Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Sensors (Basel) ; 23(12)2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37420720

RESUMEN

Due to the characteristics of the cotton picker working in the field and the physical characteristics of cotton, it is easy to burn during the operation, and it is difficult to be detected, monitored, and alarmed. In this study, a fire monitoring system of cotton pickers based on GA optimized BP neural network model was designed. By integrating the monitoring data of SHT21 temperature and humidity sensors and CO concentration monitoring sensors, the fire situation was predicted, and an industrial control host computer system was developed to monitor the CO gas concentration in real time and display it on the vehicle terminal. The BP neural network was optimized by using the GA genetic algorithm as the learning algorithm, and the data collected by the gas sensor were processed by the optimized network, which effectively improved the data accuracy of CO concentration during fires. In this system, the CO concentration in the cotton box of the cotton picker was validated, and the measured value of sensor was compared with the actual value, which verified the effectiveness of the optimized BP neural network model with GA. The experimental verification showed that the system monitoring error rate was 3.44%, the accurate early warning rate was over 96.5%, and the false alarm rate and the missed alarm rate were less than 3%. In this study, the fire of cotton pickers can be monitored in real time and an early warning can be made in time, and a new method was provided for accurate monitoring of fire in the field operation of cotton pickers.


Asunto(s)
Algoritmos , Fibra de Algodón , Incendios , Agricultura , Monóxido de Carbono/química , Programas Informáticos , Temperatura
2.
Bioorg Chem ; 119: 105522, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34864279

RESUMEN

Six new lignans with various type of linkage between two C6-C3 fragments (1a, 1b, 2a, 2b, 3, 4), two new meroterpenoids (5, 6) and 24 known compounds (7-30) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of enantiomers 1a and 1b were determined by single-crystal X-ray diffraction analysis, 2a and 2b were determined by comparing their calculated and experimental ECD spectra. Biogenetically, all the new lignans may come from the polymerization of two molecules of hydroxychavicol (30). In the anti-neuroinflammation activity assay, the IC50 values of fifteen compounds were lower than those of the positive control minocycline, and compound 1a showed good activity, but its enantiomer 1b showed no activity. Compound 1a have notable anti-neuroinflammatory activity, and can significantly decrease mRNA levels of proinflammatory cytokines (IL-1ß, IL-6, TNF-α) in a dose-dependent manner.


Asunto(s)
Antiinflamatorios no Esteroideos/farmacología , Lignanos/farmacología , Óxido Nítrico/antagonistas & inhibidores , Piper/química , Extractos Vegetales/farmacología , Terpenos/farmacología , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/aislamiento & purificación , Línea Celular , Cristalografía por Rayos X , Citocinas/antagonistas & inhibidores , Citocinas/metabolismo , Relación Dosis-Respuesta a Droga , Lignanos/química , Lignanos/aislamiento & purificación , Ratones , Modelos Moleculares , Estructura Molecular , Óxido Nítrico/metabolismo , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , ARN Mensajero/antagonistas & inhibidores , ARN Mensajero/metabolismo , Estereoisomerismo , Relación Estructura-Actividad , Terpenos/química , Terpenos/aislamiento & purificación
3.
J Nat Prod ; 84(4): 1316-1325, 2021 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-33822610

RESUMEN

Three new tyramine-type alkamides (1-3), three new natural products (4-6), five new N-acylated/formylated aporphine alkamides with different ratios of rotational isomers (7-11), and 20 known alkamides (12-31) were isolated from an EtOH extract of the stems and leaves of Piper puberulum. The absolute configurations of compounds 7, 8, and 10 were determined by single-crystal X-ray diffraction analysis. In the biological activity assay, compounds 3, 5, and 10-23 displayed inhibitory effects against lipopolysaccharide-induced NO release in BV-2 microglial cells, exhibiting IC50 values of 0.93-45 µM.


Asunto(s)
Aporfinas/farmacología , Microglía/efectos de los fármacos , Piper/química , Tiramina/farmacología , Animales , Aporfinas/aislamiento & purificación , Línea Celular , China , Ratones , Estructura Molecular , Óxido Nítrico , Fitoquímicos/aislamiento & purificación , Fitoquímicos/farmacología , Hojas de la Planta/química , Tallos de la Planta/química , Tiramina/aislamiento & purificación
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA