当前共找到 1086 篇文献分享,本页显示第 521 - 540 篇。
521.
颜林林
(2023-02-27 21:12):
#paper doi:10.3390/ijms24043588 International Journal of Molecular Sciences, 2023, A DNA Finite-State Machine Based on the Programmable Allosteric Strategy of DNAzyme. 本研究利用核酶(一种具有特定序列和构象的DNA分子,本身具有切割特定核酸片段的催化能力)的特性,构建了一个具有不同状态的纳米机器体系,通过加入不同的核酸分子(作为输入),使体系中发生链置换反应,从而使人工设计的核酶分子,可逆地改变为不同状态,并通过切割报告核酸分子输出荧光信号进行确认,从实验上验证了用DNA分子实现有限状态机的可行性。除了实时监测反应体系的荧光信号外,本研究也通过电泳对体系中存在的各个核酸分子进行了确认。本研究分别实现了两状态和五状态的有限状态机,从概念上验证了,可以通过增加不同序列的核酸分子,实现状态机的状态数量扩展,可据此进一步研发更复杂的DNA纳米分子机器。
IF:4.900Q2
International journal of molecular sciences,
2023-Feb-10.
DOI: 10.3390/ijms24043588
PMID: 36834996
Abstract:
Living organisms can produce corresponding functions by responding to external and internal stimuli, and this irritability plays a pivotal role in nature. Inspired by such natural temporal responses, the development …
>>>
Living organisms can produce corresponding functions by responding to external and internal stimuli, and this irritability plays a pivotal role in nature. Inspired by such natural temporal responses, the development and design of nanodevices with the ability to process time-related information could facilitate the development of molecular information processing systems. Here, we proposed a DNA finite-state machine that can dynamically respond to sequential stimuli signals. To build this state machine, a programmable allosteric strategy of DNAzyme was developed. This strategy performs the programmable control of DNAzyme conformation using a reconfigurable DNA hairpin. Based on this strategy, we first implemented a finite-state machine with two states. Through the modular design of the strategy, we further realized the finite-state machine with five states. The DNA finite-state machine endows molecular information systems with the ability of reversible logic control and order detection, which can be extended to more complex DNA computing and nanomachines to promote the development of dynamic nanotechnology.
<<<
翻译
522.
钟鸣
(2023-02-27 19:18):
#paper doi:10.3389/fvets.2020.00388 Assisting Decision-Making on Age of Neutering for 35 Breeds of Dogs: Associated Joint Disorders, Cancers, and Urinary Incontinence
这是一篇有关犬的最佳绝育年龄的循证研究。此前已经发现,绝育会增加犬罹患关节疾病和癌症的风险,无论性别是雌性或雄性。绝育时的年龄也同样会影响到这些疾病的发生,但由于不同品种间犬的体格和遗传背景相差很大,因此作者团队对包括柯基、贵宾、比格、金毛、德牧在内的共35个品种的犬的绝育年龄与健康状况做了调查,样本主要来源于作者所在的动物医院。作者详细报告了每个品种犬的关节疾病与肿瘤疾病患病风险增加与绝育年龄或性别的相关性,总的来说不同品种有相应的最佳绝育年龄,甚至同一品种的不同性别个体也有不同的最佳绝育年龄。但这篇研究中没有涉及到不同品种杂交犬的最佳绝育年龄。
Abstract:
Neutering (including spaying) of male and female dogs in the first year after birth has become routine in the U.S. and much of Europe, but recent research reveals that for …
>>>
Neutering (including spaying) of male and female dogs in the first year after birth has become routine in the U.S. and much of Europe, but recent research reveals that for some dog breeds, neutering may be associated with increased risks of debilitating joint disorders and some cancers, complicating pet owners' decisions on neutering. The joint disorders include hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers include lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. In previous studies on the Golden Retriever, Labrador Retriever and German Shepherd Dog, neutering before a year of age was associated with increased risks of one or more joint disorders, 2-4 times that of intact dogs. The increase was particularly seen with dogs neutered by 6 months of age. In female Golden Retrievers, there was an increase in one or more of the cancers followed to about 2-4 times that of intact females with neutering at any age. The goal of the present study was to expand and use the same data collection and analyses to cover an additional 29 breeds, plus three varieties of Poodles. There were major breed differences in vulnerability to neutering, both with regard to joint disorders and cancers. In most cases, the caregiver can choose the age of neutering without increasing the risks of these joint disorders or cancers. Small-dog breeds seemed to have no increased risks of joint disorders associated with neutering, and in only two small breeds (Boston Terrier and Shih Tzu) was there a significant increase in cancers. To assist pet owners and veterinarians in deciding on the age of neutering a specific dog, guidelines that avoid increasing the risks of a dog acquiring these joint disorders or cancers are laid out for neutering ages on a breed-by-breed and sex basis.
<<<
翻译
523.
徐炳祥
(2023-02-27 14:05):
#paper doi: 10.1186/gb-2012-13-10-r98, 2012, CHANCE: comprehensive software for quality control and validation of ChIP-seq data。ChIP-seq是目前解析特定蛋白质在基因组上结合位点的最流行高通量方法,也是表观遗传学中的常用技术。这篇旧文回顾了ChIP-seq中常见的实验误差,包括抗体的活性,免疫共沉淀反应的效率,PCR反应引起的偏倚,文库制备和测序过程引入的误差等。并针对每一项给出了可行的评估策略,其附带工具对ChIP-seq文库的质量检查和失败文库的归因等工作都是有益的。
Abstract:
ChIP-seq is a powerful method for obtaining genome-wide maps of protein-DNA interactions and epigenetic modifications. CHANCE (CHip-seq ANalytics and Confidence Estimation) is a standalone package for ChIP-seq quality control and …
>>>
ChIP-seq is a powerful method for obtaining genome-wide maps of protein-DNA interactions and epigenetic modifications. CHANCE (CHip-seq ANalytics and Confidence Estimation) is a standalone package for ChIP-seq quality control and protocol optimization. Our user-friendly graphical software quickly estimates the strength and quality of immunoprecipitations, identifies biases, compares the user's data with ENCODE's large collection of published datasets, performs multi-sample normalization, checks against quantitative PCR-validated control regions, and produces informative graphical reports. CHANCE is available at https://github.com/songlab/chance.
