A Novel Location Method for Interline Power Flow Controllers Based on Entropy Theory

As one of the new generation flexible AC transmission systems(FACTS)devices,the interline power flow controller(IPFC)has the significant advantage of simultaneously regulating the power flow of multiple lines.Nevertheless,how to choose the appropriate location for the IPFC converters has not been discussed thoroughly.To solve this problem,this paper proposes a novel location method for IPFC using entropy theory.To clarify IPFC’s impact on system power flow,its operation mechanism and control strategies of different types of serial converters are discussed.Subsequently,to clarify the system power flow characteristic suitable for device location analysis,the entropy concept is introduced.In this process,the power flow distribution entropy index is used as an optimization index.Using this index as a foundation,the power flow transfer entropy index is also generated and proposed for the IPFC location determination study.Finally,electromechanical electromagnetic hybrid simulations based on ADPSS are implemented for validation.These are tested in a practical power grid with over 800 nodes.A modular multilevel converter(MMC)-based IPFC electromagnetic model is also established for precise verification.The results show that the proposed method can quickly and efficiently complete optimized IPFC location and support IPFC to determine an optimal adjustment in the N-1 fault cases.

Studying Alzheimer’s Disease Using Drosophila melanogaster as a Powerful Tool

Background: Alzheimer’s disease (AD) is an increasingly prevalent neurodegenerative disease characterized by protein aggregation in the form of amyloid plaques containing beta-amyloid peptides and neurofibrillary tangles containing hyperphosphorylated tau protein. The central molecular events underlying AD pathogenesis remain controversial and poorly defined. Drosophila melanogaster has emerged as an important genetic resource for studying the pathology of AD. Many AD models have been created using Drosophila, taking advantage of its short generation times, sophisticated genetic tools, and abundance of homologs to human genes. Purpose: This review summarizes different models for studying AD in Drosophila melanogaster, including the full-length APP, C99, Aβ42 and Tau models, explaining how the models were built and what we have learned from them. Conclusion: Four main AD Drosophila models are introduced in this review, which can serve as a future method to investigate genes and drugs that can modify symptoms.

双子表面活性剂及其抗菌性能

双子表面活性剂是一种具有两个亲水基团、两条疏水链和一个联接基团的新型表面活性剂。与传统的表面活性剂相比,双子表面活性剂具有较低的临界胶束浓度、较高的表面活性、高效降低水的表面张力和油/水界面张力以及良好的水溶性等特点。双子表面活性剂广泛应用于抑菌、灭菌、食品生产、消泡抑泡、药物缓释以及工业清洗等领域,对推动社会、经济、工业的进步有着非常重要的积极作用。本文简要概括了双子表面活性剂的发展,介绍了双子表面活性剂的活性和组装结构,对双子表面活性剂的分类、结构和特征进行了概括和总结。

Fabrication of 3D hollow acorn-shell-like PtBi intermetallics via a surfactant-free pathway for efficient ethylene glycol electrooxidation

The synthesis of atomically ordered Pt-based intermetallic electrocatalysts for the direct alcohol fuel cells generally requires the addition of surfactants or the high-temperature annealing.However,some residual surfactants on the surface of the assynthesized catalysts would prevent the exposure of catalytic active sites,the high-temperature annealing process is easy to accelerate the sintering of the metal,which both lead to the decline of electrocatalytic performance.Herein,we construct the atomically ordered bimetallic PtBi intermetallics with clean surfaces and unique three-dimensional hollow acorn-shell-like structure(3D PtBi HASL)by a simple,low-temperature,surfactant-free one-pot synthetic approach.Benefiting from the special hollow structures,the obtained 3D PtBi HASL intermetallics expose abundant accessible active sites.Moreover,the introduction of oxophilic metal Bi can enhance adsorption of OHads,thereby significantly facilitating removal of poisoned intermediates.Density functional theory(DFT)simulations further indicate that formation of the PtBi intermetallic phase with the downshift of the Pt d-band center endows 3D Pt49.4Bi50.6 HASL intermetallics with significantly attenuated COads and enhanced OHads adsorption,bringing about the boosting electrocatalytic property.The mass activity of the 3D Pt49.4Bi50.6 HASL intermetallics for ethylene glycol oxidation reaction is as high as 24.67 A·mgPt^(−1),which is 12.98 times higher than that of commercial Pt/C(1.90 A·mgPt^(−1)).This work may inspire the design of Pt-based intermetallics as high-efficiency anode electrocatalysts for fuel cell applications.

Study on the Protective Mechanism of Acupuncture Regulating ICAM-5 mRNA Expression in Rats with Ischemic Stroke

Objective: The objective is to investigate whether acupuncture can protect brain by regulating the expression of ICAM-5 mRNA in brain tissue. Methods: Male SD rats were used to construct a middle cerebral artery occlusion reperfusion injury (Middle cerebral artery occlusion, MCAO) model, and the rats were randomly divided into 4 groups, namely the normal group (group A) and the sham operation group (group B), MCAO group (group C), MCAO + acupuncture group (group D);real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression of ICAM-5 mRNA in the brain tissue of the ischemic area, and HE staining and TUNEL were used to detect the level of neuronal apoptosis to evaluate the therapeutic effect. Results: Acupuncture can improve neuronal morphology and reduce neuronal apoptosis in rats with ischemic stroke. RT-qPCR: compared with group A and group B, the expression level of ICAM-5 mRNA in the brain tissues of group C and group D decreased, while compared with group C, The expression of ICAM-5 mRNA in the brain tissue of group D was significantly up-regulated (P < 0.05). There was no statistical difference between group A and group B (P > 0.05). Conclusion: The effectiveness of acupuncture in the treatment of ischemic stroke may achieve neuroprotection by up-regulating the expression level of ICAM-5 mRNA.

Experimental Study on the Effect of Acupuncture on ERM/PI3/Akt Signal Pathway in Rats with Ischemic Stroke

Objective: To observe the effect of acupuncture on the expression of ERM/PI3K/Akt signaling pathway in the brain tissue around the infarct focus of ischemic stroke model rats. Methods: According to the block randomization method, 80 male SD rats were divided into normal group (n = 10), sham operation group (n = 24), model group (n = 23) and acupuncture group (n = 23). The normal group was bred routinely without any intervention. In the sham operation group, only the skin was cut to find and the nerves and blood vessels were stripped and sutured. The model group and the acupuncture group were sutured to prepare the MCAO model. After the model was successfully established, acupuncture of the acupuncture group rats was given once a day, and the needles were kept for 30 minutes each time. The rats in the sham operation group and the model group only imitated capture and return, and were treated with acupuncture for 2 consecutive courses, each course was 5 days, and the two courses were rested for 2 days. After that, Western blot was used to detect ERM, changes in the concentration of PI3K and Akt proteins. Results: Compared with the normal group, the expression levels of ERM, PI3K, and Akt proteins in the sham operation group were reduced. Compared with the sham operation group, the expression levels of ERM, PI3K, and Akt proteins in the model group were significantly down-regulated. Compared with the model group, the protein expression levels of ERM, PI3K and Akt were significantly up-regulated in the acupuncture group, and the difference was statistically significant (P < 0.05). Conclusion: Acupuncture can significantly up-regulate the expression of ERM, PI3K and Akt proteins, and its effect mechanism may be related to the transduction of ERM/PI3K/Akt signaling pathway in cells.

Morphology controllable urchin-shaped bimetallic nickel-cobalt oxide/carbon composites with enhanced electromagnetic wave absorption performance

The microscopic morphology of electromagnetic wave absorbers influences the multiple reflections of electromagnetic waves and impedance matching,determining the absorption properties.Herein,the urchin-shaped bimetallic nickel-cobalt oxide/carbon(NiCo_(2)O_(4)/C)composites are prepared via a hy-drothermal route,whose absorption properties are investigated by different morphologies regulated by changing calcination temperature.A minimum reflection loss(RL_(min))of-75.26 dB is achieved at a match-ing thickness of 1.5 mm,and the effective absorption bandwidth(EAB)of 8.96 GHz is achieved at 2 mm.Multi-advantages of the synthesized NiCo_(2)O_(4)/C composites contribute to satisfactory absorption proper-ties.First,the interweaving of the needle-like structures increases the opportunities for scattering and multiple reflections of incident electromagnetic waves,and builds up a conductive network to facilitate the enhancement of conductive losses.Second,the carbon component in the NiCo_(2)O_(4)/C composites en-hances the interfacial polarization and reduces the density of the absorber.Besides,generous oxygen va-cancy defects are introduced into the NiCo_(2)O_(4)/C composites,which induces defect polarization and dipole polarization.In summary,the ternary coordination of components,defects and morphology led to out-standing electromagnetic wave absorption,which lightened the path for improving the electromagnetic wave absorption property and enriching the family of NiCo_(2)O_(4) absorbers with excellent performance.

Immune microenvironment-reshaping Au@Bi_(2)Te_(3) nanoparticles for spectral computed tomography/photoacoustic imaging-guided synergetic photo/radio/immunotherapy

Radiotherapy(RT)mediated tumor immunogenicity offers an opportunity for simultaneous RT and immunotherapy via immunogenic cell death(ICD),which releases damaged-associated molecular patterns and generates“eat me”signals for the innate immune system to modulate the immunogenicity.However,tumor hypoxia significantly reduces the therapeutic efficacy of RT and hampers its mediation of ICD induction.Herein,Au@Bi_(2)Te_(3)-polyethylene glycol(PEG)was rationally constructed as theranostic nanozymes for mild photothermal therapy,tumor hypoxia modulation,and RT adjuvant cancer immunotherapy.The tumor-specific production of oxygen could not only augment the effects of RT by enhanced reactive oxygen species(ROS)generation,but also reduce hypoxia-related cytokines and downregulate programmed cell death-ligand 1(PD-L1)to unleash immune-enhancing T cells.Moreover,Au@Bi_(2)Te_(3)-PEG could act as an immune-blocking inhibitor by efficient ICD induction with the combination of mild-photothermal therapy+RT to inhibit the tumor immune escape and improve antitumor immune response.Increased amounts of CD^(4+) and CD^(8+) Tcells and elevated levels of cytokines could be observed that eventually led to effective post-medication inhibition of primary and abscopal tumors.Spectral computed tomography/photoacoustic imaging allowed noninvasive and real-time tracking of nanoparticle(NP)accumulation and oxygenation status at tumor sites.Collectively,Au@Bi_(2)Te_(3)-PEG NPs could serve as effective theranostic nanoregulators with remarkable synergistic mildphotothermal/RT/immunotherapy effects that helped reshape the immune microenvironment and had remarkable molecular imaging properties.

基于声学超材料的穿孔板缺陷态俘能特性研究

论文提出了一套适用于在低频段区间工作的声学超材料俘能装置.通过在含孔的声学超材料结构中制造一个局域共振缺陷态,进而将入射声波的弹性应变能集中在缺陷区域中,并利用压电晶片实现能量的转化.论文采用有限元的方法研究了元胞含孔的声学超材料在共振频率下俘获功率与电压的性能.进一步地,通过逐渐改变孔的尺寸,探究了孔径大小对俘能效果的影响.数值计算结果表明:相比于元胞不含孔的声学超材料俘能装置,通过在元胞上打孔可以明显地提高装置在低频段的俘能特性.论文提出的装置具有易加工,实用性强等优点,进一步提高了其在低频区间俘能的工作能力,具有潜在的应用前景.

Evaluation of the efficacy and safety of hydroxychloroquine in comparison with chloroquine in moderate and severe patients with COVID-19

Dear Editor,Since December 2019,severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has been rapidly spreading worldwide.Hydroxychloroquine and chloroquine are candidates for the treatment of coronavirus disease 2019(COVID-19)owing to its antiviral effect and immunomodulation properties.

Assessment and prediction of the effect of ageing on the adsorption of nonylphenol in black carbon-sediment systems

Black carbon(BC)is a promising sediment amendment,as proven by its considerable adsorption capacity for hydrophobic organic pollutants and accessibility,but its reliability when used for the removal of pollutants in natural sediments still needs to be evaluated.For example,the ageing process,resulting in changing of surface physicochemical properties of BC,will decrease the adsorption capacity and performance of BC when applied to sediment pollution control.In this study,how the ageing process and BC proportion affect the adsorption capacity of BC-sediment systems was modelled and quantitatively investigated to predict their adsorption capacity under different ageing times and BC additions.The results showed that the ageing process decreased the adsorption capacity of both BC-sediment systems,due to the blockage of the non-linear adsorption sites of BC.The adsorption capacity of rice straw black carbon(RC)-sediment systems was higher than that of fly ash black carbon(FC)-sediment systems,indicating that RC is more efficient than FC for nonylphenol(NP)pollution control in sediment.The newly established model for the prediction of adsorption capacity fits the experimental data appropriately and yields acceptable predictions,especially when based on parameters from the Freundlich model.However,to fully reflect the influence of the ageing process on BC-sediment systems and make more precise predictions,it is recommended that future work considering more factors and conditions,such as modelling of the correlation between the adsorption capacity and the pore volume or specific surface area of BC,be applied to build an accurate and sound model.

Palladium-catalyzed asymmetric carbamoyl-carbonylation of alkenes

An unprecedented palladium-catalyzed asymmetric carbamoyl-carbonylation of tethered alkenes with CO and alcohols has been developed.This reaction provided an efficient route to access oxindoles andγ-lactams bearingβ-carbonyl substituted quaternary carbons in good yields with excellent chemo-,regio-and enantioselectivity.Gram-scale synthetic capability and facile transformations of the products to chiral spirooxindole and other functional molecules further illustrated the practicability of this reaction.

Site-Selective Palladium-Catalyzed 1,1-Arylamination of Terminal Alkenes

Many of the commonly used pharmaceuticals and biologically active natural products are nitrogencontaining compounds.Recently,the transitionmetal-catalyzed or the radical-mediated 1,2-carboamination of alkenes has been well explored to access amine scaffolds.However,synthetic strategies toward the 1,1-carboamination of alkenes are severely limited.Herein,we describe a method to achieve the 1,1-arylamination using readily available building blocks enabled by palladium catalysis.This sequential three step-Heck arylation,metal migration,followed by aza-1,6-Micheal addition process exhibits excellent chemo-and regioselectivity.To showcase the potential as a method for diversity-oriented drug discovery,the modification of numerous structurally complex bioactive molecules was also successfully performed.