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   605篇
  免费   39篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   9篇
妇产科学   14篇
基础医学   77篇
口腔科学   3篇
临床医学   64篇
内科学   118篇
皮肤病学   6篇
神经病学   33篇
特种医学   21篇
外科学   187篇
综合类   3篇
预防医学   18篇
眼科学   1篇
药学   42篇
肿瘤学   47篇
  2023年   2篇
  2022年   7篇
  2021年   14篇
  2020年   10篇
  2019年   32篇
  2018年   28篇
  2017年   11篇
  2016年   7篇
  2015年   17篇
  2014年   28篇
  2013年   22篇
  2012年   53篇
  2011年   47篇
  2010年   13篇
  2009年   21篇
  2008年   42篇
  2007年   47篇
  2006年   43篇
  2005年   31篇
  2004年   26篇
  2003年   15篇
  2002年   22篇
  2001年   8篇
  2000年   12篇
  1999年   9篇
  1998年   4篇
  1997年   5篇
  1996年   4篇
  1995年   4篇
  1994年   4篇
  1992年   3篇
  1990年   6篇
  1989年   4篇
  1988年   5篇
  1987年   6篇
  1986年   2篇
  1985年   2篇
  1984年   4篇
  1982年   6篇
  1981年   2篇
  1980年   2篇
  1979年   2篇
  1975年   1篇
  1973年   2篇
  1968年   1篇
  1911年   1篇
  1904年   1篇
  1900年   2篇
  1899年   1篇
  1898年   1篇
排序方式: 共有646条查询结果,搜索用时 15 毫秒
51.
Klatte and coworkers examined the prognostic relevance of capsular involvement with no invasion of the perinephric fat and collecting system invasion in a series of 519 patients with intracapsular renal cell carcinoma (RCC) treated with partial or radical nephrectomy and followed for a median of 49 mo (range: 1-199 mo).Capsular involvement and collecting system invasion were reported in 21.6% and 7.5% of patients, respectively. Capsular involvement was significantly associated with a higher nuclear grade and larger tumors, whereas collecting system invasion was significantly associated only with microvascular invasion. In addition, capsular involvement and collecting system invasion were not associated with each other, but had a significant impact on recurrence-free survival (p = 0.007 and p < 0.001, respectively). Interestingly, patients with capsular involvement had the same recurrence-free survival as patients diagnosed as having pT3a N0 M0 RCC. In multivariate analysis, both capsular involvement and collecting system invasion were independent predictors of recurrence-free survival with a reported risk ratio of 1.84 and 3.78, respectively.  相似文献   
52.
INTRODUCTION: Surgical site infections are the second most common cause of nosocomial infections and, typically, gram-positive pathogens are involved. MATERIALS AND METHODS: A mouse model was used to investigate the efficacy of different methods for the treatment of wound infections. A full thickness wound was established on the back subcutaneous tissue of adult male BALB/c mice. A small gauze was placed over each wound and then inoculated with 5 x 10(7) colony-forming units of Staphylococcus aureus. The study included a control group that did not receive any treatment and four contaminated groups treated, respectively, with: (1) drug-free Allevyn (Smith and Nephew Healthcare, Yorkshire, United Kingdom), (2) teicoplanin-soaked Allevyn, (3) drug-free Allevyn and daily intraperitoneal teicoplanin (7 mg/kg) and, finally, (4) teicoplanin-soaked Allevyn and daily intraperitoneal teicoplanin (7 mg/kg). Main outcome measures were quantitative bacterial culture, assessment of vascular endothelial growth factor (VEGF) plasma levels, histological examination with assessment of microvessel density, and of VEGF expression in tissue sections. RESULTS: Data analysis showed that strong inhibition of bacterial growth was achieved in any group treated with intraperitoneal teicoplanin. However, the highest inhibition of bacterial growth was obtained in the group that received teicoplanin-soaked Allevyn and intraperitoneal teicoplanin. Histological examination showed that each treatment modality was able to reduce the delay in wound repair. The most effective treatment appeared to be the local application of teicoplanin-soaked hydro gel foam. The tissue effects were associated with an increase in neovascularization and VEGF expression by endothelial cells and fibroblasts in the granulation tissue. Bacterial colonies also were reduced, especially when teicoplanin was given parenterally. CONCLUSIONS: Soaking a hydro cellular foam with an antistaphylococcal agents, such as teicoplanin, may be useful for the management of infected wounds.  相似文献   
53.
Simple enucleation for the treatment of renal angiomyolipoma   总被引:1,自引:0,他引:1  
OBJECTIVES: To report on the role of simple enucleation for treating renal angiomyolipoma (AML) in a series of patients treated in our department. PATIENTS AND METHODS: We retrospectively reviewed the data of all 37 patients with a histopathological diagnosis of renal AML who had either radical nephrectomy (three) or nephron-sparing surgery by simple enucleation (34) between January 1986 and December 2005. Indications for intervention included either symptomatic AML or a tumour of >4 cm, regardless to the presence of symptoms or renal masses suspicious of malignancy. The patients' status was evaluated last in October 2006. RESULTS: The mean (sd, median, range) pathological tumour size was 5.2 (3.4, 4.8, 1.5-15) cm; five patients (15%) were affected by tuberous sclerosis. Simple enucleation was successful in all patients but in three (9%) a sharp dissection a few millimetres from the tumour was used during critical steps of the procedure where it seemed difficult to define the right plane of enucleation. Warm ischaemia was used in 79% of patients, with a mean ischaemic time of 11.2 min. Two patients (6%) required renal hypothermia. A simple parenchymal compression was used in five cases (15%). The mean (range) intraoperative blood loss was 170 (70-650) mL. None of the patients had postoperative bleeding requiring re-intervention but one (3%) required two units of blood after surgery. There were no major complications, e.g. prolonged acute tubular necrosis/chronic renal insufficiency and urinary leakage/urinoma, but two patients had urosepsis not associated with perirenal fluid collection and that required targeted antibiotic therapy. At a mean (median, range) follow-up of 56 (50.5, 10-120) months none of the patients had local tumour recurrence. Two patients had a small AML elsewhere in the operated kidney, detected 18 and 36 months after surgery, with a kidney recurrence rate of 6%. CONCLUSIONS: Our data confirm the optimum results of simple enucleation for renal AMLs; this technique provides excellent long-term local control and no patient had urinary leakage/fistula afterward.  相似文献   
54.
Silybin, a main component of the milk thistle of Silybum marianum, has been reported to possess anticancer activity. We investigated the effects of IdB 1016, a complex of silybin with phosphatidylcholine, on the development of mammary tumors appearing spontaneously in HER-2/neu transgenic mice. The mechanisms involved in the antitumor effect of IdB 1016 were evaluated by studying the apoptosis, senescent-like growth arrest, intratumoral leukocyte infiltrate, and the expression of HER-2/neu and p53 in tumoral mammary glands from transgenic mice and in human breast SKBR3 tumor cells. The administration of IdB 1016 delayed the development of spontaneous mammary tumors, reduced the number and size of mammary tumor masses, and diminished lung metastasization in HER-2/neu transgenic mice. In tumoral mammary glands from IdB 1016-treated mice, a down-regulation of HER-2/neu gene expression was associated with an increased senescent-like growth arrest of tumor cells, and an increased infiltrate of neutrophils, CD4, and CD8 T cells. Both senescent-like growth arrest and apoptosis were significantly increased and were associated with a reduced p185(HER-2/neu) protein and an increased p53 mRNA in SKBR3 in vitro treated with IdB 1016 in comparison with control cells. The results show the antitumor effect of IdB 1016 in the development of spontaneous mammary tumors in HER-2/neu transgenic mice. The effect of IdB 1016 might be related to the down-regulation of HER-2/neu expression and the induction of senescent-like growth arrest and apoptosis through a p53-mediated pathway in tumor cells.  相似文献   
55.
56.
PURPOSE: Long-term renal function is crucial in orthotopic bladder substitutions, and can be influenced by several factors including ureteral obstruction, urinary infection and reflux. In this study we investigated the prevalence of renal functional impairment and the incidence of morphological alterations of the upper urinary tract in patients who had a low pressure ileal neobladder constructed with no antireflux mechanism. MATERIALS AND METHODS: From 1996 to 2002, 70 men received a W-shaped neobladder using refluxing ureterointestinal anastomoses and short afferent limb. Final evaluation of patient status was in November 2003. A total of 20 patients died during followup and mean followup of the remaining 50 patients was 50 months (range 21 to 89). Kidney morphology was evaluated using technetium diethylenetetraminepentaacetic acid nuclear renography and ultrasonography. Total and separate renal function were evaluated by measuring plasma creatinine and glomerular filtration rate (GFR), the latter measured as the renal clearance of technetium diethylenetetraminepentaacetic acid. Measured values of GFR were compared with the results from a group of healthy subjects of the same age. RESULTS: The anastomotic stricture rate was 4%, 2 severe strictures occurred 2 and 4 months after surgery, while 2 moderate strictures were detected with renal scans during the study. Renal scintigraphy revealed an excretory phase within the normal range in 67 of 99 renoureteral units (68%), a short delay in collecting system drainage associated with mild and transient pelvicaliceal dilatation in 23 (23%), and dilatation of the upper urinary tract in the remaining 9 (9%) including obstructive in 2 (2%) and not obstructive in 7 (7%). Mean (+SD) total GFR of the patients was 89.7 (19.6) ml per minute per 1.73 m. Mean total GFR of the control group was 90.6 (11.4) ml per minute per 1.73 m. The comparison between measured GFR of patients and the control group showed no statistically significant difference. CONCLUSIONS: Our medium-term data support the assumption that the lack of any antireflux mechanism in orthotopic neobladder, per se, has no detrimental effect on renal function.  相似文献   
57.
OBJECTIVE: To investigate the efficacy of imipenem, piperacillin combined with cecropin B in the prevention of lethality in 2 rat models of septic shock. Main outcome measures were bacterial growth in blood and intra-abdominal fluid, endotoxin and TNF-alpha concentrations in plasma, and lethality. BACKGROUND: Sepsis remains a serious clinical problem despite intense efforts to improve survival. It is a major cause of morbidity and mortality in hospitalized patients. The primary cause of Gram-negative shock results from activation of host effector cells by endotoxin, the lipopolysaccharide (LPS) associated with cell membranes of Gram-negative bacteria. METHODS: Adult male Wistar rats were given (1). an intraperitoneal injection of 1 mg of Escherichia coli 0111:B4 LPS or (2). 2 x 1010 CFU of E. coli ATCC 25922. All animals were randomized to receive intraperitoneally isotonic sodium chloride solution, 1 mg/kg cecropin B, 20 mg/kg imipenem, and 120 mg/kg piperacillin alone and combined with 1 mg/kg cecropin B. Each group included 20 animals.RESULTS All compounds reduced the lethality when compared with controls. Piperacillin and imipenem significantly reduced the lethality and the number of E. coli in abdominal fluid compared with saline treatment. On the other hand, each betalactam determined an increase of plasma endotoxin and TNF-alpha concentration. Combination between cecropin B and betalactams showed to be the most effective treatment in reducing all variables measured. CONCLUSION: Cecropin B enhances betalactams activities in Gram-negative sepic shock rat models.  相似文献   
58.
This study investigated the in‐season effect of intensified training comparing the efficacy of duration‐matched intense intermittent exercise training with sprint interval training in increasing intermittent running performance, sprint ability, and muscle content of proteins related to ion handling and metabolism in football players. After the first two weeks in the season, 22 sub‐elite football players completed either 10 weeks of intense intermittent training using the 10‐20‐30 training concept (10‐20‐30, n = 12) or sprint interval training (SIT, n = 10; work/rest ratio: 6‐s/54‐s) three times weekly, with a ~20% reduction in weekly training time. Before and after the intervention, players performed a Yo‐Yo intermittent recovery test level 1 (Yo‐Yo IR1) and a 30‐m sprint test. Furthermore, players had a muscle biopsy taken from the vastus lateralis. Yo‐Yo IR1 performance increased by 330 m (95%CI: 178‐482, P ≤ 0.01) in 10‐20‐30, whereas no change was observed in SIT. Sprint time did not change in 10‐20‐30 but decreased by 0.04 second (95%CI: 0.00‐0.09, P ≤ 0.05) in SIT. Muscle content of HADHA (24%, P ≤ 0.01), PDH‐E1α (40%, P ≤ 0.01), complex I‐V of the electron transport chain (ETC) (51%, P ≤ 0.01) and Na+, K+‐ATPase subunits α2 (33%, P ≤ 0.05) and β1 (27%, P ≤ 0.05) increased in 10‐20‐30, whereas content of DHPR (27%, P ≤ 0.01) and complex I‐V of the ETC (31%, P ≤ 0.05) increased in SIT. Intense intermittent training, combining short sprints and a high aerobic load, is superior to regular sprint interval training in increasing intense intermittent running performance during a Yo‐Yo IR1 test and muscle content of PDH‐E1α and HADHA in sub‐elite football players.  相似文献   
59.
BACKGROUND: Recurrent cough can be a clinical manifestation of rhinitis. However, it remains unclear if the association between rhinitis and recurrent cough among children is independent of asthma. OBJECTIVE: The aim of the present study was to determine, in a large longitudinal cohort, whether rhinitis is significantly associated with recurrent cough alone, wheezing alone, or the combination of both symptoms during childhood. METHODS: We investigated determinants of recurrent cough, with or without wheezing, using longitudinal data from the Tucson Children's Respiratory Study. Among the 1246 subjects originally enrolled, 1024 children completed at least one questionnaire between the ages of 6 and 18 years and were included in the present study. In any survey, wheezing was defined as at least one wheezing episode during the past year and recurrent cough as two or more coughing episodes lasting at least 1 week without a cold during the past year. Generalized estimating equations were used to determine significant risk factors. RESULTS: After adjusting for sex, skin test reactivity and parental asthma, both rhinitis (OR = 2.47 CI = 1.84, 3.30) and sinusitis (OR = 1.54 CI = 1.11, 2.14) were associated with an increased risk of recurrent cough plus wheezing. The OR associated with rhinitis were significantly reduced for subjects reporting only recurrent cough or only wheezing (OR = 1.43, CI = 1.03, 1.99; and OR = 1.30, CI = 1.07, 1.58, respectively). Recurrent cough and wheezing, when examined independently, showed different patterns of risk factors. CONCLUSION: We found rhinitis to be an independent risk factor for both recurrent cough and wheezing during childhood. Different pathways may be involved in the association of rhinitis with recurrent cough and wheezing.  相似文献   
60.
OBJECTIVE: To investigate the effectiveness of a body mass reduction programme entailing diet caloric restriction and moderate physical activity with or without supplementary treatment with recombinant (r) GH or steroids to improve body composition and muscle performance in severely obese women aged 61-75 years. METHODS: Twenty women were randomly assigned to one of three groups: body mass reduction alone; body mass reduction plus rGH; body mass reduction plus nandrolone undecanoate. Body composition, isotonic muscle strength and anaerobic power output during jumping were determined before and after the 3-week period. RESULTS: Whatever the experimental group considered, body mass (P<0.01), body mass index (P<0.05) and fat mass (P<0.05) decreased significantly, whereas muscle strength and power increased significantly (P<0.05) after the intervention. CONCLUSION: Small body mass reductions after 3 weeks of energy-restricted diet combined with moderate aerobic and strength exercise are associated with significant improvements in upper and lower limb muscle strength and power and reduction of fat mass in severely obese women aged 61-75 years. Although the association of rGH or nandrolone undecanoate does not appear to exert additional effects on body composition and muscle performance attained by body mass reduction alone, further additional studies with larger study groups, different dosages and more prolonged periods are required for definitive conclusions to be drawn.  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