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   29015篇
  免费   2085篇
  国内免费   134篇
耳鼻咽喉   291篇
儿科学   916篇
妇产科学   617篇
基础医学   4420篇
口腔科学   2601篇
临床医学   2371篇
内科学   5725篇
皮肤病学   642篇
神经病学   2135篇
特种医学   749篇
外国民族医学   1篇
外科学   3286篇
综合类   388篇
一般理论   7篇
预防医学   3255篇
眼科学   385篇
药学   2057篇
中国医学   282篇
肿瘤学   1106篇
  2023年   270篇
  2022年   464篇
  2021年   1074篇
  2020年   747篇
  2019年   929篇
  2018年   1101篇
  2017年   835篇
  2016年   846篇
  2015年   1000篇
  2014年   1287篇
  2013年   1549篇
  2012年   2252篇
  2011年   2458篇
  2010年   1347篇
  2009年   1040篇
  2008年   1624篇
  2007年   1548篇
  2006年   1424篇
  2005年   1146篇
  2004年   1015篇
  2003年   897篇
  2002年   805篇
  2001年   562篇
  2000年   613篇
  1999年   504篇
  1998年   274篇
  1997年   201篇
  1996年   214篇
  1995年   171篇
  1994年   163篇
  1993年   112篇
  1992年   229篇
  1991年   226篇
  1990年   208篇
  1989年   218篇
  1988年   205篇
  1987年   160篇
  1986年   146篇
  1985年   145篇
  1984年   113篇
  1983年   89篇
  1982年   60篇
  1981年   58篇
  1979年   88篇
  1978年   81篇
  1975年   63篇
  1974年   62篇
  1973年   63篇
  1970年   60篇
  1967年   54篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
991.
Tuberculosis (TB) is a current public health problem, remaining the most common worldwide cause of mortality from infectious disease. Recent studies indicate that genitourinary TB is the third most common form of extra-pulmonary disease. The diagnosis of renal TB can be hypothesized in a non-specific bacterial cystitis associated with a therapeutic failure or a urinalysis with a persistent leukocyturia in the absence of bacteriuria. We report on the case of a 33-year-old man who presented on admission end stage renal disease (ESRD) secondary to renal TB and a past history of pulmonary TB with important radiologic findings. The diagnosis was based on clinical findings despite all cultures being negative. Empiric treatment with tuberculostatic drugs was started and the patient became stable. He was discharged with no symptom, but without renal function recovery. He is on maintenance hemodialysis three times a week. TB is an important cause of kidney disease and can lead to irreversible renal function loss.  相似文献   
992.
993.
994.
The aim of the present study was to analyze the influence of a ballroom dancing program on the functional autonomy and physical balance of institutionalized elderly individuals. The study enrolled 75 sedentary elderly subjects from long-term institutions who were randomly divided into a ballroom dance program group (EG; n=39) and a control group (CG; n=36). The protocol of the Latin American Group for Maturity (GDLAM) was used to evaluate functional autonomy. Physical balance was analyzed using a stabilometer and posture meter platforms. The level of significance in statistical tests was set at p<0.05. Regarding the physical balance evaluation, only the members of the EG achieved a significant reduction in weight (Δ=-0.98 kg) following the experiment, both in the intragroup (p=0.002) and in the intergroup analysis (p=0.012). In the evaluation of functional autonomy, only the EG showed a significant reduction in the execution time of all the tests and in the GDLAM index: GI (Δ=-6.99), both in the intragroup (p<0.001) and in the intergroup analysis (p=0.011). Thus, it can be inferred that sedentary elderly individuals who are residents of long-term institutions can improve their functional autonomy and balance with a ballroom dance program.  相似文献   
995.
Abstract. In October of 2008, an outbreak of trichinellosis occurred in northern California that sickened 30 of 38 attendees of an event at which meat from a black bear was served. Morphologic and molecular testing of muscle from the leftover portion of bear meat revealed that the bear was infected with Trichinella murrelli, a sylvatic species of Trichinella found in temperate North America. Clinical records revealed a high attack rate for this outbreak: 78% for persons consuming any bear meat and 100% for persons consuming raw or undercooked bear meat. To our knowledge, this report is the first published report of a human trichinellosis outbreak in the United States attributed to T. murrelli, and it is the second such outbreak reported worldwide.  相似文献   
996.
J Oral Pathol Med (2012) 41 : 559–567 Objective: Our aim was to evaluate the expression of several molecules that regulate growth, the cell cycle and signalling pathways including EGFR, p53, p16 and p27 in oral squamous cell carcinomas (OSCC). We examined their utility as prognostic markers by relating to clinicopathological characteristics and the clinical outcome. Patients and methods: Using tissue microarray technology, we analysed 67 primary OSCC and examined immunohistochemical expression of EGFR, p53, p16 and p27. Multivariate analysis was conducted to examine their role in survival. Results: Many of the markers were highly expressed in these cancers. Membranous EGFR expression in 95.2%, both membrane and cytoplasm expression in 35%, p53 expression in 61.6%, p27 expression in 89.5% and p16 expression in 27.9% of cases. In the multivariate analysis, independent prognostic influence of a lower overall survival was determined only for advanced tumour stage (P < 0.001), p53 overexpression (P = 0.004), EGFR cytoplasm and membrane co‐expression location (P = 0.002) and p16 reduced expression (P = 0.002). When considering a subgroup of early stage tumours, p53 overexpression (P = 0.028) and combined membranous and cytoplasm EGFR co‐expression (P = 0.039) were indicators of a lower overall survival. For disease‐free survival, in addition to these three factors, the histological grade (P = 0.011) showed independent prognostic values. Conclusion: The independent value of EGFR subcellular location (cytoplasm and membrane) and p53 overexpression in overall survival even in early stages of OSCC suggests that these markers may serve as reliable biological markers to identify high‐risk subgroups and to guide therapy.  相似文献   
997.
