scholarly journals Characterization of aerosol and assessment of the risk of transmission of SARS-COV-2 VIRUS in a natural thermal cave

2021 ◽  
Vol 312 ◽  
pp. 12004
Author(s):  
Mauro Scungio ◽  
Giulia Parlani
Keyword(s):  
Mechanical Ventilation ◽  
Skin Diseases ◽  
Ventilation System ◽  
Research Work ◽  
Substantial Reduction ◽  
Transmission Risk ◽  
Indoor Environments ◽  
Particle Size Distributions ◽  
Unique Chemical

Thermal caves represent an environment characterized by unique chemical-physical properties, often used by customers for treatment and care of musculoskeletal, respiratory and skin diseases. The recent pandemic caused by COVID-19 has imposed the need to investigate the potential transmission scenario of SARS-CoV-2 virus also in such atypical and poorly studied indoor environments. This research work was carried out inside a natural thermal cave located in Italy where a waterfall of sulfur-sulfate-bicarbonate-alkaline earth mineral thermal water creates a warm-humid environment with 100% humidity and 48°C temperature. A characterization of the aerosol was carried out in terms of number, surface area and mass, as well as particle size distributions. The physical characteristics of the aerosol were measured inside the natural thermal cave and in other immediately adjacent areas in two different days and in two distinct moments by means of an optical spectrometer. The data obtained showed a predominance of particles with a diameter greater than 8 μm, associated with a low ability of penetration in the human respiratory system. Subsequently, through a model recently proposed in scientific literature, it was evaluated the airborne transmission risk of SARS-CoV-2 inside the cave by quantifying the probability of infection due to exposure in a microenvironment in presence of a SARS-CoV-2 infected subject. The infection risk was evaluated for different scenarios obtained combining parameters such as physical, breathing or talking activities of the occupants, simultaneous or non-simultaneous access to the cave and mechanical ventilation activated or non-activated. In terms of the risk of SARS-CoV-2 infection, evaluated under the hypotheses of the model, it was highlighted the decisive effect of the mechanical ventilation system on the risk of contagion: for all the hypothesized scenarios, there is a substantial reduction in the risk of contagion considering the ventilation system active. Furthermore, the adoption of social distancing measures such as non-simultaneous access to the cave makes the risk of contagion extremely low, according to the assumptions underlying the model, even with the mechanical ventilation system not active.

Photocatalytic Degradation and Antibacterial Study of Copper(II) Mustard Thiourea Complex

2020 ◽  
Vol 10 (3) ◽  
pp. 229-242
Author(s):  
Vandana Sukhadia ◽  
Rashmi Sharma ◽  
Asha Meena
Keyword(s):  
Photocatalytic Degradation ◽  
Skin Diseases ◽  
Polar Solvent ◽  
Degradation Kinetics ◽  
Research Work ◽  
Solvent Polarity ◽  
Inhibitory Effect ◽  
Mustard Oil ◽  
Urea Complex ◽  
Pseudo First Order Reaction

Aims: The aim of this research work is to synthesise, study and analyse photocatalytic degradation, kinetics. Background: Copper(II) mustard thio urea complex has been synthesized and characterized through FT-IR, NMR, ESR studies. Objective: Photocatalytic degradation of copper(II) mustard thio urea complex was studied in the presence of ZnO as a catalyst in the solution form, using a non polar solvent benzene and a polar solvent methanol with different compositions. Antibacterial activities of copper(II) complex have also been studied against Staphylococcus aureus. Method: O.D. was measured after different time intervals spectrophotometrically to measure the degradation of the complex. Result: Plot of 2+ log O.D. (absorbance) versus time was plotted and found to be linear. The heterogeneous photocatalysis followed pseudo-first-order reaction kinetics. The present study suggests that the CMT complex shows antibacterial activity at different concentrations. Conclusion: The rate of photocatalytic degradation of CMT complex was studied and analyzed. It has been found that the rate of degradation varies with different parameters like the concentration of complex, the amount of catalyst, light intensity, solvent polarity etc. The CMT complex derived from natural mustard oil has shown an inhibitory effect on the growth of S. aureus which may cause skin diseases.

scholarly journals Effect of Mechanical Ventilation on Accidental Hydrogen Releases—Large-Scale Experiments

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3008
Author(s):  
Agnieszka W. Lach ◽  
André V. Gaathaug
Keyword(s):  
Mechanical Ventilation ◽  
Mass Flow ◽  
Large Scale ◽  
Ventilation System ◽  
Hydrogen Gas ◽  
Forced Ventilation ◽  
British Standard ◽  
Confined Spaces ◽  
Series Of Experiments ◽  
Rate Limit

This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces, such as underground garages. The purpose was to find the mass flow rate limit, hence the TPRD diameter limit, that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway, and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard 315 mm diameter outlet. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzles from different hydrogen reservoir pressures. Both types of mass flow, constant and blowdown, were included in the experimental matrix. The analysis of the hydrogen concentration of the created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases, together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step.

