Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell Mol Biol (Noisy-le-grand) ; 70(2): 51-61, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38430038

RESUMO

Anoikis emerges when a cell finds itself extricated from the appropriate extracellular matrix, leading to an interruption in integrin ligation and thus triggering programmed cellular demise. The cardinal role of Anoikis in the realms of tumor invasion and metastasis is undeniable, although our grasp on its precise influence within the convoluted landscape of cancer biology remains somewhat circumscribed. Notably, both the immune milieu of the tumor and its inherent aggression are correlated with the fluctuating variables of Anoikis. We conducted a thorough evaluation of the genes associated with anoikis and studied the regulatory patterns of these genes as well as the prognostic impact of anoikis in 33 different types of tumors. We provided functional annotations for the regulatory patterns linked to Anoikis. Additionally, we described the associations between immunological factors and genes associated with Anoikis. By applying gene set variation analysis (GSVA), we utilized the inherent abilities of 34 basic genes to calculate the Anoikis index. The Anoikis index is closely related to prognosis, immune microenvironment, immunotherapy, and other aspects. Our functional research revealed a correlation between immune cell infiltration, EMT, and a regulatory gene that is synonymous with adverse survival outcomes. In addition, our observations revealed a direct relationship between the expression of CEACAM5 and CEACAM6,the amplification of epithelial mesenchymal transition (EMT) phenomenon, and a decrease in survival outcomes.The potential therapeutic utility of anoikis-related genes was highlighted by the possible links between TME, clinical samples, genetic mutations, drug resistance, and immunotherapy.


Assuntos
Anoikis , Neoplasias , Humanos , Anoikis/genética , Linhagem Celular Tumoral , Neoplasias/genética
2.
Opt Express ; 30(6): 8676-8689, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35299314

RESUMO

A Mueller matrix (MM) provides a comprehensive representation of the polarization properties of a complex medium and encodes very rich information on the macro- and microstructural features. Histopathological features can be characterized by polarization parameters derived from MM. However, a MM must be derived from at least four Stokes vectors corresponding to four different incident polarization states, which makes the qualities of MM very sensitive to small changes in the imaging system or the sample during the exposures, such as fluctuations in illumination light and co-registration of polarization component images. In this work, we use a deep learning approach to retrieve MM-based specific polarimetry basis parameters (PBPs) from a snapshot Stokes vector. This data post-processing method is capable of eliminating errors introduced by multi-exposure, as well as reducing the imaging time and hardware complexity. It shows the potential for accurate MM imaging on dynamic samples or in unstable environments. The translation model is designed based on generative adversarial network with customized loss functions. The effectiveness of the approach was demonstrated on liver and breast tissue slices and blood smears. Finally, we evaluated the performance by quantitative similarity assessment methods in both pixel and image levels.


Assuntos
Aprendizado Profundo , Mama , Fígado , Análise Espectral
3.
Sleep Breath ; 26(2): 689-696, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34302610

RESUMO

PURPOSE: Ultra-wideband bio-radar (UWB) is a new non-contact technology that can be used to screen for obstructive sleep apnea (OSA). However, little information is available regarding its reliability. This study aimed to evaluate the effectiveness of UWB and to determine if UWB could provide a novel and reliable method for the primary screening of sleep-related breathing disorders. METHOD: Subjects with suspected OSA from the sleep center of the First Hospital of the China Medical University were assessed over the period of September 2018 to April 2019 for enrollment in the study. Three detection methods were simultaneously used, including the STOP-Bang questionnaire (SBQ), UWB, and standard polysomnography (PSG). The data were analyzed using a fourfold table, receiver operating characteristic curves, Spearman rank correlation coefficients, Bland-Altman plots, and epoch-by-epoch analysis. RESULT: Of 67 patients, 56 were men, mean age was 43 ± 11 years, mean body mass index was 27.8 ± 4.8 kg/m2, and mean SBQ score was 4.8 ± 1.6. The apnea-hypopnea index (AHI) (r = 0.82, p < 0.01) and minimum arterial oxygen saturation (r = 0.80, p < 0.01) of the UWB were positively correlated with those obtained from the PSG. UWB performed better than SBQ, as indicated by the larger area under the curve (0.85 vs. 0.632). The sensitivity and specificity of the UWB-AHI were good (100%, 70%, respectively). CONCLUSIONS: UWB performs well in the screening of OSA and can provide reliable outcomes for the screening of OSA at the primary level.


