Use Of Xenon Research Articles

Design of ION Thruster

Ion thrusters represent a significant advancement in electric propulsion, enhancing fuel efficiency by accelerating ions for thrust generation. These systems, demonstrated in missions such as Deep Space 1 and Dawn, facilitate substantial velocity changes with minimal propellant, making them suitable for long-duration space missions. This paper outlines the design of an ion thruster aimed at achieving a thrust of 0.2 Newton, focusing on the use of xenon as the propellant and employing highvoltage grids for ion acceleration. Key design aspects include an efficient power supply delivering at least 26 W, effective thermal management, and the integration of control systems. Performance metrics target a specific impulse of 3,000 seconds and a thrust-to-power efficiency ratio greater than 0.5. Through detailed calculations, including arc distance, flow configuration and velocity analyses and testing using different materials, this study identifies optimal configurations for thrust generation. The developed ion thruster is tailored for small satellites (700-800 kg) to enhance trajectory control and station-keeping, underscoring the importance of ion propulsion in modern space exploration

Удосконалення методів нагріву ксенону для запобігання потраплянню рідкої фази робочої речовини до системи подачі

Among the various types of electric propulsion, the Hall thruster type is becoming the most common. This is due to the fact that the use of a Hall thruster makes it possible to obtain high values of the thruster characteristics with a simple design compared to other types of space propulsion systems. For Hall electric propulsion thrusters, the main working substance is xenon because of its fairly high atomic weight, low ionization energy, and unreactiveness, which makes it possible to obtain high thruster characteristics with ease of operation. The use of xenon as a working substance features a peculiarity involving its critical temperature (289.74 K), which gives rise to the liquid phase in the tank and, accordingly, pressure jumps, thus making it impossible to use the xenon feed system. To exclude the ingress of the liquid phase of xenon into the accumulator tank in electric propulsion systems, heaters are placed on the xenon tank to maintain its temperature within a given range. However, this approach has the following disadvantages: the low thermal conductivity of composite tanks impairs heater-to-xenon heat transfer; warming up the whole of the tank before starting the thruster increases the thruster start-up preparation time; the continuous maintenance of the tank temperature increases energy consumption by the propulsion system; and it is impractical to maintain the temperature of the whole of the xenon, while only a few grams of it are consumed for one thruster start-up. The problem that was solved in this work consists in changing the approach to heating the working substance that enters the feed system. The analysis of literary sources showed that this problem is relevant and offers ways to improve existing methods. To solve this problem, theoretical calculations were carried out and verified by experiment. As a result, a method was proposed to calculate the gasifier so that it may maintain the temperature of the working substance entering the accumulator tank within the range from 293 K to 298 K, thus eliminating the possible ingress of the liquid phase of xenon into the accumulator tank of the feed system. This study allows one to use the proposed structural element (gasifier) instead of tank heaters, which significantly reduces power consumption and maintains the stable operation of the working substance feed system. The conclusions drawn from the study may be useful to most developers of storage and feed systems for electric propulsion systems.

Neuroprotective properties of xenon. Literature review

A systematic analysis of scientific research devoted to the study of neuroprotective properties of xenon was carried out to determine the possibility of its use for the protection of neuronal tissues in various pathological conditions and neurodegenerative disorders. The search was carried out in freely available scientometric databases, such as PubMed, Google Scholar, Web of Science, Scopus, etc. The criteria for inclusion in the analysis were publications that discussed the role of xenon in the protection of neuronal tissues, studies of the neuroprotective properties of xenon in animal and cellular models, clinical studies demonstrating the neuroprotective potential of xenon in available English-language sources. The literature was analyzed to identify key findings, research methodology, and outcomes related to the neuroprotective properties of xenon. This included an analysis of research methods, models used to assess the impact of xenon on neuronal structures, and the volume and quality of the data obtained. In addition, the pharmacological properties of xenon are considered, in particular, its physicochemical characteristics, mechanisms of action at the molecular level, and pharmacokinetics. The results of studies of the influence of xenon on the state of vascularization of the brain after after traumatic brain injury and the potential of xenon to prevent further injuries are presented. Studies evaluating the effects of xenon on neurological deficits after ischemic stroke and its potential efficacy as an anti-inflammatory and neuroprotective agent are discussed. The effect of xenon on the white matter of the brain in patients with aneurysmal subarachnoid hemorrhage and its potential to reduce damage are highlighted. Research data on the use of the liposomal form of xenon to improve the condition after a stroke, mental health, and the effect of xenon on the intestinal microbiota were analyzed. The results of studies on the effectiveness of repeated injections of xenon to improve sensorimotor and neuropsychic functions in patients after a stroke, as well as the use of xenon as one of the components of intensive therapy for alcohol poisoning and the potential advantages of such an approach are presented. Based on the analysis of literary sources, it was concluded that xenon is a promising tool for protecting brain structures in traumatic injuries and ischemic lesions, which improves rehabilitation. It reduces inflammation and increases the integrity of the blood-brain barrier, which helps restore brain function.

Possible Approaches for Combined Use of Xenon and Gallium Ion Sources for Task Specific Focused Ion Beam Sample Preparation

Possible Approaches for Combined Use of Xenon and Gallium Ion Sources for Task Specific Focused Ion Beam Sample Preparation

Choice of Anesthesia for Orthopedic Surgery in Elderly and Senile Patients (Review)

Management of elderly and senile patients is a major challenge due to significant comorbidity, especially in surgery under general anesthesia.The aim of the review was to identify the optimal method of anesthesia for knee arthroplasty in elderly patients based on the available clinical and experimental studies.We searched PubMed, Medline, and Elibrary.ru databases for relevant sources. Out of more than 300 publications initially analyzed, 113 literature sources (dating from 1951 to 2021) were included in the review, of which 80 were published within the last five years (2016–2021). The inclusion criteria were high informative value and relevance, except for sources cited as historical references. Both randomized multicenter studies and individual case reports were included in the review. Exclusion criteria were low informative value, outdated and repetitive data.We reviewed the physiology of elderly and senile patients, various variants of anesthesia, the use of neuroaxial anesthesia and peripheral regional blocks, xenon-based general anesthesia, assessed the advantages and drawbacks of each method, and discussed the monitoring of the depth of anesthesia and the issues of inraoperative awareness during knee arthroplasty in elderly and senile patients.Conclusion. The choice of anesthesia for knee arthroplasty in elderly and senile patients should be based on the risks of decompensation of cardiovascular comorbidities and cognitive impairment. No known anesthetic method is ideal in terms of safety. The use of xenon as the main anesthetic seems promising due to its cardio- and neuroprotective properties. However, its use is limited due to relatively high cost. Therefore, the search for optimal (lower than recommended) inhalation concentrations may lead to expanding use of xenon in elderly and senile patients. At the same time, the use of lower concentrations of the drug is associated with the intraoperative awakening and the need for its combination with narcotic analgesics or amnestic agents, which may not be optimal. In addition, the protective effect of xenon retrograde amnesia against the stress of unintended intraoperative awakening has not been studied, and routine methods of monitoring the depth of hypnosis when using xenon often yield skewed measurement results inconsistent with the clinical manifestations of anesthesia.Therefore, there is a need for further studies concerning the retrograde amnesic effect of xenon and search for optimal methods of assessing the depth of hypnosis when using this gas to safely reduce its inhalation concentration.

Effect of Xenon on Proinflammatory Activation and Apoptosis of Human Neutrophils Under Ex Vivo Conditions

Background. The syndrome of systemic inflammatory response, which underlies the damaging effect of factors of infectious and non-infectious genesis, may cause multiple organ failure. The degree of its severity is determined, among other things, by the activation of neutrophils. The paper highlights new mechanisms of the anti-inflammatory action of the inhalation anesthetic xenon, mediated by a decrease in the ability of neutrophils to pro-inflammatory response.Aim of study. To evaluate the effect of xenon on the activation of human neutrophils under ex vivo conditions.Material AND methods. We studied the effect of xenon inhalation on reduction of the ability of neutrophils to be activated proinflammatory by reduced expression of adhesion molecules CD11b and CD66b on the surface of neutrophils and on the phosphorylation of proinflammatory kinases: ERK 1/2 and kinase — p38 in neutrophils of healthy volunteers.Results. The use of xenon at a dose of 30 vol. % within 60 minutes in healthy volunteers statistically significantly reduces the ability of neutrophils to proinflammatory activation. The addition of lipopolysaccharide (LPS) to the incubation medium of neutrophils causes their pronounced activation, statistically significantly increasing the phosphorylation of key proinflammatory neutrophil kinases ERK1/2 and kinase p38. Inhalation of xenon in volunteers (30% within 60 minutes) has a pronounced anti-inflammatory effect on LPS-stimulated neutrophils, decreasing their activation by inhibiting pro-inflammatory kinase ERK1/2 and pro-inflammatory MAP kinase p38.Conclusion. The actual study, performed on isolated neutrophils from volunteers who underwent xenon inhalation, revealed the anti-inflammatory properties of the inert gas xenon, which, in our opinion, may have a direct relationship to the identification of the mechanism of its neuroprotective properties. Thus, the research results available today suggest that xenon has a pronounced pleiotropic mechanism of brain protection. This is a partial blockade of NMDA receptors, and phosphorylation of the enzyme glycogen synthase-3β, and limitation of the inflammatory activation of neutrophils.Findings. Inhalation of xenon in volunteers (30% within 60 minutes) has a pronounced anti-inflammatory effect on neutrophils stimulated by lipopolysaccharides, decreasing their activation by inhibiting proinflammatory ERK 1/2 kinase and proinflammatory MAP kinase p38, as well as reducing the expression of markers of activation and degranulation CD11b and CD66b on the surface of neutrophils. Stimulation by lipopolysaccharides statistically significantly reduces spontaneous apoptosis of neutrophils, while xenon increases the ability of neutrophils to apoptosis, which is likely to contribute to the resolution of inflammation.

Removing CO2 from Xenon anaesthesia circuits using an amino-acid ionic liquid solution in a membrane contactor

• System capacity increased from 3.50 to 4.97 mol CO 2 /kg IL when breathing cycles were simulated. • Higher amount of anaesthetic gas can be recycled when Xe is used. • Ion-exchange allows for releasing CO 2 enabling the reuse of the IL solution. The noble gas xenon possesses many characteristics of an ideal anaesthetic agent. However, its application is limited in daily clinical routine due to its elevated price. The present work proposes the use of a gas-ionic liquid membrane contactor system in anaesthesia closed-circuits, for the removal of carbon dioxide, to allow the recycling of the anaesthetic agents, as a route to enable the widespread use of xenon. In this work, different anaesthetic gas delivery conditions were simulated and explored, considering the use of different anaesthetic gas mixtures. The results obtained, using a cholinium lysinate ionic liquid solution as CO 2 absorbent, expressed high efficiency, especially when xenon was used as the inhalational anaesthetic, leading to an overall CO 2 mass transfer of 1.26 × 10 −5 m.s −1 . The ability of the proposed system to recover xenon allows to reduce drastically the cost per operation, which can be a step forward for the routine use of this gas on surgeries. Additionally, this work evaluates the use of thermal and chemical regeneration of the ionic liquid solution. It was found that the thermal regeneration approach was not adequate for the regeneration of the IL. On the other hand, the use of ion-exchange resins proved to be an efficient and simple strategy for IL regeneration, allowing for an easy integration in the proposed system. This study opens a new direction not yet explored that may lead to more efficient IL regeneration processes.

Effect of Xenon on the Phosphorylation of Glycogen Synthase Kinase 3β and Antioxidant Enzymes in Rat Brain

Relevance. The increase in the number of severe brain injuries due to stroke and traumatic brain injury determines the need to study and develop effective strategies for neuroprotection. The article highlights new mechanisms of the neuroprotective action of the inhalation anesthetic xenon based on the data of our own experimental studies.Aim of study. To assess the effect of anesthesia with xenon at a concentration of 0.5 MAC (minimum alveolar concentration) on the phosphorylation of glycogen synthase kinase 3β (GSK-3β) and the content of antioxidant defense enzymes in the rat brain.Material and methods. The effect of inhalation anesthesia with xenon on the phosphorylation of the GSK-3β enzyme in comparison with lithium chloride, as well as on the content of heme oxygenase, catalase, and Mn-superoxide dismutase in rat brain homogenates was studied by immunoblotting.Results. The use of xenon at a concentration of 0.5 MAA causes an almost twofold increase in the content of the phosphorylated form of the GSK-3β enzyme in comparison with the control (p<0.05) and significantly increases the pool of antioxidant defense enzymes: heme oxygenase by 50% (p <0.05) and Mn-superoxide dismutase by 60% (p<0.05).Conclusion. The conducted experimental study revealed new molecular mechanisms of action of the inhalation anesthetic xenon. The effect of xenon on the pool of enzymes involved in the protection of the brain from oxidative distress was found. The data obtained indicate the prospects for using xenon and require further research in this direction. The use of xenon at a concentration of 50 vol.% (0.5 MAA) for 30 minutes does not affect the content of the glycogen synthase-3β enzyme, at the same time causing an almost twofold increase in its phosphorylated form, the glycogen synthase-3β enzyme, and is accompanied by a significant increase the content of heme oxygenase, Mn-superoxide dismutase and a slight increase in the content of catalase in rat brain homogenates. Thus, the results of the study suggest that one of the possible mechanisms of the neuroprotective effect of xenon is the phosphorylation of glycogen synthase-3β, which prevents the opening of the mitochondrial pore, inhibiting the death of mitochondria-mediated apoptosis of neurons and increasing the level of antioxidant protection in them.

Combined Xenon and Epidural Anesthesia During Surgical Correction of Joint Deformities in the Lower Extremities of Children with Cerebral Palsy

Objectives. The objective of this study is to compare different methods of combination general and regional anesthesia based on xenon.Materials and methods. Xenon anesthesia combined with epidural block was performed in 50 children with cerebral palsy aged 3–17 years. In 30 patients xenon was used to maintain anesthesia, in 20 children xenon was combined with sevoflurane. We compared the process of anesthesia, the intraoperative hemodynamic parameters and cognitive status before surgery and after it.Results. The use of xenon in all studied anesthesia methods increased the cardiac performance and was associated with a stable hemodynamic profile at all stages of anesthesia despite the depressive effect of epidural blockade on hemodynamics. Psychological testing revealed that xenon anesthesia has no negative effect on cognitive functions in children with cerebral palsy.Conclusion. Xenon anesthesia is a promising trend in anesthesia care for children with cerebral palsy. Xenon can compensate the hemodynamic depression caused by epidural anesthesia due to its cardiac stimulant property, with no neurotoxicity being a significant benefit for children with initial damage of CNS. However, anesthesia with xenon turned out to have some disadvantages. In our study, xenon showed insufficient analgesic properties, had emetic properties and was associated with spirometric abnormalities. It was more difficult to maintain normal ventilation parameters in young children when using xenon. Several adverse events were noted in the recovery period. These disadvantages can be partially reduced by using a combination of xenon and sevoflurane.

Intraoperative xenon for prevention of delirium after on-pump cardiac surgery: a randomised, observer-blind, controlled clinical trial

BackgroundOlder patients undergoing cardiac surgery have a 40–60% risk of developing postoperative delirium (POD), which is associated with increased morbidity and mortality. In animals, xenon has been found to be neuroprotective. Little is known about its neuroprotective effects in humans. We evaluated whether xenon anaesthesia prevents POD in patients undergoing cardiac surgery. MethodsWe conducted a randomised, observer-blind, controlled trial in which 190 patients 65 yr or older undergoing on-pump cardiac surgery were randomly allocated to xenon or sevoflurane anaesthesia. During cardiopulmonary bypass, propofol infusion was used for anaesthetic maintenance. Subjects were screened for POD daily during the first 5 postoperative days using the 3-Minute Diagnostic Interview for Confusion Assessment Method (CAM) or with a CAM version for patients in ICU (CAM-ICU). Other methods to detect delirium, such as chart review, were also used. Secondary outcomes included the duration and severity of POD, and postoperative cognitive function. ResultsThe overall incidence of POD was 41% (78/190). There was no statistically significant difference in the POD incidence between the xenon and sevoflurane groups (42.7% [41/96] vs 39.4% [37/94], P=0.583). The odds ratio for POD when comparing xenon with sevoflurane was 1.18 (95% confidence interval, 0.65–2.16). ConclusionsIn older patients undergoing cardiac surgery, xenon anaesthesia did not result in a significant reduction in POD. Based on these results alone, use of xenon cannot be recommended for this purpose. Clinical trial registrationEudraCT: 2014-005370-11 (May 13, 2015; https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-005370-11).

Xenon anesthesia during the oral cavity sanitation in child with consequences of perinatal brain damage

Halogenated inhalation anesthetics have some adverse effects, including the ability to have a negative effect on the developing brain in children, one of the manifestations of which are cognitive dysfunctions, especially in the younger age group. The article presents a clinical case of xenon in combined inhalation anesthesia in a child with the consequences of perinatal brain damage. During anesthesia, a spontaneous ventilation mode was applied with pressure support ventilation (PSV). There was noted high efficacy and safety xenon anesthesia in a dental treatment, the absence of the effect of anesthesia on cognitive function in a child with a compromised nervous system. It is advisable to further study the use of xenon in the pediatric dentistry anesthesia.

Xenon anesthesia for awake craniotomy: safety and efficacy.

The asleep-awake-asleep (AAA) craniotomy is a technique that offers the opportunity of having a patient fully cooperative during the awake phase, and minimizes the possible discomfort, due to the asleep phase. The aim of this prospective observational study was to test the use of xenon in the first asleep phase of an AAA craniotomy, in patients undergoing craniotomy for brain tumor resection. The data have been collected from 40 awake craniotomy procedures, performed in patients with cerebral tumor, treated with the AAA technique. Patients were treated with xenon during the asleep phase, and quality of mapping, complications and qualitative judgment of the experience given by the patients were recorded. The mapping was carried out as planned in 37 out of 40 cases. The doses of xenon administered during the first asleep phase of the anesthesia was 13±2 L. Time for awakening after xenon was switched off was 5±1 minute. A combination of xenon and regional anesthesia (with no need for additional systemic anesthetics) was adequate to accomplish craniotomy in 27/40 patients (67.5%). On the day after the operation, 37 patients recalled the testing procedure for mapping during the awake period, none had recollection of local anesthetic injections for regional anesthesia or sound associated with the neurosurgical drill. Five patients (12.5%) reported mild pain during tumor removal (VAS Score less than three). In this case series, xenon anesthesia was successfully used for the sedative phase of an awake craniotomy accomplished with an AAA approach.

Neurologic and cognitive outcomes associated with the clinical use of xenon: a systematic review and meta-analysis of randomized-controlled trials.

Xenon has been shown to have positive neurologic effects in various pre-clinical models. This study systematically reviewed the randomized-controlled trials (RCTs) investigating neurologic and cognitive outcomes associated with the clinical use of xenon. We searched PubMed, CENTRAL, EMBASE, CINAHL, elibrary.ru (for Russian studies), Google Scholar (for Russian studies), and Wanfang (for Chinese studies) for appropriate RCTs comparing neurologic or cognitive outcomes after clinical use of xenon with control treatment or with other anesthetic agents. Seventeen RCTs met the inclusion criteria. Two studies investigated the effects of xenon plus therapeutic hypothermia to treat neonatal asphyxia or out-of-hospital cardiac arrest. Compared with therapeutic hypothermia alone, xenon and therapeutic hypothermia reduced cerebral white matter abnormalities after cardiac arrest but had no effect on neurocognitive outcome and mortality. Xenon had no added value when used to treat neonatal asphyxia. Thirteen RCTs compared neurocognitive effects of xenon with other anesthetic agents in surgical patients. While xenon may be associated with improved short-term (< three hours) cognitive outcome, no medium-term (six hours to three months) advantage was observed, and longer-term data are lacking. No differences in biochemical (S-100β, neuron-specific enolase) and neuropsychologic (attentional performance) outcomes were found with xenon compared with other anesthetic drugs. Finally, two studies suggest that brief, intermittent administration of sub-anesthetic doses of xenon to patients during the acute phase of substance withdrawal may improve neurocognitive outcomes. Despite promising pre-clinical results, the evidence for positive clinical neurologic and cognitive outcomes associated with xenon administration is modest. Nevertheless, there is some evidence to suggest that xenon may be associated with better neurologic outcomes compared with the standard of care therapy in certain specific clinical situations. More clinical trials are needed to determine any potential benefit linked to xenon administration.

Clinical efficacy of xenon versus propofol: A systematic review and meta-analysis.

Background:Interest in the anesthetic use of xenon, a noble gas, has waxed and waned for decades, and the clinical effects of xenon are still debated. We performed a meta-analysis to compare the clinical efficacy of xenon with that of propofol.Methods:Electronic searches were performed through December 2017 using various databases, including PubMed, Embase, and the Cochrane Library. We identified thirteen trials that included a total of 817 patients.Results:Patients treated with xenon had a lower bispectral index (BIS) (weighted mean difference (WMD): −6.26, 95% confidence interval (CI): −11.33 to −1.18, P = .02), a higher mean arterial blood pressure (MAP) (WMD: 7.00, 95% CI: 2.32–11.68, P = .003) and a lower heart rate (HR) (WMD: −9.45, 95% CI: −12.28 to −6.63, P < 0.00001) than propofol-treated patients. However, there were no significant differences between the 2 treatment groups in the effects of nondepolarizing muscular relaxants, the duration spent in the postanesthesia care unit (PACU) (WMD: −0.94, 95% CI: −8.79–6.91, P = .81), or the incidence of perioperative complications [assessed using the outcomes of postoperative nausea and vomiting (PONV) (relative risk (RR): 2.01, 95% CI: 0.79–5.11, P = .14), hypotension (RR: 0.62, 95% CI: 0.27 to 1.40, P = .25), hypertension (RR: 1.27, 95% CI: 0.73–2.21, P = .39) and bradycardia (RR: 1.00, 95% CI: 0.36–2.74, P = 1.00)].Conclusion:In this meta-analysis of randomized controlled trials, we found that xenon treatment resulted in a higher MAP, a lower HR, and a smaller BIS index than treatment with propofol.

Effect Of Chronic Xenon Supplementation On Hematological Parameters, Cardiorespiratory Fitness, and Athletic Performance

ObjectiveXenon is an inhalational anesthetic with the potential to improve athletic performance and cardiorespiratory fitness via proposed increases in total blood volume. This study aimed to determine the effect of a four‐week xenon supplementation protocol on total blood volume, maximal oxygen uptake (V̇2max) and 3‐kilometre time trial performance in trained individuals.MethodsFourteen subjects (32 ± 12 years; 71% male) were assessed for total blood volume through the carbon monoxide rebreathing method, cardiorespiratory fitness via V̇O2max on a treadmill test, and athletic performance using a 3 km time trial. Following baseline assessments, subjects were matched for sex, age and V̇O2max, and were randomised to 12 sessions of gas inhalation over four weeks (2 minutes of inhalation on 3 days per week); 1) xenon, n = 7 (70% xenon, 21% oxygen, 9% nitrogen) or 2) sham gas, n=7 (7% carbon dioxide, 21% oxygen, 62% nitrogen) dosing. Subjects were blinded to group allocation and all outcomes were re‐assessed following the four‐week dosing period. Within‐group mean differences and 95% confidence intervals for outcomes of interest are presented in Table 1. Differences between the xenon and sham gas group over time were tested using two‐way repeated measures ANOVA and are represented by P values.ResultsXenon and sham groups were equal at baseline for all outcomes of interest (Table 1). Twelve subjects completed the four‐week dosing intervention and are included in the analyses; one subject withdrew after a single xenon dose due to nausea and one subject was withdrawn after one week of xenon inhalation due to adverse symptoms during and after dosing which resembled sleep paralysis. Blinding was equally effective between groups; subjects in the xenon group were 65% certain of group allocation, while subjects in the sham group were 63% certain of group allocation. There were no significant differences between xenon or sham gas groups for changes in total blood volume, V̇O2max, or 3 km time trial performance (Table 1).ConclusionsFour weeks of xenon inhalation did not result in significant changes in total blood volume, cardiorespiratory fitness or athletic performance in comparison to a sham gas. Given the presence of adverse symptoms in approximately 30% (2 out of 7) subjects and a clear absence of physiological and performance benefits, our findings do not support the use of xenon as a performance enhancing substance.Support or Funding InformationThis study was supported in part by funding from the Partnership for Clean Competition Research Collaborative.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The influence of xenon-therapy on tolerance of adjuvant radiotherapy in patients with single brain metastasis

Objective: to study the tolerance of radiotherapy by adding the boost and the xenon-therapy during the whole brain radiotherapy (WBRT) in patients with single brain metastasis. Materials and methods: the study involved 60 patients divided in the 3 equal groups (20 people in each group) where the treatment varied according the methods of the adjuvant radiotherapy. The patients in the first group were assigned to receive WBRT alone, in the second group — WBRT and the boost to tumor bed, in the third group — WBRT and the boost in combination with the xenon-oxygen inhalations. The quality of life, the toxic and adaptation reaction, the psychological status and the electrical activity of the brain during the treatment were also included in the research. Results: the increase of side-effects of the treatment and the quantity of stress-reactions occurred during WBRT in combination with the boost. But the use of xenon allowed to level all the negative reactions and even to improve some of physiological and psychological parameters. The xenon-oxygen inhalations led to the decrease of intensity of situational anxiety and depression. There was also a reduction in delta-activity level according to EEG and a return of the other rhythms to baseline levels which was lacking in the other groups. Conclusions: the use of the xenon-therapy in combination with WBRT by the developed methods allows to improve the quality of life in patients with radiation treatment, as well as to reduce the degree of the intensity of side and toxic reactions. The results of objective methods at the trial demonstrate the stresseless and radioprotective effects of xenon.

Performance tests of IPPLM's krypton Hall thruster

AbstractThe Institute of Plasma Physics and Laser Microfusion's (IPPLM) Hall effect thruster (Krypton Large IMpulse Thruster, KLIMT) is a 500 W class plasma engine with a mean diameter of discharge channel of 42 mm. KLIMT was developed within ESA/PECS project aiming to provide relatively small thruster for satellites that would be able to effectively operate with krypton propellant. Being several times less expensive than xenon, which is regarded as a propellant of choice for electric propulsion of electrostatic type, krypton since years has been suggested as an attractive alternative. In this paper, a design as well as performance tests of the laboratory model of KLIMT are discussed. It is shown that precise adjustment of magnetic field topography results in the stable operation of the thruster in wide range of operating conditions providing similar thrust and specific impulse production for both propellants. Maximum thrust produced with the use of xenon and krypton reached about 16–17 mN for mass flow rate of 1.15–1.2 mg/s resulting in specific impulse in the range of 1300–1500 s (13–15 km/s). However, for krypton the anode efficiency drops by ~10% in comparison with xenon. For krypton plasma beam divergence as measured by an average half-angle with respect to the beam axis was found to remain within the range of 19–23° for the whole set of the examined operating conditions. The reported characteristics are reasonable for Hall thruster of the discussed size and power.

Neuroprotection in newborns. Review of current evidence

Neonatal hypoxia / ischemia increases morbidity and mortality, influences the further development of the child. This review presents current evidence of the effect of some substances with supposedly neuroprotective properties on the outcomes of newborn with perinatal encephalopathy. The results of the different temperature regimes after intranatal asphyxia are discussed. In previous trials, the efficacy and safety of therapeutic hypothermi a has been proven. Its use is enshrined in international recommendations on cardiop ulmonary resuscitation. However, in recent studies, no difference in outcomes is observed with the use of therapeutic hypothermia in comparison with normothermia. Evidence of the effect on the further neurological development the use in the early neonatal period of recombinant human erythropoietin in neonates with perinatal asphyxia is presented. Based on the results of the first randomized controlled trial, the use of xenon in combination with hypothermia did not lead to better outcomes than hypothermia alone. Data are given on the effect of caffeine citrate on the further neurological devel opment of children who received a drug for the treatment of apnea of prematurity in the neonatal period.

The Modification and Performance of a Large Animal Anesthesia Machine (Tafonius®) in Order to Deliver Xenon to a Horse.

Xenon, due to its interesting anesthetic properties, could improve the quality of anesthesia protocols in horses despite its high price. This study aimed to modify and test an anesthesia machine capable of delivering xenon to a horse. An equine anesthesia machine (Tafonius, Vetronic Services Ltd., UK) was modified by including a T-connector in the valve block to introduce xenon, so that the xenon was pushed into the machine cylinder by the expired gases. A xenon analyzer was connected to the expiratory limb of the patient circuit. The operation of the machine was modeled and experimentally tested for denitrogenation, wash-in, and maintenance phases. The system was considered to consist of two compartments, one being the horse's lungs, the other being the machine cylinder and circuit. A 15-year-old, 514-kg, healthy gelding horse was anesthetized for 70 min using acepromazine, romifidine, morphine, diazepam, and ketamine. Anesthesia was maintained with xenon and oxygen, co-administered with lidocaine. Ventilation was controlled. Cardiorespiratory variables, expired fraction of xenon (FeXe), blood gases were measured and xenon was detected in plasma. Recovery was unassisted and recorded. FeXe remained around 65%, using a xenon total volume of 250 L. Five additional boli of ketamine were required to maintain anesthesia. PaO2 was 45 ± 1 mmHg. The recovery was calm. Xenon was detected in blood during the entire administration time. This pilot study describes how to deliver xenon to a horse. Although many technical problems were encountered, their correction could guide future endeavors to study the use of xenon in horses.

An installation for studying luminescence excited by high-energy charged particles in dense xenon-containing gas mixtures with the possibility of regeneration and repeated use of xenon

An installation for studying the spectral, temporal, and generation characteristics of xenon-containing high-pressure excimer mixtures is described. The mixtures are excited by a pulsed beam of fast electrons with energy Е e = 220 keV, pulse duration Т p = 5 ns, and maximum beam current density I max = 20 A/cm2. Spectral and temporal measurements are taken in the wavelength range of 200–1200 nm with a wavelength resolution of 1 nm (the Maya-2000Pro spectrometer) and a temporal resolution of 2 ns/cm (a Tektronics TDS1024 oscilloscope and a FEU-106 photomultiplier tube). To reduce the xenon consumption when carrying out experimental investigations, the installation is equipped with a system of xenon peeling and regeneration, which allows the xenon loss to be reduced by factors of 50–100. The use of one additional external mirror for determining the gain characteristics of high-pressure excimer mixtures upon pumping with fast charged particles is considered.