Search

Heat treatment reduces the quality of Antarctic krill (Euphausia superba) meat, thus greatly limiting its industrial application. It was found that L-Lys immersion pretreatment can effectively improve the quality of heat-treated Antarctic krill meat; the underlying mechanism is unclear. Therefore, this study aimed to investigate the effect of L-Lys concentrations (0, 25, 50, 100, and 200 mM) on the aggregation behavior and structure of Antarctic krill myofibrillar protein solution before and after heat treatment. Compared with the untreated group, L-Lys decreased the surface hydrophobicity and particle size of the heat-treated Antarctic krill protein by 2.38 times and 18.27 times while increasing the solubility by 3.59 times. Furthermore, L-Lys intervention inhibited the formation of disulfide bonds in myofibrillar protein of the heat-treated Antarctic krill, enhanced the intermolecular hydrogen bonding force, improved the orderliness of the secondary structure, and "exposed" the tyrosine residues of the protein molecule. As a result, the polarity of the microenvironment was enhanced while the tertiary structure of the protein was altered, thus inhibiting thermal aggregation. This study reveals the mechanism of L-Lys inhibition of thermal aggregation behavior of Antarctic krill myofibrillar protein. Our results provide insights into the development and utilization of Antarctic krill protein in the food industry. [ABSTRACT FROM AUTHOR]

The analysis of rainwater infiltration is crucial for the prevention and early detection of rainfall-induced landslides. Under the assumption of saturated-unsaturated stratification, and considering the influence of saturated layer seepage and air pressure on infiltration, a modified Green-Ampt model (SRGA model) suitable for slope rainfall infiltration is established. A corresponding slope safety factor expression is derived for the model. The results show that the SRGA is demonstrated to accurately describe dynamic expansion of the wetting layer throughout the heavy rainfall infiltration process; it is also applicable under weaker rainfall conditions. Validation against experimental data confirms the model's accuracy, with an error of approximately 21% compared to Chen-Young's model. The instability time predicted with the SRGA model during the slope stability analysis emerges approximately 7.2% earlier than measured, significantly outperforming Chen-Young's model. Air pressure and seepage force influence infiltration depth through different mechanisms. The influence of air pressure is more significant in the early control stage of soil infiltration capacity, while seepage force is more significant in the later stage. Rainfall infiltration is affected by slope length to greater extent than slope stability. The SRGA model is versatile, and can be simplified into existing models under certain conditions. The results of this work may provide theoretical support for slope control under rainfall infiltration conditions. [ABSTRACT FROM AUTHOR]

To better understand the geodynamic evolution of northeastern China during the Late Mesozoic, we analyzed zircon U–Pb geochronological, Lu–Hf isotopic, and geochemical data for Early Cretaceous volcanic rocks from the southeastern margin of the Songliao Basin. Newly identified A-type rhyolite and trachyandesite yielded zircon 206Pb/238U ages of ca. 123 Ma and 117 Ma, respectively. The rhyolites are high in SiO2 (72.24–78.89 wt%) and total alkali (K2O + Na2O = 8.81–10.03 wt%), and low in MgO (0.10–0.26 wt%), CaO (0.32–0.36 wt%), Ni (0.08–2.69 ppm), and Cr (0.39–4.87 ppm) concentrations, with negative Nb, Ta, and Sr anomalies. They are enriched in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) and depleted in high-field-strength elements (HFSEs); the calculated Zr saturation temperatures are high (828–915 °C). The A-type rhyolites possess variable zircon εHf(t) values ranging from + 5.69 to + 10.49. Petrogenetic analysis leads us to propose that the A-type rhyolites were probably formed by partial melting of a Neoproterozoic–Early Paleozoic juvenile lower crust. The trachyandesites have Nb/Ta (14.9–17.25), Zr/Hf (35.04–42.75), Rb/Sr (0.25–0.40), and Lu/Yb (0.14–0.15) ratios that are similar to those of mantle-derived magma, indicating a mantle source. They have εHf(t) values of + 4.71 to + 7.29 and show enrichment in LILEs and LREEs, and weak depletion in HFSEs, suggesting that the parent magma originated from partial melting of a depleted lithospheric mantle, and was subsequently metasomatized by subduction-related fluids, followed by extensive fractional crystallization during the magma evolution. Combined with the temporal and spatial distribution of Late Mesozoic igneous rocks from the southeastern margin of the Songliao Basin, we propose that Early Cretaceous volcanic rocks formed in an extensional tectonic setting that was closely related to rollback of the Paleo-Pacific (Izanagi) oceanic slab. [ABSTRACT FROM AUTHOR]

The perplexing issues related to positive surgical margins and the considerable negative consequences associated with systemic chemotherapy have posed ongoing challenges for clinicians, especially when it comes to addressing bladder cancer treatment. The current investigation describes the production of nanocomposites loaded with gemcitabine (GEM) and cisplatin (CDDP) through the utilization of electrospinning technology. In vitro and in vivo studies have provided evidence of the strong effectiveness in suppressing tumor advancement while simultaneously reducing the accumulation of chemotherapy drugs within liver and kidney tissues. Mechanically, the GEM and CDDP-loaded electrospun nanocomposites could effectively eliminate myeloid-derived suppressor cells (MDSCs) in tumor tissues, and recruit CD8+ T cells and NKp46+ NK cells to kill tumor cells, which can also effectively inhibit tumor microvascular formation. Our investigation into the impact of localized administration of chemotherapy through GEM and CDDP-loaded electrospun nanocomposites on the tumor microenvironment will offer novel insights for tackling tumors. [ABSTRACT FROM AUTHOR]

This article theorises the local world as a conceptual scaffold for future conservation and regeneration. It aims to catalyse a theoretical dialogue across the East and West to understand how ordinary places and lifeworlds are preserved, reproduced, and possibly reimagined. The local worlds discussed herein are conceptualised as the worlds of many, the worlds of relating, the worlds of structuring and the worlds of becoming. These four cardinal points present a source of open-endedness and futurity for contemporary architectural reinterpretation. The current article examines the characterisation of the Wen village conservation and regeneration project, led by the Amateur Architecture Studio in Zhejiang Province of China (2012–2016), as an architectural reimagination of local worlds, with a strong sensitivity to the ordinary places and lifeworlds of rural China and juxtapositions of new local worlds within old worlds. By piecing together the flows and fragments of the architectural process, this article shows how locally situated designs and dynamics have shaped the project in both its formation and afterlife, both ethically and contemporarily. Using close readings of popular and oral accounts from both architect's and users' perspectives, this article extends the case study by broadening theoretical conversations about contemporary architecture's capacity to reimagine local worlds. [ABSTRACT FROM AUTHOR]

