PNAS Nexus最新文献_第4页

Eye tracking is more sensitive than skin conductance response in detecting mild environmental stimuli 在检测轻微环境刺激方面，眼动追踪比皮肤传导反应更灵敏

PNAS Nexus Pub Date : 2024-08-28 DOI: 10.1093/pnasnexus/pgae370

Saman Khazaei, Rose T Faghih

{"title":"Eye tracking is more sensitive than skin conductance response in detecting mild environmental stimuli","authors":"Saman Khazaei, Rose T Faghih","doi":"10.1093/pnasnexus/pgae370","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae370","url":null,"abstract":"The skin conductance (SC) and eye tracking data are two potential arousal-related psychophysiological signals that can serve as the interoceptive unconditioned response (UR) to aversive stimuli (e.g., electric shocks). The current research investigates the sensitivity of these signals in detecting mild electric shock by decoding the hidden arousal and interoceptive awareness (IA) states. While well-established frameworks exist to decode the arousal state from the SC signal, there is a lack of a systematic approach that decodes the IA state from pupillometry and eye gaze measurements. We extract the physiological-based features from eye tracking data to recover the IA-related neural activity. Employing a Bayesian filtering framework, we decode the IA state in fear conditioning and extinction experiments where mild electric shock is used. We independently decode the underlying arousal state using binary and marked point process (MPP) observations derived from concurrently collected SC data. 8 of 11 subjects present a significantly (p-value &lt; 0.001) higher IA state in trials that were always accompanied by electric shock (CS + US+) compared to trials that were never accompanied by electric shock (CS−). According to the decoded SC-based arousal state, only 5 (binary observation) and 4 (MPP observation) subjects present a significantly higher arousal state in CS + US+ trials than CS− trials. In conclusion, the decoded hidden brain state from eye tracking data better agrees with the presented mild stimuli. Tracking IA state from eye tracking data can lead to the development of contactless monitors for neuropsychiatric and neurodegenerative disorders.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Beyond monopole electrostatics in regulating conformations of intrinsically disordered proteins 单极静电之外的内在无序蛋白质构象调控技术

PNAS Nexus Pub Date : 2024-08-27 DOI: 10.1093/pnasnexus/pgae367

Michael Phillips, Murugappan Muthukumar, Kingshuk Ghosh

{"title":"Beyond monopole electrostatics in regulating conformations of intrinsically disordered proteins","authors":"Michael Phillips, Murugappan Muthukumar, Kingshuk Ghosh","doi":"10.1093/pnasnexus/pgae367","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae367","url":null,"abstract":"Conformations and dynamics of an intrinsically disordered protein (IDP) depend on its composition of charged and uncharged amino acids, and their specific placement in the protein sequence. In general, the charge (positive or negative) on an amino acid residue in the protein is not a fixed quantity. Each of the ionizable groups can exist in an equilibrated distribution of fully ionized state (monopole) and an ion-pair (dipole) state formed between the ionizing group and its counterion from the background electrolyte solution. The dipole formation (counterion condensation) depends on the protein conformation, which in turn depends on the distribution of charges and dipoles on the molecule. Consequently, effective charges of ionizable groups in the IDP backbone may differ from their chemical charges in isolation — a phenomenon termed charge-regulation. Accounting for the inevitable dipolar interactions, that have so far been ignored, and using a self-consistent procedure, we present a theory of charge-regulation as a function of sequence, temperature and ionic strength. The theory quantitatively agrees with both charge reduction and salt dependent conformation data of Prothymosin-alpha, and makes several testable predictions. We predict charged groups are less ionized in sequences where opposite charges are well mixed compared to sequences where they are strongly segregated. Emergence of dipolar interactions from charge-regulation allows spontaneous coexistence of two phases having different conformations and charge states, sensitively depending on the charge patterning. These findings highlight sequence dependent charge-regulation and its potential exploitation by biological regulators such as phosphorylation and mutations in controlling protein conformation and function.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Predicting and understanding photocatalytic CO2 reduction reaction with IR spectroscopy-based interpretable machine learning framework 利用基于红外光谱的可解释机器学习框架预测和理解光催化二氧化碳还原反应

PNAS Nexus Pub Date : 2024-08-27 DOI: 10.1093/pnasnexus/pgae339

Yanxia Wang, Yanjuan Sun, Xinyan Liu, Fan Dong

{"title":"Predicting and understanding photocatalytic CO2 reduction reaction with IR spectroscopy-based interpretable machine learning framework","authors":"Yanxia Wang, Yanjuan Sun, Xinyan Liu, Fan Dong","doi":"10.1093/pnasnexus/pgae339","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae339","url":null,"abstract":"The highly selective conversion of carbon dioxide into value-added products is extremely valuable. However, even with the aid of in situ characterization techniques, it remains challenging to directly correlate extensive spectral data carrying microscopic information with macroscopic performance. Herein, we adopted advanced machine learning (ML) approaches to establish an accurate and interpretable relationship between vibrational spectral signals and catalytic performances to uncover hidden physical insights. Focusing on photocatalytic CO2 reduction, our model is shown to effectively and accurately predict the CO production activity and selectivity based solely on the infrared (IR) spectral signals, the generalizability of which is additionally demonstrated with a new Bi5O7I photocatalytic system. More importantly, further model analysis has revealed a novel strategy to steer CO selectivity, the physical sanity of which is verified by a detailed reaction mechanism analysis. This work demonstrates the tremendous potential of machine-learned spectroscopy to efficiently identify reaction control factors, which can further lay the foundation for targeted optimization and reverse design.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An energy and information analysis method of logic gates based on stochastic thermodynamics 基于随机热力学的逻辑门能量和信息分析方法

PNAS Nexus Pub Date : 2024-08-26 DOI: 10.1093/pnasnexus/pgae365

Xiaohu Ge, Muyao Ruan, Xiaoxuan Peng, Yong Xiao, Yang Yang

引用次数: 0

Understanding the limits of binary diffusion for enhanced clay barrier design 了解二元扩散的极限，加强粘土隔离层设计

PNAS Nexus Pub Date : 2024-08-24 DOI: 10.1093/pnasnexus/pgae366

Jooyoung Im, J Carlos Santamarina

引用次数: 0

Incentivizing news consumption on social media platforms using large language models and realistic bot accounts 利用大型语言模型和逼真的机器人账户激励社交媒体平台上的新闻消费

PNAS Nexus Pub Date : 2024-08-24 DOI: 10.1093/pnasnexus/pgae368

Hadi Askari, Anshuman Chhabra, Bernhard Clemm von Hohenberg, Michael Heseltine, Magdalena Wojcieszak

{"title":"Incentivizing news consumption on social media platforms using large language models and realistic bot accounts","authors":"Hadi Askari, Anshuman Chhabra, Bernhard Clemm von Hohenberg, Michael Heseltine, Magdalena Wojcieszak","doi":"10.1093/pnasnexus/pgae368","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae368","url":null,"abstract":"Polarization, misinformation, declining trust, and wavering support for democratic norms are pressing threats to the U.S. Exposure to verified and balanced news may make citizens more resilient to these threats. This project examines how to enhance users’ exposure to and engagement with verified and ideologically balanced news in an ecologically valid setting. We rely on a two-week long field experiment on 28,457 Twitter users. We created 28 bots utilizing GPT-2 that replied to users tweeting about sports, entertainment, or lifestyle with a contextual reply containing a URL to the topic-relevant section of a verified and ideologically balanced news organization and an encouragement to follow its Twitter account. To test differential effects by gender of the bots, the treated users were randomly assigned to receive responses by bots presented as female or male. We examine whether our intervention enhances the following of news media organizations, sharing and liking of news content (determined by our extensive list of news media outlets), tweeting about politics, and liking of political content (determined using our fine-tuned RoBERTa NLP transformer-based model). Although the treated users followed more news accounts and the users in the female bot treatment liked more news content than the control, these results were small in magnitude and confined to the already politically interested users, as indicated by their pre-treatment tweeting about politics. In addition, the effects on liking and posting political content were uniformly null. These findings have implications for social media and news organizations and offer directions for pro-social computational interventions on platforms.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Cerebral microvascular changes in healthy carriers of the APOE-ε4 Alzheimer’s disease risk gene APOE-ε4 阿尔茨海默病风险基因健康携带者的脑微血管变化

