Highlights • 27-OHC is a critical mediator of the detrimental effects on spatial learning memory in rats. • 27-OHC significantly increased the content of cholesterol in brain tissues. • 27-OHC ...significantly decreased in HMG-CR and LDLR expressions. • 27-OHC significantly increased in mRNA expressions of CYP46A1 and LXR-β. • 27-OHC significantly up-regulated expressions of LXR-α and ABCA1.
The formation and development of the southern Altaids is controversial with regard to its accretionary orogenesis and continental growth. The Altay-East Junggar orogenic collage of North Xinjiang, ...China, offers a special natural laboratory to resolve this puzzle. Three tectonic units were juxtaposed, roughly from North to South, in the study area. The northern part (Chinese Altay), composed of variably deformed and metamorphosed Paleozoic sedimentary, volcanic, and granitic rocks, is interpreted as a Japan-type island arc of Paleozoic to Carboniferous-Permian age. The central part (Erqis), which consists of ophiolitic melanges and coherent assemblages, is a Paleozoic accretionary complex. The southern part (East Junggar), characterized by imbricated ophiolitic melanges, Nb-enriched basalts, adakitic rocks and volcanic rocks, is regarded as a Devonian-Carboniferous intra-oceanic island arc with some Paleozoic ophiolites, superimposed by Permian arc volcanism. A plagiogranite from an imbricated ophiolitic melange (Armantai) in the East Junggar yields a new SHRIMP zircon age of 503 ± 7 Ma. Using published age constraints, we propose the presence of multiple subduction systems in this part of the Paloasian Ocean in the Paleozoic. The intraoceanic arcs became accreted to the southern active margin of the Siberian craton in the middle Carboniferous-Permian. During the long accretionary processes, in addition to large-scale southward-directed thrusting, large-scale, orogen-parallel, strike-slip movements (for example, Erqis fault) in the Permian translated fragments of these intraoceanic arcs and associated accretionary wedges. This new tectonic model has broad implications for the architecture and crustal growth of Central Asia and for other ancient orogens. PUBLICATION ABSTRACT
Oxygen vacancies (V
O
) are known to be common native defects in zinc oxide (ZnO) and to play important roles in many applications. Based on density functional theory, we present a study for the ...migration of oxygen vacancies in ultra-thin ZnO nanowires (NWs). We find that under equilibrium growth conditions V
O
has a higher formation energy (
E
f
) inside the wire than that at shallow sites and surface sites, with different geometric relaxations and structural reconstructions. The migration of V
O
has lower barriers in the NW than in the bulk and is found to be energetically favorable in the direction from the bulk to the surface. These results imply a higher concentration of V
O
at surface sites and also a relative ease of diffusion in the NW structure. Our results support the previous experimental observations and are important for the development of ZnO-based devices in photocatalysis and optoelectronics.
Oxygen vacancies (V
O
) are known to be common native defects in zinc oxide (ZnO) and to play important roles in many applications.
Insulin resistance (IR) is predominantly causal for type 2 diabetes mellitus (T2DM). To solve this problem, this study particularly determined the role of quercetin (Que) in controlling IR in T2DM ...mice. The T2DM mouse model was established, and given 20 mg/kg/d Que by gavage for 6 weeks, and the lentiviral vector that interfered with microRNA-92b-3p (miR-92b-3p) or early growth response 1 (EGR1) expression was injected into the tail vein of T2DM mice. Blood glucose homeostasis and histopathological changes in the pancreas were observed after the corresponding treatment. miR-92b-3p and EGR1 expressions were assessed in T2DM mice, as well as their interlink. In results we found that Que could improve IR and pancreatic histopathological changes in T2DM mice. Low miR-92b-3p and high EGR1 were expressed in T2DM mice, while Que could upregulate miR-92b-3p to target EGR1. Enhancing miR-92b-3p or reducing EGR1 could further improve IR and pancreatic histopathological changes in T2DM mice after Que administration. Nevertheless, silencing miR-92b-3p or overexpressing EGR1 contributed to the opposite results. We concluded that Que exerted anti-diabetic effects in T2DM mice by regulating the miR-92b-3p/EGR1 axis.
Pristine silica glass fiber is well known to become mechanically weaker when heat-treated in the presence of water vapor. However, the same fiber was found to become stronger if heat-treated while ...held under a sub-critical tensile stress at a temperature far below the glass transition temperature. The added strength of the stress-treated fiber was nearly equal to the applied tensile stress. This added strength was attributed to the formation of a compressive stress layer on the surface of the glass, created by a surface stress relaxation process that occurred while being held under the tensile stress. The presence of the surface compressive stress was confirmed by observing the bending of the fiber when 1) a tensile-stressed fiber was sliced and 2) a bending-stressed fiber was released from the stress. In the present paper we demonstrate that even though heat-treatment of a silica glass fiber in water vapor weakens the glass, a tensile stress application during the heat-treatment can increase the strength of silica glass fibers. Silica glass fibers with estimated strengths of ~7–8GPa were produced, exceeding that of other fibers previously reported to have a maximum strength of ~5.5GPa at room temperature in air. This new glass strengthening method does not require glass to be of a minimum thickness, as in tempering, or a glass containing alkali ions, as in ion-exchange.
•Silica glass fiber becomes stronger when heated while subjected to a tensile stress.•The fiber subjected to tensile stress acquires a surface residual compressive stress.•The residual stress is produced by surface stress relaxation promoted by water.
The increasing demands of energy storage require the significant improvement of current Li‐ion battery electrode materials and the development of advanced electrode materials. Thus, it is necessary ...to gain an in‐depth understanding of the reaction processes, degradation mechanism, and thermal decomposition mechanisms under realistic operation conditions. This understanding can be obtained by in situ/operando characterization techniques, which provide information on the structure evolution, redox mechanism, solid‐electrolyte interphase (SEI) formation, side reactions, and Li‐ion transport properties under operating conditions. Here, the recent developments in the in situ/operando techniques employed for the investigation of the structural stability, dynamic properties, chemical environment changes, and morphological evolution are described and summarized. The experimental approaches reviewed here include X‐ray, electron, neutron, optical, and scanning probes. The experimental methods and operating principles, especially the in situ cell designs, are described in detail. Representative studies of the in situ/operando techniques are summarized, and finally the major current challenges and future opportunities are discussed. Several important battery challenges are likely to benefit from these in situ/operando techniques, including the inhomogeneous reactions of high‐energy‐density cathodes, the development of safe and reversible Li metal plating, and the development of stable SEI.
Recent developments of the five important in situ/operando characterization categories for lithium battery research are summarized, including X‐ray, electron, neutron, optical, and scanning probe techniques. For each technique, the operating principles and in situ cell design are described in detail, including representative studies of typical electrode materials and related processes summarized in tables for easy comparison and cross reference.
Abstract
Objective To compare by meta-analysis the efficacy and adverse events of Hypericum perforatum L. (St. John's Wort), or its combinations, and placebo for menopausal women.
Design A systematic ...review and meta-analysis were carried out by searching in Pubmed, Cochrane Library, Embase and the Web of Science database.
Results Extracts of Hypericum perforatum L. and its combination with herbs were significantly superior to placebo (standard mean difference = −1.08; 95% confidence interval -1.38 to -0.77); extracts of Hypericum perforatum L. proved to be more effective than placebo in the treatment of menopause. Adverse events occurred in 53 (17.4%) patients on Hypericum perforatum L. preparations and 45 (15.4%) patients on placebo (relative risk = 1.16; 95% confidence interval 0.81-1.66).
Conclusion Extracts of Hypericum perforatum L. have possibly fewer side-effects than placebo for the treatment of menopausal women.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Understanding how fertilization practices affect Al fractions is important for the alleviation of soil acidification and the sequestration of soil organic C (SOC). Two selective extraction methods, ...high‐resolution 27Al nuclear magnetic resonance (NMR) spectroscopy and Fourier‐transform infrared spectroscopy (FTIR), were used to assess the transformation of Al fractions in Ferralic Cambisol soils under long‐term (22‐yr) treatment with chemical and/or organic fertilizers. The results showed that Al fractions were significantly (P < 0.05) altered by long‐term fertilization. Compared with chemical fertilization (N and N–P–K), organic fertilization (manure alone and N–P–K with manure) significantly (P < 0.05) increased amorphous Al and decreased exchangeable Al, while the addition of lime (N with lime and N–P–K with lime) significantly (P < 0.05) increased weakly organically bound Al and decreased exchangeable Al. Amorphous Al was significantly positively correlated with soil C (P < 0.01), indicating that amorphous Al could enhance soil C sequestration. In contrast, exchangeable Al was significantly negatively correlated with soil pH (P < 0.01), indicating that reducing the concentration of exchangeable Al could alleviate soil acidification. The 27Al NMR and FTIR spectroscopy results of soil colloids further confirmed the presence of amorphous Al as allophane and imogolite in soil colloids under no‐fertilization and organic‐fertilization treatments but not under chemical fertilization, suggesting that the enhancement of soil nanominerals by organic fertilization may be another new mechanism for alleviating soil acidification. Our results provide novel insight into how Al fractions and their coordinate states under long‐term fertilization enhance soil C sequestration while alleviating soil acidification.
In this paper, we report a high-power thulium (Tm)-doped superfluorescent fiber source (SFS) in the 2-μm spectral region. The SFS is based on double angle-cleaved facet operation and uses a simple ...single-stage geometry. The copropagating amplified spontaneous emission (ASE) yields a maximum output of 20.7 W at a center wavelength of 1,960.7 nm, with a full width at half maximum (FWHM) of ~45 nm. The counterpropagating ASE yields a maximum output of 25.2 W at a center wavelength of 1,948.2 nm, with a FWHM of ~50 nm. The maximum combined output of the SFS is as much as 45.9 W, which corresponds to a slope efficiency of 38.9 %. In addition, a model of the ~2 μm SFS in Tm-doped silica fibers pumped at ~790 nm is developed, and the influence of fiber length and end-facet reflectivity on the ASE output performance and the parasitic lasing threshold are studied numerically.
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