Purpose: Tumor stem cells have emerged as a crucial focus of investigation and a therapeutic target in the context of cancer metastasis and drug resistance. They represent a promising novel approach to address the treatment of uveal melanoma (UVM). Methods: According to the one-class logistic regression (OCLR) approach, we first estimated two stemness indices (mDNAsi and mRNAsi) in a cohort of UVM (n = 80). The prognostic value of stemness indices among four subtypes of UVM (subtype A–D) was investigated. Moreover, univariate Cox regression and Lasso-penalized algorithms were conducted to identify a stemness-associated signature and verify in several independent cohorts. Besides, UVM patients classified into subgroups based on the stemness-associated signature. The differences in clinical outcomes, tumor microenvironment, and probability of immunotherapeutic response were investigated further. Results: We observed that mDNAsi was significantly linked with overall survival (OS) time of UVM, but no association was discovered between mRNAsi and OS. Stratification analysis indicated that the prognostic value of mDNAsi was only limited in subtype D of UVM. Besides, we established and verified a prognostic stemness-associated gene signature which can classify UVM patients into subgroups with distinct clinical outcomes, tumor mutation, immune microenvironment, and molecular pathways. The high risk of UVM is more sensitive to immunotherapy. Finally, a well-performed nomogram was constructed to predict the mortality of UVM patients. Conclusions: This study offers a comprehensive examination of UVM stemness characteristics. We discovered mDNAsi-associated signatures improved the prediction capacity of individualized UVM prognosis and indicated prospective targets for stemness-regulated immunotherapy. Analysis of the interaction between stemness and tumor microenvironment may shed light on combinational treatment that targets both stem cell and the tumor microenvironment. [ABSTRACT FROM AUTHOR]

The present study sought to evaluate the effect of basic amino acid (L-arginine (Arg), L-lysine (Lys), and L-histidine (His)) pretreatment on the quality of canned Antarctic krill. Additionally, the changes in krill meat at different pretreatment conditions and processing stages were measured. The Lys-pretreated krill meat exhibited 39.9% lower hardness, 19.8% lower chewiness, and 47.2% lower thiobarbituric acid reaction substances (TBARS) compared to the control group. The low-field nuclear magnetic resonance (LF-NMR) and the magnetic resonance imaging (MRI) analyses revealed that the Lys-pretreated krill meat showed a larger peak area of immobile water and a higher pseudo-color image brightness. The scanning electron microscopy (SEM) results showed that the microstructure of krill meat in the control group was broken and disordered, while the microstructural network of Lys-pretreated krill meat was more complete. This result indicated that Lys effectively improved the texture, water-holding capacity, and color of krill meat, protecting the microstructure and reducing the degree of oxidation. The sensory evaluation results showed that the Lys-treated canned Antarctic krill had a better flavor and texture than other canned products. Overall, Lys could be a potential regulatory strategy for effectively enhancing the quality of canned Antarctic krill. [ABSTRACT FROM AUTHOR]

Dynamic processes that occur on the edge of complex networks are relevant to a variety of real-world systems, where states are defined on individual edges, and nodes are active components with information processing capabilities. In traditional studies of edge controllability, all adjacent edge states are assumed to be coupled. In this paper, we release this all-to-all coupling restriction and propose a general edge dynamics model. We give a theoretical framework to study the structural controllability of the general edge dynamics and find that the set of driver nodes for edge controllability is unique and determined by the local information of nodes. Applying our framework to a large number of model and real networks, we find that there exist lower and upper bounds of edge controllability, which are determined by the coupling density, where the coupling density is the proportion of adjacent edge states that are coupled. Then we investigate the proportion of effective coupling in edge controllability and find that homogeneous and relatively sparse networks have a higher proportion, and that the proportion is mainly determined by degree distribution. Finally, we analyze the role of edges in edge controllability and find that it is largely encoded by the coupling density and degree distribution, and are influenced by in- and out-degree correlation. [ABSTRACT FROM AUTHOR]

Achieving hydrogen production and simultaneous decomposition of organic pollutants through dual-functional photocatalytic reactions has received increasing attention due to the environmentally friendly and cost-effective characteristics of this approach. In this work, an urchin-like oxygen-doped MoS2/ZnIn2S4 (OMS/ZIS) composite was fabricated for the first time using a simple solvothermal method. The unique microstructure with abundant active sites and fast charge transfer channels further shortened the charge migration distance and compressed carrier recombination. The obtained composite exhibited an efficient H2 evolution reaction rate of 12.8 mmol/g/h under visible light, which was nearly times higher than pristine ZnIn2S4, and the apparent quantum efficiency was 14.9% (420 nm). The results of the simultaneous photocatalytic H2 evolution and organic pollutant decomposition test were satisfactory, resulting in decomposition efficiencies of resorcinol, tetracycline, and bisphenol A that reached 41.5%, 63.5%, and 53.0% after 4 h, respectively, and the highest H2 evolution rate was 672.7 µmol/g/h for bisphenol A. Furthermore, natural organic matter (NOM) abundantly found in actual water was adopted as an electron donor for H production under simulated sunlight irradiation, indicating the promising practicability of simultaneous hydrogen evolution and NOM decomposition. Moreover, the mechanisms of the dual-purpose photocatalytic reactions, as well as the synergistic effect between the molecular structures of the organic pollutants and the corresponding adsorption behavior on the photocatalyst surface were illustrated in detail. These obtained results may serve as an inspiration for the rational design of highly efficient, dual-functional photocatalysts in the future. [ABSTRACT FROM AUTHOR]

Antarctic krill (Euphausia superba) is an important source of biomass and high-quality protein. However, heat treatment negatively impacts the quality of Antarctic krill and compromises its utilization in the food industry. This study aimed to investigate the mechanisms underlying changes in Antarctic krill meat characteristics and physicochemical properties treated at different temperatures and holding times. Our findings indicated that hardness and cooking loss of Antarctic krill meat increased dramatically at higher temperatures and holding times. The low-field nuclear magnetic resonance (LF-NMR) analysis revealed that the loss of immobilized water increased, whereas the SDS-PAGE analysis showed that the content of myosin heavy chain decreased significantly and that protein degradation occurred. Fourier transform infrared spectroscopy (FT-IR) and intrinsic fluorescence spectra suggested that α-helix motifs were transformed into β-sheets and that more hydrophobic groups were exposed. The scanning electron microscopy (SEM) results showed that Antarctic krill meat formed corrugated folded regions after heat treatment without forming a three-dimensional water-entrapped structure, which led to significant water loss, resulting in rapid deterioration of Antarctic krill meat. These results provide the basis for a deeper understanding of the processing characteristics of Antarctic krill meat. [ABSTRACT FROM AUTHOR]

