Composition Analysis Research Articles

Essential oil and waste hydrosol of Ocimum tenuiflorum L.: A low-cost raw material source of eugenol, botanical pesticides, and therapeutic potentiality.

In this study, essential oils and waste hydrosols of leaves of Ocimum tenuiflorum in four different geographical locations were extracted by hydrodistillation method and using gas chromatography / mass spectrometry (GC/MS) for chemical composition analysis. All four essential oil samples contained the main components (E)-β-caryophyllene (27.8-49.0%), trans-β-elemene (20.3-37.1%) and eugenol (9.0-44.0%). Three of the four hydrosol samples had eugenol in absolute content (94.5-98.6%), while the remaining hydrosol sample had two main components, elemicin (77.8%) and eugenol (14.2%). Essential oils and hydrosols demonstrated larvicidal activities against four important disease-transmitting mosquito species including Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Culex fuscocephala with 24-h LC50 values in the range 15.42-56.01 µg/mL and 53.88-97.80 µg/mL for the essential oils and the hydrosols, respectively. Essential oils and hydrosols strongly inhibited the acetylcholinesterase (AChE) enzyme of electric eels with IC50 values in the range of 25.35-107.19 µg/mL. Microemulsion (ME) can be considered as a sustainable pesticide formulation over 300 days and has improved larvicidal activity compared to free essential oil. The O. tenuiflorum in Vietnam can be considered a low-cost source of eugenol, botanical pesticides that control disease-transmitting mosquitoes, as well as having therapeutic potential to be further investigated.

Compositional analysis of invertebrate communities in Raja Ampat conservation zones using environmental DNA (eDNA)

Raja Ampat conservation area is divided into three zones: the core zone, the tourism zone, and the open zone. This region is crucial for sustainable fisheries and environmental management, yet it is under significant anthropogenic pressure. Accurate species detection is essential for inventory and diversity surveys, and environmental DNA (eDNA) methods have been shown to be more effective than conventional techniques. This study aimed to evaluate whether V9 primers could detect multispecies invertebrate compositions, assess community structure and contributions within each zone, and identify significant differences in invertebrate diversity among the zones. A total of 66 eDNA samples were collected from water and sediment columns across the three zones. Samples were extracted using the NucleoSpin™ kit (Macherey-Nagel) protocol, amplified with universal eukaryote primers targeting the 18S gene, and sequenced using Illumina MiSeq. Taxonomic analysis was performed using QIIME2 software and the SILVA database. The study identified 19 invertebrate species. The Shannon-Wiener (H') and Simpson (D) indices revealed greater species diversity in the core zone compared to the tourism and open zones. However, the Kruskal-Wallis test indicated no significant differences in species diversity across the zones. SIMPER analysis demonstrated a high percent contribution of species in each zone. This study highlights the effectiveness of eDNA methods for biodiversity assessment and offers valuable insights into invertebrate community structures within the Raja Ampat conservation area.

Study of inclusions-removal and slag-metal dispersion phenomenon in gas-stirred ladle

Abstract The slag-metal interface serves as a crucial locus for both chemical reactions and the adsorption of inclusions during secondary refining. This study first comprehensively reviews the methods of inclusions removal and then establishes a cold-state experiment using a water-oil system to reappear the phenomenon of slag-metal dispersion and inclusion adsorption. The distribution of slag droplets under varying slag volumes is analyzed in terms of the effect of bottom blow rates. Simultaneously, the volumetric fraction of oxygen on the slag-eye surface is analyzed. The result proved that the increase in oil layer thickness or the gas flow rate increase the volume of entrained oil. The dimensionless depth of entrained droplets was positively associated with gas flow rate or oil thickness. The dimensionless depth of “large droplets” and “small droplets” was in the range of 0–25 % and 0–60 %, respectively. Moreover, analysis of the gas composition above the slag-eye in a water-oil system is used to determine the degree of secondary oxidation. The oxygen volume fraction over the surface of the slag-eye decreases with the increase of gas flow rate. The oxygen volume fraction over the surface of the slag-eye is 1.51 % when the gas flow rate is 9 L/min.

Dynamic analysis of 3D-printed CF-PETG composites with different infill densities

Dynamic analysis of 3D-printed CF-PETG composites with different infill densities

Comparative Outcomes of Surgical and Transcatheter Aortic Valve Replacement: A Meta-analysis and Parametric Extrapolation of Clinical Trials

IntroductionWe aimed to pool randomized clinical trials (RCTs) comparing surgical aortic valve replacement (SAVR) with transcatheter aortic valve replacement (TAVR) and extrapolate pooled time-to-event data to compare long-term outcomes. MethodsAn electronic database search was performed for RCTs comparing SAVR with TAVR. The most current longest follow-up data for each RCT were included. Data were pooled using a random-effects model. Survival data were pooled for Kaplan–Meier analysis as well as parametric modeling with extrapolation. ResultsSeven RCTs comprising 7774 patients were included. Mean valve gradient at 5 y was comparable between SAVR [11 mmHg (3.7; 18.3)] and TAVR [8.1 mmHg (1.9; 14.3)] (P = 0.38). TAVR had a higher mean valve area at 30 d, 1 y, and 2 y [1.68 cm2 (1.22; 2.13) versus 1.8 cm2 (1.35; 2.25), P = 0.02]. SAVR had a higher freedom from any paravalvular leak at 30 d and 1 y [86% (81; 90) versus 39% (36; 41), P < 0.01]. All-cause death was lower in the SAVR group at 5 y [39% (29; 50) versus 43% (31; 57), P < 0.01]. Although no differences were seen between SAVR and TAVR in the pooled Kaplan–Meier analysis of all-cause mortality and composite of all-cause mortality or stroke, parametric modeling with extrapolation showed significant divergence for both outcomes. ConclusionsPooled all-cause mortality as well as pooled composite of all-cause mortality or stroke indicated better survival with SAVR at 5 y. Long-term parametric extrapolation also indicated superior survival with SAVR.

Compositional analysis of tuberose floral cuticle sheds light on scent volatile emission and cuticle deposition

The plant cuticle acts as a vital shield, safeguarding against environmental and biological stresses. Tuberose flowers, specifically the ‘Calcutta Single’ and ‘Calcutta Double’ cultivars of Agave amica (syn. Polianthes tuberosa), are highly prized in India for their aromatic and aesthetic appeal. This research examines the tuberose floral cuticle using GC-MS to identify key chemical components and their characteristics. The analysis uncovered six major chemical classes viz. fatty acids, fatty alcohols, esters, alkanes, alkenes, and aldehydes as the primary constituents of the cuticular wax. Fatty acids and fatty alcohols are dominant in both cultivars, with ‘Calcutta Single’ displaying a higher ester content than ‘Calcutta Double’. This study represents the inaugural in-depth exploration of cuticular wax in tuberose flowers, presenting a comparative investigation into these prominent cultivars.

GC-MS analysis and nutra-pharmaceutical potential of Mentha piperita essential oil extracted by supercritical fluid extraction and hydro-distillation

This study reports the comparative evaluation of yield, physico-chemical composition and biological attributes (antioxidant activity, antimicrobial activity, biofilm inhibition and hemolytic activity) of peppermint (Mentha piperita L.) essential oil (EO) obtained by hydro-distillation (HD) and supercritical fluid (CO2) extraction (SCFE) methods. The yield (%) of EO obtained by HD (0.20 %) was significantly (p < 0.05) higher than that of SCFE (0.13 %) while the variation in the physical parameters like solubility, color, density (at 25 °C) and refractive index (at 25 °C) was not significant between the tested oils. The data of chemical compositional analysis revealed that menthol was the key component in the EO obtained by HD (52.85 %) and SCFE (45.51 %), followed by menthone [HD (25.93 %) and SCFE (27.3 %)] and eucalyptol [HD (8.59 %); SCFE (8.92 %)]. The EO extracted with supercritical fluid (SCFE-EO) exhibited superior (p < 0.05) DPPH free radical inhibition potential (52 %) with an IC50 value of 15.65 μg/mL and reducing power compared to that of HD-EO. The highest antimicrobial activity was exhibited by SCFE-EO against Pasturella multocida with an inhibition zone of 18.00 mm (MIC value of 86 μg/mL). The results of biofilm inhibition and hemolytic activity revealed that the SCFE method was superior to recover high quality EO in comparison to the HD method. The peppermint EO obtained by SCFE, owing to potent bioactive components, can be a potential candidate to develop nutra-pharmaceuticals.

