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1.
Nanotechnology ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38955146

RESUMO

We present the electrical characterization of wafer-scale graphene devices fabricated with an industrially-relevant, contact-first integration scheme combined with Al2O3 encapsulation via atomic layer deposition. All the devices show a statistically significant reduction in the Dirac point position, Vcnp, from around + 47V to between -5 and 5 V (on 285 nm SiO2), while maintaining the mobility values. The data and methods presented are relevant for further integration of graphene devices, specifically sensors, at the back-end-of-line of a standard CMOS flow.

2.
Eur J Appl Physiol ; 124(7): 2045-2056, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38386104

RESUMO

PURPOSE: Intestinal permeability is a critical component of gut barrier function. Barrier dysfunction can be triggered by certain stressors such as exercise, and if left unmanaged can lead to local and systemic disorders. The aim of this study was to investigate the effects of a specific whey protein fraction in alleviating exercise-induced gut permeability as assessed by recovery of lactulose/rhamnose (L/R) and lactulose/mannitol (L/M) urinary probes. METHODS: Eight males and eight females (aged 18-50) completed two arms of a double-blind, placebo-controlled, crossover study. For each arm participants performed two baseline intestinal permeability assessments, following which they consumed the treatment (2 g/day of milk powder containing 200 mg of whey protein) or placebo (2 g/day of milk powder) for 14 days, before performing a post-exercise permeability assessment. The exercise protocol involved a 20-min run at 80% of maximal oxygen uptake on a 1% incline. RESULTS: Mixed model analysis revealed an increase in L/R (23%; P < 0.001) and L/M (20%; P < 0.01) recovery following exercise. However, there was no treatment or treatment × exercise effect. CONCLUSION: The exercise protocol utilised in our study induces gut permeability. However, consuming whey protein, at the dose and timing prescribed, is not able to mitigate this effect.


Assuntos
Exercício Físico , Permeabilidade , Proteínas do Soro do Leite , Humanos , Proteínas do Soro do Leite/farmacologia , Proteínas do Soro do Leite/administração & dosagem , Masculino , Adulto , Feminino , Exercício Físico/fisiologia , Permeabilidade/efeitos dos fármacos , Animais , Método Duplo-Cego , Pessoa de Meia-Idade , Adulto Jovem , Lactulose/urina , Lactulose/farmacologia , Estudos Cross-Over , Adolescente , Bovinos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Ramnose/farmacologia , Manitol/farmacologia
3.
Mol Ecol ; 30(19): 4601-4605, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34036646

RESUMO

In a recent paper, "Environmental DNA: What's behind the term? Clarifying the terminology and recommendations for its future use in biomonitoring," Pawlowski et al. argue that the term eDNA should be used to refer to the pool of DNA isolated from environmental samples, as opposed to only extra-organismal DNA from macro-organisms. We agree with this view. However, we are concerned that their proposed two-level terminology specifying sampling environment and targeted taxa is overly simplistic and might hinder rather than improve clear communication about environmental DNA and its use in biomonitoring. This terminology is based on categories that are often difficult to assign and uninformative, and it overlooks a fundamental distinction within eDNA: the type of DNA (organismal or extra-organismal) from which ecological interpretations are derived.


Assuntos
DNA Ambiental , Biodiversidade , DNA/genética , Código de Barras de DNA Taxonômico
4.
J Strength Cond Res ; 35(3): 675-679, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30138236

RESUMO

ABSTRACT: Barnes, MJ, Petterson, A, and Cochrane, DJ. Peak power output and onset of muscle activation during high pull exercise. J Strength Cond Res 35(3): 675-679, 2021-The aim of this study was to determine the percentage of 1 repetition maximum (1RM) at which peak power output occurred during the high pull (HP) exercise. In addition, the onset time of the biceps femoris (BF) and gluteus maximus (GM), across a range of loads, was investigated. Twelve resistance-trained men performed 1RM testing for the HP followed by lifts at 10% increments from 30 to 80% 1RM. During each load of power, output was measured using a linear potentiometer, whereas surface electromyography was recorded from the BF and GM. Peak power output occurred at 70% (1881.9 ± 296.1 W); however, there was no significant difference between loads at 60-80% (all p > 0.05). Loads between 40 and 80% 1RM produced significantly higher power outputs than 30% while 80% generated greater power than 100% 1RM (all p < 0.05). There was no significant (p > 0.05) main effect of muscle or load in the onset of BF (156.5-212.1 ms) or GM (112.1-158.1 ms). Therefore, these results suggest that training at a load between 60 and 80% 1RM may be useful in increasing power in the HP. In addition, activation of 2 of the hip extensors occurs in a relatively synchronous order irrespective of load.


Assuntos
Músculos Isquiossurais , Treinamento Resistido , Exercício Físico , Humanos , Masculino , Força Muscular , Músculo Esquelético , Coxa da Perna , Levantamento de Peso
5.
Clin Transplant ; 34(6): e13845, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32096883

RESUMO

BACKGROUND: Opioid medications are frequently used to address pain among patients with cirrhosis, including those on the liver transplant (LT) waitlist and after transplantation. However, opioid use has been associated with poor allograft outcomes and reduced transplant survival. We examined the impact of opioid use across the spectrum of advanced liver disease, from the initial hepatology consultation for cirrhosis through transplant referral, listing, and the post-LT process. METHODS: The study includes all patients referred for cirrhosis management in a single healthcare system in the United States. Data were extracted retrospectively through medical chart review. RESULTS: Of 414 patients included in the study, 104 (25%) were treated with opioid. Patients on opioids were more likely to be White, have body mass indices (BMI) >30, have HCV, suffer from hepatic encephalopathy, cigarette smokers, and use benzodiazepines concurrently. Higher doses of opioids were associated with multiple emergency department (ED). Eighty-nine underwent LT, including 20 opioid-treated patients. There was no difference found between the opioid and non-opioid groups with regard to allograft loss, ED visits, and hospital readmissions at 2 years post-LT follow-up. CONCLUSIONS: Opioid treatment was common among patients with cirrhosis. We did not find increased negative outcomes among opioid users across the spectrum of cirrhosis. However, the sample for LT patients was small.


Assuntos
Analgésicos Opioides , Transplante de Fígado , Analgésicos Opioides/uso terapêutico , Humanos , Cirrose Hepática , Estudos Retrospectivos , Estados Unidos/epidemiologia , Listas de Espera
6.
J Physiol ; 597(1): 71-88, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30320879

RESUMO

KEY POINTS: One in two female athletes chronically take a combined, monophasic oral contraceptive pill (OCP). Previous thermoregulatory investigations proposed that an endogenous rhythm of the menstrual cycle still occurs with OCP usage. Forthcoming large international sporting events will expose female athletes to hot environments differing in their thermal profile, yet few data exist on how trained women will respond from both a thermoregulatory and performance stand-point. In the present study, we have demonstrated that a small endogenous rhythm of the menstrual cycle still affects Tcore and also that chronic OCP use attenuates the sweating response, whereas behavioural thermoregulation is maintained. Furthermore, humid heat affects both performance and thermoregulatory responses to a greater extent than OCP usage and the menstrual cycle does. ABSTRACT: We studied thermoregulatory responses of ten well-trained ( V̇O2max , 57 ± 7 mL min-1  kg-1 ) women taking a combined, monophasic oral contraceptive pill (OCP) (≥12 months) during exercise in dry and humid heat, across their active OCP cycle. They completed four trials, each of resting and cycling at fixed intensities (125 and 150 W), aiming to assess autonomic regulation, and then a self-paced intensity (30-min work trial) to assess behavioural regulation. Trials were conducted in quasi-follicular (qF) and quasi-luteal (qL) phases in dry (DRY) and humid (HUM) heat matched for wet bulb globe temperature (WBGT) (27°C). During rest and exercise at 125 W, rectal temperature was 0.15°C higher in qL than qF (P = 0.05) independent of environment (P = 0.17). The onset threshold and thermosensitivity of local sweat rate and forearm blood flow relative to mean body temperature was unaffected by the OCP cycle (both P > 0.30). Exercise performance did not differ between quasi-phases (qF: 268 ± 31 kJ, qL: 263 ± 26 kJ, P = 0.31) but was 5 ± 7% higher during DRY than during HUM (273 ± 29 kJ, 258 ± 28 kJ; P = 0.03). Compared to matched eumenorrhoeic athletes, chronic OCP use impaired the sweating onset threshold and thermosensitivity (both P < 0.01). In well-trained, OCP-using women exercising in the heat: (i) a performance-thermoregulatory trade-off occurred that required behavioural adjustment; (ii) humidity impaired performance as a result of reduced evaporative power despite matched WBGT; and (iii) the sudomotor but not behavioural thermoregulatory responses were impaired compared to matched eumenorrhoeic athletes.


