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1.
Thermochimica Acta ; 711:N.PAG-N.PAG, 2022.
Artigo em Inglês | Academic Search Complete | ID: covidwho-1839340

RESUMO

• Catalytic pyrolysis of COVID-19 mask/ZSM-5 zeolite was studied using TG-FTIR. • The generated compounds from catalytic pyrolysis process was studied using GC–MS. • Pyrolysis kinetics were calculated using the different methods. • TGA and DTG curves were simulated using DAEM and IPR with deviations <1. This research aims to develop a new thermochemical strategy to extract butane from the billions of wasted COVID-19 masks that are generated every month. The experiments were conducted with 3-ply face masks (3PFM) over ZSM-5 zeolite with different ratios of ZSM-5 to 3PFM (w/w: 6, 12, 25, and 50 wt.%) using thermogravimetry (TGA) at different heating conditions. Also, the effect of ZSM-5 concentration and heating rates was examined using TG-FTIR and GC–MS measurements. Besides, the kinetics behavior of the developed strategy was modelled using linear and nonlinear isoconversional modeling techniques, thus calculating the activation energy (Ea) for each conversion region. Finally, all required parameters to fit TGA and differential scanning calorimetry (DTG) experimental curves were estimated using the distributed activation energy (DAEM) and the independent parallel reactions (IPR) techniques, respectively. The results showed that the decomposed samples are very rich in aromatic and aliphatic (-C-H) compounds. Meanwhile, and based on GC–MS results, butanol compound was the basic component in the generated compounds with abundance of 31% at 25 wt.% of ZSM-5 at lowest heating rate (5 °C/min), whereas the average Ea at 25% of ZSM-5 (sample enriched with butanol) was estimated in the ranges 158–187 kJ mol−1 (linear methods with R2 > 0.96) and 167–169 kJ/mol (nonlinear methods with R2 > 0.98). Finally, DAEM and IPR succeeded to simulate TGA and DTG curves of ZSM-5/3PFM samples with very small deviation. Based on that, the catalytic pyrolysis strategy over ZSM-5 zeolite can be used effectively to dispose of COVID-19 masks and to convert them into butanol compound that can be used as a liquid fuel and lubricant. [ FROM AUTHOR] Copyright of Thermochimica Acta is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

2.
Biophysica ; 2(1):79, 2022.
Artigo em Inglês | ProQuest Central | ID: covidwho-1818049

RESUMO

In this work, we studied the effect of as on the interaction of membrane DPPC with the key antifibrotic drug pirfenidone. Liposomal forms of pirfenidone were obtained using passive loading. The addition of cholesterol reduces the loading efficiency of pirfenidone by 10%. The main binding site of pirfenidone in DPPC liposomes is the carbonyl group: the interaction with PF significantly increases the proportion of low-hydrated carbonyl groups as revealed by ATR-FTIR spectroscopy. The phosphate group acts as an additional binding site;however, due to shielding by the choline group, this interaction is weak. The hydrophobic part of the bilayer is not involved in PF binding at room temperature. Cholesterol changes the way of interaction between carbonyl groups and pirfenidone probably because of the formation of two subpopulations of DPPC and causes a dramatic redistribution of carbonyl groups onto the degrees of hydration. The proportion of moderately hydrated carbonyl groups increases, apparently due to the deepening of pirfenidone into the circumpolar region of the bilayer. For the first time, a change in the microenvironment of pirfenidone upon binding to liposomes was shown: aromatic moiety interacts with the bilayer.

3.
Measurement ; : 111258, 2022.
Artigo em Inglês | ScienceDirect | ID: covidwho-1804798

RESUMO

In this research, blood samples of 47 patients infected by COVID were analyzed. The samples were taken on the 1st, 3rd and 6th month after the detection of COVID infection. Total antibody levels were measured against the SARS-CoV-2 N antigen and surrogate virus neutralization by serological methods. To differentiate COVID patients with different antibody levels, Fourier Transform InfraRed (FTIR) and Raman spectroscopy methods were used. The spectroscopy data were analyzed by multivariate analysis, machine learning and neural network methods. It was shown, that analysis of serum using the above-mentioned spectroscopy methods allows to differentiate antibody levels between 1 and 6 months via spectral biomarkers of amides II and I. Moreover, multivariate analysis showed, that using Raman spectroscopy in the range between 1317 cm-1 and 1432 cm-1, 2840 cm-1 and 2956 cm-1 it is possible to distinguish patients after 1, 3, and 6 months from COVID with a sensitivity close to 100%.

