Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Heliyon ; 9(10): e20724, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37867881

RESUMO

Chitosan is a naturally occurring linear biopolymer made of partially deacetylated acetyl and N-acetyl glucosamine. Its biocompatible physiochemical and biochemical properties are unmatched. Chitosan is transformed to nanopowder for use in agriculture and associated industries as nanocarriers for existing agrochemicals, ensuring the delayed release of chemicals with better solubility. Chitosan nanopowder applied to leaves or soil can activate a plant's natural defences against insects and pathogens. These studies were carried out because there is a potential for toxicological risk linked with products created utilizing nanotechnology, such as chitosan nanopowder, and therefore researchers felt the need to investigate this. The egg parasitoides Trichogramma Japonicum Ashmead was used as a low-cost biomarker to determine the potential toxicity of chitosan nanopowder. This study looked into the possibility that the adult stage of the egg parasitoids, Trichogramma Japonicum Ashmead might be negatively impacted by chitosan nanopowder (80-100 nm). Unpaired t-test statistical analysis has been carried out. According to the statistical analysis, host eggs exposed to chitosan nanopowder showed noticeably greater parasitization than the control group. As a natural supply of carbohydrate polymers chitosan nanopowder promotes the parasitization of T. Japonicum. The findings showed that T. Japonicum favoured chitosan nanopowder. Through Y dual choice, eight-arm multiple choice, and no-choice olfactometer experiments, as well as images from a stereozoom microscope and a scanning electron microscope (SEM), the data was thoroughly supported. Future agricultural applications of chitosan nanopowder will benefit from a deeper understanding of our findings.

2.
Biosens Bioelectron ; 173: 112728, 2020 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-33220535

RESUMO

Olive oil is more preferred than other vegetable oils because of the increasing health concern among people throughout the world. The major hindrance in large-scale production of olive oil is olive fruit pests which cause serious economic damage to the olive orchards. This requires careful monitoring and timely application of suitable remedies before pest infestation. Herein we demonstrate efficacious utilization of covalently functionalized ß-cyclodextrinylated MEMS devices for selective and sensitive detection of female sex pheromone of olive fruit pest, Bactocera oleae. Two of the MEMS devices, silicon dioxide surface-micromachined cantilever arrays and zinc oxide surface-microfabricated interdigitated circuits, have been used to selectively capture the major pheromone component, 1,7-dioxaspiro[5,5]undecane. The non-covalent capture of olive pheromones inside the ß-cyclodextrin cavity leads to the reduction of resonant frequency of the cantilevers, whereas an increase in resistance has been found in case of zinc oxide derived MEMS devices. Sensitivity of the MEMS devices towards the olive pheromone was found to be directly correlated with the increasing availability of ß-cyclodextrin moieties over the surface of the devices and thus the detection limit of the devices has been achieved to a value as low as 0.297 ppq of the olive pheromone when the devices were functionalized with one of the standardized protocols. Overall, the reversible usability and potential capability of the suitably functionalized MEMS devices to selectively detect the presence of female sex pheromone of olive fruit fly before the onset of pest infestation in an orchard makes the technology quite attractive for viable commercial application.

3.
Int J Biol Macromol ; 145: 226-234, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31866543

RESUMO

We, herein, report the effect of chitosan nanofertilizer comprising of copper (Cu) and salicylic acid (SA) on source activity in maize. Seed treatment and foliar application of chitosan nanofertilizer significantly up-regulated the source activity in developing maize plants. Seed treatment with nanofertilizer induced 1.6 folds higher seedling vigour index, 1.7-3.0 folds higher activities of reserve food mobilizing enzymes in seedlings as compared with control. Foliar application of nanofertilizer (0.01-0.16%) statistically significantly increased the activities of antioxidant enzymes (1.06-1.91 folds), reduced malondialdehyde content and enhanced chlorophyll contents (2 folds) in leaves. Application of nanofertilizer remarkably induced sucrose translocation (2.5-3.5 folds) in internodes which gives subtle clue of higher remobilization of nutrients towards growing cob. The elusive bioactivities of nanofertilizer can be attributed to slow release and synergistic effects of Cu and SA. We claim that chitosan nanofertilizer has immense potential to promote source activity in maize for higher crop yield.


Assuntos
Quitosana/química , Cobre/farmacologia , Nanoestruturas/química , Ácido Salicílico/farmacologia , Plântula/efeitos dos fármacos , Sementes/efeitos dos fármacos , Zea mays/efeitos dos fármacos , Transporte Biológico/efeitos dos fármacos , Catalase/metabolismo , Produtos Agrícolas , Fertilizantes/análise , Malondialdeído/antagonistas & inibidores , Malondialdeído/metabolismo , Nanoestruturas/ultraestrutura , Peroxidase/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Sacarose/metabolismo , Superóxido Dismutase/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
4.
Plant Physiol Biochem ; 145: 64-74, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31665668

RESUMO

Herein, we report zinc-functionalized thymol nanoemulsion (Zn-TNE) by sonication method and its characterization by DLS, HR-TEM, FEG-SEM-EDS, Cryo-FESEM, FTIR and AAS studies. Zn-TNE treated seeds bestowed better seedling vigor index and higher activities of seed stored food mobilizing enzymes (α-amylase and protease). Foliar application of Zn-TNE (0.01-0.06%, v/v) enhanced defense-antioxidant enzymes activities, balanced reactive oxygen species, induced higher content of chlorophyll-a, b and higher lignin deposition in soybean plants. In the field, Zn-TNE application (0.02-0.06%, v/v) significantly controlled bacterial pustule disease (PEDC value 28-79%) and increased grain yield up to 16.6% as compared with bulk thymol application and up to 50% from control. Disease control and higher yield in soybean could be explained by diverse bioactivities of Zn-TNE in maintaining cellular homeostasis of soybean plants. Study shows that Zn-TNE can further be maneuvered for slow delivery of other micronutrients for higher crop yield.


Assuntos
Produção Agrícola , Glycine max , Timol , Zinco , Produção Agrícola/métodos , Sementes/efeitos dos fármacos , Glycine max/efeitos dos fármacos , Glycine max/fisiologia , Timol/farmacologia , Zinco/farmacologia
5.
Chem Asian J ; 12(1): 76-85, 2017 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-27925415

RESUMO

Red-light-emitting water-soluble semiconducting quantum dots (QDs) were synthesized by using a wide variety of commercially available thiol-type capping agents. QDs with a negatively charged nanosurface showed excellent selectivity for paraquat (PQ) at pH 7.4 over other commonly encountered pesticides/herbicides, including diquat (DQ). The presence of a 4,4'-bis-pyridinium unit in PQ enabled it to initiate long-range aggregation, thereby leading to the formation of nanostructures with excellent emission-quenching behavior. Precoated quartz plates were developed as a low-cost, portable sensor for the on-site detection of PQ in both natural water and human urine. Estimation of the PQ concentration was performed in different commercial formulations and the detection of PQ contamination in adulterated dairy product was also achieved with excellent sensitivity. Finally, we screened more than 50 different food items, including vegetables, fruits, cereals, and fodders, to construct a generalized marker for any residual PQ in such specimens.


Assuntos
Compostos de Cádmio/química , Produtos Agrícolas/química , Análise de Alimentos , Contaminação de Alimentos/análise , Herbicidas/análise , Luz , Nanopartículas/química , Telúrio/química , Compostos de Cádmio/síntese química , Tamanho da Partícula , Propriedades de Superfície
6.
Sci Rep ; 6: 37355, 2016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-27892521

RESUMO

Plant pests exert serious effects on food production due to which the global crop yields are reduced by ~20-40 percent per year. Hence to meet the world's food needs, loses of food due to crop pests must be reduced. Herein the silicon dioxide based MEMS devices are covalently functionalized for robust and efficient optical sensing of the female sex pheromones of the pests like Helicoverpa armigera for the first time in literature. The functionalized devices are also capable of selectively measuring the concentration of this pheromone at femtogram level which is much below the concentration of pheromone at the time of pest infestation in an agricultural field. Experiments are also performed in a confined region in the presence of male and female pests and tomato plants which directly mimics the real environmental conditions. Again the reversible use and absolutely trouble free transportation of these pheromone nanosensors heightens their potentials for commercial use. Overall, a novel and unique approach for the selective and reversible sensing of female sex pheromones of certain hazardous pests is reported herein which may be efficiently and economically carried forward from the research laboratory to the agricultural field.


Assuntos
Aldeídos/análise , Bioengenharia/métodos , Dispositivos Ópticos , Atrativos Sexuais/análise , Aldeídos/química , Animais , Bioengenharia/instrumentação , Reagentes de Ligações Cruzadas/química , Feminino , Limite de Detecção , Solanum lycopersicum/parasitologia , Masculino , Mariposas/fisiologia , Compostos de Organossilício/química , Propilaminas/química , Atrativos Sexuais/biossíntese , Atrativos Sexuais/metabolismo , Silanos/química , Dióxido de Silício/química , Succinimidas/química
7.
Sci Rep ; 3: 1294, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23416455

RESUMO

Environment-friendly management of fruit flies involving pheromones is useful in reducing the undesirable pest populations responsible for decreasing the yield and the crop quality. A nanogel has been prepared from a pheromone, methyl eugenol (ME) using a low-molecular mass gelator. This was very stable at open ambient conditions and slowed down the evaporation of pheromone significantly. This enabled its easy handling and transportation without refrigeration, and reduction in the frequency of pheromone recharging in the orchard. Notably the involvement of the nano-gelled pheromone brought about an effective management of Bactrocera dorsalis, a prevalent harmful pest for a number of fruits including guava. Thus a simple, practical and low cost green chemical approach is developed that has a significant potential for crop protection, long lasting residual activity, excellent efficacy and favorable safety profiles. This makes the present invention well-suited for pest management in a variety of crops.


Assuntos
Frutas/parasitologia , Controle de Insetos , Feromônios/química , Polietilenoglicóis/química , Polietilenoimina/química , Animais , Eugenol/análogos & derivados , Eugenol/química , Eugenol/toxicidade , Nanogéis , Feromônios/toxicidade , Psidium/parasitologia , Temperatura , Tephritidae/efeitos dos fármacos
8.
Acta Crystallogr C ; 59(Pt 8): o409-12, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12909762

RESUMO

The crystal structure of 4,6-bis(methylsulfanyl)-1-phthalimidopropyl-1H-pyrazolo[3,4-d]pyrimidine, C(18)H(17)N(5)O(2)S(2), (VI), reveals an unusual folded conformation due to an apparent intramolecular C-H.pi interaction between the 6-methylsulfanyl and phenyl groups. However, the closely related compound 6-methylsulfanyl-1-phthalimidopropyl-4-(pyrrolidin-1-yl)-1H-pyrazolo[3,4-d]pyrimidine, C(21)H(22)N(6)O(2)S, (VII), exhibits a fully extended structure, devoid of any intramolecular C-H.pi or pi-pi interactions. The crystal packing of both molecules involves intermolecular stacking interactions due to aromatic pi-pi interactions. In addition, (VI) exhibits intermolecular C-H.O hydrogen bonding and (VII) exhibits dimerization of the molecules through intermolecular C-H.N hydrogen bonding.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA