Structural Study of Alkaline‐Earth Metal Heterocycles Supported by Triazole‐based Sulfur Ligands

The alkaline earth metal complex [Mg{4,5‐(P(S)Ph₂)₂}₂tz}₂(thf)₄] ( 2 ) and the bimetallic complexes, [M{4,5‐(P(S)Ph₂)₂}₂tz}₂(thf)]₂ [M = Ca ( 3 ), Sr ( 4 ), Ba ( 5 )], [SrI{4,5‐(P(S)Ph₂)₂tz}₂(thf)₃]₂ ( 6 ), and [{BaI(4,5‐(P(S)Ph₂)₂tz)}₂(thf)₇] ( 7 ) were prepared in good yields from the metathesis reactions of the potassium salt of 4,5‐bis(diphenylthiophosphoranyl)‐1,2,3‐triazole [H{4,5‐(P(S)Ph₂)₂tz}] ( 1 ) and MI₂ (M = Ca, Sr, Ba), whereas the tetrametallic magnesium hydroxide [Mg₂(μ‐OH){4,5‐(P(S)Ph₂)₂}₂tz}₃]₂ ( 8 ) was obtained as the hydrolysis product from the starting material (MgnBuCl) and 1 . The NMR study of 2 – 8 in solution suggests the formation of solvated species in CD₃OD‐d4, whereas for 4 , 5 , and 6 a fluxional behavior is observed in CD₂Cl₂. The structural analyses of 3 – 5 , 6 , and 7 in solid state reveal in all cases a central core defined by M₂N₄ heterocycle bearing M–S bonding. The degree of aggregation observed for these compounds depends significantly on the size of the metal atom as well as on the metal‐ligand molar ratio employed for each reaction.     

Electrochemical determination of Ag-ions in environment waters and their action on plant embryos

We utilized liquid chromatography coupled with electrochemical detector (HPLC-ED) for analyzing of silver ions. The optimization of basic chromatographic parameters has been done. The detection limit (3 S/N) obtained were 20 nmol/dm(3). Influence of different interferences (anions and cations) on current response of silver ions has been described. Moreover, we used HPLC-ED to analyze waters of different purity including photographic emulsion, which naturally contained silver ions. We found out that content of silver ions in the emulsion was 1.57 x 0.03 mmol/dm(3). Moreover, we investigated influence of silver ions on early somatic embryos of Blue Spruce. We were interested in the issue how much silver ions can embryos uptake during four days long treatment. For this purpose, we used optimized HPLC-ED technique. The content increased with increasing treatment time and applied concentration. We also studied how silver ions can influence thiols content in the treated embryos. For these purposes we used adsorptive transfer stripping voltammetry in connection with differential pulse voltammetry--Brdicka reaction. It clearly follows from the obtained results that content of thiols increased with increasing treatment time and applied concentration.     

Internalization of Ineffective Platinum Complex in Nanocapsules Renders It Cytotoxic

Anticancer therapy by platinum complexes, based on nanocarrier‐based delivery, may offer a new approach to improve the efficacy and tolerability of the platinum family of anticancer drugs. The original rules for the design of new anticancer platinum drugs were affected by the fact that, although cisplatin (cis‐[PtCl₂(NH₃)₂) was an anticancer drug, its isomer transplatin was not cytotoxic. For the first time, it is demonstrated that simple encapsulation of an inactive platinum compound in phospholipid bilayers transforms it into an efficient cytotoxic agent. Notably, the encapsulation of transplatin makes it possible to overcome the resistance mechanisms operating in cancer cells treated with cisplatin and prevents inactivation of transplatin in the extracellular environment. It is also shown that transplatin delivered to the cells in nanocapsules, in contrast to free (nonencapsulated) complex, forms cytotoxic cross‐links on DNA.     

Use of green fluorescent proteins for in vitro biosensing

Due to the considerable stability of green fluorescent proteins and their capacity to be readily permutated or mutated, they may be exploited in multiple ways to enhance the functionality of in vitro biosensors. Many possibilities, such as the formation of chimeras with other proteins or antibodies, as well as Förster resonance emission transfer performance, may be used for the highly sensitive and specific detection of the target molecules. This review considers the great potential of green fluorescent proteins as the fluorescent probing or recognition biomolecule in various in vitro biosensors applications, as well as obstacles associated with their use.     

Preparation and biodistribution of <Superscript>59</Superscript>Fe-radiolabelled iron oxide nanoparticles

We report on the ⁵⁹Fe radiolabelling of iron oxide nanoparticle cores through post-synthetic isotope exchange (⁵⁹Fe-IONP_ex) and precursor labelling (⁵⁹Fe-IONP_pre). Scanning electron microscopy and dynamic light scattering measurements showed no impact of radiolabelling on nanoparticle size or morphology. While incorporation efficiencies of these methods are comparable—83 and 90% for precursor labelling and post-synthetic isotope exchange, respectively—⁵⁹Fe-IONP_pre exhibited much higher radiochemical stability in citrated human plasma. Quantitative ex vivo biodistribution study of ⁵⁹Fe-IONP_pre coated with triethylene glycol was performed in Wistar rats. Following the intravenous administration, high ⁵⁹Fe concentration was observed in the lung and the organs of the reticuloendothelial system such as the liver, the spleen and the femur.     

Influence of a controlled oxidation at moderate temperatures on the surface chemistry of nitinol wire

Commercial nitinol wire is oxidised at 480-530 °C/10 min in air. Surface morphology and chemistry is studied in detail using scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, Raman spectrometry and X-ray photoelectron spectroscopy. It is found that the main oxidation product at both temperatures is rutile containing a few at.% Ni. Beneath the rutile layer, there are titanium sub-oxides, showing characteristic maxima in depth profiles. Nickel in an oxidised state is present on the surface, whereas in a sub-surface region of scales, there is only metallic nickel. Thickness of the total oxide layers is 70 and 140 nm after oxidation at 480 and 530 °C, respectively. The preferential oxidation of titanium causes the formation of a Ni-enriched and Ti-depleted zone, suggesting the presence of Ni₃Ti phase. XRD reveals that the presence of cubic B2 NiTi phase in the base alloy is not affected by oxidation at 480-530 °C/10 min.