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1.
Huan Jing Ke Xue ; 44(5): 2430-2440, 2023 May 08.
Article in Chinese | MEDLINE | ID: covidwho-20237414

ABSTRACT

To investigate the change characteristics of secondary inorganic ions in PM2.5 at different pollution stages before and after COVID-19, the online monitoring of winter meteorological and atmospheric pollutant concentrations in Zhengzhou from December 15, 2019 to February 15, 2020 was conducted using a high-resolution (1 h) online instrument. This study analyzed the causes of the haze process of COVID-19, the diurnal variation characteristics of air pollutants, and the distribution characteristics of air pollutants at different stages of haze.The results showed that Zhengzhou was mainly controlled by the high-pressure ridge during the haze process, and the weather situation was stable, which was conducive to the accumulation of air pollutants. SNA was the main component of water-soluble ions, accounting for more than 90%. Home isolation measures during COVID-19 had different impacts on the distribution characteristics of air pollutants in different haze stages. After COVID-19, the concentration of PM2.5 in the clean, occurrence, and dissipation stages increased compared with that before COVID-19 but significantly decreased in the development stage. The home isolation policy significantly reduced the high value of PM2.5. The concentrations of NO2, SO2, NH3, and CO were the highest in the haze development stage, showing a trend of first increasing and then decreasing. The concentration of O3 was lowest in the pre-COVID-19 development stage but highest in the post-COVID-19 development stage. The linear correlation between[NH4+]/[SO42-] and[NO3-]/[SO42-] at different time periods before and after COVID-19 was strong, indicating that the home isolation policy of COVID-19 did not change the generation mode of NO3-, and the corresponding reaction was always the main generation mode of NO3-. The correlation between[excess-NH4+] and[NO3-] was high in different periods before COVID-19, and NO3- generation was related to the increase in NH3 or NH4+ in the process of PM2.5 pollution in Zhengzhou.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Humans , Particulate Matter/analysis , Environmental Monitoring/methods , COVID-19/epidemiology , Respiratory Aerosols and Droplets , Air Pollutants/analysis , Air Pollution/analysis , Ions/analysis , Seasons , China/epidemiology
2.
Atmospheric Research ; 287, 2023.
Article in English | Scopus | ID: covidwho-2257808

ABSTRACT

The present study was conducted to investigate the potential of water soluble organic carbon (WSOC) in CCN activation under restricted anthropogenic emissions over a high altitude station, Darjeeling (27.01° N and 88.15° E,∼2200 amsl and covered with huge coniferous forests) in the eastern parts of Himalaya in India. We measured CN, CCN, and ultrafine WSOC (WSOC0.1) during April–May 2020 (COVID-19 lockdown) and compared with the normal period (April–May 2019) to investigate the relative dominance of biogenic over anthropogenic emissions to the aerosol-CCN activation. Though an expected significant decline (53%) in CN concentration was observed, CCN exhibited ∼17% increase during the lockdown period. The activation ratio (AR: CCN/CN) jumped from 0.30 during normal to 0.72 during the lockdown period. The aerosol solubility was also found to be increased during the lockdown period (∼27% decrease in the k- parameter (k)). Lockdown-WSOC was higher (1.62 μg m−3) than the normal-WSOC (1.13 μg m−3) and exhibited better regression with CCN in absence of anthropogenic emissions (Lockdown: R2 = 0.83, p < 0.05;Normal: R2 = 0.40, p < 0.05). Here we hypothesize that under restricted fossil fuel emissions during lockdown (57% decline in NOx), surface ozone was increased by 31%, that in turn favored the photochemical oxidation of biogenic VOCs emitted only from coniferous forest cover to produce huge amount of SOC. The ultrafine "biogenic-only” WSOC (under restricted anthropogenic WSOC during lockdown) participated in CCN activation actively and with higher proficiency compared to the normal period. The study bears immense importance of the role of biogenic emissions in cloud droplet formation over this part of the Himalaya under restricted anthropogenic emissions. The present hypothesis could open a new route of aerosol formation and their CCN activation under high deficiency of anthropogenic emissions. © 2023 Elsevier B.V.

