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781.
哪有情可长
(2023-01-31 19:16):
#paper # De novo genome assembly and analyses of 12 founder inbred lines provide insights into maize heterosis, Nature Genetics,16 January 2023,doi.org/10.1038/s41588-022-01283-w.玉米是三大粮食作物中杂种优势研究最多的物种,只是证明玉米存在杂种优势,但是关于对不同的育种目标对父母本的选择还没有文章说明,所以作者想对现在的骨干亲本组装想鉴定发现前人杂种优势形成的缘由。作者首先通过进化树分析对现在玉米常用的350自交系进行分析,对进化树每个分支上选取目前世界范围内广泛使用的12个骨干自交系,通过三代测序组装高质量基因组,同时结合玉米中之前已经发表的B73和Mo17基因组,构建了温带玉米核心育种种质泛基因组。作者对14个材料之间进行基因组比较分析发现存在广泛的遗传变异,通过对对玉米中现在 常用的自交系350份对花期、穗行数、穗粒数等表型进行鉴定和关键基因的单倍型分析,发现结构变异对杂种有事的形成和表型分化具有重要的贡献。通过对131份自交系雌穗的转录组数据分析,鉴定到306,868个调控基因表达的顺式eQTL,并挖掘到了一批调控玉米雄穗分枝数、穗位高及穗腐病抗性相关的候选基因及其关键结构变异;进一步结合14 个自交系的双列杂交群体 (91个F1)及3个环境的表型数据分析发现,玉米杂种优势与双亲基因组间结构变异的数量呈显著正相关,而与双亲基因组间共线性程度呈显著负相关,说明玉米杂种优势与双亲在全基因组水平的遗传互补性密切相关,为杂种优势的遗传互补模型提供了强有力的支持。同时结合遗传和分子生物学证据,挖掘到了ZmACO2 (编码一个乙烯合成酶)和ARGOS1 (ZAR1, 编码一个乙烯信号传导相关蛋白) 2个关键产量杂种优势位点,证明了其以超显性效应发挥作用。
Abstract:
Hybrid maize displays superior heterosis and contributes over 30% of total worldwide cereal production. However, the molecular mechanisms of heterosis remain obscure. Here we show that structural variants (SVs) between …
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Hybrid maize displays superior heterosis and contributes over 30% of total worldwide cereal production. However, the molecular mechanisms of heterosis remain obscure. Here we show that structural variants (SVs) between the parental lines have a predominant role underpinning maize heterosis. De novo assembly and analyses of 12 maize founder inbred lines (FILs) reveal abundant genetic variations among these FILs and, through expression quantitative trait loci and association analyses, we identify several SVs contributing to genomic and phenotypic differentiations of various heterotic groups. Using a set of 91 diallel-cross F hybrids, we found strong positive correlations between better-parent heterosis of the F hybrids and the numbers of SVs between the parental lines, providing concrete genomic support for a prevalent role of genetic complementation underlying heterosis. Further, we document evidence that SVs in both ZAR1 and ZmACO2 contribute to yield heterosis in an overdominance fashion. Our results should promote genomics-based breeding of hybrid maize.
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782.
Vincent
(2023-01-31 14:45):
#paper doi:https://doi.org/10.1186/s13059-021-02388-x Gene set enrichment analysis for genome-wide DNA methylation data. Genome Biology 2021. 甲基化芯片相比WGBS而言所需要的费用更低,其被广泛用于DNA甲基化的测量。过去的研究主要着重于甲基化芯片的数据处理和甲基化差异分析上,对基因集富集分析的关注较少,这篇文章提出了一个基于甲基化差异分析结果的的基因集富集分析:GOmeth(适用于探针层面的差异分析数据)和GOregion(适用于区域层面的差异分析数据)。具体来说,CpG位点在基因组上的分布并不是均匀的,不同基因附近的CpG位点数量并不一样多,这导致依照甲基化差异分析选择相邻基因做富集分析时,CpG较多的基因更容易被选中,给富集分析带来偏差。同时同一个CpG位点可能位于好几个基因附近(大概占总数的8%),导致那些差异甲基化的基因并不是独立获得的,也会给基因集富集分析带来偏差。这篇文章的方案调整了富集分析中CpG位点的权重和统计分布,通过数据仿真和重复抽样的方法探究了上述两种偏差对基因集富集分析的影响,同时也验证了提出的方法能够很好的控制错误发现率(FDR),同时能给更加biological meaningful的通路分析结果
Abstract:
DNA methylation is one of the most commonly studied epigenetic marks, due to its role in disease and development. Illumina methylation arrays have been extensively used to measure methylation across …
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DNA methylation is one of the most commonly studied epigenetic marks, due to its role in disease and development. Illumina methylation arrays have been extensively used to measure methylation across the human genome. Methylation array analysis has primarily focused on preprocessing, normalization, and identification of differentially methylated CpGs and regions. GOmeth and GOregion are new methods for performing unbiased gene set testing following differential methylation analysis. Benchmarking analyses demonstrate GOmeth outperforms other approaches, and GOregion is the first method for gene set testing of differentially methylated regions. Both methods are publicly available in the missMethyl Bioconductor R package.
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783.
负负
(2023-01-31 14:43):
#paper doi: 10.1016/j.neuroimage.2016.09.046. BrainNetCNN: Convolutional neural networks for brain networks; towards predicting neurodevelopment. NeuroImage.2017. 功能连接矩阵(FCS)是介于功能连接(FC)和脑网络(FCN)之间的特殊的度量指标,在基于FCS的表征学习过程中,如果直接使用线性统计学模型会忽略其中的网络连接拓扑属性,如果使用图卷积等深度学习方法也存在很多限制(例如,FCS是一个完全图,每个节点都与其他节点存在连接;直接使用全连接的话模型又会很庞大)。针对这个问题,作者提出了适用于FCS的深度学习网络——BrainNetCNN,该网络的卷积包括三个部分:
1、 E2E卷积。FCS中连接两节点的每个功能连接受到这两个节点的profile的影响,该卷积核用来学习这两个节点的profile的特征。
2、 E2N卷积。该卷积核将单个节点的profile的特征降维至单个节点的特征,类似于传统CNN中的池化过程。
3、 N2G卷积。类似于E2N,将上一步降维后的所有节点的特征进一步降维至“图”的特征,此时原始FCS已降至一维
BrainNetCNN在认知评分预测等任务取得了不错的效果,并且进一步发现了在这一过程中起到重要作用的FCS子模块,例如右额中回与右侧中央前回之间的连接对运动、认知评分预测和年龄预测过程起到了重要作用。
Abstract:
We propose BrainNetCNN, a convolutional neural network (CNN) framework to predict clinical neurodevelopmental outcomes from brain networks. In contrast to the spatially local convolutions done in traditional image-based CNNs, our …
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We propose BrainNetCNN, a convolutional neural network (CNN) framework to predict clinical neurodevelopmental outcomes from brain networks. In contrast to the spatially local convolutions done in traditional image-based CNNs, our BrainNetCNN is composed of novel edge-to-edge, edge-to-node and node-to-graph convolutional filters that leverage the topological locality of structural brain networks. We apply the BrainNetCNN framework to predict cognitive and motor developmental outcome scores from structural brain networks of infants born preterm. Diffusion tensor images (DTI) of preterm infants, acquired between 27 and 46 weeks gestational age, were used to construct a dataset of structural brain connectivity networks. We first demonstrate the predictive capabilities of BrainNetCNN on synthetic phantom networks with simulated injury patterns and added noise. BrainNetCNN outperforms a fully connected neural-network with the same number of model parameters on both phantoms with focal and diffuse injury patterns. We then apply our method to the task of joint prediction of Bayley-III cognitive and motor scores, assessed at 18 months of age, adjusted for prematurity. We show that our BrainNetCNN framework outperforms a variety of other methods on the same data. Furthermore, BrainNetCNN is able to identify an infant's postmenstrual age to within about 2 weeks. Finally, we explore the high-level features learned by BrainNetCNN by visualizing the importance of each connection in the brain with respect to predicting the outcome scores. These findings are then discussed in the context of the anatomy and function of the developing preterm infant brain.
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784.
小年
(2023-01-31 13:23):
#paper doi:10.1007/978-1-4939-1221-6_1. Evolutionary Conservation and Expression of Human RNA-Binding Proteins and Their Role in Human Genetic Disease. Adv Exp Med Biol.2014. RNA结合蛋白(RBP)是转录后基因调控(PTGR)的效应子和调节因子。RBP调节所有RNA的稳定性、成熟度和周转,通常在许多位点结合数千个靶标。RBP的重要性通过其失调或突变导致各种发育和神经系统疾病而得到强调。
此研究明确了RBP相关基因的列表,选择参与Pfam定义的RNA相关过程的RBD,并在人类基因组中搜索包含至少一个选定结构域的任何蛋白质编码基因,但总体上保持对基因及其RNA靶标的假定功能无偏倚。在获得2130个候选者的列表后,添加了来自文献检索的已知RBP,其中包含未分类的RBD,并额外筛选了通过GO和蛋白质组范围的质谱数据集基于文献的证据表明他们参与了PTGR。RBP基因列表根据以下主要标准最终确定:(1)蛋白质具有确定的RNA结合或RNA酶结构域,(2)实验证明蛋白质是RNP复合物的一部分,因此参与RNA代谢途径,或(3)它们对PTGR中涉及的同系物和副同源物具有高序列同一性。通过上述方法,最终得出了1542种蛋白质。
Advances in experimental medicine and biology,
2014.
DOI: 10.1007/978-1-4939-1221-6_1
PMID: 25201102
Abstract:
RNA-binding proteins (RBPs) are effectors and regulators of posttranscriptional gene regulation (PTGR). RBPs regulate stability, maturation, and turnover of all RNAs, often binding thousands of targets at many sites. The …
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RNA-binding proteins (RBPs) are effectors and regulators of posttranscriptional gene regulation (PTGR). RBPs regulate stability, maturation, and turnover of all RNAs, often binding thousands of targets at many sites. The importance of RBPs is underscored by their dysregulation or mutations causing a variety of developmental and neurological diseases. This chapter globally discusses human RBPs and provides a brief introduction to their identification and RNA targets. We review RBPs based on common structural RNA-binding domains, study their evolutionary conservation and expression, and summarize disease associations of different RBP classes.
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785.
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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786.
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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787.
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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788.
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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789.
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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790.
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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791.
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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792.
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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793.
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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794.
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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795.
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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796.
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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797.
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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798.
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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799.
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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800.
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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