Design, fabrication and characterization of monolithic embedded parylene microchannels in silicon substrate

This paper presents a novel channel fabrication technology of bulk-micromachined monolithic embedded polymer channels in silicon substrate. The fabrication process favorably obviates the need for sacrifical materials in surface-micromachined channels and wafer-bonding in conventional bulk-micromachined channels. Single-layer-deposited parylene C (poly-para-xylylene C) is selected as a structural material in the microfabricated channels/columns to conduct life science research. High pressure capacity can be obtained in these channels by the assistance of silicon substrate support to meet the needs of high-pressure loading conditions in microfluidic applications. The fabrication technology is completely compatible with further lithographic CMOS/MEMS processes, which enables the fabricated embedded structures to be totally integrated with on-chip micro/nano-sensors/actuators/structures for miniaturized lab-on-a-chip systems. An exemplary process was described to show the feasibility of combining bulk micromachining and surface micromachining techniques in process integration. Embedded channels in versatile cross-section profile designs have been fabricated and characterized to demonstrate their capabilities for various applications. A quasi-hemi-circular-shaped embedded parylene channel has been fabricated and verified to withstand inner pressure loadings higher than 1000 psi without failure for micro-high performance liquid chromatography (µHPLC) analysis. Fabrication of a high-aspect-ratio (internal channel height/internal channel width, greater than 20) quasi-rectangular-shaped embedded parylene channel has also been presented and characterized. Its implementation in a single-mask spiral parylene column longer than 1.1 m in a 3.3 mm × 3.3 mm square size on a chip has been demonstrated for prospective micro-gas chromatography (µGC) and high-density, high-efficiency separations. This proposed monolithic embedded channel technology can be extensively implemented to fabricate microchannels/columns in high-pressure microfludics and high-performance/high-throughput chip-based micro total analysis systems (µTAS)

V2PSense: Enabling Cellular-based V2P Collision Warning Service Through Mobile Sensing

The C-V2X (Cellular Vehicle-to-Everything) technology is developing in full swing. One of its mainstream services can be the Vehicle-to-Pedestrian (V2P) service. It can protect pedestrians who are mostly vulnerable on the road. In this work, we seek to enable a V2P service that can identify which pedestrians may be nearby a dangerous driving event and then notify them of warning messages. To enable this V2P service, there are two major challenges. First, a low-latency V2P message transport is required for this infrastructure-based service. Second, the pedestrian’s smartphone requires an energy-efficient outdoor positioning method instead of power-hungry GPS due to its limited battery life. We thus propose a novel solution, V2PSense, which trades off positioning precision for energy savings while achieving low-latency message transport with LTE high-priority bearers. It does a coarse-grained positioning by leveraging intermittent GPS information and mobile sensing data, which includes step count from the pedometer and cellular signal strength changes. Though the V2PSense’s positioning is not as precise as the GPS, it can still ensure that all the pedestrians nearby dangerous spots can be notified. Our results show that it can achieve the average precision ratio 92.6% for estimating where the pedestrian is while saving 20.8% energy, compared with the GPS always-on case.This work was partially supported by the Ministry of Science and Tech-nology, Taiwan, under grant numbers 106-2622-8-009-017 and 106-2218-E-009-018, and by the H2020 collaborative Europe/Taiwan research project 5G-CORAL (grant num. 761586

Mobile Edge Computing Platform Deployment in 4G LTE Networks: A Middlebox Approach

This paper has been presented at : USENIX Workshop on Hot Topics in Edge Computing (Hot Edge '18)Low-latency demands for cellular networks have at-tracted much attention. Mobile edge computing (MEC), which deploys a cloud computing platform at the edge closer to mobile users, has been introduced as an enabler of low-latency performance in 4G and 5G networks. In this paper, we propose an MEC platform deployment so-lution in 4G LTE networks using a middlebox approach. It is standard-compliant and transparent to existing cel-lular network components, so they need not be modified. The MEC middlebox sits on the S1 interface, which con-nects an LTE base station to its core network, and does traffic filtering, manipulation and forwarding. It enables the MEC service for mobile users by hosting application servers. Such middlebox approach can save deployment cost and be easy to install. It is different from other stud-ies that require modifications on base stations or/and core networks. We have confirmed its viability through a pro-totype based on the OpenAirInterface cellular platform.We thank our shepherd Weisong Shi for his help, and also thank the anonymous reviewers for their valuable comments on improving this paper. This work was partially supported by the Ministry of Science and Technology, Taiwan, under grant numbers 106-2622-8-009-017 and 106-2218-E-009-018, and by the H2020 collaborative Europe/Taiwan research project 5G-CORAL (grant number 761586)

Chronic hepatitis virus infection in patients with multiple myeloma: clinical characteristics and outcomes

OBJECTIVES: Cytotoxic agents and steroids are used to treat lymphoid malignancies, but these compounds may exacerbate chronic viral hepatitis. For patients with multiple myeloma, the impact of preexisting hepatitis virus infection is unclear. The aim of this study is to explore the characteristics and outcomes of myeloma patients with chronic hepatitis virus infection. METHODS: From 2003 to 2008, 155 myeloma patients were examined to determine their chronic hepatitis virus infection statuses using serologic tests for the hepatitis B (HBV) and C viruses (HCV). Clinical parameters and outcome variables were retrieved via a medical chart review. RESULTS: The estimated prevalences of chronic HBV and HCV infections were 11.0% (n = 17) and 9.0% (n = 14), respectively. The characteristics of patients who were hepatitis virus carriers and those who were not were similar. However, carrier patients had a higher prevalence of conventional cytogenetic abnormalities (64.3% vs. 25.0%). The cumulative incidences of grade 3-4 elevation of the level of alanine transaminase, 30.0% vs. 12.0%, and hyperbilirubinemia, 20.0% vs. 1.6%, were higher in carriers as well. In a Kaplan-Meier analysis, carrier patients had worse overall survival (median: 16.0 vs. 42.4 months). The prognostic value of carrier status was not statistically significant in the multivariate analysis, but an age of more than 65 years old, the presence of cytogenetic abnormalities, a beta-2-microglobulin level of more than 3.5 mg/L, and a serum creatinine level of more than 2 mg/ dL were independent factors associated with poor prognosis. CONCLUSION: Myeloma patients with chronic hepatitis virus infections might be a distinct subgroup, and close monitoring of hepatic adverse events should be mandatory

