RESUMO
Congenital hypogonadotropic hypogonadism is a rare disorder characterised by impaired testosterone secretion since birth, and represents a valuable model for studying the effects of testosterone replacement therapy (TRT) in humans. This cross-sectional study aimed to investigate all health-related physical fitness (HRPF) components and quality of life in a series of eight men with hypogonadotropic hypogonadism under regular TRT. The study group was compared to a control group of 16 healthy subjects paired for age, body mass index and physical activity. Body composition, aerobic capacity, muscular strength and endurance, and joint flexibility were evaluated in two different 7-day interval time points, based on the pharmacokinetics of testosterone in the hypogonadal group. Quality of life was assessed by the WHOQOL-brief questionnaire. Both groups had similar performances in all HRPF components evaluated, independently of plasma testosterone levels (p > .05). Quality of life was also similar in the four domains analysed (p > .05). The results of this pilot study suggest that regular testosterone replacement was efficient in providing HRPF and quality of life in a series of congenitally hypogonadal men to levels like those observed in healthy men. In addition, acute fluctuations in plasma testosterone did not correlate with changes in muscle strength and endurance.
RESUMO
This study investigated the effects of 5 and 15°C cold-water immersion on recovery from exercise resulting in exercise-induced muscle damage. 42 college-aged men performed 5×20 drop-jumps and were randomly allocated into one of 3 groups: (1) 5°C; (2) 15°C; or (3) control. After exercise, individuals from the cold-water immersion groups had their lower limbs immerged in iced water for 20 min. Isometric knee extensor torque, countermovement jump, muscle soreness, and creatine kinase were measured before, immediately after, 24, 48, 72, 96 and 168 h post-exercise. There was no between-group difference in isometric strength recovery (p=0.73). However, countermovement jump recovered quicker in cold-water immersion groups compared to control group (p<0.05). Countermovement jump returned to baseline after 72 h in 15°C, 5°C group recovered after 96 h and control did not recovered at any time point measured. Also, creatine kinase returned to baseline at 72 h and remained stable for all remaining measurements for 15°C group, whereas remained elevated past 168 h in both 5°C and control groups. There was a trend toward lower muscle soreness (p=0.06) in 15°C group compared to control at 24 h post-exercise. The result suggests that cold-water immersion promote recovery of stretch-shortening cycle performance, but not influence the recovery of maximal contractile force. Immersion at warmer temperature may be more effective than colder temperatures promoting recovery from strenuous exercise.
Assuntos
Temperatura Baixa , Exercício Físico/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Adolescente , Creatina Quinase/metabolismo , Humanos , Imersão , Masculino , Contração Muscular/fisiologia , Mialgia/etiologia , Mialgia/terapia , Recuperação de Função Fisiológica/fisiologia , Temperatura , Fatores de Tempo , Água , Adulto JovemRESUMO
To evaluate the effects of a single session of partial-body cryotherapy (PBC) on muscle recovery, 26 young men performed a muscle-damaging protocol that consisted of five sets of 20 drop jumps with 2-min rest intervals between sets. After the exercise, the PBC group (n = 13) was exposed to 3 min of PBC at -110 °C, and the control group (n = 13) was exposed to 3 min at 21 °C. Anterior thigh muscle thickness, isometric peak torque, and muscle soreness of knee extensors were measured pre, post, 24, 48, 72, and 96 h following exercise. Peak torque did not return to baseline in control group (P < 0.05), whereas the PBC group recovered peak torques 96 h post exercise (P > 0.05). Peak torque was also higher after PBC at 72 and 96 h compared with control group (P < 0.05). Muscle thickness increased after 24 h in the control group (P < 0.05) and was significantly higher compared with the PBC group at 24 and 96 h (P < 0.05). Muscle soreness returned to baseline for the PBC group at 72 h compared with 96 h for controls. These results indicate that PBC after strenuous exercise may enhance recovery from muscle damage.
