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   1024篇
  免费   40篇
  国内免费   8篇
耳鼻咽喉   25篇
儿科学   42篇
妇产科学   88篇
基础医学   58篇
口腔科学   45篇
临床医学   83篇
内科学   182篇
皮肤病学   10篇
神经病学   86篇
特种医学   21篇
外科学   273篇
综合类   5篇
预防医学   29篇
眼科学   44篇
药学   51篇
中国医学   2篇
肿瘤学   28篇
  2023年   9篇
  2022年   20篇
  2021年   25篇
  2020年   16篇
  2019年   28篇
  2018年   36篇
  2017年   22篇
  2016年   50篇
  2015年   43篇
  2014年   30篇
  2013年   49篇
  2012年   69篇
  2011年   76篇
  2010年   55篇
  2009年   40篇
  2008年   85篇
  2007年   83篇
  2006年   63篇
  2005年   83篇
  2004年   53篇
  2003年   40篇
  2002年   37篇
  2001年   15篇
  2000年   15篇
  1999年   6篇
  1998年   1篇
  1997年   5篇
  1996年   3篇
  1995年   1篇
  1994年   2篇
  1992年   4篇
  1991年   4篇
  1989年   1篇
  1985年   1篇
  1983年   1篇
  1976年   1篇
排序方式: 共有1072条查询结果,搜索用时 15 毫秒
111.
Ischemia-modified albumin (IMA) is a sensitive marker of myocardial ischemia, skeletal muscle ischemia, pulmonary embolism, and stroke. However, there are no studies showing whether IMA increases in mesenteric ischemia. The aim of this study was to determine whether IMA was elevated in acute mesenteric ischemia. This case-controlled study was performed in an emergency department of a university hospital. The measurement of IMA levels in patient plasma yielded means of 0.264 +/- 0.057 absorbance units (ABSU) in the thromboembolic occlusion of the superior mesenteric artery (SMA) group and 0.163 +/- 0.025 ABSU in the control group. When plasma IMA levels in the thromboembolic occlusion SMA group were compared with those in the control group, statistically significant increases in IMA were observed in the occlusion group (P = .003). Findings indicating that IMA may have a place in the diagnosis of acute mesenteric embolism were obtained in this preliminary study. Further prospective studies are needed to see if IMA is clinically useful in the early detection of thromboembolic occlusion of the SMA.  相似文献   
112.
OBJECTIVE: Alpha-blockers are the most widely used agents to treat lower urinary tract symptoms in males, and switching between alpha-blockers is a frequent management option when the desired effect could not be obtained. There is no data in the literature that reveal the outcome of treatments with different alpha-blockers within the same patient. We sought the answer to this question in a setting where the same individuals were treated with two different agents during different time frames. MATERIALS AND METHODS: Forty males with benign prostatic hyperplasia (BPH) applying to the Department of Urology with lower urinary tract symptoms (LUTS) were enrolled in the study consecutively. Patients were evaluated with detailed medical history, IPSS forms, digital rectal examination (DRE), urinary ultrasound, PSA, and uroflowmetry. The subjects received terazosin 5 mg daily for 3 months, and controlled release form of alfuzosin 10 mg daily for another 3 months, leaving a 1-month clearance period in between. The above-mentioned detailed evaluations were carried out before and after each alpha-blocker regimen. RESULTS: Mean age and PSA level was 63.3 +/- 1.6 years (45-80), and 2.1 +/- 0.4 ng/ml (0.16-6.3 ng/ml). IPSS and Q (max) values before treatment with terazosin and alfuzosin were similar. Improvements in IPSS and Q (max) values after treatments with both terazosin and alfuzosin were significant. There was no statistically significant difference between the drugs in terms of percent improvements in IPSS and Q (max) with alpha-blocker treatment. No untoward effect except for transient dizziness in one case with terazosin treatment was encountered. CONCLUSION: Different alpha-blockers, which are used during different time frames in the same individuals, provide similar efficiency outcome. When the desired effect in the treatment for BPH could not be obtained with one alpha-blocker, there may not be any benefit in switching to another one.  相似文献   
113.
PURPOSE: To evaluate the effectiveness and safety of pneumatic lithotripsy by using a ureteroscope to treat bladder stones in children. PATIENTS AND METHODS: Twenty-seven boys presenting with bladder stones underwent transurethral cystolithotripsy. The indication for transurethral cystolithotripsy was stone size 相似文献   
114.
