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1.
J Org Chem ; 2024 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-39356286

RESUMEN

Photoresponsive multicolor luminescent systems offer interesting functions, which have led to applications in anticounterfeiting and biological imaging. However, expanding the color range of these materials remains a challenging task. Herein, a carbazole-modified dithienylethene derivative (DTE-CZ) that exhibits modulated fluorescence color changes through the photocyclization reaction and photolysis reaction is synthesized. DTE-CZ emits orange fluorescence, and it can release a fluorophore which emits blue fluorescence by the photolysis reaction, resulting in the color change. Upon complexation of DTE-CZ with cucurbit[10]uril (CB[10]), the fluorescence wavelength will have a blue shift and the photolysis reaction will be inhibited. Benefiting from the influence of CB[10] and the photolysis reaction of free guests, the color range of the photoresponsive system which is composed of free guests and host-guest complexes is further extended. White light emission along with a color shift from yellow-green to blue was achieved by adjusting the ratio of free guests to host-guest complexes. Finally, the photoresponsive multicolor systems are utilized to construct a photostimulated PVA film and an information encryption system. This work provides an alternative strategy for the preparing of photoresponsive multicolor luminescent system and modulation of its color range.

2.
Sensors (Basel) ; 24(16)2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-39204868

RESUMEN

A snapshot multi-wavelength birefringence imaging measurement method was proposed in this study. The RGB-LEDs at wavelengths 463 nm, 533 nm, and 629 nm were illuminated with circularly polarized light after passing through a circular polarizer. The transmitted light through the birefringent sample was captured by a color polarization camera. A single imaging process captured light intensity in four polarization directions (0°, 45°, 90°, and 135°) for each of the three RGB spectral wavelength channels, and subsequently measured the first three elements of Stokes vectors (S0, S1, and S2) after the sample. The birefringence retardance and fast-axis azimuthal angle were determined simultaneously. An experimental setup was constructed, and polarization response matrices were calibrated for each spectral wavelength channel to ensure the accurate detection of Stokes vectors. A polymer true zero-order quarter-wave plate was employed to validate measurement accuracy and repeatability. Additionally, stress-induced birefringence in a PMMA arch-shaped workpiece was measured both before and after the application of force. Experimental results revealed that the repeatability of birefringence retardance and fast-axis azimuthal angle was better than 0.67 nm and 0.08°, respectively. This approach enables multispectral wavelength, high-speed, high-precision, and high-repeatability birefringence imaging measurements through a single imaging session.

3.
Sci Rep ; 14(1): 15310, 2024 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-38961136

RESUMEN

Human activity recognition has a wide range of applications in various fields, such as video surveillance, virtual reality and human-computer intelligent interaction. It has emerged as a significant research area in computer vision. GCN (Graph Convolutional networks) have recently been widely used in these fields and have made great performance. However, there are still some challenges including over-smoothing problem caused by stack graph convolutions and deficient semantics correlation to capture the large movements between time sequences. Vision Transformer (ViT) is utilized in many 2D and 3D image fields and has surprised results. In our work, we propose a novel human activity recognition method based on ViT (HAR-ViT). We integrate enhanced AGCL (eAGCL) in 2s-AGCN to ViT to make it process spatio-temporal data (3D skeleton) and make full use of spatial features. The position encoder module orders the non-sequenced information while the transformer encoder efficiently compresses sequence data features to enhance calculation speed. Human activity recognition is accomplished through multi-layer perceptron (MLP) classifier. Experimental results demonstrate that the proposed method achieves SOTA performance on three extensively used datasets, NTU RGB+D 60, NTU RGB+D 120 and Kinetics-Skeleton 400.


Asunto(s)
Actividades Humanas , Humanos , Redes Neurales de la Computación , Algoritmos , Reconocimiento de Normas Patrones Automatizadas/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos
4.
Sensors (Basel) ; 24(9)2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38732964

RESUMEN

Motion object detection (MOD) with freely moving cameras is a challenging task in computer vision. To extract moving objects, most studies have focused on the difference in motion features between foreground and background, which works well for dynamic scenes with relatively regular movements and variations. However, abrupt illumination changes and occlusions often occur in real-world scenes, and the camera may also pan, tilt, rotate, and jitter, etc., resulting in local irregular variations and global discontinuities in motion features. Such complex and changing scenes bring great difficulty in detecting moving objects. To solve this problem, this paper proposes a new MOD method that effectively leverages local and global visual information for foreground/background segmentation. Specifically, on the global side, to support a wider range of camera motion, the relative inter-frame transformations are optimized to absolute transformations referenced to intermediate frames in a global form after enriching the inter-frame matching pairs. The global transformation is fine-tuned using the spatial transformer network (STN). On the local side, to address the problem of dynamic background scenes, foreground object detection is optimized by utilizing the pixel differences between the current frame and the local background model, as well as the consistency of local spatial variations. Then, the spatial information is combined using optical flow segmentation methods, enhancing the precision of the object information. The experimental results show that our method achieves a detection accuracy improvement of over 1.5% compared with the state-of-the-art methods on the datasets of CDNET2014, FBMS-59, and CBD. It demonstrates significant effectiveness in challenging scenarios such as shadows, abrupt changes in illumination, camera jitter, occlusion, and moving backgrounds.

5.
Sci Rep ; 14(1): 5560, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448683

RESUMEN

Deformable attention only focuses on a small group of key sample-points around the reference point and make itself be able to capture dynamically the local features of input feature map without considering the size of the feature map. Its introduction into point cloud registration will be quicker and easier to extract local geometric features from point cloud than attention. Therefore, we propose a point cloud registration method based on Spatial Deformable Transformer (SDT). SDT consists of a deformable self-attention module and a cross-attention module where the deformable self-attention module is used to enhance local geometric feature representation and the cross-attention module is employed to enhance feature discriminative capability of spatial correspondences. The experimental results show that compared to state-of-the-art registration methods, SDT has a better matching recall, inlier ratio, and registration recall on 3DMatch and 3DLoMatch scene, and has a better generalization ability and time efficiency on ModelNet40 and ModelLoNet40 scene.

6.
J Org Chem ; 88(17): 12376-12384, 2023 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-37610314

RESUMEN

A series of naphthalimide derivatives are synthesized and their binding behavior upon complexation with cucurbit[n]urils (CB[n]s) has been investigated. With a heavy atom (bromine) on the naphthalimide core, 4-bromo-1,8-naphthalimide derivatives 1-4 show short room-temperature phosphorescence (RTP) lifetimes with low quantum yields. Their RTP properties are significantly enhanced in the presence of CB[8] or CB[10] both in aqueous solution and solid state owing to the efficient suppression of nonradiative decay and isolation of quenching factors by the rigid cavity of CB[n]. Without the bromine atom, 1,8-naphthalimide derivatives 5 and 6 show strong excimer emission upon complexation with CB[10] accompanied by fluorescence transition from blue to cyan. The fluorescence colors of 4-(dimethylamino)-1,8-naphthalimide derivatives 7 and 8 change from blue to white to yellow with the addition of CB[n]. This host-guest complexation strategy to modulate the luminescence of the luminophore would further broaden the application of luminescent materials.

7.
Sensors (Basel) ; 23(12)2023 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-37420785

RESUMEN

With the advancement of robotics, the field of path planning is currently experiencing a period of prosperity. Researchers strive to address this nonlinear problem and have achieved remarkable results through the implementation of the Deep Reinforcement Learning (DRL) algorithm DQN (Deep Q-Network). However, persistent challenges remain, including the curse of dimensionality, difficulties of model convergence and sparsity in rewards. To tackle these problems, this paper proposes an enhanced DDQN (Double DQN) path planning approach, in which the information after dimensionality reduction is fed into a two-branch network that incorporates expert knowledge and an optimized reward function to guide the training process. The data generated during the training phase are initially discretized into corresponding low-dimensional spaces. An "expert experience" module is introduced to facilitate the model's early-stage training acceleration in the Epsilon-Greedy algorithm. To tackle navigation and obstacle avoidance separately, a dual-branch network structure is presented. We further optimize the reward function enabling intelligent agents to receive prompt feedback from the environment after performing each action. Experiments conducted in both virtual and real-world environments have demonstrated that the enhanced algorithm can accelerate model convergence, improve training stability and generate a smooth, shorter and collision-free path.


