Construction equipment related accidents, such as collisions between equipment and pedestrian workers, pose a major challenge to occupational safety at construction sites. Decrement of operators' ...hazard detection ability resulting from attention failure is a leading cause of these accidents. Although mental fatigue induced by prolonged and monotonous operating tasks is known as the primary cause of this type of failure, little is revealed on how mental fatigue influences operators' ability to detect hazardous situations and associated visual attention features. To address this issue, this study uses wearable eye-tracking technology to evaluate the impact of mental fatigue on operators' ability in hazard detection and the corresponding patterns of visual attention allocation. Twelve healthy participants performed a simulated excavator operating task in a laboratory experiment. Subjective mental fatigue assessment, hazard detection task performance, and eye movement metrics were recorded and analyzed. In the experiment, mental fatigue was effectively induced and manipulated by a Time-On-Operating (TOO) procedure. Results revealed that operators' hazard detection ability decreased with the increase in subjective mental fatigue level, reflected by significant increases in reaction time for hazards and the number of misdetections. Attention allocation-related data were further analyzed to explain the specific manifestations of hazard detection failure in visual attention. The results indicated that the decrease of operators' hazard detection ability is associated with the changes of the distributions of fixation and gaze point while mental fatigue level increases. Consequently, clear observation of surrounding hazards and related details becomes difficult for operators. The findings demonstrate the effectiveness of wearable eye-tracking technology in measuring and quantifying operators' mental fatigue and hazard detection ability. More importantly, the findings offer insights into the impairing effect of mental fatigue on operators' hazard detection ability from a visual attention perspective. Such insights provide a solid basis for developing effective safety interventions and attentional guidance-based safety training methods to mitigate relevant site accidents.
•Mental fatigue induced by prolonged operating task is assessed by utilizing wearable eye tracker.•The decrement of hazard detection ability is quantified using eye movement metrics.•The impairing effect of mental fatigue on operators' ability to detect hazard was found.•Interventions and training methods have been discussed to reduce hazard detection failures.
Senescence and altered differentiation potential of bone marrow stromal cells (BMSCs) lead to age‐related bone loss. As an important posttranscriptional regulatory pathway, alternative splicing (AS) ...regulates the diversity of gene expression and has been linked to induction of cellular senescence. However, the role of splicing factors in BMSCs during aging remains poorly defined. Herein, we found that the expression of the splicing factor Y‐box binding protein 1 (YBX1) in BMSCs decreased with aging in mice and humans. YBX1 deficiency resulted in mis‐splicing in genes linked to BMSC osteogenic differentiation and senescence, such as Fn1, Nrp2, Sirt2, Sp7, and Spp1, thus contributing to BMSC senescence and differentiation shift during aging. Deletion of Ybx1 in BMSCs accelerated bone loss in mice, while its overexpression stimulated bone formation. Finally, we identified a small compound, sciadopitysin, which attenuated the degradation of YBX1 and bone loss in old mice. Our study demonstrated that YBX1 governs cell fate of BMSCs via fine control of RNA splicing and provides a potential therapeutic target for age‐related osteoporosis.
Synopsis
Alternative splicing has been shown to regulate cellular senescence and differentiation. This study links the reduced expression of the splicing regulator YBX1 in aging bone marrow stromal cells to senescence and aging‐related bone loss.
The expression level of YBX1 in BMSCs decreases during aging.
Ybx1 overexpression in BMSCs stimulates bone formation, while its deletion accelerates bone loss.
YBX1 suppresses BMSC senescence and modulates BMSC differentiation by controlling RNA splicing.
The small compound sciadopitysin attenuates YBX1 degradation and bone loss in old mice.
Reduced expression of YBX1 in aging bone marrow stromal cells induces their senescence and bone loss due to mRNA mis‐splicing.
Ni2P/Cd0.5Zn0.5S showed higher activity than pure Cd0.5Zn0.5S for photocatalytic N2 fixation without any scavengers under visible light irradiation (λ>400nm), and the concentration of NH3 reached to ...101.5μmolL−1 with quantum efficiency of 4.32% at 420nm. Display omitted
•Ni2P/Cd0.5Zn0.5S was synthesized and characterized.•Ni2P/Cd0.5Zn0.5S had higher activity than Cd0.5Zn0.5S for photocatalytic N2 fixation.•TMP improved the photo-induced carrier separation efficiency ofCd0.5Zn0.5S.
In this paper, transition metal phosphide (TMP) was used as cocatalyst to enhance the photocatalytic activity of Cd0.5Zn0.5S solid solution for nitrogen fixation under visible light irradiation. The Ni2P/Cd0.5Zn0.5S photocatalyst was characterized by X-ray diffraction patterns (XRD), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectra (DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic data showed that Ni2P/Cd0.5Zn0.5S had higher activity than pure Cd0.5Zn0.5S for photocatalytic dinitrogen (N2) fixation in the absence of any scavengers. After 1h visible light irradiation (λ>400nm), the concentration of NH3 reached to 101.5μmolL−1. And the quantum efficiency at 420nm monochromatic light reached 4.32%, which much higher than other semiconductors. Time-resolved PL spectra, photocurrent and electrochemical impedance (EIS) spectroscopy revealed that higher photo-induced carrier separation efficiency of Ni2P/Cd0.5Zn0.5S. This work introduced Cd0.5Zn0.5S solid solution photocatalyst to reduce nitrogen, and offered a greenly, economically and efficiently way for nitrogen fixation.
