Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Sensors (Basel) ; 20(22)2020 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-33228051

RESUMEN

This study prognoses the remaining useful life of a turbofan engine using a deep learning model, which is essential for the health management of an engine. The proposed deep learning model affords a significantly improved accuracy by organizing networks with a one-dimensional convolutional neural network, long short-term memory, and bidirectional long short-term memory. In particular, this paper investigates two practical and crucial issues in applying the deep learning model for system prognosis. The first is the requirement of numerous sensors for different components, i.e., the curse of dimensionality. Second, the deep neural network cannot identify the problematic component of the turbofan engine due to its "black box" property. This study thus employs dimensionality reduction and Shapley additive explanation (SHAP) techniques. Dimensionality reduction in the model reduces the complexity and prevents overfitting, while maintaining high accuracy. SHAP analyzes and visualizes the black box to identify the sensors. The experimental results demonstrate the high accuracy and efficiency of the proposed model with dimensionality reduction and show that SHAP enhances the explainability in a conventional deep learning model for system prognosis.

2.
Sensors (Basel) ; 20(7)2020 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-32235532

RESUMEN

This paper presents a wearable hand module which was made of five fiber Bragg grating (FBG) strain sensor and algorithms to achieve high accuracy even when worn on different hand sizes of users. For real-time calculation with high accuracy, FBG strain sensors move continuously according to the size of the hand and the bending of the joint. Representatively, four algorithms were proposed; point strain (PTS), area summation (AREA), proportional summation (PS), and PS/interference (PS/I or PS/I_α). For more accurate and efficient assessments, 3D printed hand replica with different finger sizes was adopted and quantitative evaluations were performed for index~little fingers (77 to 117 mm) and thumb (68~78 mm). For index~little fingers, the optimized algorithms were PS and PS/I_α. For thumb, the optimized algorithms were PS/I_α and AREA. The average error angle of the wearable hand module was observed to be 0.47 ± 2.51° and mean absolute error (MAE) was achieved at 1.63 ± 1.97°. These results showed that more accurate hand modules than other glove modules applied to different hand sizes can be manufactured using FBG strain sensors which move continuously and algorithms for tracking this movable FBG sensors.


Asunto(s)
Técnicas Biosensibles , Dedos/anatomía & histología , Mano/anatomía & histología , Dispositivos Electrónicos Vestibles , Algoritmos , Humanos , Impresión Tridimensional
3.
BMC Womens Health ; 19(1): 23, 2019 01 29.
Artículo en Inglés | MEDLINE | ID: mdl-30696454

RESUMEN

BACKGROUND: The risk for obesity-related diseases increases with the prevalence of obesity. In obesity, adipokines secreted from adipose tissue induce inflammation, causing adverse effects. Recently, adipokines such as apelin, visfatin, and chemerin have been studied. Long-term resistance training improves health in middle-aged women by improving metabolic risk factors, body composition, and muscle strength. However, there is still a lack of evidence on the association of apelin concentration with different exercise types in middle-aged obese women This study aimed to investigate the effects of 8 weeks of aerobic and resistance exercises on apelin-12 and apelin-36 levels and thereby verify the effects of different exercise types in obese, middle-aged women. METHODS: Participants were middle-aged women aged 50-61 years, with no experience of systematic exercise in the last 6 months, and met the WHO obesity criteria for the Asia-Pacific region of waist circumference ≥ 80 cm and body fat percentage ≥ 30%. Subjects were selected and allocated to the aerobic exercise, resistance exercise, or no exercise group by block randomization. Body weight, body fat, and body mass index were measured by bioelectrical impedance analysis. Analysis of variance, the t-test, and Tukey's post-hoc test were performed. RESULTS: A total of 24 participants were selected with eight participants in each group. Both aerobic and resistance exercises were effective in altering the physical composition, showing significant decreases in weight, waist circumference, BMI, and body fat. The aerobic and resistance exercise group showed a significant, positive change in apelin-12 levels. CONCLUSIONS: In obese individuals, aerobic and resistance exercise were effective in improving obesity and reducing blood apelin-12 concentration, which is closely correlated with indicators of metabolic syndrome. Future research should focus on comparing the response of apelin to exercise in obese subjects treated with only dietary control and the response in the obese subjects of different ages and sex. TRIAL REGISTRATION: No. 1040917-201,506-BR-153-04 , Clinical Research Information Service (CRIS), Republic of Korea (05 October 2018, retrospectively registered).


Asunto(s)
Apelina/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Obesidad/metabolismo , Obesidad/terapia , Entrenamiento de Fuerza , Composición Corporal , Índice de Masa Corporal , Peso Corporal , Ejercicio Físico/fisiología , Terapia por Ejercicio , Femenino , Humanos , Masculino , Síndrome Metabólico , Persona de Mediana Edad , República de Corea , Estudios Retrospectivos
4.
Small ; 14(41): e1803000, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30350552

RESUMEN

Biophysical properties are intimately connected to metastatic functions and aggressiveness in cancers. Especially, cellular stiffness is regarded as a biomarker for the understanding of metastatic potential and drug sensitivity. Here, protease-mediated changes of cortical stiffness are identified due to the deformation of cytoskeleton alignment at a cortex. For the past few decades, membrane type 1-matrix metalloproteinase (MT1-MMP) has been well known as a kernel protease enriched in podosomes during metastasis for extracellular matrix degradation. However, the biophysical significance of MT1-MMP expressing cancer cells is still unknown. Therefore, the nanomechanics of cancer cells is analyzed by a nanoindentation using a microsphere-attached cantilever of atomic force microscopy (AFM). In conclusion, the results suggest that MT1-MMP has contributed as a key regulator in cytoskeletal deformation related with cancer metastasis. Particularly, the AFM-based nanoindentation system for the monitoring of cortical nanomechanics will be crucial to understand molecular networks in cancers.


Asunto(s)
Metaloproteinasa 14 de la Matriz/química , Microesferas , Citoesqueleto/química , Microscopía de Fuerza Atómica
5.
Small ; 13(43)2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28524361

RESUMEN

Fabrication strategies that pursue "simplicity" for the production process and "functionality" for a device, in general, are mutually exclusive. Therefore, strategies that are less expensive, less equipment-intensive, and consequently, more accessible to researchers for the realization of omnipresent electronics are required. Here, this study presents a conceptually different approach that utilizes the inartificial design of the surface roughness of paper to realize a capacitive pressure sensor with high performance compared with sensors produced using costly microfabrication processes. This study utilizes a writing activity with a pencil and paper, which enables the construction of a fundamental capacitor that can be used as a flexible capacitive pressure sensor with high pressure sensitivity and short response time and that it can be inexpensively fabricated over large areas. Furthermore, the paper-based pressure sensors are integrated into a fully functional 3D touch-pad device, which is a step toward the realization of omnipresent electronics.

6.
Neurol Sci ; 37(1): 89-95, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26292789

RESUMEN

Acute confusional migraine (ACM) shows typical electroencephalography (EEG) patterns of diffuse delta slowing and frontal intermittent rhythmic delta activity (FIRDA). The pathophysiology of ACM is still unclear but these patterns suggest neuronal dysfunction in specific brain areas. We performed source localization analysis of IRDA (in the frequency band of 1-3.5 Hz) to better understand the ACM mechanism. Typical IRDA EEG patterns were recorded in a patient with ACM during the acute stage. A second EEG was obtained after recovery from ACM. To identify source localization of IRDA, statistical non-parametric mapping using standardized low-resolution brain electromagnetic tomography was performed for the delta frequency band comparisons between ACM attack and non-attack periods. A difference in the current density maximum was found in the dorsal anterior cingulated cortex (ACC). The significant differences were widely distributed over the frontal, parietal, temporal and limbic lobe, paracentral lobule and insula and were predominant in the left hemisphere. Dorsal ACC dysfunction was demonstrated for the first time in a patient with ACM in this source localization analysis of IRDA. The ACC plays an important role in the frontal attentional control system and acute confusion. This dysfunction of the dorsal ACC might represent an important ACM pathophysiology.


Asunto(s)
Encéfalo/fisiopatología , Ritmo Delta/fisiología , Trastornos Migrañosos/fisiopatología , Enfermedad Aguda , Mapeo Encefálico/métodos , Niño , Electroencefalografía/métodos , Humanos , Masculino
7.
Exp Cell Res ; 327(2): 264-75, 2014 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-25128810

RESUMEN

Hispidin, a phenolic compound from Phellinus linteus (a medicinal mushroom), has been shown to possess strong anti-oxidant, anti-cancer, anti-diabetic, and anti-dementia properties. However, the cardioprotective efficacy of hispidin has not yet been investigated. In the present study, we investigated the protective effect of hispidin against oxidative stress-induced apoptosis in H9c2 cardiomyoblast cells and neonatal rat ventricular myocytes. While the treatment of H9c2 cardiomyoblast cells with hydrogen peroxide caused a loss of cell viability and an increase in the number of apoptotic cells, hispidin significantly protected the cells against hydrogen peroxide-induced cell death without any cytotoxicity as determined by XTT assay, LDH release assay, Hoechst 33342 assay, and Western blotting of apoptosis proteins such as caspase-3, Bax, and Bcl-2. Our data also shows that hispidin significantly scavenged intracellular ROS, and markedly enhanced the expression of antioxidant enzymes such as heme oxygenase-1 and catalase, which was accompanied by the concomitant activation of Akt/GSK-3ß and ERK1/2 phosphorylation in H9c2 cardiomyoblast cells. The effects of hispidin on Akt and ERK phosphorylation were abrogated by LY294002 (a PI3K/Akt inhibitor) and U0126 (an ERK1/2 inhibitor). The effect of hispidin on GSK-3b activities was also blocked by LY294002. Furthermore, inhibiting the Akt/GSK-3ß and ERK1/2 pathway by these inhibitors significantly reversed the hispidin-induced Bax and Bcl-2 expression, apoptosis induction, and ROS production. These findings indicate that hispidin protects against apoptosis in H9c2 cardiomyoblast cells exposed to hydrogen peroxide through reducing intracellular ROS production, regulating apoptosis-related proteins, and the activation of the Akt/GSK-3ß and ERK1/2 signaling pathways.


Asunto(s)
Apoptosis/efectos de los fármacos , Glucógeno Sintasa Quinasa 3/metabolismo , Peróxido de Hidrógeno/farmacología , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pironas/farmacología , Animales , Western Blotting , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Glucógeno Sintasa Quinasa 3 beta , Miocitos Cardíacos/metabolismo , Oxidantes/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/efectos de los fármacos
8.
Pharmacology ; 96(5-6): 259-70, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26550832

RESUMEN

INH2BP (5-iodo-6-amino-1,2-benzopyrone), a poly-ADP ribose polymerase inhibitor, has been shown to possess anti-cancer, anti-viral, and anti-inflammation properties. The aim of this study was to investigate the protective effect of INH2BP against oxidative stress-induced apoptosis in H9c2 cardiomyoblast cells. While the treatment of H9c2 cardiomyoblasts cells with hydrogen peroxide (H2O2) caused a loss of cell viability and an increase in the number of apoptotic cells, INH2BP significantly protected the cells against H2O2-induced cell death without any cytotoxicity. Our data also shows that INH2BP significantly scavenged intracellular reactive oxygen species (ROS), and markedly enhanced the expression of antioxidant enzymes such as Mn-SOD (superoxide) and Cu/Zn-SOD, and heme oxygenase-1, which was accompanied by the concomitant activation of extracellular regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) phosphorylation in H9c2 cells. The effects of INH2BP on ERK1/2 and p38 MAPK phosphorylation were abrogated by PD98059, an ERK1/2 inhibitor, and SB203580, a p38 inhibitor. In addition, inhibition of ERK1/2 and p38 MAPK by these inhibitors significantly attenuated INH2BP-mediated H9c2 viability as well as cleaved caspases-3, Bax, and Bcl-2 activation. Taken together, these results demonstrate that INH2BP prevents H2O2-induced apoptosis in H9c2 cells by reducing the production of intracellular ROS, regulating apoptotic-related proteins, and the activation of the ERK1/2 and p38 MAPK.


Asunto(s)
Apoptosis/efectos de los fármacos , Cumarinas/farmacología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Sustancias Protectoras/farmacología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Peróxido de Hidrógeno/farmacología , Mioblastos Cardíacos/efectos de los fármacos , Mioblastos Cardíacos/enzimología , Ratas , Especies Reactivas de Oxígeno/metabolismo
9.
Nano Lett ; 14(5): 2536-40, 2014 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-24697539

RESUMEN

The phenomenon of surface self-healing in C60-based polymer coatings deposited by ion-beam assisted physical vapor deposition was investigated. Nanoindentation of the coatings led to the formation of a protrusion rather than an indent. This protrusion was accompanied by an abnormal shape of the force-distance curve, where the unloading curve lies above the loading curve due to an additional force applied in pulling the indenter out of the media. The coatings exhibited a nanocomposite structure that was strongly affected by the ratio of C60 ion and C60 molecular beam intensities during deposition. The coatings also demonstrated the dynamic hardness effect, where the effective value of the hardness depends significantly on the indentation speed.

10.
Biomed Microdevices ; 16(3): 397-413, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24634056

RESUMEN

During the last several years, legged locomotive mechanism has been considered as one of the main self-propelling mechanisms for future endoscopic microrobots due to its superior propulsion efficiency of an endoscopic microrobot inside the intestinal track. Nevertheless, its clinical application has been largely limited since the legged locomotive mechanism utilizes an end effector which has a sharp tip to generate sufficient traction by physically penetrating and interlocking with the intestinal tissue. This can cause excessive physical tissue damage or even complete perforation of the intestinal wall that can lead to abdominal inflammation. Hence, in this work two types of new end effectors, penetration-limited end effector (PLEE) and bi-material structured end effector (BMEE) were specially designed to acquire high medical safety as well as effective traction generation performance. The microscopic end effector specimens were fabricated with micro-wire electric discharge machining process. Traction generation performance of the end effectors was evaluated by direct measurement of resistance forces during contact-sliding tests using a custom-built contact-sliding tester. The safety of the end effector design was evaluated by examination of microscopic intestinal tissue damage using a scanning electron microscope (SEM). Physical damage characteristics of the intestinal tissue and related contact physics of the end effectors were discussed. From the results, the end effectors were evaluated with respect to their prospects in future medical applications as safe end effectors as well as micro-surgical tools.


Asunto(s)
Endoscopía/efectos adversos , Endoscopía/instrumentación , Intestino Grueso/citología , Microtecnología/instrumentación , Robótica/instrumentación , Seguridad , Animales , Diseño de Equipo , Fenómenos Mecánicos , Membrana Mucosa/citología , Porcinos
11.
ACS Appl Mater Interfaces ; 16(14): 18090-18098, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38533722

RESUMEN

Multilayer coatings offer significant advantages in protecting materials' surfaces by shielding the underlying materials hierarchically from damage and wear. The layering morphology and structure of multilayer coatings directly affect their wear resistance capacity. Using a systematic set of experiments and molecular dynamics (MD) simulations, we studied the effect of layering thickness on the macroscale wear response of DLC/WC multinanolayer coatings. Our study revealed the existence of a critical bilayer thickness where maximum scratch hardness and wear resistance can be achieved. Our large-scale MD simulations showed that reducing the WC layer thickness to a certain limit increases the scratch hardness due to the confinement of dislocation motion. However, when the thickness of the WC layers falls below 2 nm, the deformation mechanism transitions from the interface-induced dislocation confinement to the interface-mediated amorphization of WC layers, reducing the scratch hardness of the coating. This finding offers a procedure for optimizing the macroscale wear performance of multinanolayer coatings.

12.
Redox Biol ; 71: 103101, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38408409

RESUMEN

Physical activity has been considered an important non-medication intervention in preserving mnemonic processes during aging. However, how aerobic exercise promotes such benefits for human health remains unclear. In this study, we aimed to explore the neuroprotective and anti-inflammatory effects of aerobic exercise against lipopolysaccharide (LPS)-induced amnesic C57BL/6J mice and BV-2 microglial cell models. In the in vivo experiment, the aerobic exercise training groups were allowed to run on a motorized treadmill 5 days/week for 4 weeks at a speed of 10 rpm/min, with LPS (0.1 mg/kg) intraperitoneally injected once a week for 4 weeks. We found that aerobic exercise ameliorated memory impairment and cognitive deficits among the amnesic mice. Correspondingly, aerobic exercise significantly increased the protein expressions of FNDC5, which activates target neuroprotective markers BDNF and CREB, and antioxidant markers Nrf2/HO-1, leading to inhibiting microglial-mediated neuroinflammation and reduced the expression of BACE-1 in the hippocampus and cerebral cortex of amnesic mice. We estimated that aerobic exercise inhibited neuroinflammation in part through the action of FNDC5/irisin on microglial cells. Therefore, we explored the anti-inflammatory effects of irisin on LPS-stimulated BV-2 microglial cells. In the in vitro experiment, irisin treatment blocked NF-κB/MAPK/IRF3 signaling activation concomitantly with the significantly lowered levels of the LPS-induced iNOS and COX-2 elevations and promotes the Nrf2/HO-1 expression in the LPS-stimulated BV-2 microglial cells. Together, our findings suggest that aerobic exercise can improve the spatial learning ability and cognitive functions of LPS-treated mice by inhibiting microglia-mediated neuroinflammation through its effect on the expression of BDNF/FNDC5/irisin.


Asunto(s)
Disfunción Cognitiva , Lipopolisacáridos , Ratones , Humanos , Animales , Lipopolisacáridos/efectos adversos , Enfermedades Neuroinflamatorias , Fibronectinas/metabolismo , Factor 2 Relacionado con NF-E2/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ratones Endogámicos C57BL , Disfunción Cognitiva/terapia , Disfunción Cognitiva/tratamiento farmacológico , Estrés Oxidativo , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , FN-kappa B/metabolismo , Inflamación/terapia , Inflamación/tratamiento farmacológico
13.
Materials (Basel) ; 16(17)2023 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-37687480

RESUMEN

The tribological properties and preosteoblast behavior of an RF magnetron-sputtered amorphous carbon coating on a Si (100) substrate were evaluated. The graphite target power was varied from 200 to 500 W to obtain various coating structures. The amorphous nature of the coatings was confirmed via Raman analysis. The contact angle also increased from 58º to 103º, which confirmed the transformation of the a-C surface from a hydrophilic to hydrophobic nature with an increasing graphite target power. A minimum wear rate of about 4.73 × 10-8 mm3/N*mm was obtained for an a-C coating deposited at a 300 W target power. The 300 W and 400 W target power coatings possessed good tribological properties, and the 500 W coating possessed better cell viability and adhesion on the substrate. The results suggest that the microstructure, wettability, tribological behavior and biocompatibility of the a-C coating were highly dependent on the target power of the graphite. A Finite Element Analysis (FEA) showed a considerable increase in the Von Mises stress as the mesh size decreased. Considering both the cell viability and tribological properties, the 400 W target power coating was identified to have the best tribological property as well as biocompatibility.

14.
Biofouling ; 28(8): 779-87, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22827159

RESUMEN

A relatively simple method was developed to fabricate CrN/Cu nanocomposite coatings using pulsed DC magnetron sputtering for application in antibacterial activity. These nanocomposite coatings were applied on titanium (Ti)-modified stainless steel substrata (D-9 alloy) and the antibacterial activity of these coating with respect to the Gram-negative bacterium Pseudomonas aeruginosa was investigated qualitatively and quantitatively. Scanning electron microscopy, epifluorescence microscope analyses, and total viable counts confirmed that inclusion of copper in the CrN/Cu nanocomposite coatings provided antibacterial activity against P. aeruginosa. The quantitative examination of the bacterial activity of P. aeruginosa was estimated by the survival ratio as calculated from the number of viable cells which formed colonies on nutrient agar plates.


Asunto(s)
Incrustaciones Biológicas/prevención & control , Cobre/administración & dosificación , Nanocompuestos , Pseudomonas aeruginosa/efectos de los fármacos , Adhesión Bacteriana , Biopelículas , Células Cultivadas , Compuestos de Cromo/administración & dosificación , Nanocompuestos/química , Compuestos de Nitrógeno/administración & dosificación , Espectroscopía de Fotoelectrones , Acero Inoxidable , Difracción de Rayos X
15.
J Public Health (Oxf) ; 34(4): 562-9, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22580384

RESUMEN

BACKGROUND: The aim of this study was to investigate the association between obesity and prehypertension (preHT) after adjustment for socioeconomic position and health behavior factors. METHODS: The study sample included 1973 Korean men and women, 45-64 years of age. Subjects were classified into three groups based on their baseline blood pressure: prehypertensive, hypertensive and normotensive. Men with a waist circumference ≥90 cm or women ≥80 cm were considered abdominally obese. Body mass index (BMI) obesity was defined as having a BMI ≥25. The prevalence of abdominal obesity and BMI obesity was calculated with age adjustment using a direct method. Multinomial logistic regression analysis was applied. RESULTS: The prevalence of preHT in our study was 52.8%. We found that subjects with abdominal obesity were 2.06 times as likely to be prehypertensive as those without it and people with BMI obesity were 1.89 times as likely to be prehypertensive as those without it. Interestingly, men with BMI obesity had a higher preHT risk, while women with abdominal obesity had a higher preHT risk. CONCLUSIONS: Statistical analyses of a community-based random sample of the Korean population indicate that obesity is associated with preHT in Korean middle-aged subjects.


Asunto(s)
Obesidad/epidemiología , Prehipertensión/epidemiología , Índice de Masa Corporal , Comorbilidad , Femenino , Conductas Relacionadas con la Salud , Encuestas Epidemiológicas , Humanos , Masculino , Persona de Mediana Edad , Obesidad Abdominal/epidemiología , Prevalencia , República de Corea/epidemiología , Distribución por Sexo , Factores Socioeconómicos , Circunferencia de la Cintura
16.
J Clin Nurs ; 21(15-16): 2188-92, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22672009

RESUMEN

AIMS AND OBJECTIVES: The aim of this study was to compare the return of bowel function and xerostomia in patients who were and were not instructed to chew gum after elective open liver resection. BACKGROUND: Patients who undergo liver resection have limited early ambulation, because they require bed rest after surgery to prevent internal bleeding. They normally also require narcotic analgesics or patient-controlled analgesia for pain control. For these reasons, they often have symptoms of intestinal gas accumulation, abdominal distension and/or abdominal pain. DESIGN: Prospective case-control study. METHODS: Forty-two patients with hepatocellular carcinoma who were treated at Samsung Medical Center from September 2010 to February 2011 were included in this study. Patients who were scheduled for elective liver resection for hepatocellular carcinoma and were over 30 years of age were eligible. Patients were assigned to a gum-chewing group or a non-gum-chewing (control) group before surgery. RESULTS: The mean age of the gum-chewing group was 54·9 (±9·7) years, and the mean age of the control group was 55·1 (±8·4) years. The mean values of first flatus time and xerostomia were higher in the control group than in the gum-chewing group. First flatus time and xerostomia grade were significantly decreased in gum-chewing group compared with the control group after adjustment for hospitalisation days, duration of surgery and amount of analgesics administered. CONCLUSION: Patients who were instructed to chew gum after surgery demonstrated faster bowel function recovery and lower xerostomia grade after elective open liver resection than patients who did not chew gum. RELEVANCE TO CLINICAL PRACTICE: Gum-chewing is an inexpensive, helpful adjunct to standard postoperative care after liver resection.


Asunto(s)
Carcinoma Hepatocelular/cirugía , Goma de Mascar , Flatulencia , Motilidad Gastrointestinal , Neoplasias Hepáticas/cirugía , Xerostomía , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , República de Corea , Resultado del Tratamiento
17.
Biomater Sci ; 10(9): 2224-2236, 2022 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-35344987

RESUMEN

Poly(methyl methacrylate) (PMMA)-based denture base resins easily develop oral bacterial and fungal biofilms, which may constitute a significant health risk. Conventional bacterial-resistant additives and coatings often cause undesirable changes in the resin. Reduced bacterial resistance over time in the harsh oral environment is a major challenge in resin development. Poly(2-methoxyethyl acrylate) (PMEA) has anti-fouling properties; however, due to the oily/rubbery state of this polymer, and its surface aggregation tendency in a resin mixture, its direct use as a resin additive is limited. This study aimed to optimize the use of PMEA in dental resins. Acrylic resins containing a series of PMEA polymers with various molecular weights (MWs) at different concentrations were prepared, and the mechanical properties, surface gloss, direct transmittance, and cytotoxicity were evaluated, along with the distribution of PMEA in the resin. Resins with low-MW PMEA (2000 g mol-1) (PMEA-1) at low concentrations satisfied the clinical requirements for denture resins, and the PMEA was homogeneously distributed. The anti-fouling performance of the resin was evaluated for protein adsorption, bacterial and fungal attachment, and saliva-derived biofilm formation. The PMEA-1 resin most effectively inhibited biofilm formation (∼50% reduction in biofilm mass and thickness compared to those of the control). Post-aged resins maintained their mechanical properties and anti-fouling activity, and polished surfaces had the same anti-biofilm behavior. Based on wettability and tribological results, we propose that the PMEA additive creates a non-stick surface to inhibit biofilm formation. This study demonstrated that PMEA additives can provide a stable and biocompatible anti-fouling surface, without sacrificing the mechanical properties and aesthetics of denture resins.


Asunto(s)
Incrustaciones Biológicas , Bases para Dentadura , Acrilatos , Incrustaciones Biológicas/prevención & control , Bases para Dentadura/microbiología , Ensayo de Materiales , Peso Molecular , Polímeros , Polimetil Metacrilato , Propiedades de Superficie
18.
BMC Cancer ; 11: 489, 2011 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-22103888

RESUMEN

BACKGROUND: There is increasing evidence that the presence of an ongoing systemic inflammatory response is associated with poor prognosis in patients with advanced cancers. We evaluated the relationships between clinical status, laboratory factors and progression free survival (PFS), and overall survival (OS) in patients with recurrent or metastatic gastric cancer receiving first-line palliative chemotherapy. METHODS: We reviewed 402 patients with advanced gastric adenocarcinoma who received first-line palliative chemotherapy from June 2004 and December 2009. Various chemotherapy regimens were used. Eastern Cooperative Oncology Group performance status (ECOG PS), C-reactive protein (CRP), albumin, Glasgow prognostic score (GPS), and clinical factors were recorded immediately prior to first-line chemotherapy. Patients with both an elevated CRP (>1.0 mg/dL) and hypoalbuminemia (<3.5 mg/dL) were assigned a GPS of 2. Patients in whom only one of these biochemical abnormalities was present were assigned a GPS of 1, and patients with a normal CRP and albumin were assigned a score of 0. To evaluate the factors that affected PFS and OS, univariate and multivariate analyses were performed. RESULTS: According to multivariate analysis, the factors independently associated with PFS were ECOG PS (HR 1.37, 95% CI 1.02-1.84, P = 0.035), bone metastasis (HR 1.74, 95% CI 1.14-2.65, P = 0.009), and CRP elevation (HR 1.64, 95% CI 1.28-2.09, P = 0.001). The factors independently associated with OS were ECOG PS (HR 1.33, 95% CI 1.01-1.76, P = 0.037), bone metastasis (HR 1.61, 95% CI 1.08-2.39, P = 0.017), and GPS ≥ 1 (HR 1.76, 95% CI 1.41-2.19, P = 0.001). CONCLUSIONS: The results of this study showed that the presence of a systemic inflammatory response as evidenced by the CRP, GPS was significantly associated with shorter PFS and OS in patients with recurrent or metastatic gastric cancer receiving first-line palliative chemotherapy. Bone metastasis and GPS were very useful indicator for survival in patients with recurrent or metastatic gastric cancer receiving palliative chemotherapy.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neoplasias Gástricas/tratamiento farmacológico , Adenocarcinoma/metabolismo , Adenocarcinoma/mortalidad , Adulto , Anciano , Anciano de 80 o más Años , Albúminas/metabolismo , Neoplasias Óseas/secundario , Proteína C-Reactiva/metabolismo , Supervivencia sin Enfermedad , Femenino , Indicadores de Salud , Humanos , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Análisis Multivariante , Metástasis de la Neoplasia , Cuidados Paliativos , Pronóstico , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/mortalidad , Análisis de Supervivencia , Síndrome de Respuesta Inflamatoria Sistémica/metabolismo , Adulto Joven
19.
J Korean Med Sci ; 26(11): 1439-45, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22065899

RESUMEN

KITENIN (KAI1 C-terminal interacting tetraspanin) promotes invasion and metastasis in mouse colon cancer models. In the present study, we evaluated the effects of KITENIN knockdown by intravenous administration of short hairpin RNAs (shRNAs) in an orthotopic mouse colon cancer model, simulating a primary or adjuvant treatment setting. We established orthotopic models for colon cancer using BALB/c mice and firefly luciferase-expressing CT-26 (CT26/Fluc) cells. Tumor progression and response to therapy were monitored by bioluminescence imaging (BLI). In the primary therapy model, treatment with KITENIN shRNA substantially delayed tumor growth (P = 0.028) and reduced the incidence of hepatic metastasis (P = 0.046). In the adjuvant therapy model, KITENIN shRNA significantly reduced the extent of tumor recurrence (P = 0.044). Mice treated with KITENIN shRNA showed a better survival tendency than the control mice (P = 0.074). Our results suggest that shRNA targeting KITENIN has the potential to be an effective tool for the treatment of colon cancer in both adjuvant and metastatic setting.


Asunto(s)
Proteínas Portadoras/genética , Neoplasias del Colon/terapia , Neoplasias Hepáticas/secundario , Proteínas de la Membrana/genética , Metástasis de la Neoplasia/prevención & control , Recurrencia Local de Neoplasia/prevención & control , ARN Interferente Pequeño/uso terapéutico , Animales , Biomarcadores de Tumor/genética , Proteínas Portadoras/metabolismo , Línea Celular Tumoral , Neoplasias del Colon/genética , Neoplasias del Colon/mortalidad , Neoplasias del Colon/patología , Progresión de la Enfermedad , Neoplasias Hepáticas/prevención & control , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos BALB C , Recurrencia Local de Neoplasia/genética , Interferencia de ARN
20.
Nanomaterials (Basel) ; 11(2)2021 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-33546353

RESUMEN

We investigated the tribological behavior of commercialized, fully synthetic engine oil upon the incorporation of reduced graphene oxide in seven different concentrations between 0.01 and 0.2 wt %. Stability of the prepared samples was assessed by turbidimetry and dynamic light scattering measurements, and their tribological properties through a reciprocating tribometer, using a steel ball on special cut steel blocks. The addition of 0.02 wt % of reduced graphene oxide led to an improvement of the tribological behavior compared to the pristine engine oil, by significantly lowering the friction coefficient by 5% in the boundary lubrication regime. Both the surfaces and the reduced graphene oxide additive were thoroughly characterized by microscopic and optical spectroscopy techniques. We also verified that a protective layer was formed between the worn surfaces, due to the presence of reduced graphene oxide. Carbon accumulation and various additive elements such as Ca, Zn, S and P were detected on the rubbing surfaces of both the ball and the block through energy-dispersive X-ray spectroscopy. Finally, it was shown that the wear scar diameter on the surface of the steel ball was lower by 3%, upon testing the engine oil sample containing reduced graphene oxide at concentration 0.02 wt %, compared to the control sample.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA