Embedding and Siamese deep neural network-based malware detection in Internet of Things

Purpose

A proper understanding of malware characteristics is necessary to protect massive data generated because of the advances in Internet of Things (IoT), big data and the cloud. Because of the encryption techniques used by the attackers, network security experts struggle to develop an efficient malware detection technique. Though few machine learning-based techniques are used by researchers for malware detection, large amounts of data must be processed and detection accuracy needs to be improved for efficient malware detection. Deep learning-based methods have gained significant momentum in recent years for the accurate detection of malware. The purpose of this paper is to create an efficient malware detection system for the IoT using Siamese deep neural networks.

Design/methodology/approach

In this work, a novel Siamese deep neural network system with an embedding vector is proposed. Siamese systems have generated significant interest because of their capacity to pick up a significant portion of the input. The proposed method is efficient in malware detection in the IoT because it learns from a few records to improve forecasts. The goal is to determine the evolution of malware similarity in emerging domains of technology.

Findings

The cloud platform is used to perform experiments on the Malimg data set. ResNet50 was pretrained as a component of the subsystem that established embedding. Each system reviews a set of input documents to determine whether they belong to the same family. The results of the experiments show that the proposed method outperforms existing techniques in terms of accuracy and efficiency.

Originality/value

The proposed work generates an embedding for each input. Each system examined a collection of data files to determine whether they belonged to the same family. Cosine proximity is also used to estimate the vector similarity in a high-dimensional area.

Molecular structure, vibrational, electronic and thermal properties of 4-vinylcyclohexene by quantum chemical calculations

The solid phase FT-IR and FT-Raman spectra of 4-vinylcyclohexene (abbreviated as 4-VCH) have been recorded in the region 4000-100cm(-1). The optimized molecular geometry and vibrational frequencies of the fundamental modes of 4-VCH have been precisely assigned and analyzed with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) method at 6-311++G(d,p) level basis set. The theoretical frequencies were properly scaled and compared with experimentally obtained FT-IR and FT-Raman spectra. Also, the effect due the substitution of vinyl group on the ring vibrational frequencies was analyzed and a detailed interpretation of the vibrational spectra of this compound has been made on the basis of the calculated total energy distribution (TED). The time dependent DFT (TD-DFT) method was employed to predict its electronic properties, such as electronic transitions by UV-Visible analysis, HOMO and LUMO energies, molecular electrostatic potential (MEP) and various global reactivity and selectivity descriptors (chemical hardness, chemical potential, softness, electrophilicity index). Stability of the molecule arising from hyper conjugative interaction, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. Atomic charges obtained by Mulliken population analysis and NBO analysis are compared. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures are also calculated.

Vibrational analysis using FT-IR, FT-Raman spectra and HF-DFT methods and NBO, NLO, NMR, HOMO-LUMO, UV and electronic transitions studies on 2,2,4-trimethyl pentane

In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000cm(-1)and 50-4000cm(-1), respectively, for 2,2,4-Trimethyl Pentane, TMP (C8H18) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and geometrical parameter calculations based on Hartree Fock (HF) and density functional theory (DFT) method with 6-311++G(d,p) basis set. The scaled B3LYP/6-311++G(d,p) results shows the best agreement with the experimental values over the other method. The calculated HOMO and LUMO energies shows that charge transfer within the molecule. The physical reactions of single bond hydrocarbon TMP were investigated. The results of the calculations were applied to simulate spectra of the title compound, which shows the excellent agreement with observed spectra. Besides, Mulliken atomic charges, UV, frontier molecular orbital (FMO), MEP, NLO activity, Natural Bond-Orbital (NBO) analysis, NMR and thermodynamic properties of title molecule were also performed.

Repellent properties of Cardiospermum halicacabum Linn. (Family: Sapindaceae) plant leaf extracts against three important vector mosquitoes

OBJECTIVE

To determine repellent activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Cardiospermum halicacabum (C. halicacabum) against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).

METHODS

Evaluation was carried out in a net cage (45 cm×30 cm×25 cm) containing 100 blood starved female mosquitoes of three mosquito species and were assayed in the laboratory condition by using the protocol of WHO 2005; The plant leaf crude extracts of C. halicacabum was applied at 1.0, 2.5, and 5.0 mg/cm(2) separately in the exposed area of the fore arm. Only ethanol served as control.

RESULTS

In this observation, the plant crude extracts gave protection against mosquito bites without any allergic reaction to the test person, and also, the repellent activity was dependent on the strength of the plant extracts. The tested plant crude extracts had exerted promising repellent against all the three mosquitoes.

