Indoor, outdoor and ICU Environment monitoring of COVID-19

The disease caused by the SARS-CoV-2 virus, which originated in Wuhan, Hubei Province, China, in December 2019 spread rapidly, causing a high number of deaths worldwide. The difficult ability to contain the transmission of the disease raised doubts about the possible forms of contamination. Studies have shown an increase in new cases of the disease on days when the level of pollution was high, raising questions that pollutants may be carriers of the virus. In this study, we investigated the involvement of fine particulate matter (PM2.5) in virus loading in common circulation (indoor and outdoor) environments and in the intensive care unit (ICU) of a hospital. PM2.5 was collected from May to November 2020, and the collection time per day was 48 to 72 h. After collection, the material was stored at a temperature of -80°C until the moment of analysis. Our results demonstrated that SARS-CoV-2 can be found in fine particulate material (PM2.5), but there is an essential interference of temperature, humidity and UV rays in the preservation of viral RNA.

Analysis of philadelphia aerosol

Size distributions and compositions of atmospheric aerosol are important since they affect such processes as pollutant deposition, visibility reduction, human health, smog formation, and chemical reactions in the atmosphere. Natural and anthropogenic high-temperature combustion sources discharge an abundance of fine particulate material, often with the majority of the mass in the sub-micrometer sized particles. The sub-micrometer particle range is of special interest for source identification because the larger particles are efficiently trapped by the particulate control devices, and the sub-micrometer aerosol exhibits longer residence times in the atmosphere. Insight into the contributing sources to an aerosol population can be gained by investigating the morphology and elemental composition of particles as a function of size.The Philadelphia area is a highly industrialized urban airshed with many discrete sources of aerosol. Philadelphia atmospheric particulate material has been previously characterized with a dichotomous sampler, which produced only two size fractions with a size cutoff at 2.5 μm.

A review of methodology used to measure leaf litter decomposition in lotic environments: Time to turn over an old leaf?

Despite the recognition of the relationship between microbial conditioning and invertebrate feeding, there has been little communication between microbial ecologists and zoologists studying the processing of leaf litter in streams. An appraisal of suitable methods is timely, to encourage workers to critically examine their experimental approach: it is often forgotten that results are determined largely by the methods used. We review some recent studies, emphasizing the application of microbiological and biochemical methods, and discuss some important decisions that must be made in experimental design and implementation. It is recommended that newly fallen, naturally abscissed leaves, bound in leaf packs and tethered to natural substrata, be used in studies attempting to simulate natural leaf decomposition. Drying and leaching leaves under extreme conditions should be avoided. Mass loss should not simply be equated with decomposition; instead, losses of the main types of chemical constituents of plant litter should be quantified. If the aim is to study decomposition rather than merely leaf breakdown, the metabolism of dissolved matter and fine particulate material lost from the decaying leaf must be addressed as well. Appropriate techniques should be used to study microbial assemblages: lipid biomarkers or nucleic-acid methods for assemblage composition, microscopy or biochemical analysis for microbial biomass, [3H]-thymidine or [3H]-leucine methods to determine growth rates. Exponential decay curves and processing coefficients should be used cautiously, especially if sample sizes are small and equal throughout the study.

The Demonstration of Sialic Acid in Kidney Stone Matrix

1. The organic matrices of 12 kidney stones containing calcium and two composed of uric acid were solubilized, with ethylenediaminetetra-acetate for the former and sodium hydroxide for the latter. 2. The solubilized matrices and residual fine particulate material were examined for sialic acid by the thiobarbituric acid method. 3. Sialic acid was found in every stone in either the soluble and/or insoluble material. 4. The identity of sialic acid was confirmed by the absorption spectrum of the colour produced and by its release from the protein by neuraminidase. 5. The presence of sialic acid in all stones despite widely varying composition suggests that it may be passively deposited.