4.
Biochimica et Biophysica Acta (BBA) - Biomembranes ; : 183945, 2022.
Artigo em Inglês | ScienceDirect | ID: covidwho-1800195

RESUMO

Remdesivir is a novel antiviral drug, which is active against the SARS-CoV-2 virus. Remdesivir is known to accumulate in the brain but it is not clear whether it influences the neurotransmission. Here we report diverse and pronounced effects of remdesivir on transportation and release of excitatory and inhibitory neurotransmitters in rat cortex nerve terminals (synaptosomes) in vitro. Direct incorporation of remdesivir molecules into the cellular membranes was shown by FTIR spectroscopy, planar phospholipid bilayer membranes and computational techniques. Remdesivir decreases depolarization-induced exocytotic release of L-[14C] glutamate and [3H] GABA, and also [3H] GABA uptake and extracellular level in synaptosomes in a dose-dependent manner. Fluorimetric studies confirmed remdesivir-induced impairment of exocytosis in nerve terminals and revealed a decrease in synaptic vesicle acidification. Our data suggest that remdesivir dosing during antiviral therapy should be precisely controlled to prevent possible neuromodulatory action at the presynaptic level. Further studies of neurotropic and membranotropic effects of remdesivir are necessary.

5.
Reactive and Functional Polymers ; 175:105268, 2022.
Artigo em Inglês | ScienceDirect | ID: covidwho-1796182

RESUMO

The global spread of COVID-19 continues, industrial raw material production is being tested, and the fracturing cost of oil and gas fields continues to rise, posing new challenges to polymer fracturing fluids. A new hydrophobic association polymer PDMA1 with a double tailed monomer structure was synthesized inside this study. Fourier infrared spectroscopy, Electron microscope scanning, Fluorescence spectroscopy, and polymer viscoelasticity were used to investigate the polymer's basic properties. Finally, using molecular dynamics simulation tools, the network structure of PDMA1 was discovered to be more temperature resistant than that of HPAM. PDMA1 has larger hydrodynamic dimensions than HPAM at the same temperature, its radius of gyration is more than HPAM, and its viscosity is greater than HPAM under the same conditions. This provides an additional avenue of investigation for temperature-resistant hydrophobically associating polymers.

6.
10th IEEE International Conference on Intelligent Computing and Information Systems, ICICIS 2021 ; : 124-129, 2021.
Artigo em Inglês | Scopus | ID: covidwho-1779105

RESUMO

Exhaled breath analysis is a promising noninvasive method for rapid diagnosis of diseases by detecting different types of volatile organic compounds (VOCs) that are used as biomarkers for early detection of various diseases such as lung cancer, diabetes, anemias, etc... and more recently COVID-19. Infrared spectroscopy seems to be a promising method for VOCs detection due to its ease of use, selectivity, and existence of compact low-cost devices. In this work, the use of Fourier transforms infrared (FTIR) spectrometer to analyze breath samples contained in a gas cell is investigated using deep learning and taking into account the practical performance limits of the spectrometer. Synthetic spectra are generated using infrared gas spectra databases to emulate real spectra resulted from a breath sample and train the neural network model (NNM). The dataset is generated in the spectral range of 2000 cm-1 to 6500 cm-1 and assuming a light-gas interaction length of 5 meters. The FTIR device performance is assumed with a signal-to-noise ratio (SNR) of 20,000:1 and a spectral resolution of 40 cm-1. The proposed NNM contains a locally connected and 4 fully connected layers. The concentrations of 9 biomarker gases in the exhaled breath are predicted with r2 score higher than 0.93, including carbon dioxide, water vapor, acetone, ethene, ammonia, methane, carbonyl sulfide, carbon monoxide and acetaldehyde demonstrating the possibility of detection. © 2021 IEEE.

