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1.
Hum Brain Mapp ; 45(11): e26804, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39126346

RESUMEN

An underlying hypothesis for broad transfer from cognitive training is that the regional brain signals engaged during the training task are related to the transfer tasks. However, it is unclear whether the brain activations elicited from a specific cognitive task can generalize to performance of other tasks, esp. in normal aging where cognitive training holds much promise. In this large dual-site functional magnetic resonance imaging (fMRI) study, we aimed to characterize the neurobehavioral correlates of task-switching in normal aging and examine whether the task-switching-related fMRI-blood-oxygen-level-dependent (BOLD) signals, engaged during varieties of cognitive control, generalize to other tasks of executive control and general cognition. We therefore used a hybrid blocked and event-related fMRI task-switching paradigm to investigate brain regions associated with multiple types of cognitive control on 129 non-demented older adults (65-85 years). This large dataset provided a unique opportunity for a data-driven partial least squares-correlation approach to investigate the generalizability of multiple fMRI-BOLD signals associated with task-switching costs to other tasks of executive control, general cognition, and demographic characteristics. While some fMRI signals generalized beyond the scanned task, others did not. Results indicate right middle frontal brain activation as detrimental to task-switching performance, whereas inferior frontal and caudate activations were related to faster processing speed during the fMRI task-switching, but activations of these regions did not predict performance on other tasks of executive control or general cognition. However, BOLD signals from the right lateral occipital cortex engaged during the fMRI task positively predicted performance on a working memory updating task, and BOLD signals from the left post-central gyrus that were disengaged during the fMRI task were related to slower processing speed in the task as well as to lower general cognition. Together, these results suggest generalizability of these BOLD signals beyond the scanned task. The findings also provided evidence for the general slowing hypothesis of aging as most variance in the data were explained by low processing speed and global low BOLD signal in older age. As processing speed shared variance with task-switching and other executive control tasks, it might be a possible basis of generalizability between these tasks. Additional results support the dedifferentiation hypothesis of brain aging, as right middle frontal activations predicted poorer task-switching performance. Overall, we observed that the BOLD signals related to the fMRI task not only generalize to the performance of other executive control tasks, but unique brain predictors of out-of-scanner performance can be identified.


Asunto(s)
Mapeo Encefálico , Encéfalo , Cognición , Función Ejecutiva , Imagen por Resonancia Magnética , Humanos , Masculino , Femenino , Anciano , Función Ejecutiva/fisiología , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Cognición/fisiología , Anciano de 80 o más Años , Análisis de los Mínimos Cuadrados , Envejecimiento/fisiología , Oxígeno/sangre , Pruebas Neuropsicológicas
2.
Artículo en Inglés | MEDLINE | ID: mdl-38721999

RESUMEN

OBJECTIVES: Older adult executive function varies widely due to brain and cognitive aging. Variance in older adult executive function is linked to increased response conflict from cognitive and brain aging. Cognitive reserve (CR) is a theoretical protective mechanism that lessens brain aging's impact on cognition and is associated with greater educational attainment. Recent work in rest-state functional magnetic resonance imaging (fMRI) suggests CR proxies moderate the relationship between functional connectivity (FC) and cognitive performance. Brain network FC in "control networks," including the salience (SN), dorsal attention and frontoparietal networks, are associated with cognitive processes in older adults. CR is hypothesized to maintain cognitive processing in part through changes in how brain networks respond to cognitive demands. However, it is unclear how CR proxies like educational attainment are related to control network FC during performance when cognitive demands are increased relative to rest. Because CR is expressed more in those with higher education, we hypothesized stronger control network FC would relate to better performance, where this relationship would be strongest among the most educated. METHODS: We collected flanker task data during fMRI to assess the impact of a CR proxy (i.e., educational attainment) on response conflict among older adult subjects (n = 42, age = 65-80). RESULTS: Linear mixed-effects models showed more educated older adults with greater SN-FC had a smaller flanker effect (i.e., less influence of distractors; p < .001) during task performance. DISCUSSION: For the first time, we show that educational attainment moderates the relationship between task-state SN-FC and executive function among older adults.


Asunto(s)
Reserva Cognitiva , Escolaridad , Función Ejecutiva , Imagen por Resonancia Magnética , Humanos , Masculino , Anciano , Femenino , Función Ejecutiva/fisiología , Reserva Cognitiva/fisiología , Encéfalo/fisiología , Encéfalo/diagnóstico por imagen , Red Nerviosa/fisiología , Red Nerviosa/diagnóstico por imagen , Conflicto Psicológico , Envejecimiento Cognitivo/fisiología , Envejecimiento Cognitivo/psicología , Anciano de 80 o más Años
3.
Artículo en Inglés | MEDLINE | ID: mdl-38686621

RESUMEN

OBJECTIVES: Cognitive training (CT) has been investigated as a means of delaying age-related cognitive decline in older adults. However, its impact on biomarkers of age-related structural brain atrophy has rarely been investigated, leading to a gap in our understanding of the linkage between improvements in cognition and brain plasticity. This study aimed to explore the impact of CT on cognitive performance and brain structure in older adults. METHODS: One hundred twenty-four cognitively normal older adults recruited from 2 study sites were randomly assigned to either an adaptive CT (n = 60) or a casual game training (active control, AC, n = 64). RESULTS: After 10 weeks of training, CT participants showed greater improvements in the overall cognitive composite score (Cohen's d = 0.66, p < .01) with nonsignificant benefits after 6 months from the completion of training (Cohen's d = 0.36, p = .094). The CT group showed significant maintenance of the caudate volume as well as significant maintained fractional anisotropy in the left internal capsule and in left superior longitudinal fasciculus compared to the AC group. The AC group displayed an age-related decrease in these metrics of brain structure. DISCUSSION: Results from this multisite clinical trial demonstrate that the CT intervention improves cognitive performance and helps maintain caudate volume and integrity of white matter regions that are associated with cognitive control, adding to our understanding of the changes in brain structure contributing to changes in cognitive performance from adaptive CT. CLINICAL TRIAL REGISTRATION: NCT03197454.


Asunto(s)
Encéfalo , Humanos , Masculino , Anciano , Femenino , Encéfalo/diagnóstico por imagen , Envejecimiento/fisiología , Envejecimiento/psicología , Envejecimiento/patología , Cognición/fisiología , Atrofia , Biomarcadores , Disfunción Cognitiva/diagnóstico por imagen , Terapia Cognitivo-Conductual/métodos , Imagen por Resonancia Magnética , Envejecimiento Cognitivo/fisiología , Envejecimiento Cognitivo/psicología , Plasticidad Neuronal/fisiología , Entrenamiento Cognitivo
4.
J Air Waste Manag Assoc ; 73(2): 133-145, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36399642

RESUMEN

Regulatory agencies and civil society organizations concerned with radioactive waste management are demanding maximized safety management of radioactive-waste-containing drums using advanced technology for more efficient and safe management. In the present paper, we propose a sensor system that can track and monitor drums containing low- and intermediate-level radioactive waste using advanced technology based on the Internet of Things (IoT). The proposed system consists of drum nodes, pallet nodes, and gateways. A drum node and magnetic sensor installed on a drum can be used to remotely check whether the drum lid is open or closed, and the location of the drum can be tracked using a near-field communication reader and an infrared module installed on the pallet node. Considering that radioactive waste is stored for a long time period, the proposed sensors are designed for low power consumption. Moreover, a pilot test involving 48 drums and 12 pallets was conducted to verify the system prototype. Accordingly, from the results of the pilot test, drawbacks were noted and solutions were proposed to improve the system in future work. Implications: We designed a test bed by fabricating a sensor-system prototype and used it in a simulation experiment. The results of this study will be used as basic data for establishing safety measures for radioactive waste management in the future through computer simulation of radioactive waste anomalies in a digital-twin system.


Asunto(s)
Residuos Radiactivos , Administración de Residuos , Residuos Radiactivos/prevención & control , Residuos Radiactivos/análisis , Simulación por Computador
5.
Toxics ; 10(3)2022 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-35324745

RESUMEN

The present study aimed to evaluate the utility of the cement solidification process for stably disposing of waste ion exchange resin generated during the treatment of radioactive wastewater. The cement solidification process using the in-drum mixing system was selected to be used for the solidification process of waste ion exchange resins. The disposal safety of waste forms was evaluated according to the waste acceptance criteria (WAC) applicable to domestic waste disposal sites, and the tests were conducted for six test items provided in the WAC. A total of 15 representative samples were collected from the waste-form drums produced using the optimum operating conditions, and their structural stability for disposal considerations was evaluated. In addition, the leaching index of the samples was 11.05, 10.12, 8.39 for Co, Sr, and Cs, respectively, and it was found to exceed 6, the leaching index standard of WAC. The results confirmed that cement waste forms including waste ion exchange resins produced through this process were considered to be conforming to the requirements for disposal safety.

6.
Materials (Basel) ; 15(3)2022 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-35160818

RESUMEN

The Korea Atomic Energy Research Institute (KAERI) obtains UO2 powder using the ammonium uranyl carbonate (AUC) wet process. Hydrated lime (Ca(OH)2) is used to neutralize liquid wastes produced from the AUC process, and the resulting byproduct is known as lime waste. The purpose of this study is to determine optimum operating conditions for cementation of radioactive lime waste produced from the AUC process, and to evaluate the structural stability and leaching stability of cement waste form. The waste acceptance criteria (WAC) of a waste disposal facility in Korea were used to evaluate the cement waste form samples. The maximum lime waste content guaranteeing the shape stability of cement waste form was found to be 80 wt.% or less. Considering the economic feasibility and error of the cementation process, the optimum operating conditions were achieved at a lime waste content of 75 wt.% and a water-to-cement (w/c) ratio of 2.0. The compressive strength of cement waste form samples prepared under optimal operating conditions was 61.4, 76.3, and 61.0 kgf/cm2 after the thermal cycling test, water immersion test, and irradiation, respectively, satisfying the compressive strength of 35.2 kgf/cm2 specified in WAC. A leaching test was performed on the samples, and the leachability indexes (LX) of Cs, Sr, and Co nuclides were 7.63, 8.02, and 10.89, respectively, which are all higher than the acceptance criterion of 6. The results showed that the cement waste forms prepared under optimal operating conditions satisfied the WAC in terms of structural stability and leaching stability. As such, the proposed cement solidification method for lime waste disposal can be effective in solidifying lime waste powder produced during the neutralization of liquid wastes in the AUC process.

7.
Environ Technol ; 43(15): 2241-2251, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33393440

RESUMEN

A method of chemically bonding copper ferrocynide (CuFC) to the surface of a PVDF hollow-fibre membrane (PVDF-CuFC) was designed and the resulting PVDF-CuFC was applied to the effective removal of aqueous cesium (Cs). In order to chemically immobilize CuFC on the surface of the PVDF hollow-fibre membrane, carboxyl groups were introduced onto the membrane surface (PVDF-COOH) to peptide bond with amine groups from CuFC. The introduction of the carboxyl group onto the surface of the PVDF hollow-fibre membrane was confirmed by Fourier-transform infrared spectroscopy (FT-IR), while the immobilization of CuFC was confirmed by scanning electron microscopy with energy dispersed spectroscopy, FT-IR, and thermogravimetric analysis. The PVDF-CuFC showed higher Cs adsorption kinetics and adsorption capacity than PVDF-COOH. Moreover, as the initial pH increased, the amount of Cs adsorption by PVDF-CuFC also increased. However, the amount of Cs adsorption at pH 10 was slightly less. The applicability of PVDF-CuFC as a filter type adsorbent for the treatment of a Cs-contaminated water source is demonstrated by continuous filtration experiments.


Asunto(s)
Cesio , Contaminantes Químicos del Agua , Adsorción , Cesio/química , Ferrocianuros , Polímeros de Fluorocarbono , Cinética , Polivinilos , Espectroscopía Infrarroja por Transformada de Fourier , Agua/química , Contaminantes Químicos del Agua/química
8.
Adv Mater ; 33(40): e2102980, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34423469

RESUMEN

Optogenetics refers to a technique that uses light to modulate neuronal activity with a high spatiotemporal resolution, which enables the manipulation of learning and memory functions in the human brain. This strategy of controlling neuronal activity using light can be applied for the development of intelligent systems, including neuromorphic and in-memory computing systems. Herein, a flexible van der Waals (vdW) optoelectronic synapse is reported, which is a core component of optogenetics-inspired intelligent systems. This synapse is fabricated on 2D vdW layered rhenium disulfide (ReS2 ) that features an inherent photosensitive memory nature derived from the persistent photoconductivity (PPC) effect, successfully mimicking the dynamics of biological synapses. Based on first-principles calculations, the PPC effect is identified to originate from sulfur vacancies in ReS2 that have an inherent tendency to form shallow defect states near the conduction band edges and under optical excitation lead to large lattice relaxation. Finally, the feasibility of applying the synapses in optogenetics-inspired intelligent systems is demonstrated via training and inference tasks for the CIFAR-10 dataset using a convolutional neural network composed of vdW optoelectronic synapse devices.


Asunto(s)
Electrónica , Redes Neurales de la Computación , Optogenética , Biomimética/instrumentación , Biomimética/métodos , Conductividad Eléctrica , Luz , Renio/química , Sulfuros/química , Sinapsis/fisiología
9.
Environ Sci Pollut Res Int ; 28(31): 42014-42023, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33797045

RESUMEN

Composite beads consisting of Ca alginate mixed with zinc ferrocyanide (ZnFC) and Cyanex 272 were synthesized in order to selectively adsorb Cs+ and Co2+ from water. Their physicochemical properties of the synthesized composite beads were characterized using various techniques, including FESEM, EDX, FTIR, and TGA. The ZnFC/Cyanex 272/alginate (ZCA) composite beads were then tested as an adsorbent for the selective removal of Cs+ and Co2+ from an aqueous solution. The adsorption capacity increased with increasing ZnFC and Cyanex 272 contents. The adsorption process followed the Langmuir model and pseudo-second-order kinetics. The ZCA composite beads exhibited excellent selectivity toward Cs+ and Co2+ even in the presence of competitive cations (K+, Na+, Fe2+, and Ni2+). The adsorption capacity of the ZCA composite beads for Cs+ and Co2+ was almost maintained after three times of adsorption-desorption process.


Asunto(s)
Alginatos , Contaminantes Químicos del Agua , Adsorción , Cesio , Cobalto , Ferrocianuros , Concentración de Iones de Hidrógeno , Cinética , Ácidos Fosfínicos , Agua , Contaminantes Químicos del Agua/análisis , Zinc
10.
J Gerontol B Psychol Sci Soc Sci ; 75(6): 1144-1154, 2020 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-31140569

RESUMEN

OBJECTIVES: We examined whether a home-based, adaptive cognitive training (CT) program would lead to cognitive performance changes on a neuropsychological test battery in cognitively normal older adults. METHOD: Sixty-eight older adults (age = 70.0, SD = 3.74) were randomly assigned to either CT or an active control group (AC, casual computer games). Participants were instructed to train on their assigned programs for 42 min per day, 5 days per week, over 10 weeks (35 hr of total program usage). Participants completed tests of processing speed, working memory, and executive control before and after 10 weeks of training. RESULTS: Training groups did not differ in performance before training. After training, CT participants out-performed AC participants in the overall cognitive composite score, driven by processing speed and working memory domains. DISCUSSION: Our results show that a limited dose of home-based CT can drive cognitive improvements as measured with neuropsychological test battery, suggesting potential cognitive health maintenance implications for cognitively normal older adults.


Asunto(s)
Cognición , Terapia Cognitivo-Conductual/métodos , Disfunción Cognitiva/prevención & control , Función Ejecutiva , Servicios de Atención de Salud a Domicilio , Intervención basada en la Internet , Memoria a Corto Plazo , Pruebas Neuropsicológicas , Anciano , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Femenino , Humanos , Masculino , Procesos Mentales , Evaluación de Resultado en la Atención de Salud , Juegos de Video
11.
Invest Ophthalmol Vis Sci ; 57(15): 6580-6590, 2016 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-27918832

RESUMEN

Purpose: To investigate the ocular immune response following exposure to airborne titanium dioxide (TiO2) microparticles. Methods: Rats in the TiO2-exposed group (n = 10) were exposed to TiO2 particles for 2 hours twice daily for 5 days, while the controls (n = 10) were not. Corneal staining score and tear lactic dehydrogenase (LDH) activity were measured to evaluate ocular surface damage, serum immunoglobulin (Ig) G and E were assayed by using enzyme-linked immunosorbent assay, and the size of cervical lymph nodes was measured. In addition, the expression of interleukin (IL)-4, IL-17, and interferon (IFN)-γ in the anterior segment of the eyeball and cervical lymph nodes was measured by immunohistochemistry, real-time reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analysis. Results: Median corneal staining score (3.0), tear LDH activity (0.24 optical density [OD]), and cervical lymph node size (36.9 mm2) were significantly higher in the TiO2-exposed group than in the control group (1.0, 0.13 OD, and 26.7 mm2, respectively). Serum IgG and IgE levels were found to be significantly elevated in the TiO2-exposed group (P = 0.021 and P = 0.021, respectively). Interleukin 4 expression was increased in the anterior segment of the eyeball and lymph nodes following TiO2 exposure, as measured by immunostaining, real-time RT-PCR, and Western blot. In addition, IL-17 and IFN-γ levels were also increased following TiO2 exposure compared to controls as measured by immunostaining. Conclusions: Exposure to airborne TiO2 induced ocular surface damage. The Type 2 helper T-cell pathway seems to play a dominant role in the ocular immune response following airborne TiO2 exposure.


Asunto(s)
Citocinas/genética , Oftalmopatías/inducido químicamente , Ojo/metabolismo , Inmunidad Celular , Ganglios Linfáticos/metabolismo , Material Particulado/efectos adversos , Titanio/efectos adversos , Animales , Western Blotting , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Ensayo de Inmunoadsorción Enzimática , Ojo/efectos de los fármacos , Oftalmopatías/metabolismo , Oftalmopatías/patología , Regulación de la Expresión Génica/efectos de los fármacos , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/patología , Masculino , Nanopartículas , Cuello , ARN/genética , Ratas , Ratas Endogámicas Lew , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Lágrimas/metabolismo , Células Th2/inmunología
12.
J Nanosci Nanotechnol ; 16(6): 6223-30, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27427694

RESUMEN

The copper ferrocyanide functionalized core-shell magnetic silica composite (mag@silica-CuFC) was prepared and was found to be easily separated from aqueous solutions by using magnetic field. The synthesized mag@silica-CuFC composite has a high sorption ability of Cs owing to its strong affinity for Cs as well as the high surface area of the supports. Cs sorption on the mag@silica-CuFC composite quickly reached the sorption equilibrium after 2 h of contact time. The effect of the presence of salts with a high concentration of up to 3.5 wt% on the efficiency of Cs sorption onto the composites was also studied. The maximum sorption ability was found to be maintained in the presence of up to 3.5 wt% of NaCl in the solution. Considering these results, the mag@silica-CuFC composite has great potential for use as an effective sorbent for the selective removal of radioactive Cs ions.


Asunto(s)
Cesio/aislamiento & purificación , Ferrocianuros/química , Imanes/química , Residuos Radiactivos/análisis , Dióxido de Silicio/química , Adsorción , Cesio/química , Cinética , Nanopartículas/química , Porosidad , Cloruro de Sodio/química , Agua/química
13.
J Craniofac Surg ; 26(7): 2207-11, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26468811

RESUMEN

PURPOSE: To compare the effects of 2 nasal packing materials, synthetic polyurethane foam (absorbable) and expandable polyvinyl acetate (nonabsorbable), on the surgical success rate and postoperative complications after endoscopic endonasal dacryocystorhinostomy (EDCR). METHODS: A retrospective medical review of 459 patients (580 eyes) who underwent EDCR for primary acquired nasolacrimal duct obstruction at Korea University Guro Hospitals from January 2009 to February 2014. Surgical success rate (anatomical, functional), postoperative complications (granuloma, synechia, bleeding, and infection) were compared between the 2 groups, absorbable (318 eyes) and nonabsorbable (262 eyes). RESULTS: The absorbable group showed better results in surgical success rate regarding anatomical (90.5% versus 76.3%, P = 0.00) and functional (89.3% versus 75.9%, P = 0.00). Granulomas developed less frequently in the absorbable group (24.5% versus 38.9%, P = 0.00). Also, bleeding and crust were less frequent in the absorbable group (P = 0.00). Infections were less frequent in the nonabsorbable group (1.52%) compared with the absorbable group (7.86%, P = 0.00). The rate of revision surgery was lower in the absorbable group (7.86% versus 20.9%, P = 0.00). As for the influence of secondary outcomes to the surgical success by multiple logistic regression, granulomas had the largest effect on surgical success either anatomical or functional (odds ratio = 82.393 to anatomical and 44.058 to functional). Synechia had the second largest effect on surgical success (odds ratio = 11.897 to anatomical and 9.605 to functional). CONCLUSIONS: The authors suggest that using a synthetic polyurethane foam as a nasal packing material is not only a surgical option, but also a crucial and essential procedure in EDCR.


Asunto(s)
Materiales Biocompatibles/uso terapéutico , Dacriocistorrinostomía/métodos , Endoscopía/métodos , Poliuretanos/uso terapéutico , Tampones Quirúrgicos , Implantes Absorbibles , Adulto , Anciano , Epistaxis/prevención & control , Femenino , Estudios de Seguimiento , Formaldehído/uso terapéutico , Granuloma/prevención & control , Hemostáticos/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Nasales/prevención & control , Alcohol Polivinílico/uso terapéutico , Polivinilos/uso terapéutico , Complicaciones Posoperatorias/prevención & control , Hemorragia Posoperatoria/prevención & control , Reoperación , Estudios Retrospectivos , Infección de la Herida Quirúrgica/prevención & control , Adherencias Tisulares/prevención & control , Resultado del Tratamiento
14.
J Craniofac Surg ; 26(4): e308-11, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26080243

RESUMEN

PURPOSE: To evaluate the prevalence of oculoplastic surgeries performed in a tertiary hospital in South Korea and to highlight the proper choice of surgery according to disease. METHOD: Retrospective chart review was conducted over a 12-month period (March 2013 to February 2014) on all of the patients who underwent oculoplastic and reconstructive surgery by a single oculoplastic specialist with 15 years' experience. RESULTS: A total of 656 patients were enrolled in the current study. Of them, 355 patients (54.1%) had eyelid surgery, 151 patients (23.0%) had orbital surgery, and 150 patients (22.8%) had lacrimal surgery. Orbital surgery was more commonly performed in men (122 male patients versus 29 female patients, P = 0.00 by Pearson chi-squared test) and was also more common in younger patients than in other surgery groups (56.3 years in eyelid surgery versus 39.3 years in orbital surgery versus 46.9 years in lacrimal surgery, P = 0.001 by Pearson chi-squared test). Blepharoplasty was the most common eyelid surgery, contributing 24.2% of total eyelid surgeries, followed by lid mass excision (68 patients, 19.1%), Hotz operation (59 patients, 16.6%), and levator advancement (47 patients, 13.2%). Among orbital surgeries, reconstruction of orbital wall fractures was the most common, and was performed in 89 patients (58.9%) of total orbital surgeries, followed by orbital tumor debulking surgery (25 patients, 16.5%) and orbital decompression for dysthyroid optic neuropathy (19 patients, 12.5%). Endoscopic endonasal dacryocystorhinostomy (DCR) was the most common lacrimal surgery (84 patients), occurring in 56% of total lacrimal surgeries, followed by Monoka tube intubation (16 patients, 10.6%) for congenital nasolacrimal duct obstruction and conjunctivo-DCR using Jones tube (12 patients, 8%). CONCLUSIONS: Eyelid-related conditions, especially cosmetic blepharoplasty, were among the most commonly encountered surgeries in the Oculoplastics Department of a tertiary care hospital in South Korea. Blowout fracture repair and endoscopic DCR were the most common in orbital and lacrimal surgery. The authors hope that the current survey will contribute to the surgical training of ophthalmology residents and, on a larger scale, health care policies.


Asunto(s)
Blefaroplastia/métodos , Descompresión Quirúrgica/métodos , Enfermedades de los Párpados/epidemiología , Enfermedades del Aparato Lagrimal/epidemiología , Procedimientos Quirúrgicos Oftalmológicos/estadística & datos numéricos , Enfermedades Orbitales/epidemiología , Adolescente , Adulto , Enfermedades de los Párpados/cirugía , Femenino , Humanos , Enfermedades del Aparato Lagrimal/cirugía , Masculino , Persona de Mediana Edad , Enfermedades Orbitales/cirugía , Prevalencia , Estudios Prospectivos , República de Corea/epidemiología , Estudios Retrospectivos
15.
Lasers Med Sci ; 29(4): 1417-27, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24570086

RESUMEN

Nonlinear multiphoton absorption induced by focusing near infrared (NIR) femtosecond (fs) laser pulses into a transparent cornea allows surgery on neovascular structures with minimal collateral damage. In this report, we introduce an fs laser-based microsurgery for selective treatment of rat corneal neovascularizations (in vivo). Contiguous tissue effects are achieved by scanning a focused laser pulse below the corneal surface with a fluence range of 2.2-8.6 J/cm(2). The minimal visible laser lesion (MVL) threshold determined over the corneal neovascular structures was found to be 4.3 J/cm(2). Histological and optical coherence tomography examinations of the anterior segment after laser irradiations show localized degeneration of neovascular structures without any unexpected change in adjacent tissues. Furthermore, an approximately 30 % reduction in corneal neovascularizations was observed after 5 days of fs laser exposure. The femtosecond laser is thus a promising tool for minimally invasive intrastromal surgery with the aid of a significantly smaller and more deterministic photodisruptive energy threshold for the interaction between the fs laser pulse and corneal neovascular structures.


Asunto(s)
Córnea/irrigación sanguínea , Neovascularización de la Córnea/cirugía , Terapia por Láser/métodos , Láseres de Estado Sólido/uso terapéutico , Animales , Córnea/patología , Córnea/cirugía , Microcirugia , Ratas
16.
PLoS One ; 8(9): e72666, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24039791

RESUMEN

INTRODUCTION: There is a growing trend of inactivity among children, which may not only result in poorer physical health, but also poorer cognitive health. Previous research has shown that lower fitness has been related to decreased cognitive function for tasks requiring perception, memory, and cognitive control as well as lower academic achievement. PURPOSE: To investigate the relationship between aerobic fitness, learning, and memory on a task that involved remembering names and locations on a fictitious map. Different learning strategies and recall procedures were employed to better understand fitness effects on learning novel material. METHODS: Forty-eight 9-10 year old children (n = 24 high fit; HF and n = 24 low fit; LF) performed a task requiring them to learn the names of specific regions on a map, under two learning conditions in which they only studied (SO) versus a condition in which they were tested during study (TS). The retention day occurred one day after initial learning and involved two different recall conditions: free recall and cued recall. RESULTS: There were no differences in performance at initial learning between higher fit and lower fit participants. However, during the retention session higher fit children outperformed lower fit children, particularly when the initial learning strategy involved relatively poor recall performance (i.e., study only versus test-study strategy). CONCLUSIONS: We interpret these novel data to suggest that fitness can boost learning and memory of children and that these fitness-associated performance benefits are largest in conditions in which initial learning is the most challenging. Such data have important implications for both educational practice and policy.


Asunto(s)
Aprendizaje , Memoria , Aptitud Física , Niño , Femenino , Humanos , Masculino , Recuerdo Mental , Reconocimiento en Psicología , Reproducibilidad de los Resultados
17.
Korean J Anesthesiol ; 64(2): 138-42, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23459631

RESUMEN

BACKGROUND: Postoperative sore throat (POST) is considered a usual complication after tracheal intubation, especially, thyroid surgery. Gabapentin is a widely studied multimodal perioperative drug, which can be used to treat acute postoperative pain. The primary endpoints of this study was a reduction of the incidence of POST at rest and during the swallowing movements after thyroid surgery. And the second endpoints was a reduction of the intensity of the POST after thyroid surgery. METHODS: Seventy-one patients that underwent elective thyroid surgery received either gabapentin (Neurontin™ 600 mg) or placebo, orally, one hour before anesthesia. The VAS scores and incidences of POST and adverse effects were determined at 1 hr, 6 hr, 12 hr, and 24 hr after surgery at rest and during swallowing movement. RESULTS: The gabapentin group (N = 36) showed a lower incidence of POST than the placebo group (N = 35) (47% vs. 78%, P = 0.038), and had significant lower VAS score at 6 and 24 hours after surgery in the resting state. However, during the movement, no intergroup differences were found in terms of the incidence of POST (83% vs. 91%, P = 0.305) or VAS score. Furthermore, no significant difference was observed between the two groups, in adverse effects. CONCLUSIONS: Gabapentin (Neurontin™ 600 mg) administered 1 hr before anesthesia reduced the intensity and incidence of POST during the resting state without a significant adverse event, during the 24 hr after thyroid surgery. However, gabapentin did not reduce the intensity and incidence of POST during the swallowing movement.

18.
Korean J Thorac Cardiovasc Surg ; 45(1): 60-4, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22363912

RESUMEN

A large cell neuroendocrine carcinoma (LCNEC) of the thymus is a very rare malignant tumor that has a very poor prognosis. The detailed clinical features of LCNEC are still unknown, including the long term prognoses and the definitive modalities of the treatment for LCNEC of the thymus. We are reporting 2 cases of an enlarged LCNEC of the thymus, both of which were diagnosed and treated by surgical resection followed by postoperative adjuvant chemoradiation therapy. Although recurrences and metastases of the LCNEC were noticed 1 and 4 years postoperatively for each case, aggressive surgical resection and adjuvant chemoradiation therapy may be helpful for a patient's long term survival.

19.
Korean J Anesthesiol ; 61(2): 112-6, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21927679

RESUMEN

BACKGROUND: General anesthesia often produces some degree of hypothermia and hypothermia causes much more blood loss during surgery than normothermia. Electrically heated humidifiers (EHHs) have been used for patients under general anesthesia and in the intensive care unit. However, the benefits of the EHH have not been widely reported in the literature. METHODS: Patients scheduled for posterior lumbar spine fusion, were randomly assigned to a mechanically ventilated with EHH circuit group or to a conventional respiratory circuit group. Their tympanic membrane temperature was monitored every 30 min after induction up to 180 min, and perioperative blood losses, transfusion requirements during surgery, and other complications were noted. RESULTS: Patients in the control group (n = 40) showed a lower mean body temperature at all times than immediately after induction, while the EHH group (n = 40) showed a lower body temperature from 60 minute after induction comparing to the initial temperature. Furthermore, patients in the EHH group had a higher mean body temperature than patients in the control group during surgery (35.9 ± 0.4 vs 35.4 ± 0.5, P < 0.001). Mean intraoperative blood loss (9.75 ± 5.4 vs 7.48 ± 3.9, P = 0.035) and transfusion requirements (57.5% vs 25%, P = 0.006) were significantly less in the EHH group, but postoperative blood loss, duration of hospitalization, and other complications were not significantly different in the two study groups. CONCLUSIONS: The use of an electrically heated humidifier did not prevent a body temperature drop under general anesthesia. However, it helped maintain body temperature and was associated less blood loss and transfusion requirement during surgery.

20.
Opt Express ; 19(18): 16730-8, 2011 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-21935035

RESUMEN

We report selective patterning process, laser 'rail-roading' scribing method, of which operating principle is based on transient force balance between the material properties including cohesion and adhesion forces subjected to underlying substrate and laser-induced shock compression and shear forces. By using dual fs-laser beam lines with an interval larger than laser spot size, we provide a proof of the concept by patterning the photovoltaic modules based on CIGS (Cu(In,Ga)Se2) coated on Mo electrode. With varying the interval between the two laser beam tracks, we can provide intact Mo back contact surface without any residues in a manner of more facile, high-speed and high scribing efficiency. We have interpreted the effect of the ambient gases and grooving width on the scribing performance in terms of the cohesion forces between the grains of CIGS thin films as well as adhesion force between underlying Mo layer and CIGS, which are mainly governed by local laser ablation and peening process followed by laser-induced shock compression, respectively.

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