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   762篇
  免费   55篇
  国内免费   7篇
耳鼻咽喉   5篇
儿科学   61篇
妇产科学   48篇
基础医学   73篇
口腔科学   36篇
临床医学   73篇
内科学   215篇
皮肤病学   12篇
神经病学   36篇
特种医学   69篇
外科学   82篇
综合类   18篇
预防医学   35篇
药学   25篇
  1篇
中国医学   1篇
肿瘤学   34篇
  2023年   4篇
  2021年   12篇
  2020年   5篇
  2019年   7篇
  2018年   12篇
  2017年   8篇
  2016年   14篇
  2015年   36篇
  2014年   33篇
  2013年   33篇
  2012年   31篇
  2011年   38篇
  2010年   37篇
  2009年   22篇
  2008年   30篇
  2007年   26篇
  2006年   23篇
  2005年   32篇
  2004年   20篇
  2003年   14篇
  2002年   14篇
  2001年   22篇
  2000年   21篇
  1999年   12篇
  1998年   28篇
  1997年   24篇
  1996年   32篇
  1995年   22篇
  1994年   24篇
  1993年   18篇
  1992年   8篇
  1991年   5篇
  1990年   10篇
  1989年   8篇
  1988年   19篇
  1987年   10篇
  1986年   8篇
  1985年   17篇
  1984年   9篇
  1983年   12篇
  1982年   4篇
  1981年   3篇
  1980年   3篇
  1979年   5篇
  1978年   3篇
  1977年   10篇
  1976年   8篇
  1975年   8篇
  1968年   3篇
  1963年   2篇
排序方式: 共有824条查询结果,搜索用时 15 毫秒
101.
Lymphomas may be induced by the systemic immunosuppressive therapies used to treat psoriasis,such as ciclosporin,methotrexate and tumour necrosis factor(TNF)-α blockers.The biologic agents currently used in psoriasis include alefacept,efalizumab,and the TNF-α antagonists etanercept,infliximab,and adalimumab.Infections and cancer are the main possible consequences of intended or unexpected immunosuppression.We report a 59-year-old man with a history of severe psoriasis vulgaris treated with traditional immunosuppressant drugs followed by anti-TNF-α therapy;the patient was firstly hospitalized for an acute cholestatic toxic hepatitis,which we supposed to be related to adalimumab.The first liver biopsy showed active disease with severe hepatocellular damage caused by heavy lymphocytes infiltrate in portal tracts at in the interface with a not conclusive diagnosis of lymphoproliferative disease.The correct diagnosis of T cell/histiocyte-rich large B cell lymphoma(T/HRBCL) was only reached through a gastric biopsy and a second liver biopsy.T/HRBCL is an uncommon morphologic variant of diffuse large B-cell lymphoma not described until now in psoriatic patients receiving immunosuppressive biologic agents.In psoriatic patients,treated with biologic immunosuppressive agents,the suspect of abdominal lymphoma should always be included as differential diagnosis.Abdominal ultrasound evaluation need therefore to be included in the pretreatment screening as in the follow-up surveillance.  相似文献   
102.
Private health insurance plays a key role in financing dental care in Australia. Having private dental insurance has been associated with higher levels of access to dental care, visiting for a check‐up and receiving a favourable pattern of services. Associations with better oral health have also been reported. In the absence of any existing review, this paper aims to systematically review the relationship between dental insurance and dental service use and/or oral health outcomes in Australia. A systematic search of online databases and subsequent sifting resulted in 36 publications, 33 of which were cross sectional and three cohort analyses. Dental service outcomes were more commonly reported than oral health outcomes. There was considerable heterogeneity in the outcome measures reported, for both service use and health outcomes. Overall, the majority of the evidence was from cross sectional studies and few studies reported analyses adjusted for confounding factors. The consolidated evidence points towards a positive association between dental insurance and dental visiting. Dentally insured adults are likely to have more regular access to dental care and have a more favourable pattern of service use than the uninsured. However, evidence of associations between dental insurance and oral health are mixed.  相似文献   
103.
PIXY321 is a novel fusion protein of recombinant human granulocyte- macrophage colony-stimulating factor and interleukin-3 that exhibits biologic effects of both its parent cytokines in vitro and in preclinical studies. To evaluate the clinical safety and hematopoietic effects of this hybrid cytokine, PIXY321 was administered by subcutaneous injection twice daily at doses of 25 to 1,000 micrograms/m2/day over 14 days to 24 patients with sarcoma before chemotherapy as part of a phase I trial. The treatment was associated with significant increases in white blood cell, neutrophil, platelet, and reticulocyte counts (all P < .001). The increase in neutrophil count was dose-related and was seen during treatment with the cytokine, whereas the increase in platelet count was gradual and peaked after the cessation of the cytokine treatment and was not clearly dose related. PIXY321 treatment also increased bone marrow (BM) cellularity and the percentage of BM cells in S phase (P < .001). In addition, there was a significant increase in the number of CD34+ cells and committed and multipotential progenitors in the peripheral blood. The ex vivo expansion capacity of peripheral blood and BM progenitor cells was preserved after the in vivo treatment with PIXY321. The treatment was well tolerated, with the most common side-effect being injection site reactions. The results of this study show the biologic and clinical activity of a genetically engineered fusion molecule of two hematopoietic cytokines in humans with normal hematopoietic function.  相似文献   
104.
Braziel  RM; Sussman  E; Jaffe  ES; Neckers  LM; Cossman  J 《Blood》1985,66(1):128-134
B cell neoplasms are clonal expansions of B lymphocytes thought to be frozen at various points along the normal B cell differentiation pathway. We studied cell suspensions from lymph nodes involved by follicular (nodular) non-Hodgkin's lymphoma to determine the capacity of the malignant B cells to secrete immunoglobulin (Ig). Neoplastic B cells from all 14 follicular lymphomas secreted monoclonal immunoglobulin in culture when appropriate signals were provided. In most cases, maximal Ig secretion occurred when autologous T cells were removed by E rosette depletion, replaced with allogeneic normal T cells, and the cultures were exposed to 12-O-tetradecanoylphorbol-13- acetate. Autologous T cells exerted a suppressor effect on Ig secretion in 8/8 cases studied, diminishing the response of the malignant B cells to allogeneic T cells. This suppressor effect did not correlate with the percentage of cells staining with anti-Leu-2a or with "helper- suppressor" (Leu-3a-Leu-2a) ratios of the lymph node T cells. Our findings demonstrate that the arrested differentiation of most follicular lymphomas is reversible and implicate a T cell-mediated host immunoregulatory mechanism affecting Ig secretion in vivo. An additional contribution of our results is the demonstration of a cell culture system for synthesis of sufficient monoclonal Ig for use as an immunogen in production of anti-idiotype antibodies.  相似文献   
105.
During active sleep, neonates exhibit asynchronous chest wall movements, which have been associated with a small but significant decrease in oxygenation. To determine the effects of maturation and residual chronic lung disease on both these phenomena, we studied 11 preterm infants with resolving bronchopulmonary dysplasia (BPD) and compared these infants to ten healthy preterm infants all at time of discharge. Synchrony of chest wall (upper rib cage and abdominal) movements, sleep state, O2 saturation, and transcutaneous CO2 (TcPCO2) were recorded during both active (AS) and quiet sleep (QS). Sleep state was determined by electroencephalographic and behavioral criteria. Normal preterm infants displayed asynchronous chest wall movements only in AS, whereas, in infants with BPD, asynchrony predominated in both sleep states, although O2 saturation and TcPCO2 did not differ between sleep states in either group. The O2 saturation during AS was lower in the BPD group than in the group of normal infants (92% vs 96%; P less than 0.02), whereas TcPCO2 was higher in the BPD group unrelated to sleep state. We conclude that infants with resolving BPD exhibit asynchronous chest wall movements in both AS and QS, and that change in sleep state from QS to AS is not associated with a detrimental fall in oxygenation in these infants.  相似文献   
106.
