Cognitive impairment is a common clinical manifestation of multiple sclerosis,but its pathophysiology is not completely understood.White and grey matter injury together with synaptic dysfunction do play a role.The mea...Cognitive impairment is a common clinical manifestation of multiple sclerosis,but its pathophysiology is not completely understood.White and grey matter injury together with synaptic dysfunction do play a role.The measurement of biomarkers in the cerebrospinal fluid and the study of their association with cognitive impairment may provide interesting in vivo evidence of the biological mechanisms underlying multiple sclerosis-related cognitive impairment.So far,only a few studies on this topic have been published,giving interesting results that deserve further investigation.Cerebrospinal fluid biomarkers of different pathophysiological mechanisms seem to reflect different neuropsychological patterns of cognitive deficits in multiple sclerosis.The aim of this review is to discuss the studies that have correlated cerebrospinal fluid markers of immune,glial and neuronal pathology with cognitive impairment in multiple sclerosis.Although preliminary,these findings suggest that cerebrospinal fluid biomarkers show some correlation with cognitive performance in multiple sclerosis,thus providing interesting insights into the mechanisms underlying the involvement of specific cognitive domains.展开更多
Transthyretin (TTR), a carrier protein present in the liver and choroid plexus of the brain, has been shown to be responsible for binding thyroid hormone thyroxin (T4) and retinol in plasma and cerebrospinal fluid (CS...Transthyretin (TTR), a carrier protein present in the liver and choroid plexus of the brain, has been shown to be responsible for binding thyroid hormone thyroxin (T4) and retinol in plasma and cerebrospinal fluid (CSF). TTR aids in sequestering of beta-amyloid peptides Aβ deposition, and protects the brain from trauma, ischemic stroke and Alzheimer disease (AD). Accordingly, hippocampal gene expression of TTR plays a significant role in learning and memory as well as in simulation of spatial memory tasks. TTR via interacting with transcription factor CREB regulates this process and decreased expression leads to memory deficits. By different signaling pathways, like MAPK, AKT, and ERK via Src, TTR provides tropical support through megalin receptor by promoting neurite outgrowth and protecting the neurons from traumatic brain injury. TTR is also responsible for the transient rise in intracellular Ca2+ via NMDA receptor, playing a dominant role under excitotoxic conditions. In this review, we tried to shed light on how TTR is involved in maintaining normal cognitive processes, its role in learning and memory, under memory deficit conditions;by which mechanisms it promotes neurite outgrowth;and how it protects the brain from Alzheimer disease (AD).展开更多
The concept of aqueous computing is presented here, first in full generality,and afterward, using an implementation in a specific enzymatic technology. Aqueous computing arosein the context of biomolecular (DNA) compu...The concept of aqueous computing is presented here, first in full generality,and afterward, using an implementation in a specific enzymatic technology. Aqueous computing arosein the context of biomolecular (DNA) computing, but the concept is independent of the specifics ofits biochemical origin. Alternate technologies for realizing aqueous computing are being consideredfor future implementation. A solution of an instance of the Boolean satisfiability problem, (SAT),is reported here that provides a new example of an aqueous computation that has been carried outsuccessfully. This small instance of the SAT problem is sufficiently complex to allow our currentenzymatic technology to be illustrated in detail. The reader is invited to participate in the richinterdisciplinary activity required by wet lab computing. A project is suggested to the reader fordetermining the three-colorings of a graph. The basic operations required for this project areexhibited in the solution of the SAT example reported here.展开更多
Red blood cells can recover their resting shape after having been deformed by shear flow.Their rims are always formed by the same part of the membranes,and the cells are said to have shapememory.Modeled as two-dimensi...Red blood cells can recover their resting shape after having been deformed by shear flow.Their rims are always formed by the same part of the membranes,and the cells are said to have shapememory.Modeled as two-dimensional elastic capsules,their recoverymotion and shapememory is studied,mainly focused on the effect of the spontaneous shape.The fluid-structure interaction ismodeled using immersed boundary method.Based on the simulations,the resting shapes of capsules are obtained and the area ratio of spontaneous shape is found to play an important role.After remove of shear flow,all capsules can recover their resting shapes,while only capsules with noncircular spontaneous shapes present shape memory.As the spontaneous shape approaches a circle but still noncircular,the capsule spends more time on recovery process.We consider how these capsules deform depending on the membrane bending energy,and find that the relaxation speed is positive correlated to the range of values of dimensionless bending energy.These results may help to identify different spontaneous shapes for capsules especially RBCs through future experiments.展开更多
Many fishes use undulatory fin to propel themselves in the underwater environment. These locomotor mechanisms have a popular interest to many researchers. In the present study, we perform a three-dimensional unsteady ...Many fishes use undulatory fin to propel themselves in the underwater environment. These locomotor mechanisms have a popular interest to many researchers. In the present study, we perform a three-dimensional unsteady computation of an undulatory mechanical fin that is driven by Shape Memory Alloy （SMA）. The objective of the computation is to investigate the fluid dynamics of force production associated with the undulatory mechanical fin. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing is used to compute the unsteady flow around the fin through five complete cycles. The pressure distribution on fin surface is computed and integrated to provide fin forces which are decomposed into lift and thrust. The velocity field is also computed throughout the swimming cycle. Finally, a comparison is conducted to reveal the dynamics of force generation according to the kinematic parameters of the undulatory fin （amplitude, frequency and wavelength）.展开更多
文摘Cognitive impairment is a common clinical manifestation of multiple sclerosis,but its pathophysiology is not completely understood.White and grey matter injury together with synaptic dysfunction do play a role.The measurement of biomarkers in the cerebrospinal fluid and the study of their association with cognitive impairment may provide interesting in vivo evidence of the biological mechanisms underlying multiple sclerosis-related cognitive impairment.So far,only a few studies on this topic have been published,giving interesting results that deserve further investigation.Cerebrospinal fluid biomarkers of different pathophysiological mechanisms seem to reflect different neuropsychological patterns of cognitive deficits in multiple sclerosis.The aim of this review is to discuss the studies that have correlated cerebrospinal fluid markers of immune,glial and neuronal pathology with cognitive impairment in multiple sclerosis.Although preliminary,these findings suggest that cerebrospinal fluid biomarkers show some correlation with cognitive performance in multiple sclerosis,thus providing interesting insights into the mechanisms underlying the involvement of specific cognitive domains.
文摘Transthyretin (TTR), a carrier protein present in the liver and choroid plexus of the brain, has been shown to be responsible for binding thyroid hormone thyroxin (T4) and retinol in plasma and cerebrospinal fluid (CSF). TTR aids in sequestering of beta-amyloid peptides Aβ deposition, and protects the brain from trauma, ischemic stroke and Alzheimer disease (AD). Accordingly, hippocampal gene expression of TTR plays a significant role in learning and memory as well as in simulation of spatial memory tasks. TTR via interacting with transcription factor CREB regulates this process and decreased expression leads to memory deficits. By different signaling pathways, like MAPK, AKT, and ERK via Src, TTR provides tropical support through megalin receptor by promoting neurite outgrowth and protecting the neurons from traumatic brain injury. TTR is also responsible for the transient rise in intracellular Ca2+ via NMDA receptor, playing a dominant role under excitotoxic conditions. In this review, we tried to shed light on how TTR is involved in maintaining normal cognitive processes, its role in learning and memory, under memory deficit conditions;by which mechanisms it promotes neurite outgrowth;and how it protects the brain from Alzheimer disease (AD).
基金国家自然科学基金，the Leiden Center for Natural Computing, and the Leiden Institute for Advanced Computer Science
文摘The concept of aqueous computing is presented here, first in full generality,and afterward, using an implementation in a specific enzymatic technology. Aqueous computing arosein the context of biomolecular (DNA) computing, but the concept is independent of the specifics ofits biochemical origin. Alternate technologies for realizing aqueous computing are being consideredfor future implementation. A solution of an instance of the Boolean satisfiability problem, (SAT),is reported here that provides a new example of an aqueous computation that has been carried outsuccessfully. This small instance of the SAT problem is sufficiently complex to allow our currentenzymatic technology to be illustrated in detail. The reader is invited to participate in the richinterdisciplinary activity required by wet lab computing. A project is suggested to the reader fordetermining the three-colorings of a graph. The basic operations required for this project areexhibited in the solution of the SAT example reported here.
基金We acknowledge the support from the National Natural Science Foundation of China(No.51505455)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.51521064)Applied Research Project of Public Welfare Technology of Zhejiang Province under Grant(No.2015C31109).We would like to thank Dr.Pengfei Wang for his helpful discussions during this work.
文摘Red blood cells can recover their resting shape after having been deformed by shear flow.Their rims are always formed by the same part of the membranes,and the cells are said to have shapememory.Modeled as two-dimensional elastic capsules,their recoverymotion and shapememory is studied,mainly focused on the effect of the spontaneous shape.The fluid-structure interaction ismodeled using immersed boundary method.Based on the simulations,the resting shapes of capsules are obtained and the area ratio of spontaneous shape is found to play an important role.After remove of shear flow,all capsules can recover their resting shapes,while only capsules with noncircular spontaneous shapes present shape memory.As the spontaneous shape approaches a circle but still noncircular,the capsule spends more time on recovery process.We consider how these capsules deform depending on the membrane bending energy,and find that the relaxation speed is positive correlated to the range of values of dimensionless bending energy.These results may help to identify different spontaneous shapes for capsules especially RBCs through future experiments.
文摘Many fishes use undulatory fin to propel themselves in the underwater environment. These locomotor mechanisms have a popular interest to many researchers. In the present study, we perform a three-dimensional unsteady computation of an undulatory mechanical fin that is driven by Shape Memory Alloy （SMA）. The objective of the computation is to investigate the fluid dynamics of force production associated with the undulatory mechanical fin. An unstructured, grid-based, unsteady Navier-Stokes solver with automatic adaptive remeshing is used to compute the unsteady flow around the fin through five complete cycles. The pressure distribution on fin surface is computed and integrated to provide fin forces which are decomposed into lift and thrust. The velocity field is also computed throughout the swimming cycle. Finally, a comparison is conducted to reveal the dynamics of force generation according to the kinematic parameters of the undulatory fin （amplitude, frequency and wavelength）.
