Synthesis and antibody conjugation of magnetic nanoparticles with improved specific power absorption rates for alternating magnetic field cancer therapy

Bionized nanoferrite (BNF) particles with high specific power absorption rates were synthesized in the size range of 20–100 nm by high-pressure homogenization for targeted cancer therapy with alternating magnetic fields. Several strategies were used to conjugate antibodies to the BNF particles. These strategies were compared using an immunoassay to find optimal conditions to reach a high immunoreactivity of the final antibody–particle conjugate.     

Particle analysis of car exhaust by ETV-ICP-MS

Particulates of platinum group elements (Pt, Rh, Pd, Ir) emitted in automotive catalyst exhaust were measured down to the pg/m(3) level. Samples were taken from a standard type three-way catalyst equipped gasoline engine, running on a computer controlled dynamometer. Particulates in catalyzed car exhaust were sampled fractionated according to size by using the cascade impactor with separate targets mounted underneath each nozzle. The targets, small flat discs made of pure graphite, were subsequently analyzed by ETV-ICP-MS without any preparatory steps.     

Cs3[Tb10(C2)2]Cl21, ein neuer Formel- und Strukturtyp mit isolierten,dimeren Clustern

Cs₃[Tb₁₀(C₂)₂]Cl₂₁, A New Formula and Structure Type with Isolated Dimeric Clusters Cs₃[Tb₁₀(C₂)₂]Cl₂₁ is obtained via the metallothermic reduction of TbCl₃ with caesium in the presence of graphite as black single crystals. The crystal structure (monoclinic, C2/c, Z = 4; a = 2318.72(13); b = 1245.8(9); c = 1502.0(13) pm; β = 98.13(6)°; R = 0.089; R_w = 0.049) contains dimeric clusters that are built from two octahedra connected via one common edge and filled with C₂ units. These isolated [Tb₁₀(C₂)₂] clusters are surrounded by 26 chloride ligands which are then connected via i—a and a—a bridges in a way that voids for Cs⁺ of coordination number 10 are formed.     

Platinum solubility of a substance designed as a model for emissions of automobile catalytic converters

Automobile catalytic converters emit nanocrystalline platinum attached to alumina particles. For investigations about the bioavailability of Pt from these particles a model substance with approx. 5% Pt on alumina has been prepared and characterized by physical methods (ESCA, XRD, TEM, DTA, TG). Measuring the platinum solubility of these samples in different solvents revealed high amounts that can be explained assuming a corrosion process. The portion of soluble platinum is dependent on the particle size distribution. For a comparative study platinum black has been used. In general the platinum determination has been carried out by electrothermal atomic absorption spectrometry (ET-AAS). The comparison of ET-AAS results with determinations by adsorptive voltammetry (formazone method) allowed to distinguish between elemental and ionic platinum; in solution samples only ionic platinum has been present. UV spectra of extracts have been used for the semi-quantitative platinum speciation in solutions.     

Ca3N2 and Mg3N2: unpredicted high-pressure behavior of binary nitrides

High-pressure synthesis allows both fundamental and materials science research to gain unprecedented insight into the inner nature of materials properties at extreme environment conditions. Here, we report on the high-pressure synthesis and characterization of γ-Ca(3)N(2) and the high-pressure behavior of Mg(3)N(2). Investigation of M(3)N(2) (M = Ca, Mg) at high-pressure has been quite challenging due to the high reactivity of these compounds. Ex situ experiments have been performed using a multianvil press at pressures from 8 to 18 GPa (1000-1200 °C). Additional in situ experiments from 0 to 6 GPa (at RT) at the multianvil press MAX 80 (HASYLAB, Beamline F.2.1, Hamburg) have been carried out. The new cubic high-pressure phase γ-Ca(3)N(2) with anti-Th(3)P(4) defect structure exhibits a significant increase in coordination numbers compared to α-Ca(3)N(2). Contrary, Mg(3)N(2) shows decomposition starting at surprisingly low pressures, thereby acting as a precursor for Mg nanoparticle formation with bcc structure. Soft X-ray spectroscopy in conjunction with first principles DFT calculations have been used to explore the electronic structure and show that γ-Ca(3)N(2) is a semiconductor with inherent nitrogen vacancies.     

Interfacing strong electron acceptors with single wall carbon nanotubes

The complementary use of steady-state and time-resolved spectroscopy in combination with electrochemistry and microscopy are indicative of mutual interactions between semiconducting SWNTs and a water-soluble strong electron acceptor, i.e., perylenediimide. Significant is the stability and the strong electronic coupling of the perylenediimide/SWNT electron donor-acceptor hybrids. Several spectroscopic and spectroelectrochemical techniques, i.e., Raman, absorption, and fluorescence, confirmed that distinct ground- and excited-state interactions occur and that kinetically and spectroscopically well characterized radical ion pair states form within a few picoseconds.     

Characterization of the Composition of Solid Mixtures Using Particle Shape Distributions Obtained by Image Analysis

There are many applications of particle technology in which solid mixtures consisting of particles having the same chemical, mineralogical and physical properties are used. The particles are then distinguishable only by shape. The particle shape significantly influences the technological behaviour of the mixture and the properties of the materials produced. Therefore, mathematical procedures are necessary in order to determine the composition of such a mixture according to the proportions of certain particle shape classes. These classes are the respective components of the mixture. In this work, various statistical methods were tested to classify the particles by shape analysis. A two-component mixture of quartz and muscovite was used as a reference material. The results obtained by different theoretical methods were compared with each other. Alternative methods such as histogram fit and the EM algorithm provided better results than the conventional method of discriminant analysis, as expected. Because the statistical behaviour of the components can be estimated only using reference samples, a statistical error of about 5–10% depending on the respective sample size was met. However, this is a satisfactory result. It turned out that it is possible to conclude exclusively on the basis of the particle shape distribution about the composition of a mixture. The methodical knowledge obtained can be used in industrial applications such as the ceramic industry, the production of paints and the bulk solids technology.     

Structural investigation of five N-arylsulfonyloxazolidines

The crystal structures of (1R,5R,8S)-8-[(2R,4R)-4-ethyl-3-(2,4,6- trimethyl-benzenesulfonyl)-oxazolidin-2-yl]-1-hydroxy-bicyclo[3.3.1]nonan-3-one (1), formic acid (1S,2R)-2-{2-[(2R,4R)-4-ethyl-3-(toluene-4-sulfonyl)-oxazolidin-2-yl]-cyclohexylidene}-1-trimethylsilanyl-ethyl ester (2), (2R,4R)-2-{(4S,5R,6S)-6-tertbutyl-2,2,4,5-tetramethyl-[1,3]dioxan-4-yl}-4-ethyl-3-(toluene-4-sulfonyl)-oxazolidine (3), (2S)-2-[(2R,4R,5R)-4-methyl-5-phenyl-3-(toluene-4-sulfonyl)-oxazolidin-2-yl]-3,4-dihydro-2H-naphthalen-1-one (4) and (1R)-1-[(2R,4R,5R)-4-methyl-5-phenyl-3-(toluene-4-sulfonyl)-oxazolidin-2-yl]-3,4-dihydro-1H-naphthalen-2-one (5) have been determined: (1) crystallizes in the orthorhombic space group P2₁2₁2₁ with cell dimensions a = 11.120(1), b = 13.809(1), c = 14.676(1) Å, (2) crystallizes in the monoclinic space group P2₁ with cell dimensions a = 12.577(3), b = 9.589(1), c = 13.971(3) Å, = 95.77(1) °, (3) crystallizes in the monoclinic space group P2₁ with cell dimensions a = 7.990(4), b = 11.282(9), c = 14.473(4) Å, = 96.31(3)°, (4) crystallizes in the orthorhombic space group P2₁2₁2₁ with cell dimensions a = 7.674(1), b = 14.647(1), c = 20.620(1) Å, (5) crystallizes in the monoclinic space group P2₁ with cell dimensions a = 7.890(2), b = 11.319(1), c = 13.493(3) Å, = 104.12(1)°.     

Discovering novel targets for autoantibodies in dilated cardiomyopathy

There is increasing evidence that a large proportion of dilated cardiomyopathy (DCM) cases are mediated by autoimmune processes. Since DCM is a fatal disorder with rapid aggravation and is the leading cause of heart transplantation, further insights into disease pathogenesis are needed. Recent studies have separated the pathogenic capacity of autoantibodies and initial clinical trials removing such autoantibodies via immunoadsorption have been promising. In order to elucidate the full autoantibody repertoire involved in DCM, we applied an autoantibody screening test using ventricular and atrial proteomes as autoantigenic sources and subsequently tested the autoantibody-binding patterns of sera from dogs with spontaneous DCM. With this method, we detected five potentially DCM-related autoantigens which were identified by MS as being: myosin heavy chain cardiac muscle alpha isoform, alpha cardiac actin, mitochondrial aconitate hydratase, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and brain glycogen phosphorylase (GPBB). The recovery of two known DCM autoantigens (myosin heavy chain and alpha cardiac actin) and the discovery of three novel autoantigens (mitochondrial aconitate hydratase, GADPH, and GPBB) underscore the efficacy of this experimental method and the significance of the spontaneous canine DCM model.