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1.
Toxins (Basel) ; 16(8)2024 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-39195757

RESUMEN

Botulinum neurotoxin-A (BoNT-A) injections are effective for focal spasticity. However, the impact on muscle strength is not established. This study aimed to investigate the effect of BoNT-A injections on muscle strength in adult neurological conditions. Studies were included if they were Randomised Controlled Trials (RCTs), non-RCTs, or cohort studies (n ≥ 10) involving participants ≥18 years old receiving BoNT-A injection for spasticity in their upper and/or lower limbs. Eight databases (CINAHL, Cochrane, EMBASE, Google Scholar, Medline, PEDro, Pubmed, Web of Science) were searched in March 2024. The methodology followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered in the Prospective Register of Systematic Reviews (PROSPERO: CRD42022315241). Quality was assessed using the modified Downs and Black checklist and the PEDro scale. Pre-/post-injection agonist, antagonist, and global strength outcomes at short-, medium-, and long-term time points were extracted for analysis. Following duplicate removal, 8536 studies were identified; 54 met the inclusion criteria (3176 participants) and were rated as fair-quality. Twenty studies were analysed as they reported muscle strength specific to the muscle injected. No change in agonist strength after BoNT-A injection was reported in 74% of the results. Most studies' outcomes were within six weeks post-injection, with few long-term results (i.e., >three months). Overall, the impact of BoNT-A on muscle strength remains inconclusive.


Asunto(s)
Toxinas Botulínicas Tipo A , Espasticidad Muscular , Fuerza Muscular , Fármacos Neuromusculares , Humanos , Espasticidad Muscular/tratamiento farmacológico , Espasticidad Muscular/fisiopatología , Toxinas Botulínicas Tipo A/administración & dosificación , Toxinas Botulínicas Tipo A/uso terapéutico , Fuerza Muscular/efectos de los fármacos , Fármacos Neuromusculares/uso terapéutico , Fármacos Neuromusculares/administración & dosificación , Adulto , Enfermedades del Sistema Nervioso/tratamiento farmacológico , Músculo Esquelético/efectos de los fármacos
2.
J Sep Sci ; 46(16): e2300160, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37269050

RESUMEN

Siegesbeckiae Herba, a traditional Chinese medicine, originates from Siegesbeckia orientalis, S. glabrescens, and S. pubescens in the Pharmacopoeia of the People's Republic of China. However, accurate identification of decoction pieces from the three plants remains a challenge. In this study, 26 batches of Siegesbeckiae Herba were identified by deoxyribonucleic acid barcoding, and their chemical compositions were determined using ultra-performance liquid chromatography-electrospray ionization-quadrupole time of flight-mass spectrometry. The results showed that the internal transcribed spacer 2 and internal transcribed spacer 1-5.8 S- internal transcribed spacer 2 sequences could distinguish three species. In total, 48 compounds were identified including 12 marker compounds screened for three species using the partial least square discriminant analysis. Among these, two diterpenoids 16-O-malonylkirenol and 15-O-malonylkirenol, and a novel diterpenoid 15,16-di-O-malonylkirenol were isolated and identified. A convenient method for the identification of Siegesbeckiae Herba was established using kirenol and 16-O-acetlydarutoside as control standards by thin-layer chromatography. Unexpectedly, none of the batches of S. orientalis contained kirenol, which did not meet the quality standards of Siegesbeckiae Herba, suggesting that the rationality of kirenol as a quality marker for S. orientalis should be further investigated. The results of this study will contribute to the quality control of Siegesbeckiae Herba.


Asunto(s)
Medicamentos Herbarios Chinos , Espectrometría de Masa por Ionización de Electrospray , Humanos , Espectrometría de Masa por Ionización de Electrospray/métodos , Medicamentos Herbarios Chinos/química , Cromatografía Liquida/métodos , ADN , Cromatografía Líquida de Alta Presión/métodos
3.
Phys Ther Sport ; 58: 68-73, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36223690

