bluuebunny/crossref_metadata_2025 huggingface dataset:
A Lived Experience Well-Understood: What Montesquieu’s The Spirit of the Laws Can Tell Us about Civic Learning in Higher Education
Authors: Vassiliou Constantine Christos
Published: June 2024

This article considers how Montesquieu’s theoretical response to his perceived dangers of modern commerce may guide us on teaching citizenship in higher learning today. I argue that a Montesquieu informed framework for civic learning, which primarily stresses a careful study of the nation’s existing constitutional and positive laws, would (1) entail a baseline level of scientific and economic literacy to deepen our understanding of how commercial modernity’s most recent innovations may undermine the authority of those laws if left unchecked, and (2) cultivate an appreciation for the laws, mores, institutions, and practices that some of these same innovations threaten to dissolve if left unchecked. The article concludes with practical recommendations on how to cultivate resilient future custodians of our self-governing republic. I contend that universities need to provide a learning environment that inspires students to crave different kinds of success or recognition, distinctly highlighting the need for heavy restrictions on the use of electronics in the classroom. I then propose that civics-focused curricula must ensure that students are furnished with the requisite technocratic expertise to (1) recognize how their daily economic decisions as private citizens will impact the public interest and (2) exercise prudent judgment over future legislation aiming to safeguard individual liberties within a techno-mediated twenty-first century commercial world.
Improvement of Electro-Caloric Effect and Energy Storage Density in BaTiO3-Bi(Zn, Ti)O3 Ceramics Prepared with BaTiO3 Nano-Powder
Authors: Lee Geun-Soo , Kim Jeong-Seog , Cheon Chae-Il
Published: June 2024

BaTiO3-Bi(Zn,Ti)O3 (BT-BZT) ceramics have been used as capacitors due to their large dielectric permittivity and excellent temperature stability and are good candidates for lead-free materials for electrocaloric and energy storage devices. However, BT-BZT ceramics often suffer from inferior properties and poor reproducibility due to heterogeneous compositional distribution after calcination and sintering. In this work, (1−x)BT-xBZT ceramics (x = 0~0.2) were fabricated with nano-sized BaTiO3 raw materials (nano-BT) by a solid-state reaction method to enhance the chemical homogeneity. The (1−x)BT-xBZT ceramics prepared from the nano-BT showed larger densities and more uniform microstructures at the lower calcination and sintering temperatures than the samples prepared from more frequently used micrometer-sized raw materials BaCO3, TiO2, Bi2O3, and ZnO. The (1−x)BT-xBZT ceramic prepared from the nano-BT displayed a phase transition from a tetragonal ferroelectric to a pseudo-cubic relaxor in a narrower composition range than the sample prepared from micro-sized raw materials. Larger adiabatic temperature changes due to the electro-caloric effect (ΔTECE) and recoverable energy storage density (Urec) were observed in the samples prepared from the nano-BT due to the higher breakdown electric fields, the larger densities, and uniform microstructures. The 0.95BT-0.05BZT sample showed the largest ΔTECE of 1.59 K at 80 °C under an electric field of 16 kV/mm. The 0.82BT-0.18BZT sample displayed a Urec of 1.45 J/cm2, which is much larger than the previously reported value of 0.81 J/cm2 in BT-BZT ceramics. The nano-BT starting material produced homogeneous BT-BZT ceramics with enhanced ECE and energy storage properties and is expected to manufacture other homogeneous solid solutions of BaTiO3 and Bi-based perovskite with high performance.
Influence of Immersion Time on the Frequency Domain Characteristics of Acoustic Emission Signals in Clayey Mineral Rocks
Authors: Yan Jiaju , Li Zhuxi , Xia Dong , Bai Yuxin , Shao Guoliang
Published: June 2024

The frequency domain characteristics of acoustic emission can reflect issues such as rock structure and stress conditions that are difficult to analyze in time domain parameters. Studying the influence of immersion time on the mechanical properties and acoustic emission frequency domain characteristics of muddy mineral rocks is of great significance for comprehensively analyzing rock changes under water–rock coupling conditions. In this study, uniaxial compression tests and acoustic emission tests were conducted on sandstones containing montmorillonite under dry, saturated, and different immersion time conditions, with a focus on analyzing the effect of immersion time on the dominant frequency of rock acoustic emission. The results indicated that immersion time had varying degrees of influence on compressive strength, the distribution characteristics of dominant acoustic emission frequencies, the frequency range of dominant frequencies, and precursor information of instability failure for sandstones. After initial saturation, the strength of the rock sample decreased from 53.52 MPa in the dry state to 49.51 MPa, and it stabilized after 30 days of immersion. Both dry and initially saturated rock samples exhibited three dominant frequency bands. After different immersion days, a dominant frequency band appeared between 95 kHz and 110 kHz. After 5 days of immersion, the dominant frequency band near 0 kHz gradually disappeared. After 60 days of immersion, the dominant frequency band between 35 kHz and 40 kHz gradually disappeared, and with increasing immersion time, the dominant frequency of the acoustic emission signals increased. During the loading process of dry rock samples, the dominant frequency of acoustic emission signals was mainly concentrated between 0 kHz and 310 kHz, while after saturation, the dominant frequencies were all below 180 kHz. The most significant feature before the rupture of dry rock samples was the frequent occurrence of high frequencies and sudden changes in dominant frequencies. Before rupture, the characteristics of precursor events for initially saturated and immersed samples for 5, 10, and 30 days were the appearance and rapid increase in sudden changes in dominant frequencies, as well as an enlargement of the frequency range of dominant frequencies. After 60 days of immersion, the precursor characteristics of rock sample rupture gradually disappeared, and sudden changes in dominant frequencies frequently occurred at various stages of sample loading, making it difficult to accurately predict the rupture of specimens based on these sudden changes.
Accuracy of Mandibular Removable Partial Denture Frameworks Fabricated by 3D Printing and Conventional Techniques
Authors: Kim Soonam , Oh Kyung Chul , Kim Jee-Hwan
Published: June 2024

Herein, we used digital superimposition to evaluate the accuracy of metal frameworks for mandibular removable partial dentures fabricated using three techniques. Thirty master casts of a mandibular dentiform were categorized into three groups (n = 10) based on the framework manufacturing method: selective laser melting-based metal three-dimensional (3D) printing (SLM), digital light projection-based resin 3D printing and subsequent casting (RPC), and conventional casting (CON). The master casts were scanned twice, initially after preparation and subsequently after attaching silicone using the frameworks. These scan files were digitally superimposed to measure the silicone thickness. Statistical analysis was conducted using SPSS Statistics (Version 23.0, IBM Corp., Somers, NY, USA). One-way ANOVA and a post hoc Tukey’s multiple comparison tests were performed to determine differences among the three groups (α = 0.05). The RPC group exhibited significantly higher overall and mean internal discrepancies at rest and tissue stops than the SLM and CON groups, which exhibited statistically insignificant differences. Thus, SLM fabrication resulted in comparable accuracy to that achieved by CON, whereas sequentially performing resin 3D printing and casting induced inferior accuracy. However, all frameworks across the three groups were clinically acceptable.
Photodynamic and Antibacterial Assessment of Gold Nanoparticles Mediated by Gold (III) Chloride Trihydrate and Sodium Citrate under Alkaline Conditions
Authors: Cheng Chien-Wei , Lee Shwu-Yuan , Chen Tang-Yu , Chen Ching-Chuan , Tsai Hsien-Tsung , Huang Hsuan-Han , Yuann Jeu-Ming P. , Liang Ji-Yuan
Published: June 2024

Sodium citrate (SC) is sensitive to violet light illumination (VLI) and acts as a weak reductant. Conversely, gold (III) chloride trihydrate (GC) often acts as an oxidant in a redox reaction. In this study, the influences of colored light on the production of gold nanoparticles (AuNPs) in a mixture of gold (III) ions and citrate via VLI and the antibacterial photodynamic inactivation (aPDI) of Escherichia coli (E. coli) are determined under alkaline conditions. The diameter of AuNPs is within the range of 3–15 nm, i.e., their mean diameter is 9 nm; when citrate is mixed with gold (III) ions under VLI, AuNPs are formed via an electron transfer process. Additionally, GC mixed with SC (GCSC) inhibits E. coli more effectively under VLI than it does under blue, green, or red light. GCSC and SC are shown to inhibit E. coli populations by 4.67 and 1.12 logs, respectively, via VLI at 10 W/m2 for 60 min under alkaline conditions. GCSC-treated E. coli has a more significant photolytic effect on anionic superoxide radical (O2•−) formation under VLI, as more O2•− is formed within E. coli if the GCSC-treated samples are subjected to VLI. The O2•− exhibits a greater effect in a solution of GCSC than that shown by SC alone under VLI treatment. Gold (III) ions in a GCSC system appear to act as an oxidant by facilitating the electron transfer from citrate under VLI and the formation of AuNPs and O2•− via GCSC photolysis under alkaline conditions. As such, the photolysis of GCSC under VLI is a useful process that can be applied to aPDI.
The Multifaceted Comparison of Effects of Immobilisation of Waste Imperial Smelting Furnace (ISF) Slag in Calcium Sulfoaluminates (CSA) and a Geopolymer Binder
Authors: Łaźniewska-Piekarczyk Beata , Czop Monika , Rubin Jan Antoni
Published: June 2024

Using waste materials as replacements for sand in building materials helps reduce waste and improve the properties and sustainability of the construction materials. Authors proved the possibility of using imperial smelting furnace (ISF) slag granules as a 100% substitute for natural sand in self-compacting (SCC) cement-based mortars of calcium sulfoaluminates (CSA). The study proved that ISF slag’s radioactive properties meet this area’s requirements. CSA cement eliminates the noted problem in the case of concrete with Portland cement, which is the extended setting of the cement binder. The research findings indicate that using slag to replace sand up to 100% in mortars without grains smaller than 0.125 mm allows high flowability, compaction, low porosity and mechanical parameters. The compressive strength of the CSA cement mortars was about 110 MPa, and more than 140 MPa for geopolymer mortar. Unfortunately, the alkaline pH of a geopolymer causes high leachability of barium and sodium. Thus, the CSA cement is in a more favourable binder to achieve high strength, is environmentally friendly, and is a self-compacting mortar or concrete.
Effect of Discharge Energy on Micro-Arc Oxidation Coating of Zirconium Alloy
Authors: Wang Wei , Lv Kai , Du Zhaoxin , Chen Weidong , Pang Zhi
Published: June 2024

