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1.
ACS Appl Mater Interfaces ; 13(14): 16084-16096, 2021 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-33793211

RESUMO

As COVID-19 exemplifies, respiratory diseases transmitted through aerosols or droplets are global threats to public health, and respiratory protection measures are essential first lines of infection prevention and control. However, common face masks are single use and can cause cross-infection due to the accumulated infectious pathogens. We developed salt-based formulations to coat membrane fibers to fabricate antimicrobial filters. Here, we report a mechanistic study on salt-induced pathogen inactivation. The salt recrystallization following aerosol exposure was characterized over time on sodium chloride (NaCl), potassium sulfate (K2SO4), and potassium chloride (KCl) powders and coatings, which revealed that NaCl and KCl start to recrystallize within 5 min and K2SO4 within 15 min. The inactivation kinetics observed for the H1N1 influenza virus and Klebsiella pneumoniae matched the salt recrystallization well, which was identified as the main destabilizing mechanism. Additionally, the salt-coated filters were prepared with different methods (with and without a vacuum process), which led to salt coatings with different morphologies for diverse applications. Finally, the salt-coated filters caused a loss of pathogen viability independent of transmission mode (aerosols or droplets), against both DI water and artificial saliva suspensions. Overall, these findings increase our understanding of the salt-recrystallization-based technology to develop highly versatile antimicrobial filters.


Assuntos
Filtração/instrumentação , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Máscaras , Cloreto de Potássio/química , Cloreto de Sódio/química , Sulfatos/química , Aerossóis , Filtros de Ar , Cristalização , Cinética , Membranas Artificiais , Polipropilenos , Pós , Dispositivos de Proteção Respiratória , Temperatura , Difração de Raios X
2.
Nat Commun ; 12(1): 1871, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33767189

RESUMO

Naturally-occurring membranes in the xylem tissue of gymnosperm sapwood enable its use as an abundantly-available material to construct filters, with potential to facilitate access to safe drinking water in resource-constrained settings. However, the material's behavior as a filter is poorly understood, and challenges such as short shelf life have not been addressed. Here, we characterize the operational attributes of xylem filters and show that the material exhibits a highly non-linear dependence of flow resistance on thickness upon drying, and a tendency for self-blocking. We develop guidelines for the design and fabrication of xylem filters, demonstrate gravity-operated filters with shelf life >2 years, and show that the filters can provide >3 log removal of E. coli, MS-2 phage, and rotavirus from synthetic test waters and coliform bacteria from contaminated spring, tap, and ground waters. Through interviews and workshops in India, we use a user-centric approach to design a prototype filtration device with daily- to weekly-replaceable xylem filters, and uncover indicators of social acceptance of xylem as a natural water filter. Our work enhances the understanding of xylem as a filtration material, and opens opportunities for engineering a diverse range of low-cost, biodegradable xylem-based filtration products on a global scale.


Assuntos
Cedrus/fisiologia , Filtração/métodos , Ginkgo biloba/fisiologia , Pinus/fisiologia , Purificação da Água/métodos , Bacteriófagos/isolamento & purificação , Água Potável/análise , Escherichia coli/isolamento & purificação , Filtração/instrumentação , Humanos , Rotavirus/isolamento & purificação , Purificação da Água/instrumentação , Xilema/fisiologia
4.
Rev Gaucha Enferm ; 42(spe): e20200146, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33787720

RESUMO

OBJECTIVE: To evaluate the protocols on decontamination/reuse of N95 masks available in the literature in times of the Covid-19 pandemic. METHOD: Integrative literature review, in the period from 2010 to 2020, on the databases MEDLINE/PubMed, Science Direct, Cochrane, SAGE journals, Web of Science, Scopus, Embase and Wiley, with the descriptors Masks AND Respiratory protective devices; Mask OR N95 AND Covid-19; N95 AND Respirators; Decontamination AND N95 AND Coronavirus; Facemask OR Pandemic. RESULTS: Twelve studies were included, of which 3 (30.0%) used ultraviolet germicidal irradiation and indicated mask deterioration between 2 and 10 cycles, 4 (40.0%) used hydrogen peroxide vapor, and seal loss varied from 5 to 20 cycles, 4 (33.3%) evaluated the structural integrity of the N95 mask through visual inspection and 6 (54.4%), its filtration efficiency. CONCLUSION: Reuse strategies to overcome a shortage of devices in the face of the pandemic challenge the current concept for good practices in health-product processing.


Assuntos
/epidemiologia , Descontaminação/métodos , Reutilização de Equipamento , Pandemias , Anti-Infecciosos Locais , Desinfetantes , Desinfecção/métodos , Óxido de Etileno , Filtração/instrumentação , Humanos , Peróxido de Hidrogênio , Raios Ultravioleta
5.
PLoS One ; 16(3): e0247575, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33730106

RESUMO

INTRODUCTION: The COVID-19 pandemic has led to widespread shortages of N95 respirators and other personal protective equipment (PPE). An effective, reusable, locally-manufactured respirator can mitigate this problem. We describe the development, manufacture, and preliminary testing of an open-hardware-licensed device, the "simple silicone mask" (SSM). METHODS: A multidisciplinary team developed a reusable silicone half facepiece respirator over 9 prototype iterations. The manufacturing process consisted of 3D printing and silicone casting. Prototypes were assessed for comfort and breathability. Filtration was assessed by user seal checks and quantitative fit-testing according to CSA Z94.4-18. RESULTS: The respirator originally included a cartridge for holding filter material; this was modified to connect to standard heat-moisture exchange (HME) filters (N95 or greater) after the cartridge showed poor filtration performance due to flow acceleration around the filter edges, which was exacerbated by high filter resistance. All 8 HME-based iterations provided an adequate seal by user seal checks and achieved a pass rate of 87.5% (N = 8) on quantitative testing, with all failures occurring in the first iteration. The overall median fit-factor was 1662 (100 = pass). Estimated unit cost for a production run of 1000 using distributed manufacturing techniques is CAD $15 in materials and 20 minutes of labor. CONCLUSION: Small-scale manufacturing of an effective, reusable N95 respirator during a pandemic is feasible and cost-effective. Required quantities of reusables are more predictable and less vulnerable to supply chain disruption than disposables. With further evaluation, such devices may be an alternative to disposable respirators during public health emergencies. The respirator described above is an investigational device and requires further evaluation and regulatory requirements before clinical deployment. The authors and affiliates do not endorse the use of this device at present.


Assuntos
/prevenção & controle , Desenho de Equipamento/instrumentação , Filtração/instrumentação , Pandemias/prevenção & controle , Equipamento de Proteção Individual , Dispositivos de Proteção Respiratória , Ventiladores Mecânicos , Reutilização de Equipamento , Face , Humanos , Teste de Materiais/instrumentação , Exposição Ocupacional/prevenção & controle , Impressão Tridimensional/instrumentação , /patogenicidade
6.
J Prev Med Public Health ; 54(1): 31-36, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33618497

RESUMO

OBJECTIVES: Non-traditional materials are used for mask construction to address personal protective equipment shortages during the coronavirus disease 2019 (COVID-19) pandemic. Reusable masks made from surgical sterilization wrap represent such an innovative approach with social media frequently referring to them as "N95 alternatives." This material was tested for particle filtration efficiency and breathability to clarify what role they might have in infection prevention and control. METHODS: A heavyweight, double layer sterilization wrap was tested when new and after 2, 4, 6, and 10 autoclave sterilizing cycles and compared with an approved N95 respirator and a surgical mask via testing procedures using a sodium chloride aerosol for N95 efficiency testing similar to 42 CFR 84.181. Pressure testing to indicate breathability was also conducted. RESULTS: The particle filtration efficiency for the sterilization wrap ranged between 58% to 66%, with similar performance when new and after sterilizing cycles. The N95 respirator and surgical mask performed at 95% and 68% respectively. Pressure drops for the sterilization wrap, N95 and surgical mask were 10.4 mmH2O, 5.9 mmH2O, and 5.1 mmH2O, respectively, well below the National Institute for Occupational Safety and Health limits of 35 mmH2O during initial inhalation and 25 mmH2O during initial exhalation. CONCLUSIONS: The sterilization wrap's particle filtration efficiency is much lower than a N95 respirator, but falls within the range of a surgical mask, with acceptable breathability. Performance testing of non-traditional mask materials is crucial to determine potential protection efficacy and for correcting misinterpretation propagated through popular media.


Assuntos
Filtração/normas , Máscaras/normas , Filtração/instrumentação , Filtração/estatística & dados numéricos , Humanos , Máscaras/microbiologia , Máscaras/virologia , Exposição Ocupacional/prevenção & controle , Pandemias/prevenção & controle , Equipamento de Proteção Individual/normas , Equipamento de Proteção Individual/estatística & dados numéricos , Esterilização/métodos , Esterilização/normas , Esterilização/estatística & dados numéricos
7.
Enferm Clin ; 31 Suppl 1: S73-S77, 2021 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33487530

RESUMO

The main element of personal protective equipment against the SARS-CoV-2 pandemic are masks, which protect against droplets and aerosols that can remain suspended in the air. The objective of this study is to summarize the existing evidence on the filtration of different materials for the manufacture of masks. A scoping review or exploratory review has been carried out in the PubMEd and Scopus databases, using the terms "respirator", "mask", "facemask", "material", and "tissue", combined with Boolean operators. The results show some of the materials used for the manufacture of masks, both surgical masks and medium-high filtration masks, as well as materials used for the manufacture of household masks. As a conclusion, it is necessary to know the characteristics of the different materials as well as their properties to guarantee an adequate use according to the specific needs in each context, being fundamental the application of particle filtration systems as well as support materials that comply with current recommendations.


