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Sample records for extreme decompression rates

  1. Probability of hypobaric decompression sickness including extreme exposures.

    PubMed

    Conkin, Johnny; Gernhardt, Michael L; Abercromby, Andrew F; Feiveson, Alan H

    2013-07-01

    The fitting of probabilistic decompression sickness (DCS) models is more effective when data encompass a wide range of DCS incidence. We obtained such data from the Air Force Research Laboratory Altitude Decompression Sickness Research Database. The data are results from 29 tests comprising 708 human altitude chamber exposures (536 men and 172 women). There were 340 DCS outcomes with per-test DCS incidence ranging from 0 to 88%. The tests were characterized by direct ascent at a rate of 5000 ft x min(-1) (1524 m x min(-1)) to a range of altitudes (226 to 378 mmHg) for 4 h after prebreathe times of varying length and with varying degrees of physical activity while at altitude. Logistic regression was used to develop an expression for the probability of DCS [P(DCS)] using the Hill equation with decompression dose as the main predictor. Here, decompression dose is defined in terms of either the tissue ratio (TR) or a bubble growth index (BGI). Other predictors in the model were gender and peak exercise intensity at altitude. All three predictors (decompression dose, gender, and exercise intensity) were important contributions to the model for P(DCS). Higher TR or BGI, male gender, and higher exercise intensity at altitude all increased the modeled decompression dose. Using either TR or BGI to define decompression dose provided comparable results, suggesting that a simple TR is adequate for simple altitude exposures as an abstraction of the true decompression dose. The model is primarily heuristic and limits estimates of P(DCS) to only a 4-h exposure.

  2. How much does decompressive laparotomy reduce the mortality rate in primary abdominal compartment syndrome?

    PubMed Central

    Muresan, Mircea; Muresan, Simona; Brinzaniuc, Klara; Voidazan, Septimiu; Sala, Daniela; Jimborean, Ovidiu; Hussam, Al Husseim; Bara, Tivadar; Popescu, Gabriel; Borz, Cristian; Neagoe, Radu

    2017-01-01

    Abstract Contribution of decompressive laparotomy within the framework of the complex therapeutic algorithm of abdominal compartment syndrome (ACS) is cited with an extremely heterogeneous percentage in terms of survival. The purpose of this study was to present new data regarding contribution of each therapeutic step toward decreasing the mortality of this syndrome. This is a longitudinal prospective study including 134 patients with risk factors for ACS. The intra-abdominal pressure was measured every hour indirectly based on transvesical approach and the appearance of organ dysfunction. Specific therapy for ACS was based on the 2013 World Society of Abdominal Compartment Syndrome guidelines, which include laparotomy decompression. Management of the temporarily open abdomen included an assisted vacuum wound therapy. Of 134 patients, 66 developed ACS. The average intra-abdominal pressure significantly decreased after therapy and decompression surgery. The overall rate of mortality was 27.3% with statistical significance in necrotizing infected pancreatitis. Surgical decompression performed within the first 24 hours after the onset of ACS had a protective role against mortality (odds ratio <1). The average time after which laparotomy decompression was performed was 16.23 hours. The complications occurred during TAC were 2 wound suppurations and 1 intestinal obstruction. Wound suppurations evolved favorably by using vacuum wound-assisted therapy associated with the general treatment, whereas for occlusion, resurgery was performed after which adhesions dissolved. The final closure of the abdomen was performed at a mean of 11.7 days (min. = 9, max. = 14). The closure type was primary suture of the musculoaponeurotic edges in 4 cases, and the use of dual mesh in the other 11 cases. The highest mortality rate in the study group was registered in patients with necrotizing pancreatitis and the lowest in trauma group. Surgical decompression within the framework

  3. Intraoperative Nerve Monitoring During Nerve Decompression Surgery in the Lower Extremity.

    PubMed

    Anderson, James C; Yamasaki, Dwayne S

    2016-04-01

    This article describes the benefits of intraoperative neurophysiologic monitoring (IONM) and proposes methods for integration into nerve decompression procedures. Standard procedures for intraoperative nerve monitoring (IONM) are illustrated as they would apply to the 3 nerve tunnels that have significant motor components within the lower extremity. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Readmission rates after decompression surgery in patients with lumbar spinal stenosis among Medicare beneficiaries.

    PubMed

    Modhia, Urvij; Takemoto, Steven; Braid-Forbes, Mary Jo; Weber, Michael; Berven, Sigurd H

    2013-04-01

    Retrospective observational cohort analysis of administrative claims. Estimate readmission rates after spine stenosis decompression surgery in a 5% randomly selected sample of Medicare beneficiaries. Operative management of lumbar spinal stenosis has significant and measurable benefits compared with nonoperative care. Revision rates for lumbar decompression with and without fusion have been reported with significant variability. An understanding of readmission and reoperation rates informs decisions regarding the cost-effective management of lumbar stenosis. Patients were identified in 2005-2009 Medicare claims who had both a procedure code for decompression (03.09), and a diagnosis of lumbar spinal stenosis (724.02). Patients diagnosed with spondylolisthesis, and those receiving revision surgery or fusion of more than 3 segments were excluded. Kaplan-Meier product limit method was used to estimate univariate rates of readmission for fusion, decompression, or injection and Cox proportional hazards to examine whether fusion decreased the likelihood of readmission. The overall 1-year readmission rate was slightly higher in patients undergoing fusion with decompression (9.7%) than patients who underwent decompression alone (7.2%, P = 0.03). Rates at 2 years were 14.6% and 12.5%, respectively. Patients receiving decompression with fusion were slightly younger and more likely female. Procedures performed during readmission were similar for the fusion and no fusion cohorts with 56% receiving fusion, 23% decompression, and 22% injection for pain management. Of the patients who were not readmitted, more than 25% of patients received outpatient injections for pain management during the 3-month quarter of their surgery and approximately 20% in the subsequent quarter. Readmission rates for spinal stenosis decompression were approximately 8% to 10% per year. Fusion at the index procedure did not protect against subsequent readmission. Large databases can inform choice of

  5. Magma decompression rates during explosive eruptions of Kīlauea volcano, Hawaii, recorded by melt embayments

    NASA Astrophysics Data System (ADS)

    Ferguson, David J.; Gonnermann, Helge M.; Ruprecht, Philipp; Plank, Terry; Hauri, Erik H.; Houghton, Bruce F.; Swanson, Donald A.

    2016-10-01

    The decompression rate of magma as it ascends during volcanic eruptions is an important but poorly constrained parameter that controls many of the processes that influence eruptive behavior. In this study, we quantify decompression rates for basaltic magmas using volatile diffusion in olivine-hosted melt tubes (embayments) for three contrasting eruptions of Kīlauea volcano, Hawaii. Incomplete exsolution of H2O, CO2, and S from the embayment melts during eruptive ascent creates diffusion profiles that can be measured using microanalytical techniques, and then modeled to infer the average decompression rate. We obtain average rates of ~0.05-0.45 MPa s-1 for eruptions ranging from Hawaiian style fountains to basaltic subplinian, with the more intense eruptions having higher rates. The ascent timescales for these magmas vary from around ~5 to ~36 min from depths of ~2 to ~4 km, respectively. Decompression-exsolution models based on the embayment data also allow for an estimate of the mass fraction of pre-existing exsolved volatiles within the magma body. In the eruptions studied, this varies from 0.1 to 3.2 wt% but does not appear to be the key control on eruptive intensity. Our results do not support a direct link between the concentration of pre-eruptive volatiles and eruptive intensity; rather, they suggest that for these eruptions, decompression rates are proportional to independent estimates of mass discharge rate. Although the intensity of eruptions is defined by the discharge rate, based on the currently available dataset of embayment analyses, it does not appear to scale linearly with average decompression rate. This study demonstrates the utility of the embayment method for providing quantitative constraints on magma ascent during explosive basaltic eruptions.

  6. Calculation of Decompression Rates for the Initial Explosive Phase of the 2010 Merapi Eruption

    NASA Astrophysics Data System (ADS)

    Matthews, E.; Genareau, K. D.

    2015-12-01

    The 2010 eruption of Merapi (Java, Indonesia) initiated with an uncharacteristic explosion, followed by rapid lava dome growth and collapse, all of which generated deadly pyroclastic density currents (PDCs). PDC samples from the initial explosion on October 26th were collected from several locations surrounding the edifice. Plagioclase phenocrysts represent the primary component of the dominant ash mode due to the elutriation of the finer ash fraction during PDC transport. Secondary electron images of 45 phenocrysts were taken using the scanning electron microscope (SEM) to examine preserved glass coatings on phenocrysts, which represent the interstitial melt within the magma at the point of fragmentation. Using these images, the bubble number densities (BNDs) were determined, and the decompression rate meter of Toramaru (2006) was used to calculate the decompression rate during the initial explosion of the 2010 Merapi eruption. Calculated decompression rates range from 6.08x10^7 Pa/s to 1.4x10^8 Pa/s. Decompression rates have shown to correlate with eruption column height; therefore Merapi's rates should be similar to those of other Vulcanian explosions, because the eruption column was 8-9 km in height. The decompression rates acquired for Merapi using Toramaru's BND meter are higher than the rates calculated with other methods such as microlite number density and extension cracks in crystals. Sakurajima volcano (Japan) experienced decompression rates from 7.0 × 10^3 to 7.8 × 10^4 Pa/s during the later phase of the fall 2011 Vulcanian explosions. Plinian explosions, such as at the 1991 eruption of Mt. Pinatubo and the 1980 eruption of St. Helens had much higher column heights compared to the initial 2010 Merapi explosion; 35 km, 19 km, and 8-9 km, respectively, but decompression rates in a comparative range (10^8 Pa/s). Higher decompression rates during the 2010 initial explosion at Merapi likely resulted from increased overpressure in the shallow conduit, the

  7. General Purpose Graphics Processing Unit Based High-Rate Rice Decompression and Reed-Solomon Decoding

    SciTech Connect

    Loughry, Thomas A.

    2015-02-01

    As the volume of data acquired by space-based sensors increases, mission data compression/decompression and forward error correction code processing performance must likewise scale. This competency development effort was explored using the General Purpose Graphics Processing Unit (GPGPU) to accomplish high-rate Rice Decompression and high-rate Reed-Solomon (RS) decoding at the satellite mission ground station. Each algorithm was implemented and benchmarked on a single GPGPU. Distributed processing across one to four GPGPUs was also investigated. The results show that the GPGPU has considerable potential for performing satellite communication Data Signal Processing, with three times or better performance improvements and up to ten times reduction in cost over custom hardware, at least in the case of Rice Decompression and Reed-Solomon Decoding.

  8. Effect of nitric oxide on spinal evoked potentials and survival rate in rats with decompression sickness.

    PubMed

    Randsoe, T; Meehan, C F; Broholm, H; Hyldegaard, O

    2015-01-01

    Nitric oxide (NO) releasing agents have, in experimental settings, been shown to decrease intravascular nitrogen bubble formation and to increase the survival rate during decompression sickness (DCS) from diving. The effect has been ascribed to a possible removal of preexisting micronuclei or an increased nitrogen washout on decompression through augmented blood flow rate. The present experiments were conducted to investigate whether a short- or long-acting NO donor [glycerol trinitrate (GTN) or isosorbide-5-mononitrate (ISMN), respectively] would offer the same protection against spinal cord DCS evaluated by means of spinal evoked potentials (SEPs). Anesthetized rats were decompressed from a 1-h hyperbaric air dive at 506.6 kPa (40 m of seawater) for 3 min and 17 s, and spinal cord conduction was studied by measurements of SEPs. Histological samples of the spinal cord were analyzed for lesions of DCS. In total, 58 rats were divided into 6 different treatment groups. The first three received either saline (group 1), 300 mg/kg iv ISMN (group 2), or 10 mg/kg ip GTN (group 3) before compression. The last three received either 300 mg/kg iv ISMN (group 4), 1 mg/kg iv GTN (group 5), or 75 μg/kg iv GTN (group 6) during the dive, before decompression. In all groups, decompression caused considerable intravascular bubble formation. The ISMN groups showed no difference compared with the control group, whereas the GTN groups showed a tendency toward faster SEP disappearance and shorter survival times. In conclusion, neither a short- nor long-acting NO donor had any protective effect against fatal DCS by intravenous bubble formation. This effect is most likely due to a fast ascent rate overriding the protective effects of NO, rather than the total inert tissue gas load. Copyright © 2015 the American Physiological Society.

  9. Self-rated readiness for performance of needle decompression in combat lifesaver training.

    PubMed

    Studer, Nicholas M; Horn, Gregory T; Armstrong, John H

    2013-11-01

    The Combat Lifesaver course taught to nonmedical personnel includes instruction on performing needle thoracostomy to decompress tension pneumothorax, the second leading cause of preventable combat death. Although the Tactical Combat Casualty Care curriculum is pushed to the lowest level of battlefield first responders, the instruction of this advanced procedure is routinely limited to a verbal block of instruction with a standardized presentation. The purpose of this study was to assess the confidence of nonmedical personnel in their preparation to perform a needle thoracostomy before Combat Lifesaver training, after verbal instruction on the procedure, manikin training, and practice on a human cadaver. Confidence was assessed by Likert scale surveys, as well as free response remarks collected before and after training. Self-rated preparedness scores improved significantly with each level of training. Maximal improvements followed cadaver training, from a mean score of 2.31/5 before instruction to 4.75/5 following cadaver training (matched pairs t test: p < 0.005). Cadaver training provided the largest single educational confidence boost for needle decompression skills, and is an effective method of enhancing confidence in needle decompression. Reprint & Copyright © 2013 Association of Military Surgeons of the U.S.

  10. Forecasting Effusive Dynamics and Decompression Rates by Magmastatic Model at Open-vent Volcanoes.

    PubMed

    Ripepe, Maurizio; Pistolesi, Marco; Coppola, Diego; Delle Donne, Dario; Genco, Riccardo; Lacanna, Giorgio; Laiolo, Marco; Marchetti, Emanuele; Ulivieri, Giacomo; Valade, Sébastien

    2017-06-20

    Effusive eruptions at open-conduit volcanoes are interpreted as reactions to a disequilibrium induced by the increase in magma supply. By comparing four of the most recent effusive eruptions at Stromboli volcano (Italy), we show how the volumes of lava discharged during each eruption are linearly correlated to the topographic positions of the effusive vents. This correlation cannot be explained by an excess of pressure within a deep magma chamber and raises questions about the actual contributions of deep magma dynamics. We derive a general model based on the discharge of a shallow reservoir and the magmastatic crustal load above the vent, to explain the linear link. In addition, we show how the drastic transition from effusive to violent explosions can be related to different decompression rates. We suggest that a gravity-driven model can shed light on similar cases of lateral effusive eruptions in other volcanic systems and can provide evidence of the roles of slow decompression rates in triggering violent paroxysmal explosive eruptions, which occasionally punctuate the effusive phases at basaltic volcanoes.

  11. The effects of different rates of ascent on the incidence of altitude decompression sickness

    NASA Technical Reports Server (NTRS)

    Kumar, K. V.; Waligora, James M.

    1989-01-01

    The effect of different rates of ascent on the incidence of altitude decompression sickness (DCS) was analyzed by a retrospective study on 14,123 man-flights involving direct ascent up to 38,000 ft altitude. The data were classified on the basis of altitude attained, denitrogenation at ground level, duration of stay at altitude, rest or exercise while at altitude, frequency of exercise at altitude, and ascent rates. This database was further divided on the basis of ascent rates into different groups from 1000 ft/min up to 53,000 ft/min. The database was analyzed using multiple correlation and regression methods, and the results of the analysis reveal that ascent rates influence the incidence of DCS in combination with the various factors mentioned above. Rate of ascent was not a significant predictor of DCS and showed a low, but significant multiple correlation (R=0.31) with the above factors. Further, the effects of rates below 2500 ft/min are significantly different from that of rates above 2500 ft/min on the incidence of symptoms (P=0.03) and forced descent (P=0.01). At rates above 2500 ft/min and up to 53,000 ft/min, the effects of ascent rates are not significantly different (P greater than 0.05) in the population examined while the effects of rates below 2500 ft/min are not clear.

  12. Extreme lateral interbody fusion relieves symptoms of spinal stenosis and low-grade spondylolisthesis by indirect decompression in complex patients.

    PubMed

    Pereira, Erlick A C; Farwana, Mohammad; Lam, Khai S

    2017-01-01

    Spinal stenosis and low-grade spondylolisthesis produce symptoms of neural compression that can be treated with extreme lateral lumbar interbody fusion (XLIF) via indirect decompression. This study aimed to investigate whether the restoration of disc dimensions would relieve symptoms of radiculopathy, claudication and back pain. In this retrospective study, patients undergoing XLIF surgery for relief of radicular symptoms or degenerative disc disease were included. Radiologically proven changes were used to assess the modes of degeneration. Objective measures such as the Visual Analogue Scale (VAS) for back and legs and the Oswestry Disability Index (ODI) were used. Complications were collated post-operatively from clinical notes and outpatient appointments. Twenty-three consecutive patients were included, of whom 91% had spinal stenosis. The cohort presented with multiple comorbidities and 35% of the cohort had undergone previous lumbar surgery. There was a 61% improvement of coronal Cobb angle and an 11% correction of the lordosis sustained 1year after surgery. Clinical outcomes at 1year showed 39%, 50% and 60% improvements in the ODI, back and leg VAS scores respectively. 48% of patients had reduced sensation related to lumbosacral plexus manipulation and one retroperitoneal haematoma was conservatively managed. Minimally invasive spinal (MIS) XLIF resulted in effective restoration of disc dimensions via indirect decompression, providing good relief of clinical symptoms evidenced by significant improvement in clinical outcome scores. XLIF corrected scoliosis and improved lumbar lordosis significantly. Several plexopathies did not hinder long-term recovery. XLIF is highly suited to treating complex patients with multiple comorbidities and degenerative disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Illustration of Cost Saving Implications of Lower Extremity Nerve Decompression to Prevent Recurrence of Diabetic Foot Ulceration

    PubMed Central

    Rankin, Timothy M.; Miller, John D.; Gruessner, Angelika C.; Nickerson, D. Scott

    2015-01-01

    The US diabetic foot ulcer (DFU) incidence is 3-4% of 22.3 million diagnosed diabetes cases plus 6.3 million undiagnosed, 858 000 cases total. Risk of recurrence after healing is 30% annually. Lower extremity multiple nerve decompression (ND) surgery reduces neuropathic DFU (nDFU) recurrence risk by >80%. Cost effectiveness of hypothetical ND implementation to minimize nDFU recurrence is compared to the current $6.171 billion annual nDFU expense. A literature review identified best estimates of annual incidence, recurrence risk, medical management expense, and noneconomic costs for DFU. Illustrative cost/benefit calculations were performed assuming widespread application of bilateral ND after wound healing to the nDFU problem, using Center for Medicare Services mean expense data of $1143/case for unilateral lower extremity ND. Calculations use conservative, evidence-based cost figures, which are contemporary (2012) or adjusted for inflation. Widespread adoption of ND after nDFU healing could reduce annual DFU occurrences by at least 21% in the third year and 24% by year 5, representing calculated cost savings of $1.296 billion (year 3) to $1.481 billion (year 5). This scenario proffers significant expense reduction and societal benefit, and represents a minimum 1.9× return on the investment cost for surgical treatment. Further large cost savings would require reductions in initial DFU incidence, which ND might achieve by selective application to advanced diabetic sensorimotor polyneuropathy (DSPN). By minimizing the contribution of recurrences to yearly nDFU incidence, ND has potential to reduce by nearly $1 billion the annual cost of DFU treatment in the United States. PMID:26055081

  14. Decompression and decompression sickness.

    PubMed

    Mahon, Richard T; Regis, David P

    2014-07-01

    The ever-present desire of humankind to explore new limits introduced us to the syndrome of decompression sickness (DCS). This broad overview of DCS is aimed at its pathophysiology and basics of therapeutic strategies. After a brief explanation of decompression theory, historical vignettes will serve to inform the practical application of our increasing understanding of DCS risks. The pathophysiology, current practices, role of bubble monitoring, risk factors, and potential long-term effects of DCS are also discussed. The goal is to explain the current state of DCS understanding in the context of a robust observational and empirical history. However, DCS remains a syndrome consisting of a constellation of symptoms following a change in ambient pressure. Though great strides have been made, significant knowledge gaps remain. If the coming years advance the field even a fraction of what its predecessors accomplished, the health and safety of those who endeavor in the environment of changing pressures most certainly will be improved.

  15. High magma decompression rates at the peak of a violent caldera-forming eruption (Lower Pumice 1 eruption, Santorini, Greece)

    NASA Astrophysics Data System (ADS)

    Simmons, J. M.; Carey, R. J.; Cas, R. A. F.; Druitt, T. H.

    2017-06-01

    We use the deposit sequence resulting from the first catastrophic caldera collapse event recorded at Santorini (associated with 184 ka Lower Pumice 1 eruption), to study the shallow conduit dynamics at the peak of caldera collapse. The main phase of the Lower Pumice 1 eruption commenced with the development of a sustained buoyant eruption column, producing a clast-supported framework of rhyodacitic white pumice (LP1-A). The clasts have densities of 310-740 kg m-3, large coalesced vesicles that define unimodal size distributions and moderate to high vesicle number densities (1.2 × 109-1.7 × 109 cm-3). Eruption column collapse, possibly associated with incipient caldera collapse, resulted in the development of pyroclastic flows (LP1-B). The resulting ignimbrite is characterised by rhyodacitic white pumice with a narrow density range (250-620 kg m-3) and moderate to high vesicle number densities (1.3 × 109-2.1 × 109 cm-3), comparable to clasts from LP1-A. An absence of deep, basement-derived lithic clast assemblages, together with the occurrence of large vesicles and relatively high vesicle number densities in pumice from the fallout and pyroclastic flow phases, suggests shallow fragmentation depths, a prolonged period of bubble nucleation and growth, and moderate rates of decompression prior to fragmentation (7-11 MPa s-1). Evacuation of magma during the pyroclastic flow phase led to under-pressurisation of the magma reservoir, the propagation of faults (associated with the main phase of caldera collapse) and the formation of 20 m thick lithic lag breccias (LP1-C). Rhyodacitic pumices from the base of the proximal lithic lag breccias show a broader range of density (330-990 kg m-3), higher vesicle number densities (4.5 × 109-1.1 × 1010 cm-3) and higher calculated magma decompression rates of 15-28 MPa s-1 than pyroclasts from the pre-collapse eruptive phases. In addition, the abundance of lithic clasts, including deeper, basement-derived lithic assemblages

  16. Magmatic storage conditions, decompression rate, and incipient caldera collapse of the 1902 eruption of Santa Maria Volcano, Guatemala

    NASA Astrophysics Data System (ADS)

    Andrews, Benjamin J.

    2014-08-01

    Phase equilibria experiments and analysis of natural pumice and phenocryst compositions indicate the 1902 Santa Maria dacite was stored at ~ 140-170 MPa and 840-850 °C prior to eruption. H2O-saturated, cold-seal experiments conducted in vessels with an intrinsic log fO2 of NNO + 1 ± 0.5 show that the natural phase assemblage (melt + plagioclase + amphibole + orthopyroxene + Fe-Ti oxides + apatite) is stable from approximately 115-140 MPa at temperatures below ~ 825 °C, to ~ 840-860 °C at 150 MPa, to > 850 and < 875 °C at 200 MPa. Natural plagioclase phenocrysts have rim compositions that range from An40-An45; this range of compositions defines a ~ 20 °C band that intersects the stable phase assemblage at ~ 150 MPa and 850 °C. Plagioclase hosted melt inclusions were analyzed using FTIR and commonly contain < 5 wt.% H2O, which corresponds to a pressure of ~ 170 MPa at 850 °C, under pure H2O saturated conditions. Amphibole geothermobarometry (Ridolfi et al., 2010) applied to experimental samples suggest two populations of amphiboles, phenocrysts grown during the experiments and inherited xenocrysts, but the pressure-temperature conditions returned by the geothermobarometer are routinely > 50 MPa and > 50 °C greater than experimental run conditions; precise estimates of magmatic conditions based solely upon amphibole composition are likely inaccurate. The experimental results and analysis of natural crystals suggest that although the natural amphiboles likely record a broad range of magmatic conditions, only the lower bounds of that range reflect pre-eruptive storage conditions. Comparison of Santa Maria microlite abundances with decompression experiments examining other silicic systems from the literature suggests that the 1902 dacite decompressed at the rate of ~ 0.005 to 0.01 MPa/s during the eruption. Applying the decompression rate with the previously described eruption rate of approximately 2-3 × 108 kg/s (Williams and Self, 1983; Carey and Sparks, 1986

  17. SEROTONIN AND OTHER VASOACTIVE AGENTS IN EXPERIMENTAL DECOMPRESSION SICKNESS,

    DTIC Science & Technology

    SEROTONIN, DECOMPRESSION SICKNESS), (*VASOACTIVE AGENTS, DECOMPRESSION SICKNESS), RATS, EXERCISE(PHYSIOLOGY), DOSAGE, CHEMOTHERAPEUTIC AGENTS, BLOOD ANALYSIS, TOXICITY, BLOOD CIRCULATION, MORTALITY RATES , CANADA

  18. Optic Nerve Decompression

    MedlinePlus

    ... Nerve Decompression Dacryocystorhinostomy (DCR) Disclosure Statement Printer Friendly Optic Nerve Decompression John Lee, MD Introduction Optic nerve decompression is a surgical procedure aimed at ...

  19. Future increases in extreme precipitation exceed observed scaling rates

    NASA Astrophysics Data System (ADS)

    Bao, Jiawei; Sherwood, Steven C.; Alexander, Lisa V.; Evans, Jason P.

    2017-01-01

    Models and physical reasoning predict that extreme precipitation will increase in a warmer climate due to increased atmospheric humidity. Observational tests using regression analysis have reported a puzzling variety of apparent scaling rates including strong rates in midlatitude locations but weak or negative rates in the tropics. Here we analyse daily extreme precipitation events in several Australian cities to show that temporary local cooling associated with extreme events and associated synoptic conditions reduces these apparent scaling rates, especially in warmer climatic conditions. A regional climate projection ensemble for Australia, which implicitly includes these effects, accurately and robustly reproduces the observed apparent scaling throughout the continent for daily precipitation extremes. Projections from the same model show future daily extremes increasing at rates faster than those inferred from observed scaling. The strongest extremes (99.9th percentile events) scale significantly faster than near-surface water vapour, between 5.7-15% °C-1 depending on model details. This scaling rate is highly correlated with the change in water vapour, implying a trade-off between a more arid future climate or one with strong increases in extreme precipitation. These conclusions are likely to generalize to other regions.

  20. Revisiting Hemicraniectomy: Late Decompressive Hemicraniectomy for Malignant Middle Cerebral Artery Stroke and the Role of Infarct Growth Rate

    PubMed Central

    Akhtar, Naveed; Salam, Abdul; Alboudi, Ayman; Kamran, Kainat; Ahmed, Arsalan; Khan, Rabia A.; Mirza, Mohsin K.; Inshasi, Jihad

    2017-01-01

    Objective and Methods. The outcome in late decompressive hemicraniectomy in malignant middle cerebral artery stroke and the optimal timings of surgery has not been addressed by the randomized trials and pooled analysis. Retrospective, multicenter, cross-sectional study to measure outcome following DHC under 48 or over 48 hours using the modified Rankin scale [mRS] and dichotomized as favorable ≤4 or unfavorable >4 at three months. Results. In total, 137 patients underwent DHC. Functional outcome analyzed as mRS 0–4 versus mRS 5-6 showed no difference in this split between early and late operated on patients [P = 0.140] and mortality [P = 0.975]. Multivariate analysis showed that age ≥ 55 years, MCA with additional infarction, septum pellucidum deviation ≥1 cm, and uncal herniation were independent predictors of poor functional outcome at three months. In the “best” multivariate model, second infarct growth rate [IGR2] >7.5 ml/hr, MCA with additional infarction, and patients with temporal lobe involvement were independently associated with surgery under 48 hours. Both first infarct growth rate [IGR1] and second infarct growth rate [IGR2] were nearly double [P < 0.001] in patients with early surgery [under 48 hours]. Conclusions. The outcome and mortality in malignant middle cerebral artery stroke patients operated on over 48 hours of stroke onset were comparable to those of patients operated on less than 48 hours after stroke onset. Our data identifies IGR, temporal lobe involvement, and middle cerebral artery with additional infarct as independent predictors for early surgery. PMID:28409051

  1. Extreme-value dependence: An application to exchange rate markets

    NASA Astrophysics Data System (ADS)

    Fernandez, Viviana

    2007-04-01

    Extreme value theory (EVT) focuses on modeling the tail behavior of a loss distribution using only extreme values rather than the whole data set. For a sample of 10 countries with dirty/free float regimes, we investigate whether paired currencies exhibit a pattern of asymptotic dependence. That is, whether an extremely large appreciation or depreciation in the nominal exchange rate of one country might transmit to another. In general, after controlling for volatility clustering and inertia in returns, we do not find evidence of extreme-value dependence between paired exchange rates. However, for asymptotic-independent paired returns, we find that tail dependency of exchange rates is stronger under large appreciations than under large depreciations.

  2. Decompression Theory.

    DTIC Science & Technology

    1980-06-25

    new experiments at 30 m ( 4 ATA) is appropriate for comparing N2 and He with respect to half times and surfacing ratios. Table 4 demonstrates the...THEORY C4 i t44 4 ’I9 41-*1 ai4 p80 7 10 009 UM"tUBNC*nm N4MDOf 29WS (DT) 6-25-80 The Seventeenth Undersea Medical Society Workshop DECOMPRESSION...Hamilton, Jr., Ph.D. Edward L Beckman, M.D. Hamilton Research Ltd. University of Hawaii 80 Grove Street School of Medicine Tarrytown, New York 10591

  3. Lethality and injuring the effect of compression and decompression rates of high hydrostatic pressure on Escherichia coli O157:H7 in different matrices

    NASA Astrophysics Data System (ADS)

    Syed, Qamar Abbas; Buffa, Martin; Guamis, Buenaventura; Saldo, Jordi

    2013-03-01

    The effect of compression and decompression rates of high hydrostatic pressure (HHP) on Escherichia coli O157:H7 was investigated. Samples of orange juice, skimmed milk and Tris buffer were inoculated with E. coli O157:H7 and subjected to 600 MPa for 3 min at 4°C with fast, medium and slow compression and decompression. Analyses immediately after HHP treatment revealed that E. coli in milk and juice treated with fast compression suffered more than slow compression rates. Slow decompression resulted in higher inactivation of E. coli in all matrices. After overnight storage, highest stress-recovery (1.19 log cfu/mL) was observed in Tris buffer. Healthy cells were<1 log cfu/mL in milk and buffer samples, but no growth was detected in orange juice for any of the treatments immediately after HHP. After 15 days at 4°C, E. coli cells in skimmed milk and Tris buffer recovered significantly, whereas the recovery of sublethally injured cells was inhibited in orange juice.

  4. Solidification at the High and Low Rate Extreme

    SciTech Connect

    Meco, Halim

    2004-12-19

    The microstructures formed upon solidification are strongly influenced by the imposed growth rates on an alloy system. Depending on the characteristics of the solidification process, a wide range of growth rates is accessible. The prevailing solidification mechanisms, and thus the final microstructure of the alloy, are governed by these imposed growth rates. At the high rate extreme, for instance, one can have access to novel microstructures that are unattainable at low growth rates. While the low growth rates can be utilized for the study of the intrinsic growth behavior of a certain phase growing from the melt. Although the length scales associated with certain processes, such as capillarity, and the diffusion of heat and solute, are different at low and high rate extremes, the phenomena that govern the selection of a certain microstructural length scale or a growth mode are the same. Consequently, one can analyze the solidification phenomena at both high and low rates by using the same governing principles. In this study, we examined the microstructural control at both low and high extremes. For the high rate extreme, the formation of crystalline products and factors that control the microstructure during rapid solidification by free-jet melt spinning are examined in Fe-Si-B system. Particular attention was given to the behavior of the melt pool at different quench-wheel speeds. Since the solidification process takes place within the melt-pool that forms on the rotating quench-wheel, we examined the influence of melt-pool dynamics on nucleation and growth of crystalline solidification products and glass formation. High-speed imaging of the melt-pool, analysis of ribbon microstructure, and measurement of ribbon geometry and surface character all indicate upper and lower limits for melt-spinning rates for which nucleation can be avoided, and fully amorphous ribbons can be achieved. Comparison of the relevant time scales reveals that surface-controlled melt

  5. Cardiopulmonary Changes with Moderate Decompression in Rats

    NASA Technical Reports Server (NTRS)

    Robinson, R.; Little, T.; Doursout, M.-F.; Butler, B. D.; Chelly, J. E.

    1996-01-01

    Sprague-Dawley rats were compressed to 616 kPa for 120 min then decompressed at 38 kPa/min to assess the cardiovascular and pulmonary responses to moderate decompression stress. In one series of experiments the rats were chronically instrumented with Doppler ultrasonic probes for simultaneous measurement of blood pressure, cardiac output, heart rate, left and right ventricular wall thickening fraction, and venous bubble detection. Data were collected at base-line, throughout the compression/decompression protocol, and for 120 min post decompression. In a second series of experiments the pulmonary responses to the decompression protocol were evaluated in non-instrumented rats. Analyses included blood gases, pleural and bronchoalveolar lavage (BAL) protein and hemoglobin concentration, pulmonary edema, BAL and lung tissue phospholipids, lung compliance, and cell counts. Venous bubbles were directly observed in 90% of the rats where immediate post-decompression autopsy was performed and in 37% using implanted Doppler monitors. Cardiac output, stroke volume, and right ventricular wall thickening fractions were significantly decreased post decompression, whereas systemic vascular resistance was increased suggesting a decrease in venous return. BAL Hb and total protein levels were increased 0 and 60 min post decompression, pleural and plasma levels were unchanged. BAL white blood cells and neutrophil percentages were increased 0 and 60 min post decompression and pulmonary edema was detected. Venous bubbles produced with moderate decompression profiles give detectable cardiovascular and pulmonary responses in the rat.

  6. Extreme variations of air dose rates in east Fukushima.

    PubMed

    Akimoto, Kazuhiro

    2015-11-01

    This report analyses the data of air (ambient) dose rates measured at 164 points in eastern Fukushima during a period of half a year after 10 June 2011. It is found that at some locations the values decreased or increased extraordinarily although on average the overall dose rates decreased significantly faster than the theoretically predicted rate. Among them the nine most extreme points are selected and analysed. It is found that behind these extraordinary behaviours of air dose rates there exists the combination of wind/rain and artificial structures such as sloped pavements. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Neurological Recovery Determined by C-Reactive Protein, Erythrocyte Sedimentation Rate and Two Different Posterior Decompressive Surgical Procedures: A Retrospective Clinical Study of Patients with Spinal Tuberculosis.

    PubMed

    Sudprasert, Weera; Piyapromdee, Urawit; Lewsirirat, Supphamard

    2015-10-01

    C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) not only are useful in the diagnosis but also are reliable parameters in evaluating the response to treatment and prognosis of tuberculous spondylodiscitis. To analyze the correlation between neurological recovery and declination of CRP or ESR after two different posterior spinal procedures. The patients who had neurological deficit due to spinal tuberculosis and undergone spinal surgery between January 2009 and June 2013 were analyzed retrospectively. Posterior transforaminal decompression and interbody fusion were done in group I, whereas posterior transpedicular decompression and posterolateralfusion were performed on group II. Both groups were stabilized with pedicle screw instrumentation. Rapid recovery represented by improvement of at least one Frankel grade within 6 weeks after operation, otherwise it was slow recovery. Inflammatory markers were evaluated at initial diagnosis and at 6-week, 3-month, 6-month, and 1-year post-operation. There were 31 patients. Group I included 14 cases and group II consisted of 17 cases. The median CRP and ESR at diagnosis were 80.4 mg/L and 78.0 mm/hour respectively. Rapid neurological recovery significantly related to the earlier declination of CRP within the first 6 weeks (p < 0.001). Considering the type of spinal procedures especially at thoracic and thoracolumbar level, neurological recovery in group I was significantly faster than in group II (p = 0.02; relative risk, 2.67; 95% confidence interval, 1.02 to 6.91). Earlier declination of CRP within six weeks post-operation could determine rapid neurological recovery. Posterior transforaminal decompression and interbody fusion with instrumentation may be a suitable optionfor thoracic and thoracolumbar lesions.

  8. After microvascular decompression to treat trigeminal neuralgia, both immediate pain relief and recurrence rates are higher in patients with arterial compression than with venous compression.

    PubMed

    Shi, Lei; Gu, Xiaoyan; Sun, Guan; Guo, Jun; Lin, Xin; Zhang, Shuguang; Qian, Chunfa

    2017-01-20

    We explored differences in postoperative pain relief achieved through decompression of the trigeminal nerve compressed by arteries and veins. Clinical characteristics, intraoperative findings, and postoperative curative effects were analyzed in 72 patients with trigeminal neuralgia who were treated by microvascular decompression. The patients were divided into arterial and venous compression groups based on intraoperative findings. Surgical curative effects included immediate relief, delayed relief, obvious reduction, and invalid result. Among the 40 patients in the arterial compression group, 32 had immediate pain relief of pain (80.0%), 5 cases had delayed relief (12.5%), and 3 cases had an obvious reduction (7.5%). In the venous compression group, 12 patients had immediate relief of pain (37.5%), 13 cases had delayed relief (40.6%), and 7 cases had an obvious reduction (21.9%). During 2-year follow-up period, 6 patients in the arterial compression group experienced recurrence of trigeminal neuralgia, but there were no recurrences in the venous compression group. Simple artery compression was followed by early relief of trigeminal neuralgia more often than simple venous compression. However, the trigeminal neuralgia recurrence rate was higher in the artery compression group than in the venous compression group.

  9. After microvascular decompression to treat trigeminal neuralgia, both immediate pain relief and recurrence rates are higher in patients with arterial compression than with venous compression

    PubMed Central

    Qian, Chunfa

    2017-01-01

    We explored differences in postoperative pain relief achieved through decompression of the trigeminal nerve compressed by arteries and veins. Clinical characteristics, intraoperative findings, and postoperative curative effects were analyzed in 72 patients with trigeminal neuralgia who were treated by microvascular decompression. The patients were divided into arterial and venous compression groups based on intraoperative findings. Surgical curative effects included immediate relief, delayed relief, obvious reduction, and invalid result. Among the 40 patients in the arterial compression group, 32 had immediate pain relief of pain (80.0%), 5 cases had delayed relief (12.5%), and 3 cases had an obvious reduction (7.5%). In the venous compression group, 12 patients had immediate relief of pain (37.5%), 13 cases had delayed relief (40.6%), and 7 cases had an obvious reduction (21.9%). During 2-year follow-up period, 6 patients in the arterial compression group experienced recurrence of trigeminal neuralgia, but there were no recurrences in the venous compression group. Simple artery compression was followed by early relief of trigeminal neuralgia more often than simple venous compression. However, the trigeminal neuralgia recurrence rate was higher in the artery compression group than in the venous compression group. PMID:28122347

  10. Enhancement of thermonuclear reaction rates in extremely dense stellar plasmas

    NASA Astrophysics Data System (ADS)

    Itoh, Naoki; Kuwashima, Fumiyoshi; Munakata, Hiroharu

    1990-10-01

    The enhancement factor of the thermonuclear reaction rates is calculated for the extremely dense stellar plasmas in the liquid phase where the condition 3Gamma/tau less than or equal to 1.6 is not necessarily imposed. Here the parameter 3Gamma/tau corresponds to the ratio of the classical turning point radius at the Gamow peak and the mean interionic distance in the case of the pure Coulomb potential. Direct double integration is carried out to obtain the thermonuclear reaction rates. The result is presented in the form of an analytic fitting formula to facilitate applications. The present fitting formula is valid for 3Gamma/tau = 0-5.4. The present calculation is intended to serve as the best available one for the case that ions are in the semiquantum regime.

  11. Solidification at the high and low rate extreme

    NASA Astrophysics Data System (ADS)

    Meco, Halim

    The microstructure selection at both high and low growth rates is studied. For the high rate extreme, melt spinning of a Fe-Si-B alloy is employed. The microstructural variations with changing wheel speed and factors affecting these variations are examined through various characterization techniques. Particular attention was given for the influence of melt pool behavior on the competition between nucleation of crystalline solidification products and glass formation. It is found that there exists a window of wheel speeds which give rise to a stable melt-pool and production of amorphous ribbons. The surface-controlled melt-pool oscillation is found as the dominant factor governing the onset of unsteady thermal conditions accompanied by varying amounts of crystalline nucleation observed near the lower wheel speed limit. For the upper wheel speed limit, a criterion based on mass-balance and momentum transfer is developed for predicting the window of wheel speeds for obtaining uniform and fully amorphous ribbons. For the low rate extreme, solidification and morphological selection of the faceted silicon phase is investigated in a near eutectic Al-Si system by utilizing a Bridgman type directional solidification unit. Particularly, the role of certain defect mechanisms namely, twinning, in the selection of microstructure and growth crystallography is investigated. At the imposed growth rates of 0.5 and 1 micron/s and temperature gradient of 7.5 K/mm, a unique silicon morphology consisting of 8-pointed stars is observed to grow with <001> texture within continuous domains across the sample. The growth crystallography of this unique silicon structure is characterized and it is found that substantial amount of {210} type twinning exists within the central core of this star-shaped morphology. It is found that the twinning phenomenon at the core is an essential feature for branching, morphological selection and adjustment of spacing between the star-like silicon features

  12. Improvement of long-term blindness caused by compression from inner-third sphenoid wing meningioma after optic canal decompression: An extremely rare case report

    PubMed Central

    Tamura, Ryota; Takahashi, Satoshi; Horikoshi, Tomo; Yoshida, Kazunari

    2016-01-01

    Background: There has been no previous case report of a patient whose visual acuity improved after long-term blindness caused by tumor invasion into the optic canal. Case Description: A 65-year-old Asian woman presented with a 6-month history of blindness caused by a meningioma located on the inner third of the sphenoid ridge. An operation was performed to prevent further tumor invasion into the cavernous sinus and contralateral optic nerve. During surgery, optic canal decompression was performed using an epidural approach. Subtotal removal of the tumor was achieved. Two days after the surgery, her left visual acuity recovered from blindness. Conclusion: Normally, long-term blindness caused by optic nerve compression by a brain tumor is regarded as irreversible, and even a surgical excision of the optic nerve is performed in some cases. However, because we experienced a case in which the patient recovered from long-term blindness after optic canal decompression, we believe that this surgical procedure should definitely be considered as an option. PMID:27413579

  13. Regional intensity of vascular care and lower extremity amputation rates

    PubMed Central

    Goodney, Philip P.; Holman, Kerianne; Henke, Peter K.; Travis, Lori L.; Dimick, Justin B.; Stukel, Therese A.; Fisher, Elliott. S.; Birkmeyer, John D.

    2013-01-01

    Objective To examine the relationship between the intensity of vascular care and population-based rate of major lower extremity amputation (above-or below-knee) from vascular disease. Background Because patient-level differences do not fully explain the variation in amputation rate across the United States, we hypothesized that variation in intensity of vascular care may also affect regional rates of amputation. Methods Intensity of vascular care was defined as the proportion of Medicare patients who underwent any vascular procedure in the year prior to amputation, calculated at the regional level (2003–2006), using the 306 hospital referral regions in the Dartmouth Atlas of Healthcare. We examined relationship between intensity of vascular care and major amputation rate, at the regional level, between 2007–2009. Results Amputation rates varied widely by region, from 1 to 27 per 10,000 Medicare patients. Compared to regions in the lowest quintile of amputation rate, patients in the highest quintile were commonly African American (50% versus 13%) and diabetic (38% versus 31%). Intensity of vascular care also varied across regions: fewer than 35% of patients underwent revascularization in the lowest quintile of intensity, while nearly 60% of patients underwent revascularization in the highest quintile. Overall, there was an inverse correlation between intensity of vascular care and amputation rate ranging from R= −0.36 for outpatient diagnostic and therapeutic procedures, to R= −0.87 for inpatient surgical revascularizations. In analyses adjusting for patient characteristics and socioeconomic status, patients in high vascular care regions were significantly less likely to undergo amputation without an antecedent attempt at revascularization (OR 0.37, 95% CI 0.34–0.37, p<0.001). Conclusions The intensity of vascular care provided to patients at risk for amputation varies, and regions with the most intensive vascular care have the lowest amputation rate

  14. Verification of nerve decompression using mechanomyography.

    PubMed

    Wessell, Nolan; Khalil, Jad; Zavatsky, Joseph; Ghacham, Wael; Bartol, Stephen

    2016-06-01

    Assessment of nerve root decompression in surgery is largely based on visualization and tactile feedback. Often times, visualization can be limited, such as in minimally invasive surgery, and tactile feedback is a subjective assessment that makes the evaluation of successful nerve decompression difficult. Electromyography (EMG) has been proposed as an assessment tool, but EMG responses are often difficult to quantify. Alternatively, mechanomyography (MMG) provides a quantifiable response with high signal-to-noise ratio compared with EMG. MMG provides a sensitive tool to accurately quantify mechanical responses to motor action potentials generated by electrical stimulus, allowing more reliable assessment of nerve decompression. The aim of this study was to assess the ability of MMG to quantitatively demonstrate successful nerve root decompression. Prospective cohort, Therapeutic Level III, Urban Level I Trauma Center. A total of 46 patients (72 affected nerve roots) undergoing decompression procedures for lower extremity radiculopathy caused by nerve root compression were enrolled in the study. The study population included 15 patients with herniated nucleus pulposus (HNP) and 31 with lateral recess stenosis (LRS). Visual analog scale (VAS) score. A total of 72 nerves roots in 46 patients undergoing lumbar decompression procedures, for lower extremity radicular symptoms, were tested using MMG. Nerves were stimulated upstream from the compression site, and the lowest threshold current needed to generate a muscle response was determined. Signal response sizes were recorded before and after decompression. VAS scores were collected pre- and postoperatively. Of the patients, 90% (65/72) had elevated stimulation thresholds (>1 milliamp [mA]) before decompression. After decompression, 98% of patients (64/65) with elevated current thresholds exhibited a drop in threshold of ≥1 mA (p<.001). A postdecompression increase in response amplitude was recorded in all patients

  15. Fusion rate following extreme lateral lumbar interbody fusion.

    PubMed

    Berjano, Pedro; Langella, Francesco; Damilano, Marco; Pejrona, Matteo; Buric, Josip; Ismael, Maryem; Villafañe, Jorge Hugo; Lamartina, Claudio

    2015-04-01

    Lumbar fusion has been found to be a clinically effective procedure in adult patients. The lateral transpsoas approach allows for direct visualization of the intervertebral space, significant support of the vertebral anterior column, while avoiding the complications associated with the posterior procedures. The aim of this study is to determine the fusion rate of inter body fusion using computed tomography in patients treated by extreme lateral intersomatic fusion (XLIF) technique. All patients intervened by XLIF procedure between 2009 and 2013 by a single operating team at a single institution were recruited for this study. A clinical evaluation and a CT scan of the involved spinal segments were then performed with at least 1-year follow-up following the standard clinical practice in the center. A total of 77 patients met inclusion criteria, of which 53 were available for review with a mean follow-up of 34.5 (12-62) months. A total of 68 (87.1 %) of the 78 operated levels were considered as completely fused, 8 (10.2 %) were considered as stable, probably fused, and 2 (2.6 %) of the operated levels were diagnosed as pseudarthrosis. When stratified by type of graft material complete fusion was obtained in 75 % of patients in which autograft was used to fill the cages, compared to 89 % of patients in which calcium triphosphate was used, and 83 % of patients in which Attrax™ was used. Reports of XLIF fusion rate in the literature vary from 85 to 93 % at 1-year follow-up. Fusion rate in our series corroborates data from previous publications. The results of this series confirm that anterior inter body fusion by means of XLIF approach is a technique that achieves high fusion rate and satisfactory clinical outcomes.

  16. Compressive phase-only filtering at extreme compression rates

    NASA Astrophysics Data System (ADS)

    Pastor-Calle, David; Pastuszczak, Anna; Mikołajczyk, Michał; Kotyński, Rafał

    2017-01-01

    We introduce an efficient method for the reconstruction of the correlation between a compressively measured image and a phase-only filter. The proposed method is based on two properties of phase-only filtering: such filtering is a unitary circulant transform, and the correlation plane it produces is usually sparse. Thanks to these properties, phase-only filters are perfectly compatible with the framework of compressive sensing. Moreover, the lasso-based recovery algorithm is very fast when phase-only filtering is used as the compression matrix. The proposed method can be seen as a generalization of the correlation-based pattern recognition technique, which is hereby applied directly to non-adaptively acquired compressed data. At the time of measurement, any prior knowledge of the target object for which the data will be scanned is not required. We show that images measured at extremely high compression rates may still contain sufficient information for target classification and localization, even if the compression rate is high enough, that visual recognition of the target in the reconstructed image is no longer possible. The method has been applied by us to highly undersampled measurements obtained from a single-pixel camera, with sampling based on randomly chosen Walsh-Hadamard patterns.

  17. Material dynamics under extreme conditions of pressure and strain rate

    SciTech Connect

    Remington, B A; Allen, P; Bringa, E; Hawreliak, J; Ho, D; Lorenz, K T; Lorenzana, H; Meyers, M A; Pollaine, S W; Rosolankova, K; Sadik, B; Schneider, M S; Swift, D; Wark, J; Yaakobi, B

    2005-09-06

    Solid state experiments at extreme pressures (10-100 GPa) and strain rates ({approx}10{sup 6}-10{sup 8}s{sup -1}) are being developed on high-energy laser facilities, and offer the possibility for exploring new regimes of materials science. These extreme solid-state conditions can be accessed with either shock loading or with a quasi-isentropic ramped pressure drive. Velocity interferometer measurements establish the high pressure conditions. Constitutive models for solid-state strength under these conditions are tested by comparing 2D continuum simulations with experiments measuring perturbation growth due to the Rayleigh-Taylor instability in solid-state samples. Lattice compression, phase, and temperature are deduced from extended x-ray absorption fine structure (EXAFS) measurements, from which the shock-induced {alpha}-{omega} phase transition in Ti and the {alpha}-{var_epsilon} phase transition in Fe are inferred to occur on sub-nanosec time scales. Time resolved lattice response and phase can also be measured with dynamic x-ray diffraction measurements, where the elastic-plastic (1D-3D) lattice relaxation in shocked Cu is shown to occur promptly (< 1 ns). Subsequent large-scale molecular dynamics (MD) simulations elucidate the microscopic dynamics that underlie the 3D lattice relaxation. Deformation mechanisms are identified by examining the residual microstructure in recovered samples. The slip-twinning threshold in single-crystal Cu shocked along the [001] direction is shown to occur at shock strengths of {approx}20 GPa, whereas the corresponding transition for Cu shocked along the [134] direction occurs at higher shock strengths. This slip-twinning threshold also depends on the stacking fault energy (SFE), being lower for low SFE materials. Designs have been developed for achieving much higher pressures, P > 1000 GPa, in the solid state on the National Ignition Facility (NIF) laser.

  18. Failed subacromial decompression. Risk factors.

    PubMed

    Bouchard, A; Garret, J; Favard, L; Charles, H; Ollat, D

    2014-12-01

    Arthroscopic subacromial decompression (acromioplasty) is widely held to be effective, although pain may persist after the procedure. The objective of this study was to evaluate the proportion of patients with residual pain (i.e., the failure rate) after isolated subacromial decompression and to look for predictors of failure. We conducted a retrospective multicentre study of 108 patients managed with isolated arthroscopic subacromial decompression between 2007 and 2011, for any reason. We excluded patients in whom surgical procedures on the rotator cuff tendons were performed concomitantly. Data were collected from the medical records, a telephone questionnaire, and radiographs obtained before surgery and at last follow-up. Failure was defined as persistent pain (visual analogue scale score>3) more than 6 months after surgery and at last follow-up. The failure rate was 29% (31/108). Two factors significantly predicted failure, namely, receiving workers' compensation benefits for the shoulder condition and co-planing. Heterogeneous calcific tendinopathy and deep partial-thickness rotator cuff tears were also associated with poorer outcomes, but the effect was not statistically significant. Co-planing may predict failure of subacromial decompression, although whether this effect is due to an insufficient degree of co-planing or to the technique itself is unclear. Nevertheless, in patients with symptoms from the acromio-clavicular joint, acromio-clavicular resection is probably the best option. Receiving workers' compensation benefits was also associated with treatment failure, as a result of well-known parameters related to the social welfare system. Isolated arthroscopic subacromial decompression is effective in 70% of cases. We recommend the utmost caution if co-planing is considered and/or the patient receives workers' compensation benefits for the shoulder condition, as these two factors are associated with a significant increase in the failure rate. IV

  19. Strain rate dependency of oceanic intraplate earthquake b-values at extremely low strain rates

    NASA Astrophysics Data System (ADS)

    Sasajima, Ryohei; Ito, Takeo

    2016-06-01

    We discovered a clear positive dependence of oceanic intraplate earthquake (OCEQ) b-values on the age of the oceanic lithosphere. OCEQ b-values in the youngest (<10 Ma) oceanic lithosphere are around 1.0, while those in middle to old (>20 Ma) oceanic lithosphere exceed 1.5, which is significantly higher than the average worldwide earthquake b-value (around 1.0). On the other hand, the b-value of intraplate earthquakes in the Ninety East-Sumatra orogen, where oceanic lithosphere has an anomalously higher strain rate compared with normal oceanic lithosphere, is 0.93, which is significantly lower than the OCEQ b-value (about 1.9) with the same age (50-110 Ma). Thus, the variation in b-values relates to the strain rate of the oceanic lithosphere and is not caused by a difference in thermal structure. We revealed a negative strain rate dependency of the b-value at extremely low strain rates (<2 × 10-10/year), which can clearly explain the above b-values. We propose that the OCEQ b-value depends strongly on strain rate (either directly or indirectly) at extremely low strain rates. The high OCEQ b-values (>1.5) in oceanic lithosphere >20 Ma old imply that future improvement in seismic observation will capture many smaller magnitude OCEQs, which will provide valuable information on the evolution of the oceanic lithosphere and the driving mechanism of plate tectonics.

  20. A Start Toward Micronucleus-Based Decompression Models; Altitude Decompression

    NASA Technical Reports Server (NTRS)

    Van Liew, H. D.; Conkin, Johnny

    2007-01-01

    Do gaseous micronuclei trigger the formation of bubbles in decompression sickness (DCS)? Most previous instructions for DCS prevention have been oriented toward supersaturated gas in tissue. We are developing a mathematical model that is oriented toward the expected behavior of micronuclei. The issue is simplified in altitude decompressions because the aviator or astronaut is exposed only to decompression, whereas in diving there is a compression before the decompression. The model deals with four variables: duration of breathing of 100% oxygen before going to altitude (O2 prebreathing), altitude of the exposure, exposure duration, and rate of ascent. Assumptions: a) there is a population of micronuclei of various sizes having a range of characteristics, b) micronuclei are stable until they grow to a certain critical nucleation radius, c) it takes time for gas to diffuse in or out of micronuclei, and d) all other variables being equal, growth of micronuclei upon decompression is more rapid at high altitude because of the rarified gas in the micronuclei. To estimate parameters, we use a dataset of 4,756 men in altitude chambers exposed to various combinations of the model s variables. The model predicts occurrence of DCS symptoms quite well. It is notable that both the altitude chamber data and the model show little effect of O2 prebreathing until it lasts more than 60 minutes; this is in contrast to a conventional idea that the benefit of prebreathing is directly due to exponential washout of tissue nitrogen. The delay in response to O2 prebreathing can be interpreted as time required for outward diffusion of nitrogen; when the micronuclei become small enough, they are disabled, either by crushing or because they cannot expand to a critical nucleation size when the subject ascends to altitude.

  1. Effects of Standard Extremity on Mixed Standard Scale Performance Ratings.

    DTIC Science & Technology

    1983-03-01

    affect the nature of performance ratins 1ei-ived from MSS responses and decisions based on M’S rat ings. 14Ieu h, ext rmit V 0 * standards was...experimental ly iani pulated , it was found thlat standard .extremity affects both tile level of performance rat inuis and the i)rolpor t i o • of logical ly...SIECURITY CLASSIFICATION OF THIS PAGE (When De4 &beter.f, SECURITY CLASSIFICATION OF THIS PAGE (w Daen V EnIreO0 extremity appears to affect the rankings on

  2. Endothelial dysfunction correlates with decompression bubbles in rats

    PubMed Central

    Zhang, Kun; Wang, Dong; Jiang, Zhongxin; Ning, Xiaowei; Buzzacott, Peter; Xu, Weigang

    2016-01-01

    Previous studies have documented that decompression led to endothelial dysfunction with controversial results. This study aimed to clarify the relationship between endothelial dysfunction, bubble formation and decompression rate. Rats were subjected to simulated air dives with one of four decompression rates: one slow and three rapid. Bubble formation was detected ultrasonically following decompression for two hours, before measurement of endothelial related indices. Bubbles were found in only rapid-decompressed rats and the amount correlated with decompression rate with significant variability. Serum levels of ET-1, 6-keto-PGF1α, ICAM-1, VCAM-1 and MDA, lung Wet/Dry weight ratio and histological score increased, serum NO decreased following rapid decompression. Endothelial-dependent vasodilatation to Ach was reduced in pulmonary artery rings among rapid-decompressed rats. Near all the above changes correlated significantly with bubble amounts. The results suggest that bubbles may be the causative agent of decompression–induced endothelial damage and bubble amount is of clinical significance in assessing decompression stress. Furthermore, serum levels of ET-1 and MDA may serve as sensitive biomarkers with the capacity to indicate endothelial dysfunction and decompression stress following dives. PMID:27615160

  3. Endoscopic Intermetatarsal Ligament Decompression.

    PubMed

    Lui, Tun Hing

    2015-12-01

    Morton neuroma is an entrapment of the intermetatarsal nerve by the deep intermetatarsal ligament. It is usually treated conservatively. Surgery is considered if there is recalcitrant pain that is resistant to conservative treatment. The surgical options include resection of the neuroma or decompression of the involved nerve. Decompression of the nerve by release of the intermetatarsal ligament can be performed by either an open or minimally invasive approach. We describe 2-portal endoscopic decompression of the intermetatarsal nerve. The ligament is released by a retrograde knife through the toe-web portal under arthroscopic guidance through the plantar portal.

  4. Estimating rates of decompression from textures of erupted ash particles produced by 1999-2006 eruptions of Tungurahua volcano, Ecuador

    USGS Publications Warehouse

    Wright, Heather M.N.; Cashman, Katharine V.; Mothes, Patricia A.; Hall, Minard L.; Ruiz, Andrés Gorki; Le Pennec, Jean-Luc

    2012-01-01

    Persistent low- to moderate-level eruptive activity of andesitic volcanoes is difficult to monitor because small changes in magma supply rates may cause abrupt transitions in eruptive style. As direct measurement of magma supply is not possible, robust techniques for indirect measurements must be developed. Here we demonstrate that crystal textures of ash particles from 1999 to 2006 Vulcanian and Strombolian eruptions of Tungurahua volcano, Ecuador, provide quantitative information about the dynamics of magma ascent and eruption that is difficult to obtain from other monitoring approaches. We show that the crystallinity of erupted ash particles is controlled by the magma supply rate (MSR); ash erupted during periods of high magma supply is substantially less crystalline than during periods of low magma supply. This correlation is most easily explained by efficient degassing at very low pressures (<<50 MPa) and degassing-driven crystallization controlled by the time available prior to eruption. Our data also suggest that the observed transition from intermittent Vulcanian explosions at low MSR to more continuous periods of Strombolian eruptions and lava fountains at high MSR can be explained by the rise of bubbles through (Strombolian) or trapping of bubbles beneath (Vulcanian) vent-capping, variably viscous (and crystalline) magma.

  5. Metabolism and decompression tolerance of scavenging lysianassoid deep-sea amphipods

    NASA Astrophysics Data System (ADS)

    Treude, Tina; Janßen, Felix; Queisser, Wolfgang; Witte, Ursula

    2002-07-01

    Respiration, ammonia excretion and decompression tolerance were studied in several species of lysianassoid amphipods captured at four stations in the deep Arabian Sea with an isolated trap maintaining them at in situ temperature. The amphipods were decompressed from their ambient to atmospheric pressure during recovery. Six amphipods, belonging to the species Eurythenes gryllus, Paralicella caperesca and Abyssorchomene abyssorum, survived decompression from depths between 1920 and 4420 m. The physiological condition of these specimens was good inferred by the fact that their swimming and resting behaviour appeared normal, they reacted to disturbance by light and vibration, and were able to ingest food to maintain full guts. Most of the amphipods (421 individuals), however, were recovered dead, which allows information about their decompression tolerance and their vertical migration ability to be deduced. Weight-specific respiration rates of the deep-sea amphipods that were fed prior to the experiments were not lower than in shallow-water amphipods living at similar temperatures. Differences in respiration rates between the specimens are discussed with regard to body size, species specificity and food supply. Weight-specific ammonia excretion rates were extremely high when compared with shallow-water relatives, indicating a capability for rapid digestion. This may be an adaptation to the unpredictable food supply in the deep sea as it enables the amphipod to empty its digestive tract quickly, thus making it available for additional food. Rapid digestion also enables the animals to regain mobility soon after feeding, permitting them to move to new food sources.

  6. Spall Response of Tantalum at Extreme Strain-Rates

    NASA Astrophysics Data System (ADS)

    Hahn, Eric; Germann, Tim; Meyers, Marc

    Strain-rate and microstructure play a significant role in the ultimate mechanical response of materials. Using non-equilibrium molecular dynamics simulations, we characterize the ductile tensile failure of single and nanocrystalline tantalum over multiple orders of magnitude of strain-rate. This comparison is extended to over nine orders of magnitude including experimental results from resent laser shock campaigns. Spall strength primarily follows a power law dependence with strain-rate over this extensive range. In all cases, voids nucleate heterogeneously at pre-existing defects. Predictions based on traditional theory suggest that, as strain-rate increases, tensile strength should increase. Alternatively, as grain size decreases, tensile strength may decrease due to an increased propensity to fail at a growing volume fraction of grain boundaries. Strain-rate and grain size dictate void nucleation sites by changing the type and density of available defects: vacancies, dislocations, twins, and grain boundaries.

  7. Rupture of the cell envelope by decompression of the deep-sea methanogen Methanococcus jannaschii.

    PubMed

    Park, Chan Beum; Clark, Douglas S

    2002-03-01

    The effect of decompression on the structure of Methanococcus jannaschii, an extremely thermophilic deep-sea methanogen, was studied in a novel high-pressure, high-temperature bioreactor. The cell envelope of M. jannaschii appeared to rupture upon rapid decompression (ca. 1 s) from 260 atm of hyperbaric pressure. When decompression from 260 atm was performed over 5 min, the proportion of ruptured cells decreased significantly. In contrast to the effect produced by decompression from hyperbaric pressure, decompression from a hydrostatic pressure of 260 atm did not induce cell lysis.

  8. Materials Science at the Extremes of Pressure and Strain Rate

    SciTech Connect

    Remington, B A; Cavallo, R M; Edwards, M J; Lasinski, B F; Lorenz, K T; Lorenzana, H E; McNaney, J; Pollaine, S M; Rowley, D P; Yaakobi, B

    2003-08-20

    Solid state experiments at very high pressures and strain rates are possible on high power laser facilities, albeit over brief intervals of time and spatial small scales. A new shockless drive has been developed on the Omega laser. VISAR measurements establish the high strain rates, 10{sup 7}-10{sup 8} s{sup -1}. Solid-state strength is inferred using the Rayleigh-Taylor instability as a ''diagnostic''. Temperature and compression in polycrystalline samples can be deduced from EXAFS measurements. Lattice response can be inferred from time-resolved x-ray diffraction. Deformation mechanisms can be identified by examining recovered samples. We will briefly review this new area of laser-based materials science research, then present a path forward for carrying these solid-state experiments to much higher pressures, P >> 1 Mbar, on the NIF laser facility.

  9. Materials Science under Extreme Conditions of Pressure and Strain Rate

    SciTech Connect

    Remington, B A; Bazan, G; Bringa, E; Caturla, M; Edwards, M J; Glendinning, S G; Kad, B; Kalantar, D H; Kumar, M; Lasinski, B F; Lorenz, K T; McNaney, J; Meyerhofer, D; Meyers, M A; Pollaine, S M; Reisman, D B; Rowley, D; Schneider, M; Stolken, J; Wark, J; Yaakobi, B

    2003-03-27

    Solid state dynamics experiments at very high pressures (P >> 10 GPa) and strain rates ({var_epsilon} >> 10{sup 5} s{sup -1}) have been demonstrated on high energy laser facilities, albeit over brief intervals of time and small spatial scales. We have developed two methods for driving samples to high pressures (10-100 GPa) at high strain rate (10{sup 6}-10{sup 8} s{sup -1}) in the solid state. One method uses a shockless compression technique, and the other uses multiple staged shocks. These drives are calibrated with VISAR measurements of the resulting compression wave. Deformation mechanisms are inferred under these conditions by characterizing recovered samples. Material strength at high pressures and strain rates is deduced by measuring the reduced growth of material perturbations at a hydrodynamically unstable interface. Microscopic lattice response is determined by time-resolved Bragg diffraction and x-ray absorption spectroscopy (EXAFS). Large-scale simulations, both at the continuum level using constitutive models and at the lattice level using molecular dynamics simulation, are used to interpret these integral experiments. We will review our progress in this new area of laser-based materials science research, then present a vision for carrying these solid-state experiments to much higher pressures, P > 1000 GPa, on the National Ignition Facility (NIF) laser facility.

  10. Cutaneous decompression sickness.

    PubMed

    Tasios, Konstantinos; Sidiras, Georgios Gr; Kalentzos, Vasileios; Pyrpasopoulou, Athina

    2014-03-01

    A probable case of decompression illness with associated cutis marmorata is presented, which regressed over a few hours with oxygen breathing and after intravenous methylprednisolone and fluid resuscitation without recompression. He was eventually transferred for hyperbaric treatment some 10 hours post dive. Cutaneous decompression illness is not associated with high mortality per se, but prompt and accurate recognition is warranted, as it may represent a prodromal feature of potentially life-threatening complications. However, in this case, as differential diagnosis, an allergic reaction remains possible.

  11. Paradoxical Herniation following Decompressive Craniectomy in the Subacute Setting

    PubMed Central

    Espinosa, Jose

    2016-01-01

    Decompressive craniectomy is reserved for extreme cases of intracranial hypertension. An uncommon complication known as paradoxical herniation has been documented within weeks to months following surgery. Here we present a unique case within days of surgery. Since standard medical treatment for intracranial hypertension will exacerbate paradoxical herniation, any abrupt neurological changes following decompressive craniectomy should be carefully investigated. Immediate treatment for paradoxical herniation is placement of the patient in the supine position with adequate hydration. Cranioplasty is the ultimate treatment option. PMID:27446619

  12. Outcome comparison of endoscopic and transpalpebral decompression for treatment of frontal migraine headaches.

    PubMed

    Liu, Mengyuan T; Chim, Harvey; Guyuron, Bahman

    2012-05-01

    This study was designed to compare the efficacy of the transpalpebral versus endoscopic approach to decompression of the supraorbital and supratrochlear nerves in patients with frontal migraine headaches. The medical charts of 253 patients who underwent surgery for frontal migraine headaches were reviewed. These patients underwent either transpalpebral nerve decompression (n = 62) or endoscopic nerve decompression (n = 191). Preoperative and 12-month or greater postoperative migraine frequency, duration, and intensity were analyzed to determine the success of the surgeries. Forty-nine of 62 patients (79 percent) in the transpalpebral nerve decompression group and 170 of 191 patients (89 percent) who underwent endoscopic nerve decompression experienced a successful outcome (at least a 50 percent decrease in migraine frequency, duration, or intensity) after 1 year from surgery. Endoscopic nerve decompression had a significantly higher success rate than transpalpebral nerve decompression (p < 0.05). Thirty-two patients (52 percent) in the transpalpebral nerve decompression group and 128 patients (67 percent) who underwent endoscopic nerve decompression observed elimination of migraine headaches. The elimination rate was significantly higher in the endoscopic nerve decompression group than in the transpalpebral nerve decompression group (p < 0.03). Endoscopic nerve decompression was found to be more successful at reducing or eliminating frontal migraine headaches than transpalpebral nerve decompression and should be selected as the first choice whenever it is anatomically feasible. Therapeutic, III.

  13. Delayed facial nerve decompression for Bell's palsy.

    PubMed

    Kim, Sang Hoon; Jung, Junyang; Lee, Jong Ha; Byun, Jae Yong; Park, Moon Suh; Yeo, Seung Geun

    2016-07-01

    Incomplete recovery of facial motor function continues to be long-term sequelae in some patients with Bell's palsy. The purpose of this study was to investigate the efficacy of transmastoid facial nerve decompression after steroid and antiviral treatment in patients with late stage Bell's palsy. Twelve patients underwent surgical decompression for Bell's palsy 21-70 days after onset, whereas 22 patients were followed up after steroid and antiviral therapy without decompression. Surgical criteria included greater than 90 % degeneration on electroneuronography and no voluntary electromyography potentials. This study was a retrospective study of electrodiagnostic data and medical chart review between 2006 and 2013. Recovery from facial palsy was assessed using the House-Brackmann grading system. Final recovery rate did not differ significantly in the two groups; however, all patients in the decompression group recovered to at least House-Brackmann grade III at final follow-up. Although postoperative hearing threshold was increased in both groups, there was no significant between group difference in hearing threshold. Transmastoid decompression of the facial nerve in patients with severe late stage Bell's palsy at risk for a poor facial nerve outcome reduced severe complications of facial palsy with minimal morbidity.

  14. Prospective comparison of long-term pain relief rates after first-time microvascular decompression and stereotactic radiosurgery for trigeminal neuralgia.

    PubMed

    Wang, Doris D; Raygor, Kunal P; Cage, Tene A; Ward, Mariann M; Westcott, Sarah; Barbaro, Nicholas M; Chang, Edward F

    2017-02-24

    OBJECTIVE Common surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD), stereotactic radiosurgery (SRS), and radiofrequency ablation (RFA). Although the efficacy of each procedure has been described, few studies have directly compared these treatment modalities on pain control for TN. Using a large prospective longitudinal database, the authors aimed to 1) directly compare long-term pain control rates for first-time surgical treatments for idiopathic TN, and 2) identify predictors of pain control. METHODS The authors reviewed a prospectively collected database for all patients who underwent treatment for TN between 1997 and 2014 at the University of California, San Francisco. Standardized collection of data on preoperative clinical characteristics, surgical procedure, and postoperative outcomes was performed. Data analyses were limited to those patients who received a first-time procedure for treatment of idiopathic TN with > 1 year of follow-up. RESULTS Of 764 surgical procedures performed at the University of California, San Francisco, for TN (364 SRS, 316 MVD, and 84 RFA), 340 patients underwent first-time treatment for idiopathic TN (164 MVD, 168 SRS, and 8 RFA) and had > 1 year of follow-up. The analysis was restricted to patients who underwent MVD or SRS. Patients who received MVD were younger than those who underwent SRS (median age 63 vs 72 years, respectively; p < 0.001). The mean follow-up was 59 ± 35 months for MVD and 59 ± 45 months for SRS. Approximately 38% of patients who underwent MVD or SRS had > 5 years of follow-up (60 of 164 and 64 of 168 patients, respectively). Immediate or short-term (< 3 months) postoperative pain-free rates (Barrow Neurological Institute Pain Intensity score of I) were 96% for MVD and 75% for SRS. Percentages of patients with Barrow Neurological Institute Pain Intensity score of I at 1, 5, and 10 years after MVD were 83%, 61%, and 44%, and the corresponding percentages after SRS were

  15. Cardiovascular Pressures with Venous Gas Embolism and Decompression

    NASA Technical Reports Server (NTRS)

    Butler, B. D.; Robinson, R.; Sutton, T.; Kemper, G. B.

    1995-01-01

    Venous gas embolism (VGE) is reported with decompression to a decreased ambient pressure. With severe decompression, or in cases where an intracardiac septal defect (patent foramen ovale) exists, the venous bubbles can become arterialized and cause neurological decompression illness. Incidence rates of patent foramen ovale in the general population range from 25-34% and yet aviators, astronauts, and deepsea divers who have decompression-induced venous bubbles do not demonstrate neurological symptoms at these high rates. This apparent disparity may be attributable to the normal pressure gradient across the atria of the heart that must be reversed for there to be flow potency. We evaluated the effects of: venous gas embolism (0.025, 0.05 and 0.15 ml/ kg min for 180 min.) hyperbaric decompression; and hypobaric decompression on the pressure gradient across the left and right atria in anesthetized dogs with intact atrial septa. Left ventricular end-diastolic pressure was used as a measure of left atrial pressure. In a total of 92 experimental evaluations in 22 dogs, there were no reported reversals in the mean pressure gradient across the atria; a total of 3 transient reversals occurred during the peak pressure gradient changes. The reasons that decompression-induced venous bubbles do not consistently cause serious symptoms of decompression illness may be that the amount of venous gas does not always cause sufficient pressure reversal across a patent foramen ovale to cause arterialization of the venous bubbles.

  16. Decompression schedule optimization with an isoprobabilistic risk of decompression sickness.

    PubMed

    Horn, Beverley J; Wake, Graeme C; Anthony, T Gavin

    2006-01-01

    Divers use decompression schedules to reduce the probability of occurrence of decompression sickness when returning to the surface at the end of a dive. The probability of decompression sickness resulting from these schedules varies across different dives and the models used to generate them. Usually the diver is unaware of this variance in risk. This paper describes an investigation into the feasibility of producing optimized iso-probabilistic decompression schedules that minimize the time it takes for a diver to reach the surface. The decompression schedules were optimized using the sequential quadratic programming method (SQP), which minimizes the ascent time for a given probability of decompression sickness. The U.S. linear-exponential multi-gas model was used to calculate an estimate of the probability of decompression sickness for a given dive. In particular 1.3-bar oxygen in helium rebreather bounce dives to between 18 m and 81 m were considered and compared against the UK Navy QinetiQ 90 tables for a similar estimate of probability of decompression sickness. The SQP method reliably produced schedules with fast and stable convergence to an optimized solution. Comparison of the optimized decompression schedules with the QinetiQ 90 schedules showed similar stop times for shallow dives to 18 m. For dives with a maximum depth of 39 m to 81 m, optimizing the decompression resulted in savings in decompression time of up to 30 min. This paper has shown that it is feasible to produce optimized iso-probabilistic decompression tables given a reliable risk model for decompression sickness and appropriate dive trials.

  17. Decompressive laparotomy for abdominal compartment syndrome

    PubMed Central

    Kimball, E.; Malbrain, M.; Nesbitt, I.; Cohen, J.; Kaloiani, V.; Ivatury, R.; Mone, M.; Debergh, D.; Björck, M.

    2016-01-01

    Background The effect of decompressive laparotomy on outcomes in patients with abdominal compartment syndrome has been poorly investigated. The aim of this prospective cohort study was to describe the effect of decompressive laparotomy for abdominal compartment syndrome on organ function and outcomes. Methods This was a prospective cohort study in adult patients who underwent decompressive laparotomy for abdominal compartment syndrome. The primary endpoints were 28‐day and 1‐year all‐cause mortality. Changes in intra‐abdominal pressure (IAP) and organ function, and laparotomy‐related morbidity were secondary endpoints. Results Thirty‐three patients were included in the study (20 men). Twenty‐seven patients were surgical admissions treated for abdominal conditions. The median (i.q.r.) Acute Physiology And Chronic Health Evaluation (APACHE) II score was 26 (20–32). Median IAP was 23 (21–27) mmHg before decompressive laparotomy, decreasing to 12 (9–15), 13 (8–17), 12 (9–15) and 12 (9–14) mmHg after 2, 6, 24 and 72 h. Decompressive laparotomy significantly improved oxygenation and urinary output. Survivors showed improvement in organ function scores, but non‐survivors did not. Fourteen complications related to the procedure developed in eight of the 33 patients. The abdomen could be closed primarily in 18 patients. The overall 28‐day mortality rate was 36 per cent (12 of 33), which increased to 55 per cent (18 patients) at 1 year. Non‐survivors were no different from survivors, except that they tended to be older and on mechanical ventilation. Conclusion Decompressive laparotomy reduced IAP and had an immediate effect on organ function. It should be considered in patients with abdominal compartment syndrome. PMID:26891380

  18. Diving behaviour and decompression sickness among Galapagos underwater harvesters.

    PubMed

    Westin, A A; Asvall, J; Idrovo, G; Denoble, P; Brubakk, A O

    2005-01-01

    Diving conditions, dive profiles, vascular bubbles, and symptoms of decompression sickness (DCS) in a group of Galapagos commercial divers are described. They harvest sea cucumbers from small boats with surface supplied air (hookah). Dive profiles for 12 divers were recorded using dive loggers, and bubble formation was measured in the pulmonary artery. DCS symptoms were assessed by interview. A total of 380 immersions were recorded over a nine day period. The divers did on average 6.3 immersions per day, in a yo-yo pattern. Mean overall depth was 34.5 FSW. Maximum recorded depth was 107 FSW. Average bottom time per day per diver was 175 minutes. 82 % of all ascents exceeded the recommended maximum ascent rate of 30 FSW/ min. High bubble grades were observed on six occasions, but the test was unreliable. Muscle and joint pain was reported on five occasions, in three different divers. Symptoms were typically managed by analgesics, in-water recompression or not at all. The divers were extremely reluctant to seek professional help for DCS symptoms, mostly due to the high costs of treatment. We conclude that the fishermen dive beyond standard no-decompression limits, and that DCS symptoms are common.

  19. Fast Compression and Decompression capabilities at HPCAT, APS

    NASA Astrophysics Data System (ADS)

    Sinogeikin, S. V.

    2016-12-01

    Materials behavior and phase transformation pathways are strongly influenced by the time dependence of the driving mechanism (compression, thermal transfer, strain, irradiation, etc). While shock compression and static compression are well established techniques available for a long time, the techniques filling the compression rate gap and studying materials behavior as a function of compression rates at intermediate rates remain scarce. Recent advances in synchrotron sources, x-ray optics, fast area detectors, and sample environment control have enabled many time-resolved experimental techniques for studying materials at extreme pressure and temperature conditions. The High Pressure Collaborative Access Team (HPCAT) at the Advanced Photon Source has made a sustained effort to develop and assemble a powerful collection of high-pressure apparatus for time-resolved research and developing techniques for collecting high-quality time-resolved x-ray scattering data at compression rates intermediate between static and shock compression experiments. In this talk we will outline recently developed capabilities at HPCAT for synthesis of metastable and amorphous materials and studying properties (EOS, lattice relaxation, etc.) and phase transition mechanisms of materials using fast unidirectional and cyclic compression-decompression with variable strain rates up to extreme compression of tens of TPa per second.

  20. Decompression sickness in caisson workers

    PubMed Central

    Ghawabi, Samir H. El; Mansour, Mohamed B.; Youssef, Fatma L.; Ghawabi, Mohamed H. El; Latif, Mohamed M. Abd El

    1971-01-01

    El Ghawabi, S. H., Mansour, M. B., Youssef, F. L., El Ghawabi, M. H., and Abd El Latif, M. M. (1971).Brit. J. industr. Med.,28, 323-329. Decompression sickness in caisson workers. An investigation of 55 bridge construction workers is reported. The overall bends rate was 0·97%. (The term `bends' as used in this study is defined in the paper.) Chokes were encountered in 67·27% of workers. A clinical, haematological, and radiological study was performed. Definite bony changes were found in 43·6% of all workers; 91·6% of these had lesions around the elbow. The presence of dense areas in the neck of the scapula is reported in two cases for the first time. The relatively high haematocrit value is thought to play a part in the pathogenesis of bone infarction through its relation with blood viscosity. Images PMID:5124832

  1. Extreme Lightning Flash Rates as an Early Indicator of Severe Storms

    NASA Technical Reports Server (NTRS)

    Goodman, Steven J.; Arnold, James E. (Technical Monitor)

    2002-01-01

    Extreme lightning flash rates are proving to be an early indicator of intensifying storms capable of producing tornadoes, damaging winds and hail. Most of this lightning is in the cloud, where the naked eye can not see it. Recent global observations of thunderstorms from space indicate that giant electrical storms (supercells and convective complexes) with flash rates on the order of 1 flash per second are most common over the land masses of the America sub-tropics and equatorial Congo Basin. Within the United States, the average tornado warning lead time on a national basis is about 11 min. The real-time observation of extreme flash rates and the rapid increase in the in-cloud flash rate, signalling the intensification of the storm updraft, may provide as much as a 50% increase in severe storm warning lead time.

  2. The washout rate of a subcutaneous 99mTc-HSA depot in lower extremity lymphoedema.

    PubMed

    Jensen, Mads R; Simonsen, Lene; Karlsmark, Tonny; Bülow, Jens

    2012-03-01

    Lymphoscintigraphy is currently the leading diagnostic modality of lower extremity lymphoedema but has been criticized for being unreliable. Washout rate constants have been investigated and proven to be of diagnostic value in several studies of breast-cancer-related lymphoedema; however, the applicability in lower extremity lymphoedema needs further evaluation. The aim of the study was to verify if washout of (99m) Tc-human serum albumin ((99m) Tc-HSA) is a reliable diagnostic tool in lower extremity lymphoedema. Twenty healthy volunteers and eight patients (11 legs) with lymphoscintigraphy verified lower extremity lymphoedema participated in the study. A depot consisting of 0.1 ml 10 MBq/ml (99m) Tc-HSA was injected subcutaneously into the dorsum of each foot. The depot washout rate was measured using a portable scintillation detector system and time-activity curves were generated. After 30 min of supine rest and 10 min of standardized ergometric exercise, measurements were recorded for 20 min. Following correction for physical decay of (99m) Tc, the depot washout rate constant was calculated using linear regression analysis. Finally depot half-life was calculated from the washout rate constant. Median half-life for healthy volunteers was 9.4 h (range 2.5-28.3 h). Median half-life for lymphoedema patients was 10.7 h (range 1.5-35.1 h). No statistical significant difference could be detected between healthy volunteers and lymphoedema patients (P = 0.78). The washout rate of a subcutaneous (99m) Tc-HSA depot is not a reliable diagnostic tool in examination of lower extremity lymphoedema. Additional examinations revealed in vivo instability of the utilized (99m) Tc-HSA as the likely reason. © 2011 The Authors. Clinical Physiology and Functional Imaging © 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

  3. [The use of cell cultures for in vitro decompression sickness simulation].

    PubMed

    Palkovic, M; Novomeský, F; Zaviacic, M; Danihel, L; Kovác, P; Danisovic, L

    2007-01-01

    Recreational and technical diving in the past twenty years have become extraordinary popular. Until then diving was a priority of police, army and scientists. Today more and more enthusiasts are exposed to abnormally high surrounding pressure. To the severest of all risks associated with diving, decompression sickness is the greatest threat. Even the most advanced scientific approaches yet did not reveal the complex mechanisms of decompression sickness formation. The majority of experiments use a live model for decompression sickness studies. This is associated with high fatality rate. The new approach of this scientific study is in the use of an in vitro working media as a means of visualization of gas bubbles due to decompression. The aim of this study is to bring above new approaches in in vitro gas bubble formation during decompression. Main goals are: development of in vitro inert gas bubble visualization and evaluation techniques after a real decompression dive with air a as the diving gas and EANx50 as a decompression gas. We selected cell cultures derived from human fibroblasts B-HEF-2 and cell cultures of mice N2A neuroblasts. We used two decompression profiles. "Explosive" decompression profile with a linear compression to overpressure of 50 bar with an rapid decompression to atmospheric pressure (1 bar). In simulation of a realistic decompression profile we used compressed air as a mean for compression and isocompression breathing gas and an EANx50 blend as a decompression breathing gas. This dive was planned with the use of a VPM-B decompression profile by V-Planner software v.3.62. Our latest experiments show that DNA fragmentation and apoptosis is activated during decompression shock. Use of culture cells can be of great value in further studies of decompression changes in the cellular and subcellular level.

  4. The incidences of and consultation rate for lower extremity complaints in general practice

    PubMed Central

    van der Waal, J M; Bot, S D M; Terwee, C B; van der Windt, D A W M; Schellevis, F G; Bouter, L M; Dekker, J

    2006-01-01

    Objective To estimate the incidence and consultation rate of lower extremity complaints in general practice. Methods Data were obtained from the Second Dutch National Survey of General Practice, in which 195 general practitioners (GPs) in 104 practices recorded all contacts with patients during 12 consecutive months in computerised patient records. GPs classified the symptoms and diagnosis for each patient at each consultation according to the International Classification of Primary Care (ICPC). Incidence densities and consultation rates for different complaints were calculated. Results During the registration period 63.2 GP consultations per 1000 person‐years were attributable to a new complaint of the lower extremities. Highest incidence densities were seen for knee complaints: 21.4 per 1000 person‐years for women and 22.8 per 1000 person‐years for men. The incidence of most lower extremity complaints was higher for women than for men and higher in older age. Conclusions Both incidences of and consultation rates for lower extremity complaints are substantial in general practice. This implies a considerable impact on the workload of the GP. PMID:16269430

  5. THE AMELIORATIVE EFFECTS OF HEPARIN AND DEPOLYMERIZED HYALURONATE ON DECOMPRESSION SICKNESS IN RATS,

    DTIC Science & Technology

    DECOMPRESSION SICKNESS, DRUGS), (* MUCOPOLYSACCHARIDES , DECOMPRESSION SICKNESS), (*HEPARIN, DECOMPRESSION SICKNESS), (*ANTICOAGULANTS, DECOMPRESSION SICKNESS), RATS, COUMARINS, BLOOD COAGULATION, DOSAGE, LIPIDS, CANADA

  6. Cardiac Pressure Changes with Venous Gas Embolism and Decompression

    DTIC Science & Technology

    1994-04-01

    bubbles can become arterialized and cause neu- rological decompression illness. Incidence rates of patent foramen ovale in the general populatifn range... patent foramen ovale bubbles 16. MICE CODE dcoe= ression decompression symptoms 17. SECURi• CLASSUICATION 1i. SECURITY C.ASSFICATION 19. SECURITY...septal defects (2,3,41,42,62,66). An atrial meptal defect (ASD), often manifest as a patent foramen ovals (P7O) located between the atria of the heart, may

  7. Mouse heart rate in a human: diagnostic mystery of an extreme tachyarrhythmia.

    PubMed

    Chhabra, Lovely; Goel, Narender; Prajapat, Laxman; Spodick, David H; Goyal, Sanjeev

    2012-01-01

    We report telemetry recording of an extreme non-fatal tachyarrhythmia noted in a hospitalized quadriplegic male with history of atrial fibrillation where the average ventricular conduction rate was found to be about 600 beats per minute and was associated with transient syncope. A medical literature review suggests that the fastest human ventricular conduction rate reported to date in a tachyarrhythmia is 480 beats per minute. We therefore report the fastest human heart rate noted in a tachyarrhythmia and the most probable mechanism of this arrhythmia being a rapid atrial fibrillation with 1:1 conduction in the setting of probable co-existing multiple bypass tracts.

  8. Decompression apparatus for engines

    SciTech Connect

    Harada, M.

    1987-09-29

    In a decompression apparatus for an engine having a camshaft, a cam gear is described having a longitudinal bore along a central axis thereof, and a tappet engaging with an actuating cam on the camshaft. The improvement comprises: a releasing lever comprising a shaft and a weight secured to the shaft; the shaft forming a semicircular cam at one end; the camshaft having a first recess in a longitudinal direction; the cam gear having a second recess adjacent the bore; a bearing member for engaging with the first and second recesses and for rotatably supporting the shaft; a flat bottom notch for supporting the semicircular cam and being provided on the camshaft lose to the actuating cam; and the semicircular cam being arranged to project beyond a periphery of the actuating cam when engine operation is stopped.

  9. Soccer-Specific Warm-Up and Lower Extremity Injury Rates in Collegiate Male Soccer Players

    PubMed Central

    Grooms, Dustin R.; Palmer, Thomas; Onate, James A.; Myer, Gregory D.; Grindstaff, Terry

    2013-01-01

    Context: A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population. Objective: To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players. Design: Cohort study. Setting: One American collegiate soccer team followed for 2 seasons. Patients or Other Participants: Forty-one male collegiate athletes aged 18–25 years. Intervention(s): The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer. Main Outcome Measure(s): Lower extremity injury risk and time lost to lower extremity injury. Results: The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01). Conclusions: This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer

  10. Core decompression for juvenile osteonecrosis.

    PubMed

    Herrera-Soto, José A; Price, Charles T

    2011-07-01

    Core decompression may be used as adjunct for treatment in some cases of Legg-Calvé-Perthes disease (LCPD). The primary application is for patients with onset at 12 years of age or older. We recommend classifying these older patients as idiopathic juvenile osteonecrosis and treating them similarly to adults with avascular necrosis. Juvenile osteonecrosis may benefit from core decompression combined with shelf acetabuloplasty during the early stages of necrosis. Younger children with LCPD may benefit from decompression by fenestration of the femoral head. Experience in adult-onset osteonecrosis and our early experience suggest that some patients may benefit from these adjunctive treatments. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Reconciling extreme branch length differences: decoupling time and rate through the evolutionary history of filmy ferns.

    PubMed

    Schuettpelz, Eric; Pryer, Kathleen M

    2006-06-01

    The rate of molecular evolution is not constant across the Tree of Life. Characterizing rate discrepancies and evaluating the relative roles of time and rate along branches through the past are both critical to a full understanding of evolutionary history. In this study, we explore the interactions of time and rate in filmy ferns (Hymenophyllaceae), a lineage with extreme branch length differences between the two major clades. We test for the presence of significant rate discrepancies within and between these clades, and we separate time and rate across the filmy fern phylogeny to simultaneously yield an evolutionary time scale of filmy fern diversification and reconstructions of ancestral rates of molecular evolution. Our results indicate that the branch length disparity observed between the major lineages of filmy ferns is indeed due to a significant difference in molecular evolutionary rate. The estimation of divergence times reveals that the timing of crown group diversification was not concurrent for the two lineages, and the reconstruction of ancestral rates of molecular evolution points to a substantial rate deceleration in one of the clades. Further analysis suggests that this may be due to a genome-wide deceleration in the rate of nucleotide substitution.

  12. A study of lower extremity amputation rates in older diabetic South Carolinians.

    PubMed

    Gonsalves, Wanda C; Gessey, Mark E; Mainous, Arch G; Tilley, Barbara C

    2007-02-01

    Several studies have shown that lower extremity non-traumatic amputations for diabetic patients disproportionately affect senior minorities. Our study uses population and Medicare data from the year 2000 to profile the magnitude of this disparity by county in South Carolina and its relation to race, gender, per capita income, and the number of primary care physicians. Data from 1998-2001 is used to investigate trends in amputation rates for the state as a whole and for individual counties. Lower extremity non-traumatic amputation (LEA) rates in black diabetic Medicare patients are more than twice that of White diabetic Medicare patients. In 2000, the three counties with the highest LEA rates for black males were Barnwell (5.06%), Allendale (4.87%), and Florence (4.50%). LEA rates are not related to the number of primary care physicians per 10,000 county residents or per capita income. All gender/race groups saw declines in LEA rates. Although our study could not explain the socioeconomic factors involved, it does mirror other prior studies that show a racial disparity in LEAs. Similarly, men have a greater risk of diabetic non-traumatic LEAs. Interestingly however, having more primary care physicians per 10,000 county residents does not decrease the rate of amputations. Policy makers and insurance brokers may utilize our findings to target the areas of most need for intervention and further studies. Improved adherence to guidelines by primary care physicians, decreasing barriers to health care access, educating patients about the severity of diabetes and its complications, and providing more culturally competent care may lessen the burden of this disability for our minority patients. In the era of "pay for performance", the rate of LEAs as a proxy of poor diabetic care management must clearly improve. Fortunately, the decrease in LEA rates over time as shown in our study is a step in the right direction. However, the decrease is not consistent across all counties

  13. Piezosurgery in modified pterional orbital decompression surgery in Graves' disease.

    PubMed

    Grauvogel, Juergen; Scheiwe, Christian; Masalha, Waseem; Jarc, Nadja; Grauvogel, Tanja; Beringer, Andreas

    2017-07-10

    Piezosurgery utilizes microvibrations to selectively cut bone, preserving the adjacent soft tissue. The present study evaluated the use of piezosurgery for bone removal in orbital decompression surgery in Graves' disease via a modified pterional approach. A piezosurgical device (Piezosurgery medical®) was used in 14 patients (20 orbits) with Graves' disease who underwent orbital decompression surgery in additional to drills and rongeurs for bone removal of the lateral orbital wall and orbital roof. The practicability, benefits and drawbacks of this technique in orbital decompression surgery were recorded. Piezosurgery was evaluated with respect to safety, preciseness of bone cutting, and preservation of the adjacent dura and periorbita. Pre- and postoperative clinical outcome data were assessed. The orbital decompression surgery was successful in all 20 orbits, with good clinical outcomes and no postoperative complications. Piezosurgery proved to be a safe tool allowing selective bone cutting with no damage to the surrounding soft tissue structures. However, there were disadvantages concerning the intraoperative handling in the narrow space and the efficiency of bone removal was limited in the orbital decompression surgery in comparison to drills. Piezosurgery proved to be a useful tool in bone removal for orbital decompression in Graves' disease. It is safe and easy to perform without any danger of damage to adjacent tissue due to its selective bone cutting properties. Nonetheless, further development of the device is necessary to overcome the disadvantages in intraoperative handling and the reduced bone removal rate. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Mixed-gas model for predicting decompression sickness in rats.

    PubMed

    Lillo, R S; Parker, E C

    2000-12-01

    A mixed-gas model for rats was developed to further explore the role of different gases in decompression and to provide a global model for possible future evaluation of its usefulness for human prediction. A Hill-equation dose-response model was fitted to over 5,000 rat dives by using the technique of maximum likelihood. These dives used various mixtures of He, N(2), Ar, and O(2) and had times at depth up to 2 h and varied decompression profiles. Results supported past findings, including 1) differences among the gases in decompression risk (He < N(2) < Ar) and exchange rate (He > Ar approximately N(2)), 2) significant decompression risk of O(2), and 3) increased risk of decompression sickness with heavier animals. New findings included asymmetrical gas exchange with gas washout often unexpectedly faster than uptake. Model success was demonstrated by the relatively small errors (and their random scatter) between model predictions and actual incidences. This mixed-gas model for prediction of decompression sickness in rats is the first such model for any animal species that covers such a broad range of gas mixtures and dive profiles.

  15. Extreme stress gradient effects on microstructural fatigue crack propagation rates in Ni microbeams

    SciTech Connect

    Sadeghi-Tohidi, F.; Pierron, O. N.

    2015-05-18

    The fatigue crack propagation behavior of microstructurally small cracks growing under extreme stress gradients was investigated in Ni microbeams under fully reversed cyclic loading. A technique to calculate the crack growth rates in microbeams with two different normalized stress gradients (17% and 50% μm{sup −1}) is developed and validated. Decreasing crack propagation rates are observed over the first 2 μm, and the rates are more than 1 order of magnitude slower for the devices with 50% μm{sup −1} stress gradients. This fundamental knowledge is critical to predict the fatigue reliability of advanced metallic microcomponents under bending such as in microelectromechanical systems or flexible/stretchable electronics.

  16. Degassing of H2O in a phonolitic melt: A closer look at decompression experiments

    NASA Astrophysics Data System (ADS)

    Marxer, Holger; Bellucci, Philipp; Nowak, Marcus

    2015-05-01

    Melt degassing during magma ascent is controlled by the decompression rate and can be simulated in decompression experiments. H2O-bearing phonolitic melts were decompressed at a super-liquidus T of 1323 K in an internally heated argon pressure vessel, applying continuous decompression (CD) as well as to date commonly used step-wise decompression (SD) techniques to investigate the effect of decompression method on melt degassing. The hydrous melts were decompressed from 200 MPa at nominal decompression rates of 0.0028-1.7 MPa·s- 1. At final pressure (Pfinal), the samples were quenched rapidly at isobaric conditions with ~ 150 K·s- 1. The bubbles in the quenched samples are often deformed and dented. Flow textures in the glass indicate melt transport at high viscosity. We suggest that this observation is due to bubble shrinkage during quench. This general problem was mostly overlooked in the interpretation of experimentally degassed samples to date. Bubble shrinkage due to decreasing molar volume (Vm) of the exsolved H2O in the bubbles occurs during isobaric rapid quench until the melt is too viscous too relax. The decrease of Vm(H2O) during cooling at Pfinal of the experiments results in a decrease of the bubble volume by a shrinking factor Bs: At nominal decompression rates > 0.17 MPa·s- 1 and a Pfinal of 75 MPa, the decompression method has only minor influence on melt degassing. SD and CD result in high bubble number densities of 104-105 mm- 3. Fast P drop leads to immediate supersaturation with H2O in the melt. At such high nominal decompression rates, the diffusional transport of H2O is limited and therefore bubble nucleation is the predominant degassing process. The residual H2O contents in the melts decompressed to 75 MPa increase with nominal decompression rate. After homogeneous nucleation is triggered, CD rates ≤ 0.024 MPa·s- 1 facilitate continuous reduction of the supersaturation by H2O diffusion into previously nucleated bubbles. Bubble number

  17. Multifractal comparison of the extremes of rain rates and integrated vapour content

    NASA Astrophysics Data System (ADS)

    Gires, Auguste; Ni, Vincent; Bosser, Pierre; Tchiguirinskaia, Ioulia; Schertzer, Daniel

    2015-04-01

    Rainfall extremes are studied through the analyse of three related fields measured with the help of co-located devices installed in the roof of the Ecole des Ponts ParisTech building: (i) Integrated Water Vapour (IWV); it corresponds the amount of water vapour present in the vertical columns between a GPS ground receiver and corresponding satellites. It is estimated from the time shift between the expected duration the signal needs to reach the receiver (the two positions are known) and the actual one (ii) Rain rate measured by three optical disdrometers of two different types (Campbell Scientific PWS100 and OTT Parsivel2) (iii) Relative humidity measured by a dedicated sensor First the correlations between these quantities during significant events is analysed. It appears that although IWV tends to decrease (vapour condense to form drops that fall) and relative humidity to increase during a rainfall event, it turns out difficult to quantitatively characterize this link. It is possibly due to the fact that the scale gap between a punctual measure for the rain rate and an average over a few km height column for the IWV is too large. Finally the scaling features of these three fields are investigated with the help of the Universal Multifractal framework which has been extensively used to analyse and simulate geophysical fields extremely variable over wide ranges of scales. Only three parameters are used to characterize variability across scales: C1 the mean intermittency, alpha the multifractality index and H the non-conservative exponent. Retrieved features are compared and the notion of maximum observable singularity is used to quantify the extremes of the various fields. Authors acknowledge the financial support of the Interreg IV NEW RainGain project (www.raingain.eu) and the chair "hydrology for resilient cities" sponsored by Véolia, and the Climate-KIC Blue Green Dream project (bgd.org.uk/).

  18. Event Rate for Extreme Mass Ratio Burst Signals in the Laser Interferometer Space Antenna Band

    NASA Astrophysics Data System (ADS)

    Rubbo, Louis J.; Holley-Bockelmann, Kelly; Finn, Lee Samuel

    2006-09-01

    Stellar mass compact objects in short-period (P<~103 s) orbits about a 104.5-107.5 Msolar massive black hole (MBH) are thought to be a significant continuous-wave source of gravitational radiation for the ESA/NASA Laser Interferometer Space Antenna (LISA) gravitational wave detector. These extreme mass ratio inspiral sources began in long-period, nearly parabolic orbits that have multiple close encounters with the MBH. The gravitational radiation emitted during the close encounters may be detectable by LISA as a gravitational wave burst if the characteristic passage timescale is less than 105 s. Scaling a static, spherical model to the size and mass of the Milky Way bulge, we estimate an event rate of ~15 yr-1 for such burst signals, detectable by LISA with signal-to-noise ratio greater than 5, originating in our Galaxy. When extended to include Virgo Cluster galaxies, our estimate increases to a gravitational wave burst rate of ~18 yr-1. We conclude that these extreme mass ratio burst sources may be a steady and significant source of gravitational radiation in the LISA data streams.

  19. Early Decompression (< 8 h) after Traumatic Cervical Spinal Cord Injury Improves Functional Outcome as Assessed by Spinal Cord Independence Measure after One Year.

    PubMed

    Grassner, Lukas; Wutte, Christof; Klein, Barbara; Mach, Orpheus; Riesner, Silvie; Panzer, Stephanie; Vogel, Matthias; Bühren, Volker; Strowitzki, Martin; Vastmans, Jan; Maier, Doris

    2016-09-15

    There is an ongoing controversy about the optimal timing for surgical decompression after acute traumatic cervical spinal cord injury (SCI). For this reason, we performed a retrospective study of patients who were operated on after traumatic cervical SCI at the Trauma Center Murnau, Germany, and who met inclusion as well as exclusion criteria (n = 70 patients). Follow-up data were collected prospectively according to the European Multicenter Study about Spinal Cord Injury (EMSCI) protocol over a period of 1 year. Early decompression was defined as within the first 8 h after the insult (n = 35 patients). Primary outcome was the difference in the SCIM (Spinal Cord Independence Measure) 1 year after the trauma. After the follow-up period, patients who were decompressed earlier had a significantly higher SCIM difference (45.8 vs. 27.1, p < 0.005). A regression analysis showed that timing of decompression, age, as well as basal AIS (American Spinal Injury Association Impairment Scale) and basal SCIM scores were independent predictors for a better functional outcome (SCIM). Further, patients from the early decompression group had better AIS grades (p < 0.006) and a higher AIS conversion rate (p < 0.029). Additionally, this cohort also had a better total motor performance as well as upper extremity motor function after 1 year (p < 0.025 and p < 0.002). The motor and neurological levels of patients who were operated on within 8 h were significantly more caudal (p < 0.003 and p < 0.014) after 1 year. The present study suggests that early decompression after traumatic cervical SCI might have a positive impact on the functional and neurological outcome of affected individuals.

  20. Dynamic Heating and Decompression Experiments on Dacite and Rhyolite Magmas

    NASA Astrophysics Data System (ADS)

    Andrews, B. J.; Waters, L.; Grocke, S. B.

    2015-12-01

    Mineral reaction rims, zoned crystals, and myriad growth or dissolution textures provide evidence for changes in magma pressure, temperature, or composition. Quantifying the magnitudes, timescales and length scales of those variations is a fundamental challenge of volcanology and igneous petrology; experiments provide quantitative insights into how magmas react to changes in pressure and temperature that can be used to address that challenge. We use single-step and dynamic experiments conducted in cold seal pressure vessels to study the responses of dacite and rhyolite magmas to heating and decompression events. During single-step decompression (or heating) experiments, conditions are changed nearly instantaneously from the initial to final state in one step, or several smaller steps, whereas "dynamic experiments" have continuous variation in pressure and/or temperature. These two types of experiments yield useful and complementary information describing crystal nucleation, growth, and reaction rates in response to changing (as opposed to steady state) conditions. Here we discuss isothermal decompression experiments that show substantial path-dependence for runs with equivalent time-averaged decompression rates as slow as 0.27 MPa/h for >500 h. Continuous decompression experiments often contain fewer but larger plagioclase crystals than are present in single-step runs, and those new crystals often show complex growth textures. Our results suggest that even slow changes in storage conditions can disrupt melt structure and greatly retard nucleation provided the changes are steady. We hypothesize that if the decompression path remains steady and continuous (absent a stall on and/or rapid decompression), the magma can remain in a growth-dominated regime even though it is far from equilibrium.

  1. Revision Rate and Risk Factors After Lower Extremity Amputation in Diabetic or Dysvascular Patients.

    PubMed

    Wanivenhaus, Florian; Mauler, Flavien; Stelzer, Teresa; Tschopp, Alois; Böni, Thomas; Berli, Martin C

    2016-01-01

    This article reports the revision rate and possible risk factors for lower extremity amputations in patients with diabetes mellitus or peripheral arterial disease (PAD). Data were collected from 421 patients with diabetes mellitus or PAD who underwent amputations of the lower extremity at the authors' institution from 2002 to 2012. There was a 25.2% overall revision rate. Mean time from amputation to revision was 244 days (range, 2-2590 days). Patients with diabetes mellitus had a significantly higher rate of revision to a more proximal level compared with patients without diabetes mellitus (type 1: odds ratio [OR]=3.73; 95% confidence interval [CI], 1.21-11.52; P=.022; and type 2: OR=2.3; 95% CI, 1.07-4.95; P=.033). A significant increase in revision rates was observed from Fontaine stage 0 to IV (stage 0: 17.9%; stage IV, 34.7%; P=.03). Risk factors for revision were diabetic nephropathy (OR=2.26; 95% CI, 1.4-3.63; P=.001) and polyneuropathy (OR=1.68; 95% CI, 1.03-2.73; P=.037). Patients who underwent revision amputation had a significantly younger mean age than patients who did not undergo revision amputation (65.23 years [range, 40-92 years] vs 68.52 years [range, 32-96 years]; P=.013). Anticipated amputation in this patient population requires a multidisciplinary approach with optimization of the patient's health. In the authors' clinical practice, the determination of the appropriate amputation level is performed individually for each patient, considering the risk factors identified in this study and the patient's expected mobilization potential, social background, and acceptance of a more proximal primary amputation level.

  2. A retrospective analysis of amputation rates in diabetic patients: can lower extremity amputations be further prevented?

    PubMed Central

    2012-01-01

    Background Lower extremity amputations are costly and debilitating complications in patients with diabetes mellitus (DM). Our aim was to investigate changes in the amputation rate in patients with DM at the Karolinska University Hospital in Solna (KS) following the introduction of consensus guidelines for treatment and prevention of diabetic foot complications, and to identify risk groups of lower extremity amputations that should be targeted for preventive treatment. Methods 150 diabetic and 191 nondiabetic patients were amputated at KS between 2000 and 2006; of these 102 diabetic and 99 nondiabetic patients belonged to the catchment area of KS. 21 diabetic patients who belonged to KS catchment area were amputated at Danderyd University Hospital. All patients' case reports were searched for diagnoses of diabetes, vascular disorders, kidney disorders, and ulcer infections of the foot. Results There was a 60% reduction in the rate of amputations performed above the ankle in patients with DM during the study period. Patients with DM who underwent amputations were more commonly affected by foot infections and kidney disorders compared to the nondiabetic control group. Women with DM were 10 years older than the men when amputated, whereas men with DM underwent more multiple amputations and had more foot infections compared to the women. 88% of all diabetes-related amputations were preceded by foot ulcers. Only 30% of the patients had been referred to the multidisciplinary foot team prior to the decision of amputation. Conclusions These findings indicate a reduced rate of major amputations in diabetic patients, which suggests an implementation of the consensus guidelines of foot care. We also propose further reduced amputation rates if patients with an increased risk of future amputation (i.e. male sex, kidney disease) are identified and offered preventive treatment early. PMID:22385577

  3. Irrigation endoscopic decompressive laminotomy. A new endoscopic approach for spinal stenosis decompression.

    PubMed

    Soliman, Hesham Magdi

    2015-10-01

    The classic surgical treatment of spinal stenosis involves bilateral dissection of paraspinal muscles to expose all the involved levels, wide laminectomy, and medial facetectomy and foraminotomy. The surgical morbidity of the procedure is further magnified by being more common in elderly with associated medical comorbidities and being usually global involving multiple levels. To address this problem, several less invasive techniques have been introduced over the past decade including the microendoscopic decompression. The aim was to describe and evaluate a new endoscopic technique for lumbar spinal canal decompression named irrigation endoscopic decompressive laminotomy. This was a technical report. One hundred four consecutive patients suffering from neurogenic claudication and resistant to 3 months of conservative management were included in the study. Grade I degenerative spondylolisthesis and degenerative scoliosis were not considered a contraindication. Patients with segmental instability and predominant low back pain were excluded. Primary outcome measures included the final functional outcome using modified Macnab criteria and the Oswestry Disability Index (ODI). In addition, the operative time and complication rate have been evaluated. Secondary outcome measures included the evaluation of the early postoperative course using visual analog scale for postoperative incisional pain, time for ambulation, and length of hospital stay. Two 0.5-cm portals were used, one for the endoscope and the other for instruments. For every additional level, one portal is added. The endoscope and instruments are directly placed over the surface of lamina without any dissection, and saline under pump pressure is used to open a potential working space. Unilateral laminotomy/laminectomy is performed according to the severity of stenosis, followed by bilateral decompression beneath the midline structures. Mean follow-up period was 28 months. The final outcome was excellent in 63

  4. Osteoplastic decompressive craniotomy--an alternative to decompressive craniectomy.

    PubMed

    Mracek, Jan; Choc, Milan; Mork, Jan; Vacek, Petr; Mracek, Zdenek

    2011-11-01

    In spite of various degrees of brain expansion, decompressive surgery is usually carried out using decompressive craniectomy (DC). After craniectomy it is necessary to perform cranioplasty, which prolongs hospitalization and is not always without complications. Hence, in situations when cranial decompression is indicated, but DC would be too radical, we do not remove the bone flap, and we perform so-called osteoplastic decompressive craniotomy (ODC). The technique is detailed. To demonstrate the effectiveness of ODC. Twenty patients underwent ODC for brain edema under various pathological conditions. The diagnoses were as follows: 13 subdural hematomas, 3 cerebral contusions, 2 middle cerebral artery infarcts, 1 epidural hematoma and 1 arteriovenous malformation. The effect of ODC was assessed using postoperative ICP monitoring and the midline shift on CT. The ICP threshold for the additional removal of the bone flap was 25 mmHg. Clinical outcome was evaluated 6 months after surgery using the Glasgow Outcome Scale (GOS). Postoperative ICP was up to 25 mmHg in 18 patients and exceeded 25 mmHg in 2 cases. The mean midline shift on CT was 10 mm preoperatively and 3 mm postoperatively. The decompression during ODC was sufficient in 18 patients and insufficient in 2 in whom an additional removal of the bone flap was performed. Eight survivals had a favorable outcome (GOS 4-5); 12 patients had an unfavorable outcome (GOS 1-3), and of these, 4 died. Our limited study shows that ODC is effective in the treatment of intracranial hypertension in the selected subgroup of patients in whom DC would be too radical. The main advantage of this method is the elimination of further cranioplasty.

  5. Hypobaric Decompression Sickness Treatment Model.

    PubMed

    Conkin, Johnny; Abercromby, Andrew F J; Dervay, Joseph P; Feiveson, Alan H; Gernhardt, Michael L; Norcross, Jason R; Ploutz-Snyder, Robert; Wessel, James H

    2015-06-01

    The Hypobaric Decompression Sickness (DCS) Treatment Model links a decrease in computed bubble volume from increased pressure (ΔP), increased oxygen (O2) partial pressure, and passage of time during treatment to the probability of symptom resolution [P(SR)]. The decrease in offending volume is realized in two stages: 1) during compression via Boyles law; and 2) during subsequent dissolution of the gas phase via the oxygen window. We established an empirical model for the P(SR) while accounting for multiple symptoms within subjects. The data consisted of 154 cases of hypobaric DCS symptoms with ancillary information from tests on 56 men and 18 women. Our best estimated model is P(SR)=1/(1+exp(-(ln(ΔP)-1.510+0.795×AMB-0.00308×Ts)/0.478)), where ΔP is pressure difference (psid); AMB=1 if ambulation took place during part of the altitude exposure, otherwise AMB=0; and Ts is the elapsed time in minutes from the start of altitude exposure to recognition of a DCS symptom. Values of ΔP as inputs to the model would be calculated from the Tissue Bubble Dynamics Model based on the effective treatment pressure: ΔP=P2-P1|=P1×V1/V2-P1, where V1 is the computed volume of a bubble at low pressure P1 and V2 is computed volume after a change to a higher pressure P2. If 100% ground-level oxygen was breathed in place of air, then V2 continues to decrease through time at P2 at a faster rate.

  6. A sequence-specific threading tetra-intercalator with an extremely slow dissociation rate constant.

    PubMed

    Holman, Garen G; Zewail-Foote, Maha; Smith, Amy Rhoden; Johnson, Kenneth A; Iverson, Brent L

    2011-09-25

    A long-lived and sequence-specific ligand-DNA complex would make possible the modulation of biological processes for extended periods. For this purpose, we are investigating a polyintercalation approach to DNA recognition in which flexible chains of aromatic units thread back and forth repeatedly through the double helix. Here we describe the DNA-binding behaviour of a threading tetra-intercalator. Specific binding was observed on a relatively long DNA strand that strongly favoured a predicted 14 base-pair sequence. Kinetic studies revealed a multistep association process, with sequence specificity that primarily derives from large differences in dissociation rates. The rate-limiting dissociation rate constant of the tetra-intercalator complex dissociating from its preferred binding site was extremely slow, corresponding to a half-life of 16 days. This is one of the longest non-covalent complex half-lives yet reported and, to the best of our knowledge, the longest for a DNA-binding molecule.

  7. A sequence-specific threading tetra-intercalator with an extremely slow dissociation rate constant

    NASA Astrophysics Data System (ADS)

    Holman, Garen G.; Zewail-Foote, Maha; Smith, Amy Rhoden; Johnson, Kenneth A.; Iverson, Brent L.

    2011-11-01

    A long-lived and sequence-specific ligand-DNA complex would make possible the modulation of biological processes for extended periods. For this purpose, we are investigating a polyintercalation approach to DNA recognition in which flexible chains of aromatic units thread back and forth repeatedly through the double helix. Here we describe the DNA-binding behaviour of a threading tetra-intercalator. Specific binding was observed on a relatively long DNA strand that strongly favoured a predicted 14 base-pair sequence. Kinetic studies revealed a multistep association process, with sequence specificity that primarily derives from large differences in dissociation rates. The rate-limiting dissociation rate constant of the tetra-intercalator complex dissociating from its preferred binding site was extremely slow, corresponding to a half-life of 16 days. This is one of the longest non-covalent complex half-lives yet reported and, to the best of our knowledge, the longest for a DNA-binding molecule.

  8. Rapid decompression of congenital hydrocephalus associated with parenchymal hemorrhage.

    PubMed

    Bass, T; White, L E; Wood, R D; Werner, A L; Schinco, F P

    1995-10-01

    A newborn boy with congenital hydrocephalus was diagnosed with aqueductal stenosis using magnetic resonance imaging. Low-resistance ventriculoperitoneal shunt placement was followed by clinical deterioration. Repeat imaging studies revealed a collapsed cortical mantle with subdural hemorrhage. In addition to subdural blood, often associated with marked cerebral conformational changes, extensive intraparenchymal hemorrhage was seen. For extreme congenital hydrocephalus, ventriculoperitoneal shunts with greater resistance to flow than the currently used neonatal shunt devices may be indicated, to allow a more gradual ventricular decompression.

  9. Decompressive craniectomy with lattice duraplasty.

    PubMed

    Mitchell, P; Tseng, M; Mendelow, A D

    2004-02-01

    A method of opening dura for decompressive craniectomies is described. Numerous cuts intersecting in a lattice pattern allow the dura to expand in a gradual and controlled manner minimising the chances of cortical laceration or venous kinking on the craniectomy edge.

  10. Decompression sickness during saturation dives.

    PubMed

    Berghage, T E

    1976-12-01

    Available Navy saturation diving data were analyzed for an evaluation of the therapeutic adequacy of decompression sickness treatment procedures and for delineation of precipitant factors in the etiology and treatment of decompression sickness during saturation dives. None of the cases of decompression sickness recorded during saturation dives involved more than musculoskeletal or joint pain, and in 96% of the cases the joint pain was confined to the diver's knees. In 89% of the cases symptoms appeared while the divers were still under pressure. The subsequent recompression treatment of these cases resulted in full relief in only 35% of the cases; the remaining 65% completed the therapy and subsequent decompression with residual pain which diminished over a period of weeks. The adequacy of the recompression appears to be inversely proportional to the depth of reported onset of symptoms and the time required to obtain even partial relief is directly related to the magnitude of the recompression ratio used. Four explanations are suggested for the limited recompression therapy common in saturation diving: increase in musculoskeletal pain with recompression, peer pressure to avoid extension of the chamber confinement, lack of severe neurological symptoms, and the tremendous depths required to obtain a reasonable recompression ratio. The author further suggests that future treatment procedures will require a departure from the accepted concept of radically decreasing the volume of inert gas bubbles by increasing pressure.

  11. Decompression experiments identify kinetic controls on explosive silicic eruptions

    USGS Publications Warehouse

    Mangan, M.T.; Sisson, T.W.; Hankins, W.B.

    2004-01-01

    Eruption intensity is largely controlled by decompression-induced release of water-rich gas dissolved in magma. It is not simply the amount of gas that dictates how forcefully magma is propelled upwards during an eruption, but also the rate of degassing, which is partly a function of the supersaturation pressure (??Pcritical) triggering gas bubble nucleation. High temperature and pressure decompression experiments using rhyolite and dacite melt reveal compositionally-dependent differences in the ??Pcritical of degassing that may explain why rhyolites have fueled some of the most explosive eruptions on record.

  12. Mixture Random-Effect IRT Models for Controlling Extreme Response Style on Rating Scales

    PubMed Central

    Huang, Hung-Yu

    2016-01-01

    Respondents are often requested to provide a response to Likert-type or rating-scale items during the assessment of attitude, interest, and personality to measure a variety of latent traits. Extreme response style (ERS), which is defined as a consistent and systematic tendency of a person to locate on a limited number of available rating-scale options, may distort the test validity. Several latent trait models have been proposed to address ERS, but all these models have limitations. Mixture random-effect item response theory (IRT) models for ERS are developed in this study to simultaneously identify the mixtures of latent classes from different ERS levels and detect the possible differential functioning items that result from different latent mixtures. The model parameters can be recovered fairly well in a series of simulations that use Bayesian estimation with the WinBUGS program. In addition, the model parameters in the developed models can be used to identify items that are likely to elicit ERS. The results show that a long test and large sample can improve the parameter estimation process; the precision of the parameter estimates increases with the number of response options, and the model parameter estimation outperforms the person parameter estimation. Ignoring the mixtures and ERS results in substantial rank-order changes in the target latent trait and a reduced classification accuracy of the response styles. An empirical survey of emotional intelligence in college students is presented to demonstrate the applications and implications of the new models. PMID:27853444

  13. Spatial domain entertainment audio decompression/compression

    NASA Astrophysics Data System (ADS)

    Chan, Y. K.; Tam, Ka Him K.

    2014-02-01

    The ARM7 NEON processor with 128bit SIMD hardware accelerator requires a peak performance of 13.99 Mega Cycles per Second for MP3 stereo entertainment quality decoding. For similar compression bit rate, OGG and AAC is preferred over MP3. The Patent Cooperation Treaty Application dated 28/August/2012 describes an audio decompression scheme producing a sequence of interleaving "min to Max" and "Max to min" rising and falling segments. The number of interior audio samples bound by "min to Max" or "Max to min" can be {0|1|…|N} audio samples. The magnitudes of samples, including the bounding min and Max, are distributed as normalized constants within the 0 and 1 of the bounding magnitudes. The decompressed audio is then a "sequence of static segments" on a frame by frame basis. Some of these frames needed to be post processed to elevate high frequency. The post processing is compression efficiency neutral and the additional decoding complexity is only a small fraction of the overall decoding complexity without the need of extra hardware. Compression efficiency can be speculated as very high as source audio had been decimated and converted to a set of data with only "segment length and corresponding segment magnitude" attributes. The PCT describes how these two attributes are efficiently coded by the PCT innovative coding scheme. The PCT decoding efficiency is obviously very high and decoding latency is basically zero. Both hardware requirement and run time is at least an order of magnitude better than MP3 variants. The side benefit is ultra low power consumption on mobile device. The acid test on how such a simplistic waveform representation can indeed reproduce authentic decompressed quality is benchmarked versus OGG(aoTuv Beta 6.03) by three pair of stereo audio frames and one broadcast like voice audio frame with each frame consisting 2,028 samples at 44,100KHz sampling frequency.

  14. Distal lower extremity sarcomas: frequency of occurrence and patient survival rate.

    PubMed

    Zeytoonjian, Trisha; Mankin, Henry J; Gebhardt, Mark C; Hornicek, Francis J

    2004-05-01

    Primary sarcomas in the distal leg, tibia, fibula, ankle, and foot are uncommon and are believed to be less malignant than those that arise in other sites, but only limited information is available to support this contention. Using a computerized system containing extensive information regarding over 14,000 patients, mostly with tumors treated by our center over a 25-year period, 175 sarcomatous lesions with MSTS stage I, II, and III were located in the distal lower extremity. These were compared with 2367 lesions of similar diagnoses in other body parts. The principal studies included diagnostic distribution and outcome (recorded as death as a result of disease). Data were compared for diagnosis, gender, age, Musculoskeletal Tumor Society (MSTS) stage, anatomic site, and treatment methods and evaluated statistically by chi-square methods. The most frequent distal lower limb tumors were synovial cell sarcoma, osteosarcoma, and Ewing's tumor and the percentage distribution of the various tumors for that site as compared with the rest of the body was quite different. Of even more importance was the remarkable difference in outcome with the death rate for the lower limb tumors set at 10%, while the same tumors at other sites had a death rate of 27% (p <.000002). Furthermore, gender, stage, age, and the type of operative procedure showed highly significant differences between the tumors of the lower leg and those of the remainder of the body. On the basis of these data, it is evident that far fewer sarcomas occur in the lower leg, tibia, fibula, ankle, and foot than in other body sites and that their diagnostic distribution is different. Of perhaps greater interest is the fact that the rate of metastasis and death is markedly reduced for this site as compared with others. The authors speculate on the causes of this remarkable alteration in numbers and outcome.

  15. Clinical and radiographic analysis of c5 palsy after anterior cervical decompression and fusion for cervical degenerative disease.

    PubMed

    Kim, Sungjin; Lee, Sun-Ho; Kim, Eun-Sang; Eoh, Whan

    2014-12-01

    A retrospective cohort study. To present the cases of 6 patients who developed C5 palsy after anterior decompression and discuss the mechanism of C5 palsy development, especially with respect to radiographic change. C5 palsy has been reported to be a major complication of both anterior and posterior decompression procedures. Although several mechanisms of injury have been proposed, few reports have been issued on C5 palsy after anterior decompression surgery. A retrospective medical record review was performed on 134 patients who underwent anterior decompression and fusion in our hospital from 2008 to 2011. C5 paralysis was defined as deterioration in muscle power of the deltoid or biceps brachii by at least 1 grade by manual muscle testing. Clinical features and radiologic parameters were evaluated to identify predisposing factors. Six patients (4.3%) suffered postoperative paralysis in the upper extremities (C5 radiculopathy). C5 palsy did not occur in 30 patients with radiculopathy. Excluding patients with cervical radiculopathy, the rate of C5 palsies was 5.8% for myelopathy patients. Three of 76 (3.95'%) cervical spondylotic myelopathy cases, one of 6 (16.7%) cervical spondylotic radiculomyelopathy patients, and 2 of 22 (9%) patients with ossification of the posterior longitudinal ligament showed C5 palsy. In 2 of the 6, C5 palsy developed after anterior cervical corpectomy, in 3 patients after anterior cervical discectomy and plate fusion, and in 1 after a standalone cage. Two patients underwent reoperation for foraminal decompression. Of the 4 treated conservatively, 3 fully recovered and the other almost fully improved (grade 4). Of 2 patients treated surgically, 1 showed full improvements. The other had no improvement. Radiographic measurements of these 6 patients showed that lordosis at operated segments increased postoperatively (mean, 6 degrees), and that overall sagittal alignments of the cervical spine (C3-C7) also increased (mean, 8.2 degrees). This

  16. Potential Fifty Percent Reduction in Saturation Diving Decompression Time Using a Combination of Intermittent Recompression and Exercise

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael I.; Abercromby, Andrew; Conklin, Johnny

    2007-01-01

    Conventional saturation decompression protocols use linear decompression rates that become progressively slower at shallower depths, consistent with free gas phase control vs. dissolved gas elimination kinetics. If decompression is limited by control of free gas phase, linear decompression is an inefficient strategy. The NASA prebreathe reduction program demonstrated that exercise during O2 prebreathe resulted in a 50% reduction (2 h vs. 4 h) in the saturation decompression time from 14.7 to 4.3 psi and a significant reduction in decompression sickness (DCS: 0 vs. 23.7%). Combining exercise with intermittent recompression, which controls gas phase growth and eliminates supersaturation before exercising, may enable more efficient saturation decompression schedules. A tissue bubble dynamics model (TBDM) was used in conjunction with a NASA exercise prebreathe model (NEPM) that relates tissue inert gas exchange rate constants to exercise (ml O2/kg-min), to develop a schedule for decompression from helium saturation at 400 fsw. The models provide significant prediction (p < 0.001) and goodness of fit with 430 cases of DCS in 6437 laboratory dives for TBDM (p = 0.77) and with 22 cases of DCS in 159 altitude exposures for NEPM (p = 0.70). The models have also been used operationally in over 25,000 dives (TBDM) and 40 spacewalks (NEPM). The standard U.S. Navy (USN) linear saturation decompression schedule from saturation at 400 fsw required 114.5 h with a maximum Bubble Growth Index (BGI(sub max)) of 17.5. Decompression using intermittent recompression combined with two 10 min exercise periods (75% VO2 (sub peak)) per day required 54.25 h (BGI(sub max): 14.7). Combined intermittent recompression and exercise resulted in a theoretical 53% (2.5 day) reduction in decompression time and theoretically lower DCS risk compared to the standard USN decompression schedule. These results warrant future decompression trials to evaluate the efficacy of this approach.

  17. Potential Fifty Percent Reduction in Saturation Diving Decompression Time Using a Combination of Intermittent Recompression and Exercise

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael I.; Abercromby, Andrew; Conklin, Johnny

    2007-01-01

    Conventional saturation decompression protocols use linear decompression rates that become progressively slower at shallower depths, consistent with free gas phase control vs. dissolved gas elimination kinetics. If decompression is limited by control of free gas phase, linear decompression is an inefficient strategy. The NASA prebreathe reduction program demonstrated that exercise during O2 prebreathe resulted in a 50% reduction (2 h vs. 4 h) in the saturation decompression time from 14.7 to 4.3 psi and a significant reduction in decompression sickness (DCS: 0 vs. 23.7%). Combining exercise with intermittent recompression, which controls gas phase growth and eliminates supersaturation before exercising, may enable more efficient saturation decompression schedules. A tissue bubble dynamics model (TBDM) was used in conjunction with a NASA exercise prebreathe model (NEPM) that relates tissue inert gas exchange rate constants to exercise (ml O2/kg-min), to develop a schedule for decompression from helium saturation at 400 fsw. The models provide significant prediction (p < 0.001) and goodness of fit with 430 cases of DCS in 6437 laboratory dives for TBDM (p = 0.77) and with 22 cases of DCS in 159 altitude exposures for NEPM (p = 0.70). The models have also been used operationally in over 25,000 dives (TBDM) and 40 spacewalks (NEPM). The standard U.S. Navy (USN) linear saturation decompression schedule from saturation at 400 fsw required 114.5 h with a maximum Bubble Growth Index (BGI(sub max)) of 17.5. Decompression using intermittent recompression combined with two 10 min exercise periods (75% VO2 (sub peak)) per day required 54.25 h (BGI(sub max): 14.7). Combined intermittent recompression and exercise resulted in a theoretical 53% (2.5 day) reduction in decompression time and theoretically lower DCS risk compared to the standard USN decompression schedule. These results warrant future decompression trials to evaluate the efficacy of this approach.

  18. WEAK LINE QUASARS AT HIGH REDSHIFT: EXTREMELY HIGH ACCRETION RATES OR ANEMIC BROAD-LINE REGIONS?

    SciTech Connect

    Shemmer, Ohad; Trakhtenbrot, Benny; Netzer, Hagai; Anderson, Scott F.; Brandt, W. N.; Schneider, Donald P.; Diamond-Stanic, Aleksandar M.; Fan Xiaohui; Lira, Paulina; Plotkin, Richard M.; Richards, Gordon T.; Strauss, Michael A.

    2010-10-20

    We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z = 3.55 and SDSS J123743.08+630144.9 at z = 3.49. In both sources, we detect an unusually weak broad H{beta} line and place tight upper limits on the strengths of their [O III] lines. Virial, H{beta}-based black hole mass determinations indicate normalized accretion rates of L/L {sub Edd}=0.4 for these sources, which is well within the range observed for typical quasars with similar luminosities and redshifts. We also present high-quality XMM-Newton imaging spectroscopy of SDSS J114153.34+021924.3 and find a hard-X-ray photon index of {Gamma} = 1.91{sup +0.24} {sub -0.22}, which supports the virial L/L {sub Edd} determination in this source. Our results suggest that the weakness of the broad emission lines in WLQs is not a consequence of an extreme continuum-emission source but instead due to abnormal broad emission line region properties.

  19. Weak Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-line Regions?

    NASA Astrophysics Data System (ADS)

    Shemmer, Ohad; Trakhtenbrot, Benny; Anderson, Scott F.; Brandt, W. N.; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Lira, Paulina; Netzer, Hagai; Plotkin, Richard M.; Richards, Gordon T.; Schneider, Donald P.; Strauss, Michael A.

    2010-10-01

    We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z = 3.55 and SDSS J123743.08+630144.9 at z = 3.49. In both sources, we detect an unusually weak broad Hβ line and place tight upper limits on the strengths of their [O III] lines. Virial, Hβ-based black hole mass determinations indicate normalized accretion rates of L/L Edd=0.4 for these sources, which is well within the range observed for typical quasars with similar luminosities and redshifts. We also present high-quality XMM-Newton imaging spectroscopy of SDSS J114153.34+021924.3 and find a hard-X-ray photon index of Γ = 1.91+0.24 -0.22, which supports the virial L/L Edd determination in this source. Our results suggest that the weakness of the broad emission lines in WLQs is not a consequence of an extreme continuum-emission source but instead due to abnormal broad emission line region properties.

  20. 'Melt welt' mechanism of extreme weakening of gabbro at seismic slip rates.

    PubMed

    Brown, Kevin M; Fialko, Yuri

    2012-08-30

    Laboratory studies of frictional properties of rocks at slip velocities approaching the seismic range (∼0.1-1 m s(-1)), and at moderate normal stresses (1-10 MPa), have revealed a complex evolution of the dynamic shear strength, with at least two phases of weakening separated by strengthening at the onset of wholesale melting. The second post-melting weakening phase is governed by viscous properties of the melt layer and is reasonably well understood. The initial phase of extreme weakening, however, remains a subject of much debate. Here we show that the initial weakening of gabbro is associated with the formation of hotspots and macroscopic streaks of melt ('melt welts'), which partially unload the rest of the slip interface. Melt welts begin to form when the average rate of frictional heating exceeds 0.1-0.4 MW m(-2), while the average temperature of the shear zone is well below the solidus (250-450 °C). Similar heterogeneities in stress and temperature are likely to occur on natural fault surfaces during rapid slip, and to be important for earthquake rupture dynamics.

  1. Extremely high rate deposition of polymer multilayer optical thin film materials

    SciTech Connect

    Affinito, J.D.

    1993-01-01

    This paper highlights a new technique for extremely high rate deposition of optical dielectric films (vacuum deposition of polymer multilayer thin films). This is a way to produce multilayer optical filters comprised of thousands of layers of either linear or nonlinear optical materials. The technique involves the flash evaporation of an acrylic monomer onto a moving substrate; the monomer is then cured. Acrylic polymers deposited to date are very clear for wavelengths between 0.35 and 2.5 [mu]m; they have extinction coefficients of k[approx]10[sup [minus]7]. Application of electric field during cross linking can polarize (''pole'') the film to greatly enhance the nonlinear optical properties. ''Poling'' films with the polymer multilayer technique offers advantages over conventional approaches, in that the polarization should not decay over time. Battelle's Pacific Northwest Laboratory is well suited for bringing linear and nonlinear polymer multilayer optical filter technology to manufacturing production status for batch and wide area web applications. 10 figs.

  2. Extremely high rate deposition of polymer multilayer optical thin film materials

    SciTech Connect

    Affinito, J.D.

    1993-03-01

    This paper highlights a new technique for extremely high rate deposition of optical dielectric films (vacuum deposition of polymer multilayer thin films). This is a way to produce multilayer optical filters comprised of thousands of layers of either linear or nonlinear optical materials. The technique involves the flash evaporation of an acrylic monomer onto a moving substrate; the monomer is then cured. Acrylic polymers deposited to date are very clear for wavelengths between 0.35 and 2.5 {mu}m; they have extinction coefficients of k{approx}10{sup {minus}7}. Application of electric field during cross linking can polarize (``pole``) the film to greatly enhance the nonlinear optical properties. ``Poling`` films with the polymer multilayer technique offers advantages over conventional approaches, in that the polarization should not decay over time. Battelle`s Pacific Northwest Laboratory is well suited for bringing linear and nonlinear polymer multilayer optical filter technology to manufacturing production status for batch and wide area web applications. 10 figs.

  3. Spaceflight Decompression Sickness Contingency Plan

    NASA Technical Reports Server (NTRS)

    Dervay, Joseph P.

    2007-01-01

    A viewgraph presentation on the Decompression Sickness (DCS) Contingency Plan for manned spaceflight is shown. The topics include: 1) Approach; 2) DCS Contingency Plan Overview; 3) Extravehicular Activity (EVA) Cuff Classifications; 4) On-orbit Treatment Philosophy; 5) Long Form Malfunction Procedure (MAL); 6) Medical Checklist; 7) Flight Rules; 8) Crew Training; 9) Flight Surgeon / Biomedical Engineer (BME) Training; and 10) DCS Emergency Landing Site.

  4. Eruptive dynamics during magma decompression: a laboratory approach

    NASA Astrophysics Data System (ADS)

    Spina, L.; Cimarelli, C.; Scheu, B.; Wadsworth, F.; Dingwell, D. B.

    2013-12-01

    A variety of eruptive styles characterizes the activity of a given volcano. Indeed, eruptive styles can range from effusive phenomena to explosive eruptions, with related implications for hazard management. Rapid changes in eruptive style can occur during an ongoing eruption. These changes are, amongst other, related to variations in the magma ascent rate, a key parameter affecting the eruptive style. Ascent rate is in turn dependent on several factors such as the pressure in the magma chamber, the physical properties of the magma and the rate at which these properties change. According to the high number of involved parameters, laboratory decompression experiments are the best way to achieve quantitative information on the interplay of each of those factors and the related impact on the eruption style, i.e. by analyzing the flow and deformation behavior of the transparent volatile-bearing analogue fluid. We carried out decompression experiments following different decompression paths and using silicone oil as an analogue for the melt, with which we can simulate a range of melt viscosity values. For a set of experiments we added rigid particles to simulate the presence of crystals in the magma. The pure liquid or suspension was mounted into a transparent autoclave and pressurized to different final pressures. Then the sample was saturated with argon for a fixed amount of time. The decompression path consists of a slow decompression from the initial pressure to the atmospheric condition. Alternatively, samples were decompressed almost instantaneously, after established steps of slow decompression. The decompression path was monitored with pressure transducers and a high-speed video camera. Image analysis of the videos gives quantitative information on the bubble distribution with respect to depth in the liquid, pressure and time of nucleation and on their characteristics and behavior during the ongoing magma ascent. Furthermore, we also monitored the evolution of

  5. Modeling Magma Decompression During the 1912 Plinian Eruption at Novarupta, Alaska

    NASA Astrophysics Data System (ADS)

    Gonnermann, H. M.; Houghton, B. F.; Adams, N. K.; Hildreth, E. W.

    2009-12-01

    We model the vesicle size distribution for samples of dacitic pumice from the 1912 Plinian eruption at Novarupta, Alaska, using a numerical model for bubble nucleation and bubble growth. In our model bubble nucleation is based on classical nucleation theory and bubble growth includes diffusive volatile exsolution, as well as decompressive expansion of exsolved volatiles. Model results are fit to the measured vesicle size distribution, determined from scanning electron microscope analysis of polished thin sections, by varying the magma decompression rate during ascent to the surface. The resultant time-dependent decompression rate indicates modest decompression rates, except during the last few hundred milliseconds before the sample was quenched. At this time decompression rates are predicted to have reached about 100 MPa/s, required to produce the abundance of micron-size vesicles. Because the bubbles that produced these micron-size vesicles would have grown within fractions of a second to significantly larger size, the high decompression rates must have been abruptly terminated by magma quench. We interpret the rapid increase in decompression rate as a consequence of magma entering the fragmentation level, where pressure gradients are expected to be large. Our results indicated that during this final, rapid decompression a sufficient volume fraction of bubbles develop high enough overpressures to result in brittle magma fragmentation. This is consistent with a sustained feedback between rapid decompression and fragmentation during Plinian eruptions. Modeled vs. measured vesicle size distribution for Novarupta dacite lapilli 94-1-8-9 of Adams et al., Bull. Volcanol., 69 (2006) 189-206.

  6. European EVA decompression sickness risks

    NASA Astrophysics Data System (ADS)

    Vogt, Lorenz; Wenzel, Jürgen; Skoog, A. I.; Luck, S.; Svensson, Bengt

    For the first manned flight of Hermes there will be a capability of performing EVA. The European EVA Space Suit will be an anthropomorphic system with an internal pressure of 500 hPa of pure oxygen. The pressure reduction from the Hermes cabin pressure of 1013 hPa will induce a risk for Decompression Sickness (DCS) for the EVA crewmember if no adequate protective procedures are implemented. Specific decompression procedures have to be developed. From a critical review of the literature and by using knowledge gained from research conducted in the past in the fields of diving and aerospace medicine safe protective procedures are proposed for the European EVA scenario. An R factor of 1.2 and a tissue half-time ( t1/2) of 360 minutes in a single-tissue model have been identified as appropriate operational values. On the basis of an acceptable risk level of approximately 1%, oxygen prebreathing times are proposed for (a) direct pressure reduction from 1013 hPa to a suit pressure of 500 hPa, and (b) staged decompression using a 700 hPa intermediate stage in the spacecraft cabin. In addition, factors which influence individual susceptibility to DCS are identified. Recommendations are also given in the areas of crew selection and medical monitoring requirements together with therapeutic measures that can be implemented in the Hermes scenario. A method for demonstration of the validity of proposed risks and procedures is proposed.

  7. Optic nerve decompression in osteopetrosis.

    PubMed

    Al-Mefty, O; Fox, J L; Al-Rodhan, N; Dew, J H

    1988-01-01

    Osteopetrosis is a rare disorder characterized by generalized increased skeletal density with abnormalities of bone modeling. The skull base is usually involved. Loss of vision with optic nerve atrophy is the most common neurological finding and is traditionally believed to be the result of optic nerve compression within the compromised optic canal. However, retinal degeneration has recently been described and is hypothesized to be the etiology of the visual loss (thus challenging the value of surgical decompression). The authors report their experience with six children suffering from osteopetrosis and severe visual loss. All six patients underwent bilateral microsurgical optic nerve decompression through a supraorbital craniotomy. Improvement in visual acuity occurred postoperatively in five patients, and none had complications. Two technical points are emphasized: 1) optic nerve decompression should be wide and include not only unroofing of the canal but also drilling along both sides of the optic nerve, and 2) the thick, irregular, and highly domed orbital roof should be smoothed down by high-speed drilling to facilitate surgical exposure with minimal retraction of the frontal lobe.

  8. [Severe decompression sickness in divers].

    PubMed

    Beuster, W; van Laak, U

    1999-01-01

    The term "decompression illness (DCI)" is a disorder which arises from the presence of ectopic gas bubbles following decompression. Scuba diving poses the risk of two typically clinical syndromes: decompression sickness (DCS) and arterial gas embolism (AGE). DCS results from the formation of gas bubbles in the tissues of the body and in the blood due to rapid reduction of the environmental pressure. AGE is caused by pulmonary overinflation if the breathing gas cannot be exhaled adequately during the ascent. Although the pathophysiological mechanisms of these two disorders are quite different, both of them lead to the same result: inert gas bubbles that may cause impairment of vital functions due to hypoxia. Recognizing the signs and symptoms of DCI is the first step of the therapy. The emergency treatment contains: basic life support, advanced life support--if necessary, horizontal positioning of the victim, administration of 100% normobaric oxygen via face mask or endotracheal tube, rehydration, rapid transportation to the nearest emergency department/hyperbaric facility for definitive treatment in order to prevent serious neurological sequelae.

  9. Crystallization kinetics in magmas during decompression

    NASA Astrophysics Data System (ADS)

    Arzilli, Fabio; Burton, Mike; Carroll, Michael R.

    2016-04-01

    Many variables play a role during magma crystallization at depth or in a volcanic conduit, and through experimentally derived constraints we can better understand pre- and syn-eruptive magma crystallization behavior. The thermodynamic properties of magmas have been extensively investigated as a function of T, P, fO2 and magma composition [1], and this allows estimation of the stability of equilibrium phases and physical parameters (e.g., density, viscosity). However, many natural igneous rocks contain geochemical, mineralogical and textural evidence of disequilibrium, suggesting that magmas frequently follow non-equilibrium, time-dependent pathways that are recorded in the geochemical and petrographic characteristics of the rocks. There are currently no suitable theoretical models capable of calculating nucleation and growth rates in disequilibrium conditions without experimental constraints. The aim of this contribution is provide quantitative data on growth and nucleation rates of feldspar crystals in silicate melts obtained through decompression experiments, in order to determine the magma evolution in pre- and sin-eruptive conditions. Decompression is one of the main processes that induce the crystallization of feldspar during the magma ascent in the volcanic conduit. Decompression experiments have been carried out on trachytic and basaltic melts to investigate crystallization kinetics of feldspar as a function of the effect of the degassing, undercooling and time on nucleation and crystal growth process [2; 3]. Furthermore, feldspar is the main crystals phase present in magmas, and its abundance can strongly vary with small changes in pressure, temperature and water content in the melt, implying appreciable variations in the textures and in the crystallization kinetics. Crystallization kinetics of trachytic melts show that long experiment durations involve more nucleation events of alkali feldspar than short experiment durations [2]. This is an important

  10. A Tool for Rating the Resilience of Critical Infrastructures in Extreme Fires

    DTIC Science & Technology

    2014-05-01

    against extreme fires. An Advisory Board was formed with 15 members from government departments, fire services, engineering and extreme fire experts...fire resistance evaluation of critical structures or any HJA 43 acceptable curve following an engineering analysis. The RWS time-temperature...Ministry of Transport in the Netherlands based on the assumption that, in a worst case scenario, a 50 m3 fuel, oil or petrol tanker fire, with a fire load

  11. On diver thermal status and susceptibility to decompression sickness.

    PubMed

    Gerth, Wayne A

    2015-09-01

    In a recent Letter to the Editor, Clarke, et al, indicated that divers who deliberately chill themselves on a dive to reduce risk of decompression sickness (DCS) may be misinterpreting our 2007 Navy Experimental Diving Unit (NEDU) report. Indeed, we did not advocate that divers should risk hypothermia on bottom to reduce risk of DCS, nor do we dispute the authors' overall admonition to avoid diving cold unnecessarily. However, Clarke, et al, imply more generally that results of our study are not applicable to recreational or technical divers because the dives we tested were atypical of dives undertaken by such divers. We wish to clarify that our study does have implications for recreational and technical divers, implications that should not be ignored. The dives we tested were not intended to be typical of dives undertaken in any actual operational context. Instead, we chose to expose divers to temperatures at the extremes of their thermal tolerance in order to ensure that effects of diver thermal status on DCS susceptibility would be found if such effects existed. Our initial test dive profile provided appreciable time both on bottom and during decompression to allow any differential thermal effects during these two dive phases to manifest, while affording a baseline risk of DCS that could be altered by thermal effects without exposing subjects to inordinately high risks of DCS. Our results strongly indicate that the optimal diver thermal conditions for mitigation of DCS risk or minimization of decompression time entail remaining cool during gas uptake phases of a dive and warm during off-gassing phases. While the dose-response characteristics of our observed thermal effects are almost certainly non-linear in both exposure temperature and duration, it is only reasonable to presume that the effects vary monotonically with these factors. We have no reason to presume that such responses and effects under less extreme conditions would be in directions opposite to

  12. Response Styles in Rating Scales: Simultaneous Modeling of Content-Related Effects and the Tendency to Middle or Extreme Categories

    ERIC Educational Resources Information Center

    Tutz, Gerhard; Berger, Moritz

    2016-01-01

    Heterogeneity in response styles can affect the conclusions drawn from rating scale data. In particular, biased estimates can be expected if one ignores a tendency to middle categories or to extreme categories. An adjacent categories model is proposed that simultaneously models the content-related effects and the heterogeneity in response styles.…

  13. Response Styles in Rating Scales: Simultaneous Modeling of Content-Related Effects and the Tendency to Middle or Extreme Categories

    ERIC Educational Resources Information Center

    Tutz, Gerhard; Berger, Moritz

    2016-01-01

    Heterogeneity in response styles can affect the conclusions drawn from rating scale data. In particular, biased estimates can be expected if one ignores a tendency to middle categories or to extreme categories. An adjacent categories model is proposed that simultaneously models the content-related effects and the heterogeneity in response styles.…

  14. Thalmann Algorithm Decompression Table Generation Software Design Document

    DTIC Science & Technology

    2010-09-01

    Decompression Table Generation Software Design Document Navy Experimental Diving Unit Author...TITLE (Include Security Classification) (U) THALMANN ALGORITHM DECOMPRESSION TABLE GENERATION SOFTWARE DESIGN DOCUMENT 12. PERSONAL AUTHOR(S...1 2. Decompression Table Generator (TBLP7R

  15. Comparison of Extreme Pressure Additive Treat Rates in Soybean and Mineral Oils Under Boundary Lubrication Conditions

    USDA-ARS?s Scientific Manuscript database

    Traditionally, it is considered that, under boundary lubrication conditions, the reduction in friction and wear is mostly dependent on Extreme Pressure (EP) additives, rather than the basestock. However, several studies indicate that vegetable oils also contribute to the lubricity under this regime...

  16. Drop-box Weir for Measuring Flow Rates Under Extreme Flow Conditions

    USDA-ARS?s Scientific Manuscript database

    Sediment and large rocks often are transported in runoff during extreme events. The sediment can deposit in a runoff-measuring structure and give erroneous readings. The drop-box weir (DBW) is one of only a few flow-measuring devices capable of measuring sediment-laden flows. Recent studies have ...

  17. The Extended Oxygen Window Concept for Programming Saturation Decompressions Using Air and Nitrox.

    PubMed

    Kot, Jacek; Sicko, Zdzislaw; Doboszynski, Tadeusz

    2015-01-01

    Saturation decompression is a physiological process of transition from one steady state, full saturation with inert gas at pressure, to another one: standard conditions at surface. It is defined by the borderline condition for time spent at a particular depth (pressure) and inert gas in the breathing mixture (nitrogen, helium). It is a delicate and long lasting process during which single milliliters of inert gas are eliminated every minute, and any disturbance can lead to the creation of gas bubbles leading to decompression sickness (DCS). Most operational procedures rely on experimentally found parameters describing a continuous slow decompression rate. In Poland, the system for programming of continuous decompression after saturation with compressed air and nitrox has been developed as based on the concept of the Extended Oxygen Window (EOW). EOW mainly depends on the physiology of the metabolic oxygen window--also called inherent unsaturation or partial pressure vacancy--but also on metabolism of carbon dioxide, the existence of water vapor, as well as tissue tension. Initially, ambient pressure can be reduced at a higher rate allowing the elimination of inert gas from faster compartments using the EOW concept, and maximum outflow of nitrogen. Then, keeping a driving force for long decompression not exceeding the EOW allows optimal elimination of nitrogen from the limiting compartment with half-time of 360 min. The model has been theoretically verified through its application for estimation of risk of decompression sickness in published systems of air and nitrox saturation decompressions, where DCS cases were observed. Clear dose-reaction relation exists, and this confirms that any supersaturation over the EOW creates a risk for DCS. Using the concept of the EOW, 76 man-decompressions were conducted after air and nitrox saturations in depth range between 18 and 45 meters with no single case of DCS. In summary, the EOW concept describes physiology of

  18. The Extended Oxygen Window Concept for Programming Saturation Decompressions Using Air and Nitrox

    PubMed Central

    Kot, Jacek; Sicko, Zdzislaw

    2015-01-01

    Saturation decompression is a physiological process of transition from one steady state, full saturation with inert gas at pressure, to another one: standard conditions at surface. It is defined by the borderline condition for time spent at a particular depth (pressure) and inert gas in the breathing mixture (nitrogen, helium). It is a delicate and long lasting process during which single milliliters of inert gas are eliminated every minute, and any disturbance can lead to the creation of gas bubbles leading to decompression sickness (DCS). Most operational procedures rely on experimentally found parameters describing a continuous slow decompression rate. In Poland, the system for programming of continuous decompression after saturation with compressed air and nitrox has been developed as based on the concept of the Extended Oxygen Window (EOW). EOW mainly depends on the physiology of the metabolic oxygen window—also called inherent unsaturation or partial pressure vacancy—but also on metabolism of carbon dioxide, the existence of water vapor, as well as tissue tension. Initially, ambient pressure can be reduced at a higher rate allowing the elimination of inert gas from faster compartments using the EOW concept, and maximum outflow of nitrogen. Then, keeping a driving force for long decompression not exceeding the EOW allows optimal elimination of nitrogen from the limiting compartment with half-time of 360 min. The model has been theoretically verified through its application for estimation of risk of decompression sickness in published systems of air and nitrox saturation decompressions, where DCS cases were observed. Clear dose-reaction relation exists, and this confirms that any supersaturation over the EOW creates a risk for DCS. Using the concept of the EOW, 76 man-decompressions were conducted after air and nitrox saturations in depth range between 18 and 45 meters with no single case of DCS. In summary, the EOW concept describes physiology of

  19. Graphics processing unit-assisted lossless decompression

    DOEpatents

    Loughry, Thomas A.

    2016-04-12

    Systems and methods for decompressing compressed data that has been compressed by way of a lossless compression algorithm are described herein. In a general embodiment, a graphics processing unit (GPU) is programmed to receive compressed data packets and decompress such packets in parallel. The compressed data packets are compressed representations of an image, and the lossless compression algorithm is a Rice compression algorithm.

  20. Minimally invasive surgical decompression for lumbar spinal metastases

    PubMed Central

    Kimball, Jon; Kusnezov, Nicholas A.; Pezeshkian, Patrick; Lu, Daniel C.

