10 research outputs found
Subthreshold phonon generation in an optomechanical system with an exceptional point
A phonon laser based on an optomechanical system consisting of two optical
modes interacting with each other via a phononic mode is considered. An
external wave exciting one of the optical modes plays a role of the pumping. It
is shown that at some amplitude of the external wave an exceptional point
exists. When the external wave amplitude is less than one corresponding to the
exceptional point, the splitting of the eigenfrequencies takes place. It is
demonstrated that in this case, the periodic modulation of the external wave
amplitude can result in simultaneous generation of photons and phonons even
below the threshold of optomechanical instability
Hard excitation mode of system with optomechanical instability
System with strong photon-phonon interaction and optomechanical instability
are perspective for generation of coherent phonons and photons. Typically,
above the threshold of optomechanical instability, the photon intensity
increases linearly with pumping. We demonstrate that in such systems, it is
possible to achieve hard mode of excitation when jump increase in the photon
intensity takes place. We derive the analytical expression determining
conditions for such a jump increase. We demonstrate that the hard excitation
mode in system with optomechanical instability arises due to an additional
phase condition for the existence of a nonzero solution. The discovered hard
excitation mode paves the way for creation highly sensitive sensors and optical
transistors
Peculiarities of synaptic vesicle recycling in frog and mouse motor nerve terminals
Using electrophysiology and fluorescence microscopy with dye FM 1-43, a comparative study of peculiarities of neurotransmitter secretion, synaptic vesicle exo-endocytosis and recycling has been carried out in nerve terminals (NT) of the skin-sternal muscle of the frog Rana ridibunda and of the white mouse diaphragm muscle during a long-term high-frequency stimulation (20 imp/s). The obtained data have allowed identifying three synaptic vesicle pools and two recycling ways in the motor NT. In the frog NT, the long-term high-frequency stimulation induced consecutive expenditure of the pool ready to release, the mobilizational, and reserve vesicle pools. The exocytosis rate exceeded markedly the endocytosis rate; the slow synaptic vesicle recycling with replenishment of the reserve pool was predominant. In the mouse NT, only the vesicles of the ready to release and the mobilizational pools, which are replenished predominantly by fast recycling, were exocytosed. The exo- and endocytosis occurred practically in parallel, while vesicles of the reserve pool did not participate in the neurotransmitter secretion. It is suggested that evolution of the motor NT from the poikilothermal to homoiothermal animals went by the way of a decrease of the vesicle pool size, the more economic expenditure and the more effective reuse of synaptic vesicles owing to the high rates of endocytosis and recycling. These peculiarities can provide in NT of homoiothermal animals a long maintenance of neurotransmitter secretion at the steady and sufficiently high level to preserve reliability of synaptic transmission in the process of the high-frequency activity. © 2008 Pleiades Publishing, Ltd
ПЕРВЫЙ ОПЫТ ЛЕЧЕНИЯ НЕОПЕРАБЕЛЬНОГО ГЕПАТОЦЕЛЛЮЛЯРНОГО РАКА ПЕЧЕНИ ПУТЕМ ХИМИОЭМБОЛИЗАЦИИ ПЕЧЕНОЧНОЙ АРТЕРИИ МИКРОСФЕРАМИ
In the article the method of treatment of unresectable hepatocellular carcinoma has shown. The method is based on the tumor vessels chemoembolization saturating areas with Doksirubitsin mkr Terumo Biocompatibles DCBead 100-300. This technique allows to stop further spread of tumor and to achieve the regress.В статье освещена методика лечения нерезектабельного гепатоцеллюлярного рака. Метод основан на химиоэмболизации сосудов опухоли насыщаемыми доксирубицином сферами DCBead 100-300 мкр Terumo Biocompatibles. Данная методика позволяет приостановить дальнейшее распространение опухолевого процесса и добиться регресса.
Peculiarities of synaptic vesicle recycling in frog and mouse motor nerve terminals
Using electrophysiology and fluorescence microscopy with dye FM 1-43, a comparative study of peculiarities of neurotransmitter secretion, synaptic vesicle exo-endocytosis and recycling has been carried out in nerve terminals (NT) of the skin-sternal muscle of the frog Rana ridibunda and of the white mouse diaphragm muscle during a long-term high-frequency stimulation (20 imp/s). The obtained data have allowed identifying three synaptic vesicle pools and two recycling ways in the motor NT. In the frog NT, the long-term high-frequency stimulation induced consecutive expenditure of the pool ready to release, the mobilizational, and reserve vesicle pools. The exocytosis rate exceeded markedly the endocytosis rate; the slow synaptic vesicle recycling with replenishment of the reserve pool was predominant. In the mouse NT, only the vesicles of the ready to release and the mobilizational pools, which are replenished predominantly by fast recycling, were exocytosed. The exo- and endocytosis occurred practically in parallel, while vesicles of the reserve pool did not participate in the neurotransmitter secretion. It is suggested that evolution of the motor NT from the poikilothermal to homoiothermal animals went by the way of a decrease of the vesicle pool size, the more economic expenditure and the more effective reuse of synaptic vesicles owing to the high rates of endocytosis and recycling. These peculiarities can provide in NT of homoiothermal animals a long maintenance of neurotransmitter secretion at the steady and sufficiently high level to preserve reliability of synaptic transmission in the process of the high-frequency activity. © 2008 Pleiades Publishing, Ltd
Peculiarities of synaptic vesicle recycling in frog and mouse motor nerve terminals
Using electrophysiology and fluorescence microscopy with dye FM 1-43, a comparative study of peculiarities of neurotransmitter secretion, synaptic vesicle exo-endocytosis and recycling has been carried out in nerve terminals (NT) of the skin-sternal muscle of the frog Rana ridibunda and of the white mouse diaphragm muscle during a long-term high-frequency stimulation (20 imp/s). The obtained data have allowed identifying three synaptic vesicle pools and two recycling ways in the motor NT. In the frog NT, the long-term high-frequency stimulation induced consecutive expenditure of the pool ready to release, the mobilizational, and reserve vesicle pools. The exocytosis rate exceeded markedly the endocytosis rate; the slow synaptic vesicle recycling with replenishment of the reserve pool was predominant. In the mouse NT, only the vesicles of the ready to release and the mobilizational pools, which are replenished predominantly by fast recycling, were exocytosed. The exo- and endocytosis occurred practically in parallel, while vesicles of the reserve pool did not participate in the neurotransmitter secretion. It is suggested that evolution of the motor NT from the poikilothermal to homoiothermal animals went by the way of a decrease of the vesicle pool size, the more economic expenditure and the more effective reuse of synaptic vesicles owing to the high rates of endocytosis and recycling. These peculiarities can provide in NT of homoiothermal animals a long maintenance of neurotransmitter secretion at the steady and sufficiently high level to preserve reliability of synaptic transmission in the process of the high-frequency activity. © 2008 Pleiades Publishing, Ltd
Peculiarities of synaptic vesicle recycling in frog and mouse motor nerve terminals
Using electrophysiology and fluorescence microscopy with dye FM 1-43, a comparative study of peculiarities of neurotransmitter secretion, synaptic vesicle exo-endocytosis and recycling has been carried out in nerve terminals (NT) of the skin-sternal muscle of the frog Rana ridibunda and of the white mouse diaphragm muscle during a long-term high-frequency stimulation (20 imp/s). The obtained data have allowed identifying three synaptic vesicle pools and two recycling ways in the motor NT. In the frog NT, the long-term high-frequency stimulation induced consecutive expenditure of the pool ready to release, the mobilizational, and reserve vesicle pools. The exocytosis rate exceeded markedly the endocytosis rate; the slow synaptic vesicle recycling with replenishment of the reserve pool was predominant. In the mouse NT, only the vesicles of the ready to release and the mobilizational pools, which are replenished predominantly by fast recycling, were exocytosed. The exo- and endocytosis occurred practically in parallel, while vesicles of the reserve pool did not participate in the neurotransmitter secretion. It is suggested that evolution of the motor NT from the poikilothermal to homoiothermal animals went by the way of a decrease of the vesicle pool size, the more economic expenditure and the more effective reuse of synaptic vesicles owing to the high rates of endocytosis and recycling. These peculiarities can provide in NT of homoiothermal animals a long maintenance of neurotransmitter secretion at the steady and sufficiently high level to preserve reliability of synaptic transmission in the process of the high-frequency activity. © 2008 Pleiades Publishing, Ltd
CASE OF TREATMENT OF UNRESECTABLE HEPATOCELLULAR CARCINOMA OF THE LIVER THROUGH THE HEPATIC ARTERY CHEMOEMBOLIZATION M
In the article the method of treatment of unresectable hepatocellular carcinoma has shown. The method is based on the tumor vessels chemoembolization saturating areas with Doksirubitsin mkr Terumo Biocompatibles DCBead 100-300. This technique allows to stop further spread of tumor and to achieve the regress
Treatment of erectile dysfunction in patients after kidney transplantation depending on type of vascular anastomosis: results of short-term follow up study
Introduction. The prevalence of erectile dysfunction in men with chronic kidney disease stage V is from 60 to 80%. At the same time, the prevalence of erectile dysfunction in patients after kidney transplantation remains high at up to 60%. One of the possible causes of erectile dysfunction after kidney transplantation is considered a decrease in arterial inflow to the cavernous bodies of the penis.Objectives. Тo evaluate the results of treatment of ED in patients after KT, depending on the vascular anastomosis.Materials and methods. 84 patients with a functioning kidney after transplantation were examined. All patients were divided into 3 groups: Group I – 38 patients undergoing KT with arterial vascular anastomosis with an internal iliac artery; Group II – 46 patients undergoing kidney transplantation with arterial vascular anastomosis to external iliac artery; Group III – 35 healthy volunteers (control group) with no history of urological diseases or surgical interventions on the pelvic organs. International Index of Erectile Function Index (IIEF-5) was used to assess erectile function. An ultrasound study with dopplerography of the penile arteries was performed before and after intracavernous pharmacological stress. For treating patients with erectile dysfunction after kidney transplantation were used PDE-5 inhibitors (Tadalafil® 5 mg daily for 3 months, then at a dose of 20 mg “on demand”), a special set of exercises for the muscles of the pelvic floor, vacuum therapy and physiotherapy with the device “Androgyne”.Results. Significant erectile function disorders were detected in 26 (68.4%) patients of group I, and in 31 (73.9%) patients of group II, according to data from the IIEF-5 questionnaire. Group I 27 (71.1%) patients were satisfied with sex life, group II – 39 (84.8%) by the end of the year. According to the Doppler ultrasound, after 12 months in patients of group I, the maximum systolic velocity of blood flow in the right and left cavernous artery of the penis was 25.0 ± 3.44 cm / s and 33.0 ± 3.56 cm / s, respectively. The difference in arterial inflow of 8 cm / s indicates a pronounced arterial perfusion of the penis in group I patients. At the same time, in patients of group II, the maximum systolic velocity was significantly higher than in group I and amounted to 40.1 ± 2.66 cm/s and 40.0 ± 2.77 cm/s, respectively.Conclusion. The data obtained indicate a decrease in the arterial inflow to the penis along the right cavernous artery in patients from group I, who underwent an arterial vascular anastomosis with an internal iliac artery during kidney transplantation