Air Medical Transport of a 12-Year-Old Girl With Cerebral Gas Embolism Due to Helium Inhalation.

This case report describes the initial care and transport considerations of a pediatric patient who suffered from cerebral gas embolism sustained after inhalation of helium from a pressurized tank. The patient demonstrated neurologic symptoms necessitating hyperbaric oxygen therapy and required fixed wing air transport across a mountain range from a rural community hospital to a tertiary center for the treatment. We review the pathophysiology of cerebral gas embolism and strategies for transporting patients with cerebral gas embolism and other trapped gas.

What about nitrogen? Using nitrogen as a carrier gas during the analysis of petroleum biomarkers by gas chromatography mass spectrometry.

Gas chromatography mass spectrometry (GC-MS) is a commonly used method for organic geochemistry for both academic research and applications such as petroleum analysis. Gas chromatography requires a carrier gas, which needs to be both volatile and stable and in most organic geochemical applications helium or hydrogen have been used, with helium predominating for gas chromatography mass spectrometry. Helium, however, is becoming an increasingly scarce resource and is not sustainable. Hydrogen is the most commonly considered alternative carrier gas to helium but has characteristics that in certain respects make its use less practical, foremost is that hydrogen is flammable and explosive. But as hydrogen is increasingly used as a fuel, higher demand may also make its use less desirable. Here we show that nitrogen can be used for the GC-MS analysis of fossil lipid biomarkers. Using nitrogen, chromatographic separation of isomers and homologues can be achieved, but sensitivity is orders of magnitude less than for helium. It is reasonable to use nitrogen as a carrier gas in applications where low levels of detection are not needed, such as the characterization of samples of crude oil or foodstuffs, or potentially as part of a gas-mixture seeking to reduce helium-demand but maintain a level of chromatographic separation sufficient to support proxy-based characterizations of petroleum.

Comparison of treatment recompression tables for neurologic decompression illness in swine model.

BACKGROUND: Significant reductions in ambient pressure subject an individual to risk of decompression illness (DCI); with incidence up to 35 per 10,000 dives. In severe cases, the central nervous system is often compromised (>80%), making DCI among the most morbid of diving related injuries. While hyperbaric specialists suggest initiating recompression therapy with either a Treatment Table 6 (TT6) or 6A (TT6A), the optimal initial recompression treatment for severe DCI is unknown. METHODS: Swine were exposed to an insult dive breathing air at 7.06 ATA (715.35 kPa) for 24 min followed by rapid decompression at a rate of 1.82 ATA/min (184.41 kPa/min). Swine that developed neurologic DCI within 1 hour of surfacing were block randomized to one of four United States Navy Treatment Tables (USN TT): TT6, TT6A-air (21% oxygen, 79% nitrogen), TT6A-nitrox (50% oxygen, 50% nitrogen), and TT6A-heliox (50% oxygen, 50% helium). The primary outcome was the mean number of spinal cord lesions, which was analyzed following cord harvest 24 hours after successful recompression treatment. Secondary outcomes included spinal cord lesion incidence and gross neurologic outcomes based on a pre- and post- modified Tarlov assessment. We compared outcomes among these four groups and between the two treatment profiles (i.e. TT6 and TT6A). RESULTS: One-hundred and forty-one swine underwent the insult dive, with 61 swine meeting inclusion criteria (43%). We found no differences in baseline characteristics among the groups. We found no significant differences in functional neurologic outcomes (p = 0.77 and 0.33), spinal cord lesion incidence (p = 0.09 and 0.07), or spinal cord lesion area (p = 0.51 and 0.17) among the four treatment groups or between the two treatment profiles, respectively. While the trends were not statistically significant, animals treated with TT6 had the lowest rates of functional deficits and the fewest spinal cord lesions. Moreover, across all animals, functional neurologic deficit had strong correlation with lesion area pathology (Logistic Regression, p < 0.01, Somers' D = 0.74). CONCLUSIONS: TT6 performed as well as the other treatment tables and is the least resource intensive. TT6 is the most appropriate initial treatment for neurologic DCI in swine, among the tables that we compared.

Hyperbaric oxygen for the treatment of severe subcutaneous and mediastinal emphysema after Renuvion/J-Plasma therapy®.

Subcutaneous and mediastinal emphysema are known complications of liposuction and body sculpting procedures. Treatment options are limited, and recovery is often prolonged. We discuss a case of severe subcutaneous and mediastinal emphysema after a skin-tightening procedure involving helium gas. The patient received one treatment of hyperbaric oxygen and was followed until symptom resolution. We review the known literature on hyperbaric oxygen therapy as a treatment for subcutaneous emphysema.

Cold atmospheric pressure He-plasma jet and plasma ball interactions with the Venus flytrap: Electrophysiology and side effects.

Cold atmospheric pressure radio frequency plasma (CAPP) can play an important role in agriculture, medicine, biophysical and bioelectrochemical applications, disinfection and sterilization, synthesis of different compounds, nitrogen fixation, and treatment of surfaces. Here we found that reactive oxygen and nitrogen species, UV-Vis photons, and high-frequency strong electromagnetic fields with an amplitude of a few kV produced by a cold plasma jet can interact with bio-tissue and damage it if the plasma treatment is long enough. The electrophysiological effects of CAPP treatment of bio-tissue and electrical signals transmission were measured in the Venus flytrap. The plasma ball does not produce any visible side effects on the Venus flytrap, but induces electrical signals in bio-tissue with very high amplitude. Plasma (Kirlian) photography shows the existence of a blue aura around the plasma ball due to a corona discharge. Understanding the mechanisms of interactions between CAPP and bio-tissue and preventing side effects can contribute to the application of plasma technology in medicine and agriculture. The use of cold plasma in medicine and agriculture should be monitored for side effects from strong high-frequency electro-magnetic fields, UV photons, and reactive oxygen and nitrogen species to protect against undesirable consequences.

Thermovaccination - thermoheliox as a stimulator of the immune response. Kinetics of the synthesis of antibodies and C-reactive protein in coronavirus infection.

Clinical trials of thermoheliox application (inhalation with a high-temperature mixture of oxygen and helium, 90 °C) in the treatment of the acute phase of coronavirus infection were conducted. Dynamics of disease development in infected patients (PCR test for the virus) and, dynamics of changes in blood concentration of C-reactive protein, immunoglobulin M, specific immunoglobulin G were studied. High efficiency of thermoheliox in releasing the organism from the virus and stimulating the immune response (thermovaccination effect) was shown. The kinetic model of the process is proposed and analyzed.

Laparoscopic surgery for endometriosis.

BACKGROUND: Endometriosis is associated with pain and infertility. Surgical interventions aim to remove visible areas of endometriosis and restore the anatomy. OBJECTIVES: To assess the effectiveness and safety of laparoscopic surgery in the treatment of pain and infertility associated with endometriosis. SEARCH METHODS: This review has drawn on the search strategy developed by the Cochrane Gynaecology and Fertility Group including searching the Cochrane Gynaecology and Fertility Group's specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, reference lists for relevant trials, and trial registries from inception to April 2020. SELECTION CRITERIA: We selected randomised controlled trials (RCTs) that compared the effectiveness and safety of laparoscopic surgery with any other laparoscopic or robotic intervention, holistic or medical treatment, or diagnostic laparoscopy only. DATA COLLECTION AND ANALYSIS: Two review authors independently performed selection of studies, assessment of trial quality and extraction of relevant data with disagreements resolved by a third review author. We collected data for the core outcome set for endometriosis. Primary outcomes included overall pain and live birth. We evaluated the quality of evidence using GRADE methods. MAIN RESULTS: We included 14 RCTs. The studies randomised 1563 women with endometriosis. Four RCTs compared laparoscopic ablation or excision with diagnostic laparoscopy only. Two RCTs compared laparoscopic excision with diagnostic laparoscopy only. One RCT compared laparoscopic ablation or excision with laparoscopic ablation or excision and uterine suspension. Two RCTs compared laparoscopic ablation and uterine nerve transection with diagnostic laparoscopy only. One RCT compared laparoscopic ablation with diagnostic laparoscopy and gonadotropin-releasing hormone (GnRH) analogues. Two RCTs compared laparoscopic ablation with laparoscopic excision. One RCT compared laparoscopic ablation or excision with helium thermal coagulator with laparoscopic ablation or excision with electrodiathermy. One RCT compared conservative laparoscopic surgery with laparoscopic colorectal resection of deep endometriosis infiltrating the rectum. Common limitations in the primary studies included lack of clearly described blinding, failure to fully describe methods of randomisation and allocation concealment, and poor reporting of outcome data. Laparoscopic treatment versus diagnostic laparoscopy We are uncertain of the effect of laparoscopic treatment on overall pain scores compared to diagnostic laparoscopy only at six months (mean difference (MD) 0.90, 95% confidence interval (CI) 0.31 to 1.49; 1 RCT, 16 participants; very low quality evidence) and at 12 months (MD 1.65, 95% CI 1.11 to 2.19; 1 RCT, 16 participants; very low quality evidence), where a positive value means pain relief (the higher the score, the more pain relief) and a negative value reflects pain increase (the lower the score, the worse the increase in pain). No studies looked at live birth. We are uncertain of the effect of laparoscopic treatment on quality of life compared to diagnostic laparoscopy only: EuroQol-5D index summary at six months (MD 0.03, 95% CI -0.12 to 0.18; 1 RCT, 39 participants; low quality evidence), 12-item Short Form (SF-12) mental health component (MD 2.30, 95% CI -4.50 to 9.10; 1 RCT, 39 participants; low quality evidence) and SF-12 physical health component (MD 2.70, 95% CI -2.90 to 8.30; 1 RCT, 39 participants; low quality evidence). Laparoscopic treatment probably improves viable intrauterine pregnancy rate compared to diagnostic laparoscopy only (odds ratio (OR) 1.89, 95% CI 1.25 to 2.86; 3 RCTs, 528 participants; I2 = 0%; moderate quality evidence). We are uncertain of the effect of laparoscopic treatment compared to diagnostic laparoscopy only on ectopic pregnancy (MD 1.18, 95% CI 0.10 to 13.48; 1 RCT, 100 participants; low quality evidence) and miscarriage (MD 0.94, 95% CI 0.35 to 2.54; 2 RCTs, 112 participants; low quality evidence). There was limited reporting of adverse events. No conversions to laparotomy were reported in both groups (1 RCT, 341 participants). Laparoscopic ablation and uterine nerve transection versus diagnostic laparoscopy We are uncertain of the effect of laparoscopic ablation and uterine nerve transection on adverse events (more specifically vascular injury) compared to diagnostic laparoscopy only (OR 0.33, 95% CI 0.01 to 8.32; 1 RCT, 141 participants; low quality evidence). No studies looked at overall pain scores (at six and 12 months), live birth, quality of life, viable intrauterine pregnancy confirmed by ultrasound, ectopic pregnancy and miscarriage. Laparoscopic ablation versus laparoscopic excision There was insufficient evidence to determine whether there was a difference in overall pain, measured at 12 months, for laparoscopic ablation compared with laparoscopic excision (MD 0.00, 95% CI -1.22 to 1.22; 1 RCT, 103 participants; very low quality evidence). No studies looked at overall pain scores at six months, live birth, quality of life, viable intrauterine pregnancy confirmed by ultrasound, ectopic pregnancy, miscarriage and adverse events. Helium thermal coagulator versus electrodiathermy We are uncertain whether helium thermal coagulator compared to electrodiathermy improves quality of life using the 30-item Endometriosis Health Profile (EHP-30) at nine months, when considering the components: pain (MD 6.68, 95% CI -3.07 to 16.43; 1 RCT, 119 participants; very low quality evidence), control and powerlessness (MD 4.79, 95% CI -6.92 to 16.50; 1 RCT, 119 participants; very low quality evidence), emotional well-being (MD 6.17, 95% CI -3.95 to 16.29; 1 RCT, 119 participants; very low quality evidence) and social support (MD 5.62, 95% CI -6.21 to 17.45; 1 RCT, 119 participants; very low quality evidence). Adverse events were not estimable. No studies looked at overall pain scores (at six and 12 months), live birth, viable intrauterine pregnancy confirmed by ultrasound, ectopic pregnancy and miscarriage. AUTHORS' CONCLUSIONS: Compared to diagnostic laparoscopy only, it is uncertain whether laparoscopic surgery reduces overall pain associated with minimal to severe endometriosis. No data were reported on live birth. There is moderate quality evidence that laparoscopic surgery increases viable intrauterine pregnancy rates confirmed by ultrasound compared to diagnostic laparoscopy only. No studies were found that looked at live birth for any of the comparisons. Further research is needed considering the management of different subtypes of endometriosis and comparing laparoscopic interventions with lifestyle and medical interventions. There was insufficient evidence on adverse events to allow any conclusions to be drawn regarding safety.

An explicitly multi-component arterial gas embolus dissolves much more slowly than its one-component approximation.

We worked out the growth and dissolution rates of an arterial gas embolism (AGE), to illustrate the evolution over time of its size and composition, and the time required for its total dissolution. We did this for a variety of breathing gases including air, pure oxygen, Nitrox and Heliox (each over a range of oxygen mole fractions), in order to assess how the breathing gas influenced the evolution of the AGE. The calculations were done by numerically integrating the underlying rate equations for explicitly multi-component AGEs, that contained a minimum of three (water, carbon dioxide and oxygen) and a maximum of five components (water, carbon dioxide, oxygen, nitrogen and helium). The rate equations were straight-forward extensions of those for a one-component gas bubble. They were derived by using the Young-Laplace equation and Dalton's law for the pressure in the AGE, the Laplace equation for the dissolved solute concentration gradients in solution, Henry's law for gas solubilities, and Fick's law for diffusion rates across the AGE/arterial blood interface. We found that the 1-component approximation, under which the contents of the AGE are approximated by its dominant component, greatly overestimates the dissolution rate and underestimates the total dissolution time of an AGE. This is because the 1-component approximation manifestly precludes equilibration between the AGE and arterial blood of the inspired volatile solutes (O2, N2, He) in arterial blood. Our calculations uncovered an important practical result, namely that the administration of Heliox, as an adjunct to recompression therapy for treating a suspected N2-rich AGE must be done with care. While Helium is useful for preventing nitrogen narcosis which can arise in aggressive recompression therapy wherein the N2 partial pressure can be quite high (e.g.∼5 atm), it also temporarily expands the AGE, beyond the expansion arising from the use of Oxygen-rich Nitrox. For less aggressive recompression therapy wherein nitrogen narcosis is not a significant concern, Oxygen-rich Nitrox is to be preferred, both because it does not temporarily expand the AGE as much as Heliox, and because it is much cheaper and more conservation-minded.

Innovative application of helium-neon laser: enhancing the germination of Adansonia digitata and evaluating the hepatoprotective activities in mice.

The laser pretreatment of seed is drawing pronounced attention from the scientific community for its positive impact in boosting germination, seedling , and growth of plants. In this study, the laser pretreatment of Adansonia digitata (A. digitata) seeds was evaluated. Eight laser treatments were conducted at different powers, 10, 20, 40, and 80 mW, with the two-time interval for each power at 2 and 4 min. The outcomes indicated that the most efficient irradiation was 10 mW/2 min which induces the highest germination rate and polyphenolic contents for seeds. Based on these results, the animal experimental design was processed to assess the hepatoprotective activity of A. digitata extracts obtained through the optimum laser preillumination to enhance the resistance of liver damage in mice. The total phenol and flavonoid contents and the antioxidant properties of the methanolic extracts were estimated in vitro. The CCl4 was used to induce hepatotoxicity in mice. The animals were divided into five groups. The sera of the treated animals were used for the determination of transaminases, and the liver homogenates were used for the determination of antioxidant status, and further liver tissues were subjected to verify the anti-apoptotic effect of A. digitata methanolic extract. The in vivo results showed that the methanolic extract exposed to laser treatment at 10 mW/2 min provided better hepatoprotective capacity than the other treatments. Administration of A. digitata extract not only offered a significant decrease in liver enzyme activity but also markedly improved the antioxidant status and reduced the apoptotic progression induced by CCl4 toxicity in liver tissue.

Ultrasensitive Determination of Selenium and Arsenic by Modified Helium Atmospheric Pressure Glow Discharge Optical Emission Spectrometry Coupled with Hydride Generation.

We herein report the development of a compact and robust optical emission spectrometry (OES)-based technique for the ultrasensitive determination of Se and As utilizing hydride generation (HG) as the sampling technique and direct-current atmospheric pressure glow discharge in He (APGD) as the radiation source. The emission sensitivities of 50 ng mL-1 Se and As in the newly designed HG-APGD were enhanced more than 3-fold by constraining the spatial volume between two hollow-tube APGD electrodes, and the stability was significantly improved. The developed technique achieved Se and As detection limits of 0.13 and 0.087 ng mL-1, respectively, with the corresponding relative standard deviations at analyte concentrations of 50 ng mL-1 being <0.5% in both cases. Moreover, the HG-APGD-OES procedure was advantageous in that it exhibited a low power consumption (<17 W) and a low gas consumption (<100 mL min-1). Its accuracy and practicality were also demonstrated by the determination of GBW10024 (scallop) and GBW07381 (stream sediments) certified reference materials and mice blood samples. The results showed good agreement with the certified values and values obtained using inductively coupled plasma-mass spectrometry.

Recent advances in the neuroprotective effects of medical gases.

Central nervous system injuries are a leading cause of death and disability worldwide. Although the exact pathophysiological mechanisms of various brain injuries vary, central nervous system injuries often result in an inflammatory response, and subsequently lead to brain damage. This suggests that neuroprotection may be necessany in the treatment of multiple disease models. The use of medical gases as neuroprotective agents has gained great attention in the medical field. Medical gases include common gases, such as oxygen, hydrogen and carbon dioxide; hydrogen sulphide and nitric oxide that have been considered toxic; volatile anesthetic gases, such as isoflurane and sevoflurane; and inert gases like helium, argon, and xenon. The neuroprotection from these medical gases has been investigated in experimental animal models of various types of brain injuries, such as traumatic brain injury, stroke, subarachnoid hemorrhage, cerebral ischemic/reperfusion injury, and neurodegenerative diseases. Nevertheless, the transition into the clinical practice is still lagging. This delay could be attributed to the contradictory paradigms and the conflicting results that have been obtained from experimental models, as well as the presence of inconsistent reports regarding their safety. In this review, we summarize the potential mechanisms underlying the neuroprotective effects of medical gases and discuss possible candidates that could improve the outcomes of brain injury.

The performance of the (U+Th)/He thermochronology laboratory at UNESP Rio Claro, Brazil.

We have developed the first laboratory for (U-Th-Sm)/He thermochronology measurements in South America. Helium is measured using a high-sensitivity magnetic sector mass spectrometer (GVI-Helix-SFT) and a double focusing single collector inductively coupled plasma mass spectrometer (Thermo Scientific ELEMENT2) is used for U, Th and Sm determinations. Repeated analyses of fragments of Durango fluorapatite crystals yields an average age of 31.6 ± 1.6 Ma (2σ) (n=62). This overlaps the long-term average of Durango fluorapatite measured in laboratories worldwide. The analysis of multiple single apatite crystals of a Precambrian basement sample from Serra do Mar, southeastern Brazil, yields an average He age (60.5 ± 8.7 Ma; n=8) that overlaps that measured in the SUERC laboratory (59.6 ± 3 Ma; n=3). This confirms that the UNESP laboratory is capable of routinely measuring the (U-Th-Sm)/He ages of single apatite crystals.

Use of Helium/Oxygen Mixture in Noninvasive Ventilation During Urgent Tracheotomy for Upper Airway Compression: A Case Report.

Ventilation or oxygenation can be difficult or even impossible in cases of upper airway obstruction. In this case report, we used a helium/oxygen mixture administered via noninvasive positive-pressure ventilation to perform an urgent tracheotomy under local anesthesia on a patient presenting upper airway compression. It improved his comfort and his stridor, facilitating supine positioning. This case describes another potential indication of the helium/oxygen mixture in noninvasive ventilation.

Detection of adulterated drugs in traditional Chinese medicine and dietary supplements using hydrogen as a carrier gas.

Helium, a minor component of natural gas and radioactive minerals, is most commonly used as a carrier in gas chromatography-mass spectrometry (GC-MS). Its scarcity leads to limited availability and higher costs. In this experiment, hydrogen from a safe source of a hydrogen generator was tested as a substitutive carrier gas for the detection of adulterant in traditional Chinese medicine (TCM) and food supplements by GC-MS analysis. We found that the limits of detection (LODs) of using hydrogen were from 10 to 1000 µg/g. The levels of LODs tested among 170 drugs remain the same whether hydrogen or helium was used as a carrier gas with the exception of 7 drugs-benzbromarone, estradiol benzoate, bezafibrate, mefenamic acid, oxymetholone, piperidenafil and cetilistat. The real sample analysis results using hydrogen were as satisfactory as those using helium. In addition, the retention time was shortened after the chromatographic performance was optimized. In summary, it is worth considering hydrogen as a carrier gas due to its affordable costs, energy efficiency, carbon reduction and chromatographic advantages to detect adulterated drugs in TCM and dietary supplement using GC-MS.

Speech-Language Pathology as a Primary Treatment for Exercise-Induced Laryngeal Obstruction.

Exercise-induced laryngeal obstruction is a condition that restricts respiration during exercise via inappropriate glottic or supraglottic obstruction. The literature supports behavioral treatment provided by a speech-language pathologist as an effective means of treating exercise-induced laryngeal obstruction. Treatment includes educating the patient, training on relaxation, instruction on paced exercise, and use of various breathing techniques to optimize laryngeal aperture. Intervention for patients with exercise-induced laryngeal obstruction may be delivered by a speech-language pathologist, given their clinical skill of facilitating long-term behavioral change and expertise in the laryngeal mechanism.

Proof of principle of helium-beam radiography using silicon pixel detectors for energy deposition measurement, identification, and tracking of single ions.

PURPOSE: Hadron therapy has the capability to provide a high dose conformation to tumor regions. However, it requires an accurate target positioning. Thus, the precise monitoring of the patient's anatomical positioning during treatment is desirable. For this purpose, hadron-beam radiography with protons (pRad) and ions (iRad) could be an attractive tool complementing the conventional imaging technologies. On the pathway to an envisaged clinical application, several challenges have to be addressed. Among them are achieving the desired spatial resolution in the presence of multiple Coulomb scattering (MCS), performing radiographs with a sufficient thickness resolution at clinically applicable dose levels, and the search for combinations of particularly suitable hadrons and detectors. These topics are investigated in this work for a detection system based on silicon pixel detectors. METHODS: A method of iRad based on energy deposition measurements in thin layers is introduced. It exploits a detection system consisting of three parallel silicon pixel detectors, which also enables particle tracking and identification. Helium ions, which exhibit less pronounced MCS than protons, were chosen as imaging radiation. A PMMA phantom with a mean water-equivalent thickness (WET) of 192 mm, containing maximal WET-variations of ±6 mm, was imaged with a 173 MeV/u helium ion beam at the Heidelberg Ion-Beam Therapy Center. WET-differences in form of 2.3 mm × 2.3 mm steps were aimed to be visualized and resolved in images of the energy deposition measured behind the phantom. The detection system was placed downstream of the imaged object in order to detect single ions leaving it. The combination of the measured information on energy deposition, ion type, and the track behind the phantom was used for the image formation, employing a self-developed data-processing procedure. RESULTS: It was shown that helium-beam radiography is feasible with the reported detection system. The introduced data preprocessing purified the detector signal from detector artifacts and improved the image quality. Additionally, the rejection of hydrogen ions originating from nuclear interactions was shown to increase the contrast-to-noise ratio (CNR) by at least a factor of 2.5. This enabled the resolution of relative thickness differences of 1.2% at a dose level typical for diagnostic x-ray images. The spatial resolution was improved by taking into account the direction of single helium ions leaving the phantom. A spatial resolution (MTF10% ) of at least 1.15p mm-1 for the presented experimental set-up was achieved. CONCLUSION: A successful feasibility study of helium-beam radiography with the introduced detection system was conducted. The methodology of iRad was based on energy deposition measurements in thin silicon layers. The tracking of single ions and the method of the ion identification was shown to be important for helium-beam radiography in terms of spatial resolution and CNR.

Improvement of Versatility and Analytical Range of AOAC Official Method 2015.06 for Selenium.

AOAC Official Method 2015.06 is not applicable for infant formula without selenium addition because of lack of sensitivity. In addition, Method 2015.06 specifies hydrogen gas as the cell gas of inductively coupled plasma (ICP)-MS instruments. There are only a few manufacturers who have formally adopted hydrogen gas. To expand the applicability of Method 2015.06 for infant formulas with lower selenium content and for ICP-MS instruments that do not use hydrogen gas as the cell gas, we modified the conditions of Method 2015.06. The results exhibited a good linearity (coefficient of determination >0.999) when the range of standard concentration was set from 0.4 to 16.0 µg/L and the cell gas was replaced with helium gas. The measurement precision was improved to an intermediate precision RSD value of 3.49%, and the recovery factor was 103.1%. This study demonstrates that helium gas can be used as the cell gas (easing restrictions in selecting an ICP-MS instrument) and expands the applicability of this method to infant formula samples with lower selenium content by modifying the sample preparation method.

Helium-oxygen mixture: clinical applicability in an intensive care unit / Mistura hélio-oxigênio: aplicabilidade clínica em unidade de terapia intensiva

ABSTRACT Objective To evaluate if distress respiratory decreases after using helium-oxygen mixture in pediatric patients diagnosed with bronchospasm. Methods This is a retrospective, non-randomized study that included patients diagnosed with bronchospasm, who received a helium-oxygen mixture at three time points (30, 60, and 120 minutes) according to the organization protocol singular, and were admitted to the intensive care unit, from January 2012 to December 2013. This protocol includes patients with bronchospasm who sustained a modified Wood score of moderate to severe, even after one hour of conventional treatment. Results Twenty children were included in the study. The mean score of severity of the disease at the initial moment was 5.6 (SD:2.0), and at moment 120 minutes, it was 3.4 (SD: 2.0). The severity score showed a significant improvement as of 30 minutes (p<0.001). Conclusion The use of helium-oxygen mixture proved to be effective in diminishing the respiratory distress score for children with airway obstructions; it should be considered a supplementary therapeutic option, together with drug therapy, in specific clinical situations.

RESUMO Objetivo Avaliar se o desconforto diminui após o uso da mistura hélio-oxigênio em pacientes pediátricos com diagnóstico de broncoespasmo. Métodos Estudo retrospectivo, não randomizado, no qual foram incluídos pacientes com diagnóstico de broncoespasmo que utilizaram a mistura hélio-oxigênio em três momentos (30, 60 e 120 minutos), seguindo o protocolo institucional, internados em unidade de terapia intensiva pediátrica de janeiro de 2012 a dezembro 2013. Este protocolo incluía pacientes com diagnóstico de broncoespasmo que mantivessem escore de Wood modificado de moderado a grave, mesmo após 1 hora de tratamento convencional. Resultados Foram incluídas 20 crianças neste estudo. A média do escore de gravidade da doença no momento zero foi de 5,6 (DP:2,0) e, no momento 120 minutos, 3,4 (DP: 2,0). O escore de gravidade apresentou melhora significante a partir dos 30 minutos (p<0,001). Conclusão A utilização da mistura hélio-oxigênio mostrou-se eficaz na redução do escore de desconforto respiratório de crianças com doenças obstrutivas e deve ser considerada recurso terapêutico complementar à terapia medicamentosa em situações clínicas específicas.

Fast hyperbaric decompression after heliox saturation altered the brain proteome in rats.

Better understanding of the physiological mechanisms and neurological symptoms involved in the development of decompression sickness could contribute to improvements of diving procedures. The main objective of the present study was to determine effects on the brain proteome of fast decompression (1 bar/20 s) compared to controls (1 bar/10 min) after heliox saturation diving, using rats in a model system. The protein S100B, considered a biomarker for brain injury, was not significantly different in serum samples from one week before, immediately after, and one week after the dive. Alterations in the rat brain proteome due to fast decompression were investigated using both iontrap and orbitrap LC-MS, and 967 and 1062 proteins were quantified, respectively. Based on the significantly regulated proteins in the iontrap (56) and orbitrap (128) datasets, the networks "synaptic vesicle fusion and recycling in nerve terminals" and "translation initiation" were significantly enriched in a system biological database analysis (Metacore). Ribosomal proteins (RLA2, RS10) and the proteins hippocalcin-like protein 4 and proteasome subunit beta type-7 were significantly upregulated in both datasets. The heat shock protein 105 kDa, Rho-associated protein kinase 2 and Dynamin-1 were significantly downregulated in both datasets. Another main effect of hyperbaric fast decompression in our experiment is inhibition of endocytosis and stimulation of exocytosis of vesicles in the presynaptic nerve terminal. In addition, fast decompression affected several proteins taking parts in these two main mechanisms of synaptic strength, especially alteration in CDK5/calcineurin are associated with a broad range of neurological disorders. In summary, fast decompression after heliox saturation affected the brain proteome in a rat model for diving, potentially disturbing protein homeostasis, e.g. in synaptic vesicles, and destabilizing cytoskeletal components. Data are available via ProteomeXchange with identifier PXD006349.

Investigation of mixed ion fields in the forward direction for 220.5 MeV/u helium ion beams: comparison between water and PMMA targets.

Currently there is a rising interest in helium ion beams for radiotherapy. For benchmarking of the physical beam models used in treatment planning, there is a need for experimental data on the composition and spatial distribution of mixed ion fields. Of particular interest are the attenuation of the primary helium ion fluence and the build-up of secondary hydrogen ions due to nuclear interactions. The aim of this work was to provide such data with an enhanced precision. Moreover, the validity and limits of the mixed ion field equivalence between water and PMMA targets were investigated. Experiments with a 220.5 MeV/u helium ion pencil beam were performed at the Heidelberg Ion-Beam Therapy Center in Germany. The compact detection system used for ion tracking and identification was solely based on Timepix position-sensitive semiconductor detectors. In comparison to standard techniques, this system is two orders of magnitude smaller, and provides higher precision and flexibility. The numbers of outgoing helium and hydrogen ions per primary helium ion as well as the lateral particle distributions were quantitatively investigated in the forward direction behind water and PMMA targets with 5.2-18 cm water equivalent thickness (WET). Comparing water and PMMA targets with the same WET, we found that significant differences in the amount of outgoing helium and hydrogen ions and in the lateral particle distributions arise for target thicknesses above 10 cm WET. The experimental results concerning hydrogen ions emerging from the targets were reproduced reasonably well by Monte Carlo simulations using the FLUKA code. Concerning the amount of outgoing helium ions, significant differences of 3-15% were found between experiments and simulations. We conclude that if PMMA is used in place of water in dosimetry, differences in the dose distributions could arise close to the edges of the field, in particular for deep seated targets.