Assuntos
Ciclismo/fisiologia , Regulação da Temperatura Corporal , Anticoncepcionais Orais/farmacologia , Estradiol/sangue , Exercício Físico/fisiologia , Progesterona/sangue , Adulto , Feminino , Temperatura Alta , Humanos , Umidade , Ovário/fisiologia , Adulto Jovem
7.
J Strength Cond Res ; 33(9): 2381-2387, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28704311

RESUMO

Barnes, MJ, Miller, A, Reeve, D, and Stewart, RJ. Acute neuromuscular and endocrine responses to two different compound exercises: squat vs. deadlift. J Strength Cond Res 33(9): 2381-2387, 2019-Anecdotally, it is believed that the deadlift exercise brings about greater levels of central fatigue than other exercises; however, no empirical evidence exists to support this view. In addition, little is known about the acute endocrine response to heavy deadlift exercise and how this may differ from other similar compound exercises. Therefore, the aim of this study was to identify and compare the acute, neuromuscular and endocrine responses to squat and deadlift exercises. Ten resistance-trained males completed 8 sets of 2 repetitions at 95% of 1 repetition maximum. Maximum voluntary isometric contraction (MVIC) force of the quadriceps, along with measures of central (voluntary activation [VA] and surface electromyography) and peripheral (electrically evoked control stimulus) fatigue were made before and 5 and 30 minutes after exercise. In addition, salivary testosterone and cortisol were measured at these same time points. MVIC was reduced after the completion of both exercises (p = 0.007); however, no difference between exercises was evident. Similarly, although VA changed over time (p = 0.0001), no difference was observed between exercises. As a measure of peripheral fatigue, force from the control stimulus changed over time (p = 0.003) with a greater decrease evident after the squat (p = 0.034). Electromyography was reduced over time (p = 0.048) but no difference was seen between exercises. No change was seen in testosterone and cortisol. Although a greater absolute load and larger volume load were completed for the deadlift, no difference in central fatigue was evident between the 2 compound exercises. The greater peripheral fatigue observed after squat exercise may be due to the greater work completed by the quadriceps with this exercise. These results suggest that separate periodization, tapering, and programming considerations may be unnecessary when using the squat and deadlift to develop muscular strength.


Assuntos
Fadiga Muscular , Músculo Quadríceps/fisiologia , Treinamento Resistido/métodos , Levantamento de Peso/fisiologia , Adulto , Eletromiografia , Teste de Esforço , Humanos , Hidrocortisona/metabolismo , Contração Isométrica , Masculino , Força Muscular , Treinamento Resistido/efeitos adversos , Saliva/metabolismo , Testosterona/metabolismo , Adulto Jovem
8.
Int J Sport Nutr Exerc Metab ; 28(6): 586-592, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29431536

RESUMO

Pomegranate extract (POMx) has been suggested as an ergogenic aid due to its rich concentration of polyphenols, which are proposed to enhance nitric oxide bioavailability, thereby improving the efficiency of oxygen usage and, consequently, endurance exercise performance. Although acute POMx supplementation improves aerobic exercise performance in untrained individuals, trained athletes appear to require chronic supplementation for a similar effect. Furthermore, the combination of POMx with a thiol antioxidant may prove more effective than POMx alone, due to the protective effects of thiols on nitric oxide. Thus, this study hypothesized that multiday POMx supplementation would decrease the oxygen uptake (VO2) required by trained cyclists to perform submaximal exercise and increase performance during a time trial, and that thiol (N-acetylcysteine [NAC]) cosupplementation would enhance these effects. Eight cyclists completed four 8-day supplementation periods: POMx only, NAC only, POMx + NAC (BOTH), and placebo. Following supplementation, they performed submaximal cycling and a 5-min time trial, with VO2 and muscle oxygen saturation (SmO2) being recorded. A three-way (POMx × NAC × Intensity) repeated-measures analysis of variance with a Fisher's least significant difference post hoc assessment was performed for dependent variables (p ≤ .05). VO2 during submaximal exercise was reduced with POMx versus placebo (-2.6 ml·min-1·kg-1, p = .009) and BOTH (-2.5 ml·min-1·kg-1, p < .05) and increased with NAC (+1.9 ml·min-1·kg-1, p < .03), despite no main effect of treatment on SmO2 or performance. It appears that POMx's high polyphenol content reduced the VO2 required during submaximal exercise. However, NAC cosupplementation annulled this effect; thus, NAC may interact with nitric oxide to reduce its bioavailability.


Assuntos
Acetilcisteína/farmacologia , Ciclismo/fisiologia , Lythraceae/química , Consumo de Oxigênio , Substâncias para Melhoria do Desempenho/administração & dosagem , Fenômenos Fisiológicos da Nutrição Esportiva , Adulto , Desempenho Atlético , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/sangue , Adulto Jovem
9.
J Strength Cond Res ; 32(2): 458-465, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29369954

RESUMO

Pritchard, HJ, Barnes, MJ, Stewart, RJC, Keogh, JWL, and McGuigan, MR. Short-term training cessation as a method of tapering to improve maximal strength. J Strength Cond Res 32(2): 458-465, 2018-The aim of this study was to determine the effects of 2 different durations of training cessation on upper- and lower-body maximal strength performance and to investigate the mechanisms underlying performance changes following short-term training cessation. Eight resistance trained males (23.8 ± 5.4 years, 79.6 ± 10.2 kg, 1.80 ± 0.06 m, relative deadlift 1 repetition maximum of 1.90 ± 0.30 times bodyweight [BW]) each completed two 4-week strength training periods followed by either 3.5 days (3.68 ± 0.12 days) or 5.5 days (5.71 ± 0.13 days) of training cessation. Testing occurred pretraining (T1), on the final day of training (T2), and after each respective period of training cessation (T3). Participants were tested for salivary testosterone and cortisol, plasma creatine kinase, psychological profiles, and performance tests (countermovement jump [CMJ], isometric midthigh pull, and isometric bench press [IBP]) on a force plate. Participants' BW increased significantly over time (p = 0.022). The CMJ height and IBP peak force showed significant increases over time (p = 0.013, 0.048, and 0.004, respectively). Post hoc testing showed a significant increase between T1 and T3 for both CMJ height and IBP peak force (p = 0.022 and 0.008 with effect sizes of 0.30 and 0.21, respectively). No other significant differences were seen for any other measures. These results suggest that a short period of strength training cessation can have positive effects on maximal strength expression, perhaps because of decreases in neuromuscular fatigue.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Adulto , Desempenho Atlético/fisiologia , Creatina Quinase/sangue , Estudos Cross-Over , Humanos , Masculino , Adulto Jovem
10.
Nanotechnology ; 28(12): 124004, 2017 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-28233763

RESUMO

Graphene's unique photoresponse has been largely used in a multitude of optoelectronics applications ranging from broadband photodetectors to wave-guide modulators. In this work we extend the range of applications to position-sensitive photodetectors (PSDs) using FeCl3-intercalated hexagonal domains of graphene grown by atmospheric pressure chemical vapour deposition (APCVD). The FeCl3-based chemical functionalisation of APCVD graphene crystals is affected by the presence of wrinkles and results in a non-uniform doping of the graphene layers. This doping profile creates multiple p-p+ photoactive junctions which show a linear and bipolar photoresponse with respect to the position of a focused light spot, which is ideal for the realization of a PSD. Our study paves the way towards the fabrication of flexible and transparent PSDs that could be embedded in smart textile and wearable electronics.

11.
J Sports Sci ; 35(10): 976-981, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27398685

RESUMO

This study compared the effects of six warm-up modalities on peak power output (PPO) during the high-pull exercise. Nine resistance-trained males completed six trials using different warm-ups: high-pull specific (HPS), cycle, whole body vibration (WBV), cycle+HPS, WBV+HPS and a control. Intramuscular temperature (Tm) was increased by 2°C using WBV or cycling. PPO, Tm and electromyography (EMG) were recorded during each trial. Two high-pulls were performed prior to and 3 min after participants completed the warm-up. The greatest increase in PPO occurred with HPS (232.8 ± 89.7 W, P < 0.001); however, this was not different to combined warm-ups (cycle+HPS 158.6 ± 121.1 W; WBV+HPS 177.3 ± 93.3 W, P = 1.00). These modalities increased PPO to a greater extent than those that did not involve HPS (all P < 0.05). HPS took the shortest time to complete, compared to the other conditions (P < 0.05). EMG did not differ from pre to post warm-up or between modalities in any of the muscles investigated. No change in Tm occurred in warm-ups that did not include cycling or WBV. These results suggest that a movement-specific warm-up improves performance more than temperature-related warm-ups. Therefore, mechanisms other than increased muscle temperature and activation may be important for improving short-term PPO.


