Voltammetric determination of vildagliptin in a pharmaceutical formulation

Purpose: To determine vildagliptin concentration in a pharmaceutical formulation using voltammetric analysis techniques, and optimize the parameters affecting the techniques.Method: Four types of voltammetry techniques, including cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and linear sweep voltammetry (LSV), were employed to measure vildagliptin. Platinum (Pt) and glassy carbon (GC) were used as working electrodes, while KNO3 (1 M) and phosphate buffer (NaH2PO4/H3PO4) pH 6.8 were used to study optimal voltammetric analysis conditions.Results: CV results indicate that vildagliptin is electroactive and exhibits irreversible redox cycles while LSV results showed an oxidation peak current around 1.35 V that has high sensitivity and a linear standard regression line correlation coefficient of 0.9995. In addition, LSV results showed that vildagliptin has a lower limit of detection of ~ 0.241 mM and a limit of quantification of ~ 0.802 mM. Finally, the results show that vildagliptin has an acceptable level of recovery of 104.1 % and a relative standard deviation of 0.52 % for the commercially available vildagliptin tablets used in this study.Conclusion: The accuracy and precision of all applied voltammetric techniques for vildagliptin analysis are within accepted limits stipulated in pharmaceutical analysis quality control guidelines. The recommended method for vildagliptin analysis is LSV with Pt as the working electrode and KNO3 (1 M) as the supporting electrolyte.Keywords: Vildagliptin, Cyclic voltammetry, Square wave voltammetry, Differential pulse voltammetry, Linear sweep voltammetr

Influence of non-magnetic and magnetic ions on the MagnetoCaloric properties of La0.7Sr0.3Mn0.9M0.1O3 doped in the Mn sites by M=Cr, Sn, Ti

International audienceWe have studied the MagnetoCaloric Effect (MCE) in La0.7Sr0.3Mn0.9M0.1O3, M=Cr, Sn and Ti, prepared by a conventional solid state reaction. The temperature dependence of magnetization reveals that all compositions exhibit a ferromagnetic (FM) to paramagnetic (PM) transition at TC temperatures of 369, 326, 228 and 210 K, respectively for La0.7Sr0.3MnO3 (LSMO), La0.7Sr0.3Mn0.9Cr0.1O3 (LSMO-Cr), La0.7Sr0.3Mn0.9Sn0.1O3 (LSMO-Sn), and La0.7Sr0.3Mn0.9Ti0.1O3 (LSMO-Ti). Using Arrott plots, the phase transition from FM to PM is found to be of second order. The maximum magnetic entropy change (−ΔSM), at the applied magnetic field of 2 T, is found to be 1.27, 1.76, 0.47 and 1.45 J kg−1 K−1, respectively for LSMO, LSMO-Cr, LSMO-Sn and LSMO-Ti. The relative cooling power (RCP) for LSMO-Cr, LSMO-Sn and LSMO-Ti is in the order of 50%, 26% and 71%, respectively, compared to gadolinium (Gd). As a result, the LSMO-Cr and LSMO-Ti compounds can be considered as promising materials in magnetic refrigeration technology

Clinical and biochemical characteristics of children with juvenile idiopathic arthritis

Objective: To determine the clinical and biochemical characteristics of children with Juvenile Idiopathic Arthritis (JIA) at a tertiary care centre in Karachi, Pakistan. Study Design: A descriptive study. Place and Duration of Study: Paediatric Rheumatology Clinic of The Aga Khan University Hospital (AKUH), Karachi, from January 2008 to December 2011. Methodology: Clinical and laboratory profile and outcome of children less than 15 years of age attending the Paediatric Rheumatology Clinic of the Aga Khan University, Karachi with the diagnosis of Juvenile Idiopathic Arthritis according to International League against Rheumatism were studied. These children were classified into different types of JIA; their clinical and laboratory characteristics, response to therapy and outcome was evaluated. Results: Sixty eight patients satisfying the criteria of International League against Rheumatism (ILAR) for Juvenile Idiopathic Arthritis were enrolled during the study period of four consecutive years, their age ranged from 9 months to 15 years. Mean age at onset was 6.45 ± 4.03 years while mean age at diagnosis was 7.60 ± 3.93 years. Polyarticular was the most predominant subtype with 37 (54%) patients, out of these, 9 (24%) were rheumatoid factor positive. An almost equal gender predisposition was observed. Fever and arthritis were the most common presenting symptoms, with only 2 patients presenting with uveitis. Conclusion: The clinico-biochemical characteristics of JIA at the study centre showed a pattern distinct with early onset of disease, high frequency of polyarticular type and a higher rheumatoid factor (QRA) and ANA positivity in girls