Assuntos
/prevenção & controle , Máscaras/normas , /epidemiologia , Celulose/normas , Desenho de Equipamento/métodos , Filtração/instrumentação , Filtração/normas , Pessoal de Saúde , Humanos , Máscaras/provisão & distribução , Pandemias , Equipamento de Proteção Individual/provisão & distribução , Polipropilenos/normas , Eletricidade Estática , Têxteis/normas
8.
J Occup Environ Hyg ; 18(3): 118-127, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33434472

RESUMO

During the beginning of the SARS-CoV-2 pandemic, there was a shortage of masks and respirators for the protection of health care professionals. Masks for noninvasive ventilation (NIV) in combination with viral-proof filters, worn by healthcare workers, could serve as an alternative protection measure. We determined the simulated protection factor (SPF) of such devices in comparison to conventional surgical masks, N95, and FFP3 respirators. Masks and respirators were mounted on a ventilated mannequin head in a test-chamber. Isotonic saline containing 150 MBq 99mTC-DTPA (99mTc-diethylenetriamine pentaacetate (DTPA) was nebulized inside the box. The aerosol had a mass median aerodynamic diameter of 0.6 ± 0.4 µm. SPFs were measured using radioactive DTPA particles in the mannequin test system by calculating the ratio of unfiltered particles (Pu) and filtered particles (Pf) for each tested device (SPF = Pu/Pf). Simulated protection factors were 15.6 ± 3.6 for a ResMed AcuCare mask plus filter, 3.5 ± 0.2 for a ResMed Mirage Quattro FX mask plus filter, 9.5 ± 0.8 for a Loewenstein JOYCEclinc FF mask plus filter, 1.9 ± 0.2 for a surgical mask with a rubber band, 2.7 ± 0.7 for a surgical mask with ribbons, 2.3 ± 0.3 for an FFP3 respirator, and 3.6 ± 1.3 for an N95 respirator. The ResMed AcuCare and the Loewenstein JOYCEclinic FF mask were more effective than any other of the tested devices (p < 0.001). In conclusion, masks normally used for NIV with viral-proof filters can effectively filter respirable particles.


Assuntos
/prevenção & controle , Máscaras , Dispositivos de Proteção Respiratória , Filtração/instrumentação , Manequins , Ventilação não Invasiva/instrumentação , Exposição Ocupacional/prevenção & controle , Pentetato de Tecnécio Tc 99m
9.
J Occup Environ Hyg ; 18(3): 128-138, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33476218

RESUMO

The outbreak of the COVID-19 pandemic is causing a shortage of personal protective equipment (PPE) across the world. As a public health response to control the pandemic, wearing homemade face coverings has been proven as a resort to protect both the wearer and others from droplets and aerosols transmission. Although aerosols and droplets can be removed through these non-medical materials with a series of filtration mechanisms, their filtration performances have not been evaluated in detail. Moreover, many factors, such as the fabric properties and the method of usage, also affect filtration performance. In this study, the size-dependent filtration performances of non-medical materials as candidates for face coverings were evaluated comprehensively. The flow resistance across these filter materials, an indicator of breathability, was also examined. The effect of materials properties, washing and drying cycles, and triboelectric effect on particle filtration was also studied. Results showed that the filtration efficiency varied considerably from 5-50% among fabrics materials due to the material properties, such as density and microscopic structure of the materials. Microfiber cloth demonstrated the highest efficiency among the tested materials. In general, fabric materials with higher grams per square meter (GSM) show higher particle filtration efficiency. The results on washing and drying fabric materials indicated decent reusability for fabric materials. The triboelectric charge could increase the filtration performance of the tested fabric materials, but this effect diminishes soon due to the dissipation of charges, meaning that triboelectric charging may not be effective in manufacturing homemade face coverings.


Assuntos
/prevenção & controle , Filtração/instrumentação , Máscaras , Têxteis , Teste de Materiais/métodos , Dispositivos de Proteção Respiratória
10.
Methods Mol Biol ; 2261: 25-34, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33420982

RESUMO

Effective and reliable protease digestion of biological samples is critical to the success in bottom-up proteomics analysis. Various filter-based approaches using different types of membranes have been developed in the past several years and largely implemented in sample preparations for modern proteomics. However, these approaches rely heavily on commercial filter products, which are not only costly but also limited in membrane options. Here, we present a plug-and-play device for filter assembly and protease digestion. The device can accommodate a variety of membrane types, can be packed in-house with minimal difficulty, and is extremely cost-effective and reliable. Our protocol offers a versatile platform for general proteome analyses and clinical mass spectrometry.


Assuntos
Métodos Analíticos de Preparação de Amostras/instrumentação , Filtração/instrumentação , Membranas Artificiais , Polivinil , Proteínas/análise , Proteômica , Espectrometria de Massas em Tandem , Proteólise , Proteoma
11.
J Dairy Sci ; 104(2): 1846-1854, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33358162

RESUMO

Filter bags facilitate the measurement of amylase-treated neutral detergent fiber (aNDF) and in vitro (IV) undigested aNDF (uNDF) by eliminating the transfer of residues from beakers into filtration crucibles. The objectives of this study were to (1) determine effects of filter bags on recovery of aNDF and (2) evaluate effects of filter bags on IV uNDF. For study 1, 6 samples each of grass hay (GR), alfalfa (AL), and corn silage (CS) were selected. Large standard deviations (SD) of ash-free aNDF (aNDFom) for samples in each forage type indicated compositional diversity (15.1, 7.45, and 12.9% of DM for GR, AL, and CS, respectively), and starch SD for CS was 16.4% of DM. Samples were weighed into Berzelius beakers or filter bags [25-µm pores (F57) or 6-µm pores (F58); Ankom Technology, Macedon, NY] for measurement of aNDF and aNDFom. All samples were extracted with neutral detergent, thermostable α-amylase, and sodium sulfite, and then soaked in boiling water and then acetone. Residues from beakers were filtered through a sea sand-covered GF/D filter (Whatman, Marlborough, MA) in Gooch crucibles (CR). Filter bags were extracted in a pressurized chamber at 100°C. The aNDF values did not differ between F57 and CR, but F58 was greater than CR for CS and AL. For GR, F58 was greater than CR for aNDFom. For study 2, diverse samples with large SD of aNDFom (20.7, 7.45, and 12.9% of DM for GR, AL, and CS, respectively) were weighed as loose powder into medium bottles (LS) or F57 bags, which were weighted to prevent floating. Blended ruminal fluid from 3 steers fed a 30% aNDFom diet was used as inoculum. Three samples of 1 forage type were randomly assigned to 1 of 6 IV runs using both treatments (LS and F57), and 3 bottles of each sample-treatment combination were removed after 12 h and 2 were removed after 120 h to measure uNDF. For LS, residues were extracted as in study 1 for CR. For F57, bags were rinsed in cold water and extracted as described in study 1. After 12 h, uNDF of F57 was greater than LS in CS, AL, and overall types. Ash-free uNDF (uNDFom) after 12 h of F57 was greater than LS in CS and overall types. After 120 h, F57 was greater than LS for uNDF of CS, but no differences were detected for uNDFom. The SD of uNDFom, but not uNDF, was higher after 12 and 120 h for F57 compared with LS. From 6 to 96 h, overall gas production of F57 was less than LS, and F57 was less than LS for CS from 3 to 96 h. Overall, LS gave greater maximum and faster rates of gas production than F57, as did AL and CS, but lag did not vary. Results indicate that filter bags affected aNDF and aNDFom measurement and inhibited fermentation for some materials.


Assuntos
Ração Animal , Fibras na Dieta/análise , Fibras na Dieta/metabolismo , Digestão , Filtração/instrumentação , Animais , Fermentação , Medicago sativa/metabolismo , Poaceae/metabolismo , Rúmen/metabolismo , Sulfitos , Zea mays/metabolismo , alfa-Amilases/metabolismo
12.
Cochrane Database Syst Rev ; 12: CD012467, 2020 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-33314078

RESUMO

BACKGROUND: Acute kidney injury (AKI) is a major comorbidity in hospitalised patients. Patients with severe AKI require continuous renal replacement therapy (CRRT) when they are haemodynamically unstable. CRRT is prescribed assuming it is delivered over 24 hours. However, it is interrupted when the extracorporeal circuits clot and the replacement is required. The interruption may impair the solute clearance as it causes under dosing of CRRT. To prevent the circuit clotting, anticoagulation drugs are frequently used. OBJECTIVES: To assess the benefits and harms of pharmacological interventions for preventing clotting in the extracorporeal circuits during CRRT. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies up to 12 September 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov. SELECTION CRITERIA: We selected randomised controlled trials (RCTs or cluster RCTs) and quasi-RCTs of pharmacological interventions to prevent clotting of extracorporeal circuits during CRRT. DATA COLLECTION AND ANALYSIS: Data were abstracted and assessed independently by two authors. Dichotomous outcomes were calculated as risk ratio (RR) with 95% confidence intervals (CI). The primary review outcomes were major bleeding, successful prevention of clotting (no need of circuit change in the first 24 hours for any reason), and death. Evidence certainty was determined using the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. MAIN RESULTS: A total of 34 completed studies (1960 participants) were included in this review. We identified seven ongoing studies which we plan to assess in a future update of this review. No included studies were free from risk of bias. We rated 30 studies for performance bias and detection bias as high risk of bias. We rated 18 studies for random sequence generation,ààsix studies for the allocation concealment, three studies for performance bias, three studies for detection bias,à nine studies for attrition bias,à14 studies for selective reporting and nine studies for the other potential source of bias, as having low risk of bias. We identified eight studies (581 participants) that compared citrate with unfractionated heparin (UFH). Compared to UFH, citrate probably reduces major bleeding (RR 0.22, 95% CI 0.08 to 0.62; moderate certainty evidence) and probably increases successful prevention of clotting (RR 1.44, 95% CI 1.10 to 1.87; moderate certainty evidence). Citrate may have little or no effect on death at 28 days (RR 1.06, 95% CI 0.86 to 1.30, moderate certainty evidence). Citrate versus UFH may reduce the number of participants who drop out of treatment due to adverse events (RR 0.47, 95% CI 0.15 to 1.49; low certainty evidence). Compared to UFH, citrate may make little or no difference to the recovery of kidney function (RR 1.04, 95% CI 0.89 to 1.21; low certainty evidence). Compared to UFH, citrate may reduceàthrombocytopenia (RR 0.39, 95% CI 0.14 to 1.03; low certainty evidence). It was uncertain whether citrate reduces a cost to health care services because of inadequate data. For low molecular weight heparin (LMWH) versus UFH, six studies (250 participants) were identified. Compared to LMWH, UFH may reduce major bleeding (0.58, 95% CI 0.13 to 2.58; low certainty evidence). It is uncertain whether UFH versus LMWH reduces death at 28 days or leads to successful prevention of clotting. Compared to LMWH, UFH may reduce the number of patient dropouts from adverse events (RR 0.29, 95% CI 0.02 to 3.53; low certainty evidence). It was uncertain whether UFH versus LMWH leads to the recovery of kidney function because no included studies reported this outcome. It was uncertain whether UFH versus LMWH leads to thrombocytopenia. It was uncertain whether UFH reduces a cost to health care services because of inadequate data. For the comparison of UFH to no anticoagulation, one study (10 participants) was identified. It is uncertain whether UFH compare to no anticoagulation leads to more major bleeding. It is uncertain whether UFH improves successful prevention of clotting in the first 24 hours, death at 28 days, the number of patient dropouts due to adverse events, recovery of kidney function, thrombocytopenia, or cost to health care services because no study reported these outcomes. For the comparison ofàcitrate to no anticoagulation,àno completed study was identified. AUTHORS' CONCLUSIONS: Currently,àavailable evidence does not support the overall superiority of any anticoagulant to another. Compared to UFH, citrate probably reduces major bleeding and prevents clotting and probably has little or no effect on death at 28 days. For other pharmacological anticoagulation methods, there is no available data showing overall superiority to citrate or no pharmacological anticoagulation. Further studies are needed to identify patient populations in which CRRT should commence with no pharmacological anticoagulation or with citrate.


Assuntos
Lesão Renal Aguda/terapia , Anticoagulantes/administração & dosagem , Coagulação Sanguínea/efeitos dos fármacos , Obstrução do Cateter , Terapia de Substituição Renal Contínua/instrumentação , Lesão Renal Aguda/mortalidade , Anticoagulantes/efeitos adversos , Viés , Obstrução do Cateter/etiologia , Ácido Cítrico/administração & dosagem , Ácido Cítrico/efeitos adversos , Terapia de Substituição Renal Contínua/efeitos adversos , Terapia de Substituição Renal Contínua/mortalidade , Filtração/instrumentação , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Heparina/administração & dosagem , Heparina/efeitos adversos , Heparina de Baixo Peso Molecular/administração & dosagem , Heparina de Baixo Peso Molecular/efeitos adversos , Humanos , Rim/fisiologia , Pacientes Desistentes do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto , Recuperação de Função Fisiológica/efeitos dos fármacos , Trombocitopenia/prevenção & controle
13.
BMJ Open Respir Res ; 7(1)2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33148778

RESUMO

INTRODUCTION: The COVID-19 pandemic has been characterised by significant in-hospital virus transmission and deaths among healthcare workers. Sources of in-hospital transmission are not fully understood, with special precautions currently reserved for procedures previously shown to generate aerosols (particles <5 µm). Pleural procedures are not currently considered AGPs (Aerosol Generating Procedures), reflecting a lack of data in this area. METHODS: An underwater seal chest drain bottle (R54500, Rocket Medical UK) was set up inside a 60-litre plastic box and connected via an airtight conduit to a medical air supply. A multichannel particle counter (TSI Aerotrak 9310 Aerosol Monitor) was placed inside the box, allowing measurement of particle count/cubic foot (pc/ft3) within six channel sizes: 0.3-0.5, 0.5-1, 1-3, 3-5, 5-10 and >10 µm. Stabilised particle counts at 1, 3 and 5 L/min were compared by Wilcoxon signed rank test; p values were Bonferroni-adjusted. Measurements were repeated with a simple anti-viral filter, designed using repurposed materials by the study team, attached to the drain bottle. The pressure within the bottle was measured to assess any effect of the filter on bottle function. RESULTS: Aerosol emissions increased with increasing air flow, with the largest increase observed in smaller particles (0.3-3 µm). Concentration of the smallest particles (0.3-0.5 µm) increased from background levels by 700, 1400 and 2500 pc/ft3 at 1, 3 and 5 L/min, respectively. However, dispersion of particles of all sizes was effectively prevented by use of the viral filter at all flow rates. Use of the filter was associated with a maximum pressure rise of 0.3 cm H2O after 24 hours of flow at 5 L/min, suggesting minimal impact on drain function. CONCLUSION: A bubbling chest drain is a source of aerosolised particles, but emission can be prevented using a simple anti-viral filter. These data should be considered when designing measures to reduce in-hospital spread of SARS-CoV-2.


Assuntos
Betacoronavirus , Tubos Torácicos , Infecções por Coronavirus/transmissão , Pessoal de Saúde , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Exposição Ocupacional/prevenção & controle , Pneumonia Viral/transmissão , Aerossóis , Drenagem , Filtração/instrumentação , Humanos , Pandemias , Tamanho da Partícula , Material Particulado
14.
JAMA ; 324(16): 1629-1639, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33095849

RESUMO

Importance: Although current guidelines suggest the use of regional citrate anticoagulation (which involves the addition of a citrate solution to the blood before the filter of the extracorporeal dialysis circuit) as first-line treatment for continuous kidney replacement therapy in critically ill patients, the evidence for this recommendation is based on few clinical trials and meta-analyses. Objective: To determine the effect of regional citrate anticoagulation, compared with systemic heparin anticoagulation, on filter life span and mortality. Design, Setting, and Participants: A parallel-group, randomized multicenter clinical trial in 26 centers across Germany was conducted between March 2016 and December 2018 (final date of follow-up, January 21, 2020). The trial was terminated early after 596 critically ill patients with severe acute kidney injury or clinical indications for initiation of kidney replacement therapy had been enrolled. Interventions: Patients were randomized to receive either regional citrate anticoagulation (n = 300), which consisted of a target ionized calcium level of 1.0 to 1.40 mg/dL, or systemic heparin anticoagulation (n = 296), which consisted of a target activated partial thromboplastin time of 45 to 60 seconds, for continuous kidney replacement therapy. Main Outcomes and Measures: Coprimary outcomes were filter life span and 90-day mortality. Secondary end points included bleeding complications and new infections. Results: Among 638 patients randomized, 596 (93.4%) (mean age, 67.5 years; 183 [30.7%] women) completed the trial. In the regional citrate group vs systemic heparin group, median filter life span was 47 hours (interquartile range [IQR], 19-70 hours) vs 26 hours (IQR, 12-51 hours) (difference, 15 hours [95% CI, 11 to 20 hours]; P < .001). Ninety-day all-cause mortality occurred in 150 of 300 patients vs 156 of 296 patients (Kaplan-Meier estimator percentages, 51.2% vs 53.6%; unadjusted difference, -2.4% [95% CI, -10.5% to 5.8%]; unadjusted hazard ratio, 0.91 [95% CI, 0.72 to 1.13]; unadjusted P = .38; adjusted difference, -6.1% [95% CI, -12.6% to 0.4%]; primary adjusted hazard ratio, 0.79 [95% CI, 0.63 to 1.004]; primary adjusted P = .054). Of 38 prespecified secondary end points, 34 showed no significant difference. Compared with the systemic heparin group, the regional citrate group had significantly fewer bleeding complications (15/300 [5.1%] vs 49/296 [16.9%]; difference, -11.8% [95% CI, -16.8% to -6.8%]; P < .001) and significantly more new infections (204/300 [68.0%] vs 164/296 [55.4%]; difference, 12.6% [95% CI, 4.9% to 20.3%]; P = .002). Conclusions and Relevance: Among critically ill patients with acute kidney injury receiving continuous kidney replacement therapy, anticoagulation with regional citrate, compared with systemic heparin anticoagulation, resulted in significantly longer filter life span. The trial was terminated early and was therefore underpowered to reach conclusions about the effect of anticoagulation strategy on mortality. Trial Registration: ClinicalTrials.gov Identifier: NCT02669589.


Assuntos
Lesão Renal Aguda/terapia , Anticoagulantes/administração & dosagem , Ácido Cítrico/administração & dosagem , Terapia de Substituição Renal Contínua/instrumentação , Heparina/administração & dosagem , Lesão Renal Aguda/sangue , Lesão Renal Aguda/mortalidade , Idoso , Anticoagulantes/efeitos adversos , Cálcio/sangue , Ácido Cítrico/efeitos adversos , Terapia de Substituição Renal Contínua/mortalidade , Estado Terminal , Término Precoce de Ensaios Clínicos , Feminino , Filtração/instrumentação , Alemanha , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Heparina/efeitos adversos , Humanos , Infecções/epidemiologia , Estimativa de Kaplan-Meier , Masculino , Tempo de Tromboplastina Parcial , Modelos de Riscos Proporcionais , Fatores de Tempo
15.
Sci Rep ; 10(1): 15665, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973285

RESUMO

The COVID-19 pandemic triggered a surge in demand for facemasks to protect against disease transmission. In response to shortages, many public health authorities have recommended homemade masks as acceptable alternatives to surgical masks and N95 respirators. Although mask wearing is intended, in part, to protect others from exhaled, virus-containing particles, few studies have examined particle emission by mask-wearers into the surrounding air. Here, we measured outward emissions of micron-scale aerosol particles by healthy humans performing various expiratory activities while wearing different types of medical-grade or homemade masks. Both surgical masks and unvented KN95 respirators, even without fit-testing, reduce the outward particle emission rates by 90% and 74% on average during speaking and coughing, respectively, compared to wearing no mask, corroborating their effectiveness at reducing outward emission. These masks similarly decreased the outward particle emission of a coughing superemitter, who for unclear reasons emitted up to two orders of magnitude more expiratory particles via coughing than average. In contrast, shedding of non-expiratory micron-scale particulates from friable cellulosic fibers in homemade cotton-fabric masks confounded explicit determination of their efficacy at reducing expiratory particle emission. Audio analysis of the speech and coughing intensity confirmed that people speak more loudly, but do not cough more loudly, when wearing a mask. Further work is needed to establish the efficacy of cloth masks at blocking expiratory particles for speech and coughing at varied intensity and to assess whether virus-contaminated fabrics can generate aerosolized fomites, but the results strongly corroborate the efficacy of medical-grade masks and highlight the importance of regular washing of homemade masks.


Assuntos
Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Máscaras , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Prevenção Primária/métodos , Dispositivos de Proteção Respiratória , Adolescente , Adulto , Aerossóis , Betacoronavirus , Tosse/virologia , Expiração , Feminino , Filtração/instrumentação , Humanos , Exposição por Inalação , Masculino , Pessoa de Meia-Idade , Prevenção Primária/instrumentação , Adulto Jovem
16.
Nano Lett ; 20(10): 7642-7647, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-32986441

RESUMO

Shortages in the availability of personal protective face masks during the COVID-19 pandemic required many to fabricate masks and filter inserts from available materials. While the base filtration efficiency of a material is of primary importance when a perfect seal is possible, ideal fit is not likely to be achieved by the average person preparing to enter a public space or even a healthcare worker without fit-testing before each shift. Our findings suggest that parameters including permeability and pliability can play a strong role in the filtration efficiency of a mask fabricated with various filter media, and that the filtration efficiency of loosely fitting masks/respirators against ultrafine particulates can drop by more than 60% when worn compared to the ideal filtration efficiency of the base material. Further, a test method using SARS-CoV-2 virion-sized silica nanoaerosols is demonstrated to assess the filtration efficiency against nanoparticulates that follow air currents associated with mask leakage.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Filtração/instrumentação , Máscaras , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Dispositivos de Proteção Respiratória , Têxteis , Aerossóis , Microbiologia do Ar , Betacoronavirus/ultraestrutura , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Fibra de Algodão , Filtração/estatística & dados numéricos , Humanos , Exposição por Inalação , Nanopartículas , Tamanho da Partícula , Permeabilidade , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Dióxido de Silício
17.
ACS Chem Neurosci ; 11(18): 2786-2788, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32870651

RESUMO

Herein, we propose the use of novel adsorbents, namely micelle clay complexes comprising the clay montmorillonite, coupled with activated carbon for effective eradication of neuropathogenic microbes such as SARS-CoV-2 and Naegleria fowleri from water supplies for ablution/nasal irrigation. These can be incorporated easily to water collection devices, i.e., taps and water bottles, in the domestic setting. These filters are low cost, easy to install, and ideal disinfection systems. Such strategies are particularly useful for communities who have lack of access to safe water supplies, rely heavily on water storage tanks, or lack adequate water sanitation facilities, especially in developing countries.


Assuntos
Infecções por Coronavirus/prevenção & controle , Filtração/métodos , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Purificação da Água/métodos , Bentonita , Betacoronavirus , Infecções Protozoárias do Sistema Nervoso Central/prevenção & controle , Carvão Vegetal , Argila , Filtração/instrumentação , Humanos , Naegleria fowleri , Lavagem Nasal , Purificação da Água/instrumentação
19.
Ann Ig ; 32(5): 472-520, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32744582

RESUMO

INTRODUCTION: The health emergency caused by the spread of SARS-COV-2 virus has required the adoption of passive measures against contagion, such as social distancing. The use of filtering masks, of the different types available on the market, such as surgical and facial filtering masks (FFP1, FFP2 and FFP3), is also recommended. OBJECTIVES: The aim of this paper, within the Italian and European regulatory reference framework, is to suggest a rational application of existing methodologies that enable to know and assess the features and/or make a face mask intended to be used by the community. In addition to this, the study aims to provide a correct regulatory framework and useful information for a correct use and disposal of face masks. Another purpose is the assessment of the hygienic, sanitary and regulatory aspects related to the use and disposal of face masks. METHODS: The analysis of filtering masks is based on the review of scientific literature, the state of art of technology and the filtering means/materials available. Reference is made to filtering mechanisms and devices, the testing methods, the technical, manufacturing and performance features, and to the Italian and European regulatory reference framework. Reference is also made to the hygienic, sanitary and regulatory aspects related to the use and disposal of face masks. RESULTS: Surgical masks or, alternatively, filtering masks with a filtration efficiency between 90% and 95% for 3-µm particles, are the most practicable choice with minor contraindications. The reusable type of mask is conceptually superior compared to single-use masks, but cleaning procedures to be followed are quite complex and not always described in a clear way. CONCLUSIONS: The definition of rigorous and repeatable tests on mask filtration capacity, breathability, wearability, duration of use, regeneration, as well as safe disposal methods, are the main way to provide users with correct selection and use criteria. The results must be disclosed and disseminated quickly.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/prevenção & controle , Filtração/instrumentação , Higiene/normas , Máscaras/normas , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Têxteis/normas , Desenho de Equipamento , Europa (Continente) , França , Humanos , Higiene/legislação & jurisprudência , Itália , Máscaras/classificação , Eliminação de Resíduos de Serviços de Saúde/legislação & jurisprudência , Eliminação de Resíduos de Serviços de Saúde/métodos , Eliminação de Resíduos de Serviços de Saúde/normas
20.
J Clin Microbiol ; 58(11)2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32839250

RESUMO

The COVID-19 pandemic has necessitated a multifaceted rapid response by the scientific community, bringing researchers, health officials, and industry together to address the ongoing public health emergency. To meet this challenge, participants need an informed approach for working safely with the etiological agent, the novel human coronavirus SARS-CoV-2. Work with infectious SARS-CoV-2 is currently restricted to high-containment laboratories, but material can be handled at a lower containment level after inactivation. Given the wide array of inactivation reagents that are being used in laboratories during this pandemic, it is vital that their effectiveness is thoroughly investigated. Here, we evaluated a total of 23 commercial reagents designed for clinical sample transportation, nucleic acid extraction, and virus inactivation for their ability to inactivate SARS-CoV-2, as well as seven other common chemicals, including detergents and fixatives. As part of this study, we have also tested five filtration matrices for their effectiveness at removing the cytotoxic elements of each reagent, permitting accurate determination of levels of infectious virus remaining following treatment. In addition to providing critical data informing inactivation methods and risk assessments for diagnostic and research laboratories working with SARS-CoV-2, these data provide a framework for other laboratories to validate their inactivation processes and to guide similar studies for other pathogens.


Assuntos
Betacoronavirus/efeitos dos fármacos , Indicadores e Reagentes/farmacologia , Inativação de Vírus/efeitos dos fármacos , Animais , Betacoronavirus/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/virologia , Filtração/instrumentação , Humanos , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/virologia , Células Vero
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