jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: DK Jha
Source: International Journal of Chemical Research and Development (article, 2026-03-01)
Field: Chemistry — Physical and Theoretical Chemistry

σ-Aromatic Stabilization of a Be₄ Core by NH Ligands: DFT Study Beryllium-based clusters exhibit diverse bonding motifs, ranging from weak van der Waals interactions in small aggregates to metallic-like delocalization in larger species. This paper presents a detailed investigation of the structural, thermodynamic, and electronic properties of the Be₄N₂H₂ cluster using density functional theory (DFT) at the TPSS/def2-TZVP and M06-2X/def2-TZVP levels of theory, augmented by high-level domain-based local pair natural orbital coupled-cluster (DLPNO-CCSD(T)) local energy decomposition (LED) analysis. Geometry optimization identifies a stable isomer featuring a compact Be₄ core coordinated by two NH units. Energy decomposition analysis combined with natural orbitals for chemical valence (EDA-NOCV) reveals a remarkably strong orbital interaction energy (ΔEorb = −370.62 kcal/mol), dominated by σ-type donation. High-level LED calculations quantify the dispersion contribution at approximately −5.7 kcal/mol. Kinetic stability is supported by a substantial HOMO-LUMO gap and the absence of imaginary vibrational frequencies. The bonding was further elucidated using Natural Bond Orbital (NBO) analysis, Adaptive Natural Density Partitioning (AdNDP), and topological methods including Interaction Region Indicator (IRI), Density Overlap Regions Indicator (DORI), Localized Orbital Locator (LOL), and delocalization indices (SEDI/DI), confirming σ-aromaticity and multicentre bonding in the Be₄ core. Natural bond orbital ; Delocalized electron ; van der Waals force ; Density functional theory ; Atomic orbital ; Orbital overlap ; Cluster (spacecraft) ; Molecular orbital ; Valence (chemistry) Crystallography and molecular interactions ; Synthesis and characterization of novel inorganic/organometallic compounds ; Organoboron and organosilicon chemistry
Authors: Kenan Can Tok
Source: Ankara Universitesi Eczacilik Fakultesi Dergisi (article, 2026-01-13)
Field: Chemistry — Analytical Chemistry

STABILITY INDICATING ANALYTICAL METHOD DEVELOPMENT AND VALIDATION OF HPLC FOR PREGABALIN QUANTIFICATION IN BULK AND PHARMACEUTICAL DOSAGE FORMULATIONS Objective: To develop and validate a rapid, sensitive, and cost-effective HPLC-UV method for the quantification of pregabalin (PRG) in both bulk drug substance and pharmaceutical dosage formulations, addressing the growing need for robust analytical techniques in pharmaceutical quality control and forensic toxicology. Material and Method: An HPLC-UV method was developed using an Agilent 1100/1200 system equipped with a UV detector and a Merck monolithic silica column (100 mm x 4.6 mm). The mobile phase consisted of acetonitrile and water (5:95, v/v) adjusted to pH 7.0 with orthophosphoric acid and sodium hydroxide, at a flow rate of 2.0 ml/min and a column temperature of 45°C. UV detection was set at 200 nm. The method was validated according to ICH Q2(R1) guidelines, evaluating linearity, sensitivity, accuracy, precision, recovery, and stability-indicating properties through forced degradation studies. Result and Discussion: The developed HPLC-UV method demonstrated rapid analysis with a pregabalin retention time of 1.44 minutes and a total run time under 2 minutes. System suitability parameters met pharmacopeial requirements. The method exhibited excellent linearity in the range of 1 to 150 µg/ml (R² &amp;gt; 0.999), with LOD and LOQ values of 0.25 µg/ml and 0.76 µg/ml, respectively. Intra-day and inter-day accuracy ranged from 96.09% to 99.68% and 95.07% to 98.78%, respectively, with RSD values for precision consistently below 2.22%. Recovery from pharmaceutical formulations was between 99.0% and 101.75%. Forced degradation studies revealed that pregabalin is stable under acidic, oxidative, and thermal stress conditions, as well as during freeze-thaw and autosampler storage, but is susceptible to base hydrolysis. The validated HPLC-UV method is demonstrated to be rapid, accurate, precise, and stability-indicating, making it suitable for routine quality control of pregabalin in pharmaceutical products and for forensic applications. Forced degradation ; Acetonitrile ; Pregabalin ; Dosage form ; Pharmaceutical formulation ; High-performance liquid chromatography ; Linearity ; Active ingredient Analytical Methods in Pharmaceuticals ; Forensic Toxicology and Drug Analysis ; Analytical Chemistry and Chromatography
Authors: Yunxuan Zhou | Liangjuan Gao | Quanhui Hou | Jun Tan | Zhao Ding
Source: Materials (article, 2026-01-30)
Field: Materials Science — Biomaterials

