Integrated Design and Evaluation System for the Effect of Rest Breaks in Sustained Mental Work Based on Neuro-physiological Signals

Lanlan Chen,Junzhong Zou,Takenao Sugi,Masatoshi Nakamura,Shuichiro Shirakawa 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.4

Rest breaks are very important to prevent the accumulation of mental fatigue in sustained mental work environments. In this research, an integrated design and evaluation system for fatigue and relaxation is proposed, which consists of subjective scale, performance assessment and neurological signals. A work-rest schedule containing mental calculation and rest break is designed to reflect effect of prolonged cognitive work and rest time in mental work environments. Inter-individual difference has been taken into account to extract common features. The results indicate that rest breaks in sus-tained mental work are effective to counteract mental fatigue and improve work efficiency. Rest breaks are widely recommended in practical mental work circumstance. Integrated analysis from multi-estimators is helpful to improve the validity and explore the underlying mechanisms central to mental fatigue. Electroencephalogram (EEG) signals at occipital region show high correlation with performance. Thus EEG signals can contribute to the efficient design of work-rest schedule.

The Balanced Method of Magnetic Torque Under Wind Load for HVDC Inspection Robot

Xianjin Xu,Yuhang Yang,Haoda Chen,Lanlan Liu,Yu Yan 한국자기학회 2021 Journal of Magnetics Vol.26 No.1

Influence of Glass-Lined V-Shaped Stirrers on Crystallization Properties

Fu Shuangcheng,Zhao Tianyi,Tao Lanlan,Chen Guofeng,Yang Dong,Tao Liang 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.6

In the crystallization process, the quality of crystal formation is signifi cantly aff ected by the stirring mechanism. Typically, the effi ciency of mixing is directly correlated with the rotational speed of the stirrer. Nevertheless, elevated stirring speeds can lead to the fragmentation of crystal nuclei, thereby exerting a detrimental infl uence on the overall crystallization quality. To address such issue, a glass-lined V-shaped stirrer with a better stirring eff ect under low-speed conditions was developed in the present study. Particular attention was paid to providing a better stirring eff ect under low-speed conditions. The computational fl uid dynamics (CFD) numerical simulation method was employed to conduct a comparative analysis of the fl ow fi eld distribution when subjected to the infl uence of a V-shaped stirrer in comparison with two frequently employed stirrers. The velocity fi eld, turbulence intensity, particle distribution and heat transfer rate were analyzed, and experimental measurements of the mixing time were conducted. The fi ndings from the present study reveal that when the stirring paddle was operated at a speed of 80 rpm, the V-shaped stirrer exhibited a larger circulation range compared with the other two stirrers. Further, the overall turbulence intensity in the fl ow fi eld was higher, ensuring a more homogeneous distribution of crystal nuclei. Additionally, the heat transfer rate was found to be signifi cantly faster, contributing to improved crystallization effi ciency and higher-quality crystallization products. The utilization of the glass-lined V-shaped stirrer off ers the advantage of improved mixing effi ciency in the crystallization process, while maintaining the crystal quality. This innovation has the potential to bring about a transformative shift in manufacturing processes and contribute to advancements in the fi eld of crystallization.

Effect of Laser Power on Hybrid Laser-Gas Metal Arc Welding (GMAW) of a 6061 Aluminum Alloy

Zhou Huiling,Fu Fanglian,Dai Zhixin,Qiao Yanxin,Chen Jian,Yang Lanlan,Liu Wen 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.11

The effect of laser power on the geometrical characteristics, microstructure and micro-hardness of the welding joints for 6061 aluminum alloy after hybrid laser-gas metal arc welding (GMAW) was investigated. The results showed that the welding joints from "Bottom" to "Top" were mainly composed of planar crystals, columnar crystals, and equiaxed dendrites. With increasing laser power, the weld depth and width and the grain size increased. When the laser power reached 5 kW, pores could be found in the weld pool region. Micro-hardness measurements showed that the application of higher laser power hardly changed the hardness of the welding joint.

