来自杂志 Nature 的文献。
当前共找到 74 篇文献分享,本页显示第 21 - 40 篇。
21.
林海onrush
(2024-01-31 23:47):
#paper, doi.org/10.1038/s41586-023-06747-5, Solving olympiad geometry without human demonstrations, 此文介绍了一种解决数学奥林匹克竞赛中复杂几何问题的创新方法。论文中提出的AlphaGeometry是一种结合神经语言模型和符号推理引擎的神经符号系统。它能够生成包括定理和证明在内的合成数据,有效克服了此领域训练数据的稀缺性。AlphaGeometry在解决难度较高的奥林匹克级别问题方面表现出色,其性能可与国际数学奥林匹克竞赛(IMO)金牌得主相媲美。它不仅能以人类可读格式合成证明,还发现了一个已知IMO定理的更通用版本。AlphaGeometry在自动定理证明领域取得了重要进展,展示了神经符号系统在解决复杂数学问题方面的潜力,为不依赖人类生成数据的人工智能研究提供了新方向。这一发展对数学和人工智能领域产生深远影响。
Abstract:
Proving mathematical theorems at the olympiad level represents a notable milestone in human-level automated reasoning, owing to their reputed difficulty among the world's best talents in pre-university mathematics. Current machine-learning …
>>>
Proving mathematical theorems at the olympiad level represents a notable milestone in human-level automated reasoning, owing to their reputed difficulty among the world's best talents in pre-university mathematics. Current machine-learning approaches, however, are not applicable to most mathematical domains owing to the high cost of translating human proofs into machine-verifiable format. The problem is even worse for geometry because of its unique translation challenges, resulting in severe scarcity of training data. We propose AlphaGeometry, a theorem prover for Euclidean plane geometry that sidesteps the need for human demonstrations by synthesizing millions of theorems and proofs across different levels of complexity. AlphaGeometry is a neuro-symbolic system that uses a neural language model, trained from scratch on our large-scale synthetic data, to guide a symbolic deduction engine through infinite branching points in challenging problems. On a test set of 30 latest olympiad-level problems, AlphaGeometry solves 25, outperforming the previous best method that only solves ten problems and approaching the performance of an average International Mathematical Olympiad (IMO) gold medallist. Notably, AlphaGeometry produces human-readable proofs, solves all geometry problems in the IMO 2000 and 2015 under human expert evaluation and discovers a generalized version of a translated IMO theorem in 2004.
<<<
翻译
22.
小W
(2024-01-31 23:23):
#paper doi:doi.org/10.1038/s41586-023-06377-x A high-performance speech neuroprosthesis
本文介绍了脑机接口在将脑神经信号转化为文本语言的尝试。文章在患有延髓性肌萎缩侧索硬化症 (ALS)患者的大脑6v (entral premotor cortex)区域和44 (布洛卡区)使用四个微电极阵列检测神经活动信号,训练了一个循环神经网络 (RNN) 解码器,以在每 80 毫秒的时间步长预测当时说出每个音素的概率,将这些概率与语言模型相结合,神经活动信号以每分钟 62 个单词的速度被解码。在 50 个单词的数据集中实现了 9.1% 的单词错误率,125000 个单词的数据集的单词错误率为 23.8%。
同时布洛卡区作用在语言产生的高阶方面,但它似乎几乎不包含音素或单词的信息,即使在瘫痪多年后,患者仍存在音素发音的细节,说明仅从 6v 小区域检测的神经活动信号开发出以正常会话速度恢复瘫痪患者通信设备的可行性。
Abstract:
AbstractSpeech brain–computer interfaces (BCIs) have the potential to restore rapid communication to people with paralysis by decoding neural activity evoked by attempted speech into text1,2 or sound3,4. Early demonstrations, although …
>>>
AbstractSpeech brain–computer interfaces (BCIs) have the potential to restore rapid communication to people with paralysis by decoding neural activity evoked by attempted speech into text1,2 or sound3,4. Early demonstrations, although promising, have not yet achieved accuracies sufficiently high for communication of unconstrained sentences from a large vocabulary1–7. Here we demonstrate a speech-to-text BCI that records spiking activity from intracortical microelectrode arrays. Enabled by these high-resolution recordings, our study participant—who can no longer speak intelligibly owing to amyotrophic lateral sclerosis—achieved a 9.1% word error rate on a 50-word vocabulary (2.7 times fewer errors than the previous state-of-the-art speech BCI2) and a 23.8% word error rate on a 125,000-word vocabulary (the first successful demonstration, to our knowledge, of large-vocabulary decoding). Our participant’s attempted speech was decoded at 62 words per minute, which is 3.4 times as fast as the previous record8 and begins to approach the speed of natural conversation (160 words per minute9). Finally, we highlight two aspects of the neural code for speech that are encouraging for speech BCIs: spatially intermixed tuning to speech articulators that makes accurate decoding possible from only a small region of cortex, and a detailed articulatory representation of phonemes that persists years after paralysis. These results show a feasible path forward for restoring rapid communication to people with paralysis who can no longer speak.
<<<
翻译
23.
符毓 Yu
(2023-12-31 16:44):
#paper doi.org/10.1038/s41586-023-06306-y Nature, 2023, Solid-body trajectoids shaped to roll along
desired pathways 本文介绍了一种名为trajectoids的固体轨迹体,可以沿着所需路径滚动,并通过算法设计出这些轨迹体,并通过三维打印验证了这些设计的可行性。文章探讨了轨迹体的运动规律、路径设计和形态学,并提供了多个物理系统中的应用案例,如量子力学、经典光学和机器人学等。研究结果对于理解物体运动的动力学和设计新型光学器件具有重要意义
Abstract:
No abstract available.
24.
大勇
(2023-11-30 21:45):
#paper https://doi.org/10.1038/s41586-023-05710-8 Nassour, J., Aguiar, L.G., Correia, A. et al. Telomere-to-mitochondria signalling by ZBP1 mediates replicative crisis. Nature 614, 767–773 (2023). 这篇文献主要是发现了永生化细胞不死的机制,通过讲端粒、衰老和和免疫结合起来,从侧面为肿瘤细胞的异常增殖提供了新的思路。全文仅仅用了简单的WB和免疫荧光等技术,完成了比较有创新性的课题并发表在了nature上。整篇文献发现永生化细胞中ZBP1表达升高和I型干扰素信号通路激活,通过分析发现ZBP1可以与端粒不稳定相关RNA结合并定位于线粒体上,从而激活MAVS和下游I型干扰素信号通路维持细胞的生长,而端粒的不稳定又会激活cGAS信号通路,引起I型干扰素信号通路激活导致ZBP1升高,从而形成了一个环路。
Abstract:
Cancers arise through the accumulation of genetic and epigenetic alterations that enable cells to evade telomere-based proliferative barriers and achieve immortality. One such barrier is replicative crisis-an autophagy-dependent program that …
>>>
Cancers arise through the accumulation of genetic and epigenetic alterations that enable cells to evade telomere-based proliferative barriers and achieve immortality. One such barrier is replicative crisis-an autophagy-dependent program that eliminates checkpoint-deficient cells with unstable telomeres and other cancer-relevant chromosomal aberrations. However, little is known about the molecular events that regulate the onset of this important tumour-suppressive barrier. Here we identified the innate immune sensor Z-DNA binding protein 1 (ZBP1) as a regulator of the crisis program. A crisis-associated isoform of ZBP1 is induced by the cGAS-STING DNA-sensing pathway, but reaches full activation only when associated with telomeric-repeat-containing RNA (TERRA) transcripts that are synthesized from dysfunctional telomeres. TERRA-bound ZBP1 oligomerizes into filaments on the outer mitochondrial membrane of a subset of mitochondria, where it activates the innate immune adapter protein mitochondrial antiviral-signalling protein (MAVS). We propose that these oligomerization properties of ZBP1 serve as a signal amplification mechanism, where few TERRA-ZBP1 interactions are sufficient to launch a detrimental MAVS-dependent interferon response. Our study reveals a mechanism for telomere-mediated tumour suppression, whereby dysfunctional telomeres activate innate immune responses through mitochondrial TERRA-ZBP1 complexes to eliminate cells destined for neoplastic transformation.
<<<
翻译
25.
小年
(2023-11-30 16:01):
#paper Augusto, D.G., Murdolo, L.D., Chatzileontiadou, D.S.M. et al. A common allele of HLA is associated with asymptomatic SARS-CoV-2 infection. Nature 620, 128–136 (2023). https://doi.org/10.1038/s41586-023-06331-x.
大多数感染COVID-19的人会出现诸如发热、干咳、咽痛、嗅觉减退等典型临床症状。然而也有一部分人群即便感染了新冠病毒,也不会出现任何症状,这些人被称为无症状感染者。为探索这一现象的背后遗传机制中,本项研究使用了29,947名样本的高分辨HLA分型数据,发现人类白细胞抗原(HLA)基因座的变异可能是影响SARS-CoV-2感染者是否出现症状的关键因素。进一步的研究表明,这种遗传关联可能源于预先存在的T细胞免疫。来自携带HLA-B*15:01个体的大流行前样本中的T细胞对SARS-CoV-2 S蛋白衍生的主要免疫原性肽段NQKLIANQF表现出反应性。这些T细胞大多数呈现记忆表型,具有高度多功能性,并与季节性冠状病毒衍生的肽段交叉反应。除此之外,HLA-B15:01–肽段复合物的晶体结构,展示了NQKLIANQF和NQKLIANAF肽段被HLA-B15:01稳定并呈现的相似能力。最后,研究揭示了肽段结构相似性是HLA-B*15:01介导的预先存在免疫的分子基础,这种免疫是由高亲和力的公共T细胞受体的T细胞交叉反应性所决定的。综上所述,这项研究深入阐释了SARS-CoV-2无症状感染背后的遗传和免疫学机制,尤其是HLA-B*15:01基因座的作用。
Abstract:
Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic. Although most global efforts have focused on severe illness in COVID-19, examining asymptomatic infection provides a …
>>>
Studies have demonstrated that at least 20% of individuals infected with SARS-CoV-2 remain asymptomatic. Although most global efforts have focused on severe illness in COVID-19, examining asymptomatic infection provides a unique opportunity to consider early immunological features that promote rapid viral clearance. Here, postulating that variation in the human leukocyte antigen (HLA) loci may underly processes mediating asymptomatic infection, we enrolled 29,947 individuals, for whom high-resolution HLA genotyping data were available, in a smartphone-based study designed to track COVID-19 symptoms and outcomes. Our discovery cohort (n = 1,428) comprised unvaccinated individuals who reported a positive test result for SARS-CoV-2. We tested for association of five HLA loci with disease course and identified a strong association between HLA-B*15:01 and asymptomatic infection, observed in two independent cohorts. Suggesting that this genetic association is due to pre-existing T cell immunity, we show that T cells from pre-pandemic samples from individuals carrying HLA-B*15:01 were reactive to the immunodominant SARS-CoV-2 S-derived peptide NQKLIANQF. The majority of the reactive T cells displayed a memory phenotype, were highly polyfunctional and were cross-reactive to a peptide derived from seasonal coronaviruses. The crystal structure of HLA-B*15:01-peptide complexes demonstrates that the peptides NQKLIANQF and NQKLIANAF (from OC43-CoV and HKU1-CoV) share a similar ability to be stabilized and presented by HLA-B*15:01. Finally, we show that the structural similarity of the peptides underpins T cell cross-reactivity of high-affinity public T cell receptors, providing the molecular basis for HLA-B*15:01-mediated pre-existing immunity.
<<<
翻译
26.
大勇
(2023-10-31 22:35):
#paper https://doi.org/10.1038/s41586-020-2682-1 Cancer SLC43A2 alters T cell methionine metabolism and histone methylation
本文献以甲硫氨酸代谢为主要内容,肿瘤细胞通过SLC48A2转运体与CD8+T细胞竞争甲硫氨酸,导致T细胞甲硫氨酸摄取减少,从而影响甲硫氨酸代谢,抑制组蛋白H3K79me2,进而抑制了STAT5的通路激活,最终导致CD8+T细胞杀伤功能减退和凋亡增多。
Abstract:
Abnormal epigenetic patterns correlate with effector T cell malfunction in tumours, but the cause of this link is unknown. Here we show that tumour cells disrupt methionine metabolism in CD8 …
>>>
Abnormal epigenetic patterns correlate with effector T cell malfunction in tumours, but the cause of this link is unknown. Here we show that tumour cells disrupt methionine metabolism in CD8 T cells, thereby lowering intracellular levels of methionine and the methyl donor S-adenosylmethionine (SAM) and resulting in loss of dimethylation at lysine 79 of histone H3 (H3K79me2). Loss of H3K79me2 led to low expression of STAT5 and impaired T cell immunity. Mechanistically, tumour cells avidly consumed methionine and outcompeted T cells for methionine by expressing high levels of the methionine transporter SLC43A2. Genetic and biochemical inhibition of tumour SLC43A2 restored H3K79me2 in T cells, thereby boosting spontaneous and checkpoint-induced tumour immunity. Moreover, methionine supplementation improved the expression of H3K79me2 and STAT5 in T cells, and this was accompanied by increased T cell immunity in tumour-bearing mice and patients with colon cancer. Clinically, tumour SLC43A2 correlated negatively with T cell histone methylation and functional gene signatures. Our results identify a mechanistic connection between methionine metabolism, histone patterns, and T cell immunity in the tumour microenvironment. Thus, cancer methionine consumption is an immune evasion mechanism, and targeting cancer methionine signalling may provide an immunotherapeutic approach.
<<<
翻译
27.
小W
(2023-10-01 00:00):
#paper doi:https://doi.org/10.1038/s41586-023-06511-9 CD300ld on neutrophils is required for
tumour-driven immune suppression 以髓系细胞含量高为特征的免疫抑制肿瘤微环境(TME)是免疫治疗的主要障碍,在肿瘤环境中,大多数髓系细胞被鉴定为具有免疫抑制的病理异常活化的中性粒细胞(PMN-MDSCs)。
跨膜蛋白 CD300ld的表达仅限于骨髓细胞,且在中性粒细胞中高表达。本文 开发了 CD300ld 敲除小鼠模型(Cd300ld-KO),验证了CD300ld通过PMN-MDSCs起作用。Cd300ld-KO小鼠肿瘤中的大多数免疫抑制细胞群减少,大多数抗肿瘤作用细胞群增加,免疫微环境从促肿瘤变为抗肿瘤。CD300ld通过下游路径 S100A8/A9 在PMN-MDSC向肿瘤的迁移和募集以及中性粒细胞向病理抑制过度中起关键作用。
Abstract:
The immune-suppressive tumour microenvironment represents a major obstacle to effective immunotherapy. Pathologically activated neutrophils, also known as polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), are a critical component of the tumour microenvironment …
>>>
The immune-suppressive tumour microenvironment represents a major obstacle to effective immunotherapy. Pathologically activated neutrophils, also known as polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), are a critical component of the tumour microenvironment and have crucial roles in tumour progression and therapy resistance. Identification of the key molecules on PMN-MDSCs is required to selectively target these cells for tumour treatment. Here, we performed an in vivo CRISPR-Cas9 screen in a tumour mouse model and identified CD300ld as a top candidate of tumour-favouring receptors. CD300ld is specifically expressed in normal neutrophils and is upregulated in PMN-MDSCs upon tumour-bearing. CD300ld knockout inhibits the development of multiple tumour types in a PMN-MDSC-dependent manner. CD300ld is required for the recruitment of PMN-MDSCs into tumours and their function to suppress T cell activation. CD300ld acts via the STAT3-S100A8/A9 axis, and knockout of Cd300ld reverses the tumour immune-suppressive microenvironment. CD300ld is upregulated in human cancers and shows an unfavourable correlation with patient survival. Blocking CD300ld activity inhibits tumour development and has synergistic effects with anti-PD1. Our study identifies CD300ld as a critical immune suppressor present on PMN-MDSCs, being required for tumour immune resistance and providing a potential target for cancer immunotherapy.
<<<
翻译
28.
惊鸿
(2023-09-30 19:52):
#paper Fear of the dark
The invisible enemy. 27 September 2023
https://doi.org/10.1038/d41586-023-03002-9
这篇文章描述了一个军官与一位教授的对话,讨论了关于暗物质中的生物存在和潜在威胁的问题。故事中,教授向军官解释了暗物质的存在和性质,并透露他们已经发现了一些暗物质的聚集体,里面有活动的“事物”。这些事物不仅仅是无生命的物质,它们还拥有技术,并且暗物质的力量比我们所知的力量更为强大。教授担心这些暗物质生物可能会利用他们的技术建造引力武器,对人类构成威胁。因此,他建议采取行动,并使用一个小型黑洞来消灭他们。最后,军官同意了这个建议,并表示将动用军队来执行任务。
Abstract:
No abstract available.
29.
符毓 Yu
(2023-09-30 10:07):
#paper doi:10.1038/171737a0 International Conference on Industrial Engineering and Systems Management (IESM), 2019, AMHS Vehicle Management Policies in
Semiconductor Manufacturing: A Short Review. AMHS(Automated Material Handling Systems)在半导体晶圆厂里属于较为重要的设备系统,主要解决不同加工工序间物料的等待和运输效率问题。国内有少数企业正在努力做此环节的国产替代故而关注到这个方向。本文较为基础,介绍了AMHS的背景、特征和构成,以及主流调度方法的各自优缺点
Abstract:
No abstract available.
30.
小年
(2023-09-30 08:20):
#paper draft human pangenome reference, Nature, 10 May 2023. doi.org/10.1038/s41586-023-05896-x.
这篇文章中人类泛基因组参考联盟(Human Pangenome Reference Consortium)首次呈现了人类泛基因组参考图谱的初步版本。该泛基因组参考图谱由来自遗传多样性人群的47个单倍体定相的二倍体组装基因组序列构成。这些组装序列覆盖了每个基因组中超过99%的序列,并且在结构和碱基水平上的准确性也超过99%。基于这些组装序列的比对,本篇文章作者生成了一个初步版本的泛基因组参考图谱,其中包含已知变异和单倍型,并揭示了在结构复杂位点上的新等位基因。此外,相对于现有的GRCh38参考基因组,泛基因组参考图谱添加了11,900万个常染色体多态位点和1,115个基因重复,其中约有9,000万个额外的碱基对来自结构变异。基于初步版本泛基因组参考图谱分析短读长测序数据,相对于基于GRCh38的工作流程,小突变的检测误差降低了34%,每个单倍型序列检测到的结构变异数量增加了104%,并且实现了对大多数样本的结构变异等位基因的分型。
思考:目前通用的人类参考基因组(GRCh38)是基于多个捐献者的DNA组装成而成线性参考基因组,捐献者主要以非裔和欧裔为主,亚裔成分较少。由于世界各地区人群中存在大量的遗传多态性,GRCh38并不能代表各个群体内所有的遗传多态性。本篇文章生成了来自世界各地区人群的47个单倍型定相的组装基因组,从而构建了人类泛基因组的初步版本。通过对短读长测序数据进行分析,发现相较于GRCh38的检测流程,对各类型的遗传突变都有了更好的检测效果。不过本篇文章构建的泛基因组主要是基于美洲和非洲人群,亚洲人群的比例只有13%,可能并不能很好的代表亚洲人群的遗传多样性。
Abstract:
Here the Human Pangenome Reference Consortium presents a first draft of the human pangenome reference. The pangenome contains 47 phased, diploid assemblies from a cohort of genetically diverse individuals. These …
>>>
Here the Human Pangenome Reference Consortium presents a first draft of the human pangenome reference. The pangenome contains 47 phased, diploid assemblies from a cohort of genetically diverse individuals. These assemblies cover more than 99% of the expected sequence in each genome and are more than 99% accurate at the structural and base pair levels. Based on alignments of the assemblies, we generate a draft pangenome that captures known variants and haplotypes and reveals new alleles at structurally complex loci. We also add 119 million base pairs of euchromatic polymorphic sequences and 1,115 gene duplications relative to the existing reference GRCh38. Roughly 90 million of the additional base pairs are derived from structural variation. Using our draft pangenome to analyse short-read data reduced small variant discovery errors by 34% and increased the number of structural variants detected per haplotype by 104% compared with GRCh38-based workflows, which enabled the typing of the vast majority of structural variant alleles per sample.
<<<
翻译
31.
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 …
>>>
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.
<<<
翻译
32.
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 …
>>>
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.
<<<
翻译
33.
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 …
>>>
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.
<<<
翻译
34.
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, …
>>>
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.
<<<
翻译
35.
大勇
(2023-07-31 23:24):
#paper Bergholz, J.S., Wang, Q., Wang, Q. et al. PI3Kβ controls immune evasion in PTEN-deficient breast tumours. Nature 617, 139-146 (2023). https://doi.org/10.1038/s41586-023-05940-w 这篇文献在机制方面并没有深入研究,但却是有很好的临床转化前景,在PTEN缺失的肿瘤中,PI3K发挥着重要作用,作者发现其中PI3Kβ是引起该类肿瘤免疫抑制的关键分子,靶向PI3Kβ-BMX-STAT3信号通路可以有效逆转免疫抑制的状态,而且可以促进免疫治疗的疗效
Abstract:
Loss of the PTEN tumour suppressor is one of the most common oncogenic drivers across all cancer types. PTEN is the major negative regulator of PI3K signalling. The PI3Kβ isoform …
>>>
Loss of the PTEN tumour suppressor is one of the most common oncogenic drivers across all cancer types. PTEN is the major negative regulator of PI3K signalling. The PI3Kβ isoform has been shown to play an important role in PTEN-deficient tumours, but the mechanisms underlying the importance of PI3Kβ activity remain elusive. Here, using a syngeneic genetically engineered mouse model of invasive breast cancer driven by ablation of both Pten and Trp53 (which encodes p53), we show that genetic inactivation of PI3Kβ led to a robust anti-tumour immune response that abrogated tumour growth in syngeneic immunocompetent mice, but not in immunodeficient mice. Mechanistically, PI3Kβ inactivation in the PTEN-null setting led to reduced STAT3 signalling and increased the expression of immune stimulatory molecules, thereby promoting anti-tumour immune responses. Pharmacological PI3Kβ inhibition also elicited anti-tumour immunity and synergized with immunotherapy to inhibit tumour growth. Mice with complete responses to the combined treatment displayed immune memory and rejected tumours upon re-challenge. Our findings demonstrate a molecular mechanism linking PTEN loss and STAT3 activation in cancer and suggest that PI3Kβ controls immune escape in PTEN-null tumours, providing a rationale for combining PI3Kβ inhibitors with immunotherapy for the treatment of PTEN-deficient breast cancer.
<<<
翻译
36.
张贝
(2023-07-31 23:10):
#paper Structural basis for DNMT3A-mediated de novo DNA methylation. Nature. 2018 Feb 15;554(7692):387-391.doi: 10.1038/nature25477. DNA甲基化会改变基因表达,调节基因组稳定性和细胞分化。在人体中,甲基化过程的失调与各种疾病,特别是癌症有关。DNMT3A和DNMT3B催化哺乳动物的从头甲基化过程,然而,DNMT3底物识别和酶特异性的机制仍不明确。本文报道了分辨率为2.6埃的DNMT3A-DNMT3L-DNA复合物晶体结构,其中两个DNMT3A单体同时攻击两个CpG二核苷酸,两个CpG位点间距离14个碱基对。DNMT3A- DNA相互作用包括一个靶向识别结构域、一个催化loop和DNMT3A同源二聚体interface。靶向识别结构域的Arg836与CpG进行关键作用,确保DNMT3A酶对CpG位点的偏好性。
Abstract:
DNA methylation by de novo DNA methyltransferases 3A (DNMT3A) and 3B (DNMT3B) at cytosines is essential for genome regulation and development. Dysregulation of this process is implicated in various diseases, …
>>>
DNA methylation by de novo DNA methyltransferases 3A (DNMT3A) and 3B (DNMT3B) at cytosines is essential for genome regulation and development. Dysregulation of this process is implicated in various diseases, notably cancer. However, the mechanisms underlying DNMT3 substrate recognition and enzymatic specificity remain elusive. Here we report a 2.65-ångström crystal structure of the DNMT3A-DNMT3L-DNA complex in which two DNMT3A monomers simultaneously attack two cytosine-phosphate-guanine (CpG) dinucleotides, with the target sites separated by 14 base pairs within the same DNA duplex. The DNMT3A-DNA interaction involves a target recognition domain, a catalytic loop, and DNMT3A homodimeric interface. Arg836 of the target recognition domain makes crucial contacts with CpG, ensuring DNMT3A enzymatic preference towards CpG sites in cells. Haematological cancer-associated somatic mutations of the substrate-binding residues decrease DNMT3A activity, induce CpG hypomethylation, and promote transformation of haematopoietic cells. Together, our study reveals the mechanistic basis for DNMT3A-mediated DNA methylation and establishes its aetiological link to human disease.
<<<
翻译
37.
