13 research outputs found
The operation, flow conditions and microbial reductions of an intermittently operated, household-scale slow sand filter
Nearly one-fifth of the world\u27s population lacks access to safe, reliable sources of drinking water. Point of use (POU) household water treatment technology allows people to improve the quality of their water by treating it in the home. A promising emerging POU technology is the biosand filter (BSF). The BSF is a household-scale, intermittently operated slow sand filter that maintains a wet media bed containing a schmutzdecke and allows periodic water dosing by the user. Step input chemical tracer tests indicated that the BSF operates at near-plug flow conditions. Six-to-eight week longitudinal challenge studies were conducted with daily charges of surface water spiked with E. coli strain B bacteria, coliphages MS2 and PRD-1 and human enteric virus echovirus type 12. The BSF ripened in a manner similar to conventional SSFs. Flow rate slowed and microbial reductions improved over time with ripening. E. coli reductions were ~90% following filter startup but improved to 95—99.5% over time. Microbial reductions were greater with greater residence time within the filter, especially for water retained in the filter bed overnight. E. coli and echovirus 12 reductions were greater than those of coliphages MS2 and PRD-1
Bacterial contamination of inanimate surfaces and equipment in the intensive care unit
Intensive care unit (ICU)-acquired infections are a challenging health problem worldwide, especially when caused by multidrug-resistant (MDR) pathogens. In ICUs, inanimate surfaces and equipment (e.g., bedrails, stethoscopes, medical charts, ultrasound machine) may be contaminated by bacteria, including MDR isolates. Cross-transmission of microorganisms from inanimate surfaces may have a significant role for ICU-acquired colonization and infections. Contamination may result from healthcare workers' hands or by direct patient shedding of bacteria which are able to survive up to several months on dry surfaces. A higher environmental contamination has been reported around infected patients than around patients who are only colonized and, in this last group, a correlation has been observed between frequency of environmental contamination and culture-positive body sites. Healthcare workers not only contaminate their hands after direct patient contact but also after touching inanimate surfaces and equipment in the patient zone (the patient and his/her immediate surroundings). Inadequate hand hygiene before and after entering a patient zone may result in cross-transmission of pathogens and patient colonization or infection. A number of equipment items and commonly used objects in ICU carry bacteria which, in most cases, show the same antibiotic susceptibility profiles of those isolated from patients. The aim of this review is to provide an updated evidence about contamination of inanimate surfaces and equipment in ICU in light of the concept of patient zone and the possible implications for bacterial pathogen cross-transmission to critically ill patients
Bacterial contamination of inanimate surfaces and equipment in the intensive care unit
Interaction of healthcare worker hands and portable medical equipment: a sequence analysis to show potential transmission opportunities
Bioaerosol concentrations generated from toilet flushing in a hospital-based patient care setting
Transfer Efficiency of Bacteria and Viruses from Porous and Nonporous Fomites to Fingers under Different Relative Humidity Conditions
Radiation-grafted membranes for polymer electrolyte fuel cells: current trends and future directions
Fuel cell technology is one of the key emerging technologies that is currently attracting tremendous effort with the aim to provide alternative environmentally friendly and efficient power sources. The worldwide move away from conventional fossil fuel combustion power generation technologies is driving much of this important research. The replacement of a liquid electrolyte by PEM in such systems has eliminated the corrosion problems and conferred on the system additional advantages such as simplicity of construction, compactness, and quick self-starting at ambient temperatures. The successful performance of these kinds of fuel cell systems depends critically on the role played by the PEM. The second category involves the formation of acid-base complexes that provide a viable alternative for membranes that can maintain high conductivity at elevated temperatures without suffering from dehydration effects