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   2126篇
  免费   120篇
  国内免费   11篇
耳鼻咽喉   11篇
儿科学   109篇
妇产科学   36篇
基础医学   398篇
口腔科学   29篇
临床医学   244篇
内科学   397篇
皮肤病学   60篇
神经病学   163篇
特种医学   108篇
外科学   244篇
综合类   22篇
一般理论   3篇
预防医学   174篇
眼科学   21篇
药学   137篇
中国医学   4篇
肿瘤学   97篇
  2022年   11篇
  2021年   15篇
  2020年   22篇
  2019年   26篇
  2018年   36篇
  2017年   21篇
  2016年   44篇
  2015年   35篇
  2014年   40篇
  2013年   63篇
  2012年   93篇
  2011年   130篇
  2010年   69篇
  2009年   65篇
  2008年   106篇
  2007年   110篇
  2006年   100篇
  2005年   103篇
  2004年   90篇
  2003年   78篇
  2002年   109篇
  2001年   69篇
  2000年   91篇
  1999年   63篇
  1998年   29篇
  1997年   30篇
  1996年   19篇
  1995年   23篇
  1994年   23篇
  1993年   22篇
  1992年   46篇
  1991年   39篇
  1990年   36篇
  1989年   24篇
  1988年   24篇
  1987年   17篇
  1986年   20篇
  1985年   25篇
  1984年   14篇
  1983年   21篇
  1982年   9篇
  1980年   9篇
  1979年   23篇
  1978年   14篇
  1977年   11篇
  1976年   9篇
  1971年   8篇
  1969年   10篇
  1968年   8篇
  1942年   10篇
排序方式: 共有2257条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Zusammenfassung Bei einer 71j?hrigen Frau trat nach R?ntgenweichstrahltherapie an der Nase (Gesamtdosis 28 Gy, Gewebehalbwerttiefe 10,5–11,5 mm) eine ausgepr?gte Strahlenerosion auf. Diese zeigte 5 Wochen nach Ende der Bestrahlung noch keine Tendenz zur Abheilung. Ursache dieses ungew?hnlichen Verlaufes war ein gleichzeitig bestehender Pemphigus vulgaris. Dieser hatte sich nach der Strahlentherapie, vermutlich als Folge einer Freisetzung epidermaler Antigene, verschlimmert. Da? der Pemphigus in diesem Fall durch die Bestrahlung ausgel?st wurde – wie mehrfach in der Literatur berichtet – ist unwahrscheinlich, aber nicht sicher auszuschlie?en. Eingegangen am 11. April 1994 Angenommen am 10. Juni 1994  相似文献   
5.
Multiple structural and functional imaging modalities are available to localize the epileptogenic focus. In pre-surgical evaluation of children with pharmacoresistant epilepsy, investigations with the maximum yield should be considered in order to reduce the complexity of the workup. OBJECTIVE: To determine the extent to which PET, ictal/interictal SPECT and its co-registration with the patient's MRI contributes to correct localization of the epileptogenic focus, surgical intervention and to the post surgical outcome in paediatric patients. METHODS: The study population included children and adolescents with pharmacoresistant epilepsy (n = 50) who underwent preoperative evaluation, surgery and had postoperative follow-up for at least 12 months. Outcome was measured by postoperative seizure frequency using Engel's classification. RESULTS: Thirty-nine patients (78%) became completely seizure free after surgical intervention. The likelihood to benefit from surgical treatment was significantly higher if localization with more imaging modalities (MRI, PET, SPECT) were concordant with respect to the resected brain area (p < 0.01). Preoperative PET examination provided better localizing information in patients with extratemporal epilepsy and/or dysplastic lesions, whereas SPECT was found to be superior to PET in patients with temporal lobe epilepsy and/or tumors (p < 0.05). No significant difference was noted in the surgical outcome in younger or older age group, in children with or without special education needs. CONCLUSION: In paediatric epilepsy pre-surgical evaluation, the combined use of multiple functional imaging modalities for a precise localisation of the epileptogenic focus is worthwhile for both extratemporal and temporal lobe epilepsy, also when EEG and MRI alone are non-contributive, given the potential benefit of complete postoperative seizure control.  相似文献   
6.
7.
We have measured the metabolic response to sequential administration of propacetamol, metamizol and/or external cooling in 20 febrile patients under sedation and analgesia and during mechanical ventilation. There was no change in temperature (T degree) after propacetamol therapy, whereas after metamizol only a small decrease was noted (from 38.9 (SEM 0.2) to 38.5 (0.3) degrees C; P = 0.02). External cooling produced a significant decrease in T degree (39.1 (0.2) to 37.1 (0.2) degrees C; P < 0.0001) accompanied by a decrease in energy expenditure (EE) (2034 (73) to 1791 (88) kcal day-1; P < 0.004). Heart rate and minute ventilation decreased significantly in parallel. There were no other changes in haemodynamics or pulmonary gas exchanges. We conclude that propacetamol and metamizol did not produce a clinically significant decrease in T degree in febrile ICU patients whereas external cooling decreased both T degree and EE. The parallel decrease in body temperature and EE seemed to be related to opioid administration or sedation, or both.   相似文献   
8.
Our experiences with cobalt bleomycin scintigraphy in the treatment planning of ORL tumors are described. 142 scintigrams taken from 127 patients have been examined. As is shown by our investigation, cobalt bleomycin scintigraphy is a good examination method, however, too much expenditure is needed to have the necessary data for therapy planning. To our opinion, the information obtained in oto-rhino-laryngology by an exact clinical examination is as good as that of cobalt bleomycin scintigraphy. Our treatment schemes had only to be revised in some exceptional cases.  相似文献   
9.
The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging.  相似文献   
10.
Background Cosmetic changes are to be expected after radiotherapy for skin tumours. Objectives This study aimed to answer the questions: How frequent are cosmetic changes after soft X‐ray therapy? Do treatment parameters, tumour thickness, localization and size of the irradiated field have a major influence? Were patients irritated by the visual appearance of the irradiated field? Methods In total, 2474 examinations of 1149 irradiated fields were performed. Results Hypopigmentation was found in 64.7% of examinations more than 90 days after therapy, teleangiectases in 43.1%, erythema in 24.8%, and hyperpigmentation in 16.8%. The frequency of hypopigmentation, teleangiectases and hyperpigmentation increased with time from X‐ray exposure; more than 4 years after therapy hypopigmentation was diagnosed in 91.8% and teleangiectases in 82.2% of examinations. Total dose, the time–dose–fractionation factor (TDF), field size and dose per fraction were significantly related to the frequency of cosmetic changes. Incidence rates of cosmetic changes differed by less than 15% if different treatment conditions were compared: thicker vs. thinner tumours, larger vs. smaller fields, higher vs. lower total doses, doses per fraction, and TDF. Frequencies of hypopigmentation, teleangiectases, erythema and hyperpigmentation differed by more than 15% between some localizations on the head. Women reported irritation by the visual appearance of the irradiated field in 12.6% of 1116 interviews, and men in 4.4% of 1284 interviews. Conclusions Cosmetic changes after soft X‐ray therapy are relatively frequent. Treatment parameters, tumour thickness and field size have only a minor influence. Few patients, but more women than men, were irritated by the visual appearance of the irradiated field.  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