当前共找到 1453 篇文献分享,本页显示第 921 - 940 篇。
921.
庞庞
(2023-01-31 12:30):
#paper doi:https://doi.org/10.1371/journal.pbio.2007032 Performing group-level functional image analyses based on homologous functional regions mapped in individuals
大脑功能区域的大小、形状、位置和连接模式在个体之间可能存在巨大差异。 作者提出了新的个体化功能分区方法,并证明该方法可以显着改进静息状态功能连接、任务-fMRI 激活和大脑-行为关联的研究。 此外,作者还表明大脑功能区域在大小、位置和连通性方面的个体差异可以提供解释人类行为的信息。
Abstract:
Functional MRI (fMRI) studies have traditionally relied on intersubject normalization based on global brain morphology, which cannot establish proper functional correspondence between subjects due to substantial intersubject variability in functional …
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Functional MRI (fMRI) studies have traditionally relied on intersubject normalization based on global brain morphology, which cannot establish proper functional correspondence between subjects due to substantial intersubject variability in functional organization. Here, we reliably identified a set of discrete, homologous functional regions in individuals to improve intersubject alignment of fMRI data. These functional regions demonstrated marked intersubject variability in size, position, and connectivity. We found that previously reported intersubject variability in functional connectivity maps could be partially explained by variability in size and position of the functional regions. Importantly, individual differences in network topography are associated with individual differences in task-evoked activations, suggesting that these individually specified regions may serve as the "localizer" to improve the alignment of task-fMRI data. We demonstrated that aligning task-fMRI data using the regions derived from resting state fMRI may lead to increased statistical power of task-fMRI analyses. In addition, resting state functional connectivity among these homologous regions is able to capture the idiosyncrasies of subjects and better predict fluid intelligence (gF) than connectivity measures derived from group-level brain atlases. Critically, we showed that not only the connectivity but also the size and position of functional regions are related to human behavior. Collectively, these findings suggest that identifying homologous functional regions across individuals can benefit a wide range of studies in the investigation of connectivity, task activation, and brain-behavior associations.
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922.
LXJ
(2023-01-30 21:35):
#paper doi: 10.1016/j.immuni.2022.11.002 ,B cell expansion hinders the stroma-epithelium regenerative cross talk during mucosal healing,Immunity,2022
促进肠道再生的治疗前景广阔,但确定影响组织再生的细胞机制仍然是一个尚未解决的挑战。为了深入了解粘膜愈合的过程,作者纵向检查了肠道损伤和再生过程中的免疫细胞组成。B细胞是愈合结肠中的主要细胞类型,单细胞RNA测序(scRNA-seq)显示在实验性粘膜愈合过程中IFN诱导的B细胞亚群的扩增,主要位于受损区域并与结肠炎严重程度相关。B细胞耗竭加速了损伤后的恢复,减少了上皮溃疡,并增强了与组织重建相关的基因表达程序。来自上皮和基质室的scRNA-seq结合空间转录组学和多重免疫染色显示,B细胞在粘膜愈合期间减少了基质和上皮细胞之间的相互作用。活化的B细胞破坏了维持类器官生存所需的上皮间质串扰。因此,损伤过程中B细胞的扩张会损害粘膜愈合所需的上皮-基质细胞相互作用,这对IBD的治疗有意义。
Abstract:
Therapeutic promotion of intestinal regeneration holds great promise, but defining the cellular mechanisms that influence tissue regeneration remains an unmet challenge. To gain insight into the process of mucosal healing, …
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Therapeutic promotion of intestinal regeneration holds great promise, but defining the cellular mechanisms that influence tissue regeneration remains an unmet challenge. To gain insight into the process of mucosal healing, we longitudinally examined the immune cell composition during intestinal damage and regeneration. B cells were the dominant cell type in the healing colon, and single-cell RNA sequencing (scRNA-seq) revealed expansion of an IFN-induced B cell subset during experimental mucosal healing that predominantly located in damaged areas and associated with colitis severity. B cell depletion accelerated recovery upon injury, decreased epithelial ulceration, and enhanced gene expression programs associated with tissue remodeling. scRNA-seq from the epithelial and stromal compartments combined with spatial transcriptomics and multiplex immunostaining showed that B cells decreased interactions between stromal and epithelial cells during mucosal healing. Activated B cells disrupted the epithelial-stromal cross talk required for organoid survival. Thus, B cell expansion during injury impairs epithelial-stromal cell interactions required for mucosal healing, with implications for the treatment of IBD.
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923.
李翛然
(2023-01-30 16:03):
#paper doi:https://doi.org/10.1038/s41467-022-35343-w Machine learning models to accelerate the design of polymeric long-acting injectables
2023年第一篇吸引我注意的计算生物学的论文。 这篇文章刚好提到我们最近的一个研究方向,不错不错,说明我司都踏在点子上了。 这篇文章主要是介绍了一种如何通过计算来设计长效药物结构的方法。虽然看内容,里面的计算工具和思想还是AI从业人员不难想到,通过AI学习长效药物的特征,从而预测新的药物结构释放效率。 但是揭示的结论确实和我司考虑的方向一模一样。 人类历史上很多药物都是马马虎虎上市的,有太多可以改进的地方了。 加油2023
Abstract:
Long-acting injectables are considered one of the most promising therapeutic strategies for the treatment of chronic diseases as they can afford improved therapeutic efficacy, safety, and patient compliance. The use …
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Long-acting injectables are considered one of the most promising therapeutic strategies for the treatment of chronic diseases as they can afford improved therapeutic efficacy, safety, and patient compliance. The use of polymer materials in such a drug formulation strategy can offer unparalleled diversity owing to the ability to synthesize materials with a wide range of properties. However, the interplay between multiple parameters, including the physicochemical properties of the drug and polymer, make it very difficult to intuitively predict the performance of these systems. This necessitates the development and characterization of a wide array of formulation candidates through extensive and time-consuming in vitro experimentation. Machine learning is enabling leap-step advances in a number of fields including drug discovery and materials science. The current study takes a critical step towards data-driven drug formulation development with an emphasis on long-acting injectables. Here we show that machine learning algorithms can be used to predict experimental drug release from these advanced drug delivery systems. We also demonstrate that these trained models can be used to guide the design of new long acting injectables. The implementation of the described data-driven approach has the potential to reduce the time and cost associated with drug formulation development.
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924.
张浩彬
(2023-01-30 13:34):
#paper https://doi.org/10.48550/arXiv.2202.01575 COST: CONTRASTIVE LEARNING OF DISENTANGLED SEASONAL-TREND REPRESENTATIONS FOR TIME SERIES FORECASTING
1. 文章认为一个时间序列可由3个部分组成,趋势项+季节项+误差项。我们需要学习的趋势项和季节项
2. 从整体结构上看,对于原始序列通过编码器(TCN)将原始序列映射到隐空间中,之后分别通过两个结构分理出趋势项及季节项分别进行对比学习
a. 对于趋势项来说,对于获得的隐空间表示,输入到自回归专家混合提取器中进行趋势提取,并通过时域进行对比损失学习。时域的对比损失学习参考了Moco进行
b. 对于季节项,用离散傅里叶变换将隐空间映射到频域,频域损失函数定义为波幅和相位的损失。
3. 最终总的损失函数时域+频域的损失函数
4. 基于5个数据和多个基线模型进行对比,包括TS2Vec、TNC,Moco,Informer、LogTrans、TCN等,大部分取得了SOTA的效果
arXiv,
2022.
DOI: 10.48550/arXiv.2202.01575
Abstract:
Deep learning has been actively studied for time series forecasting, and the mainstream paradigm is based on the end-to-end training of neural network architectures, ranging from classical LSTM/RNNs to more …
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Deep learning has been actively studied for time series forecasting, and the mainstream paradigm is based on the end-to-end training of neural network architectures, ranging from classical LSTM/RNNs to more recent TCNs and Transformers. Motivated by the recent success of representation learning in computer vision and natural language processing, we argue that a more promising paradigm for time series forecasting, is to first learn disentangled feature representations, followed by a simple regression fine-tuning step -- we justify such a paradigm from a causal perspective. Following this principle, we propose a new time series representation learning framework for time series forecasting named CoST, which applies contrastive learning methods to learn disentangled seasonal-trend representations. CoST comprises both time domain and frequency domain contrastive losses to learn discriminative trend and seasonal representations, respectively. Extensive experiments on real-world datasets show that CoST consistently outperforms the state-of-the-art methods by a considerable margin, achieving a 21.3% improvement in MSE on multivariate benchmarks. It is also robust to various choices of backbone encoders, as well as downstream regressors. Code is available at this https URL.
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925.
DeDe宝
(2023-01-29 17:31):
#paper https://doi.org/10.1002/hbm.23983 HUMAN BRAIN MAPPING 2018. The retrosplenial cortex: A memory gateway between the cortical default mode network and the medial temporal lobe
默认模式网络 (DMN) 涉及相互作用的皮质区域,包括后扣带皮层 (PCC) 和压后皮质 (RSC),以及皮质下区域,包括内侧颞叶 (MTL)。过去的研究中DMN-MTL的功能连接FC与情景记忆EM表现的关联的静息态研究具有不一致的结果。动物研究表明RSC可以作为促进大脑皮层和皮层下 DMN 之间信息传递的中间层,研究假设RSC对DMN-MTL的功能连接FC与情景记忆EM表现具有中介作用。本研究使用COBRA项目数据集,采集了180名健康老年人(64-68 岁)的EM表现与rfmri,用图论方法对DMN节点进行的进一步分析揭示了RSC 的最高介数中心性,证实了DMN 区域中有很大比例的短路径通过 RSC。
Abstract:
The default mode network (DMN) involves interacting cortical areas, including the posterior cingulate cortex (PCC) and the retrosplenial cortex (RSC), and subcortical areas, including the medial temporal lobe (MTL). The …
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The default mode network (DMN) involves interacting cortical areas, including the posterior cingulate cortex (PCC) and the retrosplenial cortex (RSC), and subcortical areas, including the medial temporal lobe (MTL). The degree of functional connectivity (FC) within the DMN, particularly between MTL and medial-parietal subsystems, relates to episodic memory (EM) processes. However, past resting-state studies investigating the link between posterior DMN-MTL FC and EM performance yielded inconsistent results, possibly reflecting heterogeneity in the degree of connectivity between MTL and specific cortical DMN regions. Animal work suggests that RSC has structural connections to both cortical DMN regions and MTL, and may thus serve as an intermediate layer that facilitates information transfer between cortical and subcortical DMNs. We studied 180 healthy old adults (aged 64-68 years), who underwent comprehensive assessment of EM, along with resting-state fMRI. We found greater FC between MTL and RSC than between MTL and the other cortical DMN regions (e.g., PCC), with the only significant association with EM observed for MTL-RSC FC. Mediational analysis showed that MTL-cortical DMN connectivity increased with RSC as a mediator. Further analysis using a graph-theoretical approach on DMN nodes revealed the highest betweenness centrality for RSC, confirming that a high proportion of short paths among DMN regions pass through RSC. Importantly, the degree of RSC mediation was associated with EM performance, suggesting that individuals with greater mediation have an EM advantage. These findings suggest that RSC forms a critical gateway between MTL and cortical DMN to support EM in older adults.
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926.
白鸟
(2023-01-28 22:01):
#paper https://doi.org/10.1038/s41591-022-02104-7 nature medicine 2022. Impact of the Human Cell Atlas on medicine.
疾病只有在健康样本的参照下才能被充分理解,实现这一愿景需要构建人类所有细胞的综合参考图谱。单细胞图谱有望填补基因、疾病和疗法之间“缺失的一环”。
图谱的意义在于:1.提高我们对疾病的认知,通过识别特定的细胞类型、状态、程序和与疾病相关基因起作用的环境,我们可以从细胞和组织层面了解疾病机制。2.诊断和治疗的应用:单细胞图谱和空间图谱改变我们对不同疾病在细胞和组织层面的理解,为了解诊断学、药物发现和新的治疗途径的发展提供信息。利用这些发现来开发强大的疾病诊断;确定有前途的新药物靶标;预测它们的功效、毒性和耐药机制;从癌症疗法到再生医学方领域授予新的疗法。
总结:人类细胞图谱的使命是形成一个参考图谱,作为了解人类健康以及诊断、监测和治疗疾病的基础。类似于人类基因组计划,基因组计划本身并没有“解决”疾病,但为生物医学的许多领域奠定了重要基础。绘制人类细胞图谱同时也带来了巨大的后期工作和技术挑战,路漫漫兮,但是它对医学的潜力也是巨大的。
Abstract:
Single-cell atlases promise to provide a 'missing link' between genes, diseases and therapies. By identifying the specific cell types, states, programs and contexts where disease-implicated genes act, we will understand …
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Single-cell atlases promise to provide a 'missing link' between genes, diseases and therapies. By identifying the specific cell types, states, programs and contexts where disease-implicated genes act, we will understand the mechanisms of disease at the cellular and tissue levels and can use this understanding to develop powerful disease diagnostics; identify promising new drug targets; predict their efficacy, toxicity and resistance mechanisms; and empower new kinds of therapies, from cancer therapies to regenerative medicine. Here, we lay out a vision for the potential of cell atlases to impact the future of medicine, and describe how advances over the past decade have begun to realize this potential in common complex diseases, infectious diseases (including COVID-19), rare diseases and cancer.
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927.
林海onrush
(2023-01-27 01:30):
#paper, Twist: Sound Reasoning for Purity and Entanglement in Quantum Programs,DOI:
10.48550/arXiv.2205.02287,作者引入了纯度表达式的概念,以在量子程序中对纠缠状态进行推理判断。类似于经典内存的指针,并通过执行被称为门的操作来对它们进行评估。由于纠缠的特殊形式存在,导致量子比特的测量结果是相关的现象,而纠缠可以决定算法的正确性和编程模式的适用性。将纯度表达形式化,可以作为自动推理量子程序中纠缠的核心工具,是指其评价不受量子比特的测量结果影响的表达式。本文主要贡献在于提出了Twist,这是第一种具有类型系统的语言,用于对纯度进行合理推理,使开发者能够使用类型注解来识别纯度表达式。最后证明了Twist可以表达量子算法,捕捉其中的编程错误,并支持一些其他语言不允许的程序。同时产生的运行时验证开销小于3.5%。整体而言,是一项基础且有意义的工作。
arXiv,
2022.
DOI: 10.48550/arXiv.2205.02287
Abstract:
Quantum programming languages enable developers to implement algorithms for quantum computers that promise computational breakthroughs in classically intractable tasks. Programming quantum computers requires awareness of entanglement, the phenomenon in which …
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Quantum programming languages enable developers to implement algorithms for quantum computers that promise computational breakthroughs in classically intractable tasks. Programming quantum computers requires awareness of entanglement, the phenomenon in which measurement outcomes of qubits are correlated. Entanglement can determine the correctness of algorithms and suitability of programming patterns. In this work, we formalize purity as a central tool for automating reasoning about entanglement in quantum programs. A pure expression is one whose evaluation is unaffected by the measurement outcomes of qubits that it does not own, implying freedom from entanglement with any other expression in the computation. We present Twist, the first language that features a type system for sound reasoning about purity. The type system enables the developer to identify pure expressions using type annotations. Twist also features purity assertion operators that state the absence of entanglement in the output of quantum gates. To soundly check these assertions, Twist uses a combination of static analysis and runtime verification. We evaluate Twist's type system and analyses on a benchmark suite of quantum programs in simulation, demonstrating that Twist can express quantum algorithms, catch programming errors in them, and support programs that several languages disallow, while incurring runtime verification overhead of less than 3.5%.
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928.
惊鸿
(2023-01-07 21:44):
#paper DOI : 10.1038/s43587-022-00340-7 Pub Date:2022-12-30Optogenetic rejuvenation of mitochondrial membrane potential extends C. elegans lifespan 线粒体功能障碍在衰老中起着核心作用,但确切的生物学原因仍在确定中。在这里,我们展示了使用光激活质子泵在成年期通过光遗传学增加线粒体膜电位可改善与年龄相关的表型并延长秀丽隐杆线虫的寿命。我们的研究结果提供了直接的因果证据,表明挽救与年龄相关的线粒体膜电位下降足以减缓衰老速度并延长健康寿命和寿命。
Abstract:
Mitochondrial dysfunction plays a central role in aging but the exact biological causes are still being determined. Here, we show that optogenetically increasing mitochondrial membrane potential during adulthood using a …
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Mitochondrial dysfunction plays a central role in aging but the exact biological causes are still being determined. Here, we show that optogenetically increasing mitochondrial membrane potential during adulthood using a light-activated proton pump improves age-associated phenotypes and extends lifespan in . Our findings provide direct causal evidence that rescuing the age-related decline in mitochondrial membrane potential is sufficient to slow the rate of aging and extend healthspan and lifespan.
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929.
徐炳祥
(2023-01-06 22:21):
#paper doi: 10.1038/s41588-022-01223-8 Nature, 2022, Enhancer-promoter interactions and transcription are largely maintained upon acute loss of CTCF, cohesin, WAPL or YY1。染色质空间构象对基因表达的调控模式目前依然是表观遗传学中一个有争议的话题,在本文中,作者快速降解了几个维持与调控染色质空间构象的重要因子(CTCF,cohesin,YY1)并测量了他们对染色质空间构象和基因表达谱的冲击。结果显示降解这些因子主要影响结构性染色质环,对启动子-启动子环或启动子-增强子环的影响有限,降解也不大范围改变基因表达谱。进一步,作者通过活细胞成像技术对YY1的结合动态进行了追踪,论证了YY1与DNA的结合是动态的且大部分YY1处于游离状态。进一步,作者论证了cohesin的敲除影响YY1的结合位点识别效率。本文中以下两个观点是值得注意的:1. 启动子-启动子环/启动子-增强子环与连接TAD边界的结构性染色质环的形成机理/对基因表达谱的影响是不同的;2. Cohesin敲除不仅直接破坏染色质构象,且可通过影响YY1的结合效率发挥间接作用,类似多效性机制也可能出现在其他因子上。
Abstract:
It remains unclear why acute depletion of CTCF (CCCTC-binding factor) and cohesin only marginally affects expression of most genes despite substantially perturbing three-dimensional (3D) genome folding at the level of …
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It remains unclear why acute depletion of CTCF (CCCTC-binding factor) and cohesin only marginally affects expression of most genes despite substantially perturbing three-dimensional (3D) genome folding at the level of domains and structural loops. To address this conundrum, we used high-resolution Micro-C and nascent transcript profiling in mouse embryonic stem cells. We find that enhancer-promoter (E-P) interactions are largely insensitive to acute (3-h) depletion of CTCF, cohesin or WAPL. YY1 has been proposed as a structural regulator of E-P loops, but acute YY1 depletion also had minimal effects on E-P loops, transcription and 3D genome folding. Strikingly, live-cell, single-molecule imaging revealed that cohesin depletion reduced transcription factor (TF) binding to chromatin. Thus, although CTCF, cohesin, WAPL or YY1 is not required for the short-term maintenance of most E-P interactions and gene expression, our results suggest that cohesin may facilitate TFs to search for and bind their targets more efficiently.
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930.
张德祥
(2023-01-06 18:42):
#paper
https://doi.org/10.48550/arXiv.2212.12393
A-NeSI: A Scalable Approximate Method for Probabilistic Neurosymbolic Inference
这篇论文受GFlownet启发,首次在MNIST ADD的训练上达到了 15位数的加法训练,人造算数天才指日可待。结合神经网络和符号计算 。
arXiv,
2022.
DOI: 10.48550/arXiv.2212.12393
Abstract:
We study the problem of combining neural networks with symbolic reasoning. Recently introduced frameworks for Probabilistic Neurosymbolic Learning (PNL), such as DeepProbLog, perform exponential-time exact inference, limiting the scalability of …
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We study the problem of combining neural networks with symbolic reasoning. Recently introduced frameworks for Probabilistic Neurosymbolic Learning (PNL), such as DeepProbLog, perform exponential-time exact inference, limiting the scalability of PNL solutions. We introduce Approximate Neurosymbolic Inference (A-NeSI): a new framework for PNL that uses neural networks for scalable approximate inference. A-NeSI 1) performs approximate inference in polynomial time without changing the semantics of probabilistic logics; 2) is trained using data generated by the background knowledge; 3) can generate symbolic explanations of predictions; and 4) can guarantee the satisfaction of logical constraints at test time, which is vital in safety-critical applications. Our experiments show that A-NeSI is the first end-to-end method to scale the Multi-digit MNISTAdd benchmark to sums of 15 MNIST digits, up from 4 in competing systems. Finally, our experiments show that A-NeSI achieves explainability and safety without a penalty in performance.
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931.
张德祥
(2023-01-03 19:36):
#paper https://doi.org/10.24963/ijcai.2020/243 NeurASP: Embracing Neural Networks into Answer Set Programming 通过将神经网络输出视为答案集程序中原子事实的概率分布,
NeurASP 提供了一种简单有效的方法来集成子神经网络和符号计算。
推理可 以帮助识别违反语义约束的感知错误,这反过来可以使感知更加稳健。例如,
用于对象检测的神经网络可能会返回一个边界框及其分类“汽车”,但可 能不清楚它是真车还是玩具车。可以通过应用关于与周围物体的关系的推 理和使用常识知识来进行区分。或者当不清楚附着在汽车上的圆形物体是 轮子还是甜甜圈时,推理者可以根据常识得出结论,它更有可能是轮子。
Abstract:
We present NeurASP, a simple extension of answer set programs by embracing neural networks. By treating the neural network output as the probability distribution over atomic facts in answer set …
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We present NeurASP, a simple extension of answer set programs by embracing neural networks. By treating the neural network output as the probability distribution over atomic facts in answer set programs, NeurASP provides a simple and effective way to integrate sub-symbolic and symbolic computation. We demonstrate how NeurASP can make use of a pre-trained neural network in symbolic computation and how it can improve the neural network's perception result by applying symbolic reasoning in answer set programming. Also, NeurASP can make use of ASP rules to train a neural network better so that a neural network not only learns from implicit correlations from the data but also from the explicit complex semantic constraints expressed by the rules.
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932.
洪媛媛
(2023-01-03 17:45):
#paper https://doi.org/10.1186/s13073-022-01141-8. Genome Medicine (2022) 14:138. CRAG: de novo characterization of cell-free DNA fragmentation hotspots in plasma whole-genome sequencing. 该研究基于低深度全基因组测序(~1X),使用IFS(整合cfDNA覆盖度和片段大小)和CRAG算法(概率模型分析和背景噪音的区分度)挖掘cfDNA片段化热点区域,发现这些热点区域集中在开发染色质区,利用这些热点区域可以进行癌症的早筛和溯源。在训练集、验证集和独立测试集的AUC表现都不错。
Abstract:
The fine-scale cell-free DNA fragmentation patterns in early-stage cancers are poorly understood. We developed a de novo approach to characterize the cell-free DNA fragmentation hotspots from plasma whole-genome sequencing. Hotspots …
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The fine-scale cell-free DNA fragmentation patterns in early-stage cancers are poorly understood. We developed a de novo approach to characterize the cell-free DNA fragmentation hotspots from plasma whole-genome sequencing. Hotspots are enriched in open chromatin regions, and, interestingly, 3'end of transposons. Hotspots showed global hypo-fragmentation in early-stage liver cancers and are associated with genes involved in the initiation of hepatocellular carcinoma and associated with cancer stem cells. The hotspots varied across multiple early-stage cancers and demonstrated high performance for the diagnosis and identification of tissue-of-origin in early-stage cancers. We further validated the performance with a small number of independent case-control-matched early-stage cancer samples.
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933.
龙海晨
(2023-01-02 13:45):
#paper Rosen D B, Murphy E A, Gejman R S, et al. Cytokine response over the course of COVID-19 infection in pregnant women[J]. Cytokine, 2022, 154: 155894.
PMID: 35490452 PMCID: PMC9035355 DOI: 10.1016/j.cyto.2022.155894
这是研究新冠的文章。发表于2022年。样本是2020年3月到4月纽约市医院的。说明一下,那时候的新冠还不是现在低毒的奥密克戎,是最早的新冠病毒。文章研究的是妊娠期孕妇感染新冠后的血清情况。还有针对相应的细胞因子的治疗。回想2020年初新闻上自媒体上好多是在新冠上黑美国。其实公共防疫各国国情不同。美国的情况把人关房子里老百姓不答应。但对于高精尖层面的研究,2020年3月的时候咱们的核酸检测都没普及。美国治疗方法都到了对应不同人群和不同细胞因子的研究。文章对比分析了新冠阴性和阳性的孕妇细胞因子的水平。以及阳性孕妇不同感染时期各种细胞因子的水平。发现晚期妊娠妇女的细胞因子谱随感染的时间进程而变化,并与临床严重程度相关。
Abstract:
OBJECTIVE: To study how severity and progression of coronavirus disease (COVID-19) affect cytokine profiles in pregnant women.MATERIALS AND METHODS: 69 third-trimester, pregnant women were tested for COVID-19 infection and SARS-CoV-2 …
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OBJECTIVE: To study how severity and progression of coronavirus disease (COVID-19) affect cytokine profiles in pregnant women.MATERIALS AND METHODS: 69 third-trimester, pregnant women were tested for COVID-19 infection and SARS-CoV-2 specific IgM and IgG antibodies. Patients were stratified according to SARS-CoV-2 Reverse Transcriptase-PCR (RT-PCR) status and serology (IgM and IgG) status. Cytokines G-CSF, HGF, IL-18, IL-1Ra, IL-2Ra, IL-8, and IP-10 were measured via ELISA. Retrospective chart review for COVID-19 symptoms and patient vitals was conducted, and cytokine levels were compared between SARS-CoV-2 positive and negative cohorts, by seronegative and seropositive infection, by time course since onset of infection, and according to NIH defined clinical severity.RESULTS: IL-18, IL-1Ra, and IP-10 increased in the 44 RT-PCR positive pregnant women compared to the 25 RT-PCR negative pregnant controls. Elevated cytokine levels were found in early infections, defined by positive RT-PCR and seronegative status, and higher cytokine levels were also associated with more severe disease. By IgM seroconversion, IL-8 and IP-10 returned to levels seen in uninfected patients, while IL-18 levels remained significantly elevated.CONCLUSION: Cytokine profiles of third-trimester pregnant women vary with the time course of infection and are correlated with clinical severity.
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934.
颜林林
(2023-01-01 22:47):
#paper doi:10.1186/s13059-022-02816-6 Genome Biology, 2022, Structural variant analysis of a cancer reference cell line sample using multiple sequencing technologies. 结构变异(SV)检测一直是基因组研究中充满挑战的一项工作。本文来自SEQC2(Sequencing Quality Control Phase 2)consortium。通过来自同一捐献者的乳腺癌组织及对照样本(外周血白细胞),分别构建了细胞系,作为研究材料。分别使用Illumina短读长测序、10x linked-reads测序、PacBio 和 Nanopore 长读长测序,以及 Hi-C测序,由此整合并最终鉴定出1788个SV。之后,又使用PCR方法、芯片方法、Bionano光学图谱、RNA-seq鉴别融合断点等独立的技术方法,对其中一部分结果进行验证,并评估了各技术平台对SV鉴定的性能。文章最终输出了一套SV参考集合,可用于各类SV方法的基准评估。
Abstract:
Abstract Background The cancer genome is commonly altered with thousands of structural rearrangements including insertions, deletions, translocation, inversions, duplications, and copy number variations. Thus, structural variant (SV) characterization plays a …
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Abstract Background The cancer genome is commonly altered with thousands of structural rearrangements including insertions, deletions, translocation, inversions, duplications, and copy number variations. Thus, structural variant (SV) characterization plays a paramount role in cancer target identification, oncology diagnostics, and personalized medicine. As part of the SEQC2 Consortium effort, the present study established and evaluated a consensus SV call set using a breast cancer reference cell line and matched normal control derived from the same donor, which were used in our companion benchmarking studies as reference samples. Results We systematically investigated somatic SVs in the reference cancer cell line by comparing to a matched normal cell line using multiple NGS platforms including Illumina short-read, 10X Genomics linked reads, PacBio long reads, Oxford Nanopore long reads, and high-throughput chromosome conformation capture (Hi-C). We established a consensus SV call set of a total of 1788 SVs including 717 deletions, 230 duplications, 551 insertions, 133 inversions, 146 translocations, and 11 breakends for the reference cancer cell line. To independently evaluate and cross-validate the accuracy of our consensus SV call set, we used orthogonal methods including PCR-based validation, Affymetrix arrays, Bionano optical mapping, and identification of fusion genes detected from RNA-seq. We evaluated the strengths and weaknesses of each NGS technology for SV determination, and our findings provide an actionable guide to improve cancer genome SV detection sensitivity and accuracy. Conclusions A high-confidence consensus SV call set was established for the reference cancer cell line. A large subset of the variants identified was validated by multiple orthogonal methods.
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935.
cellsarts
(2023-01-01 00:01):
#paper 古生菌信号肽酶DOI 10.1099/mic.0.2006/003087-0;Microbiology (2007), 153, 305–314
古生菌构成了生命的第三个领域,不同于
细菌和真核生物。最初被认为只生活在极端环境中,古细菌
物种自此被发现种类繁多,种类繁多栖息地,它们在生态系统中扮演着重要的角色
。信号肽酶是蛋白质分泌途径中的重要酶。在古生菌中,I型信号
肽酶,负责从大部分分泌的信号肽中切割分泌信号肽
蛋白质和类前肽肽酶信号肽酶负责处理信号肽
像前鞭毛蛋白和各种糖结合蛋白一样的前鞭毛蛋白
识别。此外,古菌的信号肽肽酶,负责信号的降解。这些酶似乎
具有真核和细菌的镶嵌特征,同时也具有独特的古菌
特征。综述总结了关于这些酶的最新知识,
包括它们的细胞功能、催化机制以及在其中的分布和保存
古细菌物种。将这些酶与它们的细菌酶和真核酶进行比较
对应物和独特的古菌特征突出。
Abstract:
Signal peptidases are vital enzymes in the protein secretion pathway. In Archaea, type I signal peptidase, responsible for the cleavage of secretory signal peptides from the majority of secreted proteins, …
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Signal peptidases are vital enzymes in the protein secretion pathway. In Archaea, type I signal peptidase, responsible for the cleavage of secretory signal peptides from the majority of secreted proteins, and prepilin peptidase-like signal peptidase, responsible for processing signal peptides from prepilin-like proteins like the preflagellins and various sugar-binding proteins, have been identified. In addition, the archaeal signal peptide peptidase, responsible for degradation of signal peptides after their removal from precursor proteins, has been characterized. These enzymes seem to have a mosaic of eukaryal and bacterial characteristics, and also possess unique archaeal traits. In this review, the most current knowledge with regard to these enzymes is summarized, including their cellular function, catalytic mechanism and distribution and conservation among archaeal species. Comparisons are drawn of these enzymes to their bacterial and eukaryal counterparts, and unique archaeal features highlighted.
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936.
小W
(2023-01-01 00:00):
#paper doi: 10.1016/j.cell.2022.11.016. Epub 2022 Dec 13.
Engineered cell entry links receptor biology with single-cell genomics
1.本文开发了一个模块化病毒展示和递送平台(ENTER),通过向靶细胞中递送配体,以解码细胞间配体-受体相互作用,并将配体-受体的相互作用与细胞状态联系起来,可以系统地对TCR-pMHC、抗体抗原、共刺激配体受体和BCR在内的相互作用进行展示。pMHC结果显示该病毒递送平台比mhc四聚体检测抗原特异性T细胞更敏感,在添加高滴度病毒(40 ng p24)时,ENTER能够检测到低至10.8 mM的TCR亲和力。ENTER能够通过抗原特异性递送自杀基因在T或B细胞池中选择性地耗尽一个T或B淋巴细胞克隆,或递送对抗细胞死亡受体使抗原特异性T细胞选择性存活,其可能在筛选免疫原性抗原或精英TCR,用于疫苗开发或癌症免疫治疗的合理设计;筛选靶向病毒抗原的BCR,促进治疗性抗体的开发;恢复耗竭的抗肿瘤T细;避免免疫相关的不良事件;杀死自身反应性T细胞或B细胞以治疗自身免疫疾病等方向发挥作用。2.ENTER平台与单细胞RNA-seq结合开发了ENTER-seq,捕获每个液滴中病毒RNA上的MHC肽信息,绘制TCR库和同源HLA抗原肽的相互作用。
Abstract:
Cells communicate with each other via receptor-ligand interactions. Here, we describe lentiviral-mediated cell entry by engineered receptor-ligand interaction (ENTER) to display ligand proteins, deliver payloads, and record receptor specificity. We …
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Cells communicate with each other via receptor-ligand interactions. Here, we describe lentiviral-mediated cell entry by engineered receptor-ligand interaction (ENTER) to display ligand proteins, deliver payloads, and record receptor specificity. We optimize ENTER to decode interactions between T cell receptor (TCR)-MHC peptides, antibody-antigen, and other receptor-ligand pairs. A viral presentation strategy allows ENTER to capture interactions between B cell receptor and any antigen. We engineer ENTER to deliver genetic payloads to antigen-specific T or B cells to selectively modulate cellular behavior in mixed populations. Single-cell readout of ENTER by RNA sequencing (ENTER-seq) enables multiplexed enumeration of antigen specificities, TCR clonality, cell type, and states of individual T cells. ENTER-seq of CMV-seropositive patient blood samples reveals the viral epitopes that drive effector memory T cell differentiation and inter-clonal vs. intra-clonal phenotypic diversity targeting the same epitope. ENTER technology enables systematic discovery of receptor specificity, linkage to cell fates, and antigen-specific cargo delivery.
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937.
王昊
(2022-12-31 23:57):
#paper https://arxiv.org/abs/2111.08687v2 Jing Shao, Siyu Chen, Yangguang Li, et al. 2021. INTERN: A New Learning Paradigm Towards General Vision.
视觉基础模型的论文。“书生”(INTERN),旨在系统化解决当下人工智能视觉领域中存在的任务通用、场景泛化和数据效率等一系列瓶颈问题。“书生”由七大模块组成,包括通用视觉数据系统、通用视觉网络结构、通用视觉评测基准三个基础设施模块,以及区分上下游的四个训练阶段模块。多个阶段中学习到了很强的泛化能力。其可以在26个数据集上实现CV中的四类任务,仅使用10%的训练数据进行微调,性能便优于全套数据训练的对应模型。
arXiv,
2021.
DOI: 10.48550/arXiv.2111.08687
Abstract:
Enormous waves of technological innovations over the past several years, marked by the advances in AI technologies, are profoundly reshaping the industry and the society. However, down the road, a …
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Enormous waves of technological innovations over the past several years, marked by the advances in AI technologies, are profoundly reshaping the industry and the society. However, down the road, a key challenge awaits us, that is, our capability of meeting rapidly-growing scenario-specific demands is severely limited by the cost of acquiring a commensurate amount of training data. This difficult situation is in essence due to limitations of the mainstream learning paradigm: we need to train a new model for each new scenario, based on a large quantity of well-annotated data and commonly from scratch. In tackling this fundamental problem, we move beyond and develop a new learning paradigm named INTERN. By learning with supervisory signals from multiple sources in multiple stages, the model being trained will develop strong generalizability. We evaluate our model on 26 well-known datasets that cover four categories of tasks in computer vision. In most cases, our models, adapted with only 10% of the training data in the target domain, outperform the counterparts trained with the full set of data, often by a significant margin. This is an important step towards a promising prospect where such a model with general vision capability can dramatically reduce our reliance on data, thus expediting the adoption of AI technologies. Furthermore, revolving around our new paradigm, we also introduce a new data system, a new architecture, and a new benchmark, which, together, form a general vision ecosystem to support its future development in an open and inclusive manner. See project website at this https URL .
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938.
Ricardo
(2022-12-31 23:50):
#paper http://dx.doi.org/10.1016/j.media.2015.04.005
Construction of 4D high-definition cortical surface atlases of infants: Methods and applications 在神经影像学中,皮层表面图谱在空间归一化、分析、可视化以及个体和不同研究结果的比较中发挥着重要作用。然而,现有的为成人创建的皮层表面图谱并不适合出生后头两年的婴儿大脑,这是出生后高度折叠的大脑皮层结构和功能发育最活跃的时期。因此非常需要婴儿时期的大脑皮层表面的时空图谱集,但目前仍缺乏精细的早期动态脑发育图谱。为了弥补这一重大差距,作者利用团队开发的婴儿皮层表面分析计算管道和自己获得的纵向MRI数据集,基于35名健康婴儿的202个系列MRI扫描,构建了第一个时空(4D)高清皮层表面地图集,用于七个时间点的动态发育研究,包括1、3、6、9、12、18和24个月龄。
Abstract:
In neuroimaging, cortical surface atlases play a fundamental role for spatial normalization, analysis, visualization, and comparison of results across individuals and different studies. However, existing cortical surface atlases created for …
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In neuroimaging, cortical surface atlases play a fundamental role for spatial normalization, analysis, visualization, and comparison of results across individuals and different studies. However, existing cortical surface atlases created for adults are not suitable for infant brains during the first two postnatal years, which is the most dynamic period of postnatal structural and functional development of the highly-folded cerebral cortex. Therefore, spatiotemporal cortical surface atlases for infant brains are highly desired yet still lacking for accurate mapping of early dynamic brain development. To bridge this significant gap, leveraging our infant-dedicated computational pipeline for cortical surface-based analysis and the unique longitudinal infant MRI dataset acquired in our research center, in this paper, we construct the first spatiotemporal (4D) high-definition cortical surface atlases for the dynamic developing infant cortical structures at seven time points, including 1, 3, 6, 9, 12, 18, and 24 months of age, based on 202 serial MRI scans from 35 healthy infants. For this purpose, we develop a novel method to ensure the longitudinal consistency and unbiasedness to any specific subject and age in our 4D infant cortical surface atlases. Specifically, we first compute the within-subject mean cortical folding by unbiased groupwise registration of longitudinal cortical surfaces of each infant. Then we establish longitudinally-consistent and unbiased inter-subject cortical correspondences by groupwise registration of the geometric features of within-subject mean cortical folding across all infants. Our 4D surface atlases capture both longitudinally-consistent dynamic mean shape changes and the individual variability of cortical folding during early brain development. Experimental results on two independent infant MRI datasets show that using our 4D infant cortical surface atlases as templates leads to significantly improved accuracy for spatial normalization of cortical surfaces across infant individuals, in comparison to the infant surface atlases constructed without longitudinal consistency and also the FreeSurfer adult surface atlas. Moreover, based on our 4D infant surface atlases, for the first time, we reveal the spatially-detailed, region-specific correlation patterns of the dynamic cortical developmental trajectories between different cortical regions during early brain development.
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939.
na na na
(2022-12-31 23:50):
#paper,Feature specific quantile normalization enables cross-platform classification of molecular subtypes using gene expression data(2018),DOI:10.1093/bioinformatics/bty026.
