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1.
Opt Express ; 32(2): 1465-1477, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297697

RESUMO

High power and high brightness laser lighting puts forward new requirements for phosphor converters such as high luminous efficiency, high thermal conductivity and high saturation threshold due to the severe thermal effect. The structure design of phosphor converters is proposed as what we believe to be a novel strategy for less heat production and more heat conduction. In this work, the rod-shaped YAG:Ce phosphor ceramics (PCs) and disc-shaped YAG:Ce PCs as control group were fabricated by the gel casting and vacuum sintering, to comparatively study the luminescence performance for LD lighting, on the premise that the total number of transverse Ce3+ ions and the volume of samples from two comparison groups were same. All rod YAG:Ce PCs with low Ce3+ concentration exhibited the high luminous efficiency and better thermal stability than YAG:Ce discs with high Ce3+ concentration. Under the laser power density of 47.8 W/mm2, the luminous saturation was never observed in all rod-shaped YAG:Ce PCs. The high luminous efficacy of 245∼274 lm/W, CRI of 56.3∼59.5 and CCT of 4509∼4478 K were achieved. More importantly, due to the extremely low Ce3+ doping concentration (0.01 at%), rod-shaped ceramics based LDs devices showed the excellent thermal performance and their surface temperatures were even below 30.5 °C surprisingly under the laser power density of 20.3 W·mm-2 (2 W). These results indicate that the rod shape of phosphor converter is a promising structure engineering for high power laser lighting.

2.
BMC Infect Dis ; 23(1): 896, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-38124031

RESUMO

BACKGROUND: Currently, some meta-analyses on COVID-19 have suggested that glucocorticoids use can reduce the mortality rate of COVID-19 patients, utilization rate of invasive ventilation, and improve the prognosis of patients. However, optimal regimen and dosages of glucocorticoid remain unclear. Therefore, the purpose of this network meta-analysis is to analyze the efficacy and safety of glucocorticoids in treating COVID-19 at regimens. METHODS: This meta-analysis retrieved randomized controlled trials from the earliest records to December 30, 2022, published in PubMed, Embase, Cochrane Library, CNKI Database and Wanfang Database, which compared glucocorticoids with placebos for their efficacy and safety in the treatment of COVID-19, Effects of different treatment regimens, types and dosages (high-dose methylprednisolone, very high-dose methylprednisolone, Pulse therapy methylprednisolone, medium-dose hydrocortisone, high-dose hydrocortisone, high-dose dexamethasone, very high-dose dexamethasone and placebo) on 28-day all-caused hospitalization mortality, hospitalization duration, mechanical ventilation requirement, ICU admission and safety outcome were compared. RESULTS: In this network meta-analysis, a total of 10,544 patients from 19 randomized controlled trials were finally included, involving a total of 9 glucocorticoid treatment regimens of different types and dosages. According to the analysis results, the 28-day all-cause mortality rate was the lowest in the treatment with pulse therapy methylprednisolone (OR 0.08, 95% CI 0.02, 0.42), but the use of high-dose methylprednisolone (OR 0.85, 95% CI 0.59, 1.22), very high-dose dexamethasone (OR 0.95, 95% CI 0.67, 1.35), high-dose hydrocortisone (OR 0.64, 95% CI 0.34, 1.22), medium-dose hydrocortisone (OR 0.80, 95% CI 0.49, 1.31) showed no benefit in prolonging the 28-day survival of patient. Compared with placebo, the treatment with very high-dose methylprednisolone (MD = -3.09;95%CI: -4.10, -2.08) had the shortest length of hospital stay, while high-dose dexamethasone (MD = -1.55;95%CI: -3.13,0.03) and very high-dose dexamethasone (MD = -1.06;95%CI: -2.78,0.67) did not benefit patients in terms of length of stay. CONCLUSIONS: Considering the available evidence, this network meta­analysis suggests that the prognostic impact of glucocorticoids in patients with COVID-19 may depend on the regimens of glucocorticoids. It is suggested that pulse therapy methylprednisolone is associated with lower 28-day all-cause mortality, very high-dose methylprednisolone had the shortest length of hospital stay in patients with COVID-19. TRIAL REGISTRATION: PROSPERO CRD42022350407 (22/08/2022).


Assuntos
COVID-19 , Glucocorticoides , Humanos , Glucocorticoides/efeitos adversos , Hidrocortisona/uso terapêutico , Metanálise em Rede , Metilprednisolona/efeitos adversos , Dexametasona/uso terapêutico
3.
Nature ; 503(7477): 509-12, 2013 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-24213630

RESUMO

Ferroelectrics have recently attracted attention as a candidate class of materials for use in photovoltaic devices, and for the coupling of light absorption with other functional properties. In these materials, the strong inversion symmetry breaking that is due to spontaneous electric polarization promotes the desirable separation of photo-excited carriers and allows voltages higher than the bandgap, which may enable efficiencies beyond the maximum possible in a conventional p-n junction solar cell. Ferroelectric oxides are also stable in a wide range of mechanical, chemical and thermal conditions and can be fabricated using low-cost methods such as sol-gel thin-film deposition and sputtering. Recent work has shown how a decrease in ferroelectric layer thickness and judicious engineering of domain structures and ferroelectric-electrode interfaces can greatly increase the current harvested from ferroelectric absorber materials, increasing the power conversion efficiency from about 10(-4) to about 0.5 per cent. Further improvements in photovoltaic efficiency have been inhibited by the wide bandgaps (2.7-4 electronvolts) of ferroelectric oxides, which allow the use of only 8-20 per cent of the solar spectrum. Here we describe a family of single-phase solid oxide solutions made from low-cost and non-toxic elements using conventional solid-state methods: [KNbO3]1 - x[BaNi1/2Nb1/2O3 - δ]x (KBNNO). These oxides exhibit both ferroelectricity and a wide variation of direct bandgaps in the range 1.1-3.8 electronvolts. In particular, the x = 0.1 composition is polar at room temperature, has a direct bandgap of 1.39 electronvolts and has a photocurrent density approximately 50 times larger than that of the classic ferroelectric (Pb,La)(Zr,Ti)O3 material. The ability of KBNNO to absorb three to six times more solar energy than the current ferroelectric materials suggests a route to viable ferroelectric semiconductor-based cells for solar energy conversion and other applications.

4.
Nanomedicine ; 22: 102100, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31648038

RESUMO

Development of a sensitive, rapid and easy-to-use liquid biopsy method is of imperative clinical value for point-of-care caner diagnostics. Here, a label-free and modification-free nanotechnology based on surface-enhanced Raman spectroscopy (SERS) was employed for DNA analysis. Using the SERS signals of phosphate backbone as internal standard, quantitative detection for nucleobases was achieved even at single base level. The method combined with principal component analysis and linear discriminant analysis was further applied for real blood circulating DNA detection for the first time, and an ideal diagnostic sensitivity of 83.3% and specificity of 82.5% could be obtained for differentiating the nasopharyngeal cancer from the normal group, demonstrating promising potential as an alternative nanotechnology for nasopharyngeal cancer screening based on liquid biopsy.


Assuntos
Ácidos Nucleicos Livres/sangue , Detecção Precoce de Câncer , Nanotecnologia , Neoplasias Nasofaríngeas/sangue , Neoplasias Nasofaríngeas/patologia , Análise Espectral Raman , Coloração e Rotulagem , Análise Discriminante , Humanos , Biópsia Líquida , Análise de Componente Principal
5.
Biochem Biophys Res Commun ; 500(3): 790-796, 2018 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-29684352

RESUMO

The transcription factor nuclear factor E2-related factor 2 (Nrf2) is known to control the expression of antioxidant response elements and cytoprotective genes and modulate inflammatory response, helping to ameliorate damage in many diseases. Exactly how Nrf2 regulates innate inflammatory homeostasis remains unclear. In this study, we provide in vitro and in vivo evidence that Nrf2 plays a crucial role in macrophage polarization and acute respiratory distress syndrome (ARDS). We conducted in vitro experiments using a mouse alveolar macrophage cell line as well as primary cultures of macrophages in which cells were exposed to lipopolysaccharide (LPS) or interferon-γ in order to mimic ARDS, in the presence or absence of the Nrf2 activator tert-butylhydroquinone (tBHQ). Using siRNA-mediated Nrf2 knockdown, we showed that Nrf2 inhibited the inflammatory response by promoting M2 macrophage polarization and inhibiting M1 macrophage polarization. At the same time, tBHQ activated Nrf2-mediated inhibition of the p65 nuclear factor-κB pathway and activation of peroxisome proliferator-activated receptor-γ, which play important roles in regulating macrophage polarization. We also conducted in vivo experiments in which mice were given tBHQ with or without intratracheal LPS, then their survival was monitored, lung injury was assessed using histology, and levels of pro- and anti-inflammatory cytokines were assayed in the lungs and serum. Activation of Nrf2 with tBHQ dramatically reduced LPS-induced mortality and lung injury, down-regulated pro-inflammatory mediators and up-regulated anti-inflammatory mediators. These results suggest that Nrf2 can help prevent ARDS progression by promoting M2 polarization of macrophages. Interfering with Nrf2 may be an effective strategy for reprogramming macrophage polarization in order to treat ARDS.


