Rigorous pH measurement in non-aqueous solution: measurement method and reference values in ethanol.

The recently introduced unified pH ([Formula: see text]) concept enables rigorous pH measurements in non-aqueous and mixed media while at the same time maintaining comparability to the conventional aqueous pH scale. However, its practical application is hindered by a shortage of reference [Formula: see text] values. In order to improve this situation, the European Metrology Research Project (EMPIR) UnipHied ("Realisation of a UnipHied pH scale") launched an interlaboratory comparison among highly experienced electrochemistry expert laboratories to assign the first such reference [Formula: see text] values by adopting an extensive statistical treatment of the reported measurement data: to phosphate buffer in water-ethanol mixture (50 wt% of ethanol) and ammonium formate buffer in pure ethanol. Two different measurement setups - one capable of being easily adopted in industrial applications - have been used to demonstrate the robustness of [Formula: see text] measurement. This is an important step towards wider adoption of the [Formula: see text] concept in practice, like liquid chromatography, biofuels analysis and electrocatalysis.

Evaluation and validation of detailed and simplified models of the uncertainty of unified [Formula: see text] measurements in aqueous solutions.

The use of the unified pH concept, [Formula: see text] , applicable to aqueous and non-aqueous solutions, which allows interpreting and comparison of the acidity of different types of solutions, requires reliable and objective determination. The [Formula: see text] can be determined by a single differential potentiometry measurement referenced to an aqueous reference buffer or by a ladder of differential potentiometric measurements that allows minimisation of inconsistencies of various determinations. This work describes and assesses bottom-up evaluations of the uncertainty of these measurements, where uncertainty components are combined by the Monte Carlo Method (MCM) or Taylor Series Approximation (TSM). The MCM allows a detailed simulation of the measurements, including an iterative process involving in minimising ladder deviations. On the other hand, the TSM requires the approximate determination of minimisation uncertainty. The uncertainty evaluation was successfully applied to measuring aqueous buffers with pH of 2.00, 4.00, 7.00, and 10.00, with a standard uncertainty of 0.01. The reference and estimated values from both approaches are metrologically compatible for a 95% confidence level even when a negligible contribution of liquid junction potential uncertainty is assumed. The MCM estimated pH values with an expanded uncertainty, for the 95% confidence level, between 0.26 and 0.51, depending on the pH value and ladder inconsistencies. The minimisation uncertainty is negligible or responsible for up to 87% of the measurement uncertainty. The TSM quantified measurement uncertainties on average only 0.05 units larger than the MCM estimated ones. Additional experimental tests should be performed to test these uncertainty models for analysis performed in other laboratories and on non-aqueous solutions.

Unified pH Measurements of Ethanol, Methanol, and Acetonitrile, and Their Mixtures with Water.

Measurement of pH in aqueous-organic mixtures with different compositions is of high importance in science and technology, but it is, at the same time, challenging both from a conceptual and practical standpoint. A big part of the difficulty comes from the fundamental incomparability of conventional pH values between solvents (spH, solvent-specific scales). The recent introduction of the unified pH (pHabs) concept opens up the possibility of measuring pH, expressed as pHabsH2O, in a way that is comparable between solvent, and, thereby, removing the conceptual problem. However, practical issues remain. This work presents the experience of the authors with measuring pHabsH2O values in mixtures of methanol, ethanol, and acetonitrile, with water, but without the presence of buffers or other additives. The aim was to assigned pHabsH2O values to solvent-water mixtures using differential potentiometry and the 'pHabs-ladder' method. Measurements were made of the potential difference between glass electrodes immersed in different solutions, separated by an ionic liquid salt bridge. Data were acquired for a series of solutions of varying solvent content. This work includes experiences related to: a selection of commercial electrodes, purity of starting material, and comparability between laboratories. Ranges of pHabsH2O values for selected compositions of solvent-water mixtures are presented.

Scimitar syndrome associated with aberrant right subclavian artery, diaphragmatic hernia, and urinary anomalies - case report and review of the literature.

Scimitar syndrome is a form of a partially or totally right pulmonary venous return to the inferior vena cava, which may associate variably right lung hypoplasia, right pulmonary artery hypoplasia, pulmonary sequestration together with the presence of aortopulmonary collaterals from the descending aorta towards the right lung. In many cases, there are also other cardiac anomalies associated. We present a unique association of a partially anomalous pulmonary venous return to the inferior vena cava with other vascular and thoracic anomalies: inferior sinus venosus and secundum atrial septal defect, retroesophageal right subclavian artery, obstructed accessory right bronchus, diaphragmatic hernia with ectopic liver, "S"-type thoracic scoliosis and malformations of the urinary tract (duplication of the right ureter and of the left basinet). The patient had a reimplantation of the "scimitar" vein to the left atrium and closure of the inferior sinus venosus and secundum atrial septal defect.

Laparoscopic Repair of a Left Retrocaval Ureter in a 16-Year-Old Girl.

