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Flow cytometry was used to demonstrate the presence of beta-lactoglobulin (betaLG) receptors on living murine hybridoma MARK-3 cells using a fluorescein isothiocyanate-betaLG conjugate (FITC-betaLG: molar ratio of 5:1). A site occupation curve was produced using a shift in the mean channel fluorescence at various concentrations of FITC-betaLG. The binding of labelled ligand was concentration dependent and was inhibited by unlabelled betaLG. The on-rate constant was 3.2x10(2) M(-1) min(-1) and the off-rate constant was 0.002 min(-1). Scatchard plot analysis gave a dissociation constant (K(d)) of 44+/-21x10(-7) and 39+/-24x10(-5) M (n=3). Flow cytometry indicated that at least 15% of the FITC-betaLG were internalized for 5 min and that internalization was temperature- and time-dependent. The internalization was confirmed by 3-D fluorescence microscopy (CELLScan system).

SAXS technique is applied on anthracites to study their heterogeneous microtexture and the mechanism of partial graphitization during a thermal treatment up to 2800°C. The effects of heat treatment on the porosity were observed at 1600°C and 2800°C and compared with homogeneous microtextures of mesoporous saccharose-based coke and lamellar anthracene-based coke. The main feature observed on raw anthracites, displaying the least degree of natural maturation and the largest isotropic distribution of aromatic units, is the occurrence of a characteristic distance of 20 A. After a HTT of 1600°C, the porosity of anthracites is close to 10–12%, carbon domains still being weakly organized, particularly on raw anthracites with the higher isotropic microtexture. Discrepancies resulting from the graphitization degree reached at 2800°C were shown using the porosity and the mean length of chord in the matter. The porosity varies respectively from 19%, corresponding to a mean length chord of 97 A for least graphitized anthracites, to 10% and a mean length chord of 235 A for the most graphitized one.

Thrombin plays a central role in thrombosis. Because of the medical need for novel antithrombotic drugs, a search for structurally novel thrombin inhibitors was undertaken. In the absence of a crystal structure, a class was designed based on a modeling approach which involved placing the essential functional groups of the thrombin antagonist MD-805 [1] (Argatroban) into the benzodiazepine nucleus. The best superposition was obtained with a 1,4-benzodiazepin-2-one containing a 1,2,3,4-tetrahydro quinolylsulfonyl moiety in the 3-position, a guanidino-phenyl at the 5-position, and N 1 -substituted with an acetic acid. Synthesis of these molecules provided compounds with an inhibitory activity with K 1 in the range of 40–1000 μJ.M. A report on the crystal structure of thrombin * hirudin(55-65) * MD-805 complex [2] suggested subsequent molecular modeling investigations to rationalize the pharmacological results.

The monophosphate tungsten bronzes (PO 2 ) 4 (WO 3 ) 2 m are quasi two-dimensional conductors which show electronic instabilities of the Peierls type. The m = 7 member of the series P 4 W 14 O 50 , undergoes two successive Peierls transitions at T P 1 = 188 K and T P 2 = 60 K. Weak localisation effects are observed in the low temperature charge density wave state. Resistivity, magnetoresistance and a.c. susceptibility measurements establish that a superconducting transition takes place at temperatures lower than approximately T c = 0.3 K. This indicates that superconductivity is related to parts of the Fermi surface left over after the Peierls gap openings.

We report in this paper some results on the reactivity of different carbon materials, and in particular a set of pitch-coke samples heat treated between 800 and 2400 °C, with sodium. An experimental cell has been designed, which allows carbon to react with sodium vapor at relative pressure close to 0.9 up to 800 °C. The different carbon-sodium samples were examined using X-ray diffraction. The sodium uptake has been related both to intercalation and adsorption or capillary condensation. It is shown that the amount of intercalated sodium cannot be related to one of the structural parameters deduced from the X-ray diffraction patterns or from the Raman spectra of the pristine samples. We then discuss the uncertainty of our results as a function of the crystallite size (La and Lc) of the carbon samples, assuming an in-plane ratio C : Na of 8. Finally, some preliminary results concerning the electrochemical intercalation of sodium in pitch-coke samples heat-treated at different temperatures in a solid state sodium-carbon battery using a polymer electrolyte will be presented in order to assess the amount of intercalated sodium.

