Search Results (710)

A nanoparticle formulation was generated from distiller dried grains with solubles (DDGS), and its effect on the production of anthraquinones (AQs) was evaluated on Rubia tinctorum hairy roots. The DDGS material was washed with water and ethyl acetate to remove mainly the soluble organic/inorganic molecules and reduce the fat content, respectively, followed by an alkaline treatment to remove the polysaccharides. The resulting alkaline solutions were then lyophilized and redispersed in deionized water to generate a monodispersed nanoparticulate formulation (DDGS-NP) with a hydrodynamic diameter and zeta potential of 227 ± 42 nm and −53 ± 7 mV, respectively. The formulation demonstrated good colloidal stability over time, and sterilized DDGS-NPs maintained comparable physicochemical properties. The nanoparticles were enriched in protein fractions, unsaturated fatty acids, and orthophosphate anion components from DDGS, as determined by solid-state Nuclear Magnetic Resonance (NMR), X-ray photoelectron spectroscopy (XPS), organic elemental analysis (OEA), and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. The DDGS-NPs were tested at different concentrations on Rubia tinctorum hairy roots, in comparison to or in combination with methyl jasmonate (MeJ), for their capacity to induce the production of AQs. All DDGS-NP concentrations increased the production of specific AQs to 7.7 (100 mg L⁻¹), 7.8 (200 mg L⁻¹), and 9.3 µmol/gFW (500 mg L⁻¹), with an extracellular AQ accumulation of 18 µM for the highest DDGS-NP concentration, in comparison with the control hairy roots (~2 µM AQ). The plant growth was not affected at any of the tested nanoparticle concentrations. Interestingly, the combination of DDGS-NPs and MeJ resulted in the highest extracellular AQ accumulation in R. tinctorum root cultures. Full article

After reviewing the state of the art of the fluorination of inorganic solid electrolytes, an application of gas/solid fluorination is given and how it can be processed. Garnet-type oxide has been chosen. These oxides with an ideal structure of chemical formula A₃B₂(XO₄)₃ are mainly known for their magnetic and dielectric properties. Certain garnets may have a high enough Li⁺ ionic conductivity to be used as solid electrolyte of lithium ion battery. The surface of LLZO may be changed in contact with the moisture and CO₂ present in the atmosphere that results in a change of the conductivity at the interface of the solid. LiOH and/or lithium carbonate are formed at the surface of the garnet particles. In order to allow for handling and storage under normal conditions of this solid electrolyte, surface fluorination was performed using elemental fluorine. When controlled using mild conditions (temperature lower or equal to 200 °C, either in static or dynamic mode), the addition of fluorine atoms to LLZO with Li_6,4Al_0,2La₃Zr₂O₁₂ composition is limited to the surface, forming a covering layer of lithium fluoride LiF. The effect of the fluorination was evidenced by IR, Raman, and NMR spectroscopies. If present in the pristine LLZO powder, then the carbonate groups disappear. More interestingly, contrary to the pristine LLZO, the contents of these groups are drastically reduced even after storage in air up to 45 days when the powder is covered with the LiF layer. Surface fluorination could be applied to other solid electrolytes that are air sensitive. Full article

A quantitative characterization of the change in coal molecular structures with different cyclical microwave modification parameters and a better understanding of the reaction mechanism of the modification are of great significance for the commercial extraction of coal bed methane (CBM). Therefore, long-flame coal samples obtained from the Ordos Basin, China, were modified by microwave radiation with different times, and the long-flame coal molecular structure parameters were determined by solid-state ¹³C nuclear magnetic resonance (ss¹³C NMR), Fourier transform infrared (FTIR) spectrometry, and X-ray photoelectron spectrometry (XPS). Atomistic representations of the raw long-flame coal molecular model and modified long-flame coal molecular models were established. The temperature rise, pore volume increase, mineral removal, and functional group changes after the modification have a negative effect on methane adsorption. After the modification, the decrease in surface area of the micropores reduced the adsorption site of methane in coal. As a result, the methane adsorption amount decreased linearly with the decreasing surface area. The CH₄ adsorption isotherms of the long-flame models were dynamically simulated and analyzed. The results of this study can prove that after multiple cycles of microwave modifications, the functional groups in long-flame coal were fractured, and the number of micropores was reduced, which effectively decreased the methane adsorption performance in long-flame coal seams, thereby promoting methane extraction. Microwave modification is a promising method for enhancing CBM recovery. Full article

Occupied and unoccupied electronic states of altermagnetic MnTe(0001) single crystals were studied by photoemission and inverse-photoemission spectroscopies after establishing a reproducible surface cleaning procedure involving repeated sputtering and annealing cycles. The angle-resolved photoemission spectroscopy (ARPES) exhibited a hole-like band dispersion centered at the $\overline{\mathsf{\Gamma }}$ point, which was consistent with the reported ARPES results and our density functional theory (DFT) calculations with the on-site Coulomb interaction U. The observed Mn 3d↑-derived peak at −3.5 eV, however, significantly deviated from the DFT + U calculations. Meanwhile, the Mn 3d↓-derived peak at +3.0 eV observed by inverse-photoemission spectroscopy agreed well with the DFT + U results. Based on simulations of the spectral function employing an w-dependent model self-energy, we found significant relaxation effects in the electron-removal process, while such effects were negligible in the electron-addition process. Our study provides a comprehensive picture of electronic states, forming a solid foundation for understanding the magnetic and transport properties of MnTe. Full article

Solid-state ¹³C NMR spectroscopy using cross-polarization magic-angle spinning is a highly valuable technique for the semi-quantitative analysis of complex solid matrices. One of its key advantages is that it does not require any manipulation of the matrix, such as extractions or other treatments, which is particularly important for preserving the integrity of unstable secondary metabolites. Glucosinolates (β-thioglucoside-N-hydrosulphates) are crucial secondary metabolites specific to Brassica species, and many of them are known to be highly unstable. In this study, we evaluated solid-state nuclear magnetic resonance spectroscopy as an alternative method for the identification and quantification of total glucosinolates in the seeds of Sisymbrium officinale, Brassica napus, Sinapis alba, Brassica nigra, and Moringa oleifera. The results obtained with this method showed good agreement with those from conventional chemical analyses of the seed material. Although, based on a limited number of samples, this preliminary study suggests that the proposed approach could be a useful alternative for quantifying total glucosinolate content in seeds. Full article

We studied the influence of annealing on the magnetic properties and microstructure of ultrathin (metallic nucleus diameter ≈ 5 μm, total diameter ≈ 19 μm) Heusler-type NiMnGa glass-coated microwires prepared using the Taylor–Ulitovsky method. The as-prepared NiMnGa microwires exhibit unexpectedly strong magnetic anisotropy, characterized by a coercivity exceeding 3 kOe at room temperature. Furthermore, their Curie temperature (T_c) lies above room temperature. Additionally, a spontaneous exchange bias of approximately 120 Oe is observed in the as-prepared sample at 100 K. Annealing the microwires leads to a decrease in coercivity, spontaneous exchange bias, and T_c values. Notably, the annealing process shifts the T_c of the samples closer to room temperature, making them more suitable for magnetic solid-state refrigeration applications. Moreover, the hysteresis observed in the temperature dependence of magnetization for the samples annealed for 1 h and 2 h, along with the magnetic softening observed at around 260 K, is attributed to a first-order phase transformation. The observed changes are discussed in the context of internal stress relaxation after annealing, the nanocrystalline structure of both the as-prepared and annealed samples, the recrystallization process, and the magnetic ordering of phases identified in the as-prepared sample and those appearing during recrystallization. The glass coating on microwires offers benefits like better flexibility and resistance to damage and corrosion. However, it is important to recognize that this coating can substantially alter the microwires’ magnetic characteristics. Consequently, precise control over the annealing process is vital to obtain the specific martensitic transformation needed. Full article

Solid-state nuclear magnetic resonance (ssNMR) spectroscopy enables studying complex macromolecules with low solubility. Compared to solution NMR, few tools exist for biomacromolecule ssNMR data analysis. A key challenge is assigning spin systems due to low peak dispersion. Broad peaks from large dipolar couplings and shift anisotropy cause significant overlap and missing peaks. To address this, we introduce ssPINE-POKY, a user-friendly graphical user interface (GUI) integrated into the POKY suite. ssPINE-POKY streamlines the automation of spin system recognition and chemical shift assignment in multidimensional ssNMR spectra by integrating the ssPINE algorithm within an intuitive interface. The platform allows easy and fast job submission, real-time result visualization, and enhanced analysis through additional built-in tools, significantly improving the efficiency of ssNMR data interpretation. Full article

Magnetic pulse welding (MPW) is a promising solid-state joining process that utilizes electromagnetic forces to create high-speed, impact-like collisions between two metal components. This welding technique is widely known for its ability to join dissimilar metals, including aluminum, steel, and copper, without the need for additional filler materials or fluxes. MPW offers several advantages, such as minimal heat input, no distortion or warping, and excellent joint strength and integrity. The process is highly efficient, with welding times typically ranging from microseconds to milliseconds, making it suitable for high-volume production applications in sectors including automotive, aerospace, electronics, and various other industries where strong and reliable joints are required. It provides a cost-effective solution for joining lightweight materials, reducing weight and improving fuel efficiency in transportation systems. This contribution concerns an application for the automotive sector (body-in-white) and specifically examines the welding of AA6082-T6 aluminum alloy with HC420LA cold-rolled micro-alloyed steel. One of the main aspects for MPW optimization is the determination of the process window that does not depend on the equipment used but rather on the parameters associated with the physical mechanisms of the process. It was demonstrated that process windows based on contact angle versus output voltage diagrams can be of interest for production use for a given component (shock absorbers, suspension struts, chassis components, instrument panel beams, next-generation crash boxes, etc.). The process window based on impact pressures versus impact velocity for different impact angles, in addition to not depending on the equipment, allows highlighting other factors such as the pressure welding threshold for different temperatures in the impact zone, critical transition speeds for straight or wavy interface formation, and the jetting/no jetting effect transition. Experimental results demonstrated that optimal welding conditions are achieved with impact velocities between 900 and 1200 m/s, impact pressures of 3000–4000 MPa, and impact angles ranging from 18–35°. These conditions correspond to optimal technological parameters including gaps of 1.5–2 mm and output voltages between 7.5 and 8.5 kV. Successful welds require mean energy values above 20 kJ and weld specific energy values exceeding 150 kJ/m². The study establishes critical failure thresholds: welds consistently failed when gap distances exceeded 3 mm, output voltage dropped below 5.5 kV, or impact pressures fell below 2000 MPa. To determine these impact parameters, relationships based on Buckingham’s π theorem provide a viable solution closely aligned with experimental reality. Additionally, shear tests were conducted to determine weld cohesion, enabling the integration of mechanical resistance isovalues into the process window. The findings reveal an inverse relationship between impact angle and weld specific energy, with higher impact velocities producing thicker intermetallic compounds (IMCs), emphasizing the need for careful parameter optimization to balance weld strength and IMC formation. Full article

This work studies the effect of mesostructured silica–zirconia–tungstophosphoric acid (SiO₂-ZrO₂-TPA) composites used as catalysts in the synthesis of nifedipine by the Hantzsch methodology. The selectivity for nifedipine is determined, along with that of secondary products that may form depending on the reaction conditions. The materials were synthesized via the sol–gel method and characterized by N₂ adsorption–desorption isotherms, infrared spectroscopy (FT-IR), ³¹P solid-state nuclear magnetic resonance (NMR-MAS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), and potentiometric titration. The characterization results from the XPS spectra showed that as the Si/Zr ratio drops, the Si-O-Si signal size decreases, while the Zr-O signal size increases. Characterization by titration indicated that an increase in the total acidity of the material, resulting from support modification with tungstophosphoric acid (H₃PW₁₂O₄₀, TPA), enhances the reaction yield. The catalytic activity in the solvent-free Hantzsch reaction was evaluated under thermal heating and microwave irradiation. The experiments conducted at 80 °C achieved a maximum yield of 57% after 4 h of reaction using the Si20Zr80TPA30 catalyst (50 mg), while by microwave heating, the yield significantly improved, reaching 77% in only 1 h of reaction. This catalyst exhibited stability and reusability without significant loss of activity up to the third cycle. Depending on the type of material and the reaction conditions, it is possible to modify the selectivity of the reaction, obtaining a 1,2-dihydropyridine isomeric to nifedipine. Reaction intermediates and other minor secondary products that may be formed in the process were also evaluated. Full article

