Non-randomised phase II trial of hyperbaric oxygen therapy in patients with chronic arm lymphoedema and tissue fibrosis after radiotherapy for early breast cancer

International Nuclear Information System (INIS)

Gothard, Lone; Stanton, Anthony; MacLaren, Julie; Lawrence, David; Hall, Emma; Mortimer, Peter; Parkin, Eileen; Pritchard, Joyce; Risdall, Jane; Sawyer, Robert; Woods, Mary; Yarnold, John

2004-01-01

Background: Radiation-induced arm lymphoedema is a common and distressing complication of curative treatment for early breast cancer. Hyperbaric oxygen (HBO 2 ) therapy promotes healing in bone rendered ischaemic by radiotherapy, and may help some soft-tissue injuries too, but is untested in arm lymphoedema. Methods: Twenty-one eligible research volunteers with a minimum 30% increase in arm volume in the years after axillary/supraclavicular radiotherapy (axillary surgery in 18/21 cases) were treated with HBO 2 . The volunteers breathed 100% oxygen at 2.4 ATA for 100 min in a multiplace hyperbaric chamber on 30 occasions over a period of 6 weeks. The volume of the ipsilateral limb, measured opto-electronically by a perometer and expressed as a percentage of contralateral limb volume, was selected as the primary endpoint. A secondary endpoint was local lymph drainage expressed as fractional removal rate of radioisotopic tracer, measured using lymphoscintigraphy. Results: Three out of 19 evaluable patients experienced >20% reduction in arm volume at 12 months. Six out of 13 evaluable patients experienced a >25% improvement in 99 Tc-nanocolloid clearance rate from the ipsilateral forearm measured by quantitative lymphoscintigraphy at 12 months. Overall, there was a statistically significant, but clinically modest, reduction in ipsilateral arm volume at 12 months follow-up compared with baseline (P=0.005). The mean percentage reduction in arm volume from baseline at 12 months was 7.51. Moderate or marked lessening of induration in the irradiated breast, pectoral fold and/or supraclavicular fossa was recorded clinically in 8/15 evaluable patients. Twelve out of 19 evaluable patients volunteered that their arms felt softer, and six reported improvements in shoulder mobility at 12 months. No significant improvements were noted in patient self-assessments of quality of life. Conclusion: Interpretation is limited by the absence of a control group. However, measurement of

Safety and Tolerability of Hyperbaric Oxygen Therapy in Cats and Dogs.

Science.gov (United States)

Birnie, Gemma L; Fry, Darren R; Best, Matthew P

2018-05-14

This prospective clinical trial was designed to evaluate the safety of hyperbaric oxygen therapy (HBOT) in a population of cats and dogs with a variety of naturally occurring diseases. Seventy-eight dogs and twelve cats with various naturally occurring disease conditions, who had the potential to benefit from HBOT, were enrolled in the study. These patients were treated with HBOT in a monoplace hyperbaric oxygen chamber at 2 air pressure absolute for a treatment length of either 45 min or 60 min. There were 230 hyperbaric oxygen treatments performed during the study period. No major adverse effects were observed. There were 76 minor adverse effects recorded, which were not considered to be of clinical significance. Hyperbaric oxygen therapy was well tolerated and there were no major adverse effects recorded during treatment.

Hyperbaric oxygen - an effective tool to treat radiation morbidity in prostate cancer

International Nuclear Information System (INIS)

Mayer, Ramona; Klemen, Huberta; Quehenberger, Franz; Sankin, Oliver; Mayer, Elisabeth; Hackl, Arnulf; Smolle-Juettner, Freyja-Maria

2001-01-01

Purpose: We report the results of hyperbaric oxygen therapy (HBO) used in the treatment of radiation cystitis and proctitis following irradiation of prostate cancer. Materials and methods: Between June 1995 and March 2000, 18 men (median age 71 years) with radiation proctitis (n=7), cystitis (n=8), and combined proctitis/cystitis (n=3) underwent HBO therapy in a multiplace chamber for a median of 26 sessions (range 2-60). The treatment schedule (2.2-2.4 atmospheres absolute, 60 min bottom time, once-a-day, 7 days a week) was set at a lower limit of 20 sessions; the upper limit was left open to symptom-related adjustment. Prior to HBO treatment, RTOG/EORTC late genitourinal (GU) morbidity was Grade 2 (n=3), Grade 3 (n=6) or Grade 4 (n=2); modified RTOG/EORTC late gastrointestinal (GI) morbidity was either Grade 2 (n=4) or Grade 3 (n=6). Results: Sixteen patients underwent an adequate number of sessions. RTOG/EORTC late GU as well as modified GI morbidity scores showed a significant improvement after HBO (GI, P=0.004; GU, P=0.004; exact Wilcoxon signed rank test); bleeding ceased in five out of five patients with proctitis and in six out of eight patients with cystitis; one of those two patients, in whom an ineffective treatment outcome was obtained, went on to have a cystectomy. Conclusions: HBO treatment seems to be an effective tool to treat those patients with late GI and GU morbidity when conventional treatment has led to unsatisfactory results. Particularly in patients with radiation cystitis, HBO should not be delayed too long, as in the case of extensive bladder shrinkage improvement is hard to achieve

[Characterizing the passive opening of the eustachian tube in a hypo-/hyperbaric pressure chamber].

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Meyer, M F; Mikolajczak, S; Luers, J C; Lotfipour, S; Beutner, D; Jumah, M D

2013-09-01

Beside arbitrary and not arbitrary active pressure equalization systems there is a passive equalization system via the Eustachian tube (ET) at pressure difference between the epipharyngeal space and the middle ear. Aim of this study was to characterize this passive equalization system in a hypobaric/hyperbaric pressure chamber by continuously measuring the tympanic impedance. In contrast to other studies, which are measured only in a hypobaric pressure chamber it is possible to include participants with Eustachian tube dysfunction (ETD). Following a fixed pressure profile 39 participants were exposed to phases of pressure rising and decompression. By continuously measuring the tympanic impedance in the pressure chamber it was possible to measure data of the Eustachian Tube opening Pressure (ETOP), Eustachian Tube closing pressure (ETCP) and Eustachian Tube opening duration (ETOD). In addition it was possible to characterize the gradient of pressure during decompression, while the ET was open. Beside the measurement of the arithmetic average of the ETOP (30.2 ± 15.1 mbar), ETCP (9.1 ± 7.7 mbar) and ETOD (0.65 ± 0.38 s) it was obvious that there are recurrent samples of pressure progression during the phase of tube opening. Generally it is possible to differentiate between the type of complete opening and partial opening. The fundamental characterization of the action of the passive tube opening, including the measurement of the ETOP, ETCP and ETOD, is a first step in understanding the physiological and pathophysiological function of the ET. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of hyperbaric treatment in cerebral air embolism on intracranial pressure, brain oxygenation, and brain glucose metabolism in the pig

NARCIS (Netherlands)

van Hulst, Robert A.; Drenthen, Judith; Haitsma, Jack J.; Lameris, Thomas W.; Visser, Gerhard H.; Klein, Jan; Lachmann, Burkhard

2005-01-01

OBJECTIVE: To evaluate the effects of hyperbaric oxygen treatment after cerebral air embolism on intracranial pressure, brain oxygenation, brain glucose/lactate metabolism, and electroencephalograph. DESIGN: Prospective animal study. SETTING: Hyperbaric chamber. SUBJECTS: Eleven Landrace/Yorkshire

Hyperbaric oxygen and wound healing

Directory of Open Access Journals (Sweden)

Sourabh Bhutani

2012-01-01

Full Text Available Hyperbaric oxygen therapy (HBOT is the use of 100% oxygen at pressures greater than atmospheric pressure. Today several approved applications and indications exist for HBOT. HBOT has been successfully used as adjunctive therapy for wound healing. Non-healing wounds such as diabetic and vascular insufficiency ulcers have been one major area of study for hyperbaric physicians where use of HBOT as an adjunct has been approved for use by way of various studies and trials. HBOT is also indicated for infected wounds like clostridial myonecrosis, necrotising soft tissue infections, Fournier′s gangrene, as also for traumatic wounds, crush injury, compartment syndrome, compromised skin grafts and flaps and thermal burns. Another major area of application of HBOT is radiation-induced wounds, specifically osteoradionecrosis of mandible, radiation cystitis and radiation proctitis. With the increase in availability of chambers across the country, and with increasing number of studies proving the benefits of adjunctive use for various kinds of wounds and other indications, HBOT should be considered in these situations as an essential part of the overall management strategy for the treating surgeon.

The influence of a hyperbaric environment and increased oxygen partial pressure on the corrosion of dental alloys.

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Mehl, Christian; Heblich, Frank; Lenz, Rudolf; Ludwig, Klaus; Kern, Matthias

2011-09-01

The purpose of this in-vitro study was to determine whether there is a correlation between a hyperbaric environment or increased oxygen partial pressure and the corrosion of dental alloys used for dental restorations in divers. Samples of three commercially available dental alloys (palladium-based, reduced-gold-content and high-gold-content) were tested in the DIN EN ISO 1562 static immersion test and the amount of dissolved ions measured by atomic absorption spectrometry. The specimens were exposed to one of the following three conditions: normobaric and normoxic conditions (PO2 21 kPa); 608 kPa (6 bar, PO2 127 kPa) pressurised air in a pressure chamber or 506 kPa (5 bar, PO2 304 kPa) pressurised nitrox in a pressure chamber. None of the exposures suggested a correlation between increased ion solubility as a measure of corrosion and increased ambient pressure of the three alloys. The reduced-gold-content alloy released zinc ions at twice the weekly recommended dose. When the palladium-based alloy was exposed to a hyperbaric or hyperbaric/hyperoxic environment, ion solubility increased only slightly for gallium and silver. Within the limited sample size of the current study it can be concluded that hyperbaric and/or hyperoxic conditions do not seem to be a risk for increased corrosion for any of the three tested alloys.

Report from Workshop on VOCs in diving chambers

International Nuclear Information System (INIS)

Crosbie, A.; Simpson, M.

2000-05-01

This report of the 'Setting the Standards' workshop on the problems of volatile organic compounds (VOCs) in diving in offshore operations, sponsored jointly by the UK Health and Safety Executive Offshore Safety Division and the Stolt Rockwater Joint Venture, gives details of the papers presented covering the chemical contamination of diver's atmosphere, sampling protocols and methods, analytical procedures used for VOCs in hyperbaric chambers, and contamination in buildings. The setting of exposure limits in the UK, the derivation of threshold limiting values (TVLs), the selection of Tenax tubes for atmospheric sampling, organic contaminant monitoring, and NASA's approach to contamination in the space environment are examined, and dealing with contamination problems in a submarine atmosphere, and the simulation of a condensate spillage in a diving bell are discussed. Guidelines for the measurement of VOCs in hyperbaric chambers are given in the appendices

Continuous glucose monitoring--a study of the Enlite sensor during hypo- and hyperbaric conditions.

Science.gov (United States)

Adolfsson, Peter; Örnhagen, Hans; Eriksson, Bengt M; Cooper, Ken; Jendle, Johan

2012-06-01

The performance and accuracy of the Enlite(™) (Medtronic, Inc., Northridge, CA) sensor may be affected by microbubble formation at the electrode surface during hypo- and hyperbaric conditions. The effects of acute pressure changes and of prewetting of sensors were investigated. On Day 1, 24 sensors were inserted on the right side of the abdomen and back in one healthy individual; 12 were prewetted with saline solution, and 12 were inserted dry. On Day 2, this procedure was repeated on the left side. All sensors were attached to an iPro continuous glucose monitoring (CGM) recorder. Hypobaric and hyperbaric tests were conducted in a pressure chamber, with each test lasting 105 min. Plasma glucose values were obtained at 5-min intervals with a HemoCue(®) (Ängelholm, Sweden) model 201 glucose analyzer for comparison with sensor glucose values. Ninety percent of the CGM systems operated during the tests. The mean absolute relative difference was lower during hyperbaric than hypobaric conditions (6.7% vs. 14.9%, Phypobaric but not during hyperbaric conditions. Clarke Error Grid Analysis showed that 100% of the values were found in the A+B region. No differences were found between prewetted and dry sensors. The Enlite sensor performed adequately during acute pressure changes and was more accurate during hyperbaric than hypobaric conditions. Prewetting the sensors did not improve accuracy. Further studies on type 1 diabetes subjects are needed under various pressure conditions.

Hyperbaric oxygen treatment in radiation reactions; Hyperbar oksygenbehandling ved straalereaksjoner

Energy Technology Data Exchange (ETDEWEB)

Aanderud, Leif; Thorsen, Einar; Bratteboe, Guttorm; Forland, Martha; Kristensen, Gunnar

2000-07-01

Background: A national hyperbaric centre was established in 1994 at Haukeland Hospital with responsibility of all hyperbaric oxygen (HBO) treatment in Norway. In hypoxic tissues with symptomatic radiation reactions, hyperbaric oxygen induces the formation of collagen and angiogenesis resulting in permanently improved local microcirculation. Material and method: 234 patients received elective HBO treatment at Haukeland Hospital in 12997 with total of 4048 treatments. All 47 patients treated for radiation reactions in the pelvic area in 1997 received a questionnaire 3-15 months after HBO therapy, 81% reported. Results: Rectal bleeding and haematuria were reported as much improved in 61% and 55% respectively, while bladder incontinence was much improved in 46%. Interpretation: this treatment modality may be an alternative in symptomatic radiation reactions at the urinary bladder and the bowel when conventional treatment has given unsatisfactory results.

Characterizing the active opening of the eustachian tube in a hypobaric/hyperbaric pressure chamber.

Science.gov (United States)

Mikolajczak, Stefanie; Meyer, Moritz Friedo; Hahn, Moritz; Korthäuer, Christine; Jumah, Masen Dirk; Hüttenbrink, Karl-Bernd; Grosheva, Maria; Luers, Jan Christoffer; Beutner, Dirk

2015-01-01

Active and passive opening of the Eustachian tube (ET) enables direct aeration of the middle ear and a pressure balance between middle ear and the ambient pressure. The aim of this study was to characterize standard values for the opening pressure (ETOP), the opening frequency (ETOF), and the opening duration (ETOD) for active tubal openings (Valsalva maneuver, swallowing) in healthy participants. In a hypobaric/hyperbaric pressure chamber, 30 healthy participants (19 women, 11 men; mean age, 25.57 ± 3.33 years) were exposed to a standardized profile of compression and decompression. The pressure values were recorded via continuous impedance measurement during the Valsalva maneuver and swallowing. Based on the data, standard curves were identified and the ETOP, ETOD, and ETOF were determined. Recurring patterns of the pressure curve during active tube opening for the Valsalva maneuver and for active swallowing were characterized. The mean value for the Valsalva maneuver for ETOP was 41.21 ± 17.38 mbar; for the ETOD, it was 2.65 ± 1.87 seconds. In the active pressure compensation by swallowing, the mean value for the ETOP was 29.91 ± 13.07 mbar; and for the ETOD, it was 0.82 ± 0.53 seconds. Standard values for the opening pressure of the tube and the tube opening duration for active tubal openings (Valsalva maneuver, swallowing) were described, and typical curve gradients for healthy subjects could be shown. This is another step toward analyzing the function of the tube in compression and decompression.

[Hyperbaric oxygen treatment of musculoskeletal disorders on the sports medicine. State of the art].

Science.gov (United States)

Drobnic, Franchek; Turmo, Antonio

2010-03-13

Hyperbaric oxygen therapy (OHB) is a therapeutic modality based on the properties of partial pressure of oxygen, when breathing pure oxygen under hyperbaric conditions in a chamber designed for that purpose. Its indications in medicine are considered as primary, complementary or experimental depending on the evidence based effects. From different sectors of medicine, OHB has been recently proposed as a new tool for other pathologies, primarily in musculoskeletal disorders. In this paper, the state of the art of the influence from experimental studies is reviewed. Some considerations based on these studies are hypothesized as the minimum required to obtain good results when this therapy is decided to be used as co adjuvant to standard treatment. Copyright 2009 Elsevier España, S.L. All rights reserved.

Oxygenation measurements in head and neck cancers during hyperbaric oxygenation

International Nuclear Information System (INIS)

Becker, A.; Kuhnt, T.; Dunst, J.; Liedtke, H.; Krivokuca, A.; Bloching, M.

2002-01-01

Background: Tumor hypoxia has proven prognostic impact in head and neck cancers and is associated with poor response to radiotherapy. Hyperbaric oxygenation (HBO) offers an approach to overcome hypoxia. We have performed pO 2 measurements in selected patients with head and neck cancers under HBO to determine in how far changes in the oxygenation occur and whether a possible improvement of oxygenation parameters is maintained after HBO. Patients and Methods: Seven patients (five male, two female, age 51-63 years) with squamous cell cancers of the head and neck were investigated (six primaries, one local recurrence). The median pO 2 prior to HBO was determined with the Eppendorf histograph. Sites of measurement were enlarged cervical lymph nodes (n = 5), the primary tumor (n = 1) and local recurrence (n = 1). Patients then underwent HBO (100% O 2 at 240 kPa for 30 minutes) and the continuous changes in the oxygenation during HBO were determined with a Licox probe. Patients had HBO for 30 minutes (n = 6) to 40 minutes (n = 1). HBO was continued because the pO 2 had not reached a steady state after 30 minutes. After decompression, patients ventilated pure oxygen under normobaric conditions and the course of the pO 2 was further measured over about 15 minutes. Results: Prior to HBO, the median tumor pO 2 in the Eppendorf histography was 8.6 ± 5.4 mm Hg (range 3-19 mm Hg) and the pO 2 measured with the Licox probe was 17.3 ± 25.5 mm Hg (range 0-73 mm Hg). The pO 2 increased significantly during HBO to 550 ± 333 mm Hg (range 85-984 mm Hg, p = 0.018). All patients showed a marked increase irrespective of the oxygenation prior to HBO. The maximum pO 2 in the tumor was reached after 10-33 minutes (mean 17 minutes). After leaving the hyperbaric chamber, the pO 2 was 282 ± 196 mm Hg. All patients maintained an elevated pO 2 for further 5-25 minutes (138 ± 128 mm Hg, range 42-334 mm Hg, p = 0.028 vs the pO 2 prior to HBO). Conclusions: Hyperbaric oxygenation resulted in a

Assessment of the radiation burden of persons involved in the treatment of paediatric patients with neuroblastoma by means of 131I-MIBG in combination with hyperbaric oxygen therapy

International Nuclear Information System (INIS)

Hermanska, J.; Zimak, J.; Krizova, H.; Vlcek, P.; Dosel, P.; Paskova, Z.

2002-01-01

The dose equivalents to the parents, the drivers transporting the patients to oxygen therapy, and the hyperbaric chamber operating personnel were evaluated. The surface contamination of the oxygen chamber and masks and the contamination of the ambulances were also measured. The dose equivalents to the family members over the entire treatment period did not exceed 5 mSv. The dose equivalents received by the drivers and hyperbaric chamber personnel did not exceed the natural background level. No surface contamination was ever detected. It is recommended that the monitoring of the drivers and oxygen chamber personnel be dropped, whereas monitoring of the parents be continued in view of the high probability of repeated therapy. Surface contamination measurement is necessary because this risk can never be ruled out. Care of the patient during transport, as well as potential decontamination, could be the responsibility of a duly instructed and trained nurse

Rectal temperature changes and oxygen toxicity in dogs treated in a monoplace chamber.

Science.gov (United States)

Shmalberg, Justin; Davies, Wendy; Lopez, Stacy; Shmalberg, Danielle; Zilberschtein, Jose

2015-01-01

Hyperbaric oxygen treatments are increasingly administered to pet dogs, using veterinary-specific monoplace chambers. The basic physiologic responses, chamber performance and oxygen toxicity rates have not yet been evaluated in dogs in a clinical setting. As a result, a series of consecutive 45-minute, 2-atmospheres absolute (atm abs) hyperbaric treatments with 100% oxygen were evaluated in a veterinary rehabilitation center (n = 285). 65 dogs with a mean body weight of 21 ± 15 kg (1.4-71 kg) were treated with an average of four sessions each. The mean rectal temperature of canine patients decreased 0.07 degrees C (0.1 degrees F) during treatments (p = 0.04). Intra-chamber temperature and humidity both increased: +1.0 degrees C (1.7 degrees F, p 0.75) were identified between body weights, body condition scores, maximal oxygen concentrations, starting or ending rectal temperature, chamber humidity and chamber temperature. Oxygen toxicity was not observed during the observational period. Patients were most commonly treated for intervertebral disc disease (n = 16 dogs) and extensive traumatic wounds (n = 10 dogs), which represented a large number of the total study sessions (19% and 16%, respectively).

The Relevance of Hyperbaric Oxygen to Combat Medicine

Science.gov (United States)

2001-06-01

and Hyperbaric Conditions [les Questions medicales a caractere oprationel liees aux conditions hypobares ou hyperbares ] To order the complete...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO 11081 TITLE: The Relevance of Hyperbaric Oxygen to Combat Medicine...following component part numbers comprise the compilation report: ADPO11059 thru ADP011100 UNCLASSIFIED 25-1 The Relevance of Hyperbaric Oxygen to

The selection of skin care products for use in hyperbaric chamber may depend on flammability acceptability indices score.

Science.gov (United States)

McCord, Darlene E; Newton, Barry E; Fore, Jane; Chiffoleau, Gwenael

2008-02-01

Current protocols call for stopping adjunctive skin care treatments during hyperbaric oxygen therapy (HBOT) because the hyperbaric environment is considered unsafe for skin care products. The elevated oxygen fraction and the increased pressure in the hyperbaric chamber dramatically increase the flammability potential of materials, leading to the need for rigorous standards to prevent flame ignition. A scientific method of evaluating the flammability risks associated with skin care products would be helpful. Several skin care products were tested, using established industrial techniques for determining flammability potential with some modification. The information obtained from these tests can help clinicians make more rational decisions about which topical products can be used safely on patients undergoing HBOT. Wendell Hull & Associates conducted independent studies, comparing the oxygen compatibility for leading skin care products. Oxygen compatibility was determined using autogenous ignition temperature (AIT), oxygen index (OI), and heat of combustion (HoC) testing. AIT, a relative indication of a material's propensity for ignition, is the minimum temperature needed to cause a sample to self-ignite at a given pressure and oxygen concentration. OI, a relative indication of a material's flammability, is the minimum oxygen percentage that, when mixed with nitrogen, will sustain burning. HoC is the absolute value of a material's energy release when burning, if ignition occurs. Products with a high AIT, a high OI, and a low HoC are more compatible in an oxygen-enriched atmosphere (OEA). An acceptability index (AI) based on these 3 factors was calculated for the products, so the testers could rank overall material compatibility in OEAs (Lapin A. Oxygen Compatibility of Materials. International Institute of Refrigeration Commission Meeting; Brighton, England; 1973). Test results for the skin products varied widely. The AIT, OI, HoC, and AI were determined for each

Hyperbaric spinal ropivacaine in lower limb and hip surgery: A comparison with hyperbaric bupivacaine

Directory of Open Access Journals (Sweden)

Feroz Ahmad Dar

2015-01-01

Conclusion: We conclude that hyperbaric bupivacaine used intrathecally has a faster onset of sensory block and prolonged duration of analgesia compared to hyperbaric ropivacaine group. A more rapid postoperative recovery of sensory and motor function was seen in Group R compared with Group B. However, side effects observed were more in Group B.

Hyperbaric pressure effects measured by growth of a transplantable tumor in the C3H/HeN mouse.

Science.gov (United States)

Herndon, B L; Lally, J J

1984-09-01

Both hypobaric exposure at 0.5 atmospheres absolute (ATA) and hyperbaric pressure exposure at 3.5-8 ATA slowed transplantable tumor growth. These experiments detailed the hyperbaric pressure exposure. C3H/HeN-MTV+ mice, bearing the 16/C transplantable murine mammary adenocarcinoma and exposed to 18 days' treatment by a hyperbaric chamber at 3.5-8 ATA, had tumor weights that averaged 50-75% less than the tumor weights in mice caged at ambient ("sea level") pressure. A series of experiments was run to investigate this response to hyperbaric pressure exposure. After mice underwent continuous exposure to 3.5-8 ATA normoxic (normal oxygen) hyperbaric pressure with use of either argon or nitrogen inert gas, which began 3 days after tumor inoculation, tumors were removed at about 3 weeks' growth from these pressure-exposed mice and measured for growth by weighing. Final tumor weight in pressure-exposed experimental mice was significantly less than tumor weight in paired groups of tumor-bearing controls that received no hyperbaric pressure. Tumor weight was inversely related to pressure "dose," although the small pressure range produced an effect at all pressures used. The number of compression-decompression cycles to which the animals were subjected, however, was related positively to tumor weight at necropsy. Continued tumor growth in mice subjected to frequent pressure change (in conjunction with pressure exposure that otherwise limited tumor size) was unexplained by these experiments. The greatest difference between tumor weights in controls and pressure-exposed animals was seen with 2 weeks' continuous pressure exposure. A limited profile of blood tests was performed, and these reflected only minor, expected change in the pressure-exposed experimental animals. The data at hand did not suggest a mechanism by which chronic normoxic hyperbaric pressure limited tumor size.

Venturi vacuum systems for hypobaric chamber operations.

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Robinson, R; Swaby, G; Sutton, T; Fife, C; Powell, M; Butler, B D

1997-11-01

Physiological studies of the effects of high altitude on man often require the use of a hypobaric chamber to simulate the reduced ambient pressures. Typical "altitude" chambers in use today require complex mechanical vacuum systems to evacuate the chamber air, either directly or via reservoir system. Use of these pumps adds to the cost of both chamber procurement and maintenance, and service of these pumps requires trained support personnel and regular upkeep. In this report we describe use of venturi vacuum pumps to perform the function of mechanical vacuum pumps for human and experimental altitude chamber operations. Advantages of the venturi pumps include their relatively low procurement cost, small size and light weight, ease of installation and plumbing, lack of moving parts, and independence from electrical power sources, fossil fuels and lubricants. Conversion of three hyperbaric chambers to combined hyper/hypobaric use is described.

Decompression sickness among diving fishermen in Mexico: observational retrospective analysis of DCS in three sea cucumber fishing seasons.

Science.gov (United States)

Huchim-Lara, Oswaldo; Chin, Walter; Salas, Silvia; Rivera-Canul, Normando; Cordero-Romero, Salvador; Tec, Juan; Joo, Ellie; Mendez-Dominguez, Nina

2017-01-01

The probabilities of decompression sickness (DCS) among diving fishermen are higher than in any other group of divers. Diving behavior of artisanal fishermen has been directed mainly to target high-value species. The aim of this study was to learn about the occurrence of DCS derived from sea cucumber harvesting in the Yucatán Peninsula, Mexico. We conducted a retrospective chart review of diving fishermen treated at a multiplace hyperbaric chamber in Tizimín, Mexico. In total, 233 recompression therapies were rendered to 166 diving fishermen from 2014 to 2016. The average age was 36.7 ± 9.2 years (range: 20-59 years); 84.3% had experienced at least one DCS event previously. There was a correlation between age and DCS incidents (F: 8.3; R2: 0.07) and differences in the fishing depth between seasons (H: 9.99; p⟨0.05). Musculoskeletal pain was the most frequently reported symptom. Three divers, respectively, suffered permanent hearing loss, spinal cord injury and fatal outcome. Diving fishermen experience DCS at an alarmingly high rate, probably due to the type of species targeted, given the requirements in each case. Understanding divers' behaviors and their incentives while in pursuit of high-value species such as sea cucumber could help to find ways to mitigate health risks and help enforce regulation. Copyright© Undersea and Hyperbaric Medical Society.

Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance.

Science.gov (United States)

Vadas, Dor; Kalichman, Leonid; Hadanny, Amir; Efrati, Shai

2017-01-01

Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, multitasking), the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO) environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities. Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking). Participants were randomized to perform the tasks in two environments: (a) normobaric air (1 ATA 21% oxygen) (b) HBO (2 ATA 100% oxygen). Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance. Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment ( p Multitasking performance was also significantly enhanced in HBO environment ( p = 0.006 for the cognitive part and p = 0.02 for the motor part). Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance.

Hyperbaric oxygen treatment for radiation proctitis

International Nuclear Information System (INIS)

Woo, Tony Choon Seng; Joseph, David; Oxer, Harry

1997-01-01

Purpose: Our objective was to assess, retrospectively, the efficacy of hyperbaric oxygen treatment in radiation proctitis in all patients who have completed treatment for this disease at the Fremantle Hyperbaric Oxygen Unit. This unit is the only one of its kind in Western Australia. Methods and Materials: Patients were assessed by a review of hospital records, blood bank records, and clinic review (if this was convenient), and all patients responded to a telephone survey. Patients were questioned regarding radiation proctitis symptoms and the degree to which each had improved. Results: Most patients had previously been treated with radiotherapy for prostate carcinoma. Patients with proctitis mainly suffered from bleeding, diarrhoea, incontinence, and pain. In more than half of these patients, symptoms partially or completely resolved after hyperbaric oxygen treatment. Conclusion: Radiation-induced proctitis is a difficult clinical problem to treat and will probably become more significant with the rising incidence of diagnosis of prostate cancer. Hyperbaric Oxygen should be considered in the treatment of radiation-induced proctitis. Further prospective trials with strict protocol guidelines are warranted

Hyperbaric Oxygen Environment Can Enhance Brain Activity and Multitasking Performance

Directory of Open Access Journals (Sweden)

Dor Vadas

2017-09-01

Full Text Available Background: The Brain uses 20% of the total oxygen supply consumed by the entire body. Even though, <10% of the brain is active at any given time, it utilizes almost all the oxygen delivered. In order to perform complex tasks or more than one task (multitasking, the oxygen supply is shifted from one brain region to another, via blood perfusion modulation. The aim of the present study was to evaluate whether a hyperbaric oxygen (HBO environment, with increased oxygen supply to the brain, will enhance the performance of complex and/or multiple activities.Methods: A prospective, double-blind randomized control, crossover trial including 22 healthy volunteers. Participants were asked to perform a cognitive task, a motor task and a simultaneous cognitive-motor task (multitasking. Participants were randomized to perform the tasks in two environments: (a normobaric air (1 ATA 21% oxygen (b HBO (2 ATA 100% oxygen. Two weeks later participants were crossed to the alternative environment. Blinding of the normobaric environment was achieved in the same chamber with masks on while hyperbaric sensation was simulated by increasing pressure in the first minute and gradually decreasing to normobaric environment prior to tasks performance.Results: Compared to the performance at normobaric conditions, both cognitive and motor single tasks scores were significantly enhanced by HBO environment (p < 0.001 for both. Multitasking performance was also significantly enhanced in HBO environment (p = 0.006 for the cognitive part and p = 0.02 for the motor part.Conclusions: The improvement in performance of both single and multi-tasking while in an HBO environment supports the hypothesis which according to, oxygen is indeed a rate limiting factor for brain activity. Hyperbaric oxygenation can serve as an environment for brain performance. Further studies are needed to evaluate the optimal oxygen levels for maximal brain performance.

Acquiring the optimal time for hyperbaric therapy in the rat model of CFA induced arthritis.

Science.gov (United States)

Koo, Sung Tae; Lee, Chang-Hyung; Shin, Yong Il; Ko, Hyun Yoon; Lee, Da Gyo; Jeong, Han-Sol

2014-01-01

We previously published an article about the pressure effect using a rheumatoid animal model. Hyperbaric therapy appears to be beneficial in treating rheumatoid arthritis (RA) by reducing the inflammatory process in an animal model. In this sense, acquiring the optimal pressure-treatment time parameter for RA is important and no optimal hyperbaric therapy time has been suggested up to now. The purpose of our study was to acquire the optimal time for hyperbaric therapy in the RA rat model. Controlled animal study. Following injection of complete Freund's adjuvant (CFA) into one side of the knee joint, 32 rats were randomly assigned to 3 different time groups (1, 3, 5 hours a day) under 1.5 atmospheres absolute (ATA) hyperbaric chamber for 12 days. The pain levels were assessed daily for 2 weeks by weight bearing force (WBF) of the affected limb. In addition, the levels of gelatinase, MMP-2, and MMP-9 expression in the synovial fluids of the knees were analyzed. The reduction of WBF was high at 2 days after injection and then it was spontaneously increased up to 14 days in all 3 groups. There were significant differences of WBF between 5 hours and control during the third through twelfth days, between 3 hours and control during the third through fifth and tenth through twelfth days, and between 3 hours and 5 hours during the third through seventh days (P CFA injection in all groups compared to the initial findings, however, the 3 hour group showed a smaller MMP-9/MMP-2 ratio than the control group. Although enough samples were used for the study to support our hypothesis, more samples will be needed to raise the validity and reliability. The effect of hyperbaric treatment appears to be dependent upon the elevated therapy time under 1.5 ATA pressure for a short period of time; however, the long-term effects were similar in all pressure groups. Further study will be needed to acquire the optimal pressure-treatment parameter relationship in various conditions for

Type II decompression sickness in a hyperbaric inside attendant.

Science.gov (United States)

Johnson-Arbor, Kelly

2012-01-01

Decompression sickness (DCS) of an inside attendant (IA) is rarely encountered in hyperbarics. This report describes an IA who developed Type II DCS after a routine hyperbaric exposure. A 50-year-old male complained of lower extremity weakness and paresthesias after serving as an IA during a hyperbaric treatment to 40 fsw (122.52 kPa). Within 10 minutes after the conclusion of the treatment, the IA experienced irritability and confusion, and was unable to walk. Physical examination revealed decreased sensation below the T7 level, and decreased strength in the lower extremities. Type II DCS was diagnosed, and the IA was recompressed to 60 fsw (183.78 kPa) on a U.S. Navy Treatment Table 6, which resulted in improvement of his symptoms. Transthoracic echocardiography with bubble study performed 16 months after the event demonstrated a large patent foramen ovale (PFO). Increased age, decreased physical fitness and the undiagnosed PFO may have predisposed this attendant to developing DCS. Although rare, DCS may occur in IAs. Routine monitoring and reporting of the long-term health of hyperbaric IAs should be considered by hyperbaric facilities and medical directors in order to further understand the characteristics of DCS and other hyperbaric-related conditions in these workers.

Novel liquid chromatography method based on linear weighted regression for the fast determination of isoprostane isomers in plasma samples using sensitive tandem mass spectrometry detection.

Science.gov (United States)

Aszyk, Justyna; Kot, Jacek; Tkachenko, Yurii; Woźniak, Michał; Bogucka-Kocka, Anna; Kot-Wasik, Agata

2017-04-15

A simple, fast, sensitive and accurate methodology based on a LLE followed by liquid chromatography-tandem mass spectrometry for simultaneous determination of four regioisomers (8-iso prostaglandin F 2α , 8-iso-15(R)-prostaglandin F 2α , 11β-prostaglandin F 2α , 15(R)-prostaglandin F 2α ) in routine analysis of human plasma samples was developed. Isoprostanes are stable products of arachidonic acid peroxidation and are regarded as the most reliable markers of oxidative stress in vivo. Validation of method was performed by evaluation of the key analytical parameters such as: matrix effect, analytical curve, trueness, precision, limits of detection and limits of quantification. As a homoscedasticity was not met for analytical data, weighted linear regression was applied in order to improve the accuracy at the lower end points of calibration curve. The detection limits (LODs) ranged from 1.0 to 2.1pg/mL. For plasma samples spiked with the isoprostanes at the level of 50pg/mL, intra-and interday repeatability ranged from 2.1 to 3.5% and 0.1 to 5.1%, respectively. The applicability of the proposed approach has been verified by monitoring of isoprostane isomers level in plasma samples collected from young patients (n=8) subjected to hyperbaric hyperoxia (100% oxygen at 280kPa(a) for 30min) in a multiplace hyperbaric chamber. Copyright © 2017 Elsevier B.V. All rights reserved.

United States Air Force Analysis Extract. AFSC 4M0X1 Aerospace Physiology (Active Duty)

Science.gov (United States)

2002-05-01

Perform NCOIC duties during hyperbaric chamber dives 12.50 1.46 .18 76.76 A0004 Maintain hypobaric chamber...during hyperbaric 58.33 1.04 .61 35.39 chamber dives A0003 Maintain hypobaric chamber...8 % 2 % Hyperbaric Chamber Technician 9 % 3 % 6 % 13 % 8 % Hypobaric Chamber Technician

Hyperbaric oxygen and radiotherapy

International Nuclear Information System (INIS)

Mayer, R.; Hamilton-Farrell, M.R.; Kleij, A.J. van der

2005-01-01

Background: Hyperbaric oxygen (HBO) therapy is the inhalation of 100% oxygen at a pressure of at least 1.5 atmospheres absolute (150 kPa). It uses oxygen as a drug by dissolving it in the plasma and delivering it to the tissues independent of hemoglobin. For a variety of organ systems, HBO is known to promote new vessel growth into areas with reduced oxygen tension due to poor vascularity, and therewith promotes wound healing and recovery of radiation-injured tissue. Furthermore, tumors may be sensitized to irradiation by raising intratumoral oxygen tensions. Methods: A network of hyperbaric facilities exists in Europe, and a number of clinical studies are ongoing. The intergovernmental framework COST B14 action 'Hyperbaric Oxygen Therapy' started in 1999. The main goal of the Working Group Oncology is preparation and actual implementation of prospective study protocols in the field of HBO and radiation oncology in Europe. Results: In this paper a short overview on HBO is given and the following randomized clinical studies are presented: (a) reirradiation of recurrent squamous cell carcinoma of the head and neck after HBO sensitization; (b) role of HBO in enhancing radiosensitivity on glioblastoma multiforme; (c) osseointegration in irradiated patients; adjunctive HBO to prevent implant failures; (d) the role of HBO in the treatment of late irradiation sequelae in the pelvic region. The two radiosensitization protocols (a, b) allow a time interval between HBO and subsequent irradiation of 10-20 min. Conclusion: Recruitment of centers and patients is being strongly encouraged, detailed information is given on www.oxynet.org. (orig.)

Variability in hyperbaric oxygen treatment for acute carbon monoxide poisoning.

Science.gov (United States)

Byrne, Brendan T; Lu, Jenny J; Valento, Matthew; Bryant, Sean M

2012-01-01

In patients with acute carbon monoxide (CO) poisoning, we have noted wide clinical variability in both criteria for hyperbaric oxygen (HBO2) treatment as well as HBO2 treatment regimens. Our aim was to survey Midwest hyperbaric centers for insight into specific criteria and protocols for treating acute CO toxicity with HBO2. Hyperbaric centers were identified from the published list of the Undersea and Hyperbaric Medical Society. Ninety-three centers from nine Midwestern states were contacted via telephone. A standard script was used to minimize surveyor bias. Thirty centers that treat CO poisonings were identified. One did not participate in the study. Nineteen reported a specific level of carboxyhemoglobin (COHb) that served as an independent indication for initiation of HBO2 treatment. Four centers used the COHb level as the exclusive indication for HBO2 treatment. Ten centers relied solely on reported symptoms, while the remaining centers used a combination of symptoms plus COHb levels. There were 19 separate treatment protocols. No uniform practice for either the initiation or implementation of HBO2 therapy for CO poisoning exists among U.S. Midwest hyperbaric centers responding to a survey. We see opportunity for specific targeted educational programs as well as further study.

Perceptions of hyperbaric oxygen therapy among podiatrists practicing in high-risk foot clinics.

Science.gov (United States)

Henshaw, Frances R; Brennan, Lauren; MacMillan, Freya

2018-01-03

Foot ulceration is a devastating and costly consequence of diabetes. Hyperbaric oxygen therapy is recognised as an adjunctive therapy to treat diabetes-related foot ulceration, yet uptake is low. Semi-structured interviews were conducted with 16 podiatrists who manage patients with foot ulcers related to diabetes to explore their perceptions of, and the barriers/facilitators to, referral for hyperbaric oxygen. Podiatrists cited logistical issues such as location of facilities as well as poor communication pathways, lack of delegation and lack of follow up when patients presented for hyperbaric treatment. In general, podiatrists had an understanding of the premise of hyperbaric oxygen therapy and evidence to support its use but could only provide very limited citations of key papers and guidelines to support their position. Podiatrists stated that they felt a patient was lost from their care when referred for hyperbaric oxygen and that aftercare might not be adequate. Improved referral and delegation pathways for patients presenting for hyperbaric oxygen, as well as the provision of easily accessible evidence to support this therapy, could help to increase podiatrists' confidence in deciding whether or not to recommend their patients for hyperbaric oxygen therapy. © 2018 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Is there a difference between active opening of the Eustachian tube in a hypobaric surrounding compared to a hyperbaric surrounding?

Science.gov (United States)

Mikolajczak, Stefanie; Meyer, Moritz Friedo; Felsch, Moritz; Jumah, Masen Dirk; Hüttenbrink, Karl-Bernd; Grosheva, Maria; Luers, Jan-Christoffer; Beutner, Dirk

2015-01-01

The Eustachian tube (ET) is the key to pressure equalization between the middle ear and ambient pressure. To date, little is known about differences of the opening mechanisms under hyper- or hypobaric conditions. Aim of this study was to compare standard ET opening parameters during standardized hypo- and hyperbaric exposures. Thirty healthy participants were exposed to a standardized profile of decompression and compression (SPDC) in a hypo-/hyperbaric pressure chamber. Impedance, expressed as tympanic membrane compliance, was recorded at intervals during the excursions from 1 atmosphere absolute (atm abs) to 0.8 and 1.2 atm abs respectively. Parameters for tubal opening were obtained during SPDC: ET opening pressure (ETOP), ET opening duration (ETOD) and ET opening frequency (ETOF), hypobaric (Phase 1) and hyperbaric (Phase 2) data were compared. Mean value for Valsalva maneuver ETOP was 40.10 ± 19.02 mbar in Phase 2 vs. 42.82 ± 21.75 mbar in Phase 1. For ETOD it was 2.80 ± 2.09 seconds in Phase 2 vs. 2.51 ± 1.90 seconds in Phase 1. For swallowing, mean value for ETOP was 33.47 ± 14.50 mbar in Phase 2 vs. 28.44 ± 14.04 in Phase 1. ETOD was 0.82 ± 0.60 seconds in Phase 2 vs. 0.76 ± 0.55 seconds in Phase 1. There was no statistical significance for ETOP, ETOD and ETOF between the two phases. No statistical significant difference was evident for active pressure equalization (Valsalva and swallowing) between a hyperbaric setting (dive) and a hypobaric setting (flight) in healthy subjects.

Effect of hyperbaric environment on fine motor skills

OpenAIRE

Les, Martin

2017-01-01

Title: Effect of hyperbaric environment on fine motor skills Objectives: The aim of study is to assess the changes fine motor skills due to hyperbaric environment in preparation for selected tests of fine motor skills. Methods: The first method was used empirically - research. Then the method chosen of compilation of the information obtained. The basic method to work was the experimental measurement method specially constructed tests on fine motor skills. All measured values were statisticall...

A comparison of low dose hyperbaric levobupivacaine and hypobaric levobupivacaine in unilateral spinal anaesthesia.

Science.gov (United States)

Kaya, M; Oztürk, I; Tuncel, G; Senel, G Ozalp; Eskiçirak, H; Kadioğullari, N

2010-11-01

The aim of this study was to compare the clinical effects and characteristics of hyperbaric and hypobaric levobupivacaine for unilateral spinal anaesthesia. Sixty patients were randomly allocated into two groups to receive either 7.5 mg (1.5 ml) hyperbaric levobupivacaine 0.5% or 7.5 mg (4 ml) hypobaric levobupivacaine 0.1875% for elective arthroscopic surgery of the knee under spinal anaesthesia. The level and duration of sensory block, intensity and duration of motor block were recorded. Unilateral sensory block was observed in 27 patients (90%) in the hyperbaric group and 24 patients (80%) in the hypobaric group in the lateral position. After 15 minutes, patients were turned to supine to redistribute the spinal block toward the non-operative side, but spinal anaesthesia was still unilateral in 18 patients (60%) in the hyperbaric group and 10 patients (33%) in the hypobaric group (P = 0.038). Time to readiness for home discharge and complete recovery of sensory block were similar in both groups. In the hyperbaric group, the motor block scores were higher on the operative side during first 10 minutes than they were in the hypobaric group (P hyperbaric group (P = 0.01). Hyperbaric and hypobaric levobupivacaine both provided satisfactory unilateral spinal anaesthesia with good haemodynamic stability for arthroscopic surgery, but with more frequent unilateral spinal anaesthesia in the hyperbaric group.

[From 1878 to 2006 - working in hyperbaric conditions during tunnelling].

Science.gov (United States)

Le Péchon, Jean-Claude

2006-01-01

To review the impact of Paul Bert's researches on hyperbaric work in tunnelling, the status of the industry in 1878 is described. Mostly based on the application of Triger's machine it was used to mine coal below the water table or to dig foundations for bridges in rivers or close to rivers. The results and conclusions obtained by Paul Bert which are applicable in that particular field are listed. The major steps of research or remarkable achievements in construction between 1878 and 2006 are presented as well as the evolution of decompression tables. Improvement in safety and conditions of caisson workers has been continuous until the technical revolution resulting from the introduction and the development of tunnelling boring machines (TBM) in the late 80's. TBM technology has resulted in major changes in tunnel construction. Hyperbaric interventions have also changed completely since human operators no longer work in pressurized conditions. Only occasional inspections and repairs are carried out under pressure. Present performance in hyperbaric conditions are reported, and high pressures reached in the 2000's using saturation technology are described. The future of hyperbaric works is also discussed whether for very high pressure, or complete replacement of caisson workers in TBMs. These descriptions show that Paul Bert provides us with very clear directions to improve safety in hyperbaric conditions and that none of his recommendations were mistaken, most being still relevant.

Comparison of hypobaric, hyperbaric, and isobaric solutions of bupivacaine during continuous spinal anesthesia.

Science.gov (United States)

Van Gessel, E F; Forster, A; Schweizer, A; Gamulin, Z

1991-06-01

This study was designed to compare the anesthetic properties of hypobaric bupivacaine with those of isobaric and hyperbaric solutions when administered in the supine position in an elderly population undergoing hip surgery using continuous spinal anesthesia. Plain bupivacaine (0.5%) was mixed with equal volumes of 10% dextrose (hyperbaric), 0.9% NaCl (isobaric), or distilled water (hypobaric) to obtain 0.25% solutions. In a double-blind fashion, all patients received 3 mL (7.5 mg) of their particular solution injected through the spinal catheter in the horizontal supine position. The sensory level obtained in the hyperbaric group (median, T4; range, T3-L3) was significantly higher than in both the isobaric (median, T11; range, T6-L1) and hypobaric (median, L1; range, T4-L3) groups. A motor blockade of grade 2 or 3 was obtained in 14 of 15 and 12 of 15 patients in, respectively, the hyperbaric and isobaric groups, but only in 8 of 15 patients in the hypobaric group. After the initial injection of 3 mL (7.5 mg), a sensory level of T10 and a motor blockade of grade 2 or 3 was obtained in 14 of 15, 5 of 15, and 3 of 15 patients in the hyperbaric, isobaric, and hypobaric groups, respectively. All remaining patients received 1 or 2 additional milliliters (2.5-5 mg) and achieved these required anesthetic conditions, except for one patient in the hyperbaric group and eight patients in the hypobaric group in whom anesthesia was achieved with hyperbaric tetracaine. The decrease in mean arterial pressure was significantly more severe in the hyperbaric (30%) than in either the isobaric (18%) or hypobaric (14%) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Benefits of hyperbaric oxygen pretreatment for decompression sickness in Bama pigs.

Science.gov (United States)

Qing, Long; Yi, Hong-Jie; Wang, Ye-Wei; Zhou, Quan; Ariyadewa, Dinesh K; Xu, Wei-Gang

2018-03-07

Decompression sickness (DCS) occurs when ambient pressure is severely reduced during diving and aviation. Hyperbaric oxygen (HBO) pretreatment has been shown to exert beneficial effects on DCS in rats via heat-shock proteins (HSPs). We hypothesized that HBO pretreatment will also reduce DCS via HSPs in swine models. In the first part of our investigation, six swine were subjected to a session of HBO treatment. HSP32, 60, 70 and 90 were detected, before and at 6, 12, 18, 24 and 30 h following exposure in lymphocytes. In the second part of our investigation, another 10 swine were randomly assigned into two groups (five per group). All swine were subjected to two simulated air dives in a hyperbaric chamber with an interval of 7 days. Eighteen hours before each dive, the swine were pretreated with HBO or air: the first group received air pretreatment prior to the first dive and HBO pretreatment prior to the second; the second group were pretreated with HBO first and then air. Bubble loads, skin lesions, inflammation and endothelial markers were detected after each dive. In lymphocytes, all HSPs increased significantly ( P <0.05), with the greatest expression appearing at 18 h for HSP32 and 70. HBO pretreatment significantly reduced all the determined changes compared with air pretreatment. The results demonstrate that a single exposure to HBO 18 h prior to diving effectively protects against DCS in the swine model, possibly via induction of HSPs. © 2018. Published by The Company of Biologists Ltd.

Osmotic phenomena in application for hyperbaric oxygen treatment.

Science.gov (United States)

Babchin, A; Levich, E; Melamed M D, Y; Sivashinsky, G

2011-03-01

Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood

An Innovative Hyperbaric Hypothermic Machine Perfusion Protects the Liver from Experimental Preservation Injury

Directory of Open Access Journals (Sweden)

Ferdinando A. Giannone

2012-01-01

Full Text Available Purpose. Hypothermic machine perfusion systems seem more effective than the current static storage to prevent cold ischemic liver injury. Thus, we test an innovative hyperbaric hypothermic machine perfusion (HHMP, which combines hyperbaric oxygenation of the preservation solution and continuous perfusion of the graft. Methods. Rat livers were preserved with Celsior solution according to 4 different modalities: normobaric static preservation; hyperbaric static preservation at 2 atmosphere absolute (ATA; normobaric dynamic preservation, with continuous perfusion; hyperbaric dynamic preservation, with continuous perfusion at 2 ATA. After 24 h cold preservation, we assessed different parameters. Results. Compared to baseline, livers preserved with the current static storage showed severe ultrastructural damage, glycogen depletion and an increased oxidative stress. Normobaric perfused livers showed improved hepatocyte ultrastructure and ameliorated glycogen stores, but they still suffered a significant oxidative damage. The addition of hyperbaric oxygen produces an extra benefit by improving oxidative injury and by inducing endothelial NO synthase (eNOS gene expression. Conclusions. Preservation by means of the present innovative HHMP reduced the liver injury occurring after the current static cold storage by lowering glycogen depletion and oxidative damage. Interestingly, only the use of hyperbaric oxygen was associated to a blunted oxidative stress and an increased eNOS gene expression.

Does hyperbaric oxygen therapy reduce the effects of ischemia on colonic anastomosis in laparoscopic colon resection?

Science.gov (United States)

Emir, Seyfi; Gurdal, Sibel Ozkan; Sozen, Selim; Bali, Ilhan; Yesildag, Ebru; Celik, Atilla; Guzel, Savas; Sahin, Onder; Ay, Hakan; Topcu, Birol

2016-01-01

An increase in intra-abdominal pressure causes a decrease in the splanchnic blood flow and the intramucosal pH of the bowel, as well as increasing the risk of ischemia in the colon. The aim of the present study is to evaluate the effect of hyperbaric oxygen therapy (HBOT) on the ischemia caused by laparoscopy in colonic anastomosis in an experimental model of laparoscopic colonic surgery. We divided 30 male Wistar albino rats into three groups: Group A was the control (open colon anastomosis); Group B received LCA (laparoscopic colon anastomosis); while Group C received both LCA and HBOT. Each group contained ten animals. We placed Group C (LCA and HBOT) in an experimental hyperbaric chamber into which we administered pure oxygen at 2.1 atmospheres absolute 100% oxygen for 60 min for ten consecutive days. The anastomotic bursting pressure value was found to be higher in the open surgery group (226 ± 8.8) (Group A). The result for Group C (213 ± 27), which received HBOT, was better than that for Group B (197 ± 27). However, there was no statistically significant difference between Group B and Group C. Group A showed better healing than the other groups, while significant differences in the fibroblast proliferation scores were found between Groups A and B. In terms of tissue hydroxyproline levels, a significant difference was found between Groups A and B and between Groups A and C, but not between Groups B and C. HBOT increases the oxygen level in the injured tissue. Although HBOT might offer several advantages, it had only a limited effect on the healing of colonic anastomosis in rats with increased intra-abdominal pressure in our study. Anastomosis, Colon, Hyperbaric Oxygen Treatment, Oxidative Stress.

Aerospace Physiologist, AFSCs 43AX, M11XXY, and M122XY (Formerly AFSCs 916X, 149XA, and 229XY)

Science.gov (United States)

1993-12-01

need arises, such as during hyperbaric and hypobaric chamber operations and specialized aerospace physiology classroom training requirements. xi 7... Hyperbaric And Hypobaric Chambers Little Rock AFB AK High Altitude Airdrop Mission Support (HAAMS) Holloman AFB NM Centrifuge Training Travis AFB CA... hypobaric , or hyperbaric chambers, etc.). Representative tasks which show the differentiation in time spent on duties among the DAFSC officers are

Operational Medical Issues in Hypo-and Hyperbaric Conditions (les Questions medicales a caractere oprationel liees aux conditions hypobares ou hyperbares)

National Research Council Canada - National Science Library

2001-01-01

.... Themes addressed were decompression illness, breathing gas composition, hypoxia, hyperbaric oxygen treatment of combat injuries, selection, training and adaptation of personnel for special operations...

Effects of hyperbaric, normobaric and hypobaric oxygen supplementation on retinal vessels in newborn rats: a preliminary study.

Science.gov (United States)

Ricci, B

1987-03-01

An experimental study was conducted on eight litters of newborn rats to evaluate the effects of supplemental oxygen administration on the retinal vasculature. The animals and their mothers were kept inside a pressure chamber and treated for the first 5 days of life. On the sixth day, they were removed and kept for five more days under room air and normobaric conditions. Three litters received continuous flow oxygen at 80% at a compression pressure of +81 kPa, one litter oxygen at 80% at a pressure of -39.5 kPa atms and three other litters received oxygen at 80% under normobaric conditions. The eighth litter was treated with room air oxygen at a compression pressure of +81 kPa. A severe retinopathy with marked retinal neovascularization was seen only in the newborn animals of the litters that received oxygen supplementation under normobaric or hypobaric conditions. Retinal vessels showed no pathological changes in the litters treated with hyperbaric normoxia or hyperoxia. It is possible to hypothesize that the prolonged period of oxygen supplementation failed to produce harmful effects on the retinal vasculature because the moderate hyperbarism caused mild retinal and choroidal vasoconstriction thus preventing excessive oxygen transport to the inner retina from the choroid during hyperoxia without inducing structural damage to the retinal tissue.

Adverse reactions of hyperbaric oxygen therapy - case description of a generalised seizure

Directory of Open Access Journals (Sweden)

Grobelska Kinga

2016-03-01

Full Text Available Hyperbaric oxygen therapy (HBOT is a safe treatment, provided fulfilling certain rules of patient qualifications to treatment, as well as supervision over the course of therapy by qualified medical staff. Side effects reported in the literature are rare, and are usually mild and transient. Professional medical staff allows minimising the adverse events occurrence. The scale of complications is unknown, especially in Polish hyperbaric center. Careful analysis could be used to develop prevention procedures for patients of hyperbaric oxygen therapy. Hyperbaric Oxygen Centre and Wound Treatment in Bydgoszcz during 28 months performed hyperbaric oxygen therapy (HBOT in case of 423 patients. During this period, adverse events occurred occasionally. 17 cases have been reported. Authors described study case 77 year-old patient who was admitted due to non-healing wound-left lower abdomen (state after radiotherapy. During the fourth session, on decompression phase patient have had a generalized seizure (tonic-clonic. The decompression was stopped, the oxygen supply was disconnected but only after the drug administration seizures terminated. The most likely causative agent of the adverse reactions of the patient treated with HBOT was the oxygen toxic effect on the brain tissue. However, analyzing the circumstances of the seizure termination: phase of decompression at the pressure 2ATA and lack of oxygen disconnection response, it cannot be excluded other causes of this complication.

Antioxidants may Attenuate Plasma Erythropoietin Decline after Hyperbaric Oxygen Diving.

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Mutzbauer, T S; Schneider, M; Neubauer, B; Weiss, M; Tetzlaff, K

2015-11-01

According to previous studies, plasma erythropoietin (EPO) may decrease after hyperbaric oxygen exposure due to oxidative stress. It is hypothesized that the decrease of EPO can be attenuated by oxygen free radical scavengers.The aim of the present study was to evaluate whether EPO plasma levels can be influenced by oral application of vitamin C and E before repeated hyperbaric oxygen exposure during diving. 16 healthy male police task force divers performed 3 morning dives on oxygen within a regular diving schedule on 3 consecutive days. They were randomized into either the placebo group or the vitamin group, receiving 1 g ascorbic acid and 600 IU D-α-tocopherol orally 60 min before the dive. Blood samples for EPO measurement were taken on days 1, 2, and 3 at T1, T3 and T5 60 min before and at T2, T4 and T6 60 min after each dive, respectively. A moderate decrease of EPO was observed beginning at T3 until T6 in the placebo group. The EPO concentrations in the vitamin group did not show relevant variations compared to baseline. Radical scavenging vitamins C and D may counteract hyperbaric oxygen related mechanisms reducing EPO production in hyperbaric oxygen exposure during diving. © Georg Thieme Verlag KG Stuttgart · New York.

Hyperbaric oxygen reduces edema and necrosis of skeletal muscle in compartment syndromes associated with hemorrhagic hypotension

International Nuclear Information System (INIS)

Skyhar, M.J.; Hargens, A.R.; Strauss, M.B.; Gershuni, D.H.; Hart, G.B.; Akeson, W.H.

1986-01-01

This study examined the effect of exposures to hyperbaric oxygen on the development of the edema and necrosis of muscle that are associated with compartment syndromes that are complicated by hemorrhagic hypotension. A compartment syndrome (twenty millimeters of mercury for six hours) was induced by infusion of autologous plasma in the anterolateral compartment of the left hind limb of seven anesthetized dogs while the mean arterial blood pressure was maintained at sixty-five millimeters of mercury after 30 per cent loss of blood volume. These dogs were treated with hyperbaric oxygen (two atmospheres of pure oxygen) and were compared with six dogs that had an identical compartment syndrome and hypotensive condition but were not exposed to hyperbaric oxygen. Forty-eight hours later, edema was quantified by measuring the weights of the muscles (the pressurized muscle compared with the contralateral muscle), and necrosis of muscle was evaluated by measuring the uptake of technetium-99m stannous pyrophosphate. The ratio for edema was significantly (p = 0.01) greater in dogs that had not been exposed to hyperbaric oxygen (1.15 +/- 0.01) than in the dogs that had been treated with hyperbaric oxygen (1.01 +/- 0.03), and the ratio for necrosis of muscle was also significantly (p = 0.04) greater in dogs that had not had hyperbaric oxygen (1.96 +/- 0.41) than in those that had been treated with hyperbaric oxygen (1.05 +/- 0.11). Comparisons were also made with the muscles of four normal control dogs and separately with the muscles of six normotensive dogs that had an identical compartment syndrome and normal blood pressure and were not treated with hyperbaric oxygen

Hyperbaric oxygen in skeletal muscle of rats submitted to total acute left hindlimb ischemia: A research report.

