51 research outputs found

    Massive Deposition and Accumulation of Hydroxyapatite Crystal after Total Hip Arthroplasty: A Case Report

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    We presented a case in which massive hydroxyapatite accumulation was observed around the artificial hip joint. A 66-year-old female showed a massive accumulation of fluid in and around the hip joint, and milk-like aspirate was obtained. Her aspirate culture was negative, and sediment analysis by X-ray diffraction showed that its component was hydroxyapatite. Since pain was mild, the patient was treated conservatively. To our knowledge, this is the first case in which liquid hydroxyapatite (milk of calcium) was accumulated around the artificial hip joint

    Verification of diesel spray ignition phenomenon in dual-fuel diesel-piloted premixed natural gas engine

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    [EN] Dual-fuel (DF) engines, in which premixed natural gas and air in an open-type combustion chamber is ignited by diesel-fuel pilot sprays, have been more popular for marine use than pre-chamber spark ignition (PCSI) engines because of their superior durability. However, control of ignition and combustion in DF engines is more difficult than in PCSI engines. In this context, this study focuses on the ignition stability of n-heptane pilot-fuel jets injected into a compressed premixed charge of natural gas and air at low-load conditions. To aid understanding of the experimental data, chemical-kinetics simulations were carried out in a simplified engine-environment that provided insight into the chemical effects of methane (CH4) on pilot-fuel ignition. The simulations reveal that CH4 has an effect on both stages of n-heptane autoignition: the small, first-stage, cool-flame-type, low-temperature ignition (LTI) and the larger, second-stage, high-temperature ignition (HTI). As the ratio of pilot-fuel to CH4 entrained into the spray decreases, the initial oxidization of CH4 consumes the OH radicals produced by pilot-fuel decomposition during LTI, thereby inhibiting its progression to HTI. Using imaging diagnostics, the spatial and temporal progression of LTI and HTI in DF combustion are measured in a heavy-duty optical engine, and the imaging data are analyzed to understand the cause of severe fluctuations in ignition timing and combustion completeness at low-load conditions. Images of cool-flame and hydroxyl radical (OH*) chemiluminescence serve as indicators of LTI and HTI, respectively. The cycle-to-cycle and spatial variation in ignition extracted from the imaging data are used as key metrics of comparison. The imaging data indicate that the local concentration of the pilot-fuel and the richness of the surrounding natural-gas air mixture are important for LTI and HTI, but in different ways. In particular, higher injection pressures and shorter injection durations increase the mixing rate, leading to lower concentrations of pilot-fuel more quickly, which can inhibit HTI even as LTI remains relatively robust. Decreasing the injection pressure from 80 MPa to 40 MPa and increasing the injection duration from 500 mu s to 760 mu s maintained constant pilot-fuel mass, while promoting robust transition from LTI to HTI by effectively slowing the mixing rate. This allows enough residence time for the OH radicals, produced by the two-stage ignition chemistry of the pilot-fuel, to accelerate the transition from LTI to HTI before being consumed by CH4 oxidation. Thus from a practical perspective, for a premixed natural gas fuel-air equivalence-ratio, it is possible to improve the "stability" of the combustion process by solely manipulating the pilot-fuel injection parameters while maintaining constant mass of injected pilot-fuel. This allows for tailoring mixing trajectories to offset changes in fuel ignition chemistry, so as to promote a robust transition from LTI to HTI by changing the balance between the local concentration of the pilot-fuel and richness of the premixed natural gas and air. This could prove to be a valuable tool for combustion design to improve fuel efficiency or reduce noise or perhaps even reduce heat-transfer losses by locating early combustion away from in-cylinder walls.This research was sponsored in part by the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE). Optical engine experiments were conducted at the Combustion Research Facility of Sandia National Laboratories in Livermore, CA. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration (NNSA) under contract DE-NA0003525.Niki, Y.; Rajasegar, R.; Li, Z.; Musculus, MP.; García-Oliver, JM.; Takasaki, K. (2022). Verification of diesel spray ignition phenomenon in dual-fuel diesel-piloted premixed natural gas engine. International Journal of Engine Research. 23(2):180-197. https://doi.org/10.1177/146808742098306018019723

    Ruptured basilar artery aneurysm causing isolated bilateral abducens nerve palsy

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    症例は54歳,女性。頭痛を伴わない回転性めまいで発症し,診察時には両側外転神経麻痺症状のみ認められた。CT でくも膜下出血,特にprepontine cistern に厚い血腫が認められ,MRA では脳底動脈瘤が認められた。破裂脳動脈瘤に対して,コイル塞栓術を施行した。術後,新たな神経学的異常所見は認められなかった。両側神経麻痺は発症から4か月後に完全回復が得られた。外転神経麻痺には幾つかの機序が挙げられている。動脈瘤の直接的な圧迫,脳浮腫や脳内出血による頭蓋内圧の亢進,外転神経核への栄養血管の攣縮などである。本症例ではprepontine cistern に限局した血腫による圧迫が影響して両側外転神経麻痺のみで発症したと考えられたA 54-year-old woman presented withdsudden vertigo without headache. Upon admission, neurological examination revealed isolated bilateral abducens nerve palsn. Computed tomography revealed subarachnoid haemorrhage, particularly aythick haematoma, in the prepontine cistern. Magnetic resonanceAangiography)showed a ruptured basilar artery aneurysm. Endovascular coil embolization was performed for this ruptured aneurysm. Postoperatively, no new neurological deficits were observed. Bilateral abducens nerve palsy recovered and disappeared 4 months after onset.sSeveral possible mechanisms can explain the occurrence of abducens nerve palsy, including the following: a direct mass effect of the aneurysmton the abducens nerve, increased intracranial pressure induced by brain swelling or parenchymal haemorrhage, and a vasospasm of thc pontine branch of the basilar artery supplying the abducens nuclei. In this case, we speculated that the isolated bilateral abducens nerve palsy was caused by compression of the local haematoma in the prepontine cistern secondary to a ruptured basilar artery aneurysm

    Coincidence between transcriptome analyses on different microarray platforms using a parametric framework

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    A parametric framework for the analysis of transcriptome data is demonstrated to yield coincident results when applied to data acquired using two different microarray platforms. Discrepancies among transcriptome studies are frequently reported, casting doubt on the reliability of collected data. The inconsistency among observations can be largely attributed to differences among the analytical frameworks employed for data analysis. The existing frameworks normalizes data against a standard determined from the data to be analyzed. In the present study, a parametric framework based on a strict model for normalization is applied to data acquired using an in-house printed chip and GeneChip. The framework is based on a common statistical characteristic of microarray data, and each data is normalized on the basis of a linear relationship with this model. In the proposed framework, the expressional changes observed and genes selected are coincident between platforms, achieving superior universality of data compared to other methods

    Prediction of portal pressure from intraoperative ultrasonography

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    BackgroundPortal hypertension is a major risk factor for hepatic failure or bleeding in patients who have undergone hepatectomy, but it cannot be measured indirectly. We attempted to evaluate the intraoperative ultrasonography parameters that correlate with portal pressure (PP) in patients undergoing hepatectomy.MethodsWe examined 30 patients in whom PP was directly measured during surgery. The background liver conditions included chronic viral liver disease in seven patients, chemotherapy-associated steatohepatitis in four patients, fatty liver in one patient, hepatolithiasis in one patient, obstructive jaundice in one patient, and a normal liver in 16 patients. A multivariate logistic analysis and linear regression analysis were conducted to develop a predictive formula for PP.ResultsThe mean PP was 10.4 ± 4.1 mm Hg. The PP tended to be increased in patients with chronic viral hepatitis. A univariate analysis identified the association of the six following parameters with PP: the platelet count and the maximum (max), minimum (min), endo-diastolic, peak-systolic, and mean velocity in the portal vein (PV) flow. Using multiple linear regression analysis, the predictive formula using the PV max and min was as follows: Y (estimated PP) = 18.235?0.120 × (PV max.[m/s])?0.364 × (PV min). The calculated PP (10.44 ± 2.61 mm Hg) was nearly the same as the actual PP (10.43 ± 4.07 mm Hg). However, there was no significant relationship between the calculated PP and the intraoperative blood loss and post hepatectomy morbidity.ConclusionsThis formula, which uses ultrasonographic Doppler flow parameters, appears to be useful for predicting PP

    Molecular analysis of the BCR-ABL1 kinase domain in chronic-phase chronic myelogenous leukemia treated with tyrosine kinase inhibitors in practice: Study by the Nagasaki CML Study Group

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    An appropriate trigger for BCR-ABL1 mutation analysis has not yet been established in unselected cohorts of chronic-phase chronic myelogenous leukemia patients. We examined 92 patients after 12 months of tyrosine kinase inhibitor (TKI) treatment in Nagasaki Prefecture, Japan. Univariate analysis revealed that significant factors associated with not attaining a major molecular response (MMR) were the presence of the minor BCR-ABL1 fusion gene, a low daily dose of TKI, and the emergence of BCR-ABL1 kinase domain mutations conferring resistance to imatinib. Factors associated with the loss of sustained MMR were a low daily dose of TKI and the emergence of alternatively spliced BCR-ABL1 mRNA with a 35-nucleotide insertion. Taken together, our results suggest that the search for BCR-ABL1 mutations should be initiated if patients have not achieved MMR following 12 months of TKI treatment

    Practical action levels for chelation therapy in plutonium inhalation using nose swab

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    The aim of this study is to propose action levels for chelation therapy in the case of inhalation of plutonium compounds using nose swabs. The relationship between the activity found in the nose swabs and early faecal excretion was investigated using actual cases at JAEA-NFCEL. The ratio was found to be in log-normal distribution. The action levels based on the activity of nose swab corresponding to 10 ALI (200 mSv) are determined for the facilities at JAEA-NFCEL by using the relationship and specific information such as isotopic ratio and physicochemical characteristics of plutonium compounds
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