Left retrocaval ureter is an extremely rare congenital malformation which is associated with situs inversus, duplicated or translated inferior vena cava (IVC). We report a female adolescent who presented with a history of intermittent, colicky lumbar pain. Diagnostic workup revealed left retrocaval ureter and left ureterohydronephrosis. The girl underwent laparoscopy. The renal pelvis and ureter posterior to the vena cava were dissected, transected at the caudal point of the dilated ureteral segment, and uncrossed and repositioned lateral to the vena cava. Ureteroureterostomy was performed over a double-J ureteral stent after spatulation of the distal ureter. The postoperative course was uneventful and the ureteral stent removed after 5 weeks. During follow-up, the patient is symptom-free. Our case demonstrates that our laparoscopic approach is feasible in this rare anatomic anomaly.

Sensitivities of key parameters in the preparation of silver/silver chloride electrodes used in Harned cell measurements of pH.

A questionnaire was completed by fourteen world leading national metrology institutes to study the influence of several variables in the preparation of Ag/AgCl electrodes on the accuracy of Harned cell measurements of pH. The performance of each institute in the last decade has been assessed based on their results in eight key comparisons, organized by the Bureau International des Poids et Measures Consultative Committee for Amount of Substance, involving the measurement of pH of phosphate, phthalate, carbonate, borate and tetroxalate buffer solutions. The performance of each laboratory has been correlated to the results of the questionnaire to determine the critical parameters in the preparation of Ag/AgCl electrodes and their sensitivities with respect to the accuracy of pH measurement. This study reveals that the parameters most closely correlated to performance in comparisons are area of electrode wire exposed to the electrolyte, diameter and porosity of the Ag sphere prior to anodisation, amount of Ag converted to AgCl during anodisation, stability times employed for electrodes to reach equilibrium in solution prior to measurement, electrode rejection criteria employed and purity of reagents.

[The quality of life if HIV/AIDS patients in Iasi Romania]. / Calitatea vietii la pacientii Centrului Regional HIV/SIDA din Iasi.

UNLABELLED: Quality of life in relation to health is a consequence of disease and treatment on the patient's perception of his ability to have a full and useful life. Due to its nature, the quality of life is a multidimensional and subjective construct, based on the patient's experience. We operationalized the quality of life using the following parameters: CD4 count and HIV viral levels in the patient's blood, the number of days of hospitalization, number of antiretroviral plans, types of side effects and their frequency, psychological issues (anxiety, depression, and neurotic tendencies). METHODS: We centralized data from a total of 600 patients from the Regional Center in Iasi in 2010-2011. Side effects accused by the patients emerged from discussions with the infectious disease doctor and psychologist, and psychological aspects were measured by specific instruments (PA Inventory, Beck Depression Scale). RESULTS: Most patients enrolled in the study were male (59%) with mean age of 21.1 years. 34% of them came from rural areas. Average schooling level was 6 primary classes, with extremes between the two classes of primary and higher education. Only 14% of patients had a job, while the rest did not have a stable job or were not employed. 38% came from broken homes or foster care. 85% of patients were in therapy at the time of data centralization. 55% were in the second, third or fourth regimen. 25% were at their first scheme, while 10% in the seventh - eighth scheme. The mean CD4 count ranged between 13 and 269/mmc, while the average viral load varied between 1730 and 3.180.000/mmc. The average number of days of hospitalization was 4. Among the antiretroviral side effects patients complained nausea and vomiting in 85% of cases, lipodystrophy symptoms in 25% of cases, diarrhea 15%. With regard to psychological aspects, 65% of patients showed an above average level of anxiety, 40% showed depressive symptoms, while 10% had specific obsessions-compulsions, and 10% neurotic and hysterical tendencies. CONCLUSIONS: By measuring the quality of life through the above parameters, we obtained a clear and comprehensive picture of the situation facing the HIV patient. We believe that close cooperation between the team of doctors and psychologists assisting the infectious patient, on the one hand, and specialists in other medical fields that interact with the patient, on the other hand, can enhance the quality of life of the HIV patient and maintain it at a comfortable level.

Polyepichlorhydrin membranes for alkaline fuel cells: sorption and conduction properties.

Polymer electrolytes, using a poly(epichlorhydrin-allyl glycidyl ether) copolymer as matrix, are shown to perform well in alkaline fuel cell electrolyte. An anion-conducting network is obtained by the incorporation of cyclic diamines, 1,4-diazabicyclo[2.2.2]octane (DABCO) and 1-azabicyclo[2.2.2]octane (quinuclidine). The physicochemical and electrochemical characteristics are evaluated. The best conductivity of 1.3.10 (-2) S/cm is obtained at 60 degrees C and a relative humidity of RH = 98%. Ionic conductivity is particularly sensitive to relative humidity. To gain insight into the OH (-) conduction mechanism and the role of water, sorption measurements versus water activity, differential scanning calorimetry, and NMR measurements are carried out.