    2013-01-01

    Background: The risk of significant morbidity and mortality often outweighs the benefit of surgical resection as palliative treatment for patients with high systemic disease burden, poor cardiopulmonary status, and previous spinal surgeries. Minimally invasive surgical (MIS) approaches to decompressing metastatic epidural cord compression (MECC) can address these issues and thereby make palliation a feasible option for these patients. Case Description: We present the cases of three consecutively collected patients with severe neurological compromise secondary to lumbar epidural metastases who underwent MIS decompression and achieved improved functional outcome and quality of life. The first patient is a 23-year-old female with metastatic Ewing's sarcoma who presented with 2 weeks of a right foot drop and radiculopathic pain. The next case is that of a 71-year-old male with metastatic prostate cancer who presented with significant radiculopathic L5-S1 pain and severe motor deficits in his lower extremities. The last case is that of a 73-year-old male with metastatic hepatocellular carcinoma who presented with worsening left leg weakness, paresthesia, and dysethesia. Postoperatively, each patient experienced significant improvement and almost complete enduring return of function, strength, and resolution of pain. Conclusion: We demonstrate that MIS approaches to spinal decompression as palliative treatment for metastatic disease is a viable treatment in patients with a focal symptomatic lesion and comes with the benefits of decreased surgical morbidity inherent to the minimally invasive approach as well as excellent functional outcomes. PMID:23869278

  1. Comparison of outcomes following decompressive craniectomy in children with accidental and nonaccidental blunt cranial trauma.

    PubMed

    Oluigbo, Chima O; Wilkinson, C Corbett; Stence, Nicholas V; Fenton, Laura Z; McNatt, Sean A; Handler, Michael H

    2012-02-01

    The goal of this study was to compare clinical outcomes following decompressive craniectomy performed for intracranial hypertension in children with nonaccidental, blunt cranial trauma with outcomes of decompressive craniectomy in children injured by other mechanisms. All children in a prospectively acquired database of trauma admissions who underwent decompressive craniectomy over a 9-year span, beginning January 1, 2000, are the basis for this study. Clinical records and neuroimaging studies were systematically reviewed. Thirty-seven children met the inclusion criteria. Nonaccidental head trauma was the most common mechanism of injury (38%). The mortality rate in patients with abusive brain injury (35.7%) was significantly higher (p < 0.05) than in patients with other causes of traumatic brain injury (4.3%). Children with inflicted head injuries had a 12-fold increase in the odds of death and 3-fold increase in the odds of a poor outcome (King's Outcome Scale for Closed Head Injury score of 1, 2, or 3). Children with nonaccidental blunt cranial trauma have significantly higher mortality following decompressive craniectomy than do children with other mechanisms of injury. This understanding can be interpreted to mean either that the threshold for decompression should be lower in children with nonaccidental closed head injury or that decompression is unlikely to alter the path to a fatal outcome. If decompressive craniectomy is to be effective in reducing mortality in the setting of nonaccidental blunt cranial trauma, it should be done quite early.

  2. Xenon Blocks Neuronal Injury Associated with Decompression

    PubMed Central

    Blatteau, Jean-Eric; David, Hélène N.; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H.

    2015-01-01

    Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS. PMID:26469983

  3. Xenon Blocks Neuronal Injury Associated with Decompression.

    PubMed

    Blatteau, Jean-Eric; David, Hélène N; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H

    2015-10-15

    Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS.

  4. Pressureless Orbital Decompression for Myopic Proptosis.

    PubMed

    Rajak, Saul N; McGovern, Richard A; Selva, Dinesh

    2017-01-01

    Orbital decompression surgery increases the orbital volume. It has rarely been used for proptosis of the large highly myopic globe. However, external decompression surgery carries significant risks because of the large thin-walled globe. The authors report the first use of endoscopic medial wall orbital decompression surgery in this setting to obviate the risk of globe pressure.Endoscopic medial wall decompression brought about a 4 mm reduction of proptosis, correction of exotropia and elimination of retrobulbar ache providing good symmetry with the fellow eye.Endoscopic medial wall orbital decompression can be very effective for correcting the proptosis of high myopia and minimizes the risk of damage to the very large, thin-walled globe.

  5. Putative extremely high rate of proteome innovation in lancelets might be explained by high rate of gene prediction errors

    PubMed Central

    Bányai, László; Patthy, László

    2016-01-01

    A recent analysis of the genomes of Chinese and Florida lancelets has concluded that the rate of creation of novel protein domain combinations is orders of magnitude greater in lancelets than in other metazoa and it was suggested that continuous activity of transposable elements in lancelets is responsible for this increased rate of protein innovation. Since morphologically Chinese and Florida lancelets are highly conserved, this finding would contradict the observation that high rates of protein innovation are usually associated with major evolutionary innovations. Here we show that the conclusion that the rate of proteome innovation is exceptionally high in lancelets may be unjustified: the differences observed in domain architectures of orthologous proteins of different amphioxus species probably reflect high rates of gene prediction errors rather than true innovation. PMID:27476717

  6. Putative extremely high rate of proteome innovation in lancelets might be explained by high rate of gene prediction errors.

    PubMed

    Bányai, László; Patthy, László

    2016-08-01

    A recent analysis of the genomes of Chinese and Florida lancelets has concluded that the rate of creation of novel protein domain combinations is orders of magnitude greater in lancelets than in other metazoa and it was suggested that continuous activity of transposable elements in lancelets is responsible for this increased rate of protein innovation. Since morphologically Chinese and Florida lancelets are highly conserved, this finding would contradict the observation that high rates of protein innovation are usually associated with major evolutionary innovations. Here we show that the conclusion that the rate of proteome innovation is exceptionally high in lancelets may be unjustified: the differences observed in domain architectures of orthologous proteins of different amphioxus species probably reflect high rates of gene prediction errors rather than true innovation.

  7. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    SciTech Connect

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. In this article, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s-1 is generated at 22.3 eV, with 5 × 10-5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Finally, spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  8. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV.

    PubMed

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S; Ranitovic, Predrag; Kaindl, Robert A

    2015-06-11

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 10(13) s(-1) is generated at 22.3 eV, with 5 × 10(-5) conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications.

  9. Bright high-repetition-rate source of narrowband extreme-ultraviolet harmonics beyond 22 eV

    PubMed Central

    Wang, He; Xu, Yiming; Ulonska, Stefan; Robinson, Joseph S.; Ranitovic, Predrag; Kaindl, Robert A.

    2015-01-01

    Novel table-top sources of extreme-ultraviolet light based on high-harmonic generation yield unique insight into the fundamental properties of molecules, nanomaterials or correlated solids, and enable advanced applications in imaging or metrology. Extending high-harmonic generation to high repetition rates portends great experimental benefits, yet efficient extreme-ultraviolet conversion of correspondingly weak driving pulses is challenging. Here, we demonstrate a highly-efficient source of femtosecond extreme-ultraviolet pulses at 50-kHz repetition rate, utilizing the ultraviolet second-harmonic focused tightly into Kr gas. In this cascaded scheme, a photon flux beyond ≈3 × 1013 s−1 is generated at 22.3 eV, with 5 × 10−5 conversion efficiency that surpasses similar harmonics directly driven by the fundamental by two orders-of-magnitude. The enhancement arises from both wavelength scaling of the atomic dipole and improved spatio-temporal phase matching, confirmed by simulations. Spectral isolation of a single 72-meV-wide harmonic renders this bright, 50-kHz extreme-ultraviolet source a powerful tool for ultrafast photoemission, nanoscale imaging and other applications. PMID:26067922

  10. Superior outcomes of decompression with an interlaminar dynamic device versus decompression alone in patients with lumbar spinal stenosis and back pain: a cross registry study.

    PubMed

    Röder, C; Baumgärtner, B; Berlemann, U; Aghayev, E

    2015-10-01

    Surgical decompression for lumbar spinal stenosis (LSS) has been associated with poorer outcomes in patients with pronounced low back pain (LBP) as compared to patients with predominant leg pain. This cross registry study assessed potential benefits of the interlaminar coflex® device as an add-on to bony decompression alone. Patients with lumbar decompression plus coflex® (SWISSspine registry) were compared with decompressed controls (Spine Tango registry). Inclusion criteria were LSS and a preoperative back pain level of ≥5 points. 1:1 propensity score-based matching was performed. Outcome measures were back and leg pain relief, COMI score improvement, patient satisfaction, complication, and revision rates. 50 matched pairs without residual significant differences but age were created. At the 7-9 months follow-up interval the coflex® group had higher back (p=0.014) and leg pain relief (p<0.001) and COMI score improvement (p=0.029) than the decompression group. Patient satisfaction was 90% in both groups. No revision was documented in the coflex® and one in the decompression group (2.0%). In the short-term, lumbar decompression with coflex® compared with decompression alone in patients with LSS and pronounced LBP at baseline is a safe and effective treatment option that appears beneficial regarding clinical and functional outcomes. However, residual confounding of non-measured covariables may have partially influenced our findings. Also, despite careful inclusion and exclusion of cases the cross registry approach introduces a potential for selection bias that we could not totally control for and that makes additional studies necessary.

  11. Gas embolization of the liver in a rat model of rapid decompression.

    PubMed

    L'Abbate, Antonio; Kusmic, Claudia; Matteucci, Marco; Pelosi, Gualtiero; Navari, Alessandro; Pagliazzo, Antonino; Longobardi, Pasquale; Bedini, Remo

    2010-08-01

    Occurrence of liver gas embolism after rapid decompression was assessed in 31 female rats that were decompressed in 12 min after 42 min of compression at 7 ATA (protocol A). Sixteen rats died after decompression (group I). Of the surviving rats, seven were killed at 3 h (group II), and eight at 24 h (group III). In group I, bubbles were visible in the right heart, aortic arch, liver, and mesenteric veins and on the intestinal surface. Histology showed perilobular microcavities in sinusoids, interstitial spaces, and hepatocytes. In group II, liver gas was visible in two rats. Perilobular vacuolization and significant plasma aminotransferase increase were present. In group III, liver edema was evident at gross examination in all cases. Histology showed perilobular cell swelling, vacuolization, or hydropic degeneration. Compared with basal, enzymatic markers of liver damage increased significantly. An additional 14 rats were decompressed twice (protocol B). Overall mortality was 93%. In addition to diffuse hydropic degeneration, centrilobular necrosis was frequently observed after the second decompression. Additionally, 10 rats were exposed to three decompression sessions (protocol C) with doubled decompression time. Their mortality rate decreased to 20%, but enzymatic markers still increased in surviving rats compared with predecompression, and perilobular cell swelling and vacuolization were present in five rats. Study challenges were 1) liver is not part of the pathophysiology of decompression in the existing paradigm, and 2) although significant cellular necrosis was observed in few animals, zonal or diffuse hepatocellular damage associated with liver dysfunction was frequently demonstrated. Liver participation in human decompression sickness should be looked for and clinically evaluated.

  12. Allometric scaling of decompression sickness risk in terrestrial mammals; cardiac output explains risk of decompression sickness

    NASA Astrophysics Data System (ADS)

    Fahlman, Andreas

    2017-02-01

    A probabilistic model was used to predict decompression sickness (DCS) outcome in pig (70 and 20 kg), hamster (100 g), rat (220 g) and mouse (20 g) following air saturation dives. The data set included 179 pig, 200 hamster, 360 rat, and 224 mouse exposures to saturation pressures ranging from 1.9-15.2 ATA and with varying decompression rates (0.9-156 ATA • min-1). Single exponential kinetics described the tissue partial pressures (Ptiss) of N2: Ptiss =  ∫(Pamb - Ptiss) • τ-1 dt, where Pamb is ambient N2 pressure and τ is a time constant. The probability of DCS [P(DCS)] was predicted from the risk function: P(DCS) = 1-e-r, where r = ∫(PtissN2 - Thr - Pamb) • Pamb-1 dt, and Thr is a threshold parameter. An equation that scaled τ with body mass included a constant (c) and an allometric scaling parameter (n), and the best model included n, Thr, and two c. The final model provided accurate predictions for 58 out of 61 dive profiles for pig, hamster, rat, and mouse. Thus, body mass helped improve the prediction of DCS risk in four mammalian species over a body mass range covering 3 orders of magnitude.

  13. Allometric scaling of decompression sickness risk in terrestrial mammals; cardiac output explains risk of decompression sickness

    PubMed Central

    Fahlman, Andreas

    2017-01-01

    A probabilistic model was used to predict decompression sickness (DCS) outcome in pig (70 and 20 kg), hamster (100 g), rat (220 g) and mouse (20 g) following air saturation dives. The data set included 179 pig, 200 hamster, 360 rat, and 224 mouse exposures to saturation pressures ranging from 1.9–15.2 ATA and with varying decompression rates (0.9–156 ATA • min−1). Single exponential kinetics described the tissue partial pressures (Ptiss) of N2: Ptiss =  ∫(Pamb – Ptiss) • τ−1 dt, where Pamb is ambient N2 pressure and τ is a time constant. The probability of DCS [P(DCS)] was predicted from the risk function: P(DCS) = 1−e−r, where r = ∫(PtissN2 − Thr − Pamb) • Pamb–1 dt, and Thr is a threshold parameter. An equation that scaled τ with body mass included a constant (c) and an allometric scaling parameter (n), and the best model included n, Thr, and two c. The final model provided accurate predictions for 58 out of 61 dive profiles for pig, hamster, rat, and mouse. Thus, body mass helped improve the prediction of DCS risk in four mammalian species over a body mass range covering 3 orders of magnitude. PMID:28150725

  14. Allometric scaling of decompression sickness risk in terrestrial mammals; cardiac output explains risk of decompression sickness.

    PubMed

    Fahlman, Andreas

    2017-02-02

    A probabilistic model was used to predict decompression sickness (DCS) outcome in pig (70 and 20 kg), hamster (100 g), rat (220 g) and mouse (20 g) following air saturation dives. The data set included 179 pig, 200 hamster, 360 rat, and 224 mouse exposures to saturation pressures ranging from 1.9-15.2 ATA and with varying decompression rates (0.9-156 ATA • min(-1)). Single exponential kinetics described the tissue partial pressures (Ptiss) of N2: Ptiss =  ∫(Pamb - Ptiss) • τ(-1) dt, where Pamb is ambient N2 pressure and τ is a time constant. The probability of DCS [P(DCS)] was predicted from the risk function: P(DCS) = 1-e(-r), where r = ∫(PtissN2 - Thr - Pamb) • Pamb(-1) dt, and Thr is a threshold parameter. An equation that scaled τ with body mass included a constant (c) and an allometric scaling parameter (n), and the best model included n, Thr, and two c. The final model provided accurate predictions for 58 out of 61 dive profiles for pig, hamster, rat, and mouse. Thus, body mass helped improve the prediction of DCS risk in four mammalian species over a body mass range covering 3 orders of magnitude.

  15. [Classification of altitude decompression sickness].

    PubMed

    Katuntsev, V P

    2000-01-01

    The article is devoted to the discussion of principles of and approaches to classification of altitude decompression sickness (DCS), one of the most methodically formidable aspects of the problem. Based on his own multiyear experience in altitude DCS investigations and critical review of literature, the author reasons his concept of clinical classification of altitude DCS. The author's concept places emphasis on obligatory consideration of three stages in DCS development: A--pre-disease (the premorbid syndrome), B--uncomplicated (light) and C--complicated (severe) forms. The objective sign of the premorbid state is "silent" gas bubbles in organism detectable by ultrasonic devices. Signs of uncomplicated altitude DCS are musculoarticular pains, local edema and skin itching. Complicated altitude DCS is diagnosed by systemic (respiratory, neurological and cardiovascular) disorders.

  16. libpolycomp: Compression/decompression library

    NASA Astrophysics Data System (ADS)

    Tomasi, Maurizio

    2016-04-01

    Libpolycomp compresses and decompresses one-dimensional streams of numbers by means of several algorithms. It is well-suited for time-ordered data acquired by astronomical instruments or simulations. One of the algorithms, called "polynomial compression", combines two widely-used ideas (namely, polynomial approximation and filtering of Fourier series) to achieve substantial compression ratios for datasets characterized by smoothness and lack of noise. Notable examples are the ephemerides of astronomical objects and the pointing information of astronomical telescopes. Other algorithms implemented in this C library are well known and already widely used, e.g., RLE, quantization, deflate (via libz) and Burrows-Wheeler transform (via libbzip2). Libpolycomp can compress the timelines acquired by the Planck/LFI instrument with an overall compression ratio of ~9, while other widely known programs (gzip, bzip2) reach compression ratios less than 1.5.

  17. Investigating degassing dynamics into the shallow conduit through decompression experiments

    NASA Astrophysics Data System (ADS)

    Spina, Laura; Scheu, Bettina; Cimarelli, Corrado; Dingwell, Donald

    2014-05-01

    The history of bubbles' growth and interaction, as well as their spatial distribution in the shallow conduit, is deeply interconnected with the style of the eruptions. According to the fundamental role played by volatiles in the eruptive process, more effort is required in determining how the key factors of volcanic systems (i.e., magma properties, decompression rate) influence the dynamics of degassing. Therefore, our aim is to provide, through the analysis of decompression experiments on analogue materials, insights on such relations. We performed several decompression experiments with a shock-tube apparatus, and using silicon oil as laboratory-analogue for the magmatic melt. The sample was placed in a transparent autoclave, saturated with Argon for an established amount of time under a fixed pressure (up to a maximum of 10 MPa). Successively it was decompressed to atmospheric conditions, by releasing gas through a control valve. The dynamics of gas exsolution processes were recorded by using pressure sensors and a high speed camera. A range of viscosity values (1, 10, 100, 1000 Pa s) was investigated, for the same decompression path. Furthermore, some experiments were carried out with the addition of glass beads, as analogue to crystals, to the pure liquid. The height of the expanding column was monitored, in conjunction with images recorded during the experiments, and the growth rate of bubbles was measured at different times and depth. Finally, bubble size distribution has been evaluated at various stages for some experiments, in order to achieve a spatial map of the ongoing degassing phenomena. Results allowed us to define different regimes occurring during the decompression, whose features and characteristics are strongly affected by fluid viscosity. Indeed, several degassing phases were observed, from bubbly fluid to the eventual buildup of a more or less "foamy" phase, which ultimately experiences periodical oscillations around an average equilibrium level

  18. Decompression Sickness during Construction of the Dartford Tunnel

    PubMed Central

    Golding, F. Campbell; Griffiths, P.; Hempleman, H. V.; Paton, W. D. M.; Walder, D. N.

    1960-01-01

    A clinical, radiological and statistical survey has been made of decompression sickness during the construction of the Dartford Tunnel. Over a period of two years, 1,200 men were employed on eight-hour shifts at pressures up to 28 pounds per square inch (p.s.i.). There were 689 cases of decompression sickness out of 122,000 compressions, an incidence of 0·56%. The majority of cases (94·9%) were simple “bends”. The remainder (5·1%) exhibited signs and symptoms other than pain and were more serious. All cases were successfully treated and no fatality or permanent disability occurred. In two serious cases, cysts in the lungs were discovered. It is suggested that these gave rise to air embolism when the subjects were decompressed, and pulmonary changes may contribute more than hitherto believed to the pathogenesis of bends. Some other clinical features are described, including “skin-mottling” and an association between bends and the site of an injury. The bends rate is higher for the back shift (3 p.m. to 11 p.m.) and the night shift (11 p.m. to 7 a.m.) than for the day shift. In the treatment of decompression sickness it appears to be more satisfactory to use the minimum pressure required for relief of symptoms followed by slow decompression with occasional “soaks”, than to attempt to drive the causative bubbles into solution with high pressures. During the contract the decompression tables recently prescribed by the Ministry of Labour were used. Evidence was obtained that they could be made safer, and that the two main assumptions on which they are based (that sickness will not occur at pressures below 18 p.s.i., and that a man saturates in four hours) may be incorrect. It is desirable to test tables based on 15 p.s.i. and eight-hour saturation. The existence of acclimatization to pressure was confirmed; it is such that the bends rate may fall in two to three weeks to 0·1% of the incidence on the first day of exposure. Acclimatization is lost again

  19. Is carpal tunnel decompression warranted for HNPP?

    PubMed

    Earle, Nicholas; Zochodne, Douglas W

    2013-12-01

    The role of carpal tunnel decompression surgery for patients that have hereditary neuropathy with liability to pressure palsy (HNPP) is currently unknown. Since recovery from carpal tunnel compression is often associated with remyelination or nodal reconstruction rather than axonal regeneration, it is uncertain whether the PMP22 deletion associated with HNPP interrupts myelin or nodal reconstitution. We describe two patients with genetically confirmed HNPP and symptomatic carpal tunnel syndrome that had clinical and electrophysiological improvement after surgical decompression. The findings indicate a capacity for conduction repair in HNPP. They also suggest a need for further investigation and discussion around whether to offer carpal tunnel decompression to symptomatic HNPP patients.

  20. The phylogenetic history of Selaginellaceae based on DNA sequences from the plastid and nucleus: extreme substitution rates and rate heterogeneity.

    PubMed

    Korall, Petra; Kenrick, Paul

    2004-06-01

    Molecular phylogenetic research on Selaginellaceae has focused on the plastid gene rbcL, which in this family has unusually high substitution rates. Here we develop a molecular data set from the nuclear 26S ribosomal DNA gene with the aim of evaluating and extending the results of previous phylogenetic research. The 26S rDNA and the rbcL regions were sequenced for a sample of 23 species, which represent the main elements of species diversity in the family. The data were analysed independently and in combination using both maximum parsimony and Bayesian inference. Although several between genome differences were found, the general pattern of relationships uncovered by all analyses was very similar. Results corroborate the previous study supporting new groupings not previously recognised on morphological grounds. Substitution rates in the 26S rDNA were also found to be high (26% informative) for the region analysed, but lower than for rbcL (37% informative). These data indicate that high substitution rates might be widespread in all three genomes (i.e., plastid, mitochondrion, and nucleus).

  1. Extreme multi-millennial slip rate variations on the Garlock fault, California: geomorphology and geochronology of slip rate constraints

    NASA Astrophysics Data System (ADS)

    Rhodes, Edward; Dolan, James; McGill, Sally; McAuliffe, Lee; Zinke, Robert

    2016-04-01

    Combining existing paleoseismology with new geomorphic constraints for the same part of the Central Garlock fault in California, USA, allows us to demonstrate pronounced variations in slip rate during the Holocene for this left-lateral strike-slip system. Our results have basic implications for understanding how faults store and release strain energy in large earthquakes, and for Probabilistic Seismic Hazard Assessment (PSHA). A series of well-preserved fluvial terraces within alluvial fans provide offset markers, and newly developed single grain K-feldspar IRSL dating allows us to constrain depositional ages and subsequent erosion of terrace risers with good precision, using multiple samples from several different locations. This new dating approach has wide applicability for paleoseismology and slip rate studies, besides understanding environmental response to climatic events; agreement with independent age control provided by C-14 and Be-10 profiles comes from sites in the USA, Mexico, Tibet and Mongolia. Sediments dominated by a range of grain sizes from silt to boulders can be dated, and the technique is often applicable in locations where quartz OSL does not work well. We examine the interplay and coupling between climate and tectonics at millennial timescales, along with sedimentary and geomorphic responses, and consider how our understanding of fault dynamics can be improved with the benefit of these new approaches.

  2. Predictors of surgical revision after in situ decompression of the ulnar nerve.

    PubMed

    Krogue, Justin D; Aleem, Alexander W; Osei, Daniel A; Goldfarb, Charles A; Calfee, Ryan P

    2015-04-01

    This study was performed to identify factors associated with the need for revision surgery after in situ decompression of the ulnar nerve for cubital tunnel syndrome. This case-control investigation examined all patients treated at one institution with open in situ decompression for cubital tunnel syndrome between 2006 and 2011. The case patients were 44 failed decompressions that required revision, and the controls were 79 randomly selected patients treated with a single operation. Demographic data and disease-specific data were extracted from the medical records. The rate of revision surgery after in situ decompression was determined from our 5-year experience. A multivariate logistic regression model was used based on univariate testing to determine predictors of revision cubital tunnel surgery. Revision surgery was required in 19% (44 of 231) of all in situ decompressions performed during the study period. Predictors of revision surgery included a history of elbow fracture or dislocation (odds ratio [OR], 7.1) and McGowan stage I disease (OR, 3.2). Concurrent surgery with in situ decompression was protective against revision surgery (OR, 0.19). The rate of revision cubital tunnel surgery after in situ nerve decompression should be weighed against the benefits of a less invasive procedure compared with transposition. When considering in situ ulnar nerve decompression, prior elbow fracture as well as patients requesting surgery for mild clinically graded disease should be viewed as risk factors for revision surgery. Patient factors often considered relevant to surgical outcomes, including age, sex, body mass index, tobacco use, and diabetes status, were not associated with a greater likelihood of revision cubital tunnel surgery. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  3. Open carpal tunnel decompression by specialist versus nurse practitioner.

    PubMed

    Patel, Nimesh; Roberton, Andy; Batten, Timothy; Millyard, Cathy; Birdsall, Paul

    2015-12-01

    To compare the outcome after open carpal tunnel decompression by specialists versus a nurse practitioner. Of 1361 cases of open carpel tunnel decompression under local anaesthesia from 1996 to 2008, 807 were performed by specialists (consultant, specialist registrar, or specialty and associate specialist) and 554 by a nurse practitioner (since May 2006). The 2 groups were compared in terms of surgical time, total theatre time, postoperative pain, and patient satisfaction with the service. The mean surgical time was shorter in cases performed by specialists (13 vs. 18 minutes, p<0.0001), as was the mean total theatre time (26 vs. 29 minutes, p=0.0154). The rate of postoperative pain was higher in cases performed by specialists (31.5% vs. 24.5%, p=0.0125), as was the rate of patient dissatisfaction (1.6% vs. 0.18%, 0.0113). Nonetheless, since May 2006, outcome was comparable for specialists and the nurse practitioner. This could be due to the change from short-acting to long-acting/mixed local anaesthetic, and the technique for infiltration. The waiting time for surgery reduced from a mean of 16 to 3 weeks. Specialists and the nurse practitioner achieved comparable outcome after open carpal tunnel decompression.

  4. Crystal Nucleation and Growth in Mount Unzen Dacite Decompression Experiments

    NASA Astrophysics Data System (ADS)

    Almberg, L. D.; Larsen, J. F.; Eichelberger, J. C.

    2005-12-01

    Central to understanding eruption dynamics is the interplay of decompression and degassing, which triggers crystal nucleation and growth. Microlite and microphenocryst textures are an often-used tool to decipher the rates of magma ascent for specific eruptions. It is critical to determine the depth and time scale at which these processes take place to fully understand the system behavior. Conduit material retrieved from 1500 m depth from the USDP-4 at Mount Unzen, Japan provides a snap shot of a viscous magma en route to the surface and is a perfect counterpoint to compare with laboratory experiments under controlled P, T, and XH2O conditions. The core samples were identified as representing material from the 1991-1995 eruption based upon their elemental and isotopic composition and coincidence with a temperature maximum and alteration minimum (Nakada et al, ICDP Symposium, Potsdam, 2005). Three plagioclase crystal populations coexist in the spine emplaced at the conclusion of the eruption sequence in 1995, microlites (<20 μm), microphenocrysts (20-100 μm) and phenocrysts (>100 μm). Only phenocrysts and microlites are present in the samples extracted from 1500 m during drilling of the USDP-4 core. These textural differences are the focus of decompression experiments, with the purpose of replicating shallow level crystallization that may have occurred between 1500 m depth and the surface. It is possible that the microphenocrysts present in the dome lavas and absent in the conduit core could have formed at very shallow levels during magmatic ascent. Our experimental work delineates the role of decompression in controlling crystal size distributions in Unzen dacite, for comparison with the natural dome lavas and USDP-4 core samples. We conducted isothermal (870 ± 3°C) single and multi-step decompression experiments, equilibrated at 40 ± 3 MPa under water saturation and NNO conditions, and decompressed to 7.5 ± 0.5 MPa or 318 m depth. We ran such experiments for

  5. Extreme limestone weathering rates due to micron-scale grain detachment

    NASA Astrophysics Data System (ADS)

    Emmanuel, Simon; Levenson, Yael

    2014-05-01

    Chemical dissolution is often assumed to control the weathering rates of carbonate rocks, although some studies have indicated that mechanical erosion could also play a significant role. Quantifying the rates of the different processes is challenging due to the high degree of variability encountered in both field and lab settings. To measure the rates and mechanisms controlling long-term limestone weathering, we analyse a lidar scan of the Western Wall, a Roman period edifice located in Jerusalem. Surface retreat rates in fine-grained micritic limestone blocks are found to be as much as 2 orders of magnitude higher than the average rates estimated for coarse-grained limestone blocks at the same site. In addition, in experiments that use atomic force microscopy to image dissolving micritic limestone, we show that these elevated reaction rates could be due to rapid dissolution along micron-scale grain boundaries, followed by mechanical detachment of tiny particles from the surface. Our analysis indicates that micron-scale grain detachment, rather than pure chemical dissolution, could be the dominant erosional mode for fine-grained carbonate rocks.

  6. Hyperbaric chamber attendant safety I: Doppler analysis of decompression stress in multiplace chamber attendants.

    PubMed

    Cooper, P David; Van den Broek, Corry; Smart, David R; Nishi, Ron Y; Eastman, David

    2009-06-01

    Incidences of decompression sickness of 0.76% have been reported in hyperbaric attendants exposed to routine 243 kPa treatment tables. Occupational health risks of this magnitude are not acceptable in routine clinical practice. Significant variations in procedures are therefore found between institutions in an attempt to enhance staff safety. In extreme cases, the use of multiplace chambers has been abandoned. Doppler ultrasound provides an objective tool to assess the sub-clinical decompression stress associated with any particular exposure. To assess the decompression stress imposed upon staff exposed to our routine 243 kPa table and to elucidate demographic details within the attendant population that impact upon that stress. prospective observational cohort study. Profile: 243 kPa for 90 min with a 20 min decompression on oxygen. 28 nursing and medical personnel routinely undertaking patient care under hyperbaric conditions. Doppler assessment at 20 min intervals for up to 120 min post-exposure. Scoring: aural grading of intravascular bubbles using the Kisman-Masurel (K-M) scoring system; 163 exposures were scrutinized in this manner. 68% of exposures resulted in 'low' (K-M Grades 0-I), 22% in 'intermediate' (Grade II) and 10% in 'high' sub-clinical decompression stress (Grades III-IV). Female gender and increasing age, weight and exposure frequency showed trends towards higher bubble grades. There were no cases of clinical decompression sickness. Our standard 243 kPa table conforms to DCIEM definitions of 'acceptable' decompression stress (Grade II or fewer bubbles in ≥50% of the subjects). Significant inter- and intra-individual variability was evident even within this one, tightly controlled dive profile.

  7. Bone characteristics of late-term embryonic and hatchling broilers: bone development under extreme growth rate.

    PubMed

    Yair, R; Uni, Z; Shahar, R

    2012-10-01

    The development of broilers is an extreme example of rapid growth, increasing in weight from 40 g at hatch to 2,000 g 5 to 6 wk later. Such rapid growth requires a correspondingly fast development of the skeleton. Bone development is a genetically programmed process that is modified by epigenetic factors, mainly muscle-induced stresses and strains. In this study, we describe the temporal changes in bone morphology and material properties during the prehatch period [embryonic day (E) 14, E17, E19, E21] and posthatch d 3 and 7. The bones were examined for their weight, length, ash content, mechanical properties, and cortical structure. We show that the cross-sectional shape of the tibia and femur changes during the examination period from circular to elliptical. Additionally, the changes in bone properties are time-dependent and nonuniform: from E14 to E17 and from d 3 to 7, fast bone growth was noted, with major increases in both mechanical properties (stiffness, ultimate load, and energy to fracture) and geometric properties (cross-sectional area and thickness, medullary area, and moment of inertia). On the other hand, during the last days of incubation, most mechanical and geometric properties remain unchanged or even decrease. The reasons for this finding may relate to the hatching process but also to mineral shortage during the last days of incubation. This study leads to better understanding of bone development in ovo and posthatch in fast-growing broilers.

  8. Severe capillary leak syndrome after inner ear decompression sickness in a recreational scuba diver.

    PubMed

    Gempp, Emmanuel; Lacroix, Guillaume; Cournac, Jean-Marie; Louge, Pierre

    2013-07-01

    Post-decompression shock with plasma volume deficit is a very rare event that has been observed under extreme conditions of hypobaric and hyperbaric exposure in aviators and professional divers. We report a case of severe hypovolemic shock due to extravasation of plasma in a recreational scuba diver presenting with inner ear decompression sickness. Impaired endothelial function can lead to capillary leak with hemoconcentration and hypotension in severe cases. This report suggests that decompression-induced circulating bubbles may have triggered the endothelial damage, activating the classic inflammatory pathway of increased vascular permeability. This observation highlights the need for an accurate diagnosis of this potentially life-threatening condition at the initial presentation in the Emergency Department after a diving-related injury. An elevated hematocrit in a diver should raise the suspicion for the potential development of capillary leak syndrome requiring specific treatment using albumin infusion as primary fluid replacement. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Decompression models: review, relevance and validation capabilities.

    PubMed

    Hugon, J

    2014-01-01

    For more than a century, several types of mathematical models have been proposed to describe tissue desaturation mechanisms in order to limit decompression sickness. These models are statistically assessed by DCS cases, and, over time, have gradually included bubble formation biophysics. This paper proposes to review this evolution and discuss its limitations. This review is organized around the comparison of decompression model biophysical criteria and theoretical foundations. Then, the DCS-predictive capability was analyzed to assess whether it could be improved by combining different approaches. Most of the operational decompression models have a neo-Haldanian form. Nevertheless, bubble modeling has been gaining popularity, and the circulating bubble amount has become a major output. By merging both views, it seems possible to build a relevant global decompression model that intends to simulate bubble production while predicting DCS risks for all types of exposures and decompression profiles. A statistical approach combining both DCS and bubble detection databases has to be developed to calibrate a global decompression model. Doppler ultrasound and DCS data are essential: i. to make correlation and validation phases reliable; ii. to adjust biophysical criteria to fit at best the observed bubble kinetics; and iii. to build a relevant risk function.

  10. Auto-decompression system for engines

    SciTech Connect

    Onda, T.

    1988-12-13

    This patent describes a valve control device for an engine having a combustion chamber, a valve controlling communication with the chamber, a camshaft rotatably mounted in the engine, a valve motion cam fixed to the camshaft for rotation therewith, and a valve actuation mechanism including a cam follower engageable with the valve motion cam, the valve control device comprising: a decompression cam carried by the camshaft axially adjacent the valve motion cam, the decompression cam including a base circle portion defining an outer peripheral surface smaller in radial extent than the outer peripheral surface of the valve motion cam and having an inner bore to loosely encircle the camshaft; means for adjusting the position of the decomposition cam with respect to the camshaft between two locations including a first location on which the outer peripheral surface of the decompression cam extends radially outwardly from the axis of the camshaft to an extent greater than that of the valve motion cam to engage the cam follower for decompression operation of the valve, and a second location at which the outer peripheral surface of the decompression cam extends radially outwardly from the axis of the camshaft to an extent less than that of the valve motion cam whereby the valve motion cam engages the cam follower for normal operation of the valve; and means responsive to the rotational speed of the camshaft for automatically moving the decompression cam between the first and second locations.

  11. Pulsed dose-rate perioperative interstitial brachytherapy for soft tissue sarcomas of the extremities and skeletal muscles of the trunk.

    PubMed

    Lazzaro, Gianluca; Lazzari, Roberta; Pelosi, Giuseppe; De Pas, Tommaso; Mariani, Luigi; Mazzarol, Giovanni; Sances, Daniele; Tosti, Giulio; Baldini, Federica; Mosconi, Massimo; Tedeschi, Ines; Viale, Giuseppe; Marsiglia, Hugo; Chiappa, Antonio; Vavassori, Andrea; Orecchia, Roberto; Testori, Alessandro

    2005-11-01

    This study evaluated the role of pulsed dose-rate (PDR) brachytherapy (BRT), delivered alone or as a boost to external beam radiotherapy, as adjuvant therapy for the local control of soft tissue sarcomas of the extremities and skeletal muscles of the trunk that have undergone surgical treatment. Between July 1998 and January 2002, 42 patients were treated with a combination of surgery and BRT alone (18 patients) or BRT/external beam radiotherapy (24 patients) for the treatment of primary (n = 32) and recurrent (n = 10) soft tissue sarcomas located in the proximal extremity (n = 17), distal extremity (n = 17), and trunk (n = 8). Tumor size was <5 cm in 20 cases and >5 cm in 22 cases, with histological grading of 1 (n = 7), 2 (n = 18), or 3 (n = 17). The median BRT dose delivered was 15 Gy, and the median external beam irradiation dose was 50 Gy. With a median follow-up of 34 months, the 36-month survival was 83.9% (SE, 6.1%), and the local control was 89%. PDR interstitial BRT for soft tissue sarcoma is an effective, well-tolerated adjuvant radiation treatment that offers several practical advantages, among which are low acute and late toxicity with maximum normal tissue and critical structure sparing and overall shorter radiotherapy and hospital stay.

  12. Surgical Decompression in the Treatment of Diabetic Peripheral Neuropathy: A Systematic Review and Meta-analysis.

    PubMed

    Tu, Yiji; Lineaweaver, William Charles; Chen, Zenggan; Hu, Junda; Mullins, Fred; Zhang, Feng

    2017-03-01

    Background Over the last decade, surgical decompression procedures have been commonly used in the treatment of diabetic peripheral neuropathy. However, the effectiveness of them remains to be proved. Methods A comprehensive literature search of databases including PubMed-Medline, Ovid-EMBASE, and Cochrane Library was performed to collect the related literatures. The Medical Subject Headings used were "diabetic neuropathy," "surgical decompression," and "outcomes." The methodological index for nonrandomized studies was adopted for assessing the studies included in this review. Analyses were performed with Review Manager (Version 5.3, Copenhagen: The Nordic Cochrane Centre, the Cochrane Collaboration, 2014). Results A total of 12 literatures (including 8 prospective and 4 retrospective) encompassing 1,825 patients with DPN were included in the final analysis. Only one literature was identified as a randomized controlled trial. The remaining 11 literatures were observational studies; 7 of them were classified as upper-extremity nerve decompression group and 4 of them were classified as lower-extremity nerve decompression group. Meta-analysis shows that Boston questionnaire symptom severity and functional status of upper extremities, and distal motor latency and sensory conduction velocity of median nerve of DPN patients are significantly improved after carpal tunnel release. Besides, visual analog scale and two-point discrimination are considered clinically and statistically significant in lower extremities after operation. Conclusions The findings from our review have shown the efficacy of surgical decompression procedures in relieving the neurologic symptoms and restoring the sensory deficits in DPN patients. As there are few high-quality randomized controlled trials or well-designed prospective studies, more data are needed to elucidate the role of surgical procedures for DPN treatment in the future.

  13. Extremely High Magma Emplacement Rates Recorded in the Golden Horn Batholith, WA

    NASA Astrophysics Data System (ADS)

    Eddy, M. P.; Bowring, S. A.; Tepper, J. H.; Miller, R. B.

    2015-12-01

    High SiO2 rhyolites emplaced during 'super-eruptions' demonstrate that large volumes of eruptible magma can exist in the upper crust. However, the timescale over which the magma reservoirs that source these eruptions are built remains controversial. Thermal models suggest that magma emplacement rates need to be > 0.005-0.01 km3/yr in order to accumulate enough eruptible magma to source a 'super-eruption'. Yet, these rates are higher than the time-averaged rates (< 0.001 km3/yr) for nearly all well-studied granitoid plutonic complexes. This disparity contradicts geologic evidence suggesting that the high SiO2 rhyolites emplaced during 'super-eruptions' are extracted from crystal rich magma chambers that should be preserved in the geologic record as granodioritic and granitic plutons. We quantify time-averaged magma emplacement rates for the upper crustal Golden Horn batholith, WA based on new geologic mapping and U-Pb zircon CA-IDTIMS geochronology. The batholith is exposed over 310 km3 and can be separated in the field into five intrusive units. High topography allows the 3D geometry of each phase to be constrained and their volumes range from < 100 km3 to > 400 km3. U-Pb zircon geochronology reveals that four of the five phases were assembled incrementally and distinct zircon populations from samples within these phases suggest that individual magmatic pulses had fully crystallized before the next arrived. However, six nearly identical U-Pb zircon dates from a > 400 km3 rapakivi granite show that this phase was built in ca. 50 kyr and that large portions may have been emplaced nearly simultaneously. The implied emplacement rate for this phase (≥ 0.008 km3/yr) is in agreement with those predicted for assembly of the upper crustal magma chambers that source 'super-eruptions', and it may provide a rare and unprecedented opportunity to study the processes that occur in such chambers.

  14. Going to extremes: contrasting rates of diversification in a recent radiation of new world passerine birds.

    PubMed

    Barker, F Keith; Burns, Kevin J; Klicka, John; Lanyon, Scott M; Lovette, Irby J

    2013-03-01

    Recent analyses suggest that a few major shifts in diversification rate may be enough to explain most of the disparity in diversity among vertebrate lineages. At least one significant increase in diversification rate appears to have occurred within the birds; however, several nested lineages within birds have been identified as hyperdiverse by different studies. A clade containing the finches and relatives (within the avian order Passeriformes), including a large radiation endemic to the New World that comprises ~8% of all bird species, may be the true driver of this rate increase. Understanding the patterns and processes of diversification of this diverse lineage may go a long way toward explaining the apparently rapid diversification rates of both passerines and of birds as a whole. We present the first multilocus phylogenetic analyses of this endemic New World radiation of finch relatives that include sampling of all recognized genera, a relaxed molecular clock analysis of its divergence history, and an analysis of its broad-scale diversification patterns. These analyses recovered 5 major lineages traditionally recognized as avian families, but identified an additional 10 relatively ancient lineages worthy of recognition at the family level. Time-calibrated diversification analyses suggested that at least 3 of the 15 family-level lineages were significantly species poor given the entire group's background diversification rate, whereas at least one-the tanagers of family Thraupidae-appeared significantly more diverse. Lack of an age-diversity relationship within this clade suggests that, due to rapid initial speciation, it may have experienced density-dependent ecological limits on its overall diversity.

  15. Outcomes and safety of endoscopic tarsal tunnel decompression: a systematic review.

    PubMed

    Gkotsoulias, Efthymios N; Simonson, Devin C; Roukis, Thomas S

    2014-02-01

    Open surgical decompression of the tarsal tunnel is the standard surgical approach for compression of the tibial nerve within the tarsal tunnel. Complications associated with this approach can be significant and periods of non-weight bearing are required. An alternative approach allowing for minimal soft tissue trauma and reduced time to ambulation is therefore desirable. Endoscopic tarsal tunnel decompression may provide such an alternative. The authors performed a systematic review of electronic databases and other relevant sources to identify material regarding the safety of endoscopic tarsal tunnel decompression. Only articles that included clear information concerning the safety of endoscopic tarsal tunnel decompression with a follow-up of at least 12 months were included. Three studies were identified involving 37 feet, with a weighted mean follow-up of 27 months. There were no permanent complications relating to iatrogenic nerve injury, deep infection, or prolonged wound healing problems documented despite initiating ambulation within one week of surgery. Two patients (5.6%) developed recurrence more than 2 years postoperative and one (2.7%) showed no improvement. Endoscopic tarsal tunnel decompression is a safe procedure with a low rate of recurrence or failure and allows for near-immediate ambulation. However, additional prospective investigations comparing open and endoscopic approaches to tarsal tunnel decompression are warranted.

  16. Packing Vertex Data into Hardware-Decompressible Textures.

    PubMed

    Kwan, Kin Chung; Xu, Xuemiao; Wan, Liang; Wong, Tien-Tsin; Pang, Wai-Man

    2017-04-18

    Most graphics hardware features memory to store textures and vertex data for rendering. However, because of the irreversible trend of increasing complexity of scenes, rendering a scene can easily reach the limit of memory resources. Thus, vertex data are preferably compressed, with a requirement that they can be decompressed during rendering. In this paper, we present a novel method to exploit existing hardware texture compression circuits to facilitate the decompression of vertex data in graphics processing unit (GPUs). This built-in hardware allows real-time, random-order decoding of data. However, vertex data must be packed into textures, and careless packing arrangements can easily disrupt data coherence. Hence, we propose an optimization approach for the best vertex data permutation that minimizes compression error. All of these result in fast and high-quality vertex data decompression for real-time rendering. To further improve the visual quality, we introduce vertex clustering to reduce the dynamic range of data during quantization. Our experiments demonstrate the effectiveness of our method for various vertex data of 3D models during rendering with the advantages of a minimized memory footprint and high frame rate.

  17. Outcomes following surgical decompression for dysthyroid orbitopathy (Graves' disease).

    PubMed

    Leong, Samuel C; White, Paul S

    2010-02-01

    Graves' disease is a multiorgan autoimmune disease of complex pathophysiology that primarily affects the thyroid gland and orbit. The ophthalmic manifestations of Graves' disease may vary from mild proptosis which causes minimal cosmetic embarrassment to subluxation of the globe, exposure keratitis, corneal abrasion and even blindness. This article focuses on outcomes following orbital decompression. Surgical techniques have evolved with improved understanding of sinonasal anatomy and being technology-driven with the use of the fiberoptic endoscope and image guidance. The most common surgical outcome reported in the literature is reduction in proptosis, followed by visual acuity and intraocular pressure. Quality-of-life assessments are not routinely measured. There are a myriad of surgical techniques currently in practice which underscores the fact that no single technique is clearly superior to another. Endoscopic decompression results in a mean reduction of 3.50 mm and is associated with a low complication rate. Nevertheless, the literature suggests that the best techniques are likely to be multiwall approaches such as combined medial and lateral wall decompression. Management of dysthyroid ophthalmopathy is clearly multidisciplinary. Future studies should consider a minimum data set for reporting outcome measures which should include a quality of life tool.

  18. Emergency decompressive craniectomy after removal of convexity meningiomas

    PubMed Central

    Missori, Paolo; Domenicucci, Maurizio; Paolini, Sergio; Mancarella, Cristina; Tola, Serena; D’Elia, Alessandro; Marotta, Nicola; Seferi, Arsen; Esposito, Vincenzo

    2016-01-01

    Background: Convexity meningiomas are benign brain tumors that are amenable to complete surgical resection and are associated with a low complication rate. The aim of this study was to identify factors that result in acute postoperative neurological worsening after the removal of convexity meningiomas. Methods: Clinical evaluation and neuroradiological analysis of patients who underwent removal of a supratentorial convexity meningioma were reviewed. Patients were selected when their postoperative course was complicated by acute neurological deterioration requiring decompressive craniectomy. Results: Six patients (mean age: 43.3 years) underwent surgical removal of a supratentorial convexity meningioma. Brain shift (mean: 9.9 mm) was evident on preoperative imaging due to lesions of varying size and perilesional edema. At various times postoperatively, patient consciousness worsened (up to decerebrate posture) with contralateral paresis and pupillary anisocoria. Computed tomography revealed no postoperative hematoma, however, did indicate increased brain edema and ventricular shift (mean: 12 mm). Emergency decompressive craniectomy and brief ventilator assistance were performed in all patients. Ischemia of the ipsilateral posterior cerebral artery occurred in 3 patients and hydrocephalus occurred in 2 patients. Outcome was good in 2, fair in 2, 1 patient had severe disability, and 1 patient died after 8 months. Conclusions: Brain shift on preoperative imaging is a substantial risk factor for postoperative neurological worsening in young adult patients after the removal of convexity meningiomas. Emergency decompressive craniectomy must be considered because it is effective in most cases. Other than consciousness impairment, there is no reliable clinical landmark to guide the decision to perform decompressive craniectomy; however, brain ischemia may have already occurred. PMID:27857859

  19. Decompressive hemicraniectomy in supra-tentorial malignant infarcts

    PubMed Central

    Nizami, Furqan A.; Ramzan, Altaf U.; Wani, Abrar A.; Wani, Mushtaq A.; Malik, Nayil K.; Shah, Pervaiz A.; Asimi, Ravouf

    2012-01-01

    Background: Decompressive hemicraniectomy not only reduces the intracranial pressure but has been demonstrated to increase survival and decrease the morbidity in patients with supratentorial malignant brain infarcts (STMBI). The aim of this study was to assess the efficacy of surgical decompression to decrease the mortality and morbidity in patients with STMBI refractory to medical therapy and to compare the results with those of the medically managed patients. Methods: All the 24 consecutive patients with clinical and radiological diagnosis of STMBI, refractory to medical management in 2 years, were included. Option of surgical decompression after explaining the outcome, risk and benefits of the procedure was given to the attendants/relatives of all patients who were fulfilling the inclusion criteria. The patient group, whose attendants/relatives were not willing to undergo surgery, were subjected to the same medical therapy and they were taken as the “control group.” Results: Supratentorial malignant infarcts were more common in the age group of 41–60 years. Mean age of presentation was 42.16 ± 16.2 years and the mean GCS on admission was 7.83 ± 2.1. Mortality was 16.7% in the surgically and 25.0% in the medically managed group. Patients operated early (<48 h), age ≤60 years, midline shift <5 mm and size of infarct less than 2/3rd of the vascular territory involved showed good prognosis. The functional outcome revealed by modified Rankin Score (mRS) and Glasgow Outcome Score (GOS) was better in surgically managed patients. Results of the Zung Self-Rating Depression Score were better in surgically managed patients at 1 year. Barthal Index in the surgically managed group showed statistically significant results. Conclusions: Decompressive hemicraniectomy with duroplasty if performed early in STMBI not only decreases the mortality but also increases the functional outcome when compared with patients who were managed conservatively with medical therapy only

  20. On-the-Fly Decompression and Rendering of Multiresolution Terrain

    SciTech Connect

    Lindstrom, P; Cohen, J D

    2009-04-02

    We present a streaming geometry compression codec for multiresolution, uniformly-gridded, triangular terrain patches that supports very fast decompression. Our method is based on linear prediction and residual coding for lossless compression of the full-resolution data. As simplified patches on coarser levels in the hierarchy already incur some data loss, we optionally allow further quantization for more lossy compression. The quantization levels are adaptive on a per-patch basis, while still permitting seamless, adaptive tessellations of the terrain. Our geometry compression on such a hierarchy achieves compression ratios of 3:1 to 12:1. Our scheme is not only suitable for fast decompression on the CPU, but also for parallel decoding on the GPU with peak throughput over 2 billion triangles per second. Each terrain patch is independently decompressed on the fly from a variable-rate bitstream by a GPU geometry program with no branches or conditionals. Thus we can store the geometry compressed on the GPU, reducing storage and bandwidth requirements throughout the system. In our rendering approach, only compressed bitstreams and the decoded height values in the view-dependent 'cut' are explicitly stored on the GPU. Normal vectors are computed in a streaming fashion, and remaining geometry and texture coordinates, as well as mesh connectivity, are shared and re-used for all patches. We demonstrate and evaluate our algorithms on a small prototype system in which all compressed geometry fits in the GPU memory and decompression occurs on the fly every rendering frame without any cache maintenance.

  1. Wear characteristics of UHMW polyethylene: a method for accurately measuring extremely low wear rates.

    PubMed

    McKellop, H; Clarke, I C; Markolf, K L; Amstutz, H C

    1978-11-01

    The wear of UHMW polyethylene bearing against 316 stainless steel or cobalt chrome alloy was measured using a 12-channel wear tester especially developed for the evaluation of candidate materials for prosthetic joints. The coefficient of friction and wear rate was determined as a function of lubricant, contact stress, and metallic surface roughness in tests lasting two to three million cycles, the equivalent of several years' use of a prosthesis. Wear was determined from the weight loss of the polyethylene specimens corrected for the effect of fluid absorption. The friction and wear processes in blood serum differed markedly from those in saline solution or distilled water. Only serum lubrication produced wear surfaces resembling those observed on removed prostheses. The experimental method provided a very accurate reproducible measurement of polyethylene wear. The long-term wear rates were proportional to load and sliding distance and were much lower than expected from previously published data. Although the polyethylene wear rate increased with increasing surface roughness, wear was not severe except with very coarse metal surfaces. The data obtained in these studies forms a basis for the subsequent comparative evaluation of potentially superior materials for prosthetic joints.

  2. Effective Decompression of JPEG Document Images.

    PubMed

    Pham, The-Anh; Delalandre, Mathieu

    2016-08-01

    This paper concentrates on developing an effective approach for decompressing JPEG document images. Our main goal is targeted to time-critical applications, especially to those situated on mobile network infrastructures. To this aim, the proposed approach is designed to work either in the transform domain or image spatial plane. Specifically, the image blocks are first classified into smooth blocks (e.g., background and uniform regions) and non-smooth blocks (e.g., text, graphics, and line-drawings). Next, the smooth blocks are fully decoded in the transform domain by minimizing the total block boundary variation, which is very efficient to compute. For decoding non-smooth blocks, a novel text model is presented that accounts for the specifics of document content. In addition, an efficient optimization algorithm is introduced to reconstruct the non-smooth blocks. The proposed approach has been validated by extensive experiments, demonstrating a significant improvement of visual quality, assuming that document images have been encoded at low bit rates and thus are subject to severe distortion.

  3. Use of ultrasound in altitude decompression modeling

    NASA Technical Reports Server (NTRS)

    Olson, Robert M.; Pilmanis, Andrew A.

    1993-01-01

    A model that predicts the probability of developing decompression sickness (DCS) with various denitrogenation schedules is being developed by the Armstrong Laboratory, using human data from previous exposures. It was noted that refinements are needed to improve the accuracy and scope of the model. A commercially developed ultrasonic echo imaging system is being used in this model development. Using this technique, bubbles images from a subject at altitude can be seen in the gall bladder, hepatic veins, vena cava, and chambers of the heart. As judged by their motion and appearance in the vena cava, venous bubbles near the heart range in size from 30 to 300 M. The larger bubbles skim along the top, whereas the smaller ones appear as faint images near the bottom of the vessel. Images from growing bubbles in a model altitude chamber indicate that they grow rapidly, going from 20 to 100 M in 3 sec near 30,000 ft altitude. Information such as this is valuable in verifying those aspects of the DCS model dealing with bubble size, their growth rate, and their site of origin.

  4. Use of ultrasound in altitude decompression modeling

    NASA Technical Reports Server (NTRS)

    Olson, Robert M.; Pilmanis, Andrew A.

    1993-01-01

    A model that predicts the probability of developing decompression sickness (DCS) with various denitrogenation schedules is being developed by the Armstrong Laboratory, using human data from previous exposures. It was noted that refinements are needed to improve the accuracy and scope of the model. A commercially developed ultrasonic echo imaging system is being used in this model development. Using this technique, bubbles images from a subject at altitude can be seen in the gall bladder, hepatic veins, vena cava, and chambers of the heart. As judged by their motion and appearance in the vena cava, venous bubbles near the heart range in size from 30 to 300 M. The larger bubbles skim along the top, whereas the smaller ones appear as faint images near the bottom of the vessel. Images from growing bubbles in a model altitude chamber indicate that they grow rapidly, going from 20 to 100 M in 3 sec near 30,000 ft altitude. Information such as this is valuable in verifying those aspects of the DCS model dealing with bubble size, their growth rate, and their site of origin.

  5. Revealing rate-limiting steps in complex disease biology: The crucial importance of studying rare, extreme-phenotype families.

    PubMed

    Chakravarti, Aravinda; Turner, Tychele N

    2016-06-01

    The major challenge in complex disease genetics is to understand the fundamental features of this complexity and why functional alterations at multiple independent genes conspire to lead to an abnormal phenotype. We hypothesize that the various genes involved are all functionally united through gene regulatory networks (GRN), and that mutant phenotypes arise from the consequent perturbation of one or more rate-limiting steps that affect the function of the entire GRN. Understanding a complex phenotype thus entails unraveling the details of each GRN, namely, the transcription factors that bind to cis regulatory elements affected by sequence variants altering transcription of specific genes, and their mutual feedback relationships. These GRNs can be identified through their rate-limiting steps and are best uncovered by genomic analyses of rare, extreme phenotype families, thus providing a coherent molecular basis to complex traits and disorders. © 2016 WILEY Periodicals, Inc.

  6. The Effect of Sport Specialization on Lower Extremity Injury Rates in High School Athletes

    PubMed Central

    McGuine, Timothy A.; Bell, David; Brooks, Margaret Alison; Hetzel, Scott; Pfaller, Adam; Post, Eric

    2017-01-01

    Objectives: Sport specialization has been shown to be associated with increased risk of musculoskeletal lower extremity injuries (LEI) in adolescent athletes presenting in clinical settings. However, the association of sport specialization and incidence of LEI has not been studied prospectively in a large population of adolescent athletes. The objective of this study was to compare the incidence of LEI in high school athletes identified as having low (LOW), moderate (MOD) or high (HIGH) levels of sport specialization. Methods: Subjects (male and female, interscholastic athletes, grades 9 - 12) were recruited from a diverse sample of 29 Wisconsin high schools during the 2015/16 school year to participate in the study. Subjects d a questionnaire identifying all of the interscholastic and club sports they participated in during the previous and current school years, history of previous LEI, their primary sport and the number of primary sport competitions in which they participated in within the previous 12 months. Sport specialization status was determined using a previously published 3 item specialization scale (total score: 0 - 1 = LOW, 2 = MOD, 3 = HIGH). Athletic trainers at each school reported all athletic exposures and LEI that occurred for each subject during each interscholastic sport season they participated in during the school year. Analyses included group proportions, Odds Ratios (OR, [95%CI]) and median days lost due to injury (Med [IQR 25th,75th]. Multivariate Cox Proportional Hazards Ratios (HR, [95%CI]) were calculated to investigate the association between the incidence of LEI and sport specialization level while controlling for gender, grade, history of previous LEI, primary sport and the number of primary sport competitions. Results: A total of N =1,544 subjects (Female = 50%, Age =16.1+1.1 yrs.) enrolled in the study, competed in 2,843 athletic seasons and participated in 167,349 athletic exposures during the school year. Subjects were classified

  7. Acclimation to decompression sickness in rats.

    PubMed

    Montcalm-Smith, E A; McCarron, R M; Porter, W R; Lillo, R S; Thomas, J T; Auker, C R

    2010-03-01

    Protection against decompression sickness (DCS) by acclimation to hyperbaric decompression has been hypothesized but never proven. We exposed rats to acclimation dives followed by a stressful "test" dive to determine whether acclimation occurred. Experiments were divided into two phases. Phase 1 rats were exposed to daily acclimation dives of hyperbaric air for 30 min followed by rapid decompression on one of the following regimens: 70 ft of seawater (fsw) for 9 days (L70), 70 fsw for 4 days (S70), 40 fsw for 9 days (L40), 40 fsw for 4 days (S40), or unpressurized sham exposure for 9 days (Control). On the day following the last exposure, all were subjected to a "test" dive (175 fsw, 60 min, rapid decompression). Both L70 and S70 rats had significantly lower incidences of DCS than Control rats (36% and 41% vs. 62%, respectively). DCS incidences for the other regimens were lower than in Control rats but without statistical significance. Phase 2 used the most protective regimen from phase 1 (L70); rats were exposed to L70 or a similar regimen with a less stressful staged decompression. Another group was exposed to a single acclimation dive (70 fsw/30 min) on the day before the test dive. We observed a nonsignificant trend for the rapidly decompressed L70 dives to be more protective than staged decompression dives (44% vs. 51% DCS incidence). The single acclimation dive regimen did not provide protection. We conclude that protection against DCS can be attained with acclimating exposures that do not themselves cause DCS. The deeper acclimation dive regimens (70 fsw) provided the most protection.

  8. 181 Guidelines for the Management of Patients With Spinal Cord Injury: The Optimal Timing of Decompression.

    PubMed

    Wilson, Jefferson R; BSc, Lindsay Tetreault; Aarabi, Bizhan; Anderson, Paul A; Arnold, Paul M; Brodke, Darrel S; Burns, Anthony; Chen, Robert; Chiba, Kazuhiro; Dettori, Joseph; Furlan, Julio C; Harrop, James S; Holly, Langston T; Jeji, Tara; Kalsi-Ryan, Sukhvinder; Kotter, Mark; Kurpad, Shekar N; Kwon, Brian K; Marino, Ralph; Martin, Allen R; Massicotte, Eric M; Merli, Geno; Middleton, James; Nakashima, Hiroaki; Nagoshi, Narihito; Palmieri, Katherine; Shamji, Mohammed F; Singh, Anoushka; Skelly, Andrea; Yee, Albert; Fehlings, Michael

    2016-08-01

    The objective of this study is to develop guidelines that outline the optimal timing of decompression in patients with traumatic spinal cord injury (SCI) and central cord syndrome. A systematic review of the literature was conducted to address the following key questions: (1) What is the efficacy of early decompression (=24 hours) compared with late decompression (>24 hours) based on clinically important change in neurological status? (2) Does timing of decompression influence functional or administrative outcomes? (3) What is the safety profile of early decompression compared with late decompression? (4) What is the evidence that early decompression has differential efficacy or safety in subpopulations? (5) What is the comparative cost-effectiveness of early vs late decompression? A multidisciplinary guideline development group used this information, in combination with their clinical expertise, to develop recommendations for the optimal timing of SCI. The benefits and harms, financial impact, acceptability, feasibility, and patient preferences of each recommendation were carefully considered. The main conclusions from the systematic review included: (1) patients decompressed early were more likely to exhibit clinical improvement in neurological status at 6 months (cervical only) and at discharge from inpatient rehabilitation (all levels); (2) patients treated early for central cord syndrome achieved significantly greater improvements in neurological and functional status than those decompressed late; (3) there were no significant differences in length of acute care/rehabilitation stay or in rates of complications between treatment groups. Our recommendations included: "We suggest that early surgery be considered as a treatment option in adult patients with traumatic central cord syndrome" and "We suggest that early surgery be offered as an option for adult acute SCI patients regardless of level." These guidelines should be implemented into clinical practice to

  9. Prediction of decompression illness using bubble models.

    PubMed

    Tikuisis, P; Gault, K A; Nishi, R Y

    1994-06-01

    The method of maximum likelihood was applied to models of bubble formation and evolution against data involving decompression illness (DCI). Equilibrium and non-equilibrium gas kinetic models were tested under the constraint of a finite tissue volume. The equilibrium model (leq), where the internal gas of a bubble is in partial pressure and mechanical equilibrium with the gas dissolved in tissue, assumed formation of a bubble upon any gas supersaturation. The non-equilibrium model (neq), where mechanical equilibrium is maintained but the exchange of gas between the bubble and the tissue is governed by a rate constant, assumed formation of a bubble at the metastable equilibrium state which requires a specific degree of gas supersaturation. In addition, another version of bubble evolution based on the diffusivity of gas in tissue (vl) was tested under similar finite volume constraints. Model parameters included liquid surface tension, the gas exchange rate constant, gas solubility, and the tissue time constant. The risk of DCI was based on the bubble radius (R) raised to powers ranging from 0 to 6. The data included 2,023 man-dives in 630 different dive profiles of air and nitrox gas mixtures with depth ranging from 1.75 to 7.09 bar and bottom time ranging from 2.8 to 300.2 min. There were 97 occurrences of DCI and 27 occurrences of marginal symptoms. Predictions of the neq and vl models were quite similar and suggested that the tissue primarily responsible for bubble formation leading to DCI in the present analysis has a perfusion rate of about 4.0 ml blood.100 ml-1.min-1. The best fit of the data for a single compartment of 10(-4) ml vol was obtained with the leq model and a risk based on R4, and an estimated time constant of 95.6 +/- 9.8 min.

  10. Extremely low-frame-rate digital fluoroscopy in catheter ablation of atrial fibrillation

    PubMed Central

    Lee, Ji Hyun; Kim, Jun; Kim, Minsu; Hwang, Jongmin; Hwang, You Mi; Kang, Joon-Won; Nam, Gi-Byoung; Choi, Kee-Joon; Kim, You-Ho

    2017-01-01

    Abstract Despite the technological advance in 3-dimensional (3D) mapping, radiation exposure during catheter ablation of atrial fibrillation (AF) continues to be a major concern in both patients and physicians. Previous studies reported substantial radiation exposure (7369–8690 cGy cm2) during AF catheter ablation with fluoroscopic settings of 7.5 frames per second (FPS) under 3D mapping system guidance. We evaluated the efficacy and safety of a low-frame-rate fluoroscopy protocol for catheter ablation for AF. Retrospective analysis of data on 133 patients who underwent AF catheter ablation with 3-D electro-anatomic mapping at our institute from January 2014 to May 2015 was performed. Since January 2014, fluoroscopy frame rate of 4-FPS was implemented at our institute, which was further decreased to 2-FPS in September 2014. We compared the radiation exposure quantified as dose area product (DAP) and effective dose (ED) between the 4-FPS (n = 57) and 2-FPS (n = 76) groups. The 4-FPS group showed higher median DAP (599.9 cGy cm2; interquartile range [IR], 371.4–1337.5 cGy cm2 vs. 392.0 cGy cm2; IR, 289.7–591.4 cGy cm2; P < .01), longer median fluoroscopic time (24.4 min; IR, 17.5–34.9 min vs. 15.1 min; IR, 10.7–20.1 min; P < .01), and higher median ED (1.1 mSv; IR, 0.7–2.5 mSv vs. 0.7 mSv; IR, 0.6–1.1 mSv; P < .01) compared with the 2-FPS group. No major procedure-related complications such as cardiac tamponade were observed in either group. Over follow-up durations of 331 ± 197 days, atrial tachyarrhythmia recurred in 20 patients (35.1%) in the 4-FPS group and in 27 patients (35.5%) in the 2-FPS group (P = .96). Kaplan–Meier survival analysis revealed no significant different between the 2 groups (log rank, P = .25). In conclusion, both the 4-FPS and 2-FPS settings were feasible and emitted a relatively low level of radiation compared with that historically reported for DAP in a conventional

  11. Threading polyintercalators with extremely slow dissociation rates and extended DNA binding sites

    PubMed Central

    Smith, Amy Rhoden; Iverson, Brent L.

    2013-01-01

    The development of small molecules that bind DNA sequence specifically has the potential to modulate gene expression in a general way. One mode of DNA binding is intercalation, or the insertion of molecules between DNA base pairs. We have developed a modular polyintercalation system in which intercalating naphthalene diimide (NDI) units are connected by flexible linkers that alternate between the minor and major grooves of DNA when bound. We recently reported a threading tetraintercalator with a dissociation half-life of 16 days, the longest reported to date, from its preferred 14 bp binding site. Herein, three new tetraintercalator derivatives were synthesized with one, two, and three additional methylene units in the central major groove-binding linker. These molecules displayed dissociation half-lives of 57, 27, and 18 days, respectively, from the 14 bp site. The optimal major groove-binding linker was used in the design of an NDI hexaintercalator that was analyzed by gel-shift assays, DNase I footprinting, and UV-visible spectroscopy. The hexaintercalator bound its entire 22 bp binding site, the longest reported specific binding site for a synthetic, non-nucleic acid based DNA binding molecule, but with a significantly faster dissociation rate compared to the tetraintercalators. PMID:23919778

  12. Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands.

    PubMed

    Dalcin Martins, Paula; Hoyt, David W; Bansal, Sheel; Mills, Christopher T; Tfaily, Malak; Tangen, Brian A; Finocchiaro, Raymond G; Johnston, Michael D; McAdams, Brandon C; Solensky, Matthew J; Smith, Garrett J; Chin, Yu-Ping; Wilkins, Michael J

    2017-08-01

    Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions. © 2017 John Wiley & Sons Ltd.

  13. Abundant carbon substrates drive extremely high sulfate reduction rates and methane fluxes in Prairie Pothole Wetlands

    USGS Publications Warehouse

    Martins, Paula; Hoyt, David W.; Bansal, Sheel; Mills, Christopher; Tfaily, Malak; Tangen, Brian; Finocchiaro, Raymond; Johnston, Michael D.; McAdams, Brandon C.; Solensky, Matthew J.; Smith, Garrett J.; Chin, Yu-Ping; Wilkins, Michael J.

    2017-01-01

    Inland waters are increasingly recognized as critical sites of methane emissions to the atmosphere, but the biogeochemical reactions driving such fluxes are less well understood. The Prairie Pothole Region (PPR) of North America is one of the largest wetland complexes in the world, containing millions of small, shallow wetlands. The sediment pore waters of PPR wetlands contain some of the highest concentrations of dissolved organic carbon (DOC) and sulfur species ever recorded in terrestrial aquatic environments. Using a suite of geochemical and microbiological analyses, we measured the impact of sedimentary carbon and sulfur transformations in these wetlands on methane fluxes to the atmosphere. This research represents the first study of coupled geochemistry and microbiology within the PPR and demonstrates how the conversion of abundant labile DOC pools into methane results in some of the highest fluxes of this greenhouse gas to the atmosphere ever reported. Abundant DOC and sulfate additionally supported some of the highest sulfate reduction rates ever measured in terrestrial aquatic environments, which we infer to account for a large fraction of carbon mineralization in this system. Methane accumulations in zones of active sulfate reduction may be due to either the transport of free methane gas from deeper locations or the co-occurrence of methanogenesis and sulfate reduction. If both respiratory processes are concurrent, any competitive inhibition of methanogenesis by sulfate-reducing bacteria may be lessened by the presence of large labile DOC pools that yield noncompetitive substrates such as methanol. Our results reveal some of the underlying mechanisms that make PPR wetlands biogeochemical hotspots, which ultimately leads to their critical, but poorly recognized role in regional greenhouse gas emissions.

  14. The impact of gender, level of amputation and diabetes on prosthetic fit rates following major lower extremity amputation

    PubMed Central

    Davie-Smith, Fiona; Paul, Lorna; Nicholls, Natalie; Stuart, Wesley P; Kennon, Brian

    2016-01-01

    Background: Diabetes mellitus is a leading cause of major lower extremity amputation. Objective: To examine the influence of gender, level of amputation and diabetes mellitus status on being fit with a prosthetic limb following lower extremity amputation for peripheral arterial disease. Study design: Retrospective analysis of the Scottish Physiotherapy Amputee Research Group dataset. Results: Within the cohort with peripheral arterial disease (n = 1735), 64% were men (n = 1112) and 48% (n = 834) had diabetes mellitus. Those with diabetes mellitus were younger than those without: mean 67.5 and 71.1 years, respectively (p < 0.001). Trans-tibial amputation:trans-femoral amputation ratio was 2.33 in those with diabetes mellitus, and 0.93 in those without. A total of 41% of those with diabetes mellitus were successfully fit with a prosthetic limb compared to 38% of those without diabetes mellitus. Male gender positively predicted fitting with a prosthetic limb at both trans-tibial amputation (p = 0.001) and trans-femoral amputation (p = 0.001) levels. Bilateral amputations and increasing age were negative predictors of fitting with a prosthetic limb (p < 0.001). Diabetes mellitus negatively predicted fitting with a prosthetic limb at trans-femoral amputation level (p < 0.001). Mortality was 17% for the cohort, 22% when the amputation was at trans-femoral amputation level. Conclusion: Of those with lower extremity amputation as a result of peripheral arterial disease, those with diabetes mellitus were younger, and more had trans-tibial amputation. Although both age and amputation level are good predictors of fitting with a prosthetic limb, successful limb fit rates were no better than those without diabetes mellitus. Clinical relevance This is of clinical relevance to those who are involved in the decision-making process of prosthetic fitting following major amputation for dysvascular and diabetes aetiologies. PMID:26850990

  15. The impact of gender, level of amputation and diabetes on prosthetic fit rates following major lower extremity amputation.

    PubMed

    Davie-Smith, Fiona; Paul, Lorna; Nicholls, Natalie; Stuart, Wesley P; Kennon, Brian

    2017-02-01

    Diabetes mellitus is a leading cause of major lower extremity amputation. To examine the influence of gender, level of amputation and diabetes mellitus status on being fit with a prosthetic limb following lower extremity amputation for peripheral arterial disease. Retrospective analysis of the Scottish Physiotherapy Amputee Research Group dataset. Within the cohort with peripheral arterial disease ( n = 1735), 64% were men ( n = 1112) and 48% ( n = 834) had diabetes mellitus. Those with diabetes mellitus were younger than those without: mean 67.5 and 71.1 years, respectively ( p < 0.001). Trans-tibial amputation:trans-femoral amputation ratio was 2.33 in those with diabetes mellitus, and 0.93 in those without. A total of 41% of those with diabetes mellitus were successfully fit with a prosthetic limb compared to 38% of those without diabetes mellitus. Male gender positively predicted fitting with a prosthetic limb at both trans-tibial amputation ( p = 0.001) and trans-femoral amputation ( p = 0.001) levels. Bilateral amputations and increasing age were negative predictors of fitting with a prosthetic limb ( p < 0.001). Diabetes mellitus negatively predicted fitting with a prosthetic limb at trans-femoral amputation level ( p < 0.001). Mortality was 17% for the cohort, 22% when the amputation was at trans-femoral amputation level. Of those with lower extremity amputation as a result of peripheral arterial disease, those with diabetes mellitus were younger, and more had trans-tibial amputation. Although both age and amputation level are good predictors of fitting with a prosthetic limb, successful limb fit rates were no better than those without diabetes mellitus. Clinical relevance This is of clinical relevance to those who are involved in the decision-making process of prosthetic fitting following major amputation for dysvascular and diabetes aetiologies.

  16. Extreme soil erosion rates in citrus slope plantations and control strategies. A literature review

    NASA Astrophysics Data System (ADS)

    Cerdà, Artemi; Ángel González Peñaloza, Félix; Pereira, Paulo; Reyes Ruiz Gallardo, José; García Orenes, Fuensanta; Burguet, María

    2013-04-01

    Soil Erosion is a natural process that shapes the Earth. Due to the impact of agriculture, soil erosion rates increase, landforms show gullies and rills, and soils are depleted. In the Mediterranean, wheat, olive and vineyards were the main agriculture products, but new plantations are being found in sloping terrain due to the drip-irrigation. This new strategy results in the removal of the traditional terraces in order to make suitable for mechanization the agriculture plantation. Citrus is a clear example of the impact of the new chemical agriculture with a high investment in herbicides, pesticides, mechanisation, land levelling and drip computer controlled irrigation systems. The new plantation of citrus orchards is found in the Mediterranean, but also in California, Florida, China and Brazil. Chile, Argentina, and South Africa are other producers that are moving to an industrial production of citrus. This paper shows how the citrus plantations are found as one of the most aggressive plantation due to the increase in soil erosion, and how we can apply successful control strategies. The research into the high erosion rates of citrus orchard built on the slopes are mainly found in China (Wu et al., 1997; Xu et al., 2010; Wang et al., 2011; Wu et al., 2011; Liu et al., 2011; Lü et al., 2011; Xu et al., 2012) and in the Mediterranean (Cerdà and Jurgensen, 2008; 2009; Cerdà et al., 2009a; 2009b; Cerdà et al., 2011; 2012) Most of the research done devoted to the measurements of the soil losses but also some research is done related to the soil properties (Lu et al., 1997; Lü et al., 2012; Xu et al., 2012) and the impact of cover crops to reduce the soil losses (Lavigne et al., 2012; Le Bellec et al., 2012) and the use of residues such as dried citrus peel in order to reduce the soil losses. There are 116 million tonnes of citrus produced yearly, and this affects a large surface of the best land. The citrus orchards are moving from flood irrigated to drip

  17. The mechanics of decompressive craniectomy: Bulging in idealized geometries

    NASA Astrophysics Data System (ADS)

    Weickenmeier, Johannes; Kuhl, Ellen; Goriely, Alain

    2016-11-01

    In extreme cases of traumatic brain injury or a stroke, the resulting uncontrollable swelling of the brain may lead to a harmful increase of the intracranial pressure. As a common measure for immediate release of pressure on the brain, part of the skull is surgically removed allowing for the brain to bulge outwards, a procedure known as a decompressive craniectomy. During this excessive brain swelling, the affected tissue typically undergoes large deformations resulting in a complex three-dimensional mechanical loading state with several important implications on optimal treatment strategies and outcome. Here, as a first step towards a better understanding of the mechanics of a decompressive craniectomy, we consider simple models for the bulging of elastic solids under geometric constraints representative of the surgical intervention. In small deformations and simple geometries, the exact solution of this problem is derived from the theory of contact mechanics. The analysis of these solutions reveals a number of interesting generic features relevant for the mechanics of craniectomy.