Assuntos
Crioterapia/métodos , Músculo Quadríceps/fisiopatologia , Recuperação de Função Fisiológica , Adolescente , Exercício Físico/fisiologia , Humanos , Contração Isométrica , Masculino , Mialgia/terapia , Músculo Quadríceps/diagnóstico por imagem , Músculo Quadríceps/patologia , Fatores de Tempo , Torque , Ultrassonografia , Adulto JovemRESUMO
The purpose of this study was to compare the acute effect of 2 different resting intervals (RI) between sets of isokinetic knee extension exercise on peak torque (PT) and total work (TW) in breast cancer survivors (BCS) and control group (CNT). 16 BCS (52±4 years) and 14 CNT (53±6 years) performed 3 sets of 10 unilateral isokinetic knee extension repetitions at 60°.s(- 1) on 2 separate days with 2 different RI between sets (1 and 2 min). There was a significant interaction between groups vs. exercise sets (p=0.03) and RI vs. exercise sets (p<0.001) for PT. PT was greater in CNT at 1(st) and 2(nd) sets compared to BCS group (CNT, 133.4±20.8 and BCS 107.6±19.9 Nm, p=0.012 and CNT, 118.9±19.6 and BCS, 97.1±15.9 Nm, p=0.045, respectively). The TW of the knee extensor was significant greater in CNT than BCS group for all 3 knee extension exercise sets. In conclusion, the present study suggests that Breast Cancer Survivors women may need a longer rest interval (longer than 2 min) to be able to fully recover during a 3 sets of isokinetic knee extension exercise training session.
Assuntos
Neoplasias da Mama/reabilitação , Exercício Físico/fisiologia , Articulação do Joelho/fisiologia , Descanso/fisiologia , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Força Muscular/fisiologia , Treinamento Resistido , Sobreviventes , Fatores de Tempo , TorqueRESUMO
Transcutaneous electrical nerve stimulation (TENS) increases peripheral blood flow by attenuation of the muscle metaboreflex, improving oxygen supply to working muscles. We tested the hypothesis that application of TENS at ganglion improves exercise performance. 11 subjects underwent constant-work rate tests (CWR) to the limit of tolerance (Tlim) while receiving TENS or placebo. Oxygen uptake (V.O2), carbon dioxide (V.CO2), minute ventilation (V.E), ventilatory equivalent (V.E/V.CO2), heart rate (HR) and oxygen pulse (V.O2/HR) were analyzed at isotime separated by percentile and Tlim. V.O2 was lower and V.CO2 was higher at 100% of isotime during TENS, while there were no differences in V.E and V.E/V.CO2. HR was lower during exercise with TENS, and V.O2/HR increased at peak exercise (17.96±1.9 vs. 20.38±1 ml/min/bpm, P<0.05). TENS increased mechanical efficiency at isotime and Tlim (4.10±0.50 vs. 3.39±0.52%, P<0.05 and 3.95±0.67 vs. 3.77±0.45%, P<0.05) and exercise tolerance compared to P-TENS (390±41 vs. 321±41 s; P<0.05). Our data shows that the application of TENS can potentially increase exercise tolerance and oxygen supply in healthy subjects.
Assuntos
Tolerância ao Exercício/fisiologia , Consumo de Oxigênio/fisiologia , Estimulação Elétrica Nervosa Transcutânea , Adulto , Estudos Cross-Over , Teste de Esforço , Voluntários Saudáveis , Frequência Cardíaca/fisiologia , Humanos , Masculino , Método Simples-CegoRESUMO
AIM: The purpose of the present study was to compare the effects of equal-volume resistance training (RT) performed once or twice a week on muscle mass and strength of the elbow flexors in untrained young men. METHODS: Thirty men (23 ± 3 years) without previous resistance training experience were divided into two groups: Group 1 (G1) trained each muscle group only once a week and group 2 (G2) trained each muscle twice a week during 10 weeks. Baseline and 10 weeks post-test elbow flexors muscle thickness (MT) were measured using a B-Mode ultrasound. Peak torque (PT) was assessed by an isokinetic dynamometer before and after the training program. RESULTS: Elbow flexors MT increased significantly (P<0.05) from 31.70 ± 3.31 to 33.43 ± 3.46 mm in G1, and from 32.78 ± 4.03 to 35.09 ± 3.55 mm in G2. Elbow flexors PT also increased (P<0.05) from 50.77 ± 9.26 to 54.15 ± 10.79 N.m in G1, and from 48.99 ± 11.52 to 55.29 ± 10.24 N.m in G2. The results of ANOVA did not reveal group by time interactions for any variable, indicating no difference between groups for the changes in MT or PT. CONCLUSION: The results from the present study suggest that untrained men experience similar gains in muscle mass and strength with equal volume RT performed one or two days per week.
Assuntos
Força Muscular , Músculo Esquelético/diagnóstico por imagem , Treinamento Resistido/métodos , Extremidade Superior/diagnóstico por imagem , Humanos , Masculino , Ultrassonografia , Adulto JovemRESUMO
It has been demonstrated that body cooling may decrease neuromuscular performance. However, the effect of a single session of whole body cryotherapy (-110°C) on neuromuscular performance has not been well documented. Thus, the aim of this study was to evaluate the effects of a single exposure of WBC on elbow flexor neuromuscular performance. Thirteen physically active, healthy young men (age=27.9±4.2 years, mass=79.4±9.7 kg, height=176.7±5.2 cm) were randomly exposed to 2 different experimental conditions separated by a minimum of 72 h: 1) whole body cryotherapy- 3 min at -110°C; 2) control- 3 min at 21°C. All subjects were tested for maximal isokinetic elbow flexion at 60°.s(-1) 30 min before and 10 min after each condition. There were no significant differences in peak torque, average power, total work or muscle activity between conditions. Peak torque was lower at post-test compared to pre-test in both conditions (F=6.58, p=0.025). However, there were no differences between pre-test and post-test for any other variables. These results indicate that strength specialists, athletic trainers and physical therapists might utilize whole body cryotherapy before training or rehabilitation without compromising neuromuscular performance of the elbow flexors.
Assuntos
Crioterapia/métodos , Cotovelo/fisiologia , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Adulto , Eletromiografia , Humanos , Masculino , Força Muscular/fisiologia , Dinamômetro de Força Muscular , Músculo Esquelético/inervação , TorqueRESUMO
The aim was to investigate the effects of the intra-session exercise order during water-based concurrent training on the neuromuscular adaptations in young women. 26 women (25.1±2.9 years) were placed into 2 groups: resistance prior to (RA) or after (AR) aerobic training. Subjects performed resistance (sets at maximal effort) and aerobic training (exercises at heart rate corresponding to the second ventilatory threshold) twice a week over 12 weeks, performing both exercise types in the same training session. Upper (elbow flexion) and lower-body (knee extension) one-repetition maximum test (1RM) and peak torque (PT) were evaluated. The muscle thickness (MT) of upper (sum of MT of biceps brachii and brachialis) and lower-body (sum of MT of vastus lateralis, vastus medialis, vastus intermedius, and rectus femoris) was determined by ultrasonography. Moreover, the maximal electromyographic activity (EMG) of upper (biceps brachii) and lower-body (sum of EMG of vastus lateralis and rectus femoris) was measured. Both RA and AR groups increased the upper and lower-body 1RM and PT, while the lower-body 1RM increases observed in the RA was greater than AR (43.58±14.00 vs. 27.01±18.05%). RA and AR showed MT increases in all muscles evaluated, while the lower-body MT increases observed in the RA were also greater than AR (10.24±3.11 vs. 5.76±1.88%). There were increases in the maximal EMG of upper and lower-body in both RA and AR, with no differences between groups. Performing resistance prior to aerobic exercise during water-based concurrent training seems to optimize the lower-body strength and hypertrophy.
