Controlled Heterogeneous Nucleation and Growth of Germanium Quantum Dots on Nanopatterned Silicon Dioxide and Silicon Nitride Substrates

Controlled heterogeneous nucleation and growth of Ge quantum dots (QDs) are demonstrated on SiO_2/Si_3N_4 substrates by means of a novel fabrication process of thermally oxidizing nanopatterned SiGe layers. The otherwise random self-assembly process for QDs is shown to be strongly influenced by the nanopatterning in determining both the location and size of the QDs. Ostwald ripening processes are observed under further annealing at the oxidation temperature. Both nanopattern oxidation and Ostwald ripening offer additional mechanisms for lithography for controlling the size and placement of the QDs

Stationary Light Pulses in Cold Atomic Media

Stationary light pulses (SLPs), i.e., light pulses without motion, are formed via the retrieval of stored probe pulses with two counter-propagating coupling fields. We show that there exist non-negligible hybrid Raman excitations in media of cold atoms that prohibit the SLP formation. We experimentally demonstrate a method to suppress these Raman excitations and realize SLPs in laser-cooled atoms. Our work opens the way to SLP studies in cold as well as in stationary atoms and provides a new avenue to low-light-level nonlinear optics.Comment: 4 pages, 4 figure

Activation of Endothelial Cells by Antiphospholipid Antibodies—A Possible Mechanism Triggering Thrombosis in Patients with Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is an antibody-mediated hypercoagulable state characterized by recurrent venous and arterial thromboembolic events. The presence of serum antibodies are collectively termed as antiphospholipid antibodies (aPL) and is the hallmark of the disease. Interest in the pathogenesis has mostly been focused on the blood coagulation factor. However, endothelial cells might play an important role. When stimulated, cell membrane would flip to expose negatively charged phospholipids and activation markers such as adhesive molecules may appear. We consider that these changes may play an important role in the initiation of the thrombotic process when endothelial cells encounter aPL. In this study, we incubated human umbilical vein endothelial cells (HUVECs) with IgG isolated from patients with APS and found that the HUVECs were activated by the expression of negatively charged phospholipids, as shown by high annexin V binding and negative propidium iodide staining and by an increase in the level of intracellular cell adhesion molecule-1 on the cell surface. The above findings indicate that endothelial cells can be activated on exposure to aPL and trigger the thrombotic event

Toward Inter-Connection on OpenFlow Research Networks

With the advance of Future Internet technologies, many research issues andideas are growing fast in recent years. In the field of network virtualization, softwaredefined network becomes a common topic on network research. In Taiwan, manyinstitutes and laboratories of universities already built their bench-scale testbed forresearch and educational use with OpenFlow protocol. As time goes by, stitchingexperimental networks is a growing trend to fulfill requirements for large scaleemulation. Hence, this paper revealed a progressing deployment which connectsdifferent experimental networks with centralized control policy. The objective is tobuild an integrated research network with a proposed solution which utilizesOpenFlow protocol to deal with the inter-connections. With a centralized controllerand implemented architecture, the deployment not only solves the limitation of VLANtag number in network but also improves the flexibility of configuration. This designcould be a solution for the realistic constraints of network environment in Taiwan, andit also supports the possibility of stitching regional experimental networks fornetworking research

The Incremental Diagnostic Performance of Coronary Computed Tomography Angiography Added to Myocardial Perfusion Imaging in Patients with Intermediate-to-High Cardiovascular Risk

Purpose: Several studies have suggested that a combined approach of stress myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) can provide diagnostic results with excellent accuracy. We aimed to explore whether the addition of CCTA to stress MPI provides incremental diagnostic value in intermediate-to-high cardiovascular risk patients. Methods: A total of 106 consecutive patients (93 male, 65 ± 10.4 years) underwent coronary artery calcium scoring (CACS), CCTA and 201 Thallium stress MPI before coronary angiography was reviewed. Thirty-seven patients (34.9%) had a history of proven coronary artery disease (CAD) or revascularization procedures, and four had documented non-significant CAD (3.8%). The remaining patients consisted of 17 (16.0%) classified as intermediate, and 48 (45.3%) as the high-risk groups. Results: Obstructive CAD was diagnosed by invasive coronary angiography in 88 patients with 161 vessels. The sensitivity and specificity in a patient-based analysis for obstructive CAD were 99% and 17% for CCTA, 80% and 50% for MPI and 91% and 67% for the combined method, respectively. The per-vessel diagnostic sensitivity and specificity were 95% and 54% for CCTA, 59% and 75% for MPI and 84% and 76% for the combined method. There were significant differences (p < 0.05) when comparing the combined method with MPI or CCTA by areas under the curve in a patient-or vessel-based analysis. However, CACS of 400 or more could not further stratify the patients with obstructive CAD. Conclusions: CCTA, not CACS, provided additional diagnostic values to stress MPI in patients with intermediateto-high cardiovascular risk

Tequila Regulates Insulin-Like Signaling and Extends Life Span in Drosophila melanogaster

The aging process is a universal phenomenon shared by all living organisms. The identification of longevity genes is important in that the study of these genes is likely to yield significant insights into human senescence. In this study, we have identified Tequila as a novel candidate gene involved in the regulation of longevity in Drosophila melanogaster. We have found that a hypomorphic mutation of Tequila (Teq(f01792)), as well as cell-specific downregulation of Tequila in insulin-producing neurons of the fly, significantly extends life span. Tequila deficiency-induced life-span extension is likely to be associated with reduced insulin-like signaling, because Tequila mutant flies display several common phenotypes of insulin dysregulation, including reduced circulating Drosophila insulin-like peptide 2 (Dilp2), reduced Akt phosphorylation, reduced body size, and altered glucose homeostasis. These observations suggest that Tequila may confer life-span extension by acting as a modulator of Drosophila insulin-like signaling

Insights into Chinese perspectives on do-not-resuscitate (DNR) orders from an examination of DNR order form completeness for cancer patients

PURPOSE: Discussing end-of-life care with patients is often considered taboo, and signing a do-not-resuscitate (DNR) order is difficult for most patients, especially in Chinese culture. This study investigated distributions and details related to the signing of DNR orders, as well as the completeness of various DNR order forms. METHODS: Retrospective chart reviews were performed. We screened all charts from a teaching hospital in Taiwan for patients who died of cancer during the period from January 2010 to December 2011. A total of 829 patient records were included in the analysis. The details of the DNR order forms were recorded. RESULTS: The DNR order signing rate was 99.8 %. The percentage of DNR orders signed by patients themselves (DNR-P) was 22.6 %, while the percentage of orders signed by surrogates (DNR-S) was 77.2 %. The percentage of signed DNR forms that were completely filled out was 78.4 %. The percentage of DNR-S forms that were completed was 81.7 %, while the percentage of DNR-P forms that were completely filled out was only 67.6 %. CONCLUSION: Almost all the cancer patients had a signed DNR order, but for the majority of them, the order was signed by a surrogate. Negative attitudes of discussing death from medical professionals and/or the family members of patients may account for the higher number of signed DNR-S orders than DNR-P orders. Moreover, early obtainment of signed DNR orders should be sought, as getting the orders earlier could promote the quality of end-of-life care, especially in non-oncology wards