7.
Chemosensors ; 10(3):108, 2022.
Artigo em Inglês | ProQuest Central | ID: covidwho-1760412

RESUMO

The smuggling of illicit drugs urges the development of new tools for rapid on-site identification in cargos. Current methods rely on presumptive color tests and portable spectroscopic techniques. However, these methods sometimes exhibit inaccurate results due to commonly used cutting agents, the colorful nature of the sample or because the drugs are smuggled in common goods. Interestingly, electrochemical sensors can deal with these specific problems. Herein, an electrochemical device is presented that uses affordable screen-printed electrodes for the electrochemical profiling of several illicit drugs by square-wave voltammetry (SWV). The identification of the illicit compound is based on the oxidation potential of the analyte. Hence, a library of electrochemical profiles is built upon the analysis of illicit drugs and common cutting agents. This library allows the design of a tailor-made script that enables the identification of each drug through a user-friendly interface (laptop or mobile phone). Importantly, the electrochemical test is compared by analyzing 48 confiscated samples with other portable devices based on Raman and FTIR spectroscopy as well as a laboratory standard method (i.e., gas chromatography–mass spectrometry). Overall, the electrochemical results, obtained through the analysis of different samples from confiscated cargos at an end-user site, present a promising alternative to current methods, offering low-cost and rapid testing in the field.

8.
Thermochimica Acta ; : 179198, 2022.
Artigo em Inglês | ScienceDirect | ID: covidwho-1757863

RESUMO

This research aims to develop a new thermochemical strategy to extract butane from the billions of wasted Covid-19 masks that are generated every month. The experiments were conducted with 3-ply face masks (3PFM) over ZSM-5 zeolite with different ratios of ZSM-5 to 3PFM (w/w: 6, 12, 25, and 50 wt.%) using thermogravimetry (TGA) at different heating conditions. Also, the effect of ZSM-5 concentration and heating rates was examined using TG-FTIR and GC-MS measurements. Besides, the kinetics behaviour of the developed strategy was modelled using linear and nonlinear isoconversional modelling techniques, thus calculating the activation energy (Ea) for each conversion region. Finally, all required parameters to fit TGA and differential scanning calorimetry (DTG) experimental curves were estimated using the distributed activation energy (DAEM) and the independent parallel reactions (IPR) techniques, respectively. The results showed that the decomposed samples are very rich in aromatic and aliphatic (-C-H) compounds. Meanwhile, and based on GC-MS results, butanol compound was the basic component in the generated compounds with abundance of 31% at 25 wt.% of ZSM-5 at lowest heating rate (5 ˚C/min), whereas the average Ea at 25% of ZSM-5 (sample enriched with butanol) was estimated in the ranges 158-187 kJ mol−1 (linear methods with R2 > 0.96) and 167-169 kJ/mol (nonlinear methods with R2 > 0.98). Finally, DAEM and IPR succeeded to simulate TGA and DTG curves of ZSM-5/3PFM samples with very small deviation. Based on that, the catalytic pyrolysis strategy over ZSM-5 zeolite can be used effectively to dispose of Covid-19 masks and to convert them into butanol compound that can be used as a liquid fuel and lubricant.

9.
Journal of Molecular Structure ; 1258, 2022.
Artigo em Inglês | Scopus | ID: covidwho-1730002

RESUMO

Cepharanthine, a natural alkaloid obtained from the Stephania cepharantha Hayata plant, that has antitumor, anti-inflammatory, antioxidative, antiparasitic, and antiviral properties, has been widely used for many years to treat a wide variety of diseases in Japan. However, to elucidate its mechanism of action needs further study. This study aimed to enlighten the molecular structure, and the anticancer and antiviral action mechanisms of Cepharanthine. To evaluate the molecular structure of Cepharanthine, conformational analysis was performed using the DFT/B3LYP with 6-31G(d,p) basis set. The obtained most stable molecular geometry was then optimized at the DFT/B3LYP/6-311++G(d,p) level of theory. The observed IR and Raman bands were compared with harmonic vibrational frequencies of the optimized structure of cepharanthine, calculated using the same level of theory, and assigned on the base of potential energy distribution (PED). The experimental UV-Vis absorption spectrum was recorded and compared with the simulated Time Dependent (TD-DFT/B3LYP/6-311++G(d,p)) method. Moreover, 1H and 13C NMR spectra has been calculated and compared by the experimental spectra. To reveal pharmacological importance of Cepharanthine, a molecular docking study was performed with NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) receptor which controls transcription of DNA, cytokine production and cell survival. Molecular docking simulations revealed that Cepharanthine showed strong binding affinity to NF-κB receptor (ΔG = - 8.9 kcal/mol). In addition, to enlight the antiviral properties of cepharantine and to explore the possibility of its use in the treatment of COVID-19, the interactions of cepharanthine with ACE2, apo and holo forms of COVID-19 main protease enzyme (Mpro) and spike glycoprotein of SARSCoV-2 receptors were investigated. © 2022 Elsevier B.V.

10.
EClinicalMedicine ; 45: 101308, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: covidwho-1693678

RESUMO

Background: The current SARS-CoV-2 pandemic created an urgent need for rapid, infection screening applied to large numbers of asymptomatic individuals. To date, nasal/throat swab polymerase chain reaction (PCR) is considered the "gold standard". However, this is inconducive to mass, point-of-care (POC) testing due to person discomfort during sampling and a prolonged result turnaround. Breath testing for disease specific organic compounds potentially offers a practical, rapid, non-invasive, POC solution. The study compares the Breath of Health, Ltd. (BOH) breath analysis system to PCR's ability to screen asymptomatic individuals for SARS-CoV-2 infection. The BOH system is mobile and combines Fourier-transform infrared (FTIR) spectroscopy with artificial intelligence (AI) to generate results within 2 min and 15 s. In contrast to prior SARS-CoV-2 breath analysis research, this study focuses on diagnosing SARS-CoV-2 via disease specific spectrometric profiles rather than through identifying the disease specific molecules. Methods: Asymptomatic emergency room patients with suspected SARS-CoV-2 exposure in two leading Israeli hospitals were selected between February through April 2021. All were tested via nasal/throat-swab PCR and BOH breath analysis. In total, 297 patients were sampled (mean age 57·08 ± SD 18·86, 156 males, 139 females, 2 unknowns). Of these, 96 were PCR-positive (44 males, 50 females, 2 unknowns), 201 were PCR-negative (112 males, 89 females). One hundred samples were used for AI identification of SARS-CoV-2 distinguishing spectroscopic wave-number patterns and diagnostic algorithm creation. Algorithm validation was tested in 100 proof-of-concept samples (34 PCR-positive, 66 PCR-negative) by comparing PCR with AI algorithm-based breath-test results determined by a blinded medical expert. One hundred additional samples (12 true PCR-positive, 85 true PCR-negative, 3 confounder false PCR-positive [not included in the 297 total samples]) were evaluated by two blinded medical experts for further algorithm validation and inter-expert correlation. Findings: The BOH system identified three distinguishing wave numbers for SARS-CoV-2 infection. In the first phase, the single expert identified the first 100 samples correctly, yielding a 1:1 FTIR/AI:PCR correlation. The two-expert second-phase also yielded 1:1 FTIR/AI:PCR correlation for 97 non-confounders and null correlation for the 3 confounders. Inter-expert correlation was 1:1 for all results. In total, the FTIR/AI algorithm demonstrated 100% sensitivity and specificity for SARS-CoV-2 detection when compared with PCR. Interpretation: The SARS-CoV-2 method of breath analysis via FTIR with AI-based algorithm demonstrated high PCR correlation in screening for asymptomatic individuals. This is the first practical, rapid, POC breath analysis solution with such high PCR correlation in asymptomatic individuals. Further validation is required with a larger sample size. Funding: Breath of Health Ltd, Rehovot, Israel provided study funding.

11.
Journal of Marine Science and Engineering ; 10(2), 2022.
Artigo em Inglês | Scopus | ID: covidwho-1686855

RESUMO

The global outbreak of Corona Virus Disease 2019 (COVID-19) has led to an extreme increase in the use of disposable masks. If the used disposable masks are not appropriately disposed of, they will enter the natural environment and lead to environmental pollution. In order to understand the impacts of disposable masks after being disposed of into the natural environment, aging experiments with simulated natural conditions were performed on the outer, inner, and middle layers of the masks to verify the aging characteristics of disposable masks. We analyzed the mechanical behavior, surface morphology, and Fourier Transform Infrared Spectroscopy (FT-IR) spectra of disposable masks treated with different levels of UV irradiation to understand the possible changes in the masks under UV. Results showed that the elongation at break, tensile strength, and maximum force of all three polypropylene (PP) mask layers decreased after UV irradiation, indicating chemical bond breakage. In the process of photoaging, each layer of the disposable masks showed a different degree of microscopic surface changes after UV irradiation, and these changes gradually intensified with the extension of UV exposure time. FT-IR results showed that functional groups, such as hydroxyl and carbonyl groups increased in each layer after UV irradiation. The results of this study support that, although the different layers of the disposable masks are all made of PP, they age differently in the environment. With the ever-increasing number of disposable masks in the environment, we need to further study the aging and degradation of disposable masks to better understand their potential impacts on the environment in the future. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

12.
Polymers (Basel) ; 14(3)2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: covidwho-1686921

RESUMO

This study is focused on the characterization and investigation of polyvinylidene fluoride (PVDF) nanofibers from the point of view of macro- and nanometer level. The fibers were produced using electrostatic spinning process in air. Two types of fibers were produced since the collector speed (300 rpm and 2000 rpm) differed as the only one processing parameter. Differences in fiber's properties were studied by scanning electron microscopy (SEM) with cross-sections observation utilizing focused ion beam (FIB). The phase composition was determined by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy. The crystallinity was determined by differential scanning calorimetry (DSC), and chemical analysis of fiber's surfaces and bonding states were studied using X-ray photoelectron spectroscopy (XPS). Other methods, such as atomic force microscopy (AFM) and piezoelectric force microscopy (PFM), were employed to describe morphology and piezoelectric response of single fiber, respectively. Moreover, the wetting behavior (hydrophobicity or hydrophilicity) was also studied. It was found that collector speed significantly affects fibers alignment and wettability (directionally ordered fibers produced at 2000 rpm almost super-hydrophobic in comparison with disordered fibers spun at 300 rpm with hydrophilic behavior) as properties at macrolevel. However, it was confirmed that these differences at the macrolevel are closely connected and originate from nanolevel attributes. The study of single individual fibers revealed some protrusions on the fiber's surface, and fibers spun at 300 rpm had a core-shell design, while fibers spun at 2000 rpm were hollow.

13.
International Conference on Advances in Construction Materials and Management, ACMM 2021 ; 191:547-563, 2022.
Artigo em Inglês | Scopus | ID: covidwho-1680644

RESUMO

Event of microplastics (plastic garbage < 5 mm) along the coast is a developing concern around the world, because of the expanded contribution of disposed of squanders from different sources. Around 400 million tons of plastic are produced per year worldwide, out of which only 18% is recycled that has led to its poor disposal practices. The significance of my work is to analyze mainly the positive impacts due to lockdown during COVID-19. The discharged plastics remain in the environment for several 100 years either in their original or fragmented form. The fragmentation of particles is caused by several factors like wind currents, wave currents, abrasions, exposure to sunlight, etc. The study of the distribution of microplastics in time and space, as well as their distribution on parameters, such as polymer type, size, shape, in different coastal environmental all over the world, is the need of the hour. This study describes a framework to assess the presence and distribution of microplastics in marine water and sediments of Adyar and Cooum Estuary along the Chennai coast. Ten sampling sites from each estuary were selected from which surface water and sediments were collected. The samples were carried over to the laboratory for analyzing the presence of microplastic content, and also basic seawater quality parameters were analyzed in the Environmental Engineering Department laboratory. The study investigated the presence and distribution of microplastics before and during COVID-19. The presence and distribution study of microplastics in coastal waters and sediments were carried out by means of FTIR and XRD spectroscopy methods. From this analysis, microplastics occur in both estuaries and there is a significant reduction in Microplastic content in both estuaries because of continuous lockdown due to COVID-19. From FTIR analysis, it was found that the concentration of Polyethylene(PE) and Polypropylene (PP) was higher than the other types of polymer in both the locations and both the times (August 2019 and 2020). And from XRD analysis, black residues were found on most of the microplastics surfaces. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

14.
International Journal of High Dilution Research ; 20(4):29-42, 2021.
Artigo em Inglês | Scopus | ID: covidwho-1675718

RESUMO

Background: High dilutions (HDs) of drugs used in Homeopathy are identical in the composition containing ethanol and water. Yet they show specific therapeutic action on patients. Aims: HDs prepared by serial dilution and succussion are called potencies. Do the potency ranks show any difference from each other? Do serial dilution and succussion contribute to the difference in potency ranks? This study aims to address these two questions. Methodology: The throat swab of a Covid-19 patient was preserved and diluted with aqueous EtOH 90% to prepare the mother tincture(MT)and five different potencies of Covid named Covidinum 6, 12, 30, 200, and 1000cH.Electronic and vibrational (FT-IR) spectroscopy analyzed these potencies and their solvent media. Results and Discussion: Charge transfer (CT) and proton transfer interactions occur during the preparation of the potencies. After normalization, the FT-IR spectra of all the test samples show differences from each other concerning O-H stretching and bending (v2) bands. Serial dilution and succussion contribute to the observed difference in ranks and CT interactions. Covidinum is a new Homeopathic nosode, and its symptoms and therapeutic effect have not yet been ascertained. It is a preliminary study. © International Journal of High Dilution Research. Not for commercial purposes.

15.
Biomedicines ; 10(2)2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: covidwho-1667047

RESUMO

Fourier transform infrared (FTIR) spectroscopy provides a (bio)chemical snapshot of the sample, and was recently used in proof-of-concept cohort studies for COVID-19 saliva screening. However, the biological basis of the proposed technology has not been established. To investigate underlying pathophysiology, we conducted controlled infection experiments on Vero E6 cells in vitro and K18-hACE2 mice in vivo. Potentially infectious culture supernatant or mouse oral lavage samples were treated with ethanol or 75% (v/v) Trizol for attenuated total reflectance (ATR)-FTIR spectroscopy and proteomics, or RT-PCR, respectively. Controlled infection with UV-inactivated SARS-CoV-2 elicited strong biochemical changes in culture supernatant/oral lavage despite a lack of viral replication, determined by RT-PCR or a cell culture infectious dose 50% assay. Nevertheless, SARS-CoV-2 infection induced additional FTIR signals over UV-inactivated SARS-CoV-2 infection in both cell and mouse models, which correspond to aggregated proteins and RNA. Proteomics of mouse oral lavage revealed increased secretion of kallikreins and immune modulatory proteins. Next, we collected saliva from a cohort of human participants (n = 104) and developed a predictive model for COVID-19 using partial least squares discriminant analysis. While high sensitivity of 93.48% was achieved through leave-one-out cross-validation, COVID-19 patients testing negative on follow-up on the day of saliva sampling using RT-PCR was poorly predicted in this model. Importantly, COVID-19 vaccination did not lead to the misclassification of COVID-19 negatives. Finally, meta-analysis revealed that SARS-CoV-2 induced increases in the amide II band in all arms of this study and in recently published cohort studies, indicative of altered ß-sheet structures in secreted proteins. In conclusion, this study reveals a consistent secretory pathophysiological response to SARS-CoV-2, as well as a simple, robust method for COVID-19 saliva screening using ATR-FTIR.

16.
Mar Pollut Bull ; 175: 113389, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: covidwho-1665263

RESUMO

On 10 August 2021, a face mask (14 cm × 9 cm) was found in the feces of a juvenile green turtle, by-caught alive in a set net off the northeast coast of Japan. Although sea turtles have been monitored in this region over the last 15 years (n = 76), face masks had never been found before the Covid-19 pandemic and this is the first detection. Fourier-transform infrared spectroscopy identified the mask as polypropylene. Estrogenic active benzotriazole-type UV stabilizers such as UV329 were detected in commercially available polypropylene face masks. Exposure of marine organisms ingesting plastics to endocrine-disrupting chemicals and physical injury are of concern. This study indicates that changes in human life in the pandemic are beginning to affect marine life. Precautionary actions including establishment of appropriate waste management of personal protective equipment and use of safe additives are urgently needed.


Assuntos
COVID-19 , Tartarugas , Animais , Ecossistema , Humanos , Pandemias , Plásticos , SARS-CoV-2
17.
Journal of Molecular Structure ; : 132443, 2022.
Artigo em Inglês | ScienceDirect | ID: covidwho-1627045

RESUMO

The present article encloses synthesis and characterizations of 3-(2-hydroxy-3-methoxy-phenyl)-1-(3-nitro-phenyl)-propenoneby several experimental techniques such as FT-IR, FT-Raman, NMR and UV-Vis spectral method. The similar techniques are also investigated by computational method using Gaussian softwarewith DFT/ B3LYP/6-311++G (d,p) basis set.Primarily the geometrical parameters obtained by DFT are compared with the related experimental parameters. The experimental FT-IR and FT-Raman spectra of the title molecule are acquired in the span of 4000-400 cm−1 and 4000-50 cm−1 respectively. The complete vibrational analysis of the title molecule is conducted and the assignments concerned to the observed bands are mentioned with the support of potential energy distribution (PED).The comparison between experimental and theoretical vibrational spectra gives a precise knowledgeof the fundamental vibrational modes and leads to a better interpretation of the experimental Raman and infrared spectra. The theoretical NMR (1H and 13C) analysis is conducted by GIAO method for its structural characterization and compared with experimental chemical shifts. In addition to these studies other analyses such as NLO, FMO, MEP, ELF and LOL have been performed to understand the nature of the molecule. Molecular docking studies carried out to understand more common targeted proteins associated with severe acute respiratory syndrome corona virus (SARS-CoV).