The dissolution rate and development trend of karst tunnel surrounding rock can strongly affect tunnel stability. This study analyzes the influence of tunnel construction on the engineering geological conditions of surrounding rock, taking the Ehan expressway as the research object. Geological conditions of surrounding rock were obtained through on-site geological survey and geophysical exploration methods. The geological conditions of the surrounding rock are reconstructed, dissolution experiments are carried out, and the tunnel stability during the operation period is evaluated. The results indicate that tunnel construction alters the engineering geological conditions of the surrounding rock, provides good conditions for karst development, and increases the safety risk throughout the entire tunnel life cycle. Limestone and marl exhibit the same dissolution behavior, but the dissolution-sensitive factors and karst development trend differ. Limestone is more sensitive to chemical erosion, whereas marl is more sensitive to the mechanical erosion of water flow. The development of karst fractures is generally uneven in limestone, whereas karst fractures develop more regularly in marl. The failure probability of surrounding rock increases slowly when the fracture trace length of surrounding rock is small, but increases significantly when the fracture trace length is long. Higher dissolution rates are associated with greater surrounding rock failure probability. During the preliminary design of tunnels with strong karst development, it is necessary to reconstruct the engineering geological conditions throughout the entire life cycle, perform safety evaluations, prepare safety reserves in advance, and take preventive measures prior to construction and operation to effectively minimize the impact of karst development on the tunnel structure. [ABSTRACT FROM AUTHOR]

Macrocyclization is an important process that affords morphed scaffold in biosynthesis of bioactive natural products. Nature has adapted diverse biosynthetic strategies to form macrocycles. In this work, we report the identification and characterization of a small enzyme AvmM that can catalyze the construction of a 16-membered macrocyclic ring in the biosynthesis of alchivemycin A (1). We show through in vivo gene deletion, in vitro biochemical assay and isotope labelling experiments that AvmM catalyzes tandem dehydration and Michael-type addition to generate the core scaffold of 1. Mechanistic studies by crystallography, DFT calculations and MD simulations of AvmM reveal that the reactions are achieved with assistance from the special tenuazonic acid like moiety of substrate. Our results thus uncover an uncharacterized macrocyclization strategy in natural product biosynthesis. Macrocyclization is an important process in bioactive natural product synthesis. Here, the authors report on the study of a macrocyclic ring constructing enzyme in the biosynthesis of alchivemycin A and using gene deletion, biochemical assays and isotope labelling show the enzyme catalyses tandem dehydration and Michael-type addition. [ABSTRACT FROM AUTHOR]

Background: Mitochondrial complex I deficiency (MCID) is the most common biochemical defect identified in childhood with mitochondrial diseases, mainly including Leigh syndrome, encephalopathy, macrocephaly with progressive leukodystrophy, hypertrophic cardiomyopathy and myopathy. Objective: To identify genetic cause in a patient with early onset autosomal recessive MCID. Methods: Trio whole-exome sequencing was performed and phenotype-related data analyses were conducted. All candidate mutations were confirmed by Sanger sequencing. Results: Here we report a child of Leigh syndrome presented with global developmental delay, progressive muscular hypotonia and myocardial damage. A missense mutation c.118C > T (p.Arg40Trp) and a previously reported mutation c.1157G > A (p.Arg386His) in NDUFV1 have been identified as compound heterozygous in the patient. The mutation p.Arg386His is closely associated with the impairment of 4Fe-4S domain and this mutation has been reported pathogenic. The c.118C > T mutation has not been reported in ClinVar and HGMD database. In silico protein analyses showed that p.Arg40 is highly conserved in a wide range of species, and the amino acid substitution p.Trp40 largely decreases the stability of NDUFV1. In addition, the mutation has not been detected in the Asian populations and it was predicted to be deleterious by numerous prediction tools. Conclusion: This research expands the mutation spectrum of NDUFV1 and substantially provides an early and accurate diagnosis basis of MCID, which would benefit subsequently effective genetic counseling and prenatal diagnosis for future reproduction of the family. [ABSTRACT FROM AUTHOR]

Circ-Memo1 has been proved to be upregulated in ischemia–reperfusion induced acute injury of kidney tissues. However, the potential role of circ-Memo1 in cerebral hypoxia/reoxygenation (H/R) injury is still unclear. Blood samples were collected from 25 ischemic stroke patients and 25 healthy controls. To construct the H/R model, human brain microvascular endothelial cells (HBMVECs) were cultured under the hypoxic condition, followed by reoxygenation. Cell viability was analyzed by MTT assay. Flow cytometry was carried out to examine cell apoptosis. The level of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were measured by MDA and SOD assay kits, respectively. The levels of TNF-α, IL-1β, and IL-6 were determined by enzyme-linked immunosorbent assay (ELISA). Dual-luciferase reporter gene detection was employed to verify the binding relationships between circ-Memo1, miR-17-5p, and SOS1. Circ-Memo1 and SOS1 expressions were increased, and miR-17-5p expression was reduced in ischemic stroke patients. Circ-Memo1 silencing promoted cell viability, inhibited the activation of ERK/NF-κB signaling pathway, reduced oxidative stress and inflammatory response, and inhibited cell apoptosis. Moreover, miR-17-5p functioned as the sponge of circ-Memo1, and SOS1 was identified as the target of miR-17-5p. The protective effect of circ-Memo1 knockdown on cell injury after H/R treatment was weakened by miR-17-5p inhibition. Knockdown of circ-Memo1 alleviated H/R injury of HBMVEC cells by regulating the miR-17-5p/SOS1 axis, indicating that circ-Memo1 might be a potential treatment target for cerebral H/R injury. [ABSTRACT FROM AUTHOR]

Background: Recent studies revealed that long non-coding RNAs (lncRNAs) have significant roles in regulating the pathogenesis of ischemia stroke, and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced cell apoptosis. Aberrant expression of NEAT1 was found after the injury of ischemia-reperfusion, but the mechanism was not fully understood. Methods: The expression of NEAT1 and Mfn2 were detected in BV-2 and N2a cell with or without OGD/R-induced by qRT-PCR. Inflammatory cytokines secretion was detected by enzyme-linked immunosorbent assay (ELISA). The oxidative stress was evaluated by the examination of ROS, MDA and SOD levels. Flow cytometry and apoptosis marker detection by western blot were performed to examined apoptosis. Results: The expression of NEAT1 and Mfn2 were decreased in OGD/R-induced cell model. Overexpression of NEAT1 or Mfn2 reduced oxidative stress and apoptosis by OGD/R-induced in neuronal cells, while knockdown of Sirt3 reversed the protective effect of NEAT1 and Mfn2. NEAT1 stabilized Mfn2 mRNA via recruiting Nova. NEAT1 alleviates the oxidative stress and apoptosis by OGD/R-induced via activating Sirt3. Conclusion: LncRNA NEAT1 stabilizes Mfn2 mRNA via recruiting Nova, therefore increase the expression of Mfn2 and alleviates ischemia-reperfusion induced oxidative stress and apoptosis via Mfn2/Sirt3 pathway. [ABSTRACT FROM AUTHOR]

Here, we systematically investigate the chemical process of low-temperature catalytic graphitization of polyacrylonitrile (PAN) by using roughened copper (Cu) nanostructures as a plasmonic photocatalyst. Our in situ surface-enhanced Raman scattering spectroscopy (SERS) results show that the PAN coated on the Cu surface is successfully converted to graphite at 120 °C. The gradual increase of radiation power in the SERS leads to a significant reduction of the number of defects formed in the graphite, which will not be caused by employing longer duration laser. Moreover, when the average size of the copper nanostructures is about 40 nm, the PAN has the largest graphitization degree. In order to simulate the impact of the different Cu nanostructure sizes on the local electric field distribution, we performed a self-consistent numerical model calculation (finite-difference time-domain, FDTD). The calculated results show that the local electric field distribution presents a strong dependence on the size of the Cu-based nanostructures. The experimental results are in direct line with the assumption that the excitation on plasmonic nanostructures results in increased generation rates of hot carriers due to the local electric field enhancement. [ABSTRACT FROM AUTHOR]

