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1.
Emerg Infect Dis ; 25(4): 814-816, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30882327

RESUMEN

A serosurvey of 600 workers newly arrived in Taiwan from 4 Southeast Asia countries showed that 18 (3%) were positive for Zika virus IgM; 6 (1%) fulfilled the World Health Organization criteria for laboratory-confirmed recent Zika virus infection. The incidence of Zika virus infection in Southeast Asia might be underestimated.


Asunto(s)
Anticuerpos Antivirales/inmunología , Virus del Dengue/inmunología , Dengue/epidemiología , Dengue/inmunología , Migrantes , Infección por el Virus Zika/epidemiología , Infección por el Virus Zika/inmunología , Virus Zika/inmunología , Anticuerpos Neutralizantes/inmunología , Dengue/historia , Dengue/virología , Historia del Siglo XXI , Humanos , Inmunoglobulina G , Pruebas de Neutralización , Estudios Seroepidemiológicos , Taiwán/epidemiología , Infección por el Virus Zika/historia , Infección por el Virus Zika/virología
2.
Opt Express ; 24(16): 17541-52, 2016 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-27505725

RESUMEN

Photoresist and electron beam lithography techniques were used to fabricate embedded Ag bowtie and diabolo nanostructures with various apex angles on the surface of a TiO2 film. The reinforced localized surface plasmon resonance (LSPR) and electric field generated at both the Ag/TiO2 and air/TiO2 interfaces enabled high light absorbance in the TiO2 nanostructure. Results for both the bowtie and diabolo nanostructures showed that a reduction in the apex angle enhances both LSPR and Raman intensity. The maximum electric current density observed at the apex indicates that the strongest SPR confines at the tip gap of the bowtie and corners of the diabolo. In a long-wavelength region, as the apex angle increases, the resonant peak wavelength of the standing wave matches the increased length of the prism edges of the bowtie and diabolo to create a redshift. In a short-wavelength region, as the apex angle increases, the blueshift of the resonant peak wavelength is presumably attributable to the increase in the effective index of the local surface plasmon polariton standing wave mainly residing along both the bowtie and diabolo axes. The redshift and blueshift trend in the simulation results for the resonant peak wavelength agrees well with the experimental results. The fastest photocatalytic rate was obtained by placing the Ag/TiO2 bowtie at an apex angle of 30° in the methylene blue solution, revealing that the plasmonic photocatalysis causes the highest degradation efficiency. This is because the Schottky junction and LSPR can stimulate many valid radicals for the environmental improvement.

3.
Disabil Rehabil ; 44(10): 2099-2103, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-32903114

RESUMEN

OBJECTIVE: To compare the test-retest reliability and random measurement errors of the Barthel Index (BI) and modified Barthel Index (MBI) in patients with chronic stroke. METHOD: The intraclass correlation coefficient (ICC) and the minimal detectable change (MDC) were applied respectively to examine the test-retest reliability (about 2 weeks apart) and the random measurement errors. The MDC% was used to adjust the cut-off score for determining whether a real change had been achieved, if heteroscedasticity existed. RESULTS: A total of 60 patients participated. The BI and MBI both had high ICCs (0.94 and 0.94, respectively) with small MDCs (16.2 and 15.4, respectively) and MDC%s (21.2% and 19.0%, respectively), indicating that both measures have comparable reliability in repeated assessments. However, moderate associations (r = -0.47 for the BI and -0.59 for the MBI) were found between the means of tests and retests and the absolute values of change scores, indicating heteroscedasticity. These findings suggest that a fixed MDC value is not appropriate for determining the real change in both measures because the amount of random measurement error varies with the patients' ADL function. CONCLUSION: The MBI, which showed excellent test-retest reliability and relatively lower random measurement error than the BI, appears to be a better ADL measure. The MDC% adjusted value is recommended to determine whether the change scores are beyond random measurement error.IMPLICATIONS FOR REHABILITATIONThe MBI is recommended for clinical and research applications because it has better test-retest reliability and relatively lower random measurement error than those of the original BI.The MDC% adjusted value is recommended to determine whether the change scores are beyond random measurement error when the MBI or the BI is used.


Asunto(s)
Accidente Cerebrovascular , Humanos , Reproducibilidad de los Resultados
4.
Langmuir ; 27(1): 240-9, 2011 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-21141947

RESUMEN

The lateral displacement of cells orthogonal to a flow stream by rolling on asymmetrical receptor patterns presents a new opportunity for the label-free separation and analysis of cells. Understanding the nature of cell rolling trajectories on such substrates is necessary to the engineering of substrates and the design of devices for cell separation and analysis. Here, we investigate the statistical nature of cell rolling and the effect of pattern geometry and flow shear stress on cell rolling trajectories using micrometer-scale patterns of biomolecular receptors with well-defined edges. Leukemic myeloid HL60 cells expressing the PSGL-1 ligand were allowed to flow across a field of patterned lines fabricated using microcontact printing and functionalized with the P-selectin receptor, leveraging both the specific adhesion of this ligand-receptor pair and the asymmetry of the receptor pattern inclination angle with respect to the fluid shear flow direction (α = 5, 10, 15, and 20°). The effects of the fluid shear stress magnitude (τ = 0.5, 1, 1.5, and 2.0 dyn/cm(2)), α, and P-selectin incubation concentration were quantified in terms of the rolling velocity and edge tracking length. Rolling cells tracked along the inclined edges of the patterned lines before detaching and reattaching on another line. The detachment of rolling cells after tracking along the edge was consistent with a Poisson process of history-independent interactions. Increasing the edge inclination angle decreased the edge tracking length in an exponential manner, contrary to the shear stress magnitude and P-selectin incubation concentration, which did not have a significant effect. On the basis of these experimental data, we constructed an empirical model that predicted the occurrence of the maximum lateral displacement at an edge angle of 7.5°. We also used these findings to construct a Monte Carlo simulation for the prediction of rolling trajectories of HL60 cells on P-selectin-patterned substrates with a specified edge inclination angle. The prediction of lateral displacement in the range of 200 µm within a 1 cm separation length supports the feasibility of label-free cell separation via asymmetric receptor patterns in microfluidic devices.


Asunto(s)
Movimiento Celular , Selectina-P/metabolismo , Rastreo Celular , Células HL-60 , Humanos , Microtecnología , Distribución de Poisson , Polietilenglicoles/química , Estrés Mecánico
5.
World J Surg ; 34(10): 2383-8, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20512491

RESUMEN

OBJECTIVES: The aim of this study was to identify the preoperative factors that affect the survival of patients who undergo esophagogastrectomy after corrosive ingestion, using analysis of their physiological condition, associated diseases, physical examination, and laboratory data. METHODS: Between January 1995 and December 2005, 71 consecutive patients who underwent esophagogastrectomy for corrosive ingestion injuries were retrospectively reviewed. Of them, 41 survived and 30 (42.3%) died during the perioperative period. Logistic regression analyses were used to model markers for postoperative mortality, including descriptive data, clinical symptoms/signs, and laboratory data. RESULTS: There were 35 males and 36 females included in the study, with an average age of 54.7 +/- 14.9 years. After adjustments in the logistic regression model, age of over 65 years (p = 0.021), presence of gross hematuria (p = 0.016), twofold level of serum AST (p = 0.012), blood pH level below 7.2 (p = 0.017), and deficit of blood base over 16 (p = 0.007) were found to be independent risk factors for patient mortality. CONCLUSIONS: We consider age over 65 years, preoperative pH < 7.2, base deficit >16, twofold level of serum AST, and presence of gross hematuria to be the important factors predicting postoperative hospital mortality in patients presenting with corrosive ingestion injuries who require emergency surgery.


Asunto(s)
Cáusticos/efectos adversos , Esofagectomía/mortalidad , Gastrectomía/mortalidad , Tracto Gastrointestinal/lesiones , Tracto Gastrointestinal/cirugía , Mortalidad Hospitalaria , Enfermedad Aguda , Adulto , Anciano , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Estudios Retrospectivos
6.
World J Surg ; 34(8): 1832-9, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20414775

RESUMEN

BACKGROUND: The prognosis and quality of life (QOL) for those with cervical esophageal cancer is extremely poor, and chemoradiotherapy remains the mainstay treatment. During the past few years, our surgical teams has implemented a more aggressive and radical resection: total laryngopharyngectomy with neck dissection, total esophagectomy, and reconstruction with stomach. This study compares the results of chemoradiotherapy and that of the aforementioned surgical approach. METHODS: This is a retrospective study of 15 patients who underwent radical resection and 14 patients who received chemoradiation. Their age, sex, tumor stage and grade, pre- and posttreatment dysphagia scores, operating time, blood loss, length of intensive care and postoperative stay, days to resume oral intake, complications, Eastern Cooperative Oncology Group (ECOG) status, QOL score, and disease-specific survival were recorded and compared. RESULTS: There were no significant differences in age, sex, pretreatment dysphagia score, cancer stage and grade, ECOG status (posttreatment), associate diseases, preoperative QOL, or follow-up period between the two groups. However, the posttreatment dysphagia score was significantly better for the operative group (P < 0.001). QOL improved in both groups, and the operative group seemed better although the difference was not significant. In addition, the survival between the two groups was statistically insignificant (P = 0.97, log-rank test). CONCLUSIONS: Our experience showed that radical surgery that includes total laryngopharyngectomy with neck dissection, total esophagectomy, and reconstruction with stomach for cervical esophageal cancer is beneficial to patients in terms of better eating.


Asunto(s)
Carcinoma de Células Escamosas/cirugía , Neoplasias Esofágicas/cirugía , Adulto , Anciano , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/radioterapia , Distribución de Chi-Cuadrado , Terapia Combinada , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/radioterapia , Esofagectomía , Femenino , Humanos , Laringectomía , Masculino , Persona de Mediana Edad , Disección del Cuello , Estadificación de Neoplasias , Complicaciones Posoperatorias , Pronóstico , Calidad de Vida , Procedimientos de Cirugía Plástica , Estudios Retrospectivos , Estadísticas no Paramétricas , Estómago/trasplante , Toracotomía , Traqueostomía , Resultado del Tratamiento
7.
J Educ Health Promot ; 9: 326, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33426130

RESUMEN

BACKGROUND: Undergraduate dental students have to do multiple tasks as part of their extensive curriculum in order to achieve the proficiencies expected of them. During the course of their study, a tendency to procrastinate and question their self-efficacy is detrimental for the students. The aim of this study was to evaluate the level of procrastination and self-efficacy and its related factors among dental undergraduate students. SUBJECTS AND METHODS: This cross-sectional study was conducted among all (n = 361) consented dental undergraduate students of our dental school. A twenty-item Lay's Procrastination Scale for student population and a ten-item General Self-Efficacy Scale were used for the study after getting institutional ethical approval. The quantitative data were explained using descriptive statistics. Independent sample t-test and ANOVA were used to determine the association between self-efficacy, academic procrastination, and genders and academic years. Pearson correlation coefficient was used to determine the association between self-efficacy and procrastination. Multiple linear regression analysis was performed to determine the related factors to academic procrastination. RESULTS: High procrastination (score ≥62) was seen among 28.5% of students. The mean self-efficacy score was 29.5. There was no significant difference between genders for procrastination scores (P = 0.835) and between academic years (P = 0.226). Males showed significantly more self-efficacy (P < 0.001), and self-efficacy did not show any significant difference (P = 0.204) between academic years though a tendency for year 5 students to have lower self-efficacy scores was observed. Academic procrastination was negatively correlated with self-efficacy (r = -0.238 and P < 0.001). CONCLUSIONS: For dental undergraduates who have cognitive load as well as work associated with patients, procrastination and self-efficacy are negatively correlated.

8.
Lab Chip ; 9(3): 411-6, 2009 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-19156290

RESUMEN

A novel high-strength nano-adhesive is demonstrated for fabricating nano- and microfluidic devices. While the traditional plasma sealing methods are specific for sealing glass to poly(dimethylsiloxane) (PDMS), the new method is compatible with a wide variety of polymeric and inorganic materials, including flexible substrates. Additionally, the traditional method requires that sealing occur within minutes after the plasma treatment. In contrast, the individual parts treated with the nano-adhesive could be aged for at least three months prior to joining with no measurable deterioration of post-cure adhesive strength. The nano-adhesive is comprised of a complementary pair of polymeric nanolayers. An epoxy-containing polymer, poly(glycidyl methacrylate) (PGMA) was grown via initiated chemical vapor deposition (iCVD) on the substrate containing the channels. A plasma polymerized polyallylamine (PAAm) layer was grown on the opposing flat surface. Both CVD monomers are commercially available. The PGMA nano-adhesive layer displayed conformal coverage over the channels and was firmly tethered to the substrate. Contacting the complementary PGMA and PAAm surfaces, followed by curing at 70 degrees C, resulted in nano- and micro-channel structures. The formation of the covalent tethers between the complementary surfaces produces no gaseous by-products which would need to outgas. The nano-adhesive layers did not flow significantly as a result of curing, allowing the cross-sectional profile of the channel to be maintained. This enabled fabrication of channels with widths as small as 200 nm. Seals able to withstand > 50 psia were fabricated employing many types of substrates, including silicon wafer, glass, quartz, PDMS, polystyrene petri dishes, poly(ethylene terephthalate) (PET), polycarbonate (PC), and poly(tetrafluoro ethylene) (PTFE).


Asunto(s)
Adhesivos/química , Gases/química , Técnicas Analíticas Microfluídicas/métodos , Nanotecnología/métodos , Adhesividad , Fenómenos Mecánicos , Técnicas Analíticas Microfluídicas/instrumentación , Microscopía Electrónica de Rastreo , Poliaminas/química , Ácidos Polimetacrílicos/química , Silanos/química
9.
Nanotechnology ; 20(30): 305201, 2009 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-19581691

RESUMEN

Low-temperature (approximately 150 degrees C), atomic-layer-deposited Al(2)O(3) films on nanoporous TiO2 electrodes of dye-sensitized solar cells (DSSCs) were investigated using electron spectroscopy. The power conversion efficiency (PCE) of the DSSCs was increased from 5.7% to 6.5%, an improvement of 14%, with one monolayer of Al(2)O(3) with a thickness of approximately 0.2 nm. The formation of Ti-O-Al(OH)(2) and interfacial dipole layers exhibited a strong influence on the work function of the Al(2)O(3) over-layers, while the thicker Al(2)O(3) over-layers caused the values of valence band maximum and band gap to approach the values associated with pure Al(2)O(3). A work function difference (Delta Phi(A-T)) of 0.4 eV and a recombination barrier height (epsilon(RB)) of 0.1 eV were associated with the highest PCE achieved by the first monolayer of the Al(2)O(3) layer. Thicker Al(2)O(3) over-layers, however, caused significant reduction of PCE with negative Delta Phi(T-A) and increased interfacial energy barrier height ((*)epsilon(IB)) between the N719 dyes and TiO2 electrodes. It was concluded that the PCE of the DSSCs may correlate with Delta Phi(A-T), epsilon(RB), and (*)epsilon(IB) resulting from various thicknesses of the Al(2)O(3) over-layers and that interfacial reactions, such as the formation of Ti-O-Al(OH)(2) and dipole layers, play an important role in determining the interfacial energy levels required to achieve optimal performance of dye-sensitized TiO2 solar cells.

10.
Hepatogastroenterology ; 56(91-92): 707-10, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19621686

RESUMEN

BACKGROUND/AIMS: Transthoracic and transhiatal esophagectomy are two common procedures for esophageal cancer resection. Prospective studies comparing the two methods in Asian people are few. In addition, the data comparing their effects on the quality of life are lacking. METHODOLOGY: A prospective randomized study was conducted from January 2003. Patients of resectable esophageal cancer of comparable stage were allocated to undergo the transthoracic or transhiatal procedure in turn. They were all reconstructed with stomach interposition through the retrosternal route. Discharged patients were followed-up in the outpatient clinic. They were questioned on the topics of (i) severity of pain, (ii) ease of swallowing, (iii) satisfaction of daily activities, (iv) dependence on medications, (v) working ability, (vi) fatigue, (vii) appetite, (viii) sociality, (ix) happiness and (x) self respect, in the third, sixth and twelfth month. Also the demographic data, operative results and survival were recorded. RESULTS: Up to December 2006, eighty-seven patients of stage II and III, including 71 patients of middle third lesions and 16 lower third lesions were enrolled. The operation time was significantly longer, and the leakage rate was higher in the transthoracic group (Student's t-test and Fischer's exact test, respectively). However, intraoperative blood loss and postoperative hospital stay were not significantly different (Student t-test). Also, the Kaplan-Meier survival curves of these two groups were not significantly different by log-rank test (p=0.286). The score on the quality of life of transhiatal patients was significantly higher than that of transthoracic patients in the third, sixth and twelfth month. CONCLUSIONS: Transhiatal esophagectomy is a safe and fast procedure. The survival was similar to that of transthoracic approach. Its leakage rate was lower and quality of life was better.


Asunto(s)
Pueblo Asiatico , Carcinoma/etnología , Carcinoma/cirugía , Neoplasias Esofágicas/etnología , Neoplasias Esofágicas/cirugía , Esofagectomía/métodos , Adulto , Anciano , Carcinoma/mortalidad , Estudios de Cohortes , Neoplasias Esofágicas/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Satisfacción del Paciente , Calidad de Vida , Recuperación de la Función , Tasa de Supervivencia , Resultado del Tratamiento
12.
Eur J Med Chem ; 89: 320-30, 2015 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-25462248

RESUMEN

This study describes the development of a series of 1-arylsulfonyl-6-(N-hydroxyacrylamide)tetrahydroquinolines, potent histone deacetylase (HDAC) inhibitors which are cytotoxic to PC-3 cells. (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide (11) exhibits marked anti-HDAC and antiproliferative activity, and is slightly more effective than N(1)-hydroxy-N(8)-phenyloctanediamide (SAHA, Vorinostat, 1). In a xenograft tumor model, 11, at doses of 100 or 200 mg/kg orally, suppresses the growth of PC-3 cells and leads to tumor growth inhibition of 38.8% and 57.9%, respectively. Compound 11 is a lead compound for further development of potential prostate cancer inhibitors.


Asunto(s)
Antineoplásicos/síntesis química , Proliferación Celular/efectos de los fármacos , Inhibidores de Histona Desacetilasas/síntesis química , Neoplasias de la Próstata , Quinolonas/síntesis química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Línea Celular Tumoral , Inhibidores de Histona Desacetilasas/química , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Histona Desacetilasas/metabolismo , Humanos , Masculino , Ratones Desnudos , Estructura Molecular , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/enzimología , Neoplasias de la Próstata/patología , Quinolonas/química , Quinolonas/farmacología , Quinolonas/uso terapéutico , Ensayos Antitumor por Modelo de Xenoinjerto
13.
Sci Rep ; 3: 2329, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23900203

RESUMEN

Flow fractionation of cells using physical fields to achieve lateral displacement finds wide applications, but its extension to surface molecule-specific separation requires labeling. Here we demonstrate affinity flow fractionation (AFF) where weak, short-range interactions with asymmetric molecular patterns laterally displace cells in a continuous, label-free process. We show that AFF can directly draw neutrophils out of a continuously flowing stream of blood with an unprecedented 400,000-fold depletion of red blood cells, with the sorted cells being highly viable, unactivated, and functionally intact. The lack of background erythrocytes enabled the use of AFF for direct enumeration of neutrophils by a downstream detector, which could distinguish the activation state of neutrophils in blood. The compatibility of AFF with capillary microfluidics and its ability to directly separate cells with high purity and minimal sample preparation will facilitate the design of simple and portable devices for point-of-care diagnostics and quick, cost-effective laboratory analysis.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Fraccionamiento Celular/métodos , Citometría de Flujo/métodos , Microfluídica/métodos , Neutrófilos/citología , Neutrófilos/fisiología , Células Cultivadas , Humanos
14.
Nanoscale Res Lett ; 7(1): 688, 2012 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-23272760

RESUMEN

Photoelectrodes for dye-sensitized solar cells were fabricated using commercially available zinc oxide (ZnO) nanoparticles and sensitized with the dye N719. This study systematically investigates the effects of two fabrication factors: the ZnO film thickness and the dye adsorption time. Results show that these two fabrication factors must be optimized simultaneously to obtain efficient ZnO/N719-based cells. Different film thicknesses require different dye adsorption times for optimal cell performance. This is because a prolonged dye adsorption time leads to a significant deterioration in cell performance. This is contrary to what is normally observed for titanium dioxide-based cells. The highest overall power conversion efficiency obtained in this study was 5.61%, which was achieved by 26-µm-thick photoelectrodes sensitized in a dye solution for 2 h. In addition, the best-performing cell demonstrated remarkable at-rest stability despite the use of a liquid electrolyte. Approximately 70% of the initial efficiency remained after more than 1 year of room-temperature storage in the dark. To better understand how dye adsorption time affects electron transport properties, this study also investigated cells based on 26-µm-thick films using electrochemical impedance spectroscopy (EIS). The EIS results show good agreement with the measured device performance parameters.

15.
Nanoscale Res Lett ; 7(1): 166, 2012 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-22390565

RESUMEN

A low-temperature, direct blending procedure was used to prepare composite films consisting of zinc oxide [ZnO] nanoparticles and multiwalled carbon nanotubes [MWNTs]. The mesoporous ZnO/MWNT films were fabricated into the working electrodes of dye-sensitized solar cells [DSSCs]. The pristine MWNTs were modified by an air oxidation or a mixed acid oxidation treatment before use. The mixed acid treatment resulted in the disentanglement of MWNTs and facilitated the dispersion of MWNTs in the ZnO matrix. The effects of surface property and loading of MWNTs on DSSC performance were investigated. The performance of DSSCs was found to depend greatly on the type and the amount of MWNTs incorporated. At a loading of 0.01 wt%, the acid-treated MWNTs were able to increase the power conversion efficiency of fabricated cells from 2.11% (without MWNTs) to 2.70%.

16.
J Vis Exp ; (48)2011 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-21372779

RESUMEN

Lateral displacement of cells orthogonal to a flow stream by rolling on asymmetric receptor patterns presents an opportunity for development of new devices for label-free separation and analysis of cells. Such devices may use lateral displacement for continuous-flow separation, or receptor patterns that modulate adhesion to distinguish between different cell phenotypes or levels of receptor expression. Understanding the nature of cell rolling trajectories on receptor-patterned substrates is necessary for engineering of the substrates and design of such devices. Here, we demonstrate a protocol for studying cell rolling trajectories on asymmetric receptor patterns that support cell rolling adhesion. Well-defined, µm-scale patterns of P-selectin receptors were fabricated using microcontact printing on gold-coated slides that were incorporated in a flow chamber. HL60 cells expressing the PSGL-1 ligand were flowed across a field of patterned lines and visualized on an inverted bright field microscope. The cells rolled and tracked along the inclined edges of the patterns, resulting in lateral deflection. Each cell typically rolled for a certain distance along the pattern edges (defined as the edge tracking length), detached from the edge, and reattached to a downstream pattern. Although this detachment makes it difficult to track the entire trajectory of a cell from entrance to exit in the flow chamber, particle-tracking software was used to analyze and yield the rolling trajectories of the cells during the time when they were moving on a single receptor-patterned line. The trajectories were then examined to obtain distributions of cell rolling velocities and the edge tracking lengths for each cell for different patterns. This protocol is useful for quantifying cell rolling trajectories on receptor patterns and relating these to engineering parameters such as pattern angle and shear stress. Such data will be useful for design of microfluidic devices for label-free cell separation and analysis.


Asunto(s)
Movimiento Celular/fisiología , Técnicas Citológicas/métodos , Adhesión Celular/fisiología , Técnicas Citológicas/instrumentación , Células HL-60 , Humanos , Glicoproteínas de Membrana/biosíntesis , Microscopía/métodos , Selectina-P/química , Polietilenglicoles/química
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