Precise coulometric determination of redox inert anions based on electrolysis at the aqueous|organic solution interface

The flow cell proposed previously for the rapid and coulometric determination of cations based on the electrochemical ion transfer at the aqueous|organic solution interface was improved to be applicable to the determination of anions. The developed cell was composed of a porous poly(tetrafluoroethylene) tube (1.0 mm in inner diameter), a copper wire (0.8 mm in diameter) inserted into the tube, a platinum wire placed outside the tube, an organic solution into which the tube was immersed and a reference electrode in the organic solution. The aqueous solution containing a species of interest was flowed through the narrow gap between the tube and the copper wire. A potential difference was applied at the aqueous|organic solution interface by using the copper wire and the reference electrode in the organic solution in order to realize the ion transfer at the interface, and the current due to the interfacial ion transfer was detected by the copper and platinum wires. The developed cell was evaluated adopting the transfer of an anion such as perchlorate, picrate or alkylsulphonates from the aqueous solution to 1,2-dichloroethane (used as the organic solution), and demonstrated that the anions of 10⁻⁴ mol dm⁻³ level could be determined with coefficients of variations better than 0.2% (n = 5). The applicability of the developed cell to the flow injection analysis of anions was also discussed.     

Relation of ankle-brachial index to the rate of decline of residual renal function in peritoneal dialysis patients

Aim: The aim of this study was to determine whether ankle‐brachial index (ABI) predicts the rate of decline of residual renal function (RRF) in peritoneal dialysis (PD) patients. Previous studies demonstrated the importance of loss of RRF in predicting all‐cause risk and cardiovascular mortality in PD patients. It is also known that patients with a low ABI value have a greater risk for deteriorating renal function in the general population. The relationship between ABI and the declining rate of RRF in PD patients with an additional dialysis‐specific risk factor is uncertain. Methods: Seventy‐four PD patients with RRF of more than 1 mL/min per 1.73 m² were analyzed. ABI was used as the surrogate measure of pre‐existing cardiovascular disease and atherosclerosis burden to further determine the outcome of RRF in this study. The slope of decline of RRF was used to determine the outcome. Results: Based on the multivariate analysis, only ABI (P < 0.001), diabetes (P = 0.02) and baseline RRF (P = 0.009) independently predicted a faster decline in RRF. A stepwise multiple linear regression analysis demonstrated that ABI was an independent predictor for the slope of decline of RRF (P < 0.001). Conclusion: A low ABI is an independent predictor of not only the known atherosclerotic events, but also of the rate of decline of RRF over time in PD patients.     

Multinational study in children and adolescents with newly diagnosed type 1 diabetes: association of age,ketoacidosis, HLA status,and autoantibodies on residual beta‐cell function and glycemic control 12 months after diagnosis

HB Mortensen, PGF Swift, RW Holl, P Hougaard, L Hansen, H Bjoerndalen, CE de Beaufort, M Knip. Multinational study in children and adolescents with newly diagnosed type 1 diabetes: association of age, ketoacidosis, HLA status, and autoantibodies on residual beta‐cell function and glycemic control 12 months after diagnosis. Objective: To identify predictors of residual beta‐cell function and glycemic control during the first 12 months after the diagnosis of type 1 diabetes (T1D). Subjects and Methods: Clinical information and blood samples were collected from 275 children. HbA1c, antibodies, HLA typing and mixed meal‐stimulated C‐peptide levels 1, 6, and 12 months after diagnosis were analyzed centrally. Results: Mean age at diagnosis was 9.1 yr. DKA with standard bicarbonate <15 mmol/L was associated with significantly poorer residual beta‐cell function 1 (p = 0.004) and 12 months (p = 0.0003) after diagnosis. At 12 months, the decline in stimulated C‐peptide levels compared with the levels at 1 month was 69% in the youngest age group and 50% in patients 10 yr and above (p < 0.001). Stimulated C‐peptide at 12 months was predicted by younger age (p < 0.02) and bicarbonate levels at diagnosis (p = 0.005), and by stimulated C‐peptide (p < 0.0001), postmeal blood glucose (p = 0.0004), insulin antibodies (IA; p = 0.02) and glutamic acid decarboxylase antibodies (GADA; p = 0.0004) at 1 month. HbA1c at 12 months was predicted by HbA1c at diagnosis (p < 0.0001), GADA at 1 month (p = 0.01), and non‐white Caucasian ethnicity (p = 0.002). Conclusions: Younger age, ketoacidosis at diagnosis, and IA and GADA 1 month after diagnosis were the strongest explanatory factors for residual beta‐cell function at 12 months. Glycemic control at 12 months was influenced predominantly by ethnicity, HbA1c at diagnosis, and GADA at 1 month.     

Polythiophenes with Carbazole Side Chains: Design,Synthesis and Their Application in Organic Solar Cells

A series of polythiophene derivatives P1‐P5 containing carbazole side chains were designed and synthesized via the Stille polymerization. All carbazole containing polymers showed broad absorption in the visible region. The power conversion efficiencies of solar cells based on blends of two component copolymers and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PC₆₁BM) were determined to be 0.29 and 0.56% for P1 and P5 , respectively. For solar cells fabricated with the three component copolymers and PC₆₁BM, the efficiencies were 0.56% for P2 , 0.86% for P3 , and 0.70% for P4 . The introduction of electron‐donating carbazole side chains can broaden the absorption in the visible region and meanwhile reduce phase separation due to the steric hinderance of the carbazole moiety to the conjugated main chain. Improving efficiency needs a balance of broad absorption and ordered packing of polymer chains in the solid state.

     

Spectroelectrochemical and Photovoltaic Characterization of a Solution‐Processable n‐and‐p Type Dopable Pyrrole‐Bearing Conjugated Polymer

D‐A‐D‐type polymers are of high interest in the field of photovoltaics and electrochromism. In this study we report the synthesis and electrochemical properties of PPyBT along with its photophysical properties and photovoltaic performance. PPyBT is soluble in common organic solvents and both n‐ and p‐type dopable, which is a desired property for conjugated polymers. During electrochemistry studies, the onset potentials of the polymer were determined as +0.2 V for oxidation and ?1.4 V for reduction. Using these values, HOMO and LUMO energy levels were calculated. The photovoltaic properties of PPyBT were also studied. PL studies showed that there is a charge transfer between PPyBT (donor) and PCBM (acceptor).

     

Photoinduced Controlled Radical Polymerization in Methanol

Photoinduced CRP of methyl methacrylate initiated by in situ generation of copper (I) complex from higher oxidation state species in methanol was investigated. The polymerizations proceeded in a well‐controlled manner under UV light at room temperature as evidenced by kinetic and chain extension studies. The evolution of molecular weight with conversion showed good correlation between experimental and theoretical molecular weights, which confirmed good control over polymerization and ensured a narrow MWD. The effect of the methanol on the polymerization was also investigated, and a better agreement between experimental and theoretical molecular weights with a quite narrow MWD was obtained by using methanol as solvent.

     

Renal Transport of Adefovir,Cidofovir, and Tenofovir by SLC22A Family Members (hOAT1, hOAT3, and hOCT2)

Purpose The nephrotoxicity of the nucleotide antivirals adefovir, cidofovir and tenofovir is considered to depend on the renal tubular transport of them. Although it is known that the antivirals are substrates of the human renal organic anion transporter hOAT1 (SLC22A6), there is no information available on other organic ion transporters. The aim of the present study was to investigate whether the other renal organic anion transporter hOAT3 (SLC22A8) and organic cation transporter hOCT2 (SLC22A2) transport the antivirals. Materials and Methods Uptake experiments were performed using HEK293 cells transfected with cDNA of the organic ion transporters. Results The uptake of adefovir, cidofovir and tenofovir in monolayers stably expressing hOAT3 increased time-dependently, compared with control. Probenecid, a typical inhibitor of organic anion transporters, completely inhibited their transport. The amounts of the antivirals taken up by hOAT3 were much lower than those by hOAT1. The transient expression of hOCT2 did not increase uptake of the antivirals. Conclusion These results indicate that adefovir, cidofovir and tenofovir are substrates of hOAT3 as well as hOAT1, but that quantitatively hOAT1 is the major renal transporter for these drugs.     

残余肾功能对腹膜透析患者心血管系统的影响

目的:观察不同残余肾功能(RRF)对腹膜透析(PD)患者心血管系统的影响. 方法:根据PD患者随访过程中残余肾小球滤过率(rGFR)水平将其分为A组(GFR 0～2 ml/min)、B组GFR(2.1～4 ml/min)、C组GFR(4.1～6.0 ml/min)和D组(>6.0 ml/min).每3个月对患者进行一次临床随访,全面评估患者的伞身情况及透析状态,包括血浆白蛋白(AIb)、收缩压(SBP)、舒张压(DBP)、体重指数(BMI)、尿量(UV)、残余肾肌酐清除率(Ccr)、每周总尿素氮清除率(Kt/V total)、每周肌酐总清除率(WCcr total)、蛋白氮呈现率(nPNA)、心脏超声和胸部平片. 结果:四组不同RRF患者Kt/v total分别为1.66±0.42、1.85±0.40、2.11±0.45、2.60±0.69(P<0.01);四组间心胸比分别为0.54±0.08、0.51±0.07、0.51±0.06、0.50±0.06(P<0.05);左室后壁厚度分别为(10.4±1.79)、(9.96±1.35)、(9.51±1.33)、(9.65±1.40)mm(P<0.05);室间隔厚度分别为(10.9±1.88)、(10.4±1.59)、(10.2±1.59)、(10.1±1.47)mm(P<0.05);此外四组间AIb、SBP、DBP均存在统计学差异(P<0.05). 结论:RRF每下降2 ml/min患者室间隔厚度、左室后壁厚度均增加,且室间隔厚度与RRF呈负相关.RRF对腹膜透析患者心血管并发症有重要影响.