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SHP2, a pivotal component downstream of both receptor and non-receptor tyrosine kinases, has been underscored in the progression of various human cancers and neurodevelopmental disorders. Allosteric inhibitors have been proposed to regulate its autoinhibition. However, oncogenic mutations, such as E76K, convert SHP2 into its open state, wherein the catalytic cleft becomes fully exposed to its ligands. This study elucidates the dynamic properties of SHP2 structures across different states, with a focus on the effects of oncogenic mutation on two known binding sites of allosteric inhibitors. Through extensive modeling and simulations, we further identified an alternative allosteric binding pocket in solution structures. Additional analysis provides insights into the dynamics and stability of the potential site. In addition, multi-tier screening was deployed to identify potential binders targeting the potential site. Our efforts to identify a new allosteric site contribute to community-wide initiatives developing therapies using multiple allosteric inhibitors to target distinct pockets on SHP2, in the hope of potentially inhibiting or slowing tumor growth associated with SHP2.

SHP2, a pivotal component downstream of both receptor and non-receptor tyrosine kinases, has been underscored in the progression of various human cancers and neurodevelopmental disorders. Allosteric inhibitors have been proposed to regulate its autoinhibition. However, oncogenic mutations, such as E76K, convert SHP2 into its open state, wherein the catalytic cleft becomes fully exposed to its ligands. This study elucidates the dynamic properties of SHP2 structures across different states, with a focus on the effects of oncogenic mutation on two known binding sites of allosteric inhibitors. Through extensive modeling and simulations, we further identified an alternative allosteric binding pocket in solution structures. Additional analysis provides insights into the dynamics and stability of the potential site. In addition, multi-tier screening was deployed to identify potential binders targeting the potential site. Our efforts to identify a new allosteric site contribute to community-wide initiatives developing therapies using multiple allosteric inhibitors to target distinct pockets on SHP2, in the hope of potentially inhibiting or slowing tumor growth associated with SHP2.

The deformation of the track on bridge after the earthquake mainly includes bridge creep and seismic-induced deformation, which poses a serious threat to the running safety of trains. In order to study the influence of the comprehensive deformation on the train-bridge system, a three-dimensional model of train-bridge coupling analysis was established. New point estimation method was used to solve the stochastic problem of initial track irregularity, aiming to study the changes of system motion under different parameters including deformation degrees and train speed. Results show that system motion increases with the increase of track parameters, and the earthquake intensity has the greatest influence on the train the motion, which reaches the peak in 0.4 g. The train speed has the greatest influences on the bridge when the train speed reaches the peak value of 400 km/h, while the impact of bridge creep is the smallest. Conclusion was obtained that the results of random analysis are of more general significance, and that in the vehicle-bridge system considering comprehensive track deformation after earthquake, the damage effect of track deformation induced by earthquake intensity is mainly considered for train, and the impact of train speed shall be mainly considered in bridge design. [ABSTRACT FROM AUTHOR]

The space docking process must be simulated on the ground to guarantee the success of the space docking task. By synthesizing a physical simulation and a numerical simulation, a hybrid simulator can simulate the complicated contact process of space docking. A hybrid simulator consists of a robot (i.e., lower platform), upper platform, docking mechanisms, contact force and torque measurement system, and numerical simulation system. To ensure the simulation accuracy, the robot is expected to have a high structure stiffness, high structure natural frequency, and high bandwidth frequency response. However, these performances are always limited in implementation. In this paper, how the structural dynamics of the robot affect the hybrid simulation accuracy is studied. Due to the structural dynamics of the robot, the divergence and convergence of the hybrid simulation are both possible. The stability conditions are given. A distortion compensation method for the structure dynamics of the robot is proposed. The stability analysis after the compensation is given. The software emulations and experiments are used to verify the analysis and the distortion compensation method. Experiments on real docking mechanisms are given to show the applications. [ABSTRACT FROM AUTHOR]

PATZ1 is a ubiquitously expressed transcriptional repressor belonging to the ZBTB family that is functionally expressed in T lymphocytes. PATZ1 targets the CD8 gene in lymphocyte development and interacts with the p53 protein to control genes that are important in proliferation and in the DNA-damage response. PATZ1 exerts its activity through an N-terminal BTB domain that mediates dimerization and co-repressor interactions and a C-terminal zinc-finger motif-containing domain that mediates DNA binding. Here, the crystal structures of the murine and zebrafish PATZ1 BTB domains are reported at 2.3 and 1.8 Å resolution, respectively. The structures revealed that the PATZ1 BTB domain forms a stable homodimer with a lateral surface groove, as in other ZBTB structures. Analysis of the lateral groove revealed a large acidic patch in this region, which contrasts with the previously resolved basic co-repressor binding interface of BCL6. A large 30-amino-acid glycine- and alanine-rich central loop, which is unique to mammalian PATZ1 amongst all ZBTB proteins, could not be resolved, probably owing to its flexibility. Molecular-dynamics simulations suggest a contribution of this loop to modulation of the mammalian BTB dimerization interface.

Promotion of C-C bonds is one of the key fundamental questions in the field of CO2 electroreduction. Much progress has occurred in developing bulk-derived Cu-based electrodes for CO2-to-multicarbons (CO2-to-C2+), especially in the widely studied class of high-surface-area "oxide-derived" copper. However, fundamental understanding into the structural characteristics responsible for efficient C-C formation is restricted by the intrinsic activity of these catalysts often being comparable to polycrystalline copper foil. By closely probing a Cu nanoparticle (NP) ensemble catalyst active for CO2-to-C2+, we show that bias-induced rapid fusion or "electrochemical scrambling" of Cu NPs creates disordered structures intrinsically active for low overpotential C2+ formation, exhibiting around sevenfold enhancement in C2+ turnover over crystalline Cu. Integrating ex situ, passivated ex situ, and in situ analyses reveals that the scrambled state exhibits several structural signatures: a distinct transition to single-crystal Cu2O cubes upon air exposure, low crystallinity upon passivation, and high mobility under bias. These findings suggest that disordered copper structures facilitate C-C bond formation from CO2 and that electrochemical nanocrystal scrambling is an avenue toward creating such catalysts.

The relevance of the paper is the need for the removal of a large number of unexploded ordnance (UXO) on the Norwegian continental shelf during the installation of subsea pipelines. This paper tries to include the seabed in the simulation by using the coupled Eulerian-Lagrangian (CEL) method. The effects of water, soil, and trinitrotoluene (TNT) are approached by using the Eulerian formulation with a specified equation of status (EOS). The Us - Up's form of Mie-Gruneisen equation is used for the water and soil. The soil's strength is described by the linear Drucker-Prager yielding function. The Jones-Wilkins-Lee (JWL) equation of state is used for TNT. The steel pipe is approached by shell elements in a Lagrangian scheme. The strain rate effects on steel strength and failure strain have been considered through the Cowper and Symonds equation. The coupling between Eulerian and Lagrangian formulation is done by the general contact features provided by the Abaqus explicit solver. Three offset distances (2.5 m, 5 m, and 15 m) have been simulated. The simulation results are discussed in detail with respect to the water, soil, TNT, and pipeline deformations, respectively. Additionally, the axial force is also discussed. It is shown that the present numerical model is able to capture the main characteristics of such a complicated physical process. The influence of the seabed has been shown explicitly in all the offset distances analyzed. The empirical factor method may give over-conservative results. [ABSTRACT FROM AUTHOR]

Water dynamics in concentrated ionic solutions plays an important role in a number of material and energy conversion processes such as the charge transfer at the electrolyte-electrode interface in aqueous rechargeable ion batteries. One long-standing puzzle is that all electrolytes, regardless of their structure-making/breaking nature, make water rotate slower at high concentrations. To understand this effect, we present a theoretical simulation study of the reorientational motion of water molecules in different ionic solutions. Using an extended Ivanov model, water rotation is decomposed into contributions from large-amplitude angular jumps and a slower frame motion which was studied in a coarse-grained manner. Bearing a certain resemblance to water rotation near large biological molecules, the general deceleration is found to be largely due to the coupling of the slow, collective component of water rotation with the motion of large hydrated ion clusters ubiquitously existing in the concentrated ionic solutions. This finding is at variance with the intuitive expectation that the slowing down is caused by the change in fast, single-molecular water hydrogen bond switching adjacent to the ions.

Relevance. When calculating building structures for dynamic effects, the method of expanding the desired solution in a series according to the forms of natural oscillation is traditionally used. Depending on the complexity of the tasks to be solved, it is required to take into account a different number of forms - from the first few forms to tens or hundreds of forms. The results obtained are all the more accurate the more forms the calculation takes into account. As a rule, the contribution to the required parameters of the stress-strain state of the structure of unaccounted for higher oscillation forms is not evaluated in any way, although in some cases this must be done. In addition, the important question arises of performing the calculation with a reduced number of considered forms so as to obtain a sufficiently accurate result. The aim of the work. This work is devoted to the method of static accounting of higher forms of oscillation in the problems of the dynamics of building structures. The basic principles of the method are described, its use on a spatial rod system loaded with several harmonic forces with different frequencies is considered. Methods. The method of static accounting of higher forms of oscillations studied in this work requires the solution of one dynamic problem with a small number of forms and an auxiliary static problem. An important circumstance of the approach is that the static problem must be solved in two ways: the exact one and the decomposition method according to its own forms of oscillation, after which the static correction to the dynamic solution is calculated. Results . The approach proposed in the article can significantly reduce the computational cost of dynamic calculation in comparison with the classical approach with comparable accuracy of the results. This may be of value in solving problems of complex dynamic effects and for structures with inhomogeneous rigidity.

Wind energy is one of the world's current leading renewable energy resources. One of the major aspects of studying wind turbines is the structural dynamics for the turbine structure including blades and support structure. In the current work, the blades of the Advanced Wind Turbine (AWT-27) are investigated in a dynamic approach. Different wind fields have been generated for the study to provide different Design Load Conditions (DLCs). Three laminar wind velocities of 5 m/s, 12 m/s, and 17 m/s were simulated. Turbulent wind flow fields have also been generated at the three standard classes A, B and C of high, medium, and low turbulence intensities respectively. The generated wind fields are used as inputs to calculate the aerodynamic loads for each wind condition using the Blade Element Momentum (BEM) theory. Aerodynamic loads have been calculated, namely, the shear force on five different locations along the blade length. Results of the simulation are summarized such that the shear forces at the blade root, 30%, 50%, 70% of the blade length are known for each wind condition. The summary serves as a guide for further optimization of the blade structural design. [ABSTRACT FROM AUTHOR]

Smart factories Industry 4.0 on the basis of collaborative cyber-physical systems represents a future form of industrial networks. Supply chains in such networks have dynamic structures which evolve over time. In these settings, short-term supply chain scheduling in smart factories Industry 4.0 is challenged by temporal machine structures, different processing speed at parallel machines and dynamic job arrivals. In this study, for the first time, a dynamic model and algorithm for short-term supply chain scheduling in smart factories Industry 4.0 is presented. The peculiarity of the considered problem is the simultaneous consideration of both machine structure selection and job assignments. The scheduling approach is based on a dynamic non-stationary interpretation of the execution of the jobs and a temporal decomposition of the scheduling problem. The algorithmic realisation is based on a modified form of the continuous maximum principle blended with mathematical optimisation. A detailed theoretical analysis of the temporal decomposition and computational complexity is performed. The optimality conditions as well as the structural properties of the model and the algorithm are investigated. Advantages and limitations of the proposed approach are discussed. [ABSTRACT FROM AUTHOR]

We present here the synthesis of a novel fluorescent actinide polyrotaxane compound URCP1 through the utilization of an end‐cutting pseudorotaxane precursor with only the cucurbit[6]uril (CB[6]) macrocyclic components acting as linking struts. The non‐coordinating guest motif in the obtained polyrotaxane, with increased freedom and structural flexibility, can display intriguing temperature‐triggered conformational variations inside the cavity of CB[6], which was clearly evidenced by crystallographic snapshots at different temperatures. Notably, this observation of temperature‐triggered structural dynamics in URCP1 represents the first report of actinide polyrotaxane with such feature in solid‐state. Moreover, URCP1 has a high photoluminescence quantum yield (PLQY) of 49.8 %, comparable to other luminescent uranyl compounds, and can work as a fluorescent probe to selectively detect Fe3+ over other eight competing cations in aqueous solution, with the limit of detection being as low as 4.4×10−3 ppm. [ABSTRACT FROM AUTHOR]

Ultrasonic guided wave is an encouraging tool in structural health monitoring for civil, mechanical, ship, and aerospace devices. Most of heavy devices required a long-time running during the service, and the structure of these devices is under the vibration condition due to their inherent properties and working condition. This article mainly researches fatigue crack detection in vibration condition caused by operation using ultrasonic guided waves, aiming to study the application of ultrasonic guided waves in the field of structure dynamics. The detection method based on the difference index and the sequence curve of difference index between different states of crack is proposed to detect fatigue crack in vibration condition. The experiments are carried out on the fatigue testing platform and the vibration test-bed to investigate the relationship between opening states of fatigue crack and the difference index value of ultrasonic guided waves. In order to reduce the influence of loads applied by the fatigue testing platform on ultrasonic guided waves propagation, the initial experiment is first carried out to select the range of applied loads which have minimal influence on wave propagation. The results show that loads from 0 to 24 MPa have minimal effect on ultrasonic guided waves, and the difference index values of intact beam and cracked beam are in different orders of magnitude. Therefore, the method based on difference index value and sequence of difference index is credible to detect fatigue crack for structure in vibration condition. [ABSTRACT FROM AUTHOR]

This paper proposes a spectral element method-based analysis procedure to study further the low-frequency responses of the ground and building induced by high-speed railways. Based on an existing scale model building test in Portugal, the properties of the track–ground submodel are calibrated to determine the moving perturbation on the ground surface. In modeling the soil–structure coupled subsystem, multi-objective optimization is employed to estimate the equivalent structural properties to mitigate computational inefficiency when using continuum elements. The accuracy of the numerical prediction is compared with the experimental records at several monitoring points in terms of ground and floor slab vertical vibrations induced by two types of high-speed trains. In addition to the analysis of possible factors related to systematic discrepancies, special attention is paid to investigating the influence of (a) the presence of frame structure as well as (b) the vehicle properties on ground motion in this particular case. • Propose a 3D spectral element-based method for predicting HSR-induced vibration. • Validate the numerical approach with field experimental results, obtained in Portugal. • Introduce a fully coupled 3D soil–structure model with suitably estimated properties. • Assess the model building and train impacts on the vibration of ground and structure. [ABSTRACT FROM AUTHOR]

This study targets the behavior of shear buildings equipped with tuned liquid column dampers (TLCD) which attenuate dynamic load-induced vibrations. TLCDs are a passive damping system used in tall buildings. This kind of damper has proven to be very efficient, being an excellent alternative to mass dampers. A dynamic analysis of the structure-damper system was made using the software DynaPy, developed in the research process. The software solves the equations of motion through numeric integration using the central differences method. The simulations results obtained with DynaPy showed that the use of TLCD can reduce the dynamic response significantly for both harmonic excitations and random excitations.

In this paper, a dual problem formulation is developed in order to solve a multi-objective, multi-period and multi-commodity production–distribution (re)planning problem for a multi-stage centralised upstream network with structure dynamics considerations. The original idea of this study is to use the real logic of decision-making in companies and exclude demand constraint from the linear programming (LP) model. This allows transit from the classical transportation problem, formulated as an LP model in order to improve service level at the strategic inventory holding point. The formulation as an LP model makes it possible to formulate the dual problem. The performed structural analysis revealed some interesting managerial insights into building robust distribution plans and interconnecting decisions on distribution network design, planning, and sourcing. [ABSTRACT FROM AUTHOR]

Many of the existing methods and models of supply chain planning and control consider only one supply chain structure and assume it's more or less static in nature. In practice, supply chains have a multi-structural semantics and those multiple interrelated structures (organisational, functional, informational, financial, topological, technological, product, and energy structures) are dynamic and subject to many planned and disturbance-based changes. These changes are tackled by control activities which make planning an adaptive process. Although the supply chain optimal planning domain for static structures has been extensively investigated, the domain of planning and control of supply chains with structure dynamics merits more systematic and critical attention. In this study, an original form of supply chain representation as a dynamic system with changing multi-structural characteristics is developed. The structure dynamics control is a dynamic interpretation of the supply chain (re)synthesis process and aims at both advancing the supply chain (re)planning domain and enlarging the scope of the supply chain analysis domain that is currently rather limited. The developed approach is based on an optimal program control theory, active modelling objects, and structural–mathematical concept blended with mathematical programming. In this paper, we describe its basic features and exemplify possible applications and extensions regarding real planning and control problems faced by international supply chains in recent years. [ABSTRACT FROM PUBLISHER]

Promotion of C–C bonds is one of the key fundamental questions in the field of CO2 electroreduction. Much progress has occurred in developing bulk-derived Cu-based electrodes for CO2-to-multicarbons (CO2-to-C2+), especially in the widely studied class of high-surface-area “oxide-derived” copper. However, fundamental understanding into the structural characteristics responsible for efficient C–C formation is restricted by the intrinsic activity of these catalysts often being comparable to polycrystalline copper foil. By closely probing a Cu nanoparticle (NP) ensemble catalyst active for CO2-to-C2+, we show that bias-induced rapid fusion or “electrochemical scrambling” of Cu NPs creates disordered structures intrinsically active for low overpotential C2+ formation, exhibiting around sevenfold enhancement in C2+ turnover over crystalline Cu. Integrating ex situ, passivated ex situ, and in situ analyses reveals that the scrambled state exhibits several structural signatures: a distinct transition to single-crystal Cu2O cubes upon air exposure, low crystallinity upon passivation, and high mobility under bias. These findings suggest that disordered copper structures facilitate C–C bond formation from CO2 and that electrochemical nanocrystal scrambling is an avenue toward creating such catalysts. [ABSTRACT FROM AUTHOR]

This paper develops a novel method of bridge damage detection using statistical analysis of data from an acceleration-based bridge weigh-in-motion (BWIM) system. Bridge dynamic analysis using a vehicle-bridge interaction model is carried out to obtain bridge accelerations, and the BWIM concept is applied to infer the vehicle axle weights. A large volume of traffic data tends to remain consistent (e.g., most frequent gross vehicle weight (GVW) of 3-axle trucks); therefore, the statistical properties of inferred vehicle weights are used to develop a bridge damage detection technique. Global change of bridge stiffness due to a change in the elastic modulus of concrete is used as a proxy of bridge damage. This approach has the advantage of overcoming the variability in acceleration signals due to the wide variety of source excitations/vehicles--data from a large number of different vehicles can be easily combined in the form of inferred vehicle weight. One year of experimental data from a short-span reinforced concrete bridge in Slovenia is used to assess the effectiveness of the new approach. Although the acceleration-based BWIM system is inaccurate for finding vehicle axle-weights, it is found to be effective in detecting damage using statistical analysis. It is shown through simulation as well as by experimental analysis that a significant change in the statistical properties of the inferred BWIM data results from changes in the bridge condition. [ABSTRACT FROM AUTHOR]

The work presents a simulation-based Multi-Objective Optimization (MOO) framework for efficient production planning in Energy Supply Chains (ESCs). An Agent-based Model (ABM) that is more comprehensive than others adopted in the literature is developed to simulate the agent’s uncertain behaviors and the transaction processes stochastically occurring in dynamically changing ESC structures. These are important realistic characteristics that are rarely considered. The simulation is embedded into a Non-dominated Sorting Genetic Algorithm (NSGA-II)-based optimization scheme to identify the Pareto solutions for which the ESC total profit is maximized and the disequilibrium among its agent’s profits is minimized, while uncertainty is accounted for by Monte Carlo (MC) sampling. An oil and gas ESC model with five layers is considered to show the proposed framework and its capability of enabling efficient management of the ESC sustained production while considering the agent’s uncertain interactions and the dynamically changing structure.

Successful implementation of an active vibration control system is strictly correlated to the exact knowledge of the dynamic behavior of the system, of the excitation level and spectra and of the sensor and actuator’s specification. Only the correct management of these aspects may guarantee the correct choice of the control strategy and the relative performance. Within this paper, some preliminary activities aimed at the creation of a structurally simple, cheap and easily replaceable active control systems for metal panels are discussed. The final future aim is to control and to reduce noise, produced by vibrations of metal panels of the body of a car. The paper is focused on two points. The first one is the realization of an electronic circuit for Synchronized Shunted Switch Architecture (SSSA) with the right dimensioning of the components to control the proposed test article, represented by a rectangular aluminum plate. The second one is a preliminary experimental study on the test article, in controlled laboratory conditions, to compare performances of two possible control approach: SSSA and a feed-forward control approach. This comparison would contribute to the future choice of the most suitable control architecture for the specific attenuation of structure-born noise related to an automotive floor structure under deterministic (engine and road-tyre interaction) and stochastic (road-tyre interaction and aerodynamic) forcing actions.

Cryo-electron microscopy and X-ray crystallography have been the major tools of protein structure analysis for decades and will certainly continue to be essential in the future. Moreover, nuclear magnetic resonance or Förster resonance energy transfer can measure structural dynamics. Here, we propose to add optical second-harmonic generation (SHG), which is a nonlinear optical scattering process sensitive to molecular structures in illuminated materials, to the tool-kit of structural analysis methodologies. SHG can be expected to probe the structural changes of proteins in the physiological condition, and thus link protein structure and biological function. We demonstrate that a conformational change as well as its dynamics in protein macromolecular assemblies can be detected by means of SHG polarization measurement. To prove the capability of SHG polarization measurement with regard to protein structure analysis, we developed an SHG polarization microscope to analyze microtubules in solution. The difference in conformation between microtubules with different binding molecules was successfully observed as polarization dependence of SHG intensity. We also succeeded in capturing the temporal variation of structure in a photo-switchable protein crystal in both activation and inactivation processes. These results illustrate the potential of this method for protein structure analysis in physiological solutions at room temperature without any labeling.

Evaluating soil structure dynamics is a major challenge when analysing or modelling pedogenesis. Constructed Technosols are considered, by definition, to be good candidates for pedogenetic studies, insofar as their initial characteristics and implementation conditions are controlled. Thus, we developed an approach based on image analysis of soil microstructures in order to specify the structure dynamics of a constructed Technosol. We described and quantified porosity and aggregation descriptors on a microscale (1) from pictures of mesocosms performed during 14 months, using an innovative automatic high-resolution image-acquisition device (Soilinsight ®), and (2) from thin sections sampled in situ in a 1 ha field experiment at t0 and t2 (17 months). Plant root system architecture of Lupinus albus and the behavior of introduced earthworms (Lumbricus castaneus) were described using the Soilinsight® device. After 14 months, the pore surface was 10 times greater in the presence of plants and macrofauna than in the control samples. Although the biological activity promoted the genesis of aggregates, their dynamics were irregular. In fact, the proportion of aggregates varied depending on both root age and worm action. In situ, the soil was progressively compacted due to a significant decrease in the number of > 2000 µm pores. In the same way, three aggregate descriptors--number, area and shape--were selected as the most significant indicators of soil aggregation evolution during the early stages of pedogenesis. In conclusion, this approach, based on the quantification of microstructure parameters, did indeed allow the description and monitoring of 2D soil structure dynamics in both field and mesocosms conditions. Completed with 3D soil structure data, this micromorphological analysis could advantageously contribute to the impact of climatic and biological agents modelling on a structural evolution of Technosols during initial pedogenesis. [ABSTRACT FROM AUTHOR]

This paper develops a novel method of bridge damage detection using statistical analysis of data from an acceleration-based bridge weigh-in-motion (BWIM) system. Bridge dynamic analysis using a vehicle-bridge interaction model is carried out to obtain bridge accelerations, and the BWIM concept is applied to infer the vehicle axle weights. A large volume of traffic data tends to remain consistent (e.g., most frequent gross vehicle weight (GVW) of 3-axle trucks); therefore, the statistical properties of inferred vehicle weights are used to develop a bridge damage detection technique. Global change of bridge stiffness due to a change in the elastic modulus of concrete is used as a proxy of bridge damage. This approach has the advantage of overcoming the variability in acceleration signals due to the wide variety of source excitations/vehicles—data from a large number of different vehicles can be easily combined in the form of inferred vehicle weight. One year of experimental data from a short-span reinforced concrete bridge in Slovenia is used to assess the effectiveness of the new approach. Although the acceleration-based BWIM system is inaccurate for finding vehicle axle-weights, it is found to be effective in detecting damage using statistical analysis. It is shown through simulation as well as by experimental analysis that a significant change in the statistical properties of the inferred BWIM data results from changes in the bridge condition.

The paper suggests characteristics of the disease course in 193 adult acute diarrhea (AD) severe cases hospitalized in 2002-2004. Following the pathomorphological study records, the structures of AD cases hospitalized in 2002 - 2004 and in 2008-2010 has been compared. It is shown that adult AD severe cases are rather more than likely to have lethal outcome in case of comorbidity and hospital admission later than on the 3rd disease day. In the period of dysentery high-incidence level in structure of AD with lethal outcome, shigellosis (including that diagnosed morphologically) dominates, as compared to the period of dysentery low-incidence level when the burden of salmonellosis and AD of unknown etiology has been seen to grow.

Structure and dynamics of preferential solvation of K(I) ion in aqueous ammonia have been reinvestigated using ab initio quantum mechanical charge field (QMCF) molecular dynamics (MD) simulation. The average coordination number of the first solvation consists of 2 ammonia and 4 waters. The mean residence time is less than 2 ps confirming the rapid mobility of ligands. The distance evolution data shows the frequent of ligand exchanges. The second solvation shell shows a more labile structure. The NBO analysis of the first shell structure emphasizes that interaction of K(I)-H 2 O is stronger than K(I)-NH 3 . The Wiberg bond confirms a weak electrostatic of ion-ligand interaction. [ABSTRACT FROM AUTHOR]

We have investigated by time-resolved X-ray diffraction the manganese arsenide structure dynamics in MnAs/GaAs (001) epitaxial films, when the $\alpha \to \beta $ magnetostructural phase transition is triggered by an ultra-fast optical laser pulse. Understanding the photo-induced phase transition dynamics is relevant for applications of MnAs/GaAs (001) as a magnetically active template in laser-induced magnetization switching processes. The main goal of our experiment is to determine the timescales of the structural changes that are likely to play a role in laser-driven magnetization reversal. [ABSTRACT FROM AUTHOR]

Water dynamics in concentrated ionic solutions plays an important role in a number of material and energy conversion processes such as the charge transfer at the electrolyte-electrode interface in aqueous rechargeable ion batteries. One long-standing puzzle is that all electrolytes, regardless of their "structure-making/breaking" nature, make water rotate slower at high concentrations. To understand this effect, we present a theoretical simulation study of the reorientational motion of water molecules in different ionic solutions. Using an extended Ivanov model, water rotation is decomposed into contributions from large-amplitude angular jumps and a slower frame motion which was studied in a coarse-grained manner. Bearing a certain resemblance to water rotation near large biological molecules, the general deceleration is found to be largely due to the coupling of the slow, collective component of water rotation with the motion of large hydrated ion clusters ubiquitously existing in the concentrated ionic solutions. This finding is at variance with the intuitive expectation that the slowing down is caused by the change in fast, single-molecular water hydrogen bond switching adjacent to the ions. [ABSTRACT FROM AUTHOR]

Allosteric communication among domains in modular proteins consisting of flexibly linked domains with complimentary roles remains poorly understood. To understand how complementary domains communicate, we have studied human Pin1, a representative modular protein with two domains mutually tethered by a flexible linker: a WW domain for substrate recognition and a peptidyl-prolyl isomerase (PPIase) domain. Previous studies of Pin1 showed that physical contact between the domains causes dynamic allostery by reducing conformation dynamics in the catalytic domain, which compensates for the entropy costs of substrate binding to the catalytic site and thus increases catalytic activity. In this study, the S138A mutant PPIase domain, a mutation that mimics the structural impact of the interdomain contact, was demonstrated to display dynamic allostery by rigidification of the α2-α3 loop that harbors the key catalytic residue C113. The reduced dynamics of the α2-α3 loop stabilizes the C113-H59 hydrogen bond in the hydrogen-bonding network of the catalytic site. The stabilized hydrogen bond between C113 and H59 retards initiation of isomerization, which explains the reduced isomerization rate by ~20% caused by the S138A mutation. These results provide new insight into the interdomain allosteric communication of Pin1. [ABSTRACT FROM AUTHOR]

A dynamic model of an axially moving flexible beam subject to an inner pressure is present. The coupling principle between a flexible beam and inner pressure is analyzed first, and the potential energy of the inner pressure due to the beam bending is derived using the principle of virtual work. A 1D hollow beam element contain inner pressure is established. The finite element method and Lagrange's equation are used to derive the motion equations of the axially moving system. The dynamic responses are analyzed by Newmark- β time integration method. Based on the computed dynamic responses, the effects of inner pressure on beam dynamics are discussed. Some interesting phenomenon is observed. [ABSTRACT FROM AUTHOR]

This paper analyzes the performance of three different semi-active control algorithms used to calculate and manage the optimal damping forces generated by a pair of magnetorheological (MR) dampers installed in a two-story building. The semi-active algorithms used are the linear quadratic regulator (LQR) associated with the clipped optimal algorithm, an algorithm based on a prediction model and a dynamic inverse model using nonlinear autoregressive exogenous (NARX)-type artificial neural networks, and a decision-making algorithm based on fuzzy logic. Additionally, the performances of the proposed semi-active algorithms are compared to those of passively used control devices. The results show response value reductions exceeding 50% for all the semi-active control strategies, which considerably outperformed the passive control. The three control strategies are thus confirmed as interesting tools with potential applications as MR damper administrators. [ABSTRACT FROM AUTHOR]

This article presents a numerical simulation analysis of the ejection process of a rigid projectile under the coupling effect of a support structure, ejection gas and transverse flow in a launch tube. Based on the computational fluid dynamics method and nested dynamic mesh technique, the dynamic response model of the support structure is used to simulate the deformation loads of the support structure inside the tube and construct a multifield coupled model for underwater ejection. Through computational analysis, we focus on the evolution characteristics of the multiphase flow field during the ejection process, the development mechanism of the bubble at the tube outlet, and the trajectory and load response characteristics of the projectile. In addition, the effects of different launch conditions, such as transverse flow velocity and interphase heat and mass transfer effects, on the projectile ejection process are also analyzed. The results show that the established model can effectively characterise the ejection motion process of the projectile. The impact of the lateral flow causes drastic changes in the motion displacement and velocity of the projectile as well as the rotation angle and rotation angular velocity. Furthermore, the interphase heat and mass transfer effects have less influence on the ejection process of the projectile due to the temperature change of the high-temperature ejected gas caused by the intermittent interface between the bubble and the aqueous medium. • The loading situation of the projectile underwater ejection process is analyzed. • A multi-field coupled calculation model for underwater ejection is established. • The main reason for the change of the thermodynamic parameters of the ejection gas in the barrel is found to be the intermittent bubble interface. • The multiphase flow field variation and dynamic response characteristics of the projectile ejection process are clarified. • The influence of different ejection conditions on the underwater ejection process is studied. [ABSTRACT FROM AUTHOR]

A mixed-flow pump with an unshrouded impeller was computed by a one-way coupled fluid-structure simulation to evaluate a prediction accuracy of stress and analyze a flow pattern which caused the largest stress. The stress occurring around a blade root was predicted by a numerical simulation and compared with an experimental one. Five flow rates, Q/Qbep=0,40,70,100 and 120% were simulated and the predicted stresses at all flow rates agreed with the experimental ones within -11∼+6% accuracy. The largest stress occurred around a blade root on a pressure side of blade surface at all flow rates. The stress became largest at 70% flow rate. A flow pattern around the blade was analyzed to investigate how the largest stress occurred at 70% flow rate. It was found in this study that a flow separation occurred around a leading edge on a suction side of blade surface at 70% flow rate and the largest load was acting on an outside region of blade.

The sol-to-gel transition of an alginate rich in β- d -mannuronic acid residues and at a concentration of 0.1% w/v in 15 mM NaCl in the presence of calcium ions of 0 to 3.5 mM was studied with dynamic light scattering. The dynamics of the different systems added further insight into the alginate gel forming mechanisms. Below a Ca 2+ concentration of 0.7 mM, the build-up of small aggregates could be verified. Moreover, at a critical concentration, close to 0.9 mM Ca 2+ , a percolated, non-ergodic network started to form from some of these aggregates, with smaller aggregates still diffusing in the network. The system displayed strong non-ergodicy at high Ca 2+ concentrations with a non-ergodicity parameter that appeared to form discontinuously from near zero to a clearly non-zero value at the critical Ca 2+ concentration. [ABSTRACT FROM AUTHOR]