Assuntos
Polaridade Celular , Macrófagos/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Síndrome do Desconforto Respiratório/patologia , Síndrome do Desconforto Respiratório/prevenção & controle , Traqueia/metabolismo , Animais , Linhagem Celular , Polaridade Celular/efeitos dos fármacos , Citocinas/metabolismo , Hidroquinonas/farmacologia , Hidroquinonas/uso terapêutico , Mediadores da Inflamação/metabolismo , Lipopolissacarídeos , Lesão Pulmonar/tratamento farmacológico , Lesão Pulmonar/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Síndrome do Desconforto Respiratório/induzido quimicamente , Síndrome do Desconforto Respiratório/metabolismo
6.
Langmuir ; 34(37): 10955-10963, 2018 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-30130404

RESUMO

Liquid crystal (LC) ordering and phase transition behavior under confined conditions have attracted extensive attention and enabled many applications. However, the ordering and phase transition behavior of LCs in submicrometer capsules have seldom been studied, primarily due to the lack of proper capsulizing and visualization approaches to such small LC microcapsules. Herein, we achieve submicrometer LC capsules with the sizes down to 100 nm by using emulsion-based interfacial sol-gel reaction. The behavior of LCs under the submicrometer confinement conditions is investigated while the sizes and chemical composition of the microcapsule shell surface are tuned in a controllable way. The phase transition temperatures of LCs in the submicrometer capsules shift from those of bulk LCs due to the surface-induced ordering of LCs under the strong confinement conditions, which causes formation of topological defects and alters the order parameter. Using nonlinear optical imaging technology, we explore the structures of director field of LCs that arise as a result of the competition between the surface boundary conditions and LC elasticity. The results show that the nanoscale encapsulation can significantly influence the structural configurations of the director and phase transitions of LCs under various confinement conditions.

7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 48(3): 373-377, 2017 May.
Artigo em Chinês | MEDLINE | ID: mdl-28616909

RESUMO

OBJECTIVES: To investigate the expression of migration-inducing gene 7 (MIG7) in different HCC lines and its relationship with vasculogenic mimicry (VM) formation and metastatic potentiality. METHODS: Employing immunostaining to detect MIG7 protein expression and VM formation in 40 matched pairs of primary and metastatic HCC specimens from 40 patients, and investigating the correlation of VM formation with MIG7 protein expression. Detecting VM formation in HCC lines with different metastatic ability (MHCC-97H, MHCC-97L, Huh-7) and human normal hepatocyte line (L-02) through three-dimensional culture, and detecting MIG7 mRNA expression with RT-PCR, investigating the correlation of MIG7 protein expression with VM formation and HCC metastatic potentiality with Western blot assay; screening the HCC cell line with high MIG7 expression. RESULTS: In 40 matched pairs of HCC tissue, there was a significant positive correlation between MIG7 protein expression and VM formation ( rs=0.595, P<0.01). The capability of VM formation of MHCC-97H with high metastatic potentiality was stronger than that of MHCC-97L with low metastatic potentiality and Huh-7 with non-metastatic potentiality, and there was no VM formation in L-02. The result of RT-PCR and Western blot assay indicated the same. CONCLUSIONS: MIG7 expression in HCC tissue is high and correlated positively with VM formation. MIG7 expression in different HCC cell lines is coincident with theirs VM formation, invasion and metastasis. MIG7 is a potential target for inhibiting the invasion and metastasis of HCC.


Assuntos
Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/metabolismo , Metástase Neoplásica
8.
Opt Express ; 24(3): 2222-34, 2016 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-26906798

RESUMO

The purpose of this study was to develop a more powerful blood analysis method based on polarized surface enhanced Raman spectroscopy (SERS) technology for non-invasive and sensitive colorectal cancer (CRC) detection. The efficiency of different polarized scattering signals (non-polarization, parallel polarization and perpendicular polarization) on blood serum SERS was explored for the first time. Results demonstrated that polarized SERS was more sensitive to explore distinctive spectral differences between cancer and normal groups. And higher diagnostic accuracy of 91.6% could be achieved using polarized SERS integrated with PCA-LDA for classification of the two serum groups in comparison to conventional SERS technology. This exploratory study demonstrated that the nanobiosensor based on polarized SERS technique in conjunction with PCA-LDA provided a novel strategy for blood SERS analysis, and had the potential as a clinical complement for CRC screening.


Assuntos
Neoplasias Colorretais/diagnóstico , Análise Espectral Raman/métodos , Algoritmos , Coleta de Amostras Sanguíneas , Análise Discriminante , Humanos , Pessoa de Meia-Idade , Análise de Componente Principal , Probabilidade , Vibração
9.
Nano Lett ; 15(1): 75-9, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25545191

RESUMO

We demonstrate spatial probing of carrier transport within GaAs/AlGaAs core-shell nanowires with nanometer lateral resolution and subsurface sensitivity by energy-variable electron beam induced current imaging. Carrier drift that evolves with applied electric field is distinguished from a coupled drift-diffusion length. Along with simulation of injected electron trajectories, combining beam energy tuning with precise positioning for selective probing of core and shell reveals axial position- and bias-dependent differences in carrier type and transport along parallel conduction channels. These results indicate how analysis of transport within heterostructured nanomaterials is no longer limited to nonlocal or surface measurements.


Assuntos
Alumínio/química , Gálio/química , Nanofios/química , Elétrons
10.
Nanotechnology ; 26(6): 065101, 2015 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-25598539

RESUMO

Surface-enhanced Raman spectroscopy (SERS) is a powerful technology for providing finger-printing information of cells. A big challenge has been the long time duration and inefficient uptake of metal nano-particles into living cells as substrate for SERS analysis. Herein, a simple method (based on ultrasound) for the rapid transfer of silver nanoparticles (NPs) into living cells for intracellular SERS spectroscopy was presented. In this study, the ultrasound-mediated method for NP delivery overcame the shortcoming of 'passive uptake', and achieved quick acquisition of reproducible SERS spectra from living human nasopharyngeal carcinoma cell lines (C666 and CNE1) and normal nasopharyngeal cell line (NP69). Tentative assignment of the Raman bands in the measured SERS spectra showed cancer cell specific biomolecular differences, including significantly lower DNA concentrations and higher protein concentrations in cancerous nasopharyngeal cells as compared to those of normal cells. Combined with PCA-LDA multivariate analysis, ultrasound-mediated cell SERS spectroscopy differentiated the cancerous cells from the normal nasopharyngeal cells with high diagnostic accuracy (98.7%), demonstrating great potential for high-throughput cancer cell screening applications.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Ensaios de Triagem em Larga Escala/métodos , Nanopartículas Metálicas , Análise Espectral Raman/métodos , Ondas Ultrassônicas , Carcinoma , Linhagem Celular Tumoral , Humanos , Nanopartículas Metálicas/química , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/diagnóstico , Neoplasias/ultraestrutura , Prata
11.
Microsc Microanal ; 21(4): 855-62, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26036282

RESUMO

This work developed a phase congruency algorithm combined with texture analysis to quantitatively characterize collagen morphology in second-harmonic generation (SHG) images from human scars. The extracted phase and texture parameters of the SHG images quantified collagen directionality, homogeneity, and coarseness in scars and varied with scar duration. Phase parameters showed an increasing tendency of the mean of phase congruency with scar duration, indicating that collagen fibers are better oriented over time. Texture parameters calculated from local difference local binary pattern (LD-LBP) and Haar wavelet transform, demonstrated that the LD-LBP variance decreased and the energy of all subimages increased with scar duration. It implied that collagen has a more regular pattern and becomes coarser with scar duration. In addition, the random forest regression was used to predict scar duration, demonstrating reliable performance of the extracted phase and texture parameters in characterizing collagen morphology in scar SHG images. Results indicate that the extracted parameters using the proposed method can be used as quantitative indicators to monitor scar progression with time and can help understand the mechanism of scar progression.


