Platinum(II)-thiosemicarbazone drugs override the cell resistance due to glutathione; assessment of their activity against human adenocarcinoma cells

New platinum(II) compounds of the thiosemicarbazone 1-(1H-Benzimidazol-2-yl)ethan-1-one thiosemicarbazone (BzimetTSCH), [Pt(BzimetTSCH)Cl]·2H₂O (1) and [Pt(BzimetTSCH)(tpp)]Cl·H₂O·MeCN (2) were synthesized. The complexes were characterized by FT-IR spectroscopy and ¹H NMR spectroscopy. The crystal structures of 1 and 2 were determined with single-crystal X-ray diffraction analysis. The coordination around platinum is square planar in both complexes. Compounds 1 and 2 were evaluated for their in vitro cytotoxic activity against human adenocarcinoma breast (MCF-7) and cervix (HeLa) cells. The apoptotic pathway of cell death was confirmed by cell cycle arrest test. Since deactivation of cisplatin caused by glutathione (GSH) seems to be an important determinant of its cytotoxic effects, the reactions of 1 and 2 with GSH were investigated by UV-absorption spectroscopy. The genotoxicities on normal human fetal lung fibroblast cells (MRC-5) caused by 1 and 2 were evaluated by fluorescence microscopy. The absence of micronucleus in MRC-5 cells confirms the in vitro non toxic behavior of the compounds. Moreover, the in vivo genotoxicities of 1 and 2 were evaluated by the Allium cepa test. Due to negligible genototoxic effect and high antitumor activity which is similar to that of cisplatin, 2 could be a candidate for further study as potential drug since the mitotic index is unchanged.     

Manipulating the Coffee‐Ring Effect: Interactions at Work

The evaporation of a drop of colloidal suspension pinned on a substrate usually results in a ring of particles accumulated at the periphery of the initial drop. Intense research has been devoted to understanding, suppressing and ultimately controlling this so‐called coffee‐ring effect (CRE). Although the crucial role of flow patterns in the CRE has been thoroughly investigated, the effect of interactions on this phenomenon has been largely neglected. This Concept paper reviews recent works in this field and shows that the interactions of colloids with (and at) liquid–solid and liquid–gas interfaces as well as bulk particle–particle interactions drastically affect the morphology of the deposit. General rules are established to control the CRE by tuning these interactions, and guidelines for the rational physicochemical formulation of colloidal suspensions capable of depositing particles in desirable patterns are provided. This opens perspectives for the reliable control of the CRE in real‐world formulations and creates new paradigms for flexible particle patterning at all kinds of interfaces as well for the exploitation of the CRE as a robust and inexpensive diagnostic tool.     

A highly porous interpenetrated metal-organic framework from the use of a novel nanosized organic linker

The initial use of a novel elongated tricarboxylic acid H(3)hmpib in metal-organic framework (MOF) chemistry resulted in a [Zn(4)O(hmpib)(2)] MOF (UCY-1) with pyrite topology. The compound displays a remarkably high internal surface area despite its double-interpenetrated structure as well as high CO(2) uptake and selective adsorption for it over CH(4).     

Application of the GALI method to localization dynamics in nonlinear systems

We investigate localization phenomena and stability properties of quasiperiodic oscillations in N$N$ degree of freedom Hamiltonian systems and N$N$ coupled symplectic maps. In particular, we study an example of a parametrically driven Hamiltonian lattice with only quartic coupling terms and a system of N$N$ coupled standard maps. We explore their dynamics using the Generalized Alignment Index (GALI), which constitutes a recently developed numerical method for detecting chaotic orbits in many dimensions, estimating the dimensionality of quasiperiodic tori and predicting slow diffusion in a way that is faster and more reliable than many other approaches known to date.     

Ultraviolet discharges from a radio-frequency system for potential biological/chemical applications

In this work, we describe a new electrode-less radio-frequency(RF) excitation technique for generating excimers in the vacuum ultraviolet(VUV) and ultraviolet(UV) spectral regions for potential biological/chemical applications. Spectra data of Xe~*_2, XeI~*, and KrI~* generated by this new technique are presented. Optical efficiency of the lamp system ranges from 3% to 6% for KrI~*, 7% to 13% for XeI~*, and 15% to 20% for Xe~*_2. Also, results of irradiating E-coli with XeI~*discharge from this lamp system is presented to show one of the promising applications of such electrode-less apparatus.This new RF lamp system offers an interesting addition to the already existing technologies for generating VUV and UV light for various biological, physical, and chemical processes especially those requiring large area for high productivity.     

MRI assessment of drug-induced fluid accumulation in humans: validation of the technology

PURPOSE: The purpose of this study was to evaluate the feasibility of using proton and sodium magnetic resonance imaging (MRI) to detect fluid accumulation produced by fludrocortisone and nifedipine - two drugs known to cause salt/water retention by different mechanisms. MATERIALS AND METHODS: Twelve young healthy male subjects were randomly assigned to one of two groups and treated with either fludrocortisone or nifedipine for 14 or 25 days, respectively. The change in sodium MRI, as well as in proton T(2) value and T(1)-weighted signal intensity in the calf following postural change [referred to here as 'postural delta signal'(PDS)], was evaluated before, during and after drug administration. The changes in MRI PDS were compared to conventional physiological parameters, including body weight, calf volume and pitting edema. RESULTS: When compared to the baseline pretreatment values, the subjects treated with fludrocortisone showed a 5.5% increase in sodium MRI PDS (P=.01), a 2-ms increase in proton T(2) PDS of the gastrocnemius muscle (P=.06) and a body weight gain of 2.3% (P=.001) within 1 week. In the nifedipine-treated subjects, the sodium MRI PDS increased by 6% versus baseline (P=.03), while the proton T(2) PDS of the gastrocnemius muscle increased by 3.7 ms (P=.01), associated with a 0.5% weight gain (P=.55), within 3 weeks. No significant changes were noted in the T(1)-weighed images following postural change. Measurements of calf circumference, volume and pitting edema did not show consistent changes associated with the drug administration. CONCLUSION: The postural change in sodium MRI and proton T(2) signals provides a sensitive method for detecting the fluid accumulation produced by fludrocortisone and nifedipine. The MRI results are consistent with treatment-induced increases in extracellular fluid volume and correlate well with the observed weight gain. These findings support the potential utility of MRI for the evaluation of medication-induced fluid retention.     

Adsorption and dissociation of O2 on Pt-Co and Pt-Fe alloys

Self-consistent periodic density functional theory calculations (GGA-PW91) have been performed to study the adsorption of O and O(2) and the dissociation of O(2) on the (111) facets of ordered Pt(3)Co and Pt(3)Fe alloys and on monolayer Pt skins covering these two alloys. Results are compared with those obtained on two Pt(111) surfaces, one at the equilibrium lattice constant and the other laterally compressed by 2% to match the strain in the Pt alloys. The absolute magnitudes of the binding energies of O and O(2) follow the same order in the two alloy systems: Pt skin < compressed Pt(111) < Pt(111) < Pt(3)Co(111) or Pt(3)Fe(111). The reduced activity of the compressed Pt(111) and Pt skins for oxygen can be rationalized as being due to the shifting of the d-band center increasingly away from the Fermi level. We propose that an alleviation of poisoning by O and enhanced rates for reactions involving O may be some of the reasons why Pt skins are more active for the oxygen reduction reaction in low-temperature fuel cells. Finally, a linear correlation between the transition-state and final-state energies of O(2) dissociation on monometallic and bimetallic surfaces is revealed, pointing to a simple way to screen for improved cathode catalysts.     

Extension Principles for Dual Multiwavelet Frames of $$L_2(\mathbb {R}^s)$$ constructed from Multirefinable Generators

In this work we prove that any pair of homogeneous dual multiwavelet frames of \(L_2(\mathbb {R}^s)\) constructed from a pair of refinable function vectors gives rise to a pair of nonhomogeneous dual multiwavelet frames and vice versa. We also prove that the Mixed Oblique Extension Principle characterizes dual multiwavelet frames. Our results extend recent characterizations of affine dual frames derived from scalar refinable functions obtained in [3].