Search

Bilayer hydrogels composed of poly(N-isopropylacrylamide) (PNIPAm) and poly(acrylic acid-co-acrylamide) (P(AAc-co-AAm)) are commonly utilized as anisotropic hydrogels with temperature and pH sensitivity. Nonetheless, PNIPAm is known to possess poor mechanical properties, a slow thermal response, and brittleness, which greatly restricts its application for temperature sensitivity. In order to overcome these limitations, a semi-interpenetrating network (semi-IPN) structure was created by combining PNIPAm with sodium alginate. This structure effectively addressed the issue of PNIPAm’s brittleness, increased its tensile stress, and improved its tensile strain. Notably, a porogen such as sodium carbonate was incorporated to increase the porosity of the thermo-sensitive layer hydrogel, resulting in a faster thermal response rate. The bilayer hydrogel obtained can be used as a bidirectional hydrogel driver with both temperature and pH sensitivity. Mechanical manipulation through temperature changes or pH shifts can cause significant deformation in the hydrogel, making it a promising material for soft actuator applications. [ABSTRACT FROM AUTHOR]

Microbial-induced calcite precipitation (MICP) techniques are promising solutions for repairing cracks in reinforced concrete (RC) structures when exposed to a harsh chloride environment. By means of the lattice network method, this study numerically investigates the entire MICP-induced healing process from crack closure to inhibition of chloride transport of the microbial self-healing concrete by coupling the following two models: (1) the crack self-healing model; and (2) chloride diffusion model. The crack self-healing model provides visualization of the reduction of local crack widths induced by MICP. The chloride concentration distribution is quantitatively reflected through the chloride diffusion model. In addition, an empirical formula is employed to represent the relationship between diffusion coefficients of cracks in the chloride diffusion model and the time-varying crack width obtained from the crack self-healing model. The reduction of crack widths and the distribution of chloride within microbial self-healing concrete are determined through numerical calculations. The simulation reliability is validated based on comparisons with the available literature. Simulation results demonstrate that the MICP-induced crack healing effectively impedes chloride transport. [ABSTRACT FROM AUTHOR]

Noisy trapdoor claw-free function (NTCF) is a powerful post-quantum cryptographic tool that can efficiently constrain actions of untrusted quantum devices within a classical–quantum interactive cryptographic model. Although NTCF is powerful, its essence remains a 2-to-1 one-way function (NTCF 2 1 ), which is inefficient in some cryptographic tasks. This raises an intriguing question: Can NTCF be extended to higher dimensions based on standard cryptographic hardness assumptions? Inspired by the extrapolated dihedral cosets, this work focuses on developing many-to-one trapdoor claw-free functions with polynomially bounded preimage sizes. The main results can be summarized as follows: Firstly, we introduce the definition of κ -to-1 NTCF κ 1 where κ is a polynomial integer, and present an efficient construction of NTCF κ 1 assuming quantum hardness of the learning with errors (LWE) problem. Secondly, we illustrate a key application of NTCFs in establishing a reduction from the LWE problem to the dihedral coset problems (DCPs). Specifically, our approach, leveraging NTCF 2 1 (resp. NTCF κ 1 ), reveals a new quantum reduction pathway from the LWE problem to the DCP (resp. an extrapolated version of DCP). This reduction is the core cryptographic analysis tool for studying the resistance of lattice problems against quantum attacks. Finally, we demonstrate that NTCF κ 1 can be further reduced to NTCF 2 1 , thus preserving its usefulness in proofs of quantumness. [ABSTRACT FROM AUTHOR]

Scientifically validating the value of rural heritage and exploring construction wisdom has emerged as a significant challenge in the study of rural settlements worldwide. Rural heritage shows significant differences according to the natural environment, history, culture, and socio-economic factors. However, the assessment of the authenticity and effectiveness of heritage values have yet to be quantified due to the difficulty in obtaining evidence directly from samples. By constructing a multi-dimensional model of villages for quantitative analysis, we proposed a multifaceted spatial visibility analysis method based on individual and combined defense structures to empirically study the remains of eight towers in Moluo village, western China. This study demonstrated that towers serve as regional defense structures and are essential for constructing a comprehensive and effective visual defensive system (VDS) in Moluo village, a typical military defense village. The effectiveness and coverage of the towers vary depending on their location, height, type, and other factors. They form a complementary and synergistic relationship, playing a dual mechanism of public and private, local and overall defense. In summary, this method enables the feasible quantification and analysis of the functional value of rural heritage through landscape visual analysis. It provides a new perspective for studying the authenticity of heritage functions. [ABSTRACT FROM AUTHOR]

Polypropylene (PP) membrane with low porosity and poor hydrophilicity limits the performance of lithium-ion batteries. In mechanism, the function of amorphous structure of precursor film on microporous structure of PP membrane is yet unknown. In this work, the porous and hydrophilic PP/reduced hydroxyl-modified polypropylene (PPrOH) membrane was fabricated by blending esterified-PPOH firstly and then hydrolyzing to introduce the hydrogen bond in amorphous region and avoid phase separation. The results showed that the hydrogen bond was successfully introduced into the amorphous region of PP/PPrOH film and led to an increase of physical crosslinking points. Therefore, a large region of microphase separation emerged in the PP/PPrOH membrane after cold stretching, which resulted in a 45.6 % increase of porosity at maximum compared to the PP membrane. Besides, the hydrophilicity of PP/PPrOH membrane was improved with the blend content exceeding 10 wt%. Eventually, the lithium-ion conductivity of PP/PPrOH-10 membrane enhanced by 37.5 % over the base PP membrane. This work provides a novel perspective for preparing hydrophilic PP membrane with high porosity. [Display omitted] • Introducing hydrogen bond in amorphous of PP film by melt blending with PPrOH. • Hydrogen crosslinking in amorphous results in more region of microphase separation at stretching. • Addition of PPrOH increases porosity by 45.6 % and enhances lithium-ion conductivity by 37.5 % compared to PP membrane. • Crosslinking density in amorphous is positively correlated with porosity of membrane. [ABSTRACT FROM AUTHOR]

Sedimentary records indicate that subtropical and mid-latitude East Asia exhibited considerable drying and wetting, respectively, during the mid-Cretaceous, which is considered to be relevant to much higher atmospheric carbon dioxide (p CO 2) concentrations and/or proto-Tibetan Plateau (proto-TP) uplift. In order to explore and compare their roles on the East Asian climate evolution, we conducted simulations of the mid-Cretaceous climate system with different atmospheric p CO 2 levels and varying topographies. The results show that both factors had significant influences on the East Asian climate. As the increase in atmospheric p CO 2 levels from ∼560–1120 ppmv to ∼1120–2240 ppmv, the precipitation increases considerably over mid-latitude East Asia, but only small changes in the subtropical portion of East Asia occur. Simultaneously, the effects of the proto-TP uplift are opposite to those of global warming trend during that period. Generally, it leads to a precipitation decrease over subtropical East Asia, but rather minor changes over mid-latitude East Asia. These changes are qualitatively consistent with the deduction based on the geological records, but the magnitudes of the modeled precipitation changes are relatively smaller. Therefore, we can conclude that the subtropical East Asian drying during the mid-Cretaceous can be partly explained by the proto-TP uplift, while the mid-latitude East Asian wetting was partly due to global warming. However, additional factor(s) also played a significant role in the East Asian climate evolution during the mid-Cretaceous. • East Asian climate evolution was dependent on the latitude of the proto-Tibetan Plateau in the deep past; • Global warming induced wetting at mid-latitude East Asian in the mid-Cretaceous; • The proto-Tibetan Plateau uplift led to drying in the subtropical East Asian in the mid-Cretaceous. [ABSTRACT FROM AUTHOR]

This study presents atmospheric‐pressure plasma as a novel catalyst‐free pretreatment method for raw wheat straw (RWS) biomass. The work explores the effects of processing parameters, such as milled particle size, moisture content of RWS, and plasma generations, on pretreatment efficiency. To understand the mechanisms behind the enhanced pretreatment efficiency, various analysis techniques were used to analyze the physical and chemical properties of RWS before and after pretreatment. The analysis reveals that plasma pretreatment significantly damages the surface smoothness of RWS and enhances the decomposition of lignocellulosic structures. These effects are primarily attributed to the reactive species generated by the pulsed discharge, rather than the accompanying UV radiation, acidification, or heating actions during plasma pretreatment. [ABSTRACT FROM AUTHOR]

