VUV imaging of type-ⅠELM filamentary structures and their temporal characteristics on EAST

In the H-mode experiments conducted on the Experimental Advanced Superconducting Tokamak(EAST),fluctuations induced by the so-called edge localized modes(ELMs)are captured by a high-speed vacuum ultraviolet(VUV)imaging system.Clear field line-aligned filamentary structures are analyzed in this work.Ion transport induced by ELM filaments in the scrape-off layer(SOL)under different discharge conditions is analyzed by comparing the VUV signals with the divertor probe signals.It is found that convective transport along open field lines towards the divertor target dominates the parallel ion particle transport mechanism during ELMs.The toroidal mode number of the filamentary structure derived from the VUV images increases with the electron density pedestal height.The analysis of the toroidal distribution characteristics during ELM bursts reveals toroidal asymmetry.The influence of resonance magnetic perturbation(RMP)on the ELM size is also analyzed using VUV imaging data.When the phase difference of the coil changes periodically,the widths of the filaments change as well.Additionally,the temporal evolution of the ELMs on the VUV signals provides rise time and decay time for each single ELM event,and the results indicate a negative correlation trend between these two times.

Calculation and prediction of divertor detachment via impurity seeding by using one-dimensional model

Achieving the detachment of divertor can help to alleviate excessive heat load and sputtering problems on the target plates,thereby extending the lifetime of divertor components for fusion devices.In order to provide a fast but relatively reliable prediction of plasma parameters along the flux tube for future device design,a one-dimensional(1D)modeling code for the operating point of impurity seeded detached divertor is developed based on Python language,which is a fluid model based on previous work(Plasma Phys.Control.Fusion 58045013(2016)).The experimental observation of the onset of divertor detachment by neon(Ne)and argon(Ar)seeding in EAST is well reproduced by using the 1D modeling code.The comparison between the 1D modeling and two-dimensional(2D)simulation by the SOLPS-ITER code for CFETR detachment operation with Ne and Ar seeding also shows that they are in good agreement.We also predict the radiative power loss and corresponding impurity concentration requirement for achieving divertor detachment via different impurity seeding under high heating power conditions in EAST and CFETR phase II by using the 1D model.Based on the predictions,the optimized parameter space for divertor detachment operation on EAST and CFETR is also determined.Such a simple but reliable 1D model can provide a reasonable parameter input for a detailed and accurate analysis by 2D or three-dimensional(3D)modeling tools through rapid parameter scanning.

Experimental study of ELM-induced filament structures using the VUV imaging system on EAST

A high-speed vacuum ultraviolet(VUV) imaging system has been developed on the Experimental Advanced Superconducting Tokamak(EAST), which selectively measures line emission with a central wavelength of 13.5 nm(CVI, n=4–2). It has been employed to study edge/pedestal plasma behavior in EAST. Edge localized mode(ELM)-induced filament structures have been captured by the VUV imaging system during the ELMy high confinement mode discharge with both high temporal and spatial resolutions. The typical features(i.e.poloidal width and pitch angle) of the observed filaments are quantitatively characterized based on the VUV imaging data, and the dependence of these features on basic plasma parameters is analyzed. It is found that the poloidal width is proportional to the heating power, and the pitch angle is inversely proportional to the edge safety factor q.95 The scatterplot shows a positive trend between the poloidal width and the ELM amplitude defined by the relative change in stored energy. These results are based on the condition that the perturbation induced by ELMs is confined to a narrow layer in the plasma.

血清Vasohibin-1,TIMP-1对慢阻肺患者急性加重风险的预测价值分析

目的分析血清血管生成抑制蛋白1(vasohibin-1)、金属蛋白酶组织抑制因子-1(TIMP-1)对慢性阻塞性肺疾病(COPD)患者急性加重风险的预测价值。方法以2020年3月—2021年3月经海口市第四人民医院确诊并进行治疗的86例COPD患者作为研究组,根据出院后1年内急性加重的次数分为急性加重风险组(32例)及无急性加重风险组(54例)。将同期来本院体检的60例健康人群作为对照组。所有纳入对象入院后均检测血清Vasohibin-1、TIMP-1水平,并进行组间比较。采用受试者工作特性(ROC)曲线分析血清Vasohibin-1、TIMP-1对COPD急性加重风险的预测价值,同时实施多因素Logistic的回归分析影响COPD急性加重风险的危险因素。结果研究组患者血清Vasohibin-1、TIMP-1水平均明显高于对照组(P<0.05);急性加重风险组患者血清Vasohibin-1、TIMP-1水平明显高于无急性加重风险组(P<0.05)。ROC曲线结果显示,血清Vasohibin-1曲线下面积为0.769,截断值506.52 ng/L,敏感度、特异度分别为94.12%、50.00%;TIMP-1曲线下面积为0.832,截断值272.36 ng/mL,敏感度、特异度分别为94.12%、61.11%;两者联合曲线下面积为0.921,敏感度、特异度分别为84.38%、87.04%。多因素Logistic回归分析结果显示,血清Vasohibin-1[OR(95%CI)=2.90(1.75~8.72)]、TIMP-1[OR(95%CI)=4.14(1.65~10.37)]均为影响COPD患者出现急性加重的危险因素(P<0.05)。结论血清Vasohibin-1、TIMP-1水平在COPD患者中均升高,并且与急性加重风险密切有关,可作为预测COPD患者出现急性加重风险的有效指标物。

ETV2 regulating PHD2-HIF-1α axis controls metabolism reprogramming promotes vascularized bone regeneration

The synchronized development of mineralized bone and blood vessels is a fundamental requirement for successful bone tissue regeneration.Adequate energy production forms the cornerstone supporting new bone formation.ETS variant 2(ETV2)has been identified as a transcription factor that promotes energy metabolism reprogramming and facilitates the coordination between osteogenesis and angiogenesis.In vitro molecular experiments have demonstrated that ETV2 enhances osteogenic differentiation of dental pulp stem cells(DPSCs)by regulating the ETV2-prolyl hydroxylase 2(PHD2)-hypoxia-inducible factor-1α(HIF-1α)-vascular endothelial growth factor A(VEGFA)axis.Notably,ETV2 achieves the rapid reprogramming of energy metabolism by simultaneously accelerating mitochondrial aerobic respiration and glycolysis,thus fulfilling the energy requirements essential to expedite osteogenic differentiation.Furthermore,decreasedα-ketoglutarate release from ETV2-modified DPSCs contributes to microcirculation reconstruction.Additionally,we engineered hydroxyapatite/chitosan microspheres(HA/CS MS)with biomimetic nanostructures to facilitate multiple ETV2-DPSC functions and further enhanced the osteogenic differentiation.Animal experiments have validated the synergistic effect of ETV2-modified DPSCs and HA/CS MS in promoting the critical-size bone defect regeneration.In summary,this study offers a novel treatment approach for vascularized bone tissue regeneration that relies on energy metabolism activation and the maintenance of a stable local hypoxia signaling state.

Experimental observations of naturally occurring dust using a high-speed vacuum ultraviolet imaging system in EAST

In the ELMy H-mode experiment,naturally occurring dust originating at the high-field side is clearly observed using the high-speed vacuum ultraviolet imaging system developed on the Experimental Advanced Superconducting Tokamak(EAST).The main ablation cloud shape is similar to the classical shape observed in pellet fueling experiments.However,during the dust penetration,an erupted secondary cloudlet with a bent‘cigar’shape is observed and moves upwards along the direction perpendicular to the magnetic field line,which is different to the obviation in the pellet fueling experiments.This may be due to the ion diamagnetic drift effect.The velocities of the secondary cloudlet are estimated to be 50–80 m s^(-1).In addition,a significant degradation of the plasma confinement is observed during the dust penetration.

Simulation studies of tungsten impurity behaviors during neon impurity seeding with tungsten bundled charge state model using SOLPS-ITER on EAST

An investigation into tungsten(W)impurity behaviors with the update of the EAST lower W divertor for H-mode has been carried out using SOLPS-ITER.This work aims to study the effect of external neon(Ne)impurity seeding on W impurity sputtering with the bundled charge state model.As the Ne seeding rate increases,plasma parameters,W concentration(C_(W)),and eroded W flux(Γ_(W)^(Ero))at both targets are compared and analyzed between the highly resolved bundled model‘jett’and the full W charge state model.The results indicate that‘jett’can produce divertor behaviors essentially in agreement with the full W charge state model.The bundled scheme with high resolution in low W charge states(<W^(20+))has no obvious effect on the Ne impurity distribution and thus little effect on W sputtering by Ne.Meanwhile,parametric scans of radial particle and thermal transport diffusivities(D_(⊥)andχ_(e,i))in the SOL are simulated using the‘jett’bundled model.The results indicate that the transport diffusivity variations have significant influences on the divertor parameters,especially for W impurity sputtering.

Inflammation responsive tofacitinib loaded albumin nanomedicine for targeted synergistic therapy in ulcerative colitis

Patients with ulcerative colitis(UC)often loss responses over long term usage of conventional therapies.Tofacitinib,a pan-Janus kinases(JAK)inhibitor is approved for moderate to severe UC treatment,while dose-limiting systemic side effects including infections,cancers and lymphoma limit its popularity of clinical application.This study sought to construct an anti-mucosal vascular addressin cell-adhesion molecule-1(anti-MAdCAM-1)antibody modified reactive oxygen species(ROS)responsive human serum albumin-based nanomedicine denoted as THM,to improve the therapeutic efficacy of tofacitinib for UC treatment.THM has the drug releasing properties in response to ROS stimulation.In vitro studies show that THM selectively adhered to the endothelial cells and had obvious anti-inflammatory effect on macrophages.Meanwhile,the nanomedicine can inhibit the phenotypic switching of M1 macrophages and promote M2 polarization to produce anti-inflammatory medicators during wound healing.In addition,in vivo fluorescence imaging verified that THM exhibited enhanced preferential accumulation and extended retention in inflamed colon.Moreover,THM significantly reduced the production of proinflammatory cytokines in the colon and suppressed the homing of T cells to the gut in dextran sodium sulfate induced experimental colitis.This work elucidates that the inflamed colon-targeted delivery of tofacitinib by nanomedicine is promising for UC treatment and sheds light on addressing the unmet medical need.

配位链转移聚合合成高密度聚乙烯-嵌段-等规聚丙烯嵌段共聚物

通过利用配位链转移聚合方法,设计“一锅两步法”合成路线合成了高密度聚乙烯-嵌段-等规聚丙烯两嵌段共聚物.双水杨醛亚胺锆催化剂/甲基铝氧烷催化体系,在二乙基锌作链转移剂的情况下,催化乙烯进行配位链转移聚合,生成双(聚乙烯基)锌并作为大分子链转移剂参与第二步由二甲基吡啶胺铪催化剂催化的丙烯等规聚合反应,最终得到高密度聚乙烯-全同聚丙烯(HDPE-b-iPP)嵌段共聚物.嵌段聚合物的分子量及分布、热性能、微结构等利用高温凝胶色谱(HT-GPC)、示差扫描量热法(DSC)、高温核磁(NMR)进行了明确表征.该类嵌段聚合物可用于增容商业料HDPE/iPP的共混物.扫描电镜(SEM)表征结果显示,通过加入10 wt%嵌段聚合物,共混物(70/30)中分散相粒子尺寸显著减小,两相界面粘结明显改善.

Tauopathy promotes spinal cord-dependent production of toxic amyloid-beta in transgenic monkeys

Tauopathy,characterized by the hyperphosphorylation and accumulation of the microtubule-associated protein tau,and the accumulation of Aβ oligomers,constitute the major pathological hallmarks of Alzheimer's disease.However,the relationship and causal roles of these two pathological changes in neurodegeneration remain to be defined,even though they occur together or independently in several neurodegenerative diseases associated with cognitive and movement impairment.

Reduce Training Error of Extreme Learning Machine by Selecting Appropriate Hidden Layer Output Matrix

Extreme learning machine(ELM)is a feedforward neural network with a single layer of hidden nodes,where the weight and the bias connecting input to hidden nodes are randomly assigned.The output weight between hidden nodes and outputs are learned by a linear model.It is interesting to ask whether the training error of ELM is significantly affected by the hidden layer output matrix H,because a positive answer will enable us obtain smaller training error from better H.For single hidden layer feedforward neural network(SLFN)with one input neuron,there is significant difference between the training errors of different Hs.We find there is a reliable strong negative rank correlation between the training errors and some singular values of the Moore-Penrose generalized inverse of H.Based on the rank correlation,a selection algorithm is proposed to choose robust appropriate H to achieve smaller training error among numerous Hs.Extensive experiments are carried out to validate the selection algorithm,including tests on real data set.The results show that it achieves better performance in validity,speed and robustness.

Growth and characteristics of p-type doped GaAs nanowire

The growth of p-type GaAs nanowires（NWs）on GaAs（111）B substrates by metal-organic chemical vapor deposition（MOCVD）has been systematically investigated as a function of diethyl zinc（DEZn）flow.The growth rate of GaAs NWs was slightly improved by Zn-doping and kink is observed under high DEZn flow.In addition,the Ⅰ–Ⅴ curves of GaAs NWs has been measured and the p-type dope concentration under the Ⅱ/Ⅲ ratio of 0.013 and 0.038 approximated to 1019–1020