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1.
Nanotechnology ; 29(1): 015404, 2018 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-29115283

RESUMEN

The electrical conductivity and Seebeck coefficient of RuO2 nanosheets are enhanced by metal nanoparticle doping using Ag-acetate solutions. In this study, RuO2 monolayer and bilayer nanosheets exfoliated from layered alkali metal ruthenates are transferred to Si substrates for device fabrication, and the temperature dependence of their conductivity and Seebeck coefficients is investigated. For pristine RuO2 nanosheets, the sign of the Seebeck coefficient changes with temperature from 350-450 K. This indicates that the dominant type of charge carrier is dependent on the temperature, and the RuO2 nanosheets show ambipolar carrier transport behavior. By contrast, the sign of the Seebeck coefficient for Ag nanoparticle-doped RuO2 nanosheets does not change with temperature, indicating that the extra charge carriers from metal nanoparticles promote n-type semiconductor behavior.

2.
Am J Physiol Renal Physiol ; 311(1): F195-206, 2016 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-26823279

RESUMEN

The intrarenal renin-angiotensin system (RAS) has an important role in generating and maintaining hypertension in two-kidney, one-clip (2K1C) rats. This study evaluated how various intrarenal RAS components contributed to hypertension not only in the maintenance period (5w; 5 wk after operation) but also earlier (2w; 2 wk after operation). We inserted a 2.5-mm clip into the left renal artery of Sprague-Dawley rats and euthanized them at 2w and 5w following the operation. Systolic blood pressure increased within 1 wk after the operation, and left ventricular hypertrophy occurred in 2K1C rats. At 2w, juxtaglomerular apparatus (JGA) and collecting duct (CD) renin increased in clipped kidney (CK) of 2K1C rats. The tubular angiotensin I-converting enzyme (ACE) was not changed, but peritubular ACE2 decreased in nonclipped kidney (NCK) and CK of 2K1C rats. At 5w, ACE and CD renin were enhanced, and ACE2 was still lessened in both kidneys of 2K1C rats. However, plasma renin activity (PRA) was not different from that in sham rats. In proximal tubules of CK, the ANG II type 1 receptor (AT1R) was not suppressed, but the Mas receptor (MasR) was reduced; thus the AT1R/MasR ratio was elevated. Although hypoxic change in CK could not be excluded, the JGA renin of CK and CD renin in both kidneys was highly expressed independent of time. Peritubular ACE2 changed in the earlier period, and uninhibited AT1R in proximal tubules of CK was presented in the maintenance period. In 2K1C rats, attenuated ACE2 seems to contribute to initiating hypertension while upregulated ACE in combination with unsuppressed AT1R may have a key role in maintaining hypertension.


Asunto(s)
Hipertensión Renal/fisiopatología , Hipertensión Renovascular/fisiopatología , Riñón/fisiopatología , Nefritis/fisiopatología , Sistema Renina-Angiotensina , Animales , Presión Sanguínea , Progresión de la Enfermedad , Ecocardiografía , Hipertensión Renal/etiología , Hipertensión Renovascular/complicaciones , Hipertrofia Ventricular Izquierda/diagnóstico por imagen , Hipertrofia Ventricular Izquierda/etiología , Aparato Yuxtaglomerular/patología , Túbulos Renales Colectores/patología , Masculino , Nefritis/etiología , Ratas , Ratas Sprague-Dawley
3.
Am J Physiol Renal Physiol ; 308(9): F993-F1003, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25651569

RESUMEN

IL-1ß-secreting nucleotide-binding oligomerization domain protein 3 (NLRP3) inflammasomes play a pivotal role in triggering innate immune responses in metabolic disease. We investigated the role of soluble uric acid in NLRP3 inflammasome activation in macrophages to demonstrate the effect of systemic hyperuricemia on progressive kidney damage in type 2 diabetes. THP-1 cells, human acute monocytic leukemia cells, were cultured to obtain macrophages, and HK-2 cells, human renal proximal tubule cells, were cultured and stimulated with uric acid. In vivo, we designed four rat groups as follows: 1) Long-Evans Tokushima Otsuka (LETO); 2) Otsuka Long-Evans Tokushima Fatty (OLETF); 3) OLETF+high-fructose diet (HFD) for 16 wk; and 4) OLETF+HFD+allopurinol (10 mg/dl administered in the drinking water). Soluble uric acid stimulated NLRP3 inflammasomes to produce IL-1ß in macrophages. Uric acid-induced MitoSOX mediates NLRP3 activation and IL-1ß secretion. IL-1ß from macrophages activates NF-κB in cocultured proximal tubular cells. In vivo, intrarenal IL-1ß expression and macrophage infiltration increased in HFD-fed OLETF rats. Lowering the serum uric acid level resulted in improving the albuminuria, tubular injury, macrophage infiltration, and renal IL-1ß (60% of HFD-fed OLETF) independently of glycemic control. Direct activation of proximal tubular cells by uric acid resulted in (C-X-C motif) ligand 12 and high mobility group box-1 release and accelerated macrophage recruitment and the M1 phenotype. Taken together, these data support direct roles of hyperuricemia in activating NLRP3 inflammasomes in macrophages, promoting chemokine signaling in the proximal tubule and contributing to the progression of diabetic nephropathy through cross talk between macrophages and proximal tubular cells.


Asunto(s)
Proteínas Portadoras/metabolismo , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/etiología , Hiperuricemia/complicaciones , Inflamasomas/metabolismo , Inflamación/etiología , Túbulos Renales Proximales/metabolismo , Macrófagos/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Ácido Úrico/metabolismo , Animales , Proteínas Portadoras/genética , Línea Celular , Quimiocina CXCL12/metabolismo , Técnicas de Cocultivo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/inmunología , Diabetes Mellitus Tipo 2/metabolismo , Nefropatías Diabéticas/genética , Nefropatías Diabéticas/inmunología , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/prevención & control , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Supresores de la Gota/farmacología , Proteína HMGB1/metabolismo , Humanos , Hiperuricemia/tratamiento farmacológico , Hiperuricemia/inmunología , Hiperuricemia/metabolismo , Inflamasomas/genética , Inflamación/inmunología , Inflamación/metabolismo , Mediadores de Inflamación/metabolismo , Interleucina-1beta/metabolismo , Túbulos Renales Proximales/efectos de los fármacos , Túbulos Renales Proximales/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Masculino , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR , Interferencia de ARN , Ratas Endogámicas OLETF , Transducción de Señal , Factores de Tiempo , Transfección
4.
Am J Nephrol ; 42(3): 250-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26484659

RESUMEN

BACKGROUND: Anti-phospholipase A2 receptor antibody (PLA2R-Ab) is useful in diagnosing idiopathic membranous nephropathy (IMN). We investigated the clinical relevance of PLA2R-Ab enzyme-linked immunosorbent assay (ELISA) in patients with IMN. METHODS: We measured PLA2R-Ab with an ELISA kit from the serum of 160 patients with IMN (n = 93), secondary MN (n = 14) and other glomerulonephritis (n = 41) as well as healthy controls (n = 12) at the time of renal biopsy and investigated the correlation of titers of PLA2R-Ab with clinical parameters. RESULTS: PLA2R-Ab was positive in 41 of 93 patients (44.1%) with IMN. No samples from the patients with secondary MN and other glomerulonephritis or healthy controls were positive with the ELISA test. The PLA2R-Ab-positive patients showed severe disease activity and a low remission rate. The PLA2R-Ab titer positively correlated with proteinuria and was negatively associated with renal function and serum albumin. The patients with a high titer of PLA2R-Ab had significantly decreased remission rates. The cumulative probabilities of remission was significantly lower in patients with PLA2R-Ab (p = 0.01) and even so in patients with a high titer of PLA2R-Ab (p = 0.04). When we compared the ELISA titers with Western blot (WB) data of 43 patients who had been enrolled in our previous study, 18 and 30 patients were positive on ELISA (41.9%) and WB (69.8%), respectively. WB and ELISA had a concordance rate of 72.1% and were positively correlated (r = 0.590, p < 0.001). CONCLUSION: The presence, as well as a high titer, of PLA2R-Ab on ELISA was associated with poor prognosis of IMN. Assessment of PLA2R-Ab with ELISA is an easy and reliable tool for the diagnosis and guidance of therapeutic plans.


Asunto(s)
Glomerulonefritis Membranosa/inmunología , Receptores de Fosfolipasa A2/inmunología , Western Blotting , Estudios de Casos y Controles , Ensayo de Inmunoadsorción Enzimática , Femenino , Glomerulonefritis Membranosa/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Pronóstico
5.
J Phys Ther Sci ; 27(3): 677-9, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25931706

RESUMEN

[Purpose] The aim of this study was to examine the effects of upper limb robot-assisted therapy in the rehabilitation of stroke patients. [Subjects and Methods] Fifteen stroke patients with no visual or cognitive problems were enrolled. All subjects received robot-assisted therapy and comprehensive rehabilitation therapy for 30 minutes each. The experimental group received a conventional therapy and an additional half hour per weekday of robot therapy. The patients participated in a total of 20 sessions, each lasting 60 minutes (conventional therapy 30 min, robot-assisted therapy 30 min), which were held 5 days a week for 4 weeks. [Result] The patients showed a significant difference in smoothness and reach error of the point to point test, circle size and independence of the circle in the circle test, and hold deviation of the playback static test between before and after the intervention. On the other hand, no significant difference was observed in the displacement of the round dynamic test. The patients also showed significant improvement in the Fugl-Meyer Assessment and Modified Barthel Index after the intervention. [Conclusion] These kinematic factors can provide good information when analyzing the upper limb function of stroke patients in robot-assisted therapy. Nevertheless, further research on technology-based kinematic information will be necessary.

6.
Behav Sci (Basel) ; 14(4)2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38667079

RESUMEN

Moral injury syndrome (MIS) is a mental health (MH) problem that substantially affects resilience; the presence of MIS reduces responsiveness to psychotherapy and increases suicide risk. Evidence-based treatment for MIS is available; however, it often goes untreated. This project uses principles of the Consolidated Framework for Implementation Research (CFIR) to assess barriers and facilitators to the implementation of Building Spiritual Strength (BSS), a multi-disciplinary treatment for MIS. Interviews were conducted with chaplains and mental health providers who had completed BSS facilitator training at six sites in the VA. Data were analyzed using the Hamilton Rapid Turnaround method. Findings included multiple facilitators to the implementation of BSS, including its accessibility and appeal to VA chaplains; leadership by VA chaplains trained in the intervention; and effective collaboration between the chaplains and mental health providers. Barriers to the implementation of BSS included challenges in engaging mental health providers and incorporating them as group leaders, veterans' lack of familiarity with the group format of BSS, and the impact of the COVID-19 pandemic. Results highlight the need for increased trust and collaboration between VA chaplains and mental health providers in the implementation of BSS and treatment of MIS.

7.
Materials (Basel) ; 16(10)2023 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-37241445

RESUMEN

Skutterudite compounds have been studied as potential thermoelectric materials due to their high thermoelectric efficiency, which makes them attractive candidates for applications in thermoelectric power generation. In this study, the effects of double-filling on the thermoelectric properties of the CexYb0.2-xCo4Sb12 skutterudite material system were investigated through the process of melt spinning and spark plasma sintering (SPS). By replacing Yb with Ce, the carrier concentration was compensated for by the extra electron from Ce donors, leading to optimized electrical conductivity, Seebeck coefficient, and power factor of the CexYb0.2-xCo4Sb12 system. However, at high temperatures, the power factor showed a downturn due to bipolar conduction in the intrinsic conduction regime. The lattice thermal conductivity of the CexYb0.2-xCo4Sb12 skutterudite system was clearly suppressed in the range between 0.025 and 0.1 for Ce content, due to the introduction of the dual phonon scattering center from Ce and Yb fillers. The highest ZT value of 1.15 at 750 K was achieved for the Ce0.05Yb0.15Co4Sb12 sample. The thermoelectric properties could be further improved by controlling the secondary phase formation of CoSb2 in this double-filled skutterudite system.

8.
ACS Appl Mater Interfaces ; 14(27): 30649-30657, 2022 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-35708228

RESUMEN

In this study, we investigated the effect of the stacking order of metal precursors on the formation of volume defects, such as blisters and nanopores, in CZTSSe thin-film solar cells. We fabricated CZTSSe thin films using three types of metal-precursor combinations, namely, Zn/Cu/Sn/Mo, Cu/Zn/Sn/Mo, and Sn/Cu/Zn/Mo, and studied the blister formation. The blister-formation mechanism was based on the delamination model, taking into consideration the compressive stress and adhesion properties. A compressive stress could be induced during the preferential formation of a ZnSSe shell. Under this stress, the adhesion between the ZnSSe film and the Mo substrate could be maintained by the surface tension of a metallic liquid phase with good wettability, or by the functioning of ZnSSe pillars as anchors, depending on the type of metal precursor used. Additionally, the nanopore formation near the back-contact side was found to be induced by the columnar microstructure of the metal precursor with the Cu/Zn/Mo stacking order and its dezincification. Based on the two volume-defect-formation mechanisms proposed herein, further development of volume-defect-formation suppression technology is expected to be made.

9.
Small Methods ; 5(5): e2001264, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-34928087

RESUMEN

The bevel structure of organic multilayers produced by finely controlled Ar gas cluster ion beam sputtering preserves both the molecular distribution and chemical states. Nevertheless, there is still an important question of whether this method can be applicable to organic multilayer structures composed of complex or ambiguous interfaces used in real organic optoelectronic devices. Herein, various bevel structures are fabricated from different types of organic semiconductors using a solution-based deposition technique: complicatedly intermixed electron-donor and electron-acceptor bulk heterojunction structure, thin film structure with an internal donor-acceptor concentration gradient, and multi-layered structure with more than three layers. For these organic material combinations listed above, the bevel structure is fabricated with finely tuned Ar gas cluster ion beam sputtering. The location-dependent X-ray photoelectron spectroscopy (XPS) results obtained for each bevel structure exactly correspond to the XPS depth profiles. This result demonstrates that the bevel structure analysis is a powerful method to distinguish subtle differences in chemical component distributions and chemical states of organic semiconductors even with complex or ambiguous interfaces. Ultimately, due to its reliability as verified by this study, the proposed bevel structure analysis is expected to greatly expand other analytical techniques with a limited spatial or depth resolution.

10.
ACS Appl Mater Interfaces ; 13(9): 11396-11402, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33480686

RESUMEN

Facile strategies in flexible transparent conductive electrode materials that can sustain their electrical conductivities under 1 mm-scale radius of curvature are required for wider applications such as foldable devices. We propose a rational design as well as a fabrication process for a silver nanowire-based transparent conductive electrode with low sheet resistance and high transmittance even after prolonged cyclic bending. The electrode is fabricated on a poly(ethylene terephthalate) film through the hybridization of silver nanowires with silver nanoparticles-anchored RuO2 nanosheets. This hybridization significantly improves the performance of the silver nanowire network under severe bending strain and creates an electrically percolative structure between silver nanowires and RuO2 nanosheets in the presence of anchored silver nanoparticles on the surface of RuO2 nanosheets. The resistance change of this hybrid transparent conductive electrode is 8.8% after 200,000 bending cycles at a curvature radius of 1 mm, making it feasible for use in foldable devices.

11.
Artículo en Inglés | MEDLINE | ID: mdl-33076387

RESUMEN

The number of older adults admitted to nursing homes is steadily increasing, and the health management for them is a very important issue in Korean society. This study aimed to examine the effects of Yangsaeng (health management) therapy on physical health status, depression, life satisfaction, and Yangsaeng (health management) of Korean older adults in nursing homes. A quasi-experimental study design using a pretest-posttest control group was employed. Study participants were a total of 80 older adults (intervention: n = 40, control: n = 40) in a nursing home in Seoul, South Korea. Yangsaeng therapy as an intervention consisted of the Meridian therapy and Qi-gong therapy. Yangsaeng therapy was conducted for 50 min per one time, twice a week, and for 10 weeks. Measures were general characteristics of study participants, Cornell Medical Index, Geriatric Depression Scale, life satisfaction scale, and Yangsaeng scale. Data were collected from April 2018 to March 2019. There were statistically significant differences on physical health status, depression, life satisfaction, and Yangsaeng between the two groups. Yangsaeng therapy was an effective intervention for improving physical health status, life satisfaction, and Yangsaeng, and for decreasing depression of older adults in nursing homes. Health care providers need to pay attention to Yangsaeng therapy as a Korean traditional intervention method for the health management of the older adults residing in nursing homes.


Asunto(s)
Manejo de la Enfermedad , Estado de Salud , Casas de Salud , Anciano , Femenino , Conductas Relacionadas con la Salud , Humanos , Masculino , República de Corea , Seúl , Instituciones de Cuidados Especializados de Enfermería
12.
Micromachines (Basel) ; 11(6)2020 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-32526961

RESUMEN

We prepared the hybrid conductor of the Ag nanowire (NW) network and irregularly patterned graphene (GP) mesh with enhanced optical transmittance (~98.5%) and mechano-electric stability (ΔR/Ro: ~42.4% at 200,000 (200k) cycles) under 6.7% strain. Irregularly patterned GP meshes were prepared with a bottom-side etching method using chemical etchant (HNO3). The GP mesh pattern was judiciously and easily tuned by the regulation of treatment time (0-180 min) and concentration (0-20 M) of chemical etchants. As-formed hybrid conductor of Ag NW and GP mesh exhibit enhanced/controllable electrical-optical properties and mechano-electric stabilities; hybrid conductor exhibits enhanced optical transmittance (TT = 98.5%) and improved conductivity (ΔRs: 22%) compared with that of a conventional hybrid conductor at similar TT. It is also noteworthy that our hybrid conductor shows far superior mechano-electric stability (ΔR/Ro: ~42.4% at 200k cycles; TT: ~98.5%) to that of controls (Ag NW (ΔR/Ro: ~293% at 200k cycles), Ag NW-pristine GP hybrid (ΔR/Ro: ~121% at 200k cycles)) ascribed to our unique hybrid structure.

13.
ACS Appl Mater Interfaces ; 12(41): 46037-46044, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-32996764

RESUMEN

In this study, to control the formation of non-uniformly distributed large voids and Cu-Sn alloy agglomeration, which leads to local compositional misfit and secondary phase formation, a SnS compound precursor was applied instead of metal Sn to avoid compositional non-uniformity. Using a Cu/Zn/SnS stacked precursor, a temperature tracking experiment was conducted to confirm the formation controllability of the void and the secondary phase. According to the results of this temperature-profile tracking experiment, it was confirmed that the large void was successfully controlled; however, an additional ZnSSe secondary phase layer was formed in the middle of the CZTSSe upper layer and small voids were distributed relatively uniformly in the bottom CZTSSe layer. An efficiency of approximately 8% was obtained when the Cu/Zn/SnS stacked precursor was used. The origins of the low short-circuit current and fill factor are posited to be caused by the increase of the energy bandgap of the CZTSSe layer due to the SnS precursor, the thin top CZTSSe layer (around 600 nm) of the triple CZTSSe layer, and the diffusion length extension of the minor carriers caused by bypassing the ZnSSe phase.

14.
Nanomaterials (Basel) ; 10(9)2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-32962147

RESUMEN

In this study, a 5-nm thick Al2O3 layer was patterned onto the Mo electrode in the form of a dot to produce a local rear contact, which looked at the effects of this contact structure on Cu2ZnSn(S1-xSex)4 (CZTSSe) growth and solar cell devices. Mo was partially exposed through open holes having a square dot shape, and the closed-ratios of Al2O3 passivated areas were 56%, 75%, and 84%. The process of synthesizing CZTSSe is the same as that of the previous process showing 12.62% efficiency. When the 5-nm-Al2O3 dot patterning was applied to the Mo surface, we observed that the MoSSe formation was well suppressed under the area coated of 5-nm-Al2O3 film. The self-alignment phenomenon was observed in the back-contact area. CZTSSe was easily formed in the Mo-exposed area, while voids were formed near the Al2O3-coated area. The efficiency of the CZTSSe solar cell decreased when the Al2O3 passivated area increased. The exposure area and pitch of Mo, the collecting path of the hole, and the supplying path of Na seemed to be related to efficiency. Thus, it was suggested that the optimization of the Mo-exposed pattern and the additional Na supply are necessary to develop the optimum self-aligned CZTSSe light absorber.

15.
Nanomaterials (Basel) ; 10(1)2019 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-31878052

RESUMEN

When CZTSSe is synthesized using a metal precursor, large voids of nonuniform size form at Mo back contact side. Herein, we demonstrate that the voids and CZTSSe in the lower part of the CZTSSe double layer can be controlled by using an Al2O3-patterned Mo substrate. The CZTSSe in the lower part self-aligns on the Mo-exposed area, while the voids self-align on the Al2O3-coated area. The origin of the self-alignment is expected to be the difference in bonding characteristics between liquid Sn and the metal or oxide surface, e.g., Al2O3. Good wettability generally forms between nonreactive liquid metals and metal surfaces due to the strong metallic bonding. By contrast, poor wettability generally forms between nonreactive liquid metals and oxide surfaces due to the weak van der Waals bonding between the liquid metal and the oxide layer. When the patterning was added, the device efficiency tended to decrease from 8.6% to 10.5%.

16.
ACS Appl Mater Interfaces ; 11(26): 23160-23167, 2019 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-31252489

RESUMEN

Recently, highly efficient CZTS solar cells using pure metal precursors have been reported, and our group created a cell with 12.6% efficiency, which is equivalent to the long-lasting world record of IBM. In this study, we report a new secondary phase formation mechanism in the back contact interface. Previously, CZTSSe decomposition with Mo has been proposed to explain the secondary phase and void formation in the Mo-back contact region. In our sulfo-selenization system, the formation of voids and secondary phases is well explained by the unique wetting properties of Mo and the liquid metal above the peritectic reaction (η-Cu6Sn5 → ε-Cu3Sn + liquid Sn) temperature. Good wetting between the liquid Sn and the Mo substrate was observed because of strong metallic bonding between the liquid metal and Mo layer. Thus, some ε-Cu3Sn and liquid Sn likely remained on the Mo layer during the sulfo-selenization process, and Cu-SSe and Cu-Sn-SSe phases formed on the Mo side. When bare soda lime glass (SLG) was used as a substrate, nonwetting adhesion was observed because of weak van der Walls interactions between the liquid metal and substrate. The Cu-Sn alloy did not remain on the SLG surface, and Cu-SSe and Cu-Sn-SSe phases were not observed after the final sulfo-selenization process. Additionally, Mo/SLG substrates coated with a thin Al2O3 layer (1-5 nm) were used to control secondary phase formation by changing the wetting properties between Mo and the liquid metal. A 1 nm Al2O3 layer was enough to control secondary phase formation at the CZTSSe/Mo and void/Mo interfaces, and a 2 nm Al2O3 layer was enough to perfectly control secondary phase formation at the Mo interface and Mo-SSe formation.

17.
Materials (Basel) ; 12(24)2019 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-31817704

RESUMEN

Doping is known as an effective way to modify both electrical and thermal transport properties of thermoelectric alloys to enhance their energy conversion efficiency. In this project, we report the effect of Pd doping on the electrical and thermal properties of n-type Cu0.008Bi2Te2.7Se0.3 alloys. Pd doping was found to increase the electrical conductivity along with the electron carrier concentration. As a result, the effective mass and power factors also increased upon the Pd doping. While the bipolar thermal conductivity was reduced with the Pd doping due to the increased carrier concentration, the contribution of Pd to point defect phonon scattering on the lattice thermal conductivity was found to be very small. Consequently, Pd doping resulted in an enhanced thermoelectric figure of merit, zT, at a high temperature, due to the enhanced power factor and the reduced bipolar thermal conductivity.

18.
Sci Rep ; 9(1): 5676, 2019 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-30952879

RESUMEN

During the outbreak of Middle East respiratory syndrome coronavirus(MERS-CoV) in 2015, one hemodialysis patient was infected with MERS-CoV, and the remaining hemodialysis(HD) patients (n = 83) and medical staff (n = 12) had to undergo dialysis treatment in an isolated environment. This study was performed to investigate the effects of stress caused by dialysis treatment under isolation. Plasma samples from the HD patients and medical staff were collected at the time of isolation(M0), the following month(M1), and three months after isolation(M3). Parameters for stress included circulating cell-free genomic DNA(ccf-gDNA), circulating cell-free mitochondria DNA(ccf-mtDNA), and pentraxin-3(PTX-3). Decreased values of Hct, kt/v and ca x p were recovered after the end of two weeks of isolation. The levels of ccf-gDNA and ccf-mtDNA were the highest at M0 and decreased gradually in both HD patients and the medical staff. The normalization of ccf-gDNA and ccf-mtDNA was significantly delayed in HD patients compared with the response in the medical staff. PTX-3 increased only in HD patients and was highest at M0, and it then gradually decreased. Medical isolation and subnormal quality of care during the MERS outbreak caused extreme stress in HD patients. Plasma cell-free DNA and PTX-3 seems to be good indicators of stress and quality of care in HD patients.


Asunto(s)
Biomarcadores/sangre , Ácidos Nucleicos Libres de Células/sangre , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/virología , ADN Mitocondrial/sangre , Coronavirus del Síndrome Respiratorio de Oriente Medio/patogenicidad , Adulto , Infección Hospitalaria/sangre , Infección Hospitalaria/virología , Brotes de Enfermedades , Femenino , Humanos , Masculino , Persona de Mediana Edad , Diálisis Renal/métodos , República de Corea
19.
Nat Commun ; 10(1): 2959, 2019 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-31273214

RESUMEN

For kesterite copper zinc tin sulfide/selenide (CZTSSe) solar cells to enter the market, in addition to efficiency improvements, the technological capability to produce flexible and large-area modules with homogeneous properties is necessary. Here, we report a greater than 10% efficiency for a cell area of approximately 0.5 cm2 and a greater than 8% efficiency for a cell area larger than 2 cm2 of certified flexible CZTSSe solar cells. By designing a thin and multi-layered precursor structure, the formation of defects and defect clusters, particularly tin-related donor defects, is controlled, and the open circuit voltage value is enhanced. Using statistical analysis, we verify that the cell-to-cell and within-cell uniformity characteristics are improved. This study reports the highest efficiency so far for flexible CZTSSe solar cells with small and large areas. These results also present methods for improving the efficiency and enlarging the cell area.


Asunto(s)
Metales/química , Energía Solar , Espectrometría por Rayos X
20.
Sci Rep ; 9(1): 1854, 2019 02 12.
Artículo en Inglés | MEDLINE | ID: mdl-30755622

RESUMEN

Endocan is a water-soluble proteoglycan exclusively secreted by vascular endothelium. Endocan levels may be elevated in kidney transplant recipients experiencing antibody-mediated rejection (ABMR), which is characterized by vascular inflammation in transplanted kidney. We evaluated the clinical relevance of endocan as markers of microvascular inflammation in patients who underwent kidney transplantation. Plasma and urinary endocan levels were measured in 203 kidney transplant recipients and were compared across different etiologies of allograft dysfunction and various pathologic scores. Both plasma and urinary endocan levels were significantly higher in patients with acute ABMR than those in patients with normal pathology, acute tubular necrosis (ATN), acute pyelonephritis, BK virus associated nephropathy (BKVN), and T-cell mediated rejection (TCMR). Patients with chronic active ABMR also exhibited significantly higher plasma and urinary endocan levels than patients with long-term graft survival. Scores of glomerulitis and peritubular capillaritis, which are typical features of microvascular inflammation, were significantly elevated in patients with higher plasma and/or urinary endocan levels. Furthermore, plasma and urinary endocan levels could effectively discriminate ABMR from ATN, BKVN, and TCMR. Finally, patients exhibiting high urinary and plasma endocan levels in acute ABMR group showed significantly worse renal survival. Altogether, plasma and urinary endocan levels may serve as potential markers of microvascular inflammation in kidney transplant recipients.


Asunto(s)
Inflamación/inmunología , Fallo Renal Crónico/cirugía , Trasplante de Riñón , Microcirculación/inmunología , Proteínas de Neoplasias/sangre , Proteínas de Neoplasias/orina , Proteoglicanos/sangre , Proteoglicanos/orina , Adulto , Área Bajo la Curva , Biopsia , Femenino , Rechazo de Injerto , Humanos , Masculino , Persona de Mediana Edad , Necrosis , Infecciones por Polyomavirus/metabolismo , Pielonefritis/inmunología , Curva ROC , Estudios Retrospectivos , Linfocitos T/citología , Receptores de Trasplantes , Resultado del Tratamiento , Infecciones Tumorales por Virus/inmunología
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