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• A liquid-phase flocculating settling assisted carbothermal reduction method to prepare ultrafine powders of single-phase HfB 2 with low oxygen and carbon content. • Manuscript proposes a new reaction path that the HfC is not an intermediate product of HfB 2 powder at lower temperature, but by-products at high temperature in the carbothermal reduction process. • The flocculating settling method can be extended to the synthesis of other high-purity and ultrafine group IV and v transition metal (Ti, Zr, Ta, Nb) diboride powders. • The work has proved to be applicable to the mass production of kilogram grade ultrafine HfB 2 powder with high purity. In this study, ultrafine HfB 2 powders with low oxygen were synthesized by a flocculating settling process which yielded ceramic precursors and subsequent carbo/borothermal reduction of the precursors. The liquid phase precursor method can achieve uniform mixing of components at the molecular level through multiple complexation reactions, and then realize the carbo/borothermal reduction reaction at a lower temperature to obtain ultrapure HfB 2 powders. The as-resulted quasi-spherical HfB 2 powders under the optimum conditions (atomic molar ratio M:B:C = 1:2.8:10) calcined at 1500 °C for 1 h have an average particle size of 205 nm and an oxygen content of 0.097 wt.%. Detailed analysis of the phase evolution of precursors shows that the formation of HfB 2 particles is a mass diffusion mode from the external to internal HfO 2 cores. We reveal that below 1300 °C, HfC is not an intermediate product of HfB 2 powder during the transition of precursors. Instead, HfC was formed as a by-product at high temperatures in the carbo/borothermal reduction process. The proposed formation mechanism of HfB 2 is completely different from the traditional two-step transformation method. After the sintering of the ultrafine powders, the HfB 2 ceramics show a relative density of 96.1% and superior mechanical properties compared to other works. Furthermore, by simply replacing the initial metal source, chlorinated group IV and V transitional metals (Ti, Zr, Ta, Nb) can also convert into high-purity and ultrafine diborides. This work shows that flocculating settling assisted carbo/borothermal reduction has potential in lot size production of various high-purity and ultrafine boride powders. [Display omitted] [ABSTRACT FROM AUTHOR]

A recent study conducted at the University of Jeddah in Saudi Arabia explored the proton transfer complexation reaction between the drug 3,4-diaminopyridine and 2,6-dichloro-4-nitrophenol, shedding light on potential applications in cancer therapy. The research involved experimental and theoretical investigations, including the characterization of the formed complex using various spectroscopic techniques. Additionally, the study examined the DNA binding ability and cytotoxic effects of the proton transfer complex, showing promising antitumor activity against specific cancer cell lines. For more details, the full article can be accessed in the journal Molecules. [Extracted from the article]

Researchers at the University of Miyazaki in Japan have conducted a study on the development of amphiphilic short peptides to control drug inclusivity through metal complexation reactions. The researchers found that ternary complexes formed by these peptides enhanced the water dispersibility of a poorly water-soluble anticancer drug, paclitaxel (Ptx), and reduced cell viability by approximately 60%. They also synthesized two novel peptides, KHHA6W and KHHA3WA3, as dispersants for Ptx, but found that the change in amino acid residues had little effect on the water dispersibility of the drug. This research has been peer-reviewed. [Extracted from the article]

A recent study conducted by researchers at Universidad Nacional Agraria La Molina in Lima, Peru, explored the influence of essential oil:cyclodextrin ratio and stirring rate on the physicochemical characteristics of orange essential oil: b-cyclodextrin microparticles. The study found that an OEO:b-CD ratio of 0.15 (w/w) and a stirring speed of 700 rpm resulted in the highest entrapment efficiency (95.18%), oil retention (79.13%), and lowest surface oil content (10.02 mg oil/g powder microparticles). The microparticles exhibited irregular and elongated shapes, with the opacity distribution being the most influenced. The researchers also observed a complexation reaction after encapsulation. For more information, the full research article can be accessed for free at the provided link. [Extracted from the article]

The article looks at various studies concerning the presence of heavy metals in wine. Topics discussed include the accuracy of the conclusions in the studies, the relations between metal ion complexation and bioavailability, and the use of stripping potentiometry in examining the toxicity and lability of lead in wine.