Search

This study was aimed to investigate the preventive effects of N-acetyl-l-cysteine (NAC) against renal tubular cell injury induced by oxalate and stone formation and further explore the related mechanism. Transcriptome sequencing combined with bioinformatics analysis were performed to identify differentially expressed gene (DEG) and related pathways. HK-2 cells were pretreated with or without antioxidant NAC/with or silencing DEG before exposed to sodium oxalate. Then, the cell viability, oxidative biomarkers of superoxidase dismutase (SOD) and malondialdehyde (MDA), apoptosis and cell cycle were measured through CCK8, ELISA and flow cytometry assay, respectively. Male SD rats were separated into control group, hyperoxaluria (HOx) group, NAC intervention group, and TGF-β/SMAD pathway inhibitor group. After treatment, the structure changes and oxidative stress and CaOx crystals deposition were evaluated in renal tissues by H&E staining, immunohistochemical and Pizzolato method. The expression of TGF-β/SMAD pathway related proteins (TGF-β1, SMAD3 and SMAD7) were determined by Western blot in vivo and in vitro. CDKN2B is a DEG screened by transcriptome sequencing combined with bioinformatics analysis, and verified by qRT-PCR. Sodium oxalate induced declined HK-2 cell viability, in parallel with inhibited cellular oxidative stress and apoptosis. The changes induced by oxalate in HK-2 cells were significantly reversed by NAC treatment or the silencing of CDKN2B. The cell structure damage and CaOx crystals deposition were observed in kidney tissues of HOx group. Meanwhile, the expression levels of SOD and 8-OHdG were detected in kidney tissues of HOx group. The changes induced by oxalate in kidney tissues were significantly reversed by NAC treatment. Besides, expression of SMAD7 was significantly down-regulated, while TGF-β1 and SMAD3 were accumulated induced by oxalate in vitro and in vivo. The expression levels of TGF-β/SMAD pathway related proteins induced by oxalate were reversed by NAC. In conclusion, we found that NAC could play an anti-calculus role by mediating CDKN2B/TGF-β/SMAD axis. [ABSTRACT FROM AUTHOR]

Let F q be the finite field of q elements, and F q n its extension of degree n. A normal basis of F q n over F q is a basis of the form { σ i (α) : i = 0 , ⋯ , n - 1 } where σ denotes the Frobenius automorphism of F q n over F q and α ∈ F q n . Normal bases over finite fields have proved very useful for fast arithmetic computations with potential applications to coding theory and to cryptography. Some problems on normal bases are characterized in terms of linearized polynomials. We show that such problems can be finally reduced to the determination of the irreducible factors of x n - 1 over F q . Using this approach, we extend the known results with alternative as well as relatively elementary proofs. And we believe that this approach can be used to deal with other similar problems. [ABSTRACT FROM AUTHOR]

Because of the limited effectiveness of prevailing phylogenetic methods when applied to highly divergent protein sequences, the phylogenetic analysis problem remains challenging. Here, we propose a sequence-based evolutionary distance algorithm termed sequence distance (SD), which innovatively incorporates site-to-site correlation within protein sequences into the distance estimation. In protein superfamilies, SD can effectively distinguish evolutionary relationships both within and between protein families, producing phylogenetic trees that closely align with those based on structural information, even with sequence identity less than 20%. SD is highly correlated with the similarity of the protein structure, and can calculate evolutionary distances for thousands of protein pairs within seconds using a single CPU, which is significantly faster than most protein structure prediction methods that demand high computational resources and long run times. The development of SD will significantly advance phylogenetics, providing researchers with a more accurate and reliable tool for exploring evolutionary relationships. [ABSTRACT FROM AUTHOR]

Hypoxia is a key limiting factor for seedling emergence and establishment of direct-seeded rice (DSR) under submergence. The anaerobic germination (AG) tolerance, therefore, is one of the most critical traits in DSR breeding programs. However, the genetic basis of AG is still unclear. In this study, 229 single segment substitution lines (SSSLs) were arranged in an augmented design in field planting. We evaluated the anaerobic germinability by measuring the SSSLs' coleoptile length (CL) under submergence, and then identified AG QTLs. AG was a typical quantitative trait based on the results of five cropping seasons. We repeatedly detected 19 SSSLs with putative AG QTLs in at least two cropping seasons. Moreover, substitution mapping identified 11 integrated AG QTLs on nine chromosomes, including six positive and five negative QTLs with additive effect contributions ranging from 6.8 to 18.5%. Among the 11 QTLs, qAG4 and qAG11 were novel ones, qAG9 was cloned in a previous study, and the remaining eight QTLs overlapped with reported AG QTLs. Overall, we identified some genetic loci controlling AG in multiple environments, which may be useful for developing varieties suitable for DSR. [ABSTRACT FROM AUTHOR]

Because of the limited effectiveness of prevailing phylogenetic methods when applied to highly divergent protein sequences, the phylogenetic analysis problem remains challenging. Here, we propose a sequence-based evolutionary distance algorithm termed sequence distance (SD), which innovatively incorporates site-to-site correlation within protein sequences into the distance estimation. In protein superfamilies, SD can effectively distinguish evolutionary relationships both within and between protein families, producing phylogenetic trees that closely align with those based on structural information, even with sequence identity less than 20%. SD is highly correlated with the similarity of the protein structure, and can calculate evolutionary distances for thousands of protein pairs within seconds using a single CPU, which is significantly faster than most protein structure prediction methods that demand high computational resources and long run times. The development of SD will significantly advance phylogenetics, providing researchers with a more accurate and reliable tool for exploring evolutionary relationships. [ABSTRACT FROM AUTHOR]

This paper focuses on designing a power allocation strategy for a fuel cell ship. The performance of the fuel cell varies during operation, so a power allocation strategy considering fuel cell performance differences is proposed, which consists of two layers. In the first layer, the maximum power and maximum efficiency of each fuel cell system (FCS) are updated in real-time with an online parameter identification model, which is composed of the fuel cell semi-empirical model and adaptive Kalman filter. The second layer takes the state of charge of the battery energy storage system, the maximum power, and the maximum efficiency as inputs for power allocation. Compared with the equal allocation strategy and daisy chain strategy, the total hydrogen consumption reduces by 5.3% and 15.1% and the total output power of the FCS with poor performance reduces by 14.1% and 15.7%. The results show that the proposed method can improve the efficiency of the ship power system and reduce the operational burden of the FCS with poor performance. [ABSTRACT FROM AUTHOR]

Entanglement-assisted quantum error-correcting (EAQEC) codes are a significant extension of quantum error-correcting codes. It has been found that an EAQEC code can be constructed by an arbitrary classical linear code if the encoder and the decoder share the entangled state c in advance. In this paper, we construct two families of q-ary entanglement-assisted quantum maximum-distance-separable (EAQMDS) codes. This construction produces new EAQMDS codes with variable parameters with respect to the minimum distance d and the number c of maximally entangled states. Moreover, the resulting EAQMDS codes have minimum distance not less than q. [ABSTRACT FROM AUTHOR]

Binary polymer systems show advantage in many applications. Herein, we study the conformational properties of a binary polymer system consisted of flexible and stiff polymers confined in slits using molecular dynamics simulation. The flexible and stiff polymers have the same chain length and concentration. Two surface enrichment structures, surface enrichment structure of stiff polymers and surface enrichment structure of flexible polymers, are observed dependent on the surface property and polymer concentration. In repulsive slits at high polymer concentration, surface enrichment structure of stiff polymers is observed as the unique structure. For attractive slits of the same attraction strength to both polymers, surface enrichment structure of stiff polymers even appears at low polymer concentration. Surface enrichment structure of flexible polymers can be observed when the surface attraction to the flexible polymers is much stronger than that to the stiff polymers. Our simulation results indicate that the structure of the binary polymer system can be controlled by varying the surface properties. [ABSTRACT FROM AUTHOR]

Bladder cancer (BCa) is the most common cancer in the urinary system with high recurrence rate and poor prognosis. Circular RNA (circRNA) is a novel subclass of noncoding-RNA which participate in progression of BCa. Here, we identified a novel circRNA–circ3323 and aimed to investigate the role of circ3323 in progression of BCa. Public data of RNA sequencing was used to identify significant circRNA related to BCa. The role of circRNAs in progression of BCa was assessed in cytotoxicity assay, transwell assay and flow cytometry. Biotin-coupled RNA pull-down and fluorescence in situ hybridization were performed to evaluate the interaction between circRNAs and miRNAs. The expression of circ3323 was higher in BCa tissues and cells than in normal samples. Experiments in vitro showed that the knockdown of circ3323 inhibited cell proliferation and impeded the metastasis of BCa cells. Mechanistically, we demonstrated that circ3323 acts as a sponge for miR-186-5p and promotes host gene APP's expression. Clinically, circ3323 predicts worse overall survival of BCa patients, indicating its prognostic value. Our study identified that circ3323 modulates metastasis of BCa through miR-186-5p/APP axis and may serve as a promising prognostic biomarker for BCa, which provides novel insights into treatment of BCa. [ABSTRACT FROM AUTHOR]

Object restoration is applied in multitudinous fields. It is common that the models that need to be restored have extrinsic reflective symmetry features (ERSF), the detections of which are often applied to their restorations. However, most of these symmetry detection approaches have limitations, especially for the incompletion models with a greater area of missing part and much more complex and obvious features. Therefore, this research proposes a novel object restoration method (ORM-ERSPD) based on extrinsic reflective symmetry plane (ERSP) detection, which can be divided into two steps: extrinsic reflective symmetry plane detection (ERSPD) and object restoration (OR). During ERSPD, the reflected mesh can be computed based on an initial ERSP and aligned to the selected mesh by applying the iterative closest point algorithm. Thus, the reflective middle point set can be obtained between the selected mesh and the aligned reflected mesh to fit for the final ERSP. In OR, the selected mesh is first mirrored, aligned and deformed to the missing part whose boundary is reflected on the complete part for selecting and expanding the mesh. Then, the Boolean operation between the reflected mesh and the input mesh is conducted. Finally, the proposed ORM-ERSPD is applied to a set of incompletion models with global and local ERSF. The results of this research demonstrate that ORM-ERSPD can extract ERSP effectively and robustly and, thus, complete OR successfully. [ABSTRACT FROM AUTHOR]

During the grinding process, the workpiece is not only cut by abrasive grains but adhesive wear also occurs due to high temperature and heavy load, reducing the surface quality of the workpiece. In this paper, a wear test method considering speed, force, wear coefficient, temperature and hardness was proposed. A new physical model of wear prediction was established based on the finite element method and numerical simulation technology. The wear test was carried out on a grinding machine. Comprehensive research on the relationship between the force, temperature, surface morphology and wear volume of the grinding process was studied. The relationship between workpiece speed, grinding depth, cooling lubrication conditions and wear volume of the grinding process was studied. The results show that the wear model can achieve numerical prediction and trend prediction of grinding temperature, surface profile and wear volume, with relative errors between the theoretical and actual values of wear and grinding temperature of 9.84% and 2.07%, respectively. This study provides support for wear prediction and surface quality control of the grinding process from the perspective of temperature and micro material removal. [ABSTRACT FROM AUTHOR]

Purpose: The respiratory tract microbiota are deemed as the gatekeeper to health. Consequently, microbiota dysbiosis can lead to the development of diseases. To identify the exact origins of the localized pathogenic bacteria, we investigated bacterial composition in the upper airway tract. Methods: Separate mucosal swabs were collected from nostril or oropharynx of each participant. Meanwhile, the lymphoid tissues including adenoids and tonsils were collected during operation. DNAs were exacted from all the samples for the following 16S rRNA analysis. Results: At the phylum level, the basic bacterial structures in the adenoids, tonsils, oropharynx, and nostrils were generally similar: five main phyla Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria form the majority of the microbiota. However, across these four sites, the microbiota composition differed. More specifically, the bacterial composition in the nostrils was unique. There, Firmicutes and Actinobacteria were the most abundant phyla, while Bacteroides and Fusobacteria were the least abundant. At the genus level, Staphylococcus, Dolosigranulum, Corynebacterium, and Moraxella were the most plentiful, while Fusobacteria was the least ample. Across all sites, Streptococcus displayed similar abundances. Fusobacteria exhibited higher abundances in the lymphoid tissues and oropharynx. Haemophilus and Neisseria were more plentiful in the tonsils and oropharynx. Notably, Klebsiella, which is normally localized to the gut, was abundant in the adenoids and tonsils. Conclusion: Our data indicate that promising pathogenic bacteria originate from all sites in the upper airway. The upper tract lymphoid tissues, normally considered as immune organs, may also serve as reservoirs for pathogenic bacteria. [ABSTRACT FROM AUTHOR]

Fluid simulation is a well-established research field in computer graphics that aims to generate realistic and visually appealing simulations of fluids, including water, smoke, and fire. Divergence is identified as a crucial factor in achieving realistic fluid behavior. This article presents a GPU optimization of the pointwise incompressible fluid simulation technique, which uses pointwise incompressible velocity interpolation to ensure divergence at arbitrary points, rather than grid cells. Pointwise incompressible velocity interpolation at arbitrary points is the curl of velocity potential. The velocity potential can be obtained from the divergence-free velocities by solving a Poisson equation. To enhance the computational efficiency of the simulation, an odd–even geometric multigrid method is introduced to solve Poisson’s equation on non-power-of-2 resolution grids. Additionally, to recover the potential on grid cells, a warp-level method is proposed via divergence-free velocities on grid cells. The proposed warp-level potential recovery method offers GPU optimization and enhanced efficiency, in contrast to the sweeping method that only provides CPU optimization for potential recovery. Furthermore, a locally enhanced method is proposed to recover the detailed velocity potential within small domains through the use of the odd–even multigrid. The experiments show that the odd–even multigrid outperforms Weber’s multigrid by an average speedup factor of 4.32 across various grid sizes. On the other hand, the warp-level potential recovery method demonstrates notable speedups ranging from approximately 2–6 times for 2D grids and about 1.35–2.64 times for 3D grids when compared to the parallel sweeping method on GPU. The results of these contributions demonstrate remarkable improvements in the efficiency and performance of fluid simulations in computer graphics, harnessing the computational capabilities of modern GPUs to achieve visually appealing and realistic fluid behaviors. [ABSTRACT FROM AUTHOR]

China accounts for 25% of the global greening. There are temporal and spatial differences of China's greening and intrinsic driving forces. Thus, it is crucial to determinize the contributions of human activities and climate change on greening at region scale. The Beijing–Tianjin–Hebei Region (BTHR) is one of the most active areas with human activities in China. It is necessary to explore negative or positive impacts of human activities on the regional greening or browning under climate change. A time series of annual vegetation coverage from satellite data was selected to quantify regional greening in the BTHR from 2000 to 2019 and their responses to climate change and human activities. Results showed generally widespread greening over the last 20 years at an average increased rate of 0.036 decade−1 in vegetation coverage (P < 0.01). Overall warmer and wetter climate across the BTHR were positively correlated with regional greening. The positive effects of human activities on greening accounted for 48.4% of the BTHR, especially the benefits of ecological restoration projects and the agricultural activities. Increases in vegetation coverage had resulted from the combined effects of climate change and human activities. Climate change had a stronger influence on vegetation coverage than human activities. Contributions of climate change to greening and browning was about 74.1% and < 20%, respectively. The decrease in vegetation coverage was mainly the results of the inhibition of human activities. More detailed socioeconomic and anthropogenic datasets are required for further analysis. Further research consideration would focus on the nonlinear responses of vegetation to climate change. [ABSTRACT FROM AUTHOR]

Despite many dedicated accelerators are gaining popularity for their performance and energy efficiency in the deep neural network (DNN) domain, high-level programming support for these accelerators remains thin. In contrast to existing researches targeting the whole DNNs, we choose to dive into details and review this problem from a finer-grained level, operators. Due to performance concerns, operator programmers may have to take hand-written assembly as their first choice, which is error-prone and involves many programming chores. To alleviate this problem, we propose TOpLib, a compiler-assisted template library. By providing a unified user-view abstraction, TOpLib allows programmers to express computational kernels with high-level tensor primitives, which will be automatically lowered into low-level intrinsic primitives via expression templates. Moreover, considering memory management is performance-critical and the optimization strategy of expression template is limited to enumeration based rewriting rules, we implement TOpLib with a compiler-assisted approach. We address the memory reuse challenges into the compiler, which allows TOpLib to make full use of on-chip buffers and result in better performance. Experiments over 55 typical DNN operators demonstrate that TOpLib can generate scalable code with performance faster than or on par with hand-written assembly versions. [ABSTRACT FROM AUTHOR]

Nowadays, silver nanoparticles (AgNPs) have attracted the attention of many researchers due to their special physical, chemical, and biological properties. There is strong evidence that biogenic AgNPs can act as potent anticancer agents through the production of reactive oxygen species (ROS) and initiate the mitochondrial pathway of apoptosis. That is why we decided to use Nepeta bracteata Benth flower extract for the first time to bio-synthesize AgNPs and study their cytotoxic and apoptotic effects on SK-BR-3 cells. AgNPs were biosynthesized at 70 °C after mixing silver nitrate and flower extract with a specific ratio and concentration, then were characterized using various analytical techniques, such as FESEM, FTIR, EDS, and zeta potential. Studies have shown that AgNPs have an irregular and circular shape, with about 99% by weight of silver, carbon, and oxygen. On the other hand, the appropriate size (below 57 nm) and surface charge (− 11.52 mV) make them stable in biological fluids. The better cytotoxic effect of AgNPs compared to flower extract on SK-BR-3 cells was investigated using the MTT method. The positive effect of AgNPs on inhibiting the growth of SK-BR-3 breast cancer cells was again confirmed by the sulforhodamine B staining method, so that AgNPs were able to decrease the density of cancer cells in a concentration-dependent manner. In addition, the flow cytometry test proved that biosynthesized AgNPs using Nepeta bracteata Benth flower extract can induce apoptosis in SK-BR-3 cancer cells. Real-time PCR then proved that the ratio of Bak1/Bclx, as well as caspase-3 expression, was increased due to active ROS-producing biomolecules present in the plant extract, and therefore, AgNPs can activate the mitochondria-dependent apoptosis pathway in breast cancer cells. Finally, their negligible oxidative stress on erythrocytes was confirmed by the lipid peroxidation method and showed that biosynthesized AgNPs can be used for breast cancer treatment without showing adverse effects on erythrocytes. [ABSTRACT FROM AUTHOR]

In this study, in situ electrochemical synthesis of Ni–Mg–Al–LDHs for the treatment of simulated strontium-containing liquid radioactive waste (LRW) from nuclear power plants. The optimal reaction conditions were obtained by single-factor experiments: initial pH of 12, Mg electrode current density (JMg) of 12.5 mA/cm2, Ni–Mg–Al metal molar ratio (RNi_Mg–Al) of 3:1:1 and reaction temperature (T) of 30 °C. The removal rate of Sr2+ can reach up to 99.65%. The synthetic precipitate was characterized by XRD, FESEM-EDS and FT-IR under optimal reaction conditions. The XRD pattern showed that the main component of the precipitate is Ni–Mg–Al–LDHs. The precipitate was characterized by FESEM to have distinct layered double hydroxides (LDHs) structure. The absorption peaks of O–H bonds, C–O bonds, and M–O–M (M is Ni, Mg and Al) bonds appeared in IR spectrum. The method of in situ electrochemical synthesis of Ni–Mg–Al–LDHs has promising applications in the treatment of LRW. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) is a neurodevelopmental disorder that affects about 2% of children. Due to the shortage of clinicians, there is an urgent demand for a convenient and effective tool based on regular videos to assess the symptom. Computer-aided technologies have become widely used in clinical diagnosis, simplifying the diagnosis process while saving time and standardizing the procedure. In this study, we proposed a computer vision-based motion trajectory detection approach assisted with machine learning techniques, facilitating an objective and effective way to extract participants' movement features (MFs) to identify and evaluate children's activity levels that correspond to clinicians' professional ratings. The designed technique includes two key parts: (1) Extracting MFs of participants' different body key points in various activities segmented from autism diagnostic observation schedule (ADOS) videos, and (2) Identifying the most relevant MFs through established correlations with existing data sets of participants' activity level scores evaluated by clinicians. The research investigated two types of MFs, i.e., pixel distance (PD) and instantaneous pixel velocity (IPV), three participants' body key points, i.e., neck, right wrist, and middle hip, and five activities, including Table-play, Birthday-party, Joint-attention, Balloon-play, and Bubble-play segmented from ADOS videos. Among different combinations, the high correlations with the activity level scores evaluated by the clinicians (greater than 0.6 with p < 0.001) were found in Table-play activity for both the PD-based MFs of all three studied key points and the IPV-based MFs of the right wrist key point. These MFs were identified as the most relevant ones that could be utilized as an auxiliary means for automating the evaluation of activity levels in the ASD assessment. [ABSTRACT FROM AUTHOR]

In this study, in-situ electrochemical synthesis of monohydric phosphate intercalated layered double hydroxides (LDHs) was used to remove Sr2+ from the simulated liquid radioactive wastes. The optimum reaction conditions were obtained by response surface methodology (RSM). The removal of Sr2+ can reach up to 99.30% and the adsorption capacity of Zn–Al–LDHs–HPO4 toward Sr2+ was 6.01 mg/g under optimal conditions. With Sr2+ being removed mainly by multilayer chemisorption, the adsorption kinetics followed Lagergren pseudo-second-order kinetic model, and the adsorption isotherms followed Freundlich model. Thermodynamic studies of adsorption showed that the adsorption of Sr2+ to LDHs was a spontaneous and endothermic process. This method of LDHs synthesis simplifies the operational steps and is a promising treatment method because of its low energy consumption, high efficiency and small solid waste volume. This study provides an innovative idea for the treatment of strontium-containing liquid radioactive wastes from nuclear power plants. [ABSTRACT FROM AUTHOR]

It is now understood that the flatfish farming industry faces significant threats from Chinook salmon bafinivirus (CSBV) induced hemorrhagic disease. Developing a prompt and efficient diagnostic method is crucial for effective disease control and minimizing losses in aquaculture production. This research assessed the loop-mediated isothermal amplification (LAMP) technique, using a specific primer set, for rapid and precise detection of CSBV. The primer set for LAMP detection was selected based on its demonstrated high specificity and sensitivity, as confirmed through visualization and gel electrophoresis. The CSBV-LAMP reaction system operated at an effective temperature of 63–67°C for 60 min. Importantly, the LAMP assay could identify viral genomic cDNA at an extremely low concentration of 10 pg/μL within 60 min at 65°C. Moreover, this reaction system accurately detected CSBV in naturally infected flatfish samples, yielding a 100% positive detection rate. [ABSTRACT FROM AUTHOR]

Intercropping with Pleurotus ostreatus has been demonstrated to increase the tea yield and alleviate soil acidification in tea gardens. However, the underlying mechanisms remain elusive. Here, high-throughput sequencing and Biolog Eco analysis were performed to identify changes in the community structure and abundance of soil microorganisms in the P. ostreatus intercropped tea garden at different seasons (April and September). The results showed that the soil microbial diversity of rhizosphere decreased in April, while rhizosphere and non-rhizosphere soil microbial diversity increased in September in the P. ostreatus intercropped tea garden. The diversity of tea tree root microorganisms increased in both periods. In addition, the number of fungi associated with organic matter decomposition and nutrient cycling, such as Penicillium, Trichoderma, and Trechispora, was significantly higher in the intercropped group than in the control group. Intercropping with P. ostreatus increased the levels of total nitrogen (TN), total phosphorus (TP), and available phosphorus (AP) in the soil. It also improved the content of secondary metabolites, such as tea catechins, and polysaccharides in tea buds. Microbial network analysis showed that Unclassified_o__Helotiales, and Devosia were positively correlated with soil TN and pH, while Lactobacillus, Acidothermus, and Monascus were positively correlated with flavone, AE, and catechins in tea trees. In conclusion, intercropping with P. ostreatus can improve the physical and chemical properties of soil and the composition and structure of microbial communities in tea gardens, which has significant potential for application in monoculture tea gardens with acidic soils. [ABSTRACT FROM AUTHOR]

Highlights: An all-covalent organic framework (COF) nanofilm-structured lithium-ion capacitor (LIC) was developed by custom-made COF nanofilms as the anode/cathode. The COF nanofilm-structured LIC exhibits good electrochemical properties via the fast Li+ transport kinetics of the anodic COFBTMB-TP nanofilm and the high specific capacity of the cathodic COFTAPB-BPY nanofilm. This work can realize the charge storage kinetics and capacity balance of anode/cathode in COFTAPB-BPY//COFBTMB-TP LIC. Free-standing covalent organic framework (COFs) nanofilms exhibit a remarkable ability to rapidly intercalate/de-intercalate Li+ in lithium-ion batteries, while simultaneously exposing affluent active sites in supercapacitors. The development of these nanofilms offers a promising solution to address the persistent challenge of imbalanced charge storage kinetics between battery-type anode and capacitor-type cathode in lithium-ion capacitors (LICs). Herein, for the first time, custom-made COFBTMB-TP and COFTAPB-BPY nanofilms are synthesized as the anode and cathode, respectively, for an all-COF nanofilm-structured LIC. The COFBTMB-TP nanofilm with strong electronegative–CF3 groups enables tuning the partial electron cloud density for Li+ migration to ensure the rapid anode kinetic process. The thickness-regulated cathodic COFTAPB-BPY nanofilm can fit the anodic COF nanofilm in the capacity. Due to the aligned 1D channel, 2D aromatic skeleton and accessible active sites of COF nanofilms, the whole COFTAPB-BPY//COFBTMB-TP LIC demonstrates a high energy density of 318 mWh cm−3 at a high-power density of 6 W cm−3, excellent rate capability, good cycle stability with the capacity retention rate of 77% after 5000-cycle. The COFTAPB-BPY//COFBTMB-TP LIC represents a new benchmark for currently reported film-type LICs and even film-type supercapacitors. After being comprehensively explored via ex situ XPS, 7Li solid-state NMR analyses, and DFT calculation, it is found that the COFBTMB-TP nanofilm facilitates the reversible conversion of semi-ionic to ionic C–F bonds during lithium storage. COFBTMB-TP exhibits a strong interaction with Li+ due to the C–F, C=O, and C–N bonds, facilitating Li+ desolation and absorption from the electrolyte. This work addresses the challenge of imbalanced charge storage kinetics and capacity between the anode and cathode and also pave the way for future miniaturized and wearable LIC devices. [ABSTRACT FROM AUTHOR]

Highlights: An all-covalent organic framework (COF) nanofilm-structured lithium-ion capacitor (LIC) was developed by custom-made COF nanofilms as the anode/cathode. The COF nanofilm-structured LIC exhibits good electrochemical properties via the fast Li+ transport kinetics of the anodic COFBTMB-TP nanofilm and the high specific capacity of the cathodic COFTAPB-BPY nanofilm. This work can realize the charge storage kinetics and capacity balance of anode/cathode in COFTAPB-BPY//COFBTMB-TP LIC.Free-standing covalent organic framework (COFs) nanofilms exhibit a remarkable ability to rapidly intercalate/de-intercalate Li+ in lithium-ion batteries, while simultaneously exposing affluent active sites in supercapacitors. The development of these nanofilms offers a promising solution to address the persistent challenge of imbalanced charge storage kinetics between battery-type anode and capacitor-type cathode in lithium-ion capacitors (LICs). Herein, for the first time, custom-made COFBTMB-TP and COFTAPB-BPY nanofilms are synthesized as the anode and cathode, respectively, for an all-COF nanofilm-structured LIC. The COFBTMB-TP nanofilm with strong electronegative–CF3 groups enables tuning the partial electron cloud density for Li+ migration to ensure the rapid anode kinetic process. The thickness-regulated cathodic COFTAPB-BPY nanofilm can fit the anodic COF nanofilm in the capacity. Due to the aligned 1D channel, 2D aromatic skeleton and accessible active sites of COF nanofilms, the whole COFTAPB-BPY//COFBTMB-TP LIC demonstrates a high energy density of 318 mWh cm−3 at a high-power density of 6 W cm−3, excellent rate capability, good cycle stability with the capacity retention rate of 77% after 5000-cycle. The COFTAPB-BPY//COFBTMB-TP LIC represents a new benchmark for currently reported film-type LICs and even film-type supercapacitors. After being comprehensively explored via ex situ XPS, 7Li solid-state NMR analyses, and DFT calculation, it is found that the COFBTMB-TP nanofilm facilitates the reversible conversion of semi-ionic to ionic C–F bonds during lithium storage. COFBTMB-TP exhibits a strong interaction with Li+ due to the C–F, C=O, and C–N bonds, facilitating Li+ desolation and absorption from the electrolyte. This work addresses the challenge of imbalanced charge storage kinetics and capacity between the anode and cathode and also pave the way for future miniaturized and wearable LIC devices. [ABSTRACT FROM AUTHOR]

2,4,6-Tripyridine-s-triazine (TPTZ) spectrophotometric method was applied to determine the concentrations of dissolved monosaccharides (MCHO), polysaccharides (PCHO), and total carbohydrate (TCHO) in seawater samples collected from sea surface to hadal zone and sediment-seawater interface of the Southern Yap Trench in the Western Pacific Ocean. Results show that the concentrations of MCHO, PCHO, and TCHO ranged from 6.3 to 22.3 µmol C/L, 1.1 to 25.4 µmol C/L, and 12.1 to 44.9 µmol C/L, respectively, from the euphotic layer to the hadal zone of the trench. At different sampling stations, the concentrations of MCHO, PCHO, and TCHO in the seawater showed complex vertical variation characteristics, but the overall variation trends were decreasing with water depth. In the Southern Yap Trench, the maximum concentration of MCHO in the seawater appeared in the euphotic layer, and the minimum in the hadal zone. The maximum concentration of PCHO appeared in the euphotic layer, and the minimum in the bathypelagic layer. The water layer where the maxima and minima of the average concentration of TCHO appeared was consistent with that of PCHO. PCHO was the major component of TCHO in the seawater of the Southern Yap Trench. In the seawater from the sediment-seawater interface, the concentrations of MCHO, PCHO, and TCHO ranged from 8.4 to 10.6 µmol C/L, 3.8 to 5.8 µmol C/L, and 12.2 to 15.2 µmol C/L, respectively, and MCHO was the major component of TCHO. The key factors affecting the concentration and existing forms of dissolved sugars in the seawater of the Southern Yap Trench included photosynthesis, respiration, polysaccharide hydrolysis, adsorption and desorption of particulate matter, trench "funnel effect", deep ocean currents, sediment resuspension, and etc. This study provided fundamental data about labile organic matter in abyss and hadal zone of marine environment, which is significant for further understanding of deep-sea organic carbon cycle. [ABSTRACT FROM AUTHOR]

Accurate and timely landslide mapping plays a critical role in emergency response and long-term land use planning. Deep learning–based methods represented by convolutional neural networks have been widely exploited in automatic landslide detection for their outstanding capability of feature representation and end-to-end learning mode. Most of the recent deep learning–based studies used toll-access high-resolution imagery for landslide detection. Considering demands for the future large-scale landslide mapping, this study aims to develop a new deep learning–based method to detect landslides using medium-resolution imagery and digital elevation model (DEM) data which are free-access and covered globally. Firstly, a workflow for constructing the landslide dataset is developed. Then, we design a semantic segmentation model to learn deep features and generate per-pixel landslide predictions. Specifically, the proposed network has a dual-encoder architecture with feature fusion to hierarchically represent deep features from the optical bands and DEM data. We also employ a self-attention module in the decoder of the proposed network to improve the performance. Experiments on two regions demonstrate that our method achieves the best F1 score of 79.24%, outperforming SegNet, U-Net, and Attention U-Net, the models popularly used in the semantic segmentation–based landslide detection. The proposed method may have an application potential in disaster risk assessment and post-disaster reconstruction and provide a technical reference for the large-scale landslide mapping in the future. [ABSTRACT FROM AUTHOR]

Introduction: Since hematopoietic stem cell transplant (HSCT) is an important therapy for malignant and non-malignant pediatric diseases, improving transplant-related mortality remains a challenge. Currently, rituximab, a monoclonal antibody of anti-CD20, is widely used for several post-HSCT complications. However, few studies have focused on the application of rituximab before HSCT. Methods: We conducted a retrospective case–control study from January 2019 to July 2021 to determine this effect in a single center. Forty-eight patients were included in the rituximab group, with a one-to-one ratio matched to the control group. Results: Both the occurrence rate and cumulative incidence rate of Epstein–Barr virus (EBV) infection were significantly lower in the rituximab group than in the without-rituximab group (10.4% vs. 33.3%, p = 0.014 and 12.2% vs. 39.3% p = 0.0026, respectively). Furthermore, without the application of rituximab was identified as a risk factor for post-HSCT EBV infection via both univariate [hazard ratio (HR) = 4.17, 95%CI (1.52–11.43), p = 0.005] and multivariate analyses [HR = 4.65, 95%CI (1.66–13.0), p = 0.003]. Although the overall survival (OS) probability of the rituximab group was comparable to the without-rituximab group, a markedly improved OS of the rituximab group was found in the malignant disease subgroup (78.9% vs. 42.1%, p = 0.032). The outcomes of graft-versus-host disease, neutrophil and platelet engraftment, other viral infections, and the reconstitution of lymphocytes showed no significant differences between the two groups. Conclusions: The administration of rituximab before HSCT may prevent EBV infection following HSCT. [ABSTRACT FROM AUTHOR]

In geophysical exploration, the expression of the electromagnetic field in homogeneous layered media involves Hankel integrals, and the kernel function can be simplified into a combination of zero- and first-order Bessel functions. Owing to the complex nature of the electromagnetic field, only a few analytical expressions for the Hankel integrals of the electromagnetic field in layered media exist. Moreover, as the argument of the Bessel functions increases, the Hankel integrals exhibit rapid oscillations and slow decay, making it difficult for the computation of the electromagnetic field to achieve high accuracy, especially for high-frequency and long-range transmission and reception scenarios. To address this issue, we propose a fully analytical integration method applicable to both high and low frequencies and long and short transmission and reception distances. The study used quadratic function interpolation for the coefficient part of the Hankel integrals in the expression of the electromagnetic field in layered media. The interpolated results within each element, multiplied by the Bessel functions, could derive analytical expressions. Then, by summing up all the discrete elements, the numerical solution of the Hankel integrals could be obtained, resulting in a high-precision numerical simulation of the layered media. The fully analytical integration algorithm was tested using the expressions of the electromagnetic field in the entire space with different forms of Bessel function integrals. The computational results demonstrated the correctness and high accuracy of the algorithm. The proposed algorithm exhibited high computational accuracy in different frequency ranges and transmission and reception distances, especially in high-frequency and long-distance scenarios, where its accuracy exceeds that of the four selected digital filtering algorithms by over two orders of magnitude, indicating its strong universality.. [ABSTRACT FROM AUTHOR]

Rationale: Studies have shown the potential neuroprotective effect of xanthohumol, while whether xanthohumol has the ability of repairing cognitive impairment and its underlying mechanism still remains obscure. Objectives: To unravel the mechanism of xanthohumol repairing cognitive impairment caused by estrogen deprivation. Methods: C57BL/6 J female mice that underwent bilateral ovariectomy to establish cognitive decline model were randomly divided into three xanthohumol-treated groups and a saline-treated model group. For identifying the neuroprotective function of xanthohumol, Morris water maze (MWM) test and open field test (OFT) were conducted. After extracting total RNA of mouse hippocampus of different groups, mRNA-seq and microRNA (miRNA)-seq analysis were performed, and the differentially expressed miRNAs (DEMIs) and their target genes were further validated by qPCR. MiR-532-3p and its downstream gene Mpped1 were screened as targets of xanthohumol. Influence of miR-532-3p/Mpped1 to cognitive ability was examined via MWM test and OFT after stereotactic brain injection of Mpped1 overexpressed adeno-associated virus. The regulation of miR-532-3p on Mpped1 was confirmed in hippocampal neuronal cell line HT22 by luciferase reporter gene assay. Results: Xanthohumol treatment reversed the cognitive decline of OVX mice according to behavioral tests. By comparing miRNA levels of xanthohumol-treated groups with saline-treated group, we found that the main changed miRNAs were miR-122-5p, miR-532-3p, and miR-539-3p. Increased miR-532-3p in OVX mice was suppressed by xanthohumol treatment. Furthermore, the downstream gene of miR-532-3p, Mpped1, was also increased by xanthohumol and showed the capability of relieving cognitive impairment of OVX mice after overexpressed in hippocampus. The 3′ untranslated region of Mpped1 was identified as the target region of miR-532-3p, and agomiR-532-3p remarkably reduced the expression of Mpped1 mRNA. Conclusions: Xanthohumol has the ability of repairing cognitive impairment through removing the inhibition of miR-532-3p on Mpped1 in mouse hippocampus. This finding not only advances the understanding of neuroprotective mechanism of xanthohumol, but also provides novel treatment targets for dementia of postmenopausal women. [ABSTRACT FROM AUTHOR]

In order to provide a basis for the prevention of RA, this systematic review and meta-analysis evaluated the association between passive smoking and the risk of developing RA. We searched electronic databases, including PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and Embase, for published literature from the establishment to March 2022. Then we included subject-related cohort studies and case–control studies, and two researchers independently screened and extracted relevant data. Finally, we performed a meta-analysis, cumulative meta-analysis, and dose–response meta-analysis using the Stata software and evaluated the included literature for the level of evidence. This meta-analysis included three case–control and three cohort studies. There was only a small amount of statistical heterogeneity among the studies (I2 = 34.9%). According to the study results, the risk of RA was 12% higher in passive smokers than in unexposed individuals. In subgroup analysis, a 12% increase in the prevalence of RA was observed in those exposed to passive smoking in adulthood. The developing RA rate was 34% higher in individuals exposed to passive smoking during childhood than in unexposed individuals. As time progressed and with the inclusion of extensive sample studies in the cumulative meta-analysis, the precision of the overall incidence effect values gradually increased. A dose–response meta-analysis showed no statistical significance that the risk of RA increased with the number of passive smoking years. Passive smoking may relate to the risk of RA, especially in childhood exposures. [ABSTRACT FROM AUTHOR]

Background: Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent nuclear receptor and highly expressed in human and rodent lungs. 15-Deoxy-delta-12,14-prostaglandin J2 (15d-PGJ2), known for cyclopentenone prostaglandin, is the endogenous ligand of PPARγ. However, the associations among PPARγ, 15d-PGJ2 and chronic obstructive pulmonary disease (COPD) were unclear. Methods: All 130 fasting blood samples and 40 lung specimens were obtained from COPD patients and control subjects. Serum 15d-PGJ2 was detected by ELISA. The expressions of oxidative stress indicators were measured using western blotting and PPARγ nuclei were evaluated with immunohistochemistry in lungs. The associations among serum 15d-PGJ2, pulmonary PPARγ and oxidative stress indicators, and COPD were estimated. Results: Serum 15d-PGJ2 was reduced in COPD patients compared with healthy volunteers. Linear and logistic regression analysis indicated that serum 15d-PGJ2 was positively associated with pulmonary function in COPD patients. In addition, PPARγ-positive nuclei were reduced and oxidative stress indicators, included HO-1 and NOX-4, were increased in lungs of COPD patients. Further correlative analysis suggested that pulmonary function parameters was positively correlated with serum 15d-PGJ2 and pulmonary PPARγ-positive nuclei, inversely related to oxidative stress indicators in lungs of COPD patients. Pretreatment with 15d-PGJ2 obviously attenuated TNFα-induced oxidative stress in BEAS-2B cells. Conclusions: Serum 15d-PGJ2 and pulmonary PPARγ are reduced, and oxidative stress is elevated in COPD patients. Serum 15d-PGJ2 is inversely associated with oxidative stress in COPD patients. [ABSTRACT FROM AUTHOR]

The composition and concentration of dissolved free amino acid (DFAA) of seawater samples collected in May 2016 from the surface to the hadal zone of the northern region of the Yap Trench were analyzed by pre-column derivatization of o-phthalaldehyde. Results show that the average concentration of DFAA in the study area was 0.47±0.36 µmol/L. In different sampling stations, the concentrations of DFAA with water depth showed complex variation patterns. At the sediment-seawater interface, the concentrations of DFAA in the western side of the trench were obviously higher than that in its eastern side. In the study area, there were no significant correlations between the concentrations of DFAA and the environmental parameters such as concentrations of chlorophyll a (Chl a), dissolved oxygen (DO), pH, and dissolved inorganic nitrogen (DIN), indicating that the concentrations of DFAA in seawater of the trench are affected by many factors, such as photosynthesis, respiration, temperature, pressure, illumination, and circulation. The dominant DFAA are similar in different water layers of sampling stations, including aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), and serine (Ser). The composition of different amino acids, and the relative abundance of acidic, basic, and neutral amino acids might be related to the sources and consumption of various amino acids. Nine pairs of amino acids in the DFAA showed significantly positive relationship by correlation matrix analysis, suggesting that they might share similar biogeochemical processes. The degradation index (DI) of the DFAA in seawater of the Yap Trench could reflect the degradation, source, and freshness of DFAA in the trench to some extents. This is a preliminary study of amino acids from sea surface to hadal zone in the ocean, more works shall be done in different trenches to reveal their biogeochemical characteristics in extreme marine environments. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (T2DM), one of the most common carbohydrate metabolism disorders, is characterized by chronic hyperglycemia and insulin resistance (IR), and has become an urgent global health challenge. Mesenchymal stem cells (MSCs) originating from perinatal tissues such as umbilical cord (UC) and amniotic membrane (AM) serve as ideal candidates for the treatment of T2DM due to their great advantages in terms of abundant source, proliferation capacity, immunomodulation and plasticity for insulin-producing cell differentiation. However, the optimally perinatal MSC source to treat T2DM remains elusive. This study aims to compare the therapeutic efficacy of MSCs derived from AM and UC (AMMSCs and UCMSCs) of the same donor in the alleviation of T2DM symptoms and explore the underlying mechanisms. Our results showed that AMMSCs and UCMSCs displayed indistinguishable immunophenotype and multi-lineage differentiation potential, but UCMSCs had a much higher expansion capacity than AMMSCs. Moreover, we uncovered that single-dose intravenous injection of either AMMSCs or UCMSCs could comparably reduce hyperglycemia and improve IR in T2DM db/db mice. Mechanistic investigations revealed that either AMMSC or UCMSC infusion could greatly improve glycolipid metabolism in the liver of db/db mice, which was evidenced by decreased liver to body weight ratio, reduced lipid accumulation, upregulated glycogen synthesis, and increased Akt phosphorylation. Taken together, these data indicate that the same donor-derived AMMSCs and UCMSCs possessed comparable effects and shared a similar hepatoprotective mechanism on the alleviation of T2DM symptoms. [ABSTRACT FROM AUTHOR]

In order to determine procalcitonin, a sandwich-type ratiometic electrochemical immunosensor was developed by differential pulse voltammetry (DPV). Due to high chemical stability and good biocompatibility, graphitic carbon nitride (g-C3N4) could be used as feasible supporter to carry silver nanoparticles (Ag NPs) with an obvious oxidative peak (measured typically at + 0.3 V vs. SCE). Ag NPs loaded onto g-C3N4 were not only beneficial to prevent the agglomeration of Ag NPs, but also favorable to improve the electron transfer velocity of g-C3N4. Moreover, the g-C3N4-Ag NPs as the matrix could immobilize primary antibody by Ag–N bond. Nile blue A (NBA), an excellent redox probe based on the redox reaction with two-electrons, provides a current signal at − 0.38 V (vs. SCE). Zr-based metal organic framework (UiO-67), an ideal framework material with large specific surface area and high porosity, could absorb the substantial water-soluble NBA by electrostatic adsorption. The UiO-67 modified by NBA (NBA-UiO-67) owned admirable biocompatibility and was a qualifying marker to load the secondary antibody. For the immunosensor, the current ratio of NBA to Ag NPs (INBA/IAg NPs) was increased as the concentrations of PCT increased. Under the optimum conditions, the linear range of the immunosensor was 0.005 to 50 ng/mL; the detection limit was 1.67 pg/mL (S/N = 3), which reflected the excellent analytical performance of the sensor. The proposed immunosensor strategy is a simple and dependable platform, with great application potential in biometric analysis. [ABSTRACT FROM AUTHOR]

Background: The risk factors for the survival of elderly patients with oral squamous cell carcinoma (OSCC) are multifarious. Here, we developed a novel clinical signature to serve as an indicator of prognosis in these patients. Materials and methods: Clinicopathological data were collected for 554 patients aged ≥ 60 years who were treated for primary OSCC. Overall survival (OS), disease-specific survival, and disease-free survival were the primary outcomes. Results: Multivariate cox regression analysis showed that high N stage, low hemoglobin level, low body mass index (BMI), and high neutrophil-to-lymphocyte ratio (NLR) showed a poor survival (P < 0.05). A nomogram was constructed with a c-index of 0.702. Conclusion: A novel clinical signature including hemoglobin level, BMI, and NLR, which are obtained through noninvasive examinations can be used as prognostic indicators in clinical practice for elderly patients with OSCC. [ABSTRACT FROM AUTHOR]

Low-temperature germinability (LTG) is an important agronomic trait that can affect the planting time, planting area, and grain yield of staple crops, such as rice. However, the genetic mechanism of LTG is still unclear. In this study, a multi-parental permanent population with 208 single segment substitution lines (SSSLs) was used to conduct a genetic dissection for LTG across four cropping seasons. LTG was a typical quantitative trait with a high combined broad-sense heritability of 0.71. By comparison with the recipient parent, Huajingxian74, 24 SSSLs were identified as carrying LTG QTLs, which were further merged into integrated QTLs with shorter genetic distances by substitution mapping. Finally, 14 LTG QTLs were mapped on ten chromosomes, including seven positive-effect and seven negative-effect QTLs, with additive effect contributions ranging from 19.2 to 39.9%. qLTG3a, a main-effect and novel QTL, was confirmed by bulk segregant analysis using an F2 segregating population, and five key recombinants were selected to develop F3 populations for progeny testing. Marker-trait association analysis fine mapped qLTG3a to a 332.7-kb physical region between markers M6026 and M6341. Within this interval, 40 annotated genes were revealed, and three genes (Os03g0213300, Os03g0214400, and Os03g0214600) were considered as pivotal candidate genes for qLTG3a based on their sequence variations and expression patterns. Besides low temperature, qLTG3a can also enhance seed germination under standard temperature and osmotic stress. In summary, this study identified some genetic factors regulating LTG and opened a new window for breeding elite direct-seeded rice varieties. It will help reduce the climate risk in the production process of rice, which is of great significance to ensuring food security. [ABSTRACT FROM AUTHOR]

Hyaluronic acid (HA) is a multiple-function biopolymer that is widely used in food, cosmetic, and biomedical fields. In group C streptococci, the major workhorse of HA production in industry, the HA biosynthetic pathway has been proposed, while how HA synthesis is regulated is unclear. In this study, we identified twenty-five putative transcriptional repressors in S. zooepidemicus and studied whether they regulate HA synthesis or not. The individual gene deletion strain was firstly constructed, and the phenotypic changes of the corresponding deletion strains in stress tolerance and HA production were detected. The hrcA deletion strain is more sensitive to high temperature, and the rex deletion strain is more resistant to the oxidative stress. Three transcriptional repressor deletions resulted significantly decreased transcriptional levels of hasA, among which the scrR deletion strain shows most dramatical decrease in HA production. The regulatory mechanism of how ScrR affects the production of HA was further explored by transcriptional expression analysis of scrA and scrB, two direct target genes of ScrR regulon. Our results indicates that the deficiency of ScrR results in the unbalanced expression of scrA and scrB, which might also partly account for the decreasing production of HA. In agreement with the speculation, overexpression of scrB in ΔscrR genetic background results in 80% improvement in HA production. Taken together, the systemic genetic study of transcriptional repressors expands our understanding for the physiological regulation process of S. zooepidemicus and should help in the development of high-performance industrial strains for the efficient production of HA. Key points: • Twenty-two transcriptional repressor genes in S. zooepidemicus were deleted individually, and the phenotypes of corresponding mutants on a variety of conditions were characterized. • HrcA deficiency showed inferior cell tolerance to high temperature, and Rex deficiency showed superior cell tolerance to reactive oxygen stress, and four repressors deficiency showed inferior hyaluronic acid synthesis, among which the transcriptional levels of hasA of three mutants decreased significantly. • Optimizing sucrose metabolic flux can enhance hyaluronic acid synthesis significantly. [ABSTRACT FROM AUTHOR]

In this work, the unique plastic deformation behavior of T2 rolled copper foils under ultrasonic impact (UI) and ultrasonic rolling (UR) has been studied systematically. The numerical simulation and test results show that with the decrease of the thickness of copper sheet, the equivalent plastic strain (PEEQ) value and plastic strain εp formed by UI or UR increase exponentially, and its distribution changes from gradient to uniform on the cross section, which is distinctive from the commonly observed gradient structure in ultrasonically treated bulk materials. Correspondingly, characterized by EBSD and TEM, the 100-μm-thick copper foil treated by UR shows the overall strengthening and forming a sub-micron grain structure with significant refinement and uniform distribution on the cross section. The microstructure homogenization of copper foil is attributed to the rigid wall effect facilitating the elastic-plastic stress wave bounce. The exponential increase of PEEQ and εp is explained as that with the decrease of the thickness of ultrasonic object, on the one hand, the acoustic softening and size effect which can reduce the elastic limit of copper foil are enhanced; on the other hand, the plastic deformation mode changes from stress superposition to dynamic impact. Through the establishment of a new theoretical model, the criterion of ultrasonic dynamic impact effect is deduced and verified by experiments. [ABSTRACT FROM AUTHOR]

As-extruded Mg-1.8Zn-0.5Zr-xGd alloys are thoroughly investigated for their microstructure, mechanical properties and degradation behavior in a wide range of minor Gd alloying (0 ≤ x ≤ 2.5 wt%). These alloys show complete dynamic recrystallization when the extrusion ratio and extrusion temperature are 7.7 and 350 °C, respectively. The resultant grain size decreases with the increase in Gd content until its stabilization. Of many observed second phases in these alloys, one type of second phase mainly consists of the granular (Mg, Zn)3Gd phase, the volume of which gradually increases with the increase in Gd content. The other precipitated nanoscale (Mg, Zn)3Gd second phase shows a coherent interfacial relationship with the alloy matrix. At Gd greater than 1.0wt%, a fraction of the insoluble second phase shows transformation into black paralleled strips, which are noted to be distributed along the extrusion direction. The mechanical characteristics of these alloys show optimal performances at x = 1.5 wt%, while decreasing (increasing) trend for 1.5 < x ≤ 2.5 (0 < x ≤ 1.5). Together with the best corrosion resistance at x = 1.0 wt%, these alloys show increment in the corrosion resistance first and then weakens with the increase in Gd content. This study reveals an optimized scale for minor Gd alloying toward the optimal mechanical properties and corrosion resistance of extruded Mg-Zn-Zr alloys, and hopefully beneficial in biomedical applications. [ABSTRACT FROM AUTHOR]