Structural, magnetic and electronic properties of pulsed-laser-deposition grown SrFeO3-δ thin films and SrFeO3-δ /La2/3Ca1/3MnO3 multilayers.

We studied the structural, magnetic and electronic properties of [Formula: see text] (SFO) thin films and [Formula: see text]/[Formula: see text] [Formula: see text]MnO3 (LCMO) superlattices that have been grown with pulsed laser deposition (PLD) on [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] (LSAT) substrates. X-ray reflectometry and scanning transmission electron microscopy (STEM) confirm the high structural quality of the films and flat and atomically sharp interfaces of the superlattices. The STEM data also reveal a difference in the interfacial layer stacking with a SrO layer at the LCMO/SFO and a LaO layer at the SFO/LCMO interfaces along the PLD growth direction. The x-ray diffraction (XRD) data suggest that the as grown SFO films and SFO/LCMO superlattices have an oxygen-deficient [Formula: see text] structure with I4/ mmm space group symmetry ([Formula: see text]). Subsequent ozone annealed SFO films are consistent with an almost oxygen stoichiometric structure ([Formula: see text]). The electronic and magnetic properties of these SFO films are similar to the ones of corresponding single crystals. In particular, the as grown [Formula: see text] films are insulating whereas the ozone annealed films are metallic. The magneto-resistance effects of the as grown SFO films have a similar magnitude as in the single crystals, but extend over a much wider temperature range. Last but not least, for the SFO/LCMO superlattices we observe a rather large exchange bias effect that varies as a function of the cooling field.

Enhanced figure of merit in nanostructured (Bi,Sb)2Te3 with optimized composition, prepared by a straightforward arc-melting procedure.

Sb-doped Bi2Te3 is known since the 1950s as the best thermoelectric material for near-room temperature operation. Improvements in material performance are expected from nanostructuring procedures. We present a straightforward and fast method to synthesize already nanostructured pellets that show an enhanced ZT due to a remarkably low thermal conductivity and unusually high Seebeck coefficient for a nominal composition optimized for arc-melting: Bi0.35Sb1.65Te3. We provide a detailed structural analysis of the Bi2-xSbxTe3 series (0 ≤ x ≤ 2) based on neutron powder diffraction as a function of composition and temperature that reveals the important role played by atomic vibrations. Arc-melting produces layered platelets with less than 50 nm-thick sheets. The low thermal conductivity is attributed to the phonon scattering at the grain boundaries of the nanosheets. This is a fast and cost-effective production method of highly efficient thermoelectric materials.

Isolation and characterization of a human liver and kidney-specific protein: the hepato-renal (H-R) antigen.

This paper reports the isolation and characterization of a soluble antigen shared by the liver and kidney of human and some other animal species. Homogenates of human liver in saline were centrifugated at 27,000 g and the supernatants were fractionated by preparative polyacrylamide gel electrophoresis. The gels were divided in sections and each was injected into rabbits; after absorption with polymerized normal human serum, the antiserum obtained by injecting one of the sections reacted only with saline extracts of human liver and kidney when tested against a variety of human tissue extracts. The absorbed antiserum, polymerized and insolubilized with glutaraldehyde, was used to purify the antigen by affinity chromatography. The purified antigen proved to be a glycoprotein containing 19 percent carbohydrate, had a molecular weight of 5.8-6.0 x 10(4) Daltons and a pI of 7.2-7.4. The antigen, relatively thermostable, was precipitated by 35-55 percent ammonium sulphate; its antigenic activity was not affected by extraction with 0.6 N perchloric acid or by incubation with ribonuclease, deoxyribonuclease or neuraminidase but was destroyed by incubation with ttypsin or chymotrypsin. Immunoperoxidase studies showed that the antigen appeared concentrated in the neclei of liver and kidney glomerular epithelial and tubular epithelial cells in humans and rats. The antigen could not be detected in human hepatomas or hypernephromas or in the rat Morris hepatoma 5123.

Isolation and characterization of a human pancreas-specific protein.

Homogenates of human pancreas in saline were centrifuged at 27 000 X g and the supernates were fractionated by preparative polyacrylamide gel electrophoresis. The gels were divided into sections and each section was injected into rabbits; after absorption with polymerized serum from apparently normal humans, the antiserum obtained by injecting one of the sections was tested against a variety of human tissue extracts but reacted only with saline extracts of human pancreas. The absorbed antiserum, polymerized and made insoluble with glutaraldehyde, was used to purify a pancreas-specific antigen by immunoaffinity batch technique. The purified antigen proved to be a protein with some carbohydrate content (180 mg/g by weight) and a molecular mass of about 2.25 X 10(5) daltons. The antigen is relatively thermostable, and precipitates in the range of 245.64-340.2 g/L saturated ammonium sulfate; its antigenic activity is not affected by incubation with ribonuclease or deoxyribonuclease, but is destroyed by incubation with trypsin or neuraminidase and by extraction with perchloric acid. Immunofluorescence studies show that the antigen is diffusely present in the cytoplasm of pancreatic acinar cells.

Radioimmunoassay for detection of latent chronic alcoholic pancreatitis, an unrecognized clinical syndrome.

We developed a radioimmunoassay procedure in which we used an antibody monospecific for pancreatic acinar antigen, to sensitively and specifically test for the presence of subclinical (latent) alcoholic pancreatitis. The antigen was isolated, purified, and partially characterized. Results of testing appropriate populations of patients support the idea that chronic alcoholism is associated with chronic, subclinical damage to the pancreas and concomitant continuous release of a pancreatic acinar protein into the peripheral circulation, where it can be detected and quantitated. About 40% of the samples from chronic alcoholics (whether during a bout of acute alcoholism or during abstinence) demonstrated the circulating antigen, strongly suggesting that those alcoholics who will develop symptomatic, chronic alcoholic pancreatitis can be readily detected during the non-symptomatic stage.

Hematological response of rabbits to chronic, repetitive, severe bleedings for the production of antisera.

A study was undertaken to determine whether large amounts of blood (antiserum) could be rapidly removed from rabbits over a two-month period using a simple suction technique. It was found that half a blood volume could be readily removed each week (over 900 ml/rabbit/54 days) without a single fatality. The rabbits efficiently replaced the essential components of their blood during the experimental period as shown by a study of their blood parameters. They moderately overcompensated in replacing some of their blood components after a 6-week rest period. The study demonstrates that rabbits are satisfactory (in lieu of larger animals) for supplying relatively large amounts of antisera.

Insoluble human plasma protein immunoadsorbents. Large-scale production and storage.

Methods for producing and preserving large volumes of insoluble immunoadsorbents (for removing unwated antibodies to serum proteins) from surplus blood bank plasma by glutaraldehyde were evaluated by quantitative and qualitative means using radioactive 125I and immunoelectrophoresis, respectively. Some of the factors affecting the desired physical characteristics and antibody-absorbing properties of the imjunoadsorbent studied were: plasma acidification, varying concentrations of glutaraldehyde, addition of small amounts of formalin, storage under varying conditions of temperature, and exposure to preservatives in the wet and lyophilized state for periods up to 2.5 years. The best preservation of antibody-adsorbing properties (under storage conditions) was obtained in the washed state at 4 degrees C, but good preservation was also obtained at room temperature in the presence 10% formalin and in the unwashed state at room temperature in the presence of unreacted glutaraldehyde. Lyophilization destroyed about 70% of an adsorbent's activity.