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Functional brain imaging of gastrointestinal sensation in health and disease

World journal of Gastroenterology 2007年第25期13卷 3438-3445页

作者： Lukas Van Oudenhove steven j coen Qasim Aziz Department of Neurosciences Division of Psychiatry & Department of Pathophysiology Gastroenterology Section University Hospital Gasthuisberg University of Leuven Belgium Centre for Neuroimaging Sciences Institute of Psychiatry London United Kingdom Division of Neuroscience & Medicine Department of GI Sciences Hope Hospital University of Manchester United Kingdom

It has since long been known, from everyday experience as well as from animal and human studies, that psychological processes-both affective and cognitive- exert an influence on gastrointestinal sensorimotor function. More specifically, a link between psychological factors and visceral hypersensitivity has been suggested, mainly based on research in functional gastrointestinal disorder patients. However, until recently, the exact nature of this putative relationship remained unclear, mainly due to a lack of non-invasive methods to study the （neurobiological） mechanisms underlying this relationship in non-sleeping humans. As functional brain imaging, introduced in visceral sensory neuroscience some 10 years ago, does provide a method for in vivo study of brain-gut interactions, insight into the neurobiological mechanisms underlying visceral sensation in general and the influence of psychological factors more particularly, has rapidly grown. In this article, an overview of brain imaging evidence on gastrointestinal sensation will be given, with special emphasis on the brain mechanisms underlying the interaction between affective ＆ cognitive processes and visceral sensation. First, the reciprocal neural pathways between the brain and the gut （brain- gut axis） will be briefly outlined, including brain imaging evidence in healthy volunteers. Second, functional brain imaging studies assessing the influence of psychological factors on brain processing of visceral sensation in healthy humans will be discussed in more detail. Finally, brain imaging work investigating differences in brain responses to visceral distension between healthy volunteers and functional gastrointestinal disorder patients will be highlighted.

关键词： Functional brain imaging Functionalgastro-intestinal disorders Visceral hypersensitivity Gastrointestinal sensation Psychological factors

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亚洲高山流域千年尺度地表剥蚀的制约因素

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中国科学:地球科学 2025年第1期 75-94页

作者：杨业 steven A.BINNIE 徐胜刘丛强 Tibor j.DUNAI 天津大学地球系统科学学院表层地球系统科学研究院 Institute of Geology and Mineralogy University of Cologne

本研究利用前人1233个亚洲高山流域沉积物宇宙成因核素10Be数据统一计算了地表剥蚀速率,以约束构造、气候和地形如何影响和控制地表剥蚀过程.基于高程数据逐个像元的核素产率,使用蒙特卡洛模拟方法重新计算了10Be流域剥蚀速率.剥蚀速率... 详细信息

本研究利用前人1233个亚洲高山流域沉积物宇宙成因核素10Be数据统一计算了地表剥蚀速率,以约束构造、气候和地形如何影响和控制地表剥蚀过程.基于高程数据逐个像元的核素产率,使用蒙特卡洛模拟方法重新计算了10Be流域剥蚀速率.剥蚀速率变化范围从（7.4±0.7）mm ka-1（1σ;青藏高原内部）到（9,646744+777）mm ka-1（1σ;青藏高原南部）跨四个数量级,中位数为186mm ka-1.逐个像元计算的核素产率与传统模型使用质心坐标和平均高程计算的核素产率相比,后者96.6%核素产率被低估,其中高程差越大越被低估.两种方法计算的产率偏差可达40%,究其原因可能是流域高程分布不均和核素产率随海拔和纬度呈非线性变化.通过量化地表剥蚀速率与构造、气候、地形和岩性之间的相关性将有助于推演未知流域的剥蚀速率.从局部小尺度分析,亚热带台湾岛地区剥蚀速率可能主要受降水和新构造驱动的山体滑坡影响,而降水变化范围较窄的青藏高原东部的剥蚀速率主要受控于地形;冰川覆盖的高原地区剥蚀速率受冰川作用影响,如帕米尔、青藏高原内部和南部地区;青藏高原内部剥蚀速率较低是因为较低的降水和较高的侵蚀基准面,从而限制了河流的下切和地表起伏度演化.与局部小尺度强调单一主控因素不同,本研究对亚洲高山流域宏观大尺度进行量化分析发现:（1）地形指标（包括坡度、地形起伏度和河道陡峭指数）与剥蚀速率在千年尺度呈现一致的幂函数关系,而非简单线性;（2）剥蚀速率与气候（包括与海拔相关的降水、温度和植被覆盖度）和新构造活动（地震核密度分布）呈近似幂函数关系,为次要控制因素;（3）岩性与剥蚀速率没有明显的相关性,可能受限于流域复杂的岩性混合和低分辨率的可侵蚀指数数据.

关键词： 10Be剥蚀速率气候变化构造抬升地形梯度亚洲高山流域

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Constraints on what controls millennial-scale basin-wide denudation across mountain belts, Asia

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Science China Earth Sciences 2025年第1期 74-93页

作者： Ye YANG steven A.BINNIE Sheng XU Cong-Qiang LIU Tibor j.DUNAI Institute of Surface-Earth System Science School of Earth System Science Tianjin University Institute of Geology and Mineralogy University of Cologne

The terrestrial cosmogenic nuclide dataset consisting of 123310Be measurements of fluvial sediment samples across the Asian mountain belts is used to constrain the influence of climate,tectonics and topography on Earth-surface denudation processes.10Be-derived basin-wide denudation rates were recalculated using a Monte Carlo simulation approach that relied on pixel-by-pixel production *** rates derived span four orders of magnitude,from 7.4±0.7 mm kyr-1（1σ;Central Tibetan Plateau） to 9,646744+777mm kyr-1（1σ;Southern Tibetan Plateau）,with a median of 186 mm *** our results with the traditional basin-wide production rate scaling model using a centroid coordinate and mean elevation,suggests that 96.6%of production rates will be underestimated using the latter method,especially for basins with a large *** bias between both methods reaches as large as 40%,caused by basin hypsometry and the nonlinear scaling of production rate with elevation and *** of the correlations between uniformly recalculated denudation rates and tectonics,climate,topography and rock lithology will facilitate the extrapolation of denudation rates in unknown basins using available *** the perspective of local scales,precipitation coupled with neotectonics-driven landslides is likely the most influential factor in subtropical Taiwan Island,while topography primarily constrains surface denudation rates in the eastern Tibetan Plateau within a narrow range of *** highland regions with glacier coverage,such as the Pamir,central and southern Tibetan Plateau high denudation rates are affected by glaciation,whereas lower precipitation and high erosion base level may limit river incision and evolving relief in the Central Tibetan *** contrast to local-scale findings highlighting a dominant factor constraining denudation rate,our large-scale quantitative analyses across the Asian mountain belts finds that （1） topographic metrics including

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Analysis of smart contracts balances

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Blockchain(Research and Applications) 2021年第3期2卷 46-67页

作者： Cosimo Laneve Claudio Sacerdoti coen Department of Computer Science and Engineering University of BolognaINRIA FocusBologna40126Italy

We define a technique for analyzing updates of smart contracts balances due to transfers of digital *** analysis addresses a lightweight smart contract language and consists of a two-step ***,we define the input-output behaviors of smart contract functions by means of a simple functional language with static *** we associate the terms of this intermediate language with cost equations that compute the loss or gain of digital *** resulting equations can be fed to an off-the-shelf cost analyzer to provide upper bounds to the loss or *** analysis has been prototyped and we report its assessments and discuss extensions with additional features.

关键词： Smart contracts Blockchain Static analysis Cost analysis Cryptocurrency Movements

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VARIABLE STEP-SIZE IMPLICIT-EXPLICIT LINEAR MULTISTEP METHODS FOR TIME-DEPENDENT PARTIAL DIFFERENTIAL EQUATIONS

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journal of Computational Mathematics 2008年第6期26卷 838-855页

作者： DongWang steven j. Ruuth Department of Civil and Environmental Engineering University of Illinois at Urbana-Champaign B231 Newmark Civil Engineering Laboratory Urbana IL 61801 USA Department of Mathematics Simon Fraser University Burnaby BC Canada V5A 1S6

Implicit-explicit （IMEX） linear multistep methods are popular techniques for solving partial differential equations （PDEs） with terms of different types. While fixed timestep versions of such schemes have been developed and studied, implicit-explicit schemes also naturally arise in general situations where the temporal smoothness of the solution changes. In this paper we consider easily implementable variable step-size implicit-explicit （VSIMEX） linear multistep methods for time-dependent PDEs. Families of order-p, pstep VSIMEX schemes are constructed and analyzed, where p ranges from 1 to 4. The corresponding schemes are simple to implement and have the property that they reduce to the classical IMEX schemes whenever constant time step-sizes are imposed. The methods are validated on the Burgers＇ equation. These results demonstrate that by varying the time step-size, VSIMEX methods can outperform their fixed time step counterparts while still maintaining good numerical behavior.

关键词： Implicit-explicit (IMEX) linear multistep methods Variable step-size Zero-stability Burgers' equation.

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Mitogen-activated protein kinases mediate the oxidative burst and saponin synthesis induced by chitosan in cell cultures of Panax ginseng

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Science China(Life Sciences) 2004年第4期47卷 303-312页

作者： steven j. NEILL Centre for Research in Plant Science University of the West of England Bristol Coldharbour Lane Bristol BS16 1QY United Kingdom

Chitosan (CHN) specially induced the activities of 39 kD and 42 kD protein kinases in ginseng cells, which could be suppressed by an inhibitor of mitogen-activated protein kinase (MAPK) pathway, PD98059. The immunoprecipitation (IP) using MAPK antibody or kinase assay in vitro also showed that CHN-induced 42 kD and 39 kD protein kinases belonged to the MAPK family. PD98059 suppressed CHN-induced transcriptions of ginseng squalene synthase and ginseng squalene epoxidase genes (gss and gse), CHN-induced accumulation of β-Amyrin synthase (β-AS) and synthesis of saponin. These results showed that CHN-induced activities of MAPKs were necessary for the CHN-induced saponin synthesis. EGTA and LaCl3 suppressed CHN-induced 39 kD and 42 kD MAPK activities. Ruthenium red (RR) could suppress CHN-induced 39 kD activity. All of them suppressed CHN-induced saponin synthesis. These results indicated that CHN-induced increment of cytosolic calcium was necessary for CHN-induced saponin synthesis. PD98059 also suppressed CHN-induced oxidative burst (including the increment of activity of plasma membrane NADPH oxidase and production of H2O2), but diphenylene iodonium (DPI), dimethylthiourea (DMTU) and 2,5-dihydroxycinnamic acid methyl ester (DHC) could not suppress CHN-induced MAPK activities, which indicated that MAPK was possibly function upstream of CHN-induced oxidative burst. Keywords mitogen-activated protein kinase - chitosan - saponin

关键词： mitogen-activated protein kinase,chitosan,saponin.

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Transport model for shale gas well leakage through the surrounding fractured zones of a longwall mine

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International journal of Mining Science and Technology 2020年第5期30卷 635-641页

作者： Kayode M.Ajayi steven j.Schatzel Centers for Disease Control and Prevention National Institute for Occupational Safety and HealthPittsburghPA 15236USA

The environmental risks associated with casing deformation in unconventional(shale)gas wells positioned in abutment pillars of longwall mines is a concern to many in the mining and gas well *** the recent interest in shale exploration and the proximity to longwall mining in Southwestern Pennsylvania,the risk to mine workers could be catastrophic as fractures in surrounding strata create pathways for transport of leaked ***,this research by the National Institute for Occupational Safety and Health(NIOSH)presents an analytical model of the gas transport through fractures in a low permeable *** derived equations are used to conduct parametric studies of specific transport conditions to understand the influence of stratum geology,fracture lengths,and the leaked gas properties on subsurface *** results indicated that the prediction that the subsurface gas flux decreases with an increase in fracture length is specifically for a non-gassy *** sub-transport trend could be significantly impacted by the stratum gas generation rate within specific fracture lengths,which emphasized the importance of the stratum *** findings provide new insights for improved understanding of subsurface gas transport to ensure mine safety.

关键词： Subsurface gas transport Longwall mining Shale gas well Analytical modeling Environmental risk Shale gas casing failure

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Switchable Rashba anisotropy in layered hybrid organic-inorganic perovskite by hybrid improper ferroelectricity

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npj Computational Materials 2020年第1期6卷 147-154页

作者： Fei Wang Heng Gao coen de Graaf josep M.Poblet Branton j.Campbell Alessandro Stroppa Departament de Química Física i Inorganica Universitat Rovira i Virgilic/Marcel·líDomingo 1Tarragona 43007Spain Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory DongguanGuangdong 523808China ICREA Pg.Lluis Companys 23Barcelona 08010Spain Department of Physics&Astronomy Brigham Young UniversityProvoUT 84602USA CNR-SPIN c/o Department of Physical and Chemical Sciences University of L’AquilaVia VetoioI-67100 CoppitoL’AquilaItaly

Hybrid organic–inorganic perovskites(HOIPs)are introducing exotic directions in the photovoltaic materials *** coexistence of inversion symmetry breaking and spin–orbit interactions play a key role in their optoelectronic *** perform a detailed study on a recently synthesized ferroelectric layered HOIP,(AMP)PbI_(4)(AMP=4-aminomethyl-piperidinium).The calculated polarization and Rashba parameters are in excellent agreement with experimental values.

关键词： properties ferroelectric perovskite

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Compressive deformation of ultralong amyloid fibrils

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Acta Mechanica Sinica 2010年第6期26卷 977-986页

作者： Raffaella Paparcone steven Cranford Markus j.Buehler Laboratory for Atomistic and Molecular Mechanics

Involved in various neurodegenerative diseases, amyloid fibrils and plaques feature a hierarchical structure, ranging from the atomistic to the micrometer *** the atomistic level,a dense and organized hydrogen bond network is resembled in a beta-sheet rich secondary structure, which drives a remarkable stiffness in the range of 10-20GPa,larger than many other biological nanofibrils, a result confirmed by both experiment and ***, the understanding of how these exceptional mechanical properties transfer from the atomistic to the nanoscale remains *** we report a multiscale analysis that, from the atomistic-level structure of a single fibril,extends to the mesoscale level,reaching size scales of hundreds of *** use parameters directly derived from full atomistic simulations of Aβ（1-40） amyloid fibrils to parameterize a mesoscopic coarse-grained model,which is used to reproduce the elastic properties of amyloid *** then apply our mesoscopic model in an analysis of the buckling behavior of amyloid fibrils with different lengths and report a comparison with predictions from continuum beam theory. An important implication of our results is a severe reduction of the effective modulus due to buckling,an effect that could be important to interpret experimental results of ultralong amyloid *** model represents a powerful tool to mechanically characterize molecular structures on the order of hundreds of nanometers to micrometers on the basis of the underlying atomistic *** work provides insight into structural and mechanical properties of amyloid fibrils and may enable further analysis of larger-scale assemblies such as amyloidogenic bundles or plaques as found in disease states.

关键词： Amyloid Coarse-grain Molecular simulation Nanomechanics Materiomics

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Reprogramming cholesterol metabolism in macrophages and its role in host defense against cholesterol-dependent cytolysins

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Cellular & Molecular Immunology 2022年第3期19卷 327-336页

作者： Min-Sub Lee steven j.Bensinger Department of Molecular and Medical Pharmacology University of CaliforniaLos AngelesCA90095USA Department of Microbiology Immunology and Molecular GeneticsUniversity of CaliforniaLos AngelesCA90095USA

Cholesterol is a critical lipid for all mammalian cells,ensuring proper membrane integrity,fluidity,and biochemical *** evidence indicates that macrophages rapidly and profoundly reprogram their cholesterol metabolism in response to activation signals to support host defense ***,our understanding of the molecular details underlying how and why cholesterol homeostasis is specifically reshaped during immune responses remains less well *** review discusses our current knowledge of cellular cholesterol homeostatic machinery and introduces emerging concepts regarding how plasma membrane cholesterol is partitioned into distinct *** then discuss how proinflammatory signals can markedly reshape the cholesterol metabolism of macrophages,with a focus on the differences between MyD88-dependent pattern recognition receptors and the interferon signaling *** also discuss recent work investigating the capacity of these proinflammatory signals to selectively reshape plasma membrane cholesterol *** examine how these changes in plasma membrane cholesterol metabolism influence sensitivity to a set of microbial pore-forming toxins known as cholesterol-dependent cytolysins that specifically target cholesterol for their effector *** also discuss whether lipid metabolic reprogramming can be leveraged for therapy to mitigate tissue damage mediated by cholesterol-dependent cytolysins in necrotizing fasciitis and other related *** expect that advancing our understanding of the crosstalk between metabolism and innate immunity will help explain how inflammation underlies metabolic diseases and highlight pathways that could be targeted to normalize metabolic homeostasis in disease states.

关键词： Cholesterol Macrophages Innate Immunity Metabolism

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