Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 52
Filter
1.
Aerosol and Air Quality Research ; 23(5), 2023.
Article in English | Web of Science | ID: covidwho-20243921

ABSTRACT

PM2.5 was continuously collected in Ho Chi Minh City (HCMC), Vietnam, during the period from September 2019 to August 2020, which included the period of socioeconomic suppression caused by restrictions imposed in the face of the coronavirus disease of 2019. The concentrations of PM2.5 mass, water-soluble ions (WSIs), organic carbon (OC), elemental carbon (EC), and water-soluble organic carbon (WSOC) were determined to evaluate the seasonal variations in PM2.5, the effect of socioeconomic suppression on PM2.5, and potential PM2.5 sources in HCMC. The PM2.5 mass concentration during the sampling period was 28.44 +/- 11.55 mu g m(-3) (average +/- standard deviation). OC, EC, and total WSIs accounted for 30.7 +/- 6.6%, 9.7 +/- 2.9%, and 24.9 +/- 6.6% of the PM2.5 mass, respectively. WSOC contributed 46.4 +/- 10.1% to OC mass. NO3-, SO42-, and NH4+ were the dominant species in WSIs (72.7 +/- 17.7% of the total WSIs' mass). The concentrations of PM2.5 mass and total WSIs during the rainy season were lower than those during the dry season, whereas the concentrations of carbonaceous species during the rainy season were higher. The concentrations of PM2.5 mass and chemical species during the socioeconomic suppression period significantly decreased by 45%-61% compared to the values before this period. The OC/EC ratio (3.28 +/- 0.61) and char-EC/soot-EC (4.88 +/- 2.72) suggested that biomass burning, coal combustion, vehicle emissions, cooking activities are major PM2.5 sources in HCMC. Furthermore, the results of a concentration-weighted trajectory analysis suggested that the geological sources of PM2.5 were in the local areas of HCMC and the northeast provinces of Vietnam (where coal-fired power plants are located).

2.
Advances in Nanotechnology for Marine Antifouling ; : 271-302, 2023.
Article in English | Scopus | ID: covidwho-20241760

ABSTRACT

Infectious diseases caused by different pathogens (parasites, protozoa, bacteria, viruses, and fungi) have affected the world at various times in the form of epidemics and pandemics. The coronavirus has also directly affected the world's economy and public health. Various drugs such as antibiotics, antimicrobials, antifungals, and antivirals have been investigated to combat these diseases. However, these fatal infections are still a major concern because of their transmission through contaminated surfaces, human-to-human contact, airborne diffusion, and microbial resistance. Therefore, considerable efforts are required to suppress the transmission of these pathogens. Smart coatings are able to sense their environment and adapt their properties according to the stimulus. Furthermore, various parameters of coating technology can be controlled on a molecular level to influence the morphology. Nanomaterial (NM)-based smart coatings are 99.99% effective against bacteria, viruses, and fungi because of the unique properties of NMs involved. Moreover, NM-based smart coatings are 1000-fold more efficient than traditional coating technologies. Besides their antifungal, antiviral, and antibacterial application, they are anticorrosive and self-cleaning. This chapter summarizes various NM-based smart coatings (organic, inorganic, and carbon) implemented in antibacterial, antifungal, and antiviral applications. Furthermore, the application of these coatings in various fields and their associated challenges will be discussed. © 2023 Elsevier Inc. All rights reserved.

3.
Advanced Photonics Research ; 3(6), 2022.
Article in English | Web of Science | ID: covidwho-2310533

ABSTRACT

The need to sense and track in real time through sustainable and multifunctional labels is exacerbated by the COVID-19 pandemic, where the simultaneous measurement of body temperature and the fast tracking of people is required. One of the big challenges is to develop effective low-cost systems that can promote healthcare provision everywhere and for that, smarter and personalized Internet of things (IoT) devices are a pathway in large exploration, toward cost reduction and sustainability. Using the concept of color-multiplexed quick response (QR) codes, customized smart labels formed by two independent layers and smart location patterns provide simultaneous tracking and multiple synchronous temperature reading with maximum sensitivity values of 8.5% K-1 in the physiological temperature range, overwhelming the state-of-the-art optical sensor for healthcare services provided electronically via the internet (eHealth) and mobile sensors (mHealth).

4.
Eur J Med Chem Rep ; 8: 100104, 2023 Aug.
Article in English | MEDLINE | ID: covidwho-2299921

ABSTRACT

In light of the current SARS-CoV-2 outbreak, about one million research papers (articles, reviews, communications, etc.) were published in the last one and a half years. It was also noticed that in the past few years; infectious diseases, mainly those of viral origin, burdened the public health systems worldwide. The current wave of the Covid-19 pandemic has unmasked critical demand for compounds that can be swiftly mobilized for the treatment of re-emerging or emerging viral infections. With the potential chemical and structural characteristics of organic motifs, the coordination compounds might be a promising and flexible option for drug development. Their therapeutic consequence may be tuned by varying metal nature and its oxidation number, ligands characteristics, and stereochemistry of the species formed. The emerging successes of cisplatin in cancer chemotherapy inspire researchers to make new efforts for studying metallodrugs as antivirals. Metal-based compounds have immense therapeutic potential in terms of structural diversity and possible mechanisms of action; therefore, they might offer an excellent opportunity to achieve new antivirals. This review is an attempt to summarize the current status of antiviral therapies against SARS-CoV-2 from the available literature sources, discuss the specific challenges and solutions in the development of metal-based antivirals, and also talk about the possibility to accelerate discovery efforts in this direction.

5.
Environ Dev Sustain ; : 1-26, 2023 Apr 04.
Article in English | MEDLINE | ID: covidwho-2297470

ABSTRACT

This article focuses on India's inorganic solid waste disposal problem, with a particular emphasis on plastic and mixed waste. It aims to identify the current COVID-19 pandemic situation as well as provide a suitable disposal technique for wastes that are specifically related to municipal solid waste management. We propose an integrated approach to disposing of paper and plastic and mixed wastes in an interval-valued q-rung orthopair fuzzy (IVq-ROF) environment for this problem. In this case, we use the FUCOM method to calculate the weight values of the criteria and the MABAC method to rank the alternatives based on the chosen criteria. To confirm the effectiveness of the proposed method, a numerical illustration is provided, and validation of the suggested method is also shown.

6.
ACS Appl Mater Interfaces ; 15(16): 20483-20494, 2023 Apr 26.
Article in English | MEDLINE | ID: covidwho-2297232

ABSTRACT

Surface ligands play a critical role in controlling and defining the properties of colloidal nanocrystals. These aspects have been exploited to design nanoparticle aggregation-based colorimetric sensors. Here, we coated 13-nm gold nanoparticles (AuNPs) with a large library of ligands (e.g., from labile monodentate monomers to multicoordinating macromolecules) and evaluated their aggregation propensity in the presence of three peptides containing charged, thiolate, or aromatic amino acids. Our results show that AuNPs coated with the polyphenols and sulfonated phosphine ligands were good choices for electrostatic-based aggregation. AuNPs capped with citrate and labile-binding polymers worked well for dithiol-bridging and π-π stacking-induced aggregation. In the example of electrostatic-based assays, we stress that good sensing performance requires aggregating peptides of low charge valence paired with charged NPs with weak stability and vice versa. We then present a modular peptide containing versatile aggregating residues to agglomerate a variety of ligated AuNPs for colorimetric detection of the coronavirus main protease. Enzymatic cleavage liberates the peptide segment, which in turn triggers NP agglomeration and thus rapid color changes in <10 min. The protease detection limit is 2.5 nM.


Subject(s)
Colorimetry , Metal Nanoparticles , Colorimetry/methods , Gold/chemistry , Metal Nanoparticles/chemistry , Polymers , Ligands
7.
Environ Sci Technol ; 2023 Apr 28.
Article in English | MEDLINE | ID: covidwho-2305593

ABSTRACT

Fine particulate matter (PM2.5) chemical composition has strong and diverse impacts on the planetary environment, climate, and health. These effects are still not well understood due to limited surface observations and uncertainties in chemical model simulations. We developed a four-dimensional spatiotemporal deep forest (4D-STDF) model to estimate daily PM2.5 chemical composition at a spatial resolution of 1 km in China since 2000 by integrating measurements of PM2.5 species from a high-density observation network, satellite PM2.5 retrievals, atmospheric reanalyses, and model simulations. Cross-validation results illustrate the reliability of sulfate (SO42-), nitrate (NO3-), ammonium (NH4+), and chloride (Cl-) estimates, with high coefficients of determination (CV-R2) with ground-based observations of 0.74, 0.75, 0.71, and 0.66, and average root-mean-square errors (RMSE) of 6.0, 6.6, 4.3, and 2.3 µg/m3, respectively. The three components of secondary inorganic aerosols (SIAs) account for 21% (SO42-), 20% (NO3-), and 14% (NH4+) of the total PM2.5 mass in eastern China; we observed significant reductions in the mass of inorganic components by 40-43% between 2013 and 2020, slowing down since 2018. Comparatively, the ratio of SIA to PM2.5 increased by 7% across eastern China except in Beijing and nearby areas, accelerating in recent years. SO42- has been the dominant SIA component in eastern China, although it was surpassed by NO3- in some areas, e.g., Beijing-Tianjin-Hebei region since 2016. SIA, accounting for nearly half (∼46%) of the PM2.5 mass, drove the explosive formation of winter haze episodes in the North China Plain. A sharp decline in SIA concentrations and an increase in SIA-to-PM2.5 ratios during the COVID-19 lockdown were also revealed, reflecting the enhanced atmospheric oxidation capacity and formation of secondary particles.

8.
Applied Sciences ; 13(3):1646, 2023.
Article in English | ProQuest Central | ID: covidwho-2277330

ABSTRACT

There is a great deficiency in the collection and disposal of solid waste, with a considerable amount disposed of in dumps instead of in landfills. In this sense, the objective of this research is to propose a solid waste mitigation plan through recovery in the District of Santa Rosa, Ayacucho. For this, a solid waste characterization plan was executed in eight days, and through ANOVA it was shown that there is a significant difference in means between business pairs except between a bakery and a hotel. Through clustering, zones A and B are highly correlated, reflecting that the amount of organic waste was greater than inorganic waste. In the organic waste valorization plan, the results through ANOVA indicate a significant difference for monthly and daily averages, and the clustering shows the different behavior of each month, drawing attention to August, concluding that the valorization pilot plan is viable due to the contribution of a large amount of organic solid waste to the valorization plant.

9.
Inorganics ; 11(2):60, 2023.
Article in English | ProQuest Central | ID: covidwho-2262259

ABSTRACT

Two tetranuclear [Zn4Cl2(ClQ)6]·2DMF (1) and [Zn4Cl2(ClQ)6(H2O)2]·4DMF (2), as well as three dinuclear [Zn2(ClQ)3(HClQ)3]I3 (3), [Zn2(dClQ)2(H2O)6(SO4)] (4) and [Zn2(dBrQ)2(H2O)6(SO4)] (5), complexes (HClQ = 5-chloro-8-hydroxyquinoline, HdClQ = 5,7-dichloro-8-hydroxyquinoline and HdBrQ = 5,7-dibromo-8-hydroxyquinoline) were prepared as possible anticancer or antimicrobial agents and characterized by IR spectroscopy, elemental analysis and single crystal X-ray structure analysis. The stability of the complexes in solution was verified by NMR spectroscopy. Antiproliferative activity and selectivity of the prepared complexes were studied using in vitro MTT assay against the HeLa, A549, MCF-7, MDA-MB-231, HCT116 and Caco-2 cancer cell lines and on the Cos-7 non-cancerous cell line. The most sensitive to the tested complexes was Caco-2 cell line. Among the tested complexes, complex 3 showed the highest cytotoxicity against all cell lines. Unfortunately, all complexes showed only poor selectivity to normal cells, except for complex 5, which showed a certain level of selectivity. Antibacterial potential was observed for complex 5 only. Moreover, the DNA/BSA binding potential of complexes 1–3 was investigated by UV-vis and fluorescence spectroscopic methods.

10.
Environ Pollut ; 323: 121355, 2023 Apr 15.
Article in English | MEDLINE | ID: covidwho-2257675

ABSTRACT

Hourly observations in northern China city of Taiyuan were performed to compare secondary inorganic aerosol (SIA) reaction mechanisms, and emission effects on SIA during the pre-lock and COVID-19 lock days. Emission control implemented and meteorological conditions during lock days both caused beneficial impact on air quality. NO2 showed the highest decrease ratio of -49.5%, while the relative fraction of NO3- in PM2.5 increased the most (2.7%). Source apportionment revealed the top three contributors to PM2.5 were secondary formation (SF), coal combustion (CC), and vehicle exhaust (VE) during both pre-lock and lock days. EC lock/pre were all lower than 1, suggesting the overall reduction of primary emissions during lock days, while the higher ratio of (SIA/EC) lock/pre (1.01-1.36) indicated the enhanced secondary formation in lock days. The ratio of SIA of pollution to clean days during lock periods considerably higher by 23.7% compared with that in pre-lock periods, which was indicated SIA secondary formation was more pronounced and contributed great to pollution days in lock periods though secondary formation existed in pre-lock and lock periods. Enhanced secondary formation of NO3- and SO42- during lock days might be mainly due to the increased in aqueous and gas-phase reactions, respectively. Except for SF, high contribution of VE and CC were also important for high SIA concentration in pre-lock and lock days, respectively. The decreased contribution of VE weakens its contribution to SIA formation, indicating the effectiveness of VE emission control, as confirmed during the COVID-19 pandemic. This study highlights the aqueous and gas-phase reactions for nitrate and sulfate, respectively, which contributed to heavy pollution, as well as indicated the important role of VE on SIA formation, suggesting the urgent need to further strengthen controls on vehicle emissions.


Subject(s)
Air Pollutants , Air Pollution , COVID-19 , Humans , Air Pollutants/analysis , Particulate Matter/analysis , Pandemics , Prospective Studies , Seasons , Environmental Monitoring , Communicable Disease Control , Respiratory Aerosols and Droplets , Air Pollution/analysis , China , Vehicle Emissions/analysis , Water , Coal
11.
Bioeng Transl Med ; 8(2): e10421, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2282614

ABSTRACT

The first publication of micro- and nanotechnology in medicine was in 1798 with the use of the Cowpox virus by Edward Jenner as an attenuated vaccine against Smallpox. Since then, there has been an explosion of micro- and nanotechnologies for medical applications. The breadth of these micro- and nanotechnologies is discussed in this piece, presenting the date of their first report and their latest progression (e.g., clinical trials, FDA approval). This includes successes such as the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines from Pfizer, Moderna, and Janssen (Johnson & Johnson) as well as the most popular nanoparticle therapy, liposomal Doxil. However, the enormity of the success of these platforms has not been without challenges. For example, we discuss why the production of Doxil was halted for several years, and the bankruptcy of BIND therapeutics, which relied on a nanoparticle drug carrier. Overall, the field of micro- and nanotechnology has advanced beyond these challenges and continues advancing new and novel platforms that have transformed therapies, vaccines, and imaging. In this review, a wide range of biomedical micro- and nanotechnology is discussed to serve as a primer to the field and provide an accessible summary of clinically relevant micro- and nanotechnology platforms.

12.
Small ; 19(12): e2206153, 2023 03.
Article in English | MEDLINE | ID: covidwho-2173458

ABSTRACT

Natural membrane vesicles, including extracellular vesicles and enveloped viruses, participate in various events in vivo. To study and manipulate these events, biomembrane-coated nanoparticles inspired by natural membrane vesicles are developed. Herein, an efficient method is presented to prepare organic-inorganic hybrid materials in high yields that can accommodate various lipid compositions and particle sizes. To demonstrate this method, silica nanoparticles are passed through concentrated lipid layers prepared using density gradient centrifugation, followed by purification, to obtain lipid membrane-coated nanoparticles. Various lipids, including neutral, anionic, and cationic lipids, are used to prepare concentrated lipid layers. Single-particle analysis by imaging flow cytometry determines that silica nanoparticles are uniformly coated with a single lipid bilayer. Moreover, cellular uptake of silica nanoparticles is enhanced when covered with a lipid membrane containing cationic lipids. Finally, cell-free protein expression is applied to embed a membrane protein, namely the Spike protein of severe acute respiratory syndrome coronavirus 2, into the coating of the nanoparticles, with the correct orientation. Therefore, this method can be used to develop organic-inorganic hybrid nanomaterials with an inorganic core and a virus-like coating, serving as carriers for targeted delivery of cargos such as proteins, DNA, and drugs.


Subject(s)
COVID-19 , Nanoparticles , Humans , Lipid Bilayers , Silicon Dioxide , Particle Size
13.
Frontiers in Materials ; 9, 2022.
Article in English | Web of Science | ID: covidwho-2163030

ABSTRACT

Nanomaterials have played a significant role in effectively combating the global SARS-CoV-2 pandemic that began in December 2019 through the development of vaccines as well as antiviral therapies. These versatile, tunable materials can interact and deliver a broad range of biologically relevant molecules for preventing COVID-19 infection, generating immunity against COVID-19, and treating infected patients. Application of these nanomaterials and nanotechnologies can further be investigated in conjunction with disease models of COVID-19 and this holds immense potential for accelerating vaccine or therapeutic process development further encouraging the elimination of animal model use during preclinical stages. This review examines the existing literature on COVID-19 related nanomaterial applications, including perspective on nanotechnology-based vaccines and therapeutics, and discusses how these tools can be adapted to address new SARS-CoV-2 variants of concern. We also analyze the limitations of current nanomaterial approaches to managing COVID-19 and its variants alongside the challenges posed when implementing this technology. We end by providing avenues for future developments specific to disease modelling in this ever-evolving field.

14.
Silicon ; 14(17):11741-11748, 2022.
Article in English | ProQuest Central | ID: covidwho-2158188

ABSTRACT

Biomedical applications adapt Nano technology-based transistors as a key component in the biosensors for diagnosing life threatening diseases like Covid-19, Acute myocardial infarction (AMI), etc. The proposed work introduces a new biosensor, based on Graphene Field Effect Transistor (GFET), which is used in the diagnosis of Myoglobin (Mb) in human blood. Graphene-based biosensors are faster, more precise, stronger, and more trustworthy. A GFET is created in this study for the detection of myoglobin biomarker at various low concentrations. Because graphene is sensitive to a variety of biomarker materials, it can be employed as a gate material. When constructed Graphene FET is applied to myoglobin antigens, it has a significant response. The detection level for myoglobin is roughly 30 fg/ml, which is quite high. The electrical behavior of the GFET-based biosensor in detecting myoglobin marker is ideal for Lab-on-Chip platforms and Cardiac Point-of-Care Diagnosis.

15.
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities ; 43(10), 2022.
Article in Chinese | Scopus | ID: covidwho-2145038

ABSTRACT

The COVID-19 outbreak caused by SARS-CoV-2 has posed a serious threat to human health. The wide⁃ spread of the virus has increased the demand for anti-virus surface materials,especially in public places. This article reviews a series of inorganic surface materials with antiviral properties,including metals and its derivatives,graphene and its derivatives,and zeolites,and their antiviral mechanisms. The challenges and development prospects are summarized and prospected. © 2022 Higher Education Press. All rights reserved.

16.
ACS Nano ; 16(11): 19451-19463, 2022 Nov 22.
Article in English | MEDLINE | ID: covidwho-2116590

ABSTRACT

The massive production of polymer-based respiratory masks during the COVID-19 pandemic has rekindled the issue of environmental pollution from nonrecyclable plastic waste. To mitigate this problem, conventional filters should be redesigned with improved filtration performance over the entire operational life while also being naturally degradable at the end. Herein, we developed a functional and biodegradable polymeric filter membrane consisting of a polybutylene adipate terephthalate (PBAT) matrix blended with cetyltrimethylammonium bromide (CTAB) and montmorillonite (MMT) clay, whose surface properties have been modified through cation exchange reactions for good miscibility with PBAT in an organic solvent. Particularly, the spontaneous evolution of a partial core-shell structure (i.e., PBAT core encased by CTAB-MMT shell) during the electrospinning process amplified the triboelectric effect as well as the antibacterial/antiviral activity that was not observed in naive PBAT. Unlike the conventional face mask filter that relies on the electrostatic adsorption mechanism, which deteriorates over time and/or due to external environmental factors, the PBAT@CTAB-MMT nanofiber membrane (NFM)-based filter continuously retains electrostatic charges on the surface due to the triboelectric effect of CTAB-MMT. As a result, the PBAT@CTAB-MMT NFM-based filter showed high filtration efficiencies (98.3%, PM0.3) even at a low differential pressure of 40 Pa or less over its lifetime. Altogether, we not only propose an effective and practical solution to improve the performance of filter membranes while minimizing their environmental footprint but also provide valuable insight into the synergetic functionalities of organic-inorganic hybrid materials for applications beyond filter membranes.


Subject(s)
COVID-19 , Nanofibers , Humans , Nanofibers/chemistry , Cetrimonium , Static Electricity , Pandemics , Polymers/chemistry
17.
Silicon ; 14(15):9533-9541, 2022.
Article in English | ProQuest Central | ID: covidwho-2104135

ABSTRACT

In the current scenario, COVID-19 has created a havoc negative impact on the lives of the people, which have triggered the research interest on the design and development of sensitive, low cost and power-efficient sensors for detecting a wide variety of biomolecules. Here, a novel hetero dielectric (HD) hetero material (HM) Bio-RFET based sensor is proposed which works as n or p MOSFET and n or p TFET and hence, is capable to sense the biomolecules through label-free dielectric modulation technique. Without labelling expenses, this biosensor detects a number of biomolecules present in human body as and when kept in a nano cavity. The dielectric polarization within the nanocavity due to the presence of foreign biomolecules under the influence of an electric field causes a variation in drain current. In this paper (SiO2 + TiO2) and AlGaAs/Si based HD-HM-RFET is explored for biosensing applications and mole fraction optimization of AlGaAs is done to obtain better results for four FETs. Work function of 4.5 eV is used in over drain and source electrodes, while metal work function of 4.7 eV  is used for gate electrode. Finally, we found that the proposed device possesses better sensing capability for varying dielectric constant (K = 20 to 80) and charge (−5 × 1011 to 1 × 1013 C/cm2) as compared to a (SiO2 + HfO2)-HM-RFET and Si based (SiO2 + TiO2)-RFET. Further, it is observed that n-(SiO2 + TiO2)-HM-TFET is the best among all FETs and has highest Id-Vgs sensitivity = 5.09 × 1013, ION/IOFF = 1.23 × 109, lowest SS = 20.3 mV/dec and Vth = 1.48 V.

18.
Atmos Pollut Res ; 13(11): 101587, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-2095049

ABSTRACT

To prevent the rapid spreading of the COVID-19 pandemic, the Egyptian government had imposed partial lockdown restrictions which led emissions reduction. This served as ideal conditions for a natural experiment, for study the effect of partial lockdown on the atmospheric aerosol chemistry and the enhanced secondary inorganic aerosol production in a semi-desert climate area like Egypt. To achieve this objective, SO2, NO2, and PM2.5 and their chemical compositions were measured during the pre-COVID, COVID partial lockdown, and post-COVID periods in 2020 in a suburb of Greater Cairo, Egypt. Our results show that the SO2, NO2, PM2.5 and anthropogenic elements concentrations follow the pattern pre-COVID > post-COVID > COVID partial lockdown. SO2 and NO2 reductions were high compared with their secondary products during the COVID partial lockdown compared with pre-COVID. Although, PM2.5, anthropogenic elements, NO2, SO2, SO4 2-, NO3 -, and NH4 + decreased by 39%, 38-55%, 38%, 32.9%. 9%, 14%, and 4.3%, respectively, during the COVID partial lockdown compared with pre-COVID, with the secondary inorganic ions (SO4 2-, NO3 -, and NH4 +) being the dominant components in PM2.5 during the COVID partial lockdown. Moreover, the enhancement of NO3 - and SO4 2- formation during the COVID partial lockdown was high compared with pre-COVID. SO4 2- and NO3 - formation enhancements were significantly positive correlated with PM2.5 concentration. Chemical forms of SO4 2- and NO3 - were identified in PM2.5 based on their NH4 +/SO4 2- molar ratio and correlation between NH4 + and both NO3 - and SO4 2-. The particles during the COVID partial lockdown were more acidic than those in pre-COVID.

19.
Acta Chimica Sinica ; 80(9):1338-1350, 2022.
Article in Chinese | Web of Science | ID: covidwho-2082906

ABSTRACT

The global pandemic of COVID-19 has caused serious harm to people's healthy life and the normal operation of society. People have paid more attention to the prevention and control of microbial contamination such as bacteria and viruses. Blocking the spread of disease-causing microorganisms through indirect contact with humans through contaminated surfaces, or avoiding direct contact with them, is the primary way to protect us from harm. Current solutions include designing antibacterial and antiviral surface coatings and developing personal protective equipment made from self-cleaning films or fabrics. In this paper, the work of several widely studied metals, metal oxides, metal organic framework materials, etc. with antibacterial and antiviral functionality is reviewed, their microbial inactivation mechanisms as well as performance are summarized and discussed. In the end, the future perspectives on emerging research directions and challenges in the development of antibacterial and antiviral coatings and films are presented.

20.
Journal of Chemical Education ; 99(9):3211-3217, 2022.
Article in English | Web of Science | ID: covidwho-2016518

ABSTRACT

We describe a remote pedagogical approach based on chemical thinking to study metal-carbonyl complexes by analyzing simulated IR spectra. The proposed approach, implemented due to the COVID-19 pandemic, can be employed in classrooms that have very limited laboratory equipment for evaluating toxic metal-carbonyl compounds, as well as for synthesizing compounds that have not been reported . The method, consisting of a class lecture accompanied by a remote computational activity , aims to provide students with the ability to assemble concepts from different fields, such as organometallic chemistry and analytical chemistry, while taking advantage of computational methods to answer higher level questions. We evaluated whether analyzing the nature of M-CO bonding was appropriate for achieving these educational goals. Octahedral compounds of the M(CO)(6) and M(CO)(4)L-2 type, bearing a variety of metal centers (M = Cr, Mo, W, V, Mn and Fe) and ligands (L = phosphines and phosphites), as well as bimetallic Fe-2(CO)(9), were compared, showing how these modifications affect M-CO bonding. After the didactic session, attended by second-year and upper-division students of Facultad de Quimica at UNAM, an evaluation and survey showed that students improved their understanding of the subject when they obtained and visualized IR spectra, also exhibiting greater confidence and enthusiasm for addressing challenging topics. The combination of computational results, spectroscopic analysis, and organometallic theory represents an efficient and clear procedure for implementing chemical thinking, regardless of the difficulties posed by the COVID-19 pandemic.

SELECTION OF CITATIONS
SEARCH DETAIL