bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Aging Process Conditions on the Thermal Properties of Poly(Dimethylsiloxane)-Based Silicone Rubber
Authors: Morawska-Chochół Anna , Szumera Magdalena , Młyniec Andrzej , Pielichowska Kinga
Published: November 2024

Silicone rubbers based on poly(dimethylsiloxane) (PDMS) are crosslinked elastomers commonly used in various branches of industry, especially as packing materials in elements for high-temperature service. In addition to high temperatures, mechanical loading may influence their structure during their work, and, as a consequence, their thermal properties may change. This study’s findings on the degradation mechanism under aging conditions are not just necessary, but also crucial for their satisfactory application. The aim of the study was a detailed and comprehensive evaluation of the aging processes of commercial ELASTOSIL® LR 3842/50 A/B, considering structural changes based on thermal analysis accompanied by mass spectroscopy, X-ray analysis, and infrared spectroscopy. The aging process was carried out at 125 °C and 175 °C, without and with 11 kg of loading. The obtained results showed that the aging of PDMS increased their thermal stability. It was the most visible for PDMS aging at 175 °C under load. It was attributed to secondary crosslinking and the post-curing process. Observed changes in polymer structure did not indicate its degradation. This is a significant finding, especially considering that a temperature of 175 °C is close to the critical temperature given by the producer (180 °C), above which the use of stabilizing agents is recommended.
Design of Composite N-Doped Carbon Nanofiber/TiO2/Diatomite Separator for Lithium–Sulfur Batteries
Authors: Xiao Wenjie , Wu Xiaoyu , Shu Yang , Zha Yitao , Liu Sainan
Published: November 2024

Lithium–sulfur batteries (LSBs) exhibit high theoretical specific capacities, abundant resource reserves, and low costs, making them promising candidates for next-generation lithium-ion batteries (LIBs). However, significant challenges, such as the shuttle effect and volume expansion, hinder their practical applications. To address these issues, this study introduces a unique intermediate layer comprising N-doped carbon nanofiber/TiO2/diatomite (NCNF/TiO2/DE) from the perspective of membrane modification. The intermediate layer comprises nitrogen-doped titanium dioxide/carbon nanofiber (NCNF/TiO2) materials, with diatomite filling the fiber gaps. This forms a three-dimensional (3D) conductive network that provides ample space for sulfur volume expansion and numerous adsorption active sites, thereby accelerating electrolyte penetration and lithium-ion diffusion. These features collectively contribute to the outstanding electrochemical performance of the battery. At 0.1 C, the NCNF/TiO2/DE-800-coated separator battery achieved a first-cycle discharge specific capacity of 1311.1 mAh g−1, significantly higher than the uncoated lithium–sulfur battery (919.6 mAh g−1). Under varying current densities, the NCNF/TiO2/DE-800 material demonstrates good electrochemical reversibility and exhibits high lithium-ion diffusion rates and low charge-transfer resistance. Therefore, this study provides an advanced intermediate layer material that enhances the electrochemical performance of lithium–sulfur batteries.
Effect of Deformed Prior Austenite Characteristics on Reverse Phase Transformation and Deformation Behavior of High-Strength Medium-Mn Steel
Authors: Dong Ying , Zhang Jingwen , Liu Tao , Ma Mingxing , Zhu Lei , Zhu Chengjun , Du Linxiu
Published: November 2024

In this study, microstructure evolution during prior austenite decomposition and reverse phase transformation processes was revealed in a high-strength medium-Mn steel. Furthermore, the relationship between deformed prior austenite characteristics and deformation behavior was studied. The results indicated that the recovery and recrystallization of the deformed prior austenite were significantly inhibited during hot rolling in the non-recrystallized zone, the grain size was obviously refined along the normal direction (ND), and that the strain hardening of prior austenite via hot deformation could increase the resistance of shear transformation, resulting in the preservation of high-density lattice defects in the quenched martensite matrix. Before the nucleation of intercritical austenite, the dislocation and grain boundary can provide fast diffusion paths for C and Mn, and the enrichment of C and Mn before intercritical austenite formation can reduce the critical temperature of ferrite/austenite transformation. The nucleated sites and driving force for intercritical austenite were strongly increased by rolling in the non-recrystallization region. The resistance of crack propagation was found to be enhanced by the sustained transformation-induced plasticity (TRIP) effect (via retained austenite with different stability) and for the laminated microstructure, the optimum properties were obtained as being a combination of yield strength of 748 MPa, tensile strength of 952 MPa, and total elongation of 26.2%.
Amorphous Carbon Film as a Corrosion Mitigation Strategy for Stainless Steel in Molten Carbonate Salts for Thermal Energy Storage Applications
Authors: Morales Miguel , Rezayat Mohammad , Mateo Antonio
Published: November 2024

Ternary carbonate salts (Li2CO3-Na2CO3-K2CO3) are promising heat transfer fluids to increase the efficiency of the electric power in concentrated solar power (CSP) technology. However, the corrosion produced at high operating temperatures is a key challenge to tackle for employing cost-effective steels as construction materials in CSP. In this work, the use of stainless steels with amorphous carbon was investigated, for the first time, as a surface modification method to mitigate the corrosion of structural CSP materials by molten salts. In doing so, an amorphous carbon (a-C) film of 100 nm in thickness was deposited on the 301LN stainless steel’s surface by the carbon thread evaporation technique. The corrosion behavior of the 301LN was assessed in carbonate salt at 600 °C for 1000 h. This film decomposed forming carbide layers, contributing to corrosion mitigation due to the generation of denser oxide layers, decreasing the Li+ diffusion through the stainless steel.
Fabrication of Mid-Infrared Porous Anodic Alumina Optical Microcavities via Aluminum Anodization
Authors: Białek Ewelina , Gruszczyńska Weronika , Włodarski Maksymilian , Liszewska Malwina , Norek Małgorzata
Published: November 2024

