Piezo-modulated active grating for selecting X-ray pulses separated by one nanosecond.

We present a novel method of temporal modulation of X-ray radiation for time resolved experiments. To control the intensity of the X-ray beam, the Bragg reflection of a piezoelectric crystal is modified using comb-shaped electrodes deposited on the crystal surface. Voltage applied to the electrodes induces a periodic deformation of the crystal that acts as a diffraction grating, splitting the original Bragg reflection into several satellites. A pulse of X-rays can be created by rapidly switching the voltage on and off. In our prototype device the duty cycle was limited to ∼1 ns by the driving electronics. The prototype can be used to generate X-ray pulses from a continuous source. It can also be electrically correlated to a synchrotron light source and be activated to transmit only selected synchrotron pulses. Since the device operates in a non-resonant mode, different activation patterns and pulse durations can be achieved.

[The possibilities of adaptation of patients with multiple sclerosis: the results of clinical and psychological study].

A complex clinical and psychological examination of three groups of patients with stable neurological deficit (113 subjects, 77 men and 76 women, aged from 19 to 67 years) included those with multiple sclerosis (MS), chronic cerebral vascular disorders and chronic dorsopathy with illness duration 5-7 years has been carried out. Neuropsychological status and quality of life were assessed using the following tests: Medical Outcomes Study Short Form 36 Health Survey (SF-36); the method of E.B. Fantalova "Level of Ratio of "Values" to "Availability" in Different Life Spheres", Integrative Anxiety Test, Manual for the Constructive Thinking Inventory, Coping test (Lazarus), Beck depression scale. In total, 42 traits on 6 tests have been studied. The study was conducted before and after treatment (21 +/- 2 days). The results revealed that patients with chronic neurological disorders, in particular with MS, often had subclinical depression, which negatively influenced the disease course, and needed treatment. A high level of anxiety was found in MS patients that was related to situational social defensive reaction. Low ability to positive reevaluation of life situations, one of the causes of anxiety states, was observed in all the groups, especially in MS. In MS patients, their real state was not consistent with their perception of this state. They also were featured by personal superstitious thinking. Most of the patients with MS had a good constructive thinking, preserved ability to emotional and behavioral self-control that indicated favorable prognosis in future complex rehabilitation. After the course of symptomatic vascular and metabolic therapy, with the exception of antidepressants and neuroleptics, the appearances of depression and anxiety as well as expression of social defensive reactions and situational phobic component of anxiety were decreased that suggested the necessity of inclusion of individual psychotherapy as a part the complex rehabilitation therapy.