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1.
Molecules ; 26(13)2021 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-34206325

RESUMEN

In the present work, the optimization of the extraction of antioxidant compounds from apple pomace using ultrasound technology as an environmentally friendly and intensification process was developed. Different sonication powers, extraction temperatures and extraction times were studied and their influence on extraction yield and characteristics of the extracted samples (total phenolic compounds, flavonoid content and antioxidant capacity) are presented. The elaborated experimental design and the analysis of Pareto and response surface diagrams allowed us to determine the optimal extraction conditions. The conditions that allow the maximum extraction of phenolic compounds were found at 20 min, 90 °C and 50% ultrasound amplitude. Nevertheless, at these conditions, the antioxidant capacity measured by DPPH decreased in the extracted samples.


Asunto(s)
Antioxidantes , Frutas/química , Malus/química , Fitoquímicos , Extractos Vegetales/química , Sonicación , Antioxidantes/química , Antioxidantes/aislamiento & purificación , Fitoquímicos/química , Fitoquímicos/aislamiento & purificación
2.
PLoS Comput Biol ; 15(6): e1006903, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-31185008

RESUMEN

Popular computational models of decision-making make specific assumptions about learning processes that may cause them to underfit observed behaviours. Here we suggest an alternative method using recurrent neural networks (RNNs) to generate a flexible family of models that have sufficient capacity to represent the complex learning and decision- making strategies used by humans. In this approach, an RNN is trained to predict the next action that a subject will take in a decision-making task and, in this way, learns to imitate the processes underlying subjects' choices and their learning abilities. We demonstrate the benefits of this approach using a new dataset drawn from patients with either unipolar (n = 34) or bipolar (n = 33) depression and matched healthy controls (n = 34) making decisions on a two-armed bandit task. The results indicate that this new approach is better than baseline reinforcement-learning methods in terms of overall performance and its capacity to predict subjects' choices. We show that the model can be interpreted using off-policy simulations and thereby provides a novel clustering of subjects' learning processes-something that often eludes traditional approaches to modelling and behavioural analysis.


Asunto(s)
Simulación por Computador , Toma de Decisiones/fisiología , Aprendizaje/fisiología , Modelos Psicológicos , Adulto , Trastorno Bipolar/fisiopatología , Biología Computacional , Trastorno Depresivo/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Redes Neurales de la Computación , Adulto Joven
3.
Aust N Z J Psychiatry ; 54(10): 964-969, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32772708

RESUMEN

There has been a revolution in the use of mobile health devices for monitoring physical health. There is more recent interest in whether these devices can also be used for monitoring symptoms of mental illness. This paper considers how stress increases risk of mental deterioration and individuals with mental illness are sensitive to the effects of stress. It discusses how an inexpensive mobile health device could be used for detecting physiological signs of stress: deviations in biometrics such as sleep, activity and arousal may reflect a stress response and increased risk of relapse. These biometrics can allow patients to self-monitor and clinicians to detect early warning signs. This paper reviews the measurement of electrodermal activity, actigraphy and heart rate to predict mental deterioration. It considers the advantages of continuous measurement and reviews studies using mobile health devices to monitor stress and psychosis. It describes the potential for using a mobile health device to manage and monitor severe mental illness in young adults. Finally, this paper considers challenges associated with this approach, particularly with regard to correctly interpreting the physiological data and integrating the mobile health device into clinical practice. This paper concludes a mobile health device has the potential to enhance care by improving detection of early warning signs and increasing the connection between clinicians and their patients.


Asunto(s)
Trastornos Mentales , Trastornos Psicóticos , Telemedicina , Actigrafía , Computadoras de Mano , Humanos , Trastornos Mentales/diagnóstico , Trastornos Mentales/terapia , Adulto Joven
4.
Artif Organs ; 41(12): 1121-1126, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28568475

RESUMEN

Hemodialysis patients have a marked decrease in functional capacity when compared to healthy individuals. We evaluated the factors associated with functional capacity in hemodialysis patients. A total of 102 hemodialysis patients were evaluated. The patients were submitted to a 6-min walk test, peripheral muscle strength tests, and an evaluation of quality of life, anxiety, and depression. The laboratory data were measured. The 6-min walk test distance correlated significantly with age, educational level, hemoglobin, creatinine, number of comorbidities, peripheral muscle strength, and some domains of SF-36 quality of life questionnaire and depression (P < 0.05). Multiple linear regression showed that educational level, hemoglobin, peripheral muscle strength, and depression significantly affected the 6-min walk test distance (P < 0.05). The multiple correlation coefficient was 0.74, and the squared multiple correlation coefficient adjusted was 0.52. In conclusion, functional capacity was significantly associated with educational level, hemoglobin, peripheral muscle strength, and depression in hemodialysis patients.