J Oral Pathol Med (2012) 41 : 630–636 Background: Several cell types are associated with the development of cystic and tumoral odontogenic lesions. Among inflammatory cells, mast cells can be associated with their pathogenesis. The aim of this study was to analyze mast cells in periapical cysts, dentigerous cysts, and keratocystic odontogenic tumors. Methods: Tissue sections were submitted to toluidine blue staining and immunohistochemistry with antibody anti‐tryptase (clone G3). Mast cells were quantitated using Image‐Pro Plus software to obtain the mean number of mast cells in three regions: epithelial, superficial portion of the fibrous wall and deep portion of the fibrous wall from 20 periapical cysts, 20 dentigerous cysts (six non‐inflamed and 14 inflamed) and 20 keratocystic odontogenic tumors (four non‐inflamed and 16 inflamed). Results: The mean number of mast cells detected per lesion by immunohistochemistry (4.1) was higher than by histochemistry (1.5) (P < 0.0001). Inflamed dentigerous cysts and keratocystic odontogenic tumors showed a higher mean number of mast cells than non‐inflamed lesions in all regions. The deep region from all cysts showed the highest mean number of degranulated mast cells, except for non‐inflamed keratocystic odontogenic tumors analyzed by immunohistochemistry. Conclusions: Immunohistochemical staining detected higher number of mast cells than histochemistry. The higher number of mast cells observed in inflamed lesions could indicate the participation of these cells in the inflammatory response in odontogenic lesions. The prevalence of degranulated mast cells in the deep region suggests intense activity of these cells, possibly related to growth of cystic lesions.  相似文献   
998.
International Journal of Paediatric Dentistry 2012; 22: 286–291 Background. In dentistry, clinical practice is directed towards attitudes that promote oral health and the paediatricians occupy a privileged position in this process. Aim. To assess the knowledge and attitudes of paediatricians in relation to the oral health of their patients. Design. A cross‐sectional study was carried out at the Institute of Integrative Medicine Professor Fernando Figueira, Recife, Brazil. A total of 182 paediatricians participated by filling out a questionnaire. Results. A total of 63.9% believed the first visit to the dentist should occur before the child completes 1 year of life. Moreover, 67.8% considered their knowledge on oral health to be insufficient. Approximately 78% of the paediatricians diagnosed caries through an analysis of cavities. Only 29.9% always recommended fluoride dentifrice. The term ‘fluorosis’ was unknown by 48.3% of the respondents. Concerning pacifiers, 32.6% did not allow it and 66.9% did not either recommend it or restrict it. A total of 83.4% classified the oral health content in their medical education as either nonexistent or deficient; this figure remained high (72.4%) in relation to residency. Conclusions. It is important to develop oral health information programmes to paediatricians. Information on oral health should be included in medical curricula and residency.  相似文献   
999.
Gingival overgrowth (GO) may be related to the frequent use of certain medications, such as cyclosporin, phenytoin (PHT), and nifedipine, and is therefore denominated drug-induced GO. This article reports a case of a patient who with chronic periodontitis made use of PHT and presented generalized GO. A 30-year-old man with GO was referred to the clinic of the Universidade Estadual Paulista, Brazil. The complaint was poor aesthetics because of the GO. The patient had a medical history of a controlled epileptic state, and PHT was administered as an anticonvulsant medication. The clinical examination showed generalized edematous gingival tissues and presence of bacterial plaque and calculus on the surfaces of the teeth. The diagnosis was GO associated with PHT because no other risk factors were identified. Treatment consisted of meticulous oral hygiene instruction, scaling, root surface instrumentation, prophylaxis, and daily chlorhexidine mouth rinses. After this stage, periodontal surgery was performed, and histopathologic evaluation was made. The patient has been under control for 3 years after the periodontal surgery, and up to the present time, there has been no recurrence. It can be concluded that PHT associated with the presence of irritants favored gingival growth and that the association of nonsurgical and surgical periodontal therapies was effective in the treatment of GO. Besides, motivating the patient to maintain oral hygiene is a prerequisite for the maintenance of periodontal health.  相似文献   
1000.
To prevent rejection of kidney transplants, patients must be kept in immunosuppressive therapy for a long time, which includes the use of drugs such as cyclosporine, azathioprine, cyclophosphamide, and prednisone. The action of these drugs reduces the general immune response of transplant patients and thus increases their susceptibility to infections. Moreover, these drugs increase the potential of developing lesions. Therefore, oral hygiene in kidney transplant recipients contributes to maintenance of the transplanted organ and its function. Thus, an investigation of oral lesions could be counted as a notable work. The aim of this study was to investigate oral lesions in a group of 21 kidney transplant patients under immunosuppressive therapy attended during a 1-year period in the Nephrology Department of the Federal University of Sergipe, Brazil. Data related to sex, age, etiology of renal disease, types of renal transplant, time elapsed after transplantation, immunosuppressive treatment, use of concomitant agents, and presence of oral lesions were obtained. All patients received a kidney transplant from a living donor, and the mean posttransplantation follow-up time was 31.6 months; 71.5% used triple immunosuppressive therapy with cyclosporine A, azathioprine, and prednisone. Ten patients were also treated with calcium-channel blockers. Of the 21 transplant patients, 17 (81%) presented oral lesions. Gingival overgrowth was the most common alteration, followed by candidiasis and superficial ulcers. One case of spindle cell carcinoma of the lower lip was observed. Oral cavity can harbor a variety of manifestations related to renal transplantation under immunosuppressive therapy.  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