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1.
Proc Natl Acad Sci U S A ; 119(43): e2208506119, 2022 10 25.
Artículo en Inglés | MEDLINE | ID: mdl-36256824

RESUMEN

DNA-damaging treatments such as radiotherapy (RT) have become promising to improve the efficacy of immune checkpoint inhibitors by enhancing tumor immunogenicity. However, accompanying treatment-related detrimental events in normal tissues have posed a major obstacle to radioimmunotherapy and present new challenges to the dose delivery mode of clinical RT. In the present study, ultrahigh dose rate FLASH X-ray irradiation was applied to counteract the intestinal toxicity in the radioimmunotherapy. In the context of programmed cell death ligand-1 (PD-L1) blockade, FLASH X-ray minimized mouse enteritis by alleviating CD8+ T cell-mediated deleterious immune response compared with conventional dose rate (CONV) irradiation. Mechanistically, FLASH irradiation was less efficient than CONV X-ray in eliciting cytoplasmic double-stranded DNA (dsDNA) and in activating cyclic GMP-AMP synthase (cGAS) in the intestinal crypts, resulting in the suppression of the cascade feedback consisting of CD8+ T cell chemotaxis and gasdermin E-mediated intestinal pyroptosis in the case of PD-L1 blocking. Meanwhile, FLASH X-ray was as competent as CONV RT in boosting the antitumor immune response initiated by cGAS activation and achieved equal tumor control in metastasis burdens when combined with anti-PD-L1 administration. Together, the present study revealed an encouraging protective effect of FLASH X-ray upon the normal tissue without compromising the systemic antitumor response when combined with immunological checkpoint inhibitors, providing the rationale for testing this combination as a clinical application in radioimmunotherapy.


Asunto(s)
Neoplasias , Radioinmunoterapia , Ratones , Animales , Rayos X , Piroptosis , Inhibidores de Puntos de Control Inmunológico , Ligandos , Nucleotidiltransferasas/metabolismo
2.
Int J Biometeorol ; 68(3): 445-459, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38127126

RESUMEN

Over the past few years, there has been a significant focus on air pollution due to its various detrimental effects on human health. However, its influence on people's tendency to have children remains uncertain, as only a few studies have examined the correlation between public perception of air pollution and the desire to start a family. This article introduces a theoretical framework utilizing a two-stage interval iteration model to explore the connection between children's relative utility and the perception of air pollution. Data for this study were gathered from the "Chinese General Social Survey" (CGSS 2013). The CGSS 2013 project employed a four-stage stratified random sampling technique and conducted household interviews using questionnaires. The sample covered 28 provincial-level cities across China. The hypothesis was tested using a Probit regression model. The findings indicate that individuals considering air pollution a significant issue are 8.62% less likely to have more than one child. The variation in fertility desire sensitivity to air pollution points to heterogeneity among residents, such as registered residents and those living in various residential areas, as well as individuals with different characteristics like education levels. The study concludes that air quality significantly influences human fertility desire, highlighting the urgent necessity to raise awareness of environmental protection issues among both the public and authorities. In particular, there are two key steps to address this issue. Firstly, the government should establish clear air pollution control objectives and refine policies to enhance governance efficiency. Secondly, there is a need to encourage environmentally friendly behaviours among the public, promote more significant involvement in public environmental matters, and ensure effective oversight of the government's responsibilities in managing air pollution.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Niño , Humanos , Opinión Pública , Contaminación del Aire/análisis , Ciudades , Proyectos de Investigación , Conservación de los Recursos Naturales , China , Contaminantes Atmosféricos/análisis
3.
Chem Soc Rev ; 52(20): 7071-7136, 2023 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-37755573

