24 research outputs found
Enhancement of the Performance of Low-Efficiency HVAC Filters Due to Continuous Unipolar Ion Emission
Inactivation of airborne influenza virus by tea tree and eucalyptus oils
Our previous studies demonstrated that precoating of filter fibers with biologically active tea tree oil (TTO) enhances physical collection efficiency of conventional heating, ventilation, and air conditioning (HVAC) filters, and provides cost effective and rapid inactivation of captured bacterial and fungal particles on the filter surface. The main aim of this study was to investigate the antiviral activity of two natural disinfectants, i.e., TTO and eucalyptus oil (EUO), against the influenza virus captured onto the filter surface. It was found that both tested oils possess strong antiviral properties when used as fiber coating materials, capable of inactivating captured microorganisms within 5-10min of contact on the fiber surface. The antiviral activity of TTO was also successfully challenged in aerosol form by mixing viable airborne viral particles with oil droplets in the rotational aerosol chamber. The results look very promising for further development of virus inactivating procedures and technologies for air quality applications
Antiviral activity of tea tree and eucalyptus oil aerosol and vapour
Our previous studies demonstrated high antiviral efficiency of natural disinfectants, i.e. tea tree oil (TTO) and eucalyptus oil (EUO) on the filter surface. The TTO aerosol challenge as disinfectant showed its high antiviral potential. The main aim of this study was to investigate the antiviral activity of TTO and EUO aerosols in range of concentrations against Influenza A virus and E. coli phage M13. It was found that both tested oils aerosols possess strong antiviral action and capable of inactivating model viruses with efficiency of more than 95% within 5-15. min of exposure. Additionally, the TTO and EUO vapors were also challenged for their antiviral activity. The use of natural disinfectants like TTO and EUO in aerosol form as well as in vapour phase looks very promising for further development of virus inactivating procedures and technologies for air quality applications
Интервальные оценки сбалансированности системы на основе теории конфликтов
The possibility of a study of systems based on the conflict theory is examined in this article. Interval
estimates of a system balance, which consider the conflicting properties of its elements, are suggested. The integrated assessment approach is developed for a complex system in view of time and weight parameters. A numerical example of its use is presented for analyzing of agraph model of an information-analytical system.В статье изучается возможность исследования систем на основе теории конфликтов. Предлагаются интервальные оценки равновесия системы, которые учитывают конфликтующие свойства ее элементов. Развивается интегральный подход к оцениванию сложной системы с точки зрения временных и весовых параметров. Представляется численный пример анализа графовой модели информационно-аналитической систем
Интервальные оценки сбалансированности системы на основе теории конфликтов
The possibility of a study of systems based on the conflict theory is examined in this article. Interval
estimates of a system balance, which consider the conflicting properties of its elements, are suggested. The integrated assessment approach is developed for a complex system in view of time and weight parameters. A numerical example of its use is presented for analyzing of agraph model of an information-analytical system.В статье изучается возможность исследования систем на основе теории конфликтов. Предлагаются интервальные оценки равновесия системы, которые учитывают конфликтующие свойства ее элементов. Развивается интегральный подход к оцениванию сложной системы с точки зрения временных и весовых параметров. Представляется численный пример анализа графовой модели информационно-аналитической систем
Portable automatic bioaerosol sampling system for rapid on-site detection of targeted airborne microorganisms
Bioaerosols could cause various severe human and animal diseases and their opportune and qualitative precise detection and control is becoming a significant scientific and technological topic for consideration. Over the last few decades bioaerosol detection has become an important bio-defense related issue. Many types of portable and stationary bioaerosol samplers have been developed and, in some cases, integrated into automated detection systems utilizing various microbiological techniques for analysis of collected microbes. This paper describes a personal sampler used in conjunction with a portable real-time PCR technique. It was found that a single fluorescent dye could be successfully used in multiplex format for qualitative detection of numerous targeted bioaerosols in one PCR tube making the suggested technology a reliable "first alert" device. This approach has been specifically developed and successfully verified for rapid detection of targeted microorganisms by portable PCR devices, which is especially important under field conditions, where the number of microorganisms of interest usually exceeds the number of available PCR reaction tubes. The approach allows detecting targeted microorganisms and triggering some corresponding sanitary and quarantine procedures to localize possible spread of dangerous infections. Following detailed analysis of the sample under controlled laboratory conditions could be used to exactly identify which particular microorganism out of a targeted group has been rapidly detected in the field. It was also found that the personal sampler has a collection efficiency higher than 90% even for small-sized viruses (>20 nm) and stable performance over extended operating periods. In addition, it was found that for microorganisms used in this project (bacteriophages MS2 and T4) elimination of nucleic acids isolation and purification steps during sample preparation does not lead to the system sensitivity reduction, which is extremely important for development of miniature bioaerosol monitoring instrumentation in the future
Bioaerosol Contamination of Ambient Air as the Result of Opening Envelopes Containing Microbial Materials
A Kunjin replicon virus-like particle vaccine provides protection against ebola virus infection in nonhuman primates
The current unprecedented outbreak of Ebola virus (EBOV) disease in West Africa has demonstrated the urgent need for a vaccine. Here, we describe the evaluation of an EBOV vaccine candidate based on Kunjin replicon virus-like particles (KUN VLPs) encoding EBOV glycoprotein with a D637L mutation (GP/D637L) in nonhuman primates. Four African green monkeys (Cercopithecus aethiops) were injected subcutaneously with a dose of 10(9) KUN VLPs per animal twice with an interval of 4 weeks, and animals were challenged 3 weeks later intramuscularly with 600 plaque-forming units of Zaire EBOV. Three animals were completely protected against EBOV challenge, while one vaccinated animal and the control animal died from infection. We suggest that KUN VLPs encoding GP/D637L represent a viable EBOV vaccine candidate
New Personal Sampler for Viable Airborne Viruses: Feasibility Study
While various sampling methods exist for collecting and enumerating airborne bacteria and fungi, no credible methodology has yet been developed for airborne viruses. A new sampling method for monitoring the personal exposure to bioaerosol particles has recently been developed and evaluated with bacteria and fungi. In this method, bacterial/fungal aerosol is aspirated and transported through a porous medium, which is submerged into a liquid layer. As the air is split into numerous bubbles, the particles are scavenged by these bubbles and effectively removed. The current feasibility study was initiated to evaluate the efficiency of the new personal sampler prototype ("bubbler") with airborne viable viruses. Two common viral strains, Influenza (stress-sensitive) and Vaccinia (robust), were aerosolized in the test chamber and collected by two identical "bubblers" that operated simultaneously for a duration of upto 5 min. A virus maintenance liquid, proven to be the optimum collecting environment for the test organisms, was used as a collection fluid. After sampling, the collecting fluid was analyzed and the viral recovery rate was determined. The overall recovery (affected not only by the sampling but also by the aerosolization and the aerosol transport) was 20% for Influenza virus and 89% for Vaccinia virus. The new sampling method was found feasible for the collection and enumeration of robust airborne viruses