Short, intense laser pulses can be used to access the transition regime between classical and quantum optical responses in dielectrics. In this regime, the relative roles of inter- and intraband ...light-driven electronic transitions remain uncertain. We applied attosecond transient absorption spectroscopy to investigate the interaction between polycrystalline diamond and a few-femtosecond infrared pulse with intensity below the critical intensity of optical breakdown. Ab initio time-dependent density functional theory calculations, in tandem with a two-band parabolic model, accounted for the experimental results in the framework of the dynamical Franz-Keldysh effect and identified infrared induction of intraband currents as the main physical mechanism responsible for the observations.
Optical cavities confine light on a small region in space, which can result in a strong coupling of light with materials inside the cavity. This gives rise to new states where quantum fluctuations of ...light and matter can alter the properties of the material altogether. Here we demonstrate, based on first-principles calculations, that such light–matter coupling induces a change of the collective phase from quantum paraelectric to ferroelectric in the SrTiO3 ground state, which has thus far only been achieved in out-of-equilibrium strongly excited conditions X. Li et al., Science 364, 1079–1082 (2019) and T. F. Nova, A. S. Disa, M. Fechner, A. Cavalleri, Science 364, 1075–1079 (2019). This is a light–matter hybrid ground state which can only exist because of the coupling to the vacuum fluctuations of light, a photo ground state. The phase transition is accompanied by changes in the crystal structure, showing that fundamental ground state properties of materials can be controlled via strong light–matter coupling. Such a control of quantum states enables the tailoring of materials properties or even the design of novel materials purely by exposing them to confined light.
Effect of ZrO2 phases on the formation of acetaldehyde and ethyl acetate from ethanol over Cu/ZrO2 catalysts. Display omitted
•Cu catalysts supported on am-, m-, and t-ZrO2 for selective ethanol ...conversion.•Cu/m-ZrO2 catalyst shows a high selectivity to ethyl acetate.•The high rate of ethyl acetate is defined by oxygen mobility from bulk ZrO2 to Cu.•A high rate for acetaldehyde formation is observed for Cu/t-ZrO2 catalyst.
The effect of amorphous (am-), monoclinic (m-), and tetragonal (t-) ZrO2 phase on the physicochemical and catalytic properties of supported Cu catalysts for ethanol conversion was studied. The electronic parameters of Cu/ZrO2 were determined by in situ XAS, and the surface properties of Cu/ZrO2 were defined by XPS and DRIFTS of CO-adsorbed. The results demonstrated that the kind of ZrO2 phase plays a key role in the determination of structure and catalytic properties of Cu/ZrO2 catalysts predetermined by the interface at Cu/ZrO2. The electron transfer between support and Cu surface, caused by the oxygen vacancies at m-ZrO2 and am-ZrO2, is responsible for the active sites for acetaldehyde and ethyl acetate formation. The highest selectivity to ethyl acetate for Cu/m-ZrO2 catalyst up to 513K was caused by the optimal ratio of Cu0/Cu+ species and the high density of basic sites (O2−) associated with the oxygen mobility from the bulk m-ZrO2.
Wnt5a is a representative ligand that activates the β‐catenin‐independent pathways. Because the β‐catenin‐independent pathway includes multiple signalling cascades in addition to the planar cell ...polarity and Ca2+ pathway, Wnt5a regulates a variety of cellular functions, such as proliferation, differentiation, migration, adhesion and polarity. Consistent with the multiple functions of Wnt5a signalling, Wnt5a knockout mice show various phenotypes, including an inability to extend the embryonic anterior–posterior and proximal–distal axes in outgrowth tissues. Thus, many important roles of Wnt5a in developmental processes have been demonstrated. Moreover, recent reports suggest that the postnatal abnormalities in the Wnt5a signalling are involved in various diseases, such as cancer, inflammatory diseases and metabolic disorders. Therefore, Wnt5a and its signalling pathways could be important targets for the diagnosis and therapy for human diseases.
Panton-Valentine leukocidin (PVL) gene (lukS/F-PV)-positive community-acquired methicillin-resistant Staphylococcus aureus (MRSA), particularly the USA300 clone, is a health concern worldwide. ...Recently, community-acquired MRSA clones have been found to spread and persist in hospital settings. We aimed to investigate the prevalence and molecular epidemiologic features of lukS/F-PV–positive MRSA in Japanese hospitals.
A total of 3433 MRSA isolated from nine hospitals in 2011–2015 were assessed. Molecular epidemiologic analysis performed by staphylococcal cassette chromosome mec typing, PVL typing, arginine catabolic mobile element typing, detection of virulence determinants, multilocus sequence typing, pulsed-field gel electrophoresis and antimicrobial susceptibility testing.
The detection rate of lukS/F-PV was increased annually from 0.6% (5/817) in 2011 to 3.1% (17/544) in 2015. Molecular epidemiologic analysis for 64 lukS/F-PV–positive MRSA isolates revealed that 42 isolates (65.6%) were the USA300 clone. Resistance rates of levofloxacin and gentamicin among lukS/F-PV–positive isolates increased annually as a result of increased prevalence of the multidrug-resistant USA300 clone.
This is the first report on dissemination of the USA300 clone and PVL-positive MRSA in multiple Japanese hospitals. Our data strongly suggest that the USA300 clone may become epidemic in Japanese hospitals.
The aim of this study was to evaluate the effect of hoof trimming on overall limb movements by comparing the changes in 8 limb joint angles before and after one week of hoof trimming. Seventeen ...Holstein-Friesian dairy cows that were able to move freely and had no history of hoof diseases were included in the study. The cows were walked on a rubber mat with a high friction coefficient (HFM) and a low friction coefficient by the spraying of sodium polyacrylate (LFM). A high-speed camera was set to 200 fps on the image analysis software, and the images of the cows that were given 15 reflective markers on their right side were captured while walking on the test mat. The tests were conducted before and after one week of hoof trimming, and the cows were trimmed by the functional hoof trimming method. With image analysis software, video clips of walking cows were confirmed visually and tracked during one gait cycle by each reflective marker attached to the hoof of the forelimb and hindlimb, after which the stance phase and swing phase were identified. The durations of the stance phase and swing phase of the forelimb and hindlimb, respectively, and the maximum, minimum, and range of motion (ROM) values of the 8 joint angles, shoulder joint, elbow joint, carpus joint, forelimb fetlock joint, hip joint, stifle joint, hock joint and hindlimb fetlock joint during one gait cycle were included in the analysis. The maximum and minimum angles of the hip and stifle joints were narrower after hoof trimming than before, although the ROM did not change and was clearer for HFM than for LFM. It was thought that the flexion of the proximal hindlimb would progress smoothly during walking after trimming.
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