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   760篇
  免费   44篇
  国内免费   2篇
耳鼻咽喉   27篇
儿科学   2篇
妇产科学   9篇
基础医学   105篇
口腔科学   1篇
临床医学   39篇
内科学   158篇
皮肤病学   4篇
神经病学   29篇
特种医学   58篇
外科学   184篇
综合类   2篇
预防医学   16篇
眼科学   4篇
药学   32篇
肿瘤学   136篇
  2023年   7篇
  2022年   5篇
  2021年   22篇
  2020年   8篇
  2019年   11篇
  2018年   29篇
  2017年   17篇
  2016年   30篇
  2015年   29篇
  2014年   53篇
  2013年   55篇
  2012年   67篇
  2011年   82篇
  2010年   53篇
  2009年   36篇
  2008年   47篇
  2007年   53篇
  2006年   36篇
  2005年   33篇
  2004年   30篇
  2003年   26篇
  2002年   17篇
  2001年   18篇
  2000年   16篇
  1999年   7篇
  1998年   1篇
  1997年   5篇
  1996年   1篇
  1994年   1篇
  1993年   3篇
  1986年   2篇
  1984年   1篇
  1982年   2篇
  1961年   3篇
排序方式: 共有806条查询结果,搜索用时 31 毫秒
81.
Rha SE  Lee MG  Lee YS  Kang GH  Ha HK  Kim PN  Auh YH 《Abdominal imaging》2000,25(3):255-258
We report the imaging findings of spiral computed tomography (CT), magnetic resonance (MR) imaging, and MR angiography in a patient with nodular regenerative hyperplasia of the liver associated with Budd–Chiari syndrome. Spiral CT showed multiple enhancing nodules during the hepatic arterial and portal venous phases. MR images showed multiple hyperintense nodules on T1-weighted images and hypointense or isointense nodules on T2-weighted images. MR angiography showed thrombotic occlusion of three hepatic veins, suggesting Budd–Chiari syndrome. Received: 25 June 1999/Revision accepted: 22 September 1999  相似文献   
82.
Bivalirudin (Angiomax) is increasingly used as a substitute for heparin in a variety of percutaneous coronary interventions, and data on its usage in saphenous vein graft interventions are limited. This retrospective, observational study evaluated the efficacy and safety of bivalirudin compared with heparin as an antithrombotic regimen in patients who underwent saphenous vein graft intervention with distal protection devices. We found that bivalirudin use is clinically safe and feasible, with fewer vascular and ischemic complications compared with heparin.  相似文献   
83.

Background

Nasal polyposis is characterized by persistent inflammation and remodeling in sinonasal mucosa. Toll‐like receptor 9 (TLR9) is a DNA receptor of the innate immune system that plays a pivotal role in fibrosis and inflammatory responses. The aim of this study is to explore the expression, activity, and potential pathogenic role of TLR9 signaling in tissue remodeling in nasal polyp–derived fibroblasts (NPDFs).

Methods

Fibrotic and inflammatory responses elicited by type A CpG oligonucleotides were examined in the NPDFs by a combination of real‐time quantitative polymerase chain reaction, Western blot analysis, enzyme‐linked immunosorbent assay, and immunofluorescence staining. For these experiments, the NPDFs were stimulated with different TLR9 agonists (CpG A and B) and blocked with inhibitors (MyD88 inhibitor and chloroquine).

Results

TLR9 expression was significantly higher in nasal polyposis (NP) tissues compared to control or chronic rhinosinusitis (CRS) mucosa. In the NPDFs, TLR9 showed intracellular localization and expression of TLR9 was increased after treatment with CpG A. CpG A increased production of α‐smooth muscle actin (α‐SMA), fibronectin, and matrix metalloproteinases (MMPs) (MMP1, MMP2, and MMP9) in the NPDFs, while MyD88 inhibitor and chloroquine, which are known to block the TLR9 signaling pathway, inhibited their production. CpG A also produced type I interferons (IFN‐α and IFN‐β), which were inhibited by MyD88 inhibitor.

