Measurements of the erosion of stainless steel, carbon, and SiC by hydrogen bombardment in the energy range of 0.5 – 7.5 keV

Total erosion yields by sputtering and blistering for 1 to 15 keV H₂⁺ bombardment at normal incidence have been measured by weight loss of 304 stainless steel, pyrolytic graphite, carbon fibres, glassy carbon and SiC. The erosion yields are in the range of 3 × 10⁻³ to 2.6 × 10⁻² atoms per incident hydrogen atom. Observation in the scanning electron microscope shows that blisters occur in stainless steel and SiC at doses of 5 × 10¹⁸ particles/cm², but disappear at doses of 5 × 10 particles/cm² . The surface roughening observed depends largely on grain orientation. On carbon no blistering could be found. After bombardment the carbon surfaces are generally more smooth than before.     

Der Reaktionsverlauf bei der Hydrierung von Triglyceriden Simultanhydrierung von Tri- und Monolinolenin

Course of Reaction During Hydrogenation of Triglycerides — Simultaneous Hydrogenation of Tri- and Monolinolenin Mixtures of trilinolenin and dipalmitomonolinolenin were subjected to hydrogenation. Argentation chromatography resolved the reaction products into two fractions, each containing one of the starting materials and their hydrogenated products. The relative rate of hydrogenation of linolenic acid in both glycerides could be determined by gas chromatography of the transesterified fractions. It was possible to draw conclusions on the course of reaction using mathematical models for various reaction mechanisms, which have been derived earlier¹. Considerable differences in the behaviour of different catalysts were observed. The results could be explained by assuming equal probability of binding of all the glycerides on the catalyst. Depending on the type of catalyst used, spontaneous hydrogenation of several linolenoyl moieties occurred to varying degree.     

Zur Bildung von Ketonen und Aldehyden während der Oxydation gesättigter Triglyceride bei hohen Temperaturen

Formation of Ketones and Aldehydes During the Oxidation of Saturated Triglycerides at High Temperatures Ketones and aldehydes which are formed during the oxidation of tricaprin and tripalmitin were isolated as 2,4-dinitrophenylhydrazones, separated by thin-layer chromatography and quantitatively analysed by UV-spectrometry.     

Phosphorylation of phospholamban correlates with relaxation of coronary artery induced by nitric oxide, adenosine, and prostacyclin in the pig

A silicon-based biosensor microphysiometer measures real time cell response by monitoring an increase in extracellular acidification rate in response to ligands for specific membrane receptors. We used the microphysiometer to identify the minimal structure and critical residues of an antigenic peptide for its interaction with T cell receptor (TCR) using a synthetic peptide analog of human myelin basic protein (MBP) corresponding to residues 84-102 [MBP(83-102)Y83]. MBP(83-102)Y83 peptide analogs were allowed to interact with TCRs on a DRB5*0101-restricted Herpes virus saimiri (HVS) transformed human T cell clone (SS8T) which also contains major histocompatibility complexes (MHC) class II (DR2) molecules. Cultured SS8T cells were exposed to 11 N-terminus and 11 C-terminus truncated peptides separately in the microphysiometer chambers to determine the minimal amino acid residues required for the T cell response. In parallel, 13 analogs of the MBP(83-102)Y83 peptide with single alanine substitutions were tested in this assay to identify critical amino acid residues involved in TCR interactions. A minimal core length of MBP(91-100) peptide and residues F-91, K-93, N-94, I-95 and V-96 were essential for TCR interaction. Acidification rate measurements correlated well with enhanced levels of gamma-IFN (interferon gamma) and TNF-beta cytokine production and suggested that the increase in the extracellular acidification rate is a direct result of early T cell signaling events.     

Anonymous testing of HIV infection in pregnant women

To investigate the contribution of nigral degeneration to the development of parkinsonism in the early stages of corticobasal degeneration (CBD), we measured the cerebrospinal fluid (CSF) levels of homovanillic acid (HVA) in patients with early CBD (n = 5), and compared the levels with those in patients with early Parkinson's disease (n = 11) and in normal subjects (n = 13). The mean CSF HVA level in the early CBD group (33.1 +/- 6.0 ng/ml) did not differ significantly from that in the control group (37.1 +/- 12.7 ng/ml), whereas that in the early Parkinson's disease group (19.0 +/- 7.6 ng/ml) was reduced significantly (P < 0.001). This result suggests that neuronal cell loss in the substantia nigra and presynaptic nigrostriatal dopaminergic neuron dysfunction are mild in the early stages of CBD.     

The thylakoid lumen of chloroplasts. Isolation and characterization

The chloroplast compartment enclosed by the thylakoid membrane, the "lumen," is poorly characterized. The major aims of this work were to design a procedure for the isolation of the thylakoid lumen which could be generally used to characterize lumenal proteins. The preparation was a stepwise procedure in which thylakoid membranes were isolated from intact chloroplasts. Loosely associated thylakoid surface proteins were removed, and following Yeda press fragmentation the lumenal content was recovered in the supernatant following centrifugation. The purity and yield of lumenal proteins were determined using appropriate marker proteins specific for the different chloroplast compartments. Quantitative immunoblot analyses showed that the recovery of soluble lumenal proteins was 60-65% (as judged by the presence of plastocyanin), whereas contamination with stromal enzymes was less than 1% (ribulose-bisphosphate carboxylase) and negligible for thylakoid integral membrane proteins (D1 protein). Approximately 25 polypeptides were recovered in the lumenal fraction, of which several were identified for the first time. Enzymatic measurements and/or amino-terminal sequencing revealed the presence of proteolytic activities, violaxanthin de-epoxidase, polyphenol oxidase, peroxidase, as well as a novel prolyl cis/trans-isomerase.     

Rate of insufficient samples for fine-needle aspiration for nonpalpable breast lesions in a multicenter clinical trial: The Radiologic Diagnostic Oncology Group 5 Study. The RDOG5 investigators

Metaiodobenzylguanidine (MIBG) was developed 18 yr ago for scintigraphic imaging of the adrenomedullary tumors pheochromocytoma and neuroblastoma. Many studies have shown the usefulness of this agent for the management of patients with neuroblastoma or pheochromocytoma, and the 131I-labeled form was recently approved by the Food and Drug Administration for use in the U.S. This article summarizes our current concepts on the diagnostic use of MIBG in children. The radioisotopes available for labeling of MIBG and related compounds, the dosimetry, metabolism and mechanisms of uptake and retention are discussed. Our protocols for imaging both 131I-MIBG and 123I-MIBG, along with the normal distribution of these compounds, are reviewed. The use of MIBG for the management of neuroblastoma, and comparisons with other radiotracers available for imaging neuroblastomas are also addressed.     

Kinetics of plasma fructose and glucose when lactose and fructose are used as energy supplements for neonatal calves

Shortly after birth, plasma glucose and fructose concentrations of the neonate decline and thus leave blood sugar below the homeostatic mode. Two trials were conducted to determine the plasma glucose and fructose kinetics in control and supplemented calves for 108 h after birth. In the short-term trial, six Holstein calves were given 40 g of either fructose, lactose, or water (control) orally at 1 and 96 h after birth. Treatments were administered with a colostrum substitute (Life Boost) at 1 h and whole milk at 96 h. Rectal temperatures and changes in plasma glucose and fructose concentrations were monitored at close intervals for 12 h after supplementation. In the long-term trial, 15 Holstein calves were given 40 g of either lactose, fructose, or water (control) at 1 h after birth and at 12-h intervals for 81 h. Plasma glucose and fructose concentrations were determined before and 4 h after each of the seven feedings. Early postpartal feeding of fructose suppressed plasma glucose (approximately 50%), with a reciprocal rise in plasma fructose. Irrespective of treatment, plasma glucose concentrations did not stabilize (approximately 100 mg/dL) until 17 to 24 h after birth. After 24 h, lactose supplements increased concentrations of plasma glucose 4 h after supplementation (169.7 +/- 8.2 mg/dL), compared with those in calves that did not receive the additional lactose. After 24 h, fructose supplements did not affect plasma glucose, but plasma fructose concentrations increased (82.6 +/- 12.4 mg/dL) 4 h after administration. The response to fructose supplements declined by 11.4 mg x dL(-1) x d(-1). Fructose was not detected in the plasma of control or lactose-treated calves after 17 h after birth. Calves that received fructose supplements had rectal temperatures 8 and 10 h after birth that were higher than those of the other calves. The mechanisms of sugar metabolism change quickly following birth. Oral sugar supplements increase the total plasma sugar concentrations of treated calves.     

Blends of Maltodextrin and Other Polysaccharides as Binders of Aqueous α‐Alumina Suspensions for Ceramic Processing

The aim of the study was to find and investigate some blends of polysaccharides, that could be used as binders and plasticizers in the basic conditions of aqueous alumina suspensions. Aqueous suspensions containing 45% (v/v) α‐alumina and maltodextrin combined with small quantities of other polysaccharides (totally 5 g polysaccharides per 100 g of alumina) were thermally gelled, and their properties characterized by rheological techniques. Gelling formation was found in the systems maltodextrin‐agar, maltodextrin‐agar‐locust bean gum, maltodextrin‐xanthan gum‐locust bean gum, maltodextrin‐xanthan gum and maltodextrin‐carrageenan. The use of maltodextrin was necessary for liquefying the dense aqueous alumina slurries.