Development of a Hopkinson Bar Apparatus for Testing Soft Materials: Application to a Closed-Cell Aluminum Foam.

An increasing interest in lightweight metallic foams for automotive, aerospace, and other applications has been observed in recent years. This is mainly due to the weight reduction that can be achieved using foams and for their mechanical energy absorption and acoustic damping capabilities. An accurate knowledge of the mechanical behavior of these materials, especially under dynamic loadings, is thus necessary. Unfortunately, metal foams and in general "soft" materials exhibit a series of peculiarities that make difficult the adoption of standard testing techniques for their high strain-rate characterization. This paper presents an innovative apparatus, where high strain-rate tests of metal foams or other soft materials can be performed by exploiting the operating principle of the Hopkinson bar methods. Using the pre-stress method to generate directly a long compression pulse (compared with traditional SHPB), a displacement of about 20 mm can be applied to the specimen with a single propagating wave, suitable for evaluating the whole stress-strain curve of medium-sized cell foams (pores of about 1-2 mm). The potential of this testing rig is shown in the characterization of a closed-cell aluminum foam, where all the above features are amply demonstrated.

Elimination of Mother-To-Child Transmission of HIV Infection: The Drug Resource Enhancement against AIDS and Malnutrition Model.

The Drug Resource Enhancement against AIDS and Malnutrition Program (DREAM) gathered professionals in the field of Elimination of HIV-Mother-To-Child Transmission (EMTCT) in Maputo in 2013 to discuss obstacles and solutions for the elimination of HIV vertical transmission in sub-Saharan Africa. During this workshop, the benefits of administrating combined antiretroviral therapy (cART) to HIV positive women from pregnancy throughout breastfeeding were reviewed. cART is capable of reducing vertical transmission to less than 5% at 24 months of age, as well as maternal mortality and infant mortality in both HIV infected and exposed populations to levels similar to those of uninfected individuals. The challenge for programs targeting eMTCT in developing countries is retention in care and treatment adherence. Both are intrinsically related to the model of care. The drop-out from eMTCT programs before cART initiation ranges from 33%-88% while retention rates at 18-24 months are less than 50%. Comprehensive strategies including peer-to-peer education, social support and laboratory monitoring can reduce refusals to less than 5% and attain retention rates approaching 90%. Several components of the model of care for reduction of HIV-1 MTCT are feasible and implementable in scale-up strategies. A review of this model of care for HIV eMTCT is provided.

A global approach to the management of EMR (electronic medical records) of patients with HIV/AIDS in sub-Saharan Africa: the experience of DREAM software.

BACKGROUND: The DREAM Project operates within the framework of the national health systems of several sub-Saharan African countries and aims to introduce the essential components of an integrated strategy for the prevention and treatment of HIV/AIDS. The project is intended to serve as a model for a wide-ranging scale-up in the response to the epidemic. This paper aims to show DREAM's challenges and the solutions adopted. One of the solutions is the efficient management of the clinical data regarding the treatment of the patients and epidemiological analyses. METHODS: Specific software for the management of the patients' EMR has been created within the DREAM programme in order to deal with the challenges deriving from the context in which DREAM operates. Setting up a computer infrastructure in health centres, providing a power supply, as well as managing the data and the project resources efficiently and reliably, are some of the questions that have been analysed in this study. RESULTS: Over the years this software has proved that it is able to respond to the need for efficient management of the clinical data and organization of the health centres. Today it is used in 10 countries in sub-Saharan Africa by thousands of professionals and by now it has reached its fourth version. The medical files of over 73,000 assisted patients are managed by this software and the data collected with it have become essential for the epidemiological research that is carried out to improve the effectiveness of the therapy. CONCLUSION: Sub-Saharan Africa is the region hardest hit by HIV and AIDS in the world. However, the resources and responses adopted so far, to confront the epidemic, have at times been rather minimalist. The DREAM project has faced the battle against the epidemic by equipping itself with qualitative standards comparable to Western ones. The experience of DREAM has revealed that it is indeed possible to guarantee levels of excellence in developing countries, also in the sphere of ICT (Information and Communication Technology), thus making the intervention even more effective and contributing to bridging the digital divide.