Conclusion

Our data indicates that CpG A–induced fibroblast activation and cytokine production were mediated via TLR9 stimulation in NPDFs. Disrupting this process with an inhibitor targeting TLR9 or its downstream signaling pathways could represent a novel approach to CRS with NP (CRSwNP) therapy.
  相似文献   
84.
85.
In recent years, characterization of cancer and its environment has become necessary. However, studies of the cancer microenvironment remain insufficient. Copy number variations (CNVs) occur in 40% of cancer‐related genes, but few studies have reported the correlation between CNVs in morphologically normal tissues adjacent to cancer and cancer progression. In this study, we evaluated cancer cell migration and invasion according to the genetic differences between cancer tissues and their surrounding normal tissues. To study the field cancerization effect, we screened 89 systemic metastasis‐related CNVs from morphologically normal tissues adjacent to colon cancers. Among these CNVs, LIM and senescent cell antigen‐like domain 2 (PINCH‐2) showed copy number amplification and upregulation of mRNA in the nonrelapsed group compared to the systemic relapse group. PINCH‐2 expression in colon cancer cells was lower than that in normal epithelial colon cells at both the protein and mRNA levels. Suppression of PINCH‐2 resulted in decreased formation of the PINCH‐2‐IPP (PINCH‐2, integrin‐linked kinase and α‐parvin) complex and reciprocally increased formation of the PINCH‐1‐IPP complex. Although PINCH‐2 expression of survival pathway‐related proteins (Akt and phospho‐Akt) did not change upon suppression of PINCH‐2 expression, cell migration‐related proteins [matrix‐metalloproteinase (MMP)?9 and ?11] were upregulated through autocrine and paracrine activation. Thus, PINCH‐2 participates in decreased systemic recurrence by competitively regulating IPP complex formation with PINCH‐1, thereby suppressing autocrine and paracrine effects on motility in colon cancer. This genetic change in morphologically normal tissue suggests a field cancerization effect of the tumor microenvironment in cancer progression.  相似文献   
86.
Perovskite solar cells (PSCs) fabricated on transparent polymer substrates are considered a promising candidate as flexible solar cells that can emulate the advantages of organic solar cells, which exhibit considerable freedom in their device design thanks to their light weight and mechanically flexibility while achieving high photocurrent conversion efficiency, comparable to that of their conventional counterparts fabricated on rigid glasses. However, the full realization of highly efficient, flexible PSCs is largely prevented by technical difficulties in simultaneously attaining a transparent electrode with efficient charge transport to meet the specifications of PSCs. In this study, an effective strategy for resolving this technical issue has been devised by proposing a simple but highly effective technique to fabricate an efficient, multilayer TiO2/Ag(O)/ZnO (TAOZ) configuration. This configuration displays low losses in optical transmittance and electrical conductivity owing to its completely continuous, ultrathin metallic Ag(O) transparent electrode, and any notable current leakage is suppressed by its pinhole-free TiO2 electron transport layer. These features are a direct consequence of the rapid evolution of Ag(O) and TiO2 into ultrathin, completely continuous, pinhole-free layers owing to the dramatically improved wetting of metallic Ag(O) with a minimal dose of oxygen (ca. 3 at%) during sputtering. The TAOZ configuration exhibits an average transmittance of 88.5% in the spectral range of 400–800 nm and a sheet resistance of 8.4 Ω sq−1 while demonstrating superior mechanical flexibility to that of the conventional TiO2 on ITO configuration. The photocurrent conversion efficiency of flexible PSCs is significantly improved by up to 11.2% thanks to an optimum combination of optoelectrical performance and pinhole-free morphologies in the TAOZ configuration.