Science.gov (United States)

da Silva, Luis Gustavo Campos; Dalio, Marcelo Bellini; Joviliano, Edwaldo Edner; Feres, Omar; Piccinato, Carlos Eli

2015-01-01

Determine the effect of hyperbaric oxygen treatment in skeletal muscle of rats submitted to total acute left hindlimb ischemia. An experimental study was designed using 48 Wistar rats divided into four groups (n = 12): Control; Ischemia (I)--total hindlimb ischemia for 270 minutes; Hyperbaric oxygen treatment during ischemia (HBO2)--total hindlimb ischemia for 270 minutes and hyperbaric oxygen during the first 90 minutes; Pre-treatment with hyperbaric oxygen (PHBO2)--90 minutes of hyperbaric oxygen treatment before total hindlimb ischemia for 270 minutes. Skeletal muscle injury was evaluated by measuring levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), total creatine phosphokinase (CPK); muscular malondialdehyde (MDA), muscular glycogen, and serum ischemia-modified albumin (IMA). AST was significantly higher in I, HBO2 and PHBO2 compared with control (P = .001). There was no difference in LDH. CPK was significantly higher in I, HBO2 and PHBO2, compared with control (p = .014). MDA was significantly higher in PHBO2, compared with other groups (p = .042). Glycogen was significantly decreased in I, HBO2 and PHBO2, compared with control (p < .001). Hyperbaric oxygen treatment in acute total hindlimb ischemia exerted no protective effect on muscle injury, regardless of time of application. When applied prior to installation of total ischemia, hyperbaric oxygen treatment aggravated muscle injury.

Hyperbaric Oxygen Therapy for Radiation-Induced Cystitis and Proctitis

International Nuclear Information System (INIS)

Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W.; Komarnicky, Lydia T.

2012-01-01

Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for radiation-induced HC and proctitis. The median age at treatment was 66 years (range, 15–84 years). The range of external-beam radiation delivered was 50.0–75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90–120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues—Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7–70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for radiation-induced HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.

l'otite externe nécrosante place de l'oxygénothérapie hyperbare

African Journals Online (AJOL)

HÔPITAL UNIVERSITAIRE FARHAT HACHED SOUSSE. * CENTRE ... Keywords : Necrotizing otitis externa; hyperbaric oxygen therapy; treatment. CAS CLINIQUES .... rapie hyperbare, mais la disponibilité d'un seul centre en. Tunisie. Auteurs.

Effect of hyperbaric oxygen therapy combined with autologous platelet concentrate applied in rabbit fibula fraction healing

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Paulo Cesar Fagundes Neves

2013-09-01

Full Text Available OBJECTIVES: The purpose is to study the effects of hyperbaric oxygen therapy and autologous platelet concentrates in healing the fibula bone of rabbits after induced fractures. METHODS: A total of 128 male New Zealand albino rabbits, between 6-8 months old, were subjected to a total osteotomy of the proximal portion of the right fibula. After surgery, the animals were divided into four groups (n = 32 each: control group, in which animals were subjected to osteotomy; autologous platelet concentrate group, in which animals were subjected to osteotomy and autologous platelet concentrate applied at the fracture site; hyperbaric oxygen group, in which animals were subjected to osteotomy and 9 consecutive daily hyperbaric oxygen therapy sessions; and autologous platelet concentrate and hyperbaric oxygen group, in which animals were subjected to osteotomy, autologous platelet concentrate applied at the fracture site, and 9 consecutive daily hyperbaric oxygen therapy sessions. Each group was divided into 4 subgroups according to a pre-determined euthanasia time points: 2, 4, 6, and 8 weeks postoperative. After euthanasia at a specific time point, the fibula containing the osseous callus was prepared histologically and stained with hematoxylin and eosin or picrosirius red. RESULTS: Autologous platelet concentrates and hyperbaric oxygen therapy, applied together or separately, increased the rate of bone healing compared with the control group. CONCLUSION: Hyperbaric oxygen therapy and autologous platelet concentrate combined increased the rate of bone healing in this experimental model.

Occupational Survey Report. AFSC 4M0X1 Aerospace Physiology

Science.gov (United States)

2002-05-01

Chamber NCOIC Job Hyperbaric Chamber Specialist Job • Perform Type 2, 4 and 1 chamber flights • Perform inside observer duties during hypobaric ...78% Hyperbaric Chamber Specialist Independent Job 4% Not Grouped 2% U2 Aerospace Physiology Cluster 10% Job Structure Sample size: 168 Aerospace...Altitude Chamber Cluster (N=130) Hypobaric Chamber Instructor/Monitor Job HAAMS Job Altitude Chamber Apprentice Job 78% UPT Parasail Job Altitude

Preliminary Clinical Study On Ms Treatment With Hyperbaric Oxygenation

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Ulewicz Kazimierz

2015-06-01

Full Text Available The authors conducted the preliminary clinical investigation on 16 multiple sclerosis (Sclerosis multiplex patients of median disease duration 9.33 years and symptoms evaluated on Kurtzke’s scale. The patients underwent between 25 and 30 hyperbaric oxygen exposures at a pressure of 2 ata in intervals spread over a few days. The patients were qualified and classified to the treatment symptomatologically according to Fisher but the obtained results were evaluated according to the standardised Disability Status Scale by Kurtzke. During the investigations the authors carried out additional quantitative immunoglobulin and complement activity determination, lymphocyte T and B determinations as well as the usually applied clinical and laboratory investigations. Evident clinical improvement was observed in 14 patients, but in the case of one patient a deterioration was observed after 15 hyperbaric expositions (resulting in the hyperbaric oxygen treatment being stopped, whilst in another case no curative effect could be observed. By utilising the 50% haemolysis method, within the examined immunological parameters the authors observed an increase of complement fractions and its activity, white lymphocytes T and B examined qualitatively did not maintain the characteristic shift. The authors are still discussing the obtained results.

Hyperbaric oxygen for post-concussive symptoms in United States military service members: a randomized clinical trial.

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Weaver, Lindell K; Wilson, Steffanie H; Lindblad, Anne S; Churchill, Susan; Deru, Kayla; Price, Robert C; Williams, Chris S; Orrison, William W; Walker, James M; Meehan, Anna; Mirow, Susan

2018-01-01

In prior military randomized trials, participants with persistent symptoms after mild traumatic brain injury (TBI) reported improvement regardless of receiving hyperbaric oxygen (HBO₂) or sham intervention. This study's objectives were to identify outcomes for future efficacy trials and describe changes by intervention. This Phase II, randomized, double-blind, sham-controlled trial enrolled military personnel with mild TBI and persistent post-concussive symptoms. Participants were randomized to receive 40 HBO₂ (1.5 atmospheres absolute (ATA), ⟩99% oxygen, 60 minutes) or sham chamber sessions (1.2 ATA, room air, 60 minutes) over 12 weeks. Participants and evaluators were blinded to allocation. Outcomes assessed at baseline, 13 weeks and six months included symptoms, quality of life, neuropsychological, neurological, electroencephalography, sleep, auditory, vestibular, autonomic, visual, neuroimaging, and laboratory testing. Participants completed 12-month questionnaires. Intention-to-treat results are reported. From 9/11/2012 to 5/19/2014, 71 randomized participants received HBO₂ (n=36) or sham (n=35). At baseline, 35 participants (49%) met post-traumatic stress disorder (PTSD) criteria. By the Neurobehavioral Symptom Inventory, the HBO₂ group had improved 13-week scores (mean change -3.6 points, P=0.03) compared to sham (+3.9 points). In participants with PTSD, change with HBO₂ was more pronounced (-8.6 vs. +4.8 points with sham, P=0.02). PTSD symptoms also improved in the HBO₂ group, and more so in the subgroup with PTSD. Improvements regressed at six and 12 months. Hyperbaric oxygen improved some cognitive processing speed and sleep measures. Participants with PTSD receiving HBO₂ had improved functional balance and reduced vestibular complaints at 13 weeks. By 13 weeks, HBO₂ improved post-concussive and PTSD symptoms, cognitive processing speed, sleep quality, and balance function, most dramatically in those with PTSD. Changes did not persist

A low-dose bupivacaine: a comparison of hyperbaric and hypobaric solutions for unilateral spinal anesthesia.

Science.gov (United States)

Kaya, Menşure; Oğuz, Selma; Aslan, Kemal; Kadioğullari, Nihal

2004-01-01

The injection of small doses of local anesthetic solutions through pencil-point directional needles and maintaining the lateral decubitus position for 15 to 30 minutes after the injection have been suggested to facilitate the unilateral distribution of spinal anesthesia. We evaluated the effects of hypobaric and hyperbaric bupivacaine in attempting to achieve unilateral spinal anesthesia for patients undergoing lower limb orthopedic surgery. Fifty patients were randomly allocated into 2 groups to receive either 1.5 mL hyperbaric bupivacaine 0.5% (7.5 mg; n = 25) or 4.2 mL hypobaric bupivacaine 0.18% (7.5 mg; n = 25). Drugs were administered at the L3-4 interspace with the patient in the lateral position. Patients remained in this position for 15 minutes before turning supine for the operation. Spinal block was assessed by pinprick and modified Bromage scale on both sides. Unilateral spinal block was observed in 20 patients in the hyperbaric group (80%) and in 19 patients in the hypobaric group (76%) while in the lateral position. However, 15 minutes after patients were turned supine, unilateral spinal anesthesia decreased to 68% of cases in the hyperbaric group and 24% of cases in the hypobaric group (P hyperbaric and hypobaric bupivacaine provided a rapid motor and sensory recovery and good hemodynamic stability, but more unilateral spinal block was achieved in patients in the hyperbaric group when compared with patients in the hypobaric group.

Hyperbaric oxygen therapy for x-ray ulcer

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Mishina, Hitoshi; Haryu, Tsuneo; Shioshima, Shoji; Imaizumi, Akio; Sato, Yasushi [Tohoku Rosai Hospital, Sendai, Miyagi (Japan)

1977-05-01

Hyperbaric oxygen therapy was performed in 6 cases (female) of x-ray ulcer following radiotherapy for breast cancer, esophageal cancer, uterine cancer, and rectal cancer. The exposed dose ranged from 4500 to 7500 R, and x-ray ulcer occurred after one to twelve years of the irradiation. The mixed intravenous instillation composed of 1200 mg of Glutathione, 1 g of VC, and 6000 unit of Uronase was performed before the performance of the hyperbaric oxygen therapy. This therapy was carried out once a day for 20 days (one period), and was suspended for one to two weeks between periods. It was carried out for about four periods. Furthermore, antibiotics and local ointment were used. Disappearance of ulcer was recognized in 5 of 6 cases, and the recurrence has not been found out for 4 years. One case, the rest, was given Cytorevie, and did not receive this therapy from his will.

Comparative study of the hyperbaric hyperoxygenation in ischemic colonic loops in rats Estudo comparativo da hiperoxigenação hiperbárica em alças cólicas isquêmicas em ratos

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Antonio Angelo Rocha

2007-04-01

Full Text Available PURPOSE: To analyze and to evaluate the effect of the hyperbaric hyperoxygenation in the mechanical resistance of ischemic colon of rats. METHODS: Eighty rats, distributed in four groups of 20 animals in each one, were used. In group 1 (G1, the control group, ischemia was not caused. Group 2 was submitted to the lesser degree of ischemia. Group 3 was submitted to the intermediate degree of ischemia. In group 4, a bigger degree of intestinal ischemia was provoked. Each group was divided in two sub-groups of ten animals each: with hyperbaric chamber (CC and without hyperbaric chamber (SC. The animals of the four CC subgroups were placed in an experimental hyperbaric chamber in order to inhale oxygen at 100%, at two Absolute Atmospheres, for 120 minutes, for a four-day consecutive period. The animals of the four SC subgroups were kept in environment air during the five days of the experiment. All animals have been submitted to the mechanical study of the intestinal loop by the pressure test of the rupture by liquid distension. The euthanasia occurred in the fifth post-operative day. RESULTS: Considering the ischemia factor, the four groups were different among them (p=0.0001. There was no statistical difference between subgroups CC and SC (p=0.3461. CONCLUSION: The hyperbaric oxygen-therapy did not present improvement on the induced ischemia in rats upright colic loop.OBJETIVO: Analisar e avaliar os efeitos da hiperoxigenação hiperbárica na resistência mecânica do cólon isquêmico de ratos. MÉTODOS: Foram utilizados 80 ratos distribuídos em quatro grupos de 20 animais. No grupo 1, grupo controle, não se provocou isquemia. O grupo 2 foi submetido ao grau menor de isquemia. O grupo 3 foi submetido ao grau intermediário de isquemia. No grupo 4, provocou-se grau maior de isquemia intestinal. Cada grupo foi dividido em dois subgrupos de dez animais cada: com câmara hiperbárica (CC e sem câmara hiperbárica (SC. Os animais dos quatro

Effects of hyperbaric oxygen at 1.25 atmospheres absolute with normal air on macrophage number and infiltration during rat skeletal muscle regeneration.

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Naoto Fujita

Full Text Available Use of mild hyperbaric oxygen less than 2 atmospheres absolute (2026.54 hPa with normal air is emerging as a common complementary treatment for severe muscle injury. Although hyperbaric oxygen at over 2 atmospheres absolute with 100% O2 promotes healing of skeletal muscle injury, it is not clear whether mild hyperbaric oxygen is equally effective. The purpose of the present study was to investigate the impact of hyperbaric oxygen at 1.25 atmospheres absolute (1266.59 hPa with normal air on muscle regeneration. The tibialis anterior muscle of male Wistar rats was injured by injection of bupivacaine hydrochloride, and rats were randomly assigned to a hyperbaric oxygen experimental group or to a non-hyperbaric oxygen control group. Immediately after the injection, rats were exposed to hyperbaric oxygen, and the treatment was continued for 28 days. The cross-sectional area of centrally nucleated muscle fibers was significantly larger in rats exposed to hyperbaric oxygen than in controls 5 and 7 days after injury. The number of CD68- or CD68- and CD206-positive cells was significantly higher in rats exposed to hyperbaric oxygen than in controls 24 h after injury. Additionally, tumor necrosis factor-α and interleukin-10 mRNA expression levels were significantly higher in rats exposed to hyperbaric oxygen than in controls 24 h after injury. The number of Pax7- and MyoD- or MyoD- and myogenin-positive nuclei per mm2 and the expression levels of these proteins were significantly higher in rats exposed to hyperbaric oxygen than in controls 5 days after injury. These results suggest that mild hyperbaric oxygen promotes skeletal muscle regeneration in the early phase after injury, possibly due to reduced hypoxic conditions leading to accelerated macrophage infiltration and phenotype transition. In conclusion, mild hyperbaric oxygen less than 2 atmospheres absolute with normal air is an appropriate support therapy for severe muscle injuries.

Hyperbaric oxygen therapy for x-ray ulcer

International Nuclear Information System (INIS)

Mishina, Hitoshi; Haryu, Tsuneo; Shioshima, Shoji; Imaizumi, Akio; Sato, Yasushi

1977-01-01

Hyperbaric oxygen therapy was performed in 6 cases (female) of x-ray ulcer following radiotherapy for breast cancer, esophageal cancer, uterine cancer, and rectal cancer. The exposed dose ranged from 4500 to 7500 R, and x-ray ulcer occurred after one to twelve years of the irradiation. The mixed intravenous instillation composed of 1200 mg of Glutathione, 1 g of VC, and 6000 unit of Uronase was performed before the performance of the hyperbaric oxygen therapy. This therapy was carried out once a day for 20 days (one period), and was suspended for one to two weeks between periods. It was carried out for about four periods. Furthermore, antibiotics and local ointment were used. Disappearance of ulcer was recognized in 5 of 6 cases, and the recurrence has not been found out for 4 years. One case, the rest, was given Cytorevie, and did not receive this therapy from his will. (Kanao, N.)

[Clinical research of hyperbaric, isobaric, and hypobaric solutions of bupivacaine in continuous spinal anesthesia].

Science.gov (United States)

Yang, Hong-wei; Bai, Nian-yue; Guo, Qu-lian

2005-02-01

To compare the anesthesia properities of hyperbaric bupivacaine with those of isobaric and hypobaric solutions when administered in the supine position undergoing hip surgery or lower limb surgery using continuous spinal anesthesia. Sixty patients( ASA I approximately III ) scheduled for hip or lower limb surgery were randomly divided into 3 groups with 20 patients in each group: Group A: 0. 375% hyperbaric bupivacaine solutions; Group B :0.375% isobaric bupivacaine solutions; and Group C: 0. 375% hypobaric bupivacaine solutions. The following variables were measured every 2 minutes during the first 30 minutes after the intrathecal injection : the onset time of sensation block, the highest plane of analgesia, the time to reach complete motor blockade, and the plane of analgesia and the extent of lower extremities' movement (modified bromage score, BMS) at different time after the administration. Meanwhile the changes of hemodynamics were recorded. There was no statistical difference among the basic conditions ( P > 0.05). The onset time of sensation block, and the time to reach complete motor blockade, and the time receiving the highest sharp pain sensory block in Group A were significantly shorter than those in Group B and Group C ( P hyperbaric group was significantly higher than in both the isobaric and the hypobaric groups ( P hyperbaric group decreased significantly after the intrathecal injection( P hyperbaric bupivacaine produces major hemodynamic consequences with high cephalad spread and 0. 375% hypobaric bupivacaine has a too long onset time.

Hyperbaric oxygenation was effective in a case of radiation-induced optic neuropathy

International Nuclear Information System (INIS)

Saitoh, Ayumi; Dake, Yoshinori; Amemiya, Tsugio

1995-01-01

A 68-year-old female underwent radiation treatment followed by surgical extirpation for olfactory neuroblastoma in the left ethmoidal sinus. Acute optic neuropathy developed 16 months later in her left eye. The visual acuity was reduced to finger counting at 30 cm. Treatment with systemic corticosteroid and hyperbaric oxygenation for 2 months resulted in improvement in fundus findings and improvement of visual acuity to 0.5. The findings show the potential effectiveness of hyperbaric oxygen therapy for radiation-induced optic neuropathy. (author)

Hyperbaric oxygenation was effective in a case of radiation-induced optic neuropathy

Energy Technology Data Exchange (ETDEWEB)

Saitoh, Ayumi; Dake, Yoshinori; Amemiya, Tsugio [Nagasaki Univ. (Japan). School of Medicine

1995-03-01

A 68-year-old female underwent radiation treatment followed by surgical extirpation for olfactory neuroblastoma in the left ethmoidal sinus. Acute optic neuropathy developed 16 months later in her left eye. The visual acuity was reduced to finger counting at 30 cm. Treatment with systemic corticosteroid and hyperbaric oxygenation for 2 months resulted in improvement in fundus findings and improvement of visual acuity to 0.5. The findings show the potential effectiveness of hyperbaric oxygen therapy for radiation-induced optic neuropathy. (author).

[Spread of spinal anesthesia with 3 different hyperbaric solutions used in Japan].

Science.gov (United States)

Masuda, R; Yokoyama, K; Inoue, T

1998-12-01

We studied the spread of spinal anesthesia with 3 different hyperbaric solutions commercially available in Japan. Percamin-S [0.3% dibucaine in 5% hyperbaric saline] (P), Neo-Percamin.S [0.24% dibucaine with 0.12% T-caine in 9.5% glucose] (N) and 0.5% Tetcaine [tetracaine] in 10% glucose (T) were studied. Two ml of each solution was administered intrathecally using a 25 gauge Quincke needle. Patients (n = 90) were allocated to one of 9 groups receiving 2 ml of P, N or T at L 2-3, L 3-4 or L 4-5 interspace. Both N and T produced significantly higher spread of analgesia than P at any of L 3-4 and L 4-5 interspaces. P and N have the same specific gravity, even though significant differences were found in spread of segmental analgesia. Local anesthesic agents and solvent solutions themselves are considered to influence the spread of spinal anesthesia as the specific gravity of hyperbaric solution does.

Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial

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Usman Anju

2009-03-01

Full Text Available Abstract Background Several uncontrolled studies of hyperbaric treatment in children with autism have reported clinical improvements; however, this treatment has not been evaluated to date with a controlled study. We performed a multicenter, randomized, double-blind, controlled trial to assess the efficacy of hyperbaric treatment in children with autism. Methods 62 children with autism recruited from 6 centers, ages 2–7 years (mean 4.92 ± 1.21, were randomly assigned to 40 hourly treatments of either hyperbaric treatment at 1.3 atmosphere (atm and 24% oxygen ("treatment group", n = 33 or slightly pressurized room air at 1.03 atm and 21% oxygen ("control group", n = 29. Outcome measures included Clinical Global Impression (CGI scale, Aberrant Behavior Checklist (ABC, and Autism Treatment Evaluation Checklist (ATEC. Results After 40 sessions, mean physician CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0008, receptive language (p Conclusion Children with autism who received hyperbaric treatment at 1.3 atm and 24% oxygen for 40 hourly sessions had significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children who received slightly pressurized room air. Trial Registration clinicaltrials.gov NCT00335790

A System Approach to Navy Medical Education and Training. Appendix 16. Aviation Technician.

Science.gov (United States)

1974-08-31

PATTERN OF INTERACTION WITH OTHERS 46 IOBSERVE PATIENT/PERSONNEL IN HYPOBARIC / HYPERBARIC CHAMBER 47 IOBSERVE FOR CLAUSTRAPHOBIC REACTION IN CHAMBER 4B...IREASSURE/CALM APPREHENSIVE (ANXIOUS) PATIENT 41 IREINFORCE PATIENT’S POSITIVE RESPONSE TO THERAPY 42 ISCREEN FOR ARTICLES FORBIDDEN IN HYPOBARIC ... HYPERBARIC CHAMBER 43 ISEAT PERSONNEL AND ALLOCATE NUMBER IN CHAMBER 44 ITALK WITH PATIENT TO ASCERTAIN NEEDS/PROBLEMS 45 ISCREEN PATIENT ON ARRIVAL TO

[Low dose isobaric, hyperbaric, or hypobaric bupivacaine for unilateral spinal anesthesia.].

Science.gov (United States)

Imbelloni, Luiz Eduardo; Beato, Lúcia; Gouveia, Marildo A; Cordeiro, José Antônio

2007-06-01

Unilateral spinal anesthesia has its advantages, especially in patients undergoing outpatient basis surgeries. Low dose, slow speed of administration, and the lateral positioning make easier the unilateral distribution in spinal anesthesia. Isobaric, hyperbaric, and hypobaric solutions of bupivacaine were compared in the unilateral spinal anesthesia in patients undergoing outpatient basis orthopedic surgeries. One hundred and fifty patients were randomly divided in three groups to receive 5 mg of 0.5% isobaric bupivacaine (Iso Group), 5 mg of 0.5% hyperbaric bupivacaine (Hyper Group), or 5 mg of 0.15% hypobaric bupivacaine (Hypo Group). The solutions were administered in the L3-L4 space with the patient in the lateral decubitus and remaining in this position for 20 minutes. Sensitive anesthesia was evaluated by the pin prick test. Motor blockade was determined by the modified Bromage scale. Both blockades were compared with the opposite side and among themselves. There was a significant difference between the side of the surgery and the opposite side in all three groups at 20 minutes, but the frequency of unilateral spinal anesthesia was greater with the hyperbaric and hypobaric solutions. Sensitive and motor blockades were observed in 14 patients in the Iso Group, 38 patients in the Hyper Group, and 40 patients in the Hypo Group. Patients did not develop any hemodynamic changes. Postpuncture headache and transitory neurological symptoms were not observed. Spinal anesthesia with hypobaric and hyperbaric solutions present a higher frequency of unilateral anesthesia. After 20 minutes, isobaric bupivacaine mobilized into cerebrospinal fluid (CSF) resulted in unilateral spinal anesthesia in only 28% of the patients.

Intrathecal isobaric versus hyperbaric bupivacaine for elective caesarean section

International Nuclear Information System (INIS)

Aftab, S.; Ali, H.; Zafar, S.; Sheikh, M.; Sultan, T.

2007-01-01

To compare the results of isobaric bupivacaine (0.5%) with hyperbaric bupivacaine (0.75%) in cases of elective Caesarean Section, in respect of time to sensory analgesia, highest level of sensory block, haemodynamic effects, and complications. Sixty pregnant patients scheduled for elective Caesarean Section. The patients were randomly assigned to receive either 0.5% isobaric bupivacaine (Group-1B) or 0.75% hyperbaric bupivacaine (Group-HB) via intrathecal route. The time of onset of block, highest level of sensory block, cardio-respiratory data, duration of analgesia and complications were recorded during surgery. The time taken to reach T4 sensory analgesia in Group-1B was 6+-6.43 minutes as compared to 6.93+-7.8 minutes in Group-HB, while the highest sensory level achieved in Group-1B was T1 and in Group-HB T2. The lowest systolic blood pressure recorded in Group-1B was 83.27+-12.69 mmHg and in Group-HB 114.33+-13.83 mm Hg, the difference being significant (p<0.05). There was a higher incidence of complications in Group-1B as compared to Group-HB like high spinal analgesia, vomiting and discomfort. Intrathecal block showed a greater reduction in the systolic blood pressure, and associated complications, with Isobaric Bupivacaine as compared to Hyperbaric Bupivacaine. (author)

Effects of hyperbaric oxygen treatment on healing of maxillary distraction osteogenesis in beagle dogs

International Nuclear Information System (INIS)

Kudoh, Atsuo

2008-01-01

Distraction osteogenesis has been widely used even in the craniofacial region. A long fixation time during the consolidation period, however, is a major clinical disadvantage. Hyperbaric oxygen (HBO) has been used to improve healing in ischemic wounds. We have recently started applying hyperbaric oxygen to cleft palate patients after maxillary distraction, but there is little basic evidence. We hypothesized that hyperbaric oxygen would enhance the healing of distraction osteogenesis in the cleft palate model in dogs. A bony segment including a canine was transported proximally into an artificial bone defect in the left palate. Three dogs were treated with hyperbaric oxygen for 20 days just after the distraction and three other dogs underwent only the distraction process (control group). Blood flow of the canine pulp in the bone segment was monitored using a laser Doppler flowmeter throughout the experiment. All the dogs were sacrificed on day 100, and radiological analysis using peripheral quantitative CT and histomorphometric evaluations were performed. Blood flow in the HBO-treated group recovered to the original level about 30 days faster than in the control group (p<0.05). Cortical bone mineral density was significantly higher at the distraction site in the HBO-treated group than in the control group (p<0.05). The histomorphometric analysis revealed that the newly formed bone area was also larger in the HBO-treated group than in the control group (p<0.05). These results suggest that hyperbaric oxygen treatment could be useful for early removal of the distraction device in distraction osteogenesis. (author)

[Effects of hyperbaric oxygen treatment on healing of maxillary distraction osteogenesis in beagle dogs].

Science.gov (United States)

Kudoh, Atsuo

2008-03-01

Distraction osteogenesis has been widely used even in the craniofacial region. A long fixation time during the consolidation period, however, is a major clinical disadvantage. Hyperbaric oxygen (HBO) has been used to improve healing in ischemic wounds. We have recently started applying hyperbaric oxygen to cleft palate patients after maxillary distraction, but there is little basic evidence. We hypothesized that hyperbaric oxygen would enhance the healing of distraction osteogenesis in the cleft palate model in dogs. A bony segment including a canine was transported proximally into an artificial bone defect in the left palate. Three dogs were treated with hyperbaric oxygen for 20 days just after the distraction and three other dogs underwent only the distraction process (control group). Blood flow of the canine pulp in the bone segment was monitored using a laser Doppler flowmeter throughout the experiment. All the dogs were sacrificed on day 100, and radiological analysis using peripheral quantitative CT and histomorphometric evaluations were performed. Blood flow in the HBO-treated group recovered to the original level about 30 days faster than in the control group (p<0.05). Cortical bone mineral density was significantly higher at the distraction site in the HBO-treated group than in the control group (p<0.05). The histomorphometric analysis revealed that the newly formed bone area was also larger in the HBO-treated group than in the control group (p<0.05). These results suggest that hyperbaric oxygen treatment could be useful for early removal of the distraction device in distraction osteogenesis.

Neurotoxicity of subarachnoid hyperbaric bupivacaine in dogs.

Science.gov (United States)

Ganem, E M; Vianna, P T; Marques, M; Castiglia, Y M; Vane, L A

1996-01-01

The study investigated possible neurotoxic effects of increasing concentrations and doses of bupivacaine administered into the subarachnoid space in dogs. Fifty animals were allocated to five experimental groups: G1, control; G2, 5 mg 0.5 bupivacaine in 10% glucose solution; G3, 10 mg of 1% bupivacaine in 10% glucose solution; G4, 20 mg 2% bupivacaine in 10% glucose solution, and G5, 20 mg 2% bupivacaine in water. After 72 hours of observation, the animals were killed and the spinal cords removed for histologic examination by light microscopy. None of the animals showed any neurologic clinical disturbance following recovery from spinal anesthesia. One case of necrosis of nerve tissue was observed in G3 and four in G4. Increasing concentrations and doses of hyperbaric bupivacaine solutions increased the incidence of nerve tissue damage, which did not occur with hypobaric solutions. These results should contribute to the further understanding of neurologic complications following spinal anesthesia when large doses of local anesthetics in hyperbaric solutions are used.

Patient's perspectives on hyperbaric oxygen treatment of osteoradionecrosis

DEFF Research Database (Denmark)

Lee, Anne; Forner, L.; Jansen, E. C.

2014-01-01

Osteoradionecrosis (ORN) is a known complication to radiation therapy for head and neck cancer with a prevalence of 5-7% among radiated patients. Treatment might include dental surgery and reconstruction of the jawbone as well as hyperbaric oxygen treatment (HBOT). HBOT takes place in a closed...

Adding Sufentanil to TAP Block Hyperbaric Bupivacaine Decreases Post-Cesarean Delivery Morphine Consumption

Directory of Open Access Journals (Sweden)

Laleh Eslamian

2016-04-01

Full Text Available Pain management is crucially important in the postoperative period as it increases patient comfort and satisfaction. The primary outcome of present study was to evaluate the effect of sufentanil added to hyperbaric bupivacaine solution 0.25% in transversus abdominis plane (TAP block, on postoperative analgesic consumption. Fifty ASA physical status I–II term primiparous single-tone pregnant women aged 20–40 years scheduled for elective cesarean delivery with Pfannenstiel incision under general anaesthesia were enrolled in this randomized, double-blind, placebo-controlled trial. Ultrasound guided TAP block was performed at the end of surgery. Patients were randomly enrolled into two groups. Patients in the study group received 20 ml of hyperbaric bupivacaine 0.25% plus 1mL of sufentanil on either side while patients in the placebo group were administered 20 ml of hyperbaric bupivacaine 0.25% along with 1mL of placebo. Post-cesarean delivery visual analogue scale (VAS for pain and morphine usage were measured and recorded. The morphine consumption was significantly less in the study group (37.2 ± 16.1 mg than the control group (52.8 ± 16.7 mg, P =0.002.The VAS for pain both in rest and coughing were same in groups. Sufentanil added to 0.25% hyperbaric bupivacaine in TAP block decreases post cesarean delivery morphine consumption.

Hyperbaric oxygen as sole treatment for severe radiation - induced haemorrhagic cystitis

Energy Technology Data Exchange (ETDEWEB)

Dellis, Athanasios, E-mail: aedellis@gmail.com [Department of Surgery, National and Kapodistrian University of Athens, Aretaieion Academic Hospital, Athens (Greece); Papatsoris, Athanasios; Deliveliotis, Charalambos; Skolarikos, Andreas [Department of Urology, University of Athens, Sismanoglio General Hospital, Athens (Greece); Kalentzos, Vasileios [Department of Diving and Hyperbaric Oxygen, Naval and Veterans Hospital, Athens (Greece)

2017-05-15

Purpose: To examine the safety and efficacy of hyperbaric oxygen as the primary and sole treatment for severe radiation-induced haemorrhagic cystitis. Materials and methods: Hyperbaric oxygen was prospectively applied as primary treatment in 38 patients with severe radiation cystitis. Our primary endpoint was the incidence of complete and partial response to treatment, while the secondary endpoints included the duration of response, the correlation of treatment success-rate to the interval between the onset of haematuria and initiation of therapy, blood transfusion need and total radiation dose, the number of sessions to success, the avoidance of surgery and the overall survival. Results: All patients completed therapy without complications with a mean follow-up of 29.33 months. Median number of sessions needed was 33. Complete and partial response rate was 86.8% and 13.2%, respectively. All 33 patients with complete response received therapy within 6 months of the haematuria onset. One patient needed cystectomy, while 33 patients were alive at the end of follow-up. Conclusions: Our study suggests the early primary use of hyperbaric oxygen for radiation-induced severe cystitis as an effective and safe treatment option. (author)

Large Acrylic Spherical Windows In Hyperbaric Underwater Photography

Science.gov (United States)

Lones, Joe J.; Stachiw, Jerry D.

1983-10-01

Both acrylic plastic and glass are common materials for hyperbaric optical windows. Although glass continues to be used occasionally for small windows, virtually all large viewports are made of acrylic. It is easy to uderstand the wide use of acrylic when comparing design properties of this plastic with those of glass, and glass windows are relatively more difficult to fabricate and use. in addition there are published guides for the design and fabrication of acrylic windows to be used in the hyperbaric environment of hydrospace. Although these procedures for fabricating the acrylic windows are somewhat involved, the results are extremely reliable. Acrylic viewports are now fabricated to very large sizes for manned observation or optical quality instrumen tation as illustrated by the numerous acrylic submersible vehicle hulls for hu, an occupancy currently in operation and a 3600 large optical window recently developed for the Walt Disney Circle Vision under-water camera housing.

Elimination of CT-detected gas bubbles derived from decompression illness with abdominal symptoms after a short hyperbaric oxygen treatment in a monoplace chamber: a case report.

Science.gov (United States)

Oyaizu, Takuya; Enomoto, Mitsuhiro; Tsujimoto, Toshihide; Kojima, Yasushi; Okawa, Atsushi; Yagishita, Kazuyoshi

2017-01-01

We report the case of a 54-year-old male compressed-air worker with gas bubbles detected by computed tomography (CT). He had complained of strong abdominal pain 30 minutes after decompression after working at a pressure equivalent to 17 meters of sea water for three hours. The initial CT images revealed gas bubbles in the intrahepatic portal vein, pulmonary artery and bilateral femoral vein. After the first hyperbaric oxygen treatment (HBO₂ at 2.5 atmospheres absolute/ATA for 150 minutes), no bubbles were detected on repeat CT examination. The patient still exhibited abdominal distension, mild hypesthesia and slight muscle weakness in the upper extremities. Two sessions of U.S. Navy Treatment Table 6 (TT6) were performed on Days 6 and 7 after onset. The patient recovered completely on Day 7. This report describes the important role of CT imaging in evaluating intravascular gas bubbles as well as eliminating the diagnosis of other conditions when divers or compressed-air workers experience uncommon symptoms of decompression illness. In addition, a short treatment table of HBO₂ using non-TT6 HBO₂ treatment may be useful to reduce gas bubbles and the severity of decompression illness in emergent cases. Copyright© Undersea and Hyperbaric Medical Society.

Single-dose relative biological effectiveness and toxicity studies under conditions of hypothermia and hyperbaric oxygen

International Nuclear Information System (INIS)

Hering, E.R.; Blekkenhorst, G.; Harrison, G.G.; Morrell, D.; Korrubel, J.; Gregory, A.; Phillips, J.; Manca, V.; Sealy, R.; Cape Town Univ.

1986-01-01

An approach to using hyperbaric oxygen with radiation in a clinical situation has been described in the preceding paper in this issue. To ascertain whether there might be a change in the relative biological effectiveness of radiation on normal mammalian tissue treated under conditions of hypothermia and hyperbaric oxygen, the acute reaction to radiation of pig skin was studied. A single dose enhancement ratio at the erythema reaction level of 1.4+-0.08 was obtained when compared with irradiation at normal body temperature in air. The authors studied also a series of antioxidant enzymes in rat liver and lung after exposure to hypothermia and hyperbaric oxygen. Enzyme changes were such as to combat oxygen toxicity which might develop as a result of the pre-treatment. (author)

Report on computation of repetitive hyperbaric-hypobaric decompression tables

Science.gov (United States)

Edel, P. O.

1975-01-01

The tables were constructed specifically for NASA's simulated weightlessness training program; they provide for 8 depth ranges covering depths from 7 to 47 FSW, with exposure times of 15 to 360 minutes. These tables were based up on an 8 compartment model using tissue half-time values of 5 to 360 minutes and Workmanline M-values for control of the decompression obligation resulting from hyperbaric exposures. Supersaturation ratios of 1.55:1 to 2:1 were used for control of ascents to altitude following such repetitive dives. Adequacy of the method and the resultant tables were determined in light of past experience with decompression involving hyperbaric-hypobaric interfaces in human exposures. Using these criteria, the method showed conformity with empirically determined values. In areas where a discrepancy existed, the tables would err in the direction of safety.

Hyperbaric oxygen in the treatment of a diabetic foot ulcer.

LENUS (Irish Health Repository)

Davenport, Colin

2011-02-01

Although simultaneous pancreas and kidney transplant improves most complications of type 1 diabetes, suppression of the immune system increases the risk for infection. The authors report the case of a patient who, despite receiving a simultaneous pancreas and kidney transplant, subsequently developed neuro-ischemic ulcers of his right foot requiring repeated amputations. He then developed an infected ulcer of his remaining right big toe, with significant implications for his mobility. This ulcer proved resistant to multiple courses of antibiotics and care in a specialist foot clinic but resolved completely following a course of hyperbaric oxygen therapy. The role of hyperbaric oxygen in diabetic foot ulcers is not yet fully established but should be considered in resistant cases with vascular insufficiency and a significant infective component.

Hyperbaric oxygen in the treatment of a diabetic foot ulcer.

LENUS (Irish Health Repository)

Davenport, Colin

2012-02-01

Although simultaneous pancreas and kidney transplant improves most complications of type 1 diabetes, suppression of the immune system increases the risk for infection. The authors report the case of a patient who, despite receiving a simultaneous pancreas and kidney transplant, subsequently developed neuro-ischemic ulcers of his right foot requiring repeated amputations. He then developed an infected ulcer of his remaining right big toe, with significant implications for his mobility. This ulcer proved resistant to multiple courses of antibiotics and care in a specialist foot clinic but resolved completely following a course of hyperbaric oxygen therapy. The role of hyperbaric oxygen in diabetic foot ulcers is not yet fully established but should be considered in resistant cases with vascular insufficiency and a significant infective component.

Effect of hyperbaric air on endotoxin from Bacteroides fragilis strains

Czech Academy of Sciences Publication Activity Database

Chmelař, D.; Kašíková, A.; Martineková, P.; Hájek, M.; Rozložník, M.; Brabec, Marek; Janečková, J.; Vobejdová, J.; Čižnár, I.

2018-01-01

Roč. 63, č. 3 (2018), s. 283-290 ISSN 0015-5632 Institutional support: RVO:67985807 Keywords : endotoxin * hyperbaric condition Subject RIV: EE - Microbiology, Virology Impact factor: 1.521, year: 2016

Comparative study of intrathecal hyperbaric versus isobaric ropivacaine: A randomized control trial

Directory of Open Access Journals (Sweden)

Rajni Gupta

2013-01-01

Full Text Available Background: Hyperbaric ropivacaine produce more reliable sensory and motor block, with faster onset, better quality of muscles relaxation than isobaric ropivacaine. So, this study was designed to compare the efficacy of hyperbaric ropivacaine with isobaric ropivacaine in patients undergoing lower abdominal surgery. Methods: A randomized controlled double blind study in two groups of patients. group A (n=35 received 3 ml of isobaric ropivacaine 6 mg/ml (18 mg. Group B (n=35 received 3 ml of hyperbaric ropivacaine 6 mg/ml (18 mg. The onset and duration of sensory block at dermatome level T10, maximum upper and lower spread of sensory block, intensity, and duration of motor block were recorded. Statistical Analysis: Block characteristics were compared using the two-tailed Mann - Whitney U-test. The proportion of side effects was compared using the Chi-square test. Results: The median time of onset of sensory block at the T10 dermatome was 4.4±1.3 min in group B and 6.0±1.03 min in group A. The median time to maximum block height was 16.7±3.7 min in group A and 12.03±1.96 min in group B. The median duration of complete motor recovery (B0 was significantly shorter in the heavy ropivacaine group (166.5±11.7 min compared with the isobaric ropivacaine group (192.9±9.6 min. Conclusions: Intrathecal hyperbaric ropivacaine provides more rapid, adequate, and good quality of sensory and motor block with rapid post-operative recovery as compare to isobaric ropivacaine.

Hyperbaric storage at room temperature for food preservation: A study in strawberry juice

OpenAIRE

Segovia-Bravo, Kharla A.; Guignon, Bérengère; Bermejo-Prada, Ana; Sanz Martínez, Pedro D.; Otero, Laura

2012-01-01

Hyperbaric storage at room temperature was evaluated as a new food preservation method. To do that, strawberry juices maintained at different pressure levels (0.1, 25, 100 or 220 MPa) and 20°C for 15 days were compared to raw and thermally pasteurized samples stored at atmospheric pressure and 5°C for the same period. Hyperbaric storage reduced the initial microbial load of the juices by more than 2 log units to levels below the limit of detection. Moreover, pressure was effective to attenuat...

Abdominal girth and vertebral column length aid in predicting intrathecal hyperbaric bupivacaine dose for elective cesarean section.

Science.gov (United States)

Wei, Chang-Na; Zhou, Qing-He; Wang, Li-Zhong

2017-08-01

Currently, there is no consensus on how to determine the optimal dose of intrathecal bupivacaine for an individual undergoing an elective cesarean section. In this study, we developed a regression equation between intrathecal 0.5% hyperbaric bupivacaine volume and abdominal girth and vertebral column length, to determine a suitable block level (T5) for elective cesarean section patients.In phase I, we analyzed 374 parturients undergoing an elective cesarean section that received a suitable dose of intrathecal 0.5% hyperbaric bupivacaine after a combined spinal-epidural (CSE) was performed at the L3/4 interspace. Parturients with T5 blockade to pinprick were selected for establishing the regression equation between 0.5% hyperbaric bupivacaine volume and vertebral column length and abdominal girth. Six parturient and neonatal variables, intrathecal 0.5% hyperbaric bupivacaine volume, and spinal anesthesia spread were recorded. Bivariate line correlation analyses, multiple line regression analyses, and 2-tailed t tests or chi-square test were performed, as appropriate. In phase II, another 200 parturients with CSE for elective cesarean section were enrolled to verify the accuracy of the regression equation.In phase I, a total of 143 parturients were selected to establish the following regression equation: YT5 = 0.074X1 - 0.022X2 - 0.017 (YT5 = 0.5% hyperbaric bupivacaine volume for T5 block level; X1 = vertebral column length; and X2 = abdominal girth). In phase II, a total of 189 participants were enrolled in the study to verify the accuracy of the regression equation, and 155 parturients with T5 blockade were deemed eligible, which accounted for 82.01% of all participants.This study evaluated parturients with T5 blockade to pinprick after a CSE for elective cesarean section to establish a regression equation between parturient vertebral column length and abdominal girth and 0.5% hyperbaric intrathecal bupivacaine volume. This equation can accurately

Laparoscopic cholecystectomy under spinal anesthesia: comparative study between conventional-dose and low-dose hyperbaric bupivacaine

Directory of Open Access Journals (Sweden)

Imbelloni LE

2011-10-01

Full Text Available Luiz Eduardo Imbelloni1, Raphael Sant'Anna2, Marcos Fornasari2, José Carlos Fialho21Department of Anesthesiology, Faculty of Medecine Nova Esperança, Hospital de Mangabeira, João Pessoa, 2Hospital Rio Laranjeiras, Rio de Janeiro, BrazilBackground: Laparoscopic cholecystectomy has the advantages of causing less postoperative pain and requiring a short hospital stay, and therefore is the treatment of choice for cholelithiasis. This study was designed to compare spinal anesthesia using hyperbaric bupivacaine given as a conventional dose by lumbar puncture or as a low-dose by thoracic puncture.Methods: A total of 140 patients with symptomatic gallstone disease were randomized to undergo laparoscopic cholecystectomy with low-pressure CO2 pneumoperitoneum under spinal anesthesia using either conventional lumbar spinal anesthesia (hyperbaric bupivacaine 15 mg and fentanyl 20 mg or low-dose thoracic spinal anesthesia (hyperbaric bupivacaine 7.5 mg and fentanyl 20 µg. Intraoperative parameters, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two treatment groups.Results: All procedures were completed under spinal anesthesia, with no cases needing conversion to general anesthesia. Values for time for block to reach the T3 dermatomal level, duration of motor and sensory block, and hypotensive events were significantly lower with low-dose bupivacaine. Postoperative pain was higher for low-dose hyperbaric bupivacaine at 6 and 12 hours. All patients were discharged after 24 hours. Follow-up 1 week postoperatively showed all patients to be satisfied and to be keen advocates of spinal anesthesia.Conclusion: Laparoscopic cholecystectomy can be performed successfully under spinal anesthesia. A small dose of hyperbaric bupivacaine 7.5 mg and 20 µg fentanyl provides adequate spinal anesthesia for laparoscopy and, in comparison with hyperbaric bupivacaine 15% and fentanyl 20 µg, causes markedly

Hyperbaric oxygen therapy or hydroxycobalamin attenuates surges in brain interstitial lactate and glucose; and hyperbaric oxygen improves respiratory status in cyanide-intoxicated rats

DEFF Research Database (Denmark)

Lawson-Smith, P; Olsen, Niels Vidiendal; Hyldegaard, O

2011-01-01

Cyanide (CN) intoxication inhibits cellular oxidative metabolism and may result in brain damage. Hydroxycobalamin (OHCob) is one among other antidotes that may be used following intoxication with CN. Hyperbaric oxygen (HBO2) is recommended when supportive measures or antidotes fail. However...

Bubble number saturation curve and asymptotics of hypobaric and hyperbaric exposures.

Science.gov (United States)

Wienke, B R

1991-12-01

Within bubble number limits of the varying permeability and reduced gradient bubble models, it is shown that a linear form of the saturation curve for hyperbaric exposures and a nearly constant decompression ratio for hypobaric exposures are simultaneously recovered from the phase volume constraint. Both limits are maintained within a single bubble number saturation curve. A bubble term, varying exponentially with inverse pressure, provides closure. Two constants describe the saturation curve, both linked to seed numbers. Limits of other decompression models are also discussed and contrasted for completeness. It is suggested that the bubble number saturation curve thus provides a consistent link between hypobaric and hyperbaric data, a link not established by earlier decompression models.

Application of hyperbaric oxygen therapy in the rehabilitation of patients after surgical correction of the penile urethral strictures

Directory of Open Access Journals (Sweden)

Kotenko К.V.

2013-12-01

Full Text Available The aim of the article is to examine the impact and justify the use of hyperbaric oxygenation in the complex rehabilitation of patients after surgery for penile urethral strictures. Material and Methods. A group of 37 patients were examined who underwent various reconstructive operations on the urethra, 16 of which in the postoperative period in addition to conventional therapy conducted hyperbaric oxygenation. Results. It is shown that the use of hyperbaric oxygenation in the early postoperative period in patients undergoing replacement plastic of urethra can reduce the incidence of postoperative complications, and reduced the time of urethral drainage. Conclusion. An integrated approach with the use of hyperbaric oxygen therapy in the rehabilitation of patients undergoing extended replacement plastic of penile urethral strictures, reduces the amount of potential effect-dependent postoperative complications, which generally leads to shorter hospital stay after surgical treatment.

Effect of hyperbaric oxygenation on carbohydrate metabolism protein synthesis in the myocardium during sustained hypodynamia

Science.gov (United States)

Makarov, G. A.

1980-01-01

Glycolysis and the intensity of protein synthesis were studied in 140 white male rats in subcellular fractions of the myocardium during 45 day hypodynamia and hyperbaric oxygenation. Hypodynamia increased: (1) the amount of lactic acids; (2) the amount of pyruvic acid; (3) the lactate/pyruvate coefficient; and (4) the activities of aldolase and lactate dehydrogenase. Hyperbaric oxygenation was found to have a favorable metabolic effect on the animals with hypodynamia.

Haemodynamic preservation in cesarean sections by low dose 0.5% hyperbaric bupivacaine

International Nuclear Information System (INIS)

Ahmad, M.; Ahmad, M.

2017-01-01

Spinal anaesthesia is technique of choice for caesarean sections and hyperbaric bupivacaine is a recommended drug for this popular block. Although safe but few complications are haemodynamic changes, postdural puncture headache, cauda equina syndrome and radiculopathy. However, hypotension remains the common side effect which is believed to occur in 95% of patients resulting in reduction of uteroplacental perfusion causing foetal acid-base abnormalities. Various doses regimes are in safe anaesthesia practice for providing regional anaesthesia for such patients with least detrimental effects on foetal outcome. This study was carried out to find the effective dose of 0.5% hyperbaric bupivacaine in caesarean section patients by comparing two different doses. Methods: After enrolling two hundred patients of C section (Caesarean section) for this study, 90 patients were selected to compare the effects of 0.5% hyperbaric bupivacaine. Group A (n=45) received 10 mg of drug while group B (n=45) received 12 mg for spinal anaesthesia. Onset of block, sensory and motor level, haemodynamic changes, surgery time, maternal satisfaction, APGAR score and incidence of complications were compared in two groups. Results: Blood pressure decreases were less in Group A (p-0.074) but not statistically significant. Phenylephrine for hypotension was given to 17% vs 5% in group B. Maternal satisfaction was found to be better in group B 33 vs 17 but was statistically significant (p 0.034). 2% patients had bradycardia in group A which was treated by atropine. No complications were reported in either group. Conclusion: Doses of hyperbaric bupivacaine for spinal anaesthesia in caesarean sections must be at least 12 mg because it produces excellent anaesthesia and maternal satisfaction without complications. (author)

Hyperbaric oxygen therapy as treatment for bilateral arm compartment syndrome after CrossFit: case report and literature review.

Science.gov (United States)

Mendes, Adriano Fernando; Neto, José da Mota; Heringer, Erica Maciel; de Simoni, Leandro Furtado; Pires, Diego Demolinari; Labronici, Pedro José

2018-01-01

CrossFit is a physical fitness program characterized by high-intensity workouts that can be associated with serious injury. Acute compartment syndrome in the upper limbs is a rare occurrence. It may occur after intense physical exercise, and its usual treatment is surgical. Hyperbaric oxygen therapy is a treatment described as adjunctive in cases of compartmental syndrome. We describe the case of a CrossFit practitioner who, after intense training, developed progressive symptoms of rhabdomyolysis and acute bilateral arm compartment syndrome, who was successfully treated with hyperbaric oxygen therapy and required no fasciotomy as surgical treatment. Acute compartment syndrome in the arms after intense physical exercise is a rare occurrence that should be suspected by practitioners of physical activity experiencing intense, disproportionate and progressive pain. In the case presented, hyperbaric oxygen therapy was successfully used in the treatment of the disorder, with satisfactory progress, and without the need for a surgical fasciotomy as therapy. Copyright© Undersea and Hyperbaric Medical Society.

Hyperbaric oxygen in the treatment of radiation-induced optic neuropathy

International Nuclear Information System (INIS)

Guy, J.; Schatz, N.J.

1986-01-01

Four patients with radiation-induced optic neuropathies were treated with hyperbaric oxygen. They had received radiation therapy for treatment of pituitary tumors, reticulum cell sarcoma, and meningioma. Two presented with amaurosis fugax before the onset of unilateral visual loss and began hyperbaria within 72 hours after development of unilateral optic neuropathy. Both had return of visual function to baseline levels. The others initiated treatment two to six weeks after visual loss occurred in the second eye and had no significant improvement of vision. Treatment consisted of daily administration of 100% oxygen under 2.8 atmospheres of pressure for 14-28 days. There were no medical complications of hyperbaria. While hyperbaric oxygen is effective in the treatment of radiation-induced optic neuropathy, it must be instituted within several days of deterioration in vision for restoration of baseline function

Characterisation of fume from hyperbaric welding operations

Energy Technology Data Exchange (ETDEWEB)

Ross, John A S; Semple, Sean [Environmental and Occupational Medicine, University of Aberdeen (United Kingdom); Duffin, Rodger [ELEGI Colt Laboratory, University of Edinburgh (United Kingdom); Kelly, Frank [Lung Biology Group, Kings College, University of London (United Kingdom); Seldmann, Joerg; Raab, Andrea, E-mail: j.a.ross@abdn.ac.u [Trace Element Speciation Laboratory, University of Aberdeen (United Kingdom)

2009-02-01

We report preliminary work characterising dust from hyperbaric welding trials carried out at increased pressure in a helium and oxygen atmosphere. Particle size and concentration were measured during welding. Samples for quartz and metal analysis and toxicity assessment were taken from a filter in the local fume extraction system. The residue of dust after metal extraction by nitric acid in hydrogen peroxide predominantly a non-metallic white powder assumed to be dust from welding rod coatings and thermal insulation material. Metallic analysis showed predominantly calcium, from the welding rod coating, and period 4 transition metals such as iron, manganese, magnesium and titanium (inductively coupled mass spectrometry, Agilent 7500c). The presence of zirconium indicated a contribution from grinding. The fume was nanoparticulate in nature with a mean particle diameter of 20-30 nm (MSI Inc WPS 1000XP). It showed an intermediate level of oxidative potential regarding the low-molecular weight respiratory tract lining fluid antioxidants ascorbate and glutathione and caused release of the inflammatory marker IL-8 in a human lung A 549 epithelial cell culture with no indication of cytotoxicity. The study findings have strong implications for the measurement techniques needed to assess fume exposure in hyperbaric welding and the provision of respiratory protection.

Latent Presentation of Decompression Sickness After Altitude Chamber Training in an Active Duty Flier.

Science.gov (United States)

Gentry, James; Rango, Juan; Zhang, Jianzhong; Biedermann, Shane

2017-04-01

Decompression sickness (DCS) is a potential danger and risk for both divers and aircrew alike. DCS is also a potential side effect of altitude (hypobaric) chamber training as well and can present long after training occurs. Literature review shows that altitude chamber induced DCS has approximately a 0.25% incidence. A 32-yr-old, active duty military member developed symptoms of DCS 3 h after his hypobaric chamber training. Unfortunately, he did not seek treatment for DCS until 48 h after the exposure. His initial treatment included ground level oxygen therapy for 30 min at 12 L of oxygen per minute using a nonrebreathing mask. He achieved complete symptom resolution and was returned to duty. However, 12 d after his initial Flight Medicine evaluation, the patient returned complaining of a right temporal headache, multijoint pains, and fatigue. He was treated in the hyperbaric chamber and had complete resolution of symptoms. He was returned to flying status and 5 mo later denied any return of symptoms. Hypobaric chamber familiarity training is a requirement for all military aircrew personnel to allow them assess their ability to identify symptoms of hypoxia. This training method is not only costly to maintain, but it also places aircrew and chamber technicians at risk for potential long-term side effects from failed recompression treatment of DCS. We are presenting a case of recurrent DCS symptoms 12 d after initial ground level oxygen therapy.Gentry J, Rango J, Zhang J, Biedermann S. Latent presentation of decompression sickness after altitude chamber training in an active duty flier. Aerosp Med Hum Perform. 2017; 88(4):427-430.

Prilocaine hydrochloride 2% hyperbaric solution for intrathecal injection: a clinical review

Directory of Open Access Journals (Sweden)

Manassero A

2017-03-01

Full Text Available Alberto Manassero,1 Andrea Fanelli2 1Department of Emergency and Critical Care, Anesthesia and Intensive Care Unit, S. Croce e Carle Hospital, Cuneo, 2Department of Medical and Surgical Sciences, Anesthesia and Intensive Care Unit, Policlinico S. Orsola-Malpighi, Bologna, Italy Abstract: Prilocaine is a local anesthetic characterized by intermediate potency and duration and fast onset of action. As hyperbaric formulation of 5% solution, it was introduced and has been successfully used for spinal anesthesia since 1960. A new formulation of 2% plain and hyperbaric solution is currently available in Europe. Because of its lower incidence of transient neurological symptoms, prilocaine is suggested as substitute to lidocaine and mepivacaine in spinal anesthesia for ambulatory surgery, as well as a suitable alternative to low doses of long-acting local anesthetics. The National Library of Medicine database, the Excerpta Medica database, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials database, were searched for the period 1970 to September 2016, with the aim to identify studies evaluating the intrathecal use of 2% prilocaine. A total of 13 randomized clinical trials (RCTs, 1 observational study, 2 dose finding, and 4 systematic reviews has been used for this review. The studies evaluated showed that 2% hyperbaric prilocaine due to a favorable anesthetic and safety profile is an alternative drug to lidocaine and mepivacaine for spinal anesthesia of intermediate or short duration. In comparison with plain solutions, hyperbaricity remarkably accelerates the onset and offset times of intrathecal 2% prilocaine. Literature suggests a dose ranging between 40 and 60 mg of prilocaine for lower extremities and lower abdominal procedures lasting up to 90 min, whereas a dose ranging from 10 to 30 mg is appropriate for perineal surgery. Readiness for discharge occurs in ~4 h from spinal administration. Keywords

Prophylactic hyperbaric oxygen treatment and rat spinal cord re-irradiation.

NARCIS (Netherlands)

Sminia, P.; Kleij, van der AJ; Carl, UM; Feldmeier, JJ; Hartmann, KA

2003-01-01

Normal tissue injury may lead to severe, life threatening, late side effects after therapeutic use of irradiation. Neurological complications caused by radiation of the spinal cord are ascribed to progressive, irreversible damage to the vasculature. Hyperbaric oxygen (HBO) is known to induce

Treatment of portal venous gas embolism with hyperbaric oxygen after accidental ingestion of hydrogen peroxide: a case report and review of the literature.

Science.gov (United States)

Papafragkou, Sotirios; Gasparyan, Anna; Batista, Richard; Scott, Paul

2012-07-01

It is well known that hydrogen peroxide ingestion can cause gas embolism. To report a case illustrating that the definitive, most effective treatment for gas embolism is hyperbaric oxygen therapy. We present a case of a woman who presented to the Emergency Department with acute abdominal pain after an accidental ingestion of concentrated hydrogen peroxide. Complete recovery from her symptoms occurred quickly with hyperbaric oxygen therapy. This is a case report of the successful use of hyperbaric oxygen therapy to treat portal venous gas embolism caused by hydrogen peroxide ingestion. Hyperbaric oxygen therapy can be considered for the treatment of symptomatic hydrogen peroxide ingestion. Copyright © 2012 Elsevier Inc. All rights reserved.