  18. Decompressive Surgery in a Patient with Posttraumatic Syringomyelia

    PubMed Central

    Byun, Min Seok; Hwang, Yong Soon; Park, Sang Keun

    2010-01-01

    Posttraumatic syringomyelia may result from a variety of inherent conditions and traumatic events, or from some combination of these. Many hypotheses have arisen to explain this complex disorder, but no consensus has emerged. A 28-year-old man presented with progressive lower extremity weakness, spasticity, and decreased sensation below the T4 dermatome five years after an initial trauma. Magnetic resonance imaging (MRI) revealed a large, multi-septate syrinx cavity extending from C5 to L1, with a retropulsed bony fragment of L2. We performed an L2 corpectomy, L1-L3 interbody fusion using a mesh cage and screw fixation, and a wide decompression and release of the ventral portion of the spinal cord with an operating microscope. The patient showed complete resolution of his neurological symptoms, including the bilateral leg weakness and dysesthesia. Postoperative MRI confirmed the collapse of the syrinx and restoration of subarachnoid cerebrospinal fluid (CSF) flow. These findings indicate a good correlation between syrinx collapse and symptomatic improvement. This case showed that syringomyelia may develop through obstruction of the subarachnoid CSF space by a bony fracture and kyphotic deformity. Ventral decompression of the obstructed subarachnoid space, with restoration of spinal alignment, effectively treated the spinal canal encroachment and post-traumatic syringomyelia. PMID:20379479

  19. The U.S. Navy decompression computer.

    PubMed

    Butler, F K; Southerland, D

    2001-01-01

    The U.S. Navy has recently approved the Cochran NAVY decompression computer (DC) for use in Naval Special Warfare diving. This action represents the first approval of a diver-worn DC for use in the U.S. Navy. This paper reviews the development and testing of both the decompression algorithm and the hardware chosen for the Navy's DC. The decompression software in the Cochran NAVY is the VVAL 18 algorithm developed at the Navy Experimental Diving Unit (NEDU) by Captain Ed Thalmann. A discussion of the relative conservatism of the VVAL18 algorithm in comparison to the U.S. Navy Standard Air Tables and the basis for the differences between the two is provided. The initial guidelines establishing DC diving practice for the Navy SEAL community are outlined as are plans for future research efforts in U.S. Navy DC diving.

  20. Age, weight and decompression sickness in rats.

    PubMed

    Buzzacott, Peter; Theron, Michael; Mazur, Aleksandra; Wang, Qiong; Lambrechts, Kate; Eftedal, Ingrid; Ardestani, Simin Berenji; Guerrero, François

    2016-01-01

    The aim of this study was to determine if, after controlling for weight, age is associated with decompression sickness (DCS) in rats. Following compression-decompression, male rats aged 11 weeks were observed for DCS. After two weeks recovery, surviving rats were re-dived using the same compression-decompression profile. In this experiment, there was a clear difference between DCS outcome at ages 11 or 13 weeks in matched rats (p = 0.002). Even with weight included in the model, age was significantly associated with DCS (p = 0.01), yet after removal of weight the association was much stronger (p = 0.002). We believe that age is likely to be found associated with the probability of DCS in a larger dataset with a wider range of parameters, after accounting for the effect of weight.

  1. ALMACAL II: Extreme Star Formation Rate Densities in Dusty Starbursts Revealed by ALMA 20 mas Resolution Imaging

    NASA Astrophysics Data System (ADS)

    Oteo, I.; Zwaan, M. A.; Ivison, R. J.; Smail, I.; Biggs, A. D.

    2017-03-01

    We present ultrahigh spatial resolution (∼20 mas or 150 pc) ALMA observations of the dust continuum at 920 μm and 1.2 mm in two submillimeter sources at z = 3.442, ALMACAL–1 (A–1: {S}870μ {{m}}=6.5+/- 0.2 {mJy}) and ALMACAL–2 (A–2: {S}870μ {{m}}=4.4+/- 0.2 {mJy}). About half of the star formation in each of these sources is dominated by a single compact clump (FWHM size of ∼350 pc). In A–1, two additional fainter clumps are found. The star formation rate (SFR) surface densities of all these clumps are extremely high, {{{Σ }}}{SFR}∼ 1200 to ∼ 3000 {M}ȯ {{yr}}-1 {{kpc}}-2, the highest rates found in high-redshift galaxies. Given their geometry and identical redshifts, there is a possibility that A–1 and A–2 are the lensed images of a single background source that are gravitationally amplified by the blazar host. If this were the case, the effective radius of the dusty galaxy in the source plane would be {R}{eff}∼ 40 {pc} and the demagnified SFR surface density would be {{{Σ }}}{SFR} ∼ 10,000 {M}ȯ {{yr}}-1 {{kpc}}-2, comparable with the eastern nucleus of Arp 220. Although we cannot rule out an AGN contribution, our results suggest that a significant percentage of the enormous far-IR luminosity in some dusty starbursts is extremely compact. The high {{{Σ }}}{SFR} in these sources could only be measured thanks to the ultrahigh-resolution ALMA observations used in this work, demonstrating that long-baseline observations are essential to study and interpret the properties of dusty starbursts in the early Universe.

  2. Evidence Report: Risk of Decompression Sickness (DCS)

    NASA Technical Reports Server (NTRS)

    Conkin, Johnny; Norcross, Jason R.; Wessel, James H. III; Abercromby, Andrew F. J.; Klein, Jill S.; Dervay, Joseph P.; Gernhardt, Michael L.

    2013-01-01

    The Risk of Decompression Sickness (DCS) is identified by the NASA Human Research Program (HRP) as a recognized risk to human health and performance in space, as defined in the HRP Program Requirements Document (PRD). This Evidence Report provides a summary of the evidence that has been used to identify and characterize this risk. Given that tissue inert gas partial pressure is often greater than ambient pressure during phases of a mission, primarily during extravehicular activity (EVA), there is a possibility that decompression sickness may occur.

  3. Outcomes of surgical paraclavicular thoracic outlet decompression.

    PubMed

    Desai, Sapan S; Toliyat, Mohammad; Dua, Anahita; Charlton-Ouw, Kristofer M; Hossain, Monir; Estrera, Anthony L; Safi, Hazim J; Azizzadeh, Ali

    2014-02-01

    Thoracic outlet syndrome (TOS) is a constellation of signs and symptoms caused by compression of the neurovascular structures in the thoracic outlet. These structures include the brachial plexus, the subclavian vein, and the subclavian artery, resulting in neurogenic (NTOS), venous (VTOS), and arterial (ATOS) types of TOS, respectively. The purpose of this study was to evaluate the outcomes of paraclavicular surgical decompression for TOS. A prospective analysis of patients who underwent surgical decompression for TOS at a newly established center was performed. Diagnosis of TOS was based on clinical history, a physical examination, and additional diagnostic studies. The indication for surgery in patients diagnosed with NTOS was the presence of persistent symptoms after a trial of physical therapy. Primary outcomes were assessed according to Derkash's classification as excellent, good, fair, and poor. Secondary outcomes included mortality, complications, and duration of hospital stay. Between August 2004 and June 2011, 40 paraclavicular decompression procedures were performed on 36 patients (16 men) with TOS. The mean age was 36.5 years (range: 15-68). Bilateral decompression was performed on 4 patients. The types were NTOS (n = 19; 48%), VTOS (n = 16; 40%), and ATOS (n = 5; 12%). In addition to pain, the most common presenting symptom was numbness in NTOS, swelling in VTOS, and coolness in ATOS. A history of trauma was present in 22.2%. Two patients suffered from recurrent symptoms after previous transaxillary first rib resection for VTOS at another institution. Diagnostic tests performed included nerve conduction studies (43%), venogram (40%), and arteriogram (20%). All patients underwent paraclavicular decompression, which included radical anterior and partial middle scalenectomy, brachial plexus neurolysis, and first rib resection. The first rib resection was partial, through a supraclavicular only approach in NTOS and ATOS patients (60%) or complete, through a

  4. Orbital decompression for severe dysthyroid eye disease.

    PubMed Central

    Fells, P

    1987-01-01

    Current methods of medical treatment of this difficult condition are briefly reviewed, with comments on the generally unsatisfactory response. Attention is therefore directed to surgical methods and a short history given of the various routes used for orbital decompression. The author's own results of transantral, and more recently ethmoidal, decompression are given, with a detailed description of the technique for the latter approach. An interesting frequent consequence of postoperative A pattern to the ocular movements is discussed in the light of Koornneef's concept of orbital fascial anatomy, and suggestions are made for its avoidance. Images PMID:3828262

  5. Prophylactic nasogastric decompression after emergency laparotomy.

    PubMed

    Sapkota, Ranjan; Bhandari, Ramesh Singh

    2013-01-01

    Post-operative nasogastric intubation after emergency laparotomy is a common practice in many centers, with the intent of hastening the return of bowel function, relieving gastrointestinal discomfort, reducing various post-operative complications and reducing hospital stay. However, bowel rest and gastric decompression have been re-examined in the light of more recent data. Many studies and meta-analyses over the last 50 years have challenged the routine use of nasogastric tubes after laparotomy. The objective of this study is to evaluate the need for routine nasogastric decompression after emergency laparotomy. A prospective, randomized controlled trial was conducted for 12 months (May 1, 2007 to Apr 30, 2008) in the Department of Surgery, Tribhuvan University Teaching Hospital, after ethical approval. Patients were enrolled as per criteria (Box 1), and subsequently allocated by simple randomization into two groups: Group 1 and Group 2. Patients undergoing emergency laparotomy for perforation peritonitis, intestinal obstruction and abdominal trauma were randomized to two groups - with or without nasogastric tube after surgery. Gastric upset, return of bowel function and postoperative complications were compared. Total of 115 patients met the inclusion criteria. There was no statistically significant difference in the occurrence of gastric upset (P: 0.38), wound complications (P: 0.30), respiratory complications (P: 0.30) and anastomotic leak (P: 0.64) between two groups. Bowel function returned in comparable times in both groups (correlation coefficient: 0.14; P: 0.54). Nasogastric tube had to be reinserted in three patients in the group with nasogastric decompression postoperatively, and four in the group without (P: 0.43). Thus, routine nasogastric decompression neither prevented the development of gastrointestinal discomfort nor precluded the need for tube replacement once it was discontinued. For every patient who required post-operative nasogastric

  6. Hypobaric decompression prebreathe requirements and breathing environment

    NASA Technical Reports Server (NTRS)

    Webb, James T.; Pilmanis, Andrew A.

    1993-01-01

    To reduce incidence of decompression sickness (DCS), prebreathing 100 percent oxygen to denitrogenate is required prior to hypobaric decompressions from a sea level pressure breathing environment to pressures lower than 350 mm Hg (20,000 ft; 6.8 psia). The tissue ratio (TR) of such exposures equals or exceeds 1.7; TR being the tissue nitrogen pressure prior to decompression divided by the total pressure after decompression (((0.781)(14.697))/6.758). Designing pressure suits capable of greater pressure differentials, lower TR's, and procedures which limit the potential for DCS occurrence would enhance operational efficiency. The current 10.2 psia stage decompression prior to extravehicular activity (EVA) from the Shuttle in the 100 percent oxygen, 4.3 psia suit, results in a TR of 1.65 and has proven to be relatively free of DCS. Our recent study of zero-prebreathe decompressions to 6.8 psia breathing 100 percent oxygen (TR = 1.66) also resulted in no DCS (N = 10). The level of severe, Spencer Grades 3 or 4, venous gas emboli (VGE) increased from 0 percent at 9.5 psia to 40 percent at 6.8 psia yielding a Probit curve of VGE risk for the 51 male subjects who participated in these recent studies. Earlier, analogous decompressions using a 50 percent oxygen, 50 percent nitrogen breathing mixture resulted in one case of DCS and significantly higher levels of severe VGE, e.g., at 7.8 psia, the mixed gas breathing environment resulted in a 56 percent incidence of severe VGE versus 10 percent with use of 100 percent oxygen. The report of this study recommended use of 100 percent oxygen during zero-prebreathe exposure to 6.8 psia if such a suit could be developed. For future, long-term missions, we suggest study of the effects of decompression over several days to a breathing environment of 150 mmHg O2 and approximately 52 mmHg He as a means of eliminating DCS and VGE hazards during subsequent excursions. Once physiologically adapted to a 4 psia vehicle, base, or space

  7. Decompression-Induced Crystallization of Hydrous Basalt

    NASA Astrophysics Data System (ADS)

    Teasdale, R.; Brooker, R. A.

    2014-12-01

    Decompression-induced crystallization of hydrous basalt during magma ascent from 1.5 kb (150 MPa) is quantified using isothermal decompression TZM experiments. The starting composition is a synthetic glass based on the 1921 Kilauea basalt, with 1% H2O added. In all cases, the liquidus phase is aluminous spinel, followed by clinopyroxene, then plagioclase. The plagioclase liquidus temperatures for isobaric (equilibrium) experiments range from 1175°C (at 1.5 kb) to 1217°C (at 200b), which are 35-75°C hotter than predicted by MELTS (Ghiorso & Sack 1995). Experiments were decompressed at 1kb/hr and quenched at 800, 400, 200, or 100b for three temperatures (1160°, 1150°, and 1140°C). Plagioclase crystals formed during decompression have long axes that range from less than 1 micron to 20 microns. Increasing decompression yields larger plagioclase crystal sizes and aspect ratios for experiments at equal temperatures. However, the number of crystals does not vary systematically, indicating that crystallization is dominated by growth rather than nucleation during decompression. Plagioclase compositions for experiments were measured with University of Bristol's Electron Microprobe and the Hyperprobe with Field Emission Gun. Plagioclase compositions from equilibrium experiments (An60-An80) span the range of those from decompression experiments (An60-An73). Equilibrium experiments generated higher An compositions at lower pressures (500b) than at higher pressure (1.5kb) but do not systematically vary with temperature. Variations in plagioclase compositions are minimal above H2O saturation (100-200°C, based on Papale et al., 2006). Below H2O saturation, An content decreases slightly, by approximately 4% An. One application of this work is better characterization of groundmass crystallization in hydrous basalt as it traverses the conduit during eruption. This work also provides a means of distinguishing groundmass plagioclase related to decompression from crystals

  8. The Impact of Extreme-Risk Cases on Hospitals’ Risk-Adjusted Percutaneous Coronary Intervention Mortality Ratings

    PubMed Central

    Sherwood, Matthew W.; Brennan, J. Matthew; Ho, Kalon K.; Masoudi, Frederick A.; Messenger, John C.; Weaver, W. Douglas; Dai, David; Peterson, Eric D.

    2017-01-01

    OBJECTIVES The goal of this study was to examine the calibration of a validated risk-adjustment model in very high-risk percutaneous coronary intervention (PCI) cases and assess whether sites’ case mix affects their performance ratings. BACKGROUND There are concerns that treating PCI patients with particularly high-risk features such as cardiogenic shock or prior cardiac arrest may adversely impact hospital performance ratings. However, there is little investigation on the validity of these concerns. METHODS We examined 624,286 PCI procedures from 1,168 sites that participated in the CathPCI Registry in 2010. Procedural risk was estimated using the recently published Version 4 National Cardiovascular Data Registry (NCDR) PCI risk-adjusted mortality (RAM) model. We calculated observed/expected mortality using several risk classification methods, and simulated hospital performance after combining their highest risk cases over 2 years into a single year. RESULTS In 2010, crude in-hospital PCI mortality was 1.4%. The NCDR model was generally well calibrated among high risk, however there was slight overprediction of risk in extreme cases. Hospitals treating the highest overall expected risk PCI patients or those treating the top 20% of high-risk cases had lower (better) RAM ratings than centers treating lower-risk cases (1.25% vs. 1.51%). The observed/expected ratio for top-risk quintile versus low-risk quintile was 0.91 (0.87 to 0.96) versus 1.10 (1.03 to 1.17). Combining all the high-risk patients over a 2-year period into a single year also did not negatively impact the site’s RAM ratings. CONCLUSIONS Evaluation of a contemporary sample of PCI cases across the United States showed no evidence that treating high-risk PCI cases adversely affects hospital RAM rates. PMID:25499301

  9. The impact of extreme-risk cases on hospitals' risk-adjusted percutaneous coronary intervention mortality ratings.

    PubMed

    Sherwood, Matthew W; Brennan, J Matthew; Ho, Kalon K; Masoudi, Frederick A; Messenger, John C; Weaver, W Douglas; Dai, David; Peterson, Eric D

    2015-01-01

    The goal of this study was to examine the calibration of a validated risk-adjustment model in very high-risk percutaneous coronary intervention (PCI) cases and assess whether sites' case mix affects their performance ratings. There are concerns that treating PCI patients with particularly high-risk features such as cardiogenic shock or prior cardiac arrest may adversely impact hospital performance ratings. However, there is little investigation on the validity of these concerns. We examined 624,286 PCI procedures from 1,168 sites that participated in the CathPCI Registry in 2010. Procedural risk was estimated using the recently published Version 4 National Cardiovascular Data Registry (NCDR) PCI risk-adjusted mortality (RAM) model. We calculated observed/expected mortality using several risk classification methods, and simulated hospital performance after combining their highest risk cases over 2 years into a single year. In 2010, crude in-hospital PCI mortality was 1.4%. The NCDR model was generally well calibrated among high risk, however there was slight overprediction of risk in extreme cases. Hospitals treating the highest overall expected risk PCI patients or those treating the top 20% of high-risk cases had lower (better) RAM ratings than centers treating lower-risk cases (1.25% vs. 1.51%). The observed/expected ratio for top-risk quintile versus low-risk quintile was 0.91 (0.87 to 0.96) versus 1.10 (1.03 to 1.17). Combining all the high-risk patients over a 2-year period into a single year also did not negatively impact the site's RAM ratings. Evaluation of a contemporary sample of PCI cases across the United States showed no evidence that treating high-risk PCI cases adversely affects hospital RAM rates. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. The biophysical and physiological basis for mitigated elevations in heart rate with electric fan use in extreme heat and humidity

    NASA Astrophysics Data System (ADS)

    Ravanelli, Nicholas M.; Gagnon, Daniel; Hodder, Simon G.; Havenith, George; Jay, Ollie

    2017-02-01

    Electric fan use in extreme heat wave conditions has been thought to be disadvantageous because it might accelerate heat gain to the body via convection. However, it has been recently shown that fan use delays increases in heart rate even at high temperatures (42 °C) in young adults. We here assess the biophysical and physiological mechanisms underlying the apparently beneficial effects of fan use. Eight males (24 ± 3 y; 80.7 ± 11.7 kg; 2.0 ± 0.1 m2) rested at either 36 °C or 42 °C, with (F) or without (NF) electric fan use (4.2 m/s) for 120 min while humidity increased every 7.5 min by 0.3 kPa from a baseline value of 1.6 kPa. Heart rate (HR), local sweat rate (LSR), cutaneous vascular conductance (CVC), core and mean skin temperatures, and the combined convective/radiative heat loss (C+R), evaporative heat balance requirements (Ereq) and maximum evaporative potential (Emax) were assessed. C+R was greater with fan use at 36 °C (F 8 ± 6, NF 2 ± 2 W/m2; P = 0.04) and more negative (greater dry heat gain) with fan use at 42 °C (F -78 ± 4, NF -27 ± 2 W/m2; P < 0.01). Consequently, Ereq was lower at 36 °C (F 38 ± 16, NF 45 ± 3 W/m2; P = 0.04) and greater at 42 °C (F 125 ± 1, NF 74 ± 3 W/m2; P < 0.01) with fan use. However, fan use resulted in a greater Emax at baseline humidity at both 36 °C (F 343 ± 10, NF 153 ± 5 W/m2; P < 0.01) and 42 °C (F 376 ± 13, NF 161 ± 4 W/m2; P < 0.01) and throughout the incremental increases in humidity. Within the humidity range that a rise in HR was prevented by fan use but not without a fan, LSR was higher in NF at both 36 °C ( P = 0.04) and 42 °C ( P = 0.05), and skin temperature was higher in NF at 42 °C ( P = 0.05), but no differences in CVC or core temperatures were observed (all P > 0.05). These results suggest that the delayed increase in heart rate with fan use during extreme heat and humidity is associated with improved evaporative efficiency.

  11. The biophysical and physiological basis for mitigated elevations in heart rate with electric fan use in extreme heat and humidity

    NASA Astrophysics Data System (ADS)

    Ravanelli, Nicholas M.; Gagnon, Daniel; Hodder, Simon G.; Havenith, George; Jay, Ollie

    2016-07-01

    Electric fan use in extreme heat wave conditions has been thought to be disadvantageous because it might accelerate heat gain to the body via convection. However, it has been recently shown that fan use delays increases in heart rate even at high temperatures (42 °C) in young adults. We here assess the biophysical and physiological mechanisms underlying the apparently beneficial effects of fan use. Eight males (24 ± 3 y; 80.7 ± 11.7 kg; 2.0 ± 0.1 m2) rested at either 36 °C or 42 °C, with (F) or without (NF) electric fan use (4.2 m/s) for 120 min while humidity increased every 7.5 min by 0.3 kPa from a baseline value of 1.6 kPa. Heart rate (HR), local sweat rate (LSR), cutaneous vascular conductance (CVC), core and mean skin temperatures, and the combined convective/radiative heat loss (C+R), evaporative heat balance requirements (Ereq) and maximum evaporative potential (Emax) were assessed. C+R was greater with fan use at 36 °C (F 8 ± 6, NF 2 ± 2 W/m2; P = 0.04) and more negative (greater dry heat gain) with fan use at 42 °C (F -78 ± 4, NF -27 ± 2 W/m2; P < 0.01). Consequently, Ereq was lower at 36 °C (F 38 ± 16, NF 45 ± 3 W/m2; P = 0.04) and greater at 42 °C (F 125 ± 1, NF 74 ± 3 W/m2; P < 0.01) with fan use. However, fan use resulted in a greater Emax at baseline humidity at both 36 °C (F 343 ± 10, NF 153 ± 5 W/m2; P < 0.01) and 42 °C (F 376 ± 13, NF 161 ± 4 W/m2; P < 0.01) and throughout the incremental increases in humidity. Within the humidity range that a rise in HR was prevented by fan use but not without a fan, LSR was higher in NF at both 36 °C (P = 0.04) and 42 °C (P = 0.05), and skin temperature was higher in NF at 42 °C (P = 0.05), but no differences in CVC or core temperatures were observed (all P > 0.05). These results suggest that the delayed increase in heart rate with fan use during extreme heat and humidity is associated with improved evaporative efficiency.

  12. Differential Effects of Temperature Extremes on Hospital Admission Rates for Respiratory Disease between Indigenous and Non-Indigenous Australians in the Northern Territory.

    PubMed

    Green, Donna; Bambrick, Hilary; Tait, Peter; Goldie, James; Schultz, Rosalie; Webb, Leanne; Alexander, Lisa; Pitman, Andrew

    2015-12-03

    The health gap between Indigenous and non-Indigenous Australians may be exacerbated by climate change if temperature extremes have disproportionate adverse effects on Indigenous people. To explore this issue, we analysed the effect of temperature extremes on hospital admissions for respiratory diseases, stratified by age, Indigenous status and sex, for people living in two different climates zones in the Northern Territory during the period 1993-2011. We examined admissions for both acute and chronic respiratory diagnoses, controlling for day of the week and seasonality variables. Our analysis showed that: (1) overall, Indigenous hospital admission rates far exceeded non-Indigenous admission rates for acute and chronic diagnoses, and Top End climate zone admission rates exceeded Central Australia climate zone admission rates; (2) extreme cold and hot temperatures were associated with inconsistent changes in admission rates for acute respiratory disease in Indigenous and non-Indigenous children and older adults; and (3) no response to cold or hot temperature extremes was found for chronic respiratory diagnoses. These findings support our two hypotheses, that extreme hot and cold temperatures have a different effect on hospitalisations for respiratory disease between Indigenous and non-Indigenous people, and that these health risks vary between the different climate zones. We did not, however, find that there were differing responses to temperature extremes in the two populations, suggesting that any increased vulnerability to climate change in the Indigenous population of the Northern Territory arises from an increased underlying risk to respiratory disease and an already greater existing health burden.

  13. Therapeutic effect of minimally invasive decompression combined with impaction bone grafting on osteonecrosis of the femoral head.

    PubMed

    Zhang, Hong-Jun; Liu, You-Wen; Du, Zhi-Qian; Guo, Huili; Fan, Ke-Jie; Liang, Guo-Hui; Liu, Xing-Cai

    2013-12-01

    The aim of this study was to observe the therapeutic effect of minimally invasive decompression combined with impaction bone grafting on osteonecrosis of the femoral head. A total of 67 patients underwent minimally invasive lightbulb decompression combined with impaction bone grafting. The therapeutic effect was evaluated according to Harris scores, and fluoroscopic and magnetic resolution imaging results at different time points. The Harris score was significantly increased after operation. The fineness rate was 85.4%. Postoperative disease progression was found in nine patients with the progression rate of 14.63%. The average necrotic area percentage was noticeably reduced 6 months, 1 year, and 2 years after operation. The one-year postoperative percentage showed a significant difference compared with the preoperative one. Minimally invasive lightbulb decompression combined with impaction bone grafting can achieve a satisfactory curative effect on ONFH. This method has the advantages of small trauma, thorough decompression, and good bone implantation.

  14. Effect of syneruptive decompression path on shifting intensity in basaltic sub-Plinian eruption: Implication of microlites in Yufune-2 scoria from Fuji volcano, Japan

    NASA Astrophysics Data System (ADS)

    Suzuki, Yuki; Fujii, Toshitsugu

    2010-12-01

    To constrain the timing and conditions of syneruptive magma ascent that are responsible for shifting eruption intensity, we have investigated a basaltic sub-Plinian eruption that produced Yufune-2 scoria in Fuji volcano 2200 years ago. We deduced magmatic decompression conditions from groundmass microlite textures, including decompression path (i.e. evolution in decompression rate) and approximate decompression rate, in order to relate them to eruption intensity. The microlites revealed decompression conditions after water saturation at 700-1100 m depth. The temporal change in scoria size indicates that the magma discharge rate and resultant eruption intensity increased from unit a to unit b, and then declined toward ending units d and e. The overall decompression rate in each eruptive unit has a positive correlation with eruption intensity. The variation in decompression rate was enlarged in the final units, where the maximum remained the same as the peak through the eruption (0.13-0.22 MPa/s for units b and c), while the minimum was 0.025 MPa/s. The large variation here is due to 1) variation in flow velocity across conduit and 2) part of the erupted magma in unit d experienced remarkably slow decompression (0.002-0.003 MPa/s) resulting from decreased overpressure in the reservoir following the major eruption of unit b. Furthermore, crystal size distribution (CSD) of microlites implied that the earliest erupted magma (unit a) had once been decompressed slowly (0.005-0.012 MPa/s), having been arrested by material in the conduit-vent system, which was followed by an increase in decompression rate due to removal of the material at the initiation of the eruption. In addition, the magma that had been ascending slowly before the unit-d eruption may record the increase in decompression rate. This increased rate resulted from being pushed up by the successive magma at the start of that eruption. Two factors had a major impact on eruption intensity. First, magma

  15. SISGR - In situ characterization and modeling of formation reactions under extreme heating rates in nanostructured multilayer foils

    SciTech Connect

    Hufnagel, Todd C.

    2014-06-09

    Materials subjected to extreme conditions, such as very rapid heating, behave differently than materials under more ordinary conditions. In this program we examined the effect of rapid heating on solid-state chemical reactions in metallic materials. One primary goal was to develop experimental techniques capable of observing these reactions, which can occur at heating rates in excess of one million degrees Celsius per second. One approach that we used is x-ray diffraction performed using microfocused x-ray beams and very fast x-ray detectors. A second approach is the use of a pulsed electron source for dynamic transmission electron microscopy. With these techniques we were able to observe how the heating rate affects the chemical reaction, from which we were able to discern general principles about how these reactions proceed. A second thrust of this program was to develop computational tools to help us understand and predict the reactions. From atomic-scale simulations were learned about the interdiffusion between different metals at high heating rates, and about how new crystalline phases form. A second class of computational models allow us to predict the shape of the reaction front that occurs in these materials, and to connect our understanding of interdiffusion from the atomistic simulations to measurements made in the laboratory. Both the experimental and computational techniques developed in this program are expected to be broadly applicable to a wider range of scientific problems than the intermetallic solid-state reactions studied here. For example, we have already begun using the x-ray techniques to study how materials respond to mechanical deformation at very high rates.

  16. The Effect of Extremely Low Frequency Pulsed Electromagnetic Field on In Vitro Fertilization Success Rate in N MRI Mice

    PubMed Central

    Hafizi, Leili; Sazgarnia, Ameneh; Mousavifar, Nezhat; Karimi, Mohammad; Ghorbani, Saleh; Kazemi, Mohammad Reza; Emami Meibodi, Neda; Hosseini, Golkoo; Mostafavi Toroghi, Hesam

    2014-01-01

    Objective: The effects of exposure to electromagnetic fields (EMF) on reproduction systems have been widely debated. In this study, we aimed to investigate whether low frequency EMF could ameliorate the in vitro fertilization success rate in Naval medical research institute (NMRI) Mice. Materials and Methods: In this randomized comparative animal study, ten NMRI mice were randomly divided into 2 equal groups (control and experimental). 10 IU of human chorionic gonadotropin (hCG) was injected intraperitoneally to both groups in order to stimulate ovulating, and ovums were then aspirated and kept in KSOM (modified version of sequential simplex optimization medium with a higher K+ concentration) culture medium. Metaphase II ovums were separated, and sperms obtained by "swim out" method were added to metaphase II ovums in the culture medium. The experimental group was exposed to 1.3 millitesla pulsed electromagnetic field at 4 kilohertz frequency for 5 hours. To assess the efficacy, we considered the identification of two-pronuclear zygote (2PN) under microscope as fertilizing criterion. Results: Total number of collected ovums in the control and experimental groups was 191 and 173, respectively, from which 58 (30.05%) and 52 (30.36%) ovums were collected from metaphase II, respectively. In vitro fertilization (IVF) success rate was 77% in extremely low frequency- pulsed electromagnetic field (ELFPEMF) for exposed group (experimental), whereas the rate was 68% for control group. Conclusion: Despite increased percentile of IVF success rate in exposed group, there was no statistically significant difference between 2 groups, but this hypothesis has still been stated as a question. Further studies with larger sample sizes and different EMF designs are suggested. PMID:24381855

  17. Case Control Study of Type II Decompression Sickness Associated with Patent Foramen Ovale in Experimental No-Decompression Dives

    DTIC Science & Technology

    2010-05-01

    DECOMPRESSION SICKNESS ASSOCIATED WITH PATENT FORAMEN OVALE IN EXPERIMENTAL NO-DECOMPRESSION DIVES Authors: Navy Experimental Diving Unit G. W. Latson...08 NO. 11. TITLE (Include Security Classification) (U) Case Control Study of Type II Decompression Sickness Associated with Patent Foramen Ovale in...reverse if necessary 17. COSATI CODES and identify by block number) FIELD GROUP SUB-GROUP Decompression sickness, DCS, DCI, patent foramen ovale , PFO

  18. Extremely slow rate of evolution in the HOX cluster revealed by comparison between Tanzanian and Indonesian coelacanths.

    PubMed

    Higasa, Koichiro; Nikaido, Masato; Saito, Taro L; Yoshimura, Jun; Suzuki, Yutaka; Suzuki, Hikoyu; Nishihara, Hidenori; Aibara, Mitsuto; Ngatunga, Benjamin P; Kalombo, Hassan W J; Sugano, Sumio; Morishita, Shinichi; Okada, Norihiro

    2012-09-01

    Coelacanths are known as "living fossils" because their morphology has changed very little from that in the fossil record. To elucidate why coelacanths have evolved so slowly is thus of primary importance in evolutionary biology. In the present study, we determined the entire sequence of the HOX cluster of the Tanzanian coelacanth (Latimeria chalumnae) and compared it with that of the Indonesian coelacanth (L. menadoensis), which was available in the literature. The most intriguing result was the extremely small genetic divergence between the two coelacanths. The synonymous divergence of the HOX coding region between the two coelacanths was estimated to be 0.07%, which is ~11-fold smaller than that of human-chimp. When we applied the estimated divergence time of the two coelacanths of 6 million years ago (MYA) and 30 MYA, which were proposed in independent mitochondrial DNA analyses, the synonymous substitution rate of the coelacanth HOX cluster was estimated to be ~11-fold and 56-fold smaller than that of human-chimp, respectively. Thus, the present study implies that the reduction of the nucleotide substitution rate in coelacanth HOX genes may account for the conservation of coelacanth morphology during evolution.

  19. Diffusion tensor MRI of spinal decompression sickness

    PubMed Central

    Hutchinson, Elizabeth B.; Sobakin, Aleksey S.; Meyerand, Mary E.; Eldridge, Marlowe; Ferrazzano, Peter

    2013-01-01

    In order to develop more sensitive imaging tools for clinical use and basic research of spinal decompression sickness (DCS), we used diffusion tensor MRI (DTI) validated by histology to assess DCS-related tissue injury in sheep spinal cords. DTI is based on the measurement of water diffusion indices, including fractional anisotropy (FA) and mean diffusion (MD) to detect tissue microstructural abnormalities. In this study, we measured FA and MD in white and gray matter spinal cord regions in samples taken from sheep following hyperbaric exposure to 60–132 fsw and 0–180 minutes of oxygen pre-breathing treatment before rapid decompression. The main finding of the study was that decompression from >60 fsw resulted in reduced FA that was associated with cell death and disrupted tissue microstructure in spinal cord white matter tracts. Additionally, animals exposed to prolonged oxygen pre-breathing prior to decompression demonstrated reduced MD in spinal cord gray matter regions regardless of dive depth. To our knowledge, this is the first study to demonstrate the utility of DTI for the investigation of DCS-related injury and to define DTI biomarkers of spinal DCS. PMID:23397865

  20. Diffusion tensor MRI of spinal decompression sickness.

    PubMed

    Hutchinson, Elizabeth B; Sobakin, Aleksey S; Meyerand, Mary E; Eldridge, Marlowe; Ferrazzano, Peter

    2013-01-01

    In order to develop more sensitive imaging tools for clinical use and basic research of spinal decompression sickness (DCS), we used diffusion tensor MRI (DTI) validated by histology to assess DCS-related tissue injury in sheep spinal cords. DTI is based on the measurement of water diffusion indices, including fractional anisotropy (FA) and mean diffusion (MD) to detect tissue microstructural abnormalities. In this study, we measured FA and MD in white and gray matter spinal cord regions in samples taken from sheep following hyperbaric exposure to 60-132 fsw and 0-180 minutes of oxygen pre-breathing treatment before rapid decompression. The main finding of the study was that decompression from >60 fsw resulted in reduced FA that was associated with cell death and disrupted tissue microstructure in spinal cord white matter tracts. Additionally, animals exposed to prolonged oxygen pre-breathing prior to decompression demonstrated reduced MD in spinal cord gray matter regions regardless of dive depth. To our knowledge, this is the first study to demonstrate the utility of DTI for the investigation of DCS-related injury and to define DTI biomarkers of spinal DCS.

  1. Bilateral failure of adduction following orbital decompression.

    PubMed Central

    Kinsella, F; Kyle, P; Stansfield, A

    1990-01-01

    We report a case of bilateral complete failure of adduction following bilateral translid antralethmoidal orbital decompression. We believe the probable mechanism is neuropraxia (temporary dysfunction) of the third cranial nerves' supply to the medial recti, owing to these nerves' occupying an anatomically abnormal position. Partial recovery of adduction occurred over the ensuing six months. Images PMID:2337551

  2. Postsurgical decompression and immediate elemental feeding.

    PubMed

    Moss, G

    1977-05-01

    The paralytic ileus, poor nutritional state, and related complications that often develop following serious serious abdominal surgery have traditionally been accepted as unavoidable. Now, a nasogastric decompression and feeding tube is availabe that usually prevents paralytic ileus and also provides a complete liquid diet starting immedicately after the operation, thus speeding wound healing and recivery.

  3. A Pottery Electric Kiln Using Decompression

    NASA Astrophysics Data System (ADS)

    Naoe, Nobuyuki; Yamada, Hirofumi; Nakayama, Tetsuo; Nakayama, Minoru; Minamide, Akiyuki; Takemata, Kazuya

    This paper presents a novel type electric kiln which fires the pottery using the decompression. The electric kiln is suitable for the environment and the energy saving as the pottery furnace. This paper described the baking principle and the baking characteristic of the novel type electric kiln.

  4. Decompression Sickness Risk Versus Time and Altitude

    DTIC Science & Technology

    1993-11-01

    M, Wiegman J, Pilmanis exposure at 22,500 ft (Fig. 1-2) should raise AA. Prebreathe enhancement with concern since that level of decompression is...Andrew A. P11manis in a research phyniologist 2. Fischer MO, Wiegman JF, McLean SA, Olson Andrew A. ihi ish resiarch poycioo SRM. Evaluation of four

  5. The Effect of Temperature on Decompression and Decompression Sickness Risk: A Critical Review

    DTIC Science & Technology

    2004-09-01

    DECOMPRESSION AND DECOMPRESSION SICKNESS RISK: A CRITICAL REVIEW Charles B. Toner, MD Robert Ball, MD Bureau of Medicine and Surgery Department of...SICKNESS RISK: A CRITICAL REVIEW Charles B. Toner, MD Robert Ball, MD Bureau of Medicine and Surgery Department of the Navy Washington, DC 20372-5120...of Medicine and Surgery BUMED (Med-02) 2300 E. Street, N.W. 11. SPONSOR/MONITOR’S REPORT Washington, DC 20372-5300 NUMBER(S) DN241126 12. DISTRIBUTION

  6. Relationship between two different functions derived from diffusion-based decompression theory.

    PubMed

    Ashida, H; Ikeda, T; Tikuisis, P; Nishi, R Y

    2005-01-01

    Hempleman's diffusion-based decompression theory yields two different functions; one is expressed by a simple root function and the other by a complex series function. Although both functions predict the same rate of gas uptake for relatively short exposure times, no clear mathematical explanation has been published that describes the relationship between the two functions. We clarified that (1) the root function is the solution of the one-dimensional diffusion equation for a semi-infinite slab, (2) the series function is an applicable solution for a finite slab thickness, (3) the parameter values of the root function can be used to determine the parameter values of the series function, and (4) the predictions of gas kinetics from both functions agree until an adequate amount of diffusing inert gas reaches the boundary at the opposite end of the finite slab. The last point allows the use of the simpler root function for predicting short no-stop decompression limits. Experience dictates that the inert gas accumulation for a 22 min at 100 feet of seawater (fsw) dive is considered safe for no-stop decompression. Although the constraint, Depth square root of Bottom Time = 100 square root of 22, has been applied as an index to determine either the safe depth or bottom time (given the other) for no-stop decompression, it should not be applied more broadly to dives requiring decompression stops.

  7. [Analysis of decompression safety during extravehicular activity of astronauts in the light of probability theory].

    PubMed

    Nikolaev, V P; Katuntsev, V P

    1998-01-01

    Objectives of the study were comparative assessment of the risk of decompression sickness (DCS) in human subjects during shirt-sleeve simulation of extravehicular activity (EVA) following Russian and U.S. protocols, and analysis of causes of the difference between real and simulated EVA decompression safety. To this end, DCS risk during exposure to a sing-step decompression was estimated with an original method. According to the method, DCS incidence is determined by distribution of nucleation efficacy index (z) in the worst body tissues and its critical values (zm) as a function of initial nitrogen tension in these tissues and final ambient pressure post decompression. Gaussian distribution of z values was calculated basing on results of the DCS risk evaluation on the U.S. EVA protocol in an unsuited chamber test with various pre-breath procedures (Conkin et al., 1987). Half-time of nitrogen washout from the worst tissues was presumed to be 480 min. Calculated DCS risk during short-sleeve EVA simulation by the Russian and U.S. protocols with identical physical loading made up 19.2% and 23.4%, respectively. Effects of the working spacesuit pressure, spacesuit rigidity, metabolic rates during operations in EVA space suit, transcutaneous nitrogen exchange in the oxygen atmosphere of space suit, microgravity, analgesics, short compression due to spacesuit leak tests on the eye of EVA are discussed. Data of the study illustrate and advocate for high decompression safety of current Russian and U.S. EVA protocols.

  8. THE LONG-TERM DECAY IN PRODUCTION RATES FOLLOWING THE EXTREME OUTBURST OF COMET 17P/HOLMES

    SciTech Connect

    Schleicher, David G.

    2009-10-15

    Numerous sets of narrowband filter photometry were obtained of Comet 17P/Holmes from Lowell Observatory during the interval of 2007 November 1 to 2008 March 5. Observations began 8 days following its extreme outburst, at which time the derived water production rate, based on OH measurements, was 5 x 10{sup 29} molecule s{sup -1} and the derived proxy of dust production, A({theta})f{rho}, was about 5 x 10{sup 5} cm. Relative production rates for the other gas species, CN, C{sub 2}, C{sub 3}, and NH, are consistent with 'typical' composition (based on our update to the classifications by A'Hearn et al.). An exponential decay in the logarithm of measured production rates as a function of time was observed for all species, with each species dropping by factors of about 200-500 after 125 days. All gas species exhibited clear trends with aperture size, and these trends are consistent with larger apertures having a greater proportion of older material that was released when production rates were higher. Much larger aperture trends were measured for the dust, most likely because the dust grains have smaller outflow velocities and longer lifetimes than the gas species; therefore, a greater proportion of older, i.e., higher production dust is contained within a given aperture. By extrapolating to a sufficiently small aperture size, we derive near-instantaneous water and dust production rates throughout the interval of observation, and also estimate values immediately following the outburst. The finite lifetime of the gas species requires that much higher ice vaporization rates were taking place throughout the observation interval than occurred prior to the outburst, likely due to the continued release of icy grains from the nucleus. The relatively small aperture trends for the gas species also imply that the bulk of fresh, excess volatiles are confined to the nucleus and near-nucleus regime, rather than being associated with the outburst ejecta cloud. A minimum of about 0

  9. Extreme Uplift and Erosion Rates in Eastern Himalayas (Siang-Brahmaputra Basin) Revealed by Detrital (U-Th)/He Termochronology

    NASA Astrophysics Data System (ADS)

    Tibari, B.; Pik, R.; France-Lanord, C.; Carignan, J.; Lave, J.

    2005-12-01

    The distribution of erosion intensity in a major mountain range such as the Himalaya is a fundamental clue to investigate the interaction between climatic, tectonic and erosion processes that govern the morphology and evolution of an orogen. At the first order, the sediment flux measured on the two major rivers - Ganga and Brahmaputra - suggest higher mean denudation rates for the Eastern Himalaya than Western Himalaya (Galy and France-Lanord, 2001). However, the distribution of erosion in the Brahmaputra basin is not uniform and the Namche Barwa area, drained by the Siang-Tsangpo, appears to supply up to 50 % of the total sediment flux of the Brahmaputra (Singh and France-Lanord, 2002). In order to further constrain the relationships between such localized erosion and the associated exhumation rate of basement, we measured (U-Th)/He ages in detrital zircons from river sediments in the Brahmaputra basin. This thermochronological system (Z-He) is particularly interesting for detrital material because: (i) zircon is preserved during weathering and erosion processes, (ii) its closure temperature (150-180°C, Reiners et al., 2004) corresponds to a depth which is close to the surface but deep enough to avoid perturbations by topography variations, and (iii) the error associated to single grain measurement (8-10 %) allows a good definition of population ages. Z-He ages from the Brahmaputra river in Bangladesh range from 0.4 to 77 Ma. 40 % of the zircon population exhibit Z-He ages between 0.4 and 1 Ma defining the major distribution peak centred at 0.5 Ma. These very young ages correspond to extreme denudation rates of 5 to 7 mm/yr. Dispersed Z-He ages from 12 to 77 Ma do not define any population groups, whereas the remaining 40 % of the zircons have ages distributed between 2.5 and 7 Ma, which correspond to the pool of ages recorded by preliminary Z-He ages on the other Himalayan rivers of the basin. Therefore, such very high denudation rates (5-7 mm/yr) seems to

  10. IrisCode decompression based on the dependence between its bit pairs.

    PubMed

    Kong, Adams Wai-Kin

    2012-03-01

    IrisCode is an iris recognition algorithm developed in 1993 and continuously improved by Daugman. Understanding IrisCode's properties is extremely important because over 60 million people have been mathematically enrolled by the algorithm. In this paper, IrisCode is proved to be a compression algorithm, which is to say its templates are compressed iris images. In our experiments, the compression ratio of these images is 1:655. An algorithm is designed to perform this decompression by exploiting a graph composed of the bit pairs in IrisCode, prior knowledge from iris image databases, and the theoretical results. To remove artifacts, two postprocessing techniques that carry out optimization in the Fourier domain are developed. Decompressed iris images obtained from two public iris image databases are evaluated by visual comparison, two objective image quality assessment metrics, and eight iris recognition methods. The experimental results show that the decompressed iris images retain iris texture that their quality is roughly equivalent to a JPEG quality factor of 10 and that the iris recognition methods can match the original images with the decompressed images. This paper also discusses the impacts of these theoretical and experimental findings on privacy and security.

  11. Ethmoidectomy decompression for the treatment of Graves' optic neuropathy.

    PubMed

    Hurwitz, J J; Freeman, J L; Eplett, C J; Fliss, D M; Avram, D R

    1992-10-01

    When orbital decompression becomes necessary in Graves' optic neuropathy, medial wall decompression is a necessary component of the decompression procedure. The ethmoidectomy approach allows more direct visualization of the posterior ethmoids and sphenoids to effect maximum decompression. This is particularly important in cases in which computed tomography shows the medial rectus muscle to be enlarged posteriorly in the orbit. The procedure provides excellent visualization of the medial rectus. As with any medial wall decompression procedure, postoperative restriction of horizontal motility is a frequent complication, often necessitating more than one subsequent operation. The authors describe their experience with the procedure in 25 patients with Graves' optic neuropathy.

  12. Decompression without Fusion for Low-Grade Degenerative Spondylolisthesis

    PubMed Central

    Cheung, Jason Pui Yin; Cheung, Prudence Wing Hang; Cheung, Kenneth Man Chee

    2016-01-01

    Study Design Retrospective series. Purpose Assess results of decompression-only surgery for low-grade degenerative spondylolisthesis with consideration of instability. Overview of Literature There is no consensus on whether fusion or decompression-only surgery leads to better outcomes for patients with low-grade degenerative spondylolisthesis. Current trends support fusion but many studies are flawed due to over-generalization without consideration of radiological instability and their variable presentations and natural history. Methods Patients with surgically treated degenerative spondylolisthesis from 1990–2013 were included. Clinical and radiological instability measures were included. Any residual or recurrence of symptoms, revision surgery performed and functional outcome scores including the numerical global rate of change scale, visual analogue scale, and modified Barthel index were measured. Follow-up periods for patients were divided into short-term (<5 years), mid-term (5–10 years) and long-term (>10 years). Results A total of 64 patients were recruited. Mechanical low back pain was noted in 48 patients and most (85.4%) had relief of back pain postoperatively. Radiological instability was noted in 4 subjects by flexion-extension radiographs and 12 subjects with prone traction radiographs by increased disc height and reduction of olisthesis and slip angle. From the results of the short-term, mid-term and long-term follow-up, reoperation only occurred within the first 5-year follow-up period. All functional scores improved from preoperative to postoperative 1-year follow-up. Conclusions Decompression-only for low-grade degenerative spondylolisthesis has good long-term results despite instability. Further higher-level studies should be performed on this patient group with radiological instability to suggest the superior surgical option. PMID:26949462

  13. Diving decompression models and bubble metrics: modern computer syntheses.

    PubMed

    Wienke, B R

    2009-04-01

    A quantitative summary of computer models in diving applications is presented, underscoring dual phase dynamics and quantifying metrics in tissue and blood. Algorithms covered include the multitissue, diffusion, split phase gradient, linear-exponential, asymmetric tissue, thermodynamic, varying permeability, reduced gradient bubble, tissue bubble diffusion, and linear-exponential phase models. Defining relationships are listed, and diver staging regimens are underscored. Implementations, diving sectors, and correlations are indicated for models with a history of widespread acceptance, utilization, and safe application across recreational, scientific, military, research, and technical communities. Presently, all models are incomplete, but many (included above) are useful, having resulted in diving tables, underwater meters, and dive planning software. Those herein employ varying degrees of calibration and data tuning. We discuss bubble metrics in tissue and blood as a backdrop against computer models. The past 15 years, or so, have witnessed changes and additions to diving protocols and table procedures, such as shorter nonstop time limits, slower ascent rates, shallow safety stops, ascending repetitive profiles, deep decompression stops, helium based breathing mixtures, permissible reverse profiles, multilevel techniques, both faster and slower controlling repetitive tissue halftimes, smaller critical tensions, longer flying-after-diving surface intervals, and others. Stimulated by Doppler and imaging technology, table and decompression meter development, theory, statistics, chamber and animal testing, or safer diving consensus, these modifications affect a gamut of activity, spanning bounce to decompression, single to multiday, and air to mixed gas diving. As it turns out, there is growing support for many protocols on operational, experimental, and theoretical grounds, with bubble models addressing many concerns on plausible bases, but with further testing or

  14. Rapid decompression of seeded melts for materials processing

    NASA Astrophysics Data System (ADS)

    Qiu, Ning; Apfel, Robert E.

    1995-05-01

    A novel processing approach and experimental design to achieve as-cast bulk amorphous materials are investigated. By sudden decompression of a melt that is seeded with a volatile liquid, the dispersed ``foaming'' liquid vaporizes, taking its latent heat of vaporization from the melt, thereby homogeneously cooling the melt. Due to a high decompression rate, a sufficient cooling rate may be produced to yield an amorphous solid foam. The resulting ``foam glass'' is expected to be an open solid bulk structure that may possess glass properties and low density. These foam glass materials should be free of structural defects, and may have many potential applications. The ultimate goal for this form glass processing is to produce bulk amorphous metallic solids. This approach differs from other processes used in the production of metals with a porous structure. A description of the approach, the processing design and techniques, as well as some evaluation of foam processing with the organic p-terphenyl as a sample material are presented. Foam (p-terphenyl) is an open, porous, and yet interconnected structure, and can be made with a density as low as 12% of the original density of p-terphenyl. Extension of this principle to foam metallic glass processing is anticipated. Design of a more sophisticated apparatus for metal processing, currently in progress, is discussed.

  15. High neurological complication rates for extreme lateral lumbar interbody fusion and related techniques: A review of safety concerns.

    PubMed

    Epstein, Nancy E

    2016-01-01

    There are frequent reports of lumbosacral plexus and other neurological injuries occurring with extreme lateral interbody fusions (XLIF) and other related lateral lumbar techniques. This review focuses on the new neurological deficits (e.g. lumbosacral plexus, root injuries) that occur following minimally invasive surgery (MIS) XLIF and other related lateral lumbar techniques. A review of multiple articles revealed the following ranges of new postoperative neurological complications for XLIF procedures: plexus injuries 13.28%; sensory deficits 0-75% (permanent in 62.5%); motor deficits 0.7-33.6%; anterior thigh pain 12.5-25%. Of interest, in a study by Lykissas et al., the frequency of long-term neural injury following lateral lumber interbody fusion (LLIF) with BMP-2 (72 patients) was much higher than for LLIF performed with autograft/allograft (72 patients). The addition of bone morphogenetic protein led to persistent sensory deficits in 29 vs. 20 without BMP; persistent motor deficits in 35 with vs. 17 without BMP; and persistent anterior thigh/groin pain in 8 with vs. 0 without BMP. They should also have noted the unacceptably high incidence of neural injury occurring with LLIF alone without BMP. This review highlights the high risk of neural injury (up to 75% for sensory, 33.6% for motor, and an overall plexus injury rate of 13.28%) utilizing the XLIF and other similar lateral lumbar approaches. With such extensive neurological injuries, is the XLIF really safe, and should it still be performed?

  16. Weak-Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-Line Regions?

    NASA Astrophysics Data System (ADS)

    Shemmer, Ohad; Trakhtenbrot, B.; Anderson, S. F.; Brandt, W. N.; Diamond-Stanic, A. M.; Fan, X.; Lira, P.; Netzer, H.; Plotkin, R. M.; Richards, G. T.; Schneider, D. P.; Strauss, M. A.

    2011-01-01

    We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z=3.55 and SDSS J123743.08+630144.9 at z=3.49. In both sources we detect an unusually weak broad Hβ line and we place tight upper limits on the strengths of their [O III] lines. Virial, Hβ-based black-hole mass determinations indicate normalized accretion rates of L/LEdd=0.4 for these sources, which is well within the range observed for typical quasars with similar luminosities and redshifts. We also present high-quality XMM-Newton imaging spectroscopy of SDSS J114153.34+021924.3 and find a hard-X-ray photon index of Γ=1.91+0.24-0.22which supports the virial L/LEdd determination in this source. Our results suggest that the weakness of the broad-emission lines in WLQs is not a consequence of an extreme continuum-emission source but instead due to abnormal broad-emission line region properties.

  17. The biophysical and physiological basis for mitigated elevations in heart rate with electric fan use in extreme heat and humidity.

    PubMed

    Ravanelli, Nicholas M; Gagnon, Daniel; Hodder, Simon G; Havenith, George; Jay, Ollie

    2017-02-01

    Electric fan use in extreme heat wave conditions has been thought to be disadvantageous because it might accelerate heat gain to the body via convection. However, it has been recently shown that fan use delays increases in heart rate even at high temperatures (42 °C) in young adults. We here assess the biophysical and physiological mechanisms underlying the apparently beneficial effects of fan use. Eight males (24 ± 3 y; 80.7 ± 11.7 kg; 2.0 ± 0.1 m(2)) rested at either 36 °C or 42 °C, with (F) or without (NF) electric fan use (4.2 m/s) for 120 min while humidity increased every 7.5 min by 0.3 kPa from a baseline value of 1.6 kPa. Heart rate (HR), local sweat rate (LSR), cutaneous vascular conductance (CVC), core and mean skin temperatures, and the combined convective/radiative heat loss (C+R), evaporative heat balance requirements (Ereq) and maximum evaporative potential (Emax) were assessed. C+R was greater with fan use at 36 °C (F 8 ± 6, NF 2 ± 2 W/m(2); P = 0.04) and more negative (greater dry heat gain) with fan use at 42 °C (F -78 ± 4, NF -27 ± 2 W/m(2); P < 0.01). Consequently, Ereq was lower at 36 °C (F 38 ± 16, NF 45 ± 3 W/m(2); P = 0.04) and greater at 42 °C (F 125 ± 1, NF 74 ± 3 W/m(2); P < 0.01) with fan use. However, fan use resulted in a greater Emax at baseline humidity at both 36 °C (F 343 ± 10, NF 153 ± 5 W/m(2); P < 0.01) and 42 °C (F 376 ± 13, NF 161 ± 4 W/m(2); P < 0.01) and throughout the incremental increases in humidity. Within the humidity range that a rise in HR was prevented by fan use but not without a fan, LSR was higher in NF at both 36 °C (P = 0.04) and 42 °C (P = 0.05), and skin temperature was higher in NF at 42 °C (P = 0.05), but no differences in CVC or core temperatures were observed (all P > 0.05). These results suggest that the delayed increase in heart rate with fan use during extreme heat and humidity is associated with improved

  18. Posterior decompression of spinal hydatidosis: long term results: Fundacion Jimenez Diaz, Madrid, Spain.

    PubMed

    Khazim, Rabi; Fares, Youssef; Heras-Palou, C; Ruiz Barnes, P

    2003-07-01

    Seven cases of spinal hydatid disease treated with posterior decompression were followed-up for an average of 20 years. The long-term results were very poor, with high rates of mortality, localised and extra-vertebral recurrence, significant neurological deficits, spino-cutaneous fistulae, spinal instability and pain.

  19. USAF Experience with Hyperbaric Therapy of Altitude Decompression Sickness (1941-1999)

    DTIC Science & Technology

    1999-01-01

    Operational Medical Issues in Hypo-and Hyperbaric Conditions [les Questions medicales a caractere oprationel liees aux conditions hypobares ou hyperbares...observed differences have been variously attributed to fat and/or hormones . (15,16,18) In any event, again, the actual rates of decompression sickness

  20. Ambulation Increases Decompression Sickness in Altitude Exposure

    NASA Technical Reports Server (NTRS)

    Conkin, Johnny; Pollock, N. W.; Natoli, M. J.; Wessel, J. H., III; Gernhardt, M. L.

    2014-01-01

    INTRODUCTION - Exercise accelerates inert gas elimination during oxygen breathing prior to decompression (prebreathe), but may also promote bubble formation and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of exercise are likely critical to the net effect. The NASA Prebreathe Reduction Program (PRP) combined oxygen prebreathe and exercise preceding a 4.3 psi exposure in non-ambulatory subjects (a microgravity analog) to produce two protocols now used by astronauts preparing for extravehicular activity (CEVIS and ISLE). Additional work is required to investigate whether exercise normal to 1 G environments increases the risk of DCS over microgravity simulation. METHODS - The CEVIS protocol was replicated with one exception. Our subjects completed controlled ambulation (walking in place with fixed cadence and step height) during both preflight and at 4.3 psi instead of remaining non-ambulatory throughout. Decompression stress was graded with aural Doppler (Spencer 0-IV scale). Two-dimensional echocardiographic imaging was used to look for left heart gas emboli (the presence of which prompted test termination). Venous blood was collected at three points to correlate Doppler measures of decompression stress with microparticle (cell fragment) accumulation. Fisher Exact Tests compared test and control groups. Trial suspension would occur when DCS risk >15% or grade IV venous gas emboli (VGE) risk >20% (at 70% confidence). RESULTS - Eleven person-trials were completed (9 male, 2 female) when DCS prompted suspension. DCS was greater than in CEVIS trials (3/11 [27%] vs. 0/45 [0%], respectively, p=0.03). Statistical significance was not reached for peak grade IV VGE (2/11 [18%] vs. 3/45 [7%], p=0.149) or cumulative grade IV VGE observations per subject-trial (8/128 [6%] vs. 26/630 [4%], p=0.151). Microparticle data were collected for 5/11 trials (3 with DCS outcomes), with widely varying patterns that could not be resolved statistically

  1. Echo imaging in decompression sickness research

    NASA Astrophysics Data System (ADS)

    Olson, Robert M.; Pilmanis, Andrew A.; Scoggins, Terrell E.

    For two decades a noninvasive, ultrasonic Doppler device has been available to detect the bubbles associated with decompression sickness (DCS) in humans. Although it is of undisputed value in DCS research, this device has some limitations. First, the signals from the bubbles produce sounds rather than visual images. Second, the bubbles have to be in motion and thus in the vascular system to be detected. Finally, no estimate of bubble size is easily available. A new type of ultrasonic device which overcomes these limitations has recently become available. This device was used to examine four decompressed subjects and it was found that this new device produces visual images of bubbles. These bubbles can be seen even if they are outside the vascular system and thus stationary. A preliminary attempt at estimating bubble size with this device is presented.

  2. Decompressive Hemicraniectomy in Acute Neurological Diseases.

    PubMed

    Crudele, Angela; Shah, Syed Omar; Bar, Barak

    2016-10-01

    Increased intracranial pressure (ICP) secondary to severe brain injury is common. Increased ICP is commonly encountered in malignant middle cerebral artery ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage. Multiple interventions-both medical and surgical-exist to manage increased ICP. Medical management is used as first-line therapy; however, it is not always effective and is associated with significant risks. Decompressive hemicraniectomy is a surgical option to reduce ICP, increase cerebral compliance, and increase cerebral blood perfusion when medical management becomes insufficient. The purpose of this review is to provide an up-to-date summary of the use of decompressive hemicraniectomy for the management of refractory elevated ICP in malignant middle cerebral artery ischemic stroke, traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage. © The Author(s) 2015.

  3. Treatment of hemimasticatory spasm with microvascular decompression.

    PubMed

    Wang, Yong-Nan; Dou, Ning-Ning; Zhou, Qiu-Meng; Jiao, Wei; Zhu, Jin; Zhong, Jun; Li, Shi-Ting

    2013-01-01

    Hemimasticatory spasm is a rare disorder characterized by paroxysmal involuntary contraction of the jaw-closing muscles. As the ideology and pathogenesis of the disease are still unclear, there has been no treatment that could give rise to a good outcome so far. Herein, we tried to use surgical management to cure the disease. Six patients with the disease were included in this study. These patients underwent microvascular decompression of the motor fibers of the trigeminal root. After the operation, all faces of the patients felt relaxed at varied degrees, except for 1 patient. Our study showed that microvascular decompression of the trigeminal nerve could lead to a better outcome. However, a control study with a large sample is needed before this technique is widely used.

  4. 1991 Volvo Award in experimental studies. Cauda equina syndrome: neurologic recovery following immediate, early, or late decompression.

    PubMed

    Delamarter, R B; Sherman, J E; Carr, J B

    1991-09-01

    An animal model of cauda equina syndrome was developed. Neurologic recovery was analyzed following immediate, early, and delayed decompression. Five experimental groups, each containing six dogs, were studied. Compression of the cauda equina was performed in all 30 dogs following an L6-7 laminectomy. The cauda equina was constricted by 75% in each group. The first group was constricted and immediately decompressed. The remaining groups were constricted for 1 hour, 6 hours, 24 hours, and 1 week, respectively, before being decompressed. Somatosensory evoked potentials were performed before and after surgery, before and immediately after decompression, and 6 weeks following decompression. Daily neurologic exams using the Tarlov grading scale were performed. At 6 weeks postdecompression, all dogs were killed, and the neural elements analyzed histologically. Following compression, all 30 dogs had significant lower extremity weakness, tail paralysis, and urinary incontinence. All dogs recovered significant motor function 6 weeks following decompression. The dogs with immediate decompression generally recovered neurologic function within 2-5 days. The dogs receiving 1-hour and 6-hour compression recovered within 5-7 days. The dogs receiving 24-hour compression remained paraparetic 5-7 days, with bladder dysfunction for 7-10 days and tail dysfunction persisting for 4 weeks. The dogs with compression for 1 week were paraparetic (Tarlov Grade 2 or 3) and incontinent during the duration of cauda equina compression. They recovered to walking by 1 week and Tarlov Grade 5 with bladder and tail control at the time of euthanasia. Immediately after compression, all five groups demonstrated at least 50% deterioration of the posterior tibial nerve evoked potential amplitudes.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Plants survive rapid decompression: Implications for bioregenerative life support

    NASA Astrophysics Data System (ADS)

    Wheeler, R. M.; Wehkamp, C. A.; Stasiak, M. A.; Dixon, M. A.; Rygalov, V. Y.

    2011-05-01

    Radish (Raphanus sativus), lettuce (Latuca sativa), and wheat (Triticum aestivum) plants were grown at either 98 kPa (ambient) or 33 kPa atmospheric pressure with constant 21 kPa oxygen and 0.12 kPa carbon dioxide in atmospherically closed pressure chambers. All plants were grown rockwool using recirculating hydroponics with a complete nutrient solution. At 20 days after planting, chamber pressures were pumped down as rapidly as possible, reaching 5 kPa after about 5 min and ˜1.5 kPa after about 10 min. The plants were held at 1.5 kPa for 30 min and then pressures were restored to their original settings. Temperature (22 °C) and humidity (65% RH) controls were engaged throughout the depressurization, although temperatures dropped to near 16 °C for a brief period. CO2 and O2 were not detectable at the low pressure, suggesting that most of the 1.5 kPa atmosphere consisted of water vapor. Following re-pressurization, plants were grown for another 7 days at the original pressures and then harvested. The lettuce, radish, and wheat plants showed no visible effects from the rapid decompression, and there were no differences in fresh or dry mass when compared to control plants maintained continuously at 33 or 98 kPa. But radish storage root fresh mass and lettuce head fresh and dry masses were less at 33 kPa compared to 98 kPa for both the controls and decompression treatment. The results suggest that plants are extremely resilient to rapid decompression, provided they do not freeze (from evaporative cooling) or desiccate. The water of the hydroponic system was below the boiling pressure during these tests and this may have protected the plants by preventing pressures from dropping below 1.5 kPa and maintaining humidity near 1.5 kPa. Further testing is needed to determine how long plants can withstand such low pressure, but the results suggest there are at least 30 min to respond to catastrophic pressure losses in a plant production chamber that might be used for life

  6. Can fan beam iCT accurately predict indirect decompression in MISS fusion procedures?

    PubMed

    Janssen, Insa; Lang, Gernot; Navarro-Ramirez, Rodrigo; Jada, Ajit; Berlin, Connor; Hilis, Aaron; Zubkov, Micaella; Gandevia, Lena; Härtl, Roger

    2017-08-07

    Recently, a novel mobile intraoperative fan-beam CT (iFBCT) was introduced, allowing for real time navigation and immediate intraoperative evaluation of neural decompression in spine surgery. This study sought to investigate whether intraoperatively assessed neural decompression during minimally invasive spine surgery (MISS) has a predictive value for clinical and radiographic outcome. A retrospective study of patients undergoing iCT-guided extreme lateral interbody fusion (XLIF) or transforaminal lumbar interbody fusion (TLIF) was conducted. Pre- (1) and intraoperative (after cage implantation; 2), postoperative (3), and follow-up (4) radiographic and clinical parameters obtained from X-rays or CT were quantified. 34 patients (41 spinal segments) were analyzed. iCT-based navigation was successfully accomplished in all patients. Radiographic parameters, revealed significant improvement from preoperatively to intraoperatively after cage implantation in both MISS procedures (XLIF/TLIF) (p≤0.05). Radiological parameters for both MISS fusion procedures did not reveal significant differences to the assessed radiographic measures at follow-up (P>0.05). Radiological outcome values did not decrease when compared intraoperatively (after cage implantation) to latest follow-up. Utilization of intraoperative fan-beam CT is capable of assessing neural decompression intraoperatively with high accuracy allowing for precise prediction of radiological outcome and earliest possible feedback during MISS fusion procedures. These findings are highly valuable for routine practice and future investigations towards finding a threshold for neural decompression that translates into clinical improvement. If sufficient neural decompression has been confirmed with iCT imaging studies, additional postoperative and/or follow-up imaging studies might no longer be required if patients remain asymptomatic. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Nasogastric decompression following esophagectomy: a systematic literature review and meta-analysis.

    PubMed

    Weijs, Teus J; Kumagai, Koshi; Berkelmans, Gijs H K; Nieuwenhuijzen, Grard A P; Nilsson, Magnus; Luyer, Misha D P

    2017-02-01

    Routine use of nasogastric tubes for gastric decompression has been abolished in nearly all types of gastro-intestinal surgery after introduction of enhanced recovery after surgery programs. However, in esophagectomy the routine use of nasogastric decompression is still a matter of debate. To determine the effects of routine nasogastric decompression following esophagectomy compared with early or peroperative removal of the nasogastric tube on pulmonary complications, anastomotic leakage, mortality, and postoperative recovery. A systematic literature review and meta-analysis of studies comparing early or peroperative versus late removal of nasogastric tubes. A total of seven comparative studies were included (n = 608). In two randomized trials, and one retrospective cohort study, peroperative removal of the nasogastric tube was compared with routine nasogastric decompression. In one randomized trial early removal of the nasogastric tube (on postoperative day 2) was compared with removal of the nasogastric tube on the 6th-10th postoperative day. In the remaining three trials a fast-track protocol without a nasogastric tube was compared with conventional care with a nasogastric tube during the first postoperative days. Peroperative or early removal of the nasogastric tube did not result in a significantly different rate of anastomotic leakage, pulmonary complications or mortality in individual studies, nor in the meta-analysis. In the meta-analysis, hospital stay was significantly shorter with peroperative or early removal of the nasogastric tube when all studies were included, but not when the meta-analysis was limited to randomized trials. This systematic review did not find a difference in adverse outcomes between nasogastric decompression or no nasogastric decompression following esophagectomy. © 2017 International Society for Diseases of the Esophagus.

  8. Gender not a factor for altitude decompression sickness risk

    NASA Technical Reports Server (NTRS)

    Webb, James T.; Kannan, Nandini; Pilmanis, Andrew A.

    2003-01-01

    INTRODUCTION: Early, retrospective reports of the incidence of altitude decompression sickness (DCS) during altitude chamber training exposures indicated that women were more susceptible than men. We hypothesized that a controlled, prospective study would show no significant difference. METHODS: We conducted 25 altitude chamber decompression exposure profiles. A total of 291 human subjects, 197 men and 94 women, underwent 961 exposures to simulated altitude for up to 8 h, using zero to 4 h of preoxygenation. Throughout the exposures, subjects breathed 100% oxygen, rested or performed mild or strenuous exercise, and were monitored for precordial venous gas emboli (VGE) and DCS symptoms. RESULTS: No significant differences in DCS incidence were observed between men (49.5%) and women (45.3%). However, VGE occurred at significantly higher rates among men than women under the same exposure conditions, 69.3% and 55.0% respectively. Women using hormonal contraception showed significantly greater susceptibility to DCS than those not using hormonal contraception during the latter two weeks of the menstrual cycle. Significantly higher DCS incidence was observed in the heaviest men, in women with the highest body fat, and in subjects with the highest body mass indices and lowest levels of fitness. CONCLUSION: No differences in altitude DCS incidence were observed between the sexes under our test conditions, although men developed VGE more often than women. Age and height showed no significant influence on DCS incidence, but persons of either sex with higher body mass index and lower physical fitness developed DCS more frequently.

  9. Gender not a factor for altitude decompression sickness risk

    NASA Technical Reports Server (NTRS)

    Webb, James T.; Kannan, Nandini; Pilmanis, Andrew A.

    2003-01-01

    INTRODUCTION: Early, retrospective reports of the incidence of altitude decompression sickness (DCS) during altitude chamber training exposures indicated that women were more susceptible than men. We hypothesized that a controlled, prospective study would show no significant difference. METHODS: We conducted 25 altitude chamber decompression exposure profiles. A total of 291 human subjects, 197 men and 94 women, underwent 961 exposures to simulated altitude for up to 8 h, using zero to 4 h of preoxygenation. Throughout the exposures, subjects breathed 100% oxygen, rested or performed mild or strenuous exercise, and were monitored for precordial venous gas emboli (VGE) and DCS symptoms. RESULTS: No significant differences in DCS incidence were observed between men (49.5%) and women (45.3%). However, VGE occurred at significantly higher rates among men than women under the same exposure conditions, 69.3% and 55.0% respectively. Women using hormonal contraception showed significantly greater susceptibility to DCS than those not using hormonal contraception during the latter two weeks of the menstrual cycle. Significantly higher DCS incidence was observed in the heaviest men, in women with the highest body fat, and in subjects with the highest body mass indices and lowest levels of fitness. CONCLUSION: No differences in altitude DCS incidence were observed between the sexes under our test conditions, although men developed VGE more often than women. Age and height showed no significant influence on DCS incidence, but persons of either sex with higher body mass index and lower physical fitness developed DCS more frequently.

  10. Differential Effects of Temperature Extremes on Hospital Admission Rates for Respiratory Disease between Indigenous and Non-Indigenous Australians in the Northern Territory

    PubMed Central

    Green, Donna; Bambrick, Hilary; Tait, Peter; Goldie, James; Schultz, Rosalie; Webb, Leanne; Alexander, Lisa; Pitman, Andrew

    2015-01-01

    The health gap between Indigenous and non-Indigenous Australians may be exacerbated by climate change if temperature extremes have disproportionate adverse effects on Indigenous people. To explore this issue, we analysed the effect of temperature extremes on hospital admissions for respiratory diseases, stratified by age, Indigenous status and sex, for people living in two different climates zones in the Northern Territory during the period 1993–2011. We examined admissions for both acute and chronic respiratory diagnoses, controlling for day of the week and seasonality variables. Our analysis showed that: (1) overall, Indigenous hospital admission rates far exceeded non-Indigenous admission rates for acute and chronic diagnoses, and Top End climate zone admission rates exceeded Central Australia climate zone admission rates; (2) extreme cold and hot temperatures were associated with inconsistent changes in admission rates for acute respiratory disease in Indigenous and non-Indigenous children and older adults; and (3) no response to cold or hot temperature extremes was found for chronic respiratory diagnoses. These findings support our two hypotheses, that extreme hot and cold temperatures have a different effect on hospitalisations for respiratory disease between Indigenous and non-Indigenous people, and that these health risks vary between the different climate zones. We did not, however, find that there were differing responses to temperature extremes in the two populations, suggesting that any increased vulnerability to climate change in the Indigenous population of the Northern Territory arises from an increased underlying risk to respiratory disease and an already greater existing health burden. PMID:26633456

  11. Oxygen Equipment and Rapid Decompression Studies

    DTIC Science & Technology

    1979-03-01

    of the aerodynamic ( Venturi ) effect . Blockley and Hanifan (5) describe this phenomenon in large (bomber) aircraft. The removal of doors and hatches...tudes as a result of increased descent time, the possibility of the Venturi effect , and additional physiological insults of decompression to 15,240 m...deSteiguer EFFECTIVENESS OF A PAPER CUP AS AN AID TO PROVIDING 94 OXYGEN TO LARYNCECTOMEE PASSENGERS by E. B. McFadden PHYSIOLOGICAL CONSIDERATIONS AND

  12. Space Flight Decompression Sickness Contingency Plan

    NASA Technical Reports Server (NTRS)

    Dervay, Joseph; Gernhardt, Michael L.; Ross, Charles E.; Hamilton, Douglas; Homick, Jerry L. (Technical Monitor)

    2000-01-01

    The purpose was to develop an enhanced plan to diagnose, treat, and manage decompression sickness (DCS) during extravehicular activity (EVA). This plan is merited by the high frequency of upcoming EVAs necessary to construct and maintain the International Space Station (ISS). The upcoming ISS era will demand a significant increase in EVA. The DCS Risk and Contingency Plan provided a new and improved approach to DCS reporting, treatment, management, and training.