Spinal muscular atrophy (SMA), a degenerative motor neuron disease and a leading cause of infant mortality, is caused by loss of functional survival motor neuron (SMN) protein due to SMN1 gene mutation. Here, using mouse and cell models for behavioral and histological studies, we found that SENP2 (SUMO/sentrin-specific protease 2)-deficient mice developed a notable SMA-like pathology phenotype with significantly decreased muscle fibers and motor neurons. At the molecular level, SENP2 deficiency in mice did not affect transcription but decreased SMN protein levels by promoting the SUMOylation of SMN. SMN was modified by SUMO2 with the E3 PIAS2α and deconjugated by SENP2. SUMOylation of SMN accelerated its degradation by the ubiquitin–proteasome degradation pathway with the ubiquitin E1 UBA1 (ubiquitin-like modifier activating enzyme 1) and E3 ITCH. SUMOylation of SMN increased its acetylation to inhibit the formation of Cajal bodies (CBs). These results showed that SENP2 deficiency induced hyper-SUMOylation of the SMN protein, which further affected the stability and functions of the SMN protein, eventually leading to the SMA-like phenotype. Thus, we uncovered the important roles for hyper-SUMOylation of SMN induced by SENP2 deficiency in motor neurons and provided a novel targeted therapeutic strategy for SMA. Key messages: SENP2 deficiency enhanced the hyper-SUMOylation of SMN and promoted the degradation of SMN by the ubiquitin–proteasome pathway. SUMOylation increased the acetylation of SMN to inhibit CB formation. SENP2 deficiency caused hyper-SUMOylation of SMN protein, which further affected the stability and functions of SMN protein and eventually led to the occurrence of SMA-like pathology. [ABSTRACT FROM AUTHOR]

Social-local-mobile (SoLoMo) service integrates social network services and location-based services via mobile devices to fulfill user requirements. However, while using SoLoMo services, users need to disclose personal information. The potential consequences to the users, when such sensitive information is exposed in different scenarios, are ambiguous. In this study, privacy regulation theory and multidimensional developmental theory of privacy were applied, and scenario-based experiments were conducted to understand the users' trust, service quality, and privacy concerns. The results reveal that the experiences of victims of privacy leaks or social embarrassment would lead to decreased trust and service quality, and heighten privacy concerns. [ABSTRACT FROM AUTHOR]

There have been many railway construction projects in the loess region of China. Embankment is typically required for rail projects in these regions, since the railway basement is restricted by longitudinal slope requirements. However, there has been little study of the dynamic response of compacted loess embankment under moving train loading. The 2.5D finite element method was adopted to investigate this process and characterize the effects of train speed, height of embankment, and axle weight on the dynamic behavior of subgrade. A rectangular core zone of subgrade was determined, and a prediction model was established to evaluate the long-term settlement of embankment generated by moving train loading. The results showed that embankment height had negligible influence on the variation of dynamic stress. Decays of stress amplitude in both the vertical and horizontal directions slowed with increased train speed. Additionally, the dynamic stress increased linearly with the increase in axle weight due to the linear stress-strain relationship of soil. In the practical speed range (≤ 100 m/s), the dynamic influence depth increased with increasing speed in a range of 3–6 m. A core zone depth of 6 m reflects the effects of moving train loading, with a width of 4 m. For practical conditions (v ≤ 100 m/s), only slight settlement of embankment was observed (≤ 6 mm). However, it is difficult to achieve the same physical parameters used in the experiments (moisture content and compaction degree) in engineering practice. Further work should explore long-term dynamic settlement with relation to the degree of compaction of the embankment. [ABSTRACT FROM AUTHOR]

Climate change in permafrost regions has caused frost heave and thawing settlement of soil around piles, inducing bridge engineering damage. Herein, the solid-to-liquid ratio is used as a hydrothermal coupling term and the frost heave ratio is introduced to establish a pile–soil system frost heave and thawing settlement model. An indoor physical model test is used to confirm the calculation model's correctness. Based on the investigation data of the No. 16 pile of the Chalabing Bridge on the Qinghai–Tibet Plateau, studies on soil temperature and moisture fields as well as frost heave and thawing settlement of the pile–soil system were conducted through the secondary development of partial differential equation (PDE) module in the COMSOL software package. Results show that the permafrost table will degrade from − 3.2 to − 4.9 m with an atmospheric temperature increase of 2.6 °C in the next 50 years. The migration of water to the pile side will increase. Moreover, the thawing settlement amount on the pile side will gradually increase with increasing atmospheric temperature, and the maximum thawing settlement amounts on the pile side in years 1, 10, 30, and 50 will be 4.95, 7.63, 11.58, and 13.66 mm, respectively. Similarly, the frost heave amount will gradually decrease with increasing atmospheric temperature, and the frost heave amounts on the pile side for years 1, 10, 30, and 50 will be 6.66, 5.51, 3.99, and 3.69 mm, respectively. For the stability of pile foundation engineering in permafrost regions in the future, the prevention and control of thawing settlement should be focused. [ABSTRACT FROM AUTHOR]

Nationwide prospective surveillance of all-age patients with acute respiratory infections was conducted in China between 2009‒2019. Here we report the etiological and epidemiological features of the 231,107 eligible patients enrolled in this analysis. Children <5 years old and school-age children have the highest viral positivity rate (46.9%) and bacterial positivity rate (30.9%). Influenza virus, respiratory syncytial virus and human rhinovirus are the three leading viral pathogens with proportions of 28.5%, 16.8% and 16.7%, and Streptococcus pneumoniae, Mycoplasma pneumoniae and Klebsiella pneumoniae are the three leading bacterial pathogens (29.9%, 18.6% and 15.8%). Negative interactions between viruses and positive interactions between viral and bacterial pathogens are common. A Join-Point analysis reveals the age-specific positivity rate and how this varied for individual pathogens. These data indicate that differential priorities for diagnosis, prevention and control should be highlighted in terms of acute respiratory tract infection patients' demography, geographic locations and season of illness in China. China operates a national surveillance program for acute respiratory infections and sampled over 200,000 patients between 2009–2019. Here, the authors present results from this program and describe patterns by age, pathogen type, presence of pneumonia, and season. [ABSTRACT FROM AUTHOR]

A photoelectrochemical (PEC) biosensor capable of detecting cytokeratin 19 fragment 21-1 (CYFRA21-1) was optimized by taking advantage of the powerful conjugate repeats of horseradish peroxidase and tyramine (HRP-tyramine)–triggered enzymatic biocatalytic precipitation (BCP) on high-performance BiVO4/Ag3VO4/SnS2 photoelectrodes. Compared with the ubiquitous BCP strategy, we identified a design supporting conjugate repeats generated by HRP and tyramine–triggered immeasurable insoluble precipitates in the presence of hydrogen peroxide and 4-chloro-1-phenol (4-CN), and the steric hindrance improved sensitivity. Moreover, by virtue of BiVO4, Ag3VO4, SnS2 excellent level matching structure and chemical stability, a heterojunction (BiVO4/Ag3VO4/SnS2) with high light absorption efficiency has been successfully prepared. The novel heterostructure system of BiVO4/Ag3VO4/SnS2 with high detection current and low background signal exhibited high-performance PEC determination. Generally, the hitherto untapped biosensor resource realized the sensitive detection of CYFRA21-1 with a wide linear range from 50 fg/mL to 200 ng/mL, and a detection limit of 15 fg/mL, which illustrated the potential for biotechnological applications. [ABSTRACT FROM AUTHOR]

This work studies the dynamic responses of bearing-supported pedestrian bridges with Y-shaped piers and various deck widths under harmonic ground motions. To fulfill the immediate occupancy performance objective, the dynamic responses of bridges with linear or nonlinear viscous dampers are evaluated by performing nonlinear time-history analyses. The results show that the maximum transverse displacements of girder and pier top in original bridges are closely dependent on the characteristic period of ground motion. The installation of linear viscous dampers between steel girder and Y-shaped piers can effectively improve the seismic performance of bridges and hence reduce the corresponding shear demand of bearings. Further parametric studies show that, with optimal damping coefficient and velocity exponent, the seismic performances of bridges with viscous dampers can be insensitive to the characteristic period of ground motion. [ABSTRACT FROM AUTHOR]

Pile cutting behavior has been frequently applied in complex underground space development projects; however, few studies have paid attention to the influence of cutting partial pile on the load transfer trend of supporting structure. In this study, considering a deep foundation pit in Xi'an as an example, a three-dimensional numerical model was established to analyze the redistribution of soil pressure in the foundation pit and the variation of the stress of supporting structure under the condition of partial pile cutting, and the qualitative verification was made by using the field measured data. The results show that the earth pressure redistribution behind the pile is caused by the cutting pile, and the redistribution range and trend of the earth pressure are different at different depths. After the supporting pile is cut, the stress modes of the upper and lower parts of the broken pile are different and the axial force of the anchor decreases. Moreover, the anchor and supporting pile in the adjacent cut pile area exhibit an obvious loading effect, and the bending moment and shear force of the crown beam increase significantly. Notably, the greater the excavation depth, the lower the ability of the foundation pit supporting structures to resist damage. The research results may provide a theoretical basis and practical experience for the construction of similar projects in the future. [ABSTRACT FROM AUTHOR]

National-based prospective surveillance of all-age patients with acute diarrhea was conducted in China between 2009‒2018. Here we report the etiological, epidemiological, and clinical features of the 152,792 eligible patients enrolled in this analysis. Rotavirus A and norovirus are the two leading viral pathogens detected in the patients, followed by adenovirus and astrovirus. Diarrheagenic Escherichia coli and nontyphoidal Salmonella are the two leading bacterial pathogens, followed by Shigella and Vibrio parahaemolyticus. Patients aged <5 years had higher overall positive rate of viral pathogens, while bacterial pathogens were more common in patients aged 18‒45 years. A joinpoint analysis revealed the age-specific positivity rate and how this varied for individual pathogens. Our findings fill crucial gaps of how the distributions of enteropathogens change across China in patients with diarrhea. This allows enhanced identification of the predominant diarrheal pathogen candidates for diagnosis in clinical practice and more targeted application of prevention and control measures. Diarrhoea is a major cause of morbidity and mortality in China. Here, the authors present results from a large sentinel surveillance scheme from 217 hospitals in all 31 provinces in mainland China, including ~150,000 patients with acute diarrhoea and covering years 2009-2018. [ABSTRACT FROM AUTHOR]

Streptoseomycin (STM, 1) is a bacterial macrolactone that has a unique 5/14/10/6/6-pentacyclic ring with an ether bridge. We have previously identified the biosynthetic gene cluster for 1 and characterized StmD as [6 + 4]- and [4 + 2]-bispericyclase that catalyze a reaction leading to both 6/10/6- and 10/6/6-tricyclic adducts (6 and 7). The remaining steps, especially how to install and stabilize the required 10/6/6-tricyclic core for downstream modifications, remain unknown. In this work, we have identified three oxidoreductases that fix the required 10/6/6-tryciclic core. A pair of flavin-dependent oxidoreductases, StmO1 and StmO2, catalyze the direct hydroxylation at [6 + 4]-adduct (6). Subsequently, a spontaneous [3,3]-Cope rearrangement and an enol-ketone tautomerization result in the formation of 10/6/6-tricyclic intermediate 12b, which can be further converted to a stable 10/6/6-tricyclic alcohol 11 through a ketoreduction by StmK. Crystal structure of the heterodimeric complex NtfO1-NtfO2, homologues of StmO1-StmO2 with equivalent function, reveals protein-protein interactions. Our results demonstrate that the [6 + 4]-adduct instead of [4 + 2]-adduct is the bona fide biosynthetic intermediate. Streptoseomycin is a potent antibiotic that contains a pentacyclic 5/14/10/6/6 ring system. Here, the authors report the enzymatic and non-enzymatic steps of the downstream modification of streptoseomycin biosynthesis and show a [6 + 4]-cycloaddition adduct as an unexpected biosynthetic intermediate. [ABSTRACT FROM AUTHOR]

A novel electron donor controlled-release system is proposed based on liposome encapsulated L-cysteine for the sensitive determination of cytokeratin 19 fragment 21–1 (CYFRA 21-1). On the one hand, a defective TiO2 modified with methylene blue was employed as a photoactive platform which exhibited a high photoelectrochemical (PEC) response owing to the introduction of oxygen vacancies and the high photosensitivity of the dye. On the other hand, L-cysteine as the sacrificial electron donor was encapsulated in the vesicles of liposomes, and this composite was used as the signal amplification factor, which is labeled on the secondary antibody of CYFRA 21-1 to further improve the photocurrent sensitivity. The excellent electron transfer path in photoactive materials coupled with the skilful electron donor controlled-release system, contributed to the sensitive PEC analysis of CYFRA 21-1 underoptimum conditions. The PEC immunoassay showed a linear current response in the range 0.0001–100 ng/mL with a detection limitof 37 fg/mL. Enhanced stability and satisfactory reproducibility were also achieved. The proposed concept provides a novel signal-on strategy for the sensitive detection of other cancer markers in the electrochemical sensing field. [ABSTRACT FROM AUTHOR]

