In situ detection of dopamine using nitrogen incorporated diamond nanowire electrode

[[abstract]]Significant difference was observed for the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA) mixture using nitrogen incorporated diamond nanowire (DNW) film electrodes grown by microwave plasma enhanced chemical vapor deposition. For the simultaneous sensing of ternary mixtures of DA, AA, and UA, well-separated voltammetric peaks are obtained using DNW film electrodes in differential pulse voltammetry (DPV) measurements. Remarkable signals in cyclic voltammetry responses to DA, AA and UA (three well defined voltammetric peaks at potentials around 235, 30, 367 mV for DA, AA and UA respectively) and prominent enhancement of the voltammetric sensitivity are observed at the DNW electrodes. In comparison to the DPV results of graphite, glassy carbon and boron doped diamond electrodes, the high electrochemical potential difference is achieved via the use of the DNW film electrodes which is essential for distinguishing the aforementioned analytes. The enhancement in EC properties is accounted for by increase in sp2 content, new C–N bonds at the diamond grains, and increase in the electrical conductivity at the grain boundary, as revealed by X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure measurements. Consequently, the DNW film electrodes provide a clear and efficient way for the selective detection of DA in the presence of AA and UA.[[booktype]]紙

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

複合態觸媒光催化降解四氯酚

本研究主要目的為針對水溶液中之目標降解物四氯酚（4-Cholorophenol），進行光催化常用半導體催化效率的改善。所採用的半導體光觸媒包括單一態二氧化鈦（TiO2）、二氧化錫（SnO2）和三氧化鎢（WO3）以及複合態TiO2/SnO2和TiO2/WO3。 實驗中除TiO2、SnO2和WO3為現購外， TiO2/SnO2和TiO2/WO3均分別由檸檬酸鹽法（Citric Acid Complexing Method）和初濕含浸法（Incipient Wetness Method）製成。隨後，在進行TiO2/SnO2、TiO2/WO3複合態光催化效率實驗的同時，亦將其複合態作物理上的性質分析，包括了UV-Vis、SEM、XRD、ESCA（XPS）、BET。 複合態之物性分析方面，TiO2/SnO2之臨界波長為380 nm，有分相傾向，Ti和Sn的元素分子含量比例為95.32 %：4.68 %，比表面積為12.4 m2/g ；TiO2/WO3為475 nm，無分相傾向，Ti和W的元素分子含量比例為75.95 %：24.05 %，比表面積為37.1 m2/g。 催化實驗結果，除了SnO2、TiO2/SnO2之外，其餘的催化降解效率均是在低pH值（pH＝4）條件下擁有較佳去除效果。在波長為369 nm之TiO2/SnO2這組中，以單一態TiO2表現最佳，pH4時降解效率約95 %，原因是波長為369 nm之燈管很容易激發TiO2，造成其催化效率特別顯著；波長為435 nm之TiO2/WO3方面，以複合態TiO2/WO3表現最佳，pH4時降解效率約有73 %。The objective of this study is to increase the photocatalytic activity of semiconductor photocatalysts for aqueous 4-Chlorophenol. These photocatalysts we used here were single titanium dioxide (TiO2), tin oxide (SnO2), tungsten oxide (WO3) and coupled TiO2/SnO2 and TiO2/WO3. TiO2/SnO2 was made by Citric Acid Complexing Method and TiO2/WO3 was made by Incipient Wetness Method. Through some specialized analytic equipments such as UV-Vis、SEM、XRD、ESCA (XPS) and BET, we could analyze these combined semiconductor photocatalysts in order to get the information of physical properties. In the results of physical analysis, the band edge wavelength of TiO2/SnO2 is 380 nm, Ti element : Sn element is 95.32 %:4.68 %, the surface area is 12.4 m2/g; the band edge wavelength of TiO2/WO3 is 475 nm, Ti element : W element is 75.95 %:24.05 %, the surface area is 37.1 m2/g. In the results of photocalysis, except single SnO2 and coupled TiO2/SnO2, higher photodegradation efficiency of 4-CP was observed at lower pH values. In TiO2/SnO2, UV369 nm system, single TiO2 owned the better degradation efficiency of 4-CP, it’s 95 % at pH4. For TiO2/WO3, UV435 nm system, coupled TiO2/WO3 owned the best degradation efficiency, it’s about 73 % at pH4.目錄 謝誌......I 摘要......II Abstract......III 目錄......IV 圖目錄......VII 表目錄......IX 第一章 緒論......1 1-1 前言......1 1-2 研究目的與內容......2 第二章 文獻回顧......4 2-1 光觸媒......4 2-2 二氧化鈦的物理和化學性質......4 2-2-1 構造及特性......4 2-2-2 應用......6 2-3 異相半導體光催化反應......6 2-3-1 半導體性質......6 2-3-2 異相半導體光催化反應之應用......8 2-3-3 半導體光催化之反應原理......9 2-3-3-1 能隙（Band gap）......10 2-3-3-2 能帶位置（Band-edge position）......11 2-3-3-3 電子電洞的捕捉效應（Scavenging）......13 2-3-3-4 表面競爭吸附（Competitive surface adsorption）......14 2-3-4 TiO2光催化反應......14 2-4 提升光活性的方法......15 2-4-1 添加重金屬......15 2-4-2 表面敏化（Surface sensitization）......16 2-4-3 過渡金屬之摻入（Transition metal doping）......16 2-4-4 複合半導體（Coupled semiconductor）......17 2-5 利用光觸媒去除污染物......20 2-6 氫氧自由基之測定......23 第三章 實驗材料與方法......24 3-1 研究項目......24 3-2 複合態光觸媒之製備......25 3-2-1 TiO2/SnO2之製備......25 3-2-2 TiO2/WO3之製備......27 3-2-3 光觸媒之物性分析......28 3-2-3-1 紫外-可見光光譜儀（UV-Vis Spectrum）......29 3-2-3-2 掃描式電子顯微鏡（SEM）......30 3-2-3-3 X-ray繞射分析（XRD）......30 3-2-3-4 化學分析影像能譜儀（ESCA（XPS））......30 3-2-3-5 比表面積測定（BET）......31 3-3 半導體光催化實驗......32 3-3-1 實驗流程......32 3-3-2 實驗設備......35 3-3-3 操作因子......36 3-3-4 光催化去除四氯酚......39 3-3-4-1 背景實驗......39 3-3-4-2 四氯酚之光催化分解實驗–基礎實驗......40 3-3-4-3 四氯酚之光催化分解實驗–進階實驗（一）（二）......40 3-3-5 分析分法......42 3-3-5-1 水溶液中四氯酚濃度分析......42 3-3-5-2 總有機碳（Total Organic Carbon, TOC）分析......43 3-3-5-3 氯離子之分析......43 第四章 結果與討論......45 4-1 光觸媒物化性質分析鑑定......45 4-1-1 UV-Vis spectrum分析......45 4-1-2 SEM ......48 4-1-3 XRD分析......50 4-1-4 ESCA（XPS）分析......53 4-1-5 BET分析......53 4-2 光催化背景實驗 ......54 4-2-1 揮發實驗......54 4-2-2 吸附實驗......55 4-2-3 直接光解實驗 ......58 4-3 四氯酚之光催化降解實驗......60 4-3-1 四氯酚之光催化降解實驗–基礎實驗......60 4-3-2 四氯酚之光催化降解實驗–進階實驗（一）......66 4-3-3 四氯酚之光催化降解實驗–進階實驗（二）......71 第五章 結論......73 5-1 結論......73 參考文獻......75 附錄......7