biological contaminants
Recently Published Documents


TOTAL DOCUMENTS

135
(FIVE YEARS 56)

H-INDEX

17
(FIVE YEARS 4)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Ali ◽  
R. Almuzaiqer ◽  
K. Al-Salem ◽  
A. Alabdulkarem ◽  
A. Nuhait

AbstractDue to the COVID-19 pandemic, people were encouraged and sometimes required to wear disposable facemasks, which then are discarded creating an environmental problem. In this study, we aim at investigating novel ideas to recycle wasted facemasks in order to lower the environmental impact. An experimental study has been carried out to investigate the possibility of using discarded masks for thermal insulation and sound absorption. The wasted masks are simulated by new masks, which stripped off the nose clips, elastic ear loops and are heated to 120 °C for one hour to kill any biological contaminants. The masks are also melted to investigate their thermal insulation and sound absorption properties. Results show that the thermal conductivity coefficients of the loose and melted masks are 0.03555 and 0.08683 W/m K, respectively, at room temperature of about 25 °C. Results show also that the sound absorption coefficient for loose masks is above 0.6 for the frequency range 600–5000 Hz. The loose facemasks are found to be thermally stable up to 295 °C, elastic ear loops at 304.7 °C, and the composite (melted) facemasks at 330.0 °C using the thermo-gravimetric analysis. Characterization of the facemask’s three-layer fibers and the composite (melted) samples is obtained using scanning electron microscopy (SEM). The three-point bending test is obtained for the composite specimens showing good values of flexural stress, flexural strain, and flexural elastic modulus. These results are promising about using such discarded masks as new thermal insulation and sound-absorbing materials for buildings replacing the synthetic or petrochemical insulation materials.


Author(s):  
Mohammad Oves ◽  
Mohd Ahmar Rauf

The global spread of multidrug-resistant (MDR) microbial infections is currently one of the most severe risks to global public health, with 10 million fatalities expected by 2050 unless action is taken. Nanotechnology has revolutionized science and medicine. The reliance on nanotechnology is growing. Nanoparticles have distinct properties that improve biological, chemical, and physical properties studied for various uses. A significant area of attention in the synthesis of nanoscale modulators is the utilization of crude formulations, retro-synthesized, and pure chemicals, mainly from herbal sources, with fewer adverse effects. Green chemistry has devised a tangential technique for synthesizing metals and metal oxides to produce nanoparticles. Plant extracts (leaves, stems, and shoots) and microorganisms (bacteria, fungus, and yeast) are used as reducing intermediates to make nanoparticles. Studies in microbiology have shown that nanoparticles kill bacteria, fungi, viruses, and protozoa. These green nanoparticles contain antibacterial, antifungal, and anti-inflammatory effects. Most nanoparticles have high antibacterial properties, indicating they may be used to combat diseases and biological contaminants. These nanoparticles have antibacterial action against pathogenic microorganisms that cause serious illnesses, including multidrug-resistant pathogens. The current research will pave the way for future applications and improved methods for producing nanoparticles, paving the way for an innovative route in nano-life sciences with widespread recognition.


2021 ◽  
Author(s):  
Janina Rahlff ◽  
Till L.V. Bornemann ◽  
Anna Lopatina ◽  
Konstantin Severinov ◽  
Alexander J Probst

Extreme Antarctic conditions provide one of the closest analogues of extraterrestrial environments. Since air and snow samples especially from polar regions yield DNA amounts in the lower picogram range, binning of prokaryotic genomes is challenging and renders studying the dispersal of biological entities across these environments difficult. Here, we hypothesized that dispersal of host-associated bacteriophages (adsorbed, replicating or prophages) across the Antarctic continent can be tracked via their genetic signatures and benefits our understanding of virus and host dispersal across long distances. Phage genome fragments (PGFs) reconstructed from surface snow metagenomes of three Antarctic stations were assigned to four host genomes, mainly Betaproteobacteria including Ralstonia spp. Betaproteobacteria of this genus have been found in Antarctic snow as well as on space-related equipment. We reconstructed the complete genome of a temperate phage with near-complete alignment to a prophage in the reference genome of Ralstonia pickettii 12D. PGFs from different stations were related to each other at the genus level and matched similar hosts. Metagenomic read mapping and nucleotide polymorphism analysis revealed a wide dispersal of highly identical PGFs, 13 of which appeared in seawater from the Western Antarctic Peninsula with up to 5538 km to the snow sampling stations. Our results suggest that host-associated phages, especially of Ralstonia sp. disperse over long distances despite harsh conditions of the Antarctic continent. Due to the additional identification of 14 phages associated with two R. pickettii draft genomes isolated from space equipment, we conclude implications for the spread of biological contaminants in extraterrestrial settings.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 274-274
Author(s):  
Dakota R Discepolo ◽  
Russell Kelley ◽  
Jamie Wayman ◽  
Elizabeth Fuess ◽  
Erin B Perry

Abstract Working canines are often deployed to environments with unknown chemical and biological contaminants. Deployed canines may operate in highly contaminated disaster sites for lengthy periods of time requiring daily decontamination efforts. The skin provides a barrier by retaining moisture and preventing entry by contaminants and pathogens. However, few data exist on the impact of repeated decontamination to the canine skin. The objective of this study was to identify changes in dermal health during and after a 14-day serial decontamination program. Labrador retrievers (n = 8) were decontaminated daily using a dish detergent solution (1:8, detergent:water). Skin measurements were collected weekly for pH, trans-epidermal water loss (TEWL), sebum, and moisture. Additionally, visual assessments were recorded for skin health, coat condition, and dander scores (back and body). Statistical tests were conducted with SAS (version 9.4) with measurements analyzed using a PROC GLM Two Way ANOVA and visual assessments analyzed using PROC FREQ Chi Square test. Significance was set at 5% for all tests. Repeated decontamination significantly increased TEWL (P < 0.0001) through day 16. Sebum content was also impacted by repeated daily decontamination efforts (P = 0.0387). Sebum decreased initially before steadily rising. In contrast, moisture content (P = 0.3842) and pH (P = 0.7462), were unaffected by repeated decontamination. Interestingly, dander scores assessed on the back were worsened by repeated decontamination (P = 0.0222) but dander scores assessed across the whole body were unaffected (P = 0.1804). Coat shine was unaffected by decontamination (P = 0.1156) similar to coat softness (P = 0.3418). Overall coat condition remained unchanged as a result of repeated decontamination efforts (P = 0.9466). These data reveal that daily decontamination impacts dermal function, potentially risks for canines working in contaminated areas. Future work should include investigations into methods for decontamination to mitigate these risks.


2021 ◽  
Vol 7 (10) ◽  
pp. 838
Author(s):  
Guadalupe Hernandez-Ramirez ◽  
Domingo Barber ◽  
Jaime Tome-Amat ◽  
Maria Garrido-Arandia ◽  
Araceli Diaz-Perales

Alternaria alternata is a saprophytic mold whose spores are disseminated in warm dry air, the typical weather of the Mediterranean climate region (from 30° to 45°), with a peak during the late summer and early autumn. Alternaria spores are known to be biological contaminants and a potent source of aeroallergens. One consequence of human exposure to Alternaria is an increased risk of developing asthma, with Alt a 1 as its main elicitor and a marker of primary sensitization. Although the action mechanism needs further investigation, a key role of the epithelium in cytokine production, TLR-activated alveolar macrophages and innate lymphoid cells in the adaptive response was demonstrated. Furthermore, sensitization to A. alternata seems to be a trigger for the development of co-sensitization to other allergen sources and may act as an exacerbator of symptoms and an elicitor of food allergies. The prevalence of A. alternata allergy is increasing and has led to expanding research on the role of this fungal species in the induction of IgE-mediated respiratory diseases. Indeed, recent research has allowed new perspectives to be considered in the assessment of exposure and diagnosis of fungi-induced allergies, although more studies are needed for the standardization of immunotherapy formulations.


Author(s):  
Yun-Gi Lee ◽  
Pureun-Haneul Lee ◽  
Seon-Muk Choi ◽  
Min-Hyeok An ◽  
An-Soo Jang

Air pollutants include toxic particles and gases emitted in large quantities from many different combustible materials. They also include particulate matter (PM) and ozone, and biological contaminants, such as viruses and bacteria, which can penetrate the human airway and reach the bloodstream, triggering airway inflammation, dysfunction, and fibrosis. Pollutants that accumulate in the lungs exacerbate symptoms of respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). Asthma, a heterogeneous disease with complex pathological mechanisms, is characterized by particular symptoms such as shortness of breath, a tight chest, coughing, and wheezing. Patients with COPD often experience exacerbations and worsening of symptoms, which may result in hospitalization and disease progression. PM varies in terms of composition, and can include solid and liquid particles of various sizes. PM concentrations are higher in urban areas. Ozone is one of the most toxic photochemical air pollutants. In general, air pollution decreases quality of life and life expectancy. It exacerbates acute and chronic respiratory symptoms in patients with chronic airway diseases, and increases the morbidity and risk of hospitalization associated with respiratory diseases. However, the mechanisms underlying these effects remain unclear. Therefore, we reviewed the impact of air pollutants on airway diseases such as asthma and COPD, focusing on their underlying mechanisms.


2021 ◽  
Vol 7 (5) ◽  
pp. 935-948
Author(s):  
A. van Huis ◽  
B.A. Rumpold ◽  
H.J. van der Fels-Klerx ◽  
J.K. Tomberlin

An overview is given of the special issue on edible insects covering a number of aspects along the value change. The articles presented cover topics about producing insects both as food for humans and feed for animals, ranging from environmental impact, facility design, (left-over) substrates, the role of microbes, genetics, diseases, nutrition, to insect welfare. Possible health benefits of insects for humans and animals are discussed as well as the potential dangers in terms of allergies and chemical/biological contaminants. Regulatory frameworks are examined and assessed for remaining obstacles. The technologies dealing with the processing and extraction of proteins, lipids, and chitin were also reviewed. Consumers’ perception of insect-derived food products is discussed as well. A unique aspect of this special issue within the ‘Journal of Insects as Food and Feed’ is a first attempt to discuss the economics of the industry. The special issue concludes with a discussion of policy and challenges facing the sector.


Sign in / Sign up

Export Citation Format

Share Document