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1.
Nano Lett ; 24(1): 74-81, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38148280

RESUMEN

The investigation of twist engineering in easy-axis magnetic systems has revealed remarkable potential for generating topological spin textures. Implementing twist engineering in easy-plane magnets, we introduce a novel approach to achieving fractional topological spin textures, such as merons. Through atomistic spin simulations on twisted bilayer magnets, we demonstrate the formation of a stable double Meron pair, which we refer to as the "Meron Quartet" (MQ). Unlike a single pair, the merons within the MQ exhibit exceptional stability against pair annihilation due to the protective localization mechanism induced by the twist that prevents collision of the Meron cores. Furthermore, we showcase that the stability of the MQ can be enhanced by adjusting the twist angle, resulting in an increased resistance to external perturbations such as external magnetic fields. Our findings highlight the twisted magnet as a promising platform for achieving merons as stable magnetic quasiparticles in van der Waals magnets.

2.
Nano Lett ; 23(13): 6088-6094, 2023 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-37367179

RESUMEN

Twist engineering of van der Waals magnets has emerged as an outstanding platform for manipulating exotic magnetic states. However, the complicated form of spin interactions in the large moiré superlattice obstructs a concrete understanding of such spin systems. To tackle this problem, for the first time, we developed a generic ab initio spin Hamiltonian for twisted bilayer magnets. Our atomistic model reveals that strong AB sublattice symmetry breaking due to the twist introduces a promising route to realize the novel noncentrosymmetric magnetism. Several unprecedented features and phases are uncovered including the peculiar domain structure and skyrmion phase induced by noncentrosymmetricity. The diagram of those distinctive magnetic phases has been constructed, and the detailed nature of their transitions analyzed. Further, we established the topological band theory of moiré magnons relevant to each of these phases. By respecting the full lattice structure, our theory provides the characteristic features that can be detected in experiments.

3.
Sensors (Basel) ; 22(19)2022 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-36236578

RESUMEN

The bidirectional reflectance distribution function (BRDF) is important for estimating the physical properties of a surface in remote sensing. In the laboratory, the BRDF can be estimated quickly and accurately using a goniometer, but it is very difficult to operate in the field. The purpose of this study was to evaluate whether estimating the BRDF with reasonable accuracy using an unmanned aerial vehicle (UAV) with a multispectral camera is possible in the field. Hemispherical reflectance was created from images taken using an UAV multispectral camera. The ground targets were four calibrated reference tarps (CRTs) of different reflectance, and the UAV was operated five times. Down-welling irradiance for reflectance calculation was measured in two ways: a sunlight sensor was mounted on a UAV, and a spectroradiometer with a remote cosine receptor (RCR) was installed on the ground. The BRDF was assessed through the anisotropy factor (ANIF) of the CRT reflectance derived from the collected data. As a result, the irradiance data for the reflectance calculation were more effective from the spectroradiometer with RCR on the ground than from the sunlight sensor mounted on an UAV. Furthermore, the high reflectance CRTs, ANIF, and BRDF had similar results. Therefore, when analyzing the BRDF, the effectiveness can be guaranteed when the reflectance of the target is over 21~46%, because a low reflectance tendency differs due to the adjacency effect. In addition, weather affects irradiance, so it is more effective to conduct fieldwork in clear weather.

4.
Sensors (Basel) ; 21(19)2021 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-34640841

RESUMEN

During the past decade, mobile attacks have been established as an indispensable attack vector adopted by Advanced Persistent Threat (APT) groups. The ubiquitous nature of the smartphone has allowed users to use mobile payments and store private or sensitive data (i.e., login credentials). Consequently, various APT groups have focused on exploiting these vulnerabilities. Past studies have proposed automated classification and detection methods, while few studies have covered the cyber attribution. Our study introduces an automated system that focuses on cyber attribution. Adopting MITRE's ATT&CK for mobile, we performed our study using the tactic, technique, and procedures (TTPs). By comparing the indicator of compromise (IoC), we were able to help reduce the false flags during our experiment. Moreover, we examined 12 threat actors and 120 malware using the automated method for detecting cyber attribution.