  13. Identifying the Subtle Presentation of Decompression Sickness.

    PubMed

    Alea, Kenneth

    2015-12-01

    Decompression sickness is an inherent occupational hazard that has the possibility to leave its victims with significant long-lasting effects that can potentially impact an aircrew's flight status. The relative infrequency of this hazard within the military flying community along with the potentially subtle presentation of decompression sickness (DCS) has the potential to result in delayed diagnosis and treatment, leading to residual deficits that can impact a patient's daily life or even lead to death. The patient presented in this work was diagnosed with a Type II DCS 21 h after a cabin decompression at 35,000 ft (10,668 m). The patient had been asymptomatic with a completely normal physical/neurological exam following his flight. The following day, he presented with excessive fatigue and on re-evaluation was recommended for hyperbaric therapy, during which his symptoms completely resolved. He was re-evaluated 14 d later and cleared to resume flight duties without further incident. The manifestation of this patient's decompression sickness was subtle and followed an evaluation that failed to identify any focal findings. A high index of suspicion with strict follow-up contributed to the identification of DCS in this case, resulting in definitive treatment and resolution of the patient's symptoms. Determination of the need for hyperbaric therapy following oxygen supplementation and a thorough history and physical is imperative. If the diagnosis is in question, consider preemptive hyperbaric therapy as the benefits of treatment in DCS outweigh the risks of treatment. Finally, this work introduces the future potential of neuropsychological testing for both the diagnosis of DCS as well as assessing the effectiveness of hyperbaric therapy in Type II DCS.

  14. Decompression scenarios in a new underground transportation system.

    PubMed

    Vernez, D

    2000-10-01

    The risks of a public exposure to a sudden decompression, until now, have been related to civil aviation and, at a lesser extent, to diving activities. However, engineers are currently planning the use of low pressure environments for underground transportation. This method has been proposed for the future Swissmetro, a high-speed underground train designed for inter-urban linking in Switzerland. The use of a low pressure environment in an underground public transportation system must be considered carefully regarding the decompression risks. Indeed, due to the enclosed environment, both decompression kinetics and safety measures may differ from aviation decompression cases. A theoretical study of decompression risks has been conducted at an early stage of the Swissmetro project. A three-compartment theoretical model, based on the physics of fluids, has been implemented with flow processing software (Ithink 5.0). Simulations have been conducted in order to analyze "decompression scenarios" for a wide range of parameters, relevant in the context of the Swissmetro main study. Simulation results cover a wide range from slow to explosive decompression, depending on the simulation parameters. Not surprisingly, the leaking orifice area has a tremendous impact on barotraumatic effects, while the tunnel pressure may significantly affect both hypoxic and barotraumatic effects. Calculations have also shown that reducing the free space around the vehicle may mitigate significantly an accidental decompression. Numeric simulations are relevant to assess decompression risks in the future Swissmetro system. The decompression model has proven to be useful in assisting both design choices and safety management.

  15. Reversal of dysthyroid optic neuropathy following orbital fat decompression

    PubMed Central

    Kazim, M.; Trokel, S.; Acaroglu, G.; Elliott, A.

    2000-01-01

    AIMS—To document the successful treatment of five patients with dysthyroid optic neuropathy by orbital fat decompression instead of orbital bone decompression after failed medical therapy.
METHODS—Eight orbits of five patients with dysthyroid optic neuropathy were selected for orbital fat decompression as an alternative to bone removal decompression. Treatment with systemic corticosteroids and/or orbital radiotherapy was either unsuccessful or contraindicated in each case. All patients satisfied clinical indications for orbital bone decompression to reverse the optic neuropathy. High resolution computerised tomographic (CT) scans were performed in all cases and in each case showed signs of enlargement of the orbital fat compartment. As an alternative to bone decompression, orbital fat decompression was performed on all eight orbits.
RESULTS—Orbital fat decompression was performed on five patients (eight orbits) with optic neuropathy. Optic neuropathy was reversed in all cases. There were no cases of postoperative diplopia, enophthalmos, globe ptosis, or anaesthesia. All patients were followed for a minimum of 1 year.
CONCLUSIONS—In a subset of patients with an enlarged orbital fat compartment and in whom extraocular muscle enlargement is not the solitary cause of optic neuropathy, fat decompression is a surgical alternative to bony decompression.

 PMID:10837384

  16. Recreational technical diving part 2: decompression from deep technical dives.

    PubMed

    Doolette, David J; Mitchell, Simon J

    2013-06-01

    Technical divers perform deep, mixed-gas 'bounce' dives, which are inherently inefficient because even a short duration at the target depth results in lengthy decompression. Technical divers use decompression schedules generated from modified versions of decompression algorithms originally developed for other types of diving. Many modifications ostensibly produce shorter and/or safer decompression, but have generally been driven by anecdote. Scientific evidence relevant to many of these modifications exists, but is often difficult to locate. This review assembles and examines scientific evidence relevant to technical diving decompression practice. There is a widespread belief that bubble algorithms, which redistribute decompression in favour of deeper decompression stops, are more efficient than traditional, shallow-stop, gas-content algorithms, but recent laboratory data support the opposite view. It seems unlikely that switches from helium- to nitrogen-based breathing gases during ascent will accelerate decompression from typical technical bounce dives. However, there is evidence for a higher prevalence of neurological decompression sickness (DCS) after dives conducted breathing only helium-oxygen than those with nitrogen-oxygen. There is also weak evidence suggesting less neurological DCS occurs if helium-oxygen breathing gas is switched to air during decompression than if no switch is made. On the other hand, helium-to-nitrogen breathing gas switches are implicated in the development of inner-ear DCS arising during decompression. Inner-ear DCS is difficult to predict, but strategies to minimize the risk include adequate initial decompression, delaying helium-to-nitrogen switches until relatively shallow, and the use of the maximum safe fraction of inspired oxygen during decompression.

  17. High neurological complication rates for extreme lateral lumbar interbody fusion and related techniques: A review of safety concerns

    PubMed Central

    Epstein, Nancy E.

    2016-01-01

    Background: There are frequent reports of lumbosacral plexus and other neurological injuries occurring with extreme lateral interbody fusions (XLIF) and other related lateral lumbar techniques. Methods: This review focuses on the new neurological deficits (e.g. lumbosacral plexus, root injuries) that occur following minimally invasive surgery (MIS) XLIF and other related lateral lumbar techniques. Results: A review of multiple articles revealed the following ranges of new postoperative neurological complications for XLIF procedures: plexus injuries 13.28%; sensory deficits 0–75% (permanent in 62.5%); motor deficits 0.7–33.6%; anterior thigh pain 12.5–25%. Of interest, in a study by Lykissas et al., the frequency of long-term neural injury following lateral lumber interbody fusion (LLIF) with BMP-2 (72 patients) was much higher than for LLIF performed with autograft/allograft (72 patients). The addition of bone morphogenetic protein led to persistent sensory deficits in 29 vs. 20 without BMP; persistent motor deficits in 35 with vs. 17 without BMP; and persistent anterior thigh/groin pain in 8 with vs. 0 without BMP. They should also have noted the unacceptably high incidence of neural injury occurring with LLIF alone without BMP. Conclusion: This review highlights the high risk of neural injury (up to 75% for sensory, 33.6% for motor, and an overall plexus injury rate of 13.28%) utilizing the XLIF and other similar lateral lumbar approaches. With such extensive neurological injuries, is the XLIF really safe, and should it still be performed? PMID:27843679

  18. Nerve decompression and neuropathy complications in diabetes: Are attitudes discordant with evidence?

    PubMed

    Nickerson, D Scott

    2017-01-01

    External neurolysis of the nerve at fibro-osseous tunnels has been proprosed to treat or prevent signs, symptoms, and complications in the lower extremity of diabetes patients with sensorimotor polyneuropathy. Nerve decompression is justified in the presence of symptomatic compressed nerves in the several fibro-osseous tunnels of the extremities, which are known to be frequent in diabetes. Quite a body of literature has accumulated reporting results after such nerve decompression in the leg, describing pain relief and sensibility improvement, as well as balance recovery, diabetic foot ulcer prevention, curtailed ulcer recurrence risk, and amputation avoidance. Historical academic hesitance to endorse surgical treatments for pain and numbness in diabetes was based primarily on the early retrospective reports' potential for bias and placebo effects, and that the hypothetical basis for surgery lies outside the traditional etiology paradigm of length-dependent axonopathy. This reticence is here critiqued in view of recent studies using objective, measured outcome protocols which nullify such potential confounders. Pain relief is now confirmed with Level 1 studies, and Level 2 prospective information suggests protection from initial diabetic foot ulceration and most neuropathic ulcer recurrences. In view of the potential for nerve decompression to be useful in addressing some of the more difficult, expensive, and life altering complications of diabetic neuropathy, this secondary compression thesis and operative treatment methodology may deserve reassessment.

  19. The effect of nonlinear decompression history on H2O/CO2 vesiculation in rhyolitic magmas

    NASA Astrophysics Data System (ADS)

    Su, Yanqing; Huber, Christian

    2017-04-01

    Magma ascent rate is one of the key parameters that control volcanic eruption style, tephra dispersion, and volcanic atmospheric impact. Many methods have been employed to investigate the magma ascent rate in volcanic eruptions, and most rely on equilibrium thermodynamics. Combining the mixed H2O-CO2 solubility model with the diffusivities of both H2O and CO2 for normal rhyolitic melt, we model the kinetics of H2O and CO2 in rhyolitic eruptions that involve nonlinear decompression rates. Our study focuses on the effects of the total magma ascent time, the nonlinearity of decompression paths, and the influence of different initial CO2/H2O content on the posteruptive H2O and CO2 concentration profiles around bubbles within the melt. Our results show that, under most circumstances, volatile diffusion profiles do not constrain a unique solution for the decompression rate of magmas during an eruption, but, instead, provide a family of decompression paths with a well-defined trade-off between ascent time and nonlinearity. An important consequence of our analysis is that the common assumption of a constant decompression rate (averaged value) tends to underestimate the actual magma ascent time.

  20. Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension.

    PubMed

    Hutchinson, Peter J; Kolias, Angelos G; Timofeev, Ivan S; Corteen, Elizabeth A; Czosnyka, Marek; Timothy, Jake; Anderson, Ian; Bulters, Diederik O; Belli, Antonio; Eynon, C Andrew; Wadley, John; Mendelow, A David; Mitchell, Patrick M; Wilson, Mark H; Critchley, Giles; Sahuquillo, Juan; Unterberg, Andreas; Servadei, Franco; Teasdale, Graham M; Pickard, John D; Menon, David K; Murray, Gordon D; Kirkpatrick, Peter J

    2016-09-22

    The effect of decompressive craniectomy on clinical outcomes in patients with refractory traumatic intracranial hypertension remains unclear. From 2004 through 2014, we randomly assigned 408 patients, 10 to 65 years of age, with traumatic brain injury and refractory elevated intracranial pressure (>25 mm Hg) to undergo decompressive craniectomy or receive ongoing medical care. The primary outcome was the rating on the Extended Glasgow Outcome Scale (GOS-E) (an 8-point scale, ranging from death to "upper good recovery" [no injury-related problems]) at 6 months. The primary-outcome measure was analyzed with an ordinal method based on the proportional-odds model. If the model was rejected, that would indicate a significant difference in the GOS-E distribution, and results would be reported descriptively. The GOS-E distribution differed between the two groups (P<0.001). The proportional-odds assumption was rejected, and therefore results are reported descriptively. At 6 months, the GOS-E distributions were as follows: death, 26.9% among 201 patients in the surgical group versus 48.9% among 188 patients in the medical group; vegetative state, 8.5% versus 2.1%; lower severe disability (dependent on others for care), 21.9% versus 14.4%; upper severe disability (independent at home), 15.4% versus 8.0%; moderate disability, 23.4% versus 19.7%; and good recovery, 4.0% versus 6.9%. At 12 months, the GOS-E distributions were as follows: death, 30.4% among 194 surgical patients versus 52.0% among 179 medical patients; vegetative state, 6.2% versus 1.7%; lower severe disability, 18.0% versus 14.0%; upper severe disability, 13.4% versus 3.9%; moderate disability, 22.2% versus 20.1%; and good recovery, 9.8% versus 8.4%. Surgical patients had fewer hours than medical patients with intracranial pressure above 25 mm Hg after randomization (median, 5.0 vs. 17.0 hours; P<0.001) but had a higher rate of adverse events (16.3% vs. 9.2%, P=0.03). At 6 months, decompressive craniectomy in

  1. Global and Local Distortion Inference During Embedded Zerotree Wavelet Decompression

    NASA Technical Reports Server (NTRS)

    Huber, A. Kris; Budge, Scott E.

    1996-01-01

    This paper presents algorithms for inferring global and spatially local estimates of the squared-error distortion measures for the Embedded Zerotree Wavelet (EZW) image compression algorithm. All distortion estimates are obtained at the decoder without significantly compromising EZW's rate-distortion performance. Two methods are given for propagating distortion estimates from the wavelet domain to the spatial domain, thus giving individual estimates of distortion for each pixel of the decompressed image. These local distortion estimates seem to provide only slight improvement in the statistical characterization of EZW compression error relative to the global measure, unless actual squared errors are propagated. However, they provide qualitative information about the asymptotic nature of the error that may be helpful in wavelet filter selection for low bit rate applications.

  2. Type II decompression sickness in a hyperbaric inside attendant.

    PubMed

    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.

  3. Impact of timing of cranioplasty on hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction.

    PubMed

    Finger, Tobias; Prinz, Vincent; Schreck, Evelyn; Pinczolits, Alexandra; Bayerl, Simon; Liman, Thomas; Woitzik, Johannes; Vajkoczy, Peter

    2017-02-01

    Patients with malignant middle cerebral artery infarction frequently develop hydrocephalus after decompressive hemicraniectomy. Hydrocephalus itself and known shunt related complications after ventriculo-peritoneal shunt implantation may negatively impact patientś outcome. Here, we aimed to identify factors associated with the development of hydrocephalus after decompressive hemicraniectomy in malignant middle cerebral artery infarction. A total of 99 consecutive patients with the diagnosis of large hemispheric infarctions and the indication for decompressive hemicraniectomy were included. We retrospectively evaluated patient characteristics (gender, age and selected preoperative risk factors), stroke characteristics (side, stroke volume and existing mass effect) and surgical characteristics (size of the bone flap, initial complication rate, time to cranioplasty, complication rate following cranioplasty, type of implant, number of revision surgeries and mortality). Frequency of hydrocephalus development was 10% in our cohort. Patients who developed a hydrocephalus had an earlier time point of bone flap reimplantation compared to the control group (no hydrocephalus=164±104days, hydrocephalus=108±52days, p<0.05). Additionally, numbers of revision surgeries after cranioplasty was associated with hydrocephalus with a trend towards significance (p=0.08). Communicating hydrocephalus is frequent in patients with malignant middle cerebral artery infarction after decompressive hemicraniectomy. A later time point of cranioplasty might lead to a lower incidence of required shunting procedures in general as we could show in our patient cohort. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. [Successful outcome of a pregnancy with an extremely low fetal heart rate (34 bpm) due to isolated complete heart block--case report].

    PubMed

    Hamela-Olkowska, Anita; Dangel, Joanna; Miszczak-Knecht, Maria

    2009-09-01

    Isolated complete congenital heart block (CHB) in the majority of cases is associated with the presence of autoantibodies to SSA (Ro) and SSB (La) antigens in the maternal serum. The prognosis is less favorable in fetuses with a ventricular rate < 55bpm. We have reported a case of a fetus with an isolated non-autoimmune CHB with an extremely low ventricular rate (34bpm) in which the outcome was favorable. In the neonate the non-compaction of the myocardium was diagnosed.

  5. [Decompressive craniectomy in traumatic brain injury and malignant brain infarction].

    PubMed

    Greiner, Christoph

    2008-10-01

    High intracranial pressure (ICP) is the most frequent cause of death and disability after severe traumatic brain injury and malignant cerebral infarction. After failure of general therapeutic maneuvers and first line therapies, "second tier" therapies have to be considered. Decompressive craniectomy is an advanced treatment option for controlling intracranial pressure (ICP). In this review indications and techniques of decompressive craniectomy are described and current literature is discussed. The author concludes that decompressive craniectomy is no routine, but should be considered in individual cases.

  6. Relationship between peripheral nerve decompression and gain of pedal sensibility and balance in patients with peripheral neuropathy.

    PubMed

    Ducic, Ivica; Taylor, Nathan S; Dellon, A Lee

    2006-02-01

    This was an initial exploratory study to determine if decompression of the 4 medial ankle tunnels (neurolysis of the tibial, medial and lateral plantar, and calcaneal nerves) could lead to improved foot sensibility, increased proprioception and balance, and decreased falls in a population of patients with impaired lower extremity sensation. Fourteen patients with peripheral neuropathy were included in this study. Seventy-one percent of patients were females. Average age was 67 years. All patients were evaluated preoperatively and postoperatively to assess their lower extremity sensibility, as well as their ability to stand still, maintaining their balance with their eyes open and then closed, which is defined as "sway." Lower extremity sensibility was measured with the Pressure-Specified Sensory Device (PSSD), which evaluates 1- and 2-point discrimination for the pulp of the big toe and medial heel. The MatScan Measurement System measured each patient's sway. Neuropathy was the result of diabetes in 72% of patients, a combination of diabetes and hypothyroidism in 7%, chemotherapy in 7%, and idiopathic in 14%. Eight patients underwent peripheral nerve decompression on 1 lower extremity, whereas 6 patients underwent bilateral lower extremity peripheral nerve decompression. Mean toe and heel sensibility improved 9% and 7%, respectively, in the unilateral group, whereas the bilateral group experienced an improvement in mean toe and heel sensibility of 42% (P = 0.02) and 32%, respectively. Preoperative and postoperative sway comparison in the unilateral group revealed a reduction in sway with eyes open and eyes closed by 5% and 31%, respectively. Comparison of preoperative and postoperative sway in the bilateral group showed a reduction with eyes open and eyes closed by 23% and 145% (P = 0.05), respectively. This initial study suggests that there may be benefit from bilateral lower extremity peripheral nerve decompression in helping improve pedal sensibility and balance

  7. Comparison of clinical outcomes between laminoplasty, posterior decompression with instrumented fusion, and anterior decompression with fusion for K-line (-) cervical ossification of the posterior longitudinal ligament.

    PubMed

    Koda, Masao; Mochizuki, Makondo; Konishi, Hiroaki; Aiba, Atsuomi; Kadota, Ryo; Inada, Taigo; Kamiya, Koshiro; Ota, Mitsutoshi; Maki, Satoshi; Takahashi, Kazuhisa; Yamazaki, Masashi; Mannoji, Chikato; Furuya, Takeo

    2016-07-01

    The K-line, which is a virtual line that connects the midpoints of the anteroposterior diameter of the spinal canal at C2 and C7 in a plain lateral radiogram, is a useful preoperative predictive indicator for sufficient decompression by laminoplasty (LMP) for ossification of the posterior longitudinal ligament (OPLL). K-line is defined as (+) when the peak of OPLL does not exceed the K-line, and is defined as (-) when the peak of OPLL exceeds the K-line. For patients with K-line (-) OPLL, LMP often results in poor outcome. The aim of the present study was to compare the clinical outcome of LMP, posterior decompression with instrumented fusion (PDF) and anterior decompression and fusion (ADF) for patients with K-line (-) OPLL. The present study included patients who underwent surgical treatment including LMP, PDF and ADF for K-line (-) cervical OPLL. We retrospectively compared the clinical outcome of those patients in terms of Japanese Orthopedic Association score (JOA score) recovery rate. JOA score recovery rate was significantly higher in the ADF group compared with that in the LMP group and the PDF group. The JOA score recovery rate in the PDF group was significantly higher than that in the LMP group. LMP should not be used for K-line (-) cervical OPLL. ADF is one of the suitable surgical treatments for K-line (-) OPLL. Both ADF and PDF are applicable for K-line (-) OPLL according to indications set by each institute and surgical decisions.

  8. Microscopic lumbar spinal stenosis decompression: is surgical education safe?

    PubMed

    Joswig, Holger; Hock, Carolin; Hildebrandt, Gerhard; Schaller, Karl; Stienen, Martin N

    2016-02-01

    Acquiring operative skills in the course of a structured neurosurgery residency training program is vital to safely operating on patients autonomously upon board certification. We tested the hypothesis that the complication rates and outcome of microscopic lumbar spinal stenosis (LSS) decompression done by supervised residents are not inferior to those of board-certified faculty neurosurgeons (BCFNs). Retrospective single-center study performed at a Swiss teaching hospital comparing consecutive patients undergoing surgery for LSS by a supervised neurosurgery resident (teaching cases) to a consecutive series of patients operated on by a BCFN (non-teaching cases). The primary endpoint was occurrence of complications during surgery. Secondary endpoints were patients' clinical outcomes 4 weeks after surgery, categorized into a binary responder and non-responder variable, occurrence of postoperative complications, need for re-do surgery, and clinical outcome until the last follow-up (FU). In a total of n = 471 operations, n = 194 (41.2 %) were teaching cases and n = 277 (58.8 %) non-teaching cases. A longer operation time (single-level procedures: mean 100.0 vs. 83.2 min, p < 0.001) was recorded for teaching cases, while estimated blood loss was equal (single-level procedures: mean 109.9 vs. 117.0 ml, p = 0.409). In multivariate analysis, supervised residents were as likely as BCFNs to have an intraoperative complication (OR 0.92, 95 % CI 0.41-2.04, p = 0.835). They were as likely as BCFNs to achieve a favorable 4-week response to surgery (OR 1.82, 95 % CI 0.79-4.15, p = 0.155). Until final FU, the likelihood for patients in the teaching group to suffer from postoperative complications (OR 1.07, 95 % CI 0.46-2.49, p = 0.864) or require re-do surgery (OR 0.68, 95 % CI 0.31-1.52, p = 0.358) was similar to that of the non-teaching group. Complication rates and short- and mid-term outcomes following LSS decompression were comparable for

  9. Arthroscopic subacromial decompression in the treatment of full thickness rotator cuff tears: a 3- to 6-year follow-up.

    PubMed

    Zvijac, J E; Levy, H J; Lemak, L J

    1994-10-01

    Arthroscopic subacromial decompression has become an accepted treatment for patients with impingement syndrome; however, its use for full thickness rotator cuff tears continues to be controversial. The purpose of this study is to determine if the results of arthroscopic subacromial decompression alone for full thickness rotator cuff tears deteriorate at long-term follow-up. We reevaluated all 25 patients with full thickness rotator cuff tears who underwent arthroscopic subacromial decompression from our original study group. Based on the University of California at Los Angeles shoulder rating, 68% of patients were rated as excellent or good at the present mean follow-up of 45.8 months (range 36-72 months). This represents a significant decrease from our initial report of 84% satisfactory results at a mean follow-up of 24.6 months. There was a significant decrease in ratings with regard to pain and function; however, no significant deterioration was noted with regard to motion and strength. Two additional patients required open rotator cuff repair since the time of initial follow-up for a total of six. Large and massive rotator cuff tears fared worse over time as compared with small and moderate size tears. Although 1- to 3-year results of arthroscopic subacromial decompression and rotator cuff debridement were favorable, the long-term follow-up demonstrates deterioration of results. We therefore cannot support the use of decompression and debridement alone in the treatment of repairable full thickness rotator cuff tears.

  10. [Different posterior decompression for patients with spinal canal stenosis in the upper thoracic and cervical spine].

    PubMed

    Yao, Y Z; Yin, R F; Huang, J; Liu, D L; Zang, H

    2016-07-05

    To retrospectively investigate the clinical manifestation of patients with spinal stenosis in the upper thoracic and cervical spine by posterior decompression in different ways. From January 2010 to December 2015, 18 patients of that complicated phenomenon were studied in Department of Orthopaedic Surgery, China-Japan Union Hospital, Jilin University.Ten patients received one-stage combined decompression (group A); while the other 8 received multi-stage posterior decompression(group B). The Visual analogue scale (JOA), thoracic Cobb and range of motion(ROM) were compared. No statistically significant inter-group difference existed in preoperative JOA score[(9.1±2.6)vs (9.1±2.2)]and postoperative JOA score[(15.4±1.2)vs(13.8±4.5)], but the mean recovery rate of nerve function of group A(79%±15%)is better than that of group B(69%±34%). All the approaches are effective for the treatment of patients with spinal stenosis in the upper thoracic and cervical spine, while one-staged combined decompression was better than double-staged operation.

  11. Enterobacter cloacae infection after anterior cervical decompression and fusion: case study and literature review

    PubMed Central

    Wang, Hongli; Wang, Lixun; Yang, Yong; Lu, Feizhou; Ma, Xiaosheng; Xia, Xinlei; Jiang, Jianyuan

    2015-01-01

    Wound infection after anterior cervical decompression and fusion can lead to disastrous consequences despite a low incidence rate. Although Gram-positive bacteria such as Staphylococcus aureus are the most common pathogenic bacteria, some rare bacteria such as conditional pathogenic bacteria may also result in such a condition. To the best of our knowledge, E. cloacae-caused acute infection after anterior cervical decompression and fusion has not been reported. Here, we report an E. cloacae-caused acute infection after anterior vertical decompression and fusion. This infection was eventually controlled by virtue of an early diagnosis and the correspondingly-adopted anti-infection, internal fixation removal, and drainage treatments. Exploring the reasons underlying acute infection after anterior cervical decompression and fusion caused by rare bacteria, particularly E. cloacae, by analyzing this case was the basic therapeutic principle in this study. We believe that the therapeutic principle for E. cloacae-caused wound infection after anterior cervical internal fixation is basically consistent with that for other bacterium-caused wound infections after spinal internal fixation. Sufficient drainage, the adoption of sensitive antibacterials, and internal fixation removal as early as possible when necessary are the essential measures in infection control. PMID:26064234

  12. One-day nasogastric tube decompression after distal gastrectomy: a prospective randomized study.

    PubMed

    Kimura, Yutaka; Yano, Hiroshi; Iwazawa, Takashi; Fujita, Junya; Fujita, Shoichiro; Yamamoto, Kazuyoshi; Yasuda, Takushi

    2017-09-01

    Many surgeons in Japan use 1-day nasogastric tube (NGT) decompression after gastrectomy as a standard procedure. This prospective randomized study aimed to define whether 1-day NGT decompression is necessary after distal gastrectomy. The subjects were 233 patients with gastric cancer, randomized into two groups immediately after distal gastrectomy: one group received 1-day NGT decompression (NGT group, n = 119) and the other did not (no-NGT group, n = 114). The primary outcome measure was postoperative surgery-related and respiratory complications, whereas secondary measures were the postoperative course to recovery and patient complaints. The incidence of surgery-related complications did not differ significantly between the NGT and no-NGT groups (21.0 and 19.2%, respectively; p = 0.87). The rate of respiratory complications was 6.7% in the NGT group and 7.0% in the no-NGT group (p > 0.99). The time to passage of first flatus and the postoperative hospital stay did not differ between the groups. Twenty-five patients in the NGT group and none in the no-NGT group complained of nasopharyngeal discomfort (p < 0.0001). Considering the physical discomfort caused by the NGT, we believe that routine 1-day NGT decompression is unnecessary after distal gastrectomy.

  13. [Ethmoidectomy and orbital decompression in endocrine ophthalmopathy].

    PubMed

    Richter, W C; Kley, W; Buschmann, W

    1984-07-01

    23 orbita decompression operations were performed in patients suffering from endocrine exophthalmos (Grave's disease) after normalization of thyroid metabolism and systemic corticoid therapy remained unsuccessful. We developed a modification of an external ethmoidectomy. The lamina of the middle nasal concha is carefully preserved, any opening to the nasal cavity is closed. Flap door incisions of the periorbita complete this procedure. Results are good and were followed up for a period of 30 months. The operation resulted in prompt restitution of normal eye position with fast normalization of visual acuity and field. Squint surgery was done in addition.

  14. Analytic gain in probabilistic decompression sickness models.

    PubMed

    Howle, Laurens E

    2013-11-01

    Decompression sickness (DCS) is a disease known to be related to inert gas bubble formation originating from gases dissolved in body tissues. Probabilistic DCS models, which employ survival and hazard functions, are optimized by fitting model parameters to experimental dive data. In the work reported here, I develop methods to find the survival function gain parameter analytically, thus removing it from the fitting process. I show that the number of iterations required for model optimization is significantly reduced. The analytic gain method substantially improves the condition number of the Hessian matrix which reduces the model confidence intervals by more than an order of magnitude. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Gastrointestinal decompression after excision and anastomosis of lower digestive tract

    PubMed Central

    Lei, Wen-Zhang; Zhao, Gao-Ping; Cheng, Zhong; Li, Ka; Zhou, Zong-Guang

    2004-01-01

    AIM: To discuss the clinical significance of postoperative gastrointestinal decompression in operation on lower digestive tract. METHODS: Three hundred and sixty-eight patients with excision and anastomosis of lower digestive tract were divided into two groups, i.e. the group with postoperative gastrointestinal decompression and the group without postoperative gastrointestinal decompression. Clinical therapeutic outcome and incidence of complication were compared between two groups. Furthermore, an investigation on application of gastrointestinal decompression was carried out among 200 general surgeons. RESULTS: The volume of gastric juice in decompression group was about 200 mL every day after operation. Both groups had a lower girth before operation than every day after operation. No difference in length of the first passage of gas by anus and defecation after operation was found between two groups. The overall incidence of complications was obviously higher in decompression group than in non-decompression group (28% vs 8.2%, P < 0.001). The incidence of pharyngolaryngitis was up to 23.1%. There was also no difference between two groups regarding the length of hospitalization after operation. The majority (97.5%) of general surgeons held that gastrointestinal decompression should be placed till passage of gas by anus, and only 2.5% of surgeons thought that gastrointestinal decompression should be placed for 2-3 d before passage of gas by anus. Nobody (0%) deemed it unnecessary for placing gastrointestinal compression after operation. CONCLUSION: Application of gastrointestinal decompression after excision and anastomosis of lower digestive tract cannot effectively reduce gastrointestinal tract pressure and has no obvious effect on preventing postoperative complications. On the contrary, it may increase the incidence of pharyngolaryngitis and other complications. Therefore, it is more beneficial to the recovery of patients without undergoing gastrointestinal

  16. [Evaluation of heart impact in the 100 m extreme intensity sport using near-infrared non-invasive muscle oxygen detecting device and sports heart rate detection technology].

    PubMed

    Wang, Pei-Yong; Long, Fei-Xiao; Fu, Lan-Ying; Li, Yue; Ding, Hai-Shu; Qu, An-Lian; Zhou, Xiao-Ping

    2010-02-01

    Using continuous two wavelength near-infrared technology to detect the variation in the consistency of oxygen hemoglobin in the muscle and the sports heart rate wireless real time collection technology, we devised the real time muscle tissue oxygenation and instantaneous heart rate experiment scheme and implemented it for the process of the 100 m run with two parameters given simultaneously. The experiment shows that the concentration of the oxygen hemoglobin in the muscle tissue continues decreasing after the end of the 100 m run, and the time interval between the moment when the concentration of the oxygen hemoglobin attains the minimum value and the moment when the athletes finish the 100 m run is (6.65 +/- 1.10) sec; while the heart rate continues increasing after the end of the 100 m run, and the time interval between the moment when the heart rate attains the maximum value and the moment when the athletes finish the 100 m run is (8.00 +/- 1.57) sec. The results show that the two wavelength near-infrared tissue oxygenation detection technology and the sports heart rate real time collection equipment can accurately measure the sports tissue oxygenation and the heart rate in the extreme intensity sport, and reveal the process of muscle oxygen transportation and consumption and its dynamic character with the heart rate in the extreme intensity sport.

  17. Microvascular decompression for elderly patients with trigeminal neuralgia.

    PubMed

    Phan, Kevin; Rao, Prashanth J; Dexter, Mark

    2016-07-01

    Microvascular decompression (MVD) has been demonstrated to be an excellent surgical treatment approach in younger patients with trigeminal neuralgia (TN). However, it is not clear whether there are additional morbidity and mortality risks for MVD in the elderly population. We performed a systematic literature review using six electronic databases for studies that compared outcomes for MVD for TN in elderly (cut-off ⩾60, 65, 70years) versus younger populations. Outcomes examined included success rate, deaths, strokes, thromboembolism, meningitis, cranial nerve deficits and cerebrospinal fluid leaks. There were 1524 patients in the elderly cohort and 3488 patients in the younger cohort. There was no significant difference in success rates in elderly versus younger patients (87.5% versus 84.8%; P=0.47). However, recurrence rates were lower in the elderly (11.9% versus 15.6%; P=0.03). The number of deaths in the elderly cohort was higher (0.9% versus 0.1%; P=0.003). Rates of stroke (2.5% versus 1%) and thromboembolism (1.1% versus 0%) were also higher for elderly TN patients. No differences were found for rates of meningitis, cranial nerve deficits or cerebrospinal fluid leak. MVD remains an effective and reasonable strategy in the elderly population. There is evidence to suggest that rates of complications such as death, stroke, and thromboembolism may be significantly higher in the elderly population. The presented results may be useful in the decision-making process for MVD in elderly patients with TN.

  18. Facial nerve decompression surgery using bFGF-impregnated biodegradable gelatin hydrogel in patients with Bell palsy.

    PubMed

    Hato, Naohito; Nota, Jumpei; Komobuchi, Hayato; Teraoka, Masato; Yamada, Hiroyuki; Gyo, Kiyofumi; Yanagihara, Naoaki; Tabata, Yasuhiko

    2012-04-01

    Basic fibroblast growth factor (bFGF) promotes the regeneration of denervated nerves. The aim of this study was to evaluate the regeneration-facilitating effects of novel facial nerve decompression surgery using bFGF in a gelatin hydrogel in patients with severe Bell palsy. Prospective clinical study. Tertiary referral center. Twenty patients with Bell palsy after more than 2 weeks following the onset of severe paralysis were treated with the new procedure. The facial nerve was decompressed between tympanic and mastoid segments via the mastoid. A bFGF-impregnated biodegradable gelatin hydrogel was placed around the exposed nerve. Regeneration of the facial nerve was evaluated by the House-Brackmann (H-B) grading system. The outcomes were compared with the authors' previous study, which reported outcomes of the patients who underwent conventional decompression surgery (n = 58) or conservative treatment (n = 43). The complete recovery (H-B grade 1) rate of the novel surgery (75.0%) was significantly better than the rate of conventional surgery (44.8%) and conservative treatment (23.3%). Every patient in the novel decompression surgery group improved to H-B grade 2 or better even when undergone between 31 and 99 days after onset. Advantages of this decompression surgery are low risk of complications and long effective period after onset of the paralysis. To the authors' knowledge, this is the first clinical report of the efficacy of bFGF using a new drug delivery system in patients with severe Bell palsy.

  19. Submarine tower escape decompression sickness risk estimation.

    PubMed

    Loveman, G A M; Seddon, E M; Thacker, J C; Stansfield, M R; Jurd, K M

    2014-01-01

    Actions to enhance survival in a distressed submarine (DISSUB) scenario may be guided in part by knowledge of the likely risk of decompression sickness (DCS) should the crew attempt tower escape. A mathematical model for DCS risk estimation has been calibrated against DCS outcome data from 3,738 exposures of either men or goats to raised pressure. Body mass was used to scale DCS risk. The calibration data included more than 1,000 actual or simulated submarine escape exposures and no exposures with substantial staged decompression. Cases of pulmonary barotrauma were removed from the calibration data. The calibrated model was used to estimate the likelihood of DCS occurrence following submarine escape from the United Kingdom Royal Navy tower escape system. Where internal DISSUB pressure remains at - 0.1 MPa, escape from DISSUB depths < 200 meters is estimated to have DCS risk < 6%. Saturation at raised DISSUB pressure markedly increases risk, with > 60% DCS risk predicted for a 200-meter escape from saturation at 0.21 MPa. Using the calibrated model to predict DCS for direct ascent from saturation gives similar risk estimates to other published models.

  20. Colonic Fermentation Promotes Decompression sickness in Rats

    PubMed Central

    de Maistre, Sébastien; Vallée, Nicolas; Gempp, Emmanuel; Lambrechts, Kate; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

    2016-01-01

    Massive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body’s H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental dive, 93 fasting rats were force-fed, half of them with mannitol and the other half with water. Exhaled hydrogen was measured before and after force-feeding. Following the hyperbaric exposure, we looked for signs of DCS. A higher incidence of DCS was found in rats force-fed with mannitol than in those force-fed with water (80%, [95%CI 56, 94] versus 40%, [95%CI 19, 64], p < 0.01). In rats force-fed with mannitol, metronidazole pretreatment reduced the incidence of DCS (33%, [95%CI 15, 57], p = 0.005) at the same time as it inhibited colonic fermentation (14 ± 35 ppm versus 118 ± 90 ppm, p = 0.0001). Pre-diveingestion of mannitol increased the incidence of DCS in fasting rats when colonic fermentation peaked during the decompression phase. More generally, colonic fermentation in rats on a normal diet could promote DCS through endogenous hydrogen production. PMID:26853722

  1. Optic Nerve Decompression through a Supraorbital Approach

    PubMed Central

    Rigante, Luigi; Evins, Alexander I.; Berra, Luigi V.; Beer-Furlan, André; Stieg, Philip E.; Bernardo, Antonio

    2015-01-01

    Objective We propose a stepwise decompression of the optic nerve (ON) through a supraorbital minicraniotomy and describe the surgical anatomy of the ON as seen through this approach. We also discuss the clinical applications of this approach. Methods Supraorbital approaches were performed on 10 preserved cadaveric heads (20 sides). First, 3.5-cm skin incisions were made along the supraciliary arch from the medial third of the orbit and extended laterally. A 2 × 3-cm bone flap was fashioned and extradural dissections were completed. A 180-degree unroofing of the ON was achieved, and the length and width of the proximal and distal portions of the optic canal (OC) were measured. Results The supraorbital minicraniotomy allowed for identification of the anterior clinoid process and other surgical landmarks and adequate drilling of the roof of the OC with a comfortable working angle. A 25-degree contralateral head rotation facilitated visualization of the ON. Conclusion The supraorbital approach is a minimally invasive and cosmetically favorable alternative to more extended approaches with longer operative times used for the management of ON decompression in posttraumatic or compressive optic neuropathy from skull base pathologies extending into the OC. The relative ease of this approach provides a relatively short learning curve for developing neurosurgeons. PMID:26225308

  2. Optic Nerve Decompression through a Supraorbital Approach.

    PubMed

    Rigante, Luigi; Evins, Alexander I; Berra, Luigi V; Beer-Furlan, André; Stieg, Philip E; Bernardo, Antonio

    2015-06-01

    Objective We propose a stepwise decompression of the optic nerve (ON) through a supraorbital minicraniotomy and describe the surgical anatomy of the ON as seen through this approach. We also discuss the clinical applications of this approach. Methods Supraorbital approaches were performed on 10 preserved cadaveric heads (20 sides). First, 3.5-cm skin incisions were made along the supraciliary arch from the medial third of the orbit and extended laterally. A 2 × 3-cm bone flap was fashioned and extradural dissections were completed. A 180-degree unroofing of the ON was achieved, and the length and width of the proximal and distal portions of the optic canal (OC) were measured. Results The supraorbital minicraniotomy allowed for identification of the anterior clinoid process and other surgical landmarks and adequate drilling of the roof of the OC with a comfortable working angle. A 25-degree contralateral head rotation facilitated visualization of the ON. Conclusion The supraorbital approach is a minimally invasive and cosmetically favorable alternative to more extended approaches with longer operative times used for the management of ON decompression in posttraumatic or compressive optic neuropathy from skull base pathologies extending into the OC. The relative ease of this approach provides a relatively short learning curve for developing neurosurgeons.

  3. Colonic Fermentation Promotes Decompression sickness in Rats.

    PubMed

    de Maistre, Sébastien; Vallée, Nicolas; Gempp, Emmanuel; Lambrechts, Kate; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

    2016-02-08

    Massive bubble formation after diving can lead to decompression sickness (DCS). During dives with hydrogen as a diluent for oxygen, decreasing the body's H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. So we set out to investigate if colonic fermentation leading to endogenous hydrogen production promotes DCS in fasting rats. Four hours before an experimental dive, 93 fasting rats were force-fed, half of them with mannitol and the other half with water. Exhaled hydrogen was measured before and after force-feeding. Following the hyperbaric exposure, we looked for signs of DCS. A higher incidence of DCS was found in rats force-fed with mannitol than in those force-fed with water (80%, [95%CI 56, 94] versus 40%, [95%CI 19, 64], p < 0.01). In rats force-fed with mannitol, metronidazole pretreatment reduced the incidence of DCS (33%, [95%CI 15, 57], p = 0.005) at the same time as it inhibited colonic fermentation (14 ± 35 ppm versus 118 ± 90 ppm, p = 0.0001). Pre-diveingestion of mannitol increased the incidence of DCS in fasting rats when colonic fermentation peaked during the decompression phase. More generally, colonic fermentation in rats on a normal diet could promote DCS through endogenous hydrogen production.

  4. Transosseous Access for Decompression of an Obstructed Pelvic Kidney

    SciTech Connect

    Kennedy, Peter T.; Goodacre, Brian W.; Wittich, Gerhard R.; Sonnenberg, Eric van

    2002-08-15

    We report a case of an obstructed pelvic kidney which was decompressed using a transosseous access route. The patient presented with obstructive uropathy and fever, necessitating decompression. Initial access was gained to the kidney by traversing the ilium, allowing subsequent retrograde placement of a double-Jureteric catheter.

  5. A New Measure of Decompression Sickness in the Rat

    PubMed Central

    Wang, Qiong; Lambrechts, Kate; Mansourati, Jacques

    2014-01-01

    In this study we assessed the reliability of a tilting-board grip score as a measure of decompression sickness in rats. In experiments using a hyperbaric compression/decompression protocol, rats were observed for signs of decompression sickness and their grip strength measured on a tilting particle board hinged to a metal frame. Angles at which rats lost grip were converted to gravitational vectors. Decreased mean grip scores following decompression were fitted to a logistic regression model with strain, age, and weight. Decrease in grip score was significantly associated with observed decompression sickness (P = 0.0036). The log odds ratio for decompression sickness = 1.40 (decrease in grip score). In rats with no decrease in mean grip score there was a 50% probability of decompression sickness (pDCS). This increased steadily with decreases in mean grip score. A decrease of 0.3 had a 60% pDCS, a decrease of 0.6 had a 70% pDCS, and a decrease of 2.1 had a 95% pDCS. The tilting board grip score is a reliable measure of the probability of decompression sickness. PMID:24963469

  6. A new measure of decompression sickness in the rat.

    PubMed

    Buzzacott, Peter; Mazur, Aleksandra; Wang, Qiong; Lambrechts, Kate; Theron, Michael; Mansourati, Jacques; Guerrero, François

    2014-01-01

    In this study we assessed the reliability of a tilting-board grip score as a measure of decompression sickness in rats. In experiments using a hyperbaric compression/decompression protocol, rats were observed for signs of decompression sickness and their grip strength measured on a tilting particle board hinged to a metal frame. Angles at which rats lost grip were converted to gravitational vectors. Decreased mean grip scores following decompression were fitted to a logistic regression model with strain, age, and weight. Decrease in grip score was significantly associated with observed decompression sickness (P = 0.0036). The log odds ratio for decompression sickness = 1.40 (decrease in grip score). In rats with no decrease in mean grip score there was a 50% probability of decompression sickness (pDCS). This increased steadily with decreases in mean grip score. A decrease of 0.3 had a 60% pDCS, a decrease of 0.6 had a 70% pDCS, and a decrease of 2.1 had a 95% pDCS. The tilting board grip score is a reliable measure of the probability of decompression sickness.

  7. 21 CFR 884.5225 - Abdominal decompression chamber.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... is a hoodlike device used to reduce pressure on the pregnant patient's abdomen for the relief of... decompression chamber that was in commercial distribution before May 28, 1976, or that has, on or before... in commercial distribution before May 28, 1976. Any other abdominal decompression chamber shall have...

  8. [Osteoplastic decompressive craniotomy--indication and surgical technique].

    PubMed

    Mracek, J; Choc, M; Mracek, Z

    2010-02-01

    Decompressive craniotomy is usually carried out using decompressive craniectomy (osteoclastic decompressive craniotomy) when the bone flap is removed. In situations when the level of expansion does not call for decomopressive craniectomy, we do not remove the bone flap and we perform osteoplastic decompressive craniotomy. The indication is based on assessment and cross correlation of the following parameters: intracranial pressure,midline shift and the number of pathologies on CT, actual influence of antiedematous therapy, expected cerebral oedema progression and especially according to the size of the dural defect after duratomy. In the course of osteoplastic decompressive craniotomy, decompression is secured by the elevation of the unfixed bone flap during cerebral tissue expansion. After the oedema regression, the elevated bone flap spontaneously drops to its original position and is reattached. The danger of bone plate depression is eliminated with the use of a bevel bone cut using a Gigli saw. Osteoplastic decompressive craniotomy is an effective method of treating brain oedema when the degree of expansion does not require decompressive craniectomy.

  9. Management of Pelvic Chondroblastic Osteosarcoma after Urgent Spinal Decompression - A Report of 2 Cases

    PubMed Central

    Scudday, Travis Spencer; Danisa, Olumide Ayodele; Zuckerman, Lee Michael

    2016-01-01

    Introduction: Pelvic sarcoma presenting with neurologic symptoms is rare. Workup of neurological deficits, whether elective or emergent should address the possibility of a space occupying lesion including pelvic sarcoma. Poor biopsy technique and incomplete workup of musculoskeletal tumors results in misdiagnosis or major errors in 18% of biopsies. The sequelae of a suboptimal biopsy include local recurrence, a more extensive resection, or extremity amputation. Pelvic chondroblastic osteosarcoma presenting with neurological deficits has not been previously reported. We report two cases of chondroblastic osteosarcoma that were treated with urgent decompression of the lumbar spine due to neurologic symptoms. Case presentations: Our two cases, a 25 year old Hispanic female and 22 year old Hispanic male, both presented with neurologic changes due to a space occupying tumor in the lumbar spine and pelvis. Both underwent spinal decompression following incomplete workup. A repeat biopsy was required in both cases due to a questionable initial diagnosis. Once the diagnosis was confirmed, they underwent definitive resection and treatment that was more morbid due to the primary decompressions. Conclusion: We stress the importance of proper biopsy techniques as well as the need to complete a full preoperative staging workup prior to any surgical procedures involving musculoskeletal tumors. We review the current literature on lumbar chondroblastic osteosarcomas and review the issues surrounding biopsy of musculoskeletal tumors. Our cases underline the need for complete workup and correct biopsy techniques to ensure patients have the best chance at tumor free survival with minimal morbidity.

  10. Macrovascular decompression of the median nerve for posttraumatic neuralgic limb pain.

    PubMed

    Pabaney, Aqueel; Hervey-Jumper, Shawn L; Domino, Joseph; Maher, Cormac O; Yang, Lynda J S

    2013-09-01

    Neuropathic pain is rare in children, and few reports provide adequate guidelines for treatment. The authors describe the successful treatment of tardy neuropathic pain via macrovascular decompression in a 15-year-old boy who presented with progressive pain 11 years following trauma to the upper extremity that had required surgical repair of the brachial artery. Examination revealed mild chronic median and ulnar motor neuropathy as well as recent progressive lancinating pain and a Tinel sign at the prior scar. A soft tissue mass in the neurovascular bundle at the site of previous injury was noted on MRI. Surgical exploration demonstrated an altered anatomical relationship of the previously repaired brachial artery and the median nerve, resulting in pulsatile compression of the median nerve by the brachial artery. Neurolysis and decompression of the median nerve with physical separation from the brachial artery resulted in immediate pain relief. This is the first report of macrovascular decompression of a major peripheral nerve with complete symptom resolution. Noninvasive imaging together with a thorough history and physical examination can support identification of this potential etiology of peripheral neuralgic pain. Recognition and treatment of this uncommon problem may yield improved outcomes for children with neuropathic pain.

  11. [Results of decompressive-stabilizing procedures via unilateral approach in lumbar spinal stenosis].

    PubMed

    Krut'ko, A V

    2012-01-01

    Aim of this study was to investigate the capabilities, advantages and limitations of bilateral decompression via unilateral approach in decompressive-stabilizing procedures in patients with degenerative lumbar spine disease, and to develop the technology and its technical performance. The controlled study included 372 patients (age range was 27-74 years). All of them were operated due to clinical manifestation of lumbar spinal stenosis. The main group consisted of 44 patients who underwent bilateral decompression via unilateral approach with stabilization of involved segments. The control group included 328 patients who were operated using standard bilateral technique with stabilization. A total of 52 segments were treated in the first group and 351 in the second one. In all patients with neurogenic intermittent claudication symptoms relieved after decompressive-stabilizing surgery. Analysis of duration of surgery (considering 1 segment) demonstrated that less invasive technique requires as much time as conventional. However mean intraoperative blood loss in the first group was twice as low as the second. Neither patient from the first group required hemotransfusion while in the second group in 57 (17.4%) cases hemotransfusion was performed due to blood loss. In the early postoperative period in both groups intensity of pain (according to VAS) gradually decreased. Mean hospital stay was 9.9 +/- 3.1 day in the main group and 14.7 +/- 4.7 days in the control group. Bilateral spinal canal decompression via unilateral approach decreases surgical trauma, blood loss, complication rate and hospital stay. Postoperative results are comparable with conventional technique.

  12. Clopidogrel reduces the inflammatory response of lung in a rat model of decompression sickness.

    PubMed

    Bao, Xiao-Chen; Chen, Hong; Fang, Yi-Qun; Yuan, Heng-Rong; You, Pu; Ma, Jun; Wang, Fang-Fang

    2015-06-01

    Inflammation and platelet activation are critical phenomena in the setting of decompression sickness. Clopidogrel (Clo) inhibits platelet activation and may also reduce inflammation. The goal of this study was to investigate if Clo had a protective role in decompression sickness (DCS) through anti-inflammation way. Male Sprague-Dawley rats (n=111) were assigned to three groups: control+vehicle group, DCS+vehicle, DCS+Clo group. The experimental group received 50 mg/kg of Clo or vehicle for 3 days, then compressed to 1,600 kPa (150 msw) in 28 s, maintained at 150 msw for 242 s and decompressed to surface at 3m/s. In a control experiment, rats were also treated with vehicle for 3 days and maintained at atmospheric pressure for an equivalent period of time. Clinical assessment took place over a period of 30 min after surfacing. At the end, blood samples were collected for blood cells counts and cytokine detection. The pathology and the wet/dry ratio of lung tissues, immunohistochemical detection of lung tissue CD41 expression, the numbers of P-selectin positive platelets and platelet-leukocyte conjugates in blood were tested. We found that Clo significantly reduced the DCS mortality risk (mortality rate: 11/45 with Clo vs. 28/46 in the untreated group, P<0.01). Clo reduced the lung injury, the wet/dry ratio of lung, the accumulation of platelet and leukocyte in lung, the fall in platelet count, the WBC count, the numbers of activated platelets and platelet-leukocyte complexes in peripheral blood. It was concluded that Clo can play a protective role in decompression sickness through reducing post-decompression platelet activation and inflammatory process. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. How extreme are extremes?

    NASA Astrophysics Data System (ADS)

    Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro

    2016-04-01

    High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude

  14. Ambulation Increases Decompression Sickness in Spacewalk Simulations

    NASA Technical Reports Server (NTRS)

    Pollock, N. W.; Natoli, M. J.; Conkin, J.; Wessel, J. H., III; Gernhardt, M. L.

    2014-01-01

    Musculoskeletal activity has the potential to both improve and compromise decompression safety. Exercise enhances inert gas elimination during oxygen breathing prior to decompression (prebreathe), but it may also promote bubble nuclei formation (nucleation), which can lead to gas phase separation and bubble growth and increase the risk of decompression sickness (DCS). The timing, pattern and intensity of musculoskeletal activity and the level of tissue supersaturation may be critical to the net effect. Understanding the relationships is important to evaluate exercise prebreathe protocols and quantify decompression risk in gravity and microgravity environments. Data gathered during NASA's Prebreathe Reduction Program (PRP) studies combined oxygen prebreathe and exercise followed by low pressure (4.3 psi; altitude equivalent of 30,300 ft [9,235 m]) microgravity simulation to produce two protocols used by astronauts preparing for extravehicular activity. Both the Phase II/CEVIS (cycle ergometer vibration isolation system) and ISLE (in-suit light exercise) trials eliminated ambulation to more closely simulate the microgravity environment. The CEVIS results (35 male, 10 female) serve as control data for this NASA/Duke study to investigate the influence of ambulation exercise on bubble formation and the subsequent risk of DCS. METHODS Four experiments will replicate the CEVIS exercise-enhanced oxygen prebreathe protocol, each with a different exception. The first of these is currently underway. Experiment 1 - Subjects complete controlled ambulation (walking in place with fixed cadence and step height) during both preflight and at 4.3 psi instead of remaining nonambulatory throughout. Experiment 2 - Subjects remain non-ambulatory during the preflight period and ambulatory at 4.3 psi. Experiment 3 - Subjects ambulate during the preflight period and remain non-ambulatory at 4.3 psi. Experiment 4 - The order of heavy and light exercise employed in the CEVIS protocol is

  15. Developments in time-resolved high pressure x-ray diffraction using rapid compression and decompression

    SciTech Connect

    Smith, Jesse S.; Sinogeikin, Stanislav V.; Lin, Chuanlong; Rod, Eric; Bai, Ligang; Shen, Guoyin

    2015-07-15

    Complementary advances in high pressure research apparatus and techniques make it possible to carry out time-resolved high pressure research using what would customarily be considered static high pressure apparatus. This work specifically explores time-resolved high pressure x-ray diffraction with rapid compression and/or decompression of a sample in a diamond anvil cell. Key aspects of the synchrotron beamline and ancillary equipment are presented, including source considerations, rapid (de)compression apparatus, high frequency imaging detectors, and software suitable for processing large volumes of data. A number of examples are presented, including fast equation of state measurements, compression rate dependent synthesis of metastable states in silicon and germanium, and ultrahigh compression rates using a piezoelectric driven diamond anvil cell.

  16. A flexible cure rate model for spatially correlated survival data based on generalized extreme value distribution and Gaussian process priors.

    PubMed

    Li, Dan; Wang, Xia; Dey, Dipak K

    2016-09-01

    Our present work proposes a new survival model in a Bayesian context to analyze right-censored survival data for populations with a surviving fraction, assuming that the log failure time follows a generalized extreme value distribution. Many applications require a more flexible modeling of covariate information than a simple linear or parametric form for all covariate effects. It is also necessary to include the spatial variation in the model, since it is sometimes unexplained by the covariates considered in the analysis. Therefore, the nonlinear covariate effects and the spatial effects are incorporated into the systematic component of our model. Gaussian processes (GPs) provide a natural framework for modeling potentially nonlinear relationship and have recently become extremely powerful in nonlinear regression. Our proposed model adopts a semiparametric Bayesian approach by imposing a GP prior on the nonlinear structure of continuous covariate. With the consideration of data availability and computational complexity, the conditionally autoregressive distribution is placed on the region-specific frailties to handle spatial correlation. The flexibility and gains of our proposed model are illustrated through analyses of simulated data examples as well as a dataset involving a colon cancer clinical trial from the state of Iowa.

  17. Arterial gas emboli in altitude-induced decompression sickness

    NASA Technical Reports Server (NTRS)

    Pilmanis, Andrew A.; Olson, Robert M.

    1993-01-01

    Exposure to high altitudes can result in the evolved-gas condition referred to as decompression sickness (DCS). Ultrasonic monitoring techniques have clearly demonstrated the presence of venous gas emboli (VGE) during decompression. Although important to DCS research and our understanding of the physiological mechanisms of this condition, Venus gas emboli have not been considered clinically hazardous, unless in extreme numbers. Arterial gas emboli (AGE), on the other hand, are generally viewed with great concern. Arterial gas emboli can enter the cerebral arterial circulation and arrest blood flow resulting in potentially serious injury. Left ventricular gas emboli were observed with echo imaging in five volunteer subjects during exposure to simulated altitude. These serendipitous findings occurred during altitude exposure under 3 separate research protocols involving 79 subject exposures. The voluntary, fully informed consent of the subjects used in this research was obtained as required by AFR 169-3. A Hewlett-Packard SONOS 1000 Echo Imaging System was used to monitor for precordial gas emboli. The improved resolution of the SONOS 1000 appears to account for these new findings. Four subjects had high incidence DCS and VGE during previous research flights. One subject only had one flight. The altitudes and AGE onset times for the five cases were: (1) 25,500 ft/2:23, (2) 29,000 ft/0:27, (3) 19,500 ft/3:49, (4) 29,500 ft/3:15, and (5) 29,500 ft/1:31. In all five cases, at the time of AGE onset, the VGE scores were high from all monitored locations. Four of the cases were symptomatic at the time of AGE onset (pain and skin mottling). No cerebral manifestations were observed. All subjects were immediately recompressed to ground level and successfully treated with 2 hours of post-breathing or with hyperbaric oxygen therapy. In conclusion, previously undetected AGE were demonstrated--with and without DCS symptoms--during exposure to altitude. It appears that this gas

  18. Arterial gas emboli in altitude-induced decompression sickness

    NASA Technical Reports Server (NTRS)

    Pilmanis, Andrew A.; Olson, Robert M.

    1993-01-01

    Exposure to high altitudes can result in the evolved-gas condition referred to as decompression sickness (DCS). Ultrasonic monitoring techniques have clearly demonstrated the presence of venous gas emboli (VGE) during decompression. Although important to DCS research and our understanding of the physiological mechanisms of this condition, Venus gas emboli have not been considered clinically hazardous, unless in extreme numbers. Arterial gas emboli (AGE), on the other hand, are generally viewed with great concern. Arterial gas emboli can enter the cerebral arterial circulation and arrest blood flow resulting in potentially serious injury. Left ventricular gas emboli were observed with echo imaging in five volunteer subjects during exposure to simulated altitude. These serendipitous findings occurred during altitude exposure under 3 separate research protocols involving 79 subject exposures. The voluntary, fully informed consent of the subjects used in this research was obtained as required by AFR 169-3. A Hewlett-Packard SONOS 1000 Echo Imaging System was used to monitor for precordial gas emboli. The improved resolution of the SONOS 1000 appears to account for these new findings. Four subjects had high incidence DCS and VGE during previous research flights. One subject only had one flight. The altitudes and AGE onset times for the five cases were: (1) 25,500 ft/2:23, (2) 29,000 ft/0:27, (3) 19,500 ft/3:49, (4) 29,500 ft/3:15, and (5) 29,500 ft/1:31. In all five cases, at the time of AGE onset, the VGE scores were high from all monitored locations. Four of the cases were symptomatic at the time of AGE onset (pain and skin mottling). No cerebral manifestations were observed. All subjects were immediately recompressed to ground level and successfully treated with 2 hours of post-breathing or with hyperbaric oxygen therapy. In conclusion, previously undetected AGE were demonstrated--with and without DCS symptoms--during exposure to altitude. It appears that this gas

  19. Effects of He-O2 Breathing during Experimental Decompression Sickness Following Air Dives

    DTIC Science & Technology

    1987-03-01

    ventilator volume or rate was made during the experiment. The oxygen content of the He-0 2 mixture used in the He-Or group was measured using a...e ne modifia pas ces rdponses. mats la respiratton de He-O? produtst une augmentation de 11% dans Ia rdsistance vasculaire pulmonaire (RVP). Chez 3...d’une plong~e A F’air peut aggraver l’obstruction vasculaire pulmonaire. plongde hdlium-oxygtne maladie de decompression suffocation embolie gazeuse

  20. Early Decompression of Acute Subdural Hematoma for Postoperative Neurological Improvement: A Single Center Retrospective Review of 10 Years

    PubMed Central

    Oh, Chang Hyun; Shim, Yu Shik; Hyun, Dongkeun; Park, Hyeonseon; Kim, Eunyoung

    2016-01-01

    Objective This study was conducted to investigate survival related factors, as well as to evaluate the effects of early decompression on acute subdural hematoma (ASDH). Methods We retrospectively reviewed cases of decompressive craniectomy (DC) for decade. In total, 198 cases of DC involved ASDH were available for review, and 65 cases were excluded due to missing data on onset time and a delayed operation after closed observation with medical care. Finally, 133 cases of DC with ASDH were included in this study, and various factors including the time interval between trauma onset and operation were evaluated. Results In the present study, survival rate after DC in patients with ASDH was shown to be related to patient age (50 years old, p=0.012), brain compression ratio (p=0.042) and brain stem compression (p=0.020). Sex, preoperative mental status, and time interval between trauma onset and operation were not related with survival rate. Among those that survived (n=78), improvements in Glasgow Coma Scale (GCS) score of more than three points, compared to preoperative measurement, were more frequently observed among the early (less than 3 hours between trauma onset and operation) decompressed cases (p=0.013). However, improvements of more than 4 or 5 points on the GCS were not affected by early decompression. Conclusion Early decompression of ASDH was not correlated with survival rate, but was related with neurological improvement (more than three points on the GCS). Accordingly, early decompression in ASDH, if indicated, may be of particular benefit. PMID:27182496

  1. Threshold altitude resulting in decompression sickness

    NASA Technical Reports Server (NTRS)

    Kumar, K. V.; Waligora, James M.; Calkins, Dick S.

    1990-01-01

    A review of case reports, hypobaric chamber training data, and experimental evidence indicated that the threshold for incidence of altitude decompression sickness (DCS) was influenced by various factors such as prior denitrogenation, exercise or rest, and period of exposure, in addition to individual susceptibility. Fitting these data with appropriate statistical models makes it possible to examine the influence of various factors on the threshold for DCS. This approach was illustrated by logistic regression analysis on the incidence of DCS below 9144 m. Estimations using these regressions showed that, under a noprebreathe, 6-h exposure, simulated EVA profile, the threshold for symptoms occurred at approximately 3353 m; while under a noprebreathe, 2-h exposure profile with knee-bends exercise, the threshold occurred at 7925 m.

  2. Automatic decompression device for internal combustion engine

    SciTech Connect

    Tsumiyama, Y.

    1986-10-07

    A decompression device is described for an internal combustion engine comprising: a holder secured to a camshaft supporting cams for controlling suction and exhaust valves of the engine, the cams having a contour and the holder having secured thereto a first cylindrical pin and a stopper pin; engine speed-responsive means including a first centrifugal weight supported by the holder for pivotal movement about the first pin and a second centrifugal weight supported on the first centrifugal weight for pivotal movement about a second pin having an axis parallel to the camshaft; cam means including a cylindrical pillar disposed on the second weight radially inwardly of the second pin and extending axially of the camshaft toward the cams for engagement with a valve operating member associated with one of the cams; and tension spring means mounted between the first centrifugal weight and the second centrifugal for moving the weights between a first position and a second position.

  3. Threshold altitude resulting in decompression sickness

    NASA Technical Reports Server (NTRS)

    Kumar, K. V.; Waligora, James M.; Calkins, Dick S.

    1990-01-01

    A review of case reports, hypobaric chamber training data, and experimental evidence indicated that the threshold for incidence of altitude decompression sickness (DCS) was influenced by various factors such as prior denitrogenation, exercise or rest, and period of exposure, in addition to individual susceptibility. Fitting these data with appropriate statistical models makes it possible to examine the influence of various factors on the threshold for DCS. This approach was illustrated by logistic regression analysis on the incidence of DCS below 9144 m. Estimations using these regressions showed that, under a noprebreathe, 6-h exposure, simulated EVA profile, the threshold for symptoms occurred at approximately 3353 m; while under a noprebreathe, 2-h exposure profile with knee-bends exercise, the threshold occurred at 7925 m.

  4. Transcranial Doppler ultrasound and the etiology of neurologic decompression sickness during altitude decompression

    NASA Technical Reports Server (NTRS)

    Norfleet, W. T.; Powell, M. R.; Kumar, K. Vasantha; Waligora, J.

    1993-01-01

    The presence of gas bubbles in the arterial circulation can occur from iatrogenic mishaps, cardiopulmonary bypass devices, or following decompression, e.g., in deep-sea or SCUBA diving or in astronauts during extravehicular activities (EVA). We have examined the pathophysiology of neurological decompression sickness in human subjects who developed a large number of small gas bubbles in the right side of the heart as a result of hypobaric exposures. In one case, gas bubbles were detected in the middle cerebral artery (MCA) and the subject developed neurological symptoms; a 'resting' patent foramen ovalae (PFO) was found upon saline contrast echocardiography. A PFO was also detected in another individual who developed Spencer Grade 4 precordial Doppler ultrasound bubbles, but no evidence was seen of arterialization of bubbles upon insonation of either the MCA or common carotid artery. The reason for this difference in the behavior of intracardiac bubbles in these two individuals is not known. To date, we have not found evidence of right-to-left shunting of bubbles through pulmonary vasculature. The volume of gas bubbles present following decompression is examined and compared with the number arising from saline contrast injection. The estimates are comparable.

  5. Effect of splenectomy on platelet activation and decompression sickness outcome in a rat model of decompression.

    PubMed

    Lambrechts, Kate; Pontier, Jean-Michel; Mazur, Aleksandra; Buzzacott, Peter; Goanvec, Christelle; Wang, Qiong; Theron, Michaël; Belhomme, Marc; Guerrero, François

    2014-09-01

    Splenic platelets have been recognized to have a greater prothrombotic potential than others platelets. We studied whether platelets released by splenic contraction could influence the severity and outcome of decompression sickness (DCS) and bubble-induced platelet activation. Sixteen, male Sprague-Dawley rats were randomly assigned to either a control or a splenectomized group. Both groups were compressed to 1,000 kPa (90 metres' sea water) for 45 min while breathing air before staged decompression (5 min at 200 kPa, 5 min at 160 kPa and 10 min at 130 kPa). The onset time of DCS symptoms and of death were recorded during a 60-min observation period post dive. Parameters measured were platelet factor 4 (PF4) for platelet activation, thiobarbituric acid reactive substances (TBARS) for oxidative stress status and Von Willebrand factor (VWf) for endothelial activation. There were no differences between the groups in DCS outcome or in PF4, TBARS and VWf concentrations. These results do not support that the spleen and its exchangeable platelet pool is involved in DCS pathogenesis in a rat model, invalidating the hypothesis that increased decompression-induced platelet aggregation could be influenced by splenic contraction and then play a role in DCS outcome.

  6. Decompression effects of erythritol on endolymphatic hydrops.

    PubMed

    Takeda, Taizo; Takeda, Setsuko; Kakigi, Akinobu; Nishioka, Rie; Nishimura, Masahiko

    2009-04-01

    The effect of the uptake of erythritol with and without the addition of pectin on fecal condition, p-OSM and p-AVP levels, and the endolymphatic volume was investigated to consider the possibility that erythritol is applicable as a therapeutic agent for Meniere's disease. Two experiments were performed using 100 female Hartley guinea pigs. Experiment 1 was designed to morphologically investigate the influence of the uptake of erythritol with or without the addition of pectin on the endolymphatic volume. Experiment 2 was designed to investigate changes in p-OSM and p-AVP levels after the uptake of erythritol with or without the addition of pectin. (1) Endolymphatic hydrops significantly decreased after the uptake of a mixture of erythritol and pectin, but did not decrease after the uptake of pectin or erythritol (p<0.001). (2) The fecal condition was muddy in all animals with the uptake of erythritol alone, but muddy or very soft feces were not observed in animals with a mixture of pectin and erythritol. p-AVP and p-OSM levels were significantly elevated in animals with the uptake of erythritol alone or a mixture of erythritol and pectin. Notably, the increase in p-AVP and p-OSM levels was significantly more evident in animals with the uptake of erythritol alone (one-way ANOVA, p<0.001). The addition of pectin almost completely suppressed erythritol-induced diarrhea. Consequently, the secondary elevation of p-AVP and p-OSM due to diarrhea was also reduced. The uptake of a mixture of erythritol and pectin markedly decompressed endolymphatic hydrops, although the uptake of erythritol alone did not. The difference of the decompression effect between animal groups with the uptake of erythritol alone and a mixture of erythritol and pectin seemed to be attributable to the difference of p-AVP levels due to diarrheal state.

  7. Decompression sickness ('the bends') in sea turtles.

    PubMed

    García-Párraga, D; Crespo-Picazo, J L; de Quirós, Y Bernaldo; Cervera, V; Martí-Bonmati, L; Díaz-Delgado, J; Arbelo, M; Moore, M J; Jepson, P D; Fernández, Antonio

    2014-10-16

    Decompression sickness (DCS), as clinically diagnosed by reversal of symptoms with recompression, has never been reported in aquatic breath-hold diving vertebrates despite the occurrence of tissue gas tensions sufficient for bubble formation and injury in terrestrial animals. Similarly to diving mammals, sea turtles manage gas exchange and decompression through anatomical, physiological, and behavioral adaptations. In the former group, DCS-like lesions have been observed on necropsies following behavioral disturbance such as high-powered acoustic sources (e.g. active sonar) and in bycaught animals. In sea turtles, in spite of abundant literature on diving physiology and bycatch interference, this is the first report of DCS-like symptoms and lesions. We diagnosed a clinico-pathological condition consistent with DCS in 29 gas-embolized loggerhead sea turtles Caretta caretta from a sample of 67. Fifty-nine were recovered alive and 8 had recently died following bycatch in trawls and gillnets of local fisheries from the east coast of Spain. Gas embolization and distribution in vital organs were evaluated through conventional radiography, computed tomography, and ultrasound. Additionally, positive response following repressurization was clinically observed in 2 live affected turtles. Gas embolism was also observed postmortem in carcasses and tissues as described in cetaceans and human divers. Compositional gas analysis of intravascular bubbles was consistent with DCS. Definitive diagnosis of DCS in sea turtles opens a new era for research in sea turtle diving physiology, conservation, and bycatch impact mitigation, as well as for comparative studies in other air-breathing marine vertebrates and human divers.

  8. Outcome of endoscopic decompression of retrocalcaneal bursitis

    PubMed Central

    Kondreddi, Vamsi; Gopal, R Krishna; Yalamanchili, Ranjith K

    2012-01-01

    Background: Posterior heel pain due to retrocalcaneal bursitis, is a disabling condition that responds well to the conventional methods of treatment. Patients who do not respond to conservative treatment may require surgical intervention. This study evaluates the outcome of endoscopic decompression of retrocalcaneal bursitis, with resection of posterosuperior eminence of the calcaneum. Materials and Methods: This present study included 25 heels from 23 consecutive patients with posterior heel pain, who did not respond to conservative treatment and underwent endoscopic decompression of the retrocalcaneal bursae and excision of bony spurs. The functional outcome was evaluated by comparing the pre and postoperative American Orthopedic Foot and Ankle Society (AOFAS) scores. The Maryland ankle and foot score was used postoperatively to assess the patient's satisfaction at the one-year followup. Results: The University of Maryland scores of 25 heels were categorized as the nonparametric categories, and it was observed that 16 patients had an excellent outcome, six good, three fair and there were no poor results. The AOFAS scores averaged 57.92 ± 6.224 points preoperatively and 89.08 ± 5.267 points postoperatively (P < 0.001), at an average followup of 16.4 months. The 12 heels having noninsertional tendinosis on ultrasound had low AOFAS scores compared to 13 heels having retrocalcaneal bursitis alone. At one year followup, correlation for preoperative ultrasound assessment of tendoachilles degeneration versus postoperative Maryland score (Spearman correlation) had shown a strong negative correlation. Conclusion: Endoscopic calcaneal resection is highly effective in patients with mild or no degeneration and yields cosmetically better results with fewer complications. Patients with degenerative changes in Achilles tendon had poorer outcomes in terms of subjective satisfaction. PMID:23325968

  9. [Tactical and technical notes for decompression craniotomy--a review].

    PubMed

    Mracek, J; Mracek, Z; Choc, M

    2007-05-01

    The authors present the tactics and technique of the decompression craniotomy (DC). DC is one of the principal neurosurgical procedures in the treatment of intracranial hypertension. Early indication and perfect technical completion of the procedure are the prerequisites for achieving the anticipated decompressive effect. While indications of DC are frequently discussed in the scientific literature, the procedure's tactics and techinque is usually overlooked. The report mentions the DC development and significance from its historical perspective. Decompression craniotomy should be performed as a preventive procedure to prevent secondary brain damage. Four types of craniotomy are used in order to perform decompression: subtemporal, circular, bifrontal and hemispheral. The hemispheral DC best fulfills the essential requirement regarding the brain stem direct compression release. The technical aspect of the hemispheral decompression procedure is described further in the report. The authors discuss some technical aspects, which, provided they are followed, should prevent the surgical method from failure. Incorrect technical performance, especially insufficient extent of the decompression, along with its late indication, is the principal factor discrediting the idea of decompression craniotomy.

  10. Elective decompression of the left ventricle in pediatric patients may reduce the duration of venoarterial extracorporeal membrane oxygenation.

    PubMed

    Hacking, Douglas F; Best, Derek; d'Udekem, Yves; Brizard, Christian P; Konstantinov, Igor E; Millar, Johnny; Butt, Warwick

    2015-04-01

    We aimed to determine the effect of elective left heart decompression at the time of initiation of central venoarterial extracorporeal membrane oxygenation (VA ECMO) on VA ECMO duration and clinical outcomes in children in a single tertiary ECMO referral center with a large pediatric population from a national referral center for pediatric cardiac surgery. We studied 51 episodes of VA ECMO in a historical cohort of 49 pediatric patients treated between the years 1990 and 2013 in the Paediatric Intensive Care Unit (PICU) of the Royal Children's Hospital, Melbourne. The cases had a variety of diagnoses including congenital cardiac abnormalities, sepsis, myocarditis, and cardiomyopathy. Left heart decompression as an elective treatment or an emergency intervention for left heart distension was effectively achieved by a number of methods, including left atrial venting, blade atrial septostomy, and left ventricular cannulation. Elective left heart decompression was associated with a reduction in time on ECMO (128 h) when compared with emergency decompression (236 h) (P = 0.013). Subgroup analysis showed that ECMO duration was greatest in noncardiac patients (elective 138 h, emergency 295 h; P = 0.02) and in patients who died despite both emergency decompression and ECMO (elective 133 h, emergency 354 h; P = 0.002). As the emergency cases had a lower pH, a higher PaCO2 , and a lower oxygenation index and were treated with a higher mean airway pressure, positive end-expiratory pressure, and respiratory rate prior to receiving VA ECMO, we undertook multivariate linear regression modeling to show that only PaCO2 and the timing of left heart decompression were associated with ECMO duration. However, elective left heart decompression was not associated with a reduction in length of PICU stay, duration of mechanical ventilation, or duration of oxygen therapy. Elective left heart decompression was not associated with improved ECMO survival or survival to PICU discharge

  11. Analysis of correlative risk factors for C5 palsy after anterior cervical decompression and fusion

    PubMed Central

    Wang, Haiying; Zhang, Xu; Lv, Bing; Ding, Wenyuan; Shen, Yong; Yang, Dalong; Bai, Zhilong

    2015-01-01

    Background: It has been reported that C5 palsy is a potential complication of both anterior and posterior cervical spine surgery, although several mechanisms of C5 palsy following posterior cervical surgery have been proposed, few reports about correlative risk factors have been elaborated on C5 palsy after anterior cervical decompression and fusion (ACDF). Objective: The purpose of this study was to investigate the correlative risk factors of C5 palsy after anterior cervical decompression and fusion. Methods: This is a retrospective study. A total of 161 patients (108 males and 53 females) who underwent ACDF between 2007 and 2012 were included in this study. C5 palsy is characterized by deltoid and/or biceps brachii weakness. The patients were divided into two groups: one that had experienced C5 palsy (group A) and the other one had not (group B). In both groups, the age, gender, duration of disease, diagnosis, No. of surgical levels, cervical curvature correction, occupying rate of spinal canal at C4/5, diameter of the C4/5 foramen, intervertebral height variation, decompression width and preoperative high-signal intensity zone (HIZ) of spinal cord in T2-weighted MRI at C4/5 were measured and evaluated. The risk factors of C5 palsy were detected with logistic regression analysis. Results: There were no significant differences in age, gender, duration of disease, diagnosis, No. of surgical levels, rate of spinal canal at C4/5 and HIZ of spinal cord in T2-weighted MRI at C4/5. Cervical curvature correction, diameter of the C4/5 foramen, intervertebral height variation and decompression width had significant differences between the two groups (P<0.05). Logistic regression analysis revealed that cervical curvature, diameter of the C4/5 foramen, intervertebral height and decompression width were the pivotal risk factors for the incidence of C5 palsy. Conclusion: For patients with ACDF, greater cervical curvature correction, narrow diameter of the C4/5 foramen

  12. Does the use of arteriovenous loops increase complications rates in posttraumatic microsurgical lower extremity reconstruction?-A matched-pair analysis.

    PubMed

    Momeni, Arash; Lanni, Michael A; Levin, Lawrence S; Kovach, Stephen J

    2017-06-28

    The use of arteriovenous (AV) loops in microsurgical lower extremity reconstruction is a controversial topic. The objective of the present study was to assess the impact of AV loops on complication rates following microsurgical reconstruction of posttraumatic lower extremity defects. Patients who underwent free flap coverage of posttraumatic defects in combination with an AV loop (Group 1) were identified and matched for age, body mass index (BMI), tobacco use, defect location, and flap type with patients who underwent reconstruction without vein grafts (Group 2). Outcomes of interest included complication rate and flap loss rate. Groups 1 and 2 consisted of 10 patients each with a mean age of 51 years (range, 21-79 years) and 47.3 years (range, 22-69 years), respectively (P = 0.596). No differences were noted regarding flap loss (P = 1.0), intraoperative (P = 0.474) or postoperative complication rate [surgical site infection (P = 1.0), bleeding (P = 1.0), delayed wound healing (P = 0.23), dehiscence (P = 0.58), and osseous non-union (P = 1.0)]. Only one flap loss was noted in Group 1. The only differences were increased operative time (P = 0.03) and increased length of stay (P = 0.009) in Group 1. Our results suggest that utilization of vein grafts with creation of AV loops followed by single-stage division and free flap transfer for reconstruction of posttraumatic lower extremity defects achieve reconstructive outcomes similar to those obtained in patients in whom no vein grafts are necessary. © 2017 Wiley Periodicals, Inc.

  13. Decompressive craniectomy for malignant middle cerebral artery infarction: Impact on mortality and functional outcome

    PubMed Central

    Raffiq, Mohammad Azman Mohammed; Haspani, Mohammed Saffari Mohammad; Kandasamy, Regunath; Abdullah, Jafri Malin

    2014-01-01

    Background: Malignant middle cerebral artery (MCA) infarction is a devastating clinical entity affecting about 10% of stroke patients. Decompressive craniectomy has been found to reduce mortality rates and improve outcome in patients. Methods: A retrospective case review study was conducted to compare patients treated with medical therapy and decompressive surgery for malignant MCA infarction in Hospital Kuala Lumpur over a period of 5 years (from January 2007 to December 2012). A total of 125 patients were included in this study; 90 (72%) patients were treated with surgery, while 35 (28%) patients were treated with medical therapy. Outcome was assessed in terms of mortality rate at 30 days, Glasgow Outcome Score (GOS) on discharge, and modified Rankin scale (mRS) at 3 and 6 months. Results: Decompressive craniectomy resulted in a significant reduction in mortality rate at 30 days (P < 0.05) and favorable GOS outcome at discharge (P < 0.05). Good functional outcome based on mRS was seen in 48.9% of patients at 3 months and in 64.4% of patients at 6 months (P < 0.05). Factors associated with good outcome include infarct volume of less than 250 ml, midline shift of less than 10 mm, absence of additional vascular territory involvement, good preoperative Glasgow Coma Scale (GCS) score, and early surgical intervention (within 24 h) (P < 0.05). Age and dominant hemisphere infarction had no significant association with functional outcome. Conclusion: Decompressive craniectomy achieves good functional outcome in, young patients with good preoperative GCS score and favorable radiological findings treated with surgery within 24 h of ictus. PMID:25101197

  14. Gene-environment mismatch in decompression sickness and air embolism.

    PubMed

    Alcock, Joe; Brainard, Andrew H

    2010-08-01

    Decompression sickness causes injury and death in SCUBA divers when air bubbles obstruct the flow of blood. Platelets aggregate in response to gas and promote inflammation. Inflammation in decompression sickness may have its origin in the innate immune system's response to pathogens. Bubbles are often found in tissues during gas-forming infections and in infection-prone states. In these diseases, intravascular gas offers a signal of infection to immune cells. Platelet activation by gas may often accompany a beneficial immune response to pathogens. Pathologic bubble-platelet interaction in decompression illness may be an example of gene-environment mismatch. Published by Elsevier Ltd.

  15. Bubbles Quantified In vivo by Ultrasound Relates to Amount of Gas Detected Post-mortem in Rabbits Decompressed from High Pressure

    PubMed Central

    Bernaldo de Quirós, Yara; Møllerløkken, Andreas; Havnes, Marianne B.; Brubakk, Alf O.; González-Díaz, Oscar; Fernández, Antonio

    2016-01-01

    The pathophysiological mechanism of decompression sickness is not fully understood but there is evidence that it can be caused by intravascular and autochthonous bubbles. Doppler ultrasound at a given circulatory location is used to detect and quantify the presence of intravascular gas bubbles as an indicator of decompression stress. In this manuscript we studied the relationship between presence and quantity of gas bubbles by echosonography of the pulmonary artery of anesthetized, air-breathing New Zealand White rabbits that were compressed and decompressed. Mortality rate, presence, quantity, and distribution of gas bubbles elsewhere in the body was examined postmortem. We found a strong positive relationship between high ultrasound bubble grades in the pulmonary artery, sudden death, and high amount of intra and extra vascular gas bubbles widespread throughout the entire organism. In contrast, animals with lower bubble grades survived for 1 h after decompression until sacrificed, and showed no gas bubbles during dissection. PMID:27493634

  16. Testing of hypotheses about altitude decompression sickness by statistical analyses

    NASA Technical Reports Server (NTRS)

    Van Liew, H. D.; Burkard, M. E.; Conkin, J.; Powell, M. R. (Principal Investigator)

    1996-01-01

    This communication extends a statistical analysis of forced-descent decompression sickness at altitude in exercising subjects (J Appl Physiol 1994; 76:2726-2734) with a data subset having an additional explanatory variable, rate of ascent. The original explanatory variables for risk-function analysis were environmental pressure of the altitude, duration of exposure, and duration of pure-O2 breathing before exposure; the best fit was consistent with the idea that instantaneous risk increases linearly as altitude exposure continues. Use of the new explanatory variable improved the fit of the smaller data subset, as indicated by log likelihood. Also, with ascent rate accounted for, replacement of the term for linear accrual of instantaneous risk by a term for rise and then decay made a highly significant improvement upon the original model (log likelihood increased by 37 log units). The authors conclude that a more representative data set and removal of the variability attributable to ascent rate allowed the rise-and-decay mechanism, which is expected from theory and observations, to become manifest.

  17. Testing of hypotheses about altitude decompression sickness by statistical analyses

    NASA Technical Reports Server (NTRS)

    Van Liew, H. D.; Burkard, M. E.; Conkin, J.; Powell, M. R. (Principal Investigator)

    1996-01-01

    This communication extends a statistical analysis of forced-descent decompression sickness at altitude in exercising subjects (J Appl Physiol 1994; 76:2726-2734) with a data subset having an additional explanatory variable, rate of ascent. The original explanatory variables for risk-function analysis were environmental pressure of the altitude, duration of exposure, and duration of pure-O2 breathing before exposure; the best fit was consistent with the idea that instantaneous risk increases linearly as altitude exposure continues. Use of the new explanatory variable improved the fit of the smaller data subset, as indicated by log likelihood. Also, with ascent rate accounted for, replacement of the term for linear accrual of instantaneous risk by a term for rise and then decay made a highly significant improvement upon the original model (log likelihood increased by 37 log units). The authors conclude that a more representative data set and removal of the variability attributable to ascent rate allowed the rise-and-decay mechanism, which is expected from theory and observations, to become manifest.

  18. Improved chest recoil using an adhesive glove device for active compression-decompression CPR in a pediatric manikin model.

    PubMed

    Udassi, Jai P; Udassi, Sharda; Lamb, Melissa A; Lamb, Kenneth E; Theriaque, Douglas W; Shuster, Jonathan J; Zaritsky, Arno L; Haque, Ikram U

    2009-10-01

    We developed an adhesive glove device (AGD) to perform ACD-CPR in pediatric manikins, hypothesizing that AGD-ACD-CPR provides better chest decompression compared to standard (S)-CPR. Split-plot design randomizing 16 subjects to test four manikin-technique models in a crossover fashion to AGD-ACD-CPR vs. S-CPR. Healthcare providers performed 5min of CPR with 30:2 compression:ventilation ratio in the four manikin models: (1) adolescent; (2) child two-hand; (3) child one-hand; and (4) infant two-thumb. Modified manikins recorded compression pressure (CP), compression depth (CD) and decompression depth (DD). The AGD consisted of a modified oven mitt with an adjustable strap; a Velcro patch was sewn to the palmer aspect. The counter Velcro patch was bonded to the anterior chest wall. For infant CPR, the thumbs of two oven mitts were stitched together with Velcro. Subjects were asked to actively pull up during decompression. Subjects' heart rate (HR), respiratory rate (RR) and recovery time (RT) for HR/RR to return to baseline were recorded. Subjects were blinded to data recordings. Data (mean+/-SEM) were analyzed using a two-tailed paired t-test. Significance was defined qualitatively as P< or =0.05. Mean decompression depth difference was significantly greater with AGD-ACD-CPR compared to S-CPR; 38-75% of subjects achieved chest decompression to or beyond baseline. AGD-ACD-CPR provided 6-12% fewer chest compressions/minute than S-CPR group. There was no significant difference in CD, CP, HR, RR and RT within each group comparing both techniques. A simple, inexpensive glove device for ACD-CPR improved chest decompression with emphasis on active pull in manikins without excessive rescuer fatigue. The clinical implication of fewer compressions/minute in the AGD group needs to be evaluated.

  19. Long-term rates of chemical weathering and physical erosion in extreme climates, measured by cosmogenic nuclides and geochemical mass balance

    NASA Astrophysics Data System (ADS)

    Riebe, C. S.; Kirchner, J. W.; Finkel, R. C.

    2001-12-01

    Chemical weathering and physical erosion jointly regulate soil development and deliver sediment and solutes to riverine habitats. Chemical weathering also generates nutrients and helps regulate global climate over million year timescales. Thus it is important to quantify long-term rates of weathering and erosion in different environments. New cosmogenic nuclide and geochemical mass balance techniques can be widely applied to measure long-term rates of chemical weathering and physical erosion. In previous work, we used those techniques to show that both physical erosion and chemical weathering rates are insensitive to differences in climate across a set of granitic Sierra Nevada study sites that span 20-145 cm/yr in average precipitation and 4-15 ° C in mean annual temperature. Our measurements also showed that long-term rates of chemical weathering and physical erosion are tightly coupled, possibly because chemical weathering rates are regulated by rates of fresh mineral supply by physical erosion of rock. Here we present long-term rates of chemical weathering and physical erosion from new sites with more extreme climates, including both temperate and tropical rainforests. Overall, mean annual temperature spans 4-22 ° C and average precipitation span 20-420 cm/yr across our sites. Our new weathering and erosion data should reveal whether climatic effects on rates of weathering and erosion are more pronounced over a greatly extended range of climates.

  20. Extremely high fracture rate of a modular acetabular component with a sandwich polyethylene ceramic insertion for THA: a preliminary report.

    PubMed

    Kircher, Jörn; Bader, Rainer; Schroeder, Bettina; Mittelmeier, Wolfram

    2009-09-01

    Improvements of ceramic components and design changes have reduced failure rates over the past 30 years in total hip arthroplasty. We present a series of n = 11 cases with ceramic failure out of n = 113 implantations, from which n = 66 were ceramic-on-ceramic (n = 50 with ceramic insert with sandwich in polyethylene and n = 16 with directly fixed ceramic inlay) and n = 47 ceramic on polyethylene bearings, between 1999 and 2001 after introduction of a new implantation system to the market. The overall fracture rate of ceramic for the whole series (n = 113) was 9.7%. For the combination ceramic head with UHMW-PE (n = 47) the fracture rate was 2.1%. For the combination ceramic with ceramic (n = 66) the fracture rate was 15.2%. For the combination ceramic with ceramic sandwich in PE (n = 50) the failure rate was 18%. Only three patients experienced a trauma. Demography of patients (age, gender, body weight and BMI) was not statistically different between patients with failed ceramics and the rest of the patients making patient-specific risk factors unlikely to be an explanation for the failures. Retrospective X-ray analysis of the cup positioning did not show significant difference between failed and non-failed implants in terms of mean cup inclination and version making also operation-specific factors unlikely to be the only reason of this high failure rate. Therefore, manufacturer-specific factors such as design features may have contributed to this high failure rate. Further analysis of the whole series with biomechanical testing of the retrieved material needs to be performed.

  1. An anomaly against a current paradigm--extremely low rates of individual fecundity variability of the Gordian worm (Nematomorpha: Gordiida).

    PubMed

    Hanelt, B

    2009-02-01

    Extreme variation in reproductive success (VRS) has been reported as a common feature of populations. Few individuals producing most of the offspring for the next generation has potential consequences for the population dynamics, genetics, and evolution of a group of organisms. High VRS has been described as a normal feature of helminth populations, although studies have focused largely on parasites of vertebrate hosts. Paragordius varius, a parasite of crickets, was used as a model system to study VRS. In this life cycle, worms absorb and store resources for reproduction from their hosts before being released into water. Egg output varied significantly with worm length, indicating that female length is an excellent predictor of fecundity. Analyses using the Lorenz curve and Gini coefficient suggest that there were no marked fecundity differences. This result was supported by data collected from a natural gordiid population, Gordius difficilis, suggesting that within gordiid populations the offspring of the next generation are contributed nearly equally by females. In addition, male body length appeared to be limited by intensity, whereas females showed no length limitation by crowding. These results contrast previous studies of parasites.

  2. Magma degassing triggered by static decompression at Kīlauea Volcano, Hawai‘i

    USGS Publications Warehouse

    Poland, Michael P.; Jeff, Sutton A.; Gerlach, Terrence M.

    2009-01-01

    During mid-June 2007, the summit of Kīlauea Volcano, Hawai‘i, deflated rapidly as magma drained from the subsurface to feed an east rift zone intrusion and eruption. Coincident with the deflation, summit SO2 emission rates rose by a factor of four before decaying to background levels over several weeks. We propose that SO2 release was triggered by static decompression caused by magma withdrawal from Kīlauea's shallow summit reservoir. Models of the deflation suggest a pressure drop of 0.5–3 MPa, which is sufficient to trigger exsolution of the observed excess SO2 from a relatively small volume of magma at the modeled source depth beneath Kīlauea's summit. Static decompression may also explain other episodes of deflation accompanied by heightened gas emission, including the precursory phases of Kīlauea's 2008 summit eruption. Hazards associated with unexpected volcanic gas emission argue for increased awareness of magma reservoir pressure fluctuations.

  3. Extremely high-rate, uniform dissolution of alloy C-22 in anhydrous organic solutions at room temperature

    SciTech Connect

    Schindelholz, Eric J.; Christie, Michael A.; Allwein, Shawn P.; Kelly, Robert G.

    2016-06-21

    During routine pharmaceutical development and scale-up work, severe corrosion of a Hastelloy Alloy C-22 filter dryer was observed after single, short (several hours) contact with the product slurry at room temperature. Initial investigations showed that the presence of both 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HCl was sufficient in an acetonitrile solution to cause rapid corrosion of C-22. More detailed mass loss studies showed initial corrosion rates exceeding25 mm/year that then decreased over several hours to steady state rates of 3-5 mm/year. The corrosion was highly uniform. Electrochemical measurements demonstrated that although C-22 is spontaneously passive in acetonitrile solution, the presence of HCl leads to the development of a transpassive region. Furthermore, DDQ is a sufficiently strong oxidizer, particularly in acidic solutions, to polarize the C-22 well into the transpassive region, leading to the observed high corrosion rates.

  4. Extremely high-rate, uniform dissolution of alloy C-22 in anhydrous organic solutions at room temperature

    SciTech Connect

    Schindelholz, Eric J.; Christie, Michael A.; Allwein, Shawn P.; Kelly, Robert G.

    2016-06-21

    During routine pharmaceutical development and scale-up work, severe corrosion of a Hastelloy Alloy C-22 filter dryer was observed after single, short (several hours) contact with the product slurry at room temperature. Initial investigations showed that the presence of both 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HCl was sufficient in an acetonitrile solution to cause rapid corrosion of C-22. More detailed mass loss studies showed initial corrosion rates exceeding25 mm/year that then decreased over several hours to steady state rates of 3-5 mm/year. The corrosion was highly uniform. Electrochemical measurements demonstrated that although C-22 is spontaneously passive in acetonitrile solution, the presence of HCl leads to the development of a transpassive region. Furthermore, DDQ is a sufficiently strong oxidizer, particularly in acidic solutions, to polarize the C-22 well into the transpassive region, leading to the observed high corrosion rates.

  5. [A comparation of efficacy between unilateral laminectomy approach bilateral decompression and traditional total laminectomy decompression in the treatment of lumbar spinal stenosis].

    PubMed

    Hu, W; Zhao, J; Gong, C; Zou, M; Yuan, J H; Liu, X Y

    2016-06-07

    To compare the efficacy between unilateral laminectomy approach bilateral decompression and traditional total laminectomy decompression in the treatment of graft bone fusion and internal fixation for degenerative lumbar spinal stenosis with the unilateral symptoms. From January 2013 to December 2014, a total of 40 patients with unilateral symptoms of lumbar spinal stenosis were treated in Department of Spinal Surgery Bozhou People's Hospital of Anhui Province. Twenty patients(group A ) were treated by severe symptoms unilateral facetectomy and resection of superior articular and laminectomy and lateral recess decompression, interbody fusion, pedicle screw fixation.Twenty patients(group B ) were treated by total laminectomy interbody fusion and pedicle screw fixation.The time of operation, blood loss of the two groups were recorded.At the same time the visual analog scale (VAS), Oswestry disability index(ODI), Japanese Orthopaedic Association Scores(JOA) before and after operation (3, 6 , 12months) were recorded retrospectively. The effect of surgery were evaluated and compared. The VAS, JOA, and ODI of group A preoperation is respectively have no significant differences with the group B (P>0.05). The operation time, blood loss in operation of group A was respectively(133.2±25.3) min, (415.0±42.1) ml, significant differences with the group B[(491.0±46.3)ml; (156.2±28.5) min, P<0.05)]. The VAS, JOA, ODI of group A had no significant differences with the group B (P>0.05) at 3, 6 months after operation.The VAS, JOA, ODI of group A was respectively (3.0±0.6), (25.3±5.1), (16.5±1.5)scores, had significant differences with the group B and preoperation (P<0.05) at 12 months after operation. The radiographic data showed that the interbody fusion rate of group A was 100%, and group B was 95%, had significant differences by statistical analysis (P<0.05) at 12 months afer operation. The improved unilateral laminectomy approach and bilateral decompression have less

  6. Lower Extremity Amputation and Mortality Rates in the Reconstructed Diabetic Charcot Foot and Ankle With External Fixation: Data Analysis of 116 Patients.

    PubMed

    Ramanujam, Crystal L; Han, David; Zgonis, Thomas

    2016-04-01

    The aim of this study was to determine the lower extremity amputation and mortality rates of a group of patients who underwent reconstructive surgery using circular external fixation for treatment of diabetic Charcot neuroarthropathy (CN) of the foot and/or ankle. Existing studies regarding lower extremity amputation or mortality rates for diabetic CN of the foot and/or ankle have been performed on mostly conservatively treated patients. The objective of the statistical analysis in this studied population was to understand the difference in overall amputation and mortality rates between the 2 main groups: one with foot and/or ankle ulceration (group 1), and the other without ulceration or osteomyelitis (group 2, control group). Within group 1, 2 subgroups were established: one with osteomyelitis (group 1A) and the other without osteomyelitis (group 1B). Initially, a retrospective analysis of 150 consecutive surgically reconstructed diabetic foot and ankle cases using circular external fixation from January 2005 through December 2012 was conducted. Those which were not supported with the diagnosis of diabetic CN were excluded and the 2 other charts without proper follow-up duration (6 months) for analysis were removed, resulting in the final sample size of N = 116. There were a total of n = 7 (6.0%) below the knee amputations (group 1A = 1, group 1B = 4, and group 2 = 2) with a total of n = 5 mortalities (4.3%) (group 1A = 2, group 1B = 2, and group 2 = 1). The total amount of time for a lower extremity amputation event (n = 7) since the time of surgical reconstruction was 729.43 ± 519.73 days (range 230-1777 days) while for a mortality event (n = 5), it was 1302.00 ± 765.48 days (range 633-2499 days). Prognostic, Level III: Retrospective study. © 2015 The Author(s).

  7. Effect of inert gas switching at depth on decompression outcome in rats.

    PubMed

    Lillo, R S; MacCallum, M E

    1989-10-01

    The present investigation was performed to determine whether inert gas sequencing at depth would affect decompression outcome in rats via the phenomenon of counterdiffusion. Unanesthetized rats (Rattus norvegicus) were subjected to simulated dives in either air, 79% He-21% O2, or 79% Ar-21% O2; depths ranged from 125 to 175 feet of seawater (4.8-6.3 atmospheres absolute). After 1 h at depth, the dive chamber was vented (with depth held constant) over a 5-min period with the same gas as in the chamber (controls) or one of the other two inert gas-O2 mixtures. After the gas switch, a 5- to 35-min period was allowed for gas exchange between the animals and chamber atmosphere before rapid decompression to the surface. Substantial changes in the risk of decompression sickness (DCS) were observed after the gas switch because of differences in potencies (He less than N2 less than Ar) for causing DCS and gas exchange rates (He greater than Ar greater than N2) among the three gases. Based on the predicted gas exchange rates, transient increases or decreases in total inert gas pressure would be expected to occur during these experimental conditions. Because of differences in gas potencies, DCS risk may not directly follow the changes in total inert gas pressure. In fact, a decline in predicted DCS risk may occur even as total inert gas pressure in increasing.

  8. Experimental results on decompression crystallization in an Aleutian basaltic-andesite

    NASA Astrophysics Data System (ADS)

    Larsen, J. F.; Gardner, J. E.

    2005-12-01

    In 1991-92, Westdahl volcano in the Aleutians erupted basaltic andesitic magma, producing lava fountaining and ash clouds to 2 km asl, resulting in a lava flow that extended about 7 km from vent. In order to understand the magmatic ascent rates during that relatively non-explosive eruption, this study compares plagioclase and orthopyroxene microlite textures in the basaltic andesite to crystallization kinetics of plagioclase and pyroxene in laboratory experiments. The experiments used melt-rich basaltic andesite that was hydrated at 150 MPa, 1000° C, and an oxygen fugacity of NNO. Before decompression, the starting material was mainly water-saturated melt that contained a few percent of Fe-Ti oxides and pargasite. Pieces of the starting material were then decompressed rapidly to 25 MPa, and held for various times. Preliminary results show that when held at low pressure for less than 1 hour no crystallization occurred, except for some growth around existing pargasite and oxides. In runs held for about an hour both enstatite and plagioclase nucleate and grow, and are skeletal. In runs held from 4 to 24 hours, plagioclase growth dominates, as enstatite remains a minor phase. The single-step decompressions will be compared with runs using multiple steps to examine how the kinetics change. We can then compare the results with observed crystallization textures in the Westdahl lava and tephra to infer the path and rate of magma ascent during that eruption.

  9. Demographic effects of extreme weather events: snow storms, breeding success, and population growth rate in a long-lived Antarctic seabird

    PubMed Central

    Descamps, Sébastien; Tarroux, Arnaud; Varpe, Øystein; Yoccoz, Nigel G; Tveraa, Torkild; Lorentsen, Svein-Håkon

    2015-01-01

    Weather extremes are one important element of ongoing climate change, but their impacts are poorly understood because they are, by definition, rare events. If the frequency and severity of extreme weather events increase, there is an urgent need to understand and predict the ecological consequences of such events. In this study, we aimed to quantify the effects of snow storms on nest survival in Antarctic petrels and assess whether snow storms are an important driver of annual breeding success and population growth rate. We used detailed data on daily individual nest survival in a year with frequent and heavy snow storms, and long term data on petrel productivity (i.e., number of chicks produced) at the colony level. Our results indicated that snow storms are an important determinant of nest survival and overall productivity. Snow storm events explained 30% of the daily nest survival within the 2011/2012 season and nearly 30% of the interannual variation in colony productivity in period 1985–2014. Snow storms are a key driver of Antarctic petrel breeding success, and potentially population dynamics. We also found state-dependent effects of snow storms and chicks in poor condition were more likely to die during a snow storm than chicks in good condition. This stresses the importance of considering interactions between individual heterogeneity and extreme weather events to understand both individual and population responses to climate change. PMID:25691959

  10. Demographic effects of extreme weather events: snow storms, breeding success, and population growth rate in a long-lived Antarctic seabird.

    PubMed

    Descamps, Sébastien; Tarroux, Arnaud; Varpe, Øystein; Yoccoz, Nigel G; Tveraa, Torkild; Lorentsen, Svein-Håkon

    2015-01-01

    Weather extremes are one important element of ongoing climate change, but their impacts are poorly understood because they are, by definition, rare events. If the frequency and severity of extreme weather events increase, there is an urgent need to understand and predict the ecological consequences of such events. In this study, we aimed to quantify the effects of snow storms on nest survival in Antarctic petrels and assess whether snow storms are an important driver of annual breeding success and population growth rate. We used detailed data on daily individual nest survival in a year with frequent and heavy snow storms, and long term data on petrel productivity (i.e., number of chicks produced) at the colony level. Our results indicated that snow storms are an important determinant of nest survival and overall productivity. Snow storm events explained 30% of the daily nest survival within the 2011/2012 season and nearly 30% of the interannual variation in colony productivity in period 1985-2014. Snow storms are a key driver of Antarctic petrel breeding success, and potentially population dynamics. We also found state-dependent effects of snow storms and chicks in poor condition were more likely to die during a snow storm than chicks in good condition. This stresses the importance of considering interactions between individual heterogeneity and extreme weather events to understand both individual and population responses to climate change.

  11. Could some aviation deep vein thrombosis be a form of decompression sickness?

    PubMed

    Buzzacott, Peter; Mollerlokken, Andreas

    2016-10-01

    Aviation deep vein thrombosis is a challenge poorly understood in modern aviation. The aim of the present project was to determine if cabin decompression might favor formation of vascular bubbles in commercial air travelers. Thirty commercial flights were taken. Cabin pressure was noted at take-off and at every minute following, until the pressure stabilized. These time-pressure profiles were imported into the statistics program R and analyzed using the package SCUBA. Greatest pressure differentials between tissues and cabin pressures were estimated for 20, 40, 60, 80 and 120 min half-time compartments. Time to decompress ranged from 11 to 47 min. The greatest drop in cabin pressure was from 1022 to 776 mBar, equivalent to a saturated diver ascending from 2.46 msw depth. Mean pressure drop in flights >2 h duration was 193 mBar, while mean pressure drop in flights <2 h was 165 mBar. The greatest drop in pressure over 1 min was 28 mBar. Over 30 commercial flights it was found that the drop in cabin pressure was commensurate with that found to cause bubbles in man. Both the US Navy and the Royal Navy mandate far slower decompression from states of saturation, being 1.7 and 1.9 mBar/min respectively. The median overall rate of decompression found in this study was 8.5 mBar/min, five times the rate prescribed for USN saturation divers. The tissues associated with hypobaric bubble formation are likely slower than those associated with bounce diving, with 60 min a potentially useful index.

  12. Biliary metal stents are superior to plastic stents for preoperative biliary decompression in pancreatic cancer.

    PubMed

    Decker, Christopher; Christein, John D; Phadnis, Milind A; Wilcox, C Mel; Varadarajulu, Shyam

    2011-07-01

    It is unclear whether plastic or metal stents are more suitable for preoperative biliary decompression in pancreatic cancer. The objective of this study was to compare the rate of endoscopic reinterventions in patients with pancreatic cancer undergoing plastic or self-expandable metal stent (SEMS) placements for preoperative biliary decompression. This was a retrospective study of all patients with obstructive jaundice secondary to pancreatic head cancer who underwent their index endoscopic retrograde cholangiopancreatography (ERCP) and all follow-up biliary stent placements at our center before undergoing pancreaticoduodenectomy. Plastic or SEMS were placed at ERCP for biliary decompression. The main outcome measure was to compare the rate of endoscopic reinterventions between the plastic and SEMS cohorts. 29 patients who underwent pancreaticoduodenectomy had preoperative biliary stent placement (18 plastic, 11 SEMS) at our center. Whereas none of the 11 patients who underwent SEMS placement had stent dysfunction, 7 of 18 (39%) patients with plastic stents required endoscopic reintervention before surgery (P=0.02). Reinterventions were due to cholangitis (n=1) or persistent elevation in serum bilirubin levels (n=6). Two patients with SEMS underwent EUS-guided fine-needle aspiration after ERCP, which yielded a positive diagnosis of cancer in all cases; SEMS did not impair visualization of the tumor mass at EUS. Pancreaticoduodenectomy was undertaken successfully in all 29 patients and the presence of a SEMS did not interfere with biliary anastomosis. On univariate logistic regression, only SEMS placement was associated with less need for endoscopic reintervention (P=0.02). SEMS are superior to plastic stents for preoperative biliary decompression in pancreatic cancer.

  13. Treatment of Peripheral Neuropathy in Leprosy: The Case for Nerve Decompression

    PubMed Central

    Wan, Eric L.; Rivadeneira, Andres F.; Jouvin, Renato Martinez

    2016-01-01

    Summary: Plastic surgery has a tradition of caring for patients with facial deformity and hand deformity related to leprosy. The approach, however, to the progressive deformity and disability related to chronic nerve compression is underappreciated in the world today. A cohort of patients with leprous neuropathy from an indigenous area of leprosy in Ecuador was evaluated for the presence of chronic peripheral nerve compression, and 12 patients were chosen for simultaneous upper and lower extremity, unilateral, nerve decompression at multiple levels along the course of each nerve. The results at 1 year of follow-up show that 6 patients improved into the excellent category and 4 patients improved into the good category for improved function. Based on the early results in this small cohort of patients with leprous neuropathy, an approach to peripheral nerve decompression, encompassing the concept of multiple crush at multiple levels of each nerve, seems to offer optimism to improve upper and lower extremity limb function. Long-term studies with quality-of-life outcomes would be welcome. PMID:27257567

  14. Circumferential decompression of the foramen magnum for the treatment of syringomyelia associated with basilar invagination.

    PubMed

    Collignon, Frederic P; Cohen-Gadol, Aaron A; Krauss, William E

    2004-07-01

    Posterior fossa decompression utilizing suboccipital craniectomy and duraplasty remains the standard surgical treatment for Chiari-associated syringomyelia. In the presence of basilar invagination, anterior decompression, typically transoral odontoidectomy, or posterior decompression may be performed. We report two cases in which anterior and posterior (circumferential) decompression of the foramen magnum was used to treat cervical syringomyelia successfully. These cases demonstrate that circumferential decompression of the foramen magnum may be necessary in some cases of cervical syringomyelia associated with basilar invagination and Chiari malformation.

  15. The probability and severity of decompression sickness.

    PubMed

    Howle, Laurens E; Weber, Paul W; Hada, Ethan A; Vann, Richard D; Denoble, Petar J

    2017-01-01

    Decompression sickness (DCS), which is caused by inert gas bubbles in tissues, is an injury of concern for scuba divers, compressed air workers, astronauts, and aviators. Case reports for 3322 air and N2-O2 dives, resulting in 190 DCS events, were retrospectively analyzed and the outcomes were scored as (1) serious neurological, (2) cardiopulmonary, (3) mild neurological, (4) pain, (5) lymphatic or skin, and (6) constitutional or nonspecific manifestations. Following standard U.S. Navy medical definitions, the data were grouped into mild-Type I (manifestations 4-6)-and serious-Type II (manifestations 1-3). Additionally, we considered an alternative grouping of mild-Type A (manifestations 3-6)-and serious-Type B (manifestations 1 and 2). The current U.S. Navy guidance allows for a 2% probability of mild DCS and a 0.1% probability of serious DCS. We developed a hierarchical trinomial (3-state) probabilistic DCS model that simultaneously predicts the probability of mild and serious DCS given a dive exposure. Both the Type I/II and Type A/B discriminations of mild and serious DCS resulted in a highly significant (p < 0.01) improvement in trinomial model fit over the binomial (2-state) model. With the Type I/II definition, we found that the predicted probability of 'mild' DCS resulted in a longer allowable bottom time for the same 2% limit. However, for the 0.1% serious DCS limit, we found a vastly decreased allowable bottom dive time for all dive depths. If the Type A/B scoring was assigned to outcome severity, the no decompression limits (NDL) for air dives were still controlled by the acceptable serious DCS risk limit rather than the acceptable mild DCS risk limit. However, in this case, longer NDL limits were allowed than with the Type I/II scoring. The trinomial model mild and serious probabilities agree reasonably well with the current air NDL only with the Type A/B scoring and when 0.2% risk of serious DCS is allowed.

  16. The probability and severity of decompression sickness

    PubMed Central

    Hada, Ethan A.; Vann, Richard D.; Denoble, Petar J.

    2017-01-01

    Decompression sickness (DCS), which is caused by inert gas bubbles in tissues, is an injury of concern for scuba divers, compressed air workers, astronauts, and aviators. Case reports for 3322 air and N2-O2 dives, resulting in 190 DCS events, were retrospectively analyzed and the outcomes were scored as (1) serious neurological, (2) cardiopulmonary, (3) mild neurological, (4) pain, (5) lymphatic or skin, and (6) constitutional or nonspecific manifestations. Following standard U.S. Navy medical definitions, the data were grouped into mild—Type I (manifestations 4–6)–and serious–Type II (manifestations 1–3). Additionally, we considered an alternative grouping of mild–Type A (manifestations 3–6)–and serious–Type B (manifestations 1 and 2). The current U.S. Navy guidance allows for a 2% probability of mild DCS and a 0.1% probability of serious DCS. We developed a hierarchical trinomial (3-state) probabilistic DCS model that simultaneously predicts the probability of mild and serious DCS given a dive exposure. Both the Type I/II and Type A/B discriminations of mild and serious DCS resulted in a highly significant (p << 0.01) improvement in trinomial model fit over the binomial (2-state) model. With the Type I/II definition, we found that the predicted probability of ‘mild’ DCS resulted in a longer allowable bottom time for the same 2% limit. However, for the 0.1% serious DCS limit, we found a vastly decreased allowable bottom dive time for all dive depths. If the Type A/B scoring was assigned to outcome severity, the no decompression limits (NDL) for air dives were still controlled by the acceptable serious DCS risk limit rather than the acceptable mild DCS risk limit. However, in this case, longer NDL limits were allowed than with the Type I/II scoring. The trinomial model mild and serious probabilities agree reasonably well with the current air NDL only with the Type A/B scoring and when 0.2% risk of serious DCS is allowed. PMID:28296928

  17. Investigation of Hematologic and Pathologic Response to Decompression.

    DTIC Science & Technology

    1978-05-10

    advanced case of osteonecrosjs did not manifest itself radiographically. In addition to -extensive necrosis of the cortical bone with peniosteal new...weeks of the ini tial decompression (6 , 7) . His tologic study of these cases of osteonecrosis , as well as evid ence presented by other investi gators...itching of the skin was not considered a frank sign of decompression sickness. United States Navy Standard Air , Royal Navy or Exceptional Ex- posure Air

  18. Sub-diffraction Imaging via Surface Plasmon Decompression

    DTIC Science & Technology

    2014-06-08

    of the local wavelength of a surface plasmon polariton supported by two adjoining curved metal surfaces. The views, opinions and/or findings...adiabatic decompression of the local wavelength of a surface plasmon polariton supported by two adjoining curved metal surfaces. Conference Name...diffraction imaging based on a process of adiabatic decompression of the local wavelength of a surface plasmon polariton supported by two adjoining curved

  19. Operation Everest II. Altitude Decompression Sickness during Repeated Altitude Exposure,

    DTIC Science & Technology

    1986-05-01

    James Alexander, Maureen Andrew, James Anholm, Louis Banderet, Dick Burse, Jonathan Carter, Howard Green, Geoff r Coates , Howard Donner, Ulrich Duncan...sickness: advances and interpretations. Aerospace Med. 1971, 42:255-267. 4. Behnke, A.R. Decompression sickness incident to deep sea diving and high...Med. pp. 1974, 297-300. 10. Fryer , D.I. Decompression sickness at 18,500 feet. A case history with comment. Aerospace Med. 1964, 35:479-481. 11. Fryer

  20. Cases from the aerospace medicine residents' teaching file. Decompression sickness.

    PubMed

    Taylor, G N

    2000-12-01

    Decompression sickness is an uncommon but serious risk associated with flying and SCUBA diving with potential for significant morbidity and mortality. It can occur in both novice and experienced individuals. This case illustrates an atypical presentation of decompression sickness in an experienced amateur SCUBA diver. Clinical suspicion must be high, since the presenting symptoms can be nonspecific as in this case. Early recognition and treatment are important for maximum recovery.

  1. Headache and Decompression Sickness: Type I or Type II?

    DTIC Science & Technology

    2001-06-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADPO 11060 TITLE: Headache and Decompression Sickness: Type I or Type II...The following component part numbers comprise the compilation report: ADPO11059 thru ADP011100 UNCLASSIFIED 2-1 Headache and Decompression Sickness...while Type II necessitates recompression with 100% oxygen (7). Headache associated with DCS is not new. Ryles and Pilmanis reported an eleven-year

  2. Patterns and Variations in Microvascular Decompression for Trigeminal Neuralgia

    PubMed Central

    TODA, Hiroki; GOTO, Masanori; IWASAKI, Koichi

    2015-01-01

    Microvascular decompression (MVD) is a highly effective surgical treatment for trigeminal neuralgia (TN). Although there is little prospective clinical evidence, accumulated observational studies have demonstrated the benefits of MVD for refractory TN. In the current surgical practice of MVD for TN, there have been recognized patterns and variations in surgical anatomy and various decompression techniques. Here we provide a stepwise description of surgical procedures and relevant anatomical characteristics, as well as procedural options. PMID:25925756

  3. High Cycling Stability and Extreme Rate Performance in Nanoscaled LiMn2O4 Thin Films.

    PubMed

    Put, Brecht; Vereecken, Philippe M; Labyedh, Nouha; Sepulveda, Alfonso; Huyghebaert, Cedric; Radu, Iuliana P; Stesmans, Andre

    2015-10-14

    Ultrathin LiMn2O4 electrode layers with average crystal size of ∼15 nm were fabricated by means of radio frequency sputtering. Cycling behavior and rate performance was evaluated by galvanostatic charge and discharge measurements. The thinnest films show the highest volumetric capacity and best cycling stability, retaining the initial capacity over 70 (dis)charging cycles when manganese dissolution is prevented. The increased stability for film thicknesses below 50 nm allows cycling in both the 4 and 3 V potential regions, resulting in a high volumetric capacity of 1.2 Ah/cm3. It is shown that the thinnest films can be charged to 75% of their full capacity within 18 s (200 C), the best rate performance reported for LiMn2O4. This is explained by the short diffusion lengths inherent to thin films and the absence of phase transformation.

  4. Extremely high-rate, uniform dissolution of alloy C-22 in anhydrous organic solutions at room temperature

    DOE PAGES

    Schindelholz, Eric J.; Christie, Michael A.; Allwein, Shawn P.; ...

    2016-06-21

    During routine pharmaceutical development and scale-up work, severe corrosion of a Hastelloy Alloy C-22 filter dryer was observed after single, short (several hours) contact with the product slurry at room temperature. Initial investigations showed that the presence of both 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HCl was sufficient in an acetonitrile solution to cause rapid corrosion of C-22. More detailed mass loss studies showed initial corrosion rates exceeding25 mm/year that then decreased over several hours to steady state rates of 3-5 mm/year. The corrosion was highly uniform. Electrochemical measurements demonstrated that although C-22 is spontaneously passive in acetonitrile solution, the presence of HClmore » leads to the development of a transpassive region. Furthermore, DDQ is a sufficiently strong oxidizer, particularly in acidic solutions, to polarize the C-22 well into the transpassive region, leading to the observed high corrosion rates.« less

  5. Extreme difference in rate of mitochondrial and nuclear DNA evolution in a large ectotherm, Galápagos tortoises.

    PubMed

    Caccone, Adalgisa; Gentile, Gabriele; Burns, Catherine E; Sezzi, Erminia; Bergman, Windsong; Ruelle, Morgan; Saltonstall, Kristin; Powell, Jeffrey R

    2004-05-01

    We sequenced approximately 4.5 kb of mtDNA from 161 individuals representing 11 named taxa of giant Galápagos tortoises (Geochelone nigra) and about 4 kb of non-coding nuclear DNA from fewer individuals of these same 11 taxa. In comparing mtDNA and nucDNA divergences, only silent substitutions (introns, ITS, mtDNA control region, and synonymous substitutions in coding sequences) were considered. mtDNA divergence was about 30 times greater than that for nucDNA. This rate discrepancy for mtDNA and nucDNA is the greatest yet documented and is particularly surprising for large ectothermic animals that are thought to have relatively low rates of mtDNA evolution. This observation may be due to the somewhat unusual reproductive biology and biogeographic history of these organisms. The implication is that the ratio of effective population size of nucDNA/mtDNA is much greater than the usually assumed four. The nearly neutral theory of molecular evolution predicts this would lead to a greater difference between rates of evolution.

  6. Mesoporous CNT@TiO2-C Nanocable with Extremely Durable High Rate Capability for Lithium-Ion Battery Anodes

    PubMed Central

    Wang, Bin; Xin, Huolin; Li, Xiaodong; Cheng, Jianli; Yang, Guangcheng; Nie, Fude

    2014-01-01

    A well-designed nanostructure CNT@TiO2-C with fine anatase TiO2 particle (< 8 nm), good electronic conducting network (inner CNT core and outer carbon layer), and mesoporous structure was prepared by a simple and green one-pot hydrothermal reaction. The utilization of glucose in the hydrothermal process not only solves the interfacial incompatibility between CNTs and titanate sol and controls the nucleation and growth of TiO2 particles, but also introduces a uniform, glucose-derived, carbon-layer on the TiO2 particles. The nanosized TiO2 particle, high conducting network, and interconnected nanopores of the CNT@TiO2-C nanocable greatly improve its electrochemical performances, especially rate capability. The CNT@TiO2-C nanocables show remarkable rate capability with reversible charge capacity of 297, 240, 210,178 and 127 mAh g−1 at 1C, 5C, 10C, 20C and 50C, respectively, as well as excellent high rate cycling stability with capacity retention of 87% after 2000 cycles at 50C. PMID:24429419

  7. A Novel Martensitic Creep-Resistant Steel Strengthened by MX Carbonitrides with Extremely Low Coarsening Rates: Design and Characterization

    NASA Astrophysics Data System (ADS)

    Lu, Qi; Ma, Wenjie; Yan, Wei; Yang, Ke; Toda, Yoshiaki; van der Zwaag, Sybrand; Xu, Wei

    2016-09-01

    A general computational alloy design approach, based on thermodynamics and thermokinetics and coupled with a genetic algorithm optimization routine, was applied to the design of novel creep martensitic resistant steels. The optimal alloy suggested by the model has a high density of barely coarsening MX carbonitride precipitates. The model yielded precise values for the concentrations of the 10 alloying elements considered. The model alloy was produced on a 10 kg lab scale. Samples of the new alloy of one of the best commercial martensitic steels on the market P92 were subjected to a high aging temperature of 923 K (650 °C) for times up to 1000 hours. The microstructure of the new alloy in the as-produced state as well as after 1000 hours exposure has all the intended features as predicted by the model. The coarsening rate of the MX rate carbonitrides was substantially lower than that of the precipitates in the P92 steel. The very low coarsening rate explains the superior hardness at very long exposure times.

  8. The Impact of Mass Segregation and Star Formation on the Rates of Gravitational-wave Sources from Extreme Mass Ratio Inspirals

    NASA Astrophysics Data System (ADS)

    Aharon, Danor; Perets, Hagai B.

    2016-10-01

    Compact stellar objects inspiraling into massive black holes (MBHs) in galactic nuclei are some of the most promising gravitational-wave (GWs) sources for next-generation GW detectors. The rates of such extreme mass ratio inspirals (EMRIs) depend on the dynamics and distribution of compact objects (COs) around the MBH. Here, we study the impact of mass-segregation processes on EMRI rates. In particular, we provide the expected mass function (MF) of EMRIs, given an initial MF of stellar black holes (SBHs), and relate it to the mass-dependent detection rate of EMRIs. We then consider the role of star formation (SF) on the distribution of COs and its implication on EMRI rates. We find that the existence of a wide spectrum of SBH masses leads to the overall increase of EMRI rates and to high rates of the EMRIs from the most massive SBHs. However, it also leads to a relative quenching of EMRI rates from lower-mass SBHs, and together produces a steep dependence of the EMRI MF on the highest-mass SBHs. SF history plays a relatively small role in determining the EMRI rates of SBHs, since most of them migrate close to the MBH through mass segregation rather than forming in situ. However, the EMRI rate of neutron stars (NSs) can be significantly increased when they form in situ close to the MBH, as they can inspiral before relaxation processes significantly segregate them outward. A reverse but weaker effect of decreasing the EMRI rates from NSs and white dwarfs occurs when SF proceeds far from the MBH.

  9. Microendoscopic posterior decompression for the treatment of thoracic myelopathy caused by ossification of the ligamentum flavum: a technical report.

    PubMed

    Baba, Satoshi; Oshima, Yasushi; Iwahori, Tomoyuki; Takano, Yuichi; Inanami, Hirohiko; Koga, Hisashi

    2016-06-01

    Ossification of the ligamentum flavum (OLF) is a common cause of progressive thoracic myelopathy in East Asia. Good surgical results are expected for patients who already show myelopathy. Surgical decompression using a posterior approach is commonly used to treat OLF. This study investigated the use of microendoscopic posterior decompression for the treatment of thoracic OLF. Microendoscopic posterior decompression was performed on 9 patients with myelopathy. Patients had a mean age of 59.8 years and single-level involvement, mostly at the T10-11 and T11-12 vertebrae. Computed tomography and magnetic resonance imaging were used to classify the OLF. A tubular retractor and endoscopic system were used for microendoscopic posterior decompression. Midline and unilateral paramedian approaches were performed in 2 and 7 patients, respectively. Intraoperative motor evoked potentials (MEPs) of 7 patients were monitored. Pre- and postoperative neurological status was evaluated using the modified Japanese Orthopaedic Association (mJOA) score. Thoracic OLF for all patients were classed as bilateral type with a round morphology. Improvement of MEPs at least one muscle area was recorded in all patients following posterior decompression. A dural tear in one patient was the only observed complication. The mean recovery rate was 44.9 %, as calculated from mJOA scores at a mean follow-up period of 20 months. Microendoscopic posterior decompression combined with MEP monitoring can be used to treat patients with thoracic OLF. The optimal surgical indication is OLF at a single vertebral level and of a unilateral or bilateral nature, without comma and tram track signs, and a round morphology.

  10. Early versus late spinal decompression surgery in treatment of traumatic spinal cord injuries; a systematic review and meta-analysis

    PubMed Central

    Yousefifard, Mahmoud; Rahimi-Movaghar, Vafa; Baikpour, Masoud; Ghelichkhani, Parisa; Hosseini, Mostafa; Jafari, AliMoghadas; Aziznejad, Heidar; Tafakhori, Abbas

    2017-01-01

    Introduction: Despite the vast number of surveys, no consensus has been reached on the optimum timing of spinal decompression surgery. This systematic review and meta-analysis aimed to compare the effects of early and latespinal decompression surgery on neurologic improvement and post-surgical complications in patients with traumatic spinal cord injuries. Methods: Two independent reviewers carried out an extended search in electronic databases. Data of neurological outcome and post-surgery complication were extracted. Finally, pooled relative risk (RR) with a 95% confidence interval (CI) was reported for comparing of efficacy of early and late surgical decompression. Results: Eventually 22 studies were included. The pooled RRwas 0.77 (95% CI: 0.68-0.89)for at least one grade neurological improvement, and 0.84 (95% CI: 0.77-0.92)for at least two grade improvement. Pooled RR for surgical decompression performed within 12 hours after the injury was 0.26 (95% CI: 0.13-0.52; p<0.001), while it was 0.75 (95% CI: 0.63-0.90; p=0.002) when the procedure was performed within 24 hours, and 0.93 (95% CI: 0.76-1.14; p=0.48) when it was carried out in the first 72 hours after the injury. Surgical decompression performed within 24 hours after injury was found to be associated with significantly lower rates of post-surgical complications (RR=0.77; 95% CI: 0.68-0.86; p<0.001). Conclusion: The findings of this study indicate that early spinal decompression surgery can improve neurologic recovery and is associated with less post-surgical complications. The optimum efficacy is observed when the procedure is performed within 12 hours of the injury. PMID:28286844

  11. Upper extremity injury history, current pain rating, and health-related quality of life in female softball pitchers.

    PubMed

    Sauers, Eric L; Dykstra, Danelle L; Bay, R Curtis; Bliven, Kellie Huxel; Snyder, Alison R

    2011-02-01

    Throwing-related arm injuries are common in softball pitchers and may lead to diminished health-related quality of life (HRQOL). Arm symptoms such as pain have been reported to be more common in healthy overhead athletes than nonoverhead athletes. Furthermore, more frequent shoulder symptoms and lower shoulder function have been demonstrated in athletes with self-reported history of shoulder injury. To evaluate the relationship between arm injury history, current pain rating, and HRQOL assessed via 2 region-specific patient self-report scales in high school and college softball pitchers. Cross-sectional. High school and college athletic training facilities. 25 female softball pitchers (10 high school, 15 college; 18 ± 2 y, 169 ± 7.6 cm, 67.5 ± 10.3 kg). Self-reported arm injury history and rating of current pain and HRQOL were collected during the late season. A self-report questionnaire of arm injury history and current pain rating was used, and HRQOL was assessed via 2 region-specific scales: the Disabilities of the Arm, Shoulder, and Hand (DASH) and the Functional Arm Scale for Throwers© (FAST©). Correlational analysis was used to evaluate the relationships between arm injury history, current pain rating, and the DASH total score and sport module and the FAST total score, pitching module, and subscales. A history of arm injury from throwing was reported by 64% of participants, 31% of whom had to cease activity for more than 10 d. The most common site of arm time-loss injury was the shoulder (81%). Mild to severe shoulder pain during the competitive season was reported by 60% of respondents. The DASH and the FAST total scores were significantly correlated (r = .79, P < .001). Respondent rating of shoulder pain correlated significantly with the DASH total (r = .69) and sports module (r = .69) and the FAST total (r = .71), pitching module (r = .65), and pain (r = .73), impairment (r = .76), functional-limitation (r = .79), disability (r = .52), and societal

  12. Perceived Gender Ratings for High and Low Scorers on the Autism-Spectrum Quotient Consistent with the Extreme Male Brain Account of Autism

    PubMed Central

    Simons, Jessica M.; Maybery, Murray T.; Leung, Doris; Ng, Honey L. H.; Whitehouse, Andrew J. O.

    2015-01-01

    The Extreme Male Brain (EMB) theory posits that autistic traits are linked to excessive exposure to testosterone in utero. While findings from a number of studies are consistent with this theory, other studies have produced contradictory results. For example, some findings suggest that rather than being linked to hypermasculinization for males, or defeminization for females, elevated levels of autistic traits are instead linked to more androgynous physical features. The current study provided further evidence relevant to the EMB and androgony positions by comparing groups of males selected for high or low scores on the Autism-spectrum Quotient (AQ) as to the rated masculinity of their faces and voices, and comparable groups of females as to the rated femininity of their faces and voices. The voices of High-AQ males were rated as more masculine than those of Low-AQ males, while the faces of High-AQ females were rated as less feminine than those of Low-AQ females. There was no effect of AQ group on femininity ratings for female voices or on masculinity ratings for male faces. The results thus provide partial support for a link between high levels of autistic-like traits and hypermasculinization for males and defeminization for females, consistent with the EMB theory. PMID:26186689

  13. Perceived Gender Ratings for High and Low Scorers on the Autism-Spectrum Quotient Consistent with the Extreme Male Brain Account of Autism.

    PubMed

    Tan, Diana Weiting; Russell-Smith, Suzanna N; Simons, Jessica M; Maybery, Murray T; Leung, Doris; Ng, Honey L H; Whitehouse, Andrew J O

    2015-01-01

    The Extreme Male Brain (EMB) theory posits that autistic traits are linked to excessive exposure to testosterone in utero. While findings from a number of studies are consistent with this theory, other studies have produced contradictory results. For example, some findings suggest that rather than being linked to hypermasculinization for males, or defeminization for females, elevated levels of autistic traits are instead linked to more androgynous physical features. The current study provided further evidence relevant to the EMB and androgony positions by comparing groups of males selected for high or low scores on the Autism-spectrum Quotient (AQ) as to the rated masculinity of their faces and voices, and comparable groups of females as to the rated femininity of their faces and voices. The voices of High-AQ males were rated as more masculine than those of Low-AQ males, while the faces of High-AQ females were rated as less feminine than those of Low-AQ females. There was no effect of AQ group on femininity ratings for female voices or on masculinity ratings for male faces. The results thus provide partial support for a link between high levels of autistic-like traits and hypermasculinization for males and defeminization for females, consistent with the EMB theory.

  14. Decompression sickness in breath-hold divers: a review.

    PubMed

    Lemaitre, Frederic; Fahlman, Andreas; Gardette, Bernard; Kohshi, Kiyotaka

    2009-12-01

    Although it has been generally assumed that the risk of decompression sickness is virtually zero during a single breath-hold dive in humans, repeated dives may result in a cumulative increase in the tissue and blood nitrogen tension. Many species of marine mammals perform extensive foraging bouts with deep and long dives interspersed by a short surface interval, and some human divers regularly perform repeated dives to 30-40 m or a single dive to more than 200 m, all of which may result in nitrogen concentrations that elicit symptoms of decompression sickness. Neurological problems have been reported in humans after single or repeated dives and recent necropsy reports in stranded marine mammals were suggestive of decompression sickness-like symptoms. Modelling attempts have suggested that marine mammals may live permanently with elevated nitrogen concentrations and may be at risk when altering their dive behaviour. In humans, non-pathogenic bubbles have been recorded and symptoms of decompression sickness have been reported after repeated dives to modest depths. The mechanisms implicated in these accidents indicate that repeated breath-hold dives with short surface intervals are factors that predispose to decompression sickness. During deep diving, the effect of pulmonary shunts and/or lung collapse may play a major role in reducing the incidence of decompression sickness in humans and marine mammals.

  15. Neurovascular Bundle Decompression without Excessive Dissection for Tarsal Tunnel Syndrome

    PubMed Central

    KIM, Kyongsong; ISU, Toyohiko; MORIMOTO, Daijiro; SASAMORI, Toru; SUGAWARA, Atsushi; CHIBA, Yasuhiro; ISOBE, Masahiro; KOBAYASHI, Shiro; MORITA, Akio

    2014-01-01

    Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the posterior tibial nerve and its branches in the tarsal tunnel. We present our less invasive surgical treatment of TTS in 69 patients (116 feet) and their clinical outcomes. The mean follow-up period was 64.6 months. With the patient under local anesthesia we use a microscope to perform sharp dissection of the flexor retinaculum and remove the connective tissues surrounding the posterior tibial nerve and vessels. To prevent postoperative adhesion and delayed neuropathy, decompression is performed to achieve symptom improvement without excessive dissection. Decompression is considered complete when the patient reports intraoperative symptom abatement and arterial pulsation is sufficient. The sensation of numbness and/or pain and of foreign substance adhesion was reduced in 92% and 95% of our patients, respectively. In self-assessments, 47 patients (68%) reported the treatment outcome as satisfactory, 15 (22%) as acceptable, and 7 (10%) were dissatisfied. Of 116 feet, 4 (3%) required re-operation, initial decompression was insufficient in 2 feet and further decompression was performed; in the other 2 feet improvement was achieved by decompression of the distal tarsal tunnel. Our surgical method involves neurovascular bundle decompression to obtain sufficient arterial pulsation. As we use local anesthesia, we can confirm symptom improvement intraoperatively, thereby avoiding unnecessary excessive dissection. Our method is simple, safe, and without detailed nerve dissection and it prevents postoperative adhesion. PMID:25367582

  16. Neurovascular bundle decompression without excessive dissection for tarsal tunnel syndrome.

    PubMed

    Kim, Kyongsong; Isu, Toyohiko; Morimoto, Daijiro; Sasamori, Toru; Sugawara, Atsushi; Chiba, Yasuhiro; Isobe, Masahiro; Kobayashi, Shiro; Morita, Akio

    2014-01-01

    Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the posterior tibial nerve and its branches in the tarsal tunnel. We present our less invasive surgical treatment of TTS in 69 patients (116 feet) and their clinical outcomes. The mean follow-up period was 64.6 months. With the patient under local anesthesia we use a microscope to perform sharp dissection of the flexor retinaculum and remove the connective tissues surrounding the posterior tibial nerve and vessels. To prevent postoperative adhesion and delayed neuropathy, decompression is performed to achieve symptom improvement without excessive dissection. Decompression is considered complete when the patient reports intraoperative symptom abatement and arterial pulsation is sufficient. The sensation of numbness and/or pain and of foreign substance adhesion was reduced in 92% and 95% of our patients, respectively. In self-assessments, 47 patients (68%) reported the treatment outcome as satisfactory, 15 (22%) as acceptable, and 7 (10%) were dissatisfied. Of 116 feet, 4 (3%) required re-operation, initial decompression was insufficient in 2 feet and further decompression was performed; in the other 2 feet improvement was achieved by decompression of the distal tarsal tunnel. Our surgical method involves neurovascular bundle decompression to obtain sufficient arterial pulsation. As we use local anesthesia, we can confirm symptom improvement intraoperatively, thereby avoiding unnecessary excessive dissection. Our method is simple, safe, and without detailed nerve dissection and it prevents postoperative adhesion.

  17. Survival rate and neurodevelopmental outcome of extremely premature babies: an 8-year experience of an Italian single neonatal tertiary care center.

    PubMed

    Uccella, Sara; De Carli, Agnese; Sirgiovanni, Ida; Schiavolin, Paola; Damiano, Giuseppe; Ghirardi, Beatrice; Maglioli Carpano, Francesca; Bassi, Laura; Gangi, Silvana; Picciolini, Odoardo; Fumagalli, Monica; Mosca, Fabio

    2015-12-29

    Extremely preterm babies are at major risk for adverse neurodevelopmental outcome, being the gestational age (GA) the main determinant for a good-quality survival. Aim of this retrospective study was to investigate the neurodevelopmental outcome in a population of extremely preterm babies admitted to a single neonatal tertiary care unit over an 8-year period. All babies born between 23+0 and 25+6 weeks of GA from January 2003 until December 2010 were retrospectively enrolled. Perinatal and neonatal variables were recorded. Motor and cognitive development was assessed using the neurofunctional scale (NFS) and the Griffith's scales at 2 years. Fifty-five out of 122 infants survived to discharge. Survival rates doubled for each additional gestational week from 23 to 25: 16%, 38% and 74% at 23, 24 and 25 weeks GA respectively. Forty-six infants were evaluated at 2 years. A poor cognitive and motor outcome was observed in all babies born at 23 weeks. Griffith's general quotient (GQ) was ≥76 in 62% and ≥88 in 33% of babies born between 24 and 25 weeks. No severe motor disabilities were found in 81% of babies born between 24 and 25 weeks. Preterm premature rupture of membranes, absence of prenatal steroids, intrauterine growth restriction, male, lower GA and major brain abnormalities at magnetic resonance imaging (MRI) were significantly associated with worse NFS and lower mean GQ at 2 years of age. GA, gender and abnormal MRI findings remained significantly associated with impaired NFS at the multivariate analysis. Survival rates and neurodevelopmental outcome improved with each week of GA. These results are relevant for clinicians counselling families facing an unavoidable extremely preterm birth.

  18. Lower extremity soft tissue reconstruction and amputation rates in patients with open tibial fractures in Sweden during 1998–2010

    PubMed Central

    2014-01-01

    Background The rates of soft tissue reconstruction and amputation after open tibial fractures have not been studied on a national perspective. We aimed to determine the frequency of soft tissue coverage after open tibial fracture as well as primary and secondary amputation rates. Methods Data on all patients (> = 15 years) admitted to hospital with open tibial fractures were extracted from the Swedish National Patient Register (1998–2010). All surgical procedures, re-admissions, and mechanisms of injury were analysed accordingly. The risk of amputation was calculated using logistic regression (adjusted for age, sex, mechanism of injury, reconstructive surgery and fixation method). The mean follow-up time was 6 (SD 3.8) years. Results Of 3,777 patients, 342 patients underwent soft tissue reconstructive surgery. In total, there were 125 amputations. Among patients with no reconstructive surgery, 2% (n = 68 patients) underwent amputation. In an adjusted analysis, patients older than 70 years (OR = 2.7, 95%, CI = 1.1-6) and those who underwent reconstructive surgery (OR = 3.1, 95% CI = 1.6-5.8) showed higher risk for amputation. Fixations other than intramedullary nailing (plate, external fixation, closed reduction and combination) as the only method were associated with a significant higher risk for amputation (OR 5.1-14.4). Reconstruction within 72 hours (3 days) showed better results than reconstruction between 4–90 days (p = 0.04). Conclusions The rate of amputations after open tibial fractures is low (3.6%). There is a higher risk for amputations with age above 70 (in contrast: male sex and tissue reconstruction are rather indicators for more severe soft tissue injuries). Only a small proportion of open tibial fractures need soft tissue reconstructive surgery. Reconstruction with free or pedicled flap should be performed within 72 hours whenever possible. PMID:25323662

  19. Extreme-rate capable and highly stable SiCO-TiO2 hybrids for Li ion battery anodes.

    PubMed

    Behera, Shantanu K; Raj, Rishi

    2013-10-25

    A novel hybrid material for Li ion battery anodes, synthesized from polysiloxane-derived SiCO and nanoparticulate TiO2, exhibited specific capacity in excess of 850 mA h g(-1), fully recoverable capacity after cycling at severe current densities, as high as 20,000 mA g(-1) or 300 C rate, and exceptional stability beyond 1000 charge discharge cycles without capacity fading. Microscopy of the anodes after 3000 cycles showed no degradation or loss of materials.

  20. Neurologic decompression sickness following cabin pressure fluctuations at high altitude.

    PubMed

    Auten, Jonathan D; Kuhne, Michael A; Walker, Harlan M; Porter, Henry O

    2010-04-01

    Decompression sickness (DCS) occurs in diving, altitude chamber exposures, and unpressurized or depressurized high-altitude flights. Because DCS takes many forms, in-flight cases may be misinterpreted as hypoxia, hyperventilation, or viral illness, with resulting failure to respond appropriately. In this case, a 28-yr-old male pilot of a single-seat, tactical aircraft experienced 12 rapid pressure fluctuations while flying at 43,000 ft above sea level. He had no symptoms and decided to complete the flight, which required an additional 2 h in the air. Approximately 1 h later he began to experience fatigue, lightheadedness, and confusion, which he interpreted as onset of a viral illness. However, symptoms progressed to visual, cognitive, motor, and sensory degradations and it was with some difficulty that he landed safely at his destination. Neurologic DCS was suspected on initial evaluation by flight line medical personnel because of the delayed onset and symptom progression. He was transferred to a local Emergency Department and noted to have altered mental status, asymmetric motor deficits, and non-dermatomal paresthesias of the upper and lower extremities. Approximately 3.5 h after the incident and 2.5 h after the onset of symptoms he began hyperbaric oxygen therapy. He received partial relief at 30 min of the Navy DiveTable 6 and full resolution at 90 min; there were no recurrent symptoms at a 1-yr follow-up. This case highlights the importance of early recognition of in-flight DCS symptoms and landing as soon as possible rather than as soon as practical in all likely scenarios.

  1. Observed Rates of Lower Extremity Stress Fractures After Implementation of the Army Physical Readiness Training Program at JBSA Fort Sam Houston.

    PubMed

    Chalupa, Robyn L; Aberle, Curtis; Johnson, Anthony E

    2016-01-01

    Millions of dollars are lost each year to the US military in medical discharges from injuries sustained in the initial training of recruits. Most medical discharges in recruits are related to musculoskeletal overuse injuries, including stress fractures. Any strategies that can reduce injury rates are also likely to reduce rates of medical discharge. This study evaluated the Army Physical Readiness Training (PRT) program which was established to provide a method of physical fitness training that would reduce the number of preventable injuries. We conducted a retrospective study to evaluate the number of lower extremity stress fractures that were diagnosed in the 6 months prior to and 6 months following the implementation of the PRT program. Electronic medical records were queried for specific diagnoses of stress fractures to the pelvis, femoral neck, femoral shaft, tibia, fibula, tarsals and metatarsals. The observed number of diagnoses in each time period were compared using the χ² method. Decrease was shown not only in the overall occurrence of stress fractures, but specifically in the occurrence of stress fractures of the femoral neck, femoral shaft, and tarsals. Our study was able to show a correlation between the PRT program and a decrease in the observed occurrence of lower extremity stress fractures.

  2. Bubble nucleation in H2O-CO2 bearing basaltic melts: results of high temperature decompression experiments

    NASA Astrophysics Data System (ADS)

    Le Gall, N.; Pichavant, M.; Burgisser, A.

    2012-12-01

    Previous experiments have shown that mechanisms of basalt degassing are strongly contrasted when gas bubbles are present or when they are absent. Thus, experimental information on the kinetics of bubble nucleation in basaltic melts is needed, and high temperature decompression experiments have been investigated. All experiments used PST-9 basaltic pumice from Stromboli as starting material. The sample was fused in air at 1400°C for 3h and then cylinders (l up to 10mm, d 2.5 and 5mm) were cored. Synthesis experiments were performed to produce the volatile-bearing melts to be used in the decompression experiments. Glass cores, distilled H2O and Ag2C2O4 were loaded in AuPd capsules. Three different H2O/CO2 were introduced, corresponding to XH2Oin=1 (#1: only H2O dissolved in glass), 0.55 (#2: high dissolved H2O/CO2), 0 (#3: low dissolved H2O/CO2). The synthesis experiments were ran at 1200°C during about 40h in an internally heated vessel pressurized with Ar-H2. The synthesized crystal- and bubble-free glasses were cut in 2 parts: one for the decompression experiments and the other for the analysis. Decompression experiments were conducted at a fast rate of 39kPa/s, exceptionally of 77.8kPa/s, at 1200°C from an initial pressure (Pin) of 200MPa and to final pressures (Pf) of 200, 150, 100 and 50MPa. Experiments to 25MPa are in progress. Each run included 3 capsules, corresponding to the 3 XH2Oin conditions of glass synthesis, allowing results for the 3 H2O/CO2 to be directly compared. Charges were rapid-quenched immediately after attainment of Pf. Textures were analyzed by X-ray microtomography, and volatile concentrations and spatial distributions in pre- and post-decompression glasses were determined by FTIR. Pre-decompression glasses have homogeneous volatile contents and distributions. They divide into 3 compositional groups consistent with their XH2Oin conditions of synthesis: group #1 (average H2O content=4.82wt%, average CO2 content=0ppm), group #2 (2.15wt

  3. Submarine Rescue Decompression Procedure from Hyperbaric Exposures up to 6 Bar of Absolute Pressure in Man: Effects on Bubble Formation and Pulmonary Function

    PubMed Central

    Blatteau, Jean-Eric; Hugon, Julien; Castagna, Olivier; Meckler, Cédric; Vallée, Nicolas; Jammes, Yves; Hugon, Michel; Risberg, Jan; Pény, Christophe

    2013-01-01

    Recent advances in submarine rescue systems have allowed a transfer under pressure of crew members being rescued from a disabled submarine. The choice of a safe decompression procedure for pressurised rescuees has been previously discussed, but no schedule has been validated when the internal submarine pressure is significantly increased i.e. exceeding 2.8 bar absolute pressure. This study tested a saturation decompression procedure from hyperbaric exposures up to 6 bar, the maximum operating pressure of the NATO submarine rescue system. The objective was to investigate the incidence of decompression sickness (DCS) and clinical and spirometric indices of pulmonary oxygen toxicity. Two groups were exposed to a Nitrogen-Oxygen atmosphere (pO2 = 0.5 bar) at either 5 bar (N = 14) or 6 bar (N = 12) for 12 h followed by 56 h 40 min resp. 60 h of decompression. When chamber pressure reached 2.5 bar, the subjects breathed oxygen intermittently, otherwise compressed air. Repeated clinical examinations, ultrasound monitoring of venous gas embolism and spirometry were performed during decompression. During exposures to 5 bar, 3 subjects had minor subjective symptoms i.e. sensation of joint discomfort, regressing spontaneously, and after surfacing 2 subjects also experienced joint discomfort disappearing without treatment. Only 3 subjects had detectable intravascular bubbles during decompression (low grades). No bubbles were detected after surfacing. About 40% of subjects felt chest tightness when inspiring deeply during the initial phase of decompression. Precordial burning sensations were reported during oxygen periods. During decompression, vital capacity decreased by about 8% and forced expiratory flow rates decreased significantly. After surfacing, changes in the peripheral airways were still noticed; Lung Diffusion for carbon monoxide was slightly reduced by 1% while vital capacity was normalized. The procedure did not result in serious symptoms of DCS or

  4. Submarine rescue decompression procedure from hyperbaric exposures up to 6 bar of absolute pressure in man: effects on bubble formation and pulmonary function.

    PubMed

    Blatteau, Jean-Eric; Hugon, Julien; Castagna, Olivier; Meckler, Cédric; Vallée, Nicolas; Jammes, Yves; Hugon, Michel; Risberg, Jan; Pény, Christophe

    2013-01-01

    Recent advances in submarine rescue systems have allowed a transfer under pressure of crew members being rescued from a disabled submarine. The choice of a safe decompression procedure for pressurised rescuees has been previously discussed, but no schedule has been validated when the internal submarine pressure is significantly increased i.e. exceeding 2.8 bar absolute pressure. This study tested a saturation decompression procedure from hyperbaric exposures up to 6 bar, the maximum operating pressure of the NATO submarine rescue system. The objective was to investigate the incidence of decompression sickness (DCS) and clinical and spirometric indices of pulmonary oxygen toxicity. Two groups were exposed to a Nitrogen-Oxygen atmosphere (pO2 = 0.5 bar) at either 5 bar (N = 14) or 6 bar (N = 12) for 12 h followed by 56 h 40 min resp. 60 h of decompression. When chamber pressure reached 2.5 bar, the subjects breathed oxygen intermittently, otherwise compressed air. Repeated clinical examinations, ultrasound monitoring of venous gas embolism and spirometry were performed during decompression. During exposures to 5 bar, 3 subjects had minor subjective symptoms i.e. sensation of joint discomfort, regressing spontaneously, and after surfacing 2 subjects also experienced joint discomfort disappearing without treatment. Only 3 subjects had detectable intravascular bubbles during decompression (low grades). No bubbles were detected after surfacing. About 40% of subjects felt chest tightness when inspiring deeply during the initial phase of decompression. Precordial burning sensations were reported during oxygen periods. During decompression, vital capacity decreased by about 8% and forced expiratory flow rates decreased significantly. After surfacing, changes in the peripheral airways were still noticed; Lung Diffusion for carbon monoxide was slightly reduced by 1% while vital capacity was normalized. The procedure did not result in serious symptoms of DCS or

  5. Population structure and growth rates at biogeographic extremes: a case study of the common cockle, Cerastoderma edule (L.) in the Barents Sea.

    PubMed

    Genelt-Yanovskiy, Evgeny; Poloskin, Alexey; Granovitch, Andrei; Nazarova, Sophia; Strelkov, Petr

    2010-01-01

    A descriptive study of population structure, growth rates and shell morphometry was conducted on nine intertidal populations of the infaunal bivalve Cerastoderma edule in the Murmansk coast of the Barents Sea. Year-to-year population dynamics was analyzed during 2002-2006 on a tidal flat Dalniy Plaj (eastern Murmansk coast). The region constitutes the northern extremes of C. edule range where populations occupied the middle to low intertidal zone and were characterized by low densities. The distribution of age groups and unstable age structure across years in the cockle populations suggest irregular recruitment. Growth rates and shell morphometry showed little variation across the populations studied, and there were no gradient changes from the west to the east parts of Murmansk coast.

  6. Experimental respiratory decompression sickness in sheep.

    PubMed

    Atkins, C E; Lehner, C E; Beck, K A; Dubielzig, R R; Nordheim, E V; Lanphier, E H

    1988-09-01

    Respiratory decompression sickness (RDCS, "the chokes") is a potentially lethal consequence of ambient pressure reduction. Lack of a clearly suitable animal model has impeded understanding of this condition. RDCS, unaccompanied by central nervous system signs, occurred in 17 of 18 unanesthetized sheep exposed to compressed air at 230 kPa (2.27 ATA) for 22 h, returned to normal pressure for approximately 40 min, and taken to simulated altitude (0.75 ATA, 570 Torr). Respiratory signs, including tachypnea, sporadic apnea, and labored breathing, were accompanied by precordial Doppler ultrasound evidence of marked venous bubble loading. Pulmonary arterial pressures exceeded 30 Torr in five catheterized sheep that died or became moribund. Hypoxemia (arterial Po2 less than 40 Torr), neutropenia, and thrombocytopenia were observed. Peribronchovascular edema was the most prominent necropsy finding. Chest radiography indicated interstitial edema in most affected sheep. High body weight and catheterization predisposed the sheep to severe RDCS. It appears that this protocol reliably provides a useful animal model for studies of RDCS and obstructive pulmonary hypertension, that the precipitating event is massive pulmonary embolization by bubbles, and that venous bubbles, detected by Doppler ultrasound, can signal impending RDCS.

  7. Surgical options in ICH including decompressive craniectomy.

    PubMed

    Mitchell, Patrick; Gregson, Barbara A; Vindlacheruvu, Raghu R; Mendelow, A David

    2007-10-15

    Intracerebral haemorrhage (ICH) accounts for 15 to 20% of strokes. The condition carries a higher morbidity and mortality than occlusive stroke. Despite considerable research effort, no therapeutic modality either medical or surgical has emerged with clear evidence of benefit other than in rare aneurysmal cases. Intracerebral haemorrhages can be divided into those that arise from pre-existing macroscopic vascular lesions - so called "ictohaemorrhagic lesions", and those that do not; the latter being the commoner. Most of the research that has been done on the benefits of surgery has been in this latter group. Trial data available to date precludes a major benefit from surgical evacuation in a large proportion of cases however there are hypotheses of benefit still under investigation, specifically superficial lobar ICH treated by open surgical evacuation, deeper ICH treated with minimally invasive surgical techniques, and decompressive craniectomy. When an ICH arises from an ictohaemorrhagic lesion, therapy has two goals: to treat the effects of the acute haemorrhage and to prevent a recurrence. Three modalities are available for treating lesions to prevent recurrence: stereotactic radiosurgery, endovascular embolisation, and open surgical resection. As with ICH without an underlying lesion there is no evidence to support surgical removal of the haemorrhage in most cases. An important exception is ICHs arising from intracranial aneurysms where there is good evidence to support evacuation of the haematoma as well as repair of the aneurysm.

  8. A systematic review of factitious decompression sickness.

    PubMed

    Kenedi, Christopher; Sames, Christopher; Paice, Rhonda

    2013-01-01

    We present a case of factitious decompression sickness (DCS) involving a patient emergently treated at a hyperbaric medicine facility in New Zealand. Patients with factitious disorder feign illnesses such as DCS in order to receive care and attention despite the lack of an underlying illness. Other studies have suggested that 0.6% to as many as 9.3% of hospital admissions are factitious in nature. Therefore we believe that factitious DCS is occurring more often than hyperbaric clinicians suspect. DCS can be life-threatening, and hyperbaric medicine clinicians will almost always "err on the side of caution" when patients are referred with symptoms of DCS. Because DCS can be diagnosed based on subjective symptoms and self-reported history, there are opportunities for factitious patients to receive hyperbaric therapy. The costs associated with factitious DCS include transport, staff resources and preventing patients with treatable conditions from accessing the hyperbaric chamber. We performed a systematic review of the literature and found eight additional reported cases of confirmed or suspected factitious DCS. We report our findings and recommendations for hyperbaric medicine specialists regarding the recognition and management of factitious DCS.

  9. Monotherapeutic High-Dose-Rate Brachytherapy for Prostate Cancer: Five-Year Results of an Extreme Hypofractionation Regimen With 54 Gy in Nine Fractions

    SciTech Connect

    Yoshioka, Yasuo; Konishi, Koji; Sumida, Iori; Takahashi, Yutaka; Isohashi, Fumiaki; Ogata, Toshiyuki; Koizumi, Masahiko; Yamazaki, Hideya; Nonomura, Norio; Okuyama, Akihiko; Inoue, Takehiro

    2011-06-01

    Purpose: To evaluate an extreme hypofractionation regimen with 54 Gy in nine fractions provided by high-dose-rate (HDR) brachytherapy as monotherapy for prostate cancer by reporting 5-year clinical results. Methods and Materials: Between 1996 and 2005, 112 patients with localized prostate cancer were treated with HDR brachytherapy without external beam radiotherapy. Of the 112 patients, 15 were considered low risk, 29 intermediate risk, and 68 as high risk. The prescribed dose was uniformly 54 Gy in nine fractions within 5 days. Of the 112 patients, 94 also received hormonal therapy. The median follow-up time was 5.4 years. Results: All the patients safely completed the treatment regimen. The 5-year prostate-specific antigen (PSA) failure-free, local control, disease-free survival, and overall survival rate was 83%, 97%, 87%, and 96%, respectively. The 5-year PSA failure-free rate for low-, intermediate-, and high-risk patients was 85% (95% confidence interval, 66-100%), 93% (95% confidence interval, 83-100%), and 79% (95% confidence interval, 69-89%), respectively. The significant prognostic factors for PSA failure were the initial PSA level (p = .029) and younger age (p = .019). The maximal toxicities observed were Grade 3 using the Common Terminology Criteria for Adverse Events, version 3.0, for both acute and late toxicity (6 and 3 patients had acute and late Grade 3 toxicity, respectively). Late Grade 2 toxicity was observed in 13 patients. Conclusion: Monotherapeutic HDR brachytherapy with an extreme hypofractionation regimen of 54 Gy in nine fractions associated with hormonal therapy was feasible, and its toxicity was acceptable. The interim tumor control rate at a median 5.4 years was promising, even for patients with locally advanced disease. This dose-fractionation scheme might be referred to by other terms, such as stereotactic body radiotherapy. Studies with longer follow-up periods and from multiple institutions are needed to confirm the efficacy of

  10. Suprapedicular Foraminal Endoscopic Approach to Lumbar Lateral Recess Decompression Surgery to Treat Degenerative Lumbar Spinal Stenosis.

    PubMed

    Wang, Ya-Peng; Zhang, Wei; Li, Bao-Li; Sun, Ya-Peng; Ding, Wen-Yuan; Shen, Yong

    2016-11-28

    BACKGROUND To discuss the strategy of suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression and evaluate the safety and effectiveness of this strategy. MATERIAL AND METHODS Complete clinical information of 52 cases of lumbar lateral recess decompression with therapy of suprapedicular foraminal endoscopic approach were analyzed during the period from February 2010 to April 2014 in the Third Hospital of Hebei. All patients were followed up for 24 months, and VAS, JOA, ODI, and LRD were compared between preoperative and postoperative therapy and changes of FA. Intraoperative and postoperative complications were recorded and the safety of the surgery was evaluated. The surgical "excellent" and "good" rates were evaluated using MacNab score. RESULTS VAS scores for lumbago and leg pain at 3, 6, 12, and 24 months after surgery were significantly lower than before surgery (p<0.05). JOA scores at 12 and 24 months after surgery were significantly higher than before surgery (p<0.05). ODI at 12 and 24 months after surgery were significantly lower than before surgery (p<0.05). LRD after surgery was higher (p<0.05), and FA was lower than before surgery. CONCLUSIONS Use of the suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression is safe and effective, and this minimally invasive treatment can achieve satisfactory results, especially for elderly patients with complicated underlying diseases.

  11. Evidence for the initiation of decompression sickness by exposure to intense underwater sound.

    PubMed

    Tal, Dror; Shachar-Bener, Hofit; Hershkovitz, Dov; Arieli, Yehuda; Shupak, Avi

    2015-09-01

    Mass stranding of cetaceans (whales and dolphins), in close association with the activity of naval sonar systems, has been reported on numerous occasions. Necropsy showed bubble-associated lesions similar to those described in human decompression sickness (DCS). We examined the hypothesis that exposure to underwater sound may potentiate DCS. Rats were subjected to immersion and simulated dives with and without simultaneous acoustic transmissions at pressure levels and frequencies of 204 dB/8 kHz and 183.3 dB/15 kHz. DCS severity was assessed using the rotating wheel method. Recording of somatosensory evoked potentials (SSEPs) was employed under general anesthesia as an electrophysiological measure of neurologic insult. A significantly higher rate of decompression sickness was found among animals exposed to the 204-dB/8-kHz sound field. Significantly higher pathological SSEPs scores were noted for both underwater sound protocols. Pathological SSEPs scores in animals immersed during the acoustic transmissions, but without changes in ambient pressure, were comparable to those observed in animals exposed to the dive profile. The results demonstrate induction of neurological damage by intense underwater sound during immersion, with a further deleterious effect when this was combined with decompression stress. The study outcome has potential implications for human diving safety and may provide an explanation for the mass stranding of cetaceans purportedly associated with sonar activity. Copyright © 2015 the American Physiological Society.

  12. The autonomic effects of cardiopulmonary decompression sickness in swine using principal dynamic mode analysis.

    PubMed

    Bai, Yan; Selvaraj, Nandakumar; Petersen, Kyle; Mahon, Richard; Cronin, William A; White, Joseph; Brink, Peter R; Chon, Ki H

    2013-10-01

    Methods to predict onset of cardiopulmonary (CP) decompression sickness (DCS) would be of great benefit to clinicians caring for stricken divers. Principal dynamic mode (PDM) analysis of the electrocardiogram has been shown to provide accurate separation of the sympathetic and parasympathetic tone dynamics. Nine swine (Sus scrofa) underwent a 15-h saturation dive at 184 kPa (60 ft. of saltwater) in a hyperbaric chamber followed by dropout decompression, whereas six swine, used as a control, underwent a 15-h saturation dive at 15 kPa (5 ft. of saltwater). Noninvasive electrocardiograms were recorded throughout the experiment and autonomic nervous system dynamics were evaluated by heart rate series analysis using power spectral density (PSD) and PDM methods. We observed a significant increase in the sympathetic and parasympathetic tones using the PDM method on average 20 min before DCS onset following a sudden induction of decompression. Parasympathetic activities remained elevated, but the sympathetic modulation was significantly reduced at onset of cutis and CP DCS signs, as reported by a trained observer. Similar nonsignificant observations occurred during PSD analysis. PDM observations contrast with previous work showing that neurological DCS resulted in a >50% reduction in both sympathetic and parasympathetic tone. Therefore, tracking dynamics of the parasympathetic tones via the PDM method may allow discrimination between CP DCS and neurological DCS, and this significant increase in parasympathetic tone has potential use as a marker for early diagnosis of CP DCS.

  13. Early cranioplasty may improve outcome in neurological patients with decompressive craniectomy.

    PubMed

    Bender, Andreas; Heulin, Sandrine; Röhrer, Stefan; Mehrkens, Jan-Hinnerk; Heidecke, Volkmar; Straube, Andreas; Pfefferkorn, Thomas

    2013-01-01

    Decompressive craniectomy is an effective therapy to relieve intractable intracranial hypertension following acute brain injury. However, little is known about the optimal timing for cranioplasties in the sub-acute phase. The objective of the present study was to analyse the effect of cranioplasty timing on neurological outcomes. Single-centre observational study. One hundred and forty-seven consecutive patients with decompressive craniectomy and cranioplasty during the course of inpatient neurorehabilitation were identified by means of a retrospective hospital database search. This database contains the following prospectively-entered weekly scores: Barthel-Index (BI), Functional Independence Measure (FIM) and Coma Remission Scale (CRS). Additional clinical data were taken retrospectively from patient charts. Regression analysis was used to identify factors that influenced the end-of-rehabilitation outcome. Patients with shorter delays to cranioplasty (<86 days) had a better functional outcome than patients with longer delays of >85 days (60 ± 29.5 versus 25 ± 24.1 BI points; p < 0.01, respectively). Age, pre-operative BI and CRS scores were additional independent outcome factors. Complication rates were not different between early and late cranioplasty groups. Patients with decompressive craniectomy for management of intracranial hypertension may benefit from early cranioplasty.

  14. Therapeutic effects of segmental resection and decompression combined with joint prosthesis on continuous knee osteoarthritis

    PubMed Central

    Xue, Junlai; Wang, Changhong; Liu, Peng; Xie, Xiangchun; Qi, Shan

    2014-01-01

    Objective: To observe the therapeutic effects of segmental resection and decompression combined with joint prosthesis on continuous knee osteoarthritis (OA). Methods: A total of 130 patients with knee OA were selected and randomly divided into an observation group and a control group (n=65). The control group was treated by segmental resection in combination with joint prosthesis, and the observation group was treated by segmental resection and decompression combined with joint prosthesis. They were followed-up for three months. Results: All patients underwent successful surgeries during which no severe complications occurred. During the follow-up period, the overall effective rates of the observation group and the control group were 93.8% and 78.5% respectively, which were not statistically significantly different (p < 0.05). The observation group was significantly less prone to patellar instability, infection and deep vein thrombosis compared with the control group (P < 0.05). On the same day after surgery, the knee joint scores and functional scores of the two groups were similar, which evidently increased three months later, with significant intra-group and inter-group differences (p < 0.05). Conclusion: Combining segmental resection and decompression with joint prosthesis gave rise to satisfactory short-term prognosis by effectively improving the flexion and extension of injured knee and by decreasing complications, thus being worthy of promotion in clinical practice. PMID:25674115

  15. Evidence for the initiation of decompression sickness by exposure to intense underwater sound

    PubMed Central

    Tal, Dror; Shachar-Bener, Hofit; Hershkovitz, Dov; Arieli, Yehuda

    2015-01-01

    Mass stranding of cetaceans (whales and dolphins), in close association with the activity of naval sonar systems, has been reported on numerous occasions. Necropsy showed bubble-associated lesions similar to those described in human decompression sickness (DCS). We examined the hypothesis that exposure to underwater sound may potentiate DCS. Rats were subjected to immersion and simulated dives with and without simultaneous acoustic transmissions at pressure levels and frequencies of 204 dB/8 kHz and 183.3 dB/15 kHz. DCS severity was assessed using the rotating wheel method. Recording of somatosensory evoked potentials (SSEPs) was employed under general anesthesia as an electrophysiological measure of neurologic insult. A significantly higher rate of decompression sickness was found among animals exposed to the 204-dB/8-kHz sound field. Significantly higher pathological SSEPs scores were noted for both underwater sound protocols. Pathological SSEPs scores in animals immersed during the acoustic transmissions, but without changes in ambient pressure, were comparable to those observed in animals exposed to the dive profile. The results demonstrate induction of neurological damage by intense underwater sound during immersion, with a further deleterious effect when this was combined with decompression stress. The study outcome has potential implications for human diving safety and may provide an explanation for the mass stranding of cetaceans purportedly associated with sonar activity. PMID:26133802

  16. Effects of Decompression Treatment for Controlling the Powderpost Beetle, Lyctus africanus Lesne, (Coleoptera: Lyctinae)

    PubMed Central

    Nakai, Kazushi; Hiraku, Tatsuya; Fujimoto, Izumi; Yoshimura, Tsuyoshi

    2016-01-01

    The efficacy of decompression treatment as a non-destructive method to control larvae of the powderpost beetle, Lyctus africanus Lesne, was evaluated in the laboratory using various combinations of two pressure levels, 1.1 kPa and 40 kPa, and three temperature levels, 20, 25, and 40 °C. Larval mortality generally depended on weight reduction while decreases in the oxygen level had relatively little effect. The lower pressure, 1.1 kPa, significantly affected mortality, and no larvae survived after 12 h of this pressure treatment, at 25 °C. The average body weight was reduced with treatment time and temperature, and the reduction rate at 25 °C was higher than that at the lower temperature, 20 °C. Effects on larvae of the higher pressure treatment, 40 kPa, with a CO2 gas purge, were tested to determine the feasibility of decompression treatment in the manufacturing process. Although higher pressure resulted in low mortality, the body weight was dramatically decreased using the CO2 purge. These results present important information on the possibility of using decompression treatment for wood products. PMID:27429007

  17. Effects of Decompression Treatment for Controlling the Powderpost Beetle, Lyctus africanus Lesne, (Coleoptera: Lyctinae).

    PubMed

    Nakai, Kazushi; Hiraku, Tatsuya; Fujimoto, Izumi; Yoshimura, Tsuyoshi

    2016-07-15

    The efficacy of decompression treatment as a non-destructive method to control larvae of the powderpost beetle, Lyctus africanus Lesne, was evaluated in the laboratory using various combinations of two pressure levels, 1.1 kPa and 40 kPa, and three temperature levels, 20, 25, and 40 °C. Larval mortality generally depended on weight reduction while decreases in the oxygen level had relatively little effect. The lower pressure, 1.1 kPa, significantly affected mortality, and no larvae survived after 12 h of this pressure treatment, at 25 °C. The average body weight was reduced with treatment time and temperature, and the reduction rate at 25 °C was higher than that at the lower temperature, 20 °C. Effects on larvae of the higher pressure treatment, 40 kPa, with a CO₂ gas purge, were tested to determine the feasibility of decompression treatment in the manufacturing process. Although higher pressure resulted in low mortality, the body weight was dramatically decreased using the CO₂ purge. These results present important information on the possibility of using decompression treatment for wood products.

  18. Suprapedicular Foraminal Endoscopic Approach to Lumbar Lateral Recess Decompression Surgery to Treat Degenerative Lumbar Spinal Stenosis

    PubMed Central

    Wang, Ya-peng; Zhang, Wei; Li, Bao-li; Sun, Ya-peng; Ding, Wen-yuan; Shen, Yong

    2016-01-01

    Background To discuss the strategy of suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression and evaluate the safety and effectiveness of this strategy. Material/Methods Complete clinical information of 52 cases of lumbar lateral recess decompression with therapy of suprapedicular foraminal endoscopic approach were analyzed during the period from February 2010 to April 2014 in the Third Hospital of Hebei. All patients were followed up for 24 months, and VAS, JOA, ODI, and LRD were compared between preoperative and postoperative therapy and changes of FA. Intraoperative and postoperative complications were recorded and the safety of the surgery was evaluated. The surgical “excellent” and “good” rates were evaluated using MacNab score. Results VAS scores for lumbago and leg pain at 3, 6, 12, and 24 months after surgery were significantly lower than before surgery (p<0.05). JOA scores at 12 and 24 months after surgery were significantly higher than before surgery (p<0.05). ODI at 12 and 24 months after surgery were significantly lower than before surgery (p<0.05). LRD after surgery was higher (p<0.05), and FA was lower than before surgery. Conclusions Use of the suprapedicular foraminal endoscopic approach to lumbar lateral recess decompression is safe and effective, and this minimally invasive treatment can achieve satisfactory results, especially for elderly patients with complicated underlying diseases. PMID:27890911

  19. A prototype of pixel readout ASIC in 65 nm CMOS technology for extreme hit rate detectors at HL-LHC

    NASA Astrophysics Data System (ADS)

    Paternò, A.; Pacher, L.; Monteil, E.; Loddo, F.; Demaria, N.; Gaioni, L.; De Canio, F.; Traversi, G.; Re, V.; Ratti, L.; Rivetti, A.; Da Rocha Rolo, M.; Dellacasa, G.; Mazza, G.; Marzocca, C.; Licciulli, F.; Ciciriello, F.; Marconi, S.; Placidi, P.; Magazzù, G.; Stabile, A.; Mattiazzo, S.; Veri, C.

    2017-02-01

    This paper describes a readout ASIC prototype designed by the CHIPIX65 project, part of RD53, for a pixel detector at HL-LHC . A 64×64 matrix of 50×50μm2 pixels is realised. A digital architecture has been developed, with particle efficiency above 99.5% at 3 GHz/cm2 pixel rate, trigger frequency of 1 MHz and 12.5μsec latency. Two analog front end designs, one synchronous and one asynchronous, are implemented. Charge is measured with 5-bit precision, analog dead-time below 1%. The chip integrates for the first time many of the components developed by the collaboration in the past, including the Digital-to-Analog converters, Bandgap reference, Serializer, sLVS drivers, and analog Front Ends. Irradiation tests on these components proved their reliability up to 600 Mrad.

  20. Simple and Fast Continuous Estimation Method of Respiratory Frequency During Sleep using the Number of Extreme Points of Heart Rate Time Series

    NASA Astrophysics Data System (ADS)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

    It is reported that frequency component of approximately 0.25Hz of heart rate time series (RSA) is corresponding to the respiratory frequency. In this paper, we proposed that continuous estimation method of respiratory fequency during sleep using the number of extreme points of heart rate time series in real time. Equation for calculation of the method is very simple and the method can continuously calculate frequency by window width of about 18 beats. To evaluate accuracy of proposal method, RSA frequency was calculated using proposal method from the heart rate time series during supine rest. Result, minimum error rate was observed when RSA had time lag for about 11s and error rate was about 13.8%. Result of estimating RSA frequency time series during sleep, it varied regularly during non-REM and varied irregularly during REM. This result is similar as report of previous study about respiratory variability during sleep. Therefore, it is considered that proposal method possible to apply respiratory monitoring system during sleep.

  1. Gut fermentation seems to promote decompression sickness in humans.

    PubMed

    de Maistre, Sébastien; Vallee, Nicolas; Gempp, Emmanuel; Louge, Pierre; Duchamp, Claude; Blatteau, Jean-Eric

    2016-10-01

    Massive bubble formation after diving can lead to decompression sickness (DCS) that can result in neurological disorders. In experimental dives using hydrogen as the diluent gas, decreasing the body's H2 burden by inoculating hydrogen-metabolizing microbes into the gut reduces the risk of DCS. In contrast, we have shown that gut bacterial fermentation in rats on a standard diet promotes DCS through endogenous hydrogen production. Therefore, we set out to test these experimental results in humans. Thirty-nine divers admitted into our hyperbaric center with neurological DCS (Affected Divers) were compared with 39 healthy divers (Unaffected Divers). Their last meal time and composition were recorded. Gut fermentation rate was estimated by measuring breath hydrogen 1-4 h after the dive. Breath hydrogen concentrations were significantly higher in Affected Divers (15 ppm [6-23] vs. 7 ppm [3-12]; P = 0.0078). With the use of a threshold value of 16.5 ppm, specificity was 87% [95% confidence interval (CI) 73-95] for association with neurological DCS onset. We observed a strong association between hydrogen values above this threshold and an accident occurrence (odds ratio = 5.3, 95% CI 1.8-15.7, P = 0.0025). However, high fermentation potential foodstuffs consumption was not different between Affected and Unaffected Divers. Gut fermentation rate at dive time seemed to be higher in Affected Divers. Hydrogen generated by fermentation diffuses throughout the body and could increase DCS risk. Prevention could be helped by excluding divers who are showing a high fermentation rate, by eliminating gas produced in gut, or even by modifying intestinal microbiota to reduce fermentation rate during a dive. Copyright © 2016 the American Physiological Society.

  2. Improved image decompression for reduced transform coding artifacts

    NASA Technical Reports Server (NTRS)

    Orourke, Thomas P.; Stevenson, Robert L.

    1994-01-01

    The perceived quality of images reconstructed from low bit rate compression is severely degraded by the appearance of transform coding artifacts. This paper proposes a method for producing higher quality reconstructed images based on a stochastic model for the image data. Quantization (scalar or vector) partitions the transform coefficient space and maps all points in a partition cell to a representative reconstruction point, usually taken as the centroid of the cell. The proposed image estimation technique selects the reconstruction point within the quantization partition cell which results in a reconstructed image which best fits a non-Gaussian Markov random field (MRF) image model. This approach results in a convex constrained optimization problem which can be solved iteratively. At each iteration, the gradient projection method is used to update the estimate based on the image model. In the transform domain, the resulting coefficient reconstruction points are projected to the particular quantization partition cells defined by the compressed image. Experimental results will be shown for images compressed using scalar quantization of block DCT and using vector quantization of subband wavelet transform. The proposed image decompression provides a reconstructed image with reduced visibility of transform coding artifacts and superior perceived quality.

  3. Joint pain and Doppler-detectable bubbles in altitude (Hypobaric) decompression

    NASA Technical Reports Server (NTRS)

    Powell, Michael R.

    1993-01-01

    The observation that altitude decompression sickness (DCS) is associated with pain in the lower extremities is not new, although it is not a consistent finding. DCS in divers is generally in the upper body, an effect often attributed to non-loading of the body while immersed. In caisson workers, DCS is reported more in the lower extremities. Surprisingly, many researchers do not mention the location of DCS joint pain, apparently considering it to be random. This is not the case for the tissue ratios encountered in studying decompression associated with simulated EVA. In NASA/JSC tests, altitude DCS generally presented first in either the ankle, knee, or hip (83 percent = 73/88). There was a definite statistical relation between the maximum Spencer precordial Doppler Grade and the incidence of DCS in the extremity, although this is not meant to imply a casual relation between circulating gas bubbles and joint pain. The risk of DCS with Grade 4 was considerably higher than that of Grades 0 to 3. The DCS risk was independent of the 'tissue ratio.' There was a predominance of lower extremity DCS even when exercise was performed with the upper body. The reason for these locations we hypothesize to be attributed to the formation of tissue gas micronuclei from kinetic and tensile forces (stress-assisted nucleation) and are the result of the individuals ambulating in a 1g environment. Additionally, since these showers of Doppler bubbles can persist for hours, it is difficult to imagine that they are emanating solely from tendons and ligaments, the supposed site of joint pain. This follows from Henry's law linking the volume of joint tissue (the solvent) and the solubility coefficient of inert gas; there is volumetrically insufficient connective tissue to produce the prolonged release of gas bubbles. If gas bubbles are spawned and released from connective tissue, their volume is increased by those from muscle tissue. Therefore, the nexus between Doppler-detectable gas

  4. Joint pain and Doppler-detectable bubbles in altitude (Hypobaric) decompression

    NASA Technical Reports Server (NTRS)

    Powell, Michael R.

    1993-01-01

    The observation that altitude decompression sickness (DCS) is associated with pain in the lower extremities is not new, although it is not a consistent finding. DCS in divers is generally in the upper body, an effect often attributed to non-loading of the body while immersed. In caisson workers, DCS is reported more in the lower extremities. Surprisingly, many researchers do not mention the location of DCS joint pain, apparently considering it to be random. This is not the case for the tissue ratios encountered in studying decompression associated with simulated EVA. In NASA/JSC tests, altitude DCS generally presented first in either the ankle, knee, or hip (83 percent = 73/88). There was a definite statistical relation between the maximum Spencer precordial Doppler Grade and the incidence of DCS in the extremity, although this is not meant to imply a casual relation between circulating gas bubbles and joint pain. The risk of DCS with Grade 4 was considerably higher than that of Grades 0 to 3. The DCS risk was independent of the 'tissue ratio.' There was a predominance of lower extremity DCS even when exercise was performed with the upper body. The reason for these locations we hypothesize to be attributed to the formation of tissue gas micronuclei from kinetic and tensile forces (stress-assisted nucleation) and are the result of the individuals ambulating in a 1g environment. Additionally, since these showers of Doppler bubbles can persist for hours, it is difficult to imagine that they are emanating solely from tendons and ligaments, the supposed site of joint pain. This follows from Henry's law linking the volume of joint tissue (the solvent) and the solubility coefficient of inert gas; there is volumetrically insufficient connective tissue to produce the prolonged release of gas bubbles. If gas bubbles are spawned and released from connective tissue, their volume is increased by those from muscle tissue. Therefore, the nexus between Doppler-detectable gas

  5. Oxygen uptake, heart rate, perceived exertion, and integrated electromyogram of the lower and upper extremities during level and Nordic walking on a treadmill.

    PubMed

    Sugiyama, Koji; Kawamura, Mami; Tomita, Hisato; Katamoto, Shizuo

    2013-02-13

    The purpose of this study was to characterize responses in oxygen uptake ( V·O(2)), heart rate (HR), perceived exertion (OMNI scale) and integrated electromyogram (iEMG) readings during incremental Nordic walking (NW) and level walking (LW) on a treadmill. Ten healthy adults (four men, six women), who regularly engaged in physical activity in their daily lives, were enrolled in the study. All subjects were familiar with NW. Each subject began walking at 60 m/min for 3 minutes, with incremental increases of 10 m/min every 2 minutes up to 120 m/min V·O(2), V·(E) and HR were measured every 30 seconds, and the OMNI scale was used during the final 15 seconds of each exercise. EMG readings were recorded from the triceps brachii, vastus lateralis, biceps femoris, gastrocnemius, and tibialis anterior muscles. V·O(2) was significantly higher during NW than during LW, with the exception of the speed of 70 m/min (P < 0.01). V·E and HR were higher during NW than LW at all walking speeds (P < 0.05 to 0.001). OMNI scale of the upper extremities was significantly higher during NW than during LW at all speeds (P < 0.05). Furthermore, the iEMG reading for the VL was lower during NW than during LW at all walking speeds, while the iEMG reading for the BF and GA muscles were significantly lower during NW than LW at some speeds. These data suggest that the use of poles in NW attenuates muscle activity in the lower extremities during the stance and push-off phases, and decreases that of the lower extremities and increase energy expenditure of the upper body and respiratory system at certain walking speeds.

  6. Treatment of lumbar disc herniation by percutaneous laser disc decompression (PLDD) and modified PLDD

    NASA Astrophysics Data System (ADS)

    Chi, Xiao fei; Li, Hong zhi; Wu, Ru zhou; Sui, Yun xian

    2005-07-01

    Objective: To study the micro-invasive operative method and to compare the effect of treatment of PLDD and modified PLDD for Lumbar Disc Herniation. Method: Vaporized part of the nucleus pulposus in single or multiple point after acupuncture into lumbar disc, to reach the purpose of the decompression of the lumbar disc. Result: Among the 19 cases of the regular PLDD group, the excellent and good rate was 63.2%, and among the 40 cases of the modified PLDD group, the excellent and good rate was 82.5%. Conclusion: The modified PLDD has good effect on the treatment for lumbar disc herniation.

  7. Decompression induced bubble dynamics on ex vivo fat and muscle tissue surfaces with a new experimental set up.

    PubMed

    Papadopoulou, Virginie; Evgenidis, Sotiris; Eckersley, Robert J; Mesimeris, Thodoris; Balestra, Costantino; Kostoglou, Margaritis; Tang, Meng-Xing; Karapantsios, Thodoris D

    2015-05-01

    Vascular gas bubbles are routinely observed after scuba dives using ultrasound imaging, however the precise formation mechanism and site of these bubbles are still debated and growth from decompression in vivo has not been extensively studied, due in part to imaging difficulties. An experimental set-up was developed for optical recording of bubble growth and density on tissue surface area during hyperbaric decompression. Muscle and fat tissues (rabbits, ex vivo) were covered with nitrogen saturated distilled water and decompression experiments performed, from 3 to 0bar, at a rate of 1bar/min. Pictures were automatically acquired every 5s from the start of the decompression for 1h with a resolution of 1.75μm. A custom MatLab analysis code implementing a circular Hough transform was written and shown to be able to track bubble growth sequences including bubble center, radius, contact line and contact angles over time. Bubble density, nucleation threshold and detachment size, as well as coalescence behavior, were shown significantly different for muscle and fat tissues surfaces, whereas growth rates after a critical size were governed by diffusion as expected. Heterogeneous nucleation was observed from preferential sites on the tissue substrate, where the bubbles grow, detach and new bubbles form in turn. No new nucleation sites were observed after the first 10min post decompression start so bubble density did not vary after this point in the experiment. In addition, a competition for dissolved gas between adjacent multiple bubbles was demonstrated in increased delay times as well as slower growth rates for non-isolated bubbles. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Is there any dose-rate effect in breaking DNA strands by short pulses of extreme ultraviolet and soft x-ray radiation? (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Vyšín, Ludek; Burian, Tomáš; Ukraintsev, Egor; Davídková, Marie; Juha, Libor; Grisham, Michael E.; Heinbuch, Scott C.; Rocca, Jorge J.

    2017-05-01

    Possible dose-rate effects in a plasmid DNA exposed to pulsed extreme ultraviolet (XUV) and soft x-ray (SXR) water window radiation from two different table-top plasma-based sources was studied. Dose delivered to the target molecule was controlled by attenuating the incident photon flux with aluminum thin foils as well as varying the DNA/buffer-salt ratio in the irradiated sample. Irradiated samples were analyzed using the agarose gel electrophoresis. Some additional bands were identified in gel electrophoretograms as results of a DNA cross-linking. They were inspected by atomic force microscopy (AFM). Yields of single- and double-strand breaks (Gy-1 Da-1) were determined as a function of incident dose rate. Both yields decreased with a dose rate increasing. The ratio of single- and double-strand breaks exhibited only a slight increase at elevated dose rates. In conclusion, complex and/or clustered damages do not seem to be initiated under these irradiation conditions.

  9. Modified K-line in magnetic resonance imaging predicts insufficient decompression of cervical laminoplasty.

    PubMed

    Taniyama, Takashi; Hirai, Takashi; Yamada, Tsuyoshi; Yuasa, Masato; Enomoto, Mitsuhiro; Yoshii, Toshitaka; Kato, Tsuyoshi; Kawabata, Shigenori; Inose, Hiroyuki; Okawa, Atsushi

    2013-03-15

    A retrospective single-center study. To clarify preoperative factors predicting unsatisfactory indirect decompression after laminoplasty in patients with cervical spondylotic myelopathy. Many authors have shown that inadequate indirect decompression after laminoplasty can inhibit neural recovery and should be considered a complication. We previously demonstrated that residual anterior compression of the spinal cord (ACS) impaired recovery of upper extremity motor function. Although the K-line has been established as a predictive index indicating that laminoplasty is required in patients with ossification of the posterior longitudinal ligament, it remains unclear what preoperative factors can predict insufficient posterior cord decompression in patients with cervical spondylotic myelopathy. Forty-six consecutive patients who underwent laminoplasty for the treatment of cervical spondylotic myelopathy at our hospital were reviewed. A modified K-line was defined as the line connecting the midpoints of the spinal cord at C2 and C7 on a T1-weighted sagittal magnetic resonance image. We also determined the minimum interval between the tip of local kyphosis and a line connecting the midpoint of the cord at the level of the inferior endplates of C2 and C7 (INTmin) on the midsagittal image. Data analysis involved logistic regression and receiver operating characteristic curve analysis to select the most valuable index for predicting postoperative ACS. Ten patients had ACS immediately after laminoplasty. Logistic regression analysis showed that INTmin was a significant predictive factor for the occurrence of postoperative ACS (odds ratio = 0.485; 95% confidence interval = 0.29-0.81; P = 0.02). Receiver operating characteristic curve analysis showed an area under the curve of 0.871. A cutoff of 4.0 mm had a sensitivity of 80% and a specificity of 80.6% for prediction of postoperative ACS. The parameter INTmin correlated with the occurrence of postoperative ACS. A cutoff point

  10. Delayed Recompression for Decompression Sickness: Retrospective Analysis

    PubMed Central

    Hadanny, Amir; Fishlev, Gregori; Bechor, Yair; Bergan, Jacob; Friedman, Mony; Maliar, Amit; Efrati, Shai

    2015-01-01

    Introduction Most cases of decompression sickness (DCS) occur soon after surfacing, with 98% within 24 hours. Recompression using hyperbaric chamber should be administrated as soon as feasible in order to decrease bubble size and avoid further tissue injury. Unfortunately, there may be a significant time delay from surfacing to recompression. The time beyond which hyperbaric treatment is non effective is unclear. The aims of the study were first to evaluate the effect of delayed hyperbaric treatment, initiated more than 48h after surfacing for DCS and second, to evaluate the different treatment protocols. Methods From January 2000 to February 2014, 76 divers had delayed hyperbaric treatment (≥48h) for DCS in the Sagol center for Hyperbaric medicine and Research, Assaf-Harofeh Medical Center, Israel. Data were collected from their medical records and compared to data of 128 patients treated earlier than 48h after surfacing at the same hyperbaric institute. Results There was no significant difference, as to any of the baseline characteristics, between the delayed and early treatment groups. With respect to treatment results, at the delayed treatment divers, complete recovery was achieved in 76% of the divers, partial recovery in 17.1% and no improvement in 6.6%. Similar results were achieved when treatment started early, where 78% of the divers had complete recovery, 15.6% partial recovery and 6.2% no recovery. Delayed hyperbaric treatment using US Navy Table 6 protocol trended toward a better clinical outcome yet not statistically significant (OR=2.786, CI95%[0.896-8.66], p=0.07) compared to standard hyperbaric oxygen therapy of 90 minutes at 2 ATA, irrespective of the symptoms severity at presentation. Conclusions Late recompression for DCS, 48 hours or more after surfacing, has clinical value and when applied can achieve complete recovery in 76% of the divers. It seems that the preferred hyperbaric treatment protocol should be based on US Navy Table 6. PMID

  11. Dysphonia and dysphagia after anterior cervical decompression.

    PubMed

    Tervonen, Hanna; Niemelä, Mika; Lauri, Eija-Riitta; Back, Leif; Juvas, Anja; Räsänen, Pirjo; Roine, Risto P; Sintonen, Harri; Salmi, Tapani; Vilkman, S Erkki; Aaltonen, Leena-Maija

    2007-08-01

    In this paper, the authors investigate the effects of anterior cervical decompression (ACD) on swallowing and vocal function. The study comprised 114 patients who underwent ACD. The early group (50 patients) was examined immediately pre- and postoperatively, and the late group (64 patients) was examined at only 3 to 9 months postoperatively. Fifty age- and sex-matched patients from the Department of Otorhinolaryngology-Head and Neck Surgery who had not been intubated in the previous 5 years were used as a control group. All patients in the early and control groups were examined by a laryngologist; patients in the late group were examined by a laryngologist and a neurosurgeon. Videolaryngostroboscopy was performed in all members of the patient and control groups, and the function of the ninth through 12th cranial nerves were clinically evaluated. Data were collected concerning swallowing, voice quality, surgery results, and health-related quality of life. Patients with persistent dysphonia were referred for phoniatric evaluation and laryngeal electromyography (EMG). Those with persistent dysphagia underwent transoral endoscopic evaluation of swallowing function and videofluorography. Sixty percent of patients in the early group reported dysphonia and 69% reported dysphagia at the immediate postoperative visit. Unilateral vocal fold paresis occurred in 12%. The prevalence of both dysphonia and dysphagia decreased in both groups 3 to 9 months postoperatively. All six patients with vocal fold paresis in the early group recovered, and in the late group there were two cases of vocal fold paresis. The results of laryngeal EMG were abnormal in 14 of 16 patients with persistent dysphonia. Neither intraoperative factors nor age or sex had any effect on the occurrence of dysphonia, dysphagia, or vocal fold paresis. Most patients were satisfied with the surgical outcome. Dysphonia, dysphagia, and vocal fold paresis are common but usually transient complications of ACD

  12. Air break during preoxygenation and risk of altitude decompression sickness.

    PubMed

    Pilmanis, Andrew A; Webb, James T; Balldin, Ulf I; Conkin, Johnny; Fischer, Joseph R

    2010-10-01

    To reduce the risk of decompression sickness (DCS), current USAF U-2 operations require a 1-h preoxygenation (PreOx). An interruption of oxygen breathing with air breathing currently requires significant extension of the PreOx time. The purpose of this study was to evaluate the relationship between air breaks during PreOx and subsequent DCS and venous gas emboli (VGE) incidence, and to determine safe air break limits for operational activities. Volunteers performed 30 min of PreOx, followed by either a 10-min, 20-min, or 60-min air break, then completed another 30 min of PreOx, and began a 4-h altitude chamber exposure to 9144 m (30,000 ft). Subjects were monitored for VGE using echocardiography. Altitude exposure was terminated if DCS symptoms developed. Control data (uninterrupted 60-min PreOx) to compare against air break data were taken from the AFRL DCS database. At 1 h of altitude exposure, DCS rates were significantly higher in all three break in prebreathe (BiP) profiles compared to control (40%, 45%, and 47% vs. 24%). At 2 h, the 20-min and 60-min BiP DCS rates remained higher than control (70% and 69% vs. 52%), but no differences were found at 4 h. No differences in VGE rates were found between the BiP profiles and control. Increased DCS risk in the BiP profiles is likely due to tissue renitrogenation during air breaks not totally compensated for by the remaining PreOx following the air breaks. Air breaks of 10 min or more occurring in the middle of 1 h of PreOx may significantly increase DCS risk during the first 2 h of exposure to 9144 m when compared to uninterrupted PreOx exposures.

  13. Influence of decompression sickness on vasomotion of isolated rat vessels.

    PubMed

    Mazur, A; Lambrechts, K; Buzzacott, P; Wang, Q; Belhomme, M; Theron, M; Mansourati, J; Guerrero, F

    2014-06-01

    Several studies have demonstrated that endothelial function is impaired following a dive even without decompression sickness. During this study we determined the effect of decompression sickness on endothelium-dependent and independent vasoreactivity. For this purpose twenty-seven male Sprague-Dawley rats were submitted to a simulated dive up to 1,000 kPa absolute pressure and divided into 3 groups: safe diving without decompression sickness or dives provoking mild or severe sickness. A fourth control group remained at atmospheric pressure. Endothelium-dependent and independent vasomotion was assessed ex vivo by measuring isometric tension in rings of abdominal aorta and mesenteric arteries. Dose-response curves were obtained with phenylephrine, acetylcholine and sodium nitroprusside. Acetylcholine-induced relaxation was measured in the presence of L-NAME, indometacin or both of them at once.Contraction was significantly decreased after each protocol compared with the control rats. Additionally, the response in animals from the severe group was significantly different from that of the safe and mild groups. Dose response curves for acetylcholine alone and in the presence of inhibitors remained unchanged. We did not observe differences in endothelium-dependent vasodilation after diving or in the presence of decompression sickness. Contractile response to phenylephrine was progressively impaired with increased decompression stress. These results may indicate smooth muscle injury. © Georg Thieme Verlag KG Stuttgart · New York.

  14. Decompressing recompression chamber attendants during Australian submarine rescue operations.

    PubMed

    Reid, Michael P; Fock, Andrew; Doolette, David J

    2017-09-01

    Inside chamber attendants rescuing survivors from a pressurised, distressed submarine may themselves accumulate a decompression obligation which may exceed the limits of Defense and Civil Institute of Environmental Medicine tables presently used by the Royal Australian Navy. This study assessed the probability of decompression sickness (PDCS) for medical attendants supervising survivors undergoing oxygen-accelerated saturation decompression according to the National Oceanic and Atmospheric Administration (NOAA) 17.11 table. Estimated probability of decompression sickness (PDCS), the units pulmonary oxygen toxicity dose (UPTD) and the volume of oxygen required were calculated for attendants breathing air during the NOAA table compared with the introduction of various periods of oxygen breathing. The PDCS in medical attendants breathing air whilst supervising survivors receiving NOAA decompression is up to 4.5%. For the longest predicted profile (830 minutes at 253 kPa) oxygen breathing at 30, 60 and 90 minutes at 132 kPa partial pressure of oxygen reduced the air-breathing-associated PDCS to less than 3.1 %, 2.1% and 1.4% respectively. The probability of at least one incident of DCS among attendants, with consequent strain on resources, is high if attendants breathe air throughout their exposure. The introduction of 90 minutes of oxygen breathing greatly reduces the probability of this interruption to rescue operations.

  15. [The effects of electromagnetic radiation of extremely high frequency and low intensity on the growth rate of bacteria Escherichia coli and the role of medium pH].

    PubMed

    Tadevosian, A; Kalantarian, V; Trchunian, A

    2007-01-01

    It has been shown that coherent electromagnetic irradiation (EMI) of extremely high frequency (45-53 GHz) or millimeter waves (wavelength 5.6-6.7 mm) of low intensity (flux capacity 0.06 mW/cm2) of Escherichia coli K12, grown under anaerobic conditions during the fermentation of sugar (glucose) for 30 min or 1 h, caused a decrease in their growth rate, the maximum inhibitory effect being achieved at a frequency of 51.8 or 53 GHz. This effect depended on medium pH when the maximal action was determined at pH 7.5. In addition, separate 30-min of 1-h irradiation (frequency 51.8 or 53 GHz) of doubly distilled water or some inorganic ions contained in Tris-phosphate buffer where the cells were transferred induced oppositely directed changes in further growth of these bacteria under anaerobic conditions; irradiation of water caused a decrease in the growth rate of bacteria. A significant change in pH of water (0.5-1.5 unit) was induced by a 30-irradiation at a frequency of 49, 50.3, 51.8, or 53 GHz, when the initial pH value was 6.0 or 8.0, but not 7.5. These results indicate the changes in the properties of water and its role in the effects of EMI of extremely high frequency. The marked effect of EMI on bacteria disappeared upon repeated irradiation for 1 h at a frequency of 51.8 or 53 GHz with an interval of 2 hours. This result indicates some compensatory mechanisms in bacteria.

  16. Favourable outcome of posterior decompression and stabilization in lordosis for cervical spondylotic myelopathy: the spinal cord "back shift" concept.

    PubMed

    Denaro, Vincenzo; Longo, Umile Giuseppe; Berton, Alessandra; Salvatore, Giuseppe; Denaro, Luca

    2015-11-01

    Surgical management of patients with multilevel CSM aims to decompress the spinal cord and restore the normal sagittal alignment. The literature lacks of high level evidences about the best surgical approach. Posterior decompression and stabilization in lordosis allows spinal cord back shift, leading to indirect decompression of the anterior spinal cord. The purpose of this study was to investigate the efficacy of posterior decompression and stabilization in lordosis for multilevel CSM. 36 out of 40 patients were clinically assessed at a mean follow-up of 5, 7 years. Outcome measures included EMS, mJOA Score, NDI and SF-12. Patients were asked whether surgery met their expectations and if they would undergo the same surgery again. Bone graft fusion, instrumental failure and cervical curvature were evaluated. Spinal cord back shift was measured and correlation with EMS and mJOA score recovery rate was analyzed. All scores showed a significative improvement (p < 0.001), except the SF12-MCS (p > 0.05). Ninety percent of patients would undergo the same surgery again. There was no deterioration of the cervical alignment, posterior grafted bones had completely fused and there were no instrument failures. The mean spinal cord back shift was 3.9 mm (range 2.5-4.5 mm). EMS and mJOA recovery rates were significantly correlated with the postoperative posterior cord migration (P < 0.05). Posterior decompression and stabilization in lordosis is a valuable procedure for patients affected by multilevel CSM, leading to significant clinical improvement thanks to the spinal cord back shift. Postoperative lordotic alignment of the cervical spine is a key factor for successful treatment.

  17. [Clinical value of primary decompression operation for unilateral ureterocele with complete duplex system].

    PubMed

    Teranishi, Jun-ichi; Sato, Hiroyuki; Mori, Yoshiaki; Asanuma, Hiroshi; Shishido, Seiichiro

    2006-03-01

    To assess a value of decompression operation for a unilateral ureterocele with a complete duplex system as an initial procedure. We reviewed records of 33 pediatric patients with a unilateral ureterocele in a complete duplex system who underwent decompression operation between 1987 and 2000. We checked the patient operative age, followup period, position of the ureterocele, type of decompression operation, and additional operation. Furthermore we also checked postoperative vesicoureteral reflux (VUR) in patients who underwent transurethral incision (TUI). Mean operative age and followup period were 6 months old and 82 months. Of the patients, 22 underwent TUI and 11 underwent upper moiety operation (UMO). In the TUI group, 14 (63.6%) had postoperative VUR and 13 (59.0%) underwent additional operations. These rates were higher in the patients with ectopic ureteroceles than with intravesical ureteroceles. Most additional operations were undergone for the patients with postoperative VUR in TUI group by lower complete reconstructions without UMO. All patients with non-functioning upper moiety underwent heminephrectomy at the additional operations. In the other hand, in the UMO group, 3 (27.3%) had additional operation because of persistent VUR which was found preoperatively in lower moiety or contralateral renal unit. TUI was useful approach as an initial procedure for intravesical ureteroceles because of low additional operation rate. For ectopic ureteroceles with functioning upper moiety, TUI was high additional operation rate, but it was more useful initial operation of two-staged operation than UMO because of avoiding UMO, like heminephrectomy, at additional operation. UMO was low additional operation rate for ectopic ureteroceles without preoperative VUR of renal unit excluding upper moiety. Especially heminephrectomy was a useful approach as an initial procedure if upper moiety was non-functioning.

  18. Accessing ultra-high pressures and strain rates in the solid state: An experimental path to extreme materials science on the Omega and NIF lasers

    NASA Astrophysics Data System (ADS)

    Lorenz, K. Thomas

    2005-03-01

    A new approach to materials science at extreme pressures and strain rates has been developed on the Omega laser, using a ramped plasma piston drive. The laser drives a shock through a solid plastic reservoir that unloads at the rear free surface, expands across a vacuum gap, and stagnates on the metal sample under study. This produces a gently increasing ram pressure, compressing the sample nearly isentropically. The peak pressure on the sample, diagnosed with VISAR measurements, can be varied by adjusting the laser energy and pulse length, gap size, and reservoir density, and obeys a simple scaling relation.^1 This has been demonstrated at OMEGA at pressures to 200 GPa in Al foils. In an important application, using in-flight x-ray radiography, the material strength of solid-state samples at high pressure can be inferred by measuring the reductions in the growth rates (stabilization) of Rayleigh-Taylor (RT) unstable interfaces. RT instability measurements of solid Al-6061-T6 and vanadium, at pressures of 20-100 GPa and strain rates of 10^6 to 10^8 s-1, show clear material strength effects. High-pressure experimental designs based on this drive have been developed for the NIF laser, predicting that solid-state samples can be quasi-isentropically driven to pressures an order of magnitude higher than on Omega - accessing new regimes of dense, high-pressure matter. [1] J. Edwards et al., Phys. Rev. Lett., 92, 075002 (2004).

  19. The extreme solar cosmic ray particle event on 20 January 2005 and its influence on the radiation dose rate at aircraft altitude.

    PubMed

    Bütikofer, R; Flückiger, E O; Desorgher, L; Moser, M R

    2008-03-01

    In January 2005 toward the end of solar activity cycle 23 the Sun was very active. Between 15 and 20 January 2005, the solar active region NOAA AR 10720 produced five powerful solar flares. In association with this major solar activity several pronounced variations in the ground-level cosmic ray intensity were observed. The fifth of these flares (X7.1) produced energetic solar cosmic rays that caused a giant increase in the count rates of the ground-based cosmic ray detectors (neutron monitors). At southern polar neutron monitor stations the increase of the count rate reached several thousand percent. From the recordings of the worldwide network of neutron monitors, we determined the characteristics of the solar particle flux near Earth. In the initial phase of the event, the solar cosmic ray flux near Earth was extremely anisotropic. The energy spectrum of the solar cosmic rays was fairly soft during the main and the decay phase. We investigated also the flux of different secondary particle species in the atmosphere and the radiation dosage at flight altitude. Our analysis shows a maximum increment of the effective dose rate due to solar cosmic rays in the south polar region around 70 degrees S and 130 degrees E at flight altitude of almost three orders of magnitude.

  20. Extreme learning machine: a new alternative for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters.

    PubMed

    Liu, Zhijian; Li, Hao; Tang, Xindong; Zhang, Xinyu; Lin, Fan; Cheng, Kewei

    2016-01-01

    Heat collection rate and heat loss coefficient are crucial indicators for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, wasting too much time and manpower. To address this problem, we previously used artificial neural networks and support vector machine to develop precise knowledge-based models for predicting the heat collection rates and heat loss coefficients of water-in-glass evacuated tube solar water heaters, setting the properties measured by "portable test instruments" as the independent variables. A robust software for determination was also developed. However, in previous results, the prediction accuracy of heat loss coefficients can still be improved compared to those of heat collection rates. Also, in practical applications, even a small reduction in root mean square errors (RMSEs) can sometimes significantly improve the evaluation and business processes. As a further study, in this short report, we show that using a novel and fast machine learning algorithm-extreme learning machine can generate better predicted results for heat loss coefficient, which reduces the average RMSEs to 0.67 in testing.

  1. Pharmacological intervention against bubble-induced platelet aggregation in a rat model of decompression sickness

    PubMed Central

    Vallée, Nicolas; Ignatescu, Mihaela; Bourdon, Lionel

    2011-01-01

    Decompression sickness (DCS) with alterations in coagulation system and formation of platelet thrombi occurs when a subject is subjected to a reduction in environmental pressure. Blood platelet consumption after decompression is clearly linked to bubble formation in humans and offers an index for evaluating DCS severity in animal models. Previous studies highlighted a predominant involvement of platelet activation and thrombin generation in bubble-induced platelet aggregation (BIPA). To study the mechanism of the BIPA in DCS, we examined the effect of acetylsalicylic acid (ASA), heparin (Hep), and clopidogrel (Clo), with anti-thrombotic dose pretreatment in a rat model of DCS. Male Sprague-Dawley rats (n = 208) were randomly assigned to one experimental group treated before the hyperbaric exposure and decompression protocol either with ASA (3×100 mg·kg−1·day−1, n = 30), Clo (50 mg·kg−1·day−1, n = 60), Hep (500 IU/kg, n = 30), or to untreated group (n = 49). Rats were first compressed to 1,000 kPa (90 msw) for 45 min and then decompressed to surface in 38 min. In a control experiment, rats were treated with ASA (n = 13), Clo (n = 13), or Hep (n = 13) and maintained at atmospheric pressure for an equivalent period of time. Onset of DCS symptoms and death were recorded during a 60-min observation period after surfacing. DCS evaluation included pulmonary and neurological signs. Blood samples for platelet count (PC) were taken 30 min before hyperbaric exposure and 30 min after surfacing. Clo reduces the DCS mortality risk (mortality rate: 3/60 with Clo, 15/30 with ASA, 21/30 with Hep, and 35/49 in the untreated group) and DCS severity (neurological DCS incidence: 9/60 with Clo, 6/30 with ASA, 5/30 with Hep, and 12/49 in the untreated group). Clo reduced fall in platelet count and BIPA (−4,5% with Clo, −19.5% with ASA, −19,9% with Hep, and −29,6% in the untreated group). ASA, which inhibits the thromboxane A2 pathway, and Hep, which inhibits thrombin

  2. Spinal Epidural Hematoma after Thoracolumbar Posterior Fusion Surgery without Decompression for Thoracic Vertebral Fracture

    PubMed Central

    Minato, Tsuyoki; Miyagi, Masayuki; Saito, Wataru; Shoji, Shintaro; Nakazawa, Toshiyuki; Inoue, Gen; Imura, Takayuki; Minehara, Hiroaki; Matsuura, Terumasa; Kawamura, Tadashi; Namba, Takanori; Takahira, Naonobu; Takaso, Masashi

    2016-01-01

    We present a rare case of spinal epidural hematoma (SEH) after thoracolumbar posterior fusion without decompression surgery for a thoracic vertebral fracture. A 42-year-old man was hospitalized for a thoracic vertebral fracture caused by being sandwiched against his back on broken concrete block. Computed tomography revealed a T12 dislocation fracture of AO type B2, multiple bilateral rib fractures, and a right hemopneumothorax. Four days after the injury, in order to promote early orthostasis and to improve respiratory status, we performed thoracolumbar posterior fusion surgery without decompression; the patient had back pain but no neurological deficits. Three hours after surgery, he complained of acute pain and severe weakness of his bilateral lower extremities; with allodynia below the level of his umbilicus, postoperative SEH was diagnosed. We performed immediate revision surgery. After removal of the hematoma, his symptoms improved gradually, and he was discharged ambulatory one month after revision surgery. Through experience of this case, we should strongly consider the possibility of preexisting SEH before surgery, even in patients with no neurological deficits. We should also consider perioperative coagulopathy in patients with multiple trauma, as in this case. PMID:26989542

  3. The Risks of Scuba Diving: A Focus on Decompression Illness

    PubMed Central

    2014-01-01

    Decompression Illness includes both Decompression Sickness (DCS) and Pulmonary Overinflation Syndrome (POIS), subsets of diving-related injury related to scuba diving. DCS is a condition in which gas bubbles that form while diving do not have adequate time to be resorbed or “off-gassed,” resulting in entrapment in specific regions of the body. POIS is due to an overly rapid ascent to the surface resulting in the rupture of alveoli and subsequent extravasation of air bubbles into tissue planes or even the cerebral circulation. Divers must always be cognizant of dive time and depth, and be trained in the management of decompression. A slow and controlled ascent, plus proper control of buoyancy can reduce the dangerous consequences of pulmonary barotrauma. The incidence of adverse effects can be diminished with safe practices, allowing for the full enjoyment of this adventurous aquatic sport. PMID:25478296

  4. A computerized databank of decompression sickness incidence in altitude chambers

    NASA Technical Reports Server (NTRS)

    Conkin, Johnny; Bedahl, Sharon R.; Van Liew, Hugh D.

    1992-01-01

    This report describes a hypobaric decompression sickness databank (HDSD) for use with personal computers. The databank consolidates some of the decompression sickness (DCS) information that has accumulated from altitude chamber tests from 1942 to the present. The information was transcribed to a data collection form, screened for accuracy and duplication, and then added to the databank through a computer keyboard. The databank consists of two files; 63 fields contain details of the test conditions in the altitude chamber, the outcome of the test in terms of DCS and venous gas emboli, the physical characteristics of the group of subjects who underwent the test, and the denitrogenation procedures prior to decompression. The HDSD currently contains 378 records that represent 130,012 altitude exposures from 80 sources: scientific journal articles, government and contractor reports, and chapters from books.

  5. Decompression sickness in simulated Apollo-Soyuz space missions

    NASA Technical Reports Server (NTRS)

    Cooke, J. P.; Robertson, W. G.

    1974-01-01

    Apollo-Soyuz docking module atmospheres were evaluated for incidence of decompression sickness in men simulating passage from the Russian spacecraft atmosphere, to the U.S. spacecraft atmosphere, and then to the American space suit pressure. Following 8 hr of 'shirtsleeve' exposure to 31:69::O2:N2 gas breathing mixture, at 10 psia, subjects were 'denitrogenated' for either 30 or 60 min with 100% O2 prior to decompression directly to 3.7 psia suit equivalent while performing exercise at fixed intervals. Five of 21 subjects experienced symptoms of decompression sickness after 60 min of denitrogenation compared to 6 among 20 subjects after 30 min of denitrogenation. A condition of Grade I bends was reported after 60 min of denitrogenation, and 3 of these 5 subjects noted the disappearance of all symptoms of bends at 3.7 psia. After 30 min of denitrogenation, 2 out of 6 subjects developed Grade II bends at 3.7 psia.

  6. The risks of scuba diving: a focus on Decompression Illness.

    PubMed

    Hall, Jennifer

    2014-11-01

    Decompression Illness includes both Decompression Sickness (DCS) and Pulmonary Overinflation Syndrome (POIS), subsets of diving-related injury related to scuba diving. DCS is a condition in which gas bubbles that form while diving do not have adequate time to be resorbed or "off-gassed," resulting in entrapment in specific regions of the body. POIS is due to an overly rapid ascent to the surface resulting in the rupture of alveoli and subsequent extravasation of air bubbles into tissue planes or even the cerebral circulation. Divers must always be cognizant of dive time and depth, and be trained in the management of decompression. A slow and controlled ascent, plus proper control of buoyancy can reduce the dangerous consequences of pulmonary barotrauma. The incidence of adverse effects can be diminished with safe practices, allowing for the full enjoyment of this adventurous aquatic sport.

  7. [Clinical characterization and treatment of acute spinal cord decompression sickness after repeated dives].

    PubMed

    Li, Yan; Huang, Feng; Han, Tao; Zhou, Baoying; Lin, Kan; Zhang, Tianqiang

    2015-06-01

    To analyze and summarize the characteristics and treatment of acute spinal cord decompression sickness. To explore the factors that influence the treatment effect. 77 cases of acute spinal cord decompression sickness patients should be divided into 4 groups according to the pressurized treatment and drug treatment options. They were group I, group II, group III and group IV. At the same time they were get hyperbaric oxygen therapy and other treatment. The evaluation index, were Frankel function classification and paraplegia index. There were 17 factors that affected the treatment effect. The rate of early cure was 57.14% (44/77). The rate of late cure was 74.03% (57/77). Their difference was statistically significant (P<0.05). In 3 months and 1 year the cure rate of group IV and group B were the highest. But there was no difference between them(P>0.05). They were higher than group ii and group I (P<0.05). The Frankel function classification in 3months and 1 year in each group was higher than before treatment (P<0.05). The paraplegia index in 3 months and 1 year in each group was lower than before treatment (P<0.05). In 3 months and 1 year the Frankel function classification was increased gradually and the paraplegia index was decreased gradually in group I , group II, group III (P<0.05). In group IV and group III the Frankel function and the paraplegia index had not significant difference (P>0.05). Among the 17 factors that affect the treatment effect there are 9 factors that affect the proportion of the large. The first choice of treatment method for the patients with acute spinal cord decompression sickness would be group III. Drug therapy was also imporpant. At the same time the hyperbaric oxygen therapy and other treatments were taken. Although the cure rate was not high in this article. But most of the cure is within 3 months. Within 1 year.the cure rate still could be improved. 9 factors that affect the efficacy of acute spinal cord decompression sickness was

  8. Five-year outcome of surgical decompression of the lumbar spine without fusion.

    PubMed

    Mannion, Anne F; Denzler, R; Dvorak, J; Grob, D

    2010-11-01

    As the average life expectancy of the population increases, surgical decompression of the lumbar spine is being performed with increasing frequency. It now constitutes the most common type of lumbar spinal surgery in older patients. The present prospective study examined the 5-year outcome of lumbar decompression surgery without fusion. The group comprised 159 patients undergoing decompression for degenerative spinal disorders who had been participants in a randomised controlled trial of post-operative rehabilitation that had shown no between-group differences at 2 years. Leg pain and back pain intensity (0-10 graphic rating scale), self-rated disability (Roland Morris), global outcome of surgery (5-point Likert scale) and re-operation rates were assessed 5 years post-operatively. Ten patients had died before the 5-year follow-up. Of the remaining 149 patients, 143 returned a 5-year follow-up (FU) questionnaire (effective return rate excluding deaths, 96%). Their mean age was 64 (SD 11) years and 92/143 (64%) were men. In the 5-year follow-up period, 34/143 patients (24%) underwent re-operation (17 further decompressions, 17 fusions and 1 intradural drainage/debridement). In patients who were not re-operated, leg pain decreased significantly (p < 0.05) from before surgery to 2 months FU, after which there was no significant change up to 5 years. Low back pain also decreased significantly by 2 months FU, but then showed a slight, but significant (p < 0.05), gradual increase of <1 point by 5-year FU. Disability decreased significantly from pre-operative to 2 months FU and showed a further significant decrease at 5 months FU. Thereafter, it remained stable up to the 5-year FU. Pain and disability scores recorded after 5 years showed a significant correlation with those at earlier follow-ups (r = 0.53-0.82; p < 0.05). Patients who were re-operated at some stage over the 5-year period showed significantly worse final outcomes for leg pain and disability (p < 0.05). In

  9. Development and Validation of 1.3 ATA PO2-in-He Decompression Tables for the MK 16 MOD 1 UBA

    DTIC Science & Technology

    2012-03-22

    requirements: . No-decompression capability 40 - 200 fsw • Decompression dive capability 40 - 320 fsw • Repetitive diving capability 40 - 200 fsw ...min • Descent rate: 60 fsw /min • Ascent rate: 30 fsw /min • Up to 140 min total dive time per day The first program objective was to establish that...toe* separated by 30-minute surface intervals. The dives in each profi e we?e to depths of 120,160, or 200 fsw , with bottom times ranging from,15 S

  10. Expansion of bubbles under a pulsatile flow regime in decompressed ovine blood vessels.

    PubMed

    Arieli, Ran; Marmur, Abraham

    2016-02-01

    After decompression of ovine large blood vessels, bubbles nucleate and expand at active hydrophobic spots on their luminal aspect. These bubbles will be in the path of the blood flow within the vessel, which might replenish the supply of gas-supersaturated plasma in their vicinity and thus, in contrast with our previous estimations, enhance their growth. We used the data from our previous study on the effect of pulsatile flow in ovine blood vessels stretched on microscope slides and photographed after decompression from hyperbaric exposure. We measured the diameter of 46 bubbles in 4 samples taken from 3 blood vessels (pulmonary artery, pulmonary vein, and aorta) in which both a "multi-bubble active spot" (MBAS)--which produces several bubbles at a time, and at least one "single-bubble active spot" (SBAS)--which produces a single bubble at a time, were seen together. The linear expansion rate for diameter in SBAS ranged from 0.077 to 0.498 mm/min and in MBAS from 0.001 to 0.332 mm/min. There was a trend toward a reduced expansion rate for bubbles in MBAS compared with SBAS. The expansion rate for bubbles in an MBAS when it was surrounded by others was very low. Bubble growth is related to gas tension, and under a flow regime, bubbles expand from a diameter of 0.1 to 1mm in 2-24 min at a gas supersaturation of 620 kPa and lower. There are two phases of bubble development. The slow and disperse initiation of active spots (from nanobubbles to gas micronuclei) continues for more than 1h, whereas the fast increase in size (2-24 min) is governed by diffusion. Bubble-based decompression models should not artificially reduce diffusion constants, but rather take both phases of bubble development into consideration. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Allometric Scaling of Decompression Sickness Risk in Terrestrial Mammals

    DTIC Science & Technology

    2011-09-11

    bubble grades and patent foramen ovale [4-8]. However, where some studies have found a correlation, others refute those results [9, 10]. The only...Risk of decompression sickness with patent foramen ovale . Undersea and Hyperbaric Medicine, 1998. 25(3): p. 175-178. 5. Broome, J.R., A.J. Dutka, and...of patent foramen ovale is limited. British Medical Journal, 1994. 309: p. 743-744. 11. Lillo, R.S., E.C. Parker, and W.R. Porter, Decompression

  12. Allometric Scaling of Decompression Sickness Risk in Terrestrial Mammals

    DTIC Science & Technology

    2011-09-11

    activation, Doppler bubble grades and patent foramen ovale [4-8]. However, where some studies have found a correlation, others refute those results...Risk of decompression sickness with patent foramen ovale . Undersea and Hyperbaric Medicine, 1998. 25(3): p. 175-178. 5. Broome, J.R., A.J. Dutka...of patent foramen ovale is limited. British Medical Journal, 1994. 309: p. 743-744. 11. Lillo, R.S., E.C. Parker, and W.R. Porter, Decompression

  13. The 1990 Hypobaric Decompression Sickness Workshop: Summary and conclusions

    NASA Technical Reports Server (NTRS)

    Pilmanis, Andrew A.; Stegmann, Barbara J.; Scoggins, Terrell E.

    1992-01-01

    Decompression sickness resulting from exposure to the hypobaric environment was reviewed and discussed at a three day workshop in Oct. 1990. This milestone meeting, attended by over 50 participants representing the Dept. of Defense, NASA, ESA, and academia, updated the current understanding of altitude decompression sickness (DCS). Both research and operational aspects of this illness were addressed through presentations on the pathophysiology and clinical manifestations of DCS, its incidence in aviation and space operations, and existing and proposed measures for DCS prevention. Specific areas requiring further research were also identified. A summary is presented for the material given at the workshop.

  14. Meralgia paresthetica: etiology, diagnosis, and outcome of surgical decompression.

    PubMed

    Nahabedian, M Y; Dellon, A L

    1995-12-01

    Entrapment of the lateral femoral cutaneous (LFC) nerve as a source of anterolateral thigh dysesthesias has been recognized for 100 years. Despite this historic recognition, its diagnosis today is often delayed, and definitive treatment of refractory cases by surgical decompression rarely reported. This study describes 26 LFC entrapments in 23 patients whose etiologies include iliac crest bone graft harvesting, seat belt injury associated with motor vehicle accident, and diabetes. Twenty-two of the 23 patients (25 of the 26 entrapments) achieved good to excellent outcomes following surgical decompression of the LFC nerve.

  15. Cervical cord injury in patients with ankylosed spines: progressive paraplegia in two patients after posterior fusion without decompression.

    PubMed

    Sugimoto, Yoshihisa; Ito, Yasuo; Tanaka, Masato; Tomioka, Masao; Hasegawa, Yasuhiro; Nakago, Kie; Yagata, Yukihisa; Ozaki, Toshifumi

    2009-11-01

    Case report and clinical discussion. To describe technical pitfall to treat 2 cervical cord injuries, including dislocations in patients with ankylosed spine due to diffuse idiopathic skeletal hyperostosis (DISH) or ossification of the posterior longitudinal ligament (OPLL). DISH and OPLL are disease processes similar in pathology, which can lead to unexpected fractures due to low-energy trauma. In reported cases of fracture of the ankylosed spine in patients with DISH or OPLL, increasing lever arm and a grossly unstable fracture occurred. However, the actual surgical intervention for these fractures and spinal cord injuries was not discussed. We report 2 cervical cord injuries, including dislocations in patients with ankylosed spine due to DISH or OPLL. Two patients underwent posterior fusion without decompression; however, postoperative progressive paraplegia still occurred. There were 3 points in common: these patients had ankylosed spines due to DISH or OPLL; they were elderly and had spinal canal stenosis; and after undergoing posterior fusion without decompression, their bilateral, lower extremity palsies worsened after surgery. Cervical alignment was slightly different after posterior fusion, and this change concentrated in one segment because adjacent vertebral bodies were ankylosed, and thus, immoveable. Additionally, this stress caused infolding of the ligamentum flavum with resultant spinal cord compression. In these cases, we recommend posterior fusion and decompression such as laminoplasty to avoid worsening palsy.

  16. Transcriptome analysis of bull semen with extreme nonreturn rate: use of suppression-subtractive hybridization to identify functional markers for fertility.

    PubMed

    Lalancette, C; Thibault, C; Bachand, I; Caron, N; Bissonnette, N

    2008-04-01

    Spermatozoa are terminally differentiated cells produced during the complex process of spermatogenesis. Although the role of their residual RNA content is still being debated, this transcriptome may represent a fingerprint of spermatogenesis quality. In the present study, we undertook differential transcript profiling of spermatozoa from fertile bulls with extreme nonreturn rates (NRRs): a low-fertile group, and a high-fertile group. Using the suppression-subtractive hybridization technique in combination with macroarray analysis, we also identified novel genes. Both extreme NRR index groups retained redundant identity, such as ribosomal and mitochondrial sequences, at a statistically significant level. An elevated number of 12S, 18S, and Large Chain R rRNA gene copies were found in low-fertile bulls and validated in spermatozoa by quantitative RT-PCR for a small cohort of bulls with known fertility index. Whereas the high-NRR library exhibited a large proportion (29%) of transcripts associated with known functions (e.g., metabolism, signal transduction, translation, glycosylation, and protein degradation), only 10% of the low-NRR sequences did. This difference is also conveyed by two other categories: 17% Bovine Genome and 48% unknown in the high-NRR library, compared with 3% and 80%, respectively, in the low-NRR library. Some of the unknown transcripts are similar to expressed sequence tags detected in the male reproductive organ of certain plants and retain homology to a putative human protein. Whereas the individual transcriptome profiles may be useful in fertility assessment, these findings also suggest cross-species conservation, could contribute to a better understanding of spermatogenesis, and provide new insights regarding idiopathic infertility.

  17. The Sagittal Balance Does not Influence the 1 Year Clinical Outcome of Patients With Lumbar Spinal Stenosis Without Obvious Instability After Microsurgical Decompression.

    PubMed

    Bayerl, Simon Heinrich; Pöhlmann, Florian; Finger, Tobias; Onken, Julia; Franke, Jörg; Czabanka, Marcus; Woitzik, Johannes; Vajkoczy, Peter

    2015-07-01

    A retrospective study with retrospective and prospective inclusion of 100 patients. To determine whether the sagittal balance (SB) influences the clinical outcome of patients with degenerative lumbar spinal stenosis, who underwent microsurgical decompression. The SB has become a critical factor for clinical decision making in the surgical treatment of spinal degenerative diseases. However, a frequently recommended sagittal realignment of elderly, multimorbid patients is accompanied by a significant rate of complications. The influence of SB on the clinical outcome of patients with degenerative spinal stenosis, who undergo decompressive surgery is not well understood. The aim of this study was to explore whether the clinical outcome of these patients is related to the SB and whether patients with spinal stenosis and degenerative sagittal imbalance necessitate restoration of the SB in addition to microsurgical decompression. One hundred patients with lumbar spinal stenosis, who received microsurgical decompression, were retrospectively identified and classified according to the severity of sagittal imbalance: (1) normal balance group, (2) minor loss of balance group, and (3) major loss of balance group. Sagittal parameters were determined from preoperative lateral spinal radiographs. As outcome parameters, we analyzed pre- and postoperative visual analogue scales for leg and back pain, walking distance, Oswestry disability index, Roland and Morris disability questionnaire, Odom's criteria, and the SF-36 score. All groups significantly benefited from surgery concerning leg pain, back pain, and disability in every day's life. There was no difference in patients with decompensated sagittal imbalance compared to patients with normal SB regarding life quality 6 to 24 months after microsurgical decompression. Patients with symptomatic degenerative spinal stenosis and excluded major instability significantly benefit from microsurgical decompression regardless of their

  18. The effectiveness of percutaneous laser disc decompression for the prolapsed lumbar intervertebral disc

    NASA Astrophysics Data System (ADS)

    Mu, Ming Wei; Liu, Wei; Feng, Wei; Ma, Nan

    2009-07-01

    Objective: to investigate the role of associated factors in the effectiveness of laser treatment for prolapsed lumber intervertebral disc. Method: 302 prolapsed lumber intervertebral discs in 212 patients were treated with percutaneous laser disc decompression (PLDD). Patients were followed up by 12month, the associated factors which affecting the effectiveness of treatment, ie age, duration of illness were analyzed. Results: Punctual Success rate was 100%. After 12 month's follow up, 86% successful outcomes were obtained, in which 93% successful outcomes were obtained in patients less than 50 years old, 92% successful outcomes was obtained in the patients whose duration of illness less than 1 year.

  19. A randomised controlled trial of post-operative rehabilitation after surgical decompression of the lumbar spine

    PubMed Central

    Denzler, Raymond; Dvorak, Jiri; Müntener, Markus; Grob, Dieter

    2007-01-01

    Spinal decompression is the most common type of spinal surgery carried out in the older patient, and is being performed with increasing frequency. Physiotherapy (rehabilitation) is often prescribed after surgery, although its benefits compared with no formal rehabilitation have yet to be demonstrated in randomised control trials. The aim of this randomised controlled trial was to examine the effects on outcome up to 2 years after spinal decompression surgery of two types of postoperative physiotherapy compared with no postoperative therapy (self-management). Hundred and fifty-nine patients (100 men, 59 women; 65 ± 11 years) undergoing decompression surgery for spinal stenosis/herniated disc were randomised to one of the following programmes beginning 2 months post-op: recommended to “keep active” (CONTROL; n = 54); physiotherapy, spine stabilisation exercises (PT-StabEx; n = 56); physiotherapy, mixed techniques (PT-Mixed; n = 49). Both PT programmes involved 2 × 30 min sessions/week for up to 12 weeks, with home exercises. Pain intensity (0–10 graphic rating scale, for back and leg pain separately) and self-rated disability (Roland Morris) were assessed before surgery, before and after the rehabilitation phase (approx. 2 and 5 months post-op), and at 12 and 24 months after the operation. ‘Intention to treat’ analyses were used. At 24 months, 151 patients returned questionnaires (effective return rate, excluding 4 deaths, 97%). Significant reductions in leg and back pain and self-rated disability were recorded after surgery (P < 0.05). Pain showed no further changes in any group up to 24 months later, whereas disability declined further during the “rehabilitation” phase (P < 0.05) then stabilised, but with no significant group differences. 12 weeks of post-operative physiotherapy did not influence the course of change in pain or disability up to 24 months after decompression surgery. Advising patients to keep active by

  20. Comparison of results of retrocalcaneal decompression for retrocalcaneal bursitis and insertional achilles tendinosis with calcific spur.

    PubMed

    Watson, A D; Anderson, R B; Davis, W H

    2000-08-01

    Sixteen feet with retrocalcaneal bursitis (RB) and twenty-two feet with calcific Achilles insertional tendinosis (IAT-CS) underwent retrocalcaneal decompression after failure of nonoperative treatment. Follow-up evaluation at least two years after surgery included AOFAS Ankle-Hindfoot subscale scores, satisfaction, time until maximum symptomatic improvement, and radiographs. Statistically significant differences between the groups include the following: IAT-CS patients were older, required nearly twice the time to reach maximum symptomatic improvement, had lower satisfaction rates, had a lower pain score, and more frequently had shoewear restrictions. Radiographic recurrence did not correlate with outcome or symptomatic recurrence.

  1. Prospective outcomes evaluation after decompression with or without instrumented fusion for lumbar stenosis and degenerative Grade I spondylolisthesis.

    PubMed

    Ghogawala, Zoher; Benzel, Edward C; Amin-Hanjani, Sepideh; Barker, Fred G; Harrington, J Fred; Magge, Subu N; Strugar, John; Coumans, Jean-Valéry C E; Borges, Lawrence F

    2004-10-01

    There is considerable debate among spine surgeons regarding whether fusion should be used to augment decompressive surgery in patients with symptomatic lumbar spinal stenosis involving Grade I degenerative spondylolisthesis. The authors prospectively evaluated the outcomes of patients treated between 2000 and 2002 at two institutions to determine whether fusion improves functional outcome 1 year after surgery. Patients ranged in age from 50 to 81 years. They presented with degenerative Grade I (3- to 14-mm) spondylolisthesis and lumbar stenosis without gross instability (< 3 mm of motion at the level of subluxation). Those in whom previous surgery had been performed at the level of subluxation were excluded. Each patient completed Oswestry Disability Index (ODI) and Short Form-36 (SF-36) questionnaires preoperatively and at 6 to 12 months postoperatively. Some patients underwent decompression alone (20 cases), whereas others underwent decompression and posterolateral instrumentation-assisted fusion (14 cases), at the treating surgeon's discretion. Baseline demographic data, radiographic features, and ODI and SF-36 scores were similar in both groups. The 1-year fusion rate was 93%. Both forms of surgery independently improved outcome compared with baseline status, based on ODI and SF-36 physical component summary (PCS) results (p < 0.001). Decompression combined with fusion led to an improvement in ODI scores of 27.5 points, whereas decompression alone was associated with a 13.6-point increase (p = 0.02). Analysis of the SF-36 PCS data also demonstrated a significant intergroup difference (p = 0.003). Surgery substantially improved 1-year outcomes based on established outcomes instruments in patients with Grade I spondylolisthesis and stenosis. Fusion was associated with greater functional improvement.

  2. Hyperbaric oxygen pre-breathe modifies the outcome of decompression sickness.

    PubMed

    Butler, B D; Little, T; Cogan, V; Powell, M

    2006-01-01

    Deep sea divers, aviators and astronauts are at risk of decompression sickness when the ambient pressure reductions exceed a critical threshold. Venous bubbles associated with decompression sickness have the potential to react with the vascular membrane and adjacent blood products, eliciting an inflammatory cascade. Preventive measures usually involve careful decompression procedures to avoid or reduce bubble formation. De-nitrogenation with 100% oxygen pre-breathing as a preventive measure has been well established at least in altitude decompression exposures. The objective of this study was to determine the physiological and biochemical effects of Hyperbaric Oxygen Pre-breathe (HBOP) upon decompression from a hyperbaric exposure. Male Sprague-Dawley rats were randomly assigned to one of eight groups. Two experimental groups received HBOP at 1 and 18 hours prior to decompression, as compared with ground level oxygen or non-treated groups that still experienced decompression stress, and the associated non-decompressed controls. The results showed decreased extravascular lung water (pulmonary edema), bronchoalveolar lavage and pleural protein and arterial, broncho-alveolar lavage, and urine leukotriene E4 (LKE4) levels in both the 1Hr and 18Hr HBOP decompressed rats compared to non-oxygenated decompressed rats, as well as a decreased overall expression of signs of decompression sickness. This study indicates that HBOP-treated rats exhibit fewer signs and complications of decompression sickness compared with non-treated or ground level oxygen treated rats.

  3. 46 CFR Appendix A to Part 197 - Air No-Decompression Limits

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives...

  4. 46 CFR Appendix A to Part 197 - Air No-Decompression Limits

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives...

  5. 46 CFR Appendix A to Part 197 - Air No-Decompression Limits

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Air No-Decompression Limits A Appendix A to Part 197... STANDARDS GENERAL PROVISIONS Pt. 197, App. A Appendix A to Part 197—Air No-Decompression Limits The following table gives the depth versus bottom time limits for single, no-decompression, air dives...

  6. Pudendal nerve decompression in perineology : a case series

    PubMed Central

    Beco, Jacques; Climov, Daniela; Bex, Michèle

    2004-01-01

    Background Perineodynia (vulvodynia, perineal pain, proctalgia), anal and urinary incontinence are the main symptoms of the pudendal canal syndrome (PCS) or entrapment of the pudendal nerve. The first aim of this study was to evaluate the effect of bilateral pudendal nerve decompression (PND) on the symptoms of the PCS, on three clinical signs (abnormal sensibility, painful Alcock's canal, painful "skin rolling test") and on two neurophysiological tests: electromyography (EMG) and pudendal nerve terminal motor latencies (PNTML). The second aim was to study the clinical value of the aforementioned clinical signs in the diagnosis of PCS. Methods In this retrospective analysis, the studied sample comprised 74 female patients who underwent a bilateral PND between 1995 and 2002. To accomplish the first aim, the patients sample was compared before and at least one year after surgery by means of descriptive statistics and hypothesis testing. The second aim was achieved by means of a statistical comparison between the patient's group before the operation and a control group of 82 women without any of the following signs: prolapse, anal incontinence, perineodynia, dyschesia and history of pelvi-perineal surgery. Results When bilateral PND was the only procedure done to treat the symptoms, the cure rates of perineodynia, anal incontinence and urinary incontinence were 8/14, 4/5 and 3/5, respectively. The frequency of the three clinical signs was significantly reduced. There was a significant reduction of anal and perineal PNTML and a significant increase of anal richness on EMG. The Odd Ratio of the three clinical signs in the diagnosis of PCS was 16,97 (95% CI = 4,68 – 61,51). Conclusion This study suggests that bilateral PND can treat perineodynia, anal and urinary incontinence. The three clinical signs of PCS seem to be efficient to suspect this diagnosis. There is a need for further studies to confirm these preliminary results. PMID:15516268

  7. Altitude decompression sickness symptom resolution during descent to ground level.

    PubMed

    Muehlberger, Patrick M; Pilmanis, Andrew A; Webb, James T; Olson, James E

    2004-06-01

    Altitude decompression sickness (DCS) is a health risk associated with the conduct of high altitude airdrop operations, high altitude reconnaissance, future fighter operations, hypobaric chamber training, unpressurized flight, and extravehicular activity (EVA) in space. The treatment for DCS includes the provision of 100% oxygen (O2) at ground level (GLO) and/or hyperbaric oxygen therapy (HBO). In this paper we examine the effect of repressurization to ground level from hypobaric conditions on DCS symptoms. Timely recompression (descent at first recognition of any DCS symptom) may be a safe, effective treatment for the large majority of DCS symptoms. Data from altitude chamber exposures recorded in the Air Force Research Laboratory (AFRL) Altitude DCS Database were reviewed to determine the level of recompression required for complete resolution of 1,699 observed symptoms. Of the 1,699 DCS symptoms reviewed, 66 (3.9%) resolved at altitude, 117 (6.9%) resolved at ground level, and 1,433 (84.3%) resolved during descent. Increasing the pressure by 138 mmHg from the altitude of exposure where symptoms occurred resolved roughly 50% of symptoms. Little resolution of symptoms was noted with recompressions of < 50 mmHg. The greatest rate of symptom resolution occurred with recompressions of 50-250 mmHg. These findings support the concept that descent and postflight, ground-level oxygen may be sufficient to relieve the majority of altitude DCS symptoms. HBO may be reserved for serious, recurring, delayed, or refractory symptoms. The findings also suggest a need for further study of DCS symptom resolution.

  8. Safety of microvascular decompression for elderly patients with trigeminal neuralgia.

    PubMed

    Amagasaki, Kenichi; Watanabe, Saiko; Naemura, Kazuaki; Shono, Naoyuki; Nakaguchi, Hiroshi

    2016-02-01

    The present study compared the safety and efficacy of microvascular decompression (MVD) in groups of elderly patients and non-elderly patients with medically refractory trigeminal neuralgia (TN) and collected detailed perioperative data. Retrospective analysis of clinical data was performed in 99 patients who underwent MVD from May 2012 to June 2015. The outcome data from 27 MVD operations for 27 patients aged 70-80 years (mean 74.6 years) were compared with 72 MVD operations with 72 patients aged 25-69 years (mean 55.7 years). Preoperative comorbidities were recorded and postoperative worsening comorbidities and non-neurological complications were evaluated at discharge. Efficacy of the surgery and neurological complications were evaluated in July 2015. No decrease in activity of daily living was found in any patient. Complete pain relief without medication was achieved in 77.8% and partial pain relief in 14.8% in the elderly group, and 83.3% and 9.7%, respectively, in the non-elderly group (p=0.750). Permanent neurological complication was not observed in the elderly group, whereas Vth nerve and VIIIth nerve complications were observed in the non-elderly group. Rates of preoperative multiple comorbidities and of cardiovascular comorbidity were significantly higher in the elderly group (p<0.01). Worsening comorbidity and new pathology at discharge were mainly hypertension in both groups, but glaucoma attack and asthma attack were observed in the elderly group. All pathologies were successfully managed. MVD for elderly patients with TN can be achieved safely with careful perioperative management. Information of comorbidity should be shared with all staff involved in the treatment, who should work as a team to avoid worsening comorbidity. The possibility of unpredictable events in the elderly patients should always be considered. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Hybrid Decompression and Fixation Technique for the Treatment of Multisegmental Cervical Spondylotic Myelopathy

    PubMed Central

    Araos-Silva, Walter; Reyes-Sánchez, Alejandro; Rosales-Olivarez, Luis Miguel; Alpizar-Aguirre, Armando; Melendez, Francisco Lopez

    2016-01-01

    Background Cervical spondilotic myelopathy (CSM) is defined as the compromise of the spinal cord due to degenerative changes of the cervical spine. It is the most common cause of spinal cord dysfunction in patients over 55 years. An early surgical management it is paramount to achieve better neurological outcome. There is still controversy regarding the appropriate surgical treatment for multisegmental CSM involving three or more levels. The hybrid decompression and fixation technique combines one or two level corpectomy and a single level discectomy in order to obtain optimum decompression and fixation in patients with multilevel cervical myelopathy Methods A prospective case-control study was made between 2011 and 2013. A total of 15 patients with diagnosis of CSM received surgical treatment with an anterior hybrid decompression and fixation technique procedure. Inclusion criteria were myelopathy confirmed by radiographic studies, magnetic resonance image (MRI) and electromyography. Results During the 2010-2013 period 15 patients were managed by hybrid decompression and fixation technique. Average age 64.8 years SD9.4. The follow up period was 29.6 SD ± 9.8 months. The JOA score improved significantly to 13.8 +/- 1.9 points at follow-up (paired t test, P = 0.001), Nurick Scale preoperative was 3.3 and improved to 2.4 mean, was significantly (Wilcoxon signed rank test p=0.006) The mean C2-C7 lordosis angle was 10.8° +/- 8.9 before surgery, and 14.3° +/- 8.8 at follow-up, there was no significant loss of lordosis angle between the preoperative and follow-up measurements (Wilcoxon signed rank test, P =0.149); At follow-up, graft non fusion was seen in 1 patient (7%, k=1); Conclusions In this small number, single surgeon, prospective series the use of a single level corpectomy and an adjacent discectomy was shown to provide similar outcomes and complication rates as alternative surgical techniques. The authors thus consider this a viable surgical alternative with

  10. 46 CFR 197.332 - PVHO-Decompression chambers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.332 PVHO—Decompression chambers... dogs, from both sides of a closed hatch; (e) Have interior illumination sufficient to allow visual... the dive, when used for diving operations deeper than 300 fsw, unless a closed bell meeting the...

  11. 46 CFR 197.332 - PVHO-Decompression chambers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.332 PVHO—Decompression chambers... dogs, from both sides of a closed hatch; (e) Have interior illumination sufficient to allow visual... the dive, when used for diving operations deeper than 300 fsw, unless a closed bell meeting the...

  12. 46 CFR 197.332 - PVHO-Decompression chambers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.332 PVHO—Decompression chambers... dogs, from both sides of a closed hatch; (e) Have interior illumination sufficient to allow visual... the dive, when used for diving operations deeper than 300 fsw, unless a closed bell meeting the...

  13. 46 CFR 197.332 - PVHO-Decompression chambers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.332 PVHO—Decompression chambers... dogs, from both sides of a closed hatch; (e) Have interior illumination sufficient to allow visual... the dive, when used for diving operations deeper than 300 fsw, unless a closed bell meeting the...

  14. Endoscopic decompression for intraforaminal and extraforaminal nerve root compression

    PubMed Central

    2011-01-01

    Objective The purpose of this study was to evaluate the outcome of endoscopic decompression surgery for intraforaminal and extraforaminal nerve root compression in the lumbar spine. Methods The records from seventeen consecutive patients treated with endoscopic posterior decompression without fusion for intaforaminal and extraforaminal nerve root compression in the lumbar spine (7 males and 10 females, mean age: 67.9 ± 10.7 years) were retrospectively reviewed. The surgical procedures consisted of lateral or translaminal decompression with or without discectomy. The following items were investigated: 1) the preoperative clinical findings; 2) the radiologic findings including MRI and computed tomography-discography; and 3) the surgical outcome as evaluated using the Japanese Orthopaedic Association scale for lower back pain (JOA score). Results All patients had neurological findings compatible with a radiculopathy, such as muscle weakness and sensory disturbance. MRI demonstrated the obliteration of the normal increased signal intensity fat in the intervertebral foramen. Ten patients out of 14 who underwent computed tomography-discography exhibited disc protrusion or herniation. Selective nerve root block was effective in all patients. During surgery, 12 patients were found to have a protruded disc or herniation that compressed the nerve root. Sixteen patients reported pain relief immediately after surgery. Conclusions Intraforaminal and extraforaminal nerve root compression is a rare but distinct pathological condition causing severe radiculopathy. Endoscopic decompression surgery is considered to be an appropriate and less invasive surgical option. PMID:21439083

  15. A Log Logistic Survival Model Applied to Hypobaric Decompression Sickness

    NASA Technical Reports Server (NTRS)

    Conkin, Johnny

    2001-01-01

    Decompression sickness (DCS) is a complex, multivariable problem. A mathematical description or model of the likelihood of DCS requires a large amount of quality research data, ideas on how to define a decompression dose using physical and physiological variables, and an appropriate analytical approach. It also requires a high-performance computer with specialized software. I have used published DCS data to develop my decompression doses, which are variants of equilibrium expressions for evolved gas plus other explanatory variables. My analytical approach is survival analysis, where the time of DCS occurrence is modeled. My conclusions can be applied to simple hypobaric decompressions - ascents lasting from 5 to 30 minutes - and, after minutes to hours, to denitrogenation (prebreathing). They are also applicable to long or short exposures, and can be used whether the sufferer of DCS is at rest or exercising at altitude. Ultimately I would like my models to be applied to astronauts to reduce the risk of DCS during spacewalks, as well as to future spaceflight crews on the Moon and Mars.

  16. The Design and Development of the Topside Decompression Monitor

    DTIC Science & Technology

    2011-06-01

    4 Subsea Cable CE-3T-6-100UC ................................................... 5 Diver-Worn Depth Sensor ...laptop computer, instrumentation case, diver instrumentation cable, and diver-worn depth sensor ; its software components include a decompression program...1 Sensor Instrumentation Case ................................................................. 1 Diver

  17. Intracranial hypertension in subarachnoid hamorrhage: outcome after decompressive craniectomy.

    PubMed

    Holsgrove, D T; Kitchen, W J; Dulhanty, L; Holland, J P; Patel, H C

    2014-01-01

    Intracranial hypertension can occur following aneurysmal subarachnoid haemorrhage (SAH). It can be treated with decompressive craniectomy (DC) with the aim of reducing intracranial pressure, increasing cerebral perfusion and reducing further morbidity and mortality. We studied the outcome of patients undergoing DC following SAH at our institution, to ascertain whether the use of this treatment can be rationalized.

  18. Decompressive Craniectomy and Traumatic Brain Injury: A Review

    PubMed Central

    Alvis-Miranda, Hernando; Castellar-Leones, Sandra Milena; Moscote-Salazar, Luis Rafael

    2013-01-01

    Intracranial hypertension is the largest cause of death in young patients with severe traumatic brain injury. Decompressive craniectomy is part of the second level measures for the management of increased intracranial pressure refractory to medical management as moderate hypothermia and barbiturate coma. The literature lack of concepts is their indications. We present a review on the state of the art. PMID:27162826

  19. 46 CFR 197.332 - PVHO-Decompression chambers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Each decompression chamber must— (a) Meet the requirements of § 197.328; (b) Have internal dimensions... (m) Have a sound-powered headset or telephone as a backup to the communications system required by § 197.328(c) (5) and (6), except when that communications system is a sound-powered system. ...

  20. Does arthroscopic subacromial decompression improve quality of life.

    PubMed

    Butt, U; Whiteman, A; Wilson, J; Paul, E; Roy, B

    2015-04-01

    There has been a significant rise in the volume of subacromial decompression surgery performed in the UK. This study aimed to determine whether arthroscopic subacromial decompression improves health related quality of life in a cost effective manner. Patients undergoing arthroscopic subacromial decompression surgery for impingement were enrolled between 2012 and 2014. The Oxford shoulder score and the EQ-5D™ instruments were completed prior to and following surgery. A cost-utility analysis was performed. Eighty-three patients were eligible for the study with a mean follow-up duration of 15 months (range: 4-27 months). The mean Oxford shoulder score improved by 13 points (95% confidence interval [CI]: 11-15 points). The mean health utility gain extrapolated from the EQ-5D™ questionnaire improved by 0.23 (95% CI: 0.16-0.30), translating to a minimum cost per QALY of £5,683. Subacromial decompression leads to significant improvement in function and quality of life in a cost effective manner. This provides justification for its ongoing practice by appropriately trained shoulder surgeons in correctly selected patients.

  1. Ethylene oxide sterilization of autologous bone flaps following decompressive craniectomy.

    PubMed

    Missori, P; Polli, F M; Rastelli, E; Baiocchi, P; Artizzu, S; Rocchi, G; Salvati, M; Paolini, S; Delfini, R

    2003-10-01

    In patients undergoing decompressive craniectomy, the bone flap is temporarily preserved either in the subcutaneous tissue of the patient or frozen. However, there are some drawbacks related to these methods. In 16 patients in whom the bone flap was removed for decompressive craniectomy, the bone was firstly washed in hydrogen peroxide and then placed in hermetically-sealed bags and sterilized using ethylene oxide. The bone was repositioned after an average period of 4.3 months. One patient sustained an infection of the surgical wound which required permanent exclusion of the bone flap. In all the others, esthetic and functional results were good after an average follow-up of 20 months. Control CT-scan of the bone flap demonstrated preservation of its structural features with fusion of the bone margins and revitalization of the flap. On MRI a subdural space was again visible. Sterilization of the bone flap with ethylene oxide in patients undergoing decompressive craniectomy avoids some of the drawbacks related to the techniques currently used. The easiness, low cost, good aesthetic and functional results of this procedure make it a valid alternative to other techniques for preservation of autologous bone in decompressive craniectomies.

  2. Decompression-Driven Superconductivity Enhancement in In2 Se3.

    PubMed

    Ke, Feng; Dong, Haini; Chen, Yabin; Zhang, Jianbo; Liu, Cailong; Zhang, Junkai; Gan, Yuan; Han, Yonghao; Chen, Zhiqiang; Gao, Chunxiao; Wen, Jinsheng; Yang, Wenge; Chen, Xiao-Jia; Struzhkin, Viktor V; Mao, Ho-Kwang; Chen, Bin

    2017-09-01

    An unexpected superconductivity enhancement is reported in decompressed In2 Se3 . The onset of superconductivity in In2 Se3 occurs at 41.3 GPa with a critical temperature (Tc ) of 3.7 K, peaking at 47.1 GPa. The striking observation shows that this layered chalcogenide remains superconducting in decompression down to 10.7 GPa. More surprisingly, the highest Tc that occurs at lower decompression pressures is 8.2 K, a twofold increase in the same crystal structure as in compression. It is found that the evolution of Tc is driven by the pressure-induced R-3m to I-43d structural transition and significant softening of phonons and gentle variation of carrier concentration combined in the pressure quench. The novel decompression-induced superconductivity enhancement implies that it is possible to maintain pressure-induced superconductivity at lower or even ambient pressures with better superconducting performance. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Laminoplasty and Laminectomy Hybrid Decompression for the Treatment of Cervical Spondylotic Myelopathy with Hypertrophic Ligamentum Flavum: A Retrospective Study

    PubMed Central

    Ding, Huairong; Xue, Yuan; Tang, Yanming; He, Dong; Li, Zhiyang; Zhao, Ying; Zong, Yaqi; Wang, Yi; Wang, Pei

    2014-01-01

    Objective To report the outcomes of a posterior hybrid decompression protocol for the treatment of cervical spondylotic myelopathy (CSM) associated with hypertrophic ligamentum flavum (HLF). Background Laminoplasty is widely used in patients with CSM; however, for CSM patients with HLF, traditional laminoplasty does not include resection of a pathological ligamentum flavum. Methods This study retrospectively reviewed 116 CSM patients with HLF who underwent hybrid decompression with a minimum of 12 months of follow-up. The procedure consisted of reconstruction of the C4 and C6 laminae using CENTERPIECE plates with spinous process autografts, and resection of the C3, C5, and C7 laminae. Surgical outcomes were assessed using Japanese Orthopedic Association (JOA) score, recovery rate, cervical lordotic angle, cervical range of motion, spinal canal sagittal diameter, bone healing rates on both the hinge and open sides, dural sac expansion at the level of maximum compression, drift-back distance of the spinal cord, and postoperative neck pain assessed by visual analog scale. Results No hardware failure or restenosis was noted. Postoperative JOA score improved significantly, with a mean recovery rate of 65.3±15.5%. Mean cervical lordotic angle had decreased 4.9 degrees by 1 year after surgery (P<0.05). Preservation of cervical range of motion was satisfactory postoperatively. Bone healing rates 6 months after surgery were 100% on the hinge side and 92.2% on the open side. Satisfactory decompression was demonstrated by a significantly increased sagittal canal diameter and cross-sectional area of the dural sac together with a significant drift-back distance of the spinal cord. The dural sac was also adequately expanded at the time of the final follow-up visit. Conclusion Hybrid laminectomy and autograft laminoplasty decompression using Centerpiece plates may facilitate bone healing and produce a comparatively satisfactory prognosis for CSM patients with HLF. PMID:24740151

  4. Extreme Heat

    MedlinePlus

    ... Hurricanes Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Pandemic Power Outages Radiological Dispersion Device Severe Weather Snowstorms & Extreme Cold Space Weather Thunderstorms & Lightning Tornadoes ...

  5. Fluconazole prophylaxis is associated with a decreased rate of coagulase-negative Staphylococcal infections in a subset of extremely low birth weight neonates.

    PubMed

    Abou Jaoude, Roland; Zauk, Adel; Morel, Charlotte; McClure, Diane; Lamacchia, Michael; DeBari, Vincent A

    2014-08-01

    Fluconazole prophylaxis is being used efficaciously in the neonatal intensive care unit (NICU) for fungal prophylaxis in very low birth weight and extremely low birth weight (ELBW) neonates. Little is known about the effect of fluconazole prophylaxis on bacterial infections. The purpose of this study was to examine that issue in a subset of ELBW, those weighing ≤900 g at birth. This is a retrospective study conducted in a level III NICU at state-designated children hospital in New Jersey (USA). We examined the data from our records of neonates ≤ 900 g birth weight during the period March 1, 2007-February 28, 2011. Inclusion in the study was all infants ≤ 900 g before (n = 67) and after (n = 81) the institution of fluconazole prophylaxis. Fluconazole prophylaxis was accompanied by a significant decrease in both the rate and number of days of bacterial infections as well as co-infections. We found that the incidence of coagulase-negative Staphylococcus (CONS) decreased from 46.2 to 24.7 % (OR 2.63; 95 % CI 1.31-5.27). Similarly, days of infection also decreased significantly (p < 0.0001). These data suggest that fluconazole prophylaxis may be associated with a reduction in CONS infections in that subset of ELBW neonates.

  6. Factors associated with tuberculosis cases in Semarang District, Indonesia: case-control study performed in the area where case detection rate was extremely low.

    PubMed

    Rahayu, Sri Ratna; Katsuyama, Hironobu; Demura, Masashi; Katsuyama, Midori; Ota, Yoko; Tanii, Hideji; Higashi, Tomomi; Semadi, Ngakan Putu Djaja; Saijoh, Kiyofumi

    2015-07-01

    Indonesia is ranked as the 4th highest contributor to tuberculosis (TB) in the world. Semarang District in Central Java displays extremely low case detection rate (CDR), possibly contributing to the local prevalence of TB. A case-control study was performed to explore the factors that cause such low CDR. We recruited 129 TB cases and 83 controls that visited the same centers and were not diagnosed with TB. The cases had 7.5 ± 2.3 symptoms/person on average, indicating the delay in diagnosis because the controls only displayed 1.0 ± 1.7. The multiple logistic regression analysis comparing the cases/controls extracted following factors as a risk to have TB: farmer, close contact with TB patients, ignorance of whether Bacillus Calmette-Guérin (BCG) was accepted or no, smoking, low income, a lot of people living in the same room, irregular hand wash before meals, not wash hands after blow, soil floor, and no sunlight and no ventilation in the house. Neither the cases nor the controls knew the symptoms and how to avoid TB infection, which probably caused the delay in diagnosis. It is difficult to change the current living conditions. Thus, the amendment of the community-based education program of TB seems to be required.

  7. Surgical decompression for lumbar stenosis in pediatric achondroplasia.

    PubMed

    Baca, Kirsten E; Abdullah, Madeel A; Ting, Beverlie L; Schkrohowsky, Joshua G; Hoernschemeyer, Daniel G; Carson, Benjamin S; Ain, Michael C

    2010-01-01

    Spinal stenosis is a common complication of achondroplasia. To our knowledge, no study has evaluated a greater than 2-year outcome after surgical intervention for spinal stenosis in such children or compared decompression with and without instrumentation in relation to revision surgery. Our purpose was to assess the efficacy of lumbar decompression and instrumentation for symptomatic stenosis in children with achondroplasia. We retrospectively reviewed our institution's database to identify children (< or =18 y old) with achondroplasia undergoing initial spinal decompression for lumbar stenosis from 1995 through 2003. We identified 18 such patients and reviewed their medical records for demographic data, presenting signs and symptoms, and treatment and outcome data. Mean follow-up was 72.0+/-27.6 months. We determined each patient's symptom score (SS) based on presence of leg weakness, numbness, or pain; abnormal reflexes; incontinence; and walking intolerance (unable to walk > or =5 blocks). Each finding was scored 1 point (6 points maximum). Nine patients requiring revision surgery were assigned a revision postoperative SS. All patients were contacted at the end of data collection and assigned a final follow-up SS. Baseline SS values were compared with postoperative, revision postoperative, and final follow-up scores using a paired t test (alpha=0.05). The mean preoperative and final SS values were significantly different: 4.0+/-0.9 (most common symptoms, leg weakness and incontinence) and 1.6+/-1.7 (most common symptom, leg weakness), respectively. Nine patients underwent decompression with instrumentation initially; 9 did not; 7 of the latter required instrumentation during revision; and 2 of the former also required revision. Those without initial instrumentation were 3.5 times more likely (odds ratio=12.3) to require revision. Surgical decompression with instrumentation significantly reduced the symptoms of lumbar stenosis and the likelihood of revision

  8. Dodecafluoropentane (DDFPe) and decompression sickness-related mortality in rats.

    PubMed

    Sheppard, Ryan L; Regis, David P; Mahon, Richard T

    2015-01-01

    Perfluorocarbon (PFC) formulations can be a useful adjunct treatment for decompression sickness (DCS) when staged decompression procedures cannot be followed due to time constraints or lack of equipment. The benefit of PFC treatment is believed to result from its ability to transport more dissolved gas than can be transported by blood alone. Dodecylfluoropentane (DDFPe) is a unique nanodroplet compound that expands into a gaseous state when exposed to physiological temperatures, resulting in a higher dissolved gas-carrying capacity than standard PFC formulations. We investigated the efficacy of DDFPe in reducing morbidity and mortality in a rat model of severe DCS. Male Sprague-Dawley rats (250-280 g) were compressed to 210 fsw for 60 min before rapid decompression. Animals were immediately injected with 2% DDFPe (0.07 ml · kg(-1), 0.5 ml · kg(-1), 1.0 ml · kg(-1)) or saline, and were transferred to a 100% O2 environment for 30 min. Of the animals in the saline group, 47% (18/38) did not survive the decompression event, while ~98% (46/47) of the animals in the DDFPe group did not survive. Of the animals that died during the observation period, the saline group survived on average 89% longer than DDFPe treated animals. Seizures occurred in 42% of the DDFPe group vs. 16% in the saline group. Histological analysis revealed the presence of large, multifocal gas emboli in the liver and heart of DDFPe treated animals. We conclude that DDFPe is not an effective nonrecompressive treatment for DCS in rodents. Sheppard RL, Regis DP, Mahon RT. Dodecafluoropentane (DDFPe) and decompression sickness-related mortality in rats.

  9. Role of Inflammatory Reponse in Experimental Decompression Sickness

    NASA Technical Reports Server (NTRS)

    Butler, B. D.; Little, T.

    1999-01-01

    Decompression to altitude can result in gas bubble formation both in tissues and in the systemic veins. The venous gas emboli (VGE) are often monitored during decompression exposures to assess risk for decompression sickness (DCS). Astronauts are at risk for DCS during extravehicular activities (EVA), where decompression occurs from the Space Shuttle or Space Station atmospheric pressure of 14.7 pounds per square inch (PSI) to that of the space suit pressure of 4.3 PSI. DCS symptoms include diffuse pain, especially around joints, inflammation and edema. Pathophysiological effects include interstitial inflammatory responses and recurring injury to the vascular endothelium. Such responses can result in vasoconstriction and associated hemodynamic changes.The granulocyte cell activation and chemotaxin release results in the formation of vasoactive and microvascular permeability altering mediators, especially from the lungs which are the principal target organ for the venous bubbles, and from activated cells (neutrophils, platelets, macrophages). Such mediators include free arachidonic acid and the byproducts of its metabolism via the cyclooxygenase and lipoxygenase pathways (see figure). The cyclooxygenase pathway results in formation of prostacyclin and other prostaglandins and thromboxanes that cause vasoconstriction, bronchoconstriction and platelet aggregation. Leukotrienes produced by the alternate pathway cause pulmonary and bronchial smooth muscle contraction and edema. Substances directly affecting vascular tone such as nitric oxide may also play a role in the respose to DCS. We are studying the role and consequent effects of the release inflammatory bioactive mediators as a result of DCS and VGE. More recent efforts are focused on identifying the effects of the body's circadian rhythm on these physiological consequences to decompression stress. al

  10. Valuation of Indonesian catastrophic earthquake bonds with generalized extreme value (GEV) distribution and Cox-Ingersoll-Ross (CIR) interest rate model

    NASA Astrophysics Data System (ADS)

    Gunardi, Setiawan, Ezra Putranda

    2015-12-01

    Indonesia is a country with high risk of earthquake, because of its position in the border of earth's tectonic plate. An earthquake could raise very high amount of damage, loss, and other economic impacts. So, Indonesia needs a mechanism for transferring the risk of earthquake from the government or the (reinsurance) company, as it could collect enough money for implementing the rehabilitation and reconstruction program. One of the mechanisms is by issuing catastrophe bond, `act-of-God bond', or simply CAT bond. A catastrophe bond issued by a special-purpose-vehicle (SPV) company, and then sold to the investor. The revenue from this transaction is joined with the money (premium) from the sponsor company and then invested in other product. If a catastrophe happened before the time-of-maturity, cash flow from the SPV to the investor will discounted or stopped, and the cash flow is paid to the sponsor company to compensate their loss because of this catastrophe event. When we consider the earthquake only, the amount of discounted cash flow could determine based on the earthquake's magnitude. A case study with Indonesian earthquake magnitude data show that the probability of maximum magnitude can model by generalized extreme value (GEV) distribution. In pricing this catastrophe bond, we assumed stochastic interest rate that following the Cox-Ingersoll-Ross (CIR) interest rate model. We develop formulas for pricing three types of catastrophe bond, namely zero coupon bonds, `coupon only at risk' bond, and `principal and coupon at risk' bond. Relationship between price of the catastrophe bond and CIR model's parameter, GEV's parameter, percentage of coupon, and discounted cash flow rule then explained via Monte Carlo simulation.

  11. Valuation of Indonesian catastrophic earthquake bonds with generalized extreme value (GEV) distribution and Cox-Ingersoll-Ross (CIR) interest rate model

    SciTech Connect

    Gunardi,; Setiawan, Ezra Putranda

    2015-12-22

    Indonesia is a country with high risk of earthquake, because of its position in the border of earth’s tectonic plate. An earthquake could raise very high amount of damage, loss, and other economic impacts. So, Indonesia needs a mechanism for transferring the risk of earthquake from the government or the (reinsurance) company, as it could collect enough money for implementing the rehabilitation and reconstruction program. One of the mechanisms is by issuing catastrophe bond, ‘act-of-God bond’, or simply CAT bond. A catastrophe bond issued by a special-purpose-vehicle (SPV) company, and then sold to the investor. The revenue from this transaction is joined with the money (premium) from the sponsor company and then invested in other product. If a catastrophe happened before the time-of-maturity, cash flow from the SPV to the investor will discounted or stopped, and the cash flow is paid to the sponsor company to compensate their loss because of this catastrophe event. When we consider the earthquake only, the amount of discounted cash flow could determine based on the earthquake’s magnitude. A case study with Indonesian earthquake magnitude data show that the probability of maximum magnitude can model by generalized extreme value (GEV) distribution. In pricing this catastrophe bond, we assumed stochastic interest rate that following the Cox-Ingersoll-Ross (CIR) interest rate model. We develop formulas for pricing three types of catastrophe bond, namely zero coupon bonds, ‘coupon only at risk’ bond, and ‘principal and coupon at risk’ bond. Relationship between price of the catastrophe bond and CIR model’s parameter, GEV’s parameter, percentage of coupon, and discounted cash flow rule then explained via Monte Carlo simulation.

  12. The distinguishing effects of low-intensity electromagnetic radiation of different extremely high frequencies on Enterococcus hirae: growth rate inhibition and scanning electron microscopy analysis.

    PubMed

    Hovnanyan, K; Kalantaryan, V; Trchounian, A

    2017-09-01

    A low-intensity electromagnetic field of extremely high frequency has inhibitory and stimulatory effects on bacteria, including Enterococcus hirae. It was shown that the low-intensity (the incident power density of 0·06 mW cm(-2) ) electromagnetic field at the frequencies of 51·8 GHz and 53 GHz inhibited E. hirae ATCC 9790 bacterial growth rate; a stronger effect was observed with 53 GHz, regardless of exposure duration (0·5 h, 1 h or 2 h). Scanning electron microscopy analysis of these effects has been done; the cells were of spherical shape. Electromagnetic field at 53 GHz, but not 51·8 GHz, changed the cell size-the diameter was enlarged 1·3 fold at 53 GHz. These results suggest the difference in mechanisms of action on bacteria for electromagnetic fields at 51·8 GHz and 53 GHz. A stronger inhibitory effect of low-intensity electromagnetic field on Enterococcus hirae ATCC 9790 bacterial growth rate was observed with 53 GHz vs 51·8 GHz, regardless of exposure duration. Scanning electron microscopy analysis showed that almost all irradiated cells in the population have spherical shapes similar to nonirradiated ones, but they have increased diameters in case of irradiated cells at 53 GHz, but not 51·8 GHz. The results are novel, showing distinguishing effects of low-intensity electromagnetic field of different frequencies. They could be applied in treatment of food and different products in medicine and veterinary, where E. hirae plays an important role. © 2017 The Society for Applied Microbiology.

  13. Determination of the minimum infusion rate of propofol required to prevent purposeful movement of the extremities in response to a standardized noxious stimulus in goats.

    PubMed

    Ferreira, Jacques P; Ndawana, Patience S; Dzikiti, Loveness N; Dzikiti, Brighton T

    2016-09-01

    To determine the minimum infusion rate (MIR) of propofol required to prevent purposeful movement in response to a standardized stimulus in goats. Prospective, experimental study. Eight healthy goats (four does, four wethers). Anaesthesia was induced with 4 mg kg(-1) propofol intravenously (IV). A continuous IV infusion of propofol at 0.6 mg kg(-1)  minute(-1) was initiated immediately to maintain anaesthesia. Following endotracheal intubation, goats breathed spontaneously via a circle breathing system delivering supplementary oxygen. The initial propofol infusion rate was maintained for 30 minutes before responses to noxious stimulation provided by clamping the proximal part of the claw with a Vulsellum forceps for 60 seconds were tested. In the presence or absence of purposeful movements of the extremities, the infusion rate was increased or reduced by 0.1 mg kg(-1)  minute(-1) and held constant for 30 minutes before claw clamping was repeated. The propofol MIR for each goat was calculated as the mean of the infusion rates that allowed and abolished movement. Basic cardiopulmonary parameters were monitored, recorded and tested for statistical significance using Wilcoxon's signed rank test with Bonferroni adjustment for multiple testing. The quality of recovery from anaesthesia was assessed and scored. The median MIR of propofol was 0.45 mg kg(-1)  minute(-1) (range: 0.45-0.55 mg kg(-1)  minute(-1) ). Induction and recovery were free of adverse behaviour. No statistically significant cardiopulmonary changes in comparison with baseline were observed, but clinically relevant hypoxaemia at 2 minutes after induction of anaesthesia was consistently observed. Chewing during anaesthesia was observed in three goats. Median times to extubation and standing were 3 minutes (range: 2-6 minutes) and 10 minutes (range: 7-21 minutes), respectively. Propofol induction and maintenance of general anaesthesia minimally compromise cardiopulmonary function when

  14. Surgical decompression for space-occupying cerebral infarction (the Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial [HAMLET]): a multicentre, open, randomised trial.

    PubMed

    Hofmeijer, Jeannette; Kappelle, L Jaap; Algra, Ale; Amelink, G Johan; van Gijn, Jan; van der Worp, H Bart

    2009-04-01

    Patients with space-occupying hemispheric infarctions have a poor prognosis, with case fatality rates of up to 80%. In a pooled analysis of randomised trials, surgical decompression within 48 h of stroke onset reduced case fatality and improved functional outcome; however, the effect of surgery after longer intervals is unknown. The aim of HAMLET was to assess the effect of decompressive surgery within 4 days of the onset of symptoms in patients with space-occupying hemispheric infarction. Patients with space-occupying hemispheric infarction were randomly assigned within 4 days of stroke onset to surgical decompression or best medical treatment. The primary outcome measure was the modified Rankin scale (mRS) score at 1 year, which was dichotomised between good (0-3) and poor (4-6) outcome. Other outcome measures were the dichotomy of mRS score between 4 and 5, case fatality, quality of life, and symptoms of depression. Analysis was by intention to treat. This trial is registered, ISRCTN94237756. Between November, 2002, and October, 2007, 64 patients were included; 32 were randomly assigned to surgical decompression and 32 to best medical treatment. Surgical decompression had no effect on the primary outcome measure (absolute risk reduction [ARR] 0%, 95% CI -21 to 21) but did reduce case fatality (ARR 38%, 15 to 60). In a meta-analysis of patients in DECIMAL (DEcompressive Craniectomy In MALignant middle cerebral artery infarction), DESTINY (DEcompressive Surgery for the Treatment of malignant INfarction of the middle cerebral arterY), and HAMLET who were randomised within 48 h of stroke onset, surgical decompression reduced poor outcome (ARR 16%, -0.1 to 33) and case fatality (ARR 50%, 34 to 66). Surgical decompression reduces case fatality and poor outcome in patients with space-occupying infarctions who are treated within 48 h of stroke onset. There is no evidence that this operation improves functional outcome when it is delayed for up to 96 h after stroke onset

  15. Effect of previous botulinum neurotoxin treatment on microvascular decompression for hemifacial spasm.

    PubMed

    Wang, Xuhui; Thirumala, Parthasarathy D; Shah, Aalap; Gardner, Paul; Habeych, Miguel; Crammond, Donald J; Balzer, Jeffrey; Horowitz, Michael

    2013-03-01

    The objective of this study was to investigate the clinical characteristics, intraoperative findings, complications, and outcomes after the first microvascular decompression (MVD) in patients with and without previous botulinum neurotoxin treatment for hemifacial spasm (HFS). The authors analyzed 246 MVDs performed at the University of Pittsburgh Medical Center between January 1, 2000, and December 31, 2007. One hundred and seventy-six patients with HFS underwent botulinum neurotoxin injection treatment prior to first MVD (Group I), and 70 patients underwent their first MVD without previous botulinum neurotoxin treatment (Group II). Clinical outcome data were obtained immediately after the operation, at discharge, and at follow-up. Follow-up data were collected from 177 patients with a minimum follow-up period of 9 months (mean 54.48 ± 27.84 months). In 246 patients, 89.4% experienced immediate postoperative relief of spasm, 91.1% experienced relief at discharge, and 92.7% experienced relief at follow-up. There was no significant difference in outcomes and complications between Group I and Group II (p > 0.05). Preoperatively, patients in Group I had higher rates of facial weakness, tinnitus, tonus, and platysmal involvement as compared with Group II (p < 0.05). The posterior inferior cerebellar artery and vertebral artery were intraoperatively identified as the offending vessels in cases of vasculature compression in a significantly greater number of patients in Group II compared with Group I (p = 0.008 and p = 0.005, respectively, for each vessel). The lateral spread response (LSR) disappeared in 60.48% of the patients in Group I as compared with 74.19% in Group II (p > 0.05). No significant differences in complications were noted between the 2 groups. Microvascular decompression is an effective and safe procedure for patients with HFS previously treated using botulinum neurotoxin. Intraoperative monitoring with LSR is an effective tool for evaluating adequate

  16. Percutaneous endoscopic transforaminal lumbar spinal canal decompression for lumbar spinal stenosis

    PubMed Central

    Wen, Bingtao; Zhang, Xifeng; Zhang, Lin; Huang, Peng; Zheng, Guoquan

    2016-01-01

    Abstract This study aimed to evaluate the safety and curative effect of percutaneous endoscopic transforaminal lumbar spinal canal decompression in the treatment of lumbar spinal stenosis. This retrospective study recruited 64 patients with lumbar spinal stenosis who underwent percutaneous endoscopic lumbar spinal canal decompression via surgical approach of posterolateral intervertebral foramen. The postoperation neurological function and pain status were evaluated by the visual analog scale (VAS) score of pain and the Oswestry disability index (ODI), and the patient satisfaction was evaluated according to the MacNab outcome criteria. The data, including preoperative comorbidities, operation time, the quantity of bleeding, bed rest time, and intraoperative and postoperative complications, were recorded. The mean operation time was 78 min, the mean quantity of bleeding was 20 mL and bed rest time was 6 h to 3 days. All patients were followed-up for 4 months to 5 years. The mean preoperative VAS score was 7.7 ± 1.2, while postoperative 3 months, 6 months, and final follow-up VAS scores were 2.8 ± 0.7, 2.1 ± 0.6, and 0.8 ± 0.6, respectively (P < 0.001). The mean preoperative ODI score was 72.4 ± 1.2, while postoperative 3 months, 6 months, and final follow-up ODI scores were 29.7 ± 4.9, 23.9 ± 4.0, and 12.5 ± 3.9, respectively (P < 0.001). The excellent and good rate reached 73.4% at the final follow-up. The percutaneous endoscopic transforaminal lumbar spinal canal decompression is an easy, safe, and effective minimally invasive surgery for patients with lumbar spinal stenosis. PMID:27977571

  17. Trigemino-cardiac reflex during microvascular trigeminal decompression in cases of trigeminal neuralgia.

    PubMed

    Schaller, Bernhard

    2005-01-01

    The trigemino-cardiac reflex (TCR) is a well-recognized phenomenon consisting of bradycardia, arterial hypotension, apnea, and gastric hypermotility during ocular surgery or other manipulations in and around the orbit. Thus far, it could bee shown that central stimulation of the trigeminal nerve during transsphenoidal surgery and surgery for tumors in the cerebellopontine angle can lead to TCR. In cases of microvascular trigeminal decompression for trigeminal neuralgia, no data of the possible occurrence of TCR are available. TCR was defined as a drop in mean arterial blood pressure (MABP) and the heart rate (HR) of more than 20% to the baseline values before the stimulus and coinciding with the manipulation of the trigeminal nerve. Electronic anesthetic recorded perioperative HR and MABP values were reviewed retrospectively in 28 patients who received microvascular trigeminal decompression in cases of trigeminal neuralgia and were divided into two subgroups on the basis of occurrence of TCR during surgery. Of the 28 patients, 5 (18%) showed evidence of TCR during manipulation at the trigeminal radix by separation from microvascular structures. Their HR fell 46% and their MABP 57% during operative procedures near the trigeminal nerve as compared with levels immediately before the stimulus. After cessation of manipulation, HR and MABP returned (spontaneously) to levels before the stimulus. Risk factors of TCR were compared with results from the literature. In conclusion, the present results give evidence of TCR during manipulation of the central part of the trigeminal nerve during microvascular trigeminal decompression in cases of trigeminal neuralgia under a standardized anesthetic protocol.

  18. A minimally invasive technique for decompression of Chiari malformation type I (DECMI study): study protocol for a randomised controlled trial

    PubMed Central

    Hu, Yu; Liu, Jiagang; Chen, Haifeng; Jiang, Shu; Li, Qiang; Fang, Yuan; Gong, Shuhui; Wang, Yuelong; Huang, Siqing

    2015-01-01

    Introduction Chiari malformation type I (CM-I) is a congenital hindbrain anomaly that requires surgical decompression in symptomatic patients. Posterior fossa decompression with duraplasty (PFDD) has been widely practiced in Chiari decompression, but dural opening carries a high risk of surgical complications. A minimally invasive technique, dural splitting decompression (DSD), preserves the inner layer of the dura without dural opening and duraplasty, potentially reducing surgical complications, length of operative time and hospital stay, and cost. If DSD is non-inferior to PFDD in terms of clinical improvement, DSD could be an alternative treatment modality for CM-I. So far, no randomised study of surgical treatment of CM-I has been reported. This study aims to evaluate if DSD is an effective, safe and cost-saving treatment modality for adult CM-I patients, and may provide evidence for using the minimally invasive procedure extensively. Methods and analysis DECMI is a randomised controlled, single-masked, non-inferiority, single centre clinical trial. Participants meeting the criteria will be randomised to the DSD group and the PFDD group in a 1:1 ratio. The primary outcome is the rate of clinical improvement, which is defined as the complete resolution or partial improvement of the presenting symptoms/signs. The secondary outcomes consist of the incidence of syrinx reduction, postoperative morbidity rates, reoperation rate, quality of life (QoL) and healthcare resource utilisation. A total of 160 patients will be included and followed up at 3 and 12 months postoperatively. Ethics and dissemination The study protocol was approved by the Biological and Medical Ethics Committee of West China Hospital. The findings of this trial will be published in a peer-reviewed scientific journal and presented at scientific conferences. Trial registration number ChiCTR-TRC-14004099. PMID:25926152

  19. A deep stop during decompression from 82 fsw (25 m) significantly reduces bubbles and fast tissue gas tensions.

    PubMed

    Marroni, A; Bennett, P B; Cronje, F J; Cali-Corleo, R; Germonpre, P; Pieri, M; Bonuccelli, C; Balestra, C

    2004-01-01

    In spite of many modifications to decompression algorithms, the incidence of decompression sickness (DCS) in scuba divers has changed very little. The success of stage, compared to linear ascents, is well described yet theoretical changes in decompression ratios have diminished the importance of fast tissue gas tensions as critical for bubble generation. The most serious signs and symptoms of DCS involve the spinal cord, with a tissue half time of only 12.5 minutes. It is proposed that present decompression schedules do not permit sufficient gas elimination from such fast tissues, resulting in bubble formation. Further, it is hypothesized that introduction of a deep stop will significantly reduce fast tissue bubble formation and neurological DCS risk. A total of 181 dives were made to 82 fsw (25 m) by 22 volunteers. Two dives of 25 min and 20 min were made, with a 3 hr 30 min surface interval and according to 8 different ascent protocols. Ascent rates of 10, 33 or 60 fsw/min (3, 10, 18 m/min) were combined with no stops or a shallow stop at 20 fsw (6 m) or a deep stop at 50 fsw (15 m) and a shallow at 20 fsw (6 m). The highest bubbles scores (8.78/9.97), using the Spencer Scale (SS) and Extended Spencer Scale (ESS) respectively, were with the slowest ascent rate. This also showed the highest 5 min and 10 min tissue loads of 48% and 75%. The lowest bubble scores (1.79/2.50) were with an ascent rate of 33 fsw (10 m/min) and stops for 5 min at 50 fsw (15 m) and 20 fsw (6 m). This also showed the lowest 5 and 10 min tissue loads at 25% and 52% respectively. Thus, introduction of a deep stop significantly reduced Doppler detected bubbles together with tissue gas tensions in the 5 and 10 min tissues, which has implications for reducing the incidence of neurological DCS in divers.

  20. [A method for evaluating the safety of decompression regimens for divers].

    PubMed

    Volkov, L K; Voĭtsekhovich, I A; Liapin, V M; Miasnikov, A A

    1996-09-01

    The authors offer a way of estimation of safety modes of decompression, based on definition of intensity of venous gas embolism (VGE) at each decompression and account of probability of illness of divers in series of tests. Intensity of VGE was determined with the help of ultrasonic gas bubbles Doppler radar. Comparative safety of standard modes of decompression of divers of the Navy was estimated, and also the modes, designed in accordance with mathematical model of decompression, offered by I. A. Voĭtsekhovich (1990), were done. The results testify, that use of ultrasonic radar for estimation of intensity of VGE at decompression and account of average and maximum probability of decompression illness in series of tests of modes permit to receive the comparative characteristic of safety of modes at small number of decompressions.

  1. The effect of rapid and sustained decompression on barotrauma in juvenile brook lamprey and Pacific lamprey: implications for passage at hydroelectric facilities

    SciTech Connect

    Colotelo, Alison HA; Pflugrath, Brett D.; Brown, Richard S.; Brauner, Colin J.; Mueller, Robert P.; Carlson, Thomas J.; Deng, Zhiqun; Ahmann, Martin L.; Trumbo, Bradly A.

    2012-10-01

    Fish passing downstream through hydroelectric facilities may pass through hydroturbines where they experience a rapid decrease in barometric pressure as they pass by turbine blades, which can lead to barotraumas including swim bladder rupture, exopthalmia, emboli, and hemorrhaging. In juvenile Chinook salmon, the main mechanism for injury is thought to be expansion of existing gases (particularly those present in the swim bladder) and the rupture of the swim bladder ultimately leading to exopthalmia, emboli and hemorrhaging. In fish that lack a swim bladder, such as lamprey, the rate and severity of barotraumas due to rapid decompression may be reduced however; this has yet to be extensively studied. Another mechanism for barotrauma can be gases coming out of solution and the rate of this occurrence may vary among species. In this study, juvenile brook and Pacific lamprey acclimated to 146.2 kPa (equivalent to a depth of 4.6 m) were subjected to rapid (<1 sec; brook lamprey only) or sustained decompression (17 minutes) to a very low pressure (13.8 kPa) using a protocol previously applied to juvenile Chinook salmon. No mortality or evidence of barotraumas, as indicated by the presence of hemorrhages, emboli or exopthalmia, were observed during rapid or sustained decompression, nor following recovery for up to 120 h following sustained decompression. In contrast, mortality or injury would be expected for 97.5% of juvenile Chinook salmon exposed to a similar rapid decompression to these very low pressures. Additionally, juvenile Chinook salmon experiencing sustained decompression died within 7 minutes, accompanied by emboli in the fins and gills and hemorrhaging in the tissues. Thus, juvenile lamprey may not be susceptible to barotraumas associated with hydroturbine passage to the same degree as juvenile salmonids, and management of these species should be tailored to their specific morphological and physiological characteristics.

  2. Variability of rRNA Operon Copy Number and Growth Rate Dynamics of Bacillus Isolated from an Extremely Oligotrophic Aquatic Ecosystem.

    PubMed

    Valdivia-Anistro, Jorge A; Eguiarte-Fruns, Luis E; Delgado-Sapién, Gabriela; Márquez-Zacarías, Pedro; Gasca-Pineda, Jaime; Learned, Jennifer; Elser, James J; Olmedo-Alvarez, Gabriela; Souza, Valeria

    2015-01-01

    The ribosomal RNA (rrn) operon is a key suite of genes related to the production of protein synthesis machinery and thus to bacterial growth physiology. Experimental evidence has suggested an intrinsic relationship between the number of copies of this operon and environmental resource availability, especially the availability of phosphorus (P), because bacteria that live in oligotrophic ecosystems usually have few rrn operons and a slow growth rate. The Cuatro Ciénegas Basin (CCB) is a complex aquatic ecosystem that contains an unusually high microbial diversity that is able to persist under highly oligotrophic conditions. These environmental conditions impose a variety of strong selective pressures that shape the genome dynamics of their inhabitants. The genus Bacillus is one of the most abundant cultivable bacterial groups in the CCB and usually possesses a relatively large number of rrn operon copies (6-15 copies). The main goal of this study was to analyze the variation in the number of rrn operon copies of Bacillus in the CCB and to assess their growth-related properties as well as their stoichiometric balance (N and P content). We defined 18 phylogenetic groups within the Bacilli clade and documented a range of from six to 14 copies of the rrn operon. The growth dynamic of these Bacilli was heterogeneous and did not show a direct relation to the number of operon copies. Physiologically, our results were not consistent with the Growth Rate Hypothesis, since the copies of the rrn operon were decoupled from growth rate. However, we speculate that the diversity of the growth properties of these Bacilli as well as the low P content of their cells in an ample range of rrn copy number is an adaptive response to oligotrophy of the CCB and could represent an ecological mechanism that allows these taxa to coexist. These findings increase the knowledge of the variability in the number of copies of the rrn operon in the genus Bacillus and give insights about the

  3. Variability of rRNA Operon Copy Number and Growth Rate Dynamics of Bacillus Isolated from an Extremely Oligotrophic Aquatic Ecosystem

    PubMed Central

    Valdivia-Anistro, Jorge A.; Eguiarte-Fruns, Luis E.; Delgado-Sapién, Gabriela; Márquez-Zacarías, Pedro; Gasca-Pineda, Jaime; Learned, Jennifer; Elser, James J.; Olmedo-Alvarez, Gabriela; Souza, Valeria

    2016-01-01

    The ribosomal RNA (rrn) operon is a key suite of genes related to the production of protein synthesis machinery and thus to bacterial growth physiology. Experimental evidence has suggested an intrinsic relationship between the number of copies of this operon and environmental resource availability, especially the availability of phosphorus (P), because bacteria that live in oligotrophic ecosystems usually have few rrn operons and a slow growth rate. The Cuatro Ciénegas Basin (CCB) is a complex aquatic ecosystem that contains an unusually high microbial diversity that is able to persist under highly oligotrophic conditions. These environmental conditions impose a variety of strong selective pressures that shape the genome dynamics of their inhabitants. The genus Bacillus is one of the most abundant cultivable bacterial groups in the CCB and usually possesses a relatively large number of rrn operon copies (6–15 copies). The main goal of this study was to analyze the variation in the number of rrn operon copies of Bacillus in the CCB and to assess their growth-related properties as well as their stoichiometric balance (N and P content). We defined 18 phylogenetic groups within the Bacilli clade and documented a range of from six to 14 copies of the rrn operon. The growth dynamic of these Bacilli was heterogeneous and did not show a direct relation to the number of operon copies. Physiologically, our results were not consistent with the Growth Rate Hypothesis, since the copies of the rrn operon were decoupled from growth rate. However, we speculate that the diversity of the growth properties of these Bacilli as well as the low P content of their cells in an ample range of rrn copy number is an adaptive response to oligotrophy of the CCB and could represent an ecological mechanism that allows these taxa to coexist. These findings increase the knowledge of the variability in the number of copies of the rrn operon in the genus Bacillus and give insights about the

  4. Dynamics of upper mantle rocks decompression melting above hot spots under continental plates

    NASA Astrophysics Data System (ADS)

    Perepechko, Yury; Sorokin, Konstantin; Sharapov, Victor

    2014-05-01

    Numeric 2D simulation of the decompression melting above the hot spots (HS) was accomplished under the following conditions: initial temperature within crust mantle section was postulated; thickness of the metasomatized lithospheric mantle is determined by the mantle rheology and position of upper asthenosphere boundary; upper and lower boundaries were postulated to be not permeable and the condition for adhesion and the distribution of temperature (1400-2050°C); lateral boundaries imitated infinity of layer. Sizes and distribution of lateral points, their symmetry, and maximum temperature varied between the thermodynamic condition for existences of perovskite - majorite transition and its excess above transition temperature. Problem was solved numerically a cell-vertex finite volume method for thermo hydrodynamic problems. For increasing convergence of iterative process the method of lower relaxation with different value of relaxation parameter for each equation was used. The method of through calculation was used for the increase in the computing rate for the two-layered upper mantle - lithosphere system. Calculated region was selected as 700 x (2100-4900) km. The time step for the study of the asthenosphere dynamics composed 0.15-0.65 Ma. The following factors controlling the sizes and melting degree of the convective upper mantle, are shown: a) the initial temperature distribution along the section of upper mantleb) sizes and the symmetry of HS, c) temperature excess within the HS above the temperature on the upper and lower mantle border TB=1500-2000oC with 5-15% deviation but not exceed 2350oC. It is found, that appearance of decompression melting with HS presence initiate primitive mantle melting at TB > of 1600oC. Initial upper mantle heating influence on asthenolens dimensions with a constant HS size is controlled mainly by decompression melting degree. Thus, with lateral sizes of HS = 400 km the decompression melting appears at TB > 1600oC and HS

  5. Risk of decompression sickness in the presence of circulating microbubbles

    NASA Technical Reports Server (NTRS)

    Kumar, K. Vasantha; Powell, Michael R.

    1993-01-01

    In this study, we examined the association between microbubbles formed in the circulation from a free gas phase and symptoms of altitude decompression sickness (DCS). In a subgroup of 59 males of mean (S.D) age 31.2 (5.8) years who developed microbubbles during exposure to 26.59 kPa (4.3 psi) under simulated extravehicular activities (EVA), symptoms of DCS occurred in 24 (41 percent) individuals. Spencer grade 1 microbubbles occurred in 4 (7 percent), grade 2 in 9 (15 percent), grade 3 in 15 (25 percent), and grade 4 in 31 (53 percent) of subjects. Survival analysis using Cox proportional hazards regression showed that individuals with less than grade 3 CMB showed 2.46 times (95 percent confidence interval = 1.26 to 5.34) higher risk of symptoms. This information is crucial for defining the risk of DCS for inflight Doppler monitoring under space EVA. Altitude decompression sickness (DCS) occurs when there is acute reduction in ambient pressure. The symptoms of DCS are due to the formation of a free gas phase (in the form of gas microbubbles) in tissues during decompression. Musculo-skeletal pain of bends is the commonest form of DCS in altitude exposures. In the space flight environment, there is a risk of DCS when astronauts decompress from the normobaric shuttle pressure into the hypobaric space suit pressure (currently about 29.65 kPa (4.3 psi) for extra-vehicular activities (EVA). This risk is counterbalanced by a judicious combination of prior denitrogenation and staged decompression. Studies of DCS are limited by the duration of the test at reduced pressure. Since only a proportion of subjects tested develop symptoms, the information on DCS is generally incomplete or 'censored'. Many studies employ Doppler ultrasound monitoring of the precordial area for detecting circulating microbubbles (CMB). Although the association between CMB and bends pain is not causal, CMB are frequently monitored during decompression. In this paper, we examine the association

  6. Clinical study of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability.

    PubMed

    Guo, Shuguang; Sun, Junying; Tang, Genlin

    2013-03-01

    The aim of this study was to observe the clinical effects of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability. The 48 patients comprised 27 males and 21 females, aged 47-72 years. Three cases had first and second degree lumbar spondylolisthesis and all received bilateral vertebral lamina fenestration for posterior lumbar interbody fusion (PLIF) using a threaded fusion cage (TFC), which maintains the three-column spinal stability. Attention was given to ensure the correct pre-operative fenestration, complete decompression and the prevention of adhesions. After an average follow-up of 26.4 months, the one year post-operative X-ray radiographs suggested that the successful fusion rate was 88.1%, and this was 100% in the two-year post-operative radiographs. Moreover, the functional recovery rate was 97.9%. Bilateral vertebral lamina fenestration for lumbar interbody fusion is an ideal surgical method for the treatment of lower lumbar instability. The surgical method retains the spinal posterior column and middle column and results in full decompression and reliable fusion by a limited yet effective surgical approach.

  7. Clinical study of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability

    PubMed Central

    GUO, SHUGUANG; SUN, JUNYING; TANG, GENLIN

    2013-01-01

    The aim of this study was to observe the clinical effects of bilateral decompression via vertebral lamina fenestration for lumbar interbody fusion in the treatment of lower lumbar instability. The 48 patients comprised 27 males and 21 females, aged 47–72 years. Three cases had first and second degree lumbar spondylolisthesis and all received bilateral vertebral lamina fenestration for posterior lumbar interbody fusion (PLIF) using a threaded fusion cage (TFC), which maintains the three-column spinal stability. Attention was given to ensure the correct pre-operative fenestration, complete decompression and the prevention of adhesions. After an average follow-up of 26.4 months, the one year post-operative X-ray radiographs suggested that the successful fusion rate was 88.1%, and this was 100% in the two-year post-operative radiographs. Moreover, the functional recovery rate was 97.9%. Bilateral vertebral lamina fenestration for lumbar interbody fusion is an ideal surgical method for the treatment of lower lumbar instability. The surgical method retains the spinal posterior column and middle column and results in full decompression and reliable fusion by a limited yet effective surgical approach. PMID:23407794

  8. Percutaneous Laser Disc Decompression (PLDD): Experience and Results From Multiple Centers and 19,880 Procedures

    NASA Astrophysics Data System (ADS)

    Paolo Tassi, Gian; Choy, Daniel S. J.; Hellinger, Johannes; Hellinger, Stefan; Lee, Sang-Ho

    2010-05-01

    In mid-February 1986, Peter Ascher and Daniel Choy performed the first Percutaneous Laser Disc Decompression (PLDD) at the Neurosurgical Department, University of Graz, Graz, Austria. It was planned to deliver 1000 joules with a Nd:YAG laser to a herniated L4-5 disc causing sciatica. At 600 joules the procedure was terminated because the pain was gone. Since then, PLDD has spread all over the world, with procedures being performed in the entire spine except for T1-T4 because these discs do not permit percutaneous access with a needle. The success rate has ranged from 70 to 89%, and the complication rate, chiefly discitis, from 0.3 to 1.0%. When successful, return to normal work averages one week. Long term follow-up to 23 years yields a recurrence rate of 4-5%.

  9. Do nerve conduction studies predict the outcome of carpal tunnel decompression?

    PubMed

    Bland, J D

    2001-07-01

    Patients (n = 3336) who had been tested for suspected carpal tunnel syndrome (CTS) were contacted by postal questionnaire and their opinions sought of the overall subjective outcome of any treatments using a five-point rating scale. Operative results were compared with preoperative nerve conduction, clinical and demographic variables, and a multiple logistic regression analysis used to identify significant prognostic factors. Among 1268 surgical procedures that were identified, the overall surgical success rate was 69%. Preoperative nerve conduction study findings, greater age, lower symptom scores, longer disease duration, and male gender were significant predictors of poor outcome. Nerve conduction studies had the strongest effect, with patients with middle-grade abnormalities having better results than those with either very severe or no abnormality. Surgical carpal tunnel decompression has a significant failure rate. The preoperative nerve conduction studies account for a proportion of the total variation in outcome. Copyright 2001 John Wiley & Sons, Inc. Muscle Nerve 24: 935-940, 2001

  10. Fluoxetine Protection in Decompression Sickness in Mice is Enhanced by Blocking TREK-1 Potassium Channel with the "spadin" Antidepressant.

    PubMed

    Vallée, Nicolas; Lambrechts, Kate; De Maistre, Sébastien; Royal, Perrine; Mazella, Jean; Borsotto, Marc; Heurteaux, Catherine; Abraini, Jacques; Risso, Jean-Jacques; Blatteau, Jean-Eric

    2016-01-01

    In mice, disseminated coagulation, inflammation, and ischemia induce neurological damage that can lead to death. These symptoms result from circulating bubbles generated by a pathogenic decompression. Acute fluoxetine treatment or the presence of the TREK-1 potassium channel increases the survival rate when mice are subjected to an experimental dive/decompression protocol. This is a paradox because fluoxetine is a blocker of TREK-1 channels. First, we studied the effects of an acute dose of fluoxetine (50 mg/kg) in wild-type (WT) and TREK-1 deficient mice (knockout homozygous KO and heterozygous HET). Then, we combined the same fluoxetine treatment with a 5-day treatment protocol with spadin, in order to specifically block TREK-1 activity (KO-like mice). KO and KO-like mice were regarded as antidepressed models. In total, 167 mice (45 WTcont 46 WTflux 30 HETflux and 46 KOflux) constituting the flux-pool and 113 supplementary mice (27 KO-like 24 WTflux2 24 KO-likeflux 21 WTcont2 17 WTno dive) constituting the spad-pool were included in this study. Only 7% of KO-TREK-1 treated with fluoxetine (KOflux) and 4% of mice treated with both spadin and fluoxetine (KO-likeflux) died from decompression sickness (DCS) symptoms. These values are much lower than those of WT control (62%) or KO-like mice (41%). After the decompression protocol, mice showed significant consumption of their circulating platelets and leukocytes. Spadin antidepressed mice were more likely to exhibit DCS. Nevertheless, mice which had both blocked TREK-1 channels and fluoxetine treatment were better protected against DCS. We conclude that the protective effect of such an acute dose of fluoxetine is enhanced when TREK-1 is inhibited. We confirmed that antidepressed models may have worse DCS outcomes, but concomitant fluoxetine treatment not only decreased DCS severity but increased the survival rate.

  11. Predictive modeling of altitude decompression sickness in humans

    NASA Technical Reports Server (NTRS)

    Kenyon, D. J.; Hamilton, R. W., Jr.; Colley, I. A.; Schreiner, H. R.

    1972-01-01

    The coding of data on 2,565 individual human altitude chamber tests is reported as part of a selection procedure designed to eliminate individuals who are highly susceptible to decompression sickness, individual aircrew members were exposed to the pressure equivalent of 37,000 feet and observed for one hour. Many entries refer to subjects who have been tested two or three times. This data contains a substantial body of statistical information important to the understanding of the mechanisms of altitude decompression sickness and for the computation of improved high altitude operating procedures. Appropriate computer formats and encoding procedures were developed and all 2,565 entries have been converted to these formats and stored on magnetic tape. A gas loading file was produced.

  12. Prevention of decompression sickness during a simulated space docking mission.

    PubMed

    Cooke, J P; Bollinger, R R; Richardson, B

    1975-07-01

    This study has shown that repetitive exchanges between the American Apollo space vehicle atmosphere of 100% oxygen at 5 psia (258 torr) and the Russian Soyuz spacecraft atmosphere of 30% oxygen-70% nitrogen at 10 psia (523 torr), as simulated in altitude chambers, will not likely result in any form of decompression sickness. This conclusion is based upon the absence of any form of bends in seven crewmen who participated in 11 tests distributed over three 24-h periods. During each period, three transfers from the 5 to the 10 psia environments were performed by simulating passage through a docking module which served as an airlock where astronauts and cosmonauts first adapted to each other's cabin gases and pressures before transfer. Biochemical tests, subjective fatigue scores, and the complete absence of any form of pain were also indicative that decompression sickness should not be expected if this spacecraft transfer schedule is followed.

  13. Report on computation of repetitive hyperbaric-hypobaric decompression tables

    NASA Technical Reports Server (NTRS)

    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.

  14. Bayesian approach to decompression sickness model parameter estimation.

    PubMed

    Howle, L E; Weber, P W; Nichols, J M

    2017-03-01

    We examine both maximum likelihood and Bayesian approaches for estimating probabilistic decompression sickness model parameters. Maximum likelihood estimation treats parameters as fixed values and determines the best estimate through repeated trials, whereas the Bayesian approach treats parameters as random variables and determines the parameter probability distributions. We would ultimately like to know the probability that a parameter lies in a certain range rather than simply make statements about the repeatability of our estimator. Although both represent powerful methods of inference, for models with complex or multi-peaked likelihoods, maximum likelihood parameter estimates can prove more difficult to interpret than the estimates of the parameter distributions provided by the Bayesian approach. For models of decompression sickness, we show that while these two estimation methods are complementary, the credible intervals generated by the Bayesian approach are more naturally suited to quantifying uncertainty in the model parameters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Denitrogenation interruptions with air. [resulting in decompression sickness

    NASA Technical Reports Server (NTRS)

    Cooke, J. P.

    1976-01-01

    A 3-h denitrogenation period at ground-level pressure with 95% O2-5% N2, with an air interruption of 5 min or more and matched with additional denitrogenation time equal to the interruption, will later result occasionally in altitude decompression sickness ('bends') during a 2-h decompression exposure at 3.8 psia (10,058 m equivalent) with 92% O2- 8% N2. Thus the equal time or 'mirror-image' make-up time for loss of denitrogenation did not prevent bends 7 times in 17 subjects during 71 exposures with air interruptions; on the other hand, no case of bends was reported after uninterrupted denitrogenation periods. Nitrogen-loading during the interruptive period is believed to resupply the bends sites with additional nitrogen, which re-establishes conditions favoring a return to a high incidence of bends.

  16. Prevention of decompression sickness during a simulated space docking mission

    NASA Technical Reports Server (NTRS)

    Cooke, J. P.; Bollinger, R. R.; Richardson, B.

    1975-01-01

    This study has shown that repetitive exchanges between the Apollo space vehicle atmosphere of 100% oxygen at 5 psia (258 torr) and the Soyuz spacecraft atmosphere of 30% oxygen-70% nitrogen at 10 psia (533 torr), as simulated in altitude chambers, will not likely result in any form of decompression sickness. This conclusion is based upon the absence of any form of bends in seven crewmen who participated in 11 tests distributed over three 24-h periods. During each period, three transfers from the 5 to the 10 psia environments were performed by simulating passage through a docking module which served as an airlock where astronauts and cosmonauts first adapted to each other's cabin gases and pressures before transfer. Biochemical tests, subjective fatigue scores, and the complete absence of any form of pain were also indicative that decompression sickness should not be expected if this spacecraft transfer schedule is followed.

  17. Acute obstructive hydrocephalus complicating decompression surgery of the craniovertebral junction

    PubMed Central

    Ohya, Junichi; Chikuda, Hirotaka; Nakatomi, Hirofumi; Sakamoto, Ryuji; Saito, Nobuhito; Tanaka, Sakae

    2016-01-01

    Obstructive hydrocephalus has been described as a rare complication following foramen magnum decompression for Chiari malformation. However, there are few reports of obstructive hydrocephalus after spinal surgery for other pathologies of the craniovertebral junction (CVJ). The authors herein report a 52-year-old female with achondroplasia presenting with an 8-month history of myelopathy due to spinal cord compression at CVJ. She underwent resection of the C1 posterior arch and part of the edge of the occipital bone. A computed tomography (CT) scan obtained 1-week after the surgery revealed bilateral infratentorial fluid collection. The patient was first managed conservatively; however, on the 17th day, her consciousness level showed sudden deterioration. Emergency CT demonstrated marked hydrocephalus due to obstruction of the cerebral aqueduct. Acute obstructive hydrocephalus can occur late after decompression surgery at the CVJ, and thus should be included in the differential diagnosis of a deteriorating mental status. PMID:27366268

  18. Change of Lumbar Ligamentum Flavum after Indirect Decompression Using Anterior Lumbar Interbody Fusion

    PubMed Central

    Orita, Sumihisa; Yamauchi, Kazuyo; Eguchi, Yawara; Aoki, Yasuchika; Nakamura, Junichi; Miyagi, Masayuki; Suzuki, Miyako; Kubota, Gou; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Shiga, Yasuhiro; Abe, Koki; Kanamoto, Hiroto; Inoue, Gen; Takahashi, Kazuhisa; Furuya, Takeo; Koda, Masao

    2017-01-01

    Study Design Retrospective case series. Purpose The purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up. Overview of Literature Extreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported. Methods We evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1–2 to L5–S1 was calculated using a Picture Archiving and Communication System. Results Spinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1–2 to L5–S1 were 150 mm2 and 78 mm2, respectively. The average CSA of the ligamentum flavum at L4–5 (30 mm2) (fusion level) was significantly less than that at L1–2 to L3–4 or L5–S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4–5 was significantly larger than at the other levels. Conclusions Spinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery. PMID:28243378

  19. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery.

    PubMed

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-12-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as "resection at an anterior site of the spinal cord from a posterior approach" (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis.

  20. Resection of Beak-Type Thoracic Ossification of the Posterior Longitudinal Ligament from a Posterior Approach under Intraoperative Neurophysiological Monitoring for Paralysis after Posterior Decompression and Fusion Surgery

    PubMed Central

    Imagama, Shiro; Ando, Kei; Ito, Zenya; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Ishikawa, Yoshimoto; Tsushima, Mikito; Matsumoto, Akiyuki; Tanaka, Satoshi; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Nakashima, Hiroaki; Wakao, Norimitsu; Nishida, Yoshihiro; Matsuyama, Yukihiro; Ishiguro, Naoki

    2016-01-01

    Study Design Prospective clinical study. Objective Posterior decompression and fusion surgery for beak-type thoracic ossification of the posterior longitudinal ligament (T-OPLL) generally has a favorable outcome. However, some patients require additional surgery for postoperative severe paralysis, a condition that is inadequately discussed in the literature. The objective of this study was to describe the efficacy of a procedure we refer to as “resection at an anterior site of the spinal cord from a posterior approach” (RASPA) for severely paralyzed patients after posterior decompression and fusion surgery for beak-type T-OPLL. Methods Among 58 consecutive patients who underwent posterior decompression and fusion surgery for beak-type T-OPLL since 1999, 3 with postoperative paralysis (5%) underwent RASPA in our institute. Clinical records, the Japanese Orthopaedic Association score, gait status, intraoperative neurophysiological monitoring (IONM) findings, and complications were evaluated in these cases. Results All three patients experienced a postoperative decline in Manual Muscle Test (MMT) scores of 0 to 2 after the first surgery. RASPA was performed 3 weeks after the first surgery. All patients showed gradual improvements in MMT scores for the lower extremity and in ambulatory status; all could walk with a cane at an average of 4 months following RASPA surgery. There were no postoperative complications. Conclusions RASPA surgery for beak-type T-OPLL after posterior decompression and fusion surgery resulted in good functional outcomes as a salvage surgery for patients with severe paralysis. Advantages of RASPA include a wide working space, no spinal cord retraction, and additional decompression at levels without T-OPLL resection and spinal cord shortening after additional dekyphosis and compression maneuvers. When used with IONM, this procedure may help avoid permanent postoperative paralysis. PMID:27853667

  1. Towards Probablistic Assessment of Hypobaric Decompression Sickness Treatment

    NASA Technical Reports Server (NTRS)

    Conkin, J.; Abercromby, A. F.; Feiveson, A. H.; Gernhardt, M. L.; Norcross, J. R.; Ploutz-Snyder, R.; Wessel, J. H., III

    2013-01-01

    INTRODUCTION: Pressure, oxygen (O2), and time are the pillars to effective treatment of decompression sickness (DCS). The NASA DCS Treatment Model links a decrease in computed bubble volume to the resolution of a symptom. The decrease in volume is realized in two stages: a) during the Boyle's Law compression and b) during subsequent dissolution of the gas phase by the O2 window. METHODS: The cumulative distribution of 154 symptoms that resolved during repressurization was described wit