PNAS Nexus Pub Date : 2024-08-24 DOI: 10.1093/pnasnexus/pgae369

Rasmus Aamand, Peter M Rasmussen, Katrine Schilling Andersen, Stine de Paoli, Eddie Weitzberg, Michael Christiansen, Torben E Lund, Leif Østergaard

{"title":"Cerebral microvascular changes in healthy carriers of the APOE-ε4 Alzheimer’s disease risk gene","authors":"Rasmus Aamand, Peter M Rasmussen, Katrine Schilling Andersen, Stine de Paoli, Eddie Weitzberg, Michael Christiansen, Torben E Lund, Leif Østergaard","doi":"10.1093/pnasnexus/pgae369","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae369","url":null,"abstract":"APOE-ε4 is a genetic risk factor for Alzheimer’s Disease (AD). AD is associated with reduced cerebral blood flow (CBF) and with microvascular changes that limit the transport of oxygen from blood into brain tissue: reduced microvascular cerebral blood volume and high relative transit time heterogeneity (RTH). Healthy APOE-ε4 carriers reveal brain regions with elevated CBF compared to carriers of the common ε3 allele. Such asymptomatic hyperemia may reflect microvascular dysfunction: a vascular disease entity characterized by suboptimal tissue oxygen uptake, rather than limited blood flow per se. Here, we used perfusion MRI to show that elevated regional CBF is accompanied by reduced CBV in healthy APOE-ε4 carriers (carriers) aged 30-70 compared to similarly aged APOE-ε3 carriers (non-carriers). Younger carriers have elevated hippocampal RTH and more extreme RTH values throughout both white matter (WM) and cortical gray matter (GM) compared to non-carriers. Older carriers have reduced WM CBF and more extreme GM RTH values than non-carriers. Across all groups, lower WM and hippocampal RTH correlate with higher educational attainment, which is associated with lower AD risk. Three days of dietary nitrate supplementation increased carriers’ WM CBF but caused older carriers to score worse on two of six aggregate neuropsychological scores. The intervention improved late recall in younger carriers and in non-carriers. The APOE-ε4 gene is associated with microvascular changes that may impair tissue oxygen extraction. We speculate that vascular risk factor control is particularly important for APOE-ε4 carriers’ healthy aging.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Two serial filters control P2X7 cation selectivity, Ser342 in the central pore and lateral acidic residues at the cytoplasmic interface 两个序列过滤器控制着 P2X7 阳离子选择性，即中央孔中的 Ser342 和胞质界面上的横向酸性残基

PNAS Nexus Pub Date : 2024-08-24 DOI: 10.1093/pnasnexus/pgae349

Fritz Markwardt, Eike Christian Schön, Michaela Raycheva, Aparna Malisetty, Sanaria Hawro Yakoob, Malte Berthold, Günther Schmalzing

{"title":"Two serial filters control P2X7 cation selectivity, Ser342 in the central pore and lateral acidic residues at the cytoplasmic interface","authors":"Fritz Markwardt, Eike Christian Schön, Michaela Raycheva, Aparna Malisetty, Sanaria Hawro Yakoob, Malte Berthold, Günther Schmalzing","doi":"10.1093/pnasnexus/pgae349","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae349","url":null,"abstract":"The human P2X7R (hP2X7R) is a homotrimeric cell surface receptor gated by extracellular ATP4- with two transmembrane helices per subunit, TM1 and TM2. A ring of three S342 residues, one from each pore-forming TM2 helix, located halfway across the membrane bilayer, functions to close and open the gate in the apo and ATP4- bound open states, respectively. The hP2X7R is selective for small inorganic cations, but can also conduct larger organic cations such as Tris+. Here, we show by voltage-clamp electrophysiology in Xenopus laevis oocytes that mutation of S342 residues to positively charged lysines decreases the selectivity for Na+ over Tris+, but maintains cation selectivity. Deep in the membrane, laterally below the S342 ring are nine acidic residues arranged as an isosceles triangle consisting of residues E14, D352, and D356 on each side, which do not move significantly during gating. When the E14K mutation is combined with lysine substitutions of D352 and/or D356, cation selectivity is lost and permeation of the small anion Cl- is allowed. Lysine substitutions of S342 together with D352 or E14 plus D356 in the acidic triangle convert the hP2X7R mutant to a fully Cl--selective ATP4--gated receptor. We conclude that the ion selectivity of wild-type hP2X7R is determined by two sequential filters in one single pathway: (1) a primary size filter, S342, in the membrane center and (2) three cation filters lateral to the channel axis, one per subunit interface, consisting of a total of nine acidic residues at the cytoplasmic interface.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Tomonaga-Luttinger liquid and quantum criticality in spin-½ antiferromagnetic Heisenberg chain C14H18CuN4O10 via Wilson ratio 自旋½反铁磁性海森堡链 C14H18CuN4O10 中通过威尔逊比的 Tomonaga-Luttinger 液体和量子临界性

PNAS Nexus Pub Date : 2024-08-23 DOI: 10.1093/pnasnexus/pgae363

Sharath Kumar Channarayappa, Sankalp Kumar, N S Vidhyadhiraja, Sumiran Pujari, M P Saravanan, Amal Sebastian, Eun Sang Choi, Shalinee Chikara, Dolly Nambi, Athira Suresh, Siddhartha Lal, D Jaiswal-Nagar

{"title":"Tomonaga-Luttinger liquid and quantum criticality in spin-½ antiferromagnetic Heisenberg chain C14H18CuN4O10 via Wilson ratio","authors":"Sharath Kumar Channarayappa, Sankalp Kumar, N S Vidhyadhiraja, Sumiran Pujari, M P Saravanan, Amal Sebastian, Eun Sang Choi, Shalinee Chikara, Dolly Nambi, Athira Suresh, Siddhartha Lal, D Jaiswal-Nagar","doi":"10.1093/pnasnexus/pgae363","DOIUrl":"https://doi.org/10.1093/pnasnexus/pgae363","url":null,"abstract":"The ground state of a one-dimensional spin-½ uniform antiferromagnetic Heisenberg chain (AfHc) is a Tomonaga-Luttinger liquid which is quantum-critical with respect to applied magnetic fields upto a saturation field μ0 Hs beyond which it transforms to a fully polarised state. Wilson ratio has been predicted to be a good indicator for demarcating these phases [Phys. Rev. B 96, 220401 (2017)]. From detailed temperature and magnetic field dependent magnetisation, magnetic susceptibility and specific heat measurements in a metalorganic complex and comparisons with field theory and quantum transfer matrix method calculations, the complex was found to be a very good realisation of a spin-½ AfHc. Wilson ratio obtained from experimentally obtained magnetic susceptibility and magnetic contribution of specific heat values was used to map the magnetic phase diagram of the uniform spin-½ AfHc over large regions of phase space demarcating Tomonaga-Luttinger liquid, saturation field quantum critical, and fully polarised states. Luttinger parameter and spinon velocity were found to match very well with the values predicted from conformal field theory.","PeriodicalId":516525,"journal":{"name":"PNAS Nexus","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Race and Superfund site remediation 种族和超级基金场地修复

PNAS Nexus Pub Date : 2024-08-23 DOI: 10.1093/pnasnexus/pgae364

Chad M Topaz, Berenize Garcia Nueva, Patrick Izidro de Souza, Jesse Schumann, Leah Shvedova, Xizhen Cai, Shaoyang Ning

引用次数: 0