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

Bases de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Int J Mol Sci ; 23(22)2022 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-36430279

RESUMEN

The aim of this study is to synthesize phenethyl-conjugated chitosan oligosaccharide (COS) (abbreviated as ChitoPEITC) conjugates and then fabricate chlorin E6 (Ce6)-incorporated nanophotosensitizers for photodynamic therapy (PDT) of HCT-116 colon carcinoma cells. PEITC was conjugated with the amine group of COS. Ce6-incorporated nanophotosensitizers using ChitoPEITC (ChitoPEITC nanophotosensitizers) were fabricated by dialysis method. 1H nuclear magnetic resonance (NMR) spectra showed that specific peaks of COS and PEITC were observed at ChitoPEITC conjugates. Transmission electron microscope (TEM) confirmed that ChitoPEITC nanophotosensitizers have spherical shapes with small hydrodynamic diameters less than 200 nm. The higher PEITC contents in the ChitoPEITC copolymer resulted in a slower release rate of Ce6 from nanophotosensitizers. Furthermore, the higher Ce6 contents resulted in a slower release rate of Ce6. In cell culture study, ChitoPEITC nanophotosensitizers showed low toxicity against normal CCD986Sk human skin fibroblast cells and HCT-116 human colon carcinoma cells in the absence of light irradiation. ChitoPEITC nanophotosensitizers showed a significantly higher Ce6 uptake ratio than that of free Ce6. Under light irradiation, cellular reactive oxygen species (ROS) production of nanophotosensitizers was significantly higher than that of free Ce6. Especially, PEITC and/or ChitoPEITC themselves contributed to the production of cellular ROS regardless of light irradiation. ChitoPEITC nanophotosensitizers showed significantly higher PDT efficacy against HCT-116 cells than that of free Ce6. These results indicate that ChitoPEITC nanophotosensitizers have superior potential in Ce6 uptake, ROS production and PDT efficacy. In the HCT-116 cell-bearing mice tumor-xenograft model, ChitoPEITC nanophotosensitizers efficiently inhibited growth of tumor volume rather than free Ce6. In the animal imaging study, ChitoPEITC nanophotosensitizers were concentrated in the tumor tissue, i.e., fluorescence intensity in the tumor tissue was stronger than that of other tissues. We suggest that ChitoPEITC nanophotosensitizers are a promising candidate for the treatment of human colon cancer cells.


Asunto(s)
Carcinoma , Quitosano , Neoplasias del Colon , Humanos , Ratones , Animales , Especies Reactivas de Oxígeno , Neoplasias del Colon/tratamiento farmacológico , Oligosacáridos
2.
Small ; 12(43): 6012-6023, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27623489

RESUMEN

The sustained or controlled release of nitric oxide (NO) can be the most promising approach for the suppression or prevention of restenosis and thrombosis caused by stent implantation. The aim of this study is to investigate the feasibility in the potential use of layer-by-layer (LBL) coating with a NO donor-containing liposomes to control the release rate of NO from a metallic stent. Microscopic observation and surface characterizations of LBL-modified stents demonstrate successful LBL coating with liposomes on a stent. Release profiles of NO show that the release rate is sustained up to 5 d. In vitro cell study demonstrates that NO release significantly enhances endothelial cell proliferation, whereas it markedly inhibits smooth muscle cell proliferation. Finally, in vivo study conducted with a porcine coronary injury model proves the therapeutic efficacy of the NO-releasing stents coated by liposomal LBL technique, supported by improved results in luminal healing, inflammation, and neointimal thickening except thrombo-resistant effect. As a result, all these results demonstrate that highly optimized release rate and therapeutic dose of NO can be achieved by LBL coating and liposomal encapsulation, followed by significantly efficacious outcome in vivo.


Asunto(s)
Materiales Biocompatibles Revestidos/química , Vasos Coronarios/metabolismo , Liposomas/química , Óxido Nítrico/metabolismo , Stents , Adsorción , Animales , Vasos Coronarios/patología , Vasos Coronarios/ultraestructura , Fibrinógeno/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Masculino , Compuestos Nitrosos/química , Tecnicas de Microbalanza del Cristal de Cuarzo , Sus scrofa
3.
J Mater Sci Mater Med ; 27(4): 66, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26886814

RESUMEN

The aim of this study was to evaluate antiproliferative sirolimus- and antioxidative alpha-lipoic acid (ALA)-eluting stents using biodegradable polymer [poly-L-lactic acid (PLA)] in a porcine coronary overstretch restenosis model. Forty coronary arteries of 20 pigs were randomized into four groups in which the coronary arteries had a bare metal stent (BMS, n = 10), ALA-eluting stent with PLA (AES, n = 10), sirolimus-eluting stent with PLA (SES, n = 10), or sirolimus- and ALA-eluting stent with PLA (SAS, n = 10). A histopathological analysis was performed 28 days after the stenting. The ALA and sirolimus released slowly over 30 days. There were no significant differences between groups in the injury or inflammation score; however, there were significant differences in the percent area of stenosis (56.2 ± 11.78% in BMS vs. 51.5 ± 12.20% in AES vs. 34.7 ± 7.23% in SES vs. 28.7 ± 7.30% in SAS, P < 0.0001) and fibrin score [1.0 (range 1.0-1.0) in BMS vs. 1.0 (range 1.0-1.0) in AES vs. 2.0 (range 2.0-2.0) in SES vs. 2.0 (range 2.0-2.0) in SAS, P < 0.0001] between the four groups. The percent area of stenosis based on micro-computed tomography corresponded with the restenosis rates based on histopathological stenosis in different proportions in the four groups (54.8 ± 7.88% in BMS vs. 50.4 ± 14.87% in AES vs. 34.5 ± 7.22% in SES vs. 28.9 ± 7.22% in SAS, P < 0.05). SAS showed a better neointimal inhibitory effect than BMS, AES, and SES at 1 month after stenting in a porcine coronary restenosis model. Therefore, SAS with PLA can be a useful drug combination for coronary stent coating to suppress neointimal hyperplasia.


Asunto(s)
Reestenosis Coronaria/terapia , Stents Liberadores de Fármacos , Sirolimus/farmacología , Ácido Tióctico/farmacología , Animales , Fibroblastos , Ratas , Sirolimus/química , Porcinos , Ácido Tióctico/química , Resultado del Tratamiento
4.
J Mater Sci Mater Med ; 26(10): 251, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26438653

RESUMEN

The drug-eluting stent still has limitations such as thrombosis and inflammation. These limitations often occur in the absence of endothelialization. This study investigated the effects of WKYMVm- and sirolimus-coated stents on re-endothelialization and anti-restenosis. The WKYMVm peptide, specially synthesized for homing endothelial colony-forming cells, was coated onto a bare-metal stent with hyaluronic acid through a simple dip-coating method (designated HA-Pep). Thereafter, sirolimus was consecutively coated to onto the HA-Pep (designated Pep/SRL). The cellular response to stents by human umbilical-vein endothelial cells and vascular smooth-muscle cells was examined by XTT assay. Stents were implanted into rabbit iliac arteries, isolated 6 weeks post-implantation, and then subjected to histological analysis. The peptide was well attached to the surface of the stents and the sirolimus coating made the surface smooth. The release pattern for sirolimus was similar to that of commercial sirolimus-coated stents (57.2% within 7 days, with further release for up to 28 days). Endothelial-cell proliferation was enhanced in the HA-Pep group after 7 days of culture (38.2 ± 7.62%, compared with controls). On the other hand, the proliferation of smooth-muscle cells was inhibited in the Pep/SRL group after 7 days of culture (40.7 ± 6.71%, compared with controls). In an animal study, the restenosis rates for the Pep/SRL group (13.5 ± 4.50%) and commercial drug-eluting stents (Xience Prime™; 9.2 ± 7.20%) were lower than those for bare-metal stents (25.2 ± 4.52%) and HA-Pep stents (26.9 ± 3.88%). CD31 staining was incomplete for the bare-metal and Xience Prime™ groups. On the other hand, CD31 staining showed a consecutive linear pattern in the HA-Pep and Pep/SRL groups, suggesting that WKYMVm promotes endothelialization. These results indicate that the WKYMVm coating could promote endothelial healing, and consecutive coatings of WKYMVm and sirolimus onto bare-metal stents have a potential role in re-endothelialization and neointimal suppression.


