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   1156篇
  免费   63篇
  国内免费   2篇
耳鼻咽喉   73篇
儿科学   18篇
妇产科学   61篇
基础医学   143篇
口腔科学   38篇
临床医学   135篇
内科学   189篇
皮肤病学   23篇
神经病学   96篇
特种医学   18篇
外科学   176篇
一般理论   3篇
预防医学   33篇
眼科学   120篇
药学   28篇
肿瘤学   67篇
  2023年   9篇
  2022年   5篇
  2021年   7篇
  2020年   11篇
  2019年   7篇
  2018年   16篇
  2017年   16篇
  2016年   21篇
  2015年   15篇
  2014年   34篇
  2013年   24篇
  2012年   48篇
  2011年   45篇
  2010年   37篇
  2009年   34篇
  2008年   67篇
  2007年   82篇
  2006年   75篇
  2005年   87篇
  2004年   81篇
  2003年   73篇
  2002年   93篇
  2001年   22篇
  2000年   22篇
  1999年   18篇
  1998年   16篇
  1997年   16篇
  1996年   16篇
  1995年   12篇
  1994年   5篇
  1993年   9篇
  1992年   13篇
  1991年   22篇
  1990年   11篇
  1989年   15篇
  1988年   21篇
  1987年   21篇
  1986年   13篇
  1985年   15篇
  1984年   13篇
  1983年   10篇
  1982年   6篇
  1981年   7篇
  1980年   4篇
  1979年   10篇
  1977年   3篇
  1975年   3篇
  1973年   2篇
  1972年   2篇
  1971年   2篇
排序方式: 共有1221条查询结果,搜索用时 0 毫秒
61.
BACKGROUND AND OBJECTIVE: To report the outcome of combined verteporfin photodynamic therapy (PDT) and intravitreal triamcinolone acetonide (IVTA) for the treatment of choroidal neovascularization (CNV) with serous pigment epithelium detachment (PED) due to age-related macular degeneration (AMD). PATIENTS AND METHODS: The files of all consecutive patients with CNV and serous PED who received PDT and IVTA either primarily (primary treatment group) or following previous unsuccessful PDT (secondary treatment group) were reviewed for visual and angiographic results. RESULTS: Ten patients (11 eyes) were included. Mean number of PDT sessions was 3.18; 8 eyes received one IVTA injection and 3 eyes received two IVTA injections. Thirty-six percent of patients retained their initial visual acuity after a mean follow-up of 15.3 months. Loss of 3 or more Snellen lines was noted in 2 of 3 eyes in the primary treatment group and 5 of 8 eyes in the secondary treatment group. Increased intraocular pressure developed in 3 patients and was controlled by topical medications. CONCLUSIONS: Although combined PDT and IVTA may be considered for CNV with serous PED in patients with poor prognosis with PDT alone, the regimen as administered in this small series was not beneficial. Further studies are required to determine whether alternate sequences, timing, or doses would yield a better outcome.  相似文献   
62.
Burkitt's-lymphoma (BL) lines which have maintained in vitro the tumor-cell phenotype (group-1 BLs) are poor antigen- presenting cells (APC), in spite of a relatively high surface expression of MHC class II. In order to investigate the mechanism of this deficiency, we have compared group-1 BL lines, their sub-lines which have progressed in vitro towards an LCL-like phenotype (group-III BL), and EBV-transformed lymphoblastoid cell lines (LCLs), for their ability to bind and process tetanus toxoid (TT). The uptake and internalization of 125I-labelled TT was equivalent in the 3 cell types. Only LCLs and group-III BL lines were able to process the IT,as shown by the identification of discrete proteolytic products after separation of whole-cell extracts in tricine-SDS-polyacrylamide gels, and by the recovery of TCA-soluble radioactivity in the culture supernatant. Processing of TT was induced by expression of the EBV- encoded membrane protein LMPI in transfected group-I BLs. The present findings suggest that the inability of group-I BLs to act as APC is due to their failure to process exogenous antigens. This function appears to be related to phenotypic properties that can be modulated by the expression of LMPI.  相似文献   
63.
64.
OBJECTIVE: To evaluate the tonsils as a source of halitosis and to assess the efficacy of laser CO(2) cryptolysis for the treatment of oral bad breath caused by chronic fetid tonsillitis. METHODS: Fifty-three patients with halitosis originating from chronic fetid tonsillitis, who completed laser cryptolysis were enrolled in the study. The origin of halitosis was demonstrated by Finkelstein's tonsil smelling test, which included massaging the tonsils and smelling the squeezed discharge. All patients were treated by laser cryptolysis, an office procedure done under topical anesthesia. Subjective and objective postoperative assessment was based on self-and-family report and clinical assessment. Patients were reexamined 4 to 6 weeks post-treatment, and when the need for further laser treatment was determined. RESULTS: Complete elimination of halitosis required one session in 28 patients (52.8%), 2 sessions in 18 patients (34%), and 3 sessions in 5 patients (9.4%). Follow-up period ranged from 3 to 36 months (mean, 20.8 +/- 8.5 months). No adverse effects or complications were encountered. CONCLUSIONS: After excluding dental or periodontal, sinonasal, oral, pulmonary, or gastroenterological diseases as the origin of halitosis, chronic fetid tonsillitis remains a common cause of halitosis. Patients suffering from halitosis should be treated relying on their examination including Finkelstein's tonsil smelling test. Laser CO(2) cryptolysis is an effective, safe, and well-tolerated procedure for the treatment of halitosis.  相似文献   
65.
66.
A method for a combined air and isotope ventriculography is described. Twenty-nine infants with suspected hydrocephalus were studied. The merit of the combined study is the possibility of obtaining both anatomical and functional information. A very small amount of radioactivity—15 μc—was found to give satisfactory results. Patterns of cerebrospinal fluid flow in communicating and non-communicating hydrocephalus and in cases of porencephalic cyst and complete obstruction of the lateral ventricles are described.  相似文献   
67.
Germline mutations in DNA mismatch repair (DNA-MMR) genes, mainly hMlh1 and hMsh2, underlie Hereditary Non-Polyposis Colorectal Cancer (HNPCC). Germline hMSH6 gene mutations have been reported in a small subset of HNPCC families. In the present study, ethnically diverse individuals with HNPCC and HNPCC-like features were genotyped for hMsh6 germline mutations using exon-specific PCR, DGGE, and DNA sequencing. The study encompassed 92 individuals representing 88 unrelated families who were previously analyzed for Msh2 and Mlh1 mutations: Jewish Ashkenazim (n = 44), non-Ashkenazim (n = 27), Israeli Moslem-Arab (n = 15), Druze (n=3), and Cypriot non-Jews (n = 3). Of the study population, 71 had colon cancer (CRC), mean age at diagnosis was 50.9±13.2 years (range16–73 years), 5 had endometrial cancer (two with concurrent CRC), (mean 43.6±3.26 years, range 38–45 years), and unaffected individuals (n = 18) were first degree relatives within HNPCC families and were genotyped at a mean age of 48.3±11.7 years (range 30–69 years). Of the 92 individuals analyzed, none showed a truncating hMsh6 mutation, and 6 (6.6%) harbored one of three germline missense mutations: a previously reported one (V878A), and two novel mutations (V509A, S227I). The pathogenic significance of these three missense mutations is yet unclear. In addition, 5 polymorphisms were detected, 2 of which were novel. We conclude that the rate of pathogenic hMsh6 mutations in HNPCC families of Jewish and Mediterranean origin is low, and that mutations in other genes probably account for the phenotype in these families.  相似文献   
68.
The objective was to examine gender differences and similarities in health, function, familial and non-familial social networks; longitudinal resilience in those factors; and their association with risk of mortality in Israeli men and women aged 75-94. We used the Cross-Sectional and Longitudinal Aging Study (CALAS), a stratified random sample of 960 Israeli Jews aged 75-94, drawn on January 1, 1989 from National Population Registry, stratified by gender, age (75-79, 80-84, 85-89, 90-94), and place of birth (Europe/America, Middle East/North Africa, Israel), interviewed twice (Wave 1, 1989-1992; Wave 2, 1993-1995); Wave 1 values and longitudinal resilience predicted the 1999 mortality risk for those alive at both waves. Gender differences and similarities were found at Wave 1 in longitudinal resilience and in risk factors for mortality, partially supporting a gender paradox. Men were more physically active, had better cognition, gave more help to children, relied less on paid caretakers, and attended synagogue more than women, factors associated with better health and functioning. Women had poorer health and functional status and more help from children. More physical activity, synagogue attendance, and resilience in activities of daily living (ADL) were associated with lower risk of mortality for both genders. Women's risk of mortality was reduced by smoking reduction and higher cognitive vitality, and men's by emotional support and solitary leisure activity. Both men and women were resilient, yet there were differences. Gender-neutral mortality reduction programs would include physical activity, religious services, maintenance and improvement of ADL, and engaging in solitary leisure activities; for women, smoking cessation and cognitively challenging activities; and for men, maintaining or increasing emotional ties.  相似文献   
69.
Erythropoietin in heart failure   总被引:3,自引:0,他引:3  
The incidence of both congestive heart failure (CHF) and end-stage renal disease both are increasing. Anemia is common in both conditions and is associated with a marked increase in mortality and morbidity in both CHF and chronic kidney insufficiency (CKI). Each of these 3 conditions can cause or worsen the other 2. In other words, a vicious circle frequently is present in which CHF can cause or worsen both anemia and CKI, in which CKI can cause or worsen both anemia and CHF, and in which anemia can cause or worsen both CHF and CKI. We have called this vicious circle the cardio renal anemia syndrome. Optimal treatment of CHF with all the recommended CHF medications at their recommended doses will, in our experience, frequently fail to improve the CHF and CKI if anemia is present and is not corrected. On the other hand, correction of the anemia with subcutaneous erythropoietin and intravenous iron has caused a great improvement in the CHF including a marked improvement in patient and cardiac function and a marked reduction in the need for hospitalization and for high-dose diuretics. It also frequently has caused renal function to improve or at least stabilize. In addition, patients' quality of life and exercise capacity also have improved with the correction of the anemia. In CKI patients, anemia also may play an important role in increasing the risk for death, coronary heart disease, stroke, and progression to end-stage renal disease. Erythropoietin may have a direct positive effect on the heart and brain unrelated to correction of the anemia by reducing cell apoptosis and by increasing neovascularization, both of which could prevent tissue damage. This could have profound therapeutic implications not only in CHF but in the future treatment of myocardial infarction, coronary heart disease, strokes, and renal failure.  相似文献   
70.
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