Asunto(s)
Fuerza Muscular , Diálisis Renal , Adulto , Anciano , Ansiedad/complicaciones , Depresión/complicaciones , Prueba de Esfuerzo , Femenino , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino , Persona de Mediana Edad , Calidad de Vida , Diálisis Renal/efectos adversos , Encuestas y Cuestionarios , Caminata
5.
Plants (Basel) ; 12(22)2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-38005742

RESUMEN

Ditylenchus dipsaci is a plant-parasitic nematode with a great economic impact on bulbous crops, including garlic (Allium sativum L.), and is distributed worldwide, particularly in the Mediterranean region. Traditionally, garlic was a rainfed crop in Spain, but irrigated areas have increased during the last few decades. However, the expected climatic conditions, with longer and more intense droughts, will make it necessary to reduce the water supply to garlic crops. This poses the urgent need to select garlic cultivars more tolerant to water scarcity and that are also more resistant to plant pathogenic organisms. The aim of this work was to analyze the influence of water stress on the host response of garlic plants to D. dipsaci. The specific objectives were to evaluate the level of nematode infestation in plants from four garlic genotypes treated with a reduced irrigation regime and compare them with those of control plants not subjected to water stress. The observed results were correlated with changes in the bulb and root development, as well as in the physiological parameters (total chlorophyll concentration and proline accumulation). The effects were different depending on whether the plants were subjected to water stress before or after nematode inoculation, as well as whether the water stress was continuous or discontinuous. Garlic inter-cultivar variability also affected the obtained results.

6.
Int J Biol Macromol ; 247: 125855, 2023 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-37460069

RESUMEN

Bio-polyols, produced by liquefying lignin with polyhydric alcohols, offer a promising alternative to conventional polyols for polyurethane production. To enhance the sustainability on the production of these bio-polyols, this study proposes the use of crude glycerol and microwave-assisted liquefaction as substitutes for conventional methods and commercial glycerol. This approach reduces the energy requirements of the reaction while also adding value to this by-product. The synthesis of bio-polyols with suitable properties to produce elastic and rigid polyurethane was carried out using previously optimised reaction conditions. Organosolv lignins obtained from Eucalyptus globulus and Pinus radiata were employed, using polyethylene glycol and crude glycerol as solvents and sulphuric acid as a catalyst. Several parameters of the bio-polyols were analysed, including hydroxyl number (IOH), acid number (An), and functionality (f), suggesting that the bio-polyols were suitable for polyurethane synthesis. Bio-polyols formulated to produce rigid polyurethanes exhibited IOH values of 554 and 383 (mg KOH/g), An values of 1.91 and 4.21 (mg KOH/g), and functionalities of 4.16 and 3.14 for Eucalyptus globulus and Pinus radiata lignin. In the case of bio-polyols for elastic polyurethanes, the values were 228 and 173 (mg KOH/g) (IOH), 20.94 and 25.09 (mg KOH/g) (An), and functionalities of 3.51 and 2.08.


Asunto(s)
Glicerol , Lignina , Poliuretanos , Polímeros
7.
Front Robot AI ; 9: 799893, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35494543

RESUMEN

The rise of deep learning has caused a paradigm shift in robotics research, favoring methods that require large amounts of data. Unfortunately, it is prohibitively expensive to generate such data sets on a physical platform. Therefore, state-of-the-art approaches learn in simulation where data generation is fast as well as inexpensive and subsequently transfer the knowledge to the real robot (sim-to-real). Despite becoming increasingly realistic, all simulators are by construction based on models, hence inevitably imperfect. This raises the question of how simulators can be modified to facilitate learning robot control policies and overcome the mismatch between simulation and reality, often called the "reality gap." We provide a comprehensive review of sim-to-real research for robotics, focusing on a technique named "domain randomization" which is a method for learning from randomized simulations.

