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1.
Mult Scler J Exp Transl Clin ; 10(2): 20552173241255008, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38817553

RESUMEN

Background: Eye movements can reflect brain alterations and inform on the presence of motor disabilities and cognitive impairments in people with multiple sclerosis (pwMS). Objective: The aim of the study was to determine the correlation between motor and cognitive measurements and eye movement parameters when performing the n-back task (NBKT). Methods: This was a cross-sectional study carried out at Ramos Mejía Hospital, a center specialized in demyelinating diseases in Buenos Aires, Argentina. The study population consisted of 66 patients with relapsing-remitting multiple sclerosis (RRMS) and 5 patients with secondary progressive multiple sclerosis (SPMS). pwMS performed the n-back test while using a device head mounted display (HMD) with eyetracking capabilities in order to capture eye movement. Clinical motor and cognitive measures were assessed with Expanded Disability Status Scale (EDSS), Nine Hole Peg Test (NHPT), Timed 25-Foot Walk (T25FW), and Symbol Digit Modalities Test (SDMT). Results: pwMS showed strong and statistically significant correlations between gaze duration; number of fixations, saccade amplitude and motor disabilities and cognitive impairments as measured by EDSS, NHPT, T25FW, and SDMT. Conclusion: This study found significant correlations between eye movement behavior and motor and cognitive disability in pwMS. These findings suggest that eye movements have the potential to be used as a surrogate biomarker in MS progression.

2.
Scand J Prim Health Care ; 28(4): 242-8, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20873973

RESUMEN

OBJECTIVE: To analyse the 10-year performance of the original Framingham coronary risk function and of the SCORE cardiovascular death risk function in a non-diabetic population of 40-65 years of age served by a Spanish healthcare centre. Also, to estimate the percentage of patients who are candidates for antihypertensive and lipid-lowering therapy. DESIGN: Longitudinal, observational study of a retrospective cohort followed up for 10 years. SETTING: Primary care health centre. PATIENTS: A total of 608 non-diabetic patients of 40-65 years of age (mean 52.8 years, 56.7% women), without evidence of cardiovascular disease were studied. MAIN OUTCOME MEASURES: Coronary risk at 10 years from the time of their recruitment, using the tables based on the original Framingham function, and of their 10-year risk of fatal cardiovascular disease using the SCORE tables. RESULTS: The actual incidence rates of coronary and fatal cardiovascular events were 7.9% and 1.5%, respectively. The original Framingham equation over-predicted risk by 64%, while SCORE function over-predicted risk by 40%, but the SCORE model performed better than the Framingham one for discrimination and calibration statistics. The original Framingham function classified 18.3% of the population as high risk and SCORE 9.2%. The proportions of patients who would be candidates for lipid-lowering therapy were 31.0% and 23.8% according to the original Framingham and SCORE functions, respectively, and 36.8% and 31.2% for antihypertensive therapy. CONCLUSION: The SCORE function showed better values than the original Framingham function for each of the discrimination and calibration statistics. The original Framingham function selected a greater percentage of candidates for antihypertensive and lipid-lowering therapy.


Asunto(s)
Enfermedades Cardiovasculares/diagnóstico , Adulto , Anciano , Antihipertensivos/uso terapéutico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/prevención & control , Centros Comunitarios de Salud , Femenino , Estudios de Seguimiento , Humanos , Hipolipemiantes/uso terapéutico , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , España/epidemiología
3.
Front Chem ; 8: 507887, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33102442

RESUMEN

Flavonoids are one of the main groups of polyphenols found in natural products. Traditional flavonoid extraction techniques are being replaced by advanced techniques to reduce energy and solvent consumption, increase efficiency and selectivity, to meet increased market demand and environmental regulations. Advanced technologies, such as microwaves, ultrasound, pressurized liquids, supercritical fluids, and electric fields, are alternatives currently being used. These modern techniques are generally faster, more environmentally friendly, and with higher automation levels compared to conventional extraction techniques. This review will discuss the different methods available for flavonoid extraction from natural sources and the main parameters involved (temperature, solvent, sample quantity, extraction time, among others). Recent trends and their industrial importance are also discussed in detail, providing insight into their potential. Thus, this paper seeks to review the innovations of compound extraction techniques, presenting in each of them their advantages and disadvantages, trying to offer a broader scope in the understanding of flavonoid extraction from different plant matrices.

4.
Food Chem ; 231: 1-10, 2017 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-28449984

RESUMEN

This work investigated the extraction efficiency of polyphenols (anthocyanins) from blackberry, blueberry and grumixama residues using combined ultrasonic assisted extraction (UAE) and pressurized liquid extraction (PLE) (UAE+PLE). The performance of UAE+PLE was compared to those achieved by the isolated PLE and UAE methods and conventional Soxhlet extraction. The effects of the extraction methods and solvents (acidified water pH 2.0, ethanol+water 50% v/v and ethanol+water 70% ethanol v/v) on total phenolics content, anthocyanin composition and antioxidant capacity of extracts were investigated by a full factorial design. The extraction efficiency for total phenolics and antioxidant capacity in decreasing order was: UAE+PLE>PLE≈Soxhlet>UAE, and for anthocyanins it was: Soxhlet≈UAE>UAE+PLE>PLE, using hydroethanolic mixtures as solvents. Extractions with acidified water and ultrasound were not effective to recover phenolics. Two, four and fourteen anthocyanins were identified in the extracts from grumixama, blackberry and blueberry, respectively.


Asunto(s)
Antocianinas , Eugenia , Rubus , Vaccinium myrtillus , Extractos Vegetales
5.
Ultrason Sonochem ; 31: 284-94, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26964951

RESUMEN

Extracts with bioactive compounds were obtained from the red pepper variety "dedo de moça" (Capsicum baccatum L. var. pendulum) through supercritical fluid extraction with carbon dioxide assisted by ultrasound (SFE-US). The process was tested at pressures of 15, 20 and 25 MPa; temperatures of 40, 50 and 60 °C, and ultrasonic powers of 200, 400 and 600 W applied during 40, 60 and 80 min of extraction. The CO2 mass flow rate was fixed at 1.7569 × 10(-4) kg/s. Global yield, phenolic content, antioxidant capacity and capsaicinoid concentration were evaluated in the extracts. The application of ultrasound raised the global extraction yield of SFE up to 45%. The phenolic content of the extract increased with the application of higher ultrasound power and radiation time. The capsaicinoid yield was also enhanced with ultrasound up to 12%. However, the antioxidant capacity did not increase with the ultrasound application. The BET-based model and the broken and intact cell model fitted well to the kinetic SFE curves. The BET-based model with three adjustable parameters resulted in the best fits to the experimental data. Field emission scanning electron microscopy (FESEM) images showed that SFE disturbed the vegetable matrix, releasing particles from the inner region of the plant cells to their surface. When the ultrasound was applied this effect was more pronounced. On the other hand, cracks, fissures or any sign of rupture were not identified on the sample surface.


Asunto(s)
Capsicum/química , Dióxido de Carbono/química , Cromatografía con Fluido Supercrítico/métodos , Fitoquímicos/aislamiento & purificación , Ultrasonido , Antioxidantes/análisis , Cinética , Microscopía Electrónica de Rastreo , Fenoles/análisis
6.
Food Chem ; 200: 167-74, 2016 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-26830575

RESUMEN

The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of a fast method for the analysis of main curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) present in extracts of turmeric (Curcuma longa L.). A step-by-step strategy was used to optimize temperature (40-55 °C), flow rate (1.0-2.5 mL min(-1)), mobile phase composition and equilibration time (1-5 min). A gradient method was developed using acidified water and acetonitrile combined with high column temperature (55 °C) and flow rate (2.5 mL min(-1)). Optimized conditions provided a method for the separation of these three curcuminoids in approximately 1.3 min with a total analysis time (sample-to-sample) of 7 min, including the clean-up and the re-equilibration of the column. Evaluation of chromatographic performance revealed excellent intraday and interday reproducibility (>99%), resolution (>2.23), selectivity (>1.12), peak symmetry (1.24-1.42) while presenting low limits of detection (<0.40 mg L(-1)) and quantification (<1.34 mg L(-1)). The robustness of the method was calculated according to the concentration/dilution of the sample and the injection volume. Several combinations of methanol and ethanol with water as sample solvents were evaluated and the best chromatographic results and extraction rate were obtained using 100% methanol. Finally, the developed method was validated with different extracts of turmeric rhizome and products that use turmeric in their formulation.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Curcuma/química , Extractos Vegetales/química
8.
J Agric Food Chem ; 63(4): 1107-1115, 2015 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-25572452

RESUMEN

Melatonin provides a number of benefits for human health. The study reported here concerns the optimization, validation, and application of analytical pressurized liquid extraction and high-performance liquid chromatography coupled to a fluorescence detector for the determination of melatonin in rice grains. The factors that are most likely to affect the extraction efficiency were optimized with a 2IV7-2 fractional factorial design. The optimum extraction conditions were achieved by applying 70% EtOAc in MeOH at 200 °C and 200 atm for a static time of 5 min in two cycles with 50% flushing and a 60 s purge to extract a 2.5 g rice sample. The method validation ensured excellent linearity, limit of detection, limit of quantification, precision, and recovery. Furthermore, the method was applied to various rice products composed of polished, whole grain, aromatic, black, black glutinous, red, and parboiled rice. All kinds of pigmented rice grains showed high levels of melatonin (>100 µg kg -1), and the highest levels were found in red rice.

9.
J Org Chem ; 69(10): 3413-6, 2004 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-15132550

RESUMEN

Direct reaction between quinone bisacetals and arylhydrazines gives azobenzenes. The presence of catalytic amounts of cerium ammonium nitrate strongly accelerates the reaction. When the bisacetal has a substituent at the 2,5-cyclohexadiene framework, only one regioisomer is formed. The method represents a simple, mild, and novel synthetic access to differently substituted azocompounds in high to excellent yield.

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