Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur...Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product.This composite comprises Ru nanoclusters supported on the CuS nanostructure,achieved through simple pulsed laser irradiation in liquid approach.The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity,exhibiting a negligible working potential of 0.28 V(vs.RHE)for the anodic sulfion oxidation reaction(SOR)and a minimal overpotential of 182 m V for cathodic hydrogen evolution reaction(HER)to achieve 10 mA cm^(-2)of current density.Moreover,the Cu S/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions.Remarkably,in a two-electrode electrolyzer system utilizing Cu S/Ru-30 as both the anode and cathode,the SOR+HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm^(-2),which is considerably lesser compared to the OER+HER coupled water electrolysis(1.85 V).The experimental results and density function theory(DFT)calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field,greatly enhancing electron transfer efficiency.This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates.This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.展开更多
Defect engineering,especially oxygen vacancies(O-vacancies) introduction into metal oxide materials has been proved to be an effective strategy to manipulate their surface electron exchange processes.However,quantitat...Defect engineering,especially oxygen vacancies(O-vacancies) introduction into metal oxide materials has been proved to be an effective strategy to manipulate their surface electron exchange processes.However,quantitative investigation of O-vacancies on CO2 electroreduction still remains rather ambiguous.Herein,a series of nanoporous tin oxide(SnOx) materials have been prepared by thermal treatment at various temperatures and reaction conditions.The annealing temperature dependent Ovacancies property of the SnOx was revealed and attributed to the balance tunning of the desorption of oxygen species and the continous oxidation of SnOx.The as-prepared nanoporous SnOx with 300℃treatment was found to be highest O-vacant material and showed an impressive CO2 RR activity and selectivity towards the conversion of CO2 into formic acid(up to 88.6%),and superior HCOOH incomplete current density to other samples.The ideal performance of the O-vacancies rich SnOx-300 material can be ascribed to the high delocalized electron density inducing much enhanced adsorption of CO2 with O binding and benefiting the subsequent reduction with high selectively forming of formic acid.展开更多
Polysaccharide-based bionanocomposite hydrogels with functional nanomaterials were used in biomed- ical applications. Self-organization of xanthan gum and chitosan in the presence of iron oxide magnetic nanoparticles ...Polysaccharide-based bionanocomposite hydrogels with functional nanomaterials were used in biomed- ical applications. Self-organization of xanthan gum and chitosan in the presence of iron oxide magnetic nanoparticles (Fe304 MNPs) allowed us to form magnetically responsive polyelectrolyte complex hydro- gels (MPECHs) via insitu ionic complexation using D-(+)-glucuronic acid ^-lactone as a green acidifying agent. Characterization confirmed the successful formation of (and structural interactions within) the MPECH and good porous structure. The rheological behavior and compressive properties of the PECH and MPECH were measured. The results indicated that the incorporation of Fe304 MNPs into the PECH greatly improved mechanical properties and storage modulus (G'). In vitro cell culture of NIH3T3 fibroblasts on MPECHs showed improvements in cell proliferation and adhesion in an external magnetic field relative to the pristine PECH. The results showed that the newly developed MPECH could potentially be used as a magnetically stimulated system in tissue engineering applications.展开更多
A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,...A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,three different iron phthalocyanines(FePcs)adsorbed on carbon nanotubes((NH2)4FePc@CNTs,(t-Bu)4FePc@CNTs,and FePc@CNTs)were evaluated to demonstrate the effect of the electron donating power of the substituents on the Fe^(3+)/Fe^(2+)redox potential of FePc@CNTs and the role of these composites as ORR mediators in alkaline media.The Fe^(3+)/Fe^(2+)redox potential of the FePcs was found to shift towards the cathodic region upon substitution with electron-donating groups.This up-field shift in the eg-orbital leads to a lower overlap between the onset potential of the Fe^(3+)/Fe^(2+)redox couple and that of the ORR,and thus,the ORR activity decreased in the following order based on the substitution of FePc:-H>-t-Bu>-NH2.展开更多
The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and th...The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical展开更多
The use of nanofillers with high surface area and extreme purity in polymer composite is an effective strategy to obtain high performance polymeric nanocomposites.Therefore,the effect of nanofillers such as carbon nan...The use of nanofillers with high surface area and extreme purity in polymer composite is an effective strategy to obtain high performance polymeric nanocomposites.Therefore,the effect of nanofillers such as carbon nanotubes(CNT),titanium dioxide(TiO_(2)),and their hybrid on rubber-based composites was studied.In this study,rubber nanocomposites were fabricated by using room temperature vulcanized(RTV)silicone rubber matrix and nanofillers(i.e.CNT,TiO_(2),and CNT-TiO_(2))through solution casting method.Here,the purity and surface area of CNT(purity:>96%and BET surface area:300 m2/g)and TiO_(2)(purity:>98%and BET surface area:165 m2/g)were estimated by field emission scanning electron microscopy/energy dispersive X-ray(FESEM-EDX)and adsorption isotherms.The mechanical properties of the rubber nanocomposites were enhanced by incorporating nanofillers.The compressive modulus was 2.18 MPa for unfilled composites and increased to 6.8 MPa(CNT),3.95 MPa(CNT-TiO_(2)),and 2.44 MPa(TiO_(2))at 5 phr,respectively.Similarly,the tensile strength was 0.54 MPa for unfilled composites and increased to 1.37 MPa(CNT),1.33 MPa(CNT-TiO_(2))and 0.61 MPa(TiO_(2))at 5 phr,respectively.Further,the actuation displacement was improved with increasing input voltage and it was 2 mm for CNT,1.6 mm for CNT-TiO_(2) hybrid and 0.5 mm for TiO_(2) at 10 kV.Moreover,a series of experiments show the potential application in piezoelectric actuation.展开更多
Objective:To explore natural compounds as potential inhibitors against main protease(Mpro)of SARS-CoV-2.Methods:In the current study,systematic molecular docking analysis was conducted using AutoDock 4.2 to determine ...Objective:To explore natural compounds as potential inhibitors against main protease(Mpro)of SARS-CoV-2.Methods:In the current study,systematic molecular docking analysis was conducted using AutoDock 4.2 to determine the binding affinities and interactions between natural compounds and Mpro.Selected natural compounds were further validated using a combination of molecular dynamic(MD)simulations and molecular mechanic Poisson-Boltzmann surface area(MM/PBSA)free energy c alculation s.Results:Out of twenty natural compounds,four natural metabolites namely,amentoflavone,guggulsterone,puerarin,and piperine were found to have strong interaction with Mpro of SARS-CoV-2 based on docking analysis.During MD simulations,all four natural compounds bound to Mpro at 50 ns and MM/G/P/BSA free energy calculations showed that all four shortlisted ligands had stable and favorable energies with strong binding to Mpro protein.Conclusions:Guggulsterone is a potential inhibitor of COVID-19 main protease Mpro.Further in vitro and pre-clinical studies are needed.展开更多
Design of supportive atomic sites with a controllably adjusted coordinating environment is essential to advancing the reduction of CO_(2) to value-added fuels and chemicals and to achieving carbon neutralization.Herei...Design of supportive atomic sites with a controllably adjusted coordinating environment is essential to advancing the reduction of CO_(2) to value-added fuels and chemicals and to achieving carbon neutralization.Herein,atomic Ni(Zn)sites that are uniquely coordinated with ternary Zn(Ni)/N/O ligands were successfully decorated on formamide-derived porous carbon nanomaterials,possibly forming an atomic structure of Ni(N_(2)O_(1))-Zn(N_(2)O_(1)),as studied by combining X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.With the mediation of additional O coordination,the Ni-Zn dual site induces significantly decreased desorption of molecular CO.The NiZn-NC decorated with rich Ni(N_(2)O_(1))-Zn(N_(2)O_(1))sites remarkably gained>97%CO Faraday efficiency over a wide potential range of -0.8 to -1.1 V(relative to reversible hydrogen electrode).Density functional theory computations suggest that the N/O dual coordination effectively modulates the electronic structure of the Ni-Zn duplex and optimizes the adsorption and conversion properties of CO_(2) and subsequent intermediates.Different from the conventional pathway of using Ni as the active site in the Ni-Zn duplex,it is found that the Ni-neighboring Zn sites in the Ni(N_(2)O_(1))-Zn(N_(2)O_(1))coordination showed much lower energy barriers of the CO_(2) protonation step and the subsequent dehydroxylation step.展开更多
Melanoma is a perfidious form of skin cancer.The study offers a hybrid framework for the automatic classification of melanoma.An Auto-matic Melanoma Detection System(AMDS)is used for identifying melanoma from the infe...Melanoma is a perfidious form of skin cancer.The study offers a hybrid framework for the automatic classification of melanoma.An Auto-matic Melanoma Detection System(AMDS)is used for identifying melanoma from the infected area of the skin image using image processing techniques.A larger number of pre-existing automatic melanoma detection systems are either commercial or their accuracy can be further improved.The research problem is to identify the best preprocessing technique,feature extractor,and classifier for melanoma detection using publically available MED-NODE data set.AMDS goes through four stages.The preprocessing stage is for noise removal;the segmentation stage is for extracting lesions from infected skin images;the feature extraction stage is for determining the features like asymmetry,border,and color,and the classification stage is to classify the lesion as benign or melanoma.The infected input image for the AMDS may contain impurities such as noise,illumination,artifacts,and hairs.In the proposed methodology an algorithm LePrePro is proposed for the prepro-cessing stage for denoising and brightness cum contrast normalization and another algorithm LeFET is proposed for extending the feature vector space in the feature extraction stage using a hybrid approach.In the study,a novel approach has been proposed in which different classifiers,feature extractions,and data preprocessing steps of the AMDS are compared.In a conclusion,this comparison revealed that on experimentation using Med-Node and ISIC 2017 Dataset,the best results included Gaussian blur as the best data preprocessing step,Extended feature vector which is the combination of Hue Saturation Value(HSV),and Local Binary Pattern(LBP)was the best feature extraction method,and the ensemble bagged tree was the best classification technique on the Med-Node data sets with 99%Area Under the Receiver Operating Characteristic Curve(AUC),93.52%accuracy,90.82%sensitivity,and 98.36%specificity in the proposed automatic melanoma detection system.展开更多
Environment monitoring has become a necessity because of global warming and climate change. All across the globe researchers are trying to monitor the environmental parameters of temperature, humidity and pollutants g...Environment monitoring has become a necessity because of global warming and climate change. All across the globe researchers are trying to monitor the environmental parameters of temperature, humidity and pollutants gases mere precisely in real time. Sensing system using sensor arrays has been developed to monitor indoor environment, however, these systems are costly and have not gained wide acceptance. Precise monitoring of building environment has a huge potential in terms of energy savings. In this paper, an effort has been made to develop a 4-channel energy efficient and low cost data logger for indoor environment. The Data logger is proposed to be developed with the use of PIC 18F4458. Real Time Clock and EEPROM are interfaced for sampled data with the instance of sampling time and month/date/year;these sampled data will be stored in the EEPROM to the note pad tabular form with the help of graphical user interface (GUI).展开更多
Despite the fact that low-dimensional carbons(LDCs,1D/2D)materials are very interesting due to their intriguing electrical properties,we still attempt to enrich them by high N-content in order to enjoy their electro-a...Despite the fact that low-dimensional carbons(LDCs,1D/2D)materials are very interesting due to their intriguing electrical properties,we still attempt to enrich them by high N-content in order to enjoy their electro-applications.We here report a template-free synthesis of 1D/2D LDC with high N content(>40 at%)and tunable aspect ratios from molecular formamide(FA).The 1D/2D LDC is in polyaminoimidazole as confirmed by pair distribution function analysis,and 1D growth mode can be altered to 2D by simply adding a 2D-guiding molecule of melamine.Electrochemical properties of the LDC can befinely tuned by adjusting the solvothermal temperature and melamine dosage.It is revealed that the optimal 2D LDC delivers superior O2-to-H_(2)O_(2) yield(687.2 mmol⋅g^(-1)⋅h^(-1))and Faradic efficiency(87.5%).Considering the heavy N content and high adjustability of aspect ratio,the FAderived LDCs potentially open new synthesis routes for structural carbon materials for broad electrochemical applications.展开更多
Background:Betel nut/areca nut/Areca catechu is one of the most commonly used psychoactive substance,and is also a major preventable cause of cancer.Unlike other psychoactive substances,such as nicotine,the mechanisms...Background:Betel nut/areca nut/Areca catechu is one of the most commonly used psychoactive substance,and is also a major preventable cause of cancer.Unlike other psychoactive substances,such as nicotine,the mechanisms underlying addiction to areca nuts and related oncogenesis remain elusive.Recent reports suggest a possible overlap in the mechanisms of action of nicotine and areca nuts in the human body.Thus,this study aimed to investigate the interactome of human proteins associated with areca nut exposure and the intricate similarities and differences in the effects of the two psychoactive substances on humans.Methods:A list of proteins associated with areca nut use was obtained from the available literature using terms from Medical Subject Headings(MeSH).Protein-protein interaction(PPI)networks and functional enrichment were analyzed.The results obtained for both psychoactive substances were compared.Results:Given the limited number of common proteins(36/226,16%)in the two sets,a substantial overlap(612/1176 nodes,52%)was observed in the PPI networks,as well as in Gene Ontology.Areca nuts mainly affect signaling pathways through three hub proteins(alpha serine/threonine-protein kinase,tumor protein 53,and interleukin-6),which are common to both psychoactive substances,as well as two unique hub proteins(epidermal growth factor receptor and master regulator of cell cycle entry and proliferative metabolism).Areca nut-related proteins are associated with unique pathways,such as extracellular matrix organization,lipid storage,and metabolism,which are not found in nicotine-associated proteins.Conclusions:Areca nuts affect regulatory mechanisms,leading to systemic toxicity and oncogenesis.Areca nuts also affect unique pathways that can be studied as potential markers of exposure,as well as targets for anticancer therapeutic agents.展开更多
Efficient electrocatalytic rupture of energy-rich molecules(H_(2)and O_(2))is a green approach for gener-ating clean energy for modern societies.In this context,porphyry-type molecular electrocatalysts act intelligent...Efficient electrocatalytic rupture of energy-rich molecules(H_(2)and O_(2))is a green approach for gener-ating clean energy for modern societies.In this context,porphyry-type molecular electrocatalysts act intelligently toward oxygen reduction reaction(ORR),a fundamental process in fuel cells,due to their redox-rich chemistry,which involves core metal ions and macrocyclic ligands.The concerned scientific community has tried many times to correlate the ORR intermediates with their formation kinetics and simplify the associated multi H+/e-stages during the ORR process,constructing several volcano plots be-tween catalytic Tafel data,turnover frequencies,and overpotentials for many electrocatalysts.Despite the fact that many review articles on molecular electrocatalysts for ORR have been published,understanding the strategic implications and molecular catalyst intelligence towards homogenous ORR has been poorly explored.This review examined the relationships between volcano plots of current vs.thermodynamic parameters and the Sabatier principle in order to explain the intelligence of molecular electrocatalysts and approaches for their creation,as well as the difficulties and potential prospects of molecular electro-catalysts.These facts distinguish this review from previously published articles and will pique the scien-tific community’s interest in avoiding trial-and-error procedures for catalyst creation while also allowing for more exact evaluations of the molecular catalyst’s performance.展开更多
Inspired by molecular catalysts,researchers developed atomically precise nitrogen-coordinated single or dual metal sites imbedded in graphitized carbon(M-N-C)to fully utilize metallic sites for 02activation.These cata...Inspired by molecular catalysts,researchers developed atomically precise nitrogen-coordinated single or dual metal sites imbedded in graphitized carbon(M-N-C)to fully utilize metallic sites for 02activation.These catalysts performed remarkably well in the electrocatalytic oxygen reduction reaction(ORR)due to their distinct coordination and electrical structures,Nonetheless,their maximum efficacy in practical applications has yet to be achieved.This agenda identifies tailoring the coordination environment,spin states,intersite distance,and metal-metal interaction as innovative approaches to regulate the ORR performance of these catalysts.However,it is necessary to undertake a precise assessment of these methodologies and the knowledge obtained to be implemented in the design of future M-N-C catalysts for ORR.Therefore,this review aims to analyze recent progress in M-N-C ORR catalysts,emphasizing their innovative engineering with aspects such as alteration in intersite distance,metal-metal interaction,coordination environment,and spin states.Additionally,we critically discuss how to logically monitor the atomic structure,local coordination,spin,and electronic states of M-N-C catalysts to modulate their ORR activity.We have also highlighted the challenges associated with M-N-C catalysts and proposed suggestions for their future design and fabrication.展开更多
Carbon materials featuring hierarchical pores and atomically dispersed metal sites are promising catalysts for energy storage and conversion applications.Herein,we developed a facile strategy to construct functional c...Carbon materials featuring hierarchical pores and atomically dispersed metal sites are promising catalysts for energy storage and conversion applications.Herein,we developed a facile strategy to construct functional carbon materials with a fluffy peony-like structure and dense binary FeCo-Nx active sites(termed as f-FeCo-CNT).By regulating the metal content in precursors,a three-dimensional(3D)interconnected conductive carbon nanotubes network was in-situ formed throughout the atomically dispersed FeCo-NC matrix during pyrolysis.Taking advantage of rich pore hierarchy and co-existence of highly active FeCo-Nx sites and beneficial FeCo alloy nanoparticles,the f-FeCo-CNT material exhibited excellent bifunctional performance towards oxygen reduction reaction/oxygen evolution reactions(ORR/OER)with respect to the atomically dispersed FeCo-NC(SA-f-FeCo-NC)and commercial Pt/C+Ru02 mixture,surpassing the SA-f-FeCo-NC with a 20 mV higher ORR half-wave potential and a 100 mV lower OER overpotential(at 10.0 mA/cm^2).Remarkably,the f-FeCo-CNT-assembled Zn-air battery(ZAB)possessed a maximum specific power of 195.8 mW/cm^2,excellent rate capability,and very good cycling stability at large current density of 20.0 mA/cm^2.This work provides a facile and feasible synthetic strategy of constructing low-cost cathode materials with excellent comprehensive ZAB performance.展开更多