Photochromic materials have attracted widespread attention due to their potential applications in optical information storage, optoelectronic devices, and fluorescence probes. As a typical photochromic system, diarylethene derivatives are considered one of the most promising photochromic materials due to their outstanding photostability and significant bistable properties. Based on an aggregation-induced emission (AIE) mechanism, this study employed a molecular structural engineering strategy to design and synthesize a series of diarylethene derivatives containing ethyl benzoate substituents. A systematic investigation of the structure–activity relationship between their photochromic behavior and AIE characteristics revealed a dual-state light response mechanism in the solid and solution states. This study demonstrates that the target compounds exhibited significant photochromic responses under UV–visible light irradiation, with enhanced emission in the solid state compared to the solution state, confirming the remarkable enhancement effect of AIE on aggregation. Structural characterization techniques such as nuclear magnetic resonance spectroscopy (NMR) and high-resolution mass spectrometry (H RMS) were employed to elucidate the correlation between molecular conformation and photophysical properties. Furthermore, these materials demonstrated potential for multi-level anti-counterfeiting, high-density optical storage, and bioimaging applications, providing experimental foundations for the development of novel multifunctional photochromic materials. Full article

Dihydromyricetin, the predominant bioactive constituent in vine tea, manifests diverse bioactivities, including anti-tumoral and anti-inflammatory effects. However, the deep processing of vine tea remains underdeveloped, thereby curtailing its economic benefits. Concurrently, as the demand for organic selenium products escalates, the exploration and development of selenium-containing compounds bearing synergistic effects has emerged as a research frontier. In this investigation, dihydromyricetin underwent selenium modification through a SeO₂- and HCl-catalyzed reaction, leading to the successful synthesis of selenium-modified dihydromyricetin. A comprehensive array of characterization techniques—encompassing Fourier-transform infrared spectroscopy and solid-state nuclear magnetic resonance—was employed for structural elucidation. The results demonstrated that selenium was covalently tethered to the 4’-hydroxyl group of the B-ring of dihydromyricetin via an O-Se-O bond. Activity assays revealed that selenium-modified dihydromyricetin exhibited significantly augmented inhibitory effects on α-amylase and α-glucosidase (p < 0.05) relative to dihydromyricetin, with IC₅₀ values of 0.0459 mg/mL and 0.01728 mg/mL, respectively. Moreover, selenium-modified dihydromyricetin exerted marked inhibitory effects on the proliferation of HepG2 and A549 cells, with IC₅₀ values of 49.05 μg/mL and 515.60 μg/mL, respectively. These findings collectively furnish experimental evidence underpinning the potential application of selenium-modified dihydromyricetin as a functional food ingredient, particularly within blood glucose regulation. Full article

Polysaccharides are important biomolecules, which play a key role in biological, medical, and industrial processes due to their diverse structures and important functions. This paper looks into the significant progress made in the structural and functional analysis of polysaccharides by nuclear magnetic resonance (NMR) spectroscopy. NMR spectroscopy, including solution-state and solid-state technology, has revolutionized this field through detailed molecular insights into the structure, conformation, and dynamics of polysaccharides at the molecular level. There have been some important historical breakthroughs in 1D and 2D NMR, which have led to modern methods like multidimensional NMR and nuclear dynamic polarization (DNP). These modern methods offer a high level of resolution and sensitivity and have made it easier to come up with innovative applications. The applications range from the structural elucidation of microbial and plant structures of polysaccharides to improving food texture, developing therapies, and creating sustainable materials. Despite challenges such as signal overlap and limited sensitivity, emerging solutions are making significant progress. Computational modeling, isotope labeling, and integrated methods that combine complementary technologies are driving the boundaries of polysaccharide research. This review demonstrates the transformative role of NMR in revealing the complexity of polysaccharides and its potential to promote future discoveries and new ideas in the dynamic field. Full article

Ceramic samples of CuCr_1−xY_xO₂ (x = 0–0.02) were synthesized via the high temperature solid-state reaction method, and the influence of Y³⁺ doping on their microstructure and antiferromagnetic phase transitions was systematically investigated. Y³⁺ doping increased the unit cell volume from 130.928 ų for x = 0 to 131.147 ų for x = 0.0200, and the average grain size decreased from 3.38 μm for x = 0 to 4.27 μm for x = 0.0200. The Cr and Y elements maintained +3 valence, while the Cu element had +1 valence. All samples showed obvious paramagnetism when the temperature was higher than 140 K. When the temperature continued to decrease, the lattice expansion changed the bond length and bond angle of the Cr-O-Cr bond, resulting in a change in the superexchange interaction, and the magnetic susceptibility increased significantly, gradually showing antiferromagnetism. The T_N of the undoped sample was about 46 K, the T_N of the doped sample with x = 0.0175 was about 21 K, and the T_N of other doped samples was about 30 K. This result indicates that Y³⁺ doping enhanced the antiferromagnetism of the sample but also weakened its antiferromagnetic stability. Full article

The application of biochar to traditional soil and soilless growth media in agriculture has been reported to increase plant production. However, it remains unclear which biochar component drives this process or which biogeochemical process is attributed to better plant productivity. Therefore, this study aims to determine how biochar organic carbon (C) composition and thermal stability influence nitrogen availability and tomato production. Soilless growth media composed of a mixture of 60% and 40% coconut coir (CC) (Cocos nucifera L.) and fine pine bark (PB) (Pinus genus), respectively, was amended with 0, 1, 2, 3, 4, 6, 8, 10, and 12% biochar per dry weight. The amended media were used to grow Red Bounty tomatoes (Lycopersicum esculentum) for three months. After harvesting tomatoes and determining yield, organic C composition and C thermal stability of the biochar amended soilless growth media mixtures were determined using solid-state ¹³C nuclear magnetic resonance (¹³C NMR) and multi-elemental scanning thermal analysis (MESTA), respectively. Thermal stability data were used to determine the “R400 index”, and nitrate (NO₃⁻) concentration was determined using the water extractable method. Results showed that biochar-amended media significantly increased pH (p < 0.0001) and NO₃⁻ (p = 0.0386) compared to the no-char control. Biochar amended soilless media organic C composition was dominated by O-alkyl-C as a result of a higher fraction of soilless media; however, total C, carboxyl-C, phenolic-C, and aromatic-C increased with increasing biochar content and related negatively to R400, which decreased with increasing biochar content. Nitrate retention and tomato yield increased with increasing total C, carboxyl-C, phenolic-C, and aromatic-C and decreasing R400. This indicates that the stable form of C, carboxyl-C, phenolic-C, aromatic-C, and low R400 enhanced NO₃⁻ sorption, reducing leaching and enhancing its availability for tomato growth. Full article

In this work, we studied the thermal behavior and infrared fingerprint of anhydrous and hydrated DL-tartaric acid via conventional and modulated Differential Scanning Calorimetry (DSC), Thermogravimetry (TGA), Fourier Transform Infrared Spectroscopy (FTIR), nuclear magnetic resonance (NMR), pH measurements, and ab initio density functional theory (DFT) calculations. Six samples were examined in total (raw, recrystallized from D₂O solution, freeze-dried, and three heated samples). The results reveal that both forms (anhydrous and hydrated) do not exhibit melting prior to decomposition. It is also shown that the so-called DL-tartaric acid does not exist in the solid state in pure form, but it contains water and a tartaric acid oligomer, which is produced through esterification. Alteration of the chemical structure (reflected through decomposition) is initiated at quite low temperatures and is more pronounced for the hydrated form. Up to 75 °C, decomposition proceeds through esterification, while at higher temperatures it seems to be reversed due to the increase in water and decrease in COOH groups emerging through anhydride formation. Either upon heating or at sub-zero temperatures during freeze-drying, the hydrated form decomposes, and although some water is removed, new water is produced due to esterification. The conclusions are also supported by DFT calculations. Full article