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   1179篇
  免费   45篇
  国内免费   4篇
耳鼻咽喉   17篇
儿科学   24篇
妇产科学   90篇
基础医学   90篇
口腔科学   95篇
临床医学   78篇
内科学   324篇
皮肤病学   8篇
神经病学   43篇
特种医学   51篇
外科学   287篇
综合类   3篇
一般理论   1篇
预防医学   17篇
眼科学   29篇
药学   46篇
中国医学   3篇
肿瘤学   22篇
  2024年   2篇
  2023年   11篇
  2022年   10篇
  2021年   24篇
  2020年   21篇
  2019年   31篇
  2018年   28篇
  2017年   29篇
  2016年   33篇
  2015年   40篇
  2014年   37篇
  2013年   69篇
  2012年   69篇
  2011年   80篇
  2010年   50篇
  2009年   30篇
  2008年   67篇
  2007年   74篇
  2006年   93篇
  2005年   72篇
  2004年   58篇
  2003年   62篇
  2002年   36篇
  2001年   17篇
  2000年   12篇
  1999年   11篇
  1998年   8篇
  1997年   9篇
  1996年   7篇
  1995年   1篇
  1992年   1篇
  1991年   5篇
  1990年   8篇
  1989年   6篇
  1988年   3篇
  1987年   3篇
  1986年   22篇
  1985年   23篇
  1984年   24篇
  1983年   23篇
  1982年   9篇
  1981年   3篇
  1980年   3篇
  1979年   1篇
  1977年   1篇
  1972年   1篇
  1925年   1篇
排序方式: 共有1228条查询结果,搜索用时 31 毫秒
1.
We report a 24-year-old woman with an intramedullary conus ependymoma associated with holocord syringohydromyelia and syringobulbia. The tumor was removed and surgery for decompression of the syringohydromyelia was not considered at the first operation. In the follow-up examinations, MRI showed significant and steady improvement of syringohydromyelia. Symptoms associated with syringohydromyelia also disappeared. The cause of syringohydromyelia accompanying intradural spinal cord tumors appears to be either direct blockade of the central canal or secondary interruption of the central canal flow by compression of the perimedullary cerebrospinal fluid flow. As removal of the mass often corrects both these likely causes of the syringohydromyelia, no additional treatment for the drainage of the hydromyelia cavity syrinx is usually necessary.  相似文献   
2.
The presence of certain defects in both cellular and humoral immunity after thermal injury has been established. Likewise, the translocation of enteric bacteria to the mesenteric lymph nodes and to distant organs has also been observed following serious thermal injury. The effects of granulocyte colony-stimulating factor (G-CSF) on bacterial translocation, the small bowel mucosa, and cecal bacterial content were investigated in a rat model of burn wound sepsis in which albino Wistar rats were scalded over 30% of their bodies, after which the lesions were infected by 1×108 colony-forming units (cfu)Pseudomonas aeruginosa. The control group was treated with 5% dextrose solution subcutaneously starting 2 days preburn, while the treatment group received 100μg/kg human G-CSF subcutaneously. On the 4th day post burn all animals were killed to examine the bowel and culture of the mesenteric lymph nodes (MLN), livers, and spleens. No significant differences were observed between the groups regarding the cecal bacterial content and small bowel; however, a difference was seen in the ratio of translocation in the MLN liver and spleen and quantitative MLN cultures. Based on these findings, G-CSF was thus found to be significantly effective in reducing bacterial translocation due to burn wound sepsis.  相似文献   
3.
The overlooked, retained double J stent   总被引:2,自引:0,他引:2  
A series of 4 patients with long overlooked, retained ureteral stents is presented to illustrate the variable, unpredictable, and at times, hazardous course of such patients. These cases are cited to re-emphasize the need for careful documentation, observation, and follow-up of patients in whom stents are placed.  相似文献   
4.
In this study the fertility and outcome of intracytoplasmic sperm injection (ICSI) using megalohead spermatozoa from the ejaculates and testicles was evaluated. Seventeen males with megalohead and pinhead sperm forms in their ejaculate were studied in 22 cycles. A high number of sperm heads without tails and abundant round spermatid forms were commonly observed. Round-headed spermatozoa were seldom accompanied by these severely abnormal spermatozoa. The majority of megalohead spermatozoa were observed to have multiple tails, were predominant in the sample, and were used for ICSI. Ejaculated megalohead spermatozoa were used for ICSI in 15 cycles, while testicular spermatozoa were used in seven cycles where there were no vital spermatozoa or spermatozoa of low vitality in the ejaculate. The same abnormal morphology was observed in the testicles as in the ejaculated spermatozoa in the same males. Mean (+/- SD) low motility 4.7 +/- 5.6% and sperm count (3.8 +/- 4.19 x 10(6)) were common findings in these severely teratozoospermic patients. A low fertilization rate (43.2%) was achieved by using megalohead sperm forms (group I, n = 17) in comparison with the control group (60.2%) which had zero normal sperm morphology according to strict criteria (group II, n = 30) (P <0.01). Furthermore, a low pregnancy rate (9.1%) was obtained in the megalohead sperm group in comparison with the control group (40%) (P <0.05). Low fertilization and pregnancy rates may be due to a high incidence of chromosomal abnormalities from severely defective spermatozoa in the ejaculate. Couples should be counselled and warned about possible low fertilization and pregnancy rates with ICSI when only pinhead and megalohead forms with a high number of sperm heads without tails are present in the ejaculate.  相似文献   
5.
The pathogenesis of adult polycystic kidney disease (PCKD) remains an enigma. In an attempt to find a defect that might explain the cyst formation, an ultrastructural study was performed on seven fresh bilateral nephrectomies of seven patients suffering from adult PCKD. Marked electron microscopic changes of the tubular basement membranes were detected, including thickening, splitting, fraying, and multilayering of the basement membranes. By contrast, glomerular basement membranes lacked these alterations. The kidneys from two control groups (five donor kidneys harvested for transplantation; 10 patients who suffered from end stage renal disease) showed none of the lesions detected in the polycystic kidneys. The lesions of the tubular basement membrane, the principal support of tubular wall, may be the primary phenotypic expression and cause of the inherited defect.  相似文献   
6.
Abstract An hepatomesenteric trunk, formed by the common hepatic and superior mesenteric arteries, was found in a 50-year-old male cadaver. The left gastric and splenic arteries arose as a common trunk, the gastrosplenic trunk, from the abdominal aorta; no typical celiac trunk was present. In addition, the hepatomesenteric trunk passed posterior to the portal vein. A knowledge of variations of the common hepatic artery may be important in pancreaticoduodenectomy, as well as during hepatic artery infusion chemotherapy.  相似文献   
7.
Although when UV-irradiated seven most toxic strains of Bacillus sphaericus lost their viabilities between 2.5-4.5 min, their larvicidal activity was protected for longer periods. Benzaldehyde, cinnamaldehyde, salicylaldehyde, methylene blue and yeast extract showed good protective effect for spore viability and larvicidal activity from UV inactivation in B. sphaericus. This protective effect has also been confirmed by SDS-PAGE analyses whereby the 42 kDa and 51 kDa toxic proteins bands did not disappear following UV treatment.  相似文献   
8.
Purpose

Cardiovascular disease is one of the major causes of mortality in anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Metabolic syndrome (MetS) is associated with increased cardiovascular risk in the normal population. However, MetS in AAV has not been adequately investigated. We aimed to determine MetS prevalence and associated factors in AAV patients.

Methods

Thirty-seven AAV patients and 42 healthy controls were enrolled. MetS was determined by International Diabetes Federation (IDF) and National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATPIII) criteria. The relationship between clinical features of AAV and MetS was also investigated.

Results

MetS was significantly higher in AAV patients than controls by NCEP-ATPIII (51.4% vs. 26.2%, p 0.022) and IDF (62.2% vs. 35.7%, p 0.020). When AAV patients with MetS were compared to those without, there were significant differences in age, CRP, GFR and NT-pro-BNP. Age [58 (13) vs. 50 (8) years p: 0.028], CRP [4.0 (3.6) vs. 3.2 (1.0) mg/l, p 0.021] and NT-pro-BNP [173.5 (343.7) vs. 106.0 (103.0) pg/ml, p 0.013] were significantly higher in AAV patients with MetS than those without; GFR was significantly lower [38 (46) vs. 83 (51) ml/min/1.73 m2, p 0.004]. ROC curve analysis showed NT-pro-BNP?>?58.0 ng/ml predicted MetS with 87.1% sensitivity and 46.7% specificity (Area under curve: 0.71, CI 0.536–0.902, p 0.041). Multivariate analysis revealed age [OR (95% CI): 1.180 (1.010–1.370), p 0.039] and NT-pro-BNP?>?58 pg/ml [OR (95% CI): 5.5 (1.02–30.1) p 0.047] were independent predictors of MetS in AAV patients.

Conclusion

MetS is significantly higher in AAV patients than controls and is associated with age and NT-pro-BNP. Screening and treating MetS may improve prognosis in AAV patients.

  相似文献   
9.
Neurosurgical Review - “Benign” metastatic leiomyomas (BML) are indolently growing metastatic tumors which mostly associate with uterine leiomyomas in women in reproductive ages. The...  相似文献   
10.
AIMS: Germline mutated RET proto-oncogene, causing multiple endocrine neoplasia (MEN)-2a syndrome is the indication for prophylactic total thyroidectomy. Literature regarding the risk and the extent of early surgical intervention is scarce and the optimum age for surgery is still controversial. To optimize management in these young children we evaluate our experience and results. PATIENTS AND METHODS: From 1990 to 2001 preventive total thyroidectomy was performed in 13 MEN-2a gene carriers (4 boys and 9 girls; median age 7 (4-14) years). Preoperative assessment, surgical procedure, pathological examination, postoperative complications and treatment results were studied. RESULTS:Surgery existed of a total thyroidectomy alone (n=3) in children with normal basal calcitonin and in combination with tracheo-esophageal exploration (n=6) or central compartment dissection (n=4) in case of abnormal calcitonin levels. Eight children presented with medullary thyroid cancer (MTC), three (median: 5 (4-12) years) with microscopic MTC and five (median 6 (4-14) years) with frank invasive MTC. Four of these five patients were younger than 6 years. Except for long-lasting hypoparathyroidism in one patient there were no complications. At a median follow-up of 6.5 years all patients are disease free. CONCLUSION: MTC in RET mutated MEN-2a gene carriers in childhood are found at the age of 4 years. Therefore, DNA testing should be done preferably before that age. Preventive surgery can be performed safely at that age and may be limited to total thyroidectomy when baseline calcitonin levels are normal.  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