当前共找到 1086 篇文献分享,本页显示第 1041 - 1060 篇。
1041.
吴增丁
(2022-03-07 16:08):
#paper doi: 10.1016/j.ccell.2022.01.007 这篇张力和沈琳于2022年1月份发表在Cancer Cell上的一篇letter,题目是《Time to raise the bar: Transition rate of phase 1 programs on anticancer drugs》。
这篇文章的核心主题正如文章标题:一期临床的研发药物太多了,需要提高进入一期临床的门槛。
1.文章通过分析在中国的于2012-2020年期间进入一期临床的413个抗肿瘤药物(剔除了生物仿制药和非专利药)各期临床的成功率、通过率、叫停率,发现最终NMPA通过批准比例是5.8%,相比FDA通过率5.3%差异不大。但是和上一个十年(13.2%)比降低了很多;
2.分析其中的原因:a. 近十年的肿瘤药物更多是分析靶向药(MTA)和免疫抑制剂药(IO),这些药物相比之前的化疗药物,其药效和安全性上面没有更多直接的关系,药效也更加复杂,增加了不少不可控因素;b. 另外在中国有很多ME-Too药物,这些药物最终不能很好证明优于其它药物导致不能获批;
3.对比分析ME-Too 和First-in-Class药物,first-in-class药物具有更高的通过率。而且First-in-class药物一遍具有更深的pre-clinical和研究,而且在first-in-human的临床研究中更多会采用全球多中心、大cohort、biomarker-enriched的patient筛选的方法,这些方法也更有利于药物最终获批。
所以文章最终观点是:呼吁加深pre-clinical的深入研究,同时在法规上提高进入临床实验的门槛。
Abstract:
No abstract available.
1042.
颜林林
(2022-03-06 20:48):
#paper doi:10.1101/2021.07.19.452956, bioRxiv, 2022, The Tabula Sapiens: a multiple organ single cell transcriptomic atlas of humans. 这是一篇preprint,介绍了对于单细胞转录组测序而言非常重磅的一项资源。它纳入了15位捐赠者(一般由于中风、外伤或缺氧等导致死亡,参见:https://tabula-sapiens-portal.ds.czbiohub.org/whereisthedata)所提供的24个不同组织器官,分离得到将近50万个单细胞,分别进行了10x和/或SmartSeq2的单细胞转录组测序技术,分析得到400多种细胞类型的组织特异性表达数据,提供了组织间T细胞克隆分布、B细胞组织特异性突变率、细胞周期状态及不同细胞在组织器官之间的分布、个体不同组织间细胞类型特异性RNA剪接形式等重要参考基准图谱信息。同时,通过对样本进行病理切片和H&E染色等分析,也将转录组数据与宏观临床相关信息,如不同组织类型的空间异质性、细胞相对丰度估计等都做了关联和讨论。这个项目由 Tabula Sapiens Consortium 执行,其数据(包括原始测序数据和分析结果)存放在AWS、FigShare、CellXGene等平台,供全世界开放使用(但不允许在未征得该委员会及合作方同意前发表图谱或组织规模的数据分析文章),相关信息可在项目网站(https://tabula-sapiens-portal.ds.czbiohub.org/)上找到,该网站还提供了一套流程,帮助用户使用其结果来注释和解读自己的数据。有两点很值得一提:一、该委员会及项目主要由 Chan Zuckerberg Initiative 基金会支持,该基金会由 Facebook创始人马克·扎克伯格及其妻子普莉希拉·陈(生物学专业)共同创办,bioRxiv和medRxiv也是由该基金会支持建立和维持运营;二、这篇文章的通讯作者Stephen R Quake,是生物技术领域的超级大牛,他也应该是在很早期将自己基因组贡献出来验证相关高通量测序技术的名人之一,可参见2009年NBT文章(doi:10.1038/nbt.1561),该文章的受试者P0(猜测很可能就是Quake本人),基于已成为历史的Helicos Biosciences公司的单分子高通量测序技术(应该属于三代测序体系;要知道,二代测序的兴起,也仅仅开始于2008年左右),测定了该技术的最早人全基因组数据。Quake的贡献及事迹这里不做展开,有兴趣者可自行搜索。
bioRxiv,
2022.
DOI: 10.1101/2021.07.19.452956
Abstract:
No abstract available.
1043.
旺旺小小酥
(2022-02-28 23:58):
#paper 碳中和背景下的森林碳汇及其空间溢出效应[J].经济研究,2021,56(12):187-202. 通过搜集整理到的139个国家的面板数据进行关于碳汇的空间效应模型,模型是由基本的森林碳汇核算公式推导而来的。比较有意思的结论是:非政府组织活跃度能够促进本国森林碳汇的发展,但具有负向的外溢效应。这里所谓的负向外溢效应是指,当发展中国家经济处于较低水平时,非政府组织会进行森林资源的过度开采。本文还支持一个观点:城镇化人口占比对本国森林碳储量密度有显著的正向作用,理由是城镇化人口的增加会减少对森林的砍伐从而使得碳储量密度上升。
经济研究,
2021.
Abstract:
实现碳中和目标应当从"碳源"和"碳汇"两方面着手。森林具有的生态净化能力使其能够有效吸收空气中的二氧化碳,故森林碳汇将在中国实现碳中和进程中发挥重要的作用。由于森林碳汇可能存在一定的空间相关性,森林资源的自然属性决定了碳汇发展很难实现区域上的完全分割,基于全球视角的分析便成为探讨中国碳汇发展的必然前提。本文基于森林碳汇核算公式推导出碳汇空间效应模型,根据1990—2015年全球139个国家的面板数据,在分析森林碳汇影响因素的基础上,讨论了跨国间的森林碳汇溢出效应。结果表明:各国森林碳汇的发展往往无法独善其身。非政府组织活跃度能够促进本国森林碳汇的发展,但具有负向的外溢效应;森林面积的增长虽然对本国碳储量密度没有明显的正向影响,但其有利于环境的改善,对邻国具有较大的正向溢出效应;薪柴的使用会对环境有正向反馈作用,并对其他国家也能带来正向影响,表明森林可进行适量但不过度的砍伐。鉴于其他国家对中国的森林碳汇发展造成了间接的负面影响,中国在制定具体的碳汇发展政策时,需要综合考虑各个影响因素的直接效应和其他国家带来的间接影响,立足于人类命运共同体理念,与其他国家制定共同应对策略,协调促进森林碳汇的发展。
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实现碳中和目标应当从"碳源"和"碳汇"两方面着手。森林具有的生态净化能力使其能够有效吸收空气中的二氧化碳,故森林碳汇将在中国实现碳中和进程中发挥重要的作用。由于森林碳汇可能存在一定的空间相关性,森林资源的自然属性决定了碳汇发展很难实现区域上的完全分割,基于全球视角的分析便成为探讨中国碳汇发展的必然前提。本文基于森林碳汇核算公式推导出碳汇空间效应模型,根据1990—2015年全球139个国家的面板数据,在分析森林碳汇影响因素的基础上,讨论了跨国间的森林碳汇溢出效应。结果表明:各国森林碳汇的发展往往无法独善其身。非政府组织活跃度能够促进本国森林碳汇的发展,但具有负向的外溢效应;森林面积的增长虽然对本国碳储量密度没有明显的正向影响,但其有利于环境的改善,对邻国具有较大的正向溢出效应;薪柴的使用会对环境有正向反馈作用,并对其他国家也能带来正向影响,表明森林可进行适量但不过度的砍伐。鉴于其他国家对中国的森林碳汇发展造成了间接的负面影响,中国在制定具体的碳汇发展政策时,需要综合考虑各个影响因素的直接效应和其他国家带来的间接影响,立足于人类命运共同体理念,与其他国家制定共同应对策略,协调促进森林碳汇的发展。
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1044.
masion
(2022-02-28 22:39):
#paper doi.org/10.1038/nature11681 Nature volume 492, pages59–65 (2012),Algal genomes reveal evolutionary mosaicism and the fate of nucleomorphs
通过对以吞没某些真核藻类而获得光合作用的内共生体中的过渡形式吉氏藻Guillardia theta和纳氏毕氏藻Bigelowiella natans的核基因组进行测序,揭示了单细胞生物体(纳氏毕氏藻)前所未有的选择性剪接以及广泛的遗传和生化镶嵌现象,揭示了为什么会在这些物种中存在,而不存在于其他藻类中。
Abstract:
Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont …
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Cryptophyte and chlorarachniophyte algae are transitional forms in the widespread secondary endosymbiotic acquisition of photosynthesis by engulfment of eukaryotic algae. Unlike most secondary plastid-bearing algae, miniaturized versions of the endosymbiont nuclei (nucleomorphs) persist in cryptophytes and chlorarachniophytes. To determine why, and to address other fundamental questions about eukaryote-eukaryote endosymbiosis, we sequenced the nuclear genomes of the cryptophyte Guillardia theta and the chlorarachniophyte Bigelowiella natans. Both genomes have >21,000 protein genes and are intron rich, and B. natans exhibits unprecedented alternative splicing for a single-celled organism. Phylogenomic analyses and subcellular targeting predictions reveal extensive genetic and biochemical mosaicism, with both host- and endosymbiont-derived genes servicing the mitochondrion, the host cell cytosol, the plastid and the remnant endosymbiont cytosol of both algae. Mitochondrion-to-nucleus gene transfer still occurs in both organisms but plastid-to-nucleus and nucleomorph-to-nucleus transfers do not, which explains why a small residue of essential genes remains locked in each nucleomorph.
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1045.
白云飞
(2022-02-28 21:31):
#paper DOI: 10.1145/2939672.2939785,XGBoost: A Scalable Tree Boosting System
陈天奇这篇论文是16年在KDD上提出的,目前在树模型有更快更强的LightGBM,也有魔改catboost。大忙但是我们想要找到从GBDT到更快更强的树模型,还是要从这篇XGBoost开始。
XGBoost算法的在性能,速度方面都超越了其他算法。之所以这么好,主要得益于以下几个方面:
是一个基于多个弱分类器组成的模型,可以有降低防过拟合的风险。
提出了一种加权分桶,减少计算量。
对稀疏数据进行默认划分,减少计算量。
对内存的优化和做了并行化处理、
对CPU缓存的优化
对存储的优化
1. 正则化的目标函数来看,XGBoost 是一种加法模型,它包含多个个基学习器,每个基学习器可以选择 CART 或者线性函数,损失函数包含损失函数和正则项,防止过拟合。
2. 二阶泰勒展开求解来看,在求得使得目标函数最小化时,可以像 GBDT 一样计算目标函数梯度,然后让新的 CART 去拟合负梯度。不过 XGBoost 用了更优的方法,有点类似牛顿法,但又不完全一样。牛顿法是把目标函数在当前点做二阶泰勒展开,然后求解二次方程最优点。而 XGBoost 是在上一步处只对损失函数这项做了二阶泰勒展开,之后再求解最优点。
3. 缩减(shrinkage)和列抽样:这里的缩减和 GBDT 里的缩减一样,都是为了降低单棵树的影响,给后面的树留有空间。因此引入一个学习率,用它去乘每步生成的目标函数。列抽样在 GBDT 和随机森林里都有用到,它可以牺牲偏差来降低方差。实现方法就是在分裂节点的时候只用一部分特征。
4.树节点分裂:节点分裂的目标是找出一个特征,按照这个特征的某个节点分裂后,能够使目标函数降低最多。所以这里面有两层循环,外层是特征遍历,内层是特征值遍历。特征遍历没得说了,只能一个一个找,但是特征值遍历可以优化一些,缩短寻找最优分裂节点的耗时。
5. 稀疏感知:机器学习经常会碰到数据稀疏的问题,有三种情况会导致数据稀疏:1.数据存在大量缺失值2.数据中存在大量的 0 元素3.特征工程中使用了 one-hot 编码,产生了大量的 0;所以让算法能够感知数据的稀疏模式是非常重要的。XGBoost 的解决方法是在每个节点中设置一个默认方向,缺失值或者 0 元素直接走默认方向,不参与树模型的学习。
6.效率优化之分块并行:决策树学习过程中,最耗时的部分是分裂时对数据的反复排序。为了提高速度,XGBoost 用了空间换时间的方法。对于一列特征,它创建了等量的指针,每个指针都跟一个特征值绑定,采并指向对应样本,按照特征大小排序,把每一个特征的排好序的指针保存在块结构中,就实现了训练前对特征排序的目标,这样速度提升了,但是也因此需要额外空间存储指针。分条来说,块结构的设计有以下特点:1.采用 CSC(Compressed Sparse Column Format)这种稀疏格式存储数据 2.存储的特征已排好序。3.存储了指向样本的指针,因为要存取一阶导和二阶导等信息。4.由于 CSC 是按列存储的,所以可以在每次分裂时对特征使用多线程并行计算
7.缓存感知(Cache-aware)访问:提出的块结构能够优化节点分裂的时间复杂度,但是在索引样本时,存在对内存的非连续访问问题。这是因为我们是按特征大小顺序对样本进行访问,但样本不按这个顺序。对内存的非连续访问将降低 CPU 的缓存命中率。XGBoost 针对精准贪心算法和近似算法设计了两种不同的优化策略。
8.块的核外(Out-of-core)计算:当数据没办法被一次全部读入内存时,就需要用到核外计算方法,单开一个线程从硬盘上读取需要用到的数据,解决内存不够地问题。但是从硬盘读取数据相对于处理器来说是很慢的,所以 XGBoost 采用了两种方法平衡两者速度:块压缩。对于行索引,用当前索引减去开始的块索引,前面提到块大小为所以用 16 位的整数存储这个算出来的偏移,用这个偏移替代原先更占空间的索引。块分片。把数据分开存储到不同的硬盘上,等用的时候多个硬盘一起开工,提高读取速度。
Abstract:
No abstract available.
1046.
颜林林
(2022-02-28 21:05):
#paper doi:10.1101/mcs.a006198 Cold Spring Harbor Molecular Case Studies, 2022, Towards transcriptomics as a primary tool for rare disease investigation. 来自斯坦福的一篇小综述,介绍转录组测序(RNA-seq)近年在罕见病研究中的应用及进展。选择并推荐这篇paper,是因为一年多以前,有一次我跟一位医生沟通课题思路时,曾经探讨过这种可能性,由于RNA相比DNA更接近于(生物分子行使)功能,所以优先选择RNA-seq,比DNA-seq可能更具探索价值。通常,疾病的遗传学研究和分子诊断,都会在基因组(DNA)层面进行。然而在罕见病中,通过基因组测序得到的诊断率并不高,且很多基因组突变也面临注释解读的困难,因而近年开始尝试辅以RNA-seq。RNA-seq虽然不能准确代表遗传背景,但它在基因表达量变化、可变剪接、外显子跳跃,内含子保留等诸多方面,却能提供更多与疾病或表型相关的信息。在最新的大型罕见病队列中,RNA-seq也的确提升了诊断率。随着相关研究的开展,与罕见病RNA-seq相关的计算方法也有所改进,比如针对罕见病患者与对照人群比例不平衡的统计模型,再比如整合DNA与RNA测序数据的等位基因间差异表达。虽然转录组的确会受限于样本类型和采样时间,很容易从一开始就遗漏特定组学变异事件,但最新的一些研究,通过将样本细胞转分化为其他特定细胞,从而发现与疾病相关的表达基因及其突变事件,也为RNA-seq在疾病研究中的应用提供了拓展思路。目前还没有关于RNA-seq诊断率的随机临床试验,因此这些研究都还只是探索性或回顾性的,不过从所取得的进展看,RNA-seq这项经典技术的更大价值发挥,未来还是很值得期待的。
IF:1.800Q3
Cold Spring Harbor molecular case studies,
2022-02.
DOI: 10.1101/mcs.a006198
PMID: 35217565
Abstract:
In the past 5 years transcriptome or RNA-sequencing (RNA-seq) has steadily emerged as a complementary assay for rare disease diagnosis and discovery. In this perspective, we summarize several recent developments …
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In the past 5 years transcriptome or RNA-sequencing (RNA-seq) has steadily emerged as a complementary assay for rare disease diagnosis and discovery. In this perspective, we summarize several recent developments and challenges in the use of RNA-seq for rare disease investigation. Using an accessible patient sample, such as blood, skin, or muscle, RNA-seq enables the assay of expressed RNA transcripts. Analysis of RNA-seq allows the identification of aberrant or outlier gene expression and alternative splicing as functional evidence to support rare disease study and diagnosis. Further, many types of variant effects can be profiled beyond coding variants, as the consequences of noncoding variants that impact gene expression and splicing can be directly observed. This is particularly apparent for structural variants that disproportionately underlie outlier gene expression and for splicing variants in which RNA-seq can both measure aberrant canonical splicing and detect deep intronic effects. However, a major potential limitation of RNA-seq in rare disease investigation is the developmental and cell type specificity of gene expression as a pathogenic variant's effect may be limited to a specific spatiotemporal context and access to a patient's tissue sample from the relevant tissue and timing of disease expression may not be possible. We speculate that as advances in computational methods and emerging experimental techniques overcome both developmental and cell type specificity, there will be broadening use of RNA sequencing and multiomics in rare disease diagnosis and delivery of precision health.
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1047.
洪媛媛
(2022-02-28 20:12):
Methylation plotter: a web tool for dynamic visualization of DNA methylation data
Doi:https://doi.org/10.1186/1751-0473-9-11
基于R语言开发出甲基化结果可视化的网页版工具methylation plotter,最大通量能分析100个样本的100个CpG位点结果,用户需要提供每个位点的甲基化值,软件可以输出达到出版水平的图形并能进行初步的统计分析。
Abstract:
Methylation plotter is a Web tool that allows the visualization of methylation data in a user-friendly manner and with publication-ready quality. The user is asked to introduce a file containing …
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Methylation plotter is a Web tool that allows the visualization of methylation data in a user-friendly manner and with publication-ready quality. The user is asked to introduce a file containing the methylation status of a genomic region. This file can contain up to 100 samples and 100 CpGs. Optionally, the user can assign a group for each sample (i.e. whether a sample is a tumoral or normal tissue). After the data upload, the tool produces different graphical representations of the results following the most commonly used styles to display this type of data. They include an interactive plot that summarizes the status of every CpG site and for every sample in lollipop or grid styles. Methylation values ranging from 0 (unmethylated) to 1 (fully methylated) are represented using a gray color gradient. A practical feature of the tool allows the user to choose from different types of arrangement of the samples in the display: for instance, sorting by overall methylation level, by group, by unsupervised clustering or just following the order in which data were entered. In addition to the detailed plot, Methylation plotter produces a methylation profile plot that summarizes the status of the scrutinized region, a boxplot that sums up the differences between groups (if any) and a dendrogram that classifies the data by unsupervised clustering. Coupled with this analysis, descriptive statistics and testing for differences at both CpG and group levels are provided. The implementation is based in R/shiny, providing a highly dynamic user interface that generates quality graphics without the need of writing R code. Methylation plotter is freely available at http://gattaca.imppc.org:3838/methylation_plotter/.
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1048.
笑对人生
(2022-02-28 19:28):
#paper Cell types of origin of the cell-free transcriptome. Nat Biotechnol. 2022 Feb 7. doi: 10.1038/s41587-021-01188-9
2017年卢煜明教授曾联合单细胞转录组测序技术和血浆cfRNA测序全面解析了人类胚胎细胞的异质性,同时也首次发现基于cfRNA可以发现先兆子痫胎盘中绒毛滋养层细胞的功能异常。基于cfRNA的液体活检技术目前已证实能用于追溯不同的器官来源,然而,血浆cfRNA是否可以推断不同组织来源的细胞类型及其病理状态呢?该研究利用2021年公布的人类泛组织单细胞转录组图谱数据Tabula Sapiens、HPA转录组数据、GTEx、以及4个cfRNA测序数据集,证实了血浆cfRNA可用于检测多种疾病的健康人和病人之间细胞类型特异的病理差异,其中最易于预测的是来源于脑、肺、肠、肝以及肾的细胞。同时,也发现cfRNA主要的贡献细胞是免疫细胞和造血细胞。有趣的是,在该文章中用到一个经济学指标-基尼系数来衡量一个基因是否是细胞类型特异的。总的来说,这是单细胞转录组测序在临床应用中的一个很好实践。
IF:33.100Q1
Nature biotechnology,
2022-06.
DOI: 10.1038/s41587-021-01188-9
PMID: 35132263
PMCID:PMC9200634
Abstract:
Cell-free RNA from liquid biopsies can be analyzed to determine disease tissue of origin. We extend this concept to identify cell types of origin using the Tabula Sapiens transcriptomic cell …
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Cell-free RNA from liquid biopsies can be analyzed to determine disease tissue of origin. We extend this concept to identify cell types of origin using the Tabula Sapiens transcriptomic cell atlas as well as individual tissue transcriptomic cell atlases in combination with the Human Protein Atlas RNA consensus dataset. We define cell type signature scores, which allow the inference of cell types that contribute to cell-free RNA for a variety of diseases.
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1049.
