Fracture toughness is often taken as the inherent parameter in the analysis of tearing mechanism of coated fabrics based on fracture mechanics. In this study, unique mechanical properties of coated ...fabrics, involving the orthotropic, yarn density, and nonlinear tension, are considered. Then, based on energy balance theory and Hedgepeth’s model, a theoretical expression of fracture toughness Gc in incremental format is derivated. Single-edge notched tests are conducted to obtain critical tearing strength of PVC and PTFE coated fabrics. Based on the test results, the fitting effect of different treatment methods on the nonlinear uniaxial tensile properties of two kinds of coated fabrics was studied. The corresponding fracture toughness and further predicted critical tearing strength are calculated and compared, and the critical tearing strength obtained by classical Hedgepeth’s model is also compared. The results indicate that it is important to take a full consideration of the unique properties of coated fabrics, particularly the nonlinear tensile behaviors so as to acquire reasonable fracture toughness and accurate predicted critical tearing strength. When coated fabrics, such as PTFE ones, have severe nonlinearity and crease sensitivity, nonlinearity should not be ignored. Meanwhile, using 4 segmented lines in fitting is proved to be an economical and effective processing method. This method takes nonlinearity into consideration and is convenient to carry out, which can contribute to the engineering application of the fracture toughness. The results in this work are not only applicative to the architecture field, but can be applied in a broader scope when studying the fracture toughness of coated fabrics.
•Theoretical fracture toughness of coated fabric considering nonlinearity is proposed.•Single-edge notched properties of two coated fabrics are presented.•Results obtained by three treatments fitting the nonlinearity are compared.•Fracture toughness obtained using 4 segmented lines in fitting is recommended.
Retinoblastoma is a childhood retinal tumour that is the most common primary malignant intraocular tumour. However, it has been challenging to identify the cell types associated with genetic ...complexity. Here, we performed single-cell RNA sequencing on 14,739 cells from two retinoblastoma samples to delineate the heterogeneity and the underlying mechanism of retinoblastoma progression. Using a multiresolution network-based analysis, we identified two major cell types in human retinoblastoma. Cell trajectory analysis yielded a total of 5 cell states organized into two main branches, and the cell cycle-associated cone precursors were the cells of origin of retinoblastoma that were required for initiating the differentiation and malignancy process of retinoblastoma. Tumour cells differentiation reprogramming trajectory analysis revealed that cell-type components of multiple tumour-related pathways and predominantly expressed UBE2C were associated with an activation state in the malignant progression of the tumour, providing a potential novel "switch gene" marker during early critical stages in human retinoblastoma development. Thus, our findings improve our current understanding of the mechanism of retinoblastoma progression and are potentially valuable in providing novel prognostic markers for retinoblastoma.
Background
Suid herpesvirus type 1 (SHV1) is a type of neurotropic virus able to infect various species. However, the clinical cases of human SHV1 encephalitis are still rarely reported, and the ...clinical characteristics, treatment, and prognosis of human SHV1 encephalitis are still unclear.
Methods
In this study, we reported 2 cases of human encephalitis associated with SHV1 infection and reviewed the other 18 cases from the literatures. A total of 20 cases with human SHV1 encephalitis were summarized and re-analyzed.
Results
Nineteen of 20 patients had a history of swine-related occupational exposure before illness onset. All patients initially presented with influenza-like symptoms and then developed seizures, disturbed consciousness, and endophthalmitis. All patients with clinical outcome of modified Rankin Scale of 5 or 6 suffered from rapid progressive respiratory failure. The results of cerebrospinal fluid (CSF) indicated aseptic or viral infection. MRI findings of SHV1 encephalitis were prone to distribute in temporal-frontal and insular cortex, which was similar to the pattern of herpes simplex virus encephalitis, while some cases with involvements of gray matter nuclei had a high rate of mortality. Metagenomic next-generation sequencing (mNGS) revealed that all patients had unique SHV1 sequences with variable reads in the CSF.
Conclusions
The variant SHV1 can cause a new type of human viral encephalitis, characterized by acute, fulminating, and catastrophic central nervous system infection. Rapid progressive respiratory failure and extensive lesions of deep gray matter nuclei might be indicators to poor prognosis. No approved treatments for the encephalitis are available, but it is possible to diagnose encephalitis quickly by mNGS.
The rapid rate of urbanization is causing increasing annual urban energy usage, drastic energy shortages, and pollution. Building operational energy consumption carbon emissions (BECCE) account for a ...substantial proportion of greenhouse gas emissions, crucially influencing global warming and the sustainability of urban socioeconomic development. As a foundation of building energy conservation, determination of refined statistics of BECCE is attracting increasing attention. However, reliable and accurate representation of BECCE remains lacking. This study proposed an innovative downscaling method to generate a gridded BECCE intensity benchmark dataset with 1 km2 spatial resolution. First, we calculated BECCE at the provincial level by energy balance table application. Second, on the basis of building climate demarcation, partial least squares regression models were used to establish the BECCE behavior equations for three climate regions. Third, Cubist regression models were built, retrieving down scale at the prefecture level to 1 km2 BECCE, which well-captured the complex relationships between BECCE and multisource covariates (i.e., gross domestic product, population, ground surface temperature, heating degree days, and cooling degree days). The downscaled product was verified using anthropogenic heat flux mapping at the same resolution. In comparison with other published pixel-based datasets of building energy usage, the gridded BECCE intensity map produced in this study showed good agreement and high spatial heterogeneity. This new BECCE intensity dataset could serve as a fundamental database for studies on building energy conservation and forecast carbon emissions, and could support decision makers in developing strategies for realizing the CO2 emission peak and carbon neutralization.