This study reports the production of mid-infrared (MIR) porous anodic alumina (PAA)-based microcavities with tunable optical quality. The spectral position of the cavity resonance peak (λC), along with its intensity (IR) and Q-factor, varies depending on the geometric positioning of the cavity layer within the multilayer stack of alternating low- and high-porosity layers, as well as the type of cavity produced—either by high voltage (CvH-type) or low voltage (CvL-type) pulses. In most cases, PAA microcavities with CvH-type cavity layers exhibited superior light confinement properties compared to those with CvL-type cavities. Additionally, shifting the cavity layer from the center toward the edges of the multilayer stack enhanced the intensity of the resonance peak. For PAA microcavities with CvH-type cavity layers, the highest intensity (IR = 53%) and the largest Q-factor (Q = 31) were recorded at λC of around 5.1 µm. The anodization approach used in this study demonstrates significant potential for designing PAA-based microcavities with high optical performance in the MIR spectral region, especially with further refinement of electrochemical parameters. These findings pave the way for the development of new photonic materials specifically tailored for the MIR spectral range, broadening their applications in various optoelectronic and sensing technologies.
Miniaturized Shear Testing: In-Plane and Through-Thickness Characterization of Plywood
Authors: Tuninetti Víctor , Sandoval Moisés , Cárdenas-Ramírez Juan Pablo , Oñate Angelo , Miranda Alejandra , Soto-Zúñiga Paula , Arnett Michael , Leiva Jorge , Cancino Rodrigo
Published: November 2024

This study addresses the challenges associated with conventional plywood shear testing by introducing a novel miniaturized shear test method. This approach utilizes a controlled router toolpath for precise sample fabrication, enabling efficient material use and data acquisition. Miniaturized samples, designed with double shear zones, were tested for τxy, τxz, and τyz configurations using a universal testing machine. Results revealed a mean ultimate shear strength ranging from 5.6 MPa to 7.3 MPa and a mean shear modulus ranging from 0.039 GPa to 0.095 GPa, confirming the orthotropic nature of plywood. The resulting shear behavior was determined with stress–strain curves correlated with failure patterns. The miniaturized tests effectively captured the material’s heterogeneous behavior, particularly at smaller scales, and demonstrated consistent load-bearing capacity even after substantial stress reduction, suggesting suitability for bracing applications. This method allows for increased sample sizes, facilitating robust data collection for developing and validating finite element models. Future work will focus on evaluating the scalability of the observed orthotropic behavior and data scatter at larger scales and assessing the potential for this method to replace conventional full-scale plywood shear testing.
Effect of Precipitation-Free Zone on Fatigue Properties in Al-7.02Mg-1.98Zn Alloys: Crystal Plasticity Finite Element Analysis
Authors: Chen Xin , Zheng Xiaoyu , Pan Meichen , Liu Yuling , Kong Yi , Hartmaier Alexander , Li Liya , Du Yong
Published: November 2024

Age-strengthened aluminum alloys, as important lightweight structural materials, have significantly lower fatigue properties compared to non-age-strengthened aluminum alloys. In this study, the polycrystalline models containing precipitation-free zones (PFZ) were constructed by secondary development of the traditional polycrystalline model by modifying the mesh file. Polycrystalline finite element simulations of peak age-treated Al-7.02Mg-1.98Zn alloys were carried out with this model. The results demonstrate that the PFZ’s presence markedly reduces the alloy’s yield strength and a substantial stress concentration occurs adjacent to the PFZ, generating significant compressive stresses at the PFZ. Under cyclic loading, the maximum strain energy dissipation in the model containing the PFZ far exceeds that observed in the conventional polycrystalline model, and the strain energy dissipation observed in the PFZ is significantly higher than that at other locations. This indicates that the PFZ is the main region for fatigue crack initiation. In addition, the introduction of a rotation factor to simulate the inhomogeneous rotation within the grain reveals that the additional stress concentration in the PFZ introduced by the aluminum alloy-forming process further increases the fatigue crack initiation driving force.
Nanocrystalline/Amorphous Tuning of Al–Fe–Nb (Mn) Alloy Powders Produced via High-Energy Ball Milling
Authors: Oanh Nguyen Thi Hoang , An Dao Truong , Viet Nguyen Hoang
Published: November 2024

The demand for advanced Al-based alloys with tailored structural and magnetic properties has intensified for applications requiring a high thermal stability and performance under challenging conditions. This study investigated the phase evolution, magnetic properties, thermal stability, and microstructural changes in the Al-based alloys Al82Fe16Nb2 and Al82Fe14Nb2Mn2, synthesized via mechanical alloying (MA), using stearic acid as a process control agent. The X-ray diffraction results indicated that Al82Fe16Nb2 achieved a β-phase solid solution with 13–14 nm crystallite sizes after 5 h of milling, reaching an amorphous state after 10 h. In contrast, Al82Fe14Nb2Mn2 formed a partially amorphous structure within 10 h, with enhanced stability with additional milling. Magnetic measurements indicated that both alloys possessed soft magnetic behavior under shorter milling times (1–5 h) and transitioned to hard magnetic behavior as amorphization progressed. This phenomenon was associated with a decrease in saturation magnetization (Ms) and an increase in coercivity (Hc) due to structural disorder and residual stresses. Thermal stability analyses on 10 h milled samples conducted via differential scanning calorimetry showed exothermic peaks between 300 and 800 °C, corresponding to phase transformations upon heating. Post-annealing analyses at 550 °C demonstrated the presence of phases including Al, β-phase solid solutions, Al₁3Fe₄, and residual amorphous regions. At 600 °C, the Al3Nb phase emerged as the β-phase, and the amorphous content decreased, while annealing at 700 °C fully decomposed the amorphous phases into stable crystalline forms. Microstructural analyses demonstrated a consistent reduction in and homogenization of particle sizes, with particles decreasing to 1–3 μm in diameter after 10 h. Altogether, these findings highlight MA’s effectiveness in tuning the microstructure and magnetic properties of Al–Fe–Nb (Mn) alloys, making these materials suitable for applications requiring a high thermal stability and tailored magnetic responses.
A Statistical Assessment of Drilling Effects on Glass Fiber-Reinforced Polymeric Composites
Authors: Martins Ana , Carvalho Alda , Bragança Ivo M. F. , Barbosa Inês C. J. , Barbosa Joaquim Infante , Loja Maria A. R.
Published: November 2024

Fiber-reinforced composites are extensively used in many components and structures in various industry sectors, and the need to connect and assemble such types of components may require drilling operations. Although drilling is a common machining process; when dealing with fiber-reinforced composite materials, additional and specific problems may arise that can com-promise mechanical integrity. So, the main goal of this work is to assess how various input variables impact two main outcomes in the drilling process: the exit-adjusted delamination factor and the maximum temperature on the bottom surface where the drilling tool exits. The input variables include the type of drilling tools used, the operating speeds, and the thickness of the plates being drilled. By using Analysis of Variance (ANOVA), the analysis aims to identify which factors significantly influence damage and exit temperature. The results demonstrate that the influence of tools and drilling parameters is critical, and those selections impact the quality of the hole and the extent of the induced damage to the surrounding area. In concrete, considering the initially selected set of tools, the BZT03 tool does not lead to high-quality holes when drilling medium- and high-thickness plates. In contrast, the Dagger tool shows potential to reduce exit hole damage while also lowering temperature.
Effects of Postweld Heat Treatment on Interfacial Behavior and Mechanical Properties of Joints Welded with Cu/Ni-Cr Alloy
Authors: Zhang Wanpeng , Xie Hang , Yu Xiaoquan , Zhang Jingang , Zhou Chao , Song Hongbing , Huang Jiankang
Published: November 2024

Welded cable composed of nickel–chromium (Ni-Cr) alloy and copper is a crucial component in the resistance heating technology used for heavy oil production. Tungsten inert gas (TIG) welding was employed to join the copper and Ni-Cr alloy using copper filler wire, and the stability of the welded joint was analyzed under high-temperature service conditions. We examined the changes in the microstructure and properties of the welded joint after postweld heat treatment (PWHT) at 600 °C for 3, 6, and 12 days. The results showed that the welded joint was appropriately formed, with fractures occurring in the copper substrate. The average tensile strength of the welded joint was 240 MPa. The copper and nickel dissolved into each other, forming a Cu0.81Ni0.19 strengthening phase. A columnar crystal diffusion layer formed at the interface between the Ni-Cr alloy and the fusion zone after welding. Grain boundary migration promoted the continuous growth in the columnar crystals as the PWHT duration increased, eliminating the microdefects and inhomogeneities caused by welding. The microhardness progressively decreased from the Ni-Cr alloy side to the copper side. However, the nanoindentation results at the Ni-Cr fusion line initially decreased and then increased with increasing PWHT duration, which contrasted the overall hardness trend observed across the joint after PWHT.
Mg/Si- and Ag-Doped Carbon-Based Media Rainwater Filtration System for Multiple Pollutants Removal
Authors: Yoon So Yeon , Kim Hyeseong , Valiyaveettil Basheer Reneesha , Abd Rahman Nurhaslina , Jang Seok Byum , Wong Kien Tiek , Moon Deok Hyun , Choong Choe Earn , Jang Min
Published: November 2024

In this study, the removal performances of a multi-pollutant elimination cartridge system (MPECS) composed of palm shell waste-based activated carbon (PSAC), magnesium (Mg)/silicon (Si)-doped PSAC (Mg/Si-PSAC), and silver (Ag)-doped PSAC (Ag-PSAC) for heavy metals, organic pollutants, and Escherichia coli were investigated. Mg/Si impregnation significantly improved heavy metal removal using PSAC by increasing the surface area and adding more sorption sites to the magnesium silicate nanolayer. Fixed-bed column experiments showed that the MPECS column outperformed PSAC and commercial activated carbon (DJAC), with a 1.5 to 2.0 times higher E. coli removal and a higher removal of organic pollutants and heavy metals. The MPECS column, with its disinfection ability and adsorption of heavy metals and organic matter, is a promising system for removing multiple pollutants from rainwater.
Polyurethane Nanocomposites with Open-Cell Structure Modified with Aluminosilicate Nano-Filler
Authors: Paciorek-Sadowska Joanna , Borowicz Marcin , Datta Janusz , Piszczyk Łukasz , Kosmela Paulina , Zarzyka Iwona
Published: November 2024

Nanocomposite flexible polyurethane foams (nFPUfs) were obtained by modifying the polyurethane formulation by adding a halloysite nano-filler in the amount of one to five parts by weight per hundred parts of used polyol (php). Flexible polyurethane (PU) foams with an open-cell structure and with a beneficial SAG factor were obtained. Premixes with nano-filler had a lower reactivity than the reference PU system. This favored the production of smaller cells, but with a more rounded shape in comparison with the REF foam without the nano-filler. During the study, the morphology and physical and mechanical properties were characterized, including apparent density, compressive stress, rebound flexibility, SAG factor, closed-cell content, and thermal stability, and compared with the properties of the unmodified reference foam. Scanning electron microscopy (SEM) showed that the cell structures of all prepared foams were open, and the cell size decreased with increasing nano-filler content. Apparent densities, SAG factors and rebound flexibilities of the foams increased with the increase of nano-filler content, while the resistance to permanent deformation showed the opposite trend. The proper selection of raw materials and optimally developed polyurethane formulations allow for obtaining environmentally friendly foams with favorable functional properties, taking into account price and the needs of sustainable development in the synthesis of flexible foams dedicated to the upholstery industry.
Inorganic Acid Resistance Performances of Magnesium Phosphate Cement: A Two-Year Observation
Authors: Sun Huaqiang , Zhuo Kanghong , Lin Tianzhu , Zhuang Shusen , Kang Sixiang , Ma Congcong , Deng Lingxi
Published: November 2024

Magnesium phosphate cement (MPC), a cementitious material that hardens through an acid–base reaction, is theoretically expected to exhibit strong acid resistance. However, studies on the durability of MPC in acidic environments remain limited. This study aims to systematically evaluate the acid resistance of MPC in common inorganic acid solutions across various pH levels. By measuring changes in compressive strength, mass loss, apparent changes, pH changes, and the microstructure evolution of MPC under acidic conditions, the mechanisms and influencing factors of its acid resistance are revealed. The results indicate that at pH levels of 1.0 and 2.0, MPC’s resistance to H2SO4 and HCl erosion is markedly superior compared to its performance against H3PO4, as evidenced by compressive strength retention, mass loss, and visible erosion. At pH levels above 2.0, MPC demonstrates robust resistance to all tested corrosive media, with compressive strength retention ranging from 68.9% to 86.9%, irrespective of the acid source. Although new corrosion products form in these acidic environments, the adverse effects of NH4/P loss from struvite, along with the redissolution of corrosion products due to their higher solubility, increase porosity and subsequently reduce the mechanical strength. Nevertheless, considering that strength retention is significantly higher than that of other cement-based materials reported in the literature, MPC still exhibits good acid resistance and is suitable for environments requiring enhanced resistance to acid corrosion.
Topology Optimization of Periodic Structures Subject to Self-Weight Loading Using a Heuristic Method
Authors: Tajs-Zielińska Katarzyna
Published: November 2024

This paper deals with the actual and challenging process of the optimal design of topologies of periodic structures taking into account the design-dependent loads. The topology formulation used in this paper minimizes the compliance value of the structure and is subject to a total volume constraint while maintaining a periodic pattern and self-weight load. This combination represents a promising and original contribution to the field of ongoing research, although it is not yet widely recognized. This paper aims to fill this gap by presenting the first results of numerical optimization tests. The redistribution of material within a design domain is governed by the rules of Cellular Automata, a locally oriented optimization tool that can be applied to all types of structural optimization, including topology optimization. The technique has been demonstrated by numerical tests on two- and three-dimensional examples. The calculations were performed for different types of periodic schemes. The optimized structures did not show the checkerboard effect or the presence of residual gray elements in the final topologies. The strategy used in this paper ensures connectivity between periodic subdomains without imposing additional conditions on the algorithm.
PDA Nanoparticle-Induced Lubricating Film Formation in Marine Environments: An Active Approach
Authors: Zou Xinqi , Ge Zhenghao , Wang Chaobao , Xi Yuyang
Published: November 2024

The low viscosity of water-lubricated films compromises their load-bearing capacity, posing challenges for practical application. Enhancing the lubrication stability of these films under load is critical for the successful use of seawater-lubricated bearings in engineering. Polydopamine (PDA) shows great potential to address this issue due to its strong bio-inspired adhesion and hydration lubrication properties. Thus, PDA nanoparticles and seawater suspensions were synthesized to promote adhesive lubricating film formation under dynamic friction. The lubrication properties of PDA suspensions were evaluated on Cu ball and ultra-high molecular weight polyethylene (UHMWPE) tribo-pairs, with a detailed comparison to seawater. The results show PDA nanoparticles provide excellent adhesion and lubrication, enhancing the formation of lubricating films during friction with seawater. Under identical conditions, PDA suspensions demonstrated the lowest friction coefficient and minimal wear. At 3 N, friction decreased by 56% and wear by 47% compared to distilled water. These findings suggest a novel strategy for using PDA as a lubricant in seawater for engineering applications.
Genomic Analysis of Advanced Phyllodes Tumors Using Next-Generation Sequencing and Their Chemotherapy Response: A Retrospective Study Using the C-CAT Database
Authors: Suzuki Shuhei , Saito Yosuke
Published: November 2024

Background and Objectives: Phyllodes tumors are rare breast neoplasms with limited therapeutic options and poorly understood molecular characteristics. This study aimed to analyze genomic alterations and treatment outcomes in advanced phyllodes tumors using Japan’s national clinical genomic testing registry (C-CAT database) to identify potential therapeutic targets and predictive markers. Materials and Methods: We conducted a retrospective analysis of 60 phyllodes tumor cases from 80,329 patients registered in the C-CAT database between June 2019 and August 2024. Comprehensive genomic profiling was performed using multiple platforms including FoundationOne CDx, NCC OncoPanel, and other approved tests. Treatment responses were evaluated according to RECIST criteria, and pathogenic variants were assessed using established databases including ClinVar and OncoKB. Results: The cohort’s median age was 54 years (range: 13–79), with TERT promoter variants (70%), MED12 (52%), and TP53 (50%) mutations being the most frequent alterations. Forty patients received first-line chemotherapy, predominantly anthracycline-based regimens (n = 29). Although not reaching statistical significance, cases with CDKN2A and TERT alterations showed trends toward treatment resistance (OR > 3.0). One patient with a high tumor mutational burden (37/Mb) responded to pembrolizumab. Potential germline variants were identified in two cases (3.3%), involving MSH6 and TP53 alterations. Notably, no cases with CDKN2B alterations demonstrated treatment response (p = 0.09). Conclusions: Our findings suggest distinct molecular patterns in phyllodes tumors compared to other soft tissue sarcomas, with potential implications for treatment selection. The identification of specific genetic alterations associated with treatment resistance may guide therapeutic decision-making, while the presence of actionable mutations in select cases indicates potential opportunities for targeted therapy approaches.
Petrogenesis of the Shibaogou Mo-W-Associated Porphyritic Granite, West Henan, China: Constrains from Geochemistry, Zircon U-Pb Chronology, and Sr-Nd-Pb Isotopes
Authors: Qiu Zhiwei , Zhou Zhenju , Qi Nan , Huang Pocheng , Yao Junming , Feng Yantao , Chen Yanjing
Published: November 2024

The Shibaogou pluton, located in the Luanchuan orefield of western Henan Province in China, is a typical porphyritic granite within the Yanshanian “Dabie-type” Mo metallogenic system. It is mainly composed of porphyritic monzogranite and porphyritic syenogranite. Zircon U-Pb dating results indicate emplacement ages of 150.1 ± 1.3 Ma and 151.0 ± 1.1 Ma for the monzogranite and 148.1 ± 1.0 Ma and 148.5 ± 1.3 Ma for the syenogranite. The pluton is characterized by geochemical features of high silicon, metaluminous, and high-K calc-alkaline compositions, enriched in Rb, U, Th, and Pb, and exhibits high Sr/Y (18.53–58.82), high (La/Yb)N (9.01–35.51), and weak Eu anomalies. These features indicate a source region from a thickened lower crust with garnet and rutile as residual phases at depths of approximately 40–60 km. Sr-Nd-Pb isotopic analyses suggest that the magmatic source is mainly derived from the Taihua and Xiong’er Groups of the Huaxiong Block, mixed with juvenile crustal rocks from the Kuanping and Erlangping Groups of the North Qinling Accretion Belt. Combined with geological and isotopic characteristics, it is concluded that the Shibaogou pluton formed during the compression–extension transition period associated with the collision between the Yangtze Block and the North China Craton, reflecting the complex partial melting processes in the thickened lower crust. The present study reveals that the magmatic–hydrothermal activity at Shibaogou lasted approximately 5 Ma, showing multi-phase characteristics, further demonstrating the close relationship between the pluton and the Mo-W mineralization.
Caffeine Enhances Some Aspects of Physical Performance in Well-Trained Hammer and Discus Throwers
Authors: Gallo-Salazar César , Del Coso Juan , Lara Beatriz , Aguilar-Navarro Millán , Giráldez-Costas Verónica , Areces Francisco , Revuelta Carlos , Gutiérrez-Hellín Jorge , Salinero Juan José
Published: November 2024

Background: Caffeine is a widely recognized ergogenic aid for enhancing exercise performance. However, its effect on throwing performance has been less studied, yielding contradictory results. Objectives: The main aim of the study was to analyze the potential ergogenic effects of a moderate dose of caffeine (3 mg·kg−1 body mass) on vertical jump performance and throwing distance during a simulated competition in trained discus and hammer throwers. Methods: In a randomized, counterbalanced, and repeated measures design, 14 well-trained throwers (9 hammer throwers and 5 discus throwers; age 24.8 ± 6.3 years old, training 14.9 ± 5.0 h per week, competing experience 10.5 ± 6.1 years) performed a countermovement jump (CMJ) test, a modified throw, and a complete throw after the ingestion of 3 mg·kg⁻¹ body mass of caffeine or a placebo. Each participant performed three maximal-effort valid modified throws of his/her respective event (i.e., hammer or discus throw), plus three maximal-effort valid official throws (up to five tries, respectively, in case any attempt was called as foul). Throwing distance was measured according to World Athletics regulations using a metal tape, while release speed was assessed with a radar device. After the performance measurements, participants completed a form about side effects prevalence. Results: Caffeine, compared to placebo, increased throw distance (3.0 ± 5.1%, p = 0.048) and speed release (5.7 ± 8.7%, p = 0.03) for the complete throw, and distance (3.6 ± 4.4%, p = 0.01) and speed release (4.8 ± 7.4 %, p = 0.01) for the modified throw. Caffeine ingestion did not significantly improve jump height (1.1 ± 4.3%, p = 0.28), although it improved force and power on braking and the propulsive phases of the CMJ (p < 0.05). Caffeine only increased the prevalence of activeness (p < 0.05). Conclusions: An acute moderate dose of caffeine enhanced hammer and discus throw performance in well-trained throwers during a simulated competitive setting, with minimal adverse side effects.
A Snapshot of Vitamin D Status, Performance, Blood Markers, and Dietary Habits in Runners and Non-Runners
Authors: Pegreffi Francesco , Donati Zeppa Sabrina , Gervasi Marco , Fernández-Peña Eneko , Annibalini Giosuè , Bartolacci Alessia , Formiglio Eugenio , Agostini Deborah , Barbato Claudia , Sestili Piero , Patti Antonino , Stocchi Vilberto , Bellomo Rosa Grazia
Published: November 2024

