BOLD

BOLD
  • 文章类型: Journal Article
    胎盘功能在胎儿发育中起着至关重要的作用,因为它是将营养和氧气从母亲传递给胎儿的主要界面。磁共振成像(MRI)显着提高了我们对胎盘复杂结构和功能的可视化和理解能力。这篇综述提供了最常见和最新颖的胎盘MRI技术的最新检查。它还将讨论MRI在诊断和监测胎盘功能不全中的临床应用。以及其对胎儿生长受限(FGR)和先天性心脏病(CHD)的影响。使用多参数MRI技术的持续研究旨在开发新的生物标志物,揭示胎盘参数与发病前疾病状态之间的关系。最终有助于更好的孕产妇和胎儿健康结果,这对于更好地指导临床判断至关重要。
    Placental function plays a crucial role in fetal development, as it serves as the primary interface for delivery of nutrients and oxygen from the mother to fetus. Magnetic resonance imaging (MRI) has significantly improved our ability to visualize and understand the placenta\'s complex structure and function. This review provides an up-to-date examination of the most common and novel placental MRI techniques. It will also discuss the clinical applications of MRI in diagnosing and monitoring placental insufficiency, as well as its implications for fetal growth restriction (FGR) and congenital heart disease (CHD). Ongoing research using multi-parametric MRI techniques aims to develop novel biomarkers and uncover the relationships between placental parameters and pre-onset diseased states, ultimately contributing to better maternal and fetal health outcomes, which is essential to better guide clinical judgement.
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  • 文章类型: Journal Article
    为了全面了解人类自发的大脑动力学,体内获取皮层和皮层下区域的内在活动是必要的。这里我们展示了先进的全脑,静息状态功能磁共振成像(rs-fMRI)数据在7特斯拉和1.5mm各向同性体素分辨率下采集。从56名健康成年人(33名女性,年龄19-39岁)在两次15分钟的睁眼清醒休息中。多频带回波平面成像(EPI)协议的高空间分辨率和短回波时间优化了皮质下血氧水平依赖性(BOLD)敏感性,同时进行呼吸和心脏测量可以对生理噪声进行回顾性校正。产生的数据非常适合对皮质下BOLD信号感兴趣的研究人员。功能时间序列与在同一扫描会话期间获取的高分辨率T1加权结构数据(0.75mm各向同性体素)进行了配准。为了适应数据重用,将功能和结构图像格式化为脑成像数据结构(BIDS),并用fMRIPrep进行预处理。
    To achieve a comprehensive understanding of spontaneous brain dynamics in humans, in vivo acquisition of intrinsic activity across both cortical and subcortical regions is necessary. Here we present advanced whole-brain, resting-state functional magnetic resonance imaging (rs-fMRI) data acquired at 7 Tesla with 1.5 mm isotropic voxel resolution. Functional images were obtained from 56 healthy adults (33 females, ages 19-39 years) in two runs of 15 min eyes-open wakeful rest. The high spatial resolution and short echo times of the multiband echo-planar imaging (EPI) protocol optimizes blood oxygen level-dependent (BOLD)-sensitivity for the subcortex while concurrent respiratory and cardiac measures enable retrospective correction of physiological noise, resulting in data that is highly suitable for researchers interested in subcortical BOLD signal. Functional timeseries were coregistered to high-resolution T1-weighted structural data (0.75 mm isotropic voxels) acquired during the same scanning session. To accommodate data reutilization, functional and structural images were formatted to the Brain Imaging Data Structure (BIDS) and preprocessed with fMRIPrep.
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  • 文章类型: Journal Article
    人类的存在和活动深刻地改变了动物的栖息地,使他们面临更大的风险,但也提供了新的机会和资源。在人类世时代,动物有效地驾驭并在风险和收益之间取得平衡的能力对于它们的生存至关重要。红狐狸(Vulpesvulpes),熟练的城市居民,在人类改变的环境中表现出行为可塑性。我们调查了跟踪摄像机检测频率的变化和行为反应(探索性,bold,和恐惧)当暴露于金属箱中时,沿着城市化梯度生活的野生红狐狸最初呈现干净,然后充满人为食物。所有狐狸种群对人为食物来源表现出更高的兴趣和类似的探索性行为反应,无论城市化梯度如何。尽管对探索行为没有影响,更城市化地区的狐狸最初对空箱表现出更高的恐惧,表明人们对新事物的担忧增加。然而,随着时间的推移,这种恐惧逐渐减弱,在食物面前,与城市较少的狐狸相比,城市狐狸表现出的恐惧略有减少。我们的结果突出了狐狸对人文景观的适应性潜力,还强调了沿着城市化梯度生活的人群的恐惧和探索性行为反应的细微差别。
    Human presence and activities have profoundly altered animals\' habitats, exposing them to greater risks but also providing new opportunities and resources. The animals\' capacity to effectively navigate and strike a balance between risks and benefits is crucial for their survival in the Anthropocene era. Red foxes (Vulpes vulpes), adept urban dwellers, exhibit behavioral plasticity in human-altered environments. We investigated variations in detection frequency on trail cameras and the behavioral responses (explorative, bold, and fearful) of wild red foxes living along an urbanization gradient when exposed to a metal bin initially presented clean and then filled with anthropogenic food. All fox populations displayed an increased interest and similar explorative behavioral responses toward the anthropogenic food source, irrespective of the urbanization gradient. Despite no impact on explorative behaviors, foxes in more urbanized areas initially showed heightened fear toward the empty bin, indicating increased apprehension toward novel objects. However, this fear diminished over time, and in the presence of food, urban foxes displayed slightly reduced fear compared with their less urban counterparts. Our results highlight foxes\' potential for adaptability to human landscapes, additionally underscoring the nuanced interplay of fear and explorative behavioral response of populations living along the urbanization gradient.
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  • 文章类型: Journal Article
    不同的肠道微生物群落组成或在群落组成中没有任何明显的差异,可以强调在多代中保持和选择性繁殖的不同动物行为表型。在微生物群-肠-脑轴框架内运行,我们预计选择性繁殖的斑马鱼(Daniorerio)之间的肠道微生物组分布存在差异,以显示大胆和害羞的人格类型。这将突出肠道微生物介导的对宿主行为的影响。为此,我们通过Miseq从大胆和害羞的斑马鱼个体(n=10)的肠道中扩增并测序了16SrRNA基因的片段。我们发现两种行为表型的组内微生物多样性和组间微生物群落组成均无显着差异。有趣的是,虽然没有统计学上的不同,我们确定粗体表型的肠道微生物群落主要由伯克霍德里亚科,微植物科,和丙酸杆菌科。相比之下,害羞的表型主要是贝参草科,Pirelullacaeae,根瘤菌,和Rubinishaeraceae。两种表型之间的肠道微生物群分布没有任何显着差异,这表明在该物种中,可能存在一个稳定的“核心”肠道微生物组,不管行为表型,或者可能,肠道微生物群在调节这种选择宿主行为方面的作用有限。这是第一项研究,以表征肠道微生物群落的斑马鱼的不同先天行为表型(不被认为是生态失调状态),并且不依赖于抗生素或益生菌治疗来诱导行为变化。这些研究对于我们理解肠道微生物群对规范动物行为的调节作用至关重要。
    Different animal behavioral phenotypes maintained and selectively bred over multiple generations may be underscored by dissimilar gut microbial community compositions or not have any significant dissimilarity in community composition. Operating within the microbiota-gut-brain axis framework, we anticipated differences in gut microbiome profiles between zebrafish (Danio rerio) selectively bred to display the bold and shy personality types. This would highlight gut microbe-mediated effects on host behavior. To this end, we amplified and sequenced a fragment of the 16S rRNA gene from the guts of bold and shy zebrafish individuals (n=10) via Miseq. We uncovered no significant difference in within-group microbial diversity nor between-group microbial community composition of the two behavioral phenotypes. Interestingly, though not statistically different, we determined that the gut microbial community of the bold phenotype was dominated by Burkholderiaceae, Micropepsaceae, and Propionibacteriaceae. In contrast, the shy phenotype was dominated by Beijerinckaceae, Pirelullacaeae, Rhizobiales_Incertis_Sedis, and Rubinishaeraceae. The absence of any significant difference in gut microbiota profiles between the two phenotypes would suggest that in this species, there might exist a stable \"core\" gut microbiome, regardless of behavioral phenotypes, and or possibly, a limited role for the gut microbiota in modulating this selected-for host behavior. This is the first study to characterize the gut microbial community of distinct innate behavioral phenotypes of the zebrafish (that are not considered dysbiotic states) and not rely on antibiotic or probiotic treatments to induce changes in behavior. Such studies are crucial to our understanding of the modulating impacts of the gut microbiome on normative animal behavior.
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  • 文章类型: Journal Article
    背景:在治疗慢性威胁肢体缺血的患者时,有关足部组织灌注的信息很重要。本研究旨在测试测量足部灌注时不同磁共振序列的可靠性。
    方法:16名健康志愿者在测试/重测研究中使用6种不同的磁共振序列(BOLD,多回波梯度回波(mGRE),2D和3DpCASL,PASLFAIR,和具有体素内不相干运动(IVIM)的DWI,并对灌注进行定量测量。对于五个序列,测量袖带引起的缺血,然后是过度活跃的反应。将脚的图像分割成血管体,并从五个血管体中提取灌注数据。
    结果:大胆,PASLFAIR,mGRE,与IVIM的DWI在第一次和第二次扫描之间具有较低的平均差异,而2D和3DpCASL的结果差异最大。基于配对t检验,大胆,和FAIR能够区分所有p值低于0.01的血管小体中的灌注和无灌注。对于在所有血管小体中p值高于0.05的2D和3DpCASL,情况并非如此。mGRE无法区分足外侧的灌注和无灌注。
    结论:大胆,mGRE,pASLFAIR,与2D和3DpCASL相比,使用IVIM的DWI似乎给出了更强大的结果。对外周动脉疾病患者的进一步研究应探索在评估组织缺血和血运重建结果时这些序列是否具有临床相关性。
    结论:本研究提供了可用于改善慢性威胁肢体缺血患者的诊断的知识,以探索组织灌注。
    BACKGROUND: Information on tissue perfusion in the foot is important when treating patients with chronic limb-threatening ischemia. This study aims to test the reliability of different magnetic resonance sequences when measuring perfusion in the foot.
    METHODS: Sixteen healthy volunteers had their right foot scanned in a test/retest study with six different magnetic resonance sequences (BOLD, multi-echo gradient echo (mGRE), 2D and 3D pCASL, PASL FAIR, and DWI with intravoxel incoherent motion (IVIM) with quantitative measurements of perfusion. For five sequences, cuff-induced ischemia followed by a hyperactive response was measured. Images of the feet were segmented into angiosomes and perfusion data were extracted from the five angiosomes.
    RESULTS: BOLD, PASL FAIR, mGRE, and DWI with IVIM had low mean differences between the first and second scans, while the results of 2D and 3D pCASL had the highest differences. Based on a paired t-test, BOLD, and FAIR were able to distinguish between perfusion and no perfusion in all angiosomes with p-values below 0.01. This was not the case with 2D and 3D pCASL with p-values above 0.05 in all angiosomes. The mGRE could not distinguish between perfusion and no perfusion in the lateral side of the foot.
    CONCLUSIONS: BOLD, mGRE, pASL FAIR, and DWI with IVIM seem to give more robust results compared to 2D and 3D pCASL. Further studies on patients with peripheral artery disease should explore if the sequences can have clinical relevance when assessing tissue ischemia and results of revascularization.
    CONCLUSIONS: This study provides knowledge that could be used to improve the diagnosis of patient with chronic limb-threatening ischemia to explore tissue perfusion.
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  • 文章类型: Journal Article
    我们报告了在任务期间和静息状态下脊髓白质(WM)内血液氧合水平依赖性(BOLD)MRI信号的可重复模式的可靠检测。先前的功能性MRI研究表明,BOLD信号不仅在大脑的灰质(GM)中而且在大脑WM以及脊髓内的GM中都能强烈检测到。但是脊髓WM中的类似信号却被忽视了。在这项研究中,我们在松鼠猴的脊髓WM中检测到BOLD信号,并研究了它们与上升和下降WM束的位置和功能的关系。使用一般线性模型在脊髓的上升束中检测到触觉感觉刺激引起的BOLD信号变化。功率谱分析证实,在上升通道中,对周期性刺激的响应在基频处的振幅明显高于下降通道。静息状态信号的独立分量分析确定了来自八个WM集线器的相干波动,这些集线器与主要WM束的已知解剖位置紧密对应。静息状态分析表明,WM集线器以可重复的模式在脊髓节段上表现出相关的信号波动,这与脊髓中WM束的已知神经生物学功能非常吻合。总的来说,这些发现为椎管内WM束的功能组织提供了证据,并证实它们在基线和刺激条件下产生与GM相似的血液动力学反应.
    We report the reliable detection of reproducible patterns of blood-oxygenation-level-dependent (BOLD) MRI signals within the white matter (WM) of the spinal cord during a task and in a resting state. Previous functional MRI studies have shown that BOLD signals are robustly detectable not only in gray matter (GM) in the brain but also in cerebral WM as well as the GM within the spinal cord, but similar signals in WM of the spinal cord have been overlooked. In this study, we detected BOLD signals in the WM of the spinal cord in squirrel monkeys and studied their relationships with the locations and functions of ascending and descending WM tracts. Tactile sensory stimulus -evoked BOLD signal changes were detected in the ascending tracts of the spinal cord using a general-linear model. Power spectral analysis confirmed that the amplitude at the fundamental frequency of the response to a periodic stimulus was significantly higher in the ascending tracts than the descending ones. Independent component analysis of resting-state signals identified coherent fluctuations from eight WM hubs which correspond closely to the known anatomical locations of the major WM tracts. Resting-state analyses showed that the WM hubs exhibited correlated signal fluctuations across spinal cord segments in reproducible patterns that correspond well with the known neurobiological functions of WM tracts in the spinal cord. Overall, these findings provide evidence of a functional organization of intraspinal WM tracts and confirm that they produce hemodynamic responses similar to GM both at baseline and under stimulus conditions.
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  • 文章类型: Journal Article
    在同时采集肌肉BOLD/EMG期间,MR诱导的梯度伪影会影响EMG记录。然而,没有专用的硬件可以很容易地去除梯度伪影,和替代方法是昂贵和耗时的。这项研究旨在开发三种需要不同处理级别和MR兼容硬件的去噪方法。在两个时间点,从6名参与者的小腿记录表面肌电图(50:50的性别比例,年龄=26.24.6岁。,高度=173.59.2厘米,重量=71.511.4kg)采用基于足底屈曲的块设计,包括30秒的休息,然后30秒的屈曲5分钟,在三种情况下:在MRI孔内,有和没有BOLD序列(3T,BOLD序列,GREEPI,10片,6464矩阵,2mm厚度,和TE/TR/翻转=35/3000ms/70),在核磁共振成像环境之外。同时BOLD/EMG记录使用平均伪影减法和三种伪影模板创建方法进行去噪,每个都有不同的时序和硬件要求。方法M1通过记录来自MRI的扫描仪触发来构建伪影模板;M2创建具有计算为TR/[切片数量]的恒定伪影周期的伪影模板;M3通过观察位于EMG记录中的梯度伪影的周期性来估计伪影模板。在后处理之后,进行了SNR分析,比较休息到屈曲期,评估去噪方法的有效性,并比较条件之间的差异。线性混合效应模型显示,去噪方法之间的平均SNR没有显着差异(p=0.656)。此外,EMGSNR测量值受磁环境的显著影响(p<0.05),但随时间的推移不受肌肉疲劳的影响(p=0.975)。同时BOLD/EMG过程中被梯度伪影污染的EMG记录可以使用所有提出的方法进行有效的去噪。有两种方法不需要额外的硬件。用最少的后处理,在肌肉BOLDMRI研究期间可以很容易地进行EMG。
    The MR-induced gradient artifact affects EMG recordings during simultaneous muscle BOLD/EMG acquisitions. However, no dedicated hardware can remove the gradient artifact easily, and alternative methods are expensive and time-consuming. This study aimed to develop three denoising methods requiring different processing levels and MR-compatible hardware. At two time points, surface EMG was recorded from the lower leg of 6 participants (50:50 sex ratio, age = 26.24.6 yrs., height = 173.59.2 cm, weight = 71.511.4 kg) using a plantar flexion-based block design consisting of 30s of rest followed by 30s of flexion for 5 min, under three conditions: inside the MRI bore, with and without a BOLD sequence (3 T, BOLD sequence, GRE EPI, 10 slices, 64×64 matrix, 2 mm thickness, and TE/TR/flip = 35/3000 ms/70), and outside the MRI environment. Simultaneous BOLD/EMG recordings were denoised using average artifact subtraction with three methods of artifact template creation, each having varying timing and hardware requirements. Method M1 builds the artifact template by recording the scanner triggers coming from the MRI; M2 creates the artifact template with a constant artifact period computed as TR/[number of slices]; M3 estimates the artifact template by looking at the periodicity of the gradient artifact located in the EMG recordings. Following postprocessing, SNR analysis was performed, comparing rest-to-flexion periods, to assess the efficacy of denoising methods and to compare differences between conditions. Linear mixed-effects models showed no significant differences in the mean SNR between denoising methods (p = 0.656). Furthermore, EMG SNR measurements were significantly affected by the magnetic environment (p < 0.05) but not by muscle fatigue over time (p = 0.975). EMG recordings contaminated with gradient artifacts during simultaneous BOLD/EMG can be efficiently denoised using all proposed methods, with two methods requiring no extra hardware. With minimal post-processing, EMG can easily be performed during muscle BOLD MRI studies.
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  • 文章类型: Journal Article
    本章介绍了使用DNA序列数据获取和比较使用公共数据库GenBank和BarcodeofLifeDataSystem(BOLD)进行分类鉴定的程序。本章首先描述了用于准备上传到GenBank和BOLD的质量序列的程序。接下来,使用GenBankBLAST和BOLD识别引擎描述了用于针对公共数据库查询DNA序列的步骤。提出了分类识别分配的解释指南。最后,提供了用于评估来自GenBank和BOLD的序列的准确性和可靠性的程序。
    This chapter describes procedures for the use of DNA sequence data to obtain and compare taxonomic identification using the public databases GenBank and Barcode of Life Data System (BOLD). The chapter begins by describing procedures used to prepare quality sequences for uploading into GenBank and BOLD. Next, steps used to query the DNA sequences against the public databases are described using GenBank BLAST and BOLD identification engines. Interpretation guidelines for the taxonomic identification assignments are presented. Finally, a procedure for evaluating the accuracy and reliability of sequences from GenBank and BOLD is provided.
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  • 文章类型: Journal Article
    DNA条形码很短,遗传学家可以用来识别所有活的分类单元的标准化DNA片段。另一方面,DNA条形码通过针对DNA条形码参考文库分析这些特定区域来鉴定物种。在最初的几年里,通过Sanger方法测序的DNA条形码被分类学家广泛用于物种的表征和鉴定。但近年来,下一代测序(NGS)的DNA条形码已发现更广泛的应用,如质量控制,受保护物种的生物监测,和生物多样性评估。技术进步也为元编码铺平了道路,这使得大量的平行序列成为可能。使用高通量测序技术对复杂批量样品进行测序。在未来,参考可用的序列数据,DNA条形码以及高通量技术将在分类学分类方面显示出惊人的进步。
    DNA barcodes are short, standardized DNA segments that geneticists can use to identify all living taxa. On the other hand, DNA barcoding identifies species by analyzing these specific regions against a DNA barcode reference library. In its initial years, DNA barcodes sequenced by Sanger\'s method were extensively used by taxonomists for the characterization and identification of species. But in recent years, DNA barcoding by next-generation sequencing (NGS) has found broader applications, such as quality control, biomonitoring of protected species, and biodiversity assessment. Technological advancements have also paved the way to metabarcoding, which has enabled massive parallel sequ.encing of complex bulk samples using high-throughput sequencing techniques. In future, DNA barcoding along with high-throughput techniques will show stupendous progress in taxonomic classification with reference to available sequence data.
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  • 文章类型: Journal Article
    背景:Catfish(Siluriformes目)是世界上最多样化和分布最广泛的鱼群之一。它们不仅用于人类消费,也是观赏鱼贸易的重要组成部分。作为生物多样性热点,印度的东北地区拥有各种各样的观赏鱼。Catfish包含大量的物种;在这项研究中,作者试图使用DNA条形码阐明在印度东北部发现的一些重要的观赏cat鱼的系统发育关系。
    结果:在这项研究中,我们试图使用DNA条形码探索13种(41个标本)的观赏鱼的系统发育史,这些观赏鱼跨越12个属和9个家族。使用Kimura2参数(K2P)在特异性内和特异性间水平计算成对遗传距离。构建了一个邻居连接树,以了解9个不同cat鱼科之间的系统发育关系。本研究中的所有标本都与各自的物种聚集在同一家族中,并形成了三个子进化枝。然而,Olyralongicaudata,属于Bagridae家族,没有与同一家族的其他物种聚集。在这项研究中,作者建议将O.longicaudata的分类修改为其原始家族,橄榄科。
    结论:在这项研究中,在物种之间观察到最大种内遗传距离为0.03,最小种间遗传距离为0.14。因此,很明显,物种之间存在条形码间隙,这有助于正确识别物种。因此,DNA条形码有助于补充物候方法,并且还揭示了属于Bagridae家族的cat鱼之间的系统发育关系。
    BACKGROUND: Catfishes (order Siluriformes) are among the most diverse and widely distributed fish groups in the world. They are not only used for human consumption but are also a major part of the ornamental fish trade. Being a Biodiversity Hotspot, the North Eastern Region of India is home to a diverse population of ornamental fishes. Catfishes contain a humongous number of species; in this study, the authors have tried to elucidate the phylogenetic relationship of some important ornamental catfishes found in North East India using DNA barcodes.
    RESULTS: In this study, we have tried to explore the phylogenetic history of 13 species (41 specimens) of ornamental catfishes spanning 12 genera and 9 families of Siluriformes using DNA barcoding. Pairwise genetic distances using Kimura 2-Parameter (K2P) were calculated at intra-specific and inter-specific levels. A Neighbor-Joining tree was constructed to understand the phylogenetic relationship among the nine different catfish families. All the specimens under this study clustered with their respective species under the same family and formed three sub-clades. However, Olyra longicaudata, belonging to the Bagridae family, did not cluster with other species from the same family. In this study, the authors have suggested a revision of the classification of O. longicaudata back to its original family, Olyridae.
    CONCLUSIONS: In this study, the maximum intraspecific genetic distance of 0.03 and the minimum interspecific genetic distance of 0.14 were observed among the species. Therefore, it is evident that there is a barcoding gap among the species, which helped in the correct identification of the species. Thus, DNA barcoding helped complement the phenetic approach and also revealed a different phylogenetic relationship among the catfishes belonging to the Bagridae family.
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