Preface 1.General Considerations 2.Basic Processes in Atomization 3.Drop Size Distributions of Sprays 4.Atomizers 5.Flow in Atomizers 6.Atomizer Performance 7.External Spray Charcteristics 8.Drop Evaporation 9.Drop Sizing Methods Index

Atomization and Sprays

In recent years the outbreak of re-emerging and emerging infectious diseases has been a significant burden on global economies and public health. The growth of population and urbanization along with poor water supply and environmental hygiene are the main reasons for the increase in outbreak of infectious pathogens. Transmission of infectious pathogens to the community has caused outbreaks of diseases such as influenza (A/H5N1), diarrhea (Escherichia coli), cholera (Vibrio cholera), etc throughout the world. The comprehensive treatments of environments containing infectious pathogens using advanced disinfectant nanomaterials have been proposed for prevention of the outbreaks. Among these nanomaterials, silver nanoparticles (Ag-NPs) with unique properties of high antimicrobial activity have attracted much interest from scientists and technologists to develop nanosilver-based disinfectant products. This article aims to review the synthesis routes and antimicrobial effects of Ag-NPs against various pathogens including bacteria, fungi and virus. Toxicology considerations of Ag-NPs to humans and ecology are discussed in detail. Some current applications of Ag-NPs in water-, air- and surface- disinfection are described. Finally, future prospects of Ag-NPs for treatment and prevention of currently emerging infections are discussed.

https://iopscience.iop.org/article/10.1088/2043-6262/4/3/033001/pdf

Silver nanoparticles: synthesis, properties, toxicology, applications and perspectives

http://www.mtpinnacle.com/pdfs/Role-of-hospital-surfaces-in-transmission-of-emerging-health%20care-associated-pathogens.pdf

Role of hospital surfaces in the transmission of emerging health care-associated pathogens: norovirus, Clostridium difficile, and Acinetobacter species.

Nanotechnology refers to the fabrication, characterization, and application of substances in nanometer scale dimensions for various ends. The influence of nanotechnology on the healthcare industry is substantial, particularly in the areas of disease diagnosis and treatment. Recent investigations in nanotechnology for drug delivery and tissue engineering have delivered high-impact contributions in translational research, with associated pharmaceutical products and applications. Over the past decade, the synthesis of nanofibers or nanoparticles via electrostatic spinning or spraying, respectively, has emerged as an important nanostructuring methodology. This is due to both the versatility of the electrospinning/electrospraying process and the ensuing control of nanofiber/nanoparticle surface parameters. Electrosprayed nanoparticles and electrospun nanofibers are both employed as natural or synthetic carriers for the delivery of entrapped drugs, growth factors, health supplements, vitamins, and so on. The role of nanofiber/nanoparticle carriers is substantiated by the programmed, tailored, or targeted release of their contents in the guise of tissue engineering scaffolds or medical devices for drug delivery. This review focuses on the nanoformulation of natural materials via the electrospraying or electrospinning of nanoparticles or nanofibers for tissue engineering or drug delivery/pharmaceutical purposes. Here, we classify the natural materials with respect to their animal/plant origin and macrocyclic, small molecule or herbal active constituents, and further categorize the materials according to their proteinaceous or saccharide nature.

Electrosprayed nanoparticles and electrospun nanofibers based on natural materials: applications in tissue regeneration, drug delivery and pharmaceuticals

Review on heterogeneous photocatalytic disinfection of waterborne, airborne, and foodborne viruses: Can we win against pathogenic viruses?

We studied inactivation and UV disinfection of murine norovirus (MNV) as a surrogate for human norovirus. We investigated the effects of different surface characteristics, temperatures, and NaCl concentrations on MNV survival using both a plaque assay and a real-time TaqMan reverse transcription (RT)-PCR assay. MNV survived more than 40 days on diaper material, on gauze, and in a stool suspension. Compared to inactivation at lower temperatures (−20 and 4°C), inactivation of MNV was greater at higher temperatures (18 and 30°C). On the surface of both gauze and diaper material, there was a 5-log10 reduction after incubation at 30°C in 24 days. MNV survived better in a stool suspension than on the surface of gauze or diaper material. A higher salt concentration increased the rate of inactivation of MNV. In 72 h, <0.3-, 1.5-, and 2.5-log10 reductions in the amount of infectious MNV occurred in distilled water and 0.5 and 1 M NaCl, respectively. We observed only minor reductions in the numbers of viral RNA copies as quantified by real-time TaqMan RT-PCR regardless of the temperature, the salt concentration, or the suspending medium. We also evaluated UV disinfection of infectious MNV with and without TiO2. The amount of MNV was significantly reduced by 254-nm UV with and without TiO2. When 25 mJ/cm2 UV was used, 3.3- and 3.6-log10 reductions in the amounts of infectious MNV occurred with and without TiO2, respectively. Our results demonstrate that MNV can persist in various environmental conditions and can be efficiently controlled by UV disinfection.