RESUMEN

Porous crystalline materials usually include metal-organic frameworks (MOFs), covalent organic frameworks (COFs), hydrogen-bonded organic frameworks (HOFs) and zeolites, which exhibit exceptional porosity and structural/composition designability, promoting the increasing attention in memory and neuromorphic computing systems in the last decade. From both the perspective of materials and devices, it is crucial to provide a comprehensive and timely summary of the applications of porous crystalline materials in memory and neuromorphic computing systems to guide future research endeavors. Moreover, the utilization of porous crystalline materials in electronics necessitates a shift from powder synthesis to high-quality film preparation to ensure high device performance. This review highlights the strategies for preparing porous crystalline materials films and discusses their advancements in memory and neuromorphic electronics. It also provides a detailed comparative analysis and presents the existing challenges and future research directions, which can attract the experts from various fields (e.g., materials scientists, chemists, and engineers) with the aim of promoting the applications of porous crystalline materials in memory and neuromorphic computing systems.

4.
Opt Express ; 31(22): 35519-35528, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-38017720

RESUMEN

Benefitting from the inherent merits of tiny volume, customizable performance, good system compatibility and high-yield production, micro-electro-mechanical-system-based Fabry-Perot filtering chip (MEMS-FPFC) with a large aperture size gives a feasible way for the realization of miniaturized spectral imagers which can serve in many civilian and military scenarios. Although the aperture size of MEMS-FPFCs in mid-wave and long-wave infrared has reached to the centimeter scale, that of visible wavelength (VIS) MEMS-FPFC is always unsatisfied which is mainly limited by micromachining stress, especially in the thin films. In this work, we propose a large-aperture electromagnetically actuated MEMS-FPFC based on Si3N4 supporting membrane for VIS spectral imaging, which is designed with the assistance of multi-field coupling simulation model. A low-stress wafer-scale bulk micromachining process is developed to guarantee the high-quality and high-yield production for the aimed VIS MEMS-FPFCs. Finally, by the strictly controlling and rationally allocating the film stress of multi-layer film stack, VIS MEMS-FPFCs with 6 mm aperture size are thus developed, which can be tuned bidirectionally and continuously in 612-678 nm waveband with a good linear response of better than 95%. The achieved VIS MEMS-FPFCs can be utilized to construct miniaturized spectral imagers directly, aiming for such applications as intelligent agriculture, environmental protection and industrial inspection.

5.
Small ; 18(16): e2200185, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35218611

RESUMEN

The switching variability caused by intrinsic stochasticity of the ionic/atomic motions during the conductive filaments (CFs) formation process largely limits the applications of diffusive memristors (DMs), including artificial neurons, neuromorphic computing and artificial sensory systems. In this study, a DM device with improved device uniformity based on well-crystallized two-dimensional (2D) h-BN, which can restrict the CFs formation from three to two dimensions due to the high migration barrier of Ag+ between h-BN interlayer, is developed. The BN-DM has potential arrayable feature with high device yield of 88%, which can be applied for building a reservoir computing system for digital pattern recognition with high accuracy rate of 96%, and used as an artificial nociceptor to sense the external noxious stimuli and mimic the important biological nociceptor properties. By connecting the BN-DM to a self-made triboelectric nanogenerator (TENG), a self-power mechano-nociceptor system, which can successfully mimic the important nociceptor features of "threshold", "relaxation" and "allodynia" is designed.


Asunto(s)
Nociceptores , Citoesqueleto , Conductividad Eléctrica , Humanos , Neuronas
6.
Opt Express ; 30(23): 42541-42552, 2022 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-36366706

RESUMEN

Longwave infrared spectral imaging (LWIR-SI) has potential in many important civilian and military fields. However, conventional LWIR-SI systems based on traditional dispersion elements always suffer the problems of high cost, large volume and complicated system structure. Micro-electro-mechanical systems Fabry-Perot filtering chips (MEMS-FPFC) give a feasible way for realizing miniaturized, low cost and customizable LWIR-SI systems. The LWIR MEMS-FPFC ever reported can't meet the demands of the next-generation LWIR-SI systems, due to the limitation of small aperture size and nonlinear actuation. In this work, we propose a large-aperture, widely and linearly tunable electromagnetically actuated MEMS-FPFC for LWIR-SI. A multi-field coupling simulation model is built and the wafer-scale bulk-micromachining process is applied to realize the design and fabrication of the proposed MEMS-FPFC. Finally, with the rational structural design and fabrication process, the filtering chip after packaging has an aperture size of 10 mm, which is the largest aperture size of LWIR MEMS-FPFC ever reported. The fabricated electromagnetically actuated MEMS-FPFC can be tuned continuously across the entire LWIR range of 8.39-12.95 µm under ±100 mA driving current with a pretty good linear response of better than 98%. The developed electromagnetically actuated MEMS-FPFC can be directly used for constructing miniaturized LWIR-SI systems, aiming for such applications as military surveillance, gas sensing, and industry monitoring.

