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Nickel-based complex oxides have served as a playground for decades in the quest for a copper-oxide analog of the high-temperature superconductivity. They may provide clues towards understanding the mechanism and an alternative route for high-temperature superconductors. The recent discovery of superconductivity in the infinite-layer nickelate thin films has fulfilled this pursuit. However, material synthesis remains challenging, direct demonstration of perfect diamagnetism is still missing, and understanding of the role of the interface and bulk to the superconducting properties is still lacking. Here, we show high-quality Nd0.8Sr0.2NiO2 thin films with different thicknesses and demonstrate the interface and strain effects on the electrical, magnetic and optical properties. Perfect diamagnetism is achieved, confirming the occurrence of superconductivity in the films. Unlike the thick films in which the normal-state Hall-coefficient changes signs as the temperature decreases, the Hall-coefficient of films thinner than 5.5 nm remains negative, suggesting a thickness-driven band structure modification. Moreover, X-ray absorption spectroscopy reveals the Ni-O hybridization nature in doped infinite-layer nickelates, and the hybridization is enhanced as the thickness decreases. Consistent with band structure calculations on the nickelate/SrTiO3 heterostructure, the interface and strain effect induce a dominating electron-like band in the ultrathin film, thus causing the sign-change of the Hall-coefficient. Nickelate superconductors attract enormous attention in the field of high-temperature superconductivity. Here the authors report observation of perfect diamagnetism and interfacial effect on the electronic structures in infinite layer Nd0.8Sr0.2NiO2 superconductors. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To summarize the current practice and potential strategy in diagnosing coronavirus disease 2019 (COVID-19). MATERIALS AND METHODS: PubMed, Web of Science were systematically searched using terms including "COVID-19", "SARS-CoV-2" and "2019-nCoV". After removing duplicates, we then identified articles, letters and commentaries regarding diagnosing COVID-19. RESULTS: Here we summarized relatively mature diagnostic methods like nuclear acid test and computed tomography. Besides, new aspects regarding these detection methods like suitable specimens for nuclear acid test, possible use of 18F-FDG PET/CT were also reported. Especially, we also presented several novel techniques for diagnosing COVID-19 like lung ultrasound. CONCLUSIONS: Chinese Clinical Guidance for COVID-19 Pneumonia Diagnosis and Treatment (7th edition) by National Health Commission is recommended to follow as it provides detailed diagnostic procedures using currently available tools. We suggest clinicians further explore the saliva's utility as a specimen for nuclear acid test and the use of lung ultrasound. [ABSTRACT FROM AUTHOR]

Semiconductor compounds are widely used for photocatalytic hydrogen production applications, where photogenerated electron-hole pairs are exploited to induce catalysis. Recently, powders of a metallic oxide (Sr1−xNbO3, 0.033+δ and find that their bandgaps are ∼4.1 eV. Surprisingly, the carrier density of the conducting phase exceeds 1022 cm−3 and the carrier mobility is only 2.47 cm2 V−1 s−1. Contrary to earlier reports, the visible light absorption at 1.8 eV (∼688 nm) is due to the plasmon resonance, arising from the large carrier density. We propose that the hot electron and hole carriers excited via Landau damping (during the plasmon decay) are responsible for the photocatalytic property of this material under visible light irradiation. [ABSTRACT FROM AUTHOR]

SrTiO3 undergoes a cubic to tetragonal phase transition at Tc=105-110K, which can be described by a Brillouin zone corner Γ25 (111) soft phonon. Even though clear anomalies in specific heat, thermal expansion coefficient, and sound velocity have been observed, the correlation between phase transition and electronic transport properties in n-type doped SrTiO3 is still controversial. Here, we report phase transition induced electronic transport anomaly in temperature dependence of the temperature coefficient of resistance (TCR) consistently observed in a wide variety of SrTiO3-based systems by detailed transport measurements and first-principles calculations. The observed TCR anomaly, which can be well fitted with the electron-Γ25 soft phonon scattering around Tc, is found to be caused by anomalies in both mobility and carrier density, with the former taking the dominant role. Moreover, the magnitude of the anomaly is found to decrease with increasing carrier density. These findings demonstrate the role of the electron-Γ25 soft phonon scattering in the conduction mechanism in SrTiO3-based systems. [ABSTRACT FROM AUTHOR]

To determine the significance of miR—214 expression in ischemic post—conditioning. Sixty rats were grouped to establish animal models. Immuno— luminescence and chemical methods were used to detect oxidative stress indicators. Hemodynamics indexes were measured by carotid artery intubation, and ischemia and infarction areas by Evans blue and 2,3—5 triphenyltetrazolium chloride(TTC) staining. TargetScan was used for identification and luciferase assays for verification of target genes.miR—214 and hypoxia inducible factor 1, alpha subunit inhibitor (HIF1AN) were analyzed by real—time quantitative polymerase chain reaction. Ischemia reperfusion significantly decreased left ventricular systolic pressure, +dp/dtmax, and —dp/dtmax and increased left ventricular end—diastolic pressure; ischemic post—conditioning had contrasting effects. Compared to the sham group, the ischemic/reperfusion (IR) group showed increased creatine kinase isoenzyme (CK—MB) and malondialdehyde (MDA) in the myocardium and decreased SOD. miR—214 in the IR group was down—regulated, and HIF1AN, up—regulated. Compared with the IR group, the ischemia postconditioning (IPC) group showed decreased CK—MB and MDA in the myocardium and increased SOD. The proportion of infarction area to ischemia area in IPC group declined compared to IR group. miR—214 and HIF1AN in the IPC group showed significant up— and down—regulation, respectively. Ischemic postconditioning can improve myocardial function, reduce myocardial infarction area, and prevent the ischemia reperfusion injury. miR—214 may participate in the protective function of ischemic post—conditioning by down—regulating HIF1AN.

It is generally believed that the zinc metalloenzyme alkaline phosphatase is required to hydrolyze phosphorylated forms of vitamin B-6 prior to their use. To test this hypothesis, rats were fed a liquid diet containing either adequate or moderately low zinc during gestation and lactation. Zinc deficiency was produced in dams evidenced by significant reductions in zinc concentration of plasma (49%), liver (25%), and femur (24%), and plasma alkaline phosphatase activity (48%). Plasma pyridoxal-5'-phosphate (PLP), which significantly increased (61%) in these same rats, was negatively correlated (r = -0.74, P < 0.02) with plasma alkaline phosphatase activity. Maternal liver PLP concentration was unaffected by zinc status. The zinc and vitamin B-6 relationship seen in dams was less observable in offspring. Stimulation of erythrocyte alanine aminotransferase activity by exogenously added PLP in vitro tended to be higher in both moderately zinc-deficient mothers and their offspring, but the difference was not significant. Our results support the hypothesis that alkaline phosphatase activity is required for the hydrolysis of plasma PLP. Our results also suggest that zinc status as alkaline phosphatase activity should be defined in an individual if plasma PLP is to be used as an indicator of vitamin B-6 status.

Five compounds (1-5) were isolated from the leaves of Parthenocissus thomsonii collected in Henan. On the basis of chemical reaction and spectroscopic studies, 1, 2 and 3 were identified as friedelin, epifriedelanol and quercetin respectively.