36 research outputs found

    PAN AIR: A Computer Program for Predicting Subsonic or Supersonic Linear Potential Flows About Arbitrary Configurations Using a Higher Order Panel Method

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    An outline of the derivation of the differential equation governing linear subsonic and supersonic potential flow is given. The use of Green's Theorem to obtain an integral equation over the boundary surface is discussed. The engineering techniques incorporated in the PAN AIR (Panel Aerodynamics) program (a discretization method which solves the integral equation for arbitrary first order boundary conditions) are then discussed in detail. Items discussed include the construction of the compressibility transformations, splining techniques, imposition of the boundary conditions, influence coefficient computation (including the concept of the finite part of an integral), computation of pressure coefficients, and computation of forces and moments

    PAN AIR: A computer program for predicting subsonic or supersonic linear potential flows about arbitrary configurations using a higher order panel method. Volume 4: Maintenance document (version 3.0)

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    The Maintenance Document Version 3.0 is a guide to the PAN AIR software system, a system which computes the subsonic or supersonic linear potential flow about a body of nearly arbitrary shape, using a higher order panel method. The document describes the overall system and each program module of the system. Sufficient detail is given for program maintenance, updating, and modification. It is assumed that the reader is familiar with programming and CRAY computer systems. The PAN AIR system was written in FORTRAN 4 language except for a few CAL language subroutines which exist in the PAN AIR library. Structured programming techniques were used to provide code documentation and maintainability. The operating systems accommodated are COS 1.11, COS 1.12, COS 1.13, and COS 1.14 on the CRAY 1S, 1M, and X-MP computing systems. The system is comprised of a data base management system, a program library, an execution control module, and nine separate FORTRAN technical modules. Each module calculates part of the posed PAN AIR problem. The data base manager is used to communicate between modules and within modules. The technical modules must be run in a prescribed fashion for each PAN AIR problem. In order to ease the problem of supplying the many JCL cards required to execute the modules, a set of CRAY procedures (PAPROCS) was created to automatically supply most of the JCL cards. Most of this document has not changed for Version 3.0. It now, however, strictly applies only to PAN AIR version 3.0. The major changes are: (1) additional sections covering the new FDP module (which calculates streamlines and offbody points); (2) a complete rewrite of the section on the MAG module; and (3) strict applicability to CRAY computing systems

    Visible-light-induced intramolecular charge transfer in the radical spirocyclisation of indole-tethered ynones

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    Indole-tethered ynones form an intramolecular electron donor-acceptor complex that can undergo visible-light-induced charge transfer to promote thiyl radical generation from thiols. This initiates a novel radical chain sequence, based on dearomatising spirocyclisation with concomitant C-S bond formation. Sulfur-containing spirocycles are formed in high yields using this simple and mild synthetic protocol, in which neither transition metal catalysts nor photocatalysts are required. The proposed mechanism is supported by various mechanistic studies, and the unusual radical initiation mode represents only the second report of the use of an intramolecular electron donor-acceptor complex in synthesis

    Hand-rolled cigarette smoking patterns compared with factory-made cigarette smoking in New Zealand men

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    <p>Abstract</p> <p>Background</p> <p>Roll-your-own (RYO) cigarettes have increased in popularity, yet their comparative potential toxicity is uncertain. This study compares smoking of RYO and factory-made (FM) cigarettes on smoking pattern and immediate potential toxicity.</p> <p>Methods</p> <p>At a research clinic, 26 RYO and 22 FM volunteer male cigarette smokers, (addicted and overnight-tobacco-abstinent) each smoked 4 filter cigarettes, one half-hourly over 2 hours, either RYO or FM according to usual habit, using the CReSSMicro flowmeter. First cigarette smoked was their own brand. Subsequent cigarettes, all Holiday regular brand, were RYOs (0.5 g tobacco with filter), or FM with filter. Cravings on 100 mm visual analogue scale, and exhaled carbon monoxide (CO) were measured before and after each cigarette smoked.</p> <p>Results</p> <p>Smokers reported similar daily cigarette consumption (RYO 19.0, FM 17.4, p = 0.45), and similar time after waking to first cigarette. (RYO 6.1 minutes, FM 8.6 minutes, p = 0.113). First cigarette's RYO tobacco (0.45 g) weighed less than for FM (0.7 g, p < 0.001); less tobacco was burnt (0.36 g, FM 0.55 g, p < 0.001) but smoking patterns were no different. RYO smokers smoked subsequent cigarettes more intensively; inhaled 28% more smoke per cigarette (RYO 952 mL, FM 743 mL, p = 0.025); took 25% more puffs (RYO 16.9, FM 13.6, p = 0.035); puffed longer (RYO 28 seconds, FM 22 seconds, p = 0.012), taking similar puffs (RYO 57 mL, FM 59 mL). Over four cigarettes, RYOs boosted alveolar CO (RYO 13.8 ppm, FM 13.8 ppm), and reduced cravings (RYO 53%, FM 52%) no differently from FM cigarettes.</p> <p>Conclusion</p> <p>In these smokers, RYO smoking was associated with increased smoke exposure per cigarette, and similar CO breath levels, and even with filters is apparently no less and possibly more dangerous than FM smoking. Specific package warnings should warn of RYO smoking's true risk. RYOs are currently taxed much less than FM cigarettes in most countries; similar harm merits similar excise per cigarette.</p

    Individual and cumulative effects of GWAS susceptibility loci in lung cancer: associations after sub-phenotyping for COPD.

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    Epidemiological studies show that approximately 20-30% of chronic smokers develop chronic obstructive pulmonary disease (COPD) while 10-15% develop lung cancer. COPD pre-exists lung cancer in 50-90% of cases and has a heritability of 40-77%, much greater than for lung cancer with heritability of 15-25%. These data suggest that smokers susceptible to COPD may also be susceptible to lung cancer. This study examines the association of several overlapping chromosomal loci, recently implicated by GWA studies in COPD, lung function and lung cancer, in (n = 1400) subjects sub-phenotyped for the presence of COPD and matched for smoking exposure. Using this approach we show; the 15q25 locus confers susceptibility to lung cancer and COPD, the 4q31 and 4q22 loci both confer a reduced risk to both COPD and lung cancer, the 6p21 locus confers susceptibility to lung cancer in smokers with pre-existing COPD, the 5p15 and 1q23 loci both confer susceptibility to lung cancer in those with no pre-existing COPD. We also show the 5q33 locus, previously associated with reduced FEV(1), appears to confer susceptibility to both COPD and lung cancer. The 6p21 locus previously linked to reduced FEV(1) is associated with COPD only. Larger studies will be needed to distinguish whether these COPD-related effects may reflect, in part, associations specific to different lung cancer histology. We demonstrate that when the "risk genotypes" derived from the univariate analysis are incorporated into an algorithm with clinical variables, independently associated with lung cancer in multivariate analysis, modest discrimination is possible on receiver operator curve analysis (AUC = 0.70). We suggest that genetic susceptibility to lung cancer includes genes conferring susceptibility to COPD and that sub-phenotyping with spirometry is critical to identifying genes underlying the development of lung cancer

    Oxidative cross-linking of calprotectin occurs in vivo, altering its structure and susceptibility to proteolysis

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    Calprotectin, the major neutrophil protein, is a critical alarmin that modulates inflammation and plays a role in host immunity by strongly binding trace metals essential for bacterial growth. It has two cysteine residues favourably positioned to act as a redox switch. Whether their oxidation occurs in vivo and affects the function of calprotectin has received little attention. Here we show that in saliva from healthy adults, and in lavage fluid from the lungs of patients with respiratory diseases, a substantial proportion of calprotectin was cross-linked via disulfide bonds between the cysteine residues on its S100A8 and S100A9 subunits. Stimulated human neutrophils released calprotectin and subsequently cross-linked it by myeloperoxidase-dependent production of hypochlorous acid. The myeloperoxidase-derived oxidants hypochlorous acid, taurine chloramine, hypobromous acid, and hypothiocyanous acid, all at 10 μM, cross-linked calprotectin (5 μM) via reversible disulfide bonds. Hypochlorous acid generated A9-A9 and A8-A9 cross links. Hydrogen peroxide (10 μM) did not cross-link the protein. Purified neutrophil calprotectin existed as a non-covalent heterodimer of A8/A9 which was converted to a heterotetramer - (A8/A9) - with excess calcium ions. Low level oxidation of calprotectin with hypochlorous acid produced substantial proportions of high order oligomers, whether oxidation occurred before or after addition of calcium ions. At high levels of oxidation the heterodimer could not form tetramers with calcium ions, but prior addition of calcium ions afforded some protection for the heterotetramer. Oxidation and formation of the A8-A9 disulfide cross link enhanced calprotectin's susceptibility to proteolysis by neutrophil proteases. We propose that reversible disulfide cross-linking of calprotectin occurs during inflammation and affects its structure and function. Its increased susceptibility to proteolysis will ultimately result in a loss of function

    Chromosomal loci associated with COPD, reduced lung function and Lung Cancer identified by GWA studies and overlap suggested by case-control study.

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    <p>*Available at <a href="http://www.genome.gov/gwastudies" target="_blank">www.genome.gov/gwastudies</a>. Accessed 25/03/2010.</p>§<p>Associated with familial lung cancer <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0016476#pone.0016476-You1" target="_blank">[81]</a>.</p
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