Tryptophan-2'-carboxylate derivative possessing pyrido[3,4-b]indole core was discovered in the unique bioluminescent system of the Henlea earthworms, and its structure was confirmed by the independent synthesis. The synthetic compound exhibits the characteristic 300 nm absorption and can be proposed as a candidate for oxyluciferin or a related oxidized luciferin product.
The C4=C5 double bond of 2-aminooxazole serves as dienophile in the course of inverse electron-demand Diels- Alder reactions with 1,2,4-triazines. The primary tricyclic adducts would lose dinitrogen molecule to form fused oxazolopyridine core whose aminooxazoline moiety undergoes extrusion of HOCN species, which finally leads to 3- or 4-aminopyridines. The regioselectivity of the process is governed by the substitution pattern of the triazine core.
Acute ischemic stroke (AIS) analysis from two-dimensional (2D) clinical imaging is hindered by uncontrolled slice tilt and geometric inconsistencies that violate the assumptions of pose-agnostic deep learning (DL) models. This paper proposes a unified geometry-aware, frequency-domain framework for tilted slice localization and ischemic stroke segmentation that explicitly decouples pose estimation from lesion analysis. The method first recovers the full six-degree-of-freedom (6-DoF) rigid pose of arbitrarily tilted slices using frequency-domain slice-to-volume registration, converting a geometrically ill-posed segmentation problem into an anatomically normalized one. Building on this normalization, a frequency-domain segmentation network is introduced that exploits Hermitian symmetry and discriminative spectral bands to enhance sensitivity to ischemic tissue, complemented by a teacher-student knowledge distillation (KD) strategy to improve generalization. Extensive experiments on four public benchmark datasets across multiple imaging modalities demonstrate consistent state-of-the-art (SOTA) performance under controlled geometric variability, with notable improvements on the clinically critical core-penumbra segmentation task and preliminary evidence of robustness to certain domain shifts. The results confirm that explicit geometric modeling combined with spectral-domain analysis provides a robust foundation for medical image segmentation under controlled geometric variability.
In this study, a novel CoZnAl-LDH coating was synthesized in-situ on anodized aluminum through a hydrothermal method without introducing trivalent metal salts. Subsequently, a vanadate-intercalated LDH-VS coating was fabricated via ion exchange and hexadecyltrimethoxysilane (HDTMS) self-assembly, which integrated longterm corrosion resistance, friction reduction, and superhydrophobicity into a single coating. The morphology and structure of the coatings were investigated using SEM, EDS, XRD, FT-IR, and XPS. The coating performance was evaluated through scratch tests, contact angle, electrochemical, and friction wear tests. The results demonstrated that the contact angle of the LDH-VS increased from 26 degrees to 154 degrees and remained above 120 degrees even after prolonged immersion, exhibiting outstanding self-cleaning and antifouling properties. After 28 days of immersion in 3.5 wt % NaCl solution, the corrosion current density of LDH-VS decreased by four orders of magnitude to 8.09 x 10(-9) A.cm(- 2) compared to bare aluminum alloy and the microstructure remained intact, indicating excellent long-term corrosion resistance. Friction tests confirmed the superior friction reduction of the modified coating, with the average friction coefficient of LDH-VS decreasing to 0.28, significantly lower than that of the aluminum alloy. Scratch tests also verified the coating's excellent adhesion strength. This study provides new insights into the development and application of LDH in superhydrophobicity, long-term corrosion protection, and wear resistance.
The widespread use of carbamazepine (CBZ) as an anticonvulsant poses common side effects, health risks, and significant environmental concerns, necessitating the development of sensitive and efficient detection platforms. While metal oxide nanomaterials are known, the potential of beryllium, magnesium, and calcium oxide nanoclusters (Be12O12, Mg12O12, and Ca12O12) as electrochemical sensors for CBZ remains unexplored. This study presents the first comprehensive density functional theory (DFT) investigation into these nanoclusters for this purpose. Thermodynamic analyses confirmed spontaneous and exothermic adsorption processes across all nanoclusters. While Ca12O12 exhibited the strongest adsorption energy (−49.71 kcal mol−1), the Be12O12 nanocluster demonstrated superior sensing characteristics. It showed the most significant change in the energy gap (
