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1.
J Imaging Inform Med ; 37(3): 1008-1022, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38351226

RESUMO

The early detection and accurate diagnosis of liver fibrosis, a progressive and potentially serious liver condition, are crucial for effective medical intervention. Invasive methods like biopsies for diagnosis can be risky and expensive. This research presents a novel computer-aided diagnosis model for liver fibrosis using a hybrid approach of minimum redundancy maximum relevance (MRMR) feature selection, bidirectional long short-term memory (BiLSTM), and convolutional neural networks (CNN). The proposed model involves multiple stages, including image acquisition, preprocessing, feature representation, fibrous tissue identification, and classification. Notably, histogram equalization is employed to enhance image quality by addressing variations in brightness levels. Performance evaluation encompasses a range of metrics such as accuracy, precision, sensitivity, specificity, F1 score, and error rate. Comparative analyses with established methods like DCNN, ANN-FLI, LungNet22, and SDAE-GAN underscore the efficacy of the proposed model. The innovative integration of hybrid MRMR-BiLSTM-CNN architecture and the horse herd optimization algorithm significantly enhances accuracy and F1 score, even with small datasets. The model tackles the complexities of hyperparameter optimization through the IHO algorithm and reduces training time by leveraging MRMR feature selection. In practical application, the proposed hybrid MRMR-BiLSTM-CNN method demonstrates remarkable performance with a 97.8% accuracy rate in identifying liver fibrosis images. It exhibits high precision, sensitivity, specificity, and minimal error rate, showcasing its potential for accurate and non-invasive diagnosis.


Assuntos
Algoritmos , Cirrose Hepática , Redes Neurais de Computação , Cirrose Hepática/diagnóstico , Cirrose Hepática/patologia , Cirrose Hepática/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Fígado/patologia , Fígado/diagnóstico por imagem , Diagnóstico por Computador/métodos
2.
Expert Rev Med Devices ; 19(12): 991-999, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36524400

RESUMO

OBJECTIVES: In recent years, audio signal processing begins its outbreak on a global scale, which has altered the global market and has rapidly extended out as a fundamental design in various industries. Lifting based method is frequently implemented in many applications such as image processing and audio processing because it has some advantages that faster implementation with minimum computational cost. METHODS: In this proposed work, a Novel Lifting based Filter Bank (NLFB) is proposed using a modified variable filter aimed at digital hearing aid devices. This filter bank design has some mandatory constraints, such as hardware complexity, power consumption, and delay. The proposed method is designed with four lifting steps such as split, predict, update and merge to make the perfect reconstruction in analysis and decomposition in synthesis bank. The performance analysis of the proposed method is discussed in this article. RESULTS: The proposed method consumes less power, up to 45mW, and a minimum delay between 85ns and 91.1ns when compared to traditional methods. CONCLUSION: The proposed design output consumes 32 % of minimum hardware components, 12% of low power compared to interpolated filter bank and 6% of delay is reduced using Modified Variable Filter (MVFB).


Assuntos
Auxiliares de Audição , Humanos , Remoção , Processamento de Sinais Assistido por Computador , Processamento de Imagem Assistida por Computador , Algoritmos
3.
J Photochem Photobiol B ; 140: 359-64, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25240425

RESUMO

A new series of substituted ethyl 10-chloro-4-(3,4-dimethoxyphenyl)-2-hydroxy-12-phenyl-1,4,5,6-tetrahydrobenzo[a]acridine-3-carboxylates, 3a-e have been synthesized through NaOH base mediated cyclocondensation of (E)-7-chloro-2-(3,4-dimethoxybenzylidene)-9-phenyl-3,4-dihydroacridin-1(2H)-ones, 1a-e with ethyl acetoacetate. Structures of these synthesized molecules were studied by FT-IR, (1)H NMR, (13)C NMR and EI-MS. And all the synthesized compounds were evaluated for their UV-absorption studies with various metal solutions. Acridine-3-carboxylate derivatives were tested against fourth instar larvae of Anopheles stephensi and Hippobosca maculata. Among those compounds, 3b and 3e have good larvicidal activities against both A.stephensi and H.maculata. Toxicity of compounds, 3b and 3e compounds were evaluated with the reference non-target aquatic species like, Sphaerodema annulatum Fabricius (Heteroptera: Belostomatidae) and Zyxomma petiolatum Rambur (Odonata: Libellulidae) results very low LC50 values revels that, the synthetic compounds are non toxic.


