Transformer oil, crucial for transformer and power system safety, demands effective monitoring. Aiming to address the problems of expensive and bulky equipment, poor real-time performance, and single ...parameter detection of traditional measurement methods, this study proposes a quartz tuning fork-based simultaneous measurement system for online monitoring of the density, viscosity, and dielectric constant of transformer oil. Based on the Butterworth-Van Dyke quartz tuning fork equivalent circuit model, a working mechanism of transformer oil density, viscosity, and dielectric constant was analyzed, and a measurement model for oil samples was obtained. A miniaturized simultaneous measurement system was designed based on a dedicated chip for vector current-voltage impedance analysis for data acquisition and a Savitzky-Golay filter for data filtering. A transformer oil test platform was built to verify the simultaneous measurement system. The results showed that the system has good repeatability, and the measurement errors of density, viscosity, and dielectric constant are lower than 2.00%, 5.50%, and 3.20%, respectively. The online and offline results showed that the system meets the requirements of the condition maintenance system for online monitoring accuracy and real-time detection.
Mesoporous silica nanoparticles (MSNs) carrying gatekeepers that are stimuli-responsive are widely investigated for the controlled delivery of drug at target sites. In this study, thioketal (TK) ...functionalized methoxy poly(ethylene glycol) (mPEG-TK) as ROS-responsive gatekeeper is used to modify MSNs and leads to a reactive oxygen species (ROS)-responsive delivery for antibacterial drug. Vancomycin (Van) was taken as the antibacterial drug and then physically encapsulated into the surface amino functionalized MSNs (N-MSNs). Subsequently, mPEG-TK was surface immobilized. Van loaded N-MSNs with surface modification of mPEG-TK (Van-mPEG-TK-MSNs) presented approximately 21% release of Van in a physiological environment in 36 h. With H2O2 increasing in the medium, the release rate of Van from Van-mPEG-TK-MSNs was significantly up-regulated following gatekeepers' disintegration. When Van-mPEG-TK-MSNs was applied in vivo, the infected site was fully cleared after 14 days and the tissue was free of infection. On the whole, the mentioned results suggested that Van-mPEG-TK-MSNs could act as a potential antimicrobial. This study can broaden MSNs' applications and advance the development of novel antibacterial agents.
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•Thioketal-gated mesoporous silica nanoparticles were successfully developed for vancomycin encapsulation and release.•The gated nanoparticle provided a sensitive release of vancomycin dependent on the reactive oxygen species.•Vancomycin released within 6 h from the gated nanoparticles was approximately 10 times less than from no-gate nanoparticles.•Within 14 days, the gated nanoparticles with vancomycin loading, effectively cleared infection in vivo.
To better improve the conditions for the recovery of children with burn injuries, timely understanding of the psychological status of parents is important. A cross-sectional survey on it using ...convenience sampling was conducted at two hospitals. Besides basic information, the Symptom Checklist 90, Eysenck Personality Questionnaire, Social Support Rate Scale, and Simplified Coping Style Questionnaire were used, and the key factors were identified via multivariate linear regression analysis and path analysis. A total of 196 guardians were recruited, 180 valid and completed questionnaires were obtained, including 58 men (32.2%) and 122 women (67.8%), and their average age was 30.3 years (standard deviation = 7.6). Of these, 151 participants (83.9%) were parents. Multivariate analysis revealed that children's age, parent gender, P score, negative coping style, and religion were the main factors that affected parents' psychology. Moreover, path analysis showed that P score, children's age, and negative coping style had the greatest impact on the total average score. These results suggest that during hospitalization, the following three factors should be focused on: older children, higher parental psychoticism, and increased negative coping style.
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•The high expression of circ_000999 facilitated the occurrence of EMT in cadmium-induced malignant transformation.•Circ_000999 promoted EMT in Cd-induced malignant transformation of ...16HBE cells through miR-205-5p/ZEB1 axis.•EIF4A3 interacted with the parental gene AGTPBP1 to regulate high expression of circ_000999 in the process ofCd-induced EMT.
Cadmium (Cd) is an accumulative toxic metal which poses a serious threat to human health, even in trace amounts. One of the most important steps in the pathophysiology of lung cancer (LC) is the epithelial-mesenchymal transition (EMT). In this investigation, a cell malignant transformation model was established by exposing human bronchial epithelial cells (16HBE) to a low dose of Cd for 30 weeks, after which a highly expressed circular RNA (circ_000999) was identified. Cd-induced EMT was clearly observed in rat lungs and 16HBE cells, which was further enhanced following circ_000999-overexpression. Furthermore, upregulated EIF4A3 interacted with the parental gene AGTPBP1 to promote high expression of circ_000999. Subsequent experiments confirmed that circ_000999 could regulate the EMT process by competitively binding miR-205-5p and inhibiting its activity, consequently upregulating expression of zinc finger E-box binding protein 1 (ZEB1). Importantly, the circ_000999 expression level in LC tissues was significantly increased, exhibiting a strong correlation with EMT indicators. Overall, these findings provide a new objective and research direction for reversing lung EMT and subsequent treatment and prevention of LC.
RAS (H-ras, K-ras, and N-ras), as the second largest mutated gene driver in various human cancers, has long been a vital research target for cancer. Its function is to transform the extracellular ...environment into a cascade of intracellular signal transduction. RAS mutant protein regulates tumor cell proliferation, apoptosis, metabolism and angiogenesis through downstream MAPK, PI3K and other signaling pathways. In KRAS or other RAS-driven cancers, current treatments include direct inhibitors and upstream/downstream signaling pathway inhibitors. However, the research on these inhibitors has been largely restricted due to their escape inhibition and off-target toxicity. In this paper, we started with the role of normal and mutant RAS genes in cancer, elucidated the relevant RAS regulating pathways, and highlighted the important research advancements in RAS inhibitor research. We concluded that for the crosstalk between RAS pathways, the effect of single regulation may be limited, and the multi-target drug combined compensation mechanism is becoming a research hotspot.
This paper utilizes computed tomography (CT) real–time observation technology to investigate the damage mechanism of frozen loess under loading and unloading. The intrinsic connections between ...macroscopic mechanical degradation and mesoscopic damage in frozen loess were established through a comparative analysis of macroscopic mechanical parameters (such as dissipation energy and elastic strain energy) and mesoscopic structural parameters (such as porosity increment and mesoscopic structural damage increment) of frozen loess under loading and unloading. Furthermore, the relationships between damage variables at different scales under the effects of loading and unloading were explored. The experimental results demonstrate that during the elastic strain stage, the dissipated energy, porosity increment, and microscopic damage increment of frozen soil exhibit a linear increase with strain. Following loading and unloading, the porosity is unable to be fully restored to its original state due to the development of new cracks. At this stage, the deformation is not entirely elastic and includes some plastic deformation. During the plastic deformation stage, the dissipated energy tends to stabilize, while the porosity increment and microscopic damage increment continue to increase substantially. The pore structure of a specimen undergoes significant alterations, with increased displacement and rearrangement of soil particles and ongoing expansion of cracks. The damage evolution trends at both the macroscale and mesoscale remain consistent during this stage. This study offers insights into the construction of a cross–scale macroscale/mesoscale ontological damage model, serving as a valuable reference for future research.
•Study investigates the damage mechanism of frozen loess under loading and unloading using CT observation technology.•The link between the degradation of macro-mechanical properties and the mesoscopic damage of frozen loess is revealed.•Explore the relationship between damage variables at different scales.
Copper is a transition metal that plays critical roles in many life processes. Controlling the cellular concentration and trafficking of copper offers a route to disrupt these processes. Here we ...report small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS, and so provide a selective approach to disrupt cellular copper transport. The knockdown of Atox1 and CCS or their inhibition leads to a significantly reduced proliferation of cancer cells, but not of normal cells, as well as to attenuated tumour growth in mouse models. We show that blocking copper trafficking induces cellular oxidative stress and reduces levels of cellular ATP. The reduced level of ATP results in activation of the AMP-activated protein kinase that leads to reduced lipogenesis. Both effects contribute to the inhibition of cancer cell proliferation. Our results establish copper chaperones as new targets for future developments in anticancer therapies.