115.
A 75-year-old woman came to our emergency clinic complaining of abdominal pain. Acute cholecystitis was diagnosed, and parenteral antibiotic therapy was initiated. Because of palpitation, she had a consultation with the cardiology clinic. Echocardiography showed a 2.7 x 2.2 cm mobile thrombus attached to the apex of the right ventricle. Since no thromboembolic complications were present, we decided to begin administering heparin and oral anticoagulant. After the administration of unfractionated heparin for 48 hours, the patient was shifted to low-molecular weight heparin because it is easier to use and requires no follow-up. The patient received low-molecular weight heparin in addition to sodium warfarin for 5 days. Administration of heparin was then stopped and treatment was continued with sodium warfarin. In the series of weekly echocardiography evaluations, a gradual reduction was noted in the apical mass, which was initially considered to be a thrombus, and 3 weeks later evaluation revealed that the thrombus in the right ventricle had disappeared completely. No thromboembolic complications were observed during the follow-up period.  相似文献   
116.
Sexual potency declines with age, as does the efficiency of erection. Many studies show that different patterns of erectile dysfunction (ED), varying from occasional inability to obtain a full erection, impairment throughout intercourse and total absence of erectile response, might not be triggered by psychological factors only. Recent research indicates that ED relies on organic causes, and has challenged the development of new therapies. One therapeutic approach in patients who have testosterone deficiency is based on androgen therapy. Thus, we reviewed data on testosterone-induced effects relative to erectile function, summarizing the results from studies reported in 1991-2006 on testosterone therapy in patients with ED and hypogonadism, with a special focus on men not responding to phosphodiesterase-5 (PDE-5) inhibitors. We searched several computerized databases parallel with printed bibliographic references. Many studies have established animal models, which confirm that testosterone is important in modulating the central and peripheral regulation of ED. Testosterone deprivation has a strong negative impact on the structure of penile tissues and erectile nerves, which can be prevented by androgen administration. Combined therapy regimens with PDE-5 inhibitors and testosterone might improve ED in patients with hypogonadism of different causes. Thus, androgen treatment in hypogonadic patients, including those unresponsive to PDE-5 inhibitors, often results in an improvement of ED. Testosterone therapy is safe and convenient, while rapidly correcting low testosterone levels.  相似文献   
117.
Background: Recent studies showed that vitamin D deficiency may lead to dysfunctional changes in the brain and may be associated with neuropsychiatric diseases.

Aims: The present study aims to investigate vitamin D, calcium, phosphorus and alkaline phosphatase levels in children and adolescents diagnosed with obsessive-compulsive disorder (OCD) and compared them to healthy controls. Additionally, the correlation of OCD symptom severity with serum vitamin D level will be analyzed.

Methods: A semi-structured interview form (K-SADS-PL) was used to diagnose OCD and other comorbidities in accordance with DSM-IV criteria. In addition, all participants were assessed with clinical interviews based on DSM-5 OCD diagnostic criteria. Children's Yale Brown Obsession Compulsion Scale (CY-BOCS) and Children’s Depression Inventory were used in the clinical evaluation.

Results: Vitamin D levels were lower in patients diagnosed with OCD (15.88?±?6.96?ng/mL) when compared to healthy controls (18.21?±?13.24?ng/mL), but the difference was not statistically significant (p?=?.234). Serum calcium, serum phosphate and serum alkaline phosphatase levels were not different between the groups. A negative correlation was found between serum 25OH-D3 levels and obsession scale scores in CY-BOCS.

Conclusions: To our knowledge this is the first study that evaluated vitamin D levels in OCD patients without comorbidity. The vitamin D levels of newly diagnosed OCD cases were lower but not statistically different than healthy controls. Furthermore, the study does also not support the presence of a significant association between serum vitamin D levels and OCD.  相似文献   
118.
