Respiration Tests Research Articles

Fit Factor Change on Quantitative Fit Testing of Duckbill N95 Respirators with the Use of Safety Goggles.

N95 respirators and safety goggles are important components of personal protective equipment to reduce the spread of airborne infections, such as COVID-19, among healthcare workers. Poor N95 respirator seal may reduce its protective effect, thereby increasing transmission. Quantitative fit testing is an established way of assessing the N95 respirator fit, which provides a quantitative measure for seal, called the fit factor. Duckbill N95 respirators frequently fail the fit test. We hypothesized that using safety goggles with a wraparound elastic headband will increase their fit-factor by reinforcing the seal between the face and the upper margin of the respirator. We studied the effect of safety goggles with a wraparound elastic headband (3M™ Chemical Splash Resistant Goggles, ID 70006982741) on the fit factor of two types of Duckbill N95 respirators (Halyard FLUIDSHIELD*3, Model 99SA070M, and ProShield® N95 Model TN01-11) in 63 healthy volunteers in a nonrandomized, before-and-after intervention study design. The mean fit factor increased from 69.4 to 169.1 increased from 17/63 (27%) to 46/63 (73%) after the intervention (p <0.0001, OR 3 [95% CI = 4.9–1223]). This is the first study to explore the impact of safety goggles on N95 respirator fit. We conclude that the use of safety goggles with a wraparound elastic headband increases the fit factor of the tested Duckbill N95 respirators.How to cite this articleJohns M, Kyaw S, Lim R, Stewart WC, Thambiraj SR, Shehabi Y, et al. Fit Factor Change on Quantitative Fit Testing of Duckbill N95 Respirators with the Use of Safety Goggles. Indian J Crit Care Med 2021;25(9):981–986.

Nipsnap1 – A Novel Thermogenic Regulator

ObjectivesWe aim to discover molecular treatment options to combat obesity by studying a process known as non-shivering thermogenesis (NST). The major objective is to determine if Nipsnap1 can regulate NST in brown adipose tissue (BAT) and evaluate its potential for obesity treatment. Methods1.Identification of Nipsnap1 and loss-of-function study•Unbiased proteomic analysis is performed on BAT isolated mitochondria samples from 6-week-old mice exposed to cold to activate NST (n = 3).•siRNA-mediated knockdown of Nipsnap1 is performed on primary brown adipocytes isolated from mice. Seahorse Bioanalyzer is used for Mitochondria Respiration Test.•Thermogenic tissue-specific Nipsnap1 knockout mice (N1-KO) are generated by crossing floxed Nipsnap1 (N1-Flox) transgenic mice with UCP1-Cre mice.2.Role of Nipsnap1 in thermogenesis•Phenotypical studies in vivo are performed on 6-week-old N1-KO and N1-Flox mice (n = 8). Mice are acclimated in 30°C followed by cold exposure in 4°C for ten days. Rectal temperature is measured.•N1-KO mice metabolism level and locomotive movement are monitored by the Sable Promethion Metabolic Cage system (n = 8). ResultsNipsnap1 displays potent thermogenic properties. By unbiased proteomic analysis, we identify Nipsnap1, which is highly induced when NST is activated and strongly correlates with the NST key protein Uncoupling Protein 1 (UCP1). Nipsnap1 ablation in primary brown adipocytes reveals significant reductions in thermogenic adipose function. siNipsnap1 causes complete ablation of UCP1 protein levels. Moreover, it causes a 50% reduction (P < 0.001) of mitochondrial oxidative capacity and a 40% reduction (P < 0.05) of glycolytic capacity in cells. Nipsnap1 KO mice have impaired NST and reduced energy expenditure in vivo. Under prolonged cold exposure (day 7–10), N1-KO mice exhibit significant defects (day 10, P < 0.05) to maintain body temperature by NST. We demonstrated that the N1-KO mice had a 10% (P < 0.01) reduction in energy expenditure during the active night period after prolonged cold (day 5–8) treatment compared to controls. ConclusionsNipsnap1 plays an essential role in regulating NST. Targeting Nipsnap1 to increase energy expenditure at the molecular level will provide new insights into developing a safe and effective method to combat obesity and metabolic disease. Funding SourcesAgency: NIH; Institute: NIDDK.

Spatial heterogeneity of cutaneous blood flow respiratory-related oscillations quantified via laser speckle contrast imaging.