草莓味儿
(2022-02-28 19:00):
#paper Liquid Biopsy to Detect Minimal Residual Disease: Methodology and Impact
# DOI: 10.3390/cancers13215364 这是一篇综述,讨论了通过液体活检在实体肿瘤中检测MRD的不同方法,它们各自的潜力和问题,以及MRD检测对癌症患者管理的临床影响。主要关注ctDNA(循环肿瘤 DNA),这是基于肿瘤特异性基因组改变的MRD的常用检测方法,并且在日常临床实践中已通过NGS方法或PCR方法得以实施。优点:为未来研究个体肿瘤患者的辅助治疗提供依据。
Abstract:
One reason why some patients experience recurrent disease after a curative-intent treatment might be the persistence of residual tumor cells, called minimal residual disease (MRD). MRD cannot be identified by …
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One reason why some patients experience recurrent disease after a curative-intent treatment might be the persistence of residual tumor cells, called minimal residual disease (MRD). MRD cannot be identified by standard radiological exams or clinical evaluation. Tumor-specific alterations found in the blood indirectly diagnose the presence of MRD. Liquid biopsies thus have the potential to detect MRD, allowing, among other things, the detection of circulating tumor DNA (ctDNA), circulating tumor cells (CTC), or tumor-specific microRNA. Although liquid biopsy is increasingly studied, several technical issues still limit its clinical applicability: low sensitivity, poor standardization or reproducibility, and lack of randomized trials demonstrating its clinical benefit. Being able to detect MRD could give clinicians a more comprehensive view of the risk of relapse of their patients and could select patients requiring treatment escalation with the goal of improving cancer survival. In this review, we are discussing the different methodologies used and investigated to detect MRD in solid cancers, their respective potentials and issues, and the clinical impacts that MRD detection will have on the management of cancer patients.
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1050.
傅宇蕾
(2022-02-28 18:08):
#paper Dexterous magnetic manipulation of conductive non-magnetic objects. #DOI: 10.1038/s41586-021-03966-6 这是一篇通过对非磁性材料进行操控的文章,利用磁场(由永磁、电磁或超导产生)和感生的磁场(由感生或,或铁磁材料产生),相互做哟个形成的里进行操控。区别于小轩,操控用到的是三自由度的过程。优点在于针对导电材料可以实现非接触操控,缺点在于力小,速度慢,实时性差。针对空间场景来说,目前离应用较远。
Abstract:
Dexterous magnetic manipulation of ferromagnetic objects is well established, with three to six degrees of freedom possible depending on object geometry. There are objects for which non-contact dexterous manipulation is …
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Dexterous magnetic manipulation of ferromagnetic objects is well established, with three to six degrees of freedom possible depending on object geometry. There are objects for which non-contact dexterous manipulation is desirable that do not contain an appreciable amount of ferromagnetic material but do contain electrically conductive material. Time-varying magnetic fields generate eddy currents in conductive materials, with resulting forces and torques due to the interaction of the eddy currents with the magnetic field. This phenomenon has previously been used to induce drag to reduce the motion of objects as they pass through a static field, or to apply force on an object in a single direction using a dynamic field, but has not been used to perform the type of dexterous manipulation of conductive objects that has been demonstrated with ferromagnetic objects. Here we show that manipulation, with six degrees of freedom, of conductive objects is possible by using multiple rotating magnetic dipole fields. Using dimensional analysis, combined with multiphysics numerical simulations and experimental verification, we characterize the forces and torques generated on a conductive sphere in a rotating magnetic dipole field. With the resulting model, we perform dexterous manipulation in simulations and physical experiments.
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1051.
ShanShan
(2022-02-28 18:07):
#paper title: SKP1 drives the prophase I to metaphase I transition during male meiosis
#link:https://pubmed.ncbi.nlm.nih.gov/32232159/
#doi:10.1126/sciadv.aaz2129 Sci Adv, 2020;
作者:该研究由美国宾夕法尼亚大学 Jeremy Wang 教授和武汉大学 罗孟成 教授合作完成(宾夕法尼亚大学博士后关永娟为第一作者)。
导读:研究发现SKP1位于减数分裂染色体联会区域,敲除SKP1导致雌雄小鼠均不育,粗线期染色体提前解离,无法进入减数分裂中期。进一步采用冈田酸处理,粗线期染色体仍然无法进入中期,这表明SKP1是减数分裂染色体获得进入中期能力所必须的一个调控因子。
研究亮点:①利用生殖细胞特异性Ddx4 cre 将SKP1敲除时发现雄性小鼠和雌性小鼠都不育;
②SKP1敲除小鼠模型是目前唯一一个具有提前解联会表型的小鼠模型
Abstract:
The meiotic prophase I to metaphase I (PI/MI) transition requires chromosome desynapsis and metaphase competence acquisition. However, control of these major meiotic events is poorly understood. Here, we identify an …
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The meiotic prophase I to metaphase I (PI/MI) transition requires chromosome desynapsis and metaphase competence acquisition. However, control of these major meiotic events is poorly understood. Here, we identify an essential role for SKP1, a core subunit of the SKP1-Cullin-F-box (SCF) ubiquitin E3 ligase, in the PI/MI transition. SKP1 localizes to synapsed chromosome axes and evicts HORMAD proteins from these regions in meiotic spermatocytes. SKP1-deficient spermatocytes display premature desynapsis, precocious pachytene exit, loss of PLK1 and BUB1 at centromeres, but persistence of HORMAD, γH2AX, RPA2, and MLH1 in diplonema. Strikingly, SKP1-deficient spermatocytes show sharply reduced MPF activity and fail to enter MI despite treatment with okadaic acid. SKP1-deficient oocytes exhibit desynapsis, chromosome misalignment, and progressive postnatal loss. Therefore, SKP1 maintains synapsis in meiosis of both sexes. Furthermore, our results support a model where SKP1 functions as the long-sought intrinsic metaphase competence factor to orchestrate MI entry during male meiosis.
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1052.
张贝
(2022-02-28 16:37):
#paper doi: 10.1038/s41576-019-0150-2 Nat Rev Genet
. 2019. RNA sequencing: the teenage years
本文是一篇关于RNA-seq的综述。文章从RNA-seq技术的发展、RNA-seq建库方法改良、RNA-seq实验方案设计、RNA-seq数据分析、其他非bulk RNA分析、非稳态RNA分析和非基因表达分析这7个方面进行介绍。
Abstract:
Over the past decade, RNA sequencing (RNA-seq) has become an indispensable tool for transcriptome-wide analysis of differential gene expression and differential splicing of mRNAs. However, as next-generation sequencing technologies have …
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Over the past decade, RNA sequencing (RNA-seq) has become an indispensable tool for transcriptome-wide analysis of differential gene expression and differential splicing of mRNAs. However, as next-generation sequencing technologies have developed, so too has RNA-seq. Now, RNA-seq methods are available for studying many different aspects of RNA biology, including single-cell gene expression, translation (the translatome) and RNA structure (the structurome). Exciting new applications are being explored, such as spatial transcriptomics (spatialomics). Together with new long-read and direct RNA-seq technologies and better computational tools for data analysis, innovations in RNA-seq are contributing to a fuller understanding of RNA biology, from questions such as when and where transcription occurs to the folding and intermolecular interactions that govern RNA function.
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1053.
吴增丁
(2022-02-28 16:36):
#paper Towards precision medicine for AML
#link https://www.nature.com/articles/s41571-021-00509-w
这篇21年发表在nature reviews clinical oncology上的文章,综述了最新的关于AML精准治疗相关的信息。在靶向治疗、免疫治疗方面非常详细地列举了对应靶点,以及这些靶点能够用来实现靶向治疗的细胞生物学逻辑。
血液病的治疗方案不像肺癌那么丰富,本综述基本上把AML目前的治疗方案和靶点都有探讨到了,适合对AML整体概貌了解
Abstract:
With rapid advances in sequencing technologies, tremendous progress has been made in understanding the molecular pathogenesis of acute myeloid leukaemia (AML), thus revealing enormous genetic and clonal heterogeneity, and paving …
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With rapid advances in sequencing technologies, tremendous progress has been made in understanding the molecular pathogenesis of acute myeloid leukaemia (AML), thus revealing enormous genetic and clonal heterogeneity, and paving the way for precision medicine approaches. The successful development of precision medicine for patients with AML has been exemplified by the introduction of targeted FLT3, IDH1/IDH2 and BCL-2 inhibitors. When used as single agents, these inhibitors display moderate antileukaemic activity. However, augmented clinical activity has been demonstrated when they are administered in combination with drugs with broader mechanisms of action targeting epigenetic and/or other oncogenic signalling pathways or with conventional cytotoxic agents. The development of immunotherapies has been hampered by the expression of antigens that are expressed by both leukaemic and non-malignant haematopoietic progenitor cells; nonetheless, a diverse range of immunotherapies are now entering clinical development. This myriad of emerging agents also creates challenges, such as how to safely combine agents with different mechanisms of action, the need to circumvent primary and secondary resistance, and new challenges in future clinical trial design. In this Review, we discuss the current state of precision medicine for AML, including both the potential to improve patient outcomes and the related challenges.
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1054.
Vincent
(2022-02-28 15:50):
#paper What are the most important statistical ideas of the past 50 years?
#Link: https://arxiv.org/abs/2012.00174
导读:作者Andrew Gelman是哥伦比亚大学统计系的教授,也是经济学人等杂志的资深统计顾问,2020年当选美国科学院院士。2021年他在arxiv上发布了这篇备受统计学家关注的文章。文中总结了过去50年来统计学领域最为重要的八大思想(he thinks) 1. 因果推断;2. bootstrap和基于模拟的推断;3.超参数模型和正则化;4.层次结构模型;5.通用计算算法;6.自适应判定分析;7.鲁棒性推断;8.探索性数据分析。个人认为第一点和第三点尤其得当。第三点基本可以囊括很多machine leanring的算法。而第一点直接影响着人们的决策和认知,多数时候我们总把相关关系误认为因果(在社会科学领域尤甚),大家如果有幸观察到网上的各类争论,不妨从这点来审视他们在论证中有没有犯这种常识性的错误。
arXiv,
2020.
DOI: 10.48550/arXiv.2012.00174
Abstract:
No abstract available.
1055.
cellsarts
(2022-02-28 15:24):
#Paper Computational prediction of secreted proteins in gram-negative bacteria
#linkhttp://creativecommons.org/licenses/by-nc-nd/4.0/
https://doi.org/10.1016/j.csbj.2021.03.019
导读:革兰氏阴性菌控制多种蛋白质分泌系统,并分泌大量的蛋白质。蛋白质可以被输出到细胞周质空间,整合到细胞膜,运输到细胞外环境,或转运到与之相互接触细胞的细胞质中。本文根据革兰氏阴性菌分泌系总结了这些蛋白的已知特征,并对其预测算法和工具进行了综述。文章是基于大量的文章阅读,没有做其它的实验的验证。除通常的SEC途径及TAT途径,还介绍了之前不常见的几个途径。个人的意见-关于在革兰氏阴性细菌中,SEC途径及TAT途径仅用于内膜蛋白及细胞周质空间蛋白转运的结论下的太早了,更广的范围内的其它的实验数据,有可能会推翻那一个论断。
IF:4.400Q2
Computational and structural biotechnology journal,
2021.
DOI: 10.1016/j.csbj.2021.03.019
PMID: 33897982
Abstract:
Gram-negative bacteria harness multiple protein secretion systems and secrete a large proportion of the proteome. Proteins can be exported to periplasmic space, integrated into membrane, transported into extracellular milieu, or …
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Gram-negative bacteria harness multiple protein secretion systems and secrete a large proportion of the proteome. Proteins can be exported to periplasmic space, integrated into membrane, transported into extracellular milieu, or translocated into cytoplasm of contacting cells. It is important for accurate, genome-wide annotation of the secreted proteins and their secretion pathways. In this review, we systematically classified the secreted proteins according to the types of secretion systems in Gram-negative bacteria, summarized the known features of these proteins, and reviewed the algorithms and tools for their prediction.
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1056.
Marvel
(2022-02-28 14:52):
#paper title: Blockade or Deletion of IFNγ Reduces Macrophage Activation without Compromising CAR T-cell Function in Hematologic Malignancies
#link: https://pubmed.ncbi.nlm.nih.gov/35015685/
#doi: 10.1158/2643-3230.BCD-21-0181
导读:CAR-T疗法已在血液瘤患者上产出良好结果,但通常会诱发细胞介导的临床毒性,这不仅仅会损害患者身体健康,同时会加重患者经济负担,因为他们会因此而延长住院时间。目前临床上的细胞因子拮抗剂并不能完全缓解这些副反应,即使是预防性给药也不成,大概是因为这些拮抗剂仅靶向炎症的下游因素。由T细胞介导的细胞因子IFNγ作为CRS的生物标志物之一, 也是固有免疫细胞可能的激活子。基于IFNγ和CRS之间强的临床相关性,本文研究团队将IFNγ通路确定为潜在靶标。这一方法直接靶向CAR-T细胞本身,而不是下游巨噬细胞功能,有可能将临床毒性阻断在发生之前。并基于实验地提出:提出CAR-T有效性和细胞毒性并非唇齿相依,是可以分割开来的,以更好地改善临床效果。
Abstract:
Chimeric antigen receptor (CAR) T cells induce impressive responses in patients with hematologic malignancies but can also trigger cytokine release syndrome (CRS), a systemic toxicity caused by activated CAR T …
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Chimeric antigen receptor (CAR) T cells induce impressive responses in patients with hematologic malignancies but can also trigger cytokine release syndrome (CRS), a systemic toxicity caused by activated CAR T cells and innate immune cells. Although IFNγ production serves as a potency assay for CAR T cells, its biologic role in conferring responses in hematologic malignancies is not established. Here we show that pharmacologic blockade or genetic knockout of IFNγ reduced immune checkpoint protein expression with no detrimental effect on antitumor efficacy against hematologic malignancies in vitro or in vivo. Furthermore, IFNγ blockade reduced macrophage activation to a greater extent than currently used cytokine antagonists in immune cells from healthy donors and serum from patients with CAR T-cell-treated lymphoma who developed CRS. Collectively, these data show that IFNγ is not required for CAR T-cell efficacy against hematologic malignancies, and blocking IFNγ could simultaneously mitigate cytokine-related toxicities while preserving persistence and antitumor efficacy.
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1057.
吴建虎
(2022-02-28 11:32):
#paper doi:10.1016/j.cell.2019.09.019 Cell 2019 Large-Scale Whole-Genome Sequencing of Three Diverse Asian Populations in Singapore SG10K pilot study
一共4810个WGS样本:Chinese:2,780,Malay:903,Indian:1,127 ,平均深度:13.7X,从常染色体以及X染色体中一共找到89.16M的SNPs和9.11M的indels。文章将重点放在了群体结构分析上,同时对于低深度测序结果的校正上给定了一个新的思路。SG10K 数据库丰富了东亚和南亚人群的基因型,结合1KGP数据库可以很好的对Imputation结果进行校正。根据群体结构分析发现Malay人可能将是SG10K的亮点,这对于CDX人群分析提供了新的帮助。
个人感觉:文章仍有一些不足之处,比如关于假阳性的问题没有正面回答,让人对于后续的分析结果产生疑问。
Abstract:
Underrepresentation of Asian genomes has hindered population and medical genetics research on Asians, leading to population disparities in precision medicine. By whole-genome sequencing of 4,810 Singapore Chinese, Malays, and Indians, …
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Underrepresentation of Asian genomes has hindered population and medical genetics research on Asians, leading to population disparities in precision medicine. By whole-genome sequencing of 4,810 Singapore Chinese, Malays, and Indians, we found 98.3 million SNPs and small insertions or deletions, over half of which are novel. Population structure analysis demonstrated great representation of Asian genetic diversity by three ethnicities in Singapore and revealed a Malay-related novel ancestry component. Furthermore, demographic inference suggested that Malays split from Chinese ∼24,800 years ago and experienced significant admixture with East Asians ∼1,700 years ago, coinciding with the Austronesian expansion. Additionally, we identified 20 candidate loci for natural selection, 14 of which harbored robust associations with complex traits and diseases. Finally, we show that our data can substantially improve genotype imputation in diverse Asian and Oceanian populations. These results highlight the value of our data as a resource to empower human genetics discovery across broad geographic regions.
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1058.
思考问题的熊
(2022-02-27 22:55):
#paper 深夜文献安利
简要解读
https://kaopubear.top/blog/2022-02-27-do-clinical-decisions/
通过阅读这篇文献,你一方面可以了解目前的生物标志物物相关高频基因和高频突变位点(有附件可下载),另一方面可以了解临床决策的基本逻辑和重要数据库,最后还能获得一个即刻可用的在线突变注释工具MTPB
Tamborero, D., Dienstmann, R., Rachid, M.H. et al. The Molecular Tumor Board Portal supports clinical decisions and automated reporting for precision oncology. Nat Cancer 3, 251–261 (2022). https://doi.org/10.1038/s43018-022-00332-x
Abstract:
There is a growing need for systems that efficiently support the work of medical teams at the precision-oncology point of care. Here, we present the implementation of the Molecular Tumor …
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There is a growing need for systems that efficiently support the work of medical teams at the precision-oncology point of care. Here, we present the implementation of the Molecular Tumor Board Portal (MTBP), an academic clinical decision support system developed under the umbrella of Cancer Core Europe that creates a unified legal, scientific and technological platform to share and harness next-generation sequencing data. Automating the interpretation and reporting of sequencing results decrease the need for time-consuming manual procedures that are prone to errors. The adoption of an expert-agreed process to systematically link tumor molecular profiles with clinical actions promotes consistent decision-making and structured data capture across the connected centers. The use of information-rich patient reports with interactive content facilitates collaborative discussion of complex cases during virtual molecular tumor board meetings. Overall, streamlined digital systems like the MTBP are crucial to better address the challenges brought by precision oncology and accelerate the use of emerging biomarkers.
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1059.
Ricardo
(2022-02-27 22:12):
#paper doi:https://doi.org/10.1038/s41592-020-01008-z nnU-Net: a self-configuring method for deep learning-based biomedical image segmentation 介绍这一篇2020年发表在nature methods上的文章,做医学图像算法的同学估计都知道这个非常牛逼的工作,用一套自己设计的图像分割的pipeline,没有对神经网络结构做什么改进,在23个公开的医学影像数据集上大都获得了非常好的结果。细看文章和源码,可以看到作者在数据集的预处理上、超参数的选择上、模型调优和集成以及后处理等步骤上做了相当多的工作。
Abstract:
Biomedical imaging is a driver of scientific discovery and a core component of medical care and is being stimulated by the field of deep learning. While semantic segmentation algorithms enable …
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Biomedical imaging is a driver of scientific discovery and a core component of medical care and is being stimulated by the field of deep learning. While semantic segmentation algorithms enable image analysis and quantification in many applications, the design of respective specialized solutions is non-trivial and highly dependent on dataset properties and hardware conditions. We developed nnU-Net, a deep learning-based segmentation method that automatically configures itself, including preprocessing, network architecture, training and post-processing for any new task. The key design choices in this process are modeled as a set of fixed parameters, interdependent rules and empirical decisions. Without manual intervention, nnU-Net surpasses most existing approaches, including highly specialized solutions on 23 public datasets used in international biomedical segmentation competitions. We make nnU-Net publicly available as an out-of-the-box tool, rendering state-of-the-art segmentation accessible to a broad audience by requiring neither expert knowledge nor computing resources beyond standard network training.
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1060.
大象城南
(2022-02-27 21:46):
#paper doi:10.1016/j.neuroimage.2011.01.055 一种改进的对电生理数据计算信号之间相位同步方法——加权相位延迟指数,可以有效避免容积导电现象。这篇文章作者主要提出了一种更加鲁棒的功能连接度量方法。通常我们从LFP、EEG或MEG信号中测量神经元群之间的相互作用时,会采用诸如相位同步,相位相干的计算方法。然而由于空间分辨率并没有接近皮层下神经元的分布,且在头皮测量的EEG和MEG信号会经过颅骨,脑脊液衰减,这种会引起皮层下神经元群的信号在脑皮层测量的信号之间混杂着交互,从而使得度量真实的功能连接不准确。尽管之前有研究者提出虚部相干指数和相位延迟指数,但其要么无法准确度量噪声无关的信号相位的延迟或超前,要么对一些小的相位扰动不敏感,此外也会受到样本量大小产生偏差。为了解决这个问题,作者提出了加权的相位延迟指数具有无偏性,比前人提出的指标更能有效避免容积导电现象。目前该文章被引用900多次。
Abstract:
Phase-synchronization is a manifestation of interaction between neuronal groups measurable from LFP, EEG or MEG signals, however, volume conduction can cause the coherence and the phase locking value to spuriously …
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Phase-synchronization is a manifestation of interaction between neuronal groups measurable from LFP, EEG or MEG signals, however, volume conduction can cause the coherence and the phase locking value to spuriously increase. It has been shown that the imaginary component of the coherency (ImC) cannot be spuriously increased by volume-conduction of independent sources. Recently, it was proposed that the phase lag index (PLI), which estimates to what extent the phase leads and lags between signals from two sensors are nonequiprobable, improves on the ImC. Compared to ImC, PLI has the advantage of being less influenced by phase delays. However, sensitivity to volume-conduction and noise, and capacity to detect changes in phase-synchronization, is hindered by the discontinuity of the PLI, as small perturbations turn phase lags into leads and vice versa. To solve this problem, we introduce a related index, namely the weighted phase lag index (WPLI). Differently from PLI, in WPLI the contribution of the observed phase leads and lags is weighted by the magnitude of the imaginary component of the cross-spectrum. We demonstrate two advantages of the WPLI over the PLI, in terms of reduced sensitivity to additional, uncorrelated noise sources and increased statistical power to detect changes in phase-synchronization. Another factor that can affect phase-synchronization indices is sample-size bias. We show that, when directly estimated, both PLI and the magnitude of the ImC have typically positively biased estimators. To solve this problem, we develop an unbiased estimator of the squared PLI, and a debiased estimator of the squared WPLI.
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