Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Hazard Mater ; 472: 134537, 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38759279

RESUMO

Experimental studies assessed the removal efficiency and fine-size distribution of CPM coupled with compositional analysis across air pollution control device systems (APCDs) at an ultra-low emission (ULE) power plant. The findings indicated total CPM emissions were reduced to a minimum of 0.418 mg/m3 at the Wet Electrostatic Precipitator (WESP). The Wet Flue Gas Desulfurization (WFGD) showed the highest removal efficiency (98%) across all particle sizes, notably in the ultra-micron range. Selective Catalytic Reduction (SCR) demonstrated a mere 34% overall efficiency, with a negative removal rate in the ultra-fine particle range. The WESP effectively removed CPM only in sub-micron and ultra-micron sizes, but significantly increased water-soluble ions formation in ultra-fine spatially suspended CPM (CPMspa), leading to overall negative efficiency. Thus, the removal efficiency of the ultra-fine particle range was most affected among the three particle size ranges when the flue gas went through the APCDs. Major metal elements and water-soluble ions were more readily removed by APCDs due to their surface aggregation, while the removal of trace elements like Hg and Se was limited. Reducing SO42-/NH4+ formation in SCR, and optimizing WESP spray system operations based on flue gas components are essential steps in controlling CPM concentration in ULE power plants.

2.
Front Plant Sci ; 14: 1227011, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37521914

RESUMO

Plant diseases and pests have always been major contributors to losses that occur in agriculture. Currently, the use of deep learning-based convolutional neural network models allows for the accurate identification of different types of plant diseases and pests. To enable more efficient identification of plant diseases and pests, we design a novel network architecture called Dise-Efficient based on the EfficientNetV2 model. Our experiments demonstrate that training this model using a dynamic learning rate decay strategy can improve the accuracy of plant disease and pest identification. Furthermore, to improve the model's generalization ability, transfer learning is incorporated into the training process. Experimental results indicate that the Dise-Efficient model boasts a compact size of 13.3 MB. After being trained using the dynamic learning rate decay strategy, the model achieves an accuracy of 99.80% on the Plant Village plant disease and pest dataset. Moreover, through transfer learning on the IP102 dataset, which represents real-world environmental conditions, the Dise-Efficient model achieves a recognition accuracy of 64.40% for plant disease and pest identification. In light of these results, the proposed Dise-Efficient model holds great potential as a valuable reference for the deployment of automatic plant disease and pest identification applications on mobile and embedded devices in the future.

3.
Sensors (Basel) ; 22(19)2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36236507

RESUMO

In the light field image saliency detection task, redundant cues are introduced due to computational methods. Inevitably, it leads to the inaccurate boundary segmentation of detection results and the problem of the chain block effect. To tackle this issue, we propose a method for salient object detection (SOD) in light field images that fuses focus and GrabCut. The method improves the light field focus calculation based on the spatial domain by performing secondary blurring processing on the focus image and effectively suppresses the focus information of out-of-focus areas in different focus images. Aiming at the redundancy of focus cues generated by multiple foreground images, we use the optimal single foreground image to generate focus cues. In addition, aiming at the fusion of various cues in the light field in complex scenes, the GrabCut algorithm is combined with the focus cue to guide the generation of color cues, which realizes the automatic saliency target segmentation of the image foreground. Extensive experiments are conducted on the light field dataset to demonstrate that our algorithm can effectively segment the salient target area and background area under the light field image, and the outline of the salient object is clear. Compared with the traditional GrabCut algorithm, the focus degree is used instead of artificial Interactively initialize GrabCut to achieve automatic saliency segmentation.


Assuntos
Algoritmos , Sinais (Psicologia)
4.
Comput Math Methods Med ; 2022: 9241959, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35096137

RESUMO

BACKGROUND: Abdominal aortic aneurysm (AAA) belongs to a progressive, gradual aortic rupture, which can lead to death without surgical intervention. The key factors regulating the occurrence and progress of AAA are not clear. Increasing studies have indicated that microRNA (miRNA) plays an important role in cancer development. miR-124a serves as a tumor suppressor in several neoplasms, and its upregulation can greatly inhibit the life activities such as malignant growth and migration of tumor cells. AIM: The objective of this study is to explore the association of miR-124a with AAA and to uncover the regulated mechanism of miR-124a on AAA progression. METHODS: The specimens from the AAA patients were used for observing the miR-124a expression, and human aortic endothelial cells (hAoECs) were treated with AngII to establish the AAA cell models. The quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), CCK-8, transwell assay, flow cytometry assay, and western blot were conducted to unearth the regulation mechanism of miR-124a on AAA, and the dual-luciferase reporter assay was employed to investigate the downstream target of miR-124a. RESULTS: miR-124a was significantly downregulated in the whole blood of the patients, and the decreased miR-124a was also observed in AAA cell models. Overexpressing miR-124a could effectively inhibit the proliferation and migration and promote the apoptosis of the AAA cells. The dual-luciferase reporter assay confirmed that BRD4 was a downstream target of miR-124a, and BRD4 upregulation could obviously reverse the effects of miR-124a on the phenotype of AAA cells. Moreover, it was found that miR-124a could regulate the activities of Wnt/ß-catenin and P53 pathways via targeting the BRD4. CONCLUSION: Our data suggested that miR-124a could regulate the activities of Wnt/ß-catenin and P53 to suppress the AAA progression via targeting the BRD4.


