基于深度残差神经网络的电阻层析成像及流型辨识方法

针对电阻层析成像(electrical resistance tomography,ERT)反问题成像精度和流型识别准确率偏低的问题,提出一种基于深度残差神经网络的两相流电阻层析成像及流型识别方法。利用有限元法对ERT正问题建模,构造多种气液两相流分布状态的“边界电压–电导率分布–流型类别”数据集。搭建用于气液两相流ERT图像重建和流型辨识的残差神经网络模型并进行网络训练,将残差神经网络的两个输出分别进行数据处理,得到重建的电导率分布图像和流型辨识结果。仿真与静态实验结果表明:该方法能够同时实现成像及流型辨识的需求,具有重建图像精度高、泛化性和抗噪性强、流型辨识准确度高的特点。

Consumer use intention of online financial products:the Yuebao example

Drawing on a valence framework and innovation diffusion theory,this study examines Yuebao deployment to model consumers’intention to use financial products offered online.We collect data via an online survey among a young age bracket and use a VisualPLS graphic interface to test our model.The results indicate that first,compatibility and advantages in relative utility significantly enhance consumers’use intentions and that ease of use has an indirect influence.Second,the negative utility of perceived risk no longer significantly affects intention to use.This mainly lies in consumers’perceived risk focused on the security of online financial products,which has become a part of all online transactions.Third,trust indirectly affects intention to use by influencing utility.

High-quality total RNA extraction from Magnolia sieboldii K.Koch seeds:a comparative evaluation

Magnolia sieboldii K. Koch seed is characterized with having deep dormancy. The inner molecular regulation mechanism has not been investigated because of the absence of a protocol for total RNA(ribonucleic acid)extraction. The extraction of high-quality RNA is important and can be a limiting factor in plant molecular biology experiments. Sufficient high-quality total RNA is required to elucidate the molecular regulation mechanism of germination. However, M. sieboldii seeds with large amounts of secondary metabolites also contain recalcitrant tissues for RNA isolation. We found two simple and low-cost RNA extraction methods for M. sieboldii seeds by evaluating and selecting eight types of methods and further optimizing these methods. The two methods were not only suitable for extracting M. sieboldii seed RNA but also applicable to RNAs from several other tissues. Total RNA extracted through these approaches was applicable for general molecular biology experiments such as qRT-PCR(quantitative real-time polymerase chain reactions). The protocols also meet the strict harsh requirements for transcriptome sequencing and small RNA sequencing. This study provides a powerful approach for future studies at the transcription level.

The complete chloroplast genomic landscape and phylogenetic analyses of Populus alba L.

Populus alba is a foundation species in evolutionary and ecological studies in the northern hemisphere.In this study,the chloroplast genome and gene map of P.alba were constructed.The P.alba chloroplast genome is 156,505 bp in length comprising a large single-copy region,two inverted repeat regions and a small single-copy region.The genome contains 131 genes,including 86 protein-coding genes(77 PCG species),eight ribosomal RNA genes(four rRNA species)and 37 transfer RNA genes(30 tRNA species).Phylogenetic analysis indicates that all Populus chloroplast genome sequences are clustered together and divided into three large branches.Among reported Populus chloroplast genomes,the leuce section formed monophyletic,indicating that all Populus spp.have a common maternal ancestor.P.rotundifolia and P.tremula are closely related and are sisters to P.davidiana.P.alba is closely related to P.adenopoda.Population genetic research in ecology and evolution may be easily developed through chloroplast genomes as they are conserved.This research will benefit future studies related to Populus,one of the world’s most ecologically and economically important genera.

Study of Local Structural Changes on Air Cooling at the End of Rotor Windings for Variable Speed Pumped Storage Generator-Motor

The shrink fit retaining ring is currently the easiest to install and the most widely used end fixed for structure AC excitation variable speed generator-motor rotor end windings.However,the current research on the effect of high strength sealing on the ventilation and heat dissipation performance of the end is not enough.In this paper,based on the actual structural parameters and periodic symmetry simplification,the three-dimensional coupled calculation model of fluid field and temperature field is established.After solving the fluid and thermal equations,the influence of the length of rotor support block,the height of rotor support block,and the number of rotor support block on the fluid flow and temperature distribution in the rotor end region of generator-motor is studied using the finite volume method.The rheological characteristics of the air in the rotor domain,such as velocity and inter-winding flow,are analyzed.The law of temperature variation with local structure in the computational domain is studied.The variation law of cooling medium performance inside the large variable speed power generator motor is revealed.

Tacrolimus combined with arsenic trioxide provides a three-in-one drug-eluting coronary stent integrating anti-restenosis,pro-endothelialization and anti-inflammation

The limitations of current drug-eluting stent technologies in selectively inhibiting vascular smooth muscle cell proliferation,which often leads to inflammation,call for innovative approaches in coronary artery disease treatment.In the present work,we propose a revolutionary solution:a three-in-one platform for vascular stents,combining arsenic trioxide(ATO)and tacrolimus(TAC)to address anti-proliferation,pro-endothelialization,and anti-inflammation aspects.Our findings demonstrate that the synergistic action of ATO and TAC effectively suppresses aberrant vascular smooth muscle cell proliferation and mitigates endothelial cell inflammation.Remarkably,the combination treatment of TAC/ATO enhances endothelial cell migration and adhesion abilities.Moreover,our TAC/ATO-eluting stent exhibits superior re-endothelialization and anti-restenosis effects in a rabbit and porcine stent implantation model.Both in vitro and in vivo results solidify the notion that the TAC/ATO-eluting stent ensures rapid re-endothelialization and significantly reduces the incidence of in-stent restenosis.Overall,this study represents a promising and novel multifunctional platform with immense potential in the therapy of coronary artery disease.

Insulation Properties and Degradation Mechanism for XLPE Subjected to Different Aging Periods

Due to its excellent insulation and mechanical properties,cross-linked polyethylene(XLPE)is widely used as the insulation candidate of power cables in power transmission and distribution systems.However,its performance can be affected due to various stresses,which endangers safe operation of the power system in service.In this paper,dielectric and insulation properties of XLPE materials of 110 kV cables with the service lives of 0,15,and 30 years were tested and evaluated.Results show that with increase of service life,dielectric loss caused by the polarization process increases significantly,and dielectric strength decreases as well.Power frequency breakdown field strength and crystallinity decrease significantly,and carbonyl index increases.The degradation process of XLPE can be divided into two stages:the structure of the crystalline region of the original sample is relatively complete,and loss can be almost ignored.After long-term service,the crystallization region is destroyed,and thermal oxygen reaction occurs.Intermolecular force is weakened,which makes breakdown easier to occur.However,there is no direct relation between the carbonyl index and macroscopic characteristics.This paper reveals the deterioration law of the XLPE cable insulation,which provides a theoretical basis for evaluating cable aging condition and is of great significance to improve cable operation safety and maintenance quality.

Dose selection of chloroquine phosphate for treatment of COVID-19 based on a physiologically based pharmacokinetic model

Chloroquine(CQ)phosphate has been suggested to be clinically effective in the treatment of coronavirus disease 2019(COVID-19).To develop a physiologically-based pharmacokinetic(PBPK)model for predicting tissue distribution of CQ and apply it to optimize dosage regimens,a PBPK model,with parameterization of drug distribution extrapolated from animal data,was developed to predict human tissue distribution of CQ.The physiological characteristics of time-dependent accumulation was mimicked through an active transport mechanism.Several dosing regimens were proposed based on PBPK simulation combined with known clinical exposure-response relationships.The model was also validated by clinical data from Chinese patients with COVID-19.The novel PBPK model allows indepth description of the pharmacokinetics of CQ in several key organs(lung,heart,liver,and kidney),and was applied to design dosing strategies in patients with acute COVID-19(Day 1:750 mg BID,Days 2-5:500 mg BID,CQ phosphate),patients with moderate COVID-19(Day 1:750 mg and 500 mg,Days 2-3:500 mg BID,Days 4-5:250 mg BID,CQ phosphate),and other vulnerable populations(e.g.,renal and hepatic impairment and elderly patients,Days 1-5:250 mg BID,CQ phosphate).A PBPK model of CQ was successfully developed to optimize dosage regimens for patients with COVID-19.

The biological responses and mechanisms of endothelial cells to magnesium alloy

Due to its good biocompatibility and degradability,magnesium alloy(Mg alloy)has shown great promise in cardiovascular stent applications.Rapid stent re-endothelialization is derived from migrated and adhered endothelial cells(ECs),which is an effective way to reduce late thrombosis and inhibit hyperplasia.However,fundamental questions regarding Mg alloy affecting migration and adhesion of ECs are not fully understood.Here,we evaluated the effects of Mg alloy on the ECs proliferation,adhesion and migration.A global gene expression profiling of ECs co-culturing with Mg alloy was conducted,and the adhesion-and migration-related genes were examined.We found that Mg alloy had no adverse effects on ECs viability but significantly affected ECs migration and adhesion.Co-cultured with Mg alloy extract,ECs showed contractive adhesion morphology and decreased motility,which was supported by the down-regulation of adhesion-related genes(Paxillin and Vinculin)and migration-related genes(RAC 1,Rho A and CDC 42).Accordingly,the re-endothelialization of Mg alloy stent was inhibited in vivo.Our results may provide new inspiration for improving the broad application of Mg alloy stents.

Magnetic flux control of chiral Majorana edge modes in topological superconductor

We study the transport of chiral Majorana edge modes(CMEMs) in a hybrid quantum anomalous Hall insulator-topological superconductor(QAHI-TSC) system in which the TSC region contains a Josephson junction and a cavity. The Josephson junction undergoes a topological transition when the magnetic flux through the cavity passes through half-integer multiples of magnetic flux quantum. For the trivial phase, the CMEMs transmit along the QAHI-TSC interface as without magnetic flux. However, for the nontrivial phase, a zero-energy Majorana state appears in the cavity, leading to that a CMEM can resonantly tunnel through the Majorana state to a different CMEM. These findings may provide a feasible scheme to control the transport of CMEMs by using the magnetic flux and the transport pattern can be customized by setting the size of the TSC.

Yes-associated protein contributes to magnesium alloy-derivedinflammation in endothelial cells

Magnesium alloy(Mg alloy)has attracted massive attention in the potential applications of cardiovascular stents because of its good biocompatibility and degradability.However,whether and how the Mg alloy induces inflammation in endothelial cells remains unclear.In the present work,we investigated the activation of Yes-associated protein(YAP)upon Mg alloy stimuli and unveiled the transcriptional function in Mg alloy-induced inflammation.Quantitative RT–PCR,western blotting and immunofluorescence staining showed that Mg alloy inhibited the Hippo pathway to facilitate nuclear shuttling and activation of YAP in human coronary artery endothelial cells(HCAECs).Chromatin immunoprecipitation followed sequencing was carried out to explore the transcriptional function of YAP in Mg alloy-derived inflammation.This led to the observation that nuclear YAP further bonded to the promoter region of inflammation transcription factors and co-transcription factors.This binding event activated their transcription and modified mRNA methylation of inflammation-related genes through regulating the expression of N6-methyladenosine modulators(METTL3,METTL14,FTO and WTAP).This then promoted inflammation-related gene expression and aggravated inflammation in HCAECs.In YAP deficiency cells,Mg alloy-induced inflammation was reduced.Collectively,our data suggest that YAP contributes to the Mg alloy-derived inflammation in HCAECs and may provide a potential therapeutic target that alleviates inflammation after Mg alloy stent implantation.