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   3132篇
  免费   104篇
  国内免费   20篇
耳鼻咽喉   23篇
儿科学   37篇
妇产科学   49篇
基础医学   425篇
口腔科学   48篇
临床医学   324篇
内科学   682篇
皮肤病学   16篇
神经病学   353篇
特种医学   90篇
外科学   522篇
综合类   5篇
一般理论   1篇
预防医学   176篇
眼科学   23篇
药学   255篇
中国医学   2篇
肿瘤学   225篇
  2023年   13篇
  2022年   25篇
  2021年   58篇
  2020年   25篇
  2019年   41篇
  2018年   71篇
  2017年   26篇
  2016年   45篇
  2015年   62篇
  2014年   97篇
  2013年   163篇
  2012年   216篇
  2011年   249篇
  2010年   113篇
  2009年   121篇
  2008年   238篇
  2007年   242篇
  2006年   239篇
  2005年   216篇
  2004年   218篇
  2003年   206篇
  2002年   225篇
  2001年   32篇
  2000年   33篇
  1999年   33篇
  1998年   48篇
  1997年   44篇
  1996年   22篇
  1995年   20篇
  1994年   22篇
  1993年   13篇
  1992年   14篇
  1991年   7篇
  1990年   7篇
  1989年   7篇
  1988年   4篇
  1987年   3篇
  1986年   6篇
  1985年   2篇
  1984年   6篇
  1983年   7篇
  1981年   3篇
  1980年   4篇
  1979年   2篇
  1976年   1篇
  1970年   1篇
  1964年   1篇
  1963年   1篇
  1961年   1篇
  1959年   2篇
排序方式: 共有3256条查询结果,搜索用时 0 毫秒
61.
62.
63.

Background

Laparoscopic sleeve gastrectomy (LSG) is widely adopted but exposes serious complications.

Methods

A retrospective database analysis was done to study LSG staple line complications in a tertiary referral university center with surgical ICU experienced in treatment of morbid obesity and complications. Twenty-two consecutive patients were referred between January 2004 and February 2012 with postoperative gastric leak or stenosis after LSG. Interventions consisted in the control of intra-abdominal and general sepsis; restoration of staple line continuity or revision of LSG; nutritional support; treatment of associated complications. Main outcome measures concerned success rates of therapeutic strategies, morbidity and mortality rates, LOS, and time to cure.

Results

Thirteen patients (59 %) were referred after failure of reoperation (seven fistula repairs were attempted). Three patients received emergency surgery in our center with transorificial intubation and jejunostomy formation. An endoscopic stent was tried in nine patients but failed in 84.6 % of cases within 20 days (1–161). Seven patients (32 %) necessitated total gastrectomy within 217 days (0–1,915 days) for conservative treatment failure. Procedures under general anesthesia were required in 41 % of cases, organ failure was found in 55 % of cases, and central venous device infection in 40 %. Mortality rate was 4.5 % (n?=?1). Patients with unfavorable evolution of LSG complications (death or additional gastrectomy) had more previous bariatric procedure (82 % vs. 18 %, p?=?0.003). Median time to cure was 310 days (9–546 days).