In this article,we review the advancement in nanoseparation and concomitant purification of nanoparticles(NPs) by using density gradient ultracentrifugation technique(DGUC) and demonstrated by taking several typical e...In this article,we review the advancement in nanoseparation and concomitant purification of nanoparticles(NPs) by using density gradient ultracentrifugation technique(DGUC) and demonstrated by taking several typical examples.Study emphasizes the conceptual advances in classification,mechanism of DGUC and synthesis-structure-property relationships of NPs to provide the significant clue for the further synthesis optimization.Separation,concentration,and purification of NPs by DGUC can be achieved at the same time by introducing the water/oil interfaces into the separation chamber.We can develop an efficient method ‘‘lab in a tube" by introducing a reaction zone or an assembly zone in the gradient to find the surface reaction and assembly mechanism of NPs since the reaction time can be precisely controlled and the chemical environment change can be extremely fast.Finally,to achieve the best separation parameters for the colloidal systems,we gave the mathematical descriptions and computational optimized models as a new direction for making practicable and predictable DGUC separation method.Thus,it can be helpful for an efficient separation as well as for the synthesis optimization,assembly and surface reactions as a potential cornerstone for the future development in the nanotechnology and this review can be served as a plethora of advanced notes on the DGUC separation method.展开更多
During disease outbreak,it has been observed that information about the disease prevalence induces the individuafs behavioral changes.This information is usually assumed to be generated by the density of infective ind...During disease outbreak,it has been observed that information about the disease prevalence induces the individuafs behavioral changes.This information is usually assumed to be generated by the density of infective individuals and active mass media.The delay in reporting of these infective individuals may have its impact on generated information.Hence,to study the impact of delay on information generation,and therefore on the disease dynamics,a delay differential equation model is proposed and analyzed.The dynamics of information with delay effect is also modeled by a separate rate equation.Model analysis is performed and a unique infected equilibrium is obtained when the basic reproduction number(R0)is greater than one,whereas the disease free equilibrium always exists.When R0<1,the disease free equilibrium is found to be locally stable independent of delay effect.The unique infected equilibrium is found to be locally stable till delay reaches a threshold value.The global stability of the unique infected equilibrium is also established under some parametric conditions by constructing a suitable Lyapunov function.The occurrence of Hopf bifurcation is observed when the delay in information crosses the threshold value.Analytically,the direction and stability of bifurcating periodic solutions is established.Further,we observed the occurrence of Hopf-Hopf bifurcation at two different delays.At first delay threshold,the endemic equilibrium loses its st ability and produces periodic oscillations via Hopf bifurcation.It further regains its stability at second delay threshold via another Hopf bifurcation.Hence,the delay effect on information shows possibility of stability switches.Numerical experiments are carried out to support the obtained analytical results.Our study infers that the disease will show persistent oscillations if there is a significant time lag in reporting of infective after the disease outbreak.Thus,the delay in dissemination of information shows rich and complex dynamics in the model and provides important insights.We also observe numerically that the saturation in information plays a significant role on stability of infected equilibrium in presence of delay.展开更多
Objective:To study the bioactivity of methanolic extract of Brassica juncea on animal model of diabetes mellitus along with its effect on diabetic and metabolic parameters.Methods:Diabetes mellitus was induced in rats...Objective:To study the bioactivity of methanolic extract of Brassica juncea on animal model of diabetes mellitus along with its effect on diabetic and metabolic parameters.Methods:Diabetes mellitus was induced in rats by injecting streptozotocin(60 mg/kg)intraperitonealy.Blood glucose was measured on day 3 by GOD-POD method to confirm the diabetes mellitus.Rats having fasting blood glucose>250 mg/d L were further selected for study and they were divided into four groups,control,control+streptozotocin,streptozotocin+metformin(75 mg/kg)and streptozotocin+extract of B.juncea(450 mg/kg).Each group consisted of six rats of either sex.Metformin and experimental extract were administered for 21 d.Triglyceride,cholesterol level were measured on day 21 by commercially available kit.Blood glucose was measured on days 7 and 21.Anti-oxidant potential was assessed by estimating extent of lipid peroxidation(LPO)by malondialdehyde(MDA),nitric oxide(NO),superoxide dismutase(SOD)and glutathione(GSH)in liver,kidney,pancreas,muscle tissues on day 21.Unpaired and paired student’s t-test was applied for statistical analysis.Results:The extract of B.juncea showed significant decrease in blood glucose level on day 21.The treatment group showed significant difference in oxidative stress by increasing SOD and GSH and decreasing LPO and NO activity on day 21.The treatment did not show statistically significant difference of cholesterol,and triglycerides level on day 21.Conclusion:The study showed anti-hyperglycemic and anti-oxidative properties of methanolic extract of B.juncea.展开更多
基金supported by the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Ministry of Education(No.2019R1A6C1010042)the financial support from the National Research Foundation of Korea(NRF)(2022R1A2C2010686,2022R1A4A3033528,2021R1C1C2010726)。
文摘Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product.This composite comprises Ru nanoclusters supported on the CuS nanostructure,achieved through simple pulsed laser irradiation in liquid approach.The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity,exhibiting a negligible working potential of 0.28 V(vs.RHE)for the anodic sulfion oxidation reaction(SOR)and a minimal overpotential of 182 m V for cathodic hydrogen evolution reaction(HER)to achieve 10 mA cm^(-2)of current density.Moreover,the Cu S/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions.Remarkably,in a two-electrode electrolyzer system utilizing Cu S/Ru-30 as both the anode and cathode,the SOR+HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm^(-2),which is considerably lesser compared to the OER+HER coupled water electrolysis(1.85 V).The experimental results and density function theory(DFT)calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field,greatly enhancing electron transfer efficiency.This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates.This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.
基金supported by the National Natural Science Foundation of China,National Key Research and Development Project (No.2016YFF0204402)the Program for Changjiang Scholars and Innovative Research Team in the University+1 种基金the Fundamental Research Funds for the Central Universitiesthe longterm subsidy mechanism from the Ministry of Finance and the Ministry of Education of PRC
文摘Defect engineering,especially oxygen vacancies(O-vacancies) introduction into metal oxide materials has been proved to be an effective strategy to manipulate their surface electron exchange processes.However,quantitative investigation of O-vacancies on CO2 electroreduction still remains rather ambiguous.Herein,a series of nanoporous tin oxide(SnOx) materials have been prepared by thermal treatment at various temperatures and reaction conditions.The annealing temperature dependent Ovacancies property of the SnOx was revealed and attributed to the balance tunning of the desorption of oxygen species and the continous oxidation of SnOx.The as-prepared nanoporous SnOx with 300℃treatment was found to be highest O-vacant material and showed an impressive CO2 RR activity and selectivity towards the conversion of CO2 into formic acid(up to 88.6%),and superior HCOOH incomplete current density to other samples.The ideal performance of the O-vacancies rich SnOx-300 material can be ascribed to the high delocalized electron density inducing much enhanced adsorption of CO2 with O binding and benefiting the subsequent reduction with high selectively forming of formic acid.
基金fully supported by the 2017 Yeungnam University Research Grant
文摘Polysaccharide-based bionanocomposite hydrogels with functional nanomaterials were used in biomed- ical applications. Self-organization of xanthan gum and chitosan in the presence of iron oxide magnetic nanoparticles (Fe304 MNPs) allowed us to form magnetically responsive polyelectrolyte complex hydro- gels (MPECHs) via insitu ionic complexation using D-(+)-glucuronic acid ^-lactone as a green acidifying agent. Characterization confirmed the successful formation of (and structural interactions within) the MPECH and good porous structure. The rheological behavior and compressive properties of the PECH and MPECH were measured. The results indicated that the incorporation of Fe304 MNPs into the PECH greatly improved mechanical properties and storage modulus (G'). In vitro cell culture of NIH3T3 fibroblasts on MPECHs showed improvements in cell proliferation and adhesion in an external magnetic field relative to the pristine PECH. The results showed that the newly developed MPECH could potentially be used as a magnetically stimulated system in tissue engineering applications.
文摘A precise understanding of the redox chemistry of Nm-Mn+(like N4-Fe^(2+))systems is essential for fundamental studies and rational design of Nm-Mn+-based electrocatalysts for the oxygen reduction reaction(ORR).Herein,three different iron phthalocyanines(FePcs)adsorbed on carbon nanotubes((NH2)4FePc@CNTs,(t-Bu)4FePc@CNTs,and FePc@CNTs)were evaluated to demonstrate the effect of the electron donating power of the substituents on the Fe^(3+)/Fe^(2+)redox potential of FePc@CNTs and the role of these composites as ORR mediators in alkaline media.The Fe^(3+)/Fe^(2+)redox potential of the FePcs was found to shift towards the cathodic region upon substitution with electron-donating groups.This up-field shift in the eg-orbital leads to a lower overlap between the onset potential of the Fe^(3+)/Fe^(2+)redox couple and that of the ORR,and thus,the ORR activity decreased in the following order based on the substitution of FePc:-H>-t-Bu>-NH2.
文摘The main objective of the present investigation is to study the vibration of visco-elastic parallelogram plate whose thickness varies parabolically. It is assumed that the plate is clamped on all the four edges and that the thickness varies parabolically in one direction i.e. along length of the plate. Rayleigh-Ritz technique has been used to determine the frequency equation. A two terms deflection function has been used as a solution. For visco-elastic, the basic elastic and viscous elements are combined. We have taken Kelvin model for visco-elasticity that is the combination of the elastic and viscous elements in parallel. Here the elastic element means the spring and the viscous element means the dashpot. The assumption of small deflection and linear visco-elastic properties of “Kelvin” type are taken. We have calculated time period and deflection at various points for different values of skew angles, aspect ratio and taper constant, for the first two modes of vibration. Results are supported by tables. Alloy “Duralumin” is considered for all the material constants used in numerical
基金supported by the Basic Science Research Program through partly the National Research Foundation of Korea(NRF)and BK21 PLUS4 funded by the Ministry of Education(2017R1D1A3B03031732)Also,This paper was partly supported by Korea Institute for Advancement of Technology(KIAT)grant funded by the Korea Government(MOTIE)(P0002092,The Competency Development Program for Industry Specialist).
文摘The use of nanofillers with high surface area and extreme purity in polymer composite is an effective strategy to obtain high performance polymeric nanocomposites.Therefore,the effect of nanofillers such as carbon nanotubes(CNT),titanium dioxide(TiO_(2)),and their hybrid on rubber-based composites was studied.In this study,rubber nanocomposites were fabricated by using room temperature vulcanized(RTV)silicone rubber matrix and nanofillers(i.e.CNT,TiO_(2),and CNT-TiO_(2))through solution casting method.Here,the purity and surface area of CNT(purity:>96%and BET surface area:300 m2/g)and TiO_(2)(purity:>98%and BET surface area:165 m2/g)were estimated by field emission scanning electron microscopy/energy dispersive X-ray(FESEM-EDX)and adsorption isotherms.The mechanical properties of the rubber nanocomposites were enhanced by incorporating nanofillers.The compressive modulus was 2.18 MPa for unfilled composites and increased to 6.8 MPa(CNT),3.95 MPa(CNT-TiO_(2)),and 2.44 MPa(TiO_(2))at 5 phr,respectively.Similarly,the tensile strength was 0.54 MPa for unfilled composites and increased to 1.37 MPa(CNT),1.33 MPa(CNT-TiO_(2))and 0.61 MPa(TiO_(2))at 5 phr,respectively.Further,the actuation displacement was improved with increasing input voltage and it was 2 mm for CNT,1.6 mm for CNT-TiO_(2) hybrid and 0.5 mm for TiO_(2) at 10 kV.Moreover,a series of experiments show the potential application in piezoelectric actuation.
文摘Objective:To explore natural compounds as potential inhibitors against main protease(Mpro)of SARS-CoV-2.Methods:In the current study,systematic molecular docking analysis was conducted using AutoDock 4.2 to determine the binding affinities and interactions between natural compounds and Mpro.Selected natural compounds were further validated using a combination of molecular dynamic(MD)simulations and molecular mechanic Poisson-Boltzmann surface area(MM/PBSA)free energy c alculation s.Results:Out of twenty natural compounds,four natural metabolites namely,amentoflavone,guggulsterone,puerarin,and piperine were found to have strong interaction with Mpro of SARS-CoV-2 based on docking analysis.During MD simulations,all four natural compounds bound to Mpro at 50 ns and MM/G/P/BSA free energy calculations showed that all four shortlisted ligands had stable and favorable energies with strong binding to Mpro protein.Conclusions:Guggulsterone is a potential inhibitor of COVID-19 main protease Mpro.Further in vitro and pre-clinical studies are needed.
基金National Natural Science Foundation of China,Grant/Award Number:22071137Key Projects of China National Key R&D Plan,Grant/Award Number:2018YFE0118200+1 种基金Key Projects of Shandong Key R&D plan,Grant/Award Number:2019JZZY010506Taishan Scholar Foundation,Grant/Award Number:tspd20210308。
文摘Design of supportive atomic sites with a controllably adjusted coordinating environment is essential to advancing the reduction of CO_(2) to value-added fuels and chemicals and to achieving carbon neutralization.Herein,atomic Ni(Zn)sites that are uniquely coordinated with ternary Zn(Ni)/N/O ligands were successfully decorated on formamide-derived porous carbon nanomaterials,possibly forming an atomic structure of Ni(N_(2)O_(1))-Zn(N_(2)O_(1)),as studied by combining X-ray photoelectron spectroscopy and X-ray absorption spectroscopy.With the mediation of additional O coordination,the Ni-Zn dual site induces significantly decreased desorption of molecular CO.The NiZn-NC decorated with rich Ni(N_(2)O_(1))-Zn(N_(2)O_(1))sites remarkably gained>97%CO Faraday efficiency over a wide potential range of -0.8 to -1.1 V(relative to reversible hydrogen electrode).Density functional theory computations suggest that the N/O dual coordination effectively modulates the electronic structure of the Ni-Zn duplex and optimizes the adsorption and conversion properties of CO_(2) and subsequent intermediates.Different from the conventional pathway of using Ni as the active site in the Ni-Zn duplex,it is found that the Ni-neighboring Zn sites in the Ni(N_(2)O_(1))-Zn(N_(2)O_(1))coordination showed much lower energy barriers of the CO_(2) protonation step and the subsequent dehydroxylation step.
文摘Melanoma is a perfidious form of skin cancer.The study offers a hybrid framework for the automatic classification of melanoma.An Auto-matic Melanoma Detection System(AMDS)is used for identifying melanoma from the infected area of the skin image using image processing techniques.A larger number of pre-existing automatic melanoma detection systems are either commercial or their accuracy can be further improved.The research problem is to identify the best preprocessing technique,feature extractor,and classifier for melanoma detection using publically available MED-NODE data set.AMDS goes through four stages.The preprocessing stage is for noise removal;the segmentation stage is for extracting lesions from infected skin images;the feature extraction stage is for determining the features like asymmetry,border,and color,and the classification stage is to classify the lesion as benign or melanoma.The infected input image for the AMDS may contain impurities such as noise,illumination,artifacts,and hairs.In the proposed methodology an algorithm LePrePro is proposed for the prepro-cessing stage for denoising and brightness cum contrast normalization and another algorithm LeFET is proposed for extending the feature vector space in the feature extraction stage using a hybrid approach.In the study,a novel approach has been proposed in which different classifiers,feature extractions,and data preprocessing steps of the AMDS are compared.In a conclusion,this comparison revealed that on experimentation using Med-Node and ISIC 2017 Dataset,the best results included Gaussian blur as the best data preprocessing step,Extended feature vector which is the combination of Hue Saturation Value(HSV),and Local Binary Pattern(LBP)was the best feature extraction method,and the ensemble bagged tree was the best classification technique on the Med-Node data sets with 99%Area Under the Receiver Operating Characteristic Curve(AUC),93.52%accuracy,90.82%sensitivity,and 98.36%specificity in the proposed automatic melanoma detection system.
文摘Environment monitoring has become a necessity because of global warming and climate change. All across the globe researchers are trying to monitor the environmental parameters of temperature, humidity and pollutants gases mere precisely in real time. Sensing system using sensor arrays has been developed to monitor indoor environment, however, these systems are costly and have not gained wide acceptance. Precise monitoring of building environment has a huge potential in terms of energy savings. In this paper, an effort has been made to develop a 4-channel energy efficient and low cost data logger for indoor environment. The Data logger is proposed to be developed with the use of PIC 18F4458. Real Time Clock and EEPROM are interfaced for sampled data with the instance of sampling time and month/date/year;these sampled data will be stored in the EEPROM to the note pad tabular form with the help of graphical user interface (GUI).
基金supported by the National Natural Science Foundation of China(NSFC,22071137).
