2,709 research outputs found
Bryn Hammarstrom, Sr. Interview, August 4, 1989
Bryn Hammarstrom describes smokejumper training at Seeley Lake, Montana, where he was sent after applying for conscientious objector status during World War Two. He talks about his smokejumper duties, which included repairing and packing parachutes. He recalls specific jumps including one in Yellowstone Park. He recalls some specific incidents during his Civilian Public Service [CPS] years including a truck accident, smokejumper training at Nine Mile, Montana, and assisting with a bridge removal in St. Regis, Montana.
This is not an audio interview. Hammarstrom responds in writing to a series of questions sent to him by Roxanne Farwell.https://scholarworks.umt.edu/civilianpublicservicesmokejumpers_oralhistory/1019/thumbnail.jp
Synthetic Peptides: Design, Structure and Biological Function.
The synthesis of a series of polyfunctional Calpha,C alpha-disubstituted glycines is described. The lysine-like amino acid analog, Api, was prepared by regioselective hydrolysis of a triBoced hydantoin, followed by Nalpha-protection to yield the first orthogonally protected ionizable Calpha,Calpha-disubstituted amino acid which is alicyclic. The synthesis of three orthogonally protected tetrafunctional amino acids, Bap, Bglu, and Basp was envisioned by alkylation of the organic synthon ethyl nitroacetate. Subsequent regioselective modification should allow for the isolation of the first tetrafunctional amino acid derivatives suitable for solid-phase synthesis. These amino acids are designed to induce peptide secondary structure by salt-bridge stabilization. A series of peptides, incorporating 80% Calpha,C alpha-disubstituted glycines were synthesized to establish the helix stabilizing effect of amphipathicity in short helices. The peptides were prepared as permutation isomer pairs, Pi-10 & Ipi-10; Ach-10alpha & Ach-10; and Cyh-10 & Ich-10. The peptides within each pair contain the same amino acid content, with different sequences, each designed to preferentially adopt a 310- or alpha-helix. Circular dichroism confirms that amphipathicity is a significant factor in shifting the 310-/alpha-helix equilibrium, notably so in micellar environments. The bioactivity of the aforementioned peptides was established by minimum inhibitory concentrations (MICs) against representative Gram-positive and Gram-negative bacteria. The more hydrophobic peptides showed higher levels of cytotoxicity than the less hydrophobic peptides. In vitro studies using a strain of Brucella abortus expressing Green Fluorescent Protein (GFP) show that all of the peptides exhibit moderate to high selectivity towards the destruction of murine macrophages infected with the intracellular pathogen. The spectroscopic properties of the o-nitrobenzenesulfonyl (oNBS) group have been established to confirm the practical use of this protecting group in solid-phase synthesis. Synthesis of the deprotection product, resulting from treatment of the oNBS-protected amino acid with mercaptoacetic acid/DBU, shows a linear correlation between concentration and absorption at 390 nm. Molar absorptivity, &egr;390 was determined to be 2950 cm-1M-1. This number was verified by solution-phase cleavage of several oNBS-protected Calpha,Calpha-disubstituted amino acids, which were synthesized by a modified Bolin procedure to allow for synthesis under non-aqueous conditions
Mitogenic leukoagglutinin from Phaseolus vulgaris binds to a pentasaccharide unit in N-acetyllactosamine-type glycoprotein glycans.
CEA, CYFRA 21-1, NSE, and ProGRP in the diagnosis of lung cancer: a multivariate approach
We retrospectively studied the single and combined diagnostic value of carcinoembryonic antigen (CEA), cytokeratin fragment 19 (CYFRA 21-1), neuron specific enolase (NSE) and pro-gastrin-releasing peptide (ProGRP), which were routinely analysed in patients with lung tumours of unknown origin at the time of admission to hospital. Inclusion criteria were the determination of CEA (AxSYM/Abbott), CYFRA 21-1 (ElecSys/Roche) and NSE (Kryptor/Brahms). We examined 1747 patients, where 1325 suffered from lung cancer (LC; small cell lung cancer, SCLC: n=194; non-small cell lung cancer, NSCLC: n = 1015; others: n = 116), 318 from benign lung diseases and 104 from lung metastases due to another primary malignancy. As ProGRP (ELISA ALSI/IBL) became available only recently, there are less data points of this marker. In total, 99.8% of LC patients released at least one of the four biomarkers (defined as values exceeding the median of healthy controls), and for the discrimination between benign disease (BID) and malignant lung disease each marker reached 100% tumour specificity at high levels (CEA: 20 ng/mL; CYFRA 21-1: 40 ng/mL; NSE: 45 ng/mL; ProGRP: 250 pg/mL). At a specificity of > 99%, ProGRP reached the highest diagnostic efficacy for SCLC with 57% true positive results, CEA had the highest capacity (17%) to detect malignant lung tumours in general and adenocarcinomas of the lung with 29%. CYFRA 21-1 was dominant for squamous cell carcinomas (12%). Combining the four markers leads with the prerequisite of high specificity (> 99%) to 50% true positives for malignant lung tumours, 44% for NSCLC, 36% for squamous cell carcinomas, 53% for adenocarcinomas, and 78% for SCLC, respectively. In cases of lung tumours of unknown origin, the combined use of CEA, CYFRA 21-1, NSE and ProGRP is useful for the differentiation between benign and primary or secondary malignant disease and suggests the assignment to histological subtypes
Theoretical Aspects of Microchannel Acoustofluidics:Thermoviscous Corrections to the Radiation Force and Streaming
AbstractWe study the effects of the temperature dependence of viscosity and density on the acoustic radiation force and the boundary-driven acoustic streaming in microchannel acoustofluidics. The acoustic streaming slip velocity for the bulk flow is calculated numerically taking these thermoviscous effects into account inside the micrometer-thin acoustic boundary layer and compare the results to recent analytical work in the literature. The acoustic radiation force is calculated for the case of an ultrasound wave scattering on a compressible, spherical particle suspended in a viscous, thermal conducting fluid. Using Prandtl–Schlichting boundary-layer theory, we include the viscosity and the volume thermal expansion coeffcient of the fluid and derive an analytical expression for the radiation force. The resulting force (valid for particle radius and boundary layers much smaller than the acoustic wavelength) is analyzed for microchannel acoustophoresis
Molecular cloning and expression of cDNA for a carcinoembryonic antigen-related fetal liver glycoprotein.
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