Asunto(s)
Reestenosis Coronaria/prevención & control , Stents Liberadores de Fármacos , Oligopéptidos/administración & dosificación , Sirolimus/administración & dosificación , Animales , Materiales Biocompatibles/administración & dosificación , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Reestenosis Coronaria/patología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/patología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Arteria Ilíaca/efectos de los fármacos , Arteria Ilíaca/patología , Arteria Ilíaca/cirugía , Masculino , Ensayo de Materiales , Miocitos del Músculo Liso/efectos de los fármacos , Miocitos del Músculo Liso/patología , Neointima/patología , Neointima/prevención & control , Conejos , Ratas
5.
Biomed Mater ; 19(2)2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38364287

RESUMEN

The plasma technique has been widely used to modify the surfaces of materials. The purpose of this study was to evaluate the probability of controlling the prednisolone delivery velocity on a polylactic acid (PLA) surface modified by plasma surface treatment. Surface modification of PLA was performed at a low-pressure radio frequency under conditions of 100 W power, 50 mTorr chamber pressure, 100-200 sccm of flow rate, and Ar, O2, and CH4gases. The plasma surface-modified PLA was characterized using scanning emission microscope, x-ray photoelectron spectroscopy (XPS), and contact angle measurements.In vitroevaluations were performed to determine cellular response, drug release behavior, and anti-inflammatory effects. The PLA surface morphology was changed to a porous structure (with a depth of approximately 100 µm) and the surface roughness was also significantly increased. The XPS results demonstrated higher oxygenized carbon contents than those in the non-treated PLA group. The prednisolone holding capacity increased and the release was relatively prolonged in the surface-modified PLA group compared to that in the non-treated PLA group. In addition, cell migration and proliferation significantly increased after PLA treatment alone. The activity of cytokines such as cyclooxygenase-2 (COX-2), tumor necrosis factor-a (TNF-α), interleukin (IL-1ß), and IL-6 were considerably reduced in the plasma-treated and prednisolone holding group. Taken together, surface-modified PLA by plasma can provide an alternative approach to conventional physicochemical approaches for sustained anti-inflammatory drug release.


Asunto(s)
Poliésteres , Polímeros , Liberación de Fármacos , Polímeros/química , Poliésteres/química , Gases , Prednisolona
6.
Adv Sci (Weinh) ; 11(13): e2306798, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38240455

RESUMEN

Solution-processed low-bandgap semiconductors are crucial to next-generation infrared (IR) detection for various applications, such as autonomous driving, virtual reality, recognitions, and quantum communications. In particular, III-V group colloidal quantum dots (CQDs) are interesting as nontoxic bandgap-tunable materials and suitable for IR absorbers; however, the device performance is still lower than that of Pb-based devices. Herein, a universal surface-passivation method of InAs CQDs enabled by intermediate phase transfer (IPT), a preliminary process that exchanges native ligands with aromatic ligands on the CQD surface is presented. IPT yields highly stable CQD ink. In particular, desirable surface ligands with various reactivities can be obtained by dispersing them in green solvents. Furthermore, CQD near-infrared (NIR) photodetectors are demonstrated using solution processes. Careful surface ligand control via IPT is revealed that enables the modulation of surface-mediated photomultiplication, resulting in a notable gain control up to ≈10 with a fast rise/fall response time (≈12/36 ns). Considering the figure of merit (FOM), EQE versus response time (or -3 dB bandwidth), the optimal CQD photodiode yields one of the highest FOMs among all previously reported solution-processed nontoxic semiconductors comprising organics, perovskites, and CQDs in the NIR wavelength range.

7.
Opt Lett ; 38(4): 597-9, 2013 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-23455148

RESUMEN

We report on experimental realization of optical injection locking of a singly resonant continuous-wave optical parametric oscillator (OPO) based on a thermally induced waveguide in a magnesium-oxide doped periodically poled lithium niobate. An external cavity diode laser is used to control the frequency of the resonant signal output of the OPO at 795 nm. The key to successful injection locking was the improvement of the OPO spatial modes by a special operating condition with a thermally induced waveguide. The phase coherence of injection locking is confirmed by recording a high-contrast interference fringe between the injection laser and the OPO output. High-resolution measurement of the frequency spectrum of the nonresonant idler output by the delayed self-heterodyne technique shows that the spectral linewidth of the OPO is reduced from 4.5 to 0.4 MHz by injection locking. The full locking range is assumed to be less than 1.7 MHz.

8.
J Craniofac Surg ; 24(3): 818-21, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23714887

RESUMEN

BACKGROUND: Although double eyelid surgery is one of the most common cosmetic surgeries among Asians, there are few reports to confirm the physiology of eye blinking after such surgeries. This study analyzed eyelid dynamics and supratarsal crease appearance after double eyelid surgery using a high-speed digital camera to provide precise movement detection. METHODS: Twenty healthy volunteers and 15 patients who underwent double eyelid surgery with tarsodermal fixation were studied. Using the slow-motion replay setting of a high-speed digital camera, the patients' spontaneous eye blinking was analyzed for (1) blink duration, (2) peak eyelid velocity, (3) blink rate, and (4) supratarsal crease appearance. RESULTS: After double eyelid surgery, there were no significant differences in blink duration, peak eyelid velocity, or blink rate compared with the control group. Regarding supratarsal crease appearance, dynamic creases were created in 6 of 15 patients, whereas 9 patients showed static creases. CONCLUSIONS: Double eyelid surgery with tarsodermal fixation does not alter lid dynamics of spontaneous eye blinking. Furthermore, the tarsodermal fixation method, which is known to create a static crease, could also lead to the development of a dynamic crease.


Asunto(s)
Pueblo Asiatico , Blefaroplastia/métodos , Parpadeo/fisiología , Párpados/fisiología , Adulto , Análisis de Varianza , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Adulto Joven
9.
J Voice ; 37(1): 142.e5-142.e12, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33199080

RESUMEN

OBJECTIVES: The purposes of this study were (1) to analyze the usefulness of self-report questionnaires, acoustic analysis, and auditory perceptual assessment for screening voice problems; and (2) to develop a new model for predicting a comprehensive voice severity using multi-assessment. METHODS: A total of 306 voice samples were analyzed in this study (typical group, n = 72; dysphonia group, n = 234). We performed a receiver operating characteristic analysis to determine the cutoff values of auditory perceptual assessments (visual analog scale), acoustic parameters (spectral- and cepstral-based analyses), and self-report questionnaires for screening voice disorders. We also performed a stepwise multiple regression analysis to verify which combination of parameters (acoustic parameters, and self-report questionnaires) could best predict perceived voice severity. RESULTS: We verified that most of the variables analyzed were useful for voice evaluation, and found to be useful for screening voice problems. Of these, a five-variable model was a useful to predict perceived voice severity (mean R2 = .807). The five-variable model consisted of acoustic parameters based on cepstral analysis (cepstral peak prominences in connected speech and sustained vowel task, and low versus high-frequency spectral energy ratio in connected speech task) and self-report questionnaires (total score of the Voice Handicap Index, and rumination score of the Voice Catastrophization Index). CONCLUSION: We verified that most of the variables were useful for screening dysphonia and five-variable model was a useful to predict perceived voice severity. The five-variable model could be used as an objective criterion for predicting voice severity.


Asunto(s)
Disfonía , Voz , Humanos , Disfonía/diagnóstico , Acústica del Lenguaje , Habla , Acústica , Medición de la Producción del Habla , Índice de Severidad de la Enfermedad
10.
Opt Express ; 20(24): 26308-16, 2012 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-23187485

RESUMEN

We report on the transfer of statistical characteristics from writing and reading coupling light to stored and retrieved probe light pulses in a Λ-type electromagnetically induced transparency (EIT) scheme based on the 5S(1/2)-5P(1/2) transition of (87)Rb atoms. When the coherent probe laser pulse was stored in the EIT medium using the pseudo-thermal coupling light, the characteristics of the pseudo-thermal writing coupling light were transferred to the stored probe laser pulse because of the strong correlation between the probe and coupling light in the EIT medium. The photon number statistics of the retrieved probe light changed from Poisson distribution to Bose-Einstein distribution. Additionally, we measured the change in the properties of the retrieved light pulse due to the photon number statistics of the pseudo-thermal reading coupling light.


Asunto(s)
Simulación por Computador , Diseño Asistido por Computadora , Luz , Dispositivos Ópticos , Fotones , Dispersión de Radiación , Procesamiento de Señales Asistido por Computador/instrumentación , Diseño de Equipo , Humanos
11.
J Mater Sci Mater Med ; 23(5): 1259-69, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22389099

RESUMEN

Heparinization of surfaces has proven a successful strategy to prevent thrombus formation. Inspired by the composition of adhesive proteins in mussels, the authors used dopamine to immobilize heparin on a stent surface. This study aimed to assess the thromboresistant and endothelialization effects of dopamine-mediated heparin (HPM) coating on a stent material surface. The HPM was synthesized by bonding dopamine and heparin chemically. Cobalt-chromium (Co-Cr) alloy disks were first placed in the HPM solution and applied to surface stability then underwent thromboresistant tests and human umbilical vein endothelial cells (HUVEC) cytotoxicity assays. The results showed not only thromboresistant activity and a stable state of heparin on the surfaces after investigation with toluidine blue and thrombin activation assay but also proliferation of HUVEC in vitro. Studies on animals showed that the HPM-coated stent has no obvious inflammation response and increasing of restenosis rate compared to the bare metal stent (BMS) indicating good biocompatibility as well as safety in its in vivo application. Moreover, improving the endothelial cell (EC) proliferation resulted in a higher strut-covering rate (i.e., endothelialization) with shuttle-shaped EC in the HPM-coated stent group compared to that of the BMS group. These results suggest that this facile coating approach could significantly promote endothelialization and offer greater safety than the BMS for its much improved thromboresistant property. Moreover, it may offer a platform for conjugating secondary drugs such as anti-proliferative drugs.


Asunto(s)
Dopamina/farmacología , Stents Liberadores de Fármacos , Endotelio Vascular/efectos de los fármacos , Heparina/farmacología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Trombosis/prevención & control , Animales , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Dopamina/administración & dosificación , Dopamina/química , Dopamina/farmacocinética , Endotelio Vascular/crecimiento & desarrollo , Endotelio Vascular/fisiología , Heparina/administración & dosificación , Heparina/farmacocinética , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/fisiología , Humanos , Neovascularización Fisiológica/efectos de los fármacos , Neovascularización Fisiológica/fisiología , Conejos
12.
J Opt Soc Am A Opt Image Sci Vis ; 28(4): 560-5, 2011 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-21478950

RESUMEN

We demonstrated tunable mixed classical light (TMCL) using a mixture of a laser and a pseudothermal light. The TMCL was generated by adjusting the photon number ratio of a laser and a pseudothermal light. The photon number statistics of the TMCL continuously changed from the Poisson distribution to the Bose-Einstein distribution. The g((2)) (0) value of the TMCL was measured using the Hanbury Brown-Twiss method, and we could arbitrarily control the g((2)) (0) value between 1.0 and 1.7. The experimental g((2)) (0) value of the TMCL as a function of the photon number ratio of the two light sources was in close agreement with the calculated result.

13.
J Voice ; 35(2): 328.e11-328.e22, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31640898

RESUMEN

OBJECTIVES: This study investigated whether there are differences in the discriminatory power of cepstral analysis according to the voiced-segment extraction method and voice tasks used for identifying dysphonic and normophonic Korean individuals. MATERIALS AND METHODS: A total of 2,863 subjects (2,595 subjects with and 268 subjects without dysphonia) were included in this study. The 3-second sustained vowel (SV) /a/ and one sentence of "Sanchaek" were edited and analyzed using Praat scripts. Cepstral analyses (cepstral peak prominence [CPP], smoothed cepstral peak prominence [CPPS], and low/high spectral ratio [LHRatio]) were performed using three voice tasks, namely, SV, continuous speech (CS), and extracted continuous speech (EXT) samples. Additionally, auditory-perceptual (A-P) assessments were performed by three speech language pathologists. RESULTS: Significant differences were found between dysphonic and normophonic voice groups for all cepstral parameters, except the LHRatio_EXT. Cepstral measurements of both SV and CS were highly correlated with A-P ratings. Furthermore, the diagnostic predictive power of CPP and CPPS for CS using the area under the receiver operating characteristic curve (AUC) was >0.919, the positive likelihood ratio (LR+) was ≥6.85, and the negative likelihood ratio (LR-) was ≤0.23. Additionally, for EXT, the AUC was >0.816, LR+ was 3.10, and LR- was ≤0.33. CONCLUSION: Both CS and EXT can predict dysphonia relatively well (r > 0.816). EXT showed lower predictability than the original sample (CS) analysis. Subsequent studies should implement voiced-segment extraction methods using various algorithms.


Asunto(s)
Disfonía , Lenguaje , Disfonía/diagnóstico , Humanos , República de Corea , Acústica del Lenguaje , Medición de la Producción del Habla , Calidad de la Voz
14.
Materials (Basel) ; 14(24)2021 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-34947382

RESUMEN

Corrosion of nitinol (NiTi) is a major factor in the failure of implantable materials. Recently, as the importance of corrosion of metals has increased, testing according to international guidelines is essential. The purpose of this study was to evaluate the corrosion resistance of NiTi wire through heat treatment and passivation process. In this study, NiTi wire used two commercially available products and a self-manufactured stent. Experimental consideration was carried out according to ASTM standards. Heat treatment was carried out in an air or a salt furnace, and the corrosion was measured after additional process, such as passivation and scratch tests. As a result, the metal potential was rapidly decreased in the air furnace group. On the other hand, the potential of wires was dramatically increased in the salt furnace group compared to the air furnace group. The dislocation decreased below the acceptance criteria (>600 mV) within 60 s of heat treatment time in the air furnace. Moreover, the potential was dramatically improved, even after only 20 min of passivation treatment (1076 mV, 442% compared to the non-passivated group), and it continued to rise until 180 min. This phenomenon was similarly observed in the group of self-manufactured stents. The potential slightly decreased by the scratch process (93.1%) was significantly reduced by the air furnace process (315 mV, 24.4% of the nontreated group). In the passivated group of the air furnace sample with reduced potential, the potential was restored to the level before the air furnace (scratch stage) (1032 mV). In conclusion, the heat treatment is preferably carried out in a salt furnace rather than an air furnace, and the passivation process can be an advantageous tool to improve corrosion resistance by suppressing the oxidation process.

15.
Biomater Res ; 25(1): 30, 2021 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-34565474

RESUMEN

OBJECTIVE: Various surface modification techniques that can further improve the function and usability of stainless steel as a medical device have been reported. In the present study, the physical and biological properties of nanoporous stainless steel as well as its usefulness for drug delivery were assessed. METHODS: The specimen was prepared with a circular disk shape (15 mm in diameter and 1 mm in thickness). The disk was subjected to electropolishing at a constant voltage of 20 V and 10 A for 10 min in an acidic environment (50% H2SO4). Everolimus (EVL) was used as a testing drug for drug-loading capacity of the material surface and release kinetics. The physiobiological properties of the material were assessed using platelet adhesion, and smooth muscle cell (SMC) adhesion, migration, and proliferation assays. RESULTS: The surface roughness of the postpolishing group was greater than that of the nonpolishing group. Platelet adhesion and SMC adhesion and migration were inhibited in the postpolishing group compared to those in the prepolishing group. In the postpolishing group, the total amount of EVL on the surface (i.e., drug storage rate) was higher and the drug release rate was lower, with half the amount of the EVL released within 4 days compared with only 1 day for that of the prepolishing group. CONCLUSION: Taken together, this stainless steel with a nanoporous surface could be used as a medical device for controlling cellular responses and carrying drugs.

16.
Opt Express ; 18(2): 1389-97, 2010 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-20173966

RESUMEN

We present the transformation of electromagnetically induced transparency (EIT) into narrow enhanced absorption with an on-resonant standing-wave coupling field in the 5S(1/2)-5P(1/2) transition of the Lambda-type system of (87)Rb atoms. When a coupling laser field was changed from a travelling-wave to a standing-wave that was made by adding a counter-propagating L(C) laser, the transmittance spectrum of the L(P) laser transformed the typical EIT into dramatically enhanced absorption, and a Bragg reflection signal was generated by the periodic modulation of atomic absorption. The reflected probe laser corresponding to a Bragg reflection was measured to be approximately 11.5% of the power of the incident probe laser. We analyzed the enhanced absorption signal and Bragg reflection spectrum as a function of the power and frequency detuning of the coupling laser.


Asunto(s)
Dispositivos Ópticos , Refractometría/instrumentación , Radioisótopos de Rubidio/química , Radioisótopos de Rubidio/efectos de la radiación , Absorción , Campos Electromagnéticos , Diseño de Equipo , Análisis de Falla de Equipo , Gases/química , Gases/efectos de la radiación
17.
Opt Express ; 18(19): 19693-9, 2010 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-20940864

RESUMEN

We report an experimental demonstration of slow and superluminal propagation of pseudo-thermal (chaotic) light in the Λ-type system of the 5S(1/2)-5P(1/2) transition of (87)Rb atom. The slowed propagation of pulsed pseudo-thermal light was demonstrated in an electromagnetically-induced transparency medium while the superluminal propagation was demonstrated with the enhanced absorption scheme where the coupling field takes the form of a standing wave.We have also demonstrated that the photon number statistics of the pseudo-thermal light is preserved for both the subluminal and superluminal cases.


Asunto(s)
Luz , Modelos Químicos , Radioisótopos de Rubidio/química , Simulación por Computador , Dispersión de Radiación
18.
Pharmacology ; 86(5-6): 327-35, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21109762

RESUMEN

BACKGROUND/AIMS: Cartilage oligomeric matrix protein (COMP)-angiopoietin 1 (Ang1) is a soluble and stable form of Ang1 which plays important roles in vessel formation and the survival of endothelial cells, neurons and cardiomyocytes. However, the effects of COMP-Ang1 on the survival of mesenchymal cells are unknown. Mesenchymal cells have been transplanted with some scaffolds for bone tissue regeneration, but they occasionally underwent cell death due to a lack of nutrient supply. This study examined the effects of COMP-Ang1 on the survival of mesenchymal cells under nutrient-deprived conditions. METHODS: Primary and C3H10T1/2 mesenchymal cells were cultured under serum deprivation with or without COMP-Ang1. The effects of COMP-Ang1 on mesenchymal cell survival and its molecular mechanism were determined using a viability test, RT-PCR, Western blotting and fluorescence-activated cell sorting analysis. RESULTS AND CONCLUSION: COMP-Ang1 inhibited the nutrient-deprived apoptotic cell death of mesenchymal cells through the Akt, p38 and extracellular-signal-regulated kinase (ERK) pathways. In addition, COMP-Ang1 reversed the nutrient-deprived suppression of cyclin D1 mRNA expression. These results suggest that COMP-Ang1 has a protective role in the survival of nutrient-deprived mesenchymal cells. The use of COMP-Ang1 with some scaffolds might be useful for bone tissue engineering.


Asunto(s)
Apoptosis/efectos de los fármacos , Células Madre Mesenquimatosas/efectos de los fármacos , Proteínas Recombinantes de Fusión/farmacología , Animales , Western Blotting , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Ciclina D1/genética , Humanos , Células Madre Mesenquimatosas/metabolismo , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
19.
Biomater Res ; 24: 4, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31998531

RESUMEN

BACKGROUND: The aim of this study was to characterize the mechanical and physio-biological properties of peptide-coated stent (PCS) compared to commercialized drug-eluting stents (DESs). METHODS: WKYMVm (Trp-Lys-Tyr-Met-Val-D-Met), a stimulating peptide for homing endothelial colony-forming cell was specially synthesized and coated to bare metal stent (BMS) by dopamine-derived coordinated bond. Biological effects of PCS were investigated by endothelial cell proliferation assay and pre-clinical animal study. And mechanical properties were examined by various experiment. RESULTS: The peptide was well-coated to BMS and was maintained and delivered to 21 and 7 days in vitro and in vivo, respectively. Moreover, the proliferation of endothelial cell in PCS group was increased (approximately 36.4 ± 5.77%) in PCS group at 7 day of culture compare to BMS. Although, the radial force of PCS was moderated among study group. The flexibility of PCS was (0.49 ± 0.082 N) was greatest among study group. PCS did not show the outstanding performance in recoil and foreshortening test (3.1 ± 0.22% and 2.1 ± 0.06%, respectively), which was the reasonable result under the guide line of FDA (less than 7.0%). The nominal pressure (3.0 mm in a diameter) of PCS established by compliance analysis was 9 atm. The changing of PCS diameter by expansion was similar to other DESs, which is less than 10 atm of pressure for the nominal pressure. CONCLUSIONS: These results suggest that the PCS is not inferior to commercialized DES. In addition, since the PCS was fabricated as polymer-free process, secondary coating with polymer-based immunosuppressive drugs such as -limus derivatives may possible.

20.
J Voice ; 34(3): 489.e11-489.e19, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-30527706

RESUMEN

OBJECTIVES: The acoustic voice quality index (AVQI) is a specific acoustic indicator designed to objectively estimate dysphonia severity and measure the values of acoustic parameters based on the diagnostic category. This study compared the performance of two AVQI versions (2.02 and 3.01, v2 and v3) and PraatCPPS using a voice sample of Korean population. MATERIALS AND METHODS: Voice samples for sustained vowel and connected speech were elicited from 2257 patients across 14 diagnostic categories. Auditory-perceptual (A-P) assessments of dysphonia severity were compared to acoustic parameters of severity derived from two versions of the AVQI (v2 and v3) as well as the PraatCPPS. RESULTS: The AVQI-estimated severity (v2 and v3) and PraatCPPS severity for concatenated voice samples strongly correlated with each other and were significantly associated with A-P ratings. The AVQI (v2 and v3) and PraatCPPS showed high reliability in differentiating between pathological voice disorders. CONCLUSION: The AVQI (v2 and v3) and PraatCPPS were strongly correlated with the A-P ratings and provided valid estimates of dysphonia severity. However, the associations of the A-P ratings with the AVQIv2 were significantly stronger than those with the AVQIv3 and PraatCPPS, suggesting that the V2 outperformed the V3 and PraatCPPS.


Asunto(s)
Acústica , Disfonía/diagnóstico , Acústica del Lenguaje , Medición de la Producción del Habla , Calidad de la Voz , Disfonía/fisiopatología , Femenino , Humanos , Masculino , Variaciones Dependientes del Observador , Valor Predictivo de las Pruebas , Índice de Severidad de la Enfermedad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA