BACKGROUND & AIMS: :Stacking fault energies (SFE) were determined in additively manufactured (AM) stainless steel (SS 316 L) and equiatomic CrCoNi medium-entropy alloys. AM specimens were fabricated via directed energy deposition and tensile loaded at room temperature. In situ neutron diffraction was performed to obtain a number of faulting-embedded diffraction peaks simultaneously from a set of (hkl) grains during deformation. The peak profiles diffracted from imperfect crystal structures were analyzed to correlate stacking fault probabilities and mean-square lattice strains to the SFE. The result shows that averaged SFEs are 32.8 mJ/m2 for the AM SS 316 L and 15.1 mJ/m2 for the AM CrCoNi alloys. Meanwhile, during deformation, the SFE varies from 46 to 21 mJ/m2 (AM SS 316 L) and 24 to 11 mJ/m2 (AM CrCoNi) from initial to stabilized stages, respectively. The transient SFEs are attributed to the deformation activity changes from dislocation slip to twinning as straining. The twinning deformation substructure and atomic stacking faults were confirmed by electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The significant variance of the SFE suggests the critical twinning stress as 830 ± 25 MPa for the AM SS 316 L and 790 ± 40 MPa for AM CrCoNi, respectively.

背景与目标： : 在增材制造 (AM) 不锈钢 (SS 316  L) 和等原子CrCoNi中熵合金中确定了堆垛层错能 (SFE)。AM样品是通过定向能量沉积和在室温下拉伸加载制成的。进行了原位中子衍射，以在变形过程中一组 (hkl) 晶粒同时获得许多断层嵌入的衍射峰。分析了从不完全晶体结构衍射的峰轮廓，以将堆积断层概率和均方晶格应变与SFE相关联。结果表明，AM SS 316  L的平均sfe为32.8 mJ/m2，AM CrCoNi合金的平均sfe为15.1 mJ/m2。同时，在变形过程中，从初始阶段到稳定阶段，SFE分别从46至21 mJ/m2 (AM SS 316  L) 和24至11 mJ/m2 (AM CrCoNi) 变化。瞬态sfe归因于变形活动从位错滑移到应变孪晶的变化。通过电子背散射衍射 (EBSD) 和透射电子显微镜 (TEM) 证实了孪晶变形亚结构和原子堆垛层错。SFE的显着方差表明，AM SS 316  L的临界孪生应力分别为830   ±   25  MPa，AM CrCoNi的临界孪生应力分别为790   ±   40 mpa mpa。

BACKGROUND & AIMS: :A procedure for maximization of the density of entropy production in a single stationary two-step enzyme reaction is developed. Under the constraints of mass conservation, fixed equilibrium constant of a reaction and fixed products of forward and backward enzyme rate constants the existence of maximum in the density of entropy production is demonstrated. In the state with maximal density of entropy production the optimal enzyme rate constants, the stationary concentrations of the substrate and the product, the stationary product yield as well as the stationary reaction flux are calculated. The test, whether these calculated values of the reaction parameters are consistent with their corresponding measured values, is performed for the enzyme Glucose Isomerase. It is found that calculated and measured rate constants agree within an order of magnitude, whereas the calculated reaction flux and the product yield differ from their corresponding measured values for less than 20 % and 5 %, respectively. This indicates that the enzyme Glucose Isomerase, considered in a non-equilibrium stationary state, as found in experiments using the continuous stirred tank reactors, possibly operates close to the state with the maximum in the density of entropy production.

背景与目标： : 开发了一种在单个固定的两步酶反应中最大化熵产生密度的程序。在质量守恒的约束下，反应的固定平衡常数以及正向和反向酶速率常数的固定产物证明了熵产生密度的最大值。在熵产生密度最大的状态下，计算最佳酶速率常数，底物和产物的固定浓度，固定产物产率以及固定反应通量。对葡萄糖异构酶进行测试，测试这些反应参数的计算值是否与其相应的测量值一致。发现计算的和测量的速率常数在一个数量级内一致，而计算的反应通量和产物产率分别在小于20% 和5% 的时间内与它们相应的测量值不同。这表明，在使用连续搅拌釜反应器的实验中发现的以非平衡静止状态考虑的葡萄糖异构酶可能接近熵产生密度最大的状态。

BACKGROUND & AIMS: :We showed recently that exposure to whisker vibrations enhances coding efficiency in rat barrel cortex despite increasing correlations in variability (Adibi et al., 2013). Here, to understand how adaptation achieves this improvement in sensory representation, we decomposed the stimulus information carried in neuronal population activity into its fundamental components in the framework of information theory. In the context of sensory coding, these components are the entropy of the responses across the entire stimulus set (response entropy) and the entropy of the responses conditional on the stimulus (conditional response entropy). We found that adaptation decreased response entropy and conditional response entropy at both the level of single neurons and the pooled activity of neuronal populations. However, the net effect of adaptation was to increase the mutual information because the drop in the conditional entropy outweighed the drop in the response entropy. The information transmitted by a single spike also increased under adaptation. As population size increased, the information content of individual spikes declined but the relative improvement attributable to adaptation was maintained.

背景与目标： : 我们最近表明，尽管变异性之间的相关性增加，但暴露于晶须振动仍可提高大鼠桶皮层中的编码效率 (Adibi等，2013)。在这里，为了了解适应如何实现感官表现的这种改善，我们在信息论的框架内将神经元群体活动中携带的刺激信息分解为其基本组成部分。在感官编码的上下文中，这些成分是整个刺激集的响应的熵 (响应熵) 和以刺激为条件的响应的熵 (条件响应熵)。我们发现，适应在单个神经元水平和神经元群体的合并活动上都降低了响应熵和条件响应熵。但是，适应的净效果是增加互信息，因为条件熵的下降超过了响应熵的下降。在适应的情况下，单个峰值传输的信息也会增加。随着人口规模的增加，单个峰值的信息含量下降，但归因于适应的相对改善得以保持。

BACKGROUND & AIMS: :Epistasis is a key concept in the theory of adaptation. Indicators of epistasis are of interest for large systems where systematic fitness measurements may not be possible. Some recent approaches depend on information theory. We show that considering shared entropy for pairs of loci can be misleading. The reason is that shared entropy does not imply epistasis for the pair. This observation holds true also in the absence of higher order epistasis. We discuss a method for reducing the number of false positives. However, our main conclusion is that entropy-based approaches have serious limitations in this context.

背景与目标： : 上位性是适应理论中的一个关键概念。对于可能无法进行系统适应性测量的大型系统，上位性指标很重要。最近的一些方法依赖于信息理论。我们表明，考虑成对基因座的共享熵可能会产生误导。原因是共享熵并不意味着该对的上位性。在没有高阶上位性的情况下，此观察也成立。我们讨论了一种减少误报数量的方法。但是，我们的主要结论是，基于熵的方法在这种情况下具有严重的局限性。

BACKGROUND & AIMS: :Natural and social multivariate systems are commonly studied through sets of simultaneous and time-spaced measurements of the observables that drive their dynamics, i.e., through sets of time series. Typically, this is done via hypothesis testing: the statistical properties of the empirical time series are tested against those expected under a suitable null hypothesis. This is a very challenging task in complex interacting systems, where statistical stability is often poor due to lack of stationarity and ergodicity. Here, we describe an unsupervised, data-driven framework to perform hypothesis testing in such situations. This consists of a statistical mechanical approach-analogous to the configuration model for networked systems-for ensembles of time series designed to preserve, on average, some of the statistical properties observed on an empirical set of time series. We showcase its possible applications with a case study on financial portfolio selection.

背景与目标： : 自然和社会多变量系统通常是通过对驱动其动态的可观测物的同时和时间间隔的测量集进行研究的，即通过时间序列集进行研究。通常，这是通过假设检验完成的: 经验时间序列的统计属性与在适当的零假设下预期的统计属性进行检验。在复杂的交互系统中，这是一项非常具有挑战性的任务，由于缺乏平稳性和遍历性，统计稳定性通常很差。在这里，我们描述了一个无监督的数据驱动框架，用于在这种情况下执行假设检验。这包括一种统计机械方法-类似于网络系统的配置模型-用于时间序列的集合，旨在平均保留在经验时间序列集上观察到的某些统计属性。我们通过金融投资组合选择的案例研究来展示其可能的应用。

BACKGROUND & AIMS: :A global sensitivity analysis of a multiscale computational model of microvascular flow is presented. A total of 140 simulations have been completed and analyzed varying 6 input parameters and considering their effects on 7 output variables. Interestingly, the vascular network topology has been found as a determinant factor for both vasculature-related and interstitium-related quantities. Regarding the firsts, the vascular network topology has obtained a score of 5.5/6 and 6/6 for average and spatial distribution respectively (where 6 is the maximum and 1 is the minimum). On the other hand, considering interstitium-related quantities, the score is 4/6 and 5/6 for average and spatial distribution respectively. These results suggest that the network topology has a significant influence on the outcome of the computational analysis.

背景与目标： : 提出了微血管血流多尺度计算模型的全局灵敏度分析。总共完成了140个模拟，并分析了6个输入参数的变化，并考虑了它们对7个输出变量的影响。有趣的是，已发现血管网络拓扑结构是脉管系统相关量和间质相关量的决定因素。关于第一个，血管网络拓扑分别获得了平均和空间分布的5.5/6和6/6的分数 (其中6是最大值，1是最小值)。另一方面，考虑到间质相关的数量，得分分别为平均和空间分布的4/6和5/6。这些结果表明，网络拓扑结构对计算分析的结果有重大影响。

BACKGROUND & AIMS: :We investigate the evolution of the network entropy for consensus dynamics in classical and quantum networks. We show that in the classical case, the network differential entropy is monotonically non-increasing if the node initial values are continuous random variables. While for quantum consensus dynamics, the network's von Neumann entropy is in contrast non-decreasing. In light of this inconsistency, we compare several distributed algorithms with random or deterministic coefficients for classical or quantum networks, and show that quantum algorithms with deterministic coefficients are physically related to classical algorithms with random coefficients.

背景与目标： : 我们研究了经典网络和量子网络中共识动力学的网络熵的演变。我们证明，在经典情况下，如果节点初始值是连续随机变量，则网络微分熵是单调不增加的。而对于量子共识动力学，网络的冯·诺依曼熵却没有减少。鉴于这种不一致，我们比较了经典或量子网络的几种具有随机或确定性系数的分布式算法，并表明具有确定性系数的量子算法与具有随机系数的经典算法在物理上相关。

BACKGROUND & AIMS: :Multiscale modeling of muscular-skeletal systems-the materials and structures that help organisms support themselves and move-is a rapidly growing field of study that has contributed key elements to the understanding of these systems, especially from a multiscale perspective. The systems, including materials such as bone and muscle, have hierarchical structures ranging from the nano- to the macroscale, and it is difficult to understand their macroscopic behaviors, both physiological and pathological, without knowledge of their hierarchical structures and properties. In this review, we discuss the methods of multiscale modeling. Through a series of case studies about key materials in muscular-skeletal systems, we describe how different methods can bridge the gap between hierarchical structures and their roles in the systems' mechanical properties. In particular, we emphasize the importance of the quality of minerals in bone. Finally, we discuss biomimetic material designs facilitated by additive manufacturing technology.

背景与目标： : 肌肉骨骼系统的多尺度建模-帮助生物支撑自己和移动的材料和结构-是一个快速发展的研究领域，为理解这些系统做出了关键因素，特别是从多尺度的角度来看。包括骨骼和肌肉等材料在内的系统具有从纳米到宏观的层次结构，如果不了解其层次结构和特性，就很难理解其宏观行为，包括生理和病理行为。在这篇综述中，我们讨论了多尺度建模的方法。通过一系列有关肌肉骨骼系统中关键材料的案例研究，我们描述了不同的方法如何弥合层次结构之间的鸿沟及其在系统机械性能中的作用。我们特别强调骨骼中矿物质质量的重要性。最后，我们讨论了增材制造技术促进的仿生材料设计。

BACKGROUND & AIMS: :The restriction of a small molecule's motion on binding to a protein causes a loss of configurational entropy, and thus a penalty in binding affinity. Some energy models used in computer-aided ligand design neglect this entropic penalty, whereas others account for it based on an expected drop in the number of accessible rotamers upon binding. However, the validity of the physical assumptions underlying the various approaches is largely unexamined. The present study addresses this issue by using Mining Minima calculations to analyze the association of amprenavir with HIV protease. The computed loss in ligand configurational entropy is large, contributing approximately 25 kcal/mol (4.184 kJ/kcal) to DeltaG degrees. Most of this loss results from narrower energy wells in the bound state, rather than a drop in the number of accessible rotamers. Coupling among rotation/translation and internal degrees of freedom complicates the decomposition of the entropy change into additive terms. The results highlight the potential to gain affinity by designing conformationally restricted ligands and have implications for the formulation of energy models for ligand scoring.

背景与目标： : 小分子对与蛋白质结合的运动的限制会导致构型熵的损失，从而降低结合亲和力。计算机辅助配体设计中使用的某些能量模型忽略了这种熵损失，而其他模型则基于结合后可访问的旋转异构体数量的预期下降来解释它。但是，各种方法所依据的物理假设的有效性在很大程度上尚未得到检验。本研究通过使用Mining Minima计算来分析氨普瑞韦与HIV蛋白酶的关联来解决此问题。计算的配体构型熵的损失很大，对DeltaG度贡献约25 kcal/mol (4.184 kJ/kcal)。这种损失的大部分是由于约束状态下较窄的能量阱造成的，而不是可访问的旋转异构体数量的减少。旋转/平移和内部自由度之间的耦合使熵变化分解为加法项变得复杂。结果强调了通过设计构象受限的配体来获得亲和力的潜力，并对配体评分的能量模型的制定有影响。

BACKGROUND & AIMS: :Model hydroxyapatite (HA) scaffolds with porosities spanning multiple length scales were fabricated by robocasting, a solid freeform fabrication technique based on the robotic deposition of colloidal pastes. Scaffolds of various architectures including periodic, radial, and superlattice structures were constructed. Macropores (100-600 microm) were designed by controlling the arrangement and spacing between rods of HA. Micropores (1-30 microm) and submicron pores (less than 1 microm) were produced within the rods by including polymer microsphere porogens in the HA pastes and by controlling the sintering of the scaffolds. These model scaffolds may be used to systematically study the effects of scaffold porosity on bone ingrowth processes both in vitro and in vivo.

背景与目标： : 通过robocasting制造了具有多个长度尺度的孔隙率的羟基磷灰石 (HA) 模型支架，robocasting是一种基于胶体糊剂机器人沉积的固体自由形式制造技术。构建了各种体系结构的支架，包括周期性，径向和超晶格结构。通过控制HA杆之间的排列和间距来设计大孔 (100-600微米)。通过在HA糊中加入聚合物微球致孔剂并控制支架的烧结，在棒内产生微孔 (1-30微米) 和亚微米孔 (小于1微米)。这些模型支架可用于系统地研究支架孔隙率对体外和体内骨向内生长过程的影响。

BACKGROUND & AIMS: :Approximate entropy (ApEn) is a family of statistics introduced as a quantification of regularity in time series without any a priori knowledge about the system generating them. The aim of this preliminary study was to assess whether a time series analysis of arterial oxygen saturation (SaO2) signals from overnight pulse oximetry by means of ApEn could yield essential information on the diagnosis of obstructive sleep apnea (OSA) syndrome. We analyzed SaO2 signals from 187 subjects: 111 with a positive diagnosis of OSA and 76 with a negative diagnosis of OSA. We divided our data in a training set (44 patients with OSA Positive and 30 patients with OSA Negative) and a test set (67 patients with OSA Positive and 46 patients with OSA Negative). The training set was used for algorithm development and optimum threshold selection. Results showed that recurrence of apnea events in patients with OSA determined a significant increase in ApEn values. This method was assessed prospectively using the test dataset, where we obtained 82.09% sensitivity and 86.96% specificity. We conclude that ApEn analysis of SaO2 from pulse oximetric recording could be useful in the study of OSA.

背景与目标： : 近似熵 (ApEn) 是作为时间序列中规律性的量化而引入的统计数据族，而没有任何有关生成它们的系统的先验知识。这项初步研究的目的是评估通过ApEn对隔夜脉搏血氧饱和度 (SaO2) 信号进行的时间序列分析是否可以提供有关阻塞性睡眠呼吸暂停 (OSA) 综合征诊断的重要信息。我们分析了来自187名受试者的SaO2信号: 111名OSA诊断为阳性，76名OSA诊断为阴性。我们将数据分为训练集 (44例OSA阳性和30例OSA阴性) 和测试集 (67例OSA阳性和46例OSA阴性)。训练集用于算法开发和最佳阈值选择。结果显示，OSA患者呼吸暂停事件的复发决定了ApEn值的显着增加。使用测试数据集对该方法进行了前瞻性评估，其中我们获得了82.09% 敏感性和86.96% 特异性。我们得出的结论是，脉搏血氧记录对SaO2的ApEn分析可能对OSA的研究有用。

BACKGROUND & AIMS: :In the original publication of the article the affiliation of Kamen Ivanov was inaccurate. The correct affiliation of Kamen Ivanov is given below.

背景与目标： : 在文章的原始出版物中，Kamen Ivanov的隶属关系不准确。以下给出了假面伊万诺夫的正确隶属关系。

BACKGROUND & AIMS: :Event-related functional magnetic resonance imaging (ER-fMRI) refers to the blood oxygen level-dependent (BOLD) signal in response to a short stimulus followed by a long period of rest. These paradigms have become more popular in the last few years due to some advantages over standard block techniques. Most of the analysis of the time series generated in such exams is based on a model of specific hemodynamic response function. In this paper we propose a new method for the analysis of ER-fMRI based in a specific aspect of information theory: the entropy of a signal using the Shannon formulation, which makes no assumption about the shape of the response. The results show the ability to discriminate between activated and resting cerebral regions for motor and visual stimuli. Moreover, the results of simulated data show a more stable pattern of the method, if compared to typical algorithms, when the signal to noise ratio decreases.

背景与目标： : 事件相关的功能磁共振成像 (ER-fMRI) 是指对短暂刺激，随后长时间休息的血氧水平依赖性 (BOLD) 信号。由于与标准块技术相比具有一些优势，这些范例在最近几年变得越来越流行。在此类检查中生成的时间序列的大多数分析都是基于特定血液动力学响应函数的模型。在本文中，我们提出了一种基于信息论的特定方面的ER-fMRI分析的新方法: 使用Shannon公式的信号熵，该方法不对响应的形状进行假设。结果表明，能够区分运动和视觉刺激的激活和静止大脑区域。此外，当信噪比降低时，如果与典型算法相比，模拟数据的结果显示出该方法的更稳定模式。

BACKGROUND & AIMS: :Tremendous numbers of heart rate variability studies have aimed to elucidate age-associated alterations of autonomic function in the past decades. However, the studies, far from clarifying ageing mechanisms, fell into confusion by a lack of common scales. The purpose of this study is to show a possibility to establish a comparative scale of autonomic function through a method, tone-entropy (T-E) analysis on heart period variation, whose validity has been already examined on typical physiological cases (Oida et al. in J Appl Physiol 82:1794-1801, 1997; Oida et al. in J Gerontol 54A:M219-M224, 1999a; Oida et al. in Acta Physiol Scand 165:129-134, 1999b; Oida et al. in Acta Physiol Scand 165:421-422, 1999c; Amano et al. in Eur J Appl Physiol 94:602-610, 2005). In this study, 276 subjects from teens to seventies were examined at rest by T-E analysis together with conventional time and frequency domain analyses. The tone (negativity represents vagal predominance) became significantly high [-0.174 +/- 0.026 (teens) to -0.024 +/- 0.004 (seventies), P < 0.05 for one-way ANOVA], and the entropy (total autonomic activity), significantly low [4.40 +/- 0.12 (teens) to 2.90 +/- 0.09 bit (seventies), P < 0.05] with advancing age. The result, plotted in 2-D T-E space, showed that the ageing traced a curvi-linear relation from right-bottom to left-top, and was consistent with previously studied typical physiological cases. The conventional analyses showed almost the same autonomic reduction as T-E did, but failed in detecting delicate alteration of autonomic balance. The results, showing that autonomic activity reduced in both pathways impairing vagal predominance significantly with ageing, suggested a possibility to assess autonomic function in 2-D T-E space in a comparative way.

背景与目标： : 在过去的几十年中，大量的心率变异性研究旨在阐明与年龄相关的自主神经功能变化。然而，这些研究非但没有阐明衰老机制，反而因缺乏共同的量表而陷入混乱。这项研究的目的是通过一种方法，即心脏周期变化的音调熵 (t-e) 分析，表明建立自主功能的比较量表的可能性，该方法的有效性已经在典型的生理情况下进行了检验 (Oida等。在J Appl Physiol 82:1794-1801中，1997; Oida等人在J Gerontol 54A:M219-M224，1999a; Oida等人在《物理学报》Scand 165:129-134，1999b; Oida等人在《物理学报》Scand 165:421-422，1999c; Amano等人在Eur J Appl Physiol 94:602-610，2005)。在这项研究中，通过t-e分析以及常规的时域和频域分析，对276名青少年至70岁的受试者进行了静息检查。音调 (负性代表迷走神经占优势) 变得显著高 [-0.174 +/- 0.026 (青少年) 至-0.024 +/- 0.004 (七十年代)，P <0.05单因素方差分析] 和熵 (总自主活动)，随着年龄的增长，显着降低 [4.40/- 0.12 (青少年) 至2.90/- 0.09位 (70岁)，P <0.05]。在2-D T-E空间中绘制的结果表明，衰老从右下到左上具有曲线线性关系，并且与先前研究的典型生理情况一致。常规分析显示出与t-e几乎相同的自主神经降低，但未能检测到自主神经平衡的微妙变化。结果表明，随着年龄的增长，两种途径的自主神经活动均降低，从而显着损害了迷走神经的优势，这表明有可能以比较的方式评估2-D t-e空间中的自主神经功能。

BACKGROUND & AIMS: OBJECTIVE:Traditional definition of sample entropy (SampEn), here referred to as global SampEn (GSampEn), provides a conditional entropy estimate that blurs the local statistical properties of the time series. We hypothesized that a local version of SampEn (LSampEn) might be more powerful in the presence of determinism than GSampEn. METHODS:LSampEn was computed by calculating the probability of the current sample conditioned on each reference pattern and averaging it over all reference patterns. The improved ability of LSampEn compared to GSampEn was demonstrated by simulating deterministic periodic, deterministic chaotic, and linear stochastic dynamics corrupted by additive noise and over real cardiovascular variability series recorded from 16 healthy subjects (max-min age range: 22-58 years) during incremental bicycle ergometer exercise. RESULTS:We found that: i) LSampEn is more robust in describing deterministic periodic or nonlinear features in the presence of additive noise than GSampEn, ii) in association with a surrogate approach, LSampEn is more powerful in detecting nonlinear dynamics than GSampEn, iii) LSampEn and GSampEn are equivalent in the presence of stochastic linear dynamics, and iv) only LSampEn can detect the decrease of complexity of heart period variability during bicycle exercise being a likely hallmark of sympathetic activation. CONCLUSION:LSampEn preserves the GSampEn capability in characterizing the complexity of short sequences but improves its reliability in the presence of deterministic patterns featuring sharp state transitions and nonlinear dynamics. SIGNIFICANCE:Variations of complexity can be measured with a greater statistical power over short series using LSampEn, especially when nonlinear features are present.

背景与目标：