REACTOR FUEL WASTE DISPOSAL PROJECT DEVELOPMENT OF DESIGN PRINCIPLE FOR DISPOSAL OF REACTOR FUEL WASTE INTO UNDERGROUND SALT CAVITIES

Waste disposal in underground salt cavities is considered. Theoretical Investigations for spherical and cylindrical cavities included analysis of elastic stress, thermal stress, and stress redistribution due to the development of a plastic zone around the cavity. The problems of temperature distribution and accompanying thermal stress, due to heat emission from the waste, were also studied. The reduction of the cavity volume, the development of the plastic zone, and the resulting stress redistribution around the cavity are presented as functions of cavity depth, internal pressure of cavity, strenzth of salt, and cavity teraperature rise. It is shown that a salt cavity can be designed such that it is structurally stable as a storage container assuming a chemical equilibrium can be established between the liquid waste and salt. (W.D.M.

Maintenance deep transcranial magnetic stimulation sessions are associated with reduced depressive relapses in patients with unipolar or bipolar depression

Introduction: Deep transcranial magnetic stimulation (dTMS) is a new form of TMS allowing safe stimulation of deep brain regions. The objective of this preliminary study was to assess the role of dTMS maintenance sessions in protecting patients with bipolar disorder (BD) or recurrent major depressive disorder (MDD) from developing depressive or manic relapses in a 12-month follow-up period. Methods: Twenty-four drug-resistant patients with a current depressive episode and a diagnosis of MDD or BD have been enrolled in the study. All the participants underwent daily dTMS sessions for 4 weeks. One group (maintenance - M group) received additional maintenance dTMS sessions weekly or twice a week. Results: After the first dTMS cycle, a significant reduction of Hamilton Depression Rating Scale (HDRS) scores was observed in all participants. Subsequently, the HDRS mean scores did not significantly change over time in the M group, while it significantly increased in the non-M-group after 6 and 12 months. Discussion: This study confirms previous evidence of a positive therapeutic effect of dTMS on depressive symptoms and suggests that, after recovery from acute episodes, maintenance dTMS sessions may be helpful in maintaining euthymia in a 12-month follow-up period

Mitochondrial myopathy and comorbid major depressive disorder. effectiveness of dTMS on gait and mood symptoms

Background: Mitochondrial myopathies (MMs) often present with leukoencephalopathy and psychiatric symptoms, which do not respond to or worsen with psychiatric drugs. Case report: A 67-year-old woman with a 10-year history of probable chronic progressive external ophthalmoplegia, an MM, had drug-resistant, anxious-depressive symptoms. Since she had never had seizures, we proposed 20 sessions of deep transcranial magnetic stimulation (dTMS) for her depression. Surprisingly, besides the expected improvement of depression, we observed marked improvement of movement disorder that lasted as long as the patient was undergoing dTMS. She also improved her performance on neuropsychological tests of executive function and cognitive speed. Depressive symptom improvement was persistent, while anxiety symptoms recurred after the end of the sessions. Conclusions: dTMSmay be an alternative antidepressant strategy in patients withMMs, provided that they are free from seizures. The mechanism of improvement of motor disturbance may relate to dorsolateral prefrontal cortex stimulation and improved executive function and needs further investigation

STRUCTURAL NEUROIMAGING IN PATIENTS WITH PANIC DISORDER: FINDINGS AND LIMITATIONS OF RECENT STUDIES

Background: Panic disorder, a relatively common anxiety disorder, is often associated to agoraphobia and may be disabling. Its neurobiological underpinnings are unknown, despite the proliferation of models and hypotheses concerning it; investigating its correlates could provide the means for better understanding its pathophysiology. Recent structural neuroimaging techniques may contribute to the identification of possible brain morphological alterations that could be possibly related to the clinical expression of panic disorder. Methods: Through careful major database searches, using terms keen to panic, agoraphobia, structural magnetic neuroimaging and the like, we identified papers published in peer-review journals and reporting data on the brain structure of patients with panic disorder. Included papers were used comparatively to speculate about the nature of reported brain structural alterations. Results: Anxiety, which is the core feature of the disorder, correlates with the function of the amygdala, which showed a smaller volume in patients, as compared to healthy subjects. Data also showed a volumetric decrease of the anterior cingulate along with increased fractional anisotropy, and increase of some brainstem nuclei, particularly of the rostral pons. Other structures with reported volumetric correlates of panic disorder are the hippocampus and the parahippocampal cortices, the insula, the putamen, and the pituitary gland. Volumetric changes in the anterior cingulate, frontal, orbitofrontal, insular, and temporal cortices have also been described in structural neuroimaging studies. Major methodological limitations are considered in context. Conclusions: Several data point to the existence of structural neuroanatomical alterations in panic disorder, consisting in significant volumetric reductions or increases in different brain areas. White matter alterations were shown also in the only diffusion tensor imaging study performed to date. Available data do not allow us to conclude about the possible progression of these alterations

Electromagnetic Dissociation as a Tool for Nuclear Structure and Astrophysics

Coulomb dissociation is an especially simple and important reaction mechanism. Since the perturbation due to the electric field of the (target) nucleus is exactly known, firm conclusions can be drawn from such measurements. Electromagnetic matrixelements and astrophysical S-factors for radiative capture processes can be extracted from experiments. We describe the basic elements of the theory of nonrelativistic and relativistic electromagnetic excitation with heavy ions. This is contrasted to electromagnetic excitation with leptons (electrons), with their small electric charge and the absence of strong interactions. We discuss various approaches to the study of higher order electromagnetic effects and how these effects depend on the basic parameters of the experiment. The dissociation of neutron halo nuclei is studied in a zero range model using analytical methods. We also review ways how to treat nuclear interactions, show their characteristics and how to avoid them (as far as possible). We review the experimental results from a theoretical point of view. Of special interest for nuclear structure physics is the appearence of low lying electric dipole strength in neutron rich nuclei. Applications of Coulomb dissociation to some selected radiative capture reactions relevant for nuclear astrophysics are discussed. The Coulomb dissociation of 8B is relevant for the solar neutrino problem. The potential of the method especially for future investigations of (medium) heavy exotic nuclei for nuclear structure and astrophysics is explored. We conclude that the Coulomb dissociation mechanism is theoretically well understood, the potential difficulties are identified and can be taken care of. Many interesting experiments have been done in this field and many more are expected in the future.Comment: review article accepted for publication in "Prog. in Part. and Nucl. Physics", 75 pages, 31 figure