Trust-based Intelligent Scheme for Mitigating Black Hole Attacks in IoT

Internet of Things(IoT)networks are characterized by a multitude of wireless,interconnected devices that can dynamically join or exit the network without centralized administration or fixed infrastructure for routing.While multipath routing in IoT networks can improve data transmission reliability and load balancing by establishing multiple paths between source and destination nodes,these networks are susceptible to security threats due to their wireless nature.Traditional security solutions developed for conventional networks are often ill-suited to the unique challenges posed by IoT environments.In response to these challenges,this paper proposes the integration of the Ad hoc On-demand Multipath Distance Vector(AOMDV)routing protocol with a trust model to enhance network performance.Key findings from this research demonstrate the successful fusion of AOMDV with a trust model,resulting in tangible improvements in network performance.The assessment of trustworthiness bolsters both security and routing capabilities in IoT networks.The trust model plays a crucial role in mitigating black hole attacks in IoT networks by evaluating the trustworthiness of nodes and helping in the identification and avoidance of malicious nodes that may act as black holes.Simulation results validate the efficacy of the proposed trust-based routing mechanism in achieving its objectives.Trust plays a pivotal role in decision-making and in the creation of secure distribution systems.By assessing the trustworthiness of nodes,both network security and routing efficiency can be enhanced.The effectiveness of the proposed trust-based routing mechanism is scrutinized through simulations,offering insights into its potential advantages in terms of improved network security and routing performance in the context of the IoT.

Larvicidal and repellent activity of medicinal plant extracts from Eastern Ghats of South India against malaria and filariasis vectors

Objective:To evaluate the larvicidal and repellent activities of ethyl acetate and methanol extracts of Acacia concinna（A.concinna）,Cassia siamea（C.siamea）.Conundrum sativum（C. sativum）,Cuminum cyminum（C.cyminum）,Lantana camma（L.camara）,Nelumbo nucifera （N.nucifera） Phyllanlhus amarus（P.amarus）.Piper nigrum（P.nigrum） and Trachyspermum ammi（T.ammi） against Anopheles stephensi（An.stephensi） and Culex quinquefasciatus（Cx. quinquefasciatus）.Methods:The larvicidal activity of medicinal plant extracts were tested against earl) fourth-instar larvae of malaria and filariasis vectors.The mortality was observed 24 h and 48 h after treatment,data were subjected to probit analysis to determine the lethal concentrations(LC50 and LC90) to kill 50 and 90 per cent of the treated larvae of the tested species. The repellent efficacy was determined against two mosquito species at five concentrations（31.25. 62.50.125.00.250.00,and 500.00 ppm） under the laboratory conditions.Results:All plant extracts showed moderate effects after 24 h and 48 h of exposure;however,the highest activity was observed after 24 h in the leaf methanol extract ol N.nucifera.seed ethyl acetate and methanol extract of P.nigrum against the larvae of An.Stephensi(LC50 = 34.76.24.54 and 30.20 ppm) and against Cx.quinquefasciatus(LC50= 37.49.43.94 and 57.39 ppm),respectively.The toxic effect of leaf methanol extract of C.siamea,seed methanol extract of C.cyminum,leaf ethyl acetate extract of N.nucifera.leaf ethyl acetate and methanol extract of P.amarus and seed methanol extract of T.ammi were showed 100%mortality against An.stephensi and Cx.quinquefasciatus alter 48 h exposer.The maximum repellent activity was observed at 500 ppm in methanol extracts of N. nucifera.ethyl acetate and methanol extract of P.nigrum and methanol extract of T.ammi and the mean complete protection time ranged from 30 to 150 min with the different extracts tested. Conclusions:These results suggest that the leaf and seed extracts of C.siamea.N.nucifera.P. amarus.P.nigrum and T.ammi have the potential to be used as an ideal ecofriendly approach for the control of the An.stephensi and Cx.quinquefasciatus.

Antihyperglycemic and antioxidant effects of Solanum xanthocarpum leaves(field grown & in vitro raised) extracts on alloxan induced diabetic rats

Objective:To investigate antidiabetic efficacy of the extract of field grown and in vitro raised leaves of Solanum xanthocarpum(S.xanthocarpum) against alloxan induced diabetic rats. Methods:The antidiabetic activity of the crude methanol extracts of the field grown and in vitro raised leaves of S.xanthocarpum at different concentrations(100-200 mg/kg bw) was tested against alloxan induced diabetic rats.The antidiabetic efficacy was validated through various biochemical parameters and the antioxidant effect was also determined.The phytochemical analyses of field grown S.xanthocarpum and in vitro rasied 5.xanthocarpum leaves were done by estimating their chlorophyll,carotenoids,total sugar,protein,amino acid and minerals contents. Results:The results revealed that the methanol extracts of both the leaves(field grown and in vitro raised) of S.xanthocarpum was efficient anti hyperglycemic agents at a concentration of 200 mg/kg bw and posses potent antioxidant activity.However,the extracts of in vitro rasied S.xanthocarpum raised leaves exhibit higher efficacy than the field grown leaves in all tested concentrations.Proximal composition and mineral analysis of S.xanthocarpum revealed higher concentration of contents in in vitro rasied S.xanthocarpum than field grown S.xanthocarpum. Conclusions:From the results it can be concluded that the leaves extracts of S.xanthocarpum can be a potential candidate in treating the hyperglycemic conditions and suits to be an agent to reduce oxidative stress.

Comparison of TiAlN, AlCrN, and AlCrN/TiAlN coatings for cutting-tool applications

Monolayer and bilayer coatings of TiAlN, AlCrN, and AlCrN/TiAlN were deposited onto tungsten carbide inserts using the plasma enhanced physical vapor deposition process. The microstructures of the coatings were characterized using scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The SEM micrographs revealed that the AlrN and AlCrN/TiAlN coatings were uniform and highly dense and contained only a limited number of microvoids. The TiAIN coating was non-uniform and highly porous and contained more micro droplets. The hardness and scratch resistance of the specimens were measured using a nanoindentation tester and scratch tester, respectively. Different phases formed in the coatings were analyzed by X-ray diffraction （XRD）. The AlCrN/TiAlN coating exhibited a higher hardness （32.75 GPa）, a higher Young＇s modulus （561.97 GPa）, and superior scratch resistance （LcN = 46 N） compared to conventional coatings such as TiAlN, A1CrN, and TiN.

二氧化硫脲:一锅合成吡喃并[4,3-b] 吡喃类化合物的高效可重复使用有机催化剂（英文）

A series of pyrano[4,3‐b]pyran derivatives have been synthesized in excellent yields by the reaction of aromatic aldehydes with malononitrile or cyanoacetate and 4‐hydroxy‐6‐methylpyran‐2‐one in water at 80 °C, with the transformation being catalyzed by an aqueous solution of thiourea dioxide(TUD). Upon completion of the reaction, the product was isolated by filtration or extraction and the remaining aqueous TUD solution could be reused several times without any discernible impact on its catalytic activity. This procedure offers several advantages over existing procedures, including high yields, operational simplicity, the use of a non‐toxic catalyst and solvent, short reaction time and minimum pollution of the environment, making it a useful and attractive process for the preparation of pyrano[4,3‐b]pyran derivatives.

Efficacy of larvicidal and pupicidal activity of Catharanthus roseus aqueous and solvent extracts against Anopheles stephensi Liston and Culex quinquefasciatus Say (Diptera: Culicidae)