Atomic-Scale Insights into Alloying-Induced Interfacial Stability, Adhesion, and Electronic Structure of Mg/Al3Y Interfaces This work aims to enhance the stability of the Mg/Al<sub>3</sub>Y interface through first-principles investigations of low-cost dopants. Density functional theory calculations were employed to systematically examine the bulk properties of Mg and Al<sub>3</sub>Y, as well as the structural stability, electronic characteristics, and alloying element effects at the Mg(0001)/Al<sub>3</sub>Y(0001) interface. The calculated lattice parameters, elastic moduli, and phonon spectra demonstrate that both Mg and Al<sub>3</sub>Y are dynamically stable. Owing to the similar hexagonal symmetry and a small lattice mismatch (~1.27%), a low-strain semi-coherent Mg(0001)/(2 × 2)Al<sub>3</sub>Y(0001) interface can be constructed. Three representative interfacial stacking configurations (OT, MT, and HCP) were examined, among which the MT configuration exhibits significantly higher work of adhesion, indicating superior interfacial stability. Differential charge density and density of states analyses reveal pronounced charge transfer from Mg to Al/Y atoms and strong orbital hybridization, particularly involving Y-d states, which underpins the enhanced interfacial bonding. Furthermore, the segregation behavior and adhesion enhancement effects of typical alloying elements (Si, Ca, Ti, Mn, Cu, Zn, Zr, and Sn) were systematically evaluated. The results show that Mg-side interfacial sites, especially Mg<sub>2</sub> and Mg<sub>3</sub>, are thermodynamically favored for segregation, with Zr and Ti exhibiting the strongest segregation tendency and the most significant improvement in interfacial adhesion. These findings provide fundamental insights into interfacial strengthening mechanisms and offer guidance for the alloy design of high-performance Mg-based composites. Density functional theory ; Stacking ; Electronic structure ; Alloy ; Phonon ; Lattice (music) ; Charge density ; Work (physics) Magnesium Alloys: Properties and Applications ; Aluminum Alloys Composites Properties ; Microstructure and mechanical properties
Authors: Judith Wolff | Daniela C. Rößler | Anna‐Christin Joel | Vincent Jackel | Sebastian Büsse | Peter Michalik | Martín J. Ramírez
Source: Proceedings of the National Academy of Sciences (article, 2026-01-26)
Field: Materials Science — Biomaterials

Behavioral tuning of spider silk thread stiffness circumvents biomaterial trade-offs Biological polymers often face a trade-off between stiffness, strength, and extensibility: Materials that are strong and stiff tend to be brittle, while those that are elastic and extensible usually lack strength. Here, we show that netcasting spiders (Deinopidae) overcome this trade-off by forming mixed-silk metastructures, which enable both high elastic deformation and load resistance. These spiders have evolved a unique predatory strategy, casting a sticky silk web over prey, which subjects the web radii to extreme strains far exceeding those sustained by typical spider silk fibers. The radii consist of a compound filament with an elastomeric core surrounded by looped bundles of thin fibers. This architecture results in an unusual mechanical profile: The threads are initially compliant and highly extensible, but they stiffen as the fiber loops straighten, enhancing load-bearing capacity. Notably, spiders control this compound architecture through a reel-spinning technique, controlling loop formation and fiber mixture to establish an elasticity gradient across the web-stiff and strong in the main frame lines, yet soft and hyperelastic in the lower radii that undergo the greatest deformation during prey capture. These findings represent a unique case of behavioral modulation of silk processing to circumvent biomaterial trade-offs, enabling extraordinary dynamics and specialization of web architecture. The herein described principle of looped fiber-reinforced elastomers may also be transferred to the design of artificial materials for applications that require both high elasticity and strength. Elastomer ; Stiffness ; SILK ; Thread (computing) ; Elasticity (physics) ; Spider silk ; Extensibility ; Biomaterial Silk-based biomaterials and applications ; Calcium Carbonate Crystallization and Inhibition ; Advanced Materials and Mechanics
Authors: Jing Liu | Gong Cheng | Jiejie Jiao | Jiaxin Hu | Bingsong Zheng | Daoliang Yan
Source: BMC Plant Biology (article, 2026-02-11)
Field: Chemistry — Analytical Chemistry

