1,793 research outputs found

    Verification Of Measurements Of Lumbar Spinal Dimensions In T1- And T2-weighted Magnetic Resonance Imaging Sequences

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    BACKGROUND CONTEXT: Magnetic resonance imaging (MRI) is commonly used to assess patients with lumbar spinal stenosis. No single MRI sequence has been shown to be superior in spinal canal measurements. There are also cost concerns for the increased clinical and research use of MRI. Using only a single sequence may lower the financial burden; however, this requires spinal canal measurements in both T1 and T2 MRI to be reliable. Evidence for this is currently lacking. PURPOSE: The aim of this study was to determine the intra- and inter-reader reliability of MRI measurements of the lumbar spine and the reliability of measurements using T1- and T2-weighted MRI films. STUDY DESIGN/SETTING: Retrospective study. PATIENT SAMPLE: Forty-two randomly selected patients who underwent spinal stenosis surgery. OUTCOME MEASURES: Lumbar spinal canal measurements and reliability analysis between T1- and T2-weighted MRI. METHODS: Qualitative ratings of MRI features were performed according to previously published criteria by 2 independent readers (JP-YC, HS). Measurements in axial scan included midline anteroposterior (AP) vertebral body diameter, midvertebral body width, midline AP spinal canal diameter, midline AP dural sac diameter, spinal canal width/interpedicular distance, pedicle width (right and left), and lamina angle. Measurements in the sagittal scan included midline AP body diameter, midvertebral body height, and AP spinal canal diameter. Cronbach alpha was used to characterize intra- and inter-reader reliability for qualitative rating data. Similarly, T1 and T2 comparison also was performed in the same manner. RESULTS: Good to excellent intra- and interobserver reliability was obtained for all measurements. Reliability analysis of all T1 and T2 measurements was excellent. CONCLUSIONS: Either T1 or T2 images can be used for measurements of spinal canal dimensions. These findings are of importance, as not every patient undergoing preoperative MRI assessment will necessarily have both sequences performed and only a single sequence is required for research studies. Our findings are also of relevance in measurement of lumbar canal diameters.postprin

    Dust Explosion Characteristics of Cellulose Acetates with Different Degrees of Acetylation

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    PresentationIn this work, the relation between various degrees of acetylation (CAs) of Cellulose acetate (CA) to dust explosion characteristics as minimum explosible concentration (MEC) and minimum ignition energy (MIE) have been studied. Also, we attempt to clarify the relative of moisture content and water adsorption to cellulose, cellulose ester as CA and cellulose ether as Methyl cellulose (MC), Ethyl cellulose (EC), Hydroxyethyl cellulose (HEC), Hydroxypropyl cellulose (HPC), and sodium carboxymethyl cellulose (CMC) to MEC and MIE have been studied. We found that the chemical derivatives have significant on thermal behavior of cellulose which Td of CA shifted to higher temperature because of acetate derivative effect. Meanwhile, Td of cellulose ethers as MC, EC, HEC, HEC and CMC were shifted to lower temperature. Moreover, CAs was not evident effect to Td of CA. Moisture content of cellulose powder had not significant on MEC of both air dry and absolute dry powder were 55 g/m3. But, we found MEC was relative to its moisture content of CA which absolute dry was more sensitive on explosion than dry CA powder. However, MEC was consistent with the hydrophilicity index at 75%RH of dry and absolute dry of cellulose, cellulose acetate and cellulose ethers in present work. MIE was not corresponding to moisture content of cellulose ether and cellulose ester but it was relative to cellulose. The results from our experiments, comparing with CAs, chemical derivatives have more significant on moisture adsorption, thermal stability and dust explosion characteristics of cellulose

    Defining clinically relevant values for developmental spinal stenosis: a large-scale magnetic resonance imaging study

