287 research outputs found
Comparative Analysis on Main Material index of China and International Composite Girder Bridge with Corrugated Steel Web
Prestressed Concrete girder bridge with corrugated steel web is type of girder bridge that evolve rapidly in recent year, its excellent mechanical properties is getting more and more recognition by majority of the bridge engineers. This article investigate the case study of constructed girder bridge with corrugated steel webs in China, analyze and give comment based on their construction design, technology and etc. With the data of constructed girder bridge with corrugated steel webs in Japan, comparative analysis of the main material index of China and Japan girder bridge with corrugated steel webs was compared, the material index function was developed to ease the estimation of related construction
Multi-Fields Modulation of Physical Properties of Oxide Thin Films
Oxide thin films exhibit versatile physical properties such as magnetism,
ferroelectricity, piezoelectricity, metal-insulator transition (MIT),
multiferroicity, colossal magnetoresistivity, switchable resistivity, etc. More
importantly, the exhibited multifunctionality could be tuned by various
external fields, which has enabled demonstration of novel electronic devices.
In this article, recent studies of the multi-fields modulation of physical
properties in oxide thin films have been reviewed. Some of the key issues and
prospects about this field are also addressed.Comment: review article, 56 pages, 18 figure
Pharmacokinetic Comparison To Determine the Mechanisms Underlying the Differential Efficacies of Cationic Diamidines against First- and Second-Stage Human African Trypanosomiasis
This is the published version.Human African trypanosomiasis (HAT), a neglected tropical disease, is fatal without treatment. Pentamidine, a cationic diamidine, has been used to treat first-stage (hemolymphatic) HAT since the 1940s, but it is ineffective against second-stage (meningoencephalitic, or central nervous system [CNS]) infection. Novel diamidines (DB75, DB820, and DB829) have shown promising efficacy in both mouse and monkey models of first-stage HAT. However, only DB829 cured animals with second-stage infection. In this study, we aimed to determine the mechanisms underlying the differential efficacies of these diamidines against HAT by conducting a comprehensive pharmacokinetic characterization. This included the determination of metabolic stability in liver microsomes, permeability across MDCK and MDR1-MDCK cell monolayers, interaction with the efflux transporter MDR1 (P-glycoprotein 1 or P-gp), drug binding in plasma and brain, and plasma and brain concentration-time profiles after a single dose in mice. The results showed that DB829, an azadiamidine, had the highest systemic exposure and brain-to-plasma ratio, whereas pentamidine and DB75 had the lowest. None of these diamidines was a P-gp substrate, and the binding of each to plasma proteins and brain differed greatly. The brain-to-plasma ratio best predicted the relative efficacies of these diamidines in mice with second-stage infection. In conclusion, pharmacokinetics and CNS penetration influenced the in vivo efficacies of cationic diamidines against first- and second-stage HAT and should be considered when developing CNS-active antitrypanosomal diamidines
Efficient induction of CD25- iTreg by co-immunization requires strongly antigenic epitopes for T cells
Background: We previously showed that co-immunization with a protein antigen and a DNA vaccine coding for the same antigen induces CD40(low) IL-10(high) tolerogenic DCs, which in turn stimulates the expansion of antigenspecific CD4(+)CD25(-)Foxp3(+) regulatory T cells (CD25(-) iTreg). However, it was unclear how to choose the antigen
sequence to maximize tolerogenic antigen presentation and, consequently, CD25(-) iTreg induction. Results: In the present study, we demonstrated the requirement of highly antigenic epitopes for CD25(-) iTreg
induction. Firstly, we showed that the induction of CD25(-) iTreg by tolerogenic DC can be blocked by anti-MHC-II antibody. Next, both the number and the suppressive activity of CD25(-) iTreg correlated positively with the overt antigenicity of an epitope to activate T cells. Finally, in a mouse model of dermatitis, highly antigenic epitopes derived from a flea allergen not only induced more CD25(-) iTreg, but also more effectively prevented allergenic reaction to the allergen than did weakly antigenic epitopes.
Conclusions: Our data thus indicate that efficient induction of CD25- iTreg requires highly antigenic peptide
epitopes. This finding suggests that highly antigenic epitopes should be used for efficient induction of CD25- iTreg
for clinical applications such as flea allergic dermatitis
PtdIns (3,4,5) P3 Recruitment of Myo10 Is Essential for Axon Development
Myosin X (Myo10) with pleckstrin homology (PH) domains is a motor protein acting in filopodium initiation and extension. However, its potential role has not been fully understood, especially in neuronal development. In the present study the preferential accumulation of Myo10 in axon tips has been revealed in primary culture of hippocampal neurons with the aid of immunofluorescence from anti-Myo10 antibody in combination with anti-Tuj1 antibody as specific marker. Knocking down Myo10 gene transcription impaired outgrowth of axon with loss of Tau-1-positive phenotype. Interestingly, inhibition of actin polymerization by cytochalasin D rescued the defect of axon outgrowth. Furthermore, ectopic expression of Myo10 with enhanced green fluorescence protein (EGFP) labeled Myo10 mutants induced multiple axon-like neurites in a motor-independent way. Mechanism studies demonstrated that the recruitment of Myo10 through its PH domain to phosphatidylinositol (3,4,5)-trisphosphate (PtdIns (3,4,5) P3) was essential for axon formation. In addition, in vivo studies confirmed that Myo10 was required for neuronal morphological transition during radial neuronal migration in the developmental neocortex
Quasiparticle characteristics of the weakly ferromagnetic Hund's metal MnSi
Hund's metals are multi-orbital systems with or electrons
exhibiting both itinerant character and local moments, and they feature
Kondo-like screenings of local orbital and spin moments, with suppressed
coherence temperature driven by Hund's coupling . They often exhibit
magnetic order at low temperature, but how the interaction between the
Kondo-like screening and long-range magnetic order is manifested in the
quasiparticle spectrum remains an open question. Here we present spectroscopic
signature of such interaction in a Hund's metal candidate MnSi exhibiting weak
ferromagnetism. Our photoemission measurements reveal renormalized
quasiparticle bands near the Fermi level with strong momentum dependence: the
ferromagnetism manifests through possibly exchange-split bands (Q1) below
, while the spin/orbital screenings lead to gradual development of
quasiparticles (Q2) upon cooling. Our results demonstrate how the
characteristic spin/orbital coherence in a Hund's metal could coexist and
compete with the magnetic order to form a weak itinerant ferromagnet, via
quasiparticle bands that are well separated in momentum space and exhibit
distinct temperature dependence. Our results imply that the competition between
the spin/orbital screening and the magnetic order in a Hund's metal bears
intriguing similarity to the Kondo lattice systems.Comment: accepted by PR
Quasi-Two-Dimensional Fermi Surface and Heavy Quasiparticles in CeRh2As2
The recent discovery of multiple superconducting phases in CeRh2As2 has
attracted considerable interest. These rich phases are thought to be related to
the locally noncentrosymmetric crystal structure, although the possible role of
a quadrupole density wave preceding the superconductivity remains an open
question. While measurements of physical properties imply that the Ce 4f
electrons could play an essential role, the momentum-resolved electronic
structure remains hitherto unreported, hindering an in-depth understanding of
the underlying physics. Here, we report a high-resolution angle-resolved
photoemission study of CeRh2As2. Our results reveal fine splittings of
conduction bands, which are directly related to the locally noncentrosymmetric
structure, as well as a quasi-two-dimensional Fermi surface, implying weak
interlayer hopping and possible nesting instabilities. Our experiments also
uncover the fine structures and pronounced temperature evolution of the Kondo
peak, demonstrating strong Kondo effect facilitated by excited crystal electric
field states. Our results unveil the salient electronic features arising from
the interplay between the crystal structure and strong electron correlation,
providing spectroscopic insight for understanding the heavy fermion physics and
unconventional quadrupole density wave in this enigmatic compound
Improved electrochemical conversion of CO2 to multicarbon products by using molecular doping
The conversion of CO2 into desirable multicarbon products via the electrochemical reduction reaction holds promise to achieve a circular carbon economy. Here, we report a strategy in which we modify the surface of bimetallic silver-copper catalyst with aromatic heterocycles such as thiadiazole and triazole derivatives to increase the conversion of CO2 into hydrocarbon molecules. By combining operando Raman and X-ray absorption spectroscopy with electrocatalytic measurements and analysis of the reaction products, we identified that the electron withdrawing nature of functional groups orients the reaction pathway towards the production of C2+ species (ethanol and ethylene) and enhances the reaction rate on the surface of the catalyst by adjusting the electronic state of surface copper atoms. As a result, we achieve a high Faradaic efficiency for the C2+ formation of approximate to 80% and full-cell energy efficiency of 20.3% with a specific current density of 261.4 mA cm(-2) for C2+ products.
Strategies to systematically tune CO2 electroreduction to multicarbon products are of high interests. Here the authors report electron withdrawing functional group alters the reaction pathway towards C2+ products by adjusting the oxidation state of surface copper.D.V., K.Q., and H.L.W. acknowledge funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement no. 804320). L.L., D.V., and H.L.W acknowledge the use of TEM instrumentation provided by the Nation Facility ELECMI ICTS (`Division de Microscopia Electronica', Universidad de Cadiz, DME-UCA). L.L. acknowledges funding from the Andalusian regional government (FEDER-UCA-18-106613), the European Union's Horizon 2020 research and innovation program (grant agreement 823717-ESTEEM3), and the Spanish Ministerio de Economia y Competitividad (PID2019-107578GA-I00). K.Q. and Y.Z. acknowledge financial support from the China Postdoctoral Science Foundation (2018M633127) and the Natural Science Foundation of Guangdong Province (2018A030310602). J.L. acknowledge financial support from the National Natural Science Foundation of China (21808134). We thank Soleil Synchrotron and Andrea Zitolo for allocating beamtime at beamline Samba within the proposal 20200732
Electronic band reconstruction across the insulator-metal transition in colossal magnetoresistive EuCd2P2
While colossal magnetoresistance (CMR) in Eu-based compounds is often
associated with strong spin-carrier interactions, the underlying reconstruction
of the electronic bands is much less understood from spectroscopic experiments.
Here using angle-resolved photoemission, we directly observe an electronic band
reconstruction across the insulator-metal (and magnetic) transition in the
recently discovered CMR compound EuCd2P2. This transition is manifested by a
large magnetic band splitting associated with the magnetic order, as well as
unusual energy shifts of the valence bands: both the large ordered moment of Eu
and carrier localization in the paramagnetic phase are crucial. Our results
provide spectroscopic evidence for an electronic structure reconstruction
underlying the enormous CMR observed in EuCd2P2, which could be important for
understanding Eu-based CMR materials, as well as designing CMR materials based
on large-moment rare-earth magnets.Comment: 6 pages, 4 figure
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