Development of Hospice Care Service for the Elderly in China

Du Peng,Wang Yongmei 서울대학교 사회발전연구소 2016 Journal of Asian Sociology Vol.45 No.2

Against the backdrop of the aging society, we need to make great efforts to develop the hospice care service for the elderly if we want to comprehensively improve “the Quality of Death” and enable more old people to enjoy benefits of dying peacefully. This essay firstly reviews the policies and practices of the development of hospice care for the elderly in China, and we discover that main obstacles that hinder its development are institutional barriers, difficulties in financing, a lack of personnel, and low acceptance rate of the general public. Considering the current construction of socialized pension service system in China, we make institutional exploration in the development of the hospice care of the elderly in China. And we hold that these are key ways to develop this career to “get through” the lifeblood of the medical and health services and the hospice care service, “extend” the socialized system of elderly care service to this service, enhance the “input” in this service, and fully develop the long-acting “safeguard” mechanism for the development of this service.

Real-time detection of the nanoparticle induced phytotoxicity in rice root tip through the visible red emissions of Eu³⁺ ions

Du, Peng,Wu, Yunfei,Yu, Jae Su The Royal Society of Chemistry 2018 PHOTOCHEMICAL AND PHOTOBIOLOGICAL SCIENCES Vol.17 No.4

<P>Phytotoxicity is one of the most important factors involved in the reduction of crop production. With the introduction of NaBiF4 nanoparticles, the effect of the particle size (>50 nm) on rice development was systematically studied. Through the exogenous treatment of multiple concentrations of nanoparticles, the primary root length, lateral root number, and lateral root length were significantly inhibited under higher content of nanoparticles, but more crown root formation was induced, which might be due to phytotoxicity. With the help of the red emission of the Eu<SUP>3+</SUP>-activated NaBiF4 nanoparticles, we could infer that the nanoparticles were accumulated in the root tip cells in the division and elongation zone but not in the mature region. Additionally, the investigation on the influence of the studied nanoparticles on the gene level and the expression of phytotoxicity related genes was performed to further identify the effect of the nanoparticles on the rice root development. These results potentially explain the effect of larger nanoparticles on phytotoxicity in the plant roots.</P>

Luminescence properties and energy transfer behavior of single-component NaY(WO₄)₂:Tm³⁺/Dy³⁺/Eu³⁺ phosphors for ultraviolet-excited white light-emitting diodes

Du, Peng,Wang, Lili,Yu, Jae Su Elsevier 2016 JOURNAL OF ALLOYS AND COMPOUNDS Vol.673 No.-

<P><B>Abstract</B></P> <P>The single-component NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:Tm<SUP>3+</SUP>/Dy<SUP>3+</SUP>/Eu<SUP>3+</SUP> color-controllable phosphors were synthesized by a facile high-temperature solid-state reaction technique. The X-ray diffraction patterns, field-emission electron scanning microscope images and photoluminescence (PL) spectra were measured to characterize the prepared phosphors. All the samples possessed pure tetragonal phase and consisted of micro-sized particles. Under ultraviolet light excitation, the characteristic emissions of Tm<SUP>3+</SUP>, Dy<SUP>3+</SUP> and Eu<SUP>3+</SUP> ions were observed. Moreover, the emission color of the NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:0.01Tm<SUP>3+</SUP>/<I>x</I>Dy<SUP>3+</SUP> phosphors was tuned from blue to white by adjusting the Dy<SUP>3+</SUP> ion concentration. The PL spectra revealed that there existed an efficient energy transfer (ET) from Tm<SUP>3+</SUP> to Dy<SUP>3+</SUP> ions and the ET mechanism was determined to be a resonant type <I>via</I> dipole–dipole interaction. Through theoretical calculation, the ET efficiency was found to be as high as 46.1% when <I>x</I> = 0.05 and the critical distance was 6.54 Å. With the introduction of Eu<SUP>3+</SUP> ions, the corrected color temperature of the products was modified and the emission color was also changed from pure white to reddish white. These obtained single-component white light-emitting NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:Tm<SUP>3+</SUP>/Dy<SUP>3+</SUP>/Eu<SUP>3+</SUP> phosphors were expected to be a potential candidate for phosphor-converted white light-emitting diode applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Under 358 nm excitation, the obtained samples exhibited the emissions of Tm<SUP>3+</SUP>, Dy<SUP>3+</SUP> and Eu<SUP>3+</SUP> ions. </LI> <LI> Owing to the ET from Tm<SUP>3+</SUP> to Dy<SUP>3+</SUP> ions, the emission color of the phosphors was changed from blue to white. </LI> <LI> The ET efficiency in the NaY(WO<SUB>4</SUB>)<SUB>2</SUB>:0.01Tm<SUP>3+</SUP>/xDy<SUP>3+</SUP> phosphors was up to 46.1% when x = 0.05. </LI> <LI> Through theoretical analysis, the ET mechanism from Tm<SUP>3+</SUP> to Dy<SUP>3+</SUP> ions was the dipole–dipole interaction. </LI> <LI> With the tridoping of Eu<SUP>3+</SUP> ions, the CCT value of the as-prepared phosphors was modified. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

High-resolution Mapping of Hyperglycemia-induced Gastric Slow Wave Dysrhythmias

Peng Du,Gregory O’Grady,Niranchan Paskaranandavadivel,Shou-jiang Tang,Thomas Abell,Leo K Cheng 대한소화기 기능성질환∙운동학회 2019 Journal of Neurogastroenterology and Motility (JNM Vol.25 No.2

Background/Aims It is now recognised that gastric dysrhythmias are best characterised by their spatial propagation pattern. Hyperglycemia is an important cause of gastric slow wave dysrhythmia, however, the spatiotemporal patterns of dysrhythmias in this context have not been investigated. This study aims to investigate the relationship between hyperglycemia and the patterns of dysrhythmias by employing high-resolution (multi-electrode) mapping simultaneously at the anterior and posterior gastric serosa. Methods High-resolution mapping (8 × 16 electrodes per serosal) was performed in 4 anesthetized hounds. Baseline recordings (21 ± 8 minutes) were followed by intravenous injection of glucagon (0.5 mg per dose) and further recordings (59 ± 15 minutes). Blood glucose levels were monitored manually using a glucose sensing kit at regular 5-minute intervals. Slow wave activation maps, amplitudes, velocity, anisotropic ratio, and frequency were calculated. Differences were compared between baseline and post glucagon injection. Results Baseline slow waves propagated symmetrically and antegrade. The blood glucose levels were increased by an average of 112% compared to the baseline by the end of the recordings. All subjects demonstrated elevated incidence of slow wave dysrhythmias following injection compared to the baseline (48 ± 23% vs 6 ± 4%, P < 0.05). Dysrhythmias arose simultaneously or independently on anterior and posterior serosa. Spatial dysrhythmias occurred before and persisted after the onset and disappearance of temporal dysrhythmias. Conclusions Infusion of glucagon induced gastric slow wave dysrhythmias, which occurred across a heterogeneous range of patterns and frequencies. The spatial dysrhythmias of gastric slow waves were shown to be more prevalent and persisted over a longer period of time compared to the temporal dysrhythmias.

Energy transfer from VO₄ ³⁻ group to Sm³⁺ ions in Ba₃(VO₄)₂:3<i>x</i>Sm³⁺ microparticles: A bifunctional platform for simultaneous optical thermometer and safety sign

Du, Peng,Hua, Yongbin,Yu, Jae Su Elsevier 2018 Chemical engineering journal Vol.352 No.-

<P><B>Abstract</B></P> <P>The Sm<SUP>3+</SUP>-doped Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB> microparticles were successfully synthesized via a simple sol-gel method. Both the recorded three-dimensional photoluminescence (PL) emission spectra and counter lines revealed that the near-ultraviolet light was a proper excitation lighting source for the studied samples. Under 352 nm of irradiation, the effect of Sm<SUP>3+</SUP> ion concentration on the PL emission properties of the microparticles was investigated and the optimum doping concentration was demonstrated to be 4 mol%. Based on the diversity in the thermal quenching performance of VO<SUB>4</SUB> <SUP>3−</SUP> group and Sm<SUP>3+</SUP> ions, a novel self-referencing non-invasion optical thermometer with high sensitivity and superior signal discriminability was designed. By taking the advantage of the temperature-dependent fluorescence intensity ratio between the VO<SUB>4</SUB> <SUP>3−</SUP> group and Sm<SUP>3+</SUP> ions, the optical thermometric properties of the Sm<SUP>3+</SUP>-doped Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB> microparticles in the temperature range of 303–463 K were analyzed. The maximum absolute and relative sensor sensitivities, which were hardly influenced by the PL emission intensity, were obtained to be 0.039 K<SUP>−1</SUP> and 2.24% K<SUP>−1</SUP>, respectively. Furthermore, the emitting color of the resultant compounds was found to be significantly dependent on the external temperature. These results suggest that the Sm<SUP>3+</SUP>-doped Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB> microparticles are a potential candidate for high-performance self-referencing optical thermometer and safety sign applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> All the samples can be excited by NUV light and the optimal doping content was 4 mol%. </LI> <LI> The energy transfer efficiency from VO<SUB>4</SUB> <SUP>3−</SUP> group to Sm<SUP>3+</SUP> ions reached up to 82.3% when <I>x</I> = 0.2. </LI> <LI> The FIR value of PL emission intensities of Sm<SUP>3+</SUP> to VO<SUB>4</SUB> <SUP>3−</SUP> was dependent on the temperature. </LI> <LI> The maximum absolution and relative sensor sensitivities were 0.039 K<SUP>−1</SUP> and 2.24% K<SUP>−1</SUP>, respectively. </LI> <LI> The emitting color relied on the temperature, which makes it suitable for safety sign. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Critic acid-assisted sol-gel synthesis of bifunctional Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB>:3<I>x</I>Sm<SUP>3+</SUP> microparticles for non-contact optical temperature sensor and safety sign.</P> <P>[DISPLAY OMISSION]</P>

Enhanced Photovoltaic Performance of Dye-Sensitized Solar Cells by Efficient Near-Infrared Sunlight Harvesting using Upconverting Y ₂ O ₃ :Er ³⁺ /Yb ³⁺ Phosphor Nanoparticles

Du, Peng,Lim, Joo Ho,Leem, Jung Woo,Cha, Sung Min,Yu, Jae Su Springer US 2015 NANOSCALE RESEARCH LETTERS Vol.10 No.1

<P>We report the efficiency enhancement in dye-sensitized solar cells (DSSCs) using Er<SUP>3+</SUP>/Yb<SUP>3+</SUP>-co-doped Y<SUB>2</SUB>O<SUB>3</SUB> (i.e., Y<SUB>2</SUB>O<SUB>3</SUB>:Er<SUP>3+</SUP>/Yb<SUP>3+</SUP>) phosphor nanoparticles, prepared by a simple and cost-effective urea-based homogeneous precipitation method, for efficient near-infrared (NIR) sunlight harvesting. Under the light excitation at a wavelength of 980 nm, the as-prepared samples exhibited strong upconversion emissions at green and red visible wavelengths. To investigate the influence of Y<SUB>2</SUB>O<SUB>3</SUB>:Er<SUP>3+</SUP>/Yb<SUP>3+</SUP> nanoparticles on the photovoltaic performance of DSSCs, the phosphor nanoparticles were incorporated into titanium dioxide films to form a composite photoelectrode. For the resulting DSSCs, the increased power conversion efficiency (<I>PCE</I>) of 6.68 % was obtained mainly by the increased photocurrent of <I>J</I><SUB>SC</SUB> = 13.68 mA/cm<SUP>2</SUP> due to the light harvesting enhancement via the NIR-to-visible upconversion process (cf., <I>PCE</I> = 5.94 %, <I>J</I><SUB>SC</SUB> = 12.74 mA/cm<SUP>2</SUP> for the reference DSSCs without phosphor nanoparticles), thus, indicating the <I>PCE</I> increment ratio of ~12.4 %.</P>

Cation Substitution Induced Enhanced Photoluminescence Properties of Gd_2(1-x-y)Y_2xMo₄O₁₅:2yEu³⁺ Phosphors for Indoor Lighting

Du, Peng,Yu, Jae Su The Korean Vacuum Society 2018 Applied Science and Convergence Technology Vol.27 No.3

We reported a new method to enhance the photoluminescence (PL) properties of $Eu^{3+}$ ions doped $Gd_2Mo_4O_{15}$ phosphors via cation substitution. With the aid of conventional sol-gel method, a series of $Eu^{3+}$ ions doped $Gd_{2(1-x)}Y_{2x}Mo_4O_{15}$ phosphors were prepared. The prepared samples emitted red light when excited at 393 nm. Moreover, when part of the $Gd^{3+}$ ions was substituted by the $Y^{3+}$ ions, the PL emission intensity of the studied samples was enhanced and the optimal doping concentration for $Y^{3+}$ ions was 30 mol%. The calculated CIE coordinate (0.663,0.337) was situated in the red region. Furthermore, the thermal quenching behaviors of the synthesized $Eu^{3+}$ ions doped $Gd_{2(1-x)}Y_{2x}Mo_4O_{15}$ phosphors were studied. At last, we also packaged a red-emitting light-emitting diode device by integrating the obtained phosphors and a near-ultraviolet chip to verify the applications of the $Eu^{3+}$ ions doped $Gd_{2(1-x)}Y_{2x}Mo_4O_{15}$ phosphors for indoor lighting.

