cluster model

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    文章类型: Journal Article
    随机对照试验(RCT)是评估人类受试者治疗性干预措施有效性和安全性的金标准。除了预先指定的端点之外,试验参与者的经验揭示了干预的时间过程。很少有分析工具可以总结和可视化试验参与者的个人经历。视觉分析允许对患者体验的时间事件模式进行综合检查,从而为更好的护理决策提供见解。为此,我们介绍TrialView,结合图形人工智能(AI)和可视化分析的信息系统,以增强试验数据的传播。TrialView提供了四个不同但相互关联的视图:个人,队列,Progression,统计,实现对个人和组级数据的交互式探索。TrialView系统是广泛的临床试验的通用分析工具。该系统由图形AI提供动力,知识引导聚类,解释性建模,和基于图的凝聚算法。我们通过案例研究证明了系统在分析时态事件数据方面的有效性。
    Randomized controlled trials (RCT) are the gold standards for evaluating the efficacy and safety of therapeutic interventions in human subjects. In addition to the pre-specified endpoints, trial participants\' experience reveals the time course of the intervention. Few analytical tools exist to summarize and visualize the individual experience of trial participants. Visual analytics allows integrative examination of temporal event patterns of patient experience, thus generating insights for better care decisions. Towards this end, we introduce TrialView, an information system that combines graph artificial intelligence (AI) and visual analytics to enhance the dissemination of trial data. TrialView offers four distinct yet interconnected views: Individual, Cohort, Progression, and Statistics, enabling an interactive exploration of individual and group-level data. The TrialView system is a general-purpose analytical tool for a broad class of clinical trials. The system is powered by graph AI, knowledge-guided clustering, explanatory modeling, and graph-based agglomeration algorithms. We demonstrate the system\'s effectiveness in analyzing temporal event data through a case study.
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  • 文章类型: Journal Article
    在这项工作中,使用计算光谱学方法来提供三种标题烷氧基硅烷衍生物-3-氨基丙基三甲氧基硅烷(APTS)的非弹性中子散射光谱的完整分配,N-甲基-3-氨基丙基三甲氧基硅烷(MAPTS),和3-氨基丙基三乙氧基硅烷(APTES)。从密度泛函理论(DFT)计算获得的模拟光谱与实验光谱显着匹配。实验谱带的描述随着理论模型中考虑的分子数量的增加而改善,从单体到三聚体。这突出了结合非共价相互作用的重要性,包含经典的NH···N,N-H···O,以及C-H···N和C-H·····O氢键接触,实现对系统的全面理解。当考虑光学振动技术时,会出现一个不同的场景,红外和拉曼光谱。在这些情况下,单体模型提供了实验光谱的合理描述,使用二聚体和三聚体模型时,在模拟光谱中未观察到实质性变化。这一观察结果强调了中子光谱学结合DFT计算在评估分子材料的结构和动力学方面的独特能力。
    In this work, a computational spectroscopy approach was used to provide a complete assignment of the inelastic neutron scattering spectra of three title alkoxysilane derivatives-3-aminopropyltrimethoxysilane (APTS), N-methyl-3-aminopropyltrimethoxysilane (MAPTS), and 3-aminopropyltriethoxysilane (APTES). The simulated spectra obtained from density functional theory (DFT) calculations exhibit a remarkable match with the experimental spectra. The description of the experimental band profiles improves as the number of molecules considered in the theoretical model increases, from monomers to trimers. This highlights the significance of incorporating non-covalent interactions, encompassing classical NH···N, N-H···O, as well as C-H···N and C-H···O hydrogen bond contacts, to achieve a comprehensive understanding of the system. A distinct scenario emerges when considering optical vibrational techniques, infrared and Raman spectroscopy. In these instances, the monomer model provides a reasonable description of the experimental spectra, and no substantial alterations are observed in the simulated spectra when employing dimer and trimer models. This observation underscores the distinctive ability of neutron spectroscopy in combination with DFT calculations in assessing the structure and dynamics of molecular materials.
