Evidence of Electron Heating by Alpha Particles in JET Deuterium-Tritium Plasmas.

The fusion-born alpha particle heating in magnetically confined fusion machines is a high priority subject for studies. The self-heating of thermonuclear fusion plasma by alpha particles was observed in recent deuterium-tritium (D-T) experiments on the joint European torus. This observation was possible by conducting so-called "afterglow" experiments where transient high fusion yield was achieved with neutral beam injection as the only external heating source, and then termination of the heating at peak performance. This allowed the first direct evidence for electron heating of plasmas by fusion-born alphas to be obtained. Interpretive transport modeling of the relevant D-T and reference deuterium discharges is consistent with the alpha particle heating observation.

[Long-term results and predictors of postoperative outcomes in patients with cauda equina syndrome following degenerative lumbar spine disease]. / Otdalennye rezul'taty i faktory, vliyayushchie na iskhod khirurgicheskogo lecheniya sindroma konskogo khvosta, obuslovlennogo degenerativnym zabolevaniem poyasnichnogo otdela pozvonochnika.

Cauda equina syndrome (CES) associated with acute disc extrusion or spinal stenosis often requires emergency surgery. Analysis of the Pubmed, Medline and eLibrary databases revealed a few studies devoted to long-term postoperative outcomes in patients with CES caused by degenerative spine disease. OBJECTIVE: To evaluate long-term postoperative results and predictors of clinical and neurological outcomes in patients with CES caused by degenerative lumbar spine disease. MATERIAL AND METHODS. D: Ecompressive and decompressive-stabilizing procedures were performed in 211 patients with CES caused by degenerative lumbar spine disease between 2000 and 2020. Long-term clinical parameters were available in 174 patients with mean follow-up period of 7 years. Sixty-eight patients had unsatisfactory postoperative outcomes. We assessed postoperative clinical and neurological outcomes in patients with CES and predictors of these outcomes. RESULTS: We identified the following predictors of clinical and neurological outcomes using binary logistic regression model: period between clinical manifestation and surgery >48 hours, preoperative neurological impairment, spinal canal diameter, surgical procedure, dimension of herniated disc, ASA score and long-term postoperative analgesia with narcotic analgesics. CONCLUSION: Preoperative planning and possible correction of the above-mentioned risk factors will potentially improve postoperative outcomes in patients with CES caused by degenerative lumbar spine disease.

[Comparative analysis of the results of decompressive interventions in elderly patients with cauda equine syndrome caused by lumbar spinal stenosis.]

The aim of the study was to evaluate the results of surgical treatment and the effectiveness of clinical recovery in elderly patients with cauda equina syndrome (CES) caused by degenerative spinal canal stenosis after isolated open and minimally invasive decompression. A retrospective analysis of the results of surgical treatment of 50 patients over 60 years of age who underwent isolated open (n=21) and minimally invasive (n=29) decompressive interventions for CES caused by lumbar spinal stenosis was performed. For comparative analysis, we used the technical features of the intervention, the specificity of postoperative management of patients, clinical parameters, and the number of perioperative complications. As a result, the advantages of minimally invasive isolated decompression compared to open decompression due to a smaller volume of blood loss and duration of hospitalization, low need for postoperative pain relief, a minimum number of perioperative surgical complications, as well as the dynamics of neurological symptoms, better efficiency of clinical recovery of functional state indicators according to ODI and quality life according to SF-36 in the late postoperative period.

Lost alpha Faraday cup foil noise characterization during Joint European Torus plasma post-processing analysis.

Capacitive plasma pickup is a well-known and difficult problem for plasma-facing edge diagnostics. This problem must be addressed to ensure an accurate and robust interpretation of the real signal measurements vs noise. The Faraday cup fast ion loss detector array of the Joint European Torus (JET) is particularly prone to this issue and can be used as a testbed to prototype solutions. The issue of separation and distinction between warranted fast ion signal and electromagnetic plasma noise has traditionally been solved with hardware modifications, but a more versatile post-processing approach is of great interest. This work presents post-processing techniques to characterize the signal noise. While hardware changes and advancements may be limited, the combination with post-processing procedures allows for more rapid and robust analysis of measurements. The characterization of plasma pickup noise is examined for alpha losses in a discharge from JET's tritium campaign. In addition to highlighting the post-processing methodology, the spatial sensitivity of the detector array is also examined, which presents significant advantages for the physical interpretation of fast ion losses.

Accelerated Recovery Program for Patients with Polysegmental Degenerative Lumbar Spine Disease.

The aim of the study was to evaluate the effectiveness of the accelerated recovery program for patients with polysegmental degenerative diseases of the lumbar spine. Materials and Methods: This prospective study included 53 patients who underwent two-level transforaminal interbody fusion in the LII-SI segments. Two groups were identified: in group 1 (n=24), operations were performed using the accelerated recovery program; in group 2 (n=29), open rigid stabilization was used under traditional intravenous anesthesia. The end-point parameters were the number of bed-days spent in the hospital after the operation, the number of perioperative surgical complications and adverse effects of anesthesia, and the number of re-hospitalizations within 90 days. We also recorded the time of patient activation, the level of pain around the operated zone (using a visual analogue scale), and the quality of life in the long-term postoperative period (median 18 months); the latter was assessed using the SF-36 questionnaire (physical and psychological components of health). Results: Patients under the accelerated recovery program were found to have a shorter duration of surgery and anesthesia, less blood loss, lower amounts of injected opioids, faster verticalization, and a reduced period of inpatient treatment (p<0.05 for all parameters). As compared to group 2, patients in group 1 had a lower level of pain in the surgery zone (p<0.05), better long-term indicators of the physical and psychological components of health (p<0.05), a lower number of anesthesia-associated adverse events (p<0.05), and a lower rate of postoperative complications (p<0.05). During the 90-day postoperative observation, four patients of group 2 (13.8%) were urgently referred to a medical institution for additional medical care. Conclusion: The accelerated recovery program for two-level interbody fusion showed its safety and high clinical efficiency in the treatment of patients with polysegmental degenerative diseases of the lumbar spine. The program can be used in any center for spine surgery where effective interaction between polyvalent medical and nursing teams is maintained.

Upgrade and absolute calibration of the JET scintillator-based fast-ion loss detector.

The JET FILD is a scintillator-based Fast-ion Loss Detector optimized to measure fusion-born alpha-particle losses. This work covers its upgrade and absolute calibration in preparation for the following JET DT experiments. A fast scintillator material (TG-Green) has been installed in the JET FILD. A heater jacket is installed around the fiber bundle, responsible for transmitting the light from the scintillator plate, to anneal the fiber obscuring due to neutron damage. The JET FILD has been upgraded with a 1 Mpx camera and 2 MHz photomultiplier data acquisition hardware. Full-orbit simulations give an estimate of the shading effects on the scintillator plate of the first wall structures and provide a synthetic signal of the JET FILD. A detector instrument function enables absolute values of fast-ion losses using calibration factors. The calibration factors are made available in a shot-to-shot basis for the characterized species and energies and with corrections for the diagnostic conditions. The fast acquisition system sets the Nyquist frequency (1 MHz) above the typical mode frequencies (≈102 kHz), thus making it possible to identify MHD-induced fast-ion losses.

[A comparative analysis of clinical efficiency of laser and radiofrequency denervation in patients with primary trigeminal neuralgia]. / Sravnitel'nyi analiz klinicheskoi effektivnosti primeneniya lazernoi i radiochastotnoi denervatsii u patsientov s pervichnoi nevralgiei troinichnogo nerva.

OBJECTIVE: To compare the clinical efficacy of laser and radiofrequency denervation in patients with primary trigeminal neuralgia. MATERIAL AND METHODS: The study included 50 patients with primary trigeminal neuralgia who were operated on by laser (group I, n=25) or radiofrequency denervation (group II, n=25) in the period from 2018 to 2019. To assess the clinical efficacy, we analyzed the dynamics of the pain syndrome level according to the scale of facial pain and the quality of life according to the Short Form Medical Outcomes Study (SF-36), as well as patient satisfaction with the operation according to the Macnab scale, the presence of postoperative surgical complications and adverse effects of anesthesia. RESULTS: In the postoperative period, according to the scale of facial pain, a decrease in its intensity was noted in both study groups (p<0.001). Comparative analysis showed a comparable level of pain in the early postoperative period: at discharge (p=0.43) and 6 months after surgery (p=0.07). At the same time, after 12 months, lower scores on the scale of facial pain were noted in patients of group I (p=0.02). According to SF-36, a significant improvement in the physical and psychological components of health was determined in group I (p<0.001) and group II (p<0.05). Comparison of SF-36 scores in the long-term postoperative period revealed the best indicators in group I (p=0.02 and p=0.01, respectively). Comparative analysis verified a greater subjective satisfaction with the operation in group I, compared with group II (p<0.001). A comparable number of adverse effects of anesthesia was determined in both groups. Comparative analysis revealed a significantly greater number of postoperative surgical complications in group II (p=0.0017). CONCLUSION: Laser denervation and radiofrequency denervation are highly effective methods of minimally invasive treatment of primary trigeminal neuralgia.

[Effectiveness of simultaneous and staged minimally invasive dorsal decompression-stabilization procedures in patients with lumbar spine degenerative diseases]. / Sravnenie effektivnosti ispol'zovaniya simul'tannykh i etapnykh minimal'no-invazivnykh dorsal'nykh dekompressivno-stabiliziruyushchikh vmeshatel'stv u patsientov s degenerativnymi zabolevaniyami poyasnichnogo otdela pozvonochnika.

