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The quest for realizing and manipulating ever smaller man-made movable structures and dynamical machines has spurred tremendous endeavors, led to important discoveries, and inspired researchers to venture to previously unexplored grounds. Scientific feats and technological milestones of miniaturization of mechanical structures have been widely accomplished by advances in machining and sculpturing ever shrinking features out of bulk materials such as silicon. With the flourishing multidisciplinary field of low-dimensional nanomaterials, including one-dimensional (1D) nanowires/nanotubes and two-dimensional (2D) atomic layers such as graphene/phosphorene, growing interests and sustained effort have been devoted to creating mechanical devices toward the ultimate limit of miniaturization/genuinely down to the molecular or even atomic scale. These ultrasmall movable structures, particularly nanomechanical resonators that exploit the vibratory motion in these 1D and 2D nano-to-atomic-scale structures, offer exceptional device-level attributes, such as ultralow mass, ultrawide frequency tuning range, broad dynamic range, and ultralow power consumption, thus holding strong promises for both fundamental studies and engineering applications. In this Review, we offer a comprehensive overview and summary of this vibrant field, present the state-of-the-art devices and evaluate their specifications and performance, outline important achievements, and postulate future directions for studying these miniscule yet intriguing molecular-scale machines., ACS Nano, 16 (10), ISSN:1936-0851, ISSN:1936-086X

Background Longxuetongluo capsule (LTC), derived from the total phenolic compounds of Chinese dragon's blood, is now used in the treatment of ischemic stroke in convalescence. The aim of this study is to explore the neuroprotective effect of LTC from the perspective of neuroinflammation. Methods Cell viability and lactate dehydrogenase (LDH) release were measured by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) and LDH assay kit. Proinflammatory mediators and cytokines production including Nitric Oxide (NO), prostaglandin E2, (PGE2), interleukin (IL-β), IL-6, and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA) assay. In addition, western blot was used to detect the expression of inflammatory proteins associated with the mitogen-activated protein kinases (MAPKs), janus kinase/signal transducer and activator of tranions (JAK/STAT), nuclear transcription factor κB (NF-κB), and nuclear factor erythroid-2-related actor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathways. Moreover, immunofluorescence assay and electrophoretic mobility shift assays (EMSA) were performed to determine the Nrf2 translocation and the binding-DNA activity of NF-κB, respectively. Results LTC at 0.5 to 2 μg/mL significantly increased cell viability and decreased LDH, NO, PGE2, IL-1β, IL-6, and TNF-α production in oxygen-glucose deprivation/reoxygenation (OGD/R) and lipopolysaccharide (LPS)-induced BV2 microglia cells. Meanwhile, LTC not only decreased the protein expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) but also down-regulated phosphorylation of extracellular signal-regulated kinase (ERK)1/2, p38, and up-regulated HO-1 expression via nuclear translocation of Nrf2. LTC can significantly inhibit the phosphorylation of JAK1/STAT3 and reduce the translocation of NF-κB from cytosol to nucleus as well as the binding-DNA activity. PC12 cell pretreated with LTC-condition medium (CM) significantly alleviated LPS-induced neurotoxicity and increased PC12 cell viability in a dose-dependent manner. Conclusion The present study showed that LTC exhibited a strong antineuroinflammatory activity and neuroprotective effects on LPS-stimulated BV2 microglial cells and PC12 cells.

The prediction of host human miRNA binding to the SARS-COV-2-CoV-2 RNA sequence is of particular interest. This biological process could lead to virus repression, serve as biomarkers for diagnosis, or as potential treatments for this disease. One source of concern is attempting to uncover the viral regions in which this binding could occur, as well as how these miRNAs binding could affect the SARS-COV-2 virus's processes. Using extracted sequence features from this base pairing, we predicted the relationships between miRNAs that interact with genes involved in immune function and bind to the SARS-COV-2 genome in their 5' UTR region. We compared two supervised models, SVM and Random Forest, with an unsupervised One-Class SVM. When the results of the confusion matrices were inspected, the results of the supervised models were misleading, resulting in a Type II error. However, with the latter model, we achieved an average accuracy of 92%, sensitivity of 96.18%, and specificity of 78%. We hypothesize that studying the bind of miRNAs that affect immunological genes and bind to the SARS-COV-2 virus will lead to potential genetic therapies for fighting the disease or understanding how the immune system is affected when this type of viral infection occurs.

As computer networks keep growing at a high rate, achieving confidentiality, integrity, and availability of the information system is essential. Intrusion detection systems (IDSs) have been widely used to monitor and secure networks. The two major limitations facing existing intrusion detection systems are high rates of false-positive alerts and low detection rates on zero-day attacks. To overcome these problems, we need intrusion detection techniques that can learn and effectively detect intrusions. Hybrid methods based on machine learning techniques have been proposed by different researchers. These methods take advantage of the single detection methods and leverage their weakness. Therefore, this paper reviews 111 related studies in the period between 2012 and 2022 focusing on hybrid detection systems. The review points out the existing gaps in the development of hybrid intrusion detection systems and the need for further research in this area.

Additional file 1: Figure S1. The logos represented the 10 conserved motifs of CBF proteins, which were derived from MEME Suite. Figure S2. The subcellular localization of CsCBF1, CsCBF2 and CsCBF3 proteins were predicted using PredictProtein software, which were all located in the nucleus. Figure S3. Expression levels of CsCBF1, CsCBF2 and CsCBF3 in 35S:CsCBFs transgenic plants.

Since the hydraulic power take-off (PTO) is a widely-utilized transmission device for oscillating-body wave energy converters, its parameter configurations need to be optimized with an accurate dynamic model. To accurately describe the cylinder friction force, the motor loss and the accumulator working patterns, this paper establishes a novel nonlinear state space model for a hydraulic PTO. The model contains a stiction-involved Stribeck curve for the hydraulic cylinder, an improved Jeong's theory for the hydraulic motor and a pressure-bound-related formula for the high-pressure accumulator. The proposed model is simulated in irregular waves and verified via the comparison with the WEC models based on Yang's theory [1]. Furthermore, the research focuses on obtaining optimal PTO parameter configurations with the suitable piston area and resistance, according to the generating ability, energy conversion efficiency and pressure stability. The results show that the piston area has a more significant impact on the generating ability and pressure stability than the resistance but the same influence on the energy conversion efficiency. In general, a small piston area and a minor resistance are the superior configurations at the fixed capacity.

In this paper, we propose two new nonblocking properties of automata as quantitative measures of maximal distances to marker states. The first property, called {\em quantitative nonblockingness}, captures the practical requirement that at least one of the marker states (representing e.g. task completion) be reachable within a prescribed number of steps from any non-marker state and following any trajectory of the system. The second property, called {\em heterogeneously quantitative nonblockingness}, distinguishes individual marker states and requires that each marker state be reached within a given bounded number of steps from any other state and following any trajectory of the system. Accordingly, we formulate two new problems of quantitatively nonblocking supervisory control and heterogeneously quantitatively nonblocking supervisory control, and characterize their solvabilities in terms of new concepts of quantitative language completability and heterogeneously quantitative language completability, respectively. It is proved that there exists the unique supremal (heterogeneously) quantitatively completable sublanguage of a given language, and we develop effective algorithms to compute the supremal sublanguages. Finally, combining with the algorithm of computing the supremal controllable sublanguage, we design algorithms to compute the maximally permissive solutions to the formulated (heterogeneously) quantitatively nonblocking supervisory control problems.

Background: The self-rooted seedling is widely used in pomegranate planting industry currently; However, the root system of self-rooted seedling is shallow and poor cold resistance. Therefore, the study of the molecular mechanisms of pomegranate adventitious root gravitropism is very important for developing deep-rooted pomegranate cultivars.Results: We report the pomegranate FOUR LIPS (PgFLP) that play an key role in regulating the gravitropic set-point angle of pomegranate adventitious root in response to gravity signal. In our study, PgFLP directly regulates the transcriptional expression of PgPIN10 by binding to its promoter, thus regulating the GSA of adventitious root in pomegranate. Additionally, the 35S::PgFLP show stronger gravitational response than wild-type, leading to a smaller GSA in Arabidopsis lateral roots, indicating that PgFLP participates in regulating the GSA of adventitious root via PgPIN10 in pomegranate. Conclusion: Our results confirm that the transcriptional regulation of PgPIN10 by R2R3-MYB transcription factor PgFLP in setting the gravitropic set-point angle of pomegranate adventitious root in response to gravity signal.

Uniaxial tensile tests were conducted to investigate the plastic deformation behavior and deformation microstructures of coarse-grained Cu-Ni alloys containing a wide range of Ni contents (5–20 at%), which possess higher stacking fault energies (SFE) than pure Cu. The mechanical testing results show that, with increasing Ni content, i.e., jointly increasing SFE and degree of short range clustering (SRC), the ultimate tensile strength increases, but the ductility keeps almost unchanged; meanwhile, there exists an obvious increasing stage (or “bump”) in the strain-hardening rate curves at around 3% engineering strain. Microstructural examinations demonstrate that dislocations are apt to slip on primary slip planes at the initial stage of deformation (e.g., 3% engineering strain) to form planar slip bands, indicating that the existence of SRCs in Cu-Ni alloys is beneficial to the promotion of planar slip, leading to the occurrence of a “bump” phenomenon in the strain-hardening rate curves. With increasing deformation amount to a certain degree, wavy slip becomes the major deformation mode under the joint influence of high SFE and diminution of SRCs, and the final deformation microstructures transform from dislocation cells and cell blocks into extended dislocation walls with increasing Ni content. Both the cell block structures and extended dislocation walls subdivide the coarse grains uniformly to disperse local strain concentration, thus enabling the Cu-Ni alloys to maintain a high ductility with an increased tensile strength with increasing Ni content. In a word, the plastic deformation behavior of Cu-Ni alloys is actually governed by the competitive influence of SRC and SFE.

Background The close planting of dwarfing self-rooted rootstocks is currently a widely used method for apple production; however, self-rooted rootstocks are weak with shallow roots and poor grounding. Therefore, understanding the molecular mechanisms that establish the gravitropic set-point angles (GSAs) of the adventitious roots of self-rooted apple stocks is important for developing self-rooted apple rootstock cultivars with deep roots. Results We report that the apple FOUR LIPS (MdFLP), an R2R3-MYB transcription factor (TF), functions in establishing the GSA of the adventitious roots of self-rooted apple stocks in response to gravity. Biochemical analyses demonstrate that MdFLP directly binds to the promoters of two auxin efflux carriers, MdPIN3 and MdPIN10, that are involved in auxin transport, activates their transcriptional expression, and thereby promotes the development of adventitious roots in self-rooted apple stocks. Additionally, the apple auxin response factor MdARF19 influences the expression of those auxin efflux carriers and the establishment of the GSA of adventitious roots of apple in response to gravity by directly activating the expression of MdFLP. Conclusion Our findings provide new insights into the transcriptional regulation of MdFLP by the auxin response factor MdARF19 in the regulation of the GSA of adventitious roots of self-rooted apple stocks in response to gravity. Electronic supplementary material The online version of this article (10.1186/s12870-019-1847-2) contains supplementary material, which is available to authorized users.

In the field of computer vision, multi-class outdoor weather classification is a difficult task to perform due to diversity and lack of distinct weather characteristic or features. This research proposed a novel framework for identifying different weather scenes from still images using heterogeneous ensemble methods. Our approach is based on a method called Selection Based on Accuracy Intuition and diversity (SAID) of stacked ensemble algorithms. This involves the extraction of histogram of features from different weather scenes. The blending and boosting of different weather features using stacked ensemble algorithms increases recognition rate of different weather conditions compared to other classification and ensemble methods. The paper presents academic and practitioners a new insight into diversity of heterogeneous ensemble methods for solving the challenges of weather recognition from still images.

Compared with 9%Ni steel, low nickel steel has great advantages in cost and weldability. However, cryogenic toughness of the heat affected zone (HAZ) of conventional low nickel steel deteriorates, which limits its application in the construction of liquefied natural gas tanks. In this work, two low nickel steels with different Si contents were designed, and the relationship between Si content and HAZ cryogenic toughness of these steel samples was investigated. After reducing Si content, the required Charpy impact absorbed energy was obtained in the HAZ at fusion line and 1 mm from fusion line. Microstructural characterization revealed that the reduction in Si content promoted auto-tempering of coarse-grained HAZ (CGHAZ), leading to improved plastic deformation ability of the matrix. In intercritically reheated CGHAZ (ICCGHAZ), martensite-austenite (M-A) constituents were formed, which consisted of twin martensite and austenite. The decrease in Si content reduced the amount and size of M-A constituents and changed their elongated morphology to blocky morphology, which is also believed to be beneficial for ICCGHAZ cryogenic toughness. This work provides a novel way to soften the HAZ microstructure for improving its cryogenic toughness.

With the development of the measurement technology, the magnetostrictive liquid level sensor has attracted more and more attention with its outstanding properties. This paper proposes a design plan for magnetostrictive liquid level sensor with the FPGA micro controller, bring a brief introduction of the advantages of the FPGA micro controller and the circuit design theory of the magnetostrictive liquid level sensor, which has great results  in the experiments.

In the apple industry, the improvement of apple fruit aroma and polyphenol content has always been an important goal of breeding. In this study, pollination experiments of ‘Yan 3 Fuji’, ‘Indo’ and ‘Ryokano kisetsu’ apples were carried out by using pollen grains of quince (Cydonia oblonga Mill.). The results indicated that single fruit weight, fruit firmness, vitamin C content, sugar-acid ratio, total phenolics and total flavonoids were significantly affected by quince pollen, while quince pollen had no significant effect on fruit shape index, titration acid and total anthocyanins. In addition, valuable phenolic compounds, including catechin, epicatechin, chlorogenic acid, phloridzin, quercetin, and quercetin 3-D-galactoside, were significantly influenced by quince pollen. Moreover, esters such as acetic acid pentyl ester, acetic acid hexyl ester, butanoic acid hexyl ester, butanoic acid-2-methyl- hexyl ester and hexanoic acid hexyl ester in three kinds of apple were all increased after pollination by quince. Obvious metaxenia was observed between quince pollen and apple.

In this research work, a novel spatial parallel manipulator with three degrees of freedom (DOF) is proposed. The moving platform has two-translation and one-rotational DOFs with respect to the fixed base. Based on the position and orientation characteristics (POC) theory, the number of the DOF is computed and the output motion characteristics of the parallel mechanism are analyzed. The formulas for solving position and orientation of the platform are derived. By using the kinematic influence coefficient method, solutions of the forward/inverse velocity and acceleration are derived. The virtual prototype model of the 2T1R parallel manipulator is established by use of Pro/E software. At last, the position, velocity and acceleration curves are described based on ADAMS software.

Non-equilibrium molecular dynamics approach is adopted to simulate the out-of-plane thermal conductivity of nanometer silicon film. The simulation results reveal that the out-of-plane thermal conductivity of nanometer silicon film is significantly lower than the bulk value and decreases with the decrement of film thickness. From the simulation results, the thermal conductivity variation tendency changes near the 20 nm. With the increase of film thickness, phonon mean free path is not a fixed value. Attributing the thermal conductivity size effect to be phonon-boundary scattering the theoretical analysis of the thermal conductivity has been performed using the Boltzmann transport equation and Holland model. The thermal conductivity theoretical results agree well with the results of molecular dynamics simulation, which indicates that the phonon mean free path in nanometer silicon films is significantly decreased.

Experiment data got from onset of nucleate boiling (ONB) in natural circulation is analyzed using unascertained mathematics. Unitary mathematics model of the relation between the temperature and onset of nucleate boiling is built up to analysis ONB. Multiple unascertained mathematics models are also built up with the onset of natural circulation boiling equation based on the experiment. Unascertained mathematics makes that affirmative results are a range of numbers that reflect the fluctuation of experiment data more truly. The fluctuating value with the distribution function F(x) is the feature of unascertained mathematics model and can express fluctuating experimental data. Real status can be actually described through using unascertained mathematics. Thus, for calculation of ONB point, the description of unascertained mathematics model is more precise than common mathematics model. Based on the unascertained mathematics, a new ONB model is developed, which is important for advanced reactor safety analysis. It is conceivable that the unascertained mathematics could be applied to many other two-phase measurements as well.

PM2.5 thermophoretic deposition efficiency in turbulent gas flowing over tube surfaces is analyzed using the new concept of potential capacity and potential capacity variation. According to Romay's model, a thermophoretic deposition efficiency model in turbulent gas flowing over tube surfaces is built up based on the potential capacity. Through computing and analyzing thermophoretic deposition efficiency, PM2.5 thermophoretic deposition efficiency in turbulent gas flowing over tube surfaces in direct ratio to the potential capacity variation and in inverse ratio to the temperature ratio of tube wall to entrance gas-particle mixture. And the imprecise notion of thermophoretic deposition efficiency direct ratio to the temperature difference between tube wall and entrance gas-particle mixture is reviewed. There are credible foundations to be provided for improving and researching thermophoretic deposition efficiency in theory and experiment.

At first the relationship between the volume of the data transmitted and the transmission time is tested and the analysis of the data shows that there is a significant linear relationship between the two in MATLAB Distributed Computing Engine. Then we give an implementation solution of the parallel ant colony optimization algorithm, and we also carried on the computation of a TSP example which shows a higher speedup and a better performance. All these show that the it is efficient and effective to use MATLAB to develop distributed computing application program.

A suspended carbon nanotube can act as a nanoscale resonator with remarkable electromechanical properties and the ability to detect adsorption on its surface at the level of single atoms. Understanding adsorption on nanotubes and other graphitic materials is key to many sensing and storage applications. Here we show that nanotube resonators offer a powerful new means of investigating fundamental aspects of adsorption on carbon, including the collective behaviour of adsorbed matter and its coupling to the substrate electrons. By monitoring the vibrational resonance frequency in the presence of noble gases, we observe the formation of monolayers on the cylindrical surface and phase transitions within these monolayers, and simultaneous modification of the electrical conductance. The monolayer observations also demonstrate the possibility of studying the fundamental behaviour of matter in cylindrical geometry., Comment: Unpublished; 7 pages with 4 figures plus 3 pages of supplementary material

Many strongly correlated electronic materials, including high-temperature superconductors, colossal magnetoresistance and metal-insulator-transition (MIT) materials, are inhomogeneous on a microscopic scale as a result of domain structure or compositional variations. An important potential advantage of nanoscale samples is that they exhibit the homogeneous properties, which can differ greatly from those of the bulk. We demonstrate this principle using vanadium dioxide, which has domain structure associated with its dramatic MIT at 68 degrees C. Our studies of single-domain vanadium dioxide nanobeams reveal new aspects of this famous MIT, including supercooling of the metallic phase by 50 degrees C; an activation energy in the insulating phase consistent with the optical gap; and a connection between the transition and the equilibrium carrier density in the insulating phase. Our devices also provide a nanomechanical method of determining the transition temperature, enable measurements on individual metal-insulator interphase walls, and allow general investigations of a phase transition in quasi-one-dimensional geometry., Comment: 9 pages, 3 figures, original submitted in June 2008

Magnetic fields and electromagnetic forces have long been used to control the flow of a solidifying melt.In this study,low-frequency modulated electromagnetic stirring was provided by a helical permanent magnet stirrer,which can be considered as superposition of traveling and rotating magnetic fields.Flow behaviors of liquid metal driven by this helical magnetic field was investigated.Moreover,the rotating direction of the helical magnetic field was periodically reversed to form a modulated helical magnetic field.The helical magnetic field was constructed on some units of the permanent magnets magnetized in their radius directions.The liquid metal was driven by the Lorentz force via this rotating magnetic stirrer.The azimuthal and axial velocity distribution of liquid GaInSn alloy was quantitatively measured using an ultrasonic Doppler velocimetry(UDV),which revealed the time-dependent flow structure and flow pattern varying with the modulation parameters:the rotating speed of the magnetic stirrer and the modulation frequency.The main results of the velocity measurement of the liquid metal were as followed:the azimuthal velocity of the screw flow was periodically reversed with the same modulated frequency,and the flow intensity gradually saturated when the modulation period T_m≥40 s;the axial flow resulted from the competition of large vertical vortex driven by the traveling component of the helical magnetic field and the secondary flow driven by the rotating component of the helical magnetic field.There was a critical modulated period T_m~* with respect to the reversed characteristic and flow intensity.When T_mT_m~-,the axial velocity exhibited typically reversed flow,when T_mT_m~*,the secondary flow appeared and gradually dominated in the axial flow pattern.The prospective goals of the present study is to develop proper magnetic fields,which can generate a three-dimensional modulated metal flow in front of solidifying front to adapt the varying casting slabs.The role of electromagnetically driven flow is to transport the solute rejected by the solidifying interface at significant distances in the melt,and to periodically reverse its circulation so that macrosegregation is minimized.

This paper analyzes system's model and gives a kind of model which can be feedforward decoupled. First, get the parameters by on-line identification to proximately describe the real system. Then, the model is feedforward decoupled. Finally, using the fast algorithm, the control result is calculated. This fast algorithm not needs to compute the Diophantine equation and inverted matrices on line. The paper also present a method to reduce interaction, the simulation results show its efficiency.