51 research outputs found
患者再現videoを利用したPBLテュートリアルの有用性に関する研究
研究科: 千葉大学大学院医学薬学府(先端医学薬学専攻)学位記番号: 千大院医薬博甲第医1338号博士(医学)千葉大学 = Chiba Universit
Synergistic Effects of Water and Oxygen Molecule Co-adsorption on (001) Surfaces of Tetragonal CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>: A First-Principles Study
The poor environmental stability
of organometallic halide perovskite
solar cells presents a big challenge for its commercialization, which
is mainly due to the degradation of perovskite materials in humid
air. The role played by water molecules has been extensively studied
in the degradation processes, where strong interactions between water
molecules and perovskite surfaces are found. Using first-principles
simulations, we find that oxygen molecules also have strong interactions
with (001) surfaces of tetragonal CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> through the formation of a chemical Pb–O bond on the
PbI<sub>2</sub>-terminated surface and a hydrogen bond on the CH<sub>3</sub>NH<sub>3</sub>I-terminated surface. The adsorbed oxygen molecules
introduce empty states near the Fermi level of the surfaces, which
can facilitate charge transfer between the surface and oxygen molecules.
Furthermore, when an oxygen molecule is located atop a Pb atom on
PbI<sub>2</sub>-terminated surface, the calculated adsorption energies
indicate that the surface is more attractive to water molecules, making
the surface even more sensitive to humidity. These findings reveal
that oxygen molecules also play an important role in the initial stage
of the degradation of perovskite materials
Dependence of Plasmonic Properties on Electron Densities for Various Coupled Au Nanostructures
Noble metallic nanostructures have
great potential in optical sensing
application in visible and near-infrared frequencies. Their plasmonic
properties can be manipulated by <i>in situ</i> controlling
their electron densities for isolated nanostructures. However, the
effect of charging remains underexplored for coupled systems. In this
work, we theoretically investigated the dependence of their far-field
and near-field properties on their electron densities for various
coupled gold structures. With increasing electron densities, their
enhancement factors increase while their plasmonic resonance peaks
are blue-shifted. The resonance peak position of ellipsoid-ellipsoid
dimers shows the highest sensitivity in response to the charging effects
with the slope of −2.87. The surface-averaged electric field
of ellipsoid monomer shows largest enhancement ratio of 1.13 with
16% excess electrons. These results can be well explained by an effective
dipole moment model. In addition, we also studied the sphere-on-substrate
nanostructure which can be precisely fabricated. This system shows
low sensitivity to the charging effect with the slope of −1.46
but remarkable enhancement ratio of 1.13 on near field response with
16% excess electrons
Buckling analysis of variable angle tow composite plates with a through-the-width or an embedded rectangular delamination
Variable angle tow (VAT) composite laminates, in which fibre orientation varies spatially in-plane in a continuous fashion yet is piecewise constant through-thickness, have been made possible by advanced automated fibre placement technology. Such designs have shown considerable potential to improve the performance of lightweight composite structures. In the present study, an analytical model is developed to study the buckling behaviour of VAT composite plates with a through-the-width or an embedded rectangular delamination under compression loadings. The proposed model can accurately capture the global, local and mixed buckling response of delaminated VAT composite plates. Both free and constrained modes are assumed in the delamination buckling analysis. A constrained point approach is employed to analyse the buckling response when contact occurs between delaminated layers. The accuracy and reliability of this proposed delamination buckling model is validated by finite element analysis and with prior results. The influence of delamination size, position and varying fibre orientation angles on the buckling response of delaminated VAT composite plates is studied by numerical examples. It is shown that the buckling loads decrease with an increase of the delamination size. The VAT laminates with an off-midplane delamination may lead to the delamination opening up, which further reduces the buckling loads. Finally, the mechanism of taking advantages of VAT laminates to improve the buckling performance of delaminated composite plates is thoroughly investigated in a parametric study. This study also shows that the residual buckling resistance of the delaminated composite plates can be significantly improved through using the VAT design concept
Additional file 1 of A rare case of anti-DPPX encephalitis combined with neuroleptospirosis
Supplementary Material
High-Performance Ultrathin Active Chiral Metamaterials
Ultrathin
active chiral metamaterials with dynamically tunable
and responsive optical chirality enable new optical sensors, modulators,
and switches. Herein, we develop ultrathin active chiral metamaterials
of highly tunable chiroptical responses by inducing tunable near-field
coupling in the metamaterials and exploit the metamaterials as ultrasensitive
sensors to detect trace amounts of solvent impurities. To demonstrate
the active chiral metamaterials mediated by tunable near-field coupling,
we design moiré chiral metamaterials (MCMs) as model metamaterials,
which consist of two layers of identical Au nanohole arrays stacked
upon one another in moiré patterns with a dielectric spacer
layer between the Au layers. Our simulations, analytical fittings,
and experiments reveal that spacer-dependent near-field coupling exists
in the MCMs, which significantly enhances the spectral shift and line
shape change of the circular dichroism (CD) spectra of the MCMs. Furthermore,
we use a silk fibroin thin film as the spacer layer in the MCM. With
the solvent-controllable swelling of the silk fibroin thin films,
we demonstrate actively tunable near-field coupling and chiroptical
responses of the silk-MCMs. Impressively, we have achieved the spectral
shift over a wavelength range that is more than one full width at
half-maximum and the sign inversion of the CD spectra in a single
ultrathin (1/5 of wavelength in thickness) MCM. Finally, we apply
the silk-MCMs as ultrasensitive sensors to detect trace amounts of
solvent impurities down to 200 ppm, corresponding to an ultrahigh
sensitivity of >10<sup>5</sup> nm/refractive index unit (RIU) and
a figure of merit of 10<sup>5</sup>/RIU
Going Beyond the Millennium Ecosystem Assessment: An Index System of Human Well-Being
<div><p>Understanding the linkages between ecosystem services (ES) and human well-being (HWB) is crucial to sustain the flow of ES for HWB. The Millennium Ecosystem Assessment (MA) provided a state-of-the-art synthesis of such knowledge. However, due to the complexity of the linkages between ES and HWB, there are still many knowledge gaps, and in particular a lack of quantitative indicators and integrated models based on the MA framework. To fill some of these research needs, we developed a quantitative index system to measure HWB, and assessed the impacts of an external driver – the 2008 Wenchuan Earthquake – on HWB. Our results suggest that our proposed index system of HWB is well-designed, valid and could be useful for better understanding the linkages between ES and HWB. The earthquake significantly affected households' well-being in our demonstration sites. Such impacts differed across space and across the five dimensions of the sub-index (i.e., the basic material for good life, security, health, good social relations, and freedom of choice and action). Since the conceptual framework is based on the generalizable MA framework, our methods should also be applicable to other study areas.</p></div
Synthesis of Anisotropic Concave Gold Nanocuboids with Distinctive Plasmonic Properties
Gold
nanoparticles have attracted considerable attention owing
to their appealing plasmonic properties that have found applications
in sensing, imaging, and energy harvesting. In the present article,
we report the synthesis of anisotropic concave Au nanocuboids using
a seeded growth method controlled by a seed concentration. Unlike
conventional nonconcave counterparts which typically present two fundamental
plasmonic modes (transverse and longitudinal modes), our experimental
measurements and theoretical analysis show that the anisotropic concave
Au nanocuboid has three plasmonic resonances. Theoretical calculations
based on a finite element method confirm that the third resonance
is a transverse “edge” mode, which is enhanced by the
sharpened edges of the concave surfaces. This third resonance is found
to be separated from the conventional broad transverse mode band.
