当前共找到 1331 篇文献分享,本页显示第 481 - 500 篇。
481.
DeDe宝
(2023-12-13 23:02):
#paper,https://doi.org/10.7554/eLife.55389,A Bayesian and efficient observer model explains concurrent attractive and repulsive history biases in visual perception,人类的视觉感知受到历史经验的影响,同时产生排斥性偏差和吸引性偏差,且二者具有不同的时间尺度:吸引性偏差的衰减速度快,只由上一个试次刺激影响产生,排斥性偏差衰减速度慢,可以持续受到过去数分钟的刺激的影响,暗示吸引性和排斥性偏差的机制是分离的。但是,目前仍不清楚吸引性的偏差和排斥性的偏差在知觉决策过程中是否相互作用以及如何相互作用。这篇研究结合了快速编码框架和贝叶斯解码模型,同时捕获了吸引性偏差和排斥性偏差的关键特征。
Abstract:
Human perceptual decisions can be repelled away from (repulsive adaptation) or attracted towards recent visual experience (attractive serial dependence). It is currently unclear whether and how these repulsive and attractive …
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Human perceptual decisions can be repelled away from (repulsive adaptation) or attracted towards recent visual experience (attractive serial dependence). It is currently unclear whether and how these repulsive and attractive biases interact during visual processing and what computational principles underlie these history dependencies. Here we disentangle repulsive and attractive biases by exploring their respective timescales. We find that perceptual decisions are concurrently attracted towards the short-term perceptual history and repelled from stimuli experienced up to minutes into the past. The temporal pattern of short-term attraction and long-term repulsion cannot be captured by an ideal Bayesian observer model alone. Instead, it is well captured by an ideal observer model with efficient encoding and Bayesian decoding of visual information in a slowly changing environment. Concurrent attractive and repulsive history biases in perceptual decisions may thus be the consequence of the need for visual processing to simultaneously satisfy constraints of efficiency and stability.
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482.
林海onrush
(2023-12-01 00:00):
#paper, https://doi.org/10.1038/s41562-019-0804-2,Quantum reinforcement learning during human
decision-making,这篇nature子刊很有意思,探讨了量子强化学习(QRL)在人类决策中的应用。QRL在人类决策中的新颖应用:该研究是首次将QRL应用于人类决策的实证研究。QRL在计算机模拟中表现出色,但此研究首次在人类决策环境中对其进行了特殊测试。研究利用了参与者在执行爱荷华赌博任务时的行为数据和功能性磁共振成像(fMRI)数据,将2个QRL模型与12个已建立的CRL模型进行了对比。研究者开发了两种新的QRL模型:量子叠加状态学习(QSL)和量子叠加状态加持续性(QSPP)。这些模型的表现在某些方面优于最好的CRL模型。这一发现在包括健康个体和吸烟者在内的不同受试者群体中得到了确认,表明这些模型的稳健性和普遍适用性。量子类过程的神经表征:该研究的一个重要创新是确定了表示量子类过程的神经基质。例如,QSPP模型显示了在大脑中如何表征量子距离和转换幅度——QRL的关键概念。这一发现弥合了认知量子模型和神经科学之间的差距,为决策中的量子类过程提供了神经生物学基础。对于决策中的不确定性理解,论文还探讨了决策中不确定性的角色。通过将QSPP模型与CRL模型(VPPDecayTIC)进行比较,突出了大脑如何不同地处理由不稳定的外部环境影响的内部状态不确定性。这一研究方面强调了QRL模型在提供对决策认知过程更细微洞察方面的潜力。
Abstract:
Classical reinforcement learning (CRL) has been widely applied in neuroscience and psychology; however, quantum reinforcement learning (QRL), which shows superior performance in computer simulations, has never been empirically tested on …
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Classical reinforcement learning (CRL) has been widely applied in neuroscience and psychology; however, quantum reinforcement learning (QRL), which shows superior performance in computer simulations, has never been empirically tested on human decision-making. Moreover, all current successful quantum models for human cognition lack connections to neuroscience. Here we studied whether QRL can properly explain value-based decision-making. We compared 2 QRL and 12 CRL models by using behavioural and functional magnetic resonance imaging data from healthy and cigarette-smoking subjects performing the Iowa Gambling Task. In all groups, the QRL models performed well when compared with the best CRL models and further revealed the representation of quantum-like internal-state-related variables in the medial frontal gyrus in both healthy subjects and smokers, suggesting that value-based decision-making can be illustrated by QRL at both the behavioural and neural levels.
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483.
小W
(2023-11-30 23:40):
#paper doi:doi.org/10.1038/s41551-023-01114-1 Detection of cellular traction forces via the force-triggered Cas12a-mediated catalytic cleavage of a fluorogenic reporter strand 本文介绍了利用CRISPR相关蛋白(Cas)-Cas12a 检测活细胞表面受体分子力事件的方法,其技术路径:激活剂是固定在表面(如玻璃载玻片)上的ssDNA,激活剂通过与互补链杂交而被隐藏,互补链又与配体肽结合;当细胞被植入该表面时,表面受体和配体结合,并施加力,超过双链的机械耐受性的力会导致其断裂,暴露激活剂;激活Cas12a会高效地催化切割荧光性ssDNA报告基因。在作为测试的血小板力检测中,其具有以下优势1.活细胞2.只需要~5 μl或更少的血液来进行每次测量,降低了高通量筛选的难度3.检测结果与出血风险更高的相关4.更短的时间(30min),更易识别的信号,可能更低的成本。对 CRISPR 检测不太了解,欢迎斧正。
Abstract:
Molecular forces generated by cell receptors are infrequent and transient, and hence difficult to detect. Here we report an assay that leverages the CRISPR-associated protein 12a (Cas12a) to amplify the …
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Molecular forces generated by cell receptors are infrequent and transient, and hence difficult to detect. Here we report an assay that leverages the CRISPR-associated protein 12a (Cas12a) to amplify the detection of cellular traction forces generated by as few as 50 adherent cells. The assay involves the immobilization of a DNA duplex modified with a ligand specific for a cell receptor. Traction forces of tens of piconewtons trigger the dehybridization of the duplex, exposing a cryptic Cas12-activating strand that sets off the indiscriminate Cas12-mediated cleavage of a fluorogenic reporter strand. We used the assay to perform hundreds of force measurements using human platelets from a single blood draw to extract individualized dose-response curves and half-maximal inhibitory concentrations for a panel of antiplatelet drugs. For seven patients who had undergone cardiopulmonary bypass, platelet dysfunction strongly correlated with the need for platelet transfusion to limit bleeding. The Cas12a-mediated detection of cellular traction forces may be used to assess cell state, and to screen for genes, cell-adhesion ligands, drugs or metabolites that modulate cell mechanics.
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484.
钟鸣
(2023-11-30 23:39):
#paper doi: 10.1002/ctm2.1354 IMPACT: A web server for exploring immunotherapeutic predictive and cancer prognostic biomarkers
这是一篇临床转化医学的数据库的文章,作者来自燃石、中国国家肿瘤中心等单位。数据库纳入了23000+样品、覆盖37种肿瘤,数据来源包括公共数据库、文献来源的数据集以及作者自己收集的一系列数据。数据库的主旨是挖掘和分析影响肿瘤预后的生物标志物。数据库功能还是比较多的,与既有的数据库相比更加灵活和细化,操作比较简便和直观,界面简洁一目了然,使用者可快速执行感兴趣的操作,提高分析效率。
Abstract:
No abstract available.
485.
Ricardo
(2023-11-30 23:19):
#paper 10.1109/TMI.2022.3174827 PTNet3D: A 3D High-Resolution Longitudinal
Infant Brain MRI Synthesizer Based on Transformers 最近看了一些基于GAN的医学图像生成的文章(当然现在的热点都转向diffusion model了),感觉都很没有创意,有点无聊,并且都存在一些共性问题。第一,纵向婴幼儿图像生成算法仅仅是通过在每个年龄段训练模型来构建,完全可以把年龄作为条件直接生成;第二,为了缓解数据维度高且数据量小的问题,大多数这类生成算法都基于slice或者patch的生成方式,不可避免的会导致生成图像的不连续性,而且基本上所有文章都没解决这个问题。在我的新工作(不是单纯的图像生成任务)里,这些问题都得到了重视并予以解决,估计年后会release预印本出来,敬请期待。
IF:8.900Q1
IEEE transactions on medical imaging,
2022-10.
DOI: 10.1109/TMI.2022.3174827
PMID: 35560070
Abstract:
An increased interest in longitudinal neurodevelopment during the first few years after birth has emerged in recent years. Noninvasive magnetic resonance imaging (MRI) can provide crucial information about the development …
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An increased interest in longitudinal neurodevelopment during the first few years after birth has emerged in recent years. Noninvasive magnetic resonance imaging (MRI) can provide crucial information about the development of brain structures in the early months of life. Despite the success of MRI collections and analysis for adults, it remains a challenge for researchers to collect high-quality multimodal MRIs from developing infant brains because of their irregular sleep pattern, limited attention, inability to follow instructions to stay still during scanning. In addition, there are limited analytic approaches available. These challenges often lead to a significant reduction of usable MRI scans and pose a problem for modeling neurodevelopmental trajectories. Researchers have explored solving this problem by synthesizing realistic MRIs to replace corrupted ones. Among synthesis methods, the convolutional neural network-based (CNN-based) generative adversarial networks (GANs) have demonstrated promising performance. In this study, we introduced a novel 3D MRI synthesis framework- pyramid transformer network (PTNet3D)- which relies on attention mechanisms through transformer and performer layers. We conducted extensive experiments on high-resolution Developing Human Connectome Project (dHCP) and longitudinal Baby Connectome Project (BCP) datasets. Compared with CNN-based GANs, PTNet3D consistently shows superior synthesis accuracy and superior generalization on two independent, large-scale infant brain MRI datasets. Notably, we demonstrate that PTNet3D synthesized more realistic scans than CNN-based models when the input is from multi-age subjects. Potential applications of PTNet3D include synthesizing corrupted or missing images. By replacing corrupted scans with synthesized ones, we observed significant improvement in infant whole brain segmentation.
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486.
符毓
(2023-11-30 23:11):
#paper doi.org/10.48550/arXiv.2311.05332, 2023, On the Road with GPT-4V(ision): Early Explorations of Visual-Language Model on Autonomous Driving. 文远知行的团队近期的论文,把GPT应用在自动驾驶领域。测试结果显示GPT在图像识别,点云识别,天气识别,V2X图像,模拟图像识别,多角度图片识别都有较高准确率;在交通灯识别,左右空间区分上容易出错
arXiv,
2023.
DOI: 10.48550/arXiv.2311.05332
Abstract:
The pursuit of autonomous driving technology hinges on the sophisticatedintegration of perception, decision-making, and control systems. Traditionalapproaches, both data-driven and rule-based, have been hindered by theirinability to grasp the nuance …
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The pursuit of autonomous driving technology hinges on the sophisticatedintegration of perception, decision-making, and control systems. Traditionalapproaches, both data-driven and rule-based, have been hindered by theirinability to grasp the nuance of complex driving environments and theintentions of other road users. This has been a significant bottleneck,particularly in the development of common sense reasoning and nuanced sceneunderstanding necessary for safe and reliable autonomous driving. The advent ofVisual Language Models (VLM) represents a novel frontier in realizing fullyautonomous vehicle driving. This report provides an exhaustive evaluation ofthe latest state-of-the-art VLM, GPT-4V(ision), and its application inautonomous driving scenarios. We explore the model's abilities to understandand reason about driving scenes, make decisions, and ultimately act in thecapacity of a driver. Our comprehensive tests span from basic scene recognitionto complex causal reasoning and real-time decision-making under varyingconditions. Our findings reveal that GPT-4V demonstrates superior performancein scene understanding and causal reasoning compared to existing autonomoussystems. It showcases the potential to handle out-of-distribution scenarios,recognize intentions, and make informed decisions in real driving contexts.However, challenges remain, particularly in direction discernment, trafficlight recognition, vision grounding, and spatial reasoning tasks. Theselimitations underscore the need for further research and development. Projectis now available on GitHub for interested parties to access and utilize:\url{https://github.com/PJLab-ADG/GPT4V-AD-Exploration}
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487.
muton
(2023-11-30 23:05):
#paper: Schonhaut, D. R., Aghajan, Z. M., Kahana, M. J., & Fried, I. (2023). A neural code for time and space in the human brain. Cell Reports, 42(11). https://doi.org/10.1016/j.celrep.2023.113238 时间和空间对人类的记忆来说是非常重要的两个维度,不仅可以帮助构建我们的经验,也可以帮助我们预测未来。以往有部分研究发现了时间和空间的神经关联,比如时间细胞和位置细胞的发现等。但是这两个维度是如何在个体记忆中被整合的仍未可知。作者基于这一问题记录了在定时性空间导航虚拟游戏中10个病人的单细胞放电情况,任务分为延迟等待阶段,寻金时间(编码阶段),下一个延迟等待阶段和挖金阶段(提取阶段)。结果发现,内侧颞叶和前额叶皮层神经元在无任务延迟期间编码时间信息,在空间探索过程中,时间和位置是独立表征的,时间细胞会在相似的事件下重新编码(remap)但是位置细胞仍会以稳定的模式放电,群体神经活动代表序列中多个事件的时间信息。本文的亮点在于首次在人类中同时研究了时间和空间信息在记忆形成中的放电特征。
Abstract:
Time and space are primary dimensions of human experience. Separate lines of investigation have identified neural correlates of time and space, yet little is known about how these representations converge …
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Time and space are primary dimensions of human experience. Separate lines of investigation have identified neural correlates of time and space, yet little is known about how these representations converge during self-guided experience. Here, 10 subjects with intracranially implanted microelectrodes play a timed, virtual navigation game featuring object search and retrieval tasks separated by fixed delays. Time cells and place cells activate in parallel during timed navigation intervals, whereas a separate time cell sequence spans inter-task delays. The prevalence, firing rates, and behavioral coding strengths of time cells and place cells are indistinguishable-yet time cells selectively remap between search and retrieval tasks, while place cell responses remain stable. Thus, the brain can represent time and space as overlapping but dissociable dimensions. Time cells and place cells may constitute a biological basis for the cognitive map of spatiotemporal context onto which memories are written.
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488.
白鸟
(2023-11-30 22:58):
#paper https://doi.org/10.1111/imm.13441 Velikkakam, T, Gollob, KJ, and Dutra, WO. Double-negative T cells: setting the stage for disease control or progression. Immunology. (2022) 165:371–85. 这篇文献是关于双阴性T细胞DNT的综述文章。DNT是一群独特的T细胞,缺乏CD4和CD8辅助受体,但表达αβ TCR或γδ TCR,在人外周血中占比较低。DNT细胞能有效产生细胞因子,是免疫反应的关键协调者。1.DNT从哪里来?DNT 的确切来源仍有很多盲点,有研究表明DNT细胞可以源自胸腺和外周环境。外周血中DNT细胞可以通过可能逃避胸腺中的负选择以及随后在外周中的激活和扩增。另外,体外也可诱导产生DNT细胞。2.DNT亚群:存在高度异质性,未有正式定义,来源不同研究课题,如初始nDNT和激活态aDNT。3.DNT与疾病:它是多种人类疾病的发病机制的主角,特别是自身免疫疾病、炎症性疾病和移植。其调节功能损害了必要的炎症效应机制,或者介导细胞死亡和组织破坏。多数文献DNT研究源自小鼠模型,许多是转基因的。人类DNT会有所区别,还是需要系统的梳理DNT细胞的功能和在疾病中的作用。
Abstract:
Double-negative (DN) T cells are present at relatively low frequencies in human peripheral blood, and are characterized as expressing the alpha-beta or gamma-delta T-cell receptor (TCR), but not the CD4 …
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Double-negative (DN) T cells are present at relatively low frequencies in human peripheral blood, and are characterized as expressing the alpha-beta or gamma-delta T-cell receptor (TCR), but not the CD4 nor the CD8 co-receptors. Despite their low frequencies, these cells are potent producers of cytokines and, thus, are key orchestrators of immune responses. DN T cells were initially associated with induction of peripheral immunological tolerance and immunomodulatory activities related to disease prevention. However, other studies demonstrated that these cells can also display effector functions associated with pathology development. This apparent contradiction highlighted the heterogeneity of the DN T-cell population. Here, we review phenotypic and functional characteristics of DN T cells, emphasizing their role in human diseases. The need for developing biomarkers to facilitate the translation of studies from animal models to humans will also be discussed. Finally, we will examine DN T cells as promising therapeutic targets to prevent or inhibit human disease development.
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489.
半面阳光
(2023-11-30 22:19):
#paper https://doi.org/10.3390/genes12040478, gene, 2021,Performance of Cell-Free DNA Screening for Fetal Common Aneuploidies and Sex Chromosomal Abnormalities: A Prospective Study from a Less Developed Autonomous Region in Mainland China. 这篇前瞻性研究论文主要分析研究了NIPT在86193例人群样本中对常见的T21,T18,T13三体异常、性染色体异常以及其他常染色体异常和一些CNVs中的检测效果。相对而言,这篇文章的突出特点是样本量比较大,阳性检出率和阳性预测值等这些检测性能上的参数给出了一定的参考。
Abstract:
To evaluate the performance of noninvasive prenatal screening (NIPS) in the detection of common aneuploidies in a population-based study, a total of 86,262 single pregnancies referred for NIPS were prospectively …
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To evaluate the performance of noninvasive prenatal screening (NIPS) in the detection of common aneuploidies in a population-based study, a total of 86,262 single pregnancies referred for NIPS were prospectively recruited. Among 86,193 pregnancies with reportable results, follow-up was successfully conducted in 1160 fetuses reported with a high-risk result by NIPS and 82,511 cases (95.7%) with a low-risk result. The screen-positive rate (SPR) of common aneuploidies and sex chromosome abnormalities (SCAs) provided by NIPS were 0.7% (586/83,671) and 0.6% (505/83,671), respectively. The positive predictive values (PPVs) for Trisomy 21, Trisomy 18, Trisomy 13 and SCAs were calculated as 89.7%, 84.0%, 52.6% and 38.0%, respectively. In addition, less rare chromosomal abnormalities, including copy number variants (CNVs), were detected, compared with those reported by NIPS with higher read-depth. Among these rare abnormalities, only 23.2% (13/56) were confirmed by prenatal diagnosis. In total, four common trisomy cases were found to be false negative, resulting in a rate of 0.48/10,000 (4/83,671). In summary, this study conducted in an underdeveloped region with limited support for the new technology development and lack of cost-effective prenatal testing demonstrates the importance of implementing routine aneuploidy screening in the public sector for providing early detection and precise prognostic information.
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490.
大勇
(2023-11-30 21:45):
#paper https://doi.org/10.1038/s41586-023-05710-8 Nassour, J., Aguiar, L.G., Correia, A. et al. Telomere-to-mitochondria signalling by ZBP1 mediates replicative crisis. Nature 614, 767–773 (2023). 这篇文献主要是发现了永生化细胞不死的机制,通过讲端粒、衰老和和免疫结合起来,从侧面为肿瘤细胞的异常增殖提供了新的思路。全文仅仅用了简单的WB和免疫荧光等技术,完成了比较有创新性的课题并发表在了nature上。整篇文献发现永生化细胞中ZBP1表达升高和I型干扰素信号通路激活,通过分析发现ZBP1可以与端粒不稳定相关RNA结合并定位于线粒体上,从而激活MAVS和下游I型干扰素信号通路维持细胞的生长,而端粒的不稳定又会激活cGAS信号通路,引起I型干扰素信号通路激活导致ZBP1升高,从而形成了一个环路。
Abstract:
Cancers arise through the accumulation of genetic and epigenetic alterations that enable cells to evade telomere-based proliferative barriers and achieve immortality. One such barrier is replicative crisis-an autophagy-dependent program that …
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Cancers arise through the accumulation of genetic and epigenetic alterations that enable cells to evade telomere-based proliferative barriers and achieve immortality. One such barrier is replicative crisis-an autophagy-dependent program that eliminates checkpoint-deficient cells with unstable telomeres and other cancer-relevant chromosomal aberrations. However, little is known about the molecular events that regulate the onset of this important tumour-suppressive barrier. Here we identified the innate immune sensor Z-DNA binding protein 1 (ZBP1) as a regulator of the crisis program. A crisis-associated isoform of ZBP1 is induced by the cGAS-STING DNA-sensing pathway, but reaches full activation only when associated with telomeric-repeat-containing RNA (TERRA) transcripts that are synthesized from dysfunctional telomeres. TERRA-bound ZBP1 oligomerizes into filaments on the outer mitochondrial membrane of a subset of mitochondria, where it activates the innate immune adapter protein mitochondrial antiviral-signalling protein (MAVS). We propose that these oligomerization properties of ZBP1 serve as a signal amplification mechanism, where few TERRA-ZBP1 interactions are sufficient to launch a detrimental MAVS-dependent interferon response. Our study reveals a mechanism for telomere-mediated tumour suppression, whereby dysfunctional telomeres activate innate immune responses through mitochondrial TERRA-ZBP1 complexes to eliminate cells destined for neoplastic transformation.
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491.
庞庞
(2023-11-30 19:59):
#paper doi:https://doi.org/10.1016/j.neuroimage.2019.01.074 Reproducibility of functional brain alterations in major depressive disorder: Evidence from a multisite resting-state functional MRI study with 1,434 individuals 静息态功能磁共振成像研究表明,重度抑郁症患者的脑功能存在广泛的改变。 然而,由于大样本、多站点数据集的稀缺,关于 MDD 相关改变的可重复模式的清晰一致的结论仍然有限。 研究者过五个中心的 1434 名参与者(709 名 MDD 患者和 725 名健康对照)的大型 R-fMRI 数据集来解决这个问题。 我们观察到,与对照组相比,重度抑郁症患者的眶额皮层、感觉运动皮层和视觉皮层显著减退,额顶皮层显著过度活跃。 这些改变不受不同统计分析策略、全局信号回归和药物状态的影响,并且通常可以在各个中心重现。 然而,这些组间差异部分受到患者发病状态和发病年龄的影响,并且脑-临床变量关系表现出较差的跨中心再现性
Abstract:
Resting-state functional MRI (R-fMRI) studies have demonstrated widespread alterations in brain function in patients with major depressive disorder (MDD). However, a clear and consistent conclusion regarding a repeatable pattern of …
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Resting-state functional MRI (R-fMRI) studies have demonstrated widespread alterations in brain function in patients with major depressive disorder (MDD). However, a clear and consistent conclusion regarding a repeatable pattern of MDD-relevant alterations is still limited due to the scarcity of large-sample, multisite datasets. Here, we address this issue by including a large R-fMRI dataset with 1434 participants (709 patients with MDD and 725 healthy controls) from five centers in China. Individual functional activity maps that represent very local to long-range connections are computed using the amplitude of low-frequency fluctuations, regional homogeneity and distance-related functional connectivity strength. The reproducibility analyses involve different statistical strategies, global signal regression, across-center consistency, clinical variables, and sample size. We observed significant hypoactivity in the orbitofrontal, sensorimotor, and visual cortices and hyperactivity in the frontoparietal cortices in MDD patients compared to the controls. These alterations are not affected by different statistical analysis strategies, global signal regression and medication status and are generally reproducible across centers. However, these between-group differences are partially influenced by the episode status and the age of disease onset in patients, and the brain-clinical variable relationship exhibits poor cross-center reproducibility. Bootstrap analyses reveal that at least 400 subjects in each group are required to replicate significant alterations (an extent threshold of P < .05 and a height threshold of P < .001) at 50% reproducibility. Together, these results highlight reproducible patterns of functional alterations in MDD and relevant influencing factors, which provides crucial guidance for future neuroimaging studies of this disorder.
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492.
朵朵
(2023-11-30 19:20):
#paper 王伟. “她为什么换了导师——一项导生关系的案例研究.” 华东师范大学硕士学位论文.
近年来导师和研究生的关系恶化的事件时有发生,看到这篇论文,一个是抱着八卦的心态,想看看“她到底为啥换了导师”,另外一个是好奇,作者是怎么把一起换导师事件做成一项研究的,用什么样的研究方法可以使其成为一篇硕士研究生论文。
读下来发现研究方法并不难,主要是做访谈,再加一些文献阅读与分析。作者访谈了换导师的A同学,A同学的同门师兄B,A同学的同寝室同学C,以及A同学换的新导师Z。可惜A同学的原导师Y并不愿意接受访谈,因此少了她的视角。通过访谈还原了整个换导师过程:A同学本来选择的另一个导师,被调剂到导师Y门下,一进师门就给了个下马威:随时可以走。之后写论文的选题成为导火索,A同学想要写的选题,导师Y不认可;导师Y给A同学定的选题和大纲,A同学不认可,认为导师学术水平不高,但又不敢违背,再加上在实习问题上的矛盾,A同学萌生退学、拿不到毕业证的想法。后来在系里帮助下,A同学换了新导师。
在厘清基本事实后,作者对我国现行导师制进行了分析,认为导师-学生匹配上的责权不一、导生互动中教育性和学术性的淡化以及评价机制的缺失是值得反映的问题。
有意思的案例研究,但是深度稍显欠缺,是一篇评论能容纳的信息量。
493.
尹志
(2023-11-30 16:36):
#paper Hamed Khakzad, Ilia Igashov, Arne Schneuing, et al. A new age in protein design empowered by deep learning. Cell Systems 14, 925–939 (2023). https://doi.org/10.1016/j.cels.2023.10.006.
蛋白质作为细胞的主要组成,参与了包括酶促反应、信号转导等在内的各种生命反应,其意义毋庸置疑。但是如何通过人工的方式设计特定的蛋白质,从而解决疾病治疗、药物研发等一系列生命科学问题,一直是科学家的追求。人工智能的发展,特别是深度学习的发展,给这个主题带来了特别巨大的进展。这篇最新的综述就是对使用深度学习进行蛋白质设计的几类范式和sota方法进行了介绍。从方法角度看,介绍的非常全面。有意思的是,我们会发现目前生成式模型在AI的冲击已经迁移到蛋白质设计领域,并孵化出独有的味道。图神经网络、物理启发的模型、语言模型的模仿、深度生成模型的利用在蛋白质设计领域都展现出不错的性能,特别是当把几何先验通过数学的手段,比如群轮与深度学习进行结合,往往可以较好的捕获蛋白质精巧晦涩的结构信息。当然,考虑到蛋白质设计所涉及的序列、结构、功能三者的精密联系,如何协调序列建模、结构建模等方法,也成为未来发展的关键问题。文章中对数据、benchmark等方面的讨论也很有价值。当然,问题也是一大堆,最令人不爽的是,拥有生命科学基本属性的蛋白质设计,最终的效果需要实验甚至实际效果进行验证,因此计算方法论上再优秀的设计,也需要湿实验、临床实验的验证。希望随着技术的进步,这个领域的自动化agent技术会带来全新的范式。
Abstract:
The rapid progress in the field of deep learning has had a significant impact on protein design. Deep learning methods have recently produced a breakthrough in protein structure prediction, leading …
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The rapid progress in the field of deep learning has had a significant impact on protein design. Deep learning methods have recently produced a breakthrough in protein structure prediction, leading to the availability of high-quality models for millions of proteins. Along with novel architectures for generative modeling and sequence analysis, they have revolutionized the protein design field in the past few years remarkably by improving the accuracy and ability to identify novel protein sequences and structures. Deep neural networks can now learn and extract the fundamental features of protein structures, predict how they interact with other biomolecules, and have the potential to create new effective drugs for treating disease. As their applicability in protein design is rapidly growing, we review the recent developments and technology in deep learning methods and provide examples of their performance to generate novel functional proteins.