RESUMEN

OBJECTIVES: To determine whether individuals with and without Chronic Ankle Instability (CAI) can improve their ankle movement discrimination sensitivity by repeated exposure to an ankle proprioceptive task requiring landing. DESIGN: A repeated-measures study. SETTING: University laboratory. PARTICIPANTS: 24 university students, 11 with CAI and 13 without CAI. MAIN OUTCOME MEASURES: Ankle proprioception was measured using the Ankle Inversion Discrimination Apparatus for Landing (AIDAL) over 3 occasions: AIDAL-1 and AIDAL-2 separated with a 10-min interval, and AIDAL-3 at 24 h post AIDAL-2. RESULTS: Better Cumberland Ankle Instability Tool (CAIT) questionnaire scores were correlated with higher AIDAL scores (rho = 0.465, p = 0.022). Two-way ANOVA showed a significant CAI main effect for step landing ankle inversion proprioception, with CAI worse (F = 8.410, p = 0.008), but the Time main effect across the 3 AIDAL tests was not significant (F = 1.552, p = 0.223). CONCLUSIONS: The AIDAL assessment was sensitive in terms of discriminating between individuals with or without CAI. However, the step-down component of the AIDAL proprioceptive task was possibly too challenging. For CAI, physical therapy exercises should take into account the difficulty of the training task, so that a demonstrable learning effect can be achieved.


Asunto(s)
Traumatismos del Tobillo , Inestabilidad de la Articulación , Humanos , Tobillo , Articulación del Tobillo , Inestabilidad de la Articulación/terapia , Propiocepción , Enfermedad Crónica
4.
Percept Mot Skills ; 129(6): 1736-1748, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36113161

RESUMEN

While investigators have often compared ankle proprioception between groups with and without chronic ankle instability (CAI), findings have been inconsistent. Possibly this is because ankle proprioceptive impairment in this population is task-specific. Thus, we aimed to compare ankle inversion proprioception in individuals with and without CAI in two task conditions: (i) when standing (not challenging) and (ii) when on a step-down landing (minimally-challenging). Ankle inversion proprioception was measured in both conditions for 38 recreational sport player volunteers with CAI (n = 19) and without CAI (n = 19). We used the Active Movement Extent Discrimination Apparatus (AMEDA) for the standing condition and the Ankle Inversion Discrimination Apparatus-Landing (AIDAL) for step-down landing. From analysis of variance (ANOVA) tests, CAI and non-CAI participants performed equally well on the AMEDA when standing; but the CAI group performed significantly worse than the non-CAI group on the AIDAL step-down landing task (p = 0.03). Within the non-CAI group, the AIDAL proprioceptive scores, as area under the receiver operating characteristics curve (AUC), were significantly higher than their AMEDA AUC scores (p = 0.03), while there was no significant difference between AIDAL and AMEDA AUC scores in the CAI group. Cumberland Ankle Instability Tool CAIT scores were significantly correlated with AIDAL scores (Spearman's rho = 0.391, p = 0.015), but not with the AMEDA scores; and there was no significant correlation between the AIDAL and AMEDA scores. Thus, an ankle inversion proprioceptive deficit was evident for persons with CAI on the step-down AIDAL, and in a dose-response way, but not evident on the standing AMEDA, suggesting that ankle proprioceptive impairment is task-specific. Selected proprioceptive tests must present some minimal degree of challenge to the ankle joint in a functional task in order to differentiate CAI from non-CAI participants.


Asunto(s)
Tobillo , Inestabilidad de la Articulación , Humanos , Articulación del Tobillo/fisiología , Propiocepción/fisiología , Posición de Pie
5.
J Sci Med Sport ; 24(9): 894-899, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34016535

RESUMEN

OBJECTIVES: To determine the effect of different lengths of kinesiology tape (KT) on ankle inversion proprioceptive performance in individuals with or without chronic ankle instability (CAI). DESIGN: A repeated measures study. METHODS: Fifteen participants with unilateral CAI and fifteen participants with no CAI volunteered. The Ankle Inversion Discrimination Apparatus for Landing (AIDAL) was used to measure ankle proprioceptive acuity. All participants were tested under four KT conditions: no tape (baseline), short tape length (only foot and ankle complex involved), mid length (below the knee) and long length (above the knee) taping. After the baseline test, participants underwent the 3 different taping tests in a random order. RESULTS: Repeated measures ANOVA indicated that, compared to those without CAI, individuals with CAI performed significantly worse across the 4 different conditions (F = 8.196, p = 0.008). There was a significant KT main effect (F = 7.489, p < 0.001) and a significant linear effect (F = 17.083, p < 0.001), suggesting that KT significantly improved ankle proprioceptive performance in landing, and with longer tape length there was greater proprioceptive enhancement. Post-hoc analysis showed that for the CAI group, both mid length (p = 0.013, 95%CI = -0.063, -0.009) and long length (p = 0.010, 95%CI = -0.067, -0.011) taping can significantly improve ankle proprioceptive performance compared to no tape, whereas for the non-CAI group, ankle proprioceptive acuity was significantly improved only with long length taping (p = 0.007, 95%CI = -0.080, -0.015). CONCLUSIONS: KT can be used to improve ankle inversion proprioceptive performance during landing in both individuals with and without CAI and increasing tape length may achieve greater proprioceptive improvement.


Asunto(s)
Articulación del Tobillo/fisiopatología , Cinta Atlética , Inestabilidad de la Articulación/fisiopatología , Propiocepción/fisiología , Análisis de Varianza , Enfermedad Crónica , Femenino , Humanos , Inestabilidad de la Articulación/etiología , Masculino , Movimiento/fisiología , Esguinces y Distensiones/complicaciones , Adulto Joven
6.
J Sci Med Sport ; 24(7): 665-669, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33632662

RESUMEN

BACKGROUND: Research evidence has suggested that a more sensitive ankle proprioceptive testing method with higher ecological validity is needed for assessing proprioceptive deficits in individuals with chronic ankle instability (CAI). OBJECTIVES: (1) To determine the test-retest reliability of a novel ankle proprioception assessment tool, the Ankle Inversion Discrimination Apparatus for Landing (AIDAL); (2) To assess whether AIDAL scores were sufficiently sensitive to detect proprioceptive deficits in chronic ankle instability (CAI); and (3) To examine whether AIDAL scores correlated with Cumberland Ankle Instability Tool (CAIT) scores. DESIGN: Cross-sectional study. METHODS: The AIDAL was purpose-built to assess ankle discrimination in four positions of ankle inversion (10°, 12°, 14° and 16°) upon landing from a 10cm drop. Area Under the Receiver Operating Curve (AUC) was employed as the ankle proprioceptive discrimination score. Seven-day test-retest reliability was evaluated with 23 university students (12 CAI and 11 non-CAI), and another 36 university students (18 CAI and 18 non-CAI) were in the comparison study. RESULTS: The test-retest reliability ICC score for the whole group was 0.763 (95% CI=0.519-0.892), which showed an excellent reliability level. ICC (3,1) was 0.701 for the non-CAI group (95%CI=0.210-0.910) and 0.804 for the CAI group (95%CI=0.451-0.939). The CAI group performed at a significantly lower level on the AIDAL assessment than the non-CAI group (0.777±0.05 vs. 0.815±0.05, F=5.107, p=0.03). The discriminative AUC value for the AIDAL test was 0.756 with a cut point of 0.819 (sensitivity=0.733, specificity=0.800). The MDC90 scores for CAI and non-CAI groups were both 0.04. Spearman's correlation showed that the CAIT scores were significantly correlated with the ankle proprioceptive discrimination scores (rho=0.401, p=0.015). CONCLUSION: The AIDAL showed good test-retest reliability for both non-CAI and CAI groups. Measuring ankle inversion proprioception during landing may be important for assessing the outcomes of CAI rehabilitation, as proprioceptive performance obtained from the AIDAL was significantly correlated with severity of functional ankle instability CAIT scores.


Asunto(s)
Traumatismos del Tobillo/fisiopatología , Tobillo/fisiopatología , Prueba de Esfuerzo/instrumentación , Inestabilidad de la Articulación/fisiopatología , Propiocepción , Traumatismos del Tobillo/diagnóstico , Enfermedad Crónica , Estudios Transversales , Prueba de Esfuerzo/métodos , Femenino , Humanos , Inestabilidad de la Articulación/diagnóstico , Masculino , Psicometría , Reproducibilidad de los Resultados , Análisis y Desempeño de Tareas , Adulto Joven
7.
J Sports Med Phys Fitness ; 61(4): 592-599, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32744048

