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.     

Robust estimates of the theoretical standard deviation to be used in interlaboratory precision experiments

Interlaboratory experiments often contain results that strongly deviate from other results obtained in the same laboratory under repeatability conditions, or laboratory means that strongly deviate from other laboratory means. In ISO 5725-2 [1] and IUPAC [2], the basic standards for the organisation and analysis of interlaboratory experiments for the determination of precision of a measurement method, outlier tests are performed in order to detect such situations and to finally decide whether these values are retained in the analysis or discarded as outliers. This outlier treatment, which always has a subjective aspect, becomes unnecessary by using robust estimates of the repeatability and reproducibility standard deviation. This paper proposes to use Rousseeuw’s Q _n as an extremely robust and efficient estimate of the standard deviation. Two examples show the performance of the new method.     

A simple method of constructing a confidence interval for the mean probability of detection in collaborative studies of binary measurement methods

We deal with collaborative studies where each of k laboratories performs n repeated binary measurements (measurement result x = 0: “not detected”; measurement result x = 1: “detected”), and present a simple method of constructing a confidence interval for the mean probability of detection of the laboratories. This method is based on an approximation of the distribution of the number y of detections among n independent measurements of a randomly chosen laboratory by a binomial distribution. The confidence interval is not only much easier to calculate but also more accurate than the profile likelihood interval presented by Uhlig et al.     

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.     

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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.