A novel mosaic structure Silica@C/Co@ZIF-67 composite was synthesized by successfully embedding Co nanoparticles on the surface of silica spheres with the help of thermoplastic polyethyleneimine by carbon-reduction. The ZIF-67 half-shell layer structure was synthesized by the in-situ growth of ZIF-67 on the surface of silica spheres through the coordination of 2-methylimidazole with Co metal nodes. The composite was used as a magnetic solid-phase extraction adsorbent combined with high performance liquid chromatography-ultraviolet detector (HPLC–UV) for the extraction and determination of benzoylurea insecticides (BUs) in vegetables and tea. Based on the presence of π-π, hydrophobic and hydrogen bonding interactions between Silica@C/Co@ZIF-67 and BUs, the BUs were rapidly captured by the composites resulting in high adsorption performance. Under the optimal extraction parameters, the linear ranges were 0.3–200 µg L−1 for diflubenzuron, 0.6–200 µg L−1 for chlorbenzuron, and 1.0–200 µg L−1 for triflumuron, teflubenzuron, and flufenoxuron, with correlation coefficients (R2) greater than 0.9991. The limits of detection (LODs) of the method were 0.1–0.3 μg L−1, and the relative standard deviations (RSDs) were 1.2–3.0% for intra-day and 2.6–4.6% for inter-day. In the spiked recovery experiments of vegetables and tea, the recoveries of the five kinds of BUs ranged from 75.8 to 112.9%. In addition, after 10 repetitions using Silica@C/Co@ZIF-67, the recoveries of the five kinds of BUs were still as high as 78.4 to 83.9%. [ABSTRACT FROM AUTHOR]

The Bangong–Nujiang Ocean played an important role in the formation of the Tibetan Plateau prior to the Cenozoic India–Eurasia collision. However, there are still uncertainties about the subduction polarity and timing of the Lhasa–Qiangtang collision. We conducted sandstone petrologic and detrital zircon U–Pb–Hf isotopic analyses on the Cretaceous Wada mélange, trench-fill strata and Duoni Formation in the Basu area in the eastern Bangong–Nujiang Suture Zone. The Wada mélange (∼114 Ma) exhibits block-within-matrix features and a detrital zircon U-Pb age spectrum characterized by multiple peaks at 114–180 Ma, 200–300 Ma, and 1800–2000 Ma. The trench-fill strata consist of coherent chert, sandstone, and mudstone, with a detrital zircon age spectrum dominated by a single peak at ∼120 Ma. The ε Hf (t) values of the 110–300 Ma detrital zircon grains in the Wada mélange and trench-fill strata range from −20 to +10 and are consistent with those of the South Qiangtang Terrane. The ε Hf (t) values of the ∼120 Ma detrital zircons are all negative, and these grains were likely derived from a remnant Cretaceous arc in the South Qiangtang Terrane to the north. These data suggest that the accretionary wedge was derived from the South Qiangtang Terrane during the northward subduction of the Bangong–Nujiang Ocean. The Duoni Formation (∼113 Ma) represents peripheral foreland basin deposits with the Lhasa Terrane as the basement. Provenance analysis indicates that these deposits received clastic material mainly from the South Qiangtang Terrane and to a lesser degree from the North Lhasa Terrane. Our results suggest that the Lhasa–Qiangtang collision occurred in the Early Cretaceous (∼113 Ma) in the eastern segment of the Bangong–Nujiang Suture Zone. • The Wada mélange and trench-fill strata (∼114 Ma) are associated with northward subduction. • The Duoni Formation (113 Ma) represents the peripheral foreland basin in the Basu area. • The eastern Bangong–Nujiang Ocean closed at ca. 113–114 Ma. [ABSTRACT FROM AUTHOR]

Although androgen deprivation therapy (ADT) by the anti-androgen drug enzalutamide (Enz) may improve the survival level of patients with castration-resistant prostate cancer (CRPC), most patients may eventually fail due to the acquired resistance. The reprogramming of glucose metabolism is one type of the paramount hallmarks of cancers. PKM2 (Pyruvate kinase isozyme typeM2) is a speed-limiting enzyme in the glycolytic mechanism, and has high expression in a variety of cancers. Emerging evidence has unveiled that microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have impact on tumor development and therapeutic efficacy by regulating PKM2 expression. Herein, we found that lncRNA SNHG3, a highly expressed lncRNA in CRPC via bioinformatics analysis, promoted the invasive ability and the Enz resistance of the PCa cells. KEGG pathway enrichment analysis indicated that glucose metabolic process was tightly correlated with lncRNA SNHG3 level, suggesting lncRNA SNHG3 may affect glucose metabolism. Indeed, glucose uptake and lactate content determinations confirmed that lncRNA SNHG3 promoted the process of glycolysis. Mechanistic dissection demonstrated that lncRNA SNHG3 facilitated the advance of CRPC by adjusting the expression of PKM2. Further explorations unraveled the role of lncRNA SNHG3 as a 'sponge' of miR-139-5p and released its binding with PKM2 mRNA, leading to PKM2 up-regulation. Together, Our studies suggest that lncRNA SNHG3 / miR-139-5p / PKM2 pathway promotes the development of CRPC via regulating glycolysis process and provides valuable insight into a novel therapeutic approach for the disordered disease. • LncRNA SNHG3 has highly expression in CRPC and promotes the process of glycolysis. • PKM2 is highly expressed in enzalutamide resistant PCa. • LncRNA SNHG3 can regulate the expression of PKM2 by sponging miR-139-5p. • lncRNA SNHG3/miRNA-139-5p/PKM2 pathway promotes the development of CRPC via regulating glycolysis process. [ABSTRACT FROM AUTHOR]

Rubberized geopolymer concrete (RuG) has become increasingly popular due to its capability of sustainable utilization of resources, but the mechanical properties of RuG could deteriorate significantly with the increase of rubber content. To mitigate the adverse effects of rubber and further promote the engineering applications of eco-friendly building materials, a new type of composite column, i.e., steel tubed rubberized geopolymer concrete (ST-RuG) columns, was proposed and tested in this paper. The influence of concrete types, rubber replacement ratios, the configurations of steel tubes, and diameter-to-thickness ratios on the compressive behavior of specimens was analyzed. The test results show that the incorporation of rubber has a deterioration effect on the strength of ST-RuG columns with a maximum degradation of 37.6%, but it can improve the ductility of specimens to a certain extent, which is slightly superior to steel tubed rubberized ordinary concrete (ST-RuO) columns. Due to the inherent brittleness of geopolymer concrete (GPC), more obvious residual behavior is detected for ST-RuG compared with ST-RuO under the same rubber replacement ratio R f. Moreover, with the increase of R f , the confining pressure of ST-RuG specimens gradually decreases, and a significant decreasing trend is observed for both the peak stress ratio and residual strength ratio of confined RuG. Finally, a new stress-strain model considering the effect of rubber replacement ratio is developed, and comparisons with test results reveal that the proposed model possesses satisfactory accuracy in predicting the axial stress-strain curves of steel-confined GPC and RuG. • The axial compressive behavior of steel tubed rubberized geopolymer concrete columns was investigated. • The effects of key test parameters on the interaction mechanism of specimens were explored. • A new stress-strain model considering the effect of rubber particles was developed for steel tubed geopolymer concrete. [ABSTRACT FROM AUTHOR]

To alleviate the consumption of resources and promote the further application of geopolymer concrete in practical engineering, the mechanical performance of steel tubed geopolymer concrete (STGC) columns under axial compression was first explored in this study. The impact of experimental parameters including concrete types, configurations of steel tubes, diameter-to-thickness ratios (D / t), and slag contents were analyzed in detail. The test results illustrate that after grooving at the two ends of columns, the axial deformation of the external steel tube becomes smaller compared with the core concrete and the confining pressure of the external steel tube is improved significantly, resulting in a remarkable improvement of the compressive strength and corresponding strain at both peak and residual state of the specimens. Although little influence of concrete types on the steel stress evaluation is detected, the ductility of the STGC columns is inferior to that of the specimens with ordinary concrete due to the obvious brittle property of geopolymer concrete. Moreover, the ratio of axial stress to yield strength of the external steel tube at the peak load of STGC columns is increased with the decrease of diameter-to-thickness ratio and concrete strength. Finally, a new model for predicting the steel axial stress in steel tubed concrete (STC) columns at the peak state is established and a load capacity model incorporating the steel axial contribution is also developed for STC columns. Compared with extensive existing test results, the developed model can provide satisfactory accuracy. • Axial compressive behavior of steel tubed geopolymer concrete columns was investigated. • Effects of key test parameters on the interaction mechanism of the composite columns were analyzed. • The axial stress model of steel tube at the peak state of STC columns is proposed. • The load capacity model incorporating the axial contribution of the steel tube is developed for STC columns. [ABSTRACT FROM AUTHOR]