Abstract
Vacuum Insulation Panels (VIPs) are highly efficient thermal insulation materials with extremely low thermal conductivity based on the vacuum principle. With the sealing properties of the ...gas barrier envelopes, a long service life of the VIP is obtained. The mechanism and influence factors of gas and water vapor permeability were mathematically analyzed to explore the influence of gas barrier envelopes on the thermal performance of VIPs. Three typical gas barriers were studied, and the selection of the gas barrier and other aspects of optimization were involved. The relationships among temperature, humidity, solubility coefficient, diffusion coefficient, and permeability were concluded, which shows that temperature has a much greater effect on the permeability of the gas barrier relative to humidity. The numerical analysis and influencing factors of VIPs’ service life were also exemplified with three different types of gas barrier envelopes. The experimental results show that depending on the environment, the temperature has a major impact on the effective thermal conductivity and service life of VIP. The research was significant in the selection of gas barriers, the optimization of the performance, and the development of vacuum insulation material.
Frost damage in engineering is closely related to hydraulic pressure in artificial freezing ground areas and cold regions; however, limited studies have focused on this relationship. To clarify the ...evolution of frost heave-induced pressure (FHIP) and its effect on engineering stability, unidirectional freezing tests are performed under rigid constraint and various hydraulic pressures. The results indicate that the development of the FHIP is induced by ice growth. Meanwhile, the FHIP increases with hydraulic pressure, which consequently increases the pore water pressure (PWP) at the base of the warmest ice lens. When the PWP on both sides of the frozen fringe reaches equilibrium, the water stops migrating, ice stops growing, and FHIP stops increasing. The frozen fringe is captured via X-ray computed tomography, and a model for calculating the maximum FHIP is developed based on the frozen fringe theory. The model is validated and compared with the experimental results. The increased FHIP prevents water migration in freezing soil by increasing the soil density and decreasing the segregation temperature of the frozen fringe. Additionally, the factors contributing to the increase in FHIP are discussed, and an application of this study to engineering design and maintenance in cold regions is proposed.
•The frozen fringe in freezing soil was observed by CT.•The frost heave induced pressure increases with increasing hydraulic pressure.•The frost heave induced pressure stops increasing as the ice stops growing.•The method for calculating the maximum frost heave induced pressure was proposed.
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The aggregation of graphene oxide (GO) is considered as main challenge, although GO possesses excellent mechanical properties which arouses widespread attention as reinforcement for ...polymers.
In this study, silicon dioxide (SiO2) nanoparticles were decorated onto surface of GO nanosheets through in situ growth method for promoting dispersion of GO in poly(l-lactic acid) (PLLA) bone scaffold.
Hydroxyl and carboxyl functional groups of GO provided sites for SiO2 nucleation, and SiO2 grew with hydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) and finally formed nanoparticles onto surface of GO with covalent bonds. Then, the GO@ SiO2 nanocomposite was blended with PLLA for the fabrication of bone scaffold by selective laser sintering (SLS).
The results indicated that the obtained SiO2 were distributed relatively uniformly on surface of GO under TEOS concentration of 0.10 mol/L (GO@SiO2-10), and the covering of SiO2 on GO could increase interlayer distance of GO nanosheets from 0.799 nm to 0.894 nm, thus reducing van der Waals forces between GO nanosheets and facilitating the dispersion. Tensile and compressive strength of scaffold containing GO@SiO2 hybrids were significantly enhanced, especially for the scaffold containing GO@SiO2-10 hybrids with enhancement of 30.95 % in tensile strength and 66.33 % in compressive strength compared with the scaffold containing GO. Additionally, cell adhesion and fluorescence experiments demonstrated excellent cytocompatibility of the scaffold.
The good dispersion of GO@SiO2 enhances the mechanical properties and cytocompatibility of scaffold, making it a potential candidate for bone tissue engineering applications.
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