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1.
The modulation of protein-protein interactions (PPIs) by small molecules represents a valuable strategy for pharmacological intervention in several human diseases. In this context, computer-aided drug discovery techniques offer useful resources to predict the network of interactions governing the recognition process between protein partners, thus furnishing relevant information for the design of novel PPI modulators. In this work, we focused our attention on the MUC1-CIN85 complex as a crucial PPI controlling cancer progression and metastasis. MUC1 is a transmembrane glycoprotein whose extracellular domain contains a variable number of tandem repeats (VNTRs) regions that are highly glycosylated in normal cells and under-glycosylated in cancer. The hypo-glycosylation fosters the exposure of the backbone to new interactions with other proteins, such as CIN85, that alter the intracellular signalling in tumour cells. Herein, different computational approaches were combined to investigate the molecular recognition pattern of MUC1-CIN85 PPI thus unveiling new structural information useful for the design of MUC1-CIN85 PPI inhibitors as potential anti-metastatic agents.  相似文献   
2.
《Ceramics International》2022,48(13):18151-18156
The electrical properties and domain reversal in BiFeO3 ferroelectric films were studied using sandwiched heterostructures and piezoresponse force microscopy. A robust polarization state was observed, combined with a switchable domain pattern and a remanent polarization of approximately 100 μC cm?2. In addition, domain reversal was explored using scanning probe microscopy. The results show that dipoles could be reversed along the direction of the electric field under a negative tip bias, leading to carrier gathering near the domain walls. The enhanced conductivity near the domain walls was owing to the discontinuous polarization boundary conditions. In addition, typical diode-like current transport properties are sensitive to various temperature conditions, which is attributed to the Schottky barriers at the contact interface. These findings extend the current understanding of domain texture reversal in ferroelectric films and shed light on their potential applications for future ferroelectric random-access memory operations over a wide temperature range.  相似文献   
3.
正演波场的储存或重建是制约时间域全波形反演的关键问题,以计算代替存储的常规分裂完全匹配层(PML)边界存储策略可有效减少存储量。但常规分裂PML边界条件所需变量个数多、计算存储量大以及编程复杂。为此,采用非分裂复频移完全匹配层(CFS-NPML)有效边界存储策略重建正演波场实现时间域全波形反演。研究表明:CFS-NPML所需变量个数少,在边界吸收层网格点较少时吸收效果优于常规PML边界条件,波场重建过程中所需存储量少于常规PML边界条件。数值试验表明,该存储策略得到的重建波场与正向传播波场几乎无差别,其全波形反演结果与常规保存波场反演法一致;正演过程中引入并行计算技术未显著增加波场重建导致的额外正演时间。  相似文献   
4.
现有的致密气和煤层气联合开发选区评价方法存在着方法通用性不强、储量与储层物性等参数不能反映两气联采产量差异等问题。为此,以建立致密气和煤层气两气联采通用量化评价指标体系为目的,定义了两气联采有利区综合评价系数,以两气联采产量为评价目标,采用正交设计结合数值模拟手段,确定影响联采产量的关键参数及其对产量的影响程度,建立了两气联采开发选区量化评价新方法,并将新方法应用于鄂尔多斯盆地东缘KNW矿区的两气联采开发选区评价实践中。结果表明:(1)新方法建立和确定了两气地质赋存模式、关键评价参数及正交试验方案设计、评价参数对产量的影响程度、两气联采有利区综合评价系数等;(2)采用优选出的12个关键参数对KNW矿区两气联采开发选区的量化评价结果显示,该矿区南部、北部KNW-37井区为单采煤层气有利区,矿区内的KNW-10、KNW-33、KNW-9井区为单采致密气有利区,矿区中部和西南部为两气联采有利区。结论认为,所提出的致密气和煤层气联合开发选区量化评价新方法具有通用性,对两气联采开发选区具有参考意义。  相似文献   
5.
6.
在野外露头和岩心观察基础上,通过力学分析,对重庆下古生界页岩中顺层滑脱变形域的类型、特征及其形成进行了研究,并结合页岩气勘探实践,对其地质意义进行了探讨。顺层滑脱变形域包括挤压型和重力型两类。挤压型顺层滑脱变形域形成时水平挤压构造应力占主导地位,岩层发生“逆断层”运动;重力型顺层滑脱变形域形成时上覆地层压力占主导地位,岩层发生"正断层"运动。挤压型顺层滑脱变形域地层变形相对较强,影响范围相对较大。埋藏深度和岩层倾角是控制同一地区同一页岩层中顺层滑脱变形域形成的关键地质要素。页岩埋深越大,形成挤压型顺层滑脱变形域时的临界岩层倾角越大,而形成重力型顺层滑脱变形域的临界岩层倾角则越小。重力型顺层滑脱变形域破坏页岩气保存条件。背斜构造部位挤压型顺层滑脱变形域所形成的顺层破碎带和网状裂缝系统是页岩气重要的运移通道和储集空间,向斜构造部位挤压型顺层滑脱变形域所形成的顺层破碎带和网状裂缝系统成为页岩气向临近背斜构造部位运移或向地表散失的重要通道。  相似文献   
7.
高斯束偏移不仅具有接近波动方程偏移的精度,而且具有Kirchhoff偏移灵活、高效的特点。然而当实际地震采集数据中含有较强噪声时,易产生偏移假象而影响成像质量。为此,在传统高斯束偏移的基础上,根据有效信号和干扰信号在τ-p域中的相干性差异,发展了一种基于相似系数阈值滤波的数据驱动控制束偏移方法。采用数据驱动策略,在高斯束偏移成像过程中,先计算τ-p道集的相似系数,再通过设定相似系数阈值控制干扰信号,从而降低偏移剖面中的随机噪声;控制束偏移可以直接提取角度域共成像点道集,无需复杂的角度映射变换且具有更高信噪比。模型测试及实际资料处理结果表明:对于低信噪比数据,控制束偏移剖面的信噪比明显高于常规高斯束偏移,但会损失相对振幅的可靠性;尽管控制束偏移在τ-p道集的滤波过程增加了一定的计算量,但总体与常规高斯束偏移方法的计算效率相当;相似系数阈值参数选取十分关键,阈值较小时偏移噪声较强,但过大阈值也可能压制部分有效信息或产生偏移假象,选取合适的阈值参数才能得到较理想的偏移剖面。  相似文献   
8.
混叠采集技术能极大地提高地震采集效率,但是由于连续激发,混采数据中存在严重的邻炮干扰噪声,而且混采数据规模巨大,这要求后续的信噪分离算法精确、稳定、快速,为此提出一种基于稀疏反演的高效混采数据分离方法。在三维共检波点道集上,首先通过三维快速傅里叶变换,将时空域数据变换到频率-波数-波数域(FKK);然后采用硬阈值函数提取相干信号,利用相干信号预测混叠噪声;最后以数据残差为驱动,不断收缩阈值,迭代更新模型,实现高效混采数据分离。模拟数据和实际数据应用结果表明,本文方法能够精确、稳定、快速地分离高混叠度的地震数据。  相似文献   
9.
Hexagonal rare-earth ferrites (h-RFeO3) have attracted much scientific attention due to their room-temperature multiferroicity. However, it is still a hard job to obtain h-RFeO3 bulk materials because of the meta-stability of such hexagonal phase, and the evaluation of room-temperature ferroelectric and magnetoelectric characteristics in such materials is also a challengeable issue. In the present work, Yb1−xInxFeO3 ceramics with the stable hexagonal structure were obtained by introducing chemical pressure, where the unique ferroelectric domain structures of sixfold vortex combined with tenfold vortex with a typical size of ~400 nm were determined. Symmetry of the present system evolved from centrosymmetric orthorhombic Pbnm (x = 0–0.4) to non-centrosymmetric hexagonal P63cm (x = 0.5 and 0.6) with a ferroelectric polarization up to 3.2 μC/cm2, and finally to centrosymmetric hexagonal P63/mmc (x = 0.7 and 0.8). The Curie point decreased monotonically from 723 K to a temperature below room temperature with increasing x, and the antiferromagnetic phase transition above room temperature was determined for all compositions. Meanwhile, a large linear magnetoelectric coefficient (αME) up to 0.96 mV/cm Oe was obtained at room temperature, and this indicated the great application potential for magnetoelectric devices.  相似文献   
10.
A Quantitative Critical Thinking (QCT) software tool was developed in this study to facilitate students’ learning of quantitative critical thinking via repeated practice by chemical engineering students reading a core module called fluid-solid systems. The software tool generated detailed calculation steps to typical engineering design problems encountered in this module that contained weaknesses, flaws or even errors. Students utilized the software tool to practice identifying these weaknesses, flaws or errors in the design solutions and then present a better or correct design by applying the concepts and knowledge acquired in the module. Since the QCT software tool was built upon an existing design software tool that was able to generate the correct, detailed design calculation steps to design problems, students were able to check their own design calculations against those presented by the software tool during this second learning step, thereby engaging in and learning quantitative critical thinking via a repeated practice approach. The software tool was successful in enhancing the performance of second-year undergraduate students in solving a question that required quantitative critical thinking in the final examination of the module. The average percentage scores achieved by students for the question who reported higher frequencies of usage of the software were generally higher than those who reported lower frequencies of usage or did not utilize the software tool throughout the semester.  相似文献   
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