Assuntos
Ácidos Carboxílicos/química , Inseticidas/química , Solventes/química , Animais , Anopheles , Larva/efeitos dos fármacos
4.
Braz. j. microbiol ; 44(4): 1089-1095, Oct.-Dec. 2013. graf, tab
Artigo em Inglês | LILACS | ID: lil-705254

RESUMO

The influence of various oil cakes has been investigated for high level production of lipase using Aspergillus tamarii MTCC 5152. By solid state fermentation in wheat bran containing 2.5% w/w gingili oil cake at 70% v/w moisture content the fungus produced a maximal yield of lipase (758 ± 3.61 u/g) after 5 days of incubation using 2% v/w inoculum containing 10(6) spores/mL. Wheat bran and gingili oil cake with supplementation of gingili oil (1.0% w/w), glucose (0.5% w/w) and peptone (0.5% w/w) gives an increased enzyme production of 793 ± 6.56 u/g. The enzyme shows maximum activity at pH 7.0, temperature 50 °C and was stable between the pH 5.0-8.0 and temperature up to 60 °C. Crude lipase (3%) applied to tannery fleshing shows 92% fat solubility. The results demonstrate that fat obtained from tannery fleshing, a by-product of the leather industry has a high potential for biodiesel production and the proteinaceous residue obtained can be used as animal feed.


Assuntos
Tecido Adiposo/metabolismo , Aspergillus/enzimologia , Lipase/metabolismo , Meios de Cultura/química , Concentração de Íons de Hidrogênio , Temperatura
5.
Braz J Microbiol ; 44(4): 1089-95, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24688497

RESUMO

The influence of various oil cakes has been investigated for high level production of lipase using Aspergillus tamarii MTCC 5152. By solid state fermentation in wheat bran containing 2.5% w/w gingili oil cake at 70% v/w moisture content the fungus produced a maximal yield of lipase (758 ± 3.61 u/g) after 5 days of incubation using 2% v/w inoculum containing 10(6) spores/mL. Wheat bran and gingili oil cake with supplementation of gingili oil (1.0% w/w), glucose (0.5% w/w) and peptone (0.5% w/w) gives an increased enzyme production of 793 ± 6.56 u/g. The enzyme shows maximum activity at pH 7.0, temperature 50 °C and was stable between the pH 5.0-8.0 and temperature up to 60 °C. Crude lipase (3%) applied to tannery fleshing shows 92% fat solubility. The results demonstrate that fat obtained from tannery fleshing, a by-product of the leather industry has a high potential for biodiesel production and the proteinaceous residue obtained can be used as animal feed.


Assuntos
Tecido Adiposo/metabolismo , Aspergillus/enzimologia , Lipase/metabolismo , Meios de Cultura/química , Concentração de Íons de Hidrogênio , Temperatura
6.
Artigo em Inglês | MEDLINE | ID: mdl-22983203

RESUMO

In the present study, the biosynthesis of rutile TiO(2) nanoparticles (TiO(2) NPs) was achieved by a novel, biodegradable and convenient procedure using fruit peel Annona squamosa aqueous extract. This is the first report on the new, simple, rapid, eco-friendly and cheaper methods for the synthesis of rutile TiO(2) NPs at lower temperature using agricultural waste. Rutile TiO(2) NPs were characterized by UV, XRD, SEM, TEM and EDS studies. The UV-Vis spectrophotometer results were promising and showed a rapid production of TiO(2) NPs with a surface plasmon resonance occurring at 284 nm. The formation of the TiO(2) NPs as observed from the XRD spectrum is confirmed to be TiO(2) particles in the rutile form as evidenced by the peaks at 2θ=27.42°, 36.10°, 41.30° and 54.33° when compared with the literature. The TEM images showed polydisperse nanoparticles with spherical shapes and size 23±2 nm ranges.


Assuntos
Annona/química , Corantes/química , Química Verde/métodos , Nanopartículas/química , Extratos Vegetais/química , Titânio/química , Química Verde/economia , Nanopartículas/ultraestrutura , Extratos Vegetais/síntese química , Espectrofotometria Ultravioleta , Ressonância de Plasmônio de Superfície , Difração de Raios X
7.
Artigo em Inglês | MEDLINE | ID: mdl-22579326

RESUMO

Acridin-1(2H)-one analogue of 7-chloro-3,4-dihydro-9-phenyl-2-[(pyridine-2yl) methylene] acridin-1(2H)-one, 5 was prepared by using 7-chloro-3,4-dihydro-9-phenylacridin-1(2H)-one, 3 and picolinaldehyde, 4 in the presence of KOH at room temperature. These compounds were characterized by analytical and spectral analyses. The purpose of the present study was to assess the efficacy of larvicidal and repellent activity of synthesized 7-chloro-3,4-dihydro-9-phenyl-acridin-1(2H)-one analogues such as compounds 3 and 5 against the early fourth instar larvae of filariasis vector, Culex quinquefasciatus and Japanese encephalitis vector, Culex gelidus (Diptera: Culicidae). The compound exhibited high larvicidal effects at 50mg/L against both the mosquitoes with LC(50) values of 25.02 mg/L (r(2)=0.998) and 26.40 mg/L (r(2)=0.988) against C. quinquefasciatus and C. gelidus, respectively. The 7-chloro-3,4-dihydro-9-phenyl-acridin-1(2H)-one analogues that are reported for the first time to our best of knowledge can be better explored for the control of mosquito population. This is an ideal ecofriendly approach for the control of Japanese encephalitis vectors, C. quinquefasciatus and C. gelidus.


Assuntos
Acridinas/farmacologia , Culex/efeitos dos fármacos , Inseticidas/farmacologia , Acridinas/síntese química , Acridinas/química , Animais , Larva/efeitos dos fármacos , Espectroscopia de Ressonância Magnética
8.
Artigo em Inglês | MEDLINE | ID: mdl-22349888

RESUMO

In the present study, the biosynthesis of TiO(2) nanoparticles (TiO(2) NPs) was achieved by a novel, biodegradable and convenient procedure using Aspergillus flavus as a reducing and capping agent. Research on new, simple, rapid, eco-friendly and cheaper methods has been initiated. TiO(2) NPs were characterized by FTIR, XRD, AFM, SEM and TEM studies. The X-ray diffraction showed the presence of increased amount of TiO(2) NPs which can state by the presence of peaks at rutile peaks at 100, 002, 100 and anatase forms at 101 respectively. SEM observations revealed that synthesized TiO(2) NPs were spherical, oval in shape; individual nanoparticles as well as a few aggregate having the size of 62-74 nm. AFM shows crystallization temperature was seen on the roughness of the surface of TiO(2). The Minimum inhibitory concentration value for the synthesized TiO(2) NPs was found to be 40 µg ml(-1) for Escherichia coli, which was corresponding to the value of well diffusion test. This is the first report on antimicrobial activity of fungus-mediated synthesized TiO(2) NPs, which was proved to be a good novel antibacterial material.


Assuntos
Antibacterianos/farmacologia , Aspergillus flavus/metabolismo , Nanopartículas/microbiologia , Nanotecnologia/métodos , Titânio/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Aspergillus flavus/citologia , Aspergillus flavus/enzimologia , Escherichia coli/efeitos dos fármacos , Infecções por Escherichia coli/tratamento farmacológico , Nanopartículas/química , Nanopartículas/ultraestrutura , Oxirredução , Espectroscopia de Infravermelho com Transformada de Fourier , Titânio/química , Titânio/metabolismo , Difração de Raios X
9.
Res Vet Sci ; 93(1): 303-9, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21906765

RESUMO

Traditional parasite control is primarily based on the use of chemical acaricides, which unfortunately have many negative side effects. The aim of the present study was to evaluate the effect of plant synthesized silver nanoparticles (AgNPs) using aqueous leaf extract of Manilkara zapota to control Rhipicephalus (Boophilus) microplus. The synthesized AgNPs were characterized by UV-vis spectrum, scanning electron microscopy (SEM), Fourier transform infrared and X-ray diffraction. The UV-vis spectrum of the aqueous medium containing silver nanostructures showed a peak at 421 nm corresponding to the surface plasmon resonance band of AgNPs. SEM supports the biosynthesis and characterization of AgNPs with spherical and oval in shape and size of 70-140 nm. Acaricidal activity of aqueous leaf extract of M. zapota and synthesized AgNPs were carried out against R. (B.) microplus and the results showed the LC(50) values of 16.72 and 3.44 mg/L; r(2)=0.856 and 0.783), respectively.


Assuntos
Acaricidas , Manilkara , Nanopartículas Metálicas , Extratos Vegetais , Rhipicephalus , Animais , Feminino , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Folhas de Planta , Prata , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
10.
Indian J Med Res ; 134: 375-83, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21985822

RESUMO

BACKGROUND & OBJECTIVES: Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of plant origin may serve as suitable alternative biocontrol techniques in the future. The purpose of the present study was to assess the ethyl acetate, acetone and methanol extracts of Andrographis paniculata, Eclipta prostrata and Tagetes erecta leaves tested for oviposition-deterrent, ovicidal and repellent activities against malaria vector, Anopheles subpictus Grassi (Diptera: Culicidae). METHODS: The dried leaves of the three plants were powdered mechanically and extracted with ethyl acetate, acetone and methanol. One gram of crude extract was first dissolved in 100 ml of acetone (stock solution). From the stock solution, test solution concentrations of 31.21- 499.42 mg/l for oviposition- deterrence assay and repellency and 15.60 - 998.85 mg/l were used in ovicidal assay. The percentage oviposition- deterrence, hatching rate of eggs and protection time were calculated. One-way analysis of variance was used for the multiple concentration tests and for per cent mortality to determine significant treatment differences. RESULTS: The percentage of effective oviposition repellency was highest at 499.42 mg/l and the lowest at 31.21 mg/l in ethyl acetate, acetone and methanol extracts of A. paniculata, E. prostrata and T. erecta. The oviposition activity index (OAI) value of ethyl acetate, acetone and methanol extracts of A. paniculata, E. prostrata and T. erecta at 499.42 mg/l were -0.91, -0.93, -0.84, -0.84, -0.87, -0.82, -0.87, -0.89 and -0.87, respectively. Mortality (no egg hatchability) was 100 per cent with ethyl acetate and methanol extracts of A. paniculata, E. prostrata and T. erecta at 998.85 mg/l. The maximum adult repellent activity was observed at 499.42 mg/l in ethyl acetate extracts of A. paniculata, E. prostrata and methanol extracts of T. erecta, and the mean complete protection time ranged from 120 to 150 min with the different extracts tested. INTERPRETATION & CONCLUSIONS: The acetone extract of A. paniculata, methanol extract of E. prostrata and T. erecta showed good oviposition-deterrent, ovicidal and repellent activities respectively. These results suggest that the leaf extracts of A. paniculata, E. prostrata and T. erecta may have the potential to be used as an ideal eco-friendly approach for the control of the An. subpictus.


Assuntos
Andrographis/química , Anopheles/efeitos dos fármacos , Eclipta/química , Insetos Vetores/efeitos dos fármacos , Controle de Mosquitos/métodos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Tagetes/química , Acetatos , Acetona , Análise de Variância , Animais , Índia , Metanol , Oviposição/efeitos dos fármacos , Óvulo/efeitos dos fármacos
11.
Indian J Med Res ; 134: 101-6, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21808141

RESUMO

BACKGROUND & OBJECTIVES: Mosquitoes transmit serious human diseases, causing millions of deaths every year and the development of resistance to chemical insecticides resulting in rebounding vectorial capacity. Plants may be alternative sources of mosquito control agents. The present study assessed the role of larvicidal activities of hexane, chloroform, ethyl acetate, acetone, and methanol dried leaf and bark extracts of Annona squamosa L., Chrysanthemum indicum L., and Tridax procumbens L. against the fourth instar larvae of malaria vector, Anopheles subpictus Grassi and Japanese encephalitis vector, Culex tritaeniorhynchus Giles (Diptera: Culicidae). METHODS: Larvicidal activities of three medicinal plant extracts were studied in the range of 4.69 to 1000 mg/l in the laboratory bioassays against early 4 th instar larvae of An. subpictus and Cx. tritaeniorhynchus. The mortality 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 respective species. RESULTS: All plant extracts showed moderate effects after 24 h of exposure; however, the highest toxic effect of bark methanol extract of A. squamosa, leaf ethyl acetate extract of C. indicum and leaf acetone extract of T. procumbens against the larvae of An. subpictus (LC 50 = 93.80, 39.98 and 51.57 mg/l) and bark methanol extract of A. squamosa, leaf methanol extract of C. indicum and leaf ethyl acetate extract of T. procumbens against the larvae of Cx. tritaeniorhynchus (LC50 =104.94, 42.29 and 69.16 mg/l) respectively. INTERPRETATION & CONCLUSIONS: Our data suggest that the bark ethyl acetate and methanol extract of A. squamosa, leaf ethyl acetate and methanol extract of C. indicum, acetone and ethyl acetate extract of T. procumbens have the potential to be used as an ecofriendly approach for the control of the An. subpictus, and Cx. tritaeniorhynchus.


Assuntos
Annona/química , Anopheles/efeitos dos fármacos , Asteraceae/química , Chrysanthemum/química , Culex/efeitos dos fármacos , Inseticidas/farmacologia , Casca de Planta/química , Extratos Vegetais/farmacologia , Acetatos/química , Animais , Relação Dose-Resposta a Droga , Humanos , Inseticidas/química , Larva/efeitos dos fármacos , Malária/prevenção & controle , Metanol/química , Extratos Vegetais/química
12.
Acta Trop ; 118(3): 196-203, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21419749

RESUMO

Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of synthesized natural products for vector control have been a priority in this area. In this study, larvicidal activity of synthesized silver nanoparticles (AgNPs) utilizing aqueous extract from Eclipta prostrata, a member of the Asteraceae was investigated against fourth instar larvae of filariasis vector, Culex quinquefasciatus say and malaria vector, Anopheles subpictus Grassi (Diptera: Culicidae). The synthesized AgNPs characterized by UV-vis spectrum, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and X-ray diffraction (XRD). SEM analyses of the synthesized AgNPs were clearly distinguishable measured 35-60 nm in size. Larvae were exposed to varying concentrations of aqueous extract of synthesized AgNPs for 24h. The maximum efficacy was observed in crude aqueous, and synthesized AgNPs against C. quinquefasciatus (LC(50)=27.49 and 4.56 mg/L; LC(90)=70.38 and 13.14 mg/L), and against A. subpictus (LC(50)=27.85 and 5.14 mg/L; LC(90)=71.45 and 25.68 mg/L) respectively. The chi-square value were significant at p<0.05 level. These results suggest that the synthesized AgNPs have the potential to be used as an ideal eco-friendly approach for the control of the Culex tritaeniorhynchus and A. subpictus. This method is considered as a new approach to control vectors. Therefore, this study provides first report on the mosquito larvicidal activity of synthesized AgNPs against vectors.


Assuntos
Anopheles/efeitos dos fármacos , Culex/efeitos dos fármacos , Eclipta/química , Inseticidas/farmacologia , Nanopartículas Metálicas , Extratos Vegetais/farmacologia , Prata/farmacologia , Animais , Larva/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Análise de Sobrevida
13.
Parasitol Res ; 108(6): 1447-55, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21153420

RESUMO

The purpose of the present study was to assess the effect of crude extracts of marine actinobacteria on larvicidal, repellent, and ovicidal activities against Culex tritaeniorhynchus and Culex gelidus (Diptera: Culicidae). The early fourth instar larvae of C. tritaeniorhynchus and C. gelidus, reared in the laboratory, were used for larvicidal, ovicidal, and repellent assay with crude extracts of actinobacteria. Saccharomonospora spp. (LK-1), Streptomyces roseiscleroticus (LK-2), and Streptomyces gedanensis (LK-3) were identified as potential biocide producers. Based on the antimicrobial activity, three strains were chosen for larvicidal activity. The marine actinobacterial extracts showed moderate to high larvicidal effects after 24 h of exposure at 1,000 ppm and the highest larval mortality was found in extract of LK-3 (LC(50) = 108.08 ppm and LC(90) = 609.15 ppm) against the larvae of C. gelidus and (LC(50) = 146.24 ppm and LC(90) = 762.69 ppm) against the larvae of C. tritaeniorhynchus. Complete protections for 240 min were found in crude extract of LK-2 and LK-3 at 1,000 ppm, against mosquito bites of C. tritaeniorhynchus and C. gelidus, respectively. After 24-h treatment, mean percent hatchability of the ovicidal activity was observed. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. Crude extracts of LK-1 and LK-3 showed no hatchability at 1,000 ppm against C. tritaeniorhynchus and C. gelidus, respectively. This is an ideal ecofriendly approach for the control of Japanese encephalitis vectors, C. tritaeniorhynchus and C. gelidus.


Assuntos
Actinobacteria/química , Organismos Aquáticos/química , Culex/efeitos dos fármacos , Aedes/efeitos dos fármacos , Animais , Anopheles/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Insetos Vetores/efeitos dos fármacos , Inseticidas/farmacologia , Larva/efeitos dos fármacos
14.
Trop Biomed ; 27(2): 143-54, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20962710

RESUMO

Mosquitoes transmit serious human diseases, causing millions of deaths every year. Use of synthetic insecticides to control vector mosquitoes has caused physiological resistance and adverse environmental effects in addition to high operational cost. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. The present investigations were made to evaluate the repellent, ovicidal and oviposition-deterrent potential of leaf hexane and chloroform extracts of Aegle marmelos, Andrographis lineata, Andrographis paniculata, Cocculus hirsutus, Eclipta prostrata and Tagetes erecta against Anopheles subpictus Grassi (Diptera:Culicidae). The hexane extract of A. lineata was more effective in exhibiting the repellent action against the mosquito as compared with A. marmelos extract. Complete protections for 150 min were found in hexane extract of A. lineata at 500 ppm against An. subpictus bites. Mean percent hatchability of the ovicidal activity was observed 24 h after treatment. The percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. No hatchability was observed with hexane and chloroform extracts of A. lineata, A. paniculata and hexane extract of T. erecta were exerted at 1,000 ppm. The percentage of effective oviposition repellency of 93.07, 93.95, 98.03, 90.43, 92.63, 81.53, 94.81, 97.50, 97.26, 92.22, 82.85 and 72.77 at 500 ppm and the lowest repellency of 62.03, 53.64, 73.47, 59.05, 57.95, 48.17, 62.22, 72.99, 75.48, 67.77, 40.57 and 52.11 at 31.25 ppm in hexane and chloroform extracts of A. marmelos, A. lineata, A. paniculata, C. hirsutus, E. prostrata and T. erecta, respectively. The oviposition activity index (OAI) values revealed that the solvent plant extracts have deterrent effect, and they caused a remarkable negative response resulting in oviposition of very few eggs. These results clearly reveal that the hexane extract of A. lineata, served as a potential repellent, ovicidal and oviposition- deterrent against An. subpictus.


Assuntos
Anopheles/efeitos dos fármacos , Repelentes de Insetos/farmacologia , Inseticidas/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Animais , Repelentes de Insetos/química , Insetos Vetores/efeitos dos fármacos , Inseticidas/química , Malária/transmissão , Óvulo/efeitos dos fármacos
15.
Trop Biomed ; 27(2): 211-9, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20962718

RESUMO

Mosquitoes transmit serious human diseases, causing millions of deaths every year. Natural products of plant origin with insecticidal properties have been used in recent years for control of a variety of pest insects and vectors. The present study was based on assessments of the larvicidal activity to determine the efficacies of hexane, chloroform, ethyl acetate, acetone and methanol extracts of ten medicinal plants tested against fourth instar larvae of malaria vector, Anopheles stephensi Liston and lymphatic filariasis vector, Culex quinquefasciatus Say (Diptera: Culicidae). The larvicidal activity was assessed by the procedure of WHO with some modification. The highest larval mortality was found in leaf acetone of Adhatoda vasica, bark ethyl acetate of Annona squamosa, methanol leaf and flower of Cassia auriculata, leaf ethyl acetate of Hydrocotyle javanica, methanol leaf and seed of Solanum torvum and leaf hexane extracts of Vitex negundo against the fourth instar larvae of An. stephensi and Cx. quinquefasciatus. The calculated LC90 for acetone, ethyl acetate, methanol and hexane extracts of dried leaf and bark of A. vasica, A. squamosa, S. torvum, and V. negundo were in the range of 70.38-210.68 ppm. Our results suggest that the leaf methanol extract of S.torvum and bark ethyl acetate extract of A. squamosa from Southern India have the potential for use to control mosquitoes. Therefore, this study provides the larvicidal activity against An. stephensi and Cx. quinquefasciatus of plant extracts.


Assuntos
Anopheles/efeitos dos fármacos , Culex/efeitos dos fármacos , Inseticidas/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Relação Dose-Resposta a Droga , Larva/efeitos dos fármacos , Extratos Vegetais/química
16.
Colloids Surf B Biointerfaces ; 79(2): 334-9, 2010 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-20483569

RESUMO

The present study demonstrates hexavalent chromium reduction and trivalent chromium tolerance behavior of marine Bacillus sp., MTCC 5514 through its extracellular enzyme reductase and biosurfactants production. The isolate reduces 10-2000 mg/L of hexavalent chromium to trivalent chromium with in 24-96 h respectively and the release of extracellular chromium reductase, found responsible for the reduction. Upon reduction, the concentration of trivalent chromium in the medium found comparatively less. Experimental results reveal, biosurfactants activity found responsible for the less concentration of Cr(III). Hypothetically, trivalent chromium upon formation get entrapped in the micelle of biosurfactants, prevents microbial cells from exposure towards trivalent chromium. Thus, the chosen isolate exhibit tolerance and growth with the increasing concentration of chromium.


Assuntos
Bactérias/enzimologia , Espaço Extracelular/enzimologia , Metais Pesados/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Oxirredutases/metabolismo , Água do Mar/microbiologia , Tensoativos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Cromo/metabolismo , Espaço Extracelular/efeitos dos fármacos , Oxirredução/efeitos dos fármacos
17.
Colloids Surf B Biointerfaces ; 78(2): 200-7, 2010 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-20359870

RESUMO

The present study demonstrates in situ formation of multilamellar stable vesicles (MLSVs) of fatty acids released during the growth of microorganisms in the presence of triglycerides. Release of lipase during initial phase of growth hydrolyzes the triglycerides and release free fatty acids (mono or diglycerides) and glycerol. By extending the growth and the prevailing composition of media (unspent nutrients, salts, pH of the medium, biosurfactants, fatty acids, glycerol) and agitation transforms free fatty acids to MLSV of both cylindrical and spherical macroscopic structures via micelle formation with in 240h of incubation. Cross-sectional view and SEM analysis of macroscopic structures reveal the existence of continuous multilayering. Thermo-gravimetric analysis illustrates the stability of the vesicles. FT-IR analysis emphasizes the presence of amide linkages, responsible for self-assembly processes. Schematic representation of formation of MLSV demonstrated for further understanding. Additional exploration on MLSV formation in arteries and the relationship between MLSV and in situ plaque formation by the components of blood in the arteries are schematically explained and submitted as supporting information (SI-2).


Assuntos
Bacillus/química , Ácidos Graxos não Esterificados/química , Tensoativos/química , Triglicerídeos/química , Bacillus/metabolismo , Bacillus/ultraestrutura , Proteínas de Bactérias/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/metabolismo , Lipossomos/química , Lipossomos/metabolismo , Lipossomos/ultraestrutura , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos/metabolismo , Termogravimetria , Triglicerídeos/metabolismo
18.
Indian J Exp Biol ; 47(12): 964-8, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20329699

RESUMO

A proteobacterium isolated from coastal region of Chennai, India, produced appreciable secondary metabolite and partial purification of the obtained secondary metabolite demonstrated antimicrobial activity against both Gram positive and negative organisms including MRSA (methicillin resistant Staphylococcus aureus). Identification of the isolate using biochemical tests, 16s rDNA sequence analysis, G+C content and electron microscopy studies revealed, isolate belonged to Pseudomonas genera. Extraction, purification, characterization and antimicrobial activity of secondary metabolite carried out using various standard instrumental techniques suggested that the active fraction was of 272 m/z with a stable fragment of 244 m/z and also displayed stable free radical activity assessed using EPR analysis. This stable free radical activity of secondary metabolite mediated its antimicrobial activity.


Assuntos
Antibacterianos/farmacologia , Radicais Livres/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Pseudomonas/metabolismo , Animais , Antibacterianos/biossíntese , Antibacterianos/química , Composição de Bases , DNA Ribossômico , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Biologia Marinha , Pseudomonas/química , RNA Ribossômico 16S , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia
19.
Colloids Surf B Biointerfaces ; 67(2): 192-8, 2008 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18829271

RESUMO

The present study demonstrates the role of microbial hydrolases in the transformation of hydrocarbons (soybean, sunflower, groundnut and gingelly oil, etc.) to vesicles. The combined effect of lipolytic enzyme generation and biosurfactants production during microbial growth at optimized media and environmental conditions mediates this transformation. Among the microbial species, Candida albicans exhibit complete transformation compared to Pseudomonads and Bacillus sps. Within hydrocarbons, only soybean and sunflower oils transformed to solid mass and no change with the remaining oils. Characterization of the vesicles revealed an increase in total weight by 160-180% compared to the original weight of hydrocarbon taken for the study and more than 73% increases in viscosity. Acid value and saponification value also showed an increase, respectively, by 78 and 84%. The bound water content estimated was 26%. Light microscopic analysis exhibit, presence of unilamellar and bi-lamellar structures.


Assuntos
Hidrocarbonetos/metabolismo , Hidrolases/metabolismo , Tensoativos/metabolismo , Bacillus/metabolismo , Candida albicans/metabolismo , Hidrocarbonetos/química , Óleos de Plantas/química , Óleos de Plantas/metabolismo , Pseudomonas/metabolismo , Viscosidade
20.
World J Microbiol Biotechnol ; 23(12): 1733-8, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27517829

RESUMO

Pseudomonas aeruginosa CLRI BL22 was able to degrade metanilic acid, a sulfonated aromatic amine upto a concentration of 1,500 mg l(-1). The degradation of metanilic acid started when the organism reached its exponential growth phase. Chromatographic and spectrophotometric analyses confirmed the presence of aniline and ß-keto adipic acid indicating the ortho pathway reaction. Further proof for this pathway was provided by dioxygenase activity of the strain grown in the medium containing metanilic acid and glucose.

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