2,350 research outputs found
The use of inhaled corticosteroids in the treatment, of bronchial asthma with particular reference to beclomethasome dipropionate.
MDThe Problem :
Corticosteroids may be necessary to control the symptoms of many
patients with chronic bronchial asthma, their use, however, is frequently
complicated by side effects, which are unpleasant for the patient and
often worrying for the physician. Any measure, therefore, which would
permit a useful anti-inflammatory effect of these drugs whilst minimising
side effects would be of benefit to patients. It is for this reason that,
for over twenty years, repeated attempts have been made with every corticosteroid
as they have been introduced, to administer them directly onto the
bronchial mucous membrane by inhalation in one form or another. These
attempts have failed, probably because the steroids used have had potent
systemic glucocorticoid effects following any route of administration. The
use of inhaled beclomethasone-17,21-dipropionate, however, is in marked
contrast to the earlier experiences with inhaled corticosteroids, because
the symptoms of bronchial asthma are controlled without important. corticosteroid
induced side effects. The aim of this thesis is twofold, first,
to establish by simple means, the properties of beclomethasone-17, 21-
dipropionate in in an attempt to discover, the reasons why this corticosteroid
should be successful when given by inhalation whilst others were
not, and secondly, to discover whether the regular use of an inhaled
corticosteroid may be complicated by any side effects, peculiar to this
route of administration.
Summary of the Present Work :
The use of corticosteroids in the treatment of bronchial asthma, and,
the attempts to reduce side effects by clinical means, including the local,
inhaled use of corticosteroids are reviewed. The work of steroid chemists
aimed at producing compounds where there may be some separation of antiinflammatory from other glucocorticoid effects is outlined. The literature
on inhaled beclomethasone-l7, 2l-dipropionate is reviewed and contrasted with
the earlier studies on inhaled corticosteroids.
The properties of beclomethasone-17,21-dipropionate in man are
investigated. These original studies include an assessment of its topical
anti-inflammatory potency on the skin; the effects following its
administration by inhalation by mouth, intra-nasally and intravenously
on the Hypothalamic-Pituitary-Adrenal (H. P. A. ) axis, together with an
investigation of its absorption, and metabolic fate after oral and intravenous
administration are described. The effects of beclomethasone-l7,2l0-dipropionate
upon circulating white blood cells and fasting blood sugar
levels have also been investigated.
Particular attention has been paid to describing and reviewing the
evidence in animals and in man concerned with potential toxic effects on the
tissues of the respiratory tract. The incidence of bacterial infection in
the lungs of patients treated with beclomethasone-17,21-dipropionate has
also been investigated. Increased colonisation of the oro-phaxynx with
candida albicans, and, less frequently, clinical candidiasis is a complication
of treatment with beclomethasone-17,21-dipropionate. This,
together with possible predisposing factors is assessed.
It is concluded : one, that high topical activity together with lower
systemic activity and metabolic inactivation of the swallowed portion of
beclomethasone-17,2l-dipropionate are the likely reasons why this corticosteroid,
in the doses employed, controls bronchial asthma in most patients
without causing important glucocorticoid. side effects. And two, although
no clinical or experimental evidence exists at present to suggest that this
drug is exerting any deleterious effect on the tissues of the respiratory
tract, this cannot be excluded and continued vigilance is necessary.
Oro-pharyngeal candidiasis is a complication of this treatment, but, at
present, the advantages to the patient of reduced or no oral dosage with
corticosteroids, outweighs the disadvantages of candidiasis, because this
does not occur invariably, it is frequently symptomless, easily treated and
has only occurred superficially
Kernel Ellipsoidal Trimming
Ellipsoid estimation is an issue of primary importance in many practical areas such as control, system identification, visual/audio tracking, experimental design, data mining, robust statistics and novelty/outlier detection. This paper presents a new method of kernel information matrix ellipsoid estimation (KIMEE) that finds an ellipsoid in a kernel defined feature space based on a centered information matrix. Although the method is very general and can be applied to many of the aforementioned problems, the main focus in this paper is the problem of novelty or outlier detection associated with fault detection. A simple iterative algorithm based on Titterington's minimum volume ellipsoid method is proposed for practical implementation. The KIMEE method demonstrates very good performance on a set of real-life and simulated datasets compared with support vector machine methods
Missing energy in black hole production and decay at the Large Hadron Collider
Black holes could be produced at the Large Hadron Collider in TeV-scale
gravity scenarios. We discuss missing energy mechanisms in black hole
production and decay in large extra-dimensional models. In particular, we
examine how graviton emission into the bulk could give the black hole enough
recoil to leave the brane. Such a perturbation would cause an abrupt
termination in Hawking emission and result in large missing-energy signatures.Comment: addressed reviewer comments and updated reference
`NMR Crystallization': in-situ NMR techniques for time-resolved monitoring of crystallization processes
Solid-state NMR spectroscopy is a well-established and versatile technique for studying structural and dynamic properties of solids, and there is considerable potential to exploit the power and versatility of solid-state NMR for in-situ studies of chemical processes. However, a number of technical challenges are associated with adapting this technique for in-situ studies, depending on the process of interest. Recently, an in-situ solid-state NMR strategy for monitoring the evolution of crystallization processes has been developed and has proven to be a promising approach for identifying the sequence of distinct solid forms present as a function of time during crystallization from solution, and for the discovery of new polymorphs. The latest development of this technique, called “CLASSIC” NMR, allows simultaneous measurement of both liquid-state and solid-state NMR spectra as a function of time, thus yielding complementary information on the evolution of both the liquid phase and the solid phase during crystallization from solution. This article gives an overview of the range of NMR strategies that are currently available for in-situ studies of crystallization processes, with examples of applications that highlight the potential of these strategies to deepen our understanding of crystallization phenomena
Hybridization in bottlenose dolphins—A case study of Tursiops aduncus × T. truncatus hybrids and successful backcross hybridization events
The bottlenose dolphin, genus Tursiops is one of the best studied of all the Cetacea with a minimum of two species widely recognised. Common bottlenose dolphins (T. truncatus), are the cetacean species most frequently held in captivity and are known to hybridize with species from at least 6 different genera. In this study, we document several intra-generic hybridization events between T. truncatus and T. aduncus held in captivity. We demonstrate that the F1 hybrids are fertile and can backcross producing apparently healthy offspring, thereby showing introgressive inter-specific hybridization within the genus. We document that female F1 hybrids can reach sexual maturity at 4 yr and 3 mo of age, and can become pregnant and give birth before being fully weaned. The information presented has implications for understanding hybrid reticulation among cetacean species and practical implications for captive facilities housing either Tursiops species or hybrids thereof
Signatures of black holes at the LHC
Signatures of black hole events at CERN's Large Hadron Collider are
discussed. Event simulations are carried out with the Fortran Monte Carlo
generator CATFISH. Inelasticity effects, exact field emissivities, color and
charge conservation, corrections to semiclassical black hole evaporation,
gravitational energy loss at formation and possibility of a black hole remnant
are included in the analysis.Comment: 13 pages, 7 figure
Superconductivity in the two dimensional Hubbard Model.
Quasiparticle bands of the two-dimensional Hubbard model are calculated using
the Roth two-pole approximation to the one particle Green's function. Excellent
agreement is obtained with recent Monte Carlo calculations, including an
anomalous volume of the Fermi surface near half-filling, which can possibly be
explained in terms of a breakdown of Fermi liquid theory. The calculated bands
are very flat around the (pi,0) points of the Brillouin zone in agreement with
photoemission measurements of cuprate superconductors. With doping there is a
shift in spectral weight from the upper band to the lower band. The Roth method
is extended to deal with superconductivity within a four-pole approximation
allowing electron-hole mixing. It is shown that triplet p-wave pairing never
occurs. Singlet d_{x^2-y^2}-wave pairing is strongly favoured and optimal
doping occurs when the van Hove singularity, corresponding to the flat band
part, lies at the Fermi level. Nearest neighbour antiferromagnetic correlations
play an important role in flattening the bands near the Fermi level and in
favouring superconductivity. However the mechanism for superconductivity is a
local one, in contrast to spin fluctuation exchange models. For reasonable
values of the hopping parameter the transition temperature T_c is in the range
10-100K. The optimum doping delta_c lies between 0.14 and 0.25, depending on
the ratio U/t. The gap equation has a BCS-like form and (2*Delta_{max})/(kT_c)
~ 4.Comment: REVTeX, 35 pages, including 19 PostScript figures numbered 1a to 11.
Uses epsf.sty (included). Everything in uuencoded gz-compressed .tar file,
(self-unpacking, see header). Submitted to Phys. Rev. B (24-2-95
Discrimination, labour markets and the Labour Market Prospects of Older Workers: What Can a Legal Case Teach us?
As governments become increasingly concerned about the fiscal implications of the ageing population, labour market policies have sought to encourage mature workers to remain in the labour force. The ‘human capital’ discourses motivating these policies rest on the assumption that older workers armed with motivation and vocational skills will be able to return to fulfilling work. This paper uses the post-redundancy recruitment experiences of former Ansett Airlines
flight attendants to develop a critique of these expectations. It suggests that policies to increase
older workers’ labour market participation will not succeed while persistent socially constructed age- and gender- typing shape labour demand. The conclusion argues for policies sensitive to the institutional structures that shape employer preferences, the competitive rationality of
discriminatory practices, and the irresolvable tension between workers’ human rights and employers’ property rights
In-situ velocity imaging of ultracold atoms using slow--light
The optical response of a moving medium suitably driven into a slow-light
propagation regime strongly depends on its velocity. This effect can be used to
devise a novel scheme for imaging ultraslow velocity fields. The scheme turns
out to be particularly amenable to study in-situ the dynamics of collective and
topological excitations of a trapped Bose-Einstein condensate. We illustrate
the advantages of using slow-light imaging specifically for sloshing
oscillations and bent vortices in a stirred condensate
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