Electrical conductivity and complex impedance analysis of La0.7-xNdxSr0.3Mn0.7Ti0.3O3 (x≤0.30) perovskite

International audiencePolycrystalline samples La0.7-xNdxSr0.3Mn0.7Ti0.3O3 (x= 0.10; 0.20 and 0.30) were prepared by a high-temperature solide-state reaction technique. The X-ray diffraction shows that all the samples crystallize in the orthorhombic structure, Pbnm space group, with presence of a minor unreacted Nd2O3. The electrical response was studied by impedance complex spectroscopy over a broad frequency range (40-100 MHz) at room temperature. The values of ac conductivity for all samples were fitted by the Jonscher law σ ( ω ) = σ dc + A ω s . For x= 0.10 and 0.20, hopping occurs between neighboring sites, whereas for x=0.30 the hopping process occurs through longer distance. Complex impedance plots exhibit semicircular arcs described by an electrical equivalent circuit, which indicates that the Nd-doped compounds obey a non-Debye relaxation proces

Religion and ethnicity at work:a study of British Muslim women's labour market performance

The literature on British Muslim women’s labour market experience suffers from four lacunae: the inadequate analysis of the multi-layered facets of their identities and the disadvantages they face; the narrow range of labour market outcomes studied (primarily labour market participation and unemployment); a lack of recent studies on the integration of Muslim women, educated in the UK and with English as their first language, into the labour market; and the absence of material on several sub-groups due to the lack of data, notably Arab, Christian Indian and White-British Muslim women. Using a large sample of data from the 2011 British census, the analyses presented here suggest that most non-White women face significant labour market penalties, with religion having a greater impact on labour market outcomes than race/ethnicity; Muslim women were the most disadvantaged, compared to other religious minorities, more so in relation to unemployment levels, part-time jobs and out of employment history, than in relation to occupational class and over-qualification. The results also suggest that the penalties facing Muslim women shaped by their ethnicity; not all Muslim women were similarly disadvantaged

Electrical Resistivity Behavior and VRH Transport Mechanism in Semiconducting La0.6Sr0.4Mn1−2x Fe x Cr x O3 (0.10≤x≤0.25) Manganites

International audienceThe transport properties and conduction mechanism in La0.6Sr0.4Mn1−2x Fe x Cr x O3 (0≤x≤0.3) have been investigated. The undoped samples show metal-semiconductor transition with a peak of resistivity at a temperature T P , whereas for all doped compounds the semiconducting behavior persists in the whole temperature range. The insertion of Cr3+ and Fe3+ ions leads to the increase of resistivity because the simultaneous substitution of Fe3+ and Cr3+ for Mn3+ reduces the number of available hopping sites for the Mn e g↑ electron and suppresses the double-exchange mechanism. It was found that the transport mechanism for substituted samples is dominated by the variable range hopping of small polarons between localized states in a model where the various parameters estimated from Mott's relation obey the variable range hopping (VRH) mechanism

Electrical and magnetic properties of La0.67Ba0.33Mn1−x (Me) x O3 perovskite manganites: case of manganese substituted by trivalent (Me = Cr) and tetravalent (Me = Ti) elements

