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   1660篇
  免费   78篇
  国内免费   5篇
耳鼻咽喉   27篇
儿科学   55篇
妇产科学   73篇
基础医学   110篇
口腔科学   123篇
临床医学   144篇
内科学   308篇
皮肤病学   16篇
神经病学   166篇
特种医学   90篇
外科学   429篇
综合类   23篇
一般理论   1篇
预防医学   36篇
眼科学   36篇
药学   66篇
肿瘤学   40篇
  2024年   1篇
  2023年   16篇
  2022年   27篇
  2021年   78篇
  2020年   46篇
  2019年   52篇
  2018年   80篇
  2017年   38篇
  2016年   66篇
  2015年   85篇
  2014年   88篇
  2013年   102篇
  2012年   152篇
  2011年   136篇
  2010年   62篇
  2009年   63篇
  2008年   108篇
  2007年   124篇
  2006年   96篇
  2005年   88篇
  2004年   70篇
  2003年   53篇
  2002年   35篇
  2001年   20篇
  2000年   12篇
  1999年   9篇
  1998年   4篇
  1997年   4篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1990年   2篇
  1989年   3篇
  1987年   3篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1972年   1篇
  1911年   1篇
排序方式: 共有1743条查询结果,搜索用时 31 毫秒
91.

INTRODUCTION

Giant cervical and mediastinal goiter may lead to acute respiratory failure caused by laryngotracheal compression and airway obstruction. Here, we present a case admitted to the emergency service with a giant goiter along with respiratory failure and poor general health status, which required urgent surgical intervention.

PRESENTATION OF CASE

A 71-year-old female admitted to the emergency room with shortness of breath and poor general health status resulting from a giant cervical swelling progressively increased during the last 7 years and constituted severe respiratory failure which has become severe in the last one month. A giant nodular goiter of the left thyroid lobe extending retrosternally, causing tracheal compression, limiting the neck movements was detected with clinical examination and bedside ultrasound. Emergency thyroidectomy was planned. Fiberoptic-assisted awake nasal intubation was performed in the operating room. Emergency total thyroidectomy was performed for the life-threatening respiratory failure. Postoperative period was uneventful. She was transferred from intensive care unit to the ward on postoperative day 3 and was discharged from the hospital on the postoperative 7th day. Benign multinodular hyperplasia was reported on the histopathological report. Patient was included in routine follow-up.

DISCUSSION

In the present case tracheal destruction due to compression of the giant goiter was found in agreement with previous reports. Emergency thyroidectomy was performed after awake intubation since it is a common surgical option for the treatment of giant goiter causing severe airway obstruction.

CONCLUSION

Respiratory failure due to giant nodular goiter is a life-threatening situation and should be treated immediately by performing awake endotracheal intubation following emergency total thyroidectomy.  相似文献   
92.

INTRODUCTION

Synovial chondromatosis is characterized by the presence of metaplastic cartilage nodules originating from the synovia, bursa and tendon sheaths. Although it is extremely rare in the ankle joint, malignant transformation is possible. The choice of treatment is usually open surgery for excision of loose bodies and synovectomy. Limited data is available concerning arthroscopic approaches.

PRESENTATION OF CASE

A 28-year-old male patient was evaluated for pain and swelling of the right ankle joint. Based on the findings of physical examination and radiographic investigations, arthroscopic surgery was performed due to ankle impingement syndrome. A diagnosis of synovial osteochondromatosis was made following the pathological survey.

DISCUSSION

Synovial chondromatosis is slowly progressive and is considered to be a self-limiting situation. Treatment strategies are decided on according to the patient''s complaints, age and disease stage. Open or arthroscopic surgery. can be performed. Some advantages of arthroscopic surgery are wide visualization areas, easy access to areas difficult to reach, lower morbidity, no necessity for casting and immobilization, early rehabilitation and quick recovery period.

CONCLUSION

In conclusion, arthroscopic management can be successful in selected patients with synovial osteochondromatosis localized to the ankle joint.  相似文献   
93.
Purpose: Urinary stones are common and can be diagnosed with computed tomography (CT) easily. In this study, we aimed to specify the opacity characteristics of various types of calcified foci that develop through the urinary system by using an image analysis program. With this method, we try to differentiate the calculi from the non-calculous opacities and also we aimed to present how to identify the characteristic features of renal and ureteral calcules. Materials and methods: We obtained the CT studies of the subjects (n?=?48, mean age?=?41 years) by using a dual source CT imaging system. We grouped the calculi detected in the dual-energy CT sections as renal (n?=?40) or ureteric (n?=?45) based on their locations. Other radio-opaque structures that were identified outside but within close proximity of the urinary tract were recorded as calculi “mimickers”. We used ImageJ program for morphological analysis. All the acquired data were analyzed statistically. Results: According to thorough morphological parameters, there were statistically significant differences in the angle and Feret angle values between calculi and mimickers (p?p?=?0.003) and kidney (p?=?0.001) stones. Conclusions: Computer-based morphologic parameters can be used simply to differentiate between calcular and noncalcular densities on CT and also between renal and ureteric stones.  相似文献   
94.

Purpose

Taurine, the major intracellular free amino acid found in high concentrations in mammalian cells, is known to be an endogenous antioxidant and a membrane-stabilizing agent. It was hypothesized that taurine may be effective in reducing ischemia–reperfusion injury after lung transplantation and an experimental study was conducted in a rat model.

Methods

The number of Sprague–Dawley rats used in the study was 35. Animals were randomized into five groups of 7 rats each, including control, donor I, donor II, ischemia–reperfusion injury, and treatment groups. All animals were exposed to the same experimental conditions in the preoperative period. Rats were fixed in a supine position after the induction. After the rats were shaved, a left pneumonectomy was performed following sternotomy in control, donor I, and donor II groups. The harvested grafts in donor I and donor II groups were transplanted to the rats of the ischemia–reperfusion group and treatment group, respectively. However, taurine was administered intraperitoneally for 3 days before the harvesting procedure in donor II. All harvested lungs were kept in a Euro-Collins solution at +4 °C for 24 h in a half-inflated manner. After harvesting and transplantation, lungs were sampled for histopathological and biochemical analysis.

Results

Malondialdehyde and superoxide dismutase, glutathione peroxidase, and catalase levels were lower in the treatment group than the other groups (p < 0.05). Histopathological findings were better in treatment group than the ischemia–reperfusion group (p < 0.05).

Conclusion

It was demonstrated that donor treatment with taurine resulted in preservation of transplanted lung tissue in respect to histopathological and biochemical findings.  相似文献   
95.

Purpose

The present study was conducted to examine if preinsertion lumbar ultrasound scanning helps with performance of spinal puncture, as a tool for decreasing the number of puncture attempts and spinal procedure time and increasing the success rate. We hypothesized that ultrasound can facilitate neuraxial blockade, particularly in pregnant women with difficult topographic anatomy.

Methods

One hundred (50 lean, BMI <30 kg/m2, and 50 obese, BMI ≥30 kg/m2) parturients scheduled for cesarean delivery were divided into ultrasound and control groups. Subarachnoid block was performed with prepuncture ultrasound examination in lean parturients (group 1, n = 25) and in obese parturients (group 2, n = 25), and subarachnoid block was performed without prepuncture ultrasound examination in lean parturients (group 3, n = 25) and in obese parturients (group 4, n = 25). The number of puncture attempts and puncture levels were recorded.

Results

A lower number of puncture attempts and fewer puncture levels were detected in ultrasound (US) groups (p < 0.001). First attempt success rate under US guidance was 92 % in comparison to 44 % using a conventional technique in obese parturients (p < 0.001). In 52 % of the lean patients and in 54.2 % of the obese patients, the intercristal line was at the L3–L4 and at the L2–L3 interspace, respectively. The duration of spinal procedure was shorter in US groups (22 vs. 52 s, p = 0.031). We found a high correlation between ultrasound and needle depth (r = 0.709, p < 0.001).

Conclusions

We found a high level of success in the prepuncture ultrasound-determined insertion point. The ultrasound imaging technique can be a reliable guide to facilitate spinal anesthesia, especially in obese parturients.  相似文献   
96.
Possible benefits of vitamin K on bone health, fracture risk, markers of bone formation and resorption, cardiovascular health, and cancer risk in postmenopausal women have been investigated for over three decades; yet there is no clear evidence-based universal recommendation for its use.  相似文献   
97.
Vitamin E is known to be the most important antioxidant in the body, protecting against the effects of toxic radicals. The main idea behind the studies on vitamin E and bone metabolism stems from the concept that oxidative stress may interfere with the bone formation activity of osteoblasts which in turn can lead to osteoporosis. This mini-review, summarizes the studies on the effects of vitamin E on bone mineral density, fracture risk, bone formation, and resorption markers in perimenopausal women. Current evidence does not the support daily use of vitamin E for protection against osteoporosis and hip fracture risk in perimenopausal women. However some benefit has been shown in some observational studies. Low vitamin E (>6.2 mg/day) intake seems to be associated with an OR of 3.0 of hip fracture in current smokers. Compared with the highest quintile of alpha-tocopherol intake, the lowest quintile of intake conferred a multivariable-adjusted HR of 1.86 for hip fracture and 1.20 for any fracture. Alpha-tocopherol supplementation may alter the alpha-tocopherol/gamma-tocopherol ratio; which in turn may be associated with decreased osteoblastic activity. Interventional studies, especially randomized controlled trials (RCT), evaluating a possible causal relationship between serum vitamin E levels and BMD and hip fracture risk in perimenopausal women are needed.  相似文献   
98.
99.
100.
Mulibrey nanism is a rare autosomal-recessive disorder characterized by prenatal onset severe growth retardation and pericardial constriction associated with abnormalities of muscle, liver, brain and eye. More than 80% of previously reported patients are of Finnish origin in whom a founder mutation in the TRIM37 gene have been described. We report on a 7-year-old Turkish boy who presented with classical phenotypic features of mulibrey nanism. Mutation screening of the TRIM37 gene revealed that the proband had a homozygous two base pair deletion, c.1894_1895delGA, resulting in a frame-shift and a premature termination codon. Our proband is one of the rare examples of mulibrey nanism outside Finland and extends the mutation spectrum in this disorder.  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