Some applications of indirect calorimetry to sports medicine

Some applications of indirect calorimetry to sports medicine are discussed and exemplified by case reports. In particular, it is suggested that oxigen consumption can be employed to assess the effects of physical activity on fat-free tissues and that the respiratory quotient may offer some insights into the food habits of athletes

Minimally invasive spin sensing with scanning tunneling microscopy

Minimizing the invasiveness of scanning tunneling measurements is paramount for observation of the magnetic properties of unperturbed atomic-scale objects. We show that the invasiveness of STM inspection on few-atom spin systems can be drastically reduced by means of a remote detection scheme, which makes use of a sensor spin weakly coupled to the sensed object. By comparing direct and remote measurements we identify the relevant perturbations caused by the local probe. For direct inspection we find that tunneling electrons strongly perturb the investigated object even for currents as low as 3 pA. Electrons injected into the sensor spin induce perturbations with much reduced probability. The sensing scheme uses standard differential conductance measurements, and is decoupled both by its non-local nature, and by dynamic decoupling due to the significantly different time scales at which the sensor and sensed object evolve. The latter makes it possible to effectively remove static interactions between the sensed object and the spin sensor while still allowing the spin sensing. In this way we achieve measurements with a reduction in perturbative effects of up to 100 times relative to direct scanning tunneling measurements, which enables minimally invasive measurements of a few-atom magnet's fragile spin states with STM

Variable Repetition Rate THz Source for Ultrafast Scanning Tunneling Microscopy

Broadband THz pulses enable ultrafast electronic transport experiments on the nanoscale by coupling THz electric fields into the devices with antennas, asperities, or scanning probe tips. Here, we design a versatile THz source optimized for driving the highly resistive tunnel junction of a scanning tunneling microscope. The source uses optical rectification in lithium niobate to generate arbitrary THz pulse trains with freely adjustable repetition rates between 0.5 and 41 MHz. These induce subpicosecond voltage transients in the tunnel junction with peak amplitudes between 0.1 and 12 V, achieving a conversion efficiency of 0.4 V/(kV/cm) from far-field THz peak electric field strength to peak junction voltage in the STM. Tunnel currents in the quantum limit of less than one electron per THz pulse are readily detected at multi-MHz repetition rates. The ability to tune between high pulse energy and high signal fidelity makes this THz source design effective for exploration of ultrafast and atomic-scale electron dynamics

Dietary exposure estimates to fifteen trace elements in an adult population of Emilia Romagna region, Northern Italy

The health effects and the exposure levels of trace elements in humans are important public health topics. Assessing their dietary intake is fundamental to evaluate the long-term risks for public health and for food safety assessment. Since a priority of food safety regulatory agencies is to ensure the protection of consumers and to assess the health risks for the general population, to estimate the actual dietary intake of trace elements for comparison with the upper and lower tolerable levels is very important. In this study, we aimed to evaluate the dietary intake of several trace elements in an Italian community, namely of antimony, barium, beryllium, boron, cobalt, lithium, molybdenum, nickel, silver, strontium, tellurium, thallium, titanium, uranium, and vanadium. To do that, in 2016-2017 we collected a total of 908 food samples available in Italian markets and groceries from two Northern Italy provinces (Modena and Reggio Emilia), and we measured their trace element content through inductively-coupled plasma mass spectrometry. We also administered a validated semi-quantitative food frequency questionnaire to 708 residents (300 men and 48 women) in the Emilia-Romagna Region, to assess their dietary habits and eventually to estimate their dietary intake of the aforementioned trace elements. Overall, study results showed that in our population the dietary exposure levels to selected trace elements could be considered similar to that observed in other European and non-European populations. Though we cannot rule out the possibility that the dietary exposure estimates in the present study may not be representative of the population as a whole, our results provide a good and updated assessment of trace elements far frequently evaluated in a sample of Italian adult consumers from the Emilia Romagna region. Our findings finally suggest that our population should not be at risk of adverse health effects in relation to excess or deficiency of the investigated trace elements since the estimated dietary intake generally point out exposure levels within the safe range as far as indicated by recommendations of international agencies

Reliability of Multisensor Armband in Estimating Energy Expenditure According to Degree of Obesity

Resting energy expenditure (REE) represents the amount of calories required by the body to maintain vital bodyfunctions. One of the most commonly used methods for estimating REE is indirect calorimetry. Recent studies ondifferent populations have validated a highly innovative instrument, the SenseWear® Armband (SWA), which evaluatestotal energy expenditure and, when used in resting conditions, could also evaluate REE. The purpose of this study wasto determine the agreement of the SWA in assessing REE in obese subjects and, see how this agreement varies withdifferent obesity degree.89 obese subjects (59 women and 30 men), with an age range from 35-65 years and body mass index (BMI)34.5 4.5 kg/m2 were studied. REE was measured by IC Sensor Medics Vmax (SM-29N) and by SWA. Fat mass(FM) and fat-free mass (FFM) was determined by anthropometry and bio-impedance measurements. No statisticaldifference was found between REE measured by SWA (1693±276) and REE measured by SM-29N (1627±293). Thetwo methods showed similar assessments (r=0.8, p 35 kg/m2), the agreement decreases (r =0.6 p 35

Dietary intake of calcium, phosphorus and magnesium in a Northern Italian community.

Minerals are essential micronutrients for growth, development, and maintenance of healthy tissues, the long term insufficient intake of minerals may lead to bone demineralization and often requires the use of food supplements. The ratios of certain minerals intake like calcium and phosphorus are also proved to can affect the bioavailability of calcium and even lead to adverse health consequence. This study was designed to explore the dietary sources of calcium (Ca), phosphorus (P), and magnesium (Mg) and the ratios between different minerals (Ca/P). We measured the content of these elements in foods composing typical Italian diet using inductively coupled plasma-mass spectrometry and we estimated their daily dietary intakes assessing through a semi-quantitative food frequency questionnaire specifically developed within the European Prospective Investigation into Cancer and Nutrition (EPIC) study in a Northern Italian Community. In 890 analyzed food samples the main contributors to calcium are milk and dietary products, dry fruits, legumes and sweet products. Important sources of phosphorus are represented by dry fruits, legumes, milk and dairy products and meat. While dry fruits, legumes, cereals and fish symbolized the most important sources for magnesium. In our Italian population sample, the estimated median (interquartile range) dietary daily intakes are 786.3 (592.2-1062.7) μg/day for calcium; 1291.7 (1017.2-1591.4) mg/day for phosphorus and 323.2 (260.3-396.6) mg/day for magnesium. The calcium-phosphorus (Ca/P) ratio in this study was 0.63 (0.52-0.73). These values are in agreement with those suggested by European and International recommended intake for adult population, with the exception of calcium which is slightly lower than recommended values and suggest that this population does not present nutritional deficiencies requiring any supplementation

Assessment of food contamination and dietary intake of lead and thallium in a Northern Italy population.

Lead and thallium are heavy metals released in the environment after natural and anthropogenic activities. Food and water intake are the major sources of human exposure to these elements. In this study, we aimed at characterizing lead and thallium content in foods consumed in Northern Italy population, in order to estimate the dietary intake of these metals. To do that we bought food samples in markets and groceries collected during the period from October 2016 to February 2017 in the Emilia Romagna region, and we measured their element content using inductively coupled plasma-mass spectrometry. Finally, after assessing dietary habits of an Emilia-Romagna community by using a validated food frequency questionnaire, we eventually estimated dietary intake of these metals in that community. In the 890 analyzed food samples, the highest lead contamination levels were found in seafood, vegetables, sweets and beverages. The estimated dietary intake of lead was 5.758 (interquartile range-IQR: 4.547-7.427) µg/day, corresponding to 0.089 (IQR: 0.069-0.113) µg/kg of body weight per day, with cereals, beverages and vegetables as major contributors. About thallium, one third of specimens showed very low levels below the limit of detection, with the highest contamination levels in vegetables, dry fruits and sweets. The dietary intake of thallium was 0.236 (IQR: 0.183-0.312) µg/day, mainly from vegetables, beverages, cereals and sweets. In conclusion, our study provides an estimation of lead and thallium intake in a Northern Italian community and shows a generally low exposure levels from dietary sources

Effect of intense military training on body composition

Individuals in a structural physical training program can show beneficial changes in body composition, such as body fat reduction and muscle mass increase. This study measured body composition changes by using 3 different techniques-skinfold thickness (SF) measurements, air displacement plethysmography (BOD-POD), and dual-energy x-ray absorptiometry (DXA)-during 9 months of intense training in healthy young men engaged in military training. Twenty-seven young men were recruited from a special faction of the Italian Navy. The program previewed three phases: ground combat, sea combat, and amphibious combat. Body composition was estimated at the beginning, in the middle, and at the end of the training. After the subjects performed the ground combat phase, body composition variables significantly decreased: body weight (P < 0.05), fat-free mass (FFM) (P < 0.001), and fat mass (FM) (P < 0.03). During the amphibious combat phase, body weight increased significantly (P < 0.01), mainly because of an increase in FFM (P < 0.001) and a smaller mean decrease in FM. There was a significant difference (P < 0.05) in circumferences and SF at various sites after starting the training course. Bland-Altman analysis did not show any systematic difference between FM and FFM measured with the 3 different techniques on any occasion. On any visit, FFM and FM correlation measured by BOD-POD (P = 0.90) and DXA was significantly greater than measured by SF. A significant difference was found in body mass index (BMI) measured during the study. BOD-POD and SF, compared with DXA, provide valid and reliable measurement of changes in body composition in healthy young men engaged in military training. In conclusion, the findings suggest that for young men of normal weight, changes in body weight alone and in BMI are not a good measure to assess the effectiveness of intense physical training programs, because lean mass gain can masquerade fat weight loss

Sensitivity and specificity of body mass index and skinfold thicknesses in detecting excess adiposity in children aged 8-12 years

Primary objective: The study aimed to evaluate the sensitivity (SN) and specificity (SP) of body mass index (BMI) and skinfold thicknesses in detecting excess adiposity in children. Research design: Cross-sectional. Materials and methods: 986 children (500 females and 486 males) aged 10 +/- 1 years (mean +/- SD; range: 8-12 years) were studied. All underwent anthropometric measurements and bioelectrical impedance analysis (BIA). Dual-energy X-ray absorptiometry (DXA) was performed in 52 children to develop a population-specific algorithm for the assessment of fat-free mass (FFM) from BIA. The algorithm was applied to the remaining 934 children to estimate their FFM. Fat mass (FM) was obtained by subtracting FFM from weight (Wt). Values of FM:Wt were transformed in Z-scores and converted into 19 percentile categories (from 5 to 95 in steps of 5). The same procedure was performed with BMI and the log-transformed sum of four skinfold thicknesses (triceps, biceps, subscapular and suprailiac; lt-4SF). Excess adiposity was defined as a level of FM:Wt greater than the internally derived 85th percentile. SN and SP of each internally derived percentile of BMI and lt-4SF in detecting excess adiposity were calculated. Results: In the pooled sample (n = 934), SN and SP were 0.39 and 0.99 for the 95th percentile of BMI, 0.65 and 0.95 for the 85th percentile of BMI, and 0.75 and 0.94 for the 85th percentile of lt-4SF. Conclusions: BMI percentiles employed in the present study have a high SP but a low SN in detecting excess adiposity in 8-12-year-old children. The use of the sum of four skinfolds has the potential to increase the SN of a screening programme for excess adiposity in children of this age