Search Results (14,220)

This study focuses on two significant factors shaping university students’ perception of environmental sustainability. Those are (a) personal values, measured by the Portrait Values Questionnaire (PVQ) and (b) the usage of and proficiency in information technology. Personal values have been widely used to analyze individual perspectives toward various issues, including environmental ones. As contemporary social arrangements include significant influences from social networks and mobile phone usage, overall engagement with technology becomes an essential factor affecting university student attitudes and behaviors. While the individual impact of those factors can be found in the extant literature, we look into their interaction concerning university student pro-environmental attitudes, measured by the Revised NEP (New Ecological Paradigm) Scale, and their environmental self-efficacy. Our sample comes from the population of undergraduate business and economics students from Central and Southeast Europe, specifically Slovenia, Croatia, Bosnia and Herzegovina, Serbia, and Montenegro. We discuss our findings in the context of previous studies from the same regions and consider the unique socio-economic factors. The research results address Sustainable Development Goals 4 (quality education), 12 (responsible consumption and production), and 13 (climate action) by analyzing the factors contributing to university student pro-environmental attitudes and their self-efficacy in the context of their information technology usage and proficiency. Full article

Background: The treatment of mandibular second molar (MM2) impaction presents a challenge for orthodontists and requires a surgical–orthodontic approach. This study aims to compare the effectiveness of two techniques for treating impacted MM2: a traditional technique using brass wire and a technique employing skeletal anchorage. Methods: Twelve MM2 with mesio-angular impaction, with an inclination angle between 25° and 40° and an impaction depth between 4 and 10 mm, were selected and randomly divided into two treatment groups. Patients in Group A were treated using the traditional brass wire technique, while those in Group B underwent treatment with a skeletal anchoring technique that utilized a miniscrew positioned in the retromolar region and an elastic sling chain. For both groups, treatment time and the influence of the disimpaction technique on oral health-related quality of life (OHRQoL) were evaluated using the short-form Oral Health Impact Profile (OHIP-14). Results: The results indicated an average treatment time of 168.67 ± 52.32 days for Group A and 76 ± 10.17 days for Group B, with a statistically significant difference (p-value = 0.0002). Regarding the impact on the patients’ OHRQoL, Student’s t-test did not reveal a statistically significant difference between the two groups at 3 and 7 days of follow-up. Conclusions: Both techniques are considered effective for the treatment of impacted MM2 (angulation 25–40°, depth 4–10 mm). The use of skeletal anchorage significantly reduces treatment times without negatively affecting OHRQoL. The results of this study should be confirmed by further studies with larger sample sizes. Full article

The main aim of this study is the concept of the magnet holder for the THz undulator utilized in the PolFEL superradiant light source. To achieve maximum flux at high K values (radiation frequencies ranging from 0.5 THz to 5 THz, and K values exceeding 3), it is necessary to use large permanent magnets with dimensions of 100 × 100 × 39.9 mm. For the above assumptions and parameters and specific requirements for magnet positioning, existing design solutions in the literature were found to be insufficient. The main challenges in the design of this holder included the following: (a) the unusually large size of the magnets, (b) requirements of wide-range calibration, and (c) large magnetic forces acting on each magnet, which can approach almost 4 kN. Taking into consideration these challenges, the prototype of the magnet holder was developed and manufactured. The paper presents the findings from both numerical and experimental studies aimed at validating the mechanical behavior and deformation of the proposed magnet holder. The measurements were conducted using two methods—traditional with the use of dial indicators and a novel approach based on the application of the Digital Image Correlation. The results from these numerical and experimental studies indicate that all specified requirements have been satisfactorily met. The study confirms the capability for accurate magnet positioning, demonstrating stable deformation of the holder under a magnetic load. Additionally, it was proved that the positioning of the magnets is both linear and repeatable, with calibration achievable within a range of at least +/−0.25 mm. Full article

