Note of Caution for the Aqueous Behaviour of Metal-Based Drug Candidates

Poor aqueous solubility is one of the recurrent drawbacks of many compounds in medicinal chemistry. To overcome this limitation, the dilution of drug candidates from stock solutions of an organic solvent is common practice. However, the precise characterisation of these compounds in aqueous solutions is often neglected, leading to some uncertainties regarding the nature of the actual active species. In this communication, we demonstrate that two ruthenium complexes previously reported by our group for their chemotherapeutic potential against cancer, namely [Ru(DIP)₂(sq)](PF₆) and [Ru(DIP)₂(3-methoxysq)](PF₆), where DIP is 4,7-diphenyl-1,10-phenanthroline, sq=semiquinonate and 3-methoxysq=3-methoxysemiquinonate, form colloids in water-DMSO (1 % v/v) mixtures that are invisible to the naked eyes. [Ru(DIP)₂(3-methoxysq)](PF₆) was found to form a highly stable and monodispersed colloid with nanoaggregates of ∼25 nm. In contrast, [Ru(DIP)₂(sq)](PF₆) was found to form large reticulates of mostly spherical aggregates which size was found to increase over time. The difference in size and shape distribution of drug candidates is of tremendous significance as the study of their biological activity might be severely affected. Overall, we strongly believe that these observations should be taken into account by the scientific community working on the development of metal-based drugs with poor water solubility.     

Effect of hydrometallurgical process parameters on the Mn2O3 nano catalysts derived from spent batteries used in the plasma catalytic oxidation of BTX

Manganese oxide catalysts have been synthesized from the used batteries via hydrometallurgical method and effect of hydrometallurgical parameters such as the effect of acid type (H₂SO₄, HNO₃, HCl), acid concentration (0.5, 1, 1.5, 2 %v/v) and powder to acid ratio (1/50, 1/60, 1/70, 1/80) were in detail investigated. The physico-chemical properties of as-prepared catalysts were characterized by FT-IR, XRD, FESEM, EDX, BET, TEM, and TPR-H₂ analysis. The activity of as-prepared catalysts were investigated towards the oxidation of benzene, toluene, and xylene (BTX) in a plasma-catalytic process. The results show that benzene and toluene conversion were almost constant in the range of 97–98% in case of various acid types, acid concentrations and solid to liquid ratios. However, the xylene conversion were varied in case of different hydrometallurgical factors. The highest xylene conversion was obtained in the presence of MnS0.5–60, which was prepared using H₂SO₄ with concentration of 0.5%v/v and solid to liquid ratio of 1/60. The effect of the input voltage and BTX flow rate on the BTX conversion was also investigated using MnS0.5–60 catalyst in detail.     

Additive manufacturing of bipolar plates for hydrogen production in proton exchange membrane water electrolysis cells

Water electrolysis is a process that can produce hydrogen in a clean way when renewable energy sources are used. This allows managing large renewable surpluses and transferring this energy to other sectors, such as industry or transport. Among the electrolytic technologies to produce hydrogen, proton exchange membrane (PEM) electrolysis is a promising alternative. One of the main components of PEM electrolysis cells are the bipolar plates, which are machined with a series of flow distribution channels, largely responsible for their performance and durability. In this work, AISI 316L stainless steel bipolar plates have been built by additive manufacturing (AM), using laser powder bed fusion (PBF-L) technology. These bipolar plates were subjected to ex-situ corrosion tests and assembled in an electrolysis cell to evaluate the polarization curve. Furthermore, the obtained results were compared with bipolar plates manufactured by conventional machining processes (MEC). The obtained experimental results are very similar for both manufacturing methods. This demonstrates the viability of the PBF-L technology to produce metal bipolar plates for PEM electrolyzers and opens the possibilities to design new and more complex flow distribution channels and to test these designs in initial phases before scaling them to larger surfaces.     

水提法提取—电感耦合等离子体质谱法测定婴幼儿配方奶粉中的碘

用水提取婴幼儿奶粉中的碘,亚铁氰化钾和乙酸锌盐析法沉淀蛋白,过滤后可以得到澄清处理液。用电感耦合等离子体质谱对提取样液进行测定,130Te作为内标物进行定量分析。该方法简便快捷,检出限为0.10 mg/kg加标回收率为90.8%~109%,相关系数0.999,精密度试验RSD2%。     

Carbon supported bimetallic Ru‐Co catalysts for H2 production through NaBH4 and NH3BH3 hydrolysis

This work investigates the effect of the addition of small amounts of Ru (0.5‐1 wt%) to carbon supported Co (10 wt%) catalysts towards both NaBH₄ and NH₃BH₃ hydrolysis for H₂ production. In the sodium borohydride hydrolysis, the activity of Ru‐Co/carbon catalysts was sensibly higher than the sum of the activities of corresponding monometallic samples, whereas for the ammonia borane hydrolysis, the positive effect of Ru‐Co systems with regard to catalytic activity was less evident. The performances of Ru‐Co bimetallic catalysts correlated with the occurrence of an interaction between Ru and Co species resulting in the formation of smaller ruthenium and cobalt oxide particles with a more homogeneous dispersion on the carbon support. It was proposed that Ru^°, formed during the reduction step of the Ru‐Co catalysts, favors the H₂ activation, thus enhancing the reduction degree of the cobalt precursor and the number of Co nucleation centers. A subsequent reduction of cobalt and ruthenium species also occurs in the hydride reaction medium, and therefore the state of the catalyst before the catalytic experiment determines the state of the active phase formed in situ. The different relative reactivity of the Ru and Co active species towards the two investigated reactions accounted for the different behavior towards NaBH₄ and NH₃BH₃ hydrolysis.     

提高焊膏印刷质量的工艺改进

焊膏印刷作为SMT工艺的第一步，其质量好坏对SMT工艺有着重要影响。文章通过对焊膏成分、特性的分析，讨论了印刷中各种工艺参数的正确选择；对焊膏印刷中容易出现的质量问题进行了详细分析，指出了产生问题的原因，提出了改进措施。     

纳米级BaAl_2O_4微粉的制备和性质

分别用溶胶 -凝胶法、低温固相反应法 ,制得了纳米级BaAl2 O4微粉 ,用电镜观察了其形貌和粒径的大小 ,用X-射线衍射仪进行了物相分析 ,测定了其纯度与晶型 ,讨论了制备方法与粒度大小的相互影响     

利用废旧塑料生产阻燃建筑装饰材料探讨

本文介绍了一种综合利用废旧热塑性塑料和锯末粉通过加入阻燃剂改性 ,生产防火阻燃型建筑装饰材料的方法。所生产的产品 ,其阻燃性能均达到国家标准 (GB5464 - 85)中规定的不燃性材料的要求。