Lifetime and effectiveness evaluation of ceramic pot filters

Poor water quality is a major contributing factor to disease in developing countries. Ceramic pot filters (CPFs) represent an effective and sustainable technology for poor communities, but the characterization of CPF lifetimes is on-going, and the water production seems to be the limiting factor. This dissertation describes laboratory and field investigations conducted to characterize the parameters that impact CPF effectiveness and lifetime in terms of water production and treatment efficacy, both under controlled and real use conditions. CPF initial flow rate is the most common quality control parameter, but it may not be representative of the long-term effectiveness of the CPF since other factors, as water quality and use practices, can have a significant impact on CPF lifetime. The experimental work demonstrated that, amongst the analyzed water parameters, turbidity is the principal indicator in determining CPF lifetime in term of water production. The relationship between turbidity and average flow rate was defined and followed a negative trend with a decreasing rate of 50mLh-1/NTU. A method that permits prediction of the average flow rate given the initial flow rate and the turbidity of the influent water, and determines the turbidity limit for a target average flow rate was established. The field investigation showed that CPFs could maintain bacterial removal efficacies above standards during the first 14 months of use, and flow rates in the recommended range during the first 10 months; however, consumers were tolerant of the lower flow rates. In general, filters were well accepted by users who appreciated the aesthetic quality of the treated water, reported lower incidences of health problems, and expressed their preference of the CPFs over other household treatments --Abstract, page iv

A safe transoral surgical approach to parapharyngeal tumor arising from deep lobe of parotid gland

The management of parapharyngeal tumor is surgical, but the approach remains a challenge. Attention should be paid to avoidance intra-operative bleeding or cranial nerves damage. We report a case of a 67-year-old male complaining of left-ear fullness. A submucosal mass arising from the lateral wall of oropharynx on the left side was observed. Magnetic resonance imaging detected a mass arising from the parotid gland, in particular from the deep lobe, and a fine needle biopsy was compatible with "Warthin tumor." We performed a mini-invasive transoral approach under magnification, previous isolation of homolateral vessels. The decision on which surgical approach to be used is determined by site, size vascularity, and histology of the tumor. A literature review of the main surgical approaches was performed. We performed a combined transoral dissection under magnification with cervicotomic exposure of the neck vascular bundle allowing to dissect the tumor and manage any intra-operative complications

Hyaluronic acid: perspectives in upper aero-digestive tract. A systematic review

Background: To date, topical therapies guarantee a better delivery of high concentrations of pharmacologic agents to the mucosa of the upper aerodigestive tract (UADT). The use of topical drugs, which are able to reduce mucosal inflammation and to improve healing tissues, can represent a relevant therapeutic advance. Topical sodium hyaluronate (SH) has recently been recognized as adjuvant treatment in the chronic inflammatory disease of the UADT. Aims: The aim of our work was to review the published literature regarding all the potential therapeutic effects of SH in the chronic inflammatory disease of UADT. Methods: Relevant published studies were searched in Pubmed, Google Scholar, Ovid using ("sodium hyaluronate" and "upper airways") or Medical Subject Headings. Results: At the end of our selection process, sixteen publications have been included. Six of them in the post-operative period of nasal-sinus surgery, 2 of them in pediatric patients affected by recurrent upper respiratory tract infections, 4 of them in reducing symptoms and preventing exacerbations of chronic upper airways in adult population, 4 of them in patients with chronic inflammatory disease of UADT, including gastro-esophageal reflux disease (GERD). Conclusions: Topical administration of SH plays a pivotkey role in the postoperative phase of patients undergoing FESS and nasal surgery, and positive results are generally observed in all the patients suffering from UADT chronic inflammatory disease

