bluuebunny/crossref_metadata_2025 huggingface dataset:
Anisotropic ion beam etching of fused silica to mitigate subsurface damage
Authors: Li Bo , Xiang Xia , Tian Chengxiang , Hou Chunyuan , Liao Wei , Deng Hongxiang , Jiang Xiaolong , Wang Haijun , Yuan Xiaodong , Jiang Xiaodong , Zu Xiaotao
Published: March 2020

The laser damage resistance of fused silica optics depends significantly on the surface quality. In this work, anisotropic etching with inert ion beams at various ion incident angles was performed to investigate the evolution of the fused silica surface. The results show that the surface is smoothed when the incident angle is below [Formula: see text]. However, the fused silica surface starts to become coarse owing to the formation of nanostructures on the surface when the incident angle exceeds [Formula: see text]. Further, ion beam etching at a large incident angle of [Formula: see text] removes subsurface defects and less induces nanostructures, resulting in reduction of the surface roughness. The concentrations of impurities and defects are both significantly reduced after ion beam etching. The surface quality, subsurface and surface defects, and surface impurities determine the variation in the laser damage threshold of fused silica with the ion incident angle. The results demonstrate successful application of ion beam etching to improve the laser damage resistant characteristics of fused silica optics. Ion beam etching is a very versatile tool that provides physical erosion to anisotropically mitigate surface damage of fused silica.
Structural and dynamics properties of double icosahedral Pd-Ag-Pt trimetallic clusters
Authors: Garip Ali Kemal , Taran Songül
Published: March 2020

Using Monte Carlo Basin-hopping algorithm within the Gupta potential, a systematic investigation has been performed for the best chemical ordering structures of 19-atom trimetallic [Formula: see text] nanoclusters with double icosahedral geometry. The structures with the lowest energy at Gupta level are then re-optimized by DFT relaxations and the DFT relaxations confirmed the lowest energy structures obtained at the Gupta level indicating the double icosahedron structure is favorable for 19-atom [Formula: see text] nanoclusters. It was observed that the caloric curves exhibit a smoother transition with structural isomerizations other than a sharp jump behavior.
The properties of Majorana bound states in topological superconductor nanowire
Authors: Liu Long , Li Yu-Xian
Published: March 2020

We investigate the differential conductance in topological superconductor nanowire. The appropriate proximity-induced s-wave superconductivity and an externally applied magnetic field can derive a critical value to illustrate the topological state of the nanowire. When the strength of magnetic field is below the critical value, the nanowire produces an interior gap, and the interior gap decreases as the magnetic field increases. When the magnetic field is bigger than the critical value, the interior gap disappears, and zero-bias conductance peak appears which indicates that nanowire transits into the topological phase. In particular, with increasing of the chemical potential, the nanowire is changed into the topological phase with more stronger magnetic field applied. As long as the spin-orbit coupling and magnetic field axes are perpendicular, the nanowire can always be transited into the topological phase at a sufficiently large magnetic field.
Unfolding Codimension-Two Subsumed Homoclinic Connections in Two-Dimensional Piecewise-Linear Maps
Authors: Simpson David J. W.
Published: March 2020

For piecewise-linear maps, the phenomenon that a branch of a one-dimensional unstable manifold of a periodic solution is completely contained in its stable manifold is codimension-two. Unlike codimension-one homoclinic corners, such “subsumed” homoclinic connections can be associated with stable periodic solutions. The purpose of this paper is to determine the dynamics near a generic subsumed homoclinic connection in two dimensions. Assuming the eigenvalues associated with the periodic solution satisfy [Formula: see text], in a two-parameter unfolding there exists an infinite sequence of roughly triangular regions within which the map has a stable single-round periodic solution. The result applies to both discontinuous and continuous maps, although these cases admit different characterizations for the border-collision bifurcations that correspond to boundaries of the regions. The result is illustrated with a discontinuous map of Mira and the two-dimensional border-collision normal form.
Hopf Bifurcation Analysis and Stability for a Ratio-Dependent Predator–Prey Diffusive System with Time Delay
Authors: Li Longyue , Mei Yingying , Cao Jianzhi
Published: March 2020

In this paper, we are focused on a new ratio-dependent predator–prey system that introduced the diffusive and time delay effect simultaneously. By analyzing the characteristic equations and the distribution of eigenvalues, we examine the stability and boundary of positive equilibrium states, and the existence of spatially homogeneous and spatially inhomogeneous bifurcating periodic solutions, respectively. Further, we prove that when [Formula: see text], the system has Hopf bifurcation at the positive equilibrium state. By using the center manifold reduction, we simplify the system so that we can convert an infinite-dimensional system into a low-dimensional finite-dimensional system. By using the normal form theory, we obtain explicit expressions for the direction, stability and period of Hopf bifurcation periodic solutions. Finally, we have illustrated the main results in this thesis by numerical examples, our work may provide some useful measures to save time or cost and to control the ecosystem.
Bifurcation Analysis of Phytoplankton and Zooplankton Interaction System with Two Delays
Authors: Jiang Zhichao , Dai Jiangtao , Zhang Tongqian
Published: March 2020

In this paper, the system of describing the interactions between poisonous phytoplankton and zooplankton is presented. It focuses on the effects of two delays on the dynamic behavior of the system. At first, the properties of solutions including positivity and boundedness are given. Next, the stability of equilibria and the existence of local Hopf bifurcation are established when delays change and cross some threshold values. Especially, the existence of global periodic solutions is discussed when the two delays are equal. Furthermore, the implicit algorithm is derived for deciding the properties of the branching periodic solutions by using center manifold theory. Some numerical simulations are performed for supporting the theoretical results. Finally, some conclusions are given.
Characterizing the Effects of Self- and Cross-Diffusion on Stationary Patterns of a Predator–Prey System
Authors: Zhang Jia-Fang , Shi Hong-Bo , Madzvamuse Anotida
Published: March 2020

In this paper, we study a nonlinear coupled predator–prey diffusion system which widely exists in ecosystem. It is found that the self-diffusion and cross-diffusion do not change the stability of the semi-equilibrium point of the corresponding predator–prey system. However, the two kinds of diffusion play an important role on the positive equilibrium, in virtue of which Turing instability of the corresponding diffusion system either continues to exist or disappears and becomes stable. On the stationary patterns of the nonlinear coupled system, we find some interesting results which differ from the phenomenon found in corresponding diffusion system. Strong cross-diffusion can make the corresponding system generate stationary patterns. Finally, numerical simulation is also done to verify the existence of the effects of self-diffusion and cross-diffusion.
Adaptive Synchronization of Fractional-Order Coupled Neurons Under Electromagnetic Radiation
Authors: Meng Fanqi , Zeng Xiaoqin , Wang Zuolei , Wang Xinjun
Published: March 2020

In this paper, we investigate the dynamical characteristics of four-variable fractional-order Hindmarsh–Rose neuronal model under electromagnetic radiation. The numerical results show that the improved model exhibits more complex dynamical behavior with more bifurcation parameters. Meanwhile, based on the fractional-order Lyapunov stability theory, we propose two adaptive control methods with a single controller to realize chaotic synchronization between two coupled neurons. Finally, numerical simulations show the feasibility and effectiveness of the presented method.
Memristor Synapse-Based Morris–Lecar Model: Bifurcation Analyses and FPGA-Based Validations for Periodic and Chaotic Bursting/Spiking Firings
Authors: Bao Han , Zhu Dong , Liu Wenbo , Xu Quan , Chen Mo , Bao Bocheng
Published: March 2020

Electromagnetic induction current sensed by the membrane potential in biological neurons can be characterized with a memristor synapse, which can be employed to demonstrate the real oscillating voltage patterns of Barnacle muscle fibers. This paper presents a 3D autonomous memristor synapse-based Morris–Lecar (abbreviated as m-ML) model, which is implemented through introducing a memristor synapse-based induction current to substitute the externally applied current in an existing 2D nonautonomous Morris–Lecar model. Making use of one- and two-parameter bifurcation plots and time-domain representations, diverse period-adding bifurcations as well as abundant periodic and chaotic burst firings are demonstrated. Through constructing the fold and Hopf bifurcation sets of fast spiking subsystem, bifurcation analyses of these chaotic and periodic burst firings are carried out. Moreover, the periodic and chaotic spiking firings and coexisting firing behaviors are illustrated by using one- and two-parameter bifurcation plots and local attraction basins. Finally, based on a field programmable gate array (FPGA) board, a compact digital electronic neuron is fabricated for the 3D m-ML model, from which periodic and chaotic bursting/spiking firings are experimentally measured to verify the results of the numerical simulations.
A Linear Spline Markov Approximation Method for Random Maps with Position Dependent Probabilities
Authors: Jin Congming , Ding Jiu
Published: March 2020

We present a rigorous convergence analysis of a linear spline Markov finite approximation method for computing stationary densities of random maps with position dependent probabilities, which consist of several chaotic maps. The whole analysis is based on a new Lasota–Yorke-type inequality for the Markov operator associated with the random map, which is better than the previous one in the literature and much simpler to obtain. We also present numerical results to support our theoretical analysis.
Coexisting Attractors, Energy Analysis and Boundary of Lü System
Authors: Jia Hongyan , Shi Wenxin , Qi Guoyuan
Published: March 2020

In this study, first, the phenomenon of multistability in the Lü system is found, which shows the coexistence of two different point attractors and one chaotic attractor. These coexisting attractors are dependent on initial conditions of the system while the parameters of the system are fixed. Then, the Lü system is transformed to a Kolmogorov-type system, which includes the conservative torque consisting of the inertial torque and the internal torque, the dissipative torque, and the external torque. Moreover, by analyzing the combination of different types of torques and investigating the cycling of energy based on the Casimir function and Hamiltonian function, the interaction between the external torque and other torques is found to be the main reason for the Lü system to generate chaos. Finally, by investigating the Casimir function, it is found that the boundary of the Lü system is only related to system parameters.
Chaos Suppression in a Gompertz-like Discrete System of Fractional Order
Authors: Danca Marius-F. , Fečkan Michal
Published: March 2020

In this paper, we introduce the fractional-order variant of a Gompertz-like discrete system. The chaotic behavior is suppressed with an impulsive control algorithm. The numerical integration and the Lyapunov exponent are obtained by means of the discrete fractional calculus. To verify numerically the obtained results, beside the Lyapunov exponent, the tools offered by the 0-1 test are used.
Continuous Sequences with Frequency Independence Generated by Discrete Spatiotemporal Systems
Authors: Tian Chuanjun
Published: March 2020

This paper is concerned with the frequency independent continuous sequences generated by the following discrete spatiotemporal system: [Formula: see text] where [Formula: see text] is a function and [Formula: see text] is a bounded subset of [Formula: see text]. Based on frequency measurement theory, a series of continuous sequences with frequency independence generated by a special case of this discrete spatiotemporal system is constructed.
Global solvability and eventual smoothness in a chemotaxis-fluid system with weak logistic-type degradation
Authors: Wang Yulan
Published: March 2020

We consider the coupled chemotaxis–Navier–Stokes system with logistic source term [Formula: see text] in a bounded, smooth domain [Formula: see text], where [Formula: see text] and where [Formula: see text], [Formula: see text] and [Formula: see text] are given parameters. Although the degradation here is weaker than the usual quadratic case, it is proved that for any sufficiently regular initial data, the initial-value problem for this system under no-flux boundary conditions for [Formula: see text] and [Formula: see text] and homogeneous Dirichlet boundary condition for [Formula: see text] possesses at least one globally defined weak solution. And this weak solution becomes smooth after some waiting time provided [Formula: see text].
AN IMMUNO-EPIDEMIOLOGICAL VECTOR–HOST MODEL WITH WITHIN-VECTOR VIRAL KINETICS
Authors: GULBUDAK HAYRIYE
Published: March 2020

A current challenge for disease modeling and public health is understanding pathogen dynamics across scales since their ecology and evolution ultimately operate on several coupled scales. This is particularly true for vector-borne diseases, where within-vector, within-host, and between vector–host populations all play crucial roles in diversity and distribution of the pathogen. Despite recent modeling efforts to determine the effect of within-host virus-immune response dynamics on between-host transmission, the role of within-vector viral dynamics on disease spread is overlooked. Here, we formulate an age-since-infection-structured epidemic model coupled to nonlinear ordinary differential equations describing within-host immune-virus dynamics and within-vector viral kinetics, with feedbacks across these scales. We first define the within-host viral-immune response and within-vector viral kinetics-dependent basic reproduction number [Formula: see text] Then we prove that whenever [Formula: see text] the disease-free equilibrium is locally asymptotically stable, and under certain biologically interpretable conditions, globally asymptotically stable. Otherwise, if [Formula: see text] it is unstable and the system has a unique positive endemic equilibrium. In the special case of constant vector to host inoculum size, we show the positive equilibrium is locally asymptotically stable and the disease is weakly uniformly persistent. Furthermore, numerical results suggest that within-vector-viral kinetics and dynamic inoculum size may play a substantial role in epidemics. Finally, we address how the model can be utilized to better predict the success of control strategies such as vaccination and drug treatment.
On Cucker–Smale dynamical systems with degenerate communication
Authors: Dietert Helge , Shvydkoy Roman
Published: March 2020

This paper introduces a new method for establishing alignment in systems of collective behavior with degenerate communication protocol. The communication protocol consists of a kernel defining interaction between pairs of agents. Degeneracy presumes that the kernel vanishes in a region, which creates a zone of indifference. A motivating example is the case of a local kernel. Lapses in communication create a lack of coercivity in the energy estimates. Our approach is the construction of a corrector functional that compensates for this lack of coercivity. We obtain a series of new results: unconditional alignment for systems on [Formula: see text] with degeneracy at close range and fat tail in the long range, and for systems on the circle with purely local kernels. The results are proved in the context of both the agent based model and its hydrodynamic counterpart (Euler alignment model). The method covers bounded and singular communication kernels.
DEEPSMP: A deep learning model for predicting the ectodomain shedding events of membrane proteins
Authors: Cao Zhongbo , Du Wei , Li Gaoyang , Cao Huansheng
Published: March 2020

Membrane proteins play essential roles in modern medicine. In recent studies, some membrane proteins involved in ectodomain shedding events have been reported as the potential drug targets and biomarkers of some serious diseases. However, there are few effective tools for identifying the shedding event of membrane proteins. So, it is necessary to design an effective tool for predicting shedding event of membrane proteins. In this study, we design an end-to-end prediction model using deep neural networks with long short-term memory (LSTM) units and attention mechanism, to predict the ectodomain shedding events of membrane proteins only by sequence information. Firstly, the evolutional profiles are encoded from original sequences of these proteins by Position-Specific Iterated BLAST (PSI-BLAST) on Uniref50 database. Then, the LSTM units which contain memory cells are used to hold information from past inputs to the network and the attention mechanism is applied to detect sorting signals in proteins regardless of their position in the sequence. Finally, a fully connected dense layer and a softmax layer are used to obtain the final prediction results. Additionally, we also try to reduce overfitting of the model by using dropout, L2 regularization, and bagging ensemble learning in the model training process. In order to ensure the fairness of performance comparison, firstly we use cross validation process on training dataset obtained from an existing paper. The average accuracy and area under a receiver operating characteristic curve (AUC) of five-fold cross-validation are 81.19% and 0.835 using our proposed model, compared to 75% and 0.78 by a previously published tool, respectively. To better validate the performance of the proposed model, we also evaluate the performance of the proposed model on independent test dataset. The accuracy, sensitivity, and specificity are 83.14%, 84.08%, and 81.63% using our proposed model, compared to 70.20%, 71.97%, and 67.35% by the existing model. The experimental results validate that the proposed model can be regarded as a general tool for predicting ectodomain shedding events of membrane proteins. The pipeline of the model and prediction results can be accessed at the following URL: http://www.csbg-jlu.info/DeepSMP/ .
Microviscosity and temperature sensors: The twists and turns of the photophysics of conjugated porphyrin dimers — a SPP/JPP Young Investigator Award paper
Authors: Vyšniauskas Aurimas , Kuimova Marina K.
Published: March 2020

Conjugated porphyrin dimers have captured the imagination of scientists due to a set of unique spectroscopic features such as remarkable nonlinear-optical properties, high yields of singlet oxygen sensitization and the absorption and emission in the far-red region of the visible spectrum. Here we review a range of newly emerged applications of porphyrin dimers as sensors of their microenvironment such as viscosity and temperature. We discuss the sensing mechanism based on the known conformational flexibility of the dimer structure and describe possible applications of these unique sensors, from detecting viscosity increase during photoinduced cell death to structural responses of polymers and artificial lipid membranes, to temperature changes, and to mechanical deformation.
Reactive Additive Manufacturing Simulation of Thermoset Nano Graphene Inclusion
Authors: Abdi Frank , Baid Harsh , Moazami Nima , Batten Jay , Huang Dade , Eftekharian Amirhossein , Hajiha Reza , Nikbin Kamran
Published: March 2020

During the 3D printing of graphene platelet inclusion in resin, residual stresses due to thermal loading can cause wrinkle/distortion of final part. This paper presents a multi-scale modeling approach to reduce the residual thermal stress at the interphase between inclusion and resin. Material characterization is performed utilizing an integrated multi-scale modeling approach: (a) nano modeling examines effect of defects such as void shape/size/distribution, platelet orientation, etc.); (b) micro-mechanics examines constituents (platelet/matrix/interphase, residual stress); (c) macro-mechanics examines the delamination and debonding. De-homogenized multi-scale modeling approach provides detailed stiffness/strength to Finite Element Model (FEM) for full structural/thermal progressive failure analysis to address wrinkling/distortion, damage and delamination evolution via cohesive traction separation.
Effects of AC/DC Electric Fields on Stretching DNA Molecules
Authors: Wang Ying , Gao Mingyan , Qu Yingmin , Hu Jun , Xie Ying , Liu Ziyu , Song Zhengxun , Xu Hongmei , Weng Zhankun , Wang Zuobin
Published: March 2020

The effects of AC/DC electric fields on stretching DNA molecules were discussed in this work. In the experiments of stretching DNA molecules with AC/DC electric fields, the voltage range was changed from 0[Formula: see text]V to 10[Formula: see text]V, and the frequency of AC electric field was kept at 50[Formula: see text]kHz. An atomic force microscope (AFM) was used to obtain DNA distributions under different electric fields. DNA molecules were curved and randomly distributed in solution if there was not any force applied to them. When an AC electric field was applied to the DNA sample, the curvature of DNA molecules was decreased gradually, and the stretching result was more obvious with the increase of voltage from 0.1[Formula: see text]V to 5[Formula: see text]V. The DNA molecules were broken when the voltage was increased to 6[Formula: see text]V. However, under the DC electric field, the stretching result of DNA molecules reached to their optimum state when the voltage was 2[Formula: see text]V, and they kept their steady state even though larger electric field intensities applied to the electrodes. The results can be used for the study of DNA–DNA, protein–DNA and quantum dot–DNA interactions and for the exploration of DNA biophysical properties.
Electronic Structure and Ferromagnetic Properties of Doped Calcium Sulfide Ca1−xTMxS (TM = V, Cr and Co)
Authors: Aiche Amina , Tadjer Abdelkader , Ahmed Mazouz Hadj Moulay , Doumi Bendouma , Khachai Houari
Published: March 2020

The electronic structure and magnetic properties of diluted Ca[Formula: see text]TMxS (TM[Formula: see text][Formula: see text][Formula: see text]V, Cr and Co) in the rocksalt structure at concentrations [Formula: see text], 0.125 and 0.25 were studied using the full-potential linearized augmented plane wave approximation of the density functional theory with the Wu-Cohen generalized gradient approximation (WC-GGA) and the Tran–Blaha-modified Becke–Johnson (TB-mBJ) potential. Features such as lattice constant, bulk modulus, spin-polarized band structures, total and local densities of states and magnetic properties have been computed. The electronic structure show that Ca[Formula: see text](V, Cr)xS at all the studied concentrations and the diluted Ca[Formula: see text]CoxS with [Formula: see text] compounds are half-metallic ferromagnets with spin polarization of 100%. The calculated total magnetic moments for Ca[Formula: see text]VxS and Ca[Formula: see text]CoxS show the same integer value of 3[Formula: see text][Formula: see text] per formula unit and Ca[Formula: see text]CrxS exhibit a total magnetic moment of 4[Formula: see text][Formula: see text], which confirm the half-metallic behavior of these compounds. We also calculated the values of the band edge spin splitting of the valence and conduction bands and the exchange constants. We have found that the ferromagnetic state is stable by the p-d exchange associated with the double-exchange mechanism. The diluted Ca[Formula: see text](V,Cr,Co)xS are found to be new promising candidates for spintronic applications.
Quantitative proteomic and phosphoproteomic profiling of ischemic myocardial stunning in swine
Authors: Wang Xue , Shen Xiaomeng , Weil Brian R. , Young Rebeccah F. , Canty John M. , Qu Jun
Published: March 2020

We first used ion current-based proteomics and phosphoproteomics to reliably identify novel alterations in protein expression and phosphorylation contributing to contractile dysfunction, extracellular matrix (ECM) damage, and programmed cell death in stunned myocardium and developed a comprehensive swine heart-specific proteome database, which provides a valuable resource for future research in porcine models of cardiovascular diseases.
Comprehensive assessment of mitochondrial respiratory function in freshly isolated nephron segments
Authors: McCrimmon Allison , Domondon Mark , Sultanova Regina F. , Ilatovskaya Daria V. , Stadler Krisztian
Published: March 2020

Changes in mitochondrial function are central to many forms of kidney disease, including acute injury, diabetic nephropathy, hypertension, and chronic kidney diseases. As such, there is an increasing need for reliable and fast methods for assessing mitochondrial respiratory function in renal cells. Despite being indispensable for many mechanistic studies, cultured cells or isolated mitochondria, however, often do not recapitulate in vivo or close to in vivo situations. Cultured and/or immortalized cells often change their bioenergetic profile and phenotype compared with in vivo or ex vivo situations, and isolated mitochondria are simply removed from their cellular milieu. This is especially important for extremely complex organs such as the kidney. Here, we report the development and validation of a new approach for the rapid assessment of mitochondrial oxygen consumption on freshly isolated glomeruli or proximal tubular fragments using Agilent SeaHorse XFe24 and XF96 Extracellular Flux Analyzers. We validated the technique in several healthy and diseased rodent models: the C57BL/6J mouse, the diabetic db/ db mouse and matching db/+ control mouse, and the Dahl salt-sensitive rat. We compared the data to respiration from isolated mitochondria. The method can be adapted and used for the rapid assessment of mitochondrial oxygen consumption from any rodent model of the investigator’s choice. The isolation methods presented here ensure viable and functional proximal tubular fragments and glomeruli, with a preserved cellular environment for studying mitochondrial function within the context of their surroundings and interactions.
Effects of uric acid dysregulation on the kidney
Authors: Dissanayake Lashodya V. , Spires Denisha R. , Palygin Oleg , Staruschenko Alexander
Published: March 2020

Recently, research has redirected its interests in uric acid (UA) from gout, an inflammatory disease in joints, to groups of closely interrelated pathologies associated with cardiovascular and kidney dysfunction. Many epidemiological, clinical, and experimental studies have shown that UA may play a role in the pathophysiology of the cardiorenal syndrome continuum; however, it is still unclear if it is a risk factor or a causal role. Hyperuricemia has been well studied in the past two decades, revealing mechanistic insights into UA homeostasis. Likewise, some epidemiological and experimental evidence suggests that hypouricemia can lead to cardiorenal pathologies. The goal of this review is to highlight why studying both hyperuricemia and hypouricemia is warranted as well as to summarize the relevance of UA to kidney function.
Uric acid and inflammation in kidney disease
Authors: Jung Su Woong , Kim Su-Mi , Kim Yang Gyun , Lee Sang-Ho , Moon Ju-Young
Published: March 2020

Asymptomatic hyperuricemia is frequently observed in patients with kidney disease. Although a substantial number of epidemiologic studies have suggested that an elevated uric acid level plays a causative role in the development and progression of kidney disease, whether hyperuricemia is simply a result of decreased renal excretion of uric acid or is a contributor to kidney disease remains a matter of debate. Over the last two decades, multiple experimental studies have expanded the knowledge of the biological effects of uric acid beyond its role in gout. In particular, uric acid induces immune system activation and alters the characteristics of resident kidney cells, such as tubular epithelial cells, endothelial cells, and vascular smooth muscle cells, toward a proinflammatory and profibrotic state. These findings have led to an increased awareness of uric acid as a potential and modifiable risk factor in kidney disease. Here, we discuss the effects of uric acid on the immune system and subsequently review the effects of uric acid on the kidneys mainly in the context of inflammation.
Transplanted senescent renal scattered tubular-like cells induce injury in the mouse kidney
Authors: Kim Seo Rin , Jiang Kai , Ferguson Christopher M. , Tang Hui , Chen Xiaojun , Zhu XiangYang , Hickson LaTonya J. , Tchkonia Tamara , Kirkland James L. , Lerman Lilach O.
Published: March 2020

Cellular senescence, a permanent arrest of cell proliferation, is characterized by a senescence-associated secretory phenotype (SASP), which reinforces senescence and exerts noxious effects on adjacent cells. Recent studies have suggested that transplanting small numbers of senescent cells suffices to provoke tissue inflammation. We hypothesized that senescent cells can directly augment renal injury. Primary scattered tubular-like cells (STCs) acquired from pig kidneys were irradiated by 10 Gy of cesium radiation, and 3 wk later cells were characterized for levels of senescence and SASP markers. Control or senescent STCs were then prelabeled and injected (5 × 105 cells) into the aorta of C57BL/6J mice. Four weeks later, renal oxygenation was studied in vivo using 16.4-T magnetic resonance imaging and function by plasma creatinine level. Renal markers of SASP, fibrosis, and microvascular density were evaluated ex vivo. Per flow cytometry, irradiation induced senescence in 80–99% of STCs, which showed increased gene expression of senescence and SASP markers, senescence-associated β-galactosidase staining, and cytokine levels (especially IL-6) secreted in conditioned medium. Four weeks after injection, cells were detected engrafted in the mouse kidneys with no evidence for rejection. Plasma creatinine and renal tissue hypoxia increased in senescent compared with control cells. Senescent kidneys were more fibrotic, with fewer CD31+ endothelial cells, and showed upregulation of IL-6 gene expression. Therefore, exogenously delivered senescent renal STCs directly injure healthy mouse kidneys. Additional studies are needed to determine the role of endogenous cellular senescence in the pathogenesis of kidney injury and evaluate the utility of senolytic therapy.
Insulin-Attenuated Inflammatory Response of Dendritic Cells in Diabetes by Regulating RAGE-PKCβ1-IRS1-NF-κB Signal Pathway: A Study on the Anti-Inflammatory Mechanism of Insulin in Diabetes
Authors: Zhao Liding , Li Ya , Lv Qingbo , Wang Min , Luan Yi , Song Jiale , Fu Guosheng , Ge Junbo , Zou Yunzeng , Zhang Wenbin
Published: March 2020

Background. Diabetes is associated with chronic inflammation, and dendritic cells (DCs) have proinflammatory effect in diabetes. The anti-inflammatory effect of insulin on diabetes is not entirely clear. The study aims to examine insulin-induced effects on the inflammatory response in DCs. Methods. Twenty-one C57BL/6 mice were divided into 3 groups. Streptozotocin was injected into the diabetic mice model. The bone marrow-derived DCs (BMDCs) were obtained from C57BL/6 mice. CD83, CD86, and type II major histocompatibility complex (MHC-II) of BMDCs were measured by flow cytometry. The fluctuations in the RNA levels of cytokines and chemokines were analyzed by quantitative RT-PCR. The concentrations of IFN-γ and TNF-α were calculated using ELISA kits, and the proteins were detected using western blot. Results. In CD11c+ DCs derived from the spleens with hyperglycemia, the expression of CD83 and CD86 in diabetic mice was significantly upregulated, coupled with a higher secretion level of cytokines and chemokines, and increased phosphorylation of NF-κB and IκB. Insulin therapy was found to have a reversal effect on the inflammatory response and immune maturation in DCs. In AGEs-BSA-stimulated BMDCs, insulin repressed the immune maturation and downregulated the expression of RAGE, phospho-PKCβ1, and serine phospho-IRS1 in an adose-dependent manner. Such effects can be abolished by PMA, but not IR-neutralizing antibody. AGEs-BSA-induced BMDCs immune maturation was inhibited by the neutralizing antibody of RAGE, the PKCβ1 inhibitor, or the IRS1 siRNA. Conclusions. Insulin has the capability of attenuating the inflammatory response of DCs in diabetes, partly through the downregulation of RAGE expression followed by the inhibition of PKCβ1 phosphorylation and IRS1 serine phosphorylation, resulting in the inactivation of IR binding-independent NF-κB. This might partly explain the antiatherogenic effect of insulin on diabetes.
Reinforcement Learning-Based Genetic Algorithm in Optimizing Multidimensional Data Discretization Scheme
Authors: Chen Qiong , Huang Mengxing , Xu Qiannan , Wang Hao , Wang Jinghui
Published: March 2020

Feature discretization can reduce the complexity of data and improve the efficiency of data mining and machine learning. However, in the process of multidimensional data discretization, limited by the complex correlation among features and the performance bottleneck of traditional discretization criteria, the schemes obtained by most algorithms are not optimal in specific application scenarios and can even fail to meet the accuracy requirements of the system. Although some swarm intelligence algorithms can achieve better results, it is difficult to formulate appropriate strategies without prior knowledge, which will make the search in multidimensional space inefficient, consume many computing resources, and easily fall into local optima. To solve these problems, this paper proposes a genetic algorithm based on reinforcement learning to optimize the discretization scheme of multidimensional data. We use rough sets to construct the individual fitness function, and we design the control function to dynamically adjust population diversity. In addition, we introduce a reinforcement learning mechanism to crossover and mutation to determine the crossover fragments and mutation points of the discretization scheme to be optimized. We conduct simulation experiments on Landsat 8 and Gaofen-2 images, and we compare our method to the traditional genetic algorithm and state-of-the-art discretization methods. Experimental results show that the proposed optimization method can further reduce the number of intervals and simplify the multidimensional dataset without decreasing the data consistency and classification accuracy of discretization.
Synthesis, Characterization and Antibacterial Activity of Schiff Base, 4-Chloro-2-{(E)-[(4-Fluorophenyl)imino]methyl}phenol Metal (II) Complexes
Authors: Ommenya F. K. , Nyawade E. A. , Andala D. M. , Kinyua J.
Published: March 2020

A new series of Mn (II), Co (II), Ni (II), Cu (II), and Zn (II) complexes of the Schiff base ligand, 4-chloro-2-{(E)-[(4-fluorophenyl)imino]methyl}phenol (C13H9ClFNO), was synthesized in a methanolic medium. The Schiff base was derived from the condensation reaction of 5-chlorosalicylaldehyde and 4-fluoroaniline at room temperature. Elemental analysis, FT-IR, UV-Vis, and NMR spectral data, molar conductance measurements, and melting points were used to characterize the Schiff base and the metal complexes. From the elemental analysis data, the metal complexes formed had the general formulae [M(L)2(H2O)2], where L = Schiff base ligand (C13H9ClFNO) and M = Mn, Co, Ni, Cu, and Zn. On the basis of FT-IR, electronic spectra, and NMR data, “O” and “N” donor atoms of the Schiff base ligand participated in coordination with the metal (II) ions, and thus, a six coordinated octahedral geometry for all these complexes was proposed. Molar conductance studies on the complexes indicated they were nonelectrolytic in nature. The Schiff base ligand and its metal (II) complexes were tested in vitro to evaluate their bactericidal activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis and Staphylococcus typhi) using the disc diffusion method. The antibacterial evaluation results revealed that the metal (II) complexes exhibited higher antibacterial activity than the free Schiff base ligand.
Mathematical Analysis of Rabies Infection
Authors: Bornaa C. S. , Seidu Baba , Daabo M. I.
Published: March 2020

A mathematical model is proposed to study the dynamics of the transmission of rabies, incorporating predation of dogs by humans. The model is shown to have a unique disease-free equilibrium which is globally asymptotically stable whenever ℛ0≤1. Local sensitivity analysis suggests that the disease can be controlled through reducing contact with infected dogs, increasing immunization of dogs, screening recruited dogs, culling of infected dogs, and use of dog meat as a delicacy.
Compressive Strength Gain Behavior and Prediction of Cement-Stabilized Macadam at Low Temperature Curing
Authors: Xu Yongli , Yang Guang , Zhao Hongyuan
Published: March 2020

For cement-based materials, the curing temperature determines the strength gain rate and the value of compressive strength. In this paper, the 5% cement-stabilized macadam mixture is used. Three indoor controlled temperature curing and one outdoor natural curing scenarios are designed and implemented to study the strength development scenario law of compressive strength, and they are standard temperature curing (20°C), constant low temperature curing (10°C), day interaction temperature curing (varying from 6°C to 16°C), and one outdoor natural temperature curing (in which the air temperature ranges from 4°C to 20°C). Finally, based on the maturity method, the maturity-strength estimation model is obtained by using and analyzing the data collected from the indoor tests. The model is proved with high accuracy based on the validated results obtained from the data of outdoor tests. This research provides technical support for the construction of cement-stabilized macadam in regions with low temperature, which is beneficial in the construction process and quality control.
Effect of Magnetic Field Coupled Deep Cryogenic Treatment on Wear Resistance of AISI 4140 Steel
Authors: Tang Liang , Yan Xianguo , Jiang Yijiang , Li Fan , Zhang Haidong
Published: March 2020

In this study, a new magnetic field coupled deep cryogenic treatment (MDCT) is developed and its effect on wear resistance of AISI 4140 steel is investigated. Compared with wear resistance of untreatment (UT), wear resistance of MDCT increases by 29%. Wear resistance is inversely proportional to the friction coefficient. The treatment promotes the phase transformation and dislocation movement to generate more martensite in multidirectional distribution and optimized carbide. It enhances material property and repairs surface defect. Moreover, the wear mechanism of MDCT is only abrasive wear in the form of microscopic cutting, while other process groups are oxidative wear and abrasive wear in the form of microscopic cutting and microscopic fracture.
Seismic Response Analysis and Control of Frame Structures with Soft First Storey under Near‐Fault Ground Motions
Authors: Liu Chunyang , Sun Peng , Shi Ruofan
Published: March 2020

This paper proposes two kinds of arrangements of buckling‐restrained brace dampers to strengthen soft‐first‐storey structures locally. Two types of near‐fault ground motion, with and without pulse, were selected for a study of the seismic response characteristics of soft‐first‐storey structures with and without buckling‐restrained brace dampers, and the effects of different bracing arrangements on improving the seismic performance of soft‐first‐storey structures were recognized. The results show that, compared with pulse‐free ground motion, near‐fault pulsed ground motion results in a more severe seismic response in soft‐first‐storey frame structures, leading to more serious and rapid destruction of the main structure. Buckling‐restrained brace dampers have an obvious energy dissipation effect, play a better role in protecting the main structure, and have good practicality. Compared with structures in which the buckling‐restrained brace dampers are arranged only on the bottommost layer, the bottom‐four‐layer‐support structure is more advantageous in terms of seismic performance.
Mycochemical Screening and Analysis, Antioxidant Activity, and Biochemical Composition of Fermentation Strain Snef1216 (Penicillium chrysogenum)
Authors: Sikandar Aatika , Zhang Mengyue , Wang Yuanyuan , Zhu Xiaofeng , Liu Xiaoyu , Fan Haiyan , Xuan Yuanhu , Chen Lijie , Duan Yuxi
Published: March 2020

Antioxidants are the radical scavengers that inhibit peroxidation and other free-radical processes, which in return safeguard different organisms from various diseases attributed to radical reactions. Synthetic antioxidants inhibit free radicals, but they also have harmful side effects. However, mycochemicals of natural fungal origin are safe and best substitutes for harmful synthetic chemical antioxidants. The prime objectives of the study include appropriate qualitative and quantitative mycochemical screening, antioxidant potential, and chemical composition of Snef1216 (Penicillium chrysogenum). The study has used aluminium chloride colourimetric method, Folin–Ciocalteu reagent assay, and DPPH (1,1-diphenyl-1-picrylhydrazyl) for analysis of total flavonoid content and phenol content and antioxidant activity, respectively. However, the presence of biologically active compounds was screened through gas chromatography-mass spectrometry (GC-MS). Quantitative analysis demonstrated the existence of flavonoids, glycosides, flavones, saponins, phenols, and catecholic tannins excluding alkaloids, terpenoids, steroids, and gallic tannins. The outcomes exposed total flavonoid content and phenolic content in P. chrysogenum were 85.31 ± 1.23 mg·QE/g and 135.77 ± 1.14 mg·GAE/g, respectively. Snef1216 (P. chrysogenum) displayed the highest free-radical scavenging activity with 63.86% inhibition of DPPH. The analysis confirms that Snef1216 (P. chrysogenum) is an alternative source of natural antioxidants. The obtained data have provided the foundation for its use in agricultural, environmental, and pharmaceutical industries.
Dynamic Characteristics of an Offshore Wind Turbine with Tripod Suction Buckets via Full-Scale Testing
Authors: Seo Yun-Ho , Ryu Moo Sung , Oh Ki-Yong
Published: March 2020

The dynamic characteristics of an offshore wind turbine with tripod suction buckets are investigated through finite element analysis and full-scale experiments. In finite element analysis, an integrated framework is suggested to create a simple yet accurate high fidelity model. The integrated framework accounts for not only the strain dependency of the soil but also for all dynamics in the seabed, including those of the soil, suction bucket skirt, and cap. Hence, the model accurately describes the coupling effect of translational and rotational motions of the seabed. The prediction results are compared to the experimental results obtained via full-scale testing in four stages during construction and in several operational conditions. The comparison shows that the stiffness of the suction bucket cap and strain dependency of the soil play a significant role in predicting natural frequency, suggesting that these two factors should be considered in finite element analysis for the accurate prediction of dynamic responses of an offshore wind conversion system. Moreover, dynamic analysis of the strain and acceleration measured during operational conditions shows that strain is more robust than acceleration with regard to the characterization of the overall dynamics of an offshore wind conversion system because the natural frequency of an offshore wind turbine is very low. It can be inferred that the measurement of strain is a more effective way to monitor the long-term evolution of dynamic characteristics. The suggested integrated framework and measurement campaign are useful not only to avoid conservatism that may incur additional costs during load calculation and design phases but also to establish an intelligent operation and maintenance strategy with a novel sensing technique.
Role of HSP60/HSP10 in Lung Cancer: Simple Biomarkers or Leading Actors?
Authors: Fucarino Alberto , Pitruzzella Alessandro
Published: March 2020

Cancers are one of the major challenges faced by modern medicine both because of their impact in terms of the amount of cases and of the ineffectiveness of therapies used today. A concrete support to the fight against them can be found in the analysis and understanding of the molecular mechanisms involving molecular chaperones. In particular, HSP60 and HSP10 seem to play an important role in carcinogenesis, supporting tumours in their proliferation, survival, and metastasis. Efforts must be directed toward finding ways to eliminate or block this “mistaken” chaperone. Therefore, the scientific community must develop therapeutic strategies that consider HSP60 and HSP10 as the possible target of an anti-tumoural treatment and not only as diagnostic biomarkers, since they contribute to the evolution of pre-cancerous respiratory pathologies in lung tumours. HSP60 acts at the mitochondrial, cytoplasmic, and extracellular levels in the development of cancer pathologies. The molecular mechanisms in which these chaperones are involved concern cell survival, the restoration of a condition of absence of replicative senescence, the promotion of pro-inflammatory environments, and an increase in the ability to form metastases. In this review, we will also present examples of interactions between HSP60 and HSP10 and different molecules and ways to exploit this knowledge in anticancer therapies for lung tumours. In order to improve not only chances for an earlier diagnosis but also treatments for patients suffering from this type of disease, chaperones must be considered as key agents in carcinogenesis and primary targets in therapeutics.
The Roles of Uterine Natural Killer (NK) Cells and KIR/HLA‐C Combination in the Development of Preeclampsia: A Systematic Review
Authors: Yang Xiuhua , Yang Yahui , Yuan Yiru , Liu Lin , Meng Tao
Published: March 2020

Preeclampsia (PE) is termed as a systemic disease that involves multiple organs; however, the exact etiology is still quite unclear. It is believed that the poor remodeling of uterine spiral arteries triggers PE, thereby causing failed placentation and producing inflammatory factors. The decline of blood flow results in lowering the nutrients and oxygen received by the fetus and augmenting the placental pressure in PE. Decidual immune cells, especially uterine natural killer (uNK) cells, are involved in the process of placentation. Decidual NK (dNK) cells significantly contribute to the vascular remodeling through the secretion of cytokines and angiogenic mediators in normal placental development. The abnormal activation of NK cells in both the peripheral blood and the decidua was counted among the causes leading to PE. The correlation existing between maternal killer cell immunoglobulin‐like receptor (KIR) and HLA‐C in trophoblast cells constitutes a robust evidence for the genetic etiology of PE. The combinations of the two kinds of gene systems, together with the KIR genotype in the mother and the HLA‐C group in her fetus, are likely to exactly decide the pregnancy outcome. The women, who have the inappropriate match of KIR/HLA‐C, are likely to be prone to the augmented risk of PE. However, the combinations of KIR/HLA‐C in PE undergo ethnic changes. The extensive prospective research works in Europe, Asia, and Africa are required for providing more findings in PE patients.