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321.
周周复始
(2023-08-31 22:40):
#paper Mapping Human Cortical Areas In Vivo Based on Myelin Content as Revealed by T1- and T2-Weighted MRI.DOI: https://doi.org/10.1523/JNEUROSCI.2180-11.2011.这篇文章介绍了一种基于T1加权(T1w)和T2加权(T2w)MRI图像中髓鞘含量的方法来绘制人类大脑皮层区域的分布图。该方法可以在不同的3T扫描仪和脉冲序列之间通用。通过使用T1w/T2w图像强度的比率来消除与MRI相关的图像强度偏差,并提高髓鞘的对比噪声比。每个受试者的数据都被映射到皮层表面,并通过基于表面的配准在个体之间对齐。群体平均髓鞘图的空间梯度提供了一个观察者无关的方法,用于测量皮层表面上的髓鞘含量的急剧变化,即假定的皮层区域边界。研究发现,髓鞘图的梯度与已发表的基于概率的细胞构架定义的皮层区域的梯度非常吻合,这些区域已经配准到了相同的基于表面的大脑图谱。对于其他皮层区域,研究使用了已发表的解剖和功能信息,对数十个皮层区域或候选区域进行了可能的鉴定。总体上,初级和早期的单模联合皮质具有丰富的髓鞘,而更高级、多模联合的皮质具有较少的髓鞘,但文献中也有一些例外情况,这些例外情况也在研究结果中得到了证实。髓鞘图中的整体模式还与亚皮质白质髓鞘发育的起始、人类相对于猕猴的进化皮层区域扩展、人类的产后皮层扩展以及非人类灵长类动物的神经元密度分布图有重要的相关性。
Abstract:
Noninvasively mapping the layout of cortical areas in humans is a continuing challenge for neuroscience. We present a new method of mapping cortical areas based on myelin content as revealed …
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Noninvasively mapping the layout of cortical areas in humans is a continuing challenge for neuroscience. We present a new method of mapping cortical areas based on myelin content as revealed by T1-weighted (T1w) and T2-weighted (T2w) MRI. The method is generalizable across different 3T scanners and pulse sequences. We use the ratio of T1w/T2w image intensities to eliminate the MR-related image intensity bias and enhance the contrast to noise ratio for myelin. Data from each subject were mapped to the cortical surface and aligned across individuals using surface-based registration. The spatial gradient of the group average myelin map provides an observer-independent measure of sharp transitions in myelin content across the surface--i.e., putative cortical areal borders. We found excellent agreement between the gradients of the myelin maps and the gradients of published probabilistic cytoarchitectonically defined cortical areas that were registered to the same surface-based atlas. For other cortical regions, we used published anatomical and functional information to make putative identifications of dozens of cortical areas or candidate areas. In general, primary and early unimodal association cortices are heavily myelinated and higher, multimodal, association cortices are more lightly myelinated, but there are notable exceptions in the literature that are confirmed by our results. The overall pattern in the myelin maps also has important correlations with the developmental onset of subcortical white matter myelination, evolutionary cortical areal expansion in humans compared with macaques, postnatal cortical expansion in humans, and maps of neuronal density in non-human primates.
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322.
符毓 Yu
(2023-08-31 22:39):
#paper doi.org/10.48550/arXiv.2303.09165 2023, A New Benchmark: On the Utility of Synthetic Data with Blender for Bare Supervised Learning and Downstream Domain Adaptation。 为了解决机器视觉中大量人工标注的成本问题,团队尝试通过用合成数据的方式解决。基于一定规则生成合成数据后,本文展示了通过合成数据进行预训练的方式优于真实数据,同时也能优于几种数据增加后的结果的可能性。未来应用具有较大的想象力
arXiv,
2023.
DOI: 10.48550/arXiv.2303.09165
Abstract:
Deep learning in computer vision has achieved great success with the price of large-scale labeled training data. However, exhaustive data annotation is impracticable for each task of all domains of …
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Deep learning in computer vision has achieved great success with the price of large-scale labeled training data. However, exhaustive data annotation is impracticable for each task of all domains of interest, due to high labor costs and unguaranteed labeling accuracy. Besides, the uncontrollable data collection process produces non-IID training and test data, where undesired duplication may exist. All these nuisances may hinder the verification of typical theories and exposure to new findings. To circumvent them, an alternative is to generate synthetic data via 3D rendering with domain randomization. We in this work push forward along this line by doing profound and extensive research on bare supervised learning and downstream domain adaptation. Specifically, under the well-controlled, IID data setting enabled by 3D rendering, we systematically verify the typical, important learning insights, e.g., shortcut learning, and discover the new laws of various data regimes and network architectures in generalization. We further investigate the effect of image formation factors on generalization, e.g., object scale, material texture, illumination, camera viewpoint, and background in a 3D scene. Moreover, we use the simulation-to-reality adaptation as a downstream task for comparing the transferability between synthetic and real data when used for pre-training, which demonstrates that synthetic data pre-training is also promising to improve real test results. Lastly, to promote future research, we develop a new large-scale synthetic-to-real benchmark for image classification, termed S2RDA, which provides more significant challenges for transfer from simulation to reality. The code and datasets are available at this https URL.
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323.
张贝
(2023-08-31 22:32):
#paper Lung cancer scRNA-seq and lipidomics reveal aberrant lipid metabolism for early-stage diagnosis. Sci Transi Med.2022 Feb 2;14(630):eabk2756. doi: 10.1126/scitranslmed.abk2756.
本研究首先通过单细胞测序技术分析早期肺癌组织与健康肺组织之间的表达差异,发现在肺癌组织中脂代谢通路相关基因表达显著下调,提示外周血脂代谢产物可作为肺癌早筛的生物标志物。通过高分辨质谱平台分析肺癌患者和健康人外周血脂代谢产物异同,构建并优化肺癌预测模型(分别构建LCAIDv1.0和LCAIDv2.0两个版本模型),分析两个版本模型的检测性能(前者包括训练集/测试集,后者包括训练集/独立验证集/筛查队列/前瞻队列),论证了LCAID在肺癌早筛中非常可靠有效。LCAIDv2.0在1.0版本上共筛选出9个血浆脂质标志物,提示该方法具有IVD的可能性。
IF:15.800Q1
Science translational medicine,
2022-02-02.
DOI: 10.1126/scitranslmed.abk2756
PMID: 35108060
Abstract:
Lung cancer is the leading cause of cancer mortality, and early detection is key to improving survival. However, there are no reliable blood-based tests currently available for early-stage lung cancer …
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Lung cancer is the leading cause of cancer mortality, and early detection is key to improving survival. However, there are no reliable blood-based tests currently available for early-stage lung cancer diagnosis. Here, we performed single-cell RNA sequencing of different early-stage lung cancers and found that lipid metabolism was broadly dysregulated in different cell types, with glycerophospholipid metabolism as the most altered lipid metabolism-related pathway. Untargeted lipidomics was carried out in an exploratory cohort of 311 participants. Through support vector machine algorithm-based and mass spectrum-based feature selection, we identified nine lipids (lysophosphatidylcholines 16:0, 18:0, and 20:4; phosphatidylcholines 16:0-18:1, 16:0-18:2, 18:0-18:1, 18:0-18:2, and 16:0-22:6; and triglycerides 16:0-18:1-18:1) as the features most important for early-stage cancer detection. Using these nine features, we developed a liquid chromatography-mass spectrometry (MS)-based targeted assay using multiple reaction monitoring. This target assay achieved 100.00% specificity on an independent validation cohort. In a hospital-based lung cancer screening cohort of 1036 participants examined by low-dose computed tomography and a prospective clinical cohort containing 109 participants, the assay reached more than 90.00% sensitivity and 92.00% specificity. Accordingly, matrix-assisted laser desorption/ionization MS imaging confirmed that the selected lipids were differentially expressed in early-stage lung cancer tissues in situ. This method, designated as Lung Cancer Artificial Intelligence Detector, may be useful for early detection of lung cancer or large-scale screening of high-risk populations for cancer prevention.
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324.
芝麻
(2023-08-31 22:31):
#paper doi: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8809251/ Parallel analysis of transcription, integration, and sequence of single HIV-1 proviruses
作者发现在个别细胞中,HIV病毒基因表达不会因为受到药物的影响,这种特异性被发现与HIV整合在基因组的区域相关:在非基因区域整合的HIV-1原类病毒表现出显著较低的转录活性,而在染色质某些特殊功能区域附近整合时,HIV病毒的转录活性会显著增强。并且,当HIV整合位点接近激活的组蛋白修饰(H3K4me1、H3K4me3和H3K27ac)时,对于HIV基因转录活性有促进作用。
Abstract:
HIV-1-infected cells that persist despite antiretroviral therapy (ART) are frequently considered "transcriptionally silent," but active viral gene expression may occur in some cells, challenging the concept of viral latency. Applying …
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HIV-1-infected cells that persist despite antiretroviral therapy (ART) are frequently considered "transcriptionally silent," but active viral gene expression may occur in some cells, challenging the concept of viral latency. Applying an assay for profiling the transcriptional activity and the chromosomal locations of individual proviruses, we describe a global genomic and epigenetic map of transcriptionally active and silent proviral species and evaluate their longitudinal evolution in persons receiving suppressive ART. Using genome-wide epigenetic reference data, we show that proviral transcriptional activity is associated with activating epigenetic chromatin features in linear proximity of integration sites and in their inter- and intrachromosomal contact regions. Transcriptionally active proviruses were actively selected against during prolonged ART; however, this pattern was violated by large clones of virally infected cells that may outcompete negative selection forces through elevated intrinsic proliferative activity. Our results suggest that transcriptionally active proviruses are dynamically evolving under selection pressure by host factors.
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325.
小W
(2023-08-31 22:27):
#paper doi:https://doi.org/10.1038/s41586-023-06291-2 Large language models encode clinical knowledge 本文是谷歌一篇介绍医学LLM(大型语言模型)的文章。作者进行了以下工作,1. 提出了包含医学考试、研究和医患问答数据 的医学问答基准测试数据集MultiMedQA 2. 从科学基础、理解推理能力、答案准确和完整、误诊伤害等方面提出了人类对医学LMM的评估框架 3.基于Flan-PaLM模型,使用 instruction prompt tuning 迁移到新知识,生成 Med-PaLM 模型 4. 对 PaLM ,Flan-PaLM 和 Med-PaLM 模型进行评估,Med-PaLM 在其中几个指标上大大缩小了与临床医生的差距,还没找到试用。
Abstract:
Large language models (LLMs) have demonstrated impressive capabilities, but the bar for clinical applications is high. Attempts to assess the clinical knowledge of models typically rely on automated evaluations based …
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Large language models (LLMs) have demonstrated impressive capabilities, but the bar for clinical applications is high. Attempts to assess the clinical knowledge of models typically rely on automated evaluations based on limited benchmarks. Here, to address these limitations, we present MultiMedQA, a benchmark combining six existing medical question answering datasets spanning professional medicine, research and consumer queries and a new dataset of medical questions searched online, HealthSearchQA. We propose a human evaluation framework for model answers along multiple axes including factuality, comprehension, reasoning, possible harm and bias. In addition, we evaluate Pathways Language Model (PaLM, a 540-billion parameter LLM) and its instruction-tuned variant, Flan-PaLM on MultiMedQA. Using a combination of prompting strategies, Flan-PaLM achieves state-of-the-art accuracy on every MultiMedQA multiple-choice dataset (MedQA, MedMCQA, PubMedQA and Measuring Massive Multitask Language Understanding (MMLU) clinical topics), including 67.6% accuracy on MedQA (US Medical Licensing Exam-style questions), surpassing the prior state of the art by more than 17%. However, human evaluation reveals key gaps. To resolve this, we introduce instruction prompt tuning, a parameter-efficient approach for aligning LLMs to new domains using a few exemplars. The resulting model, Med-PaLM, performs encouragingly, but remains inferior to clinicians. We show that comprehension, knowledge recall and reasoning improve with model scale and instruction prompt tuning, suggesting the potential utility of LLMs in medicine. Our human evaluations reveal limitations of today's models, reinforcing the importance of both evaluation frameworks and method development in creating safe, helpful LLMs for clinical applications.