Asunto(s)
Robótica , Recompensa , Aceleración , Algoritmos , Inteligencia
8.
Nat Commun ; 14(1): 4190, 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37443180

RESUMEN

Developing more extensive methods to understand the underlying structure-property relationship of mechanochromic luminescent molecules is demanding but remains challenging. Herein, the effect of host-guest interaction on the mechanochromic properties of organic molecules is illustrated. A series of pyridinium-functionalized triphenylamine derivatives show bathochromic-shifted emission upon mechanical stimulation. These derivatives bind to cucurbit[8]uril to form homoternary host-guest inclusion complexes through host-stabilized intermolecular charge transfer interactions. Remarkably, the homoternary complexes exhibit longer emission than that of free guests in the solid state (even longer than ground guests), and a further bathochromic-shifted emission is observed upon grinding. Additionally, a heteroternary complex constructed through the encapsulation of pyrene (donor) and pyridinium (acceptor) guest pair in cucurbit[8]uril also displays the mechanochromic luminescent property. This work not only discloses the effect of host-guest inclusion on the mechanochromic property of organic molecules, but also provides a principle and a facile way to design the sequentially red-shifted mechanochromic materials.

9.
Chem Sci ; 13(24): 7247-7255, 2022 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-35799817

RESUMEN

Aqueous room temperature phosphorescence (aRTP) from purely organic materials has been intriguing but challenging. In this article, we demonstrated that the red aRTP emission of 2Br-NDI, a water-soluble 4,9-dibromonaphthalene diimide derivative as a chloride salt, could be modulated by anion-π and intermolecular electronic coupling interactions in water. Specifically, the rarely reported stabilization of anion-π interactions in water between Cl- and the 2Br-NDI core was experimentally evidenced by an anion-π induced long-lived emission (λ Anion-π) of 2Br-NDI, acting as a competitive decay pathway against the intrinsic red aRTP emission (λ Phos) of 2Br-NDI. In the initial expectation of enhancing the aRTP of 2Br-NDI by inclusion complexation with macrocyclic cucurbit[n]urils (CB[n]s, n = 7, 8, 10), we surprisingly found that the exclusion complexation between CB[8] and 2Br-NDI unconventionally endowed the complex with the strongest and longest-lived aRTP due to the strong intermolecular electronic coupling between the nπ* orbit on the carbonyl rims of CB[8] and the ππ* orbit on 2Br-NDI in water. It is anticipated that these intriguing findings may inspire and expand the exploration of aqueous anion-π recognition and CB[n]-based aRTP materials.

10.
J Oncol ; 2022: 8016102, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35571491

RESUMEN

Background: The HOX gene family of transcription factors, characterized by conserved homeodomains, is positively correlated with the resistance to chemotherapy drugs and poor prognosis, as well as the initiating potential of gliomas. However, there are few studies regarding the HOXC6 gene in glioma cells. Therefore, in the present study, we explored the regulatory roles and detailed mechanisms underlying the relationship between HOXC6 and the progression of GBM. Methods: The expression levels and prognostic value of HOXC6 in GBM were evaluated using the data obtained from the GCCA, GEPIA, and ONCOMINE databases. The relationship between GBM prognosis and levels of HOXC6 was identified using Kaplan-Meier curves. The protein levels of HOXC6 in GBM and adjacent normal tissues were identified via Western blot and immunohistochemistry (IHC) staining methods. Lentiviruses containing full-length HOXC6 and HOXC6 specific siRNA sequences were used to overexpress and knock down, respectively, the expression of HOXC6 in U87 and U251 cells. The role of HOXC6 in the regulation of migration and proliferation of GBM cells was accessed using Transwell, wound healing, CCK-8, and colony formation assays. The activation of the TGF-ß/Smad signaling pathway was detected via Western blotting. Results: Compared to normal tissues and control cells, GBM tissues and cell lines showed higher expressions of HOXC6. The expression of HOXC6 was associated with disease-free and the overall survival of GBM patients. Additionally, positive correlations between the expression of HOXC6 and the migration and proliferation of GBM cells were observed in vitro. The mechanistic analyses indicated that HOXC6 exerts its promotive effect on the progression and invasion of glioma cells by promoting the activation of the EMT and TGF-ß/Smad signaling pathways. Conclusions: HOXC6 enhances the migration and proliferation of GBM by activating the EMT signaling pathway.