7.
J Xray Sci Technol ; 30(1): 1-12, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34719471

RESUMEN

High-energy, high-dose, microfocus X-ray computed tomography (HHM CT) is one of the most effective methods for high-resolution X-ray radiography inspection of high-density samples with fine structures. Minimizing the effective focal spot size of the X-ray source can significantly improve the spatial resolution and the quality of the sample images, which is critical and important for the performance of HHM CT. The objective of this study is to present a 9 MeV HHM CT prototype based on a high-average-current photo-injector in which X-rays with about 70µm focal spot size are produced via using tightly focused electron beams with 65/66µm beam size to hit an optimized tungsten target. In digital radiography (DR) experiment using this HHM CT, clear imaging of a standard 0.1 mm lead DR resolution phantom reveals a resolution of 6 lp/mm (line pairs per mm), while a 5 lp/mm resolution is obtained in CT mode using another resolution phantom made of 10 mm ferrum. Moreover, comparing with the common CT systems, a better turbine blade prototype image was obtained with this HHM CT system, which also indicates the promising application potentials of HHM CT in non-destructive inspection or testing for high-density fine-structure samples.


Asunto(s)
Intensificación de Imagen Radiográfica , Tomografía Computarizada por Rayos X , Fantasmas de Imagen , Tomografía Computarizada por Rayos X/métodos , Rayos X
8.
J Neurosci ; 40(5): 1120-1132, 2020 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-31826945

RESUMEN

When moving around in the world, the human visual system uses both motion and form information to estimate the direction of self-motion (i.e., heading). However, little is known about cortical areas in charge of this task. This brain-imaging study addressed this question by using visual stimuli consisting of randomly distributed dot pairs oriented toward a locus on a screen (the form-defined focus of expansion [FoE]) but moved away from a different locus (the motion-defined FoE) to simulate observer translation. We first fixed the motion-defined FoE location and shifted the form-defined FoE location. We then made the locations of the motion- and the form-defined FoEs either congruent (at the same location in the display) or incongruent (on the opposite sides of the display). The motion- or the form-defined FoE shift was the same in the two types of stimuli, but the perceived heading direction shifted for the congruent, but not for the incongruent stimuli. Participants (both sexes) made a task-irrelevant (contrast discrimination) judgment during scanning. Searchlight and ROI-based multivoxel pattern analysis revealed that early visual areas V1, V2, and V3 responded to either the motion- or the form-defined FoE shift. After V3, only the dorsal areas V3a and V3B/KO responded to such shifts. Furthermore, area V3B/KO shows a significantly higher decoding accuracy for the congruent than the incongruent stimuli. Our results provide direct evidence showing that area V3B/KO does not simply respond to motion and form cues but integrates these two cues for the perception of heading.SIGNIFICANCE STATEMENT Human survival relies on accurate perception of self-motion. The visual system uses both motion (optic flow) and form cues for the perception of the direction of self-motion (heading). Although human brain areas for processing optic flow and form structure are well identified, the areas responsible for integrating these two cues for the perception of self-motion remain unknown. We conducted fMRI experiments and used multivoxel pattern analysis technique to find human brain areas that can decode the shift in heading specified by each cue alone and the two cues combined. We found that motion and form cues are first processed in the early visual areas and then are likely integrated in the higher dorsal area V3B/KO for the final estimation of heading.


Asunto(s)
Percepción de Forma/fisiología , Percepción de Movimiento/fisiología , Corteza Visual/fisiología , Encéfalo/fisiología , Señales (Psicología) , Femenino , Humanos , Masculino , Flujo Optico/fisiología , Estimulación Luminosa
9.
Small ; 17(41): e2103175, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34528382

RESUMEN

The mimicking of both homosynaptic and heterosynaptic plasticity using a high-performance synaptic device is important for developing human-brain-like neuromorphic computing systems to overcome the ever-increasing challenges caused by the conventional von Neumann architecture. However, the commonly used synaptic devices (e.g., memristors and transistors) require an extra modulate terminal to mimic heterosynaptic plasticity, and their capability of synaptic plasticity simulation is limited by the low weight adjustability. In this study, a WSe2 -based memtransistor for mimicking both homosynaptic and heterosynaptic plasticity is fabricated. By applying spikes on either the drain or gate terminal, the memtransistor can mimic common homosynaptic plasticity, including spiking rate dependent plasticity, paired pulse facilitation/depression, synaptic potentiation/depression, and filtering. Benefitting from the multi-terminal input and high adjustability, the resistance state number and linearity of the memtransistor can be improved by optimizing the conditions of the two inputs. Moreover, the device can successfully mimic heterosynaptic plasticity without introducing an extra terminal and can simultaneously offer versatile reconfigurability of excitatory and inhibitory plasticity. These highly adjustable and reconfigurable characteristics offer memtransistors more freedom of choice for tuning synaptic weight, optimizing circuit design, and building artificial neuromorphic computing systems.


Asunto(s)
Plasticidad Neuronal , Sinapsis , Humanos
10.
J Community Psychol ; 49(7): 2454-2471, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-33667325

RESUMEN

Against the background of fast-paced aging and urbanization in China, the current study proposed a "Residential environment-Emotional health-Life satisfaction" framework to investigate the associations among perceived residential environment quality (PREQ), positive affect (PA), social trust (ST), and life satisfaction (LS) of old adults. Data used were from a nationwide survey and covered 3825 people aged 60 years or older living in urban communities. The partial least squares-structural equation modeling approach was adopted to verify hypotheses. The results found that (1) PREQ, PA, and ST were positively correlated with LS; (2) ST mediated the relationship between PREQ and LS; and (3) people who are men, living without children, high environmental perception, and with a workout habit were more sensitively to PREQ. These findings indicate that improving the residential environment helps to promote the mental health of the Chinese urban elderly, which may have some implications for establishing an age-friendly community.


Asunto(s)
Satisfacción Personal , Medio Social , Adulto , Anciano , Niño , China , Ambiente , Humanos , Masculino , Salud Mental
12.
Appl Opt ; 53(23): 5205-10, 2014 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-25320930

RESUMEN

An optical imaging signal is vulnerable to undesired features such as ambient light illumination and partial specular reflection from the target; the success of extracting target features from images depends largely on appropriate design of illumination. This paper presents an approach for self-adaptive illumination for optical imaging systems. The proposed illumination system projects a reference image to a target surface as an initial structured illumination, and then adjusts the projected image automatically to compensate the negative influences of undesired features. After this self-adaptive control process, undesired features would appear mostly invisible in the captured images. The signal-to-noise ratio would be improved dramatically well before subsequent image processing. In the validation experiments, several images with uniform brightness were offered as reference images; the captured images could achieve high brightness uniformity, even when the target surface was uneven or was illuminated by ambient light. In a further experiment of selective vessel illumination on a human palm, simulated vessel regions were selectively illuminated. Undesired features, like palm prints, almost disappeared in the images captured.

13.
Chem Soc Rev ; 42(24): 9304-32, 2013 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-24045837

RESUMEN

In the midst of the global climate change phenomenon, mainly caused by fossil fuel burning to provide energy for our daily life and discharge of CO2 into the atmosphere, biogas is one of the important renewable energy sources that can be upgraded and applied as a fuel source for energy in daily life. The advantages of the production of hybrid materials, metal-organic framework (MOF) adsorbents, expected for the biogas upgrading, rely on the bulk separation of CO2 under near-ambient conditions. This review highlights the challenges for MOF adsorbents, which have the greatest upgrading abilities for biogas via selective passage of methane. The key factors improving the ideal MOF materials for these high CO2 capture and selectivity uses for biogas upgrading to produce bio-methane and reduce fossil-fuel CO2 emission will be discussed.


Asunto(s)
Biocombustibles/análisis , Dióxido de Carbono/aislamiento & purificación , Compuestos Organometálicos/química , Adsorción , Diseño de Equipo , Metano/análisis , Modelos Moleculares
14.
Zhonghua Yi Xue Za Zhi ; 94(39): 3098-101, 2014 Oct 28.
Artículo en Zh | MEDLINE | ID: mdl-25549688

RESUMEN

OBJECTIVE: To explore the relationship between bore diameter of porous hydroxyapatite (HA) scaffolds and the adhesion, proliferation and metabolism of osteoblasts by 3D cultivation. METHODS: MC3T3-E1 cell suspension was separately dropped axially through different bore diameter scaffolds (Group A:150 µm, Group B:300 µm) to confirm initial seeding. Then scaffolds were transferred into a perfusion bioreactor of 5% CO2 at 37°C for 5 days with an average flow of 3.4 ml/min. After perfusion cultivation, cell proliferation between different groups of scaffolds was determined by methyl thiazolyl tetrazolium (MTT) assay and cell metabolic activities were determined by glucose consumption. Lastly cell adhesion and proliferation were observed directly by scanning electronic microscope (SEM). RESULTS: The results of MTT assay showed that the optical density/mass ratios were 1.31 ± 0.26 in group A and 1.51 ± 0.43 in group B. There was no significant difference (t test, P = 0.36). Glucose consumption in group A was significantly lower than that in group B [(162.38 ± 33.09) vs (217.97 ± 27.91) µmol/L, P = 0.01]. The adhesion, proliferation, pseudopodia and extracellular matrix of osteoblasts in internal part of scaffolds after perfusion cultivation were observed by SEM. CONCLUSION: With excellent biocompatibility, porous HA scaffolds are available for fabricating tissue engineering bones. There is no effect of bore diameter on the proliferation of osteoblasts. But it affects the metabolic activity of osteoblasts. So bore diameter may be increased within a feasible range on the premise of mechanical properties.


Asunto(s)
Técnicas de Cultivo de Célula , Osteoblastos , Andamios del Tejido , Animales , Reactores Biológicos , Adhesión Celular , Línea Celular , Proliferación Celular , Durapatita , Ratones , Porosidad , Ingeniería de Tejidos
15.
Microsyst Nanoeng ; 10: 63, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38770033

RESUMEN

As one of the most common spatial light modulators, linear micromirror arrays (MMAs) based on microelectromechanical system (MEMS) processes are currently utilized in many fields. However, two crucial challenges exist in the fabrication of such devices: the adhesion of silicon microstructures caused by anodic bonding and the destruction of the suspended silicon film due to residual stress. To solve these issues, an innovative processing method assisted by temporary anchors is presented. This approach effectively reduces the span of silicon microstructures and improves the Euler buckling limit of the silicon film. Importantly, these temporary anchors are strategically placed within the primary etching areas, enabling easy removal without additional processing steps. As a result, we successfully achieved wafer-level, high-yield manufacturing of linear MMAs with a filling factor as high as 95.1%. Demonstrating superior capabilities to those of original MMAs, our enhanced version boasts a total of 60 linear micromirror elements, each featuring a length-to-width ratio of 52.6, and the entire optical aperture measures 5 mm × 6 mm. The linear MMA exhibits an optical deflection angle of 20.4° at 110 Vdc while maintaining exceptional deflection flatness and uniformity. This study offers a viable approach for the design and fabrication of thin-film MEMS devices with high yields, and the proposed MMA is promising as a replacement for digital micromirror devices (DMDs, by TI Corp.) in fields such as spectral imaging and optical communication.