This study aimed to investigate the relationship between the IL-28B SNP rs8099917 genotype, miRNA-122 expression, and the immune mechanism of ACR after LT using anti-HCV antibody calibration. A total of 45 patients with HCV received LT. IL-28B SNP rs8099917 genotyping was used to divide patients into TT and GT groups. The relative expression levels of miRNA-122 were calculated by quantitative PCR. Anti-HCV titers before and after LT were tracked to observe the relationship with ACR. The ACR rates were 27.6% for genotype TT and 62.5% for genotype GT, indicating a significantly higher rate in the GT group compared to the TT group (p = 0.024). In the rs8099917 genotype, TT was significantly associated with higher serum miRNA-122 levels than GT (p < 0.001). The TT group had significantly better outcomes than the GT group (p = 0.005). The Mann–Whitney U test showed significant differences in pre-LT and post-LT anti-HCV titers between the IL-28B genotypes (TT and GT) (p values of 0.006 and 0.027, respectively). These results suggested that the IL-28B rs8099917 genotype TT may play a significant role in modulating immune responses, both in terms of anti-HCV titers and the risk of ACR, possibly mediated through miRNA-122 levels. Full article

Background/Objectives: Neutrophils have recently gained significant attention due to their heterogeneity in tumor settings. The gene expression profiles of neutrophils from different tumor types are of great interest. Murine splenic neutrophils reflect the immune status of the organism and could be a source of tumor-associated neutrophils in tumor-bearing mice. However, information about appropriate reference genes for RT-qPCR analysis of murine neutrophils in the literature is lacking. The aim of this study was to identify stably expressed reference genes in murine splenic neutrophils. Methods: Bone marrow- and spleen-derived neutrophils were isolated from healthy C57Bl/6 and CBA/LacSto mice. Spleen-derived neutrophils were isolated from mice with Lewis lung carcinoma (LLC) and drug-resistant lymphosarcoma (RLS₄₀). RNA was isolated and used for RT-qPCR analysis of 10 selected reference genes. Analysis of reference gene stability was performed using four different algorithms (BestKeeper, NormFinder, geNorm, ΔCt method), and comprehensive ranking was constructed using RefFinder. Results: The Ct values for the reference genes were in the range of 16.73–30.83 with the highest expression levels observed for B2m and the lowest for Sdha. Differences in the stability ranking performed by different algorithms were observed; however, the overall ranking of the studied reference genes was as follows, from most to least stably expressed: Tbp, Hprt1, Ywhaz, B2m, Gapdh, Actb, Sdha, Eef2, Rack1, and Rpl13a. Using Tbp or Rpl13a for RT-qPCR data normalization significantly affected the interpretation of target gene expression. Conclusions: Tbp and Hprt1 are recommended reference genes for murine splenic neutrophils regardless of their activation status. Full article

Background and aims: We aimed to clarify the relationship between alanine aminotransferase (ALT) level and body composition in Japanese medical health checkups, especially in cases with ALT ≤ 30 IU/L (7569 men and 9497 women). Methods: We categorized our study cohort into four groups: type A (ALT value ≤ 10 IU/L), type B (11 ≤ ALT value ≤ 20 IU/L), type C (21 ≤ ALT value ≤ 30 IU/L) and type D (ALT value > 30 IU/L (ALT over 30)). We retrospectively compared body composition-related parameters (body mass index (BMI), waist circumference (WC), fat (F) index, fatty liver index (FLI), fat-free (FF) index and F-FF ratio) among the four types. Results: Type A/B/C/D in men and women was found in 262/3279/2107/1921 and 1549/5736/1495/717 (p < 0.0001). BMI, WC, F-index, FLI, FF index and F-FF ratio were all significantly stratified among the four types, regardless of whether they were male or female and over or under 50 years old. Conclusions: With a decrease in ALT level in medical health checkups, fat mass decreases, and F-FF ratio decreases, but a decrease in skeletal muscle mass cannot be overlooked. Full article

Double perovskite oxides with mixed ionic and electronic conductors (MIECs) have been widely investigated as cathode materials for solid oxide fuel cells (SOFCs). Classical Fe-based double perovskites, due to their inherent low electronic and oxygen ionic conductivity, usually exhibit poor electrocatalytic activity. The existence of various valence states of B-site ions modifies the material’s catalytic activity, indicating the possibility of the partial substitution of Fe by higher-valence ions. LaBaFe_2−xMo_xO_5+δ (x = 0, 0.03, 0.05, 0.07, 0.1, LBFM_x) is used as intermediate-temperature solid oxide fuel cell (IT-SOFC) cathode materials. At a doping concentration above 0.1, the Mo substitution enhanced the cell volume, and the lattice expansion caused the formation of the impurity phase, BaMoO₄. Compared with the parent material, Mo doping can regulate the oxygen vacancy concentration and accelerate the oxygen reduction reaction process to improve the electrochemical performance, as well as having a suitable coefficient of thermal expansion and excellent electrode stability. LaBaFe_1.9Mo_0.1O_5+δ is a promising cathode material for IT-SOFC, which shows an excellent electrochemical performance, with this being demonstrated by having the lowest polarization resistance value of 0.017 Ω·cm² at 800 °C, and the peak power density (PPD) of anode-supported single-cell LBFM_0.1|CGO|NiO+CGO reaching 599 mW·cm⁻². Full article