Conclusions

LSG exposes severe complications occurring in patients with benign condition. Endoscopic stents entail high failure rate. Total gastrectomy is required in one third of the cases.  相似文献   
64.
65.
66.
BackgroundBone turnover (BT) abnormalities are frequently observed in patients with chronic kidney disease. Bone biopsy remains the gold standard for diagnosis; however, its invasive nature has led to its decreased utilisation. The serum parathyroid hormone (PTH) level is not a reliable bone marker (BM) for BT assessment. The latest international recommendations suggest the use of total alkaline phosphatase (t-ALP) or bone-specific alkaline phosphatase (b-ALP), but not ß-CrossLaps (CTX). We compared b-ALP, t-ALP, and CTX levels in patients on haemodialysis (HD).MethodsAll HD patients at a single institution following a standard 3 × 4 to 3 × 5 hours schedule were included in the study, provided they were free from liver disease. Serum intact PTH, t-ALP, b-ALP, and CTX values were compared at baseline and after 18 months of treatment. A kinetic study was performed for pre- and postdialysis CTX values over a 2-week period. We described the longitudinal evolution of these BMs in two typical patients.ResultsA total of 98 patients on HD (46% female) were evaluated. The mean age was 69.8 ± 11 years and the mean duration of dialysis was 54.4 ± 61 months. At baseline, CTX (2.1 ± 1 μg/L) correlated well with b-ALP (18 ± 11 μg/L; r = 0.64; P < 0.001) and PTH (221 ± 165 pg/mL; r = 0.62; P < 0.001). The changes in these values at 18 months were also correlated (ΔCTX compared with Δb-ALP: r = 0.51; P < 0.001; Δb-ALP compared with ΔPTH: r = 0.37, P < 0.01). b-ALP and t-ALP (245 ± 132 U/L) were closely correlated (r = 0.78), as was their variation over 18 months (r = 0.67), but t-ALP did not correlate with PTH, and correlated poorly with CTX (r = 0.38). The CTX reduction ratio during standard dialysis was approximately 70 to 75% over each session, although predialysis values remained stable.ConclusionIn HD patients, mean CTX values are five times higher than the normal range. CTX appears to be an alternative to b-ALP for assessing BT. b-ALP remains the standard BM, despite being expensive, infrequently available in many laboratories, and not useful for patients with liver disease.  相似文献   
67.
68.
Diseases that affect the thoracolumbar junction present a unique challenge to the spine surgeon. Various techniques have been described to treat this clinical entity from the anterior, lateral, or posterior direction. These can be associated with significant morbidity due to extensive tissue dissection, blood loss, and postoperative pain leading to a lengthy recovery. The use of a tubular retractor allows the surgeon to minimize tissue dissection and potentially reduce approach-related morbidity while obviating the need for an approach surgeon for exposure. The surgical technique of a minimally invasive lateral approach to the thoracolumbar junction for corpectomy is described in detail and two illustrative patients are presented.  相似文献   
69.
The recently published results of the sequential treatment of postmenopausal osteoporotic women with subcutaneous abaloparatide (80 µg/day) (ABL) for 18 months followed by 6 months of oral alendronate (70 mg/week) (ALN) support the administration of an anti-resorptive agent after completion of a treatment course with an osteoanabolic agent. The ABL/ALN sequence resulted in greater bone mineral density gains at all skeletal sites and in a reduction of vertebral, non-vertebral, major and clinical fractures compared to what is observed after 18 months of placebo followed by 6 months of ALN. Whereas questions remained unanswered about the ideal anti-resorptive agent to be used after ABL, the optimal duration of the administration of the anti-resorptive drug or the potential interest of re-initiating a course of ABL after a limited administration of ALN, these results support the use of the ABL/ALN sequence in the management of postmenopausal osteoporosis.  相似文献   
70.
OBJECTIVES: Bartonella bacilliformis is the aetiological agent of Carrion's disease. Although ciprofloxacin, rifampicin and erythromycin have been successfully used in the treatment of the disease, failures and relapses have been reported. The objective of our study was to select in vitro mutants resistant to antibiotics in order to determine the frequency of mutations and to characterize the mechanism of resistance at the molecular level. METHODS: Antibiotic-resistant mutants were selected by serial passages of bacteria on blood agar plates containing antibiotics. Candidate genes involved in resistance were amplified and sequenced and compared in order to look at mutations associated with antibiotic resistance. RESULTS: Ciprofloxacin-, rifampicin- and erythromycin-resistant mutants were obtained after five, three and four passages, respectively. Conversely, no mutant was obtained with either gentamicin or doxycycline even after 16 passages. The ciprofloxacin mutant contained an amino acid change at position 87 (Asp --> Asn) in its quinolone resistance-determining region of the DNA gyrase protein, whereas the rifampicin-resistant strain had an amino acid change at position 531 (Ser --> Phe) in the rifampicin resistance-determining region of the rpoB gene. Similarly, the erythromycin-resistant mutant showed an A2058G mutation in the 23S rRNA gene. CONCLUSIONS: According with the current knowledge on the treatment of human bartonellosis, we believe that doxycycline in association with gentamicin may be the preferred regimen for the treatment of the acute and eruptive stages of Carrion's disease, but clinical trials are warranted to support our findings.  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