International audienceThe effects of non-magnetic Ti4+ substitution on the structural, electrical and magnetic properties of La0.67Ba0.33Mn1−x Ti x O3 (0≤x≤0.1) are investigated and compared to those existing in La0.67Ba0.33Mn1−x Cr x O3 (magnetic Cr3+). The structural refinement by the Rietveld method revealed that Ti-doped samples crystallize in the cubic lattice with space group Pm3¯m , while samples with Cr crystallize in the hexagonal setting of the rhombohedral R3¯C space group for identical contents of dopant. The most relevant structural features are an increase of the lattice parameters, of the cell volume and of the inter-ionic distances with increasing Ti doping level. Both series of samples show a decrease of the paramagnetic-ferromagnetic transition temperature when the amount of chromium or titanium increases. Transport measurements show that when increasing the metal doping, the resistivity increases whereas the metallic behavior of the parent compound La0.67Ba0.33MnO3 is destroyed. For a substitution higher than 5 at.% of Ti and 10 at.% of Cr, the samples exhibit a semiconducting behavior in the whole range of temperature, for which the electronic transport can be explained by variable range hopping and/or small polaron hopping models

Leiomyosarcome de la langue: à propos d’un cas

Le léiomyosarcome primitif de la langue est une tumeur rare qui se développe aux dépens des fibres  musculaires lisses. Le diagnostic est souvent difficile, fondé sur des caractéristiques immuno- histologiques particulières. L'objectif de ce travail est de décrire le profil épidémiologique, clinique, thérapeutique et évolutif du léiomyosarcome à travers un cas et une revue de la littérature. Nous  rapportons le cas d'un homme âgé de 26 ans, sans antécédents pathologique particuliers, consultant pour une tuméfaction de la langue mobile évoluant depuis 2 ans. Une biopsie de la masse a été réalisée. L'étude anatomopathologique et  immunohistochimique a confirmé le diagnostic d'un léiomyosarcome de la langue. L'IRM de la langue a objectivé un processus lesionnel intéressant la portion mobile et antérieur de la langue. Une exérèse de la masse a été réalisée. L'examen histologique a montré la présence d'un large néoplasme de 6 cm compatible à un léiomyosarcome peu différencié de la langue , de garde II selon la Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC). Une radiothérapie externe sur la cavité buccale avec une dose de 65 Gy a été réalisée. Le patient a présenté 2 mois après la fin du  traitement une adénopathie latéro-cervicale haute  gauche (territoire II), il a bénéficié d'un curage  ganglionnaire fonctionnel intéressant les territoires I, II et III puis réadressé en radiothérapie. Le  léiomyosarcome de la langue est très rare surtout chez le sujet jeune. La chirurgie et la radiothérapie sont les armes thérapeutiques majeures. Le pronostic est très mauvais, Les facteurs les plus importants sont les marges d'exérèse et le grade.Key words: Léiomyosarcome, langue, muscle liss

The relationship between serum osteopontin level and parameters of Chronic Kidney Disease – mineral bone disease in patients on regular hemodialysis

Background: Chronic Kidney Disease (CKD) is becoming a major health concern worldwide. For many patients, CKD is associated with substantial morbidity and mortality. Osteopontin (OPN) is an extracellular matrix protein first identified in bone tissue and has pleiotropic functions due to its common expression in the main organs and apparatuses. It is a phosphorylated glycophosphoprotein composed of 314 amino acids, involved in biomineralization and remodeling.Objective: This research aimed to assess the serum level of osteopontin in patients with end-stage renal disease (ESRD) on regular haemodialysis and to correlate osteopontin level in patients with ESRD on hemodialysis with other biomarkers CKD-MBD.Patients & Methods: This Study was conducted on 160 participants that were divided into two groups. Control group included 80 healthy subjects of both sexes, and patients group that included 80 ESRD patients on regular hemodialysis of both sexes. All studied groups were subjected to osteopontin level by enzyme-linked immunosorbent assay (ELISA).Results: Serum osteopontin levels were higher in ESRD patients on regular dialysis than in healthy individuals, where it might have a higher predictive value for CKD development. Also, they were positively correlated with serum phosphorus, serum alkaline phosphatase and serum parathyroid hormone, which are parameters of chronic kidney disease-mineral and bone disorder.Conclusion: Osteopontin may be considered an early marker of chronic kidney disease