Assuntos
Radar , Apneia Obstrutiva do Sono , Adulto , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Polissonografia , Reprodutibilidade dos Testes , Sono , Apneia Obstrutiva do Sono/diagnóstico , Inquéritos e Questionários
4.
Bull Environ Contam Toxicol ; 109(1): 186-193, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35381871

RESUMO

One-step separation and recovery of sodium, aluminum and iron in high-iron red mud in a high-calcium alkaline hydrothermal system is realized by a high-pressure hydrothermal reduction process. The transformation behavior of the aluminasilica phase in high-iron red mud is mainly investigated. The results show that under the optimized conditions, a temperature of 290℃, a Na2O concentration of 240 g/L, a calcium to silicon ratio of 3.5, and a liquid-solid ratio of 5, the Na2O content in the transition slag is reduced to 0.12%, the dealkalization rate can reach 98%, and the alumina dissolution rate is 73%. When the starch-free reductant is added, the transition slag mainly consists of hematite and hydroandradite, and when the starch reductant is added (the addition amount is 1/4 that of ω(Fe2O3) in the red mud), all Fe2O3 in the transition slag is completely reduced to Fe3O4, and the main phases are magnetite and hydrogrossular.

5.
BMC Plant Biol ; 21(1): 478, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34670494

RESUMO

BACKGROUND: Catechins are crucial in determining the flavour and health benefits of tea, but it remains unclear that how the light intensity regulates catechins biosynthesis. Therefore, we cultivated tea plants in a phytotron to elucidate the response mechanism of catechins biosynthesis to light intensity changes. RESULTS: In the 250 µmol·m- 2·s- 1 treatment, the contents of epigallocatechin, epigallocatechin gallate and total catechins were increased by 98.94, 14.5 and 13.0% respectively, compared with those in the 550 µmol·m- 2·s- 1 treatment. Meanwhile, the photosynthetic capacity was enhanced in the 250 µmol·m- 2·s- 1 treatment, including the electron transport rate, net photosynthetic rate, transpiration rate and expression of related genes (such as CspsbA, CspsbB, CspsbC, CspsbD, CsPsbR and CsGLK1). In contrast, the extremely low or high light intensity decreased the catechins accumulation and photosynthetic capacity of the tea plants. The comprehensive analysis revealed that the response of catechins biosynthesis to the light intensity was mediated by the photosynthetic capacity of the tea plants. Appropriately high light upregulated the expression of genes related to photosynthetic capacity to improve the net photosynthetic rate (Pn), transpiration rate (Tr), and electron transfer rate (ETR), which enhanced the contents of substrates for non-esterified catechins biosynthesis (such as EGC). Meanwhile, these photosynthetic capacity-related genes and gallic acid (GA) biosynthesis-related genes (CsaroB, CsaroDE1, CsaroDE2 and CsaroDE3) co-regulated the response of GA accumulation to light intensity. Eventually, the epigallocatechin gallate content was enhanced by the increased contents of its precursors (EGC and GA) and the upregulation of the CsSCPL gene. CONCLUSIONS: In this study, the catechin content and photosynthetic capacity of tea plants increased under appropriately high light intensities (250 µmol·m- 2·s- 1 and 350 µmol·m- 2·s- 1) but decreased under extremely low or high light intensities (150 µmol·m- 2·s- 1 or 550 µmol·m- 2·s- 1). We found that the control of catechin accumulation by light intensity in tea plants is mediated by the plant photosynthetic capacity. The research provided useful information for improving catechins content and its light-intensity regulation mechanism in tea plant.


Assuntos
Camellia sinensis/efeitos da radiação , Catequina/análogos & derivados , Catequina/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Fotossíntese/efeitos da radiação , Proteínas de Plantas/metabolismo , Camellia sinensis/genética , Camellia sinensis/fisiologia , Catequina/efeitos da radiação , Luz , Proteínas de Plantas/genética , Plântula/genética , Plântula/fisiologia , Plântula/efeitos da radiação , Regulação para Cima
6.
Opt Lett ; 46(7): 1676-1679, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33793516

RESUMO

In this Letter, we report a dual division of focal plane (DoFP) polarimeters-based full Mueller matrix microscope (DoFPs-MMM) for fast polarization imaging. Both acquisition speed and measurement accuracy are improved compared with those of a Mueller matrix microscope based on dual rotating retarders. Then, the system is applied to probe the polarization properties of a red blood cells smear. The experimental results show that a DoFPs-MMM has the potential to be a powerful tool for probing dynamic processes in living cells in future studies.


Assuntos
Microscopia/instrumentação , Algoritmos , Desenho de Equipamento , Microscopia de Polarização
7.
Appl Opt ; 60(5): 1380-1386, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33690582

RESUMO

Mueller matrix (MM) imaging has demonstrated its potential application in much research, especially in probing delicate and complex biomedical specimens. Qualities of MM images are important for further quantitative characterization. In this paper, we compare the performance and imaging qualities of three calibration methods. Air, waveplate and cell specimen are selected as standard samples for comparison. In addition, we also propose two general MM imaging quality indices that can be used as quantitative evaluations for MM imaging systems and calculation processes based on real samples. The numerical calibration method turns out to give the best accuracy and precision, as well as the best image qualities.


Assuntos
Microscopia de Polarização/métodos , Imagem Óptica/métodos , Ar , Calibragem/normas , Células HeLa , Humanos , Luz , Microscopia de Polarização/normas , Imagem Óptica/normas
8.
Sleep Breath ; 25(1): 289-297, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32529520

RESUMO

PURPOSE: Daytime sleepiness is a common symptom of obstructive sleep apnea (OSA) and is more common in men, but the underlying mechanism remains unclear. The aim of this study was to assess whether or not sex differences in daytime sleepiness persisted after controlling for age and OSA severity and to explore the factors contributing to daytime sleepiness in patients with OSA. METHODS: A total of 104 pairs of patients with OSA, matched by age and apnea-hypopnea index (AHI), were enrolled in this retrospective study. Demographic data were collected; daytime sleepiness was measured by the Epworth Sleepiness Scale (ESS); and polysomnography (PSG) was performed on each participant. These measurements were compared between sexes, and the factors affecting daytime sleepiness were explored with correlation and multivariate linear regression analyses. RESULTS: Men had significantly higher ESS scores (p = 0.021) than women. Regarding demographics, BMI, neck/height ratio, and proportion of habitual smoking and alcohol intake were significantly higher in men. Regarding PSG findings, men had more rapid eye movement sleep, a longer mean apnea-hypopnea duration, and a longer mean apnea duration (MAD). Regression analysis showed that two sex-associated variables, habitual smoking (ß = 0.189, p = 0.006) and MAD (ß = 0.154, p = 0.024), had the strongest association with ESS scores. Further analysis revealed that MAD was significantly influenced by apnea index (ß = 0.306, p < 0.001) and sex (ß = - 0.193, p = 0.003). CONCLUSION: The sex difference in daytime sleepiness persists in patients with OSA, even after matching AHI and age. The difference is mediated by sex-specific smoking habits and sex differences in apnea duration.


Assuntos
Fumar Cigarros/epidemiologia , Distúrbios do Sono por Sonolência Excessiva/epidemiologia , Apneia Obstrutiva do Sono/epidemiologia , Adulto , Distúrbios do Sono por Sonolência Excessiva/etiologia , Distúrbios do Sono por Sonolência Excessiva/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Índice de Gravidade de Doença , Caracteres Sexuais , Fatores Sexuais , Apneia Obstrutiva do Sono/complicações , Apneia Obstrutiva do Sono/fisiopatologia , Sono REM/fisiologia , Fatores de Tempo
9.
Sleep Breath ; 25(3): 1419-1426, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33236203

RESUMO

PURPOSE: The relationship between obstructive sleep apnea (OSA) and pulmonary embolism (PE) has been reported by some studies but the underlying mechanism remains unclear. We aimed to systematically assess the role of OSA on the disease prognosis of PE. METHODS: We searched for studies on the relationship of OSA and the prognosis of PE published up to February 2020 among PubMed, Web of Science, EMBASE, and Cochrane Library databases. Two independent reviewers conducted the process of study search and screening, quality assessment, and data extraction. Meta-analysis was carried out using RevMan 5.3. RESULTS: A total of 9 articles were included, and the funnel plots suggested no evidence of publication bias among studies. The results showed that compared to PE patients without OSA, the PE patients with moderate-severe OSA were more likely to be high-risk type (OR = 1.96, 95% CI [1.14, 3.34]) and with higher index of disease severity (sPESI: OR = 2.29, 95% CI [1.50, 3.47]; PAOI%: MD = 13.52, 95% CI [7.2, 19.83]). The prevalence of recurrent PE was higher in PE patients with OSA than those without OSA (RR = 3.87, 95% CI [1.65, 9.07]). However, there was no significant difference in right ventricle to left ventricle short-axis diameter (MD = 0.08, 95% CI [- 0.06, 0.21]), length of hospital stay (MD = 1.03, 95% CI [- 1.11, 3.17]), or prevalence of deep vein thrombosis (OR = 0.87, 95% CI [0.48, 1.57]). Sensitivity and subgroup analysis showed that the pooled outcomes were stable. CONCLUSION: OSA, especially moderate-severe OSA, was a risk factor for high-risk PE and recurrent PE. However, the current evidence showed that the length of hospital stay is not influenced by OSA.


Assuntos
Embolia Pulmonar/terapia , Apneia Obstrutiva do Sono/epidemiologia , Humanos , Prevalência , Prognóstico , Embolia Pulmonar/epidemiologia , Recidiva , Fatores de Risco , Índice de Gravidade de Doença
10.
FASEB J ; 33(6): 6697-6712, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30848934

RESUMO

Emerging evidence indicates that Ca2+ is a vital factor in modulating the pathogenesis of Alzheimer's disease (AD). In healthy neurons, Ca2+ concentration is balanced to maintain a lower level in the cytosol than in the extracellular space or certain intracellular compartments such as endoplasmic reticulum (ER) and the lysosome, whereas this homeostasis is broken in AD. On the plasma membrane, the AD hallmarks amyloid-ß (Aß) and tau interact with ligand-gated or voltage-gated Ca2+-influx channels and inhibit the Ca2+-efflux ATPase or exchangers, leading to an elevated intracellular Ca2+ level and disrupted Ca2+ signal. In the ER, the disabled presenilin "Ca2+ leak" function and the direct implications of Aß and presenilin mutants contribute to Ca2+-signal disorder. The enhanced ryanodine receptor (RyR)-mediated and inositol 1,4,5-trisphosphate receptor (IP3R)-mediated Ca2+ release from the ER aggravates cytosolic Ca2+ disorder and triggers apoptosis; the down-regulated ER Ca2+ sensor, stromal interaction molecule (STIM), alleviates store-operated Ca2+ entry in plasma membrane, leading to spine loss. The increased transfer of Ca2+ from ER to mitochondria through mitochondria-associated ER membrane (MAM) causes Ca2+ overload in the mitochondrial matrix and consequently opens the cellular damage-related channel, mitochondrial permeability transition pore (mPTP). In this review, we discuss the effects of Aß, tau and presenilin on neuronal Ca2+ signal, focusing on the receptors and regulators in plasma membrane and ER; we briefly introduce the involvement of MAM-mediated Ca2+ transfer and mPTP opening in AD pathogenesis.-Wang, X., Zheng, W. Ca2+ homeostasis dysregulation in Alzheimer's disease: a focus on plasma membrane and cell organelles.


Assuntos
Doença de Alzheimer/patologia , Cálcio/metabolismo , Membrana Celular/metabolismo , Homeostase , Organelas/metabolismo , Doença de Alzheimer/metabolismo , Animais , Sinalização do Cálcio , Humanos
11.
Sensors (Basel) ; 20(20)2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-33096726

RESUMO

An inductive debris sensor can monitor a mechanical system's debris in real time. The measuring accuracy is significantly affected by the signal aliasing issue happening in the monitoring process. In this study, a mathematical model was built to explain two debris particles' aliasing behavior. Then, a cross-correlation-based method was proposed to deal with this aliasing. Afterwards, taking advantage of the processed signal along with the original signal, an optimization strategy was proposed to make the evaluation of the aliasing debris more accurate than that merely using initial signals. Compared to other methods, the proposed method has fewer limitations in practical applications. The simulation and experimental results also verified the advantage of the proposed method.

12.
Sensors (Basel) ; 17(11)2017 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-29068392

RESUMO

Moving towards the more electric aircraft (MEA), a hybrid actuator configuration provides an opportunity to introduce electromechanical actuator (EMA) into primary flight control. In the hybrid actuation system (HAS), an electro-hydraulic servo actuator (EHSA) and an EMA operate on the same control surface. In order to solve force fighting problem in HAS, this paper proposes a novel linear extended state observer (LESO)-based motion synchronization control method. To cope with the problem of unavailability of the state signals required by the motion synchronization controller, LESO is designed for EHSA and EMA to observe the state variables. Based on the observed states of LESO, motion synchronization controllers could enable EHSA and EMA to simultaneously track the desired motion trajectories. Additionally, nonlinearities, uncertainties and unknown disturbances as well as the coupling term between EHSA and EMA can be estimated and compensated by using the extended state of the proposed LESO. Finally, comparative simulation results indicate that the proposed LESO-based motion synchronization controller could reduce significant force fighting between EHSA and EMA.

13.
Zhongguo Dang Dai Er Ke Za Zhi ; 18(8): 721-5, 2016 Aug.
Artigo em Zh | MEDLINE | ID: mdl-27530789

RESUMO

OBJECTIVE: To investigate the changes in the expression levels of peripheral blood T helper 9 (Th9) cells and cytokine interleukin-9 (IL-9) in children in the acute stage of Kawasaki disease (KD) and their clinical significance. METHODS: A total of 45 children in the acute stage of KD who were treated from April 2014 to July 2015 were enrolled, and the children were followed up in the recovery stage. Another 45 healthy children who underwent physical examination were enrolled as the control group. Flow cytometry was used to measure the percentage of peripheral blood Th9 cells, and ELISA was used to measure the serum level of IL-9. RESULTS: The children in the acute stage of KD showed a significantly higher percentage of Th9 cells and a significantly higher serum level of IL-9 compared with those in the recovery stage and the control group (P<0.05). The percentage of Th9 cells and serum level of IL-9 showed no significant differences between the children in the recovery stage and those in the control group (P>0.05). In the acute stage, the percentage of Th9 cells was positively correlated with the levels of IL-9, C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate (ESR), platelet count (PLT), and globulin (r=0.624, 0.324, 0.402, 0.382, 0.467, and 0.386 respectively, all P<0.05), but negatively correlated with serum albumin (r=-0.306, P<0.05). The serum level of IL-9 was positively correlated with the levels of CRP, PCT, ESR, PLT, and globulin (r=0.365, 0.456, 0.403, 0.423, and 0.453 respectively, all P<0.05), but negatively correlated with serum albumin (r=-0.343, P<0.05). CONCLUSIONS: The children in the acute stage of KD show significant increases in the percentage of peripheral Th9 cells and serum cytokine IL-9 level, which return to normal in the recovery stage. In the acute stage of KD, the expression levels of Th9 and IL-9 are closely correlated with laboratory markers. The results suggest that Th9 cells and IL-9 play important roles in the pathogenesis and outcome of KD.


Assuntos
Interleucina-9/sangue , Síndrome de Linfonodos Mucocutâneos/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Doença Aguda , Sedimentação Sanguínea , Proteína C-Reativa/análise , Pré-Escolar , Feminino , Humanos , Lactente , Masculino
14.
PLoS One ; 19(5): e0302492, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38713661

RESUMO

The Perona-Malik (P-M) model exhibits deficiencies such as noise amplification, new noise introduction, and significant gradient effects when processing noisy images. To address these issues, this paper proposes an image-denoising algorithm, ACE-GPM, which integrates an Automatic Color Equalization (ACE) algorithm with a gradient-adjusted P-M model. Initially, the ACE algorithm is employed to enhance the contrast of low-light images obscured by fog and noise. Subsequently, the Otsu method, a technique to find the optimal threshold based on between-class variance, is applied for precise segmentation, enabling more accurate identification of different regions within the image. After that, distinct gradients enhance the image's foreground and background via an enhancement function that accentuates edge and detailed information. The denoising process is finalized by applying the gradient P-M model, employing a gradient descent approach to further emphasize image edges and details. Experimental evidence indicates that the proposed ACE-GPM algorithm not only elevates image contrast and eliminates noise more effectively than other denoising methods but also preserves image details and texture information, evidenced by an average increase of 0.42 in the information entropy value. Moreover, the proposed solution achieves these outcomes with reduced computational resource expenditures while maintaining high image quality.


Assuntos
Algoritmos , Processamento de Imagem Assistida por Computador , Razão Sinal-Ruído , Processamento de Imagem Assistida por Computador/métodos , Iluminação/métodos , Humanos , Cor , Aumento da Imagem/métodos
15.
IEEE Trans Cybern ; 54(1): 87-100, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37022446

RESUMO

Hierarchical frameworks-a special class of directed frameworks with a layer-by-layer architecture-can be an effective mechanism to coordinate robot swarms. Their effectiveness was recently demonstrated by the mergeable nervous systems paradigm (Mathews et al., 2017), in which a robot swarm can switch dynamically between distributed and centralized control depending on the task, using self-organized hierarchical frameworks. New theoretical foundations are required to use this paradigm for formation control of large swarms. In particular, the systematic and mathematically analyzable organization and reorganization of hierarchical frameworks in a robot swarm is still an open problem. Although methods for framework construction and formation maintenance via rigidity theory exist in the literature, they do not address cases of hierarchy in a robot swarm. In this article, we extend bearing rigidity to directed topologies and extend the Henneberg constructions to generate self-organized hierarchical frameworks with bearing rigidity. We investigate three-key self-reconfiguration problems: 1) framework merging; 2) robot departure; and 3) framework splitting. We also derive the mathematical conditions of these problems and then develop algorithms that preserve rigidity and hierarchy using only local information. Our approach can be used for formation control generally, as in principle it can be coupled with any control law that makes use of bearing rigidity. To demonstrate and validate our proposed hierarchical frameworks and methods, we apply them to four scenarios of reactive formation control using an example control law.

16.
Am J Trop Med Hyg ; 111(3): 490-497, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-38981503

RESUMO

Malaria continues to be a major source of morbidity and mortality in sub-Saharan Africa. Timely, accurate, and effective case management is critical to malaria control. Proactive community case management (ProCCM) is a new strategy in which a community health worker "sweeps" a village, visiting households at defined intervals to proactively provide diagnostic testing and treatment if indicated. Pilot experiments have shown the potential of ProCCM for controlling malaria transmission; identifying the best strategy for administering ProCCM in terms of interval timings and number of sweeps could lead to further reductions in malaria infections. We developed an agent-based simulation to model malaria transmission and the impact of various ProCCM strategies. The model was validated using symptomatic prevalence data from a ProCCM pilot study in Senegal. Various ProCCM strategies were tested to evaluate the potential for reducing parasitologically confirmed symptomatic malaria cases in the Senegal setting. We found that weekly ProCCM sweeps during a 21-week transmission season could reduce cases by 36.3% per year compared with no sweeps. Alternatively, two initial fortnightly sweeps, seven weekly sweeps, and finally four fortnightly sweeps (13 sweeps total) could reduce confirmed malaria cases by 30.5% per year while reducing the number of diagnostic tests and corresponding costs by about 33%. Under a highly seasonal transmission setting, starting the sweeps early with longer duration and higher frequency would increase the impact of ProCCM, though with diminishing returns. The model is flexible and allows decision-makers to evaluate implementation strategies incorporating sweep frequency, time of year, and available budget.


Assuntos
Administração de Caso , Malária , Humanos , Malária/prevenção & controle , Malária/epidemiologia , Malária/transmissão , Malária/diagnóstico , Malária/tratamento farmacológico , África Subsaariana/epidemiologia , Senegal/epidemiologia , Criança , Pré-Escolar , Prevalência , Agentes Comunitários de Saúde , Adolescente , Adulto , Lactente , Projetos Piloto , Serviços de Saúde Comunitária , Feminino , Masculino , Modelos Teóricos
17.
Zootaxa ; 3710: 333-53, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26106695

RESUMO

Eight new species of Trypetinae (Diptera: Tephritidae) from China are described and illustrated. The new species are Cornutrypeta chishuiensis Chen sp. nov., C. motuonia Chen sp. nov., Hoplandromyia hubeiensis Chen sp. nov., H. motuonica Chen sp. nov., Magnimyiolia disrupta Chen sp. nov., M tengchongnica Chen sp. nov., M tibetana Chen et Wang sp. nov. and M. yunnanica Chen et Wang sp. nov. Keys to the known species of the genera Cornutrypeta Han et Wang and Hoplandromyia Bezzi from the World, and the genera Magnimyiolia Shiraki from East Asia are updated and provided. C. spinifrons (Schroeder) is newly recorded from China, and the female of C. hunanica Chen et Wang is recorded, described and illustrated for the first time. Illustrations of the type of M huanana Wang and a new distribution of C. hunanica Chen et Wang are provided.


Assuntos
Biodiversidade , Tephritidae/classificação , Animais , China , Feminino , Masculino , Tephritidae/anatomia & histologia
18.
ISA Trans ; 137: 248-262, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36577622

RESUMO

The dual-motor driving servo system is continuously developed to satisfy strict safety and reliability requirements. However, several factors may degrade the system's performance, such as transmission backlash, parameter drift, and motor dynamic characteristic differences. To overcome these factors, this study proposes a finite-time tracking and synchronization control method for dual-motor servo systems that suffer from backlash and time-varying uncertainties. Our solution utilizes an adaptive dynamic surface and cross-coupling control scheme to deal with tracking and synchronization control issues and compensate for the unknown time-varying uncertainties. Through synchronizing the speed and acceleration states, the proposed controller guarantees high control performance and eliminates the force fighting caused by the motor's dynamic characteristic differences. In addition, finite-time control ensures the tracking error converges to an arbitrarily small neighborhood of zero in finite time. Moreover, the singularity problem in the derivative of the virtual control signal is avoided by introducing a new compensation term. Several simulations prove the proposed controller's stability and effectiveness.

19.
ISA Trans ; 136: 345-360, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36509578

RESUMO

This paper addresses formation control of underactuated autonomous underwater vehicles in three-dimensional space, using a hybrid protocol that combines aspects of centralized and decentralized control with constraints that are particular to underwater vehicles, including switching topologies, unmeasurable velocities, and system constraints. Using a distributed leader-follower model, the hybrid formation protocol does not require velocity sensing, access to global information, or static and connected topologies. To handle switching jointly connected networks-that is, to tolerate temporary disconnections-a distributed observer is designed for followers to cooperatively estimate leader states using local measurements and local interactions. On this basis, a compound formation control strategy is proposed to achieve geometric convergence. Firstly, cascaded extended state observers are developed to recover the unmeasurable velocities and unknown dynamic uncertainties induced by internal model uncertainty and external disturbances. Secondly, an improved three-dimensional line-of-sight guidance law at the kinematic level is used to address the underactuated configuration and the nonzero attack and sideslip angles. Thirdly, to overcome potential instability as a result of system constraints, including velocity constraints and input saturations, two adaptive compensators in the dynamic controller are used to address the negative effects of truncation. Using the proposed approach, the estimation errors and formation tracking errors are proved to be uniformly and ultimately bounded. Additionally, the numerical simulation results verify the performance of the approach and demonstrate improvement over both distributed and centralized state-of-the-art approaches.

20.
ACS Appl Mater Interfaces ; 15(23): 28175-28183, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37276488

RESUMO

Photodetectors (PDs) are critical parts of visible light communication (VLC) systems for achieving efficient photoelectronic conversion and high-fidelity transmission of signals. Antimony sulfide (Sb2S3) as a nontoxic, high optical absorption coefficient, and low-cost semiconductor becomes a promising candidate for applications in VLC systems. Particularly, Sb2S3 PDs were verified to have significantly weak light detection ability in the visible region. However, the response speed of Sb2S3 PDs with existing device structures is still relatively slow. Herein, through optimizing the device structure for the p-i-n type PDs, a p-type Sb2Se3 hole transport layer (HTL) is designed to enhance the built-in electric field and to accelerate the migration of photogenerated carriers for the high responsivity and fast response speed. The optimal thickness of the structure is obtained through the simulation of SCAPS-1D software, and the optimized devices show high-performance parameters, including a responsivity of 0.34 A W-1, a specific detectivity (D*) of 2.20 × 1012 Jones, the -3 dB bandwidth of 440 kHz, high stability, and the value of the Sb2S3 PDs can reach 60% in the range of 360-600 nm, which indicates that the device is very suitable for working in the visible light band. In addition, the resulting Sb2S3 PD is successfully integrated into VLC systems by designing a matched light detection circuit. The results suggest that the Sb2S3 PDs are expected to provide an alternative to future VLC system applications.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA