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481.
徐炳祥
(2023-03-30 13:13):
#paper doi: 10.1101/gad.333708.119. Genes Dev, 2020, Upon microbial challenge, human neutrophils undergo rapid changes in nuclear architecture and chromatin folding to orchestrate an immediate inflammatory gene program。中性粒细胞免疫应答过程中伴随着核型和染色质构象的剧烈变化,这些变化与免疫应答诱导的转录调控过程之间的关系尚不清楚。本文使用人类中性粒细胞为实验材料,以PMA和大肠杆菌为刺激源诱发免疫反应,以Hi-C测定应答前后的染色质空间构象并进行比较。结果显示,应答之前,炎性基因处于转录抑制的空间构象中,应答后这些基因所在区域发生常染色质化,由核周进入核内部,并与增强子靠近,这些过程与应答过程中转录的快速响应有关。这些染色质构象的重排可能是由cohesin驱动的。本研究处理时长已达3h,但仍未见染色质构象的大范围改变。这些结论提示虽然染色质构象的全基因组重构是罕见事件,其局部的改变依然有研究的价值。
Abstract:
Differentiating neutrophils undergo large-scale changes in nuclear morphology. How such alterations in structure are established and modulated upon exposure to microbial agents is largely unknown. Here, we found that prior …
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Differentiating neutrophils undergo large-scale changes in nuclear morphology. How such alterations in structure are established and modulated upon exposure to microbial agents is largely unknown. Here, we found that prior to encounter with bacteria, an armamentarium of inflammatory genes was positioned in a transcriptionally passive environment suppressing premature transcriptional activation. Upon microbial exposure, however, human neutrophils rapidly (<3 h) repositioned the ensemble of proinflammatory genes toward the transcriptionally permissive compartment. We show that the repositioning of genes was closely associated with the swift recruitment of cohesin across the inflammatory enhancer landscape, permitting an immediate transcriptional response upon bacterial exposure. We found that activated enhancers, marked by increased deposition of H3K27Ac, were highly enriched for cistromic elements associated with PU.1, CEBPB, TFE3, JUN, and FOSL2 occupancy. These data reveal how upon microbial challenge the cohesin machinery is recruited to an activated enhancer repertoire to instruct changes in chromatin folding, nuclear architecture, and to activate an inflammatory gene program.
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482.
符毓 Yu
(2023-03-30 12:59):
#paper doi:10.1016/j.joule.2020.07.014, Joule, 2020, Ultrasonic Scanning to Observe Wetting and “Unwetting” in Li-Ion Pouch Cells。锂电池的非破坏性检测方式较少见,X射线检测在电极材料结构、尺寸和热机械效应等有应用,但对于电解质和内部气体不敏感;本文主要探讨用超声方式进行检测的可行性
Abstract:
An ultrasonic imaging technique has been developed to investigate the internal changes of pouch cells nondestructively. The local ultrasonic transmittance of pouch cells has been measured and used for imaging …
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An ultrasonic imaging technique has been developed to investigate the internal changes of pouch cells nondestructively. The local ultrasonic transmittance of pouch cells has been measured and used for imaging with a new ultrasonic scanning machine designed and built in-house. The wetting process of the cells is clearly observed via such ultrasonic imaging techniques. Furthermore, ultrasonic transmission images of fresh cells and aged cells with different electrolytes and cycling conditions exhibit very different ultrasonic transmittance, which can be caused by electrolyte dry-out or “unwetting” due to cell swelling. The ultrasonic imaging technique is a very sensitive method to probe failure mechanisms in Li-ion pouch cells.
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483.
李翛然
(2023-03-28 21:41):
#paper A novel protein RASON encoded by a lncRNA controls oncogenic RAS signaling in KRAS mutant cancers doi: 10.1038/s41422-022-00726-7. Cell Research
. 这篇文章是我最近精读的一篇文章,作者我都认识,做的靶点恰恰是我们正在做的。所以聊了很多。 这是很有可能针对未来一个大癌症种类的核心解决方案。 只不过现在rason 的结构还没有解析出来。 我们看看今年怎么处理一下。
Abstract:
Mutations of the RAS oncogene are found in around 30% of all human cancers yet direct targeting of RAS is still considered clinically impractical except for the KRAS mutant. Here …
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Mutations of the RAS oncogene are found in around 30% of all human cancers yet direct targeting of RAS is still considered clinically impractical except for the KRAS mutant. Here we report that RAS-ON (RASON), a novel protein encoded by the long intergenic non-protein coding RNA 00673 (LINC00673), is a positive regulator of oncogenic RAS signaling. RASON is aberrantly overexpressed in pancreatic ductal adenocarcinoma (PDAC) patients, and it promotes proliferation of human PDAC cell lines in vitro and tumor growth in vivo. CRISPR/Cas9-mediated knockout of Rason in mouse embryonic fibroblasts inhibits KRAS-mediated tumor transformation. Genetic deletion of Rason abolishes oncogenic KRAS-driven pancreatic and lung cancer tumorigenesis in LSL-Kras; Trp53 mice. Mechanistically, RASON directly binds to KRAS and inhibits both intrinsic and GTPase activating protein (GAP)-mediated GTP hydrolysis, thus sustaining KRAS in the GTP-bound hyperactive state. Therapeutically, deprivation of RASON sensitizes KRAS mutant pancreatic cancer cells and patient-derived organoids to EGFR inhibitors. Our findings identify RASON as a critical regulator of oncogenic KRAS signaling and a promising therapeutic target for KRAS mutant cancers.
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484.
姗姗来迟
(2023-03-27 15:44):
#paper arXiv:2201.11903
chain of thought Prompting elicits reasoning in large language models
阅读笔记被记录在本人的博文中:https://blog.csdn.net/weixin_44845357/article/details/129566376
主要是了解思维链(通过逐步回答示例来引出复杂的多步推理的技术)
arXiv,
2022.
Abstract:
We explore how generating a chain of thought -- a series of intermediate reasoning steps -- significantly improves the ability of large language models to perform complex reasoning. In particular, …
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We explore how generating a chain of thought -- a series of intermediate reasoning steps -- significantly improves the ability of large language models to perform complex reasoning. In particular, we show how such reasoning abilities emerge naturally in sufficiently large language models via a simple method called chain of thought prompting, where a few chain of thought demonstrations are provided as exemplars in prompting. Experiments on three large language models show that chain of thought prompting improves performance on a range of arithmetic, commonsense, and symbolic reasoning tasks. The empirical gains can be striking. For instance, prompting a 540B-parameter language model with just eight chain of thought exemplars achieves state of the art accuracy on the GSM8K benchmark of math word problems, surpassing even finetuned GPT-3 with a verifier.
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485.
张浩彬
(2023-03-27 15:40):
#paper 10.1109/ijcnn52387.2021.9533426 Self-Supervised Pre-training for Time Series Classification
少有的时间序列迁移学习文章,利用DTW计算距离建立代理任务构建正负样本来做学习,encoder用的transformer,新意少了点。
Abstract:
Recently, significant progress has been made in time series classification with deep learning. However, using deep learning models to solve time series classification generally suffers from expensive calculations and difficulty …
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Recently, significant progress has been made in time series classification with deep learning. However, using deep learning models to solve time series classification generally suffers from expensive calculations and difficulty of data labeling. In this work, we study self-supervised time series pre-training to overcome these challenges. Compared with the existing works, we focus on the universal and unlabeled time series pretraining. To this end, we propose a novel end-to-end neural network architecture based on self-attention, which is suitable for capturing long-term dependencies and extracting features from different time series. Then, we propose two different self-supervised pretext tasks for time series data type: Denoising and Similarity Discrimination based on DTW (Dynamic Time Warping). Finally, we carry out extensive experiments on 85 time series datasets (also known as UCR2015 [2]). Empirical results show that the time series model augmented with our proposed self-supervised pretext tasks achieves state-of-the-art / highly competitive results.
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486.
惊鸿
(2023-03-27 11:42):
#paper doi:https://ma.x-mol.com/paperRedirect/1639426668090503168 Thymidine nucleotide metabolism controls human telomere length
人类的端粒长度与寿命和严重疾病有关,但端粒长度的遗传决定因素仍未完全确定。在这里,我们进行了全基因组 CRISPR-Cas9 功能性端粒长度筛选,并将胸苷 (dT) 核苷酸代谢确定为人类端粒维持的限制因素。使用 CRISPR-Cas9 的靶向基因破坏揭示了胸苷核苷酸代谢途径中的多个端粒长度控制点:通过删除编码核胸苷激酶 ( TK1 ) 的基因减少 dT 核苷酸回收或通过敲除胸苷酸合酶基因 (TYMS )从头产生端粒长度减少,而脱氧核苷三磷酸水解酶编码基因SAMHD1失活延长的端粒。值得注意的是,单独补充 dT 可通过细胞中的端粒酶驱动端粒的稳健延伸,并且三磷酸胸苷在体外以底物非依赖性方式刺激端粒酶活性。在源自遗传性端粒生物学障碍患者的诱导多能干细胞中,补充 dT 或抑制SAMHD1可促进端粒恢复。我们的结果表明胸苷代谢在控制人端粒酶和端粒长度方面的关键作用,这可能对致命的退行性疾病患者具有治疗作用。
Abstract:
Telomere length in humans is associated with lifespan and severe diseases, yet the genetic determinants of telomere length remain incompletely defined. Here we performed genome-wide CRISPR-Cas9 functional telomere length screening …
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Telomere length in humans is associated with lifespan and severe diseases, yet the genetic determinants of telomere length remain incompletely defined. Here we performed genome-wide CRISPR-Cas9 functional telomere length screening and identified thymidine (dT) nucleotide metabolism as a limiting factor in human telomere maintenance. Targeted genetic disruption using CRISPR-Cas9 revealed multiple telomere length control points across the thymidine nucleotide metabolism pathway: decreasing dT nucleotide salvage via deletion of the gene encoding nuclear thymidine kinase (TK1) or de novo production by knockout of the thymidylate synthase gene (TYMS) decreased telomere length, whereas inactivation of the deoxynucleoside triphosphohydrolase-encoding gene SAMHD1 lengthened telomeres. Remarkably, supplementation with dT alone drove robust telomere elongation by telomerase in cells, and thymidine triphosphate stimulated telomerase activity in a substrate-independent manner in vitro. In induced pluripotent stem cells derived from patients with genetic telomere biology disorders, dT supplementation or inhibition of SAMHD1 promoted telomere restoration. Our results demonstrate a critical role of thymidine metabolism in controlling human telomerase and telomere length, which may be therapeutically actionable in patients with fatal degenerative diseases.
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487.
周周复始
(2023-03-27 11:08):
#paper doi:https://doi.org/10.1038/s41596-023-00806-x. iBEAT V2.0: a multisite-applicable, deep learning-based pipeline for infant cerebral cortical surface reconstruction.2023.为了研究正常和异常的早期大脑发育,用不同的扫描仪和成像方案从多个站点收集了许多婴儿大脑磁共振成像(MRI)。但利用这些多站点成像数据精确地处理和量化婴儿的大脑发育是极具挑战性的,因为髓鞘持续形成和成熟而导致的极低和动态的组织对比,以及由于使用不同的成像协议/扫描仪而导致的不同站点间的数据异质性。现有的计算工具和pipeline通常在婴儿MRI数据上表现不佳。为了解决这些挑战,本文提出了一个鲁棒的、多站点适用的、婴儿定制的计算pipeline,它利用强大的深度学习技术。主要功能包括预处理、脑颅骨剥离、组织分割、拓扑校正、皮层表面表面重建和测量。可以很好地处理T1w和大范围(从出生到6岁)的婴儿大脑结构MRI,并且对不同成像协议/扫描仪差异是有效的,尽管只在BCP上训练。在多站点、多模态和多年龄数据集上与现有方法进行了广泛的比较证明ibeat具有优越的有效性、准确性和鲁棒性。
Abstract:
The human cerebral cortex undergoes dramatic and critical development during early postnatal stages. Benefiting from advances in neuroimaging, many infant brain magnetic resonance imaging (MRI) datasets have been collected from …
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The human cerebral cortex undergoes dramatic and critical development during early postnatal stages. Benefiting from advances in neuroimaging, many infant brain magnetic resonance imaging (MRI) datasets have been collected from multiple imaging sites with different scanners and imaging protocols for the investigation of normal and abnormal early brain development. However, it is extremely challenging to precisely process and quantify infant brain development with these multisite imaging data because infant brain MRI scans exhibit (a) extremely low and dynamic tissue contrast caused by ongoing myelination and maturation and (b) inter-site data heterogeneity resulting from the use of diverse imaging protocols/scanners. Consequently, existing computational tools and pipelines typically perform poorly on infant MRI data. To address these challenges, we propose a robust, multisite-applicable, infant-tailored computational pipeline that leverages powerful deep learning techniques. The main functionality of the proposed pipeline includes preprocessing, brain skull stripping, tissue segmentation, topology correction, cortical surface reconstruction and measurement. Our pipeline can handle both T1w and T2w structural infant brain MR images well in a wide age range (from birth to 6 years of age) and is effective for different imaging protocols/scanners, despite being trained only on the data from the Baby Connectome Project. Extensive comparisons with existing methods on multisite, multimodal and multi-age datasets demonstrate superior effectiveness, accuracy and robustness of our pipeline. We have maintained a website, iBEAT Cloud, for users to process their images with our pipeline ( http://www.ibeat.cloud ), which has successfully processed over 16,000 infant MRI scans from more than 100 institutions with various imaging protocols/scanners.
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488.
哪有情可长
(2023-03-24 21:51):
#paper A Gg protein regulates alkaline sensitivity in crops,science,24 march,2023,doi.org/10.1126/science.ade8416. 为了增加粮食产量,利用盐碱地,培养抗盐碱的作物,实现废田利用是现在作物育种的一大趋势。谢旗团队利用高粱这个抗碱性材料来挖掘基因。首先是通过GWAS鉴定到一个跟水稻中同源的基因(GS3)并命名为AT1(Alkaline tolerance 1),对部分高粱品种测序发现该基因能够分成两个单倍型,发现这个基因能够编码非典型G蛋白γ亚基,通过实验证明该基因能够调节环境胁迫下产生的过氧化氢外流,降低碱性敏感性。并且对该基因在小麦,玉米,水稻等作物中都进行大田试验验证,的确能够抗盐碱。
Abstract:
The use of alkaline salt lands for crop production is hindered by a scarcity of knowledge and breeding efforts for plant alkaline tolerance. Through genome association analysis of sorghum, a …
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The use of alkaline salt lands for crop production is hindered by a scarcity of knowledge and breeding efforts for plant alkaline tolerance. Through genome association analysis of sorghum, a naturally high-alkaline-tolerant crop, we detected a major locus, (), specifically related to alkaline-salinity sensitivity. An allele with a carboxyl-terminal truncation increased sensitivity, whereas knockout of increased tolerance to alkalinity in sorghum, millet, rice, and maize. encodes an atypical G protein γ subunit that affects the phosphorylation of aquaporins to modulate the distribution of hydrogen peroxide (HO) These processes appear to protect plants against oxidative stress by alkali. Designing knockouts of homologs or selecting its natural nonfunctional alleles could improve crop productivity in sodic lands.
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489.
