Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Polymers (Basel) ; 16(2)2024 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-38256976

RESUMEN

Recent environmental concerns have increased demand for renewable polymers and sustainable green resource usage, such as biomass-derived components and carbon dioxide (CO2). Herein, we present crosslinked polyurethanes (CPUs) fabricated from CO2- and biomass-derived monomers via a facile solvent-free ball milling process. Furan-containing bis(cyclic carbonate)s were synthesized through CO2 fixation and further transformed to tetraols, denoted FCTs, by aminolysis and utilized in CPU synthesis. Highly dispersed polyurethane-based hybrid composites (CPU-Ag) were also manufactured using a similar ball milling process. Due to the malleability of the CPU matrix, enabled by transcarbamoylation (dynamic covalent chemistry), CPU-based composites are expected to present very low interfacial thermal resistance between the heat sink and heat source. The characteristics of the dynamic covalent bond (i.e., urethane exchange reaction) were confirmed by the results of dynamic mechanical thermal analysis and stress relaxation analysis. Importantly, the high thermal conductivity of the CPU-based hybrid material was confirmed using laser flash analysis (up to 51.1 W/m·K). Our mechanochemical approach enables the facile preparation of sustainable polymers and hybrid composites for functional application.

2.
Small ; 19(45): e2303472, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37420329

RESUMEN

The severely insufficient operational lifetime of perovskite light-emitting diodes (LEDs) is incompatible with the rapidly increasing external quantum efficiency, even as it approaches the theoretical limit, thereby significantly impeding the commercialization of perovskite LEDs. In addition, Joule heating induces ion migration and surface defects, degrades the photoluminescence quantum yield and other optoelectronic properties of perovskite films, and induces the crystallization of charge transport layers with low glass transition temperatures, resulting in LED degradation under continuous operation. Here, a novel thermally crosslinked hole transport material, poly(FCA60 -co-BFCA20 -co-VFCA20 ) (poly-FBV), with temperature-dependent hole mobility is designed, which is advantageous for balancing the charge injection of the LEDs and limiting the generation of Joule heating. The optimised CsPbI3 perovskite nanocrystal LEDs with poly-FBV realise approximately a 2-fold external quantum efficiency increase over the LED with commercial hole transport layer poly(4-butyl-phenyl-diphenyl-amine) (poly-TPD), owing to the balanced carrier injection and suppressed exciton quenching. Moreover, because of the Joule heating control provided by the novel crosslinked hole transport material, the LED utilising crosslinked poly-FBV has a 150-fold longer operating lifetime (490 min) than that utilizing poly-TPD (3.3 min). The study opens a new avenue for the use of PNC LEDs in commercial semiconductor optoelectronic devices.

3.
Adv Mater ; 35(8): e2209486, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36496257

RESUMEN

Semiconducting lead halide perovskite nanocrystals (PNCs) are regarded as promising candidates for next-generation optoelectronic devices due to their solution processability and outstanding optoelectronic properties. While the field of light-emitting diodes (LEDs) and photovoltaics (PVs), two prime examples of optoelectronic devices, has recently seen a multitude of efforts toward high-performance PNC-based devices, realizing both devices with high efficiencies and stabilities through a single PNC processing strategy has remained a challenge.  In this work, diphenylpropylammonium (DPAI) surface ligands, found through a judicious ab-initio-based ligand search, are shown to provide a solution to this problem. The universal PNC ink with DPAI ligands presented here, prepared through a solution-phase ligand-exchange process, simultaneously allows single-step processed LED and PV devices with peak electroluminescence external quantum efficiency of 17.00% and power conversion efficiency of 14.92% (stabilized output 14.00%), respectively. It is revealed that a careful design of the aromatic rings such as in DPAI is the decisive factor in bestowing such high performances, ease of solution processing, and improved phase stability up to 120 days. This work illustrates the power of ligand design in producing PNC ink formulations for high-throughput production of optoelectronic devices; it also paves a path for "dual-mode" devices with both PV and LED functionalities.

4.
Nanomaterials (Basel) ; 12(23)2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36500867

RESUMEN

Copper-based nanoparticles have been intensively studied owing to their superior antibacterial activity. In this study, cuprous oxide (Cu2O) nanoparticles were synthesized using two different methods. In particular, two methods for synthesizing copper oxide from NaOH, namely, with and without the addition of NH3, were used to adjust the morphology of the nanoparticles. The nanoparticles from the NH3 and NaOH samples possessed an octahedral morphology. The crystal structure of the samples was confirmed by X-ray diffraction. The size distribution of the NH3 sample was narrower than that of the NaOH sample. Furthermore, the average size of the NH3 sample was smaller than that of the NaOH sample. Unexpectedly, the antibacterial activity of the NH3 sample was found to be lower than that of the NaOH sample. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the adsorbed NH3 caused the surface oxidation of Cu2O nanoparticles with azide (N3) formation on surface.

5.
J Microbiol Biotechnol ; 32(9): 1146-1153, 2022 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-36168203

RESUMEN

Many probiotic species have been used as a fermentation starter for manufacturing functional food materials. We have isolated Bifidobacterium animalis subsp. lactis LDTM 8102 from the feces of infants as a novel strain for fermentation. While Glycine max has been known to display various bioactivities including anti-oxidant, anti-skin aging, and anti-cancer effects, the immune-modulatory effect of Glycine max has not been reported. In the current study, we have discovered that the extract of Glycine max fermented with B. animalis subsp. lactis LDTM 8102 (GFB 8102), could exert immuno-modulatory properties. GFB 8102 treatment increased the production of immune-stimulatory cytokines in RAW264.7 macrophages without any noticeable cytotoxicity. Analysis of the molecular mechanism revealed that GFB 8102 could upregulate MAPK2K and MAPK signaling pathways including ERK, p38, and JNK. GFB 8102 also increased the proliferation rate of splenocytes isolated from mice. In an animal study, administration of GFB 8102 partially recovered cyclophosphamide-mediated reduction in thymus and spleen weight. Moreover, splenocytes from the GFB 8102-treated group exhibited increased TNF-α, IL-6, and IL-1ß production. Based on these findings, GFB 8102 could be a promising functional food material for enhancing immune function.


Asunto(s)
Bifidobacterium animalis , Probióticos , Animales , Antioxidantes/metabolismo , Ciclofosfamida , Citocinas/metabolismo , Humanos , Inmunidad , Interleucina-6/metabolismo , Ratones , Extractos Vegetales/metabolismo , Glycine max/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
6.
ACS Appl Mater Interfaces ; 14(11): 13400-13409, 2022 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-35258925

RESUMEN

Among the solution-processed devices, perovskite solar cells (PSCs) exhibit the highest power conversion efficiency (PCE) of over 25%; tremendous efforts are being undertaken to improve their stability. Recently, all-inorganic CsPbI2Br-based PSCs were reported to exhibit a significantly improved device stability, with a promising PCE of up to 16.79%. In this study, we report stable all-inorganic PSCs by incorporating novel dopant-free hole-transporting materials (HTMs). The synthesis strategy of the newly synthesized polymeric HTMs was similar to that of 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD), with the exception that they were designed to exhibit dopant-free characteristics. In particular, their polymeric backbone structure was significantly simpler than that of spiro-OMeTADs, and they were easily synthesized in two steps from commercially available chemicals, with an overall yield of ∼50%. The cost of synthesis at the laboratory scale was calculated to be at least 2.4 times cheaper than that of spiro-OMeTADs. The PCE of dopant-free HTM-based PSCs was 11.01%, which is 1.5 times higher than that of the dopant-free spiro-OMeTAD-based devices (7.52%) and comparable to that of the doped spiro-OMeTAD-based devices (12.22%). Notably, the stability of the device based on our dopant-free HTM to atmospheric oxygen and moisture as well as heat and light irradiation was superior to that of devices based on doped and dopant-free spiro-OMeTAD HTMs. On consideration of the synthesis cost, device efficiency, and device stability, our dopant-free HTM is highly promising for all-inorganic PSCs.

7.
Sci Rep ; 12(1): 2729, 2022 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-35177737

RESUMEN

Predicting the radiation dose‒toxicity relationship is important for local tumor control and patients' quality of life. We developed a first intuitive evaluation system that directly matches the three-dimensional (3D) dose distribution with the skin surface image of patients with radiation dermatitis (RD) to predict RD in patients undergoing radiotherapy. Using an RGB-D camera, 82 3D skin surface images (3DSSIs) were acquired from 19 patients who underwent radiotherapy. 3DSSI data acquired included 3D skin surface shape and optical imaging of the area where RD occurs. Surface registration between 3D skin dose (3DSD) and 3DSSI is performed using the iterative closest point algorithm, then reconstructed as a two-dimensional color image. The developed system successfully matched 3DSSI and 3DSD, and visualized the planned dose distribution onto the patient's RD image. The dose distribution pattern was consistent with the occurrence pattern of RD. This new approach facilitated the evaluation of the direct correlation between skin-dose distribution and RD and, therefore, provides a potential to predict the probability of RD and thereby decrease RD severity by enabling informed treatment decision making by physicians. However, the results need to be interpreted with caution due to the small sample size.


Asunto(s)
Imagenología Tridimensional , Neoplasias/radioterapia , Dosis de Radiación , Radiodermatitis/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Radioterapia/efectos adversos , Estudios Retrospectivos
8.
J Nanosci Nanotechnol ; 21(7): 4051-4054, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33715743

RESUMEN

The purpose of this study is to investigate the surface activity of starch nanocrystals (SNC), material derived from starch, and confirm their usefulness as a surfactant. In order to evaluate the surface activity, the surface tension change of suspended SNC solution via the Wilhelmy plate method was measured and the values were compared with various synthetic surfactants. The effect of SNC as emulsifier was evaluated on emulsion formation and physical stability. The surface tension of the SNC-dispersed solution was decreased while its concentration was increased. When the 5.0% (w/v) of SNC was added, the surface tension was decreased from 70.3 to 49.5 mN/m. It was confirmed that the physical stability of the emulsion prepared by adding the SNC was improved compared to that of surface inactivity material (PEG 400). The phase separation was observed within 1 hour after preparation of the emulsion containing PEG 400, but the emulsion containing SNC was stable for 5 hours or more. To summarize this study, SNC, a natural-derived and non-toxic material, exhibits sufficient surface activity, thereby confirming the possibility of being applied to the food and pharmaceutical industry.


Asunto(s)
Nanopartículas , Almidón , Emulsionantes , Emulsiones , Tensoactivos
9.
J Nanosci Nanotechnol ; 21(7): 4093-4097, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33715752

RESUMEN

The purpose of this study is to produce nanostructured lipid carrier (NLC) that can solubilize poorly water-soluble velutin and verify an improved tyrosinase synthesis inhibition. A solubility test for velutin was conducted. Cetyl palmitate and caprylic/capric triglyceride were selected as solubilizer. The lipid matrix was produced using the ultrasound dispersion method. The morphology and size distribution of the produced NLC was analyzed through scanning electron microscopy (SEM) and dynamic light scattering (DLS), and the release and tyrosinase inhibition of velutin was evaluated through the Franz diffusion cell method and tyrosinase inhibition assay. Lipid matrix nanoparticles showed an average size of approximately 250 nm and polydispersity of 0.2, and it was confirmed that the velutin incorporated within nanoparticles sustained release at a constant rate over 36 hours. Due to extremely low aqueous solubility, the tyrosinase synthesis inhibition of velutin suspension was 0%, and the value of velutin incorporated within the NLC formulation was greatly improved 56.5% (40 µg/mL). As a result, it was verified that lipid-based NLC nanoparticles are an efficient formulation for the topical delivery of poorly water-soluble flavonoids such as velutin.


Asunto(s)
Nanopartículas , Nanoestructuras , Rastreo Diferencial de Calorimetría , Portadores de Fármacos , Flavonas , Lípidos , Monofenol Monooxigenasa , Tamaño de la Partícula
10.
Environ Pollut ; 267: 115588, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33254601

RESUMEN

Mercury isotope ratios in fish tissues have been used to infer sources and biogeochemical processes of mercury in aquatic ecosystems. More experimental studies are however needed to understand the internal dynamics of mercury isotopes and to further assess the feasibility of using fish mercury isotope ratios as a monitoring tool. We exposed Olive flounder (Paralichthys olivaceus) to food pellets spiked with varying concentrations (400, 1600 ng/g) of methylmercury (MeHg) and inorganic mercury (IHg) for 10 weeks. Total mercury (THg), MeHg concentrations, and mercury isotope ratios (δ202Hg, Δ199Hg, Δ200Hg) were measured in the muscle, liver, kidney, and intestine of fish. Fish fed mercury unamended food pellets and MeHg amended food pellets showed absence of internal δ202Hg and Δ199Hg fractionation in all tissue type. For fish fed IHg food pellets, the δ202Hg and Δ199Hg values of intestine equilibrated to those of the IHg food pellets. Kidney, muscle, and liver exhibited varying degrees of isotopic mixing toward the IHg food pellets, consistent with the degree of IHg bioaccumulation. Liver showed additional positive δ202Hg shifts (∼0.63‰) from the binary mixing line between the unamended food pellets and IHg food pellets, which we attribute to redistribution or biliary excretion of liver IHg with a lower δ202Hg to other tissues. Significant δ202Hg fractionation in the liver and incomplete isotopic equilibration in the muscle indicate that these tissues may not be suitable for source monitoring at sites heavily polluted by IHg. Instead, fish intestine appears to be a more suitable proxy for identifying IHg sources. The results from our study are essential for determining the appropriate fish tissues for monitoring environmental sources of IHg and MeHg.


Asunto(s)
Mercurio , Compuestos de Metilmercurio , Contaminantes Químicos del Agua , Animales , Ecosistema , Monitoreo del Ambiente , Peces , Isótopos de Mercurio
11.
Chemosphere ; 260: 127611, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32758780

RESUMEN

Mercury (Hg) is known as a highly toxic heavy metal, and its toxicity varies depending on its form due to different toxicokinetics between inorganic and organic Hg. Limited information on comparison of Hg toxicity concerning its chemical form by oral exposure is currently available in cultured fishes. Therefore, we conducted a comparative study to have a better understanding of distinct toxic effects between mercuric chloride (HgCl2) and methylmercury chloride (CH3HgCl) in Korean rockfish. The 12-weeks dietary exposure of HgCl2 and CH3HgCl with its graded levels (0.4-6.4 ppm) (2 × 5 factorial design) in the young-of-the-year rockfish (initial weight: 82 ± 0.3 g) resulted in neither interactive nor main effects on whole-organism responses, including growth, feed utilization, and survival. However, the distinct pattern of Hg accumulation between the two forms in dorsal muscle, brain, liver and kidney tissues was observed, showing that the rockfish fed the CH3HgCl-contained diets exhibited the dose-dependent accumulation throughout the sampling points (1, 2, 4, 8, and 12 weeks post feeding), whereas those fed the HgCl2-contained diets did not show such response. The CH3HgCl exposure induced higher oxidative stress and immunotoxicity, reflected by the elevated plasma superoxide dismutase and lysozyme activities, respectively. In addition, the CH3HgCl-induced alteration in plasma measurements, including the plasma aspartate transaminase activity and total protein level was found. Taken together, the dietary exposure of methylmercury chloride had more pronounced toxic effects than mercuric chloride in the young-of-year rockfish, needed to be taken into consideration for regulation of maximum allowed levels for Hg by its chemical form.


Asunto(s)
Cloruro de Mercurio/toxicidad , Compuestos de Metilmercurio/toxicidad , Perciformes/fisiología , Contaminantes Químicos del Agua/toxicidad , Animales , Encéfalo/metabolismo , Dieta , Mercurio/metabolismo , Estrés Oxidativo , Perciformes/metabolismo , República de Corea , Superóxido Dismutasa/metabolismo
12.
Phys Med Biol ; 65(10): 105005, 2020 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-32235068

RESUMEN

An accurate knowledge of in vivo proton dose distribution is key to fully utilizing the potential advantages of proton therapy. Two representative indirect methods for in vivo range verification, namely, prompt gamma (PG) imaging and positron emission tomography (PET), are available. This study proposes a PG-PET system that combines the advantages of these two methods and presents detector geometry and background reduction techniques optimized for the PG-PET system. The characteristics of the secondary radiations emitted by a water phantom by interaction with a 150 MeV proton beam were analysed using Geant4.10.00, and the 2-D PG distributions were obtained and assessed for different detector geometries. In addition, the energy window (EW), depth-of-interaction (DOI), and time-of-flight (TOF) techniques are proposed as the background reduction techniques. To evaluate the performance of the PG-PET system, the 3-D dose distribution in the water phantom caused by two proton beams of energies 80 MeV and 100 MeV was verified using 16 optimal detectors. The thickness of the parallel-hole tungsten collimator of pitch 8 mm and width 7 mm was determined as 200 mm, and that of the GAGG scintillator was determined as 30 mm, by an optimization study. Further, 3-7 MeV and 2-7 MeV were obtained as the optimal EWs when the DOI and both the DOI and TOF techniques were applied for data processing, respectively; the detector performances were improved by about 38% and 167%, respectively, compared with that when applying only the 3-5 MeV EW. In this study, we confirmed that the PG distribution can be obtained by simply combining the 2-D parallel hole collimator and the PET detector module. In the future, we will develop an accurate 3-D dose evaluation technique using deep learning algorithms based on the image sets of dose, PG, and PET distributions for various proton energies.


Asunto(s)
Método de Montecarlo , Tomografía de Emisión de Positrones , Terapia de Protones , Dosis de Radiación , Algoritmos , Humanos , Fantasmas de Imagen , Dosificación Radioterapéutica , Agua
14.
J Korean Med Sci ; 30(5): 598-605, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25931791

RESUMEN

Bacterial infection is an important cause of death in patients with liver cirrhosis. The aim of this study was to investigate the clinical characteristics and prognostic impact of bacterial infection in hospitalized patients with alcoholic liver disease (ALD). We retrospectively analyzed data from 409 patients consecutively admitted to a tertiary referral center with ALD diagnosis. Of a total of 544 admissions, 133 (24.4%) cases presented with bacterial infection, of which 116 were community-acquired whereas 17 were hospital-acquired. The common types of infection were pneumonia (38%), biliary tract infection (17%), soft tissue infection (12%), and spontaneous bacterial peritonitis (9%). Diabetes, serum Na <135 mM/L, albumin <2.5 g/dL, C-reactive protein ≥20 mg/L, systemic inflammatory response syndrome (SIRS) positivity were independently associated with bacterial infection in patients with ALD. Overall 30-day and 90-day mortalities in patients with bacterial infection were significantly (P < 0.001) higher than those without infection (22.3% vs. 5.1% and 32.3% vs. 8.2%, respectively). Furthermore, bacterial infection (HR, 2.2; 95% CI, 1.049-4.579, P = 0.037), SIRS positivity (HR, 2.5; 95% CI, 1.240-4.861, P = 0.010), Maddrey's discriminant function score ≥32 (HR, 2.3; 95% CI, 1.036-5.222, P = 0.041), and hemoglobin <12 g/dL (HR, 2.4; 95% CI, 1.081-5.450, P = 0.032) were independent predictors of short-term mortality. In conclusion, bacterial infection and SIRS positivity predicted short-term prognosis in hospitalized patients with ALD. A thorough evaluation at admission or on clinical deterioration is required to detect possible infection with prompt management.


Asunto(s)
Infecciones Bacterianas/diagnóstico , Hepatopatías Alcohólicas/diagnóstico , Adulto , Anciano , Infecciones Bacterianas/complicaciones , Infecciones Bacterianas/mortalidad , Proteína C-Reactiva/análisis , Candida/aislamiento & purificación , Femenino , Bacterias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/aislamiento & purificación , Hemoglobinas/análisis , Hospitalización , Humanos , Modelos Lineales , Hepatopatías Alcohólicas/complicaciones , Masculino , Persona de Mediana Edad , Pacientes , Pronóstico , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Factores de Riesgo , Albúmina Sérica/análisis , Sodio/sangre , Análisis de Supervivencia , Síndrome de Respuesta Inflamatoria Sistémica/complicaciones , Síndrome de Respuesta Inflamatoria Sistémica/diagnóstico , Centros de Atención Terciaria
15.
Korean J Gastroenterol ; 63(1): 25-31, 2014 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-24463285

RESUMEN

BACKGROUND/AIMS: The frequency of symptomatic acute HAV infections in adulthood are increasing in Korea. This study analyzes the clinical severity in patients with acute HAV infection and investigates risk factors associated with three severe complications: prolonged cholestasis, acute kidney injury, and acute liver failure. METHODS: We performed a retrospective analysis of 726 patients diagnosed from January 2006 to December 2010 at three tertiary hospitals in Jeonbuk Province, Republic of Korea with acute HAV infection. RESULTS: In the group of 726 patients, the mean age was 30.3 years, 426 (58.6%) were male, and 34 (4.7%) were HBsAg positive. Severe complications from acute HAV infection occurred as follows: prolonged cholestasis in 33 (4.6%), acute kidney injury in 17 (2.3%), and acute liver failure in 16 (2.2%). Through multivariate analysis, age ≥40 years (OR 2.63, p=0.024) and peak PT (INR) ≥1.5 (OR 5.81, p=0.035) were found to be significant risk factors for prolonged cholestasis. Age ≥40 years (OR 5.24, p=0.002) and female gender (OR 3.11, p=0.036) were significant risk factors for acute kidney injury. Age ≥40 years (OR 6.91, p=0.002), HBsAg positivity (OR 5.02, p=0.049), and peak total bilirubin (OR 1.11, p=0.001) were significant risk factors for acute liver failure. CONCLUSIONS: Age ≥40 years, female gender, HBsAg positivity, peak PT (INR) ≥1.5, and peak total bilirubin were significant risk factors for severe complications in acute HAV infections.


Asunto(s)
Hepatitis A/diagnóstico , Enfermedad Aguda , Lesión Renal Aguda/complicaciones , Adulto , Colestasis/complicaciones , Femenino , Hepatitis A/complicaciones , Antígenos de Superficie de la Hepatitis B/sangre , Humanos , Fallo Hepático Agudo/complicaciones , Masculino , Persona de Mediana Edad , Oportunidad Relativa , República de Corea , Estudios Retrospectivos , Factores de Riesgo , Centros de Atención Terciaria
16.
J Gastroenterol Hepatol ; 27(11): 1670-4, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22849817

RESUMEN

BACKGROUND AND AIM: Though angiographic embolization (AE) is a type of effective treatment modality for duodenal ulcer bleeding, the optimum time at which to perform the procedure, early or delayed, is unknown. The authors compared the prognosis of early AE (EAE) and delayed AE (DAE) in patients with duodenal ulcer bleeding. METHODS: A total of 54 patients with duodenal ulcer bleeding were evaluated with first-look endoscopy followed by AE. The patients were divided into two groups, the EAE group and DAE group, according to endoscopic attempts to stop the bleeding during the first-look endoscopy. RESULTS: The success rate of AE, rebleeding rate, and number of patients who underwent surgery was not significantly different between the EAE group and DAE group (91.3% vs 93.5%, 21.7% vs 29.0% and 4.3% vs 16.1%, respectively; P > 0.05). With respect to death and intensive care unit (ICU) care rate, multivariate analysis showed more favorable results in the EAE group (0% vs 22.6%, P = 0.016 and 4.3% vs 57.4%, P = 0.003, respectively). Multivariate analysis also showed that prolonged prothrombin time (PT) > 1.2 international normalized ratio and the endoscopic attempt were independent factors associated with ICU care. CONCLUSION: When the AE was performed early with correction for prolonged PT, the patients with duodenal ulcer bleeding had a more favorable prognosis.


Asunto(s)
Úlcera Duodenal/complicaciones , Embolización Terapéutica , Úlcera Péptica Hemorrágica/terapia , Anciano , Angiografía , Distribución de Chi-Cuadrado , Cuidados Críticos , Endoscopía Gastrointestinal , Femenino , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Análisis Multivariante , Úlcera Péptica Hemorrágica/etiología , Tiempo de Protrombina , Radiografía Intervencional , Recurrencia , Estudios Retrospectivos , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento
17.
J Gene Med ; 10(8): 847-54, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18563862

RESUMEN

BACKGROUND: The use of retroviral vectors has shown an actual clinical benefit in a few inherited diseases. However, the occurrence of cases of leukemia after the X-SCID gene therapy trial raised concerns about the safety of insertional mutagenesis inherent to the biology of the retrovirus. Although the retrovirus has long been known to integrate into the host chromosome, and thus have the potential to activate the nearby gene, there has been no convenient method of studying or assaying such a cis-activation phenomenon. METHODS: In the present study, we report an in vitro assay system in which the effect of retroviral integration on the expression of the neighbouring gene can be studied. In this system, a retroviral vector and the neighbouring reporter gene were constructed in a single plasmid as if it had integrated into the chromosome. RESULTS: Using this assay, we found that the full-length long terminal repeat (LTR) could indeed activate the neighbouring gene expression from a distance and the magnitude of its activation was highly increased when this LTR was placed in the vicinity of the transcription start site of the gene, whereas the truncated LTR exerted little influence. CONCLUSIONS: This assay system might provide a useful tool for selecting the appropriate vector structure, as well as for studying the molecular mechanism underlying the cis-activation by the viral LTR.


Asunto(s)
Técnicas de Cultivo de Célula/métodos , Terapia Genética/métodos , Vectores Genéticos , Retroviridae/genética , Activación Transcripcional , Secuencia de Bases , Bioensayo , Cloranfenicol O-Acetiltransferasa/química , Cloranfenicol O-Acetiltransferasa/metabolismo , Células Clonales , ADN/genética , Electroporación , Expresión Génica , Genes Reporteros , Humanos , Células K562 , Datos de Secuencia Molecular , Mutagénesis Insercional , Plásmidos , Regiones Promotoras Genéticas , ARN Mensajero/análisis , Secuencias Repetidas Terminales/genética
18.
Acta Otolaryngol ; 125(10): 1075-9, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16298789

RESUMEN

The results of this study suggest that an altered expression pattern of sulfated glycosaminoglycans (GAGs) in nasal polyp may not function as a charge restriction barrier for vascular permeability, contributing to the leakage of protein and fluid. Sulfated GAGs are found on the vascular endothelial surface and in the extracellular matrix in various tissues and organs, suggesting that these materials constitute a negatively charged screen restricting the movement of circulating plasma molecules. This study was designed to elucidate the distributional characteristics of sulfated GAGs in normal human nasal mucosa and nasal polyp in order to understand their roles in the formation of nasal polyp. The expression and localization of sulfated GAGs in normal human nasal mucosa and nasal polyp were detected light microscopically with the histochemical method using poly-L-lysine-conjugated colloidal gold followed by silver enhancement. Sulfated GAGs in normal human nasal mucosa were distributed in the epithelial layer, vascular endothelial surface, submucosal gland and extracellular matrix. In nasal polyp, intense staining was also seen in the glandular structure and epithelial layer. However, the vascular endothelium and extracellular matrix exhibited either a weak reaction or no reaction.


Asunto(s)
Glicosaminoglicanos/metabolismo , Mucosa Nasal/metabolismo , Pólipos Nasales/metabolismo , Cornetes Nasales/metabolismo , Adulto , Estudios de Casos y Controles , Femenino , Oro , Humanos , Masculino , Persona de Mediana Edad , Polilisina , Coloración y Etiquetado
19.
Acta Otolaryngol ; 125(8): 877-82, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16158536

RESUMEN

CONCLUSIONS: The results of this study indicate that thioredoxin (Trx) and thioredoxin reductase (TrxR) may play a role in the defense of normal human nasal mucosa against external noxious stimuli. Based on the fact that normal nasal mucosa is continuously exposed to inhaled toxicants and contains a considerable number of inflammatory cells, Trx and TrxR may be upregulated even in normal nasal mucosa and perhaps the difference in their expression levels between normal nasal mucosa and nasal polyp, if it exists at all, is small and therefore difficult to detect. Further studies will be needed to clarify the roles of Trx and TrxR in the pathogenesis of nasal polyp. OBJECTIVES: The cellular antioxidant defense system includes thiol-containing proteins such as Trx and TrxR, which have recently attracted much attention due to their strong antioxidant radical quenching capabilities and other important biological functions related to the regulation of the cellular redox state. This study was undertaken to investigate the expression and distribution of Trx and TrxR in normal human nasal mucosa and nasal polyp, and to improve understanding of the significance of the Trx system in these conditions. MATERIAL AND METHODS: The expression and distribution of Trx and TrxR in normal human inferior turbinate mucosa and nasal polyp were investigated using reverse transcriptase polymerase chain reaction (RT-PCR), semiquantitative RT-PCR, Western blotting and immunohistochemistry. RESULTS: mRNAs and protein for both Trx and TrxR were detected in normal human inferior turbinate mucosa and nasal polyp. Semiquantitative RT-PCR and Western blotting revealed that there was no significant difference in the expression levels of Trx and TrxR between inferior turbinate mucosa and nasal polyp. Immunoreactivity for both Trx and TrxR was seen in nasal epithelial cells, glands and vascular endothelium of inferior turbinate mucosa and nasal polyp. Trx and TrxR immunoreactivity was also found in inflammatory infiltrating cells in inferior turbinate mucosa and nasal polyp.


Asunto(s)
Mucosa Nasal/enzimología , Pólipos Nasales/enzimología , Reductasa de Tiorredoxina-Disulfuro/metabolismo , Tiorredoxinas/metabolismo , Adulto , Antioxidantes , Western Blotting , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Masculino , Mucosa Nasal/metabolismo , Pólipos Nasales/metabolismo , Pólipos Nasales/patología , ARN Mensajero/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Reductasa de Tiorredoxina-Disulfuro/genética , Tiorredoxinas/genética , Cornetes Nasales/enzimología , Cornetes Nasales/metabolismo
20.
Ann Vasc Surg ; 16(4): 501-4, 2002 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12098021

RESUMEN

The purpose of this study was to evaluate the result of arteriovenous (A-V) grafting with the deep forearm veins as an outflow system in hemodialysis patients. Between June 1999 and July 2001, 27 A-V grafts consisting of ePTFE and deep forearm veins were constructed in 26 patients. All patients followed up for assessment of all relevant values, and the median follow-up period was 17.3 months. Seven grafts (26%) failed during the follow-up. The patency rates were 93% and 80% at 3 months and 12 months, respectively. No difference in patency rate was found between males and females, or between diabetics and nondiabetics. Graft-related complications, excluding graft thrombosis, occurred in five patients. These included operative wound dehiscence in two cases, a graft infection, a seroma, and a mild hypoperfusion in the hand. We conclude that the early patency rate of A-V graft using the forearm deep veins as an outflow system is very good and that this technique may be a recommended surgical modality for vascular access in patients with exhausted superficial veins.


Asunto(s)
Derivación Arteriovenosa Quirúrgica/métodos , Politetrafluoroetileno/uso terapéutico , Diálisis Renal/instrumentación , Venas/cirugía , Adulto , Anciano , Femenino , Antebrazo , Humanos , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA