458 research outputs found

    Directed diffraction without negative refraction

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    Using the FDTD method, we investigate the electromagnetic propagation in two-dimensional photonic crystals, formed by parallel air cylinders in a dielectric medium. The corresponding frequency band structure is computed using the standard plane-wave expansion method. It is shown that within partial bandgaps, waves tend to bend away from the forbidden directions. This phenomenon perhaps need not be explained in terms of negative refraction or `superlensing' behavior, contrast to what has been conjectured.Comment: 3 pages, 4 figure

    Safety and Efficacy of Tien-Hsien Liquid Practical in Patients with Refractory Metastatic Breast Cancer: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Phase IIa Trial

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    To evaluate the safety and efficacy of Tien-Hsien Liquid Practical (THL-P), a Chinese herbal mixture, in patients with refractory metastatic breast cancer, we performed a randomized, double-blind, placebo-controlled, parallel-group, phase IIa pilot trial. Patients were randomly assigned to either receive THL-P or matching placebo and followed up every 4 weeks for 24 weeks. The primary endpoint was changes in the global health status/quality of life (GHS/QOL) scale. The secondary endpoints were changes in functional and symptom scales, immunomodulating effects, and adverse events. Sixty-three patients were enrolled between June 2009 and June 2011. The intent-to-treat population included 28 patients in the THL-P group and 11 patients in the placebo group. Compared to the placebo group, the THL-P group had significant improvement from baseline to last visit in GHS/QOL (41.7 versus −33.3; P < 0.05), CD3, CD4/CD8, CD19, CD16+56 positive cells (P < 0.05), and higher levels of physical, role, emotional, and cognitive functioning, as well as decreased fatigue and systemic side effects. Treatment-related adverse events were mild constipation and localized itching, and no serious adverse events were reported. THL-P appears to be a safe alternative adjuvant treatment for patients with refractory metastatic breast cancer, as it effectively improves QOL and palliates cancer-related symptoms

    Uniformly Distributed Graphene Domain Grows on Standing Copper via Low-Pressure Chemical Vapor Deposition

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    Uniformly distributed graphene domains were synthesized on standing copper foil by a low-pressure chemical vapor deposition system. This method improved the distribution of the graphene domains at different positions on the same piece of copper foil along the forward direction of the gas flow. Scanning electron microscopy (SEM) showed the average size of the graphene domains to be about ~20 m. This results show that the sheet resistance of monolayer graphene on a polyethylene terephthalate (PET) substrate is about ~359 /□ whereas that of the four-layer graphene films is about ~178 /□, with a transmittance value of 88.86% at the 550 nm wavelength. Furthermore, the sheet resistance can be reduced with the addition of HNO3 resulting in a value of 84 /□. These values meet the absolute standard for touch sensor applications, so we believe that this method can be a candidate for some transparent conductive electrode applications

    The Potential Utility of Curcumin in the Treatment of HER-2-Overexpressed Breast Cancer: An In Vitro and In Vivo Comparison Study with Herceptin

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    HER-2 is an important oncoprotein overexpressed in about 15–25% of breast cancers. We hypothesized that the ability of curcumin to downregulate HER-2 oncoprotein and inhibit the signal transduction pathway of PI3K/Akt, MAPK, and NF-κB activation may be important in the treatment of HER-2-overexpressed breast cancer. To examine the effect of curcumin on breast cancer cells, MCF-7, MDA-MB-231, MCF-10A, BT-474, and SK-BR-3-hr (a herceptin resistant strain from SK-BR-3) cells were used for in vitro analysis. The in vivo effect of curcumin on HER-2-overexpressed breast cancer was investigated with the HER-2-overexpressed BT-474 xenograft model. Cell growth, cell cycle change, the antimobility effect, signal transduction, and xenograft volume analysis between groups treated with herceptin and/or curcumin were tested. Curcumin decreased the cell growth of various breast cancer cell lines (MCF-7, MDA-MB-231, MCF-10A, BT-474, and SK-BR-3-hr). In Western blot analysis, the phosphorylation of Akt, MAPK, and expression of NF-κB were reduced in BT-474 cells, but not in SK-BR-3-hr cells, after treatment with herceptin. When treated with curcumin, the HER-2 oncoprotein, phosphorylation of Akt, MAPK and expression of NF-κB were decreased in both BT-474 and SK-BR-3-hr cells. In the BT-474 xenograft model, though not as much as herceptin, curcumin did effectively decrease the tumor size. The combination of curcumin with herceptin was not better than herceptin alone; however, the combination of taxol and curcumin had an antitumor effect comparable with taxol and herceptin. The results suggested that curcumin has potential as a treatment for HER-2-overexpressed breast cancer

    Effect of Supplementation of Tanshinone IIA and Sodium Tanshinone IIA Sulfonate on the Anticancer Effect of Epirubicin: An In Vitro Study

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    Tanshinone IIA (Tan IIA) and sodium tanshinone IIA sulfonate (STS) were found to have protective effects on cardiomyocyte against adriamycin-induced damage and may be used clinically. It is unclear whether the supplementation of STS or Tan IIA would affect the anticancer activity of anthracycline. To evaluate the effect of Tan IIA or STS on the anticancer of epirubicin, the cell viability, apoptosis, Akt expression, and uptake of epirubicin after supplementation of Tan IIA or STS in the epirubicin-treated BT-20 cells were measured and compared. Tan IIA inhibited BT-20 cell growth and induced apoptosis in a time- and dose-dependent manner. When Tan IIA was used with epirubicin, an increase of BT-20 cells apoptosis was accompanied by the decreasing phosphorylation of Akt. STS had no effect on the cell viability of BT-20 cells. However, when used with epirubicin, STS decreased the epirubicin-induced cytotoxicity and apoptosis in BT-20 cells. The antagonistic effect of STS on epirubicin-induced cytotoxicity in BT-20 cells occurred concomitantly with the reduced epirubicin uptake and the increased phosphorylation of Akt. STS decreased the uptake of epirubicin in BT-20 cells and blocked epirubicin-induced apoptosis through activation of Akt

    Efficacy of the visual cognitive assessment test for mild cognitive impairment/mild dementia diagnosis: a meta-analysis

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    BackgroundMild cognitive impairment (MCI) is an intermediate stage between normal ageing and dementia. The early identification of MCI is important for timely intervention. The visual cognitive assessment test (VCAT) is a brief language-neutral screening tool for detecting MCI/mild dementia. This meta-analysis evaluated the diagnostic efficacy of the VCAT for MCI/mild dementia.MethodsMedline, Embase, Google Scholar, and Cochrane Library were searched from their inception until August 2023 to identify studies using VCAT to diagnose MCI/mild dementia. The primary outcome was to assess the diagnostic accuracy of the VCAT for detecting MCI/mild dementia through area under the receiver operating characteristic curve (AU-ROC) analysis. The secondary outcome was to explore the correlation between VCAT scores and MCI/mild dementia presence by comparing scores among patients with and without MCI/mild dementia. Pooled sensitivity, specificity, and area under the curve (AUC) were calculated.ResultsFive studies with 1,446 older adults (mean age 64–68.3 years) were included. The percentage of participants with MCI/mild dementia versus controls ranged from 16.5% to 87% across studies. All studies were conducted in Asian populations, mostly Chinese, in Singapore and Malaysia. The pooled sensitivity was 80% [95% confidence interval (CI) 68%–88%] and the specificity was 75% (95% CI 68%–80%). The AU-ROCC was 0.77 (95% CI 0.73–0.81). Patients with MCI/mild dementia had lower VCAT scores than the controls (mean difference −6.85 points, p &lt; 0.00001).ConclusionVCAT demonstrated acceptable diagnostic accuracy in distinguishing MCI/mild dementia in cognitively normal older adults. As a language-neutral and culturally unbiased tool, the VCAT shows promise in detecting MCI/mild dementia. Further studies in non-Asian populations are required.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier: CRD42023453453

    The Effect of Annealing on Nanothick Indium Tin Oxide Transparent Conductive Films for Touch Sensors

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    This study aims to discuss the sheet resistance of ultrathin indium tin oxide (ITO) transparent conductive films during the postannealing treatment. The thickness of the ultrathin ITO films is 20 nm. They are prepared on B270 glass substrates at room temperature by a direct-current pulsed magnetron sputtering system. Ultrathin ITO films with high sheet resistance are commonly used for touch panel applications. As the annealing temperature is increased, the structure of the ultrathin ITO film changes from amorphous to polycrystalline. The crystalline of ultrathin ITO films becomes stronger with an increase of annealing temperature, which further leads to the effect of enhanced Hall mobility. A postannealing treatment in an atmosphere can enhance the optical transmittance owing to the filling of oxygen vacancies, but the sheet resistance rises sharply. However, a higher annealing temperature, above 250°C, results in a decrease in the sheet resistance of ultrathin ITO films, because more Sn ions become an effective dopant. An optimum sheet resistance of 336 Ω/sqr was obtained for ultrathin ITO films at 400°C with an average optical transmittance of 86.8% for touch sensor applications
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