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501.
小年
(2023-09-01 00:00):
#paper https://doi.org/10.1038/sdata.2018.157 A tissue-based draft map of the murine MHC class I immunopeptidome 文章介绍了一个关于小鼠MHC I类免疫肽组的组织图谱,其中包含了19种正常组织中呈现给CD8+ T细胞的肽段的全面概述。方法总结如下:
1. 得到质谱下机数据。
2. 使用Msconvert将原始质谱数据转换为mzML格式。
3. 使用Comet、MS-GF+和XTandem等数据库搜索引擎,将mzML格式的数据与小鼠蛋白质数据库进行比对,以鉴定肽段。
4. 使用Prophets进行统计验证,以确定鉴定的肽段的置信度。
5. 使用GibbsCluster v.1对鉴定的肽段进行聚类分析,以确定具有相似质谱特征的肽段。
6. 使用NetMHC v.4对鉴定的肽段进行注释分析,以确定其长度和预测MHC结合亲和力。
7. 根据统计验证和注释分析的结果,筛选出高置信度的MHC相关肽段。
8. 使用高置信度的MHC相关肽段,构建高质量的H2D b/K b特异性肽段光谱和测定库。
9. 将构建的肽段光谱和测定库共享到SysteMHC Atlas和SWATH Atlas中,以便其他研究人员可以使用和分析这些数据。
10. 最终的结果呈现,包括肽段光谱和测定库的构建、MHC相关肽段的注释和筛选等。
Abstract:
The large array of peptides presented to CD8+ T cells by major histocompatibility complex (MHC) class I molecules is referred to as the MHC class I immunopeptidome. Although the MHC …
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The large array of peptides presented to CD8+ T cells by major histocompatibility complex (MHC) class I molecules is referred to as the MHC class I immunopeptidome. Although the MHC class I immunopeptidome is ubiquitous in mammals and represents a critical component of the immune system, very little is known, in any species, about its composition across most tissues and organs in vivo. We applied mass spectrometry (MS) technologies to draft the first tissue-based atlas of the murine MHC class I immunopeptidome in health. Peptides were extracted from 19 normal tissues from C57BL/6 mice and prepared for MS injections, resulting in a total number of 28,448 high-confidence H2D/K-associated peptides identified and annotated in the atlas. This atlas provides initial qualitative data to explore the tissue-specificity of the immunopeptidome and serves as a guide to identify potential tumor-associated antigens from various cancer models. Our data were shared via PRIDE (PXD008733), SysteMHC Atlas (SYSMHC00018) and SWATH Atlas. We anticipate that this unique dataset will be expanded in the future and will find wide applications in basic and translational immunology.
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502.
林海onrush
(2023-09-01 00:00):
#paper,Supervised machine learning classification of psychosis biotypes based on brain structure: findings from the Bipolar-Schizophrenia network for intermediate phenotypes (B-SNIP),https://doi.org/10.1038/s41598-023-38101-0讨论了精神障碍的传统诊断方法与神经生物学关联的不足,并提出了使用基于大脑的生物标志物来捕获精神病结构的方法。研究以基于MRI图像的灰质密度(GMD)作为生物标志物,通过逻辑回归模型将精神病病例与健康对照进行分类。在不同生物型和诊断方案下,研究评估了六个模型的分类准确性,其中B1生物型模型显示了特异性证据,能够有效区分精神病病例和健康对照。基于GMD的B1分类器结果显示,其与病前智力负相关。研究结果表明,基于B-SNIP精神病生物型的方法可能是捕捉精神病神经生物学特征的有前途方法,并可辅助临床诊断。最近个人也在一直思考如何把脑科学神经科学的东西和量子计算结合研究,下来多读一读脑科学相关文献
Abstract:
Traditional diagnostic formulations of psychotic disorders have low correspondence with underlying disease neurobiology. This has led to a growing interest in using brain-based biomarkers to capture biologically-informed psychosis constructs. Building …
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Traditional diagnostic formulations of psychotic disorders have low correspondence with underlying disease neurobiology. This has led to a growing interest in using brain-based biomarkers to capture biologically-informed psychosis constructs. Building upon our prior work on the B-SNIP Psychosis Biotypes, we aimed to examine whether structural MRI (an independent biomarker not used in the Biotype development) can effectively classify the Biotypes. Whole brain voxel-wise grey matter density (GMD) maps from T1-weighted images were used to train and test (using repeated randomized train/test splits) binary L2-penalized logistic regression models to discriminate psychosis cases (n = 557) from healthy controls (CON, n = 251). A total of six models were evaluated across two psychosis categorization schemes: (i) three Biotypes (B1, B2, B3) and (ii) three DSM diagnoses (schizophrenia (SZ), schizoaffective (SAD) and bipolar (BD) disorders). Above-chance classification accuracies were observed in all Biotype (B1 = 0.70, B2 = 0.65, and B3 = 0.56) and diagnosis (SZ = 0.64, SAD = 0.64, and BD = 0.59) models. However, the only model that showed evidence of specificity was B1, i.e., the model was able to discriminate B1 vs. CON and did not misclassify other psychosis cases (B2 or B3) as B1 at rates above nominal chance. The GMD-based classifier evidence for B1 showed a negative association with an estimate of premorbid general intellectual ability, regardless of group membership, i.e. psychosis or CON. Our findings indicate that, complimentary to clinical diagnoses, the B-SNIP Psychosis Biotypes may offer a promising approach to capture specific aspects of psychosis neurobiology.
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503.
笑对人生
(2023-08-31 23:55):
#paper Li J, et al. Non-cell-autonomous cancer progression from chromosomal instability. Nature. 2023 Aug;620(7976):1080-1088. doi: 10.1038/s41586-023-06464-z. Epub 2023 Aug 23. PMID: 37612508.
染色体不稳定(chromosomal instability,CIN)是癌症的基本特征之一,与治疗耐药、免疫逃逸和转移密切相关。CIN的形成始于细胞有丝分裂过程中染色体的持续性的错误分离。先前该团队的研究表明(Samuel F Bakhoum, et al. nature, 2018),CIN通过诱发cCAS-STING先天免疫信号通路介导的胞质双链DNA感应来促进肿瘤细胞转移。然而,关于CIN对肿瘤进展的影响究竟是肿瘤细胞自发的,还是依赖于免疫系统的问题,以及染色体不稳定肿瘤适应CIN和逃避免疫监视的具体机制是什么,目前仍未知。本研究通过四种相同遗传背景的肿瘤转移小鼠模型,首先证实了CIN是通过肿瘤细胞非自发机制驱动转移的发生。其次,开发了一个名为ContactTracing的单细胞转录组细胞互作工具,发现CIN引发的cGAS-STNG信号通路慢性激活,会促进下游I型干扰素的快速应答和内质网应激增加,最终导致促转移的肿瘤微环境形成。进一步的挽救实验(CIN逆转、STNG缺失和内质网抑制)和使用STING抑制剂处理细胞实验也支持这一结论。
Abstract:
Chromosomal instability (CIN) is a driver of cancer metastasis, yet the extent to which this effect depends on the immune system remains unknown. Using ContactTracing-a newly developed, validated and benchmarked …
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Chromosomal instability (CIN) is a driver of cancer metastasis, yet the extent to which this effect depends on the immune system remains unknown. Using ContactTracing-a newly developed, validated and benchmarked tool to infer the nature and conditional dependence of cell-cell interactions from single-cell transcriptomic data-we show that CIN-induced chronic activation of the cGAS-STING pathway promotes downstream signal re-wiring in cancer cells, leading to a pro-metastatic tumour microenvironment. This re-wiring is manifested by type I interferon tachyphylaxis selectively downstream of STING and a corresponding increase in cancer cell-derived endoplasmic reticulum (ER) stress response. Reversal of CIN, depletion of cancer cell STING or inhibition of ER stress response signalling abrogates CIN-dependent effects on the tumour microenvironment and suppresses metastasis in immune competent, but not severely immune compromised, settings. Treatment with STING inhibitors reduces CIN-driven metastasis in melanoma, breast and colorectal cancers in a manner dependent on tumour cell-intrinsic STING. Finally, we show that CIN and pervasive cGAS activation in micronuclei are associated with ER stress signalling, immune suppression and metastasis in human triple-negative breast cancer, highlighting a viable strategy to identify and therapeutically intervene in tumours spurred by CIN-induced inflammation.