/pdf/inactivation-and-uv-disinfection-of-murine-norovirus-with-fagsubuy2t.pdf

Inactivation and UV Disinfection of Murine Norovirus with TiO2 under Various Environmental Conditions

Carbon nanotubes (CNTs) have been widely used in a variety of applications because of their unique structure and excellent mechanical and electrical properties. Additionally, silver (Ag) nanoparticles exhibit broad-spectrum biocidal activity toward many different bacteria, fungi, and viruses. In this study, we prepared Ag-coated CNT hybrid nanoparticles (Ag/CNTs) using aerosol nebulization and thermal evaporation/condensation processes and tested their usefulness for antimicrobial air filtration. Droplets were generated from a CNT suspension using a six-jet collison nebulizer, passed through a diffusion dryer to remove moisture, and entered a thermal tube furnace where silver nanoparticles were generated by thermal evaporation/condensation at ∼980 °C in a nitrogen atmosphere. The CNT and Ag nanoparticle aerosols mixed together and attached to each other, forming Ag/CNTs. For physicochemical characterization, the Ag/CNTs were introduced into a scanning mobility particle sizer (SMPS) for size distribution measurements and were sampled by the nanoparticle sampler for morphological and elemental analyses. For antimicrobial air filtration applications, the airborne Ag/CNT particles generated were deposited continuously onto an air filter medium. Physical characteristics (fiber morphology, pressure drop, and filtration efficiency) and biological characteristics (antimicrobial tests against Staphylococcus epidermidis and Escherichia coli bioaerosols) were evaluated. Real-time SMPS and transmission electron microscopy (TEM) data showed that Ag nanoparticles that were <20 nm in diameter were homogeneously dispersed and adhered strongly to the CNT surfaces. Because of the attachment of Ag nanoparticles onto the CNT surfaces, the total particle surface area concentration measured by a nanoparticle surface area monitor (NSAM) was lower than the summation of each Ag nanoparticle and CNT generated. When Ag/CNTs were deposited on the surface of an air filter medium, the antimicrobial activity against test bacterial bioaerosols was enhanced, compared with the deposition of CNTs or Ag nanoparticles alone, whereas the filter pressure drop and bioaerosol filtration efficiency were similar to those of CNT deposition only. At a residence time of 2 h, the relative microbial viabilities of gram-positive S. epidermidis were ∼32, 13, 5, and 0.9% on the control, CNT-, Ag nanoparticle-, and Ag/CNT-deposited filters, respectively, and those of gram-negative E. coli were 13, 2.1, 0.4, and 0.1% on the control, CNTs, Ag nanoparticles, and Ag/CNTs, respectively. These Ag/CNT hybrid nanoparticles may be useful for applications in biomedical devices and antibacterial control systems.

Preparation of Airborne Ag/CNT Hybrid Nanoparticles Using an Aerosol Process and Their Application to Antimicrobial Air Filtration

Recent advances in volatile organic compounds abatement by catalysis and catalytic hybrid processes: A critical review.

Phage therapy against Pseudomonas aeruginosa infections has received renewed attention owing to the increasing prevalence of antibiotic resistance in this bacterium. Here, we isolated and characterized two new potentially lytic bacteriophages (MPK1 and MPK6), which produced large and clear plaques on P. aeruginosa strain PAO1. Based on their morphology, MPK1 belongs to the Myoviridae, while MPK6 belongs to the Podoviridae. The group B polysaccharide of lipopolysaccharide was required for infection, suggesting that their host spectra are associated with the serotypes of P. aeruginosa strains. Intramuscular and intraperitoneal administration of MPK1 and, to a lesser extent, MPK6 significantly protected mice from mortality caused by PAO1-induced peritonitis-sepsis (P < 0.01). Mice treated with either phage also had lower bacterial burdens in their livers, lungs, and spleens. The antibacterial efficacy of MPK1 and MPK6 was also evaluated based on Drosophila melanogaster systemic infection caused by P. aeruginosa, for which phages were administered by feeding. Both phages significantly delayed the PAO1-induced killing of D. melanogaster (P < 0.001), although MPK1 persisted longer than MPK6 in uninfected D. melanogaster tissue samples. These results suggest that a mini-scale experiment using D. melanogaster infection is valid for evaluating the antibacterial efficacy of phage therapy against P. aeruginosa infections.

Antibacterial Efficacy of Phages against Pseudomonas aeruginosa Infections in Mice and Drosophila melanogaster

Microbial compositions of human and animal feces from South Korea were analyzed and characterized. In total, 38 fecal samples (14 healthy adult humans, 6 chickens, 6 cows, 6 pigs and 6 geese) were analyzed by 454 pyrosequencing of the V2 region of the 16S rRNA gene. Four major phyla, Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes, were identified in the samples. Principal coordinate analysis suggested that microbiota from the same host species generally clustered, with the exception of those from humans, which exhibited sample-specific compositions. A network-based analysis revealed that several operational taxonomic units (OTUs), such as Lactobacillus sp., Clostridium sp. and Prevotella sp., were commonly identified in all fecal sources. Other OTUs were present only in fecal samples from a single organism. For example, Yania sp. and Bifidobacterium sp. were identified specifically in chicken and human fecal samples, respectively. These specific OTUs or their respective biological markers could be useful for identifying the sources of fecal contamination in water by microbial source tracking.

/pdf/analysis-of-human-and-animal-fecal-microbiota-for-microbial-48uuufh8oy.pdf

Jung Eun Lee

Papers

Inactivation and UV Disinfection of Murine Norovirus with TiO2 under Various Environmental Conditions

Preparation of Airborne Ag/CNT Hybrid Nanoparticles Using an Aerosol Process and Their Application to Antimicrobial Air Filtration

Recent advances in volatile organic compounds abatement by catalysis and catalytic hybrid processes: A critical review.

Antibacterial Efficacy of Phages against Pseudomonas aeruginosa Infections in Mice and Drosophila melanogaster

Analysis of human and animal fecal microbiota for microbial source tracking