Asunto(s)
Seguridad Computacional , Teléfono Inteligente , Atención a la Salud
5.
Child Psychiatry Hum Dev ; 52(3): 399-408, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-32671498

RESUMEN

We aimed to assess cross-cultural differences in depressive symptoms and the validity of the Korean version of the Mood and Feelings Questionnaire (MFQ). Four hundred and sixty-four children and adolescents (aged 7-19, 278 girls) with any psychiatric diagnosis, 290 of whom had major depressive disorder, were included. The levels of depressive symptoms in children and adolescents were evaluated by children/adolescents and their parents. We conducted Pearson's r and Cronbach's α, confirmative factor analysis and item response theory tests. The Korean version of the MFQ demonstrated excellent criterion validity and discriminant validity. There were no cultural differences in the clinical manifestations of depression in youth from Western countries and Korea. Korean youths with depression were more likely to complain of cognitive and emotional symptoms than somatic symptoms. The Korean version of the MFQ demonstrated promising psychometric properties in a clinical sample of children and adolescents.


Asunto(s)
Depresión/diagnóstico , Trastorno Depresivo Mayor/diagnóstico , Adolescente , Afecto , Niño , Comparación Transcultural , Depresión/psicología , Trastorno Depresivo Mayor/psicología , Emociones , Análisis Factorial , Femenino , Humanos , Masculino , Padres , Psicometría , Reproducibilidad de los Resultados , República de Corea , Encuestas y Cuestionarios , Adulto Joven
6.
Pharm Biol ; 59(1): 840-853, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34184969

RESUMEN

CONTEXT: Recently in Korean medicine, the antioxidant and anti-inflammatory activities of Seonghyangjeongki-san (SHJKS) were reported. However, studies on the specific mechanisms of action of SHJKS for the treatment of ischaemic stroke are still lacking. OBJECTIVE: This study investigates the mechanism of action of the water extract methanol fraction of modified SHJKS (SHJKSmex) on cerebral ischaemic injury. MATERIALS AND METHODS: C57BL/6 male mice were orally administered SHJKSmex (30, 100, or 300 mg/kg) for 3 consecutive days (2 days, 1 day, and 1 h, respectively) before middle cerebral artery occlusion (MCAO). Twenty-four hours after MCAO, the infarct volumes were measured, brain edoema indices were calculated, and neurological deficit scores were determined. Inflammation-related substances in the ipsilateral hemisphere were determined by western blotting, dichlorofluorescin diacetate, thiobarbituric acid-reactive substances assay, and enzyme-linked immunosorbent assay. RESULTS: SHJKSmex pre-treatment at 300 mg/kg decreased infarct volume by 87% and mean brain water content by 90% of the MCAO control group. Moreover, SHJKSmex effectively suppressed the expression of inducible nitric oxide synthase, reactive oxygen species, interleukin 1, and caspases-8 and -9 and increased the B-cell lymphoma 2/Bcl-2-associated X protein ratio (Bcl-2/Bax) in ischaemic mouse brain. The hippocampal pyramidal cell densities were significantly increased in the 300 mg/kg SHJKSmex-administered group compared to the MCAO control group. DISCUSSION AND CONCLUSIONS: SHJKSmex protected the brain from ischaemic stroke in mice through its antioxidant, anti-inflammatory, and antiapoptotic activities. Our findings suggest that SHJKSmex is a promising therapeutic candidate for the development of a new formulation for ischaemia-induced brain damage.


Asunto(s)
Ataque Isquémico Transitorio/tratamiento farmacológico , Metanol , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/uso terapéutico , Accidente Cerebrovascular/tratamiento farmacológico , Agua , Animales , Relación Dosis-Respuesta a Droga , Ataque Isquémico Transitorio/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Accidente Cerebrovascular/metabolismo , Resultado del Tratamiento
7.
J Biol Chem ; 288(35): 25400-25413, 2013 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-23888050

RESUMEN

Sox11 deletion mice are known to exhibit developmental defects of craniofacial skeletal malformations, asplenia, and hypoplasia of the lung, stomach, and pancreas. Despite the importance of Sox11 in the developing skeleton, the role of Sox11 in osteogenesis has not been studied yet. In this study, we identified that Sox11 is an important transcription factor for regulating the proliferation and survival of osteoblast precursor cells as well as the self-renewal potency of mesenchymal progenitor cells via up-regulation of Tead2. Furthermore, Sox11 also plays an important role in the segregation of functional osteoblast lineage progenitors from osteochondrogenic progenitors. Facilitation of osteoblast differentiation from mesenchymal cells was achieved by enhanced expression of the osteoblast lineage specific transcription factors Runx2 and Osterix. Morpholino-targeted disruption of Sox11 in zebrafish impaired organogenesis, including the bones, which were under mineralized. These results indicated that Sox11 plays a crucial role in the proliferation and survival of mesenchymal and osteoblast precursors by Tead2, and osteogenic differentiation by regulating Runx2 and Osterix.


Asunto(s)
Diferenciación Celular/fisiología , Proliferación Celular , Células Madre Mesenquimatosas/metabolismo , Osteoblastos/metabolismo , Factores de Transcripción SOXC/metabolismo , Animales , Línea Celular , Supervivencia Celular/fisiología , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Humanos , Células Madre Mesenquimatosas/citología , Ratones , Osteoblastos/citología , Factores de Transcripción SOXC/genética , Factor de Transcripción Sp7 , Factores de Transcripción de Dominio TEA , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Pez Cebra/embriología , Pez Cebra/genética
8.
Artículo en Inglés | MEDLINE | ID: mdl-24462964

RESUMEN

The industrial application of nanotechnology, particularly using zinc oxide (ZnO), has grown rapidly, including products such as cosmetics, food, rubber, paints, and plastics. However, despite increasing population exposure to ZnO, its potential genotoxicity remains controversial. The biological effects of nanoparticles depend on their physicochemical properties. Preparations with well-defined physico-chemical properties and standardized test methods are required for assessing the genotoxicity of nanoparticles. In this study, we have evaluated the genotoxicity of four kinds of ZnO nanoparticles: 20nm and 70nm size, positively or negatively charged. Four different genotoxicity tests (bacterial mutagenicity assay, in vitro chromosomal aberration test, in vivo comet assay, and in vivo micronucleus test, were conducted, following Organization for Economic Cooperation and Development (OECD) test guidelines with good laboratory practice (GLP) procedures. No statistically significant differences from the solvent controls were observed. These results suggest that surface-modified ZnO nanoparticles do not induce genotoxicity in in vitro or in vivo test systems.


Asunto(s)
Daño del ADN , Nanopartículas del Metal/toxicidad , Óxido de Zinc/toxicidad , Animales , Células Cultivadas , Ensayo Cometa/métodos , Cricetinae , Cricetulus , Masculino , Ratones , Ratones Endogámicos ICR , Pruebas de Micronúcleos , Ratas , Ratas Sprague-Dawley
9.
ScientificWorldJournal ; 2014: 541035, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25574486

RESUMEN

This study investigates the effect of a new pore filling material, named sodium silicate-based nanosilica (SS), on resisting the diffusion of the chloride ions. The proposed SS is chosen, mainly due to its smaller particle size, compared to the conventional ethyl silicate-based nanosilica. Each particle of SS is chemically treated to have the negative (-) charge on its surface. Four types of mixes with different amounts of partial replacement with fly ash and slag are prepared. Effect of water to binder ratios (0.35, 0.40, and 0.45) is also examined. Test results showed that the inclusion of SS was significantly beneficial for protecting the concrete from chloride attack. At a given strength, the SS inclusion in concrete was up to three times more effective than the control concrete without SS. It is believed that these excellent results are attributed to the small particle size and the chemical surface treatment of SS. In this study, experiments of compressive strength, hydration heat, accelerated neutralization, and sulfate erosion tests were also conducted to find the general effect of SS inclusion on the fundamental properties and durability of concrete.


Asunto(s)
Cloruros/química , Materiales de Construcción , Nanopartículas/química , Silicatos/química , Dióxido de Silicio/química , Carbonatos/química , Fuerza Compresiva , Esterificación , Calor , Peso Molecular , Nanopartículas/ultraestructura , Sulfatos/química
10.
Mol Metab ; 86: 101969, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38908793

