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   17331篇
  免费   985篇
  国内免费   154篇
耳鼻咽喉   133篇
儿科学   377篇
妇产科学   595篇
基础医学   2052篇
口腔科学   449篇
临床医学   1392篇
内科学   4419篇
皮肤病学   301篇
神经病学   1844篇
特种医学   729篇
外科学   2597篇
综合类   50篇
一般理论   1篇
预防医学   559篇
眼科学   308篇
药学   1035篇
中国医学   24篇
肿瘤学   1605篇
  2024年   15篇
  2023年   169篇
  2022年   185篇
  2021年   611篇
  2020年   391篇
  2019年   491篇
  2018年   609篇
  2017年   414篇
  2016年   496篇
  2015年   563篇
  2014年   779篇
  2013年   910篇
  2012年   1392篇
  2011年   1400篇
  2010年   768篇
  2009年   703篇
  2008年   1126篇
  2007年   1115篇
  2006年   1070篇
  2005年   976篇
  2004年   940篇
  2003年   806篇
  2002年   688篇
  2001年   166篇
  2000年   169篇
  1999年   182篇
  1998年   166篇
  1997年   119篇
  1996年   120篇
  1995年   107篇
  1994年   79篇
  1993年   65篇
  1992年   95篇
  1991年   93篇
  1990年   52篇
  1989年   56篇
  1988年   43篇
  1987年   42篇
  1986年   45篇
  1985年   33篇
  1984年   41篇
  1983年   35篇
  1982年   26篇
  1981年   18篇
  1980年   10篇
  1976年   8篇
  1973年   7篇
  1971年   8篇
  1970年   10篇
  1969年   8篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
With easy chemical synthesis from its precursor, methamphetamine (MA) is now widespread in many countries. The abuse of methamphetamine is associated with several negative effects on health, because MA is a neurotoxin and a dangerous central nervous system stimulant. It changes levels of neurotransmitters in the brain, releasing dopamine and inhibiting nor epinephrine uptake which increases sympathetic nervous system activity and can lead to cardiac arrhythmia, hypertension and tachypnea. The consequences of MA abuse are clearly manifested in oral diseases (like “meth mouth”) which is characterised by extensive caries, teeth grinding with ensuing dental wear and trismus. The present review was designed to fill the gap in knowledge about methamphetamine abuse in the European Union (EU) and to illustrate the main clinical effects of prolonged use. After describing the pharmacology and systemic effects of methamphetamine and concentrating on its effects on the mouth, the present review compares the epidemiology and incidence of abuse in the world, particularly the USA and the EU. Key words:Methamphetamine, “Meth mouth”, drug abuse, oral health.  相似文献   
2.
3.
4.
5.
6.
7.
8.
Although the rate of patients reporting satisfaction is generally high after joint replacement surgery, up to 23% after total hip replacement and 34% after total knee arthroplasty of treated subjects report discomfort or pain 1 year after surgery. Moreover, chronic or subacute inflammation is reported in some cases even a long time after surgery. Another open and debated issue in prosthetic surgery is implant survivorship, especially when related to good prosthesis bone ingrowth. Pulsed Electro Magnetic Fields(PEMFs) treatment, although initially recommended after total joint replacement to promote bone ingrowth and to reduce inflammation and pain, is not currently part of usual clinical practice. The purpose of this review was to analyze existing literature on PEMFs effects in joint replacement surgery and to report results of clinical studies and current indications. We selected all currently available prospective studies or RCT on the use of PEMFs in total joint replacement with the purpose of investigating effects of PEMFs on recovery, pain relief and patients' satisfaction following hip, knee or shoulder arthroplasty. All the studies analyzed reported no adverse effects, and good patient compliance to the treatment. The available literature shows that early control of joint inflammation process in the first days after surgery through the use of PEMFs should be considered an effective completion of the surgical procedure to improve the patient's functional recovery.  相似文献   
9.
As a consequence of the time-varying magnetic field induced by eddy currents, frequency drifting occurs when the sampling window of localized spectroscopy continuously shifts. The frequency drifting and the concomitant phase variations can severely affect spectroscopy results when data are acquired with multiple echo times (TEs), such as in the measurement of glutamate (Glu) concentration using the TE-averaged method. Specifically, the averaged spectra are further broadened and distorted in the presence of residual eddy currents, and editing of the coupled spins of Glu C4 protons is affected, resulting in errors in the measured relative intensity ratio. Postacquisition correction using unsuppressed water as reference can effectively minimize this detrimental effect, as manifested by the significantly enhanced signal intensity. Also, it is demonstrated that the methyl signals of creatine (Cr) at 3.0 ppm and choline (Cho) at 3.2 ppm can be used as internal references in finding frequency and phase disparities between different TEs.  相似文献   
10.
BACKGROUND: The recurrent chronic orofacial swelling caused by orofacial granulomatosis (OFG) can cause significant cosmetic and functional problems but can be prevented if the disease is diagnosed early and promptly treated. Although the enlargement of the lips is described to be the most common presenting complaint, the clinical onset of OFG may be characterized by minor associated mucosal and neurological manifestations, making early diagnosis very difficult or, sometimes, merely presumable. PATIENTS AND METHODS: We retrospectively analyzed the clinical manifestations of 19 patients with OFG, who were examined at our institution between 1998 and 2002, in order to determine their initial manifestations and presenting symptoms. RESULTS: A total of 10 patients showed classical recurrent enlargement of the lips (six lower; four upper) as presenting symptom. In the other nine patients, OFG onset was characterized by transient unilateral facial nerve palsy (two cases), intraoral manifestations (two cases), recurrent swelling of the periorbital area (two cases), of the chin (one case), of the zygomatic area (one case), and of the cheeks (one case). CONCLUSION: Our data underlined that OFG onset could be frequently characterized by widely variable, multiform, and temporary clinical findings. Involvement of atypical sites of the orofacial region and presence of single minor manifestations may occur as presenting symptoms, often preceding the development of traditional clinical findings.  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