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   17445篇
  免费   1407篇
  国内免费   19篇
耳鼻咽喉   421篇
儿科学   610篇
妇产科学   544篇
基础医学   1931篇
口腔科学   241篇
临床医学   1590篇
内科学   3236篇
皮肤病学   419篇
神经病学   1388篇
特种医学   847篇
外科学   3451篇
综合类   467篇
一般理论   9篇
预防医学   1390篇
眼科学   405篇
药学   790篇
中国医学   5篇
肿瘤学   1127篇
  2021年   123篇
  2020年   111篇
  2019年   152篇
  2018年   208篇
  2017年   144篇
  2016年   161篇
  2015年   664篇
  2014年   797篇
  2013年   910篇
  2012年   1070篇
  2011年   1002篇
  2010年   843篇
  2009年   848篇
  2008年   1041篇
  2007年   1082篇
  2006年   982篇
  2005年   885篇
  2004年   704篇
  2003年   472篇
  2002年   450篇
  2001年   412篇
  2000年   394篇
  1999年   380篇
  1998年   189篇
  1997年   180篇
  1996年   147篇
  1995年   127篇
  1994年   141篇
  1993年   154篇
  1992年   299篇
  1991年   256篇
  1990年   251篇
  1989年   265篇
  1988年   213篇
  1987年   212篇
  1986年   184篇
  1985年   192篇
  1984年   151篇
  1983年   163篇
  1982年   117篇
  1981年   90篇
  1980年   89篇
  1979年   136篇
  1978年   100篇
  1977年   99篇
  1976年   104篇
  1974年   105篇
  1973年   98篇
  1972年   93篇
  1971年   88篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
The ovariectomized rat is the most commonly used animal model of human postmenopausal osteoporosis, exhibiting a high rate of bone turnover with resorption exceeding formation. At present, bone turnover is quantified directly by dynamic histomorphometry. The aim of the present study was to determine whether the measurement of the urinary output of some specific bone collagen catabolites — pyridinolines and hydroxylysine glycosides — could be used to indirectly monitor the initial phase of bone turnover increase in ovariectomized 90-day-old rats. Ninety-day-old female rats were randomly divided into three groups (n=6): ovariectomized, sham-operated and non-treated controls. Urine samples (24 h) were collected 6 days before surgery and twice weekly for the 4 weeks following ovariectomy. Urinary excretion of pyridinoline (PYD), deoxypyridinoline (DPD), glucosyl-galactosyl-hydroxylysine (GGHYL) and galactosyl-hydroxylysine (GHYL) were measured. As expected, ovariectomy was associated with a significant decrease in bone mineral density in both the proximal tibial and distal femoral metaphysis. Compared with both sham-operated and control animals, ovariectomized rats showed significant increases in PYD, GGHYL and GHYL urinary output 8 days after surgery and in DPD output after 15 days. These changes were maintained throughout the study. The results confirm that measurement of the urinary excretion of pyridinolines and hydroxylysine glycosides represents a powerful tool for detecting the onset of bone turnover in ovariectomized 90-day-old rats.  相似文献   
63.
After a fracture of the distal radius, especially with malunion, many patients complain of a decreased range of forearm rotation and pain on the ulnar side of the wrist. The purpose of this article is to describe the therapeutic options available in such cases. Decision making as to whether there is an indication for corrective surgery or not is based on the patient’s symptoms and the clinical findings, whereas the decision as to which surgery to perform must take into account the radiological findings. If possible, reconstruction of the anatomy using a distal radius osteotomy should be carried out.  相似文献   
64.