A TiO2/Ag(O)/ZnO configuration is developed for flexible perovskite solar cells to provide a pinhole-free electron transport layer and a transparent electrode.  相似文献   
87.
The Washington Radiation for In-Stent Restenosis Trial in Saphenous Vein Grafts (SVG WRIST) demonstrated safety and efficacy of intravascular radiation therapy (IRT) for the treatment of in-stent restenosis (ISR) in SVG at 12 months. In this study, we aimed to examine whether the safety and efficacy of IRT is durable up to 36 months. One hundred twenty patients with diffuse ISR in SVG underwent balloon angioplasty, laser or atherectomy ablation, and/or additional stenting. After successful intervention, patients were randomly assigned in a double-blind fashion to intravascular treatment with a ribbon containing either iridium (Ir)-192 (n = 60) or nonradioactive seeds (n = 60). The prescribed dose at 2 mm from the source was either 14 or 15 Gy in vessels 2.5-4.0 mm or 18 Gy in vessels > 4.0 mm in diameter. At 36 months, target lesion revascularization (TLR; 43% vs. 66%; P = 0.02) and target lesion revascularization-major adverse cardiac event (TLR-MACE; 49% vs. 71%; P = 0.02) rates continued to be lower in the IRT group, but both target vessel revascularization (TVR; 59% vs. 71%; P = 0.17) and TVR-MACE (63% vs. 77%; P = 0.11) rates were not. In SVG WRIST, patients with ISR treated with IRT had a marked reduction in the need for repeat TLR at 36 months, with sustained clinical benefit at 3 years despite late recurrences, which were more pronounced in the radiation group.  相似文献   
88.
Objective To evaluate the apurinic/apyrimidinic endonuclease 1 (APE1) expression in sinonasal squamous cell carcinomas (SCC) and to examine the correlation between APE1 expression patterns and various clinicopathological factors associated with sinonasal SCC that include SCC with inverted papilloma (SCCwIP) and SCC alone. Study Design Case-control study. Setting Chungnam National University Hospital. Subjects and Methods The expressions of APE1 were analyzed by means of immunohistochemistry in 30 sinonasal SCC, including 14 SCC patients associated with IP and 16 patients with SCC alone. A total of 19 patients who had been diagnosed with chronic rhinosinusitis with nasal polyposis and who required endoscopic sinus surgery were used as the control group. The degrees of APE1 expression were analyzed with respect to the following clinicopathologic variables: age, sex, T stage, histologic differentiation, distant metastasis, and recurrence. Results Cytoplasmic staining of APE1 was significantly higher in SCC compared with SCCwIP (68.75% vs 14.29%). Cytoplasmic staining of APE1 was significantly associated with T stage (P = .044) in SCC and histologic grade (P = .0025) in sinonasal SCC. Nuclear staining of APE1 was significantly associated with distant metastasis (P = .022) in SCC. Conclusion These results suggest that the nuclear and cytoplasmic expression of APE1 may be related to tumor invasiveness and prognosis in sinonasal SCC. The suppression of APE1 expression can potentially be a new target for future sinonasal SCC therapies.  相似文献   
89.

Purpose

Previous studies have not defined the role of telemonitoring with educational tools in outpatients with advanced cancers. We tested the effectiveness of standardized education and telemonitoring for improving pain, distress, anxiety, depression, quality of life (QoL), and performance in outpatients with advanced cancers.

Methods

A total of 108 patients were randomly assigned to receive pain education alone (control arm) or pain education plus telemonitoring (experimental arm). Nursing specialists provided video-assisted educational material in both arms and daily telemonitoring for the first week in the experimental arm. Assessment was performed at baseline and 1 week and included evaluations of pain (Brief Pain Inventory, BPI), distress (Distress Thermometer, DT), anxiety, and depression (Hospital Anxiety and Depression Scale, HADS), QoL (QLQ-C30), and a Karnofsky score.

Results

Overall (n?=?108), pain intensity was significantly improved at 1 week, including worst pain (7.3 to 5.7, P?<?0.01) and average pain (4.6 to 3.8, P?<?0.01). Additionally, anxiety (HADS score?≥?11, 75 % to 56 %, P?<?0.01), depression (HADS score?≥?11, 73 % to 51 %, P?<?0.01), QoL (fatigue and insomnia), and the Karnofsky score (32 to 66, P?<?0.01) were also significantly improved at 1 week. However, the level of distress did not improve. The telemonitoring plus standardized education group showed more significant improvement in portion of pain >4 on VAS scale (35 % vs. 19 %, P?=?0.02).

Conclusions

Standardized pain education using nursing specialists is an efficient way to improve not only pain itself but also anxiety, depression, performance, and QoL. The addition of telemonitoring helps to improve pain management in the outpatient setting.  相似文献   
90.
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