The micro-arc oxidation (MAO) technique was used to grow in situ oxidation coating on the surface of R60705 zirconium alloy in Na2SiO3, Na2EDTA, and NaOH electrolytes. The thickness, surface morphology, cross-section morphology, wear resistance, composition, and structure of the micro-arc oxidation coating were analyzed by an eddy current thickness measuring instrument, XPS, XRD, scanning electron microscopy, energy spectrometer, and wear testing machine. The corrosion resistance of the coating was characterized by a polarization curve and electrochemical impedance spectroscopy (EIS). The results show that, with the increase in frequency, the single-pulse discharge energy decreases continuously, and the coating thickness shows a decreasing trend, from the highest value of 152 μm at 400 Hz to the lowest value of 87.5 μm at 1000 Hz. The discharge pore size on the surface of the coating gradually decreases, and the wear resistance and corrosion resistance of the coating first increase and then decrease. The corrosion resistance is the best when the frequency is 400 Hz. At this time, the corrosion potential is −0.215 V, and the corrosion current density is 2.546 × 10−8 A·cm−2. The micro-arc oxidation coating of zirconium alloy is mainly composed of monoclinic zirconia (m-ZrO2) and tetragonal zirconia (t-ZrO2), in which the content of monoclinic zirconia is significantly more than that of tetragonal zirconia.
Preparation and Properties of Lightweight Geopolymer by Bio-Based Foaming Agent
Authors: Wang Tianlei , Chen Yao , Jing Xiudang , Wang Xueping , Zhang Lei , Yang Peisen
Published: June 2024

Lightweight geopolymers have the advantages of a wide source of raw materials, chemical corrosion resistance, high mechanical strength and excellent durability, and are expected to replace traditional building insulation materials. In this paper, a green bio-based foaming agent with a small 1 h settlement distance, high average foaming multiple and low bleeding ratio was obtained by a Cetyltrimethylammonium Bromide/yeast solution. When the amount of Cetyltrimethylammonium Bromide is 0.50 wt%, the foam prepared by the yeast and Cetyltrimethylammonium Bromide solution exhibits the improved 1 h settlement distance, the large average foaming multiple, the small bleeding ratio and uniform foam size. Subsequently, a lightweight geopolymer based on metakaolin and fly ash (or silica fume) was successfully prepared by the bio-based foaming agent, and the effects of different foam content on the properties of the geopolymer, such as dry density, water absorption, thermal conductivity, compressive strength and morphology, were studied. With an increase in foam content, the dry density, thermal conductivity and compressive strength of the geopolymer gradually decrease, the water absorption increases, regardless of whether silica fume or fly ash are added. Herein, it is confirmed that the foaming agent based on yeast can be effectively used to prepare lightweight geopolymers, which can provide vast opportunities to turn into candidates for novel inorganic thermal insulation materials.
Induction of Convolutional Decision Trees with Success-History-Based Adaptive Differential Evolution for Semantic Segmentation
Authors: López-Lobato Adriana-Laura , Acosta-Mesa Héctor-Gabriel , Mezura-Montes Efrén
Published: June 2024

Semantic segmentation is an essential process in computer vision that allows users to differentiate objects of interest from the background of an image by assigning labels to the image pixels. While Convolutional Neural Networks have been widely used to solve the image segmentation problem, simpler approaches have recently been explored, especially in fields where explainability is essential, such as medicine. A Convolutional Decision Tree (CDT) is a machine learning model for image segmentation. Its graphical structure and simplicity make it easy to interpret, as it clearly shows how pixels in an image are classified in an image segmentation task. This paper proposes new approaches for inducing a CDT to solve the image segmentation problem using SHADE. This adaptive differential evolution algorithm uses a historical memory of successful parameters to guide the optimization process. Experiments were performed using the Weizmann Horse dataset and Blood detection in dark-field microscopy images to compare the proposals in this article with previous results obtained through the traditional differential evolution process.
Evaluation of Selected Biometric Parameters in Cataract Patients—A Comparison between Argos® and IOLMaster 700®: Two Swept-Source Optical Coherence Tomography-Based Biometers
Authors: Porwolik Mateusz , Porwolik Agnieszka , Mrukwa-Kominek Ewa
Published: June 2024

Background and Objectives: To compare the biometry of eyes obtained with two swept-source optical coherence tomography-based biometers—Argos (A), using an individual refractive index, and IOLMaster 700 (IM), using an equivalent refractive index—for all structures. Materials and Methods: The biometry of 105 eyes of 105 patients before cataracts were analyzed in this study. Parameters such as axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) were compared from both devices. According to the axial length measurements, patients were divided into three groups, as follows: group 1—short eyes (AL < 22.5 mm), group 2—average eyes (22.5 ≤ AL ≤ 26.0 mm), and group 3—long eyes (AL > 26.0 mm). Results: The correlation coefficiency among all compared parameters varies from R = 0.92 to R = 1.00, indicating excellent reliability of IM and A. A statistical significance in axial length was indicated in the group of short eyes (n = 26)—mean AL (A) 21.90 mm (±0.59 mm) vs. AL (IM) 21.8 mm ± (0.61 mm) (p < 0.001)—and in the group of long eyes (n = 5)—mean AL (A) 27.95 mm (±2.62 mm) vs. mean AL (IM) 28.10 mm (±2.64) (p < 0.05). In the group of average eyes (n = 74), outcomes were similar—mean AL (A) 23.56 mm (±0.70 mm) vs. mean AL (IM) 23,56 mm (±0.71 mm) (p > 0.05). The anterior chamber depth measurements were higher when obtained with Argos than with IOLMaster 700—mean ACD (A) 3.06 mm (±0.48 mm) vs. mean ACD (IM) 2.92 mm (±0.46) p < 0.001. There was no statistical significance in mean LT—mean LT (A) 4.75 mm (±0.46 mm) vs. mean LT (IM) 4.72 mm (±0.44 mm) (p = 0.054). The biometry of one eye with dense cataracts could be measured only with Argos, using the Enhanced Retinal Visualization mode. Conclusions: Axial length measurements from both devices were different in the groups of short and long eyes, but were comparable in the group of average eyes. The anterior chamber depth values obtained with Argos were higher than the measurements acquired with IOLMaster 700. These differences may be particularly important when selecting IOLs for patients with extreme AL values.
Temperature-Dependent Mechanical Behaviors and Deformation Mechanisms in a Si-Added Medium-Entropy Superalloy with L12 Precipitation
Authors: Zhang Tuanwei , Bai Tianxiang , Xiong Renlong , Luo Shunhui , Chang Hui , Du Shiyu , Ma Jinyao , Jiao Zhiming , Ma Shengguo , Wang Jianjun , Wang Zhihua
Published: June 2024

A novel Ni-Co-Cr-based medium-entropy superalloy with a high Si content (7.5 at%) strengthened by an L12 phase was developed. The pure L12 phase, characterized by an average size of 50 nm and a volume fraction of 46%, was precipitated within the FCC matrix. This alloy exhibits excellent mechanical properties over a wide range of temperatures from 77 K to 1073 K. A yield strength of 1005 MPa, an ultimate tensile strength of 1620 MPa, and a tensile elongation of 36% were achieved at 77 K, with a maximum value of 4.8 GPa at the second stage of the work-hardening rate. The alloy maintains a basically consistent yield strength of approximately 800 MPa from 298 K to 973 K, showcasing significant strain-hardening capabilities, with values of 2.5 GPa, 3.7 GPa, and 4.8 GPa at 873 K, 298 K, and 77 K, respectively. Microscopic analysis revealed that at room and cryogenic temperatures, multilayer stacking faults (SFs), SF bands, and SF networks, rather than twins, effectively stored a large number of dislocations and impeded dislocation movement, thereby enhancing the work-hardening ability of the alloy. Furthermore, at 773 K, the primary deformation mechanism involved high-density dislocation walls (HDDWs) consisting of dislocation tangles and SF lines. As the temperature rose to 973 K, the work-hardening process was influenced by the APB shearing mechanism (in the form of dislocation pairs), SF lines, and microtwins generated through atomic rearrangement. This study not only provides valuable insights for the development of new oxidation-resistant superalloys but also enhances our understanding of high-temperature deformation mechanisms.
Effect of Tool Speed on Microstructure Evolution and Mechanical Properties of Friction Stir Welded Joints of Al-Mg-Si Alloy with High Cu Content
Authors: Li Wangzhen , Luo Zhang , Sun Youping , Liu Xinyu
Published: June 2024

OM, SEM, EBSD, and other analytical techniques were utilized to investigate the effects of the rotating speed of a mixing head on the microstructures and mechanical properties of a joint. The results indicate that, compared with the base material, the grain size in the nugget zone is significantly refined. Furthermore, as the rotational speed of the mixing head increases, the grain size in the nugget zone increases noticeably, and the proportion of high-angle grain boundary length initially decreases and then increases. The texture types in different areas of the joint are markedly distinct: the base material primarily consists of recrystallization texture and rolling texture, while the core zone mainly comprises C-shear texture. Among the joints tested at various rotation speeds, the lowest hardness values are observed in the advancing side heat-affected zone, and the tensile properties of the joints are notably reduced due to the dissolution and coarsening of the second phase. The joint exhibits optimal performance at 1000 r/min, with a tensile strength and elongation of 196.3 MPa and 13.5%, respectively.
Association of DNA Methylation with Infant Birth Weight in Women with Gestational Diabetes
Authors: Saucedo Renata , Ferreira-Hermosillo Aldo , Robledo-Clemente Magalhi , Díaz-Velázquez Mary Flor , Valencia-Ortega Jorge
Published: June 2024

Offspring exposed to gestational diabetes mellitus (GDM) exhibit greater adiposity at birth. This early-life phenotype may increase offspring risk of developing obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease later in life. Infants born to women with GDM have a dysregulation of several hormones, cytokines, and growth factors related to fetal fat mass growth. One of the molecular mechanisms of GDM influencing these factors is epigenetic alterations, such as DNA methylation (DNAm). This review will examine the role of DNAm as a potential biomarker for monitoring fetal growth during pregnancy in women with GDM. This information is relevant since it may provide useful new biomarkers for the diagnosis, prognosis, and treatment of fetal growth and its later-life health consequences.
Physicochemical Characterization of Moroccan Honey Varieties from the Fez-Meknes Region and Their Antioxidant and Antibacterial Properties
Authors: Ailli Atika , Zibouh Khalid , Eddamsyry Brahim , Drioiche Aziz , Fetjah Dounia , Ayyad Fatima Zahra , Mothana Ramzi A. , Hawwal Mohammed F. , Radi Mohamed , Tarik Redouane , Elomri Abdelhakim , Mouradi Aicha , Zair Touriya
Published: June 2024

Honey, with its varied and extensive characteristics, is a complex and diverse biological substance that has been used since ancient times. The aim of this study is to thoroughly characterize the physicochemical, phytochemical, and biological properties of four floral honey varieties from the Fez-Meknes region in Morocco, with the goal of promoting the valorization of Moroccan honey in skincare and cosmetic products. The analyses of their physicochemical characteristics encompass various parameters such as pH, acidity, density, water content, Brix index, conductivity, ash content, hydroxymethylfurfural (HMF) content, and color. The levels of polyphenols range from 22.1 ± 0.4 to 69.3 ± 0.17 mg GAE/100 g of honey, measured using the Folin–Ciocalteu method for polyphenol quantification. Additionally, the estimation of flavonoid quantities in 100 g of honey, conducted using the aluminum trichloride method, reveals values ranging from 3.6 ± 0.2 to 7.2 ± 0.6 mg QE. Furthermore, it is noteworthy that honey exhibits high levels of glucose and relatively low concentrations of proteins. The quantitative evaluation of antioxidant effects, carried out through the 2,2-diphenyl-1-picrylhydrazyl free-radical-scavenging method and the ferric-reducing antioxidant power (FRAP) method, highlights the strong antioxidant capacity of multifloral honey, characterized by low inhibitory concentration values (IC50 = 30.43 mg/mL and EC50 = 16.06 mg/mL). Moreover, all honey varieties demonstrate antibacterial and antifungal properties, with multifloral honey standing out for its particularly pronounced antimicrobial activity. The correlation analyses between phytochemical composition and antioxidant and antibacterial activities reveal an inverse relationship between polyphenols and IC50 (DPPH) and EC50 (FRAP) concentrations of honey. The correlation coefficients are established at R2 = −0.97 and R2 = −0.99, respectively. Additionally, a significant negative correlation is observed between polyphenols, flavonoids, and antifungal power (R2 = −0.95 and R2 = −0.96). In parallel, a marked positive correlation is highlighted between antifungal efficacy, DPPH antioxidant activity (R2 = 0.95), and FRAP (R2 = 0.92). These results underscore the crucial importance of phytochemical components in the beneficial properties of honey, meeting international quality standards. Consequently, honey could serve as a natural alternative to synthetic additives.
Origin of the Kunduleng Granite and Its Associated Uranium Anomaly in the Southern Great Xing’an Range, NE China
Authors: Sun Jiaxing , Sun Deyou , Gou Jun , Yang Dongguang , Wang Changdong , Tian Li , Zhang Duo
Published: June 2024

The Kunduleng granite hosts one of several significant uranium anomalies within the southern Great Xing’an Range, NE China. Whole-rock geochemistry and mineral chemistry data, along with the zircon U-Pb-Hf isotope have been used to constrain the petrogenesis of this granitic intrusion and the origin of the uranium anomaly. Microscopically, quartz, alkali-feldspar, and plagioclase are the essential mineral constituents of the granite, with minor biotite, while monazite, apatite, xenotime, and zircon are accessory minerals. Geochemically, the silica- and alkali-rich granites show a highly fractionated character with “seagull-shaped” REE patterns and significant negative anomalies of Ba and Sr, along with low Zr/Hf and Nb/Ta ratios. The granite has positive zircon εHf(t) values ranging from +12.7 to +14.5 and crustal model ages (TDM2) of 259–376 Ma, indicating a Paleozoic juvenile crustal source. Uraninite and brannerite are the main radioactive minerals responsible for the uranium anomaly within the Kunduleng granite. Uraninite presents well-developed cubic crystals and occurs as tiny inclusions in quartz and K-feldspar with magmatic characteristics (e.g., elevated ThO2, Y2O3, and REE2O3 contents and low CaO, FeO, and SiO2 concentrations). The calculated U-Th-Pb chemical ages (135.4 Ma) are contemporaneous with the U-Pb zircon age (135.4–135.6 Ma) of the granite, indicating a magmatic genesis for uraninite. The granites are highly differentiated, and extreme magmatic fractionation might be the main mechanism for the initial uranium enrichment. Brannerite is relatively less abundant and typically forms crusts on ilmenite and rutile or it cements them, representing the local redistribution and accumulation of uranium.
Isolation Techniques, Structural Characteristics, and Pharmacological Effects of Phellinus Polysaccharides: A Review
Authors: Yin Yiming , Shi Xiaolin , Cai Xiaoqing , Liu Fangrui , Ni Wenting , Li Baohong , Wan Xinhuan , Ren Meng
Published: June 2024

Phellinus is a precious perennial medicinal fungus. Its polysaccharides are important bioactive components, and their chemical composition is complex. The polysaccharides are mainly extracted from the fruiting body and mycelium. The yield of the polysaccharides is dependent on the extraction method. They have many pharmacological activities, such as antitumor, immunomodulatory, antioxidant, hypoglycemic, anti-inflammatory, etc. They are also reported to show minor toxic and side effects. Many studies have reported the anticancer activity of Phellinus polysaccharides. This review paper provides a comprehensive examination of the current methodologies for the extraction and purification of Phellinus polysaccharides. Additionally, it delves into the structural characteristics, pharmacological activities, and mechanisms of action of these polysaccharides. The primary aim of this review is to offer a valuable resource for researchers, facilitating further studies on Phellinus polysaccharides and their potential applications.
Optimizing the Extraction of the Polyphenolic Fraction from Defatted Strawberry Seeds for Tiliroside Isolation Using Accelerated Solvent Extraction Combined with a Box–Behnken Design
Authors: Wójciak Magdalena , Mazurek Barbara , Wójciak Weronika , Kostrzewa Dorota , Żuk Magdalena , Chmiel Mariusz , Kubrak Tomasz , Sowa Ireneusz
Published: June 2024

Tiliroside is a natural polyphenolic compound with a wide range of biological activity, and defatted strawberry seeds are its rich source. The goal of this study was to optimize accelerated solvent extraction (ASE) conditions, including temperature, solvent composition, and the number of extraction cycles, using Box–Behnken design to maximize the yield of tiliroside. UPLC-DAD-MS was applied to investigate the polyphenolic composition of the extracts, and preparative liquid chromatography (pLC) was used for isolation. All obtained mathematical models generally showed an increase in the efficiency of isolating polyphenolic compounds with an increase in temperature, ethanol content, and the number of extraction cycles. The optimal established ASE conditions for tiliroside were as follows: a temperature of 65 °C, 63% ethanol in water, and four extraction cycles. This allowed for the obtainment of a tiliroside-rich fraction, and the recovery of isolated tiliroside from plant material reached 243.2 mg from 100 g. Our study showed that ASE ensures the isolation of a tiliroside-rich fraction with high effectiveness. Furthermore, defatted strawberry seeds proved to be a convenient source of tiliroside because the matrix of accompanying components is relatively poor, which facilitates separation.
A Cost-Effective and Sensitive Method for the Determination of Lincomycin in Foods of Animal Origin Using High-Performance Liquid Chromatography
Authors: Ye Minqi , Hou Limin , Jiang Zongpei , Sun Xueyan , Chen Liangzhu , Fang Binghu
Published: June 2024

