Engineered inverse opal structured semiconductors for solar light-driven environmental catalysis.

Inverse opal (IO) macroporous semiconductor materials with unique physicochemical advantages have been widely used in solar-related environmental areas. In this minireview, we first summarize the synthetic methods of IO materials, emphasizing the two-step and three-step approaches, with the typical physicochemical properties being compared where applicable. We subsequently discuss the application of IO semiconductors (e.g., TiO2, ZnO, g-C3N4) in various photo-related environmental techniques, including photo- and photoelectro-catalytic organic pollutant degradation in water, optical sensors for environmental monitoring, and water disinfection. The engineering strategies of these hierarchical structures for optimizing the activities for different catalytic reactions are discussed, ranging from heterojunction construction, cocatalyst loading, and heteroatom doping, to surface defect construction. Structure-activity relationships are established correspondingly. With a systematic understanding of the unique properties and catalytic activities, this review is expected to orient the design and structure optimization of IO semiconductor materials for photo-related performance improvement in various environmental techniques. Finally, the challenges of emerging IO structured semiconductors and future development directions are proposed.

RETRACTED: TRIM21 deficiency confers protection from OGD/R-induced oxidative and inflammatory damage in cultured hippocampal neurons through regulation of the Keap1/Nrf2 pathway.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The authors have requested that this paper be retracted as they were unable to repeat some results reported in this paper under the same conditions. In Figure 1D, they found that TRIM21 siRNA-1 could not silence the expression of TIRM21. Therefore, the subsequent results were no longer reliable. The authors apologize for any inconvenience this retraction may cause for readers.

Structural and Chemical Transformations of Zinc Oxide Ultrathin Films on Pd(111) Surfaces.

Structural and chemical transformations of ultrathin oxide films on transition metals lie at the heart of many complex phenomena in heterogeneous catalysis, such as the strong metal-support interaction (SMSI). However, there is limited atomic-scale understanding of these transformations, especially for irreducible oxides such as ZnO. Here, by combining density functional theory calculations and surface science techniques, including scanning tunneling microscopy, X-ray photoelectron spectroscopy, high-resolution electron energy loss spectroscopy, and low-energy electron diffraction, we investigated the interfacial interaction of well-defined ultrathin ZnOxHy films on Pd(111) under varying gas-phase conditions [ultrahigh vacuum (UHV), 5 × 10-7 mbar of O2, and a D2/O2 mixture] to shed light on the SMSI effect of irreducible oxides. Sequential treatment of submonolayer zinc oxide films in a D2/O2 mixture (1:4) at 550 K evoked reversible structural transformations from a bilayer to a monolayer and further to a Pd-Zn near-surface alloy, demonstrating that zinc oxide, as an irreducible oxide, can spread on metal surfaces and show an SMSI-like behavior in the presence of hydrogen. A mixed canonical-grand canonical phase diagram was developed to bridge the gap between UHV conditions and true SMSI environments, revealing that, in addition to surface alloy formation, certain ZnOxHy films with stoichiometries that do not exist in bulk are stabilized by Pd in the presence of hydrogen. Based on the combined theoretical and experimental observations, we propose that SMSI metal nanoparticle encapsulation for irreducible oxide supports such as ZnO involves both surface (hydroxy)oxide and surface alloy formation, depending on the environmental conditions.

Localization and Stabilization of Photogenerated Electrons at TiO2 Nanoparticle Surface by Oxygen at Ambient Temperature.

Understanding the mechanism by which oxygen adsorption influences the separation behavior of charge carriers is important in photocatalytic removal of air pollutants. In this study, we performed steady-state surface photovoltage and surface photocurrent spectroscopy combined with an atmosphere control system to determine the effect of oxygen on the charge separation behavior at the surface of anatase TiO2 nanoparticles at ambient temperature. Results showed that photogenerated electrons were movable in N2 atmosphere but were localized in O2 atmosphere. O2 obviously enhanced the stabilization of the localized photogenerated electrons when the surface defects of TiO2 were fully occupied by adsorbed O2. Moreover, O2 adsorption increased the energy demand for exciting electrons from the valence band to localized surface defect states and reduced the density of band tail states. These findings suggest us that the effect of gaseous species on the mobility and stability of charge carriers should be considered to understand the photocatalytic degradation of air pollutants.

Variance of Serum Lipid Levels in Stroke Subtypes.

BACKGROUND: An increasing number of epidemiological studies have identified a close relationship between dyslipidemia and atherosclerotic stroke. Indeed, lipid metabolism is significantly different among the different ischemic stroke subtypes. There are few studies available regarding risk factors for specific subtypes of ischemic stroke, and in particular, there is little evidence about the role of dyslipidemia. The aim of this study is to determine the relationship between acute ischemic stroke subtype and serum lipid level. METHODS: The levels of serum lipid including TC, TG, LDL-C, HDL-C, apoA, apoB, apoE, and LP (a) were tested in 362 ischemic stroke patients and 181 healthy controls. Lipid levels were analyzed in stroke subtypes according to the TOAST classification. RESULTS: Levels of TC, TG, LDL-C, apoA, apoB, apoE, and LP (a) were significantly higher and HDL-C levels were significantly lower in the patient group relative to control. The TC/HDL-C ratio, TG/HDL-C ratio, and LDL-C/HDL-C ratio were remarkably higher in the patient group. The levels of TC, TG, LDL-C, apoA, apoB, apoE, and LP(a) were markedly higher and HDL-C was markedly lower in the large-artery atherosclerosis stroke subtype relative to the cardioembolism subtype. Compared with the small-vessel occlusion group, the level of LP(a), TC, and TC/HDL-C were strikingly higher in the cardioembolism group. The TC/HDL-C ratio was different among subgroups, with the large-artery atherosclerosis group exhibiting the highest value. For TC, TG, LDL-C, apoA, apoB, apoE, LP(a), TC/HDL-C, TG/HDL-C, and LDL-C/HDL-C levels a statistically significant difference was found between the large-artery atherosclerosis group and the small-vessel occlusion group. CONCLUSIONS: We found that LDL-C and TC levels may be independent predictors for the occurrence of large-artery atherosclerotic stroke.

Neuroprotective effect of Panax notoginseng plysaccharides against focal cerebral ischemia reperfusion injury in rats.

Our present study was conducted to investigate whether Panax notoginseng plysaccharides (PNPS) exerted a neuroprotective effect against focal cerebral ischemia/reperfusion (I/R) injury in rats. Before mice were subjected to middle cerebral artery occlusion (MCAO) for 2 h and reperfusion for 22 h, PNPS at the doses of 50, 100, and 200 mg/kg was administered once a day intragastrically for continuous 7 days. Oral administration of PNPS could significantly reduce the severity of neurological deficits, infarct volumes, cerebral edema, and neuronal death caused by MCAO in rats. Moreover, in the presence of PNPS, the Bcl-2/Bax ratio increased, but the level of cleaved caspase-3 reduced. Thus, these finding suggested that suppressing apoptosis through increasing Bcl-2/Bax ratio and evoking caspase-3 cascade should be potential mechanism by which PNPS exerts its neuroprotective function against focal cerebral I/R injury.