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   1270篇
  免费   91篇
  国内免费   7篇
耳鼻咽喉   1篇
儿科学   54篇
妇产科学   39篇
基础医学   139篇
口腔科学   33篇
临床医学   124篇
内科学   195篇
皮肤病学   36篇
神经病学   100篇
特种医学   154篇
外国民族医学   1篇
外科学   208篇
综合类   83篇
预防医学   59篇
眼科学   16篇
药学   65篇
  1篇
肿瘤学   60篇
  2021年   18篇
  2020年   6篇
  2019年   11篇
  2018年   18篇
  2017年   17篇
  2016年   20篇
  2015年   20篇
  2014年   32篇
  2013年   40篇
  2012年   48篇
  2011年   37篇
  2010年   43篇
  2009年   56篇
  2008年   33篇
  2007年   43篇
  2006年   72篇
  2005年   28篇
  2004年   33篇
  2003年   50篇
  2002年   35篇
  2001年   37篇
  2000年   19篇
  1999年   26篇
  1998年   36篇
  1997年   55篇
  1996年   48篇
  1995年   35篇
  1994年   41篇
  1993年   41篇
  1992年   32篇
  1991年   24篇
  1990年   24篇
  1989年   26篇
  1988年   39篇
  1987年   27篇
  1986年   16篇
  1985年   25篇
  1984年   12篇
  1983年   15篇
  1982年   20篇
  1981年   17篇
  1980年   11篇
  1979年   8篇
  1978年   5篇
  1977年   8篇
  1976年   16篇
  1975年   14篇
  1973年   6篇
  1972年   5篇
  1971年   5篇
排序方式: 共有1368条查询结果,搜索用时 15 毫秒
1.
2.
3.
We report the results of administration of danazol after suspension of gonadotrophin-releasing hormone analogue (GnRHa) therapy for uterine myomas. A total of 21 women with uterine myomas was treated with 100 mg danazol for 6 months after GnRHa therapy. Uterine volume and endocrine status were monitored monthly by ultrasound and assay of plasma gonadotrophins, oestradiol and progesterone. The results show a rebound of uterine volume about 30% less than in controls at the end of danazol therapy. Menstrual cyclicity returned after 65 +/- 3 days in 16 subjects and five patients remained amenorrhoeic. Hormone assays confirmed renewed ovarian function in the women whose menstrual periods returned. Bone mineral content was substantially reduced during GnRHa treatment but improved significantly during danazol therapy even in the women who remained amenorrhoeic. These results show the utility of danazol in prolonging the therapeutic effects of GnRHa. The mechanism by which danazol inhibits rebound of uterine volume may be due to its antiprogesterone effects on uterine myomas.   相似文献   
4.
Impact of smoking on cancer stage at diagnosis.   总被引:2,自引:0,他引:2  
BACKGROUND: Studies evaluating the relationship between smoking and cancer spread are limited. METHODS: We studied the relationship between cancer stage at diagnosis (local, regional, or metastatic) and smoking history (current, previous, or nonsmoker). For lung cancer, patterns of spread were also studied. RESULTS: In a tumor registry for eastern North Dakota, northwestern Minnesota, and northern South Dakota, 11,716 cases were identified from 1986 to 2001. Current smokers (relative risk [RR], 2.11; 95% confidence interval, 1.93 to 2.32; P <.001) and previous smokers (RR, 1.56; 95% confidence interval, 1.42 to 1.72; P <.001) had an increased risk of metastatic disease at diagnosis. Current smokers (RR, 1.39; 95% confidence interval, 1.29 to 1.51; P <.001), but not previous smokers, also had an increased risk of regional disease. An increase in metastatic disease was most evident for prostate cancer (RR, 1.53; P =.003). An increase in regional disease was most evident for head and neck (RR, 3.53; P <.001), prostate (RR, 1.83; P =.030), and breast cancer (RR, 1.22; P =.005). Compared with previous smokers, current smokers with metastatic lung cancer were more likely to have involvement of the brain (33.6% v 23.0%; P =.004), bone marrow, adrenal gland, and pericardium (24.7% v 15.9%; P =.004). CONCLUSION: Previous or current smoking is a risk factor for increased cancer stage in a wide range of malignancies. Further study is required to determine whether this association is causal.  相似文献   
5.
6.
7.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm).  相似文献   
8.
The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia.  相似文献   
9.
Previous studies have suggested that the lipopolysaccharide (LPS, endotoxin) component of the gram-negative bacterial cell wall is a key virulence factor that serves to enhance mortality during infections in which fungi and gram-negative bacteria are copathogens. To test this hypothesis, mice were challenged ip with Escherichia coli 0111:B4, Candida albicans, or both, and the effect of administration of anti-E. coli 0111:B4 LPS monoclonal antibody (mAb) 8G9 on endotoxemia, bacteremia, and mortality was assessed. E. coli (2 x 10(7) colony-forming units (CFU)) plus C. albicans (6 x 10(7) CFU) infection produced 100% mortality at 7 days, compared to the relatively low mortality caused by infection with either E. coli or C. albicans alone (20 and 3%, respectively, P less than 0.01). Administration of mAb 8G9 to animals receiving both pathogens reduced mortality (100% versus 14%, P less than 0.05), endotoxemia (3653 +/- 3187 versus 2 +/- 2 endotoxin units (EU), P less than 0.01), and bacteremia (4.2 +/- 2.3 versus 1.1 +/- 2.1 log(CFU/ml), P less than 0.01) compared to animals receiving saline alone. In a separate series of experiments, purified E. coli 0111:B4 LPS was administered in place of viable E. coli. The simultaneous injection of 200 micrograms E. coli LPS and C. albicans (6 x 10(7) CFU) produced 93% mortality at 7 days, compared to the low mortality that occurred following injection with either E. coli 0111:B4 LPS or C. albicans alone (21 and 3% respectively, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
10.
Tissue ischemia, necrosis, and gangrene are uncommon but well-described complications of arterial catheterization in the neonate. Treatment options for progressive tissue necrosis following arterial embolization and/or vasospasm are limited in these patients secondary to unpredictable pharmacokinetics and risks associated with systemic anticoagulation or vasodilatation in newborns. We report a case of a multidose regimen of topical 2% nitroglycerin ointment for reversing severe tissue ischemia following peripheral arterial line placement. The favorable response in this infant suggests that topical nitroglycerin therapy should be considered as potential therapy to ameliorate the effects of vascular compromise following arterial line placement in neonates.  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