Adiabatic condition for nonlinear systems.

The adiabatic approximation is an important concept in quantum mechanics. In linear systems, the adiabatic condition is derived with the help of the instantaneous eigenvalues and eigenstates of the Hamiltonian, a procedure that breaks down in the presence of nonlinearity. Using an explicit example relevant to photoassociation of atoms into diatomic molecules, we demonstrate that the proper way to derive the adiabatic condition for nonlinear mean-field (or classical) systems is through a linearization procedure, using which an analytic adiabatic condition is obtained for the nonlinear model under study.

The impact of auditory cortex activity on characterizing and treating patients with chronic tinnitus--first results from a PET study.

Conclusion: Unilaterally increased metabolic activity within the primary auditory cortex (PAC) represents a robust finding in tinnitus patients. Targeting these hyperactive areas with image-guided low frequency repetitive transcranial magnetic stimulation (rTMS) results in subjective tinnitus reduction. More pronounced activation of the PAC predicted higher resistance to rTMS.

Clinical value of planar and tomographic dual-isotope scintigraphy using 99mTc-methylene diphosphonate and 131I in patients with thyroid cancer.

Purpose: (131)I whole-body scintigraphy is a highly sensitive method for the detection of differentiated thyroid tumours and metastases. However, a lack of anatomical landmarks and the physiological excretion of the tracer complicates the evaluation of the images. Therefore, we determined whether additional bone scintigraphy in combination with (131)I scintigraphy, simultaneously acquired via planar and tomographic techniques, positively contributes to the treatment plan in patients with non-conclusive (131)I images.

Neuronavigated rTMS in a patient with chronic tinnitus. Effects of 4 weeks treatment.

Clinical, neurophysiological and neuroimaging data suggest that chronic tinnitus resembles neuropsychiatric syndromes characterised by focal brain activation. Low frequency repetitive transcranial magnetic stimulation (rTMS) has been proposed as an efficient method in treating brain hyperexcitability disorders. In one patient suffering from chronic tinnitus, [18F]deoxyglucose PET revealed increased metabolic activity in a circumscript area of the left primary auditory cortex (PAC).