Synthesis and high temperature thermoelectric transport properties of Si-based type-Ⅰ clathrates

N-type Si-based type-Ⅰ clathrates with different Ga content were synthesized by combining the solid-state reaction method,melting method and spark plasma sintering （SPS） method.The effects of Ga composition on high temperature thermoelectric transport properties were investigated.The results show that at room temperature,the carrier concentration decreases, while the carrier mobility increases slightly with increasing Ga content.The Seebeck coefficient increases with increasing Ga content. Among all the samples,Ba7.93Ga17.13Si28.72exhibits higher Seebeck coefficient than the others and reaches -135μV·K^-1 at 1000 K.The sample prepared by this method exhibits very high electrical conductivity,and reaches 1.95x 10^5 S·m^-1 for Ba8.01Ga16.61Si28.93 at room temperature.The thermal conductivity of all samples is almost temperature independent in the temperature range of 300-1000 K,indicating the behaviour of a typical metal.The maximum ZT value of 0.75 is obtained at 1000 K for the compound Ba7.93Ga17.13Si28.72.

Combined Langmuir-magnetic probe measurements of type-Ⅰ ELMy filaments in the EAST tokamak

Detailed investigations on the filamentary structures associated with the type-I edge-localized modes（ELMs） should be helpful for protecting the materials of a plasma-facing wall on a future large device.Related experiments have been carefully conducted in the Experimental Advanced Superconducting Tokamak（EAST） using combined Langmuir-magnetic probes.The experimental results indicate that the radially outward velocity of type-I ELMy filaments can be up to 1.7 kms^（-1） in the far scrape-off layer（SOL） region.It is remarkable that the electron temperature of these filaments is detected to be ~50eV,corresponding to a fraction of 1/6 to the temperature near the pedestal top,while the density ~3×10^（19）m^（-3） of these filaments could be approximate to the line-averaged density.In addition,associated magnetic fluctuations have been clearly observed at the same time,which show good agreement with the density perturbations.A localized current on the order of ~100kA could be estimated within the filaments.

De novo design of highly efficient type-Ⅰphotosensitizer based onπ-conjugated oligomer for photodynamic eradication of multidrug-resistant bacterial infections

Traditional photosensitizers show limited singlet oxygen generation in hypoxic infection lesions,which greatly suppress their performance in antibacterial therapy.Meanwhile,there still is lack of feasible design strategy for developing hypoxia-overcoming photosensitizers agents.Herein,radical generation ofπ-conjugated small molecules is efficiently manipulated by an individual selenium(Se)substituent.With this strategy,the first proof-of-concept study of a Se-anchored oligo(thienyl ethynylene)(OT-Se)with high-performance superoxide radical(O_(2)^(·-))and hydroxyl radical(·OH)generation capability is present,and achieves efficient antibacterial activities towards the clinically extracted multidrug-resistant bacteria methicillin-resistant S.aureus(MRSA)and carbapenem-resistant E.coli(CREC)at sub-micromolar concentration under a low white light irradiation(30 mW/cm^(2)).The water-dispersible OT-Se shows a good bacteria-anchoring capability,biocompatibility,and complete elimination of multidrug-resistant bacteria wound infection in vivo.This work offers a strategy to boost type-I photodynamic therapy(PDT)performance for efficient antibacterial treatments,advancing the development of antibacterial agents.

甲烷水合物(可燃冰)结构-I的分子间势能的量子化学研究

采用Hartree-Fork,4种DFT(BLYP,B3LYP,MPW1PW91,SVWN5)和MP2方法研究了甲烷水合物结构-Ⅰ的氢键和范德华能.甲烷分子取HF/6-31G(d,p)优化构型,水分子选用ST2模型.水分子间的氢键能Ebb(l)和甲烷-水分子间的范德华能Evdw(l)作为正十二面体边长l的函数,用HF/6-31G(d,p)和4种DFT方法做计算,保持水分子和甲烷分子的构型不变,在几个关键点上选用MP2方法做了计算.计算中选用6-31G(d,p)基组,分别用完全平衡校正和不完全校正法进行校正,这两种方法给出了基组重叠误差(BSSE)的上限和下限.DFT/B3LYP方法计算的氧-氧距离Ro-o=0.280 nm和碳-氧距离Rc-o=0.392 nm最接近于实验值0.282 nm和0.395 nm.所有计算方法(HF,DFT,MP2)都表明,甲烷水合物结构-Ⅰ是一个由超强氢键(30～36 kJ/mol)组成的稳定结构,其氢键能远大于水分子二聚体和冰Ⅰ4晶格中的氢键能((-22.6±2.9)kJ/mol和(-21.7±0.5)kJ/mol).这些数据为气体水合物的Lennand-Jones和Kihara势能函数提供了基本参数,可用于气体水合物的分子动力学模拟.

On scaling invariance and type-Ⅰ singularities for the compressible Navier-Stokes equations

We find a new scaling invariance of the barotropic compressible Navier-Stokes equations. Then it is shown that type-Ⅰ singularities of solutions with■ can never happen at time T for all adiabatic number γ 1. Here κ > 0 does not depend on the initial data.This is achieved by proving the regularity of solutions under■ This new scaling invariance also motivates us to construct an explicit type-Ⅱ blowup solution for γ > 1.

The Scorpion Venom Peptide Smp76 Inhibits Viral Infection by Regulating Type-Ⅰ Interferon Response

Dengue virus(DENV) and Zika virus(ZIKV) have spread throughout many countries in the developing world and infect millions of people every year, causing severe harm to human health and the economy. Unfortunately, there are few effective vaccines and therapies available against these viruses. Therefore, the discovery of new antiviral agents is critical.Herein, a scorpion venom peptide(Smp76) characterized from Scorpio maurus palmatus was successfully expressed and purified in Escherichia coli BL21(DE3). The recombinant Smp76(rSmp76) was found to effectively inhibit DENV and ZIKV infections in a dose-dependent manner in both cultured cell lines and primary mouse macrophages. Interestingly,rSmp76 did not inactivate the viral particles directly but suppressed the established viral infection, similar to the effect of interferon(IFN)-b. Mechanistically, rSmp76 was revealed to upregulate the expression of IFN-b by activating interferon regulatory transcription factor 3(IRF3) phosphorylation, enhancing the type-Ⅰ IFN response and inhibiting viral infection.This mechanism is significantly different from traditional virucidal antimicrobial peptides(AMPs). Overall, the scorpion venom peptide Smp76 is a potential new antiviral agent with a unique mechanism involving type-Ⅰ IFN responses,demonstrating that natural AMPs can enhance immunity by functioning as immunomodulators.

Band alignment of type-Ⅰ SnS_(2)/Bi_(2)Se_(3) and type-Ⅱ SnS_(2)/Bi_(2)Te_(3) van der Waals heterostructures for highly enhanced photoelectric responses

Heterostructures based on new advanced materials offer a cornerstone for future optoelectronic devices with improved photoelectric performance.Band alignment is crucial for understanding the mechanism of charge carrier transportation and interface dynamics in heterostructures.Herein,we grew SnS_(2)/Bi_(2)X_(3)(X=Se,Te)van der Waals heterostructures by combining physical vapor deposition with chemical vapor deposition.The band alignment,measured by high-resolution X-ray photoelectron spectroscopy,suggested the successful design of type-Ⅰ SnS_(2)/Bi_(2)Te_(3) and type-Ⅱ SnS_(2)/Bi_(2)Te_(3) heterostructures.The SnS_(2)/Bi_(2)X_(3) heterostructure greatly improved the photoelectric response of a photoelectrochemical-type photodetector.The photocurrent densities in the type-Ⅰ SnS_(2)/Bi_(2)Te_(3) and type-Ⅱ SnS_(2)/Bi_(2)Te_(3) heterostructure-based devices were more than one order of magnitude higher than those of SnS_(2),Bi_(2)Te_(3),and Bi_(2)Te_(3).The improved photoelectric properties of the SnS_(2)/Bi_(2)X_(3) heterostructures can be explained as follows:(i)the photoexcited electrons and holes are effectively separated in the heterostructures;(ii)the charge-transfer efficiency and carrier density at the interface between the SnS_(2)/Bi_(2)X_(3) heterostructures and the electrolyte are greatly improved;(iii)the formed heterostructures expand the light absorption range.The photoelectric performance was further enhanced by efficient light trapping in the upright SnS_(2).The photoelectric response is higher in the type-Ⅰ SnS_(2)/Bi_(2)Te_(3) heterostructure than in the type-Ⅱ SnS_(2)/Bi_(2)Te_(3) heterostructure due to more efficient charge transportation at the type-Ⅰ SnS_(2)/Bi_(2)Te_(3) heterostructure/electrolyte interface.These results suggest that suitable type-Ⅰ and type-Ⅱ heterostructures can be developed for high-performance photodetectors and other optoelectronic devices.

Lepton-number-violating decays of singly-charged Higgs bosons in the type-(Ⅰ+Ⅱ) seesaw model

The lepton-number-violating decays of singly-charged Higgs bosons H^± are investigated in the minimal type-（ Ⅰ＋Ⅱ ） seesaw model with one SU（2）L Higgs triplet △ and one heavy Majorana neutrino N1 at the TeV scale. We find that the branching ratios B（H^＋ → 1α^＋υ^-） （for α = e,μ,τ） depend not only on the mass and mixing parameters of three light neutrinos υi （for i = 1, 2, 3） but also on those of N1. Assuming that the mass of N1 lies in the range of 200 GeV to 1 TeV, we figure out the generous interference bands for the contributions of υi and N1 to B（H^＋→ 1α^＋υ^-）. We illustrate some salient features of such interference effects by considering three typical mass patterns of υi, and show that the relevant Majorana CP-violating phases can affect the magnitudes of B（H^＋→ 1α^＋υ^-）） in this parameter region.

Ⅰ-型锗基笼形物—极有希望的热电材料

对Ⅰ-型锗基笼形物的制备、晶体结构特别是热电性能等研究现状做了综述。Ⅰ-型锗基笼形物半导体是具有“声子玻璃、电子晶体”特性的热电材料。它具有笼子状的晶体结构,这种独特的框架结构决定了其具有良好的电性能,而通过填充合适的碱土金属或稀土金属原子到其笼子状的空隙中则可以大大降低体系的热导率,因而是很具希望的热电材料体系。要进一步提高该体系的热电性能,必须在优化填充原子的同时优化框架原子。

熔体旋甩工艺对Zn掺杂Ⅰ-型Ba_8Ga_(12)Zn_2Ge_(32)笼合物微结构及热电性能的影响

采用新颖的熔体旋甩(MS)结合放电等离子烧结(SPS)技术制备了单相Zn掺杂的Ⅰ-型Ba8Ga12Zn2Ge32笼合物,研究了熔体旋甩工艺对其微结构以及热电性能的影响.结果表明,MS得到的薄带自由面主要由300nm—1μm的小立方体单晶组成,薄带经SPS烧结后得到了具有大量层状精细结构的致密块体.与熔融+SPS工艺制备的试样相比,熔融+MS+SPS制备的Ba8Ga12Zn2Ge32笼合物室温载流子浓度增加而迁移率降低,在测试温度范围内,试样的电导率略有下降,Seebeck系数增加,热导率和晶格热导率显著降低,900K时其晶格热导率从1.06W/mK降低至0.42W/mK.熔融+MS+SPS制备的Ba8Ga12Zn2Ge32笼合物试样在900K时其最大ZT值达到0.90,与熔融+SPS试样相比提高了75%.