Assuntos
Exercício de Aquecimento , Levantamento de Peso/fisiologia , Ciclismo/fisiologia , Temperatura Corporal , Estudos Cross-Over , Eletromiografia , Humanos , Masculino , Movimento/fisiologia , Músculo Esquelético/fisiologia , Vibração , Adulto Jovem
12.
Int J Sport Nutr Exerc Metab ; 27(2): 115-121, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27768503

RESUMO

This study was designed to investigate the effects of alcohol consumption on recovery of muscle force when consumed immediately postexercise in young females. Eight young women completed 300 maximal eccentric actions of the quadriceps femoris muscle on an isokinetic dynamometer on two occasions in a randomized, cross-over design after which an alcoholic beverage (0.88g ethanol/kg body weight) or an iso-caloric placebo was consumed. Maximal isokinetic (concentric and eccentric) torque and isometric tension produced across the knee were measured in both the exercised and control leg predamage, 36 hr post, and 60 hr post damage. Venous blood creatine kinase (CK) activity and muscle soreness ratings were taken before damage and once per day to 60 hr post damage. Significant differences were observed between the exercised and control leg for maximal concentric, and eccentric torque and isometric tension (p < .05). A near significant Treatment × Time interaction was observed for isometric tension (p = .077), but not for concentric or eccentric torque. No main effects of treatment (alcohol) or interactions with Time × Leg or Leg × Treatment were observed. Perceived muscle soreness during box stepping and squatting showed significant time effects (p < .05), and CK activity did not significantly change. Our results indicate that the consumption of 0.88g ethanol/kg body weight following eccentric exercise-induced muscle damage does not affect recovery in the days following damage in females.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Desempenho Atlético , Exercício Físico , Força Muscular , Mialgia/fisiopatologia , Esforço Físico , Músculo Quadríceps/fisiopatologia , Adulto , Bebidas Alcoólicas/efeitos adversos , Biomarcadores , Creatina Quinase/sangue , Estudos Cross-Over , Feminino , Humanos , Fadiga Muscular , Dinamômetro de Força Muscular , Mialgia/sangue , Mialgia/etiologia , Mialgia/prevenção & controle , Aptidão Física , Músculo Quadríceps/fisiologia , Índice de Gravidade de Doença , Fatores de Tempo , Adulto Jovem
13.
Epilepsia ; 57(7): 1130-8, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27221208

RESUMO

OBJECTIVES: An intravenous (IV) formulation of brivaracetam (BRV), a selective, high-affinity ligand for synaptic vesicle protein 2A, has been developed. We investigated the safety, tolerability, and pharmacokinetics of adjunctive IV BRV administered as a bolus or infusion to adults with epilepsy. METHODS: A phase III, multicenter, randomized, four-arm, parallel-group study (NCT01405508) of patients aged 16-70 years with focal or generalized epilepsy uncontrolled by 1-2 antiepileptic drugs was undertaken. The study comprised a 7-day baseline period, a 7-day double-blind run-in period (oral BRV 200 mg/day or placebo [PBO] twice daily [BID]), and 4.5-day open-label evaluation period (IV BRV 200 mg/day BID; 2-min bolus or 15-min infusion, total nine doses). Patients were randomized 1:1:1:1 PBO/BRV bolus; PBO/BRV infusion; BRV/BRV bolus; BRV/BRV infusion. Safety and tolerability were assessed using adverse events, electrocardiography, vital signs, and laboratory assessments. BRV plasma concentrations were measured before and 15 min after the first and last IV doses. RESULTS: Of the 105 patients randomized (53.3% women; 77.1% white; mean [standard deviation; SD] age 41.6 [12.2] years), 103 (98.1%) completed the study. Treatment-emergent adverse event (TEAE) incidence during IV BRV was similar whether IV BRV was initiated first (70.6%) or followed oral BRV (66.0%), and whether it was administered as a bolus (71.2%) or infusion (65.4%). Injection-related TEAEs were reported by 9.6% of patients following bolus and 11.5% following infusion. No serious TEAEs were reported. IV BRV plasma concentrations were higher after the first dose in the conversion groups than initiation groups, and slightly higher in the bolus arm than the infusion arm; concentrations were similar in all patients after the last IV dose. SIGNIFICANCE: IV BRV was generally well tolerated, with similar tolerability as a bolus or infusion and independent of de novo administration or as conversion from oral BRV tablets. IV BRV may be an option for patients who are unable to receive oral BRV.


Assuntos
Anticonvulsivantes/administração & dosagem , Epilepsia/tratamento farmacológico , Pirrolidinonas/administração & dosagem , Resultado do Tratamento , Adolescente , Adulto , Idoso , Anticonvulsivantes/sangue , Relação Dose-Resposta a Droga , Método Duplo-Cego , Epilepsia/sangue , Feminino , Humanos , Infusões Intravenosas/métodos , Masculino , Pessoa de Meia-Idade , Pirrolidinonas/sangue , Adulto Jovem
14.
Respiration ; 91(2): 101-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26761711

RESUMO

BACKGROUND: Pleural infection remains a significant cause of morbidity, mortality, prolonged hospital stay, and increased healthcare costs, despite advances in therapy. Twice daily intrapleural tissue plasminogen activator (tPA)/deoxyribonuclease (DNase) initiated at the time of diagnosis has been shown to significantly improve radiological outcomes and decrease the need for surgery. OBJECTIVES: To analyze our experience with once daily tPA/DNase for intrapleural sepsis. METHODS: Data derived from consecutive patients with empyema and complicated parapneumonic effusion who received once daily intrapleural tPA/DNase between January 2012 and August 2014 were reviewed. Measured outcomes included treatment success at 30 days, volume of pleural fluid drained, improvement in radiographic pleural opacity, length of hospital stay, need for surgery, and adverse events. RESULTS: 55 consecutive patients (33 male; mean age ± SD, 54.6 ± 16.1 years) were treated with once daily intrapleural tPA/DNase for 3 days. The majority of the patients (n = 51; 92.7%) were successfully managed without the need for surgical intervention. The mean change in pleural opacity measured on chest radiograph at day 7 was -28.8 ±17.6%. The median amount of fluid drained was 2,195 ml. No serious adverse events requiring discontinuation of intrapleural medications were observed. The most common complication was pain requiring escalating doses of analgesics (n = 8; 15%). Compliance with the protocol was excellent. CONCLUSION: Early administration of once daily intrapleural tPA/DNase for 3 days is safe, effective, and represents a viable option for the management of empyema and complicated parapneumonic effusion.


Assuntos
Desoxirribonucleases/administração & dosagem , Empiema Pleural/tratamento farmacológico , Derrame Pleural/tratamento farmacológico , Ativador de Plasminogênio Tecidual/administração & dosagem , Adulto , Idoso , Drenagem , Quimioterapia Combinada , Empiema Pleural/diagnóstico por imagem , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Derrame Pleural/diagnóstico por imagem , Radiografia Torácica , Estudos Retrospectivos , Resultado do Tratamento
15.
Eur J Appl Physiol ; 116(3): 583-92, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26718934

RESUMO

PURPOSE: Ammonia is used as a stimulant in strength based sports to increase arousal and offset fatigue however little is known about its physiological and performance effects. The purpose of this study was twofold (1) establish the physiological response to acute ammonia inhalation (2) determine whether the timing of the physiological response corresponds with a performance enhancement, if any. METHODS: Fifteen healthy males completed two trials. Trial one investigated the beat-to-beat middle cerebral artery blood flow velocity (MCAv), heart rate (HR) and mean arterial pressure (MAP) response to ammonia inhalation. During trial two, participants performed a maximal single mid-thigh pull (MTP) at various time points following ammonia inhalation in a randomised order: MTPs were conducted immediately, 15, 30 and 60 s following ammonia inhalation. A MTP with no ammonia inhalation served as the control. During this trial maximal MTP force, rate of force development (RFD) and electromyography (EMG) activity were recorded. RESULTS: MCAvmean increased and peaked on average by 6 cm s(-1) (P < 0.001), 9.4 ± 5.5 s following ammonia inhalation. Similarly, HR was increased by 6 ± 11 beats per minute 15 s following ammonia inhalation (P < 0.001). MAP remained unchanged following inhalation (P = 0.51). The use and timing of ammonia inhalation had no effect on maximal force, RFD or EMG (all P > 0.2) compared to control. CONCLUSIONS: MCAv was elevated despite no increase in MAP occurring; this is indicative of a cerebrovascular vasodilation. Despite the marked cerebrovascular and cardiovascular response to ammonia inhalation no ergogenic effect was observed during the MTP, irrespective of the timing of administration.


Assuntos
Amônia/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/farmacologia , Circulação Cerebrovascular/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Contração Muscular/efeitos dos fármacos , Adulto , Amônia/administração & dosagem , Estimulantes do Sistema Nervoso Central/administração & dosagem , Exercício Físico , Humanos , Inalação , Masculino
16.
J Strength Cond Res ; 30(7): 1796-804, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26670988

RESUMO

Pritchard, HJ, Tod, DA, Barnes, MJ, Keogh, JW, and McGuigan, MR. Tapering practices of New Zealand's elite raw powerlifters. J Strength Cond Res 30(7): 1796-1804, 2016-The major aim of this study was to determine tapering strategies of elite powerlifters. Eleven New Zealand powerlifters (28.4 ± 7.0 years, best Wilks score of 431.9 ± 43.9 points) classified as elite were interviewed, using semistructured interviews, about their tapering strategies. Interviews were transcribed verbatim and content analyzed. Total training volume peaked 5.2 ± 1.7 weeks from competition while average training intensity (of 1 repetition maximum) peaked 1.9 ± 0.8 weeks from competition. During tapering, volume was reduced by 58.9 ± 8.4% while intensity was maintained (or slightly reduced) and the final weight training session was performed 3.7 ± 1.6 days out from competition. Participants generally stated that tapering was performed to achieve full recovery; that accessory work was removed around 2 weeks out from competition; and deadlifting takes longer to recover from than other lifts. Typically participants stated that trial and error, and changes based on "feel" were the sources of tapering strategies; equipment used and movements performed during tapering are the same as in competition; nutrition was manipulated during the taper (for weight cutting or performance aims); and poor tapering occurred when too long (1 week or more) was taken off training. These results suggest that athletes may benefit from continuing to strength train before important events with reduced volume and maintained intensity. Only exercises that directly assist sports performance should remain in the strength program during tapering, to assist with reductions in fatigue while maintaining/improving strength expression and performance.


Assuntos
Treinamento Resistido/métodos , Levantamento de Peso/fisiologia , Adulto , Desempenho Atlético , Fadiga/prevenção & controle , Feminino , Humanos , Masculino , Força Muscular , Nova Zelândia , Adulto Jovem
17.
J Strength Cond Res ; 29(4): 1033-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25353078

RESUMO

Vibration exercise (VbX) has gained popularity as a warm-up modality to enhance performance in golf, baseball, and sprint cycling, but little is known about the efficacy of using VbX as a warm-up before resistance exercise, such as deadlifting. The aim of this study was to compare the effects of a deadlift (DL)-specific warm-up, VbX warm-up, and Control on DL power output (PO). The DL warm-up (DL-WU) included 10, 8, and 5 repetitions performed at 30, 40, and 50% 1-repetition maximum (1RM), respectively, where the number of repetitions was matched by body-weight squats performed with vibration and without vibration (Control). The warm-up conditions were randomized and performed at least 2 days apart. Peak power (PP), mean power, rate of force development (RFD), and electromyography (EMG) were measured during the concentric phase of 2 consecutive DLs (75% 1RM) at 30 seconds and 2:30 minutes after the warm-up conditions. There was no significant (p > 0.05) main effect or interaction effect between the DL-WU, VbX warm-up, and Control for PP, mean power, RFD, and EMG. Vibration exercise warm-up did not exhibit an ergogenic effect to potentiate muscle activity more than the specific DL-WU and Control. Therefore, DL PO is affected to a similar extent, irrespective of the type of stimuli, when the warm-up is not focused on raising muscle temperature.


Assuntos
Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Vibração , Exercício de Aquecimento/fisiologia , Levantamento de Peso/fisiologia , Adolescente , Adulto , Eletromiografia , Humanos , Masculino , Adulto Jovem
18.
Res Sports Med ; 23(2): 179-89, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25656945

RESUMO

The aim of this study was to determine the muscle activity and onset time of hip extensors during a closed kinetic chain exercise (deadlift) at sub-maximal loads of 30%, 40%, 50%, and 75% of one repetition maximum (1RM). Twelve healthy males with at least three years of resistance training experience volunteered for the study. Biceps femoris (BF) and gluteus maximus (GM) muscle activity, onset time, peak and mean power were measured during the concentric phase of the deadlift. There was no main effect (p > 0.05) or no interaction effect for the onset time in BF and GM and for each load BF and GM had similar muscle activity. Increasing the external load during deadlift had no adverse effect on the relative onset time and it did not promote BF onset to occur before GM onset, thus both muscles were simultaneously activated, which should not compromise a delay in GM.


Assuntos
Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Levantamento de Peso/fisiologia , Adolescente , Adulto , Quadril , Humanos , Masculino , Treinamento Resistido , Coxa da Perna , Fatores de Tempo , Adulto Jovem
19.
Biochim Biophys Acta ; 1831(8): 1311-21, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23665238

RESUMO

How dietary fatty acids are absorbed into the enterocyte and transported to the ER is not established. We tested the possibility that caveolin-1 containing lipid rafts and endocytic vesicles were involved. Apical brush border membranes took up 15% of albumin bound (3)H-oleate whereas brush border membranes from caveolin-1 KO mice took up only 1%. In brush border membranes, the (3)H-oleate was in the detergent resistant fraction of an OptiPrep gradient. On OptiPrep gradients of intestinal cytosol, we also found the (3)H-oleate in the detergent resistant fraction, separate from OptiPrep gradients spiked with (3)H-oleate or (3)H-triacylglycerol. Caveolin-1 immuno-depletion of cytosol removed 91% of absorbed (3)H-oleate whereas immuno-depletion using IgG, or anti-caveolin-2 or -3 or anti-clathrin antibodies removed 20%. Electron microscopy showed the presence of caveolin-1 containing vesicles in WT mouse cytosol that were 4 fold increased by feeding intestinal sacs 1mM oleate. No vesicles were seen in caveolin-1 KO mouse cytosol. Caveolin-1 KO mice gained less weight on a 23% fat diet and had increased fat in their stool compared to WT mice. We conclude that dietary fatty acids are absorbed by caveolae in enterocyte brush border membranes, are endocytosed, and transported in cytosol in caveolin-1 containing endocytic vesicles.


Assuntos
Caveolina 1/metabolismo , Gorduras na Dieta/metabolismo , Endocitose/fisiologia , Enterócitos/metabolismo , Absorção Intestinal/fisiologia , Ácido Oleico/metabolismo , Animais , Caveolina 1/genética , Citosol/metabolismo , Gorduras na Dieta/farmacologia , Enterócitos/citologia , Humanos , Microdomínios da Membrana/genética , Microdomínios da Membrana/metabolismo , Camundongos , Camundongos Knockout , Microvilosidades/genética , Microvilosidades/metabolismo , Ácido Oleico/farmacologia , Ratos
20.
Environ Sci Technol ; 48(3): 1819-27, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24422450

RESUMO

Environmental DNA (eDNA) surveillance holds great promise for improving species conservation and management. However, few studies have investigated eDNA dynamics under natural conditions, and interpretations of eDNA surveillance results are clouded by uncertainties about eDNA degradation. We conducted a literature review to assess current understanding of eDNA degradation in aquatic systems and an experiment exploring how environmental conditions can influence eDNA degradation. Previous studies have reported macrobial eDNA persistence ranging from less than 1 day to over 2 weeks, with no attempts to quantify factors affecting degradation. Using a SYBR Green quantitative PCR assay to observe Common Carp ( Cyprinus carpio ) eDNA degradation in laboratory mesocosms, our rate of Common Carp eDNA detection decreased over time. Common Carp eDNA concentration followed a pattern of exponential decay, and observed decay rates exceeded previously published values for aquatic macrobial eDNA. Contrary to our expectations, eDNA degradation rate declined as biochemical oxygen demand, chlorophyll, and total eDNA (i.e., from any organism) concentration increased. Our results help explain the widely divergent, previously published estimates for eDNA degradation. Measurements of local environmental conditions, consideration of environmental influence on eDNA detection, and quantification of local eDNA degradation rates will help interpret future eDNA surveillance results.


Assuntos
DNA/química , Água Doce/química , Animais , Carpas , Meio Ambiente , Reação em Cadeia da Polimerase
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