文摘Despite the fact that low-dimensional carbons(LDCs,1D/2D)materials are very interesting due to their intriguing electrical properties,we still attempt to enrich them by high N-content in order to enjoy their electro-applications.We here report a template-free synthesis of 1D/2D LDC with high N content(>40 at%)and tunable aspect ratios from molecular formamide(FA).The 1D/2D LDC is in polyaminoimidazole as confirmed by pair distribution function analysis,and 1D growth mode can be altered to 2D by simply adding a 2D-guiding molecule of melamine.Electrochemical properties of the LDC can befinely tuned by adjusting the solvothermal temperature and melamine dosage.It is revealed that the optimal 2D LDC delivers superior O2-to-H_(2)O_(2) yield(687.2 mmol⋅g^(-1)⋅h^(-1))and Faradic efficiency(87.5%).Considering the heavy N content and high adjustability of aspect ratio,the FAderived LDCs potentially open new synthesis routes for structural carbon materials for broad electrochemical applications.
基金supported by intramural funding from the National Institute of Cancer Prevention and Research,Indian Council of Medical Research(No.NICPR/Anuj/intramural/2021/1).
文摘Background:Betel nut/areca nut/Areca catechu is one of the most commonly used psychoactive substance,and is also a major preventable cause of cancer.Unlike other psychoactive substances,such as nicotine,the mechanisms underlying addiction to areca nuts and related oncogenesis remain elusive.Recent reports suggest a possible overlap in the mechanisms of action of nicotine and areca nuts in the human body.Thus,this study aimed to investigate the interactome of human proteins associated with areca nut exposure and the intricate similarities and differences in the effects of the two psychoactive substances on humans.Methods:A list of proteins associated with areca nut use was obtained from the available literature using terms from Medical Subject Headings(MeSH).Protein-protein interaction(PPI)networks and functional enrichment were analyzed.The results obtained for both psychoactive substances were compared.Results:Given the limited number of common proteins(36/226,16%)in the two sets,a substantial overlap(612/1176 nodes,52%)was observed in the PPI networks,as well as in Gene Ontology.Areca nuts mainly affect signaling pathways through three hub proteins(alpha serine/threonine-protein kinase,tumor protein 53,and interleukin-6),which are common to both psychoactive substances,as well as two unique hub proteins(epidermal growth factor receptor and master regulator of cell cycle entry and proliferative metabolism).Areca nut-related proteins are associated with unique pathways,such as extracellular matrix organization,lipid storage,and metabolism,which are not found in nicotine-associated proteins.Conclusions:Areca nuts affect regulatory mechanisms,leading to systemic toxicity and oncogenesis.Areca nuts also affect unique pathways that can be studied as potential markers of exposure,as well as targets for anticancer therapeutic agents.
基金funding this work through large group Research Project under grant number RGP2/172/44.
文摘Efficient electrocatalytic rupture of energy-rich molecules(H_(2)and O_(2))is a green approach for gener-ating clean energy for modern societies.In this context,porphyry-type molecular electrocatalysts act intelligently toward oxygen reduction reaction(ORR),a fundamental process in fuel cells,due to their redox-rich chemistry,which involves core metal ions and macrocyclic ligands.The concerned scientific community has tried many times to correlate the ORR intermediates with their formation kinetics and simplify the associated multi H+/e-stages during the ORR process,constructing several volcano plots be-tween catalytic Tafel data,turnover frequencies,and overpotentials for many electrocatalysts.Despite the fact that many review articles on molecular electrocatalysts for ORR have been published,understanding the strategic implications and molecular catalyst intelligence towards homogenous ORR has been poorly explored.This review examined the relationships between volcano plots of current vs.thermodynamic parameters and the Sabatier principle in order to explain the intelligence of molecular electrocatalysts and approaches for their creation,as well as the difficulties and potential prospects of molecular electro-catalysts.These facts distinguish this review from previously published articles and will pique the scien-tific community’s interest in avoiding trial-and-error procedures for catalyst creation while also allowing for more exact evaluations of the molecular catalyst’s performance.
基金supported by the Research Fund for International Scientists(RFIS-Grant numbers:52150410410)National Natural Science Foundation of Chinathe Deanship of Scientific Research and Graduate Studies at King Khalid University for funding this research work through Large Research Project under the grant number RGP2/121/1445.
文摘Inspired by molecular catalysts,researchers developed atomically precise nitrogen-coordinated single or dual metal sites imbedded in graphitized carbon(M-N-C)to fully utilize metallic sites for 02activation.These catalysts performed remarkably well in the electrocatalytic oxygen reduction reaction(ORR)due to their distinct coordination and electrical structures,Nonetheless,their maximum efficacy in practical applications has yet to be achieved.This agenda identifies tailoring the coordination environment,spin states,intersite distance,and metal-metal interaction as innovative approaches to regulate the ORR performance of these catalysts.However,it is necessary to undertake a precise assessment of these methodologies and the knowledge obtained to be implemented in the design of future M-N-C catalysts for ORR.Therefore,this review aims to analyze recent progress in M-N-C ORR catalysts,emphasizing their innovative engineering with aspects such as alteration in intersite distance,metal-metal interaction,coordination environment,and spin states.Additionally,we critically discuss how to logically monitor the atomic structure,local coordination,spin,and electronic states of M-N-C catalysts to modulate their ORR activity.We have also highlighted the challenges associated with M-N-C catalysts and proposed suggestions for their future design and fabrication.
基金This work was financially supported by the National Natural Science Foundation of China(No.21701101)the National Key Research and Development Project(Nos.2018YFE0118200,2016YFF0204402)+5 种基金the Fundamental Research Funds for the Central Universities(No.18CX06063A)the Long-Term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of China,the Shandong Key Research and Development Project(No.2019JZZY010506)the Shandong Scientific Research Awards Foundation for Outstanding Young Scientists(No.ZR2018JL010)the Shandong Joint Fund of Outstanding Young Talents(No.ZR2017BB018)the Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(No.2017RCJJ059)the Program for Tsingtao Al-ion Power and Energy-Storage Battery Research Team in the University(No.17-2-1-1-zhc).