分享一篇算法工具类的文章,FSQN(feature specific quantile normalization);该方法主要是处理了 RNA-seq平台 转录组测序数据 和 芯片平台转录组测序数据的标准化问题。这个问题在做公共数据分析的时候尤其重要,通常的办法例如取log2,z-score以及用中位数做矫正等方法虽然可以在一定程度行把数据分布拉到一个区间上,但起分布依然是不一致的,导致在做机器学习建模的时候往往跨平台效果较差,该文章讨论了不同平台间批次产生的原因,并从应用角度入手,不仅比较了现有方法的劣势,也推出了FSQN的方法,该方法在测试数据集上,基于常见的分类器模型,实现了RNA-seq平台 98%的准确度和芯片平台97%准确度。还方法作者提供了R包:https://github.com/jenniferfranks/FSQN。我做过测试,通过PCA可以看到去批次效果较好,但未能实现文章中机器学习模型的高准确度,因此平台间数据的去批次方法和机器学习跨平台使用依然是一个可研究的方向,扩展思维的话,在RNA-seq和Nanostrign之间,RNA-seq和单细胞测序之间,芯片和Nanostrign之间都可以从数据矫正的角度出发去开发去批次的工具。
Abstract:
Motivation: Molecular subtypes of cancers and autoimmune disease, defined by transcriptomic profiling, have provided insight into disease pathogenesis, molecular heterogeneity and therapeutic responses. However, technical biases inherent to different gene …
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Motivation: Molecular subtypes of cancers and autoimmune disease, defined by transcriptomic profiling, have provided insight into disease pathogenesis, molecular heterogeneity and therapeutic responses. However, technical biases inherent to different gene expression profiling platforms present a unique problem when analyzing data generated from different studies. Currently, there is a lack of effective methods designed to eliminate platform-based bias. We present a method to normalize and classify RNA-seq data using machine learning classifiers trained on DNA microarray data and molecular subtypes in two datasets: breast invasive carcinoma (BRCA) and colorectal cancer (CRC).Results: Multiple analyses show that feature specific quantile normalization (FSQN) successfully removes platform-based bias from RNA-seq data, regardless of feature scaling or machine learning algorithm. We achieve up to 98% accuracy for BRCA data and 97% accuracy for CRC data in assigning molecular subtypes to RNA-seq data normalized using FSQN and a support vector machine trained exclusively on DNA microarray data. We find that maximum accuracy was achieved when normalizing RNA-seq datasets that contain at least 25 samples. FSQN allows comparison of RNA-seq data to existing DNA microarray datasets. Using these techniques, we can successfully leverage information from existing gene expression data in new analyses despite different platforms used for gene expression profiling.Availability and implementation: FSQN has been submitted as an R package to CRAN. All code used for this study is available on Github (https://github.com/jenniferfranks/FSQN).Contact: michael.l.whitfield@dartmouth.edu.Supplementary information: Supplementary data are available at Bioinformatics online.
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940.
Arwen
(2022-12-31 23:45):
#paper https://doi.org/10.1038/s41380-022-01924-w
Inflammation and cognition in severe mental illness: patterns of covariation and subgroups
免疫/炎症通路失调与认知障碍之间的潜在关系已在严重精神疾病 (SMI) 中提出,例如精神分裂症和双相谱系障碍。 然而,外周炎症/免疫相关标志物与认知领域之间的多变量关系尚不清楚,许多研究并未考虑认知功能和炎症/免疫状态的个体差异。
本研究旨在调查炎症/免疫相关标记物与认知域之间的协方差模式,并进一步阐明大型 SMI 和健康对照 (HC) 队列中的异质性 (SZ = 343, BD = 289, HC = 770)。 应用典型相关分析 (CCA) 来识别综合选择的认知域和炎症/免疫标记之间的最大协变模式。 发现,较差的语言学习和精神运动处理速度与更高水平的白细胞介素 18 系统细胞因子和 β 防御素 2 相关,反映出先天免疫激活增强,与 HC 相比,SMI 中的这种模式增强。 对 CCA 识别的协方差模式应用层次聚类揭示了一个以 HC 为主(24% SZ、45% BD、74% HC)的高认知-低免疫失调亚组和一个主要由 SMI 患者组成的低认知-高免疫失调亚组( 76% SZ,55% BD,26% HC)。 这些亚组在智商、受教育年限、年龄、CRP、BMI(所有组)、功能水平、症状和抗精神病药的限定日剂量 (DDD)(SMI 队列)方面存在差异。
研究结果表明:在一部分患有严重精神疾病的个体中,认知障碍与先天免疫失调之间存在联系。
研究启发:多变量方法与异质性思想的结合可借鉴
Abstract:
A potential relationship between dysregulation of immune/inflammatory pathways and cognitive impairment has been suggested in severe mental illnesses (SMI), such as schizophrenia (SZ) and bipolar (BD) spectrum disorders. However, multivariate …
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A potential relationship between dysregulation of immune/inflammatory pathways and cognitive impairment has been suggested in severe mental illnesses (SMI), such as schizophrenia (SZ) and bipolar (BD) spectrum disorders. However, multivariate relationships between peripheral inflammatory/immune-related markers and cognitive domains are unclear, and many studies do not account for inter-individual variance in both cognitive functioning and inflammatory/immune status. This study aimed to investigate covariance patterns between inflammatory/immune-related markers and cognitive domains and further elucidate heterogeneity in a large SMI and healthy control (HC) cohort (SZ = 343, BD = 289, HC = 770). We applied canonical correlation analysis (CCA) to identify modes of maximum covariation between a comprehensive selection of cognitive domains and inflammatory/immune markers. We found that poor verbal learning and psychomotor processing speed was associated with higher levels of interleukin-18 system cytokines and beta defensin 2, reflecting enhanced activation of innate immunity, a pattern augmented in SMI compared to HC. Applying hierarchical clustering on covariance patterns identified by the CCA revealed a high cognition-low immune dysregulation subgroup with predominantly HC (24% SZ, 45% BD, 74% HC) and a low cognition-high immune dysregulation subgroup predominantly consisting of SMI patients (76% SZ, 55% BD, 26% HC). These subgroups differed in IQ, years of education, age, CRP, BMI (all groups), level of functioning, symptoms and defined daily dose (DDD) of antipsychotics (SMI cohort). Our findings suggest a link between cognitive impairment and innate immune dysregulation in a subset of individuals with severe mental illness.
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