16.
Mater Horiz ; 11(4): 939-948, 2024 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-38078356

RESUMEN

Being capable of processing large amounts of redundant data and decreasing power consumption, in-sensor computing approaches play significant roles in neuromorphic computing and are attracting increasing interest in perceptual information processing. Herein, we proposed a high performance humidity-sensitive memristor based on a Ti/graphene oxide (GO)/HfOx/Pt structure and verified its potential for application in remote health management and contactless human-machine interfaces. Since GO possesses abundant hydrophilic groups (carbonyl, epoxide, and hydroxyl), the memristor shows a high humidity sensitivity, fast response, and wide response range. By utilizing the proton-modulated redox reaction, humidity exposure to the memristor induces a dynamic change in the switching between high and low resistance states, ensuring essential synaptic learning functions, such as paired-pulse facilitation, spike number-dependent plasticity, and spike amplitude-dependent plasticity. More importantly, based on the humidity-induced salient features originating from the abundant hydrophilic functional groups in GO, we have implemented a noncontact human-machine interface utilizing the respiratory mode in humans, demonstrating the potential of promoting health monitoring applications and effectively blocking virus transmission. In addition, the high recognition accuracy of contactless handwriting in a 5 × 5 array artificial neural network was successfully achieved, which is attributed to the excellent emulated synaptic behaviors. This study provides a feasible method to develop an excellent humidity-sensitive memristor for constructing efficient in-sensor computing for application in health management and contactless human-computer interaction.


Asunto(s)
Cognición , Computadores , Grafito , Humanos , Humedad , Compuestos Epoxi
17.
Seizure ; 115: 28-35, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38183825

RESUMEN

BACKGROUND: We aimed to explore the prevalence of autoimmune antibodies (Abs) in a large consecutive series with "chronic" epilepsy and without symptoms of autoimmune encephalitis; and to compare the immunopathology of brain tissue from drug-resistant epilepsy (DRE) with and without Abs positivity. METHODS: Neuronal and glial antibodies were detected in the serum of patients who were admitted to the wards of West China Hospital from October 2016 to September 2019 and had epilepsy by cell-based assays and tissue-based assays. RESULTS: Twenty-one (6.8 %) of 328 patients had positive Ab findings for the following: dipeptidyl-peptidase-like protein-6 (n = 7), contactin-associated protein-like 2 (n = 5), glutamic acid decarboxylase 65 (n = 4), gamma aminobutyric acid beta receptor (n = 2), N-methyl-d-aspartate receptor (n = 2), and dopamine D2 receptor (n = 1). Antibodies were detected in 6.9 % (13/187) of epilepsy people with unknown etiology and 5.6 % (8/141) of patients with known etiology, respectively. Among 190 patients with DRE, 14 (7.3 %) patients were Abs-positive. There was no significant difference between individuals with seropositive and seronegative results in clinical manifestations, except that the history of febrile seizure was significantly more frequent in the seropositive group. Moreover, brain samples from 3 patients with Abs-positive DRE (with DPPX in 2 patients, and CASPR2 in 1 patient) and 18 patients with Abs-negative DRE were analyzed for immunopathology. We found higher expression of CD8-positive T-cells in the hippocampus of Abs-positive DRE group. CONCLUSIONS: Neuronal antibodies are potentially involved in the process of "chronic" epilepsy, and CD8-positive T-cells may play an important role in this process.


