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   47篇
  免费   1篇
妇产科学   1篇
基础医学   8篇
口腔科学   1篇
临床医学   7篇
内科学   4篇
皮肤病学   2篇
神经病学   2篇
特种医学   2篇
外科学   17篇
预防医学   1篇
药学   2篇
肿瘤学   1篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2019年   1篇
  2018年   3篇
  2016年   2篇
  2014年   5篇
  2013年   5篇
  2012年   3篇
  2011年   2篇
  2010年   3篇
  2008年   2篇
  2007年   5篇
  2006年   3篇
  2005年   3篇
  2004年   2篇
  2002年   1篇
  2001年   1篇
  2000年   1篇
  1992年   1篇
  1990年   1篇
排序方式: 共有48条查询结果,搜索用时 15 毫秒
1.
MoS2 is a very attractive material and has been well studied for potential applications in various areas. However, due to the wide variety of factors affecting the molecular and electronic structure of MoS2, several contradictory reports about the adsorptive and photocatalytic properties of such materials have been published. In most of these reports, the effect of the actual phase of the materials on the properties was neglected. Here, different phases of MoS2 nanosheets (1T/2H, 1T/3R and 2H) have been obtained using the hydrothermal method with different Mo : S molar ratios and different autoclave filling ratios. The obtained materials have been thoroughly characterized using Raman, UV-vis, powder XRD, SEM, TEM and XPS measurements in order to accurately identify the existing phases in each material. A comparative study of the photocatalytic organic dye degradation efficiency under white light irradiation has been conducted using methyl orange to correlate the different activity of each material to the respective phase composition. The results indicate a much higher performance of the 1T/2H phase compared to the 2H and 3R phases. Detailed computational studies of the different phases revealed the emergence of mid-gap states upon introducing 1T sites into the 2H lattice. This leads to the improvement of the photocatalytic activity of 1T/2H compared to the other prepared materials.

MoS2 is a very attractive material and has been well studied for potential applications in various areas.  相似文献   
2.

Background

The serum neutrophil–lymphocyte ratio (NLR) is associated with outcomes in several solid organ cancers, including hepatocellular carcinoma (HCC).

Methods

We reviewed our experience in patients with HCC who underwent transarterial chemoembolization (TACE) as the initial treatment. Serum complete blood counts were used to calculate the NLR before and after TACE. The Kaplan–Meier method was used to determine survival and significant differences between groups by the log-rank test.

Results

There were 103 patients identified who underwent TACE for HCC. The median age was 60.5 years. Median overall survival was 12.6 (95 % confidence interval 8.3–17) months. Median survival in patients with a high preprocedural NLR was 4.2 months compared to 15 months in those with a normal NLR (p = 0.021). In those whose NLR either rose 1 month after treatment or remained elevated, survival was worse compared to those who normalized or remained normal (18.6 vs. 10.6 months, p = 0.026). The same was true at 6 months (21.3 vs. 9.5 months, p = 0.002). An unresponsive NLR was associated with very poor outcome (median survival 3.7 months). Multivariate analysis of clinicopathologic factors showed that presence of extrahepatic disease and high NLR were independent factors associated with worse survival.

Conclusions

Our study demonstrates that periprocedural trends of serum NLR are associated with outcome in unresectable HCC undergoing TACE. Serum NLR is easy to calculate from a routine complete blood count with differential. Along with liver function, serum NLR may be helpful to clinicians in providing prognostic information and monitoring response to therapy.  相似文献   
3.

Introduction

We hypothesized that an elevated preoperative alkaline phosphatase (AP) predicted worse outcomes for patients undergoing transarterial chemoembolization (TACE) for neuroendocrine tumor (NET) liver metastases.

Methods

We reviewed all patients who underwent TACE for metastatic NET between 2009 and 2013. Survival was evaluated using preprocedure variables.

Results

One hundred and nine patients underwent 210 TACE procedures. The average age was 57.7 years (range 20–78). Primary sites included pancreas (N?=?20), other gastrointestinal (N?=?52), lung (N?=?9), and unknown (N?=?28). The tumor was grade 1 in 68 (62 %), grade 2 in 21 (19 %), and grade 3 in 3 (3 %). Extrahepatic disease was present in 54 (50 %) and greater than 50 % hepatic tumor burden by imaging in 63 (58 %). Elevated bilirubin occurred in 8 (7 %), elevated AP in 22 (20 %), elevated ALT in 21 (19 %), and elevated AST in 41 (38 %). Univariate predictors included tumor grade (43 vs 27 vs 21 months, p?=?0.015), hepatic tumor burden (59 vs 37 months, p?=?0.009), and elevated AP (59 vs 23 months, p?<?0.001). On multivariate analysis, only elevated AP (p?=?0.001) predicted worse survival.

