normalization

归一化
  • 文章类型: Journal Article
    脑部医学图像分割是医学图像处理中的一项关键任务,在中风等疾病的预测和诊断中发挥着重要作用,老年痴呆症,和脑肿瘤。然而,由于不同扫描仪之间的站点间差异很大,因此不同来源的数据集之间的分布差异很大,成像协议,和人口。这导致实际应用中的跨域问题。近年来,已经进行了许多研究来解决大脑图像分割中的跨域问题。
    本评论遵循系统评论和荟萃分析(PRISMA)的首选报告项目的标准,用于数据处理和分析。我们从PubMed检索了相关论文,WebofScience,和IEEE数据库从2018年1月到2023年12月,提取有关医疗领域的信息,成像模式,解决跨域问题的方法,实验设计,和来自选定论文的数据集。此外,我们比较了中风病变分割方法的性能,脑白质分割和脑肿瘤分割。
    本综述共纳入并分析了71项研究。解决跨域问题的方法包括迁移学习,规范化,无监督学习,变压器型号,和卷积神经网络(CNN)。在ATLAS数据集上,领域自适应方法显示,与非自适应方法相比,卒中病变分割任务总体改善约3%.然而,鉴于当前研究中基于MICCAI2017中白质分割任务的方法和BraTS中脑肿瘤分割任务的方法的数据集和实验方法的多样性,直观地比较这些方法的优缺点是具有挑战性的。
    尽管已经应用了各种技术来解决大脑图像分割中的跨域问题,目前缺乏统一的数据集和实验标准。例如,许多研究仍然基于n折交叉验证,而直接基于跨站点或数据集的交叉验证的方法相对较少。此外,由于大脑分割领域的医学图像类型多种多样,对性能进行简单直观的比较并不容易。这些挑战需要在未来的研究中解决。
    UNASSIGNED: Brain medical image segmentation is a critical task in medical image processing, playing a significant role in the prediction and diagnosis of diseases such as stroke, Alzheimer\'s disease, and brain tumors. However, substantial distribution discrepancies among datasets from different sources arise due to the large inter-site discrepancy among different scanners, imaging protocols, and populations. This leads to cross-domain problems in practical applications. In recent years, numerous studies have been conducted to address the cross-domain problem in brain image segmentation.
    UNASSIGNED: This review adheres to the standards of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for data processing and analysis. We retrieved relevant papers from PubMed, Web of Science, and IEEE databases from January 2018 to December 2023, extracting information about the medical domain, imaging modalities, methods for addressing cross-domain issues, experimental designs, and datasets from the selected papers. Moreover, we compared the performance of methods in stroke lesion segmentation, white matter segmentation and brain tumor segmentation.
    UNASSIGNED: A total of 71 studies were included and analyzed in this review. The methods for tackling the cross-domain problem include Transfer Learning, Normalization, Unsupervised Learning, Transformer models, and Convolutional Neural Networks (CNNs). On the ATLAS dataset, domain-adaptive methods showed an overall improvement of ~3 percent in stroke lesion segmentation tasks compared to non-adaptive methods. However, given the diversity of datasets and experimental methodologies in current studies based on the methods for white matter segmentation tasks in MICCAI 2017 and those for brain tumor segmentation tasks in BraTS, it is challenging to intuitively compare the strengths and weaknesses of these methods.
    UNASSIGNED: Although various techniques have been applied to address the cross-domain problem in brain image segmentation, there is currently a lack of unified dataset collections and experimental standards. For instance, many studies are still based on n-fold cross-validation, while methods directly based on cross-validation across sites or datasets are relatively scarce. Furthermore, due to the diverse types of medical images in the field of brain segmentation, it is not straightforward to make simple and intuitive comparisons of performance. These challenges need to be addressed in future research.
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  • 文章类型: Journal Article
    科学和社会通常会对痛经或痛性月经来潮做出反应,自然,和月经不可避免的部分。这种正常化极大地促进了痛苦的月经来潮的系统性消除。耻辱,保密,以及“应对”的期望推动了月经疼痛的正常化。在这篇文章中,我认为,月经疼痛的正常化限制了以一种否则会引起警报或担忧的方式分享痛苦的月经疼痛的能力。这会导致临床医生降低月经疼痛,甚至来月经的人降低自己的痛苦。我指的是将月经疼痛作为与疼痛相关的动机缺陷的一个例子。与疼痛相关的动机缺陷描述了由于社会实践和思想而使话语无法激励的情况,这些实践和思想使人们很难认识到共享的具体经验的重要性。
    “只是”一个痛苦的时期:为什么我们不担心月经疼痛的报道人们普遍认为,痛苦的月经来潮只是月经周期的正常部分;所有月经来潮的人都应该处理的事情。在时期周围也存在污名,并期望将时期的经验隐藏起来。这将创建一个称为标准化的过程。因为疼痛的月经来潮是正常的,对报告疼痛性月经来潮的患者更容易解雇。在这篇文章中,我认为,疼痛的月经来潮是正常的,这使得其他人很难被月经疼痛的报告所关注或惊慌。月经疼痛的报告被降级或被认为不是那么糟糕。当我们无法看到疼痛有多严重,因为社会认为报告的疼痛是正常的,疼痛报告未能引起听众的关注。我称这个过程为与疼痛相关的动机缺陷。
    Science and society typically respond to dysmenorrhea-or painful menstrual cramps-as a normal, natural, and inevitable part of menstruation. This normalization has greatly contributed to the systemic dismissal of painful menstrual cramps. Stigma, secrecy, and the expectation to \"cope\" fuel the normalization of menstrual pain. In this article, I argue that the normalization of menstrual pain restricts the ability to share an excruciating menstrual pain in a way that would otherwise elicit alarm or concern. This can cause clinicians to downgrade menstrual pain, and even menstruating persons to downgrade their own pain. I refer to the dismissal of menstrual pain as an example of a pain-related motivational deficit. A pain-related motivational deficit describes instances in which an utterance fails to motivate due to societal practices and ideas that make it difficult to recognize the import of the embodied experience being shared.
    “Just” a painful period: why we are not concerned by reported menstrual painIt is widely believed that painful menstrual cramps are just a normal part of the menstrual cycle; something that all menstruating persons are expected to deal with. There is also a stigma around periods and an expectation to keep the experience of periods hidden. This creates a process known as normalization. Because painful menstrual cramps are normalized, it is easier to dismiss patients who report painful menstrual cramps. In this article, I argue that the idea that painful menstrual cramps are normal makes it difficult for others to be concerned or alarmed by reports of menstrual pain. Reports of menstrual pain are downgraded or are seen as not that bad. When we are unable to see how bad a pain is because society believes the reported pain is normal, the pain report fails to elicit concern from the listener. I call this process a pain-related motivational deficit.
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  • 文章类型: Journal Article
    背景:下丘脑-垂体-甲状腺轴的初步评估是通过测量血清游离甲状腺素(fT4)和促甲状腺激素浓度来完成的。为了正确解释这些测量,可靠的年龄特异性参考区间(RI)是基础。由于符合临床和实验室标准研究所指南的新生儿fT4RI不适用于所有测定,我们着手创建基于文献的统一年龄特异性新生儿fT4RIs,可用于每项检测.方法:对于个体参与者fT4浓度的荟萃分析,我们系统地搜索了MEDLINE和Embase(搜索日期2023年12月6日;PROSPERO注册CRD42016041871)。我们搜索了报告2-27天健康足月新生儿fT4浓度的研究,在碘充足的地区,没有甲状腺疾病的母亲所生。作者被邀请提供数据。由于测定之间的标准化差异,数据不能直接组合进行荟萃分析,我们尝试使用两种不同的方法对数据进行归一化。结果:我们从20项研究中获得了4206fT4浓度,这些研究使用了来自6家制造商的13种不同的测定法。首先,我们着手使用(测定特异性)成人RI的平均值和标准偏差对fT4数据进行归一化.fT4浓度转化为Z值,假设正态分布。使用线性混合效应模型(LMM),我们仍然发现不同研究的fT4浓度之间存在显著差异(p<0.001),在这种正常化之后。作为第二种方法,我们使用方法/试验比较研究的数据对fT4浓度进行了归一化.我们使用Cobas测定和其他测定之间的关系作为参考点以将所有值转换为Cobas值。然而,这种方法也未能产生一致的结果,归一化数据之间存在显著差异(LMMp<0.001)。结论:我们得出结论,我们对fT4测定结果归一化的尝试是不成功的。与我们的不成功分析相关的混淆因素可能是测定相关的和/或生物学的。这些发现对患者护理具有重要意义,因为依赖文献中的RI可能会导致对结果的错误解释。因此,我们强烈建议建立局部RI,以准确解释新生儿血清fT4浓度.
    Background: Initial evaluation of the hypothalamus-pituitary-thyroid axis is done by measuring serum free thyroxine (fT4) and thyrotropin concentrations. For correct interpretation of these measurements, reliable age-specific reference intervals (RIs) are fundamental. Since neonatal fT4 RIs conforming to the Clinical and Laboratory Standards Institute guidelines are not available for all assays, we set out to create literature-based uniform age-specific neonatal fT4 RIs that may be used for every assay. Methods: For meta-analysis of individual participant fT4 concentrations, we systematically searched MEDLINE and Embase (search date December 6, 2023; PROSPERO registration CRD42016041871). We searched for studies reporting fT4 concentrations in healthy term newborns aged 2-27 days, born to mothers without thyroid disease in iodine-sufficient regions. Authors were invited to supply data. Due to standardization differences between assays, data could not be combined for meta-analysis directly, and we attempted to normalize the data using two distinct methods. Results: We obtained 4206 fT4 concentrations from 20 studies that used 13 different assays from 6 manufacturers. First, we set out to normalize fT4 data using the mean and standard deviation of (assay-specific) adult RIs. fT4 concentrations were transformed into Z-scores, assuming a normal distribution. Using a linear mixed-effects model (LMM), we still found a significant difference between fT4 concentration across studies (p < 0.001), after this normalization. As a second approach, we normalized the fT4 concentrations using data from a method/assay comparison study. We used the relationship between the Cobas assay and the other assays as a reference point to convert all values to Cobas values. However, this method also failed to produce consistent results, with significant differences between the normalized data (LMM p < 0.001). Conclusions: We conclude that our attempts at normalizing fT4 assay results were unsuccessful. Confounders related to our unsuccessful analysis may be assay related and/or biological. These findings have significant implications for patient care, since relying on RIs from literature may result in erroneous interpretation of results. Therefore, we strongly recommend to establish local RIs for accurate interpretation of serum fT4 concentrations in neonates.
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  • 文章类型: Journal Article
    局部晚期口腔癌的治疗需要多学科护理,包括手术,放射治疗,和化疗,根据疾病的阶段而有所不同,现场参与,和手术通道。口腔癌通常具有增加的复发率和远处转移扩散的可能性。5年后死亡率为50%,预后较差。口服节拍化疗由于其易于给药,旨在实现更高的患者依从性,较低的剂量,与铂类药物的常规IV方案相比,副作用更小。在这次审查中,我们总结了相关文献,以使读者了解节拍疗法在口腔癌治疗中的潜在应用。
    Treatment of locally advanced oral cancer requires multidisciplinary care, including surgery, radiotherapy, and chemotherapy, which varies based on the stage of the disease, site of involvement, and surgical access. Oral cancer usually presents with an increased recurrence rate and potential for distant metastatic spread. It confers a poor prognosis with a 50% mortality rate after five years. Oral metronomic chemotherapy aims to achieve higher patient compliance due to its ease of administration, lower dosage, and lesser side effects than conventional IV regimens of platinum-based drugs. In this review, we have summarized the relevant literature to benefit the readers regarding the potential application of metronomic therapy in the management of oral cancer.
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  • 文章类型: Journal Article
    由于其对健康的深远影响,人类微生物组是一个新兴的研究前沿。高通量微生物组测序能够研究微生物群落,但面临分析挑战。特别是,缺乏专门的预处理方法来提高数据质量阻碍了在下游分析之前有效地最小化偏差。这篇综述旨在通过提供与微生物组研究相关的预处理技术的全面概述来解决这一差距。我们概述了微生物组数据分析的典型工作流程。讨论的预处理方法包括质量过滤,批量效应校正,缺失值的填补,归一化,和数据转换。我们强调每种技术的优势和局限性,作为研究人员的实用指南,并确定需要进一步发展方法学的领域。建立稳健,标准化的预处理对于从微生物组研究中得出有效的生物学结论至关重要。
    The human microbiome is an emerging research frontier due to its profound impacts on health. High-throughput microbiome sequencing enables studying microbial communities but suffers from analytical challenges. In particular, the lack of dedicated preprocessing methods to improve data quality impedes effective minimization of biases prior to downstream analysis. This review aims to address this gap by providing a comprehensive overview of preprocessing techniques relevant to microbiome research. We outline a typical workflow for microbiome data analysis. Preprocessing methods discussed include quality filtering, batch effect correction, imputation of missing values, normalization, and data transformation. We highlight strengths and limitations of each technique to serve as a practical guide for researchers and identify areas needing further methodological development. Establishing robust, standardized preprocessing will be essential for drawing valid biological conclusions from microbiome studies.
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  • 文章类型: Journal Article
    目标:应用于医学图像分析的人工智能已被广泛用于开发非侵入性诊断和预后特征。然而,这些成像生物标志物应在多中心数据集上进行大量验证,以证明其稳健性,然后才能引入临床实践.主要的挑战是由巨大的和不可避免的图像可变性,通常使用不同的预处理技术,包括空间,强度和特征归一化。这项研究的目的是系统地总结归一化方法,并通过荟萃分析评估它们与影像组学模型性能的相关性。这项审查是根据PRISMA声明进行的:收集了4777篇论文,但只包括了74个。根据两个临床目的进行了两个荟萃分析:反应的表征和预测。这篇综述的结果表明,有一些常用的归一化方法,但不是一个普遍同意的管道,可以提高性能,弥合长凳和床边之间的差距。
    Goal: Artificial intelligence applied to medical image analysis has been extensively used to develop non-invasive diagnostic and prognostic signatures. However, these imaging biomarkers should be largely validated on multi-center datasets to prove their robustness before they can be introduced into clinical practice. The main challenge is represented by the great and unavoidable image variability which is usually addressed using different pre-processing techniques including spatial, intensity and feature normalization. The purpose of this study is to systematically summarize normalization methods and to evaluate their correlation with the radiomics model performances through meta-analyses. This review is carried out according to the PRISMA statement: 4777 papers were collected, but only 74 were included. Two meta-analyses were carried out according to two clinical aims: characterization and prediction of response. Findings of this review demonstrated that there are some commonly used normalization approaches, but not a commonly agreed pipeline that can allow to improve performance and to bridge the gap between bench and bedside.
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  • 文章类型: Journal Article
    分析化学领域已显著进步的国家的最先进的仪器的可用性,允许在这一领域的新应用的发展。然而,在许多情况下,对记录数据的直接解释通常并不简单,因此需要一定程度的预处理(例如,基线校正,衍生工具,归一化,平滑)。这些技术已成为成功分析记录数据的关键第一步,并建议在应用化学计量学之前使用它们(例如,分类,校准开发)。本文的目的是概述应用于仪器分析方法的最常用的预处理方法(例如,光谱学,层析)。还将讨论它们在近红外和UV-VIS光谱以及气相色谱中的应用实例。总的来说,本文提供了对分析化学预处理技术的全面了解,在数据分析和解释过程中强调它们的重要性,以及在准确和可靠的化学计量模型的发展。
    The field of analytical chemistry has been significantly advanced by the availability of state-of-the-art instrumentation, allowing for the development of novel applications in this field. However, in many cases, the direct interpretation of the recorded data is often not straightforward, hence some level of pre-processing is required (e.g., baseline correction, derivatives, normalization, smoothing). These techniques have become a critical first step for the successful analysis of the data recorded, and it is recommended to use them before the application of chemometrics (e.g., classification, calibration development). The aim of this paper is to provide with an overview of the most used pre-processing methods applied to instrumental analytical methods (e.g., spectroscopy, chromatography). Examples of their application in near infrared and UV-VIS spectroscopy as well as in gas chromatography will be also discussed. Overall, this paper provides with a comprehensive understanding of pre-processing techniques in analytical chemistry, highlighting their importance during the analysis and interpretation of data, as well as during the development of accurate and reliable chemometric models.
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  • 文章类型: Journal Article
    BACKGROUND: As laws change and cannabis use increases, it is worthwhile to take a rich account of cannabis stigmas in society, and this review identifies a disjunction between quantitative investigations on cannabis users and qualitative investigations on the same population. This is also the first attempt to explicate cannabis stigmas as they manifest on multiple analytical levels. Following brief explanations of the normalization hypothesis and the concept of stigma, this review is organized between structural (macro) stigmas, social (meso) stigmas, and personal (micro) stigmas. Furthermore, since cannabis stigmas are similar to the stigmas faced by sexual minorities in that each is physically concealable, the two groups are compared here because the literature base is more extensive with the latter.
    METHODS: This qualitative review synthesizes the body of empirical studies on both medical and nonmedical cannabis use with attention to stigma, stereotypes, and other social consequences. Studies considered for the review mostly come from the social sciences, particularly sociology. The information presented here is primarily drawn from peer-reviewed articles on cannabis users in the USA, though research from similar national contexts is cited as well.
    RESULTS: This review suggests claims of normalization may be premature. While stigmas surrounding cannabis appear to have diminished, there is little evidence that such stigmas have entirely disappeared. It is possible that sweeping claims of cannabis normalization may be symptomatic of unchecked social privileges or social distance from cannabis users. Such claims may also be the product of valuing quantitative data over the nuanced accounts uncovered through qualitative investigations.
    CONCLUSIONS: This substantial coverage of the literature indicates the lived experience of a post-prohibition society is not the same as a one where cannabis is normalized. Individuals working with those who use cannabis should not assume stigmas have disappeared, especially since cannabis stigmas often intersect with other sources of social inequality. While a comprehensive discussion of ways to combat lingering social stigmas is beyond the scope of this review, it concludes by highlighting some of the strategies identified through research which help users resist or mitigate these oppressive forces. Future research would be wise to prioritize the experiences of people of color, women, and adult populations if the hope is to identify ways to further normalize the plant in American society.
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  • 文章类型: Journal Article
    Dozens of normalization methods for correcting experimental variation and bias in high-throughput expression data have been developed during the last two decades. Up to 23 methods among them consider the skewness of expression data between sample states, which are even more than the conventional methods, such as loess and quantile. From the perspective of reference selection, we classified the normalization methods for skewed expression data into three categories, data-driven reference, foreign reference, and entire gene set. We separately introduced and summarized these normalization methods designed for gene expression data with global shift between compared conditions, including both microarray and RNA-seq, based on the reference selection strategies. To our best knowledge, this is the most comprehensive review of available preprocessing algorithms for the unbalanced transcriptome data. The anatomy and summarization of these methods shed light on the understanding and appropriate application of preprocessing methods.
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  • 文章类型: Journal Article
    The heterogeneity among previous studies of future mortality projections due to climate change has often hindered comparisons and syntheses of resulting impacts. To address this challenge, the present study introduced a novel method to normalize the results from projection studies according to different baseline and projection periods and climate scenarios, thereby facilitating comparison and synthesis. This study reviewed the 15 previous studies involving projected climate change-related mortality under Representative Concentration Pathways. To synthesize their results, we first reviewed the important study design elements that affected the reported results in previous studies. Then, we normalized the reported results by CO2 concentration in order to eliminate the effects of the baseline period, projection period, and climate scenario choices. For twenty-five locations worldwide, the normalized percentage changes in temperature-attributable mortality per 100 ppm increase in global CO2 concentrations ranged between 41.9% and 330%, whereas those of total mortality ranged between 0.3% and 4.8%. The normalization methods presented in this work will guide future studies to provide their results in a normalized format and facilitate research synthesis to reinforce our understanding on the risk of climate change.
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