LSCI technique provides experimental data which can be considered in the context of spatial blood flow coherency. Analysis of vascular tone oscillations gives additional information to ensure a better understanding of the mechanisms affecting microvascular physiology. The oscillations with different frequencies are due to different physiological mechanisms. The reasons for the generation of peripheral blood flow oscillations in the 0.14–0.6 Hz frequency band are as follows: cardio-respiratory interactions, pressure variations in the venous part of the circulatory system, and the effect of the sympathetic nervous system on the vascular tone. Earlier, we described the spatial heterogeneity of around 0.3 Hz oscillations and this motivated us to continue the research to find the conditions for the occurrence of spatial phase synchronization. For this purpose, a number of physiological tests (controlled respiration, breath holder, and venous occlusion tests) which influence the blood flow oscillations of 0.14–0.6 Hz were considered, an appropriate measurement system and the required data processing algorithms were developed. At spontaneous respiration, the oscillations with frequencies around 0.3 Hz were stochastic, whereas all the performed tests induced an increase in spatial coherence. The protocols and methods proposed here can help to clarify whether the heterogeneity of respiratory-related blood flow oscillations exists on the skin surface.

Effect of Reduction Mammoplasty on Pulmonary Function Tests: A Systematic Review.

In patients with breast hypertrophy, excessive breast weight applies pressure on the thorax, which may disrupt the normal breathing. The purpose of this study is to evaluate the impact of the breast hypertrophy and reduction mammoplasty on respiratory function. A comprehensive search of 3 databases, PubMed, Ovid, and Scopus databases, was performed. "Mammoplasty" and "respiration or pulmonary function tests" were the keywords used to search for relevant articles. Ten studies involving 280 patients with breast hypertrophy were included in the final review. Seven articles demonstrated an increase in at least 1 pulmonary function test value after the surgery. This systematic review revealed that, preoperatively, pulmonary function test values of the patients are usually in the normal range. Nonetheless, reduction mammoplasty still improves lung function parameters. Additionally, patients with respiratory complaints felt improvement in their symptoms after the surgery. However, future studies are needed, as heterogeneity among studies was observed.

Quantitative fit testing of filtering face-piece respirators during the COVID-19 pandemic reveals anthropometric deficits in most respirators available in Iran.

PurposeFrontline health care workers (HCWs) must wear a standard N95 or FFP2 respirator during worldwide pandemics of respiratory diseases including COVID-19 to protect against airborne infectious pathogens when performing care activities. This study aimed to quantitatively investigate the fit of most of the common FFRs used during the COVID-19 pandemic in Iran.MethodsA total of 37 volunteers were fit tested in 20 selected FFRs in a randomized order. The selected FFRs were underwent quantitative fit testing by PortaCount® model 8038. To determine the effects of face sizes on respirator fit, the participants’ facial dimensions were measured using a digital caliper.ResultsThe rate of passing fit tests for the studied FFRs were surprisingly low with 11 out of 20 FFRs having less than 10% passing fit tests and the best performers having only 43% and 27% passing fit tests (brands 2 and 20, respectively). Cup-shaped respirators provided significantly greater fit than the vertical flat-fold ones (p < 0.001). A significantly different FFs were found among the respirator brands (F = 13.60, p < 0.001).ConclusionOverall, unacceptably low fit factors were obtained from the studied FFRs. The main reasons for this are suspected to single size and style for each studied FFR. It confirms the importance and requirement of the proper respirator selection in that way fitted optimally into facial dimensions, appropriate usage, and properly performing the fit testing procedure. A unique fit test panel should be developed to guide respirator wearers in selecting the appropriate FFR for their specific face sizes.

Effect of initial moisture content and sample storage duration on compost stability using the ORG0020 dynamic respiration test

Biological tests are widely used to assess composting process status and finished material stability. Although compost stability is known to be influenced by moisture content (MC) and storage duration, there is a lack of data supporting boundary limits for standardised testing. Using the ORG0020 dynamic respiration test we assessed the stability of materials from different commercial composting sites processing only green waste or mixed green and food waste. Samples were tested at three different MC following adjustment with the ‘fist’ test within the range 40–60%. The results showed manipulation of MC within this range could have significant impact on measured stability for some but not all samples. Two samples reported significantly higher activity when MC was manipulated from ~50% to ~60%. For storage duration, samples showed significant decrease in measured activity over several weeks of cold storage. However, there was no significant difference in stability for samples tested up to nine days from receipt. The results of this research will support decisions relating to the boundary limits for moisture content and storage time for the ORG0020 test. The results will also provide insight to the wider range of biological tests used to assess compost stability.

