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AIM: Greater quantification and characterisation of training load (TL) throughout Live-high, train-high (LHTH) altitude (ALT) training is required to identify periodisation strategies that may lead to physiological and performance improvements in swimmers. PURPOSE: This study aimed to examine the physiological responses and performance outcomes of 14 high-performance swimmers (FINA points: 836.0 ± 35.1) following 3 weeks of LHTH at 2320 m, while characterising the training load periodisation strategy adopted during the intervention. METHODS: Haemoglobin (Hb) mass was measured pre-, 7 and 14 days post-ALT via CO rebreathing. Performance in each athlete's primary event at national standard meets were converted to FINA points and compared from pre-to-post-ALT. TL was quantified at sea level (SL) and ALT through session rating of perceived exertion (RPE), where duration of each session was multiplied by its RPE for each athlete, with all sessions totalled to give a weekly TL. Pre-to-post-ALT changes were evaluated using repeated-measures ANOVA. RESULTS: Hb mass increased significantly from 798 ± 182 g pre-ALT to 828 ± 187 g at 7 days post (p = 0.013) and 833 ± 205 g 14 days post-ALT (p = 0.026). Weekly TL increased from SL (3179 ± 638 au) during week one (4797 ± 1349 au, p < 0.001) and week two (4373 ± 967 au, p < 0.001), but not week three (3511 ± 730 au, p = 0.149). No evidence of improved SL swimming performance was identified. CONCLUSION: A periodisation strategy characterised by a sharp spike in TL followed by a slight de-load towards the end of a LHTH intervention led to improved physiological characteristics but no change in the competitive performance of high-performance swimmers.
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Altitud , Rendimiento Atlético , Hemoglobinas , Natación , Humanos , Natación/fisiología , Masculino , Rendimiento Atlético/fisiología , Hemoglobinas/metabolismo , Adulto Joven , Femenino , Adulto , Adolescente , Atletas , Acondicionamiento Físico Humano/métodos , Acondicionamiento Físico Humano/fisiología , Esfuerzo Físico/fisiologíaRESUMEN
Experiencing mental fatigue (MF) before an orienteering race can lead to a slower completion time. This study aimed to explore the changes in perceived MF, mood and other psychological responses during an orienteering competition. Sixteen national level orienteering athletes (20.8 ± 4.9 years) provided informed consent and completed the online surveys, before and immediately after each race, and 24- and 48-hours post competition (48POST). This study measured MF, physical fatigue, stress, tiredness and motivation using 0-100 Visual Analogue Scale, and the mood was assessed using The Brunel Mood Scale (BRUMS). A moderate to large increase in MF (ES = 0.93 [0.54 to 1.31]), BRUMS fatigue (ES = 0.61 [0.3 to 0.92]), and PF (ES = 1.21 [0.81 to 1.61]) was reported following orienteering races. A small increase in tiredness and BRUMS confusion, and a small decrease in motivation, stress and BRUMS vigour was also reported. There was a delay in recovering from the MF elicited by competition, with a small increase in MF (ES = 0.54 [0.08 to 1.15]) at 48POST compared to the pre-competition value. This study found that orienteers experience MF during competition and have a delayed recovery that can last up to two days after the competition.
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Carrera , Humanos , Carrera/fisiología , Atletas/psicología , Afecto , Motivación , Examen Físico , Fatiga MentalRESUMEN
This study sought to assess the validity of contact involvement (CI) detection using microsensor technology (MST, Catapult Vector) within the context of a Tier One national rugby union (RU) squad, consisting of 44 players. Sensitivity of MST units to detect CI and scrums was assessed in eight test matches, by comparison with match data obtained by video analysis. This paper is the first to assess the sensitivity of MST to the full range of skilled CI which occur in RU, including evaluating "non-performance" collisions, such as incidental collisions or foul play. Sensitivity to tackles made (52.9-84.9%) and ruck hits (53.3-87.2%) was lower than previous research, although ball carries (71.9-93.5%) showed broadly similar sensitivity to established results. The sensitivity of the MST to detect scrums was substantially lower than previous findings, with large positional variation evident (51.4-91.5%). Further refinement of MST software should be considered in order to facilitate valid monitoring of RU performance and injury risk. An additional finding was that video analysis generally demonstrated satisfactory intrarater reliability. This result supports the use of video analysis as a reliable method of assessing RU performance, including CI.
