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1.
Carbohydrate Polymer Technologies and Applications ; 5:100320, 2023.
Article in English | ScienceDirect | ID: covidwho-2325044

ABSTRACT

The present study narrates the extraction of rutin from Tagetes erecta (Marigold) via maceration followed by ultrasonication. The extracted rutin was further fabricated into nanoparticles by high-pressure homogenization (HPH) and assessed by HPLC, DSC, XRD, TEM, and FTIR spectroscopy. The optimized batch of nanoparticles obtained using 32 central composite design (CCD) which exhibited particle size 209±14 nm, PDI 0.234±0.06, and 92±1.3% entrapment efficiency. The lyophilized rutin nanoparticles were further converted into nano-suspension. Interestingly, the rutin nano-suspension exhibited a similar antitussive effect in vivo as that by standard treatment pentoxyverine and reduced the coughing times within 2 min. Also, the phlegm showed high UV absorbance, implying its better expectorant activity than the standard and control. The rutin nano-suspension was highly stable and shelf life was found to be ∼29.1 months. The present study, for the first time, paves a way for the use of rutin nano-suspension to overcome chest congestion, shortening of breath, and in the management of cough.

2.
Science and Technology of Food Industry ; 44(2):293-298, 2023.
Article in Chinese | Scopus | ID: covidwho-2274255

ABSTRACT

Objective: Exploring the disinfection effect of high-pressure carbon dioxide (HPCD) on human coronavirus 229E (hCoV-229E). Methods: The human coronavirus 229E (hCoV-229E) was treated by HPCD at different temperatures (10, 25, and 37 ℃) and pressures (6.3 and 10 MPa) for different time (15 and 30 min). Result: Compared with the control groups under the corresponding temperatures, the virus titer in 50 mL tube treated with HPCD at 10 ℃ and 6.3 MPa for 30 min was significantly decreased (P<0.05). The virus titer was also significantly reduced after treatment with HPCD at 37 ℃ and 10 MPa for 15 min (P<0.01). Moreover, the virus titers inoculated on the surfaces of salmon meat, shrimp shell, and polyethylene packing materials were all significantly decreased after HPCD treatment at 37 ℃ and 10 MPa for 15 min as compared with the corresponding control groups (P<0.05). Conclusion: HPCD treatment at 37 ℃ and 10 MPa for 15 minutes could effectively disinfect hCoV-229E on the surface of food (salmon meat and shrimp shell) and polyethylene packaging materials. © 2023, Editorial Department of Science and Technology of Food Science. All rights reserved.

3.
Occupational and Environmental Medicine ; 80(Suppl 1):A78, 2023.
Article in English | ProQuest Central | ID: covidwho-2285877

ABSTRACT

IntroductionMany surgeons in public health systems were deployed away from elective surgery during the COVID-19 pandemic and are now working under high pressure to reduce long waiting-lists including for people with malignancy.MethodsUsing validated methodology, a questionnaire was circulated to surgeons via societies and social media. Anonymized data from voluntary respondents were collected via a centralized database.Results242 Surgeons responded amongst whom 170 (70.3%) were male. 14% were aged 25 to 34, 28% 35 to 44 years, 35% 45 to 54 years, 17% 55 to 64 and 5.8 % were aged 65 and over. 65.7% were urologists, 13.6% orthopaedics and trauma – others came from a range of surgical specialties. 46.3% suffered lower back pain in the prior month, 47.3% stated that this adversely affected work and recreational activities, 57.1% stated this had occurred > 5x in the previous year. Hip, neck and shoulder pain ranged from 6.2–43.8 % with up to 33.9% stating MSK symptoms had interfered with their work and (with the exception of shoulder pain (48.5%)) in each case >50% described symptoms > 5x pa. Only 8.7% reported receiving any ergonomic support to ensure comfort at work and 26.5% had ever received training in ergonomics. Surgeons reported 26% of the time they were often or always at work when required at home, with 48.8% reporting regular impact on private life. Many surgeons (84.4%) also report conflicting demands at work.ConclusionsPost-pandemic, surgeons report a high prevalence of musculoskeletal pain and work/life conflict. Surgeons could themselves take measures to mitigate these effects but planning and development of rotas and operating theatres could also be optimized. Maintaining the health of surgical staff is fundamental to patient safety and to retain highly-trained professionals within their discipline.

