Propagator of a Charged Particle with a Spin in Uniform Magnetic and Perpendicular Electric Fields

We construct an explicit solution of the Cauchy initial value problem for the time-dependent Schroedinger equation for a charged particle with a spin moving in a uniform magnetic field and a perpendicular electric field varying with time. The corresponding Green function (propagator) is given in terms of elementary functions and certain integrals of the fields with a characteristic function, which should be found as an analytic or numerical solution of the equation of motion for the classical oscillator with a time-dependent frequency. We discuss a particular solution of a related nonlinear Schroedinger equation and some special and limiting cases are outlined.Comment: 17 pages, no figure

CD28null CD4 T-cell expansions in autoimmune disease suggest a link with cytomegalovirus infection

Immunosenescence is thought to contribute to the increase of autoimmune diseases in older people. Immunosenescence is often associated with the presence of an expanded population of CD4 T cells lacking expression of CD28 (CD28null). These highly cytotoxic CD4 T cells were isolated from disease-affected tissues in patients with rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, or other chronic inflammatory diseases and their numbers appeared to be linked to disease severity. However, we recently demonstrated that the common herpes virus, cytomegalovirus (CMV), not ageing, is the major driver of this subset of cytotoxic T cells. In this review, we discuss how CMV might potentiate and exacerbate autoimmune disease through the expansion of CD28null CD4 T cells

Fabrication of biosensor arrays via dpn, and detection by surface enhanced resonance raman scattering

There is a growing need for fast reliable biosensor arrays for disease screening. We have used nanostructured plasmonic gold surfaces for the detection of biological species by surface enhanced resonance Raman scattering (SERRS). Careful, directed placement by Dip-pen Nanolithography (DPN) of the biological species or capture chemistry, within the array facilitates efficient read out via ultra fast Raman line mapping. Further, we can transition the serial placement of biological species / capture chemistry to a massively parallel deposition method, and this flexibility is key to enhancing the throughput of these combined techniques by many orders of magnitude. SERRS is an extremely sensitive spectroscopic technique that offers several advantages over conventional fluorescence detection. For example, the high sensitivity of the method allows detection of DNA capture from single plasmonic array "pixels" ~1 µm2 in area. Additionally, the information rich nature of the SERRS spectrum allows multiple levels of detection to be embedded into each pixel, further increasing the information depth of the array. By moving from micro- to nano-scale features, sensor chips can contain up to 105 times more information, dramatically increasing the capacity for disease screening

Possible Horizontal Transfer of the vanB2 Gene among Genetically Diverse Strains of Vancomycin-Resistant Enterococcus faecium in a Korean Hospital

A total of 25 isolates of vanB-containing Enterococcus faecium were recovered from patients in a single Korean hospital over a 20-month period. There were two distinct vanB2 patterns among the 11 pulsed-field gel electrophoresis types; 17 contained the prototype vanB2 and 8 contained a novel vanB2 with a 177-bp deletion in vanY(B). Both vanB2 genes were transmissible in vitro at a mean frequency of 1.1 × 10(−8) transconjugants/donor. These results suggest the horizontal spread of vanB2 is occurring among genetically diverse strains of E. faecium in Korean hospitals