白鸟
(2023-07-31 22:58):
#paper https://doi.org/10.1038/s41586-023-06252-9 A spatially resolved single-cell genomic atlas of the adult human breast 该项目是陈-扎克伯格倡议(Chan Zuckerberg Initiative)支持的全球人类细胞图谱(Human Cell Atlas)联盟的一部分,该联盟利用最新技术为人体的每个器官系统构建细胞参考图谱。
研究目的:
人类乳腺的解剖学和组织病理学已经研究了几十年,为发育、哺乳和疾病提供了深入见解。最近,用分子和基因组技术对正常乳腺组织进行了表征,这些方法主要集中在上皮细胞上。迄今为止,仍然缺乏对所有细胞类型及其生物亚型(细胞状态)的无偏的全面解析。
研究意义:
1.HBCA图谱数据为研究乳腺生物学和乳腺癌等疾病状态提供了前所未有的成人正常乳腺组织的参考;
2.HBCA项目的所有单细胞和空间数据都可以通过官方的门户网站公开访问;
3. 人类细胞图谱(HCA,Human Cell Atlas)的一部分;
Abstract:
The adult human breast is comprised of an intricate network of epithelial ducts and lobules that are embedded in connective and adipose tissue. Although most previous studies have focused on …
>>>
The adult human breast is comprised of an intricate network of epithelial ducts and lobules that are embedded in connective and adipose tissue. Although most previous studies have focused on the breast epithelial system, many of the non-epithelial cell types remain understudied. Here we constructed the comprehensive Human Breast Cell Atlas (HBCA) at single-cell and spatial resolution. Our single-cell transcriptomics study profiled 714,331 cells from 126 women, and 117,346 nuclei from 20 women, identifying 12 major cell types and 58 biological cell states. These data reveal abundant perivascular, endothelial and immune cell populations, and highly diverse luminal epithelial cell states. Spatial mapping using four different technologies revealed an unexpectedly rich ecosystem of tissue-resident immune cells, as well as distinct molecular differences between ductal and lobular regions. Collectively, these data provide a reference of the adult normal breast tissue for studying mammary biology and diseases such as breast cancer.
<<<
翻译
38.
惊鸿
(2023-07-29 17:48):
#paper CAR T therapy beyond cancer: the evolution of a living drug DOI : 10.1038/s41586-023-06243-w 2023-07-26 通过改造患者自身的 T 细胞来选择性地靶向并消除肿瘤细胞,已经治愈了患有无法治疗的血液癌症的患者。这些结果推动了嵌合抗原受体 (CAR) T 疗法在整个肿瘤学领域的应用。然而,临床和临床前研究的证据强调了 CAR T 疗法在肿瘤学之外治疗自身免疫、慢性感染、心脏纤维化、衰老相关疾病和其他疾病方面的潜力。同时,新技术和平台的部署为 CAR T 疗法应用于非癌症病理提供了进一步的机会。在这里,我们回顾了 CAR T 疗法背后的基本原理、当前肿瘤学面临的挑战、非癌症疾病初步报告的概要,以及对相关新兴技术的讨论。我们研究了这种疗法在各种情况下的潜在应用。最后,我们强调了对特异性和安全性的担忧,并概述了 CAR T 疗法超越癌症的前进道路。
Abstract:
Engineering a patient's own T cells to selectively target and eliminate tumour cells has cured patients with untreatable haematologic cancers. These results have energized the field to apply chimaeric antigen …
>>>
Engineering a patient's own T cells to selectively target and eliminate tumour cells has cured patients with untreatable haematologic cancers. These results have energized the field to apply chimaeric antigen receptor (CAR) T therapy throughout oncology. However, evidence from clinical and preclinical studies underscores the potential of CAR T therapy beyond oncology in treating autoimmunity, chronic infections, cardiac fibrosis, senescence-associated disease and other conditions. Concurrently, the deployment of new technologies and platforms provides further opportunity for the application of CAR T therapy to noncancerous pathologies. Here we review the rationale behind CAR T therapy, current challenges faced in oncology, a synopsis of preliminary reports in noncancerous diseases, and a discussion of relevant emerging technologies. We examine potential applications for this therapy in a wide range of contexts. Last, we highlight concerns regarding specificity and safety and outline the path forward for CAR T therapy beyond cancer.
<<<
翻译
39.
张贝
(2023-06-30 23:14):
#paper DNA methylation-based classification of central nervous system tumours Nature. 2018 Mar 22;555(7697):469-474.doi:10.1038/nature26000
肿瘤的正确诊断对于后期治疗至关重要,然而在已知的近100多种中枢神经系统肿瘤 (central nervous system tumor,CNS tumor)中,相关标准化的诊断面临很大的挑战。为了高效、迅速的对CNS肿瘤进行分类,作者开发了一个机器学习模型,它可以对甲基化数据进行分类。开发出来的程序经过训练后,可以使用甲基化特征鉴定91种CNS肿瘤。训练集采用的参照数据来自约2800名癌症患者。作者在1104例已经经过人工检查的中枢神经系统肿瘤上进行了测试,发现有12%例存在误诊。该模型不仅可以提高诊断准确率,而且还可以鉴定出新型罕见肿瘤。为了让这种新方法得到广泛应用,作者生成了一款免费在线工具 (Molecular Neuropathology 2.0; http://www.kitz-heidelberg.de/molecular-diagnostics),可以在几分钟内分析上传的数据。自2016年12月上线以来,该工具已被使用逾4500次,用户可以选择分享他们的数据,以便进一步优化算法。作者总结表示,将甲基化特征与脑肿瘤自动分类器整合起来还可以为创造类似的肿瘤分类算法用于诊断其它癌症类型提供一个蓝图。
Abstract:
Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has …
>>>
Accurate pathological diagnosis is crucial for optimal management of patients with cancer. For the approximately 100 known tumour types of the central nervous system, standardization of the diagnostic process has been shown to be particularly challenging-with substantial inter-observer variability in the histopathological diagnosis of many tumour types. Here we present a comprehensive approach for the DNA methylation-based classification of central nervous system tumours across all entities and age groups, and demonstrate its application in a routine diagnostic setting. We show that the availability of this method may have a substantial impact on diagnostic precision compared to standard methods, resulting in a change of diagnosis in up to 12% of prospective cases. For broader accessibility, we have designed a free online classifier tool, the use of which does not require any additional onsite data processing. Our results provide a blueprint for the generation of machine-learning-based tumour classifiers across other cancer entities, with the potential to fundamentally transform tumour pathology.
<<<
翻译
40.
muton
(2023-06-30 21:57):
# Paper: Doeller, C. F., Barry, C., & Burgess, N. (2010). Evidence for grid cells in a human memory network. Nature, 463(7281), 657–661. https://doi.org/10.1038/nature08704
自由运动大鼠内嗅皮层中的网格细胞提供了自我定位的显著周期性表征,这表明了非常特殊的计算机制。然而,网格细胞在人类中的存在及其在整个大脑中的分布是未知的。本研究表明,大鼠内嗅皮层定向调节的网格细胞的优先放电方向与网格对齐,并且快跑与慢跑相比,网格细胞放电的空间组织更为明显。由于网格细胞的一致性特征,作者预测了在更宏观的信号,也就是人类的功能性磁共振成像(fMRI)记录中也会发现网格细胞的相关证据。因此,作者模拟老鼠的觅食任务,让参与者探索虚拟现实环境,结果显示fMRI激活和适应在跑步方向上显示出由速度调节的六倍旋转对称的特性。这种信号在鼻内/丘下、顶叶后部和内侧、颞外侧和前额叶内侧的网络中都有发现。并且该效应在右内嗅皮层表现最为明显,方向信号在内嗅皮层间的相干性与空间记忆表现相关。本研究提示了将单细胞电生理学与功能磁共振成像在系统神经科学中结合的潜在可能。本研究结果为人类的网格细胞样表征提供了证据,并暗示在支持空间认知和自传体记忆的区域网络中存在一种特定类型神经表征。
Abstract:
Grid cells in the entorhinal cortex of freely moving rats provide a strikingly periodic representation of self-location which is indicative of very specific computational mechanisms. However, the existence of grid …
>>>
Grid cells in the entorhinal cortex of freely moving rats provide a strikingly periodic representation of self-location which is indicative of very specific computational mechanisms. However, the existence of grid cells in humans and their distribution throughout the brain are unknown. Here we show that the preferred firing directions of directionally modulated grid cells in rat entorhinal cortex are aligned with the grids, and that the spatial organization of grid-cell firing is more strongly apparent at faster than slower running speeds. Because the grids are also aligned with each other, we predicted a macroscopic signal visible to functional magnetic resonance imaging (fMRI) in humans. We then looked for this signal as participants explored a virtual reality environment, mimicking the rats' foraging task: fMRI activation and adaptation showing a speed-modulated six-fold rotational symmetry in running direction. The signal was found in a network of entorhinal/subicular, posterior and medial parietal, lateral temporal and medial prefrontal areas. The effect was strongest in right entorhinal cortex, and the coherence of the directional signal across entorhinal cortex correlated with spatial memory performance. Our study illustrates the potential power of combining single-unit electrophysiology with fMRI in systems neuroscience. Our results provide evidence for grid-cell-like representations in humans, and implicate a specific type of neural representation in a network of regions which supports spatial cognition and also autobiographical memory.
<<<
翻译