Asunto(s)
Epilepsia Refractaria , Encefalitis , Epilepsia , Humanos , Autoanticuerpos , Prevalencia , Epilepsia/diagnóstico , Encéfalo/patología , Epilepsia Refractaria/patología
18.
Rev Sci Instrum ; 95(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38477651

RESUMEN

Ultra-narrow pulses serve as critical components in numerous applications. These pulses have ultra-fast leading edges that typically function as precision trigger signals to synchronize various instruments. Ultra-narrow pulses inherently exhibit an ultra-wide bandwidth, gaining significant attention in diverse electronic systems encompassing communications, radar imaging, electronic warfare, and others. Although several techniques have been explored for generating ultra-narrow pulses, field programmable gate arrays (FPGAs) offer a promising alternative in terms of flexibility and integration. This study introduces a scalable delay pulse synchronizer method with a resolution of 23 ps. A programmable, successive, narrow pulse sequence operating at a 1-GHz repetition frequency is implemented within a monolithic FPGA. The performance of the proposed method is evaluated using an existing board with a general commercial FPGA in the laboratory. This new method presents a convenient and efficient approach of achieving ultra-narrow pulse synchronization, being applicable across various fields.

19.
J Cross Cult Gerontol ; 28(1): 49-63, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23397227

RESUMEN

It is often assumed that Chinese people tend to have a more positive attitude toward aging and old age than Americans, due to the cultural generalization of collectivism versus individualism. This study aimed to critically examine this assumption by using first-hand empirical data collected in a Chinese and an American university (standardized surveys and in-depth focus group interviews). Respectively, 980 college students in China and 332 college students in the U.S. were recruited for the standardized surveys; whereas two focus-group interviews in each country (4 participants per group) were conducted to collect more in-depth information. Contrary to the common assumption, this study revealed that Chinese students actually hold more negative attitudes toward aging and older people compared to their American peers. It was also found that females tend to hold more positive attitudes than male students across both cultures, though American female students hold more positive attitudes than Chinese female students. Chinese students' interactions with seniors are often limited to their grandparents whereas American students tend to reach out to non-grandparent seniors in larger communities. Chinese students' more negative attitudes toward aging and older people may be a result of a combination of educational, social, and economic factors-a higher level of age segregation (geographically, socially, and intellectually) and a lack of gerontological curriculum in Chinese educational system, the caregiving burden faced by the one-child generation compounded with lack of governmental support for caregiving, as well as the rising youth-oriented consumerist culture.


Asunto(s)
Ageísmo/etnología , Envejecimiento/etnología , Actitud/etnología , Estudiantes/psicología , Universidades , Anciano , Ageísmo/psicología , Envejecimiento/psicología , Pueblo Asiatico/psicología , China , Comparación Transcultural , Femenino , Grupos Focales , Humanos , Relaciones Intergeneracionales/etnología , Entrevistas como Asunto , Investigación Cualitativa , Factores Sexuales , Estudiantes/estadística & datos numéricos , Encuestas y Cuestionarios , Estados Unidos , Adulto Joven
20.
PLoS One ; 18(12): e0295807, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38096147

RESUMEN

In the application of driverless technology, current traffic sign recognition methods are susceptible to the influence of ambient light interference, target size changes and complex backgrounds, resulting in reduced recognition accuracy. To address these challenges, this study introduces an optimisation algorithm called ETSR-YOLO, which is based on the YOLOv5s algorithm. First, this study improves the path aggregation network (PANet) of YOLOv5s to enhance multi-scale feature fusion by generating an additional high-resolution feature layer to improve the recognition of YOLOv5s for small-sized objects. Second, the study introduces two improved C3 modules that aim to suppress background noise interference and enhance the feature extraction capabilities of the network. Finally, the study uses the Wise-IoU (WIoU) function in the post-processing stage to improve the learning ability and robustness of the algorithm to different samples. The experimental results show that ETSR-YOLO improves mAP@0.5 by 6.6% on the Tsinghua-Tencent 100K (TT100K) dataset and by 1.9% on the CSUST Chinese Traffic Sign Detection Benchmark 2021 (CCTSDB2021) dataset. In the experiments conducted on the embedded computing platform, ETSR-YOLO demonstrates a short average inference time, thereby affirming its capability to deliver dependable traffic sign detection for intelligent vehicles operating in real-world traffic scenes. The source code and test results of the models used in this study are available at https://github.com/cbrook16/ETSR-YOLO.

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