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   975篇
  免费   93篇
  国内免费   21篇
耳鼻咽喉   5篇
儿科学   38篇
妇产科学   16篇
基础医学   182篇
口腔科学   12篇
临床医学   57篇
内科学   228篇
皮肤病学   11篇
神经病学   40篇
特种医学   98篇
外科学   135篇
综合类   4篇
预防医学   39篇
眼科学   7篇
药学   21篇
中国医学   2篇
肿瘤学   194篇
  2023年   9篇
  2022年   11篇
  2021年   18篇
  2020年   15篇
  2019年   17篇
  2018年   37篇
  2017年   23篇
  2016年   14篇
  2015年   27篇
  2014年   26篇
  2013年   40篇
  2012年   51篇
  2011年   48篇
  2010年   48篇
  2009年   43篇
  2008年   39篇
  2007年   48篇
  2006年   33篇
  2005年   30篇
  2004年   26篇
  2003年   29篇
  2002年   23篇
  2001年   22篇
  2000年   22篇
  1999年   12篇
  1998年   22篇
  1997年   16篇
  1996年   17篇
  1995年   18篇
  1994年   18篇
  1993年   20篇
  1992年   13篇
  1991年   10篇
  1990年   18篇
  1989年   25篇
  1988年   28篇
  1987年   25篇
  1986年   24篇
  1985年   17篇
  1984年   9篇
  1983年   14篇
  1982年   10篇
  1981年   5篇
  1980年   9篇
  1979年   4篇
  1978年   9篇
  1977年   14篇
  1976年   8篇
  1975年   7篇
  1973年   4篇
排序方式: 共有1089条查询结果,搜索用时 15 毫秒
91.

Objectives

To evaluate the use of shear wave elastography in assessment of kidney allograft tubulointerstitial fibrosis.

Methods

Shear wave elastography assessment was carried out by two independent operators in kidney transplant recipients who underwent allograft biopsy for clinical indications (i.e. rising creatinine >15% or proteinuria >1 g/day). Allograft biopsies were interpreted by the same pathologist according to the 2013 Banff Classification.

Results

A total of 40 elastography scans were carried out (median creatinine 172.5 μmol/L [interquartile range 133.8–281.8 μmol/L]). Median tissue stiffness at the cortex (22.6 kPa [interquartile range 18.8–25.7 kPa] vs 22.3 kPa [interquartile range 19.0–26.5 kPa], P = 0.70) and medulla (15.0 kPa [interquartile range 13.7–18.0 kPa] vs 15.6 kPa [interquartile range 14.4–18.2 kPa]) showed no significant differences between the two observers. Interobserver agreement was satisfactory (intraclass correlation coefficient of the cortex 0.84, 95% CI 0.70–0.92 and intraclass correlation coefficient of the medulla 0.88, 95% CI 0.78–0.94). The areas under the receiver operating characteristic curves for detection of tubulointerstitial fibrosis were estimated to be 0.75 (95% CI 0.61–0.89), 0.85 (95% CI 0.75–0.95) and 0.65 (95% CI 0.53–0.78) for cortical, medullary tissue stiffness and serum creatinine, respectively.

Conclusions

Shear wave elastography can be used as a non‐invasive tool to evaluate kidney allograft fibrosis with reasonable interobserver agreement and superior test performance to serum creatinine in detecting early tubulointerstitial fibrosis.  相似文献   
92.
SCH 56592 (posaconazole), a new triazole antifungal agent, was tested in vitro, and its activity was compared to that of itraconazole against 39 Aspergillus strains and to that of fluconazole against 275 Candida and 9 Cryptococcus strains. The SCH 56592 MICs for Aspergillus ranged from 64 microg/ml. SCH 56592 showed excellent activity against Aspergillus fumigatus and Aspergillus flavus in a pulmonary mouse infection model. When administered therapeutically, the 50% protective doses (PD(50)s) of SCH 56592 ranged from 3.6 to 29.9 mg/kg of body weight, while the PD(50)s of SCH 56592 administered prophylactically ranged from 0.9 to 9.0 mg/kg; itraconazole administered prophylactically was ineffective (PD(50)s, >75 mg/kg). SCH 56592 was also very efficacious against fluconazole-susceptible, -susceptible dose-dependent, or -resistant Candida albicans strains in immunocompetent or immunocompromised mouse models of systemic infection. The PD(50)s of SCH 56592 administered therapeutically ranged from 0.04 to 15.6 mg/kg, while the PD(50)s of SCH 56592 administered prophylactically ranged from 1.5 to 19.4 mg/kg. SCH 56592 has excellent potential for therapy against serious Aspergillus or Candida infections.  相似文献   
93.
Fluorescent light decreases autoimmunity and improves immunity in B/W mice   总被引:1,自引:0,他引:1  
Fluorescent light emitted from cool white tubular fluorescent lamps covered with standard acrylic lids decreased autoimmunity and enhanced immunity in the New Zealand Black/New Zealand White F1 hybrid female (B/W) mouse model of systemic lupus erythematosus (SLE). Thirty-three weeks of daily cool white fluorescent light exposure significantly decreased anti-ds DNA antibody levels and spleen size, and increased lymphocyte responsiveness to lipopolysaccharide (LPS) in B/W mice depilated to enhance light penetration. Depilation alone had no significant effect. The immunomodulatory potential of fluorescent light in B/W mice has not been previously appreciated, and may have important implications in SLE.  相似文献   
94.
Dasatinib is a potent tyrosine kinase inhibitor that is used to treat chronic myeloid leukemia in patients resistant or intolerant to imatinib mesylate. While designed to inhibit Abl and Src kinases, dasatinib shows multitarget effects, including inhibition of the macrophage colony‐stimulating factor (M‐CSF) receptor c‐fms. We have shown previously that dasatinib abrogates osteoclast formation and activity in vitro owing, in part, to its specificity for c‐fms. In this study we examined whether dasatinib could significantly alter bone volume in a model of physiologic bone turnover. Sprague‐Dawley rats were administered dasatinib (5 mg/kg/day) or vehicle by gavage or zoledronic acid (ZOL; 100 µg/kg/6 weeks) subcutaneously. Following 4, 8, and 12 weeks of treatment, serum biochemical, bone morphometric, and histologic analyses were performed. Whole‐body bone mineral density and tibial cortical thickness where unchanged in the dasatinib‐ or ZOL‐treated animals relative to controls. However, micro–computed tomographic (µCT) analysis of cancellous bone at the proximal tibias showed that trabecular volume (BV/TV) and thickness (Tb.Th) were increased in dasatinib‐treated animals at levels comparable with those of the ZOL‐treated group. These changes were associated with a decrease in osteoclast numbers (N.Oc/B.Pm) and surface (Oc.S/BS) and decreased serum levels of the osteoclast marker c‐terminal collagen crosslinks (CTX‐1). Mineral apposition rate (MAR), bone‐formation rate (BFR), and levels of the serum osteoblast markers osteocalcin and N‐terminal propeptide of type I procollagen (P1NP) were not altered significantly in the dasatinib‐treated animals relative to controls. These studies show that dasatinib increases trabecular bone volume at least in part by inhibiting osteoclast activity, suggesting that dasatinib therapy may result in dysregulated bone remodeling. © 2010 American Society for Bone and Mineral Research  相似文献   
95.
In most cases pancreatic cancer appears in a non-curatively resectable stage at time the diagnosis is made. Thus, palliative treatment concepts come to the fore in these patients. Patients without metastases, but presenting with marginally resectable or locally non-resectable tumours should not be treated in a palliative therapeutic scheme. These patients should be enrolled in neoadjuvant radiochemotherapy trials. After finishing treatment and restaging, a potentially curative resection can be achieved in approximately one-third of these patients. Within the scope of the best possible palliative care, excision of metastases together with resection of the primary cancer represents a therapeutic option to be contemplated in selected cases. For distinct locally unresectable or metastasised advanced pancreatic cancer, treatment of bile duct or duodenal obstruction is an essential part of the comprehensive palliative therapy. However, both endoscopic?/?percutaneous stenting procedures and surgical bypass makeshifts constitute safe and highly effective therapeutic alternatives in this context. In the case of operative drainage of the biliary tract the prophylactic creation of a gastro-intestinal bypass (double bypass) is recommended. The decision on a surgical versus an endoscopic procedure for palliation depends considerably on the tumour stage and the estimated prognosis and has to be determined interdisciplinary and individually in each case.  相似文献   
96.
The plasma cell (PC) malignancy, multiple myeloma (MM), is unique among hematological malignancies in its capacity to cause osteoclast (OC)‐mediated skeletal destruction. We have previously shown that elevated plasma levels of PC‐derived CXCL12 are associated with presence of X‐ray detectable osteolytic lesions in MM patients. To further investigate this relationship, plasma levels of CXCL12 and βCrossLaps, a marker of bone loss, were measured. A strong correlation between levels of CXCL12 and OC‐mediated bone resorption was identified. To confirm the OC‐activating potential of MM PC‐derived CXCL12 in vivo, we established a model of MM‐mediated focal osteolysis, wherein MM PC lines, such as RPMI‐8226, were injected into the tibias of nude mice. Implanting RPMI‐8226 gave rise to osteolytic lesions proximal to the tumor, resulting in a 5% decrease in bone volume (BV) compared with vehicle control. Importantly, bone loss was significantly inhibited with systemic administration of the CXCL12/CXCR4 antagonist T140. Furthermore, implanting CXCL12‐overexpressing RPMI‐8226 cells resulted in a 13% decrease in BV and was associated with increased OC recruitment proximal to the tumor, increased serum matrix metalloproteinase activity, and increased levels of collagen I degradation products. These findings confirm our hypothesis that MM PC‐derived CXCL12 stimulates the recruitment and activity of OC, thereby contributing to the formation of MM osteolytic lesions.  相似文献   
97.
Giant cell tumor of bone (GCTB) is a benign bone tumor with a shown clinical behavior of local recurrences and rare distant metastases. GCTB is composed of uniformly distributed osteoclastic giant cells, thought to originate from the fusion of monocyte–macrophage lineage cells, in a background consisting of mononuclear rounded cells and spindle‐shaped cells. Several reports showed the specific expression of markers, such as CD14 on the mononuclear rounded cell population, however, lacking osteoclastic giant cells. Blood monocytes that were CD14+, CD33+, or CD14+/CD33+ have also been shown to be programmed as pre‐osteoclasts. The macrophage marker CD33 is expressed earlier than CD14 in macrophage maturation, whereas CD14 is expressed longer than CD33. The aim of this study was to investigate CD14/CD33 expression profiles in GCTB. Nineteen GCTB tumor samples of 19 patients were studied. Immunofluorescent analyses were performed with monoclonal antibodies against CD14, CD33, RANK, and CD51. To unambiguously further prove the expression of these molecules, quantitative RT‐PCR was used with subsequent sequencing of its products. All samples showed similar immunoreactivity profiles. The mononuclear rounded cell population was positive for RANK, CD51, CD14, and CD33. The osteoclastic giant cell population expressed RANK and CD51, as well as CD33, but was consistently negative for CD14 expression. The CD14 and CD33 profiles were confirmed by quantitative RT‐PCR. These RT‐PCR products were sequence verified. Osteoclasts in GCTB are the result of fusion of CD33‐expressing pre‐osteoclasts that further fuse with CD14+ mononuclear cells. Although these results reflect a static rather than a dynamic spectrum, we strongly believe that osteoclastogenesis seems not to be the exclusive result of fusion of intratumoral CD14+ mononuclear cells. Moreover, CD33‐modulated osteoclastogenesis opens up the possibility for novel therapeutic directions.  相似文献   
98.
INTRODUCTION: Metastatic involvement of the peritoneum from a lung cancer is infrequently encountered. METHODS: We present the case report of a patient with bronchial adenocarcinoma whose course is complicated by the occurrence of a peritoneal carcinomatosis, as documented by FDG-PET. CONCLUSION: Unexplained abdominal pain in a lung cancer patient may be a peritoneal carcinomatosis. The diagnosis can be helped by PET-scan. However, the therapeutic opportunities are very limited.  相似文献   
99.
PURPOSE: This study is aimed at understanding and defining the current patterns of care with respect to prostate brachytherapy for patients with intermediate-risk localized disease in the combined academic and community setting. METHODS AND MATERIALS: A nomogram-based survey was developed at the Seattle Prostate Institute defining the accepted criteria for intermediate-risk prostate cancer. Patients were defined as having intermediate-risk prostate cancer if they met one of the following criteria: prostate-specific antigen (PSA) >10 ng/dL, Gleason score (GS) > or = 7, or cT2b or cT2c disease. Additional potential predictive factors including perineural invasion (PNI), GS 3+4 vs. 4+3, and high-volume disease were included. RESULTS: In the absence of PNI, all of those surveyed would perform monotherapy for intermediate-risk patients, GS 7 (3+4) or PSA 10-20, with cT1c and <30% cores +. Up to 80% would perform monotherapy for patients with cT1c, GS 7 (4+3), and <30% cores +. Eighty to 90% of physicians would perform an implant alone with cT2a and either a PSA of 10-20 or GS of 7 (3+4) and <30% cores +. Fifty to 60% of those surveyed stated that they would treat a patient with cT2b disease, GS 7 (3+4), or PSA 11-20, with less than two-thirds of the biopsy cores positive in the absence of PNI. CONCLUSIONS: This Patterns of Care (POC) study reveals that certain subsets of intermediate-risk localized prostate cancer patients are considered appropriate candidates for an interstitial implant alone.  相似文献   
100.
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