Effects of intermittent pneumatic compression on the recovery of cardiovascular parameters after repeated sprint exercise.

PURPOSE: Intermittent pneumatic compression (IPC) applies gradual pressure to facilitate lymph and blood flow movement to reduce exercise-induced tissue fluid accumulation and plasma volume loss. This study aimed to evaluate the cardiovascular system response during the recovery with IPC compared with passive recovery (Sham). METHODS: Sixteen volunteers (7 females and 9 males) executed a cycling-based exhausting sprint interval exercise (8 × 20 s all out), followed by a 30-min IPC or Sham condition. Participants performed two trials in a randomised, counterbalanced, and crossover design. Several cardiovascular parameters (blood pressure, heart function, and peripheral vascular resistance) were recorded at baseline (5'), through the recovery protocol (30'), and afterwards (5'). RESULTS: The use of IPC during the recovery phase led to a faster recovery, stated in relative values to pre-exercise, in mean blood pressure (102.5 ± 19.3% vs. 92.7 ± 12.5%; P < 0.001), and cardiac output (139.8 ± 30.0% vs. 146.2 ± 40.2%; P < 0.05) in comparison to Sham condition. Furthermore, during the IPC-based recovery, there was a slower recovery in cardiac pressure change over time (92.5 ± 25.8% vs. 100.5 ± 48.9%; P < 0.05), and a faster return to pre-exercise values in the peripheral vascular resistance (75.2 ± 25.5% vs. 64.8 ± 17.4%; P < 0.001) compared to Sham. CONCLUSION: The application of IPC after high-intensity exercise promotes the recovery of the cardiovascular system, reducing cardiovascular strain. Future investigations should consider the effects on the sympathetic-parasympathetic balance, such as heart rate variability, to assess further bonds between the use of IPC and autonomous control.

Association of Physical Fitness and Anthropometric Parameters With Lung Function in 7-Year-Old Children.

PURPOSE: Associations between health-related parameters and lung function remain unclear in childhood. The study aims to evaluate the relationship between physical fitness and anthropometric parameters with the lung function of healthy scholar-aged children. METHOD: A total of 418 children aged 7 years old participated in this study. The associations of physical fitness (handgrip strength, standing broad jump, and 800-m run) and anthropometric (waist circumference and body mass index) parameters with lung function (forced vital capacity and forced expiratory volume in 1 s) were analyzed using a mixed-linear regression model. RESULTS: Girls had significantly lower forced vital capacity values (P = .006) and physical fitness (P < .030) compared to boys. On mixed-linear regression analyses, waist circumference (P = .003) was independently associated with forced vital capacity, explaining 34.6% of its variance, while handgrip strength (P = .042) and waist circumference (P = .010) were independently associated with forced expiratory volume in 1 second, accounting together for 26.5% of its variance in 7-year-old healthy children. CONCLUSIONS: Handgrip strength and waist circumference were associated with lung function in healthy children highlighting the influence of upper body muscular strength and trunk dimension on lung function. Our results corroborate the need to promote physical fitness during childhood to protect against lung complications in later on in life.

Sexual Dimorphism in Brown Adipose Tissue Activation and White Adipose Tissue Browning.

The present narrative review gathers the studies reported so far, addressing sex differences in the effects of cold exposure, feeding pattern and age on brown adipose tissue (BAT) thermogenesis and white adipose tissue (WAT) browning. In rodents, when exposed to decreasing temperatures, females activate thermogenesis earlier. Results obtained in humans go in the same line, although they do not provide results as solid as those obtained in rodents. Regarding the effects of overfeeding, interesting sex differences on BAT thermogenic capacity have been reported, and the greater or lower sensitivity of each sex to this dietary situation seems to be dependent on the type of feeding. In the case of energy restriction, females are more sensitive than males. In addition, sex differences have also been observed in thermogenesis changes induced by phenolic compound administration. During sexual development, an increase in BAT mass and BAT activity takes place. This phenomenon is greater in boys than in girls, probably due to its relation to muscle-mass growth. The opposite situation takes place during ageing, a lifespan period where thermogenic capacity declines, this being more acute in men than in women. Finally, the vast majority of the studies have reported a higher susceptibility to developing WAT browning amongst females. The scarcity of results highlights the need for further studies devoted to analysing this issue, in order to provide valuable information for a more personalised approach.

Changes in Lung Diffusing Capacity of Elite Artistic Swimmers During Training.

Artistic swimmers (AS) are exposed to repeated apnoeas in the aquatic environment during high intensity exercise provoking specific physiological responses to training, apnoea, and immersion. This study aimed to evaluate the changes in lung diffusing capacity in AS pre-, mid- and post-training in a combined session of apnoeic swimming, figures and choreography. Eleven elite female AS from the Spanish national team were the study's participants. The single-breath method was used to measure lung diffusing capacity for carbon monoxide (DLCO) and one-way repeated measures ANOVA was utilized to evaluate the statistical analysis. Basal values of DLCO were higher than normal for their age and height (33.6±4.9 mL·min-1·mmHg-1; 139±19%) and there were a significant interaction between DLCO and AS training (ŋ2 p=0.547). After the apnoeic swimming (mid-training) there was an increase in DLCO from basal to 36.7±7.3 mL·min-1·mmHg-1 (p=0.021), and after the figures and choreography (post-training) there was a decrease compared to mid-training (32.3±4.6 mL·min-1·mmHg-1, p=0.013). Lung diffusing capacity changes occur during AS training, including a large increase after apnoeic swimming. There were no differences in lung diffusing capacity from pre- to post-training, although large inter-individual variability was observed.

Performance Comparison of Three Fibre-Based Reflective Optical Sensors for Aero Engine Monitorization.

Among the different available optical technologies, fibre bundle-based reflective optical sensors represent an interesting alternative for parameter monitorization in aero engines. Tip clearance is one of the parameters of great concern for engine designers and engineers. In the framework of this optical technology, three fibre-based reflective optical sensors have been compared. Two of them are custom designed and based on the same geometrical fibre arrangement, whereas the third one is commercially available and relies on a different geometrical arrangement of the fibres. Their performance has been compared in clearance measurements carried out during an experimental program followed at a transonic wind tunnel for aero turbines. The custom-designed solution that operates in the most sensitive part of its response curve proved to be by far the most reliable tool for clearance measurements. Its high resolution opens up the possibility to detect small blade features such as cracks, reflectivity changes, etc. that otherwise could not be tracked. These results show that the detection of unexpected features on blade tips may have an important effect on how the clearance is calculated, ultimately giving rise to corrective actions.

Design, Fabrication and Testing of a High-Sensitive Fibre Sensor for Tip Clearance Measurements.

A highly sensitive fibre bundle-based reflective optical sensor has been designed and fabricated for Tip Clearance measurements in a turbine rig. The sensor offers high spatial and temporal resolution. The sensor probe consists of a single-mode transmitting fibre and two concentric rings of receiving multimode fibres that collect reflected light in a differential detection gain configuration, yielding a highly linear calibration curve for distance measurements. The clearance measurement range is approximately 2 mm around the central point fixed at 3.2 mm from the probe tip, and the sensitivity of the probe is 61.73 mm-1. The fibre bundle has been designed to ensure that the distance security specifications required for the experimental program of the turbine are met. The optical sensor has operated under demanding conditions set by the blade and casing design. The experimental results obtained so far are promising and lead us to think that the optical sensor has great potential for online clearance measurements with high precision.

Optical Tip Clearance Measurements as a Tool for Rotating Disk Characterization.

An experimental investigation on the vibrational behavior of a rotating disk by means of three optical fiber sensors is presented. The disk, which is a scale model of the real disk of an aircraft engine, was assembled in a wind tunnel in order to simulate real operation conditions. The pressure difference between the upstream and downstream sides of the disk causes an airflow that might force the disk to vibrate. To characterize this vibration, a set of parameters was determined by measuring the tip clearance of the disk: the amplitude, the frequency and the number of nodal diameters in the disk. All this information allowed the design of an upgraded prototype of the disk, whose performance was also characterized by the same method. An optical system was employed for the measurements, in combination with a strain gauge mounted on the disk surface, which served to confirm the results obtained. The data of the strain gauge coincided closely with those provided by the optical fiber sensors, thus demonstrating the suitability of this innovative technique to evaluate the vibrational behavior of rotating disks.

Tip-Clearance Measurement in the First Stage of the Compressor of an Aircraft Engine.

In this article, we report the design of a reflective intensity-modulated optical fiber sensor for blade tip-clearance measurement, and the experimental results for the first stage of a compressor of an aircraft engine operating in real conditions. The tests were performed in a ground test cell, where the engine completed four cycles from idling state to takeoff and back to idling state. During these tests, the rotational speed of the compressor ranged between 7000 and 15,600 rpm. The main component of the sensor is a tetrafurcated bundle of optical fibers, with which the resulting precision of the experimental measurements was 12 µm for a measurement range from 2 to 4 mm. To get this precision the effect of temperature on the optoelectronic components of the sensor was compensated by calibrating the sensor in a climate chamber. A custom-designed MATLAB program was employed to simulate the behavior of the sensor prior to its manufacture.

Discovery of copy number variants by multiplex amplifiable probe hybridization (MAPH) in candidate pigmentation genes.

BACKGROUND: Copy Number Variants (CNVs) contribute to a large fraction of genetic diversity and some of them have been reported to offer an evolutionary advantage. AIM: To identify CNVs in pigmentary loci that could contribute to human skin pigmentation diversity. SUBJECTS AND METHODS: This study assessed the existence of CNVs in every exon of candidate genes: TYR, TYRP1, DCT, MC1R and SLC24A5, using the Multiplex Amplifiable Probe Hybridization technique (MAPH). This study analysed a total of 99 DNA samples of unrelated individuals from different populations. Validation and further analysis in a larger Spanish sample were performed by RT-qPCR. RESULTS: Five CNVs were identified by MAPH: DCT exons 4 and 8, TYR exon 1 and SLC24A5 exons 1 and 4. Real-time quantitative PCR (RT-qPCR) confirmed the CNV in exon 1 of SLC24A5. This study further analysed the 5' promoter region of SLC24A5 and found another CNV in this region. However, no association was found between the CNV and the degree of pigmentation. CONCLUSION: Although the functional role of these structural variants in pigmentation should be the subject of future work, the results emphasize the need to consider all classes of variation (both SNPs and CNVs) when exploring the genetics of skin pigmentation.

Optical Fiber Sensors for Aircraft Structural Health Monitoring.

Aircraft structures require periodic and scheduled inspection and maintenance operations due to their special operating conditions and the principles of design employed to develop them. Therefore, structural health monitoring has a great potential to reduce the costs related to these operations. Optical fiber sensors applied to the monitoring of aircraft structures provide some advantages over traditional sensors. Several practical applications for structures and engines we have been working on are reported in this article. Fiber Bragg gratings have been analyzed in detail, because they have proved to constitute the most promising technology in this field, and two different alternatives for strain measurements are also described. With regard to engine condition evaluation, we present some results obtained with a reflected intensity-modulated optical fiber sensor for tip clearance and tip timing measurements in a turbine assembled in a wind tunnel.

Unveiling the crystal and magnetic texture of iron oxide nanoflowers.

Iron oxide nanoflowers (IONF) are densely packed multi-core aggregates known for their high saturation magnetization and initial susceptibility, as well as low remanence and coercive field. This study reports on how the local magnetic texture originating at the crystalline correlations among the cores determines the special magnetic properties of individual IONF over a wide size range from 40 to 400 nm. Regardless of this significant size variation in the aggregates, all samples exhibit a consistent crystalline correlation that extends well beyond the IONF cores. Furthermore, a nearly zero remnant magnetization, together with the presence of a persistently blocked state, and almost temperature-independent field-cooled magnetization, support the existence of a 3D magnetic texture throughout the IONF. This is confirmed by magnetic transmission X-ray microscopy images of tens of individual IONF, showing, in all cases, a nearly demagnetized state caused by the vorticity of the magnetic texture. Micromagnetic simulations agree well with these experimental findings, showing that the interplay between the inter-core direct exchange coupling and the demagnetizing field is responsible for the highly vortex-like spin configuration that stabilizes at low magnetic fields and appears to have partial topological protection. Overall, this comprehensive study provides valuable insights into the impact of crystalline texture on the magnetic properties of IONF over a wide size range, offering a deeper understanding of their potential applications in fields such as biomedicine and water remediation.

Usefulness of Opuntia spp. on the Management of Obesity and Its Metabolic Co-Morbidities.

The plants of the Opuntia genus mainly grow in arid and semi-arid climates. Although the highest variety of wild species is found in Mexico, Opuntia spp. is widely distributed throughout the world. Extracts of these cacti have been described as important sources of bioactive substances that can have beneficial properties for the prevention and treatment of certain metabolic disorders. The objective of this review is to summarise the presently available knowledge regarding Opuntia ficus-indica (nopal or prickly pear), and some other species (O. streptacantha and O. robusta) on obesity and several metabolic complications. Current data show that Opuntia ficus-indica products used in preclinical studies have a significant capacity to prevent, at least partially, obesity and certain derived co-morbidities. On this subject, the potential beneficial effects of Opuntia are related to a reduction in oxidative stress and inflammation markers. Nevertheless, clinical studies have evidenced that the effects are highly contingent upon the experimental design. Moreover, the bioactive compound composition of nopal extracts has not been reported. As a result, there is a lack of information to elucidate the mechanisms of action responsible for the observed effects. Accordingly, further studies are needed to demonstrate whether Opuntia products can represent an effective tool to prevent and/or manage body weight and some metabolic disorders.

An optical fiber bundle sensor for tip clearance and tip timing measurements in a turbine rig.

When it comes to measuring blade-tip clearance or blade-tip timing in turbines, reflective intensity-modulated optical fiber sensors overcome several traditional limitations of capacitive, inductive or discharging probe sensors. This paper presents the signals and results corresponding to the third stage of a multistage turbine rig, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on the turbine casing. To eliminate the influence of light source intensity variations and blade surface reflectivity, the sensing principle is based on the quotient of the voltages obtained from the two receiving bundle legs. A discrepancy lower than 3% with respect to a commercial sensor was observed in tip clearance measurements. Regarding tip timing measurements, the travel wave spectrum was obtained, which provides the average vibration amplitude for all blades at a particular nodal diameter. With this approach, both blade-tip timing and tip clearance measurements can be carried out simultaneously. The results obtained on the test turbine rig demonstrate the suitability and reliability of the type of sensor used, and suggest the possibility of performing these measurements in real turbines under real working conditions.

Inspiratory Muscle Training Improves Maximal Inspiratory Pressure Without Increasing Performance in Elite Swimmers.

PURPOSE: To analyze the effect of inspiratory muscle training (IMT) on the maximal inspiratory mouth pressure (MIP) and performance of elite swimmers. METHODS: Eight participants performed a 3000-m swimming test (T-3000), followed by blood lactate measurements at 1 and 5 minutes postexercise.. The testing protocol was carried out before and after 6 weeks of IMT, in which a high-volume IMT group (HV-IMT) (n = 4) performed IMT twice a day-in the morning in a seated position and in the afternoon in a concurrent session of IMT and core muscle training. Also, a low-volume IMT group (LV-IMT) (n = 4) performed IMT in the morning session only. RESULTS: After the intervention, both groups improved their MIP, HV-IMT (132.75 [27.42] to 156.75 [21.88] cmH2O; P = .010; d = 0.967) and LV-IMT (149.25 [22.82] to 171.50 [23.74] cmH2O; P = .013; d = 0.955), without a significant difference between groups (P = .855). Regarding swimming performance, there were no changes between groups in the T-3000 (P = .472) or lactate removal rate (P = .104). CONCLUSION: IMT increased inspiratory muscle strength in elite swimmers, but there was no association or meaningful impact on swimming performance.

Changes in brown adipose tissue induced by resveratrol and its analogue pterostilbene in rats fed with a high-fat high-fructose diet.

Natural bioactive compounds have attracted a great deal of attention since some of them can act as thermogenesis activators. In recent years, special interest has been placed on resveratrol and its analogue pterostilbene, a dimethylether derivative that shows higher bioavailability. The aim of the present study is to compare the effects of resveratrol and its derivative pterostilbene on the thermogenic capacity of interscapular brown adipose tissue (iBAT) in rats under a high-fat high-fructose diet. Rats were divided into four experimental groups: control, high-fat high-fructose diet (HFHF) and HFHF diet supplemented with 30 mg/kg body weight/day of pterostilbene (PT30) or resveratrol (RSV30), for eight weeks. Weights of adipose tissues, iBAT triglycerides, carnitine palmitoyltransferase 1A (CPT1A) and citrate synthase (CS) activities, protein levels of uncoupling protein 1 (UCP1), sirtuins (SIRT1 and 3), AMP-activated protein kinase (AMPK), glucose transporter (GLUT4), fatty acid synthase (FAS), nuclear respiratory factor (NRF1), hormone-sensitive lipase (HSL), adipose triglyceride lipase (ATGL), CD36 and FATP1 fatty acid transporters, peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1) activation and the batokines EPDR1 and NRG4 were assessed in iBAT. The results show that some key proteins related to thermogenesis were modified by either pterostilbene or resveratrol, although the lack of effects on other crucial proteins of the thermogenic machinery suggest that these compounds were not able to stimulate this process in iBAT. Overall, these data suggest that the effects of stilbenes on brown adipose tissue thermogenic capacity depend on the metabolic status, and more precisely on the presence or absence of obesity, although further studies are needed to confirm this hypothesis.

Comparative study of limbal stem cell deficiency diagnosis methods: detection of MUC5AC mRNA and goblet cells in corneal epithelium.

PURPOSE: To evaluate a limbal stem cell deficiency (LSCD) diagnosis method based on the detection of the MUC5AC transcript by reverse transcription-polymerase chain reaction (RT-PCR) in comparison with the standard diagnostic method based on goblet cell detection by periodic acid-Schiff (PAS)-hematoxylin staining, using samples obtained from corneal epithelium impression cytology (IC). DESIGN: Transversal, comparative case series. PARTICIPANTS: We studied 59 eyes from 43 patients clinically diagnosed with LSCD. METHODS: Impression cytology was used to gather cells from corneal and conjunctival epithelium from the same eye. The presence of goblet cells in the cornea was determined by PAS-hematoxylin staining, whereas the presence of the MUC5AC transcript was detected by RT-PCR using a custom-designed primer pair. MAIN OUTCOME MEASURES: Goblet cells in the corneal epithelium were detected by light microscopy, and the MUC5AC transcript was detected as the corresponding PCR amplicon in agarose gels. RESULTS: Our study included 59 corneal samples, together with their respective conjunctival samples for RT-PCR assays. Of these, 47 samples were also available for comparative PAS-hematoxylin staining. The MUC5AC amplicon was detected in 56 of 59 (94.9%) corneal epithelium samples. In contrast, conventional IC staining detected goblet cells in only 17 of 47 (36.2%) samples; these were not found in 27 of 47 (57.4%) samples (negative results), and 3 of 47 (6.4%) showed inconclusive results. CONCLUSIONS: The detection of the MUC5AC transcript in corneal epithelium is a more sensitive method to diagnose LSCD than the conventional PAS-hematoxylin method, although a minimum RNA concentration of 1.2 ng/µl is required for negative results to be reliable. Moreover, RT-PCR is a highly specific and more objective technique. Overall, these findings indicate that molecular analysis facilitates a more precise clinical diagnosis of LSCD, thereby reducing the risk of surgical failure.

Variability in the Beneficial Effects of Phenolic Compounds: A Review.

When analysing the beneficial effects of phenolic compounds, several factors that exert a clear influence should be taken into account. The content of phenolic compounds in foods is highly variable, directly affecting individual dietary intake. Once ingested, these compounds have a greater or lesser bioaccessibility, defined as the amount available for absorption in the intestine after digestion, and a certain bioavailability, defined as the proportion of the molecule that is available after digestion, absorption and metabolism. Among the external factors that modify the content of phenolic compounds in food are the variety, the cultivation technique and the climate. Regarding functional foods, it is important to take into account the role of the selected food matrix, such as dairy matrices, liquid or solid matrices. It is also essential to consider the interactions between phenolic compounds as well as the interplay that occurs between these and several other components of the diet (macro- and micronutrients) at absorption, metabolism and mechanism of action levels. Furthermore, there is a great inter-individual variability in terms of phase II metabolism of these compounds, composition of the microbiota, and metabolic state or metabotype to which the subject belongs. All these factors introduce variability in the responses observed after ingestion of foods or nutraceuticals containing phenolic compounds.

Swimming exercise transiently decrease lung diffusing capacity in elite swimmers.

BACKGROUND: Swimmers have larger lungs and a higher diffusion capacity than other athletes, but it remains unknown whether swimming exercise changes lung diffusing properties. This study aimed to evaluate modifications in pulmonary alveolar-capillary diffusion after swimming exercise. METHODS: The participants were 21 elite level swimmers, including 7 females and 14 males, with a training volume of 45-70 kilometers of swimming per week. The single-breath method was used to measure the lung diffusing capacity for carbon monoxide (DLCO and the transfer coefficient of the lungs for carbon monoxide (KCO) before and after 10 training sessions over 4 weeks along 207 pre- to postevaluations. RESULTS: Swimming training consistently decreased lung diffusion capacity during the follow-up period, both DLCO (44.4±8.1 to 43.3±8.9 mL·min-1·mmHg-1, P=0.047, ŋ2p=0.55) and KCO (5.92±0.79 to 5.70±0.81 mL·min-1·mmHg-1·L-1, P=0.003, ŋ2p=0.75). CONCLUSIONS: Elite swimmers experience a subclinical impairment in lung diffusing capacity after swimming exercise, but the stress caused by swimming on the lungs and the acute reduction in DLCO does not lead to physiological dysfunction.

Stroking Rates of Open Water Swimmers during the 2019 FINA World Swimming Championships.

The aim of the present research was to examine the stroking rate (SR) values of successful and non-successful swimmers in the 10 km and 25 km races of the FINA 2019 World Swimming Championships. Data from 175 participants (95 men and 80 female) were classified according to their finishing positions. There were no meaningful differences in the overall SR values displayed by successful or non-successful participants during the 10 km and 25 km open water races of the FINA 2019 World Swimming Championships. However, there were changes in the SR throughout the races that depended on the swimmer's performance group and gender. Successful swimmers in the 10 km event typically displayed even SR in the first 5 km but, unlike the remaining performance groups, increased their SR at some point in the second 5 km of the race. In the 25 km race, successful female swimmers presented an even SR profile for most of the race, whereas successful males presented a more variable profile. Nevertheless, no relationships between partial or average SR and finishing positions occurred, either in the 10 km or in the 25 km race. Changes in the SR values should be included in the race plan of open water swimmers according to tactical and pacing strategies.