Film autoradiography used for hot particle identification

Summary Two types of films were tested and compared for the purposes of film autoradiography. Commercial black and white photographic film proved to have the highest sensitivity and the best resolution. The film was calibrated by specially prepared sources that contained alpha- and beta-emitting isotopes in the form of particles. Application examples for hot particle identification using the developed film autoradiographic technique are given.     

Temperature dependence of the hydrogen resistivity in HCP lutetium: Observation of the Manninen-Jena effect

We have measured the temperature dependence of the electrical resistivity between 4.4 and 170 K in α-Lu(H, D)_x, with 0 ? x ? 0.2, in order to test the predictions of Manninen and Jena. The latter are confirmed as concerns the temperature dependence of the hydrogen resistivity and the isotope effect. In addition, we have obserced an H-concentration dependent turning-in temperature for excitation to higher excited states, which can be related to a varying binding energy of the H-H pairs prevailing in this temperature range in our system.     

Preparation of zirconium phosphate on support material and its application for the sorption of some radioions

Several sorbents were prepared by precipitating zirconium phosphate on activated carbon support material. The main parameters of the chemical procedure were optimized in order to obtain the highest decontamination factors which can be achieved in the case of Cs⁺, Sr²⁺ and I⁻ ions. For the characterization of the sorbents, sorption isotherms and capacity data were determined. The reproducibility of the preparation is about 10%.     

The g-factors of isomeric states in127, 128Xe

Excited states in^{127, 128}Xe were populated in the reaction⁹Be+¹²²Sn atE _lab=38 MeV. The de-excitation of the isomeric states 7/2⁺ in¹²⁷Xe and 8^? in¹²⁸Xe was studied using angular distribution and TDPAD methods on molten¹²²Sn targets. The results are $$\begin{gathered} T_{1/2} (7/2^ + ) = 37 \pm 1 ns, g(7/2^ + ) = + 0.241 \pm 0.009 \hfill \\ T_{1/2} (8^ - ) = 83 \pm 2 ns, g(8^ - ) = - 0.036 \pm 0.009. \hfill \\ \end{gathered}$$ The experimentalg-factors suggest the main configurationsvg _7/2 andvh _11/2 g _7/2 for the isomeric states. Detailed analysis of the combined information fromg-factors and transition rates set stringent limits on the admixtures of the wave functions. The quasirotational bands built on the two-quasiparticle 6^? and 10⁺ states are extended to higher spins, (14^?) and (16⁺), respectively, and their structures are analyzed within the framework of the Interacting Boson Model.     

Study of relaxation processes in monomolecular films by the step compression experiment

Maxwell's displacement current flowing through a metal electrode/air gap/Langmuir monolayer was detected. MDC experimental results obtained during a step compression mode are presented and contrasted with the Debye-Brown rotational model. As an alternative approach a theoretical model based on an analogy with a nonideal gas of polar molecules is derived from Lagrange's equation of motion.     

A new class of metric divergences on probability spaces and its applicability in statistics

The classI _f β, βε(0, ∞], off-divergences investigated in this paper is defined in terms of a class of entropies introduced by Arimoto (1971,Information and Control,19, 181–194). It contains the squared Hellinger distance (for β=1/2), the sumI(Q ₁‖(Q ₁+Q ₂)/2)+I(Q ₂‖(Q ₁+Q ₂)/2) of Kullback-Leibler divergences (for β=1) and half of the variation distance (for β=∞) and continuously extends the class of squared perimeter-type distances introduced by Österreicher (1996,Kybernetika,32, 389–393) (for βε (1, ∞]). It is shown that\((I_{f_\beta } (Q_1 ,Q_2 ))^{\min (\beta ,1/2)}\) are distances of probability distributionsQ ₁,Q ₂ for β ε (0, ∞). The applicability of\(I_{f_\beta }\)-divergences in statistics is also considered. In particular, it is shown that the\(I_{f_\beta }\)-projections of appropriate empirical distributions to regular families define distribution estimates which are in the case of an i.i.d. sample of size'n consistent. The order of consistency is investigated as well.     

Analysis of colorectal adenocarcinoma tissue by desorption electrospray ionization mass spectrometric imaging

Negative ion desorption electrospray ionization (DESI) was used for the analysis of an ex vivo tissue sample set comprising primary colorectal adenocarcinoma samples and colorectal adenocarcinoma liver metastasis samples. Frozen sections (12 μm thick) were analyzed by means of DESI imaging mass spectrometry (IMS) with spatial resolution of 100 μm using a computer-controlled DESI imaging stage mounted on a high resolution Orbitrap mass spectrometer. DESI-IMS data were found to predominantly feature complex lipids, including phosphatidyl-inositols, phophatidyl-ethanolamines, phosphatidyl-serines, phosphatidyl-ethanolamine plasmalogens, phosphatidic acids, phosphatidyl-glycerols, ceramides, sphingolipids, and sulfatides among others. Molecular constituents were identified based on their exact mass and MS/MS fragmentation spectra. An identified set of molecules was found to be in good agreement with previously reported DESI imaging data. Different histological tissue types were found to yield characteristic mass spectrometric data in each individual section. Histological features were identified by comparison to hematoxylin-eosin stained neighboring sections. Ions specific to certain histological tissue types (connective tissue, smooth muscle, healthy mucosa, healthy liver parenchyma, and adenocarcinoma) were identified by semi-automated screening of data. While each section featured a number of tissue-specific species, no potential global biomarker was found in the full sample set for any of the tissue types. As an alternative approach, data were analyzed by principal component analysis (PCA) and linear discriminant analysis (LDA) which resulted in efficient separation of data points based on their histological types. A pixel-by-pixel tissue identification method was developed, featuring the PCA/LDA analysis of authentic data set, and localization of unknowns in the resulting 60D, histologically assigned LDA space. Novel approach was found to yield results which are in 95% agreement with the results of classical histology. KRAS mutation status was determined for each sample by standard molecular biology methods and a similar PCA/LDA approach was developed to assess the feasibility of the determination of this important parameter using solely DESI imaging data. Results showed that the mutant and wild-type samples fully separated. DESI-MS and molecular biology results were in agreement in 90% of the cases.     

Finite-state and reduced-parameter representations of protein backbone conformations

This article studies the representation of protein backbone conformations using a finite number of values for the backbone dihedral angles. We develop a combinatorial search algorithm that guarantees finding the global minima of functions over the configuration space of discrete protein conformations, and use this procedure to fit finite-state models to the backbones of globular proteins. It is demonstrated that a finite-state representation with a reasonably small number of states yields either a small root-mean-square error or a small dihedral angle deviation from the native structure, but not both at the same time. The problem can be resolved by introducing limited local optimization in each step of the combinatorial search. In addition, it is shown that acceptable approximation is achieved using a single dihedral angle as an independent variable in local optimization. Results for 11 proteins demonstrate the advantages and shortcomings of both the finite-state and reduced-parameter approximations of protein backbone conformations. © 1994 by John Wiley & Sons, Inc.