检索结果-内蒙古大学图书馆

Profiling metabolome of mouse embryonic cerebrospinal fluid following maternal immune activation

Journal of Biological Chemistry 2024年第10期300卷 107749-107749页

作者： Petrova, Boryana Lacey, Tiara E. Culhane, Andrew J. Cui, Jin Brook, Jeannette R. Raskind, Alexander Misra, Aditya Lehtinen, Maria K. Kanarek, Naama Department of Pathology Boston Children's Hospital BostonMA United States Harvard Medical School BostonMA United States Graduate Program in Biological and Biomedical Sciences Harvard Medical School BostonMA United States IROA TechnologiesTM LLC Chapel HillNC United States Harvard-MIT Division of Health Sciences and Technology Massachusetts Institute of Technology CambridgeMA United States Broad Institute of Harvard and Massachusetts Institute of Technology CambridgeMA United States

The embryonic cerebrospinal fluid (eCSF) plays an essential role in the development of the central nervous system (CNS), influencing processes from neurogenesis to lifelong cognitive functions. An important process affecting eCSF composition is inflammation. Inflammation during development can be studied using the maternal immune activation (MIA) mouse model, which displays altered cytokine eCSF composition and mimics neurodevelopmental disorders including autism spectrum disorder (ASD). The limited nature of eCSF as a biosample restricts its research and has hindered our understanding of the eCSF's role in brain pathologies. Specifically, investigation of the small molecule composition of the eCSF is lacking, leaving this aspect of eCSF composition under-studied. We report here the eCSF metabolome as a resource for investigating developmental neuropathologies from a metabolic perspective. Our reference metabolome includes comprehensive MS1 and MS2 datasets and evaluates two mouse strains (CD-1 and C57Bl/6) and two developmental time points (E12.5 and E14.5). We illustrate the reference metabolome's utility by using untargeted metabolomics to identify eCSF-specific compositional changes following MIA. We uncover MIA-relevant metabolic pathways as differentially abundant in eCSF and validate changes in glucocorticoid and kynurenine pathways through targeted metabolomics. Our resource can guide future studies into the causes of MIA neuropathology and the impact of eCSF composition on brain development. © 2024 The Authors

关键词： Cerebrospinal fluid

来源：评论

学校读者我要写书评

暂无评论

Single-neuronal predictions of others' beliefs in humans(vol 591, pg 610, 2021)

引用

NATURE 2023年第7966期618卷 E25-E25页

作者： Jamali, Mohsen Grannan, Benjamin L. Fedorenko, Evelina Saxe, Rebecca Baez-Mendoza, Raymundo Williams, Ziv M. Department of Neurosurgery Massachusetts General Hospital Harvard Medical School Boston MA USA Harvard-MIT Division of Health Sciences and Technology Boston MA USA Program in Neuroscience Harvard Medical School Boston MA USA Brain and Cognitive Sciences Massachusetts Institute of Technology Boston MA USA

来源：评论

学校读者我要写书评

暂无评论

The Ceres Human Exploration and Transit Architecture (CHEATA): A Mission Architecture for Small Bodies Exploration 73

The Ceres Human Exploration and Transit Architecture (CHEATA...

引用

73rd International Astronautical Congress, IAC 2022

作者： Todd, Jessica Gentgen, Chloe Porter, Allison Bellisle, Rachel Martell, Benjamin Hoffman, Jeffrey Department of Aeronautics and Astronautics Massachusetts Institute of Technology 77 Massachusetts Ave CambridgeMA02139 United States MIT-WHOI Joint Program in Oceanography/Applied Ocean Science and Engineering Woods Hole Oceanographic Institution Woods HoleMA United States Harvard-MIT Health Sciences and Technology Massachusetts Institute of Technology 77 Massachusetts Ave CambridgeMA02139 United States

The Ceres Human Exploration and Transit Architecture (CHEATA) is a conceptual mission developed to enable human exploration of Ceres and other small bodies in the asteroid belt. These small bodies present tempting targets for future human exploration, providing insight into the evolution of our solar system, potentially containing environments of interest to astrobiologists, and acting as water- and mineral-rich stepping stones for outer solar system exploration. Minimizing radiation exposure and mission duration while maximizing surface science operations on the surface of Ceres was the critical driving requirement for this design reference mission. Key elements of the design include (1) a low gravity hopping vehicle using vacuum retro-propulsion and LOX/Methane propellant, taking advantage of the low gravity environment for regional exploration and surface operations on Ceres, (2) a bimodal nuclear thermal propulsion (NTP) system that utilizes liquid hydrogen and a reusable CERMET core, and (3) an active high-temperature superconducting magnet system, complemented by a passive high-density polyethylene system, to mitigate crew exposure to galactic cosmic radiation and solar energetic particle events. A transit habitat vehicle is assembled in cislunar space and used to ferry astronauts to Ceres orbit. The study also details breakdowns of the human countermeasures employed to address the effects of microgravity and isolation. The CHEATA mission concept was initially presented at the IEEE Aerospace Conference in 2022. The mission architecture has been updated to now include the design of additional spacecraft and habitation subsystems. These include the design of an Environmental Control and Life Support System, secondary propulsion for corrections, small maneuvers, and attitude control, but also more in-depth power and thermal management systems. The propellant storage was refined with the inclusion of zero boil-off technology for the Liquid Hydrogen tanks. A detail

关键词： Liquefied gases

来源：评论

学校读者我要写书评

暂无评论

Unveiling theory of mind in large language models: A parallel to single neurons in the human brain

arXiv

引用

arXiv 2023年

作者： Jamali, Mohsen Williams, Ziv M. Cai, Jing Department of Neurosurgery Massachusetts General Hospital Harvard Medical School BostonMA United States Harvard-MIT Division of Health Sciences and Technology BostonMA United States Harvard Medical School Program in Neuroscience BostonMA United States

With their recent development, large language models (LLMs) have been found to exhibit a certain level of Theory of Mind (ToM), a complex cognitive capacity that is related to our conscious mind and that allows us to infer another's beliefs and perspective. While human ToM capabilities are believed to derive from the neural activity of a broadly interconnected brain network, including that of dorsal medial prefrontal cortex (dmPFC) neurons, the precise processes underlying LLM's capacity for ToM or their similarities with that of humans remains largely unknown. In this study, we drew inspiration from the dmPFC neurons subserving human ToM and employed a similar methodology to examine whether LLMs exhibit comparable characteristics. Surprisingly, our analysis revealed a striking resemblance between the two, as hidden embeddings (artificial neurons) within LLMs started to exhibit significant responsiveness to either true- or false-belief trials, suggesting their ability to represent another's perspective. These artificial embedding responses were closely correlated with the LLMs' performance during the ToM tasks, a property that was dependent on the size of the models. Further, the other's beliefs could be accurately decoded using the entire embeddings, indicating the presence of the embeddings' ToM capability at the population level. Together, our findings revealed an emergent property of LLMs' embeddings that modified their activities in response to ToM features, offering initial evidence of a parallel between the artificial model and neurons in the human brain. © 2023, CC BY-NC-SA.

关键词： Neurons

来源：评论

学校读者我要写书评

暂无评论

Measurement of peripheral nerve magnetostimulation thresholds of a head solenoid coil between 200 Hz and 88.1 kHz

引用

IEEE Journal of Translational Engineering in health and Medicine 2025年

作者： Barksdale, Alex C. Ferris, Natalie G. Mattingly, Eli Sliwiak, Monika Guerin, Bastien Wald, Lawrence L. Davids, Mathias Klein, Valerie MIT Department of Electrical Engineering and Computer Science CambridgeMA United States Martinos Center for Biomedical Imaging CharlestownMA United States Harvard University Harvard Graduate Program in Biophysics CambridgeMA United States Harvard-MIT Division of Health Sciences and Technology BostonMA United States Harvard Medical School BostonMA United States

Objective: Magnetic fields switching at kilohertz frequencies induce electric fields in the body, which can cause peripheral nerve stimulation (PNS). Although magnetostimulation has been extensively studied below 10 kHz, the behavior of PNS at higher frequencies remains poorly understood. This study aims to investigate PNS thresholds at frequencies up to 88.1 kHz and to explore deviations from the widely accepted hyperbolic strength-duration curve (SDC). Methods and procedures: PNS thresholds were measured in the head of 8 human volunteers using a solenoidal coil at 16 distinct frequencies, ranging from 200 Hz to 88.1 kHz. A hyperbolic SDC was used as a reference to compare the frequency-dependent behavior of PNS thresholds. Results: Contrary to the predictions of the hyperbolic SDC, PNS thresholds did not decrease monotonically with frequency. Instead, thresholds reached a minimum near 25 kHz, after which they increased by an average of 39% from 25 kHz to 88.1 kHz across subjects. This pattern indicates a significant deviation from previously observed behavior at lower frequencies. Conclusion: Our results suggest that PNS thresholds exhibit a non-monotonic frequency dependence at higher frequencies, diverging from the traditional hyperbolic SDC. These findings offer critical data for refining neurodynamic models and provide insights for setting PNS safety limits in applications like MRI gradient coils and magnetic particle imaging (MPI). Further investigation is needed to understand the biological mechanisms driving these deviations beyond 25 kHz. Clinical impact: These findings call for further basic research into biological mechanisms underlying high frequency PNS threshold trends, and supports refinement of safety guidelines for MRI and MPI systems for clinical implementation. © 2013 IEEE.

关键词： Neuroimaging

来源：评论

学校读者我要写书评

暂无评论

Experience influences the refinement of feature selectivity in the mouse primary visual thalamus

引用

Neuron 2025年第9期113卷 1352-1362.e4页

作者： Sonoda, Takuma Stephany, Céleste-Élise Kelley, Kaleb Kang, Di Wu, Rui Uzgare, Meghna R. Fagiolini, Michela Greenberg, Michael E. Chen, Chinfei Department of Neurology F.M. Kirby Neurobiology Center Boston Children's Hospital Boston 02115 MA United States Department of Neurobiology Harvard Medical School Boston 02115 MA United States Harvard-MIT Health Sciences and Technology Program Harvard Medical School Boston 02115 MA United States

Neurons exhibit selectivity for specific features: a property essential for extracting and encoding relevant information in the environment. This feature selectivity is thought to be modifiable by experience at the level of the cortex. Here, we demonstrate that selective exposure to a feature during development can alter the population representation of that feature in the primary visual thalamus. This thalamic plasticity is not due to changes in corticothalamic inputs and is blocked in mutant mice that exhibit deficits in retinogeniculate refinement, suggesting that plasticity is a direct result of changes in feedforward connectivity. Notably, experience-dependent changes in thalamic feature selectivity also occur in adult animals, although these changes are transient, unlike in juvenile animals, where they are long lasting. These results reveal an unexpected degree of plasticity in the visual thalamus and show that salient environmental features can be encoded in thalamic circuits during a discrete developmental window. © 2025 Elsevier Inc.

关键词： circuit development dLGN experience-dependent plasticity feature selectivity retinogeniculate synaptic plasticity thalamus

来源：评论

学校读者我要写书评

暂无评论

Probabilistic Genotype-Phenotype Maps Reveal Mutational Robustness of RNA Folding, Spin Glasses, and Quantum Circuits

arXiv

引用

arXiv 2023年

作者： Sappington, Anna Mohanty, Vaibhav Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States Program for Health Sciences and Technology Harvard Medical School BostonMA02115 United States Massachusetts Institute of Technology CambridgeMA02139 United States Harvard/MIT MD-PhD Program Harvard Medical School BostonMA02115 United States Department of Chemistry and Chemical Biology Harvard University CambridgeMA02138 United States

Recent studies of genotype-phenotype (GP) maps have reported universally enhanced phenotypic robustness to genotype mutations, a feature essential to evolution. Virtually all of these studies make a simplifying assumption that each genotype—represented as a sequence—maps deterministically to a single phenotype, such as a discrete structure. Here, we introduce probabilistic genotype-phenotype (PrGP) maps, where each genotype maps to a vector of phenotype probabilities, as a more realistic and universal language for investigating robustness in a variety of physical, biological, and computational systems. We study three model systems to show that PrGP maps offer a generalized framework which can handle uncertainty emerging from various physical sources: (1) thermal fluctuation in RNA folding, (2) external field disorder in spin glass ground state finding, and (3) superposition and entanglement in quantum circuits, which are realized experimentally on IBM quantum computers. In all three cases, we observe a novel biphasic robustness scaling which is enhanced relative to random expectation for more frequent phenotypes and approaches random expectation for less frequent phenotypes. We derive an analytical theory for the behavior of PrGP robustness, and we demonstrate that the theory is highly predictive of empirical robustness. © 2023, CC BY.

关键词： Quantum computers

来源：评论

学校读者我要写书评

暂无评论

Randomizing the human genome by engineering recombination between repeat elements

引用

Science (New York, N.Y.) 2025年第6733期387卷 eado3979页

作者： Koeppel, Jonas Ferreira, Raphael Vanderstichele, Thomas Riedmayr, Lisa Maria Peets, Elin Madli Girling, Gareth Weller, Juliane Murat, Pierre Liberante, Fabio Giuseppe Ellis, Tom Church, George McDonald Parts, Leopold Hinxton United Kingdom Harvard Medical School Department of Genetics Boston MA United States Wyss Institute for Biologically Inspired Engineering Harvard University Boston MA United States Broad Institute of Massachusetts Institute of Technology and Harvard University Cambridge MA United States Department of Bioengineering Imperial College London London United Kingdom Harvard-MIT Program in Health Sciences and Technology Cambridge MA United States Harvard Medical School Boston MA United States

We lack tools to edit DNA sequences at scales necessary to study 99% of the human genome that is noncoding. To address this gap, we applied CRISPR prime editing to insert recombination handles into repetitive sequences, up to 1697 per cell line, which enables generating large-scale deletions, inversions, translocations, and circular DNA. Recombinase induction produced more than 100 stochastic megabase-sized rearrangements in each cell. We tracked these rearrangements over time to measure selection pressures, finding a preference for shorter variants that avoided essential genes. We characterized 29 clones with multiple rearrangements, finding an impact of deletions on expression of genes in the variant but not on nearby genes. This genome-scrambling strategy enables large deletions, sequence relocations, and the insertion of regulatory elements to explore genome dispensability and organization.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Metal-based porous hydrogels for highly conductive biomaterial scaffolds (vol 3, itad002, 2023)

引用

OXFORD OPEN MATERIALS SCIENCE 2023年第1期3卷 itad002页

作者： Tringides, Christina M. Boulingre, Marjolaine Mooney, David J. Program in Biophysics Harvard University Cambridge MA 02138 USA. Wyss Institute for Biologically Inspired Engineering Harvard University Cambridge MA 02115 USA. John A. Paulson School of Engineering and Applied Sciences Harvard University Cambridge MA 02138 USA. Harvard-MIT Division in Health Sciences and Technology Massachusetts Institute of Technology Cambridge MA 02142 USA. Department of Bioengineering Imperial College London London SW7 2BP United Kingdom.

Multielectrode arrays are fabricated from thin films of highly conductive and ductile metals which cannot mimic the natural environment of biological tissues. These properties limit the conformability of the electrode to the underlying target tissue, and present challenges in developing seamless interfaces. By introducing porous, hydrogel materials that are embedded with metal additives, highly conductive hydrogels can be formed. Tuning the hydrogel composition, % volume and aspect ratio of different additive(s), and the processing conditions of these composite materials can alter the mechanical and electrical properties. The resulting materials have a high surface area, and can be used as biomaterial scaffolds to support the growth of macrophages for 5 days. Further optimization can enable the use of the materials for the electrodes in implantable arrays, or as living electrode platforms to study and modulate various cellular cultures. These advancements would benefit both and applications of tissue engineering.

关键词： 3D biology biohybrid electronics biomaterials composites conductive scaffolds hydrogels tissue engineering

来源：评论

学校读者我要写书评

暂无评论

Joint cortical registration of geometry and function using semi-supervised learning

arXiv

引用

arXiv 2023年

作者： Li, Jian Tuckute, Greta Fedorenko, Evelina Edlow, Brian L. Fischl, Bruce Dalca, Adrian V. A. A. Martinos Center for Biomedical Imaging Department of Radiology Massachusetts General Hospital Harvard Medical School United States Center for Neurotechnology and Neurorecovery Department of Neurology Massachusetts General Hospital Harvard Medical School United States Department of Brain and Cognitive Sciences Massachusetts Institute of Technology United States McGovern Institute for Brain Research Massachusetts Institute of Technology United States Program in Speech Hearing Bioscience and Technology Harvard University United States Computer Science and Artificial Intelligence Laboratory Massachusetts Institute of Technology United States Harvard-MIT Program in Health Sciences and Technology United States

Brain surface-based image registration, an important component of brain image analysis, establishes spatial correspondence between cortical surfaces. Existing iterative and learning-based approaches focus on accurate registration of folding patterns of the cerebral cortex, and assume that geometry predicts function and thus functional areas will also be well aligned. However, structure/functional variability of anatomically corresponding areas across subjects has been widely reported. In this work, we introduce a learning-based cortical registration framework, JOSA, which jointly aligns folding patterns and functional maps while simultaneously learning an optimal atlas. We demonstrate that JOSA can substantially improve registration performance in both anatomical and functional domains over existing methods. By employing a semi-supervised training strategy, the proposed framework obviates the need for functional data during inference, enabling its use in broad neuroscientific domains where functional data may not be observed. The source code of JOSA will be released to the public at https://***. © 2023, CC BY.

关键词： Iterative methods

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：