4.
Journal of Ethnopharmacology ; 301, 2023.
Article in English | Scopus | ID: covidwho-2246174

ABSTRACT

Ethnopharmacological relevance: Scutellaria baicalensis Georgi. contains varieties of function compounds, and it has been used as traditional drug for centuries. Baicalein is the highest amount of flavonoid found in Scutellaria baicalensis Georgi., which exerts various pharmacological activities and might be a promising drug to treat COVID-19. Aim of the study: The present work aims to investigate the metabolism of baicalein in humans after oral administration, and study the pharmacokinetics of BA and its seven metabolites in plasma and urine. Materials and methods: The metabolism profiling and the identification of baicalein metabolites were performed on HPLC-Q-TOF. Then a column-switching method named MPX™-2 system was applied for the high-throughput quantificationof BA and seven metabolites. Results: Seven metabolites were identified using HPLC-Q-TOF, including sulfate, glucuronide, glucoside, and methyl-conjugated metabolites. Pharmacokinetic study found that BA was extensively metabolized in vivo, and only 5.65% of the drug remained intact in the circulatory system after single dosing. Baicalein-7-O-sulfate and baicalein-6-O-glucuronide-7-O-glucuronide were the most abundant metabolites. About 7.2% of the drug was excreted through urine and mostly was metabolites. Conclusion: Seven conjugated metabolites were identified in our assay. A high-throughput HPLC-MS/MS method using column switch was established for quantifying BA and its metabolites. The method has good sensitivity and reproducibility, and successfully applied for the clinical pharmacokinetic study of baicalein and identified metabolites. We expect that our results will provide a metabolic and pharmacokinetic foundation for the potential application of baicalein in medicine. © 2022

5.
Journal of Pharmaceutical and Biomedical Analysis ; 223, 2023.
Article in English | Scopus | ID: covidwho-2245767

ABSTRACT

A fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation procedure, the herein assay shows a linear calibration curve over the range of 0.2–50 µg/mL and 0.5–25 µg/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 µg/mL for plasma and 0.15 and 0.5 µg/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration. © 2022 Elsevier B.V.

6.
Science and Technology of Food Industry ; 44(2):293-298, 2023.
Article in English | Scopus | ID: covidwho-2243786

ABSTRACT

Objective: Exploring the disinfection effect of high-pressure carbon dioxide (HPCD) on human coronavirus 229E (hCoV-229E). Methods: The human coronavirus 229E (hCoV-229E) was treated by HPCD at different temperatures (10, 25, and 37 ℃) and pressures (6.3 and 10 MPa) for different time (15 and 30 min). Result: Compared with the control groups under the corresponding temperatures, the virus titer in 50 mL tube treated with HPCD at 10 ℃ and 6.3 MPa for 30 min was significantly decreased (P<0.05). The virus titer was also significantly reduced after treatment with HPCD at 37 ℃ and 10 MPa for 15 min (P<0.01). Moreover, the virus titers inoculated on the surfaces of salmon meat, shrimp shell, and polyethylene packing materials were all significantly decreased after HPCD treatment at 37 ℃ and 10 MPa for 15 min as compared with the corresponding control groups (P<0.05). Conclusion: HPCD treatment at 37 ℃ and 10 MPa for 15 minutes could effectively disinfect hCoV-229E on the surface of food (salmon meat and shrimp shell) and polyethylene packaging materials. © 2023, Editorial Department of Science and Technology of Food Science. All rights reserved.

