computational

计算
  • 文章类型: Journal Article
    目的:本研究旨在通过回顾性研究验证一组癫痫发作易感性的候选生物标志物,多点病例对照研究,并确定从常规收集的脑电图(EEG)中大量队列(包括癫痫和常见的替代疾病,例如非癫痫发作障碍)中得出的这些生物标志物的稳健性。
    方法:数据库由来自648名受试者的814个脑电图记录组成,从英国八个国家卫生服务机构收集。临床非贡献脑电图记录由经验丰富的临床科学家鉴定(N=281;152替代条件,129癫痫)。八个计算标记(光谱[n=2],基于网络的[n=4],和基于模型的[n=2])在每个记录中计算。使用两层交叉验证方法开发了基于集成的分类器。我们使用标准回归方法来评估潜在的混杂变量(例如,年龄,性别,治疗状态,合并症)影响模型性能。
    结果:我们发现,在具有临床非贡献性正常脑电图的队列中,平衡准确率为68%(灵敏度=61%,特异性=75%,阳性预测值=55%,阴性预测值=79%,诊断比值比=4.64,接受者操作特征曲线下面积=0.72)。小组水平分析发现,没有证据表明任何潜在的混杂变量显着影响整体绩效。
    结论:这些结果提供了证据,表明该组生物标志物可以为临床决策提供额外价值,为减少诊断延迟和误诊率的决策支持工具提供基础。因此,未来的工作应该评估在精心设计的前瞻性研究中利用这些生物标志物时诊断产量和诊断时间的变化。
    OBJECTIVE: This study was undertaken to validate a set of candidate biomarkers of seizure susceptibility in a retrospective, multisite case-control study, and to determine the robustness of these biomarkers derived from routinely collected electroencephalography (EEG) within a large cohort (both epilepsy and common alternative conditions such as nonepileptic attack disorder).
    METHODS: The database consisted of 814 EEG recordings from 648 subjects, collected from eight National Health Service sites across the UK. Clinically noncontributory EEG recordings were identified by an experienced clinical scientist (N = 281; 152 alternative conditions, 129 epilepsy). Eight computational markers (spectral [n = 2], network-based [n = 4], and model-based [n = 2]) were calculated within each recording. Ensemble-based classifiers were developed using a two-tier cross-validation approach. We used standard regression methods to assess whether potential confounding variables (e.g., age, gender, treatment status, comorbidity) impacted model performance.
    RESULTS: We found levels of balanced accuracy of 68% across the cohort with clinically noncontributory normal EEGs (sensitivity =61%, specificity =75%, positive predictive value =55%, negative predictive value =79%, diagnostic odds ratio =4.64, area under receiver operated characteristics curve =.72). Group level analysis found no evidence suggesting any of the potential confounding variables significantly impacted the overall performance.
    CONCLUSIONS: These results provide evidence that the set of biomarkers could provide additional value to clinical decision-making, providing the foundation for a decision support tool that could reduce diagnostic delay and misdiagnosis rates. Future work should therefore assess the change in diagnostic yield and time to diagnosis when utilizing these biomarkers in carefully designed prospective studies.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    整容手术越来越实惠和容易获得,但是会带来生理和心理上的风险。然而,迄今为止,还没有一项研究直接检查在受控条件下的冒险行为,超越自我报告和整容手术态度。我们使用气球模拟风险任务和先进的计算模型来衡量决策行为,并确定与没有整容手术史的女性(N=265)和具有整容手术史的女性子样本(N=24)的整容手术态度相关的潜在参数驱动行为。接受和有整容手术史的女性风险更高。计算模型显示,当在更了解损失(风险)的情况下做出决定时,而不是在损失的可能性未知(不确定性)时,女性接受整容手术的风险增加。当接受整容手术的女性做出决定时,他们也不太重视可能的损失(减少损失厌恶)。我们的发现表明,寻求整容手术的女性可能对损失不太敏感,因此做出了更多的风险决定。应更加重视沟通潜在的损失,而不仅仅是考虑整容手术的女性的相关风险。没有级别分配本期刊要求作者为适用于循证医学排名的每个提交分配一个级别的证据。这不包括评论文章,书评,和有关基础科学的手稿,动物研究,尸体研究,和实验研究。对于这些循证医学评级的完整描述,请参阅目录或在线作者说明www。springer.com/00266.
    Cosmetic surgery is ever more affordable and accessible, but carries physical and psychological risks. Yet, no study to date has directly examined risk-taking behaviour under controlled conditions, beyond self-report and in relation to cosmetic surgery attitudes. We used the Balloon Analogue Risk Task and advanced computational modelling to measure decision-making behaviour and identify the latent parameters driving behaviour associated with cosmetic surgery attitudes in women with no cosmetic surgery history (N = 265) and a subsample of women with a cosmetic surgery history (N = 24). Risk taking was higher in women with greater acceptance and history of cosmetic surgery. Computational modelling revealed increased risk taking in women with greater acceptance of cosmetic surgery when decisions were made with greater knowledge of loss (risk) and not when the likelihood of loss was unknown (uncertainty). When women with greater acceptance of cosmetic surgery made decisions, they also placed less emphasis on possible losses (reduced loss aversion). Our findings suggest that women seeking cosmetic procedures may be less sensitive to losses and thus make more risky decisions. Greater emphasis should be placed on communicating potential losses rather than just the associated risks to women considering cosmetic procedures.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Review
    这篇评论为对神经网络感兴趣的社会神经科学家提供了可访问的入门。首先概述了深度学习中的关键概念。然后讨论了神经网络对社会神经科学家有用的三种方式:i)建立统计模型以预测大脑活动的行为;ii)量化自然主义刺激和社会互动;iii)生成社会大脑功能的认知模型。这些应用有可能增强神经影像学的临床价值,并提高社会神经科学研究的普遍性。我们还讨论了重大的实际挑战,理论上的局限性,以及深度学习所面临的伦理问题。如果该领域能够成功导航这些危险,我们相信,人工神经网络对于该领域的下一个发展阶段是不可或缺的:深度社会神经科学。
    This review offers an accessible primer to social neuroscientists interested in neural networks. It begins by providing an overview of key concepts in deep learning. It then discusses three ways neural networks can be useful to social neuroscientists: (i) building statistical models to predict behavior from brain activity; (ii) quantifying naturalistic stimuli and social interactions; and (iii) generating cognitive models of social brain function. These applications have the potential to enhance the clinical value of neuroimaging and improve the generalizability of social neuroscience research. We also discuss the significant practical challenges, theoretical limitations and ethical issues faced by deep learning. If the field can successfully navigate these hazards, we believe that artificial neural networks may prove indispensable for the next stage of the field\'s development: deep social neuroscience.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    三奥汤(SAD)是一种著名的中药(TCM)配方,用于缓解呼吸道症状,包括哮喘.然而,其确切的作用机制在很大程度上仍然未知。在这项研究中,我们利用计算机辅助方法来探索这些机制。首先,我们对SAD的化学成分进行了全面的分析,这使我们能够确定28种主要成分。然后,我们采用计算机模拟研究了SAD的潜在活性成分和瞬时受体电位香草酸1(TRPV1)的相应结合位点.模拟显示D509和D647是TRPV1的潜在结合位点。值得注意的是,分子动力学(MD)研究表明,位点D509可能是TRPV1的变构位点。此外,为了验证计算机辅助预测,我们进行了实验研究,包括体外和体内测定。这些实验的结果证实了我们的计算模型所做的预测,为三奥汤治疗哮喘的作用机制提供了进一步的证据。我们的发现表明:i)TRPV1的D509和D647是SAD主要成分的关键结合位点;ii)SAD或其主要成分显着减少了Ca2通过TRPV1的流入,遵循“Jun”的中医原理,陈,左,Shi\";iii)SAD在全面的体内验证中显示出效率。总之,我们对三奥汤在哮喘治疗中的计算机辅助研究为该中药配方的治疗机制提供了有价值的见解。计算分析和实验验证的结合已被证明可以有效地增强我们对中医的理解,并可能为该领域的未来发现铺平道路。
    The San-Ao Decoction (SAD) is a well-known Traditional Chinese Medicine (TCM) formula used to alleviate respiratory symptoms, including asthma. However, its precise mechanisms of action have remained largely unknown. In this study, we utilized computer-aided approaches to explore these mechanisms. Firstly, we conducted a comprehensive analysis of the chemical composition of SAD, which allowed us to identify the 28 main ingredients. Then, we employed computer simulations to investigate the potential active ingredients of SAD and the corresponding binding sites of transient receptor potential vanilloid 1 (TRPV1). The simulations revealed that D509 and D647 were the potential binding sites for TRPV1. Notably, molecular dynamics (MD) studies indicated that site D509 may function as an allosteric site of TRPV1. Furthermore, to validate the computer-aided predictions, we performed experimental studies, including in vitro and in vivo assays. The results of these experiments confirmed the predictions made by our computational models, providing further evidence for the mechanisms of action of San-Ao Decoction in asthma treatment. Our findings demonstrated that: i) D509 and D647 of TRPV1 are the key binding sites for the main ingredients of SAD; ii) SAD or its main ingredients significantly reduce the influx of Ca2+ through TRPV1, following the TCM principle of \"Jun, Chen, Zuo, Shi\"; iii) SAD shows efficiency in comprehensive in vivo validation. In conclusion, our computer-aided investigation of San-Ao Decoction in asthma treatment has provided valuable insights into the therapeutic mechanisms of this TCM formula. The combination of computational analysis and experimental validation has proven effective in enhancing our understanding of TCM and may pave the way for future discoveries in the field.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    含有环状(烷基)(氨基)卡宾(CAAC)的以金为中心的卡宾-金属酰胺(CMA)是用于热激活延迟荧光(TADF)的有前途的发射体。针对新型TADF发射器的设计和优化,我们报告了对60多个具有各种CAAC配体的CMA的密度泛函理论研究,系统地评估与光致发光特性相关的计算参数。主要基于实验合成前景选择CMA结构。我们证明了CMA材料的TADF效率源于振荡器强度系数和交换能量(ΔEST)之间的折衷。后者由HOMO和LUMO轨道的重叠决定,其中HOMO位于酰胺上,LUMO位于Au-卡宾键上。CMA的S0基态和激发T1态采用卡宾和酰胺配体的近似共面几何形状,但在受激S1状态下垂直旋转,导致S1和T1的简并或接近简并,伴随着S1-S0振荡器强度从共面几何形状的最大值降低到旋转几何形状的接近于零。根据计算,提出并合成了有前途的新型TADF发射体。获得明亮的CMA配合物(Et2CAAC)Au(咔唑)并对其进行充分表征,以证明具有小CAAC-卡宾配体的金-CMA配合物可以获得优异的稳定性和高达106s-1的高辐射速率。
    Gold-centered carbene-metal-amides (CMAs) containing cyclic (alkyl)(amino)carbenes (CAACs) are promising emitters for thermally activated delayed fluorescence (TADF). Aiming at the design and optimization of new TADF emitters, we report a density functional theory study of over 60 CMAs with various CAAC ligands, systematically evaluating computed parameters in relation to photoluminescence properties. The CMA structures were primarily selected based on experimental synthesis prospects. We demonstrate that TADF efficiency of the CMA materials originates from a compromise between oscillator strength coefficients and exchange energy (ΔEST). The latter is governed by the overlap of HOMO and LUMO orbitals, where HOMO is localized on the amide and LUMO over the Au-carbene bond. The S0 ground and excited T1 states of the CMAs adopt approximately coplanar geometry of carbene and amide ligands, but rotate perpendicular in the excited S1 states, resulting in degeneracy or near-degeneracy of S1 and T1, accompanied by a decrease in the S1-S0 oscillator strength from its maximum at coplanar geometries to near zero at rotated geometries. Based on the computations, promising new TADF emitters are proposed and synthesized. Bright CMA complex (Et2CAAC)Au(carbazolide) is obtained and fully characterized in order to demonstrate that excellent stability and high radiative rates up to 106 s-1 can be obtained for the gold-CMA complexes with small CAAC-carbene ligands.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    不良结果途径(AOPs)总结了对毒理学效应的机理理解,例如,被强调为将新的体外和计算机模拟方法的数据整合到化学风险评估中的有前途的工具。基于AOP的网络被认为是AOP的功能实现,因为它们更能代表复杂的生物学。同时,目前没有统一的方法来生成AOP网络(AOPN)。确定相关AOPs的系统策略,以及从AOP-Wiki中提取和可视化数据的方法,是需要的。这项工作的目的是开发一种结构化的搜索策略,以识别AOP-Wiki中的相关AOP,和自动数据驱动的工作流程来生成AOPN。该方法应用于一个案例研究,以产生一个专注于雌激素的AOPN,雄激素,甲状腺,和类固醇生成(EATS)模式。根据ECHA/EFSA《内分泌干扰物鉴定指导文件》中的效果参数,先验地开发了一种搜索策略,其中包含搜索项。此外,通过筛选AOP-Wiki中每个途径的内容来进行数据的手动管理,排除不相关的AOP。数据是从Wiki下载的,计算工作流被用来自动处理,过滤器,并格式化数据以进行可视化。这项研究提出了一种在AOP-Wiki中对AOP进行结构化搜索的方法,该方法与自动数据驱动的工作流程相结合,以生成AOPN。此外,这里提供的案例研究提供了与EATS模式相关的AOP-Wiki内容的地图,也是进一步研究的基础,例如,整合来自新方法的机械数据,探索基于机制的方法来识别内分泌干扰物(ED)。计算方法可以作为R脚本免费获得,并且当前允许基于来自AOP-Wiki的数据和用于过滤的相关AOP列表来(重新)生成和过滤新的AOP网络。
    Adverse Outcome Pathways (AOPs) summarize mechanistic understanding of toxicological effects and have, for example, been highlighted as a promising tool to integrate data from novel in vitro and in silico methods into chemical risk assessments. Networks based on AOPs are considered the functional implementation of AOPs, as they are more representative of complex biology. At the same time, there are currently no harmonized approaches to generate AOP networks (AOPNs). Systematic strategies to identify relevant AOPs, and methods to extract and visualize data from the AOP-Wiki, are needed. The aim of this work was to develop a structured search strategy to identify relevant AOPs in the AOP-Wiki, and an automated data-driven workflow to generate AOPNs. The approach was applied on a case study to generate an AOPN focused on the Estrogen, Androgen, Thyroid, and Steroidogenesis (EATS) modalities. A search strategy was developed a priori with search terms based on effect parameters in the ECHA/EFSA Guidance Document on Identification of Endocrine Disruptors. Furthermore, manual curation of the data was performed by screening the contents of each pathway in the AOP-Wiki, excluding irrelevant AOPs. Data were downloaded from the Wiki, and a computational workflow was utilized to automatically process, filter, and format the data for visualization. This study presents an approach to structured searches of AOPs in the AOP-Wiki coupled to an automated data-driven workflow for generating AOPNs. In addition, the case study presented here provides a map of the contents of the AOP-Wiki related to the EATS-modalities, and a basis for further research, for example, on integrating mechanistic data from novel methods and exploring mechanism-based approaches to identify endocrine disruptors (EDs). The computational approach is freely available as an R-script, and currently allows for the (re)-generation and filtering of new AOP networks based on data from the AOP-Wiki and a list of relevant AOPs used for filtering.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    像Reddit这样的开放在线论坛提供了一个机会,可以在疫苗时间表的早期定量检查COVID-19疫苗的看法。我们在发布疫苗科学公告后,在Reddit上检查了COVID-19的错误信息,在疫苗时间表的初始阶段。
    我们收集了2020年1月1日至2020年12月14日Reddit(reddit.com)上所有包含COVID-19和疫苗相关关键字的帖子(n=266,840)。我们使用主题建模来了解疫苗试验数据发布后主题内单词流行率的变化。还进行了社会网络分析,以确定共享COVID-19疫苗帖子的Reddit社区(subreddits)之间的关系,以及subreddits之间的帖子移动。
    辉瑞公司的一份新闻稿报道了90%的效力,与关于疫苗错误信息的讨论增加之间存在关联。我们观察到约翰逊和约翰逊之间的关联暂时停止了疫苗试验,并减少了错误信息。我们发现,对疫苗接种持怀疑态度的信息首先发布在有利于准确信息的subreddit(r/Coronavirus)中,然后发布在与抗疫苗信念和阴谋论相关的subreddits中(例如,阴谋,NoNewNormal)。
    我们的发现可以为个人确定疫苗信息准确性的干预措施的发展提供信息。以及改善COVID-19疫苗认知的宣传活动,在疫苗时间表的早期。这种努力可以提高个人和人口对有关疫苗的准确和科学合理信息的认识,从而改善对疫苗的态度,尤其是在疫苗推出的早期阶段。需要进一步的研究来了解社交媒体如何为COVID-19疫苗接种服务做出贡献。
    Open online forums like Reddit provide an opportunity to quantitatively examine COVID-19 vaccine perceptions early in the vaccine timeline. We examine COVID-19 misinformation on Reddit following vaccine scientific announcements, in the initial phases of the vaccine timeline.
    We collected all posts on Reddit (reddit.com) from January 1 2020 - December 14 2020 (n=266,840) that contained both COVID-19 and vaccine-related keywords. We used topic modeling to understand changes in word prevalence within topics after the release of vaccine trial data. Social network analysis was also conducted to determine the relationship between Reddit communities (subreddits) that shared COVID-19 vaccine posts, and the movement of posts between subreddits.
    There was an association between a Pfizer press release reporting 90% efficacy and increased discussion on vaccine misinformation. We observed an association between Johnson and Johnson temporarily halting its vaccine trials and reduced misinformation. We found that information skeptical of vaccination was first posted in a subreddit (r/Coronavirus) which favored accurate information and then reposted in subreddits associated with antivaccine beliefs and conspiracy theories (e.g. conspiracy, NoNewNormal).
    Our findings can inform the development of interventions where individuals determine the accuracy of vaccine information, and communications campaigns to improve COVID-19 vaccine perceptions, early in the vaccine timeline. Such efforts can increase individual- and population-level awareness of accurate and scientifically sound information regarding vaccines and thereby improve attitudes about vaccines, especially in the early phases of vaccine roll-out. Further research is needed to understand how social media can contribute to COVID-19 vaccination services.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    通过密度泛函理论研究了各种含OH的分子在金红石TiO2(110)上的不同吸附方式。特别关注乙醇,乙二醇和甘油。分析了不同物种的吸附能,功函数,和原子Bader指控。我们的结果表明,在所有情况下都有利于解离吸附。在这些模式中,在双齿完全解离吸附的情况下观察到最强的结合,其次是双齿部分解离,然后是单齿解离模式。在电荷转移分析时也注意到这种依赖性。吸附有两个解离的OH基团的物种显示负电荷,与仅显示一个解离基团的物种相比,其电荷大约是其两倍大。在分子吸附的情况下,我们在吸附物上发现了一个小的正电荷。在所有研究的情况下,所获得的功函数变化均为负。我们观察到甘油(3OH基团),其次是乙二醇(2OH基团)和剩余的醇(1OH基团)的功函数变化更加消极的趋势,因此表明存在的OH基团的数量是功函数变化的重要因素。对于所研究的完整系列吸附物(甲醇,乙醇,异丙醇,乙二醇,甘油,过氧化氢和甲酸)对于分子吸附模式,功函数的变化与吸附能之间存在线性关系。对于相同系列的解离吸附模式,这种关系不太明显。
    A variety of OH containing molecules in their different modes of adsorption onto the rutile TiO2(110) are studied by means of density functional theory. A special focus is given to ethanol, ethylene glycol and glycerol. The different species were analyzed with respect to the adsorption energy, work function, and atomic Bader charges. Our results show that dissociated adsorption is favored in all cases. Within these modes, the strongest binding is observed in the case of bidentate fully dissociated adsorption, followed by bidentate partially dissociated then the monodentate dissociated modes. The dependence is also noted upon charge transfer analysis. Species adsorbing with two dissociated OH groups show a negative charge which is roughly twice as large compared to those exhibiting only one dissociated group. In the case of molecular adsorption, we find a small positive charge on the adsorbate. The change in work functions obtained is found to be negative in all studied cases. We observe a trend of the work function change being more negative for glycerol (3 OH groups) followed by ethylene glycol (2 OH groups) and the remaining alcohols (1 OH group), thus indicating that the number of OH groups present is an important factor in regards to work function changes. For the complete series of adsorbates studied (methanol, ethanol, isopropanol, ethylene glycol, glycerol, hydrogen peroxide and formic acid) there is a linear relationship between the change in the work function and the adsorption energy for the molecular adsorption mode. The relationship is less pronounced for the dissociated adsorption mode for the same series.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    The development of foot ulcers is a common consequence of severe diabetes. Due to vascular disorders and impeded healing caused by the disease, most foot ulcers have been reported to be affected by body weight and progress with time. Also, abnormal distribution of plantar pressures has been observed to cause the formation of additional ulcers, which may collectively lead to traumatic amputations. While a study of such pathophysiology is not possible through experiments, a few computational modelling works have investigated diabetic foot ulcers. To date, ulcers with a few sizes and locations have been studied, and their effect on the plantar stresses has been quantified. In this work, we have attempted to study the effect of all possible ulcer locations on the generated plantar peak stresses and peak stress locations where additional ulcers may form. Also, the effect of ulcer location on the possible ulcer growth was investigated. A full-scale foot model was developed and a total of 52 ulcer locations were simulated separately, with standing and walking loads. The generated stresses were normalised with the foot size and statistically analysed to develop novel formulations for predicting peak plantar stresses and their locations for any known ulcer location. The results from this study are anticipated to provide important guidelines to doctors and medical practitioners for predicting foot ulcer progression in diabetic patients with existing ulcers and allow the administration of timely preventive interventions.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    According to the current perception, symptomatic, presymptomatic and asymptomatic infectious persons can infect the healthy population susceptible to the SARS-CoV-2. More importantly, various reports indicate that the number of asymptomatic cases can be several-fold higher than the reported symptomatic cases. In this article, we take the reported cases in India and various states within the country till September 1, as the specimen to understand the progression of the COVID-19. Employing a modified SEIRD model, we predict the spread of COVID-19 by the symptomatic as well as asymptomatic infectious population. Considering reported infection primarily due to symptomatic, we compare the model predicted results with the available data to estimate the dynamics of the asymptomatically infected population. Our data indicate that in the absence of the asymptomatic infectious population, the number of symptomatic cases would have been much less. Therefore, the current progress of the symptomatic infection can be reduced by quarantining the asymptomatically infectious population via extensive or random testing. This study is motivated strictly toward academic pursuit; this theoretical investigation is not meant for influencing policy decisions or public health practices.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Sci-hub)

       PDF(Pubmed)

公众号