11.
Ecotoxicol Environ Saf ; 236: 113500, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35421827

RESUMEN

Fluoride is capable of inducing developmental neurotoxicity, yet its mechanisms remain elusive. We aimed to explore the possible role and mechanism of autophagic flux blockage caused by abnormal lysosomal pH in fluoride-induced developmental neurotoxicity, focusing on the role of V-ATPase in regulating the neuronal lysosomal pH. Using Sprague-Dawley rats exposed to sodium fluoride (NaF) from gestation through delivery until the neonatal offspring reached six months of age as an in vivo model. The results showed that NaF impaired the cognitive abilities of the offspring rats. In addition, NaF reduced V-ATPase expression, diminished lysosomal degradation capacity and blocked autophagic flux, and increased apoptosis in the hippocampus of offspring. Consistently, these results were validated in SH-SY5Y cells incubated with NaF. Moreover, NaF increased the SH-SY5Y lysosomal pH. Mechanistically, V-ATPase B2 overexpression and ATP effectively restored V-ATPase expression, reducing NaF-induced lysosomal alkalinization while increasing lysosomal degradation capacity. Notably, those above pharmacological and molecular interventions diminished NaF-induced apoptosis by restoring autophagic flux. Collectively, the present findings suggested that NaF impairs the lysosomal pH raised by V-ATPase. This leads to reduced lysosomal degradation capacity and triggers autophagic flux blockage and apoptosis, thus contributing to neuronal death. Therefore, V-ATPase might be a promising indicator of developmental fluoride neurotoxicity.


Asunto(s)
Fluoruros , Síndromes de Neurotoxicidad , Adenosina Trifosfatasas/metabolismo , Animales , Autofagia , Fluoruros/metabolismo , Concentración de Iones de Hidrógeno , Lisosomas , Síndromes de Neurotoxicidad/etiología , Síndromes de Neurotoxicidad/metabolismo , Ratas , Ratas Sprague-Dawley , Fluoruro de Sodio/toxicidad
12.
Medicine (Baltimore) ; 101(2): e28576, 2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35029231

RESUMEN

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) of high-frequency (10 Hz) on suprahyoid motor cortex has been an evidence-based treatment for poststroke dysphagia. Intermittent theta burst stimulation (iTBS) can be performed in 3 minutes compared with 20 ±â€Š5 minutes for 10 Hz rTMS. This study aimed to ensure the clinical efficacy, safety, and tolerability of iTBS compared with 10 Hz rTMS for patients with poststroke dysphagia. METHOD: In this randomized, double-blind, single-center, controlled trial, 47 participants were randomly assigned to iTBS (n = 24) and rTMS (n = 23) group. Each participant received iTBS or rTMS daily at suprahyoid motor cortex of affected hemisphere for 10 consecutive days. The outcomes were assessed at baseline, immediately, and 2 weeks after intervention, including water-swallowing test, standardized swallowing assessment, Mann assessment of swallowing ability, Murray Secretion Scale, Yale Pharyngeal Residue Severity Rating Scale, Penetration-Aspiration Scale, and motor evoked potential (MEP) of bilateral suprahyoid muscle. RESULTS: There were no significant differences between groups. There was a significant improvement on all rating scales and MEP after rTMS and iTBS. No significant differences on water-swallowing test, Mann assessment of swallowing ability, standardized swallowing assessment, Murray Secretion Scale scores, and MEP were observed between groups. In particular, there was significant differences on Penetration-Aspiration Scale scores (viscous liquid: mean difference = 1.016; 95% CI: 0.32-1.71; effect size: 0.360; P = .005) and the residue rate of pyriform fossa (viscous liquid: mean difference = 0.732; 95% CI: 0.18-1.28; effect size: 0.248; P = .010) in between-group. Comparing the differences over the changes of all rating scales, only the residue rate of epiglottis valley between groups was found to be significantly different (dilute liquid: mean difference = -0.567; 95% CI: -0.98 to -0.15; P = .009). There was no severe adverse effect and high dropout rates in both groups. CONCLUSION: The clinical efficacy, safety, and tolerability of iTBS showed non-inferior to 10 Hz rTMS for patients with poststroke dysphagia. The present study can be used to improve the clinicians' knowledge and clinical decision skills on iTBS and rTMS for poststroke dysphagia.


Asunto(s)
Trastornos de Deglución , Corteza Motora , Accidente Cerebrovascular/complicaciones , Estimulación Magnética Transcraneal , Trastornos de Deglución/etiología , Trastornos de Deglución/terapia , Método Doble Ciego , Potenciales Evocados Motores , Humanos , Estimulación Magnética Transcraneal/métodos
13.
Ecotoxicol Environ Saf ; 230: 113108, 2022 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-34953272

RESUMEN

Fluoride is capable of inducing developmental neurotoxicity, but the mechanisms involved remain unclear. We aimed to explore the role of autophagosome-lysosome fusion in developmental fluoride neurotoxicity, particularly focusing on the interaction between ATG14 and the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex. We developed in vivo models of Sprague-Dawley rats exposed to sodium fluoride (NaF) from the pregnancy of parental rats until the offspring were two months old and in vitro models of NaF and/or Ad-ATG14-treated SH-SY5Y cells. We assessed neurobehavioral changes in offspring and further investigated the effects of NaF exposure on autophagic flux, apoptosis, autophagosome-lysosome fusion, and the interaction between ATG14 and the SNARE complex. NaF exposure impaired offspring learning and memory capabilities and induced the accumulation of autophagosomes and autophagic flux blockage and apoptosis, as indicated by increased LC3-II, p62, and cleaved-caspase-3 expression in vivo and in vitro. In addition, NaF treatment downregulated the protein expression of ATG14 and the SNARE complex and induced autophagosome-lysosome fusion blockage as evidenced by decreased ATG14, STX17, SNAP29, and VAMP8 expression and diminished colocalization of autophagosomes and lysosomes in vivo and in vitro. Furthermore, ATG14 upregulation enhanced the interaction of ATG14 and the SNARE complex to facilitate autophagosome-lysosome fusion, thereby restoring autophagic flux and alleviating NaF-induced apoptosis. In conclusion, NaF exhibited developmental neurotoxicity by restraining the interaction of ATG14 with the SNARE complex and hindering autophagosome-lysosome fusion, thereby participating in the occurrence and development of fluoride neurotoxicity. Notably, ATG14 upregulation protects against developmental fluoride neurotoxicity, and ATG14 may serve as a promising biomarker for further epidemiological investigation.

14.
Chemistry ; 27(65): 16153-16160, 2021 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-34533250

RESUMEN

Diarylethene (DTE) has been widely used in fluorescence probes, molecular logic gates, optical data-storage devices owing to the excellent photochromic property, while constructing high-performance photochromic DTE in aqueous media remains a big challenge. Herein we present several host-guest systems formed between cucurbit[n]uril (CB[n], n=7, 8, 10) and two water-soluble DTE derivatives 1 and 2. It was found that host-guest interactions not only affect the photophysical properties of photochromic guests, but also make great differences on the photoreaction process. Different host-guest binding behaviors also lead to different effects on the photochromic properties of guests. In the presence of CB[n], both 1 and 2 showed enhanced emission and higher fluorescence quenching ratio at photostationary state. Besides, CB[10]⋅1 exhibited faster response rate in cyclization reaction and better photofatigue resistance than free 1 in aqueous solution, while the supramolecular assembly of (CB[8])n ⋅(2)n showed slower response rate in both directions of the reversible photoreaction. Besides, the photofatigue resistance of 2 can be greatly improved through binding with CB[7]. Our results suggest that host-guest interactions could be an efficient way to improve photochromic properties of DTE in aqueous solution.


Asunto(s)
Hidrocarburos Aromáticos con Puentes , Imidazoles , Fluorescencia , Colorantes Fluorescentes , Agua
15.
Org Lett ; 23(17): 6633-6637, 2021 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-34409834

RESUMEN

Cucurbit[n]uril (CB[n])-mediated assembly of π-conjugated azapyrene derivatives with rigid aromatic rings as bridging units into optically tunable complexes is reported. Due to the hindrance of rotation of diazapyrene moieties and the enhancement of intramolecular charge transfer of chromophore guests within the cavity of the CB[8] host, color tuning including white-light emission was easily achieved by introducing CB[8] into the guest aqueous solution, therefore suggesting a feasible strategy for the creation of tunable white-light emission materials through CB[n]-based host-guest interactions.

16.
Front Aging Neurosci ; 12: 188, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32733231

RESUMEN

Current researches on default mode network (DMN) in normal elderly have mainly focused on finding some dysfunctional areas with decreased or increased connectivity. The global network dynamics of apolipoprotein E (APOE) e4 allele group is rarely studied. In our previous brain network study, we have demonstrated the advantage of persistent homology. It can distinguish robust and noisy topological features over multiscale nested networks, and the derived properties are more stable. In this study, for the first time we applied persistent homology to analyze APOE-related effects on whole-brain functional network. In our experiments, the risk allele group exhibited lower network radius and modularity in whole brain DMN based on graph theory, suggesting the abnormal organization structure. Moreover, two suggested measures from persistent homology detected significant differences between groups within the left hemisphere and in the whole brain in two datasets. They were more statistically sensitive to APOE genotypic differences than standard graph-based measures. In summary, we provide evidence that the e4 genotype leads to distinct DMN functional alterations in the early phases of Alzheimer's disease using persistent homology approach. Our study offers a novel insight to explore potential biomarkers in healthy elderly populations carrying APOE e4 allele.

17.
J Org Chem ; 84(22): 14498-14507, 2019 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-31524391

RESUMEN

Functional molecules with aggregation-induced emission (AIE) have lately received the most attention due to their versatile functions in many fields. In this work, tetraphenylethene (TPE) as one of the most discussed AIE system was installed on different fluorophores including dansyl, naphthalimide, 4-nitro-1,2,3-benzoxadiazole (NBD), borondipyrromethene, and hemicyanine to afford a series of new fluorescent dyes, whose spectra covered the fluorescence region of the visible to near-infrared emission. Especially, these tetraphenylethene-containing compounds all exhibited AIE behavior. In solid state, they presented multiple colors including blue, orange, red, crimson, and NIR (near-infrared emission). It was worth mentioning that the dansyl- and NBD-coated TPEs exhibited obvious mechanoresponsive luminescence phenomena. Moreover, these AIE-based TPEs displayed a good bioimaging performance in living cells. This work will be helpful for designing functional AIE dyes with different fluorescence emission.


Asunto(s)
Colorantes Fluorescentes/química , Imagen Óptica , Estilbenos/química , Teoría Funcional de la Densidad , Colorantes Fluorescentes/síntesis química , Células HeLa , Humanos , Luz , Estructura Molecular , Estilbenos/síntesis química
18.
Molecules ; 24(12)2019 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-31234358

RESUMEN

Recent research of persistent homology in algebraic topology has shown that the altered network organization of human brain provides a promising indicator of many neuropsychiatric disorders and neurodegenerative diseases. However, the current slope-based approach may not accurately characterize changes of persistent features over graph filtration because such curves are not strictly linear. Moreover, our previous integrated persistent feature (IPF) works well on an rs-fMRI cohort while it has not yet been studied on metabolic brain networks. To address these issues, we propose a novel univariate network measurement, kernel-based IPF (KBI), based on the prior IPF, to quantify the difference between IPF curves. In our experiments, we apply the KBI index to study fluorodeoxyglucose positron emission tomography (FDG-PET) imaging data from 140 subjects with Alzheimer's disease (AD), 280 subjects with mild cognitive impairment (MCI), and 280 healthy normal controls (NC). The results show the disruption of network integration in the progress of AD. Compared to previous persistent homology-based measures, as well as other standard graph-based measures that characterize small-world organization and modular structure, our proposed network index KBI possesses more significant group difference and better classification performance, suggesting that it may be used as an effective preclinical AD imaging biomarker.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Redes y Vías Metabólicas , Anciano , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/patología , Encéfalo/diagnóstico por imagen , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/patología , Femenino , Fluorodesoxiglucosa F18/administración & dosificación , Humanos , Imagen por Resonancia Magnética , Masculino , Tomografía de Emisión de Positrones
19.
Appl Opt ; 58(16): 4271-4276, 2019 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-31251229

RESUMEN

To realize high-speed, accurate, and sensitive measurement of electro-optic (EO) coefficients, a novel measurement method using photoelastic modulation is proposed. A simple polarimetry is constructed based on the photoelastic modulator, and the phase difference induced by the EO sample is loaded in the modulation signals. Employing the digital phase-locked technology, the DC, first, and second harmonic terms are extracted, respectively, and then the EO coefficients are demodulated. The experimental system is set up to analyze the principle of this scheme in detail. A Y-cut LiNbO3 crystal plate is selected as the sample, and the EO coefficient γ22 is studied under different applied DC voltages. The results demonstrate that the measurement accuracy and sensitivity of the system are 0.22% and 1.5×10-14 m/V, respectively, when the sampling time is set as 198.9 ms. The measuring rate can be further enhanced, if the appropriate reduction of the measurement sensitivity is allowed.

20.
Chem Asian J ; 14(6): 890-895, 2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30702806

RESUMEN

A tetraphenylethene (TPE) derivative substituted with a sulfonyl-based naphthalimide unit (TPE-Np) was designed and synthesized. Its optical properties in solution and in the solid state were investigated. Photophysical properties indicated that the target molecule, TPE-Np, possessed aggregation-induced emission (AIE) behavior, although the linkage between TPE and the naphthalimide unit was nonconjugated. Additionally, it exhibited an unexpected, highly reversible mechanochromism in the solid state, which was attributed to the change in manner of aggregation between crystalline and amorphous states. On the other hand, a solution of TPE-Np in a mixture of dimethyl sulfoxide/phosphate-buffered saline was capable of efficiently distinguishing glutathione (GSH) from cysteine and homocysteine in the presence of cetyltrimethylammonium bromide. Furthermore, the strategy of using poly(ethylene glycol)-polyethylenimine (PEG-PEI) nanogel as a carrier to cross-link TPE-Np to obtain a water-soluble PEG-PEI/TPE-Np nanoprobe greatly improved the biocompatibility, and this nanoprobe could be successfully applied in the visualization of GSH levels in living cells.


Asunto(s)
Colorantes Fluorescentes/química , Glutatión/análisis , Naftalimidas/química , Estilbenos/química , Sulfonamidas/química , Cisteína/química , Colorantes Fluorescentes/síntesis química , Glutatión/química , Humanos , Células MCF-7 , Microscopía Confocal , Nanogeles , Polietilenglicoles/química , Polietileneimina/análogos & derivados , Polietileneimina/química , Teoría Cuántica , Espectrometría de Fluorescencia
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