As a kind of high temperature resistant material, glass fiber-reinforced epoxy resin (GFRE) plate is widely used in aviation and machinery fields. When GFRE is exposed to high temperature and ...high-speed airflow, it undergoes severe ablation, which affects its material and internal structure. In order to investigate the thermal effects and ablation behavior under high heat flux, a continuous laser was used to ablate a GFRE plate with different laser power levels. Then, a two-dimensional finite element model of laser ablation of GFRE was developed, taking into account the depth-dependent absorption of laser energy and the enthalpy change caused by the pyrolysis reaction. The mass loss results from the model were compared with those from the experiment and showed reasonable validity. Moreover, the changes in the internal composition of GFRE during ablation were also analyzed based on the experiment and model. It was found that the epoxy resin content decreased rapidly during ablation while the dehydrated epoxy resin and carbides increased continuously. Dehydration reaction was found to be the main factor for mass loss. Furthermore, the surface layer had more heat dissipation by convection and radiation than the deep layer. Hence, the chemical reactions in the surface layer ceased almost instantly after stopping the laser. However, the chemical reactions in the deep layer persisted for some time after removing the heat source.
Polycrystalline diamond compact (PDC) needs to remove cobalt from diamond layer to improve wear resistance and impact resistance. The traditional cobalt removal process has low efficiency and long ...time. In this paper, a mixed solvent of hydrochloric acid and Lewis acid (FeCl3) was used as cobalt removal reagents, pressurized chemical precipitation method was used to study the cobalt removal of PDC. The effects of different reagent ratio, reaction temperature and reaction pressure on the surface morphology and de‑cobalt depth of PDC were studied. The holes morphology of PDC surface after cobalt removal was analyzed by SEM and ImageJ2x image analysis software. The fractal dimension of the holes on the PDC surface was calculated by the Area-circumference method, and the relationship between fractal dimension of hole and de‑cobalt depth was studied. The results show that the cobalt in PDC can be efficiently removed by pressure chemical precipitation method. The relationship between fractal dimension of the holes and the depth of cobalt removal is established. The cobalt removal efficiency of pressurized chemical precipitation method is higher than that of conventional acid leaching method. After cobalt removal, the wear resistance and impact toughness of PDC are further improved.
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•Cobalt removal process of pressurized chemical precipitation method•De‑cobalt depth increases by pressurized chemical precipitation method•Positive correlation between surface morphology of PDC and de‑cobalt depth.•The fractal dimension can detect quickly de‑cobalt depth
•Faxon fir showed a preferentially nutrient allocation to needles than other organs.•With the elevation increasing, Faxon fir may be limited by P.•As the climate warms, high-altitude Faxon fir will ...be increasingly with N-restricted.•Faxon fir made a cooperative change among nutrient, hydraulic, and morphological.
High-altitude mountain plants are at risk of extinction due to global warming. Our study examined the stoichiometric characteristics of high-altitude plants in response to a progressively warming climate, as well as exploring potential relationships between hydraulic conductivity efficiency, stoichiometric characteristics, and morphological traits. As the research object, it was decided to conduct this investigation using the Faxon fir, a dominant species in the Minjiang River Basin with better water conditions. The sampling time was four months. In July 2019, October 2019, January 2020, and April 2020, the stoichiometric characteristics (N and P) in needles, branches, stems, and roots of Faxon fir were measured along an altitude gradient at 200 m intervals from 2800 m to 3600 m. We also measured morphological traits and hydraulic traits. This study showed that the Faxon fir N P stoichiometric preferentially to needles, followed by branches and roots, and finally at the trunk, and the Faxon fir was in an N-restricted state. N and P elements exhibit a significant correlation with morphological traits, while the relationship between P elements and hydraulic characteristics is mediated indirectly through morphological traits. At high altitudes, climate warming will increase the N limitation of Faxon fir, but the effect on P limitation will be relatively limited. Climate environment and water status are closely related to the distribution of N P nutrients in the organs. Undoubtedly, climate change will directly affect the survival of high-altitude plants, and appropriate survival strategies can encourage plants to adapt to climate changes by balancing energy distribution among different organs and tissues.
Inflammatory macrophages play pivotal roles in the development of atherosclerosis. Theranostics, a promising approach for local imaging and photothermal therapy of inflammatory macrophages, has drawn ...increasing attention in biomedical research. In this study, gold nanorods (Au NRs) were synthesized, and their in vitro photothermal effects on the macrophage cell line (Ana-1 cells) under 808 nm near infrared reflection (NIR) were investigated by the CCK8 assay, calcein AM/PI staining, flow cytometry, transmission electron microscopy (TEM), silver staining and in vitro micro-computed tomography (CT) imaging. These Au NRs were then applied to an apolipoprotein E knockout (Apo E) mouse model to evaluate their effects on in vivo CT imaging and their effectiveness as for the subsequent photothermal therapy of macrophages in femoral artery restenosis under 808 nm laser irradiation. In vitro photothermal ablation treatment using Au NRs exhibited a significant cell-killing efficacy of macrophages, even at relatively low concentrations of Au NRs and low NIR powers. In addition, the in vivo results demonstrated that the Au NRs are effective for in vivo imaging and photothermal therapy of inflammatory macrophages in femoral artery restenosis. This study shows that Au nanorods are a promising theranostic platform for the diagnosis and photothermal therapy of inflammation-associated diseases.
Using a reading comprehension task, we explored whether body postures would influence mind wandering, a universal internally self-generated activity. Specifically, participants were instructed to ...perform a reading comprehension task under three postural conditions (lying supine, sitting, and standing upright). Probe-caught technique with prompts presented at irregular intervals was adapted to measure the frequency of mind wandering. Self-caught method was used to measure the meta-awareness of mind wandering by self-reports. Results indicated that the radio of mind wandering was significantly greater in lying than standing and sitting, but the meta-awareness of it was not different among three postures. Moreover, the reading performance, an indirect indicator of executive control, decreased in lying compared to standing and sitting. We suggested that the increase of mind wandering in lying posture may due to the dysfunction of executive control, which also results in the redistribution of cognitive resources. Suggestions for future research are proposed.
At present, there are no available genetic data on the AGCU EX22 Kit from the Wuhu Han population.
This study investigates the applicability of the AGCU EX22 kit, designed for the Chinese population ...for forensic analysis and population genetics of the Wuhu Han population.
Bloodstains from 1565 unrelated healthy individuals in Wuhu city, Anhui Province, were collected for analysis. The AGCU EX22 kit was used for amplification, and capillary electrophoresis was used to separate the amplification products. Allele frequencies and forensic parameters were determined. The Wuhu Han population was compared to 10 reference populations through genetic distance, a phylogenetic neighbor-joining tree and principal component analysis.
In total, 281 alleles and 1187 genotypes were observed. No significant deviations from Hardy-Weinberg equilibrium at any locus were found after Bonferroni's correction. The 21 autosomal short tandem repeat (STR) genetic markers exhibited high informativeness and polymorphism. The cumulative power of discrimination and power of exclusion were 0.999999999999999999999999913380 and 0.999999996752339, respectively. Population comparisons revealed a genetic affinity between Wuhu Han and southern Han populations, except for the Guangdong Han population, which aligned with the traditional geographical division in China.
The AGCU EX22 Kit, containing 21 STR loci, is suitable for forensic application and population genetics studies in the Wuhu Han population.
Celotno besedilo
Dostopno za:
DOBA, FSPLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Fluid shear stress (FSS) facilitates bone remodeling by regulating osteogenic differentiation, and extracellular matrix maturation and mineralization. However, the underlying molecular mechanisms of ...how mechanical stimuli from FSS are converted into osteogenesis remain largely unexplored. Here, we exposed MC3T3-E1 cells to FSS with different intensities (1 h FSS with 0, 5, 10, and 20 dyn/cm
intensities) and treatment durations (10 dyn/cm
FSS with 0, 0.5, 1, 2 and 4 h treatment). The results demonstrate that the 1 h of 10 dyn/cm
FSS treatment greatly upregulated the expression of osteogenic markers (Runx2, ALP, Col I), accompanied by AnxA6 activation. The genetic ablation of AnxA6 suppressed the autophagic process, demonstrating lowered autophagy markers (Beclin1, ATG5, ATG7, LC3) and decreased autophagosome formation, and strongly reduced osteogenic differentiation induced by FSS. Furthermore, the addition of autophagic activator rapamycin to AnxA6 knockdown cells stimulated autophagy process, and coincided with more expressions of osteogenic proteins ALP and Col I under both static and FSS conditions. In conclusion, the findings in this study reveal a hitherto unidentified relationship between FSS-induced osteogenic differentiation and autophagy, and point to AnxA6 as a key mediator of autophagy in response to FSS, which may provide a new target for the treatment of osteoporosis and other diseases.
Recent studies suggest that Src family kinase (SFK) plays important roles in systemic sclerosis and pulmonary fibrosis. However, how SFKs contributed to the pathogenesis of liver fibrosis remains ...largely unknown. Here, we investigated the role of Fyn, a member of SFK, in hepatic stellate cell (HSC) activation and liver fibrosis, and evaluated the anti-fibrotic effects of Saracatinib, a clinically proven safe Fyn inhibitor. Fyn activation was examined in human normal and fibrotic liver tissues. The roles of Fyn in HSC activation and liver fibrosis were evaluated in HSC cell lines by using Fyn siRNA and in Fyn knockout mice. The effects of Saracatinib on HSC activation and liver fibrosis were determined in primary HSCs and CCl
induced liver fibrosis model. We showed that the Fyn was activated in the liver of human fibrosis patients. TGF-β induced the activation of Fyn in HSC cell lines. Knockdown of Fyn significantly blocked HSC activation, proliferation, and migration. Fyn deficient mice were resistant to CCl
induced liver fibrosis. Saracatinib treatment abolished the activation of Fyn, downregulated the Fyn/FAK/N-WASP signaling in HSCs, and subsequently prevented the activation of HSCs. Saracatinib treatment significantly reduced the severity liver fibrosis induced by CCl
in mice. In conclusions, our findings supported the critical role of Fyn in HSC activation and development of liver fibrosis. Fyn could serve as a promising drug target for liver fibrosis treatment. Fyn inhibitor Saracatinib significantly inhibited HSC activation and attenuated liver fibrosis in mouse model.
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