Conclusions

Elevated AP prior to TACE for metastatic NET portends a worse survival outcome, even more so than tumor grade or extent of hepatic disease.
  相似文献   
4.
5.
6.
We report the destructive adsorption of Diazinon pesticide by porous webs of activated carbon nanofibers containing Al2O3 and MgO nanoparticles. The results show that, the presence of Al2O3 and MgO nanoparticles in the activated carbon nanofibers increases the amount of destructively adsorbed Diazinon pesticide by activated carbon nanofibers. Moreover, type, amount, and specific surface area of metal oxide nanoparticles affect the adsorption rate as well as the total destructively adsorbed Diazinon. Liquid chromatography proved the degradation of Diazinon by chemical reaction with Al2O3 and MgO nanoparticles. Liquid chromatography–mass spectrometry showed that the main product of reaction between Diazinon and the metal oxides is 2-isopropyl-6-methyl-4-pyrimidinol with less toxicity than Diazinon.  相似文献   
7.
Because the use of radioactive fibrinogen uptake test (FUT) has become questionable both for ethical (risk of virus transmission) and technical (lack of sensitivity) reasons, we investigated the potential value of two alternative methods for screening of asymptomatic deep venous thrombosis following elective digestive surgery: liquid crystal contact thermography (LCCT) and measurement of plasma concentration of D-dimer (DD), as compared with bilateral ascending phlebography. Out of 194 patients, 185 underwent phlebography on the 8th (0-19, median and range) postoperative day. Despite prophylaxis with low-molecular-weight heparin and elastic stockings, DVT was detected on phlebography in 58 legs of 45 patients. Sensitivity of LCCT with respect to the presence of DVT was 55% (n = 184 patients) or 28% (n = 368 legs) with a specificity of 67% and 82%, respectively. These poor performances were obtained despite a good interobserver agreement for the LCCT assessments (overall kappa coefficient of 0.66 between three experts). The most accurate cut-off of DD for discriminating patients with or without DVT was 3,000 micrograms/l, as determined by ROC curve analysis. Sensitivity of a DD level of more than 3,000 micrograms/l for the presence of phlebographically documented DVT on the 8th postoperative day was 89% for a specificity of 48%. Thus, LCCT cannot be used for screening of postoperative, mainly asymptomatic DVT following general surgery. On the other hand, measurement of plasma DD may be useful for initial screening, a negative result (level less than 3,000 micrograms/l) allowing to exclude DVT (negative predictive value of 93%) and a positive result (positive predictive value of 35%) requiring confirmation by phlebography.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
8.
BackgroundFew patients with metastatic colorectal cancer (mCRC) are candidates for resection of their hepatic disease. Yttrium-90 (90Y) radioembolization has promise in the treatment of unresectable mCRC. We conducted a retrospective study to assess the efficacy in patients with refractory mCRC who underwent 90Y radioembolization.Materials and methodsPatients with unresectable mCRC with liver metastases treated at The Ohio State University were included in this analysis. Demographic data, carcinoembryonic antigen (CEA) values, observed toxicities, and information on prior therapies were collected. Response was assessed by RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 criteria. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method.ResultsTwenty-four patients (median age, 63 years) were included. Of the patients, 54% had extrahepatic disease; 67% had bilobar involvement. The patients had received a median of 3 prior therapies. No objective responses were observed. Five patients had a CEA response. Median PFS and OS were 3.9 months (95% CI, 2.4-4.8 months) and 8.9 months (95% CI, 4.2-16.7 months), respectively. Patients older than 65 years had improved PFS (4.6 vs. 2.4 months) and OS (14 vs. 5.5 months) vs. younger patients, likely due to receipt of 90Y treatment earlier in their disease course. The presence of extrahepatic disease and the absence of CEA response appeared negatively predictive of efficacy. Toxicities were expected and manageable.Conclusion90Y radioembolization is active in select patients with refractory mCRC and with liver metastases, and is safe and well tolerated in the elderly. In patients with extensive extrahepatic disease, 90Y should be used in combination with chemotherapy. CEA may be a predictor of efficacy.  相似文献   
9.
Nanobodies show attractive characteristics for tumor targeting in cancer diagnosis and therapy. A radiolabeled nanobody binding the prostate‐specific membrane antigen (PSMA) could offer a noninvasive strategy to select prostate cancer patients eligible for PSMA‐targeted therapies. We here describe the generation, production and in vivo evaluation of anti‐PSMA nanobodies. Nanobodies were derived from heavy‐chain‐only antibodies, raised in immunized dromedaries. Binding characteristics were evaluated through ELISA and flow cytometry. Selected nanobodies were radiolabeled with 99mTc at their hexahistidine tail, after which cell binding capacity and internalization were evaluated on PSMApos LNCaP and PSMAneg PC3 cell lines. In vivo tumor targeting was analyzed in both LNCaP and PC3 xenografted mice through SPECT/microCT and tissue sampling. A panel of 72 generated clones scored positive on ELISA, all contributing to three nanobody groups, of which group 3 dominated with 70 clones. ELISA and FACS analysis led to the selection of two dominant nanobodies. 99mTc‐labeled PSMA6 and PSMA30 both showed specific binding on LNCAP cells, but not on PC3 cells. 99mTc‐PSMA30 internalized significantly more in LNCaP cells compared to 99mTc‐PSMA6. Higher absolute tumor uptake and tumor‐to‐normal organ ratios were observed for 99mTc‐PSMA30 compared with 99mTc‐PSMA6 and a 99mTc‐control nanobody in LNCaP but not in PC3 tumor‐bearing mice. PSMA30 nanobody has improved targeting characteristics both in vitro as well as in vivo compared with PSMA6 and the control nanobody, and was therefore selected as our in‐house‐developed lead compound for PSMA targeting. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
10.
Aortocaval fistula (ACF) is a rare, life threatening complication of abdominal aortic aneurysms. Time to diagnosis is crucial as preoperative diagnosis and early surgical intervention significantly improve the outcome. The clinical spectrum being varied, the challenge of prompt and reliable diagnosis rests on emergency radiology. While the gold standard for detecting ACF today is CT angiography (CTA), frequently complicating renal insufficiency discourages the use of iodinated contrast making MR angiography (MRA) a useful alternative. Contrast enhanced ultrasound (CEUS) provides a promising new diagnostic option allowing rapid, non invasive and bedside diagnosis, especially in hemodynamically unstable patients. We present a case of prompt diagnosis of ACF by CEUS in comparison to modern MRA, thus establishing the new potential role of CEUS.  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