Local symmetry distortion-induced enhancement of upconversion luminescence in Gd2O3:Ho3+/Yb3+/Zn2+ nanoparticles for solid-state lighting and bioimaging

Peng Du,김은중,유재수 한국물리학회 2018 Current Applied Physics Vol.18 No.3

The Ho3+/Yb3+/Zn2+-tridoped Gd2O3 nanoparticles were prepared by a simple urea-based homogeneous precipitation method. Under near-infrared (NIR) light excitation, all the synthesized nanoparticles exhibit bright green and red upconversion (UC) emissions corresponding to the intra-4f transitions of Ho3+ ions and the UC mechanism is found to be a two-photon process. With the introduction of Zn2+ ions, not only the local symmetry surrounding the dopants is decreased, but also the UC emission intensity is also enhanced, which is further verified by the Judd-Ofelt theory. The temperature-dependent UC emission spectra were recorded to examine the thermal stability of the final products. From theoretical calculations, the activation energy is found to be about 0.18 eV. A novel green light-emitting diode device, which consists of the resultant nanoparticles and a NIR chip, was fabricated to examine their suitability for solid-state lighting. Meanwhile, the synthesized nanoparticles exhibit low cytotoxicity in various cell lines, suggesting their potential applications in in vivo UC luminescence imaging. Additionally, the applicability of the Ho3+/Yb3+/Zn2+-tridoped Gd2O3 nanoparticles for in vivo bioimaging applications was also analyzed.

Local symmetry distortion-induced enhancement of upconversion luminescence in Gd₂O₃:Ho³⁺/Yb³⁺/Zn²⁺ nanoparticles for solid-state lighting and bioimaging

Du, Peng,Kim, Eun-Joong,Yu, Jae Su ELSEVIER 2018 Current Applied Physics Vol.18 No.3

<P>The Ho3+/Yb3+/Zn2+-tridoped Gd2O3 nanoparticles were prepared by a simple urea-based homogeneous precipitation method. Under near-infrared (NIR) light excitation, all the synthesized nanoparticles exhibit bright green and red upconversion (UC) emissions corresponding to the intra-4f transitions of Ho3+ ions and the UC mechanism is found to be a two-photon process. With the introduction of Zn2+ ions, not only the local symmetry surrounding the dopants is decreased, but also the UC emission intensity is also enhanced, which is further verified by the Judd-Ofelt theory. The temperature-dependent UC emission spectra were recorded to examine the thermal stability of the final products. From theoretical calculations, the activation energy is found to be about 0.18 eV. A novel green light-emitting diode device, which consists of the resultant nanoparticles and a NIR chip, was fabricated to examine their suitability for solid-state lighting. Meanwhile, the synthesized nanoparticles exhibit low cytotoxicity in various cell lines, suggesting their potential applications in in vivo UC luminescence imaging. Additionally, the applicability of the Ho3+/Yb3+/Zn2+-tridoped Gd2O3 nanoparticles for in vivo bioimaging applications was also analyzed. (C) 2018 Elsevier B.V. All rights reserved.</P>

Cation Substitution Induced Enhanced Photoluminescence Properties of Gd<SUB>2(1-x-y)</SUB>Y<SUB>2x</SUB>Mo<SUB>4</SUB>O<SUB>15</SUB>:2yEu<SUP>3+</SUP> Phosphors for Indoor Lighting

Peng Du,Jae Su Yu 한국진공학회(ASCT) 2018 Applied Science and Convergence Technology Vol.27 No.3

We reported a new method to enhance the photoluminescence (PL) properties of Eu<SUP>3+</SUP> ions doped Gd₂Mo₄O15 phosphors via cation substitution. With the aid of conventional sol-gel method, a series of Eu<SUP>3+</SUP> ions doped Gd2(1-x)Y2xMo₄O15 phosphors were prepared. The prepared samples emitted red light when excited at 393 nm. Moreover, when part of the Gd<SUP>3+</SUP> ions was substituted by the Y<SUP>3+</SUP> ions, the PL emission intensity of the studied samples was enhanced and the optimal doping concentration for Y3+ ions was 30 mol%. The calculated CIE coordinate (0.663,0.337) was situated in the red region. Furthermore, the thermal quenching behaviors of the synthesized Eu<SUP>3+</SUP> ions doped Gd2(1-x)Y2xMo₄O15 phosphors were studied. At last, we also packaged a red-emitting light-emitting diode device by integrating the obtained phosphors and a near-ultraviolet chip to verify the applications of the Eu<SUP>3+</SUP> ions doped Gd2(1-x)Y2xMo₄O15 phosphors for indoor lighting.