Nanosponges: As a Dynamic Drug Delivery Approach for Targeted Delivery

Recent advancements in nanotechnology have resulted in improved medicine delivery to the target site. Nanosponges are three-dimensional drug delivery systems that are nanoscale in size and created by cross-linking polymers. The introduction of Nanosponges has been a significant step toward overcoming issues such as drug toxicity, low bioavailability, and predictable medication release. Using a new way of nanotechnology, nanosponges, which are porous with small sponges (below one microm) flowing throughout the body, have demonstrated excellent results in delivering drugs. As a result, they reach the target place, attach to the skin's surface, and slowly release the medicine. Nanosponges can be used to encapsulate a wide range of medicines, including both hydrophilic and lipophilic pharmaceuticals. The medication delivery method using nanosponges is one of the most promising fields in pharmacy. It can be used as a biocatalyst carrier for vaccines, antibodies, enzymes, and proteins to be released. The existing study enlightens on the preparation method, evaluation, and prospective application in a medication delivery system and also focuses on patents filed in the field of nanosponges.Copyright © 2023 The Authors.

Synthesis, structural characterization, thermal analysis, DFT, biocidal evaluation and molecular docking studies of amide-based Co(II) complexes.

Abstract: Many distinct amino acid and aromatic amine-derived transition metal complexes are used as physiologically active compounds. A few Cobalt (II) complexes have been synthesized by reacting cobalt (II) chloride with 1, 8-diaminonapthalene-based tetraamide macrocyclic ligands in an ethanolic media. These synthesized ligands (TAML1-3) and associated Co(II) complexes were fully characterized with various spectroscopic techniques, such as IR, NMR, CHN analysis, EPR, molar conductance, and magnetic susceptibility measurements, TGA, UV-visible spectra, powder X-ray diffraction and DFT analysis. The IR spectra reveal interactions between the core metal atom and ligands through N of 1, 8-diaminonapthalene. The distorted octahedral geometry of synthesized Co(II) macrocyclic complexes were confirmed by ESR, UV-Vis and DFT studies. The synthesized ligands (TAML1-TAML3) and their Co(II) complexes were tested for antimicrobial activity against A. niger, C. albicans, and F. oxysporum in addition to bacteria like S. aureus, B. subtilis, and Gram-negative bacteria like E. coli. The ligand TAML1 and complex [Co(TAML1)Cl2] showed an excellent antibacterial activity. The minimum inhibitory concentration of TAML1 and [Co(TAML1)Cl2] against S. aureus were found to be 7 mm and 10 mm zone of inhibition at 500 ppm, respectively, compared to drug ampicillin (3 mm). Additionally, each molecule exhibited notable antioxidant activity. The biological significance of the synthesized compounds was then evaluated by molecular docking experiments with the active site of the receptor protein such as Sars-Cov-2, C. Albicans, X. campestris and E. coli. The molecular docking assisted data strongly correlated to the experimental approach of antimicrobial activity. Supplementary Information: The online version contains supplementary material available at 10.1007/s11696-023-02843-y.

Ligational behavior of bidentate nitrogen–oxygen donor 8‐quinolinolazodye toward Ni2+ and Zn2+ ions: Preparation, spectral, thermal, experimental, theoretical, and docking studies

The 5‐(4‐aryl azo)‐8‐hydroxyquinolines (L1–L3) and their metal complexes with Ni2+ and Zn2+ have been produced. Various spectroscopic techniques have been employed to analyze the ligand and complexes. The structures of the prepared compounds have been confirmed by Fourier transform infrared (FT‐IR), proton nuclear magnetic resonance (1H NMR), molar conductance, magnetic measurements, thermal gravimetric and differential thermal analyses (TG and DTA), and electronic transition. The FT‐IR spectra showed that the ligands are coordinated to the metal ions in a bidentate manner with donor sites of the azomethine‐N and phenolic‐OH. The FT‐IR and UV–Visible spectra were compared with the calculated results and showed a good agreement. The mass spectra concluded that the ligands' molecular weights and the calculated estimated m/z values match well. The complexes contain coordinated and hydrated water as confirmed by the TG results. The complexes are tetrahedral, trigonal bipyramid, and octahedral geometrical structures and act as non‐electrolytes in dimethylformamide (DMF) solvent. Using density functional theory (DFT) at the B3LYP level of theory and the 6‐311G** basis set for the C, H, N, Cl, and O atoms and the LANL2DZ basis set for the Ni and Zn atoms. Natural bond orbital (NBO) analysis was used to compute and describe the natural charge population and precise electronic configuration. The small energy gap between HOMO and LUMO energies suggests that charge transfer occurs within Ni2+ and Zn2+ complexes. The first‐order hyperpolarizability (β) of the complexes and the anisotropy of polarizability (α) values show promising optical properties. The electronic transitions of the prepared complexes were computed by time‐dependent density functional theory (TD‐DFT/PCM) with the B3LYP method using a 6‐31G** basis set. The ethanol polarizable continuum model (PCM) was used to simulate the solvent effect. Utilizing a computer virtual screening technique through molecular docking, the anticipation of binding of 8‐quinolinolazodye derivatives and their complexes with human CORONA virus protein (PDB ID: 5epw) was done. [ FROM AUTHOR] Copyright of Applied Organometallic Chemistry is the property of John Wiley & Sons, Inc. 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.)

Evaluating methods for estimating whole house air infiltration rates in summer: implications for overheating and indoor air quality

PurposeAccurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.Design/methodology/approachFifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.FindingsThe eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the "divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.Practical implicationsThe findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the "divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.Originality/valueDirect measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

Biobased polymer SF/PHBV composite nanofiber membranes as filtration and protection materials

With the emergence of the COVID-19, masks and protective clothing have been used in huge quantities. A large number of non-degradable materials have severely damaged the ecological environment. Now, people are increasingly pursuing the use of environmentally friendly materials to replace traditional chemical materials. Silk fibroin (SF) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) have received increasing attention because of their unique biodegradability and biocompatibility. In this paper, a series of biodegradable SF/PHBV nanofiber membranes with different PHBV content were fabricated by using electrospinning technology. The morphology of the electrospun SF/PHBV composite nanofiber was observed by scanning electron microscopy (SEM). The average diameters of the pure SF, SF/PHBV (4/1), SF/PHBV (3/1), and SF/PHBV (2/1) nanofibers were 55.16 ± 12.38 nm, 75.93 ± 21.83 nm, 69.35 ± 21.55 nm, and 61.40 ± 12.31 nm, respectively. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were used to explore the microstructure of the electrospun SF/PHBV composite nanofiber. The crystallization ability of the composite nanofiber was greatly improved with the addition of PHBV. The results of thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) indicated that the thermal stability of SF was better than PHBV obviously, so SF could improve the thermal stability of the composite materials within a certain range. The mechanical properties of the electrospun nanofiber membranes were evaluated by using a universal testing machine. In general, the elongation of the composite nanofiber membranes decreased, and the breaking strength increased with the addition of PHBV. The small pore size of the nanofiber membranes ensured that they had good application prospects in the field of filtration and protection. When the spinning time was 1 h, the filtration efficiency of SF/PHBV/PLA composite materials remained above 95%. © 2021 The Textile Institute.

Thermotropic effects of PEGylated lipids on the stability of HPPH-encapsulated lipid nanoparticles (LNP).

In this work, we demonstrate the enhanced thermal and steric stability of lipid-based formulations in the presence of encapsulated HPPH that have demonstrated potential cancer applications in previously presented in vivo studies. Differential scanning calorimeter (DSC) was used to study the phase transitions, and domain formations, and to qualify the thermodynamic properties associated with change in lipid bilayer behavior due to the presence of PEGylated at varying concentrations and sizes, and the encapsulated HPPH molecules. Thermal instability was quantified by dramatic changes in calculated enthalpy, and the shape of the melting peak or calculated half width of melting peak. This systematic study focused on understanding the effects of varying molecular mass and concentrations of PEG polymers in the photopolymerizable lipid DC8, 9PC lipid bilayer matrix for four weeks at room temperature of 25 °C. The major findings include increased thermal stability of the lipid bilayer due to the presence of PEG-2 K and the HPPH that resulted from the van der Waals forces between various molecular species, and the change in bilayer curvature confirmed via mathematical correlations. It is demonstrated that the encapsulation of therapeutics in lipid formulations can alter their overall thermal behavior, and therefore, it is imperative to consider calorimetric effects while designing lipid-based vaccines. The presented research methodologies and findings presented can predict the stability of lipid-based vaccines that are under development such as COVID-19 during their storage, transport, and distribution.

Ligational behavior of bidentate nitrogen–oxygen donor 8-quinolinolazodye toward Ni2+ and Zn2+ ions: Preparation, spectral, thermal, experimental, theoretical, and docking studies

The 5-(4-aryl azo)-8-hydroxyquinolines (L1–L3) and their metal complexes with Ni2+ and Zn2+ have been produced. Various spectroscopic techniques have been employed to analyze the ligand and complexes. The structures of the prepared compounds have been confirmed by Fourier transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR), molar conductance, magnetic measurements, thermal gravimetric and differential thermal analyses (TG and DTA), and electronic transition. The FT-IR spectra showed that the ligands are coordinated to the metal ions in a bidentate manner with donor sites of the azomethine-N and phenolic-OH. The FT-IR and UV–Visible spectra were compared with the calculated results and showed a good agreement. The mass spectra concluded that the ligands' molecular weights and the calculated estimated m/z values match well. The complexes contain coordinated and hydrated water as confirmed by the TG results. The complexes are tetrahedral, trigonal bipyramid, and octahedral geometrical structures and act as non-electrolytes in dimethylformamide (DMF) solvent. Using density functional theory (DFT) at the B3LYP level of theory and the 6-311G** basis set for the C, H, N, Cl, and O atoms and the LANL2DZ basis set for the Ni and Zn atoms. Natural bond orbital (NBO) analysis was used to compute and describe the natural charge population and precise electronic configuration. The small energy gap between HOMO and LUMO energies suggests that charge transfer occurs within Ni2+ and Zn2+ complexes. The first-order hyperpolarizability (β) of the complexes and the anisotropy of polarizability (α) values show promising optical properties. The electronic transitions of the prepared complexes were computed by time-dependent density functional theory (TD-DFT/PCM) with the B3LYP method using a 6-31G** basis set. The ethanol polarizable continuum model (PCM) was used to simulate the solvent effect. Utilizing a computer virtual screening technique through molecular docking, the anticipation of binding of 8-quinolinolazodye derivatives and their complexes with human CORONA virus protein (PDB ID: 5epw) was done. © 2022 John Wiley & Sons Ltd.

Thermal characteristics and combustion reactivity of coronavirus face masks using TG-DTG-MS analysis.

The presented paper deals with the influence of the heating rate on combustion characteristics (reactivity and reactivity evaluation, ignition index (D i), burnout index (D f), the combustion performance index (S), and the combustion stability index (R W)) of the protective coronavirus face masks. Two types of commonly used face masks in different state (new and exploited) were investigated by TG-DTG analysis in an air atmosphere, directly coupled with mass spectrometry (MS). Based on the experimental results, the impact of ultimate and proximate analysis data on the evolved gas analysis (EGA) was discussed. Also, the derived values from thermo-analytical (TA) data were compared with the literature reports, related to individual constitutive face mask materials. According to the performed research, it was established that different maximal reaction rate values at various heating rates indicate the complex nature of coronavirus face mask thermo-oxidative degradation, which is stimulated with carbon oxidation reactions and volatile matter (VM) release. By detailed analysis of obtained TG-DTG profiles, it was established that process takes place through the multiple-step reaction pathways, due to many vigorous radical reactions, causes by polymers degradation. The performed research was done to evaluate the possible utilization of coronavirus waste to energy production and sustainable pandemic environmental risk reduction.

Coppers film fabrication on glass substrate by complex reduction method for rapid inactivation of SARS-CoV-2 (COVID-19)

A Cu film with the ability to rapidly inactivate the COVID-19 virus was easily fabricated at approximately 23°C on a Na-free glass substrate. The well-adhered Cu films with thickness of approximately 16 μm and surface area of 8.71 10-3 m2 g-1 were obtained by immersion of the glass substrate into an aqueous solution with dissolved Cu (II) complex of ammonia and ascorbic acid. The interface bonded between the film and glass substrate was very strong, such that the film did not peel off even when it was exposed to an ultrasonic wave of 100 mW (42 kHz) in water. The anti-COVID-19 activity in Dulbecco's modified Eagle's medium (DMEM) is effective within 2 h and is faster than that of commercial copper plates. The changes in the relative abundance of Cu2O and CuO crystallines on the Cu film due to DMEM treatment and those in surface morphology were examined by X-ray diffraction peak analysis and field emission-scanning electron microscopy, respectively. The flame atomic absorption analyses of the recovered solutions after DMEM treatment indicated that the Cu ions from the Cu film with DMEM treatment for 1 hour at a concentration of 0.64 ± 0.03 ppm were eluted 2.3 times faster than those from the Cu plate. The rapid elution of Cu ions from Cu2O crystallines on the film in the early stage is the primary factor in the inactivation of the COVID-19 virus, as elucidated from the time dependence of eluted Cu ions by DMEM treatment. Results from thermogravimetric and differential thermal analysis (TG-DTA) of the powder scratched from the Cu film suggested that a trace amount of organic residues remaining in the Cu film was important in the rapid activity. © 2022 World Scientific Publishing Company.

Reassessing Undergraduate Polymer Chemistry LaboratoryExperiments for Virtual Learning Environments br

Chemistry laboratory experiments are invaluable tostudents'acquisition of necessary synthetic, analytical, andinstrumental skills during their undergraduate studies. However,the COVID-19 pandemic rendered face-to-face (f2f), in-personteaching laboratory experiences impossible from late 2019-2020and forced educators to rapidly develop new solutions to deliverchemistry laboratory education remotely. Unfortunately, achievinglearning and teaching objectives to the same caliber of in-personexperiments is very difficult through distance learning. Toovercome these hurdles, educators have generated many virtual and remote learning options for not only foundational chemistrycourses but also laboratory experiments. Although the pandemic challenged high-level chemistry education, it has also created anopportunity for both students and educators to be more cognizant of virtual learning opportunities and their potential benefits withinchemistry curriculum. Irrespective of COVID-19, virtual learning techniques, especially virtual lab experiments, can complement f2flaboratories and offer a cost-efficient, safe, and environmentally sustainable alternative to their in-person counterparts.Implementation of virtual and distance learning techniques???including kitchen chemistry and at-home laboratories, prerecordedvideos, live-stream video conferencing, digital lab environment, virtual and augmented reality, and others???can provide a wide-ranging venue to teach chemistry laboratories effectively and encourage diversity and inclusivity in thefield. Despite their relevanceto real-world applications and potential to expand upon fundamental chemical principles, polymer lab experiments areunderrepresented in the virtual platform. Polymer chemistry education can help prepare students for industrial and academicpositions. The impacts of polymers in our daily life can also promote students'interests in science and scientific research. Hence, thetranslation of polymer lab experiments into virtual settings improves the accessibility of polymer chemistry education. Herein, weassess polymer experiments in the emergence of virtual learning environments and provide suggestions for further incorporation ofeffective polymer teaching and learning techniques into virtual settings

A Telecare System for Use in Traditional Persian Medicine

Background: In Persian Medicine (PM), measuring the wrist temperature/humidity and pulse is one of the main methods for determining a person's health status and temperament. An important problem is the dependence of the diagnosis on the physician's interpretation of the above-mentioned criteria. Perhaps this is one reason why this method has yet to be combined with modern medical methods. Also, sometimes there is a need to use PM to diagnose patients remotely, especially during a pandemic. This brings up the question of how to implement PM into a telecare system. This study addresses these concerns and outlines a system for measuring pulse signals and temperament detection based on PM. Methods: A system was designed and clinically implemented based on PM that uses data from recorded thermal distribution, a temperament questionnaire, and a customized device that logs the pulse waves on the wrist. This system was used for patient care via telecare. Results: The temperaments of 34 participants were assessed by a PM specialist using the standardized Mojahedi Mizaj Questionnaire (MMQ). Thermal images of the wrist in the supine position (named Malmas in PM), the back of the hand, and the entire face were also recorded under the supervision of the physician. Also, the wrist pulse waves were evaluated by a customized pulse measurement device. Finally, the collected data could be sent to a physician via a telecare system for further interpretation and prescription of medications. Conclusion: This preliminary study focused on the implementation of a combinational hardware-software system for patient assessment based on PM. It appears that the design and construction of a customized device that can measure the pulse waves, and some other criteria, according to PM, is possible and can decrease the dependency of the diagnostic to PM specialists. Thus, it can be incorporated into a telemedicine system. © 2021 Nafisi and Ghods.

Chemical, Thermal, and Rheological Performance of Asphalt Binder Containing Plastic Waste

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

The 12th International Conference on Instrumental Analysis—Modern Trends and Applications (20–23 September 2021, Virtual Event)

The 12th International Conference on “Instrumental Methods of Analysis” www.ima2021.gr (accessed on 8 November 2021)), was organized by the Aristotle University of Thessaloniki and National Technical University of Athens, during 20–23 September 2021 as a virtual event, providing the opportunity for high-level analytical scientists from all around the world to promote their relevant research. Covered topics included: spectrometric and electrometric analysis;chromatographic, mass spectrometric, microscopic, and thermal analysis methods;proteomics, metabolomics, metallomics, and elemental speciation analysis;chemical and biosensors;field analysis—mobile analytical instruments;miniaturized analytical systems (lab-on-a-chip), micro-, and nanofluidics;immunoassays and electrophoretic separation techniques;sampling techniques and strategies;robotics and automation;quality control—quality assurance in analysis;metrology;data processing and chemometrics;environmental analysis;biomedical (ecotoxicological and clinical) and pharmaceutical analysis;food analysis;materials analysis (nanomaterials, smart/advanced materials, and surface analysis);archaeometry;and analytical chemistry markets and possibilities for commercialization. Integration of the data gathered through these tools requires both a comprehensive framework for instrumental analysis that can cover efficiently all environmental compartments, human matrices, and even waste and wastewater, and an intelligent multi-scalar dynamic computational platform that allows us to capture effectively the environmental and social dynamics that govern the disease spread and severity. First confirmed detection of SARS-CoV-2 in untreated wastewater in Australia: A proof of concept for the wastewater surveillance of COVID-19 in the community.

Experimental investigations into abrasive flow machining (AFM) of 3D printed ABS and PLA parts

PurposeThe surface roughness of additively manufactured parts is usually found to be high. This limits their use in industrial and biomedical applications. Therefore, these parts required post-processing to improve their surface quality. The purpose of this study is to finish three-dimensional (3D) printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) parts using abrasive flow machining (AFM).Design/methodology/approachA hydrogel-based abrasive media has been developed to finish 3D printed parts. The developed abrasive media has been characterized for its rheology and thermal stability using sweep tests, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The ABS and PLA cylindrical parts have been prepared using fused deposition modeling (FDM) and finished using AFM. The experiments were designed using Taguchi (L9 OA) method. The effect of process parameters such as extrusion pressure (EP), layer thickness (LT) and abrasive concentration (AC) was investigated on the amount of material removed (MR) and percentage improvement in surface roughness (%ΔRa).FindingsThe developed abrasive media was found to be effective for finishing FDM printed parts using AFM. The microscope images of unfinished and finished showed a significant improvement in surface topography of additively manufactures parts after AFM. The results reveal that AC is the most significant parameter during the finishing of ABS parts. However, EP and AC are the most significant parameters for MR and %ΔRa, respectively, during the finishing of PLA parts.Practical implicationsThe FDM technology has applications in the biomedical, electronics, aeronautics and defense sectors. PLA has good biodegradable and biocompatible properties, so widely used in biomedical applications. The ventilator splitters fabricated using FDM have a profile similar to the shape used in the present study.Research limitations/implicationsThe present study is focused on finishing FDM printed cylindrical parts using AFM. Future research may be done on the AFM of complex shapes and freeform surfaces printed using different additive manufacturing (AM) techniques.Originality/valueAn abrasive media consists of xanthan gum, locust bean gum and fumed silica has been developed and characterized. An experimental study has been performed by combining printing parameters of FDM and finishing parameters of AFM. A comparative analysis in MR and %ΔRa has been reported between 3D printed ABS and PLA parts.

Numerical-statistical study of the prognostic efficiency of the SEIR model

A comparative analysis of the differential and the corresponding stochastic Poisson SEIR-models is performed for the test problem of COVID-19 epidemic in Novosibirsk modelling the period from March 23, 2020 to June 21, 2020 with the initial population N = 2 798 170. Varying the initial population in the form N = n m with m ⩾ 2, we show that the average numbers of identified sick patients is less (beginning from April 7, 2020) than the corresponding differential values by the quantity that does not differ statistically from C(t)/m, with C ≈ 27.3 on June 21, 2020. This relationship allows us to use the stochastic model for big population N. The practically useful ‘two sigma’ confidential interval for the time interval from June 1, 2020 to June 21, 2020 is about 108% (as to the statistical average) and involves the corresponding real statistical estimates. The influence of the introduction of delay on the prognosis, i.e., the incubation period corresponding to Poisson model is also studied.

Synthesis, characterization, and computational study of copper bipyridine complex [Cu (C18H24N2) (NO3)2] to explore its functional properties.

In the present study, copper (II) complex of 4, 4'-di-tert-butyl-2,2'-bipyridine [Cu (C18H24N2) (NO3)2], 1 is investigated through its synthesis and characterization using elemental analysis technique, infra-red spectroscopy, and single-crystal analysis. The compound 1 crystallizes in orthorhombic space group P212121. The copper atom in the mononuclear complex is hexa coordinated through two nitrogen and four oxygen atoms from bipyridine ligand and nitrate ligands. The thermal analysis depicts the stability of the entitled compound up to 170 °C, and the decomposition takes place in different steps between 170 and 1000 °C. Furthermore, quantum chemical techniques are used to study optoelectronic, nonlinear optical, and therapeutic bioactivity. The values of isotropic and anisotropic linear polarizabilities of compound 1 are calculated as 41.65 × 10-24 and 23.02 × 10-24 esu, respectively. Likewise, the static hyperpolarizability is calculated as 47.92 × 10-36 esu using M06 functional compared with para-nitroaniline (p-NA) and found several times larger than p-NA. Furthermore, the antiviral potential of compound 1 is studied using molecular docking technique where intermolecular interactions are checked between the entitled compound and two crucial proteins of SARS-CoV-2 (COVID-19). Our investigation indicated that compound 1 interacts more vigorously to spike protein than main protease (MPro) due to its better binding energy of -9.60 kcal/mol compared with -9.10 kcal/mol of MPro. Our current study anticipated that the above-entitled coordination complexes could be potential candidates for optoelectronic properties and their biological activity.

Synthesis, spectroscopy, crystal structure, TGA/DTA study, DFT and molecular docking investigations of (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one.

In this study, we present the synthesis of novel pyridazin-3(2H)-one derivative namely (E)-4-(4-methylbenzyl)-6-styrylpyridazin-3(2H)-one (MBSP). The chemical structure of MBSP was characterized using spectroscopic techniques such as FT-IR, 1H NMR, 13C NMR, UV-Vis, ESI-MS, and finally, the structure was confirmed by single X-ray diffraction studies. The DFT calculation was performed to compare the gas-phase geometry of the title compound to the solid-phase structure of the title compound. Furthermore, a comparative study between theoretical UV-Vis, IR, 1H- and 13C NMR spectra of the studied compound and experimental ones have been carried out. The thermal behavior and stability of the compound were analyzed by using TGA and DTA techniques which revealed that the compound is thermostable up to its melting point. Finally, the in silico docking and ADME studies are performed to investigate whether MBSP is a potential therapeutic for COVID-19.