Structural and Compositional Analysis of CZTSSe Thin Films by Varying S/(S+Se) Ratio

Structural and Compositional Analysis of CZTSSe Thin Films by Varying S/(S+Se) Ratio

Development of a dissolution method for analyzing the elemental composition of fuel debris using sodium peroxide fusion technique

ABSTRACT A dissolution method for analyzing the elemental composition of fuel debris using the sodium peroxide (Na2O2) fusion technique has been developed. Herein, two different types of simulated fuel debris (such as solid solution of (Zr,RE)O2 and molten core – concrete interaction products (MCCI)) were taken. At various temperatures, these debris samples were subsequently fused with Na2O2 in crucibles, which are made of different materials (Ni, Al2O3, Fe, and Zr). Then, the fused samples are dissolved in nitric acid. Effects of the experimental conditions on the elemental composition analysis were evaluated using inductively coupled plasma-atomic emission spectroscopy (ICP – AES), which suggested the use of a Ni crucible at 923 K as an optimum testing condition. The optimum testing condition was then applied to the demonstration tests with Three Mile Island unit-2 (TMI-2) debris in a shielded concrete cell, thereby achieving complete dissolution of the debris. The elemental composition of TMI-2 debris revealed by the proposed dissolution method has good reproducibility and has an insignificant contradiction in the mass balance of the sample. Therefore, this newly developed dissolution method can be effectively utilized in practical applications by dissolving fuel debris and analyzing its elemental composition.

SYNTHESIS AND CHARACTERIZATION OF MAGNETITE NANOMATERIALS IN TIANYAR IRON SAND USING CO-PRECIPITATION METHOD

In the current era of scientific and technological progress, nanomaterials have emerged as a deeply fascinating and significant field of research. This paper presents a case study on the synthesis and characterization of Fe₃O₄ nanomaterials derived from the iron sand of the Tianyar, utilizing the co-precipitation method with modifications made to the pH values during synthesis. The research encompasses three primary stages: extraction of iron sand, synthesis of Fe3O4 nanomaterials, and subsequent characterization of these nanomaterials. The iron sand extraction phase involved passing it through a permanent magnet ten times to remove impurities. Subsequent synthesis produced a dark black magnetite nanomaterial powder displaying magnetic properties, rendering it responsive to magnet attraction. Analysis of these nanomaterials using X-ray diffraction (XRD) unveiled discernible peaks in the diffraction pattern, suggesting that the magnetite nanomaterials possess a cubic crystal structure. The size of the Fe3O4 nanomaterials decreases as the pH of precipitation increases, with respective sizes of approximately 18.00 nm for pH 9, 14.69 nm for pH 10, and around 13.68 nm for pH 11, as determined using Scherrer’s formula. The lattice parameters observed for samples synthesized at pH 9, 10, and 11 are sequentially measured as a = 8.59 Å, 8.81 Å, and 8.80 Å. Analysis using SEM-EDS revealed that the sample morphology appears rough, with evidence of particle agglomeration leading to uneven particle distribution. There are additional trace elements present, including C, Al, S, Ti, and Cl, albeit in smaller quantities. Nevertheless, the primary elements crucial for forming Fe3O4 nanomaterials, namely Fe and O, exhibit the highest percentages in composition analysis.

Utilization of mycelial polysaccharide from Schizophyllum commune for the formation of highly stable o/w emulsion

This study investigated the emulsifying properties of a hot water extracted polysaccharide (SCMP) derived from liquid fermentation mycelium of Schizophyllum commune in stabilizing oil-in-water (o/w) emulsions. SCMP demonstrated the ability to stabilize o/w emulsions (referred to as SCMPe) for extended periods (>21 days) even at low concentrations (2 g/L) and increased the viscosity and elasticity of the emulsion system. Through confocal laser-scanning microscope visualization, it was observed that SCMP created a physical barrier on the surface of the oil droplets, contributing to emulsion stability. Furthermore, SCMPe demonstrated excellent tolerance to varying concentrations of Na+ (0.1–0.5 mol/L) and Ca2+ (0.01–0.05 mol/L) as well as a wide pH range (3.0–9.0). Moreover, increasing SCMP concentration effectively inhibited lipid oxidation and improved the stability of β-carotene and curcumin in the emulsion during storage. A detailed analysis of SCMP's composition and structure was done to better understand its emulsifier properties, revealing SCMP to be composed of two β-glucans with a rigid chain and high molecular weight. These results suggest that SCMP holds great potential an efficient stabilizer in the food industry, particularly in enhancing emulsion stability.

Integrative Transcriptomic and Single-Cell Protein Characterization of Colorectal Carcinoma Delineates Distinct Tumor Immune Microenvironments Associated with Overall Survival.

Colorectal carcinoma (CRC) is a heterogeneous group of tumors with varying therapeutic response and prognosis, and evidence suggests the tumor immune microenvironment (TIME) plays a pivotal role. Using advanced molecular and spatial biology technologies, we aimed to evaluate the TIME in patients with CRC to determine whether specific alterations in the immune composition correlated with prognosis. We identified primary and metastatic tumor samples from 31 consented patients, which were profiled with whole-exome sequencing and bulk RNA-seq. Immune cell deconvolution followed by gene set enrichment analysis and unsupervised clustering was performed. A subset of tumors underwent in situ analysis of the TIME spatial composition at single-cell resolution through Imaging Mass Mass Cytometry. Gene set enrichment analysis revealed two distinct groups of advanced CRC, one with an immune activated phenotype and the other with a suppressed immune microenvironment. The activated TIME phenotype contained increased Th1 cells, activated dendritic cells, tertiary lymphoid structures, and higher counts of CD8+ T cells whereas the inactive or suppressed TIME contained increased macrophages and a higher M2/M1 ratio. Our findings were further supported by RNA-seq data analysis from the TCGA CRC database, in which unsupervised clustering also identified two separate groups. The immunosuppressed CRC TIME had a lower overall survival probability (HR 1.66, p=0.007). This study supports the pertinent role of the CRC immune microenvironment in tumor progression and patient prognosis. We characterized the immune cell composition to better understand the complexity and vital role that immune activity states of the TIME play in determining patient outcome.

Emerging investigator series: Coprecipitation with glucuronic acid limits reductive dissolution and transformation of ferrihydrite in an anoxic soil.

Ferrihydrite, a poorly crystalline Fe(III)-oxyhydroxide, is abundant in soils and is often found associated with organic matter. Model studies consistently show that in the presence of aqueous Fe(II), organic carbon (OC)-associated ferrihydrite undergoes less transformation than OC-free ferrihydrite. Yet, these findings contrast microbial reductive dissolution studies in which the OC promotes the reductive dissolution of Fe(III) in ferrihydrite and leads to the release of associated OC. To shed light on these complex processes, we quantified the extent of reductive dissolution and transformation of native Fe minerals and added ferrihydrite in anoxic soil incubations where pure 57Fe-ferrihydrite (57Fh), pure 57Fe-ferrihydrite plus dissolved glucuronic acid (57Fh + GluCaq), a 57Fe-ferrihydrite-13C-glucuronic acid coprecipitate (57Fh13GluC), or only dissolved glucuronic acid (13GluCaq) were added. By tracking the transformation of the 57Fe-ferrihydrite in the solid phase with Mössbauer spectroscopy together with analysis of the iron isotope composition of the aqueous phase and chemical extractions with inductively coupled plasma-mass spectrometry, we show that the pure 57Fe-ferrihydrite underwent more reductive dissolution and transformation than the coprecipitated 57Fe-ferrihydrite when identical amounts of glucuronic acid were provided (57Fh + GluCaqversus57Fh13GluC treatments). In the absence of glucuronic acid, the pure 57Fe-ferrihydrite underwent the least reductive dissolution and transformation (57Fh). Comparing all treatments, the overall extent of Fe(III) reduction, including the added and native Fe minerals, determined with X-ray absorption spectroscopy, was highest in the 57Fh + GluCaq treatment. Collectively, our results suggest that the limited bioavailability of the coprecipitated OC restricts not only the reductive dissolution of the coprecipitated mineral, but it also limits the enhanced reduction of native soil Fe(III) minerals.

Modeling the impact of plastic oil obtained from xlpe cable wastes on diesel engine performance and combustion parameters with the response surface method

The world's expanding population requires alternative energy sources to meet its energy needs. One such alternative is the efficient recovery of plastic waste through pyrolysis. The liquid produced from waste plastics via pyrolysis is a valuable commodity that may serve as fuel substituted for internal combustion engines. In this study, waste plastic oil (WPO) and diesel fuel (D100) blends (10%, 20%, 30%, 40% and 50% by volume) obtained by pyrolysis of waste XLPE cables were experimentally investigated and analyzed using response surface methodology (RSM) to determine their effects on the combustion parameters of a four-stroke, single cylinder diesel engine at different engine loads (750, 1500, 2250, 3000, 3750 and 4500 W). A response surface model was constructed using a two-factor central composite complete design and analysis of variance based on the experimental results obtained. The model determined the optimum values of WPO ratio and engine load that correspond to one of the finest brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), hydrocarbon (HC), carbon monoxide (CO), nitrogen oxides (NOx), and smoke emission levels. The study's optimization findings indicated that the optimal WPO ratio is 19.6%, and the optimal engine load is 2600 W. The BTE, BSFC, CO, HC, NOx, and smoke were found to be 22.3%, 332.3 g/kWh, 0.033%, 31.5 ppm, 397.9 ppm, and 1.63%, respectively, at the optimal WPO ratio and engine load. The R2 (correlation coefficient) values for BTE, BSFC, CO, HC, NOx, and smoke emissions were determined to be 99.95%, 97.76%, 98.10%, 99.74%, 99.74%, 99.79%, and 95.67%, respectively. The mean error rates, ranging from 0.64% to 4.27%, were deemed satisfactory when comparing the replies to the experimental data. The findings of this study demonstrated that the response surface method is a very efficient approach for forecasting and enhancing a diesel engine's performance and emission characteristics by using waste plastic oil.

The influence of low temperature rise polymer on early cement hydration from the point of view of hydration kinetics and thermodynamics

The key to studying the influence mechanism of additives on the cement hydration process lies in revealing the influence process of admixtures on the evolution of chemical driving forces of relevant phases in the cement hydration process. This study is the first to adopt the Krstulovic-Dabic (K-D) kinetic model to investigate the hydration mechanism and kinetic parameters of a cement system with a low-temperature polymer (CAMC). Gibbs Energy Minimization Selektor (GEMS) was used for pore solution composition analysis of cementitious system and calculation of saturation index. The results show that the exponent and reaction rate constant of the (K-D) model decrease with the increase of hydration age and CAMC content, with K1 significantly greater than K2 and K3 being the smallest. The saturation index of calcium hydroxide (CH) and ettringite (AFt) is greater than 0, indicating that both phases are supersaturated in all samples. The transition time from supersaturation to undersaturation of gypsum is delayed, confirming the delayed consumption of gypsum by CAMC. This provides new insights into the effects of admixtures on cement hydration and the mechanisms of cement hydration.

An energy transfer strategy towards versatile sensing applications from Cr3+ and Yb3+ codoped near infrared phosphors

Near-infrared (NIR) phosphors have garnered notable attention for their extensive applications in anti-counterfeiting, optical imaging, non-invasive medical diagnosis and detection. Nevertheless, the quest for NIR phosphors with outstanding detection and sensing capabilities remains a challenge. In this study, we have successfully prepared Ga1.6Mg0.2Ge0.2O3:Cr3+,Yb3+ NIR phosphors by codoping and substitutation strategies. When incorporated into polydimethylsiloxane films, these phosphors demonstrated a direct correlation between luminescence intensity ratio and applied stress under 450 nm excitation. Moreover, variations in luminescence spectra occurred with different compositions and concentrations of liquids coated on the film, facilitating both force measurement and composition analysis. Furthermore, a NIR phosphor-converted light-emitting diode (pc-LED) was fabricated by integrating phosphor with a blue LED chip, exhibiting excellent performance. Utilizing the prepared NIR pc-LED as a light source, we facilitated non-destructive imaging, night vision, and anti-counterfeiting applications with an infrared camera. These findings suggest that the synthesized NIR phosphors possess hold promise for diverse detection and sensing applications.

Understanding the source and evolution of precipitation stable isotope composition across O‘ahu, Hawai‘i, USA

Abstract Pacific Islands present unique challenges for water resource management due to their environmental vulnerability, dynamic climates, and heavy reliance on groundwater. Quantifying connections between meteoric, ground-, and surface waters is critical for effective water resource management. Analyses of the stable isotopes of oxygen and hydrogen in the hydrosphere can help illuminate such connections. This study investigates the stable isotope composition of rainfall on O‘ahu in the Hawaiian Islands, with a particular focus on how altitude impacts stable isotope composition. Rainfall was sampled at 20 locations from March 2018 to August 2021. The new precipitation stable isotope data were integrated with previously published data to create the most spatially and topographically diverse precipitation collector network on O‘ahu to date. Results show that δ18O and δ2H values in precipitation displayed distinct isotopic signatures influenced by geographical location, season, and precipitation source. Altitude and isotopic compositions were strongly correlated along certain elevation transects, but these relationships could not be extrapolated to larger regions due to microclimate influences. Altitude and deuterium-excess were strongly correlated across the study region, suggesting d-excess may be a reliable proxy for precipitation elevation in local water tracer studies. Analysis of spring, rainfall, and fog stable isotope composition from Mount Ka‘ala suggests fog may contribute up to 45% of total groundwater recharge at the summit. These findings highlight the strong influence of microclimates on the stable isotope composition of rainfall, underscore the need for further investigation into fog's role in the water budget, and demonstrate the importance of stable isotope analysis for comprehending hydrologic dynamics in environmentally sensitive regions.

Effect of rice husk morphology on the ability to synthesize silicon carbide by pyrolysis method

Silicon carbide (SiC) is a mineral with good technical properties and high economic value. However, the synthesis of SiC is expensive because it is synthesized at a high-temperature environment (above 1500oC). The synthesis of SiC from biomass can significantly reduce the synthesis temperature. One commonly used biomass material for synthesizing SiC is rice husk. However, the ability to synthesize SiC depends on the shape of the rice husk. The influence of the morphology of rice husk on the ability to synthesize SiC was studied in this study. Experimental results showed that the original rice husk would give better SiC formation capacity than the rice husk powder. The amount of SiC formed using the original rice husk when impregnated by sodium silicate solution and pyrolysis at 1200oC is 18.3% (wt%.). With rice husk powder, it is 15.12% (wt%.). The results of analysis of the mineral composition, functional groups, and morphologies by X-ray diffraction (XRD), Fourier Infrared Transform Method (FT-IR), and Scanning Electron Microscopy (SEM) found that the polymorphy of SiC is α-SiC and β-SiC. These minerals are the basis for SiC from rice husks, which can be applied as wear-resistant materials.

Body Composition and Dietary Intake Profiles of Elite Iranian Swimmers and Water Polo Athletes.

This study aimed to conduct a detailed and comparative analysis of body composition and dietary habits in elite swimming and water polo athletes. Through the examination of these key parameters, this study seeks to compare the dietary intake of these two distinct aquatic sports disciplines. A total of 10 top-level swimmers and 13 water polo athletes participated in anthropometric and body composition assessments, as well as a detailed analysis of nutritional intake. To compare the two groups, an independent samples t-test was used, and variance homogeneity was checked using Levene's test. The effect size of the group differences was evaluated using Hedges' g. Water polo athletes showed significantly greater height (189.4 ± 2.9 vs. 186.5 ± 2.0 cm, p = 0.013), body mass index (24.3 ± 1.4 vs. 22.1 ± 0.5 kg/m2, p < 0.001), fat-free mass (62.9 ± 1.4 vs. 61.1 ± 1.38 kg, p < 0.001), skeletal muscle mass (47.1 ± 1.3 vs. 43.9 ± 1.6 kg, p < 0.001), and overall weight (86.9 ± 6.9 vs. 76.7 ± 2.2 kg, p < 0.001) in comparison to swimmers. Swimmers consumed greater amounts of mean daily energy (60.0 ± 1.0 vs. 39.0 ± 1.0 kcal/kg, p < 0.001), carbohydrate (7.8 ± 0.3 vs. 4.4 ± 0.5 g/kg, p < 0.001), protein (1.7 ± 0.5 vs. 1.4 ± 0.5 g/kg, p < 0.001), and fat (2.4 ± 0.5 vs. 1.7 ± 0.5 g/kg, p < 0.001) compared to water polo athletes. Our findings highlight the need for differentiated targeted nutritional interventions to enhance athletic performance in different types of water sports. Compared to water polo athletes, swimmers consumed significantly higher amounts of calories, matching their increased calorie demand from their specific training regime. However, this is an observational study and the differential needs of energy and macronutrients in water sports should be confirmed by studies with energy expenditure measurements.

Relationship of body composition with middle cerebral artery hemodynamic using compositional data analysis: Toledo Study for Healthy Ageing in middle age.

Excess adipose tissue may promote chronic systemic inflammation and oxidative stress, causing endothelial damage. Early evidence indicates that obesity may be associated with poorer cerebral perfusion. The purpose of this study was to examine the relationship between body composition and cerebral hemodynamics. A total of 248 middle-aged adults (50-58 years old; 55% women) underwent a ramp test on a cycle-ergometer until volitional exhaustion. Gas exchange was assessed on a breath-by-breath basis. Mean middle cerebral artery velocity (MCAv) was measured using transcranial Doppler, and pulsatility index (PI) calculated. Body composition was assessed by dual X-ray absorptiometry. Statistical analyses were performed using a compositional data approach including a three-compartment model for body composition (trunk fat mass, extremities fat mass, and fat-free mass). The unadjusted models for the whole sample showed that trunk fat mass relative to other compartments was negatively associated with MCAvrest, MCAvmax, and gain, and positively associated with PImax; extremities fat mass relative to other compartments was positively associated with MCAvrest and MCAvmax, and negatively associated with PImax; and fat-free mass relative to other compartments was positively associated with PImax. These associations were sex-dependent, remaining in the women's subgroup. However, after adjusting for confounders, these associations became non-significant, except for PImax in the whole sample and women's subgroup. These findings suggest a possible association between cerebral hemodynamics and body composition in middle-aged adults, highlighting sex-specific differences. Moreover, our results indicate that higher trunk fat mass relative to other compartments may negatively impact cerebral hemodynamics, reducing MCAv and increasing PImax.