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Sample records for circumferential thoracolumbar corrective

  1. Minimal Invasive Circumferential Management of Thoracolumbar Spine Fractures

    Directory of Open Access Journals (Sweden)

    S. Pesenti

    2015-01-01

    Full Text Available Introduction. While thoracolumbar fractures are common lesions, no strong consensus is available at the moment. Objectives. The aim of this study was to evaluate the results of a minimal invasive strategy using percutaneous instrumentation and anterior approach in the management of thoracolumbar unstable fractures. Methods. 39 patients were included in this retrospective study. Radiologic evaluation was based on vertebral and regional kyphosis, vertebral body height restoration, and fusion rate. Clinical evaluation was based on Visual Analogic Score (VAS. All evaluations were done preoperatively and at 1-year follow-up. Results. Both vertebral and regional kyphoses were significantly improved on postoperative evaluation (13° and 7° versus −1° and −9°  P<0.05, resp. as well as vertebral body height (0.92 versus 1.16, P<0.05. At 1-year follow-up, mean loss of correction was 1°. A solid fusion was visible in all the cases, and mean VAS was significantly reduced form 8/10 preoperatively to 1/10 at the last follow-up. Conclusion. Management of thoracolumbar fractures using percutaneous osteosynthesis and minimal invasive anterior approach (telescopic vertebral body prosthesis is a valuable strategy. Results of this strategy offer satisfactory and stable results in time.

  2. The height of the osteotomy and the correction of the kyphotic angle in thoracolumbar kyphosis

    Institute of Scientific and Technical Information of China (English)

    HAO Chou-kuan; LI Wei-shi; CHEN Zhong-qiang

    2008-01-01

    Background This study investigated the relationship between the height of osteotomy and the correction of the kyphotic angle during posterior closing wedge osteotmy with instrumentation and the spinal osteotomy with cage inserting into the intervertebral gap and closing posteriorly by a single posterior approach in thoracolumbar kyphosis, and using this relationship as the basis of the preoperative design.Methods From April 1996 to June 2007, 30 thoracolumbar kyphosis patients with complete medical records and clear X-ray photograms have undergone operation. Of these 30 cases, 16 cases underwent posterior closing wedge osteotmywith instrumentation while the height of the osteotomy and the correction of the angle have been measured; 14 casesunderwent spinal osteotomy with cage inserting into the intervertebral gap and closing posteriorly by a single posteriorapproach while the height of the osteotomy, the height and the place of the cage and the correction of the angle were also measured. A simple geometrical model was simulated to calculate the relationship between the height of the osteotomy and the correction of the angle and these results are finally compared with the data coming from the actual measuring by the Wilcoxon statistic method.Results The distribution of data from the 16 cases by posterior closing wedge osteotomy with instrumentation was as such: 9 male and 7 female, the mean age was 49.2 years (range 38-70), the kyphosis improved from an average of 30° (range 15°-45°) preoperatively to 4° (range -26°-30°) postoperatively, the kyphosis was corrected on average 2.5° per 1 mm in the height of the osteotomy. The results from the simple geometrical model were that the mean of the correction of the angle per 1 mm was 2.2°. As a result, there was no significant difference (P >0.05) when comparing the measurement collected with the result simulated from the geometric model. The distribution of data from the 14 cases by spinal osteotomy with cage

  3. Sextant percutaneous pedicle screw fixation for correcting single-segment thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    Ming Jiang-hua; Zheng Hui-feng; Zhao Qi; Chen Qing; Wang Gang

    2014-01-01

    BACKGROUND:Though the effects of conservative or traditional open reduction and internal fixation in the treatment of thoracolumbar fractures are reliable and satisfactory for most cases, two methods also have shortages. Minimal-invasive percutaneous pedicle screw system provides a new available method. OBJECTIVE:To investigate the clinical effect of Sextant percutaneous pedicle screw system in the treatment of thoracolumbar fractures. METHODS:A total of 55 patients, who had undergone percutaneous pedicle screw fixation using Sextant system (25 patients) or traditional open internal fixation (30 patients) for single-level vertebral body compression fractures in Department of Orthopedics of Renmin Hospital of Wuhan University from February 2011 to January 2013, were enrol ed in this study. RESULTS AND CONCLUSION:Except two patients in traditional open internal fixation group were lost after discharge, al other patients were fol owed up for 8-14 months. Operative time, intraoperative blood loss, postoperative drainage amount and hospital day were better in percutaneous pedicle screw fixation group than in the traditional open internal fixation group (P0.05). The results show that percutaneous pedicle screw fixation using Sextant system has a satisfactory outcome in the treatment of thoracolumbar fractures. However, obeying indication strictly is very important for clinical application.

  4. Surgical treatment in thoraco-lumbar region fractures.

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    Jorge Alberto Jerez Labrada

    2008-08-01

    Full Text Available Background: thoraco-lumbar fractures may affect people at any moment of their lives, especially at their most fruitful and useful stage. Its correct diagnosis and treatment may directly influence in the posterior evolution of the patients. Objectives: to evaluate the results of the surgical treatment in thoraco-lumbar region fractures. Methods: a descriptive retrospective correlational study of series cases which included 54 patients attended due to thoraco-lumbar region fractures in the University Hospital “Dr. Gustavo Aldereguía Lima” in Cienfuegos city, Cuba from January 1999 to June 2007. Age, sex, etiology of the fracture, type and level of the fractures, associated diseases, surgical techniques used for, pre and post operatory neurological damage, usage of metilprednisolone, complications and final results were the variables taken into consideration in this study. Results: most of the patients belonged to male sex under the age of 45. The totality of the cases had type IV fracture, and a great part of them had Denis type II fracture having surgical treatment. The causes of the lesions were traffic accidents, working accidents and height falls. The most useful surgical techniques were posterior decompression, instrumentation and fusion. Surgery improved the neurological damage in almost half of sick patients with this condition. Complications were minimum and rupture of the implant was predominant. Conclusion: surgical treatment in thoraco-lumbar region fractures had satisfactory results in our milieu.

  5. Endoscopic treatment of spinal trauma at the thoracolumbar junction

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    Beisse Rudolf

    2007-01-01

    Full Text Available Attempts of treating unstable fractures of the thoracolumbar junction by posterior reduction and fixation alone often result in a significant loss of correction, especially in lesions where a severe destruction of the vertebral body and the intervertebral disc is present. The conventional open approaches like classic thoraco-phreno-lumbotomy produces additional iatrogenic trauma at the lateral chest and abdominal wall which not rarely lead to intercostal neuralgia, as well as post-thoracotomy syndromes. The endoscopic trans-diaphragmatic approach described below opens up the whole thoracolumbar junction to a minimally invasive procedure allowing one to perform all the procedures needed for a full reconstruction of the anterior column of the spine like corpectomy, decompression, vertebral body replacement and anterior plating. The key to address also the subdia-phragmal and retroperitoneal section of the thoracolumbar junction is a partial detachment of the diaphragm which runs along the attachment at the spine and the ribs. The technique was published first in 1998 and has been used now in 650 endoscopic procedures at the thoracolumbar junction out of a total of more than 1300 thoracoscopic operations of the spine in the BG Unfallklinik Murnau, Germany since 1996.

  6. Management of thoracolumbar spine trauma An overview

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    S Rajasekaran

    2015-01-01

    Full Text Available Thoracolumbar spine fractures are common injuries that can result in significant disability, deformity and neurological deficit. Controversies exist regarding the appropriate radiological investigations, the indications for surgical management and the timing, approach and type of surgery. This review provides an overview of the epidemiology, biomechanical principles, radiological and clinical evaluation, classification and management principles. Literature review of all relevant articles published in PubMed covering thoracolumbar spine fractures with or without neurologic deficit was performed. The search terms used were thoracolumbar, thoracic, lumbar, fracture, trauma and management. All relevant articles and abstracts covering thoracolumbar spine fractures with and without neurologic deficit were reviewed. Biomechanically the thoracolumbar spine is predisposed to a higher incidence of spinal injuries. Computed tomography provides adequate bony detail for assessing spinal stability while magnetic resonance imaging shows injuries to soft tissues (posterior ligamentous complex [PLC] and neurological structures. Different classification systems exist and the most recent is the AO spine knowledge forum classification of thoracolumbar trauma. Treatment includes both nonoperative and operative methods and selected based on the degree of bony injury, neurological involvement, presence of associated injuries and the integrity of the PLC. Significant advances in imaging have helped in the better understanding of thoracolumbar fractures, including information on canal morphology and injury to soft tissue structures. The ideal classification that is simple, comprehensive and guides management is still elusive. Involvement of three columns, progressive neurological deficit, significant kyphosis and canal compromise with neurological deficit are accepted indications for surgical stabilization through anterior, posterior or combined approaches.

  7. Less invasive surgical treatment of traumatic thoracolumbar fractures

    NARCIS (Netherlands)

    Verlaan, J.J.

    2004-01-01

    Less invasive surgical treatment of traumatic thoracolumbar fractures. In this thesis various strategies were employed to evaluate the posibilities of reducing the invasiveness of the surgical treatment of traumatic thoracolumbar fractures. A systematic review of the literature suggested that adequ

  8. IMAGING DIAGNOSIS OF THORACOLUMBAR BURST FRACTURES

    Institute of Scientific and Technical Information of China (English)

    Li-yang Dai

    2004-01-01

    Objective To review imaging use in the diagnosis ofthoracolumbar burst fractures and to determine the diagnostic value of different imaging methods.Methods One hundred and fourteen patients with 120 thoracolumbar burst fractures were retrospectively reviewed. Plain radiographs were available in all cases; CT scans and MRI were obtained in 96 and 74 cases, respectively.Results A total of 27 burst fractures were misdiagnosed as other types of fractures on radiographs alone, and accounted for 22.5% of all fractures. The results indicated that plain radiographs often fail to delineate the pathological features of thoracolumbar burst fractures, leading to delay in diagnosis.Conclusion In regard to thoracolumbar injury diagnosis, burst fractures should be differentiated from compression fractures. CT should be routinely indicated and MRI examination, when necessary, may be simultaneously considered.

  9. A new brace treatment similar for adolescent scoliosis and kyphosis based on restoration of thoracolumbar lordosis. Radiological and subjective clinical results after at least one year of treatment

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    van Loon Piet JM

    2012-10-01

    Full Text Available Abstract Study design A prospective treatment study with a new brace was conducted Objective. To evaluate radiological and subjective clinical results after one year conservative brace treatment with pressure onto lordosis at the thoracolumbar joint in children with scoliosis and kyphosis. Summary of background data Conservative brace treatment of adolescent scoliosis is not proven to be effective in terms of lasting correction. Conservative treatment in kyphotic deformities may lead to satisfactory correction. None of the brace or casting techniques is based on sagittal forces only applied at the thoracolumbar spine (TLI= thoracolumbar lordotic intervention. Previously we showed in patients with scoliosis after forced lordosis at the thoracolumbar spine a radiological instantaneous reduction in both coronal curves of double major scoliosis. Methods A consecutive series of 91 children with adolescent scoliosis and kyphosis were treated with a modified symmetric 30 degrees Boston brace to ensure only forced lordosis at the thoracolumbar spine. Scoliosis was defined with a Cobb angle of at least one of the curves [greater than or equal to] 25 degrees and kyphosis with or without a curve Results Before treatment start ‘in brace’ radiographs showed a strong reduction of the Cobb angles in different curves in kyphosis and scoliosis groups (sagittal n = 5 all p Conclusion Conservative treatment using thoracolumbar lordotic intervention in scoliotic and kyphotic deformities in adolescence demonstrates a marked improvement after one year also in clinical and postural criteria. An effect not obtained with current brace techniques.

  10. Radiological outcome of transpedicular screws fixation in the management of thoracolumbar spine injury

    International Nuclear Information System (INIS)

    Traumatic fracture of the spine is a serious neurosurgical condition that has serious impact on the patient's quality of life. Thoracolumbar junction is the most common site of spinal injuries. The aims of management of thoracolumbar spinal fractures are to restore vertebral column stability, and to obtain spinal canal decompression. This ultimately leads to early mobilization of the patients. This study was conducted to compare preoperative and post-operative vertebral height, kyphotic angle and sagittal index in patients treated with pedicle screws and rods in thoracolumbar spine fractures. Methods: This cross-sectional study was conducted in the department of Neurosurgery, Hayatabad Medical Complex, Peshawar from 1st February 2010 to 31st July 2011. A total 161 patients with unstable thoracolumber spine fracture were included in this study. In these patients fixation was done through transpedicle screws with rods. Anteroposterior and lateral views X-rays of thoraco-lumbar spine were done pre and post operatively. Results: Out of 161 patients, 109 (67.7%) were males and 52 (32.3%) females. The age of patients ranged from 20 to 70 years (mean 42.2 years) with 71 (44.1%) in the age range of 31-40 years. Preoperative average vertebral height was 9.4194 mm while postoperative average was 19.642 mm. The mean kyphosis was 23.06 degree preoperatively. Immediately after surgery the average correction of kyphosis was 9.45 degree. The pre-operative average sagittal index was 19.38 degree, which was reduced to an average 5.41 degree post operatively. Conclusions: Transpedicular fixation for unstable thoraco-lumbar spinal fractures achieves a stable fracture segment with improvement of vertebral height, kyphotic angle and sagittal index. Hence, preventing the secondary spinal deformities. (author)

  11. TREATMENT OF UNSTABLE THORACOLUMBAR FRACTURES IN PEDIATRIC PATIENTS

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    Roberto Chapa Sosa

    2015-09-01

    Full Text Available Objective:To analyze the characteristics of unstable thoracolumbar fractures in the pediatric population.Methods:A retrospective cross-sectional study was conducted with pediatric patients (0 to 15 years who presented with unstable thoracolumbar fracture with or without neurological damage. Twenty-four operated patients were analyzed: 13 male and 11 female.Results:Falls from height are the most common cause, being the thoracolumbar junction the anatomical site most frequently injured.Conclusion:The thoracolumbar fractures are rare in the pediatric population, as well as post-surgical instrumentation structural deformities.

  12. CT in diagnosis of thoracolumbar region diseases

    International Nuclear Information System (INIS)

    The lumbalgia caused by affected thoracolumbar transition (Th11-L2) imitates the clinical symptomatic of disc lesions in the lower lumbar segments. The syndrome is presented by a pain projected in the area of the three branchings of the spinal nerves, coming from thoracolumbar segments. The aim of this study is to determine the pathological processes, causing the clinical symptoms of this syndrome, using computer tomography. 51 patients are studied with clinically proved thoracolumbar transition syndrome: 14 men and 37 women. CT slices of 96 vertebral segments are made. Two patient are scanned at Th11-Th12 and L1-L2. Only Th12-L1 scans are made on 10 patients and 42 are made on two neighbouring segments (41 of them on Th11-Th12 and Th12-L1 and one on Th11-L1 and L1-L2). An asymmetry (facet tropism) has been found at 59 levels, 21 if them are with spondiloarthrosis. Spondiloarthrosis has been found in 24 segments - 21 of them with osteochondrosis, one with disc prolapse, and 2 with disc protrusion. It is also found osteoporotic changes osteolysis in multiple myeloma, metastasis etc. During the 3 level examination no evidence for either of the mentioned changes is obtained. The CT slices of two neighbouring segments showed an unexpected change from thoracic to lumbar type of the intervertebral joints in 34 patients. The results from this study support the hypothesis about joints origin of the clinical symptoms of the thoracolumbar transition and demonstrate the importance of the computer tomography as a diagnostic method in this disease

  13. Review of 31 cases of anterior thoracolumbar fixation with the anterior thoracolumbar locking plate system.

    Science.gov (United States)

    Wilson, J A; Bowen, S; Branch, C L; Meredith, J W

    1999-07-15

    Anterior fixation devices for the thoracolumbar spine have gained wide acceptance as viable alternatives to long-segment posterior fixation in cases of thoracolumbar spine trauma. This review was undertaken to evaluate the safety and efficacy of the Synthes anterior thoracolumbar locking plate (ATLP) system. Over a 3-year period, 31 patients with unstable traumatic fractures of the thoracolumbar spine underwent corpectomy, placement of a structural bone graft, and anterior fixation in which the Synthes ATLP system was used. Long-term follow-up data were obtained in 29 patients. Two patients were lost to follow up, one at 4 months and the other at 1 year. In the remaining patients, the average length of follow up was 20 months. In all patients radiographic evidence of solid bone fusion was demonstrated on follow-up plain x-ray films, and there were no signs or symptoms of pseudarthrosis. No patient suffered neurological deterioration as a result of surgery, and there was relatively little morbidity associated with this plating system. To date, none of the patients in this study has developed any delayed complications related to the fixation device. In one patient, who had sustained a severe flexion injury, loosening of the anterior fixation device occurred, and the patient developed progressive kyphosis, which required a posterior stabilization procedure. These results appear slightly better than those obtained in published studies in which other anterior plating systems were used, indicating that this system is safe and effective in the treatment of unstable fractures of the thoracolumbar spine. PMID:16918232

  14. Postoperative Disc Wedging in Adolescent Idiopathic Thoracolumbar/Lumbar Scoliosis: a Comparison of Anterior and Posterior Approaches

    Institute of Scientific and Technical Information of China (English)

    Bin Yu; Yi-peng Wang; Gui-xing Qiu; Jian-guo Zhang; Jian-xiong Shen; Yu Zhao; Shu-gang Li; Qi-yi Li

    2010-01-01

    Objective To evaluate the different influences of anterior and posterior correction and fusion ap-proaches upon disc wedging in adolescent idiopathic thoracolumbar/lumbar scoliosis.Methods The retrospective study was conducted with the medical records and radiographs of ado-lescent idiopathic thoracolumbar/lumbar scoliosis patients that underwent anterior (group A) or posterior (group B) correction and fusion surgery from December 1998 to May 2008. The correction of the main curve and changes of the disc wedging were analyzed.Results Fifty-three patients were included, 26 in group A and 27 in group B. The mean coronal Cobb angles of the main curve in group A and group B were significantly corrected after surgery (P0.05). The difference between disc wedging at final follow-up and that after surgery was significant in group A (P0.05). Between the two groups, group A had larger disc angles after operation and at final follow-up (P<0.05), and a greater loss of disc angle (P<0.05).Conclusion For adolescent idiopathic thoracolumbar/lumbar scoliosis, posterior approach using all pedicle screws might produce a better result in terms of disc wedging compared with anterior approach.

  15. 一期后路全脊椎切除治疗胸腰段结核僵硬性角状后凸畸形%One-stage posterior vertebral column resection to correct rigid and severe post-tubercular kyphotic deformities in thoracolumbar spine

    Institute of Scientific and Technical Information of China (English)

    曹奇; 廖雄; 杨铁军; 唐国军; 陈亮元; 陈小明; 唐晓军

    2011-01-01

    preoperative kyphosis was 49. 9° ± 12. 5° and in the immediate postoperative period was 18. 3° ±3. 4° with an average postoperative kyphosis correction of 31. 7° ±10. 9° and correction rate of 62. 8% ±5. 8% . Five cases with preoperative neurological dysfunction, Frankel's grade C in 3 patients and grade D in 2 patients, but only one case in grade D postoperative showed 80% neurologic improvement. Perioperative complications occurred respectively in 2 (16. 7% ) of the 12 patients including cerebrospinal fluids leakage and superficial infections. Looseness of fixation in one case (8. 3% ) was found postoperation. The mean VAS was 7. 8 and 2. 9 in pre- and post-operation showed 62. 3% improvement in back pain relief. Fusion of the resection site was confirmed on radiographs in all patients and no neural injury was found during follow-up. Conclusion A single-stage posterior-only vertebral resection is an effective and safe way to treat post-tubercular kyphotic deformities for the thoracolumbar spine.

  16. Correction.

    Science.gov (United States)

    2015-11-01

    In the article by Heuslein et al, which published online ahead of print on September 3, 2015 (DOI: 10.1161/ATVBAHA.115.305775), a correction was needed. Brett R. Blackman was added as the penultimate author of the article. The article has been corrected for publication in the November 2015 issue. PMID:26490278

  17. 49 CFR 178.345-7 - Circumferential reinforcements.

    Science.gov (United States)

    2010-10-01

    ... circumferential reinforcement member, whether internal or external, reinforcement must be continuous around the... tank heads. (1) Circumferential reinforcement must be located so that the thickness and tensile strength of the shell material in combination with the frame and reinforcement produces...

  18. Thoracolumbar fracture with listhesis - an uncommon manifestation of child abuse

    Energy Technology Data Exchange (ETDEWEB)

    Levin, Terry L.; Blitman, Netta M. [Department of Radiology, Montefiore Medical Center, 111 E. 210th Street, Bronx, New York, NY 10467-2490 (United States); Berdon, Walter E. [Department of Radiology, Babies Hospital, New York Presbyterian Hospital, New York (United States); Cassell, Ian [Department of Radiology, Phoenix Children' s Hospital, Phoenix, AZ (United States)

    2003-05-01

    Thoracolumbar fracture with listhesis (FL) is an uncommon manifestation of child abuse (increasingly known as nonaccidental trauma), with only six prior reports in the literature. This article seeks to call attention to FL of the thoracolumbar spine in abused children and infants. We reviewed plain films, CT and MR images in seven new cases of FL of the thoracolumbar spine in abused children ages 6 months to 7 years, two of whom became paraplegic from their injuries. Findings varied from subtle listhesis of one vertebra on another to frank vertebral dislocation, most commonly at L1/2. Paravertebral calcification was present in all but one case. In two children, thoracolumbar FL was the only radiographic sign of abuse. Radiographic findings of FL of the thoracolumbar spine may be subtle and may be erroneously interpreted as due to a congenital or neoplastic cause. While other signs of child abuse should be sought, spinal injury may be the sole sign of abuse. Recognition of this entity is important to pursue the diagnosis of abuse. (orig.)

  19. Thoracolumbar fracture with listhesis - an uncommon manifestation of child abuse

    International Nuclear Information System (INIS)

    Thoracolumbar fracture with listhesis (FL) is an uncommon manifestation of child abuse (increasingly known as nonaccidental trauma), with only six prior reports in the literature. This article seeks to call attention to FL of the thoracolumbar spine in abused children and infants. We reviewed plain films, CT and MR images in seven new cases of FL of the thoracolumbar spine in abused children ages 6 months to 7 years, two of whom became paraplegic from their injuries. Findings varied from subtle listhesis of one vertebra on another to frank vertebral dislocation, most commonly at L1/2. Paravertebral calcification was present in all but one case. In two children, thoracolumbar FL was the only radiographic sign of abuse. Radiographic findings of FL of the thoracolumbar spine may be subtle and may be erroneously interpreted as due to a congenital or neoplastic cause. While other signs of child abuse should be sought, spinal injury may be the sole sign of abuse. Recognition of this entity is important to pursue the diagnosis of abuse. (orig.)

  20. Short Segment Fixation Versus Short Segment Fixation With Pedicle Screws at the Fracture Level for Thoracolumbar Burst Fracture

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    Anghel S

    2014-04-01

    Full Text Available Objective: The most prevailing surgical procedure in the treatment of thoracolumbar burst fractures, Short Segment Fixation (SSF, is often followed by loss of correction or hardware failure which may be significant enough to require another surgical intervention. In order to take advantage of its benefits but to avoid or diminish the risk and impact of associated drawbacks, some other alternatives have been lately developed among which we refer to short segment fixation with intermediate screws (SSF+IS. This article provides a comparative picture over the effectiveness of the two above-mentioned surgical treatments, focusing on their potential to prevent the loss of correction.

  1. Circumferential cracking of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  2. KumaFix fixation for thoracolumbar burst fractures: a prospective study on selective consecutive patients

    Institute of Scientific and Technical Information of China (English)

    Yan Liang; Guo Hua; Xu Zhengwei; Liu Tuanjiang; Wang Xiaodong; He Baorong; Hao Dingjun

    2014-01-01

    Background Short-segment U-shaped pedicle screw fixation has been widely used to treat thoracolumbar burst fracture.Some studies have reported the disadvantages of traditional U-shaped pedicle screw,which included a relatively high rate of adjacent segment degeneration and screw failure,including screw pullout and breakage.The purpose of this study was to assess the efficacy of open reduction and fixation using KumaFix fixation system in treatment of thoracolumbar burst fractures.Methods From June 2011 to June 2012,45 consecutive patients with thoracolumbar burst fractures were enrolled.They were randomly assigned to treatment with KumaFix (the treatment group,n=23) or traditional U-shaped pedicle screw (the control group,n=22).The patients were followed up postoperatively and were assessed with regard to radiologic and clinical outcomes.Radiologic outcomes were assessed mainly on the basis of Cobb angle and vertebral wedge angle.Clinical outcomes were evaluated mainly with use of Visual Analog Scale (VAS) for pain and the Oswestry Disability Index (ODI) Questionnaire.Results All patients were followed up from 9 to 22 months.There were no significant differences between the two groups with regard to preoperative indices.The operation time in the treatment group was significantly lower than that in the control group.Preoperative Cobb angles and vertebral wedge angles in two groups were significantly decreased after surgery,and these have been well maintained at the last follow-up with mild correction losses.The results of clinical outcome showed lower VAS and ODI scores in two groups compared with those preoperative,and the treatment group had greater improvement on the ODI compared with the control group at the last follow-up.Conclusions Compared with traditional U-shaped pedicle screw,KumaFix fixation system can achieve gradual,controlled reduction,provide enough space for bone implantation,and avoid acceleration of adjacent segment degeneration.It is an effective

  3. Circumferential TIG welding of zircaloy flow tubes

    International Nuclear Information System (INIS)

    Reactivity control mechanism consists of 10 mtr. long zircaloy flow tubes (inner and outer) with components welded to hold the absorber elements. These components were welded by the plug welding process and supplied to Madras Atomic Power Station (MAPS) and Narora Atomic Power Station (NAPS). In view of the in-service problem faced in Rajasthan Atomic Power Station (RAPS), the spot welds were modified to circumferential TIG welding with additional reinforcement. Development work was taken up for additional reinforcement with screws and circumferential TIG welding of these assemblies. The additional reinforcement with screws and spot welds were critically examined and the job was taken up and successfully completed at Narora site for Narora Atomic Power Projects (NAPP-II). Several trials were conducted for circumferential TIG welding of zircaloy. Since zircaloy is highly reactive in nature, good shielding with inert gas should be ensured to avoid weld contamination due to oxygen and nitrogen. The strength, microstructural and radiographical requirements were examined with different parameters of welding such as weld current, feed, inert gas flow and weld configuration. The strength and other requirements were achieved meeting stringent specifications and assemblies for KAPP-I were successfully completed and despatched. (author). 7 figs

  4. Correction.

    Science.gov (United States)

    2016-02-01

    In the article by Guessous et al (Guessous I, Pruijm M, Ponte B, Ackermann D, Ehret G, Ansermot N, Vuistiner P, Staessen J, Gu Y, Paccaud F, Mohaupt M, Vogt B, Pechère-Bertschi A, Martin PY, Burnier M, Eap CB, Bochud M. Associations of ambulatory blood pressure with urinary caffeine and caffeine metabolite excretions. Hypertension. 2015;65:691–696. doi: 10.1161/HYPERTENSIONAHA.114.04512), which published online ahead of print December 8, 2014, and appeared in the March 2015 issue of the journal, a correction was needed.One of the author surnames was misspelled. Antoinette Pechère-Berstchi has been corrected to read Antoinette Pechère-Bertschi.The authors apologize for this error. PMID:26763012

  5. Spontaneous fusion across the apex of severe thoracolumbar Scheuermann′s kyphosis: A surgical consideration

    Directory of Open Access Journals (Sweden)

    Tsirikos Athanasios

    2010-01-01

    Full Text Available Considerable debate exists regarding the pathogenesis, natural history and treatment of Scheuermann′s kyphosis. Surgical correction is indicated in the presence of severe kyphosis which carries the risk of neurological complications, persistent back pain and significant cosmetic deformity. This can be achieved through a posterior-only or an anteroposterior approach. Spontaneous fusion in association with Scheuermann′s kyphosis has not been previously described. This is an important consideration if surgical correction of the kyphosis is planned. Two patients with severe thoracolumbar Scheuermann′s kyphosis who developed spontaneous posterior and anteroposterior fusion across the apex of the deformity are presented. The surgical treatment and final outcome is discussed.

  6. Correction

    CERN Multimedia

    2002-01-01

    The photo on the second page of the Bulletin n°48/2002, from 25 November 2002, illustrating the article «Spanish Visit to CERN» was published with a wrong caption. We would like to apologise for this mistake and so publish it again with the correct caption.   The Spanish delegation, accompanied by Spanish scientists at CERN, also visited the LHC superconducting magnet test hall (photo). From left to right: Felix Rodriguez Mateos of CERN LHC Division, Josep Piqué i Camps, Spanish Minister of Science and Technology, César Dopazo, Director-General of CIEMAT (Spanish Research Centre for Energy, Environment and Technology), Juan Antonio Rubio, ETT Division Leader at CERN, Manuel Aguilar-Benitez, Spanish Delegate to Council, Manuel Delfino, IT Division Leader at CERN, and Gonzalo León, Secretary-General of Scientific Policy to the Minister.

  7. HISTOMORPHOLOGICAL STUDY OF THORACOLUMBAR FASCIA IN PATIENTS WITH LUMBOSACRAL DISCOPATHY

    Directory of Open Access Journals (Sweden)

    Z BEHDADIPOOR

    2000-03-01

    Full Text Available Introduction. Thoracolumbar fascia has neural ends in normal positions. It has sensory role and by inhibitory and or excitatory reflexes helps to protect vertebral column. In this research, it has been studied neural ends in thoracolumbar fascia in 42 cases. Our aim was to compare the presence of neural ends in normal individuals and those with lumbosacral discopathy. Methods. The samples were taken from one centimeter of midline at the level of L4-L5 vertebrae, since in this region the posterior layer of thoracolumbar fascia is thicker. Seven of the cases were normal and 35 were patients with lumbosacral discopathy. The samples were processed and serial sections were prepared. Six hundred and thirty sections from the serial sections were selected and 90 percent of these were stained with H&E and the rest of them were stained with Bielschowsky method. The sections were studied by light microscopy. Findings. Unlike the normal individuals, nerve corpuscles were not seen in none of our patients with lumbosacraldiscopathy.UsingBielschowsky,nerveendingswerepresentin normal individuals but they were not visible in patients with discopathy. Conclusion. It is concluded that thoracolumbar fascia in patients with discopathy had insufficient neural ends. Loss of these neural ends may be cause of decreasing proprioceptive information to nervous system and can be an initiating factor to damage the bones, ligaments and muscles.

  8. Is Circumferential Minimally Invasive Surgery Effective in the Treatment of Moderate Adult Idiopathic Scoliosis?

    OpenAIRE

    Anand, Neel; Baron, Eli M.; Khandehroo, Babak

    2014-01-01

    Background Outcomes for minimally invasive scoliosis correction surgery have been reported for mild adult scoliosis. Larger curves historically have been treated with open surgical procedures including facet resections or posterior column osteotomies, which have been associated with high-volume blood loss. Further, minimally invasive techniques have been largely reported in the setting of degenerative scoliosis. Questions/purposes We describe the effects of circumferential minimally invasive ...

  9. Massive hematothorax after thoracic spinal manipulation for acute thoracolumbar pain

    Directory of Open Access Journals (Sweden)

    Johannes Struewer

    2013-07-01

    Full Text Available Spinal manipulation usually represents a widely used and effective method for physicians in order to relieve acute patient pain and muscular dysbalance. Although life-threatening complications (e.g. pneumothorax, vertebral artery dissection, stroke after manual treatment are reported with regard to actual medical literature millions of patients undergo manual treatment to manage thoracolumbar pain each year. The authors present the case of a 17 year old male patient with a life-threatening hematothorax after thoracic high velocity spinal manipulation for acute thoracolumbar pain. The patient required emergency chest tube thoracostomy and afterwards thoracoscopic haemostasis for an intercostal venous lesion. A massive hematothorax after spinal manipulation represents an extremely rare but life-threatening complication. Physicians are encouraged to promote the benefits of manual/chiropratic therapy on the one hand but on the other hand are obliged to educate about potential serious dangers and adverse events.

  10. The prevalence of thoracolumbar kyphosis in achondroplasia: a systematic review

    OpenAIRE

    Engberts, Alexander C.; Jacobs, Wilco C. H.; Castelijns, Sanne J. A. M.; Castelein, Rene M; Vleggeert-Lankamp, Carmen L.A.

    2011-01-01

    Purpose Thoracolumbar kyphosis (TLK) is described as a common presentation in children with achondroplasia. However, the prevalence and development of TLK are ill-defined, as well as its clinical implications. The goal of this study was to assess the existing evidence on the prevalence and development of TLK from the literature. Methods A systematic literature review was performed in PubMed, EMBASE, and Thomson Reuters (ISI) Web of Knowledge. Articles were selected and evaluated with the Newc...

  11. Simultaneously anterior decompression and posterior instrumentation by extrapleural retroperitoneal approach in thoracolumbar lesions

    Directory of Open Access Journals (Sweden)

    Jain Anil

    2010-01-01

    Full Text Available Background: Anterior decompression with posterior instrumentation when indicated in thoracolumbar spinal lesions if performed simultaneously in single-stage expedites rehabilitation and recovery. Transthoracic, transdiaphragmatic approach to access the thoracolumbar junction is associated with significant morbidity, as it violates thoracic cavity; requires cutting of diaphragm and a separate approach, for posterior instrumentation. We evaluated the clinical outcome morbidity and feasibility of extrapleural retroperitoneal approach to perform anterior decompression and posterior instrumentation simultaneously by single "T" incision outcome in thoracolumbar spinal trauma and tuberculosis. Patients and Methods: Forty-eight cases of tubercular spine (n = 25 and fracture of the spine (n = 23 were included in the study of which 29 were male and 19 female. The mean age of patients was 29.1 years. All patients underwent single-stage anterior decompression, fusion, and posterior instrumentation (except two old traumatic cases via extrapleural retroperitoneal approach by single "T" incision. Tuberculosis cases were operated in lateral position as they were stabilized with Hartshill instrumentation. For traumatic spine initially posterior pedicle screw fixation was performed in prone position and then turned to right lateral position for anterior decompression by same incision and approach. They were evaluated for blood loss, duration of surgery, superficial and deep infection of incision site, flap necrosis, correction of the kyphotic deformity, and restoration of anterior and posterior vertebral body height. Results: In traumatic spine group the mean duration of surgery was 269 minutes (range 215-315 minutes including the change over time from prone to lateral position. The mean intraoperative blood loss was 918 ml (range 550-1100 ml. The preoperative mean ASIA motor, pin prick and light touch score improved from 63.3 to 74.4, 86 to 94.4 and 86 to 96 at

  12. Thoracolumbar burst fracture: what the radiologist should know

    Energy Technology Data Exchange (ETDEWEB)

    Jacob Junior, Charbel; Batista, Priscila Rossi de; Machado, Igor Cardoso; Rezende, Rodrigo, E-mail: grupodecoluna@santacasavitoria.org [Santa Casa de Misericordia de Vitoria, Vitoria, ES (Brazil); Barbosa, Diogo Miranda; Vieira, Dimitri Mori [Centro de Diagnostico por Imagem, Vitoria, ES (Brazil)

    2012-03-15

    Thoracolumbar burst fractures are defined as those fractures involving compromise of the anterior, middle and posterior vertebral columns. The treatment for such vertebral fractures still remains undefined, raising questions about the best form of intervention in these cases. Because of these doubts, imaging methods play a key role in the preoperative workup. However, several tests and measurements are performed by spine surgeons before deciding on the best approach to be adopted, with no standardization and neither consensus. The present review was aimed at standardizing and describing the main techniques and radiological findings on the basis of instability criteria adopted by surgeons in the assessment of thoracolumbar burst fractures, namely extent of height loss of the anterior wall of the fractured vertebra, level of spinal canal compromise by bone fragments and degree of widening of interspinous and interpedicular distance. It is the authors' opinion that the standardization of the main measurements in the evaluation of thoracolumbar burst fractures by radiological methods will provide the information required for a better interpretation of tests results and consequently aiding in the decision making about the most appropriate treatment. (author)

  13. Interobserver evaluation of TLICS system to treat thoracolumbar fractures

    Directory of Open Access Journals (Sweden)

    Bernardo José Moreira Chaves

    2015-06-01

    Full Text Available OBJECTIVE: To evaluate the interobserver agreement regarding the TLICS Classification (Thoracolumbar Injury Classification and Severity Score. Furthermore, evaluate the reliability, analyzing the correlation between the treatment indicated by TLICS system (surgical or conservative and the treatment indicated by each evaluator surgeon.METHODS: Imaging tests and clinical data of 22 patients with thoracolumbar fractures were analyzed by eight spine surgeons, and two main analyzes were performed: the first compared the interobserver agreement related to TLICS and the second compared the agreement between the treatment indicated by TLICS classification (surgical or conservative and treatment indicated by each surgeon - based on his personal experience and the preferred classification.RESULTS: Using the parameters of Landis and Koch for interpretation of Kappa value, the interobserver agreement of TLICS classification was considered moderate in our study (K=0.6. The agreement between the indications of treatment (surgical or conservative dictated by the classification and the indication of each surgeon was considered excellent, with kappa value of 0.89.CONCLUSION: We believe that the classification is a good tool for the evaluation and the treatment indication in thoracolumbar fractures.

  14. Clinical manifestations and significance of post-traumatic thoracolumbar syringomyelia

    Institute of Scientific and Technical Information of China (English)

    邱勇; 朱泽章; 吕锦瑜; 王斌; 李卫国; 朱丽华

    2004-01-01

    Objective: To analyze the pathogenic mechanism and the clinical significance of post-traumatic thoracolumbar syringomyelia through reviewing the clinical manifestations. Methods: The data of 15 patients (14 males and 1 female, aged from 28 to 56 years, with an average of 36 years) with post-traumatic syringomyelia treated in our hospital from December 1997 to February 2002 were studied retrospectively. Two patients suffered from T11 fractures, 7 from T12 fractures and 6 from L1 fractures. There were 12 patients with burst fractures and 3 with fracture dislocations. Anterior decompression, bone graft, bone fusion and internal fixation were made on 6 patients, posterior decompression, bone graft, bone fusion and internal fixation on 1 patient, and non-surgical treatment on 8 patients. Results: Syringomyelia of the patients was diagnosed accurately with magnetic resonance imaging at 0.5-4 years after the original thoracolumbar fracture. The cavern was round in 6 cases, elliptic in 6 cases, and irregular in 3 cases. The patients also suffered from pain (80%), myodynamia attenuation in lower extremities (66.7%), aggravated spasm (46.7%), sensation loss or hypesthesia (46.7%), decreased coordinate function of lower extremities (20%) and autonomic nerve symptom (6.7%).Conclusions: Post-traumatic thoracolumbar syringomyelia should be suspected if the patient has new neurological symptoms, such as myodynamia attenuation in lower extremities, after the neural function becomes stable for certain time.

  15. Crack resistance of austenitic pipes with circumferential through-wall cracks

    International Nuclear Information System (INIS)

    For monotonously increasing load the correct evaluation of the crack resistance properties of a structure is essential for safety analyses. Considerable attention has been given to the through-wall case, since this is generally believed to be the controlling case with regard to complete pipe failure. The maximum load conditions for circumferential crack growth in pipes under displacement-controlled loadings has been determined. The need for crack resistance curves, measured on circumferentially through-wall cracked straight pipes of austenitic stainless steel 316L under bending, is emphasized by the limitation in the data range on small specimens and by the differences in the procedures. To answer open questions and to improve calculational methods a joint fracture mechanics program is being performed by Electricite de France, Novatome and Siemens-Interatom. The working program contains experimental and theoretical investigations on the applicability of small-specimen data to real structures. 10 refs., 10 figs., 4 tabs

  16. Pedicle screw fixation combined with intervertebral bone grafting for the treatment of thoracolumbar fracture: a report of 24 cases

    Directory of Open Access Journals (Sweden)

    Chuan-lin DU

    2014-01-01

    Full Text Available Objective To explore the clinical effect of pedicle screw fixation combined with intervertebral bone grafting for the treatment of thoracolumbar fractures. Methods The clinical data of 24 cases of unstable and/or bursting thoracolumbar fractures treated with pedicle screw fixation and intervertebral bone grafting from July 2007 to July 2010 were analyzed retrospectively. The 24 patients (18 males and 6 females were aged from 24 to 61 years (mean 31.5 years, in whom 8 with fracture of T12, 9 of L1, 5 of L2, and 2 of L3 vertebral fracture. According to Denis classification, in 8 patients it was compression fracture, and in 16 patients it was burst fracture. According to American Spinal Injury Association (ASIA criteria, 2 patients were classified as grade C, 2 as grade D and 20 as grade E. All of the 24 patients received pedicle screw fixation combined with intervertebral bone grafting to reduce and fix the thoracolumbar fractures using pedicle screw-rod system, and 4 of them received posterior decompression. Results Twenty-two patients were followed-up from 12 to 24 months (mean 18 months. No obvious loss of vertebral height or posterior protuberance was found. There was no evidence of screw loosening or breakage, neither overdistraction of intervertebral space among 22 patients. The Cobb angle was corrected from 15-44 degrees (32.3±7.6 degrees, preoperatively to 0-9.6 degrees (6.6±2.4 degrees as observed at the time of last follow-up. Conclusion Pedicle screw fixation combined with intervertebral bone grafting could reconstruct the mechanical structure of anterior and middle spinal columns, obtain effective intervertebral height and bone union, and long-term spine stability. DOI: 10.11855/j.issn.0577-7402.2013.12.11

  17. Fracture Toughness Derived from Small Circumferentially Cracked Bars

    International Nuclear Information System (INIS)

    Small circumferentially Cracked Round Bars (CRB) are used to derive the fracture toughness of reactor pressure vessel steels. This cylindrical geometry is of practical interest for the nuclear industry as it requires only a small amount of irradiated material and as it is easy to test on a tensile machine. This paper describes an experimental procedure to obtain fracture toughness measurements from CRB with a diameter of 10 mm. Emphasis is on crack growth monitoring during rotating bending fatigue precracking, on the formulae used to analyse the load displacement trace of a fracture toughness test and on the correction to be applied to take the loss of constraint into account. Experiments show that the method has the potential to derive fracture toughness values from the lower shelf to the lower transition region. Finite element analysis shows that the constraint of this geometry is generally lower than for bend specimens but is higher at higher load levels, allowing comparison with toughness data valid according to prevailing standards

  18. Effect of circumferential wave number on stability of suspension flow

    Directory of Open Access Journals (Sweden)

    Wang Feng-Hui

    2014-01-01

    Full Text Available The linear stability analysis is carried out for the suspension flow of spherical particles between a rotating inner cylinder and a stationary concentric outer cylinder. The mass conservation equation and Navier-Stokes equation are applied to the continuous fluid phase and the particle phase. Results of stability analysis show that the increase of wave number in the circumferential direction attenuates the effect of the axial wave number on the amplification factor. The ratio of particle density to fluid density increasing above 0.1 amplifies the flow instability, while it can be weakened with higher circumferential direction wave number. Effect of the critical Taylor number on the amplification factor is reduced by increasing the circumferential direction wave number. The flow stability is affected by the geometry of flow field (the radius ratio at non-zero circumferential direction wave numbers.

  19. Radiologic abnormalities of the thoraco-lumbar spine in athletes

    International Nuclear Information System (INIS)

    A radiologic study of the thoraco-lumbar spine was performed in 143 (117 male and 26 female) athletes (wrestlers, gymnasts, soccer players and tennis players), aged 14 to 25 years and 30 male nonathletes, aged 19 to 25 years. Film interpretation was made after mixing the films from all groups and without knowledge of the individual's identity. Various types of radiologic abnormalities occured in both athletes and non-athletes but were more common among athletes, especially male-gymnasts and wrestlers. Abnormalities of the vertebral ring apophysis occurred exclusively in athletes. Combinations of different types of abnormalities were most common in male gymnasts and wrestlers. (orig.)

  20. Treatment of Thoracolumbar Spinal Infections through Anterolateral Approaches Using Expandable Titanium Mesh Cage for Spine Reconstruction

    Directory of Open Access Journals (Sweden)

    Tarantino Roberto

    2012-01-01

    Full Text Available Pyogenic vertebral osteomyelitis (PVO is still a rare pathology. However, its incidence is on the rise. This is due to an increasing population with predisposing factors. Also, the availability of more effective diagnostic tools has brought it increasingly to the surgeon’s attention. In this study the patients were treated in the Neurosurgery Division of the Department of Neurological Sciences and Psychiatry of the Sapienza University of Rome, between 2001 and 2009. They had thoracolumbar pyogenic spondylitis. This study was undertaken in order to identify the correct diagnostic and therapeutic treatment needed in such cases. From the cases studied here, it is evident that spinal infections can be extremely insidious and that diagnosis tends to be reached late. Surgery, along with the antibiotic treatment, allows for eradication of the causes of the pathology by the reclamation of the affected region. Surgery is also fundamental in helping to recover vital functions and in restoring as much as possible the correct curvature of the rachises. The use of an anterolateral approach is dictated by the necessity of obtaining 360° stability as well as by the need to clear away extensive infections, which are not always reachable using a posterior approach.

  1. Pediculectomy for the treatment of thoracolumbar disk disease

    Directory of Open Access Journals (Sweden)

    Leonardo Martins Leal

    2011-06-01

    Full Text Available Thoracolumbar disk disease is a condition associated with spinal cord compression that leads to the extrusion of the nucleus pulposus of an intervertebral disk. It can cause mild pain to very severe symptoms including complete paralysis of the pelvic limbs. The treatment for this disease depends on the location and severity of the compression. The objective of this study was to use pediculectomy surgery technique, for spinal decompression, on a seven-year-old female dog that was a mixed breed, suffered from pelvic limb paresis, and was diagnosed with dorsolateral thoracolumbar disk disease. A disk fenestration was also performed in the area to prevent the recurrence of the symtoms. The pediculectomy technique involves creating a slot in the lateral area of the vertebras to preserve the articular facets. Thirty days after the surgery the patient was walking normally. The pediculectomy technique is a good surgical option because it promotes decompression, and extruded material can be removed, which leads to less instability decreases the chance of vertebral dislocation and allows disk fenestration to be performed during the same surgical period. Pediculectomy was effective in the treatment of this patient.

  2. Biomechanical Analysis of Pedicle Screw Fixation for Thoracolumbar Burst Fractures.

    Science.gov (United States)

    McDonnell, Matthew; Shah, Kalpit N; Paller, David J; Thakur, Nikhil A; Koruprolu, Sarath; Palumbo, Mark A; Daniels, Alan H

    2016-05-01

    Treatment of unstable thoracolumbar burst fractures remains controversial. Long-segment pedicle screw constructs may be stiffer and impart greater forces on adjacent segments compared with short-segment constructs, which may affect clinical performance and long-term out come. The purpose of this study was to biomechanically evaluate long-segment posterior pedicle screw fixation (LSPF) vs short-segment posterior pedicle screw fixation (SSPF) for unstable burst fractures. Six unembalmed human thoracolumbar spine specimens (T10-L4) were used. Following intact testing, a simulated L1 burst fracture was created and sequentially stabilized using 5.5-mm titanium polyaxial pedicle screws and rods for 4 different constructs: SSPF (1 level above and below), SSPF+L1 (pedicle screw at fractured level), LSPF (2 levels above and below), and LSPF+L1 (pedicle screw at fractured level). Each fixation construct was tested in flexion-extension, lateral bending, and axial rotation; range of motion was also recorded. Two-way repeated-measures analysis of variance was performed to identify differences between treatment groups and functional noninstrumented spine. Short-segment posterior pedicle screw fixation did not achieve stability seen in an intact spine (P.1). Long-segment posterior pedicle screw fixation constructs were not associated with increased adjacent segment motion. Al though the sample size of 6 specimens was small, this study may help guide clinical decisions regarding burst fracture stabilization. [Orthopedics. 2016; 39(3):e514-e518.]. PMID:27135451

  3. Surgical Treatment for Giant Cell Tumor of the Thoracolumbar Spine

    Directory of Open Access Journals (Sweden)

    Shih-Chieh Yang

    2006-02-01

    Full Text Available Background: Giant cell tumor (GCT of the bone has historically been regarded as anextremely unpredictable bone tumor. The anatomical characteristics of spinalGCT still present challenges to surgeons. Controversy remains regarding theproper treatment of patients with grade III tumors.Methods: Eleven patients with grade III GCT of the thoracolumbar spine were treatedbetween 1992 and 2002 at a medical center by the authors. Three patientswere initially treated at other institutions. Adjuvant radiotherapy wasemployed for local recurrence in these three patients. The other eight patientswere initially treated with marginal excision. The site, size, and extent ofeach lesion dictated the surgical approach.Results: Five patients had tumor recurrence. One patient, who received radiotherapy,had local relapse with malignant transformation and finally died due to disease-related complications. One patient had a recurrent tumor with multiplemetastases throughout the lung. Neurological status, measured using theAmerican Spinal Injury Association scale, of one patient was worse afterundergoing the procedure than preoperatively and three patients showedimprovement. The other seven patients were classified as with the samegrade postoperatively.Conclusion: Wide excision of GCT of the thoracolumbar spine is difficult and there is arisk of neurological deficit and spinal instability. Meticulous marginal excisionwith associated reconstruction may obtain good local control and preservefunctional spine. Early detection of recurrent GCT during intensive follow-up can allow for treatment using en bloc excision which has achievedfavorable prognoses.

  4. MR Imaging of Supraspinous Ligament Injury in the Thoracolumbar Spine

    International Nuclear Information System (INIS)

    We wanted to evaluate the MRI features and their diagnostic accuracy for SSL injury in the thoracolumbar spine. From December 2003 to June 2006, among 42 surgically treated patients with spinal fracture, the 35 patients who underwent MRI and who were surgically evaluated for SSL injury were included in this study. The sagittal MR images were evaluated for the presence of SSL injury and its level, location and distraction gap, the level and compression ratio of the fractured body, and the presence of ISL or yellow ligament injury and posterior osseous fracture. The sensitivity, specificity and accuracy of MRI were calculated. The distraction gap of the SSL and the compression ratio of the fractured body or posterior osseous fracture were statistically analyzed. Thirty-one among the 33 patients with surgically confirmed SSL injury were diagnosed on MRI. SSL injury was mostly seen at the thoracolumbar junction and near the upper spinous process. The mean distraction gap was 4.3 mm. The level of the fractured body was most commonly in the lower vertebra of the injured SSL level and the mean compression ratio was 21.8%. Combined SSL, ISL and yellow ligament injury were mostly seen. The sensitivity, specificity and accuracy were 93.9%, 50% and 91.4%, respectively. There was a statistically significant difference of the distraction gap of the injured SSL depending on the presence of posterior osseous fracture. MRI is an accurate modality for evaluating SSL injury and the associated findings

  5. Four year experience with the AO Anterior Thoracolumbar Locking Plate.

    Science.gov (United States)

    Thalgott, J S; Kabins, M B; Timlin, M; Fritts, K; Giuffre, J M

    1997-05-01

    For decades spinal surgeons have attempted to design simple, single stage anterior internal fixation systems for the thoracic and lumbar spine. Early devices presented both biomechanical and technical problems. The AO Anterior Thoracolumbar Locking Plate (ATLP) was designed to solve some of the problems encountered with early anterior instrumentation. The ATLP system is constructed in Commercially Pure titanium. It is a low profile device indicated for use for unstable burst fractures in the anterior column; metastatic tumor management; and degenerative diseases of the thoracolumbar spine between levels T10 and L5. Implantation of the device involves direct anterior decompression with sagittal reduction and corpectomy. This is followed by grafting reconstruction, and plate fixation. This device has been implanted in 25 patients with an average follow-up of 38 months. There were five (5) broken screws in three (3) patients, and no broken plates. Implant related postoperative complications included two misplaced screws. Preliminary results indicate that the ATLP system seems to be a safe, low profile, MRI/CT compatible device that provides definitive single stage fixation of the anterior spinal column. PMID:9160452

  6. GUIDED CIRCUMFERENTIAL WAVES IN DOUBLE-WALLED CARBON NANOTUBES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A model of guided circumferential waves propagating in double-walled carbon nanotubes is built by the theory of wave propagation in continuum mechanics, while the van der Waals force between the inner and outer nanotube has been taken into account in the model. The dispersion curves of the guided circumferential wave propagation are studied, and some dispersion characteristics are illustrated by comparing with those of single-walled carbon nanotubes. It is found that in double-walled carbon nanotubes, the guided circumferential waves will propagate in more dispersive ways. More interactions between neighboring wave modes may take place. In particular, it has been found that a couple of wave modes may disappear at a certain frequency and that, while a couple of wave modes disappear, another new couple of wave modes are excited at the same wave number.

  7. Circumferential gap propagation in an anisotropic elastic bacterial sacculus

    CERN Document Server

    Taneja, Swadhin; Rutenberg, Andrew D

    2013-01-01

    We have modelled stress concentration around small gaps in anisotropic elastic sheets, corresponding to the peptidoglycan sacculus of bacterial cells, under loading corresponding to the effects of turgor pressure in rod-shaped bacteria. We find that under normal conditions the stress concentration is insufficient to mechanically rupture bacteria, even for gaps up to a micron in length. We then explored the effects of stress-dependent smart-autolysins, as hypothesised by Arthur L Koch [Advances in Microbial Physiology 24, 301 (1983); Research in Microbiology 141, 529 (1990)]. We show that the measured anisotropic elasticity of the PG sacculus can lead to stable circumferential propagation of small gaps in the sacculus. This is consistent with the recent observation of circumferential propagation of PG-associated MreB patches in rod-shaped bacteria. We also find a bistable regime of both circumferential and axial gap propagation, which agrees with behavior reported in cytoskeletal mutants of B. subtilis. We con...

  8. Structural and leakage integrity of tubes affected by circumferential cracking

    Energy Technology Data Exchange (ETDEWEB)

    Hernalsteen, P. [TRACTEBEL, Brussels (Belgium)

    1997-02-01

    In this paper the author deals with the notion that circumferential cracks are generally considered unacceptable. He argues for the need to differentiate two facets of such cracks: the issue of the size and growth rate of a crack; and the issue of the structural strength and leakage potential of the tube in the presence of the crack. In this paper the author tries to show that the second point is not a major concern for such cracks. The paper presents data on the structural strength or burst pressure characteristics of steam generator tubes derived from models and data bases of experimental work. He also presents a leak rate model, and compares the performance of circumferential and axial cracks as far as burst strength and leak rate. The final conclusion is that subject to improvement in NDE capabilities (sizing, detection, growth), that Steam Generator Defect Specific Management can be used to allow circumferentially degraded tubes to remain in service.

  9. Circumferential fusion improves outcome in comparison with instrumented posterolateral fusion

    DEFF Research Database (Denmark)

    Videbaek, Tina S; Christensen, Finn B; Soegaard, Rikke;

    2006-01-01

    STUDY DESIGN: Prospective randomized clinical study with a 5- to 9-year follow-up period. OBJECTIVE: The aim of the present study was to analyze the long-term outcome with respect to functional disability, pain, and general health of patients treated by means of circumferential lumbar fusion...... in comparison with those treated by means of instrumented posterolateral lumbar fusion. SUMMARY OF BACKGROUND DATA: Circumferential fusion has become a common procedure in lumbar spinal fusion both as a primary and salvage procedure. However, the claimed advantages of circumferential fusion over conventional...... posterolateral fusion lack scientific documentation. (The primary report with a 2-year follow-up has been published in Spine in 2002.) METHODS: From April 1996 to November 1999, a total of 148 patients (mean age, 45 years) with severe chronic low back pain were randomly selected for either posterolateral lumbar...

  10. Long-term functional results after short-segment pedicle fixation of thoracolumbar fractures

    DEFF Research Database (Denmark)

    Mølmer, Michael; Gehrchen, Poul Martin; Dahl, Benny

    2013-01-01

    A retrospective study to assess the health-related quality of life in patients undergoing posterior fixation of thoracolumbar fractures, and to compare the outcome with norm scores and HRQL in patients undergoing surgical treatment for degenerative conditions of the spine.......A retrospective study to assess the health-related quality of life in patients undergoing posterior fixation of thoracolumbar fractures, and to compare the outcome with norm scores and HRQL in patients undergoing surgical treatment for degenerative conditions of the spine....

  11. Treatment of acute thoracolumbar burst fractures with kyphoplasty and short pedicle screw fixation: Transpedicular intracorporeal grafting with calcium phosphate: A prospective study

    Directory of Open Access Journals (Sweden)

    Korovessis Panagiotis

    2007-01-01

    Full Text Available Background: In the surgical treatment of thoracolumbar fractures, the major problem after posterior correction and transpedicular instrumentation is failure to support the anterior spinal column, leading to loss of correction and instrumentation failure with associated complaints. We conducted this prospective study to evaluate the outcome of the treatment of acute thoracolumbar burst fractures by transpedicular balloon kyphoplasty, grafting with calcium phosphate cement and short pedicle screw fixation plus fusion. Materials and Methods : Twenty-three consecutive patients of thoracolumbar (T 9 to L 4 burst fracture with or without neurologic deficit with an average age of 43 years, were included in this prospective study. Twenty-one from the 23 patients had single burst fracture while the remaining two patients had a burst fracture and additionally an adjacent A1-type fracture. On admission six (26% out of 23 patients had neurological deficit (five incomplete, one complete. Bilateral transpedicular balloon kyphoplasty with liquid calcium phosphate to reduce segmental kyphosis and restore vertebral body height and short (three vertebrae pedicle screw instrumentation with posterolateral fusion was performed. Gardner kyphosis angle, anterior and posterior vertebral body height ratio and spinal canal encroachment were calculated pre- to postoperatively. Results : All 23 patients were operated within two days after admission and were followed for at least 12 months after index surgery. Operating time and blood loss averaged 45 min and 60 cc respectively. The five patients with incomplete neurological lesions improved by at least one ASIA grade, while no neurological deterioration was observed in any case. The VAS and SF-36 (Role physical and Bodily pain domains were significantly improved postoperatively. Overall sagittal alignment was improved from an average preoperative 16° to one degree kyphosis at final follow-up observation. The anterior

  12. Reduced thoracolumbar fascia shear strain in human chronic low back pain

    Directory of Open Access Journals (Sweden)

    Konofagou Elisa E

    2011-09-01

    Full Text Available Abstract Background The role played by the thoracolumbar fascia in chronic low back pain (LBP is poorly understood. The thoracolumbar fascia is composed of dense connective tissue layers separated by layers of loose connective tissue that normally allow the dense layers to glide past one another during trunk motion. The goal of this study was to quantify shear plane motion within the thoracolumbar fascia using ultrasound elasticity imaging in human subjects with and without chronic low back pain (LBP. Methods We tested 121 human subjects, 50 without LBP and 71 with LBP of greater than 12 months duration. In each subject, an ultrasound cine-recording was acquired on the right and left sides of the back during passive trunk flexion using a motorized articulated table with the hinge point of the table at L4-5 and the ultrasound probe located longitudinally 2 cm lateral to the midline at the level of the L2-3 interspace. Tissue displacement within the thoracolumbar fascia was calculated using cross correlation techniques and shear strain was derived from this displacement data. Additional measures included standard range of motion and physical performance evaluations as well as ultrasound measurement of perimuscular connective tissue thickness and echogenicity. Results Thoracolumbar fascia shear strain was reduced in the LBP group compared with the No-LBP group (56.4% ± 3.1% vs. 70.2% ± 3.6% respectively, p Conclusion Thoracolumbar fascia shear strain was ~20% lower in human subjects with chronic low back pain. This reduction of shear plane motion may be due to abnormal trunk movement patterns and/or intrinsic connective tissue pathology. There appears to be some sex-related differences in thoracolumbar fascia shear strain that may also play a role in altered connective tissue function.

  13. First performance evaluation of software for automatic segmentation, labeling and reformation of anatomical aligned axial images of the thoracolumbar spine at CT

    International Nuclear Information System (INIS)

    Highlights: •Automatic segmentation and labeling of the thoracolumbar spine. •Automatically generated double-angulated and aligned axial images of spine segments. •High grade of accurateness for the symmetric depiction of anatomical structures. •Time-saving and may improve workflow in daily practice. -- Abstract: Objectives: To evaluate software for automatic segmentation, labeling and reformation of anatomical aligned axial images of the thoracolumbar spine on CT in terms of accuracy, potential for time savings and workflow improvement. Material and methods: 77 patients (28 women, 49 men, mean age 65.3 ± 14.4 years) with known or suspected spinal disorders (degenerative spine disease n = 32; disc herniation n = 36; traumatic vertebral fractures n = 9) underwent 64-slice MDCT with thin-slab reconstruction. Time for automatic labeling of the thoracolumbar spine and reconstruction of double-angulated axial images of the pathological vertebrae was compared with manually performed reconstruction of anatomical aligned axial images. Reformatted images of both reconstruction methods were assessed by two observers regarding accuracy of symmetric depiction of anatomical structures. Results: In 33 cases double-angulated axial images were created in 1 vertebra, in 28 cases in 2 vertebrae and in 16 cases in 3 vertebrae. Correct automatic labeling was achieved in 72 of 77 patients (93.5%). Errors could be manually corrected in 4 cases. Automatic labeling required 1 min in average. In cases where anatomical aligned axial images of 1 vertebra were created, reconstructions made by hand were significantly faster (p < 0.05). Automatic reconstruction was time-saving in cases of 2 and more vertebrae (p < 0.05). Both reconstruction methods revealed good image quality with excellent inter-observer agreement. Conclusion: The evaluated software for automatic labeling and anatomically aligned, double-angulated axial image reconstruction of the thoracolumbar spine on CT is time

  14. First performance evaluation of software for automatic segmentation, labeling and reformation of anatomical aligned axial images of the thoracolumbar spine at CT

    Energy Technology Data Exchange (ETDEWEB)

    Scholtz, Jan-Erik, E-mail: janerikscholtz@gmail.com; Wichmann, Julian L.; Kaup, Moritz; Fischer, Sebastian; Kerl, J. Matthias; Lehnert, Thomas; Vogl, Thomas J.; Bauer, Ralf W.

    2015-03-15

    Highlights: •Automatic segmentation and labeling of the thoracolumbar spine. •Automatically generated double-angulated and aligned axial images of spine segments. •High grade of accurateness for the symmetric depiction of anatomical structures. •Time-saving and may improve workflow in daily practice. -- Abstract: Objectives: To evaluate software for automatic segmentation, labeling and reformation of anatomical aligned axial images of the thoracolumbar spine on CT in terms of accuracy, potential for time savings and workflow improvement. Material and methods: 77 patients (28 women, 49 men, mean age 65.3 ± 14.4 years) with known or suspected spinal disorders (degenerative spine disease n = 32; disc herniation n = 36; traumatic vertebral fractures n = 9) underwent 64-slice MDCT with thin-slab reconstruction. Time for automatic labeling of the thoracolumbar spine and reconstruction of double-angulated axial images of the pathological vertebrae was compared with manually performed reconstruction of anatomical aligned axial images. Reformatted images of both reconstruction methods were assessed by two observers regarding accuracy of symmetric depiction of anatomical structures. Results: In 33 cases double-angulated axial images were created in 1 vertebra, in 28 cases in 2 vertebrae and in 16 cases in 3 vertebrae. Correct automatic labeling was achieved in 72 of 77 patients (93.5%). Errors could be manually corrected in 4 cases. Automatic labeling required 1 min in average. In cases where anatomical aligned axial images of 1 vertebra were created, reconstructions made by hand were significantly faster (p < 0.05). Automatic reconstruction was time-saving in cases of 2 and more vertebrae (p < 0.05). Both reconstruction methods revealed good image quality with excellent inter-observer agreement. Conclusion: The evaluated software for automatic labeling and anatomically aligned, double-angulated axial image reconstruction of the thoracolumbar spine on CT is time

  15. Circumferential wires as a supplement to intramedullary nailing in unstable trochanteric hip fractures

    DEFF Research Database (Denmark)

    Ban, Ilija; Birkelund, Lasse; Palm, Henrik;

    2012-01-01

    Fixation of unstable trochanteric fractures is challenging. Application of a circumferential wire may facilitate bone contact and avoid postoperative fracture displacement. However, the use of circumferential wires remains controversial due to possible disturbance of the blood supply to the under...

  16. Nonlinear Local Bending Response and Bulging Factors for Longitudinal and Circumferential Cracks in Pressurized Cylindrical Shells

    Science.gov (United States)

    Young, Richard D.; Rose, Cheryl A.; Starnes, James H., Jr.

    2000-01-01

    Results of a geometrically nonlinear finite element parametric study to determine curvature correction factors or bulging factors that account for increased stresses due to curvature for longitudinal and circumferential cracks in unstiffened pressurized cylindrical shells are presented. Geometric parameters varied in the study include the shell radius, the shell wall thickness, and the crack length. The major results are presented in the form of contour plots of the bulging factor as a function of two nondimensional parameters: the shell curvature parameter, lambda, which is a function of the shell geometry, Poisson's ratio, and the crack length; and a loading parameter, eta, which is a function of the shell geometry, material properties, and the applied internal pressure. These plots identify the ranges of the shell curvature and loading parameters for which the effects of geometric nonlinearity are significant. Simple empirical expressions for the bulging factor are then derived from the numerical results and shown to predict accurately the nonlinear response of shells with longitudinal and circumferential cracks. The numerical results are also compared with analytical solutions based on linear shallow shell theory for thin shells, and with some other semi-empirical solutions from the literature, and limitations on the use of these other expressions are suggested.

  17. Short segmental pedicle screw fixation combined with percutaneous vertebroplasty in treatment of nonadjacent thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    HE Qing-yi; XU Jian-zhong

    2009-01-01

    To evaluate the short-term outcomes of short segmental pedicle screw fixation combined with per-cutaneous vertebroplasty in treatment of nonadjacent tho-racolumbar fractures. Methods: Twenty patients who suffered from nonadja-cent thoracolumbar fractures were treated by short segmental pedicle screw fixation for burst fracture and by percutane-ous vertebroplasty for compression fracture. X-rays, CT and MRI scans were conducted using the same protocol before and after surgery and during follow-up. Pre- and post-operative American Spinal Injury Association (ASIA) grades, fusion of fracture sites, visual analog scale (VAS) of back pain, and Oswestry disability index (ODI) were accessed. Results: All patients were followed up for an average period of 12 months. The sagittal profile of the thoracolum-bar spine was restored satisfactorily. No patient had neuro-logic deterioration after surgery, and 9 patients with incom-plete lesions improved postoperatively by at least one ASIA grade. The fusion rate was 100%. The average VAS of back pain was 7.6 preoperatively and 3.2 postoperatively. The average ODI was 72.5 preoperatively and 35.5 postoperatively. Conclusions: Short segmental pedicle screw fixation combined with percutaneous vertebroplasty in treatment of nonadjacent thoracolumbar fractures exhibits such advan-tages as preserving functional segment units, reliable fixation, good neurologic recovery and early mobilization and, therefore, is suitable for treating nonadjacent thora-columbar fractures.

  18. MANAGEMENT OF UNSTABLE THORACOLUMBAR FRACTURES BY POSTERIOR INSTRUMENTATION WITH TRANSPEDICULAR PEDICLE SCREWS AND CONNECTING RODS

    Directory of Open Access Journals (Sweden)

    Jayaram

    2015-09-01

    Full Text Available OBJECTIVE: To evaluate the use of pedicle screw and rod fixation in post - traumatic unstable thoracolumbar Spine fractures. METHODS: Thirty six patients with posttraumatic instability of thoracolumbar were included in the study. Thoracolumbar injury severity scoring was used to assess spinal instability. All patients underwent open reduction and internal fixation by posterior approach. Pedicles were localized using detailed anatomical landmarks and intraoperative imaging. The neurological status of the patients was assessed using ASIA grading and any other complications were noted up to 6 months. RESULTS: There were 36 patients with unstable thoracolumbar junction injuries who were managed with pedicle screws and rods. M ales were more affected (M: F ratio was 8: 1. AO type A was the commonest. The most common level was L1. None of the patients deteriorated after surgery. 27 patients with incomplete cord injury showed at least one frankel grade improvement. 8 patients with complete cord injury showed no improvement. The mean kyphotic angle by Cobb’s method was 20.8° on admission, 4.6° post operatively and 6.1° at latest follow - up . Average anterior vertebral body height at the time of admission was 52%, post op was 85% and at final follow up was 80%. T here was 1 case of malpositiong of screw and 5 patients developed bed sores. CONCLUSION: Pedicle screw fixation is a useful choice for thoracolumbar junction injuries for achieving reduction and stability, without affecting extra motion segments.

  19. Circumferential buckling instability of a growing cylindrical tube

    KAUST Repository

    Moulton, D.E.

    2011-03-01

    A cylindrical elastic tube under uniform radial external pressure will buckle circumferentially to a non-circular cross-section at a critical pressure. The buckling represents an instability of the inner or outer edge of the tube. This is a common phenomenon in biological tissues, where it is referred to as mucosal folding. Here, we investigate this buckling instability in a growing elastic tube. A change in thickness due to growth can have a dramatic impact on circumferential buckling, both in the critical pressure and the buckling pattern. We consider both single- and bi-layer tubes and multiple boundary conditions. We highlight the competition between geometric effects, i.e. the change in tube dimensions, and mechanical effects, i.e. the effect of residual stress, due to differential growth. This competition can lead to non-intuitive results, such as a tube growing to be thinner and yet buckle at a higher pressure. © 2011 Elsevier Ltd. All rights reserved.

  20. Fracture toughness evaluation of circumferentially-cracked round bars

    International Nuclear Information System (INIS)

    The measure of the fracture toughness of a circumferentially-cracked round bar is generally performed through approximate formulae. Comparison of existing formulae to finite element results does not always show good agreement. Therefore an eta factor is introduced in order to improve the existing analytical formula. The axisymmetrical geometry is generally considered to be a high constrained geometry. Finite element calculations are performed to verify and quantify the constraint relative to the three point bending configuration (precracked Charpy)

  1. Ground and microgravity results of a circumferentially microgrooved capillary evaporator

    International Nuclear Information System (INIS)

    A circumferentially microgrooved capillary evaporator is here proposed as a reliable alternative for ground and spacecraft thermal control system applications. In this paper, experimental results concerning the start-up and thermal behavior of a capillary evaporator at steady state operation are presented. A capillary pumped loop was developed and tested at ground and microgravity conditions, using deionized water as the working fluid. The capillary evaporator has internally machined circumferential grooves with an average opening of 33 μm opening at 215 μm step into a 19.05 mm (3/4 in) diameter aluminum tube. The corresponding capillary pumping pressure is about 1.5 kPa. In both tests, power inputs up to 10 W (4.55 kW/m2) were successfully applied to the external surface of the evaporator, showing good performance under ground and microgravity conditions. The capillary evaporator as proposed proved to be a reliable alternative for industrial and space applications. - Highlights: • Circumferentially grooved capillary evaporators as alternative for thermal control. • Successful start-up operation at ground and microgravity conditions. • Successful steady state operation at ground and microgravity conditions. • Easy repriming in case of dry-out

  2. Value of multidetector spiral CT in diagnosis of acute thoracolumbar spinal fracture and fracture-dislocation

    Institute of Scientific and Technical Information of China (English)

    龚静山; 徐坚民

    2004-01-01

    Objective:To investigate the diagnostic value of multidetector spiral CT (MSCT) in acute thoracolumbar spinal fracture and fracture-dislocation.Methods: CT imaging files of 152 consecutive traumatic patients with thoracolumbar fractures were retrospectively reviewed. MSCT scannings were performed with a collimation of 3-5 mm and a pitch of 5.5. The postprocessing included sagittal and coronal multiplannar reconstruction, and 3-D reconstruction.Result: There were 88 cases of compression fracture, 54 cases of burst fracture and 10 cases of fracasdislocation. Transverse images of MSCT could visualize all fractures directly and determine whether spinal canal was intact. Postprocessing image was helpful in depicting the displacement of fragment and orientation of dislocation.Conclusions: MSCT plays an important role in diagnosis and management of acute thoracolumbar spinal fracture and fracture-dislocation.