Redox-responsive cationic polymers have gained considerable attention in gene delivery due to low cytotoxicity and spatio-temporal release of DNA into the cells. Here, we reported the synthesis of reducible disulfide conjugated polyethyleneimine (1.8 kDa) (denoted as SS-PEI) and its application to transfer pEGFP-ZNF580 plasmid (pZNF580) into EA.hy926 cell. This reducible SS-PEI polymer was prepared by one-step polycondensation reaction of low molecular weight PEI with bis-(p-nitrophenyl)-3,3′-dithiodipropionate. The SS-PEI successfully condensed pZNF580 into nano-sized complexes (170 ± 1.5 nm to 255 ± 1.6 nm) with zeta potentials of 3 ± 0.4 mV to 17 ± 0.9 mV. The complexes could be triggered to release pZNF580 when exposed to the reducing environment of 5 mM dithiothreitol. Besides, the SS-PEI exhibited low cytotoxicity. In vitro transfection results showed that SS-PEI exhibited good transfection efficiency comparable to PEI25kDa. Thus, the SS-PEI could act as an reducible gene carrier with good transfection efficiency and low cytotoxicity. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy (DR) is a serious neurodegenerative disease that is induced by hyperglycaemia. Oxidative stress, inflammation and endoplasmic reticulum (ER) stress are involved in the development of DR. Sulforaphane (SF) is widely found in cruciferous plants and has a protective effect against retinal neurodegeneration in diabetes, but the mechanism is unclear. In this study, we investigated the mechanism by which SF protects against photoreceptor degeneration in diabetes. In vivo, a mouse model of diabetes was established by streptozotocin (STZ) injection, and the mice were treated with/without SF. Electroretinography (ERG) and H&E staining were used to evaluate retinal function and morphology. In vitro, 661w cells were treated with AGEs with/without SF. Cell viability and apoptosis were analysed by CCK-8 assay and flow cytometry. The expression of proteins and genes was assessed by western blot and qRT-PCR. The amplitude of the a-wave was decreased and the morphology was changed in the diabetic mice, and these changes were delayed by SF treatment. The percentage of apoptotic cells was increased and the cell viability was decreased after the treatment of 661w cells with AGEs. Moreover, the expression of GRP78, Txnip and TNFα was increased, however, this increased expression was reversed by SF treatment via AMPK pathway activation. Taken together, these data show that SF can delay photoreceptor degeneration in diabetes, and the underlying mechanism is related to the inhibition of ER stress, inflammation and Txnip expression through the activation of the AMPK pathway. [ABSTRACT FROM AUTHOR]

Network representation learning, as an approach to learn low dimensional representations of vertices, has attracted considerable research attention recently. It has been proven extremely useful in many machine learning tasks over large graph. Most existing methods focus on learning the structural representations of vertices in a static network, but cannot guarantee an accurate and efficient embedding in a dynamic network scenario. The fundamental problem of continuously capturing the dynamic properties in an efficient way for a dynamic network remains unsolved. To address this issue, we present an efficient incremental skip-gram algorithm with negative sampling for dynamic network embedding, and provide a set of theoretical analyses to characterize the performance guarantee. Specifically, we first partition a dynamic network into the updated, including addition/deletion of links and vertices, and the retained networks over time. Then we factorize the objective function of network embedding into the added, vanished and retained parts of the network. Next we provide a new stochastic gradient-based method, guided by the partitions of the network, to update the nodes and the parameter vectors. The proposed algorithm is proven to yield an objective function value with a bounded difference to that of the original objective function. The first order moment of the objective difference converges in order of O (1 n 2 ) , and the second order moment of the objective difference can be stabilized in order of O (1) . Experimental results show that our proposal can significantly reduce the training time while preserving the comparable performance. We also demonstrate the correctness of the theoretical analysis and the practical usefulness of the dynamic network embedding. We perform extensive experiments on multiple real-world large network datasets over multi-label classification and link prediction tasks to evaluate the effectiveness and efficiency of the proposed framework, and up to 22 times speedup has been achieved. [ABSTRACT FROM AUTHOR]

Hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine (CsA) have been widely accepted as the standard first-line treatments for severe aplastic anemia (SAA). However, most of the patients with SAA had a slim chance to access these strategies in developing countries. Here, we reported 10-year results in a cohort of 232 patients with SAA who received a novel IST of CsA, levamisole, and danazol (CsA&LMS-based regimen). The cumulative incidence of response was 52.1% at 6 months, 66.4% at 12 months, and 77.1% at 24 months. The 10-year overall survival (OS) and failure-free survival was 60.2% and 48.3%, respectively. Positive predictors of OS in multivariate analysis were higher pretreatment ANC, younger age, higher pretreatment absolute reticulocyte count (ARC), and response within 6 months. The probability of CsA&LMS discontinuation was 50.2% at 10 years. With a slow CsA&LMS taper, the actuarial risk for relapse was only 9.5%. The cumulative incidence of MDS/AML was 8.2% at 10 years. The long-term follow-up information demonstrated that the CsA&LMS regimen could be a promising strategy for patients with SAA in developing countries. [ABSTRACT FROM AUTHOR]

Objective: To reveal the effect of foods with different natures on cold or hot syndrome and gastrointestinal bacterial community structure in mice. Methods: Forty-five 6-week-old male ICR Kunming mice of clean grade were divided into 5 groups, 9 per group, including the control (CK), hot nature herbs (HM), Hong Qu glutinous rice wine (RW), tea rice wine (TW), and cold nature herbs (CM) groups. Distilled water or corresponding herbs were administered to mice (0.01 mL/g body weight) in the 5 groups by gastric infusion respectively, once daily for 28 d. Appearance, behavior, and serum biochemical indicators, including 5-hydroxytryptamine (5-HT), thyroid stimulating hormone (TSH), noradrenaline (NE), cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), the hot nature index, as well as the gastrointestinal bacterial community structure were analyzed in all groups after treatment. Results: After supplementation for 28 d, CM and TW mice showed different degrees of cold syndrome, and HM and RW mice showed different degrees of hot syndrome. Compared with the HM and RW mice, the TSH, NE, cAMP levels and hot nature indices in the CM and TW mice were significantly decreased and 5-HT and cGMP levels were significantly increased (P<0.05). There was no obvious change in appearance or behavior in CK mice. Results of clustering analysis showed that the gastrointestinal bacterial community structures were highly similar in TW and CM mice as well as in RW and HM mice, and that they were from the same branch, respectively, when the distance was 0.02. The key microbes associated with cold syndrome were Lachnospiraceae uncultured, Lactococcus, etc., and the key microbes associated with hot syndrome were S24-7 norank, Ruminococcaceae uncultured, etc. Conclusion: The interventions with different nature foods could change cold or hot syndrome in mice, leading to changes in gastrointestinal bacterial community structure. [ABSTRACT FROM AUTHOR]

This paper presents a new cell culture platform enabling label-free surface-enhanced Raman spectroscopy (SERS) analysis of biological samples. The platform integrates a multilayered metal-insulator-metal nanolaminated SERS substrate and polydimethylsiloxane (PDMS) multiwells for the simultaneous analysis of cultured cells. Multiple cell lines, including breast normal and cancer cells and prostate cancer cells, were used to validate the applicability of this unique platform. The cell lines were cultured in different wells. The Raman spectra of over 100 cells from each cell line were collected and analyzed after 12 h of introducing the cells to the assay. The unique Raman spectra of each cell line yielded biomarkers for identifying cancerous and normal cells. A kernel-based machine learning algorithm was used to extract the high-dimensional variables from the Raman spectra. Specifically, the nonnegative garrote on a kernel machine classifier is a hybrid approach with a mixed nonparametric model that considers the nonlinear relationships between the higher-dimension variables. The breast cancer cell lines and normal breast epithelial cells were distinguished with an accuracy close to 90%. The prediction rate between breast cancer cells and prostate cancer cells reached 94%. Four blind test groups were used to evaluate the prediction power of the SERS spectra. The peak intensities at the selected Raman shifts of the testing groups were selected and compared with the training groups used in the machine learning algorithm. The blind testing groups were correctly predicted 100% of the time, demonstrating the applicability of the multiwell SERS array for analyzing cell populations for cancer research. Sensors: improved Raman spectroscopy for cell culture analysis Researchers in the USA have developed a cell culture platform which enhances spectroscopic analysis, making it possible to carry out molecular profiling of biological samples without any labeling. A team led by Masoud Agah and Wei Zhou of Virginia Tech incorporated nanolaminated plasmonic structures into the surface of a multi-well cell culture plate. This modification improves the performance of Raman spectroscopy, facilitating more sensitive and precise biochemical profiling, and the resulting spectra were analyzed via machine learning. The team tested their approach by using it to discriminate samples of normal breast tissue, breast cancer cells, and prostate cancer cells. The analysis distinguished the cell types with over 90% accuracy. This approach can be used for label-free analysis of diagnostic biomarkers to identify specific cancer subtypes, and further work may make it possible to analyze samples of mixed cells. [ABSTRACT FROM AUTHOR]

Pericyclic reactions are powerful transformations for the construction of carbon–carbon and carbon–heteroatom bonds in organic synthesis. Their role in biosynthesis is increasingly apparent, and mechanisms by which pericyclases can catalyse reactions are of major interest1. [4+2] cycloadditions (Diels–Alder reactions) have been widely used in organic synthesis2 for the formation of six-membered rings and are now well-established in biosynthesis3–6. [6+4] and other 'higher-order' cycloadditions were predicted7 in 1965, and are now increasingly common in the laboratory despite challenges arising from the generation of a highly strained ten-membered ring system8,9. However, although enzyme-catalysed [6+4] cycloadditions have been proposed10–12, they have not been proven to occur. Here we demonstrate a group of enzymes that catalyse a pericyclic [6+4] cycloaddition, which is a crucial step in the biosynthesis of streptoseomycin-type natural products. This type of pericyclase catalyses [6+4] and [4+2] cycloadditions through a single ambimodal transition state, which is consistent with previous proposals11,12. The [6+4] product is transformed to a less stable [4+2] adduct via a facile Cope rearrangement, and the [4+2] adduct is converted into the natural product enzymatically. Crystal structures of three pericyclases, computational simulations of potential energies and molecular dynamics, and site-directed mutagenesis establish the mechanism of this transformation. This work shows how enzymes are able to catalyse concerted pericyclic reactions involving ambimodal transition states. Enzymatic catalysis of pericyclic [6+4] cycloaddition reactions to form ten-membered rings is observed during biosynthesis of the macrocyclic antibiotic streptoseomycin, and the mechanism of these transformations is established. [ABSTRACT FROM AUTHOR]

This paper presents a physics-based prediction of crack initiation at the microstructure level using the phase field (PF) model without finite element discretization, coupled with an efficient and accurate modeling of crack propagation at macro-scale based on extended finite element method (XFEM). Although the macro-scale model assumes linear elastic material behavior, at micro-scale the behavior of plastically deforming heterogeneous polycrystals is taken into account by coupling the PF model and a crystal plasticity model in the fast Fourier transform computational framework. A sequential coupling has been established for the multiscale modeling where the macro-scale finite element (FE) model determines the hot spots at each cyclic loading increment and passes the associated stress/strain values to the unit-cell phase-field model for accurate physics-based microstructure characterization and prediction of plasticity induced crack initiation. The PF model predicts the number of cycles for the crack initiation and the phenomenological crack growth models are employed to propagate the initiated crack by the appropriate length to be inserted in the FE mesh. Finally, the XFEM solution module is activated to perform mesh independent crack propagation from its initial crack size to the final size for the total life prediction. The effectiveness of the proposed multiscale method is demonstrated through numerical examples. [ABSTRACT FROM AUTHOR]

A rapid and economical method using modified QuEChERS sample pretreatment coupled with high-sensitivity gas chromatography/triple quadrupole mass spectrometry was established to simultaneously determine ten pyrethroid pesticides in fruits and vegetables. All pesticides were detected within 20 min of one injection. Concurrent backflushing provided column protection, greatly facilitating instrument maintenance. For quantitation, matrix-matched calibration was used to compensate for signal-enhancement effects and to ensure the precision of the method. The limit of detection (LOD) was in the range of 0.3-4.9 μg/kg. The recovery rate was from 78.8 to 118.6%, with relative standard deviation (RSD) below 14.8%. The developed method is suitable for rapid and sensitive multi-residue analysis of pyrethroid pesticides in fruits and vegetables. It is good for users in professional institutions that implement safety controls for testing hundreds of agricultural product samples everyday. [ABSTRACT FROM AUTHOR]

Development of earth-abundant electrocatalysts, particularly for high-efficiency hydrogen evolution reaction (HER) under benign conditions, is highly desired, but still remains a serious challenge. Herein, we report a high-performance amorphous CoMoS4 nanosheet array on carbon cloth (CoMoS4 NS/CC), prepared by hydrothermal treatment of a Co(OH)F nanosheet array on a carbon cloth (Co(OH)F NS/CC) in (NH4)2MoS4 solution. As a three-dimensional HER electrode, CoMoS4 NS/CC exhibits remarkable activity in 1.0 M phosphate buffer saline (pH 7), only requiring an overpotential of 183 mV to drive a geometrical current density of 10 mA·cm-2. This overpotential is 140 mV lower than that for Co(OH)F NS/CC. Notably, this electrode also shows outstanding electrochemical durability and nearly 100% Faradaic efficiency. Density functional theory calculations suggest that CoMoS4 has a more favorable hydrogen adsorption free energy than Co(OH)F. [ABSTRACT FROM AUTHOR]

Background: Metastasis is a leading cause of cancer-related death including colorectal cancer (CRC). MicroRNAs are known to regulate cancer pathways and to be expressed aberrantly in cancer. Aberrant sialylation is closely associated with malignant phenotype of tumor cells, including invasiveness and metastasis.Aim: This study aimed to investigate the association of miR-182 and miR-135b with proliferation and invasion by targeting sialyltransferase ST6GALNAC2 in CRC cells and explore the potential molecular mechanism.Methods: We measured the levels of miR-182, miR-135b, and ST6GALNAC2 in a series of CRC cell lines and tissues using real-time PCR. Bioinformatics analysis and luciferase reporter assay were performed to test the direct binding of miR-182 and miR-135b to the target gene ST6GALNAC2. We also analyzed the possible role of miR-182/-135b on colony formation, wound healing, invasion, and tube formation.Results: The expression of miR-182 and miR-135b was higher in tumor tissues compared to adjacent noncancerous tissues of CRC patients, as well as up-regulated in SW620 cells than in SW480 cells with different metastatic potential. By applying bioinformatics analysis and luciferase reporter assay, we identified ST6GALNAC2 as the direct target of miR-182/-135b. Furthermore, miR-182/-135b inhibited significantly ST6GALNAC2 expression, and consistently, ST6GALNAC2 mediated migration, adhesion, invasion, proliferation, and tumor angiogenesis in CRC cell lines. Additionally, PI3K/AKT signaling pathway was regulated by miR-182/135b, which was partially blocked by altered level of ST6GALNAC2 in CRC.Conclusions: The miR-182/-135b/ST6GALNAC2/PI3K/AKT axis may serve as a predictive biomarker and a potential therapeutic target in CRC treatment. [ABSTRACT FROM AUTHOR]

Ni-based catalysts supported on a support with 3D-mesopores, including Ni/KIT-6(EG), Ni/KIT-6(PS) and Ni/KIT-6(DS), were prepared by adding ethylene glycol, direct synthesis and post synthesis methods, respectively, and their catalytic properties were investigated for CO methanation as one of the core technologies of synthetic natural gas production in a continuous flow fixed-bed reactor. The catalysts were characterized by N adsorption-desorption, X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), hydrogen temperature-programmed reduction (H-TPR), hydrogen temperature-programmed desorption (H-TPD) and thermal gravimetric analysis (TGA), respectively. The results showed that Ni/KIT-6(EG) exhibited the best catalytic performance with CO conversion of almost 100% and CH yield of 75% at 450 °C, atmospheric pressure and 60,000 mL/g/h due to the higher dispersion of Ni species, stronger reducibility of NiO and formation of smaller Ni nanoparticles fixed into 3D-mesopores, indicating that adding ethylene glycol was effective to improve catalytic performance of Ni-based catalyst for CO methanation. Moreover, compared with Ni/AlO(EG) prepared using AlO as a support, Ni/KIT-6(EG) showed better catalytic performance owing to the higher specific surface area, stronger reducibility of NiO and confinement effect of 3D-mesopores promoting to produce more active sites. After 60h lifetime test of Ni/KIT-6(EG) at 500 °C, atmospheric pressure and 60,000 mL/g/h, 3D-mesopores were still maintained and no obvious agglomeration of Ni nanoparticles was observed, meaning that Ni species were still well dispersed into 3D-mesopores. As a consequence, Ni/KIT-6(EG) exhibited superior catalytic performance and stability, which makes it a promising candidate for CO methanation. [ABSTRACT FROM AUTHOR]

Analytical solutions for interfacial diffusion-induced creep rate and stress relaxation in metal matrix particulate composites are developed under triaxial loading. Based on the Eshelby inclusion theory, the driving forces for interface diffusion and interface slip are obtained, respectively, and the relationship between them is clarified. The effects of the triaxial loading, the volume fraction of the inclusion, and the modulus ratio of the inclusion and matrix on the creep rate and stress relaxation are analyzed. In addition, the error caused by the scale effect is corrected by fitting the finite element results with the nonlinear least square method. The present solutions provide an important reference for various engineering applications of metal matrix particulate composites. [ABSTRACT FROM AUTHOR]

Physical activity monitoring for youth is an area of increasing scientific and public health interest due to the high prevalence of obesity and downward trend in physical activity. However, accurate assessment of such activity remains a challenging problem because of the complex nature in which certain activities are performed. In this study, we formulated the issue as a machine learning problem-using a diverse set of 19 physical activities commonly performed by youth-via two approaches: activity recognition and intensity estimation. With the aid of training data, we implemented a distance metric learning method called DML-KNN that utilizes time-frequency features and is capable of effectively classifying both continuous and intermittent movement in youth subjects. Four different time-frequency feature extraction methods were then systematically evaluated. Our results show that the DML-KNN method performed competitively, especially when using features extracted by the Tamura method for intensity estimation, and by the Square Coefficient method for activity recognition. [ABSTRACT FROM AUTHOR]

In this paper, we show how to harness both low-rank and sparse structures in regular or near-regular textures for image completion. Our method is based on a unified formulation for both random and contiguous corruption. In addition to the low rank property of texture, the algorithm also uses the sparse assumption of the natural image: because the natural image is piecewise smooth, it is sparse in certain transformed domain (such as Fourier or wavelet transform). We combine low-rank and sparsity properties of the texture image together in the proposed algorithm. Our algorithm based on convex optimization can automatically and correctly repair the global structure of a corrupted texture, even without precise information about the regions to be completed. This algorithm integrates texture rectification and repairing into one optimization problem. Through extensive simulations, we show our method can complete and repair textures corrupted by errors with both random and contiguous supports better than existing low-rank matrix recovery methods. Our method demonstrates significant advantage over local patch based texture synthesis techniques in dealing with large corruption, non-uniform texture, and large perspective deformation. [ABSTRACT FROM AUTHOR]

This paper focuses on boundary stabilization of a one-dimensional wave equation with an unstable boundary condition, in which observations are subject to arbitrary fixed time delay. The observability inequality indicates that the open-loop system is observable, based on which the observer and predictor are designed: The state of system is estimated with available observation and then predicted without observation. After that equivalently the authors transform the original system to the well-posed and exponentially stable system by backstepping method. The equivalent system together with the design of observer and predictor give the estimated output feedback. It is shown that the closed-loop system is exponentially stable. Numerical simulations are presented to illustrate the effect of the stabilizing controller. [ABSTRACT FROM AUTHOR]

A density functional theory and time-dependent density functional theory approaches were used to understand the structure–property relationships of a series of Ir(III) complexes Ir(x-NHC)(y-ppy)2 [where NHC = 2,3-dihydro-1-methyl-3-phenyl-1H-imidazole, ppy = 2-phenylpyridine, x = Cl, y = H (1a); x = Cl, y = Cl (1a-Cl); x = Cl, y = F (1a-F); x = Cl, y = CN (1a-CN); x = Cl, y = CF3 (1a-CF3); x = F, y = CF3 (2-CF3)]. The investigations on the electronic structures in the ground and lowest triplet excited states, the frontier molecular orbitals, the absorption and emission spectra, as well as charge injection and transport of these Ir complexes provided a good understanding of the structure–property relationships. Furthermore, the full details of the metal character in the phosphorescent spectra(3MLCT %), triplet energy (ET1), the singlet–triplet splitting energy (ΔES1–Tn), 3MLCT–3MC energy gap, as well as d orbitals splitting revealed that quantum yield was effectively enhanced by introducing CN and CF3 groups on the ppy ligands. The designed complexes 1-CN, 1-CF3, and 2-CF3 are expected to be highly efficient phosphorescent materials in organic light-emitting diodes. [ABSTRACT FROM AUTHOR]