CONCLUSIONS

From the results it can be concluded the crude extract of C. halicacabum was potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.

Spectroscopic analysis of cinnamic acid using quantum chemical calculations

In this present study, FT-IR, FT-Raman, (13)C NMR and (1)H NMR spectra for cinnamic acid have been recorded for the vibrational and spectroscopic analysis. The observed fundamental frequencies (IR and Raman) were assigned according to their distinctiveness region. The computed frequencies and optimized parameters have been calculated by using HF and DFT (B3LYP) methods and the corresponding results are tabulated. On the basis of the comparison between computed and experimental results assignments of the fundamental vibrational modes are examined. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by HF and DFT methods. The alternation of the vibration pattern of the pedestal molecule related to the substitutions was analyzed. The (13)C and (1)H NMR spectra have been recorded and the chemical shifts have been calculated using the gauge independent atomic orbital (GIAO) method. The Mulliken charges, UV spectral analysis and HOMO-LUMO analysis of have been calculated and reported. The molecular electrostatic potential (MEP) was constructed.

Spectroscopic and quantum chemical analysis of Isonicotinic acid methyl ester

In this present study, an organic compound Isonicotinic acid methyl ester (INAME) was structurally characterized by FTIR, FT-Raman, and NMR and UV spectroscopy. The optimized geometrical parameters and energies of all different and possible conformers of INAME are obtained from Density Functional Theory (DFT) by B3LYP/6-311++G(d,p) method. There are three conformers (SI, SII-1, and SII-2) for this molecule (ground state). The most stable conformer of INAME is SI conformer. The molecular geometry and vibrational frequencies of INAME in the ground state have been calculated by using HF and density functional method (B3LYP) 6-311++G (d,p) basis set. Detailed vibrational spectral analysis has been carried out and assignments of the observed fundamental bands have been proposed on the basis of peak positions and relative intensities. The computed vibrational frequencies were compared with the experimental frequencies, which yield good agreement between observed and calculated frequencies. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and first hyper polarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results show that the INAME molecule may have microscopic nonlinear optical (NLO) behavior with non zero values. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method.

Normal coordinate analysis and vibrational spectroscopy (FT-IR and FT-Raman) studies of 5-methyl-N-[4-(trifluoromethyl) phenyl]-isoxazole-4-carboxamide using density functional method

Vibrational spectral analysis of 5-methyl-N-[4-(trifluoromethyl) phenyl]-isoxazole-4-carboxamide is (5MN4TPI4C) molecule was carried out using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry, harmonic vibrational wavenumbers, various bonding features have been computed using density functional B3LYP method with 6-311G(d,p) as basis set. The assignments of the vibrational spectra have been carried out with the aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology (SQMFFM). Stability of the molecule arising from hyper conjugative interactions, charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The non-linear optical (NLO) behavior of 5MN4TPI4C has been studied by determination of the electric dipole moment (μ) and hyperpolarizability (β) by using B3LYP/6-311G(d,p) method. The molecular orbital compositions and their contributions to the chemical bonding are studied by Total density of energy states (TDOS), sum of α and β electron (αβDOS) density of states. Thermodynamic properties (heat capacity, entropy and enthalpy) of the title compound at different temperatures are calculated.

Structure and vibrational spectra of melaminium bis(trifluoroacetate) trihydrate: FT-IR, FT-Raman and quantum chemical calculations

Melaminium bis(trifluoroacetate) trihydrate (MTFA), an organic material has been synthesized and single crystals of MTFA have been grown by the slow solvent evaporation method at room temperature. X-ray powder diffraction analysis confirms that MTFA crystal belongs to the monoclinic system with space group P2/c. The molecular geometry, vibrational frequencies and intensity of the vibrational bands have been interpreted with the aid of structure optimization based on density functional theory (DFT) B3LYP method with 6-311G(d,p) and 6-311++G(d,p) basis sets. The X-ray diffraction data have been compared with the data of optimized molecular structure. The theoretical results show that the crystal structure can be reproduced by optimized geometry and the vibrational frequencies show good agreement with the experimental values. The nuclear magnetic resonance (NMR) chemical shift of the molecule has been calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. HOMO-LUMO, and other related molecular and electronic properties are calculated. The Mulliken and NBO charges have also been calculated and interpreted.

Vibrational, DFT, thermal and dielectric studies on 3-nitrophenol-1,3,5-triazine-2,4,6-triamine (2/1)

A new organic-organic salt, 3-nitrophenol-1,3,5-triazine-2,4,6-triamine (2/1) (3-NPM) has been synthesized by slow evaporation technique at room temperature. Single crystal X-ray diffraction analysis reveals that 3-NPM crystallizes in orthorhombic system with centrosymmetric space group Pbca and the lattice parameters are a=15.5150(6) Å, b=12.9137(6) Å, c=17.8323(6) Å, α=β=γ=90° and V=3572.8(2)(Å)(3). The geometry, fundamental vibrational frequencies are interpreted with the aid of structure optimization and normal coordinate force field calculations based on density functional theory (DFT) B3LYP/6-311G(d,p) method. IR and Raman spectra of 3-NPM have been recorded and analyzed. The complete vibrational assignments are made on the basis of potential energy distribution (PED). The electric dipole moment, polarizability and the first order hyperpolarizability values of the 3-NPM have been calculated. (1)H and (13)C NMR chemical shifts are calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP method with 6-311G (d,p) basis set. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties are performed. Mulliken and Natural charges of the title molecule are also calculated and interpreted. Thermal decomposition behavior of 3-NPM has been studied by means of thermogravimetric analysis. The dielectric measurements on the powdered sample have been carried out and the variation of dielectric constant and dielectric loss at different frequencies of the applied field has been studied and the results are discussed in detail.

Vibrational frequency analysis, FT-IR, FT-Raman, ab initio, HF and DFT studies, NBO, HOMO-LUMO and electronic structure calculations on pycolinaldehyde oxime

In this work, the vibrational spectral analysis is carried out by using Raman and infrared spectroscopy in the range 100-4000 cm(-1)and 50-4000 cm(-1), respectively, for pycolinaldehyde oxime (PAO) (C6H6N2O) molecule. The vibrational frequencies have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. The structure optimizations and normal coordinate force field calculations are based on HF and B3LYP methods with 6-311++G(d,p) basis set. The results of the calculation shows excellent agreement between experimental and calculated frequencies in B3LYP/6-311++G(d,p) basis set. The optimized geometric parameters are compared with experimental values of PAO. The non linear optical properties, NBO analysis, thermodynamics properties and mulliken charges of the title molecule are also calculated and interpreted. A study on the electronic properties, such as HOMO and LUMO energies, are performed by time-dependent DFT (TD-DFT) approach. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) are performed. The effects due to the substitutions of CH=NOH ring are investigated. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results.

Larvicidal & ovicidal efficacy of Pithecellobium dulce (Roxb.) Benth. (Fabaceae) against Anopheles stephensi Liston & Aedes aegypti Linn. (Diptera: Culicidae)

BACKGROUND & OBJECTIVES

In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal and ovicidal potential of the crude hexane, benzene, chloroform, ethyl acetate and methanol solvent extracts from the medicinal plant Pithecellobium dulce against the mosquito vectors, Anopheles stephensi and Aedes aegypti (Diptera: Culicidae).

METHODS

Larvicidal activity of P. dulce plant extracts was studied in the range of 60 to 450 mg/l against early third instar larvae of An. stephensi and Ae. aegypti in the laboratory. The larval mortality was observed after 24 h of exposure. The ovicidal activity was determined against An. stephensi and Ae. aegypti to various concentrations ranging from 100 to 750 mg/l under the laboratory conditions. Mean per cent hatchability of the eggs were observed after 48 h post treatment.

RESULTS

All leaf and seed extracts showed moderate larvicidal and ovicidal effects; however, the highest larval mortality was found in methanol extract of leaf of P. dulce against the larvae of An. stephensi and Ae. aegypti with the LC₅₀ and LC₉₀ values 145.43, 155.78 mg/l and 251.23, 279.73 mg/l, respectively. The per cent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. Zero hatchability was observed at 400 mg/l for leaf methanol extract and 625 mg/l for seed methanol extract of P. dulce against An. stephensi and Ae. aegypti, respectively. Compared to leaf extracts, seed extracts have low potency against the two mosquitoes.

INTERPRETATION & CONCLUSIONS

The present results suggest that the leaf and seed extracts of P. dulce have the potential to be used as an ideal eco-friendly approach for the control of mosquitoes.

FT-IR, FT-Raman and UV spectral investigation: computed frequency estimation analysis and electronic structure calculations on 1-bromo-2-methylnaphthalene

In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 100-4000 cm(-1) and 400-4000 cm(-1) respectively, for 1-bromo-2-methylnaphthalene (C11H9Br) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based density functional theory (DFT) and ab initio HF methods with different basis sets combinations. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The results of the calculations were applied to simulated vibrational spectra of the title compound, which show excellent agreement with observed spectra. The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) complements with the experimental findings. In addition, molecular electrostatic potential and nonlinear optical and thermodynamic properties of the title compound were performed. Mulliken charges and NBOs of the title molecule were also calculated and interpreted.

Spectroscopic (FT-IR, FT-Raman, UV and NMR) investigation and NLO, HOMO-LUMO, NBO analysis of organic 2,4,5-trichloroaniline

In this work, the experimental and theoretical study on the molecular structure and vibrational spectra of 2,4,5-trichloroaniline (C(6)H(4)NCl(3), abbreviated as 2,4,5-TClA) were studied. The FT-IR and FT-Raman spectra were recorded. The molecular geometry and vibrational frequencies in the ground state were calculated by using the Hartree-Fock (HF) and density functional theory (DFT) methods (B3LYP) with 6-311++G(d,p) basis set. Comparison of the observed fundamental vibrational frequencies of 2,4,5-TClA with calculated results by HF and DFT indicates that B3LYP is superior to HF method for molecular vibrational problems. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and the first hyperpolarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results also show that the 2,4,5-TClA molecule may have microscopic nonlinear optical (NLO) behavior with non-zero values. Mulliken atomic charges of 2,4,5-TClA was calculated and compared with aniline and chlorobenzene molecules. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results.

FT-IR and FT-Raman spectra, thermo dynamical behavior, HOMO and LUMO, UV, NLO properties, computed frequency estimation analysis and electronic structure calculations on α-bromotoluene

In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4,000 cm(-1) and 50-4,000 cm(-1), respectively, for the title molecules. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartee Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The calculated HOMO and LUMO energies show that charge transfer occurs within molecule. The influences of bromine atom and methyl group on the geometry of benzene and its normal modes of vibrations have also been discussed. The results of the calculations were applied to simulated spectra of the title compounds, which show excellent agreement with observed spectra.

Spectroscopic properties, NLO, HOMO-LUMO and NBO analysis of 2,5-Lutidine

In this work, FT-IR and FT-Raman spectra of 2,5-Lutidine (C(7)H(9)N) have been reported in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. Density functional theory (DFT) has been used to calculate the optimized geometrical parameters, atomic charges, vibrational wavenumbers and intensity of the vibrational bands. The vibrational frequencies have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. The structure optimizations and normal coordinate force field calculations are based on HF and B3LYP methods with 6-311++G(d,p) basis set. The complete vibrational assignments of wavenumbers have been made on the basis of potential energy distribution (PED). The results of the calculation shows excellent agreement between experimental and calculated frequencies in B3LYP/6-311++G(d,p) basis set. The optimized geometric parameters were compared with experimental values of 2,5-Lutidine. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken charges and NBOs of the title molecule were also calculated and interpreted. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The dipole moment, linear polarizability and first hyperpolarizability values were also computed.

Analysis of vibrational spectra (FT-IR and FT-Raman) and nonlinear optical properties of organic 2-chloro-p-xylene

In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 100-4000cm(-1) and 400-4000cm(-1) respectively, for the title molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartree-Fock (HF) and density functional theory (DFT) method with 6-311++G(d,p) basis set. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other method. The influences due to the substitution of halogen bond and methyl group were investigated. The results of the calculations are applied to simulate the vibrational spectra of the title compound, which show excellent agreement with observed spectra. The absorption energy and oscillator strength are calculated by time-dependent density functional theory (TD-DFT). Besides, frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP), and thermodynamic properties were performed. Mulliken charges of the title molecule were also calculated and interpreted. The dipole moment, linear polarizability and first hyperpolarizability values were also computed.

Vibrational spectroscopic studies, NLO, HOMO-LUMO and electronic structure calculations of α,α,α-trichlorotoluene using HF and DFT

FT-IR and FT-Raman spectra of α,α,α-trichlorotoluene have been recorded and analyzed. The geometry, fundamental vibrational frequencies are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) B3LYP/6-311++G(d,p) method and a comparative study between HF level and various basis sets combination. The fundamental vibrational wavenumbers as well as their intensities were calculated and a good agreement between observed and scaled calculated wavenumbers has been achieved. The complete vibrational assignments of wavenumbers are made on the basis of potential energy distribution (PED). The effects due to the substitutions of methyl group and halogen were investigated. The absorption energy and oscillator strength are calculated by time-dependent density functional theory (TD-DFT). The electric dipole moment, polarizability and the first hyperpolarizability values of the α,α,α-trichlorotoluene have been calculated. (1)H NMR chemical shifts were calculated by using the gauge independent atomic orbital (GIAO) method with HF and B3LYP methods with 6-311++G(d,p) basis set. Moreover, molecular electrostatic potential (MEP) and thermodynamic properties were performed. Mulliken and natural charges of the title molecule were also calculated and interpreted.

Seckel syndrome: a report of a case

Seckel syndrome, first defined by Seckel in 1960, is a rare (incidence 1:10,000), genetically heterogeneous autosomal recessive disorder presenting at birth. This syndrome is characterized by a proportionate dwarfism of prenatal onset, a severe microcephaly with a "bird-headed" like appearance (beaked nose, receding forehead, prominent eyes, and micrognathia), and mental retardation. The significance of dental alterations in this syndrome resides in the defect, hypoplastic enamel, being limited to the primary dentition; in most instances the second primary molar tooth is not affected. A case of the Seckel syndrome is presented.

Adulticidal properties of Cardiospermum halicacabum plant extracts against three important vector mosquitoes

OBJECTIVE

To determine adulticidal activitiy of hexane, ethyl acetate, benzene, chloroform and methanol leaf extracts of Cardiospermum halicacabum against Culex quinquefasciatus (Cx. quinquefasciatus), Aedes aegypti (Ae. aegypti) and Anopheles stephensi (An. stephensi).

MATERIALS AND METHODS

The bioassay was conducted in an experimental kit consisting of two cylindrical plastic tubes both measuring 125 x 44 mm following the WHO method; Mortality of the mosquitoes was recorded after 24 h.

RESULTS

The adulticidal activity of plant extracts showed moderate toxic effect on the adult mosquitoes after 24 h of exposure period. However, compared to other solvents highest mortality was found in methanol extract of C. halicacabum against all the three mosquitoes. Among them An. stephensi produce the highest LC50 and LC90 (186.00 and 346.06 ppm) values.

CONCLUSIONS

From the results it can be concluded the crude extract of C. halicacabum was an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.

FT-IR, FT-Raman, ab initio, HF and DFT studies, NBO, HOMO-LUMO and electronic structure calculations on 4-chloro-3-nitrotoluene

In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000 cm(-1) and 50-4000 cm(-1), respectively, for 4-chloro-3-nitrotoluene (C7H6NO2Cl) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartree Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The calculated HOMO and LUMO energies shows that charge transfer within the molecule. The effects due to the substitutions of methyl group, nitro group and halogen were investigated. The results of the calculations were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) and thermodynamic properties were performed.

Larvicidal efficacy of botanical extracts against two important vector mosquitoes

OBJECTIVE

To determine the larvicidal efficacy of different solvent leaf extract of Ervatamia coronaria and Caesalpinia pulcherrima against Anopheles subpictus and Culex tritaeniorhynchus.

MATERIALS AND METHODS

Twenty five early third instar larvae of Anopheles subpictus and Culex tritaeniorhynchus were exposed to various concentrations and were assayed in the laboratory. The larval mortality was observed after 24 h of treatment.

RESULTS

Among three solvent extracts tested the maximum efficacy was observed in the methanol extract. The LC50 (LC90) values of Ervatamia coronaria and Caesalpinia pulcherrima against early third instar of Anopheles subpictus were 86.47 (159.59) and 113.26 (207.73) ppm and Culex tritaeniorhynchus were 131.53 (245.37) and 165.28 (299.45) ppm, respectively. No mortality was observed in controls.

CONCLUSIONS

From the results it can be concluded the crude extract of Ervatamia coronaria and Caesalpinia pulcherrima were excellent potential for controlling Anopheles subpictus and Culex tritaeniorhynchus mosquito larvae.

FT-IR, FT-Raman and UV spectral investigation: computed frequency estimation analysis and electronic structure calculations on chlorobenzene using HF and DFT

In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 100-4000 cm(-1) and 400-4000 cm(-1) respectively, for the title molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartree Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The effects due to the substitution of halogen bond were investigated. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) results complements with the experimental findings. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP), and thermodynamic properties were performed. The thermodynamic properties of the title compound at different temperatures have been calculated, revealing the correlations between heat capacity (C), entropy (S), and enthalpy changes (H) and temperatures.

FT-IR, FT-Raman and UV spectral investigation; computed frequency estimation analysis and electronic structure calculations on 1-nitronaphthalene

In this work, the vibrational spectral analysis was carried out by using FT-Raman and FT-IR spectroscopy in the range 100-4000cm(-1) and 400-4000cm(-1) respectively, for 1-nitronaphthalene (C(10)H(7)NO(2)) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based density functional theory (DFT) and ab initio HF methods and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of total energy distribution (TED). The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The energy and oscillator strength calculated by time-dependent density functional theory (TD-DFT) complements with the experimental findings. Thermodynamic properties of the title compound at different temperatures have been calculated. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) were performed.

Oviposition attractancy of dodecanoic, hexadecanoic and tetradecanoic acids against Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae)

OBJECTIVE

Vector control is facing a threat due to emergence of resistance to synthetic insecticides. Compounds that mediate the oviposition of mosquitoes: a possible sustainable tool for the control and monitoring of Culicidae. The present study to evaluate oviposition attractancy of dodecanoic, hexadecanoic and tetradecanoic acid (isolated from conspecific eggs) against gravid female Aedes (Ae.) aegypti and Culex (Cx.) quinquefasciatus mosquitoes.

MATERIALS AND METHODS

The oviposition attractancy was determined against two mosquito species to various concentrations viz., 1, 10, and 50 ppm. The attractancy was assessed after 24 h experiment in laboratory condition. After 24 h, the number of eggs laid in treated and control bowls were counted under the stereo microscope.

RESULTS

Significant level of concentration-dependent positive oviposition response of mosquitoes to dodecanoic acid, hexadecanoic acid and tetradecanoic acid were observed. Dodecanoic acid have more attractancy in higher concentrations. The oviposition active index (OAI) values of dodecanoic acid against Ae. aegypti and Cx. quinquefasciatus at the concentration of 50 ppm were 0.52 and 0.50 respectively. Whereas hexadecanoic acid shows more attractancy in lower concentration (1 ppm) for both Ae. aegypti and Cx. quinquefasciatus and the values were 0.40 and 0.36 respectively. The result of tetradecanoic acid provides positive response in all concentrations of both mosquitoes. The higher OAI value 0.65 was observed in 10 ppm for Ae. aegypti and 0.55 in 1 ppm for Cx. quinquefasciatus. Among the three compounds tested tetradecanoic acid shows more attractancy to Ae. aegypti and Cx. quinquefasciatus.

CONCLUSIONS

In this result it can be concluded that the three compounds possess remarkable oviposition attractancy against Ae. aegypti and Cx. quinquefasciatus.

Ovicidal and repellent properties of Coccinia indica Wight and Arn. (Family:Cucurbitaceae) against three important vector mosquitoes

OBJECTIVE

To determine the larvicidal and repellent activities of Coccinia (C) indica Wight and Arnold (Family:Cucurbitaceae) extract against Culex (Cx.) quinquefasciatus, Aedes (Ae.) aegypti and Anopheles (An.) stephensi.

MATERIALS AND METHODS

The ovicidal activity was determined against three mosquito species to various concentrations ranging from 50-300 ppm under the laboratory conditions. The hatch rates were assessed 48 h post treatment. The repellent efficacy was determined against three mosquito species at three concentrations viz., 1.0, 2.5 and 5.0 mg/cm2 under the laboratory conditions.

RESULTS

Among five solvent extracts tested, the methanol extract have most promising ovicidal activity. The methanol extract exerted zero hatchability (100% mortality) at 150 ppm for Cx. quinquefasciatus, at 200 ppm for Ae. aegypti and An. stephensi. The methanol extract of C. indica found to be more repellency than the other extracts. A higher concentration of 5.0 mg/cm2 provided 100% protection up to 270 min against Cx. quinquefasciatus and 210 min against Ae. aegypti and An. stephensi, respectively. The results clearly show that repellent activity was dose dependent.

CONCLUSIONS

From the results it can be concluded the crude extract of C. indica was an excellent potential for controlling Cx. quinquefasciatus, Ae. aegypti and An. stephensi mosquitoes.

Vibrational spectroscopic analysis of 2-bromobenzoic and anthranilic acids: a combined experimental and theoretical study

In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000 cm(-1) and 50-4000 cm(-1) respectively, for the title molecules. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartee-Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wavenumbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The effects due to the substitutions of amino group and halogen bond were investigated. The results of the calculations were applied to simulate spectra of the title compounds, which show excellent agreement with observed spectra.

Experimental (FT-IR and FT-Raman), electronic structure and DFT studies on 1-methoxynaphthalene

In this work, FT-IR and FT-Raman spectra of 1-methoxynapthalene (C(11)H(10)O) have been reported in the regions 4000-400 cm(-1) and 3500-100 cm(-1), respectively. Density functional method (DFT) has been used to calculate the optimized geometrical parameters, atomic charges, vibrational wavenumbers and intensity of the vibrational bands. The vibrational frequencies have been calculated and scaled values are compared with experimental FT-IR and FT-Raman spectra. The structure optimizations and normal coordinate force field calculations are based on density functional theory (DFT) method with B3LYP/3-21G, B3LYP/6-31G, B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p) basis sets. The complete vibrational assignments of wavenumbers are made on the basis of potential energy distribution (PED). The optimized geometric parameters are compared with experimental values of naphthoic acid. The results of the calculation shows excellent agreement between experimental and calculated frequencies in B3LYP/6-311++G(d,p) basis set. The effects due to the substitutions of methyl group and carbon-oxygen bond are also investigated. A study on the electronic properties, such as excitation energies and wavelengths, were performed by time-dependent DFT (TD-DFT) approach. HOMO and LUMO energies are calculated that these energies show charge transfer occurs within the molecule.

Mosquito larvicidal and ovicidal activity of Cardiospermum halicacabum Linn. (family: Sapindaceae) leaf extract against Culex quinquefasciatus (Say.) and Aedes aegypti (Linn.) (Diptera: Culicidae)

OBJECTIVE

To investigate the larvicidal and ovicidal efficacy of different extracts of Cardiospermum halicacabum L. against Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae).

MATERIALS AND METHODS

Larvicidal efficacy of the crude leaf extracts of Cardiospermum halicacabum with five different solvents like benzene, hexane, ethyl acetate, methanol and chloroform was tested against the early third instar larvae of Culex (C.) quinquefasciatus and Aedes (A.) aegypti. The ovicidal activity was determined against two mosquito species to various concentrations ranging from 100-600 ppm under the laboratory conditions.

RESULTS

The benzene, hexane, ethyl acetate, methanol and chloroform leaf extract of Cardiospermum halicacabum was found to be more effective against C. quinquefasciatus than A. aegypti. The LC50 values were 174.24, 193.31, 183.36, 150.44, 154.95 ppm and 182.51, 200.02, 192.31, 156.80, 164.54 ppm respectively. Among five solvent tested the methanol and benzene crude extract was found to be most effective for ovicidal activity against two mosquito species. The extract of methanol and benzene exerted 100% mortality at 300 ppm against C quinquefasciatus. A. aegypti attained the complete ovicidal activity at 400 ppm for the extract of methanol only.

CONCLUSIONS

From the results it can be concluded the crude extract of Cardiospermum halicacabum was a potential for controlling C. quinquefasciatus and A. aegypti mosquitoes.

Mosquito larvicidal and ovicidal properties of Eclipta alba (L.) Hassk (Asteraceae) against chikungunya vector, Aedes aegypti (Linn.) (Diptera: Culicidae)

OBJECTIVE

The present study deals with the investigation of larvicidal and ovicidal activities of benzene, hexane, ethyl acetate, methanol and chloroform leaf extract of Eclipta alba (E. alba) against dengue vector, Aedes aegypti (Ae. Aegypti).

METHODS

Twenty five early III instar larvae of Ae. aegypti was exposed to various concentrations (50-300 ppm) and was assayed in the laboratory by using the protocol of WHO 2005; the 24 h LC(50) values of the E. alba leaf extract was determined by Probit analysis. For ovicidal activity, slightly modified method of Su and Mulla was performed. The ovicidal activity was determined against Ae. aegypti to various concentrations ranging from 100-350 ppm under the laboratory conditions. The egg hatch rates were assessed 48 h post treatment.

RESULTS

The LC(50) values of benzene, hexane, ethyl acetate, methanol and chloroform extract of E. alba against early third instar larvae of Ae. aegypti were 151.38, 165.10, 154.88, 127.64 and 146.28 ppm, respectively. Maximum larvicidal activity was observed in the methanol extract followed by chloroform, benzene, ethyl acetate and hexane extract. No mortality was observed in control. Among five solvent tested the methanol extract was found to be most effective for ovicidal activity against Ae. aegypti. The methanol extracts exerted 100% mortality (zero hatchability) at 300 ppm.

CONCLUSIONS

From the results it can be concluded the crude extract of E. alba was an excellent potential for controlling Ae. aegypti mosquito.

Vibrational spectroscopic analysis of 2-chlorotoluene and 2-bromotoluene: a combined experimental and theoretical study

In this work, the vibrational spectral analysis was carried out using Raman and infrared spectroscopy in the range 100-4000 cm(-1) and 50-4000 cm(-1), respectively, for the title molecules. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on Hartee Fock (HF) and density functional theory (DFT) method and different basis sets combination. The complete vibrational assignments of wave numbers were made on the basis of potential energy distribution (PED). The scaled B3LYP/6-311++G(d,p) results show the best agreement with the experimental values over the other methods. The effects due to the substitutions of methyl group and halogen bond were investigated. The results of the calculations were applied to simulated spectra of the title compounds, which show excellent agreement with observed spectra.

DFT (LSDA, B3LYP and B3PW91) comparative vibrational spectroscopic analysis of alpha-acetonaphthone

FT-IR and FT-Raman spectra of alpha-acetonaphthone have been recorded and analyzed. The geometry, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and normal coordinate force field calculations based on density functional theory (DFT) B3PW91/6-311G method and also a comparative studies between different levels and various basis sets combination. The scaled B3PW91/6-11G results are best, even though LSDA/6-311G wavenumbers are well in agreement before scaling. The complete vibrational assignments of wavenumbers are made on the basis of potential energy distribution (PED). The effects due to the substitutions of methyl group and carbon-oxygen bond are investigated. The results of the calculations are applied to simulated spectra of the title compound, which shows excellent agreement with observed spectra.

FT-IR and FT-Raman vibrational spectra and molecular structure investigation of nicotinamide: A combined experimental and theoretical study

In this work, the experimental and theoretical spectra of nicotinamide (C(6)H(6)N(2)O) are studied. FT-IR and FT-Raman spectra of title molecule in the liquid phase have been recorded in the region 4000-100cm(-1). The structural and spectroscopic data of the molecule in the ground state have been calculated by using Hartree-Fock and density functional method (B3LYP) with the 6-31+G*(d, p) and 6-31++G* (d, p)basis set. The vibrational frequencies have been calculated and scaled values have been compared with the experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found in good agreement. The DFT-B3LYP/6-31++G (d, p) calculations have been found are more reliable than the ab initio HF/6-31+G (d, p) calculations for the vibrational study of nicotinamide. The optimized geometric parameters (bond lengths and bond angles) are compared with experimental values of the molecule. The alteration of vibrational bands due to the substitutions in the base molecule is also investigated from their characteristic region of linked spectrum.

FTIR and FTRaman spectra, assignments, ab initio HF and DFT analysis of 4-nitrotoluene

In this work, the experimental and theoretical study on molecular structure and vibrational spectra of 4-nitrotoluene are studied. The FTIR and FTRaman experimental spectra of the molecule have been recorded in the range of 4000-100 cm(-1). Making use of the recorded data, the complete vibrational assignments are made and analysis of the observed fundamental bands of molecule is carried out. The experimental determinations of vibrational frequencies are compared with those obtained theoretically from ab initio HF and DFT quantum mechanical calculations using HF/6-31G (d, p), B3LYP/6-31++G* (d, p) and B3LYP/6-311++G* (d, p) methods. The differences between the observed and scaled wave number values of most of the fundamentals are very small in B3LYP than HF. The geometries and normal modes of vibrations obtained from ab initio HF and B3LYP calculations are in good agreement with the experimentally observed data. Comparison of the simulated spectra provides important information about the ability of the computational method (B3LYP) to describe the vibrational modes. The vibrations of NO(2) and CH(3) groups coupled with skeletal vibrations are also investigated.

Larvicidal efficacy of Ficus benghalensis L. plant leaf extracts against Culex quinquefasciatus Say, Aedes aegypti L. and Anopheles stephensi L. (Diptera: Culicidae)

OBJECTIVE

To investigate the larvicidal efficacy of different extracts of Ficus benghalensis L. against Culex quinquefasciatus Say, Aedes aegypti L. and Anopheles stephensi L. (Diptera: Culicidae).

MATERIALS AND METHODS

Larvicidal efficacy of the crude leaf extracts of Ficus benghalensis with three different solvents like methanol, benzene and acetone was tested against the early second, third, fourth instar larvae of Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi.

RESULTS

The larval mortality was observed after 24 h of treatment. Among the three solvents the maximum efficacy was observed in methanol. The letal concentration (LC50) values of Ficus benghalensis against early second, third and fourth larvae of Culex quinquefasciatus, Aedes Aegypti and Anopheles stephensi were 41.43, 58.21 and 74.32 ppm, 56.54, 70.29 and 80.85 ppm and 60.44, 76.41 and 89.55 ppm respectively. No mortality was observed in controls. The chi-square value were significant at p < 0.05 level.

CONCLUSION

The methanol extract of F. benghalensis showed good larvicidal activity against three vector mosquitoes.