7.
Analytica Chimica Acta ; 1237, 2023.
Article in English | Scopus | ID: covidwho-2242454

ABSTRACT

Hydrogen sulfide is a toxic gas but also established as a naturally occurring gaseous signaling molecule in humans, playing key physiological roles with particular involvement in lung disease including COVID-19. Thiosulfate is the conventional biomarker of hydrogen sulfide and is excreted in human urine at low micromolar levels. Thiosulfate is amenable to detection by the element-selective inductively coupled plasma tandem mass spectrometry (ICPMS/MS), but sulfur speciation in human samples at trace levels is challenging due to the high complexity of human sulfur metabolome and the utility of this detector under such settings has not been demonstrated. We report a method for thiosulfate determination in human urine at trace physiological levels by HPLC-ICPMS/MS. The method involved one-step derivatization to improve chromatographic behavior followed by direct injection. The instrumental limit of detection was 1.4 μg S L−1 (0.02 μM or 0.1 pmol). In a group of samples from volunteers (n = 24), measured thiosulfate concentrations in the diluted urine matrix were down to 8.0 μg S L−1 with a signal-to-noise ratio >10. The method was validated for recovery (80–110%), repeatability (RSD% <5%), and linearity (r2 = 0.9999, at a tested working concentration range of 0.01–1.0 mg S L−1), and the accuracy was assessed by comparing with HPLC-ESIMS/MS which showed agreement within ±20%. This work demonstrates the applicability of HPLC-ICPMS/MS for sulfur speciation at trace levels in a matrix with complex sulfur metabolome as human urine and provides a sensitive method for the determination of the hydrogen sulfide biomarker. © 2022 The Authors

8.
Science and Technology of Food Industry ; 44(2):293-298, 2023.
Article in Chinese | Scopus | ID: covidwho-2233802

ABSTRACT

Objective: Exploring the disinfection effect of high-pressure carbon dioxide (HPCD) on human coronavirus 229E (hCoV-229E). Methods: The human coronavirus 229E (hCoV-229E) was treated by HPCD at different temperatures (10, 25, and 37 ℃) and pressures (6.3 and 10 MPa) for different time (15 and 30 min). Result: Compared with the control groups under the corresponding temperatures, the virus titer in 50 mL tube treated with HPCD at 10 ℃ and 6.3 MPa for 30 min was significantly decreased (P<0.05). The virus titer was also significantly reduced after treatment with HPCD at 37 ℃ and 10 MPa for 15 min (P<0.01). Moreover, the virus titers inoculated on the surfaces of salmon meat, shrimp shell, and polyethylene packing materials were all significantly decreased after HPCD treatment at 37 ℃ and 10 MPa for 15 min as compared with the corresponding control groups (P<0.05). Conclusion: HPCD treatment at 37 ℃ and 10 MPa for 15 minutes could effectively disinfect hCoV-229E on the surface of food (salmon meat and shrimp shell) and polyethylene packaging materials. © 2023, Editorial Department of Science and Technology of Food Science. All rights reserved.

9.
Viruses ; 14(12)2022 12 14.
Article in English | MEDLINE | ID: covidwho-2163623

ABSTRACT

Infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of the COVID-19 pandemic, leads to profound remodeling of cellular membranes, promoting viral replication and virion assembly. A full understanding of this drastic remodeling and the process of virion morphogenesis remains lacking. In this study, we applied room temperature transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) tomography to visualize the SARS-CoV-2 replication factory in Vero cells, and present our results in comparison with published cryo-EM studies. We obtained cryo-EM-like clarity of the ultrastructure by employing high-pressure freezing, freeze substitution (HPF-FS) and embedding, allowing room temperature visualization of double-membrane vesicles (DMVs) in a near-native state. In addition, our data illustrate the consecutive stages of virion morphogenesis and reveal that SARS-CoV-2 ribonucleoprotein assembly and membrane curvature occur simultaneously. Finally, we show the tethering of virions to the plasma membrane in 3D, and that accumulations of virus particles lacking spike protein in large vesicles are most likely not a result of defective virion assembly at their membrane. In conclusion, this study puts forward a room-temperature EM technique providing near-native ultrastructural information about SARS-CoV-2 replication, adding to our understanding of the interaction of this pandemic virus with its host cell.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Chlorocebus aethiops , Humans , Vero Cells , Pandemics , Virion/ultrastructure
10.
Environmental Health Engineering and Management Journal ; 9(3):201-211, 2022.
Article in English | Web of Science | ID: covidwho-2111640

ABSTRACT

Background: In recent years, the world has faced with the COVID-19 pandemic, followed by a significant increase in the use of antibiotics to control the COVID-19 and other secondary infections. The non -biodegradable characteristics of antibiotics and their residues in the environment leads to increased microbial and drug resistance. Therefore, due to the high importance of antibiotics, two antibiotics, ampicillin and penicillin G, were studied in Isfahan municipal wastewater treatment plants (WWTPs).Methods: Sampling was performed for two months during 13 sampling periods and antibiotics were measured using high-performance liquid chromatography with UV detector (HPLC/UV) instrument.Results: Ampicillin and penicillin G were identified in all samples taken from the both WWTPs. The average concentration of penicillin G in WWTP E and S at the influent, effluent and its removal efficiency were 1050.54 +/- 761.43 ug/L, 52.89 +/- 49.27 ug/L, 89.80 +/- 19.42%, 2055.12 +/- 1788.08 ug/L, 143.01 +/- 162.59 ug/L and 82.76 +/- 21.85%, respectively. Also, the average concentration of ampicillin in WWTP E and Sin the influent (796.44 +/- 809.6 and 447.1 +/- 322.39 ug/L), effluent (48.94 +/- 24.25 and 90.31 +/- 75.91 ug/L), and its removal efficiency (86.22 +/- 19.84% and 66.85 +/- 24.88%) were determined.Conclusion: In two studied WWTPs, the concentration of antibiotics was higher during the COVID-19 pandemic in comparison with previous studies. The statistical analysis showed that there was no significant relationship between the concentration of antibiotics in WWTPs (P < 0.05). Also, the statistical results indicated that the correlation is not significant between removal efficiency of antibiotics and removal efficiency of wastewater main parameters.

11.
Food Control ; 145: 109401, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2041758

ABSTRACT

During the pandemic of coronavirus disease 2019, the fact that frozen foods can carry the relevant virus raises concerns about the microbial safety of cold-chain foods. As a non-thermal processing technology, high pressure carbon dioxide (HPCD) is a potential method to reduce microbial load on cold-chain foods. In this study, we explored the microbial inactivation of low temperature (5-10 °C) HPCD (LT-HPCD) and evaluated its effect on the quality of prawn during freeze-chilled and frozen storage. LT-HPCD treatment at 6.5 MPa and 10 °C for 15 min could effectively inactivate E. coli (99.45%) and S. aureus (94.6%) suspended in 0.85% NaCl, SARS-CoV-2 Spike pseudovirus (>99%) and human coronavirus 229E (hCoV-229E) (>1-log virus tilter reduction) suspended in DMEM medium. The inactivation effect of LT-HPCD was weakened but still significant when the microorganisms were inoculated on the surface of food or package. LT-HPCD treatment at 6.5 MPa and 10 °C for 15 min achieved about 60% inactivation of total aerobic count while could maintain frozen state and quality of prawn. Moreover, LT-HPCD treated prawn exhibited significant slower microbial proliferation and no occurrence of melanosis compared with the untreated samples during chilled storage. A comprehensive quality investigation indicated that LT-HPCD treatment could maintain the color, texture and sensory of prawn during chilled or frozen storage. Consequently, LT-HPCD could improve the microbial safety of frozen prawn while maintaining its original quality, and could be a potential method for food industry to improve the microbial safety of cold-chain foods.

