Effect of oxygen on the carbon-forming tendencies of diffusion flames

Pre-mixing oxygen with the fuel of diffusion flames markedly increases the level of soot formation, the effect being most pronounced with unsaturated and aromatic hydrocarbons and least with saturated ones. With ethylene, almost five times as much soot is obtained when 10% of the stoichiometric oxygen requirements of the flame is added to the fuel. Larger amounts completely suppress soot emission. The experimental evidence suggests that the role of the oxygen at low concentrations is to promote polymerization of the fuel to high-molecular-weight soot precursors, rather than a thermal effect. After 10 to 15% of the stoichiometric oxygen requirements have been pre-mixed with the fuel, carbon emission is abruptly eliminated over a narrow range of oxygen concentrations. This must be brought about by an oxidation of the fuel or of the potential carbon-forming intermediate which predominates at the higher oxygen concentrations. Dilution of the oxygen with inert gases such as nitrogen, argon and helium reduces its effectiveness to promote the formation of carbon, and appears to be a concentration effect, a conclusion in full agreement with the well known observation that higher pressures lead to increased soot formation. Other free-radical generators such as nitropropane and amyl nitrite also promote soot formation.     

A parallel method for computing the generalized singular value decomposition

We describe a new parallel algorithm for computing the generalized singular value decomposition of two n × n matrices, one of which is nonsingular. Our procedure requires O(n) time and one triangular array of O(n²) processors.     

Moderate dose escalation for advanced stage Hodgkin's disease using the bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, and prednisone scheme and adjuvant radiotherapy: a study of the German Hodgkin's Lymphoma Study Group

The BEACOPP (bleomycin, etoposide, adriamycin, cyclophosphamide, vincristine, procarbazine, and prednisone) regimen, a rearranged and accelerated version of the standard COPP/adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD) chemotherapy, has been shown to be effective and safe in a previous pilot study for advanced stage Hodgkin's disease (HD). The present study aimed to determine a maximum practicable dose of three drugs, ie, etoposide, adriamycin, and cyclophosphamide, for which acute toxicities were acceptable and to assess the feasibility of the escalated scheme. Sixty untreated patients with advanced stage HD were enrolled in this study. Radiotherapy was given in 44 patients (73%) after chemotherapy to initial bulk lesions and residual disease. Granulocyte-colony stimulating factor (G-CSF) was given from day 8 to prevent prolonged neutrocytopenia and severe infections. The intended doses of adriamycin, etoposide, and cyclophosphamide in the BEACOPP schedule could be substantially escalated: adriamycin from 25 to 35, cyclophosphamide from 650 to 1,200, and etoposide from 100 to 200 mg/m2. The major toxicities were leukocytopenia and thrombocytopenia with considerable heterogeneity between individual patients. Of 60 patients, 56 (93%) achieved a complete remission (CR). At a median observation of 32 months, the rates of survival and freedom from treatment failure (FFTF) were estimated to be 91% (95% confidence interval 83% to 99%) and 90% (82% to 98%). These results show that a moderate dose escalation of adriamycin, cyclophosphamide, and etoposide of the baseline BEACOPP regimen is feasible. The escalated BEACOPP regimen shows very encouraging results in advanced stage HD and is now being compared in a randomized phase III study with BEACOPP at baseline dose level.     

Software aspects of business graphics

This paper considers some software and technical issues involved in the production of high quality three dimensional business graphics. It considers whether to use the vector or raster mode, the location or generation of source materials such as type fonts and geographic maps, existing 3-D plotting programs, and some technical issues in the calculation of 3-D plots. Finally it gives some examples of 3-D color plots illustrating different color techniques.     

The myth of evaluating treatment effectiveness.

Suggests an alternative to H. H. Strupp and S. W. Hadley's (see record 1977-29884-001) tripartite model for evaluating treatment outcome, in which primary prevention, self-regulation methods are used to evaluate individuals' ability to control emotions that interfere with everyday functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Antilipidemic drugs. Part 4: The metabolic fate of the hypolipidemic agent isopropyl-[4'-(p-chlorobenzoyl)-2-phenoxy-2-methyl]-protionate (LF 178) in rats, dog and man

The excretion and plasma concentrations of radioactivity and chromatographic patterns of radioactive components in plasma and excreta have been compared in rats, dogs and man after oral doses of the hypolipidemic agent isopropyl-[4'-(p-chlorobenzoyl)-2-phenoxy-2-methyl]-propionate (LF 178; procetofene; Lipanthyl?). 2. In rats, 48.1% of a single dose of 25 mg/kg was excreted in the urine, and 48.6% in the faeces. In dogs, 23.1% of a single dose at the same level was excreted in the urine, and 71.8% in the faeces, but 88.1% of a dose of 300 mg to man was excreted in the urine, and only 5.1% in the faeces. Peak levels of radioactivity in the plasma of all three species studied were similar (20--30 mug/ml) after doses at these levels and concentrations declined thereafter with half-lives of 7--24 h in rats and dogs, and 7 h in man. The half-life of radioactivity concentrations in rat plasma was not altered by repeated daily doses for 7 days. 3. Whole-body autoradiography of rats showed that radioactivity was largely associated with the liver, kidneys and gut, which are the organs of biotransformation and excretion, although relatively high levels were present in lungs and blood, and small amounts of radioactivity had a widespread distribution into some peripheral tissues during 2--7 h after dosing. 4. The available chromatographic evidence indicated that the most important biotransformation pathway appeared to be ester hydrolysis to LF 178 acid and formation of water soluble conjugates of this acid. This pathway appeared similar to that of the related drug clofibrate (ethyl p-chlorophenoxyisobutyrate).     

The resolution of membrane proteins based upon size, charge, and hydrophobicity

Currently available systems for resolving membrane proteins are based only on size and charge differences. Recently, it has been shown that Triton-urea-acetic acid gels which separate proteins on the basis of charge, size and hydrophobicity are capable of resolving proteins differing only by the substitution of a single neutral amino acid. We have applied this new method to the resolution of bacterial envelope proteins. Conditions for optimal resolution of different bacterial envelope proteins were determined by electrophoresis through transverse urea and Triton X-100 gradient gels. We have also correlated the components resolved in this system with those resolved by classical sodium dodecyl sulfate-gel electrophoresis by using two-dimensional slab gels combining the two systems. Furthermore, envelope protein fractions from different species and strains of bacteria were compared to identify specific proteins. This system appears to be a promising method for investigating envelope proteins which are due to missense mutations.