Background: Lincomycin (LIN) is extensively used for treating diseases in livestock and promoting growth in food animal farming, and it is frequently found in both the environment and in food products. Currently, most of the methods for detecting lincomycin either lack sensitivity and precision or require the use of costly equipment such as mass spectrometers. Result: In this study, we developed a reliable high-performance liquid chromatography-ultraviolet detection (HPLC-UVD) method and used it to detect LIN residue in 11 types of matrices (pig liver and muscle; chicken kidney and liver; cow fat, liver and milk; goat muscle, liver and milk; and eggs) for the first time. The tissue homogenates and liquid samples were extracted via liquid–liquid extraction, and subsequently purified and enriched via sorbent and solid phase extraction (SPE). After nitrogen drying, the products were derivatized with p-toluene sulfonyl isocyanic acid (PTSI) (100 µL) for 30 min at room temperature. Finally, the derivatized products were analyzed by HPLC at 227 nm. Under the optimized conditions, the method displayed impressive performance and demonstrated its reliability and practicability, with a limit of detection (LOD) and quantification (LOQ) of LIN in each matrix of 25–40 μg/kg and 40–60 μg/kg, respectively. The recovery ranged from 71.11% to 98.30%. Conclusions: The results showed that this method had great selectivity, high sensitivity, satisfactory recovery and cost-effectiveness—fulfilling the criteria in drug residue and actual detection requirements—and proved to have broad applicability in the field of detecting LIN in animal-derived foods.
Synergistic Effect of UiO-66 Directly Grown on Kombucha-Derived Bacterial Cellulose for Dye Removal
Authors: Plaza-Joly Pierre , Gallois Arthur , Bosc-Rouessac Florence , Drobek Martin , Julbe Anne
Published: June 2024

Metal–Organic Frameworks (MOFs) are particularly attractive sorbents with great potential for the removal of toxic dye pollutants from industrial wastewaters. The uniform dispersion of MOF particles on suitable substrates then represents a key condition to improve their processability and provide good accessibility to the active sites. In this work, we investigate the efficiency of a natural bacterial cellulose material derived from Kombucha (KBC) as an active functional support for growing and anchoring MOF particles with UiO-66 structures. An original hierarchical microstructure was obtained for the as-developed Kombucha cellulose/UiO-66 (KBC-UiO) composite material, with small MOF crystals (~100 nm) covering the cellulose fibers. Promising adsorption properties were demonstrated for anionic organic dyes such as fluorescein or bromophenol blue in water at pH 5 and pH 7 (more than 90% and 50% removal efficiency, respectively, after 10 min in static conditions). This performance was attributed to both the high accessibility and uniform dispersion of the MOF nanocrystals on the KBC fibers together with the synergistic effects involving the attractive adsorbing properties of UiO-66 and the surface chemistry of KBC. The results of this study provide a simple and generic approach for the design of bio-sourced adsorbents and filters for pollutants abatement and wastewater treatment.
Lattice-Strained Bimetallic Nanocatalysts: Fundamentals of Synthesis and Structure
Authors: Wang Yaowei , Shi Huibing , Zhao Deming , Zhang Dongpei , Yan Wenjuan , Jin Xin
Published: June 2024

Bimetallic nanostructured catalysts have shown great promise in the areas of energy, environment and magnetics. Tunable composition and electronic configurations due to lattice strain at bimetal interfaces have motivated researchers worldwide to explore them industrial applications. However, to date, the fundamentals of the synthesis of lattice-mismatched bimetallic nanocrystals are still largely uninvestigated for most supported catalyst materials. Therefore, in this work, we have conducted a detailed review of the synthesis and structural characterization of bimetallic nanocatalysts, particularly for renewable energies. In particular, the synthesis of Pt, Au and Pd bimetallic particles in a liquid phase has been critically discussed. The outcome of this review is to provide industrial insights of the rational design of cost-effective nanocatalysts for sustainable conversion technologies.
Measurement Uncertainty and Risk of False Compliance Assessment Applied to Carbon Isotopic Analyses in Natural Gas Exploratory Evaluation
Authors: Leal Fabiano , de Andrade Ferreira Alexandre , Silva Gabriel , Freire Tulio , Costa Marcelo , de Morais Erica , Guzzo Jarbas , de Oliveira Elcio
Published: June 2024

The concept of uncertainty in an isotopic analysis is not uniform in the scientific community worldwide and can compromise the risk of false compliance assessment applied to carbon isotopic analyses in natural gas exploratory evaluation. In this work, we demonstrated a way to calculate one of the main sources of this uncertainty, which is underestimated in most studies focusing on gas analysis: the δ13C calculation itself is primarily based on the raw analytical data. The carbon isotopic composition of methane, ethane, propane, and CO2 was measured. After a detailed mathematical treatment, the corresponding expanded uncertainties for each analyte were calculated. Next, for the systematic isotopic characterization of the two gas standards, we calculated the standard uncertainty, intermediary precision, combined standard uncertainty, and finally, the expanded uncertainty for methane, ethane, propane, and CO2. We have found an expanded uncertainty value of 1.8‰ for all compounds, except for propane, where a value of 1.6‰ was obtained. The expanded uncertainty values calculated with the approach shown in this study reveal that the error arising from the application of delta calculation algorithms cannot be neglected, and the obtained values are higher than 0.5‰, usually considered as the accepted uncertainty associated with the GC-IRMS analyses. Finally, based on the use of uncertainty information to evaluate the risk of false compliance, the lower and upper acceptance limits for the carbon isotopic analysis of methane in natural gas are calculated, considering the exploratory limits between −55‰ and −50‰: (i) for the underestimated current uncertainty of 0.5‰, the lower and upper acceptance limits, respectively, are −54.6‰ and −50.4‰; and (ii) for the proposed realistic uncertainty of 1.8‰, the lower and upper acceptance limits would be more restrictive; i.e., −53.5‰ and −51.5‰, respectively.
An Investigation of N-Hydroxyphthalimide Catalyzed Aerobic Oxidation of Toluene without Metal Ions in Liquid Phase: Effect of Solvents and Phase Transfer Catalysts
Authors: Shi Guojun , Dong Longsheng , Feng Ya
Published: June 2024

The selective oxidation of toluene to yield value-added oxygenates, such as benzyl alcohol, benzaldehyde, and benzoic acid, via dioxygen presents a chlorine-free approach under benign conditions. Metal-free catalytic processes are preferred to avoid metal ion contamination. In this study, we employed N-hydroxyphthalimide (NHPI) as a catalyst for the aerobic oxidation of toluene to its oxygenated derivatives. The choice of solvent exerted a significant impact on the catalytic activity and selectivity of the catalyst NHPI at reaction temperatures exceeding 70 °C. Notably, hexafluoroisopropanol substantially enhanced the selective production of benzaldehyde. Furthermore, we identified didecyl dimethyl ammonium bromide, featuring two symmetrical long hydrophobic chains, as a potent enhancer of NHPI for the solvent-free aerobic oxidation of toluene. This effect is ascribed to its unique symmetrical structure, extraction capabilities, and resistance to thermal and acid/base conditions. Based on the product distribution and control experiments, we proposed a plausible reaction mechanism. These findings may inform the industrial synthesis of oxygenated derivatives from toluene.
Bio-Sourced Flame Retardants for Textiles: Where We Are and Where We Are Going
Authors: Malucelli Giulio
Published: June 2024

After the period of halogenated compounds, the period of nano-structured systems, and that of phosphorus (and nitrogen)-based additives (still in progress), following the increasingly demanding circular economy concept, about ten years ago the textile flame retardant world started experiencing the design and exploitation of bio-sourced products. Indeed, since the demonstration of the potential of such bio(macro)molecules as whey proteins, milk proteins (i.e., caseins), and nucleic acids as effective flame retardants, both natural and synthetic fibers and fabrics can take advantage of the availability of several low-environmental impact/“green” compounds, often recovered from wastes or by-products, which contain all the elements that typically compose standard flame-retardant recipes. The so-treated textiles often exhibit flame-retardant features that are similar to those provided by conventional fireproof treatments. Further, the possibility of using the same deposition techniques already available in the textile industry makes these products very appealing, considering that the application methods usually do not require hazardous or toxic chemicals. This review aims to present an overview of the development of bio-sourced flame retardants, focusing attention on the latest research outcomes, and finally discussing some current challenging issues related to their efficient application, paving the way toward further future implementations.
Characterisation of Basic Sites on Ga2O3, MgO, and ZnO with Preadsorbed Ethanol and Ammonia—IR Study
Authors: Podobiński Jerzy , Datka Jerzy
Published: June 2024

The effect of adsorption of ethanol and ammonia on the basicity of Ga2O3, MgO, and ZnO was examined via IR studies of CO2 adsorption. Ethanol reacts with OH groups on Ga2O3, and MgO, forming ethoxyl groups. The substitution of surface hydroxyls by ethoxyls increases the basicity of the neighbouring oxygen. The ethoxyl groups that also form on ZnO do not contain surface OH groups, but the mechanism of their formation is different. On ZnO, ethoxy groups are formed by the reaction of ethanol with surface oxygens. The presence of ethoxyls on ZnO decreases the basicity because some surface oxygens are already engaged in the bonding of ethoxyl groups. The effect of ammonia adsorption on basicity is different for each oxide. For Ga2O3, ammonia adsorption increases the basicity of neighbouring oxygen sites. Ammonia is not adsorbed on MgO; therefore, it does not change the basicity of this oxide. Ammonia adsorbed on ZnO forms coordination bonds with Zn sites; it does not change the number of basic sites but changes how carbonate species are bonded to surface sites.
The Role of Intraligand Charge Transfer Processes in Iridium(III) Complexes with Morpholine-Decorated 4′-Phenyl-2,2′:6′,2″-terpyridine
Authors: Palion-Gazda Joanna , Kwiecień Aleksandra , Choroba Katarzyna , Penkala Mateusz , Kryczka Anna , Machura Barbara
Published: June 2024

To investigate the impact of the electron-donating morpholinyl (morph) group on the ground- and excited-state properties of two different types of Ir(III) complexes, [IrCl3(R-C6H4-terpy-κ3N)] and [Ir(R-C6H4-terpy-κ3N)2](PF6)3, the compounds [IrCl3(morph-C6H4-terpy-κ3N)] (1A), 4[Ir(morph-C6H4-terpy-κ3N)2](PF6)3 (2A), [IrCl3(Ph-terpy-κ3N)] (1B) and [Ir(Ph-terpy-κ3N)2](PF6)3 (2B) were obtained. Their photophysical properties were comprehensively investigated with the aid of static and time-resolved spectroscopic methods accompanied by theoretical DFT/TD-DFT calculations. In the case of bis-terpyridyl iridium(III) complexes, the attachment of the morpholinyl group induced dramatic changes in the absorption and emission characteristics, manifested by the appearance of a new, very strong visible absorption tailing up to 600 nm, and a significant bathochromic shift in the emission of 2A relative to the model chromophore. The emission features of 2A and 2B were found to originate from the triplet excited states of different natures: intraligand charge transfer (3ILCT) for 2A and intraligand with a small admixture of metal-to-ligand charge transfer (3IL–3MLCT) for 2B. The optical properties of the mono-terpyridyl iridium(III) complexes were less significantly impacted by the morpholinyl substituent. Based on UV–Vis absorption spectra, emission wavelengths and lifetimes in different environments, transient absorption studies, and theoretical calculations, it was demonstrated that the visible absorption and emission features of 1A are governed by singlet and triplet excited states of a mixed MLLCT-ILCT nature, with a dominant contribution of the first component, that is, metal-ligand-to-ligand charge transfer (MLLCT). The involvement of ILCT transitions was reflected by an enhancement of the molar extinction coefficients of the absorption bands of 1A in the range of 350–550 nm, and a small red shift in its emission relative to the model chromophore.
URJC-1: Stable and Efficient Catalyst for O-Arylation Cross-Coupling
Authors: García-Rojas Elena , Leo Pedro , Tapiador Jesús , Martos Carmen , Orcajo Gisela
Published: June 2024

The design of metal–organic frameworks (MOFs) allows the definition of properties for their final application in small-scale heterogeneous catalysis. Incorporating various catalytic centers within a single structure can produce a synergistic effect, which is particularly intriguing for cross-coupling reactions. The URJC-1 material exhibits catalytic duality: the metal centers act as Lewis acid centers, while the nitrogen atoms of the organic ligand must behave as basic centers. The impact of reaction temperature, catalyst concentration, and basic agent concentration was evaluated. Several copper-based catalysts, including homogeneous and heterogeneous MOF catalysts with and without the presence of nitrogen atoms in the organic ligand, were assessed for their catalytic effect under optimal conditions. Among the catalysts tested, URJC-1 exhibited the highest catalytic activity, achieving complete conversion of 4-nitrobenzaldehyde with only 3% mol copper concentration in one hour. Furthermore, URJC-1 maintained its crystalline structure even after five reaction cycles, demonstrating remarkable stability in the reaction medium. The study also examined the impact of various substituents of the substrate alcohol on the reaction using URJC-1. The results showed that the reaction had high activity when activating substituents were present and for most cyclic alcohols rather than linear ones.
Nanocurcumin-Based Sugar-Free Formulation: Development and Impact on Diabetes and Oxidative Stress Reduction
Authors: Ferradj Safa , Yahoum Madiha Melha , Rebiha Mounia , Nabi Ikram , Toumi Selma , Lefnaoui Sonia , Hadj-Ziane-Zafour Amel , Touzout Nabil , Tahraoui Hichem , Mihoub Adil , Seleiman Mahmoud F. , Ali Nawab , Zhang Jie , Amrane Abdeltif
Published: June 2024

The objective of this study is the development of innovative nanocurcumin-based formulations designed for the treatment and prevention of oxidative stress and diabetes. Nanocurcumin was obtained through a micronization process and subsequently encapsulated within biopolymers derived from corn starch and fenugreek mucilage, achieving encapsulation rates of 75% and 85%, respectively. Subsequently, the encapsulated nanocurcumin was utilized in the formulation of sugar-free syrups based on Stevia rebaudiana Bertoni. The stability of the resulting formulations was assessed by monitoring particle size distribution and zeta potential over a 25-day period. Dynamic light scattering (DLS) revealed a particle size of 119.9 nm for the fenugreek mucilage-based syrup (CURF) and 117 nm for the corn starch-based syrup (CURA), with polydispersity indices PDIs of 0.509 and 0.495, respectively. The dissolution rates of the encapsulated nanocurcumin were significantly enhanced, showing a 67% improvement in CURA and a 70% enhancement in CURF compared with crude curcumin (12.82%). Both formulations demonstrated excellent antioxidant activity, as evidenced by polyphenol quantification using the 2.2-diphenyl 1-pycrilhydrazyl (DPPH) assay. In the evaluation of antidiabetic activity conducted on Wistar rats, a substantial reduction in fasting blood sugar levels from 392 to 187 mg/mL was observed. The antioxidant properties of CURF in reducing oxidative stress were clearly demonstrated by a macroscopic observation of the rats’ livers, including their color and appearance.
Human Milk Protein-Derived Bioactive Peptides from In Vitro-Digested Colostrum Exert Antimicrobial Activities against Common Neonatal Pathogens
Authors: Lyu Yang , Kim Bum Jin , Patel Jagdish Suresh , Dallas David C. , Chen Yimin
Published: June 2024

Human milk reduces risk for necrotizing enterocolitis in preterm infants. Necrotizing enterocolitis occurs in the ileocecal region where thousands of milk protein-derived peptides have been released from digestion. Digestion-released peptides may exert bioactivity, such as antimicrobial and immunomodulatory activities, in the gut. In this study, we applied mass spectrometry-based peptidomics to characterize peptides present in colostrum before and after in vitro digestion. Sequence-based computational modeling was applied to predict peptides with antimicrobial activity. We identified more peptides in undigested samples, yet the abundances were much higher in the digested samples. Heatmapping demonstrated highly different peptide profiles between undigested and digested samples. Four peptides (αS1-casein [157–163], αS1-casein [157–165], β-casein [153–159] and plasminogen [591–597]) were selected, synthesized and tested against common pathogenic bacteria associated with necrotizing enterocolitis. All four exhibited bacteriostatic, though not bactericidal, activities against Klebsiella aerogenes, Citrobacter freundii and Serratia marcescens, but not Escherichia coli.