PROBING OXIDE HETEROSTRUCTURE INTERFACES THROUGH ANGLE RESOLVED AND RESONANT ELECTRON SPECTROSCOPIES

In the recent years, electronic devices have become smaller and faster, as well as more powerful and efficient. However, the size of the building blocks of the current electronics - i.e. the transistors - is quickly approaching the limits of manufacture. The need of a new generation of devices based on novel mechanisms is today essential. In this scenario, well-defined interfaces between oxide materials have produced novel electronic systems displaying a spectacular variety of properties with promising potentialities for future devices, such as colossal magnetoresistance, high-temperature superconductivity, magnetism at the interface between non magnetic oxides, as well as two-dimensional electron gas between two oxide insulators. Indeed, interfaces between perovskite oxides - e.g. the LaAlO3/SrTiO3 \u2013 have shown properties at the nanometer scale that are qualitatively different from their single building blocks, allowing one to engineer novel functionalities through the growth of epitaxial heterostructures. Nevertheless, both atomic and electronic reconstructions could be present in oxide interfaces when a polar discontinuity occurs at the junction and the possibility to probe non-destructively the cation depth profiles can provide further insight into the oxide heterointerface physics. This is also true for less-ordered systems - i.e. amorphous thin films - which are playing a key role in the development of new architectures in photovoltaic applications, such as the CdxSnyOz/TiO2 heterojunction. In this Thesis, the combination of chemical and structural information on a local scale (i.e. at the interface and the nearby few atomic layers) has been obtained by combining an effective modeling of angle-resolved x-ray photoemission data, with synchrotron based electron spectroscopy techniques. It is shown how in oxides the interfacial electronic properties can be driven by complex substitutional effects across the interface, such as stoichiometry gradients, cation vacancies and interdiffusion, as well as by the presence of interfacial/surface oxygen vacancies

Obstructive Sleep Apnea Syndrome: From Phenotype to Genetic Basis

Obstructive sleep apnea syndrome (OSAS) is a complex chronic clinical syndrome, characterized by snoring, periodic apnea, hypoxemia during sleep, and daytime hypersomnolence. It affects 4-5% of the general population. Racial studies and chromosomal mapping, familial studies and twin studies have provided evidence for the possible link between the OSAS and genetic factors and also most of the risk factors involved in the pathogenesis of OSAS are largely genetically determined. A percentage of 35-40% of its variance can be attributed to genetic factors. It is likely that genetic factors associated with craniofacial structure, body fat distribution and neural control of the upper airway muscles interact to produce the OSAS phenotype. Although the role of specific genes that influence the development of OSAS has not yet been identified, current researches, especially in animal model, suggest that several genetic systems may be important. In this chapter, we will first define the OSAS phenotype, the pathogenesis and the risk factors involved in the OSAS that may be inherited, then, we will review the current progress in the genetics of OSAS and suggest a few future perspectives in the development of therapeutic agents for this complex disease entity

Idiopathic sensorineural hearing loss is associated with endothelial dysfunction

Hearing impairment is the most prevalent sensory deficit [1]. Sensorineural hearing loss (SNHL) is the most common type of permanent hearing loss and it occurswhen there is damage to the inner ear (cochlea), or to the nerve pathways fromthe inner ear to the brain.Most of the time, SNHL cannot be medically or surgically corrected. SNHL can result from genetic, environmental, or combined etiologies that prevent normal function of hearing, but, despite detailed investigation, the main cause remains usually unknown. Clinical and experimental studies have shown that ischemia contributes to several SNHL [2], suchas sudden sensoneural hearing loss, presbyacusis and noise-induced hearing loss. All of these SNHL can be related to alteration in blood flow [3]. The aim of the study is finding a relationship between idiopathic SNHL and endothelial dysfunction

A Body of Knowledge and Pedagogy for Global Engineering

Global engineers must be taught to consider the historical and present causes of persistent poverty and systematic barriers to prosperity. Such training will better inform the choices engineers make and help move the engineering sector away from a product and community-level focus towards working to address the root causes of poverty. A framing for Global Engineering has recently been proposed by the Mortenson Center in Global Engineering at the University of Colorado Boulder, building on over 15 years of curricular efforts. Global Engineering, as taught by the Mortenson Center, positions the field as a complement to Global Health and Development Economics while further embracing a historically contextualized and anti-colonial training. </div

Ceramic Water Filter for Point-Of-Use Water Treatment in Developing Countries: Principles, Challenges and Opportunities

Drinking water source contamination poses a great threat to human health in developing countries. Point-of-use (POU) water treatment techniques, which improve drinking water quality at the household level, offer an affordable and convenient way to obtain safe drinking water and thus can reduce the outbreaks of waterborne diseases. Ceramic water filters (CWFs), fabricated from locally sourced materials and manufactured by local labor, are one of the most socially acceptable POU water treatment technologies because of their effectiveness, low-cost and ease of use. This review concisely summarizes the critical factors that influence the performance of CWFs, including (1) CWF manufacturing process (raw material selection, firing process, silver impregnation), and (2) source water quality. Then, an in-depth discussion is presented with emphasis on key research efforts to address two major challenges of conventional CWFs, including (1) simultaneous increase of filter flow rate and bacterial removal efficiency, and (2) removal of various concerning pollutants, such as viruses and metal(loid)s. To promote the application of CWFs, future research directions can focus on: (1) investigation of pore size distribution and pore structure to achieve higher flow rates and effective pathogen removal by elucidating pathogen transport in porous ceramic and adjusting manufacture parameters; and (2) exploration of new surface modification approaches with enhanced interaction between a variety of contaminants and ceramic surfaces