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494.
Vincent
(2023-11-30 16:34):
#paper Contrastive Variational Autoencoder Enhances Salient Features, arxiv, 2019 https://arxiv.org/abs/1902.04601 最近的对比PCA采用了对比学习的思路,能够捕捉目标数据集与背景之间的差异,从而实现保留对比信号的无监督降维。然而对比PCA跟PCA类似,只能对变量做线性组合进行降维,无法捕捉变量间的非线性关系。这篇文章对对比PCA做了拓展,使用变分自编码模型(VAE)来实现对非线性关系的捕捉,该方法称为对比VAE。对比VAE通过对数据集间的共享特征以及富集在目标数据中的特征进行显式建模,从而分离和增强目标数据中的突出潜在特征。该方法的运算时间与VAE类似,并且对噪音和数据纯度有较高的鲁棒性。文章在多个数据集上(例如手写数字MNIST)验证了该方法在捕捉突出潜在特征方面的有效性,比起传统的VAE也有持续提高。同时其作为一种生成式学习工具,训练好以后也能够用这些显著潜在特征来生成新的数据。
arXiv,
2019.
DOI: 10.48550/arXiv.1902.04601
Abstract:
Variational autoencoders are powerful algorithms for identifying dominantlatent structure in a single dataset. In many applications, however, we areinterested in modeling latent structure and variation that are enriched in atarget …
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Variational autoencoders are powerful algorithms for identifying dominantlatent structure in a single dataset. In many applications, however, we areinterested in modeling latent structure and variation that are enriched in atarget dataset compared to some background---e.g. enriched in patients comparedto the general population. Contrastive learning is a principled framework tocapture such enriched variation between the target and background, butstate-of-the-art contrastive methods are limited to linear models. In thispaper, we introduce the contrastive variational autoencoder (cVAE), whichcombines the benefits of contrastive learning with the power of deep generativemodels. The cVAE is designed to identify and enhance salient latent features.The cVAE is trained on two related but unpaired datasets, one of which hasminimal contribution from the salient latent features. The cVAE explicitlymodels latent features that are shared between the datasets, as well as thosethat are enriched in one dataset relative to the other, which allows thealgorithm to isolate and enhance the salient latent features. The algorithm isstraightforward to implement, has a similar run-time to the standard VAE, andis robust to noise and dataset purity. We conduct experiments across diversetypes of data, including gene expression and facial images, showing that thecVAE effectively uncovers latent structure that is salient in a particularanalysis.
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495.
小年
(2023-11-30 16:01):
#paper Augusto, D.G., Murdolo, L.D., Chatzileontiadou, D.S.M. et al. A common allele of HLA is associated with asymptomatic SARS-CoV-2 infection. Nature 620, 128–136 (2023). https://doi.org/10.1038/s41586-023-06331-x.
大多数感染COVID-19的人会出现诸如发热、干咳、咽痛、嗅觉减退等典型临床症状。然而也有一部分人群即便感染了新冠病毒,也不会出现任何症状,这些人被称为无症状感染者。为探索这一现象的背后遗传机制中,本项研究使用了29,947名样本的高分辨HLA分型数据,发现人类白细胞抗原(HLA)基因座的变异可能是影响SARS-CoV-2感染者是否出现症状的关键因素。进一步的研究表明,这种遗传关联可能源于预先存在的T细胞免疫。来自携带HLA-B*15:01个体的大流行前样本中的T细胞对SARS-CoV-2 S蛋白衍生的主要免疫原性肽段NQKLIANQF表现出反应性。这些T细胞大多数呈现记忆表型,具有高度多功能性,并与季节性冠状病毒衍生的肽段交叉反应。除此之外,HLA-B15:01–肽段复合物的晶体结构,展示了NQKLIANQF和NQKLIANAF肽段被HLA-B15:01稳定并呈现的相似能力。最后,研究揭示了肽段结构相似性是HLA-B*15:01介导的预先存在免疫的分子基础,这种免疫是由高亲和力的公共T细胞受体的T细胞交叉反应性所决定的。综上所述,这项研究深入阐释了SARS-CoV-2无症状感染背后的遗传和免疫学机制,尤其是HLA-B*15:01基因座的作用。
Abstract:
Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic. Although most global efforts have focused on severe illness in COVID-19, examining asymptomatic infection provides a …
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Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic. Although most global efforts have focused on severe illness in COVID-19, examining asymptomatic infection provides a unique opportunity to consider early immunological features that promote rapid viral clearance. Here, postulating that variation in the human leukocyte antigen (HLA) loci may underly processes mediating asymptomatic infection, we enrolled 29,947 individuals, for whom high-resolution HLA genotyping data were available, in a smartphone-based study designed to track COVID-19 symptoms and outcomes. Our discovery cohort (n = 1,428) comprised unvaccinated individuals who reported a positive test result for SARS-CoV-2. We tested for association of five HLA loci with disease course and identified a strong association between HLA-B*15:01 and asymptomatic infection, observed in two independent cohorts. Suggesting that this genetic association is due to pre-existing T cell immunity, we show that T cells from pre-pandemic samples from individuals carrying HLA-B*15:01 were reactive to the immunodominant SARS-CoV-2 S-derived peptide NQKLIANQF. The majority of the reactive T cells displayed a memory phenotype, were highly polyfunctional and were cross-reactive to a peptide derived from seasonal coronaviruses. The crystal structure of HLA-B*15:01-peptide complexes demonstrates that the peptides NQKLIANQF and NQKLIANAF (from OC43-CoV and HKU1-CoV) share a similar ability to be stabilized and presented by HLA-B*15:01. Finally, we show that the structural similarity of the peptides underpins T cell cross-reactivity of high-affinity public T cell receptors, providing the molecular basis for HLA-B*15:01-mediated pre-existing immunity.
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496.
前进
(2023-11-30 10:22):
#paper GraformerDIR: Graph convolution transformer for deformable
image registration Computers in Biology and Medicine 30 june 2022 https://doi.org/10.1016/j.compbiomed.2022.105799
这是一篇用图卷积来进行图像配准的论文,通过将图卷积变换器(Graformer)层放在
在特征提取网络中,提出了一个基于Graformer的DIR框架,命名为GraformerDIR。Graformer层由Graformer模块和Cheby-shev图卷积模块组成。其中
Graformer模块旨在捕获高质量的长期依赖关系。Cheby-shev图卷积模块用于进一步扩大感受野。GraformerDIR的性能已经在公开的大脑数据集中进行了评估,包括OASIS、LPBA40和MGH10数据集。与VoxelMorph相比,GraformerDIR在DSC方面获得4.6%的性能改进,在平均值方面获得0.055mm的性能改进,同时折叠率更低。
IF:7.000Q1
Computers in biology and medicine,
2022-08.
DOI: 10.1016/j.compbiomed.2022.105799
PMID: 35792472
Abstract:
PURPOSE: Deformable image registration (DIR) plays an important role in assisting disease diagnosis. The emergence of the Transformer enables the DIR framework to extract long-range dependencies, which relieves the limitations …
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PURPOSE: Deformable image registration (DIR) plays an important role in assisting disease diagnosis. The emergence of the Transformer enables the DIR framework to extract long-range dependencies, which relieves the limitations of intrinsic locality caused by convolution operation. However, suffering from the interference of missing or spurious connections, it is a challenging task for Transformer-based methods to capture the high-quality long-range dependencies.METHODS: In this paper, by staking the graph convolution Transformer (Graformer) layer at the bottom of the feature extraction network, we propose a Graformer-based DIR framework, named GraformerDIR. The Graformer layer is consist of the Graformer module and the Cheby-shev graph convolution module. Among them, the Graformer module is designed to capture high-quality long-range dependencies. Cheby-shev graph convolution module is employed to further enlarge the receptive field.RESULTS: The performance and generalizability of GraformerDIR have been evaluated on publicly available brain datasets including the OASIS, LPBA40, and MGH10 datasets. Compared with VoxelMorph, the GraformerDIR has obtained performance improvements of 4.6% in Dice similarity coefficient (DSC) and 0.055 mm in the average symmetric surface distance (ASD) while reducing the non-positive rate of Jacobin determinant (Npr.Jac) index about 60 times on publicly available OASIS dataset. On unseen dataset MGH10, the GraformerDIR has obtained the performance improvements of 4.1% in DSC and 0.084 mm in ASD compared with VoxelMorph, which demonstrates the GraformerDIR with better generalizability. The promising performance on the clinical cardiac dataset ACDC indicates the GraformerDIR is practicable.CONCLUSION: With the advantage of Transformer and graph convolution, the GraformerDIR has obtained comparable performance with the state-of-the-art method VoxelMorph.
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497.
哪有情可长
(2023-11-30 10:03):
#paper Genomic insights into historical improvement of heterotic groups during modern hybrid maize breeding, Nature plants,18 July 2022,doi.org/10.1038/s41477-022-01190-2. 玉米杂交种表现出优越的杂种,是通过跨越属于遗传不同异种群的两个亲本近交系产生的。在这里,本文研究者装了 1,604 个历史上利用属于各种母本异质性组 (FHG) 和父本异质性组 (MHG) 的玉米系,并进行了表型和基因组测序分析。发现 FHG 和 MHG 对不同的农艺性状集经历了收敛和发散的变化。使用全基因组选择扫描和关联分析,确定了大量候选基因,这些基因有助于提高 FHG 和 MHG 的农艺性状。此外,研究人员还观察到FHGs和MHGs在育种时代的遗传分化增加,发现分化基因杂合子水平增加与杂交种杂合子杂合性呈正相关。后续验证了两个选定基因和分化基因的功能,确定其对株高和籽粒大小具有重要的影响。
Genomic insights into historical improvement of heterotic groups during modern hybrid maize breeding
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Abstract:
Single-cross maize hybrids display superior heterosis and are produced from crossing two parental inbred lines belonging to genetically different heterotic groups. Here we assembled 1,604 historically utilized maize inbred lines …
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Single-cross maize hybrids display superior heterosis and are produced from crossing two parental inbred lines belonging to genetically different heterotic groups. Here we assembled 1,604 historically utilized maize inbred lines belonging to various female heterotic groups (FHGs) and male heterotic groups (MHGs), and conducted phenotyping and genomic sequencing analyses. We found that the FHGs and MHGs have undergone both convergent and divergent changes for different sets of agronomic traits. Using genome-wide selection scans and association analyses, we identified a large number of candidate genes that contributed to the improvement of agronomic traits of the FHGs and MHGs. Moreover, we observed increased genetic differentiation between the FHGs and MHGs across the breeding eras, and we found a positive correlation between increasing heterozygosity levels in the differentiated genes and heterosis in hybrids. Furthermore, we validated the function of two selected genes and a differentiated gene. This study provides insights into the genomic basis of modern hybrid maize breeding.
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498.
Jarvi Coa
(2023-11-30 09:39):
#paper DOI : 10.1021/jacs.2c11504 Pub Date : 2023-01-26 Self-Stacking Autocatalytic Molecular Circuit with Minimal Catalytic DNA Assembly
本文提出了一种可扩展的自组装自催化DNNA电路(AAD),它由一个简单而有效的诱导序列反应组成。该系统由一小部分DNA分子序列反应和少量复制触发组成,且反应过程中可生成能够继续催化自身的trigger。通过深层理论模拟和系统实验演示,这些重新生成的trigger效率能够达到预期目标且具有较高特异性,因此可以很容易地改进以达到更有效且具有特征的DNA电路的信号放大。基于其指数级高信号感知性和最小反应组件,这种DNA分子电路大大加快了生物医学诊断和治疗评估的进程。
IF:14.400Q1
Journal of the American Chemical Society,
2023-02-08.
DOI: 10.1021/jacs.2c11504
PMID: 36700894
Abstract:
Isothermal autocatalytic DNA circuits have been proven to be versatile and powerful biocomputing platforms by virtue of their self-sustainable and self-accelerating reaction profiles, yet they are currently constrained by their …
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Isothermal autocatalytic DNA circuits have been proven to be versatile and powerful biocomputing platforms by virtue of their self-sustainable and self-accelerating reaction profiles, yet they are currently constrained by their complicated designs, severe signal leakages, and unclear reaction mechanisms. Herein, we developed a simpler-yet-efficient autocatalytic assembly circuit (AAC) for highly robust bioimaging in live cells and mice. The scalable and sustainable AAC system was composed of a mere catalytic DNA assembly reaction with minimal strand complexity and, upon specific stimulation, could reproduce numerous new triggers to expedite the whole reaction. Through in-depth theoretical simulations and systematic experimental demonstrations, the catalytic efficiency of these reproduced triggers was found to play a vital role in the autocatalytic profile and thus could be facilely improved to achieve more efficient and characteristic autocatalytic signal amplification. Due to its exponentially high signal amplification and minimal reaction components, our self-stacking AAC facilitated the efficient detection of trace biomolecules with low signal leakage, thus providing great clinical diagnosis and therapeutic assessment potential.
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499.
龙海晨
(2023-11-30 01:51):
#paper Janbazacyabar H, van Bergenhenegouwen J, Varasteh S, Garssen J, Folkerts G, Braber S. Repeated exposure of bronchial epithelial cells to particular matter increases allergen-induced cytokine release and permeability. Cytokine. 2022 Jun;154:155878. doi: 10.1016/j.cyto.2022.155878. Epub 2022 Apr 8. PMID: 35405483. 这是一篇研究暴露在颗粒污染物下与过敏的文章。作者构建了一个通有电极的细胞模型。用以模拟检测长期暴露在柴油废气颗粒物环境下细胞的过敏反应。为进一步研究呼吸道在重污染下的过敏,哮喘提供了基础。
Abstract:
Long term particulate matter (PM) exposure has been associated with an increased incidence of respiratory diseases. Here, an in vitro model was developed to study how long term diesel exhaust …
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Long term particulate matter (PM) exposure has been associated with an increased incidence of respiratory diseases. Here, an in vitro model was developed to study how long term diesel exhaust particle (DEP) exposure might predispose to the development of allergic reactions. Airway epithelial (16HBE) cells were exposed to low concentrations of diesel exhaust particle (DEP) for 4 days after which they were challenged with house dust mite (HDM) extract (24 h). Compared to acute exposure (24 h), 4 days DEP exposure to 16HBE cells further reduced the transepithelial electrical resistance (TEER) and increased CXCL-8 release. DEP pre-exposure aggravated HDM-induced loss of TEER, increased tracer flux across the barrier and reduced CLDN-3 expression in these 16HBE cells. HDM-induced cytokine (IL-6, CCL-22, IL-10 and CXCL-8) release was significantly increased after DEP pre-exposure. In the current study an in vitro model with long term PM exposure was presented, which might be helpful for further understanding the interplay between long term PM exposure and allergic responses.
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500.
惊鸿
(2023-11-29 11:58):
#paper DOI : 10.1007/s00417-023-06158-2 Pub Date : 2023-06-30 Comparisons of the protein expressions between high myopia and moderate myopia on the anterior corneal stroma in human
这篇论文的结论为,与中度近视角膜相比,高度近视角膜在前角膜基质上有 36 个 DEP。高度近视眼角膜的角质形成细胞迁移和细胞骨架的结构成分减弱,这可能部分解释了高度近视眼角膜生物力学较低的原因。较低表达的KRT16在高度近视角膜中发挥重要作用。