In order to improve the reliability of an electronic or a computer system, redundant components always need to be added as part of the system. When an active component falls, a standby component will be activated to g...In order to improve the reliability of an electronic or a computer system, redundant components always need to be added as part of the system. When an active component falls, a standby component will be activated to guarantee the system in operation continuously. The standby component and the switching device have been usually assumed to be continuously functional duriv,g the setup of the reliability model. In fact, it is these two asstuxtptions that induce deviations during modeling and introduce variances for the system reliability design. Through modeling and optiming the dependability of the synchronous clock system that decomposed from a multi-node system, a new reliability model which takes these two elements into consideration has been developed. Simulation results demonstrate that the upgraded reliability model is closer Io the actual dependability of the real system. The capability of the system reliability design is also improved as a result.展开更多
It is hard for the existing methods to obtain the expression of the system reliability for most of the practical complex systems with a large number of components and possible stales. A new regression algorithm based ...It is hard for the existing methods to obtain the expression of the system reliability for most of the practical complex systems with a large number of components and possible stales. A new regression algorithm based on the lower and upper bounds is presented in this paper, which can obtain the system reliability analytically without concerning the structure of the complex system. The method has been applied to a real system and the reliability results are compared with those acquired by the classical method and the parametric method. The effectiveness and accuracy of the proposed method have been testified.展开更多
Dysfunction of inhibitory synaptic transmission can destroy the balance between excitatory and inhibitory synaptic inputs in neurons,thereby inducing epileptic activity.The aim of the paper is to investigate the effec...Dysfunction of inhibitory synaptic transmission can destroy the balance between excitatory and inhibitory synaptic inputs in neurons,thereby inducing epileptic activity.The aim of the paper is to investigate the effects of successive excitatory inputs on the epileptic activity induced in the absence of inhibitions.Paired-pulse orthodromic and antidromic stimulations were used to test the changes in the evoked responses in the hippocampus.Picrotoxin(PTX),γ-aminobutyric acid(GABA) type A(GABA A) receptor antagonist,was added to block the inhibitory synaptic transmission and to establish the epileptic model.Extracellular evoked population spike(PS) was recorded in the CA1 region of the hippocampus.The results showed that the application of PTX induced a biphasic change in the paired-pulse ratio of PS amplitude.A short latency increase of the second PS(PS2) was later followed by a reappearance of PS2 depression.This type of depression was observed in both orthodromic and antidromic paired-pulse responses,whereas the GABAergic PS2 depression [called paired-pulse depression(PPD)] during baseline recordings only appeared in orthodromic-evoked responses.In addition,the depression duration at approximately 100 ms was consistent with a relative silent period observed within spontaneous burst discharges induced by prolonged application of PTX.In conclusion,the neurons may ignore the excitatory inputs and intrinsically generate bursts during epileptic activity.The depolarization block could be the mechanisms underlying the PPD in the absence of GABA A inhibitions.The distinct neuronal responses to stimulations during different epileptic stages may implicate the different antiepileptic effects of electrical stimulation.展开更多
Ferroptosis, as a new type of cell death caused by lipid peroxidation, has attracted much attention since it was first identified in 2012. A lot of progress has been made in unraveling its mechanisms and therapeutic p...Ferroptosis, as a new type of cell death caused by lipid peroxidation, has attracted much attention since it was first identified in 2012. A lot of progress has been made in unraveling its mechanisms and therapeutic potential as a target for cancer therapy. Hitherto, there are mainly two strategies widely adopted for designing ferroptosis-inducing agents, which include increasing the intracellular reactive oxygen species(ROS) level by Fenton reaction, and inactivating the glutathione peroxidase 4(GPX4). In this mini-review,we summarize the recent advances in ferroptosis-based anticancer treatments with a highlight on nanomaterials, and discuss the current challenges faced by those agents from the perspective of in vivo applications. Moreover, by generalizing ferroptosis induced by excess iron ions to cell death caused by the polyvalent metal-mediated oxidative burden, we introduce a new paradigm of cancer treatment by exploiting various polyvalent metals to disrupt the vulnerable redox balance in cancer cells, which may greatly diversify our arsenal to combat cancer.展开更多
The ability to control cell patterning on artificial substrates with various physicochemical properties is of essence for important implications in cytology and biomedical fields. Despite extensive progress, the abili...The ability to control cell patterning on artificial substrates with various physicochemical properties is of essence for important implications in cytology and biomedical fields. Despite extensive progress, the ability to control the cell-surface interaction is complicated by the complexity in the physiochemical features of bioactive surfaces. In particular, the manifesta- tion of special wettability rendered by the combination of surface roughness and surface chemistry further enriches the cell-surface interaction. Herein we investigated the cell adhesion behaviors of Circulating Tumor Cells (CTCs) on topog- raphically patterned but chemically homogeneous surfaces. Harnessing the distinctive cell adhesion on surfaces with different topography, we further explored the feasibility of controlled cell patterning using periodic lattices of alternative topographies. We envision that our method provides a designer's toolbox to manage the extracellular environment.展开更多