DeDe宝
(2023-03-22 11:38):
#paper doi: https://doi.org/10.1111/psyp.14270
Wrinkles in subsecond time perception are synchronized to the heart
心脏在时间知觉中的作用的证据很少,本研究探究了心脏动力学和亚秒级别时间间隔感知之间的相互作用。被试根据与心脏同步的音调做时间二分法任务,结果显示颞叶对时间间隔感知的延长或缩短与心脏动力学同步。较低的刺激前心理与较长的编码偏差相关。本研究开发了心脏漂移模型(cDDM),为心脏在时间感知觉判断中的作用提供了新的方法论。
Abstract:
The role of the heart in the experience of time has been long theorized but empirical evidence is scarce. Here, we examined the interaction between fine-grained cardiac dynamics and the …
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The role of the heart in the experience of time has been long theorized but empirical evidence is scarce. Here, we examined the interaction between fine-grained cardiac dynamics and the momentary experience of subsecond intervals. Participants performed a temporal bisection task for brief tones (80-188 ms) synchronized with the heart. We developed a cardiac Drift-Diffusion Model (cDDM) that embedded contemporaneous heart rate dynamics into the temporal decision model. Results revealed the existence of temporal wrinkles-dilation or contraction of short intervals-in synchrony with cardiac dynamics. A lower prestimulus heart rate was associated with an initial bias in encoding the millisecond-level stimulus duration as longer, consistent with facilitation of sensory intake. Concurrently, a higher prestimulus heart rate aided more consistent and faster temporal judgments through more efficient evidence accumulation. Additionally, a higher speed of poststimulus cardiac deceleration, a bodily marker of attention, was associated with a greater accumulation of sensory temporal evidence in the cDDM. These findings suggest a unique role of cardiac dynamics in the momentary experience of time. Our cDDM framework opens a new methodological avenue for investigating the role of the heart in time perception and perceptual judgment.
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490.
张德祥
(2023-03-20 10:45):
#paper doi: https://doi.org/10.1101/2022.05.17.492325
Inferring Neural Activity Before Plasticity: A Foundation for Learning Beyond Backpropagation
超越GPT需要从更底层的技术改进,BP是深度学习的核心,生物算法比BP更高效,生物算法是超越BP的一个途径,这篇论文给出了很好的解释及后续论文有一些实验及算法,效率已经可以匹配BP,仍然有更多的优点,
更多可以参考 https://mp.weixin.qq.com/s/lPzGvY6oOnwzVgxDr9ePpA
bioRxiv,
2022.
DOI: 10.1101/2022.05.17.492325
Abstract:
AbstractFor both humans and machines, the essence of learning is to pinpoint which components in its information processing pipeline are responsible for an error in its output — a challenge …
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AbstractFor both humans and machines, the essence of learning is to pinpoint which components in its information processing pipeline are responsible for an error in its output — a challenge that is known ascredit assignment. How the brain solves credit assignment is a key question in neuroscience, and also of significant importance for artificial intelligence. It has long been assumed that credit assignment is best solved by backpropagation, which is also the foundation of modern machine learning. However, it has been questioned whether it is possible for the brain to implement backpropagation and learning in the brain may actually be more efficient and effective than backpropagation. Here, we set out a fundamentally different principle on credit assignment, calledprospective configuration. In prospective configuration, the network first infers the pattern of neural activity that should result from learning, and then the synaptic weights are modified to consolidate the change in neural activity. We demonstrate that this distinct mechanism, in contrast to backpropagation, (1) underlies learning in a well-established family of models of cortical circuits, (2) enables learning that is more efficient and effective in many contexts faced by biological organisms, and (3) reproduces surprising patterns of neural activity and behaviour observed in diverse human and animal learning experiments. Our findings establish a new foundation for learning beyond backpropagation, for both understanding biological learning and building artificial intelligence.
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491.
龙海晨
(2023-03-16 18:02):
#paper Yan Y, Ma Z, Ji X, Liu J, Ji K, Li S, Wu Q. A potential decision-making algorithm based on endoscopic ultrasound for staging early gastric cancer: a retrospective study. BMC Cancer. 2022 Jul 13;22(1):761. doi: 10.1186/s12885-022-09870-0. PMID: 35831843; PMCID: PMC9281103. 文章是研究内镜超声分析所得到的图像与胃癌早期分型间的关系,通过研究影像中肿瘤位置,是否胃溃疡,分化程度,肿瘤大小等指标,建立相关的算法,计算肿瘤分期,确定相应的治疗方案。为早期胃癌诊断治疗提供了一种决策算法。
Abstract:
BACKGROUND: Clinical staging of gastric cancer (GC) before treatment is essential. Endoscopic ultrasound (EUS) is a recommended staging tool, but its efficacy remains controversial. Our previous prospective study evaluated the …
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BACKGROUND: Clinical staging of gastric cancer (GC) before treatment is essential. Endoscopic ultrasound (EUS) is a recommended staging tool, but its efficacy remains controversial. Our previous prospective study evaluated the potential value of EUS for T staging and presented discrepancies. In this study, we aimed to evaluate the efficacy of EUS in T staging by comparing it with pathological staging. We analyze the factors that can potentially affect accuracy to identify suitable subgroups for EUS staging.METHODS: Data from a total of 1763 consecutive patients with GC from January 2015 to December 2017 were analyzed. Results from EUS and pathological T staging were compared. The factors that might affect EUS's accuracy were analyzed.RESULTS: The sensitivity, specificity, positive predictive value, and negative predictive value of EUS in patients with early GC were 62.08%, 96.13%, 90.94%, and 80.21%, respectively. The accuracy rates of uT1, uT2-uT4, and uT3-uT4 were 90.94%, 79.02%, and 78.39%, respectively. In multivariate analysis, underestimation was more likely to be observed in patients with tumors located in the middle or upper third of the stomach. Overestimation was more likely to be observed in patients with tumors located in the lower third or those without ulcer. Other factors affecting accuracy included ulcer, differentiation, larger size and undergoing surgery.CONCLUSION: Our findings highlight the role of EUS in determining the T staging of GC. Overestimation and underestimation in T-staging were significantly associated with the tumor location in early GC, and a decision-making algorithm was proposed for clinical practice in early cancers based on these findings.
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492.
颜林林
(2023-03-12 15:29):
#paper doi:10.1016/j.celrep.2023.112230 Cell Reports, 2023, FAM193A is a positive regulator of p53 activity. 这是一篇典型的关于药物敏感机制探索的细胞学研究,通过分子细胞生物学方法和高通量筛选技术,找到一个新调控基因,并确认其功能。癌症研究中最著名的基因当属TP53(其蛋白则称为p53),这是个抑癌基因,在癌组织中常表现出发生突变或被异常调控。针对其抑制型调控蛋白(如MDM2和MDM4),设计的化合物抑制剂,可激活或促进p53功能,进而达到治疗癌症的目的。Nutlin正是这样的候选药物分子。然而Nutlin在不同细胞系或患者中的表现却差异巨大,其作用机制尚待深入研究。这篇论文通过对药物敏感数据库的分析,以及采用CRISPR screening技术,在多个不同细胞系中进行高通量筛选,识别出FAM193A蛋白,其与Nutlin药物敏感性密切相关,并通过一系列证据,证明FAM193A在p53通路中起到正向调节作用,为后续机制研究和药物开发提供了新的方向。
Abstract:
Inactivation of the p53 tumor suppressor, either by mutations or through hyperactivation of repressors such as MDM2 and MDM4, is a hallmark of cancer. Although many inhibitors of the p53-MDM2/4 …
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Inactivation of the p53 tumor suppressor, either by mutations or through hyperactivation of repressors such as MDM2 and MDM4, is a hallmark of cancer. Although many inhibitors of the p53-MDM2/4 interaction have been developed, such as Nutlin, their therapeutic value is limited by highly heterogeneous cellular responses. We report here a multi-omics investigation of the cellular response to MDM2/4 inhibitors, leading to identification of FAM193A as a widespread regulator of p53 function. CRISPR screening identified FAM193A as necessary for the response to Nutlin. FAM193A expression correlates with Nutlin sensitivity across hundreds of cell lines. Furthermore, genetic codependency data highlight FAM193A as a component of the p53 pathway across diverse tumor types. Mechanistically, FAM193A interacts with MDM4, and FAM193A depletion stabilizes MDM4 and inhibits the p53 transcriptional program. Last, FAM193A expression is associated with better prognosis in multiple malignancies. Altogether, these results identify FAM193A as a positive regulator of p53.
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493.
张德祥
(2023-03-12 09:48):
#paper https://doi.org/10.48550/arXiv.1806.08053 Semantic information, autonomous agency, and nonequilibrium statistical physics
论文尝试通过反事实对语义信息进行定义,通过个体跟环境的物理系,热力学的信息交换来实现,但后续工作不多,和自由能框架有些接近,
arXiv,
2018.
DOI: 10.48550/arXiv.1806.08053
Abstract:
Shannon information theory provides various measures of so-called "syntactic information", which reflect the amount of statistical correlation between systems. In contrast, the concept of "semantic information" refers to those correlations …
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Shannon information theory provides various measures of so-called "syntactic information", which reflect the amount of statistical correlation between systems. In contrast, the concept of "semantic information" refers to those correlations which carry significance or "meaning" for a given system. Semantic information plays an important role in many fields, including biology, cognitive science, and philosophy, and there has been a long-standing interest in formulating a broadly applicable and formal theory of semantic information. In this paper we introduce such a theory. We define semantic information as the syntactic information that a physical system has about its environment which is causally necessary for the system to maintain its own existence. "Causal necessity" is defined in terms of counter-factual interventions which scramble correlations between the system and its environment, while "maintaining existence" is defined in terms of the system's ability to keep itself in a low entropy state. We also use recent results in nonequilibrium statistical physics to analyze semantic information from a thermodynamic point of view. Our framework is grounded in the intrinsic dynamics of a system coupled to an environment, and is applicable to any physical system, living or otherwise. It leads to formal definitions of several concepts that have been intuitively understood to be related to semantic information, including "value of information", "semantic content", and "agency".
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494.
颜林林
(2023-03-02 07:38):
#paper doi:10.1016/j.csbj.2023.02.016 Computational and Structural Biotechnology Journal, 2023, DNAsmart: Multiple attribute ranking tool for DNA data storage systems. 将DNA用作存储介质,已经逐渐成为一个热门的研究方向。由于DNA在读取(测序)和写入(合成)过程中,受到其自身特性和其他环境体系不同因素的影响,存在各类错误。这篇研究提供了一个网站工具DNAsmart,以交互式的方式,可视化地展示核酸片段之间诸如GC含量、汉明距离等不同属性,帮助研究者探索如何有效利用和平衡这些属性的影响,以设计出更合适的DNA存储的编解码方案。
IF:4.400Q2
Computational and structural biotechnology journal,
2023.
DOI: 10.1016/j.csbj.2023.02.016
PMID: 36851917
PMCID:PMC9957737
Abstract:
In an ever-growing need for data storage capacity, the Deoxyribonucleic Acid (DNA) molecule gains traction as a new storage medium with a larger capacity, higher density, and a longer lifespan …
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In an ever-growing need for data storage capacity, the Deoxyribonucleic Acid (DNA) molecule gains traction as a new storage medium with a larger capacity, higher density, and a longer lifespan over conventional storage media. To effectively use DNA for data storage, it is important to understand the different methods of encoding information in DNA and compare their effectiveness. This requires evaluating which decoded DNA sequences carry the most encoded information based on various attributes. However, navigating the field of coding theory requires years of experience and domain expertise. For instance, domain experts rely on various mathematical functions and attributes to score and evaluate their encodings. To enable such analytical tasks, we provide an interactive and visual analytical framework for multi-attribute ranking in DNA storage systems. Our framework follows a three-step view with user-settable parameters. It enables users to find the optimal en-/de-coding approaches by setting different weights and combining multiple attributes. We assess the validity of our work through a task-specific user study on domain experts by relying on three tasks. Results indicate that all participants completed their tasks successfully under two minutes, then rated the framework for design choices, perceived usefulness, and intuitiveness. In addition, two real-world use cases are shared and analyzed as direct applications of the proposed tool. DNAsmart enables the ranking of decoded sequences based on multiple attributes. In sum, this work unveils the evaluation of en-/de-coding approaches accessible and tractable through visualization and interactivity to solve comparison and ranking tasks.
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495.
小擎子
(2023-02-28 23:59):
#paper The cancer chemotherapeutic 5-fluorouracil is a potent Fusobacterium nucleatum inhibitor and its activity is modified by intratumoral microbiota. Cell Rep. 2022 Nov 15;41(7):111625. doi: 10.1016/j.celrep.2022.111625. PMID: 36384132.文章发现结直肠癌里的肿瘤微生物群可以对一线CRC化疗药物5-氟尿嘧啶进行修饰,降低药物的功效。5-氟尿嘧啶既是对结直肠癌上皮细胞有毒性的,也是靶向结肠癌中的核梭杆菌Fn(与癌症进展和复发正相关)的。而肿瘤微生物群修饰5-氟尿嘧啶后,可以减轻对Fn和CRC上皮细胞的毒性。其中结直肠癌肿瘤微生物群里的大肠杆菌在修饰5-氟尿嘧啶的作用得到了证实。文章也用了随机森林对宏基因组数据进行了特征分类,大肠杆菌是5-FU暴露后“修饰者”组的分类,总体而言,具有最高的平均下降精度值,支持大肠杆菌作为模型中分类器的重要性。
Abstract:
Fusobacterium nucleatum (Fn) is a dominant bacterial species in colorectal cancer (CRC) tissue that is associated with cancer progression and poorer patient prognosis. Following a small-molecule inhibitor screen of 1,846 …
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Fusobacterium nucleatum (Fn) is a dominant bacterial species in colorectal cancer (CRC) tissue that is associated with cancer progression and poorer patient prognosis. Following a small-molecule inhibitor screen of 1,846 bioactive compounds against a Fn CRC isolate, we find that 15% of inhibitors are antineoplastic agents including fluoropyrimidines. Validation of these findings reveals that 5-fluorouracil (5-FU), a first-line CRC chemotherapeutic, is a potent inhibitor of Fn CRC isolates. We also identify members of the intratumoral microbiota, including Escherichia coli, that are resistant to 5-FU. Further, CRC E. coli isolates can modify 5-FU and relieve 5-FU toxicity toward otherwise-sensitive Fn and human CRC epithelial cells. Lastly, we demonstrate that ex vivo patient CRC tumor microbiota undergo community disruption after 5-FU exposure and have the potential to deplete 5-FU levels, reducing local drug efficacy. Together, these observations argue for further investigation into the role of the CRC intratumoral microbiota in patient response to chemotherapy.
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496.
cellsarts
(2023-02-28 23:46):
#与海底硫循环有关的新酸杆菌类群Novel taxa of Acidobacteriota implicated in seafloor sulfur cycling
The ISME Journal (2021) 15:3159–3180
https://doi.org/10.1038/s41396-021-00992-0 酸杆菌广泛存在于海洋沉积物中,但其代谢和生态特性尚不清楚。在这里,我们通过宏基因组组装基因组(MAGs)的功能预测,16S rRNA和异源亚硫酸盐还原酶(dsrB)基因和转录物的扩增子测序,以及四硫酸盐修饰的基因表达分析,研究了斯瓦尔巴群岛海洋沉积物中酸杆菌的代谢和分布。在斯瓦尔巴群岛沉积物中,酸杆菌属是仅次于脱硫杆菌属的第二大含有亚硫酸盐还原酶dsrB的门(平均13%),平均占亚硫酸盐还原酶dsrB转录物的4%。对亚硫酸盐还原酶dsrAB数据集的荟萃分析还显示,酸杆菌的亚硫酸盐还原酶dsrAB序列在全球海洋沉积物中非常突出,平均占所有分析序列的15%,并代表了海洋沉积物中大部分以前未分类的亚硫酸盐还原酶dsrAB。我们提出了两个新的酸杆菌属,Candidatus sulomarinibacter(类Thermoanaerobaculia,“细分23”)和Ca. Polarisedimenticola(“细分22”),它们具有独特的遗传特性,可以解释它们在生物地球化学特征不同的沉积物中的分布。Ca. sulomarinibacter编码灵活的呼吸途径,具有潜在的氧、氧化亚氮、金属氧化物、四硫酸盐、硫和亚硫酸盐/硫酸盐呼吸,并可能发生硫歧化。潜在的营养物质和能量包括纤维素、蛋白质、蓝藻素、氢和醋酸酯。A Ca. Polarisedimenticola MAG编码各种酶来降解蛋白质,并减少氧气,硝酸盐,硫/多硫化物和金属氧化物。Svalbard沉积物的16S rRNA基因和转录谱分析显示,Ca. sulomarinibacter成员在硫化物峡湾沉积物中相对丰富且具有转录活性,而Ca. Polarisedimenticola成员在富金属峡湾沉积物中相对丰富。总的来说,我们揭示了未经培养的海洋酸杆菌的各种生理特征,以及在海底生物地球化学循环中的基本作用。
Abstract:
Acidobacteriota are widespread and often abundant in marine sediments, yet their metabolic and ecological properties are poorly understood. Here, we examined metabolisms and distributions of Acidobacteriota in marine sediments of …
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Acidobacteriota are widespread and often abundant in marine sediments, yet their metabolic and ecological properties are poorly understood. Here, we examined metabolisms and distributions of Acidobacteriota in marine sediments of Svalbard by functional predictions from metagenome-assembled genomes (MAGs), amplicon sequencing of 16S rRNA and dissimilatory sulfite reductase (dsrB) genes and transcripts, and gene expression analyses of tetrathionate-amended microcosms. Acidobacteriota were the second most abundant dsrB-harboring (averaging 13%) phylum after Desulfobacterota in Svalbard sediments, and represented 4% of dsrB transcripts on average. Meta-analysis of dsrAB datasets also showed Acidobacteriota dsrAB sequences are prominent in marine sediments worldwide, averaging 15% of all sequences analysed, and represent most of the previously unclassified dsrAB in marine sediments. We propose two new Acidobacteriota genera, Candidatus Sulfomarinibacter (class Thermoanaerobaculia, "subdivision 23") and Ca. Polarisedimenticola ("subdivision 22"), with distinct genetic properties that may explain their distributions in biogeochemically distinct sediments. Ca. Sulfomarinibacter encode flexible respiratory routes, with potential for oxygen, nitrous oxide, metal-oxide, tetrathionate, sulfur and sulfite/sulfate respiration, and possibly sulfur disproportionation. Potential nutrients and energy include cellulose, proteins, cyanophycin, hydrogen, and acetate. A Ca. Polarisedimenticola MAG encodes various enzymes to degrade proteins, and to reduce oxygen, nitrate, sulfur/polysulfide and metal-oxides. 16S rRNA gene and transcript profiling of Svalbard sediments showed Ca. Sulfomarinibacter members were relatively abundant and transcriptionally active in sulfidic fjord sediments, while Ca. Polarisedimenticola members were more relatively abundant in metal-rich fjord sediments. Overall, we reveal various physiological features of uncultured marine Acidobacteriota that indicate fundamental roles in seafloor biogeochemical cycling.
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497.
大勇
(2023-02-28 23:35):
#paper CD8+ T cells and fatty acids orchestrate tumor ferroptosis and immunity via ACSL4. Cancer Cell. 2022 Apr 11;40(4):365-378.e6. doi: 10.1016/j.ccell.2022.02.003. Epub 2022 Feb 24.
这篇文献主要讲述了CD8+T细胞通过分泌内源性的IFNγ,可以作用与肿瘤细胞,引起ACSL4的表达升高,与花生四烯酸协同促进肿瘤的脂质代谢并诱导肿瘤细胞铁死亡,在此过程中,可以促进肿瘤对免疫检查点抑制剂的疗效。
Abstract:
Tumor cell intrinsic ferroptosis-initiating mechanisms are unknown. Here, we discover that T cell-derived interferon (IFN)γ in combination with arachidonic acid (AA) induces immunogenic tumor ferroptosis, serving as a mode of …
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Tumor cell intrinsic ferroptosis-initiating mechanisms are unknown. Here, we discover that T cell-derived interferon (IFN)γ in combination with arachidonic acid (AA) induces immunogenic tumor ferroptosis, serving as a mode of action for CD8 T cell (CTL)-mediated tumor killing. Mechanistically, IFNγ stimulates ACSL4 and alters tumor cell lipid pattern, thereby increasing incorporations of AA into C16 and C18 acyl chain-containing phospholipids. Palmitoleic acid and oleic acid, two common C16 and C18 fatty acids in blood, promote ACSL4-dependent tumor ferroptosis induced by IFNγ plus AA. Moreover, tumor ACSL4 deficiency accelerates tumor progression. Low-dose AA enhances tumor ferroptosis and elevates spontaneous and immune checkpoint blockade (ICB)-induced anti-tumor immunity. Clinically, tumor ACSL4 correlates with T cell signatures and improved survival in ICB-treated cancer patients. Thus, IFNγ signaling paired with selective fatty acids is a natural tumor ferroptosis-promoting mechanism and a mode of action of CTLs. Targeting the ACSL4 pathway is a potential anti-cancer approach.
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498.
张贝
(2023-02-28 23:21):
#paper Nat Med. 2014 Dec;20(12):1479-84.doi: 10.1038/nm.3729. Anchored multiplex PCR for targeted next-generation sequencing
本文首次报道了锚定多重PCR技术(AMP)在基因融合检测方面的应用。与RACE技术的原理类似,AMP将待检测的DNA片段与半功能通用接头连接,经过两轮巢式PCR扩增富集目标片段。与其他常规PCR技术相比,AMP仅通过一端的信息就可以富集目标区域。目前AMP的应用范围已经扩展检测基因的点突变、插入缺失、拷贝数变异、RNA表达等方面。
Abstract:
We describe a rapid target enrichment method for next-generation sequencing, termed anchored multiplex PCR (AMP), that is compatible with low nucleic acid input from formalin-fixed paraffin-embedded (FFPE) specimens. AMP is …
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We describe a rapid target enrichment method for next-generation sequencing, termed anchored multiplex PCR (AMP), that is compatible with low nucleic acid input from formalin-fixed paraffin-embedded (FFPE) specimens. AMP is effective in detecting gene rearrangements (without prior knowledge of the fusion partners), single nucleotide variants, insertions, deletions and copy number changes. Validation of a gene rearrangement panel using 319 FFPE samples showed 100% sensitivity (95% confidence limit: 96.5-100%) and 100% specificity (95% confidence limit: 99.3-100%) compared with reference assays. On the basis of our experience with performing AMP on 986 clinical FFPE samples, we show its potential as both a robust clinical assay and a powerful discovery tool, which we used to identify new therapeutically important gene fusions: ARHGEF2-NTRK1 and CHTOP-NTRK1 in glioblastoma, MSN-ROS1, TRIM4-BRAF, VAMP2-NRG1, TPM3-NTRK1 and RUFY2-RET in lung cancer, FGFR2-CREB5 in cholangiocarcinoma and PPL-NTRK1 in thyroid carcinoma. AMP is a scalable and efficient next-generation sequencing target enrichment method for research and clinical applications.
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499.
小小小小小小萌
(2023-02-28 23:18):
#Paper DOI: https://doi.org/10.1016/j.cell.2022.09.010 Proper acquisition of cell class identify in organoids allows definition of fate specification programs of the human cerebral cortex 这篇文章是发布了人脑类器官的发育过程中的单细胞转录组学,染色质开放组学,空间转录组学的数据。其中,选择了类器官自23天至6个月中的8个时间节点,通过对不同阶段皮层细胞类型特征的捕捉,证实了人脑类器官发育过程中的差异表达基因特征反映的是已知的内源性胚胎发育过程中发育阶段细胞类型特异性的标志基因。经过一系列细胞类型调控机制的研究,比较了人脑类器官和胚胎皮层细胞类型的重叠度,并证明了人脑类器官的细胞类型可以很好的代表内源性胚胎皮层的转录及表观状态特征。
Abstract:
Realizing the full utility of brain organoids to study human development requires understanding whether organoids precisely replicate endogenous cellular and molecular events, particularly since acquisition of cell identity in organoids …
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Realizing the full utility of brain organoids to study human development requires understanding whether organoids precisely replicate endogenous cellular and molecular events, particularly since acquisition of cell identity in organoids can be impaired by abnormal metabolic states. We present a comprehensive single-cell transcriptomic, epigenetic, and spatial atlas of human cortical organoid development, comprising over 610,000 cells, from generation of neural progenitors through production of differentiated neuronal and glial subtypes. We show that processes of cellular diversification correlate closely to endogenous ones, irrespective of metabolic state, empowering the use of this atlas to study human fate specification. We define longitudinal molecular trajectories of cortical cell types during organoid development, identify genes with predicted human-specific roles in lineage establishment, and uncover early transcriptional diversity of human callosal neurons. The findings validate this comprehensive atlas of human corticogenesis in vitro as a resource to prime investigation into the mechanisms of human cortical development.
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500.
na na na
(2023-02-28 23:14):
#paper DOI:10.1038/s41573-021-00387-y. Identification of neoantigens for individualized therapeutic cancer vaccines.目前肿瘤疫苗、CART等通过应用人体自身适应性免疫系统来治疗的方式非常火热,其中有关肿瘤新新抗原识别尤其重要,在20的特斯拉联盟比赛中可以看到,大部分预测出的新抗原,其产生真正免疫原性的数量是很少的,不足30%,继续优化新抗原识别算法非常必要,如果要学习新抗原的识别算法,就必须了解肿瘤新抗原在免疫系统中的作用机制。在这篇综述中,作者比较全面的阐述了T细胞识别新抗原的基本机制,并结合体细胞突变和癌症免疫治疗的新抗原预测的现有方法逻辑之间的关系。并且作者也提出一种新抗原的分类方法,这个分类方法更多考虑了临床关注点,可以了解一下。
Abstract:
Somatic mutations in cancer cells can generate tumour-specific neoepitopes, which are recognized by autologous T cells in the host. As neoepitopes are not subject to central immune tolerance and are …
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Somatic mutations in cancer cells can generate tumour-specific neoepitopes, which are recognized by autologous T cells in the host. As neoepitopes are not subject to central immune tolerance and are not expressed in healthy tissues, they are attractive targets for therapeutic cancer vaccines. Because the vast majority of cancer mutations are unique to the individual patient, harnessing the full potential of this rich source of targets requires individualized treatment approaches. Many computational algorithms and machine-learning tools have been developed to identify mutations in sequence data, to prioritize those that are more likely to be recognized by T cells and to design tailored vaccines for every patient. In this Review, we fill the gaps between the understanding of basic mechanisms of T cell recognition of neoantigens and the computational approaches for discovery of somatic mutations and neoantigen prediction for cancer immunotherapy. We present a new classification of neoantigens, distinguishing between guarding, restrained and ignored neoantigens, based on how they confer proficient antitumour immunity in a given clinical context. Such context-based differentiation will contribute to a framework that connects neoantigen biology to the clinical setting and medical peculiarities of cancer, and will enable future neoantigen-based therapies to provide greater clinical benefit.
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