Summary Because the structural requirements for the binding of nicotine to central nicotine receptors remain largely uninvestigated, we undertook a systematic investigation of pyrrolidine ring-opened analogs. This led to a subsequent investigation of related conformationally restricted derivatives of these analogs. The results are reported relative to the binding of several well-known and widely used nicotine receptor ligands. Although none of the ring-opened analogs binds with higher affinity than (−)nicotine (Ki = 2.3 nM), 3-(N-methyl-N-ethylaminomethyl)pyridine (12a; Ki = 28 nM) binds with significant affinity. A conformationally restricted analog of 12a, N-methyl [2,7]naphthyridine 30b (Ki = 18 nM), binds with similar affinity. 6-Substitution of 12a and racemic nicotine seems to be tolerated when the substituent is halogen or methyl. In functional studies (hypolocomotion and antinociception in mice; stimulus generalization in nicotine-trained rats) 30b retains nicotine-like properties. Several of the 6-substituted compounds were 2 to 20 times more potent than (±)nicotine. Although the intact pyrrolidine ring of nicotine appears important for optimal affinity, its presence is not an absolute requirement for activity, and 6-position substitution of the pyridine nucleus can influence both binding and functional activity.

The design of reliable reference electrodes for molten fluorides is a major problem, and therefore internal reference systems obtained by in-situ generation of a redox couple were investigated. The Na + Na , Ni 2+ Ni , Mo 3+ Mo and Fe 2+ Fe couples were examined using convolution voltammetry, and the last of these was selected. Galvanostatic pulses were used to generate ferrous ions at the interface between a solid iron electrode and the electrolyte, and then the current was switched off and the system allowed to relax. The redox system was reversible, the theoretical equations were obeyed and the electrode potential determinations were very reproducible. The potential measured at a given time could be used to check the potential of a classical reference or pseudo-reference electrode in molten NaF at 1025°C within ±2 mV.

The present study deals with the high-temperature fracture behaviour of anthracite-based carbon materials. Carbon materials used in aluminium electrolysis cells have a heterogeneous micro-structure and present a complex fracture behaviour. In their application, they are subjected to severe thermo-mechanical solicitations. Thus, the mechanical characteristics of these products must be determined under temperature. Therefore, two experimental apparatus have been set up to determine 1. (a) the flexural strength and the fracture energy from room temperature up to 1400°C under controlled atmosphere (the fracture energy represents the plateau value of the crack growth resistance curve; this curve reports the total energy required to propagate a crack over a given distance) and 2. (b) the Young's modulus by measuring the frequency of vibration of the material from room temperature to 1200°C under controlled atmosphere. The samples are beams of 150 × 30 × 30 mm 3 size in order to be representative of the coarse microstructure (the maximum grain size is 5 mm). The results show an increase of all these characteristics with rising temperature until 1100°C, which is approximately the baking temperature of these carbon materials.

The present study deals with the fracture behaviour of anthracite-based carbon materials. As their behaviour is nonlinear and nonelastic, crack growth resistance curves (R-curves) are determined, and loading-unloading procedure in three-point bending on single-edge notch beams is used. To determine the correct specimen size, a preliminary study of the size effect is performed. The R-curves exhibit a typical shape showing three stages: an increase in growth energy due to process zone development; a plateau value corresponding to steady-state crack propagation, which is used in this study to characterize the behaviour; and a sharp increase of energy due to specimen edge effects. The influence of the microstructure, especially the particle type and orientation, is investigated. Microstructure with higher anthracite fraction leads to easier crack growth. The micromechanisms governing the crack growth conditions are described and discussed.

In refluxing diglyme, the title α-hydroxy imines 7 and 8 rearrange cleanly to amino ketones 9 and 10 substituted on the carbon α to nitrogen by an allyl or a propargyl group. In the case of α-hydroxy imine 9 , the migration of the allyl group occurs with an allylic transposition.

A prototype liquid scintillator-filled halar fibre is described and the results of some preliminary tests designed to demonstrate the feasibility of its use in calorimeter readout are given.