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1.
Modern Pediatrics ; Ukraine.(4):36-45, 2021.
Article Dans Ukrainien | EMBASE | ID: covidwho-20239394

Résumé

The article presents current data on the prevalence of vitamin D deficiency and criteria for its deficiency in children in different countries. Vitamin D is recognized as one of the most important vitamins involved in many biochemical processes in the body. Its active metabolites play a key role in calcium absorption, bone mineralization and promote phosphate and magnesium metabolism. At the same time, in addition to affecting mineral metabolism, there is a wide range of conditions in which vitamin D also plays a preventive role. Vitamin D has been shown to play a vital role in innate immunity maintenance and is important in prevention of several diseases, including infections, autoimmune diseases, certain forms of cancer, type 1 and 2 diabetes, and cardiovascular diseases. Vitamin D is of particular importance for newborns and young children. This vitamin is involved in important physiological regulatory processes such as bone metabolism, lung development, maturation of the immune system and differentiation of the nervous system. Vitamin D deficiency increases risks of neonatal sepsis, necrotizing enterocolitis, respiratory distress syndrome, and bronchopulmonary dysplasia. Adequate intake of vitamin D and calcium during childhood can reduce the risk of osteoporosis and other diseases associated with vitamin D deficiency in adults. Recently, vitamin D deficiency has shown to be a potential risk factor for COVID-19 propensity. It has been established that to date most scientific pediatric societies have recognized the need to prevent vitamin D deficiency in healthy children of all ages, but data on the dosage of vitamin D in its prophylactic use differ. Most scientific societies recommend an average of 400-600 IU per day of vitamin D for prophylactic purposes. The analysis of published data shows the need to follow a strategy based on an individual approach, taking into account physiological characteristics, individual requirements and lifestyle.Copyright © 2021 University of Tartu Press. All rights reserved.

2.
UCL Open Environ ; 2: e012, 2020.
Article Dans Anglais | MEDLINE | ID: covidwho-20242311

Résumé

In this study, we first point out the possible acoustic problems associated with the post-pandemic operation of built environments. In particular, we focus on the problem of acoustic deficiency due to the lack of absorption. This deficiency, which is likely to be encountered in most enclosed spaces in a range of establishments, is due to the reduced number of audience members or users of the space as a result of social distancing. As one of the promising solutions to this problem, we introduce a sound absorption technique using three-dimensional (3D) space sound absorbers developed through our recent research projects. Significantly, the type of sound absorber proposed herein is made of materials that are especially suited to hygiene considerations. The materials are microperforated panels (MPPs) and permeable membranes (PMs), both of which are easily washable and sanitised. Furthermore, we point out that 3D-MPP or PM space absorbers possess the additional value of aesthetic designability.

3.
UCL Open Environ ; 3: e021, 2021.
Article Dans Anglais | MEDLINE | ID: covidwho-20242310

Résumé

There are various measures currently in place to prevent the spread of coronavirus (COVID-19); however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets, as including a hole-free panel is important to prevent possible droplet penetration. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings on the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. For this study, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study.

4.
Réalités Industrielles ; : 4-6,104, 2023.
Article Dans Français | ProQuest Central | ID: covidwho-2322405

Résumé

L'industrie automobile est a la croisée des chemins, car elle est soumise a une conjonction d'externalités d'une ampleur et d'une intensité rarement vues : absorption de toutes les crises récentes, celles du Covid et des semi-conducteurs, mais aussi celle de la hausse des prix de l'énergie. C'est celui de parvenir å intégrer ces techniques afin de parvenir a réinventer l'automobile de demain, une automobile connectée, robotisée et traitant automatiquement de grands volumes de données afin de progresser en intelligence, et de mettre celle-ci au service de l'humain, pour un usage réinventé de l'automobile et pour instaurer un systéme de mobilité plus durable. Il appelle ainsi a mieux cibler l'accompagnement des fournisseurs pour faire émerger une nouvelle génération d'ETI et aussi l'apparition de grands équipementiers leaders dans le monde de l'électrique, de l'hydrogene et, plus globalement, de l'automobile de demain. Il demande aussi que l'Europe se donne du temps pour s'adapter a la transition en protégeant temporairement, a l'instar des États-Unis, son marché intérieur.