3.
Talanta ; 256: 124320, 2023 May 01.
Article in English | MEDLINE | ID: covidwho-2221396

ABSTRACT

The SARS-CoV-2-related Corona Virus Disease 2019 (COVID-19) epidemic has had a significant negative impact on society and endangered global health. To quickly stop and constrain the pandemic, a SARS-CoV-2 detection technology that is sensitive, quick and reasonably priced is urgently required. The widely used reverse-transcription polymerase chain reaction (RT-PCR) requires complex equipment and a fair amount of time. Reverse transcription-loop-mediated isothermal amplification (RT-LAMP) exhibits significant advantage for early detection of COVID-19 without the requirement for expensive equipment by amplifying a little amount of RNA to a detectable level at isothermal condition. Here, a water-soluble polythiophene-based colorimetric method by combining with RT-LAMP is established for fast and sensitive detection of SARS-CoV-2 RNA. The proposed assay has benefits for the quick detection of SARS-CoV-2 RNA at concentrations as low as 10 aM, or 6 copies/µL.


Subject(s)
COVID-19 , Humans , COVID-19/diagnosis , SARS-CoV-2/genetics , RNA, Viral/genetics , RNA, Viral/analysis , Colorimetry/methods , Nucleic Acid Amplification Techniques/methods , Water , Sensitivity and Specificity
4.
Russ Chem Bull ; 71(11): 2495-2504, 2022.
Article in English | MEDLINE | ID: covidwho-2174764

ABSTRACT

The multistage purposeful synthesis of 5,15-bis(4'-l-N-tyrosinylamidophenyl)-10,20-bis(N-methylpyridin-3'-yl)porphine diiodide was carried out, and the optimum synthesis conditions were determined. 5,15-Bis(4'-nitrophenyl)-10,20-bis(pyridin-3'-yl)porphine served as the starting porphyrin. The structure, individual character, and purity of the target compound were proved by electron spectroscopy, 1H NMR spectroscopy, mass spectrometry (MALDI TOF), and TLC. Specific features of the interaction of the synthesized porphyrin with S-protein of SARS-CoV-2 were studied using spectral and thermochemical methods, including conditions of photoirradiation. The photoirradiation of the synthesized porphyrin in a complex with the SARS-CoV-2 S-protein can result in the partial oxidation of amino acid residues of the protein and distort its primary and secondary structures. The photoirradiation of the S-protein complex with the porphyrin decreases its thermal resistance to melting by 15 °C compared to the free S-protein and causes porphyrin release.

5.
Chiang Mai Journal of Science ; 49(6):1604-1617, 2022.
Article in English | Scopus | ID: covidwho-2155826

ABSTRACT

The goal of this study was to develop pregelatinized starch (P-St) and polyvinyl alcohol (PVOH) films as water-soluble laundry plastic bags to avoid having contact with COVID-19 infected clothes by extrusion method. The effects of pregelatinized starch (P-St) content on the properties of polyvinyl alcohol (PVOH) films were examined. PVOH and P-St blend were compounded by twin-screw extruder with various P-St content of 0, 10, 20, 30, and 40% by weight with fixed glycerol content of 20 phr. The blend films were produced by blown film extrusion. The chemical structure, thermal properties, water-solubility, mechanical properties, and the cross-sections morphological properties of PVOH/G/P-St were characterized. As a result, the formation of intermolecular interactions between PVOH, glycerol and P-St was confirmed by FTIR. Moreover, the addition of P-St on PVOH could reduce the thermal stability due to the content of P-St with amylose, a substance of amorphous structure, affecting the chains flexibility of PVOH/G/P-St. From the differential scanning calorimeter result, the glass transition temperature was increased with the increment of P-St content because the chains entanglement between PVOH and P-St had affected the reduction in crystallinity and led to the decrement of the melting temperature. Furthermore, the water solubility would strongly be dependent on the percentage of the gelatinized starch (%GS). The solubility decreased as the percentage of the GS increased. In addition, PVOH with 20% of P-St film possessed the highest value in tensile strength and modulus, and the particles of P-St have a good distribution in PVOH/G indicating to stronger interaction of P-St and PVOH/G. © 2022, Chiang Mai University. All rights reserved.

6.
Tissue Engineering - Part A ; 28(Supplement 3):315, 2022.
Article in English | EMBASE | ID: covidwho-2134751

ABSTRACT

Lateral flow assays are low-cost devices suitable for point-of-care testing, particularly in low-resource settings. However, some of the lateral flow assays exhibit limited diagnostic utility because the assays can only sample <100uL specimen and the biomarker concentration is significantly lower than the assay detection limit, which compromise the sensitivity. To address the challenge, we have developed the osmoprocessor that statically and spontaneously concentrated biomarkers via osmosis. The specimen in the device interfaces with the aqueous polymer solution via a dialysis membrane. The polymer solution induces an osmotic pressure difference that extracts water from the specimen, while the membrane retains the biomarkers. The evaluation demonstrated that osmosis induced by various water-soluble polymers efficiently extracted water, ca. 15 mL/hr. The water transport kinetics can be adjusted by varying polymer molecular weights and mass concentrations. The osmoprocessor concentrated the specimens to improve the lateral flow assays' detection limits for the model analytes-human chorionic gonadotropin and SARS-CoV-2 nucleocapsid protein. The device processed a 10 mL specimen into a 100uL concentrated sample. Then, the lateral flow assays detected the corresponding biomarkers in the concentrated specimens. The test band intensities of the assays with the concentrated specimens were very similar to the reference assays with 100-fold concentrations. The mass spectrometry analysis estimated the SARSCoV- nucleocapsid protein concentration increased ca. 200-fold after the osmosis. With its simplicity and flexibility, this device demonstrates a great potential to be utilized in conjunction with the existing lateral flow assays for enabling highly sensitive detection of dilute target analytes.

7.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae ; 42(7):53-62, 2022.
Article in Chinese | Scopus | ID: covidwho-2056466

ABSTRACT

In order to study the pollution levels of PM2.5 and water-soluble inorganic ions(WSIIs)in the towns of southern Gansu, PM2.5 samples were collected quarterly in Cheng County of Gansu from April 2019 to February 2020. Their characteristics of variation were analyzed, and the sources were apportioned using correlation and principal component analysis. The results showed that the mean annual mass concentration of PM2.5 was(57.2±26.9)μg·m-3 in Cheng County of Gansu Province. The seasonal variation of PM2.5 concentration was represented by winter>spring>autumn>summer during the sampling period, and the concentrations in winter were about 1.9 times than that in summer. The annually good air quality rate was 81%, of which 100% in summer. The ranking of WSII concentrations was SO42->NO3->Na+>NH4+>Ca2+>K+>Cl->Mg2+.SNA is the highest water-soluble ions, accounting for 70.1% of the concentration of eight main water-soluble ions. The mean ratio of ρ(NO3-)/ρ(SO42-)was 0.6, indicating that fixed sources such as industrial and agricultural production and fossil fuel combustion emissions, was the major source for particulate pollution. During the 2019 coronavirus epidemic, control measures had a significant impact on the concentration of PM2.5 and SNA in water-soluble ions, and the mean concentration of PM2.5 was reduced by 44.2%. Source apportionment showed that WSIIs in PM2.5 were mainly from fossil fuel combustion, biomass combustion, secondary formation and road construction dust, etc. © 2022 Science Press. All rights reserved.

8.
Journal of Molecular Liquids ; 366, 2022.
Article in English | Scopus | ID: covidwho-2049679

ABSTRACT

An innovative sonication method has been developed to produce inclusion complexes (ICs) of Oseltamivir (OTV) which is a potentially water-soluble anti-viral agent with lesser cytotoxicity. Proton signals and chemical shifts of OTV without any ambiguity confirm the formation of ICs with β-Cyclodextrin (B-CD) and Hydroxypropyl-β-cyclodextrin (H-CD). ICs are also supported by their atomic percentages as secondary evidence using XPS analysis. Analysis of drug release at three pH levels revealed the slow release of the OTV from ICs and also suitable for viral inactivation. A very less cytotoxic ability on cancer cell lines and enhanced the viral inactivation of OTV after being made into water-soluble ICs. © 2022 Elsevier B.V.

9.
J Pharm Biomed Anal ; 221: 115057, 2022 Nov 30.
Article in English | MEDLINE | ID: covidwho-2031477

ABSTRACT

A potentially active water-soluble anti-viral with lesser toxic material from the Oseltamivir (OTV) has been produced by the sonication method. The formed material has been further characterized by UV-visible, FT-IR, powder XRD, SEM, TGA/DTA, ROESY, XPS, AFM and etc., The results of DFT calculation have proven that inclusion complexes (ICs) are theoretically and energetically more advantageous models and structures have also been proposed based on the results. Analysis of drug release has been carried out at three pH levels, and it is revealed the analysis is most helpful at acidic pH levels for the ICs with S-CD over H-CD. Over OTV without CDs, OTV:S-CD-ICs exhibited a very less cytotoxic ability on cancer cell lines than ICs with M-CD. ICs enhanced the coronavirus inactivation nature of OTV. This study provides for the first time a full characterization of ICs of OTV with CDs and highlights the impact of complexation on pharmacological activity.


Subject(s)
Coronavirus , Cyclodextrins , beta-Cyclodextrins , Cyclodextrins/chemistry , Oseltamivir/pharmacology , Powders , Solubility , Spectroscopy, Fourier Transform Infrared , Sulfates , Water/chemistry , beta-Cyclodextrins/chemistry , beta-Cyclodextrins/pharmacology
10.
Nanomaterials (Basel) ; 12(15)2022 Jul 24.
Article in English | MEDLINE | ID: covidwho-1994121

ABSTRACT

Unlike traditional small molecule drugs, fullerene is an all-carbon nanomolecule with a spherical cage structure. Fullerene exhibits high levels of antiviral activity, inhibiting virus replication in vitro and in vivo. In this review, we systematically summarize the latest research regarding the different types of fullerenes investigated in antiviral studies. We discuss the unique structural advantage of fullerenes, present diverse modification strategies based on the addition of various functional groups, assess the effect of structural differences on antiviral activity, and describe the possible antiviral mechanism. Finally, we discuss the prospective development of fullerenes as antiviral drugs.

11.
Atmospheric Environment ; : 119304, 2022.
Article in English | ScienceDirect | ID: covidwho-1977051

ABSTRACT

A scarce distribution of the PM2.5 chemical compositions monitors reduces the applicability of scientific information for policymakers to assess the effectiveness of air pollution control strategies. There is an urgent need for a spatial-temporal prediction model for characterizing PM2.5 chemical compositions to assess exposure risks and develop effective air pollutants reduction strategies. In this study, the spatial-temporal variations of NO3− and SO42− were characterized using a hybrid multi-step ahead neural network (MSA-NN)/Kriging model in the urban areas with limited PM2.5 constituents monitoring stations. A meteorological normalization technique was further applied to develop a de-weather model to investigate temporal variations of air pollutants during the level 3 COVID-19 alert in central Taiwan. The MSA-NN algorithm could predict 94% and 91% of NO3− and SO42−, respectively, at the t+1-time horizon predictions. Based on the predicted results using the present de-weather model, the reduction in primary emissions attributed to the impact of COVID-19 during the level 3 alert was found to dominate the temporal air pollutant concentrations in central Taiwan. The present model could provide applicable and accurate high resolution of spatial-temporal NO3− and SO42− datasets in an area with limited PM2.5 chemical composition measurement. The present model could also be potentially applied to facilitate hotspot identification and human exposure assessment. The present Artificial Neural Network-based de-weather model is applicable to predict meteorological normalized time series air pollutant concentrations, which could be used to verify the effects of the meteorological parameters and primary emissions on the variations in air quality during the implementation of a specific air quality control strategy or changes in anthropogenic activities.

12.
Atmosphere ; 13(7):1042, 2022.
Article in English | ProQuest Central | ID: covidwho-1963693

ABSTRACT

Previous studies have determined biomass burning as a major source of air pollutants in the ambient air in Thailand. To analyse the impacts of meteorological parameters on the variation of carbonaceous aerosols and water-soluble ionic species (WSIS), numerous statistical models, including a source apportionment analysis with the assistance of principal component analysis (PCA), hierarchical cluster analysis (HCA), and artificial neural networks (ANNs), were employed in this study. A total of 191 sets of PM2.5 samples were collected from the three monitoring stations in Chiang-Mai, Bangkok, and Phuket from July 2020 to June 2021. Hotspot numbers and other meteorological parameters were obtained using NOAA-20 weather satellites coupled with the Global Land Data Assimilation System. Although PCA revealed that crop residue burning and wildfires are the two main sources of PM2.5, ANNs highlighted the importance of wet deposition as the main depletion mechanism of particulate WSIS and carbonaceous aerosols. Additionally, Mg2+ and Ca2+ were deeply connected with albedo, plausibly owing to their strong hygroscopicity as the CCNs responsible for cloud formation.

13.
9th International Work-Conference on Bioinformatics and Biomedical Engineering, IWBBIO 2022 ; 13347 LNBI:83-89, 2022.
Article in English | Scopus | ID: covidwho-1919715

ABSTRACT

Biomarkers seem to play an important role in understanding various diseases’ nature, course and management, including respiratory ones. Yet, discovering verifiable and validated ones, that are useful in pulmonology, is challenging and constant. A special body specimen that has been characterized as a matrix of biomarkers, is the exhaled breath condensate (EBC). It is a fluid resulting from freezing the exhaled air. Water is its main constituent. The rest is a rich mix of water-soluble volatile compounds and aerosol droplets of airway lining fluid. The droplets carry non-volatile organic compounds. Their concentration is very small and the techniques applied to measure it are very accurate and sensitive. The content of the exhaled breath condensate reflects important processes taking place in the lungs, such as inflammation and oxidative stress, which are the basis of respiratory diseases’ pathophysiology. It seems that it has a role in diagnosis, monitoring, stratification and therapy of respiratory diseases, including COVID19. This paper presents information on exhaled breath condensate and highlights its importance as a potential source of biomarkers. © 2022, Springer Nature Switzerland AG.

14.
Frontiers in Earth Science ; 10:14, 2022.
Article in English | Web of Science | ID: covidwho-1869357

ABSTRACT

The research of atmospheric aerosol in mountain glacier areas has attracted more and more people's attention. For the first time, a field observation study of total suspended particles (TSPs) for four seasons from September 2019 to August 2020 was carried out at the Tianshan Glaciological Station in the source area of Urumqi River, East Tianshan Mountains, China. The TSPs presented typical seasonal characteristics of high in autumn and low in winter, with the annual average value of 181 +/- 170 mu g m(-3). Concentrations of Ca2+, SO42-, NO3-, Cl-, NH4+ and K+, OC, EC were elevated in autumn. The influence of stationary source emissions was stronger than mobile sources, which was explained by the average ratio of NO3-/SO42- (0.31 +/- 0.17). The concentration of secondary organic carbon (SOC) was higher in summer and autumn, especially in summer, indicating that secondary formation processes of organic aerosols were frequent in summer. Impact of fossil fuel combustion sources were evident over the Glaciers, corroborated by the diagnostic mass ratios of OC/EC (0-21.4, 3.38) and K+/EC (0-0.31, 0.08). The factor analysis illustrated that aerosols were mainly affected by rock salt, dust, coal combustion, and automobile exhaust. The local sources made significant contributions to TSPs in the source of Urumqi River by the results of Results of Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and potential source contribution function (PSCF).

15.
Adv Exp Med Biol ; 1352: 159-172, 2021.
Article in English | MEDLINE | ID: covidwho-1669702

ABSTRACT

INTRODUCTION: The emergence of a new member of the Coronaviridae family, which caused the 2020 pandemic, requires detailed research on the evolution of coronaviruses, their structure and properties, and interaction with cells. Modern nanobiotechnologies can address the many clinical challenges posed by the COVID-19 pandemic. In particular, they offer new therapeutic approaches using biocompatible nanostructures with "specific" antiviral activity. Therefore, the nanosized spherical-like molecule (0.72 nm in diameter) composed of 60 carbon atoms, C60 fullerene, is of interest in terms of fighting coronaviruses due to its high biological activity. In here, we aim to evaluate the effectiveness of anticoronavirus action of water-soluble pristine C60 fullerene in the model and in vitro systems. As a model, apathogenic for human coronavirus, we used transmissible gastroenteritis virus of swine (TGEV), which we adapted to the BHK-21 cell culture (kidney cells of a newborn Syrian hamster). METHODS: The shape and size of the particles present in C60 fullerene aqueous colloidal solution (C60FAS) of given concentration, as well as C60FAS stability (value of zeta potential) were studied using microscopic (STM, scanning tunneling microscopy, and AFM, atomic force microscopy) and spectroscopic (DLS, dynamic light scattering) methods. The cytopathic effect of TGEV was determined with the help of a Leica DM 750 microscope and the degree of monolayer changes in cells was assessed. The microscopy of the viral suspension was performed using a high resolution transmission electron microscope (HRTEM; JEM-1230, Japan). Finally, the search for and design of optimal possible complexes between C60 fullerene and target proteins in the structure of SARS-CoV-2 coronavirus, evaluation of their stability in the simulated cellular environment were performed using molecular dynamics and docking methods. RESULTS: It was found that the maximum allowable cytotoxic concentration of C60 fullerene is 37.5 ± 3.0 µg/ml. The investigated C60FAS reduces the titer of coronavirus infectious activity by the value of 2.00 ± 0.08 TCID50/ml. It was shown that C60 fullerene interacts directly with SARS-CoV-2 proteins, such as RdRp (RNA-dependent RNA polymerase) and 3CLpro (3-chymotrypsin-like protease), which is critical for the life cycle of the coronavirus and, thus, inhibits its functional activity. In both cases, C60 fullerene fills the binding pocket and gets stuck there through stacking and steric interactions. CONCLUSION: Pioneer in vitro study to identify the anticoronavirus activity of water-soluble pristine C60 fullerenes indicates that they are highly promising for further preclinical studies, since a significant inhibition of the infectious activity of swine coronavirus of transmissible gastroenteritis in BHK-21 cell culture was found. According to molecular modeling results, it was shown that C60 fullerene can create the stable complexes with 3CLpro and RdRp proteins of SARS-CoV-2 coronavirus and, thus, suppress its functional activity.


Subject(s)
COVID-19 , Fullerenes , Animals , Fullerenes/pharmacology , Humans , Pandemics , SARS-CoV-2 , Swine , Water
16.
Med Hypotheses ; 147: 110480, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1174424

ABSTRACT

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus is now considered a global public health threat. The primary focus has been on reducing the viral spread and treating respiratory symptoms; as time goes on, the impact of COVID-19 on neurological and haemostatic systems becomes more evident. The clinical data suggest that platelet hyperactivity plays a role in the pathology of COVID-19 from its onset and that platelets may serve critical functions during COVID-19 progression. Hyperactivation of blood platelets and the coagulation system are emerging as important drivers of inflammation and may be linked to the severity of the 'cytokine storm' induced in severe cases of COVID-19, in which disseminated intravascular coagulation, and platelet hyperactivity are associated with poor prognosis and increased risk of mortality. We propose that targeting platelet hyperactivity in the early stages of COVID-19 infection may reduce the immunothrombotic complications of COVID-19 and subdue the systemic inflammatory response. Lowering baseline platelet activity may be of particular importance for higher-risk groups. As an alternative to antiplatelet drugs, an inappropriate intervention in public health, we propose that the dietary antiplatelet agent Fruitflow®, derived from tomatoes, may be considered a suitable therapy. Fruitflow® contains antiplatelet and anti-inflammatory compounds that target the mechanisms of platelet activation specific to COVID-19 and can be considered a safe and natural antiplatelet regime.


Subject(s)
Blood Platelets/cytology , COVID-19/blood , Plant Extracts/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Solanum lycopersicum , Anti-Inflammatory Agents , Blood Coagulation , Blood Pressure , COVID-19/complications , Disease Progression , Humans , Immunoglobulin G , Inflammation/pathology , Models, Theoretical , Platelet Activation , Prognosis , Thrombosis
17.
Environ Pollut ; 271: 116298, 2021 Feb 15.
Article in English | MEDLINE | ID: covidwho-987653

ABSTRACT

To control the spread of the 2019 novel coronavirus (COVID-19), China imposed rigorous restrictions, which resulted in great reductions in pollutant emissions. This study examines the characteristics of air pollutants, including PM2.5 (particles with aerodynamic diameters < 2.5 µm), gas pollutants, water-soluble ions (WSIs), black carbon (BC) and elements, as well as the source apportionment of PM2.5 in Suzhou before, during and after the Chinese New Year (CNY) holiday of 2020 (when China was under an unprecedented state of lockdown to restrict the COVID-19 outbreak). Compared to those before CNY, PM2.5, BC, SNA (sulfate, nitrate and ammonium), other ions, elements, and NO2 and CO mass concentrations decreased by 9.9%-64.0% during CNY. The lockdown policy had strong (weak) effects on the diurnal variations in aerosol chemical compositions (gas pollutants). Compared to those before CNY, source concentrations and contributions of vehicle exhaust during CNY decreased by 72.9% and 21.7%, respectively. In contrast, increased contributions from coal combustion and industry were observed during CNY, which were recorded to be 2.9 and 1.7 times higher than those before CNY, respectively. This study highlights that the lockdown policy that was imposed in Suzhou during CNY not only reduced the mass concentrations of air pollutants but also modified their diurnal variations and the source contributions of PM2.5, which revealed the complex responses of PM2.5 sources to the rare, low emissions of anthropogenic pollutants that occurred during the COVID-19 lockdown.


Subject(s)
Air Pollutants , COVID-19 , Aerosols/analysis , Air Pollutants/analysis , China , Communicable Disease Control , Environmental Monitoring , Humans , Particulate Matter/analysis , SARS-CoV-2 , Vehicle Emissions/analysis
18.
Pharmaceuticals (Basel) ; 13(9)2020 Aug 26.
Article in English | MEDLINE | ID: covidwho-828288

ABSTRACT

In the last decades, organoselenium compounds gained interest due to their important biological features. However, the lack of solubility, which characterizes most of them, makes their actual clinical exploitability a hard to reach goal. Selenosugars, with their intrinsic polarity, do not suffer from this issue and as a result, they can be conceived as a useful alternative. The aim of this review is to provide basic knowledge of the synthetic aspects of selenosugars, selenonium salts, selenoglycosides, and selenonucleotides. Their biological properties will be briefly detailed. Of course, it will not be a comprehensive dissertation but an analysis of what the authors think is the cream of the crop of this interesting research topic.

19.
QRB Discov ; 1: e4, 2020 Apr 09.
Article in English | MEDLINE | ID: covidwho-659322

ABSTRACT

Cytokine release syndrome (CRS), or 'cytokine storm', is the leading side effect during chimeric antigen receptor (CAR)-T therapy that is potentially life-threatening. It also plays a critical role in viral infections such as Coronavirus Disease 2019 (COVID-19). Therefore, efficient removal of excessive cytokines is essential for treatment. We previously reported a novel protein modification tool called the QTY code, through which hydrophobic amino acids Leu, Ile, Val and Phe are replaced by Gln (Q), Thr (T) and Tyr (Y). Thus, the functional detergent-free equivalents of membrane proteins can be designed. Here, we report the application of the QTY code on six variants of cytokine receptors, including interleukin receptors IL4Rα and IL10Rα, chemokine receptors CCR9 and CXCR2, as well as interferon receptors IFNγR1 and IFNλR1. QTY-variant cytokine receptors exhibit physiological properties similar to those of native receptors without the presence of hydrophobic segments. The receptors were fused to the Fc region of immunoglobulin G (IgG) protein to form an antibody-like structure. These QTY code-designed Fc-fusion receptors were expressed in Escherichia coli and purified. The resulting water-soluble fusion receptors bind to their respective ligands with K d values affinity similar to isolated native receptors. Our cytokine receptor-Fc-fusion proteins potentially serve as an antibody-like decoy to dampen the excessive cytokine levels associated with CRS and COVID-19 infection.

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