In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding base...In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding based on the analysis of simulation and modeling have given rise to electrophysiological models of periglomerular cells,which have an important role in the understanding of the biology of these cells.In this review we provide a brief introduction to the anatomy of the olfactory system and the cell types in the olfactory bulb.We elaborate on the latest progress in the study of the heterogeneity of periglomerular cells based on different classification criteria,such as molecular markers,structure,ion channels and action potentials.Then,we discuss the several existing electrophysiological models of periglomerular cells,and we highlight the problems and defects of these models.Finally,considering our present work,we propose a future direction for electrophysiological investigations of periglomerular cells and for the modeling of periglomerular cells and olfactory information encoding.展开更多
As microsatellite technology develops,precise inter-satellite measurement shows its significance in distributed satellite systems.In this Letter,a novel technique is proposed for measuring the inter-satellite distance...As microsatellite technology develops,precise inter-satellite measurement shows its significance in distributed satellite systems.In this Letter,a novel technique is proposed for measuring the inter-satellite distance,which adopts optoelectronic resonance and has a function of self-referencing.Resonance cavities have a high spectral purity and a high oscillation frequency.By utilizing the accumulative amplification principle to convert the measurement of distance to that of the frequency,high accuracy is achieved.In the experiment,this measuring scheme has a large measuring range between 1 and 6 km(can be potentially larger),and the accuracy is better than 1.5 urn.The relative accuracy reaches the level of 10^-10.展开更多
文摘In order to improve the reliability of an electronic or a computer system, redundant components always need to be added as part of the system. When an active component falls, a standby component will be activated to guarantee the system in operation continuously. The standby component and the switching device have been usually assumed to be continuously functional duriv,g the setup of the reliability model. In fact, it is these two asstuxtptions that induce deviations during modeling and introduce variances for the system reliability design. Through modeling and optiming the dependability of the synchronous clock system that decomposed from a multi-node system, a new reliability model which takes these two elements into consideration has been developed. Simulation results demonstrate that the upgraded reliability model is closer Io the actual dependability of the real system. The capability of the system reliability design is also improved as a result.
基金National Natural Science Foundation of China(No.40927001)
文摘It is hard for the existing methods to obtain the expression of the system reliability for most of the practical complex systems with a large number of components and possible stales. A new regression algorithm based on the lower and upper bounds is presented in this paper, which can obtain the system reliability analytically without concerning the structure of the complex system. The method has been applied to a real system and the reliability results are compared with those acquired by the classical method and the parametric method. The effectiveness and accuracy of the proposed method have been testified.
基金Project (Nos. 30770548 and 30970753) supported by the National Natural Science Foundation of China
文摘Dysfunction of inhibitory synaptic transmission can destroy the balance between excitatory and inhibitory synaptic inputs in neurons,thereby inducing epileptic activity.The aim of the paper is to investigate the effects of successive excitatory inputs on the epileptic activity induced in the absence of inhibitions.Paired-pulse orthodromic and antidromic stimulations were used to test the changes in the evoked responses in the hippocampus.Picrotoxin(PTX),γ-aminobutyric acid(GABA) type A(GABA A) receptor antagonist,was added to block the inhibitory synaptic transmission and to establish the epileptic model.Extracellular evoked population spike(PS) was recorded in the CA1 region of the hippocampus.The results showed that the application of PTX induced a biphasic change in the paired-pulse ratio of PS amplitude.A short latency increase of the second PS(PS2) was later followed by a reappearance of PS2 depression.This type of depression was observed in both orthodromic and antidromic paired-pulse responses,whereas the GABAergic PS2 depression [called paired-pulse depression(PPD)] during baseline recordings only appeared in orthodromic-evoked responses.In addition,the depression duration at approximately 100 ms was consistent with a relative silent period observed within spontaneous burst discharges induced by prolonged application of PTX.In conclusion,the neurons may ignore the excitatory inputs and intrinsically generate bursts during epileptic activity.The depolarization block could be the mechanisms underlying the PPD in the absence of GABA A inhibitions.The distinct neuronal responses to stimulations during different epileptic stages may implicate the different antiepileptic effects of electrical stimulation.
基金supported by the National Key Research and Development Program of China (No. 2016YFA0203600)the National Natural Science Foundation of China (Nos. 31822019, 91859116 and 51703195)+1 种基金the Fundamental Research Funds for the Central Universities (No. 2018QNA7020)the One Belt and One Road International Cooperation Project from Key Research and Development Program of Zhejiang Province (No. 2019C04024)
文摘Ferroptosis, as a new type of cell death caused by lipid peroxidation, has attracted much attention since it was first identified in 2012. A lot of progress has been made in unraveling its mechanisms and therapeutic potential as a target for cancer therapy. Hitherto, there are mainly two strategies widely adopted for designing ferroptosis-inducing agents, which include increasing the intracellular reactive oxygen species(ROS) level by Fenton reaction, and inactivating the glutathione peroxidase 4(GPX4). In this mini-review,we summarize the recent advances in ferroptosis-based anticancer treatments with a highlight on nanomaterials, and discuss the current challenges faced by those agents from the perspective of in vivo applications. Moreover, by generalizing ferroptosis induced by excess iron ions to cell death caused by the polyvalent metal-mediated oxidative burden, we introduce a new paradigm of cancer treatment by exploiting various polyvalent metals to disrupt the vulnerable redox balance in cancer cells, which may greatly diversify our arsenal to combat cancer.
基金This work was supported by Grant of Science and Technology on Microsystem Laboratory (9140C180105150C1809), the RGC Grant (11213414), the National Basic Research Program of China (2012CB933302), and National Natural Science Foundation of China (21390411).
文摘The ability to control cell patterning on artificial substrates with various physicochemical properties is of essence for important implications in cytology and biomedical fields. Despite extensive progress, the ability to control the cell-surface interaction is complicated by the complexity in the physiochemical features of bioactive surfaces. In particular, the manifesta- tion of special wettability rendered by the combination of surface roughness and surface chemistry further enriches the cell-surface interaction. Herein we investigated the cell adhesion behaviors of Circulating Tumor Cells (CTCs) on topog- raphically patterned but chemically homogeneous surfaces. Harnessing the distinctive cell adhesion on surfaces with different topography, we further explored the feasibility of controlled cell patterning using periodic lattices of alternative topographies. We envision that our method provides a designer's toolbox to manage the extracellular environment.
基金supported by the National Natural Science Foundation of China (Grant Nos. 30300083,30800248,60875078,and 81171416)the Natural Science Foundation of Zhejiang Province (Grant No.Z1080300)
文摘In recent years the evolution of olfactory bulb periglomerular cells,as well as the function of periglomerular cells in olfactory encoding,has attracted increasing attention.Studies of neural information encoding based on the analysis of simulation and modeling have given rise to electrophysiological models of periglomerular cells,which have an important role in the understanding of the biology of these cells.In this review we provide a brief introduction to the anatomy of the olfactory system and the cell types in the olfactory bulb.We elaborate on the latest progress in the study of the heterogeneity of periglomerular cells based on different classification criteria,such as molecular markers,structure,ion channels and action potentials.Then,we discuss the several existing electrophysiological models of periglomerular cells,and we highlight the problems and defects of these models.Finally,considering our present work,we propose a future direction for electrophysiological investigations of periglomerular cells and for the modeling of periglomerular cells and olfactory information encoding.
基金supported in part by the Chinese National Natural Science Foundation(Nos.61427817 and61405142)the Independent Innovation Fund of Tianjin University(No.1601)
文摘As microsatellite technology develops,precise inter-satellite measurement shows its significance in distributed satellite systems.In this Letter,a novel technique is proposed for measuring the inter-satellite distance,which adopts optoelectronic resonance and has a function of self-referencing.Resonance cavities have a high spectral purity and a high oscillation frequency.By utilizing the accumulative amplification principle to convert the measurement of distance to that of the frequency,high accuracy is achieved.In the experiment,this measuring scheme has a large measuring range between 1 and 6 km(can be potentially larger),and the accuracy is better than 1.5 urn.The relative accuracy reaches the level of 10^-10.