RESUMEN
Emissions from thermal power plants have always been the central consideration for environmental protection. Existing optical sensors in thermal power plants usually measure the total mass concentration of the particulate matter (PM) by a single-wavelength laser, bearing intrinsic errors owing to the variation in particle size distribution (PSD). However, the total mass concentration alone cannot characterize all the harmful effects of the air pollution caused by the power plant. Therefore, it is necessary to measure the mass concentration and PSD simultaneously, based on which we can obtain multi-particle-size channel mass concentration. To achieve this, we designed an optical sensor based on the three-wavelength technique and tested its performance in a practical environment. Results showed that the prototype cannot only correctly measure the mass concentration of the emitted PM but also determine the mean diameter and standard deviation of the PSDs. Hence, the mass concentrations of PM10, PM2.5, and PM1 are calculated, and the air pollutants emission by a thermal power plant can be estimated comprehensively.
RESUMEN
Photoelectric smoke detectors are the most cost-effective devices for very early warning fire alarms. However, due to the different light intensity response values of different kinds of fire smoke and interference from interferential aerosols, they have a high false-alarm rate, which limits their popularity in Chinese homes. To address these issues, an embedded spatial-temporal convolutional neural network (EST-CNN) model is proposed for real fire smoke identification and aerosol (fire smoke and interferential aerosols) classification. The EST-CNN consists of three modules, including information fusion, scattering feature extraction, and aerosol classification. Moreover, a two-dimensional spatial-temporal scattering (2D-TS) matrix is designed to fuse the scattered light intensities in different channels and adjacent time slices, which is the output of the information fusion module and the input for the scattering feature extraction module. The EST-CNN is trained and tested with experimental data measured on an established fire test platform using the developed dual-wavelength dual-angle photoelectric smoke detector. The optimal network parameters were selected through extensive experiments, resulting in an average classification accuracy of 98.96% for different aerosols, with only 67 kB network parameters. The experimental results demonstrate the feasibility of installing the designed EST-CNN model directly in existing commercial photoelectric smoke detectors to realize aerosol classification.
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The relationship between the numerical of Sauter mean diameter (SMD) and aerosol distribution parameters, as well as its physical significance are lacking in detailed research. Meanwhile, existing method is not widely used for SMD accurate measurement due to many restrictions on the incident light wavelengths. In this study, we analyzed the relationship between SMDs and the mean and median values of the lognormal, normal, and Weibull distributions with different parameters. It is found that SMD can be directly used to substitute the mean particle size in lognormal distributions with slight deviations. A new method for aerosol SMD measurement with no wavelength limitation based on the light scattering response of the combined volume-surface area of particles is proposed. SMD inversion results show that this method reduces the error caused by inconsistent integration of the wavelength of incident light and particle size in existing measurements, because has no limitation on the wavelength of incident light. SMDs of N-Heptane combustion smokes measured using the developed sensor indicates that our proposed SMD measurement method effectively compensates the shortcomings of the existing method and improves the measurement accuracy, with the minimum and average errors of 8.9% and 14.78%, respectively.
RESUMEN
The severe doxorubicin (DOXO) side effect of cardiomyopathy limits it clinical application as an effective anticancer drug. Although Ca2+ overload was postulated as one of the mechanisms for this toxicity, its role was, however, disputable in terms of the contractile dysfunction. In this work, the dynamics of the intracellular Ca2+ signal were optically mapped in a Langendorff guinea pig heart. We found that DOXO treatment: (1) Delayed the activation of the Ca2+ signal. With the reference time set at the peak of the action potential (AP), the time lag between the peak of the Ca2+ signal and AP (Ca-AP-Lag) was significantly prolonged. (2) Slowed down the intracellular Ca2+ releasing and sequestering process. Both the maximum rising (MRV) and falling (MFV) velocity of the Ca2+ signal were decreased. (3) Shortened the duration of the Ca2+ signal in one cycle of Ca2+ oscillation. The duration of the Ca2+ signal at 50% amplitude (CaD50) was significantly shortened. These results suggested a reduced level of intracellular Ca2+ after DOXO treatment. Furthermore, we found that the effect of tachypacing was similar to that of DOXO, and, interestingly, DOXO exerted contradictory effects on the tachypaced hearts: it shortened the Ca-AP-Lag, accelerated the MRV and MFV, and prolonged the CaD50. We, therefore, concluded that DOXO had a different effect on intracellular Ca2+. It caused Ca2+ underload in hearts with sinus rhythm; this might relate to the contractile dysfunction in DOXO cardiomyopathy. It led to Ca2+ overload in the tachypaced hearts, which might contribute to the Ca2+-overload-related toxicity.
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Malignant melanomas are amongst the most aggressive cancers. BRAF Inhibitors have exhibited therapeutic effects against BRAF-mutant melanoma. In continuation of our earlier studies on anti-melanoma agents based on 1H-pyrazole skeleton, two sets of novel compounds that include 1H-pyrazole-4-amines FA1 - FA13 and corresponding urea derivatives FN1 - FN13 have been synthesized and evaluated for their BRAFV600E inhibitory and antiproliferation activities. Compound FN10 displayed the most potent biological activity against BRAFV600E (IC50 = 0.066 µm) and the A375 human melanoma cell line (GI50 = 0.81 µm), which was comparable to the positive control vemurafenib, and more potent than our previously reported 1H-pyrazole-3-amines and their urea derivatives. The results of SAR studies and molecular docking can guide further optimization and may help to improve potency of these pyrazole-based anti-melanoma agents.
Asunto(s)
Antineoplásicos/farmacología , Melanoma/tratamiento farmacológico , Pirazoles/farmacología , Urea/farmacología , Antineoplásicos/síntesis química , Antineoplásicos/química , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Melanoma/patología , Simulación del Acoplamiento Molecular , Estructura Molecular , Pirazoles/síntesis química , Pirazoles/química , Relación Estructura-Actividad , Urea/químicaRESUMEN
The marine natural products (MNPs) isolated from seaweeds-associated microbial communities have received substantial attention owing to their exceptional nutritional and pharmacology application, such as antiviral, anticancer, antiprotozoal, antifungal, and antibacterial properties and so on. Particularly, there are several MNPs that have been displayed attractive value for the development of novel anticancer agents. This review covers the literature published in the recent 5 years on the novel anticancer MNPs discovered originating from seaweeds, and focused on the chemistry and relative anticancer activities of new MNPs which categorize their source organisms. These seaweed-derived MNPs are categorized based on their origin as brown algae, red algae, cyanobacteria, chlorophyta and others.