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  • 文章类型: Journal Article
    在这项研究中,锆基金属有机骨架(UiO-66)与基于双(三氟甲磺酰基)酰亚胺阴离子(EMIM+,BMIM+和OMIM+)通过组合的实验和计算方法进行。合成了负载离子液体的UiO-66或IL@UiO-66并对其进行表征以理解主客体相互作用。进行密度泛函理论计算以分析IL@UiO-66的电子结构,以提供对杂化材料中发生的主要相互作用的分子洞察力。结果表明,所有IL都成功地结合到UiO-66的微孔中。如从XRD图分析的,即使在加载IL之后,3D框架仍被保留。FTIR光谱显示IL与UiO-66的相互作用受阳离子的烷基链长度的影响。由于电负性原子的存在,阴离子与UiO-66具有深远的亲和力。DSC的相变研究表明,IL的掺入通过将吸热峰移至更高的状态来稳定UiO-66的骨架。通过DFT计算进一步阐述了这些发现。几何优化确认了加载IL时UiO-66的结构参数变化。这些主要是由减少的密度梯度散点图证实的非共价相互作用贡献的。另一个重要发现是主-客体界面处的氢键强度受烷基链长度的影响。分子轨道分析还表明,烷基链的大小会影响杂化材料的反应性。本研究提供了关于UiO-66和IL作为杂化材料的分子相互作用的基本见解,这可以为储能系统中金属有机框架应用的先进材料开辟新的可能性,催化作用,气体储存和药物化学。
    In this study, the physicochemical properties and molecular interactions between zirconium-based metal-organic framework (UiO-66) and three different ionic liquids based on bis(trifluoromethanesulfonyl)imide anion (EMIM+, BMIM+ and OMIM+) was performed via a combined experimental and computational approach. The ionic liquid loaded UiO-66 or IL@UiO-66 was synthesized and characterized to understand the host-guest interaction. Density functional theory calculation was performed to analyse the electronic structure of IL@UiO-66 to provide molecular insight on the dominant interactions occurred in the hybrid material. Results showed that all ILs were successfully incorporated into the micropores of UiO-66. The 3D framework was retained even after loaded with ILs as analyzed from XRD pattern. FTIR spectrum reveals that interactions of ILs with UiO-66 influenced by the alkyl chain length of the cation. The anion has a profound affinity with the UiO-66 due to the presence of electronegative atoms. Phase transition study from DSC suggested that the incorporation of ILs has stabilized the framework of UiO-66 by shifting the endothermic peak to a higher state. These findings were further elaborated with DFT calculation. Geometrical optimizations confirmed the structural parameter changes of UiO-66 when loaded with ILs. These was mainly contributed by the non-covalent interactions which was confirmed by the reduced density gradient scattered plot. Another important findings are the strength of hydrogen bonding at the host-guest interface was influenced by the alkyl chain length. The molecular orbital analysis also shows that the size of alkyl chain influence the reactivity of the hybrid material. The present study provides fundamental insights on the molecular interaction of UiO-66 and ILs as a hybrid material, which can open new possibilities for advanced material for metal-organic framework applications in energy storage system, catalysis, gas storage and medicinal chemistry.