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    STUDY DESIGN: Case-control study. OBJECTIVE: The aim of this study was to define clinically relevant relative and critical (absolute) magnetic resonance imaging values of lumbar spinal stenosis in a cohort of 100 surgical cases and 100 asymptomatic controls. SUMMARY OF BACKGROUND DATA: Developmental spinal stenosis is a precipitating factor in patients presenting with lumbar canal stenosis. Yet, due to a lack of agreement on definitions and methods of assessment, as well as ethnic-specific normative values, its prevalence and significance is not known. METHODS: This was a case-control study comparing 100 age and sex-matched asymptomatic, volunteers with that of 100 patients who underwent surgery for spinal stenosis. All patients were of Chinese ethnicity and their details were blinded to 2 observers. Spinal stenosis parameters were measured on the basis of axial (pedicle level) and sagittal (midsagittal) magnetic resonance images. RESULTS: Anteroposterior spinal canal diameters change with levels. At each level, patients were found to have significantly narrower anteroposterior canal diameters than controls. By use of receiver operating characteristic curve, we defined developmental spinal stenosis if the anteroposterior canal diameter was at L1 <20 mm, L2 <19 mm, L3 <19 mm, L4 <17 mm, L5 <16 mm, and at S1 <16 mm on the basis of a value including 50% of controls and demonstrated best sensitivity and specificity. Furthermore, for L4, L5, and S1, critical stenosis values could be defined, below which almost all subjects needed surgery, these were L4 <14 mm, L5 <14 mm, and S1 <12 mm. CONCLUSION: This is the largest magnetic resonance imaging-based study with standardized measurements and comparable groups to determine clinically relevant magnetic resonance imaging criteria for lumbar spinal stenosis. The findings strongly suggest that developmental stenosis plays an important role in the pathogenesis of symptomatic spinal stenosis. Critical values of stenosis below which symptoms were highly likely were defined. These will need to be validated by longitudinal studies in future. However, they may possess clinical utility in determining the appropriate levels requiring canal-widening surgery.Level of Evidence: 3.postprin

    Thermal Behavior and Dust Explosion Characteristics of Spent Coffee Grounds and Jatropha as Biodiesel Feedstock

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    PresentationThis work examined the minimum explosion limit (MEL), minimum ignition energy (MIE), cohesion, dispersibility, decomposition temperature (Td) and burning rates of spent coffee ground (SCG), jatropha kernel (JK) and jatropha shell (JS) were studied. The MIE values of oily SCG containing 21.3 wt% and oil-extracted SCG were 35 and 120 g m-3 , respectively. Moreover, cohesion of oily SCG and oil-extracted SCG were high level and low level, respectively. It was found that MIE of oily SCG containing 21.3wt% of oil was low although high cohesion. While oil-extracted jatropha kernels and shells had MEL values of 45 and 110 g m-3 , respectively. However, Oily JK containing 60.7 wt% of oil was not exploded reason for high cohesion and no form dust cloud. The MIE values of untreated SCG, oil-extracted SCG, oil-extracted JK and JS were found to be >3000, >3000, 1515, and >3000 mJ, respectively. These biomasses were needed high energy ignition for explosion. Burning rates of JK and JS were 0.21 and 0.04 mm s-1, respectively, these values were very slow compared with cellulose used as a reference materials was 0.67 mm s-1. Besides SCG were not capable of ignition. The Td of both untreated SCG and oil-extracted SCG were 240 and 241 °C while the Td of untreated JK (60.7wt% oil), oil-extracted JK, and JS were 195, 189, and 233 ̊C indicating that the ignition temperature is influenced by oil content. Consequently, the results demonstrate that oily solid biomasses such as SCG and jatropha are associated with a high risk of fire, dust explosion, and related incident

    Ten YearsΒ» Experience of Aortic Aneurysm Associated with Systemic Lupus Erythematosus

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    AbstractBackground: aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with systemic lupus erythematosus (SLE). The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in these patients. Methods: among 429 patients operated on for abdominal aortic aneurysm (AAA) during the past 10 years, five cases with SLE were treated surgically. Their clinical data were reviewed, and the resected aneurysmal wall of the five patients was also examined histologically. Results: the mean age of the patients with SLE was 55 years, which was statistically younger than that of the other patients (mean 77 years, s.d. 7.9, p <0.05). They had received long-term corticosteroid therapy for the treatment of SLE for a mean of 23 years. Histologically, destruction of the medial elastic lamina was characteristic. Four patients had no complications in the postoperative follow-up period (mean 4 years), while the remaining patient died of rupture of a dissecting aneurysm two years after operation.Conclusion : prolonged steroid therapy may play a major role in accelerating atherosclerosis, which can result in aortic aneurysmal enlargement, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with SLE