To explore the effect and mechanism of action of miR-210 on postmenopausal osteoporosis (PMPO) in ovariectomized rats in vivo.
An ovariectomized (OVX) rat model was established by ovariectomy. Tail ...vein injection was performed to overexpress and knock down miR-210 in OVX rats, followed by the collection of blood and femoral tissues from each group of rats. And quantitative real-time polymerase chain reaction (qRT-PCR) was applied to assess the expression level of miR-210 in femoral tissues of each group. Micro computed tomography (Micro CT) was adopted to scan the microstructure of the femoral trabecula in each group to obtain relevant data like bone mineral density (BMD), bone mineral content (BMC), trabecular bone volume fraction (BV/TV), trabecular thickness (Tb.Th), bone surface-to-volume ratio (BS/BV), and trabecular separation (Tb.Sp). ELISA was used for determining the level of bone alkaline phosphatase (BALP), amino-terminal propeptide of type I procollagen (PINP), osteocalcin (OCN), and C-terminal telopeptide of type I collagen (CTX-1) in serum; and Western blot for the protein level of Runt-related transcription factor 2 (Runx2), osteopontin (OPN), and collagen type I alpha 1 (COL1A1) in femoral tissues.
MiR-210 expression was significantly decreased in femoral tissues of OVX rats. Overexpression of miR-210 could obviously increase BMD, BMC, BV/TV and Tb.Th, whereas significantly decrease BS/BV and Tb.Sp in femurs of OVX rats. Moreover, miR-210 also downregulated BALP and CTX-1 level, upregulated PINP and OCN level in the serum of OVX rats promoted the expression of osteogenesis-related markers (Runx2, OPN and COL1A1) in the femur of OVX rats. Additionally, further pathway analysis revealed that high expression of miR-210 activated the vascular endothelial growth factor (VEGF)/Notch1 signaling pathway in the femur of OVX rats.
High expression of miR-210 may improve the micromorphology of bone tissue and modulate bone formation and resorption in OVX rats by activating the VEGF/Notch1 signaling pathway, thereby alleviating osteoporosis. Consequently, miR-210 can serve as a biomarker for the diagnosis and treatment of osteoporosis in postmenopausal rats.
Abstract
Injection molding products made of aluminum flakes and polymer blends exhibit a distinctive esthetic effect. However, during the filling process, the melt flows in different directions ...converge and collide, resulting in the flop effect of the aluminum flake and consequent weld line formation. Herein, microcellular injection molding (MIM) was employed to fabricate polypropylene/aluminum flakes (PP/Al) composite foamed parts with distinct weld lines using supercritical nitrogen (scN
2
) as the physical blowing agent. The scN
2
content has a significant effect on cell diameter and cell density. When the scN
2
content was 0.6%, the weld line width of the foamed part was 13.03 μm, while it was 30.41 μm for the solid counterpart due to the expansion and rupture of cells in the flow front during filling. Moreover, the orientation of Al flakes was mostly along the flow direction for the foamed parts, while it was generally aligned perpendicular to the flow direction for solid parts in the weld line region. In addition, the flexural modulus of foamed parts was increased by 29% compared with the solid parts, although the tensile strength was reduced by 18% due to the alignment of Al flakes and the stress concentration on the cell walls. Therefore, this work provides insight into the improvement of flexural property and the mitigation of weld lines for injection molded composite parts using MIM.
Background and Aims
NASH is associated with high levels of cholesterol and triglyceride (TG) in the liver; however, there is still no approved pharmacological therapy. Synthesis of cholesterol and TG ...is controlled by sterol regulatory element‐binding protein (SREBP), which is found to be abnormally activated in NASH patients. We aim to discover small molecules for treating NASH by inhibiting the SREBP pathway.
Approach and Results
Here, we identify a potent SREBP inhibitor, 25‐hydroxylanosterol (25‐HL). 25‐HL binds to insulin‐induced gene (INSIG) proteins, stimulates the interaction between INSIG and SCAP, and retains them in the endoplasmic reticulum, thereby suppressing SREBP activation and inhibiting lipogenesis. In NASH mouse models, 25‐HL lowers levels of cholesterol and TG in serum and the liver, enhances energy expenditure to prevent obesity, and improves insulin sensitivity. 25‐HL dramatically ameliorates hepatic steatosis, inflammation, ballooning, and fibrosis through down‐regulating the expression of lipogenic genes. Furthermore, 25‐HL exhibits both prophylactic and therapeutic efficacies of alleviating NASH and atherosclerosis in amylin liver NASH model diet‐treated Ldlr−/− mice, and reduces the formation of cholesterol crystals and associated crown‐like structures of Kupffer cells. Notably, 25‐HL lowers lipid contents in serum and the liver to a greater extent than lovastatin or obeticholic acid. 25‐HL shows a good safety and pharmacokinetics profile.