The role of esophageal dilation in patients with esophageal eosinophilia with dysphagia remains unknown. The practice of dilation is currently based on center preferences and expert opinion. The aim of this study is to determine if, and to what extent, dysphagia improves in response to initial esophageal dilation followed by standard medical therapies. We conducted a randomized, blinded, controlled trial evaluating adult patients with dysphagia and newly diagnosed esophageal eosinophilia from 2008 to 2013. Patients were randomized to dilation or no dilation at time of endoscopy and blinded to dilation status. Endoscopic features were graded as major and minor. Subsequent to randomization and endoscopy, all patients received fluticasone and dexlansoprazole for 2 months. The primary study outcome was reduction in overall dysphagia score, assessed at 30 and 60 days post‐intervention. Patients with severe strictures (less than 7‐mm esophageal diameter) were excluded from the study. Thirty‐one patients were randomized and completed the protocol: 17 randomized to dilation and 14 to no dilation. Both groups were similar with regard to gender, age, eosinophil density, endoscopic score, and baseline dysphagia score. The population exhibited moderate to severe dysphagia and moderate esophageal stricturing at baseline. Overall, there was a significant (P < 0.001) but similar reduction in mean dysphagia score at 30 and 60 days post‐randomization compared with baseline in both groups. No significant difference in dysphagia scores between treatment groups after 30 (P = 0.93) or 60 (P = 0.21) days post‐intervention was observed. Esophageal dilation did not result in additional improvement in dysphagia score compared with treatment with proton pump inhibitor and fluticasone alone. In patients with symptomatic esophageal eosinophilia without severe stricture, dilation does not appear to be a necessary initial treatment strategy.  相似文献   
119.
Does pinealectomy affect the recovery rate after spinal cord injury?   总被引:1,自引:0,他引:1  
Previous reports documented demonstrated that melatonin, a free radical scavenger, is important in protecting against oxidative stress-induced tissue damage after spinal cord injury (SCI). This study was undertaken to investigate the effects of pinealectomy (PX) and administration of exogenous melatonin after SCI in rats. These animals were randomized into six groups, each having 12 rats. Group 1 underwent laminectomy alone. Group 2 underwent laminectomy followed by SCI and received no medication. Group 3 underwent laminectomy followed by SCI and received melatonin. Group 4 underwent PX and laminectomy alone. Group 5 underwent PX and laminectomy followed by SCI and received no medication. Group 6 underwent PX and laminectomy followed by SCI and received melatonin. Melatonin (100 mg/kg) was given intraperitoneally immediately after trauma to the rats in the groups 3 and 6. PX caused a significant increase in the malondialdehyde (MDA), nitrite oxide (NO), glutathione (GSH), xanthine oxidase (XO) levels and decrease in GSH levels as compared with the control group. Trauma to the spinal cord results in significantly higher oxidative stress. Melatonin administration significantly reduced MDA, XO and NO levels, and increased GSH levels in the spinal cord after trauma. Exogenous melatonin treatment after trauma attenuated tissue lesion area and accelerated motor recovery rate. These findings suggest that reduction in endogenous melatonin after PX makes the rats more vulnerable to trauma and exogenous melatonin administration has an important neuroprotective effect on the level of the spinal cord.  相似文献   
120.
The relationship between erectile dysfunction (ED) and chronic renal failure (CRF) has been reported in several studies. This study aimed to investigate whether the chronic use of sildenafil could enhance the erectile capacity in CRF-induced rats. In addition, we assessed the effect of that treatment on certain molecules, which have been suggested to play crucial roles in erectile physiology and CRF-related ED as well. Three groups of animals were utilized: (1) age-matched control rats, (2) CRF-induced rats, (3) CRF-induced rats treated with chronic administration of sildenafil (5 mg kg−1 p.o. for 6 weeks [treatment started after 6 weeks of CRF induction]). At 3 months, all animals underwent cavernosal nerve stimulation (CNS) to assess erectile function. Penile tissue advanced glycation end products (AGE''s)/5-hydroxymethyl-2-furaldehyde, malondialdehyde (MDA), cGMP (ELISA), inducible nitric oxide synthase (iNOS) and neuronal NOS (nNOS) (Western blot) analyses were performed in all rat groups. CRF-induced rats had a significant decrease in erectile function when compared to control rats (P < 0.05). The increase in both intracavernosal pressure (ICP) and area under the curve of CRF-induced rats treated with sildenafil (Group 3) was greater than CRF-induced rats (Group 2). Additionally, sildenafil treatment decreased AGE, MDA and iNOS levels, while it preserved nNOS and cGMP contents in CRF-induced penile tissue. Decreased AGE, MDA, iNOS and increased nNOS, cGMP levels at the sildenafil-treated group increased both ICP and Total ICP to CNS, which led to improve erectile function in CRF-induced rats. The results of the present study revealed the therapeutic effect of chronic sildenafil administration on erectile function in CRF-induced rats.  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