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   2277篇
  免费   134篇
  国内免费   16篇
耳鼻咽喉   21篇
儿科学   115篇
妇产科学   34篇
基础医学   220篇
口腔科学   24篇
临床医学   198篇
内科学   489篇
皮肤病学   19篇
神经病学   288篇
特种医学   66篇
外科学   414篇
综合类   14篇
一般理论   1篇
预防医学   87篇
眼科学   97篇
药学   228篇
中国医学   1篇
肿瘤学   111篇
  2024年   3篇
  2023年   18篇
  2022年   35篇
  2021年   76篇
  2020年   60篇
  2019年   84篇
  2018年   105篇
  2017年   71篇
  2016年   73篇
  2015年   62篇
  2014年   96篇
  2013年   126篇
  2012年   216篇
  2011年   243篇
  2010年   104篇
  2009年   75篇
  2008年   175篇
  2007年   160篇
  2006年   110篇
  2005年   114篇
  2004年   107篇
  2003年   107篇
  2002年   88篇
  2001年   8篇
  2000年   6篇
  1999年   14篇
  1998年   7篇
  1997年   10篇
  1996年   9篇
  1995年   9篇
  1994年   3篇
  1993年   3篇
  1992年   9篇
  1991年   4篇
  1990年   2篇
  1989年   5篇
  1988年   6篇
  1987年   2篇
  1986年   5篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1978年   2篇
  1976年   1篇
  1959年   1篇
  1925年   2篇
  1924年   4篇
  1908年   1篇
排序方式: 共有2427条查询结果,搜索用时 390 毫秒
51.
This post hoc analysis of the Assessing The Treatment Effect in Metabolic Syndrome Without Perceptible diabeTes (ATTEMPT) study assesses the 3? year incidence of new-onset diabetes (NOD) and related cardiovascular disease (CVD) events in patients with metabolic syndrome (MetS), after multifactorial (lifestyle and drug, including atorvastatin) intervention. Patients were randomized to group A (low-density lipoprotein cholesterol [LDL-C] target < 100 mg/dL) and group B (< 130 mg/dL). The incidence of NOD during the 42-month follow-up was very low, 0.83 to 1.00/100 patient-years in patients with MetS and MetS with impaired fasting glucose, respectively. Older age, increased waist circumference, and persistent MetS were determinants of NOD. One CVD nonfatal event occurred in the 28 patients with NOD. Our findings suggest that treating the characteristics of MetS is achievable and beneficial. New-onset diabetes incidence and CVD events were negligible and not different from what is expected in the general population.  相似文献   
52.
Maintenance of normal potassium (K(+)) homeostasis has become an increasingly important limiting factor in the therapy of heart failure (HF). With the application of loop diuretics and digoxin, hypokalemia has become a frequent and feared side effect of treatment. Low serum K(+) in HF may be also a marker of increased neurohormonal activity and disease progression. To gain the maximum benefit from treatment, we need to individualize drug use and carefully monitor electrolytes. Symptomatic HF patients (New York Heart Association class III-IV) should be prescribed the lowest dose of diuretic necessary to maintain euvolemia. Mild hypokalemia may be corrected by the use of aldosterone receptor antagonists such as spironolactone or eplerenone. However, a more severe hypokalemia should preferably be corrected using K(+) supplement. Serum K levels should be frequently checked and maintained between 4.0 and 5.5 mEq/l (mmol/l).  相似文献   
53.
The inflammatory myopathies are an important and treatable group of disorders. The diagnostic criteria and the classifications are complex and subject to debate. Furthermore, there is clinical and histopathological overlap between the features of inflammatory myopathies and those of adult-onset genetic myopathies. In this review, we will discuss the two more common pitfalls in inflammatory myopathies diagnosis: firstly, the misdiagnosis between different types of inflammatory myopathies and uncommon myopathies; secondly, the confusion between inflammatory myopathies and genetic myopathies. Among the group of limb-girdle dystrophies, dysferlinopathies are the more common confounding myopathies. An accurate diagnosis is essential for an optimal management in patients with myopathies.  相似文献   
54.
55.

Introduction

The effect of cardiovascular disease (CVD) prevention measures aimed at elderly patients requires further evidence. We investigated the effect of statin treatment (targeted to achieve guideline goals) on CVD outcomes in different age groups to determine whether statins are more beneficial in the elderly.

Material and methods

The primary endpoint of this post hoc analysis of the GREek Atorvastatin and Coronary-heart-disease Evaluation (GREACE) study (n = 1,600 patients with established coronary heart disease (CHD), mean follow-up 3 years) was the absolute and relative CVD event (a composite of death, myocardial infarction, revascularization, unstable angina, heart failure and stroke) risk reduction in age quartiles (each n = 200). Patients on “structured care” with atorvastatin (n = 800) followed up by the university clinic and treated to lipid goal were compared with the corresponding quartiles on “usual care” (n = 800) followed up by specialists or general practitioners of the patient''s choice outside the hospital.

Results

In the elderly (mean age 69 ±4 and 70 ±3 years in the “structured” and “usual care”, respectively) the absolute CVD event reduction between “structured” and “usual care” was 16.5% (p < 0.0001), while in the younger patients (mean age 51 ±3 years and 52 ±3 years in the “structured” and “usual care”, respectively) this was 8.5% (p = 0.016); relative risk reduction (RRR) 60% (p < 0.0001) vs. 42% respectively (p = 0.001). The elderly had higher rates of chronic kidney disease and higher uric acid levels, plus an increased prevalence of diabetes, metabolic syndrome and non-alcoholic fatty liver disease. These factors might contribute to the increased CVD risk in older patients.