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  • 文章类型: Journal Article
    背景技术随着移动设备和定位技术的快速发展,基于位置的服务(LBS)得到了广泛的应用。用户通常向LBS提供精确的位置信息以访问相应的服务。然而,这种便利伴随着位置隐私泄露的风险,这可能会侵犯个人隐私和安全。在本文中,提出了一种基于差分隐私的位置隐私保护方法,有效地保护用户的位置,不会降低LBS的性能。首先,提出了一种位置聚类(L-clustering)算法,根据多组间的距离和密度关系将连续位置划分为不同的簇。然后,提出了一种基于差分隐私的位置隐私保护算法(DPLPA)来保护用户的位置隐私,其中拉普拉斯噪声被添加到集群内的常驻点和质心。实验结果表明,DPLPA实现了较高的数据效用,用最少的时间消耗,同时有效保护位置信息的隐私。
    Location-based services (LBS) are widely used due to the rapid development of mobile devices and location technology. Users usually provide precise location information to LBS to access the corresponding services. However, this convenience comes with the risk of location privacy disclosure, which can infringe upon personal privacy and security. In this paper, a location privacy protection method based on differential privacy is proposed, which efficiently protects users\' locations, without degrading the performance of LBS. First, a location-clustering (L-clustering) algorithm is proposed to divide the continuous locations into different clusters based on the distance and density relationships among multiple groups. Then, a differential privacy-based location privacy protection algorithm (DPLPA) is proposed to protect users\' location privacy, where Laplace noise is added to the resident points and centroids within the cluster. The experimental results show that the DPLPA achieves a high level of data utility, with minimal time consumption, while effectively protecting the privacy of location information.
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  • 文章类型: Journal Article
    在高移动性信道的信道建模过程中,如高速列车(HST)通道,假定移动无线电台的速度是恒定的。然而,由于列车沿轨道的动态运动,这可能是不现实的。因此,在本文中,提出了一种基于3D非平稳几何随机模型(GBSM)的增强型高斯-马尔可夫移动模型,用于MIMO无线信道中的HST。假定簇内的非各向同性散射体围绕移动中继站(MRS)所在的球体。多路径分量(MPC)用不同的速度建模,而移动性模型是时间的函数。使用马尔可夫过程将MPC表示为死亡-出生集群。此外,频道统计,即,时空相关函数,均方根多普勒频移,和准平稳区间,是从非平稳模型中得出的。该模型显示了准平稳时间如何从0.21s增加到0.451s,而HST的加速度减小为0.6到0.2m/s2。此外,介绍了角度分布对信道统计的影响。最后,将模拟结果与实测结果进行比较。因此,提出的模型与实测结果之间存在密切的关系,并且该模型可用于表征通道的属性。
    During channel modeling for high-mobility channels, such as high-speed train (HST) channels, the velocity of the mobile radio station is assumed to be constant. However, this might not be realistic due to the dynamic movement of the train along the track. Therefore, in this paper, an enhanced Gauss-Markov mobility model with a 3D non-stationary geometry based stochastic model (GBSM) for HST in MIMO Wireless Channels is proposed. The non-isotropic scatterers within a cluster are assumed to be around the sphere in which the mobile relay station (MRS) is located. The multi-path components (MPCs) are modeled with varying velocities, whereas the mobility model is a function of time. The MPCs are represented in a death-birth cluster using the Markov process. Furthermore, the channel statistics, i.e., the space-time correlation function, the root-mean-square Doppler shift, and the quasi-stationary interval, are derived from the non-stationary model. The model shows how the quasi-stationary time increases from 0.21 to 0.451 s with a decreasing acceleration of 0.6 to 0.2 m/s2 of the HST. In addition, the impact of the distribution of the angles on the channel statistics is presented. Finally, the simulated results are compared with the measured results. Therefore, there is a close relationship between the proposed model and the measured results, and the model can be used to characterize the channel\'s properties.
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  • 文章类型: Journal Article
    漆酶被认为是多功能的绿色生物催化剂,和最近的科学研究集中在提高其氧化还原电位为更广泛的工业和环境应用。密度泛函理论(DFT)量子力学方法,足够严格和有效的电子结构的计算,进行是为了更好地理解氧化还原电位与漆酶的原子结构特征之间的联系。根据野生型漆酶CueO及其变体的晶体结构,本研究建立了截断的微型聚类模型方法。在热力循环的基础上,计算了单电子还原前后的总体吉布斯自由能变化。结果表明,通过理论计算预测的变化后氧化还原电位的增加趋势与实验获得的趋势密切相关。从而验证了该簇模型方法模拟漆酶氧化还原电位的可行性。
    Laccases are regarded as versatile green biocatalysts, and recent scientific research has focused on improving their redox potential for broader industrial and environmental applications. The density functional theory (DFT) quantum mechanics approach, sufficiently rigorous and efficient for the calculation of electronic structures, is conducted to better comprehend the connection between the redox potential and the atomic structural feature of laccases. According to the crystal structure of wild type laccase CueO and its variant, a truncated miniature cluster model method was established in this research. On the basic of thermodynamic cycle, the overall Gibbs free energy variations before and after the one-electron reduction were calculated. It turned out that the trends of redox potentials to increase after variant predicted by the theoretical calculations correlated well with those obtained by experiments, thereby validating the feasibility of this cluster model method for simulating the redox potentials of laccases.
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  • 文章类型: Journal Article
    该研究证实了俄罗斯医疗保健系统发展集群方法的可能性。通过对国外医疗集群运作经验的分析,可以确定有助于其成功发展的因素。根据对国内医疗行业创建集群实践的评估,他们的典型是通过确定生物医学技术和创新的高科技集群来进行的,药品供应和专用设备的医疗集群,医疗服务集群,实习和医学创新的转移。根据拟议的类型对俄罗斯联邦医疗保健部门的集群进行分组表明,实际上没有医疗服务集群能够将该国人口的医疗质量提高到更高的水平。本文确定了阻止在该地区领土上形成医疗服务集群的问题。为了解决这些问题,提出了一种在公私伙伴关系的基础上创建医疗科技园的方法,它将作为医疗服务集群的基础,并建立其结构和功能模型。
    The study substantiates the possibility of the cluster approach for the development of the healthcare system in Russia. The analysis of foreign experience in the functioning of medical clusters made it possible to identify factors that contribute to their successful development. Based on the assessment of the domestic practice of creating clusters in the healthcare sector, their typification was carried out with the identification of groups of high-tech clusters of biomedical technologies and innovations, medical clusters of drug provision and specialized equipment, clusters of medical services, internships and transfer of medical innovations. The grouping of clusters in the healthcare sector operating in the Russian Federation according to the proposed types showed that there are practically no clusters of medical services that are able to bring the quality of medical care to the population to a higher level in the country. The article identifies the problems that prevent the formation of clusters of medical services on the territory of the regions. To solve these problems, an approach was proposed to create a medical technology park on the basis of public-private partnership, which will serve as the basis for a cluster of medical services and built its structural and functional model.
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  • 文章类型: Journal Article
    淀粉是葡萄糖的不溶于水的聚合物,在植物细胞的质体基质内合成为离散的颗粒。淀粉储备为立即生长和发育提供了碳水化合物的来源,并在胚乳和种子组织中长期储存碳,以促进下一代的生长,制作具有巨大农业重要性的淀粉。淀粉颗粒具有高度复杂的分层结构,这是由大量酶的组合作用以及物理化学自组装机制引起的。了解颗粒结构的精确性质,生物因素和非生物因素如何决定这种结构具有根本性和实际意义。这篇综述概述了与淀粉结构的结构单元-主链模型有关的颗粒结构和淀粉生物合成途径的最新知识。我们强调我们的知识与我们对淀粉的结构和合成的理解有关的差距,并认为构建块-骨架模型准确地考虑了结构和生化数据。
    Starch is a water-insoluble polymer of glucose synthesized as discrete granules inside the stroma of plastids in plant cells. Starch reserves provide a source of carbohydrate for immediate growth and development, and act as long term carbon stores in endosperms and seed tissues for growth of the next generation, making starch of huge agricultural importance. The starch granule has a highly complex hierarchical structure arising from the combined actions of a large array of enzymes as well as physicochemical self-assembly mechanisms. Understanding the precise nature of granule architecture, and how both biological and abiotic factors determine this structure is of both fundamental and practical importance. This review outlines current knowledge of granule architecture and the starch biosynthesis pathway in relation to the building block-backbone model of starch structure. We highlight the gaps in our knowledge in relation to our understanding of the structure and synthesis of starch, and argue that the building block-backbone model takes accurate account of both structural and biochemical data.
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  • 文章类型: Journal Article
    We present the study of the phosphorus local environment by using 31P MAS NMR in a series of seven double monophosphates MIIMIV(PO4)2 (MII and MIV being divalent and tetravalent cations, respectively) of yavapaiite and low-yavapaiite type crystal structures. Solid-state and cluster DFT calculations were found to be efficient for predicting the 31P isotropic chemical shift and chemical shift anisotropy. To achieve this performance, however, a proper computational optimisation of the experimental structural data was required. From the three optimisation methods tested, the full optimisation provided the best reference structure for the calculation of the NMR parameters of the studied phosphates. Also, a better prediction of the chemical shifts was possible by using a correction to the GIPAW calculated shielding.
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  • 文章类型: Journal Article
    探讨合并化疗和放疗的头颈部患者腮腺正常组织并发症概率(NTCP)模型。建立了融合腮腺空间剂量分布的聚类模型,以评估辐射引起的并发症。针对基准NTCP评估并仔细检查了包括平均簇大小(NMCS)和最大簇大小的簇指标,这些簇指标均由腺体体积(NSLC)标准化。设计了使用最大似然方法对Lyman-Kutcher-Burman(LKB)模型的两种拟合策略:体积参数n固定为1.0(平均剂量模型)和无限制(完整LKB模型)。拟合参数TD50和m用LKBNTCP模型和可用的口干症数据进行评估。根据LKB模型,NSLC是比NMCS更好的度量标准,并且在NTCP和NSLC之间观察到强相关性(r〜0.95)。平均剂量模型从约40Gy的阈值剂量的NSLC返回参数TD50(39.9Gy)和m(0.4)。通过完整的LKB模型从拟合中获得了截然不同的TD50和m值,阈值剂量将接近27Gy。自举分析进一步证实了拟合结果。与传统NTCP模型的强相关性表明,集群模型可以实现NTCP模型所达到的目标,并可能提供其他信息。模型的参数化表明该模型可能具有与当前临床建议不同的预测。正在使用毒性数据进行进一步的调查,以验证集群模型。
    To explore the parotid normal tissue complication probability (NTCP) modeling with percolation-based dose clusters for head-and-neck patients receiving concomitant chemotherapy and radiation therapy. Cluster models incorporating the spatial dose distribution in the parotid gland were developed to evaluate the radiation induced complication. Cluster metrics including the mean cluster size (NMCS) and the largest cluster size both normalized by the gland volume (NSLC) were evaluated and scrutinized against the benchmark NTCP. Two fitting strategies to the Lyman-Kutcher-Burman (LKB) model using the maximum likelihood method were devised: the volume parameter n fixed at 1.0 (mean dose model) and unrestricted (full LKB model). The fitted parameters TD50 and m were assessed with the LKB NTCP models with the available xerostomia data. NSLC was a better metric than NMCS with reference to the LKB model and strong correlation (r ~ 0.95) was observed between NTCP and NSLC. The mean dose model returned the parameter TD50 (39.9 Gy) and m (0.4) from the NSLC of threshold dose at around 40 Gy. Drastically different TD50 and m values were obtained from the fittings via the full LKB model, where the threshold dose would be near 27 Gy. Bootstrapping analyses further confirmed the fitting outcomes. Strong correlation with the traditional NTCP models revealed that the cluster model could achieve what NTCP models attain and may offer additional information. Parameterization of the model indicated that the model could have different predictions from current clinical recommendations. Further investigation using toxicity data is under way to validate the cluster model.
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