Insights on Distinct Left Atrial Remodeling Between Atrial Fibrillation and Heart Failure With Preserved Ejection Fraction

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) commonly coexist with overlapping pathophysiology like left atrial (LA) remodeling, which might differ given different underlying mechanisms. OBJECTIVES: We sought to investigate the different patterns of LA wall remodeling in AF vs. HFpEF. METHODS: We compared LA wall characteristics including wall volume (LAWV), wall thickness (LAWT), and wall thickness heterogeneity (LAWT[SD]) and LA structure, function among the controls (without AF or HFpEF, n = 115), HFpEF alone (n = 59), AF alone (n = 37), and HFpEF+AF (n = 38) groups using multi-detector computed tomography and echocardiography. RESULTS: LA wall remodeling was most predominant and peak atrial longitudinal strain (PALS) was worst in HFpEF+AF patients as compared to the rest. Despite lower E/e' (9.8 ± 3.8 vs. 13.4 ± 6.4) yet comparable LA volume, LAWT and PALS in AF alone vs. HFpEF alone, LAWV [12.6 (11.6–15.3) vs. 12.0 (10.2–13.7); p = 0.01] and LAWT(SD) [0.68 (0.61–0.71) vs. 0.60 (0.56–0.65); p < 0.001] were significantly greater in AF alone vs. HFpEF alone even after multi-variate adjustment and propensity matching. After excluding the HFpEF+AF group, both LAWV and LAWT [SD] provided incremental values when added to PALS or LAVi (all p for net reclassification improvement <0.05) in discriminating AF alone, with LAWT[SD] yielding the largest C-statistic (0.78, 95% CI: 0.70–0.86) among all LA wall indices. CONCLUSIONS: Despite a similar extent of LA enlargement and dysfunction in HFpEF vs. AF alone, larger LAWV and LAWT [SD] can distinguish AF from HFpEF alone, suggesting the distinct underlying pathophysiological mechanism of LA remodeling in AF vs. HFpEF

Insights on Distinct Left Atrial Remodeling Between Atrial Fibrillation and Heart Failure With Preserved Ejection Fraction

Background: Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) commonly coexist with overlapping pathophysiology like left atrial (LA) remodeling, which might differ given different underlying mechanisms. Objectives: We sought to investigate the different patterns of LA wall remodeling in AF vs. HFpEF. Methods: We compared LA wall characteristics including wall volume (LAWV), wall thickness (LAWT), and wall thickness heterogeneity (LAWT[SD]) and LA structure, function among the controls (without AF or HFpEF, n = 115), HFpEF alone (n = 59), AF alone (n = 37), and HFpEF+AF (n = 38) groups using multi-detector computed tomography and echocardiography. Results: LA wall remodeling was most predominant and peak atrial longitudinal strain (PALS) was worst in HFpEF+AF patients as compared to the rest. Despite lower E/e' (9.8 ± 3.8 vs. 13.4 ± 6.4) yet comparable LA volume, LAWT and PALS in AF alone vs. HFpEF alone, LAWV [12.6 (11.6–15.3) vs. 12.0 (10.2–13.7); p = 0.01] and LAWT(SD) [0.68 (0.61–0.71) vs. 0.60 (0.56–0.65); p &lt; 0.001] were significantly greater in AF alone vs. HFpEF alone even after multi-variate adjustment and propensity matching. After excluding the HFpEF+AF group, both LAWV and LAWT [SD] provided incremental values when added to PALS or LAVi (all p for net reclassification improvement &lt;0.05) in discriminating AF alone, with LAWT[SD] yielding the largest C-statistic (0.78, 95% CI: 0.70–0.86) among all LA wall indices. Conclusions: Despite a similar extent of LA enlargement and dysfunction in HFpEF vs. AF alone, larger LAWV and LAWT [SD] can distinguish AF from HFpEF alone, suggesting the distinct underlying pathophysiological mechanism of LA remodeling in AF vs. HFpEF.</p

The Application of Borehole Hydrogeological Investigation for Assessing Landslide Susceptibility

On the basis of 49 borehole studies at the mid- and upper-stream of the Dajia and Jhuoshuei river basins, landslide occurrence was found to not only be related to subsurface geological composition and hydrogeological characteristics, but also to groundwater level dynamics, which have seldom been addressed in previous works. It is suggested that the interplay between hydrogeologic and landslide factors be given further consideration in future investigations. This would be a crucial step towards effective disaster prevention for mountainous regions in Taiwan.本研究主要係嘗試透過孔內水文地質調查結果，評估大甲溪與濁水溪流域地表下岩層的地質材料特性、水力特性、地下水與集水區山崩潛勢之關聯性。過去研究較少針對崩塌地進行現地水文地質調查與試驗，本研究根據49處試驗場址成果顯示，水文地質特性與山崩的潛勢、滑動深度，以及地下水位有一定程度之關聯性。本研究建議進行調查區域的水文地質特性，以及各促崩因子所造成的山崩的易損性，係各類型山崩災害分析與潛勢評估之重要的研究各題，亦可提供相關台灣災害防治之參考