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   3387篇
  免费   183篇
  国内免费   5篇
耳鼻咽喉   59篇
儿科学   239篇
妇产科学   49篇
基础医学   412篇
口腔科学   53篇
临床医学   219篇
内科学   697篇
皮肤病学   110篇
神经病学   188篇
特种医学   84篇
外科学   508篇
综合类   101篇
预防医学   153篇
眼科学   136篇
药学   317篇
中国医学   17篇
肿瘤学   233篇
  2023年   25篇
  2022年   39篇
  2021年   115篇
  2020年   55篇
  2019年   66篇
  2018年   98篇
  2017年   62篇
  2016年   72篇
  2015年   71篇
  2014年   117篇
  2013年   129篇
  2012年   236篇
  2011年   226篇
  2010年   116篇
  2009年   87篇
  2008年   147篇
  2007年   152篇
  2006年   150篇
  2005年   130篇
  2004年   121篇
  2003年   100篇
  2002年   95篇
  2001年   76篇
  2000年   55篇
  1999年   71篇
  1998年   21篇
  1997年   21篇
  1995年   25篇
  1993年   21篇
  1992年   79篇
  1991年   57篇
  1990年   47篇
  1989年   54篇
  1988年   44篇
  1987年   38篇
  1986年   52篇
  1985年   38篇
  1984年   34篇
  1983年   21篇
  1982年   20篇
  1979年   33篇
  1977年   20篇
  1976年   33篇
  1975年   21篇
  1973年   19篇
  1972年   21篇
  1971年   23篇
  1970年   28篇
  1969年   27篇
  1967年   19篇
排序方式: 共有3575条查询结果,搜索用时 15 毫秒
1.
2.
Anxiety disorders and anxiety symptoms are highly prevalent in the general population and more so in the medically ill. They have a number of negative consequences for these patients and may worsen the outcome of the medical illness and increase health care utilization. In the evaluation of these patients, it is of paramount importance to identify the etiology of the anxiety and, in particular, to differentiate primary from secondary anxiety. Management includes medications (especially benzodiazepines and selective serotonin reuptake inhibitors) and psychotherapy (particularly cognitive-behavioral therapy).  相似文献   
3.
4.
BACKGROUND: The periodontal ligament (PDL) is a soft tissue interposed between the tooth and the alveolar bone. It is responsible for transmission of forces in vivo; this promotes bone remodeling. The purpose our study was to use fractal analysis to quantify the complex morphology of the PDL-bone interface. METHODS: We used Scion Image (Scion Corp, Frederick, Md) and Benoit fractal analysis (Tru Soft International, St. Petersburg, Fla) programs to calculate the fractal dimension of the PDL-bone interface in rats via the box-counting method. Rats in the experimental groups received an initial force of 0.1N or 0.5N with customized springs for 6 hours. RESULTS: Our studies showed an increase in normal fractal dimension at the root apices of the rats' maxillary molars. We also found evidence that the fractal dimension varies along the entire root length from the apex to the cementoenamel junction. CONCLUSIONS: Mechanical loading might lead to an increase in fractal dimension at the PDL-bone interface apart from mechanisms of bone cell directed remodeling. These changes in fractal dimension are proportional to loading and could provide a new parameter for force determination in orthodontic tooth movement.  相似文献   
5.
O P Khanna  J H Loose 《Urology》1990,36(2):139-142
Three patients with interstitial cystitis diagnosed on the basis of clinical symptoms, classic endoscopic findings, and a typical histologic picture were treated with intravesical doxorubicin. All 3 patients showed remarkable improvement, as manifested by complete clearance of irritative bladder symptoms and healing of ulceration. Doxorubicin therefore may be the breakthrough drug for interstitial cystitis.  相似文献   
6.
7.
Physiological analysis to quantify training load in badminton.   总被引:2,自引:1,他引:1       下载免费PDF全文
OBJECTIVE: To estimate the training load of specific on court training regimens based on the magnitude of variation of heart rate-lactate response during specific training and to determine the magnitude of variation of biochemical parameters (urea, uric acid, and creatine phosphokinase (CPK)) 12 hours after the specific training programme so as to assess training stress. METHODS: The study was conducted on six national male badminton players. Maximum oxygen consumption (VO2), ventilation (VE), heart rate, and respiratory quotient were measured by a protocol of graded treadmill exercise. Twelve training sessions and 35 singles matches were analysed. Heart rate and blood lactate were monitored during technical training routines and match play. Fasting blood samples collected on two occasions--that is, during off season and 12 hours after specific training--were analysed for serum urea, uric acid, and CPK. RESULTS: Analysis of the on court training regimens showed lactate values of 8-10.5 mmol/l in different phases. The percentage of maximum heart rate ranged from 82% to 100%. Urea, uric acid, and CPK activity showed significant changes from (mean (SD)) 4.93 (0.75) mmol/l to 5.49 (0.84) mmol/l, 0.23 (0.04) to 0.33 (0.06) mmol/l, and 312 (211.8) to 363 (216.4) IU/l respectively. CONCLUSION: Maximum lactate reported in the literature ranges from 3-6 mmol/l. Comparatively high lactate values and high percentage of maximum heart rate found in on court training show a considerable stress on muscular and cardiovascular system. The training load needs appropriate monitoring to avoid over-training. Workouts that are too intensive may interfere with coordination, a factor that is important in sports requiring highly technical skill such as badminton.  相似文献   
8.
9.
Intraabdominal pressures were measured during natural activities in 6 men, age 24-62 years, treated with continuous ambulatory peritoneal dialysis. The pressures were measured with a pressure transducer secured at the level of the umbilicus in the supine, sitting, and upright positions with 0-3 liters intraperitoneal fluid during talking, coughing, straining, changing position, walking, jogging, exercycling, jumping and weight lifting. Coughing and straining generated the highest intraabdominal pressures in every position. The pressures with weight lifting were proportional to the magnitude of the weight lifted up to 50 lbs, but were lower than those during coughing and straining. The pressures were generally higher with greater intraabdominal fluid volumes, especially with jumping and coughing. Exercycling was associated with lower intraabdominal pressure than was jogging, and the pressures were only minimally influenced by intraperitoneal fluid volumes. The results of this study can be used as a guide in establishing preventive measures in patients with intraperitoneal fluid to decrease complication rates related to raised intraabdominal pressures such as dialysate leaks, hernias and hemorrhoids.  相似文献   
10.
Fine needle aspiration cytology, imprint cytology and tru-cut needle biopsy were performed in 86 patients with breast lump and the results of these techniques were finally compared with the incisional or excisional biopsy in all the patients. Fine needle aspiration cytology had the sensitivity of 96.8% and specificity of 100%, the imprint cytology had the sensitivity of 98.4% and specificity of 100%. While the tru-cut needle biopsy had the sensitivity and specificity of 100% though in this technique 15 of 86 (17.4%) specimens were rejected as insufficient for any diagnosis.  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