•The theoretical model of cavity under various transient P wave loads is obtained.•Stress distributions around cavity of high and low frequency loads are different.•Waveform and burial depth affect ...the stress amplitude around cavity.•Convergence of solutions are investigated.•The existence of linear boundary increases the risk of tensile failure around cavity.
The failure of underground structure is always caused by local stress redistribution resulted from transient impact loads. An analytical model is established and solved by using the complex variable function method to illustrate the dynamic stress concentration around a shallow-buried cavity under transient P wave loads. The transient wave response is attained as an integration of steady-state wave response in circular frequency domain. By adopting a Butterworth filter, the jump points in the dynamic stress concentration factor (DSCF) curve which is not in line with the overall trend is filtered out to obtain more reasonable results. The convergence and accuracy of the solutions are verified and discussed in detail. DSCF distributions of high wavenumber incidences differ from that of low wavenumber incidences significantly in amplitudes and distribution patterns. The effects of the cavity depth, incidence angle and position of wave peak on DSCF distributions are illustrated.
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•Sb2Te3 topological nanosheets are promising to achieve ultra-thin EMI shielding.•The EMI SE can be modulated by changing the nanosheet thickness.•The material shows a PTC of ...electrical conductivity and EMI shielding.
Topological insulators exhibit a new variety of unusual phenomena associated with topologically protected gapless surface states. Interestingly, most topological insulators are possibly outstanding electromagnetic shielding materials due to the easily adjustable electric transport performance, which can be controlled by regulating nanostructures based on conducting surface states. Herein, a series of Sb2Te3 nanosheets with different thicknesses were prepared by a hydrothermal method. The electrical conductivity increases as the thickness of the topological nanosheet decreases, so the nanosheet aggregates exhibit an extraordinary electromagnetic response behavior different from metallic materials, which is beneficial to achieving excellent electromagnetic shielding in applications of integrated circuit field. Moreover, Sb2Te3 nanosheet aggregates show a positive temperature coefficient of electrical conductivity that it increases monotonically with increasing temperature in the entire range of 313–573 K. The effect of positive temperature coefficient implies that the longitudinal conductance plays a dominant role in Sb2Te3 nanosheet aggregates. An equivalent circuit model was proposed to describe the unique electrical conductance behavior of nanosheet aggregates for topological insulators. The outstanding electromagnetic shielding performance and positive temperature correlation make Sb2Te3 nanosheets emerging in next-generation electronic equipments and aerospace applications in high-temperature environments.
With the recent recognition of non-coding RNAs (ncRNAs) flanking many genes, a central issue is to obtain a full understanding of their potential roles in regulated gene transcription programmes, ...possibly through different mechanisms. Here we show that an RNA-binding protein, TLS (for translocated in liposarcoma), serves as a key transcriptional regulatory sensor of DNA damage signals that, on the basis of its allosteric modulation by RNA, specifically binds to and inhibits CREB-binding protein (CBP) and p300 histone acetyltransferase activities on a repressed gene target, cyclin D1 (CCND1) in human cell lines. Recruitment of TLS to the CCND1 promoter to cause gene-specific repression is directed by single-stranded, low-copy-number ncRNA transcripts tethered to the 5' regulatory regions of CCND1 that are induced in response to DNA damage signals. Our data suggest that signal-induced ncRNAs localized to regulatory regions of transcription units can act cooperatively as selective ligands, recruiting and modulating the activities of distinct classes of RNA-binding co-regulators in response to specific signals, providing an unexpected ncRNA/RNA-binding protein-based strategy to integrate transcriptional programmes.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background and Objectives: While the health promoting effects of green tea polyphenols have been identified among adult, research on children is scarce probably due to safety concerns about caffeine. ...This study aims to evaluate the safety of decaffeinated green tea polyphenols (DGTP) supplementation in girls with obesity and lay the foundation for its application in children population. Methods and Study Design: This 12-week randomized, double-blinded, parallel-controlled trial was performed among 62 girls with obesity aged 6 to 10 years old. Participants were allocated to take 400 mg/d DGTP (DGTP group, n equivalent 31) or isodose placebo (Control group, n equivalent 31) at random. Anthropometric measurements and biochemical parameters including hepatic and renal function indicators, serum minerals concentrations, and routine blood parameters, were measured at baseline and the end of this trial. DGTP intake diary was required for each participant to record any abnormal reactions. Results: After the 12-week supplementation, compared to Control group, the uric acid concentration in DGTP group showed a significant decrease (-48.0 +- 83.2 vs -0.01 +- 69.1, mumol/L), within the normal range. Regarding other biochemical indicators, there were no significant differences in changed values between the two groups. Throughout the trial, no adverse effects were reported in either group. Conclusions: This study indicated that the supplementation of 400 mg/d DGTP for 12 weeks had no adverse health effects in girls with obesity, providing evidence for the DGTP adoption in children research.
The acoustic emission (AE) and microseismic (MS) monitoring are efficient methods to detect faults/breaking signals for both healthy evaluation and disaster control in mining engineering. This paper ...presents an MS or AE source location method without the need for a pre-measured wave velocity. It can eliminate the location errors for MS/AE monitoring systems caused by the deviations of the wave velocity. To verify the applicability of the proposed method, first, tests of both the pencil lead break and the thermal fracture in granite were carried out, and location errors were compared and analyzed. Results show that the location accuracy of the proposed method is significantly improved, which is superior to the results of the traditional location method (TM) using pre-measured wave velocity. Second, blasting experiments were carried out in Dongguashan copper mine in China. The blasts were used as simulated seismic sources. Average values of absolute distance errors of the MS/AE source locations resulting from the proposed method without wave velocity and the traditional method using average measured wave velocity are 10.16 and 17.55 m, respectively. It shows that the calculated locations by the proposed method are in better agreement with the real blast coordinates. Third, the proposed method is also applied to previously published data. It gives superior results compared with the considered existing methods. Results of the pencil lead break tests, the thermal fracture experiment in granite, and the blasting experiments (including published data) have demonstrated that the proposed method can not only decrease the location errors induced by measurement deviation of velocity, but also locate the MS/AE source in real time, which is a beneficial complement to the method TM in mines.
In this study, immersion experiments were conducted on the geopolymer mortar (GPM) by using artificial seawater, and the effects of alkali equivalent (AE) and waterglass modulus (WGM) on the ...resistance of geopolymer mortar (GPM) to seawater immersion were analyzed. The test subjected 300 specimens to 270 days of artificial seawater immersion and periodic performance tests. Alkali equivalent (AE) (3-15%) and waterglass modulus (WGM) (1.0-1.8) were employed as influencing factors, and the mass loss and uniaxial compressive strength (UCS) were used as the performance evaluation indexes, combined with X-ray diffraction (XRD) and scanning electron microscopy (SEM) to analyze the time-varying pattern of geopolymer mortar (GPM) performance with seawater immersion. The findings demonstrated a general trend of initially growing and then declining in the uniaxial compression strength (UCS) of geopolymer mortar (GPM) under seawater immersion. The resistance of geopolymer mortar (GPM) to seawater immersion decreased with both higher or lower alkali equivalent (AE), and the ideal range of alkali equivalent (AE) was 9-12%. The diffusion layer of the bilayer structure of the waterglass particle became thinner with an increase in waterglass modulus (WGM), which ultimately led to the reduction in the resistance of the geopolymer structure to seawater immersion. Additionally, a support vector regression (SVR) model was developed based on the experimental data to predict the uniaxial compression strength (UCS) of GPM under seawater immersion. The model performed better and was able to achieve accurate prediction within 1-2 months, and provided an accurate approach to predicting the strength of geopolymer materials in a practical offshore construction project.
Angiogenesis is closely associated with tumorigenesis, invasion, and metastasis by providing oxygen and nutrients. Recently, increasing evidence indicates that cancer‐derived exosomes which contain ...proteins, coding, and noncoding RNAs (ncRNAs) were shown to have proangiogenic function in cancer. A 26‐nt‐long ncRNA (X26nt) is generated in the process of inositol‐requiring enzyme 1 alpha (IRE1α)‐induced unspliced XBP1 splicing. However, the role of X26nt in the angiogenesis of gastric cancer (GC) remains largely unknown. In the present study, we found that X26nt was significantly elevated in GC and GC exosomes. Then, we verified that X26nt could be delivered into human umbilical vein endothelial cells (HUVECs) via GC cell exosomes and promote the proliferation, migration, and tube formation of HUVECs. We revealed that exosomal X26nt decreased vascular endothelial cadherin (VE‐cadherin) by directly combining the 3′UTR of VE‐cadherin mRNA in HUVECs, thereby increasing vascular permeability. We further demonstrated that X26nt accelerates the tumor growth and angiogenesis in a mouse subcutaneous tumor model. Our findings investigate a unique intercellular communication mediated by cancer‐derived exosomes and reveal a novel mechanism of exosomal X26nt in the regulation of tumor vasculature.
Our results revealed that gastric cancer exosomal 26‐nt‐long ncRNA (X26nt) promotes human umbilical vein endothelial cells (HUVECs) proliferation, migration, and tube formation via decreasing vascular endothelial cadherin (VE‐cadherin), which facilitates angiogenesis. We further demonstrated that X26nt accelerates tumor growth and angiogenesis in a mouse subcutaneous tumor model. Our findings investigate a unique intercellular communication mediated by cancer‐derived exosomes and reveal a novel mechanism of exosomal X26nt in the regulation of tumor vasculature.
Previous studies on the endotyping of chronic rhinosinusitis (CRS) that were based on inflammatory factors have broadened our understanding of the disease. However, the endotype of CRS combined with ...inflammatory and remodeling features has not yet been clearly elucidated.
We sought to identify the endotypes of patients with CRS according to inflammatory and remodeling factors.
Forty-eight inflammatory and remodeling factors in the nasal mucosal tissues of 128 CRS patients and 24 control subjects from northern China were analyzed by Luminex, ELISA, and ImmunoCAP. Sixteen factors were used to perform the cluster analysis. The characteristics of each cluster were analyzed using correlation analysis and validated by immunofluorescence staining.
Patients were classified into 5 clusters. Clusters 1 and 2 showed non-type 2 signatures with low biomarker concentrations, except for IL-19 and IL-27. Cluster 3 involved a low type 2 endotype with the highest expression of neutrophil factors, such as granulocyte colony-stimulating factor, IL-8, and myeloperoxidase, and remodeling factors, such as matrix metalloproteinases and fibronectin. Cluster 4 exhibited moderate type 2 inflammation. Cluster 5 exhibited high type 2 inflammation, which was associated with relatively higher levels of neutrophil and remodeling factors. The proportion of CRS with nasal polyps, asthma, allergies, anosmia, aspirin sensitivity, and the recurrence of CRS increased from clusters 1 to 5.
Diverse inflammatory mechanisms result in distinct CRS endotypes and remodeling profiles. The explicit differentiation and accurate description of these endotypes will guide targeted treatment decisions.
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Chromatin dynamics regulated by epigenetic modification is crucial in genome stability and gene expression. Various epigenetic mechanisms have been identified in the pathogenesis of human diseases. ...Here, we examined the effects of ten epigenetic agents on pseudorabies virus (PRV) infection by using GFP-reporter assays. Inhibitors of bromodomain protein 4 (BRD4), which receives much more attention in cancer than viral infection, was found to exhibit substantial anti-viral activity against PRV as well as a range of DNA and RNA viruses. We further demonstrated that BRD4 inhibition boosted a robust innate immune response. BRD4 inhibition also de-compacted chromatin structure and induced the DNA damage response, thereby triggering the activation of cGAS-mediated innate immunity and increasing host resistance to viral infection both in vitro and in vivo. Mechanistically, the inhibitory effect of BRD4 inhibition on viral infection was mainly attributed to the attenuation of viral attachment. Our findings reveal a unique mechanism through which BRD4 inhibition restrains viral infection and points to its potent therapeutic value for viral infectious diseases.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The acoustic emission b value is an important and widely used parameter for the early prediction of rock fractures. In this study, five groups of true triaxial compression tests were conducted on ...granite specimens to analyze changes in b value during the process of rock failure, and to investigate the b value characteristics of acoustic emission events. First, the acoustic emission events that simultaneously triggered at least four sensors were located using P-wave arrivals and sensor coordinates. Then, considering various intervals of acoustic emission event counts, stress magnitude, and stress proportion, b values were calculated using the values of the maximum amplitude, average amplitude, maximum absolute energy, and average absolute energy of the acoustic emission events. In addition, the goodness of the fitting curves was used to evaluate the fitting reliability of the b values. The results indicated higher accuracy of b value when calculated using the average amplitude setting for intervals of acoustic emission event counts of 200 or greater, stress magnitude of 20 MPa or greater, and stress proportion of 10% or greater. Moreover, the interval of event counts of 200 is suggested as a window parameter for b value calculations, and the b values are observed to exhibit a decreasing trend before fracture for more than 80% of the specimens. Furthermore, the b value tends to decrease with an increase in confining pressure. Thus, the b value can be used as an indicator for validating the stress concentration area, including magnitudes and accumulative probability density distribution of events, which is a beneficial complement to clarifying precursor information of rock mass instability.
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