Conclusions
This study provides the proof of concept that inhibiting SREBP activation by targeting INSIG to lower lipids could be a promising strategy for treating NASH. It suggests the translational potential of 25‐HL in human NASH and demonstrates the critical role of SREBP‐controlled lipogenesis in the progression of NASH by pharmacological inhibition.
The present study was designed to clarify the mutual association of job burnout and insomnia and to detect the mediating effects of hair cortisol on that association.
In all, 68 female employees were ...recruited for the study from one secondary and one tertiary hospital between October 2018 and November 2018 in Beijing. Participants completed a questionnaire for the collection of demographic data and standardized measures for burnout and insomnia. Hair sample collection and anthropometric measurements were performed at the same time.
Median hair cortisol concentration (HCC) was 5.89 ng/g hair (interquartile range = 2.20–10.74). And ages are between 22 and 51 years old (32.50 ± 6.13), among which 22 were below 30 years, 20 were between 30 and 35 years, and 26 were over 35 years. A majority of Pearson's coefficients were significant, with the exception of that for the correlation between personal accomplishment and HCC or depersonalization. Significant mutual correlations were shown between burnout dimensions and insomnia directly. HCC acted as a mediator in the pathway from emotional exhaustion, depersonalization to insomnia; and no significant mediating effect of HCC in the pathway from insomnia to burnout was found.
Job burnout may directly or indirectly (through chronically elevated cortisol) increase insomnia risk, whereas insomnia probably promotes burnout. Prospective studies involving different body systems and a larger sample size should be performed to further identify the mechanisms underlying the associations between burnout and insomnia among the working population.
Abstract Objectives We aim to assess if the relationship between short or long sleep duration and hypertension is present among adults from epidemiological evidence and to investigate the ...relationship quantitatively. Methods We performed a comprehensive search of cross-sectional and longitudinal studies using PubMed and the Cochrane Library through February 2012. Our search was supplemented by reviewing reference lists of original and relevant reviews. After the related data were extracted by two investigators independently, pooled odds ratios (ORs) or relative risks (RRs) were estimated using a random-effects model or a fixed-effects model. Publication bias was evaluated, while sensitivity and meta-regression analyses were performed. Results Twenty-four adult studies met our inclusion criteria, with ages ranging from 18 to 106 years. Twenty-one studies involving 225,858 subjects were included in the meta-analysis. The pooled results from the cross-sectional studies showed that short sleep duration was associated with a greater risk for hypertension (OR, 1.21; 95% confidence interval CI, 1.09–1.34; P < 0.001), and long sleep duration also increased the risk for hypertension (OR, 1.11; 95% CI, 1.04–1.18; P = 0.003). There was no evidence of publication bias. Pooled analysis from the longitudinal studies indicated a significant association between short sleep duration and hypertension (RR, 1.23; 95% CI, 1.06–1.42; P = 0.005), but an insignificant relationship between long sleep duration and hypertension (RR, 1.02; 95% CI, 0.91–1.14; P = 0.732). The effects of sleep duration differed by gender, location of the population, and definitions of short or long sleep duration. Meta regression analysis including seven variables did not find the sources of heterogeneity. Conclusions Among adults, a U-shaped relationship between habitual sleep duration and hypertension was found at the cross-sectional level. Short sleep duration was associated with a higher risk for hypertension even longitudinally. We must pay more attention to this lifestyle factor.
On 11 March 2011, a giant interplate earthquake of magnitude Mw 9.1 struck Tohoku-Oki area in eastern Japan. The earthquake is acknowledged to have permanently altered the stress field in and around ...the focal region. To capture the temporal change of the overall stress field, I examined 1251 focal mechanisms, from the NIED MT catalog, that occurred before and after the Tohoku-Oki earthquake from January, 2006 to January, 2017 in the focal region near the subducting slab. The examined observations were grouped into six periods, and based on the selected NIED MT catalog, the stress regime in each period was obtained by using the damped stress tensor inversion method. Based on the temporal evolution of stress rotation, the corresponding deviatoric stress level was estimated using a simplified 2D model. Results of the 10-year seismic stress cycle show that several years before the Tohoku-Oki earthquake, the stress accumulation level seems to have experienced an acceleration process. Studies suggest that this increasingly critically stress state combined with the sufficiently reduced coupling rate off the Tohoku area finally resulted in the unprecedented megathrust event. The coseismic process was violent and released almost all of the deviatoric stress that presented before the main shock. The resultant stress state even reached frictional overshoot. Thus, the postseismic stress pattern in the source region was reshaped significantly, especially for the upper plate and updip portion of the lower plate. After the main shock near the rupture surface, a surprisingly rapid and high-level stress reloading occurred within several postseismic years. To reconcile the classical subduction zone earthquake generation cycle model, the event may be described as an instantaneously decoupled stress state between the upper and inner plates.
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