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326.
尹志
(2023-08-31 22:11):
#paper https://doi.org/10.48550/arXiv.1812.07907 PnP-AdaNet: Plug-and-Play Adversarial Domain Adaptation Network at Unpaired Cross-Modality Cardiac Segmentation。调研高效生成模型的过程中偶遇的论文,发现还是有点意思的。文章提出了一个网络结构:PnP-AdaNet,实现了无监督的不同模态间分割任务领域适应。考虑到是2018年的老文章,其替换网络结构和利用对抗学习的想法现在已经比较常见,但我认为替换网络的思想在大模型盛行的今天有着更深刻的内涵,本人手头的一个研究主题也是沿着这条线索,目前看部分实验结果还是很不错的。
arXiv,
2018.
DOI: 10.48550/arXiv.1812.07907
Abstract:
Deep convolutional networks have demonstrated the state-of-the-art performance on various medical image computing tasks. Leveraging images from different modalities for the same analysis task holds clinical benefits. However, the generalization …
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Deep convolutional networks have demonstrated the state-of-the-art performance on various medical image computing tasks. Leveraging images from different modalities for the same analysis task holds clinical benefits. However, the generalization capability of deep models on test data with different distributions remain as a major challenge. In this paper, we propose the PnPAdaNet (plug-and-play adversarial domain adaptation network) for adapting segmentation networks between different modalities of medical images, e.g., MRI and CT. We propose to tackle the significant domain shift by aligning the feature spaces of source and target domains in an unsupervised manner. Specifically, a domain adaptation module flexibly replaces the early encoder layers of the source network, and the higher layers are shared between domains. With adversarial learning, we build two discriminators whose inputs are respectively multi-level features and predicted segmentation masks. We have validated our domain adaptation method on cardiac structure segmentation in unpaired MRI and CT. The experimental results with comprehensive ablation studies demonstrate the excellent efficacy of our proposed PnP-AdaNet. Moreover, we introduce a novel benchmark on the cardiac dataset for the task of unsupervised cross-modality domain adaptation. We will make our code and database publicly available, aiming to promote future studies on this challenging yet important research topic in medical imaging.
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327.
哪有情可长
(2023-08-31 20:32):
#paper Whole-genome sequencing of diverse wheat accessions uncovers the genetic changes during modern breeding in China and the United States,The Plant Cell, 30 August 2023. https://doi.org/10.1093/plcell/koad229. 该论文对中国和美国目前的小麦育成品种以及地方品种进行表型鉴定和重测序分析,发现现代育成品种的表型和遗传多样性与地方品种相比发生了很大的变化。其中中美育种品种跟地方品种相比具有产量高,株高低,花期短等特征。在产量提高方面,中国和美国的育种偏好不同,中国育种家侧重增加籽粒大小,穗粒数和千粒重等因素来提高小麦的产量,而美国主要是依靠增加小麦的分蘖数目提高单位面积穗数,从而提高小麦的产量。这些表型数据结果表明了中美两国对小麦表型的重塑方面存在差异。依据重测序结果,对21个农艺性状进行GWAS分析,共鉴定到207个控制农艺性状的位点,并绘制了这些位点的指纹图谱。发现大部分位点的优异等位变异频率在中美品种均增加,但是增加幅度有所差异,说明这些控制性状的位点在现代育种过程中的不同地区进行了趋同选择。此外作者还进行选择信号分析,其中15%区域受到选择。比较有趣的是,中美育种家可能是通过选择同一基因,或者同一基因不同单倍型或同一基因在不同亚基因组上的同源基因来实现对同一性状的重塑。这篇文章对中国小麦育种进程分析提供了一些思路。
Abstract:
Breeding has dramatically changed the plant architecture of wheat (Triticum aestivum), resulting in the development of high-yielding varieties adapted to modern farming systems. However, how wheat breeding shaped the genomic …
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Breeding has dramatically changed the plant architecture of wheat (Triticum aestivum), resulting in the development of high-yielding varieties adapted to modern farming systems. However, how wheat breeding shaped the genomic architecture of this crop remains poorly understood. Here, we performed a comprehensive comparative analysis of a whole-genome resequencing panel of 355 common wheat accessions (representing diverse landraces and modern cultivars from China and the United States) at the phenotypic and genomic levels. The genetic diversity of modern wheat cultivars was clearly reduced compared to landraces. Consistent with these genetic changes, most phenotypes of cultivars from China and the United States were significantly altered. Of the 21 agronomic traits investigated, 8 showed convergent changes between the 2 countries. Moreover, of the 207 loci associated with these 21 traits, more than half overlapped with genomic regions that showed evidence of selection. The distribution of selected loci between the Chinese and American cultivars suggests that breeding for increased productivity in these 2 regions was accomplished by pyramiding both shared and region-specific variants. This work provides a framework to understand the genetic architecture of the adaptation of wheat to diverse agricultural production environments, as well as guidelines for optimizing breeding strategies to design better wheat varieties.
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328.
半面阳光
(2023-08-31 19:14):
#paper DOI:https://doi.org/10.1016/j.gim.2023.100879, genetics in medicine, 2023,Performance of prenatal cfDNA screening for sex chromosomes. 这篇文章主要是评估基于SNP方法的NIPT在所有受检人群(包括正常风险人群体和高风险群体)中,筛查性染色体异常(SCAs)的表现。这是一个多中心、前瞻性的研究,涵盖的性染色体异常SCAs包括单体X(MX)和性染色体三体(SCT:47,XXX;47,XXY;47,XYY)。
符合纳入标准的共有17,538例病例。对于MX、SCTs和胎儿性别,基于cfDNA的检测性能分别在17,297、10,333和14,486例妊娠中进行了确定。MX的敏感性、特异性和阳性预测值(PPV)分别为83.3%、99.9%和22.7%,而合并SCTs的敏感性、特异性和PPV分别为70.4%、99.9%和82.6%。 cfDNA对胎儿性别的预测准确性为100%。
研究结论是cfDNA在SCAs的筛查性能与其他研究中报告的相当。对于SCTs的PPV与常染色体三体相似,而MX的PPV则显著较低。这些数据将有助于解释和咨询基于cfDNA的NIPT性染色体异常的筛查结果。
IF:6.600Q1
Genetics in medicine : official journal of the American College of Medical Genetics,
2023-08.
DOI: 10.1016/j.gim.2023.100879
PMID: 37154148
Abstract:
PURPOSE: The aim of this study was to assess the performance of cell-free DNA (cfDNA) screening to detect sex chromosome aneuploidies (SCAs) in an unselected obstetrical population with genetic confirmation.METHODS: …
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PURPOSE: The aim of this study was to assess the performance of cell-free DNA (cfDNA) screening to detect sex chromosome aneuploidies (SCAs) in an unselected obstetrical population with genetic confirmation.METHODS: This was a planned secondary analysis of the multicenter, prospective SNP-based Microdeletion and Aneuploidy RegisTry (SMART) study. Patients receiving cfDNA results for autosomal aneuploidies and who had confirmatory genetic results for the relevant sex chromosomal aneuploidies were included. Screening performance for SCAs, including monosomy X (MX) and the sex chromosome trisomies (SCT: 47,XXX; 47,XXY; 47,XYY) was determined. Fetal sex concordance between cfDNA and genetic screening was also evaluated in euploid pregnancies.RESULTS: A total of 17,538 cases met inclusion criteria. Performance of cfDNA for MX, SCTs, and fetal sex was determined in 17,297, 10,333, and 14,486 pregnancies, respectively. Sensitivity, specificity, and positive predictive value (PPV) of cfDNA were 83.3%, 99.9%, and 22.7% for MX and 70.4%, 99.9%, and 82.6%, respectively, for the combined SCTs. The accuracy of fetal sex prediction by cfDNA was 100%.CONCLUSION: Screening performance of cfDNA for SCAs is comparable to that reported in other studies. The PPV for the SCTs was similar to the autosomal trisomies, whereas the PPV for MX was substantially lower. No discordance in fetal sex was observed between cfDNA and postnatal genetic screening in euploid pregnancies. These data will assist interpretation and counseling for cfDNA results for sex chromosomes.
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329.
白鸟
(2023-08-30 10:19):
#paper doi:10.1038/s41586-023-06130-4. Nature, 2023, Hallmarks of transcriptional intratumour heterogeneity across a thousand tumours. 本文利用公开数据集发表nature文章,研究肿瘤内异质性ITH,进行系统的泛癌转录特征分析。文章整合77项scRNA-seq研究的数据,定义一个全面的泛癌图谱,该图谱描绘了转录ITH的11个“标志”。现在越来越多的研究利用公共数据,通过大样本研究共性和规律,科研结果也需要大量的样本作为证据链,此类文章的分析策略显得尤为重要。从错综复杂的数据中,抽丝剥茧,找到共性“元件”。另外,研究团队需要前期大量的知识积累和总结,来解释共性结论的合理性。在研究此课题前,已经有某些猜想构思。未来,随着HuBMAP和HTAN等研究联盟深入研究,通过不同组学不同维度构建出泛癌图谱,对肿瘤的发生发展会有更清晰的认识。
Abstract:
Each tumour contains diverse cellular states that underlie intratumour heterogeneity (ITH), a central challenge of cancer therapeutics. Dozens of recent studies have begun to describe ITH by single-cell RNA sequencing, …
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Each tumour contains diverse cellular states that underlie intratumour heterogeneity (ITH), a central challenge of cancer therapeutics. Dozens of recent studies have begun to describe ITH by single-cell RNA sequencing, but each study typically profiled only a small number of tumours and provided a narrow view of transcriptional ITH. Here we curate, annotate and integrate the data from 77 different studies to reveal the patterns of transcriptional ITH across 1,163 tumour samples covering 24 tumour types. Among the malignant cells, we identify 41 consensus meta-programs, each consisting of dozens of genes that are coordinately upregulated in subpopulations of cells within many tumours. The meta-programs cover diverse cellular processes including both generic (for example, cell cycle and stress) and lineage-specific patterns that we map into 11 hallmarks of transcriptional ITH. Most meta-programs of carcinoma cells are similar to those identified in non-malignant epithelial cells, suggesting that a large fraction of malignant ITH programs are variable even before oncogenesis, reflecting the biology of their cell of origin. We further extended the meta-program analysis to six common non-malignant cell types and utilize these to map cell-cell interactions within the tumour microenvironment. In summary, we have assembled a comprehensive pan-cancer single-cell RNA-sequencing dataset, which is available through the Curated Cancer Cell Atlas website, and leveraged this dataset to carry out a systematic characterization of transcriptional ITH.
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330.
颜林林
(2023-08-30 08:09):
#paper doi:10.1016/j.crmeth.2023.100547. Cell Reports Methods, 2023, An introduction to representation learning for single-cell data analysis. 机器学习方法的效果常依赖于数据质量,也与所选择的特征(即数据的表示方法)有关,而表示学习(representation learning)能够通过模型自身去学习数据的表示,这在有足够数据的情况下是非常适合的。单细胞测序数据分析正好是这样一个场景。本文综述了单细胞测序数据分析各个环节(包括数据预处理、超参数优化、下游分析、生物学验证等)中,表示学习方法的应用及应注意的关键点。
IF:4.300Q2
Cell reports methods,
2023-08-28.