Assuntos
Aneurisma da Aorta Abdominal/genética , Proteínas de Ciclo Celular/antagonistas & inibidores , MicroRNAs/genética , Fatores de Transcrição/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Aneurisma da Aorta Abdominal/metabolismo , Aneurisma da Aorta Abdominal/prevenção & controle , Proteínas de Ciclo Celular/genética , Movimento Celular/genética , Proliferação de Células/genética , Células Cultivadas , Biologia Computacional , Progressão da Doença , Regulação para Baixo , Células Endoteliais/metabolismo , Regulação da Expressão Gênica , Genes Supressores de Tumor , Humanos , MicroRNAs/metabolismo , Modelos Cardiovasculares , Fatores de Transcrição/genética , Regulação para Cima
5.
Sensors (Basel) ; 23(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36616724

RESUMO

Most of the traditional image feature point extraction and matching methods are based on a series of light properties of images. These light properties easily conflict with the distinguishability of the image features. The traditional light imaging methods focus only on a fixed depth of the target scene, and subjects at other depths are often easily blurred. This makes the traditional image feature point extraction and matching methods suffer from a low accuracy and a poor robustness. Therefore, in this paper, a light field camera is used as a sensor to acquire image data and to generate a full-focus image with the help of the rich depth information inherent in the original image of the light field. The traditional ORB feature point extraction and matching algorithm is enhanced with the goal of improving the number and accuracy of the feature point extraction for the light field full-focus images. The results show that the improved ORB algorithm extracts not only most of the features in the target scene but also covers the edge part of the image to a greater extent and produces extracted feature points which are evenly distributed for the light field full-focus image. Moreover, the extracted feature points are not repeated in a large number in a certain part of the image, eliminating the aggregation phenomenon that exists in traditional ORB algorithms.


Assuntos
Algoritmos , Reconhecimento Automatizado de Padrão , Humanos , Reconhecimento Automatizado de Padrão/métodos
6.
Sensors (Basel) ; 21(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34451006

RESUMO

Garlic is one of the main economic crops in China. Accurate and timely extraction of the garlic planting area is critical for adjusting the agricultural planting structure and implementing rural policy actions. Crop extraction methods based on remote sensing usually use spectral-temporal features. Still, for garlic extraction, most methods simply combine all multi-temporal images. There has been a lack of research on each band's function in each multi-temporal image and optimal bands combination. To systematically explore the potential of the multi-temporal method for garlic extraction, we obtained a series of Sentinel-2 images in the whole garlic growth cycle. The importance of each band in all these images was ranked by the random forest (RF) method. According to the importance score of each band, eight different multi-temporal combination schemes were designed. The RF classifier was employed to extract garlic planting area, and the accuracy of the eight schemes was compared. The results show that (1) the Scheme VI (the top 39 bands in importance score) achieved the best accuracy of 98.65%, which is 6% higher than the optimal mono-temporal (February, wintering period) result, and (2) the red-edge band and the shortwave-infrared band played an essential role in accurate garlic extraction. This study gives inspiration in selecting the remotely sensed data source, the band, and phenology for accurately extracting garlic planting area, which could be transferred to other sites with larger areas and similar agriculture structures.


Assuntos
Alho , Tecnologia de Sensoriamento Remoto , Agricultura , Produtos Agrícolas , Estações do Ano
7.
Exp Ther Med ; 20(6): 221, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33193836

RESUMO

Rupture of abdominal aortic aneurysm (AAA) is a devastating event that can be prevented by inhibiting the growth of small aneurysms. Therapeutic strategies targeting certain events that promote the development of AAA must be developed, in order to alter the course of AAA. Chronic inflammation of the aortic mural is a major characteristic of AAA and is related to AAA formation, development and rupture. Daphnetin (DAP) is a coumarin derivative with anti-inflammatory properties that is extracted from Daphne odora var. However, the effect of DAP on AAA development remains unclear. The present study investigated the effect of DAP on the formation and development of experimental AAAs and its potential underlying mechanisms. A mice AAA model was established by intra-aortic infusion of porcine pancreatic elastase (PPE), and mice were intraperitoneally injected with DAP immediately after PPE infusion. The maximum diameter of the abdominal aorta was measured by ultrasound system, and aortic mural changes were investigated by Elastica van Gieson (EVG) staining and immunohistochemical staining. The results demonstrated that DAP significantly suppressed PPE-induced AAA formation and attenuated the depletion of aortic medial elastin and smooth muscle cells in the media of the aorta. Furthermore, the density of mural macrophages, T cells and B cells were significantly attenuated in DAP-treated AAA mice. In addition, treatment with DAP resulted in a significant reduction in mural neovessels. These findings indicated that DAP may limit the formation and progression of experimental aneurysms by inhibiting mural inflammation and angiogenesis. These data confirmed the translational potential of DAP inclinical AAA inhibition strategies.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31689921

RESUMO

Air pollution, including particulate matter (PM2.5) pollution, is extremely harmful to the environment as well as human health. The Beijing-Tianjin-Hebei (BTH) Region has experienced heavy PM2.5 pollution within China. In this study, a six-year time series (January 2013-December 2018) of PM2.5 mass concentration data from 102 air quality monitoring stations were studied to understand the spatio-temporal variation characteristics of the BTH region. The average annual PM2.5 mass concentration in the BTH region decreased from 98.9 µg/m3 in 2013 to 64.9 µg/m3 in 2017. Therefore, China has achieved its Air Pollution Prevention and Control Plan goal of reducing the concentration of fine particulate matter in the BTH region by 25% by 2017. The PM2.5 pollution in BTH plain areas showed a more significant change than mountains areas, with the highest PM2.5 mass concentration in winter and the lowest in summer. The results of spatial autocorrelation and cluster analyses showed that the PM2.5 mass concentration in the BTH region from 2013-2018 showed a significant spatial agglomeration, and that spatial distribution characteristics were high in the south and low in the north. Changes in PM2.5 mass concentration in the BTH region were affected by both socio-economic factors and meteorological factors. Our results can provide a point of reference for making PM2.5 pollution control decisions.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental , China , Monitoramento Ambiental/métodos , Inquéritos Epidemiológicos , Humanos , Material Particulado/análise , Estações do Ano
9.
Biochem Biophys Res Commun ; 505(1): 282-289, 2018 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-30245136

RESUMO

Thromboangiitis obliterans (TAO), also known as Buerger's disease, is a nonatherosclerotic inflammatory disease that influences medium- and small-sized blood vessels of extremities. However, mechanisms underlying TAO are still unclear. As a mediator associated with inflammation, A disintegrin and metalloprotease 10 (ADAM10) was hypothesized to play inhibitory roles in the development of TAO. Thus, the objective of this study is to investigate the effects of ADAM10 in a sodium laurate-induced TAO rat model and elucidate underlying mechanisms. Male Wistar rats were randomly divided into four groups (n = 6) for treatment: sham-operated (SHAM), TAO model (TAO), ADAM10 low dose injection (3 mg/kg; ADAM10-LD) and ADAM10 high dose injection (6 mg/kg; ADAM10-HD). After 14-day treatment, color Doppler ultrasound and hematology analysis indicated TAO rats displayed higher whole blood viscosity and blood platelet count compared with those in the SHAM group. Histologic evaluation and transmission electron microscopy revealed that the ultrastructural damages of vascular smooth muscle and endothelial cells were observed in TAO rats, such as fractured endoplasmic reticulum, decreased cell counts, and fibrillation. On the other hand, the typical signs and symptoms of TAO rats were significantly alleviated via ADAM10 treatment with a dose-dependent pattern. Real-time PCR and western blot results revealed that the expression of high-mobility-group box 1 (HMGB1), receptor for advanced glycation end-products (RAGE) and nuclear factor-kappa B (NF-κB) increased in TAO rats whereas decreased by ADAM10 treatment in both mRNA and protein levels. In conclusion, the results suggest ADAM10 alleviates symptoms of sodium laurate-induced TAO in rats via the RAGE/NF-κB signaling pathway and provides insight into the molecular basis and a potential therapeutic strategy for TAO.


Assuntos
Proteína ADAM10/farmacologia , Proteína HMGB1/metabolismo , NF-kappa B/metabolismo , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Tromboangiite Obliterante/prevenção & controle , Proteína ADAM10/administração & dosagem , Animais , Viscosidade Sanguínea/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Células Endoteliais/ultraestrutura , Proteína HMGB1/genética , Ácidos Láuricos , Masculino , Microscopia Eletrônica de Transmissão , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Músculo Liso Vascular/ultraestrutura , NF-kappa B/genética , Contagem de Plaquetas , Ratos Wistar , Receptor para Produtos Finais de Glicação Avançada/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Tromboangiite Obliterante/sangue , Tromboangiite Obliterante/induzido quimicamente
10.
Cancer Biomark ; 22(3): 487-493, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29843213

RESUMO

BACKGROUND: Breast cancer remains the most invasive female malignancy worldwide. Functional role of microRNA-940 (miR-940) have been investigated in various cancer. The purpose of this study was to assess the serum miR-940 expression and its clinical significance in breast cancer. METHODS: Expression of miR-940 was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic value of miR-940 was analyzed with receiver operating characteristics (ROC) analysis. To explore the prognostic performance of miR-940, Kaplan-Meier survival assay and Cox regression analysis were performed. RESULTS: Downregulated miR-940 was detected in the breast cancer patients compared with the healthy controls (P< 0.001). The miR-940 expression was correlated with lymph node metastasis (P= 0.014) and TNM stage (P= 0.003). The area under the ROC curve (AUC) was 0.905, with sensitivity and specificity of 94.5% and 78.6%. From the survival curves, patients with low miR-940 expression had poor overall survival compare with those with high expression (log-rank P= 0.009). The Cox analysis indicated that miR-940 was an independent prognostic factor (HR = 2.645, 95% CI = 1.426-4.906 and P= 0.002). Decreased miR-940 expression was also been found in triple-negative breast cancer (TNBC) samples, and might predict poor prognosis in TNBC patients. CONCLUSIONS: Serum downregulated miR-940 may serve as a reliable diagnostic and prognostic biomarker in breast cancer patients.


Assuntos
Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , MicroRNAs/genética , Adulto , Idoso , Área Sob a Curva , Neoplasias da Mama/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Modelos de Riscos Proporcionais , Curva ROC
11.
J Anal Methods Chem ; 2013: 682134, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24027654

RESUMO

Water-soluble fluorescent conjugated polymer is a promising material which could be used as an optical platform in highly sensitive molecular sensors. In this paper, a simple label-free DNA sensor, which consisted of a poly(3-alkoxy-4-methylthiophene) and an aptamer, was used to detect L-argininamide (L-Arm). Due to the specific binding reaction between L-Arm and its aptamer, the proposed method can easily determinate the L-Arm through the recovery of fluorescence without any modification. Other ions or similar molecules had little effect on the detection. Moreover, there was a linear relationship between fluorescence intensity and the concentration of L-Arm. The detection limit of L-Arm was as low as 4.7 nM.

12.
Luminescence ; 25(4): 311-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19630090

RESUMO

Water-soluble fluorescent conjugated polymers can be used as an optical platform in highly sensitive DNA sensors. Here we report a simple label-free DNA sensor using poly(3-alkoxy-4-methylthiophene) to recognize and detect different oligonucleotide targets related to the YMDD gene mutation of hepatitis B virus. The concentration of surfactant Triton X-100, NaCl, the oligonucleotide capture probe and the oligonucleotide hybridization conditions have a great impact on fluorescence intensity. Under the optimum conditions, two types of oligonucleotide targets involving YMDD gene mutation of hepatitis B virus were successfully recognized. Moreover, there was a linear relationship between fluorescence intensity and the concentration of oligonucleotide target. The detection limit of the wild-type hepatitis B virus target is 88 pmol L(-1).


Assuntos
Sondas de DNA/química , DNA Viral/análise , Fluorescência , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Sondas de Oligonucleotídeos/química , Oligonucleotídeos/análise , Cátions/química , DNA Viral/genética , Mutação , Oligonucleotídeos/genética
13.
Nanotechnology ; 20(32): 325101, 2009 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-19620762

RESUMO

A layer-by-layer surface decoration technique has been developed to anchor quantum dots (QDs) onto a gold substrate and an in situ surface plasmon resonance technique has been used to study interactions between the QDs and different proteins. Direct observation of the binding of the protein onto the QDs and the kinetics of the adsorption and dissociation of different proteins on the QDs has been achieved. This would be helpful for the identification of particle-associated proteins and may offer a fundamental prerequisite for nanobiology, nanomedicine and nanotoxicology. The combination of the novel layer-by-layer surface modification method and in situ surface plasmon resonance would be powerful in studying biological systems such as DNA and cells.


Assuntos
Proteínas/metabolismo , Pontos Quânticos , Ressonância de Plasmônio de Superfície/métodos , Eletricidade , Ouro/metabolismo , Humanos , Ligação Proteica , Proteínas/química , Propriedades de Superfície
14.
Anal Chim Acta ; 645(1-2): 73-8, 2009 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-19481633

RESUMO

In this contribution, a simple and sensitive method for L-cysteine detection was established based on the increment of the fluorescence intensity of mercaptoacetic acid-capped CdSe/ZnS quantum dots (QDs) in aqueous solution. Meanwhile, the fluorescence characteristics and the optimal conditions were investigated in detail. Under the optimized conditions, the linear range of QDs fluorescence intensity versus the concentration of L-cysteine was 10-800 nmol L(-1), with a correlation coefficient (R) of 0.9969 and a limit of detection (3sigma black) of 3.8 nmol L(-1). The relative standard deviation (R.S.D.) for 0.5 micromol L(-1) L-cysteine was 1.1% (n = 5). There was no interference to coexisting foreign substances including common ions, carbohydrates, nucleotide acids and other 19 amino acids. The proposed method possessed the advantages of simplicity, rapidity and sensitivity. Synthetic amino acid samples, medicine sample together with human urine samples were analyzed by the methodology and the results were satisfying.


Assuntos
Cisteína/análise , Pontos Quânticos , Espectrometria de Fluorescência/métodos , Compostos de Cádmio/química , Calibragem , Cisteína/urina , Humanos , Concentração de Íons de Hidrogênio , Octoxinol/química , Concentração Osmolar , Compostos de Selênio/química , Sensibilidade e Especificidade , Espectrometria de Fluorescência/economia , Sulfetos/química , Tioglicolatos/química , Compostos de Zinco/química
15.
Talanta ; 79(2): 153-8, 2009 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-19559857

RESUMO

In this contribution, we designed a fluorescent thiophene copolymer to detect insertion/deletion mutation in DNA by doping aldehyde group in the main chain. The fluorescence of the copolymer could be dramatically quenched on the addition of single-stranded DNA (ssDNA) via strong electrostatic interactions and electronic/energy transfer. Although the complementary ssDNA made the fluorescence recover, the hydrogen bonds and chemical coupling also played a significant role between the unpaired bases and aldehyde group, which could differentiate the subtle differences in such mutant DNA. The influence of buffer pH, concentration of NaCl, heating time and the temperature was systemically investigated and the proposed method was then successfully applied to detect real sample. With the respect to the linearity, limit of detection precision, specificity, this procedure could provide sensitive methodologies for the rapid detection and identification of nucleic acids.


Assuntos
Análise Mutacional de DNA/métodos , Ácidos Nucleicos/análise , Polímeros , Deleção de Sequência , Tiofenos , Pareamento de Bases , Cátions , DNA/genética , Fluorescência , Solubilidade
16.
Talanta ; 77(1): 319-24, 2008 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-18804640

RESUMO

In recent years, gold nanoparticles and water-soluble fluorescent conjugated polymers are promising materials in terms of their potential applications in a variety of fields, ranging from monitoring DNA hybridization to demonstrate the interaction between proteins, or detecting diseased cell, metal ions and small biomolecular. In order to exploit some new properties of the both, many attempts have been devoted to achieve nanoparticle-polymer composite via incorporating metal nanoparticle into polymer or vice versa, however, only few of them are put into practical application. In the present paper, we utilize the "superquenching" property of AuNPs to polythiophene derivatives for detecting aspartic acid (Asp) and glutamic acid (Glu) in pure water, and discuss the factors accounting for fluorescence quenching and recovery via modulating pH. Thus an exceptionally simple, rapid and sensitive method for detecting Asp and Glu is established with a limit of detection (LOD) is 32 nM for Asp and 57 nM for Glu, the linear range of determination for Asp is 7.5x10(-8)M to 6x10(-6)M and 9.0x10(-8)M to 5x10(-6)M for Glu. The system is applied to real sample detection and the results are satisfying. Otherwise the composite is very sensitive to pH change of solution, we expect it will be possible to use as pH sensor with wide range in the future.


Assuntos
Ácido Aspártico/análise , Ácido Glutâmico/análise , Ouro/química , Nanopartículas Metálicas/química , Polímeros/química , Tiofenos/química , Ácido Aspártico/química , Ácido Glutâmico/química , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Estrutura Molecular , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Soluções , Espectrofotometria
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...