  3. Imaging evaluation of traumatic thoracolumbar spine injuries: Radiological review.

    Science.gov (United States)

    Gamanagatti, Shivanand; Rathinam, Deepak; Rangarajan, Krithika; Kumar, Atin; Farooque, Kamran; Sharma, Vijay

    2015-09-28

    Spine fractures account for a large portion of musculoskeletal injuries worldwide. A classification of spine fractures is necessary in order to develop a common language for treatment indications and outcomes. Several classification systems have been developed based on injury anatomy or mechanisms of action, but they have demonstrated poor reliability, have yielded little prognostic information, and have not been widely used. For this reason, the Arbeitsgemeinschaftfür Osteosynthesefragen (AO) committee has classified thorocolumbar spine injuries based on the pathomorphological criteria into3 types (A: Compression; B: Distraction; C: Axial torque and rotational deformity). Each of these types is further divided into 3 groups and 3 subgroups reflecting progressive scale of morphological damage and the degree of instability. Because of its highly detailed sub classifications, the AO system has shown limited interobserver variability. It is similar to its predecessors in that it does not incorporate the patient's neurologic status.The need for a reliable, reproducible, clinically relevant, prognostic classification system with an optimal balance of ease of use and detail of injury description contributed to the development of a new classification system, the thoracolumbar injury classification and severity score (TLICS). The TLICS defines injury based on three clinical characteristics: injury morphology, integrity of the posterior ligamentous complex, and neurologic status of the patient. The severity score offers prognostic information and is helpful in decision making about surgical vs nonsurgical management. PMID:26435776

  4. Imaging evaluation of traumatic thoracolumbar spine injuries: Radiological review

    Institute of Scientific and Technical Information of China (English)

    Shivanand; Gamanagatti; Deepak; Rathinam; Krithika; Rangarajan; Atin; Kumar; Kamran; Farooque; Vijay; Sharma

    2015-01-01

    Spine fractures account for a large portion of musculoskeletal injuries worldwide. A classification of spine fractures is necessary in order to develop a common language for treatment indications and outcomes. Several classification systems have been developed based on injury anatomy or mechanisms of action, but they have demonstrated poor reliability, have yielded little prognostic information, and have not been widely used. For this reason, the Arbeitsgemeinschaftfür Osteosynthesefragen(AO) committee has classified thorocolumbar spine injuries based on the pathomorphological criteria into3 types(A: Compression; B: Distraction; C: Axial torque and rotational deformity). Each of these types is further divided into 3 groups and 3 subgroups reflecting progressive scale of morphological damage and the degree of instability. Because of its highly detailed sub classifications, the AO system has shown limited interobserver variability. It is similar to its predecessors in that it does not incorporate the patient’s neurologic status.The need for a reliable, reproducible, clinically relevant, prognostic classification system with an optimal balance of ease of use and detail of injury description contributed to the development of a new classification system, the thoracolumbar injury classification and severity score(TLICS). The TLICS defines injury based on three clinical characteristics: injury morphology, integrity of the posterior ligamentous complex, and neurologic status of the patient. The severity score offers prognostic information and is helpful in decision making about surgical vs nonsurgical management.

  5. Formative mechanism of intracanal fracture fragments in thoracolumbar burst fractures: a finite element study

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhi-li; ZHU Rui; LI Shan-zhu; YU Yan; WANG Jian-jie; JIA Yong-wei; CHEN Bo

    2013-01-01

    Background Thoracolumbar burst fracture is a common clinical injury,and the fracture mechanism is still controversial.The aim of this research was to study the formation of intracanal fracture fragments in thoracolumbar burst fractures and to provide information for the prevention of thoracolumbar bursts fractures and reduction of damage to the nervous system.Methods A nonlinear three-dimensional finite element model of T11-L3 segments was established,and the injury processes of thoracolumbar bursts were simulated.The intact finite element model and the finite element model after the superior articular were impacted by 100 J of energy in different directions.The distribution and variation of stress in the superior posterior region of the L1 vertebral body were analyzed.Abaqus 6.9 explicit dynamic solver was used as finite element software in calculations.Results A three-dimensional nonlinear finite element model of the thoracolumbar spine was created.In the intact model,stress was concentrated in the superior posterior region of the L1 vertebral body.The stress peak was a maximum for the extension impact load and a minimum for the flexion impact load.The stress peak and contact force in the facet joint had close correlation with time.The stress peak disappeared after excision of the superior articular process.Conclusions The three-dimensional nonlinear finite element model was suitable for dynamic analysis.The contact force in the facet joint,which can be transferred to the superior posterior vertebral body,may explain the spinal canal fragment in thoracolumbar burst fractures.

  6. Posterior short-segment fixation using ligamentotaxis for the thoracolumbar vertebral body fractures. Multicenter study

    International Nuclear Information System (INIS)

    Described are the operative technique for the thoracolumbar vertebral body fractures and their imaging evaluation by X-radiography and CT. The radiological technique of surgery involves the one level above-one level below screw fixation at the injured vertebra, taxis of kyphotic abnormality with screws and distraction with a rod, and ligamentotaxis after fulfillment of hydroxyl-apatite block in the formed hole at the pedicle of arch. Subjects are 74 patients (M 45/F 29; 14-78 years old; fracture at T11-12, 7 cases, L1-5, 67; A1 fracture 9 cases, A2, 8, A3, 55, and C1, 2) (not including the fragility fracture) of 5 hospitals, of whose 40 cases are followed up for 9-24 months after operation. Operation with Universal Spine System (Synthes) is conducted 1-31 days post injury. Following parameters are obtained in images before (at injury) and immediately after or after operation: Vertebral kyphotic angles, and heights of injured bone anterior/posterior (a/p) for calculation of wedge-shaped deformation rate (WDR) are measured in the lateral radiograph; and minimal diameters of a/p injured vertebral canal for canal constrictive rate, in CT. The mean kyphotic angle is found to be 8.5 deg at injury and 0.2 deg immediately after surgery, and WDR, 33.3% and 12.9%: significant corrections found. The canal constriction 57% at injury is significantly improved to 39% after operation. From aspect of calculated AIC (Akaike Information Criteria) on WDR, the operation is considered to have to be done within 7 disease days in average. (K.T.)

  7. Biomechanics of Thoracolumbar Burst and Chance-Type Fractures during Fall from Height

    OpenAIRE

    Ivancic, Paul C.

    2014-01-01

    Study Design In vitro biomechanical study. Objective To investigate the biomechanics of thoracolumbar burst and Chance-type fractures during fall from height. Methods Our model consisted of a three-vertebra human thoracolumbar specimen (n = 4) stabilized with muscle force replication and mounted within an impact dummy. Each specimen was subjected to a single fall from an average height of 2.1 m with average velocity at impact of 6.4 m/s. Biomechanical responses were determined using impact lo...

  8. Vertebral stabilisation and selective decompression for the management of triple thoracolumbar disc protrusions.

    Science.gov (United States)

    McKee, W M; Downes, C J

    2008-10-01

    Triple adjacent thoracolumbar disc protrusions causing moderate to severe spinal cord compression were diagnosed by magnetic resonance imaging in two German shepherd dogs with marked paraparesis and pelvic limb ataxia. Both cases were managed by selective hemilaminectomy, partial annulectomy and bilateral quadruple vertebral body stabilisation using novel canine locking fixation plates (SOP). The stabilisation of multiple vertebrae in the thoracolumbar spine was possible because the plates could be contoured with six degrees of freedom. Spinal pain resolved and neurological function improved in both dogs. Screw breakage was evident in one dog five months following surgery. PMID:18631222

  9. MANAGEMENT OF UNSTABLE THORACOLUMBAR SPINAL INJURIES BY POSTERIOR INSTRUMENTATION: A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Shivanaik

    2014-10-01

    Full Text Available BACKGROUND AND OBJECTIVES: Spinal trauma is one of the grave injuries that cause infinite morbidity and disability resulting from high energy trauma. 30-60% of all spinal injuries are concentrated in the thoracic and lumbar spine and 15-20% is associated with neurological injury. The neurological improvement is independent of treatment modality, lately consensus evolving around the world for stabilization of spine with instrumentation allowing early mobilization, prevention and limitation of neurological injury as well as restoration of spinal stability. A number of fixation systems have been advocated. The use of pedicular screws and rod system allows adequate 3 dimensional control of each motion segment and allows rigid fixation. Acceptable results have been reported in majority of patients treated with pedicle screw and rod system with good neurological recovery. The aim of the study was to access the commonest mode, level, type of fracture, efficacy of pedicle screw and rod system and the radiological, neurological and functional out come in order to recreate a stable pain free spinal column. METHODS: This study is a prospective clinical study of unstable thoracolumbar spinal injuries by posterior instrumentation (pedicular screw and rod fixation in thoracic, lumbar, and thoracolumbar spinal fractures. In all, a total of 21 cases were evaluated and assessed during the period from 1st June 2008 to 30th September 2010. The study was conducted in the Department of Orthopaedics, Vijayanagara Institute of Medical sciences, Bellary. Patient selection was according to the inclusion and exclusion criteria and was surgically treated with pedicle screw and rod system. RESULTS: In our series there were 20(94.75% males and 1(5.25% female patient with an average age of 28.3 years 17(82.1% cases due to fall from height, 4(17.9% cases following road traffic accident.16(76.1% cases were of AO Type A, 3 (14.2% of AO Type B, 2(9.52% of AO type C fractures

  10. Circumferential Calcification of Silicone Implant Misunderstood as a Bony Substitute.

    Science.gov (United States)

    Lee, Sae Bin; Min, Hyun Jin

    2016-01-01

    Silicone implant is known to be safe and easy to handle, and frequently used in Asian rhinoplasty. Compared with breast implant, complication studies about silicone calcification used in rhinoplasty are very limited. Recently, the authors experienced an interesting patient who underwent revision rhinoplasty in our institution. Based on preoperative images, previously inserted dorsal augmentation material was identified. It was circumferentially enclosed with bony material and hypertrophied bony lesion induced hump on the mid portion of nasal dorsum. During operation, the authors found it was the calcified capsule of silicone implant, and the calcification was surrounding the whole implant material. PMID:26703034

  11. Circumferential skin defect - Ilizarov technique in plastic surgery

    Directory of Open Access Journals (Sweden)

    Madhuri Vrisha

    2004-01-01

    Full Text Available A young man had an open fracture of the tibia with bone and soft tissue loss in the distal part of the left leg following a crush injury. The circumferential skin defect was successfully treated with controlled lengthening of the distal skin by the Ilizarov technique using nylon wires and skin staples to apply traction. This was combined with limb reconstruction done simultaneously using orthofix external fixator. This case report highlights the use of an orthopaedic technique to provide skin cover in distal leg.

  12. Lessons Learned After 15 Years of Circumferential Bodylift Surgery.

    Science.gov (United States)

    Small, Kevin H; Constantine, Ryan; Eaves, Felmont F; Kenkel, Jeffrey M

    2016-06-01

    Circumferential bodylift is a powerful procedure for achieving dramatic and natural body contouring changes in the massive weight loss patient. The care of these patients has raised our awareness of several important issues including safety, nutritional status, skin quality, recurrent laxity, surgical steps, and postoperative scars. Integration of this knowledge with various technical modifications over the last 15 years has improved our care for this cohort. We have not only seen a rise in the number of surgeries performed, but also the development of principles, techniques, and details that the authors feel necessary to share to achieve improved contour and more predictable outcomes. LEVEL OF EVIDENCE 4: Therapeutic. PMID:26821642

  13. [Covering of a thoraco-lumbar defect by omentoplasty].

    Science.gov (United States)

    Le Fourn, B; Loirat, Y; Sartre, J Y; Lejeune, F; Pannier, M

    1997-02-01

    With a case of thoraco-lumbar defect, the authors discuss about different procedures to cover it. In this place, the better procedure is certainly the latissimus dorsi flap, in all combinations. The indication for omentoplasty at this spinal site should not be performed by first intention but by exclusion of other procedures, as in the case considered by the authors. It was a 37-year-old man, paraplegic from the age of 16, with a deep chronic spinal wound, secondary to sepsis of a posterior segmental fixations. A staphylococcus aureus infection which developed as a surgical complication was initially treated with antibiotics and surgical cleaning procedures without removing instrumentation. However, the infection remained active and the material was finally removed. Spinal immobilisation was strengthened by external fixation. The area was cleared of all suspect material, including bone graft, leaving a wide back-wound open to the spine. Spontaneous healing was first attempted, but the size and the chronicity of the wound led us to use pedicled greater omentum to close the defect. The omentum was pedicled on the right gastroepiploic vessels and transferred to the back wound through the posterior abdominal wall muscles, next to the right kidney. This procedure allows rapid healing. In association with suitable antibiotics, it has prevented any recurrent infection after 18 months of follow-up. It was no feasible to cover the wound with a latissimus dorsi flap, considering the importance of this muscle in the movements of a paraplegic and considering the initial impossibility of removing the external fixation. PMID:9768139

  14. DETERMINATION OF EFFICIENCY OF THE CIRCUMFERENTIAL DRAINAGE SYSTEM

    Directory of Open Access Journals (Sweden)

    Maciej Kroll

    2015-11-01

    Full Text Available One of the potential alternatives to improve the stability coefficient for an embankment structure is to flatten the filtration curve. As a result, we obtain lower body forces triggering the potential landslide and more advantageous soil strength parameters, which counteract landslide movements. In the case of waste dumps lowering the phreatic surface of waters is achieved thanks to the construction of auxiliary drainage systems, meeting the guidelines for their safe operation. The aim of this paper is to indicate a method facilitating the determination of the actual position of the phreatic surface within the deposited sediments and the assessment of efficiency of the circumferential drainage system in the waste dump. It was decided in this study to apply cone penetration test CPTU. The CPTU made it possible to measure dissipation of excess water pressure in pores identifying drainage conditions, which were compared with the results of piezometric measurements. The results of these tests made it possible to monitor changes in the position of the depression curve of supernatant waters in dams and to determine the efficiency of the circumferential drainage system.

  15. New Syndrome of Congenital Circumferential Skin Folds Associated with Multiple Congenital Anomalies

    OpenAIRE

    Basel-Vanagaite, Lina; Sprecher, Eli; Gat, Andrea; Merlob, Paul; Albin-Kaplanski, Adi; Konen, Osnat; Solomon, Benjamin D.; Muenke, Maximilian; Grzeschik, Karl H; Sirota, Lea

    2011-01-01

    Congenital circumferential skin folds can be found in individuals with no additional defects, as well as in patients with multiple congenital anomalies and developmental abnormalities. Current data point to etiological heterogeneity of syndromic cases. We describe a 7-month-old girl with a novel combination of symmetrical congenital circumferential skin folds, dysmorphic features, and multiple congenital abnormalities. Examination of the patient revealed symmetrical congenital circumferential...

  16. Characterization of mechanical and geometrical properties of a tube with axial and circumferential guided waves.

    Science.gov (United States)

    Yeh, Cheng-Hung; Yang, Che-Hua

    2011-05-01

    Guided waves propagating in cylindrical tubes are frequently applied for the characterization of material or geometrical properties of tubes. In a tube, guided waves can propagate in the axial direction and called axial guided waves, or in the circumferential direction called circumferential guided waves. Dispersion spectra for the axial and circumferential guided waves share some common behaviors and however exhibit some particular behaviors of their own. This study provides an investigation with theoretical modeling, experimental measurements, and a simplex-based inversion procedure to explore the similarity and difference between the axial guided waves and circumferential guided waves, aiming at providing useful information while axial and circumferential guided waves are applied in the area of material characterization. The sensitivity to the radius curvature for the circumferential guided waves dispersion spectra is a major point that makes circumferential guided waves different from axial guided waves. For the purpose of material characterization, both axial and circumferential guided waves are able to extract an elastic moduli and wall-thickness information from the dispersion spectra, however, radius information can only be extracted from the circumferential guided waves spectra. PMID:21211810

  17. Accurate wall thickness measurement using autointerference of circumferential Lamb wave

    International Nuclear Information System (INIS)

    In this paper, a method of accurately measuring the pipe wall thickness by using noncontact air-coupled ultrasonic transducer (NAUT) was presented. In this method, accurate measurement of angular wave number (AWN) is a key technique because the AWN is changes minutely with the wall thickness. An autointerference of the circumferential (C-) Lamb wave was used for accurate measurements of the AWN. Principle of the method was first explained. Modified method for measuring the wall thickness near a butt weld line was also proposed and its accuracy was evaluated within 6 μm error. It was also shown in the paper that wall thickness measurement was accurately carried out beyond the difference among the sensors by calibrating the frequency response of the sensors. (author)

  18. Transverse shear effect in a circumferentially cracked cylindrical shell

    Science.gov (United States)

    Delale, F.; Erdogan, F.

    1979-01-01

    The objectives of the paper are to solve the problem of a circumferentially-cracked cylindrical shell by taking into account the effect of transverse shear, and to obtain the stress intensity factors for the bending moment as well as the membrane force as the external load. The formulation of the problem is given for a specially orthotropic material within the framework of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions as to moment and stress resultants on the crack surface. The effect of Poisson's ratio on the stress intensity factors and the nature of the out-of-plane displacement along the edges of the crack, i.e., bulging, are also studied.

  19. Transient thermal stress problem for a circumferentially cracked hollow cylinder

    Science.gov (United States)

    Nied, H. F.; Erdogan, F.

    1982-01-01

    The transient thermal stress problem for a hollow elasticity cylinder containing an internal circumferential edge crack is considered. It is assumed that the problem is axisymmetric with regard to the crack geometry and the loading, and that the inertia effects are negligible. The problem is solved for a cylinder which is suddenly cooled from inside. First the transient temperature and stress distributions in an uncracked cylinder are calculated. By using the equal and opposite of this thermal stress as the crack surface traction in the isothermal cylinder the crack problem is then solved and the stress intensity factor is calculated. The numerical results are obtained as a function of the Fourier number tD/b(2) representing the time for various inner-to-outer radius ratios and relative crack depths, where D and b are respectively the coefficient of diffusivity and the outer radius of the cylinder.

  20. Via de acesso para exposição ampla da coluna toracolombar anterior (T10 -L5 Extensive anterior approach to the thoracolumbar spine (T10 -L5

    Directory of Open Access Journals (Sweden)

    Roberto Augusto Caffaro

    1998-08-01

    Full Text Available Os autores descrevem técnica de via de acesso para exposição ampla da coluna toracolombar anterior (T10 -L5 a que foi submetida uma série de cem pacientes com indicação cirúrgica para correção de diversas doenças da coluna. A partir das estruturas envolvidas, são analisados e comentados os tempos operatórios pertinentes bem como as complicações transoperatórias e pós-operatórias decorrentes da técnica. Sugere-se que a técnica de acesso proposta seja utilizada quando adequada à doença a cuja correção se destina, independente da área de comprometimento clinicamente objetivada.The authors describe a technique for extensive anterior approach to the thoracolumbar spine (T10 -L5, to which 100 patients with surgical indication for correcting orthopedic anomalies were submitted. The anatomical structures involved in surgical procedures are analyzed and discussed. Results have shown that this extensive anterior approach to the thoracolumbar spine a allows the aimed approach in 100% for the cases, making easier the arthopedic management necessary to the correction of the spine deformity to be treated; b makes possible to avoid transoperative complications from the knowledge of anatomical structures exposed in the surgical field, except for the sympathetic trunk, in which lesion can occur in 70% of cases; and c presents a low rate (2% of post operative complications. It is suggested that this technique for extensive anterior approach to the thoracolumbar spine should be used, independently of the extension of the clinically diagnosed affected area.

  1. Analysis of circumferential waves on a water-filled cylindrical shell

    Institute of Scientific and Technical Information of China (English)

    FAN Wei; ZHENG Guoyin; FAN Jun

    2012-01-01

    The formation of scattering field from a water-filled cylindrical shell was studied. The analytic solutions of scattering field are derived using elastic thin shell theory and Sommerfeld-Watson Transformation (SWT) method. Complex wave-number poles of circumferential waves are found numerically, the phase speed and attenuation of circumferential waves between the situation of a hollow cylindrical shell and a water-filled cylindrical shell are compared. The synthesis of backscattering form functions which are sum of specular reflection component and circumferential waves is consistent with normal mode result. The calculated echo sequences of additional fluid circumferential waves are compared with experimental results. The results show that richer resonance peaks appeared in the backscattering form functions of a water-filled cylindrical shell and the formation of echo's structure are due to re-radiation effects of additional fluid circumferential waves.

  2. TREATMENT OF THORACOLUMBAR BURST FRACTURES FIXED WITH INTERMEDIATE PINS BY THE POSTERIOR APPROACH

    Directory of Open Access Journals (Sweden)

    Henrique Motizuki

    2015-09-01

    Full Text Available Objective:Radiographic evaluation of patients with thoracolumbar burst fractures treated with unconvencional transpedicular fixation, which includes additional fixation of the fractured vertebra associated with transverse connector - Crosslink clamp.Methods:Retrospective study evaluating a total of 68 patients operated at the Hospital do Trabalhador de Curitiba, Orthopedics Service, of which 15 were eligible for the study. All patients were treated with posterior pedicle fixation and intermediate screw. The assessment by the Cobb angle method was performed on preoperative, immediate postoperative and one year after surgery radiographs.Results:It was observed an average reduction of kyphosis of 8.3o (77%, with a loss of 1.34o in late postoperative compared to the immediate postoperative period.Conclusion:The method of fixation of burst-type fractures of the thoracolumbar spine by the posterior approach with intermediate screw was effective in maintaining the reduction achieved in the immediate postoperative period and after one year of evolution.

  3. MR imaging in the assessment of the thoracolumbar spine in elite male gymnasts

    International Nuclear Information System (INIS)

    Gymnasts training on elite level from childhood to adulthood might do serious damage to the motion segments in the thoracolumbar spine. This paper reports on twenty-five elite gymnasts (age range, 18-29 years) investigated with 0.5-T MR imaging and compared with 17 aged-matched normal males. A significantly higher number of changes in configuration of the vertebrae, apophyseal changes, end plate nodes, degenerated disks, and disk bulging in the thoracolumbar spine were found among the gymnasts. The number of degenerated disks among the gymnasts were comparable to that found at the age group of 65. Disk degeneration and change of configuration of the vertebrae were also found to correlate significantly with symptoms of back pain

  4. Bilateral transtibial amputation with concomitant thoracolumbar vertebral collapse in a Sichuan earthquake survivor

    OpenAIRE

    Lau Herman; Law Sheung-Wai; Yu Joseph; Wong Caroline; Chan Cavor

    2010-01-01

    Abstract The devastating earthquake in Sichuan, China on 12 May 2008 left thousands of survivors requiring medical care and intensive rehabilitation. In view of this great demand, the Chinese Speaking Orthopaedic Society established the "Stand Tall" project to provide voluntary services to aid amputee victims in achieving total rehabilitation and social integration. This case report highlights the multidisciplinary rehabilitation of a girl who suffered thoracolumbar vertebral collapse and und...

  5. Monosegmental fixation for the treatment of fractures of the thoracolumbar spine

    Directory of Open Access Journals (Sweden)

    Defino Helton

    2007-01-01

    Full Text Available Background : A short vertebral arthrodesis has been one of the objectives of the surgical treatment of fractures of the thoracolumbar spine. We present here clinical, functional and radiographic outcome obtained after monosegmental fixation (single posterior or combined anterior and posterior of specific types of unstable thoracolumbar fractures. Materials and Methods : Twenty four patients with fractures of the thoracolumbar spine submitted to monosegmental surgical treatment (Group I - 18 single posterior monosegmental fixations and Group II - 6 combined anterior and posterior fixations were retrospectively evaluated according to clinical, radiographic and functional parameters. The indication for surgery was instability or neurological deficit. All the procedures were indicated and performed by the senior surgeon (Helton LA Defino. Results : The patients from group I were followed-up from 2 to 12 years (mean: 6.65±2.96. The clinical, functional and radiographic results show that a single posterior monosegmental fixation is adequate and a satisfactory procedure to be used in specific types of thoracolumbar spine fractures, The patients from group II were followed-up from 9 to 15 years (mean: 13 ± 2,09 years. On group II the results of clinical evaluation showed moderate indices of residual pain and of satisfaction with the final result. The values obtained by functional evaluation showed that 66.6% of the patients were unable to return to their previous job and presented a moderate disability index (Oswestry = 16.6 and a significant reduction of quality of life based on the SF-36 questionnaire. Radiographic evaluation showed increased kyphosis of the fixed vertebral segment during the late postoperative period, accompanied by a reduction of the height of the intervertebral disk. Conclusion : It is possible to stabilize the fractures which have an anterior good load-bearing capacity by a standalone posterior monosegmental fixation. However

  6. Incidence of Vascular Complications Arising from Anterior Spinal Surgery in the Thoraco-Lumbar Spine

    OpenAIRE

    Klezl, Zdenek; Swamy, Girish Nanjunda; Vyskocil, Thomas; Kryl, Jan; Stulik, Jan

    2014-01-01

    Study Design Modern biomaterials and instrumentation have popularised surgery of the thoraco-lumbar spine through an anterior route. The advantage of anterior surgery is that it allows for a direct decompression of the compromised spinal canal. However, the potential for devastating long-term sequelae as a result of complications is high. Purpose The aim of this study was to give a general overview and identify the incidence of vascular complications. Overview of Literature There is limited l...

  7. Pre-operative digital design for osteotomy and intra-operative navigation for treatment of secondary thoracolumbar kyphosis following surgery of thoracolumbar fracture%术前数字化截骨设计及术中导航辅助技术矫正胸腰段骨折术后继发角状后凸畸形

    Institute of Scientific and Technical Information of China (English)

    樊勇; 吴子祥; 杨红军; 漆伟; 雷伟; 裴彦军; 裴国献; 桑宏勋

    2015-01-01

    Objective To evaluate the efficacy of pre-operative digital design for osteotomy and intra-operative navigation for treatment of secondary thoracolumbar kyphosis following surgery of thoracolumbar fracture.Methods Thirty-four patients with secondary thoracolumbar kyphosis following surgery of thoracolumbar fracture were treated with pedicle subtraction osteotomy (PSO) from January 2008 to April 2013.They were 18 men and 16 women,from 17 to 44 years of age (average,26.5 years).Of them,11 received traditional posterior osteotomy (unassisted group) and 23 received preoperative design with Mimics software and intraoperative navigation (assisted group).The 2 groups were compared in terms of operation time,blood loss,local deformity correction rate,cobb angle,visual analogue scale (VAS),and Oswestry disability index (ODI).Results The assisted group bad significantly shorter operation time,less blood loss and a higher deformity correction rate than the unassisted group (P < 0.05).All patients were followed up for a mean duration of 38 months (from 6 to 51 months).In all patients,the preoperative cobb angle,VAS and ODI scores were significantly improved at postoperation and the last follow-up (P < 0.05).At the last follow-up,the cobb angle,VAS and ODI scores in the assisted group were significantly better than in the unassisted group (P < 0.05).In all the patients,rigid fusion of the spinal vertebrae fixated was achieved,no implant failure occurred,the secondary thoracolumbar kyphosis was obviously corrected,and back pain disappeared.Conclusion The pre-operative digital design for osteotomy and intra-operative navigation improve the safety of PSO,therapeutic outcomes and local deformity correction for treatment of secondaU thoracolumbar kyphosis following surgery of thoracolumbar fracture.%目的 探讨联合应用术前数字化截骨设计和术中导航技术辅助矫正胸腰段骨折术后继发角状后凸畸形的有效性. 方法 2008年1至201 3年4月对34

  8. Determination of the collapse load of circumferentially cracked pipes

    International Nuclear Information System (INIS)

    Pipes related to the Primary System of PWR reactors are manufactured from high toughness austenitic and ferritic steels, which are resistant to the unstable growth of defects. A flaw in a piping system has to cause a leakage in a considerable rate, before any growth of the flaw causes a catastrophic rupture of the piping. This is the concept of LBB (Leak-Before-Break). If a conservative analysis can demonstrate that this leakage can be detected and repaired before a sudden rupture of the pipe occurs, the regulatory commission can exclude from the design basis, the postulation of a DEGB (Double-Ended Guillotine Break) hypothetic and the considerations to its associated dynamic effects. As a consequence, the protections against dynamic effects can be desconsidered, bringing an immediate economic benefice. In terms of security, the removal of the protections, give also more benefits considering the existence of more space available at the installation for inspection activities. A fundamental stage in the LBB methodology consists in the analysis of the stability of a postulated throughwall flaw in a specific piping system. In this work, the methods DPFAD (Deformation Plasticity Failure Assessment Diagram), J-T Analysis and DFM (Ductile Fracture Method) are described and applied on the determination of the instability load in some piping configurations submitted to bending containing circumferential throughwall flaws, and where geometry and material variations are considered. The instability loads obtained by these methods are compared among them and compared with some experimental results. (author)

  9. Fracture behavior of short circumferentially surface-cracked pipe

    Energy Technology Data Exchange (ETDEWEB)

    Krishnaswamy, P.; Scott, P.; Mohan, R. [Battelle, Columbus, OH (United States)] [and others

    1995-11-01

    This topical report summarizes the work performed for the Nuclear Regulatory Comniission`s (NRC) research program entitled ``Short Cracks in Piping and Piping Welds`` that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC`s PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria.

  10. Fracture behavior of short circumferentially surface-cracked pipe

    International Nuclear Information System (INIS)

    This topical report summarizes the work performed for the Nuclear Regulatory Comniission's (NRC) research program entitled ''Short Cracks in Piping and Piping Welds'' that specifically focuses on pipes with short, circumferential surface cracks. The following details are provided in this report: (i) material property deteminations, (ii) pipe fracture experiments, (iii) development, modification and validation of fracture analysis methods, and (iv) impact of this work on the ASME Section XI Flaw Evaluation Procedures. The material properties developed and used in the analysis of the experiments are included in this report and have been implemented into the NRC's PIFRAC database. Six full-scale pipe experiments were conducted during this program. The analyses methods reported here fall into three categories (i) limit-load approaches, (ii) design criteria, and (iii) elastic-plastic fracture methods. These methods were evaluated by comparing the analytical predictions with experimental data. The results, using 44 pipe experiments from this and other programs, showed that the SC.TNP1 and DPZP analyses were the most accurate in predicting maximum load. New Z-factors were developed using these methods. These are being considered for updating the ASME Section XI criteria

  11. Exoscope Update: Automated Laser Welding Of Circumferential Tissue Anastomoses

    Science.gov (United States)

    Sauer, Jude S.; McGuire, Kevin P.; Hinshaw, J. Raymond

    1989-09-01

    The speed, accuracy and efficiency of using laser energy to fuse together or weld living tissue makes laser tissue welding one of the most exciting areas of medical research today. Numerous investigators using animal models and several surgeons conducting clinical studies have demonstrated many promising potential applications of laser tissue welding. Accurate tissue positioning and well controlled delivery of laser energy during laser welding are essential for consistently successful laser tissue repairs. Many surgical procedures involve the creation of functional anastomoses, which are patent connections between hollow, tubular tissue structures, like bowel, blood vessels or fallopian tubes. We are developing the Exoscope SystemTM to automate and simplify the production of laser welded end-to-end and end-to-side anastomoses. Any laser light that can be passed through an optical fiber can be used in this system. The Exoscope SystemTM employs a fiber optic Exoscope Device,TM which provides for the precise placement of laser energy onto the abutted tissue seam, and a biocompatible, dissolvable intraluminal PolySurgeTM stent, which holds the tissue in circumferential apposition during lasing. The feasibility of employing the Exoscope SystemTM technique for the construction of rabbit small bowel anastomoses was successfully demonstrated in a Phase I study comparing 30 Exoscope SystemTM laser welded anastomoses to 30 conventional sutured anastomoses.

  12. Circumspinal decompression through a single posterior incision to treat thoracolumbar disc herniation

    Institute of Scientific and Technical Information of China (English)

    QI Qiang; SUN Chui-guo; CHEN Zhong-qiang; LIU Ning; GUO Zhao-qing; SHI Ze-feng; LIU Zhong-jun; LIU Xiao-guang; LI Wei-shi; ZENG Yan

    2011-01-01

    Background Various surgical approaches have been successfully used in the treatment of thoracolumbar disc herniation (TLDH).Although the anterior transthoracic approach has a reputation for better visualization than the posterolateral and lateral approaches,it involves the manipulation of the thoracic and pulmonary structures.Thus,this approach is technically demanding and prone to compromising the respiratory system.An ideal approach would involve adequate visualization and be accomplished through the posterior midline approach that is familiar to spine surgeons.The objective of this retrospective preliminary clinical study was to introduce a new surgical procedure,circumspinal decompression through a single posterior incision,for the treatment of TLDH (T10/11-L1/2) and to evaluate the surgical outcome of this procedure by comparing it to the conventional anterior transthoracic approach.Methods In this study,15 patients (10 males,5 females; mean age 51 years) with symptomatic TLDH underwent the circumspinal decompression through a single posterior incision procedure between January 2008 and December 2009.Altogether,17 herniated discs were excised,with 2 discs at T10/11,4 discs at T11/12,5 discs at T12/L1 and 6 discs at L1/2.Of these patients,13 were followed up with a mean follow-up period of 23.5 months.Clinical outcomes,including operative time,blood loss,perioperative complications,postoperative time of hospitalization,neurologic status improvement,back pain and correction of local kyphosis,were investigated by comparing these data with the results from patients who underwent the anterior transthoracic approach for TLDH during the same period.The patients' neurologic status was evaluated by a modified Japanese Orthopedic Association (JOA) scoring system of 11 points.Neurologic status improvement after the surgery was assessed by calculating the recovery rate,which was equal to the (postoperative JOA score-preoperative JOA score)/(11-preoperative JOA score)x100

  13. Surgical treatment in thoraco-lumbar region fractures. Tratamiento quirúrgico de las fracturas de columna en la región toracolumbar

    Directory of Open Access Journals (Sweden)

    Yoan Manuel Quiñones González

    2008-06-01

    Full Text Available Background: thoraco-lumbar fractures may affect people at any moment of their lives, especially at their most fruitful and useful stage. Its correct diagnosis and treatment may directly influence in the posterior evolution of the patients. Objectives: to evaluate the results of the surgical treatment in thoraco-lumbar region fractures. Methods: a descriptive retrospective correlational study of series cases which included 54 patients attended due to thoraco-lumbar region fractures in the University Hospital “Dr. Gustavo Aldereguía Lima” in Cienfuegos city, Cuba from January 1999 to June 2007. Age, sex, etiology of the fracture, type and level of the fractures, associated diseases, surgical techniques used for, pre and post operatory neurological damage, usage of metilprednisolone, complications and final results were the variables taken into consideration in this study. Results: most of the patients belonged to male sex under the age of 45. The totality of the cases had type IV fracture, and a great part of them had Denis type II fracture having surgical treatment. The causes of the lesions were traffic accidents, working accidents and height falls. The most useful surgical techniques were posterior decompression, instrumentation and fusion. Surgery improved the neurological damage in almost half of sick patients with this condition. Complications were minimum and rupture of the implant was predominant. Conclusion: surgical treatment in thoraco-lumbar region fractures had satisfactory results in our milieu.
    Fundamento: Las fracturas de columna vertebral pueden afectar a las personas en cualquier momento de su vida, especialmente en la etapa más útil y fructífera. Su correcto diagnóstico y tratamiento influyen directamente en la posterior evolución de los pacientes. Objetivo: Evaluar los resultados del

  14. Effect of surface contamination on osseointegration of dental implants surrounded by circumferential bone defects.

    LENUS (Irish Health Repository)

    Mohamed, Seif

    2010-05-01

    This study was designed to evaluate the effect of surface contamination on osseointegration of dental implants surrounded by a circumferential bone defect and to compare osseointegration around Osseotite with that around Nanotite implants.

  15. Circumferential Propagation of Tip Leakage Flow Unsteadiness for a Low-Speed Axial Compressor

    Institute of Scientific and Technical Information of China (English)

    Shaojuan Geng; Feng Lin; Jingyi Chen; Hongwu Zhang; Lei He

    2009-01-01

    ase shift propagating at about half of rotor rotation speed. Features of the short and long length-scale circum-ferential waves are similar to those of rotating instability and modal wave, respectively.

  16. New syndrome of congenital circumferential skin folds associated with multiple congenital anomalies.

    Science.gov (United States)

    Basel-Vanagaite, Lina; Sprecher, Eli; Gat, Andrea; Merlob, Paul; Albin-Kaplanski, Adi; Konen, Osnat; Solomon, Benjamin D; Muenke, Maximilian; Grzeschik, Karl-H; Sirota, Lea

    2012-01-01

    Congenital circumferential skin folds can be found in individuals with no additional defects, as well as in patients with multiple congenital anomalies and developmental abnormalities. Current data point to etiological heterogeneity of syndromic cases. We describe a 7-month-old girl with a novel combination of symmetrical congenital circumferential skin folds, dysmorphic features, and multiple congenital abnormalities. Examination of the patient revealed symmetrical congenital circumferential skin folds and dysmorphic features, as well as multiple congenital anomalies including nasal pyriform aperture stenosis, ventricular septal defect, absent spleen, camptodactyly, and severe psychomotor retardation. Skin biopsy demonstrated subcutaneous fat extending into the superficial and deep reticular dermis. Sequencing of the CDON, SHH, ZIC2, SIX3, and TGIF genes (associated with holoprosencephaly) did not disclose pathogenic alterations. Extensive review of previously described cases of syndromic congenital circumferential skin folds did not reveal a similar combination of clinical and histopathological findings. PMID:21995818

  17. ISSLS prize winner: cost-effectiveness of two forms of circumferential lumbar fusion

    DEFF Research Database (Denmark)

    Freeman, Brian J C; Steele, Nicholas A; Sach, Tracey H;

    2007-01-01

    STUDY DESIGN: Economic evaluation alongside a prospective, randomized controlled trial from a secondary care National Health Service (NHS) perspective. OBJECTIVE: To determine the cost-effectiveness of titanium cages (TC) compared with femoral ring allografts (FRA) in circumferential lumbar spina...

  18. Variation in circumferential resection margin: Reporting and involvement in the South-Netherlands

    NARCIS (Netherlands)

    Homan, J.; Bokkerink, G.M.J.; Aarts, M.J.; Lemmens, V.E.; Lijnschoten, G. van; Rutten, H.J.; Wijsman, J.H.; Nagtegaal, I.D.; Wilt, J.H.W. de

    2015-01-01

    BACKGROUND: Since the introduction of total mesorectal surgery the outcome of rectal cancer patients has improved significantly. Involvement of the circumferential resection margin (CRM) is an important predictor of increased local recurrence, distant metastases and decreased overall survival. Abdom

  19. Reduced Circumferential Resection Margin Involvement in Rectal Cancer Surgery: Results of the Dutch Surgical Colorectal Audit

    NARCIS (Netherlands)

    Gietelink, L.; Wouters, M.W.; Tanis, P.J.; Deken, M.M.; Berge, M.G. Ten; Tollenaar, R.A.; Krieken, J.H.J.M. van; Noo, M.E. de

    2015-01-01

    BACKGROUND: The circumferential resection margin (CRM) is a significant prognostic factor for local recurrence, distant metastasis, and survival after rectal cancer surgery. Therefore, availability of this parameter is essential. Although the Dutch total mesorectal excision trial raised awareness ab

  20. Effect of strength matching on the reliability of welded pipe with circumferential surface crack

    Institute of Scientific and Technical Information of China (English)

    何柏林; 于影霞; 霍立兴; 张玉凤

    2004-01-01

    For different strength matching, the reliability index and failure probability of welded pressure pipe with circumferential surface crack were calculated using three dimensional stochastic finite element method. This method has overcome the shortcomings of conservative results in safety assessment with deterministic fracture mechanics method. The effects of external moment and the depth of the circumferential surface crack (a) on the reliability of pressure pipe were also calculated and discussed. The calculation results indicate that the strength matching has certain effect on the reliability of the welded pressure pipe with circumferential surface crack. The failure probability of welded pressure pipe with high strength matching is lower than that with low strength matching at the same conditions. The effects of strength matching on the failure probability and reliability index increased by adding external moment (M) and the depth of the circumferential surface crack (a).

  1. Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

    OpenAIRE

    Qing Wei Li; Gui Huan Yao

    2015-01-01

    A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by t...

  2. Steady and Unsteady Flow Effects of Circumferential Grooves Casing Treatment in a Transonic Compressor Rotor

    Science.gov (United States)

    Hah, Chunill

    2011-01-01

    The current paper reports on an investigation of steady and unsteady flow effects of circumferential grooves casing treatment in a transonic compressor rotor. Circumferential grooves casing treatment is used mainly to increase stall margin in axial compressors with a relatively small decrease in aerodynamic efficiency. It is widely believed that flow mechanisms of circumferential grooves casing treatment near stall conditions are not yet well understood even though this treatment has been used widely in real engines. Numerical analysis based on steady Reynolds-averaged Navier-Stokes (RANS) has been the primary tool used to understand flow mechanism for circumferential grooves casing treatment. Although steady RANS explains some flow effects of circumferential grooves casing treatment, it does not calculate all the measured changes in the compressor characteristics. Therefore, design optimization of circumferential grooves with steady RANS has not been very successful. As a compressor operates toward the stall condition, the flow field becomes transient. Major sources of self-generated flow unsteadiness are shock oscillation and interaction between the passage shock and the tip leakage vortex. In the present paper, an unsteady Reynolds-averaged Navier-Stokes (URANS) approach is applied to study the effects of circumferential grooves in a transonic compressor. The results from URANS are compared with the results from RANS and measured data. The current investigation shows that there are significant unsteady flow effects on the performance of the circumferential grooves casing treatment. For the currently investigated rotor, the unsteady effects are of the same magnitude as the steady effects in terms of extending the compressor stall margin.

  3. Risk factors of circumferential resection margin involvement in the patients with extraperitoneal rectal cancer

    OpenAIRE

    Oh, Sung Jin; Shin, Jin Yong

    2012-01-01

    Purpose Currently, circumferential resection margins (CRM) are used as a clinical endpoint in studies on the prognosis of rectal cancer. Although the concept of a circumferential resection margin in extraperitoneal rectal cancer differs from that in intraperitoneal rectal cancer due to differences in anatomical and biologic behaviors, previous reports have provided information on CRM involvement in all types of rectal cancer including intraperitoneal lesions. Therefore, the aim of this study ...

  4. Toward Optimum Configuration of Circumferential Groove Casing Treatment in Transonic Compressor Rotors

    Science.gov (United States)

    Hah, Chunill

    2011-01-01

    The current paper first reviews experimental and numerical investigations to understand flow physics and to develop optimum configurations of circumferential grooves in compressor rotors. Circumferential grooves are used mainly to increase stall margin in axial compressors with small decrease in aerodynamic efficiency. Although circumferential groove casing treatment has been used widely, flow mechanisms of the circumferential grooves at near stall conditions are not well understood yet. Detailed time-dependent flow measurement inside tip gap in a high speed compressor is still a big challenge even though significant advance has been made in non-intrusive flow measurement technique. Therefore numerical approaches have been used to study relevant flow physics. However, optimum design of circumferential grooves to a given compressor with the computational tools is not practical yet. In the present paper, various investigations to study flow physics of circumferential groove casing treatment in axial compressor are reviewed first. Possible missing flow physics are identified and future research efforts for the optimum design are discussed.

  5. Radiological diagnosis of chronic spinal cord compressive lesion at thoraco-lumbar junction

    International Nuclear Information System (INIS)

    Radiological findings in five cases with chronic spinal cord compressive lesion at thoraco-lumbar junction were reported. Three cases had spondylosis and two cases had ossification of yellow ligament (OYL). The levels of the lesions were T12/L1 in three cases and T11/12 in two cases. Two out of three spondylotic patients had also OYL at the same level. The five cases consisted of three men and two women. The ages ranged from 42 to 60 years old with a mean age of 53 years old. Neurologically, every patient showed flaccid paresis and sensory disturbance of the legs. Two cases had sensory disturbance of stocking type. The intervals from the onset of the symptoms to the final diagnosis were 6 months, 7 years, 8 years, 11 years and 12 years. Myelography showed anterior spinal cord compression by bony spur in spondylotic patients, and posterior compression by OYL in other cases. Myelography in flexion posture disclosed the cord compression by bony spur more clearly in two out of three spondylotic patients. Delayed CT-myelography showed intramedullary filling of contrast material in two cases, which indicated degenerative change or microcavitation due to long term compression of the spinal cord. MRI was taken in three spondylotic patients and could directly show compression of the spinal cord. Difficulty in detecting abnormality at thoraco-lumbar junction on plain roentgenogram, and similarity of the symptoms to peripheral nerve disease often lead to a delay in diagnosis. The significance of dynamic myelography and delayed CT-myelography when dealing with such a lesion was discussed here. MRI is also a useful method for diagnosing a compressive lesion at the thoraco-lumbar junction. (author)

  6. Decision-making in burst fractures of the thoracolumbar and lumbar spine

    Directory of Open Access Journals (Sweden)

    Heary Robert

    2007-01-01

    Full Text Available The most common site of injury to the spine is the thoracolumbar junction which is the mechanical transition junction between the rigid thoracic and the more flexible lumbar spine. The lumbar spine is another site which is more prone to injury. Absence of stabilizing articulations with the ribs, lordotic posture and more sagitally oriented facet joints are the most obvious explanations. Burst fractures of the spine account for 14% of all spinal injuries. Though common, thoracolumbar and lumbar burst fractures present a number of important treatment challenges. There has been substantial controversy related to the indications for nonoperative or operative management of these fractures. Disagreement also exists regarding the choice of the surgical approach. A large number of thoracolumbar and lumbar fractures can be treated conservatively while some fractures require surgery. Selecting an appropriate surgical option requires an in-depth understanding of the different methods of decompression, stabilization and/or fusion. Anterior surgery has the advantage of the greatest degree of canal decompression and offers the benefit of limiting the number of motion segments fused. These advantages come at the added cost of increased time for the surgery and the related morbidity of the surgical approach. Posterior surgery enjoys the advantage of being more familiar to the operating surgeons and can be an effective approach. However, the limitations of this approach include inadequate decompression, recurrence of the deformity and implant failure. Though many of the principles are the same, the treatment of low lumbar burst fractures requires some additional consideration due to the difficulty of approaching this region anteriorly. Avoiding complications of these surgeries are another important aspect and can be achieved by following an algorithmic approach to patient assessment, proper radiological examination and precision in decision-making regarding

  7. Development and Validation of a Musculoskeletal Model of the Fully Articulated Thoracolumbar Spine and Rib Cage.

    Science.gov (United States)

    Bruno, Alexander G; Bouxsein, Mary L; Anderson, Dennis E

    2015-08-01

    We developed and validated a fully articulated model of the thoracolumbar spine in opensim that includes the individual vertebrae, ribs, and sternum. To ensure trunk muscles in the model accurately represent muscles in vivo, we used a novel approach to adjust muscle cross-sectional area (CSA) and position using computed tomography (CT) scans of the trunk sampled from a community-based cohort. Model predictions of vertebral compressive loading and trunk muscle tension were highly correlated to previous in vivo measures of intradiscal pressure (IDP), vertebral loading from telemeterized implants and trunk muscle myoelectric activity recorded by electromyography (EMG). PMID:25901907

  8. Early recurrence of thoracolumbar intervertebral disc extrusion after surgical decompression: a report of three cases

    Directory of Open Access Journals (Sweden)

    Jäderlund Karin H

    2010-02-01

    Full Text Available Abstract Thoracolumbar disc extrusions were diagnosed in three chondrodystrophic dogs with paraparesis of up to three days duration. All cases were managed by hemilaminectomy and removal of extruded disc material. In one dog, fenestration of the herniated disc space was also performed. Initially neurological function improved or was unchanged, but from two to ten days postoperatively clinical signs of deterioration became apparent. In all the dogs, recurrence of disc extrusion at the same location as the initial extrusion was diagnosed by computer tomography and at a second surgery abundant disc material was found at the hemilaminectomy site between the dura and an implanted graft of autogenous fat.

  9. Single-stage Posterior Spondylectomy,Circumferential Decompression and Reconstruction Using Mesh Cage for Spinal Tumors

    Institute of Scientific and Technical Information of China (English)

    Yong Zhu; Hong Zhao; Giu-xing Qiu; Jian-guo Zhang; Ye Tian; Shu-gang Li; Suo-mao Yuan

    2009-01-01

    Objective To explore the feasibility and clinical results of circumferential decompression and threecolumn reconstruction through single-stage posterior transpedicular approach for spinal tumor treatment.Methods Totally,24 patients with spinal tumor underwent tumor resection and spinal reconstruction through single-stage posterior transpedicular approach.Preoperatively,according to the Frankel classification,12 patients were grade E,9 grade D,and 3 grade C.Anterior column was reconstructed with non-expandable titanium cages.Posterior segmental instrumentation was used to maintain the stability of spine in all cases.Anterior and posterolateral fusion was performed with autograft and allogenic bone.The following data were followed up in these patients:deformity angle,local recurrence,neurological function,and spinal bony fusion.Results The average operating time and blood loss was 5.6 hours and 3 400 ml respectively.No intraoperative and postoperative complications were observed in this group.Postoperatively,21 patients were Frankel grade E,2 grade D,and 1 grade C.Four patients reported significant functional restoration and twenty patients reported complete resolution of pain.At follow-up(range,6-42 months),implant failure or recurrent neurological symptoms was not found.Conclusions The tumor resection and spinal reconstruction through single-stage posterior transpedicular approach is a safe and effective technique for the treatment of spinal tumor.It can fully decompress the neurological structures,correct the kyphosis,and achieve early weight-bearing.This technique can improve life quality for the patients with spinal tumor.

  10. Depression of the Thoracolumbar Posterior Vertebral Body on the Estimation of Cement Leakage in Vertebroplasty and Kyphoplasty Operations

    Directory of Open Access Journals (Sweden)

    Hao Chen

    2015-01-01

    Conclusions: Depression of the thoracolumbar posterior vertebral body may be informative for the estimation of cement location on C-arm images. To reduce type-B leakage, DCPW should be made longer than DBCV on C-arm images for safety during PVP or PKP.

  11. Combined Anterior-Posterior Surgery Versus Posterior Surgery for Thoracolumbar Burst Fractures: A Systematic Review of the Literature

    NARCIS (Netherlands)

    P.P. Oprel (Pim); W.E. Tuinebreijer (Wim); P. Patka (Peter); D. den Hartog (Dennis)

    2010-01-01

    textabstractAbstract: Study Design: A systematic quantitative review of the literature. Objective: To compare combined anterior-posterior surgery versus posterior surgery for thoracolumbar fractures in order to identify better treatments. Summary of Background Data: Axial load of the anterior and mi

  12. Accuracy of ultrasound-guided injections of thoracolumbar articular process joints in horses

    DEFF Research Database (Denmark)

    Fuglbjerg, Vibeke; Nielsen, J.V.; Thomsen, Preben Dybdahl;

    2010-01-01

    Reasons for performing study: Arthrosis of the articular process joints (APJs) in the caudal thoracolumbar region of horses may cause back pain and subsequent reduced performance or lameness. Ultrasound-guided injections of the APJs of the equine back have been described only briefly in the liter......Reasons for performing study: Arthrosis of the articular process joints (APJs) in the caudal thoracolumbar region of horses may cause back pain and subsequent reduced performance or lameness. Ultrasound-guided injections of the APJs of the equine back have been described only briefly...... unrelated to back problems. The backs were subsequently dissected to verify the location of the injectate in relation to the APJs. Results: Twenty-seven percent of the injections were found to be intra-articular and a total of 77% found to be within 2 mm of the joint capsule including the intra......-articular deposits. Application of a medial approach and 18 gauge needle were significantly associated with an intra-articulr injection or deposition close to the joint capsule. Operator, APJ (location) and back number (chronological) did not significantly affect the accuracy of injection. Conclusions and potential...

  13. Can MRI Findings Help to Predict Neurological Recovery in Paraplegics With Thoracolumbar Fracture?

    Science.gov (United States)

    Lee, Joonchul; Koh, Seong-Eun; Jung, Heeyoune; Lee, Hye Yeon

    2015-01-01

    Objective To evaluate the usefulness of various magnetic resonance imaging (MRI) findings in the prognosis of neurological recovery in paraplegics with thoracolumbar fracture using association analysis with clinical outcomes and electrodiagnostic features. Methods This retrospective study involved 30 patients treated for paraplegia following thoracolumbar fracture. On axial and sagittal T2-weighted MRI scans, nerve root sedimentation sign, root aggregation sign, and signal intensity changes in the conus medullaris were independently assessed by two raters. A positive sedimentation sign was defined as the absence of nerve root sedimentation. The root aggregation sign was defined as the presence of root aggregation in at least one axial MRI scan. Clinical outcomes including the American Spinal Injury Association impairment scale, ambulatory capacity, and electrodiagnostic features were used for association analysis. Results Inter-rater reliability of the nerve root sedimentation sign and the root aggregation sign were κ=0.67 (p=0.001) and κ=0.78 (prehabilitation program (χ2=4.854, p=0.028). The presence of the root aggregation sign was associated with reduced compound muscle action potential amplitude of common peroneal and tibial nerves in nerve conduction studies (χ2=5.026, p=0.025). Conclusion A positive sedimentation sign was significantly associated with recovery of ambulatory capacity and not indicative of persistent paralysis. The root aggregation sign suggested the existence of significant cauda equina injuries. PMID:26798606

  14. Technical considerations in transforaminal endoscopic spine surgery at the thoracolumbar junction: report of 3 cases.

    Science.gov (United States)

    Telfeian, Albert E; Jasper, Gabriele P; Oyelese, Adetokunbo A; Gokaslan, Ziya L

    2016-02-01

    OBJECTIVE In this study the authors describe the technical considerations and feasibility of transforaminal discectomy and foraminoplasty for the treatment of lumbar radiculopathy in patients who have herniated discs at the thoracolumbar junction. METHODS After institutional review board approval, charts from 3 consecutive patients with lumbar radiculopathy and T12-L1 herniated discs who underwent endoscopic procedures between 2006 and 2014 were reviewed. RESULTS Consecutive cases (n = 1316) were reviewed to determine the incidence and success of surgery performed at the T12-L1 level. Only 3 patients (0.23%) treated with endoscopic surgery for their herniated discs had T12-L1 herniated discs; the rest were lumbar or lumbosacral herniations. For patients with T12-L1 disc herniations, the average preoperative visual analog scale score was 8.3 (indicated in the questionnaire as describing severe and constant pain). The average 1-year postoperative visual analog scale score was 1.7 (indicated in the questionnaire as mild and intermittent pain). CONCLUSIONS Transforaminal endoscopic discectomy and foraminotomy can be used as a safe yet minimally invasive technique for the treatment of lumbar radiculopathy in the setting of a thoracolumbar disc herniation. PMID:26828890

  15. Numerical investigation of a centrifugal compressor with circumferential grooves in vane diffuser

    Science.gov (United States)

    Chen, X. F.; Qin, G. L.; Ai, Z. J.

    2015-08-01

    Enhancing stall and surge margin has a great importance for the development of turbo compressors. The application of casing treatment is an effective measure to expand the stall margin and stable operation range. Numerical investigations were conducted to predict the performance of a low flow rate centrifugal compressor with circumferential groove casing treatment in vane diffuser. Numerical cases with different radial location, radial width and axial depth of a circumferential single groove and different numbers of circumferential grooves were carried out to compare the results. The CFD analyses results show that the centrifugal compressor with circumferential grooves in diffuser can extend stable range by about 9% while the efficiency over the whole operating range decreases by 0.2 to 1.7%. The evaluation based on stall margin improvement showed the optimal position for the groove to be located was indicated to exist near the leading edge of the diffuser, and a combination of position, width, depth and numbers of circumferential grooves that will maximize both surge margin range and efficiency.

  16. Accelerated circumferential strain quantification of the left ventricle using CIRCOME: simulation and factor analysis

    Science.gov (United States)

    Moghaddam, Abbas N.; Finn, J. Paul

    2008-03-01

    Circumferential strain of the left ventricle reflects myocardial contractility and is considered a key index of cardiac function. It is also an important parameter in the quantitative evaluation of heart failure. Circumferential compression encoding, CIRCOME, is a novel method in cardiac MRI to evaluate this strain non-invasively and quickly. This strain encoding technique avoids the explicit measurement of the displacement field and does not require calculation of strain through spatial differentiation. CIRCOME bypasses these two time-consuming and noise sensitive steps by directly using the frequency domain (k-space) information from radially tagged myocardium, before and after deformation. It uses the ring-shaped crown region of the k-space, generated by the taglines, to reconstruct circumferentially compression-weighted images of the heart before and after deformation. CIRCOME then calculates the circumferential strain through relative changes in the compression level of corresponding regions before and after deformation. This technique can be implemented in 3D as well as 2D and may be employed to estimate the overall global or regional circumferential strain. The main parameters that affect the accuracy of this method are spatial resolution, signal to noise ratio, eccentricity of the center of radial taglines their fading and their density. Also, a variety of possible image reconstruction and filtering options may influence the accuracy of the method. This study describes the pulse sequence, algorithm, influencing factors and limiting criteria for CIRCOME and provides the simulated results.

  17. Application of induced circumferential current for cracks inspection on pipe string

    Science.gov (United States)

    Yuan, Xin'an; Li, Wei; Yin, Xiaokang; Chen, Guoming; Ge, Jiuhao

    2016-02-01

    Pipe strings (such as drill pipe, tube, pipeline, riser) are critical facilities in oil & gas industry, which are highly susceptible to cracks caused by stress corrosion and fatigue damage. The most common defects are longitudinal and transverse surface cracks on pipe strings in oil & gas industry. Conventional nondestructive testing (NDT) methods are inadequate for these surface cracks on pipe strings. In this paper, a full 360° circumferential current induced by a coaxial excitation coil is present for inspection of longitudinal and transverse surface cracks on pipe strings. The finite element method (FEM) is employed to obtain characteristics signals by analyzing the distorted electromagnetic field above the cracks. The induced circumferential current test system is set up and crack inspection experiments are carried out. The results show that both longitudinal and transverse surface cracks can be detected effectively at one pass scanning on pipe string using the induced circumferential current.

  18. Percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system: an analysis of 38 cases

    OpenAIRE

    Wang, Hong-Wei; Li, Chang-Qing; Zhou, Yue; Zhang, Zheng-Feng; Wang, Jian; Chu, Tong-Wei

    2010-01-01

    To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system in the retrospective non- randomized case-control study.

  19. A study on nondestructive evaluation techniques for composite motors cases using circumferential waves

    International Nuclear Information System (INIS)

    For structural integrity evaluation of composite rocket motor cases, acoustic emission (AE) during hydroproof test is currently used. For the suitable performance of this test, it is very important to determine the optimal component of elastic waves to be monitored. In this study, the optimal component of circumferential wave that propagate in the circumferential direction of the composite motor case has been determined experimentally. Then its potential to be served as a robust tool for nondestructive evaluation of composite motor cases was demonstrated by investigating the initial performances for flaw detection and AE source location.

  20. Aerodynamic Inner Workings of Circumferential Grooves in a Transonic Axial Compressor

    Science.gov (United States)

    Hah, Chunill; Mueller, Martin; Schiffer, Heinz-Peter

    2007-01-01

    The current paper reports on investigations of the fundamental flow mechanisms of circumferential grooves applied to a transonic axial compressor. Experimental results show that the compressor stall margin is significantly improved with the current set of circumferential grooves. The primary focus of the current investigation is to advance understanding of basic flow mechanics behind the observed improvement of stall margin. Experimental data and numerical simulations of a circumferential groove were analyzed in detail to unlock the inner workings of the circumferential grooves in the current transonic compressor rotor. A short length scale stall inception occurs when a large flow blockage is built on the pressure side of the blade near the leading edge and incoming flow spills over to the adjacent blade passage due to this blockage. The current study reveals that a large portion of this blockage is created by the tip clearance flow originating from 20% to 50% chord of the blade from the leading edge. Tip clearance flows originating from the leading edge up to 20% chord form a tip clearance core vortex and this tip clearance core vortex travels radially inward. The tip clearance flows originating from 20% to 50% chord travels over this tip clearance core vortex and reaches to the pressure side. This part of tip clearance flow is of low momentum as it is coming from the casing boundary layer and the blade suction surface boundary layer. The circumferential grooves disturb this part of the tip clearance flow close to the casing. Consequently the buildup of the induced vortex and the blockage near the pressure side of the passage is reduced. This is the main mechanism of the circumferential grooves that delays the formation of blockage near the pressure side of the passage and delays the onset of short length scale stall inception. The primary effect of the circumferential grooves is preventing local blockage near the pressure side of the blade leading edge that

  1. Molecular Modeling of the Axial and Circumferential Elastic Moduli of Tubulin

    OpenAIRE

    Zeiger, A. S.; Layton, B. E.

    2008-01-01

    Microtubules play a number of important mechanical roles in almost all cell types in nearly all major phylogenetic trees. We have used a molecular mechanics approach to perform tensile tests on individual tubulin monomers and determined values for the axial and circumferential moduli for all currently known complete sequences. The axial elastic moduli, in vacuo, were found to be 1.25 GPa and 1.34 GPa for α- and β-bovine tubulin monomers. In the circumferential direction, these moduli were 378...

  2. Biomechanical evaluation of vertebroplasty using calcium sulfate cement for thoracolumbar burst fractures

    Institute of Scientific and Technical Information of China (English)

    WU Xiao-tao; JIANG Xing-jie; ZHANG Shao-dong; YANG Hui-lin

    2007-01-01

    Objective: To evaluate the biomechanical performance of vertebroplasty using calcium sulfate cement for thoracolumbar burst fractures.Methods: Sixteen bovine thoracolumbar spines (T11-L1 ) were divided into 4 groups (A, B, C and D). After burst-fracture model was created, 12 vertebral bodies in Groups A, B and C were augmented with calcium sulfate cement (CSC), calcium phosphate cement (CPC) and polymethylmethacrylate ( PMMA ) bone cement,respectively. Each anterior vertebral body height was measured with a caliper at 4 time points: intact conditions(HInt), post-fracture (HFr), post-reduction (HRe) and post-vertebroplasty (HVP). The filling volume of 3 different bone cements was also measured. Each vertebral body was compressed at 0.5 mm/s using a hinged plating system on a materials testing machine to 50% of the postvertebroplasty height to determine strength and stiffness.Difference was checked using t test or One-way ANOVA.Results: The average strike energy was 66. 2 J.Vertebroplasty with different cements could sustain vertebral height. The average filling volume of bone cement in 3 groups was 4.35 ml (CSC), 3.72 ml (CPC) and 3.95 ml (PMMA), respectively, and there was no statistically significant difference among them ( P >0.05).Vertebroplasty with PMMA completely restored strength(116%) and stiffness (105%). CSC or CPC partly recovered vertebral strength and stiffness. However,greater strength restoration was got with CSC ( 1 659 N) as compared with CPC (1 011N, P<0.01 ). Regarding stiffness, differences between CSC (140 N/mm ±40 N/mm)and the other two bone cements ( CPC :148 N/mm ±33 N/mm,PMMA:236 N/mm ±97 N/mm) were not significant (P>0.05).Conclusions: For a burst-fracture of calf spine, useof CSC for vertebroplasty yields similar vertebral stiffnessas compared with PMMA or CPC. Although augmentationwith CSC partly obtains the normal strength, thistreatment still can be applied in thoracolumbar burstfractures with other instrumental devices in

  3. Comparison of three different surgical approaches for treatment of thoracolumbar burst fracture

    Institute of Scientific and Technical Information of China (English)

    WU Han; WANG Chun-xin; GU Chang-yue; ZHANG Zi-yan; TONG Shen; YAN Hua-dong; WANG Jin-cheng

    2013-01-01

    Objective:The main treatment method used for thoracolumbar fractures is open reduction and internal fixation.Commonly there are three surgical approaches:anterior,posterior and paraspinal.We attempt to compare the three approaches based on our clinical data analysis.Methods:A group of 94 patients with Denis type A or B thoracolumbar burst fracture between March 2008 and September 2010 were recruited in this study.These patients were treated by anterior-,posterior-or paraspinal-approach reduction with or without decompression.The fracture was fixed with titanium mesh and Z-plate via anterior approach (24 patients),screw and rod system via posterior approach (38 patients) or paraspinal approach (32 patients).Clinical evaluations included operation duration,blood loss,incision length,preoperative and postoperative Oswestry disability index (ODI).Results:The average operation duration (94.1 min±13.7min),blood loss (86.7 ml±20.0 ml),length of incision (9.3mm± 0.7 mm) and postoperative ODI (6±0.5) were significandy lower (P<0.05) in paraspinal approach group than in traditional posterior approach group (operation duration 94.1 min±13.7 min,blood loss 143.3 ml±28.3 ml,length of incision 15.4 cm±2.1 cm and ODI 12±0.7) and anterior approach group (operation duration 176.3 min±20.7 min,blood loss 255.1 m1±38.4 ml,length of incision 18.6 cm±2.4 cm and OD113±2.4).There was not statistical difference in terms of Cobb angle on radiographs among the three approaches.Conclusion:The anterior approach surgery is convenient for resection of the vertebrae and reconstruction of vertebral height,but it is more complicated and traumatic.Hence it is mostly used for severe Denis type B fracture.The posterior approach is commonly applied to most thoracolumbar fractures and has fewer complications compared with the anterior approach,but it has some shortcomings as well.The paraspinal approach has great advantages compared with the other two approaches.It is in accordance with

  4. Hybrid cadaveric/surrogate model of thoracolumbar spine injury due to simulated fall from height.

    Science.gov (United States)

    Ivancic, Paul C

    2013-10-01

    A fall from high height can cause thoracolumbar spine fracture with retropulsion of endplate fragments into the canal leading to neurological deficit. Our objectives were to develop a hybrid cadaveric/surrogate model for producing thoracolumbar spine injury during simulated fall from height, evaluate the feasibility and performance of the model, and compare injuries with those observed clinically. Our model consisted of a 3-vertebra human lumbar specimen (L3-L4-L5) stabilized with muscle force replication and mounted within an impact dummy. The model was subjected to a fall from height of 2.2 m with impact velocity of 6.6 m/s. Kinetic and kinematic time-history responses were determined using spinal and pelvis load cell data and analyses of high-speed video. Injuries to the L4 vertebra were evaluated by fluoroscopy, radiography, and detailed anatomical dissection. Peak compression forces during the fall from height occurred at 7 ms and reached 44.7 kN at the ground, 9.1 kN at the pelvis, and 4.5 kN at the spine. Pelvis acceleration peaks reached 209.9 g at 8 ms for vertical and 62.8 g at 12 ms for rearward. Tensile load peaks were then observed (spine: 657.0 N at 47 ms; pelvis: 569.4 N at 61 ms). T1/pelvis peak flexion of 68.3° occurred at 38 ms as the upper torso translated forward while the pelvis translated rearward. Complete axial burst fracture of the L4 vertebra was observed including endplate comminution, retropulsion of bony fragments into the canal, loss of vertebral body height, and increased interpedicular distance due to fractures anterior to the pedicles and a vertical split fracture of the left lamina. Our dynamic injury model closely replicated the biomechanics of real-life fall from height and produced realistic, clinically relevant burst fracture of the lumbar spine. Our model may be used for further study of thoracolumbar spine injury mechanisms and injury prevention strategies. PMID:23792617

  5. Comparison of three different surgical approaches for treatment of thoracolumbar burst fracture

    Directory of Open Access Journals (Sweden)

    WU Han

    2013-02-01

    Full Text Available 【Abstract】Objective: The main treatment method used for thoracolumbar fractures is open reduction and in-ternal fixation. Commonly there are three surgical approaches: anterior, posterior and paraspinal. We attempt to compare the three approaches based on our clinical data analysis. Methods: A group of 94 patients with Denis type A or B thoracolumbar burst fracture between March 2008 and September 2010 were recruited in this study. These patients were treated by anterior-, posterior- or paraspinal-approach reduction with or without decompression. The fracture was fixed with titanium mesh and Z-plate via anterior approach (24 patients, screw and rod system via posterior approach (38 patients or paraspinal approach (32 patients. Clinical evaluations included operation duration, blood loss, inci-sion length, preoperative and postoperative Oswestry dis-ability index (ODI. Results: The average operation duration (94.1 min±13.7 min, blood loss (86.7 ml±20.0 ml, length of incision (9.3 mm± 0.7 mm and postoperative ODI (6±0.5 were signifi-cantly lower (P<0.05 in paraspinal approach group than in traditional posterior approach group (operation duration 94.1 min±13.7 min, blood loss 143.3 ml±28.3 ml, length of incision 15.4 cm±2.1 cm and ODI 12±0.7 and anterior approach group (operation duration 176.3 min±20.7 min, blood loss 255.1 ml±38.4 ml, length of incision 18.6 cm±2.4 cm and ODI 13±2.4. There was not statistical difference in terms of Cobb angle on radiographs among the three approaches. Conclusion: The anterior approach surgery is conve-nient for resection of the vertebrae and reconstruction of vertebral height, but it is more complicated and traumatic. Hence it is mostly used for severe Denis type B fracture. The posterior approach is commonly applied to most thora-columbar fractures and has fewer complications compared with the anterior approach, but it has some shortcomings as well. The paraspinal approach has great advantages

  6. Determination of the minimum number exposures in radiographic examination of circumferential welds

    International Nuclear Information System (INIS)

    Certain specifications require that, in the radiography of circumferential welds, the penetrated thickness at the side of the beam should not exceed the wall thickness by more than a given percentage. A mathematical solution is presented, which shows the minimum number of exposures in accurate and easy-to-read diagrams suitable for use by field radiographers. (orig.)

  7. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Science.gov (United States)

    2010-10-01

    ..., tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 52.01-1) except as noted otherwise in this section. (b) (Modifies PW-41.1) Circumferential welded joints in pipes, tubes, and headers of pipe material must be nondestructively examined...

  8. Modification of the ASME code z-factor for circumferential surface crack in nuclear ferritic pipings

    International Nuclear Information System (INIS)

    The purpose of this paper is to modify the ASME Code Z-Factor, which is used in the evaluation of circumferential surface crack in nuclear ferritic pipings. The ASME Code Z-Factor is a load multiplier to compensate plastic load with elasto-plastic load. The current ASME Code Z-Factor underestimates pipe maximum load. In this study, the original SC. TNP method is modified first because the original SC. TNP method has a problem that the maximum allowable load predicted from the original SC. TNP method is slightly higher than that measured from the experiment. Then the new Z-Factor is developed using the modified SC. TNP method. The desirability of both the modified SC. TNP method and the new Z-Factor is examined using the experimental results for the circumferential surface crack in pipings. The results show that (1) the modified SC. TNP method is good for predicting the circumferential surface crack behavior in pipings, and (2) the Z-Factor obtained from the modified SC. TNP method well predicts the behavior of circumferential surface crack in ferritic pipings. 30 refs., 13 figs., 4 tabs. (author)

  9. Consideration on evaluation of internal pressure creep rupture for tube with circumferential joint

    International Nuclear Information System (INIS)

    The behavior of internal pressure creep rupture of the thin-walled cylinders with circumferential joints is affected by the combination of creep characteristics of parent materials and weld metals. In particular, the compatibility of the creep strain rate of parent materials and weld metals becomes an important controlling factor. The behavior of internal pressure creep of the welded parts in circumferential joint cylinders can be evaluated simply with the uniaxial creep data of parent materials and weld metals, considering it by approximately substituting with the creep behavior of a uniaxial longitudinal joint. The method of evaluation is, first, to analyze the breaking behavior of uniaxial longitudinal joints using the uniaxial creep characteristic values of parent materials and weld metals, and next, by combining the equation for the relation between the rupture times of uniaxial creep and internal pressure creep with the analyzed breaking behavior of uniaxial joints, the internal pressure creep rupture behavior of the cylinders with circumferential joints can be evaluated. The internal pressure creep behavior of the thin-walled cylinders with circumferential joints, their rupture life and the uniaxial creep rupture life of longitudinal joints, and the examination of Hastelloy X cylinders are reported. (Kako, I.)

