Neutron diffraction of calcium aluminosilicate glasses and melts

International audienceThe combination of neutron diffraction with aerodynamic levitation and laser heating, pioneered by Neville Greaves and co-workers about 15 years ago, is an important tool for studying the structure of liquid melts. Since the first work on liquid Al2O3 published in 2001, the technique has been largely improved and experiments are now routinely performed at neutron sources, providing interesting structural information on various materials.In this paper, the structure of glass-forming compounds in the system CaO-Al2O3-SiO2 was measured by applying neutron diffraction with aerodynamic levitation. Results obtained in the liquid state above the melting point and from the glass at room temperatures are presented. Various compositions were studied by increasing the silica content and by changing the ratio CaO/Al2O3. As observed using other methods, the main structural changes relate to modification of the Al-O short range order

Internet of Things for Sustainability: Perspectives in Privacy, Cybersecurity, and Future Trends

In the sustainability IoT, the cybersecurity risks to things, sensors, and monitoring systems are distinct from the conventional networking systems in many aspects. The interaction of sustainability IoT with the physical world phenomena (e.g., weather, climate, water, and oceans) is mostly not found in the modern information technology systems. Accordingly, actuation, the ability of these devices to make changes in real world based on sensing and monitoring, requires special consideration in terms of privacy and security. Moreover, the energy efficiency, safety, power, performance requirements of these device distinguish them from conventional computers systems. In this chapter, the cybersecurity approaches towards sustainability IoT are discussed in detail. The sustainability IoT risk categorization, risk mitigation goals, and implementation aspects are analyzed. The openness paradox and data dichotomy between privacy and sharing is analyzed. Accordingly, the IoT technology and security standard developments activities are highlighted. The perspectives on opportunities and challenges in IoT for sustainability are given. Finally, the chapter concludes with a discussion of sustainability IoT cybersecurity case studies

Growth of nanostructures by cluster deposition : a review

This paper presents a comprehensive analysis of simple models useful to analyze the growth of nanostructures obtained by cluster deposition. After detailing the potential interest of nanostructures, I extensively study the first stages of growth (the submonolayer regime) by kinetic Monte-Carlo simulations. These simulations are performed in a wide variety of experimental situations : complete condensation, growth with reevaporation, nucleation on defects, total or null cluster-cluster coalescence... The main scope of the paper is to help experimentalists analyzing their data to deduce which of those processes are important and to quantify them. A software including all these simulation programs is available at no cost on request to the author. I carefully discuss experiments of growth from cluster beams and show how the mobility of the clusters on the surface can be measured : surprisingly high values are found. An important issue for future technological applications of cluster deposition is the relation between the size of the incident clusters and the size of the islands obtained on the substrate. An approximate formula which gives the ratio of the two sizes as a function of the melting temperature of the material deposited is given. Finally, I study the atomic mechanisms which can explain the diffusion of the clusters on a substrate and the result of their mutual interaction (simple juxtaposition, partial or total coalescence...)Comment: To be published Rev Mod Phys, Oct 99, RevTeX, 37 figure

Immunosuppression in relapsing remitting multiple sclerosis: moving towards personalized treatment

Introduction: Therapeutic armamentarium in Multiple Sclerosis (MS) has radically changed in the last few decades due to the development of disease modifying treatments (DMTs) with highly selective mechanisms of action. Areas covered: In this review, the authors will focus on the current role of immunosuppressive DMTs in the management of the relapsing-remitting form of MS (RRMS), moving from the rationale of its use and looking at the possibility to design an idealistic scenario of a personalized approach for each single patient. Expert opinion: Questions remain open about whether initial high-efficacy immunosuppressive DMTs improve long-term outcomes, whether prolonged exposure to these agents increases adverse events and what the strongest early surrogate markers are for predicting long-term treatment responses to high-efficacy drugs. In this way, the immunosuppressive DMTs, are used to hit the immune system early and hard with the idealistic goal of striking the autoimmune activities before the neurological damage becomes irreversible

Grynfeltt-Lesshaft hernia Personal experience of nine cases and a review of the literature

L’ernia lombare di Grynfeltt, dall’ autore che per primo l’ha descritta nel 1866, fra tutte le ernie della parete addominale è la più rara, rappresenta infatti secondo i dati della letteratura più recente solo il 2% di tutte le ernie. Di queste circa il 20% è congenita, secondaria principalmente a difetti di sviluppo embrionale mentre l’80% sono difetti acquisiti. Gli interventi chirurgici, le ferite penetranti e le infezioni rappresentano fattori di rischio per lo sviluppo di ernie lombari secondarie e pertanto iatrogene. In letteratura è riportata una prevalenza dell’ernia a sinistra mentre eccezionale è l’osservazione di una ernia di Grynfeltt bilaterale. La recente osservazione di una voluminosa ernia di Grynfeltt ci ha indotti a rivedere l’argomento e ad eseguire una revisione della letteratura e della nostra casistica. Sulla base della nostra esperienza personale, in accordo con la letteratura più recente, riteniamo che nel caso di ernie lombari di Grynfeltt, l’approccio laparotomico con utilizzo di materiali protesici sia il più appropriato, rendendo così la procedura rapida, facile e sicura, in controtendenza al trattamento di tutti gli altri difetti della parete per i quali preferiamo sempre un approccio laparoscopico. A conferma di ciò si percepisce che la tecnica open attualmente sia più diffusa, infatti una piccola lombotomia risulta di facile esecuzione, rapida e può essere eseguita anche in anestesia loco-regionale o epidurale.Grynfeltt's lumbar hernia, from the author who first described it in 1866, is the rarest among all hernias of the abdominal wall and it represents, according to the most recent literature, only 2% of all hernias. Of these, about 20% are congenital, secondary mainly to defects of embryonic development, while 80% are acquired defects. Surgeries, penetrating wounds, and infections are risk factors for the development of secondary and therefore iatrogenic lumbar hernias. In the literature, there is a predominance of the left Grynfeltt hernia while a bilateral presentation is exceptional. Our recent observation of a massive Grynfeltt hernia brought us to perform a revision of the literature and of our case studies. Based on our personal experience, with the most recent literature, we believe that in the case of Grynfeltt's lumbar hernias, the laparotomy approach with the use of prosthetic materials is the most appropriate, thus making the procedure fast, easy, and safe, compared to the treatment of all other wall defects that often require a laparoscopic approach. To confirm this, it is perceived that the open technique is currently more widespread; in fact, a small lumbotomy is easy to perform, fast, and can also be performed under loco-regional or epidural anaesthesia. KEY WORDS: Lumbar hernioplasty, Grynfeltt hernia, Hernia repair