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1.
Psychol Med ; 53(2): 362-370, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-33926584

RESUMEN

BACKGROUND: High rates of physical and mental health comorbidities are associated with functional impairment among persons who are homeless. Cognitive dysfunction is common, but how it contributes to various functional outcomes in this population has not been well investigated. This study examines how cognition covaries with community functioning and subjective quality of life over a 6-year period while accounting for the effects of risk and protective factors. METHODS: Participants were 349 homeless adults (mean age = 39.8) recruited from the Toronto site of the At Home/Chez Soi study, a large Canadian randomized control trial of Housing First. Participants completed up to four clinical evaluations over 6 years. Factor scores were created to index verbal learning and memory (vLM) and processing speed-cognitive flexibility (PSCF). The primary outcomes were community functioning and subjective quality of life. Risk factors included lifetime homelessness, mental health diagnoses, medical comorbidity, and childhood adversity. Linear mixed-effects models were conducted to examine cognition-functional outcome associations over time, with resilience as a moderator. RESULTS: Better vLM (b = 0.787, p = 0.010) and PSCF (b = 1.66, p < 0.001) were associated with better community functioning, but not with quality of life. Resilience conferred a protective effect on subjective quality of life (b = 1.45, p = 0.011) but did not moderate outcomes. CONCLUSIONS: Our findings suggest a need to consider the unique determinants of community functioning and quality of life among homeless adults. Cognition should be prioritized as a key intervention target within existing service delivery models to optimize long-term functional outcomes.


Asunto(s)
Personas con Mala Vivienda , Trastornos Mentales , Adulto , Humanos , Calidad de Vida , Estudios de Seguimiento , Canadá/epidemiología , Trastornos Mentales/psicología , Cognición
3.
Pulmonology ; 27(4): 286-295, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-32474057

RESUMEN

OBJECTIVE: Smoking is an important causative factor of chronic obstructive pulmonary disease (COPD), and females are considered more susceptible to the effects of smoking than males. However, in previous Korean studies, the effects of sex differences on the association between smoking and COPD have been controversial. In this study, the effects of sex differences on the association between smoking and COPD and the effects of female hidden smokers on that association in Korean adults were investigated. METHODS: Data were acquired from the Korea National Health and Nutrition Examination Surveys (KNHANES). RESULTS: The multivariate logistic regression analysis showed that self-reported smoking status for ex-smoker and current smoker correlated with COPD (odds ratio, OR: 1.67 and OR: 2.41, respectively). Self-reported smoking status for ex-smoker and current smoker correlated with COPD in men (OR: 1.61, OR: 2.43, respectively). Female self-reported current smoking status correlated with COPD (OR: 2.52), but female ex-smoker status was not significantly correlated with COPD. The ratios of cotinine-verified to self-reported smoking rates were 1.95 for women and 1.07 for men. CONCLUSION: The results of this study were that sex differences might affect the association between COPD and smoking and that female hidden smoking might affect the association between smoking and COPD in Korean adults.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Fumadores/estadística & datos numéricos , Fumar/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Cotinina , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vigilancia de la Población , Enfermedad Pulmonar Obstructiva Crónica/etiología , República de Corea/epidemiología
4.
Colorectal Dis ; 22(12): 2008-2017, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32866340

RESUMEN

AIM: The main aim of this study was to compare the long-term outcome of a conventional colorectal endoscopic submucosal dissection (ESD) in which submucosal dissection was continued throughout until the completion of resection (ESD-T) to hybrid endoscopic submucosal dissection (ESD-H) in the colorectum. METHOD: Medical records of 836 colorectal neoplasia patients treated by ESD-T or ESD-H were reviewed. ESD-H was defined as colorectal ESD with additional snaring in the final stage of the procedure. Primary outcomes were the overall and metastatic recurrence rates. Secondary outcomes were short-term outcomes such as the en bloc resection rate, procedure time and adverse events. RESULTS: The overall recurrence rate was higher in the ESD-H than in the ESD-T group (5.7% vs 0.7%, P = 0.001). The metastatic recurrence rate showed no significant difference between these groups (1.4% vs 1.4%, P = 1.000). Multivariate analysis revealed that a failed en bloc resection (hazard ratio 24.097; 95% CI 5.446-106.237; P < 0.001) and larger tumour size (hazard ratio 1.042; 95% CI 1.014-1.070; P = 0.003) were independently associated with overall recurrence. The ESD-H group showed a lower en bloc resection rate (56.8% vs 96.5%, P < 0.001), shorter procedure time (45.6 vs 54.3 min, P < 0.001) and higher perforation rate (10.3% vs 6.0%, P = 0.029). CONCLUSION: Although long-term outcomes in terms of overall recurrence are inferior following ESD-H, a failed en bloc resection and large tumour size are the only independent risk factors for recurrence. Further investigations are warranted to improve the long-term outcomes of ESD-H.