Cossman  J; Jaffe  ES 《Blood》1981,58(1):20-26
Surface receptors specific for either the C4b (CR1) or C3d (CR2) component of complement were examined on the neoplastic cells from 30 cases of non-Hodgkin's lymphoma of B-cell origin and on cells derived from 9 normal lymphoid tissues. Lymphocyte suspensions from non- neoplastic peripheral blood, tonsils, and lymph node contained three categories of complement receptor lymphocytes (CRL): cells with receptors for both C4b and C3d (CR1+, CR2+); cells with receptors for C4b but not C3d (CR1+, CR2-), and cells with receptors for C3d but not C4b (CR1-, CR2+). The mean of the proportion of total CRL expressing receptors only of C3d (CR1-, CR2+) was 0.35 for non-neoplastic tissues and 0.28 for malignant lymphomas of follicular center cell (FCC) origin. However, the proportion of cells with this phenotype was significantly higher in well differentiated lymphocytic lymphomas (WDL) and chronic lymphocytic leukemia (CLL) (0.65) and in intermediately differentiated lymphocytic lymphomas (IDL) (0.59). Histologic compartmentalization of the CRL subtypes was observed in frozen sections of normal lymphoid tissue. CR1+ cells were present in lymphoid follicles interfollicular areas, and in splenic red pulp. CR2+ cells were confined to lymphoid follicles. These findings strongly suggest that complement receptor phenotypes may be useful markers of B-cell differentiation.  相似文献   
107.
Ghetie  MA; Picker  LJ; Richardson  JA; Tucker  K; Uhr  JW; Vitetta  ES 《Blood》1994,83(5):1329-1336
In this report, we extend our previous findings that IgG or F(ab')2 fragments of HD37 anti-CD19 antibody (Ab) in combination with the immunotoxin (IT), RFB4-anti-CD22-deglycosylated ricin A chain (dgA) (but neither reagent alone), prolonged the survival of SCID mice with disseminated human Daudi lymphoma (SCID/Daudi mice) to 1 year at which time they still remained tumor-free. We explored the mechanisms by which the HD37 Ab exerts antitumor activity in vivo by studying its activity in vitro. We found that it has antiproliferative activity (IC50 = 5.2 - 9.8 x 10(-7) mol/L) on three CD19+ Burkitt's lymphoma cell lines (Daudi, Raji, and Namalwa) but not on a weakly CD19-positive (CD19lo) pre-B cell tumor (Nalm-6). The inhibitory effect was manifested by cell cycle arrest, but not apoptosis. Results using three additional anti-CD19 Abs, suggest that the affinity of the antibody and possibly the epitope which it recognizes may effect its capacity to transmit a signal that induces cell cycle arrest. Hence, therapeutically useful Abs may exert anti-tumor activity by a variety of mechanisms, each of which should be evaluated before undertaking clinical trials in humans.  相似文献   
108.
We examined if height loss in older women predicts risk of hip fractures, other nonspine fractures, and mortality, and whether this risk is independent of both vertebral fractures (VFx) and bone mineral density (BMD) by dual‐energy X‐ray absorptiometry. Among 3124 women age 65 and older in the Study of Osteoporotic Fractures, we assessed the association with measured height change between year 0 (1986–1988) and year 15 (2002–2004) and subsequent risk of radiologically confirmed hip fractures, other nonspine fractures, and mortality assessed via death certificates. Follow‐up occurred every 4 months for fractures and vital status (>95% contacts complete). Cox proportional hazards models assessed risk of hip fracture, nonspine fracture, and mortality over a mean of 5 years after height change was assessed (ie, after final height measurement). After adjustment for VFx, BMD, and other potential covariates, height loss >5 cm was associated with a marked increased risk of hip fracture [hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.06, 2.12], nonspine fracture (HR 1.48; 95% CI 1.20, 1.83), and mortality (1.45; 95% CI 1.21, 1.73). Although primary analyses were a subset of 3124 survivors healthy enough to return for a year 15 height measurement, a sensitivity analysis in the entire cohort (n = 9677) using initial height in earlier adulthood [self‐reported height at age 25 (?40 years) to measured height age >65 years (Year 0)] demonstrated consistent results. Height loss >5 cm (2″) in older women was associated with a nearly 50% increased risk of hip fracture, nonspine fracture, and mortality—independent of incident VFx and BMD. © 2012 American Society for Bone and Mineral Research  相似文献   
109.
110.
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