<<<
翻译
524.
笑对人生
(2023-02-26 23:52):
#paper doi: 10.1016/j.cell.2017.10.001. Epub 2017 Oct 26. McGranahan N, et al. Allele-Specific HLA Loss and Immune Escape in Lung Cancer Evolution. Cell. 2017 Nov 30;171(6):1259-1271.e11.
背景:CD8+ T细胞在机体内的杀伤肿瘤的免疫应答起到至关重要的作用。肿瘤细胞表面的肿瘤抗原并不能直接激活CD8+ T细胞,而必须经抗原提呈细胞(APC)摄入后加工成短肽,并通过表面的MHC-I类分子呈递至CD8+ T细胞。因此,MHC-抗原肽-TCR复合物的形成是CD8+ T细胞激活肿瘤免疫杀伤的关键一步(后续还需要有共刺激分子提供的第二信号,例如CD28)。人类组织相容性复合体(major histocompatibility complex,MHC)是一组编码动物主要组织相容性抗原基因群的统称。人类白细胞抗原(human leucocyte antigen,HLA)是MHC的表达产物。HLA I类分子存在于所有有核细胞(含血小板和网织红细胞)表面。过去的研究表明,HLA的杂合性缺失(loss of heterozygosity in human leukocyte antigen ,LOHHLA)会影响T细胞的肿瘤抗原识别,导致肿瘤免疫逃逸。人体大部分细胞都含有两套HLA分子编码基因,它们分别来自父本和母本,如果HLA发生LOH,则意味着其中一套的编码基因可能发生完全或部分丢失。每个人的基因组包含多达6种不同HLA I类分子的等位基因,它们由三个基因(HLA-A,HLA-B和HLA-C)编码,位于6号染色体上。
研究内容:本研究开发一个基于高通量测序数据,专门计算HLA等位基因拷贝数变化,用于发现HLA的LOH的计算工具,名为LOHHLA。LOHHLA的主要分析流程包括:(1)从来自肿瘤和正常对照的样本的bam文件中提取HLA区域的reads,并转换成fastq文件。(2)将提取的reads重新比对到多个HLA等位基因区域,利用OptiType或Polysolver进行HLA分型。利用samtools计算mpileup,每一个比对位点的覆盖深度。(3)根据每个位点的测序深度的不同,确定同源HLA等位基因的多态性位点(call SNP)。(4)获取HLA等位基因区域的logR(tumor/normal coverage ratio,肿瘤组织和正常组织深度的比值)和BAF(类似VAF,对于每个多态性位点,HLA allele 1深度/(HLA allel1深度+HLA allel2))。(5)在考虑肿瘤纯度和倍性的情况下,对每个HLA基因计算HLA等位基因拷贝数变化。
本文应用该工具,在来自TRACERx队列的90位早期非小细胞肺癌(NSCLCs)患者中,发现40%(36/90)的患者存在HLA的LOH。进一步地,这些HLA的LOH与亚克隆新抗原负荷升高、APOBEC介导的体细胞突变产生、毒性T细胞活性增加以及肿瘤PD-L1表达阳性相关。
Abstract:
Immune evasion is a hallmark of cancer. Losing the ability to present neoantigens through human leukocyte antigen (HLA) loss may facilitate immune evasion. However, the polymorphic nature of the locus …
>>>
Immune evasion is a hallmark of cancer. Losing the ability to present neoantigens through human leukocyte antigen (HLA) loss may facilitate immune evasion. However, the polymorphic nature of the locus has precluded accurate HLA copy-number analysis. Here, we present loss of heterozygosity in human leukocyte antigen (LOHHLA), a computational tool to determine HLA allele-specific copy number from sequencing data. Using LOHHLA, we find that HLA LOH occurs in 40% of non-small-cell lung cancers (NSCLCs) and is associated with a high subclonal neoantigen burden, APOBEC-mediated mutagenesis, upregulation of cytolytic activity, and PD-L1 positivity. The focal nature of HLA LOH alterations, their subclonal frequencies, enrichment in metastatic sites, and occurrence as parallel events suggests that HLA LOH is an immune escape mechanism that is subject to strong microenvironmental selection pressures later in tumor evolution. Characterizing HLA LOH with LOHHLA refines neoantigen prediction and may have implications for our understanding of resistance mechanisms and immunotherapeutic approaches targeting neoantigens. VIDEO ABSTRACT.
<<<
翻译
525.
李翛然
(2023-02-26 22:56):
#paper Klippel-Feil Syndrome: Pathogenesis, Diagnosis, and Management doi: 10.1093/eurheartj/ehab424 这篇文章主要讲了先天性脊柱畸形 klippel-feil综合症一些活跃突变和关键性信号通路的研究。 与一般的假设不同,传统普遍认为先天性脊柱畸形一般都是与脊柱神经系统相关的调控基因有关。但实际上,从Kippel-feil综合症,患者同样具有其他疾病的显著特征。 带来一些新的思路
Abstract:
AIMS: The aim of this study was to determine the frequency of heterozygous truncating ALPK3 variants (ALPK3tv) in patients with hypertrophic cardiomyopathy (HCM) and confirm their pathogenicity using burden testing …
>>>
AIMS: The aim of this study was to determine the frequency of heterozygous truncating ALPK3 variants (ALPK3tv) in patients with hypertrophic cardiomyopathy (HCM) and confirm their pathogenicity using burden testing in independent cohorts and family co-segregation studies.METHODS AND RESULTS: In a discovery cohort of 770 index patients with HCM, 12 (1.56%) were heterozygous for ALPK3tv [odds ratio(OR) 16.11, 95% confidence interval (CI) 7.94-30.02, P = 8.05e-11] compared to the Genome Aggregation Database (gnomAD) population. In a validation cohort of 2047 HCM probands, 32 (1.56%) carried heterozygous ALPK3tv (OR 16.17, 95% CI 10.31-24.87, P < 2.2e-16, compared to gnomAD). Combined logarithm of odds score in seven families with ALPK3tv was 2.99. In comparison with a cohort of genotyped patients with HCM (n = 1679) with and without pathogenic sarcomere gene variants (SP+ and SP-), ALPK3tv carriers had a higher prevalence of apical/concentric patterns of hypertrophy (60%, P < 0.001) and of a short PR interval (10%, P = 0.009). Age at diagnosis and maximum left ventricular wall thickness were similar to SP- and left ventricular systolic impairment (6%) and non-sustained ventricular tachycardia (31%) at baseline similar to SP+. After 5.3 ± 5.7 years, 4 (9%) patients with ALPK3tv died of heart failure or had cardiac transplantation (log-rank P = 0.012 vs. SP- and P = 0.425 vs. SP+). Imaging and histopathology showed extensive myocardial fibrosis and myocyte vacuolation.CONCLUSIONS: Heterozygous ALPK3tv are pathogenic and segregate with a characteristic HCM phenotype.
<<<
翻译
526.
姗姗来迟
(2023-02-16 20:44):
#paper https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4247187 Hierarchical Reasoning Based on Perception Action Cycle for Visual Question Answering
- 受PAC机制的启发,设计了HIPA。HIPA遵循一种分层模式,通过对两种模态使用注意力模块来独立地解释视觉和语言特征,然后将聚合的特征传递到推理循环中。
- 受人类感知心理过程的启发,HIPA提出将视觉理解分为注意、组织和理解三个阶段。视觉理解的划分促进了对视觉特征的框架理解。
- 使用余弦相似度和曼哈顿距离的标准差作为视觉和语言特征的评价指标。
SSRN Electronic Journal,
2022.
DOI: 10.2139/ssrn.4247187
Abstract:
Recent visual question answering (VQA) frameworks employ different combinations of attention techniques to derive a correct answer. Attention techniques in vision-language tasks have mostly achieved success through the improvement of …
>>>
Recent visual question answering (VQA) frameworks employ different combinations of attention techniques to derive a correct answer. Attention techniques in vision-language tasks have mostly achieved success through the improvement of local features for both modalities. Attention as a concept is heavily established by human cognition mechanism. Different combinations of attention techniques are not well proven as a means of human cognition. Neural networks were originally inspired by the structure of the human brain. Many researchers have recently resorted to frameworks that resemble the human brain, and their models have achieved high performance. To this end, we aim to consider a framework that utilizes human biological and psychological concepts to achieve a good understanding of vision and language modalities. In this view, we introduce a hierarchical reasoning based on a perception action cycle (HIPA) framework to tackle VQA tasks. It integrates the reasoning process of multi-modalities with the perception action cycle (PAC), which explains the learning mechanism of humans about the surrounding world. It comprehends the visual modality through three phases of reasoning: object-level attention, organization, and interpretation. It comprehends the language modality through word-level attention, interpretation, and conditioning. Subsequently, vision and language modalities are interpreted dependently in a cyclic and hierarchical way throughout the entire framework. For further assessment of the visual and language features, we argue that image-question pairs of the same answer ought to have similar visual and language features eventually. As a result, we conduct visual and language feature evaluation experiments using metrics such as standard deviation of cosine similarity and Manhattan distance. We show that employing PAC in our framework improves the standard deviation compared with other VQA frameworks. For further assessment, we also test the novel proposed HIPA on the visual relationship detection (VRD) tasks. The proposed method achieves the state-of-the-art results on the TDIUC and VRD datasets and obtains competitive results on the VQA 2.0 dataset.
<<<
翻译
527.
张德祥
(2023-02-10 20:03):
#paper https://doi.org/10.48550/arXiv.2210.15889 Towards Data-and Knowledge-Driven Artificial Intelligence: A Survey on Neuro-Symbolic Computing 神经符号计算 (NeSy) 追求认知的符号和统计范式的整合,多年来一直是人工智能 (AI) 的活跃研究领域。由于 NeSy 有望调和符号表示的推理和可解释性优势以及神经网络中的稳健学习,它可能会成为下一代 AI 的催化剂。在本文中,我们系统地概述了 NeSy AI 研究的重要和最新进展。首先,我们介绍了这一领域的研究历史,涵盖了早期的工作和基础。我们进一步讨论背景概念并确定 NeSy 发展背后的关键驱动因素。之后,我们根据强调该研究范式的几个主要特征对最近具有里程碑意义的方法进行了分类,包括神经符号整合、知识表示、知识嵌入和功能。然后,我们简要讨论现代 NeSy 方法在几个领域的成功应用。最后,我们确定了未解决的问题以及潜在的未来研究方向。这项调查有望帮助新的研究人员进入这个快速发展的领域,并加速向数据和知识驱动的 AI 迈进。
arXiv,
2022.
DOI: 10.48550/arXiv.2210.15889
Abstract:
Neural-symbolic computing (NeSy), which pursues the integration of the symbolic and statistical paradigms of cognition, has been an active research area of Artificial Intelligence (AI) for many years. As NeSy …
>>>
Neural-symbolic computing (NeSy), which pursues the integration of the symbolic and statistical paradigms of cognition, has been an active research area of Artificial Intelligence (AI) for many years. As NeSy shows promise of reconciling the advantages of reasoning and interpretability of symbolic representation and robust learning in neural networks, it may serve as a catalyst for the next generation of AI. In the present paper, we provide a systematic overview of the important and recent developments of research on NeSy AI. Firstly, we introduce study history of this area, covering early work and foundations. We further discuss background concepts and identify key driving factors behind the development of NeSy. Afterward, we categorize recent landmark approaches along several main characteristics that underline this research paradigm, including neural-symbolic integration, knowledge representation, knowledge embedding, and functionality. Then, we briefly discuss the successful application of modern NeSy approaches in several domains. Finally, we identify the open problems together with potential future research directions. This survey is expected to help new researchers enter this rapidly-developing field and accelerate progress towards data-and knowledge-driven AI.
<<<
翻译
528.
龙海晨
(2023-02-05 17:58):
#paper Feng H, Cao B, Peng X, Wei Q. Cancer-associated fibroblasts strengthen cell proliferation and EGFR TKIs resistance through aryl hydrocarbon receptor dependent signals in non-small cell lung cancer. BMC Cancer. 2022 Jul 13;22(1):764. doi: 10.1186/s12885-022-09877-7. PMID: 35831824; PMCID: PMC9281029.文章属于研究肿瘤的领域。进一步描述了CAF在癌症EGFR-TKIs耐药性发展中的作用。阐述了CAF与EGFR TKIs耐药相关的潜在机制,其依赖于Kyn/AhR/AKT/ERK信号通路。阻断AhR可有效改善EGFR TKIs的结果,为临床治疗癌症提供了一种新的策略。
Abstract:
The tumor microenvironment is a dynamic cellular milieu that interacts with cancer cells and promotes tumor progression and metastasis. However, the specific mechanisms by which the tumor microenvironment impacts cancer …
>>>
The tumor microenvironment is a dynamic cellular milieu that interacts with cancer cells and promotes tumor progression and metastasis. However, the specific mechanisms by which the tumor microenvironment impacts cancer cells' behaviors remain poorly understood. In this study, enriched cancer-associated fibroblasts (CAFs) were observed in tumor tissues isolated from epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) resistant non-small cell lung cancer (NSCLC) patients. CAFs isolated from tumor tissues were capable of producing tryptophan metabolite kynurenine (Kyn), which significantly increased the proliferation and EGFR TKIs resistance of NSCLC cells. In this study, it was further observed that the activation of tryptophan 2,3-dioxygenase (TDO) in CAFs, resulted in the enhanced capability of tryptophan metabolism in them compared to normal fibroblasts. As a result, Kyn produced by CAFs facilitated the up-regulation of Aryl Hydrocarbon Receptor (AhR) signals in NSCLC, thereby resulting in the downstream ATK and ERK signaling pathways activation. Finally, inhibition of AhR signals efficiently prevented tumor growth and development of EGFR TKIs resistance, eventually improved the outcome of EGFR TKIs, and described a promising therapeutic strategy for NSCLC.
<<<
翻译
529.
DeDe宝
(2023-02-01 00:18):
#paper https://doi.org/10.1016/j.neuroimage.2021.118723. NeuroImage 2018. Structural connectivity-based segmentation of the human entorhinal cortex
在啮齿动物中,将内嗅皮层分割为内侧(MEC)与外侧(LEC)具有明确的定义和特征。然而,在人类中,MEC和LEC的对应确切位置却仍然不确定。之前功能性磁共振成像 (fMRI) 研究已将人类内嗅皮层细分为后内侧 (pmEC) 和前外侧 (alEC)部分,但是成像方式和种子区域(seed)对划分结果的影响仍不明确。本研究使用扩散张量成像(DTI) 和概率纤维束成像,根据与已知选择性投射到的其他大脑区域的差异连接来分割人类内嗅皮层的MEC和LEC。我们将 MEC定义为与前下托和压后皮层(RSC) 的联系更紧密的内嗅皮层,LEC定义为与远端 CA1、近端dCA1pSub)以及外侧眶额叶皮层(OFC) 的联系更紧密的内嗅皮层。尽管我们的DTI分割比之前的 fMRI 研究具有更大的内侧-外侧成分,但我们的结果表明人类 MEC 和 LEC 同系物具有朝向后-前和内侧-外侧轴的边界,支持 pmEC 后内侧 (pmEC) 和前外侧 (alEC)的划分方式。
Abstract:
The medial (MEC) and lateral entorhinal cortex (LEC), widely studied in rodents, are well defined and characterized. In humans, however, the exact locations of their homologues remain uncertain. Previous functional …
>>>
The medial (MEC) and lateral entorhinal cortex (LEC), widely studied in rodents, are well defined and characterized. In humans, however, the exact locations of their homologues remain uncertain. Previous functional magnetic resonance imaging (fMRI) studies have subdivided the human EC into posteromedial (pmEC) and anterolateral (alEC) parts, but uncertainty remains about the choice of imaging modality and seed regions, in particular in light of a substantial revision of the classical model of EC connectivity based on novel insights from rodent anatomy. Here, we used structural, not functional imaging, namely diffusion tensor imaging (DTI) and probabilistic tractography to segment the human EC based on differential connectivity to other brain regions known to project selectively to MEC or LEC. We defined MEC as more strongly connected with presubiculum and retrosplenial cortex (RSC), and LEC as more strongly connected with distal CA1 and proximal subiculum (dCA1pSub) and lateral orbitofrontal cortex (OFC). Although our DTI segmentation had a larger medial-lateral component than in the previous fMRI studies, our results show that the human MEC and LEC homologues have a border oriented both towards the posterior-anterior and medial-lateral axes, supporting the differentiation between pmEC and alEC.
<<<
翻译
530.
王昊
(2023-01-31 23:53):
#paper Learned Image Compression with Discretized Gaussian Mixture Likelihoods and Attention Modules http://arxiv.org/abs/2001.01568 Zhengxue Cheng, Heming Sun, Masaru Takeuchi, and Jiro Katto. 2020. Learned Image Compression with Discretized Gaussian Mixture Likelihoods and Attention Modules. Retrieved January 31, 2023. VCM图像编码基线方法(cheng2020网络),用于机器视觉编码的特征提取阶段,是图像压缩方法类算法。作者提出使用离散的高斯混合似然来参数化潜在表示的分布,可以获得更准确和灵活的概率模型。此外,作者还使用attention module来提高网络对图像中复杂区域的关注能力。具体地,作者提出使用离散高斯混合模型来对latent representation进行熵估计,这样可以对y提供多个最可能的均值,而每一个mixture的方差可以更小,达到的效果是实现更准确的概率模型,节约编码y所需要的比特数。第二,作者还加入了简化版的attention modules,可以提高网络对于non-zero responses,即复杂区域的关注,同时不引入过多的训练复杂度。
arXiv,
2020.
Abstract:
Image compression is a fundamental research field and many well-known compression standards have been developed for many decades. Recently, learned compression methods exhibit a fast development trend with promising results. …
>>>
Image compression is a fundamental research field and many well-known compression standards have been developed for many decades. Recently, learned compression methods exhibit a fast development trend with promising results. However, there is still a performance gap between learned compression algorithms and reigning compression standards, especially in terms of widely used PSNR metric. In this paper, we explore the remaining redundancy of recent learned compression algorithms. We have found accurate entropy models for rate estimation largely affect the optimization of network parameters and thus affect the rate-distortion performance. Therefore, in this paper, we propose to use discretized Gaussian Mixture Likelihoods to parameterize the distributions of latent codes, which can achieve a more accurate and flexible entropy model. Besides, we take advantage of recent attention modules and incorporate them into network architecture to enhance the performance. Experimental results demonstrate our proposed method achieves a state-of-the-art performance compared to existing learned compression methods on both Kodak and high-resolution datasets. To our knowledge our approach is the first work to achieve comparable performance with latest compression standard Versatile Video Coding (VVC) regarding PSNR. More importantly, our approach generates more visually pleasant results when optimized by MS-SSIM. This project page is at this https URL this https URL
<<<
翻译
531.
Ricardo
(2023-01-31 23:52):
#paper doi:https://doi.org/10.1038/s41592-022-01703-z Multifaceted atlases of the human brain in its infancy 脑图谱是整合、处理和分析从不同个体、来源和尺度收集的大脑特征的空间参考。这篇发表于nature methods的文章介绍了一组关于脑皮层-脑体积的联合脑图谱,以时空密集的方式绘制了从两周到两岁的人脑产后发育轨迹。这套特异性图谱捕捉了早期大脑发育的关键特征,因此有助于识别正常发育轨迹的异常。这些图谱将促进绘制婴儿大脑的不同特征,从而为精确量化皮层和皮层下变化提供一个共同的参考框架,从而增强我们对早期结构和功能发展的理解。
IF:36.100Q1
Nature methods,
2023-01.
DOI: 10.1038/s41592-022-01703-z
PMID: 36585454
PMCID:PMC9834057
Abstract:
Brain atlases are spatial references for integrating, processing, and analyzing brain features gathered from different individuals, sources, and scales. Here we introduce a collection of joint surface-volume atlases that chart …
>>>
Brain atlases are spatial references for integrating, processing, and analyzing brain features gathered from different individuals, sources, and scales. Here we introduce a collection of joint surface-volume atlases that chart postnatal development of the human brain in a spatiotemporally dense manner from two weeks to two years of age. Our month-specific atlases chart normative patterns and capture key traits of early brain development and are therefore conducive to identifying aberrations from normal developmental trajectories. These atlases will enhance our understanding of early structural and functional development by facilitating the mapping of diverse features of the infant brain to a common reference frame for precise multifaceted quantification of cortical and subcortical changes.
<<<
翻译
532.
笑对人生
(2023-01-31 23:51):
#paper Tan J, et al. Cell-type-specific prediction of 3D chromatin organization enables high-throughput in silico genetic screening. Nat Biotechnol. 2023 Jan 9. doi: 10.1038/s41587-022-01612-8.
在过去,三维基因组学的发展已经极大地拓宽了人们对染色质空间结构和相关构象变化对基因表达的影响。然而,受限于时间和技术成本的原因,针对特定细胞类型类型的染色质重塑事件的研究仍存在巨大挑战。本研究利用7份公开的小鼠和人的Hi-C数据,基于Transformer的多模态深度学习框架,以DNA序列信息、CTCF结合状态和ATAC-seq密度特征(非peak特征)作为输入,二维的Hi-C矩阵作为输出,构建了一个名为C.Origami,具有细胞类型特异性的三维基因组构象变化预测模型。该模型不仅de novo预测特定细胞类型的不同层次的基因组结构,而且还可以预测可能影响染色质构象的DNA元件,以及发现导致疾病发生的染色质重塑调控事件。
Abstract:
Investigating how chromatin organization determines cell-type-specific gene expression remains challenging. Experimental methods for measuring three-dimensional chromatin organization, such as Hi-C, are costly and have technical limitations, restricting their broad application …
>>>
Investigating how chromatin organization determines cell-type-specific gene expression remains challenging. Experimental methods for measuring three-dimensional chromatin organization, such as Hi-C, are costly and have technical limitations, restricting their broad application particularly in high-throughput genetic perturbations. We present C.Origami, a multimodal deep neural network that performs de novo prediction of cell-type-specific chromatin organization using DNA sequence and two cell-type-specific genomic features-CTCF binding and chromatin accessibility. C.Origami enables in silico experiments to examine the impact of genetic changes on chromatin interactions. We further developed an in silico genetic screening approach to assess how individual DNA elements may contribute to chromatin organization and to identify putative cell-type-specific trans-acting regulators that collectively determine chromatin architecture. Applying this approach to leukemia cells and normal T cells, we demonstrate that cell-type-specific in silico genetic screening, enabled by C.Origami, can be used to systematically discover novel chromatin regulation circuits in both normal and disease-related biological systems.
<<<
翻译
533.
彬
(2023-01-31 23:40):
#paper Dachs N, Upadhyay M, Hannemann E. Quantitative trait locus for calving traits on Bos taurus autosome 18 in Holstein cattle is embedded in a complex genomic region. J Dairy Sci. 2023 Jan 27:S0022-0302(23)00025-5. doi: 10.3168/jds.2021-21625. 已有研究显示荷斯坦-里弗斯牛及其杂交牛18号染色体上的数量性状与其产犊质量有关,但还未确定具体的相关基因。该研究通过分析大样本的群体基因分型数据、全基因组测序数据、荷斯坦-里弗斯牛动物样本的基因组组装,确定了与畅读质量相关的数量性状位点95%置信区间在18号染色体58.34 至 59.43 Mbp之间。其中有4个SNP与QTL单倍型为连锁不平衡。接下来的工作可能就是分析相关基因或与繁殖性状进行关联分析等等。该研究提供的数据全面描述了基因组特征,这些特征也可能与其他各种牛品种和家畜物种中的其他此类难以捉摸的QTL相关。
Abstract:
Although the quantitative trait locus (QTL) on chromosome 18 (BTA18) associated with paternal calving ease and stillbirth in Holstein Friesian cattle and its cross has been known for over 20 …
>>>
Although the quantitative trait locus (QTL) on chromosome 18 (BTA18) associated with paternal calving ease and stillbirth in Holstein Friesian cattle and its cross has been known for over 20 years, to our knowledge, the exact causal genetic sequence has yet escaped identification. The aim of this study was to re-examine the region of the published QTL on BTA18 and to investigate the possible reasons behind this elusiveness. For this purpose, we carried out a combined linkage disequilibrium and linkage analysis using genotyping data of 2,697 German Holstein Friesian (HF) animals and subsequent whole-genome sequencing (WGS) data analyses and genome assembly of HF samples. We confirmed the known QTL in the 95% confidence interval of 1.089 Mbp between 58.34 and 59.43 Mbp on BTA18. Additionally, these 4 SNPs in the near-perfect linkage disequilibrium with the QTL haplotype were identified: rs381577268 (on 57,816,137 bp, C/T), rs381878735 (on 59,574,329 bp, A/T), rs464221818 (on 59,329,176 bp, C/T), and rs472502785 (on 59,345,689 bp, T/C). Search for the causal mutation using short and long-read sequences, and methylation data of the BTA18 QTL region did not reveal any candidates though. The assembly showed problems in the region, as well as an abundance of segmental duplications within and around the region. Taking the QTL of BTA18 in Holstein cattle as an example, the data presented in this study comprehensively characterize the genomic features that could also be relevant for other such elusive QTL in various other cattle breeds and livestock species as well.
<<<
翻译
534.
半面阳光
(2023-01-31 23:38):
#paper doi: 10.1016/j.pcl.2015.03.004. Pediatr Clin North Am, 2015, Prader-Willi, Angelman, and 15q11-q13 Duplication Syndromes, 15号染色体区段15q11-q13上的缺失或者重复会导致三种综合征,Prader-Willi 综合征, Angelman 综合征和 15q11-q13 duplication 综合征。这篇综述文章总结了这三种综合征的临床背景信息、遗传机制、诊断策略以及治疗方案。通过这篇文章能够清楚地了解这三种综合征之间的异同。
IF:2.100Q2
Pediatric clinics of North America,
2015-Jun.
DOI: 10.1016/j.pcl.2015.03.004
PMID: 26022164
Abstract:
Three distinct neurodevelopmental disorders arise primarily from deletions or duplications that occur at the 15q11-q13 locus: Prader-Willi syndrome, Angelman syndrome, and 15q11-q13 duplication syndrome. Each of these disorders results from …
>>>
Three distinct neurodevelopmental disorders arise primarily from deletions or duplications that occur at the 15q11-q13 locus: Prader-Willi syndrome, Angelman syndrome, and 15q11-q13 duplication syndrome. Each of these disorders results from the loss of function or overexpression of at least 1 imprinted gene. This article discusses the clinical background, genetic cause, diagnostic strategy, and management of each of these 3 disorders.
<<<
翻译
535.
cellsarts
(2023-01-31 23:31):
#paper Comparison of Different Packing Materials for the Biofiltration of Air Toxics DOI 10.1023/A:1021240500817 比较了四种不同的生物过滤器生物除臭滤塔的填料(两种多孔陶瓷、珍珠岩和开孔聚氨酯泡沫)去除废气中甲苯蒸汽的效果。重点是评估各填料在相对较短的气体保留时间(13.5秒和27秒)下的性能。反应器最初是作为生物滴滤器运行的,连续进料和滴入营养液。在观察到生物质生物滴滤床明显堵塞后,操作模式切换为仅定期供应矿物营养物质的生物过滤。这利于废气处理系统的稳定的运行,调查的过程持续超过6个月。牛骨瓷(CBP)是一种含有微量元素和宏量元素的陶瓷材料,其填充反应器表现出最高的性能。临界负荷(即发生95%去除率的负荷)为29克/m3/小时1,气体保留时间为13.5秒;66克/m3/小时,气体保留时间为27秒。在长期实验后,从反应器中取出填料并进行检查。将反应器分为顶部、中间和底部三个部分,以确定生物质是否存在空间分异。测定包括双染色技术,以计数总微生物和活微生物,并测定水分,蛋白质和干重含量。采用变性梯度凝胶电泳进行微生物群落分析。结果表明,大多数反应器都有相当比例的非活性生物质。相比之下,牛骨瓷CBP填料生物滤池的活性生物量密度明显较高,这可能是其去除甲苯性能较高的原因。分析表明,良好的物质条件和CBP缓慢释放的养分为工艺培养提供了较好的环境条件。
Abstract:
Modern CNNs are learning the weights of vast numbers of convolutional operators. In this paper, we raise the fundamental question if this is actually necessary. We show that even in …
>>>
Modern CNNs are learning the weights of vast numbers of convolutional operators. In this paper, we raise the fundamental question if this is actually necessary. We show that even in the extreme case of only randomly initializing and never updating spatial filters, certain CNN architectures can be trained to surpass the accuracy of standard training. By reinterpreting the notion of pointwise (1×1) convolutions as an operator to learn linear combinations (LC) of frozen (random) spatial filters, we are able to analyze these effects and propose a generic LC convolution block that allows tuning of the linear combination rate. Empirically, we show that this approach not only allows us to reach high test accuracies on CIFAR and ImageNet but also has favorable properties regarding model robustness, generalization, sparsity, and the total number of necessary weights. Additionally, we propose a novel weight sharing mechanism, which allows sharing of a single weight tensor between all spatial convolution layers to massively reduce the number of weights.
<<<
翻译
536.
前进
(2023-01-31 23:30):
#paper Rethinking 1x1 Convolutions: Can we train CNNs with Frozen Random Filters? arXiv:2301.11360
本文引入了一种新的卷积块,计算(冻结随机)滤波器的可学习线性组合(LC),并由此提出 LCResNets,还提出一种新的权重共享机制,可大幅减少权重的数量。在本文中,即使在仅随机初始化且从不更新空间滤波器的极端情况下,某些CNN架构也可以被训练以超过标准训练的精度。通过将逐点(1x1)卷积的概念重新解释为学习冻结(随机)空间滤波器的线性组合(LC)的算子,这种方法不仅可以在CIFAR和ImageNet上达到较高的测试精度,而且在模型鲁棒性、泛化、稀疏
性和所需权重的总数方面具有良好。此外本文提出了一种新的权重共享机制,该机制允许在所有空间卷积层之间共享单个权重张量,以大幅减少权重的数量。
arXiv,
2023.
Abstract:
Modern CNNs are learning the weights of vast numbers of convolutional operators. In this paper, we raise the fundamental question if this is actually necessary. We show that even in …
>>>
Modern CNNs are learning the weights of vast numbers of convolutional operators. In this paper, we raise the fundamental question if this is actually necessary. We show that even in the extreme case of only randomly initializing and never updating spatial filters, certain CNN architectures can be trained to surpass the accuracy of standard training. By reinterpreting the notion of pointwise (1×1) convolutions as an operator to learn linear combinations (LC) of frozen (random) spatial filters, we are able to analyze these effects and propose a generic LC convolution block that allows tuning of the linear combination rate. Empirically, we show that this approach not only allows us to reach high test accuracies on CIFAR and ImageNet but also has favorable properties regarding model robustness, generalization, sparsity, and the total number of necessary weights. Additionally, we propose a novel weight sharing mechanism, which allows sharing of a single weight tensor between all spatial convolution layers to massively reduce the number of weights.
<<<
翻译
537.
姗姗来迟
(2023-01-31 23:24):
#paper
PageNet: Towards End-to-End Weakly Supervised Page-Level Handwritten Chinese Text Recognition
https://link.springer.com/article/10.1007/s11263-022-01654-0?utm_source=xmol&utm_content=meta
该工作针对篇幅级手写中文文本识别问题,提出了端到端弱监督的方法PageNet。该方法的主要优势在于:(1)从一个新的角度解决篇幅级中文文本识别问题——检测识别单字并预测单字间的阅读顺序。(2)模型可以弱监督地训练。对于真实数据仅需要标注文本,不需要任何边界框标注,极大地降低了数据的标注成本。(3)尽管只需要文本标注信息,模型却可以预测出单字级和文本行级的检测和识别结果。(4)该方法深入研究篇幅级文本识别中的阅读顺序问题,所提出的阅读顺序模块可以处理多方向文本、弯曲文本等复杂的阅读顺序。
Abstract:
Handwritten Chinese text recognition (HCTR) has been an active research topic for decades. However, most previous studies solely focus on the recognition of cropped text line images, ignoring the error …
>>>
Handwritten Chinese text recognition (HCTR) has been an active research topic for decades. However, most previous studies solely focus on the recognition of cropped text line images, ignoring the error caused by text line detection in real-world applications. Although some approaches aimed at page-level text recognition have been proposed in recent years, they either are limited to simple layouts or require very detailed annotations including expensive line-level and even character-level bounding boxes. To this end, we propose PageNet for end-to-end weakly supervised page-level HCTR. PageNet detects and recognizes characters and predicts the reading order between them, which is more robust and flexible when dealing with complex layouts including multi-directional and curved text lines. Utilizing the proposed weakly supervised learning framework, PageNet requires only transcripts to be annotated for real data; however, it can still output detection and recognition results at both the character and line levels, avoiding the labor and cost of labeling bounding boxes of characters and text lines. Extensive experiments conducted on five datasets demonstrate the superiority of PageNet over existing weakly supervised and fully supervised page-level methods. These experimental results may spark further research beyond the realms of existing methods based on connectionist temporal classification or attention. The source code is available at https://github.com/shannanyinxiang/PageNet.
<<<
翻译
538.
钟鸣
(2023-01-31 23:18):
#paper Sex Matters: Male Hamsters Are More Susceptible to Lethal Infection with Lower Doses of Pathogenic Leptospira than Female Hamsters https://doi.org/10.1128/IAI.00369-18 过去的研究中发现女性比男性更容易感染钩端螺旋体,但现实生活中男性感染钩端螺旋体的发病率和重症率却高于女性,为解释这个矛盾的现象,作者使用仓鼠做了动物实验。使用人工攻毒的方式建立动物模型,他们发现不同性别动物感染钩端螺旋体后确实存在差异,但是这种差异仅在感染低剂量时才能够体现出来,即在感染低剂量病原时雄性具有更严重的症状,包括存活率和病理评分以及病原负荷(载毒量)。进一步调查发现,病理评分的差异主要存在于肾脏,并且伴随着更高的炎症因子水平。新冠病毒引起的症状在不同性别间也有差异,而且我们也早就知道男女性之间的抗炎能力存在差异。但是为什么一些病原体的致病性在不同性别间有差异但是有些没有,虽然感染病原后都会引发炎症。以及为什么钩端螺旋体引起的炎症反应差异仅存在于肾脏中?研究没有继续深入,至此戛然而止。
Abstract:
A somewhat contradictory published body of evidence suggests that sex impacts severity outcomes of human leptospirosis. In this study, we used an acute animal model of disease to analyze leptospirosis …
>>>
A somewhat contradictory published body of evidence suggests that sex impacts severity outcomes of human leptospirosis. In this study, we used an acute animal model of disease to analyze leptospirosis in male and female hamsters infected side by side with low but increasing doses of serovar Copenhageni. We found that male hamsters were considerably more susceptible to leptospirosis, given that only 6.3% survived infection, whereas 68.7% of the females survived the same infection doses. In contrast to the females, male hamsters had high burdens of in kidney and high histopathological scores after exposure to low infection doses (∼10 bacteria). In hamsters infected with higher doses of (∼10 bacteria), differences in pathogen burdens as well as cytokine and fibrosis transcript levels in kidney were not distinct between sexes. Our results indicate that male hamsters infected with are more susceptible to severe leptospirosis after exposure to lower infectious doses than females.
<<<
翻译
539.
小W
(2023-01-31 23:13):
#paper doi:https://doi.org/10.1038/s41467-022-35320-3
Tumor fractions deciphered from circulating cell-free DNA methylation for cancer early diagnosis. Nat Commun 13, 7694 (2022)
本文是清华大学团队开发的使用 cfDNA 甲基化特征来构建SRFD-Bayes诊断模型,通过去卷积混合甲基化特征来估计cfDNA的肿瘤的起源组织 (TOO),用于预测原发性肿瘤的位置和对癌症早期诊断。本文分为三个部分,使用肿瘤和正常样本甲基化数据模拟 cfdna 数据;甲基化标记物选择,使用半参考反卷积(SRFD)从血浆cfDNA甲基化谱中学习的参考数据库, 构建SRFD-Bayes 模型;在早期患者和健康个体上验证时,该模型对癌症早期检测的敏感性为86.1%,对肿瘤定位的平均准确性为76.9%,特异性为94.7%。
Abstract:
Tumor-derived circulating cell-free DNA (cfDNA) provides critical clues for cancer early diagnosis, yet it often suffers from low sensitivity. Here, we present a cancer early diagnosis approach using tumor fractions …
>>>
Tumor-derived circulating cell-free DNA (cfDNA) provides critical clues for cancer early diagnosis, yet it often suffers from low sensitivity. Here, we present a cancer early diagnosis approach using tumor fractions deciphered from circulating cfDNA methylation signatures. We show that the estimated fractions of tumor-derived cfDNA from cancer patients increase significantly as cancer progresses in two independent datasets. Employing the predicted tumor fractions, we establish a Bayesian diagnostic model in which training samples are only derived from late-stage patients and healthy individuals. When validated on early-stage patients and healthy individuals, this model exhibits a sensitivity of 86.1% for cancer early detection and an average accuracy of 76.9% for tumor localization at a specificity of 94.7%. By highlighting the potential of tumor fractions on cancer early diagnosis, our approach can be further applied to cancer screening and tumor progression monitoring.
<<<
翻译
540.
小擎子
(2023-01-31 23:12):
#paper doi:10.1038/s41467-022-35237-x Nat Commun., 2022, Sourcing thermotolerant poly(ethylene terephthalate) hydrolase scaffolds from natural diversity。将HMM方法与机器学习相结合,以鉴定PET水解酶,根据序列预测酶的最佳活性温度。从公开数据库获得序列和环境最佳生长温度(OGT),只保留OGT大于50℃的序列,对于没有OGT信息的序列,使用计算氨基酸特征的支持向量机方法训练机器学习模型(ThermoProt)来区分来自嗜热菌大于50℃的8000种蛋白和来自非嗜热菌的小于50℃的8000种蛋白。ThremProt表现出86.6%的准确率。选择了74种假定的耐热PET水解酶进行实验筛选。实验筛选出了23种热稳定酶,均未被报道,并且超过先前报道的36种酶的PET水解酶活性。
Abstract:
Enzymatic deconstruction of poly(ethylene terephthalate) (PET) is under intense investigation, given the ability of hydrolase enzymes to depolymerize PET to its constituent monomers near the polymer glass transition temperature. To …
>>>
Enzymatic deconstruction of poly(ethylene terephthalate) (PET) is under intense investigation, given the ability of hydrolase enzymes to depolymerize PET to its constituent monomers near the polymer glass transition temperature. To date, reported PET hydrolases have been sourced from a relatively narrow sequence space. Here, we identify additional PET-active biocatalysts from natural diversity by using bioinformatics and machine learning to mine 74 putative thermotolerant PET hydrolases. We successfully express, purify, and assay 51 enzymes from seven distinct phylogenetic groups; observing PET hydrolysis activity on amorphous PET film from 37 enzymes in reactions spanning pH from 4.5-9.0 and temperatures from 30-70 °C. We conduct PET hydrolysis time-course reactions with the best-performing enzymes, where we observe differences in substrate selectivity as function of PET morphology. We employed X-ray crystallography and AlphaFold to examine the enzyme architectures of all 74 candidates, revealing protein folds and accessory domains not previously associated with PET deconstruction. Overall, this study expands the number and diversity of thermotolerant scaffolds for enzymatic PET deconstruction.
<<<
翻译