Search

Isoprene is a common monomer in industrial synthetic rubber. We report the in vitro synthesis of isoprene in a multi-step enzyme cascade immobilized biocatalyst by the mevalonate pathway (MVA pathway). This method offers a new way for expanding the biosynthesis of isoprene. The cascade immobilized biocatalyst (PE-SBA-15-FiEs) was constructed by adsorption- cross-linking, with the five key enzymes (mevalonate kinase (MVK), phosphomevalonate kinase (PMK), Mevalonate diphosphate decarboxylase (MVD), isopentenyl disphosphate isomerase (IDI), and isoprene synthetase (ISPS)) of the MVA pathway immobilized on mesoporous molecular sieve SBA-15 as the carrier with polyethylene glycol diglycidyl ether as the cross-linker. At the optimal reaction pH and temperature, the yield of isoprene reached 453.15 mg/L with the PE-SAB-15-FiE, as compared to 274.52 mg/L with the free enzymes. After it had been used five times, the yield of isoprene was still 404.26 mg/L. Furthermore, the yield of isoprene still reached 372.59 mg/L when it was stored for 30 days at room temperature. Thus, the assembled PE-SBA-15-FiEs cascade immobilized biocatalyst has promising application prospects for the industrial production of isoprene. [ABSTRACT FROM AUTHOR]

An efficient method for the construction of 2,4‐diarylbenzo[4,5]thieno[3,2‐d]pyrimidines through the base‐promoted one‐pot three‐component tandem reactions of o‐nitrochalcones, benzamidine hydrochlorides, and elemental sulfur is described. The salient features of this protocol are the use of cheap and abundant sulfur source, readily available starting materials, transition‐metal‐free and mild conditions, satisfactory yield, and simple workup procedures. This transformation can also carry out on gram scale. [ABSTRACT FROM AUTHOR]

Organic arsenic compounds such as p-aminophenylarsine oxide (p-APAO) are easier for structural optimization to improve drug-like properties such as pharmacokinetic properties, therapeutic efficacy, and target selectivity. In order to strengthen the selectivity of 4-(1,3,2-dithiarsinan-2-yl) aniline 7 to tumor cell, a thiourea moiety was used to strengthen the anticancer activity. To avoid forming a mixture of α/β anomers, the strategy of 2-acetyl's neighboring group participation was used to lock the configuration of 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate from 2,3,4,6-tetra-O-acetyl-α-d-glucopyranosyl bromide. 1-(4-(1,3,2-dithiarsinan-2-yl) aniline)-2-N-(2,3,4,6-tetra-O-acetyl-β-d-glucopyranos-1-yl)-thiourea 2 can increase the selectivity of human colon cancer cells HCT-116 (0.82 ± 0.06 μM vs. 1.82 ± 0.07 μM) to human embryonic kidney 293T cells (1.38 ± 0.01 μM vs. 1.22 ± 0.06 μM) from 0.67 to 1.68, suggesting a feasible approach to improve the therapeutic index of arsenic-containing compounds as chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Hybridization is an important evolutionary force, and heterosis describes the phenomenon where hybrids exhibit superior traits compared to their parents. This study aimed to evaluate the one-hundred-seed weight and fatty acid content in F1 generations, investigating the effects of different parental crosses using a 9 × 3 incomplete diallel design (NCII). One of the challenges faced in this study was the complexity of accurately determining the influence of both genetic and environmental factors on trait inheritance. A total of 36 F1 crosses were analyzed for general combining ability (GCA), specific combining ability (SCA), and heritability. The results showed that the level of each index in F1 is closely related to its parents. Significant differences in GCA and SCA were observed among parental traits in most crosses. The ratio of GCA to SCA ranged from 0 to 3, indicating the pivotal role of SCA over GCA in castor breeding efforts. High narrow-sense heritability was recorded in palmitic acid (30.98%), oleic acid (28.68%), and arachidonic acid (21.34%), suggesting that these traits are predominantly under the control of additive gene action, and hence these characters can be improved by selection. Additionally, heterosis exhibited diverse patterns across traits. Based on the evaluated combining ability, heritability, and heterosis, the inbred lines CSR181 and 20111149 were recommended for castor crossbreeding due to their potential to yield progeny with optimal oil-related traits. This research contributes valuable knowledge to the field of castor breeding, providing a foundation for developing superior castor cultivars. [ABSTRACT FROM AUTHOR]

Immobilization is a crucial method for enzyme recovery and utilization. Among all techniques, physical adsorption stands out as a commonly employed immobilization method, driven by the surface properties of the supporter. In this study, the focus is to investigate the effect of the nature of the supporter surface on the performance of the immobilized enzyme. A range of supporters with varying hydrophilic-hydrophobic properties was obtained by treating cover glasses with piranha etching solution and different silane coupling agents. Subsequently, cellulase was immobilized on these modified supporters for cellulose hydrolysis, aiming to investigate the supporter's impact on the activity and stability of immobilized enzymes. Additionally, the supporters were characterized using infrared spectroscopy, contact angle measurements, and Zeta potential analysis. The results indicate that the stronger the supporter's hydrophobicity, the more pronounced the hydrolytic efficiency of immobilized cellulase. This work provides an effective strategy for utilizing supporter surface properties in the context of physical adsorption. [ABSTRACT FROM AUTHOR]

Motor imagery (MI)-based brain–computer interface (BCI) has emerged as a crucial method for rehabilitating stroke patients. However, the variability in the time–frequency distribution of MI-electroencephalography (EEG) among individuals limits the generalizability of algorithms that rely on non-customized time–frequency segments. In this study, we propose a novel method for optimizing time–frequency segments of MI-EEG using the sparrow search algorithm (SSA). Additionally, we apply a correlation-based channel selection (CCS) method that considers the correlation coefficient of features between each pair of EEG channels. Subsequently, we utilize a regularized common spatial pattern method to extract effective features. Finally, a support vector machine is employed for signal classification. The results on three BCI datasets confirmed that our algorithm achieved better accuracy (99.11% vs. 94.00% for BCI Competition III Dataset IIIa, 87.70% vs. 81.10% for Chinese Academy of Medical Sciences dataset, and 87.94% vs. 81.97% for BCI Competition IV Dataset 1) compared to algorithms with non-customized time–frequency segments. Our proposed algorithm enables adaptive optimization of EEG time–frequency segments, which is crucial for the development of clinically effective motor rehabilitation. [ABSTRACT FROM AUTHOR]

Reputable evidence from multiple studies suggests that excessive and uncontrolled inflammation plays an indispensable role in mediating, amplifying, and protracting acute lung injury (ALI). Traditionally, immunity and energy metabolism are regarded as separate functions regulated by distinct mechanisms, but recently, more and more evidence show that immunity and energy metabolism exhibit a strong interaction which has given rise to an emerging field of immunometabolism. Mammalian lungs are organs with active fatty acid metabolism, however, during ALI, inflammation and oxidative stress lead to a series metabolic reprogramming such as impaired fatty acid oxidation, increased expression of proteins involved in fatty acid uptake and transport, enhanced synthesis of fatty acids, and accumulation of lipid droplets. In addition, obesity represents a significant risk factor for ALI/ARDS. Thus, we have further elucidated the mechanisms of obesity exacerbating ALI from the perspective of fatty acid metabolism. To sum up, this paper presents a systematical review of the relationship between extensive fatty acid metabolic pathways and acute lung injury and summarizes recent advances in understanding the involvement of fatty acid metabolism-related pathways in ALI. We hold an optimistic believe that targeting fatty acid metabolism pathway is a promising lung protection strategy, but the specific regulatory mechanisms are way too complex, necessitating further extensive and in-depth investigations in future studies. [ABSTRACT FROM AUTHOR]

The deep ocean, Earth's untouched expanse, presents immense challenges for exploration due to its extreme pressure, temperature, and darkness. Unlike traditional marine robots that require specialized metallic vessels for protection, deep-sea species thrive without such cumbersome pressure-resistant designs. Their pressure-adaptive forms, unique propulsion methods, and advanced senses have inspired innovation in designing lightweight, compact soft machines. This perspective addresses challenges, recent strides, and design strategies for bioinspired deep-sea soft robots. Drawing from abyssal life, it explores the actuation, sensing, power, and pressure resilience of multifunctional deep-sea soft robots, offering game-changing solutions for profound exploration and operation in harsh conditions. High pressure and low temperature are the greatest challenges faced by scientists to explore deep oceans, which remain largely unknow to us today. Li et al. review these challenges and give insight into designing soft robots, inspired by deep-sea creatures, that enable resilient operations in harsh conditions. [ABSTRACT FROM AUTHOR]

Real-time monitoring of the mechanical behavior of cathode materials during the electrochemical cycle can help obtain an in-depth understanding of the working mechanism of lithium-ion batteries. The LiMn2O4 composite electrode is employed as the working electrode in this artificial cell, which is conceived and produced along with a chemo-mechanical coupling measurement system. The multi-layer beam composite electrode made of LiMn2O4 is monitored in real time using a CCD camera to track its curvature deformation. Experiments show that the curvature of the LiMn2O4 electrode decreases with the extraction of lithium ions and increases during the lithiation process. In the meantime, a theoretical framework was developed to examine the connection between curvature change and mechanical characteristics. Thus, the elastic modulus, strain, and stress of the LiMn2O4 composite electrode were extracted by combining the bending deformation and theoretical model. The results show that the elastic modulus of the LiMn2O4 composite electrode decreases from 59.61 MPa to 12.01 MPa with the extraction of lithium ions during the third cycle. Meanwhile, the stress decreases from 0.46 MPa to 0.001 MPa, and the strain reduces from 0.43 to 0. Its changes reverse during the lithiation process. Those findings could have made a further understanding of the mechanical properties in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

A concise method for the construction of 1‐sulfonyl‐1H‐indoles by the reactions of N‐(2‐iodoaryl)sulfonamides with calcium carbide is described. The notable features of this protocol are the use of inexpensive and easy‐to‐handle solid alkyne source as a surrogate of flammable and explosive gaseous acetylene, wide scope of substrates, high yield, and simple reaction procedure. This method can also be extended to gram scale. [ABSTRACT FROM AUTHOR]

Castor (Ricinus communis L.) seed oil is the commercial source of ricinoleate, a valuable raw material used in many industries. Oleoyl-12-hydroxylase (RcFAH12) is a key enzyme in the biosynthesis of ricinoleate, accumulating nearly 90% of the triacylglycerol in castor seeds. Little is known about the transcriptional regulation of RcFAH12. We used rapid amplification of cDNA 5′ ends (5′RACE) to locate the transcription start site (TSS) of RcFAH12, and the sequence of a 2605 bp region, −2506~+99, surrounding the TSS was cloned. We then investigated these regions to promote β-glucuronidase (GUS) expression in transgenic Arabidopsis by the progressive 5′ and 3′ deletions strategies. The GUS staining showed that the GUS accumulation varied in tissues under the control of different deleted fragments of RcFAH12. In addition, the GUS expression driven by the RcFAH12 promoter markedly accumulated in transgenic seeds, which indicated that RcFAH12 might play an important role in the biosynthesis of ricinoleic acid. This study will lay a potential foundation for developing a tissue-specific promoter in oil-seed crops. [ABSTRACT FROM AUTHOR]

Soft chemo-mechanical (SCM) machines convert chemical energy into mechanical energy. They have the advantages of fast actuation and compliant deformation and possess wide applications in soft robots and flexible smart devices. Using experiments and theoretical modeling, this paper investigates the chemo-mechanical energy flows and the energy conversion cycle in the pressure and volume (P–V) plane of an SCM machine consisting of a soft membrane and cylindrical chambers. The machine generates 16.1 mJ of mechanical energy per cycle. We study heat dissipation as the key issue affecting the conversion efficiency. The states of the conversion cycle calculated from mechanical modeling fit well with those measured experimentally. The design principles and the theoretical methods can be used to guide the fabrication and characterization of SCM actuators and robots. [ABSTRACT FROM AUTHOR]

Cyanophages play an important role in regulating the dynamics of cyanobacteria communities in the hydrosphere, representing a promising biological control strategy for cyanobacterial blooms. Nevertheless, most cyanophages are host-specific, making it difficult to control blooming cyanobacteria via single or multiple cyanophages. In order to address the issue, we explore the interaction between cyanophages and their heterologous hosts, with the aim of revealing the principles of designing and constructing an artificial cyanophage genome towards multiple cyanobacterial hosts. In the present study, we use synthetic biological approaches to assess the impact of introducing a fragment of cyanophage genome into a heterologous cyanobacterium under a variety of environmental conditions. Based on a natural cyanophage A-4L genome (41,750 bp), a truncated cyanophage genome Syn-A-4-8 is synthesized and assembled in Saccharomyces cerevisiae. We found that a 351–15,930 bp area of the A-4L genome has a fragment that is lethal to Escherichia coli during the process of attempting to assemble the full-length A-4L genome. Syn-A-4-8 was successfully introduced into E. coli and then transferred into the model cyanobacterium Synechococcus elongatus PCC 7942 (Syn7942) via conjugation. Although no significant phenotypes of Syn7942 carrying Syn-A-4-8 (LS-02) could be observed under normal conditions, its growth exhibited a prolonged lag phase compared to that of the control strain under 290-millimolar NaCl stress. Finally, the mechanisms of altered salt tolerance in LS-02 were revealed through comparative transcriptomics, and ORF25 and ORF26 on Syn-A-4-8 turned out to be the key genes causing the phenotype. Our research represents an important attempt in designing artificial cyanophages towards multiple hosts, and offers new future insights into the control of cyanobacterial blooms. [ABSTRACT FROM AUTHOR]

The study of secretory protein kinase is an emergent research field in recent years. The secretion phenomenon of type II cGMP‐dependent protein kinase (PKG II) was found in our latest research and our previous study confirmed that PKG II inhibited platelet‐derived growth factor receptor β (PDGFRβ) activation induced by platelet‐derived growth factor BB (PDGF‐BB) within the gastric cancer cells. Thus, this study was designed to investigated effect of secretory PKG II on PDGFRβ. Transwell assay and CCK8 assay indicated that secretory PKG II reversed PDGF‐BB‐induced cell migration, invasion, and proliferation. Immunoprecipitation, GST pull down and Western blotting results showed that secretory PKG II combined with extracellular domains of PDGFRβ and phosphorylated it, and thereby inhibited PDGF‐BB‐induced activation of PDGFRβ, and downstream PI3K/Akt and MAPK/ERK pathways. Mutation at Ser254 of PDGFRβ to alanine abolished the above inhibitory effects of secretory PKG II on PDGFRβ, indicating that Ser254 was the specific site phosphorylated by secretory PKG II. In conclusion, secretory PKG II inhibited PDGFRβ activation via Ser254 site. [ABSTRACT FROM AUTHOR]

DNA methylation (mainly at 5-methylcytosine, 5mC) plays an essential role in embryonic development and cellular biology. Alterations in DNA methylation are associated with disease development, especially hematologic malignancies. To investigate the potential of 5mC for diagnosis and treatment, accurate determination of 5mC is essential. Standard bisulfite sequencing-based methodologies or various optical/electrochemical biosensors for identifying 5mC have limitations, such as high cost, severe DNA degradation, over-estimation of the true 5mC level, being able to only display the average 5mC level, etc. Here we propose a single-molecule strategy for the direct identification of whole-genome 5mC by the combination of DNA fiber-based fluorescence in situ hybridization (DNA fiber FISH) and atomic force microscopy (AFM). Using extended DNA fibers and anti-5mC antibody for the detection of 5mC, it is possible to map the physical location of 5mC within the genome DNA. Together with AFM, this method can present the morphology of anti-5mC-DNA complexes and detailed spacing distribution of two neighboring 5mC sites on a single DNA molecule. Furthermore, this approach can be used for reporting other epigenetic modifications, not limited to 5mC or one single epigenetic modification. It can be anticipated to contribute to the development of clinical diagnosis of epigenetic-related diseases. [ABSTRACT FROM AUTHOR]

The low-rank matrix completion problem is fundamental in both machine learning and computer vision fields with many important applications, such as recommendation system, motion capture, face recognition, and image inpainting. In order to avoid solving the rank minimization problem which is NP-hard, several surrogate functions of the rank have been proposed in the literature. However, the matrix restored from the optimization problem based on the existing surrogate functions seriously deviates from the original one. In this paper, we first design a new non-convex Schatten capped $p$ p norm which generalizes several existing non-convex matrix norms and balances between the rank and the nuclear norm of the matrix. Then, a matrix completion method based on the Schatten capped $p$ p norm is proposed by exploiting the framework of the alternating direction method of multipliers. Meanwhile, the Schatten capped $p$ p norm regularized least squares subproblem is analyzed in detail and is solved explicitly. Finally, we evaluate the performance of the proposed matrix completion method based on extensive experiments in the field of image inpainting. All the experimental results demonstrate that the proposed method can indeed improve the accuracy of matrix completion compared with the existing methods. [ABSTRACT FROM AUTHOR]

The hydrolysis properties of lipase in castor was evaluated using two different substrate forms (tripalmitic glycerides and trioleic glycerides) to catalyze the reaction under different operational conditions. RcLipase was obtained from castor seeds and results show that RcLipase is a conservative serine lipase with a conserved catalytic center (SDH) and a conserved pentapeptide (GXSXG). This enzyme exhibited the greatest activity and tolerance to chloroform and toluene when it was expressed in Pichia pastoris GS115 at 40 ℃ and pH 8.0. Zn and Cu ions exerted obvious inhibitory effects on the enzyme, and displayed good hydrolytic activity for long-chain natural and synthetic lipids. HPLC analysis showed that this enzyme has 1,3 regioselectivity when glycerol tripalmitate and oleic acid are used as substrates. The fatty acid composition in the reaction product was 21.3% oleic acid and 79.1% sn-2 palmitic acid. [ABSTRACT FROM AUTHOR]

The deep sea remains the largest unknown territory on Earth because it is so difficult to explore1–4. Owing to the extremely high pressure in the deep sea, rigid vessels5–7 and pressure-compensation systems8–10 are typically required to protect mechatronic systems. However, deep-sea creatures that lack bulky or heavy pressure-tolerant systems can thrive at extreme depths11–17. Here, inspired by the structure of a deep-sea snailfish15, we develop an untethered soft robot for deep-sea exploration, with onboard power, control and actuation protected from pressure by integrating electronics in a silicone matrix. This self-powered robot eliminates the requirement for any rigid vessel. To reduce shear stress at the interfaces between electronic components, we decentralize the electronics by increasing the distance between components or separating them from the printed circuit board. Careful design of the dielectric elastomer material used for the robot’s flapping fins allowed the robot to be actuated successfully in a field test in the Mariana Trench down to a depth of 10,900 metres and to swim freely in the South China Sea at a depth of 3,224 metres. We validate the pressure resilience of the electronic components and soft actuators through systematic experiments and theoretical analyses. Our work highlights the potential of designing soft, lightweight devices for use in extreme conditions.A free-swimming soft robot inspired by deep-sea creatures, with artificial muscle, power and control electronics spread across a polymer matrix, successfully adapts to high pressure and operates in the deep ocean. [ABSTRACT FROM AUTHOR]

The tetrazole-based photoclick chemistry has attracted considerable attention in virtue of its good biocompatibility, exclusive molecular reaction, and spatiotemporally controllable properties. Using this photoclick reaction, we designed an in situ, real-time fluorescence imaging system that targeted mitochondria and lysosomes in a spatiotemporally controllable manner. Upon irradiation, the pyrazoline fluorophore was generated in situ by the intramolecular tetrazole-alkene cycloaddition reaction ("photo-click chemistry"). This strategy exhibits features such as fast response, high efficiency, strong fluorescence intensity without background and superior stability. In addition, by integrating with an organelle-specific group, it has a good application for subcellular targeting imaging. Furthermore, the photo-responsive moiety Tet facilitates the probes, Mt-Tet and Ly-Tet, for the super-resolution imaging of subcellular structures. [ABSTRACT FROM AUTHOR]

Summary: It is well known that virtual network (VN) embedding (VNE) aims to solve how to efficiently allocate physical resources to a VN. However, this issue has been proved to be an NP‐hard problem. Besides, as most of the existing approaches are based on heuristic algorithms, which is easy to fall into local optimal. To address the challenge, we formalize the problem as a mixed integer programming problem and propose a novel VNE method based on reinforcement learning in this article. And to solve the problem, we introduce a pointer network to generate virtual node mapping strategies through an attention mechanism, and design a reward function related to link resource consumption to build the connection between node mapping and link mapping stages of VNE. In addition, we present a policy gradient optimization mechanism to leverage the reward information obtained from the sampled solutions, and design an active search based process to automatically update the parameters of the neural network and to obtain near‐optimal embedding solution. The experimental results show that the proposed method can improve the performance in average physical node utilization and long‐term revenue to cost ratio comparing than that of the existing models. [ABSTRACT FROM AUTHOR]

Castor (Ricinus communis L.) is one of the world's top ten oil crops. China is the second largest producer of castor beans, but China's castor bean acreage has been declining. A principal reason for this decline is the prevalence of weeds and the absence of herbicide resistant varieties of castor plants. In this study, we used Agrobacterium-mediated gene transfer to introduce the EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) gene, which confers resistance to glyphosate, and the Bar (phosphinothricin N-acetyltransferase) gene, encoding resistance to glufosinate, into castor 2129 (high stem excellent recovery line) and CSR 181 (dwarf stem excellent recovery line). The transgenic plants exhibited significantly increased expression of the EPSPS and Bar genes and significantly increased resistance to glyphosate and glufosinate. Proteomic analysis showed differences in the amounts of 20 proteins in the dwarf stem transgenic plants. Nine of these proteins are involved in photosynthesis and indirectly related to the mechanism of action of the Bar gene. Eight proteins are involved in defense, repair, stress response, oxidative phosphorylation, and metabolic pathways and are indirectly related to the mechanism of action of the EPSPS gene. These results provide a foundation for the preparation of high herbicide resistant castor varieties. [ABSTRACT FROM AUTHOR]

Objective: To prepare NLG919-loaded breast cancer-targeting nanomicelles,so as to improve water solubility and targeting ability of NLG919,and also to investigate the characteristics of nanomicelles in vitro. Methods :The cholesterol-modified peptide monomer CHL was synthesized by solid phase synthesis. NLG919-CHL nanomicelles were prepared by dialysis method .Particle sizes were measured by dynamic light scattering, and critical micelle concentration was investigated by pyrene fluorescein probe .Laser confocal technique was used to investigate the intracellular distribution of cells. Cytotoxicity of nanomicelles to tumor cells 4T1 of mouse breast cancer and tumor cells MCF-7 of human breast cancer were determined,and activity inhibition of indoleamine 2,3-dioxygenase(IDO ) in tumor cells were also investigated .Results :NLG919-CHL nanomicelles were successfully prepared by dialysis method .The drug loading rate and encapsulation efficiency of micelles reached as high as (21 .04±0 .002 )% and (63 .30± 0 .011 )%,respectively . The results of cytotoxicity experiment showed that the cell viability of 4T1 and MCF-7 cells was still above 85/o when it was cultured with the BlankCHL at the concentration of 200 fig/ml for 24 hours . The results of confocal experiment indicated that the nanomicelles could carry the drug into cells. Conclusion : The successful construction of NLG919-loaded nanomicelles might promise a low-toxic,breast cancer-targeted drug delivery system . [ABSTRACT FROM AUTHOR]

The manufacture of 3D mesostructures is receiving rapidly increasing attention, because of the fundamental significance and practical applications across wide-ranging areas. The recently developed approach of buckling-guided assembly allows deterministic formation of complex 3D mesostructures in a broad set of functional materials, with feature sizes spanning nanoscale to centimeter-scale. Previous studies mostly exploited mechanically controlled assembly platforms using elastomer substrates, which limits the capabilities to achieve on-demand local assembly, and to reshape assembled mesostructures into distinct 3D configurations. This work introduces a set of design concepts and assembly strategies to utilize dielectric elastomer actuators as powerful platforms for the electro-mechanically controlled 3D assembly. Capabilities of sequential, local loading with desired strain distributions allow access to precisely tailored 3D mesostructures that can be reshaped into distinct geometries, as demonstrated by experimental and theoretical studies of ∼30 examples. A reconfigurable inductive–capacitive radio-frequency circuit consisting of morphable 3D capacitors serves as an application example. [ABSTRACT FROM AUTHOR]

Hepatitis B virus (HBV) exploits multiple strategies to evade host immune surveillance. Programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) signaling plays a critical role in regulating T cell homeostasis. However, it remains largely unknown as to how HBV infection elevates PD-L1 expression in hepatocytes. A mouse model of HBV infection was established by hydrodynamic injection with a vector containing 1.3-fold overlength HBV genome (pHBV1.3) via the tail vein. Coculture experiments with HBV-expressing hepatoma cells and Jurkat T cells were established in vitro. We observed significant decrease in the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) and increase in β-catenin/PD-L1 expression in liver tissues from patients with chronic hepatitis B and mice subjected to pHBV1.3 hydrodynamic injection. Mechanistically, decrease in PTEN enhanced β-catenin/c-Myc signaling and PD-L1 expression in HBV-expressing hepatoma cells, which in turn augmented PD-1 expression, lowered IL-2 secretion, and induced T cell apoptosis. However, β-catenin disruption inhibited PTEN-mediated PD-L1 expression, which was accompanied by decreased PD-1 expression, and increased IL-2 production in T cells. Luciferase reporter assays revealed that c-Myc stimulated transcriptional activity of PD-L1. In addition, HBV X protein (HBx) and HBV polymerase (HBp) contributed to PTEN downregulation and β-catenin/PD-L1 upregulation. Strikingly, PTEN overexpression in hepatocytes inhibited β-catenin/PD-L1 signaling and promoted HBV clearance in vivo. Our findings suggest that HBV-triggered PTEN/β-catenin/c-Myc signaling via HBx and HBp enhances PD-L1 expression, leading to inhibition of T cell response, and promotes HBV immune evasion. NEW & NOTEWORTHY This study demonstrates that during HBV infection, HBV can increase PD-L1 expression via PTEN/β-catenin/c-Myc signaling pathway, which in turn inhibits T cell response and ultimately promotes HBV immune evasion. Targeting this signaling pathway is a potential strategy for immunotherapy of chronic hepatitis B. [ABSTRACT FROM AUTHOR]

Ricinoleic acid, one of the biggest components in castor oil, is an unusual fatty acid with numerous industrial applications. Despite much research on the oil content of Ricinus communis L., the genes encoding the oil biosynthesis function in the seed developmental stages are still poorly known. Here, we analyzed differentially expressed transcripts during seed development using cDNA-amplified fragment length polymorphism. Almost all ingredients significantly decreased along with seed maturation, except for ricinoleic acid, which increased greatly from 6.7% to 86.8%. A total of 534 distinguished fragments were differentially expressed in six development stages. Among these, 67 fragments showed high homology with known-function genes, and 26 sequences were successfully annotated with fatty acid synthesis or storage proteins in castor and other species. The results showed that fatty acid synthesis and accumulation in castor seeds displayed various temporal patterns. Different cDNA-fragment patterns were mainly found in later development stages, coinciding with the onset of oil synthesis. [ABSTRACT FROM AUTHOR]

The paper proposes a novel signal reconstruction algorithm through substituting the gradient descent method in the iterative hard thresholding algorithm with a faster sparse randomized Kaczmarz method. By designing a series of gradually attenuated weights for the matrix rows whose indexes lie outside of the support set of the original sparse signal, we can focus the iterations on the effective support rows of the measurement matrix. The experiment results show that the proposed algorithm presents a faster convergence rate and more accurate reconstruction accuracy than the state-of-the-art algorithms. Meanwhile, the successful reconstruction probability of the proposed algorithm is higher than that of other algorithms. Moreover, the characteristics of the proposed signal reconstruction algorithm are also analyzed in detail through numerical experiments. [ABSTRACT FROM AUTHOR]

DNA methylation plays an important role in endosperm development and is involved in the epigenetic regulation of gene expression. However, the epigenetic regulation of castor seed development has not yet been reported. In this study, methylation-sensitive amplification polymorphism (MSAP) analysis was used to investigate the methylation level in castor. In 20-day-old castor seeds, 41.17% of the fragments were fully methylated and 15.61% were hemimethylated. In 60 day-old seed, the full methylation and hemimethylation rates were 19.77% and 7.56%, respectively, suggesting that some methylation level changes existed during the castor seed development. A total of 647 bands were identified with different methylation or demethylation patterns during the seed maturation. However, only 37 sequences were homologous to well-known proteins, such as phospholipid-transporting ATPase, phosphatases and methyltransferase. Therefore, these results clearly demonstrated that the MSAP technique is very useful for the analysis of the global DNA methylation state in castor and the complexity of DNA methylation changes during seed development. The different methylation levels may be correlated with the specific gene expression in different seed development stages. [ABSTRACT FROM AUTHOR]

KAl (7075) alloy /Mg (AZ31) alloy laminated composite plates were successfully fabricated by the equal channel angular processing (ECAP) by using route A for 1, 2, and 3 passes at 573 K, respectively. After fabrication, the 1-pass ECAPed laminated composite plates were annealed at different temperatures. The microstructure evolution, phase constituent, and bonding strength near the joining interface of Al (7075) alloy /Mg (AZ31) alloy laminated composites plates were evaluated with scanning electron microscopy, X-ray diffraction, and shear tests. The experimental results indicated that a 20 μm diffusion layer was observed at the joining interface of Al (7075) alloy /Mg (AZ31) alloy laminated composites plates fabricated by the 1-pass ECAP, which mainly included AlMg and MgAl phases. With the increase of passes, the increase of diffusion layer thickness was not obvious and the form of crack in these processes led to the decrease of bonding strength. For 1-pass ECAPed composites, the thickness of diffusion layer remained unchanged after annealed at 473 K, while the bonding strength reached its maximum value 29.12 MPa. However, after elevating heat treatment temperature to 573 K, the thickness of diffusion layer increased rapidly, and thus the bonding strength decreased. [ABSTRACT FROM AUTHOR]

In multisink wireless sensor networks, synchronized data collection among multiple sinks is a significant and challenging task. In this paper, we propose an unbalanced threshold based distributed data collection scheme to reconstruct the synchronized sensed data of the whole sensor network in all sinks. The proposed scheme includes the unbalanced threshold based distributed top-K query algorithm and the distributed iterative hard thresholding algorithm. By computing unbalanced thresholds and pruning unnecessary element exchanging, each sink can synchronize the top-K aggregated values efficiently via the unbalanced threshold based distributed top-K query algorithm. After that, the synchronized sensed data of the whole sensor network can be reconstructed through the distributed iterative hard thresholding algorithm in a distributed and cooperative manner. We show through experiments that the proposed scheme can reduce the interaction times and decrease the number of transmitted data and that of computed data compared to the existing schemes while maintaining the similar data reconstruction accuracy. The communication and computational performances of the proposed scheme are also analyzed in detail in the paper. [ABSTRACT FROM AUTHOR]

Based on its large deformation, light weight, and high energy density, dielectric elastomer (DE) has been used as driven muscle in many areas. We design the fiber-reinforced DE membrane by adding fibers in the membrane. The deformation and driven force direction of the membrane can be tuned by changing the fiber arrangements. The actuation in the perpendicular direction of the DE membrane with long fibers first increases and then decreases by the increasing of the fiber spacing in the perpendicular direction. The horizontal actuation of the membrane decreases by decreasing the spacing of short fibers. In the membrane-inflating structure, the radially arranged fibers will break the axisymmetric behavior of the structure. The top area of the inflated balloon without fiber will buckle up when the voltage reaches a certain level. Finite element simulations based on nonlinear field theory are conducted to investigate the effects of fiber arrangement and verify the experimental results. This work can guide the design of fiber-reinforced DE. [ABSTRACT FROM AUTHOR]

We propose a three-phase top-k query based distributed data collection scheme which is designed for clustered or multisink wireless sensor networks. The proposed scheme consists of a distributed iterative hard thresholding algorithm and a three-phase top-k query algorithm. In the distributed iterative hard thresholding algorithm, the cluster heads or sink nodes reconstruct the compressed data in a distributed and cooperative manner. Meanwhile, the top-k query operation in the above algorithm is realized by pruning unnecessary elements among cluster heads or sink nodes in the three-phase top-k query algorithm. Simulation results show that there is no obvious difference in the performance of data reconstruction between our proposed scheme and existing compressive sensing theory based data collection schemes. However, both the number of interactions and the amount of transmitted data among cluster heads or sink nodes can be effectively reduced in the proposed scheme. The performance of the proposed scheme is analyzed in detail in this paper to support the claims. [ABSTRACT FROM AUTHOR]

Purpose – The purpose of this paper is to present a novel concentration estimation model for improving the accuracy and robustness of low-cost electronic noses (e-noses) with metal oxide semiconductor sensors in indoor air contaminant monitoring and overcome the potential sensor drift. Design/methodology/approach – In the quantification model, a piecewise linearly weighted artificial neural network ensemble model (PLWE-ANN) with an embedded self-calibration module based on a threshold network is studied. Findings – The nonlinear estimation problem of sensor array-based e-noses can be effectively transformed into a piecewise linear estimation through linear weighted neural networks ensemble activated by a threshold network. Originality/value – In this paper, a number of experimental results have been presented, and it also demonstrates that the proposed model has very good accuracy and robustness in real-time indoor monitoring of formaldehyde. [ABSTRACT FROM AUTHOR]

We report a new class of deubiquitinating enzyme (DUB) probes that resemble the native diubiquitin with a same linkage size and contain a Michael addition acceptor for trapping the DUB active-site cysteine. Both K63- and K48-linked diubiquitin probes were generated using a facile chemical ligation method. The diUb probes were demonstrated to label DUBs from different families and revealed intrinsic linkage specificities of DUBs. [ABSTRACT FROM AUTHOR]

Exosomes (Exo) hold great promise as endogenous nanocarriers that can deliver biological information between cells. However, Exo are limited in terms of their abilities to target specific recipient cell types. We developed a strategy to isolate Exo exhibiting increased binding to integrin αvβ3. Binding occurred through a modified version of a disintegrin and metalloproteinase 15 (A15) expressed on exosomal membranes (A15-Exo), which facilitated co-delivery of therapeutic quantities of doxorubicin (Dox) and cholesterol-modified miRNA 159 (Cho-miR159) to triple-negative breast cancer (TNBC) cells, both in vitro and in vivo. The targeted A15-Exo were derived from continuous protein kinase C activation in monocyte-derived macrophages. These cell-derived Exo displayed targeting properties and had a 2.97-fold higher production yield. In vitro, A15-Exo co-loaded with Dox and Cho-miR159 induced synergistic therapeutic effects in MDA-MB-231 cells. In vivo, miR159 and Dox delivery in a vesicular system effectively silenced the TCF-7 gene and exhibited improved anticancer effects, without adverse effects. Therefore, our data demonstrate the synergistic efficacy of co-delivering miR159 and Dox by targeted Exo for TNBC therapy. [ABSTRACT FROM AUTHOR]