Realization of Coronavirus Testing Kit Using a Combination of a Triangular Photonic Crystal (PhC) Structure and a 412 nm Laser Beam

The design of a Covid-19 testing kit is proposed in this research using a photonic crystal structure (PhC) and a violet laser beam. The basic principle of this structure relies on the phenomenon of absorbance reflectance and transmission at the signal of a 412 nm laser beam. Finally, the transmitted light energy through the PhC structure is the conclusive factor to detect the types of virus which is the function of the reflectance and absorbance. The reflected light energy is computed by plane wave expansion (PWE) whereas the absorbance of light energy is obtained through numerical computation. The notable advantages of this technique are that the virus related to Covid-19 can be recognized by observing the colour of transmitted energy through a photo energy meter. Finally, the outcomes of the research affirm that the sample could be Covid-19 if the output energy would be infrared (IR). Similarly, the sample could be a normal coronavirus, if the output energy would lie within the visible regime.

Synthesis of Biologically Active α-Tetralone Condensate: Growth of Single Crystal, Characterization by Experimental and Simulation Methods

The exocyclic double bonded α-tetralone condensate viz. (2E)-2-(4-propoxybenzylidene)-3,4-dihydro-1(2H)-naphthalene-1-one was synthesized by the Claisen–Schmidt reaction between α-Tetralone and 4-propoxybenzaldehyde in an alkaline medium. A slow evaporation technique was used to collect the single crystals. Researchers examined the detailed information provided by spectral studies. The inter- and intra-molecular interactions of the compound were identified using the single-crystal XRD investigation. Charge transfer inside organic molecules was used to calculate HOMO and LUMO energy values. In addition, MEP, NBO, NLO, topological charge distribution, and Mulliken population studies were performed for this compound. The Hirschfeld surface study showed that nonpolar or weakly polar interactions significantly contributed to the packing forces for molecules. Then, it was tested for its antioxidant, antidiabetic, and anti-inflammatory properties. The 6yb7 protein and the (2E)-2-(4-propoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one (PBDN) ligand were docked in molecular docking research.Crystal growth and spectral studies have been performed on (2E)-2-(4-propoxybenzylidene)-3,4-dihydro-2H-naphthalen-1-one (PBDN).Simulation studies were discussed.The compound PBDN has potential anti-inflammatory and anti-diabetic properties. In-silico method reveals that the PBDN is a moderate ligand for an unliganded active site on COVID-19's main protease (PDB code: 6yb7). [ FROM AUTHOR] Copyright of Polycyclic Aromatic Compounds is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

A phenoxy-bridged trinuclear Ni(ii) complex: synthesis, structural elucidation and molecular docking with viral proteins

A novel phenoxy-bridged trinuclear nickel(ii) complex [Ni3(mu-L)2(bipy)3](1) (where H3L= (E)-2-hydroxy-N-(2-hydroxy-3,5-diiodophenyl)-3,5-diiodobenzohydrazonic acid, bipy = 2,2'-bipyridyl) has been designed and synthesized as a potential antivirus drug candidate. The trinuclear Ni(ii) complex [Ni3(mu-L)2(bipy)3](1) was fully characterized via single crystal X-ray crystallography. The unique structure of the trinuclear nickel(ii) complex crystallized in a trigonal crystal system with P3221 space group and revealed distorted octahedral coordination geometry around each Ni(ii) ion. The X-ray diffraction analysis established the existence of a new kind of trinuclear metal system containing nickel(ii)-nickel(ii) interactions with an overall octahedral-like geometry about the nickel(ii) atoms. The non-bonded Ni-Ni distance seems to be 3.067 and 4.455 A from the nearest nickel atoms. The detailed structural analysis and non-covalent supramolecular interactions are also investigated by single crystal structure analysis and computational approaches. Hirshfeld surfaces (HSs) and 2D fingerprint plots (FPs) have been explored in the crystal structure to investigate the intermolecular interactions. The preliminary analysis of redox and magnetic characterization was conducted using cyclic voltammetry measurements and a vibrating sample magnetometer (VSM), respectively. This unique structure shows good inhibition performance for SARS-CoV-2, Omicron and HIV viruses. For insight into the potential application of the Ni(ii) coordination complex as an effective antivirus drug, we have examined the molecular docking of the trinuclear Ni(ii) complex [Ni3(mu-L)2(bipy)3](1) with the receptor binding domain (RBD) from SARS-CoV-2 (PDB ID: 7MZF), Omicron BA.3 variant spike (PDB ID: 7XIZ), and HIV protease (PDB ID: 7WCQ) viruses. This structure shows good inhibition performance for SARS-CoV-2, Omicron S protein and HIV protease viruses;the binding energies (DELTAG) and the respective Ki/Kd (inhibition/dissociation constants) correlation values are -8.9 (2.373 muM or 2373 nM), -8.1 (1.218 muM or 1218 nM) and -7.9 (0.874 muM or 874 nM), respectively. The results could be used for rational drug design against SARS-CoV-2 Omicron variant and HIV protease viruses.Copyright © 2023 The Royal Society of Chemistry.

COVID-19 OUTCOMES IN KOREAN PATIENTS WITH GOUT

BackgroundPatients with autoimmune inflammatory rheumatic diseases are at higher risk for coronavirus disease (COVID)-19 hospitalization and worse clinical outcomes compared with the general population. However, data on the association between COVID-19 outcomes and gout, or gout-related medications are still lacking.ObjectivesWe aimed to compare COVID-19 related clinical outcomes in gout vs. non-gout patients.MethodsWe conducted a retrospective cohort study using the electronic health record-based databases of Seoul National University hospital (SNUH) from January 2021 to April 2022 mapped to a common data model. Patients with gout and without gout were matched using a large-scale propensity score (PS) algorithm. The clinical outcomes of interest were COVID-19 infection, severe COVID-19 outcomes defined as the use of mechanical ventilation, tracheostomy or extracorporeal membrane oxygenation, and death within 30 days of COVID-19 diagnosis. The hazard ratio (HR) for gout vs. non-gout patients derived by Cox proportional hazard models were estimated utilizing a 1:5 PS-matched cohort.Results2,683 patients with gout and 417,035 patients without gout were identified among the patients who visited SNUH. After 1:5 PS matching, 1,363 gout patients and 4,030 non-gout patients remained for the analysis. The risk of COVID-19 infection was not significantly different between patients with gout and those without gout (HR 1.07 [95% CI 0.59-1.84]). Within the first month after the COVID-19 diagnosis, there was also no significant difference in the risk of hospitalization (HR 0.57 [95% CI 0.03-3.90], severe COVID-19 outcomes (HR 2.90 [95% CI 0.54-13.71]), or death (HR 1.35 [95% CI 0.06-16.24]).ConclusionPatients with gout did not have an increased risk of COVID-19 infection or worse clinical outcomes. Updates of temporal trends of COVID-19 outcomes in gout patients are yet warranted as new SARS-CoV-2 variants emerge.References[1]Shin YH, et al. Autoimmune inflammatory rheumatic diseases and COVID-19 outcomes in South Korea: a nationwide cohort study. Lancet Rheumatol. 2021 Oct;3(10):e698-e706.[2]Topless RK, et al. Gout and the risk of COVID-19 diagnosis and death in the UK Biobank: a population-based study. Lancet Rheumatol. 2022 Apr;4(4):e274-e281.[3]Xie D, et al. Gout and Excess Risk of Severe SARS-CoV-2 Infection Among Vaccinated Individuals: A General Population Study. Arthritis Rheumatol.2023 Jan;75(1):122-132.Table 1.Clinical outcomes of COVID-19 infection in patients with goutOutcomesUnmatched populationPopulation with PS stratification using 10 strata1:5 PS matched populationHazard ratio (95% CI)p-valueHazard ratio (95% CI)p-valueHazard ratio (95% CI)p-valueCOVID-19 infection1.68 (1.03-2.57)0.031.20 (0.72-1.87)0.461.07 (0.59-1.84)0.82Hospitalization due to COVID-191.92 (0.32-6.05)0.391.63 (0.26-5.77)0.540.57 (0.03-3.90)0.66Severe COVID-19 infection4.72 (1.44-11.28)<0.014.22 (1.17-12.21)0.022.90 (0.54-13.71)0.20Death due to COVID-191.15 (0.07-5.18)0.900.77 (0.04-3.81)0.821.35 (0.06-16.24)0.84Acknowledgements:NIL.Disclosure of InterestsNone Declared.

A selectivity-enhanced colloidal crystal array for ribavirin sensing based on the synergistic effect of covalent and non-covalent interactions

Ribavirin is an important antiviral with demonstrated activity against coronaviruses such as severe acute respiratory syndrome coronavirus and coronavirus disease 2019 virus. However, abuse of ribavirin will cause great environmental damage and threaten human health owing to its reproductive toxicity and teratogenicity. Therefore, an innovative detection method is demanded for simple and sensitive detection of ribavirin. This work reports an imprinted colloidal crystal array (ICCA) for ribavirin sensing. The building blocks of the ICCA are ribavirin imprinted spheres, which possess superior binding efficiency toward ribavirin. Benefiting from the highly ordered structure, the ICCA exhibits optical properties which change upon binding ribavirin. The changes in reflectance wavelength enable a fast and label-free detection of ribavirin between 21 and 245 μmol L−1. Moreover, the sensor shows excellent selectivity for ribavirin detection in river water. Overall, all the results reported in this work demonstrate that the ICCA should be a promising detection tool for antivirals. © 2023 Society of Industrial Chemistry. © 2023 Society of Industrial Chemistry.

Structure-Based Design of Potent Peptidomimetic Inhibitors Covalently Targeting SARS-CoV-2 Papain-like Protease.

The papain-like protease (PLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a critical role in the proteolytic processing of viral polyproteins and the dysregulation of the host immune response, providing a promising therapeutic target. Here, we report the structure-guide design of novel peptidomimetic inhibitors covalently targeting SARS-CoV-2 PLpro. The resulting inhibitors demonstrate submicromolar potency in the enzymatic assay (IC50 = 0.23 µM) and significant inhibition of SARS-CoV-2 PLpro in the HEK293T cells using a cell-based protease assay (EC50 = 3.61 µM). Moreover, an X-ray crystal structure of SARS-CoV-2 PLpro in complex with compound 2 confirms the covalent binding of the inhibitor to the catalytic residue cysteine 111 (C111) and emphasizes the importance of interactions with tyrosine 268 (Y268). Together, our findings reveal a new scaffold of SARS-CoV-2 PLpro inhibitors and provide an attractive starting point for further optimization.

Development of Nanopackaging for Storage and Transport of Loaded Lipid Nanoparticles.

Easily deploying new vaccines globally to combat disease outbreaks has been highlighted as a major necessity by the World Health Organization. RNA-based vaccines using lipid nanoparticles (LNPs) as a drug delivery system were employed to great effect during the recent COVID-19 pandemic. However, LNPs are still unstable at room temperature and agglomerate over time during storage, rendering them ineffective for intracellular delivery. We demonstrate the suitability of nanohole arrays (nanopackaging) as patterned surfaces to separate and store functionalized LNPs (fLNPs) in individual recesses, which can be expanded to other therapeutics. Encapsulating calcein as a model drug, we show through confocal microscopy the effective loading of fLNPs into our nanopackaging for both wet and dry systems. We prove quantifiably pH-mediated capture and subsequent unloading of over 30% of the fLNPs using QCM-D on alumina surfaces altering the pH from 5.5 to 7, displaying controllable storage at the nanoscale.

Self-Destructive Structural Color Liquids for Time-Temperature Indicating.

Vaccines are undoubtedly a powerful weapon in our fight against global pandemics, as demonstrated in the recent COVID-19 case, yet they often face significant challenges in reliable cold chain transport. Despite extensive efforts to monitor their time-temperature history, current time-temperature indicators (TTIs) suffer from limited reliability and stability, such as difficulty in avoiding human intervention, inapplicable to subzero temperatures, narrow tracking temperature ranges, or susceptibility to photobleaching. Herein, we develop a class of structural color materials that harnesses dual merits of fluidic nature and structural color, enabling thermal-triggered visible color destruction based on triggering agent-diffusion-induced irreversible disassembly of liquid colloidal photonic crystals for indicating the time-temperature history of the cold chain transport. These self-destructive structural color liquids (SCLs) exhibit inherent irreversibility, superior sensitivity, tunable self-destructive time (minutes to days), and a wide tracking temperature range (-70 to +37 °C). Such self-destructive SCLs can be conveniently packaged into flexible TTIs for monitoring the storage and exposure status of diverse vaccines via naked-eye inspection or mobile phone scanning. By overcoming the shortcomings inherent in conventional TTIs and responsive photonic crystals, these self-destructive SCLs can increase their compatibility with cold chain transport and hold promise for the development and application of the next-generation intelligent TTIs and photonic crystals.

Novel oxazolidinone zinc(II) complexes as antibacterial and anti-SARS-CoV-2 agents: synthesis, characterization, DFT calculations, ADMET, in silico molecular docking and biological activities

A series of Zn(II) complexes with oxazolidinone derivatives has been synthesized and characterized using spectroscopic techniques: IR, H-1 NMR, UV-Vis spectroscopy, and TGA/DTG thermal investigation. Theoretical computations were carried out using B3LYP/6-31G(d) and B3LYP/LanL2DZ to analyze the vibrational properties, NBO charges, global chemical reactivity indices and to illustrate the FOMs. TD-DFT calculations using WB97XD functional were realized with 6-31 G(d) and LAN2DZ basis set on oxazolidinone ligands and their zinc complexes. The pharmacokinetic properties and toxicity of the investigated compounds were predicted using in silico ADMET studies. Moreover, the S. aureus, E. coli, S. pneumoniae, ribosome 50S subunit, SARS-Cov-2 spike protein and ACE2 human receptor were selected for molecular docking study. The docking study shows that HL4 and ZnL4 bind better to the spike protein and hACE2 receptor. The redox properties were also studied for ligands and their corresponding complexes using cyclic voltammetry. Finally, antioxidant activity studies using DPPH radical scavenging showed efficiency for HL2 and [Zn(L-2)(2)] with low values of IC50 compared to ascorbic acid. The antimicrobial activity against B. subtilis (ATCC 9372), E. faecalis (ATCC 29212), S. aureus (ATCC 6538), E. coli (ATCC 4157), bacteria strains, C. albicans (ATCC 24433) and A. niger fungi strains were evaluated.

An Audit Showing the Successful Operation of a Nurse-Led Gout Clinic during the Covid-19 Pandemic

Background/Aims Research has shown nurse-led gout clinics provide better outcomes compared to usual care. This District General Hospital set up a pilot nurse-led gout clinic in autumn 2019. This aimed to improve patients' understanding of their condition, achieve better control of serum uric acid levels (SUA), reduce flares and prevent Emergency Department attendances. Methods A modified clinic protocol, closely modelled on BSR guidance was agreed within the department. With consultant supervision, one nurse specialist provided a mix of in-person and telephone appointments. Targets were set aiming for SUA <360mumol/L for most patients and <300mumol/L for those with erosive change or tophi. All patients were offered prophylaxis. Patients required a rheumatologist's diagnosis of gout or crystal confirmation for enrolment. Exclusion criteria were significant renal or hepatic derangement. Within 3 months of the service starting SARS-CoV-2 impacted the operation of healthcare worldwide and led to the closure of routine outpatient clinics in Northern Ireland. A decision was made to switch the gout clinic to run entirely by telephone. Blood testing was facilitated through primary care and phlebotomy hubs. Results Over a 19-month period, 78 patients were treated and audited through this clinic: 69 men and 9 women. Average age was 57, mean SUA 509 mumol/L at referral and 322 mumol/L on discharge. 69 patients received allopurinol and 9 received febuxostat. No patients required uricosuric drugs. All patients were offered and agreed to take prophylaxis with a majority (85.8%) remaining on it for 3-6 months. Patients required a mean of 3.38 appointments prior to discharge from the clinic. The mean dose of urate lowering therapy on discharge was 315.9mg allopurinol and 93.3mg febuxostat. 95% experienced >=2 flares during their enrolment in the clinic with no patients requiring Emergency Department attendance due to gout flare. Conclusion The nurse-led gout clinic was well received by patients and was effective as a telephone service during the pandemic when so many services were stood down. The clinic was able to continue to provide education, deliver effective reductions in uric acid as well as reduce incidence of flares and Emergency Department attendances. Lower doses of urate lowering therapy than expected were needed to achieve target. A small number of patients were discharged prior to enrolment for initial non-engagement which may have been exacerbated by the lack of face-to-face appointments. Our COVID-19 model did struggle with those patients needing an interpreter. In-person initial appointments have since been restarted;however, a greater proportion of reviews will continue to be offered by telephone given the unexpected success of the model. This audit showed that a nurse-led gout clinic can run successfully, even during a pandemic with a significant reliance on telephone consultations.

Synthesis, theoretical calculations, X-ray, HS and energy framework analysis, molecular docking of amino pyrazole containing azo dye and its inhibition activity of COVID-19 main protease

The synthesis and characterization of 5-Amino-4-Phenylazo-3-Methyl-1-(2-hydroxyethyl) Pyrazole (AD2a) were investigated in our study. The novel synthesized pyrazole-based disperse diazo dye has been elucidated by using UV–Vis, FT-IR, elemental analysis, LC/MS-MS, NMR and X-ray analysis. The AD2a molecule containing pyrazole and phenyl rings, hydroxy‑ethyl and azo group moieties crystallized in the orthorhombic space group Pbca. The crystal structures of AD2a are consolidated by N(3)-H(3A)⋯O(1) and O(1)-H(1)⋯N(5) intermolecular hydrogen bonds. The geometry of AD2a has been optimized with the DFT calculation B3LYP/6–31G(d,p) level and it has been observed that the obtained results give very good results with the X-ray diffraction data. The theoretical vibrational analysis, frontier orbital energies, electronic absorption spectrum, electronic properties, global reactivity descriptors and other theoretical parameters were obtained by using the same DFT method. Additionally, Hirshfeld surface analysis (HSA) with 2D fingerprint plots (FP) was performed to estimate contacts and the energy framework diagrams of AD2a (Eele, Edis and Etot) were determined. The inhibitor-receptor relationship established by the molecular docking study confirmed the inhibition activity of the AD2a construct against COVID-19. It showed that the AD2a molecule, shown as a drug candidate, binds strongly to SARS-CoV-2 (Mpro) (-6.5 kcal/mol) receptors.

HiBGT: High-Performance Bayesian Group Testing for COVID-19

The COVID-19 pandemic has necessitated disease surveillance using group testing. Novel Bayesian methods using lattice models were proposed, which offer substantial improvements in group testing efficiency by precisely quantifying uncertainty in diagnoses, acknowledging varying individual risk and dilution effects, and guiding optimally convergent sequential pooled test selections. Computationally, however, Bayesian group testing poses considerable challenges as computational complexity grows exponentially with sample size. HPC and big data stacks are needed for assessing computational and statistical performance across fluctuating prevalence levels at large scales. Here, we study how to design and optimize critical computational components of Bayesian group testing, including lattice model representation, test selection algorithms, and statistical analysis schemes, under the context of parallel computing. To realize this, we propose a high-performance Bayesian group testing framework named HiBGT, based on Apache Spark, which systematically explores the design space of Bayesian group testing and provides comprehensive heuristics on how to achieve high-performance, highly scalable Bayesian group testing. We show that HiBGT can perform large-scale test selections (> 250 state iterations) and accelerate statistical analyzes up to 15.9x (up to 363x with little trade-offs) through a varied selection of sophisticated parallel computing techniques while achieving near linear scalability using up to 924 CPU cores. © 2022 IEEE.

British Society for Rheumatology Annual Conference 2023 Abstracts

The proceedings contain 343 papers. The topics discussed include: implementation of a disease modifying anti-rheumatic drug blood monitoring software: 8 years of experience in a single center;effectiveness of colchicine among patients with COVID-19 infection: a randomized, open labelled, clinical trial;rheumatic autoimmune diseases following COVID-19 infection: an observational study in Iraqi Kurdistan region;COVID-19 in male elite Irish-based athletes at a national sports institute;the effects of a pain management program for patients with an inflammatory arthritis;a retrospective analysis of the effectiveness safety of platelet rich plasma injections in primary osteoarthritis in knee joint, in patients attending a tertiary care hospital, Sri Lanka;a cohort study;do proformas used in fracture liaison service appointments reflect national osteoporosis clinical standards? a content analysis;calcium pyrophosphate dihydrate crystal in operated rheumatoid arthritis of the knee;cardiac amyloidosis: a case series of 31 patients with a comprehensive literature review;scoping review for the application of center of pressure for patient or intervention assessment in rheumatoid conditions;and four SNPs associated with monocyte/macrophage cell lineage uniquely associated with CRPS-1 in discovery and replication cohorts and suggest predisposition to regional osteopenia and digit misperception.

The Role of Structural Biology Task Force: Validation of the Binding Mode of Repurposed Drugs Against SARS-CoV-2 Protein Targets: Focus on SARS-CoV-2 Main Protease (Mpro): A Promising Target for COVID-19 Treatment

The main protease (Mpro) of SARS-CoV-2, a cysteine protease that plays a key role in generating the active proteins essential for coronavirus replication, is a validated drug target for treating COVID-19. The structure of Mpro has been elucidated by macromolecular crystallography, but owing to its conformational flexibility, finding effective inhibitory ligands was challenging. Screening libraries of ligands as part of EXaSCale smArt pLatform Against paThogEns (ExScalate4CoV) yielded several potential drug molecules that inhibit SARS-CoV-2 replication in vitro. We solved the crystal structures of Mpro in complex with repurposed drugs like myricetin, a natural flavonoid, and MG-132, a synthetic peptide aldehyde. We found that both inhibitors covalently bind the catalytic cysteine. Notably, myricetin has an unexpected binding mode, showing an inverted orientation with respect to that of the flavonoid baicalein. Moreover, the crystallographic model validates the docking pose suggested by molecular dynamics experiments. The mechanism of MG-132 activity against SARS-CoV-2 Mpro was elucidated by comparison of apo and inhibitor-bound crystals, showing that regardless of the redox state of the environment and the crystalline symmetry, this inhibitor binds covalently to Cys145 with a well-preserved binding pose that extends along the whole substrate binding site. MG-132 also fits well into the catalytic pocket of human cathepsin L, as shown by computational docking, suggesting that it might represent a good start to developing dual-targeting drugs against COVID-19. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Synthesis, structural analysis, DFT and molecular docking studies of N-(6-(((E)-4-methoxybenzylidene)amino)hexyl)-1-(4-methoxyphenyl) methanimine and its hydrate as a possible 2019-nCoV protease inhibitor

N-(6-(((E)-4-methoxybenzylidene) amino) hexyl)-1-(4-methoxyphenyl) methanimine (1) and its hydrate (2) were synthesized by refluxing hexamethylene diamine and anisaldehyde in presence of catalytic amount of H-Beta zeolite in solvent methanol. Resulting imines were characterized by spectroscopic analysis augmented by Single crystal X-ray diffraction. Both compounds crystalize in monoclinic crystal systems with different point groups P 21 and C 2/c. Pair wise aromatic π-CH and CH- π interactions with distance 2.887 and 2.786 Ao and iminic CH- π interactions with the distance of 2.73 Ao are mainly responsible for extending the structure along 3 dimensions. However, hydrated structure exhibited an addition hydrogen bonding with H of water molecules with the distance of 2.030 Ao , also methoxy O is involved in hydrogen bonding interaction with CH with the distance of 2.641 Ao. Probable contact points and most important crystal packing contributions were determined by employing Hirshfeld surface analysis. H…H and C…H contacts are the most important contributors in the Hirshfeld Surface. Electronic and structural characteristics of both compounds has been calculated using B3LYP/6-311G (d,p) theory. In addition, FMO and MEPS analyses were also accomplished for optimized structures. Molecular Docking studies of compound 1 and 2 were carried out with protease enzyme of 2019-nCoV (PDB-ID 7BRO), monohydrate(2) was involved in more favourable interactions hence accounting for greater binding energy (-7.98 kcal/mol) and inhibition constant (12.96 mM) than compound 1 exhibiting inhibition constant of 39.25 mM and binding energy of -6.23 kcal/mol.

In Situ Electrochemical Trapping and Unraveling the Mechanism of the Toxic Intermediate Metabolite N-Acetyl-p-Benzoquinone Imine of the Acetaminophen Drug and Its Biomimetic Mediated NADH Oxidation Reaction

The integrative study of the pharmacokinetics and dynamics of a drug has been of great research interest due to its authentic description of the biomedical and clinical pros and cons. Acetaminophen (N-acetyl-4-aminophenol, AcAP) is a well-known analgesic having a high therapeutic value, including the Covid-19 treatment. However, an overdose of the drug (>200 mg/kg of men) can lead to liver toxicity. An intermediate, N-acetyl-p-benzoquinone imine (NAPQI), metabolite formation has been found to be responsible for the toxicity. For the detection of NAPQI, several ex situ techniques based on electrochemical methods followed by nuclear magnetic resonance, high-performance liquid chromatography, and LC-MS were stated. For the first time, we report an in situ electrochemical approach for AcAP oxidation and NAPQI intermediate (Mw = 149.1 g mol-1) trapping on a graphitic nanomaterial, carbon black (CB)-modified electrode in pH 7 phosphate buffer solution (CB@NAPQI). The NAPQI-trapped electrode exhibited a surface-confined redox peak at E°′ = 0.350 ± 0.05 V vs Ag/AgCl with a surface excess value of 3.52 n mol cm-2. Physicochemical characterizations by scanning electron microscopy, Raman, FTIR, and in situ electrochemical quartz crystal microbalance (EQCM) techniques supported the entrapment of the molecular species. Furthermore, the scanning electrochemical microscopy (SECM) technique has been adopted for surface-mapping the true active site of the NAPQI-trapped electrode. As a biomimetic study, the mediated oxidation reaction of NADH by CB@NAPQI was demonstrated, and the mechanistic and quantitative aspects were studied using cyclic voltammetry, rotating disc electrode, amperometry, and flow injection analysis techniques. © 2023 American Chemical Society.

Numerical Investigation on Silicon based Hollow Core Photonic Crystal Fiber for sensing Multiple Virus

In recent years, spread of infection due to virus became whirlwind and creates threat to life in multiple ways. Hence there is in need to sense virus as early as possible in easier way. In this work we propose a multi virus sensor which senses IBV, H5N1, H9N2, and H4N6.Very low refractive index is sensed in this work with increased birefringence due to its elliptical core, where the samples are infiltrated. Numerical analysis is done using Finite Element Method. Among these 4 viruses, IBV has higher sensitivity, birefringence and lower confinement loss which belong to COVID family.88.56% of sensitivity is obtained at 1550nm with low confinement loss. © 2022 IEEE.

Structural and Computational Studies of Cobalt(II) and Copper(II) Complexes with Aromatic Heterocyclic Ligand

Two coordination complexes, a cobalt(II) complex tris(1,10-phenanthroline)-cobalt perchlorate hydrate, [Co(phen)3]·(ClO4)2·H2O(1), and a copper(II) complex tris(1,10-phenanthroline)-copper perchlorate 4-bromo-2-{[(naphthalene-1-yl)imino]methyl}phenol hydrate, [Cu(phen)3]·(ClO4)2·HL·[O] (2), [where, phen = 1,10-phenathroline as aromatic heterocyclic ligand, HL = 4-bromo-2-((Z)-(naphthalene-4-ylimino) methyl) phenol] have been synthesized and structurally characterized. Single crystal X-ray analysis of both complexes has revealed the presence of a distorted octahedral geometry around cobalt(II) and copper(II) ions. density functional theory (DFT)-based quantum chemical calculations were performed on the cationic complex [Co(phen)3]2+ and copper(II) complex [Cu(phen)3]2+ to get the structure property relationship. Hirshfeld surface and 2-D fingerprint plots have been explored in the crystal structure of both the metal complexes. To find potential SARS-CoV-2 drug candidates, both the complexes were subjected to molecular docking calculations with SARS-CoV-2 virus (PDB ID: 7BQY and 7C2Q). We have found stable docked structures where docked metal chelates could readily bound to the SARS-CoV-2 Mpro. The molecular docking calculations of the complex (1) into the 7C2Q-main protease of SARS-CoV-2 virus revealed the binding energy of −9.4 kcal/mol with a good inhibition constant of 1.834 µM, while complex (2) exhibited the binding energy of −9.0 kcal/mol, and the inhibition constant of 1.365 µM at the inhibition binding site of receptor protein. Overall, our in silico studies explored the potential role of cobalt(II) complex (1), and copper(II) complex (2) complex as the viable and alternative therapeutic solution for SARS-CoV-2.

Negligible risk of surface transmission of SARS-CoV-2 in public transportation.

BACKGROUND: Exposure to pathogens in public transport systems is a common means of spreading infection, mainly by inhaling aerosol or droplets from infected individuals. Such particles also contaminate surfaces, creating a potential surface-transmission pathway. METHODS: A fast acoustic biosensor with an antifouling nano-coating was introduced to detect SARS-CoV-2 on exposed surfaces in the Prague Public Transport System. Samples were measured directly without pre-treatment. Results with the sensor gave excellent agreement with parallel qRT-PCR measurements on 482 surface samples taken from actively used trams, buses, metro trains, and platforms between 7-9 April 2021, in the middle of the lineage Alpha SARS-CoV-2 epidemic wave when 1 in 240 people were COVID-19 positive in Prague. RESULTS: Only ten of the 482 surface swabs produced positive results and none of them contained virus particles capable of replication, indicating that positive samples contained inactive virus particles and/or fragments. Measurements of the rate of decay of SARS-CoV-2 on frequently touched surface materials showed that the virus did not remain viable longer than 1-4 hours. The rate of inactivation was the fastest on rubber handrails in metro escalators and the slowest on hard-plastic seats, window glasses, and stainless-steel grab rails. As a result of this study, Prague Public Transport Systems revised their cleaning protocols and the lengths of parking times during the pandemic. CONCLUSIONS: Our findings suggest that surface transmission played no or negligible role in spreading SARS-CoV-2 in Prague. The results also demonstrate the potential of the new biosensor to serve as a complementary screening tool in epidemic monitoring and prognosis.

A Sensitive Biosensor Based on Plasmonic-Graphene Configuration for Detection of COVID-19 Virus.

In this paper, four individual structures based on graphene-plasmonic nano combinations are proposed for detection of corona viruses and especially COVID-19. The structures are arranged based on arrays in the shapes of half-sphere and one-dimensional photonic crystal formats. The half-sphere and plate shaped layers are made of Al, Au, SiO2 and graphene. The one-dimensional photonic crystals lead the wavelength and peak corresponding to the absorption peak to lower and higher amounts, respectively. In order to improve the functionality of the proposed structures, effects of structural parameters and chemical potentials are considered. A defect layer of GZO is positioned in the middle of one-dimensional photonic crystal layers to shift the absorption's peak wavelength to the appropriate wavelength range for diagnosing corona viruses (~300 nm to 600 nm). The last proposed structure is considered as a refractive bio-sensor for detection of corona viruses. In the final proposed structure (based on different layers of Al, Au, SiO2, GZO and graphene), corona viruses are considered as the biomolecule layer and the results are obtained. The proposed bio-sensor can be a good and functional candidate for detection of corona viruses and especially COVID-19 in photonic integrated circuits with the satisfying sensitivity of ~664.8 nm/RIU (refractive index unit).