文摘Carbon materials featuring hierarchical pores and atomically dispersed metal sites are promising catalysts for energy storage and conversion applications.Herein,we developed a facile strategy to construct functional carbon materials with a fluffy peony-like structure and dense binary FeCo-Nx active sites(termed as f-FeCo-CNT).By regulating the metal content in precursors,a three-dimensional(3D)interconnected conductive carbon nanotubes network was in-situ formed throughout the atomically dispersed FeCo-NC matrix during pyrolysis.Taking advantage of rich pore hierarchy and co-existence of highly active FeCo-Nx sites and beneficial FeCo alloy nanoparticles,the f-FeCo-CNT material exhibited excellent bifunctional performance towards oxygen reduction reaction/oxygen evolution reactions(ORR/OER)with respect to the atomically dispersed FeCo-NC(SA-f-FeCo-NC)and commercial Pt/C+Ru02 mixture,surpassing the SA-f-FeCo-NC with a 20 mV higher ORR half-wave potential and a 100 mV lower OER overpotential(at 10.0 mA/cm^2).Remarkably,the f-FeCo-CNT-assembled Zn-air battery(ZAB)possessed a maximum specific power of 195.8 mW/cm^2,excellent rate capability,and very good cycling stability at large current density of 20.0 mA/cm^2.This work provides a facile and feasible synthetic strategy of constructing low-cost cathode materials with excellent comprehensive ZAB performance.
基金supported by the National Natural Science Foundation of China(NSFC)the National Key Research and Development Project of China(2016YFF0204402)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in the University(IRT1205)the Fundamental Research Funds for the Central Universities,the Long-Term Subsidy Mechanism from the Ministry of Finance and the Ministry of Education of PRC
文摘In this article,we review the advancement in nanoseparation and concomitant purification of nanoparticles(NPs) by using density gradient ultracentrifugation technique(DGUC) and demonstrated by taking several typical examples.Study emphasizes the conceptual advances in classification,mechanism of DGUC and synthesis-structure-property relationships of NPs to provide the significant clue for the further synthesis optimization.Separation,concentration,and purification of NPs by DGUC can be achieved at the same time by introducing the water/oil interfaces into the separation chamber.We can develop an efficient method ‘‘lab in a tube" by introducing a reaction zone or an assembly zone in the gradient to find the surface reaction and assembly mechanism of NPs since the reaction time can be precisely controlled and the chemical environment change can be extremely fast.Finally,to achieve the best separation parameters for the colloidal systems,we gave the mathematical descriptions and computational optimized models as a new direction for making practicable and predictable DGUC separation method.Thus,it can be helpful for an efficient separation as well as for the synthesis optimization,assembly and surface reactions as a potential cornerstone for the future development in the nanotechnology and this review can be served as a plethora of advanced notes on the DGUC separation method.
文摘During disease outbreak,it has been observed that information about the disease prevalence induces the individuafs behavioral changes.This information is usually assumed to be generated by the density of infective individuals and active mass media.The delay in reporting of these infective individuals may have its impact on generated information.Hence,to study the impact of delay on information generation,and therefore on the disease dynamics,a delay differential equation model is proposed and analyzed.The dynamics of information with delay effect is also modeled by a separate rate equation.Model analysis is performed and a unique infected equilibrium is obtained when the basic reproduction number(R0)is greater than one,whereas the disease free equilibrium always exists.When R0<1,the disease free equilibrium is found to be locally stable independent of delay effect.The unique infected equilibrium is found to be locally stable till delay reaches a threshold value.The global stability of the unique infected equilibrium is also established under some parametric conditions by constructing a suitable Lyapunov function.The occurrence of Hopf bifurcation is observed when the delay in information crosses the threshold value.Analytically,the direction and stability of bifurcating periodic solutions is established.Further,we observed the occurrence of Hopf-Hopf bifurcation at two different delays.At first delay threshold,the endemic equilibrium loses its st ability and produces periodic oscillations via Hopf bifurcation.It further regains its stability at second delay threshold via another Hopf bifurcation.Hence,the delay effect on information shows possibility of stability switches.Numerical experiments are carried out to support the obtained analytical results.Our study infers that the disease will show persistent oscillations if there is a significant time lag in reporting of infective after the disease outbreak.Thus,the delay in dissemination of information shows rich and complex dynamics in the model and provides important insights.We also observe numerically that the saturation in information plays a significant role on stability of infected equilibrium in presence of delay.
基金Banaras Hindu University(BHU)for providing grant to carry out study.
文摘Objective:To study the bioactivity of methanolic extract of Brassica juncea on animal model of diabetes mellitus along with its effect on diabetic and metabolic parameters.Methods:Diabetes mellitus was induced in rats by injecting streptozotocin(60 mg/kg)intraperitonealy.Blood glucose was measured on day 3 by GOD-POD method to confirm the diabetes mellitus.Rats having fasting blood glucose>250 mg/d L were further selected for study and they were divided into four groups,control,control+streptozotocin,streptozotocin+metformin(75 mg/kg)and streptozotocin+extract of B.juncea(450 mg/kg).Each group consisted of six rats of either sex.Metformin and experimental extract were administered for 21 d.Triglyceride,cholesterol level were measured on day 21 by commercially available kit.Blood glucose was measured on days 7 and 21.Anti-oxidant potential was assessed by estimating extent of lipid peroxidation(LPO)by malondialdehyde(MDA),nitric oxide(NO),superoxide dismutase(SOD)and glutathione(GSH)in liver,kidney,pancreas,muscle tissues on day 21.Unpaired and paired student’s t-test was applied for statistical analysis.Results:The extract of B.juncea showed significant decrease in blood glucose level on day 21.The treatment group showed significant difference in oxidative stress by increasing SOD and GSH and decreasing LPO and NO activity on day 21.The treatment did not show statistically significant difference of cholesterol,and triglycerides level on day 21.Conclusion:The study showed anti-hyperglycemic and anti-oxidative properties of methanolic extract of B.juncea.