Development and validation of a microbiological assay for determination of chlorhexidine digluconate in aqueous solution

Chlorhexidine (CHX) is a broad-spectrum antiseptic that is used in many topical pharmaceutical formulations. Because there is no official microbiological assay reported in the literature that is used to quantify CHX, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method for the dosage of chlorhexidine digluconate (CHX-D) in an aqueous solution. The assay is based on the inhibitory effect of CHX-D upon the strain of Staphylococcus aureus ATCC 25923, which is used as the test microorganism. The design 3x3 parallel-line model was used. The results were treated statistically by analysis of variance (ANOVA), and they were excellent in terms of linearity (r = 0.9999), presenting a significant regression between the zone diameter of growth inhibition and the logarithm of the concentration within the range of 0.5 to 4.5%. The results obtained were precise, having relative standard deviations (RSD) for intra-day and inter-day precision of 2.03% and 2.94%, respectively. The accuracy was 99.03%. The method proved to be very useful and appropriate for the microbiological dosage of CHX-D in pharmaceutical formulations; it might also be used for routine drug analysis during quality control in pharmaceutical industries

Amperometric and impedance monitoring systems for biomedical applications

The book presents the conception and realization of a pervasive electronic architecture for electrochemical applications, focusing on electronic instrumentation design and device development, particularly in electrochemical Point-of-Care and Lab-on-a-Chip devices, covering examples based on amperometric (DC) and impedance detection (AC) techniques. The presented electronics combine tailored front-end instrumentation and back-end data post-processing, enabling applications in different areas, and across a variety of techniques, analytes, transducers and environments. It addresses how the electronics are designed and implemented with special interest in the flow process: starting from electronic circuits and electrochemical biosensor design to a final validation and implementation for specific applications. Similarly, other important aspects are discussed throughout the book, such as electrochemical techniques, different analytes, targets, electronics reliability and robustness. The book also describes the use of the presented electronics in different electrochemical applications through some examples: instantaneous and non-destructive cellular monitoring and portable glucose monitoring device. Moreover, the book aims to introduce a comprehensive approach to electronic circuits, techniques and electrochemical sensors in POC devices to a general audience of students in biomedical and electronics engineering, scientists, and engineers

