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Plant Disease Jun 2021Pinus thunbergii Parl., known as black pine, is widely distributed all over China. This pine variety can prevent soil desertification and promote soil conservation and...
Pinus thunbergii Parl., known as black pine, is widely distributed all over China. This pine variety can prevent soil desertification and promote soil conservation and is excellent for constructing fast-growing forests and shelter belts. The timber of this species can be used for infrastructure construction and furniture production. In August 2020, needle blight symptoms were found on several trees of black pine in Sichuan Province, China. Further surveys showed that these symptoms are common while the disease incidence is less than 30% which indicated the severity of the disease is mild. The tips of old needles first turn grayish green and developed into brown bands ranging from 1 to 2 mm. To determine the pathogen, 20 needle samples with typical symptoms were disinfected with 75% alcohol, and sections of the tissue were cut from joints of diseased and healthy tissues (visually healthy) with a sterilized scalpel, surface sterilized for 45 seconds in 75% alcohol, soaked for 90 seconds in 1.5% NaCIO, rinsed in sterilized water and dried. Small cut tissues were placed on potato dextrose agar (PDA) at 25℃ for 10 days. Pure cultures were obtained by monosporic isolation. The colonies initially appeared white to cream, yeast-like, and later turned to pink and remained at least 10 days. Conidia were hyaline, smooth-walled, single-celled, and ellipsoidal with variable shape and size, 7.5 to 16 × 3.5 to 7 µm (Zalar et al. 2008). DNA was extracted from the mycelium of the isolate by the cetyltriethylammonium bromide (CTAB) method and amplified through polymerase chain reaction (PCR) with the internal transcribed spacer (ITS) region of rDNA and partial β-tubulin genes of a representative isolate (SC05) were amplified using the ITS1/ITS4 and Bt2a/Bt2b primer pairs, respectively(Wu et al. 2017). The sequences submitted to GenBank (Accession Nos. MW228368 for ITS and MW256762 for β-tubulin) showed high similarity with BLAST sequences of Aureobasidium pullulans (ITS, KR704881 [100%]; β-tubulin, MT671934 [99.49%]). For the pathogenicity test, a conidial suspension was prepared with a concentration of 2.0 × 107 conidia/ml. The suspension was sprayed onto 3 annual seedlings' needles, and the control was sprayed with sterile water. Inoculated and non-inoculated plants were kept in humid chambers in a glasshouse. After 10 days, typical symptoms appeared on inoculated needles, whereas control needles remained symptomless. The fungus, A. pullulans, was reisolated from those lesions, confirming Koch's postulates. No symptoms were observed on control plants. Aureobasidium pullulans, a ubiquitous saprophytic fungus on many fruits and very rarely reported to cause disease on pine needles. Only reported invasion of Ozone-injured needles in P. strobus (Costonis and Sinclair 1972) and needles damaged by acid rain in P. sylvestris (Ranta 1990). To our knowledge, this is the first report of brown spot needle blight on P. thunbergii caused by A. pullulans in China. The disease represents a threat to pine manufactures and more research on the pathogenesis and management is needed. .
PubMed: 34129352
DOI: 10.1094/PDIS-11-20-2435-PDN -
Ultrasonics Sonochemistry Aug 2021Reduction of sanitizer dosage and development of non-immersion disinfection methods have become major focuses of research. Here, we examined the disinfection efficacy of...
Reduction of sanitizer dosage and development of non-immersion disinfection methods have become major focuses of research. Here, we examined the disinfection efficacy of combining gaseous ozone (4 and 8 ppm) with aerosolized oxidizing sanitizer [sodium hypochlorite (SH, 100 and 200 ppm)] and aerosolized organic acid [acetic acid (AA, 1% and 2%) and lactic acid (LA, 1% and 2%)]. Notably, 1% AA and 4 ppm gaseous ozone were ineffective for disinfecting Salmonella Typhimurium, and treatment with 1% AA + 8 ppm ozone caused browning of lettuce leaves and stimulated increases in aerobic mesophilic count (AMC), aerobic psychrotrophic count (APC), S. Typhimurium, and Escherichia coli O157:H7. Treatment with 2% LA + 8 ppm ozone resulted in the lowest S. Typhimurium, E. coli O157:H7, Listeria monocytogenes, AMC, APC, and molds and yeasts during storage (0-7 days at 4 °C). Quality analysis indicates that LA + 8 ppm ozone and SH + 8 ppm ozone did not negatively affect L*, a*, b*, polyphenolic content, weight loss, and sensory properties; however, the levels of two individual phenolic compounds (3,4-dihydroxybenzoic acid and vanillin), responsible for phenylpropanoid synthesis, were significantly increased after treatment with 2% LA + 8 ppm ozone. These findings provided insights into the use of LA combined with gaseous ozone for application in disinfecting fresh produce.
Topics: Aerosols; Disinfection; Food Microbiology; Lactuca; Ozone; Polyphenols; Taste; Ultrasonic Waves
PubMed: 34126525
DOI: 10.1016/j.ultsonch.2021.105622 -
Scientific Reports Jun 2021The COVID-19 crisis has taken a significant toll on human life and the global economy since its start in early 2020. Healthcare professionals have been particularly...
The COVID-19 crisis has taken a significant toll on human life and the global economy since its start in early 2020. Healthcare professionals have been particularly vulnerable because of the unprecedented shortage of Facepiece Respirators (FPRs), which act as fundamental tools to protect the medical staff treating the coronavirus patients. In addition, many FPRs are designed to be disposable single-use devices, creating an issue related to the generation of large quantities of non-biodegradable waste. In this contribution, we describe a plasma-based decontamination technique designed to circumvent the shortages of FPRs and alleviate the environmental problems posed by waste generation. The system utilizes a Dielectric Barrier Discharge (DBD) to generate ozone and feed it through the fibers of the FPRs. The flow-through configuration is different than canonical ozone-based sterilization methods, in which the equipment is placed in a sealed ozone-containing enclosure without any flow through the mask polymer fibers. We demonstrate the rapid decontamination of surgical masks using Escherichia coli (E. coli) and Vesicular Stomatitis Virus (VSV) as model pathogens, with the flow-through configuration providing a drastic reduction in sterilization time compared to the canonical approach. We also demonstrate that there is no deterioration in mask structure or filtration efficiency resulting from sterilization. Finally, we show that this decontamination approach can be implemented using readily available tools, such as a plastic box, a glass tube, few 3D printed components, and the high-voltage power supply from a plasma globe toy. The prototype assembled for this study is portable and affordable, with effectiveness comparable to that of larger and more expensive equipment.
PubMed: 34112900
DOI: 10.1038/s41598-021-91735-w -
The Science of the Total Environment Oct 2021Due to the spread of coronavirus disease 2019 (COVID-19), large amounts of antivirals were consumed and released into wastewater, posing risks to the ecosystem and human...
Due to the spread of coronavirus disease 2019 (COVID-19), large amounts of antivirals were consumed and released into wastewater, posing risks to the ecosystem and human health. Ozonation is commonly utilized as pre-oxidation process to enhance the disinfection of hospital wastewater during COVID-19 spread. In this study, the transformation of ribavirin, antiviral for COVID-19, during ozone/PMS‑chlorine intensified disinfection process was investigated. •OH followed by O accounted for the dominant ribavirin degradation in most conditions due to higher reaction rate constant between ribavirin and •OH vs. SO• (1.9 × 10 vs. 7.9 × 10 M s, respectively). During the O/PMS process, ribavirin was dehydrogenated at the hydroxyl groups first, then lost the amide or the methanol group. Chloride at low concentrations (e.g., 0.5- 2 mg/L) slightly accelerated ribavirin degradation, while bromide, iodide, bicarbonate, and dissolved organic matter all reduced the degradation efficiency. In the presence of bromide, O/PMS process resulted in the formation of organic brominated oxidation by-products (OBPs), the concentration of which increased with increasing bromide dosage. However, the formation of halogenated OBPs was negligible when chloride or iodide existed. Compared to the O/HO process, the concentration of brominated OBPs was significantly higher after ozonation or the O/PMS process. This study suggests that the potential risks of the organic brominated OBPs should be taken into consideration when ozonation and ozone-based processes are used to enhance disinfection in the presence of bromide amid COVID-19 pandemic.
Topics: Antiviral Agents; COVID-19; Disinfection; Ecosystem; Humans; Hydrogen Peroxide; Oxidation-Reduction; Ozone; Pandemics; Ribavirin; SARS-CoV-2; Water Pollutants, Chemical; Water Purification
PubMed: 34091342
DOI: 10.1016/j.scitotenv.2021.148030 -
Journal of Conservative Dentistry : JCD 2020The present study aimed to individually evaluate and compare the aerobic and anaerobic antibacterial activity of extract, aqueous ozone, diode laser, and 3% sodium...
AIM
The present study aimed to individually evaluate and compare the aerobic and anaerobic antibacterial activity of extract, aqueous ozone, diode laser, and 3% sodium hypochlorite (NaOCl) as root canal irrigants.
MATERIALS AND METHODS
Forty-eight patients were selected and randomly allocated to one of the four groups ( = 12 each) according to the irrigant to be used in each group. For each included tooth, the preirrigation and postirrigation (after irrigation with the test solution) samples were collected through sterile paper points and microbial culturing was done by swabbing on blood agar plates followed by incubation for aerobic and anaerobic bacteria.
STATISTICAL ANALYSIS
Manual colony-forming units counting were done, and statistical analysis was performed. Analysis of variance (one-way) followed by test was performed as a parametric test to compare the difference between the groups for both aerobic and anaerobic bacteria.
RESULTS
All the groups showed a statistically significant reduction in bacteria ( < 0.05). However, between the groups, the maximum reduction was seen with 3% NaOCl followed by diode laser, extract, and least by aqueous ozone.
CONCLUSION
extract, aqueous zone, diode laser, and 3% NaOCl showed significant antibacterial activity against aerobic and anaerobic bacteria.
PubMed: 34083912
DOI: 10.4103/JCD.JCD_405_20 -
International Journal of Environmental... May 2021The purpose of this study was to develop a simple electrostatic apparatus to precipitate virus particles spread via droplet transmission, which is especially significant...
The purpose of this study was to develop a simple electrostatic apparatus to precipitate virus particles spread via droplet transmission, which is especially significant in the context of the recent coronavirus disease 2019 (COVID-19) pandemic. The bacteriophage φ6 of was used as a model of the COVID-19 virus because of its similar structure and safety in experiments. The apparatus consisted of a spiked, perforated stainless plate (S-PSP) linked to a direct-current voltage generator to supply negative charge to the spike tips and a vessel with water (G-water) linked to a ground line. The S-PSP and G-water surface were paralleled at a definite interval. Negative charge supplied to the spike tips positively polarised the G-water by electrostatic induction to form an electric field between them in which ionic wind and negative ions were generated. Bacteriophage-containing water was atomised with a nebuliser and introduced into the electric field. The mist particles were ionised by the negative ions and attracted to the opposite pole (G-water). This apparatus demonstrated a prominent ability to capture phage-containing mist particles of the same sizes as respiratory droplets and aerosols regardless of the phage concentration of the mist particles. The trapped phages were successfully sterilised using ozone bubbling. Thus, the present study provides an effective system for eliminating droplet transmission of viral pathogens from public spaces.
Topics: Aerosols; COVID-19; Humans; Pandemics; SARS-CoV-2; Static Electricity; Virion
PubMed: 34066356
DOI: 10.3390/ijerph18094934 -
Antimicrobial Resistance and Infection... May 2021With the current SARS-CoV-2 pandemic, many healthcare facilities are lacking a steady supply of masks worldwide. This emergency situation warrants the taking of...
BACKGROUND
With the current SARS-CoV-2 pandemic, many healthcare facilities are lacking a steady supply of masks worldwide. This emergency situation warrants the taking of extraordinary measures to minimize the negative health impact from an insufficient supply of masks. The decontamination, and reuse of healthcare workers' N95/FFP2 masks is a promising solution which needs to overcome several pitfalls to become a reality.
AIM
The overall aim of this article is to provide the reader with a quick overview of the various methods for decontamination and the potential issues to be taken into account when deciding to reuse masks. Ultraviolet germicidal irradiation (UVGI), hydrogen peroxide, steam, ozone, ethylene oxide, dry heat and moist heat have all been methods studied in the context of the pandemic. The article first focuses on the logistical implementation of a decontamination system in its entirety, and then aims to summarize and analyze the different available methods for decontamination.
METHODS
In order to have a clear understanding of the research that has already been done, we conducted a systematic literature review for the questions: what are the tested methods for decontaminating N95/FFP2 masks, and what impact do those methods have on the microbiological contamination and physical integrity of the masks? We used the results of a systematic review on the methods of microbiological decontamination of masks to make sure we covered all of the recommended methods for mask reuse. To this systematic review we added articles and studies relevant to the subject, but that were outside the limits of the systematic review. These include a number of studies that performed important fit and function tests on the masks but took their microbiological outcomes from the existing literature and were thus excluded from the systematic review, but useful for this paper. We also used additional unpublished studies and internal communication from the University of Geneva Hospitals and partner institutions.
RESULTS
This paper analyzes the acceptable methods for respirator decontamination and reuse, and scores them according to a number of variables that we have defined as being crucial (including cost, risk, complexity, time, etc.) to help healthcare facilities decide which method of decontamination is right for them.
CONCLUSION
We provide a resource for healthcare institutions looking at making informed decisions about respirator decontamination. This informed decision making will help to improve infection prevention and control measures, and protect healthcare workers during this crucial time. The overall take home message is that institutions should not reuse respirators unless they have to. In the case of an emergency situation, there are some safe ways to decontaminate them.
Topics: COVID-19; Decontamination; Equipment Reuse; Ethylene Oxide; Health Personnel; Humans; Hydrogen Peroxide; N95 Respirators; SARS-CoV-2; Steam; Ultraviolet Rays
PubMed: 34051855
DOI: 10.1186/s13756-021-00921-y -
APMIS : Acta Pathologica,... Jul 2021The unexpected pandemic with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has challenged the healthcare sector as regards preventing and controlling the... (Review)
Review
The unexpected pandemic with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has challenged the healthcare sector as regards preventing and controlling the virus from spreading between patients and hospital personnel. The massive spread of the pandemic has led state authorities to introduce restrictions on society and public behavior unprecedented in modern times. First, we describe the Danish effort regarding standard precautions, personal protective equipment, and disinfection in the healthcare setting with Denmark as an example. As regards, the number of coronavirus disease 2019 (COVID-19)-related hospital submissions, deaths, and infected healthcare workers in Denmark is not the hardest hit country compared with others. This cannot be explained by the hardness of the restrictions alone. Several aspects concerning the person-to-person spread of SARS-CoV-2 are not fully understood and require more experimental studies. The dogma is that virus transmission happens through either respiratory droplets or contact routes. However, it is likely not the whole truth, as we describe scenarios where droplets and/or direct contact cannot alone explain how all patients were infected. Aspects of the physiology of airborne transmission are considered, as several parameters are in play beyond particle size and respiratory rate. These are ozone concentration, ambient temperature, and humidity. In a hospital environment, these factors are not necessarily all controllable, making infection prevention and control a challenge.
Topics: Aerosols; COVID-19; Cross Infection; Delivery of Health Care; Denmark; Disinfection; Humans; SARS-CoV-2
PubMed: 34050990
DOI: 10.1111/apm.13160 -
Chemosphere Jul 2021Disinfection is usually the final step in water treatment and its effectiveness is of paramount importance in ensuring public health. Chlorination, ultraviolet (UV)... (Review)
Review
Disinfection is usually the final step in water treatment and its effectiveness is of paramount importance in ensuring public health. Chlorination, ultraviolet (UV) irradiation and ozone (O) are currently the most common methods for water disinfection; however, the generation of toxic by-products and the non-remnant effect of UV and O still constitute major drawbacks. Photo-assisted electrochemical advanced oxidation processes (EAOPs) on the other hand, appear as a potentially effective option for water disinfection. In these processes, the synergism between electrochemically produced active species and photo-generated radicals, improve their performance when compared with the corresponding separate processes and with other physical or chemical approaches. In photo-assisted EAOPs the inactivation of pathogens takes place by means of mechanisms that occur at different distances from the anode, that is: (i) directly at the electrode's surface (direct oxidation), (ii) at the anode's vicinity by means of electrochemically generated hydroxyl radical species (quasi-direct), (iii) or at the bulk solution (away from the electrode surface) by photo-electrogenerated active species (indirect oxidation). This review addresses state of the art reports concerning the inactivation of pathogens in water by means of photo-assisted EAOPs such as photo-electrocatalytic process, photo-assisted electrochemical oxidation, photo-electrocoagulation and cathodic processes. By focusing on the oxidation mechanism, it was found that while quasi-direct oxidation is the preponderant inactivation mechanism, the photo-electrocatalytic process using semiconductor materials is the most studied method as revealed by numerous reports in the literature. Advantages, disadvantages, trends and perspectives for water disinfection in photo-assisted EAOPs are also analyzed in this work.
Topics: Disinfection; Hydrogen Peroxide; Oxidation-Reduction; Ultraviolet Rays; Water; Water Pollutants, Chemical; Water Purification
PubMed: 33979920
DOI: 10.1016/j.chemosphere.2021.129957 -
Molecules (Basel, Switzerland) Apr 2021The direct and indirect bactericidal effects of dielectric barrier discharge (DBD) cold atmospheric-pressure microplasma in an air and plasma jet generated in an...
The direct and indirect bactericidal effects of dielectric barrier discharge (DBD) cold atmospheric-pressure microplasma in an air and plasma jet generated in an argon-oxygen gas mixture was investigated on and . An AC power supply was used to generate plasma at relatively low discharge voltages (0.9-2.4 kV) and frequency (27-30 kHz). Cultured bacteria were cultivated at a serial dilution of 10, then exposed to direct microplasma treatment and indirect treatment through plasma-activated water (PAW). The obtained results revealed that these methods of bacterial inactivation showed a 2 and 1 log reduction in the number of survived CFU/mL with direct treatment being the most effective means of treatment at just 3 min using air. UV-Vis spectroscopy confirmed that an increase in treatment time at 1.2% O, 98.8% Ar caused a decrease in O concentration in the water as well as a decrease in absorbance of the peaks at 210 nm, which are attributed NO and NO concentration in the water, termed denitratification and denitritification in the treated water, respectively.
Topics: Anti-Bacterial Agents; Atmospheric Pressure; Microbial Sensitivity Tests; Ozone; Plasma Gases; Reactive Nitrogen Species; Reactive Oxygen Species; Staphylococcus aureus; Sterilization; Water
PubMed: 33925959
DOI: 10.3390/molecules26092523