18.
Ovidius University Annals of Chemistry ; 32(2):137-144, 2021.
Artigo em Inglês | Web of Science | ID: covidwho-1613496

RESUMO

In acute conditions, vaccines are very important, although they provide antibodies for fighting against COVID19 for a certain period. It is necessary to produce an anti-viral agent for a usual healing process against SARS CoV-2 which is responsible the pandemic we are living in. Many drugs with benzimidazole main scaffold are still used in a wide variety of treatment procedures. In this case, substituted benzimidazole structures could be good candidates for fighting against COVID-19. Theoretical calculation methods could be a key tool for overcome the difficulties of individual analyzing of each new structure. In this study, new benzimidazole structures were synthesized and characterized for in silico evaluation as anti-viral agent. The molecules were optimized and analyzed for reactivity with Koopmans Theorem. Also, molecular docking simulations were performed for SARS coronavirus main peptidase (PDB ID: 2GTB), COVID-19 main protease (PDB ID: 5R82), and papain-like protease of SARS CoV-2 (PDB ID: 6W9C) crystals.

19.
Sustainability ; 13(24):13887, 2021.
Artigo em Inglês | ProQuest Central | ID: covidwho-1598977

RESUMO

In order to meet the environmental needs caused by large plastic waste accumulation, in the road construction sector, an effort is being made to integrate plastic waste with the function of polymer into asphalt mixtures;with the purpose of improving the mechanical performance of the pavement layers. This study focuses on the effect of a recycled mixture of plastic waste on the chemical, thermal, and rheological properties of designed asphalt blends and on the identification of the most suitable composition blend to be proposed for making asphalt mixture through a dry modification method. Thermo-gravimetric analysis, differential scanning calorimetry, and Fourier transform infrared spectroscopy analysis were carried out to investigate the effect of various concentrations and dimensions of plastic waste (PW) on the neat binder (NB). The frequency sweep test and the multiple stress creep and recovery test were performed to analyze the viscoelastic behavior of the asphalt blends made up of PW in comparison with NB and a commercial modified bitumen (MB). It has been observed that the presence of various types of plastic materials having different melting temperatures does not allow a total melting of PW powder at the mixing temperatures. However, the addition of PW in the asphalt blend significantly improved the aging resistance without affecting the oxidation process of the plastic compound present in the asphalt blend. Furthermore, when the asphalt blend mixed with 20% PW by the weight of bitumen is adopted into the asphalt mixture as polymer, it improves the elasticity and strengthens the mixture better than the mixture containing MB.

20.
Spectrochim Acta A Mol Biomol Spectrosc ; 269: 120725, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: covidwho-1591497

RESUMO

The task of assembling and calculating spectrally significant lines of Vitamin D2 and D3 is related to a wider goal of establishing if it is possible to develop non-invasive optical sensors for these substances present at concentrations on the order of tens of nmol/L. Such a non-invasive in vivo sensor would be helpful for medical considerations, among others, related to multiple sclerosis prevention, reduced risk of mortality in D3-treated acute in-patients admitted with COVID 19, systemic infection, acute respiratory tract infections, including epidemic influenza, community-acquired pneumonia at concentrations <50nmol/L(<20ng/mL), dental health (90-100nmol/L) of 25(OH) D, general health and others. Currently, to determine the concentration of these substances, it is necessary to draw a sample from a vein in ambulatory settings and analyse the sample with the gold standard of mass spectroscopy or immunoassay. In this article Vitamin D optical properties are studied by density functional theory calculations, compared to reported data, and the new calculated and measured D2 and D3 optical absorption lines are presented, as well as the calculations compared with spectral measurements of optical transmission, FTIR ATR and Raman spectra.


Assuntos
COVID-19 , Colecalciferol , Ergocalciferóis , Humanos , SARS-CoV-2 , Análise Espectral Raman , Vitamina D
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