Insights into the Nature of Synergistic Effects in Proton-Conducting 4,4−1H,1H-Bitriazole-Poly(ethylene oxide) Composites

A nitrogen-containing heterocycle (NCH), 4,4-1H-1H-bi-1,2,3-triazole (bitriazole), capable of mimicking the hydrogen bonding of water in the solid state is synthesized and its ability to conduct protons in the presence of poly(ethylene oxides) under anhydrous conditions is investigated. Bitriazole is shown to have sufficient thermal and electrochemical stability for fuel cell applications. The composites formed between bitriazole and poly(ethylene oxides) give proton conductivities that can be described by the Vogel−Tamman−Fulcher (VTF) equation. These characteristics suggest coupling between polymer segmental motion and ion transport. The bitriazole N-H proton is shown to be the source of conductivity, and bitriazole and poly(ethylene oxides) function synergistically through specific intermolecular interactions and polymer-induced segmental motion to create a pathway for proton transport via structural diffusion

Proton-Conducting Solid Electrolyte via Ozonolysis of Cationic Ammonium Organoalkoxysilane Surfactant-Templated MCM-41

A functional polymerizable surfactant has been synthesized and used as a template to prepare MCM-41. Ozonolysis of the olefin functional group in the composite material generates a nonporous proton-conducting solid acid that has a conductivity of ca. 6 mS cm^(-1) at 95 °C and an activation energy of 14.2 kJ/mol

Proton-Conducting Solid Electrolyte via Ozonolysis of Cationic Ammonium Organoalkoxysilane Surfactant-Templated MCM-41

A functional polymerizable surfactant has been synthesized and used as a template to prepare MCM-41. Ozonolysis of the olefin functional group in the composite material generates a nonporous proton-conducting solid acid that has a conductivity of ca. 6 mS cm^(-1) at 95 °C and an activation energy of 14.2 kJ/mol

High-Resolution Monitoring for Thermal Remediation Optimization

Abstract is in response to call for abstracts for Battelle Chlorinated Solvent Conference. The abstract discusses how we conducted high-resolution monitoring for thermal remediation optimization

Thermo-Mechanical Fatigue Crack Growth of RR1000

Non-isothermal conditions during flight cycles have long led to the requirement for thermo-mechanical fatigue (TMF) evaluation of aerospace materials. However, the increased temperatures within the gas turbine engine have meant that the requirements for TMF testing now extend to disc alloys along with blade materials. As such, fatigue crack growth rates are required to be evaluated under non-isothermal conditions along with the development of a detailed understanding of related failure mechanisms. In the current work, a TMF crack growth testing method has been developed utilising induction heating and direct current potential drop techniques for polycrystalline nickel-based superalloys, such as RR1000. Results have shown that in-phase (IP) testing produces accelerated crack growth rates compared with out-of-phase (OOP) due to increased temperature at peak stress and therefore increased time dependent crack growth. The ordering of the crack growth rates is supported by detailed fractographic analysis which shows intergranular crack growth in IP test specimens, and transgranular crack growth in 90° OOP and 180° OOP tests. Isothermal tests have also been carried out for comparison of crack growth rates at the point of peak stress in the TMF cycles

Urocortin 2 Infusion in Healthy Humans Hemodynamic, Neurohormonal, and Renal Responses

ObjectivesWe sought to examine the effects of urocortin (UCN) 2 infusion on hemodynamic status, cardiovascular hormones, and renal function in healthy humans.BackgroundUrocortin 2 is a vasoactive and cardioprotective peptide belonging to the corticotrophin-releasing factor peptide family. Recent reports indicate the urocortins exert important effects beyond the hypothalamo-pituitary-adrenal axis upon cardiovascular and vasohumoral function in health and cardiac disease.MethodsWe studied 8 healthy unmedicated men on 3 separate occasions 2 to 5 weeks apart. Subjects received placebo, 25-μg low-dose (LD), and 100-μg high-dose (HD) of UCN 2 intravenously over the course of 1 h in a single-blind, placebo-controlled, dose-escalation design. Noninvasive hemodynamic indexes, neurohormones, and renal function were measured.ResultsThe administration of UCN 2 dose-dependently increased cardiac output (mean peak increments ± SEM) (placebo 0.5 ± 0.2 l/min; LD 2.1 ± 0.6 l/min; HD 5.0 ± 0.8 l/min; p < 0.001), heart rate (placebo 3.3 ± 1.0 beats/min; LD 8.8 ± 1.8 beats/min; HD 17.8 ± 2.1 beats/min; p < 0.001), and left ventricular ejection fraction (placebo 0.6 ± 1.4%; LD 6.6 ± 1.5%; HD 14.1 ± 0.8%; p < 0.001) while decreasing systemic vascular resistance (placebo −128 ± 50 dynes·s/cm5; LD −407 ± 49 dynes·s/cm5; HD −774 ± 133 dynes·s/cm5; p < 0.001). Activation of plasma renin activity (p = 0.002), angiotensin II (p = 0.001), and norepinephrine (p < 0.001) occurred only with the higher 100-μg dose. Subtle decreases in urine volume (p = 0.012) and natriuresis (p = 0.001) were observed.ConclusionsBrief intravenous infusions of UCN 2 in healthy humans induced pronounced dose-related increases in cardiac output, heart rate, and left ventricular ejection fraction while decreasing systemic vascular resistance. Subtle renal effects and activation of plasma renin, angiotensin II, and norepinephrine (at high-dose only) were observed. These findings warrant further investigation of the role of UCN 2 in circulatory regulation and its potential therapeutic application in heart disease

Vitamin B12 deficiency among adult diabetic patients in Uganda: relation to glycaemic control and haemoglobin concentration

BACKGROUND: Vitamin B12 deficiency is highly prevalent among adult individuals with diabetes yet screening is infrequent in Uganda. There are currently no published data regarding the prevalence of vitamin B12 deficiency and its associated factors among adult individuals with diabetes in sub-Saharan Africa. This study aimed at describing the prevalence and factors associated with vitamin B12 deficiency among this patient population in a resource constrained setting in sub-Saharan Africa. METHODS: In this cross-sectional study, 280 eligible study participants attending the outpatient diabetic clinic at Mulago national referral and teaching hospital in Kampala, Uganda were enrolled. Their socio-demographic, clinical and laboratory data was collected using a pre-tested questionnaire. RESULTS: The majority of the study participants were female (68.9 %), with a median age of 50 (IQR: 40-58) years. The mean (SD) serum vitamin B12 levels was 472.0 (16.4) pg/ml. The prevalence of vitamin B12 deficiency was 10.7 %. Hemoglobin level < 12 g/dl (AOR 3.38; 95 % CI 1.38-8.32, p value = 0.008) and glycated hemoglobin ≥ 7 % (AOR 3.29; 1.44-7.51, p value = 0.005) were associated with vitamin B12 deficiency. CONCLUSIONS: Vitamin B12 deficiency is prevalent in approximately 1 in 10 of adult individuals with diabetes in Uganda. We recommend screening for vitamin B12 deficiency among diabetic patients in Uganda especially those with low hemoglobin concentrations and glycated hemoglobin levels ≥ 7 %