31 research outputs found
Phonons in random alloys: the itinerant coherent-potential approximation
We present the itinerant coherent-potential approximation(ICPA), an analytic,
translationally invariant and tractable form of augmented-space-based,
multiple-scattering theory in a single-site approximation for harmonic phonons
in realistic random binary alloys with mass and force-constant disorder.
We provide expressions for quantities needed for comparison with experimental
structure factors such as partial and average spectral functions and derive the
sum rules associated with them. Numerical results are presented for Ni_{55}
Pd_{45} and Ni_{50} Pt_{50} alloys which serve as test cases, the former for
weak force-constant disorder and the latter for strong. We present results on
dispersion curves and disorder-induced widths. Direct comparisons with the
single-site coherent potential approximation(CPA) and experiment are made which
provide insight into the physics of force-constant changes in random alloys.
The CPA accounts well for the weak force-constant disorder case but fails for
strong force-constant disorder where the ICPA succeeds.Comment: 19 pages, 12 eps figures, uses RevTex
Defects in Regulation of Local Immune Responses Resulting in Atherosclerosis
Atherosclerosis is nowadays generally accepted as an inflammatory disease
but the mechanism of its origin and development have not yet been fully clarified.
The present review focuses on the role of the local immune system as one of the
key players in the pathogenesis of the complex process. Its part represented by
vascular-associated lymphoid tissue (VALT) within the arterial wall participates
directly in the vascular wall's homeostatis. Its inordinate activation during
ontogenic development of an individual, this formerly defensive and physiologic
mechanism transform into a pathological process resulting in an impairing
inflammation. Hsp60, CRP and oxidized or otherwise modified LDL are serious
candidates for triggering these pathological changes. The principal role is played
by anti-Hsp60 antibodies and by shear stress originating on the surface of
endothelium due to blood flow. The experimental and clinical data
supporting this immunological hypothesis of atherosclerosis are discussed
Therapeutic Management of Primary Immunodeficiency in Older Patients
Primary immunodeficiency disease (PID) has traditionally been viewed as a group of illnesses seen in the paediatric age group. New advances in diagnosis and treatment have led to an increase in the number of elderly PID patients. However, there is lack of research evidence on which to base clinical management in this group of patients. Management decisions often have to be based therefore on extrapolations from other patient cohorts or from younger patients. Data from the European Society for Immunodeficiencies demonstrates that the vast majority of elderly patients suffer from predominantly antibody deficiency syndromes. We review the management of PID disease in the elderly, with a focus on antibody deficiency disease
Engaging through disaster: reaching new audiences with SMASHfestUK
Reflecting on the Science and Technology Facilities Council support of SMASHfestUK's approach to developing new methods for, and delivering new approaches to, widening participation in public engagement and increasing diversity in STEM education and careers