RESUMEN

OBJECTIVES: Cachexia is a metabolic disorder and comorbidity with cancer and heart failure. The syndrome impacts more than thirty million people worldwide, accounting for 20% of all cancer deaths. In acute myeloid leukemia, somatic mutations of the metabolic enzyme isocitrate dehydrogenase 1 and 2 cause the production of the oncometabolite D2-hydroxyglutarate (D2-HG). Increased production of D2-HG is associated with heart and skeletal muscle atrophy, but the mechanistic links between metabolic and proteomic remodeling remain poorly understood. Therefore, we assessed how oncometabolic stress by D2-HG activates autophagy and drives skeletal muscle loss. METHODS: We quantified genomic, metabolomic, and proteomic changes in cultured skeletal muscle cells and mouse models of IDH-mutant leukemia using RNA sequencing, mass spectrometry, and computational modeling. RESULTS: D2-HG impairs NADH redox homeostasis in myotubes. Increased NAD+ levels drive activation of nuclear deacetylase Sirt1, which causes deacetylation and activation of LC3, a key regulator of autophagy. Using LC3 mutants, we confirm that deacetylation of LC3 by Sirt1 shifts its distribution from the nucleus into the cytosol, where it can undergo lipidation at pre-autophagic membranes. Sirt1 silencing or p300 overexpression attenuated autophagy activation in myotubes. In vivo, we identified increased muscle atrophy and reduced grip strength in response to D2-HG in male vs. female mice. In male mice, glycolytic intermediates accumulated, and protein expression of oxidative phosphorylation machinery was reduced. In contrast, female animals upregulated the same proteins, attenuating the phenotype in vivo. Network modeling and machine learning algorithms allowed us to identify candidate proteins essential for regulating oncometabolic adaptation in mouse skeletal muscle. CONCLUSIONS: Our multi-omics approach exposes new metabolic vulnerabilities in response to D2-HG in skeletal muscle and provides a conceptual framework for identifying therapeutic targets in cachexia.

11.
bioRxiv ; 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38948703

RESUMEN

Background: Metabolic remodeling is a hallmark of the failing heart. Oncometabolic stress during cancer increases the activity and abundance of the ATP-dependent citrate lyase (ACL, Acly ), which promotes histone acetylation and cardiac adaptation. ACL is critical for the de novo synthesis of lipids, but how these metabolic alterations contribute to cardiac structural and functional changes remains unclear. Methods: We utilized human heart tissue samples from healthy donor hearts and patients with hypertrophic cardiomyopathy. Further, we used CRISPR/Cas9 gene editing to inactivate Acly in cardiomyocytes of MyH6-Cas9 mice. In vivo, positron emission tomography and ex vivo stable isotope tracer labeling were used to quantify metabolic flux changes in response to the loss of ACL. We conducted a multi-omics analysis using RNA-sequencing and mass spectrometry-based metabolomics and proteomics. Experimental data were integrated into computational modeling using the metabolic network CardioNet to identify significantly dysregulated metabolic processes at a systems level. Results: Here, we show that in mice, ACL drives metabolic adaptation in the heart to sustain contractile function, histone acetylation, and lipid modulation. Notably, we show that loss of ACL increases glucose oxidation while maintaining fatty acid oxidation. Ex vivo isotope tracing experiments revealed a reduced efflux of glucose-derived citrate from the mitochondria into the cytosol, confirming that citrate is required for reductive metabolism in the heart. We demonstrate that YAP inactivation facilitates ACL deficiency. Computational flux analysis and integrative multi-omics analysis indicate that loss of ACL induces alternative isocitrate dehydrogenase 1 flux to compensate. Conclusions: This study mechanistically delineates how cardiac metabolism compensates for suppressed citrate metabolism in response to ACL loss and uncovers metabolic vulnerabilities in the heart.

12.
J Phys Chem B ; 127(44): 9587-9595, 2023 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-37878757

RESUMEN

Time-resolved Fourier transform infrared-attenuated total reflectance spectroscopy (FTIR-ATR) was used to measure diffusion in opaque and translucent samples. FTIR-ATR was used to measure the change in the absorbance near the heated ATR crystal surface. The infrared absorbance was then related to the concentration through the Beer-Lambert law. The sample used is a polymer electrolyte composed of lithium bis-trifluoromethanesulfonylimide (LiTFSI) salt in a block copolymer polystyrene-poly(ethylene oxide) (SEO). A new approach to introduce concentration gradients is presented using a temperature gradient that creates a small salt concentration gradient due to thermally driven mass diffusion (the Soret effect). This first method was compared to a second method that we reported using two laminated polymer electrolyte films of different salt concentrations. The thermal gradient study (method 1) covered three temperature differences of 10, 15, and 20 °C, while the second study (method 2) used three average molar ratios across isothermal temperatures ranging from 80 to 120 °C. The benefits and limitations of the new approach are reported, as is the activation energy for salt diffusion in this and similar SEO electrolytes. Developing new techniques to measure diffusion coefficients effectively will aid in the development of a variety of devices, including solid-state batteries and thermogalvanic cells, that are able to convert waste heat into electricity and improve the efficiency of power-generating systems. FTIR-ATR overcomes previous limitations in experimental techniques measuring diffusion coefficients. The results prove that thermal gradient FTIR-ATR is an effective and repeatable approach for determining Fickian diffusion coefficients in viscoelastic solids.

13.
Biomedicines ; 11(10)2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37893241

RESUMEN

Endometriosis, which is the presence of endometrial stroma and glands outside the uterus, is one of the most frequently diagnosed gynecologic diseases in reproductive women. Patients with endometriosis suffer from various pain symptoms such as dysmenorrhea, dyspareunia, and chronic pelvic pain. The pathophysiology for chronic pain in patients with endometriosis has not been fully understood. Altered inflammatory responses have been shown to contribute to pain symptoms. Increased secretion of cytokines, angiogenic factors, and nerve growth factors has been suggested to increase pain. Also, altered distribution of nerve fibers may also contribute to chronic pain. Aside from local contributing factors, sensitization of the nervous system is also important in understanding persistent pain in endometriosis. Peripheral sensitization as well as central sensitization have been identified in patients with endometriosis. These sensitizations of the nervous system can also explain increased incidence of comorbidities related to pain such as irritable bowel disease, bladder pain syndrome, and vulvodynia in patients with endometriosis. In conclusion, there are various possible mechanisms behind pain in patients with endometriosis, and understanding these mechanisms can help clinicians understand the nature of the pain symptoms and decide on treatments for endometriosis-related pain symptoms.

14.
BMC Genomics ; 13: 163, 2012 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-22554259

RESUMEN

BACKGROUND: As a human replacement, the crab-eating macaque (Macaca fascicularis) is an invaluable non-human primate model for biomedical research, but the lack of genetic information on this primate has represented a significant obstacle for its broader use. RESULTS: Here, we sequenced the transcriptome of 16 tissues originated from two individuals of crab-eating macaque (male and female), and identified genes to resolve the main obstacles for understanding the biological response of the crab-eating macaque. From 4 million reads with 1.4 billion base sequences, 31,786 isotigs containing genes similar to those of humans, 12,672 novel isotigs, and 348,160 singletons were identified using the GS FLX sequencing method. Approximately 86% of human genes were represented among the genes sequenced in this study. Additionally, 175 tissue-specific transcripts were identified, 81 of which were experimentally validated. In total, 4,314 alternative splicing (AS) events were identified and analyzed. Intriguingly, 10.4% of AS events were associated with transposable element (TE) insertions. Finally, investigation of TE exonization events and evolutionary analysis were conducted, revealing interesting phenomena of human-specific amplified trends in TE exonization events. CONCLUSIONS: This report represents the first large-scale transcriptome sequencing and genetic analyses of M. fascicularis and could contribute to its utility for biomedical research and basic biology.


Asunto(s)
Macaca fascicularis/genética , Transcriptoma , Empalme Alternativo , Animales , Elementos Transponibles de ADN , Exones , Femenino , Biblioteca de Genes , Masculino , Modelos Animales , Anotación de Secuencia Molecular , Análisis de Secuencia de ADN
15.
J Gastroenterol Hepatol ; 27(4): 741-5, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21916988

RESUMEN

BACKGROUND AND AIM: Few studies have reported temporal trends in the prevalence of gastroesophageal reflux disease (GERD) and associated health-care utilization in Asia. The aim of this study was to investigate temporal changes in the prevalence of GERD and associated health-care utilization. METHODS: Patients with a primary or secondary disease code for GERD, according to the Korean Standard Classification of Diseases, were defined as having "doctor-diagnosed GERD". The prevalence of GERD from 2005 to 2008 was evaluated using Korean National Health Insurance claim data. Claims for proton pump inhibitors (PPI) over this period were also evaluated. Complications of GERD and health-care utilization characteristics, such as the use of diagnostic tests and prescriptions, were investigated. RESULTS: The prevalence of doctor-diagnosed GERD increased rapidly from 4.6% to 7.3% between 2005 and 2008. Over the same period, the amount of PPI claims increased by 56%. People aged 30-39 years and females had a high frequency of GERD-related visits. Esophageal stricture was rare, and 23% of patients with GERD had peptic ulcers. Endoscopy was used as a diagnostic test in 34% of cases. Seventy-seven percent of patients with GERD were treated with PPI or H(2) receptor antagonists. CONCLUSIONS: The prevalence of GERD increased rapidly from 2005 to 2008. The rapid increase of PPI use reflects the real increase in the prevalence of GERD and demand for health care. Middle-aged people and women had a high frequency of GERD visits. Therefore, GERD might be a significant disease burden in Korea.


Asunto(s)
Reflujo Gastroesofágico/tratamiento farmacológico , Reflujo Gastroesofágico/epidemiología , Seguro de Salud/estadística & datos numéricos , Atención al Paciente/estadística & datos numéricos , Inhibidores de la Bomba de Protones/uso terapéutico , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Estenosis Esofágica/complicaciones , Estenosis Esofágica/epidemiología , Esofagoscopía/estadística & datos numéricos , Femenino , Reflujo Gastroesofágico/complicaciones , Antagonistas de los Receptores H2 de la Histamina/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Atención al Paciente/tendencias , Úlcera Péptica/complicaciones , Úlcera Péptica/epidemiología , Prevalencia , República de Corea/epidemiología , Factores Sexuales , Adulto Joven
16.
J Epidemiol ; 22(6): 508-16, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22955110

RESUMEN

BACKGROUND: Perforated peptic ulcer (PPU) is associated with serious health and economic outcomes. However, few studies have estimated the incidence and health outcomes of PPU using a nationally representative sample in Asia. We estimated age- and sex-specific incidence and short-term mortality from PPU among Koreans and investigated the risk factors for mortality associated with PPU development. METHODS: A retrospective population-based study was conducted from 2006 through 2007 using the Korean National Health Insurance claims database. A diagnostic algorithm was derived and validated to identify PPU patients, and PPU incidence rates and 30-day mortality rates were determined. RESULTS: From 2006 through 2007, the PPU incidence rate per 100 000 population was 4.4; incidence among men (7.53) was approximately 6 times that among women (1.24). Incidence significantly increased with advanced age, especially among women older than 50 years. Among 4258 PPU patients, 135 (3.15%) died within 30 days of the PPU event. The 30-day mortality rate increased with advanced age and reached almost 20% for patients older than 80 years. The 30-day mortality rate was 10% for women and 2% for men. Older age, being female, and higher comorbidity were independently associated with 30-day mortality rate among PPU patients in Korea. CONCLUSIONS: Special attention should be paid to elderly women with high comorbidity who develop PPU.


Asunto(s)
Úlcera Péptica Perforada/epidemiología , Distribución por Edad , Anciano , Anciano de 80 o más Años , Bases de Datos Factuales , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Úlcera Péptica Perforada/mortalidad , República de Corea/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Distribución por Sexo , Factores de Tiempo
17.
Materials (Basel) ; 14(20)2021 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-34683703

RESUMEN

Porous films of metals and metal oxides exhibit larger surface areas and higher reactivities than those of dense films. Therefore, they have gained growing attention as potential materials for use in various applications. This study reports the use of a modified direct current magnetron sputtering method to form porous Zn-ZnO composite films, wherein a subsequent wet post-oxidation process is employed to fabricate pure porous ZnO films. The porous Zn-ZnO composite films were initially formed in clusters, and evaluation of their resulting properties allowed the optimal conditions to be determined. An oxygen ratio of 0.3% in the argon gas flow resulted in the best porosity, while a process pressure of 14 mTorr was optimal. Following deposition, porous ZnO films were obtained through rapid thermal annealing in the presence of water vapor, and the properties and porosities of the obtained films were analyzed. An oxidation temperature of 500 °C was optimal, with an oxidation time of 5 min giving a pure ZnO film with 26% porosity. Due to the fact that the films produced using this method are highly reliable, they could be employed in applications that require large specific surface areas, such as sensors, supercapacitors, and batteries.

18.
J Phys Chem B ; 124(10): 2040-2047, 2020 03 12.
Artículo en Inglés | MEDLINE | ID: mdl-32073855

RESUMEN

The diffusion of a lithium salt through a diblock copolymer electrolyte was studied using vibrational spectroscopy. Lithium bis-trifluoromethylsulfonimide (LiTFSI) was dissolved in a lamellar-structured, high-molecular-weight polystyrene-poly(ethylene oxide) diblock copolymer at various concentrations (0-4.51 molLiTFSI/kgPEO). The diffusion coefficient of LiTFSI was determined from time-resolved Fourier Transform infrared spectroscopy attenuated total reflectance (FTIR-ATR) as a function of the salt concentration. By the application of the Beer-Lambert law, FTIR-ATR was used to detect concentration changes. Mutual diffusion was driven by putting in contact two polymer electrolyte membranes with different salt concentrations. Thus, mutual diffusion coefficients were obtained without the influence of electric fields or electrode interfaces. The accuracy of the simple experimental approach and straightforward analysis was validated by comparison to diffusion coefficients reported from measurements in electrochemical cells. Both methods yield mutual diffusion coefficients of lithium salt that are only weakly (and nonmonotonically) dependent on salt concentration. There is some indication in the spectra that there exist two populations of salt with different dissociation states. This could explain the observed nonmonotonic concentration dependence of the mutual diffusion coefficient of the salt. This hypothesis will be examined quantitatively with complementary measurements in future work.

19.
Rev Sci Instrum ; 90(9): 093904, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31575236

RESUMEN

We report a time-resolved normal-incidence photoemission electron microscope with an imaging time-of-flight detector using ∼7-fs near-infrared laser pulses and a phase-stabilized interferometer for studying ultrafast nanoplasmonic dynamics via nonlinear photoemission from metallic nanostructures. The interferometer's stability (35 ± 6 as root-mean-square from 0.2 Hz to 40 kHz) as well as on-line characterization of the driving laser field, which is a requirement for nanoplasmonic near-field reconstruction, is discussed in detail. We observed strong field enhancement and few-femtosecond localized surface plasmon lifetimes at a monolayer of self-assembled gold nanospheres with ∼40 nm diameter and ∼2 nm interparticle distance. A wide range of plasmon resonance frequencies could be simultaneously detected in the time domain at different nanospheres, which are distinguishable already within the first optical cycle or as close as about ±1 fs around time-zero. Energy-resolved imaging (microspectroscopy) additionally revealed spectral broadening due to strong-field or space charge effects. These results provide a clear path toward visualizing optically excited nanoplasmonic near-fields at ultimate spatiotemporal resolution.

20.
Diabetes Ther ; 10(4): 1271-1282, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31079357

RESUMEN

INTRODUCTION: Teneligliptin, an antidiabetic agent classified as a class III dipeptidyl peptidase-4 (DPP-4) inhibitor, has a unique structural feature that provides strong binding to DPP-4 enzymes. We investigated the efficacy and safety of switching patients with type 2 diabetes mellitus (T2DM) who had inadequate glycemic control on a stable dose of other DPP-4 inhibitors to teneligliptin. METHODS: Patients with T2DM whose glycosylated hemoglobin (HbA1c) levels were ≥ 7% despite taking DPP-4 inhibitors other than teneligliptin, with or without other hypoglycemic agents, for at least 3 months were enrolled. The DPP-4 inhibitors taken before participating in the study were switched to 20 mg qd teneligliptin, and this was to be maintained for 52 weeks. The primary end point was the change in HbA1c levels after 12 weeks. Metabolic parameters including fasting plasma glucose (FPG) and blood lipids were assessed also. To assess safety, adverse and hypoglycemic events were monitored. The data from baseline to week 12 were used for analysis in this interim report. RESULTS: The mean change in HbA1c levels from baseline to week 12 was - 0.44%. At week 12, the percentage of patients achieving HbA1c < 7.0% was 31.6% and that of achieving HbA1c < 6.5% was 11.4%, respectively. In 41.2% of patients, the HbA1c levels decreased by at least 0.5% at 12 weeks. The mean change in FPG levels from baseline to week 12 was - 11.5 mg/dl. No severe hypoglycemia was reported. CONCLUSION: After switching to teneligliptin, HbA1c levels decreased significantly in patients with T2DM inadequately controlled with other DPP-4 inhibitors. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03793023. FUNDING: Handok Inc.

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