The effects of nitrogen and phosphorus deficiency on the main physiology of Ilex chinensis and transcriptomic analysis Our data reveal the integrated physiological and transcriptional adjustments that allow I. chinensis to cope with N and P deficiency stress, and identifies potential target genes for improving nutrient use efficiency. These findings provide new insights into the physiological and molecular responses of I. chinensis to N and P deficiency stress and offer valuable information for optimizing its cultivation under nutrient-limited conditions. Transcriptome ; Phosphorus deficiency ; Phosphorus ; Nutrient ; Nutrient deficiency ; Nitrogen deficiency ; Nitrogen ; Fight-or-flight response Heavy Metals in Plants ; Plant nutrient uptake and metabolism ; Plant Micronutrient Interactions and Effects
Authors: Kaveri T. Vaditake | Atul A. Shirkhedkar Atul A. Shirkhedkar
Source: Future Journal of Pharmaceutical Sciences (article, 2026-01-12)
Field: Chemistry — Analytical Chemistry

Rapid RP-HPLC optimization for efficient determination of nebivolol hydrochloride in bulk and tablet dosage form: application of Box-Behnken design Abstract Background Nebivolol hydrochloride (NBH) is a β-blocker known for its vasodilatory effects. According to the literature, it is commonly used to treat hypertension. Detecting drug molecules in bulk and tablet forms using statistical design is of significant importance in analytical science. Therefore, the objective of this work was to apply statistical experimental design principles to analyze NBH, utilizing a Box-Behnken design (BBD) to optimize the mobile phase composition. Results In this work, NBH was separated using an Inertsil ODS-3 V column with an optimized mobile phase consisting of 40:60% v/v acetonitrile (ACN) and 0.1% trifluoroacetic acid (TFA) in HPLC-grade Milli-Q water. The flow rate was programmed at 1 mL/min, and the column oven temperature was set at 40 °C ± 1 °C. Here, measurement was performed at 282 nm, with a retention time (Rt) of 5.41 min. Analysis of NBH in the marketed tablet formulation (Nebistar 10 mg) showed that the percentage of the labeled claim was consistent with the actual label claim. Additionally, the established method was validated in accordance with ICH guidelines. Conclusion The liquid chromatographic procedure developed is precise, accurate, and reliable, as indicated by %RSD values of less than 2%. As a result, it demonstrates significant potential for broad application in the analysis of NBH in both bulk and tablet formulations. Graphical Abstract Trifluoroacetic acid ; Design of experiments ; Theoretical plate ; Statistical analysis ; Dosage form ; Volumetric flow rate Analytical Methods in Pharmaceuticals ; Analytical Chemistry and Chromatography ; Analytical chemistry methods development
Authors: Zhongkai Huang | Xinyu Wang | Xiaodong Deng | Liang Deng | Maolin Bo | Chuang Yao | Haolin Lu | Guankui Long
Source: Surfaces (article, 2026-01-01)
Field: Materials Science — Materials Chemistry

Exploring the Electronic Landscape of Two-Dimensional Tin Monoxide: Layer Thickness and Crystallographic Symmetry Effects The ability to precisely control the electronic bandgap is crucial for tailoring two-dimensional (2D) materials for optoelectronic applications. In this work, we systematically investigate the electronic structure of 2D tin monoxide (SnO) across various layer thicknesses (monolayer to tetralayer) and crystallographic symmetries using first-principles calculations. Our results reveal a strong dependence of the bandgap on the number of layers, which decreases dramatically from 3.94 eV in the monolayer to nearly metallic in the tetralayer. Furthermore, different space group symmetries are found to significantly influence the bandgap, providing an additional degree of freedom for property tuning. This bandgap engineering is quantitatively linked to enhanced interlayer electronic coupling, as evidenced by a progressive increase in interlayer charge transfer with layer count. Our findings establish a clear structure–property relationship and offer practical guidance for designing SnO-based devices in flexible electronics and tunable optoelectronics. Band gap ; Tin ; Layer (electronics) ; Symmetry (geometry) ; Monolayer ; Electronic structure ; Electronics ; Homogeneous space ; Electronic band structure 2D Materials and Applications ; ZnO doping and properties ; Nanowire Synthesis and Applications
Authors: Haley N. Monacchio | Ritika S. Shah | Christian F. Montes | Grace Z. Wang | Justin W. Walley | Chelsey M. VanDrisse
Source: ACS Infectious Diseases (article, 2026-02-16)
Field: Chemistry — Organic Chemistry

Bioorthogonal Click Chemistry for Antibody-Free Profiling of Acetylation, Propionylation, and Butyrylation in <i>Pseudomonas aeruginosa</i> and Methicillin-Resistant <i>Staphylococcus aureus</i> Lysine acylation is a posttranslational modification (PTM) conserved in all domains of life and is essential for regulating diverse biological processes. Traditional methods for investigating acylation rely on anti-acyl-lysine antibodies, which are costly and time-consuming and often exhibit variable affinity. To remedy these pitfalls, we developed an antibody-free method for bacterial acylome enrichment using bioorthogonal click chemistry coupled with tandem mass spectrometry. We applied this approach to the pathogens <i>Pseudomonas aeruginosa</i> and methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) to explore the biological significance of acylation in each organism. We characterized the acetylome, propionylome, and butyrylome in <i>P. aeruginosa</i> UCBPP-PA14 and the acetylome and propionylome in MRSA. Comparative analyses revealed unique PTM dynamics showing that acylation regulated a wide range of cellular functions, including metabolism, antibiotic resistance, virulence, and stress response. This work establishes the first antibody-free enrichment method for defining bacterial acylomes and provides new insight into global lysine acylation networks in pathogenic bacteria. Bioorthogonal chemistry ; Acylation ; Lysine ; Click chemistry ; Profiling (computer programming) ; Chemical biology ; Bacterial protein Click Chemistry and Applications ; Biochemical and Structural Characterization ; Antimicrobial agents and applications
Authors: Dongmei Hu | Sihao Deng | Ying Sun | Kewen Shi | Christoph Sürgers | G. Fischer | Bao Yuan | Xudong Shen | Dexiang Gao | Zonglun Li | Le Kang | Cong Wang
Source: iScience (article, 2026-03-10)
Field: Materials Science — Materials Chemistry

Tunable exchange bias, magnetoelectric transport and negative thermal expansion in Mn3Ni1-Co N Antiperovskite materials have significant potential in spintronics due to distinctive magnetic and electronic transport characteristics. This work systematically investigates the effects of Co substitution on the magnetic, electronic transport, and thermal expansion properties of Mn<sub>3</sub>Ni<sub>1-<i>x</i></sub> Co <sub><i>x</i></sub> N. Co substitution triggers a transformation from noncollinear antiferromagnetic to ferrimagnetic ordering. For <i>x</i> = 0.5, a pronounced exchange bias is observed, with a maximum exchange bias field of 7.44 kOe at 25 K and coercivity reaching 9.45 kOe at 75 K. This effect significantly modulates the anomalous Hall effect, providing clear evidence for spin-charge coupling in antiperovskites. All samples exhibit negative thermal expansion near magnetic transitions, with coefficients ranging from -65.64 × 10<sup>-6</sup> K<sup>-1</sup> (<i>x</i> = 0) to -23.55 × 10<sup>-6</sup> K<sup>-1</sup> (<i>x</i> = 0.7), revealing intrinsic correlations between magnetic transitions and lattice dynamics. This work advances the understanding of magnetic ordering mechanisms in antiperovskite materials and provides a basis for designing functional materials with tunable magnetic properties. Thermal expansion ; Negative thermal expansion ; Thermal ; Energy exchange ; Exchange interaction Thermal Expansion and Ionic Conductivity ; Magnetic and transport properties of perovskites and related materials ; Heusler alloys: electronic and magnetic properties
Authors: Ahmed Belguenoune | Nadir Ouldhamadouche | Salah Bassaid | Abdelkader dehbi | Mohamed Gargouri | Abdallah Ben rhaiem
Source: Journal of Sol-Gel Science and Technology (article, 2026-03-24)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Enhanced dielectric and charge transport behavior in La1-xBixFeO3 ceramics: role of low-level Bi substitution The structural and dielectric properties of La1-xBixFeO3 ceramics (x = 0, 0.025, 0.05, 0.10, 0.15), synthesized via the sol–gel method, were investigated to assess their potential for electronic applications. X-ray diffraction (XRD) and Rietveld refinement confirmed a single-phase orthorhombic structure (Pbnm), with an increase in crystallite size from 32.25 to 55.58 nm and minimal lattice distortion due to the comparable ionic radii of Bi3+ and La3+. Raman spectroscopy revealed shifts and broadening in low-frequency Ag modes ( <200 cm–1), indicating enhanced structural disorder attributed to the distinct electronic configuration of Bi3+. SEM observations revealed that Bi substitution promotes grain growth, evolving from highly agglomerated particles in the undoped sample to well-developed micrometer-scale grains for x ≥ 0.05. EDX analysis confirmed the expected elemental composition and effective Bi incorporation into the lattice. Dielectric measurements over the 10 Hz–1 MHz frequency and 40–120 °C temperature ranges showed improved performance with Bi substitution. Nyquist plots displayed semicircular arcs associated with grain and grain boundary effects. Impedance analysis confirmed thermally activated conduction, while electric modulus (M″) spectra revealed non-Debye relaxation with grain boundary contributions. The activation energy for grain boundary relaxation decreased from 0.44 eV (x = 0) to 0.34 eV (x = 0.05), then increased at higher doping levels. The dielectric constant nearly doubled at x = 0.05, attributed to reduced relaxation energy and enhanced interfacial polarization. AC conductivity followed a similar trend, peaking at x = 0.05. The temperature-dependent frequency exponent (s) confirmed that the conduction mechanism follows the correlated barrier hopping (CBH) model. Additionally, the density of localized states (NT) and hopping distance (Rω) were analyzed as functions of frequency and temperature, providing further insights into charge transport dynamics. La0.95Bi0.05FeO3 exhibited optimal dielectric and transport behavior, demonstrating the potential of low-level Bi substitution for electronic applications. Grain boundary ; Dielectric ; Rietveld refinement ; Dielectric spectroscopy ; Raman spectroscopy ; Analytical Chemistry (journal) ; Crystallite ; Orthorhombic crystal system ; Nyquist plot Multiferroics and related materials ; Dielectric properties of ceramics ; Magnetic Properties and Synthesis of Ferrites
Authors: Dongmei Hu | Sihao Deng | Ying Sun | Kewen Shi | Christoph Sürgers | G. Fischer | Bao Yuan | Xudong Shen | Dexiang Gao | Zonglun Li | Le Kang | Cong Wang
Source: Repository KITopen (Karlsruhe Institute of Technology) (article, 2026-01-01)
Field: Materials Science — Materials Chemistry

Tunable exchange bias, magnetoelectric transport and negative thermal expansion in Mn₃Ni$_{1-x}$Co$_{x}$N Thermal expansion ; Thermal ; Negative thermal expansion ; Work (physics) ; Ferromagnetism Thermal Expansion and Ionic Conductivity ; Magnetic and transport properties of perovskites and related materials ; Heusler alloys: electronic and magnetic properties
Authors: Qing Li | Jianping Sun | Steffen Bötzel | Mengjun Ou | Zhe‐Ning Xiang | Frank Lechermann | Bosen Wang | Yi Wang | Ying-Jie Zhang | Jinguang Cheng | I. M. Eremin | Hai-Hu Wen
Source: Nature Communications (article, 2026-02-27)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Enhanced superconductivity in the compressively strained bilayer nickelate thin films by pressure Recently, superconductivity with onset transition temperature (T<sub>c</sub><sup>onset</sup>) over 40 K was achieved in La<sub>3</sub>Ni<sub>2</sub>O<sub>7</sub> and (La<sub>,</sub>Pr)<sub>3</sub>Ni<sub>2</sub>O<sub>7</sub> thin films at ambient pressure due to in-plane compressive strain. However, the T<sub>c</sub> in these thin films are lower than that of the bulk bilayer nickelates under pressure. Here we report the enhancement of T<sub>c</sub><sup>onset</sup> from about 30 K to over 48 K by applying hydrostatic pressure on the compressively strained bilayer nickelate thin films. The T<sub>c</sub><sup>onset</sup> firstly ramps up with pressure, then it slightly drops down after reaching the maximum T<sub>c</sub><sup>onset</sup> at about 48.5 K. Our theoretical calculations yield a cooperative enhancement of magnetic fluctuations between and within the layers and increased metallicity under pressure. These findings highlight the critical role of the interplay between interlayer and intralayer electronic correlations in bilayer nickelate superconductors and point to the potential of tuning T<sub>c</sub> through controlled manipulation of the electronic structure and interactions. Bilayer ; Superconductivity ; Thin film ; Hydrostatic pressure ; Yield (engineering) ; Hydrostatic equilibrium ; Superconducting transition temperature Magnetic and transport properties of perovskites and related materials ; Physics of Superconductivity and Magnetism ; Advanced Condensed Matter Physics