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   437篇
  免费   28篇
  国内免费   5篇
儿科学   18篇
妇产科学   9篇
基础医学   101篇
口腔科学   10篇
临床医学   46篇
内科学   115篇
皮肤病学   7篇
神经病学   48篇
特种医学   3篇
外科学   32篇
综合类   5篇
预防医学   30篇
眼科学   7篇
药学   18篇
中国医学   2篇
肿瘤学   19篇
  2023年   5篇
  2022年   4篇
  2021年   11篇
  2020年   10篇
  2019年   9篇
  2018年   14篇
  2017年   8篇
  2016年   16篇
  2015年   15篇
  2014年   15篇
  2013年   16篇
  2012年   36篇
  2011年   43篇
  2010年   10篇
  2009年   20篇
  2008年   22篇
  2007年   31篇
  2006年   28篇
  2005年   10篇
  2004年   13篇
  2003年   21篇
  2002年   14篇
  2001年   13篇
  2000年   7篇
  1999年   11篇
  1998年   4篇
  1997年   2篇
  1996年   2篇
  1995年   3篇
  1994年   1篇
  1993年   5篇
  1992年   8篇
  1991年   5篇
  1989年   5篇
  1988年   9篇
  1987年   6篇
  1986年   3篇
  1985年   6篇
  1984年   2篇
  1983年   1篇
  1982年   1篇
  1978年   1篇
  1977年   2篇
  1969年   1篇
  1966年   1篇
排序方式: 共有470条查询结果,搜索用时 31 毫秒
11.
12.
Nelson’s syndrome (NS) is characterized by the appearance and/or progression of ACTH-secreting pituitary macroadenomas in patients who had previously undergone bilateral adrenalectomy for the treatment of Cushing’s disease. Such corticotroph macroadenomas respond poorly to currently available therapeutic options which include surgery, radiotherapy and chemotherapy. P53 protein accumulation may be detected by immunohistochemistry in pituitary corticotroph adenomas and it has been suggested that it might be causally related to tumor development. Wild type P53 protein plays an important role in the cellular response to ionizing radiation and other DNA damaging agents and is mutated in many human tumors. In this study we report an adult male patient with NS who underwent both transsphenoidal and transcranial pituitary surgeries, conventional and stereotaxic radiotherapy and brachytherapy. Despite of the efforts to control tumor mass and growth, this macroadenoma displayed relentless growth and aggressive behavior. DNA extracted from the first two surgical samples, as well as DNA from peripheral blood leukocytes disclosed normal p53 sequence. DNA extracted from tumor samples obtained at surgeries performed after pituitary irradiation carried a somatic heterozygous mutation, consisting of a deletion of four cytosines between nucleotides 12,144–12,149 in exon 4 of the p53 gene. This frameshift mutation creates a stop codon in exon 4 excluding the expression of a functional protein from the defective allele. These data demonstrate a possible association between the P53 protein loss of function induced by radiotherapy and the aggressive course of the disease in this patient.  相似文献   
13.
14.
15.
16.
The purpose of the present study was to establish the role of DDAH gene polymorphisms in the risk of developing myocardial infarction (MI) in a clinical cohort of Mexican patients. One polymorphism (rs1498373) in the DDAH1 and three in the DDAH2 (rs805304, rs3131383, and rs805305) genes were performed by TaqMan genotyping assays in 473 patients with MI and 447 healthy unrelated controls. Similar distribution of DDAH1 and DDAH2 polymorphisms was observed in MI patients and healthy controls. Under a recessive model adjusted for age, gender, and obesity, the rs805304 C allele was associated with decreased risk of MI (OR = 0.70, 95% CI = 0.51–0.96, P = 0.030). The effect of the polymorphisms on various cardiovascular risk factors was analyzed. Under a recessive model adjusted for age and gender, the DDAH2 rs805304 C allele was associated with decreased risk of obesity (OR = 0.35, 95% CI = 0.22–0.57, P = 0.001). The three DDAH2 polymorphisms were in strong linkage disequilibrium. Our results suggest that the rs805304 C allele was associated with decreased risk of MI and decreased risk of obesity.  相似文献   
17.
18.
Infrapopliteal mycotic aneurysm resulting from endocarditis is rare, with only a few reported cases. We describe the case of a 28-year-old male patient who was suffering with pain and edema in the right leg. The ultrasound revealed an aneurysm of the right tibioperoneal trunk and a deep vein thrombosis (DVT). The patient was admitted and developed acute congestive heart failure, being diagnosed with possible endocarditis. A pseudo-aneurysm was revealed by arteriography. Aggressive antibiotic treatment was initiated, and open surgery confirmed a mycotic pseudo-aneurysm of the tibioperoneal trunk. To our knowledge, this is the 8th case reported of an infected aneurysm in this particular location.  相似文献   
19.
BackgroundAmong older persons, the association between frailty and spirometry-confirmed respiratory impairment has not been evaluated yet.MethodsBy using data on white participants aged 65 to 80 years (Cardiovascular Health Study, N = 3578), we evaluated cross-sectional and longitudinal associations between frailty and respiratory impairment, including their combined effect on mortality. Baseline assessments included frailty status (Fried phenotype: non-frail, pre-frail, and frail) and spirometry. Outcomes included development of frailty features (pre-frail or frail) at year 3 and respiratory impairment (airflow limitation or restrictive pattern) at year 4, and death (median follow-up, 13.2 years).ResultsAt baseline, 48.3% of participants were pre-frail, 5.8% of participants were frail, 13.8% of participants had airflow limitation, and 9.3% of participants had restrictive pattern; 46.1% of participants subsequently died. At baseline, pre-frail and frail were cross-sectionally associated with airflow limitation (adjusted odds ratio [OR], 1.62; 95% confidence interval [CI], 1.29-2.04 and adjusted OR 1.88; 95% CI, 1.15-3.09) and restrictive pattern (adjusted OR, 1.80; 95% CI, 1.37-2.36 and adjusted OR, 3.05; 95% CI, 1.91-4.88), respectively. Longitudinally, participants with baseline frailty features had an increased likelihood of developing respiratory impairment (adjusted OR, 1.42; 95% CI, 1.11-1.82). Conversely, participants with baseline respiratory impairment had an increased likelihood of developing frailty features (adjusted OR, 1.58; 95% CI, 1.17-2.13). Mortality was highest among participants who were frail and had respiratory impairment (adjusted hazard ratio, 3.91; 95% CI, 2.93-5.22), compared with those who were non-frail and had no respiratory impairment.ConclusionFrailty and respiratory impairment are strongly associated with one another and substantially increase the risk of death when both are present. Establishing these associations may inform interventions designed to reverse or prevent the progression of either condition and to reduce adverse outcomes.  相似文献   
20.

OBJECTIVE:

To evaluate the effects of the levels of glycemic control on the frequency of clinical complications following invasive dental treatments in type 2 diabetic patients and suggest appropriate levels of fasting blood glucose and glycated hemoglobin considered to be safe to avoid these complications.

METHOD:

Type 2 diabetic patients and non-diabetic patients were selected and divided into three groups. Group I consisted of 13 type 2 diabetic patients with adequate glycemic control (fasting blood glucose levels <140 mg/dl and glycated hemoglobin (HbA1c) levels <7%). Group II consisted of 15 type 2 diabetic patients with inadequate glycemic control (fasting blood glucose levels >140 mg/dl and HbA1c levels >7%). Group III consisted of 18 non-diabetic patients (no symptoms and fasting blood glucose levels <100 mg/dl). The levels of fasting blood glucose, glycated HbA1c, and fingerstick capillary glycemia were evaluated in diabetic patients prior to performing dental procedures. Seven days after the dental procedure, the frequency of clinical complications (surgery site infections and systemic infections) was examined and compared between the three study groups. In addition, correlations between the occurrence of these outcomes and the glycemic control of diabetes mellitus were evaluated.

RESULTS:

The frequency of clinical outcomes was low (4/43; 8.6%), and no significant differences between the outcome frequencies of the various study groups were observed (p>0.05). However, a significant association was observed between clinical complications and dental extractions (p = 0.02).

CONCLUSIONS:

Because of the low frequency of clinical outcomes, it was not possible to determine whether fasting blood glucose or glycated HbA1c levels are important for these clinical outcomes.  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