1,238 research outputs found
THE DAMPING OF DIFFERENTIAL ROTATION IN THE CORES OF NEUTRON STARS
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75172/1/j.1749-6632.1977.tb37070.x.pd
Photodynamic Therapy of Necrobiosis Lipoidica - A Multicenter Study of 18 Patients
Background: Necrobiosis lipoidica (NL) is a granulomatous skin disease of unknown origin, and no reliably effective treatment option exists to handle this often disfiguring disease. Recently, a patient with long-lasting NL was reported to be cured by topical photodynamic therapy (PDT). Objective: To evaluate the overall potential of PDT in the treatment of NL on the lower legs. Methods: Retrospective study of 18 patients (aged 16 - 62 years) from 3 European university departments of dermatology treated with PDT for NL. Methyl aminolevulinate or 5-aminolevulinic acid were used as topically applied photosensitizers. Illumination followed with red light-emitting diode light. Results: Complete response was seen in 1/18 patients after 9 PDT cycles, and partial response in 6/18 patients (2 - 14 PDT cycles) giving an overall response rate of 39% (7/18). Conclusion: Although almost 40% of the cases showed some degree of response, PDT cannot currently be recommended as first-line therapy of NL. Subpopulations of therapy-resistant NL patients may, however, benefit from PDT. Copyright (C) 2008 S. Karger AG, Base
Analytic Solution of the Pion-Laser Model
Brooding over bosons, wave packets and Bose - Einstein correlations, we find
that a generalization of the pion-laser model for the case of overlapping
wave-packets is analytically solvable with complete n-particle symmetrization.
The effective radius parameter of the two-particle correlation function is
reduced for low values and enlargened for high values of the mean momentum in
the rare gas limiting case, as compared to the case when multi-particle
symmetrization effects are neglected.
These results explicitly depend on the multiplicity, providing a theoretical
basis for event-by-event analysis of high energy heavy ion reactions.Comment: LaTeX, ReVTeX 3.1, 7 pages, uses 1 eps figure and epsfig.sty
(shortened version
Measurement and monitoring of electrocardiogram belt tension in premature infants for assessment of respiratory function
Background: Monitoring of the electrocardiogram (ECG) in premature infants with conventional adhesive-backed electrodes can harm their sensitive skin. Use of an electrode belt prevents skin irritation, but the effect of belt pressure on respiratory function is unknown. A strain gauge sensor is described which measures applied belt tension. Method: The device frame was comprised of an aluminum housing and slide to minimize the device weight. Velcro tabs connected housing and slide to opposite tabs located at the electrode belt ends. The slide was connected to a leaf spring, to which were bonded two piezoresistive transducers in a half-bridge circuit configuration. The device was tested for linearity and calibrated. The effect on infant respiratory function of constant belt tension in the normal range (30 g–90 g) was determined. Results: The mechanical response to a step input was second order (f_n = 401 Hz, ζ = 0.08). The relationship between applied tension and output voltage was linear in the range 25–225 gm of applied tension (r² = 0.99). Measured device sensitivity was 2.18 mV/gm tension using a 5 V bridge excitation voltage. When belt tension was increased in the normal range from 30 gm to 90 gm, there was no significant change in heart rate and most respiratory functions during monitoring. At an intermediate level of tension of 50 gm, pulmonary resistance and work of breathing significantly decreased. Conclusion: The mechanical and electrical design of a device for monitoring electrocardiogram electrode belt tension is described. Within the typical range of application tension, cardiovascular and respiratory function are not substantially negatively affected by electrode belt force
11 beta-hydroxysteroid dehydrogenase type 1 regulates glucocorticoid-induced insulin resistance in skeletal muscle
OBJECTIVE: Glucocorticoid excess is characterized by increased adiposity, skeletal myopathy, and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts cortisone (11-dehydrocorticosterone in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning glucocorticoid-induced insulin resistance in skeletal muscle and indentify how 11beta-HSD1 inhibitors improve insulin sensitivity. \ud
RESEARCH DESIGN AND METHODS: Rodent and human cell cultures, whole-tissue explants, and animal models were used to determine the impact of glucocorticoids and selective 11beta-HSD1 inhibition upon insulin signaling and action. \ud
RESULTS: Dexamethasone decreased insulin-stimulated glucose uptake, decreased IRS1 mRNA and protein expression, and increased inactivating pSer insulin receptor substrate (IRS)-1. 11beta-HSD1 activity and expression were observed in human and rodent myotubes and muscle explants. Activity was predominantly oxo-reductase, generating active glucocorticoid. A1 (selective 11beta-HSD1 inhibitor) abolished enzyme activity and blocked the increase in pSer IRS1 and reduction in total IRS1 protein after treatment with 11DHC but not corticosterone. In C57Bl6/J mice, the selective 11beta-HSD1 inhibitor, A2, decreased fasting blood glucose levels and improved insulin sensitivity. In KK mice treated with A2, skeletal muscle pSer IRS1 decreased and pThr Akt/PKB increased. In addition, A2 decreased both lipogenic and lipolytic gene expression.\ud
CONCLUSIONS: Prereceptor facilitation of glucocorticoid action via 11beta-HSD1 increases pSer IRS1 and may be crucial in mediating insulin resistance in skeletal muscle. Selective 11beta-HSD1 inhibition decreases pSer IRS1, increases pThr Akt/PKB, and decreases lipogenic and lipolytic gene expression that may represent an important mechanism underpinning their insulin-sensitizing action
ProBiS: a web server for detection of structurally similar protein binding sites
A web server, ProBiS, freely available at http://probis.cmm.ki.si, is presented. This provides access to the program ProBiS (Protein Binding Sites), which detects protein binding sites based on local structural alignments. Detailed instructions and user guidelines for use of ProBiS are available at the server under ‘HELP’ and selected examples are provided under ‘EXAMPLES’
A new limit on scalar and vector contributions to gravity
Macroscopic effects of theories of quantum gravity containing scalar, vector, and tensor component sin proportions CS:CV:CT are considered. Assuming zero mass fields, the classical tests of general relativity are found to imply, to 90% confidence, CT = 1 +/- 0.00 3 and | CV - CS |: CS<0.12. These results, whichare independent of any assumption about differences between matter-matter and matter-antimatter interactions, place meaningful constraints on local supersymmetric theories of gravity.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28011/1/0000447.pd
Can galactic halos be made of baryons?
Several arguments are presented indicating that the apparently non-luminous matter forming massive halos of spiral galaxies is not baryonic. There are difficulties with a halo dominated by gas, snowballs, dust and rocks, jupiters, low mass stars, dead stars and neutron stars. Also, halos may not be composed of black holes unless they are either extremely efficiently accreting or primordial. Consequently, it appears that a significant fraction of the universe may be in the form of massive neutrinos, gravitinos, monopoles, etc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25181/1/0000620.pd
Clan Structure Analysis and Rapidity Gap Probability
Clan structure analysis in rapidity intervals is generalized from negative
binomial multiplicity distribution to the wide class of compound Poisson
distributions. The link of generalized clan structure analysis with correlation
functions is also established. These theoretical results are then applied to
minimum bias events and evidentiate new interesting features, which can be
inspiring and useful in order to discuss data on rapidity gap probability at
TEVATRON and HERA.Comment: (14 pages in Plain TeX plus 5 Postscript Figures, all compressed via
uufiles) DFTT 28/9
Partition Functions in Statistical Mechanics, Symmetric Functions, and Group Representations
Partition functions for non-interacting particles are known to be symmetric
functions. It is shown that powerful group-theoretical techniques can be used
not only to derive these relationships, but also to significantly simplify
calculation of the partition functions for particles that carry internal
quantum numbers. The partition function is shown to be a sum of one or more
group characters. The utility of character expansions in calculating the
partition functions is explored. Several examples are given to illustrate these
techniques.Comment: 16 pages of RevTe
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