Asunto(s)
Neoplasias Colorrectales , Resección Endoscópica de la Mucosa , Neoplasias Colorrectales/cirugía , Disección , Resección Endoscópica de la Mucosa/efectos adversos , Humanos , Recurrencia Local de Neoplasia/epidemiología , Estudios Retrospectivos , Resultado del Tratamiento
5.
Neurogastroenterol Motil ; 30(9): e13376, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29797379

RESUMEN

BACKGROUND: Conventional anorectal manometric parameters based on linear waves cannot properly predict balloon expulsion (BE) time. We aimed to determine the correlation between integrated pressurized volume (IPV) parameters during simulated evacuation (SE) and BE time in healthy individuals and constipated patients and to assess the correlation between each parameter and symptoms. METHODS: A total of 230 male participants (including 26 healthy volunteers and 204 chronically constipated patients) underwent high-resolution anorectal manometry (HRAM) and BE tests. The IPV was calculated by multiplying the amplitude, distance, and time from the HRAM profile. Receiver operating characteristic curve (ROC) analysis and partial least square regression (PLSR) were performed. KEY RESULTS: ROC analysis indicated that the IPV ratio between the upper 1 cm and lower 4 cm of the anal canal was more effective for predicting BE time (area under the curve [AUC]: 0.74, 95% confidence interval [CI]: 0.67-0.80, P < .01) than the conventional anorectal parameters, including defecation index and rectoanal gradient (AUC: 0.60, 95% CI: 0.52-0.67, P = .01). PLSR analysis of a linear combination of IPV parameters yielded an AUC of 0.79. Moreover, the IPV ratio showed a greater clinical correlation with patient symptoms than conventional parameters. CONCLUSIONS AND INFERENCES: The IPV parameters and the combination of IPV parameters via PLSR were more significantly correlated with BE time than the conventional parameters. Thus, this study presents a useful diagnostic tool for the evaluation of pathophysiologic abnormalities in dyssynergic defecation using IPV and BE time.


Asunto(s)
Estreñimiento/diagnóstico , Manometría/métodos , Adulto , Anciano , Canal Anal/fisiopatología , Estreñimiento/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Presión , Recto/fisiopatología
6.
Curr Oncol ; 24(3): 149-150, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28680272
7.
J Nanosci Nanotechnol ; 16(3): 2944-9, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27455739

RESUMEN

Herein, the synthesis of mimosa pudica leaves shaped a-iron oxide (α-Fe2O3) nanostructures is reported through simple and facile hydrothermal process. The prepared α-Fe2O3 nanostructures were characterized in terms of their morphological, structural, compositional and optical properties through a variety of characterization techniques such as FESEM, EDS, XRD, FTIR and Raman spectroscopy. The detailed characterizations revealed the well-crystallinity and dense growth of mimosa pudica leaf shaped α-Fe2O3 nanostructures. Further, the prepared nanomaterials were used as efficient electron mediator to fabricate sensitive ethanol chemical sensor. The fabricated sensor exhibited a high sensitivity of -30.37 µAmM(-1) cm(-2) and low detection limit of -0.62 µM. The observed linear dynamic range (LDR) was in the range from 10 µM-0.625 µM.


Asunto(s)
Etanol/química , Compuestos Férricos/química , Mimosa/química , Nanoestructuras , Hojas de la Planta/química , Microscopía Electrónica de Rastreo , Espectrometría por Rayos X
8.
J Nanosci Nanotechnol ; 15(5): 3956-61, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-26505031

RESUMEN

Well-crystalline sulfur (S) doped ZnO nanowires have been grown via a simple thermal evaporation process on Si substrate using high purity zinc and sulfur powders in presence of oxygen. The as-grown S:ZnO nanowires were characterized in terms of their morphological structural, compositional and optical properties using several techniques such as FESEM, TEM, XRD, EDS and PL. The morphological characterizations revealed that the as-grown nanowires had diameters in the range of 60-100 nm with lengths 5-15 µm. The details structural properties confirmed the well-crystallinity and wurtzite hexagonal phase for the prepared nanowires. Room temperature photoluminescence (PL) spectrum showed a strong green band with a suppressed UV emission. The electrical properties of single S:ZnO nanowire was examined by fabricating single nanowire based field effect transistors (FETs). The detailed electrical transport results showed that S:ZnO nanowires possess n-type semiconducting behavior and exhibited an electron mobility of -67.7 cm2 V(-1) s(-1) and a carrier concentration of 2 x 10(17) cm(-3), respectively.

9.
Br J Pharmacol ; 166(4): 1433-43, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22300296

RESUMEN

BACKGROUND AND PURPOSE: Sensory neuronal and epidermal transient receptor potential ion channels (TRPs) serve an important role as pain sensor molecules. While many natural and synthetic ligands for sensory TRPs have been identified, little is known about the endogenous activator for TRPV4. Recently, we reported that endogenous metabolites produced by the mevalonate pathway regulate the activities of sensory neuronal TRPs. Here, we show that dimethylallyl pyrophosphate (DMAPP), a substance produced by the same pathway is an activator of TRPV4. EXPERIMENTAL APPROACH: We examined the effects of DMAPP on sensory TRPs using Ca²âº imaging and whole-cell electrophysiology experiments with a heterologous expression system (HEK293T cells transfected with individual TRP channels), cultured sensory neurons and keratinocytes. We then evaluated nociceptive behavioural and inflammatory changes upon DMAPP administration in mice in vivo. KEY RESULTS: In the HEK cell heterologous expression system, cultured sensory neurons and keratinocytes, µM concentrations of DMAPP activated TRPV4. Agonistic and antagonistic potencies of DMAPP for other sensory TRP channels were examined and activation of TRPV3 by camphor was found to be inhibited by DMAPP. In vivo assays, intraplantar injection of DMAPP acutely elicited nociceptive flinches that were prevented by pretreatment with TRPV4 blockers, indicating that DMAPP is a novel pain-producing molecule through TRPV4 activation. Further, DMAPP induced acute inflammation and noxious mechanical hypersensitivities in a TRPV4-dependent manner. CONCLUSIONS AND IMPLICATIONS: Overall, we found a novel sensory TRP acting metabolite and suggest that its use may help to elucidate the physiological role of TRPV4 in nociception and associated inflammation.


Asunto(s)
Ganglios Espinales/metabolismo , Hemiterpenos/metabolismo , Proteínas del Tejido Nervioso/agonistas , Neuritis/metabolismo , Neuronas/metabolismo , Dolor Nociceptivo/metabolismo , Compuestos Organofosforados/metabolismo , Canales Catiónicos TRPV/agonistas , Animales , Conducta Animal/efectos de los fármacos , Señalización del Calcio/efectos de los fármacos , Línea Celular , Células Cultivadas , Ganglios Espinales/citología , Ganglios Espinales/efectos de los fármacos , Ganglios Espinales/inmunología , Humanos , Queratinocitos/efectos de los fármacos , Queratinocitos/inmunología , Queratinocitos/metabolismo , Ligandos , Masculino , Ratones , Proteínas del Tejido Nervioso/antagonistas & inhibidores , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Neuronas/inmunología , Dimensión del Dolor/efectos de los fármacos , Isoformas de Proteínas/agonistas , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Ratas , Proteínas Recombinantes/agonistas , Proteínas Recombinantes/antagonistas & inhibidores , Proteínas Recombinantes/metabolismo , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/metabolismo , Canales de Potencial de Receptor Transitorio/agonistas , Canales de Potencial de Receptor Transitorio/antagonistas & inhibidores , Canales de Potencial de Receptor Transitorio/genética , Canales de Potencial de Receptor Transitorio/metabolismo
10.
Talanta ; 89: 155-61, 2012 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-22284474

RESUMEN

This paper reports a very simple, reliable and facile methodology to fabricate ultra-high sensitive liquid ammonia chemical sensor using well-crystalline hexagonal-shaped ZnO nanopencils as an efficient electron mediator. A low-temperature facile hydrothermal technique was used to synthesize ZnO nanopencils. The synthesized nanopencils were characterized in detail in terms of their morphological, structural and optical properties which confirmed that the synthesized nanomaterial is well-crystalline, possessing wurtzite hexagonal phase and possess very good optical properties. A very high sensitivity of ≈ 26.58µAcm(-2)mM(-1) and detection limit of ≈ 5nM with a correlation coefficient (R) of 0.9965 and a response time of less than 10s were observed for the fabricated liquid ammonia by I-V technique. To the best of our knowledge, by comparing the literature, it is confirmed that the fabricated sensor based on ZnO nanopencils exhibits highest sensitivity and lowest detection limit for liquid ammonia. This research opens a way that simply synthesized nanomaterials could be used as efficient electron mediators for the fabrication of efficient liquid ammonia chemical sensors.


Asunto(s)
Amoníaco/análisis , Nanoestructuras/química , Contaminantes Químicos del Agua/análisis , Óxido de Zinc/química , Cristalización , Electrodos , Electrones , Límite de Detección , Microscopía Electrónica de Transmisión , Nanoestructuras/ultraestructura , Espectrometría Raman , Agua/química , Difracción de Rayos X
11.
Br J Pharmacol ; 165(3): 683-92, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21718307

RESUMEN

BACKGROUND AND PURPOSE: Transient receptor potential ion channel vanilloid 3 (TRPV3) is expressed in skin keratinocytes and plays an important role in thermal and chemical nociceptions in the periphery. The presence of TRPV3 inhibitors would improve our understanding of TRPV3 function and help to develop receptor-specific analgesics. However, little is known about physiological substances that specifically inhibit TRPV3 activity. Here, we investigated whether 17(R)-resolvin D1 (17R-RvD1), a naturally occurring pro-resolving lipid specifically affects TRPV3 activity. EXPERIMENTAL APPROACH: We examined the effect of 17R-RvD1 on sensory TRP channels using Ca(2+) imaging and whole cell electrophysiology experiments in a HEK cell heterologous expression system, cultured sensory neurons and keratinocytes. We also examined changes in sensory TRP agonist-specific acute licking/flicking or flinching behaviours and mechanical and thermal pain behaviours using Hargreaves, Randall-Selitto and von Frey assay systems in the absence and presence of inflammation. KEY RESULTS: We showed that 17R-RvD1 specifically suppresses TRPV3-mediated activity at nanomolar and micromolar concentrations. The voltage-dependence of TRPV3 activation by camphor was shifted rightwards by 17R-RvD1, which indicates its inhibitory mechanism is as a result of a shift in voltage-dependence. Consistently, TRPV3-specific acute pain behaviours were attenuated by locally injected 17R-RvD1. Moreover, the administration of 17R-RvD1 significantly reversed the thermal hypersensitivity that occurs during an inflammatory response. Knockdown of epidermal TRPV3 blunted these antinociceptive effects of 17R-RvD1. CONCLUSIONS AND IMPLICATIONS: 17R-RvD1 is a novel natural inhibitory substance specific for TRPV3. The results of our behavioural studies suggest that 17R-RvD1 has acute analgesic potential via TRPV3-specific mechanisms.


Asunto(s)
Analgésicos/uso terapéutico , Antiinflamatorios/uso terapéutico , Ácidos Docosahexaenoicos/uso terapéutico , Dolor/tratamiento farmacológico , Canales Catiónicos TRPV/antagonistas & inhibidores , Analgésicos/farmacología , Animales , Antiinflamatorios/farmacología , Capsaicina , Carragenina , Línea Celular , Ácidos Docosahexaenoicos/farmacología , Adyuvante de Freund , Ganglios Espinales/citología , Células HEK293 , Calor , Humanos , Inflamación/inducido químicamente , Inflamación/tratamiento farmacológico , Inflamación/fisiopatología , Queratinocitos/efectos de los fármacos , Queratinocitos/fisiología , Masculino , Ratones , Ratones Endogámicos ICR , Ratones Noqueados , Dolor/inducido químicamente , Dolor/fisiopatología , Ratas , Ratas Sprague-Dawley , Células Receptoras Sensoriales/efectos de los fármacos , Células Receptoras Sensoriales/fisiología , Canales Catiónicos TRPV/deficiencia , Canales Catiónicos TRPV/genética , Canales Catiónicos TRPV/fisiología
12.
Nutr Metab Cardiovasc Dis ; 22(11): 974-80, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21592755

RESUMEN

BACKGROUND AND AIMS: The association between inflammation and left ventricular (LV) diastolic dysfunction in continuous ambulatory peritoneal dialysis (CAPD) and non-CAPD patients is not established. The objective of this study was to test the above association and whether inflammation interacts with CAPD to increase LV diastolic dysfunction risks. METHODS AND RESULTS: 120 subjects with normal creatinine levels and 101 CAPD patients were recruited. Echocardiographic parameters were assessed in all patients. The participants were classified as having LV diastolic dysfunction by echocardiographic findings including mitral inflow E/A ratio < 1, deceleration time > 220 cm/s, or decreased peak annular early diastolic velocity in tissue Doppler imaging. Blood was sampled at the baseline for measurement of inflammation markers, including tissue necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). Subjects with LV diastolic dysfunction had higher proinflammation cytokines levels in both groups. Inflamed markers correlated significantly with echocardiography parameters for LV diastolic dysfunction in patients receiving CAPD. In a multivariate regression analysis adjusting for all the factors associated with LV diastolic dysfunction, inflammation is still significantly associated with left ventricular diastolic dysfunction (TNF-alpha, OR: 2.6, 95% CI: 2.0-3.35, p < 0.001; IL-6, OR: 1.26, 95% CI: 1.25-1.26, p = 0.01). In addition, the interaction of CAPD and inflammation significantly contributed to the development of LV diastolic dysfunction (CAPD∗ TNF-α: OR: 1.45, 95% CI: 1.13-1.79, P = 0.004). CONCLUSION: We found inflammation plays a vital role for LV diastolic dysfunction especially in CAPD patients. A synergistic effect between CAPD and inflammation, especially TNF-α, would further aggravate LV diastolic dysfunction.


Asunto(s)
Inflamación/fisiopatología , Interleucina-6/sangre , Diálisis Peritoneal Ambulatoria Continua , Factor de Necrosis Tumoral alfa/sangre , Disfunción Ventricular Izquierda/fisiopatología , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Estudios de Casos y Controles , Creatinina/sangre , Ecocardiografía Doppler/métodos , Femenino , Humanos , Inflamación/complicaciones , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Factores de Riesgo , Disfunción Ventricular Izquierda/complicaciones
13.
J Nanosci Nanotechnol ; 11(8): 7222-5, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22103162

RESUMEN

We fabricated an radio frequency (RF) carbon nanotube field effect transistor (CNTFET) whose electrode shapes were standard RF designed ground-signal-ground (GSG)-type pads. The S-parameters measured from our RF CNTFET in the frequency range up to 6 GHz were fitted with an RF equivalent circuit, and the extracted gate capacitance was shown to be the capacitance value of the series combination of the electrostatic capacitance and the quantum capacitance. The effect of the channel resistance and the kinetic inductance was also discussed.

14.
J Colloid Interface Sci ; 363(2): 521-8, 2011 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-21862032

RESUMEN

This paper reports a large-scale synthesis of ZnO balls made of fluffy thin ZnO nanosheets by simple solution process at low-temperature of 65±2°C. The synthesized ZnO structures were characterized in detail in terms of their morphological, structural, optical and photocatalytic properties. The detailed morphological characterizations, done by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), confirmed that the synthesized products are ZnO balls which are made by accumulation of hundreds of thin ZnO nanosheets. Interestingly, it is seen that the nanosheets are arranged in such a special fashion that they made ball-like morphologies. Detailed structural examinations revealed that of as-synthesized ZnO products are well-crystalline and possessing wurtzite hexagonal phase. The optical property, measured by UV-Visible spectroscopy, substantiated good optical properties for as-synthesized ZnO balls. The as-synthesized ZnO balls were utilized as an efficient photocatalysts for the photocatalytic degradation of methylene blue (MB) dye. Almost complete degradation of MB was observed in presence of ZnO balls composed of nanosheets within 70 min under UV-light irradiation. By comparing the photocatalytic performance with commercially available TiO(2)-UV-100, it was observed that the synthesized ZnO balls exhibited superior photocatalytic performance as compared to TiO(2)-UV-100 photocatalyst.

15.
J Nanosci Nanotechnol ; 11(4): 3474-80, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21776726

RESUMEN

In this paper, the high-yield facile synthesis, detailed characterization and photocatalytic application of alpha-Fe2O3 nanoparticles are reported. The synthesis was done via simple hydrothermal process by using aqueous mixtures of iron chloride, hexamethylenediamine and NH3 x H2O at 110 degrees C. The morphologies of the synthesized products were examined by using field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) which confirmed that the synthesized structures are almost spherical shaped nanoparticles with the average diameters of -35 +/- 5 nm, and are grown in high yield. The detailed structural characterizations and composition of the as-synthesized nanoparticles were investigated by using X-ray diffraction (XRD), high-resolution TEM (HRTEM), energy dispersive spectroscopy (EDS) attached with FESEM and Fourier transform infrared spectroscopy (FTIR) which substantiated that the as-synthesized nanoparticles are well crystalline and pure alpha-Fe2O3. The UV-Vis absorption spectrum of the synthesized nanoparticles demonstrated the existence of two optical band gaps which correspond to direct and indirect transitions, respectively. The as-synthesized alpha-Fe2O3 nanoparticles exhibit good photocatalytic properties on photocatalytic degradation of methylene blue.


Asunto(s)
Cristalización/métodos , Compuestos Férricos/química , Nanoestructuras/química , Nanoestructuras/ultraestructura , Sustancias Macromoleculares/química , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Refractometría , Propiedades de Superficie
16.
J Nanosci Nanotechnol ; 11(6): 5102-7, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21770150

RESUMEN

Well-crystalline ZnO nanowires were grown on Si(100) via non-catalytic thermal evaporation process using metallic zinc powder in presence of oxygen. The detailed morphological characterizations by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) confirmed that the synthesized products are nanowires with the typical diameter and lengths of approximately 55 +/- 5 nm and several micrometers, respectively and are grown in high density over the silicon substrate. The detailed structural characterizations by high-resolution TEM and X-ray diffraction confirmed that the synthesized nanowires are well-crystalline and possessing wurtzite hexagonal phase. The presence of Raman-active optical-phonon E2(high) mode at 437 cm(-1) in the Raman-scattering spectrum confirms good crystal quality for the as-grown ZnO nanowires. The electrical transport properties of the as-grown nanowires were explored by fabricating single nanowire based field effect transistors (FETs). The fabricated single ZnO nanowire based FET exhibits carrier concentration and electron mobility of approximately 7.49 x 10(17) cm(-3) and approximately 8.42 cm2V(-1)s(-1), respectively.

17.
J Nanosci Nanotechnol ; 11(5): 4061-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21780406

RESUMEN

A facile aqueous solution process was used to synthesize well-crystalline ZnO nanocones at 60 degrees C by using zinc nitrate hexahydrate and sodium hydroxide. The morphological, structural and optical properties of the synthesized ZnO nanocones were investigated by using field emission scanning electron microscopy (FESEM) attached with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) equipped with high-resolution (HRTEM), X-ray diffraction (XRD) pattern, Fourier transform infrared (FTIR) spectroscopy and UV-Vis. spectroscopy measurements. The structural and optical properties of the as-synthesized nanocones confirmed a pure and well crystalline product possessing wurtzite hexagonal phase. The as-synthesized ZnO nanocones were used as photocatalyst for the efficient photocatalytic degradation of acridine orange. The acridine orange was almost completely degraded within 105 minutes. This research demonstrates that the simply synthesized ZnO nanostructures could be efficient photocatalyst for the photocatalytic degradation of various organic dyes and chemicals.

18.
J Phys Condens Matter ; 23(7): 072201, 2011 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-21411871

RESUMEN

We have obtained the continuous radio frequency spectrum of water molecule relaxation using carbon nanotubes (CNT) as a high-speed nanoprobe. Three sets of characteristic time scales are clearly identified. Two sets are attributed to the electric-field-driven polarization of water molecules bound to CNTs and the collective relaxation of water layers in the vicinity of CNTs, respectively. The third set is appreciable only in air, and can be related to triplet oxygen relaxation.


Asunto(s)
Técnicas de Sonda Molecular , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestructura , Agua/química , Ensayo de Materiales , Tamaño de la Partícula , Ondas de Radio , Electricidad Estática
19.
J Dent Res ; 89(12): 1455-60, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20935279

RESUMEN

Er,Cr:YSGG lasers are used clinically in dentistry. The advantages of laser therapy include minimal thermal damage and the alleviation of pain. This study examined whether the Er,Cr:YSGG laser has in vivo and in vitro antinociceptive effects in itself. In capsaicin-evoked acute licking/shaking tests and Hargreaves tests, laser irradiation with an aerated water spray suppressed nociceptive behavior in mice. Laser irradiation attenuated TRPV1 activation by capsaicin in Ca(2+) imaging experiments with TRPV1-overexpressing cells and cultured trigeminal neurons. Therefore, the laser-induced behavioral changes are probably due to the loss of TRPV1 activity. TRPV4 activity was also attenuated, but limited mechanical antinociception by the laser was observed. The laser failed to alter the other receptor functions, which indicates that the antinociceptive effect of the laser is dependent on TRPV1. These results suggest that the Er,Cr:YSGG laser has analgesic effects via TRPV1 inhibition. Such mechanistic approaches may help define the laser-sensitive pain modality and increase its beneficial uses.


Asunto(s)
Láseres de Estado Sólido/uso terapéutico , Nociceptores/efectos de la radiación , Dolor/prevención & control , Canales Catiónicos TRPV/efectos de la radiación , Animales , Conducta Animal/efectos de los fármacos , Conducta Animal/efectos de la radiación , Bloqueadores de los Canales de Calcio/farmacología , Señalización del Calcio/efectos de los fármacos , Señalización del Calcio/efectos de la radiación , Capsaicina/farmacología , Dinoprostona/farmacología , Células HEK293 , Células HeLa , Calor , Humanos , Masculino , Ratones , Ratones Endogámicos ICR , Ratones Noqueados , Neuronas/efectos de los fármacos , Neuronas/efectos de la radiación , Nociceptores/efectos de los fármacos , Umbral del Dolor/efectos de la radiación , Tiempo de Reacción/efectos de la radiación , Rojo de Rutenio/farmacología , Fármacos del Sistema Sensorial/farmacología , Umbral Sensorial/efectos de la radiación , Canales Catiónicos TRPV/efectos de los fármacos , Sensación Térmica/efectos de la radiación , Tacto/efectos de la radiación , Nervio Trigémino/efectos de los fármacos , Nervio Trigémino/efectos de la radiación
20.
Br J Pharmacol ; 161(3): 707-20, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20880407

RESUMEN

BACKGROUND AND PURPOSE: Temperature-sensitive transient receptor potential ion channels (thermoTRPs) expressed in primary sensory neurons and skin keratinocytes play a crucial role as peripheral pain detectors. Many natural and synthetic ligands have been found to act on thermoTRPs, but little is known about endogenous compounds that inhibit these TRPs. Here, we asked whether resolvin D1 (RvD1), a naturally occurring anti-inflammatory and pro-resolving lipid molecule is able to affect the TRP channel activation. EXPERIMENTAL APPROACH: We examined the effect of RvD1 on the six thermoTRPs using Ca(2+) imaging and whole cell electrophysiology experiments using the HEK cell heterologous expression system, cultured sensory neurons and HaCaT keratinocytes. We also checked changes in agonist-specific acute licking/flicking or flinching behaviours and TRP-related mechanical and thermal pain behaviours using Hargreaves, Randall-Selitto and von Frey assay systems with or without inflammation. KEY RESULTS: RvD1 inhibited the activities of TRPA1, TRPV3 and TRPV4 at nanomolar and micromolar levels. Consistent attenuations in agonist-specific acute pain behaviours by immediate peripheral administration with RvD1 were also observed. Furthermore, local pretreatment with RvD1 significantly reversed mechanical and thermal hypersensitivity in inflamed tissues. CONCLUSIONS AND IMPLICATIONS: RvD1 was a novel endogenous inhibitor for several sensory TRPs. The results of our behavioural studies suggest that RvD1 has an analgesic potential via these TRP-related mechanisms.


Asunto(s)
Ácidos Docosahexaenoicos/fisiología , Dimensión del Dolor/efectos de los fármacos , Canales Catiónicos TRPV/fisiología , Canales de Potencial de Receptor Transitorio/fisiología , Animales , Células Cultivadas , Ácidos Docosahexaenoicos/farmacología , Relación Dosis-Respuesta a Droga , Humanos , Masculino , Ratones , Técnicas de Placa-Clamp/métodos , Canal Catiónico TRPA1 , Canales Catiónicos TRPV/antagonistas & inhibidores , Canales de Potencial de Receptor Transitorio/antagonistas & inhibidores
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