Transforming growth factor-beta 1 enhances discharge activity of cortical neurons

Transforming growth factor-beta 1(TGF-β1)has been extensively studied for its pleiotropic effects on central nervous system diseases.The neuroprotective or neurotoxic effects of TGF-β1 in specific brain areas may depend on the pathological process and cell types involved.Voltage-gated sodium channels(VGSCs)are essential ion channels for the generation of action potentials in neurons,and are involved in various neuroexcitation-related diseases.However,the effects of TGF-β1 on the functional properties of VGSCs and firing properties in cortical neurons remain unclear.In this study,we investigated the effects of TGF-β1 on VGSC function and firing properties in primary cortical neurons from mice.We found that TGF-β1 increased VGSC current density in a dose-and time-dependent manner,which was attributable to the upregulation of Nav1.3 expression.Increased VGSC current density and Nav1.3 expression were significantly abolished by preincubation with inhibitors of mitogen-activated protein kinase kinase(PD98059),p38 mitogen-activated protein kinase(SB203580),and Jun NH2-terminal kinase 1/2 inhibitor(SP600125).Interestingly,TGF-β1 significantly increased the firing threshold of action potentials but did not change their firing rate in cortical neurons.These findings suggest that TGF-β1 can increase Nav1.3 expression through activation of the ERK1/2-JNK-MAPK pathway,which leads to a decrease in the firing threshold of action potentials in cortical neurons under pathological conditions.Thus,this contributes to the occurrence and progression of neuroexcitatory-related diseases of the central nervous system.

Isorhamnetin protects porcine oocytes from zearalenone-induced reproductive toxicity through the PI3K/Akt signaling pathway

Background Zearalenone(ZEA)widely exists in moldy grains,which seriously destroys the fertility of females.Isorhamnetin,a natural flavonoid,has extensive of pharmacological activities.However,the beneficial effect and the underlying molecular mechanism of isorhamnetin involvement in ZEA-induced porcine oocyte damage have not been investigated.Methods Oocytes were treated with different concentrations of ZEA(3,5,8 and 10μmol/L)and isorhamnetin(5,10,20 and 30μmol/L)for 44 h at 39℃.ZEA(5μmol/L)and isorhamnetin(10μmol/L)were selected for subsequent studies.Polar body exclusion rate,apoptosis rate and apoptosis related proteins,ROS levels and SOD2 protein,mitochondrial membrane potential and distribution,endoplasmic reticulum distribution and proteins expression,and PI3K,Akt and p-Akt proteins expression of oocytes were detected.In addition,the effect of PI3K antagonist(LY294002)on oocyte nuclear maturation and apoptosis were used to determine the involvement of PI3K/Akt signaling pathway.Results Our findings showed that ZEA exposure damaged oocytes and isorhamnetin therapy restored the developmental capability of porcine oocytes.Isorhamnetin promoted polar body extrusion rate to rescue ZEA-induced meiotic arrest in porcine oocytes.Isorhamnetin alleviated ZEA-induced oxidative stress by stimulating SOD2 protein expression and inhibiting ROS production.Moreover,isorhamnetin enhanced normal mitochondrial distribution and mitochondrial membrane potential to prevent mitochondrial dysfunction induced by ZEA.Changing the expression of endoplasmic reticulum stress-related marker proteins(CHOP,GRP78)and the distribution rate of normal endoplasmic reticulum showed that isorhamnetin relieved ZEA-caused endoplasmic reticulum stress.Mechanistically,isorhamnetin decreased Bax/Bcl-2 protein expression and inhibited ZEA-induced apoptosis through PI3K/Akt signaling pathway.Conclusions Collectively,these results suggest that isorhamnetin protects oocytes from ZEA-caused damage through PI3K/Akt signaling pathway,which enhances meiotic maturation and mitochondrial function,and inhibits early apoptosis,oxidative stress and endoplasmic reticulum stress in porcine oocytes.Our study provides a new strategy for solving the reproductive toxicity induced by ZEA and treating woman infertility.

Numerical simulation and experimental verification of plasma jet development in gas gap switch

Plasma jet triggered gas gap switch has obvious advantages in fast control switch.The development of the plasma in the ambient medium is the key factor affecting the triggering conduction of the gas switch.However,the plasma jet process and its characteristic parameters are complicated and the existing test methods cannot fully characterize its development laws.In this work,a two-dimensional transient fluid calculation model of the plasma jet process of the gas gap switch is established based on the renormalization-group k-εturbulence equation.The results show that the characteristic parameters and morphological evolution of the plasma jet are basically consistent with the experimental results,which verifies the accuracy of the simulation model calculation.The plasma jet is a long strip with an initial velocity of 1.0 km·s-1and develops in both axial and radial directions.The jet velocity fluctuates significantly with axial height.As the plasma jet enters the main gap,the pressure inside the trigger cavity drops by80%,resulting in a rapid drop in the jet velocity.When the plasma jet head interacts with the atmosphere,the two-phase fluid compresses each other,generating a forward-propelled pressure wave.The plasma jet heads flow at high velocity,a negative pressure zone is formed in the middle part of the jet,and the pressure peak decreases gradually with height.As the value of the inlet pressure increases,the characteristic parameters of the plasma jet increase.The entrainment phenomenon is evident,which leads to an increase in the pressure imbalance of the atmospheric gas medium,leading to a significant Coanda effect.Compared with air,the characteristic parameters of a plasma jet in SF6are lower,and the morphological evolution is significantly suppressed.The results of this study can provide some insight into the mechanism of action of the switch jet plasma development process.

青藏高原植被结构变化反映环境变迁

草地植被结构对于其生产和生态功能至关重要,但大尺度信息严重匮乏.本研究结合多源遥感数据和深度学习,在区域尺度上厘清了青藏高原高寒草地基于群系的植物群落结构空间格局,并比较了其历史变化.过去40年,高寒草甸在高寒草地中的比例从50%上升到69%,反映了变暖变湿的环境变化.此外,高寒草甸和高寒草原中高山嵩草草甸和紫花针茅草原的优势度分别增强到76%和92%.其中,气候因子驱动了紫花针茅草原近些年的分布;高山嵩草草甸近些年的分布则并非完全由气候驱动,人类活动可能起重要作用.本研究首次探索了区域尺度植被结构特征与历史变化,为认识青藏高原草地变化的驱动力及其空间异质性提供了新视角.

Collaborative optimization of linear vibrating screen screening efficiency and dynamic response stability based on coupled DEM-MBK simulation

The dynamic response stability of the vibrating screen is an important factor affecting the screening effect and the structural performance of the vibrating screen.In this paper,to improve dynamic response stability and screening efficiency,we optimized the configuration of linear screening process parameters based on the co-optimization method with dual objectives via the virtual experiment.Firstly,a coupled DEM-MBK simulation model was established according to the dynamics of linear screen,and the dy-namic response law of the screen machine under material impact was investigated.Secondly,the quantitative index of dynamic response stability according to the time-domain characteristics of the centroid amplitude was established.The trend and significance of three types of screening process pa-rameters,including excitation,damping and structure,on the screening efficiency and dynamic response stability were analyzed through virtual orthogonal experiments.Finally,a parameter configuration scheme to achieve co-optimization was proposed based on the comprehensive balance method.The virtual experiment results show that the screening efficiency and dynamic response stability of the proposed scheme are improved by 3.28%and 49.07%,respectively,compared with the empirical parameter configuration.Obviously,the co-optimization method can maintain high screening efficiency and dynamic response stability at the same time,which is beneficial to improve the service life of the screen surface and screen body.

State of the art in flexible SERS sensors toward label-free and onsite detection:From design to applications

Surface-enhanced Raman scattering(SERS)as a powerful non-invasive spectroscopic technique has been intensively used in bio/chemical sensing,enabling ultrasensitive detection of various analytes and high specificity with a fingerprint-like characteristic.Flexible SERS sensors conformally adapting to nonplanar surfaces and allowing swab-sampling or in-situ detection of analytes,which are not achievable for rigid SERS sensors,greatly meet the demand of onsite and real-time diagnostics.However,the rational design and fabrication of flexible SERS-based sensors for point-of-care diagnostics aiming to simultaneously achieve extremely high sensitivity,stability,and good signal reproducibility remain many challenges.We present a state-of-the-art review of the flexible SERS sensors.Attentions are devoted to engineering plasmonic substrates for improving the performance of flexible SERS devices.Strategies of constructing the flexible SERS sensors toward point-of-care detection are investigated in depth.Advanced algorithms assisting the SERS data process are also presented for intelligently distinguishing the species and contents of analytes.The promising applications of flexible SERS sensors in medical diagnostics,environmental analyses,food safety,and forensic science are displayed.The flexible SERS devices serving as powerful analytical tools shed new light on the in-situ and point-of-care detection of real-world analytes in a convenient,facile,and non-destructive manner,and especially are conceivable to serve as next-generation wearable sensors for healthcare.

Isorhamnetin protects zearalenone-induced damage via the PI3K/Akt signaling pathway in porcine ovarian granulosa cells

Zearalenone(ZEA)is widely derived from moldy cereal grain,which has adverse effects on animal reproduction.In particular,pigs are more sensitive to ZEA-induced toxicity than other animals.Isorhamnetin has extensive pharmacological activity.However,the role of isorhamnetin in ZEA-induced cytotoxicity remains unclear.This study was designed to investigate the therapeutic effect of isorhamnetin on ZEA-induced damage in porcine ovarian granulosa cells and elucidate its molecular mechanism.Two experiments were conducted,where a minimum of 3 biological replicates were used for each treatment.In Exp.1,ovarian granulosa cells were treated with different concentrations of isorhamnetin(1,5,10,20 and 30μmol/L)and ZEA(0,10,30,60,90 and 120μmol/L)for 24 h.Our results indicated that 60μmol/L ZEA(half-maximal inhibitory concentration value)and 20μmol/L isorhamnetin(the most effective concentration against ZEA-induced cytotoxicity)were optimum concentrations.In Exp.2,ovarian granulosa cells were treated with isorhamnetin(20μmol/L)for 2 h,before treatment with ZEA(60μmol/L)for 24 h.Apoptosis,endoplasmic reticulum stress,oxidative stress,proliferation and hormone secretion of ovarian granulosa cells were detected.Our findings showed that isorhamnetin suppressed(P<0.05)ZEA-induced apoptosis by altering mitochondrial membrane potential and apoptosis-related proteins(B-cell lymphoma-2[Bcl-2],Bcl2-associated x[Bax]and cleaved caspase-3[C-Casp3]).Changes in intracellular Ca2+levels and C/EBP homologous protein(CHOP),recombinant activating transcription factor 6(ATF6),glucose regulated protein78 k D(GRP78)indicated that isorhamnetin rescued(P<0.05)ZEA-induced endoplasmic reticulum stress.Furthermore,isorhamnetin prevented(P<0.05)ZEA-induced oxidative stress via the mitogen-activated protein kinase(P38)signaling pathway.Mechanistically,isorhamnetin stimulated(P<0.05)the expression of proliferating cell nuclear antigen(PCNA)and cyclin D,thereby increasing the ratio of S phase cells in response to ZEAinduced apoptosis via phosphatidylinositol 3 kinase/protein kinase B(PI3K/Akt)signaling pathway.Isorhamnetin also recovered(P<0.05)ZEA-induced steroidogenesis disorder by regulating steroidogenic enzyme gene and proteins(follicle-stimulating hormone receptor[FSHR]and cytochrome P450 family 19subfamily a member 1[CYP19A1]).Collectively,these findings show that isorhamnetin protects ovarian granulosa cells from ZEA-induced damage,which promotes proliferation,alleviates apoptosis,endoplasmic reticulum stress,oxidative stress,and steroidogenesis disorder.

Multi-scale image segmentation of coal piles on a belt based on the Hessian matrix

Segmenting images of coal piles on a belt is an unsolved problem in coal-based machine vision research, though it is an essential step for estimating size distribution and classifying coal. In this investigation, a new algorithm for segmenting images of coal piles on a belt is proposed. A multi^scale linear filter, constructed of a Hessian matrix and Gaussian function, forms the core of this algorithm and obtains an edge intensity image to form good seed regions for a watershed segmentation. Manual segmentation is used to define ground truth segmentation images to quantify the errors of the proposed method. Tests indicate that 12.76% of the visible regions are under- or over-segmented, and that this algorithm is feasible and effective in practical applications.

Numerical analysis of deflection control of a gas plasma jet based on magnetohydrodynamic staggered electrode configuration

To control the deflection of the gas plasma jet, a new analytical method is proposed based on the Magnetohydrodynamic(MHD) technique. Based on the typical MHD power generation model, the applied voltage is applied to the staggered electrodes, that is, a pair of electrodes on the same side wall are connected to generate an axial current in the channel. Under the action of the magnetic field perpendicular to the direction of the flow, the plasma is subjected to electromagnetic forces perpendicular to these two directions, and the jet is deflected. The computational model including the Navier-Stokes equations coupled with electromagnetic source terms, the electric potential equation and Ohm’s law is solved. The deflection of the gas jet under the action of an electromagnetic field is observed, and the maximum deflection angle is about 14.8°. The influences of the electric field, magnetic field, and conductivity on the jet deflection are studied. Results show that although the influences of these three factors on the deflection are similar, and the effect of increasing the electric field strength is slightly greater, priority should be given to increasing the magnetic field strength from the perspective of reducing energy consumption. The Stuart number is introduced to assess the ability of electromagnetic force to control jet deflection. When the electromagnetic parameters are constant, this solution provides better control of low-density and low-speed fluid flows. The calculation results show that using the staggered electrode method configuration is feasible in terms of controlling the deflection of a plasma jet deflection.

Collaborative optimization of screening efficiency and screen surface load-PartⅠ:Modeling and evaluation

The screen surface load(SSL)caused by granular materials is an important factor affecting the structural performance of vibrating screen.Based on virtual experiment,a multi-objective collaborative optimiza-tion method is proposed to control the SSL under high screening efficiency(SE)in this work.Firstly,a DEM model was established to study the influence of process parameters on SE and SSL.Secondly,the NSGA-Ⅱ(Non-dominated Sorting Genetic Algorithm)was employed to optimize the screening parameters with both SE and SSL as targets.The optimization method proves to be effective implementing on a linear vibrating screening.With SE equals to 98.5%,the SSL optimizable range is 39.2%.While compromising the SE to 88.7%,the SSL optimizable range improves to 48.6%.The result shows that the collaborative optimization could effectively control the SSL while maintaining a high SE,which is of great significance to improve the service life of screen surface and screen body.

The Dynamics of Online Purchase Visits： Inertia or Switching？

This paper studies the dynamics of online purchase patterns, focusing on the impact of the channel used on conversion probability, as well as the transition of channel use over time. A novel data set from a major Chinese online travel agency is used for analysis, consisting of four months of data with 24,337 store visits through three types of channels： direct visit, search advertising and referral. Results of a Bayesian multinomial logit model show that the search channel significantly affects consumers＇ conversion probability, and show a high degree of inertia in channel use. This finding contrasts sharply with suggestions of previous research that most future purchases will converge to the direct-visit channel.