Undifferentiated (embryonal) sarcoma of the liver: pathologic basis of imaging findings in 28 cases

An acidic 1,2-alpha-mannosidase from fungus, Aspergillus saitoi (now designated Aspergillus phoenicis), is highly specific for 1,2-alpha-mannosidic linkage in the high-mannose type oligosaccharide at pH 5.0. The predicted amino acid sequence of several peptide regions, including aspartic acid and glutamic acid, bears striking similarities to 1,2-alpha-mannosidases from fungi, yeast and mouse. Active site determination of the enzyme expressed in Saccharomyces cerevisiae cells was performed by site-directed mutagenesis. Substitutions of Asp-269 to Glu and of the Glu-residues, Glu-273, Glu-411, Glu-414 and Glu-474, to Asp altered the drastic decrease of specific activities with Man alpha 1-2Man-OMe and Man9-GlcNAc2-PA as substrates and shifted the optimal pH of the mutant enzymes. From the present results, Asp-269 is probably in the ionized COO- form, whereas one of four glutamic acid residues, probably Glu-411, is the un-ionized COOH form according to the analogy of a plausible mechanism for lysozyme catalysis. It is assumed that three glutamic acid residues, Glu-273, Glu-414, and Glu-474, are probably binding sites of substrate.     

Quantification of particle number and mass emission factors from combustion of Queensland trees

The quantification of particle emission factors under controlled laboratory conditions for burning of the following five common tree species found in South East Queensland forests has been studied: Spotted Gum (Corymbia citriodora), Blue Gum (Eucalyptus tereticornis), Bloodwood (Eucalyptus intermedia), Iron Bark (Eucalyptus crebra), and Stringybark (Eucalyptus umbra). The results of the study show that the particle number emission factors and PM2.5 mass emission factors depend on the type of tree and the burning rate. For fast burning conditions, the average particle number emission factors are in the range of 3.3-5.7 x 10(15) particles/kg for woods and 0.5-6.9 x 10(15) particles/kg for leaves and branches, and the PM2.5 emission factors are in the range of 140-210 mg/kg for woods and 450-4700 mg/kg for leaves and branches. For slow burning conditions, the average particle number emission factors are in the range of 2.8-44.8 x 10(13) particles/kg for woods and 0.5-9.3 x 10(13) particles/kg for leaves and branches, and the PM2.5 emissions factors are in the range of 120-480 mg/kg for woods and 3300-4900 mg/kg for leaves and branches.     

A plume capture technique for the remote characterization of aircraft engine emissions

A technique for capturing and analyzing plumes from unmodified aircraft or other combustion sources under real world conditions is described and applied to the task of characterizing plumes from commercial aircraft during the taxiing phase of the Landing/Take-Off (LTO) cycle. The method utilizes a Plume Capture and Analysis System (PCAS) mounted in a four-wheel drive vehicle which is positioned in the airfield 60 to 180 m downwind of aircraft operations. The approach offers low test turnaround times with the ability to complete careful measurements of particle and gaseous emission factors and sequentially scanned particle size distributions without distortion due to plume concentration fluctuations. These measurements can be performed for individual aircraft movements at five minute intervals. A Plume Capture Device (PCD) collected samples of the naturally diluted plume in a 200 L conductive membrane conforming to a defined shape. Samples from over 60 aircraft movements were collected and analyzed in situ for particulate and gaseous concentrations and for particle size distribution using a Scanning Particle Mobility Sizer (SMPS). Emission factors are derived for particle number, NO(x), and PM2.5 for a widely used commercial aircraft type, Boeing 737 airframes with predominantly CFM56 class engines, during taxiing. The practical advantages of the PCAS include the capacity to perform well targeted and controlled emission factor and size distribution measurements using instrumentation with varying response times within an airport facility, in close proximity to aircraft during their normal operations.     

An evaluation of the role of radiation and nonradiation factors in the development of lung cancer in workers at a radiochemical enterprise (1)

A case-control study using logistic regression included 500 employees of the nuclear works (162 patients with lung carcinoma and 338 healthy controls). After examination of radiation and nonradiation causative factors 5 proved statistically significant. For them the following chance proportions were obtained: smoking 6.6, plutonium pneumosclerosis 4.6, plutonium incorporation 3.1, chronic nonspecific pulmonary diseases 2.1, external gamma-radiation 1.6. Attributive risk for the total of the radiation factors makes up 25% at the most while of the nonradiation factors at least 70%.     

Improved detection of coronary artery disease by exercise electrocardiography with the use of right precordial leads

BACKGROUND: Exercise electrocardiography is an perfect test for the detection of coronary artery disease. We attempted to improve the diagnostic accuracy of exercise testing as a noninvasive method for the detection of coronary artery disease by using a combination of the left and right precordial leads. METHODS: We studied 245 patients (218 men and 27 women) ranging from 32 to 74 years of age (mean [+/-SD], 52+/-8) who underwent treadmill exercise testing, thallium-201 scintigraphy, and coronary arteriography. During exercise testing, each patient had one electrocardiogram recorded with the standard 12 leads and 3 right precordial leads (V3R, V4R, and V5R), with the results for each set of leads recorded and analyzed separately. RESULTS: On the basis of coronary arteriography, 34 patients had normal coronary arteries, 85 had single-vessel disease, 84 had two-vessel disease, and 42 had three-vessel disease. The sensitivities of the standard 12-lead exercise electrocardiogram, exercise electrocardiography incorporating right precordial leads, and thallium-201 scintigraphy were 52 percent, 89 percent, and 87 percent, respectively, for the detection of single-vessel disease; 71 percent, 94 percent, and 96 percent for the detection of two-vessel disease; 83 percent, 95 percent, and 98 percent for the detection of three-vessel disease; and 66 percent, 92 percent, and 93 percent for the detection of any coronary artery disease. The specificities of the three methods for the detection of any coronary artery disease were 88 percent, 88 percent, and 82 percent, respectively. CONCLUSIONS: Use of right precordial leads along with the standard six left precordial leads during exercise electrocardiography greatly improves the sensitivity of exercise testing for the diagnosis of coronary artery disease.     

Emissions from a vehicle fitted to operate on either petrol or compressed natural gas

The purpose of this work was to evaluate the physical and chemical properties of emission products from a six-cylinder sedan car under a variety of operating conditions, before and after it has been converted to compressed natural gas (CNG) fuel. The specific focus of the measurements was on emission levels and characteristics of ultra fine particles and the emission levels together with the emissions of gaseous pollutants for a range of operating conditions before and up to 3 months after the vehicle was converted are presented and discussed in the paper. The investigations showed that converting a petrol operating vehicle to CNG has the potential of reducing some of the emissions and thus risks, while it does not appear to have an impact on others. In particular there was no statistically significant change in the emission of particles for the vehicle operating on petrol, before the conversion, compared to the emissions for the vehicle operating on CNG, after the conversion. There was a significant lowering of emissions of total polycyclic aromatic hydrocarbons and formaldehyde when the vehicle was operated on CNG, and a reduction of global warming potential was also observed when the vehicle was run on CNG, but the later gain is only at high vehicle speeds/loads, and would thus have to be considered in view of traffic and transport models for the region (in these models vehicle speed is an important parameter).