febrile seizures in a firstor in a higher degree relative. Gastroenteritis as the underlying illness had a significant inverse (i.e., protective) association with febrile seizures. Maternal smoking during pregnancy was a marginally significant predictor of febrile seizures.  相似文献   
75.
PURPOSETo demonstrate the spectrum of CT and MR imaging findings in patients with Wegener granulomatosis and to determine how often these findings could be attributed to either direct extension from paranasal or orbital disease sites, remote granulomas, or central nervous system (CNS) vasculitis.METHODSWe retrospectively reviewed the CT or MR studies of 15 patients with Wegener granulomatosis.RESULTSAbnormal findings were seen in 7 patients (5 examined with MR imaging, 2 with CT). Findings included dural thickening and contrast enhancement (3 patients), infarcts (2 patients), regions of hyperintense signal on T2-weighted MR images (2 patients), and abnormal MR signal in the brain stem (2 patients). Three patients with imaging findings of dural enhancement and thickening were thought to have remote granulomatous lesions involving the dura. No patients had extension from sites external to the CNS or clinical findings suggestive of CNS vasculitis.CONCLUSIONThe spectrum of CT and MR findings in Wegener granulomatosis includes dural thickening and enhancements cerebral infarction, and MR signal abnormalities in the brain stem and white matter. Presumed remote granulomatous lesions were the most common causes of CNS findings in this study. Complications related to non-CNS disease (eg, hypertension, endocarditis) also appear to have played a role in some patients.  相似文献   
76.
77.
A novel chiral redox-active ferrocene compound (FcVI) with amphiphilic properties has been synthesized. Cryogenic Transmission Electron Microscopy (cryo-TEM) has been used to estimate the shape and size of the FcVI aggregates in solution. Uni- and multi-lamellar vesicles (between 40 and 300 nm in diameter) were observed in water. Large particles (of more than 1 μm in diameter) with a hexagonal fine structure were found in 50 mM aqueous Na2SO4 solution. Sonication transformed the latter into ‘rosette’-like structures. Cyclic voltammetry has been employed to investigate the electrochemical properties of FcVI. The amphiphile adsorbed on graphite electrodes and a reversible electrochemical behaviour, characteristic of ferrocene, was observed with redox potentials between 330 and 350 mV.  相似文献   
78.
Four patients between 58 and 81 years of age undergoing investigation and endoscopic biopsy for gastric carcinoma also were subjected to direct-vision fine needle aspiration cytology of their mucosal lesions which yielded malignant cells. The relevance of this technique is discussed regarding both intrinsic and extrinsic lesions of the gastrointestinal tract.  相似文献   
79.
80.
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