Assuntos
Cicatriz/patologia , Colágeno/análise , Colágeno/ultraestrutura , Processamento de Imagem Assistida por Computador , Imagem Óptica , Humanos , Fatores de Tempo
12.
Nano Lett ; 14(1): 44-9, 2014 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-24063419

RESUMO

We report how a low vacuum pressure process followed by a few-minute annealing enables epitaxial stabilization, producing high-quality, phase-pure, single-crystalline epitaxial, and misfit dislocation-free BiFeO3(001) thin films on SrTiO3(001) at ∼450 °C less than current routes. These results unambiguously challenge the widely held notion that atomic layer deposition (ALD) is not appropriate for attaining high-quality chemically complex oxide films on perovskite substrates in single-crystalline epitaxial form, demonstrating applicability as an inexpensive, facile, and highly scalable route.

13.
J Cell Mol Med ; 18(7): 1344-57, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24758719

RESUMO

Toll-like receptors (TLR) recognize pathogens and trigger the production of vigorous pro-inflammatory cytokines [such as tumour necrosis factor (TNF)] that induce systemic damages associated with sepsis and chronic inflammation. Cooperation between signals of TLR and TNF receptor has been demonstrated through the participation of TNF receptor 1 (TNFR) adaptors in endotoxin tolerance. Here, we identify a TLR2-mediated synergy, through a MyD88-independent crosstalk, which enhances subsequent TNF-mediated nuclear factor-kappa B activation and interleukin-6 induction. Membrane-associated adaptor MAL conduces the link between TNF receptor-associated factor 6 (TRAF6) and TNFR-associated death domain, leading to a distinctive K63-ubiquitinylated TRAF6 recruitment into TNFR complex. In summary, our results reveal a novel route of TLR signal that synergistically amplifies TNF-mediated responses, indicating an innovative target for inflammation manipulation.


Assuntos
Regulação da Expressão Gênica , Interleucina-6/metabolismo , Fator 88 de Diferenciação Mieloide/fisiologia , Proteína de Domínio de Morte Associada a Receptor de TNF/fisiologia , Receptor 2 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/fisiologia , Animais , Western Blotting , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Humanos , Imunoprecipitação , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Interleucina-6/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/genética , NF-kappa B/metabolismo , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Receptor 2 Toll-Like/genética
14.
Nano Lett ; 13(9): 4152-7, 2013 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-23937245

RESUMO

Group III-V coaxial core-shell semiconducting nanowire heterostructures possess unique advantages over their planar counterparts in logic, photovoltaic, and light-emitting devices. Dimensional confinement of electronic carriers and interface complexity in nanowires are known to produce local electronic potential landscapes along the radial direction that deviate from those along the normal to planar heterojunction interfaces. However, understanding of selected electronic and optoelectronic carrier transport properties and device characteristics remains lacking without a direct measurement of band alignment in individual nanowires. Here, we report on, in the GaAs/AlxGa1-xAs and GaAs/AlAs core-shell nanowire systems, how photocurrent and photoluminescence spectroscopies can be used together to construct a band diagram of an individual heterostructure nanowire with high spectral resolution, enabling quantification of conduction band offsets.


Assuntos
Alumínio/química , Arsenicais/química , Gálio/química , Nanofios/química , Óptica e Fotônica , Semicondutores , Análise Espectral
15.
Chin Med J (Engl) ; 137(16): 1950-1956, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39039634

RESUMO

ABSTRACT: Interpreting genes of interest is essential for identifying molecular mechanisms, but acquiring such information typically involves tedious manual retrieval. To streamline this process, the fanyi package offers tools to retrieve gene information from sources like National Center for Biotechnology Information (NCBI), significantly enhancing accessibility. Additionally, understanding the latest research advancements and sharing achievements are crucial for junior researchers. However, language barriers often restrict knowledge absorption and career development. To address these challenges, we developed the fanyi package, which leverages artificial intelligence (AI)-driven online translation services to accurately translate among multiple languages. This dual functionality allows researchers to quickly capture and comprehend information, promotes a multilingual environment, and fosters innovation in academic community. Meanwhile, the translation functions are versatile and applicable beyond biomedicine research to other domains as well. The fanyi package is freely available at https://github.com/YuLab-SMU/fanyi .


Assuntos
Inteligência Artificial , Humanos , Barreiras de Comunicação , Idioma
16.
Analyst ; 138(14): 3967-74, 2013 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-23529624

RESUMO

Based on blood plasma surface-enhanced Raman spectroscopy (SERS) analysis, a simple and label-free blood test for non-invasive cervical cancer detection is presented in this paper. SERS measurements were performed on blood plasma samples from 60 cervical cancer patients and 50 healthy volunteers. Both the empirical approach and multivariate statistical techniques, including principal component analysis (PCA) and linear discriminant analysis (LDA), were employed to analyze and differentiate the obtained blood plasma SERS spectra. The empirical diagnostic algorithm based on the integration area of the SERS spectral bands (1310-1430 and 1560-1700 cm(-1)) achieved a diagnostic sensitivity of 70% and 83.3%, and a specificity of 76% and 78%, respectively, whereas the diagnostic algorithms based on PCA-LDA yielded a better diagnostic sensitivity of 96.7% and a specificity of 92% for separating cancerous samples from normal samples. This exploratory work demonstrates that a silver nanoparticle based SERS plasma analysis technique in conjunction with PCA-LDA has potential for improving cervical cancer detection and screening.


Assuntos
Células Sanguíneas/patologia , Imagem Óptica , Plasma/química , Análise Espectral Raman/métodos , Neoplasias do Colo do Útero/diagnóstico , Algoritmos , Estudos de Casos e Controles , Análise Discriminante , Detecção Precoce de Câncer , Feminino , Humanos , Análise dos Mínimos Quadrados , Nanopartículas Metálicas/química , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Componente Principal , Prata/química , Neoplasias do Colo do Útero/sangue
17.
Artigo em Inglês | MEDLINE | ID: mdl-37643105

RESUMO

Gene expression data can serve for analyzing the genes with changed expressions, the correlation between genes and the influence of different circumstance on gene activities. However, labeling a large number of gene expression data is laborious and time-consuming. The insufficient labeled data pose a challenge to construct the deep learning model. Currently, some graph neural networks (GNN) based on semi-supervised learning mechanism only focus on the feature space and sample space of gene expression data, possibly affecting the accuracy. This paper puts forward a novel semi-supervised graph neural network model (SFWN). Firstly, we use the external knowledge of gene expression data for constructing a feature graph, a similarity kernel, and a sample graph for the first time. Later, a novel semi-supervised learning algorithm (SGA) is proposed to extract the data relationship and obtain the global sample structure better. A graph sparse module (SGCN) is also proposed to process sparse representation with gene expression data classification. To overcome the over smoothing problem, a new feature calculation method based on two spaces is proposed to feature representation analysis and calculation in this model. According to a lot of experiments and ablation studies conducted on several public datasets, SFWN exhibits a better effect and is superior to the state-of-the-art approaches (the accuracy and F1-Score are 0.9993 and 0.9899, respectively). Experimental results showed that the proposed SFWN model has strong gene expression feature learning and representation ability, and may provide a new insight and tool for relevant disease diagnosis and clinic practice.

18.
Phys Med Biol ; 68(18)2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37619594

RESUMO

Objective. Structured illumination microscopy (SIM) is widely used in various fields of life science research. In clinical practice, it has low phototoxicity, fast imaging speed and no special fluorescent markers. However, SIM is still affected by the scattering medium of biological tissues, resulting in insufficient resolution of the obtained images, which limits the development of life sciences. A novel multi-frame wavelet generation adversarial network (MWGAN) is proposed to improve the scattering reconstruction capability of SIM.Approach. MWGAN is based on two components derived from the original image. A generative adversarial network constructed by wavelet transform is trained to reconstruct some complex details in the cell structure. Multi-frame adversarial network is used to obtain the inter-frame information of the image and use the complementary information of the before and after frames to improve the quality of the model reconstruction.Results. To demonstrate the robustness of MWGAN, multiple low-quality SIM image datasets are tested. Compared with the state-of-the-art methods, the proposed method achieves superior performance in both of the subjective and objective evaluation.Conclusion. MWGAN is effective for improving the clarity of SIM images. Meanwhile, the SIM images reconstructed by multiple frames improve the reconstruction quality of complex regions and allow clearer and dynamic observation of cellular functions.


Assuntos
Iluminação , Microscopia , Análise de Ondaletas
19.
IEEE Trans Neural Netw Learn Syst ; 34(12): 10294-10308, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35446770

RESUMO

With the development of artificial intelligence, speech recognition and prediction have become one of the important research domains with wild applications, such as intelligent control, education, individual identification, and emotion analysis. Chinese poetry reading contains rich features of continuous pronunciations, such as mood, emotion, rhythm schemes, lyric reading, and artistic expression. Therefore, the prediction of the pronunciation characteristics of a Chinese poetry reading is the significance for the presentation of high-level machine intelligence and has the potential to create a high-level intelligent system for teaching children to read Tang poetry. Mel frequency cepstral coefficient (MFCC) is currently used to present important speech features. Due to the complexity and high degree of nonlinearity in poetry reading, however, there is a tough challenge facing accurate pronunciation feature prediction, that is, how to model complex spatial correlations and time dynamics, such as rhyme schemes. As for many current methods, they ignore the spatial and temporal characteristics in MFCC presentation. In addition, these methods are subjected to certain limitations on prediction for long-term performance. In order to solve these problems, we propose a novel spatial-temporal graph model (STGM-MHA) based on multihead attention for the purpose of pronunciation feature prediction of Chinese poetry. The STGM-MHA is designed using an encoder-decoder structure. The encoder compresses the data into a hidden space representation, while the decoder reconstructs the hidden space representation as output. In the model, a novel gated recurrent unit (GRU) module (AGRU) based on multihead attention is proposed to extract the spatial and temporal features of MFCC data effectively. The evaluation comparison of our proposed model versus state-of-the-art methods in six datasets reveals the clear advantage of the proposed model.


Assuntos
Inteligência Artificial , Idioma , Emoções , Redes Neurais de Computação , Poesia como Assunto
20.
Front Immunol ; 14: 1090202, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36798132

RESUMO

Background: Inhibition of sphingosine kinase 1 (SphK1), which catalyzes bioactive lipid sphingosine-1-phosphate (S1P), attenuates NLRP3 inflammasome activation. S1P exerts most of its function by binding to S1P receptors (S1PR1-5). The roles of S1P receptors in NLRP3 inflammasome activation remain unclear. Materials and methods: The mRNA expressions of S1PRs in bone marrow-derived macrophages (BMDMs) were measured by real-time quantitative polymerase chain reaction (qPCR) assays. BMDMs were primed with LPS and stimulated with NLRP3 activators, including ATP, nigericin, and imiquimod. Interleukin-1ß (IL-1ß) in the cell culture supernatant was detected by enzyme-linked immunosorbent assay (ELISA). Intracellular potassium was labeled with a potassium indicator and was measured by confocal microscopy. Protein expression in whole-cell or plasma membrane fraction was measured by Western blot. Cecal ligation and puncture (CLP) was induced in C57BL/6J mice. Mortality, lung wet/dry ratio, NLRP3 activation, and bacterial loads were measured. Results: Macrophages expressed all five S1PRs in the resting state. The mRNA expression of S1PR3 was upregulated after lipopolysaccharide (LPS) stimulation. Inhibition of S1PR3 suppressed NLRP3 and pro-IL-1ß in macrophages primed with LPS. Inhibition of S1PR3 attenuated ATP-induced NLRP3 inflammasome activation, enhanced nigericin-induced NLRP3 activation, and did not affect imiquimod-induced NLRP3 inflammasome activation. In addition, inhibition of S1PR3 suppressed ATP-induced intracellular potassium efflux. Inhibition of S1PR3 did not affect the mRNA or protein expression of TWIK2 in LPS-primed BMDMs. ATP stimulation induced TWIK2 expression in the plasma membrane of LPS-primed BMDMs, and inhibition of S1PR3 impeded the membrane expression of TWIK2 induced by ATP. Compared with CLP mice treated with vehicle, CLP mice treated with the S1PR3 antagonist, TY52156, had aggravated pulmonary edema, increased bacterial loads in the lung, liver, spleen, and blood, and a higher seven-day mortality rate. Conclusions: Inhibition of S1PR3 suppresses the expression of NLRP3 and pro-IL-1ß during LPS priming, and attenuates ATP-induced NLRP3 inflammasome activation by impeding membrane trafficking of TWIK2 and potassium efflux. Although inhibition of S1PR3 decreases IL-1ß maturation in the lungs, it leads to higher bacterial loads and mortality in CLP mice.


Assuntos
Inflamassomos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Animais , Camundongos , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Receptores de Esfingosina-1-Fosfato/metabolismo , Potássio/metabolismo , Imiquimode , Nigericina/farmacologia , Camundongos Endogâmicos C57BL , Macrófagos/metabolismo , Trifosfato de Adenosina/metabolismo , RNA Mensageiro/metabolismo
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