This study aimed to comparatively evaluate the effectiveness of different irrigation solutions and activation techniques in removing calcium hydroxide (CH) from standardized artificial grooves located in the apical third of root canals. Ninety extracted single-rooted human maxillary central incisors were instrumented using a standardized preparation protocol. Artificial grooves were created in the apical third of split roots and filled with CH paste. Specimens were randomly divided into two irrigation groups: 1.5% sodium hypochlorite (NaOCl) + 0.1% octenidine dihydrochloride (OCT) or 1.5% NaOCl + 17% ethylenediaminetetraacetic acid (EDTA). Each group was further subdivided according to the activation technique: conventional needle irrigation (CNI), passive ultrasonic activation (PUA), or laser-activated irrigation (LAI). Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction (α = 0.05). Significant differences were observed among the groups (p < 0.001). OCT combined with PUA showed the lowest residual CH scores and performed significantly better than OCT + CNI. OCT demonstrated superior CH removal compared with EDTA under CNI and PUA conditions. The OCT + PUA protocol was the most effective approach for CH removal.

The biosynthetically prepared metal oxide nanoparticles, which function effectively as antimicrobial agents, are used considerably to lessen the harmful effects posed by microorganisms that have become antibiotic-resistant and have kept spreading ever more on a vast scale in environments. The increasing adversity in the biomedical field necessitates the development of materials that fulfill biomedical requirements, and biosynthesized nanoparticles have received significant attention, as they offer substantial benefits by being biocompatible-the critical parameter in need. This review explores assorted metal oxide nanoparticles like aluminum oxide, bismuth oxide, cadmium oxide, cobalt oxide, copper oxide, iron oxide, magnesium oxide, manganese oxide, nickel oxide, samarium oxide, silver oxide, titanium oxide, tin oxide, and zinc oxide; synthesis methods assisted with biomolecules, including doped metal oxides and their nanocomposites; and it also investigates their physicochemical properties, factors affecting antimicrobial efficacy, and potential to replace conventional antibiotics. The main objective is to provide an in-depth review of biomolecule-assisted metal oxide nanoparticles as effective, sustainable, and promising antimicrobial agents for promoting good health.

Thulium is a heavy lanthanide and the second-least abundant rare-earth element in the lanthanide series. Out of 35 isotopes of thulium, only two isotopes, [171]Tm and [170]Tm, have relatively longer half-lives of 701 days and 128 days, respectively, and [169]Tm is the most stable isotope of thulium. The longest half-life of [170]Tm provides its logistical benefit to supply thulium worldwide without losing its activity. [170]Tm is expected to cause low bone marrow toxicity because it has lower beta energy than other radionuclides. Thulium can be a promising radionuclide for bone pain palliation, considering its half-life as well as beta and gamma radiation. A thulium-based laser is used in the resection of tumours and has limited application as a diagnostic agent in the military, medicine, and meteorology. The well-tolerated dose of the thulium-EDTMP complex is 370 MBq in a patient having bone pain associated with skeletal metastasis. This article aims to review and discuss the current state of knowledge on the ecotoxicological, toxicological, and pharmacological properties of thulium and provide a foundation for further research on thulium as a bone pain palliator.

Divalent samarium reagents, particularly samarium diiodide (SmI2), have long been recognized as the most powerful and versatile single-electron reductants in organic synthesis. Several catalytic strategies have been developed for Sm(II) chemistry over the past three decades, including approaches based on metal co-reductants, electrochemical reduction, and radical relay mechanisms. Photochemical strategies have recently emerged as new platforms for catalytic Sm(II) chemistry, leading to the development of a broad range of reductive transformations. This review highlights the recent progress in the photochemical generation of Sm(II) species and their applications in organic synthesis.

Diffuse reflectance spectroscopy was used to study undoped and Sm-doped CeO2nanoparticles prepared by sol-gel and ball-milling routes, and to probe radiation damage induced by swift heavy ions. Kubelka-Munk analysis of UV-vis-NIR spectra reveals nine Sm3+4f-4f absorption bands within the wide O 2p-Ce 4f band gap, with intensities that increase with Sm content and remain broad owing to low local symmetry and native disorder. Under 946 MeV Au irradiation up to 5 × 1012cm-2, ball-milled Sm-doped samples exhibit a systematic fluence-dependent decrease of Sm3+band intensities, without significant changes in bandwidth or peak positions, indicating that irradiation primarily weakens the local crystal field rather than altering site multiplicity. In parallel, the Urbach energy of the absorption edge increases, providing an optical measure of disorder build-up and yielding approximate damage cross sections consistent with electronically driven track formation. A weak Ce3+4f-5 d band near 15 000 cm-1appears in irradiated undoped CeO2but is absent in Sm-doped samples, in agreement with oxygen-potential pinning by charge-compensating vacancies. Overall, the data indicate that Sm3+absorption bands are sensitive optical probes of irradiation-induced disorder in nanocrystalline ceria and highlight the utility of rare-earth dopants for tracking radiation damage in fluorite-type oxide nanoparticles.

Acquiring an amphiphobic nanocalcium carbonate (NCC) is a perplexing problem in the long term because of its hydrophility. This restricts its application in self-cleaning coatings and other super-low surface energy engineering fields. This study offers a novel and simple approach that endows NCC with an amphiphobic property through surface modification using perfluoropolyether carboxylic acid in the presence of sodium hydroxide. The modification process was optimized at a 5 wt% modifier concentration, 50 °C, and a duration of 40 min. Comprehensive characterization was performed using FT-IR, TG-DTA, SEM, HR-TEM, NMR and XPS techniques, in contrast with the previous literature describing hydroxyl groups. Notably, FT-IR analysis indicates that no hydroxyl groups were detected on the NCC surface. The modification mechanism involves COO[-] groups from the modifier forming Ca-O ionic bonds with calcium sites on the NCC surface. HR-TEM analysis revealed an exceptionally thin modifier film (2-5 nm) on the NCC surface. Despite this minimal thickness, it endows NCC with remarkable amphiphobic properties, with water and oil contact angles up to 120.4° and 139.9°, respectively. These findings expand insights into the surface modification mechanism of NCC and its potential application fields.

Lunar soil-based geopolymers are promising in situ construction materials, but their reliance on Earth-transported alkali activators limits sustainability. This study developed a nano-SiO2-modified simulated lunar soil-based geopolymer (NS-SLSG) with reduced activator demand by optimizing sodium hydroxide (SH), calcium hydroxide (CH), and sodium silicate (SS). Inductively coupled plasma atomic emission spectrometry (ICP-AES), orthogonal testing, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermogravimetry-differential scanning calorimetry-derivative thermogravimetry (TG-DSC-DTG), Energy-dispersive X-ray spectroscopy (EDS), and Mercury intrusion porosimetry (MIP) were used to evaluate apparent elemental-release characteristics, flowability, mechanical properties, and microstructure. The experimental results indicated that the measured Al and Si concentrations were particularly sensitive to the SH dosage; SH and SS exerted comparatively greater effects on flowability, whereas SH and CH had greater effects on mechanical performance. Adding 0.75 wt.% NS reduced the total admixture mass in the experimental formulation by 23.9% while increasing compressive and flexural strengths by 26.0% and 19.5% to 36.15 and 8.26 MPa, respectively. Microstructural results suggested that SH promoted depolymerization, while CH may have enhanced Ca[2+]-assisted polycondensation, with corresponding variations in gel composition and pore structure. These findings indicate a viable strategy for improving the resource efficiency of lunar construction materials.

Fluoride contamination in water sources poses significant risks to human health and ecosystems, necessitating effective treatment strategies. This study investigates the influence of calcium chloride (CaCl2) and the basicity of polyaluminum chloride (PAC) on fluoride removal using PAC-PDMDAAC coagulation. Through systematic jar tests, the effects of varying PAC basicity (0.5, 1.0, and 2.0) and CaCl2 addition sequences were examined under different fluoride concentrations (1.0, 3.0, and 10.0 mg/L). Results indicate that PAC with lower basicity (B = 0.5) exhibits superior fluoride removal efficiency, showing an increase of 20%-40% compared to PAC (B = 2.0), primarily due to the electro-neutralization mechanism of monomeric aluminum species (Ala). The introduction of PDMDAAC reduced the coagulation performance of PAC, especially at an initial fluoride concentration of 1 mg/L. The fluoride removal rate decreased from 80% to 57% at B = 0.5, from 91% to 62% at B = 1.0, and from 72% to 25% at B = 2.0. The order of adding CaCl2 affects the removal rate of fluoride, with the CaCl2 + PAC sequence outperforming the reverse sequence. The study highlights the importance of optimizing coagulant basicity and CaCl2 dosing order to enhance fluoride removal efficiency, providing valuable insights for water treatment processes. These findings contribute to the development of more efficient and cost-effective coagulation strategies for fluoride removal in water treatment plants.

The salvinorins represent a unique class of polyoxygenated, non-nitrogenous diterpenes that potently and selectively modulate the kappa-opioid receptor (KOR). We recently disclosed a de novo asymmetric synthesis of this scaffold that enabled the discovery of highly potent, biased analogs, including C11-alkynes designed for the CATCH (Clearing-Assisted Tissue Click Chemistry) assay. Here, we report an optimized, scalable synthetic route that substitutes a problematic 1,4-conjugate addition of a Grignard reagent with a robust organozinc protocol in DMA, and improves a samarium-mediated Reformatsky reaction via the addition of LiBr. These methodological improvements facilitated the scalable synthesis of two highly active positive-control probes and three tailored negative-control probes, including functionally silent and cross-linking deficient analogs. A screen of >300 GPCRs confirmed the exceptional KOR selectivity of the novel alkyne probe, establishing it as a promising tool poised to validate target-specific engagement in situ, an application currently under investigation.

Ammonia is an essential chemical that underpins modern agriculture and industry, but the direct conversion of dinitrogen to ammonia under mild conditions remains highly challenging. To this end, molybdenum nitride complexes bearing 1,3-bis(di-tert-butylphosphinomethyl)benzimidazole-2-ylidene pincer ligands have been shown to catalyse ammonia formation from dinitrogen using samarium diiodide and water. However, the catalytic mechanism remains poorly understood owing to limited information on the key intermediates and the solution-state speciation of the samarium reductant. Here we show a full catalytic mechanism by combining mechanistic experiments and theoretical analyses. We isolate molybdenum methylimide and molybdenum methylamide complexes as stable analogues of catalytic intermediates, providing direct experimental evidence for the proposed catalytic pathway. Theoretical studies further suggest a plausible structure of the tetrahydrofuran-solvated samarium diiodide-water complex, and subsequent mechanistic analyses reveal that ammonia formation proceeds through proton-coupled electron transfer. Building on these experimental and theoretical findings, we identify the molybdenum-imide formation reaction as the most energy-demanding step. These findings provide a framework for understanding catalytic ammonia formation and inform future efforts to improve dinitrogen reduction catalysts.