拓扑向量空间中Gteaux可微多目标优化的充分性和对偶性(英文)

本文研究了拓扑向量空间中的多目标优化问题的充分性和对偶性.对拓扑向量空间中Gteaux可微映射,引进了几类广义type-Ⅰ映射的概念并在这些广义type-Ⅰ假设下证明了一些最优性充分条件和对偶定理.

飞秒激光在柔性PDMS中直写光波导器件研究进展

飞秒激光直写技术由于其超短脉冲持续时间、超高峰值功率、高制造精度和效率,已被广泛应用在透明硬碎材料中3D光波导器件的直写制备。近年来,通过飞秒激光在柔性聚二甲基硅氧烷(PDMS)中直写光波导器件越来越受到人们的关注。本综述从3个方面介绍飞秒激光直写技术在柔性PDMS中直写Type-Ⅰ型光波导器件的最新研究进展,包括:飞秒激光直写不同类型光波导的基本原理;近5年来飞秒激光在柔性PDMS中直写Type-Ⅰ型光波导所涉及的材料设计、直写原理和工艺;基于飞秒激光直写柔性PDMS光波导器件在衍射光栅和耳蜗内窥镜的应用研究进展。最后,对该领域研究进展进行总结、分析、归纳,并展望该领域未来研究、应用和发展方向。

Influence of serum adiponectin level and SNP +45 polymorphism of adiponectin gene on myocardial fibrosis

Adiponectin plays an important role in the development of hypertension, atherosclerosis, and cardio- myocyte hypertrophy, but very little was known about the influence of serum adiponectin or the adiponectin gene polymorphism on myocardial fibrosis. Our study investigates the influence of the SNP ＋45 polymorphism of the adi- ponectin gene and serum levels of adiponectin on myocardial fibrosis in patients with essential hypertension. A case-control study was conducted on 165 hypertensive patients and 126 normotensive healthy controls. The geno- types of adiponectin gene polymorphisms were detected by the polymerase chain reaction （PCR） method. Serum concentrations of procollagen were measured by a double antibody sandwich enzyme-linked immunosorbent assay （ELISA） in all subjects. The integrated backscatter score （IBS） was measured in the left ventricular myocardium using echocardiography. The serum levels of adiponectin in hypertensive patients were significantly lower than those in the normal control group （（2.69±1.0） μg/ml vs. （4.21±2.89） μg/ml, respectively, P〈0.001）. The serum levels of type-Ⅰ procoilagen carboxyl end peptide （PiCP） and type-Ⅲprocollagen ammonia cardinal extremity peptide （PIIINP） in the hypertension group were significantly higher than those in the control group. In the hypertension group, serum levels of adiponectin were significantly and negatively related to the average acoustic intensity and corrected acoustic intensity of the myocardium （t=0.46 and 0.61, respectively, P〈0.05 for both）. The serum levels of PICP and PIIINP were sig- nificantly different among the three genotypes of SNP ＋45 （P〈0.01）. Logistic regression analyses showed that sex and genotype （GG＋GT） were the major risk factors of myocardial fibrosis in hypertensive patients （OR=5.343 and 3.278, respectively, P〈0.05）. These data suggest that lower levels of adiponectin and SNP ＋45 polymorphism of the adi- ponectin gene are likely to play an important role in myocardial fibrosis in hypertensive patients.

Effect of type I collagen on the adhesion, proliferation, and osteoblastic gene expression of bone marrow-derived mesenchymal stem cells

Objective: To investigate the effects of porous poly lactide-co-glycolide (PLGA) modified by type I collagen on the adhesion, proliferation, and differentiation of rabbit marrow-derived mesenchymal stem cells (MSCs). Methods: The third generation MSCs isolated from mature rabbits by density gradient centrifugation were cultured at different initial concentrations on 0.3 cm×1.2 cm×2.0 cm 3-D porous PLGA coated by type I collagen in RPMI 1640 containing 10% fetal calf serum, while cultured on PLGA without type I collagen as control. The cells adhesive and proliferative behavior at 7, 14, and 21 days after inoculation was assessed by determining the incorporation rate of [3H]-TdR. In order to examine MSCs differentiation, the expression of osteoblasts marker genes, osteocalcin (OCN), alkaline phosphatase (ALP), osteopontin (OPN) mRNA, were evaluated by reverse transcription-polymerase chain reaction (RT-PCR), and further more, the cell morphology at 21 days was also observed by scanning electron microscope (SEM). Results: Type I collagen promoted cell adhesion on PLGA. The valve was significantly higher than controls (6 h, 2144 cpm±141cpm vs. 1797 cpm±118 cpm, P=0.017; 8 h, 2311 cpm±113 cpm vs. 1891 cpm±103 cpm, P=0.01). The cells which cultured on PLGA coated with type I collagen showed significantly higher cell proliferation than controls on the 7th day (1021 cpm±159 cpm vs. 451 cpm±67 cpm, P=0.002), the 14th day (1472 cpm±82 cpm vs. 583 cpm±67 cpm, P<0.001) and 21th day (1728 cpm±78 cpm vs. 632 cpm±55 cpm, P<0.001). Osteoblasts markers, OCN, ALP, OPN mRNA, were all detected on PLGA coated by type I collagen on the 21th day, but OCN, OPN mRNA could not be found in controls. Spindle and polygonal cells well distributed on the polymer coated by type I collagen while cylindric or round cells in controls. Conclusions: Type I collagen is effective in promoting the adhesion, proliferation and differentiation of MSCs on PLGA.

TWO POSSIBLE ACCELERATION MECHANISMS IN COMET TAIL

The large accelerations of plasma were observed early in type-Ⅰ comet tail. The accelerations can reach 300 cm/S^2. Recently, the direct measurements for comet G-Z show that the energy of particles reaches 2×10~5 eV. It is much higher than the initial

High-throughput transcriptomic profiling of mRNAs and lncRNAs in the dermatomyositis muscle by RNA sequencing

Background:Dermatomyositis(DM)is an idiopathic inflammatory myopathy(IIM).In this study,we investigated the mRNAs and long noncoding RNAs(lncRNAs)in muscle biopsy specimens that are differentially expressed among patients with DM,patients with other IIM,and healthy controls(HCs).Methods:In total,three patients with DM,10 patients with other IIM,and three HCs were included.Muscle biopsy specimens were collected for RNA-sequencing.Gene ontology and pathway analyses were employed to characterize the biological processes and signaling pathways.Results:Compared with HCs,372 differentially expressed mRNAs were identified within the DM group,including 275 upregulated and 97 downregulated ones.Moreover,692 differentially expressed lncRNAs were identified in the DM group compared with HCs,of which 407 were upregulated and 285 were downregulated.Bioinformatic analysis indicated that the type-Ⅰ interferon signaling pathway and biological processes of innate immunity were significantly influenced by the differentially expressed mRNAs.Notably,11 of the top 20 upregulated mRNAs were involved in the type-Ⅰ interferon signaling pathway.Reverse transcription polymerase chain reaction analysis verified the RNA-sequencing data.Target gene prediction analysis suggested that the lncRNA NONHSAG043573.2 potentially targeting transporter associated with antigen processing 1,a key regulator of interferon signaling genes,might play an important role in the pathogenesis of DM.Conclusions:Our study assessed the transcriptomic profiles of differentially expressed mRNAs and lncRNAs in the DM muscle tissue and revealed that the upregulated mRNAs are significantly involved in the innate immune response and the type-Ⅰ interferon signaling pathway,which might play important roles in the pathogenesis of DM.