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504.
大勇
(2023-08-31 23:51):
#paper Correia, A.L., Guimaraes, J.C., Auf der Maur, P. et al. Hepatic stellate cells suppress NK cell-sustained breast cancer dormancy. Nature 594, 566-571 (2021). https://doi.org/10.1038/s41586-021-03614-z 该文章主要讲述的是乳腺癌肝转移时存在着休眠期细胞,党癌细胞的休眠期解除时,则会引起癌细胞的复发和转移,乳腺癌在肝脏的休眠过程可能由NK细胞分泌IFNγ来维持,而当肝脏星形细胞分泌CXCL12抑制NK细胞时,则会解除这个状态,使休眠细胞继续激活扩增。
Abstract:
The persistence of undetectable disseminated tumour cells (DTCs) after primary tumour resection poses a major challenge to effective cancer treatment. These enduring dormant DTCs are seeds of future metastases, and …
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The persistence of undetectable disseminated tumour cells (DTCs) after primary tumour resection poses a major challenge to effective cancer treatment. These enduring dormant DTCs are seeds of future metastases, and the mechanisms that switch them from dormancy to outgrowth require definition. Because cancer dormancy provides a unique therapeutic window for preventing metastatic disease, a comprehensive understanding of the distribution, composition and dynamics of reservoirs of dormant DTCs is imperative. Here we show that different tissue-specific microenvironments restrain or allow the progression of breast cancer in the liver-a frequent site of metastasis that is often associated with a poor prognosis. Using mouse models, we show that there is a selective increase in natural killer (NK) cells in the dormant milieu. Adjuvant interleukin-15-based immunotherapy ensures an abundant pool of NK cells that sustains dormancy through interferon-γ signalling, thereby preventing hepatic metastases and prolonging survival. Exit from dormancy follows a marked contraction of the NK cell compartment and the concurrent accumulation of activated hepatic stellate cells (aHSCs). Our proteomics studies on liver co-cultures implicate the aHSC-secreted chemokine CXCL12 in the induction of NK cell quiescence through its cognate receptor CXCR4. CXCL12 expression and aHSC abundance are closely correlated in patients with liver metastases. Our data identify the interplay between NK cells and aHSCs as a master switch of cancer dormancy, and suggest that therapies aimed at normalizing the NK cell pool might succeed in preventing metastatic outgrowth.
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505.
Vincent
(2023-08-31 23:50):
#paper https://doi.org/10.48550/arXiv.2306.03301. arxiv 2023, Estimating Conditional Mutual Information for Dynamic Feature Selection. 动态特征选择涉及到学习特征选择策略,以及使用任意特征对目标值进行预测。其中学习选择策略往往十分具有挑战性。这篇文章介绍了一种基于特征与预测目标的条件互信息(conditional mutual information)对特征进行优先级排序,该方法通过训练一个神经网络估算在给定特征集情况下,其他特征的预测能力(条件互信息),每一步选择最具信息的特征加入到已有特征集中。依次迭代下去直到满足停止条件(例如达到给定特征数量,不确定度,代价等)。此外,该框架同样能够利用先验信息。文章验证了该方法在表格与图像数据集测试中均有不错效果。
arXiv,
2023.
DOI: 10.48550/arXiv.2306.03301
Abstract:
Dynamic feature selection, where we sequentially query features to make accurate predictions with a minimal budget, is a promising paradigm to reduce feature acquisition costs and provide transparency into the …
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Dynamic feature selection, where we sequentially query features to make accurate predictions with a minimal budget, is a promising paradigm to reduce feature acquisition costs and provide transparency into the prediction process. The problem is challenging, however, as it requires both making predictions with arbitrary feature sets and learning a policy to identify the most valuable selections. Here, we take an information-theoretic perspective and prioritize features based on their mutual information with the response variable. The main challenge is learning this selection policy, and we design a straightforward new modeling approach that estimates the mutual information in a discriminative rather than generative fashion. Building on our learning approach, we introduce several further improvements: allowing variable feature budgets across samples, enabling non-uniform costs between features, incorporating prior information, and exploring modern architectures to handle partial input information. We find that our method provides consistent gains over recent state-of-the-art methods across a variety of datasets.
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506.
小擎子
(2023-08-31 23:40):
#paper doi:10.1158/2159-8290.CD-21-0324 Cancer Discov,2022, The Cancer Microbiome: Recent Highlights and Knowledge Gaps 癌症微生物组 最近的亮点和知识空白。提出了微生物影响癌症进程的几种模型,微生物参与肿瘤发生的几种理论,网罗了各种癌症与微生物关系的相关报道。癌症微生物可能会帮助未来的早期癌症诊断。有一个比较有意思的,奈瑟属酒精脱氢酶发达,乳酸杆菌RA 可以将乙醛代谢为无毒模式。饮酒会引起奈瑟属升高,乳酸杆菌RA减少。但是口腔鳞癌(与酒精损伤有关)里没有观察到这个现象,文献观点认为这是早期微生物因素驱动或者影响了口腔鳞癌的发展,但后期检测不到,属于机制中的肇事逃逸模型。
Abstract:
Knowledge of the human microbiome, which is likely a critical factor in the initiation, progression, and prognosis of multiple forms of cancer, is rapidly expanding. In this review, we focus …
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Knowledge of the human microbiome, which is likely a critical factor in the initiation, progression, and prognosis of multiple forms of cancer, is rapidly expanding. In this review, we focus on recent investigations to discern putative, causative microbial species and the microbiome composition and structure currently associated with procarcinogenesis and tumorigenesis at select body sites. We specifically highlight forms of cancer, gastrointestinal and nongastrointestinal, that have significant bacterial associations and well-defined experimental evidence with the aim of generating directions for future experimental and translational investigations to develop a clearer understanding of the multifaceted mechanisms by which microbiota affect cancer formation. SIGNIFICANCE: Emerging and, for some cancers, strong experimental and translational data support the contribution of the microbiome to cancer biology and disease progression. Disrupting microbiome features and pathways contributing to cancer may provide new approaches to improving cancer outcomes in patients.
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507.
庞庞
(2023-08-31 23:18):
#Paper Disrupted intrinsic functional brain topology in patients with major depressive disorder DOI:10.1038/s41380-021-01247-2 作者解决了因为样本量过少抑郁症异常脑机制研究不一致的问题,发现,与NC相比,MDD患者的全局和局部效率降低。在节点水平上,MDD患者的特征是感觉运动网络(SMN)、背侧注意网络(DAN)和视觉网络(VN)的节点度降低,默认模式网络(DMN)、SMN、DAN和VN的节点效率降低。
Abstract:
AbstractAberrant topological organization of whole-brain networks has been inconsistently reported in studies of patients with major depressive disorder (MDD), reflecting limited sample sizes. To address this issue, we utilized a …
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AbstractAberrant topological organization of whole-brain networks has been inconsistently reported in studies of patients with major depressive disorder (MDD), reflecting limited sample sizes. To address this issue, we utilized a big data sample of MDD patients from the REST-meta-MDD Project, including 821 MDD patients and 765 normal controls (NCs) from 16 sites. Using the Dosenbach 160 node atlas, we examined whole-brain functional networks and extracted topological features (e.g., global and local efficiency, nodal efficiency, and degree) using graph theory-based methods. Linear mixed-effect models were used for group comparisons to control for site variability; robustness of results was confirmed (e.g., multiple topological parameters, different node definitions, and several head motion control strategies were applied). We found decreased global and local efficiency in patients with MDD compared to NCs. At the nodal level, patients with MDD were characterized by decreased nodal degrees in the somatomotor network (SMN), dorsal attention network (DAN) and visual network (VN) and decreased nodal efficiency in the default mode network (DMN), SMN, DAN, and VN. These topological differences were mostly driven by recurrent MDD patients, rather than first-episode drug naive (FEDN) patients with MDD. In this highly powered multisite study, we observed disrupted topological architecture of functional brain networks in MDD, suggesting both locally and globally decreased efficiency in brain networks.
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508.
muton
(2023-08-31 23:17):
#paper Multiple routes to enhanced memory for emotionally relevant events https://doi.org/10.1016/j.tics.2023.06.006令人厌恶的负性事件或奖赏有关的正性事件会被记得更好。这种记忆力的增强通常是因为引发了情感反应,这一过程与去甲肾上腺素和多巴胺调节的海马可塑性密切相关。最新发现表明预期偏差是上述事件会被记得更好的原因。在“预测”机制中,记忆会随着结果偏离预期的程度(即预测误差(PE)而得到加强)。 PE 对记忆的影响与情感结果本身是分开的,并且具有独特的神经特征。虽然这两种途径都能增强记忆,但两种机制会预测不同(有时甚至是相反)记忆整合的结果。文章讨论的一些新的研究结果强调了情绪事件增强、整合和分割记忆的机制。
Abstract:
Events associated with aversive or rewarding outcomes are prioritized in memory. This memory boost is commonly attributed to the elicited affective response, closely linked to noradrenergic and dopaminergic modulation of …
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Events associated with aversive or rewarding outcomes are prioritized in memory. This memory boost is commonly attributed to the elicited affective response, closely linked to noradrenergic and dopaminergic modulation of hippocampal plasticity. Herein we review and compare this 'affect' mechanism to an additional, recently discovered, 'prediction' mechanism whereby memories are strengthened by the extent to which outcomes deviate from expectations, that is, by prediction errors (PEs). The mnemonic impact of PEs is separate from the affective outcome itself and has a distinct neural signature. While both routes enhance memory, these mechanisms are linked to different - and sometimes opposing - predictions for memory integration. We discuss new findings that highlight mechanisms by which emotional events strengthen, integrate, and segment memory.
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509.
Ricardo
(2023-08-31 22:41):
#paper Brain Templates for Chinese Babies from Newborn to Three Months of Age doi: https://doi.org/10.1101/2023.06.05.543553 港中文最近挂在bioRxiv的一篇中国婴幼儿脑模板的文章,不过年龄范围局限在0-3月龄,图像质量不是很高。而且受限于脑影像预处理算法的问题,他们构建出来的婴幼儿分月龄模板比较粗糙,还不够精细。不过这也是没有办法的事,一方面是婴幼儿脑影像的数据采集确实是比较麻烦的事,另一方面针对早期发育阶段的婴幼儿脑影像处理算法也比较少,近期开源的也只有UNC那边开源的刚开始用起来。总之这个领域在国内还比较新。
2023.
DOI: 10.1101/2023.06.05.543553
Abstract:
AbstractThe infant brain develops rapidly and this area of research has great clinical implications. Neurodevelopmental disorders such as autism and developmental delay have their origins, potentially, in abnormal early brain …
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AbstractThe infant brain develops rapidly and this area of research has great clinical implications. Neurodevelopmental disorders such as autism and developmental delay have their origins, potentially, in abnormal early brain maturation. Searching for potential early neural markers requiresa prioriknowledge about infant brain development and anatomy. One of the most common methods of characterizing brain features requires normalization of individual images into a standard stereotactic space and conduct of group-based analyses in this space. A population representative brain template is critical for these population-based studies. Little research is available on constructing brain templates for typical developing Chinese infants. In the present work, a total of 112 babies from 6 to 98 days of age were included with high resolution structural magnetic resonance imaging scans. T1-weighted and T2-weighted templates were constructed using an unbiased registration approach for babies from newborn to 3 months of age. Age-specific templates were also estimated for babies aged at 0, 1, 2 and 3 months old. Then we conducted a series of evaluations and statistical analyses over whole tissue segmentations and brain parcellations. Compared to the use of population mismatched templates, using our established templates resulted in lower deformation energy to transform individual images into the template space and produced a smaller registration error, i.e., smaller standard deviation of the registered images. Significant volumetric growth was observed across total brain tissues and most of the brain regions within the first three months of age. The total brain tissues exhibited larger volumes in baby boys compared to baby girls. To the best of our knowledge, this is the first study focusing on the construction of Chinese infant brain templates. These templates can be used for investigating birth related conditions such as preterm birth, detecting neural biomarkers for neurological and neurodevelopmental disorders in Chinese populations, and exploring genetic and cultural effects on the brain.
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510.
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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511.
符毓
(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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512.
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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513.
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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514.
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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515.
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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516.
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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517.
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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518.
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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519.
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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520.
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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