Elegant approach to spacer arranged silagermylene and bis(germylene) compounds

Herein we report on the reactions of the stable LSiCl (1) and LGeCl (2) [L = PhC(NtBu)(2)] with L(1)Ge, [L(1) = CH{(C[double bond, length as m-dash]CH(2))(CMe)(2,6-iPr(2)C(6)H(3)N)(2)}] (3) to yield 1-sila-5-germylene (4) and a 1,5-bis(germylene) (5). The reactions proceed through the 1,4 nucleophilic addition of the M-Cl (M = Si or Ge) to 3 without any modification of the oxidation state although the change of the oxidation state is thermodynamically more favorable. Compounds 4 and 5 were investigated by single crystal X-ray structural analyses, multi-nuclear NMR spectroscopy, and micro-analysis. Treatment of L(1)AlMe·thf (6) with 1 resulted in the formation of the 1-sila-5-aluminium complex (7). The complex contains a Si(II) and an Al(III) atom in the molecule. All reported reactions proceed without changing the oxidation states at the metal centers.     

Synthesis of Tetrasubstituted Alkenes through a Palladium‐Catalyzed Domino Carbopalladation/C?H‐Activation Reaction

Helical tetrasubstituted alkenes ( 7 ) were obtained in a highly efficient way through a palladium‐catalyzed domino‐carbopalladation/CH‐activation reaction of propargylic alcohols 6 in good to excellent yields. Electron‐withdrawing‐ and electron‐donating substituents can be introduced onto the upper and lower aromatic rings. The substrates ( 6 ) for the domino process were synthesized by addition of the lithiated alkyne ( 20 ) to various aldehydes ( 19 ); moreover, the substrates were accessible enantioselectively (in 95 % ee) by reduction of the corresponding ketone using the Noyori procedure.     

Investigating the hydration of deflocculated calcium aluminate cement-based binder with catalyst waste

The hydration of the binder, consisting of calcium aluminate cement (CAC) with Al₂O₃ >70% and with or without the additives of the FCC catalyst waste and polycarboxylate deflocculant Castament FS-20, is investigated. The methods of calorimetry, thermal analysis, XRD, electrical conductivity, SEM, as well as ultrasonic wave velocity measuring and bending strength evaluation are used. The results of the investigation show that the FCC catalyst as well as polycarboxylate deflocculant, are active additives, influencing the CAC binder??s hydration process. In the structure of the hardened binders, certain amounts of unhydrated CAC minerals, CA, and CA₂, and the hydration products, such as CAH₁₀, C₂AH₈ and the amorphous AH₃, are found. However, in the binder with a deflocculant, there are smaller amounts of CAH₁₀ and the amorphous AH₃, though the amount of C₂AH₈ is higher than that in the binder without a deflocculant additive. It has been found that in the case, when the FCC catalyst and deflocculant are simultaneously used, the FCC catalyst produces a positive effect on the formation of the CAC binder??s structure, increasing its mechanical strength. The results obtained in this article allow to predict that the FCC catalyst and deflocculant simultaneously used as the additives to the CAC binder, will enable to control the hydration process of the binder.     

Highly efficient asymmetric aldol reaction in brine using a fluorous sulfonamide organocatalyst

A fluorous organocatalyst promotes direct asymmetric aldol reactions of aromatic aldehydes with ketones in brine to afford the corresponding anti-aldol products in high yield with up to 96% ee. Fluorous organocatalyst can be readily recovered by solid phase extraction using fluorous silica gel and reused without purification.     

Valence-to-core X-ray emission spectroscopy of Ti,TiO, and TiO2 by means of a double full-cylinder crystal von Hamos spectrometer

We present valence-to-core X-ray emission spectroscopy of Ti, TiO, and TiO₂ by means of a double crystal von Hamos spectrometer based on full-cylinder highly annealed pyrolytic graphite mosaic crystals. We demonstrate that, using a double crystal configuration, an energy resolution of E/ΔE ≈ 2,700 can be achieved in a compact setup using cylindrically curved optics with a radius of curvature of 50 mm. The stated energy resolution proved to be high enough to identify and determine chemical shifts of the Kβ_2,5 and Kβ″ emission lines of both oxides. The experimental results are supported by calculations with the ab initio package OCEAN and compared with literature values.     

Functionalization of silica particles towards cationic polyelectrolytes using vinylformamide and 1,3‐divinylimidazolidin‐2‐one as monomers

The use of vinylformamide and 1,3‐divinylimidazolidin‐2‐one, bisvinylethylene‐urea (BVU), as well as of the poly(vinylformamide‐vinylamine) copolymer (PVFA‐co‐PVAm) for silica surface functionalization has been investigated. Various procedures such as grafting from, crosslinking surface polymerization, and post‐functionalization of adsorbed PVAm chains have been experimentally applied. The advantage of the different synthetic methods is discussed with regard to the resulting surface structure of the organic/inorganic hybrid materials.     

Functional and pathologic association of aminoacyl-tRNA synthetases with cancer

Although key tumorigenic and tumor-suppressive factors have been unveiled over the last several decades, cancer remains the most life-threatening disease. Multiomic analyses of patient samples and an in-depth understanding of tumorigenic processes have rapidly revealed unexpected pathologic associations of new cellular factors previously overlooked in cancer biology. In this regard, the newly discovered activities of human aminoacyl-tRNA synthases (ARSs) deserve attention not only for their pathological significance in tumorigenesis but also regarding diagnostic and therapeutic implications. ARSs are not only essential enzymes covalently linking substrate amino acids to cognate tRNAs for protein synthesis but also function as regulators of cellular processes by sensing different cellular conditions. With their catalytic role in protein synthesis and their regulatory role in homeostasis, functional alterations or dysregulation of ARSs might be pathologically associated with tumorigenesis. This review focuses on the potential implications of ARS genes and proteins in different aspects of cancer based on various bioinformatic analyses and experimental data. We also review their diverse activities involving extracellular secretion, protein–protein interactions, and amino acid sensing, which are related to cancers. The newly discovered cancer-related activities of ARSs are expected to provide new opportunities for detecting, preventing and curing cancers.Subject terms: Mechanisms of disease, Nutrient signalling, Phosphorylation, Cancer metabolism, Cancer genomics