Expression profile and estrogenic regulation of Amh during gonadal sex differentiation in northern snakehead (Channa argus)

Qing Luo,Mi Ou,Jian Zhao,Haiyang Liu,Dandan Gao,Yanduo Wu,Lanlan Zhang,Kunci Chen 한국유전학회 2020 Genes & Genomics Vol.42 No.7

Background Anti-Müllerian hormone (Amh) plays a critical role in both early sex determination and later gonad development in vertebrate species. However, it remains unknown in northern snakehead (Channa argus), which is economically important freshwater fish with sexual dimorphism. Objective This study aimed to identify the expression profiles and estrogenic regulation of CaAmh during gonadal sex differentiation in C. argus. Methods The cDNA and genomic DNA sequences of CaAmh were identified by PCR and RACE techniques. The expression patterns of CaAmh were detected by qRT-PCR during the gonadal sex differentiation and after 17α-ethinyloestradiol (EE2) treatments. Results CaAmh is composed of seven exons and six introns, and its full-length cDNA is 2413 bp in length, with 1635 bp open reading frame (ORF) that encodes a 544 amino acid protein. Tissues expression patterns revealed that CaAmh display the highest expression in testis of XY males (40.36 folds, p < 0.01). The spatio-temporal expression patterns during gonadal sex differentiation indicated that CaAmh expression differed between XX females and XY males at 30 day after hatching (dah), and reached to the peak (36.03 folds, p < 0.01) at 90 dah in XY gonads. However, CaAmh expression in XX gonads remained low throughout the sampling period. Furthermore, CaAmh expression in the gonads (ovaries) of the sex-reversed XY fish (XY-F) by the administration of estrogen EE2 was downregulated to low level, similar to that in ovaries of normal XX females (XX-F). Conclusions These results show that Amh plays a critical role in testicular differentiation of C. argus and it is apparently modulated by estrogens in this species.

Candesartan-graft-polyethyleneimine Cationic Micelles for Effective Co-delivery of Drug and Gene in Anti-angiogenic Lung Cancer Therapy

Shanhu Hao,Ying Yan,Xue Ren,Ying Xu,Lanlan Chen,Haibo Zhang 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.3

A multifunctional polymer-drug conjugate candesartan-graft-polyethyleneimine (CD-PEI, CP) containing low molecular weight polyethyleneimine (PEI) and candesartan (CD) conjugated via an amide bond was fabricated as a co-delivery micelle of drug and siRNA for potential lung cancer therapy. Here, CD as an angiotensin II type 1 receptor blocker rich in imidazole and tetrazole rings was utilized to strengthen endosomal buffering capacity of CP and suppress tumor angiogenesis. The selfassembled CP/siRNA complexes exhibited desirable and homogenous particle size, moderate positive charges, and efficient release of drug and siRNA in vitro. In addition, CD and siRNA could readily detached from nanovectors in tumor cells via an amidase-responsive mechanism and they achieved synergistic anti-angiogenesis efficacy by effectively downregulating the expression of vascular endothelial growth factor (VEGF) mRNA and protein via different pathways in vitro. In vivo investigation on nude mice bearing A549 tumor xenografts revealed that CP/siRNA complexes possessed strong antitumor activity. These findings suggested that CP could be an ideal nanovector for simultaneous transfer of drug and siRNA, and a multifunctional CP/siRNA co-delivery system with enhanced endosomal buffering capacity, amidase-responsive drug release and synergistic anti-angiogenesis efficacy might be a new promising strategy for effective lung cancer therapy.

Early CT Findings of Coronavirus Disease 2019 (COVID-19) in Asymptomatic Children: A Single-Center Experience

Lan Lan,Xu Dan,Xia Chen,Wang Shaokang,Yu Minhua,Xu Haibo 대한영상의학회 2020 Korean Journal of Radiology Vol.21 No.7

Objective: The current study reported a case series to illustrate the early computed tomography (CT) findings of coronavirus disease 2019 (COVID-19) in pediatric patients. Materials and Methods: All pediatric patients who were diagnosed with COVID-19 and who underwent CT scan in Zhongnan Hospital of Wuhan University from January 20, 2020 to February 28, 2020 were included in the current study. Data on clinical and CT features were collected and analyzed. Results: Four children were included in the current study. All of them were asymptomatic throughout the disease course (ranging from 7 days to 15 days), and none of them showed abnormalities in blood cell counts. Familial cluster was the main transmission pattern. Thin-section CT revealed abnormalities in three patients, and one patient did not present with any abnormal CT findings. Unilateral lung involvement was observed in two patients, and one patient showed bilateral lung involvement. In total, five small lesions were identified, including ground-glass opacity (n = 4) and consolidation (n = 1). All lesions had ill-defined margins with peripheral distribution and predilection of lower lobe. Conclusion: Small patches of ground-glass opacity with subpleural distribution and unilateral lung involvement were common findings on CT scans of pediatric patients in the early stage of the disease.