12.
IOP Conference Series. Earth and Environmental Science ; 1050(1):012026, 2022.
Article in English | ProQuest Central | ID: covidwho-1931769

ABSTRACT

Air filtration is an essential process in indoor air conditioning and its physical removal of particulate matter is critical for enhancing indoor air quality, especially in arid regions including United Arab Emirates. In such regions, meeting indoor air quality standard is challenging during sporadic sandstorms when common air conditioning systems are unable to maintain indoor air quality properly. Such inability occurs either due to air infiltration through building’s fenestrations exposing indoor air to excessive particulate matter or the failure of inlet air filters after rapid clogging and high pressure drops. Such failure may be observed frequently in buildings with frequent openings such as public buildings and warehouses. Aerosolized pathogenic microorganisms, e.g., SARS-CoV-2 virus, can be modelled through air particle matter and be removed to a certain degree. In addition, the recent global pandemic raised more awareness towards the necessity of particulate matter filtration in indoor environment. Employing independent air filtration units might be a great solution for intermittent or emergency situations, when primary or additional air filtration process is required to attain proper indoor air quality. The main objective of this paper is to attempt designing, manufacturing, and utilizing an easy to set portable filtration unit and to assist buildings’ existing air conditioning systems in airborne dust particle elimination. The unit is designed and manufactured with additional feature accommodating easy installation of commercially available filters for further performance studies. The unit was equipped with all necessary performance monitoring sensors to detect key parameters such as air velocity, pressure differential, temperature, humidity, and particulate matter before and after filtration. The results revealed interesting information associated with the performance of commercially available filters and the feasibility of such independent filtration units.

13.
3rd International Conference on Education Development and Studies, ICEDS 2022 ; : 83-89, 2022.
Article in English | Scopus | ID: covidwho-1902118

ABSTRACT

Blended learning is an adaptive (and necessary) response adopted by most universities to face the challenges posed by the COVID-19 ongoing pandemic. Academic Learning Management Systems (ALMSs) played a strategic and pivotal role under high pressure. Online learning can occur by implementing integrated solutions embedded in the Academic portals or subscriptions to other videoconferencing solutions. Blending online and face-to-face teaching proved challenging from different perspectives. This approach has been considered essential to ensure an adequate level of service and avoid outflows of students, but it led to increased teaching workload, improved infrastructure, flexible pedagogic approach, enhanced technologies, specific training, and IT solutions development. The authors perform a SWOT analysis of blended learning, in a transnational Higher Education Context, to match the findings with the most relevant and critical challenges. The results, therefore, support the Information System analysis, focusing on one of the most widespread ALMSs. The case of Blackboard is finally considered, and some implementations are suggested. © 2022 Association for Computing Machinery. All rights reserved.

14.
IAENG International Journal of Computer Science ; 49(2), 2022.
Article in English | Scopus | ID: covidwho-1877466

ABSTRACT

The world has experienced the spread of a dangerous virus, Coronavirus (COVID-19), that has caused the death of millions of people worldwide at an extremely rapid rate, many studies have confirmed that the virus can be detected effectively using medical images. However, it takes a long time to analyze each image by radiologists who suffer from high pressures, especially due to the high similarity of symptoms between this virus and other respiratory diseases, which can lead to the confusion of cases and, consequently, the inability to identify them quickly, which could be a problem in a pandemic situation. In this paper, a methodology is proposed for the rapid and automatic diagnosis of this virus from chest radiographic images through the use of Artificial Intelligence (AI) techniques. There are two stages of the proposed model. The first step is data augmentation and preprocessing;the second step is the detection of COVID-19 with a transfer learning technique using a pre-trained deep convolutional network (CNN) architecture to extract features, Then, the obtained feature vectors are classified into three classes: COVID-19, Normal, and pneumonia, from two open medical repositories. In the experimentation phase of our model, we evaluate a set of common metrics to measure the performance of the architecture. Experimental conclusions show an accuracy of 96.52% for all classes, then a comparison with existing models in literature demonstrates that our proposed model achieves better classification accuracy © 2022. IAENG International Journal of Computer Science.All Rights Reserved.

15.
Applied Sciences ; 12(10):5287, 2022.
Article in English | ProQuest Central | ID: covidwho-1871975

ABSTRACT

As a requirement for sustainable development, air-cycle refrigeration has received wide attention as a candidate for environmentally friendly air conditioning technology. In this study, the thermodynamic performance of air refrigeration cycles is investigated in compartment air conditioning. The effects of compressor efficiency, expander efficiency, ambient humidity, all-fresh-air supply and ambient pressure on the cycle performance are presented. The effects of compressor arrangement in the high-pressure cycle and the low-pressure cycle are compared. An open-loop high-pressure cycle has a larger COP than that of an open-loop low-pressure cycle but requires larger heat exchange. The performance of air refrigeration cycles with full fresh air is studied, and the influence of fresh air is discussed. Schemes for condensed water recirculation with wet compression are proposed, which can improve the COPs of open-loop low-pressure cycles by 44.7%, 48.8% and 48.4%. In the air conditioning of plateau trains, open-loop high-pressure cycles have slightly lower COPs, but they can supply air with elevated pressure and oxygen concentration.

16.
Int J Mol Sci ; 23(10)2022 May 19.
Article in English | MEDLINE | ID: covidwho-1862813

ABSTRACT

Previous studies suggest that berberine, an isoquinoline alkaloid, has antiviral potential and is a possible therapeutic candidate against SARS-CoV-2. The molecular underpinnings of its action are still unknown. Potential targets include quadruplexes (G4Q) in the viral genome as they play a key role in modulating the biological activity of viruses. While several DNA-G4Q structures and their binding properties have been elucidated, RNA-G4Qs such as RG-1 of the N-gene of SARS-CoV-2 are less explored. Using biophysical techniques, the berberine binding thermodynamics and the associated conformational and hydration changes of RG-1 could be characterized and compared with human telomeric DNA-G4Q 22AG. Berberine can interact with both quadruplexes. Substantial changes were observed in the interaction of berberine with 22AG and RG-1, which adopt different topologies that can also change upon ligand binding. The strength of interaction and the thermodynamic signatures were found to dependent not only on the initial conformation of the quadruplex, but also on the type of salt present in solution. Since berberine has shown promise as a G-quadruplex stabilizer that can modulate viral gene expression, this study may also contribute to the development of optimized ligands that can discriminate between binding to DNA and RNA G-quadruplexes.


Subject(s)
Berberine , COVID-19 Drug Treatment , Berberine/pharmacology , DNA/chemistry , Humans , RNA/metabolism , SARS-CoV-2
17.
Economic and Social Development: Book of Proceedings ; : 139-143, 2022.
Article in English | ProQuest Central | ID: covidwho-1801716

ABSTRACT

In this publication we set an objectively complicated task to analyse the opportunities of strategic decision-making during crisis by attempting to make a partial analysis of the ongoing crisis caused by the COVID 19 pandemic and the emerged military conflict between the Russian Federation and Ukraine. Crisis circumstances require societies to quickly rethink and develop adequate strategies and respectively to formulate strategic goals and plan processes. In many cases preliminary analysis and assessment are practically impossible /especially when it comes to natural disasters or crises/ and this requires a different operational order of problem solving, which includes formulating new unconventional goals and then implementing planning not objectified by a particular and accurate analysis. All this puts whole systems and societies to the test, and those who are empowered to manage the process - under high pressure from unforeseen circumstances and not always objective judgments. Which, in turn, creates a number of subsequent critical issues in the management process.

18.
2021 SPE International Conference on Oilfield Chemistry, OCC 2021 ; 2021-December, 2021.
Article in English | Scopus | ID: covidwho-1770833

ABSTRACT

Preservative biocides are designed to control microbial growth and biogenic souring in the downhole environment. We report the prevention of biogenic souring by 4,4-dimethyloxazolidine (DMO, a preservative biocide) and glutaraldehyde as compared to that afforded by tributyl tetradecyl phosphonium chloride (TTPC, a cationic surface-active biocide), in a first-of-its kind suite of High Pressure, High Temperature (HPHT) Bioreactors that simulate hydraulically fractured shale reservoirs. The design of these new bioreactors, which recreate the downhole environment (temperatures, pressures, formation solids, and frac additives) in a controlled laboratory environment, enables the evaluation of biocides under field-relevant conditions. The bioreactors receiving either no biocide treatment or treatment with a high concentration of TTPC (50 ppm active ingredient) rapidly soured within the first two weeks of shut-in, and all surpassed the maximum detectable level of H2S (343 ppm) after the addition of live microbes to the reactors. Conversely, a higher loading of DMO (150 pppm active ingredient) maintained H2S concentrations below the minimum dectable level (5 ppm) for six weeks, and held H2S concentrations to 10.3 +/- 5.2 ppm after fifteen weeks of shut-in and two post shut-in microbial rechallenges. In a second study, a lower concentration of DMO (50 ppm active ingredient) maintained H2S concentrations below the minimum detectable level through the addition of live microbes after three weeks, and H2S concentrations only registered above 10 ppm upon a second addition of live microbes after five weeks. In this same study (which was performed at moderate temperatures), a 50 ppm (active ingredient) treatment of glutaraldehyde also maintained H2S concentrations below the minimum detectable level through the addition of live microbes after three weeks, and H2S concentrations registered 15.0 +/- 9.7 ppm H2S after four weeks. Similar time scales of protection are observed for each treatment condition through the enumeration of microbes present in each reactor. The differentiation in antimicrobial activity (and specifically, prevention of biogenic souring) afforded by DMO and glutaraldehyde suggests that such nonionic, preservative biocides are a superior choice for maintaining control over problematic microorganisms as compared to surface-active biocides like TTPC at the concentrations tested. The significant duration of efficacy provided by DMO and glutaraldehyde in this first-of-its-kind suite of simulated reservoirs demonstrates that comprehensive preservation and prevention of biogenic souring from completion through to production is feasible. Such comprehensive, prolonged protection is especially relevant for extended shut-ins or drilled but uncompleted wells (DUCS) such as those experienced during the COVID-19 pandemic. The environment simulated within the bioreactors demonstrates that the compatibility afforded by a preservative biocide offers downhole protection that cationic, surface-active biocides do not. Copyright 2021, Society of Petroleum Engineers

19.
10th International Conference on Radar, Antenna, Microwave, Electronics, and Telecommunications, ICRAMET 2021 ; : 201-204, 2021.
Article in English | Scopus | ID: covidwho-1702205

ABSTRACT

The treatment of patients with acute respiratory failure due to COVID-19 needs ventilator machine support to provide oxygenation and ventilation processes. The most critical control in the machine is how to provide precision-inspired oxygen fraction (FiO2) to the patients during the treatment. Generally, the low-flow nasal cannula can provide 4-6 liters per minute of supplemental oxygen with approximately 37 - 45% FiO2. In this paper, we present high-flow and high-pressure oxygen mixing to provide up to 100% FiO2 and 60 liters per minute. The proposed system also employs the close-loop feedback control to achieve a desirable FiO2 set point. It can be used for a Continuous Positive Airway Pressure (CPAP) and Bilevel Positive Airway Pressure (BiPAP) ventilator systems with oxygen as well as a High Flow Nasal Cannula (HFNC) system for acute respiratory patient's syndrome. © 2021 IEEE.

20.
Renew Sustain Energy Rev ; 153: 111786, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1472162

ABSTRACT

Combating the COVID-19 pandemic has raised the demand for and disposal of personal protective equipment in the United States. This work proposes a novel waste personal protective equipment processing system that enables energy recovery through producing renewable fuels and other basic chemicals. Exergy analysis and environmental assessment through a detailed life cycle assessment approach are performed to evaluate the energy and environmental sustainability of the processing system. Given the environmental advantages in reducing 35.42% of total greenhouse gas emissions from the conventional incineration and 43.50% of total fossil fuel use from landfilling processes, the optimal number, sizes, and locations of establishing facilities within the proposed personal protective equipment processing system in New York State are then determined by an optimization-based site selection methodology, proposing to build two pre-processing facilities in New York County and Suffolk County and one integrated fast pyrolysis plant in Rockland County. Their optimal annual treatment capacities are 1,708 t/y, 8,000 t/y, and 9,028 t/y. The proposed optimal personal protective equipment processing system reduces 31.5% of total fossil fuel use and 35.04% of total greenhouse gas emissions compared to the personal protective equipment incineration process. It also avoids 41.52% and 47.64% of total natural land occupation from the personal protective equipment landfilling and incineration processes.

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