Reactivity of a N-Coordinated Germylene-Borane Complex: From Ge→B to Ge→Ga Coordination

Reactivity studies of the Ge^II→B complex L(Cl)Ge⋅BH₃ ( 1 ; L=2-Et₂NCH₂-4,6-tBu₂-C₆H₂) were performed to determine the effect on the Ge^II→B donation. N-coordinated compounds L(OtBu)Ge⋅BH₃ ( 2 ) and [LGe⋅BH₃]₂ ( 3 ) were prepared. The possible tuning of the Ge^II→B interaction was proved experimentally, yielding compounds 1-PPh₂-8-(LGe)-C₁₀H₆ ( 4 ) and L(Cl)Ge⋅GaCl₃ ( 5 ) without a Ge^II→B interaction. In 5 , an unprecedented Ge^II→Ga coordination was revealed. The experimental results were complemented by a theoretical study focusing on the bonding in 1 − 5 . The different strength of the Ge^II→E (E=B, Ga) donation was evaluated by using energy decomposition analysis. The basicity of different L(X)Ge groups through proton affinity is also assessed.     

Evaluation of education scenarios for acquiring digital competences of secondary school students in Slovenia

Central European Journal of Operations Research - Digital competences are among the most important competences in modern society, with the education system playing a key role in the acquisition of...     

Dissipative and generative fractional electric elements in modeling $${\varvec{RC}}$$ RC and $${\varvec{RL}}$$ RL circuits

Nonlinear Dynamics - Two types of constitutive equations consisting of instantaneous and power type hereditary contributions are proposed in order to model generalized capacitor (inductor). The...     

A characterization of sets in ℝ2 with DC distance function

Czechoslovak Mathematical Journal - We give a complete characterization of closed sets F ? ?2 whose distance function dF:= dist(·, F) is DC (i.e., is the difference of two convex...     

Modelling,performance improvement and emission reduction of large two-stroke diesel engine using multi-zone combustion model

Journal of Thermal Analysis and Calorimetry - The main energy source in marine industry is fossil fuel. Diesel engines are main power supply in sea transport at present times and will also be in...     

Thermodynamic model and Raman spectra of MgO–P2O5 glasses

Journal of Thermal Analysis and Calorimetry - The structure of binary glasses xMgO·(1?x)P2O5 (x?=?0.30, 0.35, 0.40, 0.45, 0.50, and 0.55) was studied by thermodynamic model...     

Cytotoxic dimeric half-sandwich Ru(II), Os(II) and Ir(III) complexes containing the 4,4′-biphenyl-based bridging ligands

A series of dinuclear half-sandwich Ru(II), Os(II) and Ir(III) complexes [Ru₂(μ-Lⁿ)(η⁶-pcym)₂Cl₂](PF₆)₂ ( 1 , 4 ), [Os₂(μ-Lⁿ)(η⁶-pcym)₂Cl₂](PF₆)₂ ( 2 , 5 ) and [Ir₂(μ-Lⁿ)(η⁵-Cp*)₂Cl₂](PF₆)₂ ( 3 , 6 ), based on 4,4′-biphenyl-based bridging Schiff base ligands N,N′-(biphenyl-4,4′-diyldimethylidyne)bis-2-(pyridin-2-yl)methanamine (L¹; for 1 – 3 ) and N,N′-(biphenyl-4,4′-diyldimethylidyne)bis-2-(pyridin-2-yl)ethanamine (L²; for 4 – 6 ) is reported; pcym = 1-methyl-4-(propan-2-yl)benzene, Cp* = pentamethylcyclopentadienyl. The complexes were characterized by relevant analytical techniques (i.e. elemental analysis, FT-IR, NMR, ESI-MS), and their in vitro cytotoxicity was assessed at six cancerous and two non-cancerous (healthy) human cell lines. Overall, complexes 4 – 6 , containing the L² bridging ligand, revealed higher cytotoxicity as compared with 1 – 3 and, thus, they were studied in greater detail. The best-performing complex 6 exceeded at least twice the in vitro cytotoxicity of cisplatin and showed high selectivity towards the cancer cells over the normal ones, including the primary culture of human hepatocytes. In contrast to cisplatin, complexes 4 – 6 did not induce the cell cycle modification of the treated A2780 human ovarian carcinoma cells (studied by flow cytometry and Western blot analysis). High levels of superoxide anion were induced by complexes 4 – 6 at the A2780 cells. The levels of activated forms of Caspase-3 and Caspase-8 at the A2780 cells treated by Ru(II) complex 4 were comparable with cisplatin, while complexes 5 and 6 had only a minor effect on activation of these caspases.     

Capillary electrophoresis and ultra-high-performance liquid chromatography methods in clinical monitoring of creatinine in human urine: A comparative study

Creatinine is an important diagnostic marker and is also used as a standardization tool for the quantitative evaluation of exogenous/endogenous substances in urine. This study aimed at evaluating and comparing three analytical approaches, based on hyphenations of different separation [two-dimensional capillary isotachophoresis (CITP–CITP), capillary zone electrophoresis (CZE), ultra-high-performance liquid chromatography (UHPLC)] and detection [conductivity (CD), ultraviolet (UV), tandem mass spectrometry (MS/MS)] techniques, for their ability to provide reliable clinical data along with their suitability for the routine clinical use (cost, simplicity, sample throughput). The developed UHPLC–MS/MS, CITP–CITP–CD, and CZE–UV methods were characterized by favorable performance parameters, such as linearity (r ˃ 0.99), precision (relative standard deviation, 0.22–2.97% for the creatinine position in analytical profiles), and recovery (87.1–115.1%). Clinical data, obtained from the analysis of 24 human urine samples by a reference enzymatic method, were comparable with those obtained by the tested methods (Passing–Bablok regression and Bland–Altman analysis), approving their usefulness for the routine clinical use. In this context, the UHPLC–MS/MS method provides benefits of enhanced orthogonality/accuracy and high sample throughput (threefold shorter total analysis times than the CE methods), whereas advantages of the CE methods for routine labs are simplicity and low cost of both the instrumentation and measurements.