Formation polarity dependent improved resistive switching memory characteristics using nanoscale (1.3 nm) core-shell IrOx nano-dots

Improved resistive switching memory characteristics by controlling the formation polarity in an IrOx/Al2O3/IrOx-ND/Al2O3/WOx/W structure have been investigated. High density of 1 × 1013/cm2 and small size of 1.3 nm in diameter of the IrOx nano-dots (NDs) have been observed by high-resolution transmission electron microscopy. The IrOx-NDs, Al2O3, and WOx layers are confirmed by X-ray photo-electron spectroscopy. Capacitance-voltage hysteresis characteristics show higher charge-trapping density in the IrOx-ND memory as compared to the pure Al2O3 devices. This suggests that the IrOx-ND device has more defect sites than that of the pure Al2O3 devices. Stable resistive switching characteristics under positive formation polarity on the IrOx electrode are observed, and the conducting filament is controlled by oxygen ion migration toward the Al2O3/IrOx top electrode interface. The switching mechanism is explained schematically based on our resistive switching parameters. The resistive switching random access memory (ReRAM) devices under positive formation polarity have an applicable resistance ratio of > 10 after extrapolation of 10 years data retention at 85°C and a long read endurance of 105 cycles. A large memory size of > 60 Tbit/sq in. can be realized in future for ReRAM device application. This study is not only important for improving the resistive switching memory performance but also help design other nanoscale high-density nonvolatile memory in future

Increased COUP-TFII expression in adult hearts induces mitochondrial dysfunction resulting in heart failure

Mitochondrial dysfunction and metabolic remodelling are pivotal in the development of cardiomyopathy. Here, we show that myocardial COUP-TFII overexpression causes heart failure in mice, suggesting a causal effect of elevated COUP-TFII levels on development of dilated cardiomyopathy. COUP-TFII represses genes critical for mitochondrial electron transport chain enzyme activity, oxidative stress detoxification and mitochondrial dynamics, resulting in increased levels of reactive oxygen species and lower rates of oxygen consumption in mitochondria. COUP-TFII also suppresses the metabolic regulator PGC-1 network and decreases the expression of key glucose and lipid utilization genes, leading to a reduction in both glucose and oleate oxidation in the hearts. These data suggest that COUP-TFII affects mitochondrial function, impairs metabolic remodelling and has a key role in dilated cardiomyopathy. Last, COUP-TFII haploinsufficiency attenuates the progression of cardiac dilation and improves survival in a calcineurin transgenic mouse model, indicating that COUP-TFII may serve as a therapeutic target for the treatment of dilated cardiomyopathy

SARS Exposure and Emergency Department Workers

Of 193 emergency department workers exposed to severe acute respiratory syndrome (SARS), 9 (4.7%) were infected. Pneumonia developed in six workers, and assays showed anti-SARS immunoglobulin (Ig) M and IgG. The other three workers were IgM-positive and had lower IgG titers; in two, mild illness developed, and one remained asymptomatic

Clinical Efficacy and Post-Treatment Seromarkers Associated with the Risk of Hepatocellular Carcinoma among Chronic Hepatitis C Patients

This follow-up study enrolled chronic hepatitis C patients to evaluate the treatment efficacy and to identify post-treatment seromarkers associated with risk of hepatocellular carcinoma (HCC) among patients with a sustained virological response (SVR) or nonsustained virological response (NSVR). A total of 4639 patients who received pegylated interferon and ribavirin during 2004–2013 were followed until December 2014. HCC was confirmed through health examinations and data linkage with a national database. A total of 233 HCC cases were reported after 26,163 person-years of follow-up, indicating an incidence of 8.9 per 1000 person-years: 6.9 for SVR and 21.6 for NSVR per 1000 person-years. The associated risk of HCC in patients with SVR was 0.37 (0.22–0.63) for those without cirrhosis and 0.54 (0.31–0.92) for those with cirrhosis compared with their respective counterparts with NSVR. Among patients with SVR, advanced age, male gender, cirrhosis, decreased platelet count, and increased aspartate aminotransferase and α-fetoprotein levels were associated with HCC (p < 0.001). The treatment of chronic hepatitis C patients before they developed cirrhosis showed a higher efficacy than did the treatment of those who had already developed cirrhosis. Patients with SVR may still have a risk of HCC and need to be regularly monitored

Hepatitis D double reflex testing of all hepatitis B carriers in low-HBV- and high-HBV/HDV-prevalence countries

Hepatitis D virus (HDV) infection occurs as a coinfection with hepatitis B and increases the risk of hepatocellular carcinoma, decompensated cirrhosis, and mortality compared to hepatitis B virus (HBV) monoinfection. Reliable estimates of the prevalence of HDV infection and disease burden are essential to formulate strategies to find coinfected individuals more effectively and efficiently. The global prevalence of HBV infections was estimated to be 262,240,000 in 2021. Only 1,994,000 of the HBV infections were newly diagnosed in 2021, with more than half of the new diagnoses made in China. Our initial estimates indicated a much lower prevalence of HDV antibody (anti-HDV) and HDV RNA positivity than previously reported in published studies. Accurate estimates of HDV prevalence are needed. The most effective method to generate estimates of the prevalence of anti-HDV and HDV RNA positivity and to find undiagnosed individuals at the national level is to implement double reflex testing. This requires anti-HDV testing of all hepatitis B surface antigen-positive individuals and HDV RNA testing of all anti-HDV-positive individuals. This strategy is manageable for healthcare systems since the number of newly diagnosed HBV cases is low. At the global level, a comprehensive HDV screening strategy would require only 1,994,000 HDV antibody tests and less than 89,000 HDV PCR tests. Double reflex testing is the preferred strategy in countries with a low prevalence of HBV and those with a high prevalence of both HBV and HDV. For example, in the European Union and North America only 35,000 and 22,000 cases, respectively, will require anti-HDV testing annually

Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways

Study on the Characteristics of Steady Horseshoe Vortex System near the Juncture of a Vertical Plate and a Horizontal Bottom

本研究之目的旨在針對不同高寬比(aspect ratio, H/W)對直立式平板前緣穩定運動狀態馬蹄形渦流系統特性所造成之影響，進行深入分析探討。運用精密之PIV量測系統，可對於流場中長時間與瞬時全域流場之量測，使得原本未知的直立式平板前緣穩定運動狀態馬蹄形渦流流場特性能夠更加明瞭。 本文針對Re = 200 ~ 1200範圍內，深入探討H、W與δ三原始參數對於流場特性之影響，變化不同高寬比(H/W = 1 ~ 4)與δ(H/δ = 0.5 ~ 9, W/δ = 0.5 ~ 3)條件，分析馬蹄形渦流結構的特性變化，得到H/W、H/δ與W/δ三無因次參數對主渦渦心之水平與垂直位置、平板前緣中心軸面之下降流強度及停滯點的相關性。並對於流場結構以拓樸學理論進行渦流結構分析與其速度剖面探討。ABSTRACT The laminar boundary layer on the wall ahead of a vertical plate is in a region of adverse pressure gradient, and within some distance upstream of the body this boundary layer experiences a three-dimensional separation. In the separated region, a system of vortices is developed and stretched around the base of the body like a horseshoe shape. The characteristics of steady horseshoe vortex system near the juncture of a vertical plate and a horizontal bottom was studied experimentally using particle image velocimetry (PIV). The purpose of the present study is to provide Several detailed flow structures in the steady type, regarding the position of primary vortex core, down-flow velocity, and the position of stagnation point on the model are discussed. The range of aspect ratio (H/W) is from 1 to 4 for the Reynolds number Re, based upon the free stream velocity (U0 ) and the width of vertical plate (W), is form 200 to 1200.目 錄 誌 謝 Ⅰ 中文摘要 Ⅱ 英文摘要 Ⅲ 表 目 錄 Ⅵ 圖 目 錄 Ⅷ 相片目錄 ⅩⅢ 符號說明 ⅩⅤ 第一章 緒論 1-1 研究動機 1 1-2 相關文獻回顧 3 1-3 本文組織 10 第二章 實驗設備佈置及分析方法 2-1 實驗水槽及模型佈置 13 2-1-1 循環水槽 13 2-1-2 拖曳式平台 13 2-1-3 實驗模型 15 2-1-4 實驗佈置 15 2-1-5 實驗條件分佈. 18 2-2 流場可視化實驗佈置及方法 21 2-2-1 可視化實驗佈置 21 2-2-2 可視化實驗之追蹤物質(tracer) 23 2-3 FLDV量測系統及實驗佈置 23 2-3-1 二維FLDV系統 23 2-3-2 二維FLDV系統之佈置 26 2-3-3 實驗資料分析方法 26 2-4 PIV量測系統及實驗裝置 28 2-4-1 PIV量測系統 28 2-4-2 PIV之運作與計算原理 32 2-4-3 PIV量測系統之佈置 34 2-5 渦度分析與環流量計算 34 第三章ˉ初步實驗 3-1 平板邊界層平均速度剖面量測 37 3-2 流場壓力梯度檢測 37 3-3 邊界層發展檢測 39 3-4 平板流場Z方向二維性檢測 39 3-5 圓柱實驗印證 41 3-6 PIV量測實驗檢測 43 3-7 PIV系統於低流速下運作之檢測 45 3-8 玻璃與壓克力平板之相同性檢測 47 3-9 馬蹄型渦流流場之再現性檢測 52 第四章ˉ平板前緣穩定運動狀態馬蹄型渦流系統特性 之分析探討 4-1 各類穩定運動渦流系統之流場結構拓撲理論與速度剖面分析 55 4-1-1 二渦渦流結構系統 56 4-1-2 四渦渦流結構系統 56 4-1-3 六渦渦流結構系統 60 4-1-4 八渦渦流結構系統 ….60 4-2 主渦渦心位置變化分析探討……………………………65 4-2-1 主渦渦心之垂直位置變化分析探討 65 4-2-2 主渦渦心之垂直位置變化分析探討 82 4-3 直立式平板前緣中心軸面之下降流強度分析 85 4-4 停滯點之位置變化分析 88 第五章ˉ結論與建議 5-1 結論 90 5-2 建議 92 參考文獻 93 附 錄 9

Three New-naturalized Plants in Taiwan

Naturalization of three alien plants: Clinopodium brownei (Lamiaceae), Neptunia pubescens (Fabaceae) and Praxelis pauciflora (Asteraceae) in Taiwan were reported here. Description, line-drawing and relative information of these plants were presented, too

Characteristics of Flow Fields beneath Inundated Bridge Decks

一般非淹沒橋面條件下之河川水流乃屬重力流，惟當洪水位高過梁底、達至橋梁上部結構，形成橋面部份淹沒或完全淹沒流況時，則逐漸形成壓力流；此時對水流而言，上部結構形同一障礙物而窄縮通水斷面，造成上游側之水位抬升，乃自上游流入橋面版下方之水流流速逐漸增強，形成之下射式水流引致河床鉛垂向的束縮沖刷，進而促使橋基更加裸露。 本研究採用質點影像測速儀(PIV)量測系統與流場可視化方法，以穩態均勻流之定床水工模型實驗，模擬橋梁上部結構被洪水淹沒之情境，研究橋梁為洪流淹沒時之橋面版下方流場特性。 依據橋梁淹沒狀況與流場特性，淹沒橋梁之流況類型可分為：(1)部分淹沒橋梁與(2)完全淹沒橋梁，其中前者可再細分為：①潛沒孔口流況(Type I、Type II)；②過渡帶流況(Type III)；③閘孔流況(Type IV)；而後者則亦可細分為：①自由堰流流況(Type V)；②潛沒越流流況(Type VI)。 對於梁間穴槽內漩渦之運動特性，漩渦呈現逆時針或順時針旋轉方向(來流方向係由左方流至右方)的決定機制，係取決於橋下梁底區域之自第一根大梁前緣分離流之剪力層與最末根大梁下游端之尾跡流兩者的相對強度關係。若流況以前緣之分離流剪力層為主時，則漩渦呈現逆時針方向旋轉為主；而當流場受最末根大梁下游端之尾跡流影響時，因部分水流逆流，乃呈現漩渦以逆時針方向旋轉為主。 就不同類型之淹沒流況(Type I ~ Type VI)下，以來流之福祿數、梁底淨高係數、梁間穴槽之氣袋係數及不同橋梁模型(三梁、四梁、矩型、箱型梁)等無因次參數，作為實驗控制變數，採用Lin et al. (2008)就單階自由跌水流況所提出之相似性分析方法，分別以剪力層特徵厚度bs(= ysu -ysl)為特徵長度、特徵厚度之上下層速度差(usl - usu)為特徵速度，作為水平平均速度剖面之特徵值參數，結果顯示橋面版下方的梁底剪力層具有共同之水平速度剖面相似性。During the flood peak of a certain typhoon in Taiwan, the water level in the rivers continuously rises. The bridges in the upstream or middle reach experience the gradual increase in water level, and then get submerged either partially or totally. Such inundated bridges will be subjected to a combined effect of pressure flow below the bridge deck and the weir flow over the bridge depending upon the water level of the approaching flow relative to the headroom clearance below the bridge deck. In order to investigate such kinds of flow field under a relatively idealized situation without the effect of bed scour, hydraulic model tests with rigid bed were carried out in a re-circulating flume with dimensions of 446 cm long, 50 cm high and 25 cm wide. The test section was fitted with glass-sided walls and glass bottom to facilitate optical access and was located at 150 cm from the inlet of the flume. Flow visualization and PIV techniques were used to observe and measure the flow field, respectively. The characteristics of shear layer structure in the flow under partially and fully inundated bridge decks, in which the cavities between girders are partially and fully occupied by air-pocket, are mainly investigated. The main parameters that dominate the flow field are Froude number Fr of the approaching flow, the proximity ratio Pr (= ratio of clearance below the bridge deck h to the total depth of deck D), the inundation (relative submergence) ratio Sr (= ratio of the depth of water over the low chord of the bridge deck (H1 – h) to the total depth of deck D), and the ratio of the depth of air-pocket to the depth of girder cavity, Ra. Depending upon the Froude number Fr, proximity ratio Pr , inundation ratio Sr , and relative cavity ratio Ra, different types of flow structures under the bridge decks can be classified. Moreover, the characteristics of vortex structure under partially and fully inundated bridge deck, which inside the cavities between girders are full of water (i.e. without air-pocket), was investigated. The similarity profile of vortex core for the azimuthal velocity at different radial distances was obtained using the measured azimuthal velocities for flow Type I and Type II cases. In addition, the nonlinear regression equations are developed for the vertical distribution of mean streamwise velocity in the shear layer below bridge deck, Using the distributions of measured mean streamwise velocity within the shear layer below the bridge deck at different streamwise distances, the similarity profile is obtained. The mean velocity deficit (usl – usu) and representative thickness bs are considered as the appropriate characteristic velocity and length scales for developing similarity profile. The proposed characteristic scales provided unique similarity profiles having promising regression coefficient. It is believed that these data provided in this study facilitate the researchers in numerical modeling and also enhance the knowledge of flow phenomenon.摘 要 I ABSTRACT II 目 錄 III 表 目 錄 VI 圖 目 錄 VII 相片目錄 XIV 符號說明 XV 第一章 緒論 1-1 研究動機 1 1-2 文獻回顧 2 1-3 本文組織 9 第二章 實驗設備、方法與布置 2-1 實驗設備 10 2-1-1 實驗水槽 10 2-1-2 高速攝影機 10 2-1-3 光源系統 11 2-1-4 流場追蹤物質 11 2-1-5 三維移動平臺 12 2-2 實驗方法與布置 12 2-2-1 流場可視化方法 12 2-2-2 質點影像測速儀量測系統 13 2-2-3 橋梁模型與實驗布置 14 2-2-4 影像視野劃分 14 第三章 相關實驗條件與初步實驗 3-1 流場座標系統、因次分析與實驗條件 22 3-1-1 流場座標系統 22 3-1-2 因次分析與實驗條件 23 3-2 均勻來流檢測 31 第四章 淹沒橋梁之流況型態與橋面版下方之平均速度場特性 4-1 部分淹沒及完全淹沒橋梁之流況型態系統化分類 32 4-2 部分淹沒之潛沒孔口流況下之橋面版下方速度場特性 50 4-2-1 梁間穴槽充滿水體(無氣袋) 50 4-2-2 梁間穴槽存在部分氣袋或充滿氣袋 54 4-3 部分淹沒之過渡帶流況下之橋面版下方速度場特性 64 4-4 部分淹沒之閘孔流況下之橋面版下方速度場特性 77 4-5 完全淹沒之自由堰流流況下之橋面版下方速度場特性 83 4-5-1 梁間穴槽充滿水體(無氣袋) 83 4-5-2 梁間穴槽存在部分氣袋或充滿氣袋 92 4-6 完全淹沒之潛沒越流流況下之橋面版下方速度場特性 102 4-7小結 110 第五章 梁間穴槽之漩渦特性與速度剖面相似性 5-1 部分淹沒流況下之梁間穴槽漩渦特性 112 5-2 完全淹沒流況下之梁間穴槽漩渦特性 116 5-3 部分淹沒流況下之漩渦環向速度剖面相似性分析 120 5-4 小結 130 第六章 梁底下方之剪力層速度剖面相似性分析與特性研析 6-1 部分淹沒之潛沒孔口流況(一)—梁間穴槽充滿水體(無氣袋) 132 6-2 部分淹沒之潛沒孔口流況(二)—梁間穴槽存在部分氣袋或充滿氣袋 142 6-3 部分淹沒之過渡帶流況 147 6-4 部分淹沒之閘孔流況 149 6-5 完全淹沒之自由堰流流況 152 6-6 完全淹沒之潛沒越流流況 154 6-7 梁底下方之剪力層的水平速度剖面特性研析 156 6-8 小結 165 第七章 結論與建議 7-1 結論 169 7-2 建議 172 參考文獻 173 附錄A 梁底下方之剪力層的速度剖面最適化曲線之各迴歸係數與特徵值 A-1 附錄B 論文口試審查意見回覆表 B-