    ΠžΡ€Π³Π°Π½ΠΈΠ·Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Π΅ Ρ€Π΅Π·Π΅Ρ€Π²Ρ‹ ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΡ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ Ρ‚Ρ€ΡƒΠ΄Π° Π½Π° прСдприятиях Π½Π΅Ρ„Ρ‚Π΅Π³Π°Π·ΠΎΠ²ΠΎΠΉ отрасли

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    ΠŸΡ€ΠΎΠ±Π»Π΅ΠΌΠ° ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΡ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ Ρ‚Ρ€ΡƒΠ΄Π° Π² соврСмСнной экономикС России ΠΈΠΌΠ΅Π΅Ρ‚ Π·Π½Π°Ρ‡ΠΈΡ‚Π΅Π»ΡŒΠ½ΡƒΡŽ Π°ΠΊΡ‚ΡƒΠ°Π»ΡŒΠ½ΠΎΡΡ‚ΡŒ, ΠΏΠΎΡΠΊΠΎΠ»ΡŒΠΊΡƒ ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΠ΅ уровня ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ Ρ‚Ρ€ΡƒΠ΄Π° являСтся ваТнСйшим условиСм ΡΠΎΡ†ΠΈΠ°Π»ΡŒΠ½ΠΎ-экономичСского развития общСства, устойчивого экономичСского роста ΠΈ ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΡ конкурСнтоспособности Π½Π°Ρ†ΠΈΠΎΠ½Π°Π»ΡŒΠ½ΠΎΠΉ экономики. ΠΠΊΡ‚ΡƒΠ°Π»ΡŒΠ½ΠΎΡΡ‚ΡŒ прСдставлСнного исслСдования опрСдСляСтся Π½Π΅ΠΎΠ±Ρ…ΠΎΠ΄ΠΈΠΌΠΎΡΡ‚ΡŒΡŽ ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΡ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ Ρ‚Ρ€ΡƒΠ΄Π° Π½Π° соврСмСнных прСдприятиях России, Ρ‡Ρ‚ΠΎ ΠΌΠΎΠΆΠ΅Ρ‚ Π±Ρ‹Ρ‚ΡŒ достигнуто Π·Π° счСт Ρ€Π΅Π°Π»ΠΈΠ·Π°Ρ†ΠΈΠΈ ΠΎΡ€Π³Π°Π½ΠΈΠ·Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… Ρ€Π΅Π·Π΅Ρ€Π²ΠΎΠ² роста. ЦСлью исслСдования являСтся структурированиС Ρ„Π°ΠΊΡ‚ΠΎΡ€ΠΎΠ², ΠΎΠΊΠ°Π·Ρ‹Π²Π°ΡŽΡ‰ΠΈΡ… влияниС Π½Π° ΡƒΡ€ΠΎΠ²Π΅Π½ΡŒ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ Ρ‚Ρ€ΡƒΠ΄Π°, ΠΏΠΎΠ΄Ρ‚Π²Π΅Ρ€ΠΆΠ΄Π΅Π½ΠΈΠ΅ значимости ΠΎΡ€Π³Π°Π½ΠΈΠ·Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… Ρ€Π΅Π·Π΅Ρ€Π²ΠΎΠ² роста, апробация ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΈΠΊΠΈ выявлСния ΠΎΡ€Π³Π°Π½ΠΈΠ·Π°Ρ†ΠΈΠΎΠ½Π½Ρ‹Ρ… Ρ€Π΅Π·Π΅Ρ€Π²ΠΎΠ² ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΡ ΠΏΡ€ΠΎΠΈΠ·Π²ΠΎΠ΄ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΡΡ‚ΠΈ Ρ‚Ρ€ΡƒΠ΄Π°. ΠœΠ΅Ρ‚ΠΎΠ΄Ρ‹ исслСдования. Π’ настоящСй Ρ€Π°Π±ΠΎΡ‚Π΅ нашли ΠΏΡ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΠ΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹ сбора ΠΏΠ΅Ρ€Π²ΠΈΡ‡Π½ΠΎΠΉ экономичСской ΠΈΠ½Ρ„ΠΎΡ€ΠΌΠ°Ρ†ΠΈΠΈ, Π²ΠΊΠ»ΡŽΡ‡Π°Ρ Π°Π½Π°Π»ΠΈΠ· Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°Ρ‚Π΅Π»ΡŒΠ½Ρ‹Ρ… ΠΈ Π½ΠΎΡ€ΠΌΠ°Ρ‚ΠΈΠ²Π½ΠΎ-ΠΏΡ€Π°Π²ΠΎΠ²Ρ‹Ρ… Π°ΠΊΡ‚ΠΎΠ² Π Π€, ΠΎΡ„ΠΈΡ†ΠΈΠ°Π»ΡŒΠ½Ρ‹Ρ… статистичСских Π΄Π°Π½Π½Ρ‹Ρ…, Π΄Π°Π½Π½Ρ‹Ρ… ΠΏΡƒΠ±Π»ΠΈΡ‡Π½ΠΎΠΉ отчСтности отСчСствСнных прСдприятий, Π°Π½Π°Π»ΠΈΠ· ΠΏΡ€ΠΎΡ‡ΠΈΡ… ΠΎΡ‚ΠΊΡ€Ρ‹Ρ‚Ρ‹Ρ… источников ΠΈΠ½Ρ„ΠΎΡ€ΠΌΠ°Ρ†ΠΈΠΈ, систСмный ΠΏΠΎΠ΄Ρ…ΠΎΠ΄, ΠΌΠ΅Ρ‚ΠΎΠ΄Ρ‹ статистичСского ΠΈ ΡΡ€Π°Π²Π½ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠ³ΠΎ Π°Π½Π°Π»ΠΈΠ·Π°. The country's labor productivity in modern Russia over recent years has acquired impressive relevance. Since it is a key indicator of overall economic efficiency, strong labor productivity growth has always been a sufficient condition for socio-economic development, economic stability and enhancing competitiveness of the national economy. The relevance of the study is determined by the urgency of the labor productivity growth at the modern Russian factories that can be achieved through realization of organizational reserves. The main aim of the study is identifying and structuring the factors that seem to affect labor productivity level. It is also pointed at corroborating the necessity of labor productivity growth and approbation of organizational reserves seeking method. Methods. In the present work different methods of information gathering and processing were used to obtain the economic data including the analysis of appropriate laws and regulations, official statistics, companies' public statements and reporting and other open available resources. Also system approach, comparative and statistical analysis were adopted in this research

    SATB1 (SATB homeobox 1)

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    Review on SATB1 (SATB homeobox 1), with data on DNA, on the protein encoded, and where the gene is implicated

    Selection of fusion levels in adolescent idiopathic scoliosis (AIS) using the fulcrum bending radiograph prediction: verification based on pedicle screw strategy

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    E-Poster - Adolescent Idiopathic Scoliosis: no. 297Utilizing the fulcrum bending radiographic technique to assess curve flexibility to aid in the selection of fusion levels, a prospective radiographic study was performed to assess the safety and effectiveness of pedicle screw fixation with alternate level screw strategy (ALSS) for thoracic AIS. This study suggests that ALSS obtains greater deformity correction than hook and hybrid systems, and improves balance without compromising fusion levels.postprin

    Landau Model for Commensurate-Commensurate Phase Transitions in Uniaxial Improper Ferroelectric Crystals

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    We propose the Landau model for lock-in phase transitions in uniaxially modulated improper ferroelectric incommensurate-commensurate systems of class I. It includes Umklapp terms of third and fourth order and secondary order parameter representing the local polarization. The corresponding phase diagram has the structure of harmless staircase, with the allowed wave numbers obeying the Farey tree algorithm. Among the stable commensurate phases only those with periods equal to odd number of lattice constants have finite macroscopic polarizations. These results are in excellent agreement with experimental findings in some A2BX4 compounds.Comment: 9 pages, 5 figures, revtex, to be published in Journal of Physics: Cond. Matter as a Letter to the Edito
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