gating

门控
  • 文章类型: Journal Article
    迄今为止,仅通过模拟以及点和平面剂量测量来研究帧内运动和变形对临床放射治疗的影响。这项研究的目的是将拟人化3D剂量学与可变形的腹部体模相结合,以测量光子放射疗法中分数内运动和门控的影响,并评估其在质子治疗中的适用性。
    对腹部体模进行了修改,以容纳形状为人类肝脏的可变形拟人化3D剂量计。在不使用呼吸门控或呼吸门控的情况下,将肝脏特异性光子放射疗法和质子笔形束扫描治疗计划传递到体模,而没有运动以及具有12mm正弦运动。
    使用固定辐照作为参考,计划目标体积(PTV)中运动实验的局部3%/2mm3D伽马指数通过率高于97%(光子)和78%(质子)具有门控,而低于74%(光子)和45%(质子)没有门控。
    首次将嵌入可变形腹部体模中的高分辨率可变形拟人化3D剂量计用于对表现出呼吸运动的目标进行光子和质子治疗的实验验证。实验表明,门控可以改善光子放射治疗和质子治疗的剂量覆盖率和几何精度。
    UNASSIGNED: The impact of intrafractional motion and deformations on clinical radiotherapy delivery has so far only been investigated by simulations as well as point and planar dose measurements. The aim of this study was to combine anthropomorphic 3D dosimetry with a deformable abdominal phantom to measure the influence of intra-fractional motion and gating in photon radiotherapy and evaluate the applicability in proton therapy.
    UNASSIGNED: An abdominal phantom was modified to hold a deformable anthropomorphic 3D dosimeter shaped as a human liver. A liver-specific photon radiotherapy and a proton pencil beam scanning therapy plan were delivered to the phantom without motion as well as with 12 mm sinusoidal motion while using either no respiratory gating or respiratory gating.
    UNASSIGNED: Using the stationary irradiation as reference the local 3 %/2 mm 3D gamma index pass rate of the motion experiments in the planning target volume (PTV) was above 97 % (photon) and 78 % (proton) with gating whereas it was below 74 % (photon) and 45 % (proton) without gating.
    UNASSIGNED: For the first time a high-resolution deformable anthropomorphic 3D dosimeter embedded in a deformable abdominal phantom was applied for experimental validation of both photon and proton treatments of targets exhibiting respiratory motion. It was experimentally shown that gating improves dose coverage and the geometrical accuracy for both photon radiotherapy and proton therapy.
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  • 文章类型: Letter
    暂无摘要。
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  • 文章类型: Journal Article
    为了更好的解决食品安全问题,开发一种快速、灵敏的食品污染残留物检测技术非常重要。有机光电化学晶体管(OPECT)生物传感器依靠半导体在光激发时产生的光电压来调节聚合物通道的电导率并在零栅极偏压下实现生物传感器分析。该技术集成了光电化学(PEC)生物分析的优异特性以及有机电化学晶体管(OECT)的高灵敏度和固有放大能力。基于此,OPECT生物传感器检测已被证明优于传统的生物传感器检测方法。在这次审查中,综述了OPECT生物传感器在疾病标志物和食品残留分析中的研究现状,基本原则,分类,简要介绍了OPECT生物传感器分析的生物传感机理,并根据信号策略讨论了生物传感器分析的最新应用。主要介绍了OPECT生物传感器分析方法在不同领域的应用,包括检测疾病标志物和食物危害残留物,如前列腺特异性抗原,心脏型脂肪酸结合蛋白,牛奶样品中的T-2毒素检测,脂肪量和客观性相关蛋白质,牛奶中的环丙沙星。OPECT生物传感器为许多领域的安全分析和检测平台的建设提供了巨大的发展潜力,比如农业和食品,希望为今后发展选择性较高的生物传感分析方法提供一定的参考,更快的分析速度和更高的灵敏度。
    In order to solve the food safety problem better, it is very important to develop a rapid and sensitive technology for detecting food contamination residues. Organic photoelectrochemical transistor (OPECT) biosensor rely on the photovoltage generated by a semiconductor upon excitation by light to regulate the conductivity of the polymer channels and realize biosensor analysis under zero gate bias. This technology integrates the excellent characteristics of photoelectrochemical (PEC) bioanalysis and the high sensitivity and inherent amplification ability of organic electrochemical transistor (OECT). Based on this, OPECT biosensor detection has been proven to be superior to traditional biosensor detection methods. In this review, we summarize the research status of OPECT biosensor in disease markers and food residue analysis, the basic principle, classification, and biosensing mechanism of OPECT biosensor analysis are briefly introduced, and the recent applications of biosensor analysis are discussed according to the signal strategy. We mainly introduced the OPECT biosensor analysis methods applied in different fields, including the detection of disease markers and food hazard residues such as prostate-specific antigen, heart-type fatty acid binding protein, T-2 toxin detection in milk samples, fat mass and objectivity related protein, ciprofloxacin in milk. The OPECT biosensor provides considerable development potential for the construction of safety analysis and detection platforms in many fields, such as agriculture and food, and hopes to provide some reference for the future development of biosensing analysis methods with higher selectivity, faster analysis speed and higher sensitivity.
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  • 文章类型: Journal Article
    脂肪细胞表征和使用流式细胞术评估膜蛋白已被证明是具有挑战性的,因为脂肪细胞是脆弱的,特别是在高BMI的受试者中。我们克服了这些挑战,通过减少中间步骤来优化组织消化时间,以最大程度地减少脂肪细胞的摩擦和破裂。我们避免了对专门仪器配置的要求,并使用了改进的门控策略来防止在分析过程中包含脂滴。高达90%的细胞群在门控区域中可用。我们检查了ABCA1的表达水平,ABCA1是一种重申脂肪细胞选择的膜蛋白。总之,该方案需要较少的组织样本,提高可行性和成本效率.因此,我们的流式细胞术方法是研究脂肪细胞膜特征的改进。
    Adipocyte characterization and assessing membrane proteins using flow cytometry has been proven to be challenging as adipocytes are fragile, especially in subjects with high BMI. We overcame these challenges through a protocol optimizing tissue digestion time by reducing intermediate steps to minimize adipocyte friction and breakage. We avoided requirement for specialized instrument configuration and used a modified gating strategy to prevent inclusion of lipid droplets during analysis. Up to 90% of the cell population were available in the gating area. We checked the expression level of ABCA1, a membrane protein reaffirming adipocyte selection. In summary, this protocol requires lesser tissue sample improving feasibility and cost efficiency. Thus, our flow cytometry method is an improvement for studying adipocyte membrane characteristics.
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  • 文章类型: Journal Article
    目的:流式细胞术是一种广泛使用的技术,用于识别患者来源的液体中的细胞群,如外周血(PB)或脑脊液(CSF)。尽管它在研究和临床实践中无处不在,门控的过程,即,手动识别细胞类型,是劳动密集型和容易出错的。本研究的目的是通过引入GateNet来解决这一挑战,一种神经网络架构,专为完全端到端自动门控而设计,无需校正批次效应。
    方法:对于本研究,使用独特的数据集,其包括来自N=127PB和CSF样品的超过8,000,000个事件,其由四位专家独立地手动标记。应用交叉验证,将GateNet的分类性能与人类专家的性能进行比较。此外,GateNet应用于公开可用的数据集以评估泛化。使用F1分数测量分类性能。
    结果:GateNet取得了从0.910到0.997的F1分数,证明了在训练过程中看不见的样本上的人类水平表现。在公开可用的数据集中,GateNet以0.936的F1评分证实了其泛化能力。重要的是,我们还表明,GateNet只需要≈10个样本就可以达到人类水平的性能。最后,使用GateNet门控使用图形处理单元(GPU)每个事件只需要15微秒。
    结论:GateNet能够在流式细胞术中实现完全端到端自动门控,克服了人工调整的劳动密集型和容易出错的特点。神经网络在看不见的样本上实现了人类水平的性能,并很好地推广到不同的数据集。值得注意的是,它的数据效率,只需要10个样本就能达到人类水平的性能,将GateNet定位为广泛适用于流式细胞术各个领域的工具。
    OBJECTIVE: Flow cytometry is a widely used technique for identifying cell populations in patient-derived fluids, such as peripheral blood (PB) or cerebrospinal fluid (CSF). Despite its ubiquity in research and clinical practice, the process of gating, i.e., manually identifying cell types, is labor-intensive and error-prone. The objective of this study is to address this challenge by introducing GateNet, a neural network architecture designed for fully end-to-end automated gating without the need for correcting batch effects.
    METHODS: For this study a unique dataset is used which comprises over 8,000,000 events from N = 127 PB and CSF samples which were manually labeled independently by four experts. Applying cross-validation, the classification performance of GateNet is compared to the human experts performance. Additionally, GateNet is applied to a publicly available dataset to evaluate generalization. The classification performance is measured using the F1 score.
    RESULTS: GateNet achieves F1 scores ranging from 0.910 to 0.997 demonstrating human-level performance on samples unseen during training. In the publicly available dataset, GateNet confirms its generalization capabilities with an F1 score of 0.936. Importantly, we also show that GateNet only requires ≈10 samples to reach human-level performance. Finally, gating with GateNet only takes 15 microseconds per event utilizing graphics processing units (GPU).
    CONCLUSIONS: GateNet enables fully end-to-end automated gating in flow cytometry, overcoming the labor-intensive and error-prone nature of manual adjustments. The neural network achieves human-level performance on unseen samples and generalizes well to diverse datasets. Notably, its data efficiency, requiring only ∼10 samples to reach human-level performance, positions GateNet as a widely applicable tool across various domains of flow cytometry.
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  • 文章类型: Journal Article
    瞬时受体电位离子通道TRPA1是在感觉神经元中广泛表达的Ca2+渗透性非选择性阳离子通道,但在许多通常具有屏障功能的非神经元组织中,比如皮肤,关节滑膜细胞,角膜,以及呼吸道和肠道。这里,TRPA1的主要作用是检测可能威胁组织稳态和生物体健康的潜在危险刺激。能够直接识别不同模态的信号,包括化学刺激物,极端温度,或渗透变化在于离子通道蛋白复合物的特征特性。低温电子显微镜的最新进展为理解TRPA1功能的分子基础提供了重要的框架,并为寻找其药理调控提供了新的方向。本章从结构和功能角度总结了人类TRPA1的最新知识,并讨论了在生理或病理生理条件下发挥重要作用的激活和调节的复杂变构机制。在这种情况下,概述了TRPA1未来研究的主要挑战。
    The transient receptor potential ion channel TRPA1 is a Ca2+-permeable nonselective cation channel widely expressed in sensory neurons, but also in many nonneuronal tissues typically possessing barrier functions, such as the skin, joint synoviocytes, cornea, and the respiratory and intestinal tracts. Here, the primary role of TRPA1 is to detect potential danger stimuli that may threaten the tissue homeostasis and the health of the organism. The ability to directly recognize signals of different modalities, including chemical irritants, extreme temperatures, or osmotic changes resides in the characteristic properties of the ion channel protein complex. Recent advances in cryo-electron microscopy have provided an important framework for understanding the molecular basis of TRPA1 function and have suggested novel directions in the search for its pharmacological regulation. This chapter summarizes the current knowledge of human TRPA1 from a structural and functional perspective and discusses the complex allosteric mechanisms of activation and modulation that play important roles under physiological or pathophysiological conditions. In this context, major challenges for future research on TRPA1 are outlined.
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  • 文章类型: Journal Article
    (1)背景:最近的出版物促进了肾上腺寡转移或寡进展患者的立体定向放射治疗(SBRT)。然而,非自适应SBRT后的局部控制(LC)显示出改进的潜力。在线自适应MR引导的SBRT(MRgSBRT)改善了肿瘤覆盖率和危险器官(OAR)。自适应MRgSBRT的长期结果仍然是稀疏的。(2)方法:在0.35TMR-Linac上进行自适应MRgSBRT。LC,总生存期(OS),无进展生存期(PFS),总反应率(ORR),和毒性进行了评估。(3)结果:对35例肾上腺转移瘤患者40例进行分析。中位总肿瘤体积为30.6cc。最常见的方案是5Gy的10个分数。中位生物有效剂量(BED10)为75.0Gy。计划适应在所有部分的98%中进行。中位随访时间为7.9个月。16.6个月后发生一次局部故障,估计一年的LC率为100%,两年为90%。ORR为67.5%。中位OS为22.4个月,中位PFS为5.1个月.无毒性>CTCAE2级发生。(4)结论:肾上腺适应性MRgSBRT术后LC和ORR均较好,即使在具有相当大的转移的队列中。与非适应性SBRT相比,75Gy的BED10似乎足以改善LC。
    (1) Background: Recent publications foster stereotactic body radiotherapy (SBRT) in patients with adrenal oligometastases or oligoprogression. However, local control (LC) after non-adaptive SBRT shows the potential for improvement. Online adaptive MR-guided SBRT (MRgSBRT) improves tumor coverage and organ-at-risk (OAR) sparing. Long-term results of adaptive MRgSBRT are still sparse. (2) Methods: Adaptive MRgSBRT was performed on a 0.35 T MR-Linac. LC, overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and toxicity were assessed. (3) Results: 35 patients with 40 adrenal metastases were analyzed. The median gross tumor volume was 30.6 cc. The most common regimen was 10 fractions at 5 Gy. The median biologically effective dose (BED10) was 75.0 Gy. Plan adaptation was performed in 98% of all fractions. The median follow-up was 7.9 months. One local failure occurred after 16.6 months, resulting in estimated LC rates of 100% at one year and 90% at two years. ORR was 67.5%. The median OS was 22.4 months, and the median PFS was 5.1 months. No toxicity > CTCAE grade 2 occurred. (4) Conclusions: LC and ORR after adrenal adaptive MRgSBRT were excellent, even in a cohort with comparably large metastases. A BED10 of 75 Gy seems sufficient for improved LC in comparison to non-adaptive SBRT.
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  • 文章类型: Journal Article
    酶4-羟基苯基丙酮酸双加氧酶(4-HPPD)参与细菌等生物体中氨基酸酪氨酸的分解代谢,植物,和动物。在分子氧和Fe(II)作为辅因子的存在下,它催化4-羟基苯基丙酮酸转化为匀浆。这种酶代表了重要化合物生物合成的关键步骤,它的活性缺乏导致严重的,罕见的常染色体隐性遗传疾病,比如III型酪氨酸血症和霍金蛋白尿,目前尚无治愈方法。4-HPPDC末端尾部在酶催化/门控机制中起着至关重要的作用,通过对C端尾部构象的精细调节来确保催化活性位点的完整性。然而,尽管人们对4-HPPD的催化机理和结构越来越感兴趣,门控机制尚不清楚.此外,整个3D结构的缺乏使得生物信息学方法成为定义酶结构/分子机制的唯一可能的研究。这里,通过应用全面的生物信息学/进化研究,对野生型4-HPPD及其突变体进行了深入解剖,我们首次展示了酶门控过程的整个分子机制和调控,提出了人4-HPPD的全长3D结构和涉及4-HPPDC末端尾部构象变化的两个新的关键残基。
    The enzyme 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) is involved in the catabolism of the amino acid tyrosine in organisms such as bacteria, plants, and animals. It catalyzes the conversion of 4-hydroxyphenylpyruvate to a homogenisate in the presence of molecular oxygen and Fe(II) as a cofactor. This enzyme represents a key step in the biosynthesis of important compounds, and its activity deficiency leads to severe, rare autosomal recessive disorders, like tyrosinemia type III and hawkinsinuria, for which no cure is currently available. The 4-HPPD C-terminal tail plays a crucial role in the enzyme catalysis/gating mechanism, ensuring the integrity of the active site for catalysis through fine regulation of the C-terminal tail conformation. However, despite growing interest in the 4-HPPD catalytic mechanism and structure, the gating mechanism remains unclear. Furthermore, the absence of the whole 3D structure makes the bioinformatic approach the only possible study to define the enzyme structure/molecular mechanism. Here, wild-type 4-HPPD and its mutants were deeply dissected by applying a comprehensive bioinformatics/evolution study, and we showed for the first time the entire molecular mechanism and regulation of the enzyme gating process, proposing the full-length 3D structure of human 4-HPPD and two novel key residues involved in the 4-HPPD C-terminal tail conformational change.
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  • 文章类型: Journal Article
    皮质听觉诱发电位(CAEP)表明噪声降低了听觉神经编码,导致峰值振幅降低和峰值潜伏期增加。不同类型的噪声影响CAEP响应,更大的信息掩蔽导致额外的降解。在嘈杂的条件下,注意力可以改善目标信号的神经编码,由增加的CAEP振幅反映,这可能是通过各种抑制机制在注意前和注意水平促进。虽然以前的研究主要集中在噪声中注意力听觉处理过程中的抑制作用,注意前阶段噪声对神经反应的影响尚不清楚.因此,这项初步研究旨在评估听觉门控反应,反射感觉抑制阶段,重复的元音对呈现在背景噪声中。在安静和噪音条件下,通过高密度EEG记录了15名听力正常的成年人的CAEP,并提供了低信息和高信息掩蔽。在不同条件下比较了一对中每个元音引起的平均CAEP峰值幅度之间的差异。生成头皮图以观察每种条件下的一般皮质抑制网络。在安静中发生了重大的门控,而噪声条件导致门控响应显着降低。门控函数在具有较少信息掩蔽内容的噪声中显著降低,与抑制门控网络的激活减少相吻合。这些发现说明了噪声对与语音感知有关的注意前抑制的不利影响。
    Cortical auditory evoked potentials (CAEPs) indicate that noise degrades auditory neural encoding, causing decreased peak amplitude and increased peak latency. Different types of noise affect CAEP responses, with greater informational masking causing additional degradation. In noisy conditions, attention can improve target signals\' neural encoding, reflected by an increased CAEP amplitude, which may be facilitated through various inhibitory mechanisms at both pre-attentive and attentive levels. While previous research has mainly focused on inhibition effects during attentive auditory processing in noise, the impact of noise on the neural response during the pre-attentive phase remains unclear. Therefore, this preliminary study aimed to assess the auditory gating response, reflective of the sensory inhibitory stage, to repeated vowel pairs presented in background noise. CAEPs were recorded via high-density EEG in fifteen normal-hearing adults in quiet and noise conditions with low and high informational masking. The difference between the average CAEP peak amplitude evoked by each vowel in the pair was compared across conditions. Scalp maps were generated to observe general cortical inhibitory networks in each condition. Significant gating occurred in quiet, while noise conditions resulted in a significantly decreased gating response. The gating function was significantly degraded in noise with less informational masking content, coinciding with a reduced activation of inhibitory gating networks. These findings illustrate the adverse effect of noise on pre-attentive inhibition related to speech perception.
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  • 文章类型: Journal Article
    目的:为了精确的肺部立体定向放射治疗,应在束传递过程中获取目标位置。我们旨在在相位门控条件下在光束辐照(辐照内成像)期间进行千伏(kV)成像,并评估其性能。
    方法:使用Catphan504和QUASAR呼吸运动体模评估图像质量和目标可检测性,分别。使用了TrueBeamSTx直线加速器和开发者模式。成像参数为125kVp和1.2mAs/投影。使用平坦的兆伏(MV)X射线束能量6、10和15MV以及未平坦的束能量6和10MV,场大小为5×5和15×15cm2,并且具有各种帧速率,用于照射内成像。此外,使用量子幻影,在调强计划实施期间进行照射内成像.插入杆的CT数的均方根误差(RMSE),图像噪声,视觉评估,和对比噪声比(CNR)进行了评估。
    结果:门控条件下辐照内锥形束计算机断层扫描(CBCT)图像的RMSE为50-230Hounsfield单位(HU)(静态<30HU)。门控条件下照射内CBCT图像的噪声为15-35HU,而标准CBCT图像为8.8-27.2HU。较低的帧速率表现出较大的RMSE和噪声;然而,迭代重建算法(IR)在改善这些值方面是有效的。具有IR的大约7fps显示出没有IR的15fps的等效CNR。目标在所有门控照射内CBCT图像上可见。
    结论:需要改善图像质量;然而,照射内CBCT图像显示良好的视觉目标检测。
    OBJECTIVE: Target positions should be acquired during beam delivery for accurate lung stereotactic body radiotherapy. We aimed to perform kilovoltage (kV) imaging during beam irradiation (intra-irradiation imaging) under phase-gated conditions and evaluate its performance.
    METHODS: Catphan 504 and QUASAR respiratory motion phantoms were used to evaluate image quality and target detectability, respectively. TrueBeam STx linac and the Developer Mode was used. The imaging parameters were 125 kVp and 1.2 mAs/projection. Flattened megavoltage (MV) X-ray beam energies 6, 10 and 15 MV and un-flattened beam energies 6 and 10 MV were used with field sizes of 5 × 5 and 15 × 15 cm2 and various frame rates for intra-irradiation imaging. In addition, using a QUASAR phantom, intra-irradiation imaging was performed during intensity-modulated plan delivery. The root-mean-square error (RMSE) of the CT-number for the inserted rods, image noise, visual assessment, and contrast-to-noise ratio (CNR) were evaluated.
    RESULTS: The RMSEs of intra-irradiation cone-beam computed tomography (CBCT) images under gated conditions were 50-230 Hounsfield Unit (HU) (static < 30 HU). The noise of the intra-irradiation CBCT images under gated conditions was 15-35 HU, whereas that of the standard CBCT images was 8.8-27.2 HU. Lower frame rates exhibited large RMSEs and noise; however, the iterative reconstruction algorithm (IR) was effective at improving these values. Approximately 7 fps with the IR showed an equivalent CNR of 15 fps without the IR. The target was visible on all the gated intra-irradiation CBCT images.
    CONCLUSIONS: Several image quality improvements are required; however, intra-irradiated CBCT images showed good visual target detection.
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