Biofeedback treatment of proctogenic constipation in adults

Aim of investigation. To study efficacy of biological feedback treatment (BFT) at proctogenic constipation in adult patients.Material and methods. Overall 30 patients with proctogenic constipation and dyssynergia of pelvic floor muscles i.e. spasm of puborectalis muscle were included in original study and treated by BFT method. Mean age of patients was 31,2±9,8 year, men to women ratio was 1:5.Results. During treatment decrease in difficulty to defecate according to Rome-III criteria was observed in 22 (73,3%) patients. The other 8 (26,7%) patients demonstrated no improvement. According to subjective assessment of rectal evacuatory function by questioning before and after BFT statistically significant reduction of proctogenic constipation symptoms was revealed. By the data of objective investigation (profilometry and electromyography) signs of dyssynergia of pelvic floor muscles were revealed in no patient.Conclusions. The biological feedback is effective treatment method for proctogenic constipation, allowing to reduce symptoms in 73,3% of patients and to correct dyssynergia of pelvic floor muscles in all cases

Role of doped layers in dephasing of 2D electrons in quantum well structures

The temperature and gate voltage dependences of the phase breaking time are studied experimentally in GaAs/InGaAs heterostructures with single quantum well. It is shown that appearance of states at the Fermi energy in the doped layers leads to a significant decrease of the phase breaking time of the carriers in quantum well and to saturation of the phase breaking time at low temperature.Comment: 4 pages, 6 figure

Quantum corrections to conductivity: from weak to strong localization

Results of detailed investigations of the conductivity and Hall effect in gated single quantum well GaAs/InGaAs/GaAs heterostructures with two-dimensional electron gas are presented. A successive analysis of the data has shown that the conductivity is diffusive for $k_F l=25-2$ and behaves like diffusive one for $k_F l=2-0.5$ down to the temperature T=0.4 K. It has been therewith found that the quantum corrections are not small at low temperature when $k_F l\simeq 1$. They are close in magnitude to the Drude conductivity so that the conductivity $\sigma$ becomes significantly less than $e^{2}/h$ (the minimal $\sigma$ value achieved in our experiment is about $3\times 10^{-8}\Omega^{-1}$ at $k_Fl\simeq 0.5$ and $T=0.46$ K). We conclude that the temperature and magnetic field dependences of conductivity in whole $k_Fl$ range are due to changes of quantum corrections.Comment: RevTex 4.0, 10 figures, 7 two-column page

Pattern of morphological and neurophysiologic changes in women with the syndrome of the descending perineum

Aim of investigation. To determine morphological rating of connective tissue structures of perineum and detect neurophysiologic disorders of pelvic floor in patients with the descending perineum syndrome (DPS).Material and methods. Original study included 39 women with DPS in the age of 21 to 68 years, with clinical and instrumental signs of descending perineum syndrome. Comparative study of pattern of connective tissue structures in 14 DPS patients that constituted main group and in 10 women without clinical and instrumental DPS signs (control group) was carried out. In 27 DPS patients conductivity of genitofemoral nerve, F-wave latency and anal sphincter motor activity potential were investigated.Results. In main group changes of collagen skeleton of perineal skin, pelvic ligaments, vaginal walls with significant dissociation, disorganization and breakdown of collagen was revealed that was associated by severe hyperelastosis and lymphostasis in connective tissue structures of perineum. In 88,8% of patients with DPS statistically significant disorder of electric conductivity by genitofemoral nerves, and in 70,4% - severe denervation of reflex arch from sacral region of vertebral column to anal sphincter was revealed.Conclusions. Along with distinct changes of connective tissue structures of perineum, DPS it is characterized by neurophysiologic disorders of pelvic floor registered not only in peripheral innervation zone, but also along the whole reflex arch

Role of Doped Layers in the Dephasing of Two-dimensional Electrons in Quantum-well Structures

The temperature and gate voltage dependences of the phase breaking time are studied experimentally in GaAs/InGaAs heterostructures with a single quantum well. It is shown that appearance of states at the Fermi energy in the doped layers leads to a significant decrease of the phase breaking time of the carriers in the quantum well and to saturation of the phase breaking time at low temperature.This work was supported in part by the RFBR through Grant Nos. 00-02-16215, 01-02-06471, and 01-02-17003, the Program University of Russia through Grant Nos. 990409 and 990425, the CRDF through Grant No. REC-005, and the Russian Program Physics of Solid State Nanostructures