Objective: To investigate the larvicidal and pupicidal activities of aqueous, ethyl acetate and methanol extracts of Catharanthus roseus ( C. roseus ) against malaria and filariasis vectors. Methods: The larvicidal and pupicidal activities of C. roseus leaf extracts were tested against the fourth instar larvae and pupae of Anopheles stephensi ( An. stephensi ) and Culex quinquefasciatus ( Cx. quinquefasciatus ). The mortality was observed after 24 and 48 h post the treatment. The data were subjected to probit analysis to determine the lethal concentrations (LC 50 and LC 90 ) at which 50% and 90% of the treated larvae or pupae of the tested species were killed. Results: The larval and pupal mortality were observed after 24 and 48 h of exposure of aqueous, ethyl acetate and methanol extracts of C. roseus ; no mortality was observed in the control group. The LC 50 values against the fourth-instar larvae of An. stephensi were 68.62 and 72.04 mg/mL for the aqueous extract, 82.47 mg/mL for the ethyl acetate extract, and 78.80 and 86.64 mg/mL for the methanol extract, while the aqueous, ethyl acetate and methanol extracts had LC 50 values of 85.21, 76.84 and 94.20 mg/mL against the fourth-instar larvae of Cx. quinquefasciatus . The aqueous, ethyl acetate and methanol extracts had LC 50 values of 118.08, 182.47 and 143.80 mg/mL against the pupae of An. stephensi and 146.20, 226.84 and 156.62 mg/mL against the pupae of Cx. quinquefasciatus , respectively. Conclusions: The aqueous and methanol extracts of C. roseus leaves had an excellent potential to control the malarial vector An. stephensi and filariasis vector Cx. quinquefasciatus .

Evaluation of larvicidal activity of medicinal plant extracts against three mosquito vectors

Objective:To evaluate the mosquito larvicidal activity of plant extracts.Methods:The hexane,chloroform,ethyl acetate,acetone,and methanol leaf,flower and seed extracts of Abrus precatorius（A.precatorius）,Croton bonplandianum（C.bonplandianum）,Cynodon dactylon （C.dactylon）,Musa paradisiaca（M.paradisiaca） and Syzygium aromaticum（S.aromaticum） were tested against fourth instar larvae of Anopheles vagus（An.vagus）,Armigeres subalbatus （Ar.subalbatus） and Culex vishnui（Cx.vishnui）.Results:The highest larval mortality was found in seed ethyl acetate extracts of A.precatorius and leaf extracts of C.bonplandianum, flower chloroform and methanol extracts of M.paradisiaca,and flower bud hexane extract of S. aromaticum against An.vagus with LC50 values of 19.31,39.96,35.18,79.90 and 85.90μg/mL;leaf ethyl acetate and methanol extracts of C.dactylon,flower methanol extract of M.paradisiaca, flower bud methanol extract of S.aromaticum against Ar.subalbatus with LC50 values of 21.67, 32.62,48.90 and 78.28μg/mL,and seed methanol of A.precatorius,flower methanol extract of M.paradisiaca,flower bud hexane extract of S.aromaticum against Cx.vishnui with LC50 values of 136.84,103.36 and 149.56μg/mL,respectively.Conclusions:These results suggest that the effective plant crude extracts have the potential to be used as an ideal ecofriendly approach for the control of disease vectors.This study provides the first report on the larvicidal activity of crude solvent extracts of different mosquitoes.

Larvicidal activity of green synthesized silver nanoparticles using bark aqueous extract of Ficus racemosa against Culex quinquefasciatus and Culex gelidus

Objective:To investigate the larvicidal activity of synthesized silver nanoparticles（Ag NPs） utilizing aqueous bark extract of Ficus racemosa（F.racemosa） was tested against fourth instar larvae of filariasis vector,Culex quinquefasciatus（Cx.quinquefasciatus） and japanese encephalitis vectors,Culex gelidus（Cx.gelidus）.Methods:The synthesized Ag NPs was characterized by UV-vis spectrum,X-ray diffraction（XRD）,Scanning electron microscopy（SEM） and Fourier transform infrared（FTIR）.The larvicidal activities were assessed for 24 h against the larvae of Cx.quinquefasciatus and Cx.gelidus with varying concentrations of aqueous bark extract off.racemosa and synthesized Ag NPs.LC50 and r2 values were calculated.Results:The maximum efficacy was observed in crude aqueous extract of F.racemosa against the larvae of Cx.quinquefasciatus and Cx.gelidus(LC50=67.72 and 63.70 mg/L;r2=0.995 and 0.985) and the synthesized Ag NPs(LC50=12.00 and 11.21 mg/L;r2=0.997 and 0.990).respectively.Synthesized Ag NPs showed the XRD peaks at 2θvalues of 27.61,29.60,35.48,43.48 and 79.68 were identified as （210）,（121）,（220）,（200） and（311） reflections,respectively.The FTIR spectra of Ag NPs exhibited prominent peaks at 3 425,2 878,1 627 and 1 382 in the region 500-3 000 cm-1.The peaks correspond to the presence of a stretching vibration of（NH） C=O group.SEM analysis showed shape in cylindrical,uniform and rod with the average size of 250.60 nm.Conclusions:The biosynthesis of silver nanoparticles using bark aqueous extract of F.racemosa and its larvicidal activity against the larvae of disease spreading vectors.The maximum larvicidal efficacy was observed in the synthesized Ag NPs.

Green synthesis of titanium dioxide nanoparticles using Psidium guajava extract and its antibacterial and antioxidant properties

Objective:To determine the efficacies of antibacterial and antioxidant activities of aqueous leaf extract of Psidium guajava mediated biosynthesis of titanium dioxide nanoparticles(TiO_2,NPs).Methods:Synthesized TiO_2 NPs were tested by disc diffusion method against against human pathogenic bacteria.The total antioxidant activity and phenolic content(Folin—Ciocalteau method) of synthesized TiO_2 NTs and aqueous plant extract were determined.The scavenging radicals were estimated hv DPPH method.The synthesized TiO_2 NPs were characterized by XRD,FTIR.FESEM and EDX,Results:FTIR spectra of synthesized TiO_2 NPs exhibited prominent peaks at 3410 cm^(-1)(alkynes),1 578 cm^(-1).1 451 cm^(-1)(alkanes),and 1 123 cm^(-1)(C-O absorption).The morphological characterization of synthesized TiO_2 NPs was analysed by FESEM which showed spherical shape and clusters with an average size of 32.58 nm.The maximum zone of inhibition was observed in the synthesized TiO_2 NPs(20 μg/mL) against Staphylococcus aureus(25 mm) and Escherichia coli(23 mm).The synthesized TiO_2 NPs showed more antibacterial activity than the standard antibiotic disk,tetracycline which drastically reduces the chances for the development of antibiotics resistance of bacterial species.The plant aqueous extract and synthesized TiO_2NPs were found to possess maximum antioxidant activity when compared with ascorbic acid.The content of phenolic compounds(mg/g) in Leaf aqueous extract and synthesized TiO_2 NPs were found to be 85.4 and 18.3 mgTA/g,respectively.Conclusions:Green synthesized TiO_2 NPs provides a promising approach can satisfy the requirement of large-scale industrial production hearing the advantage of low—cost,eco—friendly and reproducible.

Hepatoprotective potential of petroleum ether leaf extract of Crossandra infundibuliformis on CCl_4 induced liver toxicity in albino mice

Objective:To analyze the hepatoprotective effect of the Crossandra infundibuliformis.Methods: Hepatotoxicity was induced by carbon tetrachloride.Petroleum ether extract of dried leaves was administrated to mice for 7 days.The hepatoprotective effect of petroleum ether extract was evaluated by the assay of liver function biochemical parameters.Results:The result clearly indicates that petroleum ether extract showed significant hepatoprotection when compared with standard Silumarin.Conclusions:The petroleum ether extract of the leaves of Crossandra infundibuliformis possess significant acute hepatoprotective activity.Thus further investigation on this species would bring a promising drug for liver disorders.