Zusammenfassung Einleitung: Das Ziel dieser Studie war die Entwicklung eines spezifischen Schweregradklassifizierungssystems für die Beurteilung und Vorhersage von Organfunktionsstörungen und Überleben bei herzchirurgischen Intensivpatienten. Methoden: Hierzu wurden konsekutiv alle erwachsenen Patienten nach einem herzchirurgischen Eingriff unter Einsatz der Herzlungenmaschine über einen Zeitraum von 3 Jahren in die Studie aufgenommen. Im Konstruktionsset erfolgte die Auswahl der Variablen mit Hilfe der Patienten, die mindestens 24 Stunden auf der Intensivstation verbrachten. Die Ergebnisse wurden dann in zwei Validierungssets mit allen Intensivpatienten überprüft. Die Qualität des Scores wurde mit dem Hosmer-Lemeshow-Test (HL) sowie der ROC-Analyse beurteilt, und mit dem APACHE-II- und dem MODS-Score verglichen. Ergebnisse: Insgesamt wurden 3230 Patienten über einen Zeitraum von 3 Jahren auf unserer Intensivstation aufgenommen. Die HL-Werte für den neuen Score waren 5,8 (APACHE-II: 11,3; MODS: 9,7) für das Konstruktionsset, 7,2 (APACHE-II: 8,0; MODS: 4,5) für das Validierungsset I und 5,9 für das Validierungsset II. Die Fläche unter der ROC-Kurve war 0,91 (APACHE-II: 0,86; MODS: 0,84) für den neuen Score im Konstruktionsset, 0,88 (APACHE-II: 0,84; MODS: 0,84) in dem Validierungsset I, und 0,92 in dem Validierungsset II. Schlussfolgerung: Der neue CASUS (Cardiac Surgery Score) zeigt für herzchirurgische Intensivpatienten eine exzellente Kalibrierung und Diskriminierung bezüglich der 30-Tage-Letalität. Die Variablen des CASUS sind einfach, reproduzierbar und werden routinemäßig in herzchirurgischen Intensivstationen erfasst. Der CASUS könnte als Expertensystem für das Diagnostizieren von Organfunktionsstörungen, der Entscheidungsfindung, der Ressourcenauswertung und Vorhersage der Letalität für herzchirurgische Intensivpatienten dienen.  相似文献   
65.
66.
Chronic pruritus (starting from 6 weeks duration) is symptom of dermatological, internal, neurological or psychiatric disease. Identification and treatment of the underlying diseases is of great importance especially in the initial phase of chronic pruritus in order to prevent peripheral and central sensitization processes and thus chronification. Application of the redefined clinical classification, newly defined clinical algorithms and inquiry of clinical characteristics of pruritus is helpful in finding the underlying disease. In chronic pruritus existing for several years, clarifying the underlying origin is difficult and therapies are often ineffective. Next to conventional therapies such as antihistamines and corticosteroids, central effective substances can be applied preventing pruritus sensation on spinal or cerebral level.  相似文献   
67.
Schmerztherapie     
Ohne Zusammenfassung  相似文献   
68.
Wegener’s granulomatosis (WG) is a necrotising granulomatous small vessel vasculitis with a clinical predilection for the involvement of the upper airways, lungs and kidneys. It occurs at all ages. The pathogenesis of WG is determined by the pathological activation of phagocytes during transmigration through the vessel. Whereas most aspects of WG are similar at all ages, some features appear to be significantly different. WG in childhood is more frequently complicated by subglottic stenosis and nasal deformity, while treatment related morbidity is less common compared to adults. The introduction of combined treatment with cyclophosphamide and glucocorticoids has resulted in a dramatic improvement in patient outcome; however, commonly occurring disease relapses and the risk of chronic organ damage at all ages make long-term follow-up of all patients necessary.  相似文献   
69.
Objective: To determine the effects of a total laryngectomy on the swallow and subsequent quality of life in head and neck cancer patients. Design: Cross‐sectional single centre cohort study. Setting: Head and Neck Oncology Unit, Tertiary Referral Unit. Patients: Sixty‐two patients who underwent total laryngectomy at our centre participated in the study. Methods: Subjects were stratified by age, sex, tumour stage, other procedures such as myotomy and nerve re‐implantation. Pharyngectomy, glossectomy, flap reconstruction, neck dissection and previous radio‐ and chemotherapy were also assessed to see if they affected swallow and subsequent quality of life. Main outcome was measured using the MD Anderson Dysphagia Inventory questionnaire. Results: Responses were received from 46 males and 16 females (response rate of 80.5%) with a mean age of 64.7 years (SD 9.4). Median follow‐up in patients was 90 months (range 1–276). The mean MD Anderson Dysphagia Inventory total score in our series of patients was 77.7 (SD 16.6). MD Anderson Dysphagia Inventory global score was 79.4 (SD 22.6), Emotional score was 77.7 (SD 17.8), Functional score 81.3 (SD 15.9) and Physical score was 74.1(SD 18). Statistically significant differences were seen between the emotional scores of glossectomised and non‐glossectomised patients (Mann Whitney, P = 0.04). No significant correlation was seen between the subscale scores and the remaining treatment variables such as age, gender, site, tumour stage, myotomy, nerve implantation, radiotherapy, reconstruction and major complications. Conclusion: This questionnaire study is the largest of its type to assess the swallow of patients who have undergone laryngectomy at a single centre. The overall result confirmed that most patients had a subjectively good swallow. Only glossectomy and the method of PE segment closure were shown to significantly affect swallowing outcomes following surgery. We recommend further work especially prospective studies pre and post surgery using this or similarly validated instruments to fully assess swallow in the laryngectomy population.  相似文献   
70.
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