  10. Correlation of outcome measures with epidemiological factors in thoracolumbar spinal trauma

    Directory of Open Access Journals (Sweden)

    Upendra Bidre

    2007-01-01

    Full Text Available Background : The epidemiological data of a given population on spinal trauma in India is lacking. The present study was undertaken to evaluate the profile of patients with thoracolumbar fractures in a tertiary care hospital in an urban setup. Materials and Methods : Four hundred forty patients with thoracolumbar spinal injuries admitted from January 1990 to May 2000 to the All India Institute of Medical Sciences were included in the analysis. Both retrospective data retrieval and prospective data evaluation of patients were done from January 1998 to May 2000. Epidemiological factors like age, sex and type of injury, mode of transport, time of reporting and number of transfers before admission were recorded. Frankel′s grading was used to assess neurological status. Functional assessment of all patients was done using the FIM™ instrument (Functional Independence Measure. Average follow-up was 33 months (24-41 months. Results : Of the 440 patients, females comprised 17.95% (n=79, while 82.04% (n=361 were males. As many as 40.9% (n=180 of them were in the third decade. Fall from height remained the most common cause 52.3% (n=230. Two hundred sixty (59.1% patients reported within 48 hours. Thirty-two (7.27% patients had single transfer, and all 32 showed complete independence for mobility at final follow-up. 100 of 260 (38.5% patients reporting within 48 hours developed pressure sores, while 114 of 142 (80.28% patients reporting after 5 days developed pressure sores. Conclusion : The present study highlights the magnitude of the problems of our trauma-care and transport system and the difference an effective system can make in the care of spinal injury patients. There is an urgent need for epidemiological data on a larger scale to emphasize the need for a better trauma-care system and pave way for adaptation of well-established trauma-care systems from developed countries.

  11. Biomechanics of Thoracolumbar Burst and Chance-Type Fractures during Fall from Height

    Science.gov (United States)

    Ivancic, Paul C.

    2014-01-01

    Study Design In vitro biomechanical study. Objective To investigate the biomechanics of thoracolumbar burst and Chance-type fractures during fall from height. Methods Our model consisted of a three-vertebra human thoracolumbar specimen (n = 4) stabilized with muscle force replication and mounted within an impact dummy. Each specimen was subjected to a single fall from an average height of 2.1 m with average velocity at impact of 6.4 m/s. Biomechanical responses were determined using impact load data combined with high-speed movie analyses. Injuries to the middle vertebra of each spinal segment were evaluated using imaging and dissection. Results Average peak compressive forces occurred within 10 milliseconds of impact and reached 40.3 kN at the ground, 7.1 kN at the lower vertebra, and 3.6 kN at the upper vertebra. Subsequently, average peak flexion (55.0 degrees) and tensile forces (0.7 kN upper vertebra, 0.3 kN lower vertebra) occurred between 43.0 and 60.0 milliseconds. The middle vertebra of all specimens sustained pedicle and endplate fractures with comminution, bursting, and reduced height of its vertebral body. Chance-type fractures were observed consisting of a horizontal split fracture through the laminae and pedicles extending anteriorly through the vertebral body. Conclusions We hypothesize that the compression fractures of the pedicles and vertebral body together with burst fracture occurred at the time of peak spinal compression, 10 milliseconds. Subsequently, the onset of Chance-type fracture occurred at 20 milliseconds through the already fractured and weakened pedicles and vertebral body due to flexion-distraction and a forward shifting spinal axis of rotation. PMID:25083357

  12. Creating reproducible thoracolumbar burst fractures in human specimens: an in vitro experiment.

    Science.gov (United States)

    Oberkircher, Ludwig; Schmuck, Maya; Bergmann, Martin; Lechler, Philipp; Ruchholtz, Steffen; Krüger, Antonio

    2016-04-01

    OBJECT The treatment of traumatic burst fractures unaccompanied by neurological impairment remains controversial and ranges from conservative management to 360° fusion. Because of the heterogeneity of fracture types, classification systems, and treatment options, comparative biomechanical studies might help to improve our knowledge. The aim of the current study was to create a standardized fracture model to investigate burst fractures in a multisegmental setting. METHODS A total of 28 thoracolumbar fresh-frozen human cadaveric spines were used. The spines were dissected into segments (T11-L3). The T-11 and L-3 vertebral bodies were embedded in Technovit 3040 (cold-curing resin for surface testing and impressions). To simulate high energy, a metallic drop tower was designed. Stress risers were used to ensure comparable fractures. CT scans were acquired before and after fracture. All fractures were classified using the AO/OTA classification. RESULTS The preparation and embedding of the spine segments worked well. No repositioning or second embedding of the specimen, even after fracture, was required. It was possible to create single burst fractures at the L-1 level in all 28 spine segments. Among the 28 fractures there were 16 incomplete burst fractures (Type A3.1), 8 burst-split fractures (Type A3.2), and 4 complete burst fractures (Type A3.3). The differences before and after fracture for stiffness and for anterior, posterior, and central heights were all significant (p < 0.05). CONCLUSIONS The ability to create reproducible burst fractures of a single vertebral body in a thoracolumbar spine segment may serve as a basis for future biomechanical studies that will provide better understanding of mechanical properties or fixation techniques. PMID:26682598

  13. A method for measuring mean circumferential fiber shortening rate from gated blood pool scans

    International Nuclear Information System (INIS)

    Ejection fraction and ejection rate are easily obtained from gated cardiac images, but no method is available for calculating mean circumferential fiber shortening rate. We assumed that the cube root of left ventricular end-diastolic volume or counts is proportional to the minor axis of the left ventricle at end-diastole or end-systole. Mean circumferential fiber shortening rate is then equal to the [cube root of the end-diastolic volume (count) minus cube root of end-systolic volume (count)] divided by [cube root of end-diastolic volume (count) multiplied by the ejection time]. In 250 contrast ventriculograms, the standard mean circumferential fiber shortening rate (MCFSR) and that derived by the cube root method correlated well (r = 0.94). The mean value of MCFSR (0.85 +- 0.35) was greater than the cube root value (0.75 +- 0.35) (P < 0.001). The regression equation was y = 0.86x + 0.02. Similar correlations were obtained from gated radionuclide images using a semiautomated program (r = 0.93) in 24 subjects or completely automated program (r = 0.85) in 28 patients. The regression equation between MCFSR and that derived from the cube root of counts for the semiautomated program was y = 0.82x + 0.04 and for the automated program was y = 0.84x + 0.004. Similar correlations, slopes, and intercepts were seen using circumferential fractional shortening for angiographic data when correlated with both the semiautomated and automated gated blood pool scan programs. These data indicate that MCFSR and circumferential fractional shortening may be obtained from gated blood pool images using cube root estimates of end-diastolic and end-systolic radii with a high degree of correlation with the standard contrast ventriculographic technique. (orig.)

  14. "Free-hand" technique for thoracolumbar pedicle screw instrumentation: Critical appraisal of current "State-of-Art"

    Directory of Open Access Journals (Sweden)

    Mattei Tobias

    2009-01-01

    Full Text Available Pedicle screws are widely used for instrumentation of the thoracolumbar spine. The anatomic studies performed in the last two decades, detailing the complex morphometry and three-dimensional anatomy of the thoracolumbar pedicles, have enabled the emergence of the so-called "free-hand" technique of pedicle screw placement based exclusively on anatomical parameters. However, in the thoracic spine, the benefits of pedicle screws have been tempered by its potential risks, such as, spinal canal violation, pedicle fracture, nerve root compression, and vascular lesions. Furthermore, the narrow and inconsistent shape of the thoracic pedicles, especially in spinal deformity, makes their placement technically challenging. In this article, the authors make a critical appraisal of current "state-of-art" of "free-hand" technique of pedicle instrumentation, analyzing its anatomical basis, surgical technique, present indications and limitations as well as the role of adjuvant image-guided and neurophysiological monitoring methods.

  15. Clinical observation of umbilical cord mesenchymal stem cell transplantation in treatment for sequelae of thoracolumbar spinal cord injury

    OpenAIRE

    Cheng, Hongbin; Liu, Xuebin; Hua, Rongrong; Dai, Guanghui; Wang, Xiaodong; Gao, Jianhua; An, Yihua

    2014-01-01

    Background Umbilical cord mesenchymal stem cells (UCMSCs) have a considerable advantage and potential in treating for central nervous system diseases and have become a novel alternative treatment for spinal cord injury. This study aims to compare the neurological function outcome of stem cell transplantation, rehabilitation therapy, and self-healing for sequelae of spinal cord injury. Methods Thirty-four cases of thoracolumbar spinal cord injury were randomly divided into three groups: the st...

  16. Ultrasound Evaluation of the Combined Effects of Thoracolumbar Fascia Injury and Movement Restriction in a Porcine Model

    OpenAIRE

    Bishop, James H.; James R Fox; Maple, Rhonda; Loretan, Caitlin; Badger, Gary J.; Henry, Sharon M.; Vizzard, Margaret A.; Langevin, Helene M.

    2016-01-01

    The persistence of back pain following acute back “sprains” is a serious public health problem with poorly understood pathophysiology. The recent finding that human subjects with chronic low back pain (LBP) have increased thickness and decreased mobility of the thoracolumbar fascia measured with ultrasound suggest that the fasciae of the back may be involved in LBP pathophysiology. This study used a porcine model to test the hypothesis that similar ultrasound findings can be produced experime...

  17. The Effects of Glucocorticoid and Voluntary Exercise Treatment on the Development of Thoracolumbar Kyphosis in Dystrophin-Deficient Mice

    OpenAIRE

    Brereton, Daniel; Plochocki, Jeffrey; An, Daniel; Costas, Jeffrey; Simons, Erin

    2012-01-01

    The development of spinal curvature deformities is a hallmark of muscular dystrophy. While glucocorticoid treatment has been shown to prolong muscle function in dystrophic mice, its effects on the development of dystrophinopathic spinal deformation are poorly understood. In this study, we test the effects of glucocorticoid treatment on the onset of thoracolumbar kyphosis in the dystrophin-deficient mdx mouse using voluntary running exercise to exacerbate muscle fibrosis. We measure the kyphot...

  18. Magnetic resonance imaging study determining cord level and occupancy at thoracolumbar junction in achondroplasia – A prospective study

    OpenAIRE

    Modi, Hitesh N; Seung-Woo Suh; Jae-Young Hong; Jae-Hyuk Yang

    2011-01-01

    Background: Thoracolumbar (TL) stenosis in achondroplasia is frequently reported, and becomes symptomatic in adulthood. Hence we conducted a prospective study to determine cord level and occupancy at TL junction in symptomatic or asymptomatic achondroplasis patients in comparision to normal population by magnetic resonance imaging (MRI). Materials and Methods: Cord level with its occupancy rate and TL kyphosis were measured on MRI and standing radiogram, respectively. We prospectively stu...

  19. Comparison of therapeutic effects of anterior decompression and posterior decompression on thoracolumbar spine fracture complicated with spinal nerve injury

    OpenAIRE

    Cui, Hongxun; Guo, Jiayi; Lei YANG; Guo, Yanxing; Guo, Malong

    2015-01-01

    Objective: To compare the clinical therapeutic effects of anterior decompression and posterior decompression on thoracolumbar spine fracture (TSF) complicated with spinal nerve injury (SNI). Methods: A total of 120 patients with TSF and SNI were selected and divided into a treatment group and a control group that were then treated by anterior decompression and posterior decompression respectively. The preoperative and postoperative motor scores, tactile scores, heights of injured vertebral bo...

  20. Analysis of dispersion characteristics of circumferential guided waves and detection of axial cracks in pipe

    International Nuclear Information System (INIS)

    A circumferential guided wave method was developed to detect the axial crack on the but feeder pipe. Dispersion curves of circumferential guided waves were calculated as a function of curvature of the pipe. In the case of thin plate, i. e. infinite curvature, as the frequency increases, the S0 and A0 become to be coincided and eventually Rayleigh wave mode. In the case of pipe, however, as the curvature increases, the lowest modes do not coincide even in the high frequencies. Based on the analysis, a rocking technique using angle beam transducer was applied to detect axial defect in the bent region of PHWR feeder pipe. After review of the experimental data on the artificial notches, the vibration modes of each signal were identified. It was found that the notches with the depth of 10% of wall thickness be detected with the method.

  1. Low cycle fatigue of pressurized pipes with circumferential flaws under cyclic bending moment

    International Nuclear Information System (INIS)

    Pipes of 706 mm inner diameter, 47 mm wall thickness and about 5,000 mm in length were provided with circumferential surface cracks and loaded by internal pressure of 15 MPa whilst being simultaneously subjected to an alternating external bending moment. Usually a load ratio R of -1 (Mmin/Mmax), in one case R = 0.1, was applied. The pipes were fabricated of two types of ferritic steel: one, grade 20 MnMoNi 5 5, with a high upper shelf impact energy of about 200 J and one, MnMoNiV-special melt, with a low upper shelf impact energy of about 60 J. Deformation and crack growth in the wall thickness and circumferential direction were determined and compared with calculated values. 9 refs., 13 figs

  2. A "watch window" technique for monitoring buried free jejunum flaps during circumferential pharyngolaryngectomy reconstruction.

    Science.gov (United States)

    Li, Quan; Zhang, Xin-Rui; Liu, Xue-Kui; Zhang, Zhi-Gang; Liu, Wei-Wei; Li, Hao; Guo, Zhu-Ming

    2012-07-01

    The free jejunum flap approach is the optimal option for circumferential pharyngolaryngectomy reconstruction. In this study, we designed a "watch window" for monitoring buried free jejunum flaps, thereby allowing us to assess graft viability. From 2007 to 2011, 14 patients with hypopharyngeal cancer underwent circumferential pharyngolaryngectomy that was reconstructed using a free jejunum flap at the Sun Yat-sen University Cancer Centre. During the closing of the neck incision, a "watch window" was designed for postoperative monitoring. Two patients experienced thrombosis of the pedicle. One was detected early and successfully rescued by removal of the thrombosis, the other one managed with a second free jejunum flap. The success rate of the buried flaps was 92.9%. No pharyngocutaneous fistulas or strictures occurred. All patients eventually resumed oral feeding and swallowing. The "watch window" technique for monitoring buried free jejunum flaps is simple, reliable and useful for finding vascular problems. Level of evidence Case series. PMID:22116384

  3. Circumferential-wave phase velocities for empty, fluid-immersed spherical metal shells

    DEFF Research Database (Denmark)

    Überall, Herbert; Ahyi, A. C.; Raju, P. K.;

    2002-01-01

    In earlier studies of acoustic scattering resonances and of the dispersive phase velocities of surface waves that generate them [see, e.g., Talmant et al., J. Acoust. Soc. Am. 86, 278–289 (1989) for spherical aluminum shells] we have demonstrated the effectiveness and accuracy of obtaining phase...... results with those calculated from three-dimensional elasticity theory whenever the latter are available. The present investigation is based on the mentioned resonance frequency/elasticity theory connection, and we obtain comparative circumferential-wave dispersion-curve results for water......-loaded, evacuated spherical metal shells of aluminum, stainless steel, and tungsten carbide. In particular, the characteristic upturn of the dispersion curves of low-order shell-borne circumferential waves (A or A0 waves) which takes place on spherical shells when the frequency tends towards very low values, is...

  4. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats

    OpenAIRE

    Takano, Hiroshi; ISOGAI, Tomomi; Aoki, Takuma; WAKAO, Yoshito; Fujii, Yoko

    2014-01-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM...

  5. Circumferential mucosal dissection and esophageal perforation in a patient with eosinophilic esophagitis

    OpenAIRE

    Liguori, Gennaro; Cortale, Maurizio; Cimino, Fabrizio; Sozzi, Michele

    2008-01-01

    A young man with a previous history of episodes of mild solid food dysphagia was admitted with a total dysphagia. The esophagogastroduodenoscopy (EGDS) showed an extensive disruption of mucosal layer with a cul-de-sac in the lower part of the esophagus. Soon after the procedure, the patient suffered from an acute chest pain and subsequent CT scan demonstrated an intramural circumferential dissection of thoracic esophagus, and a mediastinal emphysema. An emergency right thoracotomy was perform...

  6. Circumferential profiles for region-based analysis of dynamic SPECT data

    International Nuclear Information System (INIS)

    Kinetic parameters (washin, washout) of dynamic SPECT teboroxime data sets may provide a more sensitive measure of coronary artery disease than conventional (Tl, MIBI) static myocardial perfusion studies. A time-consuming and subjective step of the data analysis is drawing regions of interest to delineate blood pool and myocardial tissue regions. The time-activity curves for the regions are then used to estimate local kinetic parameters. In this work, the appropriate time-activity curves are found automatically, in a manner similar to that used for calculating circumferential profiles in conventional static cardiac studies. The drawbacks to applying standard static circumferential profile methods are the high noise level and high liver uptake common in dynamic studies. Searching along each ray for maxima to locate the myocardium does not always provide useful information. Here we propose an iterative scheme in which constraints are imposed on the radii searched. The constraints are based on the shape of the time-activity curve of the circumferential profile members and on an assumption that the short axis slices are approximately circular. The constraints eliminate outliers and help to reduce the effects of the noise and the liver activity. Kinetic parameter estimates from the automatically generated regions were comparable to estimates from manually selected regions in canine dynamic teboroxime studies

  7. Exact solutions for the vibration of circumferentially stepped orthotropic circular cylindrical shells

    Science.gov (United States)

    Khalifa, Ahmed Mousa

    2011-11-01

    The combination of Flügge's shell theory, the transfer matrix approach and the Romberg integration method are used to investigate the free vibration behaviour of stepped orthotropic cylindrical shells. The hoop step on the shell surface is described by a reduced thickness over part of its circumference. Modal displacements of the shell can be described by trigonometric functions and Fourier's approach is used to separate the variables. The vibration equations of the shell are reduced to eight first-order differential equations in the circumferential coordinate, and by using the transfer matrix of the shell, these equations can be written in a matrix differential equation. The transfer matrix is derived from the non-linear differential equations of the cylindrical shells by introducing the trigonometric functions in the longitudinal direction and applying the numerical integration in the circumferential direction. The proposed model is used to get the vibration frequencies and the corresponding mode shapes for symmetrical and antisymmetrical type-modes. Computed results indicate the sensitivity of the frequency parameters and the bending deformations to the geometry of stepped shell, and also to the axial and circumferential rigidities of the shell.

  8. Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

    Directory of Open Access Journals (Sweden)

    Qing Wei Li

    2015-01-01

    Full Text Available A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by the finite element method. At last, the oxide scale thickness and stress sensors are established on support vector machine (SMV optimized by particle swarm optimization (PSO with time and circumferential angles as inputs and oxide scale thickness and stress as outputs. Temperature and stress calculation methods are validated by the operation data and experimental data, respectively. The soft sensor is applied to the superheater tubes of some power plant. Results show that the soft sensor can give enough accurate results for oxide scale thickness and stress in reasonable time. The forecasting model provides a convenient way for the research of the oxide scale failure.

  9. Scalp ulceration from a circumferential head dressing after craniotomy: Case report of an uncommon complication due to human error

    OpenAIRE

    Singhal, Ashutosh; Bray, Peter W.; Bernstein, Mark

    2004-01-01

    The present paper describes a previously unpublished complication of the application of a circumferential head dressing after cranial neuro-surgery. A 34-year-old woman developed a large area of skin necrosis on her forehead from a circumferential head dressing applied after the surgical removal of a colloid cyst. Neurological recovery was excellent but plastic surgical repair of her iatrogenic cosmetic injury was required.

  10. Clinical implication of negative conversion of predicted circumferential resection margin status after preoperative chemoradiotherapy for locally advanced rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nam Kwon [Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul (Korea, Republic of); Kim, Chul Yong, E-mail: kcyro@korea.ac.kr [Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul (Korea, Republic of); Park, Young Je; Yang, Dae Sik; Yoon, Won Sup [Department of Radiation Oncology, Korea University Medical Center, Korea University College of Medicine, Seoul (Korea, Republic of); Kim, Seon Hahn; Kim, Jin [Division of Colorectal Surgery, Department of Surgery, Korea University Medical Center, Korea University College of Medicine, Seoul (Korea, Republic of)

    2014-02-15

    Objective: To evaluate the prognostic implication of the negative conversion of predicted circumferential resection margin status before surgery in patients with locally advanced rectal cancer with predicted circumferential resection margin involvement. Methods: Thirty-eight patients (28 men, 10 women; median age, 61 years; age range, 39–80 years) with locally advanced rectal cancer with predicted circumferential resection margin involvement who underwent preoperative chemoradiotherapy followed by radical surgery were analyzed. Involvement of the circumferential resection margin was predicted on the basis of pre- and post-chemoradiotherapy magnetic resonance imaging. The primary endpoints were 3-year local recurrence-free survival and overall survival. Results: The median follow-up time was 41.1 months (range, 13.9–85.2 months). The negative conversion rate of predicted circumferential resection margin status after preoperative chemoradiotherapy was 65.8%. Patients who experienced negative conversion of predicted circumferential resection margin status had a significantly higher 3-year local recurrence-free survival rate (100.0% vs. 76.9%; P = 0.013), disease-free survival rate (91.7% vs. 59.3%; P = 0.023), and overall survival rate (96.0% vs. 73.8%; P = 0.016) than those who had persistent circumferential resection margin involvement. Conclusions: The negative conversion of the predicted circumferential resection margin status as predicted by magnetic resonance imaging will assist in individual risk stratification as a predictive factor for treatment response and survival before surgery. These findings may help physicians determine whether to administer more intense adjuvant chemotherapy or change the surgical plan for patients displaying resistance to preoperative chemoradiotherapy.

  11. Percutaneous kyphoplasty combined with the posterior screw-rod system in treatment of osteoporotic thoracolumbar fractures

    Directory of Open Access Journals (Sweden)

    Jiang Wu

    2013-01-01

    Materials and Methods: Twenty six patients (65 years of age or older with the single spine fractures included in study. The preoperative bone mineral density was measured by dual-energy X-ray. The PKP was done in all the cases. Decompression was done if neurological symptoms were present. Results: The results demonstrated osteoporosis with BMD T value ≤ −2.5; injured posterior vertebral body (3 cases had shown the whole damage accompanied by neurological symptoms through X-ray or CT. After 2 days, the remaining patients of back pain symptoms were relieved or disappeared except for three cases of patients with decompression incision. VAS score and Cobb angle changed from preoperative 8.23 ± 0.17 and 28.7 ± 0.33° respectively to postoperative 3.77 ± 0.44 and 3.8 ± 0.2° respectively. Conclusion: Treatment of rupture of the posterior vertebral osteoporotic thoracolumbar fractures by means of kyphoplasty combined with posterior screw-rod system is a safe, effective procedure.

  12. Gradual Height Decrease of Augmented Vertebrae after Vertebroplasty at the Thoracolumbar Junction

    Science.gov (United States)

    Oh, Han San; Kim, Hyun Gon; Park, Kwan Ho

    2016-01-01

    Objective Vertebroplasty is an effective treatment for vertebral compression fracture, but may progress gradual vertebral height decrease in spite of vertebroplasty. Gradual vertebral height decrease also may induce aggravation of kyphotic change without severe pain. The purpose of this study was to evaluate risk factors for gradual vertebral height decrease in the absence of recurrent severe back pain. Methods A retrospective analysis was performed on 44 patients who were diagnosed with a first osteoporotic compression fracture at a single level at the thoracolumbar junction. All patients were taken vertebroplasty. Possible risk factors for gradual vertebral height decrease, such as sex, age, bone mineral density, body mass index, level of compression fracture, volume of injected cement, cement leakage into disc space, and air clefts within fractured vertebrae, were analyzed. Results Gradual vertebral height decrease of augmented vertebrae occurred commonly when more than 4 cc of injected cement was used, and when air clefts within fractured vertebrae were seen on admission. In addition, the sagittal Cobb angle more commonly increased during the follow-up period in such cases. Conclusion Injection of more than 4 cc of cement during vertebroplasty and air cleft within fractured vertebrae on admission induced gradual vertebral height decrease in augmented vertebrae. Thus, longer follow-up will be needed in such cases, even when patients do not complain of recurrent severe back pain.

  13. Burst fracture of the thoracolumbar spine: correlation between kyphosis and clinical result of the treatment

    Directory of Open Access Journals (Sweden)

    Rodrigo Arnold Tisot

    2015-06-01

    Full Text Available OBJECTIVE: To evaluate the correlation between kyphosis due to burst fractures of thoracic and lumbar spine and clinical outcome in patients undergoing conservative or surgical treatment.METHODS: A retrospective, cross-sectional study was conducted with 29 patients with thoracolumbar burst fractures treated by the Spine Group in a trauma reference hospital between the years 2002 and 2011. Patients were followed-up as outpatients for a minimum of 24 months. All cases were clinically evaluated by Oswestry and SF-36 quality of life questionnaires and the visual analogue scale (VAS of pain. They were also evaluated by X-ray examinations and CT scans of the lumbosacral spine at the time of hospitalization and subsequently as outpatients by Cobb method for measuring the degree of kyphosis.RESULTS: There was no statistically significant correlation between the degree of initial kyphosis and clinical outcome measured by VAS and by most of the SF-36 domains in both patients treated conservatively and the surgically treated. The Oswestry questionnaire showed benefits for patients who received conservative treatment (p=0.047 compared to those surgically treated (p=0.335. The analysis of difference between initial and final kyphosis and final kyphosis alone in relation to clinical outcome showed no statistical correlation in any of the scores used.CONCLUSION: The clinical outcome of treatment of the thoracic and lumbar burst fractures was not influenced by a greater or lesser degree of initial or residual kyphosis, regardless of the type of treatment.

  14. Clinical and radiological outcomes of conservative treatment after stable post-traumatic thoracolumbar fractures in elderly: Is it really best option for all elderly patients?

    Directory of Open Access Journals (Sweden)

    Deniz Cankaya

    2015-12-01

    Conclusion: Although there is wide acceptance of conservative treatment of post-traumatic stable thoracolumbar fracture with intact PCL according to the Thoracolumbar Injury Classification and Severity Score (TLICS, elderly female patients with a post-traumatic compression fracture in the junctional region are at great risk of conservative treatment failure. These patients should be well-informed about the possible complications and poor results of conservative treatment, and surgical treatment should be considered in selective cases with the informed consent of the patients.

  15. Spreading epidural hematoma and deep subcutaneous edema: indirect MRI signs of posterior ligamentous complex injury in thoracolumbar burst fractures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Na Ra [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea); Konkuk University School of Medicine, Department of Radiology, Seoul (Korea); Hong, Sung Hwan [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea); Seoul National University Hospital, Department of Radiology, Seoul (Korea); Choi, Ja-Young; Myung, Jae Sung [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea); Chang, Bong-Soon [Seoul National University College of Medicine, Department of Orthopedic Surgery, Seoul (Korea); Lee, Joon Woo; Kang, Heung Sik [Seoul National University Bundang Hospital, Department of Radiology, Seoul (Korea); Moon, Sung Gyu [Konkuk University School of Medicine, Department of Radiology, Seoul (Korea)

    2010-08-15

    The purpose of this study was to evaluate the diagnostic value of a spreading epidural hematoma (SEH) and deep subcutaneous edema (DSE) as indirect signs of posterior ligamentous complex (PLC) injuries on MR imaging of thoracolumbar burst fractures. We retrospectively reviewed spinal MR images of 43 patients with thoracolumbar burst fractures: 17 patients with PLC injuries (study group) and 26 without PLC injuries (control group). An SEH was defined as a hemorrhagic infiltration into the anterior or posterior epidural space that spread along more than three vertebrae including the level of the fracture. A DSE was regarded as a fluid-like signal lesion in the deep subcutaneous layer of the back, and its epicenter was at the burst fracture level. The frequency of the SEH/DSE in the two groups was analyzed. In addition, the association between each sign and the degree of vertebral collapse, the severity of central canal compromise, and surgical decisions were analyzed. Magnetic resonance images showed an SEH in 20 out of 43 patients (46%) and a DSE in 17 (40%). The SEH and DSE were more commonly seen in the study group with PLC injuries (SEH, 15 out of 17 patients, 80%; DSE, 16 out of 17 patients, 94%) than in the control group without PLC injuries (SEH, 5 out of 26, 19%; DSE, 1 out of 26, 4%) (P <0.0001). The SEH and DSE were significantly associated with surgical management decisions (17 out of 20 patients with SEH, 85%, vs 8 out of the 23 without SEH, 35%, P =0.002; 15 out of 17 with DSE, 88%, vs 10 out of 26 without DSE, 38%, P =0.002). The SEH and DSE did not correlate with the degree of vertebral collapse or the severity of central canal compromise. The SEH and DSE may be useful secondary MR signs of posterior ligamentous complex injury in thoracolumbar burst fractures. (orig.)

  16. An expert consensus on the evaluation and treatment of acute thoracolumbar spine and spinal cord injury in China

    Institute of Scientific and Technical Information of China (English)

    Zhicheng Zhang; Fang Li; Tiansheng Sun

    2013-01-01

    This is an expert consensus on the evaluation and treatment of thoracolumbar spinal injury, estab-lished from February 2009 to July 2010. The expert consensus consists mainly of six parts with a total of 54 recommendations including the overview (one item);pre-hospital care (one item);evalu-ation and diagnosis (13 items);treatment (23 items); prevention and treatment of major complica-tions (12 items);and rehabilitation (four items). This is the first time that Chinese experts have pub-lished a consensus on spine and spinal cord injury. The expert consensus was established based on Delphi methods, literature analysis, and clinical experiences. Each recommendation is supported by and was interpreted using multi-level evidences. The level of agreement with the recommenda-tion among the panel members was assessed as either low, moderate, or strong. Each panel member was asked to indicate his or her level of agreement on a 5-point scale, with “1” corre-sponding to neutrality and“5”representing maximum agreement. Scores were aggregated across the panel members and an arithmetic mean was calculated. This mean score was then translated into low, moderate, or strong. After al of the votes were col ected and calculated, the results showed no low-level recommendations, 10 moderate-level recommendations, and 44 strong-level recom-mendations. An expert consensus was reached and was recognized by Chinese spine surgeons. Wide-scale adoption of these recommendations is urgent in the management of acute thoracol-umbar spine and spinal cord injury in a broader attempt to create a standard evaluation and treat-ment strategy for acute thoracolumbar spine and spinal cord injury in China.

  17. Clinical study on the application of minimally invasive percutaneous pedicle screw fixation in single segment thoracolumbar fracture without neurological symptoms

    Directory of Open Access Journals (Sweden)

    Jin-ping LIU

    2016-04-01

    Full Text Available Objective To discuss the clinical effects of minimally invasive percutaneous pedicle screw fixation in the treatment of single segment thoracolumbar fracture without neurological symptoms.  Methods From June 2012 to October 2014, 38 neurologically intact patients with thoracolumbar fracture underwent surgeries, including open pedicle screw fixation in 16 cases and percutaneous pedicle screw fixation in 22 cases. The incision length, operation time, intraoperative blood loss, postoperative drainage and postoperative complication were recorded and compared between 2 groups. Thoracolumbar orthophoric, lateral and flexion-extension X-ray was used to measure sagittal Cobb angle and height of injured anterior vertebral body before and after operation. Modified Macnab evaluation was used to assess the curative effects 3 months after operation. Results The success rate of operations in 38 patients was 100%. There were a total of 114 vertebral bodies fused and 228 pedicle screws implanted. Patients in the percutaneous pedicle screw group had smaller incision length [(10.55 ± 1.23 cm vs (18.50 ± 2.50 cm, P = 0.000], less intraoperative blood loss [(32.55 ± 7.22 ml vs (320.50 ± 15.48 ml, P = 0.000], shorter hospital stay [(6.55 ± 1.50 d vs (13.50 ± 2.52 d, P = 0.000], and without postoperative drainage. The follow-up after operation ranged from 3 to 6 months, with the average time of (4.65 ± 1.24 months. Cobb angle was reduced (P = 0.000 and height of injured anterior vertebral body were improved signifcantly (P = 0.000 3 months after surgery in both groups. The total effective rate was 14/16 in open surgery group, and 86.36% (19/22 in percutaneous pedicle screw group, however, the difference between 2 groups was not significant (P = 1.000. Conclusions Minimally invasive percutaneous pedicle screw fixation is a surgical method with less iatrogenic injury, less intraoperative blood loss and quick recovery for patients with thoracolumbar fracture

  18. Posterior-Only Circumferential Decompression and Reconstruction in the Surgical Management of Lumbar Vertebral Osteomyelitis.

    Science.gov (United States)

    Skovrlj, Branko; Guzman, Javier Z; Caridi, John; Cho, Samuel K

    2016-02-01

    Study Design Case report. Objective The purpose of this report is to discuss the surgical management of lumbar vertebral osteomyelitis with a spinal epidural abscess (SEA) and present a single-stage, posterior-only circumferential decompression and reconstruction with instrumentation using an expandable titanium cage and without segmental nerve root sacrifice as an option in the treatment of this disease process. Methods We report a 42-year-old man who presented with 3 days of low back pain and chills who rapidly decompensated with severe sepsis following admission. Magnetic resonance imaging of his lumbosacral spine revealed intramuscular abscesses of the left paraspinal musculature and iliopsoas with SEA and L4 vertebral body involvement. The patient failed maximal medical treatment, which necessitated surgical treatment as a last resort for infectious source control. He underwent a previously undescribed procedure in the setting of SEA: a single-stage, posterior-only approach for circumferential decompression and reconstruction of the L4 vertebral body with posterior segmental instrumented fixation. Results After the surgery, the patient's condition gradually improved; however, he suffered a wound dehiscence necessitating a surgical exploration and deep wound debridement. Six months after the surgery, the patient underwent a revision surgery for adjacent-level pseudarthrosis. At 1-year follow-up, the patient was pain-free and off narcotic pain medication and had returned to full activity. Conclusion This patient is the first reported case of lumbar osteomyelitis with SEA treated surgically with a single-stage, posterior-only circumferential decompression and reconstruction with posterior instrumentation. Although this approach is more technically challenging, it presents another viable option for the treatment of lumbar vertebral osteomyelitis that may reduce the morbidity associated with an anterior approach. PMID:26835214

  19. Investigations on an Axial Flow Fan Stage subjected to Circumferential Inlet Flow Distortion and Swirl

    Institute of Scientific and Technical Information of China (English)

    M.Govardhan; K.Viswanath

    1997-01-01

    The combined effects of swirl and circumferential inlet flow distortion on the flow field of an axial flow fan stage are reported in this paper,The study involves measurements at the inlet of the rotor and exit of the rotor and stator atdesign and off design flow conditions.The study indicated that at the design flow condition,swirl had caused deterioration of the performance in addition to that caused by distortion.Pressure rise imparted in the distortion zone is hogher than in the free zone.The attenuation of distortion is high in the presence of swirl.

  20. Fracture toughness evaluation using circumferential notched tensile specimens by the tensile test and ANSYS software

    International Nuclear Information System (INIS)

    Fracture toughness (KIc ) is the most important parameter that defines mechanical behaviour of the materials using machine design. Since, fracture tests are both difficult and time consuming, the researchers have been investigating for the easier evaluation of KIc for many years. In this work; KIc values have been obtained by using ANSYS software based on the experimental values evaluated in the previous studies. It was shown that there is no significant difference between the experimental ones and the ones obtained by ANSYS. This procedure can provide an important advantage on obtaining of the KIC values. Key words: Fracture toughness (KIc ), circumferential notched tensile specimens, ANSYS

  1. Circumferential skin folds in a child: A case of Michelin tire baby syndrome

    Directory of Open Access Journals (Sweden)

    Palit Aparna

    2007-01-01

    Full Text Available A six-month-old girl who presented with dermatitis was found to have multiple, symmetric, deep, gyrate skin folds involving her trunk and similar circumferential lesions on her extremities since birth. She had a characteristic round face with hypertelorism, depressed nasal bridge, thin, down-turned vermillion border of upper lip and short neck. Skin biopsy demonstrated increased smooth muscle fibers in the deeper dermis. A diagnosis of Michelin tire baby syndrome was made. Clinical features, histopathology, differential diagnosis and prognosis of this rare disorder have been discussed.

  2. Geometric characterization of a circumferential seam by automatic segmentation of digitized radioscopic images

    International Nuclear Information System (INIS)

    The present study deals with the nondestructive control of a circumferential seam by digital radioscopy. A series of images for one complete revolution of the welded component is available. We first resort to a joint approach by simulation and experimentation. This approach allows the detection of the molten zone limits for an initial image. We then develop a segmentation method that permits automatic extraction of the geometric characteristics of the set of images representative of the weld. These measures supply fast and automatic control of the weld quality. Results are shown for real components. (author)

  3. Application of statically indeterminate fracture mechanics, SIFM, to a circumferentially cracked cylinder problem

    International Nuclear Information System (INIS)

    The method of Statically Indeterminate Fracture Mechanics called SIFM is an application of elastic-plastic fracture mechanics to statically indeterminate problems. Application of SIFM has been developed for axially cracked cylinder problems. Its application was modified to a circumferentially cracked cylinder. The component might be loaded by combined transient thermal and mechanical loading. This was applied to simulate pressurized thermal shock, PTS, experiment, NKS-3, carried out by MPA. The predicted result from SIFM shows good agreement with the NKS-3 experimental one. (orig.)

  4. Inner wall inspection of steam generator tubes with circumferential welds using ultrasonic crack detection

    International Nuclear Information System (INIS)

    Cracks in the neighbourhood of circumferential welds at the inside of generator tubes to the weld seam can be detected with an ultrasonic probe system using Rayleigh's surface waves. A reference reflector with about 0.5 mm in depth and 1.5 mm in length is used. The ultrasonic inspection system is using a rotating mirror with two faces which can detect cracks on both sides of the weld and which can clearly separate crown or root indications from real defects. The signal-to-noise ratio is better than 12 dB. The system and results on tubes with artificial and real test reflectors are described

  5. Inner wall inspection of steam generator tubes with circumferential welds using ultrasonic crack detection

    International Nuclear Information System (INIS)

    Cracks in the neighbourhood of circumferential welds at the inside of generator tubes to the weld seam can be detected with an ultrasonic probe system using Rayleigh's surface waves. A reference reflector with about 0.5 mm in depth and 1.5 mm in length is used. The ultrasonic inspection system is using a rotating mirror with two faces which can detect cracks on both sides of the weld and which can clearly separate crown or root indications from real defects. The signal-to-noise ratio is better than 12 dB. The system and results on tubes with artificial and real test reflectors are described. 8 refs

  6. One-stage posterior debridement, bone grafting and internal fixation for thoracolumbar spinal tuberculosis%一期后路病灶清除植骨融合内固定治疗胸腰椎结核

    Institute of Scientific and Technical Information of China (English)

    任之强; 丁金勇; 晋大祥; 庄洪; 万梓成

    2014-01-01

    Objective To evaluate the clinical efficacy of one-stage posterior debridement, bone grafting and internal fixation for thoracolumbar spinal tuberculosis.Methods From January 2010 to June 2012,28 patients with thoracolumbar spinal tuberculosis undergoing one-stage posterior debridement, bone grafting and internal fixation procedure were reviewed retrospectively .All cases were followed up.The kyphosis Cobb’s angle, erythrocyte sedimentation rate (ESR), C-reaction protein (CRP), bone fusion and American Spinal Injury Association (ASIA) grade before and after surgery were reviewed and compared.Results The median peri-od of follow-up was 1.2 years.There was no significant loss of kyphosis Cobb’s angle after operation.The average kyphosis Cobb’s angle was corrected 4.12 °, the average correction rate was 24.5%.The ESR and CRP levels returned to normal at final follow-up. The majority of bony fusion was achieved within 7.8 months.Most of the original symptoms disappeared.According to ASIA grade, the neurological function was improved after operation.Conclusion Treatments with one-stage posterior debridement, bone grafting and internal fixation for thoracolumbar spinal tuberculosis can effectively achieve debridement, spinal cord decompression, correc-tion of spinal kyphosis, reconstruction of spinal stability.%目的:探讨一期后路病灶清除植骨融合内固定治疗胸腰椎结核的临床疗效。方法回顾性分析2010年1月~2012年6月本院采用一期后路病灶清除植骨融合内固定治疗的28例胸腰椎结核患者的临床资料,对比研究患者手术前后患椎后凸Cobb角、红细胞沉降率( erythrocyte sedimentation rate, ESR)、C 反应蛋白( C-reaction protein, CRP)、植骨融合及美国脊髓损伤协会( American Spinal Injury Association, ASIA)分级变化情况。结果28例获得随访,平均随访1.2年,术后Cobb角无明显丢失,后凸畸形平均纠正4.12°,平均矫正率24

  7. Dose-Volume Effects in Rat Thoracolumbar Spinal Cord: The Effects of Nonuniform Dose Distribution

    International Nuclear Information System (INIS)

    Purpose: To investigate dose-volume effects in rat spinal cord irradiated with nonuniform dose distributions and to assess regional differences in radiosensitivity. Methods and Materials: A total of 106 rats divided into three groups were irradiated with 192Ir γ-rays at a high dose rate. The groups were irradiated with one, two, or six catheters distributed around the thoracolumbar spinal cord to create different dose distributions. After irradiation, the animals were tested for motor function for 9 months. The response was defined as motor dysfunction and WM or nerve root necrosis. Dose-response data were analyzed with a probit analysis as function of the dose level at a percentage of the volume (D%) and with different normal tissue complication probability models. Additionally, the histologic responses of the individual dose voxels were analyzed after registration with the histologic sections. Results: The probit analysis at D24 (24% of the volume) gave the best fit results. In addition, the Lyman Kutcher Burman model and the relative seriality model showed acceptable fits, with volume parameters of 0.17 and 0.53, respectively. The histology-based analysis revealed a lower radiosensitivity for the dorsal (50% isoeffective dose [ED50] = 32.3) and lateral WM (ED50 = 33.7 Gy) compared with the dorsal (ED50 = 25.9 Gy) and ventral nerve roots (ED50 = 24.1 Gy). Conclusions: For this nonuniform irradiation, the spinal cord did not show typical serial behavior. No migration terms were needed for an acceptable fit of the dose-response curves. A higher radiosensitivity for the lumbar nerve roots than for the thoracic WM was found

  8. Evaluation the results of surgical management of traumatic paraplegia in traumatic thoracolumbar fractures

    Directory of Open Access Journals (Sweden)

    Subarna Misra

    2016-06-01

    Full Text Available Background: Thoracolumbar spine fractures are common injuries that can result in significant disability, deformity and neurological deficit. Aim of this study was to evaluate the results of surgical management of traumatic paraplegia, complete or incomplete as classified by Frankel scoring. Methods: A prospective study was conducted in patients attending outdoor and emergency department of Orthopedics of a tertiary care teaching institute in Kolkata, West Bengal with traumatic paraplegia involving the dorsolumbar spine. The important objectives are the time for recovery of various functions like sensory, motor and bowel and bladder function, comparison between early and late decompression, results of posterolateral fusion and time taken for solid bony fusion after operation. Total 46 cases were selected within a minimum of 6-month post-operative follow-up of which 4 cases lost in follow-up. Data collected from patient records included age, sex, time from injury to hospitalization, initial neurological status as per Frankel Score, MRI findings, surgery performed, postoperative course and neurological status at the time of discharge and latest follow up. Patients lost to follow up were not studied for outcome analysis. Results: When decompression done within 1st week in incomplete paraplegia, 80% of the patients showed return of grade 3 power. In complete paraplegia cases, 11% of the patients had return of power up to grade 3 when decompression done within 1 week, where no cases showed return of grade 3 power when decompression done after 2nd or 3rd week. Conclusions: After recovery from spinal shock, the earlier the surgical compression done, the better the neurological and bowel/bladder function recovery both in complete and incomplete paraplegic cases. Reduction is better and easy and less time consuming in early decompression than in late. Motor recovery can continue for over 6 months after decompression. [Int J Res Med Sci 2016; 4(6.000: 2262-2270

  9. MORPHOMETRIC AND MORPHOLOGICAL STUDY OF ARTICULAR FACETS OF THE THORACOLUMBAR VERTEBRAL COLUMN IN NORTH INDIAN POPULATION

    Directory of Open Access Journals (Sweden)

    Rimpi Gupta

    2015-09-01

    Full Text Available Background: The articular processes of thoracolumbar vertebral column play an important role in weight transmission and determining the range and direction of movements between any two vertebrae. Size of these facets has been correlated with the magnitude of stress imposed on them. Purpose of study: The present study has been conducted on the articular processes of 510 vertebrae (thoracic: 360; lumbar:150 with the aim to provide high quality data sets for constructing the models of spine to study mechanics of spinal instrumentation. The length , width and the distance between the right & left superior & inferior articular processes have been measured with the vernier callipers. The presence/ absence of mamillary tubercle has been observed in the present study. Results: The length of thoracic SAFs was almost same at all levels whereas that of the lumbar SAFs increased gradually from L1-L5. However the width showed a variable trend. In case of thoracic IAFs both these parameters showed a variable trend. Whereas in lumbar region, these increased gradually from L1-L5. The distance between two inferior articular processes was more than that between two superior articular processes at almost all levels except T1-T3 & L1-L4 where reverse was true. The mamillary tubercle/process was altogether absent from T-1 to T-8. From T-9 to T-11, the number of vertebral column showing mamillary tubercle increased from 4-19. However at T-12, it was seen in 29 Vertebral columns. In lumbar region, it was well developed in all vertebrae and termed as mamillary process. Conclusion: The measurements obtained by present study reveals the importance of articular facets in understanding basic spinal mechanics and its application with respect to weight transmission.

  10. Effects of inlet circumferential fluctuation on the sweep aerodynamic performance of axial fans/compressors

    Science.gov (United States)

    Gui, Xingmin; Zhu, Fang; Wan, Ke; Jin, Donghai

    2013-10-01

    Swept blades have been widely used in the transonic fan/compressor of aircraft engines with the aids of 3D CFD simulation since the design concept of controlling the shock structure was firstly proposed and successfully tested by Dr. Wennerstrom in the 1980s. However, some disadvantage phenomenon has also been induced by excessively 3D blade geometries on the structure stress insufficiency, vibration and reliability. Much confusion in the procedure of design practice leading us to recognize a new view on the flow mechanism of sweep aerodynamical induction: the new radial equilibrium established by the influence of inlet circumferential fluctuation (CF) changes the inlet flows of blading and induces the performance modification of axial fans/compressors blade. The view is verified by simplified models through numerical simulation and circumferentially averaged analysis in the present paper. The results show that the CF source items which originate from design parameters, such as the spanwise distributions of the loading and blading geometries, contribute to the changing of averaged incidence spanwise distribution, and further more affect the performance of axial fans/compressors with swept blades.

  11. Effects of circumferential rigid wrist orthoses in rehabilitation of patients with radius fracture at typical site

    Directory of Open Access Journals (Sweden)

    Đurović Aleksandar

    2005-01-01

    Full Text Available Background. The use of orthoses is a questionable rehabilitation method for patients with the distal radius fracture at typical site. The aim of this study was to compare the effects of the rehabilitation on patients with radius fracture at the typical site, who wore circumferential static wrist orthoses, with those who did not wear them. Methods. Thirty patients were divided into 3 equal groups, 2 experimental groups, and 1 control group. The patients in the experimental groups were given the rehabilitation program of wearing serially manufactured (off-the-shelf, as well as custom-fit orthoses. Those in the control group did not wear wrist orthoses. Evaluation parameters were pain, edema, the range of the wrist motion, the quality of cylindrical, spherical, and pinch-spherical grasp, the strength of pinch and hand grasp, and patient's assessment of the effects of rehabilitation. Results. No significant difference in the effects of rehabilitation on the patients in experimental groups as opposed to control group was found. Patients in the first experimental group, and in control group were more satisfied with the effects of rehabilitation, as opposed to the patients in the second experimental group (p<0,05. Conclusion. The effects of circumferential static wrist orthoses in the rehabilitation of patients with distal radius fracture at the typical site were not clinically significant. There was no significant difference between the custom and off-the-shelf orthoses.

  12. COMPUTATIONAL AND EXPERIMENTAL STUDY ON TIP LEAKAGE VORTEX OF CIRCUMFERENTIAL SKEWED BLADES

    Institute of Scientific and Technical Information of China (English)

    LI Yang; OUYANG Hua; DU Zhaohui

    2007-01-01

    In the steady operation condition, the experiments and the numerical simulations are used to investigate the tip leakage flow fields in three low pressure axial flow fans with three kinds of circumferential skewed rotors, including the radial rotor, the forward-skewed rotor and the backward-skewed rotor. The three-dimensional viscous flow fields of the fans are computed. In the experiments, the two-dimensional plane particle image velocimetry (PIV) system is used to measure the flow fields in the tip region of three different pitchwise positions of each fan. The results show that the computational results agree well with the experimental data in the flow field of the tip region of each fan. The tip leakage vortex core segments based on method of the eigenmode analysis can display clearly some characteristics of the tip leakage vortex, such as the origination position of tip leakage vortex, the development of vortex strength, and so on. Compared with the radial rotor, the other two skewed rotors can increase the stability of the tip leakage vortex and the increment in the forward-skewed rotor is more than that in the backward-skewed one. Among the tip leakage vortices of the three rotors, the velocity of the vortex in the forward-skewed rotor is the highest in the circumferential direction and the lowest in the axial direction.

  13. Fragmentation of calcified plaque after carotid artery stenting in heavily calcified circumferential stenosis

    Energy Technology Data Exchange (ETDEWEB)

    Tsutsumi, Masanori; Kodama, Tomonobu; Aikawa, Hiroshi; Onizuka, Masanari; Iko, Minoru; Nii, Kouhei; Hamaguchi, Shuko; Etou, Housei; Sakamoto, Kimiya; Inoue, Ritsurou; Nakau, Hiroya [Fukuoka University Chikushi Hospital, Department of Neurosurgery and Neuroradiology, Fukuoka (Japan); Kazekawa, Kiyoshi [Fukuoka University Chikushi Hospital, Department of Neurosurgery and Neuroradiology, Fukuoka (Japan); Fukuoka University Chikushi Hospital, Department of Neurosurgery, Fukuoka (Japan)

    2010-09-15

    We assessed the morphological change of calcified plaque after carotid artery stenting (CAS) in vessels with heavily calcified circumferential lesions and discuss the possible mechanisms of stent expansion in these lesions. We performed 18 CAS procedures in 16 patients with severe carotid artery stenosis accompanied by plaque calcification involving more than 75% of the vessel circumference. All patients underwent multidetector-row computed tomography (MDCT) to evaluate lesion calcification before and within 3 months after intervention. The angiographic outcome immediately after CAS and follow-up angiographs obtained 6 months post-CAS were examined. The preoperative mean arc of the calcifications was 320.1 {+-} 24.5 (range 278-360 ). In all lesions, CAS procedures were successfully carried out; excellent dilation with residual stenosis {<=}30% was achieved in all lesions. Post-CAS MDCT demonstrated multiple fragmentations of the calcifications in 17 of 18 lesions (94.4%), but only cracks in the calcified plaque without fragmentation in one (5.6%). Angiographic study performed approximately 6 months post-CAS detected severe restenosis in one lesion (5.6%) without fragmentation of calcified plaque. Excellent stent expansion may be achieved and maintained in heavily calcified circumferential carotid lesions by disruption and fragmentation of the calcified plaques. (orig.)

  14. Fragmentation of calcified plaque after carotid artery stenting in heavily calcified circumferential stenosis

    International Nuclear Information System (INIS)

    We assessed the morphological change of calcified plaque after carotid artery stenting (CAS) in vessels with heavily calcified circumferential lesions and discuss the possible mechanisms of stent expansion in these lesions. We performed 18 CAS procedures in 16 patients with severe carotid artery stenosis accompanied by plaque calcification involving more than 75% of the vessel circumference. All patients underwent multidetector-row computed tomography (MDCT) to evaluate lesion calcification before and within 3 months after intervention. The angiographic outcome immediately after CAS and follow-up angiographs obtained 6 months post-CAS were examined. The preoperative mean arc of the calcifications was 320.1 ± 24.5 (range 278-360 ). In all lesions, CAS procedures were successfully carried out; excellent dilation with residual stenosis ≤30% was achieved in all lesions. Post-CAS MDCT demonstrated multiple fragmentations of the calcifications in 17 of 18 lesions (94.4%), but only cracks in the calcified plaque without fragmentation in one (5.6%). Angiographic study performed approximately 6 months post-CAS detected severe restenosis in one lesion (5.6%) without fragmentation of calcified plaque. Excellent stent expansion may be achieved and maintained in heavily calcified circumferential carotid lesions by disruption and fragmentation of the calcified plaques. (orig.)

  15. Transmit-receive eddy current probes for circumferential cracks in heat exchanger tubes

    International Nuclear Information System (INIS)

    Conventional eddy current bobbin probes are known to be ineffectual in detecting circumferential cracks in tubing. Multi-pancake and/or rotating pancake probes are required to detect circumferential cracks. It has recently been demonstrated in CANDU steam generator tubes, with deformation, ferromagnetic deposits, and copper deposits, that multi-channel probes with transmit-receive (T/R) coils are superior to those using surface impedance coils. Unlike rotating probes, the design of a new probe denoted as C3 permits fast, single-scan inspection of a full-length tube at inspection speeds comparable to conventional bobbin probes. Since 1992, the probe has been used routinely for steam generator in-service inspection at 4 CANDU plants. Defective tubes have been plugged and the units returned to service, and they continue to operate without leaks. This paper describes the basic features of T/R surface probes. Two-dimensional voltage diagrams showing computer-derived probe response to frequency, lift-off, carbon steel supports, magnetite deposits and copper deposits are presented and compared with corresponding signals from impedance coils. Theoretical and experimental results show that T/R probes are able to detect defects in the presence of variable lift-off (due to tube-wall deformation) with ten times the signal-to-noise ratio as that exhibited by comparable pancake-type impedance probes. In addition, T/R probes are less sensitive to magnetite deposits, and possess good phase discrimination to internal defects

  16. Status of the steam generator tube circumferential ODSCC degradation experienced at the Doel 4 plant

    Energy Technology Data Exchange (ETDEWEB)

    Roussel, G. [AIB-Vincotte Nuclear, Brussels (Belgium)

    1997-02-01

    Since the 1991 outage, the Doel Unit 4 nuclear power plant is known to be affected by circumferential outside diameter intergranular stress corrosion cracking at the hot leg tube expansion transition. Extensive non destructive examination inspections have shown the number of tubes affected by this problem as well as the size of the cracks to have been increasing for the three cycles up to 1993. As a result of the high percentage of tubes found non acceptable for continued service after the 1993 in-service inspection, about 1,700 mechanical sleeves were installed in the steam generators. During the 1994 outage, all the tubes sleeved during the 1993 outage were considered as potentially cracked to some extent at the upper hydraulic transition and were therefore not acceptable for continued service. They were subsequently repaired by laser welding. Furthermore all the tubes not sleeved during the 1993 outage were considered as not acceptable for continued service and were repaired by installing laser welded sleeves. During the 1995 outage, some unexpected degradation phenomena were evidenced in the sleeved tubes. This paper summarizes the status of the circumferential ODSCC experienced in the SG tubes of the Doel 4 plant as well as the other connected degradation phenomena.

  17. Elastic-plastic finite element analyses for reducers with constant-depth internal circumferential surface cracks

    International Nuclear Information System (INIS)

    In this study, a 3-D automatic elastic-plastic finite element mesh generator is established to accurately predict the J-integral value of an arbitrary reducer with a constant-depth internal circumferential surface crack under bending and axial force. The contact pairs are used on the crack surfaces to simulate the actual contact behaviors of the crack model under loadings. In order to verify the accuracy of the proposed elastic-plastic finite element model for a reducer with a surface crack, the cracked straight pipe models are generated according to a special modeling procedure for a flawed reducer. The J-integral values along the crack front of surface crack are calculated and compared with the straight pipe models which have been verified in the previous published studies. Based on the comparison of computed results, good agreements are obtained to show the accuracy of present numerical models. More confidence on using the 3-D elastic-plastic finite element analysis for reducers with internal circumferential surface cracks can be thus established in this work

  18. Recent evaluations of crack-opening-area in circumferentially cracked pipes

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, S.; Brust, F.; Ghadiali, N.; Wilkowski, G.; Miura, N.

    1997-04-01

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. The leak rates depend on the crack-opening area of the through-wall crack in the pipe. In addition to LBB analyses which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section XI. The objectives of this study were to review, evaluate, and refine current predictive models for performing crack-opening-area analyses of circumferentially cracked pipes. The results from twenty-five full-scale pipe fracture experiments, conducted in the Degraded Piping Program, the International Piping Integrity Research Group Program, and the Short Cracks in Piping and Piping Welds Program, were used to verify the analytical models. Standard statistical analyses were performed to assess used to verify the analytical models. Standard statistical analyses were performed to assess quantitatively the accuracy of the predictive models. The evaluation also involved finite element analyses for determining the crack-opening profile often needed to perform leak-rate calculations.

  19. Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

    International Nuclear Information System (INIS)

    This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed

  20. Fracture behavior of circumferentially surface-cracked elbows. Technical report, October 1993--March 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kilinski, T.; Mohan, R.; Rudland, D.; Fleming, M. [and others

    1996-12-01

    This report presents the results from Task 2 of the Second International Piping Integrity Research Group (IPIRG-2) program. The focus of the Task 2 work was directed towards furthering the understanding of the fracture behavior of long-radius elbows. This was accomplished through a combined analytical and experimental program. J-estimation schemes were developed for both axial and circumferential surface cracks in elbows. Large-scale, quasi-static and dynamic, pipe-system, elbow fracture experiments under combined pressure and bending loads were performed on elbows containing an internal surface crack at the extrados. In conjunction with the elbow experiments, material property data were developed for the A106-90 carbon steel and WP304L stainless steel elbow materials investigated. A comparison of the experimental data with the maximum stress predictions using existing straight pipe fracture prediction analysis methods, and elbow fracture prediction methods developed in this program was performed. This analysis was directed at addressing the concerns regarding the validity of using analysis predictions developed for straight pipe to predict the fracture stresses of cracked elbows. Finally, a simplified fitting flaw acceptance criteria incorporating ASME B2 stress indices and straight pipe, circumferential-crack analysis was developed.

  1. Uncertainty analysis for the net-section-collapse failure criterion of circumferentially cracked cylinders for multiple arbitrary-shaped circumferential cracks

    International Nuclear Information System (INIS)

    In this manuscript, a generalized net-section-collapse (NSC) failure criterion of circumferentially cracked pipes with multiple arbitrary-shaped cracks is presented. This generalized NSC formulation is capable of predicting the NSC moment of a pipe with multiple arbitrary-shaped cracks distributed around the circumference of the pipe, regardless of whether they are distributed symmetrically or not. The case in which internal cracks straddle the compressive zone is accounted for in the present formulation. Closed form solutions are provided for the maximum moments of pipes containing multiple cracks with idealized shapes, namely constant depth, semi-elliptical and parabolic crack profiles. Through a series of examples, the results show the effectiveness and accuracy of the method. Using this method, quantification of the effect of the crack profile uncertainty on the maximum bending moment sustained by a cracked pipe is evaluated. It is demonstrated that while the uncertainty associated with the surface roughness of the crack profile has little to no effect on the maximum bending moment, irregular shape profiles have, not surprisingly, a large effect on the estimation of the maximum bending moment. In fact, it is mathematically shown that the uncertainty associated with the maximum bending moment is proportional to the magnitude of the crack profile uncertainty and inversely proportional to the square root of the uncertainty sampling size (i.e. surface roughness vs. irregular crack profile)

  2. Percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system: an analysis of 38 cases

    Directory of Open Access Journals (Sweden)

    WANG Hong-wei

    2010-06-01

    Full Text Available To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system in the retrospective non- randomized case-control study.

  3. Epithelioid hemangioendothelioma and multiple thoraco-lumbar lateral meningoceles: two rare pathological entities in a patient with NF-1

    International Nuclear Information System (INIS)

    Epithelioid hemangioendothelioma (EHE) is a rare vascular soft-tissue tumour of intermediate malignancy. Neurofibromatosis type I (NF-1) is a genetic syndrome associated with soft tissue sarcoma and higher risk of developing neoplasia. Lateral meningoceles are uncommon entities, being mostly associated with NF-1. We report a case of a 31-year-old woman, with NF-1 and past history of right thalamic/peduncular astrocytoma WHO grade II, admitted to the Neurosurgery Department in December 2003 due to severe low back pain, irradiating to the left leg without a radicular pattern. Thoraco-lumbar magnetic resonance imaging (MRI) showed a large left posterior paravertebral expansive lesion, bilateral and multiple thoraco-lumbar lateral meningoceles and dural ectasias with scalloping of the vertebral bodies. Biopsy of the paravertebral mass lesion disclosed EHE. We present this case because of the novel association between NF-1 and EHE, and the unusual aggressiveness of the neoplasia. Additionally, we highlight the co-existence of bilateral and multiple lateral meningoceles. (orig.)

  4. Epithelioid hemangioendothelioma and multiple thoraco-lumbar lateral meningoceles: two rare pathological entities in a patient with NF-1

    Energy Technology Data Exchange (ETDEWEB)

    Reis, C.; Carneiro, E.; Fonseca, J.; Salgado, A. [Hospital S. Joao, Departments of Neuroradiology, Porto (Portugal); Pereira, P.; Vaz, R. [Hospital S. Joao, Department of Neurosurgery, Porto (Portugal); Pinto, R. [Hospital S. Joao, Department of Orthopaedics, Porto (Portugal); Capelinha, A.F.; Lopes, J.M. [Hospital S. Joao, Department of Pathology, Porto (Portugal)

    2005-02-01

    Epithelioid hemangioendothelioma (EHE) is a rare vascular soft-tissue tumour of intermediate malignancy. Neurofibromatosis type I (NF-1) is a genetic syndrome associated with soft tissue sarcoma and higher risk of developing neoplasia. Lateral meningoceles are uncommon entities, being mostly associated with NF-1. We report a case of a 31-year-old woman, with NF-1 and past history of right thalamic/peduncular astrocytoma WHO grade II, admitted to the Neurosurgery Department in December 2003 due to severe low back pain, irradiating to the left leg without a radicular pattern. Thoraco-lumbar magnetic resonance imaging (MRI) showed a large left posterior paravertebral expansive lesion, bilateral and multiple thoraco-lumbar lateral meningoceles and dural ectasias with scalloping of the vertebral bodies. Biopsy of the paravertebral mass lesion disclosed EHE. We present this case because of the novel association between NF-1 and EHE, and the unusual aggressiveness of the neoplasia. Additionally, we highlight the co-existence of bilateral and multiple lateral meningoceles. (orig.)

  5. Effects of steroids and angiotensin converting enzyme inhibition on circumferential strain in boys with Duchenne muscular dystrophy: a cross-sectional and longitudinal study utilizing cardiovascular magnetic resonance

    Directory of Open Access Journals (Sweden)

    Kinnett Kathi J

    2011-10-01

    Full Text Available Abstract Background Steroid use has prolonged ambulation in Duchenne muscular dystrophy (DMD and combined with advances in respiratory care overall management has improved such that cardiac manifestations have become the major cause of death. Unfortunately, there is no consensus for DMD-associated cardiac disease management. Our purpose was to assess effects of steroid use alone or in combination with angiotensin converting enzyme inhibitors (ACEI or angiotension receptor blocker (ARB on cardiovascular magnetic resonance (CMR derived circumferential strain (εcc. Methods We used CMR to assess effects of corticosteroids alone (Group A or in combination with ACEI or ARB (Group B on heart rate (HR, left ventricular ejection fraction (LVEF, mass (LVM, end diastolic volume (LVEDV and circumferential strain (εcc in a cohort of 171 DMD patients >5 years of age. Treatment decisions were made independently by physicians at both our institution and referral centers and not based on CMR results. Results Patients in Group A (114 studies were younger than those in Group B (92 studies(10 ± 2.4 vs. 12.4 ± 3.2 years, p cc magnitude was lower in Group B than Group A (-13.8 ± 1.9 vs. -12.8 ± 2.0, p = 0.0004, age correction using covariance analysis eliminated this effect. In a subset of patients who underwent serial CMR exams with an inter-study time of ~15 months, εcc worsened regardless of treatment group. Conclusions These results support the need for prospective clinical trials to identify more effective treatment regimens for DMD associated cardiac disease.

  6. The Mechanism of Stall Margin Improvement in a Centrifugal Compressor with the Air Bleeding Circumferential Grooves Casing Treatment

    Science.gov (United States)

    Gao, P.; Chu, W. L.; Wu, Y. H.

    The air bleeding circumferential grooves casing treatment has the potential to extent the operating range of centrifugal compressor with no loss in efficiency. A time accurate 3-dimentional numerical simulation was performed in a low speed centrifugal compressor with the air bleeding circumferential grooves casing treatment. The numerical results agreed well with experimental test data for the global performance. Detailed analyses of the flow visualization at the tip of blades have exposed the different tip flow topologies between the cases with casing treatment and with untreated smooth wall, and the reasons how the second flow vortex is retrained. The mechanism of stall margin improvement is gained finally.

  7. Subcutaneous fluid collection: An imaging marker for treatment response of infectious thoracolumbar spondylodiscitis

    Energy Technology Data Exchange (ETDEWEB)

    Kakigi, Takahide, E-mail: tkakigi@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Okada, Tomohisa, E-mail: tomokada@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Sakai, Osamu, E-mail: osamu.sakai@bmc.org [Department of Radiology, Boston Medical Center, Boston University School of Medicine, FGH Building, 3rd Floor, 820 Harrison Avenue, Boston, MA 02118 (United States); Iwamoto, Yoshitaka, E-mail: iwacame@hotmail.co.jp [Department of General Internal Medicine, Rakuwakai Otowa Hospital, 2 Otowachoinji-cho, Yamashina-ku, Kyoto 607-8062 (Japan); Kubo, Soichi, E-mail: kubo-s@mbox.kyoto-inet.or.jp [Department of Radiology, Rakuwakai Otowa Hospital, 2 Otowachoinji-cho, Yamashina-ku, Kyoto 607-8062 (Japan); Yamamoto, Akira, E-mail: yakira@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Togashi, Kaori, E-mail: nmdioffice@kuhp.kyoto-ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan)

    2015-07-15

    Highlights: • No imaging marker for treatment response of spondylodiscitis (SD) has been proposed. • Volume changes of subcutaneous fluid collection (SFC) had significant correlation with changes of C-reactive protein (CRP). • SFC can be used as an imaging marker for treatment response of SD on magnetic resonance imaging (MRI). - Abstract: Purpose: To evaluate prevalence of subcutaneous fluid collection (SFC) in infectious thoracolumbar spondylodiscitis (SD) compared with control patients and to investigate correlation between volume changes of SFC and treatment response of SD. Materials and methods: This retrospective study was approved by our institutional review board. From April 2011 to March 2012, 49 patients (24 SD and 25 non-SD patients) were enrolled. Prevalence of SFC was evaluated respectively for SD and non-SD patients using magnetic resonance imaging (MRI) on the sagittal short tau inversion recovery (STIR) imaging or fat-saturated T2-weighted imaging (T2WI), and compared. In SD patients with SFC, correlation was investigated between SFC volume on the 1st MRI and initial clinical status. The same analysis was conducted also for SFC volume changes from the 1st to 2nd or last MRI. Results: SFC was found in 20 patients with SD (83.3%) and 3 non-SD patients (12%) with significant difference (p < .001). In 20 SD patients with SFC, 17 patients had follow-up MRI. For the 1st MRI, no significant correlation was found between volume of SFC and initial status of patients, including body weight, body mass index (BMI), white blood cell (WBC), and erythrocyte sedimentation rate (ESR). However, significant positive correlations were found between changes of C-reactive protein (CRP) and SFC volume from the 1st to 2nd as well as from the 1st to the last MRI (each p < .05). Conclusion: SD patients had significantly higher prevalence of SFC than non-SD patients. Volume changes of SFC had significant correlation with changes of CRP, which can be used as an imaging

  8. Failure behaviour of a piping system with a circumferentially orientated flaw

    International Nuclear Information System (INIS)

    The experiments were conducted on the recently installed feedwater line of the HDR reactor in Kahl. The investigations were focused on analysing both the crack propagation of a circumferentially flowed pipe under the influence of corrosion and cyclic load, together with the pipeline's subsequent failure behaviour. The experimental conditions were selected in a manner representing those which can, for example, prevait during start-up or shut-down of reactor. To this aim, the pipes were internally stressed with high pressure and temperature oxygenic water in conjunction with an externally applied bending moment. The investigations are supplemented by elastic-plastic triaxial finite element (FE) calculations for various assumed crack configurations, both prior to and following the experiments, thus granting a fracture-mechanical assessment of the structural behaviour. (orig./DG)

  9. Lower bound limit load of a circumferentially cracked pipe under combined mechanical loading

    International Nuclear Information System (INIS)

    In a study on extension of the reference stress method, for J simplified assessment, to a three dimensional (3D) configuration under combined loading, lower bound limit analysis has been developed by J. Desquines. In the present paper the limit load for cracked pipe, with a 3D circumferential flaw, under pressure, tension and bending is detailed. The limit load is explicitly defined as a yield surface is the 3D space loading. A simple algorithm is proposed to solve the non linear problem associated to the reference stress calculation. Moreover, the lower bound solution is compared with elastic compensation method (ECM) results computed on a 3D finite element mesh of the cracked pipe. The lower bound yield surface underestimates the numerical limit loads with a discrepancy lower than 20%. (orig.)

  10. Crack shape developments and leak rates for circumferential complex-cracked pipes

    Energy Technology Data Exchange (ETDEWEB)

    Brickstad, B.; Bergman, M. [SAQ Inspection Ltd., Stockholm (Sweden)

    1997-04-01

    A computerized procedure has been developed that predicts the growth of an initial circumferential surface crack through a pipe and further on to failure. The crack growth mechanism can either be fatigue or stress corrosion. Consideration is taken to complex crack shapes and for the through-wall cracks, crack opening areas and leak rates are also calculated. The procedure is based on a large number of three-dimensional finite element calculations of cracked pipes. The results from these calculations are stored in a database from which the PC-program, denoted LBBPIPE, reads all necessary information. In this paper, a sensitivity analysis is presented for cracked pipes subjected to both stress corrosion and vibration fatigue.

  11. Analysis of parameters likely to explain the secondary side circumferential cracking of steam generator

    International Nuclear Information System (INIS)

    In 1990, a new type of damage mechanism was brought to light by means of eddy current inspections in Steam Generator (SG) tube bundle. This is circumferential cracking, started on the outer wall of the tubes. These cracks generally appear below the level of the tube sheet. By the end of 1993, 89 tubes with this king of damage were discovered in the French nuclear power plants: 85 of these were located on the 6 SG's of 2 units of Dampierre. We present here the work carried out to provide better understanding of this phenomenon. It involves statistical analysis of data from experience feedback, together with analysis of the thermohydraulic conditions found on the tube sheet. (authors). 8 figs., 2 refs

  12. Development of circumferential seal for helicopter transmissions: Results of bench and flight tests

    Science.gov (United States)

    Strom, T. N.; Ludwig, L. P.

    1975-01-01

    A modified circumferential segmented ring seal was designed for direct replacement of a helicopter transmission elastomeric lip seal operating on a shaft diameter of 13.91 centimeters (5.481 in.) at sliding velocities to 52.48 m/sec (10 330 ft/min). The modifications involved the garter spring tension, shaft roundness, seal housing flatness, and pumping grooves to inhibit leakage. Operation of the seals in bench tests under simulated helicopter transmission conditions revealed that the seal leakage rate was within acceptable limits and that the wear rate was negligible. The low leakage and wear rates were confirmed in flight tests of 600 and 175 hours (sliding speed, 48.11 m/sec (9470 ft/min)). An additional 200 hours of air worthiness qualification testing (aircraft tie down) demonstrated that the seal can operate at the advanced sliding conditions of 52.48 m/sec (10 330 ft/min).

  13. Quantitative lymphoscintigraphy in post-mastectomy lymphedema: correlation with circumferential measurements

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon Young; Lee, Kyung Han; Kim, Sang Eun; Kim, Byung Tae; Hwang, Jee Hea; Lee, Byung Boong [Samsung Medical Center, Seoul (Korea, Republic of)

    1997-07-01

    An objective measure for the severity and progression is important for the management of lymphedema. To evaluate the usefulness of lympho-scintigraphy in this regard, we compared various quantitative indices from upper extremity lymphoscintigraphy with circumferential measurements, before and after physiotheraphy. Upper extremity lymphoscintigraphy was performed in 38 patients with unilateral postmastectomy lymphedema. Tc-99m antimony sulfide colloid (37 MBq) was injected s.c. into the second and third interdigital spaces. The injection sites were imaged immediately after injection. After standardized exercise for 15 min, upper extremity images were acquired 30 min, 1 hr and 2 hr after injection. The clearance of the injection site (CL), and % uptake in regional lymph nodes (%LN) and soft tissue of the extremity (i.e., the degree of dermal backflow) (%EXT) compared to the initial injection site were calculated. Circumference of each extremity was measured at 7 levels; the severity of lymphedema was expressed as the percentage difference of total circumferential difference (TCD) between healthy and edematous extremities compared to the total circumference of healthy extremity (%TCD). In 19 patients who received physiotherapy, the therapeutic effect was measured by % decrease of TCD (%DTCD) before and after therapy (Raines. et al., 1977). The quantitative indices calculated in the image at 2 hr p.i. had better correlation with either %TCD or %DTCD than those from earlier images (Table). The CL, %LN and %EXT of edematous extremity had a significant correlation with TCD. The %EXT was correlated best with either TCD or %DTCD. The results suggest that the %EXT which corresponds to the degree of dermal backflow may be a simple and useful quantitative index for evaluating the severity and progression in lymphedema and predicting the effect of therapy.

  14. Quantitative lymphoscintigraphy in post-mastectomy lymphedema: correlation with circumferential measurements

    International Nuclear Information System (INIS)

    An objective measure for the severity and progression is important for the management of lymphedema. To evaluate the usefulness of lympho-scintigraphy in this regard, we compared various quantitative indices from upper extremity lymphoscintigraphy with circumferential measurements, before and after physiotheraphy. Upper extremity lymphoscintigraphy was performed in 38 patients with unilateral postmastectomy lymphedema. Tc-99m antimony sulfide colloid (37 MBq) was injected s.c. into the second and third interdigital spaces. The injection sites were imaged immediately after injection. After standardized exercise for 15 min, upper extremity images were acquired 30 min, 1 hr and 2 hr after injection. The clearance of the injection site (CL), and % uptake in regional lymph nodes (%LN) and soft tissue of the extremity (i.e., the degree of dermal backflow) (%EXT) compared to the initial injection site were calculated. Circumference of each extremity was measured at 7 levels; the severity of lymphedema was expressed as the percentage difference of total circumferential difference (TCD) between healthy and edematous extremities compared to the total circumference of healthy extremity (%TCD). In 19 patients who received physiotherapy, the therapeutic effect was measured by % decrease of TCD (%DTCD) before and after therapy (Raines. et al., 1977). The quantitative indices calculated in the image at 2 hr p.i. had better correlation with either %TCD or %DTCD than those from earlier images (Table). The CL, %LN and %EXT of edematous extremity had a significant correlation with TCD. The %EXT was correlated best with either TCD or %DTCD. The results suggest that the %EXT which corresponds to the degree of dermal backflow may be a simple and useful quantitative index for evaluating the severity and progression in lymphedema and predicting the effect of therapy

  15. Hydrogen Effect on the Circumferential Mechanical Properties of HANA-4 and HANA-6 Cladding Tubes

    International Nuclear Information System (INIS)

    KAERI has been doing a lot of out-of pile tests including an in-pile test to verify the performance of HANA cladding tubes for a high burn-up fuel rod, developed by them. When a zirconium alloy is used in a nuclear reactor, hydrides form in it from not only external hydrogen sources such as a waterside corrosion, dissolved hydrogen in a coolant, water radiolysis but also internal sources such as the hydrogen content in fuel pellets and the moisture absorbed by a uranium dioxide fuel pellet. Hydrides may act as a sudden failure at a very low strain. For low and medium hydrogen content, the hydrides crack during a tensile loading and accelerate the ductile fracture process. As a kind of simulation test to obtain the estimated data of HANA cladding tubes in a high burn-up state, the hydrogen effect on the axial tensile properties of a HANA-4(Zr-1.5Nb-0.0.4Sn- 0.21Fe-0.1Cu) cladding tube and that on the burst properties of HANA-4 and HANA-6 (Zr-1.1Nb-0.05Cu) cladding tubes was already studied. This study was also done to characterize the effect of hydrogen on the circumferential mechanical properties of HANA-4 and HANA-6 cladding tubes by a ring tension test at both room temperature and 350 .deg. C. Additional tests were also done on both Zircaloy-4 (Zr-1.26Sn-0.23Fe-0.12Cr) and A (Zr-1.0Nb-0.99Sn-0.11Fe) cladding tubes of a commercial grade to compare the hydrogen effect on their circumferential properties with that on the properties of the HANA-4 and HANA-6 cladding tubes

  16. Detailed analysis of the clinical effects of cell therapy for thoracolumbar spinal cord injury: an original study

    Directory of Open Access Journals (Sweden)

    Sharma A

    2013-07-01

    Full Text Available Alok Sharma,1 Nandini Gokulchandran,1 Hemangi Sane,2 Prerna Badhe,1 Pooja Kulkarni,2 Mamta Lohia,3 Anjana Nagrajan,3 Nancy Thomas3 1Department of Medical Services and Clinical Research, 2Department of Research and Development, 3Department of Neurorehabilitation, NeuroGen Brain and Spine Institute, Surana Sethia Hospital and Research Centre, Chembur, Mumbai, India Background: Cell therapy is amongst the most promising treatment strategies in spinal cord injury (SCI because it focuses on repair. There are many published animal studies and a few human trials showing remarkable results with various cell types. The level of SCI determines whether paraplegia or quadriplegia is present, and greatly influences recovery. The purpose of this study was to determine the significance of the clinical effects and long-term safety of intrathecal administration of autologous bone marrow-derived mononuclear cells, along with changes in functional independence and quality of life in patients with thoracolumbar SCI. Methods: We undertook a retrospective analysis of a clinical study in which a nonrandomized sample of 110 patients with thoracolumbar SCI underwent autologous bone marrow-derived mononuclear cell transplantation intrathecally and subsequent neurorehabilitation, with a mean follow-up of 2 years ± 1 month. Changes on any parameters were recorded at follow-up. The data were analyzed using the Wilcoxon's signed-rank test and McNemar's test. Functional Independence Measure and American Spinal Injury Association (ASIA scores were recorded, and a detailed neurological assessment was performed. Results: Overall improvement was seen in 91% of patients, including reduction in spasticity, partial sensory recovery, and improvement in trunk control, postural hypotension, bladder management, mobility, activities of daily living, and functional independence. A significant association of these symptomatic improvements with the cell therapy intervention was established

  17. Initial experience with circumferential pulmonary vein ablation guided by fusion of magnetic resonance imaging with three-dimensional electroanatomic mapping

    Institute of Scientific and Technical Information of China (English)

    TANG Kai; MA Jian; MA Fu-sheng; JlA Yu-he; ZHANG Shu

    2006-01-01

    @@ Catheter ablation for the treatment of atrial fibrillation (AF) has been a focal target of electrophysiological study in recent years. Up to date,circumferential pulmonary vein ablation (CPVA)guided by three-dimensional (3-D) electroanatomic mapping (Carto, USA) has been one of the most favourable procedures for the treatment of AF.

  18. The Influence of Hospital Volume on Circumferential Resection Margin Involvement: Results of the Dutch Surgical Colorectal Audit.

    Science.gov (United States)

    Gietelink, Lieke; Henneman, Daniel; van Leersum, Nicoline J; de Noo, Mirre; Manusama, Eric; Tanis, Pieter J; Tollenaar, Rob A E M; Wouters, Michel W J M

    2016-04-01

    This population-based study evaluates the association between hospital volume and CRM (circumferential resection margin) involvement, adjusted for other confounders, in rectal cancer surgery. A low hospital volume (CRM involvement (odds ratio = 1.54; 95% CI: 1.12-2.11). PMID:25790120

  19. Burn-out, Circumferential Film Flow Distribution and Pressure Drop for an Eccentric Annulus with Heated Rod

    DEFF Research Database (Denmark)

    Andersen, P. S.; Jensen, A.; Mannov, G.;

    1974-01-01

    Measurements of (1) burn-out, (2) circumferential film flow distribution, and (3) pressure drop in a 17 × 27.2 × 3500 mm concentric and eccentric annulus geometry are presented. The eccentric displacement was varied between 0 and 3 mm. The working fluid was water. Burn-out curves at 70 bar...... flow variation on burn-out is discussed....

  20. High speed OH-PLIF measurement of self-excited circumferential instabilities in an annular combustion chamber

    Science.gov (United States)

    Worth, Nicholas; Dawson, James

    2012-11-01

    Self-excited thermo-acoustic instabilities are a significant issue in the development of lean burn gas turbine combustors. Such instabilities arise through coupling of the unsteady heat release and acoustic waves, which can propagate both longitudinally and circumferentially in annular combustor geometries. Although a large number of studies have investigated longitudinal fluctuations in single axisymmetric flames, it is currently uncertain whether these results can be used to emulate circumferential oscillations in annular geometry. Therefore, the aim of the current project is to investigate the flame dynamics in an annular model gas turbine combustor during self-excited circumferential oscillations. Pressure measurements are used to characterise the circumferential oscillations, with high-speed OH chemiluminescence and OH-PLIF used to capture the flame dynamics. The flame structure and dynamics are significantly affected by both the proximity of neighbouring flames and the excitation mode; with different responses observed for small and large separation distances, and standing and spinning modes. These observations indicate that results from single flame investigations may only be representative of self-excited flames in annular geometry under in a limited set of conditions.

  1. Net-section limit moments and approximate J estimates for circumferential cracks at the interface between elbows and pipes

    International Nuclear Information System (INIS)

    This paper firstly presents net-section limit moments for circumferential through-wall and part-through surface cracks at the interface between elbows and attached straight pipes under in-plane bending. Closed-form solutions are proposed based on fitting results from small strain FE limit analyses using elastic-perfectly plastic materials. Net-section limit moments for circumferential cracks at the interface between elbows and attached straight pipes are found to be close to those for cracks in the centre of elbows, implying that the location of the circumferential crack within an elbow has a minimal effect on the net-section limit moment. Accordingly it is also found that the assumption that the crack locates in a straight pipe could significantly overestimate the net-section limit load (and thus maximum load-carrying capacity) of the cracked component. Based on the proposed net-section limit moment, a method to estimate elastic-plastic J based on the reference stress approach is proposed for circumferential cracks at the interface between elbows and attached straight pipes under in-plane bending.

  2. 胸腰椎骨折治疗的研究进展(综述)%Research progress of the treatment of thoracolumbar fracture

    Institute of Scientific and Technical Information of China (English)

    李圣

    2015-01-01

    胸腰椎骨折是指发生于胸11至腰1之间的脊柱骨折,由于其为胸腰椎移行区,为生物应力的集中点,所以易于发生损伤,而胸腰椎骨折的治疗目标是让患者存活,避免更进一步的神经损害,通过重建脊柱序列获得脊柱的稳定性并通过早期的活动及康复,从而使患者尽快恢复正常工作.胸腰椎骨折因其固有的解剖特点,在诊断、治疗等方面有其特殊性,且因其发生率较高,为临床工作经常遇到的疾病,为了更好的指导临床工作,现就胸腰椎骨折治疗的研究进展做一综述.%The thoracolumbar fracture are the spine fractures occurring at the T11 to the L1 level.Because it's the transition region of thoracolumbar spine and the focus of the biological stress,it is easy to damage.The goal of treatment of the thoracolumbar fracture is keeping patients alive,protecting from the further neural damage,obtaining the stability by constructing anatomical alignment of spinal columns and returning patients to workplace through early mobilization and rehabilitation.Because of its inherent anatomical features,the diagnosis and the treatment of thoracolumbar fracture are special,and there is a high morbidity of thoracolumbar fracture,which we are frequently encountering in the clinical work.To guide the clinical work better,we will take a review about the research progress of the treatment of thoracolumbar fracture.

  3. Circumferential fusion is dominant over posterolateral fusion in a long-term perspective: cost-utility evaluation of a randomized controlled trial in severe, chronic low back pain

    DEFF Research Database (Denmark)

    Soegaard, Rikke; Bünger, Cody E; Christiansen, Terkel;

    2007-01-01

    BACKGROUND DATA: The cost-effectiveness of circumferential fusion in a long-term perspective is uncertain but nonetheless highly relevant as the ISSLS prize winner 2006 in clinical studies reported the effect of circumferential fusion superior to the effect of posterolateral fusion. A recent trial found no...

  4. CLINICAL AND MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF THORACOLUMBAR INTERVERTEBRAL DISK EXTRUSIONS AND PROTRUSIONS IN LARGE BREED DOGS.

    Science.gov (United States)

    Gomes, Sergio A; Volk, Holger A; Packer, Rowena Ma; Kenny, Patrick J; Beltran, Elsa; De Decker, Steven

    2016-07-01

    Treatment recommendations differ for dogs with intervertebral disk extrusion vs. intervertebral disk protrusion. The aim of this retrospective, cross-sectional study was to determine whether clinical and magnetic resonance imaging (MRI) variables could be used to predict a diagnosis of thoracolumbar intervertebral disk extrusion or protrusion in dogs. Dogs were included if they were large breed dogs, had an MRI study of the thoracolumbar or lumbar vertebral column, had undergone spinal surgery, and had the type of intervertebral disk herniation (intervertebral disk extrusion or protrusion) clearly stated in surgical reports. A veterinary neurologist unaware of surgical findings reviewed MRI studies and recorded number, location, degree of degeneration and morphology of intervertebral disks, presence of nuclear clefts, disk space narrowing, extent, localization and lateralization of herniated disk material, degree of spinal cord compression, intraparenchymal intensity changes, spondylosis deformans, spinal cord swelling, spinal cord atrophy, vertebral endplate changes, and presence of extradural hemorrhage. Ninety-five dogs were included in the sample. Multivariable statistical models indicated that longer duration of clinical signs (P = 0.01), midline instead of lateralized disk herniation (P = 0.007), and partial instead of complete disk degeneration (P = 0.01) were associated with a diagnosis of intervertebral disk protrusion. The presence of a single intervertebral herniation (P = 0.023) and dispersed intervertebral disk material not confined to the disk space (P = 0.06) made a diagnosis of intervertebral disk extrusion more likely. Findings from this study identified one clinical and four MRI variables that could potentially facilitate differentiating intervertebral disk extrusions from protrusions in dogs. PMID:27038182

  5. Interrater reliability of identifying indicators of posterior ligamentous complex disruption when plain films are indeterminate in thoracolumbar injuries

    International Nuclear Information System (INIS)

    The Spine Trauma Study Group (STSG) has proposed a novel thoracolumbar injury classification system and score (TLICS) in an attempt to define traumatic spinal injuries and direct appropriate management schemes objectively. The TLICS assigns specific point values based on three variables to generate a final severity score that guides potential treatment options. Within this algorithm, significant emphasis has been placed on posterior ligamentous complex (PLC) integrity. The purpose of this study was to determine the interrater reliability of indicators surgeons use when assessing PLC disruption on imaging studies, including computed tomography (CT) and magnetic resonance imaging (MRI). Orthopedic surgeons and neurosurgeons retrospectively reviewed a series of thoracolumbar injury case studies. Thirteen case studies, including images, were distributed to STSG members for individual, independent evaluation of the following three criteria: diastasis of the facet joints on CT; posterior edema-like signal in the region of PLC components on sagittal T2-weighted fat saturation (FAT SAT) MRI; and disrupted PLC components on sagittal T1-weighted MRI. Interrater agreement on the presence or absence of each of the three criteria in each of the 13 cases was assessed. Absolute interrater percent agreement on diastasis of the facet joints on CT and posterior edema-like signal in the region of PLC components on sagittal T2-weighted FAT SAT MRI was similar (agreement 70.5%). Interrater agreement on disrupted PLC components on sagittal T1-weighted MRI was 48.9%. Facet joint diastasis on CT was the most reliable indicator of PLC disruption as assessed by both Cohen's kappa (κ=0.395) and intraclass correlation coefficient (ICC 0.430). The interrater reliability of assessing diastasis of the facet joints on CT had fair to moderate agreement. The reliability of assessing the posterior edema-like signal in the region of PLC components was lower but also fair, whereas the reliability of

  6. Refining the course of the thoracolumbar nerves: a new understanding of the innervation of the anterior abdominal wall.

    Science.gov (United States)

    Rozen, W M; Tran, T M N; Ashton, M W; Barrington, M J; Ivanusic, J J; Taylor, G I

    2008-05-01

    Previous descriptions of the thoracolumbar spinal nerves innervating the anterior abdominal wall have been inconsistent. With modern surgical and anesthetic techniques that involve or may damage these nerves, an improved understanding of the precise course and variability of this anatomy has become increasingly important. The course of the nerves of the anterior abdominal is described based on a thorough cadaveric study and review of the literature. Twenty human cadaveric hemi-abdominal walls were dissected to map the course of the nerves of the anterior abdominal wall. Dissection included a comprehensive tracing of nerves and their branches from their origins in five specimens. The branching pattern and course of all nerves identified were described. All thoracolumbar nerves that innervate the anterior abdominal wall were found to travel as multiple mixed segmental nerves, which branch and communicate widely within the transversus abdominis plane (TAP). This communication may occur at multiple locations, including large branch communications anterolaterally (intercostal plexus), and in plexuses that run with the deep circumflex iliac artery (DCIA) (TAP plexus) and the deep inferior epigastric artery (DIEA) (rectus sheath plexus). Rectus abdominis muscle is innervated by segments T6-L1, with a constant branch from L1. The umbilicus is always innervated by a branch of T10. As such, identification or damage to individual nerves in the TAP or within rectus sheath is unlikely to involve single segmental nerves. An understanding of this anatomy may contribute to explaining clinical outcomes and preventing complications, following TAP blocks for anesthesia and DIEA perforator flaps for breast reconstruction. PMID:18428988

  7. Finite Element Limit Pressures for Circumferential Through-Wall Cracks in the Interface between Elbow and Pipe

    International Nuclear Information System (INIS)

    Among integrity assessment method based on a fracture mechanics concept for piping system, a limit load method is one of the important way to predict a maximum load carrying capacity in the materials with high ductility in the sense that it is used to either assess directly structural integrity of pipe based on fully plastic fracture mechanics or calculate elasticplastic fracture mechanics parameters based on reference stress concept. In nuclear power plants, piping system often involves elbows welded to straight pipe. Since welded regions are vulnerable to cracking, it is important to predict an accurate limit load for pipes with a crack in the interface between elbows and attached pipes. However, although extensive works have been made for developing limit analysis methods for cracked pipes, they were mainly for straight pipes. Recently, limit moment solutions for elbow that is attached to straight pipe with a circumferential through-wall crack(TWC) in the interface were proposed, whereas limit pressure for this geometry is not suggested yet. In this context, plastic limit pressures of circumferential TWCs between elbow and straight pipe were calculated in the present study considering geometric parameters such as an elbow curvature, a pipe size and a crack length. In the present study, the FE plastic limit analyses for circumferential TWC in the interface between elbow and pipe under internal pressure were conducted based on elastic perfectly plastic assumption. Based on the present FE results, it is found that plastic limit pressures of straight pipes with circumferential TWC are not appropriate for predicting plastic limit pressures of circumferential TWC in the interface between elbow and pipe for shorter crack length

  8. Finite Element Limit Pressures for Circumferential Through-Wall Cracks in the Interface between Elbow and Pipe

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Yoon-Young; Han, Tae-Song; Huh, Nam-Su [Seoul National Univ., Seoul (Korea, Republic of); Jeong, Jae-Uk [Sungkyunkwan Univ., Suwon (Korea, Republic of)

    2014-10-15

    Among integrity assessment method based on a fracture mechanics concept for piping system, a limit load method is one of the important way to predict a maximum load carrying capacity in the materials with high ductility in the sense that it is used to either assess directly structural integrity of pipe based on fully plastic fracture mechanics or calculate elasticplastic fracture mechanics parameters based on reference stress concept. In nuclear power plants, piping system often involves elbows welded to straight pipe. Since welded regions are vulnerable to cracking, it is important to predict an accurate limit load for pipes with a crack in the interface between elbows and attached pipes. However, although extensive works have been made for developing limit analysis methods for cracked pipes, they were mainly for straight pipes. Recently, limit moment solutions for elbow that is attached to straight pipe with a circumferential through-wall crack(TWC) in the interface were proposed, whereas limit pressure for this geometry is not suggested yet. In this context, plastic limit pressures of circumferential TWCs between elbow and straight pipe were calculated in the present study considering geometric parameters such as an elbow curvature, a pipe size and a crack length. In the present study, the FE plastic limit analyses for circumferential TWC in the interface between elbow and pipe under internal pressure were conducted based on elastic perfectly plastic assumption. Based on the present FE results, it is found that plastic limit pressures of straight pipes with circumferential TWC are not appropriate for predicting plastic limit pressures of circumferential TWC in the interface between elbow and pipe for shorter crack length.

  9. A numerical investigation of constraint effects in circumferentially cracked pipes and fracture specimens including ductile tearing

    International Nuclear Information System (INIS)

    This work addresses a two-parameter description of crack-tip fields in bend and tensile fracture specimens incorporating the evolution of near-tip stresses following stable crack growth with increased values of the crack driving force as characterized by J. The primary objective of this study is twofold. First, the present investigation broadens current understanding on the role of constraint and test conditions in defect assessment procedures for pipeline girth welds using SE(T) and SE(B) specimens. Second, the work addresses the potential coupled effects of geometry and ductile tearing on crack-tip constraint as characterized by the J−Q theory which enables more accurate correlations of crack growth resistance behavior in conventional fracture specimens. Plane-strain and 3-D finite element computations including stationary and growth analyses are conducted for 3P SE(B) and clamped SE(T) specimens having different notch depth (a) to specimen width (W) ratio in the range 0.1 ≤ a/W ≤ 0.5. Additional 3-D finite element analyses are also performed for circumferentially cracked pipes with a surface flaw having different crack depth (a) over pipe wall thickness (t) ratios and fixed crack length. A computational cell methodology to model Mode I crack extension in ductile materials is utilized to describe the evolution of J with the accompanying evolving near-tip opening stresses. Laboratory testing of an API 5L X70 steel at room temperature using standard, deeply cracked C(T) specimens is used to measure the crack growth resistance curve for the material and to calibrate the key cell parameter defined by the initial void fraction, f0. A key result emerging from this study is that shallow crack SE(B) specimens can accurately and conservately produce crack growth resistance curves that describe well the measuring toughness capacity of circumferentially cracked pipes under remote bending. The present results provide additional understanding of the effects of

  10. Influence of circumferential flaw length on internal burst pressure of a wall-thinned pipe

    International Nuclear Information System (INIS)

    Highlights: ► The effect of θ on pf was examined by experimental analysis and FEA. ► Here θ is the circumferential angle of a flaw, pf is the internal burst pressure. ► pf decreased as θ increased in some cases. ► The effect of θ on pf should be taken into consideration in evaluating pf. -- Abstract: This paper examines the effect of the circumferential angle of a flaw θ on the internal burst pressure pf of pipes with artificial wall-thinned flaws. The effect of θ has conventionally been regarded as unimportant in the evaluation of the pf of wall-thinned straight pipes. Therefore, a burst pressure equation for an axial crack inside a cylinder (Fig. 1, left), such as Kiefner's equation (Kiefner et al., 1973), has been widely applied (ANSI/ASME B31.G., 1991; Hasegawa et al., 2011). However, the following implicit assumptions notably exist when applying the equation to planar flaws in situations with non-planar flaws. 1)The fracture mode of the non-planar flaw under consideration is identical to that of the crack. 2)The effect of θ on pf, which is not considered for an axial crack, is small or negligible. However, the experimental results from the systematic burst tests for carbon steel pipes with artificial wall-thinned flaws examined in this paper showed that these implicit assumptions may be incorrect. In this paper the experimental results are evaluated in further detail. The purpose of the evaluation was to clarify the effect of θ on pf. Specifically, the significance of the flaw configuration (axial length δz and wall-thinning ratio t1/t) was studied for its effects on θ and pf. In addition, a simulation of this effect was conducted using a large strain elastic-plastic Finite Element Analysis (FEA) model. As observed from the experimental results, θ tended to affect pf in cases with large δz, and t1/t was also correlated with a decrease in pf with an increase in θ. These tendencies were successfully simulated by the large strain elastic

  11. Development of a J-estimation scheme for internal circumferential and axial surface cracks in elbows

    International Nuclear Information System (INIS)

    This report summarizes efforts to develop elastic and elastic-plastic fracture mechanics analyses for internal surface cracks in elbows. The analyses involved development of a GE/EPRI type J-estimation scheme which requires an elastic and fully plastic contribution to crack-driving force in terms of the J-integral parameter. The elastic analyses require the development of F-function values to relate the Je term to applied loads. Similarly, the fully plastic analyses require the development of h-functions to relate the Jp term to the applied loads. The F- and h-functions were determined from a matrix of finite element analyses. To minimize the cost of the analyses, three-dimensional ABAQUS finite element analyses were compared to a simpler finite element technique called the line-spring method. The line-spring method provides a significant computational savings over the full three-dimensional analysis. The comparison showed excellent agreement between the line-spring and three-dimensional analysis. This experience was consistent with comparisons with circumferential surface-crack analyses in straight pipes during the NRC's Short Cracks in Piping and Piping Welds program

  12. Prediction of pressure tube ballooning under non-uniform circumferential temperature gradients and high internal pressure

    International Nuclear Information System (INIS)

    In some accident scenarios in CANDU reactors the pressure tube is expected to reach sufficiently high temperature at high internal pressure such that the pressure tube expands radially, i.e., the pressure tube balloons.Under these conditions it is of importance to the assessment of fuel channel integrity to be able to accurately predict the timing and extent of pressure tube ballooning. If the circumferential temperature gradient on the pressure tube is non-uniform, the resulting transverse hoop stress is non-uniform and the pressure tube experiences a non-uniform ballooning. This could result in a failure of the pressure tube before it balloons into contact with the surrounding calandria tube. The fuel channel integrity code SMARTT (Simulation Method for Azimuthal and Radial Temperature Transients) is used to predict the ballooning of CANDU Zr-2.5wt%Nb pressure tubes. The pressure tube strain rate calculation in SMARTT was extracted and used as the basis for the code PTSTRAIN which was constructed to model pressure tube ballooning with the temperature of the pressure tube and the internal pressure specified as the boundary conditions for the calculation. The main objectives of this paper are to describe the comparison of the predictions of this code against two different sets of experiments which were performed with defected and non-defected pressure tubes, and to provide further validation of the pressure tube ballooning model against independent experiments. (author)

  13. Fracture behavior evaluations for ferritic steel piping with circumferential double flaws on the inner surface

    International Nuclear Information System (INIS)

    Methods for assessing the structural integrity of nuclear components having some flaws are provided in the Rules on Fitness-for-Service for Nuclear Power Plants of the JSME code (JSME FFS code). Although the JSME FFS code provides such methods for piping with a single flaw, it does not describe any method for fracture assessment of piping with multiple flaws including flaw coalescence criteria. Some investigations on the fracture behavior of mainly austenitic stainless steel piping with multiple flaws, whose fracture mode is plastic collapse, have recently been reported and fracture assessment methods have been proposed. In the present study, fracture tests and analyses of carbon steel piping with a single and two circumferential flaw(s) on the inner surface were conducted to investigate a method for fracture assessment of ferritic steel piping with multiple flaws. It was found that fracture assessment based on the twice elastic slope method and the plastic collapse mechanism gave inadequate results for a large single flaw. Including this case, two kinds of elastic–plastic fracture assessment method, one using the Z-factor in the JSME FFS code and the other by ductile instability analysis, gave conservative estimates of fracture strength even when the structural factor SF was not considered (i.e. SF = 1)

  14. The Prognostic Value of Circumferential Resection Margin Involvement in Patients with Extraperitoneal Rectal Cancer.

    Science.gov (United States)

    Shin, Dong Woo; Shin, Jin Yong; Oh, Sung Jin; Park, Jong Kwon; Yu, Hyeon; Ahn, Min Sung; Bae, Ki Beom; Hong, Kwan Hee; Ji, Yong Il

    2016-04-01

    The prognostic influence of circumferential resection margin (CRM) status in extraperitoneal rectal cancer probably differs from that of intraperitoneal rectal cancer because of its different anatomical and biological behaviors. However, previous reports have not provided the data focused on extraperitoneal rectal cancer. Therefore, the aim of this study was to examine the prognostic significance of the CRM status in patients with extraperitoneal rectal cancer. From January 2005 to December 2008, 248 patients were treated for extraperitoneal rectal cancer and enrolled in a prospectively collected database. Extraperitoneal rectal cancer was defined based on tumors located below the anterior peritoneal reflection, as determined intraoperatively by a surgeon. Cox model was used for multivariate analysis to examine risk factors of recurrence and mortality in the 248 patients, and multivariate logistic regression analysis was performed to identify predictors of recurrence and mortality in 135 patients with T3 rectal cancer. CRM involvement for extraperitoneal rectal cancer was present in 29 (11.7%) of the 248 patients, and was the identified predictor of local recurrence, overall recurrence, and death by multivariate Cox analysis. In the 135 patients with T3 cancer, CRM involvement was found to be associated with higher probability of local recurrence and mortality. In extraperitoneal rectal cancer, CRM involvement is an independent risk factor of recurrence and survival. Based on the results of the present study, it seems that CRM involvement in extraperitoneal rectal cancer is considered an indicator for (neo)adjuvant therapy rather than conventional TN status. PMID:27097629

  15. Tensile and Fracture Properties of Circumferentially Notched Tensile Specimens of Stainless Steel Weldments

    International Nuclear Information System (INIS)

    The tensile and fracture properties of different types of austenitic stainless steel weldments were determined using round notched tensile specimens. These included 304L, 316L and 6%Mo super austenitic stainless steels and their weld metals. The triaxial state of stress, the plastic constraint and the plane strain conditions developed ahead of the notch root make notched specimens eligible for the evaluation of fracture toughness. This was achieved through the testing procedure: J-evaluation on tensile test (JETT) using circumferentially notched round bar specimens. The JETT index was taken as a measure of the relevant elastic-plastic fracture toughness of the tested materials. In the case of austenitic stainless steels being too ductile at room temperature the resulted JETT were of relatively higher values than the fracture toughness values determined from the standard fracture mechanics test methods. This could be related to the difference in the stress state ahead of the sharp crack of the standard fracture mechanics specimen and that of the blunt notch of the tensile specimen. The results showed that the 6% Mo weld metal ranked highest while the 316L weld metal ranked lowest regarding JETT fracture toughness values. The deformation mechanisms pertinent to austenitic stainless steels (generation of stacking faults and formation of strain induced martensite) were employed for the interpretation of the experimental results.

  16. Simplified method of calculating residual stress in circumferential welding of piping

    International Nuclear Information System (INIS)

    Many circumferential joints of piping are used in as-welded state, but in these welded joints, the residual stress as high as the yield stress of materials arises, and causes to accelerate stress corrosion cracking and corrosion fatigue. The experiment or the finite element method to clarify welding residual stress requires much time and labor, and is expensive, therefore, the author proposed the simplified method of calculation. The heating and cooling process of welding is very complex, and cannot be modeled as it is, therefore, it was assumed that in multiple layer welding, the welding condition of the last layer determines the residual stress, that material constants are invariable regardless of temperature, that the temperature distribution and residual stress are axisymmetric, and that there is repeated stress-strain relation in the vicinity of welded parts. The temperature distribution at the time of welding, thermal stress and welding residual stress are analyzed, and the material constants used for the calculation of residual stress are given. As the example of calculation, the effect of welding heat input and materials is shown. The extension of the method to a thick-walled pipe is discussed. (Kako, I.)

  17. Myocardial perfusion changes following 1 year of exercise training assessed by thallium-201 circumferential count profiles

    International Nuclear Information System (INIS)

    The effect of exercise training on myocardial perfusion was assessed using initial and 1-year thallium-201 (Tl-201) exercise studies in 56 patients with stable coronary artery disease (CAD). Subjects had been randomized into a trained group participating in supervised exercise three times per week and a control group. Indices (non-dimensional units) based on computer-analyzed circumferential count profile from nine regions of the heart, assessed in three projections, were used to eliminate observer bias and more accurately quantitate Tl-201 distribution and 4-hour washout. There was serial improvement of the global distribution count profiles in 21 of 27 (77.8%) of the trained and in 9 of 29 (31.0%) of the control subjects (p less than 0.001). The mean interval change in global initial distribution over the year period was 5 +/- 13 (mean +/- SD) in the trained and -6 +/- 14 in the control groups (p less than 0.003). The mean initial distribution of the trained group had improvement in all nine regions (significant in three), while the control group showed mean improvement in only one of nine regions. Additionally, the trained group showed improvement in the mean washout in five of nine regions (significant in three), while no mean regional washout improvement occurred in the control group. Thus, in this group of patients with stable CAD, exercise training resulted in apparently improved cardiac perfusion evidenced by enhance Tl-201 uptake and washout

  18. The stability of through-wall circumferential cracks in cylindrical pipes subjected to bending loads

    International Nuclear Information System (INIS)

    Tada, Paris and Gamble have used the tearing modulus approach to show that when a circumferential through-wall crack exists in a 304 SS circular cylindrical pipe, and the pipe is subjected to an applied bending moment, then crack growth requires the rotation at the pipe-ends to be increased, (i.e. crack growth is stable), unless the pipe length is unduly large. On this basis it was concluded that unstable fracture is unlikely to occur in BWR SS piping, when the system is designed in accord with the ASME Code load levels for normal operation and anticipated transients. The Tada-Paris-Gamble analysis focuses on the inter-relation between instability and the onset of crack extension, and does not specifically consider the possibility that a crack might become unstable after some stable crack extension. The paper addresses this aspect of the crack stability problem using a crack tip opening angle criterion for crack extension, which has similarities with the tearing modulus approach. The results show that unstable fracture should not occur even after some stable crack extension, again provided that the pipe length is not unduly large. In other words, guillotine failure of a pipe in a BWR system is unlikely, even though the ASME Code limiting stress levels as might be exceeded, as may be the case with a very severe earthquake. (orig./HP)

  19. J-integral study of elbow with circumferential through-wall crack

    International Nuclear Information System (INIS)

    The elbow is an important component in nuclear piping system, and also is the location where crack easily occurrs. To ensure the structural integrity of the nuclear piping system, a fracture mechanics analysis for the cracked elbows will be necessarily performed. In this paper, the 3-D elastic-plastic fracture mechanics methodology is used to study the elbows with a through-wall circumferential crack by using of ABAQUS software, and some numerical results for J-integral are obtained. the calculated results show that the influence of bending radius on J-integral is not associated with locations of the cracks. It is, however, intimate to sizes of the cracks. The effects on the J-integral for elbows with small size of cracks are insignificant. As to the J-integral for elbows with large size of cracks, the value of the J-integral is reduced as the Rb/R ratio of bending radii increases. In the case that the end rotating angle is kept unchanged, the relation between R/t ratio and J-integral is approximately linear, i.e., a linear interpolation can be used. (authors)

  20. Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats.

    Science.gov (United States)

    Takano, Hiroshi; Isogai, Tomomi; Aoki, Takuma; Wakao, Yoshito; Fujii, Yoko

    2015-02-01

    The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM were performed. Segmental assessments of left ventricle (LV) wall for strain and strain rate variables in cats with HCM were also performed. As a result, technically adequate images were obtained in 97.6% of the segments for STE analysis. Sedation using buprenorphine and acepromazine did not affect any global strain nor strain rate variable. In LV segments of cats with HCM, reduced segmental radial strain and strain rate variables had significantly related with segmental LV hypertrophy. It is concluded that STE analysis using short axis images of LV appeared to be clinically feasible in cats, having the possibility to be useful for detecting myocardial dysfunctions in cats with diseased heart. PMID:25373881

  1. Leak before break behaviour of austenitic and ferritic pipes containing circumferential defects

    Energy Technology Data Exchange (ETDEWEB)

    Stadtmueller, W.; Sturm, D.

    1997-04-01

    Several research projects carried out at MPA Stuttgart to investigate the Leak-before-Break (LBB) behavior of safety relevant pressure bearing components are summarized. Results presented relate to pipes containing circumferential defects subjected to internal pressure and external bending loading. An overview of the experimentally determined results for ferritic components is presented. For components containing postulated or actual defects, the dependence of the critical loading limit on the defect size is shown in the form of LBB curves. These are determined experimentally and/or by calculation for through-wall slits, and represent the boundary curve between leakage and massive fracture. For surface defects and a given bending moment and internal pressure, no fracture will occur if the length at leakage remains smaller than the critical defect length given by the LBB curve for through-wall defects. The predictive capability of engineering calculational methods are presented by way of example. The investigation programs currently underway, testing techniques, and initial results are outlined.

  2. Residual Stresses Due to Circumferential Girth Welding of Austenitic Stainless Steel Pipes

    Science.gov (United States)

    Tarak, Farzan

    Welding, as a joining method in fabrication of engineering products and structural elements, has a direct influence on thermo-mechanical behavior of components in numerous structural applications. Since these thermo-mechanical behaviors have a major role in the life of welding components, predicting thermo-mechanical effects of welding is a major factor in designing of welding components. One of the major of these effects is generation of residual stresses due to welding. These residual stresses are not the causes of failure in the components solely, but they will add to external loads and stresses in operating time. Since, experimental methods are time consuming and expensive, computational simulation of welding process is an effective method to calculate these residual stresses. This investigation focuses on the evaluation of residual stresses and distortions due to circumferential girth welding of austenitic stainless steel pipes using the commercial finite element software ESI Visual-Environment and SYSWELDRTM to simulate welding process. Of particular importance is the comparison of results from three different types of mechanics models: 1) Axisymmetric, 2) Shell, and 3) Full 3-D.

  3. Interactions of a propeller with a stator-induced circumferentially varying flow

    Energy Technology Data Exchange (ETDEWEB)

    Farnsworth, John [Rensselaer Polytechnic Institute, Mechanical Aerospace and Nuclear Engineering, Troy, NY (United States); US Air Force Academy, Department of Aeronautics, Colorado Springs, CO (United States); Amitay, Michael [Rensselaer Polytechnic Institute, Mechanical Aerospace and Nuclear Engineering, Troy, NY (United States); Rensselaer Polytechnic Institute, Center for Flow Physics and Control (CeFPaC), Troy, NY (United States); Beal, David; Huyer, Stephen A. [Naval Undersea Warfare Center, Division, Vehicle Dynamics and Signature Control, Newport, RI (United States)

    2012-02-15

    The interactions of a circumferentially varying stator cascade and a downstream fixed pitch propeller were investigated experimentally. The global performance of the components and the coupled system were systematically investigated through force and moment measurements on the propulsor model in a water tunnel. In addition, the wake of the cyclic stator cascade with and without the propeller was investigated downstream from a propulsor model using the Stereoscopic PIV technique. A cyclic distribution of the stators' deflections resulted in non-axisymmetric distributions of the flow field downstream of the stator array. The stator distribution alone produced a significant side force that increased linearly with stator pitch amplitude. When a propeller was incorporated downstream from the cyclic cascade, the side force from the stator cascade was reduced, but a small normal force and pitching moment were created. The generation of these secondary forces and moments can be related to the redistribution of the tangential flow from the cyclic cascade into the axial direction by the retreating and advancing blade states of the fixed pitch propeller. (orig.)

  4. Simultaneously Combined Anterior-Posterior Approaches for Subaxial Cervical Circumferential Reconstruction in a Sitting Position.

    Science.gov (United States)

    Han, Yue; Xia, Qun; Hu, Yong-cheng; Zhang, Ji-dong; Lan, Jie; Ma, Xin-long

    2015-11-01

    The purpose of this article is to introduce and analyze the feasibility of simultaneously combined anterior-posterior approaches for subaxial cervical circumferential reconstruction in sitting position. A retrospective case review was performed for above surgery procedure. A 79-year-old man was confirmed subaxial cervical fracture and dislocation with facet locked by radiological examination, and the involved levels were C5-6. According to American Spinal Injury Association (ASIA) classification, the impairment scale was grade B. And the Subaxial Cervical Spine Injury and Severity Score (SLIC) were 9. The patient was restricted in sitting position with traction on a halo in extension to immobilize the head during the operation. A posterior laminectomy and pedicle screws insertion to the involved cervical spine was performed firstly. And then the anterior discectomy and strut graft were accomplished through an anterior cervical approach. The final fixation was finished by clamping the strut graft with pedicle screw system. Total blood loss was 600 ml and the total operating time was 150 min. The patient was followed up for 6 months. The symptom of neck pain improved distinctly and no evidence about implant failure was noted. Neurological status improvement was confirmed and the ASIA scale was improved to grade C. We believed that the simultaneously combined anterior-posterior approach in sitting position was safe and more advantageous for appropriate cases. PMID:26790982

  5. Stress-intensity-factor influence coefficients for axial and circumferential flaws in reactor pressure vessels

    International Nuclear Information System (INIS)

    Weight-function techniques in linear elastic fracture mechanics utilize stress-intensity-factor influence coefficients K* and superposition principles to compute stress intensity factors. This paper presents influence coefficients for two flaw geometries often employed in fracture analyses of reactor pressure vessels: (1) infinitely long, axial, inside-surface flaws and (2) 360 degrees, circumferential, inside-surface flaws. Calculations were performed using ABAQUS, a nuclear quality assurance (NQA-1) certified finite-element program which employs a highly accurate crack extension technique for the computation of theJ-integral. Influence coefficients are computed for flaw depths in the range 0.01 ≤ a/T ≤ 0.9 with particular emphasis on shallow flaws (a/T ≤ 0. 1). This study addresses vessels having R/T = 10 which is appropriate for most PWRs in USA. The influence coefficients have been implemented in the FAVOR fracture-mechanics code currently being developed under the NRC-funded HSST Program at ORNL

  6. Corrective actions

    International Nuclear Information System (INIS)

    The variety of corrective actions which have been attempted at many radioactive waste disposal sites points to less than ideal performance by present-day standards at many closed and presently-operating sites. In humid regions, most of the problems have encompassed some kind of water intrusion into the buried waste. In arid regions, the problems have centered on trench subsidence and intrusion by plant roots and animals. It is overwhelmingly apparent that any protective barrier for the buried waste, whether for water or biological intrusion, will depend on stable support from the underlying burial trenches. Trench subsidence must be halted, prevented, or circumscribed in some manner to assure this necessary long-term support. Final corrective actions will differ considerably from site to site, depending on unique geological, pedological, and meteorological environments. In the meantime, many of the shorter-term corrective actions described in this chapter can be implemented as immediate needs dictate

  7. Surgical treatment of post-traumatic kyphosis in the thoracolumbar spine: indications and technical aspects

    OpenAIRE

    Munting, Everard

    2009-01-01

    Indications for correction of post-traumatic kyphotic deformity of the spine and technical aspects of the surgical procedure are reviewed. Surgical correction of post-traumatic deformity of the spine should be considered in patients presenting a local excess of kyphosis in the fractured area superior to 20° with poor functional tolerance. Severe pain, explained by objective factors such as canal or neuroforamen compromise with or without peripheral symptoms, angular deformity, non-union, foca...

  8. Mismatch Limit Load Analyses for V-groove Welded Pipe with Through-wall Circumferential Defect in Centre of Weld

    International Nuclear Information System (INIS)

    The present work reports the mismatch limit loads for a V-groove welded pipe for a circumferential crack using finite element (FE) analyses. To integrate the effect of groove angles on mismatch limit loads, one geometry related slenderness parameter was modified by relevant geometric parameters including the groove angle, crack depth, and root opening based on plastic deformation patterns in the theory of plasticity. Circumferential through-wall cracks are located at the centre of the weldments with two different groove angles (45 .deg., 90 .deg.). With regard to the loading conditions, axial (longitudinal) tension and bending are applied for all cases. For the parent and weld metal, elastic-perfectly plastic materials are considered to simulate and analyze under- and over-matching conditions in plasticity. The overall results from the proposed solutions are found to be similar to the FE results

  9. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    OpenAIRE

    Iannicelli, Elsa; Di Renzo, Sara; ferri, mario; Pilozzi, Emanuela; Di Girolamo, Marco; Sapori, Alessandra; Ziparo, Vincenzo; David, Vincenzo

    2014-01-01

    Objective To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Materials and Methods Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy...

  10. Different bone regeneration patterns in periimplant circumferential gap defects grafted with two types of osteoconductive biomaterial.

    Science.gov (United States)

    Lee, Jung-Seok; Sohn, Joo-Yeon; Lim, Hyun-Chang; Jung, Ui-Won; Choi, Seong-Ho

    2016-08-01

    This study aimed to determine healing patterns in periimplant gap defect grafted with demineralized bovine bone mineral (DBBM) and porous titanium granules (PTG), which are known to induce a minimal tissue reaction and to undergo minimal biodegradation in healing process. Experiments were performed using a standardized periimplant gap-defect model in dogs with two observational periods: 4 and 8 weeks. Circumferential defects were surgically induced around dental implants on unilateral mandibles in five dogs, and collagen barrier membranes were placed over the DBBM and PTG grafts at two experimental sites and over a nongrafted site. Four weeks later, the same procedures were performed on the contralateral mandible, and the animals allowed to heal for a further 4 weeks, after which they were sacrificed and their mandibles with graft/control sites harvested for histologic evaluation. Both types of grafted biomaterials significantly enhanced the defect fill with newly formed bone, but the bone-to-implant contact (BIC) was significantly increased only at sites that had been grafted with DBBM. The two experimental sites exhibited different healing patterns, with new bone formation being observed on the surface of the DBBM particles throughout the defect, while there was no de novo bone formation on the PTG surface, but rather appositional bone growth from the base and lateral walls of the defect. It has been suggested that gap-defect filling with DBBM around dental implants may enhance both BIC and defect fill; however, the present findings show that defect grafting with PTG enhances only defect fill and not BIC. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1202-1209, 2016. PMID:26087247

  11. Early-phase changes of P-wave characteristics after circumferential pulmonary vein isolation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Liang; JIANG Wei-feng; ZHOU Li; LIU Xu

    2013-01-01

    Background Circumferential pulmonary vein isolation (CPVI),as the basal ablation strategy for treating atrial fibrillation (AF),not only isolates the connection between the left atrium (LA) and the pulmonary veins (PVs),but also induces extensive atrial endocardia damage.This could have an effect on the sinus pulse conduction in the LA and subsequently result in changes of P-wave characteristics of surface electrocardiogram (ECG).Methods Fifty consecutive patients underwent CPVI for symptomatic drug-refractory paroxysmal AF.The 12-lead ECGs were recorded one day before CPVI and seven days after CPVI at sinus rhythm by a standard resting ECG device.Measured characteristics of the P-wave consisted of P-wave duration (PWD),P-wave amplitude (PWA),P-wave polarity (PWP),P-wave notch,P-wave dispersion and P-wave index.Results After CPVI,a prevalent decrease of PWD,PWA,and P-wave dispersion was observed; a transition of P-wave polarity was observed in the leads of Ⅲ,aVL and aVF.The rate of P-wave notch decreased significantly in all leads,especially in the leads of Ⅱ,Ⅲ,aVF and V3.Patients with sinus rhythm had a shorter P-wave dispersion and P-wave index and had a lower rate of P-wave notch compared with the patients with recurrent atrial tachyarrhythmia.Conclusion Observations from using the surface ECG showed that CPVI has instant effects on the electrical conduction in the LA,and several changes of P-wave characteristics associated with development of AF are improved by CPVI.

  12. Efficacy of posterior vertebral column resection for the treatment of chronic thoracolumbar tuberculosis with secondary paraplegia%后路脊柱切除重建术治疗胸腰椎陈旧性结核继发截瘫

    Institute of Scientific and Technical Information of China (English)

    李锐; 施永彦; 张功礼; 李锋

    2012-01-01

    Objective To observe the therapeutical effect of posterior vertebral column resection on chronic thoracolumbar tuberculosis with secondary paraplegia and to provide a safe and effective method for the treatment of chronic thoracolumbar tuberculosis with secondary paraplegia.Methods From Aug.2007 to Mar.2010,12 cases with chronic thoracolumbar tuberculosis and secondary paraplegia were surgically treated by posterior vertebral column resection and Titanium net support for bone graft and internal fixation operation treatment.Cobb angle was measured,and conditions of internal fixation were observed before and after the operation by X-ray films.Neurological status were evaluated by Frankel grades.Results The follow-up periods was 6- 18 months( on average 11 months).Operations eased all patients' back and chest pain.Frankel grade increased from C preoperatively to grade D or E postoperatively in 6 cases,from grade D to E in 4 cases and from grade B to C in 1 case.No obvious improvement of Frankel grade was observed in the other patient of grade B.The average Cobb angles were(76.0 ± 23.4) ° before surgery,( 15.5 ± 6.3 ) ° at one week after surgery and ( 16.0 ± 8.2) °at the last follow-up.The difference in the Cobb angle before and at one week after treatment was significant( t =3.41,P < 0.01 ).No difference was found in the Cobb angle between at one week after treatment and at the last follow-up (t =1.58,P > 0.05 ).All patients got bony fusion with Titanium net.No complications occurred with internal fixation.Conclusion Posterior vertebral column resection is a feasible method for the treatment of chronic thoracolumbar tuberculosis with secondary paraplegia.It achieves neurological decompression with high correction rate and minor injury,and no anterior surgery is needed.%目的 观察后路脊柱切除重建术治疗胸腰椎陈旧性结核继发截瘫的临床效果,为胸腰椎陈旧性脊柱结核继发截瘫手术治疗提供一种安

  13. Clinical observation of posterior decompression,interbody bone grafting and internal fixation for treatment of thoracolumbar burst fracture in one stage%一期后路椎管减压、椎间植骨内固定术治疗胸、腰椎爆裂性骨折的临床观察

    Institute of Scientific and Technical Information of China (English)

    张莹; 初同伟; 张超; 潘勇; 张正丰; 周跃

    2012-01-01

    Objective To investigate the management and clinical effect of subtotal corpectomy and three-column stabilization through posterior approach for thoracolumbar burst fractures. Methods Sixteen cases(9 males,7 females) with the thoracolumbar burst fractures in the hospital from Jan 2009 to Feb 2007 , were treated with posterior subtotal resection of vertebral body, implantation of titanium cage reconstruction,and pedicle screw internal fixation. The group age was from 23 to 55 years old. The site of the fracture were T12 in 7 cases, L1 in 4 cases,and L2 in 4 cases. According to Denis classification,all cases were burst fracture, including: ∧ type 4 cases,B type 8 cases,D type 3 cases,and K type 1 case. Six patients had neurologically complete paralysis,nine incomplete, and one intact. Pre and post operative neurological status,the correction and loss of Cobbs angle were evaluated. Results ∧11 patients during and after surgery were without severe complications,and postoperative clinical symptoms improved significantly. 13 patients were observed for more than 1 years. Three patients were lost in observed. Last follow-up vertebral Cobb angle was 8°- 16°(mean 8. 6°). Four patients Frankel A Grade of neurological function were with no significant recovery,and the rest had varying degrees of neurological recovery. Conclusion The subtotal corpectomy and three-column stabilization through posterior approach for thoracolumbar burst fractures,surgery time is short,and three-column injury in the treatment of thoracolumbar fractures is with satisfactory clinical results.%目的 探讨后路经椎根、椎管减压,椎间植骨内固定术治疗胸、腰椎爆裂性骨折中的临床疗效.方法 收集该科2009年1月至2010年2月应用经后路椎体次全切、钛网植骨重建、椎弓根螺钉内固定技术治疗胸、腰椎爆裂性骨折患者16例,其中,男9例,女7例;年龄23~55岁.T12骨折5例,L1骨折7例,L2骨折4例.Denis 分型

  14. Thoracolumbar Tuberculosis: Implications for Appropriate Management based on Disease Location and Proposal of a Novel Scoring System

    Directory of Open Access Journals (Sweden)

    Shahryar Noordin

    2011-01-01

    Full Text Available Objective: To identify factors indicating disease severity in patients with thoracolumbar tuberculosis requiring surgical intervention.Design: Medical charts of patients who underwent surgery for thoracic and lumbar spinal tuberculosis from 1990-2005 were reviewed. Patients with different levels of disease were compared in terms of neurological deficits, duration of symptoms, previous antituberculous therapy, nutritional status and associated co-morbids.Results: Ninety-three patients aged 7-77 years (mean age 40 years were included. Thoracic spine was involved in 80% of operated patients, and lumbar spine in 20%. Severe neurological impairment (Frankel A to C was present in 68% of patients with thoracic disease, as compared to 5% with lumbar disease (p<0.05. Postoperatively, complete neurological recovery occurred in 65% with thoracic versus 100% with lumbar disease (p<0.05. Based on the disease location and pertinent elements in clinical history, physical signs, radiographic and biochemical features, a scoring system was developed.Conclusion: In endemic areas with limited resources, strategies for cost-effective care are needed. By objectively outlining the treatment approach, the judicious use of surgery offers hope for enormous cost savings in countries endemic for tuberculosis, averting complications from disease progression

  15. 椎体成形术治疗胸腰椎骨折的临床效果观察%Clinical Effect of Vertebroplasty Treatment of Thoracolumbar Fractures

    Institute of Scientific and Technical Information of China (English)

    方德归

    2012-01-01

      Objective Explored the clinical effect of vertebroplasty treatment of thoracolumbar fractures. Methods Selected our hospital 88 patients with thoracolumbar fracture, randomly divided into observation group in 44 cases, control group in 44 cases, compared two groups patients’ clinical effects. Results After vertebroplasty treatment, the observation group’s excellent rate was 90.91%, and the control group after traditional conservative treatment, the excellent rate was 54.55%, the clinical effect of observation group was better than control group. Conclusion Vertebroplasty in the treatment of thoracolumbar fractures had exact clinical effect, worthy for clinical use.%  目的探讨椎体成形术治疗胸腰椎骨折的临床效果.方法选取本院收治的88例胸腰椎骨折患者,随机将这些患者分成观察组44例,对照组44例,比较两组患者治疗后的临床效果.结果观察组经椎体成形术治疗,效果优良率为90.91%,对照组经传统保守治疗,效果优良率为54.55%,观察组临床效果明显优于对照组.结论椎体成形术在治疗胸腰椎骨折方面具有确切的临床效果,值得临床推广使用.

  16. Smallness kerf pedicle screw internal fixation cure thoracolumbar fracture%小切口椎弓根钉棒内固定治疗胸腰椎骨折

    Institute of Scientific and Technical Information of China (English)

    胡红耘

    2009-01-01

    Objective Smallness kerr rout of retreat pedicle screw posting restoration fixing cure thoracolum-bar fracture. Methods Versus 12 example thoracolumbar fracture adopt smallness keff micro-wound rout of retreat pedicle screw posting restoration fixing technology. Results 12 example fracture patient follow-up survey 8 loaf months to 2 year, average long dozen month, fracture restoration satisfaction, pedicle screw position all right, without height lost, without looseness,lapse sever natl. Conclusion Thoracolumbar fracture met pedicle screw push off resto-ration internal fixation, reestablish physiologic protrusion, operation kerf smallness, esthetic appearance, hemorrhage fewness wound reaction smallness, in favor of skill post-recovery.%目的 探讨椎弓根钉棒置入复位固定治疗胸腰椎骨折的手术入路方法.方法 对12例胸腰椎骨折的病例采用小切口微创后路椎弓根钉棒置入复位固定技术.结果 12例骨折患者随访8个月至2年,平均13个月,骨折复位满意,椎弓根钉棒位置良好,无高度丢失、无松动、失效、断钉.结论 胸腰椎骨折可选择后路小切口术式行椎弓根钉棒撑开复位内固定,重建生理前突,手术切口小、美观、出血少、创伤反应小,有利于术后恢复.

  17. Value of the magnetic resonance imaging in the assessment of the circumferential resection margin (CRM) in patients with rectal cancer

    International Nuclear Information System (INIS)

    Purpose: To determine whether magnetic resonance imaging (MRI) can predict tumor involvement of the circumferential resection margin (CRM) in patients with rectal cancer. Materials and methods: Between april 2005 and march 2008, 70 consecutive patients (mean age 64, range 34-78 years), 40 F and 30 M, with endoscopy and biopsy- proven middle and lower rectal cancer. Non contrast enhanced MRI was performed on a Siemens Avanto 1.5 T. A phased array coil was used and T2 weighted thin section sequences (TR/TE 4200/88, slice thickness 3mm, gap 0, matrix 256 x 256, field of view 150 x 150 mm) were performed in axial, sagittal and coronal orientations. Patients received a 150 ml glycerin enema before examination. No air insufflations or intramuscular antispasmodic was used. The shortest distance from the tumor edge to the circumferential margin was measured. A distance ≤ ?2 mm, analyzed in axial slices, was considered as definition of circumferential margin involvement. Results: The CRM was 2 mm in both MRI and histopathological findings in 26 patients. In 8 cases the CRM was shorter on MRI than in histopathological sections. In 32 patients the CRM was respected in both exams and 4 patients were considered positive on histopathological findings but negative in MRI. The sensitivity, specificity, positive and negative predictive values for prediction of tumor involvement of CRM were 86%, 80%, 76% and 88%, respectively. Conclusions: MRI gives reliable information on tumor involvement of the CRM in patients with rectal cancer. This may provide accurate identification of an important prognostic risk factor in patients prior to surgical treatment. (authors)

  18. Contribution to the Evaluation of the Circumferentially-Cracked Round Bar for Fracture Toughness Determination of Reactor Pressure

    International Nuclear Information System (INIS)

    The subject of this PhD dissertation is the use of the Circumferentially-Cracked Round Bar (CRB) for fracture toughness measurements. The main advantages of CRB are the relatively small size requirements of the testing specimens, the low cost to machine the specimen, the rotating bending fatigue allowing for easy precracking of specimens, the use of standard tensile test fixture and the axisymmetry of the specimen that avoids time consuming 3D finite element calculations. An in-depth study of the most widely used precracking technique for CRB, namely the rotating bending fatigue, is made

  19. Fracture Toughness (K1C) evaluation for dual phase medium carbon low alloy steels using circumferential notched tensile (CNT) specimens

    OpenAIRE

    Kenneth Kanayo Alaneme

    2011-01-01

    The fracture behavior of dual phase medium carbon low alloy steels produced using two different chemical compositions (A - 0.34C, 0.75Mn, 0.12Cr, 0.13Ni steel and B - 0.3C, 0.97Mn, 0.15Cr steel) was investigated using circumferential notched tensile (CNT) specimens. Intercritical treatments were performed on samples with composition A by 1) austenitizing at 860 °C for 1 hour cooling in air, then treating at 770 °C for 30 minutes before oil quenching; 2) austenitizing at 860 °C for 1 hour quen...

  20. Influence of the circumferential speed of a resin bond grinding wheel on the properties of a ground aspheric surface

    Czech Academy of Sciences Publication Activity Database

    Matoušek, O.; Tomka, David; Procháska, František; Polák, Jaroslav

    Vol. 9442. Bellingham: SPIE-INT SOC OPTICAL ENGINEERING, 2015 - (Kovačičinová, J.; Vít, T.), 94420T-94420T. (SPIE). ISBN 978-1-62841-557-5. ISSN 0277-786X. [Optics and Measurement Conference 2014 (OaM 2014). Liberec (CZ), 07.10.2014-10.10.2014] R&D Projects: GA MŠk(CZ) LO1206 Institutional support: RVO:61389021 Keywords : Aspheric grinding * resin bond * tool circumferential speed optimization Subject RIV: JP - Industrial Processing http://spie.org/Publications/Proceedings/Paper/10.1117/12.2175630

  1. Contribution to the Evaluation of the Circumferentially-Cracked Round Bar for Fracture Toughness Determination of Reactor Pressure

    Energy Technology Data Exchange (ETDEWEB)

    Scibetta, M

    1999-06-01

    The subject of this PhD dissertation is the use of the Circumferentially-Cracked Round Bar (CRB) for fracture toughness measurements. The main advantages of CRB are the relatively small size requirements of the testing specimens, the low cost to machine the specimen, the rotating bending fatigue allowing for easy precracking of specimens, the use of standard tensile test fixture and the axisymmetry of the specimen that avoids time consuming 3D finite element calculations. An in-depth study of the most widely used precracking technique for CRB, namely the rotating bending fatigue, is made.

  2. 胸腰结合段侧面血管的影像解剖学研究%The Imaging Research for Thoracolumbar Spine Lateral Vascular Anatomy

    Institute of Scientific and Technical Information of China (English)

    欧阳志和; 欧阳厚淦

    2011-01-01

    Purpose To provide the anatomic basis of imaging for the segmental vessels of the thoracolumbar spine side and measure the distance between two adjacent segmental arteries in the three-dimensional images. Materials and Methods After conducting angiography for 30cases of normal adults through the ulnar vein, carring out thoracolumbar CT scans. In the image observation: The course and adjacent relationship of the segmental vessels. Measuring range: the distance between the the upper and lower segmental arteries of the middle line of spine side. Results We could observe the course and the adjacent relationship of thoracolumbar spine lateral vascular. That between the upper and lower segmental vessels consists a relatively non-vascular nerve safe zone where the intervertebral space locates. And we surveyed the related datas. Conclusion Three-dimensional reconstruction of CT images can effectively observe the course and adjacent relationship of the thoracolumbar spinal lateral segmental artery, and can accurately measure the safe zone.%目的:为脊柱胸腰结合段侧面的节段血管走行、'变异及毗邻关系提供影像学解剖基础.资料和方法:对32例正常成人经肘静脉造影后行脊柱胸腰段CT扫描,在图像上观察节段动脉的走行特点并在脊柱侧面正中线上对上、下位节段动脉之间的距离进行测量.结果:在影像三维图像上可观察脊柱胸腰段侧面,节段动脉较为恒定地存在并走行于相应椎体侧面中央浅沟内.上、下位节段动脉间构成了一个相对无血管、神经的安全区,椎间隙恰好位于该安全区中部.并且测量了相关数据,左右两侧比较无显著性差异(P>0.05).结论:CT三维重建图像能有效观察脊柱胸腰结合段侧面节段动脉的走行及毗邻关系,并能准确测量出安全区.

  3. Optimal patient positioning for ligamentotaxis during balloon kyphoplasty of the thoracolumbar and lumbar spine.

    LENUS (Irish Health Repository)

    Cawley, D T

    2011-06-01

    Percutaneous balloon kyphoplasty aims to restore vertebral height, correct angular deformity and stabilize the spine in the setting of vertebral compression fractures. The patient is positioned prone with supports under the iliac crests and upper thorax to allow gravity to extend the spine. In the treatment of lumbar fractures, we evaluated patient positioning with the contribution of hip extension to increase anterior ligamentotaxis, thus facilitating restoration of vertebral height. Our positioning technique created a mean anterior height increase from 72% to 78% of the average height of the cranial and caudal vertebrae (p=0.037). Balloon inflation did not significantly further increase anterior or posterior vertebral height, or Cobb angle.

  4. 经前路与后路手术治疗胸腰段骨折伴脊髓损伤临床对比研究%Clinical Comparative Study of the Effect Between Anterior and Posterior Surgical Treatment for Thoracolumbar Fracture with Spinal Cord Injury

    Institute of Scientific and Technical Information of China (English)

    袁小平

    2014-01-01

    Objective To study and analyze the clinical effects of anterior and posterior surgical treatments for thoracolumbar frac-ture with spinal cord injury. Methods 100 cases confirmedly diagnosed with thoracolumbar fracture with spinal cord injury in our hospital from March 2011 to March 2014 were selected as the subjects, and randomly divided into the control group and the ob-servation group with 50 cases in each in the case of informed consent. The control group was given the anterior surgery, and the observation group was given the posterior surgery. The patients were followed up for knowing the specific circumstances of them. The Frankel grading of spinal cord injury and spinal deformity angle correction of the two groups were observed and analyzed comparatively. Results The result of the study showed that, the difference in Frankel grading of spinal cord injury of the two groups before and after treatment was statistically significant (P0.05);the difference in spinal deformity angle correction of the two groups before and after treatment was sta-tistically significant (P0.05). Conclusion For patients with thoracolumbar fractures and spinal cord injury, both anterior and posterior surgical treatments have high clinical val-ue, the effects are significant, which can effectively correct the deformity after spinal fractures and improve the neurological func-tion, and are worthy of vigorous promotion clinically.%目的:研究分析经前路与后路手术治疗胸腰段骨折伴脊髓损伤的临床效果。方法选取2011年3月-2014年3月在该院确诊收治的100例胸腰段骨折伴脊髓损伤患者作为研究对象,在患者知情同意的情况下按数字随机分为对照组和观察组各50例。给予对照组患者前路手术治疗,而观察组患者给予后路手术治疗。术后对患者的具体情况进行随访,观察两组患者的Frankel脊髓损伤分级、脊柱畸形角的矫正情况,并作对比分析。结果研究结果显示

  5. Depression of the Thoracolumbar Posterior Vertebral Body on the Estimation of Cement Leakage in Vertebroplasty and Kyphoplasty Operations

    Institute of Scientific and Technical Information of China (English)

    Hao Chen; Pu Jia; Li Bao; Fei Feng; He Yang; Jin-Jun Li; Hai Tang

    2015-01-01

    Background: The cross-section ofthoracolumbar vertebral body is kidney-shaped with depressed posterior boundary.The anterior wall of the vertebral canal is separated from the posterior wall of the vertebral body on the lateral X-ray image.This study was designed to determine the sagittal distance between the anterior border of the vertebral canal and the posterior border of the vertebral body (DBCV) and to analyze the potential role of DBCV in the estimation of cement leakage during percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP).Methods: We retrospectively recruited 233 patients who had osteoporotic vertebral compression fractures and were treated with PVP or PKP.Computed tomography images ofT1 l-L2 normal vertebrae were measured to obtain DBCV.The distance from cement to the posterior wall of the vertebral body (DCPW) of thoracolumbar vertebrae was measured from C-ann images.The selected vertebrae were divided into two groups according to DCPW, with the fracture levels, fracture grades and leakage rates of the two groups compared.A relative operating characteristic (ROC) curve was applied to determine whether the DCPW difference can be used to estimate the degree of cement leakage.The data were processed by statistical software SPSS version 21.0 using independent sample t-test and Chi-square tests.Results: The maximum DBCV was 6.40 mm and the average DBCV was 3.74 ± 0.95 mm.DBCV appeared to be longer in males than in females, but the difference was not statistically significant.The average DCPW of type-B leakage vertebrae (2.59 ± 1.20 mm) was shorter than that of other vertebrae (7.83 ± 2.38 mm, P < 0.001).The leakage rate of group DCPW ≤6.40 mm was lower than that of group DCPW >6.40 mm for type-C and type-S, but much higher for type-B.ROC curve revealed that DCPW only has a predictive value for type-B leakage (area under the curve: 0.98, 95% confidence interval: 0.954.99, P < 0.001), and when the cut-offvalue was 4.05 mm, the

  6. The Retrospective Analysis of Posterior Short-Segment Pedicle Instrumentation without Fusion for Thoracolumbar Burst Fracture with Neurological Deficit

    Directory of Open Access Journals (Sweden)

    Zhouming Deng

    2014-01-01

    Full Text Available This study aims to investigate the efficacy of posterior short-segment pedicle instrumentation without fusion in curing thoracolumbar burst fracture. All of the 53 patients were treated with short-segment pedicle instrumentation and laminectomy without fusion, and the restoration of retropulsed bone fragments was conducted by a novel custom-designed repositor (RRBF. The mean operation time and blood loss during surgery were analyzed; the radiological index and neurological status were compared before and after the operation. The mean operation time was 93 min (range: 62–110 min and the mean intraoperative blood loss was 452 mL in all cases. The average canal encroachment was 50.04% and 10.92% prior to the surgery and at last followup, respectively (P<0.01. The preoperative kyphotic angle was 17.2 degree (±6.87 degrees, whereas it decreased to 8.42 degree (±4.99 degrees at last followup (P<0.01. Besides, the mean vertebral body height increased from 40.15% (±9.40% before surgery to 72.34% (±12.32% at last followup (P<0.01. 45 patients showed 1-2 grades improvement in Frankel’s scale at last followup. This technique allows for satisfactory canal clearance and restoration of vertebral body height and kyphotic angle, and it may promote the recovery of neurological function. However, further research is still necessary to confirm the efficacy of this treatment.

  7. 胸腰段椎间盘突出症与休门病%Thoracolumbar disc herniation and Scheuermann's disease

    Institute of Scientific and Technical Information of China (English)

    石泽锋; 陈仲强; 刘宁; 齐强

    2011-01-01

    目的 探讨胸腰段椎间盘突出症(thoracolumbardisc herniation,TLDH)和休门病的内在联系以及休门病在TLDH发病中的作用.方法 2006年6月至2010年6月,以45例因TLDH(T10-11~L2-3)手术的患者作为研究组(TLDH组),及同期手术的低位(L3-4~L5S1)腰椎间盘突出症(1umbardisc herniation,LDH)患者中随机抽取45例作为对照组(LDH组).通过复习其CT、MRI和X线片,对比两组合并休门病和各种影像学休门样改变的比例,并比较两组的胸腰段后凸角度.进一步在TLDH组内部分别对比存在各种休门样改变的节段和无休门样改变节段合并椎间盘突出的比例.结果 TLDH组97.8%(44/45)的患者均合并休门病,LDH组仅为26.7%(12/45;x2=48.403,P=0.000).TLDH组出现各种休门样改变的比例均高于LDH组,分别为许莫结节66.7%(30/45)和15.6%(7/45;x2=24.278,P=0.000),终板不规则88.9%(40/45)和15.6%(7/45;x2=48.496,P=0.000),椎体后缘离断75.6%(34/45)和13.3%(6/45;x2=35.280,P=0.000),相邻椎体楔形变93.3%(42/45)和0%(x2=78.750,P=0.000).TLDH组患者平均胸腰段后凸角15.8°±6.9°,LDH组为4.8°±4.0°(t=7.703,P<0.001).TLDH组内,存在许莫结节(32.8%,39/119;x2=9.276,P=0.002),终板不规则(50.0%,55/110;x2=22.255,P=0.000),椎体后缘离断(100%,40/40;x2=69.421,P=0.000)和椎体楔形变(39.5%,58/147;x2=14.631,P=0.000)的节段发生椎间盘突出的比例均高于无休门样改变的节段(9.1%,4/44).结论 胸腰段椎间盘突出症与休门病关系密切,前者可能是后者的一种表现.许莫结节、终板不规则、椎体楔形变,尤其是椎体后缘离断,与椎间盘突出的发生有关.%Objective To explore the relationship between thoracolumbar disc herniation (TLDH) and Scheuermann1's disease (SD),as well as the role of SD in the etiology of TLDH.Methods From June 2006 to June 2010,45 patients with TLDH (T10-11-L2-3) underwent surgery in our department.Forty-five patients with lower lumbar disc herniation (LDH,L3-4-L5S1

  8. Quantitative circumferential strain analysis using adenosine triphosphate-stress/rest 3-T tagged magnetic resonance to evaluate regional contractile dysfunction in ischemic heart disease

    International Nuclear Information System (INIS)

    Highlights: • Infarcted segments could be differentiated from non-ischemic and ischemic segments with high sensitivity and specificity under at rest conditions. • The time-to-peak circumferential strain values in infarcted segments were more significantly delayed than those in non-ischemic and ischemic segments. • Both circumferential strain and circumferential systolic strain rate values under ATP-stress conditions were significantly lower in ischemic segments than in non-ischemic segments. • Subtracting stress and rest circumferential strain had a higher diagnostic capability for ischemia relative to only utilizing rest or ATP-stress circumferential strain values. • A circumferential strain analysis using tagged MR can quantitatively assess contractile dysfunction in ischemic and infarcted myocardium. - Abstract: Purpose: We evaluated whether a quantitative circumferential strain (CS) analysis using adenosine triphosphate (ATP)-stress/rest 3-T tagged magnetic resonance (MR) imaging can depict myocardial ischemia as contractile dysfunction during stress in patients with suspected coronary artery disease (CAD). We evaluated whether it can differentiate between non-ischemia, myocardial ischemia, and infarction. We assessed its diagnostic performance in comparison with ATP-stress myocardial perfusion MR and late gadolinium enhancement (LGE)-MR imaging. Methods: In 38 patients suspected of having CAD, myocardial segments were categorized as non-ischemic (n = 485), ischemic (n = 74), or infarcted (n = 49) from the results of perfusion MR and LGE-MR. The peak negative CS value, peak circumferential systolic strain rate (CSR), and time-to-peak CS were measured in 16 segments. Results: A cutoff value of −12.0% for CS at rest allowed differentiation between infarcted and other segments with a sensitivity of 79%, specificity of 76%, accuracy of 76%, and an area under the curve (AUC) of 0.81. Additionally, a cutoff value of 477.3 ms for time-to-peak CS at rest

  9. Quantitative circumferential strain analysis using adenosine triphosphate-stress/rest 3-T tagged magnetic resonance to evaluate regional contractile dysfunction in ischemic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masashi, E-mail: m.nakamura1230@gmail.com [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan); Kido, Tomoyuki [Department of Radiology, Saiseikai Matsuyama Hospital, Ehime 791-0295 (Japan); Kido, Teruhito; Tanabe, Yuki; Matsuda, Takuya; Nishiyama, Yoshiko; Miyagawa, Masao; Mochizuki, Teruhito [Department of Radiology, Ehime University Graduate School of Medicine, Shitsukawa, Toon-city, Ehime 791-0295 (Japan)

    2015-08-15

    Highlights: • Infarcted segments could be differentiated from non-ischemic and ischemic segments with high sensitivity and specificity under at rest conditions. • The time-to-peak circumferential strain values in infarcted segments were more significantly delayed than those in non-ischemic and ischemic segments. • Both circumferential strain and circumferential systolic strain rate values under ATP-stress conditions were significantly lower in ischemic segments than in non-ischemic segments. • Subtracting stress and rest circumferential strain had a higher diagnostic capability for ischemia relative to only utilizing rest or ATP-stress circumferential strain values. • A circumferential strain analysis using tagged MR can quantitatively assess contractile dysfunction in ischemic and infarcted myocardium. - Abstract: Purpose: We evaluated whether a quantitative circumferential strain (CS) analysis using adenosine triphosphate (ATP)-stress/rest 3-T tagged magnetic resonance (MR) imaging can depict myocardial ischemia as contractile dysfunction during stress in patients with suspected coronary artery disease (CAD). We evaluated whether it can differentiate between non-ischemia, myocardial ischemia, and infarction. We assessed its diagnostic performance in comparison with ATP-stress myocardial perfusion MR and late gadolinium enhancement (LGE)-MR imaging. Methods: In 38 patients suspected of having CAD, myocardial segments were categorized as non-ischemic (n = 485), ischemic (n = 74), or infarcted (n = 49) from the results of perfusion MR and LGE-MR. The peak negative CS value, peak circumferential systolic strain rate (CSR), and time-to-peak CS were measured in 16 segments. Results: A cutoff value of −12.0% for CS at rest allowed differentiation between infarcted and other segments with a sensitivity of 79%, specificity of 76%, accuracy of 76%, and an area under the curve (AUC) of 0.81. Additionally, a cutoff value of 477.3 ms for time-to-peak CS at rest

  10. The Aerodynamic Performance of an Over-the-Rotor Liner With Circumferential Grooves on a High Bypass Ratio Turbofan Rotor

    Science.gov (United States)

    Bozak, Richard F.; Hughes, Christopher E.; Buckley, James

    2013-01-01

    While liners have been utilized throughout turbofan ducts to attenuate fan noise, additional attenuation is obtainable by placing an acoustic liner over-the-rotor. Previous experiments have shown significant fan performance losses when acoustic liners are installed over-the-rotor. The fan blades induce an oscillating flow in the acoustic liners which results in a performance loss near the blade tip. An over-the-rotor liner was designed with circumferential grooves between the fan blade tips and the acoustic liner to reduce the oscillating flow in the acoustic liner. An experiment was conducted in the W-8 Single-Stage Axial Compressor Facility at NASA Glenn Research Center on a 1.5 pressure ratio fan to evaluate the impact of this over-the-rotor treatment design on fan aerodynamic performance. The addition of a circumferentially grooved over-the-rotor design between the fan blades and the acoustic liner reduced the performance loss, in terms of fan adiabatic efficiency, to less than 1 percent which is within the repeatability of this experiment.

  11. Estimation schemes to evaluate elastic-plastic J and COD for throughwall circumferentially cracked elbow under closing moment

    International Nuclear Information System (INIS)

    Leak-before-break (LBB) assessment of primary heat transport piping of nuclear reactors involves detailed fracture assessment of pipes and elbows with postulated throughwall cracks. Fracture assessment requires the calculation of elastic-plastic J-integral and crack opening displacement (COD)1 for these piping components. Analytical estimation schemes to evaluate elastic-plastic J-integral and COD simplify the calculations. These types of estimation schemes are available for pipes with various crack configurations subjected to different types of loading. However, no such schemes are available for throughwall circumferentially cracked elbow (or pipe bend), an important component for LBB analysis. In this paper, simple J and COD estimation schemes are proposed for throughwall circumferentially cracked elbow subjected to closing bending moment. The ovalisation of elbow cross section has a significant bearing on its fracture behavior. Therefore, unlike conventional deformation theory plasticity analysis, incremental flow theory is adopted considering both material and geometric non-linearities in the development of the proposed estimation schemes. Although it violates Ilyushin's theorem, it has been shown that the resulting estimation schemes is still reasonably accurate for engineering purposes. Finally, experimental/numerical validation has been provided by comparing the J-integral and COD between numerical/test data and predictions of the proposed estimation schemes. (authors)

  12. Transpedicular fixation and fusion-arthrodesis circumferential for the treatment of lumbosacral spondylolisthesis of high degree - Multi centric experience

    International Nuclear Information System (INIS)

    The objective is to present the high-grade lumbosacral spondylolisthesis surgical experience. Spondylolisthesis causes chronic disabling pain, postural alteration and/or motor and sensory deficits in the lower extremities. Surgical stabilization is recommended in symptomatic adult and even in children or adolescents without symptoms because of the deformity progression potential. Stabilization can be done with or without reduction of the slippage; reduction implies neurological damage risk, bone (loosening) or implant (rupture) failure. Many authors recommended to do an in situ circumferential fusion arthrosis (inter body and inter transverse) associated with a transpedicular fixation in order to minimize the described risk. Eight patients were operated from 1993 to 2002. spondylolisthesis was analyzed according to clinical presentation, neurological dysfunction, postural alterations (slip angle, sacral inclination) complications and follow up. During follow up solid fusion was obtained with a better neurological function in all cases. One patient presented with a drop foot that reverted posteriorly; other patient had a superficial infection of the wound that was controlled. Slip angle improved between 8 - 42 and sacral inclination to 20 degrades. Present technique is recommended because it can be done a circumferential in situ arthrodesis in a single stage operation

  13. Refinement and evaluation of crack-opening-area analyses for circumferential through-wall cracks in pipes

    International Nuclear Information System (INIS)

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet impingement shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. These leak rates depend on the crack-opening area of a through-wall crack in the pipe. In addition to LBB analyses, which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section 11. This study was requested by the NRC to review, evaluate, and refine current analytical models for crack-opening-area analyses of pipes with circumferential through-wall cracks. Twenty-five pipe experiments were analyzed to determine the accuracy of the predictive models. Several practical aspects of crack-opening such as; crack-face pressure, off-center cracks, restraint of pressure-induced bending, cracks in thickness transition regions, weld residual stresses, crack-morphology models, and thermal-hydraulic analysis, were also investigated. 140 refs., 105 figs., 41 tabs

  14. Thoracolumbar fracture dislocations treated by posterior reduction interbody fusion and segmental instrumentation

    Directory of Open Access Journals (Sweden)

    Xiao-Bin Wang

    2014-01-01

    Materials and Methods: A retrospective review of 30 patients who had sustained fracture dislocation of the spine and underwent single stage posterior surgery between January 2007 and December 2011 was performed. All the patients underwent single stage posterior pedicle screw fixation, decompression and interbody fusion. Demographic data, medical records and radiographic images were reviewed thoroughly. Results: Ten females and 20 males with a mean age of 39.5 years were included in this study. Based on the AO classification, 13 cases were Type B1, 4 cases were B2, 4 were C1, 6 were C2 and 3 cases were C3. The average time of the surgical procedure was 220 min and the average blood loss was 550 mL. All of the patients were followed up for at least 2 years, with an average of 38 months. The mean preoperative kyphosis was 14.4° and reduced to -1.1° postoperatively. At the final followup, the mean kyphosis was 0.2°. The loss of correction was small (1.3° with no significant difference compared to postoperative kyphotic angle (P = 0.069. Twenty seven patients (90% achieved definitive bone fusion on X-ray or computed tomography imaging within 1 year followup. The other three patients were suspected possible pseudarthrosis. They remained asymptomatic without hardware failure or local pain at the last followup. Conclusion: Single stage posterior reduction using segmental pedicle screw instrumentation, combined with decompression and interbody fusion for the treatment of thoracic or lumbar fracture-dislocations is a safe, less traumatic and reliable technique. This procedure can achieve effective reduction, sagittal angle correction and solid fusion.

  15. Comparative study of the clinical effect and safety of anterior surgical approach and posterior surgical approach in the treatment of thoracolumbar spinal fracture

    Directory of Open Access Journals (Sweden)

    Dengfeng Zhang

    2015-01-01

    Full Text Available The clinical effect and safety of the anterior surgical approach and posterior surgical approach in the treatment of thoracolumbar spinal fracture was compared. Retrospective analyses of clinical data for 91 patients observed from March 2010 to September 2014 were made. The pre-operation and post-operation comparisons between two sets of Cobb’s angle, affected vertebra height, Frankel’s classification of spinal nerves, motion functions, and tactile functions showed statistically significant differences (P<0.05. After having the operation, the Cobb’s angle and affected vertebra height of the patient in the anterior approach group were both significantly higher than that of patients in the posterior approach group (P<0.05. The bone graft fusion rate of the patients in the anterior approach group 3 months after operation was higher than that of patients in the control group while the status of complications was worse than that of patients in the posterior approach group, both with a remarkable difference (P<0.05. Both the anterior surgical approach and posterior surgical approach have good clinical outcome for spinal fractures but they all have their respective adaption diseases. The key in the treatment of thoracolumbar spinal fractures lies in choosing proper operative approach.

  16. Neurological complications in treatment of severe thoracolumbar spinal deformity with one stage posterior vertebral column resection%I期后路全脊椎切除治疗重度胸腰椎畸形的神经系统并发症

    Institute of Scientific and Technical Information of China (English)

    吕国华; 王孝宾; 王冰; 李晶; 康意军; 邓幼文; 刘伟东

    2011-01-01

    Objective To analyze the neurological complications in treatment of severe thoracolumbar spinal deformity with one stage posterior vertebral column resection (pVCR) and discuss the related risk factors. Methods There were 67 patients with severe thoracolumbar spinal deformity who underwent one-stage pVCR from February 2000 to September 2010.There were 29 males and 38 females at an average age of 31.4 years old(range,14-62 years).There were 21 patients at age less than 18 years old and 46 at age more than 18 years old.Patients were divided into four pathological types:severe scoliosis group(n=11,mean Cobb angle 90.4°),kyphoscoliosis group(n=25,mean scoliosis 94.5°,and mean kyphosis 65.5°),angular kyphosis group(n=28,mean kyphosis 74.3°)and global kyphosis group(n=3,mean kyphosis 91.1°).of all the patients,59 patients underwent primary surgery and eight underwent revision surgery.Surgical methods included posterior apex vertebral column resection,segemental pedicle screw fixation and correction as well as 360° bone fusion.Neurological complication was statistically analyzed. Results The average follow-up was 14 months (range,3-69 months),which showed severe neurologic complication in eight patients(11.9%)after surgery.Severe neurologic complication occurred in three patients (4.5%),among whom one patient presented delayed complete paraplegia 23 hours after surgery.Five patients had mild neurologic deficits(7.5%),the incidence of which was higher than 23.1%for thoracic osteotomy (P0.05). Conclusions pVCR is an effective surgical method for the correction of severe thoracolumbar spinal deformity.The neurological complications,however,should be paid attention to the surgeons.The risk factors for neurologic complications include improper manipulation,massive blood losing,preoperative neurologic compromise,osteotomy at thoracic rein,multi-level vertebrectomy,revision surgery and severe kyphosis.%目的 探讨应用I期后路全脊椎切除治疗重度胸腰椎畸

  17. The contrasts of thoracolumbar fracture's curative effect between vertebroplasty with short-segment pedicle instrument and simple internal fixation%短节段内固定加椎体成形术与单纯内固定治疗胸腰椎骨折疗效对比

    Institute of Scientific and Technical Information of China (English)

    陈光华; 赵静; 李永民; 李颉

    2011-01-01

    [Objective] To compare the effects of short-segment pedicle screw fixation with vertebroplasty and single short-segment pedicle screw fixation in patients with thoracolumbar vertebrae fractures. [Methods] Forty patients with thoracolumbar vertebrae fractures were treated with short-segment pedicle screw fixation. Fractures in Group A (n =20) were reinforced with vertebroplasty. Group B patients (n =20) were not treated with vertebroplasty. [Results] Kyphosis correction was achieved in two groups. During the follow-up period, kyphosis correction was maintained in Group B, but lost in Group A (Group A, -5.82%±1.34%, Group B, 0%) Group B had better results than Group A in the release of pain. (Group A, 90%, Group B, 100%). There was 1 patient experienced instrument failure in Group A (5%), but there was none in Group B (0%). [Conclusion] Short-segment pedicle screw fixation with vertebroplasty for the treatments of patients with thoracolumbar vertebrae fractures may achieve the stabilization of post column in spine, reproduce the biomechanic function of anterior and middle column. It is a better procedure than single short-segment pedicle screw fixation.%目的 比较短节段内固定加椎体成形术与单纯内固定治疗胸腰椎骨折疗效.方法 40例患者随机分两组,A组(n=20)采用单纯短节段椎弓根内固定,B组(n=20)采用短节段内固定加椎体成形术治疗胸腰椎骨折.结果 两组病例的术后后凸畸形均较术前明显矫正,但术后随访中两组伤椎矫正度丢失程度有显著差异.丢失率A组(-5.82%±134%)、B组(0%).两组病例的术后疼痛缓解程度有显著差异,A组缓解率(90%)、B组缓解率(100%)内固定失效比A组有1例发生断钉,失效率为(5%),B组未见内固定失效,失效率为(0%).结论 短节段内固定加椎体成形术治疗胸腰椎骨折可提高脊柱后结构稳定性,重建脊柱前中柱生物力学功能,较单纯内固定治疗胸腰椎骨折疗效好.

  18. Numerical simulation and experimental investigation of temperature distribution in the circumferentially butt GTAW of Incoloy 800H pipes

    International Nuclear Information System (INIS)

    The multi-pass circumferential butt GTAW process of Incoloy 800H pipes was modelled with the FEM in 3D. The element birth and death technique was used for the addition of filler material. Goldak model was used to simulate the distribution of arc heat source. The validation of the simulation model was carried out based on the precise temperature measurements within the HAZ of the welds by thermocouples as well as metallographic characterisation of the cross section of the welds. A good agreement was found between the simulation and experimental results for both thermal field and weld zone shape. The present model showed that increasing the heat input resulted in a wider weld zone as well as a higher HAZ peak temperature. These effects were related to the net heat input and not to either welding current or welding speed, individually. The developed simulation model is a useful tool to investigate the welding thermal regime and the weld pool profile.

  19. Estimates of Partial Safety Factors of Circumferential Through-Wall Cracked Pipes Based on Elastic-Plastic Crack Initiation Criterion

    International Nuclear Information System (INIS)

    Efforts are presently underway for developing an optimal design methodology for GEN-IV nuclear reactors based on target failure probabilities. A typical example is the system-based code, in which the results are represented in the form of partial safety factors (PSFs). Thus, a PSF is one of the crucial elements in either component design or integrity assessment based on target failure probabilities during the operation period. In the present study, a procedure for calculating the PSF of a circumferential through-wall cracked pipe based on the elastic-plastic crack initiation criterion is established, in which the importance of each input variable is assessed. Elastic-plastic J-integrals are calculated using the GE/EPRI and reference stress methods, and the PSF values are calculated using both first- and second-order reliability methods. Moreover, the effect of statistical distributions of assessment variables on the PSF is also evaluated

  20. Transverse shear effects on the stress-intensity factor for a circumferentially cracked, specially orthotropic cylindrical shell

    Science.gov (United States)

    Delale, F.; Erdogan, F.

    1977-01-01

    The problem of a cylindrical shell containing a circumferential through crack is considered by taking into account the effect of transverse shear deformations. The formulation is given for a specially orthotropic material within the confines of a linearized shallow shell theory. The particular theory used permits the consideration of all five boundary conditions regarding moment and stress resultants on the crack surface. Consequently, aside from multiplicative constants representing the stress intensity factors, the membrane and bending components of the asymptotic stress fields near the crack tip are found to be identical. The stress intensity factors are calculated separately for a cylinder under a uniform membrane load, and that under a uniform bending moment. Sample results showing the nature of the out-of-plane crack surface displacement and the effect of the Poisson's ratio are presented.

  1. Ductile fracture behavior of 3-inch diameter carbon steel piping with a circumferential through-wall crack under bending load

    International Nuclear Information System (INIS)

    In order to introduce Leak-Before-Break (LBB) concept into the piping design criteria of the LWR pressure boundary pipings, it is necessary to investigate the pipe fracture behaviors, such as fracture condition and crack opening area, etc. At JAERI, pipe fracture tests of stainless steel and STS42 carbon steel pipes under bending load have been conducted as a part of the LBB research program. This report summarizes the four-point bending test results of 3-inch diameter STS42 carbon steel pipe with a circumferential through-wall crack. Tests were carried out at room temperature. In the tests, the fracture behavior of pipes was investigated to evolute the validity of Net-section collapse criterion, J-R curve and crack opening area. It is shown that the Net-section collapse criterion gives a conservative evaluation for the fracture load of 3-inch diameter carbon steel pipes. (author)

  2. Estimations of C'' and COD for Non-Idealized Circumferential Through-Wall Crack in Cylinders under Creep Conditions

    International Nuclear Information System (INIS)

    On actual crack growth behavior of cylinders, internal surface crack develops through the wall thickness and may partially penetrate the wall thickness at its deepest point. So, the through-wall crack is formed with different crack lengths on inner and outer surface of cylinders during penetration process. These transition cracks are typically referred to as non-idealized through-wall crack (TWC). Therefore, to assess crack growth or leak rate more accurately, estimation of fracture mechanics parameter for non-idealized TWC in cylinders is necessary. In this context, some numerical works have been conducted to derive elastic and plastic fracture mechanics parameters such as stress intensity factor, J-integral and COD under elastic or plastic material behavior. In this study, estimations of C'' and COD for non-idealized circumferential TWC in cylinders under creep condition were addressed through elastic-creep finite element(FE) analyses

  3. Multicenter retrospective evaluation of the validity of the Thoracolumbar Injury Classification and Severity Score system in children.

    Science.gov (United States)

    Sellin, Jonathan N; Steele, William J; Simpson, Lauren; Huff, Wei X; Lane, Brandon C; Chern, Joshua J; Fulkerson, Daniel H; Sayama, Christina M; Jea, Andrew

    2016-08-01

    OBJECTIVE The Thoracolumbar Injury Classification and Severity Score (TLICS) system was developed to streamline injury assessment and guide surgical decision making. To the best of the authors' knowledge, external validation in the pediatric age group has not been undertaken prior to this report. METHODS This study evaluated the use of the TLICS in a large retrospective series of children and adolescents treated at 4 pediatric medical centers (Texas Children's Hospital, Children's Healthcare of Atlanta, Riley Children's Hospital, and Doernbecher Children's Hospital). A total of 147 patients treated for traumatic thoracic or lumbar spine trauma between February 1, 2002, and September 1, 2015, were included in this study. Clinical and radiographic data were evaluated. Injuries were classified using American Spinal Injury Association (ASIA) status, Denis classification, and TLICS. RESULTS A total of 102 patients (69%) were treated conservatively, and 45 patients (31%) were treated surgically. All patients but one in the conservative group were classified as ASIA E. In this group, 86/102 patients (84%) had Denis type compression injuries. The TLICS in the conservative group ranged from 1 to 10 (mean 1.6). Overall, 93% of patients matched TLICS conservative treatment recommendations (score ≤ 3). No patients crossed over to the surgical group in delayed fashion. In the surgical group, 26/45 (58%) were ASIA E, whereas 19/45 (42%) had neurological deficits (ASIA A, B, C, or D). One of 45 (2%) patients was classified with Denis type compression injuries; 25/45 (56%) were classified with Denis type burst injuries; 14/45 (31%) were classified with Denis type seat belt injuries; and 5/45 (11%) were classified with Denis type fracture-dislocation injuries. The TLICS ranged from 2 to 10 (mean 6.4). Eighty-two percent of patients matched TLICS surgical treatment recommendations (score ≥ 5). No patients crossed over to the conservative management group. Eight patients (8

  4. Effect of aging on the predicted maximum moment-carrying capacity of circumferentially cracked cast stainless steel pipe

    International Nuclear Information System (INIS)

    Cast stainless steel used in LWR primary system components such as valve bodies, pump castings, pipe fittings, and piping is susceptible to thermal embrittlement at reactor operating temperatures, 280-320 C (536-608 F). This process of thermal aging causes an increase in the hardness and ultimate tensile strength of the steel, and at the same time a decrease in toughness. Work at Argonne National Laboratories (ANL) has shown that such thermal embrittlement due to changes in the microstructure can occur during the reactor lifetime of 40 years. The effect of this thermal degradation on the load- carrying capacity of circumferentially cracked piping is the subject of this work. In this study, both lower-bound and typical values of the J-R curves and the tensile properties for CF8M and CF8A cast stainless steels, which have been artificially aged to simulate 4, 8, 16, 32, and 48 years of service at 300 C (572 F), were used to predict the maximum load-carrying capacity of circumferentially cracked pipes. The effect of aging, that is, reduced toughness and increased strength, for different pipe diameters, crack geometries [i.e., through-wall cracks (TWC) and surface cracks (SC)], and crack sizes has been investigated. Since complete stress-strain curve fits as a function of aging were not available at this time, only three analyses methods could be used. The three analyses methods used to estimate the maximum load-carrying capacity of cracked pipes were: (1) a J-estimation scheme for TWC pipes developed by Paris, (2) a Plastic-Zone-Screening Criteria (DPZP) developed at Battelle which is applicable to both TWC and SC pipe, and (3) the R6 Option 1 method developed by CEGB which is also applicable for both TWC and SC pipe

  5. CFD Study of the Hydrocarbon Boost Low-Pressure Inducer and Kicker in the Presence of a Circumferential Groove

    Science.gov (United States)

    Coker, Robert

    2011-01-01

    Results are presented of a computational fluid dynamics (CFD) study done in support of Marshall Space Flight Center's (MSFC) sub-scale water flow experiments of the Hydrocarbon Boost (HCB) Oxidizer Turbopump (OTP) being developed by the Air Force Research Laboratory (AFRL) and Aerojet. A circumferential groove may be added to the pump to reduce synchronous cavitation and subsequent bearing loads at a minimal performance cost. However, the energy may reappear as high order cavitation (HOC) that spans a relatively large frequency range. Thus, HOC may have implications for the full-scale OTP inducer in terms of reduced structural margin at higher mode frequencies. Simulations using the LOCI/Stream CFD program were conducted in order to explore the fluid dynamical impact of the groove on the low-pressure inducer and kicker. It was found that the circumferential groove has minimal head performance impact, but causes back-flowing high-swirl fluid to interact with the nearly-axial incoming fluid just above the inducer blades. The high-shear interface between the fluids is Kelvin-Helmholtz unstable, resulting in trains of low pressure regions or 'pearls' forming near the upstream edge of the groove. When the static pressure in these regions becomes low enough and they get cut by the blade leading edge, HOC is thought to occur. Although further work is required, the numerical models indicate that HOC will occur in the runbox of the AFRL/Aerojet HCB OTP. Comparisons to the ongoing water flow experiments will be discussed, as well as possible designs that may mitigate HOC while continuing to reduce synchronous cavitation. December 2011 MSS/LPS/SPS Joint Subcommittee Meeting ABSTRACT SUBMITTAL FORM

  6. The stability of growth of a through-wall circumferential crack in a cylindrical pipe subjected to bending deformation

    International Nuclear Information System (INIS)

    Tada, Paris and Gamble have used the tearing modulus approach to examine the stability of growth of a through-wall circumferential crack in a 304 stainless steel circular cylindrical pipe subject to bending deformation. They showed that crack growth is stable, in the sense that growth requires the rotation imposed at the pipe-ends to be increased, provided the pipe length is less than a critical length Lsub(c), which is given by their analysis. The Tada-Paris-Gamble analysis focuses on the question of the stability, or otherwise, of crack growth at the onset of crack extension. The analysis does not consider the possibilities that (a) instability might occur after some stable crack growth, and (b) arrest might occur after some unstable growth. A study of these aspects of the circumferential crack growth problem using the tearing modulus approach is precluded by the geometry dependence of the J-crack growth resistance curve. Consequently the present paper uses a crack tip opening angle criterion to describe crack growth, and thereby demonstrates that possibilities (a) and (b) should both occur, depending on the initial crack length and pipe length. In terms of relevance to the technologically important problem of cracking in Boiling Water Reactor piping, the important conclusion stemming from the paper's analysis is that stability of crack growth after the onset of crack extension is assured if the pipe length is less than a critical length L'sub(c). L'sub(c) is less than Lsub(c), the critical length relevant to the onset of crack extension, but it is still appreciably greater than the pipe run lengths in actual reactor piping systems, and safety against guillotine failure of a pipe is therefore generally assured. (author)

  7. Comparison between two types of"Scheuermann disease-like people": thoracolumbar disc herniation patients and healthy volunteers with radiological signs of Scheuermann's disease

    Institute of Scientific and Technical Information of China (English)

    Guo Xinhu; Chen Zhongqiang; Liu Ning; Guo Zhaoqing; Qi Qiang; Li Weishi; Zeng Yan

    2014-01-01

    Background Scheuermann's disease (SD) is a spinal disorder and includes both a classic form and an atypical form.Interestingly,its existence among the general population as well as the disc disease patients is common.One of our previous studies showed that about 18% of the hospital staff members meet the SD criteria.On the other hand,another study has demonstrated that 95.2% of the symptomatic thoracolumbar disc herniation (STLDH) patients meet the SD criteria,which suggests that STLDH is very likely a special form of SD.The purpose of this study was to discriminate the factors contributing to the development of STLDH by comparing STLDH patients with the healthy SD-like hospital staff members.Methods This is a retrospective study including 33 STLDH patients who met the SD criteria and 30 SD-like hospital staff members.The STLDH group was chosen from a group of patients who underwent surgery after a diagnosis of STLDH (T10/11-L1/2) at our hospital between June 2007 and June 2010.SD-like hospital staff members were chosen from a database created in 2007,which contained a lumbar MR and low back pain (LBP) questionnaire of 188 hospital staff members.The demographic and radiologic characteristics were compared between groups.Results There was no statistical difference in sex,age,and height between the two groups.The STLDH patients had higher body weight,boby mass index,and thoracolumbar kyphotic angle than SD-like hospital staff members.In addition,STLDH patients had more levels of Schmorl's nodes (3.5±1.7 vs.2.0±1.9,t=3.364,P=0.001) and irregular endplateson (4.0±1.9 vs.2.7±1.9,t=2.667,P=0.010) compared to the SD-like hospital staff members.Conclusions Higher body weight,higher body mass index,larger thoracolumbar kyphosis,and more Schmorl's nodes and irregular endplates on MR may be associated with the development of STLDH in "SD-like people."

  8. Acesso anterior para pacientes com fraturas traumáticas do tipo compressão do segmento toracolombar (T11 a L2 da coluna vertebral Anterior approach in patients with traumatic compression fracture type of thoracolumbar spine (T11-L2

    Directory of Open Access Journals (Sweden)

    Asdrubal Falavigna

    2007-09-01

    Full Text Available OBJETIVO: Relatar a experiência com o acesso anterior em fraturas traumáticas do tipo compressão no segmento toracolombar (T11 a L2 que foram submetidos à cirurgia pelo acesso anterior. MÉTODO: Estudo prospectivo de janeiro de 1994 a janeiro de 2004 envolvendo 32 pacientes. A presença da fusão óssea e do alinhamento foram analisadas 6 e 12 meses após a cirurgia. RESULTADOS: A idade média foi 36,53 anos, sendo 23 do sexo masculino. A vértebra mais atingida foi L1 (n=12. A maioria dos casos que internaram em ASIA/IMSOP C (n=10 e D (n=13 evoluiram para ASIA/IMSOP E. A média da deformidade angular pré-operatória foi 14,9°±7,5°, com diferença estatística (pOBJECTIVE: To describe experience with anterior access in compression fractures of thoracolumbar segment (T11 to L2 traumatic fractures that undergone anterior access surgery. METHOD: A prospective study was conducted between January 1994 and January 2004 with 32 patients. The bone fusion and thoracolumbar alignment were analyzed 6 months and 12 months after the surgery. RESULTS:The average age was 36.53 years old with 23 male patients. The most compromised vertebrae was L1 (n=12. The 23 patients that was ASIA/IMSOP C and ASIA/IMSOP D turned to ASIA/IMSOP E after 1 month (n=12 and 12 months (n=5 of surgery. The preoperative angular deformity average was 14.9°±7.5°. Statistical significance was found (p<0.0001 when compared to the 30 days postoperative value. CONCLUSION: The anterior access permits a better spinal canal decompression and angular deformity correction when compared with the posterior access alone.

  9. 椎弓根螺钉系统加自固化磷酸钙人工骨灌注治疗胸腰椎骨折%Treatment of thoracolumbar vertebrae fractures with vertebral pedicle screw system and artificial bones filled with autosolidification calcium phosphate cement

    Institute of Scientific and Technical Information of China (English)

    曾忠友; 金才益; 陆金荣; 王斌; 徐阿炳

    2001-01-01

    spinal height of the injured vertebra.  Conclusions With correct selection of operative indications and careful operations, the method with vertebral pedicle screw system and artificial bones filled with ACPC to treat thoracolumbar vertebrae fractures is an effective and safe method.

  10. 后路全脊椎截骨联合椎弓根螺钉治疗胸腰椎脊柱后凸畸形%Treatment for Thoracolumbar Kyphosis by Whole Posterior Spinal Osteotomy Combined with Pedicle Screw

    Institute of Scientific and Technical Information of China (English)

    蒋成; 蒋萍; 蔚芃

    2011-01-01

    Objective To explore the surgery assessment and clinical outcome of the treatment for thoracolumbar kyphosis by whole posterior spinal osteotomy combined with pedicle screw. Methods Fifteen patients including 11 males and 4 females with kyphosis were treated by posterior spinal osteotomy combined with pedicle screw from April 2004 to June 2010. The age of them ranged from 16 to 61 years old averaging at 49. There were 10 cases of old thoracolumbar fracture kyphosis, 3 cases of tuberculosis kyphosis, and 2 cases of poor vertebral growth. As for kyphosis vertices, there were 1 case of T9, 3 cases of T1l, 4 cases of T12, 5 cases of L1, and 2 cases of L2. Kyphosis Cobb angle ranged from 35° to 61°, averaging at 46°. Based on Franke Grade, there were 2 grade E cases, 8 grade D cases, 4 grade C cases, and 1 grade B case. Results Intraoperative blood loss was from 800 to 1 800 mL with an average of 1 000 mL) There was 1 case of left thoracic nerve root injury during operation and 1 case of lower extremity muscle strength hypoesthesia after operation. All the 15 patients were followed up for 10 to 30 months with an average time of 12 months. Six months after surgery, Cobb angle ranged from 5° to 10°, with an average correction rate of 86. 5%. Six to ten months after osteotomy, X ray showed a good bone healing condition. As for the recovery status of neurological function after surgery, All patients recovered to grade E except 1 patient who returned to grade D from grade B. No such complications as fixation without loosening, fracture or loss of correction degree occurred. Conclusion In posterior spinal osteotomy combined with pedicle screw fixation, decompression and correction can be carried out at the same time to correct a large degree of kyphosis with few complications. The clinical effect is obvious.%目的 探讨经后路全脊截骨联合椎弓根螺钉治疗胸腰椎脊柱后凸畸形的手术评估和临床疗效.方法 2004年4月-2010年6月采用后路脊

  11. Rehabilitation program for prosthetic tracheojejunal voice production and swallowing function following circumferential pharyngolaryngectomy and neopharyngeal reconstruction with a jejunal free flap

    NARCIS (Netherlands)

    L.W.J. Baijens; R. Speijer; N. Roodenburg; F.J.M. Hilgers

    2011-01-01

    The case of a 68-year-old woman with postoperative speech and swallowing problems following a circumferential pharyngolaryngectomy and neopharyngeal reconstruction with a jejunal free flap is presented. The primary tumor was an extended papillary thyroid carcinoma (pT4N0M0). For vocal restoration, a

  12. Risk factors for adjacent segment degeneration after surgical correction of degenerative lumbar scoliosis

    Directory of Open Access Journals (Sweden)

    Kee-yong Ha

    2013-01-01

    Full Text Available Background: Degenerative lumbar scoliosis surgery can lead to development of adjacent segment degeneration (ASD after lumbar or thoracolumbar fusion. Its incidence, risk factors, morbidity and correlation between radiological and clinical symptoms of ASD have no consensus. We evaluated the correlation between the occurrence of radiologic adjacent segment disease and certain imperative parameters. Materials and Methods: 98 patients who had undergone surgical correction and lumbar/thoracolumbar fusion with pedicle screw instrumentation for degenerative lumbar scoliosis with a minimum 5 year followup were included in the study. We evaluated the correlation between the occurrence of radiologic adjacent segment disease and imperative patient parameters like age at operation, sex, body mass index (BMI, medical comorbidities and bone mineral density (BMD. The radiological parameters taken into consideration were Cobb′s angle, angle type, lumbar lordosis, pelvic incidence, intercristal line, preoperative existence of an ASD on plain radiograph and magnetic resonance imaging (MRI and surgical parameters were number of the fusion level, decompression level, floating OP (interlumbar fusion excluding L5-S1 level and posterolateral lumbar interbody fusion (PLIF. Clinical outcomes were assessed with the Visual Analogue Score (VAS and Oswestry Disability Index (ODI. Results: ASD was present in 44 (44.9% patients at an average period of 48.0 months (range 6-98 months. Factors related to occurrence of ASD were preoperative existence of disc degeneration (as revealed by MRI and age at operation ( P = 0.0001, 0.0364. There were no statistically significant differences between radiological adjacent segment degeneration and clinical results (VAS, P = 0.446; ODI, P = 0.531. Conclusions: Patients over the age of 65 years and with preoperative disc degeneration (as revealed by plain radiograph and MRI were at a higher risk of developing ASD.

  13. Surgical Decompression in Dogs with Thoracolumbar Intervertebral Disc Disease and Loss of Deep Pain Perception: A Retrospective Study of 46 Cases

    Directory of Open Access Journals (Sweden)

    Puerto David A

    2005-06-01

    Full Text Available The case details and outcome after surgical decompression of 46 dogs with thoracolumbar intervertebral disc disease with loss of deep pain perception prior to surgery were reviewed. Nineteen dogs (41.3% recovered with a median follow-up period of 12.5 months. Recovery was defined as an ambulatory paraparesis, or better, with urinary and fecal continence. There was a better outcome in dogs with loss of deep pain for less than 24 hours prior to surgery (19/41; 46.3% recovered than in dogs without deep pain perception for more than 24 hours (0/5; 0% recovered. Dogs with deep pain perception present at two weeks postoperatively had significantly higher success rate (8/12; 66.7% recovered than dogs without deep pain perception at this time period (1/10; 10.0% recovered. The return of deep pain perception by two weeks postoperatively can be a useful positive prognostic indicator.

  14. 胸腰段脊柱骨折的手术治疗研究%The research of surgical treatment of thoracolumbar spine fractures

    Institute of Scientific and Technical Information of China (English)

    陈孔宁; 刘成招; 王春

    2014-01-01

    Objective To investigate the clinical efficacy of surgical posterior thoracolumbar spine fractures. Methods 80cases of thoracolumbar spine fracture patients in our hospital from February in 2011 to October in 2013 were seleted for the study. They were treated with posterior surgery, and the clinical efficacy of the patients was observed. Results All of the patients were cured of 51 cases (63.75%), 23 cases (28.75%) were effective, and total effective rate was 92.50%. After posterior surgery, tactile scores was(74.8±14.8) and sports scores was (72.1±24.8) which were excellent than treated before. There was a significant difference between them(P <0.05). Conclusion The implementation of thoracolumbar spine fractures in patients with posterior surgery can significantly improve the clinical treatment of patients with efficiency, and improve clinical symptoms of patients, moreover, posterior surgery can lower incidence of postoperative complications. It's an effective way to treat thoracolumbar spine fractures.%目的:探讨后路手术治疗胸腰段脊柱骨折的临床疗效。方法选取2011年2月~2013年10月我院接收的80例胸腰段脊柱骨折患者为研究对象,所有患者均实施后路手术治疗,观察患者手术治疗的临床疗效。结果80例患者经后路手术治疗后,显效51例(63.75%),有效23例(28.75%),总有效率为92.50%;治疗后患者手术后嗅觉评分为(74.8±14.8),运动评分为(72.1±24.8),均明显高于手术前,手术前后比较存在显著性差异(P<0.05)。结论对胸腰段脊柱骨折患者实施后路手术治疗可显著提高患者的临床治疗有效率,改善患者的临床症状,且术后并发症发生率较低,临床疗效显著,是治疗胸腰段脊柱骨折的有效方法。

  15. The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR

    Science.gov (United States)

    Chadwick, W.W., Jr.; Jonsson, Sigurjon; Geist, Dennis J.; Poland, M.; Johnson, Daniel J.; Batt, S.; Harpp, Karen S.; Ruiz, A.

    2011-01-01

    The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45–60°) toward the caldera at the surface and more gently dipping (~12–14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another.

  16. How long and low can you go? Effect of conformation on the risk of thoracolumbar intervertebral disc extrusion in domestic dogs.

    Science.gov (United States)

    Packer, Rowena M A; Hendricks, Anke; Volk, Holger A; Shihab, Nadia K; Burn, Charlotte C

    2013-01-01

    Intervertebral disc extrusion (IVDE) is a common neurological disorder in certain dog breeds, resulting in spinal cord compression and injury that can cause pain and neurological deficits. Most disc extrusions are reported in chondrodystrophic breeds (e.g. Dachshunds, Basset Hounds, Pekingese), where selection for 'long and low' morphologies is linked with intervertebral discs abnormalities that predispose dogs to IVDE. The aim of this study was to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out. Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging ± surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. Therefore, selection for longer backs and miniaturisation should be discouraged in high-risk breeds to reduce IVDE risk. In higher risk individuals, maintaining a lean body shape is particularly important to reduce the risk of IVDE. Results are reported as probabilities to aid decision-making regarding breed standards and screening programmes reflecting the degree of risk acceptable to stakeholders. PMID:23894518

  17. 后路椎弓根钉短节段固定治疗青壮年胸腰椎骨折%Treatment of Thoracolumbar Fractures of Youngsters with Short-segment Pedicle Instrumentation

    Institute of Scientific and Technical Information of China (English)

    张中伟; 胡隽宇; 龚遂良; 王卫明

    2011-01-01

    目的 比较长节段和短节段椎弓根系统治疗青壮年胸腰椎骨折的效果.观察常用的脊柱骨折分型对短节段固定预后的影响.方法 对72例胸腰椎骨折的青壮年患者随机采用后路短节段和长节段固定手术,随访观察有无内固定失败,X线检查测量12个月后的后凸矫形丢失度.短节段固定按脊柱AO分型和载荷-分享分型不同分组后,比较各组结果差异.患者术后均不予外固定.结果 随访平均矫形丢失度,长节段组为6.1°,短节段组为7.3°,差异无统计学意义(P>0.05).短节段固定中,不同脊柱AO分型(A、B、C)和载荷-分享分型(≤6、≥7)组别的矫形丢失度差异均无统计学意义(P>0.05).结论 随着器械和手术技术的进步,青壮年患者胸腰段骨折,即便是严重不稳定骨折,采用短节段椎弓根系统固定可取得较好效果,患者术后也无需外固定.%Objective To compare the effect of short-segment and long-segment pedicle instrumentation in treatment of thoraeolumbar fractures of youngsters and determine whether common classification systems can predict the radiologic outcome of short-segment fixation.Methods A retrospective radiographic review was conducted for 72 thoraeolumbar fractures of youngsters treated with long-segment (35 patients, group L) and short-segment (37 patients, group S) posterior instrumentation to determine the rate of correction loss (12 months later) and instrumentation failure. The outcome of group S in relation to the load sharing classification of spine fracture system and the AO classification of fractures system were compared. No postoperative bracing was used. Results No failures occurred in both groups. An average loss of correction of 6.1 degree (group L) and 7.3 degree (group S) were observed. No relationship was shown between loss of correction and load sharing classification (≤6 or ≥7 points), loss of correction and AO classification. Conclusion With modem

  18. Radiofrequency Ablation Mapping with Circumferential Catheter for Paroxys-mal Atrial Fibrillation Originating From the Pulmonary Veins

    Institute of Scientific and Technical Information of China (English)

    刘震; 吴书林; 杨平珍; 方咸宏; 李海杰; 陈泗林; 詹贤章; 薛玉梅

    2002-01-01

    Objectives To assessed thefeasibility and effectiveness of electrophysiologicalmapping of pulmonary veins with a circumferential 10-electrode catheter and radiofrequency catheter abla-tion therapy for patients with paroxysmal atrial fibril-lation. Background Standard mapping and ablationof focal sources of atrial fibrillation are associated withvery long procedure times and low efficacy. Mappingand ablation pulmonary veins guide with a circularcatheter could overcome these limitations. Methods16 patients [male 11, female 5, mean age (51 +14.5) years] with paroxysmal atrial fibrillation refrac-tory to antiarrhythmic drugs were included in thisgroup. A circumferential 10-electrode catheter wasused to pulmonary vein mapping during sinus rhythm orCSd pacing to determine the origin of atrial prematurecontractions. When the ablative target pulmonary veinwas found, the pulmonary vein potentials' distributionand activation were assessment pulmonary veins' ostialablation was performed at the segments showing earliestactivation of pulnonary vein potentials. The end pointwas designed: 1 ) elimination of pulmonary vein po-tential; 2) pulmonary vein potential dissociation fromatrial waves; 3) atrial ectopic beats disappear. ResultsA total of 36 pulmonary veins were ablated, in-cluding 16 left superior, 12 right superior, 7 left in-ferior and 1 right inferior. 1 pulmonary vein in 2 pa-tients was ablated, 2 pulmonary veins in 8 patientswere ablated, 3 pulmonary veins were ablated in 5patients and 4 pulmonary veins were ablated in 1 pa-tient. Procedure duration and fluoroscopy time respec-tively were 186.7 _+ 63.8 min and 51.5 + 15.0 min.During the follow-up 1- 12 months, 11 patients(68.7 % ) were free of AF without any antiarrhythmicdrugs, 2 of them were reablation, effective in 3/16(18.7%) and unsuccessful in 2/16 (12.6%) . 2cases recurred with atrial premature, 1 was treated withamiodarone and the other was repeat electrophysiologi-cal mapping and ablation, 5 cases with

  19. Wall thickness measurement using resonant phenomena of circumferential Lamb waves generated by plural transducer elements located evenly on girth

    Science.gov (United States)

    Nishino, Hideo; Iwata, Kodai; Ishikawa, Masashi

    2016-07-01

    We present a novel method of measuring the pipe wall thickness using the resonance of the circumferential (C-) Lamb wave generated by a piezoelectric ring-shaped sensor (PS). The PS is a special device for an axially propagating torsional wave; however, the C-Lamb waves are generated simultaneously as spurious signals owing to the structure of the PS. Particularly under resonant conditions, the C-Lamb waves are dominantly generated, distorting the axially propagating wave. In this method, these troublesome spurious signals are used effectively for the measurement of the wall thickness under the PS location that is a dead zone of the PS itself. The method can compensate for its drawback, namely, the dead zone problem, without using additional instruments. In this study, the mechanisms of the generation and resonance of the C-Lamb waves were first explained. Secondly, the principle of the wall thickness estimation utilizing the resonance of the C-Lamb waves was proposed. Finally, experimental verifications were carried out. The estimated wall thicknesses agreed very well (maximum 1.5% error) with those measured by a micrometer caliper under suitable resonant conditions.

  20. EXPERIMENTAL RESEARCH ON AERODYNAMIC PERFORMANCE AND EXIT FLOW FIELD OF LOW PRESSURE AXIAL FLOW FAN WITH CIRCUMFERENTIAL SKEWED BLADES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this article, the low pressure axial flow fan with circumferential skewed rotor blade, including the radial blade, the forward-skewed blade and the backward-skewed blade, was studied with experimental methods. The aerodynamic performance of the rotors was measured. At the design condition at outlet of the rotors, detailed flow measurements were performed with a five-hole probe and a Hot-Wire Anemometer (HWA). The results show that compared to the radial rotor, the forward-skewed rotor demonstrates a wider Stable Operating Range (SOR), is able to reduce the total pressure loss in the hub region and make main loading of blade accumulating in the mid-span region. There is a wider wake in the upper mid-span region of the forward-skewed rotor. Compared to the radial rotor, in the backward-skewed rotor there is higher total pressure loss near the hub and shroud regions and lower loss in the mid-span region. In addition, the velocity deficit in the wake is lower at mid-span of the backward-skewed rotor than the forward-skewed rotor.

  1. Effect of anxiety and depression on the recurrence of persistent atrial fibrillation after circumferential pulmonary vein ablation

    Institute of Scientific and Technical Information of China (English)

    YU Sheng-bo; HU Wei; ZHAO Qing-yan; QIN Mu; HUANG He; CUI Hong-ying; HUANG Cong-xin

    2012-01-01

    Background The effects of anxiety and depression on the recurrence of persistent atrial fibrillation (AF) after circumferential pulmonary vein ablation (CPVA) are not clear.Whether CPVA can alleviate the anxiety and depression symptoms of persistent AF patients is unknown.Methods One hundred and sixty-four patients with persistent AF,of which 43 treated with CPVA (CPVA group) and 103 treated with anti-arrhythmics drugs (medicine group),were enrolled.The Zung Self-Rating Anxiety Scale (SAS),and Zung Self-Rating Depression Scale (SDS) were assessed before and 12 months after treatment in all patients.Results The scores of SAS (40.33±7.90 vs.49.76±9.52,P <0.01) and SDS (42.33±8.73 vs.48.17±8.77,P <0.01)decreased 12 months after CPVA.Over 12 months follow-up,AF relapsed in 17 patients in CPVA group.Compared with the data in the recurrent group (17 patients),the scores of SAS and SDS were significantly lower in the non-recurrent group (26 patients) at baseline.The results of multivariate Logistic regression analysis showed normal scores of SAS and SDS were the independent risk factors of AF recurrence after CPVA.Conclusions Anxiety and depression increase the recurrence risk of persistent AF after CPVA.CPVA can ameliorate the anxiety and depression symptoms in patients with persistent AF.

  2. Analysis of initiation and growth of a circumferential crack in the HDR-RPV-cylinder under pressurized thermal shock

    International Nuclear Information System (INIS)

    In order to simulate a nuclear emergency cooling situation, longterm cooling tests (pressurized thermal shocks) were carried out under normal operating conditions on the reactor pressure vessel of the HDR (hot steam reactor). Naturally occuring circumferential cracks in the cylindrical part of the RPV, previously induced during cyclic thermal shock tests, were subjected to internal pressure and thermal stresses. The aim of the test was crack initiation and a limited amount of stable crack growth. Analyses, applying fracture mechanical assessment methods, were carried out before and after the test and these checked against the experimental results. To this end, comprehensive numerical analyses, investigations into material property characteristics, non-destructive and destructive (fractographical) tests were carried out. Due to the conservative assumptions, the results of the precalculation lay on the safe side; this was intended as these results served, among other aspects, as the basis for the experimental boundary condition. The post calculation which was based on the actual crack geometry, the measured cooling medium temperature and the material properties local to the crack, was in good agreement with the experimental results. Thus a tool is now available which can be successfully applied to the assessment of cracks in reactor components. (orig.)

  3. Studies on the behavior of part-through circumferential crack at intrados in elbows under in-plane bending moment

    International Nuclear Information System (INIS)

    Highlights: → Behavior of cracked elbows with part-through crack at intrados under bending moment is studied. → Some part of crack always opens and some part gets closed irrespective of mode of applied moment. → Fraction of the crack that opens basically decides the weakening effect of the cracked elbow. → Results will be useful for fracture studies and limit load estimation especially for LBB. - Abstract: This paper presents the behavior of part-through circumferential crack at intrados in elbows under in-plane bending moment. This is based on detailed non-linear (both material and geometric) finite element analysis performed on various sizes of elbows (generally used in piping industry), having different crack sizes. It is observed that some part of the crack always opens and some part gets closed irrespective of the mode of applied bending moment (opening/closing). The fraction of the crack that opens basically decides the weakening effect of the cracked elbow. It is observed that there is a threshold value of crack length and crack depth, before which no crack opening is observed under opening mode. Also as elbow becomes thinner, the threshold value of above two parameters increases. Quite interestingly, the part of crack which closes in opening mode opens under closing mode. The above mentioned study on the behavior of crack will be useful for fracture studies and limit load estimation especially when leak before break concept is to be employed.

  4. Crack-tip Stress Field of Fully Circumferential Surface Cracked Pipe Under Combined Tension and Thermal Loads

    International Nuclear Information System (INIS)

    Under excessive plasticity, the fracture toughness of a material depends on its size and geometry. Under fully yielded conditions, the stresses in a material near its crack tip are not unique but rather depend on the geometry. Therefore, the single-parameter J-approach is limited to a high-constraint crack geometry. The JQ theory has been proposed for establishing the crack geometry constraints . This approach assumes that the crack-tip fields have two degrees of freedom. In this study, the crack-tip stress field of a fully circumferential surface-cracked pipe under combined loads is investigated on the basis of the JQ theory by using finite element analysis. The combined loads are a tensile axial force and the thermal gradient in the radial direction. Q-stresses of the crack geometry and its loading state are used to determine the constraint effects. The constraint effects of secondary loading are found to be greater than those of primary loading. Therefore, thermal shock is believed to be the most severe loading condition of constraint effects

  5. The development of a posterior dynamic stabilisation implant indicated for thoraco-lumbar disc degeneration / Christopher Daniel (Chris) Parker

    OpenAIRE

    Parker, Christopher Daniel

    2013-01-01

    Posterior lumbar spinal dynamic stabilisation devices are intended to relieve the pain of spinal segments while prolonging the lifespan of adjacent intervertebral discs. This study focuses on the design of such a device, one that has the correct stiffness to stabilise the spinal segment by the correct amount. An initial literature survey covers contemporary topics related to the lumbar spine. Included topics are lumbar anatomy and kinematics, pathology of degenerative disc dise...

  6. Anatomy of thoracolumbar spinal cord anterior operation and its clinical application%胸腰段脊椎前路手术解剖与临床应用

    Institute of Scientific and Technical Information of China (English)

    曾志远; 黄杰聪; 陈小青; 蔡雅谷; 卢天祥

    2014-01-01

    Objective To Study the clinical effect of the thoracolumbar Anterior Operation (T10-L3) approach anatomy guidance anterior corpectomy decompression bone internal fixation. Methods Based on the anatomy, study of the thoracolumbar spine (T12-L3) of 10 (male 6, female 4) adult cadaveric specimens, and 30 cases of patients with spinal cord compression mainly from anterior thoracolumbar burst fracture from 2010 January to 2013 October were given scattered thoracolumbar anterior decompression bone grafting and internal fixation. Among them, 21 cases were male, 9 cases were female; age was 20-65 years old, average age was 38.5 years old. Adopted the right lateral, left approach, resection of the left eleventh rib, subtotal resection body bone graft and internal fixation of T12, or L1, L2 vertebral, in which 5 cases of T12,12 cases of L1 , 13 cases of L2, all cases were given short segment fixation separated by a vertebral body, the bleeding complications during operation time and the postoperative follow-up were comparative analyzed, bone graft fusion condition was observation. Results The average operation time was (1.8±1.3) h, the average amount of bleeding during operation was800mL(400-2100mL) , 5 cases of patients got the thoracic and abdominal injury during operation, 3 cases of thoracic drainage after operation, no damage and visceral organs of major vascular injury, and no spinal cord injury aggravated cases. The time of follow-up was 6-46 months, average time was 20 months. All cases got satisfactory reduction, there were no loss of reduction during the follow-up period, fixed position was good, no loosening or fracture, both achieved bony fusion in 5 months, the fusion rate was 100%. Conclusion For the thoracolumbar(T12-L2) vertebral burst fractures, spinal cord compression mainly from anterior spinal anterior approach, familiar with local anatomy, master the techniques of using anterior, anterior approach for subtotal resection of vertebral body bone graft and

  7. Investigation on Effect of Distance Between Two Collinear Circumferential Surface Cracks on Primary Water Stress Corrosion Crack Growth in Alloy 600TT Steam Generator Tubes

    International Nuclear Information System (INIS)

    The study investigated the effect of the distance between two collinear circumferential surface cracks on the primary stress corrosion crack (PWSCC) growth in alloy 600TT steam generator tubes using a finite element damage analysis based on the PWSCC initiation model and macroscopic phenomenological damage mechanics approach. The damage analysis method was verified by comparing the results to the previous study results. The verified method was applied to collinear circumferential surface PWSCCs. As a result, it was found that the collinear cracks showed earlier coalescence and penetration times than the a single crack, and the times increased with the distance. In addition, it is expected that penetration may occur before coalescence of two cracks if they are more than a specific distance apart

  8. Flaw Inspection of Aluminum Pipes by Non-Contact Visualization of Circumferential Guided Waves using Laser Ultrasound Generation and an Air-Coupled Sensor

    International Nuclear Information System (INIS)

    Our group had previously proposed a generation laser scanning system for visualizing ultrasound propagation on an object as an animate image, which provided visible and quick flaw inspection. Recently, we improved this system to make it completely non-contact by employing an air-coupled ultrasound transducer as a receiver instead of a contact transducer, and demonstrated the successful visualization of Lamb waves propagating on aluminum and carbon fiber reinforced plastic plates, as well as the detection of flaws. In this research, we applied this system to the non-contact visualization of circumferential guided waves on aluminum pipes. It was shown that circumferential guided waves propagating in opposite directions could be visualized separately, and that a flaw such as a slit or thinning on the inside surface of the pipe could be successfully detected even when it existed outside the scanning area

  9. Investigation on ductile fracture behavior of 3-inch diameter Type 304 stainless steel pipe with a circumferential through-wall crack

    International Nuclear Information System (INIS)

    At Japan Atomic Energy Research Institute (JAERI), a pipe fracture test program has been conducted as a part of the Leak-Before-Break (LBB) verification research in LWR pressure boundary pipings. In this program, fracture behavior and fracture criteria of the circumferentially cracked pipe have been investigated, using austenitic stainless steel pipes and carbon steel pipes. This report presents a four-point bending test results of 3-inch diameter Type 304 austenitic stainless steel pipes with circumferential through-wall crack at room temperature. Pipe fracture data were obtained from the test in regard to load-loadline displacement, crack extension, crack opening area, and so on. Discussions are performed on the effect of pipe ovalization ratio at maximum load, the application of the net-section collapse criterion, and the effect of initial crack angle, wall-thickness etc. on J-R curve. Furthermore, the crack opening area was estimated by assuming a simple crack model. (author)

  10. Current status of CHF predictions using CFD modeling technique and review of other techniques especially for non-uniform axial and circumferential heating profiles

    International Nuclear Information System (INIS)

    Highlights: • Current status of CHF predictions using CFD modeling technique. • Review of other techniques for non-uniform axial and circumferential heating profiles. • Heat transfer and wall boiling modeling are also clearly described. • Detailed description of numerical models used in two-phase flow boiling predictions. • Most of the numerical works done for predictions of CHF in literature are addressed. - Abstract: Trusted predictions of critical heat flux (CHF) value are essential for safe operation of boilers, steam generators and nuclear power reactors. Prediction techniques are numerous but they are mostly limited to uniformly heated tubes. There are separated effects on CHF, such as axial and radial heat flux distributions that have not been taken much attention. These effects are encountered during operation of boilers/steam generators and nuclear reactors. The present work is aimed at providing detailed analysis for experimental and numerical techniques used in CHF predictions focusing on non-uniform axial and circumferential heating profiles. For this purpose, heat transfer characteristics in case of CHF and heat transfer and wall boiling modeling are also clearly described. In addition, a detailed description of numerical models used in the predictions of the two phase flow characteristics is also presented followed by addressing most of the numerical work done for predictions of CHF in literature. Due to new challenges presented by the non-uniform heating in axial and circumferential directions, research work pertaining to analysis of CHF predictions in real systems for non-uniform heating profiles in both axial and circumferential directions is also presented

  11. The "open book" flap: a heterodigital cross-finger skin flap and adipofascial flap for coverage of a circumferential soft tissue defect of a digit.

    Science.gov (United States)

    Tadiparthi, S; Akali, A; Felberg, L

    2009-02-01

    A case of circumferential digital skin loss with exposed tendons from the proximal phalanx to the distal interphalangeal joint is presented. This was treated with a two-layer heterodigital cross-finger ("open book") flap from the adjacent digit, utilising a skin-only cross-finger flap to cover the palmar defect and an adipofascial flap to cover the dorsal defect. PMID:19129359

  12. Leakage Failure Reason Analysis of Circumferential Weld for Natural Gas Pipeline%天然气输送管道环焊缝泄漏失效分析

    Institute of Scientific and Technical Information of China (English)

    胡美娟; 刘迎来; 朱丽霞; 齐丽华; 杨放

    2014-01-01

    通过断口形貌、金相分析以及力学性能检测等方法对某X80天然气输送管道环焊缝泄漏产生的原因进行了失效分析。分析结果表明,环焊缝焊接接头的拉伸性能符合Q/SY GJX 0110-2007《西气东输二线管道工程线路焊接技术规范》要求,但焊缝和热影响区的冲击性能均未达到焊接技术规范的要求,管道环焊缝泄漏裂纹位于环焊缝6点位置根焊区域,此位置根焊进行过内补焊作业,补焊焊缝焊趾处存在的焊接缺陷是环焊缝开裂泄漏的主要原因。%The leakage failure reason of circumferential weld for some X80 natural gas pipeline was analyzed by means of fracture morphology, microstructure observation and mechanical properties tests. The results showed that the tensile performance of welded joint for circumferential weld accord with the requirements of Q/SY GJX 0110-2007 Welding Technology Specification for the Second West-to-East Gas Pipeline Project, and the impact toughness of weld and HAZ both fail to meet the welding requirements of technical specification. The leaking crack of circumferential weld lies in the six position of root welding zone, and repair welding was implemented in the six position of root welding. The main leakage failure reason of circumferential weld was the welding defects close to the toe zone of the repair welding.

  13. Stress Intensity Factor for a Circumferential Crack in a Finite-Length Thin to Thick Walled Cylinder under an Arbitrary Biquadratic Stress Distribution on the Crack Surfaces

    OpenAIRE

    MESHII, Toshiyuki; WATANABE, Katsuhiko

    2001-01-01

    This paper presents the development of a practical method, by using prepared tabulated data, tocalculate the mode I stress intensity factor (SIF) for an inner surface circumferential crack in a finitelength cylinder. The crack surfaces are subjected to an axisymmetric stress with an arbitrary biquadraticradial distribution. The method was derived by applying the authors’ weight function for the crack. Thiswork is based on the thin shell theory and the Petroski-Achenbach method. Our method is ...

  14. The Analysis on Complications of Anterior Surgery for 28 Cases of Thoracolumbar Spine Burst Fracture%胸腰椎爆裂骨折28例前路手术并发症分析

    Institute of Scientific and Technical Information of China (English)

    张广平; 舒钧

    2011-01-01

    Objective To choose the right surgical treatment of thoracolumbar burst fracture, reduce complications and get the best spinal cord rehabiltion and spinal stability. Methods 28 cases of thoracolumbar burst fractures were selected in this study. preoperative X-ray examination, CT examination, and plain CT scanning were performed before anterior sugery for thoracolumbar spine. X-ray examination and CT examination were performed to observe the fixed and decompression effects 1, 2, 3, 6 months and 1 year after surgery.Results There was 1 case of the selected patients with retroperitoneal chylous fluid leak, 1 case of incisional hernia, and 1 case of pneumothorax. After active treatment, all patients were cured. Conclusions The incidence of complications of anterior sugery for thoracolumbar spine are related with the familiarity to the anatomy of thoracolumbar spine, the surgical operation skills, and experiences of the operators. Timely and effective symptomatic treatment can reduce the damage of complications to the patients.%目的 正确选择胸腰椎爆裂骨折手术治疗方法,减少并发症,以获得最佳脊髓神经恢复和脊柱稳定性.方法 胸腰椎爆裂骨折前路手术28例,术前X、CT摄片,部分行MRI平扫;术后分别1月、2月、6月、1 a摄片及部分CT检查,观察固定和减压效果.结果 1例出现乳糜液漏,1例切口疝,1例气胸.经过积极治疗,全部治愈.结论 胸腰段前路手术并发症的发生大多数和术者对该段解剖熟知程度、手术技巧和经验有关,而在发生时及时有效的进行对症治疗可将其危害降到最低.

  15. Avaliação da redução por ligamentotaxia nas fraturas toracolombares tipo explosão Evaluación de la reducción por ligamentotaxia en las fracturas toracolumbares tipo explosión Evaluation of the reduction by ligamentotaxis in thoracolumbar burst fractures

    Directory of Open Access Journals (Sweden)

    Márcio Beckhauser da Silva

    2010-06-01

    ía posterior permite, al realizar ligamentotaxia, la restauración de la altura del cuerpo vertebral fracturado, del alineamiento sagital de la columna y descompresión del canal espinal minimizando la comorbidad en relación a la cirugía por vía anterior y la laminectomía para descompresión del canal.OBJECTIVE: to evaluate the correction of kyphosis, of the vertebral body height and the reduction of the retropulsed fragments in the thoracolumbar burst fractures by means of ligamentotaxis. METHODS: retrospective study evaluating a total of 238 patients with thoracolumbar A3 burst fractures based on the classification by Magerl et al., of which 63 were eligible to the research. All patients had been treated with pedicular internal fixation and had previous and postoperative radiographs and computed tomographic images. RESULTS: the study evidenced an immediate postoperative correction of vertebral kyphosis in the fracture site in 87% of the cases, with correction of 51% in the vertebral body height and reduction of 40% the intra-canal retropulsed fragments. CONCLUSIONS: the use of internal fixation by anterior approach allows, through ligamentotaxis, the restoration of the height of the vertebral body fracture, of the sagittal alignment of the column and spinal canal decompression, thus minimizing the comorbidities in relation to the surgery by anterior approach and laminectomy to canal decompression.

  16. Fracture Toughness (K1C evaluation for dual phase medium carbon low alloy steels using circumferential notched tensile (CNT specimens

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2011-01-01

    Full Text Available The fracture behavior of dual phase medium carbon low alloy steels produced using two different chemical compositions (A - 0.34C, 0.75Mn, 0.12Cr, 0.13Ni steel and B - 0.3C, 0.97Mn, 0.15Cr steel was investigated using circumferential notched tensile (CNT specimens. Intercritical treatments were performed on samples with composition A by 1 austenitizing at 860 °C for 1 hour cooling in air, then treating at 770 °C for 30 minutes before oil quenching; 2 austenitizing at 860 °C for 1 hour quenching in oil, then treating at 770 °C for 30 minutes before quenching in oil; and 3 austenitizing at 860 °C for 1 hour, super-cooling to 770 °C and then quenching in oil. Samples of composition B were subjected to intercritical treatment at temperatures of 740, 760, and 780 °C for 30 minutes, followed by quenching rapidly in oil. Tensile testing was then performed on specimens without notches and the CNT specimens. It was observed that the dual phase steel produced from procedure (2 yielded a fine distribution of ferrite and martensite which gave the best combination of tensile properties and fracture toughness for composition A while the dual phase structure produced by treating at 760 °C yielded the best combination of tensile properties and fracture toughness for composition B. The fracture toughness results evaluated from the test were found to be valid (in plain strain condition and a high correlation between the fracture toughness and notch tensile strength was observed. The fracture toughness values were also found to be in close agreement with data available in literature.

  17. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    Energy Technology Data Exchange (ETDEWEB)

    Iannicelli, Elsa; Di Renzo, Sara [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ferri, Mario [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Pilozzi, Emanuela [Department of Clinical and Molecular Sciences, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Di Girolamo, Marco; Sapori, Alessandra [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Ziparo, Vincenzo [Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); David, Vincenzo [Radiology Institute, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy); Department of Surgical and Medical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome, Sapienza, Sant' Andrea Hospital, Rome 00189 (Italy)

    2014-07-01

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting.

  18. Sparing Sphincters and Laparoscopic Resection Improve Survival by Optimizing the Circumferential Resection Margin in Rectal Cancer Patients.

    Science.gov (United States)

    Keskin, Metin; Bayraktar, Adem; Sivirikoz, Emre; Yegen, Gülcin; Karip, Bora; Saglam, Esra; Bulut, Mehmet Türker; Balik, Emre

    2016-02-01

    The goal of rectal cancer treatment is to minimize the local recurrence rate and extend the disease-free survival period and survival. For this aim, obtainment of negative circumferential radial margin (CRM) plays an important role. This study evaluated predictive factors for positive CRM status and its effect on patient survival in mid- and distal rectal tumors.Patients who underwent curative resection for rectal cancer were included. The main factors were demographic data, tumor location, surgical technique, neoadjuvant therapy, tumor diameter, tumor depth, lymph node metastasis, mesorectal integrity, CRM, the rate of local recurrence, distant metastasis, and overall and disease-free survival. Statistical analyses were performed by using the Chi-squared test, Fisher exact test, Student t test, Mann-Whitney U test and the Mantel-Cox log-rank sum test.A total of 420 patients were included, 232 (55%) of whom were male. We observed no significant differences in patient characteristics or surgical treatment between the patients who had positive CRM and who had negative CRM, but a higher positive CRM rate was observed in patients undergone abdominoperineal resection (APR) (P CRM status. Logistic regression analysis revealed that APR (P CRM status. Moreover, positive CRM was associated with decreased 5-year overall and disease-free survival (P = 0.002 and P = 0.004, respectively).This large single-institution series demonstrated that APR and open resection were independent predictive factors for positive CRM status in rectal cancer. Positive CRM independently decreased the 5-year overall and disease-free survival rates. PMID:26844498

  19. Crack-tip constraint analyses and constraint-dependent LBB curves for circumferential through-wall cracked pipes

    International Nuclear Information System (INIS)

    Highlights: • Solution of constraint parameter τ* for through-wall cracked pipes has been obtained. • Constraint increases with increasing crack length and radius–thickness ratio of pipes. • Constraint-dependent LBB curve for through-wall cracked pipes has been constructed. • For increasing accuracy of LBB assessments, constraint effect should be considered. - Abstract: The leak-before-break (LBB) concept has been widely applied in the structural integrity assessments of pressured pipes in nuclear power plants. However, the crack-tip constraint effects in LBB analyses and designs cannot be incorporated. In this paper, by using three-dimensional finite element calculations, the modified load-independent T-stress constraint parameter τ* for circumferential through-wall cracked pipes with different geometries and crack sizes has been analyzed under different loading conditions, and the solutions of the crack-tip constraint parameter τ* have been obtained. Based on the τ* solutions and constraint-dependent J–R curves of a steel, the constraint-dependent LBB (leak-before-break) curves have been constructed. The results show that the constraint τ* increases with increasing crack length θ, mean radius Rm and radius–thickness ratio Rm/t of the pipes. In LBB analyses, the critical crack length calculated by the J–R curve of the standard high constraint specimen for pipes with shorter cracks is over-conservative, and the degree of conservatism increases with decreasing crack length θ, Rm and Rm/t. Therefore, the constraint-dependent LBB curves should be constructed to modify the over-conservatism and increase accuracy of LBB assessments

  20. Accuracy of High-Resolution MRI with Lumen Distention in Rectal Cancer Staging and Circumferential Margin Involvement Prediction

    International Nuclear Information System (INIS)

    To evaluate the accuracy of magnetic resonance imaging (MRI) with lumen distention for rectal cancer staging and circumferential resection margin (CRM) involvement prediction. Seventy-three patients with primary rectal cancer underwent high-resolution MRI with a phased-array coil performed using 60-80 mL room air rectal distention, 1-3 weeks before surgery. MRI results were compared to postoperative histopathological findings. The overall MRI T staging accuracy was calculated. CRM involvement prediction and the N staging, the accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were assessed for each T stage. The agreement between MRI and histological results was assessed using weighted-kappa statistics. The overall MRI accuracy for T staging was 93.6% (k = 0.85). The accuracy, sensitivity, specificity, PPV and NPV for each T stage were as follows: 91.8%, 86.2%, 95.5%, 92.6% and 91.3% for the group ≤ T2; 90.4%, 94.6%, 86.1%, 87.5% and 94% for T3; 98,6%, 85.7%, 100%, 100% and 98.5% for T4, respectively. The predictive CRM accuracy was 94.5% (k = 0.86); the sensitivity, specificity, PPV and NPV were 89.5%, 96.3%, 89.5%, and 96.3% respectively. The N staging accuracy was 68.49% (k = 0.4). MRI performed with rectal lumen distention has proved to be an effective technique both for rectal cancer staging and involved CRM predicting

  1. Circumferential creep properties of stress-relieved Zircaloy-4 and Zr-Nb-Sn-Fe cladding tubes

    International Nuclear Information System (INIS)

    In this study, the circumferential creep behaviors of stress-relieved Zircaloy-4 and Zr-Nb-Sn-Fe alloys were investigated. The out-of reactor creep resistance of Zircaloy-4 was found to be better than that of the Zr-Nb-Sn-Fe alloy in the temperature and stress range of this study, suggesting that the solution strengthening effect of Sn is more effective in restraining dislocation motion than the precipitate strengthening effect of Nb. Zircaloy-4 and Zr-Nb-Sn-Fe have stress exponents between 6.5 and 7.5 in the lower stress region. The stress exponent decreased to about 3 for Zircaloy-4 and to about 4.2 for Zr-Nb-Sn-Fe in the high stress region. The activation energy increased from 240 to 270 kJ/mol for Zircaloy-4 and Zr-Nb-Sn-Fe as the applied stress increased from 80 to 150 MPa. The creep activation energy observed in this study is close to those of creep for Zircaloy-2 and Zr. The lower stress exponent in the higher stress region for Zircaloy-4 with a relatively higher Sn content compared to Zr-Nb-Sn-Fe alloy may be supported by the fact that the drag force of Sn atoms acting on dislocations increases with increase of Sn content. Larson-Miller Parameter (LMP) decreased with the increase of applied stress, and Zircaloy-4 has a higher LMP than the Zr-Nb-Sn-Fe alloy, compatible with the lower creep rate in Zircaloy-4.

  2. Corrective Jaw Surgery

    Medline Plus

    Full Text Available ... Jaw Surgery Download Download the ebook for further information Corrective jaw, or orthognathic, surgery is performed by ... your treatment. Correction of Common Dentofacial Deformities ​ ​ The information provided here is not intended as a substitute ...

  3. NWS Corrections to Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Form B-14 is the National Weather Service form entitled 'Notice of Corrections to Weather Records.' The forms are used to make corrections to observations on forms...

  4. Error Correction in Classroom

    Institute of Scientific and Technical Information of China (English)

    Dr. Grace Zhang

    2000-01-01

    Error correction is an important issue in foreign language acquisition. This paper investigates how students feel about the way in which error correction should take place in a Chinese-as-a foreign-language classroom, based on empirical data of a large scale. The study shows that there is a general consensus that error correction is necessary. In terms of correction strategy, the students preferred a combination of direct and indirect corrections, or a direct only correction. The former choice indicates that students would be happy to take either so long as the correction gets done.Most students didn't mind peer correcting provided it is conducted in a constructive way. More than halfofthe students would feel uncomfortable ifthe same error they make in class is corrected consecutively more than three times. Taking these findings into consideration, we may want to cncourage peer correcting, use a combination of correction strategies (direct only if suitable) and do it in a non-threatening and sensitive way. It is hoped that this study would contribute to the effectiveness of error correction in a Chinese language classroom and it may also have a wider implication on other languages.

  5. Curative Effect Analysis of Treating Thoracolumbar Vertebral Compression Fracture Through Injured Vertebra Nail%经伤椎置钉治疗胸腰椎压缩性骨折的疗效分析

    Institute of Scientific and Technical Information of China (English)

    时代; 顾德毅; 荆鑫

    2014-01-01

    目的:探究经伤椎椎弓根复位固定的对于治疗胸腰椎骨折的可行性及其临床疗效。方法根据随机数字表法将60例单椎体胸腰椎骨折患者分为30例的经伤椎椎弓根固定的6钉固定术(6钉组)和30例的单纯行跨伤椎的4钉固定术(4钉组),对所有的患者随访12~43个月,平均随访(27.65±2.42)个月,通过比较两组的手术时间、术中出血量、术后卧床时间、术后伤口引流量等从而得到围手术期指标及伤椎前后缘高度比值内固定失败率腰背痛评分改善指数及神经功能恢复情况。结果两组围手术期相关指标中术中出血量、手术时间、术后卧床时间比较,差异有统计学意义(P<0.05),4钉组过度撑开致术后螺钉松动率为13.33%,后凸加重发生率为10.00%,这是4钉组的情况,但是6钉组则不存在此情况。4钉组术后1周和术后6个月随访腰背痛评分平均改善率均低于6钉组,差异有统计学意义,但两组术后神经功能恢复情况具有较大的差异无统计学意义。结论经伤椎椎弓根置钉能更直接牢固骨折和固定复位,改善应力分布和固定的强度,比传统跨伤椎固定能更好的维持矫正效果。%Objective The feasibility and clinical curative effect of treating thoracolumbar vertebral fracture through resetting and fixing of injured vertebral pedicle are discussed in the thesis. Methods 60 patients with single-vertebral thoracolumbar fracture are divided into two groups according to the random number table method;the first group has 30 patients who are subjected to 6-nail fixation of injured vertebral pedicle fixation (6-nail group);the second group has 30 patients who are subjected to 4-nail fixa-tion of simple line-cross injured vertebra (4-nail group). The follow-up visit time of all patients is 12 to 43 months; the average time is (27.65±2.42) months. Perioperative indicators such as operation time, the amount of intraoperative blood loss

  6. Fijación posterior monosegmentaria en fracturas de la columna toracolumbar Fixação posterior monossegmentar nas fraturas da coluna toracolombar Posterior monosegmental fixation in thoracolumbar spine fractures

    Directory of Open Access Journals (Sweden)

    José Fleiderman Valenzuela

    2011-01-01

    return to work. RESULTS: 4 patients (14% presented radiological treatment failure. 3 suffered acute complications, and had 2 delayed complications. 92.8% of the patients returned to their jobs, with a mean postoperative time out of work of 3.4 months. no statistically significant differences were detected among the different evaluated variables evaluated and the levels of treatment failure. CONCLUSION: Posterior monosegmental fixation has good results in the treatment of thoracolumbar fractures. In our series we had good clinical results in 93% and radiological results in 86% of the patients. We did not find any variable that could be correlated with treatment failure, although the cases considered failures according to the radiological exams had a major preoperative kyphosis and a greater postoperative kyphosis correction than those who did not.

  7. The May 2005 eruption of Fernandina volcano, Galápagos: The first circumferential dike intrusion observed by GPS and InSAR

    KAUST Repository

    Chadwick, William W Jr

    2010-12-15

    The May 2005 eruption of Fernandina volcano, Galápagos, occurred along circumferential fissures parallel to the caldera rim and fed lava flows down the steep southwestern slope of the volcano for several weeks. This was the first circumferential dike intrusion ever observed by both InSAR and GPS measurements and thus provides an opportunity to determine the subsurface geometry of these enigmatic structures that are common on Galápagos volcanoes but are rare elsewhere. Pre- and post- eruption ground deformation between 2002 and 2006 can be modeled by the inflation of two separate magma reservoirs beneath the caldera: a shallow sill at ~1 km depth and a deeper point-source at ~5 km depth, and we infer that this system also existed at the time of the 2005 eruption. The co-eruption deformation is dominated by uplift near the 2005 eruptive fissures, superimposed on a broad subsidence centered on the caldera. Modeling of the co-eruption deformation was performed by including various combinations of planar dislocations to simulate the 2005 circumferential dike intrusion. We found that a single planar dike could not match both the InSAR and GPS data. Our best-fit model includes three planar dikes connected along hinge lines to simulate a curved concave shell that is steeply dipping (~45-60°) toward the caldera at the surface and more gently dipping (~12-14°) at depth where it connects to the horizontal sub-caldera sill. The shallow sill is underlain by the deep point source. The geometry of this modeled magmatic system is consistent with the petrology of Fernandina lavas, which suggest that circumferential eruptions tap the shallowest parts of the system, whereas radial eruptions are fed from deeper levels. The recent history of eruptions at Fernandina is also consistent with the idea that circumferential and radial intrusions are sometimes in a stress-feedback relationship and alternate in time with one another. © 2010 Springer-Verlag.

  8. Diophantine Correct Open Induction

    CERN Document Server

    Raffer, Sidney

    2010-01-01

    We give an induction-free axiom system for diophantine correct open induction. We relate the problem of whether a finitely generated ring of Puiseux polynomials is diophantine correct to a problem about the value-distribution of a tuple of semialgebraic functions with integer arguments. We use this result, and a theorem of Bergelson and Leibman on generalized polynomials, to identify a class of diophantine correct subrings of the field of descending Puiseux series with real coefficients.

  9. Magnetic resonance-derived circumferential strain provides a superior and incremental assessment of improvement in contractile function in patients early after ST-segment elevation myocardial infarction

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Dennis T.L.; Psaltis, Peter J. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); South Australian Health and Medical Research Institute (SAHMRI), Adelaide (Australia); Monash Cardiovascular Research Centre, Department of Medicine (Monash Medical Centre)Monash University and Monash Heart, Clayton, VIC (Australia); Leong, Darryl P.; Weightman, Michael J.; Richardson, James D.; Worthley, Matthew I.; Worthley, Stephen G. [University of Adelaide, Discipline of Medicine, Adelaide (Australia); Dundon, Benjamin K.; Leung, Michael C.H.; Meredith, Ian T. [Monash Cardiovascular Research Centre, Department of Medicine (Monash Medical Centre)Monash University and Monash Heart, Clayton, VIC (Australia)

    2014-06-15

    We evaluate whether circumferential strain derived from grid-tagged CMR is a better method for assessing improvement in segmental contractile function after STEMI compared to late gadolinium enhancement (LGE). STEMI patients post primary PCI underwent baseline CMR (day 3) and follow-up (day 90). Cine, grid-tagged and LGE images were acquired. Baseline LGE infarct hyperenhancement was categorised as ≤25 %, 26-50 %, 51-75 % and >75 % hyperenhancement. The segmental baseline circumferential strain (CS) and circumferential strain rate (CSR) were calculated from grid-tagged images. Segments demonstrating an improvement in wall motion of ≥1 grade compared to baseline were regarded as having improved segmental contractile-function. Forty-five patients (aged 58 ± 12 years) and 179 infarct segments were analysed. A baseline CS cutoff of -5 % had sensitivity of 89 % and specificity of 70 % for detection of improvement in segmental-contractile-function. On receiver-operating characteristic analysis for predicting improvement in contractile function, AUC for baseline CS (0.82) compared favourably to LGE hyperenhancement (0.68), MVO (0.67) and baseline-CSR (0.74). On comparison of AUCs, baseline CS was superior to LGE hyperenhancement and MVO in predicting improvement in contractile function (P < 0.001). On multivariate-analysis, baseline CS was the independent predictor of improvement in segmental contractile function (P < 0.001). Grid-tagged CMR-derived baseline CS is a superior predictor of improvement in segmental contractile function, providing incremental value when added to LGE hyperenhancement and MVO following STEMI. (orig.)

  10. 铝合金桁架环缝自动焊机的研制%Design and manufacture of automatic circumferential welding equipment for aluminium alloy boom

    Institute of Scientific and Technical Information of China (English)

    田松亚; 封艳

    2012-01-01

    根据铝合金桁架铝合金管材与接头环缝焊接要求,设计并制造了一台专用焊接设备.根据焊接时序要求,采用可编程控制器实现对焊接设备逻辑顺序的控制,并制定了铝合金桁架铝合金管材与接头环缝的惰性气体保护焊MIG自动焊接工艺.结果表明,该焊机自动化程度高、性能稳定、操作简便,能够满足铝桁架铝合金管材与接头环缝自动焊生产要求,同时提高了生产率.依据制定的焊接工艺,进行了焊接试验.焊接试验表明,制定的工艺所获得的铝合金桁架铝合全管材与接头对接接头,满足焊缝质量要求.%According to the requirements of aluminium alloy boom circumferential welding,this paper design and manufacture a special automatic welding equipment.In terms of weld time sequence requirement,PLC is used to implement the control of welding device logical subsequence.besides.work out the MIG automatic welding procedure of circumferential welding.The Result shows that the welding device displays high degree of automation,stable performance and convenient movement,which could satisfy production requirements of aluminium alloy boom automatic circumferential welding and improve productivity .Based on the welding procedure, welding experiment is done.The result indicates that welding procedure could reach the quality requirements of welding joint.

  11. MRI interrReader and intra-reader reliabilities for assessing injury morphology and posterior ligamentous complex integrity of the spine according to the thoracolumbar injury classification system and severity score

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Guen Young; Lee, Joon Woo; Choi, Seung Woo; Lim, Hyun Jin; Sun, Hye Young; Kang, Yu Suhn; Kang, Heung Sik [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Chai, Jee Won; Kim, Su Jin [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of)

    2015-08-15

    To evaluate spine magnetic resonance imaging (MRI) inter-reader and intra-reader reliabilities using the thoracolumbar injury classification system and severity score (TLICS) and to analyze the effects of reader experience on reliability and the possible reasons for discordant interpretations. Six radiologists (two senior, two junior radiologists, and two residents) independently scored 100 MRI examinations of thoracolumbar spine injuries to assess injury morphology and posterior ligamentous complex (PLC) integrity according to the TLICS. Inter-reader and intra-reader agreements were determined and analyzed according to the number of years of radiologist experience. Inter-reader agreement between the six readers was moderate (k = 0.538 for the first and 0.537 for the second review) for injury morphology and fair to moderate (k = 0.440 for the first and 0.389 for the second review) for PLC integrity. No significant difference in inter-reader agreement was observed according to the number of years of radiologist experience. Intra-reader agreements showed a wide range (k = 0.538-0.822 for injury morphology and 0.423-0.616 for PLC integrity). Agreement was achieved in 44 for the first and 45 for the second review about injury morphology, as well as in 41 for the first and 38 for the second review of PLC integrity. A positive correlation was detected between injury morphology score and PLC integrity. The reliability of MRI for assessing thoracolumbar spinal injuries according to the TLICS was moderate for injury morphology and fair to moderate for PLC integrity, which may not be influenced by radiologist' experience.

  12. Mis-Match Limit Load Analyses and Fracture Mechanics Assessment for Welded Pipe with Circumferential Crack at the Center of Weldment

    International Nuclear Information System (INIS)

    In this paper, limit load analyses and fracture mechanics analyses were conducted via finite element analyses for the welded pipe with circumferential crack at the center of the weldment. Systematic changes for strength mismatch ratio, width of weldment, crack shape and thickness ratio of the pipe were considered to provide strength mismatch limit load. And J-integral calculations based on reference stress method were conducted for two materials, stainless steel and ferritic steel. Reference stress defined by provided strength mis-match limit load gives much more accurate J-integral

  13. The effect of deformation on unloading compliance values of TPB specimens and throughwall circumferentially cracked straight pipes under four point bending load

    International Nuclear Information System (INIS)

    Compliance technique is one of the convenient methods to measure crack growth during fracture experiments. One correlation expressing crack size as a function of unloading compliance is the prerequisite of this technique. Conventionally, compliance correlation is derived by generating compliance VI crack length data by performing small displacement linear elastic finite element analysis. However, it does not account for the large geometric deformation that may take place during the loading of the specimen. The unloading compliance may be influenced by the increasing stiffness of the specimen because of change In basic geometry. It is, therefore, of interest to study the effect of deformation on the unloading compliance. In the present work, elastic-plastic finite element analysis is carried out on three point bend (TPB) specimens and throughwall circumferentially cracked pipes under four point bending load. In case of TPB specimens, unloading compliance correlation is available. However, this correlation does not consider the effect of deformation on the compliance. The objective of this study is, therefore to investigate whether deformation of the TPB specimen changes the unloading compliances or not and whether this change, if any, warrants any modifications in the existing compliance correlation. In case of throughwall circumferentially cracked straight pipe under four point bending load which is a common component for fracture studies, no such compliance correlation is available. Because of ovalisation of pipe cross section during deformation, compliance not only depends on current crack length, but also on current load. In the present work, elastic-plastic finite element analysis has been carried out on pipes having various diameter, thickness and circumferential throughwall crack sizes. The objective is to study how initial elastic compliance of pipe is affected by deformation of the original circular cross section. From the foregoing analyses, two

  14. Braden评分法在预防胸腰椎骨折并发压疮患者中的应用%Application of Braden scoring method in the prevention of bedsore in the patients with thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    张敏

    2012-01-01

    Objective: To explore the effect of nursing intervention in the light of Braden scoring method in the prevention of bedsore in patients with thoracolumbar fractures . Methods: 138 patients with thoracolumbar fractures were randomly divided into a control group ( n= 65) and an experimental group (n =73) in order of admission. The conventional grading nursing method was implemented in the control group and Braden scoring method was used to predict the potential risk of bedsore in the patients with thoracolumbar fractures in the exper -imental group, and then the grading nursing care was given to the patients according to the scores of potential risk . Results: Bedsore occurred in one patient in the experimental group and 6 patients in the control group ,the difference was statistically significant between the two groups (P <0.05). Conclusion:The early warning nursing intervention by following Braden scoring method can effectively reduce the incidence of bedsore in the patients with thoracolumbar fractures .%目的:探讨Braden评分法护理干预对预防胸腰椎骨折患者压疮发生的疗效.方法:将138例胸腰椎骨折患者按入院先后顺序随机分为对照组65例和实验组73例,对照组采用传统分级护理方法护理,实验组应用Braden评分法预测胸腰椎骨折卧床患者压疮发生的潜在危险度,根据分值进行分级护理.结果:实验组发生压疮1例,对照组发生压疮6例,两组比较差异有统计学意义(P<0.05).结论:采用Braden评分法预警干预护理能有效降低胸腰椎骨折卧床患者压疮的发生率.

  15. Spelling Correction in Context

    OpenAIRE

    Pinot, Guillaume; Enguehard, Chantal

    2005-01-01

    International audience Spelling checkers, frequently used nowadays, do not allow to correct real-word errors. Thus, the erroneous replacement of dessert by desert is not detected. We propose in this article an algorithm based on the examination of the context of words to correct this kind of spelling errors. This algorithm uses a training on a raw corpus.

  16. Derivative corrections from noncommutativity

    International Nuclear Information System (INIS)

    We show that an infinite subset of the higher-derivative α' corrections to the DBI and Chern-Simons actions of ordinary commutative open-string theory can be determined using noncommutativity. Our predictions are compared to some lowest order α' corrections that have been computed explicitly by Wyllard (hep-th/0008125), and shown to agree. (author)

  17. Bone Cement Augmentation of Pedicle Screw Fixation Combined with Kyphoplasty for Osteoporotic Thoracolumbar Burst Fractures%骨水泥强化椎弓根螺钉固定结合椎体后凸成形术治疗骨质疏松性胸腰段爆裂骨折

    Institute of Scientific and Technical Information of China (English)

    于亮; 蒋伟宇; 赵刘军; 马维虎; 徐荣明

    2014-01-01

    (16.7±3.2)%, respectively, after 1-year fol ow-up, front and back edges of vertebral compression rates were (9.1 ±1.3)%and (1.2± 0.9)%, the correction of Cobb’s angle from (25.7±4.5)° to (3.3±2.1)°, the average correction angle was 19.8°; and VAS score decreased from (7.2±0.5) to (1.9 ±0.6). There were significantly statistical differences( P<0.05) in al indexes between pre-operation and post-operation. [Conclusion] Bone cement augmentation of pedicle screw fixation combined with kyphoplasty for osteoporotic thoracolumbar burst fractures, can effectively restore spinal sagittal alignment, maintain the height and strength for injured vertebral, avoid vertebral col apse and reduce complications.

  18. Cerebral hemodynamic difference between early- and late-onset Alzheimer's disease by circumferential profile analysis with 123I-IMP brain SPECT

    International Nuclear Information System (INIS)

    We conducted investigation to determine whether early- and late-onset Alzheimer's diseases differ pathophysiologically. Five patients with the early-onset (65 years and under) of the disease and 11 with the late-onset (65 years and over) of the disease were studied by single photon emission CT (SPECT) with N-isopropyl-p-[123I]iodoamphetamine (IMP). Circumferential profile analysis (CPA) was performed to examine differences in the predominant hypoperfusion in the temporoparietal lobe, which is considered to be functionally damaged the most in Alzheimer's disease. The Xm values, calculated from gradients between the motorsensory or occipital cortices and temporoparietal cortex in the circumferential profile curve, were compared in both groups. The Xm values for patients with early- and late-onset Alzheimer's disease were 6.81±2.10 (counts/degree) and 3.28±1.58, respectively, the difference being significant. Our results suggest that functional abnormalities in the temporoparietal area severer in early- than late-onset Alzheimer's disease and that the application of CPA to IMP SPECT is useful to elucidate the pathophysiological difference between each of the disease. (author)

  19. Assessment of Myocardial Contractile Function Using Global and Segmental Circumferential Strain following Intracoronary Stem Cell Infusion after Myocardial Infarction: MRI Feature Tracking Feasibility Study

    International Nuclear Information System (INIS)

    Background. Magnetic resonance imaging (MRI) strain analysis is a sensitive method to assess myocardial function. Our objective was to define the feasibility of MRI circumferential strain (εcc) analysis in assessing subtle changes in myocardial function following stem cell therapy. Methods and Results. Patients in the Amorcyte Phase I trial were randomly assigned to treatment with either autologous bone-marrow-derived stem cells infused into the infarct-related artery 5 to 11 days following primary PCI or control. MRI studies were obtained at baseline, 3, and 6 months. εcc was measured in the short axis views at the base, mid and apical slices of the left ventricle (LV) for each patient (13 treatments and 10 controls). Mid-anterior LV εcc improved between baseline −18.5 ± 8.6 and 3 months −22.6 ± 7.0, P = 0.03. There were no significant changes in εcc at 3 months and 6 months compared to baseline for other segments. There was excellent intraobserver and interobserver agreement for basal and mid circumferential strain. Conclusion. MRI segmental strain analysis is feasible in assessment of regional myocardial function following cell therapy with excellent intra- and inter-observer variability's. Using this method, a modest interval change in segmental εcc was detected in treatment group

  20. A comparative study of spinal bone SPECT versus X-ray radiograph, CT or MRI in patients with an acute compression fracture of a thoracolumbar vertebral body

    International Nuclear Information System (INIS)

    We retrospectively studied the spinal bone single photon emission computed tomography (SPECT) images of 84 consecutive patients (27 men, 57 women mean age, 71.3 years age range, 52-89 years) with acute non-traumatic collapse of a vertebra in the thoracolumbar spine. Of the 84 patients, 59 (70.2%) had a history of malignancy. Twelve patients (14.3%) had a vertebral metastasis and 72 (85.7%) had an osteoporosis in the vertebra. There were no clear differences between the vertebral body uptake patterns in the group with metastasis and the group with osteoporosis alone, although a horseshoe pattern tended to occur in the patients with a osteoporotic lesion (25% vs. 42%). Increased pedicle uptake was seen in 20 patients (23.8%, 20/84), 9 of whom (75.0%, 9/12) had a vertebral metastasis and 11 (15.3%, 11/72) did not (p<0.001). A pedicle sign or invasion on radiographs and/or CT images was seen in all 9 patients with metastatic disease patients (100%) but not in any of the 11 patients with osteoporosis. When pedicle uptake on SPECT images and the pedicle sign or invasion were used to diagnose bone metastasis in these 84 patients, sensitivity, specificity city, positive predictive value, negative predictive value were 75.0% (9/12), 84.7% (61/72), 45.0% (9/20), and 95.3% (61/64), respectively. Radiograph and CT remain to be important studies to diagnosis acute non-traumatic collapse of a vertebra, although a spinal SPECT study provides some additional information. (author)

  1. Comparing Single Versus Double Screw-Rod Anterior Instrumentation for Treating Thoracolumbar Burst Fractures with Incomplete Neurological Deficit: A Prospective, Randomized Controlled Trial.

    Science.gov (United States)

    Yu, Yu; Wang, Juan; Shao, Gaohai; Wang, Qunbo; Li, Bo

    2016-01-01

    BACKGROUND Following a thoracolumbar burst fracture (TCBF), anterior screw-rods apply pressure upon the graft site. However, there is limited evidence comparing single screw-rod anterior instrumentation (SSRAI) to double screw-rod anterior instrumentation (DSRAI) for TCBFs. Our objective was to compare SSRAI versus DSRAI for TCBFs with incomplete neurological deficit. MATERIAL AND METHODS A total of 51 participants with T11-L2 TCBFs (AO classification: A3) were randomly assigned to receive SSRAI or DSRAI. Key preoperative, perioperative, and postoperative data were collected. Statistical analysis was conducted to determine the independent factors associated with inferior clinical outcomes, as well as the comparative efficacy of SSRAI and DSRAI. RESULTS There were no significant differences in the key demographic and clinical characteristics between the two groups (all p>0.05). Smoking status was significantly associated with inferior three-month and six-month Denis pain scores (Wald statistic=4.246, p=0.039). Both SSRAI and DSRAI were significantly effective in improving three-month and six-month postoperative degree of kyphosis, three-month and six-month postoperative ASIA impairment scale scores, three-month and six-month postoperative Denis pain score, and three-month and six-month postoperative Denis work score (all p0.05), DSRAI displayed significantly longer operating times, as well as significantly larger operative blood losses (both p<0.001). CONCLUSIONS SSRAI may be preferable over DSRAI for TCBFs with incomplete neurological deficit due to its lower operating time and amount of operative blood loss. PMID:27197020

  2. 胸腰椎单纯性屈曲性压缩性骨折的护理%explore the treatment and care of thoracolumbar vertebral fracture

    Institute of Scientific and Technical Information of China (English)

    陈帆; 魏清; 蒋礼

    2013-01-01

    Objective:To explore the treatment and care of thoracolumbar vertebral fracture, body movement and the complications of the lower. Methods: A retrospective analysis was made on the clinical data of 47 cases of compression fractures of thoracic and lumbar spine simple sex from October, 1996 to August, 2012 in our hospital. Results: Through the careful treatment, decubitus care and prevention and treatment of complications, 47 patients of this group all got better;through the follow-up visits from half a year to 16 years, 47 patients of this group all recovered. Conclusion:Through the close observation of vital signs, limb function exercise and lumbar muscle exercise, 47 patients of this group have smoothly recovered.%  目的:探讨胸腰椎骨折治疗和护理,肢体运动,降低并发症。方法:回顾分析我院1996年10月~2012年8月47例胸腰椎单纯性屈曲性压缩性骨折的临床资料。结果:本组47例病经精心治疗、及卧姿护理,防治并发症均好转,经随访半年~16年47例均痊愈。结论:经密切观察生命体征,肢体功能运动及腰椎肌锻炼,均能顺利康复。

  3. Surgical Treatment for Congenital Kyphosis Correction Using Both Spinal Navigation and a 3-dimensional Model

    Directory of Open Access Journals (Sweden)

    Sugimoto,Yoshihisa

    2012-12-01

    Full Text Available An 11 year-old girl had 66 degrees of kyphosis in the thoracolumbar junction. For the purpose of planning for kyphosis correction, we created a 3-D, full-scale model of the spine and consulted spinal navigation. Three-dimensional models are generally used as tactile guides to verify the surgical approach and portray the anatomic relations specific to a given patient. We performed posterior fusion from Th10 to L3, and vertebral column resection of Th12 and L1. Screw entry points, directions, lengths and diameters were determined by reference to navigation. Both tools were useful in the bone resection. We could easily detect the posterior element to be resected using the 3D model. During the anterior bony resection, navigation helped us to check the disc level and anterior wall of the vertebrae, which were otherwise difficult to detect due to their depth in the surgical field. Thus, the combination of navigation and 3D models helped us to safely perform surgery for a patient with complex spinal deformity.

  4. Corrected Age for Preemies

    Science.gov (United States)

    ... Prenatal Baby Bathing & Skin Care Breastfeeding Crying & Colic Diapers & Clothing Feeding & Nutrition Preemie Sleep Teething & Tooth Care Toddler Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Baby > Preemie > Corrected Age ...

  5. Attitudinally correct nomenclature

    OpenAIRE

    Cook, A C; Anderson, R. H.

    2002-01-01

    For half a century, inappropriate terms have been used to describe the various parts of the heart in a clinical context. Does the cardiological community have the fortitude to correct these mistakes?.

  6. Nested Quantum Annealing Correction

    OpenAIRE

    Vinci, Walter; Albash, Tameem; Lidar, Daniel A.

    2015-01-01

    We present a general error-correcting scheme for quantum annealing that allows for the encoding of a logical qubit into an arbitrarily large number of physical qubits. Given any Ising model optimization problem, the encoding replaces each logical qubit by a complete graph of degree $C$, representing the distance of the error-correcting code. A subsequent minor-embedding step then implements the encoding on the underlying hardware graph of the quantum annealer. We demonstrate experimentally th...

  7. Biomechanical properties of monosegmental pedicle screw fixation via the fractured thoracolumbar vertebrae%经胸腰段伤椎单节段椎弓根螺钉固定后的生物力学特性

    Institute of Scientific and Technical Information of China (English)

    刘上楼; 徐军; 倪卓民; 张云庆; 周枫; 姜雪峰

    2013-01-01

    背景:临床常采用经伤椎椎弓根螺钉内固定治疗胸腰椎骨折,研究已证实经伤椎双侧椎弓根螺钉固定后脊柱稳定性加强,但也有研究认为经伤椎单节段椎弓根螺钉固定足以增加脊柱的稳定性,但此结论缺乏生物力学结果支持。  目的:观察胸腰段椎体骨折经伤椎单节段固定的相关生物力学特性。  方法:取扬州大学医学院解剖教研室提供8具中国人新鲜胸腰段标本(T11-L3),锯条横断2/3椎体,制成完整胸腰段椎体实验标本,将8具标本等分成跨伤椎固定组和单节段经伤椎固定组,分别在跨伤椎临近椎体四钉固定和临近椎体四钉固定+经伤椎单侧椎弓根固定。  结果与结论:胸腰段椎体骨折后经跨伤椎固定与经单节段伤椎固定的载荷-应变关系相差12%、载荷-位移关系相差11%、强度相差18%、轴向刚度相差11%、扭转力相差11%及拔出力相差1.8%,两组差异有显著性意义(P OBJECTIVE:To evaluate the biomechanical properties of monosegmental pedicle screws fixation via fractured vertebrae for thoracolumbar fracture. METHODS:Eight cadavers’ thoracolumbar specimens (T11-L3) were provided by the Department of Anatomy, Yangzhou University School of Medicine. Saw was used to transect 2/3 of the vertebrae in order to make complete experimental thoracolumbar specimens. Eight specimens were divided into two group;beyond-fractured vertebrae fixation group and monosegmental fixation via fracture vertebrae group. The specimens in the two groups were treated with adjacent vertebral four screw fixation beyond fractured vertebrae and adjacent vertebral four screw fixation+monosegmental pedicle screw fixation via fractured vertebrae respectively. RESULTS AND CONCLUSION:After thoracolumbar fracture, the differences between beyond fractured vertebrae fixation and monosegmental pedicle screw fixation via fractured vertebrae were as fol ows

  8. Circumferential lesion formation around the pulmonary veins in the left atrium with focused ultrasound using a 2D-array endoesophageal device: a numerical study

    Energy Technology Data Exchange (ETDEWEB)

    Pichardo, Samuel; Hynynen, Kullervo [Imaging Research-Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Room C713, Toronto, ON M4N 3M5 (Canada)

    2007-08-21

    Atrial fibrillation (AF) is the most frequently sustained cardiac arrhythmia affecting humans. The electrical isolation by ablation of the pulmonary veins (PVs) in the left atrium (LA) of the heart has been proven as an effective cure of AF. The ablation consists mainly in the formation of a localized circumferential thermal coagulation of the cardiac tissue surrounding the PVs. In the present numerical study, the feasibility of producing the required circumferential lesion with an endoesophageal ultrasound probe is investigated. The probe operates at 1 MHz and consists of a 2D array with enough elements (114 x 20) to steer the acoustic field electronically in a volume comparable to the LA. Realistic anatomical conditions of the thorax were considered from the segmentation of histological images of the thorax. The cardiac muscle and the blood-filled cavities in the heart were identified and considered in the sound propagation and thermal models. The influence of different conditions of the thermal sinking in the LA chamber was also studied. The circumferential ablation of the PVs was achieved by the sum of individual lesions induced with the proposed device. Different scenarios of lesion formation were considered where ultrasound exposures (1, 2, 5 and 10 s) were combined with maximal peak temperatures (60, 70 and 80 {sup 0}C). The results of this numerical study allowed identifying the limits and best conditions for controlled lesion formation in the LA using the proposed device. A controlled situation for the lesion formation surrounding the PVs was obtained when the targets were located within a distance from the device in the range of 26 {+-} 7 mm. When combined with a maximal temperature of 70 {sup 0}C and an exposure time between 5 and 10 s, this distance ensured preservation of the esophageal structures, controlled lesion formation and delivery of an acoustic intensity at the transducer surface that is compatible with existing materials. With a peak

  9. Different internal fixation treatment of thoracolumbar spinal tuberculosis:comparision of kyphosis Cobb angle and spinal stability%不同植入物内固定修复胸腰段脊柱结核:后凸Cobb角及脊柱稳定性比较

    Institute of Scientific and Technical Information of China (English)

    邢文华; 霍洪军; 肖宇龙; 杨学军; 赵岩; 付裕; 祝勇; 李峰; 辛大奇

    2015-01-01

    mild and moderate spinal kyphosis deformity. Surgical treatment of spinal tuberculosis has been frequently reported in recent years, the commonly used treatment includes lesion clearance, bone graft fusion and internal fixation. OBJECTIVE:To investigate the principle of choosing different internal fixation treatment for thoracolumbar spinal tuberculosis. METHODS:42 patients with thoracolumbar spinal tuberculosis were involved in this study from January 2001 to December 2011. Al patients suffered from waist and back pains, with the disease course range of 1 month to 7 years. Four cases showed neurological deficit before surgery. According to the Frankel classification, 1 case was graded as Frankel C and 3 cases as Frankel D. The preoperative average Cobb angle of kyphosis was 27° (range 12°-45°). The internal fixation approaches were chosen according to the tuberculose focus and vertebral fracture extent. Thoraco-abdominal approach for thoracolumbar spine via diaphragm with the removal of 11 rib and(or) 12 rib was performed for al patients. Among these protocols, 25 cases underwent anterior focal debridement and bone grafting. 17 cases had anterior focal debridement and posterior pedicle screw internal fixation (one-stage surgery in 7 cases and second-stage surgery in 10 cases). Al patients received anti-tuberculosis chemotherapy before and after operation. 36 cases used rib and 6 cases used iliac bone as bone graft. Al patients were fol owed up from 17 months to 9 years. The correction of spinal deformity, spinal stability and spinal functional recovery were observed. RESULTS AND CONCLUSION:30 patients were fol owed up after operations and the back pains disappeared. X-ray examination showed that, al patients were fixed wel without no loosening and rupture, and achieved bony fusion (the mean time were 5.4 months). No tuberculosis recurred. Four cases complicated with spinal cord injury were E grade according to the Frankel classification. The Cobb angle was 0-26

  10. Model Correction Factor Method

    DEFF Research Database (Denmark)

    Christensen, Claus; Randrup-Thomsen, Søren; Morsing Johannesen, Johannes

    1997-01-01

    of the model correction factor method, is that in simpler form not using gradient information on the original limit state function or only using this information once, a drastic reduction of the number of limit state evaluation is obtained together with good approximations on the reliability. Methods......The model correction factor method is proposed as an alternative to traditional polynomial based response surface techniques in structural reliability considering a computationally time consuming limit state procedure as a 'black box'. The class of polynomial functions is replaced by a limit...... statebased on an idealized mechanical model to be adapted to the original limit state by the model correction factor. Reliable approximations are obtained by iterative use of gradient information on the original limit state function analogously to previous response surface approaches. However, the strength...

  11. Is crack branching under shear loading caused by shear fracture? ——A critical review on maximum circumferential stress theory

    Institute of Scientific and Technical Information of China (English)

    孙宗颀

    2001-01-01

    When a crack is subjected to shear force, crack branching usually occurs. Theoretical study shows that the crack branching under shear loading is caused by tensile stress, but not caused by shear fracture. The co-plane shear fracture could be obtained if compressive stress with given direction is applied to the specimen, subsequently, calculated shear fracture toughness, KⅡ C, is larger than KⅠ C. A prerequisite of possible occurrence of mode Ⅱ fracture was proposed. The study of shear fracture shows that the maximum circumferential stress theory considered its criterion as a parametric equation of a curve in KⅠ, KⅡ plane is incorrect; the predicted ratio KⅡ C/KⅠ C=0.866 is incorrect too.

  12. Application of fracture-proof design methods using tearing-instability theory to nuclear piping postulating circumferential through-wall cracks

    International Nuclear Information System (INIS)

    This report presents methods of applying tearing instability analysis to large circumferential through-wall cracks in piping to demonstrate cases of adequate ductility to avoid double ended break. The first part gives results of applying simplified rigid-plastic cracked section analysis to some typical piping systems and subsequently gives some additional refinements of this type of analysis. The second part presents full elastic-plastic cracked section analysis which demonstrates the adequacy of rigid-plastic analysis for most cases and provides the methodology where elastic-plastic analysis is required. The results combined with adequate treatment of material property data and other deformation limiting and load limiting aspects of as-built piping systems, provides a complete analysis of subject

  13. Bryant J. correction formula

    International Nuclear Information System (INIS)

    For the practical application of the method proposed by J. Bryant, the authors carried out a series of small corrections, related with the bottom, the dead time of the detectors and channels, with the resolution time of the coincidences, with the accidental coincidences, with the decay scheme and with the gamma efficiency of the beta detector beta and the beta efficiency beta of the gamma detector. The calculation of the correction formula is presented in the development of the present report, being presented 25 combinations of the probability of the first existent state at once of one disintegration and the second state at once of the following disintegration. (Author)

  14. A method for the measurement of dispersion curves of circumferential guided waves radiating from curved shells: experimental validation and application to a femoral neck mimicking phantom

    Science.gov (United States)

    Nauleau, Pierre; Minonzio, Jean-Gabriel; Chekroun, Mathieu; Cassereau, Didier; Laugier, Pascal; Prada, Claire; Grimal, Quentin

    2016-07-01

    Our long-term goal is to develop an ultrasonic method to characterize the thickness, stiffness and porosity of the cortical shell of the femoral neck, which could enhance hip fracture risk prediction. To this purpose, we proposed to adapt a technique based on the measurement of guided waves. We previously evidenced the feasibility of measuring circumferential guided waves in a bone-mimicking phantom of a circular cross-section of even thickness. The goal of this study is to investigate the impact of the complex geometry of the femoral neck on the measurement of guided waves. Two phantoms of an elliptical cross-section and one phantom of a realistic cross-section were investigated. A 128-element array was used to record the inter-element response matrix of these waveguides. This experiment was simulated using a custom-made hybrid code. The response matrices were analyzed using a technique based on the physics of wave propagation. This method yields portions of dispersion curves of the waveguides which were compared to reference dispersion curves. For the elliptical phantoms, three portions of dispersion curves were determined with a good agreement between experiment, simulation and theory. The method was thus validated. The characteristic dimensions of the shell were found to influence the identification of the circumferential wave signals. The method was then applied to the signals backscattered by the superior half of constant thickness of the realistic phantom. A cut-off frequency and some portions of modes were measured, with a good agreement with the theoretical curves of a plate waveguide. We also observed that the method cannot be applied directly to the signals backscattered by the lower half of varying thicknesses of the phantom. The proposed approach could then be considered to evaluate the properties of the superior part of the femoral neck, which is known to be a clinically relevant site.

  15. 环形大腿吸脂术150例体会%A clinical analysis of circumferential thigh liposuction: 150 cases report

    Institute of Scientific and Technical Information of China (English)

    黎石峰; 李俊明; 张昕霞; 江华; 李琳

    2013-01-01

    目的 探讨一种安全有效的大腿吸脂塑形的方法.方法 自2008年4月至2012年5月,采用持续硬膜外麻醉+肿胀麻醉下行360°环形吸脂术,对150例求美者大腿进行吸脂塑形.结果 本组求美者150例,术中麻醉效果好,出血少,术后随访3~9个月,吸脂塑形效果好,并发症少.结论 持续硬膜外麻醉+肿胀麻醉下行360°环形大腿吸脂术是一种安全、有效的方法,值得临床推广.%Objective To explore a safe and effective liposuction method for the thigh lipostructure.Methods From April 2008 to May 2012,circumferential bilateral thigh liposuction under continuous epidural anesthesia combined with local tumescent anesthesia was performed on 150 cases.Results Satisfactory results were received with good intraoperative anesthetic effect and less bleeding.After 3 to 9 months follow-up,satisfied thigh contour was obtained in all cases with few postoperative complications.Conclusion Circumferential thigh liposuction under continuous epidural anesthesia combined with local tumescent anesthesia is a safe and efficacy approach for thigh lipostructure.

  16. Circumferential Strain Can Be Used to Detect Lipopolysaccharide-Induced Myocardial Dysfunction and Predict the Mortality of Severe Sepsis in Mice

    Science.gov (United States)

    Chu, Ming; Gao, Yao; Zhou, Bin; Wu, Bingruo; Wang, Junhong; Xu, Di

    2016-01-01

    Background Sepsis-induced myocardial dysfunction is a common and severe complication of septic shock. However, conventional echocardiography often fails to reveal myocardial depression in severe sepsis. Recently, strain measurements based on speckle tracking echocardiography (STE) have been used to evaluate cardiac function. Aims To investigate the role of STE in detecting lipopolysaccharide (LPS)-induced cardiac dysfunction, M-mode and 2-D echocardiography were used in LPS-treated mice. Methods The mice were treated with a 10mg/kg (n = 10), 20mg/kg (n = 10) or 25mg/kg LPS (n = 30) to induce cardiac dysfunction. Subsequently, the ejection fraction (EF) and fractional shortening (FS) were measured with standard M-mode tracings, whereas the circumferential (Scirc) and radial strain (Srad) were measured with STE. Serum biochemical and cardiac histopathological examinations were performed to assess sepsis-induced myocardial injury. Results 20mg/kg LPS resulted in more deterioration, myocardial damage and cardiac contractile dysfunction based on serum biochemical and histological examinations. The mice that were subjected to 20mg/kg LPS exhibited reduced Scirc but no reduction in Srad, whereas on conventional echocardiography, the ejection fraction (EF) and fractional shortening (FS) were similar in the 10mg/kg and 20mg/kg groups. Moreover, Scirc was positively correlated with body temperature in the mice at 20 h after LPS injection (r = 0.746, p = 0.001), but no significant correlation was observed between Srad and body temperature (r = 0.356, p = 0.123). Moreover, the mice with high Scirc (-5.9% to -10.4%) exhibited reduced mortality following the administration of 25mg/kg LPS (p = 0.03) compared with the low-strain group (-2% to -5.9%). Conclusions Taken together, our findings indicate that circumferential strain is a specific and reliable indicator for evaluating LPS-induced cardiac dysfunction in mice. PMID:27177150

  17. 基于PLC的钢管环缝焊接性能研究%Performance of circumferential welding for steel tube based on PLC

    Institute of Scientific and Technical Information of China (English)

    陈怀忠; 许雪贵; 黄芳

    2014-01-01

    PLC technique was applied for controlling the CO2 gas shielded welding process of circumferential welding for 20MnCr steel tube. The corrosion resistance,thermal fatigue resistance,tensile and impact properties were tested and analyzed. The results show that compared with the common control method,the PLC control technique can obtain better corrosion resistance, thermal fatigue resistance,tensile and impact properties of welding joint. After neutral salt-spray corrosion for 240 h,the mass loss rate of circumferential welding joint by PLC technique decreases by 65%,tensile strength at 20℃increases by 15%,and impact energy at 20℃increases by 26%.%在20MnCr钢管环缝CO2气体保护焊控制过程中引入PLC技术,进行焊接接头耐腐蚀性能、抗热疲劳性能、拉伸和冲击性能的测试与对比分析。结果表明:与传统控制技术相比,采用PLC技术获得的焊接接头具有更优的耐腐蚀性能、抗热疲劳性能、拉伸和冲击性能;经过240 h中性盐雾腐蚀后质量损失率降低了65%;20℃抗拉强度增加15%、冲击吸收功增加26%。

  18. A method for the measurement of dispersion curves of circumferential guided waves radiating from curved shells: experimental validation and application to a femoral neck mimicking phantom.

    Science.gov (United States)

    Nauleau, Pierre; Minonzio, Jean-Gabriel; Chekroun, Mathieu; Cassereau, Didier; Laugier, Pascal; Prada, Claire; Grimal, Quentin

    2016-07-01

    Our long-term goal is to develop an ultrasonic method to characterize the thickness, stiffness and porosity of the cortical shell of the femoral neck, which could enhance hip fracture risk prediction. To this purpose, we proposed to adapt a technique based on the measurement of guided waves. We previously evidenced the feasibility of measuring circumferential guided waves in a bone-mimicking phantom of a circular cross-section of even thickness. The goal of this study is to investigate the impact of the complex geometry of the femoral neck on the measurement of guided waves. Two phantoms of an elliptical cross-section and one phantom of a realistic cross-section were investigated. A 128-element array was used to record the inter-element response matrix of these waveguides. This experiment was simulated using a custom-made hybrid code. The response matrices were analyzed using a technique based on the physics of wave propagation. This method yields portions of dispersion curves of the waveguides which were compared to reference dispersion curves. For the elliptical phantoms, three portions of dispersion curves were determined with a good agreement between experiment, simulation and theory. The method was thus validated. The characteristic dimensions of the shell were found to influence the identification of the circumferential wave signals. The method was then applied to the signals backscattered by the superior half of constant thickness of the realistic phantom. A cut-off frequency and some portions of modes were measured, with a good agreement with the theoretical curves of a plate waveguide. We also observed that the method cannot be applied directly to the signals backscattered by the lower half of varying thicknesses of the phantom. The proposed approach could then be considered to evaluate the properties of the superior part of the femoral neck, which is known to be a clinically relevant site. PMID:27272197

  19. Osteoporotic compression fracture of the thoracolumbar spine and sacral insufficiency fracture: incidence and analysis of the relationship according to the clinical factors

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Jeong Hwa; Park, Ji Sun; Ryu, Kyung Nam [Kyunghee University Hospital, Seoul (Korea, Republic of)

    2006-11-15

    To evaluate the incidence of sacral insufficiency fracture in osteoporotic patient with compression fracture of the thoracolumbar (T-L) spine on magnetic resonance image (MRI), and to analyze the correlation of variable clinical factors and the incidence of sacral insufficiency fracture. We retrospectively reviewed 160 patients (27 men, 133 women; age range of 50 to 89 years) who underwent spinal MRI and had compression fracture of the T-L spine. Compression fractures due to trauma or tumor were excluded. We evaluated the incidence of sacral insufficiency fracture according to the patients' age, sex, number of compression fractures, and the existence of bone marrow edema pattern of compression fracture. During the same period, we evaluated the incidence of spinal compression fracture in the patients of pelvic insufficiency fracture. Out of the 160 patients who had compression fracture in the T-L spine, 17 (10.6%) had insufficiency fracture of the sacrum. Compression fracture occurred almost 5 times more frequently in women (27:133), but the incidence of sacral insufficiency fracture was 2/27 for men (7.4%) and 15/133 for women (11.3%), with no statistically significant difference ({rho} = 0.80). According to age, the ratio of insufficiency fracture to compression fracture was 0% (0/23) in the 50's, 10.6% (7/66) in the 60's, 12.5% (7/56) in the 70's, and 20.0% (3/15) in the 80's. In respect of single and multiple compression fracture, the incidence of sacral insufficiency fracture was 8/65 for men (12.3%) and 9/95 for women (9.5%), showing no significant difference ({rho} = 0.37). In the patients with and without compression fracture with bone marrow edema, insufficiency fracture occurred in 5/76 (6.6%) and 12/84 (14.3%), respectively. On the other hand, of the 67 patients who had pelvic insufficiency fracture, 27 (40.3%) also had spinal compression fracture. About 10% of the patients with osteoporotic compression fracture in the T/L spine

  20. The Digital Correction Unit: A data correction/compaction chip

    International Nuclear Information System (INIS)

    The Digital Correction Unit (DCU) is a semi-custom CMOS integrated circuit which corrects and compacts data for the SLD experiment. It performs a piece-wise linear correction to data, and implements two separate compaction algorithms. This paper describes the basic functionality of the DCU and its correction and compaction algorithms

  1. Text Induced Spelling Correction

    NARCIS (Netherlands)

    Reynaert, M.W.C.

    2004-01-01

    We present TISC, a language-independent and context-sensitive spelling checking and correction system designed to facilitate the automatic removal of non-word spelling errors in large corpora. Its lexicon is derived from a very large corpus of raw text, without supervision, and contains word unigram

  2. Writing: Revisions and Corrections

    Science.gov (United States)

    Kohl, Herb

    1978-01-01

    A fifth grader wanted to know what he had to do to get all his ideas the way he wanted them in his story writing "and" have the spelling, punctuation and quotation marks correctly styled. His teacher encouraged him to think about writing as a process and provided the student with three steps as guidelines for effective writing. (Author/RK)

  3. Ballistic deficit correction

    International Nuclear Information System (INIS)

    The EUROGAM data-acquisition has to handle a large number of events/s. Typical in-beam experiments using heavy-ion fusion reactions assume the production of about 50 000 compound nuclei per second deexciting via particle and γ-ray emissions. The very powerful γ-ray detection of EUROGAM is expected to produce high-fold event rates as large as 104 events/s. Such high count rates introduce, in a common dead time mode, large dead times for the whole system associated with the processing of the pulse, its digitization and its readout (from the preamplifier pulse up to the readout of the information). In order to minimize the dead time the shaping time constant τ, usually about 3 μs for large volume Ge detectors has to be reduced. Smaller shaping times, however, will adversely affect the energy resolution due to ballistic deficit. One possible solution is to operate the linear amplifier, with a somewhat smaller shaping time constant (in the present case we choose τ = 1.5 μs), in combination with a ballistic deficit compensator. The ballistic deficit can be corrected in different ways using a Gated Integrator, a hardware correction or even a software correction. In this paper we present a comparative study of the software and hardware corrections as well as gated integration

  4. 经伤椎椎弓根椎体内植骨治疗胸腰椎爆裂性骨折临床观察%Clinical Observation of Blowout Fracture Within the Vertebral Pedicle Bone Graft for Thoracolumbar

    Institute of Scientific and Technical Information of China (English)

    陈煜东

    2015-01-01

    Objective To observe the pedicle bone graft for thoracolumbar burst fracture treatment. Methods 65 cases of thoracolumbar fracture patients were chosen from May 2011 to October 2012 in our hospital, they were given by pedicle bone graft treatment, surgery to vertebral CT taken as the center piece and X ray, fracture healing state, vertebral height and Cobb angle changes to improve the situation. Results The patients were followed up 0.5~3 years, the excellent was 87.69%in this group, all patients were low back pain, no fracture fixation, failure, loosening and other complications. Conclusion The administration of thoracolumbar burst fracture patients by internal pedicle bone graft treatment, helps promote healing, strengthen before vertebral column stability, reduce long-term complications.%目的:观察经伤椎椎弓根椎体内植骨对胸腰椎爆裂性骨折的治疗效果。方法选择2011年5月~2012年10月我院收治的65例胸腰椎爆裂性骨折患者,均给予经伤椎椎弓根椎体内植骨治疗,术后以伤椎为中心拍摄CT片及X线片,观察骨折愈合状态、伤椎高度变化及Cobb角改善情况。结果术后随访0.5~3年,本组优良率为87.69%,所有患者均未出现腰背疼痛,无内固定断裂、失效、松动等并发症。结论给予胸腰椎爆裂性骨折患者经伤椎椎弓根椎体内植骨治疗,有助于促进骨折愈合,加强伤椎前中柱稳定性,减少远期并发症发生。

  5. Constipation acupuncture in the treatment of thoracolumbar fractures after abdominal distension constipation curative effect observation%便秘灸治疗胸腰椎骨折后腹胀便秘的疗效观察

    Institute of Scientific and Technical Information of China (English)

    任春霞

    2016-01-01

    目的:观察便秘灸治疗胸腰椎骨折患者腹胀、便秘的疗效。方法:将102例胸腰椎骨折后腹胀便秘的患者随机分成两组,观察组用便秘灸贴敷脐部,对照组给予腹部按摩、热敷、口服缓泻剂等方法。观察两组患者肛门排气、排便、腹胀消除的情况及观察两组病人副作用发生情况。结果:观察组总有效率96.15%,对照组74%。副作用发生情况:观察组9.16%,对照组36%。结论:便秘灸治疗胸腰椎骨折患者腹胀便秘效果优于按摩、热敷、口服缓泻剂等方法。两组比较,差异有统计学意义(P<0.01)。%Objective To observe the constipation main treatment of thoracolumbar fractures in patients with abdominal distension and constipation curative effect.Methods 102 cases of thoracolumbar fractures after abdominal distension constipation patients were randomly divided into two groups, observation group with constipation main navel, the control group given abdominal massage and hot compress, oral sugar-refining, etc. Observe two groups of patients with anal exhaust, defecation, abdominal distension, eliminate.Results Observation group total effectiveness 96.15%, control group 74%.Conclusion Abdominal distension of constipation in patients with constipation acupuncture treatment thoracolumbar fractures is better than massage and hot compress, oral sugar-refining, etc. Comparison of similar between the two groups was statistically significant (P<0.01).

  6. Application of intermediate screw technology on thoracolumbar fractures%经伤椎椎弓根置钉技术在胸腰段骨折中的应用

    Institute of Scientific and Technical Information of China (English)

    吕豪珍; 林红; 张绍昆; 闫明; 刘理迪

    2012-01-01

    BACKGROUND: For thoracolumbar fractures, there are a lot of fixed ways, however, at present intermediate screws in shortsegment pedicular fixation is minimal damage, cost less, and fixed tightly.OBJECTIVE: To systemic illustrate the technology of intermediate screw and clinical application effect.METHODS: A computer-based online search was performed on PuMed database and CNKI database with key words of"Intermediate screws, pedicular screw fixation, thoracolumbar fracture" in English and Chinese from January 1983 to June 2011.Repeated literatures were eliminated.RESULTS AND CONCLUSION: A total of 48 articles were included to review. Biological mechanics experimental and clinicalapplication result indicates that intermediate screws in short segment pedicular fixation can instantly reset vertebral fracture,restore vertebral body height, and compared with the traditional short segments of the posterior fixation, intermediate screws inshort segment pedicular fixation can effectively reduce the incidence of complications of internal fixation loose or screw breakage,vertebral height lost again.%背景:对于胸腰椎骨折,有很多固定方式,但目前经伤椎后路短节段内固定是损伤最小、费用较少,且固定牢固的固定方式.目的:系统阐述伤椎置钉技术的发展及其临床应用效果.方法:应用计算机检索1983-01/2011-06 PubMed数据库、中国知网数据库中相关文章,中文检索词为"伤椎置钉,椎弓根螺钉内固定,胸腰段骨折",英文检索词为"intermediate screws,pedicular screw fixation,thoracolumbar fracture".排除重复文献.结果与结论:共纳入48篇文献进行综述.目前,生物力学实验及临床应用结果证明,经伤椎短节段椎弓根螺钉内固定能即时复位骨折椎体,恢复椎体高度,且同传统的后路短节段内固定相比,能有效地降低内固定松动或短钉、伤椎高度再次丢失等并发症的发生率.

  7. CTI Correction Code

    Science.gov (United States)

    Massey, Richard; Stoughton, Chris; Leauthaud, Alexie; Rhodes, Jason; Koekemoer, Anton; Ellis, Richard; Shaghoulian, Edgar

    2013-07-01

    Charge Transfer Inefficiency (CTI) due to radiation damage above the Earth's atmosphere creates spurious trailing in images from Charge-Coupled Device (CCD) imaging detectors. Radiation damage also creates unrelated warm pixels, which can be used to measure CTI. This code provides pixel-based correction for CTI and has proven effective in Hubble Space Telescope Advanced Camera for Surveys raw images, successfully reducing the CTI trails by a factor of ~30 everywhere in the CCD and at all flux levels. The core is written in java for speed, and a front-end user interface is provided in IDL. The code operates on raw data by returning individual electrons to pixels from which they were unintentionally dragged during readout. Correction takes about 25 minutes per ACS exposure, but is trivially parallelisable to multiple processors.

  8. Aberration Corrected Emittance Exchange

    CERN Document Server

    Nanni, Emilio A

    2015-01-01

    Full exploitation of emittance exchange (EEX) requires aberration-free performance of a complex imaging system including active radio-frequency (RF) elements which can add temporal distortions. We investigate the performance of an EEX line where the exchange occurs between two dimensions with normalized emittances which differ by orders of magnitude. The transverse emittance is exchanged into the longitudinal dimension using a double dog-leg emittance exchange setup with a 5 cell RF deflector cavity. Aberration correction is performed on the four most dominant aberrations. These include temporal aberrations that are corrected with higher order magnetic optical elements located where longitudinal and transverse emittance are coupled. We demonstrate aberration-free performance of emittances differing by 4 orders of magnitude, i.e. an initial transverse emittance of $\\epsilon_x=1$ pm-rad is exchanged with a longitudinal emittance of $\\epsilon_z=10$ nm-rad.

  9. Quantum Error Correcting Subsystems and Self-Correcting Quantum Memories

    CERN Document Server

    Bacon, D

    2005-01-01

    The most general method for encoding quantum information is not to encode the information into a subspace of a Hilbert space, but to encode information into a subsystem of a Hilbert space. In this paper we use this fact to define subsystems with quantum error correcting capabilities. In standard quantum error correcting codes, one requires the ability to apply a procedure which exactly reverses on the error correcting subspace any correctable error. In contrast, for quantum error correcting subsystems, the correction procedure need not undo the error which has occurred, but instead one must perform correction only modulo the subsystem structure. Here we present two examples of quantum error correcting subsystems. These examples are motivated by simple spatially local Hamiltonians on square and cubic lattices. In three dimensions we provide evidence, in the form a simple mean field theory, that our Hamiltonian gives rise to a system which is self-correcting. Such a system will be a natural high-temperature qua...

  10. Correction and updating.

    Science.gov (United States)

    1994-03-01

    In the heading of David Cassidy's review of The Private Lives of Albert Einstein (18 February, p. 997) the price of the book as sold by its British publisher, Faber and Faber, was given incorrectly; the correct price is pound15.99. The book is also to be published in the United States by St. Martin's Press, New York, in April, at a price of $23.95. PMID:17817438

  11. Improved Lateral Anterior Surgical Approaches in Thoracolumbar Burst Fractures%改进的侧前方手术径路在胸腰椎爆裂性骨折中的应用

    Institute of Scientific and Technical Information of China (English)

    曹众; 米光明; 熊俭

    2013-01-01

      目的针对胸腰椎爆裂性骨折行改进侧前方手术径路的治疗效果进行研讨。方法对我院在2010年3月至2011年11月所收治的36例胸腰椎爆裂性骨折患者采取随机分配的方式分为治疗组与对照组,治疗组行改进的侧前方手术径路治疗,对照组行传统的胸腹膜外入路治疗,比较两组患者术中出血量、手术时间、最终治疗效果。对患者骨折情况进行随访3~12个月。结果36例患者手术均取得成功,治疗组在手术过程中出血量、总出血量、手术时间均少于对照组,两组患者数据对比具有明显差异(P<0.05)。随访两组患者术后均未出现感染、无截瘫加重、无植骨块塌陷等情况出现。结论对胸腰椎爆裂性骨折患者行改进的侧前方手术路径治疗方法能够减少术中出血量、总出血量,减短手术时间,最大限度保证脊柱稳定性,降低脊髓损伤的发生概率,保证治疗效果,是治疗胸腰椎爆裂性骨折疗效较好的治疗方法。%Objective To discuss the surgical approach improved side in front of thoracolumbar burst fracture line treatment effect. Methods 36 cases admitted to our hospital in March 2010-November thoracolumbar burst fracture patients were randomly divided into a treatment group and the control group, the treatment of lateral anterior surgical approach in the treatment group line improvements, the control group underwent traditional film outside the thoracoabdominal approach for treatment, the two groups were compared blood loss, operative time, the final treatment effect. Results 36 patients with surgery were successful, the treatment group in the amount of bleeding during surgery, the total amount of bleeding, surgery time was less than that of the control group, the two groups of patients with the comparison of the data with a significant difference (P<0.05). None of the follow-up postoperative infection, paraplegia heavier, graft

  12. 经皮可扩张椎体支柱块置入术治疗胸腰椎压缩骨折%Percutaneous intravertebral expandable pillar implanting for treatment of thoracolumbar vertebral compression fractures

    Institute of Scientific and Technical Information of China (English)

    黄智慧; 丁亮华; 胡新宇; 包欣南; 张乃东; 凌为其

    2012-01-01

    目的 探讨经皮可扩张椎体支柱块(IVEP)置入并植骨治疗胸腰椎压缩性骨折的手术技巧和短期疗效.方法 自2009年1月~2011年2月采用经皮穿刺经双侧椎弓根IVEP置入术治疗胸腰椎压缩性骨折42例(44椎),共置入支柱块88枚.结果 术后疼痛显著缓解,VAS评分及ODI评分均较术前明显降低.平均手术时间(38.8±5.3)min/椎.术后椎体高度平均恢复至正常椎体高度的(89.6±6.5)%,术后Cobb角明显变小.至末次随访,骨折愈合良好,无复位丢失和支柱块移位.结论 经皮可扩张IVEP置入并植骨治疗胸腰椎压缩性骨折的短期疗效满意,具有创伤小、手术操作简便、并发症少、并且可保留脊柱生理活动度的优点,是治疗该类骨折较为理想的选择.%Objective To study the operation techniques and therapeutic outcomes of percutaneous intravertebral expandable pillar (IVEP) implanting for treatment of thoracolumbar vertebral compression fractures. Methods Between January 2009 and February 2012, forty-two patients with thoracolumbar vertebral compression fractures were treated by percutaneously IVEP implanting and bone grafting through bilateral pedicle. Results Forty-four vertebral bodies were treated in forty-two patients. All patients successfully underwent the surgery without open-surgery or changing internal fixation. The average operation tune was (38.8?.3)min per vertebral body (range, 25~45 min). Pain was prominently relieved the next day after operation. The VAS was (8.2?.2) before operation and (2.3?.1) twenty-four hours after operation. The ODI was (53.2?3.4)% before operation and (24.9?4.7)%. The preoperative loss of vertebral height was 36% and it was reduced to 10% postoperatively. The average Cobb's angle was 23?preoperatively and 8?postoperatively. In an average follow up of 13.7 months (range 6-20 months), there were no loss of reduction and dislocation of IVEP. Conclusion These forty-two cases demonstrate that the IVEP

  13. Fratura toracolombar explosão: confiabilidade do método de guerra na análise tomográfica Thoracolumbar burst fracture: reliability of the guerra's method on tomographic analysis

    Directory of Open Access Journals (Sweden)

    Osmar Avanzi

    2009-01-01

    Full Text Available OBJETIVOS: Avaliar as características do fragmento retropulsado nas fraturas explosão da coluna toracolombar, de acordo com dois examinadores independentes no plano sagital da TAC e correlacionar estes achados com a presença de déficit neurológico. MATERIAL E MÉTODOS: Coleta retrospectiva de dados de prontuário e TC em 138 pacientes com fratura toracolombar do tipo explosão internados no nosso serviço entre 1983 e 2004. RESULTADOS: Observamos correlação significante entre dois examinadores independentes (pOBJECTIVES: The objective of the current study was to evaluate the correlation between neurological deficits and the characteristics of retropulsed fragment into the spinal canal in patients with thoracolumbar burst fractures. MATERIAL AND METHODS: From 1983 to 2004, 135 patients with thoracolumbar burst fractures according to Denis' criteria were evaluated at a tertiary teaching institution by two different observers. CT-Scans of the fractured spine were analyzed in order to assess the narrowing of the spinal canal. Neurological deficit was evaluated by using the Franke's classification. RESULTS: A significant correlation was found between two independent observers (P<0.05. The observed characteristics of the retropulsed fragment into the spinal canal were: triangular form, rotation dislocation with average of 20 degrees and cranial dislocation with average of eight millimeters. There was no statistical correlation between neurological deficits and the characteristics of retropulsed fragment of the spinal canal. CONCLUSION: There was no statistical correlation between neurological deficits and the characteristics of retropulsed fragment of the spinal canal.

  14. 胸腰椎多节段脊柱骨折手术治疗的临床疗效分析%Analysis Clinical Curative Effect on Thoracolumbar Spinal Fracture Surgery

    Institute of Scientific and Technical Information of China (English)

    王雯筠

    2015-01-01

    Objective Analysis clinical curative effect on thoracolumbar spinal fracture surgery. Methods Adopt operation treatment for 75 cases with thoracolumbar multi segmental spinal, observation patients with fracture reduction and Frankel classification postoperative. Results All the patients were followed up, no internal fixation loosen, broken rods, screw breakage condition. Patients with vertebral height from preoperative 22.75%~75.41%to 80.54%~99.21%to postoperative recovery. Conclusion In thoracic and lumbar spine were treated with multi section treat according to the speciifc situation of patients with fracture of spinal column sequence, returned to normal, complete reconstruction of spinal stability.%目的:对胸腰椎多节段脊柱骨折手术治疗的临床疗效进行分析。方法对75例胸腰椎多节段脊柱患者对其进行手术治疗,术后观察患者骨折复位情况及Frankel分级情况。结果对患者进行随访,随访时患者均未出现内固定松动、断棒、断钉情况。患者椎体高度由术前22.75%~75.41%,恢复至术后80.54%~99.21%。结论在对胸腰椎多节段脊柱骨折患者进行治疗时应根据患者具体情况进行治疗,从而使患者脊柱序列恢复正常,完成重建脊柱稳定的目的。

  15. Circumferential or sectored beam arrangements for stereotactic body radiation therapy (SBRT) of primary lung tumors: Effect on target and normal-structure dose-volume metrics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, Mara W. [Broad Institute of MIT and Harvard, Cambridge, MA (United States); Department of Physics, Brandeis University, Waltham, MA (United States); Kato, Catherine M. [Macalester College, St. Paul, MN (United States); Carson, Kelly M.P. [The University of North Carolina, Chapel Hill, NC (United States); Matsunaga, Nathan M. [Santa Clara University, Santa Clara, CA (United States); Arao, Robert F. [Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, OR (United States); Doss, Emily J. [Department of Internal Medicine, Providence St. Vincent Medical Center, Portland, OR (United States); McCracken, Charles L. [Department of Radiation Medicine, Oregon Health and Science University, Portland, OR (United States); Meng, Lu Z. [Department of Radiation Oncology, University of California Davis Comprehensive Cancer Center, Sacramento, CA (United States); Chen, Yiyi [Department of Public Health and Preventive Medicine, Oregon Health and Science University, Portland, OR (United States); Laub, Wolfram U.; Fuss, Martin [Department of Radiation Medicine, Oregon Health and Science University, Portland, OR (United States); Department of Nuclear Engineering and Radiation Health Physics, Oregon State University, Corvallis, OR (United States); Tanyi, James A., E-mail: tanyij@ohsu.edu [Department of Radiation Medicine, Oregon Health and Science University, Portland, OR (United States); Department of Nuclear Engineering and Radiation Health Physics, Oregon State University, Corvallis, OR (United States)

    2013-01-01

    To compare 2 beam arrangements, sectored (beam entry over ipsilateral hemithorax) vs circumferential (beam entry over both ipsilateral and contralateral lungs), for static-gantry intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) delivery techniques with respect to target and organs-at-risk (OAR) dose-volume metrics, as well as treatment delivery efficiency. Data from 60 consecutive patients treated using stereotactic body radiation therapy (SBRT) for primary non–small-cell lung cancer (NSCLC) formed the basis of this study. Four treatment plans were generated per data set: IMRT/VMAT plans using sectored (-s) and circumferential (-c) configurations. The prescribed dose (PD) was 60 Gy in 5 fractions to 95% of the planning target volume (PTV) (maximum PTV dose ∼ 150% PD) for a 6-MV photon beam. Plan conformality, R{sub 50} (ratio of volume circumscribed by the 50% isodose line and the PTV), and D{sub 2} {sub cm} (D{sub max} at a distance ≥2 cm beyond the PTV) were evaluated. For lungs, mean doses (mean lung dose [MLD]) and percent V{sub 30}/V{sub 20}/V{sub 10}/V{sub 5} Gy were assessed. Spinal cord and esophagus D{sub max} and D{sub 5}/D{sub 50} were computed. Chest wall (CW) D{sub max} and absolute V{sub 30}/V{sub 20}/V{sub 10}/V{sub 5} {sub Gy} were reported. Sectored SBRT planning resulted in significant decrease in contralateral MLD and V{sub 10}/V{sub 5} {sub Gy}, as well as contralateral CW D{sub max} and V{sub 10}/V{sub 5} {sub Gy} (all p < 0.001). Nominal reductions of D{sub max} and D{sub 5}/D{sub 50} for the spinal cord with sectored planning did not reach statistical significance for static-gantry IMRT, although VMAT metrics did show a statistically significant decrease (all p < 0.001). The respective measures for esophageal doses were significantly lower with sectored planning (p < 0.001). Despite comparable dose conformality, irrespective of planning configuration, R{sub 50} significantly improved with IMRT

  16. Assessing the correctional orientation of corrections officers in South Korea.

    Science.gov (United States)

    Moon, Byongook; Maxwell, Sheila Royo

    2004-12-01

    The correctional goal in South Korea has recently changed from the straightforward punishment of inmates to rehabilitation. Currently, emphases are being placed on education, counseling, and other treatment programs. These changes have consequently begun to also change the corrections officers' roles from a purely custodial role to a human service role, in which officers are expected to manage rehabilitation and treatment programs. Despite these changes, few studies have examined the attitudes of corrections officers toward rehabilitation programming. This is an important dimension to examine in rehabilitation programming, as corrections officers play a major role in the delivery of institutional programs. This study examines the attitudes of South Korean corrections officers toward rehabilitation programs. Approximately 430 corrections officers were sampled. Results show that correctional attitudes are largely influenced by not only officers' own motivations for joining corrections but also by institutional factors such as job stress. Policy implications are discussed. PMID:15538029

  17. Position Effect of Circumferential Crack Defects on Elbow Pipe Bearing Capacity%周向缺陷位置对弯管承载能力的影响

    Institute of Scientific and Technical Information of China (English)

    万晋; 秦超

    2016-01-01

    Taking elbow pipe as the object of study, the finite element method was adopted to investigate axial stress distribution on the cross section of the elbow pipe and plastic limit load;and the stress distribution there under internal pressure and bending load was summarized, including location of the maximum axial stress and its calculation formulation. Analyzing the position effect of circumferential crack defects on the elbow pipe’ s bearing capacity shows that, as for the elbow pipe with smaller bending radius and bigger diameter-thickness ratio, the circumferential crack defect should be located at the spot of the maximal axial stress so as to deter-mine the elbow’ s bearing capacity and lay the foundation for further study of the plastic ultimate bending mo-ment and improvement of elbow failure assessment.%以弯管为研究对象,采用有限元法对弯管中间横截面应力分布规律和塑性极限载荷进行研究,给出了弯管在内压和弯矩载荷下的应力分布情况,指出了弯矩载荷下弯管中间截面最大轴向应力点位置和计算公式,分析了中间截面上不同位置周向裂纹缺陷对弯管塑性极限弯矩载荷的影响。结果表明,对于弯曲半径比较小,径厚比较大的弯管应将周向裂纹缺陷定位在最大轴向应力点确定弯管弯矩承载能力,为进一步研究弯管塑性极限弯矩,完善弯管失效评定奠定基础。

  18. Minimally Invasive Pedicle Screw Fixation Combined with Vertebroplasty with Calcium Phosphate Bone Cement in the Treatment of Thoracolumbar Burst Fracture%微创椎弓根钉内固定联合磷酸钙骨水泥椎体成形术治疗胸腰椎爆裂性骨折

    Institute of Scientific and Technical Information of China (English)

    顾宇彤; 梁朝革; 张亮; 林红; 周健

    2015-01-01

    ,who suffered from single fresh thoracolumbar burst fracture without neurologic deficits and were classified as A3 fracture located between T11~L2 ,underwent the procedure of minimally invasive pedicle screw fixation combined with PVP with calcium phosphate bone cement .Duration of operation and blood loss ,injected volume of bone cement and length of stay ,were recorded .Lumbago and backache scores assessed by visual analogue scale (VAS) were recorded before surgery ,immediately after surgery ,as well as 1 month ,2 months ,3 months ,6 months ,1 year and 2 years after surgery . Vertebral compression rate and restoring rate ,Cobb angle and correction rate of vertebral kyphosis ,were measured at each time point and compared among the time points .Results:The average injected volume of calcium phosphate bone cement was 4 .9(3 .8~6 .4)mL .The mean duration of operation was 92(75~120)min .The average blood loss was 52(40~75)mL .The mean length of stay was 5 .6(4~ 7) d and the average follow‐up period was 26 months (24 ~ 29) .The VAS significantly decreased from 8 .8 ± 1 .2 before surgery to 1 .8 ± 0 .6 immediately after surgery and 0 .4 ± 0 .5 at 2 years after surgery ,and the differences were statistically significant(P< 0 .001) .The compression rate of vertebral body height decreased from(50 .4 ± 7 .2)% before surgery to (6 .2 ± 1 .5)% immediately after surgery and(6 .9 ± 1 .4)% at 2 years after surgery ,and the differences were statistically significant(P<0 .001) .The Cobb angle decreased from (22 .6 ± 1 .8)° before surgery to (3 .2 ± 1 .7)° immediately after surgery and (5 .1 ± 1 .5)° at 2 years after surgery ,and the differences were statistically significant(P<0 .001) .No significant decrease in both kyphosis correction and vertebral body height restoration was observed during the follow‐up .There was no loosen screw or broken screw .Conclusions:Minimally invasive pedicle screw fixation combined with PVP with calcium phosphate bone cement is a safe and

  19. Corrective action program

    International Nuclear Information System (INIS)

    Prior to the implementation of the Corrective Action Program in Asco NPP, the station was already using a number of systems for troubleshooting problems and identifying areas for improvement in areas such as maintenance, operating experience and quality insurance. These systems coexisted with little interaction among each other. The publication of UNESA Guide CEN-13 led Asco NPP to implement the Program, which was then included in the SISC (Inspection Base Plan for Integrated Supervision System of NPPs), which is the Spanish version of the ROP. (Author).

  20. Brain Image Motion Correction

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Benjaminsen, Claus; Larsen, Rasmus;

    2015-01-01

    The application of motion tracking is wide, including: industrial production lines, motion interaction in gaming, computer-aided surgery and motion correction in medical brain imaging. Several devices for motion tracking exist using a variety of different methodologies. In order to use such devices...... offset and tracking noise in medical brain imaging. The data are generated from a phantom mounted on a rotary stage and have been collected using a Siemens High Resolution Research Tomograph for positron emission tomography. During acquisition the phantom was tracked with our latest tracking prototype...

  1. OCT Motion Correction

    Science.gov (United States)

    Kraus, Martin F.; Hornegger, Joachim

    From the introduction of time domain OCT [1] up to recent swept source systems, motion continues to be an issue in OCT imaging. In contrast to normal photography, an OCT image does not represent a single point in time. Instead, conventional OCT devices sequentially acquire one-dimensional data over a period of several seconds, capturing one beam of light at a time and recording both the intensity and delay of reflections along its path through an object. In combination with unavoidable object motion which occurs in many imaging contexts, the problem of motion artifacts lies in the very nature of OCT imaging. Motion artifacts degrade image quality and make quantitative measurements less reliable. Therefore, it is desirable to come up with techniques to measure and/or correct object motion during OCT acquisition. In this chapter, we describe the effect of motion on OCT data sets and give an overview on the state of the art in the field of retinal OCT motion correction.

  2. Contact Lenses for Vision Correction

    Science.gov (United States)

    ... Ask an Ophthalmologist Español Eye Health / Glasses & Contacts Contact Lenses Sections Contact Lenses for Vision Correction Proper ... to Know About Contact Lenses Colored Contact Lenses Contact Lenses for Vision Correction Written by: Kierstan Boyd ...

  3. Mixed Burst Error Correcting Codes

    OpenAIRE

    Sethi, Amita

    2015-01-01

    In this paper, we construct codes which are an improvement on the previously known block wise burst error correcting codes in terms of their error correcting capabilities. Along with different bursts in different sub-blocks, the given codes also correct overlapping bursts of a given length in two consecutive sub-blocks of a code word. Such codes are called mixed burst correcting (mbc) codes.

  4. Geologic interpretations of seismic data Route 128 (Northern Circumferential Highway) cut, and Hopkins Street grade separation stations 1-18 in Wakefield, Mass.

    Science.gov (United States)

    May, James E.; Lineham, Rev. Daniel

    1950-01-01

    The completion of a segment of the Northern Circumferential Highway, Route 126, in Wakefield, Mass., requires an underpass bridge at Hopkins Street, Station 5+50. The plan of the project shows approximately 1800 feet if approach cuts between stations 1 and 18. In October 1945 a preliminary seismic study was made of a segment of this cut between stations 6+50 and 13+30. Four profiles were made at this time and a report was submitted by Newton E. Chute and Rev. Daniel Linhan (file report of January 15). This work showed a relatively shallow (in general, 6 to 12 feet in depth) somewhat irregular bedrock surface between stations 6+50 and 13+50. That data indicated that much of this segment of the cut will be in bedrock. In order to obtain more complete data for the preparation of detailed estimates on the amount of bedrock to be excavated for this segment of the cut, and also to obtain sufficient data for the unexplored segment of the cut, 21 additional seismic traverses were made in September 1949. The present report contains only the results obtained from this later work. The work was performed as a part of a cooperative program of the Massachusetts Department of Public Works and the United States Geological Survey.

  5. Learning Curve in a Western Training Center of the Circumferential En Bloc Esophageal Endoscopic Submucosal Dissection in an In Vivo Animal Model

    Directory of Open Access Journals (Sweden)

    Miguel A. Tanimoto

    2011-01-01

    Full Text Available Aim. Evaluate the feasibility to overcome the learning curve in a western training center of the en bloc circumferential esophageal (ECE- ESD in an in vivo animal model. Methods. ECE-ESD was performed on ten canine models under general anesthesia on artificial lesions at the esophagus marked with coagulation points. After the ESD each canine model was euthanized and surgical resection of the esophagus and stomach was carried out according to “the Principles of Humane Experimental Technique, Russel and Burch.” The specimen was fixed with needles on cork submerged in formalin with the esophagus and stomach then delivered to the pathology department to be analyzed. Results. ECE-ESD was completed without complications in the last 3/10 animal models. Mean duration for the procedures was 192±35 minutes (range 140–235 minutes. All the procedures were done at the animal lab surgery room with cardio pulmonary monitoring and artificial ventilation by staff surgery members and a staff member of the Gastroenterology department trained during 1999–2001 at the Fujigaoka hospital of the Showa U. in Yokohama, Japan, length (range 15–18 mm and 51±6.99 width (range 40–60 mm. Conclusion. ECE-ESD training is feasible in canine models for postgraduate endoscopy fellows.

  6. Creep-fatigue crack initiation and growth on thick circumferentially notched 316L tubes under cyclic thermal shocks and uniform tension

    International Nuclear Information System (INIS)

    A validated methodology for the assessment of flaws in the creep-fatigue regime is needed for safety studies in fast reactor applications. A usual approach, but often too conservative, leads to consider all the types of situations as load controlled ones for the analysis. The TERFIS test program performed at CEA Cadarache has the objective to give quantitative estimations of initiation times and subsequent crack growth of flaws in representative creep-fatigue conditions of the LMFBR structures (low primary stresses, high secondary stresses). The structures tested are thick 316L tubes with inner radius to thickness ratio Ri/t of 1.5 and complete circumferential inner wall electro-eroded notches submitted to uniform tension and cyclic thermal shocks giving rise to radial temperature gradients. The cycles are separated by dwells of 2 hours at 600 deg. C. After a brief description of the test device, the present work gives some first results and interpretation using a proposed methodology involving elasto-plastic finite elements calculations. (author)

  7. Generation of plastic influence functions for J-integral and crack opening displacement of thin-walled pipes with a short circumferential through-wall crack

    International Nuclear Information System (INIS)

    Fracture mechanics parameters such as the J-integral and crack opening displacement (COD), are necessary for Leak-Before-Break (LBB) evaluation. The famous two estimation methods, the GE/EPRI and the Reference Stress Method (RSM), have their applicability limit with regard to the ratio of a pipe mean radius to thickness (Rm/t). In order to extend their applicability limit to a thin walled pipe, several finite element analyses are performed for the J-integral and COD, and then new plastic influence functions are developed for thin-walled pipes with a short circumferential through-wall crack. With the newly generated plastic influence functions, the GE/EPRI and the RSM give closer results with those obtained from detailed finite element analyses. In addition, C*-integral and COD rate are estimated by using the new plastic influence functions and they are well matched with elastic–creep finite element analysis results under the power-law creep condition. Since the LBB concept can be applied to a piping system in a Korean Sodium-cooled Fast Reactor (SFR) which is designed to have thin-walled pipes and to operate in high temperature enough to cause creep, this paper can be applied for the LBB assessment of thin-walled pipes with a short through-wall crack in the SFR

  8. Simplified method to evaluate upper limit stress intensity factor range of an inner-surface circumferential crack under steady state thermal striping

    International Nuclear Information System (INIS)

    Simplified method to evaluate the upper limit stress intensity factor (SIF) range of an inner-surface circumferential crack in a thin- to thick-walled cylinder under steady state thermal striping was considered in this paper. The edges of the cylinder were rotation-restrained and the outer surface was adiabatically insulated. The inner surface of the cylinder was heated by a fluid with constant heat transfer coefficient whose temperature fluctuated sinusoidally at constant amplitude ΔT. By combining our analytical temperature solution for the problem and our semi-analytical-numerical SIF evaluation method for the crack, we showed that the desired maximum steady state SIF range can be evaluated with an engineering accuracy after ΔT, the mean radius to wall thickness ratio r m/W of the cylinder, the thermal expansion coefficient and Poisson's ratio are specified. By applying our method, no transient SIF analysis nor sensitivity analysis of the striping frequency on the SIF range is necessary. Numerical results showed that our method is valid for cylinders in a range of r m/W = 10-1

  9. Experimental and analytical studies of leak-before-break on circumferentially through-wall cracked pipes under bending load : Part-1 (September 1993 - June 1994)

    International Nuclear Information System (INIS)

    Fracture control of structures is the concerted efforts by designers, metallurgists, production and maintenance engineers and inspectors to ensure safe operation without catastrophic fracture failures. If fracture is to be prevented, the strength should not drop below a certain safe value which means that cracks must be prevented to reach a critical size. Since piping is very important component in nuclear power plants, fracture control plans have been employed increasingly to ensure for better plant availability. Leak-before break (LBB) is now widely applied in nuclear industries as a means of assessing the susceptibility of a pressurised components to failure by unstable crack growth. In this report experimental and analytical studies are conducted on circumferential through wall cracked pipe subjected to pure bending load. Pipes made of three different types of steels are tested with crack size varying from 15% to 50% of circumference. Experimental results pertaining to fracture load, crack mouth opening displacement (CMOD), load point rotation and J-integral are presented. Prediction of maximum moment and stress based on net-section collapse (NSC) method and modified NSC method are also presented and compared with experimental data. Comparison between experimental and analytical results were found to be good. These all studies throw some more light on the understanding of the pipe fracture and relative accuracy and margin of conservatism of the methods when applied to full scale set up. (author). 32 refs., 45 figs., 12 tabs., 2 appendixes

  10. Plastic collapse moment of 90 deg. long radius elbows with internal circumferential surface crack at intrados under in-plane bending

    International Nuclear Information System (INIS)

    Piping elbows under in-plane bending moment are vulnerable to cracking. The crack initiates at the surface and eventually reaches through the thickness and may lead to failure. The structural integrity assessment requires knowledge of the limit load. Limit load solutions for elbows with through-wall crack configurations are available in the open literature. But solutions for surface crack are not available. This paper presents a closed form expression for the plastic collapse moment (PCM) of 90 deg., long radius elbows with circumferential surface cracks at the intrados, under in-plane bending moment. The expression is derived, based on the results of non-linear (geometric and material) FE analyses covering a wide range of geometries and crack sizes. These plastic collapse moments evaluated herein will help in structural integrity assessment. - Highlights: → Piping elbows under in-plane bending moment are vulnerable to cracking. → Structural integrity assessment requires limit load solution. → presents a closed form expression for PCM of cracked elbow. → Results will help in structural integrity assessment of cracked elbows.

  11. Thromboembolic event rate in patients with persistent or paroxysmal atrial fibrillation post circumferential pulmonary vein isolation:a single center experience in China

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jing-min; LIU Shao-wen; LIN Jia-xiong; NIE Zhen-ning; WU Hong-yi; ZHOU Jun; HAO Ying; CAI Nai-sheng; GE Jun-bo

    2007-01-01

    Background Pulmonary-vein isolation (PVI) is currently used for the treatment of chronic and paroxysmal atrial fibrillation and a major risk of PVI is thromboembolism. The purpose of this study was to observe embolic event rate in patients with persistent or paroxysmal atrial fibrillation (AF) undergone PVI.Methods Circumferential PVI (CPVI) was performed in 64 consecutive patients with persistent AF (42 men, aged (60.0±9.1) years) and in 84 consecutive patients with paroxysmal AF (53 men, aged (61.4±9.3) years). Warfarin was administrated in all patients before ablation for at least 3 weeks ((5.2±2.6) weeks) and continued for at least 3 months post ablation with international normalized ratio (INR) of 2.0-3.0. During CPVI, intravenous heparin was given at a dose of 5000-8000 U or 75-100 U/kg, followed by 1000 U or 12 U/kg per hour.Results In patients with persistent AF, 1 patient developed embolic event during ablation and 3 patients developed embolic events after ablation. In contrast, no thromboembolic event was observed in patients with paroxysmal AF (4/64vs 0/84, P=0. 033).Conclusion Thromboembolic event rate related to CPVI is significantly higher in patients with persistent AF than that in patients with paroxysmal AF.

  12. Aloenxerto circunferencial de femur proximal em cirurgia de revisäo de artroplastia total de quadril: relato de casos com seguimento mínimo de 20 anos Circumferential proximal femoral allografts in revision surgery on total hip arthroplasty: case reports with a minimum follow-up of 20 years

    Directory of Open Access Journals (Sweden)

    Bruno Dutra Roos

    2012-01-01

    Full Text Available Dentre as opções para reconstrução femoral em cirurgias de revisão de artroplastia total do quadril (RATQ em defeitos circunferenciais extensos está a utilização de aloenxerto de fêmur proximal. O seu uso permite a correção do mecanismo abdutor do quadril e da discrepância de comprimento dos membros inferiores, além de apresentar potencial osteocondutivo. Os autores relatam os achados clínicos e radiográficos de dois casos de RATQ com uso desta técnica, em seguimento mínimo de 20 anos.Among the options for femoral reconstruction in total hip arthroplasty (THA revision procedures, in cases of extensive circumferential defects, is the use of proximal femoral allografts. This technique makes it possible to correct the hip abductor mechanism and the leg length discrepancy, as well as presenting osteoconductive potential. The authors report the clinical and radiographic results from two cases of THA revision using this technique, with a minimum follow-up of 20 years.

  13. Anomaly Corrected Heterotic Horizons

    CERN Document Server

    Fontanella, A; Papadopoulos, G

    2016-01-01

    We consider supersymmetric near-horizon geometries in heterotic supergravity up to two loop order in sigma model perturbation theory. We identify the conditions for the horizons to admit enhancement of supersymmetry. We show that solutions which undergo supersymmetry enhancement exhibit an sl(2,R) symmetry, and we describe the geometry of their horizon sections. We also prove a modified Lichnerowicz type theorem, incorporating $\\alpha'$ corrections, which relates Killing spinors to zero modes of near-horizon Dirac operators. Furthermore, we demonstrate that there are no AdS2 solutions in heterotic supergravity up to second order in $\\alpha'$ for which the fields are smooth and the internal space is smooth and compact without boundary. We investigate a class of nearly supersymmetric horizons, for which the gravitino Killing spinor equation is satisfied on the spatial cross sections but not the dilatino one, and present a description of their geometry.

  14. XRF matrix corrections

    International Nuclear Information System (INIS)

    Full text: In order to obtain meaningful analytical information from an X-Ray Fluorescence spectrometer, it is necessary to correlate measured intensity values with sample concentrations. The ability to do this to a desired level of precision depends on taking care of a number of variables which influence measured intensity values. These variables include: the sample, which needs to be homogeneous, flat and critically thick to the analyte lines used for measurement; the spectrometer, which needs to perform any mechanical movements in a highly reproducible manner; the time taken to measure an analyte line, and the software, which needs to take care of detector dead-time, the contribution of background to the measured signal, the effects of line overlaps and matrix (absorption and enhancement) effects. This presentation will address commonly used correction procedures for matrix effects and their relative success in achieving their objective. Copyright (2002) Australian X-ray Analytical Association Inc

  15. Temperature Corrected Bootstrap Algorithm

    Science.gov (United States)

    Comiso, Joey C.; Zwally, H. Jay

    1997-01-01

    A temperature corrected Bootstrap Algorithm has been developed using Nimbus-7 Scanning Multichannel Microwave Radiometer data in preparation to the upcoming AMSR instrument aboard ADEOS and EOS-PM. The procedure first calculates the effective surface emissivity using emissivities of ice and water at 6 GHz and a mixing formulation that utilizes ice concentrations derived using the current Bootstrap algorithm but using brightness temperatures from 6 GHz and 37 GHz channels. These effective emissivities are then used to calculate surface ice which in turn are used to convert the 18 GHz and 37 GHz brightness temperatures to emissivities. Ice concentrations are then derived using the same technique as with the Bootstrap algorithm but using emissivities instead of brightness temperatures. The results show significant improvement in the area where ice temperature is expected to vary considerably such as near the continental areas in the Antarctic, where the ice temperature is colder than average, and in marginal ice zones.

  16. Deconvolution with correct sampling

    CERN Document Server

    Magain, P; Sohy, S

    1997-01-01

    A new method for improving the resolution of astronomical images is presented. It is based on the principle that sampled data cannot be fully deconvolved without violating the sampling theorem. Thus, the sampled image should not be deconvolved by the total Point Spread Function, but by a narrower function chosen so that the resolution of the deconvolved image is compatible with the adopted sampling. Our deconvolution method gives results which are markedly superior to those of other existing techniques: in particular, it does not produce ringing around point sources superimposed on a smooth background. Moreover, it allows to perform accurate astrometry and photometry of crowded fields. These improvements are a consequence of both the correct treatment of sampling and the recognition that the most probable astronomical image is not a flat one. The method is also well adapted to the optimal combination of different images of the same object, as can be obtained, e.g., via adaptive optics techniques.

  17. EDITORIAL: Politically correct physics?

    Science.gov (United States)

    Pople Deputy Editor, Stephen

    1997-03-01

    If you were a caring, thinking, liberally minded person in the 1960s, you marched against the bomb, against the Vietnam war, and for civil rights. By the 1980s, your voice was raised about the destruction of the rainforests and the threat to our whole planetary environment. At the same time, you opposed discrimination against any group because of race, sex or sexual orientation. You reasoned that people who spoke or acted in a discriminatory manner should be discriminated against. In other words, you became politically correct. Despite its oft-quoted excesses, the political correctness movement sprang from well-founded concerns about injustices in our society. So, on balance, I am all for it. Or, at least, I was until it started to invade science. Biologists were the first to feel the impact. No longer could they refer to 'higher' and 'lower' orders, or 'primitive' forms of life. To the list of undesirable 'isms' - sexism, racism, ageism - had been added a new one: speciesism. Chemists remained immune to the PC invasion, but what else could you expect from a group of people so steeped in tradition that their principal unit, the mole, requires the use of the thoroughly unreconstructed gram? Now it is the turn of the physicists. This time, the offenders are not those who talk disparagingly about other people or animals, but those who refer to 'forms of energy' and 'heat'. Political correctness has evolved into physical correctness. I was always rather fond of the various forms of energy: potential, kinetic, chemical, electrical, sound and so on. My students might merge heat and internal energy into a single, fuzzy concept loosely associated with moving molecules. They might be a little confused at a whole new crop of energies - hydroelectric, solar, wind, geothermal and tidal - but they could tell me what devices turned chemical energy into electrical energy, even if they couldn't quite appreciate that turning tidal energy into geothermal energy wasn't part of the

  18. A study of circumferentially-heated and block-heated heat pipes. I - Experimental analysis and generalized analytical prediction of capillary limits. II - Three-dimensional numerical modeling as a conjugate problem

    Science.gov (United States)

    Schmalhofer, Joseph; Faghri, Amir

    1993-01-01

    The wall and centerline vapor temperatures and heat output are determined experimentally for a low-temperature copper-water heat pipe under uniform circumferential heating and block heating. The time required to reach a vapor temperature of 60 C from an initial ambient temperature of 21 C is determined for both modes of heating. The experimental capillary limit of the heat pipe is compared to the generalized capillary limits for block-heated pipes over a range of vapor temperatures. A three-dimensional numerical model is then developed for determining the temperature, pressure, and velocity distributions in the entire domain of a circumferentially heated and a block-heated pipe. The problem is formulated as a conjugate problem, without the assumption of a uniform vapor temperature. The predictions of the model are found to be in good agreement with the experimental data.

  19. Thermodynamics of Error Correction

    Science.gov (United States)

    Sartori, Pablo; Pigolotti, Simone

    2015-10-01

    Information processing at the molecular scale is limited by thermal fluctuations. This can cause undesired consequences in copying information since thermal noise can lead to errors that can compromise the functionality of the copy. For example, a high error rate during DNA duplication can lead to cell death. Given the importance of accurate copying at the molecular scale, it is fundamental to understand its thermodynamic features. In this paper, we derive a universal expression for the copy error as a function of entropy production and work dissipated by the system during wrong incorporations. Its derivation is based on the second law of thermodynamics; hence, its validity is independent of the details of the molecular machinery, be it any polymerase or artificial copying device. Using this expression, we find that information can be copied in three different regimes. In two of them, work is dissipated to either increase or decrease the error. In the third regime, the protocol extracts work while correcting errors, reminiscent of a Maxwell demon. As a case study, we apply our framework to study a copy protocol assisted by kinetic proofreading, and show that it can operate in any of these three regimes. We finally show that, for any effective proofreading scheme, error reduction is limited by the chemical driving of the proofreading reaction.

  20. IRI topside correction

    International Nuclear Information System (INIS)

    The topside segment of the International Reference Ionosphere (IRI) electron density model (and also of the Bent model) is based on the limited amount of topside data available at the time (∼40,000 Alouette 1 profiles). Being established from such a small database it is therefore not surprising that these models have well-known shortcomings, for example, at high solar activities. Meanwhile a large data base of close to 200,000 topside profiles from Alouette 1, 2, and ISIS 1, 2 has become available online. A program of automated scaling and inversion of a large volume of digitized ionograms adds continuously to this data pool. We have used the currently available ISIS/Alouette topside profiles to evaluate the IRI topside model and to investigate ways of improving the model. The IRI model performs generally well at middle latitudes and shows discrepancies at low and high latitudes and these discrepancies are largest during high solar activity. In the upper topside IRI consistently overestimates the measurements. Based on averages of the data-model ratios we have established correction factors for the IRI model. These factors vary with altitude, modified dip latitude, and local time. (author)

  1. Intraoperative Radiation Therapy Reduces Local Recurrence Rates in Patients With Microscopically Involved Circumferential Resection Margins After Resection of Locally Advanced Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alberda, Wijnand J.; Verhoef, Cornelis [Department of Surgery, Division of Surgical Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Nuyttens, Joost J. [Department of Radiotherapy, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Meerten, Esther van [Department of Medical Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Rothbarth, Joost [Department of Surgery, Division of Surgical Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands); Wilt, Johannes H.W. de [Department of Surgery, Division of Surgical Oncology, Radboud University Nijmegen Medical Center, Nijmegen (Netherlands); Burger, Jacobus W.A., E-mail: j.burger@erasmusmc.nl [Department of Surgery, Division of Surgical Oncology, Erasmus MC Cancer Institute, Rotterdam (Netherlands)

    2014-04-01

    Purpose: Intraoperative radiation therapy (IORT) is advocated by some for patients with locally advanced rectal cancer (LARC) who have involved or narrow circumferential resection margins (CRM) after rectal surgery. This study evaluates the potentially beneficial effect of IORT on local control. Methods and Materials: All surgically treated patients with LARC treated in a tertiary referral center between 1996 and 2012 were analyzed retrospectively. The outcome in patients treated with IORT with a clear but narrow CRM (≤2 mm) or a microscopically involved CRM was compared with the outcome in patients who were not treated with IORT. Results: A total of 409 patients underwent resection of LARC, and 95 patients (23%) had a CRM ≤ 2 mm. Four patients were excluded from further analysis because of a macroscopically involved resection margin. In 43 patients with clear but narrow CRMs, there was no difference in the cumulative 5-year local recurrence-free survival of patients treated with (n=21) or without (n=22) IORT (70% vs 79%, P=.63). In 48 patients with a microscopically involved CRM, there was a significant difference in the cumulative 5-year local recurrence-free survival in favor of the patients treated with IORT (n=31) compared with patients treated without IORT (n=17) (84 vs 41%, P=.01). Multivariable analysis confirmed that IORT was independently associated with a decreased local recurrence rate (hazard ratio 0.24, 95% confidence interval 0.07-0.86). There was no significant difference in complication rate of patients treated with or without IORT (65% vs 52%, P=.18) Conclusion: The current study suggests that IORT reduces local recurrence rates in patients with LARC with a microscopically involved CRM.

  2. Intraoperative Radiation Therapy Reduces Local Recurrence Rates in Patients With Microscopically Involved Circumferential Resection Margins After Resection of Locally Advanced Rectal Cancer

    International Nuclear Information System (INIS)

    Purpose: Intraoperative radiation therapy (IORT) is advocated by some for patients with locally advanced rectal cancer (LARC) who have involved or narrow circumferential resection margins (CRM) after rectal surgery. This study evaluates the potentially beneficial effect of IORT on local control. Methods and Materials: All surgically treated patients with LARC treated in a tertiary referral center between 1996 and 2012 were analyzed retrospectively. The outcome in patients treated with IORT with a clear but narrow CRM (≤2 mm) or a microscopically involved CRM was compared with the outcome in patients who were not treated with IORT. Results: A total of 409 patients underwent resection of LARC, and 95 patients (23%) had a CRM ≤ 2 mm. Four patients were excluded from further analysis because of a macroscopically involved resection margin. In 43 patients with clear but narrow CRMs, there was no difference in the cumulative 5-year local recurrence-free survival of patients treated with (n=21) or without (n=22) IORT (70% vs 79%, P=.63). In 48 patients with a microscopically involved CRM, there was a significant difference in the cumulative 5-year local recurrence-free survival in favor of the patients treated with IORT (n=31) compared with patients treated without IORT (n=17) (84 vs 41%, P=.01). Multivariable analysis confirmed that IORT was independently associated with a decreased local recurrence rate (hazard ratio 0.24, 95% confidence interval 0.07-0.86). There was no significant difference in complication rate of patients treated with or without IORT (65% vs 52%, P=.18) Conclusion: The current study suggests that IORT reduces local recurrence rates in patients with LARC with a microscopically involved CRM

  3. Can histopathologic assessment of circumferential margin after preoperative pelvic chemoradiotherapy for T3-T4 rectal cancer predict for 3-year disease-free survival?

    International Nuclear Information System (INIS)

    Purpose: This study set out to determine the impact of a positive circumferential resection margin (CRM) (R1-R2) and pathologic downstaging on local recurrence and survival in patients with borderline resectable or unresectable rectal adenocarcinoma treated with neoadjuvant chemoradiotherapy (CRT). Methods and Materials: A total of 150 patients with locally advanced rectal cancer were treated with long-course neoadjuvant CRT using low-dose folinic acid and 5-fluorouracil. CRT was followed 6-12 weeks later by surgical excision. The CRM rate and incidence, site, and pattern of local and systemic recurrences were recorded. The median follow-up was 25 months. Results: The overall median survival was 37 months, with a 5-year overall survival rate of 34%. Of the 150 patients, 122 underwent curative resection; 12% had a complete pathologic response, and downstaging to pT1-T2 occurred in an additional 16%. A negative CRM (R0) was achieved in 65% overall (98 of 150). Local recurrence occurred in 10% of those with R0 resection and 62% of those with R1-R2 resections. Distant metastases occurred in 29% of those with R0 resections and 75% of those with R1-R2 resections. The 3-year disease-free and 3-year overall survival rate was 9% and 25% and 52% and 64%, respectively, for patients with and without a histologically positive CRM. Conclusion: After 5-fluorouracil-based CRT, a positive CRM predicted for a high risk of subsequent local recurrence and a 3-year disease-free survival rate of only 9%. For this reason, the CRM should be considered a major prognostic factor and should be validated in future trials as an early alternative clinical endpoint

  4. 观察胸腰椎多节段脊柱骨折手术治疗的临床疗效%Observation on Clinical Effect of Surgery for Spinal Fracture of Thora-columbar Segments

    Institute of Scientific and Technical Information of China (English)

    李少平; 杨光勇; 潘继春

    2015-01-01

    目的:探讨胸腰椎多节段脊柱骨折手术的临床疗效。方法该研究报告选取了在该院接受治疗的胸腰椎多节段脊柱骨折患者60例为研究对象,征求患者治疗意愿后,分为观察组与对照组,观察组采用前路手术治疗,对照组采用后路手术治疗,分别采用不同术后观察患者手术疗效。结果对照组椎体前缘高度为(22.28±4.02),后凸角为(17.61±2.88),观察组前缘高度为(32.01±4.32),后凸角为(5.23±3.08),观察组病变椎体的平均高度有显著改善(P0.05),观察组患者治疗有效率为96.67%;对照组患者治疗有效率为93.33%。结论临床上在治疗胸腰椎多节段脊椎骨折时,应根据患者不同的骨折情况给予患者不同的手术治疗,[A1]前路手术对改善胸腰椎多节段脊柱骨折患者椎体前缘高度以及后凸角有着重要的作用,帮助患者减轻椎体压力,并对脊柱起良好固定作用。%Objective To investigate the clinical curative effect of surgery for spinal fracture of thoracolumbar segments. Methods This study selected 60 patients in the hospital for treatment of thoracolumbar spine fracture as the research object and divided into observation group and control group with patients' preferences. The observation group was given the anterior surgical treatment, while the control group was treated by posterior approach. Postoperative surgical curative effect of the two groups was observed. Results Control group fanterior flange height is (22.28±4.02), lobe was (17.61±2.88), after the observation group leading edge height is(32.01±4.32)mm, lobe was(5.23±3.08), after the observation group of lesions the average height of the vertebral body has improved significantly (P0.05), the observation group of patients treatment effective rate was 96.67%;The control group patients treatment effective rate was 93.33%. Conclusion Clinical in the treatment of thoracolumbar vertebral fractures, should

  5. 椎弓根内固定椎体后凸成形术治疗骨质疏松性胸腰椎骨折%Pedicle Screw Fixation Kyphoplasty in Treatment of Osteoporotic Thoracolumbar Fracture

    Institute of Scientific and Technical Information of China (English)

    柯勇

    2013-01-01

    目的探讨椎弓根内固定结合椎体后凸成形术治疗骨质疏松性胸腰椎骨折的方法及临床治疗的效果。方法自2011年2月~2012年2月本院采用后路切开椎弓根内固定结合椎体后凸成形术治疗13例骨质疏松性胸腰椎压缩性骨折患者。术后随访24个月,术后复查胸腰椎正侧位片。分别于术前、术后4d、末次随访用Oswestry功能障碍指数评分(oswestry disability index,ODI),X线片上测量椎体矢状面指数(sagittal index,SI)及Cobb角(SI=椎体前缘高度/椎体后缘高度),观察内固定及伤椎稳定及功能恢复情况。结果所有患者都未发生骨水泥渗漏,无神经症状的缺失。13例患者中,12例获平均20个月随访,末次随访时患者的功能恢复良好,未发现椎弓根钉松动、断裂。结论椎弓根内固定结合椎体后凸成形术为骨质疏松性胸腰椎压缩性骨折的手术治疗提供了一种安全、可靠的方法,改善了机体的功能,提高了患者的生活质量。%Objective To investigate the pedicle screw fixation combined with kyphoplasty treatment of osteoporotic thoracolumbar fractures and clinical treatment ef ect. Methods The hospital incision posterior pedicle screw fixation combined with kyphoplasty treatment of 13 cases of osteoporotic thoracolumbar vertebral compression fracture patients from February 2011 to February 2012 The patients were fol owed up for 24 months, after review of the thoracic and lumbar lateral radiographs. Preoperative and postoperative 4D, the last fol ow-up, the Oswestry Disability Index score (oswestry disability index, ODI), X-ray measurement the vertebral sagit al index (sagit al index, SI) and the Cobb angle (SI =vertebral edge height /posterior margin height), fixed and the injured vertebra stable and function recovery observed. Results Al patients had happened leakage of bone cement, the lack of neurological symptoms. 13 patients, 12 patients were an average of 20 months fol ow

  6. 胸腰椎骨折后部韧带复合体损伤中MRI诊断价值的探讨%Reliability of magnetic resonance imaging in diagnosing posterior ligament complex injury in thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    张涛; 冯世庆; 姜文学; 高延征

    2008-01-01

    Objective To analyze the reliability of magnetic resonance imaging (MRI) in detecting posterior ligament complex injury in thoracolumbar fractures. Methods Ninety-five patients with thoracolumbar fracture were evaluated by palpation of the interspinal gap, plain radiography, and MRI before operation. In addition to conventional MRI sequences, a fat-suppressed T2-weighted sagittal sequence was performed. Surgery was performed by a posterior approach. During the operation, posterior ligament complex was examined. Results A wide interspinal gap was palpated in 41 patients and was found in 55 patients on plain radiography. According to MRI, injury to the supraspinal ligament was suspected in 85 patients, the interspinal ligament in 83 patients, and the ligamenta tiara in 26 patients. There were 82 supraspinal ligament injuries, 80 interspinal ligament injuries, and 20 ligamenta flava injuries in operative findings. The relations between plain radiography and operative findings, between MRI interpretation and operative findings were statistically significant. Conclusion A fat-suppressed T2-weighted sagittal sequence of MRI is a highly sensitive, specific, and accurate method to detect posterior ligament complex injury and which is recommended for the accurate evaluation of posterior ligament complex injury in thoracolumbar fractures.%目的 评估MRI对诊断胸腰椎骨折患者后部韧带复合体损伤的可靠性. 方法 95例胸腰椎骨折患者,术前进行棘突间隙触诊、X线片、MRI检查,其中MRI检查在传统的成像基础上,加做矢状12抑脂序列.采用后入路手术,手术中仔细检查后部韧带复合体损伤情况. 结果 触诊棘突间隙增宽41例,X线片55例,MRI发现韧带复合体损伤85例,其中棘上韧带损伤85例,棘间韧带损伤83例,黄韧带损伤26例;手术发现棘上韧带损伤82例,棘间韧带损伤80例,黄韧带损伤20例.触诊与手术所见无相关性,X线片诊断、MRI诊断与

  7. Food systems in correctional settings

    DEFF Research Database (Denmark)

    Smoyer, Amy; Kjær Minke, Linda

    management of food systems may improve outcomes for incarcerated people and help correctional administrators to maximize their health and safety. This report summarizes existing research on food systems in correctional settings and provides examples of food programmes in prison and remand facilities......, including a case study of food-related innovation in the Danish correctional system. It offers specific conclusions for policy-makers, administrators of correctional institutions and prison-food-service professionals, and makes proposals for future research.......Food is a central component of life in correctional institutions and plays a critical role in the physical and mental health of incarcerated people and the construction of prisoners' identities and relationships. An understanding of the role of food in correctional settings and the effective...

  8. 注入骨水泥治疗胸腰椎骨质疏松性骨折:成熟技术中的常见问题%Bone cement injection for the treatment of thoracolumbar osteoporotic fractures:Common problems in the mature technology

    Institute of Scientific and Technical Information of China (English)

    韩卫东; 黄爱军; 陈丽萍

    2013-01-01

      背景:注入骨水泥是胸腰椎骨质疏松性骨折常用的固定方法之一。目的:评估注入骨水泥内固定胸腰椎骨质疏松性骨折的生物力学性能以及固定效果。方法:选取骨质疏松胸腰椎标本,测定骨密度以及最大压力载荷、位移、刚度等力学性能指标,建立骨折模型,注入骨水泥固定后,再次测定最大压力载荷、位移、刚度指标,比较注入骨水泥固定前后生物性能的变化,同时与椎弓根螺钉固定胸腰椎骨质疏松性骨折的生物学性能进行比较。对注入骨水泥固定胸腰椎骨质疏松性骨折的患者进行随访观察,通过评估患者缓解疼痛程度、胸腰椎体高度恢复程度以及骨水泥注入量和骨水泥外渗等情况,明确注入骨水泥固定治疗的效果。结果与结论:生物力学实验测定注入骨水泥固定胸腰椎骨质疏松性骨折后的最大载荷为2285 N,比骨折前承受的最大载荷1954 N强度增加了近16.9%,注入骨水泥固定胸腰椎骨质疏松性骨折后的刚度为427 N,比骨折前刚度349 N增加了近22.1%,显示出良好的生物性能。对应用注入骨水泥固定胸腰椎骨质疏松性骨折的患者以及应用闭合复位注入骨水泥固定胸腰椎骨质疏松性骨折的患者进行随访观察,结果发现2种方法均可以使患者的疼痛得到明显的缓解,而闭合复位注入骨水泥固定胸腰椎骨质疏松性骨折时骨水泥注入量、局部后凸角以及椎体高度恢复情况均更好,表明闭合复位辅助下注入骨水泥固定是胸腰椎骨质疏松性骨折安全有效的治疗方法。%  BACKGROUND: Bone cement injection is one of the commonly used methods for the treatment of thoracolumbar osteoporotic fractures. OBJECTIVE: To evaluate biomechanical properties and fixed effects of bone cement injection for the treatment of thoracolumbar osteoporotic fractures. METHODS: The specimens of

  9. Health care in correctional facilities.

    OpenAIRE

    Thorburn, K M

    1995-01-01

    More than 1.3 million adults are in correctional facilities, including jails and federal and state prisons, in the United States. Health care of the inmates is an integral component of correctional management. Health services in correctional facilities underwent dramatic improvements during the 1970s. Public policy trends beginning in the early 1980s substantially affected the demographics and health status of jail and prison populations and threatened earlier gains in the health care of inma...

  10. Corrective Feedback and Teacher Development

    OpenAIRE

    Ellis, Rod

    2009-01-01

    This article examines a number of controversies relating to how corrective feedback (CF) has been viewed in SLA and language pedagogy. These controversies address (1) whether CF contributes to L2 acquisition, (2) which errors should be corrected, (3) who should do the correcting (the teacher or the learner him/herself), (4) which type of CF is the most effective, and (5) what is the best timing for CF (immediate or delayed). In discussing these controversies, both the pedagogic and SLA litera...

  11. Comparison of Topographic Correction Methods

    Directory of Open Access Journals (Sweden)

    Rudolf Richter

    2009-07-01

    Full Text Available A comparison of topographic correction methods is conducted for Landsat-5 TM, Landsat-7 ETM+, and SPOT-5 imagery from different geographic areas and seasons. Three successful and known methods are compared: the semi-empirical C correction, the Gamma correction depending on the incidence and exitance angles, and a modified Minnaert approach. In the majority of cases the modified Minnaert approach performed best, but no method is superior in all cases.

  12. QCD corrections to triboson production

    Science.gov (United States)

    Lazopoulos, Achilleas; Melnikov, Kirill; Petriello, Frank

    2007-07-01

    We present a computation of the next-to-leading order QCD corrections to the production of three Z bosons at the Large Hadron Collider. We calculate these corrections using a completely numerical method that combines sector decomposition to extract infrared singularities with contour deformation of the Feynman parameter integrals to avoid internal loop thresholds. The NLO QCD corrections to pp→ZZZ are approximately 50% and are badly underestimated by the leading order scale dependence. However, the kinematic dependence of the corrections is minimal in phase space regions accessible at leading order.

  13. Entropic Corrections to Coulomb's Law

    Science.gov (United States)

    Hendi, S. H.; Sheykhi, A.

    2012-04-01

    Two well-known quantum corrections to the area law have been introduced in the literatures, namely, logarithmic and power-law corrections. Logarithmic corrections, arises from loop quantum gravity due to thermal equilibrium fluctuations and quantum fluctuations, while, power-law correction appears in dealing with the entanglement of quantum fields in and out the horizon. Inspired by Verlinde's argument on the entropic force, and assuming the quantum corrected relation for the entropy, we propose the entropic origin for the Coulomb's law in this note. Also we investigate the Uehling potential as a radiative correction to Coulomb potential in 1-loop order and show that for some value of distance the entropic corrections of the Coulomb's law is compatible with the vacuum-polarization correction in QED. So, we derive modified Coulomb's law as well as the entropy corrected Poisson's equation which governing the evolution of the scalar potential ϕ. Our study further supports the unification of gravity and electromagnetic interactions based on the holographic principle.

  14. Using neo-spinal surgery-preliminary positioning system for thoracolumbar diseases%新型脊柱术前节段定位系统在胸腰椎疾病中的应用

    Institute of Scientific and Technical Information of China (English)

    王小健; 苏云星; 常峰

    2015-01-01

    目的:利用新型脊柱术前定位系统治疗胸腰椎疾病,观察其临床应用效果。方法自2014年1月至8月我院骨科使用该系统诊治胸腰椎疾病患者共28例,同时期不使用该装置进行手术55例,从平均手术时间、平均暴露每椎节的皮肤切口长度、平均术中应用动态X线机的次数、术中出现的定位错误等方面进行统计分析。结果使用该系统组28例患者未出现定位错误等情况,在手术时间、减小切口长度、减少承受放射剂量等方面均优于对照组,且该系统操作简单。结论使用脊柱术前椎体定位系统在术中能准确定位脊柱节段,可以向临床推广。%Objective To use neo-spinal surgery-preliminary positioning system for the treatment of thora-columbar diseases, and to determine its clinical effects. Methods A total of 28 patients with thoracolumbar diseases underwent the neo-spinal surgery-preliminary positioning system between January 2014 and August 2014 in the De-partment of Orthopaedics of our hospital. A contemporary cohort of 55 cases did not use the system. The mean opera-tion time, mean length of skin incision of the exposed vertebral section, mean frequency of using the dynamic X-ray machine during the operation, and intraoperative positioning errors were statistically analyzed. Results No position-ing errors were found in 28 patients using neo-spinal surgery-preliminary positioning system. The operation time, de-creased incision length, and decreased radiation dose in the neo-spinal surgery-preliminary positioning system group were better than those in the control group. The operation of the neo-spinal surgery-preliminary positioning system is simple. Conclusion Using spinal surgery-preliminary positioning system can accurately position spinal segment, which justifies widespread use in clinical practice.

  15. Correct and efficient accelerator programming

    OpenAIRE

    Cohen, Albert; Donaldson, Alistair F.; Huisman, Marieke; Katoen, Joost-Pieter

    2013-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 13142 “Correct and Efficient Accelerator Programming”. The aim of this Dagstuhl seminar was to bring together researchers from various sub-disciplines of computer science to brainstorm and discuss the theoretical foundations, design and implementation of techniques and tools for correct and efficient accelerator programming.

  16. Jet Energy Corrections at CMS

    CERN Document Server

    Santocchia, Attilio

    2009-01-01

    Many physics measurements in CMS will rely on the precise reconstruction of Jets. Correction of the raw jet energy measured by the CMS detector will be a fundamental step for most of the analysis where hadron activity is investigated. Jet correction plans in CMS have been widely studied for different conditions: at stat-up simulation tuned on test-beam data will be used. Then data-driven methods will be available and finally, simulation tuned on collision data will give us the ultimate procedure for calculating jet corrections. Jet transverse energy is corrected first for pile-up and noise offset; correction for the response of the calorimeter as a function of jet pseudorapidity relative to the barrel comes afterwards and correction for the absolute response as a function of transverse momentum in the barrel is the final standard sub-correction applied. Other effects like flavour and parton correction will be optionally applied on the Jet $E_T$ depending on the measurement requests. In this paper w...

  17. Fine-Tuning Corrective Feedback.

    Science.gov (United States)

    Han, ZhaoHong

    2001-01-01

    Explores the notion of "fine-tuning" in connection with the corrective feedback process. Describes a longitudinal case study, conducted in the context of Norwegian as a second a language, that shows how fine-tuning and lack thereof in the provision of written corrective feedback differentially affects a second language learner's restructuring of…

  18. Relativistic corrections to stopping powers

    International Nuclear Information System (INIS)

    Relativistic corrections to the nonrelativistic Bethe-Bloch formula for the stopping power of matter for charged particles are traditionally computed by considering close collisions separately from distant collisions. The close collision contribution is further divided into the Mott correction appropriate for very small impact parameters, and the Bloch correction, computed for larger values. This division of the region of close collisions leads to a very cumbersome result if one generalizes the original Bloch procedure to relativistic energies. The authors avoid the resulting poorly specified scattering angle theta/sub o/ that divides the Mott and Bloch correction regimes by using the procedure suggested by Lindhard and applied by Golovchenko, Cox and Goland to determine the Bloch correction for relativistic velocities. 25 references, 2 figures

  19. Shell corrections in stopping powers

    Science.gov (United States)

    Bichsel, H.

    2002-05-01

    One of the theories of the electronic stopping power S for fast light ions was derived by Bethe. The algorithm currently used for the calculation of S includes terms known as the mean excitation energy I, the shell correction, the Barkas correction, and the Bloch correction. These terms are described here. For the calculation of the shell corrections an atomic model is used, which is more realistic than the hydrogenic approximation used so far. A comparison is made with similar calculations in which the local plasma approximation is utilized. Close agreement with the experimental data for protons with energies from 0.3 to 10 MeV traversing Al and Si is found without the need for adjustable parameters for the shell corrections.

  20. Diagnostic accuracy of computed tomography and magnetic resonance imaging obtained after neoadjuvant chemoradiotherapy in predicting the local tumor stage and circumferential resection margin status of rectal cancer

    International Nuclear Information System (INIS)

    To measure the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI) obtained after neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer for a prediction of the local tumor stage and circumferential resection margin (CRM). Two independent radiologists reviewed CT and MRI obtained after neoadjuvant CRT. The accuracy of the local tumor staging and the diagnostic performance for the prediction of CRM involvement were calculated. The agreement between the measurements of the distance to potential CRM on both imaging modalities and the histopathology findings was assessed using Bland-Altman plots. 57 patients (mean age, 59.2 years; 24 females) were included. The accuracy of T and N staging were 43.9% (95% confidence interval, 30.8-57.7%) and 77.2% (64.2-87.3%) on CT and 63.2% (49.4-75.6%) and 77.2% (64.2-87.3%) on MRI for Observer 1. The accuracy of T and N staging were 54.4% (40.7-67.7%) and 77.2% (64.2-87.3%) on CT and 68.4% (54.7-80.1%) and 80.7% (68.1-90.0%) on MRI for Observer 2. Sensitivity and specificity on CRM involvement were 83.3% (43.7-97.0%) and 88.2% (76.6-94.5%) on CT and 100% (61.0-100%) and 90.2% (79.0-95.7%) on MRI for Observer 1. Sensitivity and specificity on CRM involvement were 66.7% (30.0-90.3%) and 88.2% (76.7-94.5%) on CT and 100% (61.0-100%) and 90.2% (79.0-95.7%) on MRI for Observer 2. Bland-Altman plots showed wide discrepancies between measurements of the distance to CRM on each CT and MRI and those on histopathology findings. CT and MRI showed limited performance in predicting the local tumor staging and CRM involvement in patients with neoadjuvant CRT although MRI tended to show a better performance than CT

  1. Holographic thermalization with Weyl corrections

    Science.gov (United States)

    Dey, Anshuman; Mahapatra, Subhash; Sarkar, Tapobrata

    2016-01-01

    We consider holographic thermalization in the presence of a Weyl correction in five dimensional AdS space. We first obtain the Weyl corrected black brane solution perturbatively, up to first order in the coupling. The corresponding AdS-Vaidya like solution is then constructed. This is then used to numerically analyze the time dependence of the two point correlation functions and the expectation values of rectangular Wilson loops in the boundary field theory, and we discuss how the Weyl correction can modify the thermalization time scales in the dual field theory. In this context, the subtle interplay between the Weyl coupling constant and the chemical potential is studied in detail.

  2. 聚乙烯管道热熔接头环向裂纹应力强度因子的数值分析%Numerical Analysis of Stress Intensity Factor for Circumferential Cracks of Polyethylene Pipe's Hot Melting Joints

    Institute of Scientific and Technical Information of China (English)

    朱志彬; 杨晓翔; 陈丽静; 林乃昌; 庄鹏辉

    2013-01-01

    应力强度因子K是缺陷结构安全评定的重要参数.基于粘弹性理论,将聚乙烯管材料的粘弹性参数用Prony级数表示,运用非线性有限元法,在ANSYS中建立聚乙烯管热熔接头环向裂纹模型,并对K进行计算和分析.通过有限元的模拟,总结得到聚乙烯管最可能发生断裂的时间为产生裂纹时刻,从而得出分析聚乙烯管环向表面裂纹应力强度因子时不必考虑聚乙烯管的黏弹性,环向表面裂纹缺陷的主要影响因素是裂纹深度与聚乙烯管的厚度之比.%Aiming at the PE pipe' s viscoelastic properties,the Ansys was used to simulate and analyze the hot melting connector' s mechanical properties of the PE pipe with circumferential surface cracks,and the Prony series was used to analog material's viscoelastic properties,as well as the 1/4 node singular element was used to mesh the volumes at the crack boundary and to calculate the stress intensity factor of the PE pipe under the well-distributed internal pressure.The finite element simulation shows that the time of PE pipe rupture is just the moment that the crack occurs,and it is unnecessary to take PE pipe' s viscoelasticity into account while calculating the stress intensity factor of circumferential surface cracks.The crack depth-PE pipe thickness ratio mainly influences the circumferential cracks.

  3. Brachial plexus palsy caused by halo traction before posterior correction in patients with severe scoliosis

    Institute of Scientific and Technical Information of China (English)

    QIAN Bang-ping; QIU Yong; WANG Bin; YU Yang; ZHU Ze-zhang

    2007-01-01

    Objective: To explore the clinical features and treatment results of brachial plexus palsy caused by halo traction before posterior correction in patients with severe scoliosis.Methods: A total of 300 cases of severe scoliosis received halo traction before posterior correction in our department from July 1997 to November 2004. Among them, 7 cases were complicated with brachial plexus palsy.The average Cobb angle was 110° (range, 90°-135°).Diagnoses were made as idiopathic scoliosis in 1 case,congenital scoliosis in 3 cases, and neuromuscular scoliosis in 3 cases. Additionally, diastematomyelia and tethered cord syndrome were found in 3 cases and thoracolumbar kyphosis in 2 cases. Weight of traction was immediately reduced when the patient developed any abnormal neurological symptoms in the upper extremity, and rehabilitation training was undertaken. Simultaneously,neurotrophic pharmacotherapy was applied, and the neurological function restoration of the upper limbs and the recovery time were documented.Results: Traction was used for an average of 3.5 weeks (range, 2-6 weeks) before spinal fusion for these 7 patients. The average traction weight was 8 kg, which was 19% on average (range, 13%-26%) of the average body weight (40.2 kg). These 7 patients had long and thin body configuration with a mean height of 175 cm. The duration between symptoms of brachial plexus paralysis and the diagnosis was 1-3 hours. All of these 7 patients presented various degrees of numbness in the ulnar side of the hand and forearm. Median nerve paresis was found in 3 cases and ulnar nerve paresis in 4 cases. Complete recovery of the neurological function had been achieved by the end of three months.Conclusions: The clinical features of brachial plexus palsy caused by halo traction include median nerve paresis,ulnar nerve paralysis, and numbness in the ulnar side of the hand and forearm, which may be due to the injury of the inferior part of the brachial plexus, i.e. , damage of Cs and

  4. Multipole correction in large synchrotrons

    International Nuclear Information System (INIS)

    A new method of correcting dynamic nonlinearities due to the multipole content of a synchrotron such as the Superconducting Super Collider is discussed. The method uses lumped multipole elements placed at the center (C) of the accelerator half-cells as well as elements near the focusing (F) and defocusing (D) quads. In a first approximation, the corrector strengths follow Simpson's Rule. Correction of second-order sextupole nonlinearities may also be obtained with the F, C, and D octupoles. Correction of nonlinearities by about three orders of magnitude are obtained, and simple solutions to a fundamental problem in synchrotrons are demonstrated. Applications to the CERN Large Hadron Collider and lower energy machines, as well as extensions for quadrupole correction, are also discussed

  5. Self-Correcting Quantum Computers

    CERN Document Server

    Bombin, H; Horodecki, M; Martín-Delgado, M A

    2009-01-01

    Is the notion of a quantum computer resilient to thermal noise unphysical? We address this question from a constructive perspective and show that local quantum Hamiltonian models provide self-correcting quantum computers. To this end, we first give a sufficient condition on the connectedness of excitations for a stabilizer code model to be a self-correcting quantum memory. We then study the two main examples of topological stabilizer codes in arbitrary dimensions and establish their self-correcting capabilities. Also, we address the transversality properties of topological color codes, showing that 6D color codes provide a self-correcting model that allows the transversal and local implementation of a universal set of operations in seven spatial dimensions. Finally, we give a procedure to initialize such quantum memories at finite temperature.

  6. Quantum corrections for Boltzmann equation

    Institute of Scientific and Technical Information of China (English)

    M.; Levy; PETER

    2008-01-01

    We present the lowest order quantum correction to the semiclassical Boltzmann distribution function,and the equation satisfied by this correction is given. Our equation for the quantum correction is obtained from the conventional quantum Boltzmann equation by explicitly expressing the Planck constant in the gradient approximation,and the quantum Wigner distribution function is expanded in pow-ers of Planck constant,too. The negative quantum correlation in the Wigner dis-tribution function which is just the quantum correction terms is naturally singled out,thus obviating the need for the Husimi’s coarse grain averaging that is usually done to remove the negative quantum part of the Wigner distribution function. We also discuss the classical limit of quantum thermodynamic entropy in the above framework.

  7. Spelling Correction in Agglutinative Languages

    CERN Document Server

    Oflazer, K

    1994-01-01

    This paper presents an approach to spelling correction in agglutinative languages that is based on two-level morphology and a dynamic programming based search algorithm. Spelling correction in agglutinative languages is significantly different than in languages like English. The concept of a word in such languages is much wider that the entries found in a dictionary, owing to {}~productive word formation by derivational and inflectional affixations. After an overview of certain issues and relevant mathematical preliminaries, we formally present the problem and our solution. We then present results from our experiments with spelling correction in Turkish, a Ural--Altaic agglutinative language. Our results indicate that we can find the intended correct word in 95\\% of the cases and offer it as the first candidate in 74\\% of the cases, when the edit distance is 1.

  8. Self-correcting quantum computers

    International Nuclear Information System (INIS)

    Is the notion of a quantum computer (QC) resilient to thermal noise unphysical? We address this question from a constructive perspective and show that local quantum Hamiltonian models provide self-correcting QCs. To this end, we first give a sufficient condition on the connectedness of excitations for a stabilizer code model to be a self-correcting quantum memory. We then study the two main examples of topological stabilizer codes in arbitrary dimensions and establish their self-correcting capabilities. Also, we address the transversality properties of topological color codes, showing that six-dimensional color codes provide a self-correcting model that allows the transversal and local implementation of a universal set of operations in seven spatial dimensions. Finally, we give a procedure for initializing such quantum memories at finite temperature. (paper)

  9. Radiative corrections to Bose condensation

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, A. (Academia de Ciencias de Cuba, La Habana. Inst. de Matematica, Cibernetica y Computacion)

    1985-04-01

    The Bose condensation of the scalar field in a theory behaving in the Coleman-Weinberg mode is considered. The effective potential of the model is computed within the semiclassical approximation in a dimensional regularization scheme. Radiative corrections are shown to introduce certain ..mu..-dependent ultraviolet divergences in the effective potential coming from the Many-Particle theory. The weight of radiative corrections in the dynamics of the system is strongly modified by the charge density.

  10. Colour correction for panoramic imaging

    OpenAIRE

    Tian, Gui Yun; Gledhill, Duke; Taylor, D.

    2002-01-01

    This paper reports the problem of colour distortion in panoramic imaging. Particularly when image mosaicing is used for panoramic imaging, the images are captured under different lighting conditions and viewpoints. The paper analyses several linear approaches for their colour transform and mapping. A new approach of colour histogram based colour correction is provided, which is robust to image capturing conditions such as viewpoints and scaling. The procedure for the colour correction is intr...

  11. Quantum error correction for beginners

    International Nuclear Information System (INIS)

    Quantum error correction (QEC) and fault-tolerant quantum computation represent one of the most vital theoretical aspects of quantum information processing. It was well known from the early developments of this exciting field that the fragility of coherent quantum systems would be a catastrophic obstacle to the development of large-scale quantum computers. The introduction of quantum error correction in 1995 showed that active techniques could be employed to mitigate this fatal problem. However, quantum error correction and fault-tolerant computation is now a much larger field and many new codes, techniques, and methodologies have been developed to implement error correction for large-scale quantum algorithms. In response, we have attempted to summarize the basic aspects of quantum error correction and fault-tolerance, not as a detailed guide, but rather as a basic introduction. The development in this area has been so pronounced that many in the field of quantum information, specifically researchers who are new to quantum information or people focused on the many other important issues in quantum computation, have found it difficult to keep up with the general formalisms and methodologies employed in this area. Rather than introducing these concepts from a rigorous mathematical and computer science framework, we instead examine error correction and fault-tolerance largely through detailed examples, which are more relevant to experimentalists today and in the near future. (review article)

  12. Bone-setting manipulation combined with percutaneous vertebroplasty using polymethylmethacrylate for treatment of osteoporotic thoracolumbar vertebral compression fractures%经皮聚甲基丙烯酸甲酯骨水泥椎体成形结合手法牵引复位治疗骨质疏松性胸腰椎压缩骨折

    Institute of Scientific and Technical Information of China (English)

    周英杰; 赵刚; 李森; 郑怀亮; 赵鹏飞

    2012-01-01

    BACKGROUND: Percutaneous vertebroplasty technique and kyphosis vertebroplasty have been more widely used in clinic,which is considered as the ideal treatment for osteoporotic thoracolumbar vertebral compression fractures.OBJECTIVE: To observe the clinical effects of bone-setting manipulation combined with percutaneous vertebroplasty versuspercutaneous kyphosis vertebroplasty on osteoporotic thoracolumbar vertebral compression fractures.METHODS: Totally 59 cases with osteoporotic thoracolumbar vertebral compression fractures were divided into A and B group: Agroup was treated with bone-setting manipulation combined with percutaneous vertebroplasty, including 38 cases; B groupreceived treatment with percutaneous kyphosis vertebroplasty, including 21 cases. The clinical therapeutic effects of the twogroups were compared by observing the changes in anterior vertebral height, central vertebral height, visual analogue scalescoring, Cobb angle, fees and so on.RESULTS AND CONCLUSION: Anterior vertebral height, central vertebral height, visual analogue scale scoring, Cobb angle inthe two groups were significantly improved after treatment (P 0.05). The fees in the A group were significantly lower than those in the B group (P 0.05).手法结合经皮椎体成形组患者手术费用显著低于经皮后凸椎体成形组(P < 0.05).表明手法牵引复位结合经皮椎体成形治疗骨质疏松性椎体压缩骨折症状、体征均有显著疗效,并能节约手术费用,可以作为老年患者骨质疏松性椎体压缩骨折的首选治疗方法.

  13. GSS pedicle screw fixation combined with two-stage bone cement perfusion for thoracolumbar fractures%GSS椎弓根螺钉内固定并二期伤椎骨水泥灌注治疗胸腰椎骨折

    Institute of Scientific and Technical Information of China (English)

    宋洁富; 李利军; 常峰; 荆志振

    2012-01-01

    Objective To explore the efficacy and safety of surgical treatment of thoracolumbar fractures by GSS pedicle screw fixation combined with two-stage bone cement perfusion. Methods From March 2005 to October 2010, 31 patients with thoracolumbar bursting fractures were treated with posterior GSS pedicle screw fixation. The patients were reviewed by X-ray and CT scan 3-18 months postoperatively. Once "eggshell phenomenon" appeared, bone cement was used in the injured vertebral body before removing the fixators. Injured vertebral height and Cobb' s angle were measured preoperatively, postoperatively and at the final follow-up. Results No leakage of bone cement happened in all the patients. The internal fixators were removed 12-18 months postoperatively. Then the patients were followed up for 1-3 years. Fractured vertebral height and Cobb' s angle were significantly improved after surgery. Conclusion GSS combined with two-stage bone cement perfusion for thoracolumbar fractures can achieve a good therapeutic effect. It can be taken as an attempt at the treatment of thoracolumbar fractures.%目的 探讨GSS椎弓根螺钉内固定结合二期伤椎骨水泥灌注治疗胸腰椎骨折的有效性和安全性.方法 2005年3月~2010年10月共31例胸腰椎爆裂性骨折患者行后路GSS椎弓根螺钉内固定治疗,术后3~18个月根据X线及CT复查情况,出现"蛋壳现象"的患者在取出内固定前行伤椎骨水泥灌注,记录术前、术后及末次随访时的伤椎高度及X线片测量的Cobb角角度.结果 本组患者均未出现骨水泥渗漏,术后12~18个月取出内固定后再随访1~3年.术后伤椎椎体高度及Cobb角与术前相比有明显改善.结论 GSS椎弓根螺钉内固定结合二期伤椎骨水泥灌注治疗胸腰椎骨折可达到良好的治疗效果,可作为治疗胸腰椎骨折的新的尝试.

  14. 42 CFR 460.194 - Corrective action.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Corrective action. 460.194 Section 460.194 Public...) Federal/State Monitoring § 460.194 Corrective action. (a) A PACE organization must take action to correct... corrective actions. (c) Failure to correct deficiencies may result in sanctions or termination, as...

  15. Quantum error correction beyond qubits

    Science.gov (United States)

    Aoki, Takao; Takahashi, Go; Kajiya, Tadashi; Yoshikawa, Jun-Ichi; Braunstein, Samuel L.; van Loock, Peter; Furusawa, Akira

    2009-08-01

    Quantum computation and communication rely on the ability to manipulate quantum states robustly and with high fidelity. To protect fragile quantum-superposition states from corruption through so-called decoherence noise, some form of error correction is needed. Therefore, the discovery of quantum error correction (QEC) was a key step to turn the field of quantum information from an academic curiosity into a developing technology. Here, we present an experimental implementation of a QEC code for quantum information encoded in continuous variables, based on entanglement among nine optical beams. This nine-wave-packet adaptation of Shor's original nine-qubit scheme enables, at least in principle, full quantum error correction against an arbitrary single-beam error.

  16. Fermilab Booster Correction Elements upgrade

    International Nuclear Information System (INIS)

    The Fermilab Booster Correction Element Power Supply System is being upgraded to provide significant improvements in performance and versatility. At the same time these improvements will compliment raising the Booster injection energy from 200 MeV to 400 MeV and will allow increased range of adjustment to tune, chromaticity, closed orbit and harmonic corrections. All correction elements will be capable of ramping to give dynamic orbit, tune and chromaticity control throughout the acceleration cycle. The power supplies are commercial switch mode current sources capable of operating in all four current-voltage quadrants. External secondary feedback loops on the amplifiers have extended the small signal bandwidth to 3 kHz and allow current ramps in excess of 1000 A/sec. Implementation and present status of the upgrade project is described in this paper. (author) 4 refs., 2 figs., 1 tab

  17. Error-Correcting Data Structures

    CERN Document Server

    de Wolf, Ronald

    2008-01-01

    We study data structures in the presence of adversarial noise. We want to encode a given object in a succinct data structure that enables us to efficiently answer specific queries about the object, even if the data structure has been corrupted by a constant fraction of errors. This model is the common generalization of (static) data structures and locally decodable error-correcting codes. The main issue is the tradeoff between the space used by the data structure and the time (number of probes) needed to answer a query about the encoded object. We prove a number of upper and lower bounds on various natural error-correcting data structure problems. In particular, we show that the optimal length of error-correcting data structures for the Membership problem (where we want to store subsets of size s from a universe of size n) is closely related to the optimal length of locally decodable codes for s-bit strings.

  18. Universality of Quantum Gravity Corrections

    CERN Document Server

    Das, Saurya

    2008-01-01

    We show that the existence of a minimum measurable length and the related Generalized Uncertainty Principle (GUP), predicted by theories of Quantum Gravity, influence all quantum Hamiltonians. Thus, they predict quantum gravity corrections to various quantum phenomena. We compute such corrections to the Lamb Shift, the Landau levels and the tunnelling current in a Scanning Tunnelling Microscope (STM). We show that these corrections can be interpreted in two ways: (a) either that they are exceedingly small, beyond the reach of current experiments, or (b) that they predict upper bounds on the quantum gravity parameter in the GUP, compatible with experiments at the electroweak scale. Thus, more accurate measurements in the future would either be able to test these predictions, or further tighten the above bounds and predict an intermediate length scale, between the electroweak and the Planck scale.

  19. Electroweak corrections for LHC processes

    Energy Technology Data Exchange (ETDEWEB)

    Chiesa, Mauro [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Greiner, Nicolas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Gruppe Theorie; Tramontano, Francesco [Napoli Univ. (Italy). Dept. of Physics; Istituto Nazionale di Fisica Nucleare, Naples (Italy)

    2015-07-15

    For the Run 2 of the LHC next-to-leading order electroweak corrections will play an important role. Even though they are typically moderate at the level of total cross sections they can lead to substantial deviations in the shapes of distributions. In particular for new physics searches but also for a precise determination of Standard Model observables their inclusion in the theoretical predictions is mandatory for a reliable estimation of the Standard Model contribution. In this article we review the status and recent developments in electroweak calculations and their automation for LHC processes. We discuss general issues and properties of NLO electroweak corrections and present some examples, including the full calculation of the NLO corrections to the production of a W-boson in association with two jets computed using GoSam interfaced to MadDipole.

  20. Delegation in Correctional Nursing Practice.

    Science.gov (United States)

    Tompkins, Frances

    2016-07-01

    Correctional nurses face daily challenges as a result of their work environment. Common challenges include availability of resources for appropriate care delivery, negotiating with custody staff for access to patients, adherence to scope of practice standards, and working with a varied staffing mix. Professional correctional nurses must consider the educational backgrounds and competency of other nurses and assistive personnel in planning for care delivery. Budgetary constraints and varied staff preparation can be a challenge for the professional nurse. Adequate care planning requires understanding the educational level and competency of licensed and unlicensed staff. Delegation is the process of assessing patient needs and transferring responsibility for care to appropriately educated and competent staff. Correctional nurses can benefit from increased knowledge about delegation. PMID:27302707

  1. Electroweak corrections for LHC processes

    International Nuclear Information System (INIS)

    For the Run 2 of the LHC next-to-leading order electroweak corrections will play an important role. Even though they are typically moderate at the level of total cross sections they can lead to substantial deviations in the shapes of distributions. In particular for new physics searches but also for a precise determination of Standard Model observables their inclusion in the theoretical predictions is mandatory for a reliable estimation of the Standard Model contribution. In this article we review the status and recent developments in electroweak calculations and their automation for LHC processes. We discuss general issues and properties of NLO electroweak corrections and present some examples, including the full calculation of the NLO corrections to the production of a W-boson in association with two jets computed using GoSam interfaced to MadDipole.

  2. Local Correction of Boolean Functions

    CERN Document Server

    Alon, Noga

    2011-01-01

    A Boolean function f over n variables is said to be q-locally correctable if, given a black-box access to a function g which is "close" to an isomorphism f_sigma of f, we can compute f_sigma(x) for any x in Z_2^n with good probability using q queries to g. We observe that any k-junta, that is, any function which depends only on k of its input variables, is O(2^k)-locally correctable. Moreover, we show that there are examples where this is essentially best possible, and locally correcting some k-juntas requires a number of queries which is exponential in k. These examples, however, are far from being typical, and indeed we prove that for almost every k-junta, O(k log k) queries suffice.

  3. Correction

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    <正>The paper"A comparative study on the transplantation of different concentrations of human umbilical mesenchymal cells into diabetic rat"DOI:10.3980/j.issn.2222-3959.2015.02.08 was published in No.2 issue of IJO on 18th April.Jia-Hui Kong,Dan Zheng,Song Chen,Hong-Tao Duan,Yue-Xin Wang,Meng Dong,Jian Song Clinical College of Ophthalmology,Tianjin Medical University,Tianjin Eye Hospital,Tianjin Institute of Ophthalmology,

  4. Correction.

    Science.gov (United States)

    2015-06-01

    Gillon R. Defending the four principles approach as a good basis for good medical practice and therefore for good medical ethics. J Med Ethics 2015;41:111–6. The author misrepresented Beauchamp and Childress when he wrote: ‘My own view (unlike Beauchamp and Childress who explicitly state that they make no such claim ( p. 421)1, is that all moral agents whether or not they are doctors or otherwise involved in healthcare have these prima facie moral obligations; but in the context of answering the question ‘what is it to do good medical ethics ?’ my claim is limited to the ethical obligations of doctors’. The author intended and should have written the following: ‘My own view, unlike Beauchamp and Childress who explicitly state that they make no such claim (p.421)1 is that these four prima facie principles can provide a basic moral framework not only for medical ethics but for ethics in general’. PMID:26002919

  5. Correction

    CERN Multimedia

    2007-01-01

    From left to right: Luis, Carmen, Mario, Christian and José listening to speeches by theorists Alvaro De Rújula and Luis Alvarez-Gaumé (right) at their farewell gathering on 15 May.We unfortunately cut out a part of the "Word of thanks" from the team retiring from Restaurant No. 1. The complete message is published below: Dear friends, You are the true "nucleus" of CERN. Every member of this extraordinary human mosaic will always remain in our affections and in our thoughts. We have all been very touched by your spontaneous generosity. Arrivederci, Mario Au revoir,Christian Hasta Siempre Carmen, José and Luis PS: Lots of love to the theory team and to the hidden organisers. So long!

  6. Decoupling correction system in RHIC

    International Nuclear Information System (INIS)

    A global linear decoupling in the Relativistic Heavy Ion Collider (RHIC) is going to be performed with the three families of skew quadrupoles. The operating horizontal and vertical betatron tunes in the RHIC will be separated by one unit vx=28.19 and vy=29.18. The linear coupling is corrected by minimizing the tune splitting Dn-the off diagonal matrix m. The skew quadrupole correction system is located close to the each of the six interaction regions. A detail study of the system is presented by the use of the TEAPOT accelerator physics code

  7. Brane cosmology with curvature corrections

    International Nuclear Information System (INIS)

    We study the cosmology of the Randall-Sundrum brane-world where the Einstein-Hilbert action is modified by curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a five-dimensional Gauss-Bonnet curvature term. The combined effect of these curvature corrections to the action removes the infinite-density big bang singularity, although the curvature can still diverge for some parameter values. A radiation brane undergoes accelerated expansion near the minimal scale factor, for a range of parameters. This acceleration is driven by the geometric effects, without an inflation field or negative pressures. At late times, conventional cosmology is recovered. (author)

  8. Self-correcting Multigrid Solver

    Energy Technology Data Exchange (ETDEWEB)

    Jerome L.V. Lewandowski

    2004-06-29

    A new multigrid algorithm based on the method of self-correction for the solution of elliptic problems is described. The method exploits information contained in the residual to dynamically modify the source term (right-hand side) of the elliptic problem. It is shown that the self-correcting solver is more efficient at damping the short wavelength modes of the algebraic error than its standard equivalent. When used in conjunction with a multigrid method, the resulting solver displays an improved convergence rate with no additional computational work.

  9. 经皮椎弓根内固定治疗胸腰椎骨折的效果及并发症分析%Therapeutic effects and complications of percutaneous pedicle screw fixation for thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    罗鹏; 徐良丰; 倪文飞; 王向阳; 林焱; 毛方敏; 黄其杉; 徐华梓; 池永龙

    2011-01-01

    Objective To investigate the therapeutic effects and complications of percutaneous pedicle screw fixation for thoracolumbar fractures. Methods From January 2002 to December 2008,103 patients with thoracolumbar fractures were treated with percutaneous pedicle screw fixation, including 75 males and 28 females, the average age was 45.6 years ( range, 18-72 years). All of them were of no neurological deficits. There were 65 cases of traffic injury, 23 cases of fall injury and 15 cases of smashed injury. According to the Denis classification, 64 patients were of compression fractures, and 39 patients of burst fractures. There were 5 cases had fractures in T11, 30 in T12, 42 in L1, 15 in L2, 4 in L3, 3 in L4 ,2 in T11-12, 1 in L1-2, and 1 in L2-3. Radiological examinations, including X-ray and CT examinations, and clinical examinations were carried out to evaluate the therapeutic effects. Results Twenty one patients were lost to follow up, the remaining were followed up from 10 to 48 months with an average of 27.4 months.Before the operation, the vertebral height, the kyphposis angle and the occupation of spinal canal were (54. 5 ±8. 7)%, 16. 4°±2. 9°and 1.2 ± 1. 0, and were improved to (88.6 ±6. 4)%, 11.6°± 2. 7°and 0. 5 ± 0. 6 respectively after the operation. Preoperatively the visual analogue scale and the Oswestry disability index were 8. 0 ± 1.2 and 41.2 ± 9. 3, and were improved to 1.7 ± 1.8 and 6. 7 ± 5.6 postoperatively,respectively. All of these values between pre- and post-operatively were significantly different (P <0. 01 ). Screw misplacement was found in 7 patients, superficial wound infection in 1, screw breakage in 3, screw dislodgment in 2, cement leakage in 5, transient neurological symptoms in 4, and 8 patients with low back pain remained,of which 2 patients required occasional oral analgesics. Bone fusion achieved in all cases. Conclusions The clinical efficacy of percutaneous pedicle screw fixation is similar with conventional open

  10. Application of PMMA Combined with Pedicle Screw in Senile Thoracolumbar Vertebra Fracture%PMMA联合椎弓根螺钉在老年性胸腰椎骨折手术中的应用

    Institute of Scientific and Technical Information of China (English)

    陈大勇; 黄庆华; 李照明; 胡凯; 吴罗根; 周文华; 潘丹; 刘超; 李丰

    2013-01-01

    [目的]探讨用聚甲基丙烯酸甲酯(polymethylmethacrylate,PMMA)骨水泥联合椎弓根螺钉在治疗老年性胸腰椎骨折的早期临床疗效.[方法]回顾性分析2007年6月~2010年6月收治的41例老年性胸腰椎骨折患者采用PMMA联合椎弓根螺钉强化伤椎及椎板减压后外侧植骨融合治疗的临床资料.术前及术后6、12个月随访进行JOA评分,计算手术改善率;行X射线摄片并观察有无并发症发生.[结果]所有患者随访12~21个月,平均13个月.术前JOA评分平均(11±2.36)分,术后半年随访平均为(23±2.06)分,改善率75.0%;末次随访平均(25±2.29分),改善率87.5%,术前、术后JOA评分差异有显著性(P<0.01).置入螺钉过程中未发生因骨水泥渗漏、放热效应及毒性反应引起并发症.1例术后2月发生固定节段下方椎体的螺钉对椎体产生切割现象,但未出现神经根症状.其余患者未出现螺钉松动、断裂和脱落.[结论]PMMA联合椎弓根螺钉内固定能明显增强螺钉的稳定性,是一种治疗老年性胸腰椎骨折安全、可靠的方法.%[Objective]To explore the early clinical efficacy of polymethylmethacrylate(PMMA) bone cement combined with pedicle screw for the treatment of senile thoracolumbar vertebra fracture. [Methods]Clinical data of 41 elderly patients with thoracolumbar vertebra fractures treated with PMMA combined with pedicle screw for strengthening the injury vertebra and lateral grafted bone fusion after laminectomy from June 2007 to June 2010 were analyzed retrospectively. Preoperative and postoperative of JOA score was carried out during 6 and 12 months of follow up. The improvement ratio of the operation was calculated. X-ray radiography was performed. The incidence of the complications was observed. [Results]All patients were followed up for 12 to 21 months(mean 13 months). The mean preoperative JOA score was 11 ± 2. 36. The mean JOA score half a year after the operation was 23 ± 2. 06

  11. 3D计算机导航下经椎弓根骨水泥增强螺钉的应用%Polymethylmethacrylate-augmented thoracolumbar pedicle screw fixation guided by the three-dimensional navigation in osteoporotic patients

    Institute of Scientific and Technical Information of China (English)

    袁强; 张贵林; 吴静晔; 行勇刚; 何达; 孙宇庆; 田伟

    2014-01-01

    Objective To evaluate the safety and efficacy of polymethylmethacrylate (PMMA) -augmented thoracolumbar pedicle screw fixation guided by three-dimensional (3D) navigation in the osteoporotic patients.Methods From January 2010 to January 2012,27 osteoporotic patients with a variety of spinal disorders underwent PMMA-augmented thoracolumbar pedicle screw fixation guided by 3D navigation.They were 3 men and 24 women,aged from 51 to 92 years (average,70.1 years).Their osteoporosis was all serious.PMMA leakage was evaluated intraoperatively and postoperatively.Screw loosening and bone fusion were evaluated radiographically after operation.The Japanese Orthopaedic Association (JOA) scores of the patients were compared between preoperation and one year postoperation.Results Altogether 149 pedicle screws were implanted in the 27 patients.One patient died of postoperative pneumonia and the rest 26 patients were followed up for more than 12 months.No pedicle cortex breach or cement leakage surrounding the pedicle cortex was observed.None of the patients complained of dyspnoea showing evidence of pulmonary embolism or iatrogenic neural injury.No obvious deterioration of related symptoms or functions was observed after operation.The pre-operative JOA score (18.2 ± 2.6 points) was significantly increased (25.1 ± 2.3 points) postoperation (t =16.996,P =0.000),with a mean therapeutic improvement rate of 39.6%.None of the patients showed loosening or displacement of the implants.Lateral X-ray films showed bone fusion in 20 patients (76.9%) at the 12-month follow-up Conclusion PMMA-augmented thoracolumbar pedicle screw fixation guided by 3D navigation is safe and effective for osteoporotic patients with a variety of spinal disorders,leading to favorable outcomes both clinically and radiologically.%目的 评价在3D计算机导航下经椎弓根骨水泥增强胸腰椎椎弓根螺钉内固定术的安全性和有效性. 方法 2010年1月至2012年1月27例不同脊柱疾患

  12. Clinical study of minimally invasive pedicle screw technique combined with percutaneous vertebral body ;in treatment of thoracolumbar burst fracture without neurological symptoms in elderly patients%微创椎弓根螺钉技术联合经皮椎体后凸成形术治疗老年无神经症状胸腰椎爆裂性骨折的临床研究

    Institute of Scientific and Technical Information of China (English)

    张育斌; 杨艳琴; 陈晓生; 杨周生

    2016-01-01

    Objective To compare the clinical efficacy of minimally invasive pedicle screw placement combined with Percutaneous kyphoplasty ( PKP) and PKP in the treatment of elderly patients with no neurological symptoms of thoracolumbar burst fracture .Methods 78 patients with thoracolumbar burst fracture were randomly divided into joint group (group A, n=39) and traditional group (group B, n=39).The clinical and imaging results were evaluated by 2 years follow-up.The clinical results mainly included pain visual analogue scale ( VAS ) , Oswestry Disability Index ( ODI ) .The imaging results included Cobb angle , Secondary fractures , adjacent segment fractures and bone cement leakage .Results There was no statistical difference between the two groups in operation time and duration of hospitalization (P>0.05).Compared pkp group, the combined group has higher bone cement injection ( P<0.05); PKP group had advantages in operation time and intraoperative blood loss (P<0.05).The combined group was superior to the PKP group in the correction of Cobb angle and excellent maintance after operation (P<0.05).Every time after surgery, the combined group were improved significantly compared PKP group in low back pain VAS score and ODI in postoperative follow-up time ( P <0.05).5 patients occurred secondary fractures and 9 patients were found adjacent vertebral fracture after operation in PKP, otherwise, combined group had no fracture .Conclusions Minimally invasive pedicle technique combined with PKP is more effective in correction of kyphotic deformity than pkp .It can quickly relieve postoperative low back pain and improve the quality of life .%目的:对比研究微创椎弓根螺钉置入联合经皮后凸成形术( Percutaneous kyphoplasty ,PKP)与单纯经PKP治疗老年性无神经症状胸腰椎爆裂性骨折,探讨其临床疗效。方法78例老年性胸腰椎爆裂性骨折患者,随机分为联合入路组(A组,n=39)和传统组(B组,n=39

  13. CORRECTIVE ACTION IN CAR MANUFACTURING

    Directory of Open Access Journals (Sweden)

    H. Rohne

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: In this paper the important .issues involved in successfully implementing corrective action systems in quality management are discussed. The work is based on experience in implementing and operating such a system in an automotive manufacturing enterprise in South Africa. The core of a corrective action system is good documentation, supported by a computerised information system. Secondly, a systematic problem solving methodology is essential to resolve the quality related problems identified by the system. In the following paragraphs the general corrective action process is discussed and the elements of a corrective action system are identified, followed by a more detailed discussion of each element. Finally specific results from the application are discussed.

    AFRIKAANSE OPSOMMING: Belangrike oorwegings by die suksesvolle implementering van korrektiewe aksie stelsels in gehaltebestuur word in hierdie artikel bespreek. Die werk is gebaseer op ondervinding in die implementering en bedryf van so 'n stelsel by 'n motorvervaardiger in Suid Afrika. Die kern van 'n korrektiewe aksie stelsel is goeie dokumentering, gesteun deur 'n gerekenariseerde inligtingstelsel. Tweedens is 'n sistematiese probleemoplossings rnetodologie nodig om die gehalte verwante probleme wat die stelsel identifiseer aan te spreek. In die volgende paragrawe word die algemene korrektiewe aksie proses bespreek en die elemente van die korrektiewe aksie stelsel geidentifiseer. Elke element word dan in meer besonderhede bespreek. Ten slotte word spesifieke resultate van die toepassing kortliks behandel.

  14. Quantum Convolutional Error Correction Codes

    OpenAIRE

    Chau, H. F.

    1998-01-01

    I report two general methods to construct quantum convolutional codes for quantum registers with internal $N$ states. Using one of these methods, I construct a quantum convolutional code of rate 1/4 which is able to correct one general quantum error for every eight consecutive quantum registers.

  15. Multilingual text induced spelling correction

    NARCIS (Netherlands)

    Reynaert, M.W.C.

    2004-01-01

    We present TISC, a multilingual, language-independent and context-sensitive spelling checking and correction system designed to facilitate the automatic removal of non-word spelling errors in large corpora. Its lexicon is derived from raw text corpora, without supervision, and contains word unigrams

  16. Interaction and self-correction

    DEFF Research Database (Denmark)

    Satne, Glenda Lucila

    2014-01-01

    acquisition. I then criticize two models that have been dominant in thinking about conceptual competence, the interpretationist and the causalist models. Both fail to meet NC, by failing to account for the abilities involved in conceptual self-correction. I then offer an alternative account of self...

  17. Entropic corrections to Newton's law

    International Nuclear Information System (INIS)

    In this short paper, we calculate separately the generalized uncertainty principle (GUP) and self-gravitational corrections to Newton's gravitational formula. We show that for a complete description of the GUP and self-gravity effects, both the temperature and entropy must be modified. (paper)

  18. 聚焦线圈对管道爬行器X射线管电子束轨迹的纠正作用%Research of Gathering Focus Wire for Rectifying Electron Locus Based on the Focusing Coil for X Ray Tube Electron Beam Trajectory Correction Technology

    Institute of Scientific and Technical Information of China (English)

    张金光; 李冬雪; 马春青

    2012-01-01

    X ray crawler in long distance pipeline girth welding seam X-ray detection is widely used. During the application in the second west to East Gas Pipeline Project of large diameter pipeline, partial target phenomenon was observed for circumferential conical target X ray generator, causing the circumferential X ray intensity inhomogeneity and film densiting difference. To solve this problem, the focusing coil was used in the circumferential conical target X ray generator to correct the trajectory ofeleetron beam. Through the analysis of the experiment, circumferential field intensity reached the purpose of uniform. Application in the follow-up of the long distance pipeline construction in radiographic testing received good results.%X射线管道爬行器在长输管道环焊缝射线检测中得到越来越广泛的应用。其在西气东输二线大口径长输管道的应用中,出现周向锥靶X射线发生器偏靶现象,致使周向X射线场强不均匀,拍摄的底片黑度差异大。对此提出了将聚焦线圈应用在周向锥靶X射线发生器中,以纠正电子柬轨迹的方法。通过分析,试验达到了周向上场强均匀的目的。在后续的长输管道射线检测应用施工中收到良好效果。

  19. Interaction and Self-Correction

    Directory of Open Access Journals (Sweden)

    GlendaLucilaSatne

    2014-07-01

    Full Text Available In this paper I address the question of how to account for the normative dimension involved in conceptual competence in a naturalistic framework. First, I present what I call the Naturalist Challenge (NC, referring to both the phylogenetic and ontogenetic dimensions of conceptual possession and acquisition. I then criticize two models that have been dominant in thinking about conceptual competence, the interpretationist and the causalist models. Both fail to meet NC, by failing to account for the abilities involved in conceptual self-correction. I then offer an alternative account of self-correction that I develop with the help of the interactionist theory of mutual understanding arising from recent developments in Phenomenology and Developmental Psychology.

  20. Motion-corrected Fourier ptychography

    CERN Document Server

    Bian, Liheng; Guo, Kaikai; Suo, Jinli; Yang, Changhuei; Chen, Feng; Dai, Qionghai

    2016-01-01

    Fourier ptychography (FP) is a recently proposed computational imaging technique for high space-bandwidth product imaging. In real setups such as endoscope and transmission electron microscope, the common sample motion largely degrades the FP reconstruction and limits its practicability. In this paper, we propose a novel FP reconstruction method to efficiently correct for unknown sample motion. Specifically, we adaptively update the sample's Fourier spectrum from low spatial-frequency regions towards high spatial-frequency ones, with an additional motion recovery and phase-offset compensation procedure for each sub-spectrum. Benefiting from the phase retrieval redundancy theory, the required large overlap between adjacent sub-spectra offers an accurate guide for successful motion recovery. Experimental results on both simulated data and real captured data show that the proposed method can correct for unknown sample motion with its standard deviation being up to 10% of the field-of-view scale. We have released...

  1. MR image intensity inhomogeneity correction

    International Nuclear Information System (INIS)

    MR technology is one of the best and most reliable ways of studying the brain. Its main drawback is the so-called intensity inhomogeneity or bias field which impairs the visual inspection and the medical proceedings for diagnosis and strongly affects the quantitative image analysis. Noise is yet another artifact in medical images. In order to accurately and effectively restore the original signal, reference is hereof made to filtering, bias correction and quantitative analysis of correction. In this report, two denoising algorithms are used; (i) Basis rotation fields of experts (BRFoE) and (ii) Anisotropic Diffusion (when Gaussian noise, the Perona-Malik and Tukey's biweight functions and the standard deviation of the noise of the input image are considered)

  2. Interaction and self-correction.

    Science.gov (United States)

    Satne, Glenda L

    2014-01-01

    In this paper, I address the question of how to account for the normative dimension involved in conceptual competence in a naturalistic framework. First, I present what I call the naturalist challenge (NC), referring to both the phylogenetic and ontogenetic dimensions of conceptual possession and acquisition. I then criticize two models that have been dominant in thinking about conceptual competence, the interpretationist and the causalist models. Both fail to meet NC, by failing to account for the abilities involved in conceptual self-correction. I then offer an alternative account of self-correction that I develop with the help of the interactionist theory of mutual understanding arising from recent developments in phenomenology and developmental psychology. PMID:25101044

  3. Corrective action program reengineering project

    International Nuclear Information System (INIS)

    A series of similar refueling floor events that occurred during the early 1990s prompted Susquehanna steam electric station (SSES) management to launch a broad-based review of how the Nuclear Department conducts business. This was accomplished through the formation of several improvement initiative teams. Clearly, one of the key areas that benefited from this management initiative was the corrective action program. The corrective action improvement team was charged with taking a comprehensive look at how the Nuclear Department identified and resolved problems. The 10-member team included management and bargaining unit personnel as well as an external management consultant. This paper provides a summary of this self-assessment initiative, including a discussion of the issues identified, opportunities for improvement, and subsequent completed or planned actions

  4. Personalized recommendation with corrected similarity

    International Nuclear Information System (INIS)

    Personalized recommendation has attracted a surge of interdisciplinary research. Especially, similarity-based methods in applications of real recommendation systems have achieved great success. However, the computations of similarities are overestimated or underestimated, in particular because of the defective strategy of unidirectional similarity estimation. In this paper, we solve this drawback by leveraging mutual correction of forward and backward similarity estimations, and propose a new personalized recommendation index, i.e., corrected similarity based inference (CSI). Through extensive experiments on four benchmark datasets, the results show a greater improvement of CSI in comparison with these mainstream baselines. And a detailed analysis is presented to unveil and understand the origin of such difference between CSI and mainstream indices. (paper)

  5. Lightweight Specifications for Parallel Correctness

    OpenAIRE

    Burnim, Jacob Samuels

    2012-01-01

    With the spread of multicore processors, it is increasingly necessaryfor programmers to write parallel software. Yet writing correctparallel software with explicit multithreading remains a difficultundertaking. Though many tools exist to help test, debug, and verifyparallel programs, such tools are often hindered by a lack of anyspecification from the programmer of the intended, correct parallelbehavior of his or her software.In this dissertation, we propose three novel lightweightspecificati...

  6. EPS Young Physicist Prize - CORRECTION

    CERN Document Server

    2009-01-01

    The original text for the article 'Prizes aplenty in Krakow' in Bulletin 30-31 assigned the award of the EPS HEPP Young Physicist Prize to Maurizio Pierini. In fact he shared the prize with Niki Saoulidou of Fermilab, who was rewarded for her contribution to neutrino physics, as the article now correctly indicates. We apologise for not having named Niki Saoulidou in the original article.

  7. Logarithmic Corrections in Directed Percolation

    OpenAIRE

    Janssen, Hans-Karl; Stenull, Olaf

    2003-01-01

    We study directed percolation at the upper critical transverse dimension $d=4$, where critical fluctuations induce logarithmic corrections to the leading (mean-field) behavior. Viewing directed percolation as a kinetic process, we address the following properties of directed percolation clusters: the mass (the number of active sites or particles), the radius of gyration and the survival probability. Using renormalized dynamical field theory, we determine the leading and the next to leading lo...

  8. Fisher Renormalization for Logarithmic Corrections

    OpenAIRE

    Kenna, Ralph; Hsu, Hsiao-Ping; Von Ferber, Christian

    2008-01-01

    For continuous phase transitions characterized by power-law divergences, Fisher renormalization prescribes how to obtain the critical exponents for a system under constraint from their ideal counterparts. In statistical mechanics, such ideal behaviour at phase transitions is frequently modified by multiplicative logarithmic corrections. Here, Fisher renormalization for the exponents of these logarithms is developed in a general manner. As for the leading exponents, Fisher renormalization at t...

  9. The fallacies of QT correction

    OpenAIRE

    Lokhandwala, Yash; Toal, SC

    2003-01-01

    Not to correct QT, but how to, that is the question”. The QT interval is a reflection of the action potential in the cardiac cells. Homogenous or heterogenous changes in the action potential duration lead to alteration of QT interval (in addition to morphological changes of T & U waves) 1. Such changes can be due to change in heart rate & autonomic tone. They can also be markers of abnormal repolarization, depolarization or both as a result of electrolyte disturbances, cardiac diseases, drug...

  10. Surgical correction of "rhinoplastic look"

    OpenAIRE

    Sciuto, S.; BIANCO, N.

    2013-01-01

    SUMMARY A pointed, narrow and exaggeratedly upturned nasal tip and concave dorsal profile can give the nose an unnatural and artificial appearance that is the unmistakable hallmark of plastic surgery. As a result of changes in social attitudes, noses that have evidently been operated on are no longer acceptable and requests are made for correction. While a more natural dorsal profile can be obtained with camouflage grafts of autologous cartilage or alloplastic material (EPTFE), autologous gra...

  11. Sampling Correction in Pedigree Analysis

    OpenAIRE

    Ginsburg Emil; Malkin Ida; Elston Robert C

    2003-01-01

    Usually, a pedigree is sampled and included in the sample that is analyzed after following a predefined non-random sampling design comprising several specific procedures. To obtain a pedigree analysis result free from the bias caused by the sampling procedures, a correction is applied to the pedigree likelihood. The sampling procedures usually considered are: the pedigree ascertainment, determining whether a population unit is to be sampled; the intrafamilial pedigree extension, determining w...

  12. BPM testing, analysis, and correction

    International Nuclear Information System (INIS)

    A general purpose stretched-wire test station has been developed and used for mapping Beam Position Monitors (BPMs). A computer running LabVIEW software controlling a network analyzer and x-y positioning tables operates the station and generates data files. The data is analyzed in Excel and can be used to generate correction tables. Test results from a variety of BPMs used for the Fermilab Main Injector and elsewhere will be presented

  13. BPM testing, analysis, and correction

    International Nuclear Information System (INIS)

    A general purpose stretched-wire test station has been developed and used for mapping Beam Position Monitors (BPMs). A computer running LabVIEW software controlling a network analyzer and x-y positioning tables operates the station and generates data files. The data is analyzed in Excel and can be used to generate correction tables. Test results from a variety of BPMs used for the Fermilab Main Injector and elsewhere will be presented. copyright 1998 American Institute of Physics

  14. Surgical correction of postoperative astigmatism

    OpenAIRE

    Lindstrom Richard

    1990-01-01

    The photokeratoscope has increased the understanding of the aspheric nature of the cornea as well as a better understanding of normal corneal topography. This has significantly affected the development of newer and more predictable models of surgical astigmatic correction. Relaxing incisions effectively flatten the steeper meridian an equivalent amount as they steepen the flatter meridian. The net change in spherical equivalent is, therefore, negligible. Poor predictability is the major limit...

  15. Corrective camouflage in pediatric dermatology.

    Science.gov (United States)

    Tedeschi, Aurora; Dall'Oglio, Federica; Micali, Giuseppe; Schwartz, Robert A; Janniger, Camila K

    2007-02-01

    Many dermatologic diseases, including vitiligo and other pigmentary disorders, vascular malformations, acne, and disfiguring scars from surgery or trauma, can be distressing to pediatric patients and can cause psychological alterations such as depression, loss of self-esteem, deterioration of quality of life, emotional distress, and, in some cases, body dysmorphic disorder. Corrective camouflage can help cover cutaneous unaesthetic disorders using a variety of water-resistant and light to very opaque products that provide effective and natural coverage. These products also can serve as concealers during medical treatment or after surgical procedures before healing is complete. Between May 2001 and July 2003. corrective camouflage was used on 15 children and adolescents (age range, 7-16 years; mean age, 14 years). The majority of patients were girls. Six patients had acne vulgaris; 4 had vitiligo; 2 had Becker nevus; and 1 each had striae distensae, allergic contact dermatitis. and postsurgical scarring. Parents of all patients were satisfied with the cosmetic cover results. We consider corrective makeup to be a well-received and valid adjunctive therapy for use during traditional long-term treatment and as a therapeutic alternative in patients in whom conventional therapy is ineffective. PMID:17388210

  16. Performance of TPC crosstalk correction

    CERN Document Server

    Dydak, F; Krasnoperov, A; Nefedov, Y; Wotschack, J; Zhemchugov, A

    2004-01-01

    The performance of the CERN-Dubna-Milano (CDM) algorithm for TPC crosstalk correction is presented. The algorithm is designed to correct for uni-directional and bi-directional crosstalk, but not for self-crosstalk. It reduces at the 10% level the number of clusters, and the number of pads with a signal above threshold. Despite of dramatic effects in selected channels with complicated crosstalk patterns, the average longitudinal signal shape of a hit, and the average transverse signal shape of a cluster, are little affected by uni-directional and bi-directional crosstalk. The longitudinal signal shape of hits is understood in terms of preamplifier response, longitudinal diffusion, track inclination, and self-crosstalk. The transverse signal shape of clusters is understood in terms of the TPC's pad response function. The CDM crosstalk correction leads to an average charge decrease at the level of 15%, though with significant differences between TPC sectors. On the whole, crosstalk constitutes a relatively benig...

  17. Design and performance test of circumferential crankle guide vane of multistage centrifugal pumps%多级离心泵圆周弯扭式导叶设计及性能试验

    Institute of Scientific and Technical Information of China (English)

    张启华; 徐燕; 施卫东; 高雄发; 马栋棋; 陆伟刚

    2013-01-01

      为开发一种紧凑式多级泵,研究配套的一种圆周弯扭式导叶,其设计思路源自扭曲离心叶轮设计方法。通过固定导叶顶端曲线,将导叶底端曲线沿圆周方向向前延伸,形成弯扭式曲面。该导叶结构具有2个优点。首先,导叶底端沿圆周向前延伸后保证了较大的喉部进水区域面积。其次,利用底端向前延伸的部分与下一个叶片的圆柱部分自然形成扩压器状的过流通道,增强了导叶的扩压能力。在二次开发技术的基础上开发出该结构的水力设计系统。利用该系统设计出多组方案,同时利用CFD计算分析,经过不同方案的比较,最终获得了优化的导叶模型,并通过样机试验验证该模型具有较好的水力性能。该设计方法将有利于多级泵的节能,同时该方法也为紧凑式多级泵开发提供了有益的参考。%To design compact multistage centrifugal pumps, a circumferential crankle guide vane was proposed to match their compact structure. The basic design principle originated from the twisted centrifugal impeller design method and the design method of this guide vane was investigated systematically. By fixing the top curve of the guide vane and extending the bottom curve forward along a circumferential direction, a crankle surface is shaped. This design method has two merits. Firstly, the bottom curve of the first guide vane is extended circumferentially forward to guarantee a large throat flow area. And secondly, a diffuser-like passage is naturally formed by the extended surface and the cylindrical surface of the next blade, which enhances its pressure recovery ability. In addition, the blade surface is divided into two segmented parts, that is, a full twisted surface and a cylindrical surface, thus the casting and molding of the guide vane is more convenient. To reduce the design cycle of the guide vane, a hydraulic design system of the circumferential crankle

  18. 超声衍射时差法检测汽水管道环焊缝根部腐蚀减薄%Time-of-Flight-Diffraction Testing of Steam and Water Piping Circumferential Weld Roots Local Wall-thinning

    Institute of Scientific and Technical Information of China (English)

    钟志民; 张维; 汪明辉

    2016-01-01

    The field feedbacks show that the industry should pay more attention to secondary loop steam and water piping circumferential weld root flow-accelerated corrosion(FAC)in Nuclear Power Plants from field feedbacks. Without effective inspection and supervision, it will lead to serious consequences such as high energy pipe leakage or rupture. The weld root Ultrasonic Time of Flight Diffraction(TOFD) inspection principle and testing results were discussed in detail. It was shown that TOFD can be applied to inspect local wall-thinning ,caused by flow-accelerated corrosion, at circumferential weld roots of secondary loop steam & water piping in nuclear power plants.%工程经验反馈表明,过往关注较少的核电站二回路汽水管道环焊缝根部由流动加速腐蚀引起的局部减薄现象应引起业界重视,如不进行有效的检测和监督,也会导致高能管道泄漏或破裂.本文重点探讨了核电站二回路汽水管道环焊缝根部局部减薄超声衍射时差法的检测原理、试验情况.结果表明,超声衍射时差法可用于检测流动加速腐蚀引起的汽水管道环焊缝根部局部减薄.

  19. 周向导波电磁超声探头(EMAT)设计与优化%Design and Optimization of Electromagnetic Acoustic Transducer (EMAT) for Guided Circumferential Wave

    Institute of Scientific and Technical Information of China (English)

    沙高峰; 蔡桂喜

    2012-01-01

    To inspect oil and gas pipelines by using SHO mode guided circumferential ultrasonic wave,a novel electromagnetic acoustic transducer (EMAT) for guided circumferential wave was designed. The EMAT has two structural features,a carbon steel sheet is on top of all the magnets and small nonmagnetic blocks are placed between adjacent magnets. To improve its transduction efficiency, ANSYS software was used to optimize some geometric parameters of EMAT. The optimal result is the carbon steel sheet should be thicker than 1 mm, and the wire spacing of the coil should be as small as possible. Experiments on a tube 200 mm in OD and 4 mm in wall thickness indicate that the EMAT optimized can excite the SHO mode guided wave effectively.%为了利用SH0模超声周向导波检测油气管道纵向裂纹,提出了一种新的周向导波电磁超声探头(EMAT)结构设计,其结构特点是磁铁顶部放置碳钢片,相邻磁铁之间放置非磁性材料片.为了提高周向导波EMAT的换能效率,采用ANSYS仿真对其结构参数进行了优化.优化的结果为:磁铁顶部应放置厚度大于1mm的碳钢片,线圈中导线间距要尽量小.在直径200 mm壁厚、4mm的管材上进行实验,结果表明,优化设计后的探头能有效地激励出周向SH0导波.

  20. Correction to Moliere's formula for multiple scattering

    International Nuclear Information System (INIS)

    The semiclassical correction to Moliere's formula for multiple scattering is derived. The consideration is based on the scattering amplitude obtained with the first semiclassical correction taken into account for an arbitrary localized but not spherically symmetric potential. Unlike the leading term, the correction to Moliere's formula contains the target density n and thickness L not only in the combination nL (areal density). Therefore, this correction can be referred to as the bulk density correction. It turns out that the bulk density correction is small even for high density. This result explains the wide range of applicability of Moliere's formula

  1. Correction of gene expression data

    DEFF Research Database (Denmark)

    Darbani Shirvanehdeh, Behrooz; Stewart, C. Neal, Jr.; Noeparvar, Shahin;

    2014-01-01

    This report investigates for the first time the potential inter-treatment bias source of cell number for gene expression studies. Cell-number bias can affect gene expression analysis when comparing samples with unequal total cellular RNA content or with different RNA extraction efficiencies. For...... maximal reliability of analysis, therefore, comparisons should be performed at the cellular level. This could be accomplished using an appropriate correction method that can detect and remove the inter-treatment bias for cell-number. Based on inter-treatment variations of reference genes, we introduce an...

  2. Correct Linearization of Einstein's Equations

    Directory of Open Access Journals (Sweden)

    Rabounski D.

    2006-06-01

    Full Text Available Regularly Einstein's equations can be reduced to a wave form (linearly dependent from the second derivatives of the space metric in the absence of gravitation, the space rotation and Christoffel's symbols. As shown here, the origin of the problem is that one uses the general covariant theory of measurement. Here the wave form of Einstein's equations is obtained in the terms of Zelmanov's chronometric invariants (physically observable projections on the observer's time line and spatial section. The obtained equations depend on solely the second derivatives even if gravitation, the space rotation and Christoffel's symbols. The correct linearization proves: the Einstein equations are completely compatible with weak waves of the metric.

  3. Holographic Thermalization with Weyl Corrections

    CERN Document Server

    Dey, Anshuman; Sarkar, Tapobrata

    2015-01-01

    We consider holographic thermalization in the presence of a Weyl correction in five dimensional AdS space. We numerically analyze the time dependence of the two point correlation functions and the expectation values of rectangular Wilson loops in the boundary field theory. The subtle interplay between the Weyl coupling constant and the chemical potential is studied in detail. An outcome of our analysis is the appearance of a swallow tail behaviour in the thermalization curve, and we give evidence that this might indicate distinct physical situations relating to different length scales in the problem.

  4. Fratura toracolombar do tipo explosão: correlação entre a cifose residual e função após o tratamento cirúrgico Thoracolumbar burst fracture: correlation between kyphosis and function after surgical treatment

    Directory of Open Access Journals (Sweden)

    Daniel Akira Sadatsune

    2012-01-01

    Full Text Available OBJETIVO: Avaliar a correlação entre a cifose pós-traumática em portadores de fratura toracolombar explosão, submetidos a tratamento cirúrgico e resultado funcional do tratamento. MÉTODOS: Realizado estudo retrospectivo em 27 pacientes com fratura toracolombar do tipo A3 da classificação de Denis e Margerl, que preencheram os critérios de inclusão para esta amostra e foram submetidos a tratamento cirúrgico com um tempo mínimo de acompanhamento de seis meses. A média de idade foi de 46,96, variando entre 16 e 73 anos. O resultado do tratamento foi avaliado com base na aplicação do questionário de qualidade de vida Short-Form 36 (SF-36, nas escalas de dor e trabalho de Denis e na escala visual de dor. A cifose foi medida conforme o método de Cobb ao final do seguimento. RESULTADOS: Não foi observada correlação entre a cifose residual e o SF-36, a escala de Denis para dor e trabalho e a escala visual de dor (p > 0,05. CONCLUSÃO: Não há correlação entre o resultado clínico final e a cifose residual em pacientes com fraturas toracolombares do tipo explosão submetidos a tratamento cirúrgico.OBJECTIVE: To assess the correlation between post-traumatic kyphosis in patients with thoracolumbar burst fractures undergoing surgical treatment and the functional result from treatment. METHODS: A retrospective study was conducted on 27 patients with thoracolumbar fractures of type 3 in Denis and Margerl's classification who met the inclusion criteria for this sample and underwent surgical treatment with a minimum follow-up of six months. The patients' mean age was 46.96, with a range from 16 to 73 years. The treatment outcome was evaluated based on applying the short-form 36 (SF-36 quality of life questionnaire, Denis pain and work scale and visual pain scale. The kyphosis was measured according to the Cobb method at the end of the follow-up. RESULTS: The residual kyphosis was found not to correlate with the SF-36, Denis pain and

  5. Clinical effect of posterior pedicle screw ifxation and bone graft surgery for thoracolumbar spine fracture%脊柱胸腰段骨折行后路椎弓根螺钉固定联合植骨手术的临床效果

    Institute of Scientific and Technical Information of China (English)

    官丙刚; 韩燕; 邓树才

    2016-01-01

    Objective to observe and analyze clinical effect of posterior pedicle screw fixation and bone graft surgery for thoracolumbar spine fracture.Methods choose 64 cases thoracolumbar fracture patients treated in our hospital from May 2013 to October 2015 as research objects and randomly divide them into control and observation group, 32 cases in each. Observation group was treated with posterior pedicle screw fixation and bone graft surgery, and control group with combined lateral bone grafting. Compare treatment effect of two groups.Results after operation, VAS scores, Worter index, Cobb angle and complication incidence of observation group were significantly better than control group, difference showed statistical significance (P<0.05).Conclusion posterior pedicle screw fixation and bone graft surgery has significant clinical effect for thoracolumbar spine fracture, which can effectively improve patient’s life quality,and is worthy of clinical application and promotion.%目的:观察分析脊柱胸腰段骨折行后路椎弓根螺钉固定联合植骨手术的临床效果。方法选取我院2013年5月至2015年10月收治的64例脊柱胸腰段骨折患者为研究对象,随机分为对照组与观察组,各32例。观察组行后路椎弓根螺钉固定联合植骨术治疗,对照组行联合外侧植骨治疗,比较两组治疗效果。结果术后,观察组VAS评分、Worter指数、Cobb角及并发症发生率均显著优于对照组,(P<0.05)差异具有统计学意义。结论对脊柱胸腰段骨折患者行后路椎弓根螺钉固定联合植骨术的临床疗效显著,可有效提高患者生活质量,值得临床广泛应用及推广。

  6. Correction of electric standing waves

    Science.gov (United States)

    Kester, Do; Avruch, Ian; Teyssier, David

    2014-12-01

    Electric Standing Waves (ESW) appear in some frequency bands of HIFI, a heterodyne spectrometer aboard the Herschel Space Observatory. ESWs consist of about 10 irregular ripples added to a continuum contribution. They distort the spectra and should be removed. ESWs change so rapidly that the standard ways to mitigate them, do not work. We have built a catalog of thousands of spectra taken on empty sky that contain only the ESW contribution. All ESWs seem to belong to a limited number of multiplicative families. To find representative members of the families we modelled them as splines and chose one representative template model for each family based on Bayesian evidence. The resulting set of models is our catalog of possible ESW templates. To correct a spectrum taken on an astronomical source, we select the template from the catalog that fits with the highest Bayesian evidence and subtract it. This has to be done in the possible presence of spectral lines and of a true astronomical continuuum. Both the true lines and continuum should be unaffected by the procedure. To exclude the lines we use a robustly weighted variety of the (gaussian) likelihood. Ideally the correction should be part of the pipeline with which all HIFI observations have to be processed. This requires a procedure having no failures, no interaction, and limited CPU usage.

  7. Bone cement implantation during percutaneous vertebroplasty for the treatment of thoracolumbar vertebral fractures%骨水泥植入经皮椎体成形治疗胸腰椎体骨折

    Institute of Scientific and Technical Information of China (English)

    柳申鹏; 刘中何; 赵斌; 徐海斌

    2012-01-01

    BACKGROUND: In recent years, percutaneous vertebroplasty as a safe and effective minimally invasive surgery has been widely used in the treatment of osteoporotic compression fractures and vertebral tumor-induced osteolytic bone destruction, and has obtained satisfactory results. OBJECTIVE: To explore the correlation between bone cement and the curative effect of thoracolumbar vertebral fractures by percutaneous vertebroplasty. METHODS: The VIP database and PubMed database were used to search the articles related to the clinical research of percutaneous vertebroplasty and bone cement implantation with the key words of "pereutaneous vertebroplasty, PVP, thoracic vertebra, lumbar vertebra, vertebral fracture, bone cement" in Chinese and English, respectively. A total of 22 articles were included to review. Forty cases (56 vertabral bodies) with the pain induced by thoracolumbar vertebral fractures were selected from the Department of Orthopedics, the First Affiliated Hospital of Xinxiang Medical University for the clinical validation. The percutaneous vertebroplasty was completed under the guidance of C-arm X-ray machine. The improvement of pain was observed after surgery, and the occurrence of the complications was analyzed. RESULTS AND CONCLUSION: At present, the commonly used pereutaneous vertebroplasty bone cement includes polymethyl methacrylate bone cement, calcium phosphate cement and calcium sulfate bone cement. The volume and the composition of bone cement required for the sufficient stability of fracture healing and prevention of pain is remains unclear, but we should try to use small doses of bone cement and make the bone cement evenly distributed. Meanwhile, we should select an appropriate injection method based on different situations of the vertebra in order to prevent the leakage of bone cement and new vertebral fractures. The clinical validation results show that percutaneous vertebroplasty is an effective analgesic method, and postoperative follow

  8. Application of bone cement in the posterior approach surgical treatment for metastatic tumor of the thoracolumbar spine%胸腰椎转移瘤后路手术中骨水泥的应用

    Institute of Scientific and Technical Information of China (English)

    毛宁方; 朱晓东; 张晔; 吴云刚; 白玉树; 李明; 石志才

    2009-01-01

    目的:探讨骨水泥在胸腰椎转移瘤后路手术中的应用价值.方法:2004年3月~21208年12月,后方入路手术治疗胸腰椎转移性肿瘤患者26例,原发肿瘤:肺癌9例,乳腺癌7例,肝癌4例,前列腺癌2例,肾癌1例,来源不明3例.病灶累及单节段17例,两节段9例.23例伴不同程度的腰背部疼痛:神经功能按Frankel分级:B级6例,C级7例,D级11例,E级2例.术中采用骨水泥联合椎弓根螺钉重建脊柱稳定性,其中骨水泥填塞15个椎体,骨水泥前方重建9个椎体,骨水泥椎体成形11个椎体,10例合并骨质疏松患者同时采用骨水泥加强椎弓根钉道.结果:术中未发现骨水泥放热效应引起的神经功能受损.24例患者获得完整随访,随访时间3~42个月,平均18.2个月,23例术前有不同程度腰背疼痛者术后疼痛消失6例,缓解14例;术前伴神经功能障碍者17例(77%)获得神经功能改善.随访期间未发现骨水泥下沉、椎节塌陷及向前成角.1例骨水泥填塞术后3个月骨水泥界面出现松动,但未引起神经压迫症状.15例随访期间死亡.结论:在胸腰椎转移性肿瘤后路手术治疗中,根据患者的全身情况、预期寿命、肿瘤类型、转移椎体位置及骨密度,充分利用骨水泥独特的理化特性,进行多种不同方式的应用,可以减小手术创伤,提高生存质量.%Objective:To explore the clinic effects of the bone cement utilized in the posterior approach surgical treatment of the thoracic and lumbar spinal metastatic tumor.Method:26 patients with the thoracolumbar spinal metastatic tumors who underwent posterior approach surgical treatment from March 2004 to December 2008 were reviewed retrospectively.There were lung carcinoma in 9 cases, breast carcinoma in 7 cases, hepato-carcinoma in 4 cases,prostate carcinoma in 2 cages,kidney carcinoma in 1 case,and 3 cases with unknown origin.Tumor involved single vertebral body in 17 cases,two vertebral bodies in 9 cases.23

  9. Implantation material selection based on bone densitometry for thoracolumbar vertebral compression fracture treatment%骨密度测量与胸腰椎压缩骨折植入物治疗方式的选择

    Institute of Scientific and Technical Information of China (English)

    刘振武; 颜继英; 刘法敬; 刘利

    2011-01-01

    BACKGROUND: During the course of percutaneous kyphoplasty (PKP), polymethyl methacrylate is injected into vertebrae andattaches in the broken ends of fractured bone, which hinders fibrous tissue regeneration and new bone formation besides ofinstantly stabilized fracture. In the long run, I t is adverse to the healing of non-osteoporosis fracture.OBJECTIVE: To analysis the guidance of bone densitometry for choosing modus operandi and implantation material in thetreatment of thoracolumbar vertebral compression fractureMETHODS: Totally 65 patients with single-segment of thoracolumbar compression fracture were divided into two groupsaccording to the L2-4 bone mineral density: osteoporosis group were treated with PKP and non-osteoporosis group were treatedwith pedicle screw implant and fixation treatment.RESULTS AND CONCLUSION: There were 3 cases of paravertebral cement leakage in the osteoporosis group and 1 case ofwound infection in the non-osteoporosis group. The postoperative follow-up ranged 20-28 months. Two patients occurred adjacentvertebral fracture in the osteoporosis group, but no one had vertebral height lost and kyphosis angle increased after fixationremoved in the non-osteoporosis group. Operation time, blood loss and the visual analogue scale score in the osteoporosis groupwere lower as compared with non-osteoporosis group (P < 0.05). Compared with preoperation, both groups had statisticalsignificance in vertebral height restoration and kyphosis angle rectification (P < 0.05), but the non-osteoporosis group was morestriking in above indexes (P < 0.05). Both PKP and pedicle screw implant fixation treatment are common methods in treatingthoracolumbar vertebral compression fracture of mid-aged patients, and a more significant clinical effect will be received if takesan appropriate operation according to the osteoporosis degree.%背景:经皮椎体后凸成形治疗中聚甲基丙烯酸甲酯附着在骨折断端,尽管起到了即刻固定骨折的作用,

  10. 新型胸腰椎前路内固定系统的设计与生物力学研究%Design and biomechanical study of a new system for anterior thoracolumbar internal fixation

    Institute of Scientific and Technical Information of China (English)

    丁真奇; 胡生庭; 康两期; 翟文亮; 梁勃威; 沙漠

    2013-01-01

    Objective To evaluate the biomechanical performance of a self-designed new complex rod-plate system (D-rod) for anterior thoracolumbar internal fixation.Methods Eighteen specimens of pig spine (T12-L3) were allocated to 3 groups (n=6 each) by random digits table.Bone mineral density (BMD) in each group was measured and compared.Models of L1 bust fracture were created in each group,titanium mesh cage was implanted for vertebral reconstruction,and then fixed respectively with D-rod system (group A),Z-plate system (group B) and Ventrofix system (group C).Range of motion on relative angular displacement in T12-L2 under 6.0 Nm pure moment of couple was measured for specimens in each group at six motions (anterior flexion,posterior extension,left lateral bending,right lateral bending,left axial rotation and right axial rotation).Stability was compared among 3 groups.Results The BMD for groups A,B and C was respectively(1.265±0.073) g/cm2,(1.126±0.082) g/cm2 and (1.403±0.095) g/cm2,with no significant between-group difference(P>0.05).D-rod and Ventrofix yielded significantly greater stability than Z-plate at anterior flexion,posterior extension,left and right lateral bending (all P<0.05).D-rod and Z-plate yielded significantly greater stability than Ventrofix at axial rotations (both P<0.05).Conclusions The selfdesigned D-rod system,as a locking system with low profile and greater adjustability,can result in adequate stability for anterior thoracolumbar reconstruction.%目的 设计一种新型板棒复合胸腰椎前路内固定装置(D-rod),并评价其生物力学效果.方法 18具家猪脊柱(T12~L3)标本按随机数字表法分为D-rod组、Z-plate组和Ventrofix组,每组6具,测量3组标本的骨密度并进行比较.制作3组标本L1爆裂骨折模型,钛笼植入重建椎体并分别采用D-rod系统、Z-plate系统和Ventrofix系统内固定.对标本施加6.0 Nm纯力偶矩,依次测试3组标本前屈、后伸、左侧弯、右侧弯、左

  11. Network error correction with unequal link capacities

    OpenAIRE

    Kim, Sukwon; Ho, Tracey; Effros, Michelle; Avestimehr, Amir Salman

    2010-01-01

    We study network error correction with unequal link capacities. Previous results on network error correction assume unit link capacities. We consider network error correction codes that can correct arbitrary errors occurring on up to z links. We find the capacity of a network consisting of parallel links, and a generalized Singleton outer bound for any arbitrary network. We show by example that linear coding is insufficient for achieving capacity in general. In our exampl...

  12. Correction magnet power supplies for APS machine

    International Nuclear Information System (INIS)

    A number of correction magnets are required for the advanced photon source (APS) machine to correct the beam. There are five kinds of correction magnets for the storage ring, two for the injector synchrotron, and two for the positron accumulator ring (PAR). Table I shoes a summary of the correction magnet power supplies for the APS machine. For the storage ring, the displacement of the quadrupole magnets due to the low frequency vibration below 25 Hz has the most significant effect on the stability of the positron closed orbit. The primary external source of the low frequency vibration is the ground motion of approximately 20 μm amplitude, with frequency components concentrated below 10 Hz. These low frequency vibrations can be corrected by using the correction magnets, whose field strengths are controlled individually through the feedback loop comprising the beam position monitoring system. The correction field require could be either positive or negative. Thus for all the correction magnets, bipolar power supplies (BPSs) are required to produce both polarities of correction fields. Three different types of BPS are used for all the correction magnets. Type I BPSs cover all the correction magnets for the storage ring, except for the trim dipoles. The maximum output current of the Type I BPS is 140 Adc. A Type II BPS powers a trim dipole, and its maximum output current is 60 Adc. The injector synchrotron and PAR correction magnets are powered form Type III BPSs, whose maximum output current is 25 Adc

  13. 75 FR 2510 - Procurement List; Corrections

    Science.gov (United States)

    2010-01-15

    ... services on January 11, 2010 (75 FR 1354-1355). The correct date that comments should be received is... FR 1355-1356). The correct effective date should be February 11, 2010. ADDRESSES: Committee for... PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List; Corrections AGENCY: Committee for...

  14. 45 CFR 1225.19 - Corrective action.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Corrective action. 1225.19 Section 1225.19 Public... Corrective action. (a) When discrimination is found, Peace Corps or ACTION must take appropriate action to... corrective action to the agent and other class members in accordance with § 1225.10 of this part. (b)...

  15. 40 CFR 192.04 - Corrective action.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Corrective action. 192.04 Section 192... Corrective action. If the groundwater concentration limits established for disposal sites under provisions of § 192.02(c) are found or projected to be exceeded, a corrective action program shall be placed...

  16. 45 CFR 1225.10 - Corrective action.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Corrective action. 1225.10 Section 1225.10 Public... Corrective action. When it has been determined by Final Agency Decision that the aggrieved party has been subjected to illegal discrimination, the following corrective actions may be taken: (a) Selection as...

  17. 10 CFR 72.172 - Corrective action.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Corrective action. 72.172 Section 72.172 Energy NUCLEAR... Corrective action. The licensee, applicant for a license, certificate holder, and applicant for a CoC shall... that the cause of the condition is determined and corrective action is taken to preclude...

  18. 42 CFR 431.246 - Corrective action.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Corrective action. 431.246 Section 431.246 Public... Recipients Procedures § 431.246 Corrective action. The agency must promptly make corrective payments, retroactive to the date an incorrect action was taken, and, if appropriate, provide for admission...

  19. 40 CFR 35.3170 - Corrective action.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Corrective action. 35.3170 Section 35... STATE AND LOCAL ASSISTANCE State Water Pollution Control Revolving Funds § 35.3170 Corrective action. (a... will notify the State of such noncompliance and prescribe the necessary corrective action. Failure...

  20. 34 CFR 200.42 - Corrective action.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Corrective action. 200.42 Section 200.42 Education... Programs Operated by Local Educational Agencies Lea and School Improvement § 200.42 Corrective action. (a) Definition. “Corrective action” means action by an LEA that— (1) Substantially and directly responds to—...

  1. 10 CFR 71.133 - Corrective action.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Corrective action. 71.133 Section 71.133 Energy NUCLEAR....133 Corrective action. The licensee, certificate holder, and applicant for a CoC shall establish... determined and corrective action taken to preclude repetition. The identification of the...

  2. Physics of the Power Corrections in QCD

    CERN Document Server

    Gubarev, F V; Zakharov, V I

    1999-01-01

    We review the physics of the power corrections to the parton model. In the first part, we consider the power corrections which characterize the infrared sensitivity of Feynman graphs when the contribution of short distances dominates. The second part is devoted to the hypothetical power corrections associated with nonperturbative effects at small distances.

  3. 不同后路环状融合术治疗老年人腰椎不稳症的临床疗效%The therapeutic effect of different posterior circumferential fusion on lumbar instability in aged patients

    Institute of Scientific and Technical Information of China (English)

    陈柏龄; 黎艺强; 刘少喻; 李佛保; 梁春祥

    2011-01-01

    目的 评价传统后路环状融合术和简化后路环状融合术治疗老年人腰椎不稳症的临床疗效。 方法 2005年开始使用椎弓根钉系统辅助后路环状融合术治疗60岁及以上单节段腰椎不稳症80例,58例进行2年以上随访,其中28例采用了横突间植骨的传统后路环状融合术(PLIF+PLF,A组),30例采用不进行横突间植骨的简化后路环状融合术(PLIF+FF,B组)。术前和术后1、3、6、12、24个月应用X线评价腰椎状态及植骨融合情况,并应用视觉疼痛评分(VAS)和()swestry功能障碍指数(ODI)评价患者腰腿疼痛程度及生活功能情况。 结果 A组手术时间(185.3±56.6)min,术中出血量(376.3±92.9)ml;B组手术时间(146.4±46.3)min,术中出血量(234.3±64.5)ml,两组比较手术时间和出血量差异均有统计学意义(t= 12.37和37.49,均P<0.01)。A组28例中27例获骨性融合,融合率96.4%,B组30例中28例获骨性融合,融合率93.3%,两组骨融合率差异无统计学意义(x2=0.004,P>0.05)。两组患者术后腰、腿痛VAS评分及ODI均较术前明显改善。术后1个月和3个月,B组腰痛VAS评分比A组显著降低(t=3.178和2.158,P<0.05),其余3个时间点两组之间腰痛VAS差异无统计学意义(均P>0.05)。术后5个时间点A、B两组间腿痛VAS评分及ODI值均无统计学差别(均P>0.05)。 结论对于具有手术指征的老年腰椎不稳症患者,采用不进行横突间植骨融合的简化后路环状融合术与传统的后路环状融合术相比,可获得相似的融合率和满意的临床疗效,且创伤显著减少,是值得推荐的一种手术方式。%Objective To compare the clinical effect of posterior circumferential fusion with versus without intertransverse process fusion on lumbar instability in aged patients. Methods The elderly with lumbar instability were treated with the posterior instrumented circumferential fusion technique in 80

  4. Correct Linearization of Einstein's Equations

    Directory of Open Access Journals (Sweden)

    Rabounski D.

    2006-04-01

    Full Text Available Routinely, Einstein’s equations are be reduced to a wave form (linearly independent of the second derivatives of the space metric in the absence of gravitation, the space rotation and Christoffel’s symbols. As shown herein, the origin of the problem is the use of the general covariant theory of measurement. Herein the wave form of Einstein’s equations is obtained in terms of Zelmanov’s chronometric invariants (physically observable projections on the observer’s time line and spatial section. The equations so obtained depend solely upon the second derivatives, even for gravitation, the space rotation and Christoffel’s symbols. The correct linearization proves that the Einstein equations are completely compatible with weak waves of the metric.

  5. Pileup correction of microdosimetric spectra

    CERN Document Server

    Langen, K M; Lennox, A J; Kroc, T K; De Luca, P M

    2002-01-01

    Microdosimetric spectra were measured at the Fermilab neutron therapy facility using low pressure proportional counters operated in pulse mode. The neutron beam has a very low duty cycle (<0.1%) and consequently a high instantaneous dose rate which causes distortions of the microdosimetric spectra due to pulse pileup. The determination of undistorted spectra at this facility necessitated (i) the modified operation of the proton accelerator to reduce the instantaneous dose rate and (ii) the establishment of a computational procedure to correct the measured spectra for remaining pileup distortions. In support of the latter effort, two different pileup simulation algorithms using analytical and Monte-Carlo-based approaches were developed. While the analytical algorithm allows a detailed analysis of pileup processes it only treats two-pulse and three-pulse pileup and its validity is hence restricted. A Monte-Carlo-based pileup algorithm was developed that inherently treats all degrees of pileup. This algorithm...

  6. A Quantum Correction To Chaos

    CERN Document Server

    Fitzpatrick, A Liam

    2016-01-01

    We use results on Virasoro conformal blocks to study chaotic dynamics in CFT$_2$ at large central charge c. The Lyapunov exponent $\\lambda_L$, which is a diagnostic for the early onset of chaos, receives $1/c$ corrections that may be interpreted as $\\lambda_L = \\frac{2 \\pi}{\\beta} \\left( 1 + \\frac{12}{c} \\right)$. However, out of time order correlators receive other equally important $1/c$ suppressed contributions that do not have such a simple interpretation. We revisit the proof of a bound on $\\lambda_L$ that emerges at large $c$, focusing on CFT$_2$ and explaining why our results do not conflict with the analysis leading to the bound. We also comment on relationships between chaos, scattering, causality, and bulk locality.

  7. Radiative corrections in bumblebee electrodynamics

    Directory of Open Access Journals (Sweden)

    R.V. Maluf

    2015-10-01

    Full Text Available We investigate some quantum features of the bumblebee electrodynamics in flat spacetimes. The bumblebee field is a vector field that leads to a spontaneous Lorentz symmetry breaking. For a smooth quadratic potential, the massless excitation (Nambu–Goldstone boson can be identified as the photon, transversal to the vacuum expectation value of the bumblebee field. Besides, there is a massive excitation associated with the longitudinal mode and whose presence leads to instability in the spectrum of the theory. By using the principal-value prescription, we show that no one-loop radiative corrections to the mass term is generated. Moreover, the bumblebee self-energy is not transverse, showing that the propagation of the longitudinal mode cannot be excluded from the effective theory.

  8. Self-interaction correction to GW approximation

    International Nuclear Information System (INIS)

    A general approach to correct the self-interaction error in GW approximation is proposed, and proved to be exact in the one-electron limit. The correction is expressed by vertex corrections to both the self-energy and the polarization, and the formulation can be shown to be equivalent to the Schneider-Taylor-Yaris approximation of many-body scattering theory. The suitability of this correction in many-electron systems is also discussed. Numerical calculations of the two-electron two-site Hubbard model are performed to illustrate the effects of the self-interaction correction on many-electron systems.

  9. Clinical surgical methods of patients with old thoracolumbar spine fracture with spinal cord injury%陈旧性胸腰椎脊柱骨折伴脊髓损伤患者的临床手术方法分析

    Institute of Scientific and Technical Information of China (English)

    薛健康; 谈中文; 张军

    2013-01-01

    目的 为了进一步探讨陈旧性胸腰椎脊柱骨折伴脊髓损伤患者采用前路减压植骨内固定治疗的临床实际疗效.方法 选取该院2005年11月-2011年11月间入院治疗的40例陈旧性胸腰椎脊柱骨折伴脊髓损伤患者为研究对象,针对患者的相关临床资料进行了回顾性分析,针对患者采用前路减压植骨内固定治疗前后的相关临床指标进行了比较分析.结果 该组患者实施前路减压植骨内固定治疗方法后Frankel分级情况得到了显著的改善,在椎体高度(后缘)、椎管狭窄程度、Cobb角等三项临床指标比较结果上看,实施手术后患者三项指标均得到了有效的改善,且治疗前后比较,P均<0.05,差异具有统计学意义.结论 在临床治疗陈旧性胸腰椎脊柱骨折伴脊髓损伤过程中,采用前路减压植骨内固定治疗方法的临床治疗效果显著,是治疗陈旧性胸腰椎脊柱骨折伴脊髓损伤的安全可靠选择.%Objective To further explore the clinical efficacy of anterior decompression and bone grafting and internal fixation in the treatment of patients with old thoracolumbar spine fracture with spinal cord injury . Methods 40 cases of old thoracolumbar spine frac -hires with spinal cord injury hospitalized in our hospital from November 2005 to November 2011 were chosen as the research objects. The clinical data of the patients were taken for retrospective analysis . The related clinical indicators before and after the treatment of anterior decompression and internal fixation were compared . Results The Frankel Grading had been significantly improved for the group after an -terior decompression and internal fixation. From the results of the comparison of the three clinical indicators of vertebral height (trailing edge) ,spinal stenosis,Cobb angle point of view ,the three indicators in patients after surgery had been effectively improved compared be -fore and after treatment ,P <0.05,the difference was

  10. 经伤椎椎弓根植骨联合伤椎椎弓根螺钉固定治疗胸腰段骨折%Transpedicular intracorporeal grafting combined with posterior short-segment pedicle screw via the injured vertebra for treatment of thoracolumbar fractures

    Institute of Scientific and Technical Information of China (English)

    李佳; 欧云生; 权正学; 蒋电明; 唐可; 安洪

    2011-01-01

    Objective To explore the clinical efficacy of transpedicular intracorporeal grafting combined with posterior short-segment pedicle screw via the injured vertebra for thoracolumbar fractures treatment. Methods A total of 52 patients of thoracolumbar fractures were treated with transpedicular intracorporeal grafting combined with posterior short-segment pedicle screw via the injured vertebra from June 2006 to December 2009. According to the AO classification, all of them are type A fracture. Preoperative, postoperative and follow-up X-ray were performed for evaluating anterior heights of the injured vertebra(AHIV) and Cobb's angle, as well, preoperative and postoperative CT scans were taken to measure the sagittal canal diameter(SCD). Postoperative complications and neurofunctional recovery of the spinal cord were evaluated. Results All cases were followed up about 12 to 30 months, averagely 16.5±7.8 months. There was no infection of incision and no aggravation of spinal cord function. There was no implant failure and no loss of spinal curvatures. After surgery and at final follow-up, anterior heights of the injured vertebra showed good recovery, and Cobb's angel appeared smaller. The sagittal canal diameter significantly reduced compared to that before surgery. In patients with incomplete injury, neurofunctions showed 1 to 2 grade improvement compared with the findings before operation. Conclusions Transpedicular intracorporeal grafting is effective to repair fractured vertebrae in the vertebral body defects, posterior short-segment pedicle screw via the injured vertebra can reconstruct the stability of thoracolumbar fractures, stable reconstruction of the anterior and middle columns and secured fixation of the posterior column. This technique is an effective method for treatment of A type thoracolumbar fractures.%目的 探讨经伤椎椎弓根植骨联合伤椎椎弓根螺钉固定治疗胸腰椎骨折的临床疗效.方法 回顾性研究2006年6月-2009年8

  11. Reconstruction and short-segment stabilization by posterior approach anterolateral decompression for treatment of severe thoracolumbar burst fractures%后路单侧侧前方减压钛网重建结合椎弓根钉内固定治疗胸腰椎爆裂骨折

    Institute of Scientific and Technical Information of China (English)

    王洪; 易小波; 任志宏; 蔺福辉; 胡鑫华; 陈晓东; 贺旭

    2012-01-01

    Objective To evaluate feasibility and therapeutic effect of surgery of posterior 270。decompression and reconstruction for the treatment of thoracolumbar injury with severe thoracolumbar burst fractures. Methods All of 28 patients with thoracolumbar burst fractures were treated with unilateral subtotal vertebraectomy through only the posterior approach, 270。decompression, titanium cage supporting bone autograft to reconstruct the anterior and middle column, pedicles screws stabilization. Spinal cord injury was evaluated with ASIA grade criterion. Reduction, decompression and fusion of fractures were evaluated through X-ray and computer tomography. Results All operations were completed successfully. The mean operation time was 3.2 hours and the mean blood loss was 1 200 ml. Cerebrospinal fluid leakage occurred in 2 patients. One case was involved in iatrogenic nerve root injury. No other severe complications were observed. No looseness and rupture of internal fixation, no obvious loss of vertebral height, spinal radian and vertebral canal volume were observed. Nervous function improved in different degree in most of the patients. Conclusion The operation of reconstruction and short-segment stabilization by anterolateral posterior approach decompression for the treatment of severe thoracolumbar burst fractures has the advantages of less injury, higher safety, complete decompression, immediate three-column stability of spine, with satisfactory clinical efficacy.%目的 探讨经后侧入路侧前方减压椎体前中柱钛网重建后路椎弓根内固定治疗胸腰椎重度爆裂骨折的安全性及疗效.方法 对28例胸腰椎爆裂骨折采用经后路单侧行椎体次全切除、椎体270°减压、钛网支撑植骨重建前中柱及椎弓根钉内固定.采用美国脊柱损伤学会(ASIA)分级进行神经功能评估,通过X线及CT片评估骨折复位、减压及骨融合情况.结果 手术均顺利完成,平均手术时间3.2 h;平均出血量1200

  12. 后路经椎弓根内固定联合椎体成形术对高龄胸腰段脊椎骨折的疗效研究%Effects of in Elderly Patients of Thoracolumbar Vertebral Fractures by Posterior Pedicle Screw Internal Fixation Combined with Vertebral Angioplasty

    Institute of Scientific and Technical Information of China (English)

    冉仁国; 王齐兵

    2016-01-01

    目的:探讨后路经椎弓根内固定联合椎体成形术对高龄胸腰段脊椎骨折的临床治疗效果。方法:36例高龄胸腰段脊柱骨折的高龄患者经确诊后并成功完成手术选取为样本,并选取术后每一位患者进行1个月和6个月两个时间的随访记录,术后Cobb's角、椎管狭窄率、椎体压缩比率为本次研究主要统计指标,统计分析后路经椎弓根内固定联合椎体成形术对高龄胸腰段脊椎骨折的治疗情况。结果:36例患者的平均手术时间、术中平均透视时间、平均术中出血量、术后Cobb's角、椎管狭窄率、椎体压缩比率相比较术前有较大提高(P<0.05),选取的1个月和6个月两个时间的随访记录经统计分析后差异无统计学意义(P>0.05)。发生骨水泥椎管渗漏的2例,发生内固定钉断裂的3例,未发生腹腔实质其器官损伤及退钉等等并发症情况。结论:通过后路椎弓根内固定加椎体成形术相结合治疗胸腰段脊柱具有优秀的生物力学性能,完善受伤椎体的形态完整及强度,术后病人预后效果好,效果较显著。%[ABSTRACT]Objective:To explore the posterior pedicle screw ifxation combined with vertebroplasty for spinal operation in elderly clinical effect in the treatment of thoracolumbar fractures. Methods:36 cases of old thoracolumbar spinal fracture in elderly patients after diagnosis and the successful completion of the operation selected as samples, and select the postoperative every patients were follow-up records of 1MONTH and 6MONTH two time and postoperative Cobb's angle, stenosis rate, vertebral compression ratio for the main statistical indicators, statistical analysis of posterior pedicle screw internal ifxation combined with vertebral forming operation for treatment of old thoracolumbar spinal fracture with percutaneous. Results: 36 patients, the average operative time, intraoperative mean lfuoroscopy time

  13. The Influence Factors and Nursing Interventions on the Compliance of Horizontal Position without Pillow after General Anesthesia in Thoracolumbar Disease Patients%胸腰椎疾病患者全麻术后去枕平卧位依从性的影响因素与护理干预

    Institute of Scientific and Technical Information of China (English)

    吕曼

    2013-01-01

    目的探讨胸腰椎疾病患者全麻术后去枕平卧位依从性的影响因素和干预措施。方法回顾性分析我科2012年8月~12月胸腰椎疾病全麻术后去枕平卧位依从性的影响因素,根据结果进行护理干预。结果胸腰椎疾病并行全麻手术患者术后6h内不能坚持体位指导152例。其中,因麻醉状态导致依从性差65例,占42.8%,医学相关知识缺乏20例,占13.2%,患者想急迫恢复健康15例,占9.9%,对医务人员信任度差17例,占11.2%,不舒适感23例,占15.1%,家属不配合12例,占7.9%。结论通过加强护患沟通,与患者及家属建立良好的医患关系;加强麻醉未清醒期间的安全管理和心理护理;落实责任制护理,重视健康教育等方式能提高胸腰椎疾病患者全麻术后去枕平卧位依从性。%Objective To summarize the influence factors and nursing interventions on the compliance of horizontal posi-tion without pillow after general anesthesia in thoracolumbar disease patients .Methods The influence factors on the compli-ance of horizontal position without pillow after general anesthesia in thoracolumbar disease were reviewed retrospectively , based on which the nursing interventions were given to the patients .Results 152 after -general-anesthesia thoracolumbar disease patients who couldn't adhere to horizontal position were reviewed .65 cases were due to narcotism (42 .8% );20 cases were due to lack of related medical knowledge (13 .2% );15 cases were due to the urgence for recovery (9 .9% );17 cases were due to their low confidence degree with medical staff (11 .2% );23 cases were due to discomfort (15 .1% );12 cases were due to family members'non-compliance (7 .9% ) .Con-clusions Strengthening nurse-patient communication ,establishing good relationships with patients and their family mem-bers ,strengthening the safety management and the psychological nursing before anaesthesia clear

  14. Fermions tunnelling with quantum gravity correction

    CERN Document Server

    liu, Zhen-Yu

    2014-01-01

    Quantum gravity correction is truly important to study tunnelling process of black hole. Base on the generalized uncertainty principle, we investigate the influence of quantum gravity and the result tell us that the quantum gravity correction accelerates the evaporation of black hole. Using corrected Dirac equation in curved spacetime and Hamilton-Jacobi method, we address the tunnelling of fermions in a 4-dimensional Schwarzschild spacetime. After solving the equation of motion of the spin 1/2 field, we obtain the corrected Hawking temperature. It turns out that the correction depends not only on the mass of black hole but aslo on the mass of emitted fermions. In our calculation, the quantum gravity correction accelerates the increasing of Hawking temperature during the radiation explicitly. This correction leads to the increasing of the evaporation of black hole.

  15. Fermions Tunnelling with Quantum Gravity Correction

    International Nuclear Information System (INIS)

    Based on the generalized uncertainty principle (GUP), we investigate the correction of quantum gravity to Hawking radiation of black hole by utilizing the tunnelling method. The result tells us that the quantum gravity correction retards the evaporation of black hole. Using the corrected covariant Dirac equation in curved spacetime, we study the tunnelling process of fermions in Schwarzschild spacetime and obtain the corrected Hawking temperature. It turns out that the correction depends not only on the mass of black hole but also on the mass of emitted fermions. In our calculation, the quantum gravity correction slows down the increase of Hawking temperature during the radiation explicitly. This correction leads to the remnants of black hole and avoids the evaporation singularity. (general)

  16. Honey mangxiao, rhubarb topical god tone hole remove pure compartmentallized.the thoracolumbar fractures abdominal distension nursing observation%蜜调芒硝、大黄外敷神阙穴解除单纯胸腰椎骨折腹胀的护理观察

    Institute of Scientific and Technical Information of China (English)

    龚惠华; 李润香; 刘华; 张强; 彭天忠

    2011-01-01

    Objective: To observe the honey mangxiao, rhubarb topical god tone hole remove pure compartmentallized.the thoracolumbar fractures abdominal distension nursing effect. Methods: Random 60 patients were divided into treatment group and control group each 30 cases. The treatment group mangxiao, rhubarb with honey adjustable compartmentallized.the acupuncture point;god topical Were treated by fasting, massaging, oral desulfurate agent. Results: The total effective rate of the treatment group 76.6% group and 93.3%, two groups was statistically significant difference (P< 0.01). Conclusion: Honey adjustable mangxiao,rhubarb topical god que acupuncture. point remove pure thoracolumbar fractures abdominal distension has good curative effect.%目的:观察蜜调芒硝、大黄外敷神阙穴解除单纯胸腰椎骨折腹胀的护理效果.方法:随机将60例患者分为治疗组和对照组各30例.治疗组用蜜调芒硝、大黄外敷神阙穴;对照组采用禁食、腹部按摩、口服缓泻剂.结果:治疗组的总有效率为93.3%,对照组为76.6%,两组差异有统计学意义(P<0.01).结论:蜜调芒硝、大黄外敷神阙穴解除单纯胸腰椎骨折腹胀有良好的疗效.

  17. Self-correction coil: operation mechanism of self-correction coil

    International Nuclear Information System (INIS)

    We discuss here the operation mechanism of self-correction coil with a simple model. At the first stage, for the ideal self-correction coil case we calculate the self-inductance L of self-correction coil, the mutual inductance M between the error field coil and the self-correction coil, and using the model the induced curent in the self-correction coil by the external magnetic error field and induced magnetic field by the self-correction coil. And at the second stage, we extend this calculation method to non-ideal self-correction coil case, there we realize that the wire distribution of self-correction coil is important to get the high enough self-correction effect. For measure of completeness of self-correction effect, we introduce the efficiency eta of self-correction coil by the ratio of induced magnetic field by the self-correction coil and error field. As for the examples, we calculate L, M and eta for two cases; one is a single block approximation of self-correction coil winding and the other is a two block approximation case. By choosing the adequate angles of self-correction coil winding, we can get about 98% efficiency for single block approximation case and 99.8% for two block approximation case. This means that by using the self-correction coil we can improve the field quality about two orders

  18. Rulison Site corrective action report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    Project Rulison was a joint US Atomic Energy Commission (AEC) and Austral Oil Company (Austral) experiment, conducted under the AEC`s Plowshare Program, to evaluate the feasibility of using a nuclear device to stimulate natural gas production in low-permeability gas-producing geologic formations. The experiment was conducted on September 10, 1969, and consisted of detonating a 40-kiloton nuclear device at a depth of 2,568 m below ground surface (BGS). This Corrective Action Report describes the cleanup of petroleum hydrocarbon- and heavy-metal-contaminated sediments from an old drilling effluent pond and characterization of the mud pits used during drilling of the R-EX well at the Rulison Site. The Rulison Site is located approximately 65 kilometers (40 miles) northeast of Grand Junction, Colorado. The effluent pond was used for the storage of drilling mud during drilling of the emplacement hole for the 1969 gas stimulation test conducted by the AEC. This report also describes the activities performed to determine whether contamination is present in mud pits used during the drilling of well R-EX, the gas production well drilled at the site to evaluate the effectiveness of the detonation in stimulating gas production. The investigation activities described in this report were conducted during the autumn of 1995, concurrent with the cleanup of the drilling effluent pond. This report describes the activities performed during the soil investigation and provides the analytical results for the samples collected during that investigation.

  19. Rulison Site corrective action report

    International Nuclear Information System (INIS)

    Project Rulison was a joint US Atomic Energy Commission (AEC) and Austral Oil Company (Austral) experiment, conducted under the AEC's Plowshare Program, to evaluate the feasibility of using a nuclear device to stimulate natural gas production in low-permeability gas-producing geologic formations. The experiment was conducted on September 10, 1969, and consisted of detonating a 40-kiloton nuclear device at a depth of 2,568 m below ground surface (BGS). This Corrective Action Report describes the cleanup of petroleum hydrocarbon- and heavy-metal-contaminated sediments from an old drilling effluent pond and characterization of the mud pits used during drilling of the R-EX well at the Rulison Site. The Rulison Site is located approximately 65 kilometers (40 miles) northeast of Grand Junction, Colorado. The effluent pond was used for the storage of drilling mud during drilling of the emplacement hole for the 1969 gas stimulation test conducted by the AEC. This report also describes the activities performed to determine whether contamination is present in mud pits used during the drilling of well R-EX, the gas production well drilled at the site to evaluate the effectiveness of the detonation in stimulating gas production. The investigation activities described in this report were conducted during the autumn of 1995, concurrent with the cleanup of the drilling effluent pond. This report describes the activities performed during the soil investigation and provides the analytical results for the samples collected during that investigation

  20. Hypernatremia: Correction Rate and Hemodialysis

    Directory of Open Access Journals (Sweden)

    Saima Nur

    2014-01-01

    Full Text Available Severe hypernatremia is defined as serum sodium levels above 152 mEq/L, with a mortality rate ≥60%. 85-year-old gentleman was brought to the emergency room with altered level of consciousness after refusing to eat for a week at a skilled nursing facility. On admission patient was nonverbal with stable vital signs and was responsive only to painful stimuli. Laboratory evaluation was significant for serum sodium of 188 mmol/L and water deficit of 12.0 L. Patient was admitted to medicine intensive care unit and after inadequate response to suboptimal fluid repletion, hemodialysis was used to correct hypernatremia. Within the first fourteen hours, sodium concentration only changed 1 mEq/L with a fluid repletion; however, the concentration dropped greater than 20 mEq/L within two hours during hemodialysis. Despite such a drastic drop in sodium concentration, patient did not develop any neurological sequela and was at baseline mental status at the time of discharge.