当前共找到 1063 篇文献分享,本页显示第 121 - 140 篇。
121.
惊鸿 (2024-04-24 18:51):
#paper DNA origami mediated electrically connected metal—semiconductor junctions Pub Date : 2020-02-19 DOI : 10.1007/s12274-020-2672-5 无机纳米结构的基于DNA的纳米加工在电子,催化和等离激元学中具有潜在的应用。先前的DNA金属化已经产生了导电的DNA组装的纳米结构。然而,半导体的使用以及DNA纳米结构上良好连接的纳米级金属-半导体结的开发仍处于早期阶段。本文中,我们报告了通过金和碲纳米棒的位置特异性结合在单个DNA折纸上首次制造多个电连接的金属-半导体结。纳米棒附着到DNA折纸上的方法是通过DNA杂交获得Au,通过静电相互作用获得Te。化学镀金用于通过填充Au和Te纳米棒之间的间隙来创建纳米级金属-半导体界面。两点电特性表明,Au-Te-Au结已电连接,电流-电压特性与肖特基结一致。基于DNA的金属-半导体结的纳米加工为纳米电子学打开了潜在的机遇,证明了这种自下而上方法的强大功能。
122.
DeDe宝 (2024-04-05 01:19):
#paper, Prior probability cues bias sensory encoding with increasing task exposure, doi:https://elifesciences.org/articles/91135.先验影响被试的反应时间和反应结果,之前的计算模型通常将先验的影响归因于选择方案时的调整(即先验的影响发生在决策阶段)。然而,最近的研究表明,先验也可能直接影响感官证据(似然)。在本研究中,研究者用脑电图记录了神经活动,同时被试在多个测试过程中使用有效先验、无效先验或中性先验执行对比辨别任务。研究者通过对比依赖的稳态视觉诱发电位(SSVEP)测量了感觉证据编码,而标准调整的读数则由运动皮层上的效应器选择性 mu-β 带活动提供。研究着发现先验对运动和SSVEP 均产生了显着的调节。研究表明,除了对决策过程进行战略调整之外,先验概率信息还会引起编码的偏差。
IF:6.400Q1 eLife, 2024. DOI: 10.7554/eLife.91135.3
Abstract:
When observers have prior knowledge about the likely outcome of their perceptual decisions, they exhibit robust behavioural biases in reaction time and choice accuracy. Computational modelling typically attributes these effects … >>>
When observers have prior knowledge about the likely outcome of their perceptual decisions, they exhibit robust behavioural biases in reaction time and choice accuracy. Computational modelling typically attributes these effects to strategic adjustments in the criterion amount of evidence required to commit to a choice alternative - usually implemented by a starting point shift - but recent work suggests that expectations may also fundamentally bias the encoding of the sensory evidence itself. Here, we recorded neural activity with EEG while participants performed a contrast discrimination task with valid, invalid, or neutral probabilistic cues across multiple testing sessions. We measured sensory evidence encoding via contrast-dependent steady-state visual-evoked potentials (SSVEP), while a read-out of criterion adjustments was provided by effector-selective mu-beta band activity over motor cortex. In keeping with prior modelling and neural recording studies, cues evoked substantial biases in motor preparation consistent with criterion adjustments, but we additionally found that the cues produced a significant modulation of the SSVEP during evidence presentation. While motor preparation adjustments were observed in the earliest trials, the sensory-level effects only emerged with extended task exposure. Our results suggest that, in addition to strategic adjustments to the decision process, probabilistic information can also induce subtle biases in the encoding of the evidence itself. <<<
翻译
123.
林海onrush (2024-04-02 00:39):
#paper, Curriculum Learning and Imitation Learning for Model-free Control on Financial Time-series, doi:https://doi.org/10.48550/arXiv.2311.13326,这篇论文针对金融时间序列的无模型控制问题,提出了一种新颖的解决思路。传统的强化学习方法在这一领域面临训练数据有限且噪声大的挑战。为此,本文探索了将课程学习和模仿学习这两种在机器人领域已有成功应用的范式引入到金融问题中。通过在两个代表性的数据集上的大量实证实验,论文发现课程学习能够显著提升强化学习算法在复杂金融时间序列决策中的表现,优于所有baseline方法。课程学习通过数据增强逐步提高训练任务的难度,体现了 "由易到难" 的学习策略。实验表明,这种适度的数据平滑可以有效降低数据中的噪声,使得强化学习算法更好地捕捉到真实的市场信号。 相比之下,直接应用模仿学习的效果并不理想。进一步的分析表明,这可能是由于模仿学习在去除噪声的同时,也丢失了部分关键的市场信号。从统计学的角度看,模仿学习实现了噪声和信号的分解,但过度的去噪反而损害了策略学习的效果。 本文的理论贡献在于提出了一个信号噪声分解的统计框架,用于解释课程学习和模仿学习在金融时间序列问题上的效果差异。这一框架也为算法的改进提供了新的思路。此外,论文还讨论了一些有待未来进一步探索的方向,包括考察信号噪声分解的非平稳特性,探索其他形式的数据平滑方法,以及将课程学习拓展应用到其他类型的高噪声时间序列学习任务中。
Abstract:
Curriculum learning and imitation learning have been leveraged extensively inthe robotics domain. However, minimal research has been done on leveragingthese ideas on control tasks over highly stochastic time-series data. Here, … >>>
Curriculum learning and imitation learning have been leveraged extensively inthe robotics domain. However, minimal research has been done on leveragingthese ideas on control tasks over highly stochastic time-series data. Here, wetheoretically and empirically explore these approaches in a representativecontrol task over complex time-series data. We implement the fundamental ideasof curriculum learning via data augmentation, while imitation learning isimplemented via policy distillation from an oracle. Our findings reveal thatcurriculum learning should be considered a novel direction in improvingcontrol-task performance over complex time-series. Our ample random-seedout-sample empirics and ablation studies are highly encouraging for curriculumlearning for time-series control. These findings are especially encouraging aswe tune all overlapping hyperparameters on the baseline -- giving an advantageto the baseline. On the other hand, we find that imitation learning should beused with caution. <<<
翻译
124.
龙海晨 (2024-04-01 09:07):
#paper Yamashita S, Tanaka M, Ida C, Kouyama K, Nakae S, Matsuki T, Tsuda M, Shirai T, Kamemura K, Nishi Y, Moss J, Miwa M. Physiological levels of poly(ADP-ribose) during the cell cycle regulate HeLa cell proliferation. Exp Cell Res. 2022 Aug 1;417(1):113163. doi: 10.1016/j.yexcr.2022.113163. Epub 2022 Apr 18. PMID: 35447104; PMCID: PMC10009817. PAR: Poly(ADP-ribose) ;PARG Poly(ADP-ribose) glycohydrolase ; PARP Poly(ADP-ribose) polymerase ;该文章在在不使用PARG抑制剂的情况下量化了HeLa细胞整个细胞周期内PAR的基本水平,发现S期的PAR水平显着高于G1期,其次非应激条件下PAR的半衰期小于40秒,这与S期大量NAD +的消耗一致,这是由PARP抑制剂挽救的。第三,PARP抑制剂使细胞周期延迟至S期。第四,S期期间PAR水平的增加与PARP1、PARG、NAD +和pERK2的水平无关。第五,纯化的 PARP1 在 DNA 不存在的情况下被组蛋白 H4 激活。PARP 抑制剂延迟 S 期细胞周期并减少细胞增殖。
Abstract:
Protein targets of polyADP-ribosylation undergo covalent modification with high-molecular-weight, branched poly(ADP-ribose) (PAR) of lengths up to 200 or more ADP-ribose residues derived from NAD. PAR polymerase 1 (PARP1) is the … >>>
Protein targets of polyADP-ribosylation undergo covalent modification with high-molecular-weight, branched poly(ADP-ribose) (PAR) of lengths up to 200 or more ADP-ribose residues derived from NAD. PAR polymerase 1 (PARP1) is the most abundant and well-characterized enzyme involved in PAR biosynthesis. Extensive studies have been carried out to determine how polyADP-ribosylation (PARylation) regulates cell proliferation during cell cycle, with conflicting conclusions. Since significant activation of PARP1 occurs during cell lysis in vitro, we changed the standard method for cell lysis, and using our sensitive ELISA system, quantified without addition of a PAR glycohydrolase inhibitor and clarified that the PAR level is significantly higher in S phase than that in G1. Under normal condition in the absence of exogenous DNA-damaging agent, PAR turns over with a half-life of <40 s; consistent with significant decrease of NAD levels in S phase, which is rescued by PARP inhibitors, in line with the observed rapid turnover of PAR. PARP inhibitors delayed cell cycle in S phase and decreased cell proliferation. Our results underscore the importance of a suitable assay system to measure rapid PAR chain dynamics in living cells and aid our understanding of the function of PARylation during the cell cycle. <<<
翻译
125.
小W (2024-03-31 23:59):
#paper doi:doi.org/10.1016/j.cell.2024.01.042 Past, present, and future of CRISPR genome editing technologies 本文是对 crisper 基因编辑技术发展历程、当前应用以及未来发展方向的汇总文章。介绍了crisper 系统 对 Cas9 以外的核酸酶的探索、减少脱靶编辑的高保真 Cas9 和 递送系统 的开发,以及其在疾病建模和体内外基因治疗的展望。
IF:45.500Q1 Cell, 2024-Feb-29. DOI: 10.1016/j.cell.2024.01.042 PMID: 38428389
Abstract:
Genome editing has been a transformative force in the life sciences and human medicine, offering unprecedented opportunities to dissect complex biological processes and treat the underlying causes of many genetic … >>>
Genome editing has been a transformative force in the life sciences and human medicine, offering unprecedented opportunities to dissect complex biological processes and treat the underlying causes of many genetic diseases. CRISPR-based technologies, with their remarkable efficiency and easy programmability, stand at the forefront of this revolution. In this Review, we discuss the current state of CRISPR gene editing technologies in both research and therapy, highlighting limitations that constrain them and the technological innovations that have been developed in recent years to address them. Additionally, we examine and summarize the current landscape of gene editing applications in the context of human health and therapeutics. Finally, we outline potential future developments that could shape gene editing technologies and their applications in the coming years. <<<
翻译
126.
符毓 Yu (2024-03-31 23:50):
#paper doi.org/10.48550/arXiv.2403.16527, 2024, Hallucination Detection in Foundation Models for Decision-Making: A Flexible Definition and Review of the State of the Art. 智能控制系统能通过预训练在各场景下得到广泛应用,但在训练外场景下表现糟糕。大模型出现有希望提供现有训练方式缺乏的推理能力,但大模型会产生“幻觉”(听起来合理但很差的决策)。本文尝试定义“幻觉”,并给出检测和缓解规划中出现“幻觉”的方法分类,评估指标和数据集等
Abstract:
Autonomous systems are soon to be ubiquitous, from manufacturing autonomy toagricultural field robots, and from health care assistants to the entertainmentindustry. The majority of these systems are developed with modularsub-components … >>>
Autonomous systems are soon to be ubiquitous, from manufacturing autonomy toagricultural field robots, and from health care assistants to the entertainmentindustry. The majority of these systems are developed with modularsub-components for decision-making, planning, and control that may behand-engineered or learning-based. While these existing approaches have beenshown to perform well under the situations they were specifically designed for,they can perform especially poorly in rare, out-of-distribution scenarios thatwill undoubtedly arise at test-time. The rise of foundation models trained onmultiple tasks with impressively large datasets from a variety of fields hasled researchers to believe that these models may provide common sense reasoningthat existing planners are missing. Researchers posit that this common sensereasoning will bridge the gap between algorithm development and deployment toout-of-distribution tasks, like how humans adapt to unexpected scenarios. Largelanguage models have already penetrated the robotics and autonomous systemsdomains as researchers are scrambling to showcase their potential use cases indeployment. While this application direction is very promising empirically,foundation models are known to hallucinate and generate decisions that maysound reasonable, but are in fact poor. We argue there is a need to step backand simultaneously design systems that can quantify the certainty of a model'sdecision, and detect when it may be hallucinating. In this work, we discuss thecurrent use cases of foundation models for decision-making tasks, provide ageneral definition for hallucinations with examples, discuss existingapproaches to hallucination detection and mitigation with a focus on decisionproblems, and explore areas for further research in this exciting field. <<<
翻译
127.
muton (2024-03-31 23:40):
#paper doi: https://doi.org/10.1038/d41586-024-00930-y 非常有意思的发现👍 有点像锻炼肌肉,首先撕裂肌肉细胞,然后修复。大脑要形成强的突触联系,也需要先破坏DNA,然后修复。
IF:50.500Q1 Nature, 2024-Mar-27. DOI: 10.1038/d41586-024-00930-y PMID: 38538900
Abstract: No abstract available.
128.
小擎子 (2024-03-31 23:16):
#paper doi:10.1021/acs.estlett.4c00081 Environ. Sci. Technol. Lett., 2024, Drinking Boiled Tap Water Reduces Human Intake of Nanoplastics and Microplastics。 如果担心水里有微塑料,可以先烧开水,再过滤再喝。硬水(每升水300mg CaCO3)去除微塑料效果较好(约去除90),软水(每升水CaCO3小于60mg)效果较差(去除约25%)。作者认为粒径越小,表面能越高,越倾向于团聚或者吸附在其他物质表面,来减少自身的表面能。硬水烧开的过程中,随着水温升高,CaCO3形成了包封塑料颗粒的水垢颗粒或晶体结构。
129.
白鸟 (2024-03-31 23:05):
#paper Single-cell chromatin state analysis with Signac. Nat Methods  (2021). https://doi.org/10.1038/s41592-021-01282-5 最近分析scATAC-seq数据,用到Signac的一些函数,特别GeneActivity函数的理解。系统的学习和理解一个分析工具,还是要花大量的时间,工具包的整体分析思路,源码中如何一步步实现的,fragments到peak,peak的注释,分析延展,与同类软件的对比,需要一点点理解和消化。
IF:36.100Q1 Nature methods, 2021-11. DOI: 10.1038/s41592-021-01282-5 PMID: 34725479 PMCID:PMC9255697
Abstract:
The recent development of experimental methods for measuring chromatin state at single-cell resolution has created a need for computational tools capable of analyzing these datasets. Here we developed Signac, a … >>>
The recent development of experimental methods for measuring chromatin state at single-cell resolution has created a need for computational tools capable of analyzing these datasets. Here we developed Signac, a comprehensive toolkit for the analysis of single-cell chromatin data. Signac enables an end-to-end analysis of single-cell chromatin data, including peak calling, quantification, quality control, dimension reduction, clustering, integration with single-cell gene expression datasets, DNA motif analysis and interactive visualization. Through its seamless compatibility with the Seurat package, Signac facilitates the analysis of diverse multimodal single-cell chromatin data, including datasets that co-assay DNA accessibility with gene expression, protein abundance and mitochondrial genotype. We demonstrate scaling of the Signac framework to analyze datasets containing over 700,000 cells. <<<
翻译
130.
半面阳光 (2024-03-31 22:31):
#paper DOI: https://doi.org/10.1111/1471-0528.15006, BJOG, 2018, No-call non-invasive prenatal testing gives important information. 这篇文章是个会议论文,发表时间相对来说也比较早了,在2018年;但是这篇文章所关注的问题却很实际,即NIPT应用中无法得出结果(no-call)的样本提示了哪些信息。文章给出的信息是大约1~3%的受检者会得到一个“no-call”的结果。”no-call”的一个最常见的原因是胎儿cfDNA比例不足,即母亲的cfDNA背景高,而造成这种情况的原因又与母亲的BMI指数有关。另外,’no-call’也与母亲存在染色体非整体风险有关。这就给临床实际处理这些问题时提供了一些参考信息;对此类‘no-call’的样本,有研究建议不仅要对受检者再次进行NIPT检测,还需进行CVS检测。此外,“no-call”样本还可能与母亲的pre-eclampsia有关。而放在实际的NIPT应用中,“no-call”样本不仅可以作为一些风险信息提供辅助参考,还与NIPT检测这项技术在临床上的运行、技术评估等有关。
Abstract:
OBJECTIVE: To investigate the pregnancy outcomes in a cohort of women who failed to obtain a result in non-invasive prenatal testing (NIPT).DESIGN: Historical cohort study.SETTING: A multicentre private practice in … >>>
OBJECTIVE: To investigate the pregnancy outcomes in a cohort of women who failed to obtain a result in non-invasive prenatal testing (NIPT).DESIGN: Historical cohort study.SETTING: A multicentre private practice in Sydney, Australia.POPULATION: Women who failed to obtain a result from NIPT (n = 131).METHODS: The maternal characteristics, antenatal investigations and pregnancy outcomes for these women were compared with those who obtained a result at the same practice and to the general Australian obstetric population.MAIN OUTCOME MEASURES: Antenatal investigations: pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotrophin (β-hCG), placental growth factor (PlGF), uterine artery pulsatility index (PI), mean arterial pressure (MAP). Pregnancy outcomes: chromosomal abnormality, pre-eclampsia, gestational diabetes, small-for-gestational-age (SGA), preterm delivery.RESULTS: Only 1.1% of NIPT samples failed to return a result. This cohort was significantly older and had significantly increased weight compared with the general Australian obstetric population. Pregnancy outcomes were available for 94% of the cohort. There were significantly higher rates of chromosomal aneuploidies (6.5% versus 0.2%, P < 0.0001), pre-eclampsia (11% versus 1.5%, P < 0.0001) and gestational diabetes (23% versus 7.5%, P < 0.0001) compared with the general obstetric population. Rates of preterm delivery and SGA were elevated but did not reach significance. Antenatal investigations demonstrated decreased PAPP-A MoM (0.75 versus 1.14, P < 0.0001), decreased free β-hCG (0.71 versus 1.01, P < 0.0001) and increased uterine artery PI (1.79 versus 1.65, P = 0.02).CONCLUSION: Women who fail to obtain a result from NIPT are at increased risk of adverse pregnancy outcomes, in particular chromosomal aneuploidy, gestational diabetes and pre-eclampsia.FUNDING: None received.TWEETABLE ABSTRACT: Women who fail to obtain a result from cell-free DNA NIPT are at increased risk of adverse pregnancy outcomes. <<<
翻译
131.
朵朵 (2024-03-31 21:53):
#paper 叶昱利,李强,冯群娣.我的姐姐:男孩偏好与长姐身体健康[J].公共管理评论,2021,3(04):5-33. 我国家庭中男孩偏好现象仍相当普遍,特别是在高胎次中出生性别失衡。论文通过比较有弟弟,相对于有妹妹而言,对长姐健康的不同影响,来识别男孩偏好效应。利用头胎性别的外生性构建工具变量,运用2010—2018年中国家庭追踪调查数据中的二孩户长姐样本,论文发现,在其他情况相同的条件下,有弟弟,相较于有妹妹,显著降低了长姐的身体健康水平。异质性分析表明农村的男孩偏好效应相对较强,且男孩偏好效应随长姐年龄增加而变得更大。
132.
哪有情可长 (2024-03-31 21:28):
#paper Systemic identification of wheat spike development regulators by integrated multiomics, transcriptional network, GWAS and genetic analyses. Molecular Plant(2024). DOI:https://doi.org/10.1016/j.molp.2024.01.010对小麦穗发育的8个关键时期,利用转录组、染色质可及性和多组蛋白质修饰测序,绘制了小麦的穗发育过程中的动态转录和表观修饰图谱,构建了一个小麦穗发育过程的转录调控网络。然后在研究中发现一个跟小麦开花相关的一个调控模块,利用分子实验进行验证其模块对开花的作用,又在调控网络中鉴定发现一个新的影响穗发育的基因,最终将这些数据整合了一个小麦穗发育的网站。也为小麦研究提供了一个数据库。
IF:17.100Q1 Molecular plant, 2024-03-04. DOI: 10.1016/j.molp.2024.01.010 PMID: 38310351
Abstract:
The spike architecture of wheat plays a crucial role in determining grain number, making it a key trait for optimization in wheat breeding programs. In this study, we used a … >>>
The spike architecture of wheat plays a crucial role in determining grain number, making it a key trait for optimization in wheat breeding programs. In this study, we used a multi-omic approach to analyze the transcriptome and epigenome profiles of the young spike at eight developmental stages, revealing coordinated changes in chromatin accessibility and H3K27me3 abundance during the flowering transition. We constructed a core transcriptional regulatory network (TRN) that drives wheat spike formation and experimentally validated a multi-layer regulatory module involving TaSPL15, TaAGLG1, and TaFUL2. By integrating the TRN with genome-wide association studies, we identified 227 transcription factors, including 42 with known functions and 185 with unknown functions. Further investigation of 61 novel transcription factors using multiple homozygous mutant lines revealed 36 transcription factors that regulate spike architecture or flowering time, such as TaMYC2-A1, TaMYB30-A1, and TaWRKY37-A1. Of particular interest, TaMYB30-A1, downstream of and repressed by WFZP, was found to regulate fertile spikelet number. Notably, the excellent haplotype of TaMYB30-A1, which contains a C allele at the WFZP binding site, was enriched during wheat breeding improvement in China, leading to improved agronomic traits. Finally, we constructed a free and open access Wheat Spike Multi-Omic Database (http://39.98.48.156:8800/#/). Our study identifies novel and high-confidence regulators and offers an effective strategy for dissecting the genetic basis of wheat spike development, with practical value for wheat breeding. <<<
翻译
133.
盼盼 (2024-03-31 20:55):
https://linkinghub.elsevier.com/retrieve/pii/S0092867421005018本文应用成熟小鼠的脑组织借助merish技术对55张小鼠的冠状脑组切片测序空间转录组,同时测序对应样本的单细胞(质控后4 000 000个)。依据不同切面不同脑区的时空组表达特征的不同,每张切片都分成不同的功能分区,而大脑总的大分区11个region,时空组都可以很好地再现不同脑区的结构和空间特征。作者还应用RCTD的方法联合时空和单细胞数据,预测不同脑区的细胞类型,整个大脑组织的脑细胞分为34个亚群,其中90%的亚群种类都是神经元细胞,其中每个区的兴奋性神经元数量都是高于抑制性神经元。不同脑区神经元除了表达神经元细胞共有marker以外,还表达具有空间特异性的神经元marker,且不同脑区的神经元细胞种类差异非常大,以中脑和后脑的神经元细胞种类最为丰富。该文献展示了成年小鼠脑细胞的分子和空间特征图谱,为后来的小鼠大脑组织研究提供了数据支持。
IF:45.500Q1 Cell, 2021-06-10. DOI: 10.1016/j.cell.2021.04.021 PMID: 34004146
Abstract:
The isocortex and hippocampal formation (HPF) in the mammalian brain play critical roles in perception, cognition, emotion, and learning. We profiled ∼1.3 million cells covering the entire adult mouse isocortex … >>>
The isocortex and hippocampal formation (HPF) in the mammalian brain play critical roles in perception, cognition, emotion, and learning. We profiled ∼1.3 million cells covering the entire adult mouse isocortex and HPF and derived a transcriptomic cell-type taxonomy revealing a comprehensive repertoire of glutamatergic and GABAergic neuron types. Contrary to the traditional view of HPF as having a simpler cellular organization, we discover a complete set of glutamatergic types in HPF homologous to all major subclasses found in the six-layered isocortex, suggesting that HPF and the isocortex share a common circuit organization. We also identify large-scale continuous and graded variations of cell types along isocortical depth, across the isocortical sheet, and in multiple dimensions in hippocampus and subiculum. Overall, our study establishes a molecular architecture of the mammalian isocortex and hippocampal formation and begins to shed light on its underlying relationship with the development, evolution, connectivity, and function of these two brain structures. <<<
翻译
134.
小年 (2024-03-31 17:31):
#paper Fehlings, D.L., Zarrei, M., Engchuan, W. et al. Comprehensive whole-genome sequence analyses provide insights into the genomic architecture of cerebral palsy. Nat Genet (2024). https://doi-org-443.webvpn.las.ac.cn/10.1038/s41588-024-01686-x 本文对超过320名患有脑瘩(CP)的儿童及其生物学父母进行了全基因组测序(WGS)数据分享。研究发现,11.3%的儿童存在致病/可能致病(P/LP)变异,17.7%的儿童存在不确定意义的变异。这些变异类型包括单核苷酸变异/缺失、拷贝数变异以及线粒体变异,其中COL4A1基因发现了最多的P/LP单核苷酸变异(SNVs)。此外,本项研究还将脑瘫患者与儿科对照组进行了比较,以确立新生突变率和遗传负荷分析的基准,发现新生有害变异与与神经系统相关的基因之间存在关联。本篇文章强调,脑瘫是最常见的儿童起始期身体残疾,经常伴随认知和行为障碍等额外发展影响。研究突显了遗传因素对脑瘫的重要影响,尤其是在没有明显产前、产时或产后病理因素、足月出生以及脑部影像学正常的情况下。研究强调了脑瘫的多因素本质,涉及遗传变异与环境因素的复杂交互作用。该研究的结果支持在脑瘫的诊断流程中引入全基因组测序,以识别包括罕见变异和线粒体变异在内的广泛遗传变异。同时表明,遗传测试有助于深入了解脑瘫的病因,改善家庭咨询,并指导针对性治疗。
IF:31.700Q1 Nature genetics, 2024-Apr. DOI: 10.1038/s41588-024-01686-x PMID: 38553553
Abstract:
We performed whole-genome sequencing (WGS) in 327 children with cerebral palsy (CP) and their biological parents. We classified 37 of 327 (11.3%) children as having pathogenic/likely pathogenic (P/LP) variants and … >>>
We performed whole-genome sequencing (WGS) in 327 children with cerebral palsy (CP) and their biological parents. We classified 37 of 327 (11.3%) children as having pathogenic/likely pathogenic (P/LP) variants and 58 of 327 (17.7%) as having variants of uncertain significance. Multiple classes of P/LP variants included single-nucleotide variants (SNVs)/indels (6.7%), copy number variations (3.4%) and mitochondrial mutations (1.5%). The COL4A1 gene had the most P/LP SNVs. We also analyzed two pediatric control cohorts (n = 203 trios and n = 89 sib-pair families) to provide a baseline for de novo mutation rates and genetic burden analyses, the latter of which demonstrated associations between de novo deleterious variants and genes related to the nervous system. An enrichment analysis revealed previously undescribed plausible candidate CP genes (SMOC1, KDM5B, BCL11A and CYP51A1). A multifactorial CP risk profile and substantial presence of P/LP variants combine to support WGS in the diagnostic work-up across all CP and related phenotypes. <<<
翻译
135.
Vincent (2024-03-31 16:59):
#paper Clarifying the biological and statistical assumptions of cross-sectional biological age predictors: an elaborate illustration using synthetic and real data. BMC Medical Research Methodology. 2024. https://doi.org/10.1186/s12874-024-02181-x. 生物年龄代表了个体真实的生理状态,其与实际年龄可能会有差异(个体可能比实际年龄更年轻/更老)。生物年龄与实际年龄之间的偏离(aging divergence)激发了广泛的研究兴趣,通常认为当生物年龄大于实际年龄时,个体会有更低的预期寿命以及更高的死亡或者疾病风险。常见的生物年龄通常由生化或者分子特征预测得知,而实际应用中这类数据往往属于横截面数据(cross-section data, 指在某一个时间点收集的数据,与时序数据相区别)。 这篇文章指出,当使用的是横截面数据时候,研究 aging divergence是否与某一些性状相关往往有一个隐含假设(identical-association-assumption),即与年龄最有关的形状也必然与aging divergence最有联系。该假设是否成立直接影响分析结果是否有生物学意义。可惜的是从横截面数据中我们无法测试这种假设是否成立或者不成立(untestable)。这篇文章的主要贡献是通过模拟和真实数据显示地揭示了这个经常被忽视的隐含假设,对衰老的研究和衰老机理的解释有一些警醒作用。
Abstract:
BACKGROUND: There is divergence in the rate at which people age. The concept of biological age is postulated to capture this variability, and hence to better represent an individual's true … >>>
BACKGROUND: There is divergence in the rate at which people age. The concept of biological age is postulated to capture this variability, and hence to better represent an individual's true global physiological state than chronological age. Biological age predictors are often generated based on cross-sectional data, using biochemical or molecular markers as predictor variables. It is assumed that the difference between chronological and predicted biological age is informative of one's chronological age-independent aging divergence ∆.METHODS: We investigated the statistical assumptions underlying the most popular cross-sectional biological age predictors, based on multiple linear regression, the Klemera-Doubal method or principal component analysis. We used synthetic and real data to illustrate the consequences if this assumption does not hold.RESULTS: The most popular cross-sectional biological age predictors all use the same strong underlying assumption, namely that a candidate marker of aging's association with chronological age is directly informative of its association with the aging rate ∆. We called this the identical-association assumption and proved that it is untestable in a cross-sectional setting. If this assumption does not hold, weights assigned to candidate markers of aging are uninformative, and no more signal may be captured than if markers would have been assigned weights at random.CONCLUSIONS: Cross-sectional methods for predicting biological age commonly use the untestable identical-association assumption, which previous literature in the field had never explicitly acknowledged. These methods have inherent limitations and may provide uninformative results, highlighting the importance of researchers exercising caution in the development and interpretation of cross-sectional biological age predictors. <<<
翻译
136.
徐炳祥 (2024-03-31 16:26):
#paper doi: 10.1016/j.celrep.2020.108206 Cell Reports, 2020, tagHi-C Reveals 3D Chromatin Architecture Dynamics during Mouse Hematopoiesis。高通量染色质构象捕获技术(Hi-C)一直受限于对样品量的高要求而在一些只有有限样品的场景中应用受限。本文作者介绍了一种借助tagmentation原理的改进版tagHi-C,借助Tn5的低样品损失可以将Hi-C对样品的需求降低到百细胞量级。基于此,作者解析了小鼠造血系统发育过程中的染色质构象改变。发现染色质区室结构随造血系统的发育是高度动态的,终端分化细胞染色质呈现凝聚状态,高表达基因可自身形成结构域且结构域强度与表达水平正相关等结论。本文是in situ Hi-C以来对该技术的一项重大改进。提供了一套完整的Hi-C测试数据。
IF:7.500Q1 Cell reports, 2020-09-29. DOI: 10.1016/j.celrep.2020.108206 PMID: 32997998
Abstract:
Spatiotemporal chromatin reorganization during hematopoietic differentiation has not been comprehensively characterized, mainly because of the large numbers of starting cells required for current chromatin conformation capture approaches. Here, we introduce … >>>
Spatiotemporal chromatin reorganization during hematopoietic differentiation has not been comprehensively characterized, mainly because of the large numbers of starting cells required for current chromatin conformation capture approaches. Here, we introduce a low-input tagmentation-based Hi-C (tagHi-C) method to capture the chromatin structures of hundreds of cells. Using tagHi-C, we are able to map the spatiotemporal dynamics of chromatin structure in ten primary hematopoietic stem, progenitor, and differentiated cell populations from mouse bone marrow. Our results reveal that changes in compartment dynamics and the Rabl configuration occur during hematopoietic cell differentiation. We identify gene-body-associating domains (GADs) as general structures for highly expressed genes. Moreover, we extend the body of knowledge regarding genes influenced by genome-wide association study (GWAS) loci through spatial chromatin looping. Our study provides the tagHi-C method for studying the three-dimensional (3D) genome of a small number of cells and maps the comprehensive 3D chromatin landscape of bone marrow hematopoietic cells. <<<
翻译
137.
庞庞 (2024-03-31 16:23):
#paper doi:10.1109/msp.2022.3155951 Interpreting Brain Biomarkers: Challenges and solutions in interpreting machine learning-based predictive neuroimaging 一直比较迷惑在探索脑-行为关系时,如何解释特征权重、进一步寻找影像学生物标志物的含义。本文对大部分的使用脑指标预测行为分数的机器学习研究进行了综述,告诉我们处理特征权重的几种基本形式:1.根据权重大小解释特征重要程度2.根据权重的稳定性确定重要程度3.根据逐步去除特征,通过判断特征在模型中的贡献确定。这篇研究给了我比较系统的处理此类问题的方法,很有参考价值。
138.
前进 (2024-03-31 12:44):
#paper [1] Hu X , Kang M , Huang W ,et al.Dual-Stream Pyramid Registration Network[J].Springer, Cham, 2019.DOI:10.1007/978-3-030-32245-8_43. 这篇论文主要用于无监督的3D大脑医学图像配准。与以往的基于卷积神经网络(CNN)的配准方法不同,例如VoxelMorph,Dual-PRNet设计了一个双流架构,能够从一对3D体积图像中顺序估计多级配准场。 主要贡献包括: 设计了一个双流3D编码器-解码器网络,分别从两个输入体积计算两个卷积特征金字塔。 提出了一种顺序金字塔配准方法,设计了一系列金字塔配准(PR)模块,直接从解码特征金字塔预测多级配准场。通过顺序变形,逐渐以粗到细的方式细化配准场,使模型具有处理大变形的强大能力。 通过计算特征金字塔之间的局部3D相关性,可以进一步增强PR模块,从而得到改进的Dual-PRNet++,能够聚合丰富的详细解剖结构。 将Dual-PRNet++集成到3D分割框架中,通过精确变形体素级注释,实现联合配准和分割。 论文还介绍了相关工作,包括基于深度学习的医学图像配准方法,并对提出的方法进行了评估。在Mindboggle101数据集上,Dual-PRNet++在Dice得分上从0.511提高到0.748,大幅度超过了现有的最先进方法。此外,论文还展示了该方法在有限注释的联合学习框架中,如何通过利用有限的注释极大地促进分割任务的完成。
139.
尹志 (2024-03-31 10:33):
#paper A roadmap for the computation of persistent homology. doi: 10.1140/epjds/s13688-017-0109-5 本文是持续同调计算的经典介绍,tutorial性质。持续同调作为拓扑数据分析或者拓扑深度学习的基本概念,其基于的数据表征、计算方法、计算工具多种多样。本文综述介绍了这些内容,虽然使用的是数学语言,但不晦涩,容易理解,方便非拓扑背景的研究者与学习者对持续同调的学习和使用。
140.
李翛然 (2024-03-31 01:07):
#paper doi:doi.org/10.1021/acs.analchem.2c05065 RETURN TO ISSUEPREVARTICLENEXT Simultaneous Dual-Wavelength Source Raman Spectroscopy with a Handheld Confocal Probe for Analysis of the Chemical Composition of In Vivo Human Skin 介绍了一种便携式共焦拉曼光谱系统,具有同时双波长光源和迷你手持探头,用于分析体内人体皮肤的化学成分。该系统能够同时获取指纹区(450−1750 cm−1)和高波数区(2800−3800 cm−1)的光谱,解决了当前商用CRS系统的局限性。关键点包括创新设计结合671和785 nm激光、精确的拉曼光谱分离算法(PRSSA)用于解耦FP和HW光谱,以及数据采集时间减少超过50%。该系统在快速和超宽带光谱采集方面表现出色,显示了在临床工作流程中整合CRS的潜力。 最近可能搞个拉曼光谱仪做美容
IF:6.700Q1 Analytical chemistry, 2023-03-28. DOI: 10.1021/acs.analchem.2c05065 PMID: 36930570
Abstract:
Confocal Raman spectroscopy (CRS) is a powerful tool that has been widely used for biological tissue analysis because of its noninvasive nature, high specificity, and rich biochemical information. However, current … >>>
Confocal Raman spectroscopy (CRS) is a powerful tool that has been widely used for biological tissue analysis because of its noninvasive nature, high specificity, and rich biochemical information. However, current commercial CRS systems suffer from limited detection regions (450-1750 cm), bulky sizes, nonflexibilities, slow acquisitions by consecutive excitations, and high costs if using a Fourier transform (FT) Raman spectroscopy with an InGaAs detector, which impede their adoption in clinics. In this study, we developed a portable CRS system with a simultaneous dual-wavelength source and a miniaturized handheld probe (120 mm × 60 mm × 50 mm) that can acquire spectra in both fingerprint (FP, 450-1750 cm) and high wavenumber (HW, 2800-3800 cm) regions simultaneously. An innovative design combining 671 and 785 nm lasers for simultaneous excitation through a compact and high-efficiency (>90%) wavelength combiner was implemented. Moreover, to decouple the fused FP and HW spectra, a first-of-its-kind precise Raman spectra separation algorithm (PRSSA) was developed based on the maximum probability (MAP) estimate. The accuracy of spectra separation was greater than 99%, demonstrated in both phantom experiments and human skin measurements. The total data acquisition time was reduced by greater than 50% compared to other CRS systems. The results proved our proposed CRS system and PRSSA's superior capability in fast and ultrawideband spectra acquisition will significantly improve the integration of CRS in the clinical workflow. <<<
翻译
回到顶部