DOI: 10.1016/j.crmeth.2023.100547
PMID: 37671013
PMCID:PMC10475795
Abstract:
Single-cell-resolved systems biology methods, including omics- and imaging-based measurement modalities, generate a wealth of high-dimensional data characterizing the heterogeneity of cell populations. Representation learning methods are routinely used to analyze …
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Single-cell-resolved systems biology methods, including omics- and imaging-based measurement modalities, generate a wealth of high-dimensional data characterizing the heterogeneity of cell populations. Representation learning methods are routinely used to analyze these complex, high-dimensional data by projecting them into lower-dimensional embeddings. This facilitates the interpretation and interrogation of the structures, dynamics, and regulation of cell heterogeneity. Reflecting their central role in analyzing diverse single-cell data types, a myriad of representation learning methods exist, with new approaches continually emerging. Here, we contrast general features of representation learning methods spanning statistical, manifold learning, and neural network approaches. We consider key steps involved in representation learning with single-cell data, including data pre-processing, hyperparameter optimization, downstream analysis, and biological validation. Interdependencies and contingencies linking these steps are also highlighted. This overview is intended to guide researchers in the selection, application, and optimization of representation learning strategies for current and future single-cell research applications.
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331.
惊鸿
(2023-08-28 23:29):
#paper DOI : 10.7150/thno.82228 2023-06-12 Lipid nanoparticles-loaded with toxin mRNA represents a new strategy for the treatment of solid tumors.
癌症治疗在过去十年中取得了显着发展,提供了使用免疫调节抑制癌细胞生长的新策略,无论是否使用基因治疗。具体而言,已经研究了自杀基因疗法和免疫毒素通过直接癌细胞细胞毒性治疗肿瘤。mRNA递送的最新进展也证明了基于mRNA的疫苗和免疫调节剂通过利用纳米载体进行mRNA递送而具有癌症治疗的潜力。
Abstract:
: Cancer therapy have evolved remarkably over the past decade, providing new strategies to inhibit cancer cell growth using immune modulation, with or without gene therapy. Specifically, suicide gene therapies …
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: Cancer therapy have evolved remarkably over the past decade, providing new strategies to inhibit cancer cell growth using immune modulation, with or without gene therapy. Specifically, suicide gene therapies and immunotoxins have been investigated for the treatment of tumors by direct cancer cell cytotoxicity. Recent advances in mRNA delivery also demonstrated the potential of mRNA-based vaccines and immune-modulators for cancer therapeutics by utilizing nanocarriers for mRNA delivery. We designed a bacterial toxin-encoding modified mRNA, delivered by lipid nanoparticles into a B16-melanoma mouse model. : We showed that local administration of LNPs entrapping a modified mRNA that encodes for a bacterial toxin, induced significant anti-tumor effects and improved overall survival of treated mice. We propose mmRNA-loaded LNPs as a new class of anti-tumoral, toxin-based therapy.
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332.
李翛然
(2023-08-28 23:16):
#paper doi:10.1101/2023.07.27.550799v3.full.pdf
Context-Dependent Design of Induced-fit Enzymes using Deep Learning Generates Well Expressed,
Thermally Stable and Active Enzymes 这篇文章提出了一种新的酶设计方法:
提出了一种新的酶设计策略CoSaNN,利用深度学习结构预测模型AlphaFold来生成新酶的构象。这种方法考虑了氨基酸序列段落在不同构象环境下的折叠方式,可以更准确地预测嵌合序列的构象。
在序列优化设计阶段,该方法没有仅仅依赖RosettaDesign,而是同时采用了基于图神经网络的ProteinMPNN模型。 ProteinMPNN可以学习序列与构象之间的高阶非线性关系,生成更可折叠的序列。
额外训练了一个预测可溶性表达的图神经网络分类器SolvIT,作为酶设计流程中的另一层优化,提高高表达酶的生成概率。
在ROK糖激酶家族中,利用该方法成功设计了活性高、热稳定性强、高表达的新酶。一些设计的酶表现出比模板酶更好的催化特性。
该方法证明了深度学习模型可以捕捉复杂蛋白质的构象变化和序列关系,在保持催化活性和调节机制的同时实现大范围改造酶的结构。这为定向生物技术应用开辟了新的途径。
但是: 这个文章并没有提到,在activate site 不明确的情况下该如何设计酶,也就是说还是需要生物上探明了 activate site 再进行新的酶定向进化。
2023.
DOI: 10.1101/2023.07.27.550799
Abstract:
AbstractThe potential of engineered enzymes in practical applications is often constrained by limitations in their expression levels, thermal stability, and the diversity and magnitude of catalytic activities.De-novoenzyme design, though exciting, …
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AbstractThe potential of engineered enzymes in practical applications is often constrained by limitations in their expression levels, thermal stability, and the diversity and magnitude of catalytic activities.De-novoenzyme design, though exciting, is challenged by the complex nature of enzymatic catalysis. An alternative promising approach involves expanding the capabilities of existing natural enzymes to enable functionality across new substrates and operational parameters. To this end we introduce CoSaNN (Conformation Sampling using Neural Network), a novel strategy for enzyme design that utilizes advances in deep learning for structure prediction and sequence optimization. By controlling enzyme conformations, we can expand the chemical space beyond the reach of simple mutagenesis. CoSaNN uses a context-dependent approach that accurately generates novel enzyme designs by considering non-linear relationships in both sequence and structure space. Additionally, we have further developed SolvIT, a graph neural network trained to predict protein solubility inE.Coli, as an additional optimization layer for producing highly expressed enzymes. Through this approach, we have engineered novel enzymes exhibiting superior expression levels, with 54% of our designs expressed in E.Coli, and increased thermal stability with more than 30% of our designs having a higher Tm than the template enzyme. Furthermore, our research underscores the transformative potential of AI in protein design, adeptly capturing high order interactions and preserving allosteric mechanisms in extensively modified enzymes. These advancements pave the way for the creation of diverse, functional, and robust enzymes, thereby opening new avenues for targeted biotechnological applications.
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333.
Spring
(2023-08-28 21:20):
#paper doi: 10.1038/s41591-023-02497-z
First-line durvalumab and tremelimumab with chemotherapy in RAS-mutated metastatic colorectal cancer: a phase 1b/2 trial
① 57名RAS突变的不可切除转移性结直肠癌患者接受mFOLFOX6化疗联合durvalumab及tremelimumab治疗;② 48名微卫星稳定(MSS)患者中,3个月、6个月、12个月、24个月的无进展生存率分别为90.7%、60.4%、26.9%、6.7%,中位无进展生存期为8.2个月;③ 6个月、12个月、24个月的总生存率分别为95.8%、81.1%及57.6%,中位总生存期尚未达到;④ 完全应答率及部分应答率分别为12.5%及52%;⑤ 在应答者中可观察到高肿瘤突变负荷及低基因组稳定性。
Abstract:
Although patients with microsatellite instable metastatic colorectal cancer (CRC) benefit from immune checkpoint blockade, chemotherapy with targeted therapies remains the only therapeutic option for microsatellite stable (MSS) tumors. The single-arm, …
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Although patients with microsatellite instable metastatic colorectal cancer (CRC) benefit from immune checkpoint blockade, chemotherapy with targeted therapies remains the only therapeutic option for microsatellite stable (MSS) tumors. The single-arm, phase 1b/2 MEDITREME trial evaluated the safety and efficacy of durvalumab plus tremelimumab combined with mFOLFOX6 chemotherapy in first line, in 57 patients with RAS-mutant unresectable metastatic CRC. Safety was the primary objective of phase Ib; no safety issue was observed. The phase 2 primary objective of efficacy in terms of 3-month progression-free survival (PFS) in patients with MSS tumors was met, with 3-month PFS of 90.7% (95% confidence interval (CI): 79.2-96%). For secondary objectives, response rate was 64.5%; median PFS was 8.2 months (95% CI: 5.9-8.6); and overall survival was not reached in patients with MSS tumors. We observed higher tumor mutational burden and lower genomic instability in responders. Integrated transcriptomic analysis underlined that high immune signature and low epithelial-mesenchymal transition were associated with better outcome. Immunomonitoring showed induction of neoantigen and NY-ESO1 and TERT blood tumor-specific T cell response associated with better PFS. The combination of durvalumab-tremelimumab with mFOLFOX6 was tolerable with promising clinical activity in MSS mCRC. Clinicaltrials.gov identifier: NCT03202758 .
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334.
钟鸣
(2023-08-28 21:14):
#paper doi: 10.1128/iai.00154-23 The choline-binding proteins PspA, PspC, and LytA of Streptococcus pneumoniae and their interaction with human endothelial and red blood cells
这是关于肺炎链球菌毒力因子研究的最新文章,研究路线也比较基础,通过同源重组获得靶蛋白的突变体,紧接着测毒力形状,包括生物膜形成能力、细胞染毒后的代谢活性、对细胞的粘附性、溶血活性、对细胞中特定蛋白表达的影响等,最后使用string预测了蛋白互作网络。
Abstract:
is a Gram-positive opportunistic pathogen that can colonize the upper respiratory tract. It is a leading cause of a wide range of infectious diseases, including community-acquired pneumonia and meningitis. Pneumococcal …
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is a Gram-positive opportunistic pathogen that can colonize the upper respiratory tract. It is a leading cause of a wide range of infectious diseases, including community-acquired pneumonia and meningitis. Pneumococcal infections cause 1-2 million deaths per year, most of which occur in developing countries. Here, we focused on three choline-binding proteins (CBPs), i.e., PspC, PspA, and LytA. These pneumococcal proteins have different surface-exposed regions but share related choline-binding anchors. These surface-exposed pneumococcal proteins are in direct contact with host cells and have diverse functions. We explored the role of the three CBPs on adhesion and pathogenicity in a human host by performing relevant imaging and functional analyses, such as electron microscopy, confocal laser scanning microscopy, and functional quantitative assays, targeting biofilm formation and the hemolytic capacity of . biofilm formation assays and electron microscopy experiments were used to examine the ability of knockout mutant strains lacking the lytA, pspC, or pspA genes to adhere to surfaces. We found that LytA plays an important role in robust synthesis of the biofilm matrix. PspA and PspC appeared crucial for the hemolytic effects of on human red blood cells. Furthermore, all knockout mutants caused less damage to endothelial cells than wild-type bacteria, highlighting the significance of each CPB for the overall pathogenicity of . Hence, in addition to their structural function within the cell wall of , each of these three surface-exposed CBPs controls or mediates multiple steps during bacterial pathogenesis.
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335.
龙海晨
(2023-08-24 13:14):
#paper Fairley JA, Cheetham MH, Patton SJ, Rouleau E, Denis M, Dequeker EMC, Schuuring E, van Casteren K, Fenizia F, Normanno N, Deans ZC. Results of a worldwide external quality assessment of cfDNA testing in lung Cancer. BMC Cancer. 2022 Jul 12;22(1):759. doi: 10.1186/s12885-022-09849-x. PMID: 35820813; PMCID: PMC9275131. 文章是对世界范围内用cfDNA检测肺癌的进行质量评估。45个国家304家注册实验室中有264个实验室提交了结果。排除无法从人造血浆中提取DNA的实验室,大多数实验室获得了准确的结果,对于不同的基因突变采用不同的检测手段准确率不同。实验证明了CFDNA检测肺癌的可行性。
Abstract:
BACKGROUND: Circulating cell free DNA (cfDNA) testing of plasma for EGFR somatic variants in lung cancer patients is being widely implemented and with any new service, external quality assessment (EQA) …
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BACKGROUND: Circulating cell free DNA (cfDNA) testing of plasma for EGFR somatic variants in lung cancer patients is being widely implemented and with any new service, external quality assessment (EQA) is required to ensure patient safety. An international consortium, International Quality Network for Pathology (IQNPath), has delivered a second round of assessment to measure the accuracy of cfDNA testing for lung cancer and the interpretation of the results.METHODS: A collaboration of five EQA provider organisations, all members of IQNPath, have delivered the assessment during 2018-19 to a total of 264 laboratories from 45 countries. Bespoke plasma reference material containing a range of EGFR mutations at varying allelic frequencies were supplied to laboratories for testing and reporting according to routine procedures. The genotyping accuracy and clinical reporting was reviewed against standardised criteria and feedback was provided to participants.RESULTS: The overall genotyping error rate in the EQA was found to be 11.1%. Low allelic frequency samples were the most challenging and were not detected by some testing methods, resulting in critical genotyping errors. This was reflected in higher false negative rates for samples with variant allele frequencies (VAF) rates less than 1.5% compared to higher frequencies. A sample with two different EGFR mutations gave inconsistent detection of both mutations. However, for one sample, where two variants were present at a VAF of less than 1% then both mutations were correctly detected in 145/263 laboratories. Reports often did not address the risk that tumour DNA may have not been tested and limitations of the methodologies provided by participants were insufficient. This was reflected in the average interpretation score for the EQA being 1.49 out of a maximum of 2.CONCLUSIONS: The variability in the standard of genotyping and reporting highlighted the need for EQA and educational guidance in this field to ensure the delivery of high-quality clinical services where testing of cfDNA is the only option for clinical management.
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336.
DeDe宝
(2023-08-20 15:47):
#paper doi:10.1038/s41597-023-02449-9 Nature Scientific Data,2023,Release of cognitive and multimodal MRI data including real-world tasks and hippocampal subfield segmentations 这篇研究介绍了一个包含217名健康成年人(平均年龄 29 岁,范围 20-41;109 名女性,108 名男性)的数据集,数据集包含3T的MRI数据(包括多参数图检查组织微结构、扩散加权MRI、T2加权高分辨部分容积结构MRI扫描、全脑静息态功能MRI扫描和部分容积高分辨静息态功能MRI扫描)和大量认知评估问卷和行为实验。该数据集对认知和临床心理学的研究者,尤其是关注海马脑区的研究者有用,其中的认知测试和问卷也具有一定的参考意义。所有数据均可在 Dryad 上免费获取。
Abstract:
We share data from N = 217 healthy adults (mean age 29 years, range 20-41; 109 females, 108 males) who underwent extensive cognitive assessment and neuroimaging to examine the neural …
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We share data from N = 217 healthy adults (mean age 29 years, range 20-41; 109 females, 108 males) who underwent extensive cognitive assessment and neuroimaging to examine the neural basis of individual differences, with a particular focus on a brain structure called the hippocampus. Cognitive data were collected using a wide array of questionnaires, naturalistic tests that examined imagination, autobiographical memory recall and spatial navigation, traditional laboratory-based tests such as recalling word pairs, and comprehensive characterisation of the strategies used to perform the cognitive tests. 3 Tesla MRI data were also acquired and include multi-parameter mapping to examine tissue microstructure, diffusion-weighted MRI, T2-weighted high-resolution partial volume structural MRI scans (with the masks of hippocampal subfields manually segmented from these scans), whole brain resting state functional MRI scans and partial volume high resolution resting state functional MRI scans. This rich dataset will be of value to cognitive and clinical neuroscientists researching individual differences, real-world cognition, brain-behaviour associations, hippocampal subfields and more. All data are freely available on Dryad.
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337.
徐炳祥
(2023-08-14 21:58):
#paper doi: 10.1016/j.chembiol.2023.07.001 Cell Chemical Biology, 2023, Small molecule targeting of transcription-replication conflict for selective chemotherapy。本文是最近肿瘤治化疗领域内的一项重要新闻,作者在之前研究的基础上设计了一种新的小分子药物AOH1996,该药物通过增强PCNA与RPB1的结合从而将PCNA带离染色质,进而引起伴随转录的DNA复制抑制和不能被修复的DNA双链断裂损伤。通过此机制,AOH1996实现了对癌细胞的特异性杀灭,而对正常细胞几乎无毒性。动物实验和细胞实验均证明单独使用AOH1996或与其他药物联合对大部分实体肿瘤均有或多或少的疗效。本文再一次展现了针对DNA损伤修复机制的抗肿瘤药物设计的潜力。
Abstract:
Targeting transcription replication conflicts, a major source of endogenous DNA double-stranded breaks and genomic instability could have important anticancer therapeutic implications. Proliferating cell nuclear antigen (PCNA) is critical to DNA …
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Targeting transcription replication conflicts, a major source of endogenous DNA double-stranded breaks and genomic instability could have important anticancer therapeutic implications. Proliferating cell nuclear antigen (PCNA) is critical to DNA replication and repair processes. Through a rational drug design approach, we identified a small molecule PCNA inhibitor, AOH1996, which selectively kills cancer cells. AOH1996 enhances the interaction between PCNA and the largest subunit of RNA polymerase II, RPB1, and dissociates PCNA from actively transcribed chromatin regions, while inducing DNA double-stranded breaks in a transcription-dependent manner. Attenuation of RPB1 interaction with PCNA, by a point mutation in RPB1's PCNA-binding region, confers resistance to AOH1996. Orally administrable and metabolically stable, AOH1996 suppresses tumor growth as a monotherapy or as a combination treatment but causes no discernable side effects. Inhibitors of transcription replication conflict resolution may provide a new and unique therapeutic avenue for exploiting this cancer-selective vulnerability.
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338.
AI 5.0.3
(2023-08-01 00:05):
#paper https://doi.org/10.1126/scitranslmed.aba2913 Neurodevelopment and risk for ADHD and depression 7 岁时背侧前额叶皮层和内侧前额叶皮层之间的积极功能连通性较弱与11岁时ADHD症状的减少有关,而背侧前额叶皮层和亚属前扣带皮层之间的积极功能连通性较弱与11岁时情绪相关症状的增加有关。7岁时的大脑连通性比11岁时预测的情绪相关困难比基线症状本身更好,这在具有家庭抑郁症风险的独立样本中得到验证。虽然预测模型需要在更大的独立样本中进行测试,但这些结果表明连接模式作为症状轨迹的生物标志物的潜在效用。
339.
林海onrush
(2023-08-01 00:03):
#paper,doi.org/10.1016/j.aim.2023.109194,Equivariant algebraic K-theory, G-theory and
derived completions,论文研究的是群作用下的代数K理论的补全问题。主要内容可概括如下:
文章主要研究线性代数群作用在方案上的等ivariant代数K理论和G理论。目标是证明一个类似Atiyah-Segal在拓扑K理论中补全定理的结果。衍生补全的技术对此问题非常关键。Thomason在80年代就预测到需要一种同伦类的补全方法。本文使用第一作者2008年提出的衍生补全方法。Robert Thomason在建立与Atiyah-Segal对应的等变代数K理论的完备性定理时,发现了强限制性条件过于严格。他对等变代数G理论的情况提出了一个猜想,即对于线性代数群在概型上的作用,存在一个类似Atiyah和Segal的完备性定理,而不需要他之前证明的强限制性条件,这些条件也出现在原始的Atiyah-Segal定理中。
本文的主要目标是在尽可能广泛的背景下,利用导出完备性技术,对该猜想进行证明,并考虑几个应用。解决方案足够广泛,允许所有线性代数群的作用,无论它们是否连通,并作用于任何有限型域上的准投影概型,无论它们是否正则或投影。因此,可以考虑大类的变体的等变代数G理论,例如所有的齐次概型(由一个齐次环作用的情况)和所有球状概型(由一个约化群作用的情况)。通过限制为分裂齐次概型的作用,还可以考虑对代数空间的作用。此外,通常也不需要将基概型限制为域,但主要是为了简化部分阐述。这使得可以得到广泛的应用,其中一些被简要概述,并计划在将来详细探讨。实际上,我们在续篇中讨论了将结果扩展到等变同伦K理论以及各种Riemann-Roch定理。
通过将结果与先前已知的没有使用导出完备性的结果进行比较,可以看出如果不使用导出完备性,只能得到非常限制性的结果。
Abstract:
In the mid 1980s, while working on establishing completion theorems for equivariant Algebraic K-Theory similar to the well-known Atiyah-Segal completion theorem for equivariant topological K-theory, the late Robert Thomason found …
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In the mid 1980s, while working on establishing completion theorems for equivariant Algebraic K-Theory similar to the well-known Atiyah-Segal completion theorem for equivariant topological K-theory, the late Robert Thomason found the strong finiteness conditions that are required in such theorems to be too restrictive. Then he made a conjecture on the existence of a completion theorem in the sense of Atiyah and Segal for equivariant algebraic G-theory, for actions of linear algebraic groups on schemes that holds without any of the strong finiteness conditions that are required in such theorems proven by him, and also appearing in the original Atiyah-Segal theorem. The main goal of the present paper is to provide a proof of this conjecture in as broad a context as possible, making use of the technique of derived completion, and to consider several of the applications. Our solution is broad enough to allow actions by all linear algebraic groups, irrespective of whether they are connected or not, and acting on any quasi-projective scheme of finite type over a field, irrespective of whether they are regular or projective. This allows us therefore to consider the equivariant algebraic G-Theory of large classes of varieties like all toric varieties (for the action of a torus) and all spherical varieties (for the action of a reductive group). Restricting to actions by split tori, we are also able to consider actions on algebraic spaces. Moreover, the restriction that the base scheme be a field is also not required often, but is put in mainly to simplify some of our exposition. These enable us to obtain a wide range of applications, some of which are briefly sketched and which we plan to explore in detail in the future. In fact, we discuss an extension of our results to equivariant homotopy K-theory along with various Riemann-Roch theorems in a sequel. A comparison of our results with previously known results, none of which made use of derived completions, shows that without the use of derived completions one can only obtain results which are indeed very restrictive.
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340.
小W
(2023-07-31 23:45):
#paper doi:https://doi.org/10.1038/s41591-023-02429-x A multi-ancestry polygenic risk score improves risk prediction for coronary artery disease
本文使用不同祖先来源人群队列的 冠状动脉疾病(CAD) GWASs分析结果,开发了 CAD 多基因风险评分模型(gps) GPSMult ,用于识别 CAD 风险。其模型分为两层:1.使用LDpred2方法为每个群体分层CAD GWAS构建单独的gps, ,综合 不同群体间gps 构建多祖先来源模型;2.采用步进法选择多祖先gps + 临床性状 的最佳组合,构建逻辑回归模型 GPSMult 。本文验证了GPSMult模型 相对于已发布的CAD风险模型在年轻人群或非欧洲人群风险预测性能的提升,倡导GPSMult辅助指导处于边缘或中度CAD风险个体的他汀类药物治疗决策。
Abstract:
Identification of individuals at highest risk of coronary artery disease (CAD)-ideally before onset-remains an important public health need. Prior studies have developed genome-wide polygenic scores to enable risk stratification, reflecting …
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Identification of individuals at highest risk of coronary artery disease (CAD)-ideally before onset-remains an important public health need. Prior studies have developed genome-wide polygenic scores to enable risk stratification, reflecting the substantial inherited component to CAD risk. Here we develop a new and significantly improved polygenic score for CAD, termed GPS, that incorporates genome-wide association data across five ancestries for CAD (>269,000 cases and >1,178,000 controls) and ten CAD risk factors. GPS strongly associated with prevalent CAD (odds ratio per standard deviation 2.14, 95% confidence interval 2.10-2.19, P < 0.001) in UK Biobank participants of European ancestry, identifying 20.0% of the population with 3-fold increased risk and conversely 13.9% with 3-fold decreased risk as compared with those in the middle quintile. GPS was also associated with incident CAD events (hazard ratio per standard deviation 1.73, 95% confidence interval 1.70-1.76, P < 0.001), identifying 3% of healthy individuals with risk of future CAD events equivalent to those with existing disease and significantly improving risk discrimination and reclassification. Across multiethnic, external validation datasets inclusive of 33,096, 124,467, 16,433 and 16,874 participants of African, European, Hispanic and South Asian ancestry, respectively, GPS demonstrated increased strength of associations across all ancestries and outperformed all available previously published CAD polygenic scores. These data contribute a new GPS for CAD to the field and provide a generalizable framework for how large-scale integration of genetic association data for CAD and related traits from diverse populations can meaningfully improve polygenic risk prediction.
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