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   6706篇
  免费   433篇
  国内免费   32篇
耳鼻咽喉   94篇
儿科学   156篇
妇产科学   82篇
基础医学   802篇
口腔科学   134篇
临床医学   538篇
内科学   1527篇
皮肤病学   129篇
神经病学   354篇
特种医学   179篇
外国民族医学   2篇
外科学   1061篇
综合类   128篇
一般理论   9篇
预防医学   522篇
眼科学   185篇
药学   626篇
中国医学   65篇
肿瘤学   578篇
  2023年   86篇
  2022年   231篇
  2021年   361篇
  2020年   173篇
  2019年   215篇
  2018年   274篇
  2017年   181篇
  2016年   207篇
  2015年   255篇
  2014年   327篇
  2013年   293篇
  2012年   515篇
  2011年   561篇
  2010年   356篇
  2009年   278篇
  2008年   386篇
  2007年   380篇
  2006年   358篇
  2005年   342篇
  2004年   284篇
  2003年   295篇
  2002年   230篇
  2001年   69篇
  2000年   45篇
  1999年   44篇
  1998年   56篇
  1997年   30篇
  1996年   39篇
  1995年   25篇
  1994年   23篇
  1993年   19篇
  1992年   24篇
  1991年   15篇
  1990年   14篇
  1989年   13篇
  1988年   14篇
  1987年   6篇
  1985年   14篇
  1984年   10篇
  1983年   14篇
  1982年   17篇
  1981年   9篇
  1980年   8篇
  1979年   6篇
  1978年   11篇
  1977年   5篇
  1975年   5篇
  1974年   6篇
  1973年   6篇
  1971年   5篇
排序方式: 共有7171条查询结果,搜索用时 22 毫秒
61.
62.
Thirty-eight patients with mammary gland tuberculosis were evaluated over a 5-year period presenting to the surgical unit of our institution. Unilateral involvement of the breast in a woman presenting at an average age of 29 years was the commonest observation. A lump in the breast with or without discharging sinuses was the most common clinical presentation. Ten (26%) of these patients had breast pain with or without increased breast nodularity. Axillary lymph nodal involvement was evident in 14 (36%) of our patients. Only five patients had associated pulmonary tuberculosis, the rest having an isolated involvement of the breast. Fine-needle aspiration cytology was the most reliable diagnostic modality. Medical therapy with antitubercular drugs ranging from 6 to 9 months was the mainstay of treatment. Surgical intervention was reserved for selected refractory cases.  相似文献   
63.
We present the case of a 52-year-old man, with a history of malignant melanoma, who presented with a testicular lump. Radical orchidectomy confirmed a metastatic malignant melanoma. We discuss salient features of this disease in the light of the published literature.  相似文献   
64.
Synovial fluid (SF) leptin has been shown to have an association with cartilage degeneration. Our objective was to examine the relationship between different measures of body habitus and SF leptin levels in an end‐stage knee osteoarthritis (OA) population. Sixty consecutive patients with knee OA were surveyed prior to surgery for demographic data. Body habitus was assessed with the body mass index (BMI), waist circumference (WC), and waist–hip ratio (WHR). SF and serum samples were analyzed for leptin and adiponectin using specific ELISA. Nonparametric correlations and linear regression modeling was used to identify the relationship between the measures of body habitus and SF leptin levels. Females had greater levels of leptin than males in both the serum and SF. Significant correlations were found between SF leptin levels and BMI and WC (R2 0.44 and 0.38, respectively; p < 0.05). Regression modeling showed that female gender and WC were independent predictors of a greater SF leptin level independent of age, BMI, and presence of diabetes (p < 0.05). WC may be a more accurate measure of body habitus than BMI in the relationship between the metabolic effects of adipose tissue and OA. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:329–333, 2010  相似文献   
65.
While female mice do not have the equivalent of a menopause, they do undergo reproductive senescence. Thus, to dissociate the effects of aging versus estrogen deficiency on age‐related bone loss, we sham‐operated, ovariectomized, or ovariectomized and estrogen‐replaced female C57/BL6 mice at 6 months of age and followed them to age 18 to 22 months. Lumbar spines and femurs were excised for analysis, and bone marrow hematopoietic lineage negative (lin–) cells (enriched for osteoprogenitor cells) were isolated for gene expression studies. Six‐month‐old intact control mice were euthanized to define baseline parameters. Compared with young mice, aged/sham‐operated mice had a 42% reduction in lumbar spine bone volume/total volume (BV/TV), and maintaining constant estrogen levels over life in ovariectomized/estrogen‐treated mice did not prevent age‐related trabecular bone loss at this site. By contrast, lifelong estrogen treatment of ovariectomized mice completely prevented the age‐related reduction in cortical volumetric bone mineral density (vBMD) and thickness at the tibial diaphysis present in the aged/sham‐operated mice. As compared with cells from young mice, lin– cells from aged/sham‐operated mice expressed significantly higher mRNA levels for osteoblast differentiation and proliferation marker genes. These data thus demonstrate that, in mice, age‐related loss of cortical bone in the appendicular skeleton, but not loss of trabecular bone in the spine, can be prevented by maintaining constant estrogen levels over life. The observed increase in osteoblastic differentiation and proliferation marker gene expression in progenitor bone marrow cells from aged versus young mice may represent a compensatory mechanism in response to ongoing bone loss. © 2010 American Society for Bone and Mineral Research.  相似文献   
66.
BackgroudDue to extensive fibrosis during revision surgery, adequate exposure is essential and it can be achieved with several extensile approach options, such as tibial tubercle osteotomy. Information regarding surgical exposure during revision arthroplasty is limited in developing countries, such as Pakistan, due to the lack of adequate data collection and follow-up. Therefore, the purpose of this study was to evaluate the impact of tibial tubercle osteotomy on final outcome of revision total knee arthroplasty (TKA).MethodsA total of 231 revision TKAs were performed between January 2008 and December 2017. Twenty-nine patients underwent tibial tubercle osteotomy for adequate exposure during revision surgery. Of these, 27 patients with complete follow-up were included in our study. Factors examined include age at the time of revision surgery, gender, comorbidities, arthroplasty site (right or left), body mass index (BMI), and primary indications for the tibial tubercle osteotomy during revision TKA. Functional outcome was measured by using Knee Society score (KSS) at 3 months and the final follow-up. All statistical analysis was done using SPSS version 20.0 with a p-value < 0.05 considered significant.ResultsOut of 27 patients, 6 patients (22.2%) were men and 21 patients (77.7%) were women. Right knee revision arthroplasty was performed in 15 patients (55.5%), left knee revision arthroplasty was performed in 12 patients (44.4%), and bilateral revision surgery was performed in only 1 patient (3.7%). The mean BMI was 29.2 kg/m2. We used a constrained condylar knee in 20 patients (74%), a rotating hinge knee in 5 patients (18.5%), and mobile bearing tray plus metaphyseal sleeves in 2 patients (7.4%). The KSS was 52.21 ± 4.05 preoperatively, and 79.42 ± 2.2 and 80.12 ± 1.33 at 3 months and 12 months, respectively. Radiological union was achieved in all patients at 3 months. Of 27 patients, only 1 patient (3.7%) had proximal migration of the osteotomy site at 6 months: the patient was asymptomatic and union was also achieved and, therefore, no surgical intervention was performed.ConclusionsTibial tubercle osteotomy during revision TKA can be a safe and reliable technique with superior outcomes and minimal complication rates.  相似文献   
67.
Silver nanoparticles (SNPs) can pass from the cell membrane and testicular blood barrier due to their small size, and by increasing oxidative stress they cause disorder in the male reproductive system. Kombucha is a traditional fermented drink with detoxification and potent antioxidant properties. We aimed to examine the protective effect of Kombucha against the damages due to SNPs on the testis tissue. In this experimental study, NMRI mice were randomly separated into four groups (n = 6), namely control (distilled water), SNPs (500 mg/kg), Kombucha extract (9 ml/kg) and SNPs + Kombucha, and were treated with gavage for 35 days. A significant decrease in testosterone level and total antioxidant capacity, and a significant increase in malondialdehyde concentration was observed in the SNPs group in comparison with the control group. Histological studies on the testis of mice treated with SNPs showed vacuolation, decrease in generational epithelium thickness, seminiferous tubules diameter, testis volume and the number of spermatozoa in lumen of the seminiferous tubule and increase in the volume of interstitial space while the mentioned parameters were improved in the SNPs + Kombucha group compared to the SNPs group. Kombucha reduces the adverse effects of SNPs on testis tissue and improves the function of the male reproductive system.  相似文献   
68.
69.
70.
The level of circulating endotoxin was determined in the sera from children hospitalized for treatment of diarrhea at the International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh. A significant level of endotoxin was detected in the sera from 23 (54%) of 42 children. On the other hand, in 32 normal controls, endotoxin was below the limits of detection of the assay. Antibiotic and fluid therapy markedly reduced the level of serum endotoxin and improved the general condition of most patients. Non-survivors (n = 5) had higher levels of circulating endotoxin before treatment than survivors (n = 37), suggesting a significant correlation between the serum endotoxin level before treatment and mortality. Malnutrition did not affect the serum endotoxin level in the patients with diarrhea. It was suggested that infection of Gram-negative bacteria might be involved in a significant number of patients with diarrhea in Bangladesh and that endotoxin might play a pathogenic role in those patients.  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