Plant-based carrier oils are constantly gaining popularity for their beneficial health effects on human organisms, thus shifting consumers’ preferences to alternative options in the oil market. The purpose of the study was to evaluate the quality characteristics of twenty-six edible plant-based fixed oils via chromatographic, chromatic, and spectroscopic techniques, suggesting their potential use as complementary edible oil sources. Palmitic, stearic, oleic, linoleic, and a-linolenic acids were found in considerable proportions, whereas the majority of oils possessed unsaturated (UFA)/saturated (SFA) fatty acid ratio greater than 1.6, suggesting their function in lowering blood pressure and preventing cardiovascular disease. Linseed, chia seed, macadamia, and canola oils provide a balanced intake of n-6 and n-3 polyunsaturated fatty acids (PUFA) within the range of 1:1 to 5:1. Oxidative stability was inversely related to oils’ PUFA content, with linseed, chia seed, pine cone, and walnut oils being the least stable oils against oxidation. Chlorophyll content in all oils was below the limit (50 mg/kg), preventing oxidation in the presence of light, whereas the highest values of b-carotene were noticed in soybean, linseed, and canola oils (61.18, 60.42, and 60.12 ppm, respectively). The application of machine learning algorithms for analyzing ATR-FTIR band intensities and FA proportions via discriminant analysis succeeded in discriminating pulp from seed oils, with a classification accuracy of 96.0% and 88.0%, respectively. Full article

Hawthorn (Crataegus monogyna) berry is a horticultural product containing antioxidants and pigments. Its extract can be used as a food dye and antioxidant in food engineering. The aim of present study is to research the effects of different possible conditions (temperature, pH, interacting ions, and storage conditions) on the color and antioxidant capacity of hawthorn berry extract. Color was assessed by monitoring the CIELab parameters, while antioxidant capacity was measured using the reaction with ABTS and DPPH radicals. The total phenolic content in berry powder was 1146 mg GAE/100 g and the main polyphenols identified by HPLC were epicatechin, ferulic acid methyl ester, catechin, procyanidins B1 and B2, and various phenolic acids. The main carotenoids, also quantified by HPLC, were mutatoxanthin, lutein, α-cryptoxanthin, β-cryptoxanthin, cis-β-carotene, all-trans-β-carotene, and lycopene. The values of the overall color difference suggest that storage affected the color of the hawthorn extract more than any of the thermal treatments. Alkaline pH values affected color by changing the blue/yellow component, but also luminosity and the green/red parameter. The antioxidant capacity decreased in acidic and neutral media and increased in mildly alkaline media at pH 8.1. The possible presence of interacting salts as potassium nitrate and sodium chloride did not produce any significant changes in antioxidant capacity, while calcium chloride lowered it, but only at 0.001 M. The interaction with the studied salts had little effect on the extract’s color. The obtained results demonstrated that hawthorn berry extracts can be used in the food industry as natural dyes, as it was proven to have very good antioxidant capacity and color stability after different thermal, pH, interacting salt, or storing conditions. Full article

A novel Ni-Cr-Si-B filler metal (JNi-5) was designed and further fabricated into the amorphous brazing filler metal for joining the GH4169 alloy. The effect of brazing temperature on the microstructure and mechanical properties of GH4169 joints was investigated. The typical microstructure of the joint at 1030 °C is composed of four specific zones: the base metal (BM), heat-affected zone (HAZ), isothermal solidification zone (ISZ), and athermal solidification zone (ASZ). The typical microstructure of the joint is GH4169/(Nb, Mo)-rich boride+(Cr, Nb, Mo)-rich boride/γ(Ni)/Ni-rich boride+γ(Ni)/γ(Ni)/(Cr, Nb, Mo)-rich boride+(Nb, Mo)-rich boride/GH4169. As the temperature increased, the HAZ continued to widen and the ASZ depleted at 1090 °C and 1120 °C. Additionally, the borides within the HAZ coarsened at temperatures of 1090 °C and 1120 °C. At 1030 °C, the fracture path is in the ASZ, and the existence of the brittle phase in the ASZ provides the potential origin for crack growth. The fracture mode is a quasi-cleavage fracture. At 1060 °C, 1090 °C, and 1120 °C, the fracture behavior mainly happened in the HAZ, and the existence of borides in the HAZ provides the potential origin for crack growth. Namely, the shear strength of joints was principally dominated by the brittle precipitations in the HAZ. The fracture mode of these joints is the hybrid ductile. At 1060 °C, the shear strength of the obtained joint is the highest value (693.78 MPa) due to the volume fraction increase in the Ni-based solid solution. Finally, the optimized brazing parameter of 1060 °C/10 min was determined, and the corresponding highest shear strength of 693.78 MPa was obtained owing to the increased content of the Ni-based solid solution in the joint. Full article

Fraxinus griffithii C. B. Clarke is introduced from Taiwan to Thailand by the Royal Project Foundation beginning of the 1980s for highland rehabilitation. To improve the growth traits and tree form characteristics, a tree breeding program for this species has been initiated. In the present study, we evaluated the among seed sources variations in growth traits (diameter at 1.3 m above the ground [DBH] and tree height) and wood traits (basic density [BD], modulus of elasticity [MOE], modulus of rupture [MOR], and compressive strength parallel to the grain [CS]) of 10-year-old F. griffithii trees originated from 15 seed sources planted in highland areas of Thailand. The mean values of measured trees were 7.25 cm in DBH, 11.59 m in tree height, 0.76 g/cm³ in basic density, 9.74 GPa in MOE, 100.78 MPa in MOR, and 38.46 MPa in CS, respectively. Broad-sense heritability ranged from 0.13 to 0.16 in growth traits and 0.02 to 0.85 in wood traits. As a result of principle component analysis and cluster analysis, 15 seed sources were classified into three groups. Of the three groups, one showed good performance in both growth and wood traits. Significant phenotypic and genetic correlations were found between growth traits and between wood traits. However, no significant correlations were found between growth and wood traits. Based on the results, it is concluded that progeny with good performance of both growth and wood traits can be produced from the combinations of superior seed sources tested in the present study. Full article

Background: Bradykinin is an endogenously produced nonapeptide with many physiological and pathological functions that are mediated by two pharmacologically defined receptor subtypes, B1- and B2-receptors. Current studies sought to characterize the functional bradykinin (BK) receptors present in freshly isolated bovine ciliary muscle (BCM) using an organ-bath tissue contraction system. Methods: Cumulative longitudinal isometric tension responses of BCM strips (4–5 mm) were recorded before and after the addition of test compounds to BCM strips hooked up to an isometric strain gauge transducer system. Results: BK and its analogs (7–11 concentrations) contracted BCM in a biphasic concentration-dependent manner. The first high affinity/potency phase accounted for 40–60% of the maximal contraction by each of BK (potency, EC₅₀ = 0.9 ± 0.3 nM), Lys-BK (EC₅₀ = 0.7 ± 0.1 nM), Met-Lys-BK (EC₅₀ = 1 ± 0.1 nM), Hyp3-BK (EC₅₀ = 1 ± 0.2 nM), RMP-7 (EC₅₀ = 3.5 ± 0.5 nM), and Des-Arg⁹-BK (EC₅₀ = 10 ± 0.4nM) (mean ± SEM, n = 3–8). The second lower activity phase of contraction potency values for these peptides ranged between 100 nM and 3 µM. In the presence of a selective B1-receptor antagonist (R715; 0.1–10 µM), the concentration–response curves to Des-Arg9-BK (B1-receptor agonist) were still observed, indicating activation of B2-receptors by this kinin. Likewise, when B2-receptors were completely blocked by using a B2-selective antagonist (WIN-64338; 1–10 µM), BK still induced BCM contraction, now by stimulating B1-receptors. Conclusions: This agonist/antagonist profile of BCM receptors indicated the presence of both B1- and B2-receptor subtypes, both being responsible for contracting this smooth muscle. The BCM kinin receptors may be involved in changing the shape of the ocular lens to influence accommodation, and since the ciliary muscle is attached to the trabecular meshwork through which aqueous humor drains, endogenously released kinins may regulate intraocular pressure. Full article

Localization of unmanned aircraft systems (UASs) in indoor scenarios and GNSS-denied environments is a difficult problem, particularly in dynamic scenarios where traditional on-board equipment (such as LiDAR, radar, sonar, camera) may fail. In the framework of autonomous UAS missions, precise feedback on real-time aircraft position is very important, and several technologies alternative to GNSS-based approaches for UAS positioning in indoor navigation have been recently explored. In this paper, we propose a low-cost IPS for UAVs, based on Bluetooth low energy (BLE) beacons, which exploits the RSSI (received signal strength indicator) for distance estimation and positioning. Distance information from measured RSSI values can be degraded by multipath, reflection, and fading that cause unpredictable variability of the RSSI and may lead to poor-quality measurements. To enhance the accuracy of the position estimation, this work applies a differential distance correction (DDC) technique, similar to differential GNSS (DGNSS) and real-time kinematic (RTK) positioning. The method uses differential information from a reference station positioned at known coordinates to correct the position of the rover station. A mathematical model was established to analyze the relation between the RSSI and the distance from Bluetooth devices (Eddystone BLE beacons) placed in the indoor operation field. The master reference station was a Raspberry Pi 4 model B, and the rover (unknown target) was an Arduino Nano 33 BLE microcontroller, which was mounted on-board a UAV. Position estimation was achieved by trilateration, and the extended Kalman filter (EKF) was applied, considering the nonlinear propriety of beacon signals to correct data from noise, drift, and bias errors. Experimental results and system performance analysis show the feasibility of this methodology, as well as the reduction of position uncertainty obtained by the DCC technique. Full article

Sesquiterpene pyridine alkaloids (SPAs), as a main class of components in Tripterygium wilfordii Hook. f., possess a variety of bioactivities, such as immunosuppressive, insecticidal, and anti-tumor activities. SPAs can be structurally classed into four subtypes: wilfordate-, evoninate-, iso-wilfordate-, and iso-evoninate types. Our previous study unveiled ten new wilfordate-type SPAs, named wilfordatine A–J, isolated from the roots of Tripterygium wilfordii Hook. f., several of which exhibited significant immunosuppressive activities. As an extension and augmentation of the previous findings, we have now isolated one new iso-wilfordate-type SPA, wilfordatine K (1), alongside three new iso-evoninate-type SPAs, wilfordatines L–N (3–5), and six known analogs. Their structures were characterized by the extensive use of 1D and 2D NMR spectroscopic analysis, as well as HRMS data. Interestingly, compounds 4 and 6 were found to exhibit potent inhibitory effects on the nuclear factor-kappa B (NF-κB) pathway in lipopolysaccharide (LPS)-induced HEK293/NF-κB-Luc cells, with IC₅₀ values of 1.64 μM and 9.05 μM, respectively. Notably, these two compounds had no influence on the cell viability at a concentration of 100 μM. Consequently, they hold significant promise as potential anti-inflammatory candidates for further exploration and development. Full article

This study examines the electromagnetic properties of a composite material composed of iron pyrite (FeS₂) and epoxy resin, mixed in a 3:2 weight ratio to create a 10 cm³ cube. The research analyzes transmission and reflection coefficients and band gap parameters to determine its viability as an antenna substrate for electromagnetic wave applications. The composite displays a tunable band gap of 1.3 eV, enabling selective absorption and emission of electromagnetic radiation. The transmission coefficient achieved 90% throughout a frequency range of 1 GHz to 15 GHz, whilst the reflection coefficient was measured at 10%, significantly reducing reflecting losses. The epoxy resin binder was essential for preserving structural integrity and augmenting the dielectric characteristics of the composite, thereby raising transmission efficiency. UV-Vis spectroscopy showed an absorption value of 0.875% at the band gap, indicating efficient interaction with UV energy. The S21 transmission coefficient ranged from −10 dB to −80 dB, with a maximum of −40 dB at 6 GHz, indicating strong energy transfer capability for antenna applications. The S21 values exhibited negligible signal attenuation between 2 GHz and 7 GHz, indicating the material’s exceptional suitability for antenna substrates necessitating dependable transmission. The S11 reflection coefficient varied from −5 dB to −55 dB, with substantial decreases between 4 GHz and 14 GHz, when reflection decreased to −45 dB, signifying little signal reflection at essential frequencies. The results underscore the composite’s appropriateness for applications requiring high transmission efficiency, little reflection, and effective engagement with electromagnetic waves, especially as an antenna substrate. Measurements were performed using a vector network analyzer (VNA) to obtain the S11 and S21 characteristics, underscoring the material’s potential in sophisticated electromagnetic applications. Full article