Conclusions

All age groups benefited from statin treatment, but the elderly on “structured care” had a greater absolute and relative CVD risk reduction than the younger patients when compared with the corresponding patients assigned to “usual care”. These findings suggest that we should not deprive older patients of CVD prevention treatment and lipid target achievement.  相似文献   
56.

Background:

Some in vitro studies warn combining different metals in orthopedic surgery. The aim of this study is to determine the impact of combining titanium and stainless steel on bone healing and the clinical course of patients undergoing internal fixation of femoral fractures.

Materials and Methods:

69 patients with femoral fractures had polyaxial locking plate osteosynthesis. The locking plate was made of a titanium alloy. Two different cohorts were defined: (a) sole plating and (b) additional stainless steel cerclage wiring. Postoperative radiographs and clinical followup were performed at 6 weeks, 3 months and 12 months.

Results:

Cohorts A and B had 36 and 33 patients, respectively. Patient demographics and comorbidities were similar in both groups. In two cases in cohort A, surgical revision was necessary. No complication could be attributed to the combination of titanium and stainless steel.

Conclusion:

The combination of stainless steel cerclage wires and titanium plates does not compromise fracture healing or the postoperative clinical course.  相似文献   
57.

Background

Sublobar resection for non–small cell lung cancer (NSCLC) remains controversial owing to concern about local recurrence and long-term survival outcomes. We sought to determine the efficacy of wedge resection as an oncological procedure.

Methods

We analyzed the outcomes of all patients with NSCLC undergoing surgical resection at the Cancer Centre of Southeastern Ontario between 1998 and 2009. The standard of care for patients with adequate cardiopulmonary reserve was lobectomy. Wedge resection was performed for patients with inadequate reserve to tolerate lobectomy. Predictors of recurrence and survival were assessed. Appropriate statistical analyses involved the χ2 test, an independent samples t test and Kaplan–Meier estimates of survival. Outcomes were stratified for tumour size and American Joint Committee on Cancer seventh edition TNM stage for non–small cell lung cancer.

Results

A total of 423 patients underwent surgical resection during our study period: wedge resection in 71 patients and lobectomy in 352. The mean age of patients was 64 years. Mean follow-up for cancer survivors was 39 months. There was no significant difference between wedge resection and lobectomy for rate of tumour recurrence, mortality or disease-free survival in patients with stage IA tumours less than 2 cm in diameter.

Conclusion

Wedge resection with lymph node sampling is an adequate oncological procedure for non–small cell lung cancer in properly selected patients, specifically, those with stage IA tumours less than 2 cm in diameter.  相似文献   
58.
59.

Purpose

At the time of castration resistance, it is recommended to realize hormonal manipulations before chemotherapy. We evaluated the impact of a switch from GnRH agonist to antagonist in patients with castration-resistant prostate cancer on PSA and testosterone levels at 3 months.

Methods

Retrospectively, 17 patients from 5 different centers undergoing androgen deprivation therapy and presenting rising PSA confirmed on 3 blood samples 2 weeks apart and despite a castrate testosterone level (<0.5 ng/ml) were reviewed. Antiandrogen withdrawal syndrome had been tested before the switch. Degarelix was administered as followed: 240 mg for the first injection and then 80 mg every month, subcutaneously. We evaluated the PSA and testosterone level variation 3 months after the switch. Patients who experienced a variation in PSA of less than 10% compared to the baseline or who had a more than 10% PSA decrease were defined as responders.

Results

Mean PSA level at the switch was 34.3 ± 50.3 ng/ml, with a mean testosterone level of 0.21 ± 0.13 ng/ml. Three months after the switch, mean PSA level was 59.9 ± 81.6 ng/ml (P = 0.061), with a mean testosterone level of 0.19 ± 0.08 ng/ml (P = 0.086). At 3 months, 4 patients (23%) responded to therapy. Thirteen patients (77%) experienced a rise in PSA of more than 10% compared to baseline; 41% of patients decreased their testosterone level. The limitations of this study are its retrospective nature and the limited number of patients.

Conclusion

Switch from an agonist to an antagonist of GnRH has a limited impact on PSA at 3 months in castration-resistant prostate cancer patients.  相似文献   
60.

Background

Postoperative pancreatic fistula (PPF) is the most frequent and serious complication after laparoscopic distal pancreatectomy (LDP). Our goal was to compare the performance, in terms of PPF prevention, and safety of a radiofrequency (RF)-assisted transection device versus a stapler device in a porcine LDP model.

Methods

Thirty-two animals were randomly divided into two groups to perform LDP using a RF-assisted device (RF group; n = 16) and stapler device (ST group; n = 16) and necropsied 4 weeks after surgery. The primary endpoint was the incidence of PPF. Secondary endpoints were surgery/transection time, intra/postoperative complications/deaths, postoperative plasmatic amylase and glucose concentration, peritoneal liquid amylase and interleukin 6 (IL-6) concentrations, weight variations, and histopathological changes.

Results

Two clinical and one biochemical PPF were observed in the ST and RF groups respectively. Peritoneal amylase concentration was significantly higher in the RF group 4 days after surgery, but this difference was no longer present at necropsy. Both groups presented a significant decrease in peritoneal IL-6 concentration during the postoperative follow-up, with no differences between the groups. RF group animals showed a higher postoperative weight gain. In the histopathological exam, all RF group animals showed a common pattern of central coagulative necrosis of the parenchymal surface, surrounded by a thick fibrosis, which sealed main and secondary pancreatic ducts and was not found in ST group.

Conclusions

The fibrosis caused by an RF-assisted device can be at least as safe and effective as stapler compression to achieve pancreatic parenchyma sealing in a porcine LDP model.  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