8.
Psychiatr Rehabil J ; 45(3): 219-225, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35298226

RESUMEN

OBJECTIVE: There is growing interest in using mobile health (mHealth) devices to monitor physiological stress associated with mental deterioration. Research is currently examining whether physiological information returned to individuals with serious mental illness (SMI) and their clinicians enhances early intervention. The aim of this study was to explore patient and clinician-related acceptability of an mHealth device to monitor stress for SMI. METHOD: Individuals with SMI and their clinicians at a community youth mental health service were shown how an mHealth device could be used to monitor stress. Focus groups and interviews regarding the acceptability of the mHealth device were then conducted with participants (N = 22). Content was transcribed and analyzed using an inductive thematic analysis focusing on perceptions of potential benefit, barriers and facilitators of uptake. RESULTS: Six themes were identified. Individuals with SMI and clinicians identified two themes related to benefits of the mHealth device: (a) self-monitoring improves symptom insight and (b) clinician monitoring as a benefit to treatment. They identified one barrier theme: (c) privacy and data misuse concerns. They also identified three facilitators of uptake: (d) ease of use, (e) engaging design and (f) procedural guidelines. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: The perceived benefits of passive physiological monitoring afforded by an mHealth device come with concerns regarding its privacy and the potential for ambiguity in the patient-clinician relationship. Results suggest the importance of codesign to ensure that it is secure, easy to use and engaging. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Asunto(s)
Trastornos Mentales , Telemedicina , Adolescente , Humanos , Trastornos Mentales/diagnóstico , Trastornos Mentales/terapia , Monitoreo Fisiológico , Investigación Cualitativa , Estrés Fisiológico , Telemedicina/métodos
9.
Arq Bras Oftalmol ; 84(5): 474-480, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34320109

RESUMEN

PURPOSE: The aim of this study was to analyze patient data and the laboratory results of corneal samples collected from patients followed at the Ophthalmology Department, Hospital São Paulo, Brazil over a 30-year period, and correlate the analize with contact lens wearing. METHODS: Corneal samples from patients diagnosed clinically with microbial keratitis between January 1987 and December 2016 were included in this study. Cultures that were positive for bacteria, fungi, and Acanthamoeba spp. were analyzed retrospectively. To ascertain if the number of patients with contact-lens-associated microbial keratitis (as a risk factor for microbial infection) changed over time, the analysis was divided into three decades: 1987-1996, 1997-2006, and 2007-2016. Information pertaining to patient gender and age, as well as type of organism isolated, were compared among these periods. RESULTS: The corneal samples of 10.562 patients with a clinical diagnosis of microbial keratitis were included in the study, among which 1.848 cases were related to the use of contact lenses. The results revealed that the frequency of contact-lens-associated microbial keratitis increased over the last two decades. Overall, females had contact-lens-associated microbial keratitis more frequently (59.5%). Patients aged 19-40 years also had contact-lens-associated microbial keratitis more frequently in all study periods. Staphylococcus spp. and Pseudomonas spp. were the most frequent Gram-positive and Gram-negative bacteria, respectively, in the microbial keratitis groups. Among the fungal cases of microbial keratitis, filamentous fungi were the most frequent fungi over the entire study period, with Fusarium spp. being the most frequent fungi in the group with microbial keratitis not associated with contact lens wearing (p<0.001). Samples positive for Acanthamoeba spp. and Pseudomonas spp. were significantly correlated with contact-lens-associated microbial keratitis (p<0.001). CONCLUSIONS: Females and young adults aged 19-40 years exhibited the highest frequency of contact-lens-associated microbial keratitis in our study. Staphylococcus spp. and Fusarium spp. were the predominant bacteria and fungi, respectively, isolated from corneal samples. Pseudomonas spp. and Acanthamoeba spp. were significantly correlated with contact-lens-associated microbial keratitis in this study.


Asunto(s)
Lentes de Contacto , Queratitis , Antibacterianos , Brasil/epidemiología , Lentes de Contacto/efectos adversos , Femenino , Bacterias Gramnegativas , Bacterias Grampositivas , Hospitales , Humanos , Queratitis/epidemiología , Derivación y Consulta , Estudios Retrospectivos , Adulto Joven
10.
Int J Biol Macromol ; 186: 218-226, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34246672

RESUMEN

The extraction of nanochitin from marine waste has attracted great industrial interest due to its unique properties, namely biodegradability, biocompatibility and as a functional reinforcing agent. Conventional acid hydrolysis isolation of nanochitin requires high temperatures and acid concentration, time and energy. Herein, for the first time, microwave irradiation method was used as an eco-friendly approach to isolate nanochitin from different sources. The isolation conditions were optimized through an experimental Box-Behnken design using surface response methodology. The data showed optimal conditions of 1 M HCl, 10.00 min and 124.75 W to obtain lobster nanocrystals; 1 M HCl, 14.34 min and 50.21 W to obtain shrimp nanocrystals; and 1 M HCl, 29.08 min and 54.08 W to obtain squid pen nanofibres, reducing time and HCl concentration. The obtained isolation yields where of 85.30, 79.92 and 80.59 % for lobster, shrimp and squid, respectively. The morphology of the nanochitins was dependent of the chitin origin, and the lengths of the nanochitins were of 314.74, 386.12 and > 900 nm for lobster, shrimp and squid pen, respectively. The thermal stability of the ensuing nanochitins was maintained after treatment. The results showed that nanochitin could be obtained by using an eco-friendly approach like microwave irradiation.


Asunto(s)
Quitina/aislamiento & purificación , Tecnología Química Verde , Microondas , Nanofibras , Nanopartículas , Alimentos Marinos , Residuos , Animales , Conformación de Carbohidratos , Fraccionamiento Químico , Decapodiformes/química , Manipulación de Alimentos , Ácido Clorhídrico/química , Concentración de Iones de Hidrógeno , Hidrólisis , Nephropidae/química , Penaeidae/química , Relación Estructura-Actividad , Factores de Tiempo
11.
JMIR Res Protoc ; 9(11): e19510, 2020 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-33136053

RESUMEN

BACKGROUND: Symptoms of mental illness are often triggered by stress, and individuals with mental illness are sensitive to these effects. The development of mobile health (mHealth) devices allows continuous recording of biometrics associated with activity, sleep, and arousal. Deviations in these measures could indicate a stressed state requiring early intervention. This paper describes a protocol for integrating an mHealth device into a community mental health team to enhance management of severe mental illness in young adults. OBJECTIVE: The aim of this study is to examine (1) whether an mHealth device integrated into a community mental health team can improve outcomes for young adults with severe mental illness and (2) whether the device detects periods of mental health versus deterioration. METHODS: This study examines whether physiological information from an mHealth device prevents mental deterioration when shared with the participant and clinical team versus with the participant alone. A randomized controlled trial (RCT) will allocate 126 young adults from community mental health services for 6 months to standard case management combined with an integrated mHealth device (ie, physiological information is viewed by both participant and case manager: unWIRED intervention) or an unintegrated mHealth device (ie, participant alone self-monitors: control). Participants will wear the Empatica Embrace2 device, which continuously records electrodermal activity and actigraphy (ie, rest and activity). The study also examines whether the Embrace2 can detect periods of mental health versus deterioration. A variety of measurements will be taken, including physiological data from the Embrace2; participant and case manager self-report regarding symptoms, functioning, and quality of life; chart reviews; and ecological momentary assessments of stress in real time. Changes in each participant's Clinical Global Impression Scale scores will be assessed by blinded raters as the primary outcome. In addition, participants and case managers will provide qualitative data regarding their experience with the integrated mHealth device, which will be thematically analyzed. RESULTS: The study has received ethical approval from the Western Sydney Local Health District Human Research Ethics Committee. It is due to start in October 2020 and conclude in October 2022. CONCLUSIONS: The RCT will provide insight as to whether an integrated mHealth device enables case managers and participants to pre-emptively manage early warning signs and prevent relapse. We anticipate that unWIRED will enhance early intervention by improving detection of stress and allowing case managers and patients to better engage and respond to symptoms. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12620000642987; https://www.anzctr.org.au/ACTRN12620000642987.aspx. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/19510.

12.
Bioresour Technol ; 315: 123896, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32726745

RESUMEN

In this work, an integral valorisation of almond shells through a biorefinery approach was studied. The three main components of almond shells were extracted, isolated and characterised. The autohydrolysis process permitted the extraction of the hemicellulosic fraction obtaining a liquor rich in xylooligosaccharides (22.12 g/L). Then, two different delignification processes, alkaline and organosolv treatments, were proposed to obtain a very high purity lignin (≈90%) which could be further valorised for a wide variety of applications. The valorisation of the high cellulosic content of the delignified solids was carried out using two different methods. On the one hand, producing cellulose nanocrystals and on the other hand obtaining glucose by an enzymatic hydrolysis as well as a spent solid mainly composed by lignin (≈78 wt%). Thus, the proposed biorefinery approach could contribute to a circular economy as all the main components of the almond shells could be revalorised by environmentally friendly procedures.


Asunto(s)
Prunus dulcis , Celulosa , Hidrólisis , Lignina
13.
Arq. bras. oftalmol ; 84(5): 474-480, Sept.-Oct. 2021. tab
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1339208

RESUMEN

ABSTRACT Purpose: The aim of this study was to analyze patient data and the laboratory results of corneal samples collected from patients followed at the Ophthalmology Department, Hospital São Paulo, Brazil over a 30-year period, and correlate the analize with contact lens wearing. Methods: Corneal samples from patients diagnosed clinically with microbial keratitis between January 1987 and December 2016 were included in this study. Cultures that were positive for bacteria, fungi, and Acanthamoeba spp. were analyzed retrospectively. To ascertain if the number of patients with contact-lens-associated microbial keratitis (as a risk factor for microbial infection) changed over time, the analysis was divided into three decades: 1987-1996, 1997-2006, and 2007-2016. Information pertaining to patient gender and age, as well as type of organism isolated, were compared among these periods. Results: The corneal samples of 10.562 patients with a clinical diagnosis of microbial keratitis were included in the study, among which 1.848 cases were related to the use of contact lenses. The results revealed that the frequency of contact-lens-associated microbial keratitis increased over the last two decades. Overall, females had contact-lens-associated microbial keratitis more frequently (59.5%). Patients aged 19-40 years also had contact-lens-associated microbial keratitis more frequently in all study periods. Staphylococcus spp. and Pseudomonas spp. were the most frequent Gram-positive and Gram-negative bacteria, respectively, in the microbial keratitis groups. Among the fungal cases of microbial keratitis, filamentous fungi were the most frequent fungi over the entire study period, with Fusarium spp. being the most frequent fungi in the group with microbial keratitis not associated with contact lens wearing (p<0.001). Samples positive for Acanthamoeba spp. and Pseudomonas spp. were significantly correlated with contact-lens-associated microbial keratitis (p<0.001). Conclusions: Females and young adults aged 19-40 years exhibited the highest frequency of contact-lens-associated microbial keratitis in our study. Staphylococcus spp. and Fusarium spp. were the predominant bacteria and fungi, respectively, isolated from corneal samples. Pseudomonas spp. and Acanthamoeba spp. were significantly correlated with contact-lens-associated microbial keratitis in this study.


RESUMO Objetivo: O objetivo deste estudo foi analisar da dos epidemiológicos de pacientes e resultados laboratoriais para todas as amostras de córnea coletadas de pacientes atendidos no Departamento de Oftalmologia do Hospital São Paulo, Brasil, durante um período de 30 anos e correlacionar com o uso de lentes de contato. Métodos: Amostras de córnea de pacientes com diagnóstico clínico de ceratite microbiana (de janeiro de 1987 a dezembro de 2016) foram incluídas neste estudo. Resultados laboratoriais para culturas positivas para bactérias, fungos e Acanthamoeba spp. foram analisados retrospectivamente. Para verificar se o número de pacientes com ceratite microbiana associada à lente de contato, fator de risco para infecção microbiana, mudou ao longo do tempo, a análise foi dividida em três décadas: 1987-1996, 1997-2006 e 2007-2016. As informações incluindo o sexo do paciente, idade e tipo de organismo isolado foram comparadas entre os períodos. A análise estatística foi realizada no software SAS/STAT 9.3 e SPSS (v20.0). Resultados: Amostras de córnea de 10.562 pacientes com ceratite microbiana foram incluídas no estudo, das quais 1.848 foram relacionadas ao uso de lentes de contato. Os resultados revelaram que a frequência de ceratite microbiana associada à lente de contato aumentou nas últimas duas décadas analisadas. No geral, os homens compreendiam uma proporção maior do grupo ceratite microbiana não associada à lente de contato (CMNLC) (60,3%) e as mulheres eram mais frequentes no grupo ceratite microbiana associada à lente de contato (59,5%). Pacientes com idade entre 19 e 40 anos foram mais frequentemente observados no grupo ceratite microbiana associada à lente de contato em todos os períodos. Staphylococcus spp. foi a bactéria Gram-positiva mais frequentes, enquanto Pseudomonas spp. foi a bactéria Gram-negativa nos grupos ceratite microbiana. Entre os fungos ceratite microbiana, os fungos filamentosos foram os fungos mais frequentes durante todo o período do estudo, com Fusarium spp. sendo o mais frequente no grupo ceratite microbiana não associada à lente de contato. Acanthamoeba spp. e Pseudomonas spp. amostras positivas foram significativamente correlacionadas com ceratite microbiana associada à lente de contato. Conclusões: A maior prevalência de ceratite microbiana associada à lente de contato no nosso estudo foi observada em mulheres e adultos jovens com idade entre 19 e 40 anos. Staphylococcus spp. e Fusarium spp. foram as bactérias e fungos predominantes isolados nas amostras da córnea. Pseudomonas spp. e Acanthamoeba spp. foram significativamente correlacionados a ceratite microbiana associada à lente de contato neste estudo.

14.
Artículo en Inglés | MEDLINE | ID: mdl-23367462

RESUMEN

Falls are a common problem in the elderly population, and their prediction has been a major interest for the medical field. The relationship between stumbles and falls has not been very well understood yet. A critical requirement in advancing the study of this relationship is the realization of a realistic and effective stumble detection system. In this paper, we present a system for the detection of stumbles during walking. Our system consists of a single low cost triaxial accelerometer that may be worn by patients and is convenient for a wide range of subjects. We formulate the problem as an anomaly detection and we validate our system with a large data set collected from 9 subjects. The data set contains a total of 100 stumbles and 45 minutes of walking. We compare 7 different placements for the accelerometer, and show that our system achieves a 99% detection rate, with a 0.2% false alarm rate using an accelerometer worn on the chest.


Asunto(s)
Acelerometría/instrumentación , Accidentes por Caídas/prevención & control , Monitoreo Ambulatorio/instrumentación , Anciano , Algoritmos , Fenómenos Biomecánicos , Humanos , Modelos Estadísticos , Monitoreo Ambulatorio/métodos , Músculos/fisiopatología , Riesgo , Caminata
15.
Rev. bras. cineantropom. desempenho hum ; 14(3): 324-332, 2012. ilus, tab
Artículo en Español | LILACS | ID: lil-624477

RESUMEN

La L-carnitina tiene un gran valor en procesos metabólicos al cumplir un papel importante en el proceso de β -oxidación mitocondrial, por lo cual, podría ser usada para mejorar el rendimiento atlético y mantener una carga de trabajo. Este trabajo tuvo por objetivo evaluar los efectos de la suplementación de L-carnitina y del entrenamiento en el tiempo necesario a la inducción de la fatiga muscular en preparaciones in situ del nervio ciático y músculo gastronemio en ratas. Cuatro grupos de animales fueron constituidos: sedentario no suplementado (SNS), sedentario suplementado (SS), entrenado no suplementado (ENS) y entrenado suplementado (ES). El entrenamiento fue realizado en sesiones diarias (1h/5dias/semana) y con suplementación oral crónica de L-Carnitina (1mg/ml) por 4 semanas. La fatiga muscular fue obtenida mediante estimulación supra-maximal tetánica del nervio ciático (50 Hz). Los valores del tiempo para la reducción de fuerza fueron significativamente diferentes (p< 0,05) entre los grupos SNS vs SS y ENS vs ES, respectivamente. Sin embargo, no hubo diferencias significativas entre los grupos ES vs SS y ENS vs SNS. Estos resultados demuestran que la L-carnitina prolongo el tiempo necesario para la reducción de fuerza a nivel del músculo gastrocnemio.


L-carnitine, considered to be of great value in metabolic processes, plays an important role in the mitochondrial β -oxidation process. It may be used to improve athletic performance and to maintain a higher workload during exercise. This study aimed to investigate the effect of L-carnitine supplementation on muscle fatigue in sciatic nerve-gastrocnemius muscle preparations in sedentary and trained rats. The animals were divided into 4 groups: non-supplemented sedentary (NSS), supplemented sedentary (SS), non-supplemented trained (NST), and supplemented trained (ST) rats. The animals were trained in daily 1-h sessions (5 days/week) and received chronic oral L-carnitine supplementation (1 mg/mL) for 4 weeks. Muscle fatigue was determined by supramaximal tetanic stimulation of the sciatic nerve (50 Hz). Time values for strength reduction were significantly different (p< 0.05) between NSS vs. SS and NST vs. ST rats. No significant differences were observed between SS vs. ST and NST vs. NSS rats. These findings demonstrate that L-carnitine lengthen the time required for induction of muscle fatigue.

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