New heteroleptic lanthanide complexes as multimodal drugs: Cytotoxicity studies,apoptosis, cell cycle analysis,DNA interactions,and protein binding

We report herein the synthesis and characterization of four new heteroleptic complexes of Sm(III), Eu(III), Gd(III), and Tb(III) with the natural flavonoid 5‐hydroxyflavone (primuletin) and 1,10‐phenanthroline. According to the physicochemical characterization, the mononuclear complexes correspond to the general formula [Ln(OH) ₂ L ₁ L ₂ ]·nH ₂ O , where L₁ = C₁₅H₉O₃ (deprotonated 5‐hydroxyflavone) and L₂ = C₁₂H₈N₂ (1,10‐phenanthroline), Ln is the lanthanide cation, and n = 4 for Sm(III), 3.5 for Eu(III), 2 for Gd(III), and 3 for Tb(III). A six‐coordinated distorted octahedron geometry was proposed for the complexes, and density functional theory (DFT) studies were used to calculate their optimized geometry. Cytotoxicity was studied using MTS assay on cervical, colorectal, colon, breast, and ovarian adenocarcinoma cell lines. Flow cytometry data were consistent with apoptotic cell death and disruption of the cell cycle in cervical and colon cancer cells. As a means to investigate the mechanism underlying the cytotoxic effects, the abilities of the complexes to interact with calf thymus DNA, human serum albumin, and transferrin have also been assessed. According to experimental and computational studies, the four lanthanide complexes act as DNA intercalators and bind strongly to serum proteins.     

On the determination of 36Cl and 129I in solid materials from nuclear decommissioning activities

Journal of Radioanalytical and Nuclear Chemistry - Determination of the 36Cl and 129I massic activities using pyrolysis combined with radiochemical separation (using a Cl-resin) in concrete and...     

Dansylated acrylic copolymer with potential for sensor applications: Synthesis and properties

A novel copolymer has been prepared by free radical polymerization in dimethylformamide of 5‐dimethylamino‐1‐(β‐methacryloyloxyethylcarbamoyloxyethyl)‐N‐methylsulfonamido‐naphthalene (Dns‐Acr) and methyl methacrylate in 1:3 M ratio with azobis(isobutyronitrile) as the initiator. The structure, purity, and the chemical composition of the dansylated copolymer (Dns‐COPA) were confirmed by spectrophotometric (¹HNMR, FTIR, UV/vis), thermal and analytical methods, GPC measurements, and AFM techniques. Compared with Dns‐Acr, whose fluorescence emission band appears at 510 and 430 nm (shoulder), the photoluminescence spectrum of the Dns‐COPA in DMF solution exhibited a strong fluorescence emission at 440 nm (I₁), and a small shoulder at 520 nm (I₂) accompanying the main signal. The emitting behavior of Dns‐COPA was investigated through a spectrofluorimetric titration experiment, the fluorescence measurements demonstrating that introduction of various acids into the solution has a significant effect upon the quenching of fluorescence. This ability of dansyl copolymer to suffer the protonation of the amino group in organic acidic phase may be exploited in sensor applications. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3774–3782, 2008     

Grid Vertex-Unfolding Orthogonal Polyhedra

An edge-unfolding of a polyhedron is produced by cutting along edges and flattening the faces to a net, a connected planar piece with no overlaps. A grid unfolding allows additional cuts along grid edges induced by coordinate planes passing through every vertex. A vertex-unfolding allows faces in the net to be connected at single vertices, not necessarily along edges. We show that any orthogonal polyhedra of genus zero has a grid vertex-unfolding. (There are orthogonal polyhedra that cannot be vertex-unfolded, so some type of “gridding” of the faces is necessary.) For any orthogonal polyhedron P with n vertices, we describe an algorithm that vertex-unfolds P in O(n ²) time. Enroute to explaining this algorithm, we present a simpler vertex-unfolding algorithm that requires a 3×1×1 refinement of the vertex grid. This is a significant revision of the preliminary version that appeared in [2]. J. O’Rourke’s research was supported by NSF award DUE-0123154.     

Biodegradation behaviour of poly(lactic acid) and (lactic acid-ethylene glycol-malonic or succinic acid) copolymers under controlled composting conditions in a laboratory test system

(Lactic acid, ethylene glycol, malonic or succinic acid) copolymers [(LA-EG-MA) and (LA-EG-SA) copolymers] were synthesized with different monomer feed ratios by direct polycondensation. The copolymers were characterized in terms of various properties such as acid value and number average molecular weight. The aerobic biodegradation under controlled composting conditions of commercially available and laboratory synthesized poly(l-lactic acid) (PLA) and synthesized copolymers was carried out according to ISO 14855-1:2005. The biodegradability of tested materials was found to be strongly dependent on the lactic acid content, ranging from 94% (method A) and 104% (method B) to 43% (method A) and 46% (method B) over the 110-days of the 50 °C composting.     

Efficient palladium-mediated or base-induced 5-endo-dig cyclisation of C5-alkynylated pyrimidine derivatives: conventional and microwave-assisted synthesis of novel furo[2,3-d]pyrimidines

A series of the novel 5-alkynyl- and furo[2,3-d]pyrimidine derivatives in which the sugar moiety is replaced by a methoxymethyl (MOM) group is synthesised using the Sonogashira cross-coupling reaction under both conventional and microwave conditions, in good to excellent yields. The 5-endo-dig cyclisation of 5-alkynylpyrimidine derivatives promoted by a Pd-catalyst or base gives the corresponding furo[2,3-d]pyrimidines in good yields.     

Synthesis and Characterization of Nanostructured a-C:H (Hydrogenated Amorphous Carbon) Thin Films by Gaseous Thermionic Vacuum Arc (G-TVA) Deposition Technique

The aim of this contribution is to present the properties of the nanostructured hydrogenated carbon thin films and to study their growth carried out in a special deposition technique based on Thermionic Vacuum Arc method. The Gaseous Thermionic Vacuum Arc (G-TVA) technology is an original deposition method performed in a special configuration, consisting of a heated thermionic cathode which provides an electron beam on the anode. The surface free energy was evaluated by contact angle and their optical properties were studied by Filmetrics F20 spectrometry system. Structure of the film has been investigated by Raman spectroscopy as well as the mechanical properties like hardness, wear resistance, film-substrate adhesion. The films showed two distinct Raman characteristic peaks located at 1,350 cm⁻¹ (D-line) and 1,550 cm⁻¹ (G-line), broad for Si and very sharp for glass substrates. The G-TVA enables to prepare soft (hardness ~6 GPa) or hard (~24 GPa) films.     

Silica matrices for embedding of magnetic nanoparticles

This paper presents a study regarding the formation of hybrid gels starting from tetraethyl orthosilicate (TEOS), polyvinyl alcohol (PVA) and 1,3-propanediol (PD) and their thermal evolution to mesoporous silica matrices. The possibility of obtaining homogenously dispersed cobalt ferrite inside the silica matrix starting from (TEOS–PVA–PD–Metal Nitrates) gels was also studied. The formation of the hybrid gels TEOS/PVA/PD with different compositions was studied by FT-IR spectrometry and thermal analysis, in order to evidence the interaction between the diol with the organic and the inorganic polymers. Both thermal analysis and FT-IR spectrometry have evidenced the formation of physical and chemical interaction between polyols and the siloxane network. Elemental mapping performed by SEM-EDX technique evidenced the formation of homogenous hybrids both in the presence of the absence of 1,3-propanediol. SEM images of the powders obtained by annealing the hybrid xerogels at 600 °C have evidenced the formation of mesoporous silica. By thermal treatment of the (TEOS–PVA–PD–Metal Nitrates) gels, 30%CoFe₂O₄/70%SiO₂ (mass percent) nanocomposites uniformly dispersed in silica matrix with characteristic magnetic properties, have been successfully synthesized.     

Controlled Positioning of Activated Ester Moieties on Well‐Defined Linear Polymer Chains

The successful sequence‐controlled installation of an activated ester using a newly designed monomer pentafluorophenyl 4‐maleimidobenzoate is demonstrated. Pentafluorophenyl 4‐maleimidobenzoate is kinetically installed at different stages of a nitroxide‐mediated polymerization, namely, near the α‐chain end and in the middle of a PS chain. In addition, successful installation of apolar and polar functional groups is achieved via post‐polymerization functionalization, which demonstrated the versatility of the synthesis of a universal precursor for locally functionalized polymers.