Because of the separation of the resonance mode, the quality-factor
of the original transverse mode shows nearly a 3-fold enhancement
Data_Sheet_4_Hydrogen peroxide-induced oxidative damage and protective role of peroxiredoxin 6 protein via EGFR/ERK signaling pathway in RPE cells.PDF
IntroductionDamage to retinal pigment epithelium (RPE) cells caused by oxidative stress is closely related to the pathogenesis of several blinding retinal diseases, such as age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerative conditions. However, the mechanisms of this process are poorly understood. Hence, the goal of this study was to investigate hydrogen peroxide (H2O2)-induced oxidative damage and protective role of peroxiredoxin 6 (PRDX6) protein via EGFR/ERK signaling pathway in RPE cells.MethodsCells from a human RPE cell line (ARPE-19 cells) were treated with H2O2, and then cell viability was assessed using the methyl thiazolyl tetrazolium assay. Cell death and reactive oxygen species (ROS) were detected by flow cytometry. The levels of PRDX6, epidermal growth factor receptor (EGFR), P38 mitogen-activated protein kinase (P38MAPK), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) were detected by Western blot assay. PRDX6 and EGFR were also detected via immunofluorescence staining.ResultsOur results show that H2O2 inhibited cell viability, induced cell death, and increased ROS levels in ARPE-19 cells. It was also found that H2O2 decreased the levels of PRDX6, EGFR, and phosphorylated ERK but increased the levels of phosphorylated P38MAPK and JNK. PRDX6 overexpression was found to attenuate H2O2-induced inhibition of cell viability and increased cell death and ROS production in ARPE-19 cells. PRDX6 overexpression also increased the expression of EGFR and alleviated the H2O2-induced decrease in EGFR and phosphorylated ERK. Moreover, inhibition of epidermal growth factor-induced EGFR and ERK signaling in oxidative stress was partially blocked by PRDX6 overexpression.DiscussionOur findings indicate that PRDX6 overexpression protects RPE cells from oxidative stress damage caused by decreasing ROS production and partially blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress. Therefore, PRDX6 shows promise as a therapeutic target for the prevention of RPE cell damage caused by oxidative stress associated with retinal diseases.</p
Data_Sheet_1_Hydrogen peroxide-induced oxidative damage and protective role of peroxiredoxin 6 protein via EGFR/ERK signaling pathway in RPE cells.PDF
IntroductionDamage to retinal pigment epithelium (RPE) cells caused by oxidative stress is closely related to the pathogenesis of several blinding retinal diseases, such as age-related macular degeneration (AMD), retinitis pigmentosa, and other inherited retinal degenerative conditions. However, the mechanisms of this process are poorly understood. Hence, the goal of this study was to investigate hydrogen peroxide (H2O2)-induced oxidative damage and protective role of peroxiredoxin 6 (PRDX6) protein via EGFR/ERK signaling pathway in RPE cells.MethodsCells from a human RPE cell line (ARPE-19 cells) were treated with H2O2, and then cell viability was assessed using the methyl thiazolyl tetrazolium assay. Cell death and reactive oxygen species (ROS) were detected by flow cytometry. The levels of PRDX6, epidermal growth factor receptor (EGFR), P38 mitogen-activated protein kinase (P38MAPK), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) were detected by Western blot assay. PRDX6 and EGFR were also detected via immunofluorescence staining.ResultsOur results show that H2O2 inhibited cell viability, induced cell death, and increased ROS levels in ARPE-19 cells. It was also found that H2O2 decreased the levels of PRDX6, EGFR, and phosphorylated ERK but increased the levels of phosphorylated P38MAPK and JNK. PRDX6 overexpression was found to attenuate H2O2-induced inhibition of cell viability and increased cell death and ROS production in ARPE-19 cells. PRDX6 overexpression also increased the expression of EGFR and alleviated the H2O2-induced decrease in EGFR and phosphorylated ERK. Moreover, inhibition of epidermal growth factor-induced EGFR and ERK signaling in oxidative stress was partially blocked by PRDX6 overexpression.DiscussionOur findings indicate that PRDX6 overexpression protects RPE cells from oxidative stress damage caused by decreasing ROS production and partially blocking the inhibition of the EGFR/ERK signaling pathway induced by oxidative stress. Therefore, PRDX6 shows promise as a therapeutic target for the prevention of RPE cell damage caused by oxidative stress associated with retinal diseases.</p
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