5.
Atmosphere ; 14(4), 2023.
Article Dans Anglais | Scopus | ID: covidwho-2317425

Résumé

With the spread of the COVID-19 pandemic and the implementation of closure measures in 2020, population mobility and human activities have decreased, which has seriously impacted atmospheric quality. Huaibei City is an important coal and chemical production base in East China, which faces increasing environmental problems. The impact of anthropogenic activities on air quality in this area was investigated by comparing the COVID-19 lockdown in 2020 with the normal situation in 2021. Tropospheric NO2, HCHO and SO2 column densities were observed by ground-based multiple axis differential optical absorption spectroscopy (MAX-DOAS). In situ measurements for PM2.5, NO2, SO2 and O3 were also taken. The observation period was divided into four phases, the pre-lockdown period, phase 1 lockdown, phase 2 lockdown and the post-lockdown period. Ground-based MAX-DOAS results showed that tropospheric NO2, HCHO and SO2 column densities increased by 41, 14 and 14%, respectively, during phase 1 in 2021 vs. 2020. In situ results showed that NO2 and SO2 increased by 59 and 11%, respectively, during phase 1 in 2021 vs. 2020, but PM2.5 and O3 decreased by 15 and 17%, respectively. In the phase 2 period, due to the partial lifting of control measures, the concentration of pollutants did not significantly change. The weekly MAX-DOAS results showed that there was no obvious weekend effect of pollutants in the Huaibei area, and NO2, HCHO and SO2 had obvious diurnal variation characteristics. In addition, the relationship between the column densities and wind speed and direction in 2020 and 2021 was studied. The results showed that, in the absence of traffic control in 2021, elevated sources in the Eastern part of the city emitted large amounts of NO2. The observed ratios of HCHO to NO2 suggested that tropospheric ozone production involved NOX-limited scenarios. The correlation analysis between HCHO and different gases showed that HCHO mainly originated from primary emission sources related to SO2. © 2023 by the authors.

6.
Dyes and Pigments ; 216, 2023.
Article Dans Anglais | Scopus | ID: covidwho-2293221

Résumé

Gold (Au) nanoclusters (NCs) are novel materials with low cytotoxicity and high chemical stability. These properties are in high demand during the bioimaging. Moreover, the optical properties of gold clusters allow to use them as colorimetric and luminescent bionanosensors. Pterins are low molecular weight organic compounds, which are used in medicine as biomarkers of phenylketonuria, vitiligo, inflammation and immune system activation, cancer, COVID-19, etc. We have investigated the possibility of gold nanosensors usage to detect pterin (Ptr). Ptr-Aunq structures (n = 1–6;q = 0–2) Gibbs energy of complexation (Eb) have been obtained using density functional theory. The highest Eb was determined for the complexes of Au62+ and Au32+ in acidic and alkaline aqueous solution, respectively. The detection of pterin with gold clusters seems to be prospective using both colorimetric and fluorescent detection because of the intense S0→S1 transition in the absorption spectrum of the Au5+ complex. Raman detection of pterin should be performed at alkaline pH because of the dramatic changes in the spectrum of Ptr−1 upon the addition of Au clusters. We believe that these tunable changes of the pterin spectra due to Au clusters and nanoparticles attachment could be exploited in further studies on nanosensor design. © 2023

7.
Journal of Building Engineering ; 72, 2023.
Article Dans Anglais | Scopus | ID: covidwho-2290595

Résumé

Stepping up the extraction of valuable resources from the oil palm agro-industry was fraught with palm kernel shell (PKS) disposal challenges. One mitigating measure was to recover these materials for use in fired brick production. So PKS and clay materials were characterized for their physical, mineral and thermal properties. These characterizations revealed the high content of SiO2 and Al2O3 in the clay resources and the 95.60% organic content of PKS along with its estimated 21, 774.94 (kJ/kg) higher heating value (HHV). Indexed minerals from X-ray diffraction (XRD) studies of the clay material were kaolinite, quartz, calcite and goethite. Bricks prepared with the inclusion of up to 16 wt% PKS were fired at 900 and 1000 °C. For bricks fired at 1000 °C, bulk densities decreased from 2.07 to 1.54 g/cm3, apparent porosity increased up to 89.14%, water absorption increased from 100% in reference bricks to 203.54% with the addition of 16 wt% PKS. While compressive strengths decreases were in the range of 21.67–6.07 MPa, thermal insulation improved by 22%. Similar trends were established for bricks fired at 900 °C. The analyses showed that PKS addition was more effective in tailoring the technical properties of the bricks than changes in firing temperature. The marginal differences in technical properties of bricks fired at 1000 °C relative to the 900 °C fired brick units were understood from scanning electron microscopy (SEM) studies. Therefore, this research has provided compelling evidences for use of PKS in fired brick production. © 2023 Elsevier Ltd

8.
Atmosphere ; 14(4):612, 2023.
Article Dans Anglais | ProQuest Central | ID: covidwho-2305477

Résumé

Six phthalates: dimethyl phthalate (DMP), diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), butyl benzyl phthalate (BBzP), di(2-ethylhexyl) phthalate (DEHP), and di(n-octyl) phthalate (DOP) in settled dust on different indoor surfaces were measured in 30 university dormitories. A Monte Carlo simulation was used to estimate college students' exposure via inhalation, non-dietary ingestion, and dermal absorption based on measured concentrations. The detection frequencies for targeted phthalates were more than 80% except for DEP (roughly 70%). DEHP was the most prevalent compound in the dust samples, followed by DnBP, DOP, and BBzP. Statistical analysis suggested that phthalate levels were higher in bedside dust than that collected from table surfaces, indicating a nonuniform distribution of dust-phase phthalates in the sleep environment. The simulation showed that the median DMP daily intake was 0.81 μg/kg/day, which was the greatest of the targeted phthalates. For the total exposures to all phthalates, the mean contribution of exposures during the daytime and sleeping time was 54% and 46%, respectively.

9.
Journal of Public Health in Africa ; 14(S1) (no pagination), 2023.
Article Dans Anglais | EMBASE | ID: covidwho-2301010

Résumé

Background: Coronary Heart Disease (CHD), commonly known as the silent killer, impacted the severity of COVID-19 patients during the pandemic era. Thrombosis or blood clots create the buildup of plaque on the coronary artery walls of the heart, which leads to coronary heart disease. Cyclooxygenase 1 (COX-1) is involved in the production of prostacyclin by systemic arteries;hence, inhibiting the COX-1 enzyme can prevent platelet reactivity mediated by prostacyclin. To obtain good health and well-being, the research of discovery of new drugs for anti-thrombotic still continue. Objective(s): This study aims to predict the potential of 17 compounds owned by the vanillin analog to COX-1 receptor using in silico. Method(s): This research employed a molecular docking analysis using Toshiba hardware and AutoDock Tools version 1.5.7, ChemDraw Professional 16.0, Discovery Studio, UCSF Chimera software, SWISSADME and pKCSM, a native ligand from COX-1 (PDB ID: 1CQE) was validated. Result(s): The validation result indicated that the RMSD was <2 A. The 4-formyl-2-methoxyphenyl benzoate compound had the lowest binding energy in COX-1 inhibition with a value of-7.70 A. All vanillin derivatives show good intestinal absorption, and the predicted toxicity indicated that they were non-hepatotoxic. All these compounds have the potential to be effective antithrombotic treatments when consumed orally. Conclusion(s): In comparison to other vanillin derivative com-pounds, 4-formyl-2-methoxyphenyl benzoate has the lowest binding energy value;hence, this analog can continue to be synthesized and its potential as an antithrombotic agent might be confirmed by in vivo studies.Copyright © the Author(s), 2023.

10.
Minerals ; 13(4):505, 2023.
Article Dans Anglais | ProQuest Central | ID: covidwho-2294950

Résumé

Stoneware is a ceramic material with low porosity and high mechanical properties, such as the modulus of rupture. It is essentially made of clay, feldspar and quartz and is sintered to create a mixture of glass and crystalline phases. With the projected growth rate of the global ceramics market size and the country's development plan for 2023–2028, it is imperative that alternative raw materials for the manufacture of ceramic products be sourced so that the importation of these materials, such as feldspar, be minimized, if not eliminated. Cinder in the Philippines is mainly used as a filling material in pavements and residential areas. In this study, this resource is utilized as partial and full replacement of feldspar in a typical ternary diagram for stoneware production. Bars were formed from different formulations by the slip casting method and were sintered at 1200 °C. Physical and mechanical properties of the bars, such as shrinkage, loss on ignition, water absorption, apparent porosity and modulus of rupture were determined. Thermo-physical analyses were also carried out on the raw materials and on formulated powders. Meeting the requirements of the various quality standards for ceramics, the partial replacement of feldspar with black cinder (LF, LFBQ and LFBH) is feasible for wall and roof applications while full replacement of feldspar with black cinder (LB) is suitable for wider use as wall, floor, vitrified, industrial and roof tiles.

11.
Buildings ; 13(4):919, 2023.
Article Dans Anglais | ProQuest Central | ID: covidwho-2294825

Résumé

Plastic waste causes severe environmental impacts worldwide and threatens the lives of all creatures. In the medical field, most of the equipment, especially personal protective equipment (PPE), is made from single-use plastic. During COVID-19, the usage of PPE has increased, and is disposed of in landfills after being used once. Worldwide, millions of tons of waste syringes are generated from COVID-19 vaccination. A practical alternative to utilizing this waste is recycling it to reinforce building materials. This research introduces an approach to using COVID-19 syringe plastic waste to reinforce building material as composite concrete. Reinforced fiber polymer (FRP) concrete materials were used to mold cylindrical specimens, which underwent mechanical tests for mechanical properties. This study used four compositions with 0%, 5%, 10%, and 15% of FRP to create cylindrical samples for optimum results. Sequential mechanical tests were carried out on the created samples. These specimens were cured for a long period to obtain water absorption capability. After several investigations, the highest tensile and compressive strengths, approximately 2.0 MPa and 10.5 MPa, were found for the 5% FRP composition samples. From the curing test, the lowest water absorbability of around 5% was found for the 5% FRP composition samples.

12.
Eur J Pharm Biopharm ; 187: 141-155, 2023 Jun.
Article Dans Anglais | MEDLINE | ID: covidwho-2306002

Résumé

Clofazimine, an anti-leprosy drug, has been anticipated for a candidate to treat tuberculosis, cryptosporidiosis, and coronavirus infection, but its low oral bioavailability is considered a reason for its limited activity. In the current study, we have tried to improve the oral bioavailability of clofazimine by several SNEDDS formulations and characterized the absorption behavior from various aspects. Among four SNEDDS formulations prepared, SNEDDS A, prepared with castor oil as an oil component, provided the highest bioavailability (around 61%) and SNEDDS D, prepared with Capryol 90, gave the second highest bioavailability. SNEDDS A formed the finest nanoparticles, which were maintained under gastric and intestinal luminal conditions. The comparison in oral bioavailability between the SNEDDS formulation and its corresponding preformed nanoemulsion suggested that SNEDDS A would efficiently form nanoemulsion in the gastrointestinal tract after oral administration. AUC of mesenteric lymph node concentration was the highest for SNEDDS A, which would be one of the reasons for SNEDDS A to reveal the highest oral bioavailability. A cycloheximide-treated oral absorption study and single-pass perfusion study by utilizing a vascular-luminal perfused small intestine-liver preparation clearly indicated that over 90% of clofazimine absorbed to systemic circulation should be derived from lymphatic transport for both SNEDDS A and D. Furthermore, the fraction of dose absorbed was around 65% for SNEDDS D, but SNEDDS A achieved around 94%, indicating the excellent performance of SNEDDS A.


Sujets)
Clofazimine , Nanoparticules , Systèmes de délivrance de médicaments , Solubilité , Préparations pharmaceutiques , Administration par voie orale , Biodisponibilité , Nanoparticules/composition chimique , Émulsions/composition chimique , Taille de particule
13.
Pharmacological Research - Modern Chinese Medicine ; 6 (no pagination), 2023.
Article Dans Anglais | EMBASE | ID: covidwho-2275805

Résumé

Introduction: Herbal medicines have been used for the treatment of human disorders and associated secondary complications since a very early age. Herbal medicines are composed with a variety of medicinal plants and their derived products. Coumarin class phytochemicals have an important role in medicine due to its anti-coagulant, anti-cancer, anti-HIV and anti-inflammatory activity. Herbal medicines have been gaining popularity in the modern system of medicine mainly due to its safety and efficacy. Columbianadin is an active phytochemical of Angelica pubescens and Heracleum candolleanum. Columbianadin have analgesic, anti-inflammatory, calcium-channel blocking properties and platelet aggregation inhibitory potential. Method(s): Present work described the medicinal importance and pharmacological activities of columbianadin in medicine supported by their traditional medicinal application and pharmacological activities. Scientific data of columbianadin has been collected from PubMed, Google Scholar, Google, Scopus, and Science Direct. However, scientific data of columbianadin published in Journals, books and scientific report have also been collected in the present paper. Analytical data of columbianadin have also been described to know the significance of analytical techniques for the isolation, and identification of columbianadin. Result(s): Scientific data of columbianadin signified the biological importance and therapeutic potential of columbianadin in medicine. Scientific data of columbianadin revealed their biological potential against inflammation, neuropathic pain, cancer, hepatic complications, and immune system disorders. However, biological effectiveness of columbianadin on blood-brain barrier permeability, body tissue, channels and platelet has also been discussed in the present work. Moreover, its therapeutic effectiveness against nematodes has been also summarized in this work. Analytical data for the isolation and identification of columbianadin in different samples has also been presented in this work. Discussion(s): Present work signified the biological importance and therapeutic potential of columbianadin in medicine, which could be used for the treatment of human disorders and associated secondary complications.Copyright © 2022 The Author(s)

14.
Journal of the Indian Chemical Society ; 100(3) (no pagination), 2023.
Article Dans Anglais | EMBASE | ID: covidwho-2260187

Résumé

We report in silico studies of pyridoxal, which is of interest both as a precursor for further functionalization due to the presence of the aldehyde functionality, as well as a bioactive compound. So far, the crystal structure of pyridoxal has not been reported and, thus, we have optimized its structure both under water solvation and in gas phase using the DFT calculations. Under water solvation conditions the optimized structure of pyridoxal is 7.62 kcal/mol more favorable in comparison to that in gas phase. The DFT calculations were also applied to verify optical and electronic properties of the optimized structure of pyridoxal in water. The HOMO and LUMO were revealed to subtract a set of descriptors of the so-called global chemical reactivity as well as to probe pyridoxal as a potential corrosion inhibitor for some important metals used in implants. The title compound exhibits the best electron charge transfer from the molecule to the surface of Ni and Co. Some biological properties of pyridoxal were evaluated using the respective on-line tools. Molecular docking was additionally applied to study interaction of pyridoxal with some SARS-CoV-2 proteins as well as one of the monkeypox proteins. It was established that the title compound is active against all the applied proteins with the most efficient interaction with nonstructural protein 15 (endoribonuclease) and Omicron Spike protein of SARS-CoV-2. Pyridoxal was found to be also active against the studied monkeypox protein. Interaction of pyridoxal with nonstructural protein 15 (endoribonuclease) was further studied using molecular dynamics simulation.Copyright © 2023 Indian Chemical Society

15.
Building Acoustics ; 2023.
Article Dans Anglais | Scopus | ID: covidwho-2258935

Résumé

In open-plan offices (OPO), workspaces without ground-to-ceiling dividers, noise is one of the most complained about aspects, causing physical and psychological impacts. With the increasing interest for a human-centric design, notably after the publication of ISO 22955, this review aims to identify the main noise sources in this office layout and the employees' perception of related health effects, evaluating the interventions proposed to overcome their impacts. Following the PRISMA guidelines, a review was conducted using the Scopus and PubMed databases, considering subjective questionnaires distributed in offices, which could include physical workspace assessment. It excluded studies limited to: (a) laboratory experiments;(b) isolated cognitive tests;(c) office layouts other than OPO;(d) systematic reviews;and (e) mathematical models. Sixty studies were identified and the screening process resulted in 11 selected for inclusion, which indicated irrelevant speech, chatting, and telephone ringing as the main noise sources causing productivity loss, stress, and low comfort rates due to distraction and lack of privacy. To overcome these impacts, researchers suggested the use of sound-absorbing surfaces, separated zones for different tasks and headphones, although their effectiveness relies on human behaviour and economic feasibility. Thus, the evidence indicates that noise is a recurrent issue in OPOs, it demonstrates the importance of appropriate acoustic performance of the workspace and the necessity of new studies regarding OPO workers' perception of noise and their health, particularly after the COVID-19 new safety guidelines. © The Author(s) 2023.

16.
Journal of Molecular Structure ; 1282, 2023.
Article Dans Anglais | Scopus | ID: covidwho-2258419

Résumé

Oxadiazines are heterocyclic compounds containing two nitrogen and one oxygen atom in a six-membered ring. The synthesis and crystal structure of 4-(4-methoxyphenyl)-6-methyl-3-phenyl-4H-1,2,4-oxadiazin-5(6H)-one (MPMP-OXA) was reported. The organic crystal structure of the synthesized compound was fully characterized by various spectroscopic techniques (Fourier Transform Infrared Spectroscopy, NMR and LC/MS-TOF) and single-crystal X-ray diffraction studies. The MPMP-OXA crystal structure crystallizes in the triclinic system and space group P-1 with a = 5.9395(15) Å, b = 11.471(3) Å, c = 11.901(3) Å, α = 70.075(4)°, β = 83.454(4)°, γ = 78.016(4)°, V = 744.9(3) Å3, Z = 2 cell parameters. This work is aimed to study the weak interactions in the crystal packing of a new synthesized oxadiazine derivate. The contributions of the most important intermolecular interactions in the crystal structure were investigated by 3D-Hirshfeld surface (HS) and 2D-fingerprint analysis. The C[sbnd]H···O interactions as the most important contributors to the crystal packing between the oxygen of the oxadiazine ring and the hydrogen atom of phenyl ring appear as bright red spots visible on the HS surface. The hydrogen-bonded interaction of MPMP-OXA has been investigated using noncovalent interactions approach. The molecular docking studies for the synthesized compound were performed to gain insight into the inhibition nature of this molecule against DNA Gyrase B Candida and 3-chymotrypsin-like protease (SARS-CoV main protease) proteins and resulted in good activities for new anti-agents. Lastly, Bioavailability, druggability as well as absorption, distribution, metabolism, excretion, and toxicity parameters (ADMET), and gastrointestinal absorption (BOILED-Egg method) properties of newly synthesized compound using smile codes were performed in detail. © 2023 Elsevier B.V.

17.
Education Sciences ; 13(3), 2023.
Article Dans Anglais | Scopus | ID: covidwho-2253839

Résumé

Spectroscopy is the basis of many applications in chemistry;however, the basic principles of light, light–matter interaction, and the operation of spectrophotometers are rarely present in chemistry curricula at the high-school level, or they are only briefly introduced to students before focusing on analytical chemistry applications. In this work, we report the results of a study conducted over several years, aimed to design, optimise, and put into practice a didactic sequence on light phenomena such as reflection, refraction, interference, diffraction, and light dispersion, as well as the basic principles of ultraviolet–visible spectroscopy and spectroscopic instruments. Difficult concepts of light phenomena and related topics were deeply investigated, focusing on the best ways to teach them to high-school students in the framework of the content-specific components identified in the topic-specific pedagogical content knowledge theoretical model. Inquiry-based learning and interactive STEM laboratory activities were combined with a historical epistemological teaching method. Short introductory videos were also recorded to help students during the remote lessons in the COVID-19 pandemic period. In this paper, we report and discuss the research strategy used in order to design and implement the sequence of educational activities, leading to a final optimised didactic sequence that was tested in a pilot study. The main results were obtained from the experimentation with several classes in two high-school technical institutes with a chemistry and material sciences curriculum, along with a group of undergraduate students during the first part of an introductory course on molecular spectroscopy. © 2023 by the authors.

18.
30th Annual International eTourism Conference, ENTER 2023 ; : 40-52, 2023.
Article Dans Anglais | Scopus | ID: covidwho-2288928

Résumé

The extant studies have attested to the effects of media experiences in shaping destination image and influencing the behavioral intentions of potential tourists. However, limited works have focused on the impact of holistic experiences during the interaction with destination-related short-form videos on potential tourists' negative emotional responses and post-COVID travel intention. This study aims to elucidate how cognitive absorption affects tourists' travel anxiety and post-pandemic travel intention in different travel settings (domestic versus international). The comparative results show that users' cognitive absorption when interacting with destination-related short-form videos can effectively influence the behavioral intentions of potential tourists. The result also identified that travel anxiety significantly contributes to higher post-COVID travel intention. This study expands cognitive absorption research in the contexts of tourism and short-form videos, offers an angle for future studies to positively interpret tourists' travel anxiety, and provides tourism practitioners with suggestions on the tourism industry's recovery in the post-COVID era. © 2023, The Author(s).

19.
Coronaviruses ; 3(2):70-79, 2022.
Article Dans Anglais | EMBASE | ID: covidwho-2284126

Résumé

Background: The recent reemergence of the coronavirus (COVID-19) caused by the virus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has prompted the search for effective treatments in the forms of drugs and vaccines. Aim(s): In this regard, we performed an in silico study on 39 active antidiabetic compounds of medicinal plants to provide insight into their possible inhibitory potentials against SARS-CoV-2 replications and post-translational modifications. Top 12 active antidiabetic compounds with potential for dual inhibition of the replications and post-translational modifications of SARS-CoV-2 were ana-lyzed. Result(s): Boswellic acids, celastrol, rutin, sanguinarine, silymarin, and withanolides expressed binding energy for 3-chymotrypsin-like protease (3CLpro) (-8.0 to-8.9 Kcal/mol), papain-like protease (PLpro) (-9.1 to-10.2 Kcal/mol), and RNA-dependent RNA polymerase (RdRp) (-8.5 to-9.1 Kcal/-mol) which were higher than the reference drugs (Lopinavir and Remdesivir) used in this study. Sanguinarine, silymarin, and withanolides are the most druggable phytochemicals among other phy-tochemicals as they follow Lipinski's rule of five analyses. Sanguinarine, silymarin, and withano-lides expressed moderate solubility with no hepatotoxicity, while silymarin and withanolides could not permeate the blood-brain barrier and showed no Salmonella typhimurium reverse mutation as-say (AMES) toxicity, unlike sanguinarine from the predictive absorption, distribution, metabolism, elimination, and toxicity (ADMET) studies. Conclusion(s): Sanguinarine, silymarin, and withanolides could be proposed for further experimental studies for their development as possible phytotherapy for the COVID-19 pandemic.Copyright © 2022 Bentham Science Publishers.

20.
Nanomaterials (Basel) ; 13(5)2023 Mar 05.
Article Dans Anglais | MEDLINE | ID: covidwho-2272509

Résumé

The low solubility and slow dissolution of hydrophobic drugs is a major challenge for the pharmaceutical industry. In this paper, we present the synthesis of surface-functionalized poly(lactic-co-glycolic acid) (PLGA) nanoparticles for incorporation into corticosteroid dexamethasone to improve its in vitro dissolution profile. The PLGA crystals were mixed with a strong acid mixture, and their microwave-assisted reaction led to a high degree of oxidation. The resulting nanostructured, functionalized PLGA (nfPLGA), was quite water-dispersible compared to the original PLGA, which was non-dispersible. SEM-EDS analysis showed 53% surface oxygen concentration in the nfPLGA compared to the original PLGA, which had only 25%. The nfPLGA was incorporated into dexamethasone (DXM) crystals via antisolvent precipitation. Based on SEM, RAMAN, XRD, TGA and DSC measurements, the nfPLGA-incorporated composites retained their original crystal structures and polymorphs. The solubility of DXM after nfPLGA incorporation (DXM-nfPLGA) increased from 6.21 mg/L to as high as 87.1 mg/L and formed a relatively stable suspension with a zeta potential of -44.3 mV. Octanol-water partitioning also showed a similar trend as the logP reduced from 1.96 for pure DXM to 0.24 for DXM-nfPLGA. In vitro dissolution testing showed 14.0 times higher aqueous dissolution of DXM-nfPLGA compared to pure DXM. The time for 50% (T50) and 80% (T80) of gastro medium dissolution decreased significantly for the nfPLGA composites; T50 reduced from 57.0 to 18.0 min and T80 reduced from unachievable to 35.0 min. Overall, the PLGA, which is an FDA-approved, bioabsorbable polymer, can be used to enhance the dissolution of hydrophobic pharmaceuticals and this can lead to higher efficacy and lower required dosage.

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