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Rock creep is the result of the combined effects of many environmental conditions, such as temperature and moisture, and internal hardening and damage. In this study, we introduce a creep parameter that accounts for the joint effect of hardening and damage by using a dashpot in the Nishihara model. A modified creep model is established by connecting this dashpot to the modified Nishihara model. The modeling results agree well with the experimental creep data. The model resolves the shortcomings of the conventional spider model in describing the accelerated creep properties. The creep instantaneous model can describe the creep curve and the hardening–damage characteristics of the creep process. [ABSTRACT FROM AUTHOR]

Federated learning is a promising learning paradigm that allows collaborative training of models across multiple data owners without sharing their raw datasets. To enhance privacy in federated learning, multi-party computation can be leveraged for secure communication and computation during model training. This survey provides a comprehensive review on how to integrate mainstream multi-party computation techniques into diverse federated learning setups for guaranteed privacy, as well as the corresponding optimization techniques to improve model accuracy and training efficiency. We also pinpoint future directions to deploy federated learning to a wider range of applications. [ABSTRACT FROM AUTHOR]

Menaquinone-7 (MK-7), a subtype of vitamin K2 (VK2), assumes crucial roles in coagulation function, calcium homeostasis, and respiratory chain transmission. The production of MK-7 via microbial fermentation boasts mild technological conditions and high biocompatibility. Nevertheless, the redox activity of MK-7 imposes constraints on its excessive accumulation in microorganisms. To address this predicament, an adaptive laboratory evolution (ALE) protocol was implemented in Bacillus subtilis BS011, utilizing vitamin K3 (VK3) as a structural analog of MK-7. The resulting strain, BS012, exhibited heightened tolerance to high VK3 concentrations and demonstrated substantial enhancements in biofilm formation and total antioxidant capacity (T-AOC) when compared to BS011. Furthermore, MK-7 production in BS012 exceeded that of BS011 by 76% and 22% under static and shaking cultivation conditions, respectively. The molecular basis underlying the superior performance of BS012 was elucidated through genome and transcriptome analyses, encompassing observations of alterations in cell morphology, variations in central carbon and nitrogen metabolism, spore formation, and antioxidant systems. In summation, ALE technology can notably enhance the tolerance of B. subtilis to VK and increase MK-7 production, thus offering a theoretical framework for the microbial fermentation production of other VK2 subtypes. Additionally, the evolved strain BS012 can be developed for integration into probiotic formulations within the food industry to maintain intestinal flora homeostasis, mitigate osteoporosis risk, and reduce the incidence of cardiovascular disease. Key points: • Bacillus subtilis was evolved for improved vitamin K tolerance and menaquinone-7 (MK-7) production • Evolved strains formed wrinkled biofilms and elongated almost twofold in length • Evolved strains induced sporulation to improve tolerance when carbon was limited [ABSTRACT FROM AUTHOR]

Interpolating non-uniform rational B-spline (NURBS) curves often leads to undesirable feedrate fluctuations due to the non-analytic relationship between the spline parameter and arc length. In this paper, we introduce a feedback method that effectively reduces feedrate fluctuations while maintaining simplicity in the interpolation process. Our approach begins by defining the chord length-parameter ratio (CPR), which we then predict for the current interpolation point using Newton's divided difference interpolation polynomial and historical CPR data. Subsequently, we calculate the compensation length based on tangent and chord directions, and we correct the initial parameter using the second-order Runge–Kutta method. Importantly, our method involves only two calculations of the first derivative of the NURBS curve, making it computationally efficient compared to most approximation methods. To validate our proposed method, we conduct numerical simulations and compare its performance against several approximation methods and a recent feedback method. The results demonstrate that our approach excels in terms of both efficiency and accuracy, making it a promising solution for improving NURBS curve interpolation. [ABSTRACT FROM AUTHOR]

While brain function is supported and constrained by the underlying structure, the connectome-based link estimated by current approaches is either relatively moderate or accompanied by high model complexity, with the essential principles underlying structure-function coupling remaining elusive. Here, by proposing a mapping method based on network eigendecomposition, we present a concise and strong correspondence between structure and function. We show that the explanation of functional connectivity can be significantly improved by incorporating interactions between different structural eigenmodes. We also demonstrate the pronounced advantage of the present mapping in capturing individual-specific information with simple implementation. Applying our methodology to the human lifespan, we find that functional diversity decreases with age, with functional interactions increasingly dominated by the leading functional mode. We also find that structure-function liberality weakens with age, which is driven by the decreases in functional components that are less constrained by anatomy, while the magnitude of structure-aligned components is preserved. Overall, our work enhances the understanding of structure-function coupling from a collective, connectome-oriented perspective and promotes a more refined identification of functional portions relevant to human aging, holding great potential for mechanistic insights into individual differences associated with cognition, development, and neurological disorders. An eigenmode-based structural and functional connectivity mapping approach applied to diffusion and functional MRI data reveals decreased structure-function liberality with age across the human lifespan. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) are obligate plant symbionts of most land plants. In these organisms, thousands of nuclei that are either genetically similar (homokaryotic) or derived from two distinct parents (dikaryotic) co-exist in a large syncytium. Here, we investigated the impact of these two nuclear organizations on the mycorrhizal response of potatoes (Solanum tuberosum) by inoculating four potato cultivars with eight Rhizophagus irregularis strains individually (four homokaryotic and four dikaryotic). By evaluating plant and fungal fitness-related traits four months post inoculation, we found that AMF genetic organization significantly affects the mycorrhizal response of host plants. Specifically, homokaryotic strains lead to higher total, shoot, and tuber biomass and a higher number of tubers, compared to dikaryotic strains. However, fungal fitness-related traits showed no clear differences between homokaryotic and dikaryotic strains. Nucleotype content analysis of single spores confirmed that the nucleotype ratio of AMF heterokaryon spores can shift depending on host identity. Together, these findings continue to highlight significant ecological differences derived from the two distinct genetic organizations in AMF. [ABSTRACT FROM AUTHOR]

While the link between brain structure and function remains an ongoing challenge, the prevailing hypothesis is that the structure-function relationship may itself be gradually decoupling from unimodal to transmodal cortex. However, this hypothesis is constrained by the underlying models which may neglect requisite information. Here we relate structural and functional connectivity derived from diffusion and functional MRI through orthogonal eigenmodes governing frequency-specific diffusion patterns. We find that low-frequency eigenmodes contribute little to functional interactions in transmodal cortex, resulting in divergent structure-function relationships. Conversely, high-frequency eigenmodes predominantly support neuronal coactivation patterns in these areas, inducing structure-function convergence along a unimodal-transmodal hierarchy. High-frequency information, although weak and scattered, could enhance the structure-function tethering, especially in transmodal association cortices. Our findings suggest that the structure-function decoupling may not be an intrinsic property of brain organization, but can be narrowed through multiplexed and regionally specialized spatiotemporal propagation regimes. Brain structure and function have been observed to be increasingly untethered in transmodal cortex. Here, the authors show that structure-function coupling in these areas can be enhanced by diffusion patterns governed by high-frequency eigenmodes. [ABSTRACT FROM AUTHOR]

The relationship between strain and elastic energy is simplified by introducing a stress state parameter based on the generalised Hooke's law. It is assumed that the micro-element strengths satisfy the Weibull distribution and a new model for the non-linear evolution of energy is developed by introducing the concept of rock micro-element strengths. A sensitivity analysis of the model parameters is carried out on this basis. The results show that the model agrees well with the experimental data. The model is close to the deformation and damage laws of the rock and is able to reflect the relationship between the elastic energy and strain of the rock. By comparing with other model curves, the model of this paper is more suitable for the experimental curve. They show that the improved model could better describe the stress–strain relationship of rock. Finally, according to the analysis of the influence of the distribution parameter on the variation pattern of the elastic energy of the rock, the magnitude of the distribution parameter can directly reflect the peak energy of the rock. [ABSTRACT FROM AUTHOR]

Vitamin K2 plays an important role in electron transport, blood coagulation, and calcium homeostasis, and researchers have been trying to use microbes to produce it. Although our previous studies have shown that gradient radiation, breeding, and culture acclimation can improve vitamin K2 production in Elizabethkingia meningoseptica, the mechanism is still unclear. This study is the first which performs genome sequencing of E. meningoseptica sp. F2 as a basis for subsequent experiments and further comparative analyses with other strains. Comparative metabolic pathway analysis of E. meningoseptica sp. F2, E. coli, Bacillus subtilis, and other vitamin K2 product strains revealed that the mevalonate pathway of E. meningoseptica sp. F2 is different in bacteria at the system level. The expressions of menA, menD, menH, and menI in the menaquinone pathway and idi, hmgR, and ggpps in the mevalonate pathway were higher than those in the original strain. A total of 67 differentially expressed proteins involved in the oxidative phosphorylation metabolic pathway and citric acid cycle (TCA cycle) were identified. Our results reveal that combined gradient radiation breeding and culture acclimation can promote vitamin K2 accumulation probably by regulating the vitamin K2 pathway, oxidative phosphorylation metabolism pathway, and the citrate cycle (TCA cycle). [ABSTRACT FROM AUTHOR]

Different stress creep tests are conducted on the sandstone in this study to better describe the creep properties of rocks under different stress states. A model that describes the rock creep process is established. The various stages of creep can be described by combining the creep properties of the creep elements of the model. A new method for determining creep parameters is proposed by using the special point on the creep curve and the definition of creep deformation. The relationship between the creep parameters, stress, and time is analyzed. An improved creep model that considers the effects of stress state and time on the creep parameters is developed. This model is verified using experimental data and calculation results. Results shows that the improved creep model better describes the creep properties of rocks and provides a new method for determining future model parameters. The shear modulus of elastic model controls the instantaneous deformation. The shear modulus of viscoelastic model governs the limit of viscoelastic deformation. The shear viscoelastic coefficient of viscoelastic model increases with the increase in stress. The coefficient of viscoplastic model controls the viscoplastic creep rate. The coefficient of a nonlinear Newtonian dashpot mainly controls the accelerated creep deformation of rock. The calculation results of the proposed model agree well with the experimental data under the action of different stress levels. This model accurately reflects the creep characteristics of the primary and steady-state creep stages, and overcomes the shortcomings of the traditional Nishihara model in describing accelerated creep. [ABSTRACT FROM AUTHOR]

The biosynthesis of citric acid (CA) using Aspergillus niger as a carrier is influenced by mycelium morphology, which is determined by the expression level of morphology-related genes. As a key component of the fungal cell wall, chitin content has an important effect on morphogenesis, and to investigate the effects of this on fermentation performance, we used RNA interference to knockdown chitin synthase C (CHSC) and chitin synthase activator (CHS3) to obtain the single-gene mutant strains A. niger chs3 and chsC and the double mutant A. niger chs3C. We found that the CA fermentation performance of the two single mutants was significantly better than that of the double mutant. The mutant A. niger chs3-4 exhibited CA production potential compared to that of the parent strain in scale-up fermentation; we determined certain characteristics of CA high-yielding strain fermentation pellets. In addition, when chsC alone was silenced, there was very little change in chs3 mRNA levels, whereas those of chsC were significantly reduced when only chs3 was silenced. As this may be because of a synergistic effect between chsC and chs3, and we speculated that the latent activation target of CHS3 is CHSC, our results confirmed this hypothesis. This study is the first application of a separation and combination silence strategy of chitin synthase and chitin synthase activator in the morphology of A. niger CA fermentation. Furthermore, it provides new insights into the method for the morphological study of A. niger fermentation and the interaction of homologous genes. Key points: • The function of chitin synthase C (chsC) and chitin synthase activator (chs3) is tightly interrelated. • Mycelial morphology was optimized by knockdown of CHS3, resulting in the overproduction of citric acid. • The separation and combination silence strategies are promising tools for the interaction of homologous housekeeping genes. [ABSTRACT FROM AUTHOR]

While inequalities in science are common, most efforts to understand them treat scientists as isolated individuals, ignoring the network effects of collaboration. Here, we develop models that untangle the network effects of productivity defined as paper counts, and prominence referring to high-impact publications, of individual scientists from their collaboration networks. We find that gendered differences in the productivity and prominence of mid-career researchers can be largely explained by differences in their coauthorship networks. Hence, collaboration networks act as a form of social capital, and we find evidence of their transferability from senior to junior collaborators, with benefits that decay as researchers age. Collaboration network effects can also explain a large proportion of the productivity and prominence advantages held by researchers at prestigious institutions. These results highlight a substantial role of social networks in driving inequalities in science, and suggest that collaboration networks represent an important form of unequally distributed social capital that shapes who makes what scientific discoveries. While inequalities in science are common, most efforts to understand them treat scientists as isolated individuals, ignoring the network effects of collaboration. Here, the authors develop models that untangle the network effects of productivity and prominence of individual scientists from their collaboration networks. [ABSTRACT FROM AUTHOR]

In computer numerical control systems, linear segments generated by computer-aided manufacturing software are the most widely used toolpath format. Since the linear toolpath is discontinuous at the junction of two adjacent segments, the fluctuations on velocity, acceleration and jerk are inevitable. Local corner smoothing is widely used to address this problem. However, most existing methods use symmetrical splines to smooth the corners. When any one of the linear segments at the corner is short, the inserted spline will be micro to avoid overlap. This will increase the curvature extreme of the spline and reduce the feedrate on it. In this article, the corners are smoothed by a C 4 continuous asymmetric Pythagorean-hodograph (PH) spline. The curvature extreme of the proposed spline is investigated first, and K = 2.5 is determined as the threshold to constrain the asymmetry of the spline. Then, a two-step strategy is used to generate a blended toolpath composed of asymmetric PH splines and linear segments. In the first step, the PH splines at the corners are generated under the condition that the transition lengths do not exceed half of the length of the linear segments. In the second step, the splines at the corners are re-planned to reduce the curvature extremes, if the transition error does not reach the given threshold and there are extra linear trajectories on both sides of the spline trajectory. Finally, the bilinear interpolation method is applied to determine the critical points of the smoothed toolpath, and a jerk-continuous feedrate scheduling scheme is presented to interpolate the smoothed toolpath. Simulations show that, under the condition of not affecting the machining quality, the proposed method can improve the machining efficiency by 7.27 to 75.11 % compared to G 3 and G 4 methods. [ABSTRACT FROM AUTHOR]

Hashimoto's thyroiditis (HT) is the main cause of hypothyroidism. We develop a deep learning model called HTNet for diagnosis of HT by training on 106,513 thyroid ultrasound images from 17,934 patients and test its performance on 5051 patients from 2 datasets of static images and 1 dataset of video data. HTNet achieves an area under the receiver operating curve (AUC) of 0.905 (95% CI: 0.894 to 0.915), 0.888 (0.836–0.939) and 0.895 (0.862–0.927). HTNet exceeds radiologists' performance on accuracy (83.2% versus 79.8%; binomial test, p < 0.001) and sensitivity (82.6% versus 68.1%; p < 0.001). By integrating serologic markers with imaging data, the performance of HTNet was significantly and marginally improved on the video (AUC, 0.949 versus 0.888; DeLong's test, p = 0.004) and static-image (AUC, 0.914 versus 0.901; p = 0.08) testing sets, respectively. HTNet may be helpful as a tool for the management of HT. Hashimoto's thyroiditis (HT) is the main cause of hypothyroidism. Here the authors develop a deep learning model for diagnosis of HT on a large multi-site dataset including image and video data. [ABSTRACT FROM AUTHOR]

In high-speed CNC (compute numerical control) machining, the feedrate scheduling has played an important role to ensure machining quality and machining efficiency. In this paper, a novel feedrate scheduling method is proposed for generating smooth feedrate profile conveniently with the consideration of both chord error and kinematic error. First, a relationship between feedrate value and chord error is applied to determine the feedrate curve. Then, breaking points, which can split whole curve into several blocks, can be found out using proposed two step screening method. For every block, the feedrate profile based on Sigmoid function is generated. With the consideration of kinematic limitation and machining efficiency, a time-optimal feedrate adjustment algorithm is proposed to further adjust feedrate value at breaking points. After achieving feedrate profile for each block, all blocks' feedrate profile will be connected smoothly. The resulting feedrate profile is more concise compared with the polynomial profile and more efficient compared with the trigonometric profile. Finally, simulations with two free-form NURBS curves are conducted and comparison with the sine-curve method is carried out to verify the feasibility and applicability of the proposed method. In order to further validate the feasibility of proposed method, machining simulation experiments are also conducted using Unigraphics NX. [ABSTRACT FROM AUTHOR]

Cross-modal retrieval has become a topic of popularity, since multi-data is heterogeneous and the similarities between different forms of information are worthy of attention. Traditional single-modal methods reconstruct the original information and lack of considering the semantic similarity between different data. In this work, a cross-modal semantic autoencoder with embedding consensus (CSAEC) is proposed, mapping the original data to a low-dimensional shared space to retain semantic information. Considering the similarity between the modalities, an automatic encoder is utilized to associate the feature projection to the semantic code vector. In addition, regularization and sparse constraints are applied to low-dimensional matrices to balance reconstruction errors. The high dimensional data is transformed into semantic code vector. Different models are constrained by parameters to achieve denoising. The experiments on four multi-modal data sets show that the query results are improved and effective cross-modal retrieval is achieved. Further, CSAEC can also be applied to fields related to computer and network such as deep and subspace learning. The model breaks through the obstacles in traditional methods, using deep learning methods innovatively to convert multi-modal data into abstract expression, which can get better accuracy and achieve better results in recognition. [ABSTRACT FROM AUTHOR]

By comparing the survival rate and positive mutation rate of the primary mutagenic strain and progeny mutagenic strain under different radiation doses, the results showed that the tolerance of the mutagenic strain to radiation dose increased with the increase of the mutagenic generations. We adopted an improved gradient radiation breeding strategy to improve the breeding efficiency. The strains were treated with radiation in four stages. The first stage was low energy N+ ion implantation (ion energy 15 keV, dose 80 × 2.6 × 1013 cm−2). In the second stage, the energy and dose of N+ ion reached to 20 keV, 90 × 2.6 × 1013 cm−2. In the third stage, 60Co-γ radiation (dose of 1.56 kGy) was used. In the fourth stage, the radiation dose of 60Co-γ increased to 1.82 kGy. After each stage of radiation, the MK (Menaquinone) precursor 1, 4-dihydroxy-2-naphthalate (DHNA) was used as the stress factor to domesticate the mutant strains. By gradually increasing the concentration of DHNA in the culture medium, the substrate tolerance of Flavobacterium sp. was effectively improved. By measuring SOD (superoxide dismutase) activity and malondialdehyde, it showed that the cell damage caused by radiation mutagenesis to the offspring mutant was less than that of the primary mutant. Changes in membrane permeability and membrane potential of the mutant strains were reflected in changes in fluorescence intensity of luciferin diacetate and rhodamine 123, which could explain the enhanced substrate tolerance of strain F-2. After gradient radiation breeding and culture acclimation, the biomass of mutant Strain F-2 was 6.59 g/L, and the MK yield was 9.59 mg/L. [ABSTRACT FROM AUTHOR]

Since the beginning of the 21st century, the geoscience research has been entering a significant transitional period with the establishment of a new knowledge system as the core and with the drive of big data as the means. It is a revolutionary leap in the research of geoscience knowledge discovery from the traditional encyclopedic discipline knowledge system to the computer-understandable and operable knowledge graph. Based on adopting the graph pattern of general knowledge representation, the geoscience knowledge graph expands the unique spatiotemporal features to the Geoscience knowledge, and integrates geoscience knowledge elements, such as map, text, and number, to establish an all-domain geoscience knowledge representation model. A federated, crowd intelligence-based collaborative method of constructing the geoscience knowledge graph is developed here, which realizes the construction of high-quality professional knowledge graph in collaboration with global geo-scientists. We also develop a method for constructing a dynamic knowledge graph of multi-modal geoscience data based on in-depth text analysis, which extracts geoscience knowledge from massive geoscience literature to construct the latest and most complete dynamic geoscience knowledge graph. A comprehensive and systematic geoscience knowledge graph can not only deepen the existing geoscience big data analysis, but also advance the construction of the high-precision geological time scale driven by big data, the compilation of intelligent maps driven by rules and data, and the geoscience knowledge evolution and reasoning analysis, among others. It will further expand the new directions of geoscience research driven by both data and knowledge, break new ground where geoscience, information science, and data science converge, realize the original innovation of the geoscience research and achieve major theoretical breakthroughs in the spatiotemporal big data research. [ABSTRACT FROM AUTHOR]

Menaquinone-7 is involved in bone metabolism and can be used to prevent and treat osteoporosis. However, as a fat-soluble vitamin, menaquinone-7 has poor water solubility. As a surfactant, hydrophobins can change the affinity/hydrophobicity of the covered interface. In this study, menaquinone-7 was modified by hydrophobins, and the different addition ratios were explored. Moreover, Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and water contact angle (WCA) measurements indicated that hydrophobins effectively bind to menaquinone-7 and greatly increase the hydrophilicity of the surface of menaquinone-7. Studies on the metabolism of MC3T3-E1 cells showed that compared with native menaquinone-7, HGFI-modified menaquinone-7 can significantly promote osteoblast differentiation but inhibit osteoclast differentiation. Besides, the Mito-Tracker Green experiments show that HGFI-modified menaquinone-7 can significantly promote the activity of mitochondria in cells. These findings indicate that hydrophobins can be used as an effective biomaterial to modify menaquinone-7, promote the formation of osteoblasts, and better to bone balance. [ABSTRACT FROM AUTHOR]

8Effects of different treatments of menaquinone-7 on mitochondrial activity in MC3T3-E1 cells. 6Formation of extracellular mineralized nodules, detected by AR-S solution staining in MC3T3-E1 cells cultured with menaquinone-7, HGFI-modified menaquinone-7, and HGFI at different concentrations (0.1, 1.0, or 10 mg/L, respectively) for 7 days. a Cell image stained with AR-S solution. b The content of mineralized nodules detected by spectrophotometer. The cells were treated with menaquinone-7, HGFI-modified menaquinone-7, and HGFI at different concentration (0.1, 1.0, or 10 mg/L, respectively), a Fluorescence micrograph of cells after adding Mito-Tracker Green. b High-content screening analysis of mitochondrial fluorescence intensity in cells. [Extracted from the article]

In this paper, we present some weakly compatible and quasi-contraction results for self-mappings in fuzzy cone metric spaces and prove some coincidence point and common fixed point theorems in the said space. Moreover, we use two Urysohn type integral equations to get the existence theorem for common solution to support our results. The two Urysohn type integral equations are as follows: x (l) = ∫ 0 1 K 1 (l , v , x (v)) d v + g (l) , y (l) = ∫ 0 1 K 2 (l , v , y (v)) d v + g (l) , where l ∈ [ 0 , 1 ] and x , y , g ∈ E , where E is a real Banach space and K 1 , K 2 : [ 0 , 1 ] × [ 0 , 1 ] × R → R . [ABSTRACT FROM AUTHOR]

Prenyltransferase NovQ is a vital class involved in the biosynthesis of secondary metabolites such as clorobiocin and novobiocin. To investigate the relationship between structure and catalytic properties of NovQ, here, we have analyzed the substrate-binding site, namely PT barrel, and revealed that menadione hydroquinol formed intermolecular interactions with the residue Glu281 near the center of the active pocket. In this study, Glu281 was substituted with 9 diverse amino acids and catalytic properties of mutants were observed in vitro. Among them, E281Q showed 2.05-fold activities towards the aromatic substrate and prenyl donor, while others obtained catalytic efficiency between 8.4 and 88.6% of that of wild-type NovQ. Furthermore, the effects of catalytic conditions and substrate status on the activity of NovQ and its mutants were considered to obtain the optimized prenylated reaction. When the evolutionary NovQ variant E281Q was overexpressed in the host constructed to synthesize dimethylallyl diphosphate through the engineered mevalonate (MVA) pathway, we harvested up to 4.7 mg/L prenylated menadione at C-3 position by exogenously supplying the aromatic substrate. The construction of the microbial platform based on NovQ opens a new orientation to further biosynthesize various vitamin K2 with other ABBA prenyltransferases in E. coli. [ABSTRACT FROM AUTHOR]

T-spline has been recently developed to represent objects of arbitrary shapes in computer-aided design, computer graphics, and reverse engineering. In fact, fitting a T-spline over a point cloud is usually ineffective by using traditional iterative fit-and-refine paradigm. In traditional T-spline least-square fitting method, all control points are recomputed in each iteration, which costs large amount of calculations. In this paper, we propose a fast T-spline fitting method based on T-mesh segmentation. The segmentation technology is introduced to identify the inactive and active region of T-mesh. Computational costs can be largely reduced since only the control points in the active part need to be recalculated in the upcoming process, while those in inactive part are kept invariant once the fitting accuracy is achieved. Classical datasets are used to validate the proposed fast fitting method, and the experimental results yield that a total running time is reduced to 34 % of the traditional T-spline fitting method. We argue this method is particularly useful in the reconstruction of scanned scatter data of which the parameter distribution is not uniform. [ABSTRACT FROM AUTHOR]

The iso-scallop method has been long adopted to achieve a shorter overall machining length. The efficiency and machining performance of this method are largely dominated by the initial tool path. The preferred direction field supplies the local best feed directions. Usually, the offset paths generated by the iso-scallop method largely deviate from the preferred directions, even though the initial path is strictly along the preferred directions. The matching degree of the offset paths and preferred direction field should be taken into consideration when selecting an initial tool path. This paper presents a novel initial path selection method for the iso-scallop method to make whole iso-scallop tool paths and the preferred direction field consistent as much as possible. A surface is re-parameterized to keep the conformality between the surface and parametric domain, which leads to the more regular offset paths on the new parametric domain. By fitting the vector field, streamlines are generated for representing the preferred feed direction on the parametric domain. The offset similarity metric defined by the initial path and streamlines is constructed to measure the matching degree between offset paths and preferred feed directions. Then the feasible path with the best offset similarity for the streamlines will be selected as the initial tool path. In our case study, feed directions with the maximum strip width are chosen. The test results have shown that the tool paths generated by the proposed method achieved a better matching for the selected feed directions and a shorter overall length compared with some existing tool path generation methods. [ABSTRACT FROM AUTHOR]

Remanufacturing for aero-engine blades is an essential operation in current aerospace maintenance industry due to the significant cost savings involved. However, the individual geometric deformation in the damaged blades makes it very difficult to repair them automatically due to the lack of a model for the deformed blade. This paper proposes a new method to adaptively construct an accurate deformed blade model for remanufacturing by finding the deformation rule between the nominal blade model and the measured data collected from the deformed blade via scanning. Considering the precision of the scanned data, the flat regions of the scanned data and nominal model (suction face and pressure face) are segmented and extracted first. To achieve accurate matching results, the segmented scanned data are matched with the segmented nominal model by maintaining local rigidity under the optimal ICP (iterative closest point) framework. Then, the nonflat regions of the nominal model (leading edge and trailing edge as well as the damaged region) are stitched with the scanned data at selected fixed locations to construct the deformed blade model. A twisted compressor blade with some tip damage was selected in the case study to demonstrate the effectiveness of the proposed method. A reference deformed blade model acquired by a computational fluid dynamics software tool was utilized for comparison, and machining simulation was carried out to verify the remanufacturing result. [ABSTRACT FROM AUTHOR]

Increasing evidence shows that static magnetic fields (SMFs) can affect microbial growth metabolism, but the specific mechanism is still unclear. In this study, we have investigated the effect of moderate-strength SMFs on growth and vitamin K2 biosynthesis of Flavobacterium sp. m1-14. First, we designed a series of different moderate-strength magnetic field intensities (0, 50, 100, 150, 190 mT) and exposure times (0, 24, 48, 72, 120 h). With the optimization of static magnetic field intensity and exposure time, biomass and vitamin K2 production significantly increased compared to control. The maximum vitamin K2 concentration and biomass were achieved when exposed to 100 mT SMF for 48 h; compared with the control group, they increased by 71.3% and 86.8%, respectively. Interestingly, it was found that both the cell viability and morphology changed significantly after SMF treatment. Second, the adenosine triphosphate (ATP) and glucose-6-phosphate dehydrogenase (G6PDH) metabolism is more vigorous after exposed to 100 mT SMF. This change affects the cell energy metabolism and fermentation behavior, and may partially explain the changes in bacterial biomass and vitamin K2 production. The results show that moderate-strength SMFs may be a promising method to promote bacterial growth and secondary metabolite synthesis. [ABSTRACT FROM AUTHOR]

Bacillus subtilis natto is a GRAS bacterium. Nattokinase, with fibrinolytic and antithrombotic activities, is one of the major products of this organism. It is being gradually recognized that B. subtilis natto can also be used as a biosynthetic strain for vitamin K2, which has phenomenal benefits, such as effects in the prevention of cardiovascular diseases and osteoporosis along with antitumor effects. Knocking out of the aprN gene by homologous recombination could improve the redox potential and slightly increase the concentration of MK-7. By detecting the change in redox potential during the growth of B. subtilis natto, a good oxygen supply and state of the cell membrane were found to be beneficial to vitamin K2 synthesis. A two-step RSM was used to optimize the operation parameters and substrate concentration in the new residue-free fermentation culture. The optimal conditions for the residue-free medium and control were determined. The optimum concentrations of soybean flour, corn flour, and peptone were 78.9, 72.4, and 24.8 g/L, respectively. The optimum rotational speed and volume of the culture medium using a shaking flask were 117 rpm and 10%, respectively. The state and composition of the cell membranes were more stable when engineered bacteria were cultured in this residue-free fermentation medium. Finally, the concentration of MK-7 increased by 37% to 18.9 mg/L, and the fermentation time was shortened by 24 h. [ABSTRACT FROM AUTHOR]

This paper presents a novel method to generate three-axis CNC tool paths for machining freeform surfaces based on a preferred feed direction field. This research was initiated from a fluid dynamics behavior that the energy loss can be reduced when the streamlines of fluid and the small grooves on a surface are in the same directions. In this research, the fluid streamlines above the surface are defined by a collection of vectors. These vectors are regularized into a grid of vectors, and these regularized vectors are further projected onto the tangent planes of a grid of points on the surface to create the preferred feed direction field. Based on the parametric model of the surface, the vectors on the tangent planes of the surface are mapped into vectors in the parametric domain. A scalar function is constructed such that the isolines of this scalar function and the preferred feed direction vectors in the parametric domain are in the same directions. A group of isolines of the scalar function are identified and these isolines are mapped back onto the 3-D surface as the created tool paths considering the tolerance requirement. The developed method has been applied to generate the tool paths for machining surfaces of a compressor blade. [ABSTRACT FROM AUTHOR]

To obtain the soluble production of recombinant NovQ, it has been constructed into the pET28a system. Unfortunately, NovQ was mostly accumulated as inclusion bodies and existed in insoluble fractions of E. coli cell lysate. Four partners, namely His6, TrxA, GST and MBP, were investigated in fusion expression and co-expression to achieve soluble expression in E. coli strains BL21 (DE3) and Rosetta™ (DE3). MBP fusion expression revealed a forceful function in enhancing solubility compared with others, in which the soluble protein was approximately 70% of the total cellular proteins in E. coli. Improvement of rare tRNA abundance promoted the yield of total recombinant protein and the expression level of soluble protein. Besides, one-step purification method was applied and the purity of recombinant protein obtained using Ni–NTA resin was over 90%, where soluble recombinant MBP-NovQ was cleaved using TEV protease in vitro. This method could be an ideal method for soluble expression of ABBA prenyltransferases in E. coli. [ABSTRACT FROM AUTHOR]

Identity-based signature schemes enable any pair of users to communicate securely and to verify each other's identity without exchanging private or public keys, without keeping key directories, and without using the services of a third party. Such paradigms are very suitable for an emerging scenario of Multimedia Social Networks (MSNs), in which there are a large number of users, dynamic interaction and huge content sharing. A revocable identity-based signature(RIBS) scheme, proposed by Tsai et al., provides a revocation mechanism for controlling user's access dynamically. To capture a realistic and efficient scenario, In 2017, XiaoYing Jia et al. introduced an additional important component, called Cloud Revocation Server(CRS), where most of the computations needed during key-updates are of loaded to the CRS. With the surprising development of quantum computation technology in recent years, IBS schemes mentioned above, based on conventional number theory problem, would become vulnerable. Recently, lattice-based cryptography schemes were proved to be secure against quantum attacks. Although such efficient RIBS scheme based on Computational Diffle-Hellam Problem(CDH) assumption has been proposed, all the lattice-based RIBS do not achieve this realistic and efficient property. In this paper, we propose the first lattice-based RIBS with outsourced Cloud Service Provider(CSP). In our scheme, a user's private key is composed of both an partial private key and a time update key. The time update key is periodically updated by CSP and is transmitted over a public channel. Based on the hardness assumption of Short Integer Solution (SIS), we demonstrate that the proposed lattice-based RIBS scheme with outsourced revocation in cloud computing provides existential unforgeability against adaptive chosen-message attacks in the random oracle. As compared to the existing IBS schemes over lattices, our RIBS scheme has better performance in terms of energy consumption, signature size, signing key size, and the revocation mechanism with public channels. As the underlying lattice problem is intractable even for quantum computers, our scheme would work well in the quantum age. [ABSTRACT FROM AUTHOR]

Understanding the interaction of macro- and micronutrients is a prerequisite to targeting nutrient balance in crop production. A 3-year field study was conducted to determine mineral nutrient uptake of maize hybrids with N fertilizer application under different rotation systems. The experiment was arranged in a split-plot design with rotation [maize-alfalfa (MA), maize-soybean (MS), and continuous maize (MM)] by N rate (0, 50, 100 and 150 kg N ha−1) as the mainplot and hybrid as the subplot. Two additional treatments (200 and 250 kg N ha−1) were tested in MM. Maize plant total Mg, Zn, and Cu content were in the order: MA > MS > MM. Plant Fe uptake was the lowest in MA and not affected by N input. The increased Cu uptake with increasing N rates indicated the synergism of these two nutrients, whereas dilution effects of N application on stover Zn and Mg concentrations were recorded. Rotation systems and N rates interactively affected nutrient harvest index and internal efficiency of Zn, Mg, Fe, and Cu. Relationships of plant N with Cu and Mg concentrations, and N with Zn, Mg, and Cu content at the V6 stage were established, but they were not necessarily preserved at maturity due to the progressive synergistic and dilution effects. The findings of nutrient uptake of Cu, Zn, Mg and Fe and their relationships with N nutrition in maize with stacked transgenic traits are important for developing best management practices to achieve concurrent improvements in nutrient use efficiency and crop productivity. [ABSTRACT FROM AUTHOR]

Proliferation of anchorage-dependent cells occurs after adhesion to a suitable surface. Thus, quantitative information about the force of cells adhesion to microcarriers at early culture phases is vital for scaling up such system. In this work, a newly designed shear-generating device was proposed, based on a previously proposed contraction flow device designed for suspended cells. A design equation for the new device was also proposed to correlate the generated energy dissipation rate (EDR) with the cross-sectional area and flow rate. Microscopic-particle image velocimetry was measured to validate the simulation results, and good agreement was achieved. The newly designed device was then used to measure the adhesion force of MDCK and PK cells, and the results showed that the critical EDR was 3000 W/m3 for MDCK and 5000 W/m3 for PK cells. This quantitative information is of great value for better understanding shearing effects during the scaling up of anchorage-dependent cell cultures. [ABSTRACT FROM AUTHOR]

The mycelial morphology of Aspergillus niger, a major filamentous fungus used for citric acid production, is important for citric acid synthesis during submerged fermentation. To investigate the involvement of the chitin synthase gene, chsC, in morphogenesis and citric acid production in A. niger, an RNAi system was constructed to silence chsC and the morphological mutants were screened after transformation. The compactness of the mycelial pellets was obviously reduced in the morphological mutants, with lower proportion of dispersed mycelia. These morphological changes have caused a decrease in viscosity and subsequent improvement in oxygen and mass transfer efficiency, which may be conducive for citric acid accumulation. All the transformants exhibited improvements in citric acid production; in particular, chsC-3 showed 42.6% higher production than the original strain in the shake flask. Moreover, the high-yield strain chsC-3 exhibited excellent citric acid production potential in the scale-up process.The citric acid yield and the conversion rate of glucose of chsC-3 were both improved by 3.6%, when compared with that of the original strain in the stirred tank bioreactor. [ABSTRACT FROM AUTHOR]

Menaquinone homologs (MK-n), that is, MK-4, MK-5, and MK-6, can be produced by the fermentation of Flavobacterium. In this study, we proposed a simple and efficient method for the extraction of menaquinones from wet cells without the process of drying the biomass. Meanwhile, a rapid and effective solution for the separation of menaquinone homologs was developed using a single organic solvent, which was conducive to the recovery of the solvent. The results showed that the highest yield was obtained with pretreatment using absolute ethanol at a ratio of 6:1 (v/m) for 30 min and then two extractions of 30 min each using methanol at a ratio of 6:1 (v/m). The recovery efficiency of the menaquinones reached to 102.8% compared to the positive control. The menaquinone homologs were effectively separated using methanol as eluent at a flow rate of 0.52 mL/min by a glass reverse-phase C18 silica gel column with a height-to-diameter ratio of 5.5:1. The recovery of menaquinones achieved was 99.6%. In conclusion, the methods for extraction and separation of menaquinone homologs from wet Flavobacterium cells were simple and efficient, which makes them suitable not only on a laboratory scale but also for application on a large scale. [ABSTRACT FROM AUTHOR]

In this paper, we propose a novel low dimensional chaotic map, namely, compounded piecewise linear map (CPLM) in order to balance between security and computational complexity. Then we prove the chaotic properties of CPLM theoretically and numerically. Based on the CPLM, an efficient chaotic image encryption algorithm is presented, in which the self-adaptive model and feedback mechanism are initially mingled to enhance the security. Besides, initial values of iteration are generated in a new way to ensure the sensitivity for the changes of plain-image. Simulation results show that our scheme possesses the high key sensitivity, large key space, fast encryption speed and resists the common attacks, especially differential attack. In addition, our algorithm satisfies the applicabilities of all-zero image and binary image which are seldom considered in the existing algorithms. The proposed algorithm justifies the superior security and good efficiency, which can be regarded as an excellent candidate for practical applications of image encryption. [ABSTRACT FROM AUTHOR]

With the increase of security requirements, numerous biometrics based authentication schemes that apply the smart card technology are proposed for multimedia medicine information systems in the last several years. Recently, Lu et al. presented a biometrics based authentication and key agreement scheme using extended Chebyshev chaotic maps. Unfortunately, we find that their scheme is still insecure with respect to issues such as flaws in the both login phase and password change phase. And we show that their scheme is vulnerable to the Denial-of-Service attack, user impersonation attack and server masquerade attack, which also fails to achieve the user anonymity. In order to remedy these weaknesses, we retain the useful properties of Lu et al.'s scheme to propose a robust biometrics based authentication and key agreement scheme for multimedia medicine information systems. The informal and formal security analysis of our scheme are given respectively, which demonstrate that our scheme satisfies the desirable security requirements. Furthermore, the proposed scheme provides some significant features which are not considered in most of the related schemes, such as, biometric information protection and user re-registration or revocation. Thus, our scheme resists the known attacks and is efficient for practical applications in the multimedia medicine information systems. [ABSTRACT FROM AUTHOR]

In recent years, chaos-based image encryption algorithms have attracted much attention. Particularly, with larger data capacity and higher correlation among pixels, encryption of colour images demands better statistic and diffusion properties of image algorithms than that of grey images. In this paper, a chaos-based algorithm aiming at colour image encryption is proposed. Two 3D chaotic systems are used as key generators for three colours of colour images' pixels. 4-Pixel Feistel structure and functions based on multiple chaotic maps are used to improve the statistic and diffusion properties of cipher image. Dependent encryption progress is used to resist certain cryptanalysis methods, such as known-/chosen plaintext attack and chosen cipher attack. According to large number of simulation experiments, with good speed performance being taken into account, our algorithm has better properties and higher security level than certain other chaos-based colour image encryption algorithms. [ABSTRACT FROM AUTHOR]

Survivin has multiple functions in the progression of cancer. The aim of the present study was to investigate the influence of YM155, a specific survivin inhibitor, on the biological behavior of U87 glioblastoma cells. The proliferative activity and growth rate of U87 cells were determined by colony formation assay and mononuclear cell direct cytotoxicity assay (MTT assay). The reconstituted basement membrane penetrating capacity was determined by cell invasion assay. The cell movement and migratory capacity were detected by wound-healing repair assay. We found that inhibition of survivin by YM155 dramatically decreased the invasive and metastatic capacities of the cells, suppressed the proliferation, decelerated the rate of growth, and reduced the number of clones on soft agar. In conclusion, YM155 has the potential to be used in the clinical treatment of GBM. [ABSTRACT FROM AUTHOR]

Chitin synthases catalyze the formation of β-(1,4)-glycosidic bonds between N-acetylglucosamine residues to form the unbranched polysaccharide chitin, which is the major component of cell walls in most filamentous fungi. Several studies have shown that chitin synthases are structurally and functionally divergent and play crucial roles in the growth and morphogenesis of the genus Aspergillus although little research on this topic has been done in Penicillium chrysogenum. We used BLAST to find the genes encoding chitin synthases in P. chrysogenum related to chitin synthase genes in Aspergillus nidulans. Three homologous sequences coding for a class III chitin synthase CHS4 and two hypothetical proteins in P. chrysogenum were found. The gene which product showed the highest identity and encoded the class III chitin synthase CHS4 was studied in detail. To investigate the role of CHS4 in P. chrysogenum morphogenesis, we developed an RNA interference system to silence the class III chitin synthase gene chs4. After transformation, mutants exhibited a slow growth rate and shorter and more branched hyphae, which were distinct from those of the original strain. The results also showed that the conidiation efficiency of all transformants was reduced sharply and indicated that chs4 is essential in conidia development. The morphologies of all transformants and the original strain in penicillin production were investigated by light microscopy, which showed that changes in chs4 expression led to a completely different morphology during fermentation and eventually caused distinct penicillin yields, especially in the transformants PcRNAi1-17 and PcRNAi2-1 where penicillin production rose by 27 % and 41 %, respectively. [ABSTRACT FROM AUTHOR]

Chitin synthases, that catalyze the formation of chitin the major component of cell walls in most filamentous fungi, play crucial roles in the growth and morphogenesis. To investigate the roles of chitin synthase in Penicillium chrysogenum, we developed an RNAi system to silence the class III chitin synthase gene chs4. After transformation, mutants had a slow growth rate and shorter but highly branched hyphae. All transformants either were unable to form conidia or could form only a few. Changes in chs4 expression could lead to a completely different morphology and eventually cause distinct penicillin yields. In particular, the yield of one transformant was 41 % higher than that of the original strain. [ABSTRACT FROM AUTHOR]

Software trustworthiness has become one of the key restrictions for software service quality and the development of the software industry. However, trustworthiness attributes interlace structured and dynamical coupling relations, which causes great barriers for trustworthiness measurements of large-scale software. According to the dynamical evolutionary characteristics of software trustworthiness attributes, this paper proposes a new approach for optimizing the trustworthiness measurement in terms the kernel trustworthiness attributes, and improves a downsize-optimized statistical analysis method for software trustworthiness attributes based on their nonlinear relations. The improved method considerably simplifies the trustworthiness assessment of largescale software. Using theoretical analysis and numerical simulations, the feasibility of this method is verified using two typical examples that illustrate the realization of the trustworthiness measurement. [ABSTRACT FROM AUTHOR]

Tannase has been extensively applied to synthesize gallic acid esters. Bioimprinting technique can evidently enhance transesterification-catalyzing performance of tannase. In order to promote the practical utilization of the modified tannase, a few enzymatic characteristics of the enzyme and its kinetic and thermodynamics properties in synthesis of propyl gallate by transesterification in anhydrous medium have been studied. The investigations of pH and temperature found that the imprinted tannase holds an optimum activity at pH 5.0 and 40 °C. On the other hand, the bioimprinting technique has a profound enhancing effect on the adapted tannase in substrate affinity and thermostability. The kinetic and thermodynamic analyses showed that the modified tannase has a longer half-time of 1,710 h at 40 °C; the kinetic constants, the activation energy of reversible thermal inactivation, and the activation energy of irreversible thermal inactivation, respectively, are 0.054 mM, 17.35 kJ mol, and 85.54 kJ mol with tannic acid as a substrate at 40 °C; the free energy of Gibbs (Δ G) and enthalpy (Δ H) were found to be 97.1 and 82.9 kJ mol separately under the same conditions. [ABSTRACT FROM AUTHOR]

This paper is devoted to the finite-time disturbance attenuation problem of affine nonlinear systems. Based on the finite time Lyapunov stability theory, some finite-time H∞ performance criterions are derived. Then the state-feedback control law is designed and the structure of such a controller is investigated. Furthermore, it is shown that the H∞ controller can also make the closed-loop system satisfy finite-time H∞ performance for nonlinear homogeneous systems. An example is provided to demonstrate the effectiveness of the presented results. [ABSTRACT FROM AUTHOR]

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