[The heart in extreme sports: hyperbaric activity and microgravity].

Science.gov (United States)

Berrettini, Umberto; Landolfi, Angelo; Patteri, Giovanna

2008-10-01

The study of the cardiovascular and respiratory modifications in extreme environments could be useful for the understanding of the adaptive mechanisms of the body in particular conditions. The knowledge of how different environmental conditions in terms of extreme pressure, temperature and gravity modify the neurovegetative and cardiovascular system could be useful in daily practice for hypobaric and hyperbaric sports.

Monitoring cardiac output during hyperbaric oxygen treatment of haemodynamically unstable patients

DEFF Research Database (Denmark)

Hansen, Marco Bo; Treschow, Frederik; Skielboe, Martin

2013-01-01

Patients suffering from necrotizing fasciitis (NF) are often haemodynamically unstable and require extended monitoring of cardiovascular parameters; yet this is limited during hyperbaric oxygen treatment (HBOT). We aimed to evaluate the use and safety of transoesophageal Doppler (TED) monitoring ...

Temporal changes in tumor oxygenation and perfusion upon normo- and hyperbaric inspiratory hyperoxia

Energy Technology Data Exchange (ETDEWEB)

Thews, Oliver [University of Halle, Institute of Physiology, Halle (Saale) (Germany); Vaupel, Peter [University Medical Center Mainz, Department of Radiooncology and Radiotherapy, Tumor Pathophysiology Section, Mainz (Germany)

2016-03-15

Inspiratory hyperoxia under hyperbaric conditions has been shown to effectively reduce tumor hypoxia and to improve radiosensitivity. However, applying irradiation (RT) under hyperbaric conditions is technically difficult in the clinical setting since RT after decompression may be effective only if tumor pO{sub 2} remains elevated for a certain period of time. The aim of the present study was to analyze the time course of tumor oxygenation and perfusion during and after hyperbaric hyperoxia. Tumor oxygenation, red blood cell (RBC) flux for perfusion monitoring, and vascular resistance were assessed continuously in experimental rat DS-sarcomas by polarographic catheter electrodes and laser Doppler flowmetry at 1 and 2 atm (bar) of environmental pressure during breathing of pure O{sub 2} or carbogen (95 % O{sub 2} + 5 % CO{sub 2}). During room air breathing, the tumor pO{sub 2} followed very rapidly within a few minutes the change of the ambient pressure during compression or decompression. With O{sub 2} breathing under hyperbaric conditions, the tumor pO{sub 2} increased more than expected based on the rise of the environmental pressure, although the time course was comparably rapid. Breathing carbogen, the tumor pO{sub 2} followed with a slight delay of the pressure change, and within 10 min after decompression the baseline values were reached again. RBC flux increased during carbogen breathing but remained almost constant with pure O{sub 2}, indicating a vasodilation (decrease in vascular resistance) with carbogen but a vasoconstriction (increase in vascular resistance) with O{sub 2} during hyperbaric conditions. Since the tumor pO{sub 2} directly followed the environmental pressure, teletherapy after hyperbaric conditions does not seem to be promising as the pO{sub 2} reaches baseline values again within 5-10 min after decompression. (orig.) [German] Inspiratorische Hyperoxie unter hyperbaren Bedingungen reduziert sehr effektiv die Tumorhypoxie und erhoeht die

Hyperbaric oxygen treatment augments tobramycin efficacy in experimental staphylococcus aureus endocarditis

DEFF Research Database (Denmark)

Lerche, C J; Christophersen, L J; Kolpen, M

2017-01-01

BACKGROUND: S. aureus infective endocarditis (IE) is a serious disease an in-hospital mortality of up to 40%. Improvements of effects of antibiotics and host responses could potentially benefit outcomes. Hyperbaric oxygen treatment (HBOT) represents an adjunctive therapeutic option. We evaluated...

Examination of dexamethasone sodium sulfate and hyperbaric oxygenation in experimentally produced cerebral edema. With special reference to their combination

Energy Technology Data Exchange (ETDEWEB)

Kanaya, H; Onodera, H; Watanabe, M; Kamata, K [Iwate Medical Coll., Morioka (Japan). School of Medicine

1975-06-01

Dexamethasone sodium sulfate and hyperbaric oxygenation were used for experimentally produced cerebral edema for the examination of the water content of the brain and cerebrovascular permeability using /sup 203/Hg as the tracer. Although dexamethasone starts lowering vascular permeability of the edematous brain at one hour after the intravenous injection, a lapse of 24 hours is required until the water content returns to normal. Although hyperbaric oxygenation dose not reduce cerebrovascular permeability, it brings back the water content of the brain to normal immediately after pressurization. Since the combination of dexamethasone and hyperbaric oxygenation maintains the water content of the brain almost normal throughout the entire process, it is ideal for the treatment of cerebral edema.

Combined Use of Hyperbaric and Hypobaric Ropivacaine Significantly Improves Hemodynamic Characteristics in Spinal Anesthesia for Caesarean Section: A Prospective, Double-Blind, Randomized, Controlled Study

OpenAIRE

Quan, ZheFeng; Tian, Ming; Chi, Ping; Li, Xin; He, HaiLi; Luo, Chao

2015-01-01

Purpose To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study. Methods Parturients (n = 136) undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A) or hyperbaric ropivacaine (Group B). Outcome measures were: hemodynamic characteristics, maximum heig...

Hyperbaric index in the primary prevention of hypertensive complications in high-risk pregnancy.

Science.gov (United States)

Otero González, Alfonso; Uribe Moya, Silvia; Arenas Moncaleano, Ivan Gilberto; Borrajo Prol, María Paz; García García, María Jesús; López Sánchez, Luis

2015-01-01

Preeclampsia (PE) is a major cause of fetal morbidity and mortality. In the Western World, PE affects 2-7% of pregnancies and is responsible for 50,000 deaths annually. Early detection is a priority as it can change the clinical course, but there are no biomarkers or instrumental methods with high sensitivity and specificity. Only the hyperbaric index has a sensitivity and specificity of 99% for early identification of pregnant women at risk of developing PE, but its use is not widespread. To assess the usefulness of the hyperbaric index in the primary prevention of hypertensive pregnancy complications in a public healthcare area. This is a retrospective study of pregnancies that occurred in our area during the period 2007-2012 (N=11,784). The diagnosis was established by the hyperbaric index and pregnant women at risk were treated with ASA at night. In pregnant patients referred to the nephrology clinic (38.2%), diagnosed as high-risk for PE, and treated with 100mg ASA/night (from week 17), the incidence of PE episodes was reduced by 96.94. Copyright © 2015 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

Resuscitation by hyperbaric exposure from a venous gas emboli following laparoscopic surgery

DEFF Research Database (Denmark)

Kjeld, Thomas; Hansen, Egon G; Holler, Nana G

2012-01-01

Venous gas embolism is common after laparoscopic surgery but is only rarely of clinical relevance. We present a 52 year old woman undergoing laparoscopic treatment for liver cysts, who also underwent cholecystectomy. She was successfully extubated. However, after a few minutes she developed cardiac......, could have contributed to the formation of the intravascular gas emboli. We conclude that persistent resuscitation followed by hyperbaric oxygen treatment after venous gas emboli contributed to the elimination of intravascular bubbles and the favourable outcome for the patient....... arrest due to a venous carbon dioxide (CO2) embolism as identified by transthoracic echocardiography and aspiration of approximately 7 ml of gas from a central venous catheter. She was resuscitated and subsequently treated with hyperbaric oxygen to reduce the size of remaining gas bubbles. Subsequently...

Clinical Potential of Hyperbaric Pressure-Treated Whey Protein

Science.gov (United States)

Piccolomini, André F.; Kubow, Stan; Lands, Larry C.

2015-01-01

Whey protein (WP) from cow’s milk is a rich source of essential and branched chain amino acids. Whey protein isolates (WPI) has been demonstrated to support muscle accretion, antioxidant activity, and immune modulation. However, whey is not readily digestible due to its tight conformational structure. Treatment of WPI with hyperbaric pressure results in protein unfolding. This enhances protein digestion, and results in an altered spectrum of released peptides, and greater release of essential and branched chain amino acids. Pressurized whey protein isolates (pWPI), through a series of cell culture, animal models and clinical studies, have been demonstrated to enhance muscle accretion, reduce inflammation, improve immunity, and decrease fatigue. It is also conceivable that pWPI would be more accessible to digestive enzymes, which would allow for a more rapid proteolysis of the proteins and an increased or altered release of small bioactive peptides. The altered profile of peptides released from WP digestion could thus play a role in the modulation of the immune response and tissue glutathione (GSH) concentrations. The research to date presents potentially interesting applications for the development of new functional foods based on hyperbaric treatment of WPI to produce products with more potent nutritional and nutraceutical properties. PMID:27417773

Four-years experience with monitoring of persons at the treatment of children patients with neuroblastoma by 131I-MIBG combination with hyperbaric oxygen therapy

International Nuclear Information System (INIS)

Hermanska, J.; Zimak, J.; Paskova, Z.; Dosel, P.

2001-01-01

Treatment of children patients with neuroblastoma by 131 I-MIBG in combination with hyperbaric oxygen therapy (HBO) started in the Czech Republic in 1997. Estimation of radiation load from extemal irradiation plays very important role in the treatment scheme elaborated at the Department of Nuclear Medicine. According to this scheme, activities of 5.5 GBq and 3.7 GBq are administered at the first and repeated therapies,respectively. 3 rd , 4 th , 5 th and 6 th day after the administration patients undergo HBO in the Institute of Aviation Medicine Prague. Activity administration and following care are realised at the bed station of the Department of Nuclear Medicine, which is the workplace of III. category with unsealed radionuclide sources. Real dose equivalents were checked during the reported four-year period. Members of both groups were equipped by personal digital dosemeters STEPHEN 6000 for inspection. From the presented results, the following conclusions can be drawn: (1) Monitoring of family members has to be performed in spite of the fact that exceeding of equivalent dose of 5 mSv is non-realistic. Unexpected situation concerning behaviour of both parents and children cannot be excluded. Moreover, records of H-values have to be stored and analysed in the case of possible pregnancy. (2) A question arises in connection with the special limit 5 mSv: What is the whole time of the treatment? Is it possible to understand it, similarly as in the case of iodine therapy, as 5 mSv per year or is it necessary to take into account really the whole, often very long, time of the treatment? (3) Monitoring of the staff maintaining the hyperbaric chamber and ambulance drivers seems to be unnecessary. Under normal condition, the staff is outside the chamber and its contact with a patient is minimal. In unusual situation, the instructed nurse from the Department of Nuclear Medicine equipped by STEPHEN 6000 will estimate dose equivalent and contact responsible medical

Human ECG Changes During Prolonged Hyperbaric Exposures Breathing N2-O2 Mixtures

National Research Council Canada - National Science Library

Wilson, James M; Kligfield, Paul D; Adams, George M; Harvey, Claude; Schaefer, Karl E

1976-01-01

In an effort to determine whether hyperbaric exposures while breathing N2-O2 mixtures have an effect on cardiac depolarization and repolarization, electrocardiograms of 10 divers participating in four...

In-vitro performance of the Enlite Sensor in various glucose concentrations during hypobaric and hyperbaric conditions.

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Adolfsson, Peter; Ornhagen, Hans; Eriksson, Bengt M; Gautham, Raghavendhar; Jendle, Johan

2012-11-01

There is a need for reliable methods of glucose measurement in different environmental conditions. The objective of this in vitro study was to evaluate the performance of the Enlite® Sensor when connected to either the iPro™ Continuous Glucose Monitor recording device or the Guardian® REAL-Time transmitting device, in hypobaric and hyperbaric conditions. Sixteen sensors connected to eight iPro devices and eight Guardian REAL-Time devices were immersed in three beakers containing separate glucose concentrations: 52, 88, and 207 mg/dl (2.9, 4.9, and 11.3 mmol/liter). Two different pressure tests were conducted: a hypobaric test, corresponding to maximum 18000 ft/5500 m height, and a hyperbaric test, corresponding to maximum 100 ft/30 m depth. The linearity of the sensor signals in the different conditions was evaluated. The sensors worked continuously, and the sensor signals were collected without interruption at all pressures tested. When comparing the input signals for glucose (ISIGs) and the different glucose concentrations during altered pressure, linearity (R(2)) of 0.98 was found. During the hypobaric test, significant differences (p hyperbaric test, no differences were found. The Enlite Sensors connected to either the iPro or the Guardian REAL-Time device provided values continuously. In hyperbaric conditions, no significant differences were seen during changes in ambient pressure; however, during hypobaric conditions, the ISIG was significantly different in the low and high glucose concentrations. © 2012 Diabetes Technology Society.

Hyperbaric oxygen therapy attenuates central sensitization induced by a thermal injury in humans

DEFF Research Database (Denmark)

Rasmussen, V M; Borgen, A E; Jansen, E C

2015-01-01

BACKGROUND: Hyperbaric oxygen (HBO2 ) treatment has in animal experiments demonstrated antinociceptive effects. It was hypothesized that these effects would attenuate secondary hyperalgesia areas (SHAs), an expression of central sensitization, after a first-degree thermal injury in humans. METHODS...... was demonstrated. However, in the nine volunteers starting with the control session, a statistical significant attenuation of SHAs was demonstrated in the HBO2 session (P = 0.004). CONCLUSIONS: The results indicate that HBO2 therapy in humans attenuates central sensitization induced by a thermal skin injury......, compared with control. These new and original findings in humans corroborate animal experimental data. The thermal injury model may give impetus to future human neurophysiological studies exploring the central effects of hyperbaric oxygen treatment....

Hyperbaric oxygen sensitizes anoxic Pseudomonas aeruginosa biofilm to ciprofloxacin

DEFF Research Database (Denmark)

Kolpen, Mette; Lerche, Christian J; Kragh, Kasper Nørskov

2017-01-01

fibrosis (CF) lung. Application of HBOT resulted in enhanced bactericidal activity of ciprofloxacin at clinically relevant durations and was accompanied by indications of restored aerobic respiration, involvement of endogenous lethal oxidative stress and increased bacterial growth. The findings highlight...... that oxygenation by HBOT improves the bactericidal activity of ciprofloxacin on P. aeruginosa biofilm and suggest that bacterial biofilms is sensitized to antibiotics by supplying hyperbaric O2....

Hyperbaric oxygen therapy may overcome nitric oxide blockage during cyanide intoxication

DEFF Research Database (Denmark)

Polzik, Peter; Hansen, Marco Bo; Olsen, Niels Vidiendal

2017-01-01

PURPOSE: To determine the effects of a blockade of nitric oxide (NO) synthesis on hyperbaric oxygen (HBO₂) therapy during cyanide (CN) intoxication. METHODS: 39 anesthetized female Sprague-Dawley rats were exposed to CN intoxication (5.4 mg/kg intra-arterially) with or without previous nitric oxide...

Long-term effect of hyperbaric oxygenation treatment on chronic distressing tinnitus

NARCIS (Netherlands)

Tan, J.; Tange, R. A.; Dreschler, W. A.; vd Kleij, A.; Tromp, E. C.

1999-01-01

Tinnitus is still a phenomenon with an unknown pathophysiology with few therapeutic measures. During the last two decades, hyperbaric oxygenation therapy (HBO) has been used in the treatment of sudden deafness and chronic distressing tinnitus. In this study, we prescribed HBO to 20 patients who had

A pleural vacuum relief device for pleural drain unit use in the hyperbaric environment.

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Gelsomino, Marco; Tsouras, Theo; Millar, Ian; Fock, Andrew

2017-09-01

When a standard water-seal pleural drain unit (PDU) is used under hyperbaric conditions there are scenarios where excessive negative intrapleural pressure (IPP) and/or fluid reflux can be induced, risking significant morbidity. We developed and tested a pleural vacuum relief (PVR) device which automatically manages these risks, whilst allowing more rapid hyperbaric pressure change rates. The custom-made PVR device consists of a one-way pressure relief valve connected in line with a sterile micro filter selected for its specific flow capacity. The PVR device is designed for connection to the patient side sampling port of a PDU system, allowing inflow of ambient air whenever negative pressure is present, creating a small, controlled air leak which prevents excessive negative pressure. The hyperbaric performance of a Pleur-Evac A-6000 intercostal drain was assessed with and without this added device by measuring simulated IPP with an electronic pressure monitor connected at the patient end of the PDU. IPP readings were taken at 10, 15, 20 and 30 cmH₂O of suction (set on the drain unit) at compression rates of 10, 30, 60, 80, 90 and 180 kPa·min⁻¹ to a pressure of 280 kPa. At any compression rate of > 10 kPa·min⁻¹, the negative IPP generated by the Pleur-Evac A-6000 alone was excessive and resulted in back flow through the PDU water seal. By adding the PVR device, the generated negative IPP remains within a clinically acceptable range, allowing compression rates of at least 30 kPa·min⁻¹ with suction settings up to -20 cmH₂O during all phases of hyperbaric treatment. The PDU PVR device we have developed works well, minimising attendant workload and automatically avoiding the excessive negative IPPs that can otherwise occur. This device should only be used with suction.

Effect of hyperbaric oxygen therapy on SAS and SDS in children with ischemic encephalopathy

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Pei-Yun Li

2017-08-01

Full Text Available Objective: To study and analyze the effect of early psychological intervention on the scores of SAS and SDS in children with hypoxic-ischemic encephalopathy undergoing hyperbaric oxygen therapy. Methods: A total of 64 children with hypoxic - ischemic encephalopathy enrolled in our hospital from July 2015 to July 2016 and their parents were selected as study subjects. The patients were treated with hyperbaric oxygen therapy, while their parents were given early psychological intervention. By the way of increasing parents’ awareness of the disease, helping parents build confidence in their children’s treatment and encouraging them to participate in daily training for their children to relieve their anxiety and depression. The parents' knowledge of the disease before and during treatment, the treatment of hyperbaric oxygen therapy and the change of SAS and SDS were observed. Results: After effective intervention, the scores of SAS and SDS of 64 patients’ parents were significantly lower than those before treatment. After 1 courses of intervention, the score of SAS was (43.36 ± 1.27 points, and the score of SDS was (45.22 ± 8.13 points. After 2 courses of intervention, the score of SAS was (41.07 ± 1.21 and the score of SDS was (42.35 ± 7.44 points, and parents' awareness of hypoxic-ischemic encephalopathy was significantly increased, and the differences between the two groups were statistically significant. Conclusion: Early psychological intervention on parents of children with hypoxic-ischemic encephalopathy can effectively improve the awareness of parents on the disease, so as to improve their acceptance of hyperbaric oxygen therapy; significantly reduce the parents’ SAS, SDS score. It is beneficial to build a good doctor-patient and nurse-patient relationship, improve the treatment effect and shorten the treatment time.

Hyperbaric oxygen therapy. Promoting healing in difficult cases

International Nuclear Information System (INIS)

Cohn, G.H.

1986-01-01

Inhalation of pressurized 100% oxygen is a helpful adjunctive treatment for certain patients, because the increased oxygen carried by the blood to the tissue enhances new growth of microcirculation and, thus, healing. Patients with tissue breakdown after radiation therapy, refractory osteomyelitis, gas gangrene, soft-tissue infection with necrosis from mixed aerobic and anaerobic organisms, crush injuries resulting in acute ischemia, and compromised skin grafts or non-healing wounds are likely to benefit from hyperbaric oxygen therapy

Hyperbaric Oxygen Therapy as an Adjuvant Therapy for Comprehensive Treatment of Fournier's Gangrene.

Science.gov (United States)

Li, Chao; Zhou, Xu; Liu, Long-Fei; Qi, Fan; Chen, Jin-Bo; Zu, Xiong-Bing

2015-01-01

To compare simple conventional treatment with the addition of hyperbaric oxygen therapy (HBOT) to conventional therapies in the treatment of Fournier's gangrene (FG). A retrospective study of clinical data was performed by reviewing 28 cases of FG from January 2004 to December 2013 at Xiangya Hospital, Central South University. Among them, 12 patients were treated with the conventional therapy (non-HBOT group) and the other 16 cases were combined with hyperbaric oxygen therapy besides conventional therapy (HBOT group). All patients were followed up for 2 months to assess the therapeutic effect. The analyzed data included age, Fournier gangrene severity index (FGSI) score, number of surgical debridement, indwelling drainage tube time, length of stay (LOS), effective time, and curative time. The mortality rate was lower in the HBOT group at 12.5% (2/16) compared to the non-HBOT group, which was 33.3% (4/12). The difference in the number of surgical debridement, indwelling drainage tube time, and curative time between were significantly lower in the HBOT group compared to the non-HBOT group. Our preliminary research suggests that the effect of combining hyperbaric oxygen therapy with conventional therapy offers considerable advantage in the management of Fournier's gangrene. Multicenter studies with a larger sample size are required to confirm these observations. © 2015 S. Karger AG, Basel.

Decompression sickness rates for chamber personnel: case series from one facility.

Science.gov (United States)

Brandt, Megan S; Morrison, Thomas O; Butler, William P

2009-06-01

During 2004, a case series of decompression sickness (DCS) meeting the definition of epidemic DCS was observed in the Shaw AFB Physiological Training Program. There were 10 cases of chamber-induced altitude DCS observed. Internal and external investigations focused on time, place, person, and environment. No temporal trend was observed. Chamber, masks, regulators, crew positions, and oxygen sources revealed no defects. Among the cases, mean age was 27 yr. Peak altitude in four cases was 35,000 ft and in the other six cases was 25,000 ft. Six had joint pain, one skin symptoms, and three neurological findings. Four were treated with 100% ground-level oxygen and six with hyperbaric oxygen. Four were students and six were inside observers (IO). Four were women and six men. In the IO, where four of the six were women, no gender effect was seen. Examining the IO monthly exposure load (exposures per month) against DCS suggested a dose-response relationship. This relationship held true when 4 yr of Shaw AFB IO data was studied. Indeed, Poisson regression analysis demonstrated a statistically significant 2.1-fold rise in DCS risk with each monthly exposure. Consequently, the number of exposures per month may need to be considered when devising IO schedules.

Hyperbaric oxygen upregulates cochlear constitutive nitric oxide synthase

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Kao Ming-Ching

2011-02-01

Full Text Available Abstract Background Hyperbaric oxygen therapy (HBOT is a known adjuvant for treating ischemia-related inner ear diseases. Controversies still exist in the role of HBOT in cochlear diseases. Few studies to date have investigated the cellular changes that occur in inner ears after HBOT. Nitric oxide, which is synthesized by nitric oxide synthase (NOS, is an important signaling molecule in cochlear physiology and pathology. Here we investigated the effects of hyperbaric oxygen on eardrum morphology, cochlear function and expression of NOS isoforms in cochlear substructures after repetitive HBOT in guinea pigs. Results Minor changes in the eardrum were observed after repetitive HBOT, which did not result in a significant hearing threshold shift by tone burst auditory brainstem responses. A differential effect of HBOT on the expression of NOS isoforms was identified. Upregulation of constitutive NOS (nNOS and eNOS was found in the substructures of the cochlea after HBOT, but inducible NOS was not found in normal or HBOT animals, as shown by immunohistochemistry. There was no obvious DNA fragmentation present in this HBOT animal model. Conclusions The present evidence indicates that the customary HBOT protocol may increase constitutive NOS expression but such upregulation did not cause cell death in the treated cochlea. The cochlear morphology and auditory function are consequently not changed through the protocol.

Microvascular oxygen partial pressure during hyperbaric oxygen in diabetic rat skeletal muscle.

Science.gov (United States)

Yamakoshi, Kohei; Yagishita, Kazuyoshi; Tsuchimochi, Hirotsugu; Inagaki, Tadakatsu; Shirai, Mikiyasu; Poole, David C; Kano, Yutaka

2015-12-15

Hyperbaric oxygen (HBO) is a major therapeutic treatment for ischemic ulcerations that perforate skin and underlying muscle in diabetic patients. These lesions do not heal effectively, in part, because of the hypoxic microvascular O2 partial pressures (PmvO2 ) resulting from diabetes-induced cardiovascular dysfunction, which alters the dynamic balance between O2 delivery (Q̇o2) and utilization (V̇o2) rates. We tested the hypothesis that HBO in diabetic muscle would exacerbate the hyperoxic PmvO2 dynamics due, in part, to a reduction or slowing of the cardiovascular, sympathetic nervous, and respiratory system responses to acute HBO exposure. Adult male Wistar rats were divided randomly into diabetic (DIA: streptozotocin ip) and healthy (control) groups. A small animal hyperbaric chamber was pressurized with oxygen (100% O2) to 3.0 atmospheres absolute (ATA) at 0.2 ATA/min. Phosphorescence quenching techniques were used to measure PmvO2 in tibialis anterior muscle of anesthetized rats during HBO. Lumbar sympathetic nerve activity (LSNA), heart rate (HR), and respiratory rate (RR) were measured electrophysiologically. During the normobaric hyperoxia and HBO, DIA tibialis anterior PmvO2 increased faster (mean response time, CONT 78 ± 8, DIA 55 ± 8 s, P < 0.05) than CONT. Subsequently, PmvO2 remained elevated at similar levels in CONT and DIA muscles until normobaric normoxic recovery where the DIA PmvO2 retained its hyperoxic level longer than CONT. Sympathetic nervous system and cardiac and respiratory responses to HBO were slower in DIA vs. CONT. Specifically the mean response times for RR (CONT: 6 ± 1 s, DIA: 29 ± 4 s, P < 0.05), HR (CONT: 16 ± 1 s, DIA: 45 ± 5 s, P < 0.05), and LSNA (CONT: 140 ± 16 s, DIA: 247 ± 34 s, P < 0.05) were greater following HBO onset in DIA than CONT. HBO treatment increases tibialis anterior muscle PmvO2 more rapidly and for a longer duration in DIA than CONT, but not to a greater level. Whereas respiratory, cardiovascular

Hyperbaric oxygen for the treatment of diabetic foot ulcers: a systematic review

NARCIS (Netherlands)

Stoekenbroek, R. M.; Santema, T. B.; Legemate, D. A.; Ubbink, D. T.; van den Brink, A.; Koelemay, M. J. W.

2014-01-01

A systematic review of randomized clinical trials (RCTs) to assess the additional value of hyperbaric oxygen therapy (HBOT) in promoting the healing of diabetic foot ulcers and preventing amputations was performed. MEDLINE, Embase, and the Cochrane Library were searched to identify RCTs in patients

[Hypobaric 0.15% bupivacaine versus hyperbaric 0.5% bupivacaine for posterior (dorsal) spinal block in outpatient anorectal surgery.].

Science.gov (United States)

Imbelloni, Luiz Eduardo; Vieira, Eneida Maria; Gouveia, M A; Netinho, João Gomes; Cordeiro, José Antonio

2006-12-01

The aim of this study was to study low dose hypobaric 0.15% bupivacaine and hyperbaric 0.5% bupivacaine in outpatient anorectal surgical procedures. Two groups of 50 patients, physical status ASA I and II, undergoing anorectal surgical procedures in a jackknife position, received 6 mg of hypobaric 0.15% bupivacaine in the surgical position (Group 1) or 6 mg of hyperbaric 0.5% bupivacaine in the sitting position for 5 minutes, after which they were placed in a jackknife position (Group 2). Sensitive and motor blockade, time of first urination, ambulation, complications, and the need for analgesics were evaluated. Patients were followed until the third postoperative day and questioned whether they experienced post-puncture headache or temporary neurological symptoms, and until the 30th day and questioned about permanent neurological complications. The test t Student, Mood's median, and Fisher Exact test were used for statistical analysis, and a p hyperbaric or hypobaric, can be safely done.

Hyperbaric oxygen therapy and mechanical resistence of the colonics anastomosis in rats with peritonitis Oxigenoterapia hiperbárica e resistência mecânica das anastomoses cólicas em ratos com peritonite

Directory of Open Access Journals (Sweden)

Antonio Angelo Rocha

2010-08-01

Full Text Available PURPOSE: To analyze the effects of hyperbaric oxygen therapy (HBO on the mechanical resistance of anastomosis performed in rats' distal colon presenting peritonitis induced by ligature and cecal punction using the Total Energy Rupture biomechanical test (ETR. METHODS: It was used 45 rats divided into three groups of 15 animals each. In Control Group (CG, it was performed anastomosis in distal colon without peritonitis. In Peritonitis Group (PG, it was performed anastomosis six hours after the induction of peritonitis by ligature and cecal punction. In Hyperbaric Chamber Group (HCG, it was performed six hours after the induction of peritonitis by ligature and cecal punction. The animals on CG and PG were kept at place air while the animals on HCG were placed on an experimental hyperbaric chamber in order to inhale oxygen at 100%, two absolute atmospheres, for 120 minutes, for four consecutive days. Euthanasia took place on the fifth day of the experiment. All the animals underwent to Total Energy Rupture Biomechanical Resistance test (ETR. Total Energy Rupture was defined as the necessary internal energy stored up to promote the colon rupture after an external traction force imposition. RESULTS: The Peritonitis Group presents smaller average ETR than Control Group. There was no statistical difference between Peritonitis Group and Hyberbaric Chamber Group. CONCLUSION: Hyperbaric oxygen therapy did not alter the mechanical resistance of anastomosis performed in distal colon of rats under the presence of peritonitis induced by ligature and cecal puncture.OBJETIVO: Analisar o efeito da oxigenoterapia hiperbárica (HBO sobre a resistência mecânica de anastomoses realizadas em cólon distal de ratos na presença de peritonite induzida por ligadura e punção cecal utilizando o teste biomecânico de Energia Total de Ruptura (ETR. MÉTODOS: Foram utilizados 45 ratos distribuídos em três grupos de 15 animais. No Grupo Controle (GC, realizou

The neuroprotective effect of hyperbaric oxygen treatment on laser-induced retinal damage in rats

Science.gov (United States)

Vishnevskia-Dai, Victoria; Belokopytov, Mark; Dubinsky, Galina; Nachum, Gal; Avni, Isaac; Belkin, Michael; Rosner, Mordechai

2005-04-01

Retinal damage induced by mechanical trauma, ischemia or laser photocoagulation increases considerably by secondary degeneration processes. The spread of damage may be ameliorated by neuroprotection that is aimed at reducing the extent of the secondary degeneration and promote healing processes. Hyperbaric oxygen (HBO) treatment consists of inspiration of oxygen at higher than one absolute atmospheric pressure. Improved neural function was observed in patients with acute brain trauma or ischemia treated with HBO. This study was designed to evaluate the neuroprotective effect of hyperbaric oxygen (HBO) on laser induced retinal damage in a rat model. Standard argon laser lesions were created in 25 pigmented rats divided into three groups: Ten rats were treated immediately after the irradiation with HBO three times during the first 24 hr followed by 12 consecutive daily treatments. Five rats received a shorter treatment regimen of 10 consecutive HBO treatments. The control group (10 rats) underwent the laser damage with no additional treatment. The retinal lesions were evaluated 20 days after the injury. All outcome measures were improved by the longer HBO treatment (Ptreatment was less effective, showing an increase only in nuclei density at the central area of lesion (Pretinal damage in a rat model. In the range of HBO exposures studied, longer exposure provides more neuroprotection. These results encourage further evaluation of the potential therapeutic use of hyperbaric oxygen in diseases and injuries of the retina.

The role and effectiveness of adjunctive hyperbaric oxygen therapy in the management of musculoskeletal disorders.

Directory of Open Access Journals (Sweden)

Wang J

2002-07-01

Full Text Available The management of musculoskeletal disorders is an increasing challenge to clinicians. Successful treatment relies on a wide range of multidisciplinary interventions. Adjunctive hyperbaric oxygen (HBO therapy has been used as an orthopaedic treatment for several decades. Positive outcomes have been reported by many authors for orthopaedic infections, wound healing, delayed union and non-union of fractures, acute traumatic ischemia of the extremities, compromised grafts, and burn injuries. Severe side effects have also been reported with this therapy. To aid in the use of HBO therapy in orthopaedics, we reviewed 43 papers published in the past four decades and summarised the mechanisms, effectiveness, indications and contraindications, side effects, and cost impact of adjunctive hyperbaric oxygen therapy in the management of difficult musculoskeletal disorders. Adjunctive HBO therapy is an effective treatment modality for the management of some severe and refractory musculoskeletal problems. If appropriate candidates are carefully identified, hyperbaric oxygen is a limb- and sometimes life-saving therapy. HBO therapy significantly reduces the length of the patient′s hospital stay, amputation rate, and wound care expenses. Thus, it is a cost-effective modality. A clinician must understand the side effects and risks of HBO treatment. Close monitoring throughout the treatment is warranted to minimise the risk to the patients.

Cerebral arterial gas embolism from attempted mechanical thrombectomy: recovery following hyperbaric oxygen therapy.

Science.gov (United States)

Segan, Louise; Permezel, Fiona; Ch'ng, Wei; Millar, Ian; Brooks, Mark; Lee-Archer, Matt; Cloud, Geoffrey

2018-04-01

Cerebral arterial gas embolism is a recognised complication of endovascular intervention with an estimated incidence of 0.08%. Its diagnosis is predominantly clinical, supported by neuroimaging. The treatment relies on alleviating mechanical obstruction and reversing the proinflammatory processes that contribute to tissue ischaemia. Hyperbaric oxygen therapy is an effective treatment and has multiple mechanisms to reverse the pathological processes involved in cerebral arterial gas embolism. Symptomatic cerebral arterial gas embolism is a rare complication of endovascular intervention for acute ischaemic stroke. Although there are no previous descriptions of its successful treatment with hyperbaric oxygen therapy following mechanical thrombectomy, this is likely to become more common as mechanical thrombectomy is increasingly used worldwide to treat acute ischaemic stroke. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Effect of rehabilitation training combined with hyperbaric oxygen therapy on the nerve cytokine secretion and oxidative stress in rehabilitation period of patients with cerebral infarction

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Ling Kong

2017-11-01

Full Text Available Objective: To discuss the influence of rehabilitation training combined with hyperbaric oxygen therapy on the nerve cytokine secretion and oxidative stress in rehabilitation period of patients with cerebral infarction. Methods: A total of 110 patients with cerebral infarction who received rehabilitation therapy in the hospital between January 2015 and May 2017 were divided into routine group (n=55 and hyperbaric oxygen group (n=55 according to random number table. Routine group received regular rehabilitation training, and hyperbaric oxygen group underwent rehabilitation training combined with hyperbaric oxygen therapy. The differences in the serum contents of nerve factors, neurotransmitters and oxidative stress indexes were compared between the two groups at immediately after admission (T0 and after 14 d of treatment (T1. Results: At T0, there was no statistically significant difference in the serum contents of nerve factors, neurotransmitters and oxidative stress indexes between the two groups. At T1, serum nerve factors MBP and NSE contents of hyperbaric oxygen group were lower than those of routine group while NGF content was higher than that of routine group; serum neurotransmitter Glu content was lower than that of routine group while GABA content was higher than that of routine group; serum oxidative stress indexes ROS and LHP contents were lower than those of routine group while CAT and SOD contents were higher than those of routine group. Conclusion: Rehabilitation training combined with hyperbaric oxygen therapy can effectively optimize the nerve function and inhibit the systemic oxidative stress response in rehabilitation period of patients with cerebral infarction.

Reinforcement of spinal anesthesia by epidural injection of saline: a comparison of hyperbaric and isobaric tetracaine.

Science.gov (United States)

Yamazaki, Y; Mimura, M; Hazama, K; Namiki, A

2000-04-25

An epidural injection of saline was reported to extend spinal anesthesia because of a volume effect. The aim of this study was to evaluate the influence of the baricity of spinal local anesthetics upon the extension of spinal anesthesia by epidural injection of saline. Forty patients undergoing elective lower-limb surgery were randomly allocated to four groups of 10 patients each. Group A received no epidural injection after the spinal administration of hyperbaric tetracaine (dissolved in 10% glucose). Group B received an epidural injection of 8 ml of physiological saline 20 min after spinal hyperbaric tetracaine. Group C received no epidural injection after spinal isobaric tetracaine (dissolved in physiological saline). Group D received an epidural injection of 8 ml of saline 20 min after spinal isobaric tetracaine. The level of analgesia was examined by the pinprick method at 5-min intervals. The levels of analgesia 20 min after spinal anesthesia were significantly higher in hyperbaric groups than in isobaric groups [T5 (T2-L2) vs. T7 (T3-12)]. After epidural injection of saline, the levels of analgesia in groups B and D were significantly higher than in groups A and C. The segmental increases after epidural saline injection were 2 (0-3) in group B and 2 (1-7) in group D. Sensation in the sacral area remained 20 min after spinal block in one patient in group D; however, it disappeared after epidural saline injection. In this study, 8 ml of epidural saline extended spinal analgesia. However, there was no difference between the augmenting effect in isobaric and hyperbaric spinal anesthesia. We conclude that the reinforcement of spinal anesthesia by epidural injection of saline is not affected by the baricity of the spinal anesthetic solution used.

Recruiting, Selection, Training and Military Operations of Female Aircrew (Le Recrutement, la Selection, l’Entrainement et les Operations Militaires du Personnel Navigant Feminin)

Science.gov (United States)

1990-08-01

1 soit 1,36 %. 11 sagit d’un barotraumatisue manifest6 lore de l’Apreuve au caisson hypobare . (N.B. :Lee candidates ont deux chances pour cette...Aerospace Medicine Brooks AFB, TX 78235-5301 Summary Records at the United States Air Force School of Aerospace Medicine, Division of Hyperbaric Medicine...Records of all DCS cases treated in USAF hyperbaric chambers are maintained at the USAF School of Aerospace Medicine (USAFSAM), Hyperbaric Medicine

Application effect of hyperbaric oxygen in the patients with optic atrophy and influence for the hemodynamic parameters

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Kun Zhang

2015-01-01

Full Text Available AIM: To observe the application effect of hyperbaric oxygen in the patients with optic atrophy and influence degree for the hemodynamic parameters.METHODS: Fifty patients with optic atrophy in our hospital from January 2012 to January 2014 were objected, they were randomly divided into control group(conventional optic atrophy treatment groupand observation group(conventional treatment and hyperbaric oxygen treatment group, each group was 25 cases. Statistical analysis of two group before and after treatment eyesight, vision acuity, visual field defect and ophthalmic artery, central retinal artery blood flow parameters were undergone.RESULTS: The sight, visual field sensitivity and field vision defect of observation group were all better than those of control group at first, second and third course after the treatment, arteriae ophthalmica and arteriae centralis retinae EDV and PSV were all higher than those of control group, PI and RI were all lower than those of control group were all significant differences(PCONCLUSION: The application effect of hyperbaric oxygen in the patients with optic atrophy is better, and the influence of treatment method for the ocular hemodynamic parameters are more active.

Does hyperbaric oxygen have a cancer-causing or -promoting effect? A review of the pertinent literature.

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Feldmeier, J J; Heimbach, R D; Davolt, D A; Brakora, M J; Sheffield, P J; Porter, A T

1994-12-01

We reviewed all known published reports or studies related to a possible cancer-causing or growth-enhancing effect by hyperbaric oxygen. Published articles were retrieved using Medline searches for the period 1960-1993. Additional references were obtained from bibliographies included in those articles discovered in the computer search. Also, hyperbaric medicine text books and the published proceedings of international hyperbaric conferences were visually searched. Studies and reports discovered in this fashion and related to the topic were included in the review. Twenty-four references were found: 12 were clinical reports, 11 were animal studies, and 1 reported both an animal study and a clinical report. Three clinical reports suggested a positive cancer growth enhancement, whereas 10 clinical reports showed no cancer growth enhancement. Two animal studies suggested a positive cancer-enhancing effect, and 10 animal studies showed no such effect. (The report that included both animals and humans is counted in both groups). The vast majority of published reports show no cancer growth enhancement by HBO exposure. Those studies that do show growth enhancement are refuted by larger subsequent studies, are mixed studies, or are highly anecdotal. A review of published information fails to support a cancer-causing or growth-enhancing effect by HBO.

Hyperbaric oxygen therapy for the treatment of radiation-induced macular ischemia

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Shamim A Haji

2010-05-01

Full Text Available Shamim A Haji1,2, Ronald EP Frenkel1,2,31Eye Research Foundation, Stuart, FL, USA; 2East Florida Eye Institute, Stuart, FL, USA; 3Bascom Palmer Eye Institute, Miami, FL, USAPurpose: To report a case of radiation-induced macular ischemia where vision and macular perfusion improved after hyperbaric oxygen (HBO therapy.Methods: A 62-year-old male patient developed radiation-induced macular ischemia after he was treated with radiation for brain glioma. The patient presented with best spectacle-corrected visual acuity (BSCVA acuity of 20/400 in his right eye. Optical coherence tomography (OCT showed central macular thickness of 468 μm. The patient received focal laser, intravitreal triamcinolone, and HBO therapy.Results: The patient’s vision improved from 20/400 to 20/100 after focal laser and intravitreal triamcinolone. His central macular thickness improved from 468 μm to 132 μm. After receiving HBO therapy, his VA improved to 20/50 and fluorescein angiography showed improvement in macular perfusion.Conclusion: HBO therapy improves macular perfusion in patients with radiation-induced macular ischemia.Keywords: macular ischemia, visual acuity, hyperbaric oxygen therapy, macular perfusion

[Value of the isometric exercise test in objectively evaluating the effectiveness of hyperbaric oxygenation in ischemic heart disease].

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Efuni, S N; Kudriashov, V E; Rodionov, V V; Beletskiĭ, Iu V; Telegin, Iu N

1984-05-01

The isometric test was conducted prior to and after a hyperbaric oxygenation (HBO) session in 31 coronary heart disease (CHD) patients. The results were compared with the findings provided by the examination of 138 coronary patients and 23 normal subjects receiving no HBO treatment. It was shown that the isometric test makes it possible to objectively assess the HBO effect in CHD patients. The results of the test reflect reduction in the severity of angina pectoris or cardiac failure following hyperbarotherpy. The results obtained justify the recommendation of the isometric test for the individual evaluation of the hyperbaric treatment in CHD.

Irradiation with misonidazole and hyperbaric oxygen: final report on a randomized trial in advanced head and neck cancer

International Nuclear Information System (INIS)

Sealy, R.; Cridland, S.; Barry, L.; Norris, R.

1986-01-01

One hundred and thirty patients with locally advanced squamous carcinoma of the head and neck were treated in a prospective randomized trial to compare conventional irradiation (63.00 Gy in 30 fractions) with a combination sensitizer regimen of misonidazole and hyperbaric oxygen. The drug (2.0 gm/m2) was given with each of six fractions of 6.0 Gy in hyperbaric oxygen at 3 ATA. The results support a previous study and favor the combination at 1 year at better than the 10% level. This regimen could be useful for bulky primary or nodal disease

Combined use of hyperbaric and hypobaric ropivacaine significantly improves hemodynamic characteristics in spinal anesthesia for caesarean section: a prospective, double-blind, randomized, controlled study.

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Quan, ZheFeng; Tian, Ming; Chi, Ping; Li, Xin; He, HaiLi; Luo, Chao

2015-01-01

To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study. Parturients (n = 136) undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A) or hyperbaric ropivacaine (Group B). Outcome measures were: hemodynamic characteristics, maximum height of sensory block, time to achieve T8 sensory blockade level, incidence of complications, Apgar scores at 1 and 5 min, and neonatal blood gas analysis. Group A had a lower level of sensory blockade (T6 [T6-T7]) and longer time to achieve T8 sensory blockade level (8 ± 1.3 min) than did patients in Group B (T3 [T2-T4] and 5 ± 1.0 min, respectively; P hyperbaric (4 mg) and hypobaric (6 mg) ropivacaine significantly decreased the incidences of hypotension and complications in spinal anesthesia for caesarean section by extending induction time and decreasing the level of sensory blockade. Chinese Clinical Trial Register ChiCTR-TRC-13004622.

Influence of lateral decubitus positioning after combined use of hyperbaric and hypobaric ropivacaine on hemodynamic characteristics in spinal anesthesia for caesarean section

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Quan, Zhe-Feng; He, Hai-Li; Tian, Ming; Chi, Ping; Li, Xin

2014-01-01

Purpose: Positioning of the patient during and after surgery can have significant implications on recovery. Therefore, the purpose of the present study was to determine the influence of placing patients in a lateral decubitus position for 15 min after combined use of hyperbaric and hypobaric ropivacaine and assess hemodynamic characteristics during spinal anesthesia for caesarean section. Methods: One hundred-forty patients undergoing elective cesarean delivery with combined use of hyperbaric...

Hyperbaric oxygen therapy of spinal cord injury

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Nitesh P Patel

2017-01-01

Full Text Available Spinal cord injury (SCI is a complex disease process that involves both primary and secondary mechanisms of injury and can leave patients with devastating functional impairment as well as psychological debilitation. While no curative treatment is available for spinal cord injury, current therapeutic approaches focus on reducing the secondary injury that follows SCI. Hyperbaric oxygen (HBO therapy has shown promising neuroprotective effects in several experimental studies, but the limited number of clinical reports have shown mixed findings. This review will provide an overview of the potential mechanisms by which HBO therapy may exert neuroprotection, provide a summary of the clinical application of HBO therapy in patients with SCI, and discuss avenues for future studies.

Comparison of intrathecal clonidine and magnesium sulphate used as an adjuvant with hyperbaric bupivacaine in lower abdominal surgery

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Mamta Khandelwal

2017-01-01

Full Text Available Background and Aims: Use of various adjuvants to spinal anaesthesia is a well-known modality to provide intra- and post-operative analgesia. This study was designed to evaluate and compare the analgesic efficacy of clonidine and magnesium when used as an additive to intrathecal 0.5% hyperbaric bupivacaine. Methods: Ninety patients of the American Society of Anesthesiologists' physical status grade I or II, scheduled for lower abdominal surgery under spinal anaesthesia, were randomly allocated into three groups. Group B received 3 mL of 0.5% hyperbaric bupivacaine with 1 mL of normal saline, Group C received 3 mL of 0.5% hyperbaric bupivacaine with 1 mL (30 μg of clonidine and Group M received 3 mL of 0.5% hyperbaric bupivacaine with 1 mL (50 mg magnesium sulphate. The primary outcome variable was duration of analgesia and secondary outcome variables included onset and duration of sensory and motor block, sedation level and adverse effects. Data were analysed with ANOVA, Kruskal–Wallis and Chi-square tests. Results: The time to first rescue analgesia was significantly (P < 0.01 longer in the Group C (330.7 ± 47.7 min than both Groups. Group M (246.3 ± 55.9 min showed significantly prolonged analgesia than Group B (134.4 ± 17.9 min. Group C and Group M showed significantly prolonged duration of both sensory and motor block compared to Group B. Conclusion: Intrathecal clonidine added to bupivacaine prolongs the duration of post-operative analgesia, and hastens the onset and prolongs the duration of sensory and motor block compared to magnesium or controls.

Hyperbaric oxygen therapy in the treatment of radio-induced lesions in normal tissues: a literature review

International Nuclear Information System (INIS)

Pasquier, David; Hoelscher, Tobias; Schmutz, Jorg; Dische, Stanley; Mathieu, Daniel; Baumann, Michael; Lartigau, Eric

2004-01-01

Late complications are one of the major factors limiting radiotherapy treatment, and their treatment is not codified. Hyperbaric oxygen (HBO) has been used in combination with radiotherapy for over half a century, either to maximise its effectiveness or in an attempt to treat late complications. In this latter case, retrospective trials and case reports are prevailing in literature. This prompted European Society for Therapeutic Radiotherapy and Oncology and European Committee for Hyperbaric Medicine to organise a consensus conference in October 2001, dealing with the HBO indications on radiotherapy for the treatment and prevention of late complications. This updated literature review is part of the documents the jury based its opinion on. A systematic search was done on literature from 1960 to 2004, by only taking into account the articles that appeared in peer review journals. Hyperbaric oxygen treatment involving complications to the head and neck, pelvis and nervous system, and the prevention of complications after surgery in irradiated tissues have been studied. Despite the small number of controlled trials, it may be indicated for the treatment of mandibular osteoradionecrosis in combination with surgery, haemorrhagic cystitis resistant to conventional treatments and the prevention of osteoradionecrosis after dental extraction, whose level of evidence seems to be the most significant though randomised trials are still necessary. The other treatment methods are also outlined for each location

The treatment of tumors by the induction of anemia and irradiation in hyperbaric oxygen

International Nuclear Information System (INIS)

Sealy, R.; Jacobs, P.; Wood, L.; Levin, W.; Barry, L.; Boniaszczuk, J.; Blekkenhorst, G.

1989-01-01

Because increased effects have been achieved when murine tumors are irradiated after a period of hypoxia and because of anecdotal clinical experiences of an improved result after irradiation of previously anemic patients in hyperbaric oxygen, the relationship between irradiation and increased survival was investigated in seventy-two patients with advanced head and neck or cervical cancer. Anemia was achieved by means of a two-stage isovolemic venesection maintained for seventy-two hours, hemoglobin was returned to a normal level, and treatment in hyperbaric oxygen was started. Marked tumor shrinkage after the induction of anemia and before radiotherapy was seen and was probably disease, site, and hemoglobin level related. As a result, a possible new approach to cancer therapy is suggested. After completion of therapy, the 1-year disease-free survival for patients with head and neck and cervical cancer was not improved, but the 21-month survival for cervical cancer was improved. Further studies are strongly urged

Advantages and Disadvantages of Hyperbaric Oxygen Treatment in Mice with Obesity Hyperlipidemia and Steatohepatitis

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Koichi Tsuneyama

2011-01-01

Full Text Available The effect of hyperbaric oxygen treatment (HBOT was examined using MSG mice, which are an animal model of obesity, hyperlipidemia, diabetes, and nonalcoholic fatty liver disease. Nineteen MSG male mice were divided into HBOT treated and control groups at 12 weeks of ages. The HBOT group was treated with hyperbaric oxygen from 12 to 14 weeks (first phase and then from 16 to 18 weeks (second phase. Interestingly, the body weight of the HBOT group was significantly lower (P<0.01 than that of the control group. In contrast, the serum lipid level did not show significant changes between the two groups. As for the effects of increasing oxidative stress, the liver histology of the HBOT group showed severer cellular damage and aberrant TNF-α expression. HBOT has the advantage of improving obesity in patients with metabolic syndrome, but the fault of causing organ damage by increasing oxidative stress.

Oxybiotest project: microorganisms under pressure. Hyperbaric oxygen (HBO and simple pressure interaction on selected bacteria

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Zanon Vincenzo

2012-09-01

Full Text Available Abstract Background HyperBaric Oxygen (HBO therapy involves exposure to pure oxygen in a pressurized room, and it is an already well-established treatment for various conditions, including those originated by serious infections. Starting from the observation of an increased number of patients who were accessing our HBO units for diseases supported from concomitant multidrug-resistant microorganisms, as well as considering the evident clinical benefit and laboratory final outcome of those patients at the end of the treatment, aim of our study was to measure, or better define at least, if there was any interaction between a hyperbaric environment and some selected microorganisms and if those positive results were due to the increased oxygen partial pressure (pO2 value or just to the increased pressure, regardless of the fraction of inspired oxygen (FiO2 applied (21÷100%. Design and methods We applied various increased pO2 values in a hyperbaric environment. Our study design was tailored in four steps to answer four specific questions, ordered in a progressive process: OxyBioTest (OBT-1,2,3, and 4. Specifically, we chose to investigate possible changes in the Minimum Inhibitory Concentration (MIC and in the Minimum Bactericidal Concentration (MBC of multi-resistant microorganisms after a single session of hyperbaric therapy. Results OBT-1 and OBT-2 provide a semi-quantitative confirmation of the bacterio-cidal and cytostatic effects of HBO. HBO is cidal only if the total exposure pressure is elevated, and cidal or cytostatic effect are not always dependent on the pO2 applied. OBT-4 has shown the adjuvant effect of HBO and antimicrobial drug against some selected bacteria. Discussion We seem allowed to hypothesize that only in case of a good approach to a lesion, permitting smaller bacterial loads thanks to surgical debridement and/or eventual antibiotic therapy for example, You can observe the clear effectiveness of the HyperBaric Oxygen (HBO

A COMPARISON OF SPINAL ANAESTHESIA WITH LEVOBUPIVACAINE AND HYPERBARIC BUPIVACAINE COMBINED WITH FENTANYL IN CAESAREAN SECTION

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Kurmanadh Kalepalli

2016-10-01

Full Text Available BACKGROUND Recent trends in obstetric anaesthesia show increased popularity of regional anaesthesia among obstetric anaesthetists. General anaesthesia in caesarean section is associated with high morbidity and mortality rate when compared with regional anaesthesia. Regional anaesthesia has its own demerits which are primarily related to excessively high spinal blocks and toxicity of local anaesthetics. Reduction in doses and improvement in technique to avoid high level blocks and increased awareness of toxicity of local anaesthetics have contributed to reduction in complications related to regional anaesthesia. The challenges presented by a parturient requiring anaesthesia or analgesia, or both, make the role of obstetric anaesthesiologist both challenging and rewarding. Spinal anesthesia is a popular technique for caesarean delivery. Hyperbaric Bupivacaine in 8% glucose is often used. Plain or glucose-free, Bupivacaine has been frequently referred to as “Isobaric” in the literature, even after Blomqvist and Nilsson demonstrated its hypobaricity. More recently, several studies have confirmed that plain Bupivacaine is indeed hypobaric in comparison with human CSF. Although hyperbaric local anesthetic solutions have a remarkable record of safety, their use is not totally without risk. To prevent unilateral or saddle blocks, patients should move from the lateral or sitting position rapidly to supine position. Hyperbaric solutions may cause sudden cardiac arrest after spinal anesthesia because of the extension of the sympathetic block. The use of truly isobaric solutions may prove less sensitive to position issues. Hyperbaric solutions may cause hypotension or bradycardia after mobilization. Isobaric solutions are favored with respect to their less sensitivity to postural changes. MATERIALS AND METHODS 60 full term parturients of ASA Grade 1 and 2 posted for elective caesarean section under spinal anaesthesia were divided in to two groups. GROUP

Ropivacaine for unilateral spinal anesthesia; hyperbaric or hypobaric?

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Cantürk, Mehmet; Kılcı, Oya; Ornek, Dilşen; Ozdogan, Levent; Pala, Yasar; Sen, Ozlem; Dikmen, Bayazit

2012-01-01

The aim of this study was to compare the unilaterality of subarachnoid block achieved with hyperbaric and hypobaric ropivacaine. The prospective, randomized trial was conducted in an orthopedics surgical suite. In all, 60 ASA I-III patients scheduled for elective total knee arthroplasty were included in the study. Group Hypo (n=30) received 11.25mg of ropivacaine (7.5mg.mL(-1)) + 2mL of distilled water (density at room temperature was 0.997) and group Hyper (n=30) received 11.25mg of ropivacaine (7.5mg.mL(-1)) + 2mL (5mg.mL(-1)) of dextrose (density at room temperature was 1,015). Patients in the hyperbaric group were positioned with the operated side down and in the 15° Fowler position, versus those in the hypobaric group with the operated side facing up and in the 15° Trendelenburg position. Combined spinal epidural anesthesia was performed midline at the L(3-4) lumbar interspace. Hemodynamic and spinal block parameters, regression time, success of unilateral spinal anesthesia, patient comfort, surgical comfort, surgeon comfort, first analgesic requirement time, and adverse effects were assessed. Time to reach the T10 dermatome level on the operated side was shorter in group Hyper (612.00±163.29s) than in group Hypo (763.63±208.35s) (phyperbaric and hypobaric ropivacaine (11.25mg) provided adequate and dependable anesthesia for total knee replacement surgery, with a high level of patient and surgeon comfort. Hypobaric local anesthetic solutions provide a high level of unilateral anesthesia, with rapid recovery of both sensory and motor block, and therefore may be preferable in outpatient settings. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.

Hyperbaric oxygen therapy ameliorates acute brain injury after porcine intracerebral hemorrhage at high altitude.

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Zhu, Hai-tao; Bian, Chen; Yuan, Ji-chao; Liao, Xiao-jun; Liu, Wei; Zhu, Gang; Feng, Hua; Lin, Jiang-kai

2015-06-15

Intracerebral hemorrhage (ICH) at high altitude is not well understood to date. This study investigates the effects of high altitude on ICH, and examines the acute neuroprotection of hyperbaric oxygen (HBO) therapy against high-altitude ICH. Minipigs were placed in a hypobaric chamber for 72 h before the operation. ICH was induced by an infusion of autologous arterial blood (3 ml) into the right basal ganglia. Animals in the high-altitude ICH group received HBO therapy (2.5 ATA for 60 min) 30 min after ICH. Blood gas, blood glucose and brain tissue oxygen partial pressure (PbtO2) were monitored continuously for animals from all groups, as were microdialysis products including glucose, lactate, pyruvate and glutamate in perihematomal tissue from 3 to 12 h post-ICH. High-altitude ICH animals showed significantly lower PbtO2, higher lactate/pyruvate ratio (LPR) and glutamate levels than low-altitude ICH animals. More severe neurological deficits, brain edema and neuronal damage were also observed in high-altitude ICH. After HBO therapy, PbtO2 was significantly increased and LPR and glutamate levels were significantly decreased. Brain edema, neurological deficits and neuronal damage were also ameliorated. The data suggested a more serious disturbance of tissue oxygenation and cerebral metabolism in the acute stage after ICH at high altitude. Early HBO treatment reduced acute brain injury, perhaps through a mechanism involving the amelioration of the derangement of cerebral oxygenation and metabolism following high-altitude ICH.

Treatment of Fournier's Gangrene with Combination of Vacuum-Assisted Closure Therapy, Hyperbaric Oxygen Therapy, and Protective Colostomy

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Giovanni Zagli

2011-01-01

Full Text Available Fournier's gangrene is a rare process which affects soft tissue in the genital and perirectal area. It can also progress to all different stages of sepsis, and abdominal compartment syndrome can be one of its complications. Two patients in septic shock due to Fournier gangrene were admitted to the Intensive Care Unit of Emergency Department. In both cases, infection started from the scrotum and the necrosis quickly involved genitals, perineal, and inguinal regions. Patients were treated with surgical debridement, protective colostomy, hyperbaric oxygen therapy, and broad-spectrum antibacterial chemotherapy. Vacuum-assisted closure (VAC therapy was applied to the wound with the aim to clean, decontaminate, and avoid abdominal compartmental syndrome development. Both patients survived and were discharged from Intensive Care Unit after hyperbaric oxygen therapy cycles and abdominal closure.

Hyperbaric environment up-regulates CD15s expression on leukocytes, down-regulates CD77 expression on renal cells and up-regulates CD34 expression on pulmonary and cardiac cells in rat

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Danka Đevenica

2016-08-01

Full Text Available Objective(s: The aim of this study was to estimate effects of hyperbaric (HB treatment by determination of CD15s and CD11b leukocyte proinflammatory markers expression.  In addition, this study describes changes in CD77 and CD34 expression on rat endothelial cells in renal, pulmonary and cardiac tissue following exposure to hyperbaric pressure. Materials and Methods:Expression of CD11b and CD15s on leukocytes, as well as CD77 and CD34 expression on endothelial cells in cell suspensions of renal, pulmonary and cardiac tissue in rats after hyperbaric treatment and in control rats were determined by flow cytometry. Results: Hyperbaric treatment significantly increased percentage of leukocytes expressing CD15s+CD11b- (from 1.71±1.11 to 23.42±2.85, P

[New approaches in neurosurgery and hyperbaric medicine--the importance of preventive and industrial medicine].

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Kohshi, K; Munaka, M; Abe, H; Tosaki, T

1999-12-01

Neurosurgical patients have been mainly treated by surgical procedures over the past decades. In addition, hyperbaric oxygen (HBO) therapy in neurosurgery has been used in patients with ischemic cerebrovascular diseases, head trauma, spinal damage, postoperative brain edema and others. However, the main therapeutic methods for neurosurgical diseases have changed dramatically due to developments in radiological techniques, such as radiosurgery and intravascular surgery. With changes in therapeutic methods, HBO therapy may become a very important treatment option for neurosurgical patients. For example, HBO therapy combined with radiotherapy (UOEH regimen) and anticoagulant therapy appear to be very effective in the treatments of malignant brain tumors and ischemic cerebrovascular diseases, respectively. On the other hand, medical examinations under hyper- and hypobaric environments have not yet been fully studied in the central nervous system compared to those in the cardiopulmonary systems. Moreover, the mechanisms of cerebral lesions in decompression sickness and acute mountain sickness remain unclear. Clinical neurologic approaches are very important in these fields. Hence, clinicians and researchers skilled in both neurosurgery and hyperbaric medicine will be required for advanced treatment and preventive and industrial medicine.

Hyperbaric oxygen therapy in periodontal diseases

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Swapna A. Mahale

2013-01-01

Full Text Available Hyperbaric oxygen (HBO 2 has been successfully used in several medical fields. The therapeutic effect is related to elevated partial oxygen pressure in the tissues. The pressure itself enhances oxygen solubility in the tissue fluids. HBO 2 has shown to affect angiogenesis, bone metabolism and bone turnover. Studies have been conducted to analyze the effects of HBO 2 therapy on periodontal disease. HBO 2 increases local oxygen distribution, especially at the base of the periodontal pocket, which inhibits the growth of anaerobic bacteria and allows the ischemic tissues to receive an adequate intake of oxygen sufficient for a rapid recovery of cell metabolism. It is increasingly being accepted as a beneficial adjunct to diverse clinical conditions. Nonhealing ulcers, chronic wounds and refractory osteomyelitis are a few conditions for which HBO therapy (HBOT has been extensively tried out. The dental surgeons have found a good ally in HBOT in managing dental condition.

Hyperbaric Oxygen Therapy and Oxygen Compatibility of Skin and Wound Care Products.

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Bernatchez, Stéphanie F; Tucker, Joseph; Chiffoleau, Gwenael

2017-11-01

Objective: Use test methods to assess the oxygen compatibility of various wound care products. Approach: There are currently no standard test methods specifically for evaluating the oxygen compatibility and safety of materials under hyperbaric oxygen (HBO) conditions. However, tests such as the oxygen index (OI), oxygen exposure (OE), and autogenous ignition temperature (AIT) can provide useful information. Results: The OI test measures the minimum oxygen concentration that will support candle-like burning, and it was used to test 44 materials. All but two exhibited an OI equal to or greater (safer) than a control material commonly used in HBO. The OE test exposes each material to an oxygen-enriched atmosphere (>99.5% oxygen) to monitor temperature and pressure for an extended duration. The results of the OE testing indicated that none of the 44 articles tested with this method self-ignited within the 60°C, 3 atm pressurized oxygen atmosphere. The AIT test exposes materials to a rapid ramp up in temperature in HBO conditions at 3 atm until ignition occurs. Ten wound care materials and seven materials usually avoided in HBO chambers were tested. The AIT ranged from 138°C to 384°C for wound care products and from 146°C to 420°C for the other materials. Innovation: This work provides useful data and recommendations to help develop a new standard approach for evaluating the HBO compatibility of wound care products to ensure safety for patients and clinicians. Conclusion: The development of an additional test to measure the risk of electrostatic discharge of materials in HBO conditions is needed.

Combined use of hyperbaric and hypobaric ropivacaine significantly improves hemodynamic characteristics in spinal anesthesia for caesarean section: a prospective, double-blind, randomized, controlled study.

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ZheFeng Quan

Full Text Available To observe the hemodynamic changes of parturients in the combined use of hyperbaric (4 mg and hypobaric (6 mg ropivacaine during spinal anesthesia for caesarean section in this randomized double-blind study.Parturients (n = 136 undergoing elective cesarean delivery were randomly and equally allocated to receive either combined hyperbaric and hypobaric ropivacaine (Group A or hyperbaric ropivacaine (Group B. Outcome measures were: hemodynamic characteristics, maximum height of sensory block, time to achieve T8 sensory blockade level, incidence of complications, Apgar scores at 1 and 5 min, and neonatal blood gas analysis.Group A had a lower level of sensory blockade (T6 [T6-T7] and longer time to achieve T8 sensory blockade level (8 ± 1.3 min than did patients in Group B (T3 [T2-T4] and 5 ± 1.0 min, respectively; P < 0.001, both. The incidence rates for hypotension, nausea, and vomiting were significantly lower in Group A (13%, 10%, and 3%, respectively than Group B (66%, 31%, and 13%; P < 0.001, P = 0.003, P = 0.028.Combined use of hyperbaric (4 mg and hypobaric (6 mg ropivacaine significantly decreased the incidences of hypotension and complications in spinal anesthesia for caesarean section by extending induction time and decreasing the level of sensory blockade.Chinese Clinical Trial Register ChiCTR-TRC-13004622.

Hyperbaric oxygen preconditioning protects against traumatic brain injury at high altitude.

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Hu, S L; Hu, R; Li, F; Liu, Z; Xia, Y Z; Cui, G Y; Feng, H

2008-01-01

Recent studies have shown that preconditioning with hyperbaric oxygen (HBO) can reduce ischemic and hemorrhagic brain injury. We investigated effects of HBO preconditioning on traumatic brain injury (TBI) at high altitude and examined the role of matrix metalloproteinase-9 (MMP-9) in such protection. Rats were randomly divided into 3 groups: HBO preconditioning group (HBOP; n = 13), high-altitude group (HA; n = 13), and high-altitude sham operation group (HASO; n = 13). All groups were subjected to head trauma by weight-drop device, except for HASO group. HBOP rats received 5 sessions of HBO preconditioning (2.5 ATA, 100% oxygen, 1 h daily) and then were kept in hypobaric chamber at 0.6 ATA (to simulate pressure at 4000m altitude) for 3 days before operation. HA rats received control pretreatment (1 ATA, room air, 1 h daily), then followed the same procedures as HBOP group. HASO rats were subjected to skull opening only without brain injury. Twenty-four hours after TBI, 7 rats from each group were examined for neurological function and brain water content; 6 rats from each group were killed for analysis by H&E staining and immunohistochemistry. Neurological outcome in HBOP group (0.71 +/- 0.49) was better than HA group (1.57 +/- 0.53; p < 0.05). Preconditioning with HBO significantly reduced percentage of brain water content (86.24 +/- 0.52 vs. 84.60 +/- 0.37; p < 0.01). Brain morphology and structure seen by light microscopy was diminished in HA group, while fewer pathological injuries occurred in HBOP group. Compared to HA group, pretreatment with HBO significantly reduced the number of MMP-9-positive cells (92.25 +/- 8.85 vs. 74.42 +/- 6.27; p < 0.01). HBO preconditioning attenuates TBI in rats at high altitude. Decline in MMP-9 expression may contribute to HBO preconditioning-induced protection of brain tissue against TBI.

Economic outcomes in clinical studies assessing hyperbaric oxygen in the treatment of acute and chronic wounds

NARCIS (Netherlands)

Santema, Trientje B.; Stoekenbroek, Robert M.; van Steekelenburg, Koen C.; van Hulst, Rob A.; Koelemay, Mark Jw; Ubbink, Dirk T.

2015-01-01

Introduction: Hyperbaric oxygen treatment (HBOT) is used to treat acute and chronic wounds. This systematic review was conducted to summarise and evaluate existing evidence on the costs associated with HBOT in the treatment of wounds. Methods: We searched multiple electronic databases in March 2015

Effect of Exposure to Hyperoxic, Hypobaric, and Hyperbaric Environments on Concentrations of Selected Aerobic and Anaerobic Fecal Flora of Mice

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Gillmore, James D.; Gordon, Francis B.

1975-01-01

Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration at 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the Klebsiella-Enterobacter flora which normally occurs after weaning. During exposure to hypobaric environments (100% O2, 0.2 atmosphere absolute), significant alterations in concentrations of Escherichia coli, slow lactose fermenters, Klebsiella-Enterobacter, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O2, 7.5 atmospheres absolute), increased concentrations of Klebsiella-Enterobacter, E. coli, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous

Monitoring carbon dioxide in mechanically ventilated patients during hyperbaric treatment

DEFF Research Database (Denmark)

Bjerregård, Asger; Jansen, Erik

2012-01-01

Measurement of the arterial carbon dioxide (P(a)CO(2)) is an established part of the monitoring of mechanically ventilated patients. Other ways to get information about carbon dioxide in the patient are measurement of end-tidal carbon dioxide (P(ET)CO(2)) and transcutaneous carbon dioxide (PTCCO2......). Carbon dioxide in the blood and cerebral tissue has great influence on vasoactivity and thereby blood volume of the brain. We have found no studies on the correlation between P(ET)CO(2) or P(TC)CO(2), and P(a)CO(2) during hyperbaric oxygen therapy (HBOT)....

Hyperbaric bupivacaine 2.5 mg prolongs analgesia compared with plain bupivacaine when added to intrathecal fentanyl 25 microg in advanced labor.

Science.gov (United States)

Teoh, Wendy H L; Sia, Alex T H

2003-09-01

We investigated the effect of sequential administration of intrathecal (IT) hyperbaric bupivacaine (after the initial administration of IT hypobaric fentanyl) on the duration of spinal analgesia. Thirty-seven nulliparous parturients with a cervical dilation >/= 5 cm were randomized to receive either IT fentanyl 25 micro g and plain bupivacaine 2.5 mg (group P; n = 19) or IT fentanyl 25 micro g and hyperbaric (with 8% glucose) bupivacaine 2.5 mg (group H; n = 18). The two components of the IT injectate were administered sequentially (fentanyl 25 micro g diluted in 2 mL of normal saline, immediately followed by 0.5 mL of 0.5% bupivacaine). Patients were then positioned with their torso elevated at 30 degrees for 30 min. Pain scores using 0-100 visual analog scales were collected before combined spinal/epidural analgesia and at 5, 15, and 30 min after the block. Patients in Group H had a longer median duration of analgesia (122 min; range, 80-210 min) than Group P (95 min; range, 75-125 min) (P hyperbaric bupivacaine conferred an increased duration of IT analgesia compared with plain bupivacaine.

Scuba diving accidents.

Science.gov (United States)

Dembert, M L

1977-08-01

The principal scuba diving medical problems of barotrauma, air embolism and decompression sickness have as their pathophysiologic basis the Ideal Gas Law and Boyle's Law. Hyperbaric chamber recompression therapy is the only definitive treatment of air embolism and decompression sickness. However, with a basic knowledge of diving medicine, the family physician can provide effective supportive care to the patient prior to initiation of hyperbaric therapy.

Hyperbaric oxygen therapy for wound healing in diabetic rats: Varying efficacy after a clinically-based protocol

NARCIS (Netherlands)

J.W. van Neck (Han); B. Tuk (Bastiaan); E.M.G. Fijneman (Esther ); Redeker, J.J. (Jonathan J.); Talahatu, E.M. (Edwin M.); M. Tong (Miao)

2017-01-01

textabstractHyperbaric oxygen therapy (HBOT) is a clinical treatment in which a patient breathes pure oxygen for a limited period of time at an increased pressure. Although this therapy has been used for decades to assist wound healing, its efficacy for many conditions is unproven and its mechanism

Peri-anal surgery under saddle block anaesthesia comparing three different doses of hyperbaric 0.75% bupivacaine

International Nuclear Information System (INIS)

Ali, L.; Alam, W.; Abbas, M.A.; Ali, U.

2017-01-01

To compare three doses of hyperbaric 0.75% bupivacaine and measuring time for home readiness after day care perianal surgery under saddle block anaesthesia. Study Design: Non randomized controlled trial. Place and Duration of Study: The study was conducted at the department of Anaesthesia, CMH Rawalpindi from Jun 2014 to Apr 2015. Material and Methods: In this study 90 patients who presented for perianal day care surgery, were divided in three equal groups. Group A received 7.5 mg, group B 6.0 mg and group C 4.5 mg of hyperbaric 0.75% bupivacaine. Intrathecal injection was given in L4-5 space by 25 G spinal needle in sitting position. Lithotomy position was made after five minutes. After surgery patients were monitored in recovery room. After fulfilling ambulatory and discharge criteria patients were allowed to go home with attendants. Time of intrathecal injection, assessment of above criteria and time of discharge were noted and analyzed. Results: Male patients were 85.6% and females were 14.4%. Mean time of surgery was 48 +- 10.59 min. Mean time of discharge in minutes for group A was 235.86 +- 49.38, for group B 217.7 +- 42.49 and for group C 205.76 +- 32. Time of discharge was significantly different between group A and group C (p=0.02). While it was not significantly different between group A and group B (p=0.29) and between group B and group C (p=0.819). Conclusion: Lower dose of hyperbaric bupivacaine can reduce the time for home readiness compared to higher dose. Time of discharge is mainly dependent on time to micturate after saddle block anaesthesia. (author)

Nitrogen narcosis induced by repetitive hyperbaric nitrogen oxygen mixture exposure impairs long-term cognitive function in newborn mice.

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Bin Peng

Full Text Available Human beings are exposed to compressed air or a nitrogen-oxygen mixture, they will produce signs and symptoms of nitrogen narcosis such as amnesia or even loss of memory, which may be disappeared once back to the normobaric environment. This study was designed to investigate the effect of nitrogen narcosis induced by repetitive hyperbaric nitrogen-oxygen mixture exposure on long-term cognitive function in newborn mice and the underlying mechanisms. The electroencephalogram frequency was decreased while the amplitude was increased in a pressure-dependent manner during 0.6, 1.2, 1.8 MPa (million pascal nitrogen-oxygen mixture exposures in adult mice. Nitrogen narcosis in postnatal days 7-9 mice but not in adult mice induced by repetitive hyperbaric exposure prolonged the latency to find the platform and decreased the number of platform-site crossovers during Morris water maze tests, and reduced the time in the center during the open field tests. An increase in the expression of cleaved caspase-3 in the hippocampus and cortex were observed immediately on the first day after hyperbaric exposure, and this lasted for seven days. Additionally, nitrogen narcosis induced loss of the dendritic spines but not of the neurons, which may mainly account for the cognitive dysfunction. Nitrogen narcosis induced long-term cognitive and emotional dysfunction in the postnatal mice but not in the adult mice, which may result from neuronal apoptosis and especially reduction of dendritic spines of neurons.

Characterization of the Effects of Hyperbaric Oxygen on the Biochemical and Optical Properties of the Bovine Lens.

Science.gov (United States)

Lim, Julie C; Vaghefi, Ehsan; Li, Bo; Nye-Wood, Mitchell G; Donaldson, Paul J

2016-04-01

To assess the morphologic, biochemical, and optical properties of bovine lenses treated with hyperbaric oxygen. Lenses were exposed to hyperbaric nitrogen (HBN) or hyperbaric oxygen (HBO) for 5 or 15 hours, lens transparency was assessed using bright field microscopy and lens morphology was visualized using confocal microscopy. Lenses were dissected into the outer cortex, inner cortex, and core, and glutathione (GSH) and malondialdehyde (MDA) measured. Gel electrophoresis and Western blotting were used to detect high molecular weight aggregates (HMW) and glutathione mixed protein disulfides (PSSG). T2-weighted MRI was used to measure lens geometry and map the water/protein ratio to allow gradient refractive index (GRIN) profiles to be calculated. Optical modeling software calculated the change in lens optical power, and an anatomically correct model of the light pathway of the bovine eye was used to determine the effects of HBN and HBO on focal length and overall image quality. Lenses were transparent and lens morphology similar between HBN- and HBO-treated lenses. At 5- and 15-hour HBO exposure, GSH and GSSG were depleted and MDA increased in the core. Glutathione mixed protein disulfides were detected in the outer and inner cortex only with no appearance of HMW. Optical changes were detectable only with 15-hour HBO treatment with a decrease in the refractive index of the core, slightly reduced lens thickness, and an increase in optimal focal length, consistent with a hyperopic shift. This system may serve as a model to study changes that occur with advanced aging rather than nuclear cataract formation per se.

Polysulfone coating for hollow fiber artificial lungs operated at hypobaric and hyperbaric pressures.

Science.gov (United States)

High, K M; Snider, M T; Panol, G R; Richard, R B; Gray, D N

1996-01-01

Carbon dioxide transfer is increased when the gas phase of a hollow fiber membrane lung is operated at hypobaric pressures. Oxygen transfer is augmented by hyperbaric pressures. However, uncoated hollow fibers transmit gas bubbles into the blood when operated at a pressure greater than 800 mmHg and may have increased plasma leakage when operated at hypobaric pressures. Ultrathin polymer coatings may avoid this problem while reducing thrombogenicity. The authors coated microporous polypropylene hollow fibers with 380 microns outer diameter and 50 microns walls using 1, 2, 3, and 4% solutions of polysulfone in tetrahydrofuran by dipping or continuous pull through. These fibers were mounted in small membrane lung prototypes having surface areas of 70 and 187 cm2. In gas-to-gas testing, the longer the exposure time to the solution and the greater the polymer concentration, the less the permeation rate. The 3% solutions blocked bulk gas flow. The coating was 1 micron thick by mass balance calculations. During water-to-gas tests, hypobaric gas pressures of 40 mmHg absolute were tolerated, but CO2 transfer was reduced to 40% of the bare fibers. Hyperbaric gas pressures of 2,100 mmHg absolute tripled O2 transfer without bubble formation.

Hyperbaric oxygen therapy for the treatment of radiation-induced xerostomia: a systematic review.

Science.gov (United States)

Fox, Nyssa F; Xiao, Christopher; Sood, Amit J; Lovelace, Tiffany L; Nguyen, Shaun A; Sharma, Anand; Day, Terry A

2015-07-01

Radiation-induced xerostomia is one of the most common morbidities of radiation therapy in patients with head and neck cancer. However, in spite of its high rate of occurrence, there are few effective therapies available for its management. The aim of this study was to assess the efficacy of hyperbaric oxygen on the treatment of radiation-induced xerostomia and xerostomia-related quality of life. PubMed, Google Scholar, and the Cochrane Library were searched for retrospective or prospective trials assessing subjective xerostomia, objective xerostomia, or xerostomia-related quality of life. To be included, patients had to have received radiation therapy for head and neck cancer, but not hyperbaric oxygen therapy (HBOT). The systematic review initially identified 293 potential articles. Seven studies, comprising 246 patients, qualified for inclusion. Of the included studies, 6 of 7 were prospective in nature, and 1 was a retrospective study; and 2 of the 7 were controlled studies. HBOT may have utility for treating radiation-induced xerostomia refractory to other therapies. Additionally, HBOT may induce long-term improvement in subjective assessments of xerostomia, whereas other therapies currently available only provide short-term relief. The strength of these conclusions is limited by the lack of randomized controlled clinical trials. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of exposure to hyperoxic, hypobaric, and hyperbaric environments on concentrations of selected and aerobic and anaerobic fecal flora of mice.

Science.gov (United States)

Gillmore, J D; Gordon, F B

1975-03-01

Alterations in selected aerobic and anaerobic fecal microflora of the mouse were determined during exposure to hyperoxic and normoxic hypo- and hyperbaric environments. Examination of fecal cultures obtained during exposure for 6 weeks to either 60 or 77% oxygen concentration 1 atmosphere absolute revealed little alteration in the aerobic or anaerobic flora. There appeared to be only a retardation in the reduction of the Klebsiella-Enterobacter flora which normally occurs after weaning. During exposure to hypobaric environments (100% O-2, 0.2 atmosphere absolute), significant alterations in concentrations of Escherichia coli, slow lactose fermenters, Klebsiella-Enterobacter, and enterococci were found in some instances. All alterations were toward increased concentrations. Variations in concentrations of different colony types of obligately anaerobic gram-positive (anGPR) and gram-negative (anGNR) rods cultured during the same experiments also occurred. One colony type of anGPR appeared to decrease while a second type increased in numbers. Concentrations of three colony types of anGNR were generally, but not always, increased. During hyperbaric exposure (2.8% O-2, 7.5 atmospheres absolute), increased concentrations of Klebsiella-Enterobacter, E. coli, slow lactose fermenters and enterococci were also noted. Changes in numbers of both colony types of anGPR, when occurring, were in the direction of lower numbers. Alteration in numbers of anGNR were in both directions but were more frequent in the direction of higher numbers. After return to normal air for 4 weeks of either hypo- or hyperbaric exposure, fecal concentrations of all organisms tended to revert toward control values with the exception of the anGPR which remained in lower concentrations after termination of the hyperbaric exposure. These observations indicate that, despite the great variation in the fecal flora among individual mice, it is possible to discover the effects induced by altered gaseous

Tympanic membrane bleeding complications during hyperbaric oxygen treatment in patients with or without antiplatelet and anticoagulant drug treatment

NARCIS (Netherlands)

Fijen, Valerie A.; Westerweel, Peter E.; van Ooij, Pieter Jan A. M.; van Hulst, Rob A.

2016-01-01

Middle ear barotrauma (MEBt) is a frequently occurring complication of hyperbaric oxygen treatment (HBOT). High-grade MEBt may involve tympanic membrane (TM) haemorrhaging. Although many patients undergoing HBOT use antiplatelet or anticoagulant drugs, it is unknown whether these drugs increase the

Decompression Sickness and U-2 Operations: Summary of Research, Findings, and Recommendations Regarding Use of Exercise During Prebreathe

Science.gov (United States)

2010-03-01

Research Laboratory Hypobaric DCS Research Database developed at Brooks AFB, TX, which has detailed information on over 3,000 research chamber... hyperbaric oxygen therapy resulting in complete resolution of all symptoms. After instituting EDP, the same pilot flew 36 U-2 high flights without any...consultation with base SGP and USAFSAM Hyperbarics and MAJCOM/SGPA. Earlier guidance in the 1980’s was much more restrictive and, in fact, permanently

Reversibility of retinal ischemia due to central retinal artery occlusion by hyperbaric oxygen

Directory of Open Access Journals (Sweden)

Hadanny A

2016-12-01

Full Text Available Amir Hadanny,1,2 Amit Maliar,1 Gregory Fishlev,1 Yair Bechor,1 Jacob Bergan,1 Mony Friedman,1 Isaac Avni,2,3 Shai Efrati1,2,4,5 1Sagol Center for Hyperbaric Medicine and Research, Assaf Harofeh Medical Center, Zerifin, Israel; 2Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel; 3Opthalmology Department, Assaf Harofeh Medical Center, Zeirifin, Israel; 4Research and Development Unit, Assaf Harofeh Medical Center, Zerifin, Israel; 5Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv, Israel Purpose: Ischemic retinal damage can be reversed by hyperbaric oxygen therapy (HBOT as long as irreversible infarction damage has not developed. However, the time window till irreversible damage develops is still unknown. The study aim was to evaluate the effect of HBOT and determine possible markers for irreversible retinal damage.Materials and methods: Retrospective analysis of 225 patients treated with HBOT for central retinal artery occlusion (CRAO in 1999–2015. One hundred and twenty-eight patients fulfilled inclusion/exclusion criteria: age >18 years, symptoms <20 hours, and best-corrected visual acuity (BCVA <0.5 logMAR.Results: Time delay from symptoms to treatment was 7.8±3.8 hours. The BCVA was significantly improved after HBOT, from 2.14±0.50 to 1.61±0.78 (P<0.0001. The proportion of patients with clinically meaningful visual improvement was significantly higher in patients without cherry-red spot (CRS compared to patients with CRS at presentation (86.0% vs 57.6%, P<0.0001. The percentage of patients with final BCVA better than 1.0 was also significantly higher in patients without CRS vs patients with CRS at presentation (61.0% vs 7.1%, P<0.0001. There was no correlation between CRS and the time from symptoms. HBOT was found to be safe, and only 5.5% of patients had minor, reversible, adverse events.Conclusion: HBOT is an effective treatment for non-arteritic CRAO as long as CRS has not formed. The fundus findings, rather

Hyperbaric oxygen sensitizes anoxic Pseudomonas aeruginosa biofilm to ciprofloxacin

DEFF Research Database (Denmark)

Kolpen, Mette; Lerche, Christian J; Kragh, Kasper Nørskov

2017-01-01

Chronic Pseudomonas aeruginosa lung infection is characterized by the presence of endobronchial antibiotic-tolerant biofilm subject to strong oxygen (O2) depletion due to the activity of surrounding polymorphonuclear leukocytes. The exact mechanisms affecting the antibiotic susceptibility...... metabolism activity and the endogenous formation of reactive O2 radicals (ROS). In this study we aimed to apply hyperbaric oxygen treatment (HBOT) in order to sensitize anoxic P. aeruginosa agarose-biofilms established to mimic situations with intense O2 consumption by the host response in the cystic...... fibrosis (CF) lung. Application of HBOT resulted in enhanced bactericidal activity of ciprofloxacin at clinically relevant durations and was accompanied by indications of restored aerobic respiration, involvement of endogenous lethal oxidative stress and increased bacterial growth. The findings highlight...

Serum oxidized low-density lipoprotein level as a marker of oxidative stress in patients undergoing hyperbaric oxygen therapy.

Science.gov (United States)

Keskin, Kudret; Kilci, Hakan; Aksan, Gökhan; Çetinkal, Gökhan; Yıldız, Süleyman Sezai; Kocaman Türk, Füsun; Bingöl, Gülsüm

2017-09-01

Oxidative stress (OS) is involved in the pathogenesis of atherosclerosis. Hyperbaric oxygen therapy (HBOT), in which 100% oxygen is inhaled under hyperbaric pressure, may create OS. Therefore, the aim of this research was to measure the serum oxidized low-density lipoprotein (oxLDL) level in patients undergoing HBOT. Twenty-nine patients who underwent HBOT to treat various diseases were enrolled in this study. The serum oxLDL level was measured at the beginning of the first and after the 10th therapy session. There was no significant difference between the oxLDL level of patients before and after HBOT (4.96±0.1 vs. 4.94±0.1 U/mL; p=0.36). HBOT seems to be safe in terms of oxLDL production up to 10 sessions. However, further large-scale studies investigating longer duration of HBOT treatment are required to understand the role of OS.

Combination of hyperbaric oxygenation, blood ultraviolet irradiation and hemisorption in treatment of patients with postoperational peritonitis

International Nuclear Information System (INIS)

Lisak, B.I.; Ivanov, M.A.

1988-01-01

Results of treatment of patients with postoperational peritonitis are taken as examples to carry out a comparative evaluation of modern methods of correction of changes of homeostasis and detoxication-hemisorption, ultraviolet irradiation of autoblood, hyperbaric oxygenation, as well as of traditional approach to removal of intra-abdominal sepsis in isolated version. 69 refs.; 3 tabs

Hyperbaric oxygen therapy in spontaneous brain abscess patients

DEFF Research Database (Denmark)

Bartek, Jiri; Jakola, Asgeir S; Skyrman, Simon

2016-01-01

BACKGROUND: There is a need to improve outcome in patients with brain abscesses and hyperbaric oxygen therapy (HBOT) is a promising treatment modality. The objective of this study was to evaluate HBOT in the treatment of intracranial abscesses. METHOD: This population-based, comparative cohort...... study included 40 consecutive adult patients with spontaneous brain abscess treated surgically between January 2003 and May 2014 at our institution. Twenty patients received standard therapy with surgery and antibiotics (non-HBOT group), while the remaining 20 patients also received adjuvant HBOT (HBOT...... group). RESULTS: Resolution of brain abscesses and infection was seen in all patients. Two patients had reoperations after HBOT initiation (10 %), while nine patients (45 %) in the non-HBOT group underwent reoperations (p = 0.03). Of the 26 patients who did not receive HBOT after the first surgery, 15...

Microstructure and toughness of ferritic weld metal of hyperbaric welded joints

International Nuclear Information System (INIS)

Mueller, L.

1988-01-01

In the present work ferritic weld metals of hyperbaric MIG/MAG welds with pressures up to 100 bar were examined. As a result of the pressure, interactions with the shielding gas, the filler metal as well as with the welding parameters had to be expected and were consequently included in the analysis. Investigation was focused on the influence of these parameters on the chemical composition of the weld metals, the microstructure and toughness behaviour, including fracture mechanics test. Using quantitative microstructural analysis as well as fractography a correlation between microstructure and toughness has been shown. (orig.) [de

A feasibility study of a new approach to clinical radiosensitisation: hypothermia and hyperbaric oxygen in combination with pharmacological vasodilatation

International Nuclear Information System (INIS)

Sealy, R.; Harrison, G.G.; Morrell, D.; Cape Town Univ.

1986-01-01

It is proposed that hyperbaric oxygen fails in the clinical situation due to a high proportion (greater than 33%) of hypoxic cells in human tumours. The means of overcoming this problem are reviewed. Additional to hyperbaric oxygenation, moderate hypothermia (30 0 C) to allow redistribution of oxygen in the tumour is proposed. A system of externally controlled intravenous anaesthesia has been developed for the single-subject hypervaric cylinder. Pharmacological vasodilatation is induced in the anaesthetised patient who is then fluid loaded and cooled. Initial single-sensitising treatments are advocated. Twenty-nine patients with advanced mouth cancer have completed a course of this treatment, of whom five of nine were free of disease after 2 years and 10 of 21 at 1 year, with three intercurrent deaths. Fifteen have experienced local failure. This approach would appear to be practical, safe and promising. (author)

Study on the effect of hyperbaric oxygen therapy on the wound healing and the related serum indexes of rectal abscess patients after surgery

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Bo Mo, Qing He

2016-07-01

Full Text Available Objective: To observe and research the influence degree of hyperbaric oxygen therapy on wound healing and related serum indexes of rectal abscess patients after surgery. Methods: A total of 48 rectal abscess patients treated with operation in my hospital from April 2014 to August 2015 were taken as research objects, and the 48 patients were randomly divided into two groups: control group (postoperative routine treatments, 24 cases and observation group (postoperative routine treatments and hyperbaric oxygen therapy, 24 cases, and then compared the time constitutes of wound healing, the edema degrees and the related serum indexes of patients in two test groups before the operation and at 1 d, 3 d and 10 d after operation. Results: The time constitute of wound healing of observation group is better than that of control group, and the edema degree and the related serum index of observation group are lower than those of control group, and the test result of two groups have significant differences. Conclusions: The hyperbaric oxygenation therapy can effectively promote the postoperative wound healing of patients with rectal abscess, and it also has active clinical significance for the control of edema and related serum indexes.

Limited accuracy of the hyperbaric index, ambulatory blood pressure and sphygmomanometry measurements in predicting gestational hypertension and preeclampsia

NARCIS (Netherlands)

Vollebregt, Karlijn Corien; Gisolf, Janneke; Guelen, Ilja; Boer, Kees; van Montfrans, Gert; Wolf, Hans

2010-01-01

Objective The aim of this study was to validate the hyperbaric index (HBI) for first trimester prediction of preeclampsia and gestational hypertension. Methods Participants were low-risk and high-risk nulliparous women and high-risk multiparous women, and were recruited between April 2004 and June

Clinical experience with radiation enhancement by hyperbaric oxygen in children with recurrent neuroblastoma stage IV

International Nuclear Information System (INIS)

Voute, P.A.; Kleij, A.J. van der; De Kraker, J.; Hoefnagel, C.A.; Tiel-van Buul, M.M.C.; Gennip, H. van

1995-01-01

The high risk group of patients with neuroblastoma are children over 1 year with stage IV disease. Most series report a maximum of 20% survival at 5 years. For recurrent neuroblastoma stage IV, cure rates are not reported in the literature, but they are nil. Any treatment for recurrent neuroblastoma stage IV remains a therapeutic dilemma. The outcome of radiation therapy is variable. A very important factor in tumour treatment remains tumour hypoxia, and others, such as metabolic factors, also play a role. Combined application of radiation modifiers may influence the final survival rate. In an attempt to improve the survival of recurrent neuroblastoma stage IV, hyperbaric oxygen and radioionated meta-Iodobenzylguanidine (MIBG) was used in a clinical setting. Although survival may not be used as a determinant of the usefulness of a treatment for stage IV neuroblastoma disease, a better one is not available. In this study, at 28 months, a cumulative probability of survival of 32% was recorded for patients treated with [ 131 I]MIBG and hyperbaric oxygen compared to 12% for [ 131 I]MIBG treatment alone. These preliminary results are promising but further studies are needed to reveal substantial therapeutic gain. (Author)

Traumatic Brain Injury and Hyperbaric Oxygen Therapy Dawn of a New Day

Science.gov (United States)

2017-09-07

0 ... 7251 Mir-ID I 0 M.fll 73a Ocl- cll I 0 Mlr-C& 𔃻JIB ,.,..Ill 0 0 Mir-OS 𔄂 Mir-ID I 0 Mir-DI 15151 Jul .. 0 0 llOw-OI 7ll50 Jul.(J7 0 0...2ATA 2.4ATA • percent Increased circulating stem cells and better cognitive performance in traumatic brain injury subjects following hyperbaric...CD34+ bone-marrowderived stem /progenitor cells (SPCs) following HB02 • Heyboer showed a potential dose-response relation in CD34+ and CD45-dim, with

Influence of lateral decubitus positioning after combined use of hyperbaric and hypobaric ropivacaine on hemodynamic characteristics in spinal anesthesia for caesarean section.

Science.gov (United States)

Quan, Zhe-Feng; He, Hai-Li; Tian, Ming; Chi, Ping; Li, Xin

2014-01-01

Positioning of the patient during and after surgery can have significant implications on recovery. Therefore, the purpose of the present study was to determine the influence of placing patients in a lateral decubitus position for 15 min after combined use of hyperbaric and hypobaric ropivacaine and assess hemodynamic characteristics during spinal anesthesia for caesarean section. One hundred-forty patients undergoing elective cesarean delivery with combined use of hyperbaric and hypobaric ropivacaine were included in the present study. Patients meeting inclusion criteria (134) were randomly allocated into Group A: immediately turned to the supine position after induction of spinal anesthesia (n = 67) or Group B: maintained in a lateral decubitus position for 15 min before being turned to the supine position (n = 67). Primary endpoints of the study were to compare hemodynamic characteristics and sensory blockade levels in the two groups, while a secondary endpoint was to observe the incidence of complications. Both groups showed similar effects of the combined anesthetic treatment. Incidence of hypotension (43% vs 18%, P = 0.001), systolic AP hyperbaric and hypobaric ropivacaine had satisfactory anesthetic effects and a more stable hemodynamic characteristic than either drug used alone. Maintaining the patient in a lateral decubitus position for 15 min can significantly decrease the incidence of hypotension.

Effect of Electroacupuncture on Transcutaneous Oxygen Partial Pressure During Hyperbaric Oxygen Therapy in Healthy Individuals.

Science.gov (United States)

Qu, Lan; Ye, Yong; Li, Chunfeng; Gao, Guangkai

2015-01-01

The goal of hyperbaric oxygen therapy (HBOT) is to increase the oxygen (O₂) supply to the body significantly. Because of the toxic side effects and complications of hyperbaric oxygen (HBO₂), the environmental pressure and treatment time must be restricted. The research team hypothesized that other therapies administered during HBOT could safely improve the value of the arterial oxygen partial pressure (PaO₂) during HBOT and improve its therapeutic effect. The study intended to investigate whether electroacupuncture (EA) while receiving HBOT had a greater effect for healthy individuals than HBOT or EA alone or EA combined with normobaric pure oxygen (pure O₂). The research team designed a randomized, controlled trial. The study was performed in the Department of Hyperbaric Medicine at the No. 401 Hospital of the People's Liberation Army in Qingdao, China. A total of 81 volunteers were recruited. After thorough physical examination and laboratory testing, 21 volunteers were excluded from the study. Participants included 60 healthy volunteers. Participants were randomly assigned to 1 of 4 groups of 15 participants each: (1) an HBOT group, (2) an EA group, (3) an EA During HBOT group, and (4) an EA Combined With Pure O₂group. Because at the current technology level a blood gas analyzer cannot test PaO₂during HBOT, transcutaneous oxygen partial pressure (PtcO₂) of the participants was tested instead. Before, during, and after EA, variations in PtcO₂were monitored in each group. For the EA During HBOT group, (1) the increase in PtcO₂during EA was significantly greater than that observed for the other 3 groups (P > .05). The EA During HBOT method provided improvements in the efficacy, safety, and tolerability of HBOT, and the study's results partially demonstrated the accuracy of the research team's hypothesis that EA therapy applied during HBOT could safely improve the value of PtcO₂(PaO₂) during HBOT and produce a greater therapeutic effect.

Avaliação funcional e histológica da oxigenoterapia hiperbárica em ratos com lesão medular Functional and histologic evaluation of hyperbaric oxygen therapy in rats with spinal cord injury

Directory of Open Access Journals (Sweden)

Paulo Eduardo de Carvalho Galvão

2011-01-01

oxygen therapy in a hyperbaric chamber for one hour daily for a period of 30 days. The assessment of locomotor recovery was conducted on the 2nd, 9th, 16th, 23rd and 30th postoperative days, measured by the functional scale and the site of injury submitted to anatomopathological examination. RESULTS: Improved locomotor recovery was demonstrated in the rats treated with hyperbaric oxygen in the initial stages of the evaluation, but at the end of the evaluation there was no statistically significant difference between the two groups. The anatomopathological examination showed structural changes of the spinal cord in both groups. CONCLUSION: Spinal cord injury in rats evolved differently in the hyperbaric oxygen therapy group compared with the control group, in the initial phase.

Hyperbaric Versus Isobaric Bupivacaine for Spinal Anesthesia: Systematic Review and Meta-analysis for Adult Patients Undergoing Noncesarean Delivery Surgery.

Science.gov (United States)

Uppal, Vishal; Retter, Susanne; Shanthanna, Harsha; Prabhakar, Christopher; McKeen, Dolores M

2017-11-01

It is widely believed that the choice between isobaric bupivacaine and hyperbaric bupivacaine formulations alters the block characteristics for the conduct of surgery under spinal anesthesia. The aim of this study was to systematically review the comparative evidence regarding the effectiveness and safety of the 2 formulations when used for spinal anesthesia for adult noncesarean delivery surgery. Key electronic databases were searched for randomized controlled trials, excluding cesarean delivery surgeries under spinal anesthesia, without any language or date restrictions. The primary outcome measure for this review was the failure of spinal anesthesia. Two independent reviewers selected the studies and extracted the data. Results were expressed as relative risk (RR) or mean differences (MDs) with 95% confidence intervals (CIs). Seven hundred fifty-one studies were identified between 1946 and 2016. After screening, there were 16 randomized controlled clinical trials, including 724 participants, that provided data for the meta-analysis. The methodological reporting of most studies was poor, and appropriate judgment of their individual risk of bias elements was not possible. There was no difference between the 2 drugs regarding the need for conversion to general anesthesia (RR, 0.60; 95% CI, 0.08-4.41; P = .62; I = 0%), incidence of hypotension (RR, 1.15; 95% CI, 0.69-1.92; P = .58; I = 0%), nausea/vomiting (RR, 0.29; 95% CI, 0.06-1.32; P = .11; I = 7%), or onset of sensory block (MD = 1.7 minutes; 95% CI, -3.5 to 0.1; P = .07; I = 0%). The onset of motor block (MD = 4.6 minutes; 95% CI, 7.5-1.7; P = .002; I = 78%) was significantly faster with hyperbaric bupivacaine. Conversely, the duration of motor (MD = 45.2 minutes; 95% CI, 66.3-24.2; P bupivacaine. Both hyperbaric bupivacaine and isobaric bupivacaine provided effective anesthesia with no difference in the failure rate or adverse effects. The hyperbaric formulation allows for a relatively rapid motor block onset

Improvement of attention span and reaction time with hyperbaric oxygen treatment in patients with toxic injury due to mold exposure.

Science.gov (United States)

Ezra, N; Dang, K; Heuser, G

2011-01-01

It is, by now, well established that mold toxins (mycotoxins) can cause significant adverse health effects. In this study, 15 subjects who developed an attention deficit disorder (ADD) and slowing of reaction time at the time of exposure to mold toxins were identified. Deficits in attention span and reaction time were documented not only by taking a careful history, but also by performing a Test of Variables of Attention (TOVA). The TOVA test provides an objective measure of these two variables. It was found that mold-exposed subjects show statistically significant decreases in attention span and significant increases in reaction time to stimuli compared to controls. After ten sessions of hyperbaric oxygen treatment (HBOT), a statistically significant improvement was seen in both measures. This preliminary study suggests promising outcomes in treating mold-exposed patients with hyperbaric oxygen.

Effect of anemia on tumor radiosensitivity under normo and hyperbaric conditions

International Nuclear Information System (INIS)

Rojas, A.; Stewart, F.A.; Smith, K.A.; Soranson, J.A.; Randhawa, V.S.; Stratford, M.R.; Denekamp, J.

1987-01-01

The effect of chronic anemia on tumor radiosensitivity in a murine tumor has been investigated. Anemia was induced by bilateral kidney irradiation given several months before tumor implantation. Anemic, anemic transfused, and normal non-anemic age-matched tumor bearing animals were irradiated with X rays (2 F/24 hr) either in air, air plus misonidazole, or under hyperbaric oxygen. The most resistant response was that of tumors grown in normal mice treated in air. Anemia produced an increase in radiosensitivity which was further enhanced by red blood cell replacement. The most sensitive overall response was seen in the anemic-transfused group treated with HBO

Effect of cooled hyperbaric bupivacaine on unilateral spinal anesthesia success rate and hemodynamic complications in inguinal hernia surgery.

Science.gov (United States)

Tomak, Yakup; Erdivanli, Basar; Sen, Ahmet; Bostan, Habib; Budak, Ersel Tan; Pergel, Ahmet

2016-02-01

We hypothesized that cooling hyperbaric bupivacaine from 23 to 5 °C may limit the intrathecal spread of bupivacaine and therefore increase the success rate of unilateral spinal anesthesia and decrease the rate of hemodynamic complications. A hundred patients scheduled for elective unilateral inguinal hernia surgery were randomly allocated to receive 1.8 ml of 0.5 % hyperbaric bupivacaine intrathecally at either 5 °C (group I, n = 50) or at 23 °C (group II, n = 50). Following spinal block at the L2-3 interspace, the lateral decubitus position was maintained for 15 min. Unilateral spinal anesthesia was assessed and confirmed at 15 and 30 min. The levels of sensory and motor block on the operative side were evaluated until complete resolution. The rate of unilateral spinal anesthesia at 15 and 30 min was significantly higher in group I (p = 0.015 and 0.028, respectively). Hypotensive events and bradycardia were significantly rarer in group I (p = 0.014 and 0.037, respectively). The density and viscosity of the solution at 5 °C was significantly higher than at 23 °C (p < 0.0001). Compared with group II, sensory block peaked later in group I (17.4 vs 12.6 min) and at a lower level (T9 vs T7), and two-segment regression of sensory block (76.4 vs 84.3 min) and motor block recovery was shorter (157.6 vs 193.4 min) (p < 0.0001). Cooling of hyperbaric bupivacaine to 5 °C increased the density and viscosity of the solution and the success rate of unilateral spinal anesthesia, and decreased the hemodynamic complication rate.

Rehabilitation of oral function in head and neck cancer patients after radiotherapy with implant-retained dentures : Effects of hyperbaric oxygen therapy

NARCIS (Netherlands)

Schoen, P.J.; Raghoebar, G.M.; Bouma, J.; Reintsema, H.; Vissink, A.; Sterk, W.; Roodenburg, J.L.N.

Surgical treatment of malignancies in the oral cavity and subsequent radiotherapy often result in an anatomic and physiological oral condition unfavorable for prosthodontic rehabititation. The objective of this prospective study was to assess the effect of hyperbaric oxygen therapy on treatment

Ionization chamber

International Nuclear Information System (INIS)

Jilbert, P.H.

1975-01-01

The invention concerns ionization chambers with particular reference to air-equivalent ionization chambers. In order to ensure that similar chambers have similar sensitivities and responses the surface of the chamber bounding the active volume carries a conducting material, which may be a colloidal graphite, arranged in the form of lines so that the area of the conducting material occupies only a small proportion of the area of said surface. (U.S.)

Hyperbaric oxygen therapy in management of severe dry socket pain

International Nuclear Information System (INIS)

Abdellateef, Abdelamajeed; Elrefai, Jamil; AlJadid, Omar; Alabbadi, Amjad

2009-01-01

To assess the role and efficacy of hyperbaric oxygen therapy (HBOT) in the treatment of pain resulting from dry socket. From January 2006 to May 2007, 25 patients who had been diagnosed by the oral surgeon in the Dental Department of Princess Haya Hospital, Aqaba, Jordan with dry socket with severe intolerable pain, untreated with the classical treatments, were treated with HBOT. Fifteen patients (60%) were treated in a single HBOT session after which an almost complete resolution of pain took place, 7 patients (28%) were treated in 2 sessions and 3 patients (12%) needed 3 HBOT sessions to cure the pain. This preliminary study to assess the role of HBOT in the treatment of dry socket pain showed a great reduction of pain intensity of dry socket following administration of HBOT. (author)

Hyperbaric oxygen therapy as an effective adjunctive treatment for chronic Lyme disease

Directory of Open Access Journals (Sweden)

Chien-Yu Huang

2014-05-01

Full Text Available Lyme disease is the most commonly reported vector-borne illness in the United States, but it is relatively rare in Taiwan. Lyme disease can be treated with antibiotic agents, but approximately 20% of these patients experience persistent or intermittent subjective symptoms, so-called chronic Lyme disease (CLD. The mechanisms of CLD remain unclear and the symptoms related to CLD are difficult to manage. Hyperbaric oxygen therapy (HBOT was applied in CLD therapy in the 1990s. However, reported information regarding the effectiveness of HBOT for CLD is still limited. Here, we present a patient with CLD who was successfully treated with HBOT.

Reducing the concentration to 0.4% enantiomeric excess hyperbaric levobupivacaine (s75: r25) provides unilateral spinal anesthesia. Study with different volumes.

Science.gov (United States)

Imbelloni, Luiz Eduardo; Gouveia, Marildo A; Carneiro, Antonio Fernando; Grigorio, Renata

2012-01-01

Unilateral spinal anesthesia may be obtained with hypobaric or hyperbaric solution. The objective of this study was to compare different doses of enantiomeric excess hyperbaric levobupivacaine to achieve unilateral spinal anesthesia. One hundred and twenty patients were randomized to receive 4 mg, 6 mg or 8 mg of 0.4% enantiomeric excess levobupivacaine. The solutions were administered at the L3-L4, with the patient in a lateral position and kept at this position according to dose administration for 5, 10 or 15 minutes. Sensory block (pinprick) and motor block (scale 0-3) were compared between the operated and contralateral sides. The onset of analgesia was rapid and comparable between groups. Sensory block was significantly higher in the operated than in nonoperated limb at all times of evaluation. Increasing the dose by 1 mL (2mg) corresponded to an increase of two segments in the mode for the operated side. In the operated side, motor block (MB = 3) of patients occurred in 31 (77.5%) with 4 mg, 38 (95%) with 6 mg, and 40 (100%) with 8 mg. There was a positive correlation between increased dose, blockade duration, and hypotension. All patients were satisfied with the technique used. Spinal anesthesia with different volumes of enantiomeric excess hyperbaric bupivacaine (S75: R25) provided a 78% incidence of unilateral spinal block, with the smallest dose used (4 mg) the most efficient. Copyright © 2012 Elsevier Editora Ltda. All rights reserved.

Research Report: Intermittent hypobaric hypoxia and hyperbaric oxygen on GAP-43 in the rat carotid body.

Science.gov (United States)

Peng, Zhengwu; Fan, Juan; Liu, Ling; Kuang, Fang; Xue, Fen; Wang, Bairen

2015-01-01

Adaptive changes in the carotid body (CB) including the expression of the growth-associated protein-43 (GAP-43) have been studied in response to low, but not high, oxygen exposure. Expression of GAP-43 in the CB of rats under different atmospheric pressures and oxygen partial pressure (PO2) conditions was investigated. Mature male Sprague-Dawley rats were exposed to intermittent hypobaric hypoxia (IHH, 0, 1, 2 and 3 weeks), intermittent hyperbaric oxygen (IHBO2, 0, 1, 5 and 10 days, sacrificed six hours or 24 hours after the last HBO2 exposure), and intermittent hyperbaric normoxia (IHN, same treatment pattern as IHBO2). GAP-43 was highly expressed (mainly in type I cells) in the CB of normal rats. IHH u-regulated GAP-43 expression in the CB with significant differences (immunohistochemical staining [IHC]: F(3,15)=40.64, P GAP-43 expression in the CB was inhibited by IHBO2 (controls vs. IHBO2 groups, IHC: F(6,30) = 15.85, P GAP-43 expression were found for IHN. These findings indicated that different PO2 conditions, but not air pressures, played an important role in the plasticity of the CB, and that GAP-43 might be a viable factor for the plasticity of the CB.

Glove box chamber

International Nuclear Information System (INIS)

Cox, M.E.; Cox, M.E.

1975-01-01

An environmental chamber is described which enables an operator's hands to have direct access within the chamber without compromising a special atmosphere within such chamber. A pair of sleeves of a flexible material are sealed to the chamber around associated access apertures and project outwardly from such chamber. Each aperture is closed by a door which is openable from within the sleeve associated therewith so that upon an operator inserting his hand and arm through the sleeve, the operator can open the door to have access to the interior of the chamber. A container which is selectively separable from the remainder of the chamber is also provided to allow objects to be transferred from the chamber without such objects having to pass through the ambient atmosphere. An antechamber permitting objects to be passed directly into the chamber from the ambient atmosphere is included. (auth)

Minimum effective local anesthetic dose of intrathecal hyperbaric ropivacaine and bupivacaine for cesarean section

Institute of Scientific and Technical Information of China (English)

GENG Zhi-yu; WANG Dong-xin; WU Xin-min

2011-01-01

Background Intrathecal anesthesia is commonly used for cesarean section. Bupivacaine and ropivacaine have all been used as intrathecal drugs. The minimum effective local anesthetic dose (MLAD) of intrathecal ropivacaine for nonobstetric patients has been reported. However, few data are available on the MLAD of hyperbaric ropivacine for obstetric patients and the relative potency to bupivacaine has not been fully determined. In this study, we sought to determine the MLAD of intrathecal ropivacaine and bupivacaine for elective cesarean section and to define their relative potency ratio.Methods We enrolled forty parturients undergoing elective cesarean section under combined spinal-epidural anesthesia and randomized them to one of two groups to receive intrathecal 0.5% hyperbaric ropivacaine or bupivacaine.The initial dose was 10 mg, and was increased in increments of 1 mg, using the technique of up-down sequential allocation. Efficacy was accepted if adequate sensory dermatomal anesthesia to pin prick to T7 or higher was attained within 20 minutes after intrathecal injection, and required no supplementary epidural injection for procedure until at least 50 minutes after the intrathecal injection.Results The intrathecal MLAD was 9.45 mg (95%confidence interval (CI), 8.45-10.56 mg) for ropivacaine and 7.53 mg (95%CI, 7.00-8.10 mg) for bupivacaine. The relative potency ratio was 0.80 (95% Cl, 0.74-0.85) for ropivacaine/bupivacaine when given intrathecally in cesarean section.Conclusion Ropivacaine is 20% less potent than bupivacaine during intrathecal anesthesia for cesarean delivery.

wire chamber

CERN Multimedia

Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

Test chamber

NARCIS (Netherlands)

Leferink, Frank Bernardus Johannes

2009-01-01

A test chamber for measuring electromagnetic radiation emitted by an apparatus to be tested or for exposing an apparatus to be tested to an electromagnetic radiation field. The test chamber includes a reverberation chamber made of a conductive tent fabric. To create a statistically uniform field in

Optic neuropathy following an altitude exposure.

Science.gov (United States)

Steigleman, Allan; Butler, Frank; Chhoeu, Austin; O'Malley, Timothy; Bower, Eric; Giebner, Stephen

2003-09-01

This case report describes a 20-yr-old man who presented with retro-orbital pain and blurred vision in his left eye 3 wk after an altitude exposure in a hypobaric chamber. He was found to have significant deficits in color vision and visual fields consistent with an optic neuropathy in his left eye. The patient was diagnosed with decompression sickness and treated with hyperbaric oxygen with a U.S. Navy Treatment Table VI. All signs and symptoms resolved with a single hyperbaric oxygen treatment but recurred. A head MRI revealed a left frontoethmoid sinus opacity. A concomitant sinusitis was diagnosed. The patient had full resolution of symptoms after a total of four hyperbaric oxygen treatments and antibiotic therapy at 6-wk follow-up. Although a para-infectious etiology for this patient's optic neuropathy cannot be excluded, his history of altitude exposure and significant, rapid response to hyperbaric oxygen treatment strongly implies decompression sickness in this case.

Defense Health Care: Research on Hyperbaric Oxygen Therapy to Treat Traumatic Brain Injury and Post-Traumatic Stress Disorder

Science.gov (United States)

2015-12-01

Traumatic Brain Injury and Post - Traumatic Stress Disorder Why GAO Did This Study TBI and PTSD are signature...injury (TBI) and post - traumatic stress disorder ( PTSD ), most of which were focused solely on TBI (29 articles). The 32 articles consisted of 7 case...Case Report Articles on Hyperbaric Oxygen Therapy to Treat Traumatic Brain Injury (TBI) or Post - Traumatic Stress Disorder ( PTSD ),

Breathing Air Purification for Hyperbaric Purposes, Part II

Directory of Open Access Journals (Sweden)

Woźniak Arkadiusz

2015-03-01

Full Text Available Determining the efficiency of breathing air purification for hyperbaric purposes with the use of filtration systems is of a crucial importance. However, when the Polish Navy took samples of breathing air from their own filtration plant for quality purposes, these were found to not meet the required standard. The identification of this problem imposed the need to undertake actions aimed at the elimination of the identified disruptions in the process of breathing air production, with the objective of assuring its proper quality. This study presents the results of the initial tests on the air supply sources utilised by the Polish Navy, which were carried out for the purpose of setting a proper direction of future works and implementing corrective measures in order to optimise the breathing air production process. The obtained test results will be used in a subsequent publication devoted to the assessment of the level of efficiency of air purification with the use of a multifaceted approach consisting in the utilisation of various types of air supply sources and different configurations of purification systems.

Aspectos legais da enfermagem hiperbárica brasileira: por que regulamentar? Aspectos legales de la enfermería hiperbárica brasileña: ¿por que reglamentar? Legal issues of Brazilian hyperbaric nursing: why regulate?

Directory of Open Access Journals (Sweden)

Leila Milman Alcantara

2010-04-01

Full Text Available Este estudo objetivou apontar as necessidades de normatizar a assistência de enfermagem relacionada à oxigenação hiperbárica e regulamentar as condições de trabalho para a equipe de enfermagem que atua nessa área. Aborda-se a legislação existente na Sociedade Brasileira de Medicina Hiperbárica, no Capítulo Brasileiro da Undersea Hyperbaric Medical Society, nas Normas Reguladoras do Ministério do Trabalho e no Código de Ética dos Profissionais de Enfermagem, como instrumentos ainda insuficientes para legalização do Enfermeiro Hiperbárico e de seus procedimentos nas condições hiperbáricas e ambientes pressurizados. Permitiu refletir quanto a divulgação do estado da arte da enfermagem hiperbárica, bem como a incorporação dessa atividade na relação de especialidades constantes da Resolução COFEN 290/2004 e de cursos de pós-graduação em Enfermagem.Este estudio objetivó apuntar necesidades de normalizar la atención de enfermería relacionada con la oxigenación hiperbárica y regular condiciones de trabajo para el equipo de enfermería de esta área. Se abarca la legislación existente en la Sociedad Brasileña de Medicina Hiperbárica, capitulo Brasileño de la Undersea Hyperbaric Medical Society, en las Normas Reguladoras del Ministerio del Trabajo y en el Código de Ética de los Profesionales de Enfermería, como instrumentos aún insuficientes para legalizar el enfermero Hiperbárico, sus procedimientos en condiciones hiperbáricas y ambientes presurizados. Permitió reflejar sobre la difusión del estado del arte de la enfermería hiperbárica, así como incorporación de esta actividad en la relación de las especialidades que están en la Resolución COFEN 290/2004 y cursos de postgrado en enfermería.This study aimed to show the needs to standardize nursing care related to hyperbaric oxygenation and regulate working conditions for nursing staff that works on this area. They approach the legislation at the

Neuroprotective effect of hyperbaric oxygen therapy in a juvenile rat model of repetitive mild traumatic brain injury

Directory of Open Access Journals (Sweden)

Lei Huang

2016-01-01

Full Text Available Repetitive mild traumatic brain injury (rmTBI is an important medical concern for adolescent athletes that can lead to long-term disabilities. Multiple mild injuries may exacerbate tissue damage resulting in cumulative brain injury and poor functional recovery. In the present study, we investigated the increased brain vulnerability to rmTBI and the effect of hyperbaric oxygen treatment using a juvenile rat model of rmTBI. Two episodes of mild cortical controlled impact (3 days apart were induced in juvenile rats. Hyperbaric oxygen (HBO was applied 1 hour/day × 3 days at 2 atmosphere absolute consecutively, starting at 1 day after initial mild traumatic brain injury (mTBI. Neuropathology was assessed by multi-modal magnetic resonance imaging (MRI and tissue immunohistochemistry. After repetitive mTBI, there were increases in T2-weighted imaging-defined cortical lesions and susceptibility weighted imaging-defined cortical microhemorrhages, correlated with brain tissue gliosis at the site of impact. HBO treatment significantly decreased the MRI-identified abnormalities and tissue histopathology. Our findings suggest that HBO treatment improves the cumulative tissue damage in juvenile brain following rmTBI. Such therapy regimens could be considered in adolescent athletes at the risk of repeated concussions exposures.

Changes of pressure and humidity affect olfactory function.

Science.gov (United States)

Kuehn, Michael; Welsch, Heiko; Zahnert, Thomas; Hummel, Thomas

2008-03-01

The present study aimed at investigating the question whether olfactory function changes in relation to barometric pressure and humidity. Using climate chambers, odor threshold and discrimination for butanol were tested in 75 healthy volunteers under hypobaric and hyperbaric, and different humidity conditions. Among other effects, olfactory sensitivity at threshold level, but not suprathreshold odor discrimination, was impaired in a hypobaric compared to a hyperbaric milieu, and thresholds were lower in humid, compared to relatively dry conditions. In conclusion, environmental conditions modulate the sense of smell, and may, consecutively, influence results from olfactory tests.

Is additional hyperbaric oxygen therapy cost-effective for treating ischemic diabetic ulcers? Study protocol for the Dutch DAMOCLES multicenter randomized clinical trial?

NARCIS (Netherlands)

Stoekenbroek, Robert M.; Santema, Trientje B.; Koelemay, Mark J. W.; van Hulst, Rob A.; Legemate, Dink A.; Reekers, Jim A.; Ubbink, Dirk T.

2015-01-01

The value of hyperbaric oxygen therapy (HBOT) in the treatment of diabetic ulcers is still under debate. Available evidence suggests that HBOT may improve the healing of diabetic ulcers, but it comes from small trials with heterogeneous populations and interventions. The DAMOCLES-trial will assess

Comparison of the hemodynamic effects of lateral and sitting positions during induction of spinal anaesthesia for caesarean section using Hyperbaric Bupivacaine

International Nuclear Information System (INIS)

Ali, M.; Naqvi, S.E.H.

2018-01-01

To compare the frequency of hypotension of sitting versus lateral position during induction of spinal anesthesia for elective LSCS using Hyperbaric Bupivacaine. Study Design: Randomized control trial. Place and Duration of Study: The study was conducted at Military Hospital Rawalpindi, a tertiary care hospital, after seeking hospital ethics committee permission. Study was carried out for six months, from Nov 2014 to May 2015. Patient and Methods: A total of 130 participants achieving the inclusion criteria were picked up for this study. Patients were randomized into group-S and group-L (65 in each group). Group-S received spinal anesthesia using 0.75% hyperbaric Bupivacaine in sitting position and group-L in left lateral position. Maternal Blood pressure was measured before Induction (baseline) and every 3 min after subarachnoid injection for 15 min and final outcome measured at 15 minutes. Decrease in systolic blood pressure of >20% from baseline or a value <90 mmHg was considered as hypotension. Results: The age of the patients ranged between 25-35 years. Average age of participants were 29.18 +- 2.80 and 29.12 +- 2.52 in group S and L, respectively. In group-S hypotension developed in 34 patients (52.3%) and in group-L hypotension was observed in 20 patients (30.7%), (p=0.013). Mean weight in group-S was 71.77 +- 2.82 and in group-L was 70.91 +- 2.05. Stratification with regard to age and ASA status was carried out. Conclusion: Occurrence of Hypotension was significantly less frequent when spinal anesthesia was induced to patients in the left lateral position, for elective caesarean using 0.75% Hyperbaric Bupivacaine compared to the sitting position. (author)

The Mobile Chamber

Science.gov (United States)

Scharfstein, Gregory; Cox, Russell

2012-01-01

A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

Guide to Altitude Decompression Sickness Research

Science.gov (United States)

2010-05-01

fitness flight gender growth helium hormone human hyperbaric hypobaric hypoxia incidence injury interface interruption intra in-vitro isobaric male...exposure in hypobaric chambers and, due to its omission of other training, was not adequate for any other use. The two items required prior to...were kept in the contractor lab. 3. Hypobaric exposure records (Research Chamber Flight Records, including AF Forms 361) were kept by Altitude and

Drift chamber

International Nuclear Information System (INIS)

Inagaki, Yosuke

1977-01-01

Drift chamber is becoming an important detector in high energy physics as a precision and fast position detector because of its high spatial resolution and count-rate. The basic principle is that it utilizes the drift at constant speed of electrons ionized along the tracks of charged particles towards the anode wire in the nearly uniform electric field. The method of measuring drift time includes the analog and digital ones. This report describes about the construction of and the application of electric field to the drift chamber, mathematical analysis on the electric field and equipotential curve, derivation of spatial resolution and the factor for its determination, and selection of gas to be used. The performance test of the chamber was carried out using a small test chamber, the collimated β source of Sr-90, and 500 MeV/C electron beam from the 1.3 GeV electron synchrotron in the Institute of Nuclear Study, University of Tokyo. Most chambers to date adopted one dimensional read-out, but it is very advantageous if the two dimensional read-out is feasible with one chamber when the resolution in that direction is low. The typical methods of delay line and charge division for two dimensional read-out are described. The development of digital read-out system is underway, which can process the signal of a large scale drift chamber at high speed. (Wakatsuki, Y.)

Multiple chamber ionization detector

International Nuclear Information System (INIS)

Solomon, E.E.

1980-01-01

A multi-chambered ionisation detector enables the amount of radiation entering each chamber from a single radioactive, eg β, source to be varied by altering the proportion of the source protruding into each chamber. Electrodes define chambers and an extended radioactive source is movable to alter the source length in each chamber. Alternatively, the source is fixed relative to outer electrodes but the central electrode may be adjusted by an attached support altering the chamber dimensions and hence the length of source in each. Also disclosed are a centrally mounted source tiltable towards one or other chamber and a central electrode tiltable to alter chamber dimensions. (U.K.)

Doriot Climatic Chambers

Data.gov (United States)

Federal Laboratory Consortium — The Doriot Climatic Chambers are two, 60-feet long, 11-feet high, 15-feet wide chambers that are owned and operated by NSRDEC. The Doriot Climatic Chambers are among...

Ionization chamber

International Nuclear Information System (INIS)

1977-01-01

An improved ionization chamber type X-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is placed next to the anode and is maintained at a voltage intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting towards the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

Surface and 60 FSW Performance Testing of the Modified MBS 2000 Closed Circuit Oxygen Rebreather

National Research Council Canada - National Science Library

Fothergill, David

2007-01-01

... into the system during a treatment. Since all previous testing had been performed at 1 ATA, a second major objective for the FY06 tests was to evaluate the modified MBS 2000 rebreather at 60 fsw in a hyperbaric chamber...

Effects of hyperbaric oxygen on Pseudomonas aeruginosa susceptibility to imipenem and macrophages.

Science.gov (United States)

Lima, Flavia Luna; Joazeiro, Paulo Pinto; Lancellotti, Marcelo; de Hollanda, Luciana Maria; de Araújo Lima, Bruna; Linares, Edlaine; Augusto, Ohara; Brocchi, Marcelo; Giorgio, Selma

2015-01-01

The seriousness to treat burn wounds infected with Pseudomonas aeruginosa led us to examine whether the effect of the carbapenem antibiotic imipenem is enhanced by hyperbaric oxygen (HBO). The effects of HBO (100% O2, 3 ATA, 5 h) in combination with imipenen on bacterial counts of six isolates of P. aeruginosa and bacterial ultrastructure were investigated. Infected macrophages were exposed to HBO (100% O2, 3 ATA, 90 min) and the production of reactive oxygen species monitored. HBO enhanced the effects of imipenen. HBO increased superoxide anion production by macrophages and likely kills bacteria by oxidative mechanisms. HBO in combination with imipenem can be used to kill P. aeruginosa in vitro and such treatment may be beneficial for the patients with injuries containing the P. aeruginosa.

Neurobiological insight into hyperbaric hyperoxia.

Science.gov (United States)

Micarelli, A; Jacobsson, H; Larsson, S A; Jonsson, C; Pagani, M

2013-09-01

Hyperbaric hyperoxia (HBO) is known to modulate aerobic metabolism, vasoreactivity and blood flow in the brain. Nevertheless, mechanisms underlying its therapeutic effects, especially in traumatic brain injury (TBI) and stroke patients, are debated. The present study aimed at investigating regional cerebral blood flow (rCBF) distribution during acute HBO exposure. Regional cerebral blood flow response was investigated in seven healthy subjects exposed to either normobaric normoxia or HBO with ambient pressure/inspired oxygen pressure of 101/21 and 250/250 kPa respectively. After 40 min at the desired pressure, they were injected a perfusion tracer and subsequently underwent brain single photon emission computed tomography. rCBF distribution changes in the whole brain were assessed by Statistical Parametric Mapping. During HBO, an increased relative rCBF distribution was found in sensory-motor, premotor, visual and posterior cingulate cortices as well as in superior frontal gyrus, middle/inferior temporal and angular gyrus and cerebellum, mainly in the dominant hemisphere. During normobaric normoxia, a higher (99m) Tc-HMPAO distribution in the right insula and subcortical structures as well as in bilateral hippocampi and anterior cingulated cortex was found. The present study firstly confirmed the rCBF distribution increase during HBO in sensory-motor and visual cortices, and it showed for the first time a higher perfusion tracer distribution in areas encompassed in dorsal attention system and in default mode network. These findings unfold both the externally directed cognition performance improvement related to the HBO and the internally directed cognition states during resting-state conditions, suggesting possible beneficial effects in TBI and stroke patients. © 2013 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Optical Imaging of Tumor Response to Hyperbaric Oxygen Treatment and Irradiation in an Orthotopic Mouse Model of Head and Neck Squamous Cell Carcinoma

NARCIS (Netherlands)

J.A.M. Braks (Joanna); L. Spiegelberg (Linda); S. Koljenović (Senada); Y. Ridwan (Yanto); S. Keereweer (Stijn); R. Kanaar (Roland); E.B. Wolvius (Eppo); J. Essers (Jeroen)

2015-01-01

textabstractPurpose: Hyperbaric oxygen therapy (HBOT) is used in the treatment of radiation-induced tissue injury but its effect on (residual) tumor tissue is indistinct and therefore investigated in this study. Procedures: Orthotopic FaDu tumors were established in mice, and the response of the

Hyperbaric Oxygen Treatment of Chronic Refractory Radiation Proctitis: A Randomized and Controlled Double-Blind Crossover Trial With Long-Term Follow-Up

International Nuclear Information System (INIS)

Clarke, Richard E.; Tenorio, L. M. Catalina; Hussey, James R.; Toklu, Akin S.; Cone, D. Lindsie; Hinojosa, Jose G.; Desai, Samir P.; Dominguez Parra, Luis; Rodrigues, Sylvia D.; Long, Robert J.; Walker, Margaret B.

2008-01-01

Purpose: Cancer patients who undergo radiotherapy remain at life-long risk of radiation-induced injury to normal tissues. We conducted a randomized, controlled, double-blind crossover trial with long-term follow-up to evaluate the effectiveness of hyperbaric oxygen for refractory radiation proctitis. Methods and Materials: Patients with refractory radiation proctitis were randomized to hyperbaric oxygen at 2.0 atmospheres absolute (Group 1) or air at 1.1 atmospheres absolute (Group 2). The sham patients were subsequently crossed to Group 1. All patients were re-evaluated by an investigator who was unaware of the treatment allocation at 3 and 6 months and Years 1-5. The primary outcome measures were the late effects normal tissue-subjective, objective, management, analytic (SOMA-LENT) score and standardized clinical assessment. The secondary outcome was the change in quality of life. Results: Of 226 patients assessed, 150 were entered in the study and 120 were evaluable. After the initial allocation, the mean SOMA-LENT score improved in both groups. For Group 1, the mean was lower (p 0.0150) and the amount of improvement nearly twice as great (5.00 vs. 2.61, p = 0.0019). Similarly, Group 1 had a greater portion of responders per clinical assessment than did Group 2 (88.9% vs. 62.5%, respectively; p 0.0009). Significance improved when the data were analyzed from an intention to treat perspective (p = 0.0006). Group 1 had a better result in the quality of life bowel bother subscale. These differences were abolished after the crossover. Conclusion: Hyperbaric oxygen therapy significantly improved the healing responses in patients with refractory radiation proctitis, generating an absolute risk reduction of 32% (number needed to treat of 3) between the groups after the initial allocation. Other medical management requirements were discontinued, and advanced interventions were largely avoided. Enhanced bowel-specific quality of life resulted

Reducing pulmonary injury by hyperbaric oxygen preconditioning during simulated high altitude exposure in rats.

Science.gov (United States)

Li, Zhuo; Gao, Chunjin; Wang, Yanxue; Liu, Fujia; Ma, Linlin; Deng, Changlei; Niu, Ko-Chi; Lin, Mao-Tsun; Wang, Chen

2011-09-01

Hyperbaric oxygen preconditioning (HBO₂P + HAE) has been found to be beneficial in preventing the occurrence of ischemic damage to brain, spinal cord, heart, and liver in several disease models. In addition, pulmonary inflammation and edema are associated with a marked reduction in the expression levels of both aquaporin (AQP) 1 and AQP5 in the lung. Here, the aims of this study are first to ascertain whether acute lung injury can be induced by simulated high altitude in rats and second to assess whether HBO2P + HAE is able to prevent the occurrence of the proposed high altitude-induced ALI. Rats were randomly divided into the following three groups: the normobaric air (NBA; 21% O₂ at 1 ATA) group, the HBO₂P + high altitude exposure (HAE) group, and the NBA + HAE group. In HBO₂P + HAE group, animals received 100% O₂ at 2.0 ATA for 1 hour per day, for five consecutive days. In HAE groups, animals were exposed to a simulated HAE of 6,000 m in a hypobaric chamber for 24 hours. Right after being taken out to the ambient, animals were anesthetized generally and killed and thoroughly exsanguinated before their lungs were excised en bloc. The lungs were used for both histologic and molecular evaluation and analysis. In NBA + HAE group, the animals displayed higher scores of alveolar edema, neutrophil infiltration, and hemorrhage compared with those of NBA controls. In contrast, the levels of both AQP1 and AQP5 proteins and mRNA expression in the lung in the NBA + HAE group were significantly lower than those of NBA controls. However, the increased lung injury scores and the decreased levels of both AQP1 and AQP5 proteins and mRNA expression in the lung caused by HAE was significantly reduced by HBO₂P + HAE. Our results suggest that high altitude pulmonary injury may be prevented by HBO2P + HAE in rats.

Empleo de la oxigenoterapia mediante cámara hiperbárica en cirugía oral y maxilofacial The use of oxygen therapy by means of the hyperbaric chamber in oral and maxillofacial surgery

Directory of Open Access Journals (Sweden)

J.I. Iriarte Ortabe

2006-02-01

Full Text Available La oxigenoterapia hiperbárica (OHB es una modalidad de terapéutica física que se fundamenta en la obtención de presiones parciales de oxígeno elevadas, al respirar oxígeno puro en el interior de una cámara a una presión superior a la atmosférica. El objetivo de esta revisión es clarificar los mecanismos de acción y los efectos de esta terapéutica física, los problemas que puede plantear y sobre todo las indicaciones actuales. En cirugía oral y maxilofacial, la OHB se utiliza como tratamiento complementario en procesos de osteítis y osteomielitis maxilo-mandibular, en infecciones necrotizantes de partes blandas (a nivel cervical, periodontal, gingival,…, en la prevención (muy importante y el tratamiento de la osteradionecrosis, en los retrasos de cicatrización (de fracturas, de implantes dentales, de injertos/colgajos de difícil viabilidad, en la rehabilitación implantológica de pacientes oncológicos irradiados. Es preciso utilizar los protocolos establecidos y generar estudios que sostengan científicamente su utilización; de este modo se podría paliar la poca consistencia de los estudios publicados que hemos encontrado.Hyperbaric oxygen therapy (HBO is a physical therapeutic modality based on obtaining high partial pressures of oxygen, on breathing pure oxygen inside a chamber at a pressure that is greater than that of the atmosphere. The object of this revision is to clarify the action mechanisms and the effects of the physical therapy, the problems that may arise and more especially the current indications for its use. In oral and maxillofacial surgery, HBO is used as complementary treatment for maxillo-mandibular osteitis and osteomyelitis, for necrotizing infections of soft tissue (on a cervical, periodontal, gingival... level, for the prevention (very important and treatment of osteoradionecrosis, for healing delays (fractures, dental implants, grafts/flaps with difficult viability, for implantological

The effect of rapid decompression on femur blood flow of rabbits

International Nuclear Information System (INIS)

Yu Shaoning; Tian Wuxun; Zhu Xiangqi

1997-01-01

PURPOSE: To study the influence of regional blood flow in femur trochanter (FT) of rabbits' under rapid decompression after exposure to hyperbaric air. METHODS: Rabbits were placed in a hyperbaric chamber and exposed to the pressure of 0.5 MPa for 1.5 h, and the pressure was reduced to the atmosphere pressure at a uniform rate of 0.03 mPa/min. The regional blood flow of FT in rabbits were measured with 133 Xe washout methods. RESULTS: The normal average regional blood flow in left and right FT were 14.5 +- 1.7 and 14.1 +- 1.9 ml/(min·100g) respectively. After exposure to hyperbaric air with rapid decompression, the average regional blood flow of left and right FT were 11.1 +- 1.2 and 10.5 +- 1.6 ml/(min·100g) respectively. But the symptoms of dysbarism in these rabbits were various each other. CONCLUSIONS: After being exposed to hyperbaric air with rapid decompression, the blood flow of rabbits' femur trochanter were noticeably reduced

[Diagnosis and treatment of diving accidents. New German guidelines for diving accidents 2014-2017].

Science.gov (United States)

Jüttner, B; Wölfel, C; Liedtke, H; Meyne, K; Werr, H; Bräuer, T; Kemmerer, M; Schmeißer, G; Piepho, T; Müller, O; Schöppenthau, H

2015-06-01

In 2015 the German Society for Diving and Hyperbaric Medicine (GTÜM) and the Swiss Underwater and Hyperbaric Medical Society (SUHMS) published the updated guidelines on diving accidents 2014-2017. These multidisciplinary guidelines were developed within a structured consensus process by members of the German Interdisciplinary Association for Intensive Care and Emergency Medicine (DIVI), the Sports Divers Association (VDST), the Naval Medical Institute (SchiffMedInst), the Social Accident Insurance Institution for the Building Trade (BG BAU), the Association of Hyperbaric Treatment Centers (VDD) and the Society of Occupational and Environmental Medicine (DGAUM). This consensus-based guidelines project (development grade S2k) with a representative group of developers was conducted by the Association of Scientific Medical Societies in Germany. It provides information and instructions according to up to date evidence to all divers and other lay persons for first aid recommendations to physician first responders and emergency physicians as well as paramedics and all physicians at therapeutic hyperbaric chambers for the diagnostics and treatment of diving accidents. To assist in implementing the guideline recommendations, this article summarizes the rationale, purpose and the following key action statements: on-site 100% oxygen first aid treatment, still patient positioning and fluid administration are recommended. Hyperbaric oxygen (HBO) recompression remains unchanged the established treatment in severe cases with no therapeutic alternatives. The basic treatment scheme recommended for diving accidents is hyperbaric oxygenation at 280 kPa. For quality management purposes there is a need in the future for a nationwide register of hyperbaric therapy.

Peltier-based cloud chamber

Science.gov (United States)

Nar, Sevda Yeliz; Cakir, Altan

2018-02-01

Particles produced by nuclear decay, cosmic radiation and reactions can be identified through various methods. One of these methods that has been effective in the last century is the cloud chamber. The chamber makes visible cosmic particles that we are exposed to radiation per second. Diffusion cloud chamber is a kind of cloud chamber that is cooled by dry ice. This traditional model has some application difficulties. In this work, Peltier-based cloud chamber cooled by thermoelectric modules is studied. The new model provided uniformly cooled base of the chamber, moreover, it has longer lifetime than the traditional chamber in terms of observation time. This gain has reduced the costs which spent each time for cosmic particle observation. The chamber is an easy-to-use system according to traditional diffusion cloud chamber. The new model is portable, easier to make, and can be used in the nuclear physics experiments. In addition, it would be very useful to observe Muons which are the direct evidence for Lorentz contraction and time expansion predicted by Einsteins special relativity principle.

Some problems of treating acute arterial obstruction using hyperbaric oxygenation ultraviolet irradiation of blood and hemosorption

International Nuclear Information System (INIS)

Karyakin, A.M.

1988-01-01

Up-to-date state of the problem of acute arterial obstruction (AAO) is considered and clinical observations of patients with acute emboli and thrombosis of abdominal aorta and main arteries of lower extremitics are analyzed. Complex of detoxication therapy and measures on controlling AAO in patients during postoperation period is presented. Complex application of hemosorption, ultraviolet irradiation of autoblood and hyperbaric oxygenation enabled to achieve correction of some indices. Reliable evidences of high therapeutic efficiency of combined application of mentioned methods to patients with reconstructed blood flow are presented. 38 refs.; 3 tabs

Interaction of Drugs in the Hyperbaric Environment, Bethesda, Maryland, 13-14 September 1979. The Undersea Medical Workshop (21st),

Science.gov (United States)

1980-10-01

activity. At the moment we would be hard- pressed to provide a definitive answer. 3. The use of "social" drugs such as alcohol or cannabis in con...innocuous drugs ASA, acetaminophen, caffeine , diphen- hydramine, dimenhydrinate, may cause significant decrements in perfor- mance at 3-7 ATA (10...pressure interactions, a few have indicated no changes in the hyperbaric envi- ronment. Animal evaluations of caffeine , theophylline, dimenhydrinate

Evaluation of spinal anesthesia blockade time with 0.5% hyperbaric bupivacaine, with or without sufentanil, in chronic opioid users: a randomized clinical trial.

Science.gov (United States)

Sadeghi, Mostafa; Yekta, Reza Atef; Azimaraghi, Omid; Barzin, Gilda; Movafegh, Ali

2016-01-01

The primary outcome of this study was to evaluate the effect of adding sufentanil to hyperbaric bupivacaine on duration of sensory blockade of spinal anesthesia in chronic opioid users in comparison with non-addicts. Sixty patients scheduled for orthopedic surgery under spinal anesthesia were allocated into four groups: group 1 (no history of opium use who received intrathecal hyperbaric bupivacaine along with 1mL saline as placebo); group 2 (no history of opium use who received intrathecal bupivacaine along with 1mL sufentanil [5μg]); group 3 (positive history of opium use who received intrathecal bupivacaine along with 1mL saline as placebo) and group 4 (positive history of opium use who received intrathecal bupivacaine along with 1mL sufentanil [5μg]). The onset time and duration of sensory and motor blockade were measured. The duration of sensory blockade in group 3 was 120±23.1min which was significantly less than other groups (G1=148±28.7, G2=144±26.4, G4=139±24.7, p=0.007). The duration of motor blockade in group 3 was 145±30.0min which was significantly less than other groups (G1=164±36.0, G2=174±26.8, G4=174±24.9, p=0.03). Addition of 5μg intrathecal sufentanil to hyperbaric bupivacaine in chronic opioid users lengthened the sensory and motor duration of blockade to be equivalent to blockade measured in non-addicts. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

Dual ionization chamber

International Nuclear Information System (INIS)

Mallory, J.; Turlej, Z.

1981-01-01

Dual ionization chambers are provided for use with an electronic smoke detector. The chambers are separated by electrically-conductive partition. A single radiation source extends through the partition into both chambers, ionizing the air in each. The mid-point current of the device may be balanced by adjusting the position of the source

The Effects of 12 Hours of Low-Grade Hypoxia at 10,000 ft at Night in Special Operations Forces Aircraft Operations on Cognition, Night Vision, Goggle Vision and Subjective Symptoms

Science.gov (United States)

2007-06-28

in scuba diving, or other hyperbaric exposures, for 48 h prior to the hypobaric exposures. Each subject was trained prior to study condition as...and another at 10,000 ft altitude in a hypobaric chamber. Half of the subjects performed moderate exercise. Results: Twelve hour exposure at 10,000...to 10,000 ft altitude pressure in a hypobaric chamber. Half (15) of the subjects performed moderate exercise on a cycle ergometer for 10 min every

Wire Chamber

CERN Multimedia

Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Wire chamber

CERN Multimedia

1967-01-01

Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Unilateral spinal anesthesia with low dose bupivacaine and ropivacaine: hypobaric or hyperbaric solutions with fentanyl for one-day surgery?

OpenAIRE

KALAGAC FABRIS, LADA; ŠAKIĆ ZDRAVČEVIĆ, KATARINA

2013-01-01

Background and Objectives: The purpose of this study was to compare the quality of unilateral spinal anesthesia with low dose bupivacaine and ropivacaine deluded in different baric solutions (hyperbaric / hypobaric). In our special interest was to define possibilities to use hypobaric solutions of local anesthetics if they prove to have any advantages. Methods: This prospective study was conduced over a 24-month period, enrolling eighty patients (ASA groups I, II, III) randomly divide...

Effects of normobaric versus hyperbaric oxygen on cell injury induced by oxygen and glucose deprivation in acute brain slices

OpenAIRE

Laurent Chazalviel; Jean-Eric Blatteau; Nicolas Vallée; Jean-Jacques Risso; Stéphane Besnard; Jacques H Abraini

2016-01-01

Normobaric oxygen (NBO) and hyperbaric oxygen (HBO) are emerging as a possible co-treatment of acute ischemic stroke. Both have been shown to reduce infarct volume, to improve neurologic outcome, to promote endogenous tissue plasminogen activator-induced thrombolysis and cerebral blood flow, and to improve tissue oxygenation through oxygen diffusion in the ischemic areas, thereby questioning the interest of HBO compared to NBO. In the present study, in order to investigate and compare the oxy...

Ionization chambers

International Nuclear Information System (INIS)

Boag, J.W.

1987-01-01

Although a variety of solid-state and chemical methods for measuring radiation dose have been developed in recent decades and calorimetry can now provide an absolute standard of reference, ionization dosimetry retains its position as the most widely used, most convenient, and, in most situations, most accurate method of measuring either exposure or absorbed dose. The ionization chamber itself is the central element in this system of dosimetry. In this chapter the principles governing the construction and operation of ionization chambers of various types are examined. Since the ionization chambers now in general use are nearly all of commercial manufacture, the emphasis is on operating characteristics and interpretation of measurements rather than on details of construction, although some knowledge of the latter is often required when applying necessary corrections to the measured quantities. Examples are given of the construction of typical chambers designed for particular purposes, and the methods of calibrating them are discussed

Hyperbaric oxygen treatment for air or gas embolism.

Science.gov (United States)

Moon, R E

2014-01-01

Gas can enter arteries (arterial gas embolism) due to alveolar-capillary disruption (caused by pulmonary overpressurization, e.g., breath-hold ascent by divers) or veins (venous gas embolism, VGE) as a result of tissue bubble formation due to decompression (diving, altitude exposure) or during certain surgical procedures where capillary hydrostatic pressure at the incision site is sub-atmospheric. Both AGE and VGE can be caused by iatrogenic gas injection. AGE usually produces strokelike manifestations, such as impaired consciousness, confusion, seizures and focal neurological deficits. Small amounts of VGE are often tolerated due to filtration by pulmonary capillaries. However, VGE can cause pulmonary edema, cardiac "vapor lock" and AGE due to transpulmonary passage or right-to-left shunt through a patent foramen ovale. Intravascular gas can cause arterial obstruction or endothelial damage and secondary vasospasm and capillary leak. Vascular gas is frequently not visible with radiographic imaging, which should not be used to exclude the diagnosis of AGE. Isolated VGE usually requires no treatment; AGE treatment is similar to decompression sickness (DCS), with first aid oxygen then hyperbaric oxygen. Although cerebral AGE (CAGE) often causes intracranial hypertension, animal studies have failed to demonstrate a benefit of induced hypocapnia. An evidence-based review of adjunctive therapies is presented.

Gas microstrip chambers

International Nuclear Information System (INIS)

McIntyre, P.M.; Barasch, E.F.; Bowcock, T.J.V.; Demroff, H.P.; Elliott, S.M.; Howe, M.R.; Lee, B.; Mazumdar, T.K.; Pang, Y.; Smith, D.D.; Wahl, J.; Wu, Y.; Yue, W.K.; Gaedke, R.M.; Vanstraelen, G.

1992-01-01

The gas microstrip chamber has been developed from concept to experimental system during the past three years. A pattern of anode and grid lines are microfabricated onto a dielectric substrate and configured as a high-resolution MWPC. Four recent developments are described: Suitable plastic substrates and lithography techniques for large-area chambers; non-planar silicon-based chambers for 20 μm resolution; integrated on-board synchronous front-end electronics and data buffering; and a porous silicon active cathode for enhanced efficiency and time response. The microstrip chamber appears to be a promising technology for applications in microvertex, tracking spectrometer, muon spectrometer, and transition radiation detection. (orig.)

Uso da oxigenoterapia hiperbárica em pacientes de um serviço de reumatologia pediátrica Hyperbaric oxygen therapy in patients of a pediatric rheumatology service

Directory of Open Access Journals (Sweden)

Juliana Figueira M. R. Rossi

2005-04-01

ça, Hospital das Clínicas, Faculty of Medicine, São Paulo University, between 1996 and 2002, were submitted to hyperbaric oxygen therapy. This therapy was indicated by the presence of chronic osteomyelitis and tissue ulcer (vasculitis or infection not responsive to the usual treatment. Two patients presented cutaneous polyarteritis, two presented chronic recurrent multifocal osteomyelitis, one presented diffuse cutaneous sclerodema and one presented pyoderma gangrenosum. Five patients were girls (age range from 6 to 13.2 years-old. The sessions of hyperbaric oxygen therapy were performed under pressures that ranged from 2.4 to 2.8 absolute atmospheres and their duration were two hours. The lowest number of sessions was 18 and the highest was 80. Five patients presented complete resolution of the injuries. The patient with cutaneous sclerodema suspended the treatment after the 18th session, because she went back to her birthplace with partial improvement of the cutaneous injuries. The main adverse event during the sessions was ear pain after the first sessions, which disappeared with reduction of the pressure inside the chamber and the duration of the session. Spandrel perforation or other adverse events were not observed. The hyperbaric oxygen therapy was efficient and well tolerated by patients with rheumatic diseases and ulcerated injuries by vasculitis, infected injuries or chronic osteomyelitis.

Non-Toxic Metabolic Management of Metastatic Cancer in VM Mice: Novel Combination of Ketogenic Diet, Ketone Supplementation, and Hyperbaric Oxygen Therapy.

Directory of Open Access Journals (Sweden)

A M Poff

Full Text Available The Warburg effect and tumor hypoxia underlie a unique cancer metabolic phenotype characterized by glucose dependency and aerobic fermentation. We previously showed that two non-toxic metabolic therapies - the ketogenic diet with concurrent hyperbaric oxygen (KD+HBOT and dietary ketone supplementation - could increase survival time in the VM-M3 mouse model of metastatic cancer. We hypothesized that combining these therapies could provide an even greater therapeutic benefit in this model. Mice receiving the combination therapy demonstrated a marked reduction in tumor growth rate and metastatic spread, and lived twice as long as control animals. To further understand the effects of these metabolic therapies, we characterized the effects of high glucose (control, low glucose (LG, ketone supplementation (βHB, hyperbaric oxygen (HBOT, or combination therapy (LG+βHB+HBOT on VM-M3 cells. Individually and combined, these metabolic therapies significantly decreased VM-M3 cell proliferation and viability. HBOT, alone or in combination with LG and βHB, increased ROS production in VM-M3 cells. This study strongly supports further investigation into this metabolic therapy as a potential non-toxic treatment for late-stage metastatic cancers.

Double chamber ion source

International Nuclear Information System (INIS)

Uman, M.F.; Winnard, J.R.; Winters, H.F.

1978-01-01

The ion source is comprised of two discharge chambers one of which is provided with a filament and an aperture leading into the other chamber which in turn has an extraction orifice. A low voltage arc discharge is operated in an inert gas atmosphere in the filament chamber while an arc of higher voltage is operated in the second ionization chamber which contains a vapor which will give the desired dopant ion species. The entire source is immersed in an axial magnetic field parallel to a line connecting the filament, the aperture between the two chambers and the extraction orifice. (author)

Ussing Chamber

NARCIS (Netherlands)

Westerhout, J.; Wortelboer, H.; Verhoeckx, K.

2015-01-01

The Ussing chamber system is named after the Danish zoologist Hans Ussing, who invented the device in the 1950s to measure the short-circuit current as an indicator of net ion transport taking place across frog skin (Ussing and Zerahn, Acta Physiol Scand 23:110-127, 1951). Ussing chambers are

DELPHI Barrel Muon Chamber Module

CERN Multimedia

1989-01-01

The module was used as part of the muon identification system on the barrel of the DELPHI detector at LEP, and was in active use from 1989 to 2000. The module consists of 7 individual muons chambers arranged in 2 layers. Chambers in the upper layer are staggered by half a chamber width with respect to the lower layer. Each individual chamber is a drift chamber consisting of an anode wire, 47 microns in diameter, and a wrapped copper delay line. Each chamber provided 3 signal for each muon passing through the chamber, from which a 3D space-point could be reconstructed.

Gridded ionization chamber

International Nuclear Information System (INIS)

Houston, J.M.

1977-01-01

An improved ionization chamber type x-ray detector comprises a heavy gas at high pressure disposed between an anode and a cathode. An open grid structure is disposed adjacent the anode and is maintained at a voltsge intermediate between the cathode and anode potentials. The electric field which is produced by positive ions drifting toward the cathode is thus shielded from the anode. Current measuring circuits connected to the anode are, therefore, responsive only to electron current flow within the chamber and the recovery time of the chamber is shortened. The grid structure also serves to shield the anode from electrical currents which might otherwise be induced by mechanical vibrations in the ionization chamber structure

HYPERBARIC OXYGENT HERAPY AND CANCER - A REVIEW.

Directory of Open Access Journals (Sweden)

I. Moen

2015-01-01

Full Text Available Hypoxia is a critical hallmark of solid tumors and involves enhanced cell survival, angiogenesis, glycolytic metabolism, andmetastasis. Hyperbaric oxygen (HBO treatment has for centuries been used to improve or cure disorders involving hypoxia and ischemia, by enhancing the amount of dissolved oxygen in the plasma and thereby increasing О2 delivery to the tissue. Studies on HBO and cancer have up to recently focused on whether enhanced oxygen acts as a cancer promoter or not. As oxygen is believed to be required for all the major processes of wound healing, one feared that the effects of HBO would be applicable to cancer tissue as well and promote cancer growth. Furthermore, one also feared that exposing patients who had been treated for cancer, to HBO, would lead to recurrence. Nevertheless, two systematic reviews on HBO and cancer have concluded that the use of HBO in patients with malignancies is considered safe. To supplement the previous reviews, we have summarized the work performed on HBO and cancer in the period 2004–2012. Based on the present as well as previous reviews, there is no evidence indicating that HBO neither acts as a stimulator of tumor growth nor as an enhancer of recurrence. On the other hand, there is evidence that implies that HBO might have tumor-inhibitory effects in certain cancer subtypes, and we thus strongly believe that we need to expand our knowledge on the effect and the mechanisms behind tumor oxygenation.

Treatment of Laryngeal Radionecrosis with Hyperbaric Oxygen Therapy: A Case Report

Directory of Open Access Journals (Sweden)

Ying-Che Hsu

2005-02-01

Full Text Available An 81-year-old male with early-stage laryngeal carcinoma had been treated with 60 Gy curative radiotherapy. He complained of a sore throat, foul odor in the mouth, progressive dyspnea, and fever 2 months after the completion of radiotherapy. Direct laryngoscopy revealed narrowing of the glottis with diffuse ulcerative necrotic tissue. Biopsies at multiple sites and pathology revealed intense coagulation necrosis with complete denudation of covering epithelium without any malignancy. Since laryngeal radionecrosis was suspected, the patient received hyperbaric oxygen (HBO therapy 40 times for 1 hour of 100% O2 at 2 atm absolute pressure. His clinical symptoms gradually improved and repeated endolaryngeal biopsies were undertaken near the end of HBO therapy and again 6 months later. The patient's larynx healed completely with diffuse fibrosis and no malignant cells were found on pathology. Radionecrosis must be differentiated from cancer recurrence following curative radiotherapy for early laryngeal cancer. HBO therapy could be a useful treatment adjunct for laryngeal radionecrosis.

Confecção de um modelo experimental in vitro do espaço subaracnóide eqüino para teste de opióides hiperbáricos Making of an in vitro experimental model of equine subarachnoid space to test hyperbaric opioids

Directory of Open Access Journals (Sweden)

Alexandre da Silva Polydoro

2008-04-01

Full Text Available Com o objetivo de avaliar as características de distribuição de agentes hiperbáricos no líquido cérebro-espinhal (LCE eqüino, é apresentado um modelo in vitro do espaço subaracnóide confeccionado em policloreto de vinila (PVC transparente, no qual se adaptou um cateter para a infusão contínua de glicose a 10%, morfina hiperbárica, buprenorfina hiperbárica e metadona hiperbárica marcadas com azul de metileno para permitir a visualização da distribuição destas substâncias no LCE. Avaliaram-se a distância alcançada pelos diferentes agentes minuto a minuto e a forma de distribuição dos mesmos. Todas as substâncias testadas mostraram comportamento de distribuição vertical a partir da extremidade do cateter, quando se deu o início da migração cranial no LCE, sendo que o avanço máximo registrado foi aos 15 minutos após o término da infusão, com migração de 15cm para glicose a 10%, 13cm para a morfina hiperbárica, 18cm para a buprenorfina hiperbárica e 17cm para a metadona hiperbárica. O modelo proposto mostrou-se eficiente para a avaliação do comportamento físico dos agentes hiperbáricos no interior do espaço subaracnóide, oferecendo a possibilidade de teste de substâncias a serem utilizadas pela via subaracnóide de cavalos.The aim of this study was to evaluate the distribution characteristics of hyperbaric solutions in equine cerebrospinal fluid (CSF, in an in vitro model of the subarachnoid space. The model was made with transparent PVC in which a catheter was adapted to infuse 10% glucose, 10% hyperbaric morphine, hyperbaric buprenorphine, and hyperbaric methadone, dyed with methilene blue in order to visualize the solutions distribution in the CSF. The distance in cm reached by the different agents every minute as well as the pattern of distribution were evaluated. All tested solutions distributed itself in a forward and vertically pattern from the tip of the catheter. Maximum distance reached after

Neuroprotection of hyperbaric oxygen therapy in sub-acute traumatic brain injury: not by immediately improving cerebral oxygen saturation and oxygen partial pressure.

Science.gov (United States)

Zhou, Bao-Chun; Liu, Li-Jun; Liu, Bing

2016-09-01

Although hyperbaric oxygen (HBO) therapy can promote the recovery of neural function in patients who have suffered traumatic brain injury (TBI), the underlying mechanism is unclear. We hypothesized that hyperbaric oxygen treatment plays a neuroprotective role in TBI by increasing regional transcranial oxygen saturation (rSO 2 ) and oxygen partial pressure (PaO 2 ). To test this idea, we compared two groups: a control group with 20 healthy people and a treatment group with 40 TBI patients. The 40 patients were given 100% oxygen of HBO for 90 minutes. Changes in rSO 2 were measured. The controls were also examined for rSO 2 and PaO 2 , but received no treatment. rSO 2 levels in the patients did not differ significantly after treatment, but levels before and after treatment were significantly lower than those in the control group. PaO 2 levels were significantly decreased after the 30-minute HBO treatment. Our findings suggest that there is a disorder of oxygen metabolism in patients with sub-acute TBI. HBO does not immediately affect cerebral oxygen metabolism, and the underlying mechanism still needs to be studied in depth.

Electromagnetic reverberation chambers

CERN Document Server

Besnier, Philippe

2013-01-01

Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

Dorsal skinfold chamber models in mice

Directory of Open Access Journals (Sweden)

Schreiter, Jeannine

2017-07-01

Full Text Available Background/purpose: The use of dorsal skinfold chamber models has substantially improved the understanding of micro-vascularisation in pathophysiology over the last eight decades. It allows pathophysiological studies of vascularisation over a continuous period of time. The dorsal skinfold chamber is an attractive technique for monitoring the vascularisation of autologous or allogenic transplants, wound healing, tumorigenesis and compatibility of biomaterial implants. To further reduce the animals’ discomfort while carrying the dorsal skinfold chamber, we developed a smaller chamber (the Leipzig Dorsal Skinfold Chamber and summarized the commercial available chamber models. In addition we compared our model to the common chamber. Methods: The Leipzig Dorsal Skinfold Chamber was applied to female mice with a mean weight of 22 g. Angiogenesis within the dorsal skinfold chamber was evaluated after injection of fluorescein isothiocyanate dextran with an Axio Scope microscope. The mean vessel density within the dorsal skinfold chamber was assessed over a period of 21 days at five different time points. The gained data were compared to previous results using a bigger and heavier dorsal skinfold model in mice. A PubMed and a patent search were performed and all papers related to “dorsal skinfold chamber” from 1 of January 2006 to 31 of December 2015 were evaluated regarding the dorsal skinfold chamber models and their technical improvements. The main models are described and compared to our titanium Leipzig Dorsal Skinfold Chamber model.Results: The Leipzig Dorsal Skinfold Chamber fulfils all requirements of continuous models known from previous chamber models while reducing irritation to the mice. Five different chamber models have been identified showing substantial regional diversity. The newly elaborated titanium dorsal skinfold chamber may replace the pre-existing titanium chamber model used in Germany so far, as it is smaller and lighter

A combination drift chamber/pad chamber for very high readout rates

International Nuclear Information System (INIS)

Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W.; Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J.; Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P.; Arenton, M.; Conetti, S.; Cox, B.; Dukes, E.; Golovatyuk, V.; Hanlet, P.; McManus, A.; Nelson, K.; Recagni, M.; Segal, J.; Sun, J.; Ballagh, C.; Bingham, H.; Kaeding, T.; Lys, J.; Misawa, S.; Blankman, A.; Borodin, S.; Kononenko, W.; Newcomer, M.; Selove, W.; Trojak, T.; VanBerg, R.; Zhang, S.N.; Block, M.; Corti, G.; LeCompte, T.; Rosen, J.; Yao, T.; Boden, A.; Cline, D.; Ramachandran, S.; Rhoades, J.; Tokar, S.; Budagov, J.; Tsyganov, E.; Cao, Z.L.; He, M.; Wang, C.; Wei, C.; Zhang, N.; Chen, T.Y.; Yao, N.; Clark, K.; Jenkins, M.; Cooper, M.; Creti, P.; Gorini, E.; Grancagnolo, F.; Panareo, M.; Fortney, L.; Kowald, W.; Haire, M.; Judd, D.; Turnbull, L.; Wagoner, D.; Lau, K.; Mo, G.; Trischuk, J.

1991-11-01

Six medium-sized (∼1 x 2 m 2 ) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers

A combination drift chamber/pad chamber for very high readout rates

Energy Technology Data Exchange (ETDEWEB)

Spiegel, L.; Cataldi, G.; Elia, V.; Mazur, P.; Murphy, C.T.; Smith, R.P.; Yang, W. (Fermi National Accelerator Lab., Batavia, IL (United States)); Alexopoulos, T.; Durandet, C.; Erwin, A.; Jennings, J. (Wisconsin Univ., Madison, WI (United States)); Antoniazzi, L.; Introzzi, G.; Lanza, A.; Liguori, G.; Torre, P. (Pavia Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Rome (Italy)); Arenton, M.; Conetti, S.

1991-11-01

Six medium-sized ({approx}1 {times} 2 m{sup 2}) drift chambers with pad and stripe readout have been constructed for and are presently operating in Fermi National Accelerator Laboratory experiment E-771. Each chamber module actually represents a pair of identical planes: two sets of anode wires, two sets of stripes, and two sets of pads. The wire planes are read out separately and represent X measurements in the coordinate system of the experiment. The twin stripe and pad planes are internally paired within the chamber modules; stripe signals represent Y measurements and pad signals combination X and Y measurements. Signals which develop on the stripes and pads are mirror (but inverted) images of what is seen on the wires. In addition to being used in the off-line pattern recognition, pad signals are also used as inputs to an on-line high transverse momentum (pt) trigger processor. While the techniques involved in the design and construction of the chambers are not novel, they may be of interest to experiments contemplating very large area, high rate chambers for future spectrometers.

Sequential Use of Hyperbaric Oxygen, Synthetic Skin Substitute and Skin Grafting in the Treatment of a Refractory Vasculitic Ulcer.

Science.gov (United States)

Akcali, Gökhan; Uzun, Günalp; Yapici, Abdül Kerim; Yildiz, Şenol

2013-12-01

Cutaneous leukocytoclastic vasculitis (CLCV) is a disorder characterized by the inflammation of the small vessels of the skin. CLCV may cause recurrent, drug-resistant, non-healing ulcers. Herein, we present a patient with a recalcitrant ulcer caused by CLCV, who was successfully treated with hyperbaric oxygen therapy and skin grafting. There is not any particular therapy/product that will heal all type of wounds. We can achieve better results provided that wound care products and advanced treatments are used at the right time.

The use of hyperbaric oxygen therapy and LED therapy in diabetic foot

Science.gov (United States)

Marques, Cristiane R. S.; Martin, Airton A.; Lima, Carlos J.; Conrado, Luis A. L.; Silveira, Fabricio L.; Carvalho, Marcos V.

2004-07-01

Chronic foot ulcers are common ailments presented in diabetes, which offer severe complications and are often unresponsive to therapy. In this work it was evaluated the effects of adjunctive Hyperbaric Oxygen Therapy (HBO) treatment and LEDtherapy irradiation on ulcer healing (HBO) in addition to conventional treatment. In ulcers of diabetic foot these treatments lead to a reduction in the probability of amputation up to almost four times compared with patients not receiving such co-adjutant treatment. The LEDtherapy irradiation was given concurrently using an energy density of 4J/cm2 for 5 min. During the experiment nine patients with diabetic foot ulcers were submitted for HBO sessions with 2,5 ATM for two hours. The experiment demonstrated the effectiveness of HBO + LEDtherapy treatment by favoring the ulcer healing through an increased fibroblastic response, collagen synthesis and neo-vascularization of the ischaemia, as well as increases in the leukocytic bactericidal activity.

Quantitative Romberg's test in acute carbon monoxide poisoning treated by hyperbaric oxygen

DEFF Research Database (Denmark)

Bidstrup, Daniel; Jansen, Erik Christian; Hyldegaard, Ole

2017-01-01

LMM, sway prior to HBO₂ therapy was set as the fixed effect and change in sway after HBO₂ therapy was set as the response variable. Patient, treatment number, weight and age were set as random effects for all LMMs. RESULTS: From the LMMs we found that larger values of sway prior to HBO₂ produced......OBJECTIVE: The aim of this study was to evaluate whether monitoring of acute carbon monoxide-poisoned (COP) patients by means of quantitative Romberg's test (QR-test) during a hyperbaric oxygen (HBO₂) therapy regimen could be a useful supplement in the evaluation of neurological status. METHODS: We...... conducted a retrospective study (2000-2014) in which we evaluated data containing quantitative sway measurements of acute COP patients (n = 58) treated in an HBO₂ regimen. Each patient was tested using QR-test before and after each HBO₂ treatment. Data were analyzed using linear mixed models (LMM). In each...

Review of wire chamber aging

International Nuclear Information System (INIS)

Va'Vra, J.

1986-02-01

This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

Effects of Hyperbaric Oxygen Treatment on Renal System.

Science.gov (United States)

Tezcan, Orhan; Caliskan, Ahmet; Demirtas, Sinan; Yavuz, Celal; Kuyumcu, Mahir; Nergiz, Yusuf; Guzel, Abdulmenap; Karahan, Oguz; Ari, Seyhmus; Soker, Sevda; Yalinkilic, Ibrahim; Turkdogan, Kenan Ahmet

2017-01-01

Hyperbaric oxygen (HBO) treatment is steadily increasing as a therapeutic modality for various types of diseases. Although good clinical outcomes were reported with HBO treatment for various diseases, the multisystemic effects of this modality are still unclear. This study aimed to investigate the renal effects of HBO experimentally. Fourteen New Zealand White rabbits were divided into 2 groups randomly as the control group and the study group. The study group received HBO treatment for 28 days (100% oxygen at 2.5 atmospheres for 90 minutes daily) and the control group was used to obtain normal renal tissue of the animal genus. After the intervention period, venous blood samples were obtained, and renal tissue samples were harvested for comparisons. Normal histological morphology was determined with Masson trichrome staining and periodic acid-Schiff staining in the control group. Atrophic glomerular structures, vacuolated tubule cells, and degeneration were detected in the renal samples of the study group with Masson trichrome staining. Additionally, flattening was observed on the brush borders of the proximal tubules, and tubular dilatation was visualized with periodic acid-Schiff staining. The histopathologic disruption of renal morphology was verified with detection of significantly elevated kidney function laboratory biomarkers in the study group. Our findings suggests that HBO has adverse effects on renal glomerulus and proximal tubules. However, the functional effects of this alteration should be investigated with further studies.

Effect of hyperbaric oxygen therapy on whole blood cyanide concentrations in carbon monoxide intoxicated patients from fire accidents

DEFF Research Database (Denmark)

Lawson-Smith, Pia; Jansen, Erik C; Hilsted, Linda

2010-01-01

Hydrogen cyanide (HCN) and carbon monoxide (CO) may be important components of smoke from fire accidents. Accordingly, patients admitted to hospital from fire accidents may have been exposed to both HCN and CO. Cyanide (CN) intoxication results in cytotoxic hypoxia leading to organ dysfunction...... and possibly death. While several reports support the use of hyperbaric oxygen therapy (HBO) for the treatment of severe CO poisoning, limited data exist on the effect of HBO during CN poisoning. HBO increases the elimination rate of CO haemoglobin in proportion to the increased oxygen partial pressure...

Change of Pressing Chamber Conicalness at Briquetting Process in Briquetting Machine Pressing Chamber

Directory of Open Access Journals (Sweden)

Peter Križan

2012-01-01

Full Text Available In this paper, we will present the impact of the conical shape of a pressing chamber, an important structural parameter. Besides the known impact of the technological parameters of pressing chambers, it is also very important to pay attention to their structural parameters. In the introduction, we present a theoretical analysis of pressing chamber conicalness. An experiment aimed at detecting this impact was performed at our institute, and it showed that increasing the conicalness of a pressing chamber improves the quality of the final briquettes. The conicalness of the pressing chamber has a significanteffect on the final briquette quality and on the construction of briquetting machines. The experimental findings presented here show the importance of this parameter in the briquetting process.

Effects of the addition of subarachnoid clonidine to the anesthetic solution of sufentanil and hyperbaric or hypobaric bupivacaine for labor analgesia.

Science.gov (United States)

Tebaldi, Thaís Cristina; Malbouisson, Luíz Marcelo Sá; Kondo, Mario M; Cardoso, Mônica M S C

2008-01-01

The addition of subarachnoid clonidine (alpha-agonist) prolongs the analgesia produced by the combination of sufentanil and isobaric bupivacaine in combined labor analgesia(1). The objective of this study was to compare the quality of analgesia and the prevalence of side effects after the addition of subarachnoid clonidine to the anesthetic solution in labor analgesia. After approval by the Ethics Commission, 22 pregnant women in labor were randomly assigned to the subarachnoid administration of either 2.5 mg of 0.5% hyperbaric bupivacaine (CLON/HYPER Group; n = 11) or 2.5 mg of 0.5% isobaric bupivacaine (CLON/ISO Group; n = 11) associated with 2.5 microg of sufentanil and 30 microg of clonidine. Pain, evaluated by the Visual Analogue Scale, heart rate, and mean arterial pressure were assessed every 5 minutes during the first 15 minutes, and then every 15 minutes afterwards until delivery. The prevalence of side effects (nausea, vomiting, pruritus, and sedation) was evaluated. The study was terminated whenever the patient needed supplemental epidural analgesia (pain > 3) or upon delivery of the fetus. The Student t test, Chi-square test, Fisher exact test, and two-way ANOVA for repeated measurements were used in the statistical analysis and a p hyperbaric and isobaric solutions showed similar behavior.

Effects of Exercise Training under Hyperbaric Oxygen on Oxidative Stress Markers and Endurance Performance in Young Soccer Players: A Pilot Study

Directory of Open Access Journals (Sweden)

Carlos Burgos

2016-01-01

Full Text Available The aim of the present study was to determine the effects of three weeks of hyperbaric oxygen (HBO2 training on oxidative stress markers and endurance performance in young soccer players. Participants (18.6±1.6 years were randomized into hyperbaric-hyperoxic (HH training (n=6 and normobaric normoxic (NN training (n=6 groups. Immediately before and after the 5th, 10th, and 15th training sessions, plasma oxidative stress markers (lipid hydroperoxides and uric acid, plasma antioxidant capacity (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid [TROLOX], arterial blood gases, acid-base balance, bases excess (BE, and blood lactate analyses were performed. Before and after intervention, maximal oxygen uptake (VO2max and peak power output (PPO were determined. Neither HH nor NN experienced significant changes on oxidative stress markers or antioxidant capacity during intervention. VO2max and PPO were improved (moderate effect size after HH training. The results suggest that HBO2 endurance training does not increase oxidative stress markers and improves endurance performance in young soccer players. Our findings warrant future investigation to corroborate that HBO2 endurance training could be a potential training approach for highly competitive young soccer players.

Sleeve reaction chamber system

Science.gov (United States)

Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

2009-08-25

A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

Dual-chamber inflatable oil boom

International Nuclear Information System (INIS)

Blair, R.M.; Tedeschi, E.T.

1993-01-01

An elongated floating material containment boom section is described having a normally vertical ballasted skirt depending from flotation means, and convertible from a flattened collapsed condition to a deployable condition wherein buoyancy chamber means extending along the upper edge of said skirt are inflated to expanded buoyant configuration, including: a gas-impervious sleeve extending along the upper edge of said normally vertical skirt forming a first outer collapsible and inflatable flotation chamber, a first inflation valve connecting the interior of said sleeve with the ambient atmosphere, through which gas under pressure may be introduced into said sleeve to inflate said first buoyant outer flotation chamber, elongated gas-impervious tube means positioned inside said outer flotation chamber and forming second collapsible and inflatable internal flotation bladder chamber means, second inflation valve means connecting the interior of said bladder means through said outer flotation chamber to the ambient atmosphere through which gas under pressure may be introduced into said bladder means to inflate it forming said second flotation chamber means inside said outer flotation chamber

Noise exposure under hyperbaric conditions

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

Objective evidence exists that divers demonstrate a hearing deficit greater than would be expected from ageing effects alone. Deafness in divers may be caused by a number of factors other than exposure to excessive noise levels, eg barotrauma, ear infection etc. This review concentrates on the concern that exposure of commercial divers to noise while at work may cause a hearing deficit. Sound pressure levels recorded both underwater and in diving chambers often exceed those allowable to workers onshore. However, the sound perceived by the diver is modified both in amplitude and in frequency when he is either underwater or in pressurised chambers. Broadly the effect of this modification is to attenuate the sound and thus offer some protection from high noise levels. The degree of attentuation varies with the frequency of the sound, however it is also possible under specific conditions associated with gas density for the sensitivity to particular frequencies to be amplified above that for normal atmospheric air. The levels of sound observed from some underwater tools are of concern even after allowing for a significant de-sensitisation of the divers` hearing. Reports of tinnitus and temporary hearing loss following a dive are sure signs that the noise levels have been harmful. It is not possible at present to describe risk criteria for hearing damage due to noise exposure associated with diving. (author)

BEBC bubble chamber

CERN Multimedia

CERN PhotoLab

1972-01-01

Looking up into the interior of BEBC bubble chamber from the expansion cylinder. At the top of the chamber two fish-eye lenses are installed and three other fish-eye ports are blanked off. In the centre is a heat exchanger.

Climatic chamber ergometer

CSIR Research Space (South Africa)

Atkins, AR

1968-01-01

Full Text Available The design and calibration of an ergometer for exercising subjects during calorimetric studies in the climate chamber, are described. The ergometer is built into the climatic chamber and forms an integral part of the whole instrumentation system foe...

Is there a role for hyperbaric oxygen as primary treatment for grade IV radiation-induced haemorrhagic cystitis? a prospective pilot-feasibility study and review of literature

Energy Technology Data Exchange (ETDEWEB)

Dellis, Athanasios [Surgical Department, University of Athens, Aretaieion Hospital (Greece); Deliveliotis, Charalambos [Urologic Department, University of Athens, Sismanoglio General Hospital (Greece); Kalentzos, Vasileios; Vavasis, Pavlos; Skolarikos, Andreas [Diving and Hyperbaric Oxygen Department, Naval and Veterans Hospital, Athens (Greece)

2014-05-15

Purpose: To examine the safety and efficacy of hyperbaric oxygen as the primary treatment for Grade IV radiation-induced haemorrhagic cystitis. Materials and Methods: Hyperbaric oxygen was prospectively applied as a primary treatment option in 11 patients with Grade IV radiation cystitis. Primary endpoint was the incidence of complete and partial response to treatment. Secondary endpoints included the duration of response, the correlation of treatment success-rate to the interval between the onset of haematuria and initiation of therapy, blood transfusion need and total radiation dose, the number of sessions to success, the avoidance of surgery and the overall survival. Results: All patients completed therapy without complications for a mean follow-up of 17.82 months (range 3 to 34). Mean number of sessions needed was 32.8 (range 27 to 44). Complete and partial response rate was 81.8% and 18.2%, respectively. However, in three patients the first treatment session was not either sufficient or durable giving a 72.7% rate of durable effect. Interestingly, all 9 patients with complete response received therapy within 6 months of the haematuria onset compared to the two patients with partial response who received therapy at 8 and 10 months from the haematuria onset, respectively (p = 0.018). The need for blood transfusion (p = 0.491) and the total radiation dose (p = 0.259) were not correlated to success-rate. One patient needed cystectomy, while all patients were alive at the end of follow-up. Conclusions: Early primary use of hyperbaric oxygen to treat radiation-induced grade IV cystitis is an effective and safe treatment option. (author)

Is there a role for hyperbaric oxygen as primary treatment for grade IV radiation-induced haemorrhagic cystitis? a prospective pilot-feasibility study and review of literature

International Nuclear Information System (INIS)

Dellis, Athanasios; Deliveliotis, Charalambos; Kalentzos, Vasileios; Vavasis, Pavlos; Skolarikos, Andreas

2014-01-01

Purpose: To examine the safety and efficacy of hyperbaric oxygen as the primary treatment for Grade IV radiation-induced haemorrhagic cystitis. Materials and Methods: Hyperbaric oxygen was prospectively applied as a primary treatment option in 11 patients with Grade IV radiation cystitis. Primary endpoint was the incidence of complete and partial response to treatment. Secondary endpoints included the duration of response, the correlation of treatment success-rate to the interval between the onset of haematuria and initiation of therapy, blood transfusion need and total radiation dose, the number of sessions to success, the avoidance of surgery and the overall survival. Results: All patients completed therapy without complications for a mean follow-up of 17.82 months (range 3 to 34). Mean number of sessions needed was 32.8 (range 27 to 44). Complete and partial response rate was 81.8% and 18.2%, respectively. However, in three patients the first treatment session was not either sufficient or durable giving a 72.7% rate of durable effect. Interestingly, all 9 patients with complete response received therapy within 6 months of the haematuria onset compared to the two patients with partial response who received therapy at 8 and 10 months from the haematuria onset, respectively (p = 0.018). The need for blood transfusion (p = 0.491) and the total radiation dose (p = 0.259) were not correlated to success-rate. One patient needed cystectomy, while all patients were alive at the end of follow-up. Conclusions: Early primary use of hyperbaric oxygen to treat radiation-induced grade IV cystitis is an effective and safe treatment option. (author)

Vacuum Chambers for LEP sections

CERN Multimedia

1983-01-01

The picture shows sections of the LEP vacuum chambers to be installed in the dipole magnets (left) and in the quadrupoles (right). The dipole chamber has three channels: the beam chamber, the pumping duct where the NEG (non-evaporabe getter) is installed and the water channel for cooling (on top in the picture). The pumping duct is connected to the beam chamber through holes in the separating wall. The thick lead lining to shield radiation can also be seen. These chambers were manufactured as extruded aluminium alloy profiles.

Reference ionization chamber

International Nuclear Information System (INIS)

Golnik, N.; Zielczynski, M.

1999-01-01

The paper presents the design of ionization chamber devoted for the determination of the absolute value of the absorbed dose in tissue-equivalent material. The special attention was paid to ensure that the volume of the active gas cavity was constant and well known. A specific property of the chamber design is that the voltage insulators are 'invisible' from any point of the active volume. Such configuration ensures a very good time stability of the electrical field and defines the active volume. The active volume of the chamber was determined with accuracy of 0.3%. This resulted in accuracy of 0.8% in determination of the absorbed dose in the layer of material adherent to the gas cavity. The chamber was applied for calibration purposes at radiotherapy facility in Joint Institute for Nuclear Research in Dubna (Russia) and in the calibration laboratory of the Institute of Atomic Energy in Swierk. (author)

Plastic flashtube chambers

International Nuclear Information System (INIS)

Frisken, W.R.

1977-01-01

A brief discussion is given of the use and operation of plastic flashtube chambers. Gas leaks, electric pulsing, the glow discharge, and readout methods are considered. Three distinct problems with high rate applications deal with resolving time, dead time, and polarization/neutralization of the chamber

Wire chambers: Trends and alternatives

Energy Technology Data Exchange (ETDEWEB)

Regler, Meinhard

1992-05-15

The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

Hyperbaric oxygen treatment in three cases of necrotizing infection of the neck

Directory of Open Access Journals (Sweden)

Torbjørn Nedrebø

2012-02-01

Full Text Available Necrotizing infections of the head and neck are rare conditions in our hospital. Clinical and microbiological characteristics of three consecutive cases treated in Haukeland University Hospital in western Norway in the year 2010 are described. Two cases of Lemierre’s syndrome and one case with a descending necrotizing mediastinitis (DNM were diagnosed. All three cases were treated with broad spectrum antibiotics and in two cases surgery was possible. Hyperbaric oxygen treatment (HBOT with intensive care facilities became recently available at our hospital, and this treatment was used in all these patients regardless of surgery. In one case we describe the use of HBOT on the basis of strong clinical suspicion of anaerobic infection only. Bacterial identification by partial sequencing of the 16SrDNA gene proved to be a useful supplement to conventional culture techniques. All the cases all demonstrated a significant clinical improvement after introduction of HBOT. When HBOT is available, it should be considered as adjunctive treatment in extensive infections with anaerobes.

Regional CBF in chronic stable TBI treated with hyperbaric oxygen.

Science.gov (United States)

Barrett, K F; Masel, B; Patterson, J; Scheibel, R S; Corson, K P; Mader, J T

2004-01-01

To investigate whether Hyperbaric Oxygen Therapy (HBO2) could improve neurologic deficits and regional cerebral blood flow (rCBF) in chronic traumatic brain injuries (TBI), the authors employed a nonrandomized control pilot trial. Five subjects, at least three years post head injury, received HBO2. Five head injured controls (HIC) were matched for age, sex, and type of injury. Five healthy subjects served as normal controls. Sixty-eight normal volunteers comprised a reference data bank against which to compare SPECT brain scans. HBO2 subjects received 120 HBO2 in blocks of 80 and 40 treatments with an interval five-month break. Normal controls underwent a single SPECT brain scan, HBO2, and repeat SPECT battery. TBI subjects were evaluated by neurologic, neuropsychometric, exercise testing, and pre and post study MRIs, or CT scans if MRI was contraindicated. Statistical Parametric Mapping was applied to SPECT scans for rCBF analysis. There were no significant objective changes in neurologic, neuropsychometric, exercise testing, MRIs, or rCBF. In this small pilot study, HBO2 did not effect clinical or regional cerebral blood flow improvement in TBI subjects.

Prototype multiwire proportional chamber

CERN Multimedia

1975-01-01

Chambers of this type were initially developed within the Alpha project (finally not approved). They were designed such to minimize the radiation length with a view to a mass spectrometer of high resolution meant to replace the Omega detector. The chambers were clearly forerunners for the (drift) chambers later built for R606 with the novel technique of crimping the wires. See also photo 7510039X.

Miniature ionization chamber

International Nuclear Information System (INIS)

Alexeev, V.I.; Emelyanov, I.Y.; Ivanov, V.M.; Konstantinov, L.V.; Lysikov, B.V.; Postnikov, V.V.; Rybakov, J.V.

1976-01-01

A miniature ionization chamber having a gas-filled housing which accommodates a guard electrode made in the form of a hollow perforated cylinder is described. The cylinder is electrically associated with the intermediate coaxial conductor of a triaxial cable used as the lead-in of the ionization chamber. The gas-filled housing of the ionization chamber also accommodates a collecting electrode shaped as a rod electrically connected to the center conductor of the cable and to tubular members. The rod is disposed internally of the guard electrode and is electrically connected, by means of jumpers passing through the holes in the guard electrode, to the tubular members. The tubular members embrace the guard electrode and are spaced a certain distance apart along its entire length. Arranged intermediate of these tubular members are spacers secured to the guard electrode and fixing the collecting electrode throughout its length with respect to the housing of the ionization chamber

Wire chambers: Trends and alternatives

International Nuclear Information System (INIS)

Regler, Meinhard

1992-01-01

The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

Effects of edaravone combined with hyperbaric oxygen on cerebral vascular dynamics, oxidative stress products and inflammatory factors in patients with acute cerebral hemorrhage

Directory of Open Access Journals (Sweden)

Xia Li

2017-10-01

Full Text Available Objective: To investigate the effect of edaravone combined with hyperbaric oxygen therapy on cerebral vasculature, oxidative stress and inflammatory cytokines in patients with acute cerebral hemorrhage (ACH. Methods: A total of 96 patients with ACH were divided into control group (n=48 and observation group (n=48 according to the random number table. Both groups were treated routinely. On this basis, the control group was treated with edaravone injection, and the observation group was treated with edaravone injection combined with hyperbaric oxygen therapy. The change of cerebrovascular dynamics, oxidative stress products and inflammatory factors were examined in all subjects before and after treatment. Results: There were no significant differences in cerebrovascular function between the two groups before treatment. After treatment, the levels of Vmean and Qmean in both groups were significantly higher than those before treatment. The levels of Vmean and Qmean in the observation group were higher than those of the control group after treatment. There was no significant difference in serum oxidative stress between the two groups before treatment. After treatment, the levels of SOD in two groups were significantly higher than those before treatment. The level of SOD in the observation group was higher than that in the control group after treatment. After treatment, the levels of MDA in the two groups were significantly lower than that before treatment. The level of MDA in the observation group was lower than that of the control group after treatment. There were no significant differences in the level of serum inflammatory factors between the two groups before treatment. After treatment, the level of TNF-α and IL-1β in two groups were significantly lower than before treatment. The level of TNF-α and IL-1β in the observation group was lower than those of the control group after treatment. Conclusion: Edaravone combined with hyperbaric oxygen

A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

Science.gov (United States)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2015-11-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

Science.gov (United States)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2016-03-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

Directed Energy Anechoic Chamber

Data.gov (United States)

Federal Laboratory Consortium — The Directed Energy Anechoic Chamber comprises a power anechoic chamber and one transverse electromagnetic cell for characterizing radiofrequency (RF) responses of...

Streamer chamber: pion decay

CERN Multimedia

1992-01-01

The real particles produced in the decay of a positive pion can be seen in this image from a streamer chamber. Streamer chambers consist of a gas chamber through which a strong pulsed electric field is passed, creating sparks as a charged particle passes through it. A magnetic field is added to cause the decay products to follow curved paths so that their charge and momentum can be measured.

PS wire chamber

CERN Multimedia

1970-01-01

A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Directional muon jet chamber for a muon collider (Groovy Chamber)

International Nuclear Information System (INIS)

Atac, M.

1996-10-01

A directional jet drift chamber with PAD readout is proposed here which can select vertex originated muons within a given time window and eliminate those muons which primarily originate upstream, using only a PAD readout. Drift time provides the Z-coordinate, and the center of gravity of charge distribution provides the r-ψ coordinates. Directionality at the trigger level is obtained by the timing measurement from the PAD hits within a given time window. Because of the long drift time between the bunch crossings, a muon collider enables one to choose a drift distance in the drift chamber as long as 50 cm. This is an important factor in reducing cost of drift chambers which have to cover relatively large areas

Pencil-shaped radiation detection ionization chamber

International Nuclear Information System (INIS)

Suzuki, A.

1979-01-01

A radiation detection ionization chamber is described. It consists of an elongated cylindrical pencil-shaped tubing forming an outer wall of the chamber and a center electrode disposed along the major axis of the tubing. The length of the chamber is substantially greater than the diameter. A cable connecting portion at one end of the chamber is provided for connecting the chamber to a triaxial cable. An end support portion is connected at the other end of the chamber for supporting and tensioning the center electrode. 17 claims

Attenuating brain edema, hippocampal oxidative stress, and cognitive dysfunction in rats using hyperbaric oxygen preconditioning during simulated high-altitude exposure.

Science.gov (United States)

Lin, Hung; Chang, Ching-Ping; Lin, Hung-Jung; Lin, Mao-Tsun; Tsai, Cheng-Chia

2012-05-01

We assessed whether hyperbaric oxygen preconditioning (HBO2P) in rats induced heat shock protein (HSP)-70 and whether HSP-70 antibody (Ab) preconditioning attenuates high altitude exposure (HAE)-induced brain edema, hippocampal oxidative stress, and cognitive dysfunction. Rats were randomly divided into five groups: the non-HBO2P + non-HAE group, the HBO2P + non-HAE group, the non-HBO2P + HAE group, the HBO2P + HAE group, and the HBO2P + HSP-70 Abs + HAE group. The HBO2P groups were given 100% O2 at 2.0 absolute atmospheres for 1 hour per day for 5 consecutive days. The HAE groups were exposed to simulated HAE (9.7% O2 at 0.47 absolute atmospheres of 6,000 m) in a hypobaric chamber for 3 days. Polyclonal rabbit anti-mouse HSP-70-neutralizing Abs were intravenously injected 24 hours before the HAE experiments. Immediately after returning to normal atmosphere, the rats were given cognitive performance tests, overdosed with a general anesthetic, and then their brains were excised en bloc for water content measurements and biochemical evaluation and analysis. Non-HBO2P group rats displayed cognitive deficits, brain edema, and hippocampal oxidative stress (evidenced by increased toxic oxidizing radicals [e.g., nitric oxide metabolites and hydroxyl radicals], increased pro-oxidant enzymes [e.g., malondialdehyde and oxidized glutathione] but decreased antioxidant enzymes [e.g., reduced glutathione, glutathione peroxide, glutathione reductase, and superoxide dismutase]) in HAE. HBO2P induced HSP-70 overexpression in the hippocampus and significantly attenuated HAE-induced brain edema, cognitive deficits, and hippocampal oxidative stress. The beneficial effects of HBO2P were significantly reduced by HSP-70 Ab preconditioning. Our results suggest that high-altitude cerebral edema, cognitive deficit, and hippocampal oxidative stress can be prevented by HSP-70-mediated HBO2P in rats.

Improvement of Swirl Chamber Structure of Swirl-Chamber Diesel Engine Based on Flow Field Characteristics

Directory of Open Access Journals (Sweden)

Wenhua Yuan

2014-10-01

Full Text Available In order to improve combustion characteristic of swirl chamber diesel engine, a simulation model about a traditional cylindrical flat-bottom swirl chamber turbulent combustion diesel engine was established within the timeframe of the piston motion from the bottom dead centre (BDC to the top dead centre (TDC with the fluent dynamic mesh technique and flow field vector of gas in swirl chamber and cylinder; the pressure variation and temperature variation were obtained and a new type of swirl chamber structure was proposed. The results reveal that the piston will move from BDC; air in the cylinder is compressed into the swirl chamber by the piston to develop a swirl inside the chamber, with the ongoing of compression; the pressure and temperature are also rising gradually. Under this condition, the demand of diesel oil mixing and combusting will be better satisfied. Moreover, the new structure will no longer forma small fluid retention zone at the lower end outside the chamber and will be more beneficial to the mixing of fuel oil and air, which has presented a new idea and theoretical foundation for the design and optimization of swirl chamber structure and is thus of good significance of guiding in this regard.

Oxygen Equipment and Rapid Decompression Studies

Science.gov (United States)

1979-03-01

at 45,000 ft, Final Report, Contract FA-3082, May 1963. 8. Noble, L. E., J. C. Davis, 1. Margolis, and K. D. Kable: Hyperbaric Oxygen Therapy in a...drasticallymodify these results. 113 ’i 1 Reference 1. Stork, R. L., and T. R. Morgan: Oxygen Accumulation in Hypobaric Chambers, USAF School of Aerospace

Effects of hyperbaric oxygen therapy in enhancing expressions of e-NOS, TNF-α and VEGF in wound healing

Science.gov (United States)

Susilo, Imam; Devi, Anita; Purwandhono, Azham; Hadi Warsito, Sunaryo

2017-05-01

Wound healing is a physiological process that occurs progressively through overlapping phases. Tissue oxygenation is an important part of the complex regulation for wound healing. Hyperbaric Oxygen (HBO) therapy is a method of increasing oxygen delivery to tissues. The therapy improves tissue oxygenation and stimulates the formation of H2O2 as a secondary messenger for Tumour Necrosis Factor alpha (TNF α), e-NOS, VEGF and Nuclear Factor Kappa Beta phosphorylation (NF-Kb) which play an important role in the rapid transcription of a wide variety of genes in response to extracellular stimuli. This study aims to determine the effects of Hyperbaric Oxygen therapy in enhancing the expressions of e-NOS, TNF-α, VEGF and wound healing. This study is an animal study with a ‘randomized control group of pre-test and post test design’ on 28 Wistar rats. Randomly, the rats were divided into 4 groups with 7 rats in each group. The HBO treatment group 1 received 5 sessions of HBO 2.4 ATA in 3 × 30 minutes; the HBO treatment group 2 received 10 sessions of HBO 2.4 ATA in 3 × 30 minutes; and each of the control groups were without HBO. Each of the 28 male rats were given a full thickness excisional wound of 1 × 1cm. Examinations of e-NOS, TNF-α, VEGF expressions and wound healing were performed on day-0 (pre-HBO) and day-5 HBO or on day-0 (pre-HBO) and day-10 HBO. The resultsshowthat the Hyperbaric Oxygen therapy can improve e-NOS (p=0.02), TNF-α (p= 0.02), VEGF expression (p=0.02) and wound healing (p=0.002) significantly in the provision of HBO 2.4 ATA for 3 × 30 minutes in 5 sessions over 5 consecutive days. While the 10 sessions of HBO 2.4 ATA for 3 × 30 minutes over 10 consecutive days only increase e-NOS (p=0.02), TNF-α (p=0.04), VEGF expression significantly (p=0.03) but do not improve wound healing significantly (p=0.3) compared with no HBO. The study concludes that HBO can improve the expressions of e-NOS, TNF-α, VEGF and wound healing in the provision of HBO

Establishment of a radon test chamber

International Nuclear Information System (INIS)

Chen Chingjiang; Liu Chichang; Lin Yuming

1993-01-01

A walk-in type radon test chamber of 23 m 3 has been built for testing and calibration of radon measurement instruments. The environmental conditions of the test chamber can be varied within a wide range of values. The design objectives specification, monitoring instruments and testing results of this chamber are discussed. This test chamber is available for domestic radon researchers and its accuracy can be traced to the international standard. A routine intercomparison study will be held annually by using this chamber. Other tests like radon progeny and thoron standard may also be performed in this chamber. (1 fig.)

轻比重与重比重布比卡因腰麻在剖宫产术中的作用比较%Comparison between intrathecal hypobaric bupivacaine and hyperbaric bupivacaine for caesarean section

Institute of Scientific and Technical Information of China (English)

曲元; 徐成娣

2001-01-01

目的对0.125%轻比重布比卡因与0.5%重比重布比卡因腰麻在剖宫产术腰麻-硬膜外联合麻醉(CSEA)应用中的麻醉效果及并发症进行比较。方法随机选择60例拟行剖宫产手术的产妇，平均分为两组，均采用CSEA麻醉方法。分别向蛛网膜下腔注射0.5%重比重布比卡因1ml(重组)与0.125%轻比重布比卡因4ml(轻组)。结果重组起效时间明显比轻组短，腰麻后15分钟麻醉平面高于轻组(P均＜0.01)。轻组2%利多卡因用量显著多于重组(P＜0.05)。低血压发生率：重组43.3%，轻组16%；恶心呕吐发生率：重组26.7%，轻组6.7%，具有显著性差异。轻组的腰麻平面消退较重组快(33.4分钟对61.7分钟)。结论轻比重药液与重比重药液相比更具有对下肢运动神经阻滞轻、对循环影响小的特点。%Objective　Evaluating the effectiveness and complications by use of intrathecal injection of hypobaric and hyperbaric bupivacaine for caesarean section.Methods　Sixty term parturients were randomly divided into one of two groups and intrathecally recieved either:hypobaric group with 1ml of 0.125% bupivacaine and hyperbaric group with 4ml of 0.5% bupivacaine.Results　The onset time of hyperbaric group was shorter and level of spinal anesthesia was higher than hypobaric group (P＜0.05 or P＜0.01).The incidence of hypotension and nausea/vomitting was higher in hyperbaric groups (P＜0.05).Conclusions　The combined spinal-epidural technique,using hypobaric bupivacaine had advantages of less mobile nerves block and fewer complications than using hyperbaric bupivacaine.

National Ignition Facility Target Chamber

International Nuclear Information System (INIS)

Wavrik, R W; Cox, J R; Fleming, P J

2000-01-01

On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

Studies on hyperbaric WIG welding in the pressure range between 1 and 16 bar

International Nuclear Information System (INIS)

Huismann, G.

1985-01-01

Within the framework of this paper the following individual investigations were carried out for the application of the TIG process under hyperbar conditions (underwater welding): 1. Influence of the pressure on the formation and efficiency of the inert gas shield. 2. Influence of the materials and point geometry of the tungsten electrode on the erosion of those and the effect thereof on the welding process under increased pressure. 3. Influence of the pressure on the welding material geometry in blind-welding without welding material as well as built-in welding and root welding. 4. Influence of the pressure on the gas-metal reactions. The changes of the electric, mechanical and geometrical properties and characteristics of the electric arc by increased pressure are the fundamentals for understanding the resulting influences of the pressure on the properties of welded joints. (orig./MM) [de

Cloud Chamber

DEFF Research Database (Denmark)

Gfader, Verina

Cloud Chamber takes its roots in a performance project, titled The Guests 做东, devised by Verina Gfader for the 11th Shanghai Biennale, ‘Why Not Ask Again: Arguments, Counter-arguments, and Stories’. Departing from the inclusion of the biennale audience to write a future folk tale, Cloud Chamber......: fiction and translation and translation through time; post literacy; world picturing-world typing; and cartographic entanglements and expressions of subjectivity; through the lens a social imaginary of worlding or cosmological quest. Art at its core? Contributions by Nikos Papastergiadis, Rebecca Carson...

Hyperbaric oxygen therapy in experimental and clinical stroke

Directory of Open Access Journals (Sweden)

Wei-wei Zhai

2016-01-01

Full Text Available Stroke, which is defined as a neurologic deficit caused by sudden impaired blood supply, has been considered as a common cause of death and disability for decades. The World Health Organization has declared that almost every 5 seconds a new stroke occurs, placing immense socioeconomic burdens. However, the effective and available treatment strategies are still limited. Additionally, the most effective therapy, such as thrombolysis and stenting for ischemic stroke, generally requires a narrow therapeutic time window after the event. A large majority of patients cannot be admitted to hospital and receive these effective treatments for reperfusion timely. Hyperbaric oxygen therapy (HBOT has been frequently applied and investigated in stroke since 1960s. Numerous basic and clinical studies have shown the beneficial efficacy for neurological outcome after stroke, and meanwhile many underlying mechanisms associated with neuroprotection have been illustrated, such as cerebral oxygenation promotion and metabolic improvement, blood-brain barrier protection, anti-inflammation and cerebral edema, intracranial pressure modulation, decreased oxidative-stress and apoptosis, increased vascular and neural regeneration. However, HBOT in human stroke is still not sufficiently evidence-based, due to the insufficient randomized double-blind controlled clinical studies. To date, there are no uniform criteria for the dose and session duration of HBOT in different strokes. Furthermore, the additional effect of HBOT combined with drugs and other treatment strategies are being investigated recently. Therefore, more experimental and clinical research is imperative to identify the mechanisms more clearly and to explore the best protocol of HBOT in stroke treatment.

wire chamber

CERN Multimedia

1985-01-01

Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Wire chamber

CERN Multimedia

Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

wire chamber

CERN Multimedia

Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Criteria for controlled atmosphere chambers

International Nuclear Information System (INIS)

Robinson, J.N.

1980-03-01

The criteria for design, construction, and operation of controlled atmosphere chambers intended for service at ORNL are presented. Classification of chambers, materials for construction, design criteria, design, controlled atmosphere chamber systems, and operating procedures are presented. ORNL Safety Manual Procedure 2.1; ORNL Health Physics Procedure Manual Appendix A-7; and Design of Viewing Windows are included in 3 appendices

Proceedings of workshop on streamer chamber

International Nuclear Information System (INIS)

Itoh, Hidihiko; Takahashi, Kaoru; Hirose, Tachishige; Masaike, Akira

1978-08-01

For high accuracy observation of multiple-body reactions, a vertex detector of high efficiency is essential. A bubble chamber, though excellent for tracks detection, is problematic in statistics accuracy. The vertex detector with a wire chamber, while better in this respect, difficult in multiple-particle detection etc. The workshop has had several meetings on a streamer chamber as a detector combining features of both bubble chamber and counter, with emphasis on tracks observation in avalanche mode and recordings not using films. Contents are on streamer chamber gas, analytical photography, data processing, simulation program, etc. (Mori, K.)

Gridded Ionization Chamber

International Nuclear Information System (INIS)

Manero Amoros, F.

1962-01-01

In the present paper the working principles of a gridded ionization chamber are given, and all the different factors that determine its resolution power are analyzed in detail. One of these devices, built in the Physics Division of the JEN and designed specially for use in measurements of alpha spectroscopy, is described. finally the main applications, in which the chamber can be used, are shown. (Author) 17 refs

The CLEO III drift chamber

CERN Document Server

Peterson, D; Briere, R A; Chen, G; Cronin-Hennessy, D; Csorna, S; Dickson, M; Dombrowski, S V; Ecklund, K M; Lyon, A; Marka, S; Meyer, T O; Patterson, J R; Sadoff, A; Thies, P; Thorndike, E H; Urner, D

2002-01-01

The CLEO group at the Cornell Electron Storage Ring has constructed and commissioned a new central drift chamber. With 9796 cells arranged in 47 layers ranging in radius from 13.2 to 79 cm, the new drift chamber has a smaller outer radius and fewer wires than the drift chamber it replaces, but allows the CLEO tracking system to have improved momentum resolution. Reduced scattering material in the chamber gas and in the inner skin separating the drift chamber from the silicon vertex detector provides a reduction of the multiple scattering component of the momentum resolution and an extension of the usable measurement length into the silicon. Momentum resolution is further improved through quality control in wire positioning and symmetry of the electric fields in the drift cells which have provided a reduction in the spatial resolution to 88 mu m (averaged over the full drift range).

OPAL Jet Chamber Prototype

CERN Multimedia

OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

Absorbed dose measurement by using tissue equivalent ionization chamber (pair ionization chamber) in the Yayoi reactor

International Nuclear Information System (INIS)

Sasuga, N.; Okamura, K.; Terakado, T.; Mabuchi, Y.; Nakagawa, T.; Sukegawa, Toshio; Aizawa, C.; Saito, I.; Oka, Yoshiaki

1998-01-01

Each dose rate of neutron and gamma ray in the thermal column of the Yayoi reactor, in which an epithermal neutron field will be used for the boron neutron capture therapy, was measured by using a tissue equivalent ionization chamber and a graphite chamber. The tissue equivalent ionization chamber has some response to both neutron and gamma ray, but the graphite chamber has a few response to the neutron, so called pair ionization chamber method. The epithermal neutron fluxes of the thermal column were calculated by ANISN (one dimensional neutron-gamma transport code). A measured value for gamma dose rate by the pair ionization chamber agrees relevantly with a calculated result. For neutron dose rate, however, the measured value was too much small in comparison with the calculated result. The discrepancy between the measured value and the calculated result for neutron dose rate is discussed in detail in the report. (M. Suetake)

Development of secondary chamber for tar cracking-improvement of wood pyrolysis performance in pre-vacuum chamber

Science.gov (United States)

Siahaan, S.; Homma, H.; Homma, H.

2018-02-01

Energy crisis and global warming, in other words, climate change are critical topics discussed in various parts of the world. Global warming primarily result from too much emission of carbon dioxide (CO2) in the atmosphere. To mitigate global warming, or climate change and improve electrification in rural areas, wood pyrolysis technology is developed in a laboratory scale, of which gases are directly applicable to the gas engine generator. Our laboratory has developed a prototype of wood pyrolysis plant with a pre-vacuum chamber. However, tar yield was around 40 wt% of feedstock. This research aims to reduce tar yield by secondary tar cracking. For the secondary tar cracking, a secondary pre-vacuum chamber is installed after primary pre-vacuum chamber. Gases generated in the primary pre-vacuum chamber are lead into the secondary chamber that is heated up to 1000 K. This paper reports performance of the secondary chamber for secondary tar cracking in homogeneous mode and heterogeneous mode with char.

Hydrogen peroxide ingestion associated with portal venous gas and treatment with hyperbaric oxygen: a case series and review of the literature.

Science.gov (United States)

French, Loren Keith; Horowitz, B Zane; McKeown, Nathanael J

2010-07-01

Ingestion of concentrated hydrogen peroxide (H(2)O(2)) has been associated with venous and arterial gas embolic events, hemorrhagic gastritis, gastrointestinal bleeding, shock, and death. Although H(2)O(2) is generally considered a benign ingestion in low concentrations, case reports have described serious toxicity following high concentration exposures. Hyperbaric oxygen (HBO) has been used with success in managing patients suffering from gas embolism with and without manifestations of ischemia. Poison center records were searched from July 1999 to January 2010 for patients with H(2)O(2) exposure and HBO treatment. Cases were reviewed for the concentration of H(2)O(2), symptoms, CT scan findings of portal gas embolism, HBO treatment, and outcome. RESULTS; Eleven cases of portal gas embolism were found. Ages ranged from 4 to 89 years. All but one ingestion was accidental in nature. In 10 cases 35% H(2)O(2) was ingested and in 1 case 12% H(2)O(2) was ingested. All abdominal CT scans demonstrated portal venous gas embolism in all cases. Hyperbaric treatment was successful in completely resolving all portal venous gas bubbles in nine patients (80%) and nearly resolving them in two others. Ten patients were able to be discharged home within 1 day, and one patient had a 3.5-day length of stay. HBO was successful in resolving portal venous gas embolism from accidental concentrated H(2)O(2) ingestions.

Proportional chamber with data analog output

International Nuclear Information System (INIS)

Popov, V.E.; Prokof'ev, A.N.

1977-01-01

A proportional multiwier chamber is described. The chamber makes it possible to determine angles at wich a pion strikes a polarized target. A delay line, made of 60-core flat cable is used for removing signals from the chamber. From the delay line, signals are amplified and successively injected into shapers and a time-to-amplitude converter. An amplitude of the time-to amplitude converter output signal unambiguously determines the coordinate of a point at which a particle strikes the chamber plane. There are also given circuits of amplifiers, which consist of a preamplifier with gain 30 and a main amplifier with adjustable gain. Data on testing the chamber with the 450 MeV pion beam is demonstrated. The chamber features an efficiency of about 98 per cent under load of 2x10 5 s -1

wire chamber

CERN Multimedia

Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Proton beam monitor chamber calibration

International Nuclear Information System (INIS)

Gomà, C; Meer, D; Safai, S; Lorentini, S

2014-01-01

The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences—of the order of 3%—were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth—i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers—rather than cylindrical chambers—for the reference dosimetry of pseudo-monoenergetic proton beams. (paper)

Pressure vessel rupture within a chamber: the pressure history on the chamber wall

International Nuclear Information System (INIS)

Baum, M.R.

1989-04-01

Generally there is a large number of pressure vessels containing high pressure gas on power stations and chemical plant. In many instances, particularly on power plant, these vessels are within the main building. If a pressure vessel were to fail, the surrounding structures would be exposed to blast loads and the forces resulting from jets of fluid issuing from the breached vessel. In the case where the vessel is in a relatively closed chamber there would also be a general overpressurisation of the chamber. At the design stage it is therefore essential to demonstrate that the plant could be safely shut down in the event of a pressure vessel failure, that is, it must be shown that the chamber will not collapse thus putting the building at risk or hazarding equipment essential for a safe shut down. Such an assessment requires the loads applied to the chamber walls, roof, etc. to be known. (author)

Wet drift chambers for precise luminosity

International Nuclear Information System (INIS)

Anderson, B.E.; Kennedy, B.W.; Ahmet, K.; Attree, D.J.; Barraclough, G.A.; Cresswell, M.J.; Hayes, D.A.; Miller, D.J.; Selby, C.; Sherwood, P.

1994-01-01

A set of high-precision compact drift chambers has been a vital component of the OPAL luminosity monitor since the start of data-taking at LEP. They were augmented in 1992 by the addition of Small Angle Reference Chambers with a very similar design to the original chamber. The performance of the chambers is reviewed, highlighting both the importance of using polyalkylene glycol (Breox) to maintain a uniform and parallel electric field and the construction techniques used to sustain the required field strength. We describe some of the operating problems, with their solutions, and show how the chambers have been used in achieving a systematic error of 0.41% on the luminosity measurement. ((orig.))

The Boycott effect in magma chambers

Science.gov (United States)

Blanchette, F.; Peacock, T.; Bush, J. W. M.

2004-03-01

We investigate the plausibility of the stratified Boycott effect as a source of layering in magma chambers. Crystal settling within the magma chamber will generate buoyant fluid near the sloping sidewalls whose vertical ascent may be limited by the ambient stratification associated with vertical gradients in SiO2. The resulting flow may be marked by a layered structure, each layer taking the form of a convection cell spanning the lateral extent of the magma chamber. Using parameters relevant to magma chambers, we estimate that such convection cells would be established over a timescale of a month and have a depth on the order of 4m, which is roughly consistent with field observations of strata within solidified chambers.

The KEK 1 m hydrogen bubble chamber

International Nuclear Information System (INIS)

Doi, Yoshikuni; Araoka, Osamu; Hayashi, Kohei; Hayashi, Yoshio; Hirabayashi, Hiromi.

1978-03-01

A medium size hydrogen bubble chamber has been constructed at the National Laboratory for High Energy Physics, KEK. The bubble chamber has been designed to be operated with a maximum rate of three times per half a second in every two second repetition time of the accelerator, by utilizing a hydraulic expansion system. The bubble chamber has a one meter diameter and a visible volume of about 280 l. A three-view stereo camera system is used for taking photographic pictures of the chamber. A 2 MW bubble chamber magnet is constructed. The main part of the bubble chamber vessel is supported by the magnet yoke. The magnet gives a maximum field of 18.4 kG at the centre of the fiducial volume of the chamber. The overall system of the KEK 1 m hydrogen bubble chamber facility is described in some detail. Some operational characteristics of the facility are also reported. (auth.)

Loss of ions in cavity ionization chambers

International Nuclear Information System (INIS)

Takata, N.; Tran, N.T.; Kim, E.; Marsoem, P.; Kurosawa, T.; Koyama, Y.

2005-01-01

Ion losses due to initial recombination, volume recombination, and back diffusion were each determined by measurements and calculations for different size cylindrical ionization chambers and spherical ionization chambers. By measuring signal currents from these ionization chambers irradiated with 60 Co gamma rays, two groups of ion losses were obtained. (Group 1) Ion loss due to initial recombination and diffusion, which changes proportionally to the inverse of the voltage applied to the ionization chambers; (and group 2) ion loss due to volume recombination, which changes proportionally to the inverse of the square of the applied voltage. The diffusion loss was obtained separately by computing electric field distributions in the ionization chambers. It was found that diffusion loss is larger than initial recombination loss for the cylindrical ionization chambers and vise versa for the spherical ionization chambers

Investigation of very long jet chambers

Energy Technology Data Exchange (ETDEWEB)

Burckhart, H J; Va' vra, J; Zankel, K; Dudziak, U; Schaile, D; Schaile, O; Igo-Kemenes, P; Lennert, P

1986-04-01

The electrostatic properties and the performances of very long jet chambers have been investigated. Using 100 MHz FADC wave form digitisers, the tracking accuracy, the charge division and the dE/dx performance of two chambers, one with 4.5 m long tungsten wires and one with 4 m long highly resistive ''NiCoTi'' wires have been studied. The geometry of the chambers was chosen to define some of the design parameters of the jet chamber for the OPAL detector for LEP.

IFE chamber technology testing program in NIF and chamber development test plan

International Nuclear Information System (INIS)

Abdou, M.A.

1995-01-01

Issues concerning chamber technology testing program in NIF involving: criteria for evaluation/prioritization of experiments, engineering scaling requirements for test article design and material selection and R and D plan prior to NIF testing were addressed in this paper. In order to maximize the benefits of testing program in NIF, the testing in NIF should provide the experimental data relevant to DEMO design choice or to DEMO design predictive capability by utilizing engineering scaling test article designs. Test plans were developed for 2 promising chamber design concepts. Early testing in non-fusion/non-ignition prior to testing in ignition facility serves a critical role in chamber R and D test plans in order to reduce the risks and costs of the more complex experiments in NIF

Impedances in lossy elliptical vacuum chambers

International Nuclear Information System (INIS)

Piwinski, A.

1994-04-01

The wake fields of a bunched beam caused by the resistivity of the chamber walls are investigated for a vacuum chamber with elliptical cross section. The longitudinal and transverse impedances are calculated for arbitrary energies and for an arbitrary position of the beam in the chamber. (orig.)

Investigation of very long jet chambers

Energy Technology Data Exchange (ETDEWEB)

Burckhart, H J; Va' vra, J; Zankel, K; Dudziak, U; Schaile, D; Schaile, O; Igo-Kemenes, P; Lennert, P

1986-04-01

The electrostatic properties and the performances of very long jet chambers have been investigated. Using 100 MHz FADC wave form digitisers, the tracking accuracy, the charge division and the dE/dx performance of two chambers, one with 4.5 m long tungsten wires and one with 4 m long highly resistive ''NiCoTi'' wires have been studied. The geometry of the chambers was chosen to define some of the design parameters of the jet chamber for the OPAL detector for LEP. (orig.).

Chamber propagation physics for heavy ion fusion

International Nuclear Information System (INIS)

Callahan, D.A.

1995-01-01

Chamber transport is an important area of study for heavy ion fusion. Final focus and chamber-transport are high leverage areas providing opportunities to significantly decrease the cost of electricity from a heavy ion fusion power plant. Chamber transport in two basic regimes is under consideration. In the low chamber density regime (approx-lt 0.003 torr), ballistic or nearly-ballistic transport is used. Partial beam neutralization has been studied to offset the effects of beam stripping. In the high chamber density regime (approx-gt.1 torr), two transport modes (pinched transport and channel transport) are under investigation. Both involve focusing the beam outside the chamber then transporting it at small radius (∼ 2 mm). Both high chamber density modes relax the constraints on the beam quality needed from the accelerator which will reduce the driver cost and the cost of electricity

Extension of raw watermelon juice shelf-life up to 58days by hyperbaric storage.

Science.gov (United States)

Lemos, Álvaro T; Ribeiro, Ana C; Fidalgo, Liliana G; Delgadillo, Ivonne; Saraiva, Jorge A

2017-09-15

Hyperbaric storage (HS) of raw watermelon juice, at 50, 62.5 and 75MPa, at temperatures of 10, 15 and ≈25°C (room temperature, RT), was studied to evaluate shelf-life comparatively to refrigeration (RF, 4°C). Generally, RF caused an increase of microbial loads to values ≥6.0logCFU/mL after 7days of storage. Contrarily, HS at 62.5/75MPa (15°C) showed a reduction of initial loads, by at least 2.5logCFU/mL, up to 58days, while pH and colour values did not changed under these HS conditions. Additionally, the combination of a lower temperature with HS has beneficial effects to control microbial development, particularly for the lower pressure studied (50MPa/10°C). In conclusion, HS increased watermelon juice shelf-life for at least 58days, indicating a great potential for future RF replacement. Copyright © 2017 Elsevier Ltd. All rights reserved.

Parameter study of temperature distribution in a work-piece during dry hyperbaric GTA-welding

International Nuclear Information System (INIS)

Fulfs, H.

1989-01-01

In a sensitivity study the influence of initial and boundary welding parameters upon the spatial and temporal temperature distribution in a work-piece during dry hyperbaric GTA-welding is investigated. It will be shown that at constant arc current a variation of pressure (1-60 bar), arc length (3-10 mm), welding speed (1-2.5 mm/s) or the initial temperature (20-200deg C) of the work-piece to some extend significantly influences the size of melt and heat affected zone as well as the maximum temperature and cooling behaviour of the work-piece; compared to this no mentionable effects of shielding gas temperature (20-300deg C) or flow rate (10-500 dm N 3 /min) on the thermal condition of the work-piece can be recognized. The discovered relationships have been approximated by simple correlations, which can be used for parameter optimization and process control. (orig.) With 33 figs., 4 tabs [de

Intrathecal hypobaric versus hyperbaric bupivacaine with morphine for cesarean section.

Science.gov (United States)

Richardson, M G; Collins, H V; Wissler, R N

1998-08-01

Both hyper- and hypobaric solutions of bupivacaine are often combined with morphine to provide subarachnoid anesthesia for cesarean section. Differences in the baricity of subarachnoid solutions influence the intrathecal distribution of anesthetic drugs and would be expected to influence measurable clinical variables. We compared the effects of hyper- and hypobaric subarachnoid bupivacaine with morphine to determine whether one has significant advantages with regard to intraoperative anesthesia and postoperative analgesia in term parturients undergoing elective cesarean section. Thirty parturients were randomized to receive either hyper- or hypobaric bupivacaine (15 mg) with morphine sulfate (0.2 mg). Intraoperative outcomes compared included extent of sensory block, quality of anesthesia, and side effects. Postoperative outcomes, including pain visual analog scale scores, systemic analgesic requirements, and side effects, were monitored for 48 h. Sedation effects were quantified and compared using Trieger and digit-symbol substitution tests. We detected no differences in sensory or motor block, quality of anesthesia, quality of postoperative analgesia, incidence of side effects, or psychometric scores. Both preparations provide highly satisfactory anesthesia for cesarean section and effective postoperative analgesia. Dextrose alters the density of intrathecal bupivacaine solutions and is thought to influence subarachnoid distribution of the drug. We randomized parturients undergoing cesarean section to one of two often used spinal bupivacaine preparations, hypobaric and hyperbaric. We detected no differences in clinical outcomes between groups.

Operational Medical Issues in Hypo-and Hyperbaric Conditions (les Questions medicales a caractere oprationel liees aux conditions hypobares ou hyperbares)

Science.gov (United States)

2001-06-01

Research Centre; 1994:54-59. 15. Rudge FW. Relationship of menstrual history to altitude chamber decompression sickness. Aviation, Space, and...This is due to the pattern of the O2 dissociation curve. At low O2 saturation the same shunt gives a smaller effect on Pa,O2 versus PA,O2. 41-4 COPA

Multiwire proportional chamber and multistage avalanche chamber with low concentration photoionization gas

International Nuclear Information System (INIS)

Zhao Pingde; Xu Zhiqing; Tang Xiaowei

1986-01-01

The characteristics of multiwire proportional chamber and multistage avalanche chamber filled with argon and photoionization gas (C 2 H 5 ) 3 N were measured. The spatial resolution curves and output pulse height spectra were measured as well. Low concentration (C 2 H 5 ) 3 N can play an effective part in quenching. At very low concentration, the phenomena of avalanche transverse expansion was observed obviously

PEP quark search proportional chambers

Energy Technology Data Exchange (ETDEWEB)

Parker, S I; Harris, F; Karliner, I; Yount, D [Hawaii Univ., Honolulu (USA); Ely, R; Hamilton, R; Pun, T [California Univ., Berkeley (USA). Lawrence Berkeley Lab.; Guryn, W; Miller, D; Fries, R [Northwestern Univ., Evanston, IL (USA)

1981-04-01

Proportional chambers are used in the PEP Free Quark Search to identify and remove possible background sources such as particles traversing the edges of counters, to permit geometric corrections to the dE/dx and TOF information from the scintillator and Cerenkov counters, and to look for possible high cross section quarks. The present beam pipe has a thickness of 0.007 interaction lengths (lambdasub(i)) and is followed in both arms each with 45/sup 0/ <= theta <= 135/sup 0/, ..delta..phi=90/sup 0/ by 5 proportional chambers, each 0.0008 lambdasub(i) thick with 32 channels of pulse height readout, and by 3 thin scintillator planes, each 0.003 lambdasub(i) thick. Following this thin front end, each arm of the detector has 8 layers of scintillator (one with scintillating light pipes) interspersed with 4 proportional chambers and a layer of lucite Cerenkov counters. Both the calculated ion statistics and measurements using He-CH/sub 4/ gas in a test chamber indicate that the chamber efficiencies should be >98% for q=1/3. The Landau spread measured in the test was equal to that observed for normal q=1 traversals. One scintillator plane and thin chamber in each arm will have an extra set of ADC's with a wide gate bracketing the normal one so timing errors and tails of earlier pulses should not produce fake quarks.

Argus target chamber

International Nuclear Information System (INIS)

Rienecker, F. Jr.; Glaros, S.S.; Kobierecki, M.

1975-01-01

A target chamber for application in the laser fusion program must satisfy some very basic requirements. (1) Provide a vacuum on the order of 10 -6 torr. (2) Support a microscopically small target in a fixed point in space and verify its location within 5 micrometers. (3) Contain an adjustable beam focusing system capable of delivering a number of laser beams onto the target simultaneously, both in time and space. (4) Provide access for diagnostics to evaluate the results of target irradiation. (5) Have flexibility to allow changes in targets, focusing optics and number of beams. The ARGUS laser which is now under construction at LLL will have a target chamber which meets these requirements in a simple economic manner. The chamber and auxiliary equipment are described, with reference to two double beam focusing systems; namely, lenses and ellipsoidal mirrors. Provision is made for future operation with four beams, using ellipsoidal mirrors for two-sided illumination and lens systems for tetragonal and tetrahedral irradiation

Cylindrical ionization chamber with compressed krypton

International Nuclear Information System (INIS)

Kuz'minov, V.V.; Novikov, V.M.; Pomanskii, A.A.; Pritychenko, B.V.; Viyar, J.; Garcia, E.; Morales, A.; Morales, J.; Nunes-Lagos, R.; Puimedon, J.; Saens, K.; Salinas, A.; Sarsa, M.

1993-01-01

A cylindrical ionization chamber with a grid is used to search for double positron decay and atomic electron conversion to a positron in 78 Kr. Krypton is the working gas material of the chamber. The spectrometric characteristics of the chamber filled with krypton and xenon are presented. The energy resolution is 2.1% for an energy of 1.84 MeV (the source of γ-quanta is 88 Y) when the chamber is filled with a mixture of Kr+0.2% H 2 under a pressure of 25 atm

Advances on fission chamber modelling

International Nuclear Information System (INIS)

Filliatre, Philippe; Jammes, Christian; Geslot, Benoit; Veenhof, Rob

2013-06-01

In-vessel, online neutron flux measurements are routinely performed in mock-up and material testing reactors by fission chambers. Those measurements have a wide range of applications, including characterization of experimental conditions, reactor monitoring and safety. Depending on the application, detectors may experience a wide range of constraints, of several magnitudes, in term of neutron flux, gamma-ray flux, temperature. Hence, designing a specific fission chamber and measuring chain for a given application is a demanding task. It can be achieved by a combination of experimental feedback and simulating tools, the latter being based on a comprehensive understanding of the underlying physics. A computation route that simulates fission chambers, named CHESTER, is presented. The retrieved quantities of interest are the neutron-induced charge spectrum, the electronic and ionic pulses, the mean current and variance, the power spectrum. It relies on the GARFIELD suite, originally developed for drift chambers, and makes use of the MAGBOLTZ code to assess the drift parameters of electrons within the filling gas, and the SRIM code to evaluate the stopping range of fission products. The effect of the gamma flux is also estimated. Computations made with several fission chambers exemplify the possibilities of the route. A good qualitative agreement is obtained when comparing the results with the experimental data available to date. In a near future, a comprehensive experimental programme will be undertaken to qualify the route using the known neutron sources, mock-up reactors and wide choice of fission chambers, with a stress on the predictiveness of the Campbelling mode. Depending on the results, a refinement of the modelling and an effort on the accuracy of input data are also to be considered. CHESTER will then make it possible to predict the overall sensitivity of a chamber, and to optimize the design for a given application. Another benefit will be to increase the

An electrodeless drift chamber

International Nuclear Information System (INIS)

Allison, J.; Barlow, R.J.; Bowdery, C.K.; Duerdoth, I.; Rowe, P.G.

1982-01-01

We describe a chamber in which the drift field is controlled by the deposition of electrostatic charge on an insulating surface. The chamber operates with good efficiency and precision for observed drift distances of up to 45 cm, promises to be extremely robust and adaptable and offers a very cheap way of making particle detectors. (orig.)

DELPHI time projection chamber

CERN Multimedia

1989-01-01

The time projection chamber is inserted inside the central detector of the DELPHI experiment. Gas is ionised in the chamber as a charged particle passes through, producing an electric signal from which the path of the particle can be found. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

Chamber propagation physics for heavy ion fusion

International Nuclear Information System (INIS)

Callahan, D.A.

1996-01-01

Chamber transport is a key area of study for heavy ion fusion. Final focus and chamber transport are high leverage areas providing opportunities to decrease significantly the cost of electricity from a heavy ion fusion power plant. Chamber transport in two basic regimes is under consideration. In the low chamber density regime (below about 0.003 Torr), ballistic or nearly ballistic transport is used. Partial beam neutralization has been studied to offset the effects of beam stripping. In the high chamber density regime (above about 0.1 Torr), two transport modes (pinched transport and channel transport) are under investigation. Both involve focusing the beam outside the chamber and then transporting it at small radius (about 2 mm). Both high chamber density modes relax the constraints on the beam quality needed from the accelerator which will reduce the driver cost and the cost of electricity. (orig.)

How to build a cloud chamber?

International Nuclear Information System (INIS)

Mariaud, C.

2012-01-01

The cloud chamber had its heyday in the first half of last century and allowed the discovery of new particles such as the anti-electron, the muon and the neutral and the charged kaon. The bubble chamber replaced it in the mid fifties. This article recalls the principle of the cloud chamber and shows, in a detailed way, how to proceed to build one with on-the-shelf materials. This design is based on the use of isopropanol whose liquefaction through the form of droplets materializes the track of the particle and on the use of combined Peltier cells (instead of CO 2 snow) to cool the chamber. This cloud chamber has been successfully used in schools to observe particles mainly electrons, alphas and muons generated by cosmic rays. (A.C.)

A mathematical model of aerosol holding chambers

DEFF Research Database (Denmark)

Zak, M; Madsen, J; Berg, E

1999-01-01

A mathematical model of aerosol delivery from holding chambers (spacers) was developed incorporating tidal volume (VT), chamber volume (Vch), apparatus dead space (VD), effect of valve insufficiency and other leaks, loss of aerosol by immediate impact on the chamber wall, and fallout of aerosol...... in the chamber with time. Four different spacers were connected via filters to a mechanical lung model, and aerosol delivery during "breathing" was determined from drug recovery from the filters. The formula correctly predicted the delivery of budesonide aerosol from the AeroChamber (Trudell Medical, London...

Hyperbaric oxygen therapy for cognitive disorders after irradiation of the brain

Energy Technology Data Exchange (ETDEWEB)

Hulshof, M C.C.M.; Sminia, P; Gonzalez, D G [Amsterdam Univ. (Netherlands). Dept. of Radiation Oncology; Stark, N M; Smeding, H M.M. [Amsterdam Univ. (Netherlands). Dept. of Neurology; Kleij, A van der [Amsterdam Univ. (Netherlands). Dept. of Surgery/Hyperbaric Oxygen

2002-04-01

Purpose: Analysis of the feasibility and effect of hyperbaric oxygen treatment (HBO) on cognitive functioning in patients with cognitive disorders after irradiation of the brain. Patients and Method: Seven patients with cognitive impairment after brain irradiation, with an interval of at least 1.5 years after treatment, were treated with 30 sessions of HBO in a phase I-II study. A comprehensive neuropsychological test battery was performed before treatment, at 3 and 6 months thereafter. Patients were randomized into an immediate treatment group and a delayed treatment group. The delayed group had a second neurospychological test at 3 months without treatment in that period and started HBO thereafter. Results: All eligible patients completed the HBO treatment and the extensive neuropsychological testing. One out of seven patients had a meaningful improvement in neuropsychological functioning. At 3 months there was a small, but not significant benefit in neuropsychological performance for the group with HBO compared to the group without HBO treatment. Six out of seven patients eventually showed improvement after HBO in one to nine (median 2.5) of the 31 tests, although without statistical significance. Conclusion: HBO treatment was feasible and resulted in a meaningful improvement of cognitive functioning in one out of seven patients. Overall there was a small but not significant improvement. (orig.)

Hyperbaric oxygen therapy for cognitive disorders after irradiation of the brain

International Nuclear Information System (INIS)

Hulshof, M.C.C.M.; Sminia, P.; Gonzalez, D.G.; Stark, N.M.; Smeding, H.M.M.; Kleij, A. van der

2002-01-01

Purpose: Analysis of the feasibility and effect of hyperbaric oxygen treatment (HBO) on cognitive functioning in patients with cognitive disorders after irradiation of the brain. Patients and Method: Seven patients with cognitive impairment after brain irradiation, with an interval of at least 1.5 years after treatment, were treated with 30 sessions of HBO in a phase I-II study. A comprehensive neuropsychological test battery was performed before treatment, at 3 and 6 months thereafter. Patients were randomized into an immediate treatment group and a delayed treatment group. The delayed group had a second neurospychological test at 3 months without treatment in that period and started HBO thereafter. Results: All eligible patients completed the HBO treatment and the extensive neuropsychological testing. One out of seven patients had a meaningful improvement in neuropsychological functioning. At 3 months there was a small, but not significant benefit in neuropsychological performance for the group with HBO compared to the group without HBO treatment. Six out of seven patients eventually showed improvement after HBO in one to nine (median 2.5) of the 31 tests, although without statistical significance. Conclusion: HBO treatment was feasible and resulted in a meaningful improvement of cognitive functioning in one out of seven patients. Overall there was a small but not significant improvement. (orig.)

Treatment of laryngeal radionecrosis with hyperbaric oxygen therapy. A case report

International Nuclear Information System (INIS)

Nishida, Akiko T.; Honda, Nobumitsu; Tsujimura, Mika; Adachi, Tsunemichi; Fujiki, Nobuya; Miyata, Kouji; Fukushima, Hideyuki; Kitani, Yoshiharu

2007-01-01

Laryngeal necrosis is a rare complication of radiotherapy for early-staged laryngeal or hypopharyngeal cancer. However, when it occurs, there is no definitive treatment and laryngectomy is frequently required. Here we present a case of advanced laryngeal necrosis (grade 4, Chandler classification) treated with hyperbaric oxygen (HBO) therapy. A 60-year-old woman received radiotherapy with 64.8 Gy for early-staged hypopharyngeal cancer in combination with three courses of cisplatin (40 mg/body/week). She developed pharyngeal pain and progressive dyspnea because of laryngeal edema 3 months after the completion of radiotherapy, and received an emergent tracheostomy. In order to differentiate radiation injury from cancer recurrence, biopsies were obtained under direct laryngoscopy and showed intense necrosis without malignancy. Since laryngeal radionecrosis was presumed, the patient received HBO therapy at 2 atmospheres absolute (ATA) with 100% O 2 for 2 hours per session. After 20 HBO treatments, laryngeal edema improved and her clinical symptoms including pharyngeal pain, swallowing pain and dysphagia, were ameliorated significantly. However, decannulation has not been achieved because of bilateral vocal cord fixation. We considered that HBO therapy was effective in the present case and that HBO therapy should be recommended as a therapeutic option whenever laryngeal necrosis occurs and there is a chance to save the larynx. (author)

Quality control of ATLAS muon chambers

CERN Document Server

Fabich, Adrian

ATLAS is a general-purpose experiment for the future Large Hadron Collider (LHC) at CERN. Its Muon Spectrometer will require ∼ 5500m2 of precision tracking chambers to measure the muon tracks along a spectrometer arm of 5m to 15m length, embedded in a magnetic field of ∼ 0.5T. The precision tracking devices in the Muon System will be high pressure drift tubes (MDTs). Approximately 370,000 MDTs will be assembled into ∼ 1200 drift chambers. The performance of the MDT chambers is very much dependent on the mechanical quality of the chambers. The uniformity and stability of the performance can only be assured providing very high quality control during production. Gas tightness, high-voltage behaviour and dark currents are global parameters which are common to gas detectors. For all chambers, they will be tested immediately after the chamber assembly at every production site. Functional tests, for example radioactive source scans and cosmic-ray runs, will be performed in order to establish detailed performan...

HVAC&R Equipment Environmental Chambers

Data.gov (United States)

Federal Laboratory Consortium — Description:Large "Truck" ChamberThe large "truck" chamber provides controlled air conditions from -7 °C (20 °F) to 65 °C (150 °F).Air-Conditioner and Heat Pump Test...

Micro plate fission chamber development

International Nuclear Information System (INIS)

Wang Mei; Wen Zhongwei; Lin Jufang; Jiang Li; Liu Rong; Wang Dalun

2014-01-01

To conduct the measurement of neutron flux and the fission rate distribution at several position in assemblies, the micro plate fission chamber was designed and fabricated. Since the requirement of smaller volume and less structure material was taken into consideration, it is convinient, commercial and practical to use fission chamber to measure neutron flux in specific condition. In this paper, the structure of fission chamber and process of fabrication were introduced and performance test result was presented. The detection efficiency is 91.7%. (authors)

Ionization chamber for smoke detector and the like

International Nuclear Information System (INIS)

Rork, G.D.; Thorp, E.J.; Zegarski, R.J.

1985-01-01

This invention relates to detectors of the ionization type for detecting airborne particulate matter and, in particular, to the construction of an ionization chamber for such a detector. This invention may be used for detecting a variety of materials, such as dust, fog and the like, but is particularly useful for detecting combustion products such as smoke. The smoke detector ionization chamber has two electrodes connected to a source of electric power; means defining access openings for enabling air flow into and out of the chamber; and means for causing ionization within the chamber. It has control structure means within the chamber in the path of the airflow cooperating with the electrodes to establish within the chamber an electric field having a higher intensity close to the access openings and a lower intensity in the remainder of the chamber without significantly impairing the flow of neutral particles into the chamber. The control structure reduces airflow velocity within the chamber without adversely affecting the access of airborne particles to the chamber

Liquid Wall Chambers

Energy Technology Data Exchange (ETDEWEB)

Meier, W R

2011-02-24

The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

High resolution drift chambers

International Nuclear Information System (INIS)

Va'vra, J.

1985-07-01

High precision drift chambers capable of achieving less than or equal to 50 μm resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs

The Mark II Vertex Drift Chamber

International Nuclear Information System (INIS)

Alexander, J.P.; Baggs, R.; Fujino, D.

1989-03-01

We have completed constructing and begun operating the Mark II Drift Chamber Vertex Detector. The chamber, based on a modified jet cell design, achieves 30 μm spatial resolution and 2 gas mixtures. Special emphasis has been placed on controlling systematic errors including the use of novel construction techniques which permit accurate wire placement. Chamber performance has been studied with cosmic ray tracks collected with the chamber located both inside and outside the Mark II. Results on spatial resolution, average pulse shape, and some properties of CO 2 mixtures are presented. 10 refs., 12 figs., 1 tab

Bicone vacuum chamber for ISR intersection

CERN Multimedia

1975-01-01

This is one of the bicone chambers made of titanium for experiment R 702. The central corrugated part had a very thin titanium wall (0.28 mm). The first of these chambers collapsed in its central part when baked at 300 C (August 1975). After an intensive effort to develop better quality and reproducible welds for this special material, the ISR workshop was able to build two new chambers of this type. One of them was installed at I 7 for R 702 in 1976 and worked perfectly. It was at that time the most "transparent" intersection vacuum chamber. See also 7609219, 7609221.

Growing and analyzing biofilms in flow chambers

DEFF Research Database (Denmark)

Tolker-Nielsen, Tim; Sternberg, Claus

2011-01-01

This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber-grown biofilms are addressed....

Microstrip gas chamber on thin-film Pestov glass and micro gap chamber

International Nuclear Information System (INIS)

Gong, W.G.; Harris, J.W.; Wieman, H.

1994-07-01

The authors report developments of the Microstrip Gas Chamber on thin-film Pestov glass and the Micro Gap Chamber. By coating a thin-layer of low-resistive, electronically-conductive glass on various substrates (including quartz and ceramics), they built MSGCs of high gain stability and low leakage current. They were tested in Ar-CH 4 (10%) and He-C 2 H 6 (50%) gas mixtures. Energy resolutions of 17-20% were measured for 6keV x-rays. This design can make the choice of substrate less important, save the cost of ion-implantation, and use less glass material. Micro Gap Chamber was successfully tested in He-C 2 H 6 (50%) and Ar-C 2 H 6 (50%) gas mixtures. Energy resolutions of about 20% were obtained. Both detectors are expected to have high rate capability

Comparison among different CT ionization chambers

International Nuclear Information System (INIS)

Castro, Maysa C. de; Xavier, Marcos; Caldas, Linda V.E.

2015-01-01

The dosimetry in computed tomography (CT) is carried out by the use of a pencil type ionization-chamber, because it has a uniform response at all angles relative to the incident beam of radiation, which is essential for CT equipment since the X-ray tube executes a circular movement around the table during irradiation. The commercial ionization chamber used to perform quality control procedures of this kind of equipment has a length of the sensitive volume of 10 cm. In the Calibration Laboratory of Instruments (LCI) of the IPEN there were already developed some prototypes with small differences in construction, when compared to commercially available ionization chambers. They have been used in previous studies and showed results within internationally acceptable limits. The ionization chambers tested in this study present the sensitive volume lengths of 1 cm, 3 cm and 10 cm. The objective of this study was to present results on the stability test of the three homemade ionization chambers and a commercial chamber, as well to obtain the calibration coefficients for each of them in CT standard X radiation beams. The obtained results for both characterization tests are within the recommended limits, except for the homemade ionization chambers with sensitive volume lengths of 3 cm and 1 cm in the case of the stability test. (author)

An Annotated Bibliography of Hypobaric Decompression Sickness Research Conducted at the Crew Technology Division, USAF School of Aerospace Medicine, Brooks AFB, Texas from 1983 to 1988

Science.gov (United States)

1990-06-01

AN ANNOTATED BIBLIOGRAPHY OF HYPOBARIC DECOMPRESSION SICKNESS RESEARCH CONDUCTED AT THE CREW TECHNOLOGY DIVISION, USAF SCHOOL OF AEROSPACE MEDICINE...190 man-flights to four selected altitudes (30000, 27500, 25000, and 22500 ft pressure equivalent) in a hypobaric chamber. The subjects’ ages ranged...conditions and two of these developed delayed sy~rtcms. Three of these five subjects underwent hyperbaric oxygen treatment. Conclusion. Female subjects

IN VITRO STUDIES ON HEME OXYGENASE-1 AND P24 ANTIGEN HIV-1 LEVEL AFTERHYPERBARIC OXYGEN TREATMENTOFHIV-1 INFECTED ON PERIPHERAL BLOOD MONONUCLEAR CELLS (PBMCS).

Science.gov (United States)

Budiarti, Retno; Kuntaman; Nasronudin; Suryokusumo; Khairunisa, Siti Qamariyah

2018-01-01

Heme oxygenase-1 (HO-1) is a protein secreted by immune cells as a part of immune response mechanism.HO-1 can be induced by variety agents that causingoxidative stress, such as exposure to 100% oxygenat2,4 ATA pressure.It plays a vital role in maintaining cellular homeostasis.This study was conducted to identify the effect of hyperbaric oxygen exposure in cultured ofPBMCthat infected by HIV-1. Primary culture of PBMCs were isolated from 16 healthy volunteers and HIV-1 infected MT4 cell line by co-culture. The PBMCs were aliquoted into two wells as control group and treatment group. The 16 samples of HIV-1 infected PBMCwere exposed to oxygen at 2,4 ATA in animal hyperbaric chamber forthree times in 30 minutes periods with 5 minutes spacing period, that called 1 session.The Treatment done on 5 sessions within 5 days. 16 samples of HIV-1 infected PMBCs that have no hyperbaric treatment became control group.The supernatant were measured the HO-1 production by ELISA andmRNA expression of HO-1 by real time PCR and the number ofantigen p24 HIV-1by ELISA. The result showed that there was no increasing of HO-1 at both mRNA level and protein level, there was a decreasing number of antigen p24 HIV-1 at the treatment group. In addition, hyperbaric exposure could not increase the expression of HO-1, more over the viral replication might be reduced by other mechanism. Hyperbaric oxygen could increases cellular adaptive response of PBMCs infected HIV-1 through increased expression of proteins that can inhibit HIV viralreplication.

The effect of hyperbaric oxygen treatment on aspiration pneumonia.

Science.gov (United States)

Sahin, Sevtap Hekimoglu; Kanter, Mehmet; Ayvaz, Suleyman; Colak, Alkin; Aksu, Burhan; Guzel, Ahmet; Basaran, Umit Nusret; Erboga, Mustafa; Ozcan, Ali

2011-08-01

We have studied whether hyperbaric oxygen (HBO) prevents different pulmonary aspiration materials-induced lung injury in rats. The experiments were designed in 60 Sprague-Dawley rats, ranging in weight from 250 to 300 g, randomly allotted into one of six groups (n = 10): saline control, Biosorb Energy Plus (BIO), hydrochloric acid (HCl), saline + HBO treated, BIO + HBO treated, and HCl + HBO treated. Saline, BIO, HCl were injected into the lungs in a volume of 2 ml/kg. A total of seven HBO sessions were performed at 2,4 atm 100% oxygen for 90 min at 6-h intervals. Seven days later, rats were sacrificed, and both lungs in all groups were examined biochemically and histopathologically. Our findings show that HBO inhibits the inflammatory response reducing significantly (P fibrosis, granuloma, and necrosis formation in different pulmonary aspiration models. Pulmonar aspiration significantly increased the tissue HP content, malondialdehyde (MDA) levels and decreased (P < 0.05) the antioxidant enzyme (SOD, GSH-Px) activities. HBO treatment significantly (P < 0.05) decreased the elevated tissue HP content, and MDA levels and prevented inhibition of SOD, and GSH-Px (P < 0.05) enzymes in the tissues. Furthermore, there is a significant reduction in the activity of inducible nitric oxide synthase, TUNEL and arise in the expression of surfactant protein D in lung tissue of different pulmonary aspiration models with HBO therapy. It was concluded that HBO treatment might be beneficial in lung injury, therefore, shows potential for clinical use.

Delayed hyperbaric oxygen therapy for air emboli after open heart surgery: case report and review of a success story.

Science.gov (United States)

Niyibizi, Eva; Kembi, Guillaume Elyes; Lae, Claude; Pignel, Rodrigue; Sologashvili, Tornike

2016-12-05

The current case describes a rare diagnosis of iatrogenic air emboli after elective cardiopulmonary bypass that was successfully treated with delayed hyperbaric oxygen therapy, with good clinical evolution in spite of rare complications. A 35 years old male was admitted to the intensive care unit (ICU) for post-operative management after being placed on cardiopulmonary bypass (CPB) for an elective ventricular septal defect closure and aortic valvuloplasty. The patient initially presented with pathologically late awakening and was extubated 17 h after admission. Neurologic clinical status after extubation showed global aphasia, mental slowness and spatio-temporal disorientation. The injected cerebral CT scan was normal; the EEG was inconclusive (it showed metabolic encephalopathy without epileptic activity); and the cerebral MRI done 48 h after surgery showed multiple small subcortical acute ischemic lesions, mainly on the left fronto- parieto- temporo-occipital lobes. He was taken for hyperbaric oxygen therapy (HOT) over 54 h after cardiac surgery. The first session ended abruptly after 20 min when the patient suffered a generalised tonico-clonic seizure, necessitating a moderately rapid decompression, airway management, and antiepileptic treatment. In total, the patient received 7 HOT sessions over 6 days. He demonstrated full neurological recovery at 4 weeks and GOS (Glasgow Outcome Scale) of 5 out of 5 even after a long delay in initial management. Convulsions are a rare complication of HOT either due to reperfusion syndrome or hyperoxic toxicity and can be managed. Prior imaging by MRI or tympanic paracentesis (myringotomy) should not add further delay of treatment. HOT should be initiated upon late awakening and/or neurologic symptoms after CPB heart surgery, after exclusion of formal counter-indications, even if the delay exceeds 48 h.

Multi-stage low-pressure avalanche chamber

International Nuclear Information System (INIS)

Zanevskij, Yu.V.; Peshekhonov, V.D.; Smykov, L.P.

1985-01-01

A multi-stage avalanche-chamber filled with isobutane operating at the pressure of 6 torr is described. The chamber comprises an amplifying gap, drift gap and multiwire proportional chamber with interelectrode gaps equal to 4 mm. The anode plane of the proportional chamber is winded of wire 2 μm in diameter with 2 mm pitch. The cathode are winded orthogonally to anode wires of wire 50 μm in diameter with 1 mm pitch. Drift and preamplifier gaps are formed by grid electrodes made of wire 50 μm in diameter with dimension of the cell equal to 1x1 mm. Width of the drift gap is 5 mm, width of the preamplification gap is 3 or 9 mm. Coordinate data are removed from the cathodes of the proportional chamber by means of delay lines. Sensitive square of the chamber equals 240x180 mm. Gas gain coefficient is 3x10 6 at its square nonuniformity equal to approximately 3%. Spatial resolution by both coordinates equals 170 μm; spatial resolution for isotropic α-emitters located close to the preamplifier gap is equal to 500 μm

Monitored Drift Chambers in the ATLAS Detector

CERN Multimedia

Herten, G

Monitored Drift Chambers (MDT) are used in the ATLAS Detector to measure the momentum of high energy muons. They consist of drift tubes, which are filled with an Ar-CO2 gas mixture at 3 bar gas pressure. About 1200 drift chambers are required for ATLAS. They are up to 6 m long. Nevertheless the position of every wire needs to be known with a precision of 20 µm within a chamber. In addition, optical alignment sensors are required to measure the relative position of adjacent chambers with a precision of 30µm. This gigantic task seems impossible at first instance. Indeed it took many years of R&D to invent the right tools and methods before the first chamber could be built according to specifications. Today, at the time when 50% of the chambers have been produced, we are confident that the goal for ATLAS can be reached. The mechanical precision of the chambers could be verified with the x-ray tomograph at CERN. This ingenious device, developed for the MDT system, is able to measure the wire position insid...

Industrial development of neutron detectors, fission chambers, self powered detectors, ionization chambers

International Nuclear Information System (INIS)

Constans, H.; Coville, P.; Guerre, J.

1975-01-01

Reactor control requires the determination of neutron flux at all times. The needed characteristics lead to use of several types of detectors: boron lined counters, boron lined ionization chambers, fission ionization chambers and self powered detectors. The principle of the reaction involved the fabrication requirements, the different modes of utilization and the characteristics obtained are examined for each detector. The problem of electric connections in the active area has been solved by developing ''integrated cables'' [fr

The little holographic bubble chambers

International Nuclear Information System (INIS)

Herve, A.

1983-01-01

The lifetime study of the charmed particles has readvanced the idea to use holography for the little fast-cycle bubble chambers. A pilot experiment has been realised in 1982 with a little bubble chamber filled up with freon-115. 40000 holograms have been recorded [fr

Pelletron general purpose scattering chamber

International Nuclear Information System (INIS)

Chatterjee, A.; Kailas, S.; Kerekette, S.S.; Navin, A.; Kumar, Suresh

1993-01-01

A medium sized stainless steel scattering chamber has been constructed for nuclear scattering and reaction experiments at the 14UD pelletron accelerator facility. It has been so designed that several types of detectors, varying from small sized silicon surface barrier detectors to medium sized gas detectors and NaI detectors can be conveniently positioned inside the chamber for detection of charged particles. The chamber has been planned to perform the following types of experiments : angular distributions of elastically scattered particles, fission fragments and other charged particles, angular correlations for charged particles e.g. protons, alphas and fission fragments. (author). 2 figs

Blood lactate changes in men during graded workloads at normal atmospheric pressure (100 kPa) and under simulated caisson conditions (400 kPa).

Science.gov (United States)

Neubauer, B; Tetzlaff, K; Buslaps, C; Schwarzkopf, J; Bettinghausen, E; Rieckert, H

1999-05-01

A hyperbaric environment may influence lactate metabolism due to hyperoxia affecting biochemical pathways. The purpose of our study was to determine the blood lactate levels occurring at high workloads in a sample of professional divers under simulated caisson conditions. The ambient air pressure was equivalent to a diving depth of 30 m of seawater (400 kPa). A total of 23 healthy male subjects performed graded bicycle exercise in a dry hyperbaric chamber up to a maximum of 3.5 W kg(-1) body weight at normal (100 kPa) and elevated ambient air pressure (400 kPa). The blood lactate level and the heart rate were measured. In comparison with control conditions, the heart rate and the peripheral blood lactate level were significantly lower at depth for all workloads. The differences between the normobaric and hyperbaric lactate values may be explained by an overall improvement in lactate metabolism at elevated ambient pressure, especially in the working muscles and the organs responsible for the lactate reduction, i.e., the liver. The reduced heart rate may be an effect of the improved tissue oxygen supply at depth.

Radon diffusion chamber

International Nuclear Information System (INIS)

Pretzsch, G.; Boerner, E.; Lehmann, R.; Sarenio, O.

1986-01-01

The invention relates to the detection of radioactive gases emitting alpha particles like radon, thoron and their alpha-decaying daughters by means of a diffusion chamber with a passive detector, preferably with a solid state track detector. In the chamber above and towards the detector there is a single metallized electret with negative polarity. The distance between electret and detector corresponds to the range of the alpha particles of radon daughters in air at the most. The electret collects the positively charged daughters and functions as surface source. The electret increases the sensitivity by the factor 4

Multispecimen dual-beam irradiation damage chamber

International Nuclear Information System (INIS)

Packan, N.H.; Buhl, R.A.

1980-06-01

An irradiation damage chamber that can be used to rapidly simulate fast neutron damage in fission or fusion materials has been designed and constructed. The chamber operates in conjunction with dual Van de Graaff accelerators at ORNL to simulate a wide range of irradiation conditions, including pulsed irradiation. Up to six experiments, each with up to nine 3-mm disk specimens, can be loaded into the ultrahigh vacuum chamber. Specimen holders are heated with individual electron guns, and the temperature of each specimen can be monitored during bombardment by an infrared pyrometer. Three different dose levels may be obtained during any single bombardment, and the heavy-ion flux on each of the nine specimens can be measured independently with only a brief interruption of the beam. The chamber has been in service for nearly three years, during which time approximately 250 bombardments have been successfully carried out. An appendix contains detailed procedures for operating the chamber

Bi-cone vacuum chamber in the ISR

CERN Multimedia

CERN PhotoLab

1976-01-01

The "bi-cone" vacuum chamber in ISR intersection I-7, for experiment R702. Made from 0.28 mm thick titanium, it was at its time the most transparent chamber ever built. Ian Wilson is standing next to the chamber. See also 7609219.

Device for gamma-chamber transducer alignment

International Nuclear Information System (INIS)

Mirkhodzhaev, A.Kh.; Kuznetsov, N.K.; Ostryj, Yu.E.

1987-01-01

The device consists of the upper part of the gamma chamber pilar to which a rod is rigidly fastened with a disk of acrylic plastic moving freely on the opposite end. The disk is placed coaxially and is equal to the gamma chamber detector crystal. The device makes it possible to use ordinary medical couches covered with a porolone mattress when the gamma chamber detector is placed below

Bubble chamber: Omega production and decay

CERN Document Server

1973-01-01

This image is taken from one of CERN's bubble chambers and shows the decay of a positive kaon in flight. The decay products of this kaon can be seen spiraling in the magnetic field of the chamber. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that has been heated to boiling point.

The treatment of late radiation effects with hyperbaric oxygenation (HBO)

International Nuclear Information System (INIS)

Plafki, C.; Carl, U.M.; Glag, M.; Hartmann, K.A.

1998-01-01

Background: Late radiation injuries may impose a negative influence on the quality of life in the affected patients. In several entities, standardized treatment protocols are lacking. Hyperbaric oxygenation (HBO) has been shown to have beneficial effects in the treatment of late radiation sequelae. Material and methods: The basic principles of HBO are reviewed as well as clinical issues. Current study protocols are presented. Results: During HBO-therapy the patient breathes pure oxygen at pressures above 100 kPa. The oxygen solubility within the fluid phase of the blood is largely increased. Biological effects include an increased oxygen diffusibility, improved collagen synthesis and neoangiogenesis as well as an enhancement of antimicrobial defenses. By decreasing the capillary filtration pressure a reduction of edema becomes possible. HBO has been shown to prevent complications following surgery in irradiated tissues. Its efficacy as an adjunct in the treatment of osteonecroses in radiation patients could be demonstrated. In addition, the loss of osseointegrated implants in the maxillofacial bones of these patients could be significantly reduced. Further indications include soft tissue necroses, hemorrhagic cystitis and proctitis in tumor patients that have been treated by radiotherapy as part of a multimodality approach. Conclusions: HBO in the treatment of late radiation effects is still subject of investigation, but remarkable results have been reported. Optimized treatment protocols need to be determined in various entities. The rate of side effects is acceptable low. (orig.) [de

Investigation of endocrine and immunological response in fat tissue to hyperbaric oxygen administration in rats.

Science.gov (United States)

Şen, H; Erbağ, G; Ovali, M A; Öztopuz, R Ö; Uzun, M

2016-04-30

Though HBO treatment is becoming more common, the mechanism of action is not fully known. The positive effects of HBO administration on the inflammatory response is thought to be a possible basic mechanism. As a result, we aimed to research whether endocrine and immunological response of fat tissue changes in rats given HBO treatment model. This research was carried out on Wistar albino rats, they were treated with hyperbaric oxygen therapy. Their fatty tissue were taken from the abdomen, gene expression of the cytokines and adipokines were analyzed with Real time PCR method. When the gene expression of hormones and cytokines by fat tissue was examined, the leptin, visfatin, TNF-α, IL-1β and IL-10 levels in the HBO treatment group were statistically significantly increased compared to the control group (p=0.0313, p=0.0156, p=0.0156, p=0.0156, p=0.0313). In conclusion, in our study we identified that HBO administration affected the endochrinological functions of fat tissue.

Apparatus for reading and recharging condenser ionization chambers

International Nuclear Information System (INIS)

McCall, R.C.

1977-01-01

A metering circuit for a condenser ionization chamber is disclosed for simultaneously recharging the ionization chamber and reading out the amount of charge required to recharge the chamber. During the recharging process, the amount of charge necessary to recharge the ionization chamber capacitor is placed on an integrating capacitor in the metering apparatus. The resultant voltage across the integrating capacitor is a measure of the radiation to which the ionization chamber was exposed. 9 claims, 1 figure

Liquid-filled ionization chamber temperature dependence

Energy Technology Data Exchange (ETDEWEB)

Franco, L. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain)]. E-mail: luciaff@usc.es; Gomez, F. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Iglesias, A. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pardo, J. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pazos, A. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Pena, J. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain); Zapata, M. [Dpto. de Fisica de Particulas, Facultade de Fisica, Universidade de Santiago, Campus Sur S/N, 15782 Santiago de Compostela (Spain)

2006-05-10

Temperature and pressure corrections of the read-out signal of ionization chambers have a crucial importance in order to perform high-precision absolute dose measurements. In the present work the temperature and pressure dependences of a sealed liquid isooctane filled ionization chamber (previously developed by the authors) for radiotherapy applications have been studied. We have analyzed the thermal response of the liquid ionization chamber in a {approx}20 deg. C interval around room temperature. The temperature dependence of the signal can be considered linear, with a slope that depends on the chamber collection electric field. For example, a relative signal slope of 0.27x10{sup -2}K{sup -1} for an operation electric field of 1.67x10{sup 6}Vm{sup -1} has been measured in our detector. On the other hand, ambient pressure dependence has been found negligible, as expected for liquid-filled chambers. The thermal dependence of the liquid ionization chamber signal can be parametrized within the Onsager theory on initial recombination. Considering that changes with temperature of the detector response are due to variations in the free ion yield, a parametrization of this dependence has been obtained. There is a good agreement between the experimental data and the theoretical model from the Onsager framework.

Bubble chamber: antiproton annihilation

CERN Multimedia

1971-01-01

These images show real particle tracks from the annihilation of an antiproton in the 80 cm Saclay liquid hydrogen bubble chamber. A negative kaon and a neutral kaon are produced in this process, as well as a positive pion. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

Temperature Studies for ATLAS MDT BOS Chambers

CERN Document Server

Engl, A.; Biebel, O.; Mameghani, R.; Merkl, D.; Rauscher, F.; Schaile, D.; Ströhmer, R.

Data sets with high statistics taken at the cosmic ray facility, equipped with 3 ATLAS BOS MDT chambers, in Garching (Munich) have been used to study temperature and pressure effects on gas gain and drifttime. The deformation of a thermally expanded chamber was reconstructed using the internal RasNik alignment monitoring system and the tracks from cosmic data. For these studies a heating system was designed to increase the temperature of the middle chamber by up to 20 Kelvins over room temperature. For comparison the temperature effects on gas properties have been simulated with Garfield. The maximum drifttime decreased under temperature raise by -2.21 +- 0.08 ns/K, in agreement with the results of pressure variations and the Garfield simulation. The increased temperatures led to a linear increase of the gas gain of about 2.1% 1/K. The chamber deformation has been analyzed with the help of reconstructed tracks. By the comparison of the tracks through the reference chambers with these through the test chamber ...

Brookhaven National Laboratory's multiparticle spectrometer drift chamber system

International Nuclear Information System (INIS)

Etkin, A.; Kramer, M.A.

1979-01-01

A system of drift chambers is being built to replace the present spark chambers in the Brookhaven National Laboratory's Multiparticle Spectrometer. This system will handle a beam of approx. 3 million particles per second and have a resolution of 200 μm. A summary of the status of the chambers and the custom integrated circuits is presented. The data acquisition system is described. Prototype chambers have been built and tested with results that are consistent with the expected chamber properties

LEP vacuum chamber, cross-section

CERN Multimedia

CERN PhotoLab

1983-01-01

Cross-section of the final prototype for the LEP vacuum chamber. The elliptic main-opening is for the beam. The small channel to the left is for the cooling water, to carry away the heat deposited by the synchrotron radiation. The square channel to the right houses the Non-Evaporable Getter (NEG) pump. The chamber is made from extruded aluminium. Its outside is clad with lead, to stop the synchrotron radiation emitted by the beam. For good adherence between Pb and Al, the Al chamber was coated with a thin layer of Ni. Ni being slightly magnetic, some resulting problems had to be overcome. See also 8301153.

Note: Small anaerobic chamber for optical spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Chauvet, Adrien A. P., E-mail: adrien.chauvet@gmail.com; Chergui, Majed [Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, Station 6, 1015 Lausanne (Switzerland); Agarwal, Rachna; Cramer, William A. [Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907 (United States)

2015-10-15

The study of oxygen-sensitive biological samples requires an effective control of the atmosphere in which they are housed. In this aim however, no commercial anaerobic chamber is adequate to solely enclose the sample and small enough to fit in a compact spectroscopic system with which analysis can be performed. Furthermore, spectroscopic analysis requires the probe beam to pass through the whole chamber, introducing a requirement for adequate windows. In response to these challenges, we present a 1 l anaerobic chamber that is suitable for broad-band spectroscopic analysis. This chamber has the advantage of (1) providing access, via a septum, to the sample and (2) allows the sample position to be adjusted while keeping the chamber fixed and hermetic during the experiment.

Structural Analysis of Extended Plasma Focus Chamber

International Nuclear Information System (INIS)

Mohd Azhar Ahmad; Abdul Halim Baijan; Siti Aiasah Hashim

2016-01-01

Accelerator Development Centre (ADC) of Nuclear Malaysia intends to upgrade the plasma focus device. It involves the extension part placed on top of the existing plasma focus vacuum chamber. This extended vacuum chamber purposely to give an extra space in conducting experiments on the existing plasma focus chamber. The aim of upgrading the plasma focus device is to solve the limitation in research and analysis of sample due to its done in an open system that cause analysis of samples is limited and less optimal. This extended chamber was design in considering the ease of fabrication as well as durability of its structural. Thus, this paper discusses the structural analysis in term of pressure loading effect in extended chamber. (author)

Resultados iniciais da oxigenoterapia hiperbárica empacientes em lista de espera para o transplante hepático Preliminary results of hyperbaric oxygen therapy on patients on the waiting list for liver transplantation

Directory of Open Access Journals (Sweden)

Flávio Kreimer

2011-03-01

benefited with hyperbaric oxygen therapy. AIM: To evaluate clinical and laboratorial data regarding liver function in cirrhotic patients selected for liver transplantation, submitted to hyperbaric oxygen therapy. METHOD: A prospective interventional study was designed, wherein 10 patients were randomized amongst cirrhotic patients selected for liver transplantation. The ages ranged from 20 to 65 years, and all patients presented with a MELD score greater than 15. All patients were submitted to nine sessions of hyperbaric oxygen therapy, on alternated days with the duration of 60 minutes per session, with oxygen atmosphere of 100% and a 2,8 ATM pressure. Dependent parameters included were biochemical and hematologic laboratory values, evaluated before and after hyperbaric oxygen therapy sessions, besides clinical parameters, evaluated considering the Child-Turcotte-Pugh and the MELD scores. Statistical analysis was performed with SPSS (Statistcal Package for Social Sciences. RESULTS: Three patients (30% reported decrease in the number and intensity of encephalopathy. There were no cases of spontaneous bacterial peritonitis and gastrointestinal bleeding, and there were no increases on the severity of ascitis. Two patients reported improvement on pruritus, and four improvement on the general status for few weeks following hyperbaric oxygen sessions. CONCLUSION: Hyperbaric oxygen therapy may improve liver function in cirrhosis, and may help to control complications related to liver failure on the preoperative evaluation for liver transplantation.

Plasma chemistry in wire chambers

International Nuclear Information System (INIS)

Wise, J.

1990-05-01

The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55 Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

Wire chamber degradation at the Argonne ZGS

International Nuclear Information System (INIS)

Haberichter, W.; Spinka, H.

1986-01-01

Experience with multiwire proportional chambers at high rates at the Argonne Zero Gradient Synchrotron is described. A buildup of silicon on the sense wires was observed where the beam passed through the chamber. Analysis of the chamber gas indicated that the density of silicon was probably less than 10 ppM

Drift chamber vertex detectors for SLC/LEP

Energy Technology Data Exchange (ETDEWEB)

Hayes, K G

1988-03-01

Factors influencing the design of drift chamber vertex detectors for SLC and LEP are discussed including global strategy, chamber gas, cell design, and signal processing. The designs of the vertex chambers for the L3 and OPAL experiments at LEP and the Mark II experiment at the SLC are described.

Radon-daughter chamber instrumentation system reference manual

International Nuclear Information System (INIS)

Showalter, R.; Johnson, L.

1985-01-01

The radon-daughter chamber instrumentation system collects environmental data from the radon-daughter chamber. These data are then recorded on a Tandberg system tape cartridge and transmitted to the HP-1000 computer for processing. Generators which inject radon and condensation nuclei into the chamber are also included with the instrumentation system

Nuclear design considerations for Z-IFE chambers

Energy Technology Data Exchange (ETDEWEB)

Meier, W.R. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States)]. E-mail: meier5@llnl.gov; Schmitt, R.C. [Bettis Atomic Power Laboratory, Pittsburgh, PA 15203 (United States); Abbott, R.P. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States); Latkowski, J.F. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States); Reyes, S. [Lawrence Livermore National Laboratory, P.O. Box 808, L-641, Livermore, CA 94551 (United States)

2006-02-15

Z-pinch driven IFE (Z-IFE) requires the design of a repetitive target insertion system that allows coupling of the pulsed power to the target with adequate standoff, and a chamber that can withstand blast and radiation effects from large yield targets. The present strategy for Z-IFE is to use high yield targets ({approx}2-3 GJ/shot), low repetition rate per chamber ({approx}0.1 Hz), and 10 chambers per power plant. In this study, we propose an alternative power plant configuration that uses very high yield targets (20 GJ/shot) in a single chamber operating at 0.1 Hz. A thick-liquid-wall chamber is proposed to absorb the target emission (X-rays, debris and neutrons) and mitigate the blast effects on the chamber wall. The target is attached to the end of a conical shaped recyclable transmission line (RTL) made from a solid coolant (e.g., frozen flibe), or a material that is easily separable from the coolant (e.g., steel). The RTL/target assembly is inserted through a single opening at the top of the chamber for each shot. This study looks at the RTL material choice from a safety and environmental point of view. Materials were assessed according to waste disposal rating (WDR) and contact dose rate (CDR). Neutronics calculations, using the TART2002 Monte Carlo code from Lawrence Livermore National Laboratory (LLNL), were performed for the RTL and Z-IFE chamber, and key results reported here.

"Flat-Fish" Vacuum Chamber

CERN Multimedia

CERN PhotoLab

1978-01-01

The picture shows a "Flat-Fish" vacuum chamber being prepared in the ISR workshop for testing prior to installation in the Split Field Magnet (SFM) at intersection I4. The two shells of each part were hydroformed from 0.15 mm thick inconel 718 sheet (with end parts in inconel 600 for easier manual welding to the arms) and welded toghether with two strips which were attached by means of thin stainless steel sheets to the Split Field Magnet poles in order to take the vertical component of the atmospheric pressure force. This was the thinnest vacuum chamber ever made for the ISR. Inconel material was chosen for its high elastic modulus and strenght at chamber bake-out temperature. In this picture the thin sheets transferring the vertical component of the atmosferic pressure force are attached to a support frame for testing. See also 7712182, 7712179.

PWCs and drift chambers at ISABELLE

International Nuclear Information System (INIS)

Okuno, H.; Teramoto, Y.; Wheeler, C.D.

1978-01-01

Rate effects in proportional chambers and drift chambers are addressed first. The widely used high-gas-gain chambers would have impaired performance at ISABELLE data rates. Improvement can be expected with lower gas gain, and this possibility is investigated with respect to position and time resolution. Results on chamber lifetime are summarized; space-charge effects, gain saturation, and radiation hardness of electronics are considered. The resolution of drift chambers is discussed in some detail; time resolution, double pulse resolution, and momentum resolution and multiple scattering are included. The expected high multiplicity of tracks from a single event, the high event rates, and the requirement for low gas gain necessitate revision of the methods for measuring the second coordinate. Known methods of two-dimensional point localization are summarized according to spatial accuracy, electronics requirements, and multihit capability. Delay lines, charge division, and cathode strips are considered. Particle identification by means of measurement of the relativistic rise of energy loss by conventional and unconventional means was investigated. 32 references, 3 figures, 4 tables

Improved climatic chamber for desiccation simulation

Directory of Open Access Journals (Sweden)

Lozada Catalina

2016-01-01

Full Text Available The climatic chamber at the Universidad de Los Andes was improved for modeling desiccation in soil layers. This chamber allows the measurement of different environmental variables. In this research, evaporation tests were conducted in water imposing boundary conditions for drying, and then these tests were performed in a soil layer. The soil was prepared from a slurry state and was drying controlling the temperature, the infrared radiation, the wind velocity, and the relative humidity. In the first part of this paper, a description of the climatic chamber, operation ranges and theoretical work principles of the climatic chamber are presented. Then, the second part shows the results for desiccation in water and soil. The desiccation tests performed with the climatic chamber allow simulating all environmental conditions accurately during drying coupling the effect of all environmental variables. As a result, the evaporation rate increases with infrared radiation in soil and water. The rate at the beginning of the desiccation tests in clays is the same as in water. However, this evaporation rate decreases as the soil becomes desiccated.

Effects of hyperbaric oxygen and irradiation on experimental skin flaps in rats

International Nuclear Information System (INIS)

Nemiroff, P.M.; Merwin, G.E.; Brant, T.; Cassisi, N.J.

1985-01-01

This study investigated the effects of hyperbaric oxygen (HBO) and irradiation (RT) on experimental skin flaps in rats under varying conditions. Animals were assigned at random to 1 of 15 groups that represented all possible ordering effects of HBO, RT, and flap, as well as controls that included flap-only, RT-only, and HBO-only groups. Cranially based skin flaps measuring 3 x 9 cm were elevated on the dorsum. The surviving length was evaluated with fluorescein dye 7 days after the operation. Depending on the treatment condition, HBO was given either 48 hours or 24 hours before flap elevation, or within 4 hours or 48 hours after flap elevation. Rats receiving RT ( 60 Co) were given a single dose of 1000 rads to the dorsum. Results showed that all groups receiving HBO within 4 hours after flap elevation had significantly greater flap survival length, with as much as a 22% greater length of surviving flap. HBO given 48 hours before flap elevation also significantly improved flap survival over controls. RT appeared to have no immediate significant effect on flap survival. However, rats receiving RT, regardless of other factors, gained significantly less weight than did controls. Findings clearly indicate that, to be effective, HBO needs to be given as soon after surgery as possible

Mixed field dosimetry with the twin chamber technique

International Nuclear Information System (INIS)

Burger, G.; Maier, E.

1974-04-01

For the separate dosimetry of the neutron- and gamma-component in a mixed beam it is principally possible to use two ionization chambers with different ratios of neutron- to gamma sensitivity. Several authors proposed for this purpose the use of a homogenious TE-chamber filled with the TE-gas and of a carbon-chamber filled with CO 2 -gas. This chamber combination is also commercially available in several countries. The chambers are normally equipped with a continuous gas-flow provision and with a waterproof-housing for the use within liquid phantoms. The application of such chambers for mixed field dosimetry in the intercomparison project of the ICRU at the RARAF-facility in Brookhaven (International Neutron Dosimetry Intercomparison - INDI) is described. (orig./HP) [de

Drift chamber tracking with neural networks

International Nuclear Information System (INIS)

Lindsey, C.S.; Denby, B.; Haggerty, H.

1992-10-01

We discuss drift chamber tracking with a commercial log VLSI neural network chip. Voltages proportional to the drift times in a 4-layer drift chamber were presented to the Intel ETANN chip. The network was trained to provide the intercept and slope of straight tracks traversing the chamber. The outputs were recorded and later compared off line to conventional track fits. Two types of network architectures were studied. Applications of neural network tracking to high energy physics detector triggers is discussed

Making MUSIC: A multiple sampling ionization chamber

International Nuclear Information System (INIS)

Shumard, B.; Henderson, D.J.; Rehm, K.E.; Tang, X.D.

2007-01-01

A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction

Making MUSIC: A multiple sampling ionization chamber

Science.gov (United States)

Shumard, B.; Henderson, D. J.; Rehm, K. E.; Tang, X. D.

2007-08-01

A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the (α, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for (α, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only (α, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. × 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the (α, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the (α, p) reaction to reach the anode segment below the reaction.

Making MUSIC: A multiple sampling ionization chamber

Energy Technology Data Exchange (ETDEWEB)

Shumard, B. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)]. E-mail: shumard@phy.anl.gov; Henderson, D.J. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Rehm, K.E. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States); Tang, X.D. [Argonne National Laboratory, Building 203 H-113, Argonne, IL 60439 (United States)

2007-08-15

A multiple sampling ionization chamber (MUSIC) was developed for use in conjunction with the Atlas scattering chamber (ATSCAT). This chamber was developed to study the ({alpha}, p) reaction in stable and radioactive beams. The gas filled ionization chamber is used as a target and detector for both particles in the outgoing channel (p + beam particles for elastic scattering or p + residual nucleus for ({alpha}, p) reactions). The MUSIC detector is followed by a Si array to provide a trigger for anode events. The anode events are gated by a gating grid so that only ({alpha}, p) reactions where the proton reaches the Si detector result in an anode event. The MUSIC detector is a segmented ionization chamber. The active length of the chamber is 11.95 in. and is divided into 16 equal anode segments (3.5 in. x 0.70 in. with 0.3 in. spacing between pads). The dead area of the chamber was reduced by the addition of a Delrin snout that extends 0.875 in. into the chamber from the front face, to which a mylar window is affixed. 0.5 in. above the anode is a Frisch grid that is held at ground potential. 0.5 in. above the Frisch grid is a gating grid. The gating grid functions as a drift electron barrier, effectively halting the gathering of signals. Setting two sets of alternating wires at differing potentials creates a lateral electric field which traps the drift electrons, stopping the collection of anode signals. The chamber also has a reinforced mylar exit window separating the Si array from the target gas. This allows protons from the ({alpha}, p) reaction to be detected. The detection of these protons opens the gating grid to allow the drift electrons released from the ionizing gas during the ({alpha}, p) reaction to reach the anode segment below the reaction.

Simple Cloud Chambers Using Gel Ice Packs

Science.gov (United States)

Kamata, Masahiro; Kubota, Miki

2012-01-01

Although cloud chambers are highly regarded as teaching aids for radiation education, school teachers have difficulty in using cloud chambers because they have to prepare dry ice or liquid nitrogen before the experiment. We developed a very simple and inexpensive cloud chamber that uses the contents of gel ice packs which can substitute for dry…

An experimental propane bubble chamber

International Nuclear Information System (INIS)

Rogozinski, A.

1957-01-01

Describes a propane bubble chamber 10 cm in diameter and 5 cm deep. The body of the chamber is in stainless steel, and it has two windows of polished hardened glass. The compression and decompression of the propane are performed either through a piston in direct contact with the liquid, or by the action on the liquid, through a triple-mylar-Perbunan membrane, of a compressed gas. The general and also optimum working conditions of the chamber are described, and a few results are given concerning, in particular, the tests of the breakage-resistance of the windows and the measurements of the thermal expansion of the compressibility isotherm for the propane employed. (author) [fr

Very high intensity reaction chamber design

International Nuclear Information System (INIS)

Devaney, J.J.

1975-09-01

The problem of achieving very high intensity irradiation by light in minimal regions was studied. Three types of irradiation chamber are suggested: the common laser-reaction chamber, the folded concentric or near-concentric resonator, and the asymmetric confocal resonator. In all designs the ratio of high-intensity illuminated volume to other volume is highly dependent (to the 3 / 2 power) on the power and fluence tolerances of optical elements, primarily mirrors. Optimization of energy coupling is discussed for the common cavity. For the concentric cavities, optimization for both coherent and incoherent beams is treated. Formulae and numerical examples give the size of chambers, aspect ratios, maximum pass number, image sizes, fluences, and the like. Similarly for the asymmetric confocal chamber, formulae and numerical examples for fluences, dimensions, losses, and totally contained pass numbers are given

Liquid ionization chambers for LET determination

DEFF Research Database (Denmark)

Kaiser, Franz-Joachim; Bassler, Niels; Tölli, Heikki

Liquid ionization chambers [1] (LICs) have have been used in the last decades as background dosemeters. Since a few years LICs are also commercially available for dosimetry and are used for measurements of dose distributions where a high spatial distribution is necessary. Also in the last decades...... a differential equation applying several simplifications and approximations leading to discrepancies between theory and experiments [3]. The theory predicts the collection efficiency as a function of the electrical field and was applied for both air filled ionization chambers and liquid filled ionization...... chambers. For liquids the LET can be roughly deduced from the collection efficiency dependency on the electrical field inside a liquid ionization chambers [4] using an extrapolation method. We solved the fundamental differential equation again presented by Jaffe numerically, but now taking into account...

DORIOT CLIMATIC CHAMBERS

Data.gov (United States)

Federal Laboratory Consortium — The Doriot Climatic Chambers reproduce environmental conditions occurring anywhere around the world. They provide an invaluable service by significantly reducing the...

Practical electron dosimetry: a comparison of different types of ionization chambers

International Nuclear Information System (INIS)

Dohm, O.S.; Christ, G.

2002-01-01

Since Markus chambers are no longer recommended in the 1997 DIN 6800-2 version there are uncertainties as to the use of alternative chamber types for electron dosimetry. Therefore, we performed a comparison between different types of ionization chambers. In particular, the widespread Farmer and Roos chambers were compared with the Markus chamber for polarity effect, chamber-to-chamber variation, and deviations of the measured absorbed dose relative to the value obtained with the Roos chamber (which is regarded as an ideal Bragg-Gray-chamber). The perturbation correction factor at 60 Co radiation was determined experimentally as 1,029 ± 0,5% (Roos chamber) and 1,018 ± 0,5% (Markus chamber) for the investigated plane-parallel chambers. In addition, we could show that the Roos chambers do not have a larger chamber-to-chamber variation than the Farmer chambers. Likewise, our results suggest that Farmer chambers could be used for electron energies above 6 MeV. (orig.) [de

Sensitivity of gaseous xenon ionisation chambers (1961)

International Nuclear Information System (INIS)

Schuhl, C.

1960-01-01

It seems advantageous to fill an ionization chamber with xenon gas when this chamber is used for measuring a low intensity and high energy electron or positron beam, or monitoring a gamma beam. In the study of 5 to 50 MeV electrons, xenon allows for the ionization chamber yield, an improvement of a factor 4,5. (author) [fr

Ionization chamber correction factors for MR-linacs.

Science.gov (United States)

Pojtinger, Stefan; Dohm, Oliver Steffen; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-07

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B . The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0-2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Ionization chamber correction factors for MR-linacs

Science.gov (United States)

Pojtinger, Stefan; Steffen Dohm, Oliver; Kapsch, Ralf-Peter; Thorwarth, Daniela

2018-06-01

Previously, readings of air-filled ionization chambers have been described as being influenced by magnetic fields. To use these chambers for dosimetry in magnetic resonance guided radiotherapy (MRgRT), this effect must be taken into account by introducing a correction factor k B. The purpose of this study is to systematically investigate k B for a typical reference setup for commercially available ionization chambers with different magnetic field strengths. The Monte Carlo simulation tool EGSnrc was used to simulate eight commercially available ionization chambers in magnetic fields whose magnetic flux density was in the range of 0–2.5 T. To validate the simulation, the influence of the magnetic field was experimentally determined for a PTW30013 Farmer-type chamber for magnetic flux densities between 0 and 1.425 T. Changes in the detector response of up to 8% depending on the magnetic flux density, on the chamber geometry and on the chamber orientation were obtained. In the experimental setup, a maximum deviation of less than 2% was observed when comparing measured values with simulated values. Dedicated values for two MR-linac systems (ViewRay MRIdian, ViewRay Inc, Cleveland, United States, 0.35 T/ 6 MV and Elekta Unity, Elekta AB, Stockholm, Sweden, 1.5 T/7 MV) were determined for future use in reference dosimetry. Simulated values for thimble-type chambers are in good agreement with experiments as well as with the results of previous publications. After further experimental validation, the results can be considered for definition of standard protocols for purposes of reference dosimetry in MRgRT.

Bubble chamber: Omega production and decay

CERN Multimedia

1973-01-01

This image is of real particle tracks taken from the CERN 2 m liquid hydrogen bubble chamber and shows the production and decay of a negative omega particle. A negative kaon enters the chamber which decays into many particles, including a negative omega that travels a short distance before decaying into more particles. The invention of bubble chambers in 1952 revolutionized the field of particle physics, allowing real tracks left by particles to be seen and photographed by expanding liquid that had been heated to boiling point.

Evaluation of carbon dioxide dissipation within a euthanasia chamber.

Science.gov (United States)

Djoufack-Momo, Shelly M; Amparan, Ashlee A; Grunden, Beverly; Boivin, Gregory P-

2014-07-01

CO₂ euthanasia is used widely for small laboratory animals, such as rodents. A common necessity in many animal research facilities is to euthanize mice in sequential batches. We assessed the effects of several variables on the time it took for CO₂ to dissipate within a chamber. Using standard euthanasia time, changes in flow rate were compared between a slow 15% fill rate for 7 min, and a slow 15% followed by a rapid 50% filling for a total of 5 min. Additional variables assessed included the effects of opening the lid after the completion of chamber filling, turning the chamber over after completion of filling, and the use and removal of a cage from within the chamber. For all trials, CO₂ levels in the chambers peaked between 50% and 80%. After the gas was turned off, the concentration of CO₂ dropped to below 10% COv within 2 min, except when the lid was left on the chamber, where concentration levels remained above 10% after 20 min. CO₂ dissipation was significantly faster when the chamber was turned upside down after filling. Significant interaction effects occurred among the factors of cage presence within the chamber, flow rate, and chamber position. Only leaving the lid on the chamber had any practical implication for delaying CO₂ dissipation. We recommend that users allow 2 min for CO₂ to clear from the chamber before subsequent euthanasia procedures, unless the chamber is manipulated to increase the dissipation rate.

D0 central tracking chamber performance studies

International Nuclear Information System (INIS)

Pizzuto, D.

1991-12-01

The performance of the completed DO central tracking chamber was studied using cosmic rays at the State University of New York at Stony Brook. Also studied was a prototype tracking chamber identical in design to the completed DO tracking chamber. The prototype chamber was exposed to a collimated beam of 150 GeV pions at the Fermilab NWA test facility. Results indicate an RΦ tracking resolution compatible with the limitations imposed by physical considerations, excellent 2 track resolution, and a high track reconstruction efficiency along with a good rejection power against γ → e + e - events

Argus drift chamber

Energy Technology Data Exchange (ETDEWEB)

Danilov, M; Nagovizin, V; Hasemann, H; Michel, E; Schmidt-Parzefall, W; Wurth, R; Kim, P

1983-11-15

The ARGUS detector came into operation at the DORIS-II e/sup +/s/sup -/ storage ring at the end of 1982. Its two meter long drift chamber contains 5940 sense and 24588 field wires organized in uniform 18x18.8 mm/sup 2/ drift cells filling the whole volume. These cells form 36 layers, 18 of which provide stereo views. Each sense wire is equipped with a single hit TDC and ADC for coordinate and dE/dx measurements. The chamber is operated with propane to improve momentum and dE/dx resolution. The drift chamber design and initial performance are presented. With a very crude space-time relation approximation and without all the necessary corrections applied a spatial resolution of about 200 ..mu..m was obtained for half of the drift cell volume. Further corrections should improve this result. An intrinsic dE/dx resolution of 4.2% and an actual resolution of 5% were obtained for cosmic muons and also for Bhabha scattered electrons. An actual dE/dx resolution of 5.6% was obtained for pions from e/sup +/e/sup -/ annihilation data with almost no track selection. A relativistic rise of 30% was observed in good agreement with theory. The long-term stability is still to be investigated.

The wide gap resistive plate chamber

International Nuclear Information System (INIS)

Crotty, I.; Lamas Valverde, J.; Hatzifotiadou, D.; Williams, M.C.S.; Zichichi, A.

1995-01-01

The resistive plate chamber (RPC) has good time and position resolution; these factors (coupled to its simple construction) make it an attractive candidate for muon trigger systems at future colliders. However, operated in spark mode, the RPC has severe rate problems that make it unusable above 10 Hz/cm 2 . We have previously published our results concerning the operation of the RPC in spark and in avalanche mode; we have shown that the rate limit can be increased to 150 Hz/cm 2 if the RPC is operated in avalanche mode. Here, we discuss the performance of chambers with 6 and 8 mm gas gaps (compared to the more usual 2 mm gap). We outline the reasons for this choice, and also discuss anode versus cathode strip readout. We have measured the efficiency versus flux, and also show that an enhanced rate limit can be obtained if only a small region of the chamber is exposed to the beam (spot illumination). Finally we have tested the performance of chambers constructed with other materials for the resistiv e plate and compare it to chambers constructed with our preferred plastic, melamine laminate. (orig.)

HYLIFE-II reactor chamber design refinements

International Nuclear Information System (INIS)

House, P.A.

1994-06-01

Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li 2 BeF 4 ) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (>12 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GWe and 2 GWe reactor chamber are presented

Dilution refrigeration with multiple mixing chambers

International Nuclear Information System (INIS)

Coops, G.M.

1981-01-01

A dilution refrigerator is an instrument to reach temperatures in the mK region in a continuous way. The temperature range can be extended and the cooling power can be enlarged by adding an extra mixing chamber. In this way we obtain a double mixing chamber system. In this thesis the theory of the multiple mixing chamber is presented and tested on its validity by comparison with the measurements. Measurements on a dilution refrigerator with a circulation rate up to 2.5 mmol/s are also reported. (Auth.)

MDT Commissioning Procedures Guidelines for Certifying RFI Chambers

CERN Document Server

Beretta, M; Branchini, P; Kourkoumelis, C; Dubbert, J; Gazis, E N; Hertenberger, R; Hurst, P; Kojine, A; Lanza, A; Marin, A; Mockett, P; Petridou, C; Tskhadadze, E G; Valente, P; Wotschack, J; Xie, Y; Zhao, Z

2004-01-01

Aim of the document is the definition of a common set of guidelines and test procedures for commissioning the MDT chambers. Commissioning is different for Barrel and Endcap chambers. The former will be tested at a single chamber level before going to the ATLAS pit, ready for the last quick test before final installation, while the latter will be first tested at a single chamber level (phase one), then installed into the Small and Big Wheel sectors (SW and BW), tested after the integration (phase two) and transported to the ATLAS pit for final wheel installation. The present document concerns all tests, including those of phase two for Endcap chambers, but it is possible that some specific tests, at the moment not planned, will be implemented during the Endcap phase two commissioning. It is composed of three sections: 1 â€" Guidelines for checking chamber conformity, where the main rules for declaring that chambers conform to the reference drawings and requirements are described; 2 â€" Commissioning tests,...

Clinical evaluation in hyperbaric oxygen therapy by using computerized tomography

International Nuclear Information System (INIS)

Matsuda, Kazumi; Kobayashi, Eiki; Mihara, Tadahiro; Asakura, Tetsuhiko; Fujimoto, Toshiro; Fujimoto, Seijiro.

1982-01-01

Hyperbaric Oxygen Therapy (H.O.T. for abbreviation), accompanied by usual conservative therapy, was performed on 30 patients with cerebrovascular disturbances (cerebral infarction: 20 cases; hypertensive intracerebral hemorrhage: 10 cases). The clinical signs and symptoms, clinical courses, EEG findings, and CT findings and agter the H.O.T. were then compared before. Moreover, by analyzing the changes in the CT findings (the size and Hounsfield Number of the low-density area and the effect of contrast enhancement), the authors have attempted a clinical evaluation of H.O.T. The results are as follows: 1) Infarction group: There is a tendency to have more changes in the CT findings (reduction of the low-density area, decrease in the Hounsfield Number in the low-density portion, and changes in the effect of contrast enhancement) in the earlier H.O.T. - starting group. However, there was no definite relation between the changes in the CT findings and the clinical signs and symptoms. 2) Hypertensive intracerebral hemorrhage group: there was a tendency to have a reduction in the low-density area and an improvement in the clinical signs and symptoms in cases who had an early start of H.O.T. So far as investigating hemodynamic changes is concerned, there is a limit to the ability of investigation by means of CT scan. In future, we hope to establish methods by which if will be possible to detect the hemodynamic changes more exactly with respect to the clinical evaluation of H.O.T. (author)

Lifetime survivability of contaminated target-chamber optics

International Nuclear Information System (INIS)

Rainer, F.; Anderson, A.; Burnham, A.; Milam, D.; Turner, R.

1996-11-01

Target chambers used for Inertial Confinement Fusion (ICF) expose laser optics to a very hostile environment, not only from high-fluence laser irradiation but also x-ray irradiation and particulate debris from targets and chamber wall materials. Expendable debris shields provide the first line of defense to more costly optics upstream in the laser beam path to contaminants generated within the target chamber. However, the replacement of a large number of debris shields is also an expensive proposition so that extending their usable lifetime within the chamber is important. We have conducted tests to show that optics can both be cleaned and damaged by laser irradiation at 355 nm after being contaminated with potential chamber-wall materials such as B 4 C and Al 2 O 3 . Such optics can survive from one to hundreds of laser shots, depending on degree of contamination and laser fluence levels. Similarly, we have studied the survivability of optics that have been exposed to direct contamination from representative target materials irradiated in the target chamber. We have also studied the effects on optics that were not directly exposed to targets, yet received secondary exposure from the above directly-exposed samples

Adjunctive hyperbaric oxygen therapy in severe burns: Experience in Taiwan Formosa Water Park dust explosion disaster.

Science.gov (United States)

Chiang, I-Han; Chen, Shyi-Gen; Huang, Kun-Lun; Chou, Yu-Ching; Dai, Niann-Tzyy; Peng, Chung-Kan

2017-06-01

Despite major advances in therapeutic strategies for the management of patients with severe burns, significant morbidity and mortality is observed. Hyperbaric oxygen therapy (HBOT) increases the supply of oxygen to burn areas. The aim of this study was to determine whether HBOT is effective in the treatment of major thermal burns. On June 27, 2015 in New Taipei, Taiwan, a mass casualty disaster occurred as fire erupted over a large crowd, injuring 499 people. Fifty-three victims (20 women and 33 men) were admitted to Tri-Service General Hospital. Thirty-eight patients underwent adjunctive HBOT (HBOT group), and 15 patients received routine burn therapy (control group). Serum procalcitonin (PCT) level, a sepsis biomarker, was measured until it reached normal levels (burn care combined with adjunctive HBOT improves sepsis control compared with standard treatment without HBOT. Prospective studies are required to define the role of HBOT in extensive burns. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Vacuum Chamber for the Booster Bending Magnets

CERN Multimedia

CERN PhotoLab

1974-01-01

To minimize eddy currents, induced by the rising magnetic field, the chamber was made from thin stainless steel of high specific electric resistance. For mechanical stength, it was corrugated in a hydro-forming process. The chamber is curved, to follow the beam's orbital path. Under vacuum, the chamber tends to staighten, the ceramic spacer along half of its length keeps it in place (see also 7402458).

Construction and performance of large flash chambers

International Nuclear Information System (INIS)

Taylor, F.E.; Bogert, D.; Fisk, R.; Stutte, L.; Walker, J.K.; Wolfson, J.; Abolins, M.; Ernwein, J.; Owen, D.; Lyons, T.

1979-01-01

The construction and performance of 12' x 12' flash chambers used in a 340 ton neutrino detector under construction at Fermilab is described. The flash chambers supply digital information with a spatial resolution of 0.2'', and are used to finely sample the shower development of the reaction products of neutrino interactions. The flash chambers are easy and inexpensive to build and are electronically read out

The knife-edge chamber

International Nuclear Information System (INIS)

Barasch, E.F.; Bowcock, T.J.V.; Drew, M.M.; Elliott, S.M.; Lee, B.; McIntyre, P.M.; Pang, Y.; Popovic, M.; Smith, D.D.

1990-01-01

In this paper the design for a new technology for particle track detectors is described. Using standard IC fabrication techniques, a pattern of microscopic knife edges and field-shaping electrodes can be fabricated on a silicon substrate. The knife-edge chamber uniquely offers attractive performance for the track chambers required for SSC detectors, for which no present technology is yet satisfactory. Its features include: excellent radiation hardness (10 Mrad), excellent spatial resolution (∼20 μm), short drift time (20 ns), and large pulse height (1 mV)

Multiple chamber ionization detector

International Nuclear Information System (INIS)

Solomon, E.E.

1982-01-01

An ionization smoke detector employs a single radiation source in a construction comprising at least two chambers with a center or node electrode. The radioactive source is associated with this central electrode, and its positioning may be adjusted relative to the electrode to alter the proportion of the source that protrudes into each chamber. The source may also be mounted in the plane of the central electrode, and positioned relative to the center of the electrode. The central electrode or source may be made tiltable relative to the body of the detector

Ionization chamber gradient effects in nonstandard beam configurations

International Nuclear Information System (INIS)

Bouchard, Hugo; Seuntjens, Jan; Carrier, Jean-Francois; Kawrakow, Iwan

2009-01-01

Purpose: For the purpose of nonstandard beam reference dosimetry, the current concept of reporting absorbed dose at a point in water located at a representative position in the chamber volume is investigated in detail. As new nonstandard beam reference dosimetry protocols are under development, an evaluation of the role played by the definition of point of measurement could lead to conceptual improvements prior to establishing measurement procedures. Methods: The present study uses the current definition of reporting absorbed dose to calculate ionization chamber perturbation factors for two cylindrical chamber models (Exradin A12 and A14) using the Monte Carlo method. The EGSnrc based user-code EGS lowbar chamber is used to calculate chamber dose responses of 14 IMRT beams chosen to cause considerable dose gradients over the chamber volume as previously used by Bouchard and Seuntjens [''Ionization chamber-based reference dosimetry of intensity modulated radiation beams,'' Med. Phys. 31(9), 2454-5465 (2004)]. Results: The study shows conclusively the relative importance of each physical effect involved in the nonstandard beam correction factors of 14 IMRT beams. Of all correction factors involved in the dosimetry of the beams studied, the gradient perturbation correction factor has the highest magnitude, on average, 11% higher compared to reference conditions for the Exradin A12 chamber and about 5% higher for the Extradin A14 chamber. Other perturbation correction factors (i.e., P wall , P stem , and P cel ) are, on average, less than 0.8% different from reference conditions for the chambers and beams studied. The current approach of reporting measured absorbed dose at a point in water coinciding with the location of the centroid of the chamber is the main factor responsible for large correction factors in nonstandard beam deliveries (e.g., intensity modulated radiation therapy) reported in literature. Conclusions: To reduce or eliminate the magnitude of

21 CFR 866.2120 - Anaerobic chamber.

Science.gov (United States)

2010-04-01

... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2120 Anaerobic chamber. (a) Identification. An anaerobic chamber is a device intended for medical purposes to maintain an anaerobic (oxygen...

A small flat fission chamber

International Nuclear Information System (INIS)

Li Yijun; Wang Dalun; Chen Suhe

1999-01-01

With fission materials of depleted uranium, natural uranium, enriched uranium, 239 Pu, and 237 Np, the authors have designed and made a series of small flat fission chamber. The authors narrated the construction of the fission chamber and its technological process of manufacture, and furthermore, the authors have measured and discussed the follow correct factor, self-absorption, boundary effect, threshold loss factor, bottom scatter and or so

Lifetime tests for MAC vertex chamber

International Nuclear Information System (INIS)

Nelson, H.

1986-01-01

A vertex chamber for MAC was proposed in fall 1983 to increase precision in the measurement of the B hadron and tau lepton lifetimes. The chamber had to be placed within the existing central drift chamber, making access for repairs difficult and costly. Therefore for detector elements thin-walled aluminized mylar drift tubes (straws) were used because of their simplicity and robustness. The diameter of the drift tubes was 6.9 mm. The radial extent of the proposed chamber was from 3 cm to 10 cm, the inner wall of the central drift. It was clear that radiation levels, from synchrotron x-rays and overfocussed electrons, were potentially high. Since the drift distance is short in the straws, it was desirable to operate them at the highest possible gas gain, to achieve the best spatial resolution. There was a likelihood of drawing large currents in the chamber and thus causing radiation damage. Therefore a study of radiation hardness under the conditions of their proposed design was undertaken. In tests, argon-hydrocarbon mixtures consistently became unusable at ∼0.05 C/cm collected charge, due to anode buildup. Argon-CO 2 mixtures, while underquenched, were operational to 0.25 C/cm, at which point loss of cathode material became intolerable. Argon-xenon-CO 2 proved to be quenched as well as argon-hydrocarbons, but was limited by cathode damage. The MAC vertex chamber has operated at a distance of 4.6 cm from the e + e - interaction point at PEP for two years and has shown no aging effects

Acoustic-Levitation Chamber

Science.gov (United States)

Barmatz, M. B.; Granett, D.; Lee, M. C.

1984-01-01

Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

MultiModality Surgical and Hyperbaric Management of Mandibular Osteoradionecrosis

International Nuclear Information System (INIS)

Freiberger, John J.; Yoo, David S.; Lisle Dear, Guy de; McGraw, Thomas A.; Blakey, George H.; Padilla Burgos, Rebecca; Kraft, Kevin; Nelson, John W.; Moon, Richard E.; Piantadosi, Claude A.

2009-01-01

Purpose: To elucidate long-term outcomes in 65 consecutive patients meeting a uniform definition of mandibular osteoradionecrosis (ORN) treated with multimodality therapy including hyperbaric oxygen (HBO). Methods and Materials: Pretreatment, post-treatment and long-term follow-up of mandibular lesions with exposed bone were ranked by a systematic review of medical records and patient telephone calls. The ranking system was based on lesion diameter and number plus disease progression. Changes from pretreatment to post-treatment and follow-up were analyzed by Wilcoxon signed-rank tests. Improved wound survival, measured by time to relapse, defined as any less favorable rank after HBO treatment, was assessed by Kaplan-Meier analysis. Results: In all, 57 cases (88%) resolved or improved by lesion grade or progression and evolution criteria after HBO (p < 0.001). Four patients healed before surgery after HBO alone. Of 57 patients who experienced improvement, 41 had failed previous nonmultimodality therapy for 3 months and 26 for 6 months or more. A total of 43 patients were eligible for time-to-relapse survival analysis. Healing or improvement lasted a mean duration of 86.1 months (95% confidence interval [95% CI], 64.0-108.2) in nonsmokers (n = 20) vs. 15.8 months (95% CI, 8.4-23.2) in smokers (n = 14) versus 24.2 months (95% CI, 15.2-33.2) in patients with recurrent cancer (n = 9) (p = 0.002 by the log-rank method). Conclusions: Multimodality therapy using HBO is effective for ORN when less intensive therapies have failed. Although the healing rate in similarly affected patients not treated with HBO is unknown, the improvements seen with peri-operative HBO were durable provided that the patients remained cancer free and abstained from smoking.

Polarity effects and apparent ion recombination in microionization chambers

Energy Technology Data Exchange (ETDEWEB)

Miller, Jessica R., E-mail: miller@humonc.wisc.edu [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 and Department of Human Oncology, University of Wisconsin-Madison, Madison, Wisconsin 53792 (United States); Hooten, Brian D. [Standard Imaging, Middleton, Wisconsin 53562 (United States); Micka, John A.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States)

2016-05-15

Purpose: Microchambers demonstrate anomalous voltage-dependent polarity effects. Existing polarity and ion recombination correction factors do not account for these effects. As a result, many commercial microchamber models do not meet the specification of a reference-class ionization chamber as defined by the American Association of Physicists in Medicine. The purpose of this investigation is to determine the cause of these voltage-dependent polarity effects. Methods: A series of microchamber prototypes were produced to isolate the source of the voltage-dependent polarity effects. Parameters including ionization-chamber collecting-volume size, stem and cable irradiation, chamber assembly, contaminants, high-Z materials, and individual chamber components were investigated. Measurements were performed with electrodes coated with graphite to isolate electrode conductivity. Chamber response was measured as the potential bias of the guard electrode was altered with respect to the collecting electrode, through the integration of additional power supplies. Ionization chamber models were also simulated using COMSOL Multiphysics software to investigate the effect of a potential difference between electrodes on electric field lines and collecting volume definition. Results: Investigations with microchamber prototypes demonstrated that the significant source of the voltage-dependent polarity effects was a potential difference between the guard and collecting electrodes of the chambers. The voltage-dependent polarity effects for each prototype were primarily isolated to either the guard or collecting electrode. Polarity effects were reduced by coating the isolated electrode with a conductive layer of graphite. Polarity effects were increased by introducing a potential difference between the electrodes. COMSOL simulations further demonstrated that for a given potential difference between electrodes, the collecting volume of the chamber changed as the applied voltage was altered

Repair of isolated double-chambered right ventricle | El Kouache ...

African Journals Online (AJOL)

The finding of a double-chambered right ventricle (DCRV) is exceptionally rare as an isolated anomaly. It is a congenital cardiac anomaly in which the right ventricle is separated into two chambers, a proximal highpressure chamber and a distal low-pressure chamber, by anomalous muscles or fibrous tissues in the right ...

Vacuum chamber 'bicone'

CERN Multimedia

1977-01-01

This chamber is now in the National Museum of History and Technology, Smithsonian Institution, Washington, DC, USA, where it was exposed in an exhibit on the History of High Energy Accelerators (1977).

Does hyperbaric oxygen treatment have the potential to increase salivary flow rate and reduce xerostomia in previously irradiated head and neck cancer patients? A pilot study

DEFF Research Database (Denmark)

Forner, Lone; Hansen, Ole Hyldegaard; von Brockdorff, Annet Schack

2011-01-01

in irradiated head and neck cancer patients. Eighty patients eligible for HBO treatment on the indication of prevention/treatment of osteoradionecrosis or soft tissue radiation injury were consecutively sampled, of whom 45 had hyposalivation (i.e. unstimulated whole saliva (UWS) flow rate......Irradiated head and neck cancer survivors treated in the Hyperbaric Oxygen (HBO) Unit, Copenhagen University Hospital, spontaneously reported improvement of radiation-induced dry mouth feeling. The aim of this pilot study was to evaluate salivary flow rate and xerostomia before and after HBO...

Study on target interactions in emulsion chamber - Brasil-Japan emulsion chamber collaboration

Science.gov (United States)

Ballester, M.; Santos, C.; Bellandi Filho, J.; Chinellato, J. A.; Dobrigkeit, C.; Lattes, C. M. G.; Marques, A.; Menon, M. J.; Navia, C. E.; Sawayanagi, K.

Experimental results are presented from observations of 80 target nuclear interactions where the total gamma-ray energy is greater than or equal to 20 TeV. Evidence is presented for the existence of two types of interactions; the interpretation is given on the basis of a fire-ball model. Two-story emulsion chambers exposed at Mount Chacaltaya, in Bolivia (5,220 m above sea level), are used. Gamma rays from nuclear interactions in the target layer of petroleum pitch (1/3 of the nuclear mean free path in thickness) are detected through observations of the electron showers generated by them in the lower chamber

Climate chamber for environmentally controlled laboratory airflow experiments.

Science.gov (United States)

Even-Tzur, Nurit; Zaretsky, Uri; Grinberg, Orly; Davidovich, Tomer; Kloog, Yoel; Wolf, Michael; Elad, David

2010-01-01

Climate chambers have been widely used in in vitro and in vivo studies which require controlled environmental temperature and humidity conditions. This article describes a new desktop climate chamber that was developed for application of respiratory airflows on cultured nasal epithelial cells (NEC) under controlled temperature and humidity conditions. Flow experiments were performed by connecting the climate chamber to an airflow generator via a flow chamber with cultured NEC. Experiments at two controlled climate conditions, 25 degrees C and 40% relative humidity (RH) and 37 degrees C and 80%RH, were conducted to study mucin secretion from the cultures inresponse to the flow. The new climate chamber is a relatively simple and inexpensive apparatus which can easily be connected to any flow system for climate controlled flow experiments. This chamber can be easily adjusted to various in vitro experiments, as well as to clinical studies with animals or human subjects which require controlled climate conditions.

Investigation of a multiwire proportional chamber

International Nuclear Information System (INIS)

Konijn, J.

1976-01-01

The article discusses some aspects of a prototype multiwire proportional chamber for electron detection located at IKO in Amsterdam, i.e. voltage, counting rates, noise and gas mixture (argon, ethylene bromide). The efficiency and performance of the chamber have been investigated and an error analysis is given

Triangular tube proportional wire chamber system

Energy Technology Data Exchange (ETDEWEB)

Badtke, D H; Bakken, J A; Barnett, B A; Blumenfeld, B J; Chien, C Y; Madansky, L; Matthews, J A.J.; Pevsner, A; Spangler, W J [Johns Hopkins Univ., Baltimore, MD (USA); Lee, K L [California Univ., Berkeley (USA). Lawrence Berkeley Lab.

1981-10-15

We report on the characteristics of the proportional tube chamber system which has been constructed for muon identification in the PEP-4 experiment at SLAC. The mechanical and electrical properties of the extruded aluminum triangular tubes allow these detectors to be used as crude drift chambers.

The Mark III vertex chamber and prototype test results

International Nuclear Information System (INIS)

Grab, C.

1987-07-01

A vertex chamber has been constructed for use in the Mark III experiment. The chamber is positioned inside the current main drift chamber and will be used to trigger data collection, to aid in vertex reconstruction, and to improve the momentum resolution. This paper discusses the chamber's construction and performance and tests of the prototype

The OPAL vertex drift chamber

International Nuclear Information System (INIS)

Carter, J.R.; Elcombe, P.A.; Hill, J.C.; Roach, C.M.; Armitage, J.C.; Carnegie, R.K.; Estabrooks, P.; Hemingway, R.; Karlen, D.; McPherson, A.; Pinfold, J.; Roney, J.M.; Routenburg, P.; Waterhouse, J.; Hargrove, C.K.; Klem, D.; Oakham, F.G.; Carter, A.A.; Jones, R.W.L.; Lasota, M.M.B.; Lloyd, S.L.; Pritchard, T.W.; Wyatt, T.R.

1990-01-01

A high precision vertex drift chamber has been installed in the OPAL experiment at LEP. The design of the chamber and the associated readout electronics is described. The performance of the system has been studied using cosmic ray muons and the results of these studies are presented. A space resolution of 50 μm in the drift direction is obtained using the OPAL central detector gas mixture at 4 bar. (orig.)

Use of hyperbaric oxygen therapy in T2 diabetics with pelvic lesions. Clinical experience

Directory of Open Access Journals (Sweden)

R.E. Castro-López

2017-10-01

Full Text Available Background: The World Health Organisation indicates that the number of people with type 2 diabetes mellitus is more than 366 million and is expected to increase to 552 million by 2030, i.e., 8.3% of the total adult population. Each year, 14.9% of patients with this disease experience plantar ulcers, which in most cases are resistant to standard treatments. Of these, 15–20% require radical amputation within five years of diagnosis. Material and methods: This is a retrospective study reviewing the records of patients with type 2 diabetes mellitus and complications from lower limb injuries. We selected 220 records of patients with type 2 diabetes mellitus and lower limb injuries, undergoing hyperbaric oxygen therapy. We grouped wounds according to the Wagner Grading System and classified them according to the Skeik Modified Scale to determine the effect of hyperbaric oxygen therapy (HBOT on the healing time of wounds. By way of comparison, the study was divided a second time, adjusting the initial population so as to include only cases that benefited from HBOT. Results: Overall improvement was achieved in 149 patients (67.7%, with a greater response in Wagner stages II and III. In patients who received 16–30 sessions, it was found that 77 (64.16% maintained their improvement and only 43 (28.85% had a relapse. Conclusions: At the end of the study, we found that HBOT is favourable and permanent in 52.72% of patients, seeing temporary improvement in 15%. This opens up the possibility of new developments that successfully determine suitable selective parameters and lead to a speedy recovery. Resumen: Antecedentes: La Organización Mundial de la Salud, indica que el número de personas con diabetes mellitus tipo 2 es superior a 366 millones y se espera que para el año 2030, aumente a 552 millones de la población global adulta, correspondiente al 8.3%. Cada año, el 14.9% de pacientes con esta enfermedad, presentan �

Chamber for Aerosol Deposition of Bioparticles

Science.gov (United States)

Kern, Roger; Kirschner, Larry

2008-01-01

Laboratory apparatus is depicted that is a chamber for aerosol deposition of bioparticles on surfaces of test coupons. It is designed for primary use in inoculating both flat and three-dimensional objects with approximately reproducible, uniform dispersions of bacterial spores of the genus Bacillus so that the objects could be used as standards for removal of the spores by quantitative surface sampling and/or cleaning processes. The apparatus is also designed for deposition of particles other than bacterial spores, including fungal spores, viruses, bacteriophages, and standard micron-sized beads. The novelty of the apparatus lies in the combination of a controllable nebulization system with a settling chamber large enough to contain a significant number of test coupons. Several companies market other nebulizer systems, but none are known to include chambers for deposition of bioparticles to mimic the natural fallout of bioparticles. The nebulization system is an expanded and improved version of commercially available aerosol generators that include nebulizers and drying columns. In comparison with a typical commercial aerosol generator, this system includes additional, higher-resolution flowmeters and an additional pressure regulator. Also, unlike a typical commercial aerosol generator, it includes stopcocks for separately controlling flows of gases to the nebulizer and drying column. To maximize the degree of uniformity of dispersion of bioaerosol, the chamber is shaped as an axisymmetrical cylinder and the aerosol generator is positioned centrally within the chamber and aimed upward like a fountain. In order to minimize electric charge associated with the aerosol particles, the drying column is made of aluminum, the drying column is in direct contact with an aluminum base plate, and three equally spaced Po-210 antistatic strips are located at the exit end of the drying column. The sides and top of the chamber are made of an acrylic polymer; to prevent

Construction of radon/radon daughter calibraton chamber

International Nuclear Information System (INIS)

Fry, J.; Gan, T.H.; Leach, V.A.; Saddlier, J.; Solomon, S.B.; Tam, K.K.; Travis, E.; Wykes, P.

1983-01-01

The radon/radon daughter test chamber is a copper lined room 1.65x1.75x2.75m with an effective volume of 8000 litres. The air residence time is controlled by circulating the air in the chamber through absolute filters which remove 99.9% of particulates. Radon is drawn into the chamber from a 17 μCi 226 RaCl source using the pressure differential across the blowers (<3 psi)

30 CFR 56.7807 - Flushing the combustion chamber.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber...

Scale testing of a partially confined blast chamber

CSIR Research Space (South Africa)

Grundling, W

2012-10-01

Full Text Available in pressure readings. A scale model of the blast chamber, Emily, was constructed with the addition of a pendulum plate hanging concentrically covering 65% of the open area. PURPOSE OF SCALED BLAST CHAMBER The purpose of this particular test is to evaluate... PHASE Illustrated in Figure 3 and 4 are the results obtained during testing of the scaled blast chamber. In both cases the pressure dissipates over time, showing pulsating behaviour as the shockwaves reflect off the chamber walls. By looking...

Recent developments in wire chamber tracking at SSC

International Nuclear Information System (INIS)

Ogren, H.

1990-01-01

All of the major SSC proposed detectors use wire chambers in their tracking systems. The feasibility of wire chambers in an SSC detector has now been established by a number of groups planning detectors at SSC. The major advances during the past year in understanding straw tube drift chambers are presented and several innovations in gaseous wire chambers are discussed. The R and D section will concentrate on progress in drift cell design, electronics and signal processing, and engineering aspects of the tracking designs

Method of controlling weld chamber purge and cover gas atmosphere

International Nuclear Information System (INIS)

Yeo, D.

1992-01-01

A method of controlling the gas atmosphere in a welding chamber includes detecting the absence of a fuel rod from the welding chamber and, in response thereto, initiating the supplying of a flow of argon gas to the chamber to purge air therefrom. Further, the method includes detecting the entry of a fuel rod in the welding chamber and, in response thereto, terminating the supplying of the flow of argon gas to the chamber and initiating the supplying of a flow of helium gas to the chamber to purge argon gas therefrom and displace the argon gas in the chamber. Also, the method includes detecting the withdrawal of the fuel rod from the welding chamber and, in response thereto, terminating the supplying of the flow of helium gas to the chamber and initiating the supplying of argon to the chamber to purge the air therefrom. The method also includes detecting the initiation of a weld cycle and, in response thereto, momentarily supplying a flow of argon gas to the welding electrode tip for initiating the welding arc. (Author)

Optical spark chamber

CERN Multimedia

CERN PhotoLab

1971-01-01

An optical spark chamber developed for use in the Omega spectrometer. On the left the supporting frame is exceptionally thin to allow low momentum particles to escape and be detected outside the magnetic field.

The Honeycomb Strip Chamber

International Nuclear Information System (INIS)

Graaf, Harry van der; Buskens, Joop; Rewiersma, Paul; Koenig, Adriaan; Wijnen, Thei

1991-06-01

The Honeycomb Strip Chamber (HSC) is a new position sensitive detector. It consists of a stack of folded foils, forming a rigid honeycomb structure. In the centre of each hexagonal cell a wire is strung. Conducting strips on the foils, perpendicular to the wires, pick up the induced avalanche charge. Test results of a prototype show that processing the signals form three adjacent strips nearest to the track gives a spatial resolution better than 64 μm for perpendicular incident tracks. The chamber performance is only slightly affected by a magnetic field. (author). 25 refs.; 21 figs

micro strip gas chamber

CERN Multimedia

1998-01-01

About 16 000 Micro Strip Gas Chambers like this one will be used in the CMS tracking detector. They will measure the tracks of charged particles to a hundredth of a millimetre precision in the region near the collision point where the density of particles is very high. Each chamber is filled with a gas mixture of argon and dimethyl ether. Charged particles passing through ionise the gas, knocking out electrons which are collected on the aluminium strips visible under the microscope. Such detectors are being used in radiography. They give higher resolution imaging and reduce the required dose of radiation.

Simulated Field Trials Using an Indoor Aerosol Test Chamber

National Research Council Canada - National Science Library

Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

2004-01-01

.... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

Simulated Field Trials Using An Indoor Aerosol Test Chamber

National Research Council Canada - National Science Library

Semler, D. D; Roth, A. P; Semler, K. A; Nolan, P. M

2004-01-01

.... In this method, the aerosol chamber control software manipulates circulation fan speeds, chamber vacuum and agent spray times to produce a simulated dynamic cloud within the aerosol test chamber...

Equipment for handling ionization chamber

International Nuclear Information System (INIS)

Altmann, J.

1988-01-01

The device consists of an ionization channel with an ionization chamber, of a support ring, axial and radial bearings, a sleeve, a screw gear and an electric motor. The ionization chamber is freely placed on the bottom of the ionization channel. The bottom part of the channel deviates from the vertical axis. The support ring propped against the axial bearing in the sleeve is firmly fixed to the top part of the ionization channel. The sleeve is fixed to the reactor lid. Its bottom part is provided with a recess for the radial bearing which is propped against a screw wheel firmly connected to the ionization channel. In measuring neutron flux, the screw wheel is rotated by the motor, thus rotating the whole ionization channel such that the ionization chamber is displaced into the reactor core.(J.B.). 1 fig

Weld Development for Aluminum Fission Chamber

Energy Technology Data Exchange (ETDEWEB)

Cross, Carl Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Jesse Norris [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-05-16

The Sigma welding team was approached to help fabricate a small fission chamber (roughly ½ inch dia. x ½ inch tall cylinder). These chambers are used as radiation sensors that contain small traces of radionuclides (Cf 252, U 235, and U 238) that serve to ionize gas atoms in addition to external radiation. When a voltage is applied within the chamber, the resulting ion flow can be calibrated and monitored. Aluminum has the advantage of not forming radioactive compounds when exposed to high external radiation (except from minor Na alloy content). Since aluminum has not been used before in this application, this presented an unexplored challenge.

BEBC Big European Bubble Chamber

CERN Multimedia

CERN PhotoLab

1974-01-01

A view of the dismantling of the magnet of BEBC, the 3.7 m European Bubble Chamber : iron magnetic shielding ; lower and upper parts of the vacuum enclosure of the magnet; turbo-molecular vacuum pumps for the "fish-eye" windows; the two superconducting coils; a handling platform; the two cryostats suspended from the bar of the travelling crane which has a 170 ton carrying capacity. The chamber proper, not dismantled, is inside the shielding.

Results from the MAC Vertex chamber

International Nuclear Information System (INIS)

Nelson, H.N.

1987-05-01

The design, construction, and performance characteristics of a high precision gaseous drift chamber made of thin walled proportional tubes are described. The device achieved an average spatial resolution of 45 μm in use for physics analysis with the MAC detector. The B-lifetime result obtained with this chamber is discussed

The Effects of Hyperbaric Oxygen Therapy on Experimental Colon Anastomosis After Preoperative Chemoradiotherapy

Science.gov (United States)

Yildiz, Ramazan; Can, Mehmet Fatih; Yagci, Gokhan; Ozgurtas, Taner; Guden, Metin; Gamsizkan, Mehmet; Ozturk, Erkan; Cetiner, Sadettin

2013-01-01

The aim of the present study was to investigate the effect of hyperbaric oxygen therapy (HBOT) on colon anastomosis after chemoradiotherapy (CRT). Sixty female Wistar-Albino rats were divided into 5 groups and underwent left colon resection and end-to-end anastomosis. CRT simulation was performed on 2 sham groups before the anastomosis, and 1 of these groups was administered additional postoperative HBOT. Two groups were administered CRT before the anastomosis, and 1 of them received additional postoperative HBOT. On postoperative day 5, all groups underwent relaparotomy; burst pressure was measured and samples were obtained for histopathologic and biochemical analysis. There was a significant weight loss in the CRT groups and postoperative HBOT had an improving effect. Significantly decreased burst pressure values increased up to the levels of the controls after HBOT. Hydroxyproline levels were elevated in all groups compared to the control group. Hydroxyproline levels decreased with HBOT after CRT. No significant difference was observed between the groups regarding fibrosis formation at the anastomosis site. However, regression was observed in fibrosis in the group receiving HBOT after CRT. Preoperative CRT affected anastomosis and wound healing unfavorably. These unfavorable effects were alleviated by postoperative HBOT. HBOT improved the mechanical and biochemical parameters of colon anastomosis in rats. PMID:23438274

Measurement and Compensation of BPM Chamber Motion in HLS

Science.gov (United States)

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G.

2010-06-01

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20μm without the compensation of BPM chamber motion in the runtime.

Measurement and Compensation of BPM Chamber Motion in HLS

International Nuclear Information System (INIS)

Li, J. W.; Sun, B. G.; Cao, Y.; Xu, H. L.; Lu, P.; Li, C.; Xuan, K.; Wang, J. G.

2010-01-01

Significant horizontal drifts in the beam orbit in the storage ring of HLS (Hefei Light Source) have been seen for many years. What leads to the motion of Beam Position Monitor (BPM) chamber is thermal expansion mainly caused by the synchrotron light. To monitor the BPM chamber motions for all BPMs, a BPM chamber motion measurement system is built in real-time. The raster gauges are used to measure the displacements. The results distinctly show the relation between the BPM chamber motion and the beam current. To suppress the effect of BPM chamber motion, a compensation strategy is implemented at HLS. The horizontal drifts of beam orbit have been really suppressed within 20μm without the compensation of BPM chamber motion in the runtime.

The thin-wall tube drift chamber operating in vacuum (prototype)

Science.gov (United States)

Alexeev, G. D.; Glonti, L. N.; Kekelidze, V. D.; Malyshev, V. L.; Piskun, A. A.; Potrbenikov, Yu. K.; Rodionov, V. K.; Samsonov, V. A.; Tokmenin, V. V.; Shkarovskiy, S. N.

2013-08-01

The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. "Self-centering" spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

The thin-wall tube drift chamber operating in vacuum (prototype)

International Nuclear Information System (INIS)

Alexeev, G.D.; Glonti, L.N.; Kekelidze, V.D.; Malyshev, V.L.; Piskun, A.A.; Potrbenikov, Yu.K.; Rodionov, V.K.; Samsonov, V.A.; Tokmenin, V.V.; Shkarovskiy, S.N.

2013-01-01

The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. “Self-centering” spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum

The thin-wall tube drift chamber operating in vacuum (prototype)

Energy Technology Data Exchange (ETDEWEB)

Alexeev, G.D. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Glonti, L.N., E-mail: glonti@sunse.jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kekelidze, V.D.; Malyshev, V.L.; Piskun, A.A.; Potrbenikov, Yu.K.; Rodionov, V.K.; Samsonov, V.A.; Tokmenin, V.V.; Shkarovskiy, S.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2013-08-01

The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. “Self-centering” spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

30 CFR 57.7807 - Flushing the combustion chamber.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 57.7807... and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been sitting unoperated in a drill hole shall be...

Study and analysis of drift chamber parameters

International Nuclear Information System (INIS)

Martinez Laso, L.

1988-01-01

The present work deals mainly with drift chambers. In the first chapter a summary of drift chamber properties is presented. The information has been collected from the extensive bibliography available in this field. A very simple calculation procedure of drift chamber parameters has been developed and is presented in detail in the second chapter. Some prototypes have been made following two geometries (multidrift chamber and Z-chambers). Several installations have been used for test and calibration of these prototypes. A complete description of these installations is given in the third chapter. Cosmic rays, beta particles from a Ru106 radiactive source and a test beam in the WA (West Area) of SPS at CERN have been used for experimental purposes. The analysis and the results are described for the different setups. The experimental measurements have been used to produce a complete cell parametrization (position as function of drift time) and to obtain spatial resolution values (in the range of 200-250 um). Experimental results are in good agreement with numerical calculations. (Author)

Tuned Chamber Core Panel Acoustic Test Results

Science.gov (United States)

Schiller, Noah H.; Allen, Albert R.

2016-01-01

This report documents acoustic testing of tuned chamber core panels, which can be used to supplement the low-frequency performance of conventional acoustic treatment. The tuned chamber core concept incorporates low-frequency noise control directly within the primary structure and is applicable to sandwich constructions with a directional core, including corrugated-, truss-, and fluted-core designs. These types of sandwich structures have long, hollow channels (or chambers) in the core. By adding small holes through one of the facesheets, the hollow chambers can be utilized as an array of low-frequency acoustic resonators. These resonators can then be used to attenuate low-frequency noise (below 400 Hz) inside a vehicle compartment without increasing the weight or size of the structure. The results of this test program demonstrate that the tuned chamber core concept is effective when used in isolation or combined with acoustic foam treatments. Specifically, an array of acoustic resonators integrated within the core of the panels was shown to improve both the low-frequency absorption and transmission loss of the structure in targeted one-third octave bands.

A plant chamber system with downstream reaction chamber to study the effects of pollution on biogenic emissions

NARCIS (Netherlands)

Timovsky, J.; Gankema, Paulien; Pierik, Ronald; Holzinger, Rupert

2014-01-01

A system of two plant chambers and a downstream reaction chamber has been set up to investigate the emission of biogenic volatile organic compounds (BVOCs) and possible effects of pollutants such as ozone. The system can be used to compare BVOC emissions from two sets of differently treated plants,

RF Anechoic Chambers, Tri-Service Research Laboratory

Data.gov (United States)

Federal Laboratory Consortium — In collaboration with the Navy, there are 12 RF Anechoic and static free exposure chambers located at TSRL. These chambers cover the majority of the RF spectrum and...

System of multiwire proportional chambers at the separated particle channel for the Mirabelle bubble chamber

International Nuclear Information System (INIS)

Bryukhanov, N.S.; Galyaev, N.A.; Kotov, V.I.; Prosin, B.V.; Romanov, Yu.A.; Khodyrev, Yu.S.

1980-01-01

A system of multiwire proportional chambers (MPC) operating on-line with a M-6000 computer used during tuning and monitoring of beam parameters in a separated particle channel for the Mirabelle bubble chamber is described. Peculiarities of the construction and main characteristics of two MPC versions are considered. The first version is intended for placing in a vacuum at the edges of high-frequency separator deflector, the second one - for placing outside a vacuum in ionoguide gaps. Power supply of the proportional chambers is carried out from local compact (160x95x50 mm) high-voltage sources remotely controlled from a channel panel by low voltage. A MPC position diagram in the accelerator channel, flowsheet of registering electronics for the MPC system, main circuits of high-voltage power source, analog-to-digital converter of a code and trunk amplifier are given. A graph of amplifier signal amplitude dependence on high voltage of a chamber for a different composition of a gaseous mixture is presented. It is noted that the used elements of the electronic system provide the reliable processing of data and its transmission for a great distance (approximately 400 m). It is underlined that the MPC system operation for a long time has shown its high efficiency and reliability

Monte Carlo modeling of ion chamber performance using MCNP.

Science.gov (United States)

Wallace, J D

2012-12-01

Ion Chambers have a generally flat energy response with some deviations at very low (2 MeV) energies. Some improvements in the low energy response can be achieved through use of high atomic number gases, such as argon and xenon, and higher chamber pressures. This work looks at the energy response of high pressure xenon-filled ion chambers using the MCNP Monte Carlo package to develop geometric models of a commercially available high pressure ion chamber (HPIC). The use of the F6 tally as an estimator of the energy deposited in a region of interest per unit mass, and the underlying assumptions associated with its use are described. The effect of gas composition, chamber gas pressure, chamber wall thickness, and chamber holder wall thicknesses on energy response are investigated and reported. The predicted energy response curve for the HPIC was found to be similar to that reported by other investigators. These investigations indicate that improvements to flatten the overall energy response of the HPIC down to 70 keV could be achieved through use of 3 mm-thick stainless steel walls for the ion chamber.

Construction of a full-length prototype of the BESIII drift chamber and on-detector test for the BESIII drift chamber electronics

International Nuclear Information System (INIS)

Qin Zhonghua; Wu Linghui; Liu Jianbei; Chinese Academy of Sciences, Beijing; Yan Zhikang; Hunan Univ., Changsha; Chen Yuanbo; Chen Chang; Xu Meihang; Wang Lan; Ma Xiaoyan; Jin Yan; Liu Rongguang; Tang Xiao; Zhang Guifang; Zhu Qiming; Sheng Huayi; Zhu Kejun

2007-01-01

A full-length prototype of the BESIII drift chamber was built. The experience gained on gas sealing, high voltage supply and front-end electronics installation should be greatly beneficial to the successful construction of the BESIII drift chamber. An on-detector test of the BESIII drift chamber electronics was carried out with the constructed prototype chamber. The noise performance, drift time and charge measurements, and electronics gains were examined specifically. The final test results indicate that the electronics have a good performance and can satisfy their design requirements. (authors)

Final report for NIF chamber dynamics studies

International Nuclear Information System (INIS)

Burnham, A; Peterson, P F; Scott, J M

1998-01-01

The National Ignition Facility (NIF), a 1.8 MJ, 192 laser beam facility, will have anticipated fusion yields of up to 20 MJ from D-T pellets encased in a gold hohlraum target. The energy emitted from the target in the form of x rays, neutrons, target debris kinetic energy, and target shrapnel will be contained in a 5 m. radius spherical target chamber. various diagnostics will be stationed around the target at varying distances from the target. During each shot, the target will emit x rays that will vaporize nearby target facing surfaces including those of the diagnostics, the target positioner, and other chamber structures. This ablated vapor will be transported throughout the chamber, and will eventually condense and deposit on surfaces in the chamber, including the final optics debris shields. The research at the University of California at Berkeley relates primarily to the NIF chamber dynamics. The key design issues are the ablation of the chamber structures, transport of the vapor through the chamber and the condensation or deposition processes of those vaporized materials. An understanding of these processes is essential in developing a concept for protecting the fina optics debris shields from an excessive coating (> 10 A) of target debris and ablated material, thereby prolonging their lifetime between change-outs. At Berkeley, we have studied the physical issues of the ablation process and the effects of varying materials, the condensation process of the vaporized material, and design schemes that can lower the threat posed to the debris shields by these processes. The work or portions of the work completed this year have been published in several papers and a dissertation [l-5

MIMO OTA Testing in Small Multi-Probe Anechoic Chamber Setups

DEFF Research Database (Denmark)

Llorente, Ines Carton; Fan, Wei; Pedersen, Gert F.

2016-01-01

OTA testing of MIMO capable terminals is often performed in large anechoic chambers, where planar waves impinging the test area are assumed. Furthermore, reflections from the chamber, and probe coupling are often considered negligible due to the large dimensions of the chamber. This paper...... investigates the feasibility of reducing the physical dimension of 2D multi-probe anechoic chamber setups for MIMO OTA testing, with the purpose of reducing the cost and space of the setup. In the paper, a channel emulation algorithm and chamber compensation technique are proposed for MIMO OTA testing in small...... anechoic chambers. The performance deterioration in a small anechoic chamber, i.e., with a ring radius of 0.5 m, is demonstrated via simulations....

Proportional chambers and multiwire drift chambers at high rates

International Nuclear Information System (INIS)

Walenta, A.H.

1977-01-01

The high event and particle rates expected for ISABELLE intersecting storage rings raise the question whether PWC's and drift chambers, now widely in use in experiments, still can operate under such conditions. Various effects depend on the number of avalanches produced per length of wire N and the size of the avalanche Q, i.e., on the number of positive ions created in an avalanche. Therefore the important parameter for the following discussion is the product QN. The minimum Q is determined by the type and noise level of preamplifiers used. Examples are given for a typical low noise amplifier as well as for a typical integrated ''cheap'' amplifier. The rate/wire length N depends on the chamber arrangement, wire spacing, etc. In multiwire drift chambers, a single wire shows space-charge effects reducing the pulse height by 1% at a rate of N = 7 x 10 3 mm -1 sec -1 . At a rate of N approximately equal to 10 5 mm -1 sec -1 an efficiency loss of the order of 1% was noticed. The aging effect due to deposits on the anode wire can be reduced using low noise amplifiers and low gas gain to such an extent that a lifetime of about half a year at ISABELLE can be expected. The use of conventional cheap preamplifiers will result in a typical lifetime of about 30 days. Improvements are probable. The time resolution of Δt/sub r/ = 4 nsec fwhm seems adequate for event rates of 10 7 sec -1 . The memory time Δt/sub m/ greater than or equal to 100 nsec may cause serious problems for pattern recognition depending on layout and readout. The use of induced signals on cathode pads, thus reading out shorter parts of the wire, can solve the problem

Track photographing in 8-m streamer chamber

International Nuclear Information System (INIS)

Anisimova, N.Z.; Davidenko, V.A.; Kantserov, V.A.; Rybakov, V.G.; Somov, S.V.

1981-01-01

A system for obtaining data from a streamer chamber intended for measuring muon polarization is described. An optical scheme for photographing of tracks in the chamber is given. The photographing process is complicated at the expense of large dimensions and module structure of the chamber as well as due to insufficient for direct photographing brightness of streamers. The system described was tested during a long time in a physical experiment. More than 100 thousand photos have been taken by its means [ru

Calibration of working standard ionization chambers and dose standardization

International Nuclear Information System (INIS)

Abd Elmahoud, A. A. B.

2011-01-01

Measurements were performed for the calibration of two working standard ionization chambers in the secondary standard dosimetry laboratory of Sudan. 600 cc cylindrical former type and 1800 cc cylindrical radical radiation protection level ionization chambers were calibrated against 1000 cc spherical reference standard ionization chamber. The chamber were calibrated at X-ray narrow spectrum series with beam energies ranged from (33-116 KeV) in addition to 1''3''7''Cs beam with 662 KeV energy. The chambers 0.6 cc and 0.3 cc therapy level ionization were used for dose standardization and beam output calibrations of cobalt-60 radiotherapy machine located at the National Cancer Institute, University of Gazira. Concerning beam output measurements for 6''0''Co radiotherapy machine, dosimetric measurements were performed in accordance with the relevant per IAEA dosimetry protocols TRS-277 and TRS-398. The kinetic energy released per unit mass in air (air kerma) were obtained by multiplying the corrected electrometer reading (nC/min) by the calibration factors (Gy/n C) of the chambers from given in the calibration certificate. The uncertainty of measurements of air kerma were calculated for the all ionization chambers (combined uncertainty) the calibration factors of these ionization chambers then were calculated by comparing the reading of air kerma of secondary standard ionization chambers to than from radical and farmer chambers. The result of calibration working standard ionization chambers showed different calibration factors ranged from 0.99 to 1.52 for different radiation energies and these differences were due to chambers response and specification. The absorbed dose to to water calculated for therapy ionization chamber using two code of practice TRS-277 and TRS-398 as beam output for 6''0''Co radiotherapy machine and it can be used as a reference for future beam output calibration in radiotherapy dosimetry. The measurement of absorbed dose to water showed that the

Measuring the sensitivity of a boron-lined ion chamber

International Nuclear Information System (INIS)

Barton, D.M.

1992-03-01

Boron-lined ion chambers are used to monitor external neutron flux from fissionable materials assembled at the Los Alamos Critical Assembly Experiment Facility. The sensitivity of these chambers must be measured periodically in order to detect changes in filling gas and to evaluate other factors that may affect chamber performance. We delineate a procedure to measure ion chamber response using a particular neutron source ( 239 PuBe) in a particular moderating geometry of polyethylene. We also discuss use of the amplifier, high-voltage power supply, recorders, and scram circuits that comprise the complete ion chamber monitoring system

GBO RF Anechoic Chamber & Antenna Test Range

Data.gov (United States)

Federal Laboratory Consortium — A shielded anechoic chamber measuring 15 by 15 by 37 feet is located in the Jansky Laboratory at Green Bank. This chamber has been outfitted as a far-field antenna...

Safety shield for vacuum/pressure-chamber windows

Science.gov (United States)

Shimansky, R. A.; Spencer, R.

1980-01-01

Optically-clear shatter-resistant safety shield protects workers from implosion and explosion of vacuum and pressure windows. Plastic shield is inexpensive and may be added to vacuum chambers, pressure chambers, and gas-filling systems.

Inhibition of hypoxia-associated response and kynurenine production in response to hyperbaric oxygen as mechanisms involved in protection against experimental cerebral malaria.

Science.gov (United States)

Bastos, Marcele F; Kayano, Ana Carolina A V; Silva-Filho, João Luiz; Dos-Santos, João Conrado K; Judice, Carla; Blanco, Yara C; Shryock, Nathaniel; Sercundes, Michelle K; Ortolan, Luana S; Francelin, Carolina; Leite, Juliana A; Oliveira, Rafaella; Elias, Rosa M; Câmara, Niels O S; Lopes, Stefanie C P; Albrecht, Letusa; Farias, Alessandro S; Vicente, Cristina P; Werneck, Claudio C; Giorgio, Selma; Verinaud, Liana; Epiphanio, Sabrina; Marinho, Claudio R F; Lalwani, Pritesh; Amino, Rogerio; Aliberti, Julio; Costa, Fabio T M

2018-03-20

Cerebral malaria (CM) is a multifactorial syndrome involving an exacerbated proinflammatory status, endothelial cell activation, coagulopathy, hypoxia, and accumulation of leukocytes and parasites in the brain microvasculature. Despite significant improvements in malaria control, 15% of mortality is still observed in CM cases, and 25% of survivors develop neurologic sequelae for life-even after appropriate antimalarial therapy. A treatment that ameliorates CM clinical signs, resulting in complete healing, is urgently needed. Previously, we showed a hyperbaric oxygen (HBO)-protective effect against experimental CM. Here, we provide molecular evidence that HBO targets brain endothelial cells by decreasing their activation and inhibits parasite and leukocyte accumulation, thus improving cerebral microcirculatory blood flow. HBO treatment increased the expression of aryl hydrocarbon receptor over hypoxia-inducible factor 1-α (HIF-1α), an oxygen-sensitive cytosolic receptor, along with decreased indoleamine 2,3-dioxygenase 1 expression and kynurenine levels. Moreover, ablation of HIF-1α expression in endothelial cells in mice conferred protection against CM and improved survival. We propose that HBO should be pursued as an adjunctive therapy in CM patients to prolong survival and diminish deleterious proinflammatory reaction. Furthermore, our data support the use of HBO in therapeutic strategies to improve outcomes of non-CM disorders affecting the brain.-Bastos, M. F., Kayano, A. C. A. V., Silva-Filho, J. L., Dos-Santos, J. C. K., Judice, C., Blanco, Y. C., Shryock, N., Sercundes, M. K., Ortolan, L. S., Francelin, C., Leite, J. A., Oliveira, R., Elias, R. M., Câmara, N. O. S., Lopes, S. C. P., Albrecht, L., Farias, A. S., Vicente, C. P., Werneck, C. C., Giorgio, S., Verinaud, L., Epiphanio, S., Marinho, C. R. F., Lalwani, P., Amino, R., Aliberti, J., Costa, F. T. M. Inhibition of hypoxia-associated response and kynurenine production in response to hyperbaric oxygen

Developing Cloud Chambers with High School Students

Science.gov (United States)

Ishizuka, Ryo; Tan, Nobuaki; Sato, Shoma; Zeze, Syoji

The result and outcome of the cloud chamber project, which aims to develop a cloud chamber useful for science education is reported in detail. A project includes both three high school students and a teacher as a part of Super Science High School (SSH) program in our school. We develop a dry-ice-free cloud chamber using salt and ice (or snow). Technical details of the chamber are described. We also argue how the project have affected student's cognition, motivation, academic skills and behavior. The research project has taken steps of professional researchers, i.e., in planning research, applying fund, writing a paper and giving a talk in conferences. From interviews with students, we have learnt that such style of scientific activity is very effective in promoting student's motivation for learning science.

The Impedance of Multi-layer Vacuum Chambers

CERN Document Server

Vos, L

2003-01-01

Many components of the LHC vacuum chamber have multi-layered walls : the copper coated cold beam screen, the titanium coated ceramic chamber of the dump kickers, the ceramic chamber of the injection kickers coated with copper stripes, only to name a few. Theories and computer programs are available for some time already to evaluate the impedance of these elements. Nevertheless, the algorithm developed in this paper is more convenient in its application and has been used extensively in the design phase of multi-layer LHC vacuum chamber elements. It is based on classical transmission line theory. Closed expressions are derived for simple layer configurations, while beam pipes involving many layers demand a chain calculation. The algorithm has been tested with a number of published examples and was verified with experimental data as well.

Laboratory implantation for well type ionization chambers calibration

International Nuclear Information System (INIS)

Vianello, E.A.; Dias, D.J.; Almeida, C.E. de

1998-01-01

The Radiological Science Laboratory is implanting a service for calibration of well type chambers by IAEA training program. The kerma rate in the air (mu Gy/h) of the linear Cs-137 reference source CDCS-J4 have been determined using a well type chamber Standard Imaging HDR-1000 model, which have been calibrated at Secondary Standard Laboratory Calibration of IAEA, whereas two HDR-1000 Plus chambers were calibrated too, following the same standards. The results were compared with Wisconsin University calibration certification and has demonstrated that well type ionization chamber calibration can be used in brachytherapy for several kinds of radionuclides. (Author)

Shock tubes: compressions in the low pressure chamber

International Nuclear Information System (INIS)

Schins, H.; Giuliani, S.

1986-01-01

The gas shock tube used in these experiments consists of a low pressure chamber and a high pressure chamber, divided by a metal-diaphragm-to-rupture. In contrast to the shock mode of operation, where incident and reflected shocks in the low pressure chamber are studied which occur within 3.5 ms, in this work the compression mode of operation was studied, whose maxima occur (in the low pressure chamber) about 9 ms after rupture. Theoretical analysis was done with the finite element computer code EURDYN-1M, where the computation was carried out to 30 ms

Simple structure diffusion cloud chamber for educational purpose

International Nuclear Information System (INIS)

Hrehuss, Gy.; Molnar, B.

1982-01-01

A simple structure diffusion cloud chamber was designed and built with educational aim. The source of alpha particles is Am-241 radioisotope smeared on steel foil, the source of vapor is a felt disc saturated with methanol. Five minutes after covering the chamber the system achieves the thermodynamic equilibrium and alpha particle tracks of 5 cm length become visible in the centre of the chamber. Life-time of a track is about 0.5-1 second, the frequency is 2-3 tracks/s. The presented diffusion chamber can be built simply and easily, using cheap common materials and components. (D.Gy.)

Successful hyperbaric oxygen therapy for laryngeal radionecrosis after chemoradiotherapy for mesopharyngeal cancer. Case report and literature review

International Nuclear Information System (INIS)

Abe, Madoka; Terashima, Kotaro; Matsuo, Mioko; Uehara, Satoru; Shioyama, Yoshiyuki; Hara, Iwao

2012-01-01

Laryngeal radionecrosis is one of the most troublesome late complications of radiotherapy, because it is frequently resistant to treatment and laryngectomy is required in the worst case. Here, we report a case of laryngeal radionecrosis, successfully treated by use of hyperbaric oxygen (HBO) therapy, in which laryngectomy was avoided. A 67-year-old male received radical chemoradiotherapy (CRT) for mesopharyngeal cancer, which included radiotherapy with a total dose of 71.4 Gy/38 Fr and chemotherapy with CDDP + S-1. He developed dyspnea and throat pain 9 months after completion of CRT. Laryngoscopy revealed vocal cord impairment because of severe laryngeal edema. He was diagnosed as having laryngeal radionecrosis and initially received conservative therapy combined with antibiotics, steroids, and prostaglandins. Because his dyspnea was persistent despite this treatment, HBO therapy was administered 20 times, and resulted in complete remission of the dyspnea. HBO therapy, therefore, is regarded as an effective conservative therapeutic option for laryngeal radionecrosis. (author)

Prevention of avascular necrosis in displaced talar neck fractures by hyperbaric oxygenation therapy: A dual case report

Directory of Open Access Journals (Sweden)

Mei-Dan O

2008-01-01

Full Text Available Talar neck fractures are a rare injury that account for less then 2% of all foot fractures. Displaced fractures are associated with an exceedingly high rate of avascular necrosis (AVN. The incidence of AVN following Hawkins Type 3 fractures of the talar neck may approach 100%, particularly if diagnosis and reduction are delayed. Severe cases may present as pain and disability of the ankle and the subtalar joints due to a talar dome collapse, resulting in degenerative changes that usually require hind foot arthrodesis. We present two cases of traumatic displaced talar neck fractures which were treated surgically more than 2 weeks following injury due to a delay in diagnosis. Both patients underwent hyperbaric oxygen therapy (HBOT after the operation and neither resulted in AVN of the talus in a three-year follow-up. We suggest that this favorable result may be due to the beneficial effects of HBOT.

Effects of air humidity on ionization chamber response

International Nuclear Information System (INIS)

Meger, C.; DeLuca, P.M. Jr.; Pearson, D.W.; Venci, R.

1983-01-01

A study of the effect of air humidity on four different ionization chamber cap materials verified earlier studies (Kristensen and Sundbom, 1981; Mijnheer et al., 1983) and extended our understanding of the problem. We found nylon and A-150 plastic caps swell as they absorb water from the air. This accounts for as much as 2.5% increase in ionization response. Graphite chambers readily absorb and desorb water from the air. This creates a problem in maintaining dry air in a wet graphite chamber. Humid air has a different density and W value than dry air (Niatel, 1969, 1975). This decreases the charge collected in a wet graphite chamber. We observe a decrease in response of approximately 2%, a value greater than can be accounted for by these effects alone. Polyethylene chambers are unaffected by humid air. 4 refs., 9 figs

Charpak hemispherical wire chamber

CERN Multimedia

1970-01-01

pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

Preliminary study of a new intraocular method in the diagnosis and treatment of Propionibacterium acnes endophthalmitis following cataract extraction.

Science.gov (United States)

Owens, S L; Lam, S; Tessler, H H; Deutsch, T A

1993-04-01

Late endophthalmitis, due to Propionibacterium acnes, developed in three patients following uncomplicated extracapsular cataract extraction and posterior chamber intraocular lens (PC-IOL) insertion. Cultures from the capsular bag yielded P. acnes in all three. With topical anesthesia and through an anterior chamber paracentesis, culture specimens were taken from and clindamycin irrigated into the capsular bag. Filtered 100% oxygen was introduced into the anterior chamber in two; the third also received an injection of gentamicin and dexamethasone into the capsular bag. After treatment, two patients received oral antibiotics; one received hyperbaric oxygen therapy. Visual acuity was improved and inflammation reduced in all three. However, after treatment, ocular toxic effects due to clindamycin were suspected in one. This approach offers several clear advantages, including topical anesthesia, outpatient management, elimination of the need for vitrectomy, and retention of the intraocular lens (IOL).

Cloud chamber photographs of the cosmic radiation

CERN Document Server

Rochester, George Dixon

1952-01-01

Cloud Chamber Photographs of the Cosmic Radiation focuses on cloud chamber and photographic emulsion wherein the tracks of individual subatomic particles of high energy are studied. The publication first offers information on the technical features of operation and electrons and cascade showers. Discussions focus on the relationship in time and space of counter-controlled tracks; techniques of internal control of the cloud chamber; cascade processes with artificially-produced electrons and photons; and nuclear interaction associated with an extensive shower. The manuscript then elaborates on

"Flat-Fish" vacuum chamber for the ISR

CERN Multimedia

CERN PhotoLab

1983-01-01

The "Flat-Fish" vacuum chamber was a very special one for the ISR beam intersection I-4, inside the Split-Field Magnet. Technical descriptions are given with pictures 7802042 and 7712182. There were several generations of this chamber. This picture was taken during the last year of ISR operation. See also 7510230X, 7511123X, 7802039, 7802041. A flat-fish type vacuum chamber was also used at I-8, inside the Open Axial Field Magnet (OAFM, experiment 807 on large transverse momentum collision products), see 7901358.

Growing and Analyzing Biofilms in Flow Chambers

DEFF Research Database (Denmark)

Tolker-Nielsen, Tim; Sternberg, Claus

2011-01-01

This unit describes the setup of flow chamber systems for the study of microbial biofilms, and methods for the analysis of structural biofilm formation. Use of flow chambers allows direct microscopic investigation of biofilm formation. The biofilms in flow chambers develop under hydrodynamic......, and disassembly and cleaning of the system. In addition, embedding and fluorescent in situ hybridization of flow chamber–grown biofilms are addressed. Curr. Protoc. Microbiol. 21:1B.2.1-1B.2.17. © 2011 by John Wiley & Sons, Inc....

Hyperbaric Oxygen Therapy for the Treatment of Diabetic Foot Ulcers: A Health Technology Assessment

Science.gov (United States)

Lambrinos, Anna; Chan, Brian; Wells, David; Holubowich, Corinne

2017-01-01

Background About 15% to 25% of people with diabetes will develop a foot ulcer. These wounds are often resistant to healing; therefore, people with diabetes experience lower limb amputation at about 20 times the rate of people without diabetes. If an ulcer does not heal with standard wound care, other therapeutic interventions are offered, one of which is hyperbaric oxygen therapy (HBOT). However, the effectiveness of this therapy is not clearly known. The objectives of this health technology assessment were to assess the safety, clinical effectiveness, and cost-effectiveness of standard wound care plus HBOT versus standard wound care alone for the treatment of diabetic foot ulcers. We also investigated the preferences and perspectives of people with diabetic foot ulcers through lived experience. Methods We performed a review of the clinical and economic literature for the effectiveness and cost-effectiveness of hyperbaric oxygen therapy, as well as the budget impact of HBOT from the perspective of the Ministry of Health and Long-Term Care. We assessed the quality of the body of clinical evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. To better understand the preferences, perspectives, and values of patients with diabetic foot ulcers and their experience with HBOT, we conducted interviews and administered an online survey. Results Seven randomized controlled trials and one nonrandomized controlled trial met the inclusion criteria. Comparing standard wound care plus HBOT with standard wound care alone, we found mixed results for major amputation rates (GRADE quality of evidence: low), a significant difference in favour of standard wound care plus HBOT on ulcers healed (GRADE quality of evidence: low), and no difference in terms of adverse events (GRADE quality of evidence: moderate). There is a large degree of uncertainty associated with the evaluation of the cost-effectiveness of standard wound

Ballistic-neutralized chamber transport of intense heavy ion beams

International Nuclear Information System (INIS)

Rose, D.V.; Welch, D.R.; Oliver, B.V.; Clark, R.E.; Sharp, W.M.; Friedman, A.

2001-01-01

Two-dimensional particle-in-cell simulations of intense heavy ion beams propagating in an inertial confinement fusion (ICF) reactor chamber are presented. The ballistic-neutralized transport scheme studied uses 4 GeV Pb +1 ion beams injected into a low-density, gas-filled reactor chamber and the beam is ballistically focused onto an ICF target before entering the chamber. Charge and current neutralization of the beam is provided by the low-density background gas. The ballistic-neutralized simulations include stripping of the beam ions as the beam traverses the chamber as well as ionization of the background plasma. In addition, a series of simulations are presented that explore the charge and current neutralization of the ion beam in an evacuated chamber. For this vacuum transport mode, neutralizing electrons are only drawn from sources near the chamber entrance

A Customizable Chamber for Measuring Cell Migration.

Science.gov (United States)

Chowdhury, Aniqa N; Vo, Huu Tri; Olang, Sharon; Mappus, Elliott; Peterson, Brian; Hlavac, Nora; Harvey, Tyler; Dean, Delphine

2017-03-12

Cell migration is a vital part of immune responses, growth, and wound healing. Cell migration is a complex process that involves interactions between cells, the extracellular matrix, and soluble and non-soluble chemical factors (e.g., chemoattractants). Standard methods for measuring the migration of cells, such as the Boyden chamber assay, work by counting cells on either side of a divider. These techniques are easy to use; however, they offer little geometric modification for different applications. In contrast, microfluidic devices can be used to observe cell migration with customizable concentration gradients of soluble factors 1 , 2 . However, methods for making microfluidics based assays can be difficult to learn. Here, we describe an easy method for creating cell culture chambers to measure cell migration in response to chemical concentration gradients. Our cell migration chamber method can create different linear concentration gradients in order to study cell migration for a variety of applications. This method is relatively easy to use and is typically performed by undergraduate students. The microchannel chamber was created by placing an acrylic insert in the shape of the final microchannel chamber well into a Petri dish. After this, poly(dimethylsiloxane) (PDMS) was poured on top of the insert. The PDMS was allowed to harden and then the insert was removed. This allowed for the creation of wells in any desired shape or size. Cells may be subsequently added to the microchannel chamber, and soluble agents can be added to one of the wells by soaking an agarose block in the desired agent. The agarose block is added to one of the wells, and time-lapse images can be taken of the microchannel chamber in order to quantify cell migration. Variations to this method can be made for a given application, making this method highly customizable.

Test chamber for alpha spectrometry

Science.gov (United States)

Larsen, Robert P.

1977-01-01

Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

Upgrades of the ATLAS Muon Spectrometer with sMDT Chambers

CERN Document Server

Ferretti, Claudio; The ATLAS collaboration

2015-01-01

With half the drift-tube diameter of the Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer and otherwise unchanged operating parameters, small-diameter Muon Drift Tube (sMDT) chambers provide an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit. The chamber assembly time has been reduced by a factor of seven to one working day and the sense wire positioning accuracy improved by a factor of two to better than ten microns. Two sMDT chambers have been installed in ATLAS in 2014 to improve the momentum resolution in the barrel part of the spectrometer. The construction of additional twelve chambers covering the feet regions of the ATLAS detector has started. It will be followed by the replacement of the MDT chambers at the ends of the barrel inner layer by sMDTs improving the Performance at the high expected background rates and providing space for additional RPC trigger chambers.

Upgrades of the ATLAS Muon Spectrometer with sMDT Chambers

CERN Document Server

Ferretti, C

2016-01-01

With half the drift-tube diameter of the Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer and otherwise unchanged operating parameters, small-diameter Muon Drift Tube (sMDT) chambers provide an order of magnitude higher rate capability and can be installed in detector regions where MDT chambers do not fit. The chamber assembly time has been reduced by a factor of seven to one working day and the sense wire positioning accuracy improved by a factor of two to better than ten microns. Two sMDT chambers have been installed in ATLAS in 2014 to improve the momentum resolution in the barrel part of the spectrometer. The construction of an additional twelve chambers covering the feet regions of the ATLAS detector has started. It will be followed by the replacement of the MDT chambers at the ends of the barrel inner layer by sMDTs improving the Performance at the high expected background rates and providing space for additional RPC trigger chambers.

Upgrades Of The ATLAS Muon Spectrometer With sMDT Chambers

CERN Document Server

Ferretti, Claudio; The ATLAS collaboration

2015-01-01

The Monitored Drift Tube (MDT) chambers of the ATLAS muon spectrometer demonstrated that they provide very precise and robust tracking over large areas. Goals of ATLAS muon detector upgrades are to increase the acceptance for precision muon momentum measurement and triggering and to improve the rate capability of the muon chambers in the high-background regions when the LHC luminosity increases. Small-diameter Muon Drift Tube (sMDT) chambers have been developed for these purposes. With half the drift-tube diameter of the MDT chambers and otherwise unchanged operating parameters, sMDT chambers share the advantages with the MDTs, but have more than ten times higher rate capability and can be installed in detector regions where MDT chambers do not fit in. The chamber assembly methods have been optimized for mass production, reducing cost and construction time considerably and improving the sense wire positioning accuracy to better than ten microns. Two sMDT chambers have been installed in 2014 to improve the mom...

Utilizing Chamber Data for Developing and Validating Climate Change Models

Science.gov (United States)

Monje, Oscar

2012-01-01

Controlled environment chambers (e.g. growth chambers, SPAR chambers, or open-top chambers) are useful for measuring plant ecosystem responses to climatic variables and CO2 that affect plant water relations. However, data from chambers was found to overestimate responses of C fluxes to CO2 enrichment. Chamber data may be confounded by numerous artifacts (e.g. sidelighting, edge effects, increased temperature and VPD, etc) and this limits what can be measured accurately. Chambers can be used to measure canopy level energy balance under controlled conditions and plant transpiration responses to CO2 concentration can be elucidated. However, these measurements cannot be used directly in model development or validation. The response of stomatal conductance to CO2 will be the same as in the field, but the measured response must be recalculated in such a manner to account for differences in aerodynamic conductance, temperature and VPD between the chamber and the field.

Irradiation chamber for photoactivation patient treatment system

International Nuclear Information System (INIS)

Lee, K.H.; Troutner, V.H.; Goss, J.; King, M.J.

1988-01-01

A flat plate irradiation chamber is described for use in a patient treatment system for altering cells, including treating the cells with a photoactivatable agent and passing the cells and the agent through a field of photoactivating radiation whereby the agent is caused to be activated and to affect the cells. The agent and the cells are contained in the irradiation chamber during irradiation. The flat plate irradiation chamber comprises: a rigid top sheet matably joined with a rigid bottom sheet, forming therebetween a rigid serpentine pathway for conducting the cells through the field of radiation; and pump block means for holding tubing means in fluid communication with the serpentine pathway and adapted for engaging a peristaltic pump whereby rotation of the pump causes the cells to flow through the serpentine pathway, and wherein the chamber is removable from the system and disposable

HYLIFE-II reactor chamber mechanical design: Update

International Nuclear Information System (INIS)

House, P.A.

1992-01-01

Mechanical design features of the reactor chamber for the HYLIFE-II inertial confinement fusion power plant are presented. A combination of oscillating and steady, molten salt streams (Li 2 BeF 4 ) are used for shielding and blast protection of the chamber walls. The system is designed for a 6 Hz repetition rate. Beam path clearing, between shots, is accomplished with the oscillating flow. The mechanism for generating the oscillating streams is described. A design configuration of the vessel wall allows adequate cooling and provides extra shielding to reduce thermal stresses to tolerable levels. The bottom portion of the reactor chamber is designed to minimize splash back of the high velocity (17 m/s) salt streams and also recover up to half of the dynamic head. Cost estimates for a 1 GW e and 2 GW e reactor chamber are presented

Ultrasonic cleaning of electrodes of wire chambers

International Nuclear Information System (INIS)

Krasnov, V.A.; Kurepin, A.B.; Razin, V.I.

1980-01-01

A technological process of cleaning electrodes and working volume surfaces of wire chambers from contaminations by the simultaneous mechanical action of the energy of ultrasonic oscillations and the chemical action of detergents is discussed. A device for cleaning wire electrodes of proportional chambers of 0.3x0.4 m is described. The device uses two ultrasonic generators with a total power of 0.5 kW. As a detergent use is made of a mixture of ethyl alcohol, gasoline and freon. In the process of cleaning production defects can be detected in the wire chambers which makes it possible to timely remove the defects. Measurements of the surface resistance of fiberglass laminate of printed drift chamber electrodes at a voltage of 2 kV showed that after completing the cleaning process the resistance increases 15-20%