Access to microcredit for women living with, or vulnerable to, HIV in Haïti

Haïti is the poorest country on the American continent. It is also the Caribbean nation where HIV prevalence is the highest: 2.2% of the adults carry the virus.In 2005, GHESKIO, a centre for the care of people living with HIV/AIDS; ACME, Association for Cooperation with Micro Enterprise; and Fondation Mérieux launched a microcredit programme to help women living with HIV/AIDS. The programme was subsequently extended to vulnerable women who had consulted at GHESKIO.In 2006, an impact assessment of the programme among the first 66 women benefiting from a loan showed better living conditions compared to a control group of 30 women with similar initial medical and socioeconomic status but no loan. By mid-2008, 1061 women were the beneficiaries of 1538 loans totalling 11 373 000 gourdes, i.e. approximately 216 000€. Of these, 247 received several loans (up to seven loans to date).Although the women are very poorly educated and live in arduous economic circumstances, the loan repayment records are excellent – around 94% as of mid 2008. There is no difference between HIV-negative women and those living with HIV. Combined with antiretroviral treatment, micro-financing is certainly one of the major instruments for reducing the impact of HIV on the infected populations in countries with limited resources. This programme in Haiti is a demonstration of the feasibility of microcredit in a difficult environment. The great professionalism of the institutions implementing the programme is a key factor in its success.<br>Haïti est le pays le plus pauvre du continent américain. C’est également la région des Caraïbes qui affiche la plus forte prévalence de VIH : 2,2 % des adultes sont porteurs du virus.En 2005, GHESKIO, un centre de soins pour les personnes atteintes du VIH/SIDA, ACME (Association for Cooperation with Micro Enterprise) et la Fondation Mérieux ont lancé un programme de microcrédit pour aider les femmes atteintes du VIH/SIDA. Le programme a ensuite été étendu aux femmes vulnérables qui avaient consulté chez GHESKIO.En 2006, une évaluation de l’impact du programme réalisée auprès des 66 premières femmes à avoir bénéficié d’un prêt, a montré de meilleures conditions de vie comparé à un groupe témoin de 30 femmes au statut médical et socioéconomique initial similaire mais n’ayant pas bénéficié de prêt. Mi-2008, 1061 femmes bénéficiaient de 1538 prêts soit l’équivalent de 11 373 000 gourdes, environ 216 000 euros. Parmi elles, 247 recevaient plusieurs prêts (jusqu’à sept à ce jour).Bien que les femmes aient un niveau d’instruction médiocre et vivent dans des conditions économiques difficiles, les taux de remboursement des prêts sont excellents : environ 94 % mi-2008. Aucune différence n’a été constatée entre les femmes VIH-négatives et les femmes atteintes du VIH. Associé à un traitement antirétroviral, le micro-financement est certainement l’un des principaux moyens pour réduire l’impact du VIH sur les populations infectées dans les pays aux ressources limitées. Ce programme mis en œuvre en Haïti démontre la faisabilité du microcrédit dans un environnement difficile. L’extrême professionnalisme des institutions qui appliquent le programme est essentiel à la réussite de celui-ci.<br>Haití es el país más pobre del continente norteamericano. También es la nación del Caribe donde la prevalencia del VIH es más alta: el 2,2% de los adultos son portadores del virus.En 2005, GHESKIO, un centro para el cuidado de las personas que viven con el VIH/SIDA; ACME, la Asociación para la Cooperación con Microempresas; y la Fundación Mérieux lanzaron un programa de microcréditos para ayudar a mujeres que viven con el VIH/SIDA. El programa se amplió posteriormente a mujeres vulnerables que habían sido atendidas en GHESKIO.En 2006, una evaluación del impacto del programa entre las primeras 66 mujeres que se beneficiaron de un préstamo mostraron mejores condiciones de vida en comparación con un grupo de control de 30 mujeres con una situación socioeconómica y médica inicial semejante, pero que no habían recibido ningún préstamo. A mediados de 2008, 1.061 mujeres se habían beneficiado de los 1.538 préstamos que ascienden a un total 11.373.000 gourdes, es decir aproximadamente 216.000 €. De éstas, 247 recibieron varios préstamos (hasta siete préstamos hasta la fecha).Aunque las mujeres tienen una educación muy pobre y viven en circunstancias económicas duras, los registros de devolución de préstamo son excelentes, alrededor del 94% a mediados de 2008. No hay diferencia entre mujeres VIH negativas y las que viven con el VIH.En combinación con el tratamiento antirretroviral, la microfinanciación es ciertamente uno de los principales instrumentos para reducir el impacto del VIH en las poblaciones infectadas de países con recursos limitados. Este programa en Haití es una demostración de la viabilidad del microcrédito en un medio difícil. La gran profesionalidad de las instituciones que ponen en práctica el programa es un factor clave para su éxito

Self-Powered energy harvester strain sensing device for structural health monitoring

International audienceThis paper presents an envisaged autonomous strain sensor device, which is dedicated to structural health monitoring applications. The paper introduces the ASIC approach that replaces the discrete approach of some of the main modules

Self-Powered Adaptive Switched Architecture Storage

International audienceAmbient energy harvesting coupled to storage is a way to improve the autonomy of wireless sensors networks. Moreover, in some applications with harsh environment or when a long service lifetime is required, the use of batteries is prohibited. Ultra-capacitors provide in this case a good alternative for energy storage. Such storage must comply with the following requirements: a sufficient voltage during the initial charge must be rapidly reached, a significant amount of energy should be stored and the unemployed residual energy must be minimised at discharge. To answer these apparently contradictory criteria, we propose a self-adaptive switched architecture consisting of a matrix of switched ultra-capacitors. We present the results of a self-powered adaptive prototype that shows the improvement in terms of charge time constant, energy utilization rate and then energy autonomy