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   8993篇
  免费   637篇
  国内免费   57篇
耳鼻咽喉   46篇
儿科学   237篇
妇产科学   291篇
基础医学   1437篇
口腔科学   187篇
临床医学   940篇
内科学   1797篇
皮肤病学   374篇
神经病学   890篇
特种医学   300篇
外国民族医学   7篇
外科学   796篇
综合类   50篇
一般理论   2篇
预防医学   735篇
眼科学   93篇
药学   683篇
中国医学   20篇
肿瘤学   802篇
  2024年   9篇
  2023年   61篇
  2022年   91篇
  2021年   232篇
  2020年   168篇
  2019年   219篇
  2018年   225篇
  2017年   189篇
  2016年   250篇
  2015年   263篇
  2014年   370篇
  2013年   444篇
  2012年   709篇
  2011年   839篇
  2010年   437篇
  2009年   395篇
  2008年   639篇
  2007年   689篇
  2006年   634篇
  2005年   620篇
  2004年   530篇
  2003年   430篇
  2002年   417篇
  2001年   73篇
  2000年   61篇
  1999年   77篇
  1998年   80篇
  1997年   85篇
  1996年   71篇
  1995年   44篇
  1994年   44篇
  1993年   35篇
  1992年   40篇
  1991年   16篇
  1990年   13篇
  1989年   14篇
  1988年   11篇
  1987年   11篇
  1986年   21篇
  1985年   10篇
  1984年   7篇
  1983年   10篇
  1981年   10篇
  1979年   8篇
  1977年   10篇
  1975年   13篇
  1973年   7篇
  1972年   7篇
  1970年   6篇
  1968年   6篇
排序方式: 共有9687条查询结果,搜索用时 46 毫秒
1.
European Surgery - Large skin defects caused by trauma (e.g., burns) or due to other reasons (e.g., tumor-related skin resections) require sufficient skin replacement. The constant improvement of...  相似文献   
2.
3.
4.
5.
6.
7.
We describe a case of a palatal tic resembling palatal tremor (PT) in a young female patient with a previously unrecognized mild Tourette syndrome. At the time of her visit, the patient complained about ear clicks that were audible to others. We discuss the differential diagnoses of hyperkinetic palatal movements emphasizing the ongoing discussion about essential PT representing a more heterogeneous disorder than previously thought.  相似文献   
8.
A Barzilai  A Horowitz  A Geier  H Degani 《Cancer》1991,67(11):2919-2925
Phosphorous 31 (31P) nuclear magnetic resonance (NMR) spectra were recorded from perchloric acid extracts of benign and malignant breast tumors. The spectra were correlated with the histopathologic diagnosis and the steroid receptor status of the tumor. Higher relative content of the lipid-derived metabolite glycerolphosphoethanolamine (GPE), the high-energy nucleoside phosphates (nucleoside-diphosphate [NDP], nucleoside-triphosphate [NTP]), and sugar esters of uridine diphosphate (UDPS) appeared in the carcinomas. Malignant tumors also showed a lower ratio of phosphoethanolamine to phosphocholine (PE/PC) than benign conditions. Lower content of the lipid-derived metabolite glycerolphosphocholine (GPC) and high content of the high-energy compound phosphocreatine (PCr) were associated with malignant tumors having high content of estrogen receptors (ER). High PCr content was also associated in the carcinomas with high progesterone receptors (PgR) content. In the benign tumors NDP and NTP were higher in tumors with high PgR content. The authors suggest that 31P magnetic resonance spectroscopy (MRS) of the breast can provide additional variables to diagnose malignancy, and when combined with magnetic resonance imaging (MRI), invasive procedures may be avoided. It also seems that levels of PCr and GPC obtained from the spectra can serve as markers to hormonal receptor status of breast carcinomas, and may be used in addition to the ER and PgR content to improve prediction of the response to hormonal therapy. Additional development requires in situ MRI and MRS combined studies.  相似文献   
9.
PURPOSE: To compare commercial treatment-planning systems (TPS) for inverse planning (IP) and to assess constraint variations for specific IMRT indications. MATERIAL AND METHODS: For IP, OTP, XiO and BrainSCAN were used and step-and-shoot intensity-modulated radiotherapy (IMRT) delivery was assumed. Based on identical constraints, IP was performed for a prostate, head and neck, brain, and gynecologic case. IMRT plans were compared in terms of conformity/homogeneity, dose-volume histograms (DVHs), and delivery efficiency. For ten patients each of a class of indications, constraint variations were evaluated. RESULTS: IMRT plans were comparable concerning minimum target dose, homogeneity, conformity, and maximum doses to organs at risk. Larger differences were seen in dose gradients outside the target, monitor units, and segment number. Using help structures proved efficient to shape isodoses and to reduce segmentation workload. For IMRT class solutions, IP constraint variations depended on anatomic site. CONCLUSION: IP systems requiring doses as input and having objective functions based on physical parameters had a very similar performance. Constraint templates can be established for a class of IMRT indications.  相似文献   
10.
Background: Auricular acupuncture at the relaxation point has been previously shown to be an effective treatment for anxiety in the preoperative setting. The purpose of this prospective, randomized, blinded study was to determine whether auricular acupressure can reduce stress and anxiety during ambulance transport.

Methods: Patients who required ambulance transport secondary to medical conditions were randomized to receive auricular acupressure at the relaxation point (n = 17) or at a sham point (n = 19). A visual analog scale was used to assess state anxiety as well as patient anticipation of hospital medical treatment (estimated waiting period for treatment, anticipated pain during treatment, attitude toward the physicians, and treatment outcomes). These variables were assessed at baseline and on arrival to the hospital.

Results: Patients in the relaxation group reported significantly less anxiety than patients in the sham group on arrival to the hospital (visual analog scale mean +/- SD: 37.6 +/- 20.6 to 12.4 +/- 7.8 mm vs. 42.5 +/- 29.9 to 46.7 +/- 25.9 mm, respectively;P = 0.002). Similarly, patient perception of pain during treatment (mean visual analog scale +/- SD: 32.7 +/- 27.7 to 14.5 +/- 8.1 mm vs. 17.2 +/- 26.1 to 28.8 +/- 21.9 mm, respectively;P = 0.006) and treatment outcomes of their illnesses (mean visual analog scale +/- SD: 46.7 +/- 29.4 to 19.1 +/- 10.4 mm vs. 35.0 +/- 25.7 to 31.5 +/- 20.5 mm, respectively;P = 0.014) were significantly more positive in the relaxation group than in the sham group. No differences were found in the other variables assessed.  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