1,538 research outputs found
Approach to the diagnosis and management of suspected exercise-induced bronchoconstriction by primary care physicians
No full textBACKGROUND:
Exercise-related respiratory symptoms in the diagnosis of exercise-induced bronchoconstriction (EIB) have poor predictive value. The aim of this study was to evaluate how athletes presenting with these symptoms are diagnosed and managed in primary care.
METHODS:
An electronic survey was distributed to a random selection of family practitioners in England. The survey was designed to assess the frequency with which family practitioners encounter adults with exercise-related respiratory symptoms and how they would approach diagnostic work-up and management. The survey also evaluated awareness of and access to diagnostic tests in this setting and general knowledge of prescribing asthma treatments to competitive athletes.
RESULTS:
257 family practitioners completed the online survey. One-third of respondents indicated they encountered individuals with this problem at a frequency of more than one case per month. Over two-thirds of family practitioners chose investigation as an initial management strategy, while one-quarter would initiate treatment based on clinical information alone. PEFR pre- and post-exercise was the most commonly selected test for investigation (44%), followed by resting spirometry pre- and post-bronchodilator (35%). Short-acting beta2-agonists were the most frequently selected choice of treatment indicated by respondents (90%).
CONCLUSION:
Family practitioners encounter individuals with exercise-related respiratory symptoms commonly and although objective testing is often employed in diagnostic work-up, the tests most frequently utilised are not the most accurate for diagnosis of EIB. This diagnostic approach may be dictated by the reported lack of access to more precise testing methods, or may reflect a lack of dissemination or awareness of current evidence. Overall the findings have implications both for the management and hence welfare of athletes presenting with this problem to family practitioners and also for the competitive athletes requiring therapeutic use exemption
Low grade rhinovirus infection induces a prolonged release of IL-8 in pulmonary epithelium
No full textRhinoviruses are important respiratory pathogens implicated in asthma exacerbations. The mechanisms by which rhinoviruses trigger inflammatory responses in the lower airway are poorly understood, in particular their ability to infect the lower airway. Bronchial inflammatory cell (lymphocyte and eosinophil) recruitment has been demonstrated. IL-8 is a potent proinflammatory chemokine that is chemotactic for neutrophils, lymphocytes, eosinophils, and monocytes and may be important in the pathogenesis of virus-induced asthma. Increased levels of IL-8 have been found in nasal samples in natural and experimental rhinovirus infections. In these studies we therefore examine the ability of rhinovirus to infect a transformed lower airway epithelial cell line (A549) and to induce IL-8 protein release and mRNA induction. We observed that rhinovirus type 9 is able to undergo full viral replication in A549 cells, and peak viral titers were found 24 h after inoculation. Rhinovirus infection induced a dose- and time-dependent IL-8 release up to 5 days after infection and an increase in IL-8 mRNA expression that was maximal between 3 and 24 h after infection. UV inactivation of the virus completely inhibited replication, but only reduced IL-8 protein production and mRNA induction by half, while prevention of virus-receptor binding completely inhibited virus-induced IL-8 release, suggesting that part of the observed effects was due to viral replication and part was due to virus-receptor binding. These studies demonstrate that rhinoviruses are capable of infecting a pulmonary epithelial cell line and inducing IL-8 release. These findings may be important in understanding the pathogenesis of rhinovirus-induced asthma exacerbations
Invariant tori and Lagrange stability of pendulum-type equations
No full textAbstractIn this paper we prove that the pendulum-type equation x″ + g(t, x) = 0 possesses infinitely many invariant tori whenever g(t, x) has zero mean value on the torus T2, where g(t, x) belongs to C∞(T2). This yields the boundedness for solutions of the considered pendulum-type equation and thus leads to an answer to J. Moser's boundedness problem (1973, Ann. of Math. Stud. 77)
The charged and the spin-excitation gaps in the double-exchange model: a rigorous result
No full textWe extend a previous result of ours [G.S. Tian, Phys. Rev. B58 (1998) 7612] on the charged gap and the spin-excitation gap of the half-filled Kondo lattice model to the double-exchange model. In our original approach, this model cannot be dealt with since its localized spins have a large spin number S = 3/2. By following a construction argument due to Zener and rewriting the double-exchange Hamiltonian, we are able to overcome this difficulty and re-establish the same relation for this model.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000088659700004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, MultidisciplinarySCI(E)中国科学引文数据库(CSCD)3ARTICLE121-303
A 2-watt balanced power amplifier MMIC for Ku-band satellite communications
No full textA Ku-band power amplifier MMIC has been developed using 0.25-mum GaAs pHEMT technology. To achieve small chip size and simple drain-bias connection, a bus-bar power combiner is used. Also, balanced-power amplifier topology is used to obtain good input/ output return losses. The small-signal gain is about 15 dB and the gain variation is less than 1 dB from 12 to 17 GHz. Good input/output return losses are achieved at less than -15 dB due to the balanced topology. P-IdB of 32.6 dBm and PAE of 23.5% are achieved at 14 GHz. The effective chip area is 4.2 X 3.2 mm. Because the power amplifier is implemented using the balanced topology with the bus-bar power combiner, compact size, high output power, and good input/output return losses can be achieved simultaneously. (C) 2004 Wiley Periodicals, Inc.The author would like to thank Jeong-Ho Lee, Chung-Hwan Kim,
and Jae-Jin Lee at Teltron for their helpful discussions and encouragement.
This work was supported by KOSEF under the ERC
program through the MINT research center at Dongguk University
Flexicurity - Useful Oxymoron or Genuine Class Compromise?
No full textAuthor has checked copyrightDG 16/11/12Names JG 2012-11-1
Gesetzliche Mindestlöhne in Irland
No full textAuthor has checked copyrightDG 16/11/12Names JG 2012-11-1
The Dirichlet Problem for the Degenerate Elliptic Monge–Ampère Equation
No full textAbstractThe existence and uniqueness of the global C1,1/3 solution to the Dirichlet problem for the degenerate elliptic Monge–Ampère equation are proved, under mild conditions, and the application to the equation of the prescribed nonnegative Gauss curvature is also given
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