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   776篇
  免费   41篇
  国内免费   4篇
耳鼻咽喉   6篇
儿科学   10篇
妇产科学   11篇
基础医学   88篇
口腔科学   6篇
临床医学   67篇
内科学   188篇
皮肤病学   5篇
神经病学   133篇
特种医学   45篇
外科学   77篇
预防医学   60篇
眼科学   3篇
药学   65篇
  1篇
肿瘤学   56篇
  2023年   11篇
  2022年   26篇
  2021年   34篇
  2020年   16篇
  2019年   25篇
  2018年   36篇
  2017年   15篇
  2016年   28篇
  2015年   26篇
  2014年   33篇
  2013年   37篇
  2012年   42篇
  2011年   59篇
  2010年   26篇
  2009年   32篇
  2008年   50篇
  2007年   48篇
  2006年   34篇
  2005年   31篇
  2004年   56篇
  2003年   50篇
  2002年   25篇
  2001年   11篇
  2000年   8篇
  1999年   10篇
  1998年   4篇
  1997年   4篇
  1996年   7篇
  1995年   5篇
  1994年   2篇
  1993年   4篇
  1991年   3篇
  1990年   6篇
  1989年   8篇
  1988年   5篇
  1982年   2篇
  1980年   1篇
  1978年   1篇
排序方式: 共有821条查询结果,搜索用时 0 毫秒
1.
Coronary angioplasty is unsuccessful in <3–5% of cases because the balloon catheter fails to follow a guidewire that has traversed a lesion. Between June 1986 and August 1987, 31 lesions were unable to be crossed with at least two standard angioplasty catheters. Finally, a 2.0-mm-diameter Hartzler LPS (ACS) was utilized and successfully crossed and dilated 16 out of 31 lesions (52%). In the remaining 15 lesions, the ProbeTM (USCI) 2.0 mm diameter × 1.5 cm long balloon wire was able to cross the lesions in 13 (82%) and successfully dilated 12. In one case, lesion rigidity prevented the balloon from expanding at 14 atm. A right coronary artery lesion was attempted in 11 cases, and a left anterior descending and circumflex artery lesion in two patients each. No complications were encountered. In seven out of 12 successful ProbeTM cases, a larger balloon catheter was used to further dilate the artery. This new balloon wire has increased our success rate in severe stenoses and in tortuous vessels with severe distal lesions, in which presently available angioplasty equipment has failed.  相似文献   
2.
ABSTRACT: BACKGROUND: We recently showed that LOH proximal to M6P/IGF2R locus (D6S1581) in primary ovarian tumors is predictive for the presence of disseminated tumor cells (DTC) in the bone marrow (BM). For therapy-monitoring, it would be highly desirable to establish a blood-based biomarker. Therefore, we quantified circulating DNA (cirDNA) in sera of 63 ovarian cancer patients before surgery and after chemotherapy, measured incidence of LOH at four cancer-relevant chromosomal loci, correlated LOH with tumor cell spread to the BM and evaluated prognostic significance of LOH. Patients and Methods: cirDNA was fractionated into high- and low molecular-weight fraction (HMWF, LMWF) for LOH-profiling, utilizing PCR-based fluorescence microsatellite analysis. BM aspirates were analyzed for DTC by immunocytochemistry using the pan-cytokeratin antibody A45-B/B3. RESULTS: cirDNA levels in the HMWF before surgery were predictive for residual tumor load (p=0.017). After chemotherapy, we observed a significant decline of cirDNA in the LMWF (p=0.0001) but not in the HMWF. LOH was prevalently detected in the LMWF with an overall frequency of 67 %, only moderately ablating after chemotherapy (45 %). Before surgery, LOH in the LMWF at marker D10S1765 and D13S218 significantly correlated with tumor grading and FIGO stage (p=0.033, p=0.004, respectively). In both combined fractions, LOH at D6S1581 additionally associated with overall survival (OS) (p=0.030). Moreover, solely LOH at D10S1765 in LMWF after therapy correlated with DTC in BM after therapy (p=0.017). CONCLUSION: We demonstrate the applicability and necessity of DNA-fractionation prior to analyzing circulating LOH and identify LOH at D10S1765 and D6S1581 as novel blood-based biomarkers for ovarian cancer, being relevant for therapy-monitoring.  相似文献   
3.
Background: Nutritional quality during pregnancy is crucial for mother and child health and their short/long-term outcomes. The aim of this study is to evaluate the adherence to nutritional recommendations in Italy during the three pregnancy trimesters in Normal Weight (NW) and Over Weight (OW) women. Methods: Data from a multicenter randomized controlled trial included 176 women (NW = 133; OW = 43) with healthy singleton pregnancies enrolled within 13 + 6 weeks of gestation. Dietary intake was assessed every trimester by a Food Frequency Questionnaire. Results: OW and NW had similar gestational weight gain. However, as Institute of Medicine (IOM) recommend lower gestational weight gain (GWG) for OW, they exceeded the suggested range. In both groups, caloric intake during the three trimesters never met recommendations. Protein intake in first and second trimester was higher than recommendations, as was sugars percentage. Dietary fiber intake was lower in OW. Polyunsaturated fatty acids, calcium, iron and folic acid requirements were never satisfied, while sodium intake exceeded recommendations. Conclusions: NW and OW women in Italy do not adhere to nutritional recommendations during pregnancy, with lower caloric intake, protein and sugars excess and inadequacies in micronutrients intake. Pregnant women in Italy should be provided with an adequate counseling and educational intervention as well as supplementation when indicated.  相似文献   
4.
Streptococcus bovis is one of the nonenterococcal species included among the streptococci group D. It is part of the normal bowel flora in humans and animals, but it is also responsible for infectious diseases (10-15% of all cases of bacterial endocarditis). Many cases of bacteremia and metastatic abscesses (spleen, liver, soft tissues, bone, meninges, endocardium) caused by S. bovis were reported as associated with digestive tract diseases, mainly colonic disease, and, in particular colonic neoplasms, or chronic liver diseases. A role in carcinogenesis has been suggested for this microorganism. The authors report two cases of S. bovis sepsis, one associated with colonic neoplasm and the other with liver cirrhosis and gastric carcinoma. Discussion is focused on probable mechanisms that favor gastric colonization and systemic diffusion of S. bovis from the gut in patients with gastrointestinal neoplasms or chronic liver disease and provides clinical recommendations for patients with S. bovis infections.  相似文献   
5.
6.
Introduction: Pelvic serous carcinomas (PSCs) are a controversial entity, which mostly comprise fallopian tube carcinoma (FTC), primary peritoneal carcinoma (PPC) and serous ovarian carcinoma (OC). Despite incremental attention towards understanding pelvic serous carcinogenesis, the gold standard treatment and survival rates have not substantially changed in these last decades.

Areas covered: This review summarizes and gives a critical overview of the ongoing Phase II trials investigating therapies for PSC.

Expert opinion: Several novel molecules have been developed and are currently under investigation for the treatment of PSC, including FTC, PPC and serous OC. The trend of novel targeted agents is one towards individualized, tailored therapy, based on the molecular and biological differences that characterize tumors that seem similar based solely on histological analysis. The task of developing new molecules is particularly difficult for PSC, given the recurrent development of new patterns of drug resistance. However, even if current research is focused towards identifying the best treatments for each woman with a molecularly defined disease, a deeper knowledge of the molecular biology and genetics underlying FTC and its relation as a precursor of PSC is needed.  相似文献   

7.
Transluminal coronary angioplasty was successfully performed in 658 of 752 patients with multivessel disease. An angiographic success was achieved in 1198 of 1358 lesions (88%). One lesion was attempted in 338 patients (45%); 2 in 273 (37%); 3, in 101 (13%); and, 4 or more in 40 cases (5.3%). Significant complications occurred in 39 patients (5.2%): 19 (2.5%) had a transmural infarction; 26 (3.5%) required urgent myocardial revascularization; and 14 (1.9%) died. An apparent lesion recurrence occurred in 233 of 658 (35%) patients with 162 of 171 (95%) having a successful second coronary angioplasty. A second apparent lesion recurrence occurred in 37 of 162 patients (23%) with 24 of 28 (86%) having a successful third coronary angioplasty. Clinical improvement (mean follow-up: 31 +/- 17 months) persisted in 81% of successful patients. The cumulative probability of survival was 91.5% at 72 months. Survival was adversely affected, at 63 months, by the presence of prior bypass surgery (no prior bypass surgery, 94% vs. prior bypass surgery, 86%; p less than 0.05): at 24 months by a low left ventricular ejection fraction (less than or equal to 35%, 82% vs. left ventricular ejection fraction greater than 35%, 95%; p less than 0.01) and, at 57 months, in the multiple dilatation group with prior bypass surgery (no bypass surgery 96% vs. prior bypass surgery 84%; p less than 0.05). Multiple dilatation had a beneficial effect upon survival, at 27 months, in patients with a left ventricular ejection fraction less than or equal to 35% [single dilatation, 74% vs. multiple dilatation, 93%; p less than 0.001], and in patients greater than or equal to 70 years, at 39 months (79% vs. multiple dilatation, 92%; p less than 0.01). These data suggest that coronary angioplasty can be an effective treatment in patients with multivessel coronary disease without the need to dilate all diseased vessels, with good success, acceptable complication rates, and a reasonable expectation of satisfactory long-term clinical improvement.  相似文献   
8.
9.
Between 1979 and 1986, 65 of 76 patients (86%) (82% men, with a mean age of 58 +/- 8 years) with greater than or equal to 2 previous coronary artery bypass grafting (CABG) operations and symptomatic myocardial ischemia underwent successful percutaneous transluminal coronary angioplasty (PTCA). Sixty-two patients had 2 prior CABG operations, 10 had 3 and 4 had 4. Clinical characteristics included prior myocardial infarctions in 49 (65%), severe angina (class III or IV) in 47 (62%) and left ventricular ejection fraction less than or equal to 35% in 13 (17%). There were 139 lesions dilated: 1 lesion in 39 (51%), 2 in 22 (29%) and greater than or equal to 3 in 15 (20%) patients. Arterial lesions were successfully dilated in 71 of 81 cases (88%), vein grafts in 44 of 53 (83%) and mammary artery grafts in 3 of 5 (60%). In 12 patients, PTCA was used to dilate significant lesions less than 15 days after CABG in vessels which were unable to be bypassed. Significant complications were encountered in 4 patients (5%). These included 3 of 53 vein graft dilatations with embolization (6%), with 1 resulting in infarction and death, and 1 patient dying after emergency CABG. At hospital discharge, 65 patients were clinically improved. An apparent symptom-related lesion recurrence occurred in 23 of 65 patients (35%), with 5 patients dying of cardiac causes, 4 having CABG without previous angiography and 12 of 14 patients undergoing repeat successful PTCA (mean time and standard deviation 9 +/- 6 months).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
10.
There has been a debate about the possibility of a link between silicone breast implants and the onset of systemic connective tissue diseases (eg, scleroderma, systemic lupus erythematosus, rheumatoid arthritis) and other inflammatory pathologies, such as silicone implant associated syndrome and adult Still disease. We report a case of adult Still disease in a patient with a silicone gel breast implant. The disease regressed with steroidal treatment, and the patient is now no longer steroid-dependent, although the implant is still in place.  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