Thoughts of death substantially influence human behavior and psychological well-being. A large number of behavioral studies have shown evidence that asking individuals to think about death or ...mortality salience leads to significant changes of their behaviors. These findings support the well-known terror management theory to account for the psychological mechanisms of existential anxiety. However, despite increasing findings of mortality salience effects on human behavior, how the brain responds to reminders of mortality and changes the activity underlying subsequent behavior remains poorly understood. By scanning healthy adults (N = 80) of both sexes using functional magnetic resonance imaging, we showed that, relative to reading emotionally neutral sentences, reading sentences that evoke death-related thoughts decreased the salience network activity, reduced the connectivity between the cingulate cortex and other brain regions during a subsequent resting state, and dampened the speed of learning reward-related objects and cingulate responses to loss feedback during a subsequent reward learning task. In addition, the decreased resting-state cingulate connectivity mediated the association between salience network deactivations in response to reminders of mortality and suppressed cingulate responses to loss feedback. Finally, the suppressed cingulate responses to loss feedback further predicted the dampened speed of reward learning. Our findings demonstrate sequential modulations of the salience network activity by mortality salience, which provide a neural basis for understanding human behavior under mortality threat.
Tumor biomarkers are of great value in the liquid biopsy of malignant tumors. In this work, a simple and cost-friendly electrochemical aptasensor was presented for the highly sensitive and selective ...detection of glycoprotein tumor biomarkers. The DNA aptamer-modified electrode was used as the sensing interface to specifically capture the target glycoprotein tumor biomarkers, to which the alkyl halide initiators for atom transfer radical polymerization (ATRP) were then attached via the esterification crosslinking between the boronic acid group and the cis-dihydroxyl sites of the conjugated oligosaccharide chains on glycoprotein tumor biomarkers followed by the growth of long-chain polymers through electrochemically controlled ATRP (eATRP) to efficiently recruit the ferrocene detection tags. As there are tens to hundreds of cis-dihydroxyl sites on a glycoprotein tumor biomarker for attaching ATRP initiators while each long-chain polymer can recruit hundreds to thousands of ferrocene detection tags, a significantly high current signal can be generated even in the presence of ultralow-abundance targets. Hence, the eATRP-based electrochemical aptasensor is capable of sensitively and selectively detecting glycoprotein tumor biomarkers. Using alpha-fetoprotein as the model target, the limit of detection was demonstrated to be 0.32 pg/mL. Moreover, the aptasensor has been successfully applied to detect glycoprotein tumor biomarkers in human serum samples. In view of its high sensitivity and selectivity, simple operation, and cost-friendliness, the eATRP-based electrochemical aptasensor shows great promise in the glycoprotein-based liquid biopsy of malignant tumors, even at the early stage of development.
Deoxygenative transformation of ketones into value-added products often suffers from precious-metal-based catalysts or complicated operational conditions. Triflic acid and silane serve as a ...cooperative reductant to transform ketones via carbocations that undergo β-H elimination much faster than hydride transfer from silane to produce alkenes with high selectivity. Alternatively, the presence of indoles would incept the protonated ketones to generate carbocations, allowing access to Csp2–Csp3 bond formation with high reactivity and selectivity in “one pot”.
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•Proposed a strategy for developing a low-temperature oil-in-water demulsifier.•Increasing the aromaticity and polarity could enhance the effectiveness and rate of demulsifiers.•The ...role of structure and interfacial activity in demulsifiers has been discussed.•Poly (amino acids) demulsifier performs well in terms of efficiency and rate at room temperatures.
To improve the universality and efficiency of polymer demulsifiers at low temperatures, a unique type of biodegradable poly (ε-carbobenzyloxy-L-lysine) -block-poly (L-phenylalanine) (PZLL-b-PPA) demulsifier with stronger polarity and higher aromaticity was developed. The molecular structure and weight of PZLL-b-PPA were determined using Fourier transform infrared (FT-IR) spectroscopy, 1H nuclear magnetic resonance hydrogen spectra (NMR) and gel permeation chromatography (GPC). A bottle test was used to evaluate the demulsification performance of PZLL-b-PPA with different block ratios, structure and interfacial activity. Numerous critical variables, such as demulsifier structure and dosage, pH levels, emulsion salinity, oil content and oil type, were carefully examined. The demulsification results showed that PZLL5-b-PPA25 has excellent low-temperature demulsification capability and can effectively separate oil from water emulsions with different pH values (4.0 ∼ 11.0) and oil contents ranging from 1.0 ∼ 20.0 wt% within 2 min at room temperature. The best demulsification efficiency reached 99.98 %, with only 6.0 mg/L of residual oil in the separated water. The analysis of interfacial self-assembly behavior revealed that PZLL-b-PPA has a strong affinity for aromatic molecules and exhibits high interfacial activity. The quantum chemical calculation indicated that the main chain polyamide skeleton of PZLL-b-PPA has a stronger interaction for asphaltene, resin and naphthenic acid molecules than conventional oxygen-containing skeleton polymers. Furthermore, the microscopy analysis indicated that PZLL-b-PPA has excellent capacity for flocculation and coalescence of oil droplets in an O/W emulsion. As a result, when PZLL-b-PPA is added to the emulsion, it can quickly migrate to the oil-water interface and interact with and displace the emulsion's stabilizers (asphaltenes and resins), promoting oil droplet coalescence and separation from water at low temperature.
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