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Fútbol Americano , Rugby , Humanos , Reproducibilidad de los Resultados , Fútbol Americano/lesionesRESUMEN
Orienteering is an outdoor activity wherein participants use a map and compass to locate control points and choose the quickest path to the next control point in a natural environment. Attentional focus, rapid decision-making, and high aerobic fitness may influence orienteering performance. Therefore, this research aimed to seek international orienteering expert consensus regarding the definition, development, causes, influences and methods to reduce mental fatigue (MF) in orienteering based on practical experience. Following ethical approval, a three-round Delphi survey was conducted online with twenty-four orienteering coaches and athletes (or former athletes) from 10 different countries with international orienteering competition experience. The threshold of consensus was ≥ 70% agreement among respondents. The experts agreed that MF exists in daily life and orienteering with a substantial negative effect on their conscious decision-making performance and psychological responses. The experts disagreed that the form of MF that athletes experienced in orienteering training are similar to the competition. However, there was no agreement that MF would impact endurance and high-speed running performance during orienteering. This research refines the definition of MF and summarises the distinctions in what causes MF in orienteering training and competition, implying that MF should be addressed separately.
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Carrera , Humanos , Consenso , Técnica Delphi , Carrera/fisiología , Atletas , AtenciónRESUMEN
OBJECTIVE: Concussion education strategies that improve knowledge and attitudes long term are needed. This exploratory study piloted an interactive concussion education program, adopting concepts from the learning sciences and attitude change literature, for the underserved and high-risk population of motorsports. METHOD: Forty UK motorsport drivers (ages 16-20 years) participated. The workshop group received a two-phased workshop-based program. The comparison group received a concussion leaflet. Participants completed an adapted version of the Rosenbaum Concussion Knowledge and Attitudes Survey (RoCKAS-ST) at pre-, post- and 2-month follow-up. Within-group analysis for the workshop group explored the differential effect of the individual difference variable, Need for Cognition (NfC), and effectiveness was explored through post-workshop questionnaires and interviews. RESULTS: Unlike the comparison group, the workshop group showed a significant improvement in knowledge over time (F(2,58) = 45.49, p < .001, η2p = .61). Qualitative data indicated workshop-program participants developed safer attitudes toward concussion following programming. Preliminary evidence suggested individuals' responses to concussion education aligned with differences in NfC. CONCLUSION: This study piloted the first concussion education program for motorsport drivers and explored whether aligning educational provision with the NfC construct may help to improve program effectiveness. Findings are relevant to addressing the public health issue of concussion through educational approaches.
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Traumatismos en Atletas , Conmoción Encefálica , Adolescente , Adulto , Conmoción Encefálica/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Proyectos Piloto , Encuestas y Cuestionarios , Adulto JovenRESUMEN
A breakpoint in a portable near-infrared spectroscopy (NIRS) derived deoxygenated haemoglobin (deoxy[Hb]) signal during an incremental VO2max running test has been associated with the second ventilatory threshold (VT2) in healthy participants. Thus, the aim was to examine the association between this breakpoint (NIRS) and VT2 in well-trained runners. Gas exchange and NIRS data were collected during an incremental VO2max running test for 10 well-trained runners. The breakpoint calculated in oxygen saturation (StO2) and the VT2 were determined and compared in terms relative to %VO2max, absolute speed, VO2, and maximum heart rate (HRmax). There were no significant differences (p>0.05) between the breakpoint in StO2 and VT2 relative to %VO2max (87.00±6.14 and 88.28 ± 3.98 %), absolute speed (15.70±1.42 and 16.10±1.66 km·h-1), VO2 (53.71±15.17 and 54.66±15.57 ml·kg-1·min-1), and%HRmax (90.90±4.17 and 91.84±3.70%). There were large and significant correlations between instruments relative to%VO2max (r=0.68, p<0.05), absolute speed (r=0.86, p<0.001), VO2 (r=0.86, p<0.001), and %HRmax (r=0.69; p<0.05). A Bland and Altman analysis of agreement between instruments resulted in a mean difference of - 1.27±4.49%, -0.40±0.84 km·h-1,-0.90±3.07 ml·kg-1·min-1, and - 0.94±3.14 for %VO2max, absolute speed, VO2, and %HRmax, respectively. We conclude that a portable NIRS determination of the StO2 breakpoint is comparable with VT2 using gas exchange and therefore appropriate for use in determining exercise training above VT2 intensity. This is the first study to analyze the validity with the running mode using a NIRS portable device.
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Prueba de Esfuerzo/métodos , Consumo de Oxígeno , Espectroscopía Infrarroja Corta , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Carrera/fisiología , Adulto JovenRESUMEN
OBJECTIVE: To assess concussion experiences, knowledge, and attitudes of motorsport medical personnel and drivers and to determine priority areas regarding concussion within the sport. DESIGN: Sequential mixed-method design. Part 1: stakeholder interviews; part 2: cross-sectional online survey. SETTING: United Kingdom. PARTICIPANTS: Part 1: key motorsport stakeholders (N = 8); part 2: motorsport medical personnel and drivers (N = 209) representing amateur and/or professional 4-wheeled motorsport. MAIN OUTCOME MEASURES: Concussion experience, knowledge, attitudes, and perceived priority areas. RESULTS: Thirty-one percent of surveyed drivers (age = 37.91 ± 13.49 years: 89% male) reported suffering from concussion in motorsport. Eighty-seven percent of surveyed medical personnel (age = 48.60 ± 10.68 years: 74% male) reported experience with concussed drivers, and 34% reported feeling pressured to clear a driver with concussion. Gaps in knowledge and misperceptions about concussion were reported in both groups, and disparity between concussion attitudes emerged between drivers and medical personnel. Application of assessment and management procedures varied between medical personnel and there was evidence motorsport policy and concussion guidelines may not be directly followed. According to both medical personnel (77%) and drivers (85%), "education and training" is the top priority area for the sport. CONCLUSIONS: There is clear evidence of concussions in motorsport, but accurate knowledge about this injury is missing. Concussion education and training for all drivers and medical personnel is required. Additional investigations into concussion attitudes are advised to complement and advance simple educational initiatives. Further investigation is also required to determine how to best support motorsport medical personnel, and general practitioners, who hold significant responsibility in guiding drivers from diagnosis to return to racing, and to support the effective implementation of policy.
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Traumatismos en Atletas/epidemiología , Conducción de Automóvil/estadística & datos numéricos , Conmoción Encefálica/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Cuerpo Médico/estadística & datos numéricos , Participación de los Interesados , Adulto , Traumatismos en Atletas/complicaciones , Traumatismos en Atletas/diagnóstico , Actitud , Conmoción Encefálica/complicaciones , Conmoción Encefálica/diagnóstico , Competencia Clínica , Femenino , Médicos Generales/educación , Humanos , Masculino , Cuerpo Médico/educación , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Alta del Paciente , Investigación Cualitativa , Volver al Deporte , Encuestas y Cuestionarios/estadística & datos numéricos , Evaluación de Síntomas , Reino Unido/epidemiologíaRESUMEN
This study compared affective responses to low volume high-intensity interval exercise (HIIE), moderate-intensity continuous exercise (MICE) and high-intensity continuous exercise (HICE). Twelve untrained males ([Formula: see text] 48.2 ± 6.7 ml·kg-1·min-1) completed MICE (30 min cycle at 85% of ventilatory threshold (VT)), HICE (cycle at 105% of VT matched with MICE for total work), and HIIE (10 x 6 s cycle sprints with 60 s recovery). Affective valence and perceived activation were measured before exercise, post warm-up, every 20% of exercise time, and 1, 5, 10, and 15 min post-exercise. Affective valence during exercise declined by 1.75 ± 2.42, 1.17 ± 1.99, and 0.42 ± 1.38 units in HICE, HIIE, and MICE, respectively, but was not statistically influenced by trial (P = 0.35), time (P = 0.06), or interaction effect (P = 0.08). Affective valence during HICE and HIIE was consistently less positive than MICE. Affective valence post-exercise was not statistically influenced by trial (P = 0.10) and at 5 min post-exercise exceeded end-exercise values (P = 0.048). Circumplex profiles showed no negative affect in any trial. Affective responses to low volume HIIE are similar to HICE but remain positive and rebound rapidly, suggesting it may be a potential alternative exercise prescription.
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Afecto/fisiología , Ejercicio Físico/psicología , Entrenamiento de Intervalos de Alta Intensidad/psicología , Adulto , Estudios Cruzados , Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Percepción , Adulto JovenRESUMEN
Dempsey, GM, Gibson, NV, Sykes, D, Pryjmachuk, BC, and Turner, AP. Match demands of senior and junior players during International Rugby League. J Strength Cond Res 32(6): 1678-1684, 2018-This study aims to quantify and compare the positional game demands of international junior and senior rugby league competition for the first time. Global positioning system (GPS) and video analysis were used to track 118 elite male rugby league players (57 seniors aged 28.7 ± 4.4 years; 61 juniors aged 17.2 ± 0.5 years) over 10 international matches (6 senior; 4 junior) characterized as either forwards (n = 67) or backs (n = 51). There were significant increases in the offensive carries (0.18 cf. 0.09 n·min; r = 0.56) and defensive tackles (0.36 cf. 0.23 n·min; r = 0.3) between senior and junior players, and forwards and backs (0.16 cf. 0.09; r = 0.34 and 0.41 cf. 0.14; r = 0.52), respectively. Running demands were significantly greater in backs than forwards (independent of playing level) for total distance (6,962 ± 1,263 m cf. 4,879 ± 1,824 m; r = 0.55), individualized high-speed distances (310 ± 158 m cf. 250 ± 171 m; r = 0.2), high-intensity accelerations (28.7 ± 12.1 m·s cf. 21.9 ± 11.7 m·s; r = 0.27), and decelerations (57.2 ± 18.3 m·s cf. 43.0 ± 17.8 m·s; r = 0.38). Positional differences were eliminated when reported relative to minutes played. From a practical perspective, although running demands relative to time on the pitch may prepare junior players for senior competition, it is not representative of the increased body mass and contact frequency within the senior game. Coaches should therefore reflect these differences within their physical preparation programs to prepare junior athletes accordingly for progression to the senior level.
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Fútbol Americano , Esfuerzo Físico , Carrera , Aceleración , Adolescente , Adulto , Rendimiento Atlético , Desaceleración , Sistemas de Información Geográfica , Humanos , Masculino , Factores de Tiempo , Grabación en Video , Adulto JovenRESUMEN
Single molecule enzymology provides an opportunity to examine details of enzyme mechanisms that are not distinguishable in biomolecule ensemble studies. Here we report, for the first time, detection of the current produced in an electrocatalytic reaction by a single redox enzyme molecule when it collides with an ultramicroelectrode. The catalytic process provides amplification of the current from electron-transfer events at the catalyst leading to a measurable current. This new methodology monitors turnover of a single enzyme molecule. The methodology might complement existing single molecule techniques, giving further insights into enzymatic mechanisms and filling the gap between fundamental understanding of biocatalytic processes and their potential for bioenergy production.
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Lacasa/química , Lacasa/metabolismo , Modelos Químicos , Biocatálisis , Electroquímica , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Modelos Moleculares , Oxidación-Reducción , Polyporales/enzimología , Conformación Proteica , TermodinámicaRESUMEN
A single-probe strip test for the rapid and sensitive detection of miRNA-21 mimics is reported herein. Highly specific structurally responsive bi-functional, thiol and biotin, DNA/LNA oligonucleotide probes (molecular beacons-MB) were designed and conjugated with gold nanoparticles (AuNPs) (i.e. biotin-MB-AuNPs). The proposed design had the ability to modulate the accessibility of the biotin group as a function of the presence of a miRNA target allowing the interaction of the boilable with the streptavidin test zone only in the presence of the miRNA-21 mimics. For quantitative evaluation, images of the strip tests were recorded using a flatbed scanner (Epson Perfection V370 Photo). The colour intensities of the test zones of the strip tests were analysed with the ImageJ software (Scion Corp., USA) and quantified as a function of pixel intensity. The response of the strip test was linear over the range 0.5 to 20 nM miRNA-21 (limit of detection of 115 pM) and showed good reproducibility (intra and inter CVs below 8%); furthermore, the assay was shown to be highly selective, discriminating other interference miRNAs mimics (e.g. miRNA-221 and miRNA-205). Finally, the proposed strip test was used for detection of miRNA-21 mimics in spiked serum samples, demonstrating its potential for point-of-care clinical applications. Main advantages of the single-probe strip test design are its versatility, simplicity and robustness, which can be easily extended to other miRNA targets by tuning the sequence of the single probe. Furthermore, the use of the structurally responsive single probe is particularly relevant in the case of short-length targets, such as miRNA, whereas a conventional sandwich approach might require a careful control of assay conditions such as hybridization temperature and salt concentration.
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Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Oro/química , Nanopartículas del Metal/química , MicroARNs/sangre , Sondas de Oligonucleótidos/química , Humanos , Límite de Detección , Sistemas de Atención de PuntoRESUMEN
The purpose of this study was to investigate the effects of a 5-week lower-limb unilateral or bilateral strength program on measures of strength, sprinting, and change of direction speed. Eighteen academy rugby players (18.1 ± 0.5 years, 97.4 ± 11.3 kg, 183.7 ± 11.3 cm) were randomly assigned to either a unilateral (UNI) or bilateral (BI) group. The UNI group squatted exclusively with the rear elevated split squat (RESS), whereas the BI group trained only with the bilateral back squat (BS). Both groups trained at a relative percentage of the respective 1 repetition maximum (1RM) twice weekly over a 5-week period. Subjects were assessed at baseline and postintervention for 1RM BS, 1RM RESS, 10-m sprint, 40-m sprint, and pro-agility. There was a significant main effect of time for 1RM BS (F1,16 = 86.5, p < 0.001), ES (0.84 < Cohen d < 0.92), 1RM RESS (F1,16 = 133.0, p < 0.001), ES (0.89 < Cohen d < 0.94), 40-m sprint (F1,16 = 14.4, p = 0.002), ES (0.47 < Cohen d < 0.67) and pro-agility (F1,16 = 55.9, p < 0.001), ES (0.77 < Cohen d < 0.89), but not 10-m sprints (F1,16 = 2.69, p = 0.121), ES (0.14 < Cohen d < 0.38). No significant interactions between group and time were observed for any of the dependent variables. This is the first study to suggest that BI and UNI training interventions may be equally efficacious in improving measures of lower-body strength, 40-m speed, and change of direction in academy level rugby players.
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Fútbol Americano/fisiología , Extremidad Inferior/fisiología , Fuerza Muscular/fisiología , Acondicionamiento Físico Humano/métodos , Carrera/fisiología , Adolescente , Rendimiento Atlético/fisiología , Humanos , Masculino , Distribución AleatoriaRESUMEN
A controlled, rapid, and potentiostat-free method has been developed for grafting the diazonium salt (3,5-bis(4-diazophenoxy)benzoic acid tetrafluoroborate (DCOOH)) on gold and carbon substrates, based on a Zn-mediated chemical dediazonation. The highly stable thin layer organic platforms obtained were characterized by cyclic voltammetry, AFM, impedance, XP, and Raman spectroscopies. A dediazonation mechanism based on radical formation is proposed. Finally, DCOOH was proved as a linker to an aminated electroactive probe.
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Recently, one-dimensional nanostructures with different morphologies (such as nanowires, nanorods (NRs), and nanotubes) have become the focus of intensive research, because of their unique properties with potential applications. Among them, zinc oxide (ZnO) nanomaterials has been found to be highly attractive, because of the remarkable potential for applications in many different areas such as solar cells, sensors, piezoelectric devices, photodiode devices, sun screens, antireflection coatings, and photocatalysis. Here, we present an innovative approach to create a new modified textile by direct in situ growth of vertically aligned one-dimensional (1D) ZnO NRs onto textile surfaces, which can serve with potential for biosensing, photocatalysis, and antibacterial applications. ZnO NRs were grown by using a simple aqueous chemical growth method. Results from analyses such as X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that the ZnO NRs were dispersed over the entire surface of the textile. We have demonstrated the following applications of these multifunctional textiles: (1) as a flexible working electrode for the detection of aldicarb (ALD) pesticide, (2) as a photocatalyst for the degradation of organic molecules (i.e., Methylene Blue and Congo Red), and (3) as antibacterial agents against Escherichia coli. The ZnO-based textile exhibited excellent photocatalytic and antibacterial activities, and it showed a promising sensing response. The combination of sensing, photocatalysis, and antibacterial properties provided by the ZnO NRs brings us closer to the concept of smart textiles for wearable sensing without a deodorant and antibacterial control. Perhaps the best known of the products that is available in markets for such purposes are textiles with silver nanoparticles. Our modified textile is thus providing acceptable antibacterial properties, compared to available commercial modified textiles.
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Antibacterianos/química , Técnicas Biosensibles , Nanoestructuras/química , Textiles , Óxido de Zinc/química , Antibacterianos/farmacología , Catálisis , Microscopía Electrónica de Rastreo , Plaguicidas/análisis , Fotoquímica , Óxido de Zinc/farmacologíaRESUMEN
Functional carbon nanotubes (CNT) have attracted much attention for analytical and biomedical applications. This paper describes the fabrication of a cholesterol oxidase (ChOx) immobilised polyaniline (PANI)/CNT composite electrode for the amperometric detection of cholesterol. The prepared ChOx/PANI/CNT/Au bioelectrode bound ChOx via the available functionalties of PANI (-NH2) and CNT (-COOH). Moreover, the CNT creates a network inside the matrix that strengthens the mechanical property of the bioelectrode. The multifunctional matrix is presumed to provide a 3D-mesoporous surface, which substantially enhances enzyme activity. The linear range of the biosensor for cholesterol oleate was 30-280 µM with a response time of 10 sec.
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Compuestos de Anilina/química , Técnicas Biosensibles/instrumentación , Colesterol Oxidasa/química , Colesterol/análisis , Enzimas Inmovilizadas/química , Nanotubos de Carbono/química , Técnicas Biosensibles/métodos , Colesterol/metabolismo , Colesterol Oxidasa/metabolismo , Estabilidad de Enzimas , Enzimas Inmovilizadas/metabolismo , Diseño de Equipo , Glucosa/química , Lactatos/química , Nanocompuestos/químicaRESUMEN
Postactivation potentiation (PAP), an acute and temporary enhancement of muscular performance resulting from previous muscular contraction, commonly occurs after heavy resistance exercise. However, this method of inducing PAP has limited application to the precompetition practices (e.g., warm-up) of many athletes. Very few studies have examined the influence of plyometric activity on subsequent performance; therefore, we aimed to examine the influence of alternate-leg bounding on sprint acceleration performance. In a randomized crossover manner, plyometric-trained men (n = 23) performed seven 20-m sprints (with 10-m splits) at baseline, â¼15 seconds, 2, 4, 8, 12, and 16 minutes after a walking control (C) or 3 sets of 10 repetitions of alternate-leg bounding using body mass (plyometric, P) and body mass plus 10% (weighted plyometric, WP). Mean sprint velocities over 10 and 20 m were similar between trials at baseline. At â¼15 seconds, WP impaired 20-m sprint velocity by 1.4 ± 2.5% when compared with C (p = 0.039). Thereafter, 10- and 20-m sprint velocities improved in WP at 4 minutes (10 m: 2.2 ± 3.1%, p = 0.009; 20 m: 2.3 ± 2.6%, p = 0.001) and 8 minutes (10 m: 2.9 ± 3.6%, p = 0.002; 20 m: 2.6 ± 2.8%, p = 0.001) compared with C. Improved 10-m sprint acceleration performance occurred in P at 4 minutes (1.8 ± 3.3%, p = 0.047) relative to C. Therefore, sprint acceleration performance is enhanced after plyometric exercise providing adequate recovery is given between these activities; however, the effects may differ according to whether additional load is applied. This finding presents a practical method to enhance the precompetition practices of athletes.
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Aceleración , Rendimiento Atlético/fisiología , Ejercicio Pliométrico , Carrera/fisiología , Estudios Cruzados , Humanos , Masculino , Distribución Aleatoria , Adulto JovenRESUMEN
Liver cancer is one of the most common cancers in the world and has no effective cure, especially in later stages. The development of a tangible protocol for early diagnosis of this disease remains a major challenge. In the present manuscript, an aptamer-based, label-free electrochemical biosensor for the sensitive detection of HepG2, a hepatocellular carcinoma cell line, is described. The target cells are captured in a sandwich architecture using TLS11a aptamer covalently attached to a gold surface and a secondary TLS11a aptamer. The application of TLS11a aptamer as a recognition layer resulted in a sensor with high affinity for HepG2 cancer cells in comparison with control cancer cells of human prostate, breast, and colon tumors. The aptasensor delivered a wide linear dynamic range over 1 × 10(2) to 1 × 10(6) cells/mL, with a detection limit of 2 cells/mL. This protocol provides a precise method for sensitive detection of liver cancer with significant advantages in terms of simplicity, low cost, and stability.
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Aptámeros de Péptidos/química , Técnicas Biosensibles , Carcinoma Hepatocelular/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , HumanosRESUMEN
Monitoring the cholesterol level is of great importance, especially for people with high risk of developing heart disease. Here we report on reagentless cholesterol detection in human plasma with a novel single-enzyme, membrane-free, self-powered biosensor, in which both cathodic and anodic bioelectrocatalytic reactions are powered by the same substrate. Cholesterol oxidase was immobilized in a sol-gel matrix on both the cathode and the anode. Hydrogen peroxide, a product of the enzymatic conversion of cholesterol, was electrocatalytically reduced, by the use of Prussian blue, at the cathode. In parallel, cholesterol oxidation catalyzed by mediated cholesterol oxidase occurred at the anode. The analytical performance was assessed for both electrode systems separately. The combination of the two electrodes, formed on high surface-area carbon cloth electrodes, resulted in a self-powered biosensor with enhanced sensitivity (26.0 mA M(-1) cm(-2)), compared to either of the two individual electrodes, and a dynamic range up to 4.1 mM cholesterol. Reagentless cholesterol detection with both electrochemical systems and with the self-powered biosensor was performed and the results were compared with the standard method of colorimetric cholesterol quantification.
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Técnicas Biosensibles , Colesterol/sangre , Catálisis , Colesterol Oxidasa/metabolismo , Enzimas Inmovilizadas/metabolismoRESUMEN
This review is based on the Theophilus Redwood Medal and Award lectures, delivered to Royal Society of Chemistry meetings in the UK and Ireland in 2012, and presents a personal overview of the field of biosensors. The biosensors industry is now worth billions of United States dollars, the topic attracts the attention of national initiatives across the world and tens of thousands of papers have been published in the area. This plethora of information is condensed into a concise account of the key achievements to date. The reasons for success are examined, some of the more exciting emerging technologies are highlighted and the author speculates on the importance of biosensors as a ubiquitous technology of the future for health and the maintenance of wellbeing.
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Técnicas Biosensibles/métodos , Técnicas Biosensibles/economía , Técnicas Biosensibles/instrumentación , Diabetes Mellitus/diagnóstico , Técnicas Electroquímicas , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Glucosa/análisis , Humanos , Impresión Molecular , Nanotecnología , Dispositivo de Identificación por RadiofrecuenciaRESUMEN
PURPOSE: Monitoring performance athletes' training responses can be efficiently completed at competitive events. This study aimed to explore the changes in swimming, countermovement-jump (CMJ), and pull-up (PU) performance following training across a competitive phase, as well as immediately before and after each race. METHODS: Fourteen well-trained male sprint/middle-distance swimmers (height 179 [7] cm, mass 70 [8] kg, age 18 [2] y), from 3 regional training groups, completed CMJ and PU tests before and after the national competitions in October and May, when race performance was also assessed. RESULTS: Swimming race performance was significantly improved from before the national competitions in October to after the national competitions in May (1.8% [3.2%], P = .044, d = 0.60, moderate effect). Although there were no significant changes in PU velocity, CMJ performance significantly improved from before the national competitions in October to after the national competitions in May (mean difference 2.29 cm, P = .004, d = 3.52) and showed before-to-after race decreases (mean difference -1.64 cm, P = .04, d = 2.28). CONCLUSION: Swimming performance and CMJ performance improved as the season progressed, although these improvements were not directly correlated. PU performance did not appear to be sensitive to training or race-induced fatigue, in contrast to CMJ, in this group of male swimmers.