RESUMEN

BACKGROUND: The purpose of the current study was to assess the reliability and validity of the lower extremity functional test (LEFT) for predicting low back and lower limb injury in active athletes. METHODS: Seventy athletes (45M, 25F; mean age: 21±2 years) from seven different sports volunteered. The LEFT was a battery of five weight-bearing functional movements involving different movement planes, directions, modes, and at varying intensities. Both legs were assessed in a random order and each athlete was given both movement quality and associated symptom scores. Intratester, intrarater and inter-rater reliability were evaluated. Participants were followed up for 12 months, and their exposure to sport and subsequent injuries were recorded. Independent samples t-tests were performed to determine if a significant difference existed in LEFT scores between injured and non-injured athletes. Receiver operating characteristic (ROC) curve analysis was employed to assess the instrument's capacity to predict injury. RESULTS: The intratester reliability ICC2, 1 was 0.875. The ICC2, 3 of intrarater reliability was 0.953 and the inter-rater reliability was 0.949, respectively. Nineteen participants had an injury in the low back or lower limb within the following 12 months. Injured athletes had significant lower movement quality and symptom scores of the LEFT than non-injured (t=4.278, P=0.000, Cohen's d=1.2; t=3.654, P=0.001, Cohen's d=1.3, respectively). When movement quality or symptom score alone was included in the ROC analysis, the area under the ROC curve (AUC) scores were 0.772 (P=0.000, 95% CI: 0.653-0.891) and 0.771 (P=0.001, 95% CI: 0.638-0.905), respectively. When movement quality and symptom scores were combined to predict injury, the AUC discrimination score was 0.853 (P=0.000, 95% CI: 0.754-0.953), resulting in 85.3% of cases being correctly predicted as low back or lower limb injured/noninjured. CONCLUSIONS: The findings from the current study suggest that the LEFT appears to be a reliable and valid functional assessment tool for predicting low back or lower limb injury risk in these college athletes, especially when movement quality and symptom scores were used in combination.


Asunto(s)
Traumatismos en Atletas/prevención & control , Traumatismos de la Espalda/prevención & control , Prueba de Esfuerzo/métodos , Extremidad Inferior/fisiología , Adulto , Femenino , Humanos , Masculino , Movimiento , Curva ROC , Medición de Riesgo , Adulto Joven
8.
Environ Sci Pollut Res Int ; 26(33): 34027-34038, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30232775

RESUMEN

The objectives of this study were to (1) conduct laboratory bench and column experiments to determine the oxidation kinetics and optimal operational parameters for trichloroethene (TCE)-contaminated groundwater remediation using potassium permanganate (KMnO4) as oxidant and (2) to conduct a pilot-scale study to assess the efficiency of TCE remediation by KMnO4 oxidation. The controlling factors in laboratory studies included soil oxidant demand (SOD), molar ratios of KMnO4 to TCE, KMnO4 decay rate, and molar ratios of Na2HPO4 to KMnO4 for manganese dioxide (MnO2) production control. Results show that a significant amount of KMnO4 was depleted when it was added in a soil/water system due to the existence of natural soil organic matters. The presence of natural organic material in soils can exert a significant oxidant demand thereby reducing the amount of KMnO4 available for the destruction of TCE as well as the overall oxidation rate of TCE. Supplement of higher concentrations of KMnO4 is required in the soil systems with high SOD values. Higher KMnO4 application resulted in more significant H+ and subsequent pH drop. The addition of Na2HPO4 could minimize the amount of produced MnO2 particles and prevent the clogging of soil pores, and TCE oxidation efficiency would not be affected by Na2HPO4. To obtain a complete TCE removal, the amount of KMnO4 used to oxidize TCE needs to be higher than the theoretical molar ratio of KMnO4 to TCE based on the stoichiometry equation. Relatively lower oxidation rates are obtained with lower initial TCE concentrations. The half-life of TCE decreased with increased KMnO4 concentrations. Results from the pilot-scale study indicate that a significant KMnO4 decay occurs after the injection due to the reaction of KMnO4 with soil organic matters, and thus, the amount of KMnO4, which could be transported from the injection point to the downgradient area, would be low. The effective influence zone of the KMnO4 oxidation was limited to the KMnO4 injection area (within a 3-m radius zone). Migration of KMnO4 to farther downgradient area was limited due to the reaction of KMnO4 to natural organic matters. To retain a higher TCE removal efficiency, continuous supplement of high concentrations of KMnO4 is required. The findings would be useful in designing an in situ field-scale ISCO system for TCE-contaminated groundwater remediation using KMnO4 as the oxidant.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Agua Subterránea/química , Permanganato de Potasio/química , Tricloroetileno/química , Contaminantes Químicos del Agua/química , Compuestos de Manganeso , Oxidantes , Oxidación-Reducción , Óxidos , Suelo , Tricloroetileno/análisis , Contaminantes Químicos del Agua/análisis
9.
Environ Sci Pollut Res Int ; 25(6): 5231-5242, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28528500

RESUMEN

The extraction efficiency of heavy metals from soils using three forms of gamma poly-glutamic acid (γ-PGA) as the washing agents was investigated. Controlling factors including agent concentrations, extraction time, pH, and liquid to soil ratio were evaluated to determine the optimum operational conditions. The distribution of heavy metal species in soils before and after extraction processes was analyzed. Up to 46 and 74% of heavy metal removal efficiencies were achieved with one round and a sequential extraction process using H-bonding form of γ-PGA (200 mM) with washing time of 40 min, liquid to solid ratio of 10 to 1, and pH of 6. Major heavy metal removal mechanisms were (1) γ-PGA-promoted dissolution and (2) complexation of heavy metal with free carboxyl groups in γ-PGA, which resulted in heavy metal desorption from soils. Metal species on soils were redistributed after washing, and soils were remediated without destruction of soil structures and productivity.


Asunto(s)
Descontaminación/métodos , Restauración y Remediación Ambiental/métodos , Metales Pesados/química , Ácido Poliglutámico/química , Contaminantes del Suelo/química , Adsorción , Quelantes/química , Metales Pesados/análisis , Ácido Poliglutámico/análogos & derivados , Suelo/química , Contaminantes del Suelo/análisis , Solubilidad
10.
J Org Chem ; 82(14): 7280-7286, 2017 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-28696696

RESUMEN

An efficient approach for the synthesis of benzo-fused pyridoindolone derivatives via a one-pot copper catalyzed tandem reaction of 2-iodobenzamides with 2-iodobenzylcyanides has been developed. Using this protocol, benzo-fused pyridoindolone derivatives are obtained in high yields in a relatively short period of time under mild reaction conditions. To the best of our knowledge, this is the first approach where one can synthesize free indole N-H benzo-fused pyridoindolones. Also, both indole and pyridone cores are constructed during the course of the reaction. The methodology shows good functional group tolerance and allows synthesis of thiophene-fused pyridoindolones and fused indolobenzonaphthyridone derivatives.

11.
Opt Express ; 24(15): 16815-21, 2016 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-27464134

RESUMEN

Planar photonics using metasurfaces is of great interest because a metasurface can control the flow of light beyond that attainable with natural materials. The resonance wavelength of a binary-grating metasurface is adjustable by changing the width and thickness of the nanostructure. We propose a novel combination of nematic liquid crystals and a binary-grating metasurface with which the diffraction efficiency can be controlled by adjusting the applied voltage.

12.
Nanoscale ; 5(3): 1018-25, 2013 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-23249951

RESUMEN

Herein, we describe a simple fabrication procedure for creating artificial hierarchical micro/nanopillars on silicon substrates that allows an effective, precise control of the interfacial adhesion and surface hydrophobicity. These well-defined hierarchical micro/nanostructures have four possible wetting states: Cassie-Cassie (C-C), Cassie-Wenzel (C-W), Wenzel-Cassie (W-C) and Wenzel-Wenzel (W-W). By controlling the critical height of the micro/nanopillars, it is possible to fabricate hierarchical micro/nanostructures in these four states. Thus, the hierarchical superhydrophobic surfaces proposed and fabricated in this study are promising for mimicking either lotus leaves with low adhesion or rose petals with high adhesion.


Asunto(s)
Cristalización/métodos , Modelos Químicos , Modelos Moleculares , Nanoestructuras/química , Nanoestructuras/ultraestructura , Adhesividad , Simulación por Computador , Sustancias Macromoleculares/química , Conformación Molecular , Tamaño de la Partícula , Propiedades de Superficie
13.
Small ; 7(20): 2906-13, 2011 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-21861294

RESUMEN

The formation of focal adhesions on various sizes of fibronectin patterns, ranging from 200 µm to 250 nm, was systematically investigated by total internal reflection fluorescence microscopy and super-resolution imaging. It was found that cells adhered to and spread on these micro/nanopatterns, forming focal adhesions. On a micrometer scale the shape of the focal adhesions was elongated. However, on the nanometer scale, the shape of focal adhesions became dotlike. To further explore the distribution of focal adhesion proteins formed on surfaces, a localization-based super-resolution imaging technique was employed in order to determine the position and density of vinculin proteins. A characteristic distance of 50 nm was found between vinculin molecules in the focal adhesions, which did not depend on the size of the fibronectin nanopatterns. This distance was found to be crucial for the formation of focal adhesions. In addition, the density of vinculin at the focal adhesions formed on the nanopatterns increased as the pattern size decreased. The density of the protein was found to be 425 ± 247, 584 ± 302, and 703 ± 305 proteins µm(-2) on the 600, 400, and 250 nm fibronectin patterns respectively. Whereas 226 ± 77 proteins µm(-2) was measured for the matured focal adhesions on homogeneous fibronectin coated substrates. The increase in vinculin density implies that an increase in mechanical load was applied to the focal adhesions formed on the smaller nanopatterns.


Asunto(s)
Diagnóstico por Imagen/métodos , Adhesiones Focales/metabolismo , Nanotecnología/métodos , Animales , Células CHO , Adhesión Celular/fisiología , Cricetinae , Fibronectinas/química , Adhesiones Focales/química
14.
Nanotechnology ; 22(26): 265302, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21576808

RESUMEN

Here we describe a simple approach to create various sizes of protein nanoarrays for the investigation of cell adhesion. Using a combination of nanosphere lithography, oxygen plasma treatment, deep etching and nanomolding processes, well-ordered polymeric nanopillar arrays have been fabricated with diameters in the range of 50-600 nm. These nanopillar arrays were used as stamps for nanocontact printing to create fibronectin nanoarrays, which were used to study the size dependent formation of focal adhesion. It was found that cells can adhere and spread on fibronectin nanoarrays with a fibronectin pattern as small as 50 nm. It was also found that the average size of focal adhesion decreased as the size of the fibronectin pattern was reduced.


Asunto(s)
Fibronectinas/química , Adhesiones Focales/metabolismo , Nanoestructuras/química , Nanotecnología/métodos , Tamaño de la Partícula , Polímeros/química , Análisis por Matrices de Proteínas/métodos , Animales , Células CHO , Cricetinae , Cricetulus , Fluoresceína-5-Isotiocianato/metabolismo , Microscopía de Fuerza Atómica , Microscopía Fluorescente , Nanoestructuras/ultraestructura , Silicio/química
15.
Langmuir ; 24(17): 9889-97, 2008 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-18683962

RESUMEN

To clarify a driving mechanism for the self-movement of a droplet across hydrophobic textured surfaces in series and to develop applications for a microfluidic device, we report a theoretical model, a microfabrication technique, and experimental measurements. The contact angle of a droplet on a composite surface, the stable surface energy level, and the energy barrier caused by hysteresis were investigated. With increasing patterned density of the microstructure, the contact angle and stable surface energy decreased gradually, but the energy barrier increased. Both the analytical results and the experimental measurements show that the surface energy for a suspended status is greater than that for a collapsed status, which produces increased energy to generate the movement of a droplet. An analysis of interactions between actuation force, resistive force, and viscous force during the motion of a droplet is based on the equilibrium between forces. From the perspective of energy conversion, the difference in surface energy between a higher state and a lower state would drive a single droplet and make it move spontaneously if it could overcome the static friction force resulting from hysteresis and the kinetic friction force under droplet movement. The mean velocity in the present device, measured to be 62.5 mm s (-1), agrees satisfactorily with the theoretical prediction. The model developed for the energy levels enables us to assess the contact mode of a droplet placed on the patterned surface. For a prediction of the transport capability of the designed devices, a theoretical interpretation of the conversion between the surface energy and the kinetic energy of the droplet establishes a criterion that the pattern density of a textured surface should be less than 0.76. The effective rate of energy conversion is estimated to be 20.6%.


Asunto(s)
Técnicas Analíticas Microfluídicas , Química Física/métodos , Diseño de Equipo , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Microfluídica , Modelos Estadísticos , Modelos Teóricos , Propiedades de Superficie , Termodinámica , Humectabilidad
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