Assuntos
Adaptação Fisiológica/fisiologia , Exercício Físico/fisiologia , Músculo Esquelético/fisiologia , Água , Adulto , Eletromiografia , Feminino , Voluntários Saudáveis , Humanos , Contração Isométrica/fisiologia , Perna (Membro)/fisiologia , Força Muscular/fisiologia , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/crescimento & desenvolvimento , Consumo de Oxigênio , Treinamento Resistido/métodos , Torque , UltrassonografiaRESUMO
The aim of this study was to evaluate the effects of a single partial-body cryotherapy bout between training sessions on strength recovery. 12 young men (23.9±5.9 years) were randomly exposed to 2 different conditions separated by 7 days: 1) Partial-body cryotherapy (subjects were exposed to 3 min of partial-body cryotherapy at - 110 °C between 2 high-intensity training sessions); 2) Control (subjects were not exposed to partial-body cryotherapy between 2 high-intensity training sessions). Subjects were exposed to partial-body cryotherapy after the first training session. The 2 knee extension high-intensity training sessions were separated by a 40-min rest interval. Knee extension training consisted of 6 sets of 10 repetitions at 60°.s(-1) for concentric actions and 6 sets of 10 at 180.s(-1) for eccentric actions. The decrease in eccentric peak torque and total work was significantly (p<0.05) less after partial-body cryotherapy (5.6 and 2%, respectively) when compared to control (16 and 11.6%, respectively). However, the decrease in concentric peak torque and total work was not different (p>0.05) between partial-body cryotherapy (9.4 and 6.5%, respectively) and control (7.5 and 5.2%, respectively). These results indicate that the use of partial-body cryotherapy between-training sessions can enhance eccentric muscle performance recovery.
Assuntos
Crioterapia , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido , Adulto , Humanos , Joelho/fisiologia , Masculino , Torque , Adulto JovemRESUMO
This investigation was designed to evaluate responses of blood pressure (BP) following an acute resistance exercise (RE) session. Middle-aged women (N=13) who were classified as overweight (N=8) or obese (N=5) according to body mass index (BMI) participated in the investigation. Participants were randomly submitted to a control session (30-min seated rest) and a exercise session (3 sets, 10 repetitions at 60% 1RM of exercises for the upper and lower body) with systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) obtained at rest and 10, 20, 30, 40, 50, and 60-min following exercise, and through 24 h. Acute RE decreased SBP at 10, 30, and 40-min compared with pre-exercise and control (P<0.05). DBP decreased at 10 and 40-min post-exercise compared with the control trial (P<0.05). Both SBP and DBP decreased in the nighttime period (-4.2 mmHg and -4.1 mmHg, respectively) and in the overall 24 h period (-3.6 mmHg and -4.5 mmHg, respectively) following the acute RE session when compared with the control trial. These findings indicate important benefits of acute RE on BP circadian rhythm, particularly at night as well as in the morning, which are critical periods associated with increased risk for cardiovascular events.
Assuntos
Pressão Sanguínea/fisiologia , Sobrepeso/terapia , Treinamento Resistido , Adulto , Análise de Variância , Monitorização Ambulatorial da Pressão Arterial , Ritmo Circadiano , Feminino , Humanos , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Obesidade/terapia , Sobrepeso/fisiopatologia , Resultado do TratamentoRESUMO
The objective of the present study was to evaluate and compare the neuromuscular, morphological and functional adaptations of older women subjected to 3 different types of strength training. 58, healthy women (67 ± 5 year) were randomized to experimental (EG, n=41) and control groups (CG, n=17) during the first 6 weeks when the EG group performed traditional resistance exercise for the lower extremity. Afterwards, EG was divided into three specific strength training groups; a traditional group (TG, n=14), a power group (PG, n=13) that performed the concentric phase of contraction at high speed and a rapid strength group (RG, n=14) that performed a lateral box jump exercise emphasizing the stretch-shortening-cycle (SSC). Subjects trained 2 days per week through the entire 12 weeks. Following 6 weeks of generalized strength training, significant improvements occurred in EG for knee extension one-repetition (1RM) maximum strength (+19%), knee extensor muscle thickness (MT, +15%), maximal muscle activation (+44% average) and onset latency ( -31% average) for vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) compared to CG (p<0.05). Following 6 more weeks of specific strength training, the 1RM increased significantly and similarly between groups (average of +21%), as did muscle thickness of the VL (+25%), and activation of VL (+44%) and VM (+26%). The onset latency of RF (TG=285 ± 109 ms, PG=252 ± 76 ms, RG=203 ± 43 ms), reaction time (TG=366 ± 99 ms, PG=274 ± 76 ms, RG=201 ± 41 ms), 30-s chair stand (TG=18 ± 3, PG=18 ± 1, RG=21 ± 2) and counter movement jump (TG=8 ± 2 cm, PG=10 ± 3 cm, RG=13 ± 2 cm) was significantly improved only in RG (p<0.05). At the end of training, the rate of force development (RFD) over 150 ms (TG=2.3 ± 9.8 N·s(-1), PG=3.3 ± 3.2 N·s(-1), RG=3.8 ± 6.8 N·s(-1), CG=2.3 ± 7.0 N·s(-1)) was significantly greater in RG and PG than in TG and CG (p<0.05). In conclusion, rapid strength training is more effective for the development of rapid force production of muscle than other specific types of strength training and by consequence, better develops the functional capabilities of older women.
Assuntos
Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Força Muscular/fisiologiaRESUMO
The purpose of this study was to examine the effect of two between set rest intervals (RI) on isokinetic knee extension peak torque (PT) produced by sedentary women and men. Seventeen young women (27.18 ± 4.05 yrs) and 16 young men (26.75 ± 4.73 yrs) performed 3 sets of 10 unilateral isokinetic knee extension at 60° and 180°/s. The RI between sets was 60 and 120 s, counterbalanced across 2 testing days. Statistical evaluation of the data was performed using a 3-way mixed factor ANOVA (gender x rest interval x sets). Males and females exhibited decreases (p<0.05) in PT with 120 s RI at 60°/s. There was no significant decline in PT in the female group during both RI at 180°/s. Men showed a significant decrease in PT only with 60 s RI. Young women and men require more than 120 s of RI to recover full PT at 60°/s. However, full quadriceps's muscle strength recovery can be attained with a 60 and 120 s at 180°/s in women, but in men only with a 120 s at the same velocity.
Assuntos
Articulação do Joelho/fisiologia , Contração Muscular/fisiologia , Fadiga Muscular/fisiologia , Músculo Esquelético/fisiologia , Adulto , Análise de Variância , Feminino , Humanos , Contração Isométrica/fisiologia , Masculino , Fatores Sexuais , Fatores de Tempo , Torque , Adulto JovemRESUMO
The purpose of this study was to compare the effect of two different rest intervals between sets of isokinetic knee extension exercise on peak torque (PT), and Total Work (TW) between untrained younger and older men. Seventeen young men (24.22+/-2.58 yrs) and 20 older men (66.85+/-4.02 yrs) performed 3 sets of 10 unilateral isokinetic knee extension repetitions at 60 degrees /s. The rest intervals between sets were 1 and 2 min. There was a significant decline in PT when 1 and 2 min rest intervals were used for young men, but not when a 2 min rest interval was applied for old men. There was also a significant decline in TW among the 3 sets when 1 and 2 min rest intervals were applied for young men, whereas the decline in TW in older men occurred only between the 2(nd) and 3(rd) sets. PT and TW in the 3(rd) set were significant greater following a 2 min rest interval than a 1 min rest in both young and older men. The present study indicated that non-resistance trained young men may require longer rest interval to recover full PT and TW when compared to older men.
Assuntos
Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido , Descanso/fisiologia , Adulto , Fatores Etários , Idoso , Humanos , Joelho , Masculino , Pessoa de Meia-Idade , Fadiga Muscular/fisiologia , Fatores de Tempo , Torque , Adulto JovemRESUMO
The present study aimed at comparing the effects of traditional resistance training (TRT) and power training (PT) in inducing muscle hypertrophy in older men. Twenty older men (aged between 69 and 76 years) were divided in two groups: TRT training (n=9) and PT training (n=11). The volunteers trained twice a week, during 10 weeks. Both groups performed an equal work output and the same exercises with loads between 40% and 60% of 1 RM. Three sets of eight repetitions of each exercise were performed with rest intervals of 90 s between sets. Muscle thickness was measured by ultrasound at the biceps brachii (BIC) and rectus femoris (RF), using a 12 MHz high resolution scanning probe. An ANCOVA was used to compare post training muscle thickness values between TRT and PT, using baseline values as covariates. According to the results, RF muscle thickness increased only in PT, while BIC muscle thickness increased in both groups, but with larger increases in PT. In conclusion, ten weeks of PT induced muscle hypertrophy of the upper and lower limb muscles in older men. PT training may yield better results in muscle hypertrophy when compared with TRT.
Assuntos
Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Treinamento Resistido , Idoso , Envelhecimento/fisiologia , Análise de Variância , Humanos , Hipertrofia , Masculino , Músculo Esquelético/diagnóstico por imagem , Aptidão Física/fisiologia , Fatores de Tempo , UltrassonografiaRESUMO
A commercial aperitif containing E110 and E122 dyes is exposed to photo-irradiation in solar box under conditions chosen to simulate sun light irradiation. After 16 days of irradiation the red-coloured aperitif assumes a very pale yellow colour. HPLC-diode array-MS/MS analysis evidences the presence in the commercial aperitif of some impurities with naphthalene-based structures. The structures for the photodegradation products are proposed.
Assuntos
Compostos Azo/química , Bebidas/análise , Cromatografia Líquida de Alta Pressão/métodos , Corantes/química , Espectrometria de Massas em Tandem/métodos , Bebidas/efeitos da radiação , Fotoquímica , Luz SolarRESUMO
An HILIC-PI APCI MS/MS method is developed for the determination of seven biogenic amines (cadaverine, histamine, putrescine, spermidine, spermine, tryptamine and tyramine) in cheese. Their presence and relative amounts give useful information about freshness, level of maturing, quality of storage and cheese typicization. The major drawback in the analysis is represented by the relevant matrix effect and the general unbalanced concentrations of the different amines in cheese. The method proposed represents an improvement with respect to an HPLC-MS/MS method already developed in this laboratory. The new method permits better sensitivities it makes use of a Waters Atlantis HILIC (150.0 mm x 2.1 mm i.d., 3 microm) stationary phase and of a mobile phase of acetonitrile and ammonium formate 50.0 mM in ultrapure water brought to pH 4.00 for formic acid, flowing under gradient conditions. The chromatographic system is interfaced with a 3200QTrap LC-MS/MS system (Applied Biosystem, Foster City, CA, USA) by a Turbo V interface equipped with Heated Nebuliser (APCI) and Turbo Ion Spray (TIS) probes. LOQ values lower than 10 microg L(-1) are obtained. The method is applied in the analysis of Castelmagno cheese.
Assuntos
Aminas Biogênicas/análise , Queijo/análise , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Espectrometria de Massas em Tandem , Aminas Biogênicas/isolamento & purificaçãoRESUMO
BACKGROUND: This study aimed to investigate the effects of different intra-session exercise orders during concurrent training (CT) on endurance performance in elderly men, as well as to verify its influence on individual responses in endurance performance. DESIGN: Twenty-five healthy elderly men (64.7 ± 4.1 years) were placed into two groups: strength training prior to endurance training (SE, n=13), and one in the reverse order (ES, n=12). CT was performed three times a week during 12 weeks. Before and after training, peak oxygen uptake (VO2peak), maximal workload (Wmax), absolute and relative cycling economy at 25, 50, 75 and 100 W (i.e., average VO2 at different stages) were assessed. RESULTS: Similar increases in VO2peak were observed in the SE and ES groups (SE: 8.1 ± 9.9%; ES: 9.3 ± 9.8%; P<0.001), as well as in Wmax (SE: 19.9 ± 19.3%; ES: 24.1 ± 24.0%; P<0.001). Moreover, significant reductions were observed in the absolute VO2 at 100 W (P<0.05) in the SE and ES groups. No difference between groups was observed. In the ES group, one subject did not respond positively in terms of both VO2max and Wmax, whereas 4 subjects did not respond positively in terms of both VO2max and Wmax in SE group. CONCLUSIONS: CT improved maximal and submaximal endurance performance in elderly men, independent of intra-session exercise order. However, it seems that the ES order elicited more individual responsiveness in terms of maximal endurance performance than SE order.
Assuntos
Aptidão Cardiorrespiratória/fisiologia , Resistência Física/fisiologia , Treinamento Resistido/métodos , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
A practical method to determine the heating and cooling curves of x-ray tube assemblies with rotating anode x-ray tube is proposed. Available procedures to obtain these curves as described in the literature are performed during operation of the equipment, and the precision of the method depends on the knowledge of the total energy applied in the system. In the present work we describe procedures which use a calorimetric system and do not require the operation of the x-ray equipment. The method was applied successfully to a x-ray tube assembly that was under test in our laboratory.
Assuntos
Calorimetria/instrumentação , Temperatura Baixa , Temperatura Alta , Radiografia/instrumentação , Calibragem , Calorimetria/métodos , Desenho de Equipamento , Calefação , Humanos , Modelos Estatísticos , Teoria Quântica , Doses de Radiação , Intensificação de Imagem Radiográfica , Radiografia/métodos , Tecnologia Radiológica , Temperatura , Raios XRESUMO
Fresh vegetables and their ready-to-eat (RTE) salads have become increasingly recognized as potential vehicles for foodborne diseases. The EU Reg. 1441/2007 establishes microbiological criteria for bacterial pathogens for products placed on the market during their shelf-life (i.e. Salmonella spp., Listeria monocytogenes) for pre-cut fruits and vegetables (RTE) whilst it does not address the problem of contamination by enteric viruses. In this study we investigated the contamination by hepatitis A virus (HAV), hepatitis E virus (HEV) and norovirus (NoV) in 911 ready-to-eat vegetable samples taken from products at retail in Apulia and in Lombardia. The vegetable samples were tested using validated real-time PCR (RT-qPCR) assays, ISO standardized virological methods and ISO culturing methods for bacteriological analysis. The total prevalence of HAV and HEV was 1.9% (18/911) and 0.6% (6/911), respectively. None of the samples analysed in this study was positive for NoV, Salmonella spp. or Listeria monocytogenes. The detection of HAV and HEV in RTE salads highlights a risk to consumers and the need to improve production hygiene. Appropriate implementation of hygiene procedures is required at all the steps of the RTE vegetable production chain and this should include monitoring of emerging viral pathogens.
Assuntos
Contaminação de Alimentos/análise , Vírus da Hepatite A/isolamento & purificação , Vírus da Hepatite E/isolamento & purificação , Norovirus/isolamento & purificação , Verduras/virologia , Microbiologia de Alimentos/métodos , Inocuidade dos Alimentos/métodos , Doenças Transmitidas por Alimentos/virologia , Humanos , Itália , Listeria monocytogenes/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Salmonella/isolamento & purificaçãoRESUMO
Hepatitis A virus (HAV) was detected in a batch of imported non-packaged frozen redcurrants purchased in a Bari grocery. Sequence and phylogenetic analysis showed the HAV strain clustered tightly with the HAV strain from the 2013 Italian epidemic, providing additional evidence that frozen redcurrants were the main vehicle of the HAV outbreak.