Minimally invasive procedures reduce the trauma of spine surgery. However, they are associated with high complexity of manipulations, long learning curve, need for expensive equipment for intraoperative navigation and significant irradiation. Various options for surgical approaches are being developed to reduce irradiation of medical staff and patients, surgery time and the number of drugs administered for general anesthesia. Simultaneous surgical interventions (SiSI) is one of these options. OBJECTIVE: To compare the effectiveness of simultaneous and staged minimally invasive dorsal decompression-stabilization procedures in patients with lumbar spine degenerative diseases. MATERIAL AND METHODS: A prospective study included 67 patients (41 men and 26 women) aged 48 (34; 56) years who underwent a single-level minimally invasive spinal root decompression and transforaminal interbody fusion via Wiltse posterior-lateral approach. Two study groups were distinguished: group I (simultaneous surgical interventions, SiSI) (n=29), in which guide spokes and transpedicular screws were installed simultaneously by two surgeons within one x-ray session from two sides; group II (staged surgical interventions, StSI) (n=38), in which staged transpedicular stabilization was performed (decompression side followed by contralateral side). Mean follow-up was 14 months in group I and 20 months in group II. We considered intraoperative fluoroscopy and irradiation dose, duration of surgery and anesthesia with calculation of doses of opioid drugs, blood loss, time of activation, hospital-stay and perioperative morbidity. Clinical outcomes were studied in long-term postoperative period. RESULTS: Simultaneous approach ensured less time of intraoperative fluoroscopy (p=0.029) and irradiation dose (p=0.035), duration of surgery (p=0.01) and anesthesia (p=0.02), amount of opioid drugs during anesthesia (p=0.017). Blood loss, duration of activation and hospitals-stay were similar in both groups (p=0.35, p=0.12 and p=0.57, respectively). There was comparable improvement in VAS score of pain in the lumbar spine and lower extremities in both groups (p=0.63 and p=0.31, respectively). According to SF-36 questionnaire, there was no between-group difference in physical and psychological components (p=0.44 and p=0.72, respectively). There was significantly greater number of adverse effects of anesthesia in the StSI group (26.2% vs. 6.8%, p=0.003). At the same time, the number of surgical postoperative complications was similar in both groups (3.4% vs. 5.3%, p=0.62). CONCLUSION: Simultaneous minimally invasive dorsal decompression-stabilization procedures have some significant advantages over staged approach regarding intraoperative parameters and adverse effects of anesthesia in patients with lumbar spine degenerative diseases. Nevertheless, there were similar clinical data and small incidence of surgical perioperative complications.

[Analysis of the results of surgical treatment of primary trigeminal neuralgia using laser destruction of the sensitive root in elderly and senile patients.]

The aim of the study was to analyze the results of surgical treatment of primary trigeminal neuralgia using laser destruction of the sensitive root in elderly and senile patients. The results of treatment of 25 patients older than 65 years with conservative treatment-resistant trigeminal pain who underwent laser destruction of the sensitive trigeminal root (970 nm, 9 Hz and 3 W power in a total dose of 100 J) in the period from 2018-2019 were prospectively studied. The average follow-up was 12 months. As a result, a significant decrease in the intensity of pain on the scale of facial pain was found from 87 (83,5; 91,5) mm to 15,5 (12,5; 18,5) mm (p=0,002) in the long-term period. On average, 12 months after the operation, a significant improvement in the indicators of the physical and psychological components of health was revealed on the SF-36 questionnaire (p=0,02 and p=0,01, respectively). In the follow-up on the Macnab scale, predominantly excellent (n=23; 92%) and good (n=2; 8%) treatment results were noted. Registered 1 (4%) perioperative complication and 2 (8%) adverse effects of anesthesiology benefits. Thus, the use of laser denervation of the sensitive root in primary trigeminal neuralgia in elderly and senile patients can significantly reduce the level of preoperative pain and improve the quality of life, with low risks of adverse effects.

[Evaluation of the results of using the accelerated recovery program after performing two-level lumbar spinal fusion in patients of an older age group.]

The aim of the study was to evaluate the results of using the accelerated recovery program after performing two-level lumbar spinal fusion in patients of an older age group. The results of surgical treatment of 29 patients older than 65 years with multisegmental degenerative diseases of the lumbar region, who performed minimally invasive two-level rigid stabilization using the concept of «accelerated recovery program¼ (PAR), were retrospectively studied. We studied the technical features of surgical interventions, the specificity of the postoperative period, the number of adverse outcomes of anesthetic benefits and perioperative surgical complications, the frequency of repeated hospitalizations for 90 days. Clinical parameters were used to evaluate the effectiveness of PAR: the level of pain in the area of operation according to the visual analogue scale (VAS) during hospitalization, the quality of life of patients on the SF-36 questionnaire, and patient satisfaction with the result of treatment using the Macnab scale. As a result, it was established that the introduced PAR after performing two-level lumbar spinal fusion in patients of an older age group provides the minimum number of adverse consequences of anesthesiological aid and perioperative surgical complications, a significant restoration of the quality of life and high patient satisfaction with the treatment.