Background: Vitamin D can influence athletic performance and infection risk. This study aimed to investigate vitamin D status, hematochemical factors, anthropometric and performance parameters, and dietary habits in runners (n = 23) and sedentary healthy individuals (non-runners, n = 22) during the autumn season. Methods: Both groups had their serum 25-Hydroxyvitamin D (ng/mL) levels, blood and performance parameters, and dietary habits measured. Results: Serum 25-Hydroxyvitamin D levels were significantly lower in non-runners (runners: males 30.0 ± 5.6, females 31.2 ± 5.2 vs. non-runners: males, 22.8 ± 6.5, females 24.7 ± 6.5 ng/mL, p < 0.001). White blood cells, monocyte, and neutrophil levels were higher in non-runners for both males and females. Among the subjects, 23 had optimal vitamin D levels (>29 ng/mL), while 22 had insufficient/deficient levels (<29 ng/mL), with a higher prevalence of insufficiency in non-runners compared to runners (63.6% vs. 34.8%; p = 0.053). Maximal isometric force and jump height were equal in both groups, but VO2max was higher in runners. Linear regression analysis identified monocyte count as the only predictor of vitamin D levels for both males (y = −24.452 x + 40.520; R2 = 0.200; p = 0.015) and females (y = −33.409 x + 45.240; R2 = 0.368; p = 0.003). Conclusions: This study highlights significant differences in vitamin D status between runners and non-runners, with runners exhibiting higher serum 25-Hydroxyvitamin D levels, although this finding is likely due to the increased sun exposure that runners receive. It also provides valuable insights into the vitamin D status of healthy young sedentary individuals and runners, enhancing the understanding of how physical activity influences vitamin D levels.
Possible Interaction Between Physical Exercise and Leptin and Ghrelin Changes Following Roux-en-Y Gastric Bypass in Sarcopenic Obesity Patients—A Pilot Study
Authors: Mendes Cláudia , Carvalho Manuel , Bravo Jorge , Martins Sandra , Raimundo Armando
Published: November 2024

Introduction: Leptin and ghrelin are two hormones that play a role in weight homeostasis. Leptin, which is produced primarily by adipocytes and is dependent on body fat mass, suppresses appetite and increases energy expenditure. Conversely, ghrelin is the “hunger hormone”, it stimulates appetite and promotes fat storage. Bariatric surgery significantly alters the levels and activity of these hormones, contributing to weight loss and metabolic improvements. Clarifying the interplay between bariatric surgery, weight loss, physical exercise, leptin, and ghrelin is essential in developing comprehensive strategies for optimizing the long-term outcomes for candidates who have undergone bariatric surgery, especially for sarcopenic patients. Methods: This was a randomized controlled study with two groups (n = 22). The patients in both groups had obesity and sarcopenia. A Roux-en-Y-gastric bypass (RYGB) procedure was performed on all patients. The intervention group participated in a structured exercise program three times per week, beginning one month after surgery and lasting 16 weeks. Patient assessment was performed before surgery (baseline) and after the completion of the exercise program. The control group received the usual standard of care and was assessed similarly. Results: After surgery, weight, BMI, and lean mass decreased significantly in both groups between the baseline and the second assessment. Leptin levels were not significantly different between baseline and the second assessment in the physical exercise group, but were significantly lower in the control group (p = 0.05). Ghrelin levels increased over time in both groups, but the differences were not significant. When we associated leptin (the dependent variable) with weight (the independent variable), we found that lower weight was associated with lower leptin levels. A similar relationship was also observed between the leptin and sarcopenia parameters (muscle strength and mass), as well as in the bone health parameters (bone mineral density and t-score). Higher ghrelin levels were significantly associated with higher t-scores and z-scores (p < 0.05). Conclusion: Exercise has been shown to have a significant effect on leptin and ghrelin levels after bariatric surgery. By incorporating regular physical activity into their lifestyle, bariatric patients can optimize their weight loss outcomes and improve their overall health. After the physical exercise protocol, patients in the intervention group revealed more established leptin levels, which may indicate a protected pattern concerning decreased leptin levels. An unfavorable profile was evidenced, according to which greater weight loss, sarcopenia, and osteoporosis were associated with lower leptin levels.
Assessment of the General Nutrition Knowledge of Students from the University of Novi Sad (Vojvodina, Serbia)
Authors: Ilić Miloš , Ilibašić Danica , Pang Huiwen , Vlaški Tomislav , Jovičić-Bata Jelena , Grujičić Maja , Novaković Budimka
Published: November 2024

Background: Healthy nutrition is necessary for a good quality of life and reduction in the risk of developing diseases. Research indicates that students do not usually have healthy eating habits. Knowledge about nutrition, dietary guidelines, food groups and the nutrients they contain, the selection and adequate preparation of food, and the health consequences of unhealthy nutrition can influence the eating habits of students. Until recently, no research had been conducted on university-level students’ nutrition knowledge in Serbia. The aim of this study was to determine the nutrition knowledge of students from the University of Novi Sad (Vojvodina, Serbia) in relation to gender, year of study, academic field of study, and nutritional status. Methods: A cross-sectional study was conducted in the period from December 2021 to July 2022, on 898 students (72.9% female and 27.1% male, with an average age of 22.87 ± 3.092). An online survey questionnaire was used as the research instrument. An assessment of nutrition knowledge was performed using the General Nutrition Knowledge Questionnaire (GNKQ) for the following domains: dietary recommendations; food groups and the nutrients they contain; healthy food choices; and diet, disease and weight associations. Results: Significant differences in students’ assessed knowledge levels were determined across various domains of healthy nutrition. The highest level of nutrition knowledge was in healthy food choices, and the lowest was in understanding food groups and nutrient composition. The total determined knowledge about healthy nutrition correlated most with self-assessed knowledge of food groups, and least with knowledge of dietary recommendations. Female gender and higher years of study were associated with higher nutrition knowledge. Students from the Faculty of Medicine had the highest nutrition knowledge, followed by students from the Faculty of Technology and the Faculty of Science, compared to students from other faculties. Conclusions: Our findings highlight the need for targeted interventions aimed at improving students’ understanding of specific nutritional concepts, ultimately empowering them to make informed dietary decisions for lifelong health and wellbeing.
The Impact of a Ketogenic Diet on Late-Stage Pancreatic Carcinogenesis in Mice: Efficacy and Safety Studies
Authors: Cortez Natalia E. , Bacha Tarek A. , Ead Aya Samir , Rodriguez Lanzi Cecilia , Lacroix Cassandra , Franceschetti Anais , Hong Brian V. , Matsukuma Karen , Mackenzie Gerardo G.
Published: November 2024

Background: High-fat diets (HFDs) have been associated with an increased risk of pancreatic cancer. In contrast, ketogenic diets (KDs) have been shown to display anti-tumor characteristics. The objective of this work was to evaluate the efficacy of a KD on late-stage pancreatic carcinogenesis in a genetically modified mouse model of pancreatic cancer [LSL-KrasG12D/+; Ptf1-Cre (KC) mice], as well as its liver safety, and to compare it to that of an HFD. Methods: Six-month-old female and male KC mice were randomly allocated to either a control diet (CD) (%kcal: 20% fat, 15% protein, 65% carbohydrates), an HFD (%kcal: 40% fat, 15% protein, 45% carbohydrate) or a KD (%kcal: 84% fat, 15% protein, 1% carbohydrate) and fed these diets for 6 months. Results: HFD-fed, but not KD-fed, mice showed a 15% increase in body weight, plus elevated serum insulin (2.4-fold increase) and leptin (2.9-fold increase) levels, compared to CD-fed mice. At the pancreas level, no differences in pancreatic cancer incidence rates were observed among the diet groups. Regarding the liver safety profile, the HFD-fed mice had higher serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP), when compared to the CD and KD groups. In addition, upon histologic examination, an HFD, but not a KD, showed a ~2-fold increase in both macro- and microsteatosis, as well as 35% and 32% higher levels of TLR4 and NF-κB activation, respectively, compared to CD-fed mice. Conclusions: In summary, although a KD intervention alone did not prevent pancreatic carcinogenesis, our data suggests that a KD modulates insulin signaling and hepatic lipid metabolism, highlighting its beneficial effects on healthspan and liver function when compared to an HFD.
Dietary Challenges in Children with Gluten-Related Disorders: A Study on Food Neophobia
Authors: Nogueira Firme Julyana , dos Santos Emanuele Batistela , Zandonadi Renata Puppin , Nakano Eduardo Yoshio , Botelho Raquel Braz Assunção
Published: November 2024

Background/Objectives: Food neophobia (FN) in childhood is characterized by resistance to new foods, potentially impairing health and diet quality and impacting physical and mental development. Adequate nutrition in early childhood is crucial to preventing future problems. FN demands special attention, especially in cases of gluten-related disorders (GRD), due to the risks associated with restrictive diets and food allergies. The objective of this study was to investigate and classify the prevalence of FN among Brazilian children aged 4 to 11 years with GRD. Methods: For this cross-sectional study, a questionnaire validated in Portuguese, with 25 items, assessed FN in three domains: general FN, FN of fruits, and FN of vegetables. Data were collected via Google Forms. Results: Of 209 children with GRD, the majority were female, 83.7% were diagnosed with celiac conditions, 81.3% followed a diet, and 43.1% had moderate total food neophobia. Brazilian children with GRD have a moderate prevalence of food neophobia. General and vegetable neophobia predominate, while fruit FN is lower. Girls exhibit greater neophobia towards vegetables. Conclusions: Neophobia does not vary with age, suggesting the persistence of the behavior and potential nutritional challenges in adult life. Differentiated attention to this population is essential to minimize long-term impacts.
RNA-Seq Analysis of Pubertal Mammary Epithelial Cells Reveals Novel n-3 Polyunsaturated Fatty Acid Transcriptomic Changes in the fat-1 Mouse Model
Authors: Buchanan Connor , Ashraf Rahbika , Hillyer Lyn , Tu Wangshu , Kang Jing , Subedi Sanjeena , Ma David
Published: November 2024

Background: The early exposure of nutrients during pubertal mammary gland development may reduce the risk of developing breast cancer later in life. Anticancer n-3 polyunsaturated fatty acids (n-3 PUFA) are shown to modulate pubertal mammary gland development; however, the mechanisms of action remain unclear. Prior work focused on effects at the whole tissue level, and little is known at the cellular level, such as at the level of mammary epithelial cells (MECs), which are implicated in cancer development. Methods: This pilot study examined the effects of lifelong n-3 PUFA exposure on the transcriptome by RNA-Seq in the isolated MECs of pubertal (6–8-week-old) female fat-1 transgenic mice capable of de novo n-3 PUFA synthesis. edgeR and DESeq2 were used separately for the differential expression analysis of RNA sequencing data followed by the Benjamani–Hochberg procedure for multiple testing correction. Results: Nine genes were found concordant and significantly different (p ≤ 0.05) by both the DESeq2 and edgeR methods. These genes were associated with multiple pathways, suggesting that n-3 PUFA stimulates estrogen-related signaling (Mlltl0, Galr3, and Nrip1) and a glycolytic profile (Soga1, Pdpr, and Uso1) while offering protective effects for immune and DNA damage responses (Glpd1, Garre1, and Rpa1) in MECs during puberty. Conclusions: This pilot study highlights the utility of RNA-Seq to better understanding the mechanistic effects of specific nutrients such as n-3 PUFA in a cell-specific manner. Thus, further studies are warranted to investigate the cell-specific mechanisms by which n-3 PUFA influences pubertal mammary gland development and breast cancer risk later in life.
Positive Changes in Body Composition and Profiles of Individuals with Diabetes 3 Years Following Laparoscopic Sleeve Gastrectomy in Japanese Patients with Obesity
Authors: Ozeki Yoshinori , Masaki Takayuki , Miyamoto Shotaro , Yoshida Yuichi , Okamoto Mitsuhiro , Gotoh Koro , Endo Yuichi , Inomata Masafumi , Shibata Hirotaka
Published: November 2024

Background and Objectives: We analyzed the changes in obesity, glucose metabolism, and body composition over a 3-year period in Japanese patients with obesity following laparoscopic sleeve gastrectomy (LSG). Methods: Body weight, parameters related to diabetes such as glycated hemoglobin (HbA1c), and electrical impedance analysis were used to assess body composition in forty-eight Japanese patients with obesity before surgery and 6 months, 1 year, 2 years, and 3 years after LSG. Results: At 6 months, 1, 2, and 3 years post-LSG, there were significant reductions in body weight, body mass index, blood pressure, fasting plasma glucose, triglyceride, and HbA1c levels. Six months after LSG, fat mass (FM), muscle mass (MM), and %FM all showed a decrease compared to pre-treatment values (all p < 0.05). FM and %FM remained in a decreased state until 3 years had passed. In contrast, %MM increased at 6 months post-LSG and was maintained up to 3 years post-LSG (all p < 0.05). Furthermore, changes in FM and %FM were associated with changes in body weight and A1C. In contrast, change in %MM exhibited a negative correlation with body weight and A1C following LSG. Finally, multivariate regression analyses demonstrated that alterations in FM were independent factors affecting body weight in patients with obesity 3 years after LSG. Conclusions: We observed improvements in FM, fasting plasma glucose, and HbA1c levels over a 3-year period in Japanese patients after LSG. The reduction in FM and maintenance of %MM after LSG were suggested as possible links between the effects of LSG on obesity and diabetes over 3 years.
Fitness and Dietary Supplements: A Cross-Sectional Study on Food Practices and Nutrivigilance
Authors: Galman Aziz , Chikhaoui Mourad , Bouhrim Mohamed , Eto Bruno , Shahat Abdelaaty A. , Herqash Rashed N. , Lotfi Rachid , Belamgharia Hind , Daoudi Daoud , Kaddouri Morad , Dlimi Charaf , Alahyane Hassan , Liba Habiba , Reda Kachmar Mohamed , Boutoial Khalid
Published: November 2024

Background/Objectives: The use of dietary supplements (DSs) has become common among fitness enthusiasts, aiming to enhance performance, recovery, and overall well-being. Methods: A cross-sectional study was conducted in the city of Beni Mellal from April to July 2024, assessed dietary practices, motivations for supplement use, and associated adverse effects among 420 survey participants. Results: The majority of dietary supplement users were aged 25–64 and had higher education levels. Colopathy (67.38%) was the most common eating disorder, followed by digestive (59.46%), inflammatory, and rheumatic diseases (53.50%). Dietary supplementation prevalence was 88.1%, with proteins (60.81%), medicinal plants (45.13%), and vitamins (42.70%) being the most consumed. Key motivations included supporting muscle, bone, and joint strength (musculoskeletal) (83.78%) and enhancing heart and lung function for cardiorespiratory health (82.43%). However, 28% of protein users experienced adverse effects, such as myalgia, gastralgia, palpitations, and insomnia. Multivariate linear regression indicated a significant negative association of creatine with effectiveness (β = −0.485, p = 0.001). Conclusions: Overall, while the benefits of dietary and sports practices are evident, the adverse effects associated with protein supplements highlight the necessity for enhanced nutrivigilance and nutritional education to ensure safe supplements.