Development and characterization of electrospun curcumin-loaded antimicrobial nanofibrous membranes

2020 ◽  
pp. 004051752092551
Author(s):  
Javeed A Awan ◽  
Saif Ur Rehman ◽  
Muhammad Kashif Bangash ◽  
Fiaz Hussain ◽  
Jean-Noël Jaubert
Keyword(s):  
Biological Activities ◽  
Research Work ◽  
Medical Applications ◽  
Electrospinning Technique ◽  
Naturally Occurring ◽  
Wide Range ◽  
Nanofibrous Membranes ◽  
Antimicrobial Barrier ◽  
Anti Hiv

Curcumin is a naturally occurring hydrophobic polyphenol compound. It exhibits a wide range of biological activities such as antibacterial, anti-inflammatory, anti-carcinogenic, antifungal, anti-HIV, and antimicrobial activity. In this research work, antimicrobial curcumin nanofibrous membranes are produce by an electrospinning technique using the Eudragit RS 100 (C19H34ClNO6) polymer solution enriched with curcumin. The morphology and chemistry of the membrane are analyzed using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Kirby Bauer disk diffusion tests are carried out to examine the antibacterial effectiveness of the membrane. Experimental results show that the nanofibers produced are of uniform thickness morphology and curcumin is successfully incorporated into the nanofibrous mat, while no chemical bonding was observed between curcumin and the polymer. The antimicrobial curcumin nanofibrous membranes can be effectively applied as antimicrobial barrier in a wide variety of medical applications such as wound healing, scaffolds, and tissue engineering.

Airborne bacteria concentrations and related factors at university laboratories, hospital diagnostic laboratories and a biowaste site

2011 ◽  
Vol 64 (3) ◽  
pp. 261-264 ◽  
Author(s):  
Sung Ho Hwang ◽  
Dong Uk Park ◽  
Kwon Chul Ha ◽  
Hyun Woo Cho ◽  
Chung Sik Yoon
Keyword(s):  
Sampling Site ◽  
Ventilation System ◽  
Airborne Bacteria ◽  
Gram Negative Bacteria ◽  
Indoor Environments ◽  
Related Factors ◽  
P Values ◽  
Regular Control ◽  
Number Of Bacteria

AimsTo evaluate concentrations of airborne bacteria in university laboratories, hospital diagnostic laboratories, and a biowaste site in Seoul, Korea. To measure total airborne bacteria (TAB), the authors assessed sampling site, type of ventilation system, weather and detection of Gram-negative bacteria (GNB), indoors and outdoors.MethodAn Andersen one-stage sampler (Quick Take 30; SKC Inc) was used to sample air at a flow rate of 28.3 l/min for 5 min on nutrient medium in Petri dishes located on the impactor. A total of 236 samples (TAB, 109 indoor and nine outdoor; GNB, 109 indoor and nine outdoor) were collected three times in each spot from the 11 facilities to compare airborne bacteria concentrations.ResultsTAB concentrations ranged from undetectable to 3451 CFU/m3 (mean 384 CFU/m3), and GNB concentrations from undetectable to 394 CFU/m3 (mean 17 CFU/m3). TAB concentrations were high in window-ventilated facilities and facilities in which GNB were detected; concentrations were also high when it was rainy (all p values <0.05). TAB concentrations correlated significantly with GNB (r=0.548, p<0.01), number of bacteria species (r=0.351, p<0.01) and temperature (r=0.297, p<0.01). The presence of heating, ventilating, and air conditioning (HVAC), the number of TAB species and the detection of GNB affect TAB concentrations in laboratories.ConclusionsIt is recommended that special attention be given to regular control of indoor environments to improve the air quality of university and hospital laboratories.

Production of Bio Gas from Vegetable and Flowers Wastes Using Anaerobic Digestion

2015 ◽  
Vol 787 ◽  
pp. 803-808 ◽  
Author(s):  
A. Deepanraj ◽  
S. Vijayalakshmi ◽  
J. Ranjitha
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Research Work ◽  
Pressure Gauge ◽  
Pig Manure ◽  
Future Research ◽  
Digital Pressure ◽  
Vegetable Wastes ◽  
Main Component

The present research paper describes about the anaerobic digestion of vegetable (Banana, Cauliflower, potato, and sweet potato) and flower wastes (Rose, sambangi, gulmohar, marigold, golden shower tree, silk tree mimosa) in a 1L capacity of anaerobic digestor using pig manure as an inoculums. The digester was operated in the ratio of 1:1 of substrate to inoculums at RT. The substrate concentrations are varied such as 5%, 7%, and 10% was used and amount of gas produced was analysed using digital pressure gauge. The results obtained showed that, marigold flower had given higher yield of biogas than vegetable wastes and the digestion period was less. The average biogas production potential of withered flowers was observed as 14.36 g/kg in 5 days, where in case of vegetable wastes it was 10.0234 g/kg in 6 days. The study showed that flowers which are available in abundant in India is thrown away within a day, in the environment. These feedstocks are good feed stock for the production of biogas. The generation of biogas from flowers and vegetable waste upholds the concept of waste to wealth in enhancing sustainability of development. The future research work is mainly focused on the characterization of the main component present in the bio-gas using sophisticated instruments.

SSR based molecular profiling of elite cultivars of basmati rice (Oryza sativa L.)

2021 ◽  
Vol 16 (12) ◽  
pp. 55-63
Author(s):  
Ashwani Yadav ◽  
Anubhuti Sharma ◽  
Ashwani Kumar ◽  
Renu Yadav ◽  
Rajendra Kumar
Keyword(s):  
Ssr Markers ◽  
Oryza Sativa L ◽  
Research Work ◽  
Similarity Coefficient ◽  
Basmati Rice ◽  
Bank Management ◽  
Genomic Study ◽  
Leaf Tissues ◽  
Maximum Similarity

The experiment was conducted to assess the available genetic variability amongst Indian Basmati rice and identify co-dominant and reproducible robust simple sequence repeat markers for drought resistance and their utilization in marker assisted selection for developing drought resistant / tolerant aromatic rice cultivars in various parts of India as well as in world. DNA was isolated from fresh and young leaf tissues of 35 cultivars of basmati rice using the CTAB procedure of Doyle and Doyle with slightly modifications. The DNA was further quantified by spectrophotometer at 260 nm and 280 nm. The quality and quantity of DNA were checked by agarose gel electrophoresis. Out of 60 SSR markers, 18 were found to be polymorphic and the rest 42 primers were monomorphic. One of the main purposes of SSR markers in genomic study is the characterization of genetic resources to help gene bank management. The informative (18) SSR markers were capable to discriminate the entire cultivars of basmati rice used in this research work. A total of 52 alleles at 18 loci could be scored. The allelic richness per locus diversified from 2 to 5 with an average of 2.89 alleles per locus. The amplitude of Polymorphism Information Content (PIC) value is 0.066 (RM 1068) to 0.730 (RM 1059) with an average of 0.505. The Jaccard’s similarity coefficient ranged from 0.79 to 0.95. Polymorphic finding content showed a positive correlation (r =0.69) with number of alleles at the SSR locus. However it is recommended that SSR markers can be efficiently utilized for this purpose. The maximum similarity coefficient was observed between Jeerakasab and Kalanamak with a coefficient value of 95% and the minimum similarity was found between Jeerakasab and Pusa basmati-1 with a coefficient value of 79%.

scholarly journals Ventilator-induced diaphragm dysfunction in critical illness

2018 ◽  
Vol 243 (17-18) ◽  
pp. 1331-1339 ◽  
Author(s):  
Yung-Yang Liu ◽  
Li-Fu Li
Keyword(s):  
Oxidative Stress ◽  
Mechanical Ventilation ◽  
Muscle Atrophy ◽  
Structural Damage ◽  
Molecular Mechanisms ◽  
Substantial Reduction ◽  
Mechanical Stretch ◽  
Janus Kinase ◽  
Diaphragm Muscle ◽  
Diaphragm Dysfunction

Mechanical ventilation is an essential intervention for intensive care unit patients with acute lung injury. However, the use of controlled mechanical ventilation in both animal and human models causes ventilator-induced diaphragm dysfunction, wherein a substantial reduction in diaphragmatic force-generating capacity occurs, along with structural injury and atrophy of diaphragm muscle fibers. Although diaphragm dysfunction, noted in most mechanically ventilated patients, is correlated with poor clinical outcome, the specific pathophysiology underlying ventilator-induced diaphragm dysfunction requires further elucidation. Numerous factors may underlie this condition in humans as well as animals, such as increased oxidative stress, calcium-activated calpain and caspase-3, the ubiquitin–proteasome system, autophagy–lysosomal pathway, and proapoptotic proteins. All these alter protein synthesis and degradation, thus resulting in muscle atrophy and impaired contractility and compromising oxidative phosphorylation and upregulating glycolysis associated with impaired mitochondrial function. Furthermore, infection combined with mechanical stretch may induce multisystem organ failure and render the diaphragm more sensitive to ventilator-induced diaphragm dysfunction. Herein, several major cellular mechanisms associated with autophagy, apoptosis, and mitochondrial biogenesis—including toll-like receptor 4, nuclear factor-κB, Src, class O of forkhead box, signal transducer and activator of transcription 3, and Janus kinase—are reviewed. In addition, we discuss the potential therapeutic strategies used to ameliorate ventilator-induced diaphragm dysfunction and thus prevent delay in the management of patients under prolonged duration of mechanical ventilation. Impact statement Mechanical ventilation (MV) is life-saving for patients with acute respiratory failure but also causes difficult liberation of patients from ventilator due to rapid decrease of diaphragm muscle endurance and strength, which is termed ventilator-induced diaphragmatic damage (VIDD). Numerous studies have revealed that VIDD could increase extubation failure, ICU stay, ICU mortality, and healthcare expenditures. However, the mechanisms of VIDD, potentially involving a multistep process including muscle atrophy, oxidative loads, structural damage, and muscle fiber remodeling, are not fully elucidated. Further research is necessary to unravel mechanistic framework for understanding the molecular mechanisms underlying VIDD, especially mitochondrial dysfunction and increased mitochondrial oxidative stress, and develop better MV strategies, rehabilitative programs, and pharmacologic agents to translate this knowledge into clinical benefits.

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