Adult emergence inhibition and adulticidal activities of medicinal plant extracts against Anopheles stephensi Liston

Objective:To determine the adult emergence inhibition（EI） and adulticidal activities of hexane,chloroform,ethyl acetate,and acetone leaves extracts of Anisomeles malabarica（A. malabarica）,Euphorbia hirta（E,hirta）,Ocimum basilicum（0.basilicum）,Ricinus communis（R. communis）,Solanum trilobatum（S.trilobatum）,Tridax procumbens（T.procumbens） and seeds of Gloriosa superba（G.superba） against Anopheles stephensi（An,stephensi）.Methods:The EI and adulticidal trials were carried out according to World Health Organization（WHO） procedures with slight modifications.The extracts were diluted in dimethyl sulphoxide in order to prepare a serial dilution of test dosages（15.625,31.25,62.5,125,250,500 and 1 000μg/mL）.Five duplicate trials were carried out for every sample concentration,and for each trial a negative control was included and the mortality was determined after 24 h of exposure.Results:The highest EI activity was found in ethyl acetate extracts of A malabarica,chloroform extracts of O.basilicum, S.trilobatum,acetone of extract of R.communis,T.procumbens,and seed extract of G.superba with EI50 values 143.12,119.82.157.87,139.39,111.19,and 134.85μg/mL,and the effective adulticidal activity was observed in chloroform,acetone extracts of G.superba,T.procumbens,R. communis,S.trilobatum and ethyl acetate extract of 0.basilicum with LD50 values 120.17,108.77, 127.22,163.11,118.27,and 93.02μg/mL,respectively.Chi-square value was significant at P【0.05 level.Conclusions:These results should encourage further efforts to investigate the compounds that might possess good EI and adulticidal properties when isolated in pure form.

Larvicidal and adulticidal potential of medicinal plant extracts from south India against vectors

Objective:To determine the larvicidal and adulticidal activities of hexane,ethyl acetate and methanol extracts of Momordica charantia（M.charantia）,Moringa oleifera（M.oleifera）,Ocimum gratissimum（O.gratissimum）,Ocimum tenuiflorum（0.tenuiflorum）,Punica granalum（P. granatum） and Tribulus terrestris（T.terrestris） against Culex gelidus（Cx.gelidus） and Culex quinquefasciatus（Cx.quinquefasciatus）.Methods:Bioassay test was carried out by WHO method for determination of larvicidal and adulticidal activity against mosquitoes.Results:All plant extracts showed moderate larvicidal and adulticidal activities,however the effective larval mortality was found in the leaf ethyl acetate and methanol extract of O.gratissimum and bark methanol extract of M.oleifera against Cx.gelidus with LC50 values of 39.31.66.28,and 21.83μg/mL respectively,and methanol extract of 0.gratissimum,0.tenuiflorum and P.granatum against Cx.quinquefasciatus with LC50 values of 38.47.24.90 and 67.20μg/mL,respectively.The adult exposed for 1 h and mortality was recorded at 24 h recovery period.Above 90%- mortality was found in the ethyl acetate and methanol extract of all experimental plants at the concentrations of 500μg/mL.Conclusions:The present results suggest that the medicinal plant extracts provided an excellent potential for controlling Cx.gelidus and Cx.quinquefasciatus.

Inhibition of Fish Nodavirus by Gymnemagenol Extracted from Gymnema sylvestre

Viral nervous necrosis(VNN)has emerged to become a major problem in the culture of larval and juvenile marine fish worldwide.Bioactive phytochemicals isolated from commonly available medicinal plants are often screened for their efficacy in controlling fish viral diseases.Occurrence of newer viral strains and resistance to existing antiviral drugs are problems currently as-sociated with treatment of VNN,which necessitates looking for alternate sources for effective antiviral drugs.The aim of the present study was to screen antiviral potential of gymnemagenol(C30H50O4)previously extracted from leaves of Gymnema sylvestre.The fish nodavirus,grouper nervous necrosis virus(GNNV)in infected Sahul Indian Grouper Eye(SIGE)cell lines were used to study the antiviral activity of gymnemagenol under in vitro conditions.The susceptibility of the virus to gymnemagenol was confirmed by measuring the viral titre(TCID50 mL?1)in virus-infected SIGE cells every 24 h.Gymnemagenol at 20 μg mL?1 inhibited the prolifera-tion of GNNV to 53% at the end of the 6th d by inhibiting the proliferation of GNNV-infected SIGE cells.The viable SIGE cells were reduced to 47% as determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.The viral titre(TCID50 mL?1)was also reduced to log 2.8 at the end of the 7th d in gymnemagenol-treated SIGE cells after inoculated with GNNV when compared to untreated control SIGE cell viral titre(log 4.1).Based on our results it can be concluded that gymnemagenol could be used as an antiviral agent against GNNV infection.