Qualitative fitting characteristics of elastomeric half face-piece respirators using Isoamyl acetate agent.

To examine the fit testing of elastomeric half face-piece respirators (EHRs), a total of 41 candidates were randomly assigned into seven EHRs equipped with organic vapor (OV) cartridges which were commonly used in the Iranian industrial workplaces. The qualitative fitting into the facial dimensions was assessed using the Allegro Isoamyl Acetate fit test kit. While the studied EHRs showed very low passing fit testing rates, the 3M, AoSafety (Medium), and AoSafety (Large) had the highest passing rates with 22.0%, 14.60%, and 9.76%, respectively. The AoSafety (All sizes) delivered a higher passing fit test rate than the 3M brand (29.30 vs. 22.0%). The one size fits all respirators including the DUO and Climax showed lower proportions of passing fit tests compared with AoSafety three-size system brands (2.40% and 4.90% vs. 29.30%). Low fit test passing rates were determined among different respirators. The respirators with various sizes and styles had more opportunities for different wearers to pass the fit test than single size models. The initial and annual fit testing requirements shall be developed by local government. Also, the manufacturers are required to pay attention to respirator features and subject characteristics during the production to obtain satisfactory protection for the end-users.

Filtering efficiency measurement of respirators by laser-based particle counting method

Respirators are one of the most useful personal protective equipment which can effectively limit the spreading of coronavirus (COVID-19). There are a worldwide shortage of respirators, melt-blown non-woven fabrics, and respirator testing possibilities. An easy and fast filtering efficiency measurement method was developed for testing the filtering materials of respirators. It works with a laser-based particle counting method, and it can determine two types of filtering efficiencies: Particle Filtering Efficiency (PFE) at given particle sizes and Concentration Filtering Efficiency (CFE) in the case of different aerosols. The measurement method was validated with different aerosol concentrations and with etalon respirators. Considerable advantages of our measurement method are simplicity, availability, and the relatively low price compared to the flame-photometer based methods. The ability of the measurement method was tested on ten different types of Chinese KN95 respirators. The quality of these respirators differs much, only two from ten reached 95% filtering efficiency.

Distribution of low quality filtering facepiece respirators during the COVID-19 pandemic: an independent analysis of the situation in Switzerland.

SARS-CoV-2 is a respiratory virus. Transmission occurs by droplets, contact and aerosols. In medical settings, filtering facepiece (FFP) respirators are recommended for use by personnel exposed to aerosol-generating procedures. During the COVID-19 pandemic, the demand for FFP respirators exceeded their supply worldwide and low-quality products appeared on the market, potentially putting healthcare workers at risk. To raise awareness about variations in quality of imported FFP respirators in Switzerland during the COVID-19 pandemic, to draw attention to the current directives regulating the market launch of FFP respirators in Switzerland, to provide practical support in identifying suspicious products or documents and, finally, to offer strategies aimed at reducing the distribution of low-quality FFP respirators in the future. Three Swiss laboratories, Spiez Laboratory and Unisant&eacute; in partnership with TOXpro SA individually set up testing procedures to evaluate aerosol penetration and fit testing of FFP respirators imported into Switzerland during COVID-19 pandemic. Additionally, Spiez Laboratory visually inspected the products, examined the certification documents and crosschecked the product information with international databases. Between 31 March and 15 June 2020, 151 FFP respirators were analysed. The initial assessment performed before testing allowed a reduction of up to 35% in the number of FFP respirators sent to Spiez Laboratory for evaluation, for which product information found to be faulty. After filtration efficiency evaluation and fit testing, 52% and 60% of all products tested by Spiez Laboratory and Unisant&eacute;-TOXpro SA, respectively, did not meet the minimum performance requirements established independently by the three Swiss laboratories. The demand for FFP respirators exceeded the supply capacity from established suppliers of the Swiss market. New production and import channels emerged, as did the number of poor-quality FFP respirators. FFP respirators remaining in stocks should be checked for conformity before being used, or eliminated and replaced if quality does not meet standards.

Comparison of Dry Matter Loss Rates from Static and Dynamic Grain Respiration Measurement Systems for Soybeans at 18% Moisture Content and 30°C

HighlightsDesign, description, and comparison of static (S) and dynamic (D) grain respiration measurement systems (GRMS).No differences were detected between dry matter loss rates (vDML) from S-GRMS and D-GRMS for soybeans at 18% moisture content and 30°C stored for 20 d.Literature reports variable vDML estimates for soybeans stored in S-GRMS and D-GRMS; more studies should be conducted with a wider range of storage conditions before developing maximum allowable safe storage time guidelines.Abstract. Time to reach 0.5% dry matter loss (DML) is the estimated maximum allowable storage time (MAST) for shelled corn and has been suggested for use with other grains. Respiration studies have reported various estimates of this threshold depending on the type of grain respiration measurement system (GRMS) and storage conditions tested. The objectives of this study were (1) to design and evaluate two GRMS in which oxygen needed for respiration was limited in a static system (S-GRMS) or continuously supplied in a dynamic system (D-GRMS) during storage and (2) to compare the effects of GRMS on DML rates (vDML) for 18% moisture content soybeans stored at 30°C for 20 d. In this study, S-GRMS and D-GRMS units were designed to conduct respiration tests. Respired CO2 (mg CO2) was measured over time and used to calculate the specific mass of respired CO2 (mg CO2 kg-1 d.b. beans) and subsequent DML (%) using stoichiometric ratios from the respiration chemical reaction. DML rates, vDML (% d-1), were estimated by least squares linear regression of DML and time data. Four replications of respiration tests were conducted in each GRMS. Average estimates of vDML were 0.0157% d-1 and 0.0189% d-1 for S-GRMS and D-GRMS, respectively. Mean vDML from D-GRMS tests was 1.2 times greater than mean vDML from S-GRMS but not statistically different (p = 0.09). However, the coefficient of variation was 8 times greater for D-GRMS than for S-GRMS. More studies with a wider range of storage conditions should be conducted for development of a safety factor between both systems prior to using data from respiration of soybeans in the literature to estimate MAST. Keywords: Dry matter loss, Grain storage, Respiration, Soybeans.

Dead space and weaning from invasive mechanical ventilation in high-altitude residents

Objective: To determine the predictive value of the dead space calculation through the dead space/tidal volume fraction atweaning from invasive mechanical ventilation in critically ill patients at high altitude.Materials and methods: An epidemiological, observational, analytical and prospective study carried out in the Adult IntensiveCare Unit of the Hospital del Norte in the city of El Alto, Bolivia (4,090 m a.s.l.; barometric pressure: 453 mm Hg) from November01, 2016 to March 31, 2017. High-altitude residents under invasive mechanical ventilation were studied. The inclusion criteriawere: a) Altitude residents hospitalized in the Invasive Mechanical Ventilation Therapy Intensive Care Unit. b) Patients with evidence of resolution of the cause that prompted their connection to the invasive mechanical ventilator. c) Patients withpositive weaning criteria and rates. d) Positive spontaneous respiration test. The study variables were the dead space through the Vd/Vt fraction and its relationship with the success or failure of the weaning process from mechanical ventilation. The Vd/Vt fraction was calculated in the study patients and then weaning from invasive mechanical ventilation wasperformed. Patients were divided into two groups according to the need for reintubation and reconnection to themechanical ventilator within 72 hours.Results: Twenty-one (21) patients were included: 7 (33 %) women and 14 men (67 %). The mean age was 41 years with a standard deviation of 22.38 years. Eighteen (18) patients (86 %) succeeded and 3 (14 %) failed in the weaning process from invasive mechanical ventilation. The Vd/Vt values in the success and failure groups were 0.43 and 0.53 (p < 0.011109), respectively, witha sensitivity of 0.61 and specificity of 1; a positive predictive value of 1 and a negative predictive value of 0.3.Conclusions: The calculation of the dead space through the measurement of the dead space/tidal volume fraction predicts the success of weaning of critically ill patients under invasive mechanical ventilation at high altitude.

Evaluation of AccuFIT 9000: A Novel Apparatus for Quantitative Fit Testing of Particulate Respirators.

Various strategies developed for protecting frontline workers and the general public from the novel coronavirus, SARS-CoV-2, largely rely on respiratory protective devices (RPDs), especially considering recent evidence about the aerosol transmission route of COVID-19. Performance of an RPD primarily depends on how well the protective device fits the wearer. Therefore, quantitative fit testing of particulate respirators is crucial for achieving the intended protection level. Millions of fit tests are conducted every year using a US OSHA-accepted standard protocol involving a PortaCount® (TSI Inc., Shoreview, MN, USA) which measures a respirator fit factor. Recently, several alternative fit testing instruments have been developed and introduced to the market. Among them is an AccuFIT 9000 (Kanomax-Japan Inc., Suita-city, Osaka, Japan), which, like the PortaCount®, utilizes the condensation particle counting principle, but features an advanced saturation chamber design allowing for a longer residence time and greater flow stability. It is also claimed to have a more cost-efficient assembly than its predecessors. In this study, the novel AccuFIT apparatus was extensively evaluated against the PortaCount® (the reference instrument) using the traditional standard fit testing protocol and following the American National Standards Institute (ANSI) standard (Z88.10-2010 Annex A2). The evaluation was performed with three types of respirators, N95 filtering facepiece respirator (FFR), P100 FFR, and half-mask elastomeric facepiece, of different models and manufacturers donned on 25 subjects. The comparative testing and analysis showed that the AccuFIT 9000 is capable of identifying an inadequate fit of the tested respirators with a sensitivity 0.95 and specificity of 0.97, which meets the ANSI requirement of ≥0.95. The other ANSI requirements/recommendations were also met. It was concluded that the novel fit testing apparatus demonstrated an acceptable performance and, thus, can be successfully deployed for the quantitative respirator fit testing.

Beige fat is dispensable for the metabolic benefits associated with myostatin deletion

ObjectiveIncreasing muscle mass and activating beige fat both have great potential for ameliorating obesity and its comorbidities. Myostatin null mice have increased skeletal muscle mass and are protected from obesity and its sequelae. Deletion of myostatin has also been suggested to result in the activation of beige adipocytes, thermogenic fat cells with anti-obesity and anti-diabetes properties. It is not known whether beige fat activation contributes to the protection from obesity in myostatin null mice. MethodsTo investigate the role of beige fat activation in the metabolic benefits associated with myostatin deletion, we crossed myostatin null mice to adipocyte-specific PRDM16 knockout mice. We analyzed this new mouse model using molecular profiling, whole mount three-dimensional tissue imaging, tissue respiration, and glucose and insulin tolerance tests in models of diet-induced obesity. ResultsHere, we report that PRDM16 is required for the activation of beige fat in the absence of myostatin. However, we show in both male and female mice that beige fat activation is dispensable for the protection from obesity, glucose intolerance, insulin resistance, and hepatic steatosis mediated by myostatin deletion. ConclusionThese findings demonstrate that increasing muscle mass can compensate for the inactivation of beige fat and raise the possibility of targeting muscle mass as a therapeutic approach to offset the deleterious effects of adipose tissue dysfunction in obesity and metabolic syndrome.

Heat sterilization dramatically reduces filter efficiency of the majority of FFP2 and KN95 respirators

BackgroundShortages in personal protective equipment, especially respiratory protective devices (respirators), occurred during the initial phase of the coronavirus disease 2019 pandemic. Sterilization of used respirators can reduce these shortages. In this study, respirator testing was carried out after a single cycle of sterilization.AimTo determine if steam sterilization and re-use can be applied safely for used respirators.MethodsAn aqueous solution of NaCl (0.02% w/v) was nebulized and passed through a sample of respirator material in a cabinet. Passing particle concentrations were measured directly from the cabinet and via the filter material of the respirator for particles ≥0.3 μm, ≥0.5 μm and ≥1.0 μm in diameter.FindingsOnly three of 10 steam sterilized respirators met the requirement of 94% filtration efficiency.ConclusionHeat sterilization cannot be applied generically for safe re-use of respirators.

Respirators evaluated by fit testing.

FFP2/KN95 respirators can vary greatly in their ability to protect the wearer. Fit testing of respirators should be performed by all healthcare workers at risk for airborne transmitted diseases like #COVID19, #influenza or #tuberculosis https://bit.ly/3lFuwy5

Response of Activated Sludge to Long-Term Nanosilver Input and Changes in Extracellular Polymeric Substances (EPS)

This study investigates the response of activated sludge to continuous nanosilver (AgNPs) input in a large concentration range. In addition to substrate removal, changes taking place in the different fractions of Extracellular Polymeric Substances (EPS), namely, very loosely bound-EPS (VLB-EPS), loosely bound-EPS (LB-EPS), and tightly bound-EPS (TB-EPS), as well as the protein and carbohydrate content of each fraction were examined. At relatively low AgNP concentrations (5 mg/L), production of loosely bound fractions became higher. At AgNP ≥ 12 mg/L, also TB-EPS production was promoted. Seemingly, bacteria were protected from inhibitory effects by regulation of EPS production. Moreover, new proteins emerged in EPS. Respiration tests indicated no effect on substrate removal even at high AgNP concentrations because the nanomaterial lost its effectiveness upon continuous aeration. In WWTPs, AgNP concentrations are normally below 0.8 mg/L. Therefore, no negative impact on substrate removal and no visible changes in EPS production would be expected.

The role of fit testing N95/FFP2/FFP3 masks: a narrative review.

For healthcare workers performing aerosol-generating procedures during the COVID-19 pandemic, well fitted filtering facepiece respirators, for example, N95/FFP2 or N99/FFP3 masks, are recommended as part of personal protective equipment. In this review, we evaluate the role of fit checking and fit testing of respirators, in addition to airborne protection provided by respirators. Filtering facepiece respirators are made of material with sufficient high filter capacity to protect against airborne respiratory viruses. Adequate viral protection can only be provided by respirators that properly fit the wearer's facial characteristics. Initial fit pass rates vary between 40% and 90% and are especially low in female and in Asian healthcare workers. Fit testing is recommended to ensure a proper fit of respirators for the individual healthcare worker so that alternative respirators can be selected if required. Although fit testing is required to comply with respirator standards, it is not performed consistently within all healthcare settings. Fit checking (a self-test) is recommended every time a healthcare worker dons a respirator, but is unreliable in detecting proper fit or leak. Additionally, fit testing has a high educational value and as such is best performed as part of a hospital respiratory protection programme. Whether fit checking alone, as opposed to fit tested and fit checked respirators, provides adequate airborne protection against aerosols containing the SARS-CoV-2 virus and other respiratory viruses remains unknown. While fit testing undoubtedly incurs additional costs, it is still recommended, not only to protect healthcare workers but also as it may reduce overall healthcare cost when considering the potential costs of sickness leave and the associated legal costs of compensation.

Personal protective equipment availability and usage amongst pediatric otorhinolaryngologists during the COVID-19 pandemic: An international survey

ObjectivesTo survey a group of global pediatric otolaryngology specialists to assess their usage and access to personal protective equipment during the COVID-19 pandemic. MethodsA survey of 13 questions was created collecting information on: basic demographics of practice, types of PPE used for procedures of varying aerosolization risk, access to positive air-purifying respirator (PAPR) and patient testing for SARS-CoV-2. Pediatric otolaryngologists were invited to complete the survey via Whatsapp™. Results96 responses were collected from 17 different countries. N95 was the most commonly utilized PPE when dealing with COVID-19 patients (64.2%–81.9% depending on aerosolization risk of the procedure). Significantly higher use of PAPR was noted in high-risk aerosolization generating medical procedures, when compared to other risks. Face covering was used consistently (91.6%). Most respondents (78.1%, n = 75) had access to PAPR or had at least requested it. The majority of patients (56.2%, n = 54) was being tested for SARS-CoV-2 prior to procedures performed in operating rooms (OR); whereas, only 1.1% (n = 1) of clinic patients were tested for SARS-CoV-2 irrespective of the history or symptomatology. ConclusionsMost pediatric otolaryngologists used N95 and some form of face covering (eg. goggles, face shields) when dealing with patients with COVID-19 positive status. PAPR was used in situations of high aerosolization risk. Majority of respondents were screening all patients prior to procedures in the operating room.

Decontamination and Reuse of N95 Respirators with Hydrogen Peroxide Vapor to Address Worldwide Personal Protective Equipment Shortages During the SARS-CoV-2 (COVID-19) Pandemic.

Decontamination and Reuse of N95 Respirators with Hydrogen Peroxide Vapor to Address Worldwide Personal Protective Equipment Shortages During the SARS-CoV-2 (COVID-19) Pandemic.

Laboratory tests for aerobic bioremediation of the contaminated sites in the Czech Republic

Laboratory-scale testing methods applicable to evaluation of contaminated subsurface microbial communities are discussed in relation to their potential in supporting effective site bioremediation. Both culture-dependent and culture-independent techniques are considered here with special emphasis on their capacity to contribute to bioremediation system design, in optimal cases by providing information on contaminant degradation rates. In this regard, microbial soil respiration tests seem to be the most useful tool since microbial soil respiration is a sensitive and easily measurable parameter for determination of metabolic activity within the sample and is closely related to other microbial parameters such as microbial biomass.