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1.
Adv Sci (Weinh) ; 11(33): e2403150, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38952052

RESUMO

Traditional artificial vision systems built using separate sensing, computing, and storage units have problems with high power consumption and latency caused by frequent data transmission between functional units. An effective approach is to transfer some memory and computing tasks to the sensor, enabling the simultaneous perception-storage-processing of light signals. Here, an optical-electrical coordinately modulated memristor is proposed, which controls the conductivity by means of polarization of the 2D ferroelectric Ruddlesden-Popper perovskite film at room temperature. The residual polarization shows no significant decay after 109-cycle polarization reversals, indicating that the device has high durability. By adjusting the pulse parameters, the device can simulate the bio-synaptic long/short-term plasticity, which enables the control of conductivity with a high linearity of ≈0.997. Based on the device, a two-layer feedforward neural network is built to recognize handwritten digits, and the recognition accuracy is as high as 97.150%. Meanwhile, building optical-electrical reserve pool system can improve 14.550% for face recognition accuracy, further demonstrating its potential for the field of neural morphological visual systems, with high density and low energy loss.

2.
ACS Appl Mater Interfaces ; 15(42): 49390-49401, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37815786

RESUMO

Memristor synapses based on green and pollution-free organic materials are expected to facilitate biorealistic neuromorphic computing and to be an important step toward the next generation of green electronics. Metalloporphyrin is an organic compound that widely exists in nature with good biocompatibility and stable chemical properties, and has already been used to fabricate memristors. However, the application of metalloporphyrin-based memristors as synaptic devices still faces challenges, such as realizing a high switching ratio, low power consumption, and bidirectional conductance modulation. We developed a memristor that improves the resistive switching (RS) characteristics of Zn(II)meso-tetra(4-carboxyphenyl) porphine (ZnTCPP) by combining it with deoxyribonucleic acid (DNA) in a composite film. The as-fabricated ZnTCPP-DNA-based device showed excellent RS memory characteristics with a sufficiently high switching ratio of up to ∼104, super low power consumption of ∼39.56 nW, good cycling stability, and data retention capability. Moreover, bidirectional conductance modulation of the ZnTCPP-DNA-based device can be controlled by modulating the amplitudes, durations, and intervals of positive and negative pulses. The ZnTCPP-DNA-based device was used to successfully simulate a series of synaptic functions including long-term potentiation, long-term depression, spike time-dependent plasticity, paired-pulse facilitation, excitatory postsynaptic current, and human learning behavior, which demonstrates its potential applicability to neuromorphic devices. A two-layer artificial neural network was used to demonstrate the digit recognition ability of the ZnTCPP-DNA-based device, which reached 97.22% after 100 training iterations. These results create a new avenue for the research and development of green electronics and have major implications for green low-power neuromorphic computing in the future.


Assuntos
Metaloporfirinas , Humanos , Eletrônica , Poluição Ambiental , DNA
3.
ACS Nano ; 17(21): 21518-21530, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37897737

RESUMO

Neuromorphic computing based on memristors capable of in-memory computing is promising to break the energy and efficiency bottleneck of well-known von Neumann architectures. However, unstable and nonlinear conductance updates compromise the recognition accuracy and block the integration of neural network hardware. To this end, we present a highly stable memristor with self-assembled vertically aligned nanocomposite (VAN) SrTiO3:MgO films that achieve excellent resistive switching with low set/reset voltage variability (4.7%/-5.6%) and highly linear conductivity variation (nonlinearity = 0.34) by spatially limiting the conductive channels at the vertical interfaces. Various synaptic behaviors are simulated by continuously modulating the conductance. Especially, convolutional image processing using diverse crossbar kernels is demonstrated, and the artificial neural network achieves an overwhelming recognition accuracy of up to 97.50% for handwritten digits. Even under the perturbation of Poisson noise (λ = 10), 6% Salt and Pepper noise, and 5% Gaussian noise, the high recognition accuracies are retained at 95.43%, 94.56%, and 95.97%, respectively. Importantly, the logic memory function is proven experimentally based on the nonvolatile properties. This work provides a material system and design idea to achieve high-performance neuromorphic computing and logic operation.

4.
J Appl Psychol ; 107(12): 2285-2305, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35324221

RESUMO

As the diversity field evolves, scholars are shifting the attention from mitigating "problems" associated with diversity to searching for ways to leverage the potential value in diversity. We advance this field by studying how an inclusive climate benefits organizational innovation, an important foundation for sustained competitive advantage. Adopting a synergy perspective, we examine the internal (i.e., workplace demographic diversity in terms of age, gender, and region) and external contingencies (i.e., environmental scanning and environmental uncertainty) for an inclusive climate to foster incremental and radical innovation through the mechanism of knowledge management capacity. We tested our research model with a three-wave data collection from multiple sources (i.e., employees, human resource managers, and executives) in 102 organizations. We found that workplace age and regional diversity (but not gender diversity) strengthened the positive effect of inclusive climate on knowledge management capacity, and subsequently incremental and radical innovation. The facilitating effect of environmental scanning was only significant for organizations that experienced higher environmental uncertainty. Our research highlights the importance of considering the synergistic potential of internal human resources and external environments for organizations to capitalize on their inclusive climate for knowledge management and innovation. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Gestão do Conhecimento , Local de Trabalho , Humanos , Inovação Organizacional , Organizações , Criatividade , Cultura Organizacional
5.
J Appl Psychol ; 106(3): 317-329, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33871269

RESUMO

The current study aims to understand the detrimental effects of COVID-19 pandemic on employee job insecurity and its downstream outcomes, as well as how organizations could help alleviate such harmful effects. Drawing on event system theory and literature on job insecurity, we conceptualize COVID-19 as an event relevant to employees' work, and propose that event strength (i.e., novelty, disruption, and criticality) of COVID-19 influences employee job insecurity, which in turn affects employee work and non-work outcomes. We also identified important organization adaptive practices responding to COVID-19 based on a preliminary interview study, and examined its role in mitigating the undesired effects of COVID-19 event strength. Results from a two-wave lagged survey study indicated that employees' perceived COVID-19 event novelty and disruption (but not criticality) were positively related to their job insecurity, which in turn was positively related to their emotional exhaustion, organizational deviance, and saving behavior. Moreover, organization adaptive practices mitigated the effects of COVID-19 event novelty and criticality (but not disruption) on job insecurity. Theoretical and practical implications are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
COVID-19/psicologia , Emprego/psicologia , Satisfação no Emprego , Saúde Ocupacional , Gestão de Recursos Humanos/métodos , Estresse Psicológico/etiologia , Adulto , COVID-19/prevenção & controle , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Teoria Psicológica , Estresse Psicológico/prevenção & controle
6.
J Appl Psychol ; 106(6): 825-838, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34138589

RESUMO

To protect workers' safety while gradually resuming on-site operations amid the COVID-19 pandemic, many organizations are offering employees the flexibility to decide their work location on a daily basis (i.e., whether to work from home or to work in the office on a particular day). However, little is known about what factors drive employees' daily decisions to work from home versus office during the pandemic. Taking a social ecological perspective, we conceptualize employees' daily choice of work location (home vs. office) as a way to cope with stressors they have encountered on the previous day, and conducted a daily diary study to examine how five categories of work-related and COVID-related stressors during the pandemic (identified through a pilot interview study) may jointly predict employees' next-day work location. We collected data over five workdays from 127 participants working in a Chinese IT company which allowed employees to choose their work location on a daily basis amid the pandemic. We found that experiencing more work-family boundary stressors and work coordination stressors on a certain day were associated with a greater likelihood of working in the office (vs. at home) on the next day, while experiencing more workload stressors prompted employees to work at home (vs. in the office) on the next day. Furthermore, we found that COVID-19 infection-related stressors moderated the effects of technology stressors and workload stressors on next-day work location. Our research findings offer implications for understanding the driving factors of daily work location choices during and beyond the pandemic. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
COVID-19/psicologia , Estresse Ocupacional/psicologia , Teletrabalho/estatística & dados numéricos , Local de Trabalho/psicologia , Adulto , COVID-19/prevenção & controle , Feminino , Humanos , Masculino , Pandemias , SARS-CoV-2
7.
Clin Chim Acta ; 519: 101-110, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33887264

RESUMO

Vascular calcification (VC), which is closely associated with significant mortality in cardiovascular disease, chronic kidney disease (CKD), and/or diabetes mellitus, is characterized by abnormal deposits of hydroxyapatite minerals in the arterial wall. The impact of oxidative stress (OS) on the onset and progression of VC has not been well described. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases, xanthine oxidases, myeloperoxidase (MPO), nitric oxide synthases (NOSs), superoxide dismutase (SOD) and paraoxonases (PONs) are relevant factors that influence the production of reactive oxygen species (ROS). Furthermore, excess ROS-induced OS has emerged as a critical mediator promoting VC through several mechanisms, including phosphate balance, differentiation of vascular smooth muscle cells (VSMCs), inflammation, DNA damage, and extracellular matrix remodeling. Because OS is a significant regulator of VC, antioxidants may be considered as novel treatment options.


Assuntos
Músculo Liso Vascular , Calcificação Vascular , Humanos , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso , NADPH Oxidases , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Calcificação Vascular/metabolismo
8.
J Appl Psychol ; 106(8): 1103-1117, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34423997

RESUMO

Employers have increasingly turned to virtual interviews to facilitate online, socially distanced selection processes in the face of the COVID-19 pandemic. However, there is little understanding about the experience of job candidates in these virtual interview contexts. We draw from Event System Theory (Morgeson et al., 2015) to advance and test a conceptual model that focuses on a high-stress, high-stakes setting and integrates literatures on workplace stress with literatures on applicant reactions. We predict that when applicants ruminate about COVID-19 during an interview and have higher levels of COVID-19 exhaustion, they will have higher levels of anxiety during virtual interviews, which in turn relates to reduced interview performance, lower perceptions of fairness, and reduced intentions to recommend the organization. Further, we predict that three factors capturing COVID-19 as an enduring and impactful event (COVID-19 duration, COVID-19 cases, COVID-19 deaths) will be positively related to COVID-19 exhaustion. We tested our propositions with 8,343 job applicants across 373 companies and 93 countries/regions. Consistent with predictions, we found a positive relationship between COVID-19 rumination and interview anxiety, and this relationship was stronger for applicants who experienced higher (vs. lower) levels of COVID-19 exhaustion. In turn, interview anxiety was negatively related to interview performance, fairness perceptions, and recommendation intentions. Moreover, using a relevant subset of the data (n = 6,136), we found that COVID-19 duration and deaths were positively related to COVID-19 exhaustion. This research offers several insights for understanding the virtual interview experience embedded in the pandemic and advances the literature on applicant reactions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Ansiedade , COVID-19 , Emprego/psicologia , Entrevistas como Assunto , Adulto , Aspirações Psicológicas , COVID-19/epidemiologia , Feminino , Humanos , Masculino , Pandemias
9.
Clin Chim Acta ; 516: 15-26, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33476587

RESUMO

Adipose tissue (AT), a critical endocrine gland, is capable of producing and secreting abundant adipokines. Adipokines act on distant or adjacent organ tissues via paracrine, autocrine, and endocrine mechanism, which play attractive roles in the regulation of glycolipid metabolism and inflammatory response. Increasing evidence shows that adipokines can connect obesity with cardiovascular diseases by serving as promoters or inhibitors in vascular calcification. The chronic hypoxia in AT, caused by the adipocyte hypertrophy, is able to trigger imbalanced adipokine generation, which leads to apoptosis, osteogenic differentiation of vascular smooth muscle cells (VSMCs), vascular inflammation, and abnormal deposition of calcium and phosphorus in the vessel wall. The objectives of this review aim at providing a brief summary of the crucial influence of major adipokines on the formation and development of vascular calcification, which may contribute to better understanding these adipokines for establishing the appropriate therapeutic strategies to counteract obesity-associated vascular calcification.


Assuntos
Adipocinas , Calcificação Vascular , Tecido Adiposo , Humanos , Obesidade , Osteogênese
10.
Clin Chim Acta ; 502: 293-304, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31794767

RESUMO

Atherosclerosis is an arterial disease associated with dyslipidemia, abnormal arterial calcification and oxidative stress. It has been shown that a continued chronic inflammatory state of the arterial wall contributes to the development of atherosclerosis. The inflammatory stimulation, recruitment of inflammatory cells and production of pro-inflammatory cytokines enhances vascular inflammation. Some members of the S100 proteins family bind with their receptors, such as advanced glycation end products (RAGE), scavenger receptors (CD36) and toll-like receptor 4 (TLR-4), contributing to the cellular response in atherosclerotic progression. This review summarizes the roles of S100 proteins (S100A8, S100A9 and S100A12) in the vascular inflammation, vascular calcification and vascular oxidative stress. S100 proteins are released from monocytes, smooth muscle cells and endothelial cells in response to cellular stress stimuli, and then the binding of S100 proteins to RAGE activate downstream signaling such as transcription factor kappa B (NF-κB) translocation and reactive oxygen species (ROS) production, which act as a positive feedback loop for inducing pro-inflammatory phenotype in a wide variety of cell types including endothelial cells, vascular smooth muscle cells and leukocytes. Thus, it suggests that the inhibition of S100 proteins-mediated RAGE and TLR4 activation appears to be a promising approach to treat atherosclerosis. In addition, recent study showed that serum S100A12 can predict future cardiovascular events, highlighting that S100A12 is likely to be a potential biomarker of therapeutic efficacy and disease progression in coronary heart disease. Future studies of patients with coronary heart disease may provide more evidences supporting that S100 proteins is promising drug target in the prevention and therapy of atherosclerosis.


Assuntos
Aterosclerose/etiologia , Proteínas S100/fisiologia , Aterosclerose/patologia , Biomarcadores/sangue , Vasos Sanguíneos/patologia , Doença das Coronárias/diagnóstico , Humanos , Inflamação , Estresse Oxidativo , Proteína S100A12/sangue , Calcificação Vascular
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