Robust Hybrid Artificial Fish Swarm Simulated Annealing Optimization Algorithm for Secured Free Scale Networks against Malicious Attacks

Due to the recent proliferation of cyber-attacks,highly robust wireless sensor networks(WSN)become a critical issue as they survive node failures.Scale-free WSN is essential because they endure random attacks effectively.But they are susceptible to malicious attacks,which mainly targets particular significant nodes.Therefore,the robustness of the network becomes important for ensuring the network security.This paper presents a Robust Hybrid Artificial Fish Swarm Simulated Annealing Optimization(RHAFS-SA)Algorithm.It is introduced for improving the robust nature of free scale networks over malicious attacks(MA)with no change in degree distribution.The proposed RHAFS-SA is an enhanced version of the Improved Artificial Fish Swarm algorithm(IAFSA)by the simulated annealing(SA)algorithm.The proposed RHAFS-SA algorithm eliminates the IAFSA from unforeseen vibration and speeds up the convergence rate.For experimentation,free scale networks are produced by the Barabási–Albert(BA)model,and real-world networks are employed for testing the outcome on both synthetic-free scale and real-world networks.The experimental results exhibited that the RHAFS-SA model is superior to other models interms of diverse aspects.

Histopathological studies and oxidative stress of synthesized silver nanoparticles in Mozambique tilapia (Oreochromis mossambicus)

To evaluate the potential environmental effects of engineered nano metals,it is important to determine the adverse effects of various nanomaterials on aquatic species.Adult tilapia （Oreochromis mossambicus） were maintained in 10 L glass aquaria,and exposed to a graded series of synthesized silver nanoparticles （Ag-NPs） at 25,50 and 75 mg/L for eight days.The LC 50 value was 12.6 mg/L.Reduced activities of antioxidant enzymes and the contents of antioxidants were lowered in the gills and liver of fishes treated with AgNPs,which resulted in heavy accumulation of free radicals.Histopathological results imply that the balance between the oxidative and antioxidant system in the fish was broken down during Ag-NPs exposure.The principal concern related with the release of nanomaterials and their smaller particle may change the materials transport and potential toxicity to aquatic organisms compared to larger particles.

Synthesis, Characterization, Thermal Stability and Antibacterial Activity of Coumarin Based Methacrylate Copolymers

Monomer of 7-methacryloyloxy-4-methylcoumarin （MAOMC） was synthesized and characterized by FTIR, 1H-NMR and 13C-NMR spectroscopy. Copolymers of MAOMC with butoxyethylmethacrylate （BOEMA） at different feed compositions were prepared by free radical solution polymerization at （70 ± 1） ℃ in ethylmethylketonc （EMK） using benzyl peroxide （BPO） as an initiator. The copolymers were characterized by FTIR and IH-NMR spectroscopy. Thermogravimetric analysis （TGA） and differential scanning calorimetry （DSC） of the copolymers showed moderate thermal stability and higher Tg values. Gel permeation chromatography （GPC） was used to find out the molecular weights of the different copolymers. Antibacterial activities of the copolymers were also investigated against the selected pathogenic bacteria＇s. The antibacterial activity of the copolymer increases as the MAOMC content increases in the copolymer. This shows that coumarin moiety plays a very important role in the antibacterial activity.