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Sample records for degenerative disk lesions

  1. Apoptotic pathways in degenerative disk lesions in the wrist.

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    Unglaub, Frank; Thomas, Susanne B; Kroeber, Markus W; Dragu, Adrian; Fellenberg, Jörg; Wolf, Maya B; Horch, Raymund E

    2009-12-01

    Degenerative articular disk perforations of the triangular fibrocartilage (TFC) of the wrist could result from chronic loading of the ulnocarpal joint. Apoptosis played a crucial role in fibrocartilage cell loss, and the purpose of this study was to clarify which apoptotic pathway was involved in the development of degenerative disk lesions. We also investigated whether ulna length played an etiologic role in the occurrence of fibrocartilage cell loss. Included in the study were 17 patients with degenerative articular disk tears of the TFC (Palmer type 2C). After arthroscopic debridement of the TFC, histologic sections were examined to assess the presence of apoptosis. Apoptosis was determined by use of caspase 3, caspase 8, and caspase 9 immunohistochemistry. Furthermore, Fas ligand and BID (BH3 interacting domain death) agonist were applied for immunohistochemical analysis. Cells positive for caspase 3, caspase 8, caspase 9, Fas ligand, and BID were found in all specimens. The number of cells positive for caspase 3 and BID was significantly increased in specimens from patients with an ulna-positive variance. In contrast, for cells positive for caspase 8, caspase 9, and Fas ligand, no significant difference was found between specimens from patients with an ulna-positive variance and those from patients with an ulna-neutral/ulna-negative variance. The extrinsic and intrinsic apoptotic pathways are involved in the development of degenerative disk lesions. Fibrocartilage cell loss occurs mainly through the intrinsic apoptotic pathway. The accumulation of apoptotic cells is not significantly different between the 3 zones of the TFC. It could be verified that ulna length is correlated with fibrocartilage cell loss. Ulnar shortening is a valuable treatment option for degenerative TFC lesions. Knowledge of the specific apoptotic pathway that is causing degenerative disk lesions is critical in selecting the appropriate and most beneficial therapeutic treatment to halt

  2. Expression of leptin, leptin receptor, and connective tissue growth factor in degenerative disk lesions in the wrist.

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    Unglaub, Frank; Wolf, Maya B; Kroeber, Markus W; Dragu, Adrian; Schwarz, Stephan; Mittlmeier, Thomas; Kloeters, Oliver; Horch, Raymund E

    2011-06-01

    The purpose of this study was to identify whether leptin and connective tissue growth factor (CTGF) occur in the degenerative fibrocartilage disk and whether cartilage cells express leptin receptors. The study included 23 patients diagnosed with degenerative articular disk tears of the triangular fibrocartilage (TFC) (Palmer type 2C). Patients were divided into 2 groups based on ulna length: 1 group consisted of patients with an ulna-positive variance (group A), and the other group included patients with ulna-negative or -neutral variance (group B). After arthroscopic debridement of the TFC, histologic sections of biopsy specimens were prepared. The biopsy specimens were immunohistochemically analyzed, and the quantity of leptin-, CTGF-, and leptin receptor-positive cells was assessed. Cells positive for leptin, leptin receptor, and CTGF were found. The number of cells positive for leptin was significantly increased in specimens of patients with an ulna-negative variance (group B). In contrast, no significant difference was found for leptin receptor and CTGF in biopsy specimens of patients with ulna-positive or ulna-negative/neutral variance. The inner, middle, and outer zones of the disk do not express significantly different quantities of marker-positive cells. Degenerative fibrocartilage disk tissue cells exhibit leptin receptors and are exposed to the markers leptin and CTGF, providing evidence of a local paracrine system and regenerative processes. Cells of disks from patients with an ulna-neutral/negative length express significantly higher numbers of leptin-positive cells. Level II, diagnostic study. Copyright © 2011 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  3. Imaging of lumbar degenerative disk disease: history and current state

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    Emch, Todd M. [Cleveland Clinic, Division of Neuroradiology, Imaging Institute, Neuroradiology L-10, Cleveland, OH (United States); Modic, Michael T. [Cleveland Clinic, Division of Neuroradiology, Imaging Institute, Neurological Institute T-13, Cleveland, OH (United States)

    2011-09-15

    One of the most common indications for performing magnetic resonance (MR) imaging of the lumbar spine is the symptom complex thought to originate as a result of degenerative disk disease. MR imaging, which has emerged as perhaps the modality of choice for imaging degenerative disk disease, can readily demonstrate disk pathology, degenerative endplate changes, facet and ligamentous hypertrophic changes, and the sequelae of instability. Its role in terms of predicting natural history of low back pain, identifying causality, or offering prognostic information is unclear. As available modalities for imaging the spine have progressed from radiography, myelography, and computed tomography to MR imaging, there have also been advances in spine surgery for degenerative disk disease. These advances are described in a temporal context for historical purposes with a focus on MR imaging's history and current state. (orig.)

  4. Cartilage cell proliferation in degenerative TFCC wrist lesions.

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    Unglaub, Frank; Thomas, Susanne B; Wolf, Maya B; Dragu, Adrian; Kroeber, Markus W; Mittlmeier, Thomas; Horch, Raymund E

    2010-08-01

    The central zone of the triangular fibrocartilage complex (TFCC) of the wrist is thought to be avascular and is generally considered to lack any healing potential. The purpose of this study was to investigate, if cartilage cells of degenerative disc lesions possess any healing or proliferation potential and whether ulna length plays a significant role in the proliferation process. Cells positive for proliferating cell nuclear antigen (PCNA) were found in all specimens. Specimens of patients with ulna positive variance showed a decreased number of PCNA positive cells than specimens of patients with either negative or neutral ulna variance. We found that cartilage cells of Palmer type 2C lesions undergo mitotic cell division, thus exhibiting proliferation capability. It could not be shown that ulnar length is significantly correlated with the number of PCNA positive cells.

  5. Nerve fiber staining investigations in traumatic and degenerative disc lesions of the wrist.

    Science.gov (United States)

    Unglaub, Frank; Wolf, Maya B; Dragu, Adrian; Schwarz, Stephan; Kroeber, Markus W; Horch, Raymund E

    2011-05-01

    Traumatic and degenerative disc lesions cause ulnar-sided wrist pain. To date, anatomical investigations of cadaver triangular fibrocartilage discs examining the innervation of the triangular fibrocartilage complex have found no evidence of nerve fibers in the healthy disc. In this study, we immunohistologically investigated biopsies from patients with either central traumatic or degenerative disc lesions, to determine the existence of nerve fibers. We hypothesized that an ingrowth of nerve fibers causes ulnar-sided wrist pain associated with traumatic and degenerative disc lesions. We included 32 patients with a traumatic Palmer 1A lesion and 17 patients with a degenerative Palmer 2C lesion in the study. We obtained a biopsy of each patient and stained the specimen with protein gene product 9.5 for nerve fiber detection. There were no nerve fibers in either traumatic or degenerative disc lesions. In addition, the marginal areas of the biopsies showed no evidence of nerve fibers. Traumatic and degenerative disc lesions show no ingrowth of nerve fibers. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  6. Degenerative disk vascularization on MRI: correlation with clinical and histopathologic findings

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    Staebler, A. [Dept. of Diagnostic Radiology, Klinikum Grosshadern, Muenchen (Germany); Scheidler, J. [Dept. of Diagnostic Radiology, Klinikum Grosshadern, Muenchen (Germany); Seiderer, M. [Dept. of Diagnostic Radiology, Klinikum Grosshadern, Muenchen (Germany); Reiser, M. [Dept. of Diagnostic Radiology, Klinikum Grosshadern, Muenchen (Germany); Weiss, M. [Dept. of Pathology, Klinikum Grosshadern, Muenchen (Germany); Kroedel, A. [Dept. of Orthopedic Surgery, Klinikum Grosshadern, Muenchen (Germany)

    1996-02-01

    Fifty-tree patients with localized painful spine syndrome were investigated prospectively by contrast-enhanced MRI. Pain was not predominantly radiating and there was no clinical evidence of spinal infection. In all patients, sagittal SE T1-weighted, fast-SE T2-weighted or turbo-STIR, and T1-weighted frequency-selective fat-suppressed images were obtained. We identified 37 vascularized disks in 26 patients. In 18 patients the changes had occurred spontaneously, in 6, the affected disk had been operated on previously, and 2 patients had spondylolisthesis. In 15 patients, vascularization was accompanied by medullary edema adjacent to the vertebral endplates. In one of the vascularized disks, herniation was also found. In seven patients, ventral diskectomy was performed. Histopathologic findings confirmed disk vascularization in six of seven cases. Degenerative, band-like disk vascularization is a feature which is associated with local pain. It is demonstrated by contrast-enhanced MRI. Degenerative disk vascularization is an important differential diagnosis to bacterial spondylodiskitis. It can be a cause of pain in patients with postdiskectomy syndrome. (orig./MG)

  7. Nucleoplasty for treating lumbar disk degenerative low back pain: an outcome prediction analysis

    Directory of Open Access Journals (Sweden)

    Liliang PC

    2016-10-01

    Full Text Available Po-Chou Liliang,1 Kang Lu,1 Cheng-Loong Liang,1 Ya-Wen Chen,2,3 Yu-Duan Tsai,1 Yuan-Kun Tu4 1Department of Neurosurgery, E-Da Hospital, 2Department of Nursing, I-Shou University, 3School of Nursing, Kaohsiung Medical University, 4Department of Orthopedic Surgery, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan Purpose: Nucleoplasty is a minimally invasive technique that is considered efficacious in alleviating lumbar disk degenerative low back pain (LBP. The efficacy of nucleoplasty and identified variables that can predict pain relief for nucleoplasty was reported. Patients and methods: Between December 2013 and November 2015, 47 nucleoplasty procedures on 47 lumbar disks in 31 consecutive patients were performed. The outcome was evaluated using a visual analog scale (VAS score. Improvements of ≥50% in VAS scores were considered substantial pain relief. The variables associated with pain relief after nucleoplasty included: 1 age; 2 sex; 3 body mass index; 4 hyperintensity zone at the rear of the disk; 5 hypointensity of the disk; 6 Modic changes of the end plates; 7 spinal instability pain; and 8 discography results. Results: Twenty-one patients (67.7% experienced substantial pain relief. The most common side effects following nucleoplasty were soreness at the needle puncture site (64.5%, numbness in the lower leg (12.9%, and increased intensity of back pain (9.7%. All side effects were transient. Multivariate analysis revealed that the discography results were the most critical predictor for substantial pain relief of nucleoplasty (P=0.03. The sensitivity and specificity of discography were 92.8% and 62.5%, respectively. Conclusion: Discography results could improve the success rate of nucleoplasty in the treatment of disk degenerative LBP. Keywords: low back pain, lumbar disk degenerative, nucleoplasty, discography 

  8. Surgical management of degenerative meniscus lesions: the 2016 ESSKA meniscus consensus.

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    Beaufils, Ph; Becker, R; Kopf, S; Englund, M; Verdonk, R; Ollivier, M; Seil, R

    2017-02-01

    A degenerative meniscus lesion is a slowly developing process typically involving a horizontal cleavage in a middle-aged or older person. When the knee is symptomatic, arthroscopic partial meniscectomy has been practised for a long time with many case series reporting improved patient outcomes. Since 2002, several randomised clinical trials demonstrated no additional benefit of arthroscopic partial meniscectomy compared to non-operative treatment, sham surgery or sham arthroscopic partial meniscectomy. These results introduced controversy in the medical community and made clinical decision-making challenging in the daily clinical practice. To facilitate the clinical decision-making process, a consensus was developed. This initiative was endorsed by ESSKA. A degenerative meniscus lesion was defined as a lesion occurring without any history of significant acute trauma in a patient older than 35 years. Congenital lesions, traumatic meniscus tears and degenerative lesions occurring in young patients, especially in athletes, were excluded. The project followed the so-called formal consensus process, involving a steering group, a rating group and a peer-review group. A total of 84 surgeons and scientists from 22 European countries were included in the process. Twenty questions, their associated answers and an algorithm based on extensive literature review and clinical expertise, were proposed. Each question and answer set was graded according to the scientific level of the corresponding literature. The main finding was that arthroscopic partial meniscectomy should not be proposed as a first line of treatment for degenerative meniscus lesions. Arthroscopic partial meniscectomy should only be considered after a proper standardised clinical and radiological evaluation and when the response to non-operative management has not been satisfactory. Magnetic resonance imaging of the knee is typically not indicated in the first-line work-up, but knee radiography should be used as

  9. X-ray diagnosis of post-traumatic degenerative-dystrophic lesions of the vertebrae

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    Novikov, V.P. (Omskij Meditsinskij Inst. (USSR))

    Immediate and long-term consequences of the spinal injury have been studied in 221 patients aged 13 to 70 years, applying clinical and radiological methods. Various degenerative-dystrophic alterations have been frequently found at the level of the damaged spinal segment and included cartilaginous knots and discal hernia and fibrosis, local spondylosis and spondylarthrosis, osteochondrosis, calcification of the disk and ligamentous apparatus. These pathologic changes infrequently cause patients' complaints and neurological disturbances. The degenerative-dystrophic processes in the spine, following an acute injury manifest no specific features, except for some peculiarities of the traumatic cartilaginous knot (greater size and depth, partial hanging of the obturating plate over the knot bed). The type and gravity of the fracture, the degree of static-dynamic disorders of the vertebral column and, to some extent, the patient's age most significantly determine the development of the degenerative-dystrophic processes in the damaged spinal segment. Post-traumatic clinicofunctional examination of the spine has been proved important.

  10. Degenerative and vascular lesions of the brain have synergistic effects in dementia of the elderly.

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    Zekry, Dina; Duyckaerts, Charles; Moulias, Robert; Belmin, Joël; Geoffre, Caroline; Herrmann, François; Hauw, Jean-Jacques

    2002-05-01

    The relative importance of vascular and Alzheimer's disease (AD) lesions, their interaction in the development of cognitive impairment and the very existence of mixed dementia induced by the potentiation of both mechanisms remain controversial. The aim of this study was to assess whether the patients with infarcts and lacunes have fewer plaques and tangles than those without vascular lesions, for similar severity of clinical dementia. We performed a prospective clinicopathological study in elderly patients of a long-stay care unit. The severity of clinical dementia was assessed by psychometry performed according to standardized methods less than 6 months before death. A volumetric study of cerebral vascular lesions was performed at post-mortem study of the brain. The density of neuritic plaques (SP), Amyloid beta focal deposits (A beta FD), and neurofibrillary tangles (NFT) in the temporal and frontal isocortex was quantified. According to DSM III criteria, 28 of the 33 patients for whom autopsies were performed had dementia. Twenty-four of the included patients had degenerative or vascular lesions, or both. The volume of infarcts and lacunes was significantly correlated with the severity of cognitive impairment. The density of SP, A beta FD and NFT in the temporal and frontal isocortex was significantly lower when vascular lesions were present. For similar clinical severity of dementia, there were fewer AD lesions in patients with vascular lesions than in those without vascular lesions.

  11. Relationships between disk displacement, joint effusion, and degenerative changes of the TMJ in TMD patients based on MRI findings.

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    Roh, Hee-Seok; Kim, Wook; Kim, Young-Ku; Lee, Jeong-Yun

    2012-04-01

    This study was performed to investigate the relationships between disk displacement, joint effusion, and degenerative changes in patients with temporomandibular disorders using MRI. Randomly selected MRIs of 508 temporomandibular joints of 254 patients (92 males and 162 females, mean age was 30.5±12.0 years) were reviewed retrospectively. Seventy-eight percent (198 out of 254) of the patients complained of joint pain. Compared with joints with a normal disk position, the joints with anterior disk displacement with reduction showed a 2.01 odds ratio (Pdegenerative changes and a 2.85 odds ratio (Pdegenerative changes and a 4.61 odds ratio (Pdegenerative changes and joint effusions increase with displacement of the disk position in patients with temporomandibular disorders. Although all disk displacement situations do not progress to painful joints and/or degenerative joint diseases, the possibility of an increased risk of progression by a breakdown in the balance between a patient's adaptive capacity and functional loading of the TMJ should be assessed in each and every patient through comprehensive evaluation of various contributing factors.

  12. Quantifying Quadriceps Muscle Strength in Patients With ACL Injury, Focal Cartilage Lesions, and Degenerative Meniscus Tears

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    Eitzen, Ingrid; Grindem, Hege; Nilstad, Agnethe; Moksnes, Håvard; Risberg, May Arna

    2016-01-01

    Background: Reduced quadriceps strength influences knee function and increases the risk of knee osteoarthritis. Thus, it is of significant clinical relevance to precisely quantify strength deficits in patients with knee injuries. Purpose: To evaluate isokinetic concentric quadriceps muscle strength torque values, assessed both from peak torque and at specific knee flexion joint angles, in patients with anterior cruciate ligament (ACL) injury, focal cartilage lesions, and degenerative meniscus tears. Study Design: Cohort study; Level of evidence, 3. Methods: Data were synthesized from patients included in 3 previously conducted research projects: 2 prospective cohort studies and 1 randomized controlled trial. At the time of inclusion, all patients were candidates for surgery. Isokinetic concentric quadriceps muscle strength measurements (60 deg/s) were performed at baseline (preoperative status) and after a period of progressive supervised exercise therapy (length of rehabilitation period: 5 weeks for ACL injury, 12 weeks for cartilage lesions and degenerative meniscus). Outcome measures were peak torque and torque at specific knee flexion joint angles from 20° to 70°. All patients had unilateral injuries, and side-to-side deficits were calculated. For comparisons between and within groups, we utilized 1-way analysis of variance and paired t tests, respectively. Results: In total, 250 patients were included. At baseline, cartilage patients had the most severe deficit (39.7% ± 24.3%; P torque was consistently measured at 60° of knee flexion, whereas the largest mean deficits were measured at 30° at baseline and 70° at retest for the ACL group, at 70° at baseline and retest for the degenerative meniscus group, and at 60° at baseline and at 50° at retest for the cartilage group. Conclusion: This study underlines the importance of including torque at specific knee flexion joint angles from isokinetic assessments to identify the most severe quadriceps muscle

  13. Preliminary results of automated removal of degenerative joint disease in bone scan lesion segmentation

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    Chu, Gregory H.; Lo, Pechin; Kim, Hyun J.; Auerbach, Martin; Goldin, Jonathan; Henkel, Keith; Banola, Ashley; Morris, Darren; Coy, Heidi; Brown, Matthew S.

    2013-03-01

    Whole-body bone scintigraphy (or bone scan) is a highly sensitive method for visualizing bone metastases and is the accepted standard imaging modality for detection of metastases and assessment of treatment outcomes. The development of a quantitative biomarker using computer-aided detection on bone scans for treatment response assessment may have a significant impact on the evaluation of novel oncologic drugs directed at bone metastases. One of the challenges to lesion segmentation on bone scans is the non-specificity of the radiotracer, manifesting as high activity related to non-malignant processes like degenerative joint disease, sinuses, kidneys, thyroid and bladder. In this paper, we developed an automated bone scan lesion segmentation method that implements intensity normalization, a two-threshold model, and automated detection and removal of areas consistent with non-malignant processes from the segmentation. The two-threshold model serves to account for outlier bone scans with elevated and diffuse intensity distributions. Parameters to remove degenerative joint disease were trained using a multi-start Nelder-Mead simplex optimization scheme. The segmentation reference standard was constructed manually by a panel of physicians. We compared the performance of the proposed method against a previously published method. The results of a two-fold cross validation show that the overlap ratio improved in 67.0% of scans, with an average improvement of 5.1% points.

  14. [Appendicular ureteroplasty to repair a ureteric lesion during disk surgery].

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    Joual, Abdenbi; Taha, Abdellatif; Querfani, Badereddine; Sahnoun, Abderrazak; Hamid, Fekak; El Mrini, Mohamed

    2005-09-01

    Extensive ureteric lesions raise difficult problems of surgical repair. This is also the case for upper ureteric lesions that often require replacement of the damaged segment or even autologous transplantation. The authors report a case of iatrogenic ureteric lesion resulting in a large defect in a patient operated 6 months previously for an L4-L5 disk hernia, which was treated successfully by interposition of an appendicular graft between the two ureteric stumps. In the light of this case, the authors discuss the various appearances of iatrogenic ureteric lesions with particular emphasis on the value of appendicular ureteroplasty due to its simplicity and low morbidity, while waiting for progress in the field of biocompatible substitutes.

  15. MR Imaging of Degenerative Cartilage Lesions of the Knee Joint in Floor Layers and Graphic Designers

    DEFF Research Database (Denmark)

    Rytter, Søren; Thomsen, Birthe Lykke; Christensen, Birgitte Schütt

    2016-01-01

    of this explorative study, based on available data, was to examine the prevalence of magnetic resonance imaging (MRI)-detected knee cartilage lesions in male floor layers exposed to kneeling work, as compared to non-exposed male graphic designers. Methods: MRI of the knees was conducted in 92 floor layers and 49...... graphic designers, with a mean age of 55.6 years (42-70 years). MRI-detected cartilage lesions were graded according to a ninepoint lesion scale using a modified Whole Organ Resonance Score (WORMS) system. Severe knee cartilage lesions were defined as a maximal lesion score ≥ 3 in 1) the medial...... tibiofemoral posterior area, the most strained area during kneeling and 2) the total knee. Presence of lesions was compared in floor layers and graphic designers after adjusting for age, BMI, seniority, knee injuries, and sports activity in logistic regression analyses for correlated data, and investigated...

  16. Long-term Treatment Effects of Lumbar Arthrodeses in Degenerative Disk Disease: A Systematic Review With Meta-Analysis.

    Science.gov (United States)

    Noshchenko, Andriy; Hoffecker, Lilian; Lindley, Emily M; Burger, Evalina L; Cain, Christopher M J; Patel, Vikas V

    2015-11-01

    Systematic review with meta-analysis. To (1) evaluate long-term patient-centered clinical outcomes after lumbar arthrodesis with or without decompression for lumbar spondylosis (LS); and (2) compare these outcomes with those of alternative treatments, including nonsurgical and surgical which maintain mobility of the lumbar spine. The effective treatment of LS is a complex clinical and economic concern for patients and health care providers. (1) randomized controlled clinical trials (RCTs) comparing treatment effects of lumbar arthrodesis with other interventions; (2) participants: skeletally mature adults with lumbar degenerative disk disease. Ovid MEDLINE, Embase, the Cochrane Library, and others. All years through February of 2013 were included. Patient-centered clinical outcomes before treatment, at 12, 24, or >24 months of follow-up, and rate of complications and additional surgical treatment were collected. A meta-analysis was performed to evaluate pooled treatment effects. The GRADE approach was applied to evaluate the level of evidence. The review included 38 studies of 5738 participants. All studies showed strong or at least moderate treatment effects of lumbar arthrodesis at 12, 24, and 48-72 months of follow-up. The level of evidence was moderate at 12 and 24 months, and low at 48-72 months. The pooled long-term treatment effect of lumbar arthrodesis exceeded those of: nonsurgical treatment (Pinferiority versus arthroplasty at 12 and 24 months of follow-up (P<0.001), but not after 24 months postoperative. This review indicates that surgical stabilization of the lumbar spine is an effective treatment for LS; in particular, for patients with severe chronic low back pain that has been resistant to ≥3 months of conservative therapy.

  17. Interspinous spacer decompression (X-STOP) for lumbar spinal stenosis and degenerative disk disease: a multicenter study with a minimum 3-year follow-up.

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    Puzzilli, Fabrizio; Gazzeri, Roberto; Galarza, Marcelo; Neroni, Massimiliano; Panagiotopoulos, Konstantinos; Bolognini, Andrea; Callovini, Giorgio; Agrillo, Umberto; Alfieri, Alex

    2014-09-01

    Interspinous distraction devices provide an effective treatment for patients suffering from lumbar spinal stenosis and/or degenerative disk disease. The aim of this multicenter study was the prospective evaluation of patients treated for symptomatic lumbar spinal stenosis with interspinous process decompression (IPD) implants compared with a population of patients managed with conservative treatment. 542 patients affected by symptomatic lumbar spine degenerative disease were enrolled in a controlled trial. 422 patients underwent surgical treatment consisting of X-STOP device implantation, whereas 120 control cases were managed conservatively. Both patient groups underwent follow-up evaluations at 6, 12, 24, and 36 months using the Zurich Claudication Questionnaire, the Visual Analog Scale score and spinal lumbar X-rays, CT scans and MR imaging. One-year follow-up evaluation revealed positive good results in the 83.5% of patients treated with IPD with respect to 50% of the nonoperative group cases. During the first three years, in 38 out of the 120 control cases, a posterior decompression and/or spinal fixation was performed because of unsatisfactory results of the conservative therapy. In 24 of 422 patients, the IPD device had to be removed, and a decompression and/or pedicle screw fixation was performed because of the worsening of neurological symptoms. Our results support the effectiveness of surgery in patients with stenosis. IPD may offer an effective and less invasive alternative to classical microsurgical posterior decompression in selected patients with spinal stenosis and lumbar degenerative disk diseases.

  18. Optical biopsy of pre-malignant or degenerative lesions: the role of the inflammatory process

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    da Silva Martinho, Herculano

    2011-03-01

    Recent technological advances in fiber optics, light sources, detectors, and molecular biology have stimulated unprecedented development of optical methods to detect pathological changes in tissues. These methods, collectively termed "optical biopsy," are nondestructive in situ and real-time assays. Optical biopsy techniques as fluorescence spectroscopy, polarized light scattering spectroscopy, optical coherence tomography, confocal reflectance microscopy, and Raman spectroscopy had been extensively used to characterize several pathological tissues. In special, Raman spectroscopy technique had been able to probe several biochemical alterations due to pathology development as change in the DNA, glycogen, phospholipid, non-collagenous proteins. All studies claimed that the optical biopsy methods were able to discriminate normal and malignant tissues. However, few studies had been devoted to the discrimination of very common subtle or early pathological states as inflammatory process, which are always present on, e.g., cancer lesion border. In this work we present a systematic comparison of optical biopsy data on several kinds of lesions were inflammatory infiltrates play the role (breast, cervical, and oral lesion). It will be discussed the essential conditions for the optimization of discrimination among normal and alterated states based on statistical analysis.

  19. A Comparison of Magnetic Resonance Imaging Muscle Fat Content in the Lumbar Paraspinal Muscles with Patient-Reported Outcome Measures in Patients with Lumbar Degenerative Disk Disease and Focal Disk Prolapse

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    Bhadresha, Ashwin; Lawrence, Owen John; McCarthy, Michael J. H.

    2016-01-01

    Study Design Retrospective study. Objectives To assess the fatty atrophy of the lumbar paraspinal muscles (LPMs) as determined using magnetic resonance imaging in patients with lumbar degenerative disk disease (DDD) and focal disk herniation and to determine if fatty atrophy is associated with patient-reported outcome measures (PROMS). Methods One hundred sixty-five patients with lumbar DDD were identified from a PROMS database of >1,500 patients. These patients were divided into two study groups: DDD alone (n = 58) and DDD with disk herniation (n = 107). A grid was randomly applied to the axial scans at the L3–L4, L4–L5, and L5–S1 levels. The muscle-to-fat ratio of the LPMs was recorded and compared with PROMS data. Subcutaneous fat thickness at each level was also measured. Results This study found no difference in the muscle-to-fat ratio between the DDD and disk herniation groups. There was no association between the muscle-to-fat ratio and PROMS data in either group. There was significantly more subcutaneous fat at all levels in the DDD group as compared with the disk prolapse group. In DDD and disk prolapses, subcutaneous fat was thicker in women (p = 0.013 and 0.001). In patients with DDD, more subcutaneous fat was associated with disability (p Muscle content of erector spinae and multifidus negatively correlated with increasing age in both groups at the L3–L4 level. Conclusions Muscle fat content in the LPM does not appear to relate to PROMS. Muscle content decreases with age. Those with low back pain (DDD) have greater subcutaneous fat thickness. PMID:27190744

  20. Long-Term Outcomes of Posterior Lumbar Interbody Fusion Using Stand-Alone Ray Threaded Cage for Degenerative Disk Disease: A 20-Year Follow-Up

    Science.gov (United States)

    Medrano, Belen G.; Noriega, David C.

    2016-01-01

    Study Design Retrospective study. Purpose To analyze outcomes of posterior lumbar interbody fusion (PLIF) stand-alone cages. Overview of Literature PLIF for degenerative disk disease using stand-alone cages has lost its popularity owing to implant-related complications and pseudoarthrosis. Methods We analyzed the records of 45 patients (18 women, 27 men), operated between January 1994 and December 1996, with a mean follow-up of 18 years 3 months (20 years 3 months–22 years 3 months). Clinical outcomes were measured using visual analogue score (VAS), Oswestry disability index (ODI), Odom's criteria, and radiological measurements of fusion rate, Cobb angle, and implant-related complications conducted at the preoperative evaluation, hospital discharge, 12-month follow-up, and final follow-up. Results Preoperative mean VAS (back) was 6.9 and VAS (radicular) was 7.2, with mean improvements (p Pseudoarthrosis was observed in five patients (11.1%), of whom, three (6.6%) required re-operation. Preoperative disk height was 9.23 mm, which increased to 13.33 mm in the immediate postoperative evaluation and was maintained at 10.0 mm at the final follow-up (p <0.05). The preoperative mean L1–S1 Cobb angle was 34.7°, which changed to 44.7° in the immediate postoperative evaluation and dropped to 39.7° at the final follow-up (p <0.005). Conclusions PLIF stand-alone cages were associated with good clinical outcomes. Although the fusion rate was excellent, maintenance of disk heights and a lordotic alignment were not achieved in the long term. PMID:27994787

  1. Degenerative lesions of the plantar fascia: surgical treatment by fasciectomy and excision of the heel spur. A report on 38 cases.

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    Jarde, Olivier; Diebold, Patrice; Havet, Eric; Boulu, Gilles; Vernois, Joël

    2003-06-01

    The authors studied 38 cases of degenerative lesions of the plantar fascia which were treated surgically between 1989 and 1999. MRI showed chronic fasciitis in eight cases and an old rupture of the plantar fascia in 30 cases. Surgical treatment, which was performed in all cases after failure of conservative treatment of several months duration, combined excision of the fascia with resection of the heel spur. Histological examination found inflammation in all cases (fasciitis or rupture), calcification of the aponeurosis in four cases, cartilaginous metaplasia in four and fibromatosis in four. Patients were assessed a minimum of one year and a maximum of seven years after operation. The postoperative results were assessed using three criteria: resolution of pain, results on the static foot and patients' functional activity. Overall there were 24 very good and good results, nine fair and five poor. MRI performed at the time of follow-up revealed good healing of the plantar fascia in 16 cases, defects in two cases, inflammation in seven cases and defects associated with inflammation in 13 cases. Surgical treatment may be considered in cases where conservative treatment of talalgia has failed. Symptoms originating from degenerative damage to the plantar fascia, such as rupture or fasciitis, may benefit from fasciectomy. Short-term results show resolution of pain in 75% of cases, and a slight sagging of the plantar arch. Pre-operative MRI study is useful to determine the exact location of the lesions.

  2. Degenerative disorders of the spine

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    Gallucci, Massimo; Puglielli, Edoardo; Splendiani, Alessandra [University of L' Aquila, Department of Radiology, L' Aquila (Italy); Pistoia, Francesca; Spacca, Giorgio [S. Salvatore Hospital, Department of Neuroscience, L' Aquila (Italy)

    2005-03-01

    Patients with back pain and degenerative disorders of the spine have a significant impact on health care costs. Some authors estimate that up to 80% of all adults experience back pain at some point in their lives. Disk herniation represents one of the most frequent causes. Nevertheless, other degenerative diseases have to be considered. In this paper, pathology and imaging of degenerative spine diseases will be discussed, starting from pathophysiology of normal age-related changes of the intervertebral disk and vertebral body. (orig.)

  3. [Impact of obesity in the pathophysiology of degenerative disk disease and in the morbidity and outcome of lumbar spine surgery].

    Science.gov (United States)

    Delgado-López, Pedro David; Castilla-Díez, José Manuel

    2017-07-24

    Obesity (BMI>30Kg/m(2)) is a pandemic with severe medical and financial implications. There is growing evidence that relates certain metabolic processes within the adipose tissue, preferentially abdominal fat, with a low-intensity chronic inflammatory state mediated by adipokines and other substances that favor disk disease and chronic low back pain. Obesity greatly conditions both the preoperative evaluation and the spinal surgical technique itself. Some meta-analyses have confirmed an increase of complications following lumbar spine surgery (mainly infections and venous thrombosis) in obese subjects. However, functional outcomes after lumbar spine surgery are favorable although inferior to the non-obese population, acknowledging that obese patients present with worse baseline function levels and the prognosis of conservatively treated obese cohorts is much worse. The impact of preoperative weight loss in spine surgery has not been prospectively studied in these patients. Copyright © 2017 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Effects of Smoking on Subjective and Objective Measures of Pain Intensity, Functional Impairment, and Health-Related Quality of Life in Lumbar Degenerative Disk Disease.

    Science.gov (United States)

    Joswig, Holger; Stienen, Martin N; Smoll, Nicolas R; Corniola, Marco V; Chau, Ivan; Schaller, Karl; Hildebrandt, Gerhard; Gautschi, Oliver P

    2017-03-01

    Numerous studies assessed the effects of smoking on lumbar degenerative disk disease (DDD); they focused on patient-reported outcome measures (PROMs) and yielded conflicting results. In this 2-center study on consecutive patients receiving surgical treatment for lumbar DDD, subjective functional impairment (SFI) in terms of PROMs including visual analog scale back and leg pain, Roland-Morris, Oswestry Disability Index, Euro-Qol-5D, and a Short-Form 12 physical component summary was determined at baseline, 3 days, 6 weeks, 6 months, and 1 year postoperatively. Age- and sex-adjusted T-scores of objective functional impairment (OFI) were determined using the Timed Up and Go test up to 6 weeks postoperatively. The responder status was defined by the minimal clinically important difference. We analyzed 375 patients (n = 96 [25.6%] smokers and n = 279 [74.4%] nonsmokers). SFI on any of the PROMs before treatment was similar in smokers and nonsmokers. Smokers were more likely to have OFI in univariate logistic regression analysis (95% confidence interval 1.31-3.37, P = 0.002). In multivariate analysis, however, this relationship became insignificant (95% confidence interval 0.85-2.38, P = 0.184). The smoking status had no predictive capacity on the 6-week SFI or OFI responder status, and there were no differences in any of the PROMs until the 1-year follow-up. PROMs measuring SFI for pain intensity, functional impairment, and health-related quality of life were similar in smokers and nonsmokers before surgery for lumbar DDD, as well as postoperatively. The smoking status has negligible impact on the Timed Up and Go test, which appears to be a robust assessment tool for OFI. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Patients' Preference of the Timed Up and Go Test or Patient-Reported Outcome Measures Before and After Surgery for Lumbar Degenerative Disk Disease.

    Science.gov (United States)

    Joswig, Holger; Stienen, Martin N; Smoll, Nicolas R; Corniola, Marco V; Chau, Ivan; Schaller, Karl; Hildebrandt, Gerhard; Gautschi, Oliver P

    2017-03-01

    The Timed Up and Go (TUG) test, as a measure of objective functional impairment in lumbar degenerative disk disease (DDD), complements patient-reported outcome measures (PROMs) of subjective functional impairment. Prospective 2-center study on consecutive patients scheduled for surgical treatment for lumbar DDD who underwent an objective (TUG test) and subjective (PROMs) functional assessment before and 1 and 3 days after surgery. PROMs included the visual analog scale (VAS), Roland-Morris Disability Index (RMDI), Oswestry Disability Index (ODI), Euro-Qol (EQ-5D), and Short Form 12 (SF-12) questionnaires. On completion of each assessment, patients were asked whether they would prefer performing the TUG test or completing the PROMs questionnaires. A total of 109 of 125 patients (87.2%) completed the assessments. Preoperatively, patients were 2.18 times as likely to prefer the TUG test to the PROMs (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.27-3.75). On postoperative days 1 and 3, patients were 5.79 (OR, 5.79; 95% CI, 3.23-10.37) and 6.33 times as likely to prefer the TUG test to the PROMs, respectively (OR, 6.33; 95% CI, 3.51-11.41). There were no statistical differences in baseline characteristics, TUG t scores, VAS, RMDI, ODI, SF-12, and EQ-5D index between patients preferring either the TUG test or the PROMs questionnaires. The TUG test is preferred over a battery of PROMs by 60%-70% of patients with lumbar DDD not only in the preoperative, but also in the postoperative, setting. High functional disability does not result in avoidance of the TUG test, and repeated assessments lead to higher preference. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Classification of the degenerative grade of lesions of supraspinatus rotator cuff tendons by FT-Raman spectroscopy

    Science.gov (United States)

    Palma Fogazza, Bianca; da Silva Carvalho, Carolina; Godoy Penteado, Sergio; Meneses, Cláudio S.; Abrahão Martin, Airton; da Silva Martinho, Herculano

    2007-02-01

    FT-Raman spectroscopy was employed to access the biochemical alterations occurring on the degenerative process of the rotator cuff supraspinatus tendons. The spectral characteristic variations in the 351 spectra of samples of 39 patients were identified with the help of Principal Components Analysis. The main variations occurred in the 840-911; 1022- 1218; 1257; 1270; 1300; 1452; 1663; and 1751 cm -1 regions corresponding to the vibrational bands of proline, hydroxiproline, lipids, nucleic acids, carbohydrates, collagen, and elastin. These alterations are compatible with the pathology alterations reported on the literature. Scattering plots of PC 4 vs PC 2 and PC 3 vs PC 2 contrasted with histopathological analysis has enabled the spectral classification of the data into normal and degenerated groups of tendons. By depicting empiric lines the estimated sensibility and specificity were 39,6 % and 97,8 %, respectively for PC 4 vs PC 2 and 36,0 % and 100 %, respectively for PC 3 vs PC 2. These results indicate that Raman spectroscopy can be used to probe the general tendon quality and could be applied as co adjuvant element in the usual arthroscopy surgery apparatus to guide the procedure and possibly infer about the probability of rerupture.

  7. Degenerative disease of the spine.

    Science.gov (United States)

    Gallucci, Massimo; Limbucci, Nicola; Paonessa, Amalia; Splendiani, Alessandra

    2007-02-01

    Degenerative disease of the spine is a definition that includes a wide spectrum of degenerative abnormalities. Degeneration involves bony structures and the intervertebral disk, although many aspects of spine degeneration are strictly linked because the main common pathogenic factor is identified in chronic overload. During life the spine undergoes continuous changes as a response to physiologic axial load. These age-related changes are similar to pathologic degenerative changes and are a common asymptomatic finding in adults and elderly persons. A mild degree of degenerative changes is paraphysiologic and should be considered pathologic only if abnormalities determine symptoms. Imaging allows complete evaluation of static and dynamic factors related to degenerative disease of the spine and is useful in diagnosing the different aspects of spine degeneration.

  8. Refresher course for general practitioners: the treatment of lumbar disk lesions.

    Science.gov (United States)

    Cyriax, J

    1990-01-01

    Reprinted with permission from British Medical Journal, 2:1434-1438, 1950. Much confusion exists on this subject. Some years ago the main difficulty was to appear credible when attributing such well-known conditions as lumbago, fibrositis, and sciatica to so recent a discovery as a disk lesion. Now that the diagnosis has become widely accepted, medical men have found themselves in a therapeutic quandary. Traditional measures such as drugs (apart from analgesics), radiant heat, diathermy, massage, exercises, injecting nodules, and "taking the waters" have suddenly lost their last vestige of theoretical justification. Little has so far come forward to replace these abandoned types of "treatment", and the distress of doctors and patients is heightened when they find out that the only radical treatment is an operation - by no means always successful - warranted only in extreme cases. This therapeutic nihilism is quite unjustified, for there are a number of simple treatments, none a panacea, each with its due proportion of successes. Few patients prove unrelievable if conservative means are intelligently employed, and it is only for some of these few that surgery need to be contemplated at all. J Orthop Sports Phys Ther 1990;12(4):163-169.

  9. Human Amniotic Tissue-derived Allograft, NuCel, in Posteriolateral Lumbar Fusions for Degenerative Disc Disease

    Science.gov (United States)

    2017-09-14

    Lumbar Degenerative Disc Disease; Spinal Stenosis; Spondylolisthesis; Spondylosis; Intervertebral Disk Displacement; Intervertebral Disk Degeneration; Spinal Diseases; Bone Diseases; Musculoskeletal Diseases; Spondylolysis

  10. 退变性腰椎间盘病外科治疗现状与研究%The present status of surgical treatment and research of degenerative lumbar disk disease

    Institute of Scientific and Technical Information of China (English)

    党耕町

    2002-01-01

    @@ 本期刊登有关脊柱疾患的论文9篇,其中5篇是关于腰椎间盘病的病理与手术治疗的研究.作者根据临床实践或实验研究中的问题,进行了系统地观察、分析、总结,得出结论并提出各自的观点. 退变性椎间盘病 (degenerative disk disease, DDD)是中老年人群中的常见病、多发病,是脊柱外科医生或骨科医生几乎每天都要处理的临床问题.

  11. Transdural epidurography in the diagnosis of lesions of the lumbar intervertebral disks

    Energy Technology Data Exchange (ETDEWEB)

    Matvienko, V.I.; Serikov, Yu.G.; Syuremov, M.N. (Rostovskij-na-Donu Meditsinskij Inst. (USSR))

    The anterior epidural space adjoining directly the posterior parts of the vertebral bodies, was examined with 8-12% solution of verografin in 140 patients with lumbar osteochodrosis. Of them 110 had been previously operated on. The use of low-concentration water-soluble iodine contrast agents makes it possible to avoid the stimulation of the epidural structures. X-ray appearance which is typical of protrusion and hernia of the intervertebral disks is described.

  12. Varus deformity of the left lower extremity causing degenerative lesion of the posterior horn of the left medial meniscus in a patient with Paget’s disease of bone

    Directory of Open Access Journals (Sweden)

    Al Kaissi, Ali

    2014-09-01

    Full Text Available [english] We report on a 42-year-old woman who presented with persistent pain in her left knee with no history of trauma. Sagittal T1-weighted MRI of the left knee showed discontinuity between the anterior and posterior horns of the left medial meniscus, causing effectively the development of degenerative lesion of the posterior horn. The latter was correlated to varus deformity of the left lower extremity associated with subsequent narrowing of the medial knee joint. The unusual craniofacial contour of the patient, the skeletal survey and the elevated serum alkaline phosphatase were compatible with the diagnosis of Paget’s disease of the bone. To alleviate the adverse effect of the mal-alignment of the left femur onto the left knee, corrective osteotomy of the left femoral diaphysis by means of fixators was performed. To the best of our knowledge this is the first clinical report describing the management and the pathological correlation of a unilateral varus deformity of the femoral shaft and degenerative lesions of the left knee in a patient with Paget’s disease of the bone.

  13. TU-C-12A-12: Differentiating Bone Lesions and Degenerative Joint Disease in NaF PET/CT Scans Using Machine Learning

    Energy Technology Data Exchange (ETDEWEB)

    Perk, T; Bradshaw, T; Muzahir, S; Jeraj, R [University of Wisconsin, Madison, Wisconsin (United States); Meyer, E [Case Western Reserve University School of Medicine, Cleveland, Ohio (United States)

    2014-06-15

    Purpose: [F-18]NaF PET can be used to image bone metastases; however, tracer uptake in degenerative joint disease (DJD) often appears similar to metastases. This study aims to develop and compare different machine learning algorithms to automatically identify regions of [F-18]NaF scans that correspond to DJD. Methods: 10 metastatic prostate cancer patients received whole body [F-18]NaF PET/CT scans prior to treatment. Image segmentation resulted in 852 ROIs, 69 of which were identified by a nuclear medicine physician as DJD. For all ROIs, various PET and CT textural features were computed. ROIs were divided into training and testing sets used to train eight different machine learning classifiers. Classifiers were evaluated based on receiver operating characteristics area under the curve (AUC), sensitivity, specificity, and positive predictive value (PPV). We also assessed the added value of including CT features in addition to PET features for training classifiers. Results: The training set consisted of 37 DJD ROIs with 475 non-DJD ROIs, and the testing set consisted of 32 DJD ROIs with 308 non-DJD ROIs. Of all classifiers, generalized linear models (GLM), decision forests (DF), and support vector machines (SVM) had the best performance. AUCs of GLM (0.929), DF (0.921), and SVM (0.889) were significantly higher than the other models (p<0.001). GLM and DF, overall, had the best sensitivity, specificity, and PPV, and gave a significantly better performance (p<0.01) than all other models. PET/CT GLM classifiers had higher AUC than just PET or just CT. GLMs built using PET/CT information had superior or comparable sensitivities, specificities and PPVs to just PET or just CT. Conclusion: Machine learning algorithms trained with PET/CT features were able to identify some cases of DJD. GLM outperformed the other classification algorithms. Using PET and CT information together was shown to be superior to using PET or CT features alone. Research supported by the Prostate

  14. Non degenerative disease in MRI cervical spine of symptomatic patients

    Directory of Open Access Journals (Sweden)

    Dan B Karki

    2016-01-01

    Full Text Available Background & Objectives: The most common etiology of neck pain is degenerative disc disease, however non-degenerative disease can be important cause of neck pain. This study aims to study the non-degenerative findings in cervical MRI in symptomatic patients with neck and radicular pain.Materials & Methods: The study was a institutional record based retrospective study performed for the duration of 3 years. MRI performed for patients with neck pain and/ or radiculopathy were reviewed. Patients with post operative findings were excluded from the study. Statistical analysis was done using SPSS 21.0.Results: A total of 721 MRI were performed for neck pain and radiculopathy, among which 91 (12.13% cases had non-degenerative changes. Most common non degenerative change was traumatic lesions followed by neoplastic lesions and syrinx. Traumatic lesions were more common in males as compared to females. Infection was more common in females as compared to males. C5 and C6 vertebrae were most common vertebra involved in trauma and infection. Some cases like signal change in spinal cord, and syrinx were also noted in our study.Conclusion: Non degenerative cause of neck pain were less common but important cause of neck pain. Traumatic lesions were the most common cause of non degenerative neck pain.Journal of College of Medical Sciences-Nepal, Vol.11(4 2015: 20-23

  15. Degenerative Nerve Diseases

    Science.gov (United States)

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  16. [Dysexecutive syndromes and degenerative diseases].

    Science.gov (United States)

    Pillon, B; Czernecki, V; Dubois, B

    2004-04-01

    A dysexecutive syndrome is observed not only in frontotemporal lobar degeneration, but also in subcortical degenerative diseases, and even in Alzheimer's disease whose lesions predominate in temporoparietal associative areas. The association between a dysexecutive syndrome and various cerebral localisations may be explained by the fact that cognitive and behavioral organisation recruits anatomofunctional frontostriatal and frontoparietal circuits. Both animal experimentation and human clinical observation argue in favour of a functional continuity and complementarity among these loops. The prefrontal cortex would be particularly needed in new situations, to inhibit old programs of action not adapted to the present context and to elaborate new ones; the basal ganglia would be rather required by the repetition of the situation to progressively transform the new program in routine. If we refer to Shallice model, we can hypothesize that optimal executive functions require the preservation not only of the Supervisory Attentional System, mainly dependent on the prefrontal cortex, but also of the Contention Scheduling, recruiting the basal ganglia, and of the Schemas of Action, represented in parietal and premotor areas. Therefore, the neuropsychological assessment of patients with degenerative diseases contributes to the understanding of the anatomofunctional architecture of executive functions.

  17. Short term outcome of posterior dynamic stabilization system in degenerative lumbar diseases

    Directory of Open Access Journals (Sweden)

    Mingyuan Yang

    2014-01-01

    Conclusion: Dynamic stabilization system treating lumbar degenerative disease showed clinical benefits with motion preservation of the operated segments, but does not have the significant advantage on motion preservation at adjacent segments, to avoid the degeneration of adjacent intervertebral disk.

  18. Degenerative cerebellar diseases and differential diagnoses; Degenerative Kleinhirnerkrankungen und Differenzialdiagnosen

    Energy Technology Data Exchange (ETDEWEB)

    Reith, W.; Roumia, S.; Dietrich, P. [Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar (Germany)

    2016-11-15

    Cerebellar syndromes result in distinct clinical symptoms, such as ataxia, dysarthria, dysmetria, intention tremor and eye movement disorders. In addition to the medical history and clinical examination, imaging is particularly important to differentiate other diseases, such as hydrocephalus and multi-infarct dementia from degenerative cerebellar diseases. Degenerative diseases with cerebellar involvement include Parkinson's disease, multiple system atrophy as well as other diseases including spinocerebellar ataxia. In addition to magnetic resonance imaging (MRI), nuclear medicine imaging investigations are also helpful for the differentiation. Axial fluid-attenuated inversion recovery (FLAIR) and T2-weighted sequences can sometimes show a signal increase in the pons as a sign of degeneration of pontine neurons and transverse fibers in the basilar part of the pons. The imaging is particularly necessary to exclude other diseases, such as normal pressure hydrocephalus (NPH), multi-infarct dementia and cerebellar lesions. (orig.) [German] Klinisch imponieren Kleinhirnsyndrome durch Ataxie, Dysarthrie, Dysmetrie, Intentionstremor und Augenbewegungsstoerungen. Neben der Anamnese und klinischen Untersuchung ist die Bildgebung v. a. wichtig um andere Erkrankungen wie Hydrozephalus und Multiinfarktdemenz von degenerativen Kleinhirnerkrankungen zu differenzieren. Zu den degenerativen Erkrankungen mit Kleinhirnbeteiligung gehoeren der Morbus Parkinson, die Multisystematrophie sowie weitere Erkrankungen einschliesslich der spinozerebellaeren Ataxien. Neben der MRT sind auch nuklearmedizinische Untersuchungen zur Differenzierung hilfreich. Axiale Fluid-attenuated-inversion-recovery(FLAIR)- und T2-gewichtete Sequenzen koennen mitunter eine Signalsteigerung im Pons als Ausdruck einer Degeneration der pontinen Neuronen und transversalen Bahnen im Brueckenfuss zeigen. Die Bildgebung ist aber v. a. notwendig, um andere Erkrankungen wie Normaldruckhydrozephalus

  19. Degenerative spine disorders in the context of clinical findings

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Michael [Institut fuer Radiologie und Neuroradiologie, Klinikum Aschaffenburg, Am Hasenkopf 1, 63739 Aschaffenburg (Germany) and Abteilung fuer Neuroradiologie, Universitaetsklinikum Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany)]. E-mail: michael.freund@klinikum-aschaffenburg.de; Sartor, Klaus [Abteilung fuer Neuroradiologie, Universitaetsklinikum Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg (Germany)

    2006-04-15

    Hardly any other structure in the human body is held responsible for so many complaints, pain, and costs as the spine and its degenerative disorders. In the following article, the role of imaging procedures in diagnosing disorders of the spine is presented. Due to the fact that disk herniation represents the most frequent cause for degenerative disorders the anatomy of the intervertebral disk and the pathology of the entities that can cause diseases of the disks are described. In particular, the authors focus on the significance of radiological findings with respect to patient history, subjective symptoms, and objective clinical findings. In addition to presenting the technical procedures and their indications and contraindications also practical tips and tricks in conducting these examinations are presented in this paper.

  20. Degenerative spinal disease in large felids.

    Science.gov (United States)

    Kolmstetter, C; Munson, L; Ramsay, E C

    2000-03-01

    Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10-19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.

  1. Falls in degenerative cerebellar ataxias

    NARCIS (Netherlands)

    van de Warrenburg, Bart P C; Steijns, Janneke A G; Munneke, Marten; Kremer, Berry P H; Bloem, Bastiaan R

    2005-01-01

    We retrospectively and prospectively assessed the frequency and characteristics of falls in patients with degenerative cerebellar ataxias. The results show that falls occur very frequently in patients with degenerative cerebellar ataxias and that these falls are serious and often lead to injuries or

  2. Degenerative myelopathy in dogs

    Directory of Open Access Journals (Sweden)

    Nikolovski Goran

    2010-05-01

    Full Text Available One of the chronic progressive disorders of the spinal cord in dogs is the degenerative myelopathy (DM. The most predisposed age in dog is 5 to 14 years, while rarely noted in younger, there is no gender predisposition. This disorder most commonly appears in dogs of the German shepherd breed, but it can appear in other breeds too. The main changes about this disease are degeneration of the myelin, especially in the thoracic-lumbar segments of the spinal cord and the dorsal nerve roots. The progression of the disease is slow and can last months to years. Undoubtedly, diagnosis is made by examinations of the CSF and establishing elevated level of protein segments.

  3. [Degenerative adult scoliosis].

    Science.gov (United States)

    García-Ramos, C L; Obil-Chavarría, C A; Zárate-Kalfópulos, B; Rosales-Olivares, L M; Alpizar-Aguirre, A; Reyes-Sánchez, A A

    2015-01-01

    Adult scoliosis is a complex three-dimensional rotational deformity of the spine, resulting from the progressive degeneration of the vertebral elements in middle age, in a previously straight spine; a Cobb angle greater than 10° in the coronal plane, which also alters the sagittal and axial planes. It originates an asymmetrical degenerative disc and facet joint, creating asymmetrical loads and subsequently deformity. The main symptom is axial, radicular pain and neurological deficit. Conservative treatment includes drugs and physical therapy. The epidural injections and facet for selectively blocking nerve roots improves short-term pain. Surgical treatment is reserved for patients with intractable pain, radiculopathy and/ or neurological deficits. There is no consensus for surgical indications, however, it must have a clear understanding of the symptoms and clinical signs. The goal of surgery is to decompress neural elements with restoration, modification of the three-dimensional shape deformity and stabilize the coronal and sagittal balance.

  4. Peripheral degenerative joint diseases

    Directory of Open Access Journals (Sweden)

    Nilzio Antonio da Silva

    2008-03-01

    Full Text Available Osteoarthritis, a degenerative joint disease, is the most commonrheumatic disorder mainly in a geriatric population. Manifestationsare pain, stiffness and functional loss in the affected joint.According to etiology it is classifi ed as primary (or idiopathicand secondary. Some risk factors for disease development aregenetics, race, age, sex, obesity, occupational activities andarticular biomechanics. Pathogenesis is the same for any cause orlocalization, being catabolic alterations, with synthesis, inhibitionand reparing intent of the cartilage matrix. Metalloproteinases andcytokines (IL-1,IL-6,TNF-α actions promote infl ammatory reactionand cartilage degradation. Pain, the most important symptom,does not correlate with radiologic fi ndings. Peripheral osteoarthritisoccurs predominantly in the knee, hip and hand. Diagnosis is basedon clinical features, laboratorial tests and radiological changes.Rheumatological associations’ guidelines for treatment includenon-pharmacologic (education, physiotherapy, assistive devices,and pharmacologic (analgesics, anti-infl ammatory drugs therapyand surgery. Arthroplasty seems to work better than medicines, butshould be used if other treatments have failed.

  5. MRI of degenerative cysts of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Khalatbari, K. [Department of MRI, Iran Gamma Knife Centre, Iran University of Medial Sciences-Kamrani Charity Foundation, Tehran (Iran, Islamic Republic of)], E-mail: khalatbarik@yahoo.com; Ansari, H. [Department of Orthopaedics, Rassoul Akram University Hospital, Tehran (Iran, Islamic Republic of)

    2008-03-15

    Degenerative cysts of the lumbar spine encompass a heterogeneous group of cystic lesions that are presumed to share a common aetiology. Some of these cysts may be incidental findings, whereas others may produce acute or chronic symptoms. These cysts have been categorized using various combinations of topographic and pathological characteristics and by their attachment to or communication with a specific spinal structure.

  6. Degenerative spine disease : pathologic findings in 985 surgical specimens.

    Science.gov (United States)

    Pytel, Peter; Wollmann, Robert L; Fessler, Richard G; Krausz, Thomas N; Montag, Anthony G

    2006-02-01

    A number of pathologic changes have been reported in spinal surgery specimens. The frequency of many of these is not well defined. We retrospectively reviewed the histologic features of 985 extradural spinal surgery specimens. Of the cases, 1.6% were identified clinically as synovial cysts. In addition, synovial tissue was seen in another 5.3% of cases, often embedded within disk material. Neovascularization of disk tissue was present in 8.1% of cases, chondrocyte clusters in 18.3%, and calcium pyrophosphate crystals in 2.8%, predominantly within disk material. With the exception of crystal deposits, all of these changes were significantly more common in the lumbar spine. A better understanding of cell-based degenerative changes will become essential with increasing research into cell-based therapies for spinal disk disease. We report data on the frequency of different pathologic changes and describe synovial metaplasia as a reactive change not previously reported.

  7. CT findings of isthmic spondylolisthesis and degenerative spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Suk Kyeong; Cho, Seong II; Chung, Gyung Ho; Lee, Sang Yong; Han, Young Min; Sohn, Myung Hee; Kim, Chong Soo; Choi, Ki Chul [Chonbuk National Univ. College of Medicine, Chonju (Korea, Republic of)

    1996-01-01

    CT evaluate the finding useful for differential diagnosis and associated abnormalities of isthmic spondylolisthesis and degenerative spondylolisthesis on CT. We reviewed retrospectively the CT images of 164 patients who were diagnosed spondylolisthesis. One hundred twelve patients had isthmic spondylolisthesis and 52 patients had degenerative spondylolisthesis. Isthmic spondylolisthesis most frequently occurred at L5. The degree of anterior displacement was grade I and II. The defect had a horizontal plane, an irregular surface, a sclerotic margin, and protruding hypertrophic bony spur in the spinal canal. The most frequently associated structural abnormality was a herniated nucleus pulposus at the upper level of the defect. Degenerative spondylolisthesis most frequently occurred at L4-5 and were grade I. The degenerative facet joint had a vertical plane, a hypertrophic bony spur, and a vacuum facet phenomenon. We frequently detected a pseudobulging disk. The most frequently associated structural abnormality was a herniated nucleus pulposus at the level of the displacement. In spondylolisthesis, the findings in CT were valuable for differential diagnosis of isthmic and degenerative types and the detection of associated symptomatic abnormalities.

  8. Degenerative lumbosacral stenosis in dogs

    NARCIS (Netherlands)

    Suwankong, N.

    2007-01-01

    Degenerative lumbosacral stenosis (DLS) is now recognized as a significant cause of caudal lumbar pain and pelvic limb lameness in dogs. The condition includes lumbosacral intervertebral disc degeneration and protrusion, spondylosis deformans, sclerosis of the vertebral end plates, osteoarthrosis of

  9. Rotary deformity in degenerative spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Gwon; Kim, Jeong; Kho, Hyen Sim; Yun, Sung Su; Oh, Jae Hee; Byen, Ju Nam; Kim, Young Chul [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    1994-05-15

    We studied to determine whether the degenerative spondylolisthesis has rotary deformity in addition to forward displacement. We have made analysis of difference of rotary deformity between the 31 study groups of symptomatic degenerative spondylolisthesis and 31 control groups without any symptom, statistically. We also reviewed CT findings in 15 study groups. The mean rotary deformity in study groups was 6.1 degree(the standard deviation is 5.20), and the mean rotary deformity in control groups was 2.52 degree(the standard deviation is 2.16)(p < 0.01). The rotary deformity can be accompanied with degenerative spondylolisthesis. We may consider the rotary deformity as a cause of symptomatic degenerative spondylolisthesis in case that any other cause is not detected.

  10. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, J B; Juhl, C B; Roos, E M;

    2015-01-01

    OBJECTIVE: To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURES: Pain and physical function....... RESULTS: The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  11. Spinopelvic balance evaluation of patients with degenerative spondylolisthesis L4L5 and L4L5 herniated disc who underwent surgery

    Directory of Open Access Journals (Sweden)

    Viviane Regina Hernandez Nunes

    Full Text Available ABSTRACT OBJECTIVE: To correlate spinopelvic balance with the development of degenerative spondylolisthesis and disk herniation. METHODS: This was a descriptive retrospective study that evaluated 60 patients in this hospital, 30 patients with degenerative spondylolisthesis at the L4-L5 level and 30 with herniated disk at the L4-L5 level, all of whom underwent Surgical treatment. RESULTS: Patients with lumbar disk herniation at L4-L5 level had a mean tilt of 8.06, mean slope of 36.93, and mean PI of 45. In patients with degenerative spondylolisthesis at the L4-L5 level, a mean tilt of 22.1, mean slope of 38.3, and mean PI of 61.4 were observed. CONCLUSION: This article reinforces the finding that the high mean tilt and PI are related to the onset of degenerative spondylolisthesis, and also concluded that the same angles, when low, increase the risk for disk herniation.

  12. Galaxy Disks

    NARCIS (Netherlands)

    van der Kruit, P. C.; Freeman, K. C.

    The disks of disk galaxies contain a substantial fraction of their baryonic matter and angular momentum, and much of the evolutionary activity in these galaxies, such as the formation of stars, spiral arms, bars and rings, and the various forms of secular evolution, takes place in their disks. The

  13. Adult degenerative and senile degenerative hyperostosis triangularis ilii

    Energy Technology Data Exchange (ETDEWEB)

    Nebel, G.; Hering, L.; Lingg, G.

    1981-10-01

    A randomised study of 2000 patients (1000 males, 1000 females) revealed two forms of the triangular hyperostosis of the ilium in female patients. The hyperostosis triangularis ilii, HTI, is also known as osteitis condensans. One form of HTI concerning women under the age of 50 is called the adult generative HTI, the other beyond the age of 50 senile degenerative HTI. These two forms are not evident in male patients. The 3.05% incidence of HTI in adults appeared to be higher than presumed till now. The sex incidence male/female of 1:1.6 diverges considerably from preceding investigations. Histomorphological studies of two autopsies of cases of senile degenerative HTI revealed no signs of inflammation. Statistical correlations of HTI with other chronic diseases of the pelvis and hip could doubtlessly and generally be established only for osteoarthrosis of the sacro-iliac joints in females beyond the age of 50 and in males as a matter of principle.

  14. Computed tomography in lumbar degenerative disease

    Energy Technology Data Exchange (ETDEWEB)

    Isu, Toyohiko; Miyasaka, Kazuo; Abe, Satoru; Takei, Hidetoshi; Kaneda, Kiyoshi (Hokkaido Univ., Sapporo (Japan). School of Medicine)

    1984-02-01

    We reported the 18 patients which underwent surgical exploration and reviewed these CT findings. Method All CT scans were obtained on Somatom II, high resolution CT scanner, with the patient in the supine position. A lateral localizer image (Topogram) was used to select the appropriate intervertebral disk space. The slice thickness was 4 mm. Results 1) CT findings in lumbar degenerative diseases include bony canal stenosis (central canal stenosis, narrowed lateral recess), soft tissue abnormalities (herniated nucleus pulposus, bulging annulus, hypertrophy and/or ossification of ligamentum flavum, no delineation of nerve root in lateral recess), and spinal instability (spondylolisthesis, vacuum phenomenon). 2) The above three factors contribute to narrowing of spinal canal. 3) No delineation of nerve root or soft tissue replacement of epidural fat in lateral recess suggests that the nerve root may be compressed by some factors. 4) Herniated nucleus pulposus may cause nerve root compression with or without canal stenosis. Conclusion This study revealed that the CT findings correlated closely with the surgical findings and the site of nerve root compression could be determined.

  15. Cancer--a degenerative disorder?

    Science.gov (United States)

    Rew, D A

    1998-10-01

    Cancer is primarily a disease of ageing epithelia, and of ageing individuals. We now possess detailed insights into the changes in cell regulatory genes and DNA repair systems which accumulate with time and which manifest in malignancy. These demonstrate how cancer is frequently characterized by degenerative change in the genotype, from the most subtle base pair mutations to gross aneuploidy, and by deterioration in cell and tissue regulatory control, be it of proliferation, programmed cell death or signalling. Cancer may thus be as much a phenomenon of loss or deterioration of normal genomic control as of the acquisition of new, neoplastic functions. This distinction may be more than semantic, not least because it governs our approach to the search for therapeutic strategies. This essay considers the concept of cancer as a degenerative disease and its implications, and proposes the neologism aldoplasia to describe this phenomenon of cancer biology.

  16. Arthroscopic surgery for degenerative knee

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Juhl, C B; Roos, E M

    2015-01-01

    . DATA SOURCES: Systematic searches for benefits and harms were carried out in Medline, Embase, CINAHL, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) up to August 2014. Only studies published in 2000 or later were included for harms. ELIGIBILITY CRITERIA FOR SELECTING...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

  17. Galaxy Disks

    CERN Document Server

    van der Kruit, P C

    2011-01-01

    The formation and evolution of galactic disks is particularly important for understanding how galaxies form and evolve, and the cause of the variety in which they appear to us. Ongoing large surveys, made possible by new instrumentation at wavelengths from the ultraviolet (GALEX), via optical (HST and large groundbased telescopes) and infrared (Spitzer) to the radio are providing much new information about disk galaxies over a wide range of redshift. Although progress has been made, the dynamics and structure of stellar disks, including their truncations, are still not well understood. We do now have plausible estimates of disk mass-to-light ratios, and estimates of Toomre's $Q$ parameter show that they are just locally stable. Disks are mostly very flat and sometimes very thin, and have a range in surface brightness from canonical disks with a central surface brightness of about 21.5 $B$-mag arcsec$^{-2}$ down to very low surface brightnesses. It appears that galaxy disks are not maximal, except possibly in ...

  18. 综合治疗退行性膝骨关节炎65例%Comprehensive treatment of 65 cases on degenerative gonarthritis

    Institute of Scientific and Technical Information of China (English)

    黄乐天; 杨丽坤; 何伟

    2003-01-01

    @@ BACKGROUND:Single method such as Non sternondal antiinflammatory drugs(NSAID),intraarticular injection of natrium hyalunate,needle relaxing,physical treatment,functional exercises is often reported to treat degenerative gonarthritis.But multiple lesions of knee in degenerative gonarthritis indicate that single methods have some limit in treatment of deganerative gonarthritis.

  19. MR imaging of the spine: trauma and degenerative disease

    Energy Technology Data Exchange (ETDEWEB)

    Wilmink, J.T. [Department of Radiology, University Hospital Maastricht (Netherlands)

    1999-09-01

    The purpose of this paper is to discuss the capabilities and drawbacks of MR imaging in patients with trauma to the spine and degenerative spinal conditions. In spinal trauma MR imaging is secondary to plain X-ray films and CT because of the greater availability and ease of performance of these techniques and their superior capability for detecting vertebral fractures. Magnetic resonance imaging is useful for detecting ligamentous ruptures and intraspinal mass lesions such as hematoma, and for assessing the state of the spinal cord and prognosis of a cord injury. In degenerative spinal disease the necessity is emphasized of critically evaluating the clinical relevance of any abnormal feature detected, as findings of degenerative pathology are common in individuals without symptoms. Magnetic resonance myelography permits rapid and accurate assessment of the state of the lumbar nerve roots (compressed or not). In the cervical region the quality of the myelographic picture is often degraded in patients with a narrow spinal canal. (orig.) With 10 figs., 14 refs.

  20. Intraosseouss degenerative cyst of the axis approached via transcervical extrapharyngeal avenue

    Directory of Open Access Journals (Sweden)

    Gustavo Rassier Isolan

    2012-01-01

    Full Text Available Intraosseous degenerative cysts (IDC of the cervical spine are rare. IDC within C2 have been reported in three articles only. We report a patient with neck pain due to a IDC within C2. We discuss the differential diagnosis of these lesions and the surgical approaches to reach this complex anatomical region.

  1. Stereotypic behaviors in degenerative dementias.

    Science.gov (United States)

    Prioni, S; Fetoni, V; Barocco, F; Redaelli, V; Falcone, C; Soliveri, P; Tagliavini, F; Scaglioni, A; Caffarra, P; Concari, L; Gardini, S; Girotti, F

    2012-11-01

    Stereotypies are simple or complex involuntary/unvoluntary behaviors, common in fronto-temporal dementia (FTD), but not studied in other types of degenerative dementias. The aim was to investigate stereotypy frequency and type in patients with FTD, Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and Parkinson's disease with dementia (PDD) in a multicenter observational study; and to investigate the relation of stereotypies to cognitive, behavioral and motor impairment. One hundred fifty-five consecutive outpatients (45 AD, 40 FTD, 35 PSP and 35 PDD) were studied in four hospitals in northern Italy. Stereotypies were examined by the five-domain Stereotypy Rating Inventory. Cognition was examined by the Mini Mental State and Frontal Assessment Battery, neuropsychiatric symptoms by the Neuropsychiatric Inventory, and motor impairment and invalidity by the Unified Parkinson's Disease Rating Scale part III, and activities of daily living. Stereotypies were present in all groups. FTD and PDD had the greatest frequency of one-domain stereotypies; FTD also had the greatest frequency of two-or-more domain stereotypies; movement stereotypies were the most common stereotypies in all groups. AD patients had fewer stereotypies than the other groups. Stereotypies are not exclusive to FTD, but are also fairly common in PSP and PDD, though less so in AD. Stereotypies may be underpinned by dysfunctional striato-frontal circuits, known to be damaged in PSP and PDD, as well as FTD.

  2. GUIDELINES FOR TREATMENT OF DEGENERATIVE LUMBAR SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    CARMEN YOSSALETH BRICEÑO-GONZÁLEZ

    Full Text Available ABSTRACT Objectives: To determine the standard of treatment of degenerative lumbar spondylolisthesis in its different clinical presentations in UMAE Dr. Victorio de la Fuente Narváez. Methods: Six cases found in the literature were presented to 36 experts in spine surgery, along with treatment options, to thereby obtain a standard prescription for the treatment of degenerative lumbar spondylolisthesis. Analytical observational cross-sectional descriptive study. Results: It was found that the treatment of choice in cases of degenerative lumbar spondylolisthesis with axial symptoms is conservative. The surgical treatment of choice for both stable and unstable patients with radiculopathy and/or claudication is decompression + posterolateral graft + transpedicular instrumentation + discectomy (graft. Conclusions: We managed to define the degenerative lumbar spondylolisthesis treatment guidelines in our unit, which can serve as a basis for the development of a clinical practice guide.

  3. ?Lumbar Degenerative Kyphosis? Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception

    OpenAIRE

    Lee, Chang-Hyun; Chung, Chun Kee; Jang, Jee-Soo; Kim, Sung-Min; Chin, Dong-Kyu; Lee, Jung-Kil

    2017-01-01

    Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal...

  4. Situación actual de la cirugía de la columna vertebral degenerativa aplicada al manejo del dolor lumbar crónico: Estenosis de canal. Discopatia degenerativa, resultados basados en la evidencia científica Present state of degenerative back surgery and its implications in the management of chronic lumbar pain, canal stenosis and degenerative disk disease: Evidence based outcomes

    Directory of Open Access Journals (Sweden)

    F. J. Robaina

    2006-04-01

    there is not any correctly done study that compares the conservative and surgical treatments in the manegement of her-niated lumbar disc. For that reason , we are still triying to find new treatment options in the nonsurgical field of her-niated lumbar disc. When we analize the published results of the spine surgery, we must beard in mind what have been call in the "American Stock and Excahnge" "the bubble of spine surgery". The scientific literature does not show clear evidence in the cost-benefict studies of most instrumented surgical interventions of the spine compare with the conservative treatments. It has not been yet demostrated that fusion surgery and disc replacement are better options than the conservtive treatment. It´s necesary to point out that at present "there are relationships between the industry and back pain and there is also an industry of the back pain" . Nontheless, the "market of the spine surgery" is growing up because patients are demanding solutions for their back problems. The tide of scientific evidence seams to go against of the spinal fusions in the degenerative disc disease, discogenic pain and inespecific back pain. After decades of technological advances in this field, the results of spinal fusions are mediocre. Recent epidemiological studies show that "spinal fusion must be accepted as a non proved or experimental method for the treatment of back pain". The surgical literature on spinal fusion published in the last 20 years following the Cochrane’s method stablish that: 1- this is at least incomplete, not realiable and careless; 2- the instrumentation seems to sligthy increase the fusion rate ; 3- the instrumentation doesn’t improve the clinical results in general, lacking studies in subgroups of patients. We still are needing randomized studies to compare the surgical results with the natural history of the disease, the pacebo effect, or the conservative treatment. The European Guidelines for lumbar chronic pain management shows a

  5. Low back pain and degenerative disc disease

    Directory of Open Access Journals (Sweden)

    Jandrić Slavica

    2006-01-01

    Full Text Available Introduction. Various clinical conditions can cause low back pain, and in most cases it is of a degenerative origin. Degenerative disc disease is a common condition which affects young to middle-aged men and women equally. Changes in the mechanical properties of the disc lead to degenerative arthritis in the intervertebral joints, osteophytes, and narrowing the intervertebral foramen or the spinal canal. Pathophysiology. Degenerative cascade, described by Kirkaldy-Willis, is the widely accepted pathophysiologic model describing the degenerative process as it affects the lumbar spine in 3 phases. Diagnosis. There are two forms of low back pain secondary to degenerative disc disease: a lumbalgia and b lumbar radiculopathy. Limitation of movement, problems with balance, pain, loss of reflexes in the extremities, muscle weakness, loss of sensation or other signs of neurological damage can be found on physical examination. For accurate diagnosis, it is often necessary to combine clinical examination and sophisticated technology. Treatment. Coservative treatment consists of rest, physical therapy, pharmacological therapy and injection therapy. Physical rehabilitation with active patient participation is a key approach to treatment of patients with discogenic pain. Physical therapy, occupational therapy and kinesitherapy are important for improving muscle strength, endurance, and flexibility. Disc surgery is performed if surgical intervention is required. .

  6. Neuro degenerative diseases: clinical concerns; Les maladies neuro-degeneratives: problemes cliniques

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, V. [Hopitaux Universitaires de Geneve (HUG), Unite de Neuroimagerie, Dept. de Psychiatrie (Switzerland)

    2005-04-15

    Idiopathic Parkinson's disease (PD) and Alzheimer's disease (AD) are the main neuro-degenerative diseases (NDDs) seen clinically. They share some common clinical symptoms and neuro-pathological findings. The increase of life expectancy in the developed countries will inevitably contribute to enhance the prevalence of these diseases. Behavioral disorders, common in NDDs, will produce major care management challenges. Idiopathic Parkinson's disease corresponds to a histopathological diagnosis, based on the observation of a de-pigmentation and a neuronal loss in the substantia nigra, as well as on the presence of intra-neuronal inclusion bodies. AD is insidious with slowly progressive dementia in which the decline in memory constitutes the main complaint. The diagnosis of definite AD requires the presence of clinical criteria as well as the histopathological confirmation of brain lesions. The two main lesions are the presence of senile plaques and neuro-fibrillary tangles. Positron emission tomography (PET) explores cerebral metabolism and neurotransmitter kinetics in NDDs using principally [{sup 18}F]-deoxyglucose and [{sup 18}F]-dopa. Nigrostriatal dopaminergic function is altered in PD, as evidenced by the low uptake of [{sup 18}F]-dopa in the posterior putamen as compared to anterior putamen and caudate nucleus. In contrast, [{sup 18}F]-dopa uptake is equally depressed in all striatal structures in progressive supra-nuclear palsy. Regional glucose metabolism at rest is preserved in elderly once cerebral atrophy is taken into account. On the contrary, glucose metabolism is globally reduced in AD, with marked decrease in the parietal and temporal regions. PET has proved to be useful to study in vivo neurochemical processes in patients suffering from NDDs. The potential of this approach is still largely unexploited, and depends on new ligand production to establish early diagnosis and treatment follow-up. (author)

  7. Location and Initiation of Degenerative Rotator Cuff Tears

    Science.gov (United States)

    Kim, H. Mike; Dahiya, Nirvikar; Teefey, Sharlene A.; Middleton, William D.; Stobbs, Georgia; Steger-May, Karen; Yamaguchi, Ken; Keener, Jay D.

    2010-01-01

    cuff lesions, degenerative rotator cuff tears. PMID:20439653

  8. Common surgical complications in degenerative spinal surgery.

    Science.gov (United States)

    Papadakis, Michael; Aggeliki, Lianou; Papadopoulos, Elias C; Girardi, Federico P

    2013-04-18

    The rapid growth of spine degenerative surgery has led to unrelenting efforts to define and prevent possible complications, the incidence of which is probably higher than that reported and varies according to the region of the spine involved (cervical and thoracolumbar) and the severity of the surgery. Several issues are becoming progressively clearer, such as complication rates in primary versus revision spinal surgery, complications in the elderly, the contribution of minimally invasive surgery to the reduction of complication rate. In this paper the most common surgical complications in degenerative spinal surgery are outlined and discussed.

  9. Secure Disk Mixed System

    Directory of Open Access Journals (Sweden)

    Myongchol Ri

    2013-01-01

    Full Text Available We propose a disk encryption method, called Secure Disk Mixed System (SDMS in this paper, for data protection of disk storages such as USB flash memory, USB hard disk and CD/DVD. It is aimed to solve temporal and spatial limitations of existing disk encryption methods and to control security performance flexibly according to the security requirement of system.

  10. D-penicillamine induced degenerative dermopathy

    Directory of Open Access Journals (Sweden)

    Sujay Khandpur

    2015-01-01

    Full Text Available D-penicillamine interferes with elastin and collagen metabolism and produces several cutaneous and multi-systemic side-effects. We present two cases of Wilson′s disease who on long-term penicillamine therapy developed drug-induced degenerative dermopathy manifesting as skin fragility over pressure sites and cutis laxa-like changes.

  11. Degenerative Pathways of Lumbar Motion Segments

    DEFF Research Database (Denmark)

    Jensen, Rikke K.; Kjaer, Per; Jensen, Tue S.

    2016-01-01

    BACKGROUND: Magnetic resonance imaging (MRI) is used to identify spinal pathoanatomy in people with persistent low back pain. However, the clinical relevance of spinal degenerative MRI findings remains uncertain. Although multiple MRI findings are almost always present at the same time, research ...

  12. Avaliação dos resultados clínicos após cirurgia descompressiva em cães com doença de disco intervertebral Evaluation of clinical results of decompressive surgery in dogs with degenerative disk disease

    Directory of Open Access Journals (Sweden)

    M.V.B. Arias

    2007-12-01

    Full Text Available Avaliaram-se os resultados clínicos após realização de cirurgia descompressiva em 45 cães com doença do disco intervertebral cervical ou toracolombar. Após a cirurgia, 35 cães (77,8% recuperaram-se totalmente, oito (17,8% parcialmente e dois (4,4% não apresentaram alteração do quadro inicial. Em oito cães com paraplegia e perda da sensibilidade dolorosa profunda houve completa melhora do quadro clínico, com recuperação total em 62,5% dos casos. Em quatro cães com tetraparesia, a cirurgia foi eficaz. A cirurgia descompressiva (slot cervical e hemilaminectomia toracolombar, com a retirada do material do disco do interior do canal vertebral, foi uma forma efetiva de gerar melhora do quadro funcional.Clinical results after decompressive surgery were evaluated in 45 dogs with cervical or thoracolumbar intervertebral disk disease. After surgery, 35 dogs recovered totally, eight (17.8% partially, and two (4.4% did not present any change in clinical findings. Eight dogs with paraplegy and loss of deep pain perception showed improvement, with total recovering in 62.5% of cases. Surgery was effective in four dogs with tetraparesy. Decompressive surgery (cervical slot or hemilaminectomy, with removal of disk material from inside the vertebral canal, was an effective form to produce functional improvement in dogs with this disease.

  13. MR imaging of degenerative disc disease

    Energy Technology Data Exchange (ETDEWEB)

    Farshad-Amacker, Nadja A., E-mail: nadja.farshad@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Zurich (Switzerland); Farshad, Mazda [Department of Orthopaedic Surgery, Balgrist University Hospital, Zurich (Switzerland); Winklehner, Anna; Andreisek, Gustav [Institute of Diagnostic and Interventional Radiology, University Hospital of Zurich, Zurich (Switzerland)

    2015-09-15

    Highlights: • This systematic literature review summarizes the current knowledge on MR imaging in degenerative disc disease. • Different classification systems for segmental spine degeneration are summarized. • It outlines the diagnostic limitations of MR imaging. - Abstract: Magnet resonance imaging (MRI) is the most commonly used imaging modality for diagnosis of degenerative disc disease (DDD). Lack of precise observations and documentation of aspects within the complex entity of DDD might partially be the cause of poor correlation of radiographic findings to clinical symptoms. This literature review summarizes the current knowledge on MRI in DDD and outlines the diagnostic limitations. The review further sensitizes the reader toward awareness of potentially untended aspects of DDD and the interaction of DDD and endplate changes. A summary of the available classifications for DDD is provided.

  14. Physiochemical basis of human degenerative disease

    Directory of Open Access Journals (Sweden)

    Zeliger Harold I.

    2015-03-01

    Full Text Available The onset of human degenerative diseases in humans, including type 2 diabetes, cardiovascular disease, neurological disorders, neurodevelopmental disease and neurodegenerative disease has been shown to be related to exposures to persistent organic pollutants, including polychlorinated biphenyls, chlorinated pesticides, polybrominated diphenyl ethers and others, as well as to polynuclear aromatic hydrocarbons, phthalates, bisphenol-A and other aromatic lipophilic species. The onset of these diseases has also been related to exposures to transition metal ions. A physiochemical mechanism for the onset of degenerative environmental disease dependent upon exposure to a combination of lipophilic aromatic hydrocarbons and transition metal ions is proposed here. The findings reported here also, for the first time, explain why aromatic hydrocarbons exhibit greater toxicity than aliphatic hydrocarbons of equal carbon numbers.

  15. [Pharmacotherapy of degenerative joint diseases in dogs].

    Science.gov (United States)

    Klee, S; Ungemach, F R

    1998-02-01

    The pharmacological treatment of degenerative joint diseases is restricted essentially to the alleviation of acute symptoms of activated arthropathies. Suitable compounds are the non-steroidal and steroidal antiinflammatory drugs, which however do not allow long-term therapy due to their overall catabolic effects on cartilage metabolism. Since causally acting drugs are not available, the progressive course of the disease cannot be prevented so far. Natural components of the cartilage's matrix, being recommended as so-called chondroprotective drugs, do not fulfill the expectation of a remission of the degenerative process. Indeed, regarding the necessity of multiple local applications of these drugs, they are not superior to antiinflammatory drugs. Provided careful dosing and surveillance of untoward gastrointestinal effects, non-steroidal antiinflammatory agents still are the drugs of first choice.

  16. Cervical myelopathy due to degenerative spondylolisthesis

    OpenAIRE

    Koakutsu, Tomoaki; Nakajo, Junko; Morozumi, Naoki; Hoshikawa, Takeshi; Ogawa, Shinji; Ishii, Yushin

    2011-01-01

    Objective To investigate clinical-radiological features of cervical myelopathy due to degenerative spondylolisthesis (DSL). Methods A total of 448 patients were operated for cervical myelopathy at Nishitaga National Hospital between 2000 and 2003. Of these patients, DSL at the symptomatic disc level was observed in 22 (4.9%) patients. Clinical features were investigated by medical records, and radiological features were investigated by radiographs. Results Disc levels of DSL were C3/4 in 6 ca...

  17. Surgical Treatment of Adult Degenerative Scoliosis

    OpenAIRE

    Cho, Kyu-Jung; Kim, Young-tae; Shin, Sang-hyun; Suk, Se-Il

    2014-01-01

    The rapid increase of elderly population has resulted in increased prevalence of adult scoliosis. Adult scoliosis is divided into adult idiopathic scoliosis and adult degenerative scoliosis. These two types of scoliosis vary in patient age, curve pattern and clinical symptoms, which necessitate different surgical indications and options. Back pain and deformity are major indications for surgery in adult idiopathic scoliosis, whereas radiating pain to the legs due to foraminal stenosis is what...

  18. Dynamic high-resolution sonography compared to magnetic resonance imaging for diagnosis of temporomandibular joint disk displacement.

    Science.gov (United States)

    Habashi, Hadeel; Eran, Ayelet; Blumenfeld, Israel; Gaitini, Diana

    2015-01-01

    The purpose of this study was to determine the value of dynamic high-resolution sonography for evaluation of temporomandibular joint (TMJ) disk displacement compared to magnetic resonance imaging (MRI) with the mouth closed and during the maximal mandibular range of motion. Dynamic high-resolution sonography with the mouth closed and during the maximal mandibular range of motion was performed on 39 consecutive patients (78 joints; 13 male and 26 female; age range, 18-77 years; mean age ± SD, 37.23 ± 16.26 years) with TMJ disorders. A TMJ MRI study was performed 1 to 7 days after sonography. We searched for signs of disk displacement and findings compatible with degenerative joint disease. Both studies were performed and interpreted independently by blinded operators. Magnetic resonance imaging depicted 22 normal joints (28.2%), 21 (26.9%) with anterior disk displacement with reduction, 15 (19.2%) with anterior disk displacement without reduction, and 20 (25.6%) with degenerative disease. Sonography depicted 30 normal joints (38.5%), 22 (28.2%) with anterior disk displacement with reduction, 12 (15.4%) with anterior disk displacement without reduction, and 14 (17.9%) with degenerative disease. The overall sensitivity, specificity, and accuracy of sonography for diagnosis of disk displacement were 74.3%, 84.2%, and 77.7%, respectively. The sensitivity, specificity, and accuracy for diagnosis of disk displacement with reduction were 78.6%, 66.7%, and 73.0%, and the values for diagnosis of disk displacement without reduction were 66.7%, 78.6%, and 73.0%. Dynamic high-resolution sonography is a potential imaging method for diagnosis of TMJ disk displacement and degenerative diseases. Further studies are needed to make dynamic high-resolution sonography the first-line test for diagnosis of TMJ disk displacement. © 2015 by the American Institute of Ultrasound in Medicine.

  19. Galaxy Disks are Submaximal

    NARCIS (Netherlands)

    Bershady, Matthew A.; Martinsson, Thomas P. K.; Verheijen, Marc A. W.; Westfall, Kyle B.; Andersen, David R.; Swaters, Rob A.

    2011-01-01

    We measure the contribution of galaxy disks to the overall gravitational potential of 30 nearly face-on intermediate-to-late-type spirals from the DiskMass Survey. The central vertical velocity dispersion of the disk stars (sigma(disk)(z,R=0)) is related to the maximum rotation speed (V-max) as sigm

  20. Consensus Paper: Management of Degenerative Cerebellar Disorders

    Science.gov (United States)

    Ilg, W.; Bastian, A. J.; Boesch, S.; Burciu, R. G.; Celnik, P.; Claaßen, J.; Feil, K.; Kalla, R.; Miyai, I.; Nachbauer, W.; Schöls, L.; Strupp, M.; Synofzik, M.; Teufel, J.

    2015-01-01

    Treatment of motor symptoms of degenerative cerebellar ataxia remains difficult. Yet there are recent developments that are likely to lead to significant improvements in the future. Most desirable would be a causative treatment of the underlying cerebellar disease. This is currently available only for a very small subset of cerebellar ataxias with known metabolic dysfunction. However, increasing knowledge of the pathophysiology of hereditary ataxia should lead to an increasing number of medically sensible drug trials. In this paper, data from recent drug trials in patients with recessive and dominant cerebellar ataxias will be summarized. There is consensus that up to date, no medication has been proven effective. Aminopyridines and acetazolamide are the only exception, which are beneficial in patients with episodic ataxia type 2. Aminopyridines are also effective in a subset of patients presenting with downbeat nystagmus. As such, all authors agreed that the mainstays of treatment of degenerative cerebellar ataxia are currently physiotherapy, occupational therapy, and speech therapy. For many years, well-controlled rehabilitation studies in patients with cerebellar ataxia were lacking. Data of recently published studies show that coordinative training improves motor function in both adult and juvenile patients with cerebellar degeneration. Given the well-known contribution of the cerebellum to motor learning, possible mechanisms underlying improvement will be outlined. There is consensus that evidence-based guidelines for the physiotherapy of degenerative cerebellar ataxia need to be developed. Future developments in physiotherapeutical interventions will be discussed including application of non-invasive brain stimulation. PMID:24222635

  1. Pathology of articular cartilage and synovial membrane from elbow joints with and without degenerative joint disease in domestic cats.

    Science.gov (United States)

    Freire, M; Meuten, D; Lascelles, D

    2014-09-01

    The elbow joint is one of the feline appendicular joints most commonly and severely affected by degenerative joint disease. The macroscopic and histopathological lesions of the elbow joints of 30 adult cats were evaluated immediately after euthanasia. Macroscopic evidence of degenerative joint disease was found in 22 of 30 cats (39 elbow joints) (73.33% cats; 65% elbow joints), and macroscopic cartilage erosion ranged from mild fibrillation to complete ulceration of the hyaline cartilage with exposure of the subchondral bone. Distribution of the lesions in the cartilage indicated the presence of medial compartment joint disease (most severe lesions located in the medial coronoid process of the ulna and medial humeral epicondyle). Synovitis scores were mild overall and correlated only weakly with macroscopic cartilage damage. Intra-articular osteochondral fragments either free or attached to the synovium were found in 10 joints. Macroscopic or histologic evidence of a fragmented coronoid process was not found even in those cases with intra-articular osteochondral fragments. Lesions observed in these animals are most consistent with synovial osteochondromatosis secondary to degenerative joint disease. The pathogenesis for the medial compartmentalization of these lesions has not been established, but a fragmented medial coronoid process or osteochondritis dissecans does not appear to play a role. © The Author(s) 2014.

  2. Cervical and lumbar MRI in asymptomatic older male lifelong athletes: Frequency of degenerative findings

    Energy Technology Data Exchange (ETDEWEB)

    Healy, J.F.; Healy, B.B.; Wong, W.H.M.; Olson, E.M. [Univ. of California, San Diego, CA (United States)

    1996-01-01

    The athletic activity of the adult U.S. population has increased markedly in the last 20 years. To evaluate the possible long-term effects of such activity on the cervical and lumbar spine, we studied a group of asymptomatic currently very active lifelong male athletes over age 40 (41-69 years old, av. age 53). Nineteen active, lifelong male athletes were studied with MRI and the results compared with previous imaging studies of other populations. An athletic history and a spine history were also taken. Evidence of asymptomatic degenerative spine disease was similar to that seen in published series of other populations. Degenerative changes including disk protrusion and herniation, spondylosis, and spinal stenosis were present and increased in incidence with increasing patient age. In this group, all MRI findings proved to be asymptomatic and did not limit athletic activity. The incidence of lumbar degenerative changes in our study population of older male athletes was similar to those seen in other populations. 14 refs., 8 figs., 1 tab.

  3. 'Lumbar Degenerative Kyphosis' Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception.

    Science.gov (United States)

    Lee, Chang-Hyun; Chung, Chun Kee; Jang, Jee-Soo; Kim, Sung-Min; Chin, Dong-Kyu; Lee, Jung-Kil

    2017-03-01

    Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal deformity. Unlike what its name suggests, LDK does not only include sagittal balance disorder of the lumbar spine and kyphosis, but also sagittal balance disorder of the whole spine and little lordosis of the lumbar spine. Moreover, this disease is closely related to the occupation of female farmers and an outdated Asian life style. These reasons necessitate a change in the nomenclature of this disorder to prevent misunderstanding. We suggest the name "primary degenerative sagittal imbalance" (PDSI), which encompasses degenerative sagittal misalignments of unknown origin in the whole spine in older-age patients, and is associated with back muscle wasting. LDK may be regarded as a subgroup of PDSI related to an occupation in agriculture. Conservative treatments such as exercise and physiotherapy are recommended as first-line treatments for patients with PDSI, and surgical treatment is considered only if conservative treatments failed. The measurement of spinopelvic parameters for sagittal balance is important prior to deformity corrective surgery. LDK can be considered a subtype of PDSI that is more likely to occur in female farmers, and hence the use of LDK as a global term for all degenerative sagittal imbalance disorders is better avoided. To avoid confusion, we recommend PDSI as a newer, more accurate diagnostic term instead of LDK.

  4. Oscillations of disks

    CERN Document Server

    Kato, Shoji

    2016-01-01

    This book presents the current state of research on disk oscillation theory, focusing on relativistic disks and tidally deformed disks. Since the launch of the Rossi X-ray Timing Explorer (RXTE) in 1996, many high-frequency quasiperiodic oscillations (HFQPOs) have been observed in X-ray binaries. Subsequently, similar quasi-periodic oscillations have been found in such relativistic objects as microquasars, ultra-luminous X-ray sources, and galactic nuclei. One of the most promising explanations of their origin is based on oscillations in relativistic disks, and a new field called discoseismology is currently developing. After reviewing observational aspects, the book presents the basic characteristics of disk oscillations, especially focusing on those in relativistic disks. Relativistic disks are essentially different from Newtonian disks in terms of several basic characteristics of their disk oscillations, including the radial distributions of epicyclic frequencies. In order to understand the basic processes...

  5. Magnetic resonance study of lumbar disks in female dancers.

    Science.gov (United States)

    Capel, Antonio; Medina, Fernando Santonja; Medina, Daniel; Gómez, Sebastian

    2009-06-01

    Previous imaging studies have shown that degenerative disk disease is more common in the competitive female gymnast than in asymptomatic nonathletic people of the same age training to any degree. However, results of exposure-discordant monozygotic and classic twin studies suggest that physical loading specific to occupation and sport has a relatively minor role in disk degeneration, beyond that of upright postures and routine activities of daily living. Intensive, regular, and prolonged dancing causes strain on the lumbar spine and can trigger or accelerate the development of degenerative diskopathy. Cross-sectional study; Level of evidence, 3. Forty volunteer female dancers (20 ballet and 20 flamenco) aged between 18 and 31 years (mean = 24.2) underwent magnetic resonance imaging of the lumbar spine. They were compared against a control group of 20 women of the same age. A descriptive analysis was done, and the 2 groups were compared by contingency table analysis using the Pearson chi-square test complemented by an analysis of residuals. Results Nine of the 20 women (45%) in the control group had disk degeneration compared with 13 of the 40 (32.5%) women in the dancer group, with a chi-square of 0.897 (not significant). There were 12 degenerated disks of the 100 explored (12%) in the control group compared with 21 of the 200 explored (10.5%) in the dancer group (chi-square = 0.153; not significant). Dancing cannot be considered a risk factor for lumbar disk degeneration in women. The present study indicates that dancing has no negative effect on the development of degenerative diskopathy.

  6. Contribution of Microglia-Mediated Neuroinflammation to Retinal Degenerative Diseases

    OpenAIRE

    Madeira, Maria H.; Raquel Boia; Santos, Paulo F.; António F. Ambrósio; Santiago, Ana R.

    2015-01-01

    Retinal degenerative diseases are major causes of vision loss and blindness worldwide and are characterized by chronic and progressive neuronal loss. One common feature of retinal degenerative diseases and brain neurodegenerative diseases is chronic neuroinflammation. There is growing evidence that retinal microglia, as in the brain, become activated in the course of retinal degenerative diseases, having a pivotal role in the initiation and propagation of the neurodegenerative process. A bett...

  7. Imaging of degenerative and posttraumatic disease in the shoulder joint with ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Zanetti, Marco E-mail: mzanetti@balgrist.unizh.ch; Hodler, Juerg

    2000-08-01

    This article reviews the examination technique of shoulder ultrasound, normal and abnormal ultrasound findings in acute (posttraumatic) and chronic (degenerative) lesions. Moreover, it reviews the effectiveness of ultrasound in relation to magnetic resonance (MR) imaging. Most authors report that full-thickness tears of the supraspinatus can reliably be diagnosed by ultrasound. However, the simple diagnosis of a full-thickness rotator cuff tear is no longer sufficient for surgical management. The precise localization and size of rotator cuff tears as well as the extent of muscle degeneration is important for surgical planning. For this aspect and for partial-thickness tears of the supraspinatus, for subscapularis lesions as well as for lesions of the long biceps tendons there is no consensus regarding the diagnostic value of ultrasound. To the present, ultrasound (contrary to MR imaging) has failed to demonstrate that it consistently influences the clinician's degree of confidence in the clinical diagnosis or the treatment plan. Therefore, some orthopedic surgeons prefer MR imaging to ultrasound in the evaluation of rotator cuff tears and other abnormalities of the glenohumeral joint. Moreover, MR imaging, especially when combined with arthrography, represents a one-step investigation, which not only allows for assessment of rotator cuff lesion but also of lesions of the labrum (Bankart lesions, SLAP lesions), the joint capsule and the biceps tendon. It also demonstrates muscle atrophy, which represents an important predictor of surgical outcome in rotator cuff repair.

  8. Canine Degenerative Valve Disease: A Case Report

    Directory of Open Access Journals (Sweden)

    Carmenza Janneth Benavides Melo

    2014-07-01

    Full Text Available Degenerative valvular disease or endocardiosis is the most common cardiovascular pathology in dogs. It is characterized by regurgitation of blood into the atria with decreased cardiac output, leading to volume overload with eccentric hypertrophy and congestive heart failure. This report describes the clinical and autopsy findings of a dog, suggestive of valvular endocardiosis. The patient was admitted to the outpatient Veterinary Clinic “Carlos Martínez Hoyos” at the University of Nariño (Pasto, Colombia. His owner said the dog was sick for two months, with signs of respiratory disease, weight loss, and decay. Clinical examination showed very pale mucous membranes, inspiratory dyspnea, rale, split S2, grade 4 mid-systolic murmur of regurgitation, and abdominal dilatation with sign of positive shock wave. Necropsy evidenced plenty of translucent watery material in the abdominal, chest and pericardium cavity, severely enlarged and rounded heart with thickened atrioventricular valves, moderate reduction in liver size and signs of lobulation, severely diminished and pale kidneys with irregular surface showing the presence of multiple cystic areas in corticomedullary region. Samples were taken from these tissues and fixed in 10% buffered formalin to be processed for histopathological analysis at the Laboratory of Pathology at the University of Nariño, using hematoxylin and eosin stain. This way, degenerative valvular disease was diagnosed.

  9. Degenerative Achilles tendon disease; Assessment by magnetic resonance and ultrasonography

    Energy Technology Data Exchange (ETDEWEB)

    Neuhold, A.; Stiskal, M. (Rudolfinerhaus, Vienna (Austria). Department of Diagnostic Imaging); Kainberger, F.; Schwaighofer, B. (Vienna Univ. (Austria). 2. Medizinische Klinik)

    As Magnetic Resonance (MR) imaging and Ultrasound (US) allow the evaluation of soft-tissue structures not previously possible with other imaging techniques, a clinical study has been undertaken to determine the value of these 2 modalities in the detection of lesions in the Achilles tendon (AT), other than acute total rupture. Seven healthy subjects and 28 symptomatic patients with Achillodynia and/or signs of thickening of the AT were investigated with MR and US; all results were compared with the clinical features. Surgical findings were available in 14 patients. Patients were divided into 3 groups; those with tendon thickening, incomplete and complete ruptures. Thickening of the AT was easily detected with both methods. MR was superior in the detection of incomplete tendon rupture and in the evaluation of various stages of chronic degenerative changes. It is concluded that only if US remains unclear, an additional MR study should be performed and together with the clinical diagnosis indication for surgery can be made more efficient. (author). 24 refs.; 4 figs.

  10. Disk Storage Server

    CERN Multimedia

    This model was a disk storage server used in the Data Centre up until 2012. Each tray contains a hard disk drive (see the 5TB hard disk drive on the main disk display section - this actually fits into one of the trays). There are 16 trays in all per server. There are hundreds of these servers mounted on racks in the Data Centre, as can be seen.

  11. Galactic Disk Warps

    NARCIS (Netherlands)

    Kuijken, K.; García, I.

    2000-01-01

    Abstract: This review addresses recent developments in the field of disk galaxy warps. Both results from a new HI survey of edgeon disk galaxies, and of simulations of the interaction between a disk+halo and an orbiting satelite, will be discussed.

  12. Galactic Disk Warps

    CERN Document Server

    Kuijken, K; Kuijken, Konrad; Garcia, Inigo

    2000-01-01

    This review addresses recent developments in the field of disk galaxy warps. Both results from a new HI survey of edgeon disk galaxies, and of simulations of the interaction between a disk+halo and an orbiting satelite, will be discussed.

  13. Chemistry in Protoplanetary Disks

    CERN Document Server

    Henning, Thomas

    2013-01-01

    This comprehensive review summarizes our current understanding of the evolution of gas, solids and molecular ices in protoplanetary disks. Key findings related to disk physics and chemistry, both observationally and theoretically, are highlighted. We discuss which molecular probes are used to derive gas temperature, density, ionization state, kinematics, deuterium fractionation, and study organic matter in protoplanetary disks.

  14. Optical Disk Technology.

    Science.gov (United States)

    Abbott, George L.; And Others

    1987-01-01

    This special feature focuses on recent developments in optical disk technology. Nine articles discuss current trends, large scale image processing, data structures for optical disks, the use of computer simulators to create optical disks, videodisk use in training, interactive audio video systems, impacts on federal information policy, and…

  15. Degenerative disease of the lumbar spine.

    Science.gov (United States)

    Kovacs, F M; Arana, E

    2016-04-01

    In the last 25 years, scientific research has brought about drastic changes in the concept of low back pain and its management. Most imaging findings, including degenerative changes, reflect anatomic peculiarities or the normal aging process and turn out to be clinically irrelevant; imaging tests have proven useful only when systemic disease is suspected or when surgery is indicated for persistent spinal cord or nerve root compression. The radiologic report should indicate the key points of nerve compression, bypassing inconsequential findings. Many treatments have proven inefficacious, and some have proven counterproductive, but they continue to be prescribed because patients want them and there are financial incentives for doing them. Following the guidelines that have proven effective for clinical management improves clinical outcomes, reduces iatrogenic complications, and decreases unjustified and wasteful healthcare expenditures.

  16. Influence of degenerative changes of intervertebral disc

    Directory of Open Access Journals (Sweden)

    WANG Yi

    2012-04-01

    Full Text Available 【Abstract】Objective: To investigate the material properties of normal and degenerated intervertebral discs (IVDs and examine the effect of degenerative changes on IVD pathology. Methods: A computer-based online search was under-taken to identify English articles about material properties of IVDs published from January 1950 to 2011 in PubMed database. The retrieved keywords included material properties, intervertebral disc and degeneration. Based on the principles of reliability, advancement and efficiency, the obtained data were primarily examined, and the original source was retrieved to read the full-text. Repetitive articles were excluded. The data of material properties of normal and degenerated IVDs were summarized and analyzed by meta-analysis. Results: The data of Young's modulus, Poisson's ratio, shear modulus, hydraulic permeability and intradiscal pres-sure of normal and degenerated IVDs were obtained. Com-pared with normal IVDs, the Young's modulus and shear modulus of annulus fibrosus and nucleus pulposus were higher in degenerated IVDs, the Poisson's ratio was lower while the hydraulic permeability and intradiscal pressure were higher. Besides, the degeneration-related alterations in IVDs had an influence both on itself and other spinal structures, leading to diseases such as bulging disc, discogenic pain and spinal stenosis. Meanwhile, the heavy mechanical loading and injury indicated important pathways to IVD degeneration. Conclusions: To a certain extent, the degenerative changes of IVD influence its material properties. And the degeneration-related alterations of composition can cause structural failure of IVDs, leading to injuries and diseases. Key words: Intervertebral disc; Mechanical phenomena; Degeneration; Elastic modulus; Permeability; Pathology

  17. Lumbar degenerative kyphosis: radiologic analysis and classifications.

    Science.gov (United States)

    Jang, Jee-Soo; Lee, Sang-Ho; Min, Jun-Hong; Han, Kyoung-Mi

    2007-11-15

    Retrospective study of a consecutive patient series. To review the radiographic classification of patients with sagittal imbalance due to lumbar degenerative kyphosis (LDK) and to determine correlation between thoracic and lumbar curve. Lumbar degenerative kyphosis is one of the common spinal deformities in Asian countries, especially Korea and Japan. However, there have been few studies regarding the classification and treatment of this disease. Seventy-eight patients with LDK were analyzed and classified according to the standing lateral whole spine findings. Total lumbar lordosis (L1-S1), thoracic kyphosis (T5-T12), sacral slope, thoracolumbar angle (T11-L1), and sagittal vertical axis (SVA) were measured on the lateral view of the whole spine. Spinal curve deformities were classified into 2 groups according to the thoracolumbar (T-L) junction angle: flat or lordotic angle (Group 1; N = 53) and kyphotic angle (Group 2; N = 25). In Group 1, significant correlations between the thoracic and lumbar curves (r = 0.772, P sagittal thoracic compensated group. In contrast, In Group 2, no correlation was found between the thoracic and lumbar curves in the decompensated group (r = 0.179, P = 0.391), but we found a significant correlation between lordosis and sacral slope (r = 0.442, P = 0.027). By this result, Group 2 was classified as sagittal thoracic decompensated group. There was significant difference in SVA between 2 groups (P = 0.020). The angle of the thoracolumbar junction is an important parameter in determining whether a sagittal thoracic compensatory mechanism exists in LDK. We assumed that existence of a compensatory mechanism in the proximal spine is central to the determination of the fusion levels in the treatment of LDK.

  18. OPERATIVE TREATMENT FOR DEGENERATIVE LUMBAR SPINAL STENOSIS

    Directory of Open Access Journals (Sweden)

    Samo K. Fokter

    2002-11-01

    Full Text Available Background. Degenerative lumbar spinal stenosis (DLSS is a common cause of low back and leg pain in the elderly. Conservative treatment seldom results in sustained improvement.Methods. Fifty-six patients (33 women, 23 men older than 50 years (mean 67 years, range 51 to 82 years and with no prior low back surgery were treated from 1993 to 1999 for clinical and radiologic evidence of DLSS. The goal of this study was to describe the results of decompressive laminectomy with or without fusion in terms of reoperation, severity of back pain, leg pain and patient satisfaction. Answers to Swiss spinal stenosis questionnaires completed before surgery and one to five years afterwards were evaluated. Seven patients (12.5% with degenerative spondylolisthesis, scoliosis and/or more radical facetectomies received fusion.Results. Of the 56 patients in the original cohort, two were deceased and two had undergone reoperation by follow-up. Forty-eight patients answered questionnaires. Average duration of follow-up was 2.5 years. More than 70 percent of the respondents had no or only mild back or buttock pain at follow-up and more than 60 percent were able to walk more than 500 m. Added fusion reduced the incidence of low back pain and pain frequency, and increased walking distance (ANOVA.Conclusions. Eighty-one percent of patients were satisfied with the results of surgery and 87.5% would choose to have the operation again if they had the choice. Decompressive laminectomy for DLSS yields best results if instrumented fusion is included in the procedure.

  19. Magnetic resonance imaging of intervertebral disk disease: clinical and pulse sequence considerations

    Energy Technology Data Exchange (ETDEWEB)

    Modic, M.T.; Pavlicek, W.; Weinstein, M.A.; Boumphrey, F.; Ngo, F.; Hardy, R.; Duchesneau, P.M.

    1984-07-01

    Sixty-five patients were examined with magnetic resonance imaging (MR) to determine what combination of operator-selectable controls would result in a thorough examination of the intervertebral disks. There were 20 normal subjects, 8 with degenerative lumbar disk disease, 27 with both degeneration and herniation, 5 with stenosis of the spinal canal, and 5 with disk space infection. Comparison with radiographs, high-resolution CT scans, and myelograms showed that MR was the most sensitive for identification of degeneration and disk space infection, separating the normal nucleus pulposus from the annulus and degenerated disk. Herniation, stenosis of the canal, and scarring can be identified as accurately with MR as with CT or myeolography.

  20. REMARKS ON JOHN DISKS

    Institute of Scientific and Technical Information of China (English)

    Chu Yuming; Cheng Jinfa; Wang Gendi

    2009-01-01

    Let D R2 be a Jordan domain, D* = -R2 \\ -D, the exterior of D. In this article, the authors obtained the following results: (1) If D is a John disk, then D is an outer linearly locally connected domain; (2) If D* is a John disk, then D is an inner linearly locally connected domain; (3) A homeomorphism f: R2→R2 is a quasiconformal mapping if and only if f(D) is a John disk for any John disk D(∈)R2; and (4) If D is a bounded quasidisk, then D is a John disk, and there exists an unbounded quasidisk which is not a John disk.

  1. Exploring Disks Around Planets

    Science.gov (United States)

    Kohler, Susanna

    2017-07-01

    Giant planets are thought to form in circumstellar disks surrounding young stars, but material may also accrete into a smaller disk around the planet. Weve never detected one of these circumplanetary disks before but thanks to new simulations, we now have a better idea of what to look for.Image from previous work simulating a Jupiter-mass planet forming inside a circumstellar disk. The planet has its own circumplanetary disk of accreted material. [Frdric Masset]Elusive DisksIn the formation of giant planets, we think the final phase consists of accretion onto the planet from a disk that surrounds it. This circumplanetary disk is important to understand, since it both regulates the late gas accretion and forms the birthplace of future satellites of the planet.Weve yet to detect a circumplanetary disk thus far, because the resolution needed to spot one has been out of reach. Now, however, were entering an era where the disk and its kinematics may be observable with high-powered telescopes (like the Atacama Large Millimeter Array).To prepare for such observations, we need models that predict the basic characteristics of these disks like the mass, temperature, and kinematic properties. Now a researcher at the ETH Zrich Institute for Astronomy in Switzerland, Judit Szulgyi, has worked toward this goal.Simulating CoolingSzulgyi performs a series of 3D global radiative hydrodynamic simulations of 1, 3, 5, and 10 Jupiter-mass (MJ) giant planets and their surrounding circumplanetary disks, embedded within the larger circumstellar disk around the central star.Density (left column), temperature (center), and normalized angular momentum (right) for a 1 MJ planet over temperatures cooling from 10,000 K (top) to 1,000 K (bottom). At high temperatures, a spherical circumplanetary envelope surrounds the planet, but as the planet cools, the envelope transitions around 64,000 K to a flattened disk. [Szulgyi 2017]This work explores the effects of different planet temperatures and

  2. Gas-filled parasymphyseal pubic cyst associated with degenerative joint disease

    Energy Technology Data Exchange (ETDEWEB)

    Martel, J.P.; Spouge, A.R. [London Health Science Centre, Diagnostic Imaging University Hospital, London, ON (Canada)

    2007-06-15

    Parasymphyseal cysts are a rare and poorly understood entity. This case report describes a gas-containing parasymphyseal cystic lesion associated with degenerative change and vacuum phenomenon in the pubic symphysis. The mass was discovered incidentally in a 72-year-old asymptomatic male who underwent a transrectal ultrasound-guided biopsy of the prostate and the nature of the lesion was confirmed on magnetic resonance imaging (MRI) and computed tomography (CT). We hypothesize that the gas within the parasymphyseal cystic mass arose from a vacuum phenomenon in the pubic symphysis, with subsequent extrusion of gas from the joint into the cyst itself. It is important for radiologists to be aware of the existence of this entity to avoid unnecessary surgery for patients. (orig.)

  3. Multisegmental pneumatocysts of the lumbar spine mimic osteolytic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Steingruber, I.E.; Buchberger, W. [Dept. of Radiology, University of Innsbruck (Austria); Bach, C.M.; Wimmer, C.; Nogler, M. [Dept. of Orthopedic Surgery, University of Innsbruck (Austria)

    2001-05-01

    Circumscribed radiolucencies within the vertebral bones can be due to a variety of changes including benign and malignant tumours or tumour-like lesions. Radiolucencies due to degenerative intraosseous pneumatocyst are very uncommon but have to be taken into the differential diagnosis in well-circumscribed lytic lesions of the vertebral bodies. We describe the first case of multisegmental pneumatocysts in the lumbar spine mimicking osteolytic lesions. On computed tomography, the air-equivalent attenuation values of the lesions and the close vicinity to the degenerated vertebral endplates with vacuum phenomenon led to the correct diagnosis. (orig.)

  4. Isolated unilateral disk edema

    OpenAIRE

    Varner P

    2011-01-01

    Paul VarnerJohn J Pershing VAMC, Poplar Bluff, MO, USAAbstract: Isolated unilateral disk edema is a familiar clinical presentation with myriad associations. Related, non-consensus terminology is a barrier to understanding a common pathogenesis. Mechanisms for the development of disk edema are reviewed, and a new framework for clinical differentiation of medical associations is presented.Keywords: disk edema, axoplasmic flow, clinical multiplier, optic neuritis, ischemic optic neuropathy, papi...

  5. Isolated unilateral disk edema

    Directory of Open Access Journals (Sweden)

    Varner P

    2011-07-01

    Full Text Available Paul VarnerJohn J Pershing VAMC, Poplar Bluff, MO, USAAbstract: Isolated unilateral disk edema is a familiar clinical presentation with myriad associations. Related, non-consensus terminology is a barrier to understanding a common pathogenesis. Mechanisms for the development of disk edema are reviewed, and a new framework for clinical differentiation of medical associations is presented.Keywords: disk edema, axoplasmic flow, clinical multiplier, optic neuritis, ischemic optic neuropathy, papilledema

  6. [Features of the clinical course of intravertebral disk herniation in degenerative lumbar stenosis].

    Science.gov (United States)

    Kariev, M Kh; Norov, A U; Ishmukhamedov, S N; Iugaĭ, I A

    2001-01-01

    The paper presents a clinical and neurological analysis of 110 patients with discal hernias who were divided into 2 groups: 1) 50 patients with normal sizes of the vertebral column; 2) 51 patients with its stenosis. Compression syndromes were major in all cases. In patients in whom discal hernia was concurrent with lumbar stenosis, the clinical course was characterized by dull or aching pains in the low back and legs, by symptoms of dysbasia neurasthenica intermittens, severe motor and sensory disorders with autonomic impositions.

  7. SENILE DEGENERATIVE CHANGES IN ADULT LUMBAR SPINE! - A PROSPECTIVE STUDY

    Directory of Open Access Journals (Sweden)

    Garjesh Singh

    2015-11-01

    Full Text Available : BACKGROUND: Low back pain (LBP is a common presenting complaint affecting mostly middle aged and older person and traditionally considered as ageing process, but now-a-days large number of younger people are also affected by this debilitating chronic disorder. The cause of early onset of degenerative spine disease is multifactorial, but genetical predisposition plays very important role. AIMS AND OBJECTIVE: To find out association between genetic predisposition and degenerative spine disease in adult patients and to assess the pattern of MRI findings of various degenerative diseases in lumbo-sacral spine. MATERIAL AND METHOD: The present cross-sectional study had been performed among 100 selected patients in 1yr period, who presented with chief complaint of chronic low back pain. After taking detailed clinical and professional history, MRI of lumbosacral spine had been performed. Total 100 patients were divided in two groups on the basis of genetical predisposition. Prevalence and spectrum of degenerative changes were compared between both groups. RESULTS: Hundred patients of 20 to 35-year age had been selected with mean age of 27yr. Out of 100 patients; 47 were male and 53 were female. The most common degenerative findings were desiccation of disc (95% followed by disc bulge, herniation, spinal canal stenosis, ligamentum flavum hypertrophy, facet joint hypertrophy and modic changes. L4-L5 and L5- S1 were the most commonly involved spinal levels for any degenerative pathology. CONCLUSION: Good association is seen between early onset of degenerative spine disease and genetical predisposition in patients who have history of similar type degenerative spine disease in one or more first degree relatives in comparison to those patients who do not have any genetical predisposition. So it can be concluded that heredity play important role in early onset of degenerative spine disease in adults.

  8. A valve disk

    Energy Technology Data Exchange (ETDEWEB)

    Khayrullin, N.A.; Isayev, B.N.; Kruglov, S.A.; Molokanov, Yu.K.; Shchelkunov, V.A.; Shegay, V.R.; Vizhgorodskiy, B.N.

    1982-01-01

    A valve disk is proposed which includes a horizontal bed, on which there are laminar valves arranged in staggered order. To ensure the stable and effective operation of the disk in a broad range of loads by compensating for the direct flow and the partial sectioning of the disk bed, it is equipped with compensating elements installed in openings in the bed and hinged with it. They are made in the form of straight, triangular prisms with ports in the bases. The prisms are installed with the capability of movement relative to the disk bed. The valves are positioned on the upper lateral facets of the compensating elements.

  9. Chronic degenerative diseases in elderly: physiotherapeutic data

    Directory of Open Access Journals (Sweden)

    Lais Keylla Felipe

    2011-09-01

    Full Text Available Objective: To assess the most frequent chronic diseases in the elderly population of a private clinic of Physiotherapy. Methods: We assessed medical records of clients who received treatment at a Physiotherapy clinic in the period 2005 to 2008, looking for chronic diseases as diagnosis and/or related to them. Of these, we selected those which contained birth date and/or aged sixty-five years or above. An instrument like a check list, developed by the researchers, identified: quantity, gender, medical diagnosis and comorbidities. For quantification of variables we applied simple percentage calculation. Results: In the study period, there were four hundred fifty-eight records, of which forty-nine corresponded to the survey’s inclusion criteria. The majority 59.2% (n=29 referred to the year 2008; 26.6% (n=13 being males and 73.4% (n=36 females. The most commonly found diagnosis comprised osteoarthritis 57.1% (n=28, fracture and/or history of fractures 24.4% (n=12 and other diagnosis 48.9% (n=24. Associated chronic diseases included diabetes mellitus 18.3% (n=9 and systemic hypertension 57.1% (n=23. Conclusion: Chronic degenerative diseases in elderly have received increasing attention from health professionals; osteoarthritis being the most common diagnosis in this study, followed by fracture and/or history of fractures. The comorbidities represented a greater negative impact in the quality of life of elderly.

  10. Lesiones laborales

    OpenAIRE

    2015-01-01

    Las lesiones laborales se producen por un esfuerzo repetitivo, cuando un exceso de presión se ejerce sobre una parte del cuerpo provocando lesiones óseas, articulares, musculares y daños en los tejidos. Los accidentes laborales también pueden producir una lesión en el organismo y esto sumado a diversos factores es un problema para la reinserción laboral de los trabajadores de la energía eléctrica. Objetivo: Establecer cuáles son las lesiones más frecuentes que afectan a los ...

  11. Degenerative Changes in the Spine: Is This Arthritis?

    Science.gov (United States)

    ... in my spine. Does this mean I have arthritis? Answers from April Chang-Miller, M.D. Yes. ... spine. Osteoarthritis is the most common form of arthritis. Doctors may also refer to it as degenerative ...

  12. Vacuum facet phenomenon: a computed tomographic sign of degenerative spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lefkowitz, D.M.; Quencer, D.M.

    1982-08-01

    A vacuum facet phenomenon, seen on computed tomography as a lens-shaped lucency within a lumbar facet joint, was observed as a consequence of degenerative spondylolisthesis. The significance of this finding is discussed.

  13. Peritalar destabilisation syndrome (adult flatfoot with degenerative glenopathy).

    Science.gov (United States)

    Pisani, Giacomo

    2010-12-01

    In cases of adult acquired flatfoot associated with peritalar destabilisation, special reference is made to the plantar calcaneo-navicular (spring) ligament's degenerative disease (degenerative glenopathy) and to the presence of the accessory navicular bone as a possible pathogenic cause. Peritalar destabilization syndrome is proposed for the articular (subtalar and talo-navicular joints) or tendinosis (tibialis posterior tendon) separately or in association with degenerative glenopathy of the coxa pedis. In degenerative glenopathy surgical reconstruction of the glenoid also makes use of a posterior tibial split to create a new tibial-navicular ligament. The concept of pronatory syndrome deemed as the root the pathological subtalar pronation, which is an entirely secondary factor in peritalar destabilisation, must be questioned. We must keep in mind that subtalar pronation and supination are respectively subsequent to opening and closing of the coxa pedis (talo-calcaneo-navicular joint) kinetic chain.

  14. Functional outcome of surgical management of degenerative lumbar canal stenosis

    Directory of Open Access Journals (Sweden)

    Rajendra Nath

    2012-01-01

    Conclusion: Operative treatment in patients of degenerative lumbar canal stenosis yields excellent results as observed on the basis of JOA scoring system. No patient got recurrence of symptoms of nerve compression.

  15. Contribution of Microglia-Mediated Neuroinflammation to Retinal Degenerative Diseases

    Directory of Open Access Journals (Sweden)

    Maria H. Madeira

    2015-01-01

    Full Text Available Retinal degenerative diseases are major causes of vision loss and blindness worldwide and are characterized by chronic and progressive neuronal loss. One common feature of retinal degenerative diseases and brain neurodegenerative diseases is chronic neuroinflammation. There is growing evidence that retinal microglia, as in the brain, become activated in the course of retinal degenerative diseases, having a pivotal role in the initiation and propagation of the neurodegenerative process. A better understanding of the events elicited and mediated by retinal microglia will contribute to the clarification of disease etiology and might open new avenues for potential therapeutic interventions. This review aims at giving an overview of the roles of microglia-mediated neuroinflammation in major retinal degenerative diseases like glaucoma, age-related macular degeneration, and diabetic retinopathy.

  16. Planetesimals in Debris Disks

    CERN Document Server

    Youdin, Andrew N

    2015-01-01

    Planetesimals form in gas-rich protoplanetary disks around young stars. However, protoplanetary disks fade in about 10 Myr. The planetesimals (and also many of the planets) left behind are too dim to study directly. Fortunately, collisions between planetesimals produce dusty debris disks. These debris disks trace the processes of terrestrial planet formation for 100 Myr and of exoplanetary system evolution out to 10 Gyr. This chapter begins with a summary of planetesimal formation as a prelude to the epoch of planetesimal destruction. Our review of debris disks covers the key issues, including dust production and dynamics, needed to understand the observations. Our discussion of extrasolar debris keeps an eye on similarities to and differences from Solar System dust.

  17. Development of modulators against degenerative aging using radiation fusion technology

    Energy Technology Data Exchange (ETDEWEB)

    Jo, S. K.; Park, H. R.; Jang, B. S.; Roh, C. H.; Eom, H. S.; Choi, N. H.; Seol, M. A.; Kim, S. H.; Choi, H. M.; Park, M. K.; Shin, H. J.; Ryu, D. K.; Oh, W. J.; Kim, S. H; Yee, S. T.

    2012-04-15

    1. Objectives Establishment of modelling of degenerative aging using radiation technology Development of aging modulators using radiation degenerative aging model 2. Project results Establishment of the modeling of degenerative aging using radiation technology - The systematic study on the comparison of radiation-induced degeneration and natural aging process in animals and cells confirmed the biological similarity between these two degeneration models - The effective biomarkers were selected for the modelling of degenerative aging using radiation (10 biomarkers for immune/hematopoiesis, 1 for oxidative stress, 6 for molecular signaling, 3 for lipid metabolism) - The optimal irradiation condition was established for the modelling of degerative aging (total 5Gy with fractionation by over 10 times, lapse of over 4 months) - The molecular mechanisms of radiation-induced degeneration were studied including chronic inflammation (lung), inflammation-related lipid metabolism disturbance, mitochondria biogenesis and dynamics - The radiation degenerative model was evaluated with previously known natural substances (resveratrol, EGCG, etc) Development of aging modulators using radiation degenerative aging model - After the screening of about 800 natural herb extracts, 5 effective substances were selected for aging modulation. - 3 candidate compositions were selected from 20 compositions made from effective substances by in vitro evaluation (WAH2, WAH6, WAH7) - 1 composition (WAH6) was selected as the best aging modulator by in vivo evaluation in radiation-induced aging models and degenerative disease models. 3. Expected benefits and plan of application The modelling of degenerative aging using radiation can facilitate the aging research by providing the useful cell/animal models for aging research A large economic benefits are expected by the commercialization of developed aging modulators (over 10 billion KW in 2015.

  18. Skipping Posterior Dynamic Transpedicular Stabilization for Distant Segment Degenerative Disease

    Directory of Open Access Journals (Sweden)

    Bilgehan Solmaz

    2012-01-01

    Full Text Available Objective. To date, there is still no consensus on the treatment of spinal degenerative disease. Current surgical techniques to manage painful spinal disorders are imperfect. In this paper, we aimed to evaluate the prospective results of posterior transpedicular dynamic stabilization, a novel surgical approach that skips the segments that do not produce pain. This technique has been proven biomechanically and radiologically in spinal degenerative diseases. Methods. A prospective study of 18 patients averaging 54.94 years of age with distant spinal segment degenerative disease. Indications consisted of degenerative disc disease (57%, herniated nucleus pulposus (50%, spinal stenosis (14.28%, degenerative spondylolisthesis (14.28%, and foraminal stenosis (7.1%. The Oswestry Low-Back Pain Disability Questionnaire and visual analog scale (VAS for pain were recorded preoperatively and at the third and twelfth postoperative months. Results. Both the Oswestry and VAS scores showed significant improvement postoperatively (P<0.05. We observed complications in one patient who had spinal epidural hematoma. Conclusion. We recommend skipping posterior transpedicular dynamic stabilization for surgical treatment of distant segment spinal degenerative disease.

  19. Etiology, pathophysiology and conservative management of degenerative joint disease

    Directory of Open Access Journals (Sweden)

    Jandrić Slavica

    2002-01-01

    Full Text Available Etiology of degenerative joint diseases Etiology of degenerative joint diseases is still not clearly understood and there is no specific management for this group of diseases. Various pathological conditions cause damage of the articular cartilage and lead to clinically and radiographically recognized impairment. Biomechanical, metabolic, genetic factors inflammation and other risk factors contribute to development of osteoarthrosis. Pathophysiology of degenerative joint diseases Osteoarthrosis is characterized by progressive erosion of articular cartilage and bone overgrowth at the joint margins. Cartilage integrity requires balance between synthesis and degradation of matrix components. Chondrocytes react to various mechanical and chemical stresses in order to stabilize and restore the tissue. Failures in stabilizing and restoring the tissue lead to cartilage degeneration that may be irreversibile. For better understanding of conservative management of degenerative joint diseases it is important to know the impact of pathophysiology mechanisms on development of degenerative joint diseases. There is great variability in the rate of progression of erosive processes in articular cartilage in clinical radiographic signs and course of the disease. This is in relation with many factors, as well as with management and response to therapy. Treatment of degenerative joint diseases Treatment should vary depending on the severity of disease and patient's expectations and level of activity. Besides analgesic and anti-inflammatory drugs, conventional and not conventional treatment and techniques can be used for management of osteoarthrosis. Physical therapy and exercises are very important for maintaining muscle strength, joint stability and mobility, but should be closely monitored for optimal efficacy.

  20. Association between lumbar Modic changes and MRI finding of degenerative disc in patients with low back pain

    Directory of Open Access Journals (Sweden)

    Seyed Reza Saadat Mostafavi

    2016-01-01

    Full Text Available Background: Recent studies have indicated the relation of vertebral endplate lesions (Modic changes to low back pain (LBP. The aim of this study was to investigate the Modic changes in magnetic resonance imaging (MRI of patients with low back pain, and its correlation with age, sex, type of changes, number of involved segments and location of changes. Additionally, association of degenerative disc changes and disc herniation was assessed. Methods: In this retrospective study, MRI records of 229 patients with LBP referring to Medical Center of Hazrat-e-Rasoul Hospital, Tehran, Iran, from August to February 2014, were assessed and Modic changes and degenerative and herniated disc changes were recorded. Results: Based on our observations, a significant association between Modic type and age (P= 0.003 existed in patients with LBP. The highest prevalence in Modic location were observed in anterior part of vertebral endplate (48.8%, P= 0.001. Although, observation of the Modic changes in superior vertebral endplate was higher than inferior parts, but this differences was not statistically significant. The highest prevalence in degenerative disc disease was disc dehydration which was observed in 18.1% of patients (P= 0.04. The relationship between the degenerative changes and Modic type was significant (P= 0.04, while the most prevalent change of disc contour was disc bulging which occurred in 23.7% of patients (P= 0.01. The highest frequency of abnormal disc contour were observed in Modic type 2 which was statistically significant (P= 0.01. Modic surface involvement above 25% was significantly associated with disc herniation (P= 0.04. There was no significant association between Modic height involvement above 25% and disc herniation. Conclusion: Considering significant association between Modic changes and degenerative and herniated disc changes, reporting of Modic changes is necessary.

  1. On the Relative Relevance of Subject-Specific Geometries and Degeneration-Specific Mechanical Properties for the Study of Cell Death in Human Intervertebral Disk Models

    Science.gov (United States)

    Malandrino, Andrea; Pozo, José M.; Castro-Mateos, Isaac; Frangi, Alejandro F.; van Rijsbergen, Marc M.; Ito, Keita; Wilke, Hans-Joachim; Dao, Tien Tuan; Ho Ba Tho, Marie-Christine; Noailly, Jérôme

    2015-01-01

    Capturing patient- or condition-specific intervertebral disk (IVD) properties in finite element models is outmost important in order to explore how biomechanical and biophysical processes may interact in spine diseases. However, disk degenerative changes are often modeled through equations similar to those employed for healthy organs, which might not be valid. As for the simulated effects of degenerative changes, they likely depend on specific disk geometries. Accordingly, we explored the ability of continuum tissue models to simulate disk degenerative changes. We further used the results in order to assess the interplay between these simulated changes and particular IVD morphologies, in relation to disk cell nutrition, a potentially important factor in disk tissue regulation. A protocol to derive patient-specific computational models from clinical images was applied to different spine specimens. In vitro, IVD creep tests were used to optimize poro-hyperelastic input material parameters in these models, in function of the IVD degeneration grade. The use of condition-specific tissue model parameters in the specimen-specific geometrical models was validated against independent kinematic measurements in vitro. Then, models were coupled to a transport-cell viability model in order to assess the respective effects of tissue degeneration and disk geometry on cell viability. While classic disk poro-mechanical models failed in representing known degenerative changes, additional simulation of tissue damage allowed model validation and gave degeneration-dependent material properties related to osmotic pressure and water loss, and to increased fibrosis. Surprisingly, nutrition-induced cell death was independent of the grade-dependent material properties, but was favored by increased diffusion distances in large IVDs. Our results suggest that in situ geometrical screening of IVD morphology might help to anticipate particular mechanisms of disk degeneration. PMID:25717471

  2. On the relative relevance of subject-specific geometries and degeneration-specific mechanical properties for the study of cell death in human intervertebral disk models.

    Science.gov (United States)

    Malandrino, Andrea; Pozo, José M; Castro-Mateos, Isaac; Frangi, Alejandro F; van Rijsbergen, Marc M; Ito, Keita; Wilke, Hans-Joachim; Dao, Tien Tuan; Ho Ba Tho, Marie-Christine; Noailly, Jérôme

    2015-01-01

    Capturing patient- or condition-specific intervertebral disk (IVD) properties in finite element models is outmost important in order to explore how biomechanical and biophysical processes may interact in spine diseases. However, disk degenerative changes are often modeled through equations similar to those employed for healthy organs, which might not be valid. As for the simulated effects of degenerative changes, they likely depend on specific disk geometries. Accordingly, we explored the ability of continuum tissue models to simulate disk degenerative changes. We further used the results in order to assess the interplay between these simulated changes and particular IVD morphologies, in relation to disk cell nutrition, a potentially important factor in disk tissue regulation. A protocol to derive patient-specific computational models from clinical images was applied to different spine specimens. In vitro, IVD creep tests were used to optimize poro-hyperelastic input material parameters in these models, in function of the IVD degeneration grade. The use of condition-specific tissue model parameters in the specimen-specific geometrical models was validated against independent kinematic measurements in vitro. Then, models were coupled to a transport-cell viability model in order to assess the respective effects of tissue degeneration and disk geometry on cell viability. While classic disk poro-mechanical models failed in representing known degenerative changes, additional simulation of tissue damage allowed model validation and gave degeneration-dependent material properties related to osmotic pressure and water loss, and to increased fibrosis. Surprisingly, nutrition-induced cell death was independent of the grade-dependent material properties, but was favored by increased diffusion distances in large IVDs. Our results suggest that in situ geometrical screening of IVD morphology might help to anticipate particular mechanisms of disk degeneration.

  3. Accelerated Degenerative Joint Disease After Staged Hip Arthroscopy and Periacetabular Osteotomy in a Patient with Hip Dysplasia.

    Science.gov (United States)

    Guss, Michael; Youm, Thomas

    2017-05-01

    Hip dysplasia, when significant, is effectively treated with periacetabular osteotomy. There have been good results reported with hip arthroscopy when dysplasia is mild. However, when dysplasia is significant, hip arthroscopy with labral repair alone has led to poor results and even rapid decline to end stage arthritis. Staged hip arthroscopy and periacetabular osteotomy would potentially treat the labral lesion and correct the underlying bony abnormality that resulted in the labral pathology. Such a staged treatment plan should help prevent progression to degenerative joint disease. We report a case of a 33-year-old woman who presented with left hip pain and was diagnosed with mild hip dysplasia and a labral tear. She underwent staged hip arthroscopy and labral repair followed by periacetabular osteotomy 2 weeks later. Three and a half months after surgery she developed constant pain and began limping at 5 months. Radiographs showed progression to severe degenerative joint disease. The patient was indicated for total hip arthroplasty.

  4. Radiation treatment of painful degenerative skeletal conditions; Schmerzbestrahlung bei degenerativ bedingten Skeletterkrankungen

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, U. [Muenster Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie - Radioonkologie; Micke, O. [Muenster Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie - Radioonkologie; Willich, N. [Muenster Univ. (Germany). Klinik und Poliklinik fuer Strahlentherapie - Radioonkologie

    1996-10-01

    The study reported was intended to present own experience with irradiation for treatment of painful degenerative skeletal conditions and examine the long-term effects of this treatment. A retrospective study was performed covering the period from 1985 until 1991, examining 157 patients suffering from painful degenerative skeletal conditions who entered information on the success of their radiation treatment in a questionnaire. 94 of the questionnaires could be used for evaluation. Pain anamnesis revealed periods of more than one year in 45% of the cases. 74% of the patients had been treated without success with drug or orthopedic therapy. Immediately after termination of the radiotherapy, 38% of the patients said to be free of pain or to feel essentially relieved, while at the time the questionnaire was distributed, the percentage was 76%. Thus in our patient material, radiotherapy for treatment of painful degenerative skeletal lesions was successful in 76% of the cases and for long post-treatment periods, including those cases whith long pain anamnesis and unsuccessful conventional pre-treatment. (orig./MG) [Deutsch] Ziel dieser Untersuchung war es, die eigenen Erfahrungen mit der Schmerzbestrahlung degenerativer Skeletterkrankungen darzustellen und vor allem die Langzeitergebnisse zu untersuchen. Im Zeitraum von 1985 bis 1991 wurden 157 Patienten mit schmerzhaften degenerativen Gelenkerkrankungen retrospektiv untersucht. Der Therapieerfolg wurde mittels Fragebogenaktion ermittelt. Insgesamt waren 94 Frageboegen auswertbar. Die Schmerzanamnese betrug in 45% der Faelle ueber 1 Jahr. Bei 74% der Patienten war eine erfolglose medikamentoese oder orthopaedische Vorbehandlung erfolgt. Sofort nach Beendigung der Radiotherapie gaben insgesamt 38% der Patienten eine Schmerzfreiheit oder wesentliche Besserung der Beschwerden an, zum Zeitpunkt der Fragebogenaktion 76% der Patienten. Die Schmerzbestrahlung degenerativer Skeletterkrankungen erzielte in unserem Patientengut in

  5. Pink lesions.

    Science.gov (United States)

    Giacomel, Jason; Zalaudek, Iris

    2013-10-01

    Dermoscopy (dermatoscopy or surface microscopy) is an ancillary dermatologic tool that in experienced hands can improve the accuracy of diagnosis of a variety of benign and malignant pigmented skin tumors. The early and more accurate diagnosis of nonpigmented, or pink, tumors can also be assisted by dermoscopy. This review focuses on the dermoscopic diagnosis of pink lesions, with emphasis on blood vessel morphology and pattern. A 3-step algorithm is presented, which facilitates the timely and more accurate diagnosis of pink tumors and subsequently guides the management for such lesions.

  6. Disk Defect Data

    Data.gov (United States)

    National Aeronautics and Space Administration — How Data Was Acquired: The data presented is from a physical simulator that simulated engine disks. Sample Rates and Parameter Description: All parameters are...

  7. Verbatim Floppy Disk

    CERN Multimedia

    1976-01-01

    Introduced under the name "Verbatim", Latin for "literally", these disks that sized more than 5¼ inches have become almost universal on dedicated word processing systems and personal computers. This format was replaced more slowly by the 3½-inch format, introduced for the first time in 1982. Compared to today, these large format disks stored very little data. In reality, they could only contain a few pages of text.

  8. 2TB hard disk drive

    CERN Multimedia

    This particular object was used up until 2012 in the Data Centre. It slots into one of the Disk Server trays. Hard disks were invented in the 1950s. They started as large disks up to 20 inches in diameter holding just a few megabytes (link is external). They were originally called "fixed disks" or "Winchesters" (a code name used for a popular IBM product). They later became known as "hard disks" to distinguish them from "floppy disks (link is external)." Hard disks have a hard platter that holds the magnetic medium, as opposed to the flexible plastic film found in tapes and floppies.

  9. MR imaging of degenerative lumbar disc disease emphasizing on signal intensity changes in vertebral body

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Keiko; Ida, Masahiro; Murakami, Yoshitaka; Harada, Junta; Tada, Shimpei (Jikei Univ., Tokyo (Japan). School of Medicine)

    1992-12-01

    Magnetic resonance imaging was performed in 400 patients with degenerative disc disease. Signal changes and their sites in the vertebral body were classified and referred to narrowing of the intervertebral disc space. MR findings were compared with those of plain roentgenograms of the lumbar spine. Signal changes in the vertebral body were noted in 83 cases (102 vertebral bodies). Low-intensity abnormality on both T1- and T2-weighted images (WI) was the most common finding, and was most frequently seen at the end plate and/or the angle. These changes were correlated with narrowing of the disc space and osteosclerosis on the plain roentgenogram of the lumbar spine. Signal changes occasionally occurred in the inner region of the vertebral body, and these lesions tended to show a high-intensity abnormality on T1-WI. We conclude that signal changes in degenerative disc disease are not specific, but are sometimes difficult to distinguish from the signal changes in other conditions such as spinal tumor or bone marrow disorder. (author).

  10. SLAP lesions: a treatment algorithm.

    Science.gov (United States)

    Brockmeyer, Matthias; Tompkins, Marc; Kohn, Dieter M; Lorbach, Olaf

    2016-02-01

    Tears of the superior labrum involving the biceps anchor are a common entity, especially in athletes, and may highly impair shoulder function. If conservative treatment fails, successful arthroscopic repair of symptomatic SLAP lesions has been described in the literature particularly for young athletes. However, the results in throwing athletes are less successful with a significant amount of patients who will not regain their pre-injury level of performance. The clinical results of SLAP repairs in middle-aged and older patients are mixed, with worse results and higher revision rates as compared to younger patients. In this population, tenotomy or tenodesis of the biceps tendon is a viable alternative to SLAP repairs in order to improve clinical outcomes. The present article introduces a treatment algorithm for SLAP lesions based upon the recent literature as well as the authors' clinical experience. The type of lesion, age of patient, concomitant lesions, and functional requirements, as well as sport activity level of the patient, need to be considered. Moreover, normal variations and degenerative changes in the SLAP complex have to be distinguished from "true" SLAP lesions in order to improve results and avoid overtreatment. The suggestion for a treatment algorithm includes: type I: conservative treatment or arthroscopic debridement, type II: SLAP repair or biceps tenotomy/tenodesis, type III: resection of the instable bucket-handle tear, type IV: SLAP repair (biceps tenotomy/tenodesis if >50 % of biceps tendon is affected), type V: Bankart repair and SLAP repair, type VI: resection of the flap and SLAP repair, and type VII: refixation of the anterosuperior labrum and SLAP repair.

  11. The degenerative spine: pattern recognition and guidelines to image interpretation.

    Science.gov (United States)

    Parizel, P M; Van Hoyweghen, A J L; Bali, A; Van Goethem, J; Van Den Hauwe, L

    2016-01-01

    Degenerative disease of the spine, in the form of intervertebral disc degeneration and bony growth, causing osteophytes and impinging upon the spinal canal and neural foramina, is the most frequent disorder affecting the spine. In this chapter we first discuss briefly the indications for computed tomography or magnetic resonance imaging in suspected degenerative spine disease. We then describe changes of disc height, signal intensity, and disc contour with aging and repeated microtrauma, as well as the imaging techniques most appropriate to image them. A grading system for lumbar disc changes is provided. Stenosis of the canal and neural foramina is reviewed next, concluding with a description of degenerative changes affecting the vertebral endplates and bone marrow.

  12. Degenerative lumbar spondylolisthesis: an epidemiological perspective: the Copenhagen Osteoarthritis Study

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Sonne-Holm, Stig; Rovsing, Hans;

    2007-01-01

    STUDY DESIGN: A cross-sectional epidemiological survey of 4151 participants of the Copenhagen Osteoarthritis Study. OBJECTIVE: To identify prevalences and individual risk factors for degenerative lumbar spondylolisthesis. SUMMARY OF BACKGROUND DATA: The Copenhagen Osteoarthritis Study has...... registered health parameters since 1976. In 1993, standardized, lateral radiographs of the lumbar spine were recorded. There were 1533 men and 2618 women. METHODS: Statistical correlations were made between degenerative spondylolisthesis, and physical, occupational, and general epidemiological data. RESULTS......: A total of 254 cases of lumbar slip were found (males 2.7%, females 8.4%). In females, no significant relationship between age at menopause or childbirths and the presence of degenerative spondylolisthesis were found. In women, relationships between body mass index (BMI) in 1976 and L4 olisthesis (P = 0...

  13. Neuromuscular exercise as treatment of degenerative knee disease

    DEFF Research Database (Denmark)

    Ageberg, Eva; Roos, Ewa M.

    2015-01-01

    Exercise is recommended as first-line treatment of degenerative knee disease. Our hypothesis is that neuromuscular exercise is feasible and at least as effective as tradionally used strength or aerobic training, but aims to more closely target the sensorimotor deficiencies and functional instabil......Exercise is recommended as first-line treatment of degenerative knee disease. Our hypothesis is that neuromuscular exercise is feasible and at least as effective as tradionally used strength or aerobic training, but aims to more closely target the sensorimotor deficiencies and functional...... instability associated with the degenerative knee disease than traditionally used training methods.SUMMARY FOR TABLE OF CONTENTS PAGECurrent data suggests that the effect from neuromuscular exercise on pain and function is comparable to the effects seen from other forms of exercise....

  14. Parasellar lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ruscalleda, J. [Hospital Sant Pau, Radiology Department, Neuroradiology, Barcelona (Spain)

    2005-03-01

    The sellar and parasellar region is an anatomically complex area that represents a crucial crossroad of important adjacent structures, e.g. orbits, cavernous sinus and its content, polygon of Willis, hypothalamus through the pituitary stalk and dural reflections forming the diaphragm sellae and the walls of the cavernous sinuses. Although the cavernous sinus represents the most relevant parasellar structure, from the practical and clinical point of view all the structures that surround the sella turcica can be included in the parasellar region. CT and, mainly, MRI are the imaging modalities to study and characterise the normal anatomy and the majority of processes in this region. We present a practical short review of the most relevant CT and MRI characteristics, such as location, nature of contrast enhancement and presence of cystic components, together with clinical findings, which permit differentiation of the most frequent and less common lesions found in the parasellar region. Learning objectives: A short review of the anatomy and clinical symptoms related to the parasellar region. Radiological characterisation, mainly by MRI, of the many lesions that alter the structure and function of sellar and parasellar anatomy. Description of the MRI features that permit differentiation among less common lesions. (orig.)

  15. Destructive discovertebral degenerative disease of the lumbar spine.

    Science.gov (United States)

    Charran, A K; Tony, G; Lalam, R; Tyrrell, P N M; Tins, B; Singh, J; Eisenstein, S M; Balain, B; Trivedi, J M; Cassar-Pullicino, V N

    2012-09-01

    The uncommon variant of degenerative hip joint disease, termed rapidly progressive osteoarthritis, and highlighted by severe joint space loss and osteochondral disintegration, is well established. We present a similar unusual subset in the lumbar spine termed destructive discovertebral degenerative disease (DDDD) with radiological features of vertebral malalignment, severe disc resorption, and "bone sand" formation secondary to vertebral fragmentation. Co-existing metabolic bone disease is likely to promote the development of DDDD of the lumbar spine, which presents with back pain and sciatica due to nerve root compression by the "bone sand" in the epidural space. MRI and CT play a complimentary role in making the diagnosis.

  16. Dispersion in unit disks

    CERN Document Server

    Dumitrescu, Adrian

    2009-01-01

    We present two new approximation algorithms with (improved) constant ratios for selecting $n$ points in $n$ unit disks such that the minimum pairwise distance among the points is maximized. (I) A very simple $O(n \\log{n})$-time algorithm with ratio 0.5110 for disjoint unit disks. In combination with an algorithm of Cabello \\cite{Ca07}, it yields a $O(n^2)$-time algorithm with ratio of 0.4487 for dispersion in $n$ not necessarily disjoint unit disks. (II) A more sophisticated LP-based algorithm with ratio 0.6495 for disjoint unit disks that uses a linear number of variables and constraints, and runs in polynomial time. The algorithm introduces a novel technique which combines linear programming and projections for approximating distances. The previous best approximation ratio for disjoint unit disks was 1/2. Our results give a partial answer to an open question raised by Cabello \\cite{Ca07}, who asked whether 1/2 could be improved.

  17. ‘Lumbar Degenerative Kyphosis’ Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception

    Science.gov (United States)

    Lee, Chang-Hyun; Chung, Chun Kee; Jang, Jee-Soo; Kim, Sung-Min; Chin, Dong-Kyu; Lee, Jung-Kil

    2017-01-01

    Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal deformity. Unlike what its name suggests, LDK does not only include sagittal balance disorder of the lumbar spine and kyphosis, but also sagittal balance disorder of the whole spine and little lordosis of the lumbar spine. Moreover, this disease is closely related to the occupation of female farmers and an outdated Asian life style. These reasons necessitate a change in the nomenclature of this disorder to prevent misunderstanding. We suggest the name “primary degenerative sagittal imbalance” (PDSI), which encompasses degenerative sagittal misalignments of unknown origin in the whole spine in older-age patients, and is associated with back muscle wasting. LDK may be regarded as a subgroup of PDSI related to an occupation in agriculture. Conservative treatments such as exercise and physiotherapy are recommended as first-line treatments for patients with PDSI, and surgical treatment is considered only if conservative treatments failed. The measurement of spinopelvic parameters for sagittal balance is important prior to deformity corrective surgery. LDK can be considered a subtype of PDSI that is more likely to occur in female farmers, and hence the use of LDK as a global term for all degenerative sagittal imbalance disorders is better avoided. To avoid confusion, we recommend PDSI as a newer, more accurate diagnostic term instead of LDK. PMID:28264231

  18. Silica in Protoplanetary Disks

    CERN Document Server

    Sargent, B A; Tayrien, C; McClure, M K; Li, A; Basu, A R; Manoj, P; Watson, D M; Bohac, C J; Furlan, E; Kim, K H; Green, J D; Sloan, G C

    2008-01-01

    Mid-infrared spectra of a few T Tauri stars (TTS) taken with the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope show prominent narrow emission features indicating silica (crystalline silicon dioxide). Silica is not a major constituent of the interstellar medium; therefore, any silica present in the circumstellar protoplanetary disks of TTS must be largely the result of processing of primitive dust material in the disks surrouding these stars. We model the silica emission features in our spectra using the opacities of various polymorphs of silica and their amorphous versions computed from earth-based laboratory measurements. This modeling indicates that the two polymorphs of silica, tridymite and cristobalite, which form at successively higher temperatures and low pressures, are the dominant forms of silica in the TTS of our sample. These high temperature, low pressure polymorphs of silica present in protoplanetary disks are consistent with a grain composed mostly of tridymite named Ada found...

  19. Chemistry in Protoplanetary Disks

    CERN Document Server

    Semenov, Dmitry

    2010-01-01

    Protoplanetary disks (PPDs) surrounding young stars are short-lived (~0.3-10 Myr), compact (~10-1000 AU) rotating reservoirs of gas and dust. PPDs are believed to be birthplaces of planetary systems, where tiny grains are assembled into pebbles, then rocks, planetesimals, and eventually planets, asteroids, and comets. Strong variations of physical conditions (temperature, density, ionization rate, UV/X-rays intensities) make a variety of chemical processes active in disks, producing simple molecules in the gas phase and complex polyatomic (organic) species on the surfaces of dust particles. In this entry, we summarize the major modern observational methods and theoretical paradigms used to investigate disk chemical composition and evolution, and present the most important results. Future research directions that will become possible with the advent of the Atacama Large Millimeter Array (ALMA) and other forthcoming observational facilities are also discussed.

  20. From Disks to Planets

    Science.gov (United States)

    Youdin, Andrew N.; Kenyon, Scott J.

    This pedagogical chapter covers the theory of planet formation, with an emphasis on the physical processes relevant to current research. After summarizing empirical constraints from astronomical and geophysical data, we describe the structure and evolution of protoplanetary disks. We consider the growth of planetesimals and of larger solid protoplanets, followed by the accretion of planetary atmospheres, including the core accretion instability. We also examine the possibility that gas disks fragment directly into giant planets and/or brown dwarfs. We defer a detailed description of planet migration and dynamical evolution to other work, such as the complementary chapter in this series by Morbidelli.

  1. Lupus Alma Disk Survey

    Science.gov (United States)

    Ansdell, Megan

    2016-07-01

    We present the first unbiased ALMA survey of both dust and gas in a large sample of protoplanetary disks. We surveyed 100 sources in the nearby (150-200 pc), young (1-2 Myr) Lupus region to constrain M_dust to 2 M_Mars and M_gas to 1 M_Jup. Most disks have masses < MMSN and gas-to-dust ratios < ISM. Such rapid gas depletion may explain the prevalence of super-Earths in the exoplanet population.

  2. Vitiligo: a possible model of degenerative diseases.

    Directory of Open Access Journals (Sweden)

    Barbara Bellei

    Full Text Available Vitiligo is characterized by the progressive disappearance of pigment cells from skin and hair follicle. Several in vitro and in vivo studies show evidence of an altered redox status, suggesting that loss of cellular redox equilibrium might be the pathogenic mechanism in vitiligo. However, despite the numerous data supporting a pathogenic role of oxidative stress, there is still no consensus explanation underlying the oxidative stress-driven disappear of melanocytes from the epidermis. In this study, in vitro characterization of melanocytes cultures from non-lesional vitiligo skin revealed at the cellular level aberrant function of signal transduction pathways common with neurodegenerative diseases including modification of lipid metabolism, hyperactivation of mitogen-activated protein kinase (MAPK and cAMP response element-binding protein (CREB, constitutive p53-dependent stress signal transduction cascades, and enhanced sensibility to pro-apoptotic stimuli. Notably, these long-term effects of subcytotoxic oxidative stress are also biomarkers of pre-senescent cellular phenotype. Consistent with this, vitiligo cells showed a significant increase in p16 that did not correlate with the chronological age of the donor. Moreover, vitiligo melanocytes produced many biologically active proteins among the senescence-associated secretory phenotype (SAPS, such as interleukin-6 (IL-6, matrix metallo proteinase-3 (MMP3, cyclooxygenase-2 (Cox-2, insulin-like growth factor-binding protein-3 and 7 (IGFBP3, IGFBP7. Together, these data argue for a complicated pathophysiologic puzzle underlying melanocytes degeneration resembling, from the biological point of view, neurodegenerative diseases. Our results suggest new possible targets for intervention that in combination with current therapies could correct melanocytes intrinsic defects.

  3. Vitiligo: A Possible Model of Degenerative Diseases

    Science.gov (United States)

    Bellei, Barbara; Pitisci, Angela; Ottaviani, Monica; Ludovici, Matteo; Cota, Carlo; Luzi, Fabiola; Dell'Anna, Maria Lucia; Picardo, Mauro

    2013-01-01

    Vitiligo is characterized by the progressive disappearance of pigment cells from skin and hair follicle. Several in vitro and in vivo studies show evidence of an altered redox status, suggesting that loss of cellular redox equilibrium might be the pathogenic mechanism in vitiligo. However, despite the numerous data supporting a pathogenic role of oxidative stress, there is still no consensus explanation underlying the oxidative stress-driven disappear of melanocytes from the epidermis. In this study, in vitro characterization of melanocytes cultures from non-lesional vitiligo skin revealed at the cellular level aberrant function of signal transduction pathways common with neurodegenerative diseases including modification of lipid metabolism, hyperactivation of mitogen-activated protein kinase (MAPK) and cAMP response element-binding protein (CREB), constitutive p53-dependent stress signal transduction cascades, and enhanced sensibility to pro-apoptotic stimuli. Notably, these long-term effects of subcytotoxic oxidative stress are also biomarkers of pre-senescent cellular phenotype. Consistent with this, vitiligo cells showed a significant increase in p16 that did not correlate with the chronological age of the donor. Moreover, vitiligo melanocytes produced many biologically active proteins among the senescence-associated secretory phenotype (SAPS), such as interleukin-6 (IL-6), matrix metallo proteinase-3 (MMP3), cyclooxygenase-2 (Cox-2), insulin-like growth factor-binding protein-3 and 7 (IGFBP3, IGFBP7). Together, these data argue for a complicated pathophysiologic puzzle underlying melanocytes degeneration resembling, from the biological point of view, neurodegenerative diseases. Our results suggest new possible targets for intervention that in combination with current therapies could correct melanocytes intrinsic defects. PMID:23555779

  4. Vitiligo: a possible model of degenerative diseases.

    Science.gov (United States)

    Bellei, Barbara; Pitisci, Angela; Ottaviani, Monica; Ludovici, Matteo; Cota, Carlo; Luzi, Fabiola; Dell'Anna, Maria Lucia; Picardo, Mauro

    2013-01-01

    Vitiligo is characterized by the progressive disappearance of pigment cells from skin and hair follicle. Several in vitro and in vivo studies show evidence of an altered redox status, suggesting that loss of cellular redox equilibrium might be the pathogenic mechanism in vitiligo. However, despite the numerous data supporting a pathogenic role of oxidative stress, there is still no consensus explanation underlying the oxidative stress-driven disappear of melanocytes from the epidermis. In this study, in vitro characterization of melanocytes cultures from non-lesional vitiligo skin revealed at the cellular level aberrant function of signal transduction pathways common with neurodegenerative diseases including modification of lipid metabolism, hyperactivation of mitogen-activated protein kinase (MAPK) and cAMP response element-binding protein (CREB), constitutive p53-dependent stress signal transduction cascades, and enhanced sensibility to pro-apoptotic stimuli. Notably, these long-term effects of subcytotoxic oxidative stress are also biomarkers of pre-senescent cellular phenotype. Consistent with this, vitiligo cells showed a significant increase in p16 that did not correlate with the chronological age of the donor. Moreover, vitiligo melanocytes produced many biologically active proteins among the senescence-associated secretory phenotype (SAPS), such as interleukin-6 (IL-6), matrix metallo proteinase-3 (MMP3), cyclooxygenase-2 (Cox-2), insulin-like growth factor-binding protein-3 and 7 (IGFBP3, IGFBP7). Together, these data argue for a complicated pathophysiologic puzzle underlying melanocytes degeneration resembling, from the biological point of view, neurodegenerative diseases. Our results suggest new possible targets for intervention that in combination with current therapies could correct melanocytes intrinsic defects.

  5. Effects of interspinous spacers on lumbar degenerative disease.

    Science.gov (United States)

    Zhou, Dong; Nong, Lu-Ming; DU, Rui; Gao, Gong-Ming; Jiang, Yu-Qing; Xu, Nan-Wei

    2013-03-01

    The present study aimed to evaluate the early effects of interspinous spacers on lumbar degenerative disease. The clinical outcomes of 23 patients with lumbar degenerative disease, treated using interspinous spacer implantation alone or combined with posterior lumbar fusion, were retrospectively studied and assessed with a visual analogue scale (VAS) and the Oswestry Disability Index (ODI). Pre-operative and post-operative interspinous distance, disc space height, foraminal width and height and segmental lordosis were determined. The early effects and complications associated with the interspinous spacers were recorded. The surgical procedures performed with the in-space treatment were easy and minimally invasive. The VAS scores and ODI were improved post-operatively compared with pre-operatively. Significant changes in the interspinous distance, disc space height, foraminal width and height and segmental lordosis were noted. In-space treatment for degenerative lumbar disease is easy and safe, with good early effects. The in-space system provides an alternative treatment for lumbar degenerative disease.

  6. Degenerative lumbar spondylolisthesis: an epidemiological perspective: the Copenhagen Osteoarthritis Study

    DEFF Research Database (Denmark)

    Jacobsen, Steffen; Sonne-Holm, Stig; Rovsing, Hans

    2007-01-01

    : A total of 254 cases of lumbar slip were found (males 2.7%, females 8.4%). In females, no significant relationship between age at menopause or childbirths and the presence of degenerative spondylolisthesis were found. In women, relationships between body mass index (BMI) in 1976 and L4 olisthesis (P = 0...

  7. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders

    Institute of Scientific and Technical Information of China (English)

    Natalie Kaminsky; Ofer Bihari; Sivan Kanner; Ari Barzilai

    2016-01-01

    The DNA damage response (DDR) is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to geno-mic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degener-ative disorders such as Parkinson’s, Alzheimer’s, and Huntington’s diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evi-dence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes). Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a‘‘hostile”environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit.

  8. Degenerative spondylolisthesis is associated with low spinal bone density

    DEFF Research Database (Denmark)

    Andersen, Thomas; Christensen, Finn B; Langdahl, Bente Lomholt

    2013-01-01

    Spinal stenosis and degenerative spondylolisthesis share many symptoms and the same treatment, but their causes remain unclear. Bone mineral density has been suggested to play a role. The aim of this study was to investigate differences in spinal bone density between spinal stenosis and degenerat...

  9. 78 FR 65450 - Agency Information Collection (Non-Degenerative Arthritis (Including Inflammatory, Autoimmune...

    Science.gov (United States)

    2013-10-31

    ... AFFAIRS Agency Information Collection (Non-Degenerative Arthritis (Including Inflammatory, Autoimmune... (including inflammatory, autoimmune, crystalline and infectious arthritis) and Dysbaric Osteonecrosis...-Degenerative Arthritis (including inflammatory, autoimmune, crystalline and infectious arthritis) and...

  10. [Sagittal balance of the spine and degenerative spondylolisthesis].

    Science.gov (United States)

    Morel, E; Ilharreborde, B; Lenoir, T; Hoffmann, E; Vialle, R; Rillardon, L; Guigui, P

    2005-11-01

    Several reports have examined the pathophysiology of degenerative spondylolisthesis. Very little work has however been devoted to the influence of spinal balance in the sagittal plane in its pathogenesis. The purpose of this work was to present a descriptive analysis of pelvic and spinal sagittal balance in a cohort of seventy patients treated for degenerative spondylolisthesis and to compare findings with those established in a population of 250 volunteers. The goal was to deduct pathophysiological hypotheses and identify therapeutic implications. Seventy patients were included in this study. The following variables were noted: pelvic incidence and version, sacral slope, lumbar lordosis, thoracic kyphosis, T9 sagittal tilt and S1-S2 angle. These variables were measured on digitalized lateral views of the spine using a dedicated software (SpineView). Univariate analysis of the values obtained was performed to identify the variable distributions. Multivariate analysis was applied to study the relationships between these variables and to better define perturbations of spinal balance in the anteroposterior plane. The findings were compared with those obtained in a control population. One of the essential characteristics of the cohort of patients with degenerative spondylolisthesis was the presence of an exaggerated pelvic incidence (62.6 degrees versus 54.7 degrees in the control population). The most significant determinants of T9 sagittal tilt (which reflects sagittal balance) were: pelvic version, pelvic incidence, lumbar lordosis, and L4-S1 local lordosis. One-third of our patients presented posterior tilt due to exaggerated thoracic kyphosis. The high pelvic incidence, via hyperlordosis and increased pelvic version, could be one of the factors favoring degenerative disease of the spinal unit. This work enabled us to better describe sagittal balance in patients with degenerative spondylolisthesis and to propose hypotheses concerning the underlying mechanism of

  11. Polarimetric microlensing of circumstellar disks

    CERN Document Server

    Sajadian, Sedighe

    2015-01-01

    We study the benefits of polarimetry observations of microlensing events to detect and characterize circumstellar disks around the microlensed stars located at the Galactic bulge. These disks which are unresolvable from their host stars make a net polarization effect due to their projected elliptical shapes. Gravitational microlensing can magnify these signals and make them be resolved. The main aim of this work is to determine what extra information about these disks can be extracted from polarimetry observations of microlensing events in addition to those given by photometry ones. Hot disks which are closer to their host stars are more likely to be detected by microlensing, owing to more contributions in the total flux. By considering this kind of disks, we show that although the polarimetric efficiency for detecting disks is similar to the photometric observation, but polarimetry observations can help to constraint the disk geometrical parameters e.g. the disk inner radius and the lens trajectory with resp...

  12. Warm gas in protoplanetary disks

    Science.gov (United States)

    van der Plas, Gerrit

    2010-12-01

    This thesis presents a study of warm CO, [OI] and H2 gas coming from the disks around Herbig Ae/Be stars. These various gas tracers are each a proxy for a different radial and vertical region of the PP disk surface. Our sample consists of disks whose shape (based on modeling of the the disk dust emission) can be divided into flaring and self-shadowed (flat). We find [1] evidence for the vertical decoupling of gas and dust in one disks (Chapter 2); [2] That disk geometry has a large influence on the spatial distribution and excitation mechanism of the CO emission (chapters 3,4); [3] Near-IR H 2 emission around 2 (out of 14) HAEBE stars, probably originating from large (±50AU) radii of the disk (chapter 5). In chapter 6 we investigate the trends between CO emission and disk geometry as noted in Chapter 3 and 4.

  13. Galactic Thin Disk

    NARCIS (Netherlands)

    van der Kruit, P.; Murdin, P.; Murdin, Paul

    2000-01-01

    Of the components of our MILKY WAY GALAXY, the thin disk is the most prominent part to our eyes. It manifests itself as the band of faint light that we see encircling the whole sky. Except for the bulge in the direction of the center of our Galaxy, the stars that make up the Milky Way as we see it

  14. More approximation on disks

    NARCIS (Netherlands)

    de Paepe, P.J.I.M.; Wiegerinck, J.J.O.O.

    2007-01-01

    Abstract: In this article we study the function algebra generated by z2 and g2 on a small closed disk centred at the origin of the complex plane. We prove, using a biholomorphic change of coordinates and already developed techniques in this area, that for a large class of functions g this algebra co

  15. Herniated disk repair (image)

    Science.gov (United States)

    ... is one of the most common causes of lower back pain. The mainstay of treatment for herniated disks is an initial period of rest with pain and anti-inflammatory medications followed by physical therapy. If pain and symptoms persist, surgery to remove ...

  16. The Tilt between Acretion Disk and Stellar Disk

    Indian Academy of Sciences (India)

    Shiyin Shen; Zhengyi Shao; Minfeng Gu

    2011-03-01

    The orientations of the accretion disk of active galactic nuclei (AGN) and the stellar disk of its host galaxy are both determined by the angular momentum of their forming gas, but on very different physical environments and spatial scales. Here we show the evidence that the orientation of the stellar disk is correlated with the accretion disk by comparing the inclinations of the stellar disks of a large sample of Type 2 AGNs selected from Sloan Digital Sky Survey (SDSS, York et al. 2000) to a control galaxy sample. Given that the Type 2 AGN fraction is in the range of 70–90 percent for low luminosity AGNs as a priori, we find that the mean tilt between the accretion disk and stellar disk is ∼ 30 degrees (Shen et al. 2010).

  17. {sup 18}F-FDG PET in neuro-degenerative Langerhans cell histiocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, M.Jo. [CEA, DSV, DRM, Serv Hosp Frederic Joliot, F-91406 Orsay (France); Idbaih, A.; Hoang-Xuan, K. [UPMC, Grp Hosp Pitie Salpetriere, ServNeurol Mazarin, AP-HP, Paris (France); Thomas, C. [CHU Nantes, Unite Hematol et Oncol Pediat, F-44035 Nantes 01 (France); Remy, P. [CEA, Serv Hosp Frederic Joliot, CNRS, URA 2210, F-91406 Orsay (France); Remy, P. [CHU Henri Mondor, Fac Med Paris 12, Dept Neurosci, AP-HP, F-94010 Creteil (France)

    2008-07-01

    Introduction: The so called 'neuro-degenerative Langerhans cell histiocytosis' (ND-LCH) is a rare and severe complication of LCH presenting as a progressive cerebellar ataxia associated with pyramidal tract signs, and cognitive impairment. MRI is the gold standard to investigate CNS lesions of ND-LCH but little is known about functional changes observed in this disease. Objectives: To search for CNS metabolic changes in NDLCH. Methods: Seven patients suffering from ND-LCH were investigated by {sup 18}F-FDG PET in this prospective study and compared with 21 healthy controls. Results: ND-LCH patients demonstrated recurrent abnormalities including bilateral hypo-metabolism in the cerebellum, the basal ganglia (caudate nuclei), frontal cortex and, bilateral, a relatively increased metabolism in the amygdalae (p {<=} 0.001). Functional changes in these anatomical regions may be detected in the absence of any apparent lesion on MRI. Conclusions: ND-LCH demonstrates a recurrent {sup 18}F-FDG PET metabolic signature. Our results suggest that {sup 18}F-FDG PET might be a useful tool for an early diagnosis of ND-LCH before neuro-radiologic abnormalities appear. (authors)

  18. [Intradural lumbar disk hernia].

    Science.gov (United States)

    Alonso-Bartolomé, P; Canga, A; Vázquez-Barquero, A; García-Valtuille, R; Abascal, F; Cerezal, L

    2001-04-01

    Intradural disc herniation is a rare complication of degenerative disc disease. A correct diagnosis of this process is frequently difficult. If this entity is not preoperatively diagnosed and is omitted at surgery, severe neurologic sequels may be provoked. We report a case of a pathologically proven intradural disc herniation preoperatively diagnosed by MR imaging. Clinically, it was manifested by sudden onset of right leg ciatalgia and progressive right lower extremity weakness. The patient also referred a one-month history of sexual dysfunction. MR imaging revealed interruption of the low signal of the anulus fibrosus and of the posterior longitudinal ligament at L2-L3 level and a voluminous disc fragment migrated in the dural sac that showed rim enhancement with gadolinium.The clinical, neuroradiological, and surgical management of lumbar intradural disc herniation are reviewed.

  19. Vibration of imperfect rotating disk

    Directory of Open Access Journals (Sweden)

    Půst L.

    2011-12-01

    Full Text Available This study is concerned with the theoretical and numerical calculations of the flexural vibrations of a bladed disk. The main focus of this study is to elaborate the basic background for diagnostic and identification methods for ascertaining the main properties of the real structure or an experimental model of turbine disks. The reduction of undesirable vibrations of blades is proposed by using damping heads, which on the experimental model of turbine disk are applied only on a limited number of blades. This partial setting of damping heads introduces imperfection in mass, stiffness and damping distribution on the periphery and leads to more complicated dynamic properties than those of a perfect disk. Calculation of FEM model and analytic—numerical solution of disk behaviour in the limited (two modes frequency range shows the splitting of resonance with an increasing speed of disk rotation. The spectrum of resonance is twice denser than that of a perfect disk.

  20. Volatiles in protoplanetary disks

    CERN Document Server

    Pontoppidan, Klaus M; Bergin, Edwin A; Brittain, Sean; Marty, Bernard; Mousis, Olvier; Oberg, Karin L

    2014-01-01

    Volatiles are compounds with low sublimation temperatures, and they make up most of the condensible mass in typical planet-forming environments. They consist of relatively small, often hydrogenated, molecules based on the abundant elements carbon, nitrogen and oxygen. Volatiles are central to the process of planet formation, forming the backbone of a rich chemistry that sets the initial conditions for the formation of planetary atmospheres, and act as a solid mass reservoir catalyzing the formation of planets and planetesimals. This growth has been driven by rapid advances in observations and models of protoplanetary disks, and by a deepening understanding of the cosmochemistry of the solar system. Indeed, it is only in the past few years that representative samples of molecules have been discovered in great abundance throughout protoplanetary disks - enough to begin building a complete budget for the most abundant elements after hydrogen and helium. The spatial distributions of key volatiles are being mapped...

  1. DEGENERATIVE AORTIC STENOSIS: PATHOGENESIS AND NEW PRINCIPLES OF TREATMENT

    Directory of Open Access Journals (Sweden)

    O. V. Andropova

    2006-01-01

    Full Text Available Aim. To reveal of markers of inflammation and progression of calcification in patients with degenerative aortic stenosis (DAS. Material and methods. A single-stage study was done in 85 patients with degenerative calcification of aortic valve (42 patients with DAS and 43 patients without DAS. The techniques for assessing the severity of aortic valve calcification included ultrasonic diagnostics and multislice spiral computed tomography. Markers of inflammation and lipid profile were investigated.    Results. Higher blood levels of total holesterol and holesterol of low density lipoprotein were revealed in patients with DAS in comparison with patients without DAS. They also had higher levels of inflammation markers: C-reactive protein and interleukin-6. There were significant correlations between DAS severity, lipid metabolism disturbances and inflammation markers. Conclusion. Atherogenesis and inflammation may have pathogenic influence on progression of aortic valve calcification and DAS development by lipid infiltration and endothelium cells damage.

  2. Photobiomodulation on human annulus fibrosus cells during the intervertebral disk degeneration: extracellular matrix-modifying enzymes.

    Science.gov (United States)

    Hwang, Min Ho; Kim, Kyoung Soo; Yoo, Chang Min; Shin, Jae Hee; Nam, Hyo Geun; Jeong, Jin Su; Kim, Joo Han; Lee, Kwang Ho; Choi, Hyuk

    2016-05-01

    Destruction of extracellular matrix (ECM) leads to degeneration of the intervertebral disk (IVD), which is a major contributor to many spine disorders. IVD degeneration is induced by pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), which are secreted by immune cells, including macrophages and neutrophils. The cytokines modulate ECM-modifying enzymes such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human annulus fibrosus (AF) cells. The resulting imbalance in catabolic and anabolic enzymes can cause generalized back, neck, and low back pain (LBP). Photobiomodulation (PBM) is known to regulate inflammatory responses and wound healing. The aim of this study was to mimic the degenerative IVD microenvironment, and to investigate the effect of a variety of PBM conditions (wavelength: 635, 525, and 470 nm; energy density: 16, 32, and 64 J/cm(2)) on the production of ECM-modifying-enzymes by AF cells under degenerative conditions induced by macrophage-conditioned medium (MCM), which contains pro-inflammatory cytokines such as TNF-α and IL-β secreted by macrophage during the development of intervertebral disk inflammation. We showed that the MCM-stimulated AF cells express imbalanced ratios of TIMPs (TIMP-1 and TIMP-2) and MMPs (MMP-1 and MMP-3). PBM selectively modulated the production of ECM-modifying enzymes in AF cells. These results suggest that PBM can be a therapeutic tool for degenerative IVD disorders.

  3. The Evolution of Inner Disk Gas in Transition Disks

    CERN Document Server

    Hoadley, Keri; Alexander, Richard D; McJunkin, Matthew; Schneider, Christian

    2015-01-01

    Investigating the molecular gas in the inner regions of protoplanetary disks provides insight into how the molecular disk environment changes during the transition from primordial to debris disk systems. We conduct a small survey of molecular hydrogen (H$_2$) fluorescent emission, using 14 well-studied Classical T Tauri stars at two distinct dust disk evolutionary stages, to explore how the structure of the inner molecular disk changes as the optically thick warm dust dissipates. We simulate the observed HI-Lyman $\\alpha$-pumped H$_2$ disk fluorescence by creating a 2D radiative transfer model that describes the radial distributions of H$_{2}$ emission in the disk atmosphere and compare these to observations from the Hubble Space Telescope. We find the radial distributions that best describe the observed H$_2$ FUV emission arising in primordial disk targets (full dust disk) are demonstrably different than those of transition disks (little-to-no warm dust observed). For each best-fit model, we estimate inner a...

  4. Adjacent segment disease in degenerative pathologies with posterior instrumentation

    OpenAIRE

    Ana Guadalupe Ramírez Olvera; Manuel Villarreal Arroyo; Luis Mario Hinojosa Martínez; Enrique Méndez Pérez; Luis Romeo Ramos Hinojosa

    2015-01-01

    OBJECTIVE: To establish the real incidence of adjacent segment disease after fusion, and to identify the levels and predisposing factors for the pathology, as well as the functional results. METHODS: a retrospective case series study with level of evidence IIB, in a sample of 179 patients diagnosed with stenosis of the lumbar spine, spondylolisthesis and degenerative scoliosis, submitted to surgery in the period 2005 to December 2013, with posterior instrumentation and posterolateral fusion, ...

  5. Sagittal Balance Correction in Lateral Interbody Fusion for Degenerative Scoliosis

    Science.gov (United States)

    Gallizzi, Michael A.; Sheets, Charles; Smith, Benjamin T.; Isaacs, Robert E.; Eure, Megan; Brown, Christopher R.

    2016-01-01

    Background Sagittal balance restoration has been shown to be an important determinant of outcomes in corrective surgery for degenerative scoliosis. Lateral interbody fusion (LIF) is a less-invasive technique which permits the placement of a high lordosis interbody cage without risks associated with traditional anterior or transforaminal interbody techniques. Studies have shown improvement in lumbar lordosis following LIF, but only one other study has assessed sagittal balance in this population. The objective of this study is to evaluate the ability of LIF to restore sagittal balance in degenerative lumbar scoliosis. Methods Thirty-five patients who underwent LIF for degenerative thoracolumbar scoliosis from July 2013 to March 2014 by a single surgeon were included. Outcome measures included sagittal balance, lumbar lordosis, Cobb Angle, and segmental lordosis. Measures were evaluated pre-operative, immediately post-operatively, and at their last clinical follow-up. Repeated measures ANOVAs were used to assess the differences between pre-operative, first postoperative, and a follow-up visit. Results The average sagittal balance correction was not significantly different: 1.06cm from 5.79cm to 4.74cm forward. The average Cobb angle correction was 14.1 degrees from 21.6 to 5.5 degrees. The average change in global lumbar lordosis was found to be significantly different: 6.3 degrees from 28.9 to 35.2 degrees. Conclusions This study demonstrates that LIF reliably restores lordosis, but does not significantly improve sagittal balance. Despite this, patients had reliable improvement in pain and functionality suggesting that sagittal balance correction may not be as critical in scoliosis correction as previous studies have indicated. Clinical Relevance LIF does not significantly change sagittal balance; however, clinical improvement does not seem to be contingent upon sagittal balance correction in the degenerative scoliosis population. The DUHS IRB has determined this

  6. NONOPERATIVE VERSUS OPERATIVE TREATMENT OF PATIENTS WITH DEGENERATIVE SPONDYLOLISTHESIS

    Directory of Open Access Journals (Sweden)

    Jose Alfredo Corredor

    2016-03-01

    Full Text Available ABSTRACT Objective: To evaluate clinical and functional results of patients with lumbar degenerative spondylolisthesis treated with operatively or nonoperatively. Methods: Patients with degenerative spondylolisthesis treated either nonoperatively or operatively from 2004 to 2014 were selected from databases and a cross-sectional evaluation was performed. Outcome measures included back and leg visual analogue scales (VAS, Fischgrund criteria, Short Form-36 (SF-36 function score, and the modified Oswestry Disability Index (ODI. Results: 43 patients were evaluated: 20 with nonoperative treatment and 23 with operative treatment. Baseline characteristics were similar without significant differences between groups. Mean follow-up time was 43 months (range 10 - 72 for the nonoperative group and 36 months (range 6-80 for the operative group. Significant statistical difference in favor of operative group were found in back VAS (mean 4 versus 8, p = 0.000, leg VAS (mean 3 versus 6, p = 0.0015, SF-36 function score (mean 77 versus 35, p = 0.000, and ODI (mean 17 versus 46, p = 0.000. On the basis of the Fischgrund criteria, only 10 % of patients reported excellent or good health post nonoperative treatment versus 83% for those treated operatively (p = 0.000. Conclusion: In this cross-sectional study, we observed that symptomatic patients with degenerative spondylolisthesis who underwent operative treatment have superior clinical and functional scores compared to those that underwent nonoperative treatment.

  7. Adjacent segment disease in degenerative pathologies with posterior instrumentation

    Directory of Open Access Journals (Sweden)

    Ana Guadalupe Ramírez Olvera

    2015-03-01

    Full Text Available OBJECTIVE: To establish the real incidence of adjacent segment disease after fusion, and to identify the levels and predisposing factors for the pathology, as well as the functional results. METHODS: a retrospective case series study with level of evidence IIB, in a sample of 179 patients diagnosed with stenosis of the lumbar spine, spondylolisthesis and degenerative scoliosis, submitted to surgery in the period 2005 to December 2013, with posterior instrumentation and posterolateral fusion, with follow-up from 2007 until May 2014, in which the symptomology and radiographic findings were evaluated, to establish the diagnosis and treatment. RESULTS: the study included 179 patients diagnosed with stenosis of the lumbar spine (n=116, isthmic and degenerative spondylolisthesis (n=50 and degenerative scoliosis (n=13; during the study, 20 cases of adjacent level segment were identified, 80% of which were treated surgically with extension of the instrumentation, while 20% were treated conservatively with NSAIDs and therapeutic blocks. CONCLUSION: An incidence of 11% was found, with an average of 3.25 years in diagnosis and treatment, a prevalence of females and diagnosis of stenosis of the lumbar canal on posterior instrumentation, a predominance of levels L4-L5; 80% were treated with extension of the instrumentation. The complications were persistent radiculopathy, infection of the surgical wound, and one death due to causes not related to the lumbar pathology.

  8. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders

    Directory of Open Access Journals (Sweden)

    Natalie Kaminsky

    2016-06-01

    Full Text Available The DNA damage response (DDR is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to genomic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degenerative disorders such as Parkinson’s, Alzheimer’s, and Huntington’s diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evidence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes. Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a “hostile” environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit.

  9. Pathogenicity of Fusarium avenaceum isolates to tulip leaves assessed on leaf disks

    Directory of Open Access Journals (Sweden)

    Agnieszka Piwoni

    2013-12-01

    Full Text Available The purpose of this study was to investigate the pathogenicity of 14 Fusarium avenaceum (Giberella avenacea isolates, obtained from tulip plantations located in Puławy region, to leaves of tulip cv. Apeldoorn. Mycelial plugs 3 mm in diameter from the margins of the colonies growing on PDA and SNA were placed on 20 mm disks cut from tulip leaves. The disks were placed abaxial surface up, in Petri dishes on top of filter paper soaked with 100 mg/l gibberellic acid to retard leaf senescence. There were 5 replications for each isolate. Leaves in each Petń dish were inoculated with one isolate. Plates were incubated at 20°C and lesion diameters were measured after 4 days. The pathogenicity of investigated isolates was compared by measuring lesion development on tulip leaves. All of isolates colonized leaves disks succesfull - causing after 4 days necrotic lesions and sporulating after 14 days what indicated that an infection had occurred. There were significant differences in lesions size among isolates. Isolates: 27, 1, 2, 48 and 3 caused largest lesions at mean size from 150 mm2 to 163 mm2 what indicates their high pathogenicity. Less pathogenic were isolates: 28, 42, 7 and 72 caused lesions at mean size from 46 mm2 to 97 mm~2. On average, mycelial plugs taken from PDA medium colonized leaf disks more efficient in comparison to them taken from SNA, that caused smaller lesions.

  10. DVD - digital versatile disks

    Energy Technology Data Exchange (ETDEWEB)

    Gaunt, R.

    1997-05-01

    An international standard has emerged for the first true multimedia format. Digital Versatile Disk (by its official name), you may know it as Digital Video Disks. DVD has applications in movies, music, games, information CD-ROMS, and many other areas where massive amounts of digital information is needed. Did I say massive amounts of data? Would you believe over 17 gigabytes on a single piece of plastic the size of an audio-CD? That`s the promise, at least, by the group of nine electronics manufacturers who have agreed to the format specification, and who hope to make this goal a reality by 1998. In this major agreement, which didn`t come easily, the manufacturers will combine Sony and Phillip`s one side double-layer NMCD format with Toshiba and Matsushita`s double sided Super-Density disk. By Spring of this year, they plan to market the first 4.7 gigabyte units. The question is: Will DVD take off? Some believe that read-only disks recorded with movies will be about as popular as video laser disks. They say that until the eraseable/writable DVD arrives, the consumer will most likely not buy it. Also, DVD has a good market for replacement of CD- Roms. Back in the early 80`s, the international committee deciding the format of the audio compact disk decided its length would be 73 minutes. This, they declared, would allow Beethoven`s 9th Symphony to be contained entirely on a single CD. Similarly, today it was agreed that playback length of a single sided, single layer DVD would be 133 minutes, long enough to hold 94% of all feature-length movies. Further, audio can be in Dolby`s AC-3 stereo or 5.1 tracks of surround sound, better than CD-quality audio (16-bits at 48kHz). In addition, there are three to five language tracks, copy protection and parental ``locks`` for R rated movies. DVD will be backwards compatible with current CD-ROM and audio CD formats. Added versatility comes by way of multiple aspect rations: 4:3 pan-scan, 4:3 letterbox, and 16:9 widescreen. MPEG

  11. [Air embolism during lumbar discal hernia repair. Retroperioneal vessels lesions have to be suspected].

    Science.gov (United States)

    Lieutaud, T; Terrier, A; Linne, M; Farhat, F; Tahon, F

    2006-03-01

    Occurrence of deep PETCO(2) drop during surgical lumbar disk repair is rare but dramatic. This case report leads to the diagnosis of retroperitoneal vessels lesions. We review the different diagnosis related to the drop of the PETCO(2) during surgery in the genupectoral position. We recommend that the diagnosis of retroperitoneal vessels lesion have to be suspected early if air embolism occurs during lumbar disk surgery.

  12. Audit: Automated Disk Investigation Toolkit

    Directory of Open Access Journals (Sweden)

    Umit Karabiyik

    2014-09-01

    Full Text Available Software tools designed for disk analysis play a critical role today in forensics investigations. However, these digital forensics tools are often difficult to use, usually task specific, and generally require professionally trained users with IT backgrounds. The relevant tools are also often open source requiring additional technical knowledge and proper configuration. This makes it difficult for investigators without some computer science background to easily conduct the needed disk analysis. In this paper, we present AUDIT, a novel automated disk investigation toolkit that supports investigations conducted by non-expert (in IT and disk technology and expert investigators. Our proof of concept design and implementation of AUDIT intelligently integrates open source tools and guides non-IT professionals while requiring minimal technical knowledge about the disk structures and file systems of the target disk image.

  13. Ringed accretion disks: equilibrium configurations

    CERN Document Server

    Pugliese, D

    2015-01-01

    We investigate a model of ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the General Relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can be then determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We pr...

  14. IBM 3390 Hard Disk Platter

    CERN Multimedia

    1991-01-01

    The 3390 disks rotated faster than those in the previous model 3380. Faster disk rotation reduced rotational delay (ie. the time required for the correct area of the disk surface to move to the point where data could be read or written). In the 3390's initial models, the average rotational delay was reduced to 7.1 milliseconds from 8.3 milliseconds for the 3380 family.

  15. Disks and Outflows

    Science.gov (United States)

    Rodriguez, L. F.

    2002-05-01

    The presence of disks and outflows characterizes the earliest stages of stellar evolution. I will review recent results that exemplify how the radio observations have become powerful tools in the study of these extremely young objects. Binarity and multiplicity seem to be factors that we are only starting to understand. Outflows are now seen as laboratories for the chemistry of shocked regions. Finally, the efforts to extend the paradigm for low-mass stellar formation to more massive protostars can be tested critically in the radio wavelengths. I acknowledge the support from CONACyT, Mexico.

  16. Are degenerative rotator cuff disorders a cause of shoulder pain? Comparison of prevalence of degenerative rotator cuff disease to prevalence of nontraumatic shoulder pain through three systematic and critical reviews.

    Science.gov (United States)

    Vincent, Karl; Leboeuf-Yde, Charlotte; Gagey, Olivier

    2017-05-01

    The role of degeneration is not well understood for rotator cuff pain. If age-related degenerative changes would be the cause of symptoms, degeneration would precede or concur with self-reported pain. We performed 3 systematic literature reviews. Our objectives were to determine the prevalence estimates for rotator cuff partial or complete tears (1) in cadavers and (2) in the general population and (3) to estimate the incidence/prevalence of self-reported nontraumatic shoulder pain in the general population in order to compare their respective age-related profiles. We searched PubMed and ScienceDirect, including 2015, for cadaveric studies and transverse and longitudinal studies of the general population reporting the incidence/prevalence of rotator cuff disorders or nontraumatic shoulder pain, or both, according to age. The review process followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Results were interpreted visually. We found 6 cadaveric studies, 2 studies from the general population reporting complete tears, and 10 articles on nontraumatic shoulder pain in the general population that met our criteria. The profiles of degeneration vs. pain were very similar in early years. Although degenerative rotators cuff lesions increased gradually after 50 years, the incidence/prevalence of nontraumatic shoulder pain decreased after 65 years. The profile of age-related degenerative rotator cuff disorders fails to correlate systematically with self-reported nontraumatic shoulder pain, particularly in older age; thus, it appears that degeneration should not be considered the primary source of the pain. Physical activity may play an important role in the production of the pain, a theory that warrants further study. Copyright © 2017. Published by Elsevier Inc.

  17. The Formation of Galactic Disks

    CERN Document Server

    Mo, H J; White, S D M; Mao, Shude; White, Simon D.M.

    1997-01-01

    We study the population of galactic disks expected in current hierarchical clustering models for structure formation. A rotationally supported disk with exponential surface density profile is assumed to form with a mass and angular momentum which are fixed fractions of those of its surrounding dark halo. We assume that haloes respond adiabatically to disk formation, and that only stable disks can correspond to real systems. With these assumptions the predicted population can match both present-day disks and the damped Lyman alpha absorbers in QSO spectra. Good agreement is found provided: (i) the masses of disks are a few percent of those of their haloes; (ii) the specific angular momenta of disks are similar to those of their haloes; (iii) present-day disks were assembled recently (at z3kpc/h and about 10% at r>10kpc/h. The cross-section for absorption is strongly weighted towards disks with large angular momentum and so large size for their mass. The galaxy population associated with damped absorbers should...

  18. Disk storage at CERN

    CERN Document Server

    Mascetti, L; Chan, B; Espinal, X; Fiorot, A; Labrador, H Gonz; Iven, J; Lamanna, M; Presti, G Lo; Mościcki, JT; Peters, AJ; Ponce, S; Rousseau, H; van der Ster, D

    2015-01-01

    CERN IT DSS operates the main storage resources for data taking and physics analysis mainly via three system: AFS, CASTOR and EOS. The total usable space available on disk for users is about 100 PB (with relative ratios 1:20:120). EOS actively uses the two CERN Tier0 centres (Meyrin and Wigner) with 50:50 ratio. IT DSS also provide sizeable on-demand resources for IT services most notably OpenStack and NFS-based clients: this is provided by a Ceph infrastructure (3 PB) and few proprietary servers (NetApp). We will describe our operational experience and recent changes to these systems with special emphasis to the present usages for LHC data taking, the convergence to commodity hardware (nodes with 200-TB each with optional SSD) shared across all services. We also describe our experience in coupling commodity and home-grown solution (e.g. CERNBox integration in EOS, Ceph disk pools for AFS, CASTOR and NFS) and finally the future evolution of these systems for WLCG and beyond.

  19. Disk storage at CERN

    Science.gov (United States)

    Mascetti, L.; Cano, E.; Chan, B.; Espinal, X.; Fiorot, A.; González Labrador, H.; Iven, J.; Lamanna, M.; Lo Presti, G.; Mościcki, JT; Peters, AJ; Ponce, S.; Rousseau, H.; van der Ster, D.

    2015-12-01

    CERN IT DSS operates the main storage resources for data taking and physics analysis mainly via three system: AFS, CASTOR and EOS. The total usable space available on disk for users is about 100 PB (with relative ratios 1:20:120). EOS actively uses the two CERN Tier0 centres (Meyrin and Wigner) with 50:50 ratio. IT DSS also provide sizeable on-demand resources for IT services most notably OpenStack and NFS-based clients: this is provided by a Ceph infrastructure (3 PB) and few proprietary servers (NetApp). We will describe our operational experience and recent changes to these systems with special emphasis to the present usages for LHC data taking, the convergence to commodity hardware (nodes with 200-TB each with optional SSD) shared across all services. We also describe our experience in coupling commodity and home-grown solution (e.g. CERNBox integration in EOS, Ceph disk pools for AFS, CASTOR and NFS) and finally the future evolution of these systems for WLCG and beyond.

  20. Dynamic stabilization for degenerative spondylolisthesis and lumbar spinal instability.

    Science.gov (United States)

    Ohtonari, Tatsuya; Nishihara, Nobuharu; Suwa, Katsuyasu; Ota, Taisei; Koyama, Tsunemaro

    2014-01-01

    Lumbar interbody fusion is a widely accepted surgical procedure for patients with lumbar degenerative spondylolisthesis and lumbar spinal instability in the active age group. However, in elderly patients, it is often questionable whether it is truly necessary to construct rigid fixation for a short period of time. In recent years, we have been occasionally performing posterior dynamic stabilization in elderly patients with such lumbar disorders. Posterior dynamic stabilization was performed in 12 patients (6 women, 70.9 ± 5.6 years old at the time of operation) with lumbar degenerative spondylolisthesis in whom % slip was less than 20% or instability associated with lumbar disc herniation between March 2011 and March 2013. Movement occurs through the connector linked to the pedicle screw. In practice, 9 pairs of D connector system where the rod moves in the perpendicular direction alone and 8 pairs of Dynamic connector system where the connector linked to the pedicle screw rotates in the sagittal direction were installed. The observation period was 77-479 days, and the mean recovery rate of lumbar Japanese Orthopedic Association (JOA) score was 65.6 ± 20.8%. There was progression of slippage due to slight loosening in a case with lumbar degenerative spondylolisthesis, but this did not lead to exacerbation of the symptoms. Although follow-up was short, there were no symptomatic adjacent vertebral and disc disorders during this period. Posterior dynamic stabilization may diminish the development of adjacent vertebral or disc disorders due to lumbar interbody fusion, especially in elderly patients, and it may be a useful procedure that facilitates decompression and ensures a certain degree of spinal stabilization.

  1. Degenerative spondylolisthesis: contemporary review of the role of interbody fusion.

    Science.gov (United States)

    Baker, Joseph F; Errico, Thomas J; Kim, Yong; Razi, Afshin

    2017-02-01

    Degenerative spondylolisthesis is a common presentation, yet the best surgical treatment continues to be a matter of debate. Interbody fusion is one of a number of options, but its exact role remains ill defined. The aim of this study was to provide a contemporary review of the literature to help determine the role, if any, of interbody fusion in the surgical treatment of degenerative spondylolisthesis. A systematic review of the literature since 2005 was performed. Details on study size, patient age, surgical treatments, levels of slip, patient reported outcome measures, radiographic outcomes, complications and selected utility measures were recorded. Studies that compared a cohort treated with interbody fusion and at least one other surgical intervention for comparison were included for review. Only studies examining the effect in degenerative spondylolisthesis were included. Two authors independently reviewed the manuscripts and extracted key data. Thirteen studies were included in the final analysis. A total of 565 underwent interbody fusion and 761 underwent other procedures including decompression alone, interspinous stabilisation and posterolateral fusion with or without instrumentation. Most studies were graded Level III evidence. Heterogeneous reporting of outcomes prevented formal statistical analysis. However, in general, studies reviewed concluded no significant clinical or radiographic difference in outcome between interbody fusion and other treatments. Two small studies suggested interbody fusion is a better option in cases of definite instability. Interbody fusion only provided outcomes as good as instrumented posterolateral fusion. However, most studies were Level III, and hence, we remain limited in defining the exact role of interbody fusion-cases with clear instability appear to be most appropriate. Future work should use agreed-upon common outcome measures and definitions.

  2. Development of Modulators Against Degenerative Aging Using Radiation Fusion Technology

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Sung Kee; Jung, U.; Park, H. R.

    2010-04-15

    In this study, we selected final 20 biomarkers for the degenerative aging to develop radiation aging modeling, and validated a few of selected markers to utilize them in the screening of aging modulators. To select the biomarkers of the degenerative aging, 4 categories of aging-related markers (immune/hematopoiesis, oxidative damage, signaling molecule, lipid metabolism) were comparatively analyzed in irradiated and normally aged biosystems (cell lines or mice). In result, most of the biomarkers showed similar changes by irradiation and normal aging. Regarding the immune/hematopoiesis, the decline of immune cell functions (lymphocyte, NK cell) and Th1/Th2 imbalance, and decreased antigen-presenting of dendritic cells were observed and 10 biomarkers were selected in this category. mtDNA deletion was selected for the oxidative damage marker, 6 biomarkers including p21 and p-FOXO3a for signaling molecule biomarkers, and 3 biomarkers including the adipose tissue weight were selected for lipid metabolism. In addition, the various radiation application conditions by single/factionated irradiation and the periods after the irradiation were investigated for the optimal induction of changes of biomarker, which revealed that total 5Gy of 10 or more fractionated irradiations and 4 months or greather period were observed to be optimal. To found the basis for the screening of natural aging modulators, some selected aging biomarkers were validated by their inhibition by well-known natural agents (EGCG, HemoHIM, etc) in aged cell or mouse model. Additionally, by evaluating the reductive efficacy of 5 natural agents on the degeneration of skin and reproductive organs induced by radiation and chemicals (cyclophosphamide, etc), we established the base for the screening of degenerative diseases by various factors

  3. Mesenchymal Stem Cell Secretome: A Potential Tool for the Prevention of Muscle Degenerative Changes Associated With Chronic Rotator Cuff Tears.

    Science.gov (United States)

    Sevivas, Nuno; Teixeira, Fábio Gabriel; Portugal, Raquel; Araújo, Luís; Carriço, Luís Filipe; Ferreira, Nuno; Vieira da Silva, Manuel; Espregueira-Mendes, João; Anjo, Sandra; Manadas, Bruno; Sousa, Nuno; Salgado, António J

    2016-08-08

    Massive rotator cuff tears (MRCTs) are usually chronic lesions with pronounced degenerative changes, where advanced fatty degeneration and atrophy can make the tear irreparable. Human mesenchymal stem cells (hMSCs) secrete a range of growth factors and vesicular systems, known as secretome, that mediates regenerative processes in tissues undergoing degeneration. To study the effect of hMSC secretome on muscular degenerative changes and shoulder function on a rat MRCT model. Controlled laboratory study. A bilateral 2-tendon (supraspinatus and infraspinatus) section was performed to create an MRCT in a rat model. Forty-four Wistar-Han rats were randomly assigned to 6 groups: control group (sham surgery), lesion control group (MRCT), and 4 treated-lesion groups according to the site and periodicity of hMSC secretome injection: single local injection, multiple local injections, single systemic injection, and multiple systemic injections. Forelimb function was analyzed with the staircase test. Atrophy and fatty degeneration of the muscle were evaluated at 8 and 16 weeks after injury. A proteomic analysis was conducted to identify the molecules present in the hMSC secretome that can be associated with muscular degeneration prevention. When untreated for 8 weeks, the MRCT rats exhibited a significantly higher fat content (0.73% ± 0.19%) compared with rats treated with a single local injection (0.21% ± 0.04%; P muscle atrophy, 8 weeks after injury, only the single local injection group (0.0993% ± 0.0036%) presented a significantly higher muscle mass than that of the untreated MRCT group (0.0794% ± 0.0047%; P muscle regeneration, namely, pigment epithelium-derived factor and follistatin. The study data suggest that hMSC secretome effectively decreases the fatty degeneration and atrophy of the rotator cuff muscles. We describe a new approach for decreasing the characteristic muscle degeneration associated with chronic rotator cuff tears. This strategy is particularly

  4. TRACTION-EXTENDED THERAPY OF PATIENTS WITH LUMBAR DEGENERATIVE DISEASE

    OpenAIRE

    V. A. Zhirnov; D. P. Krest'yanov; A. K. Vasil'kin

    2013-01-01

    Based on the survey of 148 patients with an lumbar degenerative disease, there have been studied immediate and medium-term results of the comprehensive conservative treatment of the patients with and without application of traction exposure on the spine. It was found out that the traction of the spine leads to a quicker and more durable relief of symptoms in comparison with the control groups where traction therapy wasn't carried out. Application of the traction-extended therapy in three plan...

  5. Revisiting the Term Neuroprotection in Chronic and Degenerative Diseases

    Science.gov (United States)

    Orsini, Marco; Nascimento, Osvaldo J.M.; Matta, Andre P.C.; Reis, Carlos Henrique Melo; de Souza, Olivia Gameiro; Bastos, Victor Hugo; Moreira, Rayele; Ribeiro, Pedro; Fiorelli, Stenio; Novellino, Pietro; Pessoa, Bruno; Cunha, Mariana; Pupe, Camila; Morales, Pedro S.; Filho, Pedro F. Moreira; Trajano, Eduardo Lima; Oliveira, Acary Bulle

    2016-01-01

    Thanks to the development of several new researches, the lifetime presented a significant increase, even so, we still have many obstacles to overcome – among them, manage and get responses regarding neurodegenerative diseases. Where we are in the understanding of neuroprotection? Do we really have protective therapies for diseases considered degeneratives such as amyotrophic lateral sclerosis and its variants, Parkinson’s disease, Alzheimer’s disease and many others? Neuroprotection is defined by many researches as interactions and interventions that can slow down or even inhibit the progression of neuronal degeneration process. We make some considerations on this neuroprotective effect. PMID:27127599

  6. Plantar fasciitis: a degenerative process (fasciosis) without inflammation.

    Science.gov (United States)

    Lemont, Harvey; Ammirati, Krista M; Usen, Nsima

    2003-01-01

    The authors review histologic findings from 50 cases of heel spur surgery for chronic plantar fasciitis. Findings include myxoid degeneration with fragmentation and degeneration of the plantar fascia and bone marrow vascular ectasia. Histologic findings are presented to support the thesis that "plantar fasciitis" is a degenerative fasciosis without inflammation, not a fasciitis. These findings suggest that treatment regimens such as serial corticosteroid injections into the plantar fascia should be reevaluated in the absence of inflammation and in light of their potential to induce plantar fascial rupture.

  7. Imaging of extradural spinal lesions; Bildgebung extraduraler Raumforderungen

    Energy Technology Data Exchange (ETDEWEB)

    Ahlhelm, F.; Schulte-Altedorneburg, G.; Naumann, N.; Reith, W. (Universitaetsklinikum des Saarlandes, Klinik fuer Diagnostische und Interventionelle Neuroradiologie, Homburg/Saar); Nabhan, A. (Universitaetsklinikum des Saarlandes, Homburg/Saar, Klinik fuer Allgemeine und Spezielle Neurochirurgie)

    2006-12-15

    There is a wide variety of spinal extradural tumors. In addition to real neoplasms, degenerative diseases, congenital abnormalities and inflammatory disorders can be causes of extradural masses. Due to the bony boundary of the spinal canal, both benign as well as malignant masses can cause progressive neurological deficits including paraplegia. Most of the spinal tumors are benign (hemangioma of the vertebral body, degenerative diseases). In younger patients congenital abnormalities and primary tumors of the spine have to be considered, whereas in adults the list of differential diagnoses should include secondary malignancies such as metastases and lymphomas as well as metabolic disorders such as osteoporotic vertebral compression fracture and Paget's disease. Cross-sectional imaging techniques such as magnetic resonance imaging (MRI) and computed tomography (CT) of the spine often help to make a specific diagnosis of extradural spinal lesions and represent important tools for tumor staging and preoperative evaluation. (orig.) Das Spektrum der spinalen extraduralen Tumoren ist sehr gross. Neben echten Neoplasien koennen auch degenerative Veraenderungen und Anlagestoerungen sowie entzuendliche Veraenderungen Ursachen einer extraduralen Raumforderung sein. Aufgrund der knoechernen Begrenzung des Spinalkanals koennen neben Malignomen auch benigne Tumoren und degenerative spinale Veraenderungen zu progredienten neurologischen Ausfallsymptomen (einschliesslich Querschnittsymptomatik) fuehren. Die ueberwiegende Mehrzahl der extraduralen Raumforderungen der Wirbelsaeule ist benigne (Haemangiom des Wirbelkoerpers, degenerative Erkrankungen). Bei jungen Patienten sind Anlagestoerungen und primaere Wirbelsaeulentumoren zu beruecksichtigen, wogegen beim Erwachsenen an sekundaere Malignome, wie Metastasen und Lymphome sowie eine metabolische Erkrankung, wie die osteoporotische Wirbelkoerpersinterungsfraktur oder der Morbus Paget, differenzialdiagnostisch gedacht werden

  8. Chemistry in evolving protoplanetary disks

    NARCIS (Netherlands)

    Jonkheid, Bastiaan Johan

    2006-01-01

    Planets form in disks of gas and dust around young stars. Since the gas makes up 99 % of the disk mass, it is critical for our understanding of planet formation to gain direct information from the gas, independently of what can be learned from dust emission. In this thesis, calculations are presente

  9. RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

    2015-12-15

    We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

  10. Friction characteristics of floppy disks

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This note presents the principle and structure of a tribological measure for floppy disks.The precision of the force measuring system is 1 mN in loading and 3×10-6 N in friction.The resolution of the film thickness between head and floppy disk is 0.5 nm in the vertical and 1.5 nm in the horizontal direction.In order to investigate the tribological characteristics of floppy disks,six types of floppy disks have been tested and the floating properties of these disks are also studied with film measuring system.The experimental results of the surface morphology and friction coefficient of these floppy disks using the atomic force microscope/friction force mcroscope (AFM/FFM) are in accordance with the conclusion made by our own measuring system.The experimental results show that the air film thickness between head and disk is of the same order as the surface roughness of floppy disks.

  11. Melting of polydisperse hard disks

    NARCIS (Netherlands)

    Pronk, S.; Frenkel, D.

    2004-01-01

    The melting of a polydisperse hard-disk system is investigated by Monte Carlo simulations in the semigrand canonical ensemble. This is done in the context of possible continuous melting by a dislocation-unbinding mechanism, as an extension of the two-dimensional hard-disk melting problem. We find

  12. Melting of polydisperse hard disks

    NARCIS (Netherlands)

    Pronk, S.; Frenkel, D.

    2004-01-01

    The melting of a polydisperse hard-disk system is investigated by Monte Carlo simulations in the semigrand canonical ensemble. This is done in the context of possible continuous melting by a dislocation-unbinding mechanism, as an extension of the two-dimensional hard-disk melting problem. We find th

  13. Vascular, hepatic and renal lesions by Dirofilaria immitis invasion in dogs

    Directory of Open Access Journals (Sweden)

    S.A. Pasca

    2012-08-01

    Full Text Available Morphological investigations were conducted on four bodies of dogs who died due to severe clinical symptoms following a massive invasion of cardiac and pulmonary Dirofilaria. The subjects were monitored clinically and diagnosed serologically positive for the Heartworm disease. The necropsy examination of the cardiovascular system (right ventricle and pulmonary artery revealed the presence of 25 adult parasites in one dog with length ranging between 8 and 33cm. Macroscopically, lesions consistently observed were represented by the right ventricular dilatation and the diffuse wall thickening of the pulmonary artery. Parasitic invasion secondary lesions were present in the lungs, liver and kidneys (cardiac and vascular lesions. The histological examination mainly revealed myocardial injury, vascular (dystrophic, pulmonary (circulatory and inflammatory, hepatic (degenerative and renal (degenerative and inflammatory damage.

  14. Physical processes in protoplanetary disks

    CERN Document Server

    Armitage, Philip J

    2015-01-01

    This review introduces physical processes in protoplanetary disks relevant to accretion and the initial stages of planet formation. After reprising the elementary theory of disk structure and evolution, I discuss the gas-phase physics of angular momentum transport through turbulence and disk winds, and how this may be related to episodic accretion observed in Young Stellar Objects. Turning to solids, I review the evolution of single particles under aerodynamic forces, and describe the conditions necessary for the development of collective gas-particle instabilities. Observations show that disks are not always radially smooth axisymmetric structures, and I discuss how gas and particle processes can interact to form observable large-scale structure (at ice lines, vortices and in zonal flows). I conclude with disk dispersal.

  15. Detection of precessing circumpulsar disks

    CERN Document Server

    Grimani, C

    2014-01-01

    Experimental evidences indicate that formations of disks and planetary systems around pulsars are allowed. Unfortunately, direct detections through electromagnetic observations appear to be quite rare. In the case of PSR 1931+24, the hypothesis of a rigid precessing disk penetrating the pulsar light cylinder is found consistent with radio transient observations from this star. Disk self-occultation and precession may limit electromagnetic observations. Conversely, we show here that gravitational waves generated by disk precessing near the light cylinder of young and middle aged pulsars would be detected by future space interferometers with sensitivities like those expected for DECIGO (DECI-hertz Interferometer Gravitational Wave Observatory) and BBO (Big Bang Observer). The characteristics of circumpulsar detectable precessing disks are estimated as a function of distance from the Solar System. Speculations on upper limits to detection rates are presented.

  16. A Disk Scheduling Algorithm: SPFF

    Institute of Scientific and Technical Information of China (English)

    HU Ming

    2005-01-01

    We put forward an optimal disk schedule with n disk requests and prove its optimality mathematically. Generalizing the idea of an optimal disk schedule, we remove the limit of n requests and, at the same time, consider the dynamically arrival model of disk requests to obtain an algorithm, shortest path first-fit first (SPFF). This algorithm is based on the shortest path of disk head motion constructed by all the pendent requests. From view of the head-moving distance, it has the stronger globality than SSTF. From view of the head-moving direction, it has the better flexibility than SCAN. Therefore, SPFF keeps the advantage of SCAN and, at the same time, absorbs the strength of SSTF. The algorithm SPFF not only shows the more superiority than other scheduling polices, but also have higher adjustability to meet the computer system's different demands.

  17. The influence of changes in cervical lordosis on bulging disk and spinal stenosis: functional MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Joon; Eun, Choong Ki [Pusan Paik Hospital, Inje Univ. College of Medicine, Pusan (Korea, Republic of)

    2001-05-01

    To assess the effect of lordotic curve change of the cervical spine on disk bulging and spinal stenosis by means of functional cervical MR imaging at the flexion and extension position. Using a 1.5T imager, kinematic MR examinations of 25 patients with degenerative spondylosis (average age, 41 years) were performed at the neutral, flexed and extended position of the cervical spine. Sagittal T2-weighted turbo spin-echo images were obtained during each of the three phases. Lordotic angle, bulging thickness of the disk, AP diameter of the spinal canal, and distance between the disk and spinal cord were measured on the workstation at each disk level. After qualitative independent observation of disk bulging, one of four grades(0, normal; 1, mild; 2, moderate; 3, marked) was assigned at each phase, and after further comparative observation, one of five scores (-2, prominent decrease; -1, mild decrease; 0, no change; 1, notable increase; 2 prominent increase) was also assigned. In addition, bulging thickness of the disk was measured and compared at the neutral, flexed, and extended positions. Average angles of the cervical spine were 160.5{+-}5.9 deg (neutral position, lordotic angle); 185.4{+-}8.5 deg (flexion, kyphotic angle); and 143.7{+-}6.7 deg (extension, lordotic angle). Average grades of disk bulging were 0.55 at the neutral position. 0.16 at flexion, and 0.7 at extension. Comparative observation showed that average scores of disk bulging were -0.39 at flexion and 0.31 at extension. The bulging thickness of the disk decreased by 24.2% at flexion and increased by 30.3% at extension, while the diameter of the spinal canal increased by 4.5% at flexion and decreased by 3.6% at extension. The distance from the posterior margin of the disk to the anterior margin of the spinal cord decreased at both flexion(6.6%) and extension(19.1%). Functional MRI showed that compared with the neutral position, disk bulging and spinal stenosis are less prominent at flexion and

  18. Dynamic of Grassland Biomass in Different Degenerative Stages

    Institute of Scientific and Technical Information of China (English)

    YAN Yan; LIU Shuzhen; ZHOU Wei

    2006-01-01

    The dynamics of plant community and above- and belowground biomass of the different degenerative stages was researched of Kobresia humlis meadows of Nakchu prefecture in Tibet Autonomous Region. The results indicated that the aggravation of the degree of deterioration of alpine meadow is, the lower the vegetation coverage, percentage of excellent forage, and biodiversity are. The total aboveground biomass is highest in the lightly degraded stages while it is lowest in the extremely degraded stages. With the aggravation of degradation, the aboveground biomass of forbs increases while that of Cyperaceae decreases. We found that the belowground biomass was mostly distributed in the 0-10 cm soil depth in the alpine meadow with a "T"-shape distribution feature, and with the acceleration of deterioration, the numbers of roots becomes less and less. Meanwhile, the above- and belowground biomass of the different degraded communities was significantly correlated(r=0.963). There is an obvious positive correlation with the above- and belowground biomass in different degenerative stages, and their ratio increased with the aggravation of degradation.

  19. Degenerative Suspensory Ligament Desmitis – A New Reality

    Directory of Open Access Journals (Sweden)

    Jaroslava Halper*, Ahrar Khan1 and P. O. Eric Mueller2

    2011-01-01

    Full Text Available Degenerative suspensory ligament desmitis (DSLD is a chronic, debilitating disease occurring primarily in Peruvian Pasos and Peruvian Paso crosses. However, many other breeds are afflicted as well. DSLD is characterized by a slowly progressing bilateral or quadrilateral lameness. Typically, the owner does not recall any trauma or performance related injury. Fetlock effusion, static and dynamic hyperextension and degenerative joint disease are hallmarks on physical examination. Ultrasonography of affected ligaments reveals diffuse loss of echogenicity, and an irregular fiber pattern. Though until recently DSLD was considered a collagen disorder strictly limited to suspensory ligaments (SLs, our data show that it is a systemic disease involving tissues with high content of collagen. We have identified abnormal accumulations of proteoglycans not only in the SLs, but also in the superficial and deep digital flexor tendons, patellar and nuchal ligaments, aorta, coronary arteries and sclerae of DSLD-affected horses. Our most recent data point to the presence of an abnormal form of decorin in these proteoglycan deposits. This decorin also exhibited altered biological activity. Treatment for DSLD-affected horses is empirical and directed at minimizing musculoskeletal pain and providing support for the suspensory apparatus. Restricted exercise, supportive bandages and nonsteroidal anti-inflammatory drugs provide some, but usually only temporary relief. Unfortunately, unrelenting pain, severe lameness and suffering require all too often humane euthanasia.

  20. Long term results of radiotherapy of degenerative joint diseases

    Energy Technology Data Exchange (ETDEWEB)

    Lindner, H.; Freislederer, R.

    1982-04-01

    At the Radiologic Department of the Staedt. Krankenhaus Passau, 473 patients with degenerative diseases in the big joints and the spine were irradiated with the caesium unit between 1971 and 1979. Among these patients, 249 could be followed up during a prolonged period (1/2 to 9 years, i.e. 4.2 years on an average). According to the categories of v. Pannewitz, 11% were pain-free at this moment, 21% showed an essential improvement, 29% showed an improvement, and 39% were not influenced by the treatment. 13.5% showed recurrent pains; these were mentioned as 'not influenced' in the statistical analysis. It is proved that the relief of pain does not depend on the age of the patients, but on the anamnesis period, the results of the X-ray examiantion, and the degree of the restriction of mobility. Due to the delay of irradiation, a preliminary treatment mostly produces a less favorable radiotherapeutic result. Compared with other therapeutic methods, the long term results of radiotherapy of degenerative joint diseases are generally favorable. This conclusion is also confirmed by the results of patients checked up more than five years after the treatment.

  1. Flexible Stabilisation of the Degenerative Lumbar Spine Using PEEK Rods

    Directory of Open Access Journals (Sweden)

    Jacques Benezech

    2016-01-01

    Full Text Available Posterior lumbar interbody fusion using cages, titanium rods, and pedicle screws is considered today as the gold standard of surgical treatment of lumbar degenerative disease and has produced satisfying long-term fusion rates. However this rigid material could change the physiological distribution of load at the instrumental and adjacent segments, a main cause of implant failure and adjacent segment disease, responsible for a high rate of further surgery in the following years. More recently, semirigid instrumentation systems using rods made of polyetheretherketone (PEEK have been introduced. This clinical study of 21 patients focuses on the clinical and radiological outcomes of patients with lumbar degenerative disease treated with Initial VEOS PEEK®-Optima system (Innov’Spine, France composed of rods made from PEEK-OPTIMA® polymer (Invibio Biomaterial Solutions, UK without arthrodesis. With an average follow-up of 2 years and half, the chances of reoperation were significantly reduced (4.8%, quality of life was improved (ODI = 16%, and the adjacent disc was preserved in more than 70% of cases. Based on these results, combined with the biomechanical and clinical data already published, PEEK rods systems can be considered as a safe and effective alternative solution to rigid ones.

  2. Raptor Acupuncture for Treating Chronic Degenerative Joint Disease

    Directory of Open Access Journals (Sweden)

    Keum Hwa Choi

    2016-12-01

    Full Text Available A permanently captive 21-year-old male bald eagle was diagnosed with chronic degenerative joint disease in the right stifle with severe lameness (Grade 5 based on radiography. Clinical signs included decreased movement, vocalization, non weight-bearing on the affected limb, inappetence, depression, and pododermatitis on the left foot (bumblefoot, Grade 3. The eagle was treated with anti-inflammatory or analgesic drugs including carprofen and celecoxib. As there was no observed clinical improvement with any of the treatments, acupuncture treatment was provided. The eagle was treated with dry needle acupuncture once per week for 2 months and biweekly for another 2 months. The Traditional Eastern Medicine diagnosis of this eagle was Bony Bi syndrome. The selected acupuncture points were ST 36, LI 4, BL 40, BL 60, GB 34, and Ba Feng (Table 3. The lameness score improved from Grade 5 to Grade 1 after 4 months of acupuncture treatment. The observed pododermatitis improved from Grade 3 to Grade 0. Symptoms including inappetence and vocalizations were significantly reduced over the 4 month period. There was no significant improvement in the radiographic signs. In conclusion, acupuncture may be a potential medical option for permanently captive raptors having musculoskeletal conditions, such as degenerative joint disease.

  3. Raptor Acupuncture for Treating Chronic Degenerative Joint Disease.

    Science.gov (United States)

    Choi, Keum Hwa; Buhl, Gail; Ponder, Julia

    2016-12-01

    A permanently captive 21-year-old male bald eagle was diagnosed with chronic degenerative joint disease in the right stifle with severe lameness (Grade 5) based on radiography. Clinical signs included decreased movement, vocalization, non weight-bearing on the affected limb, inappetence, depression, and pododermatitis on the left foot (bumblefoot, Grade 3). The eagle was treated with anti-inflammatory or analgesic drugs including carprofen and celecoxib. As there was no observed clinical improvement with any of the treatments, acupuncture treatment was provided. The eagle was treated with dry needle acupuncture once per week for 2 months and biweekly for another 2 months. The Traditional Eastern Medicine diagnosis of this eagle was Bony Bi syndrome. The selected acupuncture points were ST 36, LI 4, BL 40, BL 60, GB 34, and Ba Feng (Table 3). The lameness score improved from Grade 5 to Grade 1 after 4 months of acupuncture treatment. The observed pododermatitis improved from Grade 3 to Grade 0. Symptoms including inappetence and vocalizations were significantly reduced over the 4 month period. There was no significant improvement in the radiographic signs. In conclusion, acupuncture may be a potential medical option for permanently captive raptors having musculoskeletal conditions, such as degenerative joint disease. Copyright © 2016. Published by Elsevier B.V.

  4. Ranibizumab for the treatment of degenerative ocular conditions

    Directory of Open Access Journals (Sweden)

    Triantafylla M

    2014-06-01

    Full Text Available Magdalini Triantafylla,1 Horace F Massa,2 Doukas Dardabounis,1 Zisis Gatzioufas,2 Vassilios Kozobolis,1 Konstantinos Ioannakis,1 Irfan Perente,1,3 Georgios D Panos1,21Department of Ophthalmology, University General Hospital of Alexandroupolis, School of Medicine, University of Thrace, Alexandroupolis, Greece; 2Department of Ophthalmology, Geneva University Hospitals, Faculty of Medicine, University of Geneva, Switzerland; 3Beyoglou Eye Research and Teaching Hospital, Istanbul University, Istanbul, TurkeyAbstract: Degenerative ocular conditions, such as age-related macular degeneration, diabetic retinopathy, retinal vein occlusions, and myopic degeneration, have become a major public health problem and a leading cause of blindness in developed countries. Anti-vascular endothelial growth factor (VEGF drugs seem to be an effective and safe treatment for these conditions. Ranibizumab, a humanized monoclonal antibody antigen-binding fragment, which inhibits all biologically active isoforms of VEGF-A, is still the gold standard treatment for the majority of these pathological entities. In this review, we present the results of the most important clinical trials concerning the efficacy and safety of ranibizumab for the treatment of degenerative ocular conditions.Keywords: age-related macular degeneration, diabetic macular edema, retinal vein occlusion, anti-VEGF, safety, efficacy, quality of life

  5. Numerical Investigation of Circumplanetary Disks

    Science.gov (United States)

    Mitchell, Tyler R.; Stewart, G. R.

    2012-10-01

    The regular satellites of Jupiter and Saturn are believed to have formed in circumplanetary disks that were present during the late stages of giant planet formation. At present, there is a large amount of uncertainly in both the structure of these disks and the nature of angular momentum transport within them. In circumstellar disks, magnetorotational rotational instability (MRI) is generally invoked as a mechanism to transfer angular momentum and drive accretion. It is unclear whether circumplanetary disks are sufficiently ionized for the MRI to be active. In an effort to better understand the physical nature of circumplanetary disks, we present 1+1D numerical models of Jovian and Saturnian circumplanetary disks. Our models include viscous diffusion, infall from the solar nebula and external photoevaporation. The combination of these three processes allow for steady-state, truncated disks roughly consistent with the present state of the regular satellite systems of Jupiter and Saturn (Mitchell & Stewart, 2011). Unlike recent models of tidal truncation (Martin & Lubow, 2010), our initial models showed that photoevaporation is able to truncate circumplanetary disks to a small fraction of the Hill radius. One goal of this work is to verify our previous results and confirm that truncated disks can be formed using models with more realistic viscous processes. In order to simplify the problem, our initial models employed a viscosity that was linearly dependent on radius. Our current disk models use a viscosity that is calculated locally based on the midplane temperature that is determined from detailed vertical structure calculations. These models are used to conduct an initial investigation of the viability of an active MRI as well as baroclinic instability and other instabilities that may exist.

  6. Evolution of magnetized protoplanetary disks

    Science.gov (United States)

    Reyes-Ruiz, Mauricio; Stepinski, Tomasz F.

    1995-01-01

    We investigate the global evolution of a turbulent protoplanetary disk in its viscous stage, incorporating the effects of Maxwell stress due to a large-scale magnetic field permeating disk. We assume that the viscous stress is given by an alpha model. A magnetic field is produced contemporaneously by an alpha omega dynamo mechanism and the resultant Maxwell stress assists the viscous stress in providing the means for disk evolution. The aim of this work is to compare the evolution of magnetized and nonmagnetized disks driven by turbulent viscosity of the same magnitude and thus assess the effects of a self-generated magnetic field on the structure and dynamical evolution of protoplanetary disks. Two illustrative examples corresponding to two different initial conditions are considered: a high-mass case that starts with a disk of 0.245 solar mass and angular momentum of 5.6 x 10(exp 52)g sq cm/s, and a low-mass that case starts with a disk of 0.11 solar mass and angular momentum of 1.8 x 10(exp 52)g sq cm/s. For each of these two cases the radial development of a disk is calculated numerically assuming a fiducial value of the dimensionless viscosity parameter alpha(sub ss) = 0.01, as well as alpha(sub ss) = 2 x 10(exp -3). In all cases the central star has a mass equal to 1 solar mass. The most striking feature of magnetized disk evolution is the presence of the surface density bulge located in the region of the disk where the dynamo mechanism cannot support a magnetic field. The bulge persists for a time of the order of 10(exp 5)-10(exp 6) yr. The presence and persistence of the surface density bulge may have important implications for the process of planet formation and the overall characteristics of resultant planetary systems.

  7. Stochastic disks that roll

    Science.gov (United States)

    Holmes-Cerfon, Miranda

    2016-11-01

    We study a model of rolling particles subject to stochastic fluctuations, which may be relevant in systems of nano- or microscale particles where rolling is an approximation for strong static friction. We consider the simplest possible nontrivial system: a linear polymer of three disks constrained to remain in contact and immersed in an equilibrium heat bath so the internal angle of the polymer changes due to stochastic fluctuations. We compare two cases: one where the disks can slide relative to each other and the other where they are constrained to roll, like gears. Starting from the Langevin equations with arbitrary linear velocity constraints, we use formal homogenization theory to derive the overdamped equations that describe the process in configuration space only. The resulting dynamics have the formal structure of a Brownian motion on a Riemannian or sub-Riemannian manifold, depending on if the velocity constraints are holonomic or nonholonomic. We use this to compute the trimer's equilibrium distribution with and without the rolling constraints. Surprisingly, the two distributions are different. We suggest two possible interpretations of this result: either (i) dry friction (or other dissipative, nonequilibrium forces) changes basic thermodynamic quantities like the free energy of a system, a statement that could be tested experimentally, or (ii) as a lesson in modeling rolling or friction more generally as a velocity constraint when stochastic fluctuations are present. In the latter case, we speculate there could be a "roughness" entropy whose inclusion as an effective force could compensate the constraint and preserve classical Boltzmann statistics. Regardless of the interpretation, our calculation shows the word "rolling" must be used with care when stochastic fluctuations are present.

  8. TRANSITIONAL DISKS AROUND YOUNG LOW MASS STARS

    Directory of Open Access Journals (Sweden)

    P. D'Alessio

    2009-01-01

    have been interpreted as produced by disks with inner holes, which have been classi ed as \\Transitional Disks". These disks are considered the evolutionary link between the full disks typically found around the young T Tauri and Herbig Ae stars, and the debris disks, found around some main sequence stars. In this contribution we summarize the observed/inferred characteristics of these transitional disks and also some of the models proposed to explain their peculiar geometry.

  9. Accretion of solid materials onto circumplanetary disks from protoplanetary disks

    Energy Technology Data Exchange (ETDEWEB)

    Tanigawa, Takayuki [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Maruta, Akito; Machida, Masahiro N., E-mail: tanigawa@pop.lowtem.hokudai.ac.jp [Department of Earth and Planetary Sciences, Kyushu University, Fukuoka 812-8581 (Japan)

    2014-04-01

    We investigate the accretion of solid materials onto circumplanetary disks from heliocentric orbits rotating in protoplanetary disks, which is a key process for the formation of regular satellite systems. In the late stage of the gas-capturing phase of giant planet formation, the accreting gas from protoplanetary disks forms circumplanetary disks. Since the accretion flow toward the circumplanetary disks affects the particle motion through gas drag force, we use hydrodynamic simulation data for the gas drag term to calculate the motion of solid materials. We consider a wide range of size for the solid particles (10{sup –2}-10{sup 6} m), and find that the accretion efficiency of the solid particles peaks around 10 m sized particles because energy dissipation of drag with circum-planetary disk gas in this size regime is most effective. The efficiency for particles larger than 10 m becomes lower because gas drag becomes less effective. For particles smaller than 10 m, the efficiency is lower because the particles are strongly coupled with the background gas flow, which prevents particles from accretion. We also find that the distance from the planet where the particles are captured by the circumplanetary disks is in a narrow range and well described as a function of the particle size.

  10. Minimally-invasive posterior lumbar stabilization for degenerative low back pain and sciatica. A review.

    Science.gov (United States)

    Bonaldi, G; Brembilla, C; Cianfoni, A

    2015-05-01

    The most diffused surgical techniques for stabilization of the painful degenerated and instable lumbar spine, represented by transpedicular screws and rods instrumentation with or without interbody cages or disk replacements, require widely open and/or difficult and poorly anatomical accesses. However, such surgical techniques and approaches, although still considered "standard of care", are burdened by high costs, long recovery times and several potential complications. Hence the effort to open new minimally-invasive surgical approaches to eliminate painful abnormal motion. The surgical and radiological communities are exploring, since more than a decade, alternative, minimally-invasive or even percutaneous techniques to fuse and lock an instable lumbar segment. Another promising line of research is represented by the so-called dynamic stabilization (non-fusion or motion preservation back surgery), which aims to provide stabilization to the lumbar spinal units (SUs), while maintaining their mobility and function. Risk of potential complications of traditional fusion methods (infection, CSF leaks, harvest site pain, instrumentation failure) are reduced, particularly transitional disease (i.e., the biomechanical stresses imposed on the adjacent segments, resulting in delayed degenerative changes in adjacent facet joints and discs). Dynamic stabilization modifies the distribution of loads within the SU, moving them away from sensitive (painful) areas of the SU. Basic biomechanics of the SU will be discussed, to clarify the mode of action of the different posterior stabilization devices. Most devices are minimally invasive or percutaneous, thus accessible to radiologists' interventional practice. Devices will be described, together with indications for patient selection, surgical approaches and possible complications.

  11. Minimally-invasive posterior lumbar stabilization for degenerative low back pain and sciatica. A review

    Energy Technology Data Exchange (ETDEWEB)

    Bonaldi, G., E-mail: bbonaldi@yahoo.com [Neuroradiology Department, Ospedale Papa Giovanni XXIII, Bergamo (Italy); Brembilla, C. [Department of neurosurgery, Ospedale Papa Giovanni XXIII, Bergamo (Italy); Cianfoni, A. [Neuroradiology of Neurocenter of Italian Switzerland, Lugano, CH (Switzerland)

    2015-05-15

    The most diffused surgical techniques for stabilization of the painful degenerated and instable lumbar spine, represented by transpedicular screws and rods instrumentation with or without interbody cages or disk replacements, require widely open and/or difficult and poorly anatomical accesses. However, such surgical techniques and approaches, although still considered “standard of care”, are burdened by high costs, long recovery times and several potential complications. Hence the effort to open new minimally-invasive surgical approaches to eliminate painful abnormal motion. The surgical and radiological communities are exploring, since more than a decade, alternative, minimally-invasive or even percutaneous techniques to fuse and lock an instable lumbar segment. Another promising line of research is represented by the so-called dynamic stabilization (non-fusion or motion preservation back surgery), which aims to provide stabilization to the lumbar spinal units (SUs), while maintaining their mobility and function. Risk of potential complications of traditional fusion methods (infection, CSF leaks, harvest site pain, instrumentation failure) are reduced, particularly transitional disease (i.e., the biomechanical stresses imposed on the adjacent segments, resulting in delayed degenerative changes in adjacent facet joints and discs). Dynamic stabilization modifies the distribution of loads within the SU, moving them away from sensitive (painful) areas of the SU. Basic biomechanics of the SU will be discussed, to clarify the mode of action of the different posterior stabilization devices. Most devices are minimally invasive or percutaneous, thus accessible to radiologists’ interventional practice. Devices will be described, together with indications for patient selection, surgical approaches and possible complications.

  12. The Gas Disk: Evolution and Chemistry

    Science.gov (United States)

    Rab, Christian; Baldovin-Saavedra, Carla; Dionatos, Odysseas; Vorobyov, Eduard; Güdel, Manuel

    2016-12-01

    Protoplanetary disks are the birthplaces of planetary systems. The evolution of the star-disk system and the disk chemical composition determines the initial conditions for planet formation. Therefore a comprehensive understanding of the main physical and chemical processes in disks is crucial for our understanding of planet formation. We give an overview of the early evolution of disks, discuss the importance of the stellar high-energy radiation for disk evolution and describe the general thermal and chemical structure of disks. Finally we provide an overview of observational tracers of the gas component and disk winds.

  13. The gas disk: Evolution and chemistry

    CERN Document Server

    Rab, Ch; Dionatos, O; Vorobyov, E; Güdel, Manuel

    2016-01-01

    Protoplanetary disks are the birthplaces of planetary systems. The evolution of the star-disk system and the disk chemical composition determines the initial conditions for planet formation. Therefore a comprehensive understanding of the main physical and chemical processes in disks is crucial for our understanding of planet formation. We give an overview of the early evolution of disks, discuss the importance of the stellar high-energy radiation for disk evolution and describe the general thermal and chemical structure of disks. Finally we provide an overview of observational tracers of the gas component and disk winds.

  14. Protecting geothermal operations with rupture disks

    Energy Technology Data Exchange (ETDEWEB)

    Porter, D.W.

    1983-02-01

    Potential rupture disk applications in geothermal operations are reviewed. Several wells manifolded together, to form the geothermal feed, cause erratic pressure. Rupture disks are used for relief. Flash tanks are equipped with rupture disks. Brine separators, heat exchanger shells, and turbine casings are protected by rupture disks. An analysis of geothermal steam will determine the rupture disk metal. Reverse Buckling disks are recommended over tension loaded disks for dealing with geothermal pressure cycling. Erratic temperature suggests that metals which retain tensile strength with temperature be used (Inconel is mentioned). In summary, geothermal projects represent an excellent rupture disk market.

  15. [Intra-lesional injection of betamethasone for the treatment of symptomatic pinguecula].

    Science.gov (United States)

    Arenas-Archila, E; Arellano, K; Muñoz-Sarmiento, D

    2014-10-01

    The pinguecula is a degenerative lesion which is usually asymptomatic, except when it is associated with an inflammatory reaction. We present 2 clinical cases of patients that had symptomatic pinguecula, in which intra-lesional betamethasone in depot form was used as treatment, obtaining a significant clinical improvement. The administration of intra-lesional betamethasone in depot form may be a good alternative for the treatment of the symptomatic pinguecula. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

  16. LUMBOSACRAL TRANSITIONAL ANATOMY TYPES AND DISC DEGENERATIVE CHANGES

    Directory of Open Access Journals (Sweden)

    Chabukovska Radulovska Jasminka

    2014-07-01

    Full Text Available Background and purpose: The relationship between presence of lumbo sacral transitional vertebra (LSTV and disc degenerative changes is unclear. The aim of the study was to examine the relation between different types of LSTV and disc degenerative changes at the transitional and the adjacent cephalad segment. Material and methods: Sixty-three patients (mean age 51.48 ± 13.51 out of 200 adults with low back pain who performed MRI examination of the lumbo sacral spine, classified as positive for LSTV, were included in the study. Annular tears, disc degeneration according to Phirmann classification and disc herniations were evaluated and graded at transitional and adjacent cephalad level. Results: The severity of disc degeneration at the transitional level and the adjacent level correlated with the types of LSTV. Severe disc degenerative changes were most frequent in articulated connection LSTV types and incombined LSTV type at the transitional level and in osseus connection LSTV types at the adjacent cephalad level. These changes were more frequent in unilateral articulated connection LSTV subtype (64% vs 54%; and in unilateral osseus connection LSTV subtype (25% vs no patients at transitional level, and in bilateral osseus connection LSTV subtype (100% vs 50% at the level above. High prevalence of disc herniations was observed in articulated connection LSTV types as well as in unilateral osseus connection LSTV subtype at transitional and the adjacent cephalad level. At the transitional level higher prevalence of disc herniations was characteristic for unilateral articulated connection LSTV sub type (46%vs 41% and for unilateral osseus connection LSTV subtype (50% vs no patients. At the adjacent level higher prevalence of disc herniations was observed in bilateral articulated connection LSTV subtype (38% vs 27% and in bilateral osseus connection LSTV subtype (50% vs 25%. Conclusions: The compact osseus connection (osseus bridging vs articular

  17. [Scapholunate lesions and instabilities--how to recognize and treat them?].

    Science.gov (United States)

    Papaloïzos, Michaël

    2015-06-03

    The lesions of the scapholunate ligament are some of the most frequently encountered in the wrist. Left untreated, the complete rupture of the ligament is followed by degenerative arthritis according to a well-defined pattern of progression through the wrist, eventually leading to multifocal arthrosis, a condition described as scapholunate advanced collapse (SLAC wrist). The scapholunate lesions are classified in stages according to the degree of the lesion established by imaging studies or arthroscopy and to the chronicity of the lesion. Both together essentially determine the healing potential and the prognosis, which rapidly decrease after six weeks from the initial trauma, thus indicating the importance of recognizing the acute or subacute lesion and directing the patient to the hand surgeon early enough. The therapeutic options are notably reduced and often of palliative nature in case of chronic lesions with secondary changes in the wrist mechanics or cartilage damage.

  18. 8-inch IBM floppy disk

    CERN Multimedia

    1971-01-01

    The 8-inch floppy disk was a magnetic storage disk for the data introduced commercially by IBM in 1971. It was designed by an IBM team as an inexpensive way to load data into the IBM System / 370. Plus it was a read-only bare disk containing 80 KB of data. The first read-write version was introduced in 1972 by Memorex and could contain 175 KB on 50 tracks (with 8 sectors per track). Other improvements have led to various coatings and increased capacities. Finally, it was surpassed by the mini diskette of 5.25 inches introduced in 1976.

  19. Magneto-thermal Disk Wind from Protoplanetary Disks

    CERN Document Server

    Bai, Xue-Ning; Goodman, Jeremy; Yuan, Feng

    2015-01-01

    Global evolution and dispersal of protoplanetary disks (PPDs) is governed by disk angular momentum transport and mass-loss processes. Recent numerical studies suggest that angular momentum transport in the inner region of PPDs is largely driven by magnetized disk wind, yet the wind mass-loss rate remains unconstrained. On the other hand, disk mass loss has conventionally been attributed to photoevaporation, where external heating on the disk surface drives a thermal wind. We unify the two scenarios by developing a 1D model of magnetized disk winds with a simple treatment of thermodynamics as a proxy for external heating. The wind properties largely depend on 1) the magnetic field strength at the wind base, characterized by the poloidal Alfv\\'en speed $v_{Ap}$, 2) the sound speed $c_s$ near the wind base, and 3) how rapidly poloidal field lines diverge (achieve $R^{-2}$ scaling). When $v_{Ap}\\gg c_s$, corotation is enforced near the wind base, resulting in centrifugal acceleration. Otherwise, the wind is accel...

  20. 退变性脊柱侧凸发病机制%Pathogenesis of degenerative scoliosis

    Institute of Scientific and Technical Information of China (English)

    吴炜; 王洪立; 马晓生; 姜建元

    2015-01-01

    Degenerative scoliosis is one of the main causes of low back pain and cosmetic deformity among the elderly. And it is more prevalent nowadays. Although the etiology is unclear, it is thought to be associated with osteoporosis, asymmetric degeneration, abnormal expression of gene, age, gender, etc. Better understanding the pathogenesis will be useful in the management of degenerative scoliosis.

  1. Systems Pharmacology Links GPCRs with Retinal Degenerative Disorders

    Science.gov (United States)

    Chen, Yu; Palczewski, Krzysztof

    2015-01-01

    In most biological systems, second messengers and their key regulatory and effector proteins form links between multiple cellular signaling pathways. Such signaling nodes can integrate the deleterious effects of genetic aberrations, environmental stressors, or both in complex diseases, leading to cell death by various mechanisms. Here we present a systems (network) pharmacology approach that, together with transcriptomics analyses, was used to identify different G protein–coupled receptors that experimentally protected against cellular stress and death caused by linked signaling mechanisms. We describe the application of this concept to degenerative and diabetic retinopathies in appropriate mouse models as an example. Systems pharmacology also provides an attractive framework for devising strategies to combat complex diseases by using (repurposing) US Food and Drug Administration–approved pharmacological agents. PMID:25839098

  2. Vitamin K, osteoporosis and degenerative diseases of ageing.

    Science.gov (United States)

    Vermeer, Cees; Theuwissen, Elke

    2011-03-01

    The function of vitamin K is to serve as a co-factor during the post-translational carboxylation of glutamate (Glu) residues into γ-carboxyglutamate (Gla) residues. The vital importance of the Gla-proteins essential for normal haemostasis is well recognized. During recent years, new Gla-containing proteins have been discovered and the vitamin K-dependent carboxylation is also essential for their function. It seems, however, that our dietary vitamin K intake is too low to support the carboxylation of at least some of these Gla-proteins. According to the triage theory, long-term vitamin K inadequacy is an independent, but modifiable risk factor for the development of degenerative diseases of ageing including osteoporosis and atherosclerosis.

  3. Nuclear microscopy in medical research. Investigations into degenerative diseases

    Energy Technology Data Exchange (ETDEWEB)

    Makjanic, J.; Thong, P.; Watt, F. [National University of Singapore (Singapore). Dept. of Physics

    1997-03-01

    The high energy (1-4MeV) focused ion beam (nuclear microbeam) has found uses in many scientific disciplines through a wide variety of ion beam based techniques. Of the many techniques available, the powerful combination of Particle Induced X-Ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS), and Scanning Transmission Ion Microscopy (STIM) is proving to be extremely useful, particularly in the characterisation and elemental analysis of thin specimens. In this paper we briefly review these ion beam techniques, as well as the hardware required for their application. Finally, we describe the application of the PIXE, RBS and STIM techniques in conjunction with a scanning focused 2MeV proton microbeam (nuclear microscopy). The examples chosen to illustrate the potential of nuclear microscopy are recent investigations into the degenerative diseases atherosclerosis (coronary heart disease), Parkinson`s disease and Alzheimer`s disease. (author)

  4. TRACTION-EXTENDED THERAPY OF PATIENTS WITH LUMBAR DEGENERATIVE DISEASE

    Directory of Open Access Journals (Sweden)

    V. A. Zhirnov

    2013-01-01

    Full Text Available Based on the survey of 148 patients with an lumbar degenerative disease, there have been studied immediate and medium-term results of the comprehensive conservative treatment of the patients with and without application of traction exposure on the spine. It was found out that the traction of the spine leads to a quicker and more durable relief of symptoms in comparison with the control groups where traction therapy wasn't carried out. Application of the traction-extended therapy in three planes with a usage of robotized set for dry skeletal traction of a new generation KinetracKNX-7000 is proved to increase the effectiveness of treatment for the patients with stated pathology, fasten regress of the pain syndrome and clinical symptomatology, lead to more durable and lasting remission of the desease, in comparison with the patients that had traction of the spine in one plane only during the treatment.

  5. Complement, a target for therapy in inflammatory and degenerative diseases.

    Science.gov (United States)

    Morgan, B Paul; Harris, Claire L

    2015-12-01

    The complement system is a key innate immune defence against infection and an important driver of inflammation; however, these very properties can also cause harm. Inappropriate or uncontrolled activation of complement can cause local and/or systemic inflammation, tissue damage and disease. Complement provides numerous options for drug development as it is a proteolytic cascade that involves nine specific proteases, unique multimolecular activation and lytic complexes, an arsenal of natural inhibitors, and numerous receptors that bind to activation fragments. Drug design is facilitated by the increasingly detailed structural understanding of the molecules involved in the complement system. Only two anti-complement drugs are currently on the market, but many more are being developed for diseases that include infectious, inflammatory, degenerative, traumatic and neoplastic disorders. In this Review, we describe the history, current landscape and future directions for anti-complement therapies.

  6. Osteoporosis and the Management of Spinal Degenerative Disease

    Directory of Open Access Journals (Sweden)

    Felix Tome-Bermejo

    2017-09-01

    Full Text Available Osteoporosis has become a major medical problem as the aged population of the world rapidly grows. Osteoporosispredisposes patients to fracture, progressive spinal deformities, and stenosis, and is subject to be a major concernbefore performing spine surgery, especially with bone fusions and instrumentation. Osteoporosis has often beenconsidered a contraindication for spinal surgery, while in some instances patients have undergone limited and inadequateprocedures in order to avoid concomitant instrumentation. As the population ages and the expectations of older patientsincrease, the demand for surgical treatment in older patients with osteoporosis and spinal degenerative diseasesbecomes progressively more important. Nowadays, advances in surgical and anesthetic technology make it possible tooperate successfully on elderly patients who no longer accept disabling physical conditions. This article discusses thebiomechanics of the osteoporotic spine, the diagnosis and management of osteoporotic patients with spinal conditions,as well as the novel treatments, recommendations, surgical indications, strategies and instrumentation in patients withosteoporosis who need spine operations.

  7. Cell-Based Therapy for Degenerative Retinal Disease.

    Science.gov (United States)

    Zarbin, Marco

    2016-02-01

    Stem cell-derived retinal pigment epithelium (RPE) and photoreceptors (PRs) have restored vision in preclinical models of human retinal degenerative disease. This review discusses characteristics of stem cell therapy in the eye and the challenges to clinical implementation that are being confronted today. Based on encouraging results from Phase I/II trials, the first Phase II clinical trials of stem cell-derived RPE transplantation are underway. PR transplant experiments have demonstrated restoration of visual function in preclinical models of retinitis pigmentosa and macular degeneration, but also indicate that no single approach is likely to succeed in overcoming PR loss in all cases. A greater understanding of the mechanisms controlling synapse formation as well as the immunoreactivity of transplanted retinal cells is urgently needed.

  8. Shoulder activity level and progression of degenerative cuff disease.

    Science.gov (United States)

    Keener, Jay D; Skelley, Nathan W; Stobbs-Cucchi, Georgia; Steger-May, Karen; Chamberlain, Aaron M; Aleem, Alex W; Brophy, Robert H

    2017-09-01

    This study prospectively examined the relationship of direct and indirect measures of shoulder activity with the risks of tear progression and pain development in subjects with an asymptomatic degenerative rotator cuff tear. A cohort of asymptomatic degenerative rotator cuff tears was prospectively monitored annually, documenting tear size progression with ultrasound imaging and potential shoulder pain development. Shoulder activity level, self-reported occupational and physical demand level, and hand dominance were compared with risks of tear enlargement and future pain development. The study monitored 346 individuals with a mean age of 62.1 years for a median duration of 4.1 years (interquartile range [IQR], 2.4-7.9 years). Tear enlargement was seen in 177 shoulders (51.2%), and pain developed in 161 shoulders (46.5%) over time. Tear presence in the dominant shoulder was associated with a greater risk of tear enlargement (hazard ratio, 1.40; P = .03) and pain development (hazard ratio, 1.63; P = .002). Shoulder activity level (P = .37) and occupational demand level (P = .62) were not predictive of tear enlargement. Occupational demand categories of manual labor (P = .047) and "in between" (P = .045) had greater risks of pain development than sedentary demands. The median shoulder activity score for shoulders that became painful was lower than for shoulders that remained asymptomatic (10.0 [IQR, 7.0-13.0] vs. 11.0 [IQR, 8.0-14.0], P = .02). Tear enlargement and pain development in asymptomatic tears are more common with involvement of the dominant shoulder. Shoulder activity level is not related to tear progression risks. Pain development is associated with a lower shoulder activity level even though patients with higher occupational demands are more likely to develop pain. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  9. Chondrule Transport in Protoplanetary Disks

    CERN Document Server

    Goldberg, Aaron Z; Jacquet, Emmanuel

    2015-01-01

    Chondrule formation remains one of the most elusive early Solar System events. Here, we take the novel approach of employing numerical simulations to investigate chondrule origin beyond purely cosmochemical methods. We model the transport of generically-produced chondrules and dust in a 1D viscous protoplanetary disk model, in order to constrain the chondrule formation events. For a single formation event we are able to match analytical predictions of the memory chondrule and dust populations retain of each other (complementarity), finding that a large mass accretion rate ($\\gtrsim 10^{-7}$~M$_\\odot$~yr$^{-1}$) allows for delays on the order of the disk's viscous timescale between chondrule formation and chondrite accretion. Further, we find older disks to be severely diminished of chondrules, with accretion rates $\\lesssim 10^{-9}$~M$_\\odot$~yr$^{-1}$ for nominal parameters. We then characterize the distribution of chondrule origins in both space and time, as functions of disk parameters and chondrule format...

  10. Poynting Jets from Accretion Disks

    CERN Document Server

    Lovelace, R V E; Ustyugova, G V; Romanova, M M; Colgate, S A

    2002-01-01

    The powerful narrow jets observed to emanate from many compact accreting objects may arise from the twisting of a magnetic field threading a differentially rotating accretion disk which acts to magnetically extract angular momentum and energy from the disk. Two main regimes have been discussed, {\\it hydromagnetic outflows}, which have a significant mass flux and have energy and angular momentum carried by both the matter and the electromagnetic field and, Poynting outflows, where the mass flux is negligible and energy and angular momentum are carried predominantly by the electromagnetic field. Here we consider a Keplerian disk initially threaded by a dipole-like magnetic field and we present solutions of the force-free Grad-Shafranov equation for the coronal plasma. We find solutions with Poynting jets where there is a continuous outflow of energy and toroidal magnetic flux from the disk into the external space. This behavior contradicts the commonly accepted ``theorem'' of Solar plasma physics that the motio...

  11. Secular Evolution in Disk Galaxies

    CERN Document Server

    Kormendy, John

    2013-01-01

    Self-gravitating systems evolve toward the most tightly bound configuration that is reachable via available evolution processes. The inner parts shrink and the outer parts expand, provided that some physical process transports energy or angular momentum outward. The evolution of stars, star clusters, protostellar and protoplanetary disks, black hole accretion disks, and galaxy disks are all fundamentally similar. These processes for galaxy disks are the subjects of my lectures and of this Canary Islands Winter School. Part 1 discusses formation, growth, and death of bars. Part 2 details the slow ("secular") rearrangement of angular momentum that results from interactions between stars or gas and nonaxisymmetries such as bars. We have a heuristic understanding of how this forms outer rings, inner rings, and stuff dumped into the center. Observations show that barred galaxies have central concentrations of gas and star formation. Timescales imply that they grow central "pseudobulges" that get mistaken for ellip...

  12. Gravitational Instabilities in Circumstellar Disks

    CERN Document Server

    Kratter, Kaitlin M

    2016-01-01

    [Abridged] Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review we focus on the role of gravitational instability in this process. We begin with a brief overview of the observational evidence for massive disks that might be subject to gravitational instability, and then highlight the diverse ways in which the instability manifests itself in protostellar and protoplanetary disks: the generation of spiral arms, small scale turbulence-like density fluctuations, and fragmentation of the disk itself. We present the analytic theory that describes the linear growth phase of the instability, supplemented with a survey of numerical simulations that aim to capture the non-linear evolution. We emphasize the role of thermodynamics and large scale infall in controlling the outcome of the instability. Despite apparent controversies in the literature, we show a remarkable level of agreement between analyt...

  13. Collisional Grooming of Debris Disks

    CERN Document Server

    Kuchner, Marc J

    2009-01-01

    Debris disk images show clumps, rings, warps, and other structures, many of which have been interpreted as perturbations from hidden planets. But so far, no models of these structures have properly accounted for collisions between dust grains. We have developed new steady-state 3D models of debris disks that self-consistently incorporate grain-grain collisions. We summarize our algorithm and use it to illustrate how collisions interact with resonant trapping in the presence of a planet.

  14. Heating of protostellar accretion disks

    Science.gov (United States)

    de Campos, R. R.; Jatenco-Pereira, V.

    2017-07-01

    The magneto-rotational instability (MRI) is believed to be the mechanism responsible for a magneto-hydrodynamic turbulence that could lead to the accretion observed in protoplanetary disks. The need of a minimum amount of ionization in protostellar accretion disks is necessary for the MRI to take place. There are in the literature several studies that include the damping of Alfvén waves as an additional heating source besides the viscous heating mechanism in a geometrically thin and optically thick disk. The damping of the waves transfers energy to the disk increasing the temperature and consequently its ionization fraction, making possible the presence of the MRI in a large part of the disk. We analyzed the contribution of non-ideal effects such as Ohmic and ambipolar diffusion for the disk heating and compare these heating rates with those obtained by damping of Alfvén waves. In order to study these non-ideal effects, we have estimated the radiation emission of each effect through the energy conservation equation, and associated each emission with a black body radiation, which enabled us to assign a temperature contribution of each effect. Using the ATHENA code we were able to simulate the disk at different radial distances, and estimate the electric current density needed to calculate the radiation emission associated with each effect. Once we have those data, we were able to compare the results with other heating sources, like viscosity and Alfvén waves damping, and we concluded that the Ohmic and ambipolar diffusions do not heat the disk in any significant way.

  15. Gravitational Instabilities in Circumstellar Disks

    Science.gov (United States)

    Kratter, Kaitlin; Lodato, Giuseppe

    2016-09-01

    Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review, we focus on the role of gravitational instability in this process. We begin with a brief overview of the observational evidence for massive disks that might be subject to gravitational instability and then highlight the diverse ways in which the instability manifests itself in protostellar and protoplanetary disks: the generation of spiral arms, small-scale turbulence-like density fluctuations, and fragmentation of the disk itself. We present the analytic theory that describes the linear growth phase of the instability supplemented with a survey of numerical simulations that aim to capture the nonlinear evolution. We emphasize the role of thermodynamics and large-scale infall in controlling the outcome of the instability. Despite apparent controversies in the literature, we show a remarkable level of agreement between analytic predictions and numerical results. In the next part of our review, we focus on the astrophysical consequences of the instability. We show that the disks most likely to be gravitationally unstable are young and relatively massive compared with their host star, Md/M*≥0.1. They will develop quasi-stable spiral arms that process infall from the background cloud. Although instability is less likely at later times, once infall becomes less important, the manifestations of the instability are more varied. In this regime, the disk thermodynamics, often regulated by stellar irradiation, dictates the development and evolution of the instability. In some cases the instability may lead to fragmentation into bound companions. These companions are more likely to be brown dwarfs or stars than planetary mass objects. Finally, we highlight open questions related to the development of a turbulent cascade in thin disks and the role of mode-mode coupling in setting the maximum angular

  16. Resolved observations of transition disks

    CERN Document Server

    Casassus, Simon

    2016-01-01

    Resolved observations are bringing new constraints on the origin of radial gaps in protoplanetary disks. The kinematics, sampled in detail in one case-study, are indicative of non-Keplerian flows, corresponding to warped structures and accretion which may both play a role in the development of cavities. Disk asymmetries seen in the radio continuum are being interpreted in the context of dust segregation via aerodynamic trapping. We summarise recent observational progress, and also describe prospects for improvements in the near term.

  17. Two-dimensional vortices and accretion disks

    NARCIS (Netherlands)

    Nauta, Michiel Doede

    2001-01-01

    Observations show that there are disks around certain stars that slowly rain down on the central (compact) object: accretion disks. The rate of depletion of the disk might be slow but is still larger than was expected on theoretical grounds. That is why it has been suggested that the disks are tu

  18. The Relationship of Anterior Cruciate Ligament Lesions and Osteochondral Lesions with Meniscal Tears in Patients Younger than Fifty Years of Age

    Directory of Open Access Journals (Sweden)

    Samed Ordu

    2014-09-01

    Full Text Available Aim: The purpose of this study was to determine the incidence of anterior cruciate ligament (ACL lesions and osteochondral lesions according to type and localization of the meniscal tear and age, gender in patients who have been arthroscopicaly treated, besides, to make the coexisting lesions more predictable in these patients. Methods: We retrospectively investigated 352 patients under 50 years of age who underwent surgery for a meniscal tear between 2008 and 2012. We scanned the surgical operation notes, preoperative questionnaires and the magnetic resonance imaging findings. We recorded patients who had ACL lesions, such as elongation, partial rupture and total rupture. Osteochondral lesions were classified according to the Outerbridge classification from grade 1 to grade 4. Results: Chondral lesions were present in 77.4% of patients with degenerative meniscal tears and in 63% of patients with radial meniscal tears. One the other hand, osteochondral lesions were observed in only 33.9% of patients with other types of meniscal tears. 46.6% of ACL lesions accompanied by meniscal tears with longitudinal pattern, such as longitudinal tears, bucket handle tears and root tears. For the other types of meniscal tears, this percentage was 20.7. When we excluded degenerative type meniscal tears, the mean age of the patients with radial tears was 40.86±9.03 years and the mean age of the patients with other types of tear was 35.44±9.44 years. The difference was statistically significant. Conclusion: We found close relationship between osteoarthritic chondral lesions and radial tears in the root of the posterior horn of the medial meniscus. On the other side, longitudinal tears were related with ACL lesions. (The Me­di­cal Bul­le­tin of Ha­se­ki 2014; 52: 177-80

  19. Herschel evidence for disk flattening or gas depletion in transitional disks

    CERN Document Server

    Keane, J T; Espaillat, C; Woitke, P; Andrews, S; Kamp, I; Thi, W -F; Meeus, G; Dent, W R F

    2014-01-01

    Transitional disks are protoplanetary disks characterized by reduced near- and mid-infrared emission with respect to full disks. This characteristic spectral energy distribution indicates the presence of an optically thin inner cavity within the dust disk believed to mark the disappearance of the primordial massive disk. We present new Herschel Space Observatory PACS spectra of [OI] 63 micron for 21 transitional disks. Our survey complements the larger Herschel GASPS program "Gas in Protoplanetary Systems" (Dent et al. 2013) by quadrupling the number of transitional disks observed with PACS at this wavelength. [OI] 63 micron traces material in the outer regions of the disk, beyond the inner cavity of most transitional disks. We find that transitional disks have [OI] 63 micron line luminosities two times fainter than their full disk counterparts. We self consistently determine various stellar properties (e.g. bolometric luminosity, FUV excess, etc.) and disk properties (e.g. disk dust mass, etc.) that could in...

  20. Disks around young stellar objects

    Indian Academy of Sciences (India)

    H C Bhatt

    2011-07-01

    By 1939, when Chandrasekhar’s classic monograph on the theory of Stellar Structure was published, although the need for recent star formation was fully acknowledged, no one had yet recognized an object that could be called a star in the process of being born. Young stellar objects (YSOs), as pre-main-sequence stars, were discovered in the 1940s and 1950s. Infrared excess emission and intrinsic polarization observed in these objects in the 1960s and 1970s indicated that they are surrounded by flattened disks. The YSO disks were seen in direct imaging only in the 1980s. Since then, high-resolution optical imaging with HST, near-infrared adaptive optics on large groundbased telescopes, mm and radiowave interferometry have been used to image disks around a large number of YSOs revealing disk structure with ever-increasing detail and variety. The disks around YSOs are believed to be the sites of planet formation and a few such associations have now been confirmed. The observed properties of the disk structure and their evolution, that have very important consequences for the theory of star and planet formation, are discussed.

  1. Unique psoriatic lesion versus multiple lesions

    Directory of Open Access Journals (Sweden)

    Anca Chiriac

    2014-10-01

    Full Text Available Aim: To evaluate the number of lesions of psoriasis and to find risk factors for multiple lesions. Material and Methods: 1,236 patients (male 54.13%, female 45.87% with psoriasis were seen over a period of 8 years in an Outpatient Clinic. Patients filled out questionnaires containing age at onset, number of lesions and location at the beginning of the disease, gender, type and localization of psoriasis at the time of clinical examination, psoriasis family history, previous treatment, comorbidities, and social status. Results: The number of psoriasis lesions correlates with: onset age of psoriasis (F=8.902, p=0.0029; age at the moment of clinical examination (F=8.902, p=0.0029; residence in rural area (χ2=8.589, p=0.00338, 95%CI; alcohol intake (χ2=16.47, p=0.00005, 95%CI; smoking (χ2=8.408, p=0.00373, 95%CI; occupation: workers/pupils/students (χ2=14.11, p=0.0069, 95%CI. Conclusions: There is a correlation between number of psoriatic lesions and some factors. Multiple lesions were observed in older patients, smokers and drinkers, coming from rural area and social active (workers and pupils/students. No correlation was statistically proved between number of lesions and gender, comorbidities and family history of psoriasis.

  2. Application of a semiautomatic classifier for modic and disk hernia changes in magnetic resonance

    Directory of Open Access Journals (Sweden)

    Eduardo López Arce Vivas

    2015-03-01

    Full Text Available OBJECTIVE: Early detection of degenerative changes in lumbar intervertebral disc by magnetic resonance imaging in a semiautomatic classifier for prevention of degenerative disease. METHOD: MRIs were selected with a diagnosis of degenerative disc disease or back pain from January to May 2014, with a sample of 23 patients and a total of 170 disks evaluated by sagittal T2 MRI image, first evaluated by a specialist physician in training and them were introduced into the software, being the results compared. RESULTS: One hundred and fifteen discs were evaluated by a programmed semiautomatic classifier to identify MODIC changes and hernia, which produced results "normal or MODIC" and "normal or abnormal", respectively. With a total of 230 readings, of which 141 were correct, 84 were reading errors and 10 readings were undiagnosed, the semiautomatic classifier is a useful tool for early diagnosis or established disease and is easy to apply because of the speed and ease of use; however, at this early stage of development, software is inferior to clinical observations and the results were from around 65% to 60% certainty for MODIC rating and 61% to 58% for disc herniation, compared with clinical evaluations. CONCLUSION: The comparative results between the two doctors were 94 consistent results and only 21 errors, which represents 81% certainty.

  3. Global Models for Embedded, Accreting Protostellar Disks

    CERN Document Server

    Kratter, Kaitlin M; Krumholz, Mark R

    2007-01-01

    Most analytic work to date on protostellar disks has focused on disks in isolation from their environments. However, observations are now beginning to probe the earliest, most embedded phases of star formation, during which disks are rapidly accreting from their parent cores and cannot be modeled in isolation. We present a simple, one-zone model of protostellar accretion disks with high mass infall rates. Our model combines a self-consistent calculation of disk temperatures with an approximate treatment of angular momentum transport via several mechanisms. We use this model to survey the properties of protostellar disks across a wide range of stellar masses and evolutionary times, and make predictions for disks' masses, sizes, spiral structure, and fragmentation that will be directly testable by future large-scale surveys of deeply embedded disks. We define a dimensionless accretion-rotation parameter which, in conjunction with the disk's temperature, controls the disk evolution. We track the dominant mode of...

  4. Fragmentation of Kozai–Lidov Disks

    Science.gov (United States)

    Fu, Wen; Lubow, Stephen H.; Martin, Rebecca G.

    2017-02-01

    We analyze the gravitational instability (GI) of a locally isothermal inclined disk around one component of a binary system. Such a disk can undergo global Kozai–Lidov (KL) cycles if the initial disk tilt is above the critical KL angle (of about 40◦). During these cycles, an initially circular disk exchanges its inclination for eccentricity, and vice versa. Self-gravity may suppress the cycles under some circumstances. However, with hydrodynamic simulations that include self-gravity, we show that for a sufficiently high initial disk tilts and for certain disk masses, disks can undergo KL oscillations and fragment due to GI, even when the Toomre Q value for an equivalent undisturbed disk is well within the stable regime (Q> 2). We suggest that KL triggered disk fragmentation provides a mechanism for the efficient formation of giant planets in binary systems and may enhance the fragmentation of disks in massive black hole binaries.

  5. Quantitative analysis of (18)F-NaF dynamic PET/CT cannot differentiate malignant from benign lesions in multiple myeloma.

    Science.gov (United States)

    Sachpekidis, Christos; Hillengass, Jens; Goldschmidt, Hartmut; Anwar, Hoda; Haberkorn, Uwe; Dimitrakopoulou-Strauss, Antonia

    2017-01-01

    A renewed interest has been recently developed for the highly sensitive bone-seeking radiopharmaceutical (18)F-NaF. Aim of the present study is to evaluate the potential utility of quantitative analysis of (18)F-NaF dynamic PET/CT data in differentiating malignant from benign degenerative lesions in multiple myeloma (MM). 80 MM patients underwent whole-body PET/CT and dynamic PET/CT scanning of the pelvis with (18)F-NaF. PET/CT data evaluation was based on visual (qualitative) assessment, semi-quantitative (SUV) calculations, and absolute quantitative estimations after application of a 2-tissue compartment model and a non-compartmental approach leading to the extraction of fractal dimension (FD). In total 263 MM lesions were demonstrated on (18)F-NaF PET/CT. Semi-quantitative and quantitative evaluations were performed for 25 MM lesions as well as for 25 benign, degenerative and traumatic lesions. Mean SUVaverage for MM lesions was 11.9 and mean SUVmax was 23.2. Respectively, SUVaverage and SUVmax for degenerative lesions were 13.5 and 20.2. Kinetic analysis of (18)F-NaF revealed the following mean values for MM lesions: K1 = 0.248 (1/min), k3 = 0.359 (1/min), influx (Ki) = 0.107 (1/min), FD = 1.382, while the respective values for degenerative lesions were: K1 = 0.169 (1/min), k3 = 0.422 (1/min), influx (Ki) = 0.095 (1/min), FD = 1. 411. No statistically significant differences between MM and benign degenerative disease regarding SUVaverage, SUVmax, K1, k3 and influx (Ki) were demonstrated. FD was significantly higher in degenerative than in malignant lesions. The present findings show that quantitative analysis of (18)F-NaF PET data cannot differentiate malignant from benign degenerative lesions in MM patients, supporting previously published results, which reflect the limited role of (18)F-NaF PET/CT in the diagnostic workup of MM.

  6. Magneto-thermal Disk Winds from Protoplanetary Disks

    Science.gov (United States)

    Bai, Xue-Ning; Ye, Jiani; Goodman, Jeremy; Yuan, Feng

    2016-02-01

    The global evolution and dispersal of protoplanetary disks (PPDs) are governed by disk angular-momentum transport and mass-loss processes. Recent numerical studies suggest that angular-momentum transport in the inner region of PPDs is largely driven by magnetized disk wind, yet the wind mass-loss rate remains unconstrained. On the other hand, disk mass loss has conventionally been attributed to photoevaporation, where external heating on the disk surface drives a thermal wind. We unify the two scenarios by developing a one-dimensional model of magnetized disk winds with a simple treatment of thermodynamics as a proxy for external heating. The wind properties largely depend on (1) the magnetic field strength at the wind base, characterized by the poloidal Alfvén speed vAp, (2) the sound speed cs near the wind base, and (3) how rapidly poloidal field lines diverge (achieve {R}-2 scaling). When {v}{Ap}\\gg {c}{{s}}, corotation is enforced near the wind base, resulting in centrifugal acceleration. Otherwise, the wind is accelerated mainly by the pressure of the toroidal magnetic field. In both cases, the dominant role played by magnetic forces likely yields wind outflow rates that exceed purely hydrodynamical mechanisms. For typical PPD accretion-rate and wind-launching conditions, we expect vAp to be comparable to cs at the wind base. The resulting wind is heavily loaded, with a total wind mass-loss rate likely reaching a considerable fraction of the wind-driven accretion rate. Implications for modeling global disk evolution and planet formation are also discussed.

  7. Covering and piercing disks with two centers

    KAUST Repository

    Ahn, Heekap

    2013-04-01

    We give exact and approximation algorithms for two-center problems when the input is a set D of disks in the plane. We first study the problem of finding two smallest congruent disks such that each disk in D intersects one of these two disks. Then we study the problem of covering the set D by two smallest congruent disks. © 2012 Elsevier B.V.

  8. Covering and piercing disks with two centers

    KAUST Repository

    Ahn, Heekap

    2011-01-01

    We consider new versions of the two-center problem where the input consists of a set D of disks in the plane. We first study the problem of finding two smallest congruent disks such that each disk in intersects one of these two disks. Then we study the problem of covering the set D by two smallest congruent disks. We give exact and approximation algorithms for these versions. © 2011 Springer-Verlag.

  9. Timescales of Disk Evolution and Planet Formation

    CERN Document Server

    Jayawarhana, R

    2000-01-01

    It has been suggested that circumstellar disks evolve from dense, actively accreting structures to low-mass, replenished remnants. During this transition, grains may assemble into planetesimals, or the disk may be cleared by newborn planets. Recently identified nearby groups of young stars provide valuable laboratories for probing disk evolution. I discuss the properties of dust disks in the TW Hydrae Association and the MBM 12 cloud, and compare the results to other studies of disk evolution and planet formation timescales.

  10. Non-joint effusion is associated with osteoarthritis in temporomandibular joints with disk displacement.

    Science.gov (United States)

    Zheng, Zhi-Wei; Yang, Chi; Wang, Mei-Hao; Zhu, Xing-Hao; Fang, Yi-Ming

    2016-01-01

    The aim of this study was to examine the possible association between different grades of joint effusion (JE) and osteoarthritis (OA) in temporomandibular joint (TMJ) anterior disk displacement without reduction (ADDwoR). A sample of 101 female patients 20-40 years of age with unilateral TMJ ADDwoR were retrospectively reviewed. JE and OA were diagnosed with magnetic resonance imaging (MRI). JE was subdivided into three different grades: grade 0, no or minimal effusion; grade 1, moderate effusion; and grade 2, extensive effusion. Eight categories of degenerative changes were used for screening for the existence of OA. Cases with no less than one type of degenerative change were diagnosed as OA. In all, 71 patients (70.3%) were diagnosed as having OA in the joints with disk displacement. In the univariate analysis, the proportion of subjects with non-JE (grade 0) was higher in the OA group (p = 0.003), while the proportion of subjects with extensive effusion (grade 2) was lower in the OA group (p = 0.02). In the multivariate logistic regression analysis, non-JE was independently associated with the development of OA (odds ratio = 5.68, 95% confidence interval = 1.10-29.37, P = 0.04). The results suggested that non-JE was associated with OA in the joints with ADDwoR. Copyright © 2015. Published by Elsevier Ltd.

  11. Research Progress of Lumbar Degenerative Disease%腰椎间盘退变性疾病的研究进展

    Institute of Scientific and Technical Information of China (English)

    乔成钢; 杨学军

    2015-01-01

    As a common spinal diseases, lumbar degenerative disk diease (LDDD) is defined by relevant scholars as the general name of a series of disease which have the clinical manifestation of waist and leg pain caused by degenerative changes of lumbar disc, articular process cartilages and surrounding ligament, and it always results in degenerative lumbar spinal stenosis and spondylolisthesis. Its clinical effect is not good because of complex causes and undefined pathogenesis. This paper reviews the progress of many new technologies such as gene technology and biology which greatly improve the research progress of LDDD in recent years so as to provide reference for clinical study.%LDDD属于临床常见脊柱疾病,相关学者将其定义为,因腰椎间盘与关节突的关节软骨及周围韧带退行性变化所致腰腿疼痛等临床表现一系列疾病总称,多造成退变性腰椎管狭窄、腰椎滑脱等病变。 LDDD病因较为复杂,且尚未明确其发病机制,因而临床未能取得理想疗效。近年来,诸多新技术如基因技术生物学,极大促进了LDDD的研究进展,该研究对其具体进展进行综合论述,以期为临床研究提供参考。

  12. Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.L.; Kaplan, P.A.; Dussault, R.G.; Anderson, M.W. [Dept. of Radiology, Univ. of Virginia Health System, Charlottesville, VA (United States)

    2000-12-01

    Objective. Signal intensity changes in lumbar pedicles, similar to those described in vertebral body endplates adjacent to degenerated discs, have been described as an ancillary sign of spondylolysis on MRI. The purpose of this study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease.Design. Eighty-nine lumbar spine MRI examinations without spondylolysis were reviewed for marrow signal intensity changes in pedicles and vertebral bodies as well as for facet degenerative joint disease.Results. Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedicles had adjacent degenerative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001). Eighty-nine percent (41/46) of the pedicles with marrow signal intensity changes had adjacent degenerative disc disease.Conclusions. Pedicle marrow signal intensity changes are not a specific sign of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal intensity changes are probably a response to abnormal stresses related to abnormal motion or loading caused by the degenerative changes in the spinal segment. (orig.)

  13. Anatomical basics, variations, and degenerative changes of the shoulder joint and shoulder girdle

    Energy Technology Data Exchange (ETDEWEB)

    Prescher, Andreas E-mail: dkeyserlingk@post.klinikum.rwth-aachen.de

    2000-08-01

    This paper summarizes the anatomical basics of the shoulder, their variations, and precise definitions, including differential diagnoses. It also describes the characteristic degenerative changes caused by aging. A typical variation (7-15%) is the os acromiale, which forms the triangular epiphysis of the scapular spine. This abnormality must be differentiated from a fracture of the acromion or a pseudarthrosis. Because ossification of the acromion is complete after age 25, the os acromiale should be diagnosed only after this age. The shape of the acromion is a further important feature. In a recent anatomical study, the following frequencies of the Bigliani-types of the acromial shape were anatomically determined - type 1 (flat), 10.2% and type 2 (curved), 89.8%. Type 3 (hooked) was not observed, which indicates that this type is probably a misinterpretation of the so-called acromial spur. Minor dehiscences and perforations in the infraspinate or supraspinate fossa should not be confused with malignant osteolyses. The scapula has three ligaments of its own, (1) the coracoacromial ligament and its osseous fixations form an osteofibrous arch above the shoulder joint, which plays a part in impingement syndrome; (2) the superior transverse scapular ligament or its ossified correlate arches the scapular incisure and can cause a typical compression syndrome of the suprascapular nerve; (3) the inferior transverse scapular ligament is of no great clinical importance. Two intraarticular structures (glenoid labrum and tendon of the long bicipital head) must be mentioned. The glenoid labrum consists of dense connective tissue and surrounds the margin of the glenoid cavity. Two areas exhibit specialized conditions, cranial at the supraglenoid tubercle an intimate relationship exists to the tendon of the long bicipital head and in about 55% of cases, the labrum is stretched over the glenoid rim at the ventral side. At the area of the biceps-tendon-labrum complex, so-called SLAP-lesions

  14. Total knee replacement for posttraumatic degenerative arthritis of the knee

    Institute of Scientific and Technical Information of China (English)

    WU Li-dong; XIONG Yan; YAN Shi-gui; YANG Quan-sen

    2005-01-01

    Objective: To evaluate the results of total knee arthroplasty (TKA) in patients with posttraumatic degenerative arthritis due to a previous fracture around the knee. Methods: We analyzed the results of 15 TKAs, performed from 1997 to 2003, in 15 patients with post-traumatic degenerative arthritis due to a previous fracture around knee. There were 3 women and 12 men with an average age of 58 years (range, 31-76 years). The time from fracture to arthroplasty averaged 8.2 years (range, 2-27 years). Internal fixation had previously been performed in 8 patients resulting in retained hardware. At the time of arthroplasty a femoral fracture malunion was present in two knees. Lateral retinacular release (4 knees), extensor mechanism realignment (1 knee) or medial collateral ligament reconstruction (1 knee) were needed at the time of arthroplasty. Results: Follow-up averaged 35 months (range, 12-73 months). No patient was lost for follow-up. According to the Knee Society Score scale, the mean preoperative knee score was 37 (range, 10-70) and functional score was 41 (range, 0-60). They were improved significantly to a mean of 84 (range, 10-100) and 76 (range, 20-100) points, respectively at the latest follow-up. The mean knee arc of motion were improved from 84° preoperation to 94° at the latest follow-up. Postoperative manipulation under anesthesia for poor motion was carried out in 4 knees. No knee had aseptic loosening that required subsequent revision. Two knees developed superficial infection and were treated with debridement. It subsequently recovered with the retention of components. Conclusions: Significant improvement in function and relief of pain has been achieved in patients with previous fractures undergoing subsequent TKA. However, this procedure is technically demanding and patients are at increased risk for restricted motion and need more care following TKA. This study suggests that the outcome of TKA may be improved further by making special efforts to

  15. Ultrafast disk lasers and amplifiers

    Science.gov (United States)

    Sutter, Dirk H.; Kleinbauer, Jochen; Bauer, Dominik; Wolf, Martin; Tan, Chuong; Gebs, Raphael; Budnicki, Aleksander; Wagenblast, Philipp; Weiler, Sascha

    2012-03-01

    Disk lasers with multi-kW continuous wave (CW) output power are widely used in manufacturing, primarily for cutting and welding applications, notably in the automotive industry. The ytterbium disk technology combines high power (average and/or peak power), excellent beam quality, high efficiency, and high reliability with low investment and operating costs. Fundamental mode picosecond disk lasers are well established in micro machining at high throughput and perfect precision. Following the world's first market introduction of industrial grade 50 W picosecond lasers (TruMicro 5050) at the Photonics West 2008, the second generation of the TruMicro series 5000 now provides twice the average power (100 W at 1030 nm, or 60 W frequency doubled, green output) at a significantly reduced footprint. Mode-locked disk oscillators achieve by far the highest average power of any unamplified lasers, significantly exceeding the 100 W level in laboratory set-ups. With robust long resonators their multi-microjoule pulse energies begin to compete with typical ultrafast amplifiers. In addition, significant interest in disk technology has recently come from the extreme light laser community, aiming for ultra-high peak powers of petawatts and beyond.

  16. Disk Instabilities and Cooling Fronts

    CERN Document Server

    Vishniac, E T

    1998-01-01

    Accretion disk outbursts, and their subsequent decline, offer a unique opportunity to constrain the physics of angular momentum transport in hot accretion disks. Recent work has centered on the claim by Cannizzo et al. that the exponential decay of luminosity following an outburst in black hole accretion disk systems is only consistent with a particular form for the dimensionless viscosity, $\\alpha=35(c_s/r\\Omega)^{3/2}$. This result can be understood in terms of a simple model of the evolution of cooling fronts in accretion disks. In particular, the cooling front speed during decline is $\\sim cooling front, and the exact value of $n$ depends on the hot state opacity, (although generally $n\\approx 1/2$). Setting this speed proportional to $r$ constrains the functional form of $\\alpha$ in the hot phase of the disk, which sets it apart from previous arguments based on the relative durations of outburst and quiescence. However, it remains uncertain how well we know the exponent $n$. In addition, more work is nee...

  17. Simultaneity on the Rotating Disk

    Science.gov (United States)

    Koks, Don

    2017-04-01

    The disk that rotates in an inertial frame in special relativity has long been analysed by assuming a Lorentz contraction of its peripheral elements in that frame, which has produced widely varying views in the literature. We show that this assumption is unnecessary for a disk that corresponds to the simplest form of rotation in special relativity. After constructing such a disk and showing that observers at rest on it do not constitute a true rotating frame, we choose a "master" observer and calculate a set of disk coordinates and spacetime metric pertinent to that observer. We use this formalism to resolve the "circular twin paradox", then calculate the speed of light sent around the periphery as measured by the master observer, to show that this speed is a function of sent-direction and disk angle traversed. This result is consistent with the Sagnac Effect, but constitutes a finer analysis of that effect, which is normally expressed using an average speed for a full trip of the periphery. We also use the formalism to give a resolution of "Selleri's paradox".

  18. Splenial lesions of the corpus callosum: Disease Spectrum and MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Eun; Choi, Dae Seob; Shin, Hwa Seon; Baek, Hye Jin; Choi, Ho Cheol; Kim, Ji Eun; Choi, Hye Young; Park, Min Jung [Dept. of Radiology, Gyeongsang National University School of Medicine, Jinju (Korea, Republic of)

    2017-08-01

    The corpus callosum (CC) is the largest white matter structure in the brain, consisting of more than 200–250 million axons that provide a large connection mainly between homologous cerebral cortical areas in mirror image sites. The posterior end of the CC is the thickest part, which is called the slenium. Various diseases including congenital to acquired lesions including congenital anomalies, traumatic lesions, ischemic diseases, tumors, metabolic, toxic, degenerative, and demyelinating diseases, can involve the splenium of the CC and their clinical symptoms and signs are also variable. Therefore, knowledge of the disease entities and the imaging findings of lesions involving the splenium is valuable in clinical practice. MR imaging is useful for the detection and differential diagnosis of splenial lesions of the CC. In this study, we classify the disease entities and describe imaging findings of lesions involving the splenium of the CC based on our experiences and a review of the literature.

  19. Contralateral interlaminar approach for intraforaminal lumbar degenerative disease with special emphasis on L5-S1 level: A technical note

    Science.gov (United States)

    Zekaj, Edvin; Menghetti, Claudia; Saleh, Christian; Isidori, Alessandra; Bona, Alberto R.; Aimar, Enrico; Servello, Domenico

    2016-01-01

    Background: Intraforaminal disc herniations at the L5-S1 level are extremely surgically challenging lesions. Intracanal approaches frequently require partial or total facetectomy, which may lead to instability. Solely extraforaminal approaches may offer limited visualization of the more medial superiorly exiting and inferiorly exiting nerve roots; this approach is also more complicated at L5-S1 due to the often large L5 transverse process and the iliac wing. Methods: Nine patients with intraforaminal L5-S1 disc herniations, foraminal stenosis, or synovial cysts underwent contralateral interlaminar approaches for lesion resection. Preoperative and postoperative visual analog scale scores were evaluated, and complications were reviewed. Results: All 9 patients demonstrated immediate postoperative clinical improvement. None of the patients exhibited complications and none developed instability or neuropathic disorders. Conclusions: Although the number of cases in our sample was very small (9 in total), the contralateral interlaminar approach appeared to effectively address multiple degenerative L5-S1 foraminal pathologies. Large studies are needed to further evaluate the pros and cons of this approach. PMID:27713854

  20. [Complex outpatient care to patients with osteoarthrosis and degenerative-dystrophic diseases of juxtaarticular soft tissues].

    Science.gov (United States)

    Saks, L A

    2014-04-01

    The aim of the article is an evaluation of effectiveness of the complex outpatient care to patients with osteoarthrosis and degenerative-dystrophic diseases ofjuxtaarticular soft tissues. Recent researches showed that the key factors of the pathogenesis of diseases were degenerative-dystrophic and inflammatory changes in the synovio-entheseal complex ofparaarticular muscles' tendon. 411 patients with osteoarthrosis of 531 synovial joints and degenerative-dystrophic diseases of periarticular soft tissues underwent sequential corticosteroid therapy combined with hyaluronic acid injections. In 84% of cases positive results were observed.

  1. Vertebral degenerative disc disease severity evaluation using random forest classification

    Science.gov (United States)

    Munoz, Hector E.; Yao, Jianhua; Burns, Joseph E.; Pham, Yasuyuki; Stieger, James; Summers, Ronald M.

    2014-03-01

    Degenerative disc disease (DDD) develops in the spine as vertebral discs degenerate and osseous excrescences or outgrowths naturally form to restabilize unstable segments of the spine. These osseous excrescences, or osteophytes, may progress or stabilize in size as the spine reaches a new equilibrium point. We have previously created a CAD system that detects DDD. This paper presents a new system to determine the severity of DDD of individual vertebral levels. This will be useful to monitor the progress of developing DDD, as rapid growth may indicate that there is a greater stabilization problem that should be addressed. The existing DDD CAD system extracts the spine from CT images and segments the cortical shell of individual levels with a dual-surface model. The cortical shell is unwrapped, and is analyzed to detect the hyperdense regions of DDD. Three radiologists scored the severity of DDD of each disc space of 46 CT scans. Radiologists' scores and features generated from CAD detections were used to train a random forest classifier. The classifier then assessed the severity of DDD at each vertebral disc level. The agreement between the computer severity score and the average radiologist's score had a quadratic weighted Cohen's kappa of 0.64.

  2. Environmental Radon Gas and Degenerative Conditions An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Groves-Kirkby, C.J. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom)]|[School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom); Denman, A.R. [Medical Physics Department, Northampton General Hospital, Northampton NN1 5BD (United Kingdom); Woolridge, A.C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)]|[School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, P.S. [School of Applied Sciences, University of Northampton, Northampton NN2 7AL (United Kingdom); Phillips, C. [School of Health, University of Northampton, Northampton NN2 7AL (United Kingdom)

    2006-07-01

    Radon, a naturally occurring radioactive gas, has variable distribution in the environment as a decay product of uranium occurring in a wide range of rocks, soils and building materials. Although radon dissipates rapidly in outdoor air, it concentrates in the built environment, and inhalation of {sup 222}Rn and its progeny {sup 218}Po and {sup 214}Po is believed to provide the majority of the radioactive dose to the respiratory system. While the connection between radon and lung cancer has long been recognised and investigated, recent studies have highlighted potential links between radon and other conditions, among them Multiple Sclerosis, Alzheimer and Parkinson Diseases, and Paget Disease of Bone. A strong case exists for clarifying the relationship between radon and these other conditions, not least since radon remediation to reduce lung cancer may conceivably have additional benefits hitherto unrecognized. The present status of the postulated links between environmental radon gas and degenerative conditions is reviewed, and recommendations for further research into levering current anti-radon campaigns are made. (authors)

  3. The ubiquitin-proteasome system in spongiform degenerative disorders.

    Science.gov (United States)

    Whatley, Brandi R; Li, Lian; Chin, Lih-Shen

    2008-12-01

    Spongiform degeneration is characterized by vacuolation in nervous tissue accompanied by neuronal death and gliosis. Although spongiform degeneration is a hallmark of prion diseases, this pathology is also present in the brains of patients suffering from Alzheimer's disease, diffuse Lewy body disease, human immunodeficiency virus (HIV) infection, and Canavan's spongiform leukodystrophy. The shared outcome of spongiform degeneration in these diverse diseases suggests that common cellular mechanisms must underlie the processes of spongiform change and neurodegeneration in the central nervous system. Immunohistochemical analysis of brain tissues reveals increased ubiquitin immunoreactivity in and around areas of spongiform change, suggesting the involvement of ubiquitin-proteasome system dysfunction in the pathogenesis of spongiform neurodegeneration. The link between aberrant ubiquitination and spongiform neurodegeneration has been strengthened by the discovery that a null mutation in the E3 ubiquitin-protein ligase mahogunin ring finger-1 (Mgrn1) causes an autosomal recessively inherited form of spongiform neurodegeneration in animals. Recent studies have begun to suggest that abnormal ubiquitination may alter intracellular signaling and cell functions via proteasome-dependent and proteasome-independent mechanisms, leading to spongiform degeneration and neuronal cell death. Further elucidation of the pathogenic pathways involved in spongiform neurodegeneration should facilitate the development of novel rational therapies for treating prion diseases, HIV infection, and other spongiform degenerative disorders.

  4. The Milky Way's Stellar Disk

    CERN Document Server

    Rix, Hans-Walter

    2013-01-01

    A suite of vast stellar surveys mapping the Milky Way, culminating in the Gaia mission, is revolutionizing the empirical information about the distribution and properties of stars in the Galactic stellar disk. We review and lay out what analysis and modeling machinery needs to be in place to test mechanisms of disk galaxy evolution and to stringently constrain the Galactic gravitational potential, using such Galactic star-by-star measurements. We stress the crucial role of stellar survey selection functions in any such modeling; and we advocate the utility of viewing the Galactic stellar disk as made up from `mono-abundance populations' (MAPs), both for dynamical modeling and for constraining the Milky Way's evolutionary processes. We review recent work on the spatial and kinematical distribution of MAPs, and lay out how further study of MAPs in the Gaia era should lead to a decisively clearer picture of the Milky Way's dark matter distribution and formation history.

  5. Wallis棘突间动态固定防治腰椎退变的短期效果%Early clinical observation of Wallis interspinous dynamic stabilization in treatment of lumbar degenerative disease

    Institute of Scientific and Technical Information of China (English)

    杨述华; 许伟华; 叶树楠; 唐欣; 吴星火; 刘先哲; 王晶

    2009-01-01

    Objective To summarize the early experience of the implantation of Wallis posterior dynamic stabilization system for the treatment of early lumbar degenerative disease.Methods During January 2007 to May 2008, 36 patients (37 intervertebral spaces) with early lumbar degenerative disease were treated with Wallis system.There were 23 males and 13 females; 1 case of L2-3, 1 case L3-4-5 intervertebral space, and 35 cases are L4-5 intervertebral space.The spinous process of the segment with intervertebral disk hernia was not excised, and the Wallis system was implanted after the excision of herniated disk with spinal microscope.The JOA and visual analogue scale (VAS) were given before and after the operation.The patients were followed up for average 13.5 months (range, 3-17 months) after the operation.Results The evaluation of therapeutic effect was excellent except 1 case.JOA score were 15-17 with the average of 16.3, and VAS were 0-2 with the average of 0.6.The MRI showed that no compression of spinal cord and improvement of disc signal.The degeneration of the proximal disc did not aggravate.No leakage of cerebrospinal fluid, infection or hernia of residual intervertebral disk.No recur of intervertebral disk hernia and displace of the Wallis system.Conclusion The Wallis posterior dynamic stabilization system, as a non-rigid fixation technique, can preserve the mobility, anatomy and stability of operated lumbar vertebral bodies, promote the recover of the lesion discs, and prevent the degeneration of adjacent discs.%目的 总结Wallis棘突间动态稳定系统置入治疗早期腰椎退变性疾病的短期疗效.方法 2007年1月至2008年5月,共治疗36例(37间隙)腰椎间盘突出症患者.L2-3 1例,L3-4并L4-5 1例,其余均为L4-5间隙.男23例,女13例;年龄38~55岁,平均43岁.手术保留椎间盘突出节段棘突,以脊柱显微镜配合摘除突出的椎间盘,置入Wallis棘突间动态稳定系统并固定缝合.对

  6. Adrenal hyperplastic and degenerative changes in beluga whales.

    Science.gov (United States)

    Lair, S; Béland, P; De Guise, S; Martineau, D

    1997-07-01

    Thirty stranded beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary (Quebec, Canada) population and five animals from the Hudson Bay aboriginal hunt (North-west Territories, Canada) were examined. Twenty one animals from the St. Lawrence Estuary had mild to severe adrenal lesions and four whales from the Hudson Bay population were affected by minimal adrenal changes. Cortical hyperplasia was observed in 24 adult beluga whales all from the St. Lawrence Estuary. Bilateral cortical cysts and cellular vacuolar degeneration were observed in the adrenal glands of 19 beluga whales from both populations. The cysts, filled with a cortisol-rich liquid, were present in both sexes. Beluga whales with adrenal cysts were significantly older than animals without cysts, and the severity of the lesions increased with age. Nodular hyperplasia of the medulla was observed in seven of the beluga whales, all from the St. Lawrence Estuary population. All lesions could be part of a normal aging process. The adrenocortical lesions might be due to stress or adrenocorticolytic xenobiotics, while the medullary hyperplasia might be caused by hypoxia or exposure to estrogenic xenobiotics.

  7. Dust Evolution in Protoplanetary Disks

    Science.gov (United States)

    Testi, L.; Birnstiel, T.; Ricci, L.; Andrews, S.; Blum, J.; Carpenter, J.; Dominik, C.; Isella, A.; Natta, A.; Williams, J. P.; Wilner, D. J.

    In the core-accretion scenario for the formation of planetary rocky cores, the first step toward planet formation is the growth of dust grains into larger and larger aggregates and eventually planetesimals. Although dust grains are thought to grow up to micrometer-sized particles in the dense regions of molecular clouds, the growth to pebbles and kilometer-sized bodies must occur at the high densities within protoplanetary disks. This critical step is the last stage of solids evolution that can be observed directly in extrasolar systems before the appearance of large planetary-sized bodies. In this chapter we review the constraints on the physics of grain-grain collisions as they have emerged from laboratory experiments and numerical computations. We then review the current theoretical understanding of the global processes governing the evolution of solids in protoplanetary disks, including dust settling, growth, and radial transport. The predicted observational signatures of these processes are summarized. We briefly discuss grain growth in molecular cloud cores and in collapsing envelopes of protostars, as these likely provide the initial conditions for the dust in protoplanetary disks. We then review the observational constraints on grain growth in disks from millimeter surveys, as well as the very recent evidence for radial variations of the dust properties in disks. We also include a brief discussion on the small end of the grain size distribution and dust settling as derived from optical, near-, and mid-infrared observations. Results are discussed in the context of global dust-evolution models; in particular, we focus on the emerging evidence for a very efficient early growth of grains and the radial distribution of maximum grain sizes as the result of growth barriers. We also highlight the limits of the current models of dust evolution in disks, including the need to slow the radial drift of grains to overcome the migration/fragmentation barrier.

  8. Dust in protoplanetary disks: observations*

    Directory of Open Access Journals (Sweden)

    Waters L.B.F.M.

    2015-01-01

    Full Text Available Solid particles, usually referred to as dust, are a crucial component of interstellar matter and of planet forming disks surrounding young stars. Despite the relatively small mass fraction of ≈1% (in the solar neighborhood of our galaxy; this number may differ substantially in other galaxies that interstellar grains represent of the total mass budget of interstellar matter, dust grains play an important role in the physics and chemistry of interstellar matter. This is because of the opacity dust grains at short (optical, UV wavelengths, and the surface they provide for chemical reactions. In addition, dust grains play a pivotal role in the planet formation process: in the core accretion model of planet formation, the growth of dust grains from the microscopic size range to large, cm-sized or larger grains is the first step in planet formation. Not only the grain size distribution is affected by planet formation. Chemical and physical processes alter the structure and chemical composition of dust grains as they enter the protoplanetary disk and move closer to the forming star. Therefore, a lot can be learned about the way stars and planets are formed by observations of dust in protoplanetary disks. Ideally, one would like to measure the dust mass, the grain size distribution, grain structure (porosity, fluffiness, the chemical composition, and all of these as a function of position in the disk. Fortunately, several observational diagnostics are available to derive constrains on these quantities. In combination with rapidly increasing quality of the data (spatial and spectral resolution, a lot of progress has been made in our understanding of dust evolution in protoplanetary disks. An excellent review of dust evolution in protoplanetary disks can be found in Testi et al. (2014.

  9. Nonaxisymmetric evolution in protostellar disks

    Science.gov (United States)

    Laughlin, Gregory; Bodenheimer, Peter

    1994-01-01

    We present a two-dimensional, multigridded hydrodynamical simulation of the collapse of an axisymmetric, rotating, 1 solar mass protostellar cloud, which forms a resolved, hydrotastic disk. The code includes the effects of physical viscosity, radiative transfer and radiative acceleration but not magnetic fields. We examine how the disk is affected by the inclusion of turbulent viscosity by comparing a viscous simulation with an inviscid model evolved from the same initial conditions, and we derive a disk evolutionary timescale on the order of 300,000 years if alpha = 0.01. Effects arising from non-axisymmetric gravitational instabilities in the protostellar disk are followed with a three-dimensional SPH code, starting from the two-dimensional structure. We find that the disk is prone to a series of spiral instabilities with primary azimulthal mode number m = 1 and m = 2. The torques induced by these nonaxisymmetric structures elicit material transport of angular momentum and mass through the disk, readjusting the surface density profile toward more stable configurations. We present a series of analyses which characterize both the development and the likely source of the instabilities. We speculate that an evolving disk which maintains a minimum Toomre Q-value approximately 1.4 will have a total evolutionary span of several times 10(exp 5) years, comparable to, but somewhat shorter than the evolutionary timescale resulting from viscous turbulence alone. We compare the evolution resulting from nonaxisymmetric instabilities with solutions of a one-dimensional viscous diffusion equation applied to the initial surface density and temperature profile. We find that an effective alpha-value of 0.03 is a good fit to the results of the simulation. However, the effective alpha will depend on the minimum Q in the disk at the time the instability is activated. We argue that the major fraction of the transport characterized by the value of alpha is due to the action of

  10. The Herschel Cold Debris Disks

    CERN Document Server

    Gaspar, Andras

    2013-01-01

    The Herschel "DUst around NEarby Stars (DUNES)" survey has found a number of debris disk candidates that are apparently very cold, with temperatures near 22K. It has proven difficult to fit their spectral energy distributions with conventional models for debris disks. Given this issue we carefully examine the alternative explanation, that the detections arise from confusion with IR cirrus and/or background galaxies that are not physically associated with the foreground star. We find that such an explanation is consistent with all of these detections.

  11. Roentgenologic diagnostics of capsular ligament lesions

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, C.J.; Jaeger, M.

    1981-10-01

    The X-ray diagnostic is of obvious importance and relevance in the detection of acute or old capsular ligament lesions of the limb joint. On the one hand it serves as the plain radiograph (roentgenogram without contrast medium) for the assessment of osseous secondary lesions, for the documentation of luxationary positions of the joint partners, and in old capsular ligament lesions for the detection of an already existing arthrosis. On the other hand the X-ray images are of main importance, which are made from the hand-held limb in order to permit a comparison of the two sides, and which beyond the clinical detection of a joint instability indicate the extent and the direction of this instability and which also document it, and which allow in adolescents to recognize a separation of the epiphysis as an alternative to the capsular ligament rupture. Only in particular cases arthrography can provide some additional information, so for example in the case of an isolated syndesmosis rupture, ruptures of the rosette of the rotator muscle or of a damaged triangular disk in the hand. Angiography is only required in cases of traumatic luxations of the knee in order to exclude an intimal lesion of the popliteal artery.

  12. Ghost cell lesions

    Directory of Open Access Journals (Sweden)

    E Rajesh

    2015-01-01

    Full Text Available Ghost cells have been a controversy for a long time. Ghost cell is a swollen/enlarged epithelial cell with eosnophilic cytoplasm, but without a nucleus. In routine H and E staining these cells give a shadowy appearance. Hence these cells are also called as shadow cells or translucent cells. The appearance of these cells varies from lesion to lesion involving odontogenic and nonodontogenic lesions. This article review about the origin, nature and significance of ghost cells in different neoplasms.

  13. Use of orthopedic shoes in patients with degenerative disorders of the foot

    NARCIS (Netherlands)

    Jannink, Michiel J.; IJzerman, Maarten J.; Groothuis-Oudshoorn, Karin; Stewart, Roy E.; Groothoff, Johan W.; Lankhorst, Gustaaf J.

    2005-01-01

    Objectives: To study the actual use of orthopedic shoes by patients with degenerative foot disorders and to identify factors associated with use and nonuse, based on the parameters of the International Organization for Standardization definition of usability: effectiveness, efficiency, satisfaction,

  14. Management of degenerative rotator cuff tears: a review and treatment strategy

    Science.gov (United States)

    2012-01-01

    The aim of this review was to present an over view of degenerative rotator cuff tears and a suggested management protocol based upon current evidence. Degenerative rotator cuff tears are common and are a major cause of pain and shoulder dysfunction. The management of these tears is controversial, as to whether they should be managed non-operatively or operatively. In addition when operative intervention is undertaken, there is question as to what technique of repair should be used. This review describes the epidemiology and natural history of degenerative rotator cuff tears. The management options, and the evidence to support these, are reviewed. We also present our preferred management protocol and method, if applicable, for surgical fixation of degenerative rotator cuff tears. PMID:23241147

  15. Echocardiographic Follow-up of Robotic Mitral Valve Repair for Mitral Regurgitation due to Degenerative Disease

    Directory of Open Access Journals (Sweden)

    Yao Wang

    2016-01-01

    Conclusion: Robotic MV repair for MR due to degenerative disease is associated with a low rate of recurrent MR, and a significant improvement in MR grade, LAD, and LVEDD, but a significant decrease in LVEF at echocardiographic follow-up.

  16. 78 FR 36305 - Proposed Information Collection (Non-Degenerative Arthritis (Including Inflammatory, Autoimmune...

    Science.gov (United States)

    2013-06-17

    ... AFFAIRS Proposed Information Collection (Non-Degenerative Arthritis (Including Inflammatory, Autoimmune... Arthritis (including inflammatory, autoimmune, crystalline and infectious arthritis) and Dysbaric... inflammatory, autoimmune, crystalline and infectious arthritis) and Dysbaric Osteonecrosis Disability...

  17. Lesion activity assessment

    DEFF Research Database (Denmark)

    Ekstrand, K R; Zero, D T; Martignon, S

    2009-01-01

    in response to cariogenic plaque as well as lesion arrest. Based on this understanding, different clinical scoring systems have been developed to assess the severity/depth and activity of lesions. A recent system has been devised by the International Caries Detection and Assessment System Committee...... the activity of primary coronal and root lesions reliably and accurately at one examination by using the combined information obtained from a range of indicators--such as visual appearance, location of the lesion, tactile sensation during probing and gingival health....

  18. When dialogue fails. Music therapy with elderly with neurological degenerative diseases

    DEFF Research Database (Denmark)

    Wigram, Anthony Lewis

    2004-01-01

    When dialogue fails. Music therapy with elderly with neurological degenerative diseases. In persons suffering from neurological degenerative diseases we often see the following symptoms: difficulties in remembering, concentrating, perceiving input, and controlling and timing movements. Normal every...... interaction with others means that psychosocial needs are not met, and this leads to secondary symptoms of the neurological degeneration. Secondary symptoms might be expressed as repetitive behaviour, catastrophic reactions and situationally inappropriate behaviour. In a music therapeutical setting...

  19. Herniated Disk in the Lower Back

    Science.gov (United States)

    ... two components: Healthy intervertebral disk (cross- section view). • Annulus fibrosus. This is the tough, flexible outer ring ... the Lower Back cont. Surgical Treatment Only a small percentage of patients with lumbar disk herniations require ...

  20. Frying process in the relation fat/degenerative diseases.

    Directory of Open Access Journals (Sweden)

    Varela, G.

    1998-08-01

    Full Text Available Among the various components of the diet, fat receives very dose attention because of its relationship to several chronic degenerative diseases (CDD. Currently most of the available information on these relationships is derived from epidemiologic or experimental studies in which lipid intake is calculated using food composition tables. In most of these tables the quoted lipid content is that of raw food, whereas most foods are usually consumed only after being subjected to several culinary processes. Often there is no indication of the type of fat used in food processing in general or in frying in particular. But as it known, in the course of these processes the lipid content undergoes important qualitative and quantitative changes and not keeping them in mind may be the underlying cause of the difficulties an the confounding results in studies trying to establish the relationship between lipid intake an health. In the Mediterranean diet, about 50% of total dietary fat is derived not from the food itself but from the cooking fat, of which only a small fraction is eaten raw (as dressings and the greatest proportion is used in thermal culinary processes, mainly deep-frying. The scientific study of the process whereby fat penetrates into fried foods has shown the benefits of this cooking method. If the process is correctly carried out, the amount of fat ingested with fried foodstuffs is not greater than when other procedures involving fat are used (for example, sautening, stewing or canning in oil. Very schematically deep-frying is a technique that replaces a fraction of the water content of food by cooking fat. Consecuently, the fat composition of the fried lean foods will be the same as that cooking fat. The process is more complex with fatty foods, and there are not great changes in the total quantity of fat in the fried food before and after frying. However, there are notable quality changes and these depend on the concentration gradients

  1. Vortex migration in protoplanetary disks

    CERN Document Server

    Paardekooper, S -J; Papaloizou, J C B

    2010-01-01

    We consider the radial migration of vortices in two-dimensional isothermal gaseous disks. We find that a vortex core, orbiting at the local gas velocity, induces velocity perturbations that propagate away from the vortex as density waves. The resulting spiral wave pattern is reminiscent of an embedded planet. There are two main causes for asymmetries in these wakes: geometrical effects tend to favor the outer wave, while a radial vortensity gradient leads to an asymmetric vortex core, which favors the wave at the side that has the lowest density. In the case of asymmetric waves, which we always find except for a disk of constant pressure, there is a net exchange of angular momentum between the vortex and the surrounding disk, which leads to orbital migration of the vortex. Numerical hydrodynamical simulations show that this migration can be very rapid, on a time scale of a few thousand orbits, for vortices with a size comparable to the scale height of the disk. We discuss the possible effects of vortex migrat...

  2. Degenerative changes of the sacroiliac auricular joint surface-validation of influential factors.

    Science.gov (United States)

    Nishi, Keita; Saiki, Kazunobu; Imamura, Takeshi; Okamoto, Keishi; Wakebe, Tetsuaki; Ogami, Keiko; Hasegawa, Takashi; Moriuchi, Takefumi; Sakamoto, Junya; Manabe, Yoshitaka; Tsurumoto, Toshiyuki

    2016-06-24

    The purpose of this study was to clarify the relevance of degenerative changes in the sacroiliac joint (SIJ) and the joints in the lower limb and lumbar spine using age estimation methods. We also examined the shape of the auricular surface to determine the effect of degenerative changes on each joint. A total of 200 iliac auricular surfaces from 100 Japanese male skeletons were examined macroscopically in accordance with conventional methods of age estimation. From the obtained estimated age, we calculated the deflection values, which represented the degree of degenerative changes of the joints. For comparison, we used osteophyte score data of the hip, knee, and zygapophyseal joints in lumbar spines from previous studies which had used the same bone specimens. As a quantitative indicator of auricular surface morphology, we defined the constriction ratio (CR) of the auricular surface and compared the CR values obtained with various measured values. Degenerative changes in the SIJ were positively correlated with those in both the hip joint and zygapophyseal joint, but a correlation with knee joints was found only on the left side. In skeletons from individuals aged ≥60 years as time of death, the CR was significantly different between the group with high scores and those with low scores in both the hip and sacroiliac joints. It has been suggested that degenerative changes in SIJs interact with those in the hip joint and zygapophyseal joint. In addition, the shape of the auricular surface may also be a relevant factor for degenerative changes in these joints.

  3. Scaphocapitolunate arthrodesis and radial styloidectomy for posttraumatic degenerative wrist disease.

    Science.gov (United States)

    Klausmeyer, Melissa A; Fernandez, Diego L; Caloia, Martin

    2012-08-01

    Long-standing scaphoid nonunion, scaphoid malunion, and chronic scapholunate dissociation result in malalignment of the carpal bones, progressive carpal collapse, instability, and osteoarthritis of the wrist. The most commonly used procedures to treat scaphoid nonunion advanced collapse (SNAC) and scapholunate advanced collapse (SLAC) wrists are the four-corner fusion (4CF) and the proximal row carpectomy (PRC). The purpose of this study was to evaluate the clinical outcome of a different treatment modality: radial styloidectomy and scaphocapitolunate (SCL) arthrodesis. This treatment option is chosen in an effort to maintain the joint contact surface and load transmission across the radiocarpal joint. We conducted a retrospective review of 20 patients (average age 62 years, range: 27 to 75 years) treated from 1994 to 2010. Seven patients were treated for SNAC, 12 patients for SLAC wrists, and 1 for degenerative joint disease following a transscapho-transcapitate perilunar dislocation. Sixteen patients had Herbert screw fixation, and four had Spider plate fixation. All patients had autologous bone graft used for the arthrodesis. The mean follow-up was 4.6 years (range: 2 to 9.6 years). Patients were evaluated clinically and radiographically. Nineteen of 20 arthrodeses healed on an average of 9.6 weeks. One patient was reoperated 8 months after the initial operation with salvage of the SCL arthrodesis with a spider plate with an adequate result. The mean active flexion-extension arc was 70 degrees and the radioulnar deviation arc was 23 degrees. Pain decreased in all patients, 13 of whom were pain free postoperatively. The average postoperative disabilities of arm, shoulder, and hand score was 24. Radiographically, neither radiolunate nor radioscaphoid arthritis was noted on follow-up. SCL arthrodesis with radial styloidectomy resulted in an adequate residual range of motion and pain relief. This method preserves the normal ulnar sided joints of the carpus and

  4. Defining the inherent stability of degenerative spondylolisthesis: a systematic review.

    Science.gov (United States)

    Simmonds, Andrea M; Rampersaud, Y Raja; Dvorak, Marcel F; Dea, Nicolas; Melnyk, Angela D; Fisher, Charles G

    2015-08-01

    OBJECT A range of surgical options exists for the treatment of degenerative lumbar spondylolisthesis (DLS). The chosen technique inherently depends on the stability of the DLS. Despite a substantial body of literature dedicated to the outcome analysis of numerous DLS procedures, no consensus has been reached on defining or classifying the disorder with respect to stability or the role that instability should play in a treatment algorithm. The purpose of this study was to define grades of stability and to develop a guide for deciding on the optimal approach in surgically managing patients with DLS. METHODS The authors conducted a qualitative systematic review of clinical or biomechanical analyses evaluating the stability of and surgical outcomes for DLS for the period from 1990 to 2013. Research focused on nondegenerative forms of spondylolisthesis or spinal stenosis without associated DLS was excluded. The primary extracted results were clinical and radiographic parameters indicative of DLS instability. RESULTS The following preoperative parameters are predictors of stability in DLS: restabilization signs (disc height loss, osteophyte formation, vertebral endplate sclerosis, and ligament ossification), no disc angle change or less than 3 mm of translation on dynamic radiographs, and the absence of low-back pain. The validity and magnitude of each parameter's contribution can only be determined through appropriately powered prospective evaluation in the future. Identifying these parameters has allowed for the creation of a preliminary DLS instability classification (DSIC) scheme based on the preoperative assessment of DLS stability. CONCLUSIONS Spinal stability is an important factor to consider in the evaluation and treatment of patients with DLS. Qualitative assessment of the best available evidence revealed clinical and radiographic parameters for the creation of the DSIC, a decision aid to help surgeons develop a method of preoperative evaluation to better

  5. Degenerative effects in rat eyes after experimental ocular hypertension

    Directory of Open Access Journals (Sweden)

    G. Scarsella

    2012-10-01

    Full Text Available This study was used to evaluate the degenerative effects on the retina and eye-cup sections after experimental induction of acute ocular hypertension on animal models. In particular, vascular events were directly focused in this research in order to assess the vascular remodeling after transient ocular hypertension on rat models. After local anaesthesia by administration of eye drops of 0.4% oxibuprocaine, 16 male adult Wistar rats were injected in the anterior chamber of the right eye with 15 µL of methylcellulose (MTC 2% in physiological solution. The morphology and the vessels of the retina and eye-cup sections were examined in animals sacrificed 72 h after induction of ocular hypertension. In retinal fluorescein angiographies (FAGs, by means of fluorescein isothiocyanate-coniugated dextran (FITC, the radial venules showed enlargements and increased branching, while the arterioles appeared focally thickened. The length and size of actually perfused vessels appeared increased in the whole superficial plexus. In eye-cup sections of MTC-injected animals, in deep plexus and connecting layer there was a bigger increase of vessels than in controls. Moreover, the immunolocalization of astrocytic marker glial fibrillary acidic protein (GFAP revealed its increased expression in internal limiting membrane and ganglion cell layer, as well as its presence in Müller cells. Finally, the pro-angiogenic factor vascular endothelial growth factor (VEGF was found to be especially expressed by neurones of ganglion cell layer, both in control and in MTC-injected eyes. The data obtained in this experimental model on the interactions among glia, vessels and neurons should be useful to evaluate if also in glaucomatous patients the activation of vessel-adjacent glial cells might play key roles in following neuronal dysfunction.

  6. Management of degenerative cervical myelopathy – An update

    Directory of Open Access Journals (Sweden)

    ANDREI F. JOAQUIM

    Full Text Available SUMMARY Introduction Degenerative cervical myelopathy (DCM is the most common cause of spinal cord dysfunction in adult patients. Patients generally present with a slow, progressive neurological decline or a stepwise deterioration pattern. In this paper, we discuss the most important factors involved in the management of DCM, including a discussion about the surgical approaches. Method The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives. Results Although the diagnosis is clinical, magnetic resonance imaging (MRI is the study of choice to confirm stenosis and also to exclude the differential diagnosis. The severity the clinical symptoms of DCM are evaluated by different scales, but the modified Japanese Orthopedic Association (mJOA and the Nürick scale are probably the most commonly used. Spontaneous clinical improvement is rare and surgery is the main treatment form in an attempt to prevent further neurological deterioration and, potentially, to provide some improvement in symptoms and function. Anterior, posterior or combined cervical approaches are used to decompress the spinal cord, with adjunctive fusion being commonly performed. The choice of one approach over the other depends on patient characteristics (such as number of involved levels, site of compression, cervical alignment, previous surgeries, bone quality, presence of instability, among others as well as surgeon preference and experience. Conclusion Spine surgeons must understand the advantages and disadvantages of all surgical techniques to choose the best procedure for their patients. Further comparative studies are necessary to establish the superiority of one approach over the other when multiple options are available.

  7. A clinico-radiologic study of the various lesions in the oral and maxillofacial region of children

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Soon Chul; Lee, Young Ho; Park, Tae Won; You, Dong Soo [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    1995-08-15

    Two thousand-two hundred-forty-three cases of various lesions of the oral and maxillofacial region in children under 16 years of age were reviewed. The lesions were classified by 10 groups, osteomyelitis, cysts, benign tumors, malignant tumors, fibro-osseous lesions, developmental disturbances, antral lesions, TMJ lesions, salivary gland lesions, and other lesions. The obtained results were as follows; 1. Developmental disturbances, especially cleft alveolus and palate, was the most common lesions (25.7%), followed by cysts (22.5%), antral lesions (12.7%), benign tumors (11.9%) and osteomyelitis (9.3%). 2. With the time, the incidence of osteomyelitis and malignant tumors has been decreased, but that of developmental disturbances, cysts and antral lesions has been increased. 3. The sex distribution was relatively equal for the entire series, with male predominence in cysts, malignant tumors, developmental disturbances and salivary gland lesions and with female predominance in TMJ lesions. 4. Children with malignant tumors and osteomyelitis were somewhat younger and those with TMJ lesions were somewhat older. 5. Heading the list of each group except osteomyelitis was dentigerous cyst, odontoma, malignant lymphoma, fibrous dysplasia, cleft alveolus and palate, inflammatory change, degenerative change of condylar process, sialolithiasis and simple bone cyst respectively.

  8. The Structure of Brown Dwarf Circumstellar Disks

    OpenAIRE

    Walker, Christina; Wood, Kenneth; Lada, C. J.; Robitaille, Thomas; Bjorkman, J. E.; Whitney, Barbara

    2004-01-01

    We present synthetic spectra for circumstellar disks that are heated by radiation from a central brown dwarf. Under the assumption of vertical hydrostatic equilibrium, our models yield scaleheights for brown dwarf disks in excess of three times those derived for classical T Tauri (CTTS) disks. If the near-IR excess emission observed from brown dwarfs is indeed due to circumstellar disks, then the large scaleheights we find could have a significant impact on the optical and near-IR detectabili...

  9. Optimization of the Processing of Mo Disks

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States); Stepinski, Dominique [Argonne National Lab. (ANL), Argonne, IL (United States); Makarashvili, Vakhtang [Argonne National Lab. (ANL), Argonne, IL (United States); Harvey, James [NorthStar Medical Technologies, LLC, Madison, WI (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-01-01

    The objective of this work is to decrease the processing time for irradiated disks of enriched Mo for the production of 99Mo. Results are given for the dissolution of nonirradiated Mo disks, optimization of the process for large-scale dissolution of sintered disks, optimization of the removal of the main side products (Zr and Nb) from dissolved targets, and dissolution of irradiated Mo disks.

  10. Fabrication of Large YBCO Superconducting Disks

    Science.gov (United States)

    Koczor, Ronald J.; Noever, David A.; Robertson, Glen A.

    1999-01-01

    We have undertaken fabrication of large bulk items to develop a repeatable process and to provide test articles in laboratory experiments investigating reported coupling of electromagnetic fields with the local gravity field in the presence of rotating superconducting disks. A successful process was developed which resulted in fabrication of 30 cm diameter annular disks. The disks were fabricated of the superconductor YBa2Cu3O(7-x). Various material parameters of the disks were measured.

  11. PSOCT studies of intervertebral disk

    Science.gov (United States)

    Matcher, Stephen J.; Winlove, Peter C.; Gangnus, Sergey V.

    2004-07-01

    Polarization-sensitive optical coherence tomography (PSOCT) is an emerging optical imaging technique that is sensitive to the birefringence properties of tissues. It thus has applications in studying the large-scale ordering of collagen fibers within connective tissues. This ordering not only provides useful insights into the relationship between structure and function for various anatomical structures but also is an indicator of pathology. Intervertebral disk is an elastic tissue of the spine and possesses a 3-D collagen structure well suited to study using PSOCT. Since the outer layer of the disk has a lamellar structure with collagen fibers oriented in a trellis-like arrangement between lamellae, the birefringence fast-axis shows pronounced variations with depth, on a spatial scale of about 100 μm. The lamellar thickness varies with age and possibly with disease. We have used a polarisation-sensitive optical coherence tomography system to measure the birefringence properties of freshly excised, hydrated bovine caudal intervertebral disk and compared this with equine flexor tendon. Our results clearly demonstrate the ability of PSOCT to detect the outer three lamellae, down to a depth of at least 700 μm, via discontinuities in the depth-resolved retardance. We have applied a simple semi-empirical model based on Jones calculus to quantify the variation in the fast-axis orientation with depth. Our data and modeling is in broad agreement with previous studies using x-ray diffraction and polarization microscopy applied to histological sections of dehydrated disk. Our results imply that PSOCT may prove a useful tool to study collagen organisation within intervertebral disk in vitro and possibly in vivo and its variation with age and disease.

  12. The Evolutionary State of Anemic Circumstellar Disks and the Primordial-to-Debris Disk Transition

    CERN Document Server

    Currie, Thayne

    2008-01-01

    We investigate the evolution of $\\sim$ 3 Myr-old MIPS-detected circumstellar disks in IC 348 that may be in an intermediate stage between primordial, optically-thick disks of gas/dust and debris disks characteristic of the final stages of planet formation. We demonstrate that these \\textit{anemic} disks are not a homogenous class of objects corresponding to a unique evolutionary state. Rather, such disks around early (B/A) spectral type stars are most likely warm, terrestrial zone debris disks; MIPS-detected anemic disks around later (M) stars are likely \\textit{evolved primordial disks} such as transition disks in their mid-IR colors, accretion signatures, and disk luminosities. Anemic disks surrounding G and K stars contain both populations. The difference in evolutionary states between anemic disks surrounding early type vs. late-type stars is consistent with a mass-dependent evolution of circumstellar disks from the primordial disk phase through the debris disk phase. Specifically, disks characteristicall...

  13. Degenerative lesion of the vertebral column: a new view of the disease, approaches to therapy (the authors' own findings

    Directory of Open Access Journals (Sweden)

    N A Shostak

    2008-01-01

    Full Text Available An open-labeled randomized study of the efficacy and safety of Piascledine-300 in combination with nonsteroidal anti-inflammatory drugs (NSAIDs versus the latter was conducted in 2 matched groups of patients with lower back pain associated with spondylarthrosis. During combined therapy using Piascledine, there was a reduction in the pain syndrome particularly with the longer administration of the drug. The use of Piascledine in spondylarthrosis showed its clinical efficacy in 89,2% of patients: the indices of lumbago substantially reduced and spinal function improved, which was associated with the good tolerability of the drug.

  14. NASA Lunar and Meteorite Sample Disk Program

    Science.gov (United States)

    Foxworth, Suzanne

    2017-01-01

    The Lunar and Meteorite Sample Disk Program is designed for K-12 classroom educators who work in K-12 schools, museums, libraries, or planetariums. Educators have to be certified to borrow the Lunar and Meteorite Sample Disks by attending a NASA Certification Workshop provided by a NASA Authorized Sample Disk Certifier.

  15. Air-lubrication of magnetic disk sliders

    Science.gov (United States)

    Dreßler, B.; Graichen, K.; Bärwolff, G.; Jehring, L.; Seifert, G.

    1993-03-01

    Steady-state and dynamic flying of a self-acting magnetic disk slider over a hard disk are considered. Some tasks for computations are formulated and the possibilities of developed numerical codes are illustrated. Numerical results of dynamic flying over a disk surface with an obstacle are in agreement with experimental data.

  16. Growing and moving planets in disks

    NARCIS (Netherlands)

    Paardekooper, Sijme-Jan

    2006-01-01

    Planets form in disks that are commonly found around young stars. The intimate relationship that exists between planet and disk can account for a lot of the exotic extrasolar planetary systems known today. In this thesis we explore disk-planet interaction using numerical hydrodynamical simulations.

  17. Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability

    CERN Document Server

    Szulágyi, J; Quinn, T

    2016-01-01

    Circumplanetary disks can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary disks for both formation scenarios, using as similar initial conditions as possible to unveil possible intrinsic differences in the circumplanetary disk mass and temperature between the two formation mechanisms. We found that the circumplanetary disks mass linearly scales with the circumstellar disk mass. Therefore, in an equally massive protoplanetary disk, the circumplanetary disks formed in the disk instability model can be only a factor of eight more massive than their core-accretion counterparts. On the other hand, the bulk circumplanetary disk temperature differs by more than an order of magnitude between the two cases. The subdisks around planets formed by gravitational instability have a characteristic temperature below 100 K, while the core accretion circumplanetary disks a...

  18. Kinematic Dynamo In Turbulent Circumstellar Disks

    Science.gov (United States)

    Stepinski, T.

    1993-01-01

    Many circumstellar disks associated with objects ranging from protoplanetary nebulae, to accretion disks around compact stars allow for the generation of magnetic fields by an (alpha)omega dynamo. We have applied kinematic dynamo formalism to geometrically thin accretion disks. We calculate, in the framework of an adiabatic approximation, the normal mode solutions for dynamos operating in disks around compact stars. We then describe the criteria for a viable dynamo in protoplanetary nebulae, and discuss the particular features that make accretion disk dynamos different from planetary, stellar, and galactic dynamos.

  19. Intraosseous osteolytic lesions

    Energy Technology Data Exchange (ETDEWEB)

    Adler, C.P.; Wenz, W.

    1981-10-01

    Any pathological damage occurring in a bone will produce either an osteolytic or osteosclerotic lesion which can be seen in the macroscopic specimen as well as in the roentgenogram. Various bone lesions may lead to local destructions of the bone. An osteoma or osteoplastic osteosarcoma produces an osteosclerotic lesion showing a dense mass in the roentgenogram; a chondroblastoma or an osteoclastoma, on the other hand, induces an osteolytic focal lesion. This paper presents examples of different osteolytic lesions of the humerus. An osteolytic lesion seen in the roentgenogram may be either produced by an underlying non-ossifying fibroma of the bone, by fibrous dysplasia, osteomyelitis or Ewing's sarcoma. Differential diagnostic considerations based on the radiological picture include eosinophilic bone granuloma, juvenile or aneurysmal bone cyst, multiple myeloma or bone metastases. Serious differential diagnostic problems may be involved in case of osteolytic lesions occurring in the humerus. Cases of this type involving complications have been reported and include the presence of an teleangiectatic osteosarcoma as well as that of a hemangiosarcoma of the bone.

  20. Accretion disks in Algols: progenitors and evolution

    CERN Document Server

    Van Rensbergen, W

    2016-01-01

    There are only a few Algols with measured accretion disk parameters. These measurements provide additional constraints for tracing the origin of individual systems, narrowing down the initial parameter space. We investigate the origin and evolution of 6 Algol systems with accretion disks to find the initial parameters and evolutionary constraints for them. With a modified binary evolution code, series of close binary evolution are calculated to obtain the best match for observed individual systems. Initial parameters for 6 Algol systems with accretion disks were determined matching both the present system parameters and the observed disk characteristics. When RLOF starts during core hydrogen burning of the donor, the disk lifetime was found to be short. The disk luminosity is comparable to the luminosity of the gainer during a large fraction of the disk lifetime.

  1. The Evolving Structure of Galactic Disks

    CERN Document Server

    Martel, H; McGee, S; Gibson, B; Kawata, D; Martel, Hugo; Brook, Chris; Gee, Sean Mc; Gibson, Brad

    2005-01-01

    Observations suggest that the structural parameters of disk galaxies have not changed greatly since redshift 1. We examine whether these observations are consistent with a cosmology in which structures form hierarchically. We use SPH/N-body galaxy-scale simulations to simulate the formation and evolution of Milky-Way-like disk galaxies by fragmentation, followed by hierarchical merging. The simulated galaxies have a thick disk, that forms in a period of chaotic merging at high redshift, during which a large amount of alpha-elements are produced, and a thin disk, that forms later and has a higher metallicity. Our simulated disks settle down quickly and do not evolve much since redshift z~1, mostly because no major mergers take place between z=1 and z=0. During this period, the disk radius increases (inside-out growth) while its thickness remains constant. These results are consistent with observations of disk galaxies at low and high redshift.

  2. Why are some galaxy disks extremely thin?

    CERN Document Server

    Banerjee, Arunima

    2012-01-01

    Some low surface brightness galaxies are known to have extremely thin stellar disks with the vertical to planar axes ratio 0.1 or less, often referred to as superthin disks. Although their existence is known for over three decades, the physical origin for the thin distribution is not understood. We model the stellar thickness for a two-component (gravitationally coupled stars and gas) disk embedded in a dark matter halo, for a superthin galaxy UGC 7321 which has a dense, compact halo, and compare with a typical dwarf galaxy HoII which has a non-compact halo. We show that while the presence of gas does constrain the disk thickness, it is the compact dark matter halo which plays the decisive role in determining the superthin disk distribution in low-mass disks. Thus the compact dark matter halo significantly affects the disk structure and this could be important for the early evolution of galaxies.

  3. Magnetic interchange instability of accretion disks

    Science.gov (United States)

    Kaisig, M.; Tajima, T.; Lovelace, R. V. E.

    1992-01-01

    The nonlinear evolution of the magnetic interchange or buoyancy instability of a differentially rotating disk threaded by an ordered vertical magnetic field is investigated. A 2D ideal fluid in the equatorial plane of a central mass in the corotating frame of reference is considered as a model for the disk. If the rotation rate of the disk is Keplerian, the disk is found to be stable. If the vertical magnetic field is sufficiently strong, and the field strength decreases with distance from the central object, and thus the rotation of the disk deviates from Keplerian, if is found that an instability develops. The magnetic flux and disk matter expand outward in certain ranges of azimuth, while disk matter with less magnetic flux moves inward over the remaining range of azimuth, showing a characteristic development of an interchange instability.

  4. Dust Evolution in Protoplanetary Disks

    CERN Document Server

    Testi, Leonardo; Ricci, Luca; Andrews, Sean; Blum, Juergen; Carpenter, John; Dominik, Carsten; Isella, Andrea; Natta, Antonella; Williams, Jonathan; Wilner, David

    2014-01-01

    (abridged) In the core accretion scenario for the formation of planetary rocky cores, the first step toward planet formation is the growth of dust grains into larger and larger aggregates and eventually planetesimals. Although dust grains are thought to grow from the submicron sizes typical of interstellar dust to micron size particles in the dense regions of molecular clouds and cores, the growth from micron size particles to pebbles and kilometre size bodies must occur in protoplanetary disks. This step in the formation of planetary systems is the last stage of solids evolution that can be observed directly in young extrasolar systems. In this chapter we review the constraints on the physics of grain-grain collisions as they have emerged from laboratory experiments and numerical computations. We then review the current theoretical understanding of the global processes governing the evolution of solids in protoplanetary disks, including dust settling, growth, and radial transport. The predicted observational...

  5. Secular evolution of disk galaxies

    CERN Document Server

    Combes, F

    2008-01-01

    Galaxy disks evolve through angular momentum transfers between sub-components, like gas, stars, or dark matter halos, through non axi-symmetric instabilities. The speed of this evolution is boosted in presence of a large fraction of cold and dissipative gas component. When the visible matter dominates over the whole disk, angular momentum is exchanged between gas and stars only. The gas is driven towards the center by bars, stalled transiently in resonance rings, and driven further by embedded bars, which it contributes to destroy. From a small-scale molecular torus, the gas can then inflow from viscous torques, dynamical friction, or m=1 perturbations. In the weakened bar phases, multiple-speed spiral patterns can develop and help the galaxy to accrete external gas flowing from cosmic filaments. The various phases of secular evolution are illustrated by numerical simulations.

  6. Mechanics of Forming Ring Disks

    Directory of Open Access Journals (Sweden)

    Avakyan R.M.

    2010-12-01

    Full Text Available The analysis of forming ring disk of constant thickness in conditions of large plastic deformations taking into account the interconnected change of effective strain and deformation hardening is carried out. The analytical dependences characterizing the relative size of plastic area are obtained. The interrelation between the initial and final form of a product is established at maximum possible size of internal pressure.

  7. Parallel Readout of Optical Disks

    Science.gov (United States)

    1992-08-01

    27, 2987-2992 (1988). 11. T. Yatagai, J. G. Camacho-Basilio, and H. Onda , "Recording of Computer-Generated Holograms on an Optical Disk Master...Multivariate Observations," Proceedings of the Fifth Berkeley Symposium on Math. Stat. and Prob I., L. M. LeCam and J. Neyman, eds. (University of...California Press, Berkeley and Los Angeles California, 1967), pp. 281-297. [9] R. Duda and P Hart, "Pattern Classification and Scene Analysis," (John

  8. A Supersymmetric Dark Disk Universe

    CERN Document Server

    Fischler, Willy; Tangarife, Walter

    2014-01-01

    We present a model of partially interacting dark matter (PIDM) within the framework of supersymmetry with gauge mediated symmetry breaking. Dark sector atoms are produced through Affleck-Dine baryogenesis in the dark sector while avoiding the production of Q-ball relics. We discuss the astrophysical constraints relevant for this model and the possibility of dark galactic disk formation. In addition, jet emission from rotating black holes is discussed in the context of this class of models.

  9. A Pulsar and a Disk

    Science.gov (United States)

    Kohler, Susanna

    2016-07-01

    Recent, unusual X-ray observations from our galactic neighbor, the Small Magellanic Cloud, have led to an interesting model for SXP 214, a pulsar in a binary star system.Artists illustration of the magnetic field lines of a pulsar, a highly magnetized, rotating neutron star. [NASA]An Intriguing BinaryAn X-ray pulsar is a magnetized, rotating neutron star in a binary system with a stellar companion. Material is fed from the companion onto the neutron star, channeled by the objects magnetic fields onto a hotspot thats millions of degrees. This hotspot rotating past our line of sight is what produces the pulsations that we observe from X-ray pulsars.Located in the Small Magellanic Cloud, SXP 214 is a transient X-ray pulsar in a binary with a Be-type star. This star is spinning so quickly that material is thrown off of it to form a circumstellar disk.Recently, a team of authors led by JaeSub Hong (Harvard-Smithsonian Center for Astrophysics) have presented new Chandra X-ray observations of SXP 214, tracking it for 50 ks (~14 hours) in January 2013. These observations reveal some very unexpected behavior for this pulsar.X-ray PuzzleThe energy distribution of the X-ray emission from SXP 214 over time. Dark shades or blue colors indicate high counts, and light shades or yellow colors indicate low counts. Lower-energy X-ray emission appeared only later, after about 20 ks. [Hong et al. 2016]Three interesting pieces of information came from the Chandra observations:SXP 214s rotation period was measured to be 211.5 s an increase in the spin rate since the discovery measurement of a 214-second period. Pulsars usually spin down as they lose angular momentum over time so what caused this one to spin up?Its overall X-ray luminosity steadily increased over the 50 ks of observations.Its spectrum became gradually softer (lower energy) over time; in the first 20 ks, the spectrum only consisted of hard X-ray photons above 3 keV, but after 20 ks, softer X-ray photons below 2 ke

  10. Regression of lumbar disk herniation

    Directory of Open Access Journals (Sweden)

    G. Yu Evzikov

    2015-01-01

    Full Text Available Compression of the spinal nerve root, giving rise to pain and sensory and motor disorders in the area of its innervation is the most vivid manifestation of herniated intervertebral disk. Different treatment modalities, including neurosurgery, for evolving these conditions are discussed. There has been recent evidence that spontaneous regression of disk herniation can regress. The paper describes a female patient with large lateralized disc extrusion that has caused compression of the nerve root S1, leading to obvious myotonic and radicular syndrome. Magnetic resonance imaging has shown that the clinical manifestations of discogenic radiculopathy, as well myotonic syndrome and morphological changes completely regressed 8 months later. The likely mechanism is inflammation-induced resorption of a large herniated disk fragment, which agrees with the data available in the literature. A decision to perform neurosurgery for which the patient had indications was made during her first consultation. After regression of discogenic radiculopathy, there was only moderate pain caused by musculoskeletal diseases (facet syndrome, piriformis syndrome that were successfully eliminated by minimally invasive techniques. 

  11. Heating and Cooling Protostellar Disks

    CERN Document Server

    Hirose, S

    2011-01-01

    We examine heating and cooling in protostellar disks using 3-D radiation-MHD calculations of a patch of the Solar nebula at 1 AU, employing the shearing-box and flux-limited radiation diffusion approximations. The disk atmosphere is ionized by stellar X-rays, well-coupled to magnetic fields, and sustains a turbulent accretion flow driven by magneto-rotational instability, while the interior is resistive and magnetically dead. The turbulent layers heat by absorbing the light from the central star and by dissipating the magnetic fields. They are optically-thin to their own radiation and cool inefficiently. The optically-thick interior in contrast is heated only weakly, by re-emission from the atmosphere. The interior is colder than a classical viscous model, and isothermal. The magnetic fields support an extended atmosphere that absorbs the starlight 1.5 times higher than the hydrostatic viscous model. The disk thickness thus measures not the internal temperature, but the magnetic field strength. Fluctuations i...

  12. Disk Detective Follow-Up Program

    Science.gov (United States)

    Kuchner, Marc

    As new data on exoplanets and young stellar associations arrive, we will want to know: which of these planetary systems and young stars have circumstellar disks? The vast allsky database of 747 million infrared sources from NASA's Wide-field Infrared Survey Explorer (WISE) mission can supply answers. WISE is a discovery tool intended to find targets for JWST, sensitive enough to detect circumstellar disks as far away as 3000 light years. The vast WISE archive already serves us as a roadmap to guide exoplanet searches, provide information on disk properties as new planets are discovered, and teach us about the many hotly debated connections between disks and exoplanets. However, because of the challenges of utilizing the WISE data, this resource remains underutilized as a tool for disk and planet hunters. Attempts to use WISE to find disks around Kepler planet hosts were nearly scuttled by confusion noise. Moreover, since most of the stars with WISE infrared excesses were too red for Hipparcos photometry, most of the disks sensed by WISE remain obscure, orbiting stars unlisted in the usual star databases. To remedy the confusion noise problem, we have begun a massive project to scour the WISE data archive for new circumstellar disks. The Disk Detective project (Kuchner et al. 2016) engages layperson volunteers to examine images from WISE, NASA's Two Micron All-Sky Survey (2MASS) and optical surveys to search for new circumstellar disk candidates via the citizen science website DiskDetective.org. Fueled by the efforts of > 28,000 citizen scientists, Disk Detective is the largest survey for debris disks with WISE. It has already uncovered 4000 disk candidates worthy of follow-up. However, most host stars of the new Disk Detective disk candidates have no known spectral type or distance, especially those with red colors: K and M stars and Young Stellar Objects. Others require further observations to check for false positives. The Disk Detective project is supported by

  13. Common conjunctival lesions

    African Journals Online (AJOL)

    ocular appearance. is discussion does not attempt to classify lesions, but only highlights ... magnifying glass. Examine what you can see and evert the upper ... look at the cornea and feel for pre-auricular and submandibular lymph nodes.

  14. Oropharynx lesion biopsy

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003850.htm Oropharynx lesion biopsy To use the sharing features on this ... Department of Otolaryngology - Head and Neck Surgery, The University of Texas Medical School at Houston, Houston, TX. ...

  15. Managing Carious Lesions

    DEFF Research Database (Denmark)

    Schwendicke, F; Frencken, J E; Bjørndal, L

    2016-01-01

    caries and control activity of existing cavitated lesions to preserve hard tissues and retain teeth long-term. Entering the restorative cycle should be avoided as far as possible. Controlling the disease in cavitated carious lesions should be attempted using methods which are aimed at biofilm removal...... or control first. Only when cavitated carious lesions either are noncleansable or can no longer be sealed are restorative interventions indicated. When a restoration is indicated, the priorities are as follows: preserving healthy and remineralizable tissue, achieving a restorative seal, maintaining pulpal...... health, and maximizing restoration success. Carious tissue is removed purely to create conditions for long-lasting restorations. Bacterially contaminated or demineralized tissues close to the pulp do not need to be removed. In deeper lesions in teeth with sensible (vital) pulps, preserving pulpal health...

  16. Three Different Methods in Deformity Correction of Degenerative Flat Back: A Single Surgeon's Experience with 64 Consecutive Cases

    OpenAIRE

    Kim, Ki-Tack; Lee, Sang-Hun; Lee, Jung-Hee; Kang, Kyung-Jung; Lee, Jung-Suk; Son, Eun-Seok

    2015-01-01

    Study Design Retrospective study. Purpose To evaluate the radiological and clinical results of three different methods in the deformity correction of a degenerative flat back. Overview of Literature There are no comparative studies about different procedures in the treatment of degenerative flat back. Methods Sixty-four patients who consecutively underwent corrective surgery for degenerative flat back were reviewed. The operations were performed by three different methods: posterior-only (gro...

  17. Connecting the shadows: probing inner disk geometries using shadows in transitional disks

    Science.gov (United States)

    Min, M.; Stolker, T.; Dominik, C.; Benisty, M.

    2017-08-01

    Aims: Shadows in transitional disks are generally interpreted as signs of a misaligned inner disk. This disk is usually beyond the reach of current day high contrast imaging facilities. However, the location and morphology of the shadow features allow us to reconstruct the inner disk geometry. Methods: We derive analytic equations of the locations of the shadow features as a function of the orientation of the inner and outer disk and the height of the outer disk wall. In contrast to previous claims in the literature, we show that the position angle of the line connecting the shadows cannot be directly related to the position angle of the inner disk. Results: We show how the analytic framework derived here can be applied to transitional disks with shadow features. We use estimates of the outer disk height to put constraints on the inner disk orientation. In contrast with the results from Long et al. (2017, ApJ, 838, 62), we derive that for the disk surrounding HD 100453 the analytic estimates and interferometric observations result in a consistent picture of the orientation of the inner disk. Conclusions: The elegant consistency in our analytic framework between observation and theory strongly support both the interpretation of the shadow features as coming from a misaligned inner disk as well as the diagnostic value of near infrared interferometry for inner disk geometry.

  18. Magnetic resonance imaging differential diagnosis of brainstem lesions in children

    Institute of Scientific and Technical Information of China (English)

    Carlo Cosimo Quattrocchi; Yuri Errante; Maria Camilla Rossi Espagnet; Stefania Galassi; Sabino Walter Della Sala; Bruno Bernardi; Giuseppe Fariello; Daniela Longo

    2016-01-01

    Differential diagnosis of brainstem lesions,either isolated or in association with cerebellar and supra-tentorial lesions,can be challenging. Knowledge of the structural organization is crucial for the differential diagnosis and establishment of prognosis of pathologies with involvement of the brainstem. Familiarity with the location of the lesions in the brainstem is essential,especially in the pediatric population. Magnetic resonance imaging(MRI) is the most sensitive and specific imaging technique for diagnosing disorders of the posterior fossa and,particularly,the brainstem. High magnetic static field MRI allows detailed visualization of the morphology,signal intensity and metabolic content of the brainstem nuclei,together with visualization of the normal development and myelination. In this pictorial essay we review the brainstem pathology in pediatric patients and consider the MR imaging patterns that may help the radiologist to differentiate among vascular,toxico-metabolic,infectiveinflammatory,degenerative and neoplastic processes. Helpful MR tips can guide the differential diagnosis: These include the location and morphology of lesions,the brainstem vascularization territories,gray and white matter distribution and tissue selective vulnerability.

  19. Unusual benign breast lesions

    Energy Technology Data Exchange (ETDEWEB)

    Porter, G.J.R. [Nottingham Breast Institute, City Hospital, Hucknall Rd, Nottingham NG5 1PB (United Kingdom)]. E-mail: gporter@ncht.trent.nhs.uk; Evans, A.J. [Nottingham Breast Institute, City Hospital, Hucknall Rd, Nottingham NG5 1PB (United Kingdom); Lee, A.H.S. [Nottingham Breast Institute, City Hospital, Hucknall Rd, Nottingham NG5 1PB (United Kingdom); Hamilton, L.J. [Nottingham Breast Institute, City Hospital, Hucknall Rd, Nottingham NG5 1PB (United Kingdom); James, J.J. [Nottingham Breast Institute, City Hospital, Hucknall Rd, Nottingham NG5 1PB (United Kingdom)

    2006-07-15

    The purpose of this article is to show examples of the radiological (mammography and/or ultrasound) and pathological appearances of unusual benign breast lesions. The conditions covered are granular cell tumours, fibromatosis, nodular fasciitis, myofibroblastomas, haemangiomas, neurofibromas, and leiomyomas. The article includes the first published description of the ultrasound appearance of a myofibroblastoma. Knowledge of these appearances may help confirm or refute radiological-pathological concordance of percutaneous biopsy results during multidisciplinary assessment of these lesions and aid patient management.

  20. Andersson Lesion in Ankylosing Spondylitis

    Directory of Open Access Journals (Sweden)

    Manimegalai N, KrishnanKutty K, Panchapakesa Rajendran C, Rukmangatharajan S, Rajeswari S

    2004-04-01

    Full Text Available Andersson lesions are destructive foci that appear at the discovertebral junction in ankylosingspondylitis. We report three cases of ankylosing spondylitis with such lesions. These lesions simulatean infection and in our country, mimic spinal tuberculosis.

  1. Intervertebral disc degeneration and bone density in degenerative lumbar scoliosis: a comparative study between patients with degenerative lumbar scoliosis and patients with lumbar stenosis

    Institute of Scientific and Technical Information of China (English)

    DING Wen-yuan; YANG Da-long; CAO Lai-zhen; SUN Ya-peng; ZHANG Wei; XU Jia-xin; ZHANG Ying-ze; SHEN Yong

    2011-01-01

    Background Degenerative lumbar scoliosis is common in older patients.Decreased bone density and the degeneration of intervertebral discs are considered to be correlated with degenerative lumbar scoliosis.A means of quantifying the relative signal intensity for degenerative disc disease has not been previously discussed.The purpose of this study was to compare bone mineral density and intervertebral disc degeneration between degenerative lumbar scoliosis and lumbar spinal stenosis patients in a nine-year retrospective study.Methods From January 2001 to August 2010,96 patients with degenerative lumbar scoliosis were retrospectively enrolled and 96 patients with lumbar spinal stenosis were selected as controls.Cobb angle,height of the apical disc and the contiguous disc superiorly and inferiorly on convex and concave sides,the height of the convex and concave side of the apical and the contiguous vertebral body superiorly and inferiorly were measured in the scoliosis group.The height of L2/L3,L3/L4,L4/L5 discs and the height of L2/L4 vertebral body was measured in the control group.The grade of intervertebral disc degeneration was evaluated using T2WI sagittal images in both groups.The bone density of lumbar vertebrae was measured with dual-energy X-ray.Results In scoliosis group,the intervertebral disc height on the convex side was greater than the height on the concave side (P <0.001 ).The vertebral body height on the convex side was greater than the height on the concave side (P=0.016).There was a significant difference between the scoliosis group and the control group (P=0.003),and between T-value and the rate of osteoporosis between the two groups (both P <0.001).Results were verified using multiple linear regression analysis.Conclusions Degenerative lumbar scoliosis is accompanied by height asymmetry between the intervertebral disc and vertebral body regarding the convex and concave surfaces.There is a positive correlation between the angle of scoliosis and

  2. Foundations of Black Hole Accretion Disk Theory.

    Science.gov (United States)

    Abramowicz, Marek A; Fragile, P Chris

    2013-01-01

    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves. In this light we discuss how accretion disks might reveal some of the unique signatures of strong gravity: the event horizon, the innermost stable circular orbit, and the ergosphere. We then review, from a first-principles perspective, the physical processes at play in accretion disks. This leads us to the four primary accretion disk models that we review: Polish doughnuts (thick disks), Shakura-Sunyaev (thin) disks, slim disks, and advection-dominated accretion flows (ADAFs). After presenting the models we discuss issues of stability, oscillations, and jets. Following our review of the analytic work, we take a parallel approach in reviewing numerical studies of black hole accretion disks. We finish with a few select applications that highlight particular astrophysical applications: measurements of black hole mass and spin, black hole vs. neutron star accretion disks, black hole accretion disk spectral states, and quasi-periodic oscillations (QPOs).

  3. Ring shaped dust accumulation in transition disks

    CERN Document Server

    Pinilla, P; Birnstiel, T

    2012-01-01

    Context.Transition disks are believed to be the final stages of protoplanetary disks, during which a forming planetary system or photoevaporation processes open a gap in the inner disk, drastically changing the disk structure. From theoretical arguments it is expected that dust growth, fragmentation and radial drift are strongly influenced by gas disk structure, and pressure bumps in disks have been suggested as key features that may allow grains to converge and grow efficiently. Aims. We want to study how the presence of a large planet in a disk influences the growth and radial distribution of dust grains, and how observable properties are linked to the mass of the planet. Methods. We combine two-dimensional hydrodynamical disk simulations of disk-planet interactions with state-of-the-art coagulation/fragmentation models to simulate the evolution of dust in a disk which has a gap created by a massive planet. We compute images at different wavelengths and illustrate our results using the example of the transi...

  4. Thin disk lasers: history and prospects

    Science.gov (United States)

    Speiser, Jochen

    2016-04-01

    During the early 1990s, collaboration between the German Aerospace Center and the University of Stuttgart started to work on the Thin Disk concept. The core idea behind the thin disk design is the use of a thin, disk-shaped active medium that is cooled through one of the flat faces of the disk. This ensures a large surface-to-volume ratio and therefore provides very efficient thermal management. Today, the thin disk concept is used in various commercial lasers - ranging from compact, efficient low power systems to multi-kW lasers, including cw lasers and also pulsed (femtosecond to nanosecond) oscillators and amplifiers. The whole development of the Thin Disk laser was and will be accompanied by numerical modeling and optimization of the thermal and thermo-mechanic behavior of the disk and also the heat sink structure, mostly based on finite element models. For further increasing the energy and efficiency of pulsed Thin Disk lasers, the effects of amplified spontaneous emission (ASE) are a core issue. Actual efforts are oriented towards short pulse and ultra-short pulse amplifiers with (multi-)kW average power or Joule-class Thin Disk amplifiers, but also on new designs for cw thin disk MOPA designs.

  5. Does the sagittal alignment of the cervical spine have an impact on disk degeneration? Minimum 10-year follow-up of asymptomatic volunteers.

    Science.gov (United States)

    Okada, Eijiro; Matsumoto, Morio; Ichihara, Daisuke; Chiba, Kazuhiro; Toyama, Yoshiaki; Fujiwara, Hirokazu; Momoshima, Suketaka; Nishiwaki, Yuji; Hashimoto, Takeshi; Ogawa, Jun; Watanabe, Masahiko; Takahata, Takeshi

    2009-11-01

    There have been few studies that investigated and clarified the relationships between progression of degenerative changes and sagittal alignment of the cervical spine. The objective of the study was to longitudinally evaluate the relationships among progression of degenerative changes of the cervical spine with age, the development of clinical symptoms and sagittal alignment of the cervical spine in healthy subjects. Out of 497 symptom-free volunteers who underwent MRI and plain radiography of the cervical spine between 1994 and 1996, 113 subjects (45 males and 68 females) who responded to our contacts were enrolled. All subjects underwent another MRI at an average of 11.3 years after the initial study. Their mean age at the time of the initial imaging was 36.6 +/- 14.5 years (11-65 years). The items evaluated on MRI were (1) decrease in signal intensity of the intervertebral disks, (2) posterior disk protrusion, and (3) disk space narrowing. Each item was evaluated using a numerical grading system. The subjects were divided into four groups according to the age and sagittal alignment of the cervical spine, i.e., subjects under or over the age of 40 years, and subjects with the lordosis or non-lordosis type of sagittal alignment of the cervical spine. During the 10-year period, progression of decrease in signal intensity of the disk, posterior disk protrusion, and disk space narrowing were recognized in 64.6, 65.5, and 28.3% of the subjects, respectively. Progression of posterior disk protrusion was significantly more frequent in subjects over 40 years of age with non-lordosis type of sagittal alignment. Logistic regression analysis revealed that stiff shoulder was closely correlated with females (P = 0.001), and that numbness of the upper extremity was closely correlated with age (P = 0.030) and male (P = 0.038). However, no significant correlation between the sagittal alignment of the cervical spine and clinical symptoms was detected. Sagittal alignment of the

  6. Sagittal spinopelvic parameters in 2-level lumbar degenerative spondylolisthesis

    Science.gov (United States)

    Wang, Tao; Wang, Hui; Liu, Huan; Ma, Lei; Liu, Feng-Yu; Ding, Wen-Yuan

    2016-01-01

    Abstract The purpose of our study is to evaluate sagittal parameters in 2-level lumbar degenerative spondylolisthesis (DS) (TLDS). A total of 15 patients with TLDS, 40 patients with single-level DS (SLDS), and 30 normal volunteers as control were included in our study. All subjects performed on full spine X-ray. Two categorized data were analyzed: patient characteristics—age, sex, body mass index, radiographic parameters-pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), sacral slope (SS), PI–LL, Cobb between the fifth thoracic vertebral and 12th thoracic vertebral (T5–T12), sagittal vertical axis (SVA) Cobb angle of spondylolisthesis level (CSL), ratio of PT to SS (PT/SS), CSL/LL, variation trend of SS over PI, and LL over PI. The PI (73.1° vs 52.9°), SS (50.8° vs 32.2°), LL (53.1° vs 46.9°), SVA (66.1 vs 22.0 mm), PI–LL (20.0° vs 6.0°), and CSL (23.6° vs 20.0°) in TLDS were significantly larger than these in SLDS. The PI (73.1° vs 40.6°), PT (22.3° vs 17.1°), SS (50.8° vs 23.5°), LL (53.1° vs 32.5°), PI–LL (20.0° vs 8.1°), and SVA (66.1 vs 17.0 mm) in TLDS were significantly larger than those in the normal group (NG). The PI (52.9° vs 40.6°), PT (21.0° vs 17.1°), SS (32.2° vs 23.5°), LL (46.9° vs 32.5°), and SVA (22.0 vs 17.0 mm) in SLDS were significantly higher than those in NG. However, PT/SS (44.0%), LL over PI (y = 0.39x + 24.25), SS over PI (y = 10.79 + 0.55x) were lower in TLDS than these in SLDS (63.8%, y = 0.41x + 25, y = 0.65x − 2.09, respectively), and the similar tend between SLDS and NG (74.0%, y = 0.49x + 13.09, y = 0.67x − 3.9, respectively). Our results showed that 2-level lumbar DS, which was caused by multiple-factors, has a severe sagittal imbalance, but single-level has not any. When we plan for surgical selection for 2-level lumbar DS, global sagittal balance must be considered. PMID:27977581

  7. Sacroiliac joint motion in patients with degenerative lumbar spine disorders.

    Science.gov (United States)

    Nagamoto, Yukitaka; Iwasaki, Motoki; Sakaura, Hironobu; Sugiura, Tsuyoshi; Fujimori, Takahito; Matsuo, Yohei; Kashii, Masafumi; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2015-08-01

    OBJECT Usually additional anchors into the ilium are necessary in long fusion to the sacrum for degenerative lumbar spine disorders (DLSDs), especially for adult spine deformity. Although the use of anchors is becoming quite common, surgeons must always keep in mind that the sacroiliac (SI) joint is mobile and they should be aware of the kinematic properties of the SI joint in patients with DLSDs, including adult spinal deformity. No previous study has clarified in vivo kinematic changes in the SI joint with respect to patient age, sex, or parturition status or the presence of DLSDs. The authors conducted a study to clarify the mobility and kinematic characteristics of the SI joint in patients with DLSDs in comparison with healthy volunteers by using in vivo 3D motion analysis with voxel-based registration, a highly accurate, noninvasive method. METHODS Thirteen healthy volunteers (the control group) and 20 patients with DLSDs (the DLSD group) underwent low-dose 3D CT of the lumbar spine and pelvis in 3 positions (neutral, maximal trunk flexion, and maximal trunk extension). SI joint motion was calculated by computer processing of the CT images (voxel-based registration). 3D motion of the SI joint was expressed as both 6 df by Euler angles and translations on the coordinate system and a helical axis of rotation. The correlation between joint motion and the cross-sectional area of the trunk muscles was also investigated. RESULTS SI joint motion during trunk flexion-extension was minute in healthy volunteers. The mean rotation angles during trunk flexion were 0.07° around the x axis, -0.02° around the y axis, and 0.16° around the z axis. The mean rotation angles during trunk extension were 0.38° around the x axis, -0.08° around the y axis, and 0.08° around the z axis. During trunk flexion-extension, the largest amount of motion occurred around the x axis. In patients with DLSDs, the mean rotation angles during trunk flexion were 0.57° around the x axis, 0.01

  8. The early evolution of protostellar disks

    Science.gov (United States)

    Stahler, Steven W.; Korycansky, D. G.; Brothers, Maxwell J.; Touma, Jihad

    1994-01-01

    We consider the origin and intital growth of the disks that form around protostars during the collapse of rotating molecular cloud cores. These disks are assumed to be inviscid and pressure free, and to have masses small compared to those of their central stars. We find that there exist three distinct components-an outer disk, in which shocked gas moves with comparable azimuthal and radical velocities; and inner disk, where material follows nearly circular orbits, but spirals slowly toward the star because of the drag exerted by adjacent onfalling matter, and a turbulent ring adjoining the first two regions. Early in the evolution, i.e., soon after infalling matter begins to miss the star, only the outer disk is present, and the total mass acceration rate onto the protostar is undiminished. Once the outer disk boundary grows to more than 2.9 times the stellar radius, first the ring, and then the inner disk appear. Thereafter, the radii of all three components expand as t(exp 3). The mass of the ring increase with time and is always 13% of the total mass that has fallen from the cloud. Concurrently with the buildup of the inner disk and ring, the accretion rate onto the star falls off. However, the protostellar mass continue to rise, asymptotically as t(exp 1/4). We calculated the radiated flux from the inner and outer disk components due to the release of gravitational potential energy. The flux from the inner disk is dominant and rises steeply toward the stellar surface. We also determine the surface temperature of the inner disk as a function of radius. The total disk luminosity decreases slowly with time, while the contributions from the ring and inner disk both fall as t(exp -2).

  9. Generalized Similarity for Accretion/Decretion Disks

    Science.gov (United States)

    Rafikov, Roman R.

    2016-10-01

    Decretion (or external) disks are gas disks freely expanding to large radii due to their internal stresses. They are expected to naturally arise in tidal disruption events, around Be stars, in mass-losing post-main-sequence binaries, as a result of supernova fallback, etc. Their evolution is theoretically understood in two regimes: when the central object does not exert torque on the disk (a standard assumption for conventional accretion disks) or when no mass inflow (or outflow) occurs at the disk center. However, many astrophysical objects—circumbinary disks, Be stars, neutron stars accreting in a propeller regime, etc.—feature non-zero torque simultaneously with the non-zero accretion (or ejection of mass) at the disk center. We provide a general description for the evolution of such disks (both linear and nonlinear) in the self-similar regime, to which the disk should asymptotically converge with time. We identify a similarity parameter λ, which is uniquely related to the degree, to which the central mass accretion is suppressed by the non-zero central torque. The known decretion disk solutions correspond to the two discrete values of λ, while our new solutions cover a continuum of its physically allowed values, corresponding to either accretion or mass ejection by the central object. A direct relationship between λ and central \\dot{M} and torque is also established. We describe the time evolution of the various disk characteristics for different λ, and show that the observable properties (spectrum and luminosity evolution) of the decretion disks, in general, are different from the standard accretion disks with no central torque.

  10. Secular Evolution in Disk Galaxies

    Science.gov (United States)

    Kormendy, John

    2013-10-01

    Self-gravitating systems evolve toward the most tightly bound configuration that is reachable via the evolution processes that are available to them. They do this by spreading -- the inner parts shrink while the outer parts expand -- provided that some physical process efficiently transports energy or angular momentum outward. The reason is that self-gravitating systems have negative specific heats. As a result, the evolution of stars, star clusters, protostellar and protoplanetary disks, black hole accretion disks and galaxy disks are fundamentally similar. How evolution proceeds then depends on the evolution processes that are available to each kind of self-gravitating system. These processes and their consequences for galaxy disks are the subjects of my lectures and of this Canary Islands Winter School. I begin with a review of the formation, growth and death of bars. Then I review the slow (`secular') rearrangement of energy, angular momentum, and mass that results from interactions between stars or gas clouds and collective phenomena such as bars, oval disks, spiral structure and triaxial dark haloes. The `existence-proof' phase of this work is largely over: we have a good heuristic understanding of how nonaxisymmetric structures rearrange disk gas into outer rings, inner rings and stuff dumped onto the centre. The results of simulations correspond closely to the morphology of barred and oval galaxies. Gas that is transported to small radii reaches high densities. Observations confirm that many barred and oval galaxies have dense central concentrations of gas and star formation. The result is to grow, on timescales of a few Gyr, dense central components that are frequently mistaken for classical (elliptical-galaxy-like) bulges but that were grown slowly out of the disk (not made rapidly by major mergers). The resulting picture of secular galaxy evolution accounts for the richness observed in galaxy structure. We can distinguish between classical and pseudo

  11. Radiographic distinction of degenerative slippage (spondylolisthesis and retrolisthesis) from traumatic slippage of the cervical spine

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.; Woodring, J.H.; Rogers, L.F.; Kim, K.S.

    1986-08-01

    In a review of 42 cases of degenerative arthritis of the cervical spine and 22 cases of cervical spine trauma with an observed anterior slip-page (spondylolisthesis) or posterior slippage (retrolisthesis) of the vertebral bodies of 2 mm or more, characteristic features were observed which allowed distinction between degenerative and traumatic slippage of the cervical spine. In degenerative slippage the shape of the articular facets and width of the facet joint space may remain normal; however, in most cases the articular facets become 'ground-down' with narrowing of the facet joint space and the articular facets themselves becoming thinned or ribbon-like. In traumatic slippage the articular facets will either be normally shaped or fractured and the facet joint space will be abnormally widened. Plain radiographs will usually allow this distinction to be made; however, in difficult cases polytomography may be required.

  12. Induced pluripotent stem cells for retinal degenerative diseases: a new perspective on the challenges

    Indian Academy of Sciences (India)

    Zi-Bing Jin; Satoshi Okamoto; Michiko Mandai; Masayo Takahashi

    2009-12-01

    Retinal degenerative diseases, including age-related macular degeneration and retinitis pigmentosa, are the prodominant causes of human blindness in the world; however, these diseases are difficult to treat. Currently, knowledge on the mechanisms of these diseases is still very limited and no radical drugs are available. Induced pluripotent stem (iPS) cells are an innovative technology that turns somatic cells into embryonic stem (ES)-like cells with pluripotent potential via the exogenous expression of several key genes. It can be used as an unlimited source for cell differentiation or tissue engineering, either of which is a promising therapy for human degenerative diseases. Induced pluripotent cells are both an unlimited source for retinal regeneration and an expectant tool for pharmaprojects and developmental or disease modelling. In this review, we try to summarize the advancement of iPS-based technologies and the potential utility for retinal degenerative diseases. We also discuss the challenges of using this technology in the retinology field.

  13. Radiographical analysis concernig the etiology of degenerative spondylolisthesis of the lumbar spine

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Koichiro (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1989-12-01

    The purpose of this article is to evaluate radiographically degenerative spondylolisthesis of the lumbar spine, with the main focus on the configuration of posterior elements. A comparative study between 49 cases of degenerative spondylolisthesis and 99 cases of other lumbar disorders was performed, using 13 radiographical parameters. The results clearly indicate the posterior elements of degenerative spondylolisthesis shifted horizontally and sagittally to allow slipping. This was due to the weak bony hook mechanism. Furthermore, almost all facet joints were morphologically classified as sagittal or intermediate type. Another meaningful difference was the alignment of the lumbar spine which showed an increase in both lordosis and lumbosacral angle. On the other hand, the level of Jacoby's line was almost the same in both groups. These characteristic configurations could be the cause of listhesis, although further study should be carried out to elucidate whether they are present at the non-listhetic stage. (author).

  14. Intervertebral Fusion with Mobile Microendoscopic Discectomy for Lumbar Degenerative Disc Disease.

    Science.gov (United States)

    Xu, Bao-Shan; Liu, Yue; Xu, Hai-Wei; Yang, Qiang; Ma, Xin-Long; Hu, Yong-Cheng

    2016-05-01

    The aim of this article is to introduce a technique for lumbar intervertebral fusion that incorporates mobile microendoscopic discectomy (MMED) for lumbar degenerative disc disease. Minimally invasive transforaminal lumbar interbody fusion is frequently performed to treat degenerative diseases of the lumbar spine; however, the scope of such surgery and vision is limited by what the naked eye can see through the expanding channel system. To expand the visual scope and reduce trauma, we perform lumbar intervertebral fusion with the aid of a MMED system that provides a wide field through freely tilting the surgical instrument and canals. We believe that this technique is a good option for treating lumbar degenerative disc disease that requires lumbar intervertebral fusion.

  15. Artificial chordae for degenerative mitral valve disease: critical analysis of current techniques

    Science.gov (United States)

    Ibrahim, Michael; Rao, Christopher; Athanasiou, Thanos

    2012-01-01

    The surgical repair of degenerative mitral valve disease involves a number of technical points of importance. The use of artificial chordae for the repair of degenerative disease has increased as a part of the move from mitral valve replacement to repair of the mitral valve. The use of artificial chordae provides an alternative to the techniques pioneered by Carpentier (including the quadrangular resection, transfer of native chordae and papillary muscle shortening/plasty), which can be more technically difficult. Despite a growth in their uptake and the indications for their use, a number of challenges remain for the use of artificial chordae in mitral valve repair, particularly in the determination of the correct length to ensure optimal leaflet coaptation. Here, we analyse over 40 techniques described for artificial chordae mitral valve repair in the setting of degenerative disease. PMID:22962321

  16. When dialogue fails. Music therapy with elderly with neurological degenerative diseases

    DEFF Research Database (Denmark)

    Wigram, Anthony Lewis

    2004-01-01

    traces in the brain. Using the same “hello-song” in the beginning of a session - session after session - gives stability. Stability is constancy and familiarity of cues over time (Roberts & Algase 1988), and even people with severe memory deficits are capable of creating new memory traces and of learning......When dialogue fails. Music therapy with elderly with neurological degenerative diseases. In persons suffering from neurological degenerative diseases we often see the following symptoms: difficulties in remembering, concentrating, perceiving input, and controlling and timing movements. Normal every...... degenerative disease like e.g. dementia are often socially isolated because of their failing abilities to communicate. Even if they live in a facility and are surrounded by care staff and peer residents, they might experience the environment as chaotic and the people as non-comprehensible. A missing meaningful...

  17. Evaluation of intravertebral changes associated with the disk degeneration based on the MRI findings

    Energy Technology Data Exchange (ETDEWEB)

    Saiki, Natoru [Dokkyo Univ. School of Medicine, Mibu, Tochigi (Japan)

    2000-03-01

    The magnetic resonance images (MRI) of 441 vertebral bodies of the 199 patients with intravertebral abnormality associated with adjacent disk degeneration were evaluated according to the Modic classification and a new geographic classification. They were also evaluated in relation with the various factors including disk space narrowing, vacuum phenomenon, disk herniation, Schmorl's node, ostephyte formation and spondylolisthesis. The new geographic classification is based on the three factors; depth of invasion: stage 1 (thin layer along the end-plate), stage 2 (less than a half of the vertebral height) and stage 3 (more than a half of the vertebral height), shape: end-plate type, Schmorl's node type, triangle type, meniscus type and band type, location: front type, center type, rear type, front and rear type and whole type. Only about a half of the vertebral bodies with intervertebral abnormality showed bilateral invasion adjacent to the degenerative disks on both sides and the superior edges were much more frequently involved than the inferior ones. There was relatively higher incidence (7%) of Modic Type I degeneration defined as high signal intensity (HSI) on T2 weighted spin-echo images (T2WI) and low signal intensity (LSI) on T1 weighted spin-echo images (T1WI) representing vascularized fibrous tissue than those previously reported. On the other hand there was relatively lower incidence (5%) of Modic Type II degeneration defined as high or iso intensity on T1WI and HSI on T2WI. Triangle front type was seen in almost a half of the vertebrae in stage 2 and stage 3, and the rest was divided into meniscus type and band type almost evenly. The end plate front type must be a precursor of the triangle front type. The Schmorl's node type was considered to be a precursor of the meniscus type as well as band type in some but many must stay in its form transformed to Type II degeneration. In general, the intravertebral abnormality may not be necessary to

  18. Lumbar degenerative spinal deformity: Surgical options of PLIF, TLIF and MI-TLIF

    Directory of Open Access Journals (Sweden)

    Hey Hwee Weng

    2010-01-01

    Full Text Available Degenerative disease of the lumbar spine is common in ageing populations. It causes disturbing back pain, radicular symptoms and lowers the quality of life. We will focus our discussion on the surgical options of posterior lumbar interbody fusion (PLIF and transforaminal lumbar interbody fusion (TLIF and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF for lumbar degenerative spinal deformities, which include symptomatic spondylolisthesis and degenerative scoliosis. Through a description of each procedure, we hope to illustrate the potential benefits of TLIF over PLIF. In a retrospective study of 53 ALIF/PLIF patients and 111 TLIF patients we found reduced risk of vessel and nerve injury in TLIF patients due to less exposure of these structures, shortened operative time and reduced intra-operative bleeding. These advantages could be translated to shortened hospital stay, faster recovery period and earlier return to work. The disadvantages of TLIF such as incomplete intervertebral disc and vertebral end-plate removal and potential occult injury to exiting nerve root when under experienced hands are rare. Hence TLIF remains the mainstay of treatment in degenerative deformities of the lumbar spine. However, TLIF being a unilateral transforaminal approach, is unable to decompress the opposite nerve root. This may require contralateral laminotomy, which is a fairly simple procedure.The use of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF to treat degenerative lumbar spinal deformity is still in its early stages. Although the initial results appear promising, it remains a difficult operative procedure to master with a steep learning curve. In a recent study comparing 29 MI-TLIF patients and 29 open TLIF, MI-TLIF was associated with longer operative time, less blood loss, shorter hospital stay, with no difference in SF-36 scores at six months and two years. Whether it can replace traditional TLIF as the surgery of

  19. Astrophysical disks Collective and Stochastic Phenomena

    CERN Document Server

    Fridman, Alexei M; Kovalenko, Ilya G

    2006-01-01

    The book deals with collective and stochastic processes in astrophysical discs involving theory, observations, and the results of modelling. Among others, it examines the spiral-vortex structure in galactic and accretion disks , stochastic and ordered structures in the developed turbulence. It also describes sources of turbulence in the accretion disks, internal structure of disk in the vicinity of a black hole, numerical modelling of Be envelopes in binaries, gaseous disks in spiral galaxies with shock waves formation, observation of accretion disks in a binary system and mass distribution of luminous matter in disk galaxies. The editors adaptly brought together collective and stochastic phenomena in the modern field of astrophysical discs, their formation, structure, and evolution involving the methodology to deal with, the results of observation and modelling, thereby advancing the study in this important branch of astrophysics and benefiting Professional Researchers, Lecturers, and Graduate Students.

  20. Counterrotating Stars in Simulated Galaxy Disks

    CERN Document Server

    Algorry, David G; Abadi, Mario G; Sales, Laura V; Steinmetz, Matthias; Piontek, Franziska

    2013-01-01

    Counterrotating stars in disk galaxies are a puzzling dynamical feature whose origin has been ascribed to either satellite accretion events or to disk instabilities triggered by deviations from axisymmetry. We use a cosmological simulation of the formation of a disk galaxy to show that counterrotating stellar disk components may arise naturally in hierarchically-clustering scenarios even in the absence of merging. The simulated disk galaxy consists of two coplanar, overlapping stellar components with opposite spins: an inner counterrotating bar-like structure made up mostly of old stars surrounded by an extended, rotationally-supported disk of younger stars. The opposite-spin components originate from material accreted from two distinct filamentary structures which at turn around, when their net spin is acquired, intersect delineating a "V"-like structure. Each filament torques the other in opposite directions; the filament that first drains into the galaxy forms the inner counterrotating bar, while material ...

  1. Molecular Gas in Young Debris Disks

    Science.gov (United States)

    Moór, Attila; Kóspál, Ágnes; Ábrahám, Péter; Juhász, Attila; Apai, Dániel; Csengeri, Timea; Grady, Carol; Henning, Thomas; Kiss, Csaba; Pascucci, Ilaria

    2013-07-01

    Gas-rich primordial disks and tenuous gas-poor debris disks are usually considered as two distinct evolutionary phases of the circumstellar matter. So far only a very few debris disks with measurable gas component have been known. We carried out a survey with the APEX radio telescope to detect molecular gas at millimeter wavelengths in 28 infrared-luminous young debris disks, and discovered two new systems with substantial amount of CO. Motivated to understand the origin, physics, and evolutionary status of the gas in these systems we observed one of them, HD 21997, with ALMA and Herschel. Our results suggest that HD 21997 may be a hybrid system where secondary debris dust and residual primordial gas coexist. This poses a serious question to the current paradigm, since the age of the system (30 Myr) significantly exceeds model predictions for disk clearing and the ages of the oldest transitional disks.

  2. Erasing Data and Recycling of Optical Disks

    Directory of Open Access Journals (Sweden)

    T Fujita

    2007-03-01

    Full Text Available Optical disks, DVDs and CDs, are convenient recording media on which to safely store data for a long period of time. However, the complete data erasure from recorded media is also important for the security of the data. After erasure of data from optical disks, recycling the material is needed in order to recover the valuable components of the optical disks. Here, data erasure methods for optical disks are discussed in the view of material recycling. The main finding of the study is that the explosion of optical disks in water is a very suitable method for complete erasure of data on the disks as well as recycling of their materials.

  3. Non-isothermal effects on Be disks

    CERN Document Server

    Vieira, Rodrigo G; Bjorkman, Jon E

    2016-01-01

    In the last decade, the viscous decretion disk model has emerged as the new paradigm for Be star disks. In this contribution, we propose a simple analytical model to estimate the continuum infrared excess arising from these circumstellar disks, in the light of the currently accepted scenario. We demonstrate that the disk can be satisfactorily described by a two component system: an inner optically thick region, which we call the pseudo-photosphere, and a diffuse outer part. In particular, a direct connexion between the disk brightness profile and the thermal structure is derived, and then confronted to realistic numerical simulations. This result quantifies how the non-isothermality of the disk ultimately affects both infrared measured fluxes and visibilities.

  4. Dusty Disks around White Dwarfs I: Origin of Debris Disks

    CERN Document Server

    Dong, Ruobing; Lin, D N C; Liu, X -W

    2010-01-01

    A significant fraction of the mature FGK stars have cool dusty disks at least an orders of magnitudes brighter than the solar system's outer zodiacal light. Since such dusts must be continually replenished, they are generally assumed to be the collisional fragments of residual planetesimals analogous to the Kuiper Belt objects. At least 10% of solar type stars also bear gas giant planets. The fraction of stars with known gas giants or detectable debris disks (or both) appears to increase with the stellar mass. Here, we examine the dynamical evolution of systems of long-period gas giant planets and residual planetesimals as their host stars evolve off the main sequence, lose mass, and form planetary nebula around remnant white dwarf cores. The orbits of distant gas giant planets and super-km-size planetesimals expand adiabatically. During the most intense AGB mass loss phase, sub-meter-size particles migrate toward their host stars due to the strong hydrodynamical drag by the intense stellar wind. Along their ...

  5. Precocious Degenerative Arthropathy And Bluish Patches On Ears : Ochronosis And Alkaptonuria

    Directory of Open Access Journals (Sweden)

    Mahajan Vikram K

    2004-01-01

    Full Text Available Alkaptonuria is a rare, autosomal recessive disorder of phenylalanin/tyrosine metabolism due to congenital deficiency of the enzyme homogentisic acid oxidase. The diagnosis is clinical and the triad of homogentisic aciduria, ochronosis and precocious degenerative arthritis is characteristic. Its diagnosis in infancy and early therapeutic intervention help delaying its complications. These patients may remain undiagnosed until the darkening of urine soaked diapers is noticed or the early degenerative arthropathy develops. This paper describes two cases of alkaptonuria presenting late in life; one of them had associated hyperthyroidism.

  6. Meniscal Ramp Lesions

    Science.gov (United States)

    Chahla, Jorge; Dean, Chase S.; Moatshe, Gilbert; Mitchell, Justin J.; Cram, Tyler R.; Yacuzzi, Carlos; LaPrade, Robert F.

    2016-01-01

    Meniscal ramp lesions are more frequently associated with anterior cruciate ligament (ACL) injuries than previously recognized. Some authors suggest that this entity results from disruption of the meniscotibial ligaments of the posterior horn of the medial meniscus, whereas others support the idea that it is created by a tear of the peripheral attachment of the posterior horn of the medial meniscus. Magnetic resonance imaging (MRI) scans have been reported to have a low sensitivity, and consequently, ramp lesions often go undiagnosed. Therefore, to rule out a ramp lesion, an arthroscopic evaluation with probing of the posterior horn of the medial meniscus should be performed. Several treatment options have been reported, including nonsurgical management, inside-out meniscal repair, or all-inside meniscal repair. In cases of isolated ramp lesions, a standard meniscal repair rehabilitation protocol should be followed. However, when a concomitant ACL reconstruction (ACLR) is performed, the rehabilitation should follow the designated ACLR postoperative protocol. The purpose of this article was to review the current literature regarding meniscal ramp lesions and summarize the pertinent anatomy, biomechanics, diagnostic strategies, recommended treatment options, and postoperative protocol. PMID:27504467

  7. Early dust evolution in protostellar accretion disks

    OpenAIRE

    2000-01-01

    We investigate dust dynamics and evolution during the formation of a protostellar accretion disk around intermediate mass stars via 2D numerical simulations. Using three different detailed dust models, compact spherical particles, fractal BPCA grains, and BCCA grains, we find that even during the early collapse and the first 10,000 yr of dynamical disk evolution, the initial dust size distribution is strongly modified. Close to the disk's midplane coagulation produces dust particles of sizes ...

  8. ON THE FORMATION OF GALACTIC THICK DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Minchev, I.; Streich, D.; Scannapieco, C.; De Jong, R. S.; Steinmetz, M. [Leibniz-Institut für Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Martig, M. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany)

    2015-05-01

    Recent spectroscopic observations in the Milky Way suggest that the chemically defined thick disk (stars that have high [α/Fe] ratios and are thus old) has a significantly smaller scale-length than the thin disk. This is in apparent contradiction with observations of external edge-on galaxies, where the thin and thick components have comparable scale-lengths. Moreover, while observed disks do not flare (scale-height does not increase with radius), numerical simulations suggest that disk flaring is unavoidable, resulting from both environmental effects and secular evolution. Here we address these problems by studying two different suites of simulated galactic disks formed in the cosmological context. We show that the scale-heights of coeval populations always increase with radius. However, the total population can be decomposed morphologically into thin and thick disks, which do not flare. We relate this to the disk inside-out formation, where younger populations have increasingly larger scale-lengths and flare at progressively larger radii. In this new picture, thick disks are composed of the imbedded flares of mono-age stellar populations. Assuming that disks form inside out, we predict that morphologically defined thick disks must show a decrease in age (or [α/Fe] ratios) with radius and that coeval populations should always flare. This also explains the observed inversion in the metallicity and [α/Fe] gradients for stars away from the disk midplane in the Milky Way. The results of this work are directly linked to, and can be seen as evidence of, inside-out disk growth.

  9. Theory of Disk Accretion onto Magnetic Stars

    Directory of Open Access Journals (Sweden)

    Lai Dong

    2014-01-01

    Full Text Available Disk accretion onto magnetic stars occurs in a variety of systems, including accreting neutron stars (with both high and low magnetic fields, white dwarfs, and protostars. We review some of the key physical processes in magnetosphere-disk interaction, highlighting the theoretical uncertainties. We also discuss some applications to the observations of accreting neutron star and protostellar systems, as well as possible connections to protoplanetary disks and exoplanets.

  10. Theory of Disk Accretion onto Magnetic Stars

    CERN Document Server

    Lai, Dong

    2014-01-01

    Disk accretion onto magnetic stars occurs in a variety of systems, including accreting neutron stars (with both high and low magnetic fields), white dwarfs, and protostars. We review some of the key physical processes in magnetosphere-disk interaction, highlighting the theoretical uncertainties. We also discuss some applications to the observations of accreting neutron stars and protostellar systems, as well as possible connections to protoplanetary disks and exoplanets.

  11. Protoplanetary Disks in Multiple Star Systems

    Science.gov (United States)

    Harris, Robert J.

    Most stars are born in multiple systems, so the presence of a stellar companion may commonly influence planet formation. Theory indicates that companions may inhibit planet formation in two ways. First, dynamical interactions can tidally truncate circumstellar disks. Truncation reduces disk lifetimes and masses, leaving less time and material for planet formation. Second, these interactions might reduce grain-coagulation efficiency, slowing planet formation in its earliest stages. I present three observational studies investigating these issues. First is a spatially resolved Submillimeter Array (SMA) census of disks in young multiple systems in the Taurus-Auriga star-forming region to study their bulk properties. With this survey, I confirmed that disk lifetimes are preferentially decreased in multiples: single stars have detectable millimeter-wave continuum emission twice as often as components of multiples. I also verified that millimeter luminosity (proportional to disk mass) declines with decreasing stellar separation. Furthermore, by measuring resolved-disk radii, I quantitatively tested tidal-truncation theories: results were mixed, with a few disks much larger than expected. I then switch focus to the grain-growth properties of disks in multiple star systems. By combining SMA, Combined Array for Research in Millimeter Astronomy (CARMA), and Jansky Very Large Array (VLA) observations of the circumbinary disk in the UZ Tau quadruple system, I detected radial variations in the grain-size distribution: large particles preferentially inhabit the inner disk. Detections of these theoretically predicted variations have been rare. I related this to models of grain coagulation in gas disks and find that our results are consistent with growth limited by radial drift. I then present a study of grain growth in the disks of the AS 205 and UX Tau multiple systems. By combining SMA, Atacama Large Millimeter/submillimeter Array (ALMA), and VLA observations, I detected radial

  12. Structure, mass and stability of galactic disks

    CERN Document Server

    van der Kruit, P C

    2010-01-01

    In this review I concentrate on three areas related to structure of disks in spiral galaxies. First I will review the work on structure, kinematics and dynamics of stellar disks. Next I will review the progress in the area of flaring of HI layers. These subjects are relevant for the presence of dark matter and lead to the conclusion that disk are in general not `maximal', have lower M/L ratios than previously suspected and are locally stable w.r.t. Toomre's Q criterion for local stability. I will end with a few words on `truncations' in stellar disks.

  13. Evaluation of powder metallurgy superalloy disk materials

    Science.gov (United States)

    Evans, D. J.

    1975-01-01

    A program was conducted to develop nickel-base superalloy disk material using prealloyed powder metallurgy techniques. The program included fabrication of test specimens and subscale turbine disks from four different prealloyed powders (NASA-TRW-VIA, AF2-1DA, Mar-M-432 and MERL 80). Based on evaluation of these specimens and disks, two alloys (AF2-1DA and Mar-M-432) were selected for scale-up evaluation. Using fabricating experience gained in the subscale turbine disk effort, test specimens and full scale turbine disks were formed from the selected alloys. These specimens and disks were then subjected to a rigorous test program to evaluate their physical properties and determine their suitability for use in advanced performance turbine engines. A major objective of the program was to develop processes which would yield alloy properties that would be repeatable in producing jet engine disks from the same powder metallurgy alloys. The feasibility of manufacturing full scale gas turbine engine disks by thermomechanical processing of pre-alloyed metal powders was demonstrated. AF2-1DA was shown to possess tensile and creep-rupture properties in excess of those of Astroloy, one of the highest temperature capability disk alloys now in production. It was determined that metallographic evaluation after post-HIP elevated temperature exposure should be used to verify the effectiveness of consolidation of hot isostatically pressed billets.

  14. Circumstellar Debris Disks: Diagnosing the Unseen Perturber

    CERN Document Server

    Nesvold, Erika R; Vican, Laura; Farr, Will M

    2016-01-01

    The first indication of the presence of a circumstellar debris disk is usually the detection of excess infrared emission from the population of small dust grains orbiting the star. This dust is short-lived, requiring continual replenishment, and indicating that the disk must be excited by an unseen perturber. Previous theoretical studies have demonstrated that an eccentric planet orbiting interior to the disk will stir the larger bodies in the belt and produce dust via interparticle collisions. However, motivated by recent observations, we explore another possible mechanism for heating a debris disk: a stellar-mass perturber orbiting exterior to and inclined to the disk and exciting the disk particles' eccentricities and inclinations via the Kozai-Lidov mechanism. We explore the consequences of an exterior perturber on the evolution of a debris disk using secular analysis and collisional N-body simulations. We demonstrate that a Kozai-Lidov excited disk can generate a dust disk via collisions and we compare t...

  15. Modeling the Circumstellar Disk of $\\zeta$ Tauri

    OpenAIRE

    Carciofi, A. C.; Bjorkman, J. E.

    2004-01-01

    We present a model for the disk of the classical Be star $\\zeta$ Tauri. The model consists of a Keplerian rotating disk with a power-law surface density and a vertical density distribution that follows from the balance between the thermal gas pressure and the z-component of the stellar gravitation. The opening angle of such a disk is not a fixed value but increases with the distance to the star (flared disk). We use a Monte Carlo code that solves simultaneously the thermal equilibrium, the st...

  16. Strength of Cracked Reinforced Concrete Disks

    DEFF Research Database (Denmark)

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1999-01-01

    The paper deals with models, based on the theory of plasticity, to be used in strength assessments of reinforced concrete disks suffering from different kinds of cracking. Based on the assumption that the sliding strength of concrete is reduced in sections where cracks are located, solutions...... for the shear strength of disks with initial cracks and disks suffering from isotropic cracking are presented. Furthermore, in the case of isotropicly cracked disks subjected to arbitrary in-plane loading, a general yield condition is derived....

  17. Generalized Similarity for Accretion/Decretion Disks

    CERN Document Server

    Rafikov, Roman R

    2016-01-01

    Decretion (or external) disks are gas disks freely expanding to large radii due to their internal stresses. They are expected to naturally arise in tidal disruption events, around Be stars, in mass-losing post main sequence binaries, as a result of supernova fallback, etc. Their evolution is theoretically understood in two regimes: when the central object does not exert torque on the disk (a standard assumption for conventional accretion disks) or when no mass inflow (or outflow) occurs at the disk center. However, many astrophysical objects - circumbinary disks, Be stars, neutron stars accreting in a propeller regime, etc. - feature non-zero torque simultaneously with the non-zero accretion (or ejection of mass) at the disk center. We provide a general description for the evolution of such disks (both linear and non-linear) in the self-similar regime, to which the disk should asymptotically converge with time. We identify a similarity parameter $\\lambda$, which is uniquely related to the degree, to which the...

  18. Sub-Keplerian accretion onto circumstellar disks

    CERN Document Server

    Visser, R

    2010-01-01

    Models of the formation, evolution and photoevaporation of circumstellar disks are an essential ingredient in many theories of the formation of planetary systems. The ratio of disk mass over stellar mass in the circumstellar phase of a disk is largely determined by the angular momentum of the original cloud core from which the system was formed. While full 3D or 2D axisymmetric hydrodynamical models of accretion onto the disk automatically treat all aspects of angular momentum, this is not so trivial for 1D and semi-2D viscous disk models. Since 1D and semi-2D disk models are still very useful for long-term evolutionary modelling of disks with relatively little numerical effort, we investigate how the 2D nature of accretion affects the formation and evolution of the disk in such models. A proper treatment of this problem requires a correction for the sub-Keplerian velocity at which accretion takes place. We develop an update of our semi-2D time-dependent disk evolution model to properly treat the effects of s...

  19. Managing Carious Lesions

    DEFF Research Database (Denmark)

    Innes, N P T; Frencken, J E; Bjørndal, L

    2016-01-01

    Variation in the terminology used to describe clinical management of carious lesions has contributed to a lack of clarity in the scientific literature and beyond. In this article, the International Caries Consensus Collaboration presents 1) issues around terminology, a scoping review of current...... managementshould be limited to situations involving control of the disease through preventive and noninvasive means at a patient level, whereascarious lesion managementcontrols the disease symptoms at the tooth level. While it is not possible to directly relate the visual appearance of carious lesions' clinical...... manifestations to the histopathology, we have based the terminology around the clinical consequences of disease (soft, leathery, firm, and hard dentine). Approaches to carious tissue removal are defined: 1)selective removal of carious tissue-includingselective removal to soft dentineandselective removal to firm...

  20. Expression of TRAIL and death receptor DR4 in Palmer type 2 TFCC lesions.

    Science.gov (United States)

    Unglaub, Frank; Thomas, Susanne B; Kroeber, Markus W; Dragu, Adrian; Fellenberg, Jörg; Mittlmeier, Thomas; Wolf, Maya B; Horch, Raymund E

    2010-10-01

    Degenerative articular disc perforations of the triangular fibrocartilage (TFC) of the wrist are characterized by fibrocartilage cell loss and are often associated with ulna-plus situations. Apoptosis has been found to play a crucial role in fibrocartilage cell loss, however, the molecular mechanism and mediators are still poorly understood. The purpose of this study was to identify receptors to apoptosis in degenerative disc lesions. Included in the study were 17 patients with degenerative articular disc tears of the TFC (Palmer type 2C). Following arthroscopic debridement of the TFC, histological sections were examined to assess the presence of apoptosis. Apoptosis was determined using TRAIL and death receptor DR4 agonists for immunohistochemical analyses. The number of cells positive for apoptosis was then correlated with ulna length. Cells positive for TRAIL and DR4 were found in all specimens. The number of cells positive for TRAIL was significantly increased in specimens of patients with an ulna positive variance (P = 0.040). However, DR4 was not significantly increased in ulna plus (P > 0.05). Both, TRAIL and DR4 positive cells were found to be evenly distributed throughout each specimen. There was no accumulation of any type of cells in any particular zone of the biopsies. This is the first study that shows that TFCC cells express TRAIL and DR4, which suggests that apoptosis, as well as, mechanical trauma are involved in the development of disc perforation. The TRAIL/DR4 receptor system is a molecular mediator of apoptosis induction in TFC cells and therefore plays a role in cell loss in degenerative disc lesions.

  1. Lesiones deportivas Sports injuries

    OpenAIRE

    2007-01-01

    El estrés generado por la práctica deportiva ha originado una mayor probabilidad de que los atletas presenten lesiones agudas y crónicas. En el ámbito mundial existen diferentes investigaciones acerca de la incidencia de lesiones deportivas. La comparación de sus resultados es difícil por las diferencias en las características de la población y en la forma de reportar los datos, que varía ampliamente entre los estudios (proporciones o tasas de incidencia o tasas por cada 100 ó 1.000 participa...

  2. Dust amorphization in protoplanetary disks

    CERN Document Server

    Glauser, Adrian M; Watson, Dan M; Henning, Thomas; Schegerer, Alexander A; Wolf, Sebastian; Audard, Marc; Baldovin-Saavedra, Carla

    2009-01-01

    High-energy irradiation of the circumstellar material might impact the structure and the composition of a protoplanetary disk and hence the process of planet formation. In this paper, we present a study on the possible influence of the stellar irradiation, indicated by X-ray emission, on the crystalline structure of the circumstellar dust. The dust crystallinity is measured for 42 class II T Tauri stars in the Taurus star-forming region using a decomposition fit of the 10 micron silicate feature, measured with the Spitzer IRS instrument. Since the sample includes objects with disks of various evolutionary stages, we further confine the target selection, using the age of the objects as a selection parameter. We correlate the X-ray luminosity and the X-ray hardness of the central object with the crystalline mass fraction of the circumstellar dust and find a significant anti-correlation for 20 objects within an age range of approx. 1 to 4.5 Myr. We postulate that X-rays represent the stellar activity and consequ...

  3. Hard disks with SCSI interface

    CERN Document Server

    Denisov, O Yu

    1999-01-01

    The testing of 20 models of hard SCSI-disks is carried out: the Fujitsu MAE3091LP; the IBM DDRS-39130, DGHS-318220, DNES-318350, DRHS-36V and DRVS-18V; the Quantum Atlas VI 18.2; the Viking 11 9.1; the Seagate ST118202LW, ST118273LW, ST118273W, ST318203LW, ST318275LW, ST34520W, ST39140LW and ST39173W; and the Western Digital WDE9100-0007, WDE9100-AV0016, WDE9100-AV0030 and WDE9180-0048. All tests ran under the Windows NT 4.0 workstation operating system with Service Pack 4, under video mode with 1024*768 pixel resolution, 32- bit colour depth and V-frequency equal to 85 Hz. The detailed description and characteristics of SCSI stores are presented. Test results (ZD Winstone 99 and ZD WinBench 99 tests) are given in both table and diagram (disk transfer rate) forms. (0 refs).

  4. Turbulent dynamo in a disk

    Energy Technology Data Exchange (ETDEWEB)

    Ruzmaikin, A.A.; Sokolov, D.D.; Turchaninov, V.I.

    1980-03-01

    The large-scale magnetic field in a rotating, turbulent gaseous disk will be generated by a dynamo process (the ..cap alpha omega..-dynamo) determined by the differential rotation ..omega..(r) and the spirality function ..cap alpha..(z). The generation is best described by a difference approximation to the dynamo equations, using a step greater than the turbulence correlation length and a smooth function ..cap alpha..(z). The critical dynamo-number for exciting the lowest even quadrupole mode is D/sub q/ = -8. The odd dipole mode will be excited only for large dynamo-numberabsolute value (D/sub d/) > or approx. = 500. When absolute value (D) > or approx. = 20, all modes other than the lowest quadrupole mode (for which the threshold Dapprox. =-500) are oscillatory. The results are applied to the Galaxy (D approx. = -10; characteristic growth time, 3 x 10/sup 8/ yr) and to accretion disks in binary systems containing a black hole, where several oscillatory modes can be excited.

  5. Circumplanetary disk or circumplanetary envelope?

    CERN Document Server

    Szulágyi, J; Lega, E; Crida, A; Morbidelli, A; Guillot, T

    2016-01-01

    We present three-dimensional simulations with nested meshes of the dynamics of the gas around a Jupiter mass planet with the JUPITER and FARGOCA codes. We implemented a radiative transfer module into the JUPITER code to account for realistic heating and cooling of the gas. We focus on the circumplanetary gas flow, determining its characteristics at very high resolution ($80\\%$ of Jupiter's diameter). In our nominal simulation where the temperature evolves freely by the radiative module and reaches 13000 K at the planet, a circumplanetary envelope was formed filling the entire Roche-lobe. Because of our equation of state is simplified and probably overestimates the temperature, we also performed simulations with limited maximal temperatures in the planet region (1000 K, 1500 K, and 2000 K). In these fixed temperature cases circumplanetary disks (CPDs) were formed. This suggests that the capability to form a circumplanetary disk is not simply linked to the mass of the planet and its ability to open a gap. Inste...

  6. Thick-disk Evolution Induced by the Growth of an Embedded Thin Disk

    NARCIS (Netherlands)

    Villalobos, Álvaro; Kazantzidis, Stelios; Helmi, Amina

    2010-01-01

    We perform collisionless N-body simulations to investigate the evolution of the structural and kinematical properties of simulated thick disks induced by the growth of an embedded thin disk. The thick disks used in the present study originate from cosmologically common 5:1 encounters between initial

  7. The physical and chemical evolution of protostellar disks. The growth of protostellar disks: Progress to date

    Science.gov (United States)

    Stahler, Steven W.

    1993-01-01

    This study constitutes one part of our multi-disciplinary approach to the evolution of planet-forming disks. The goal is to establish the disks' thermal and mechanical properties as they grow by the infall of their parent interstellar clouds. Thus far, significant advances toward establishing the evolving surface density of such disks was made.

  8. Echocardiographic and clinical outcomes of central versus noncentral percutaneous edge-to-edge repair of degenerative mitral regurgitation

    DEFF Research Database (Denmark)

    Estévez-Loureiro, Rodrigo; Franzen, Olaf; Winter, Reidar;

    2013-01-01

    This study aimed to assess the clinical and echocardiographic results of MitraClip implantation in noncentral degenerative mitral regurgitation (dMR) compared with central dMR.......This study aimed to assess the clinical and echocardiographic results of MitraClip implantation in noncentral degenerative mitral regurgitation (dMR) compared with central dMR....

  9. Improving the thin-disk models of circumstellar disk evolution. The 2+1-dimensional model

    Science.gov (United States)

    Vorobyov, Eduard I.; Pavlyuchenkov, Yaroslav N.

    2017-09-01

    Context. Circumstellar disks of gas and dust are naturally formed from contracting pre-stellar molecular cores during the star formation process. To study various dynamical and chemical processes that take place in circumstellar disks prior to their dissipation and transition to debris disks, the appropriate numerical models capable of studying the long-term disk chemodynamical evolution are required. Aims: We improve the frequently used 2D hydrodynamical model for disk evolution in the thin-disk limit by employing a better calculation of the disk thermal balance and adding a reconstruction of the disk vertical structure. Together with the hydrodynamical processes, the thermal evolution is of great importance since it influences the strength of gravitational instability and the chemical evolution of the disk. Methods: We present a new 2+1-dimensional numerical hydrodynamics model of circumstellar disk evolution, where the thin-disk model is complemented with the procedure for calculating the vertical distributions of gas volume density and temperature in the disk. The reconstruction of the disk vertical structure is performed at every time step via the solution of the time-dependent radiative transfer equations coupled to the equation of the vertical hydrostatic equilibrium. Results: We perform a detailed comparison between circumstellar disks produced with our previous 2D model and with the improved 2+1D approach. The structure and evolution of resulting disks, including the differences in temperatures, densities, disk masses, and protostellar accretion rates, are discussed in detail. Conclusions: The new 2+1D model yields systematically colder disks, while the in-falling parental clouds are warmer. Both effects act to increase the strength of disk gravitational instability and, as a result, the number of gravitationally bound fragments that form in the disk via gravitational fragmentation as compared to the purely 2D thin-disk simulations with a simplified

  10. Traumatic plexus lesion.

    NARCIS (Netherlands)

    Dongen, R.T.M. van; Cohen, S.P.; Kleef, M. van; Mekhail, N.; Huygen, F.

    2011-01-01

    Pain, motor, and sensory deficits characterize patients with a traumatic lesion of the brachial plexus. Frequently, more severe injuries co-exist that require immediate surgical attention. Early rehabilitation and physical therapy are the cornerstones of treatment. Pharmacological management can be

  11. Immunopathology of skin lesions

    Directory of Open Access Journals (Sweden)

    Khan Nazoora

    2001-09-01

    Full Text Available A study was conducted on 130 patients suffering from skin lesions which included psoriasis, lichen planus, DLE, pemphigus, vitiligo and alopecia areata. Forty age-and-sex-matched healthy individuals served as control. Serum IgG, IgM, and circulating immune complexes (CIC were estimated. Significant increase in serum IgG (1937.2 ± 1030.43 mg% and IgM (232.12 ± 136.98 mg% was observed in all the skin lesions when compared with controls except in lichen planus where they were significantly lowered, values being 580.61± 77.35 mg% and 66.88 ± 6.59mg% respectively. CIC levels were significantly raised (P<0.00 1 in various skin lesions (40.49±23.29 when compared with controls (17.68± 3.21, but no significance was observed in lichen planus( 17.72 ± 4.28. Serum IgG, IgM and CIC were statistically significantly altered depending on the extent of the lesion and lowered significantly to almost normal values following treatment, thereby confirming the role of immunity in the pathogenesis of these skin disorders.

  12. Genital lesions following bestiality

    Directory of Open Access Journals (Sweden)

    Mittal A

    2000-01-01

    Full Text Available A 48-year-old man presented with painful genital lesions with history of bestiality and abnor-mal sexual behaviour. Examination revealed multiple irregular tender ulcers and erosions, with phimosis and left sided tender inguinal adenopathy. VDRL, TPHA, HIV-ELISA were negative. He was treated with ciprofloxacin 500mg b.d. along with saline compresses with complete resolution.

  13. White matter lesion progression

    DEFF Research Database (Denmark)

    Hofer, Edith; Cavalieri, Margherita; Bis, Joshua C;

    2015-01-01

    BACKGROUND AND PURPOSE: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants...

  14. Is risk of degenerative musculoskeletal conditions associated with pre-pregnancy body mass index and parity?

    DEFF Research Database (Denmark)

    Bliddal, Mette; Pottegård, Anton; Kirkegaard, Helene

    Background Obesity among women may influence the risk of degenerative musculoskeletal conditions (MSCs) and contribute to poor quality of life. Parity, which constitutes a sudden natural increase in weight as well it affects long-term body mass index (BMI), may put strain on the musculoskeletal s...

  15. The role of stem cell therapies in degenerative lumbar spine disease: a review.

    Science.gov (United States)

    Oehme, David; Goldschlager, Tony; Rosenfeld, Jeffrey V; Ghosh, Peter; Jenkin, Graham

    2015-07-01

    Degenerative conditions of the lumbar spine are extremely common. Ninety percent of people over the age of 60 years have degenerative change on imaging; however, only a small minority of people will require spine surgery (Hicks et al. Spine (Phila Pa 1976) 34(12):1301-1306, 2009). This minority, however, constitutes a core element of spinal surgery practice. Whilst the patient outcomes from spinal surgeries have improved in recent years, some patients will remain with pain and disability despite technically successful surgery. Advances in regenerative medicine and stem cell therapies, particularly the use of mesenchymal stem cells and allogeneic mesenchymal precursor cells, have led to numerous clinical trials utilising these cell-based therapies to treat degenerative spinal conditions. Through cartilage formation and disc regeneration, fusion enhancement or via modification of pain pathways, stem cells are well suited to enhance spinal surgery practice. This review will focus on the outcomes of lumbar spinal procedures and the role of stem cells in the treatment of degenerative lumbar conditions to enhance clinical practice. The current status of clinical trials utilising stem cell therapies will be discussed, providing clinicians with an overview of the various cell-based treatments likely to be available to patients in the near future.

  16. Clinical outcome of stand-alone ALIF compared to posterior instrumentation for degenerative disc disease

    DEFF Research Database (Denmark)

    Udby, Peter M.; Bech-Azeddine, Rachid

    2015-01-01

    low back pain resulting from degenerative disc disease. ALIF surgery has previously been linked with certain high risk complications and unfavorable long term fusion results. Newer studies suggest that stand-alone ALIF can possibly be advantageous compared to other types of posterior instrumented...

  17. Teaching Early Braille Literacy Skills within a Stimulus Equivalence Paradigm to Children with Degenerative Visual Impairments

    Science.gov (United States)

    Toussaint, Karen A.; Tiger, Jeffrey H.

    2010-01-01

    Despite the need for braille literacy, there has been little attempt to systematically evaluate braille-instruction programs. The current study evaluated an instructive procedure for teaching early braille-reading skills with 4 school-aged children with degenerative visual impairments. Following a series of pretests, braille instruction involved…

  18. Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases

    Directory of Open Access Journals (Sweden)

    Md. Asiful Islam

    2016-01-01

    Full Text Available Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA, diabetes mellitus (DM, and cardiovascular disease (CVD. Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described.

  19. No publication bias in industry funded clinical trials of degenerative diseases of the spine.

    Science.gov (United States)

    Son, Colin; Tavakoli, Samon; Bartanusz, Viktor

    2016-03-01

    Industry sponsorship of clinical research of degenerative diseases of the spine has been associated with excessive positive published results as compared to research carried out without industry funding. We sought the rates of publication of clinical trials of degenerative diseases of the spine based on funding source as a possible explanation for this phenomenon. We reviewed all clinical trials registered at clinicaltrials.gov relating to degenerative diseases of the spine as categorized under six medical subject heading terms (spinal stenosis, spondylolisthesis, spondylolysis, spondylosis, failed back surgery syndrome, intervertebral disc degeneration) and with statuses of completed or terminated. These collected studies were categorized as having, or not having, industry funding. Published results for these studies were then sought within the clinicaltrials.gov database itself, PubMed and Google Scholar. One hundred sixty-one clinical trials met these criteria. One hundred nineteen of these trials had industry funding and 42 did not. Of those with industry funding, 45 (37.8%) had identifiable results. Of those without industry funding, 17 (40.5%) had identifiable results. There was no difference in the rates of publication of results from clinical trials of degenerative diseases of the spine no matter the funding source.

  20. Comparing surgical repair with conservative treatment for degenerative rotator cuff tears : a randomized controlled trial

    NARCIS (Netherlands)

    Lambers Heerspink, Okke; van Raay, Jos J. A. M.; Koorevaar, Rinco C. T.; van Eerden, Pepijn J. M.; Westerbeek, Robin E.; van 't Riet, Esther; van den Akker-Scheek, Inge; Diercks, Ronald L.

    2015-01-01

    Background: Good clinical results have been reported for both surgical and conservative treatment of rotator cuff tears. The primary aim of this randomized controlled trial was to compare functional and radiologic improvement after surgical and conservative treatment of degenerative rotator cuff tea

  1. Temporomandibular degenerative joint disease. Part I. Anatomy, pathophysiology, and clinical description.

    Science.gov (United States)

    Kreutziger, K L; Mahan, P E

    1975-08-01

    The anatomy and function of the temporomandibular joint (TMJ) are described in the detail needed to evaluate and treat temporomandibular degenerative joint disease (TDJD). Innervation of the joint and the mechanism of arthralgia are described and related to TDJD. The clinical course of TDJD, radiographic evaluation of it, histopathologic description, and etiology are presented.

  2. Physiotherapy in degenerative cerebellar ataxias: utilisation, patient satisfaction, and professional expertise

    NARCIS (Netherlands)

    Fonteyn, E.M.R.; Keus, S.H.J.; Verstappen, C.C.P.; Warrenburg, B.P.C. van de

    2013-01-01

    Physiotherapy plays an important role in the management of patients with degenerative cerebellar ataxias. However, our insight in the quantity and quality of physiotherapy prescription in this group of patients is incomplete. The purposes of this study were to investigate the utilization of physioth

  3. Motor Training in Degenerative Spinocerebellar Disease: Ataxia-Specific Improvements by Intensive Physiotherapy and Exergames

    Directory of Open Access Journals (Sweden)

    Matthis Synofzik

    2014-01-01

    Full Text Available The cerebellum is essentially involved in movement control and plays a critical role in motor learning. It has remained controversial whether patients with degenerative cerebellar disease benefit from high-intensity coordinative training. Moreover, it remains unclear by which training methods and mechanisms these patients might improve their motor performance. Here, we review evidence from different high-intensity training studies in patients with degenerative spinocerebellar disease. These studies demonstrate that high-intensity coordinative training might lead to a significant benefit in patients with degenerative ataxia. This training might be based either on physiotherapy or on whole-body controlled videogames (“exergames”. The benefit shown in these studies is equal to regaining one or more years of natural disease progression. In addition, first case studies indicate that even subjects with advanced neurodegeneration might benefit from such training programs. For both types of training, the observed clinical improvements are paralleled by recoveries in ataxia-specific dysfunctions (e.g., multijoint coordination and dynamic stability. Importantly, for both types of training, the retention of the effects seems to depend on the frequency and continuity of training. Based on these studies, we here present preliminary recommendations for clinical practice, and articulate open questions that might guide future studies on neurorehabilitation in degenerative spinocerebellar disease.

  4. Comparing surgical repair with conservative treatment for degenerative rotator cuff tears : a randomized controlled trial

    NARCIS (Netherlands)

    Lambers Heerspink, Okke; van Raay, Jos J. A. M.; Koorevaar, Rinco C. T.; van Eerden, Pepijn J. M.; Westerbeek, Robin E.; van 't Riet, Esther; van den Akker-Scheek, Inge; Diercks, Ronald L.

    Background: Good clinical results have been reported for both surgical and conservative treatment of rotator cuff tears. The primary aim of this randomized controlled trial was to compare functional and radiologic improvement after surgical and conservative treatment of degenerative rotator cuff

  5. Lumbar spine degenerative disease : effect on bone mineral density measurements in the lumbar spine and femoral neck

    Energy Technology Data Exchange (ETDEWEB)

    Juhng, Seon Kwan [Wonkwang Univ. School of Medicine, Iksan (Korea, Republic of); Koplyay, Peter; Jeffrey Carr, J.; Lenchik, Leon [Wake Forest Univ. School of Medicine, Winston-salem (United States)

    2001-04-01

    To determine the effect of degenerative disease of the lumbar spine on bone mineral density in the lumbar spine and femoral neck. We reviewed radiographs and dual energy x-ray absorptiometry scans of the lumbar spine and hip in 305 Caucasian women with suspected osteoporosis. One hundred and eight-six patient remained after excluding women less than 40 years of age (n=18) and those with hip osteoarthritis, scoliosis, lumbar spine fractures, lumbar spinal instrumentation, hip arthroplasty, metabolic bone disease other than osteoporosis, or medications known to influence bone metabolism (n=101). On the basis of lumbar spine radiographs, those with absent/mild degenerative disease were assigned to the control group and those with moderate/severe degenerative disease to the degenerative group. Spine radiographs were evaluated for degenerative disease by two radiologists working independently; discrepant evaluations were resolved by consensus. Lumbar spine and femoral neck bone mineral density was compared between the two groups. Forty-five (24%) of 186 women were assigned to the degenerative group and 141 (76%) to the control group. IN the degenerative group, mean bone mineral density measured 1.075g/cm? in the spine and 0.788g/cm{sup 2} in the femoral neck, while for controls the corresponding figures were 0.989g/cm{sup 2} and 0.765g/cm{sup 2}. Adjusted for age, weight and height by means of analysis of variance, degenerative disease of the lumbar spine was a significant predictor of increased bone mineral density in the spine (p=0.0001) and femoral neck (p=0.0287). Our results indicate a positive relationship between degenerative disease of the lumbar spine and bone mineral density in the lumbar spine and femoral neck, and suggest that degenerative disease in that region, which leads to an intrinsic increase in bone mineral density in the femoral neck, may be a good negative predictor of osteoporotic hip fractures.

  6. Morel-Lavallee lesion

    Institute of Scientific and Technical Information of China (English)

    Li Hui; Zhang Fangjie; Lei Guanghua

    2014-01-01

    Objective To review current knowledge of the Morel-Lavallee lesion (MLL) to help clinicians become familiar with this entity.Familiarization may decrease missed diagnoses and misdiagnoses.It could also help steer the clinician to the proper treatment choice.Data sources A search was performed via PubMed and EMBASE from 1966 to July 2013 using the following keywords:Morel-Lavallee lesion,closed degloving injury,concealed degloving injury,Morel-Lavallee effusion,Morel-Lavallee hematoma,posttraumatic pseudocyst,posttraumatic soft tissue cyst.Study selection Chinese and English language literatures relevant to the subject were collected.Their references were also reviewed.Results Morel-Lavallee lesion is a relatively rare condition involving a closed degloving injury.It is characterized by a filled cystic cavity created by separation of the subcutaneous tissue from the underlying fascia.Apart from the classic location over the region of the greater trochanter,MLLs have been described in other parts of the body.The natural history of MLL has not yet been established.The lesion may decrease in volume,remain stable,enlarge progressively or show a recurrent pattern.Diagnosis of MLL was often missed or delayed.Ultrasonography,computed tomography,and magnetic resonance imaging have great value in the diagnosis of MLL.Treatment of MLL has included compression,local aspiration,open debridement,and sclerodesis.No standard treatment has been established.Conclusions A diagnosis of MLL should be suspected when a soft,fluctuant area of skin or chronic recurrent fluid collection is found in a region exposed to a previous shear injury.Clinicians and radiologists should be aware of both the acute and chronic appearances to make the correct diagnosis.Treatment decisions should base on association with fractures,the condition of the lesion,symptom and desire of the patient.

  7. The MRI appearance of cystic lesions around the knee

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, Catherine L.; McNally, Eugene G. [Department of Radiology, Nuffield Orthopaedic Centre, Windmill Road, OX3 7LD, Headington, Oxford (United Kingdom)

    2004-04-01

    This review presents a comprehensive illustrated overview of the wide variety of cystic lesions around the knee. The aetiology, clinical presentation, MRI appearances and differential diagnosis are discussed. Bursae include those related to the patella as well as pes anserine, tibial collateral ligament, semimembranosus-tibial collateral ligament, iliotibial and fibular collateral ligament-biceps femoris. The anatomical extension, imaging features and clinical significance of meniscal cysts are illustrated. Review of ganglia includes intra-articular, extra-articular, intraosseous and periosteal ganglia, highlighting imaging findings and differential diagnoses. The relationship between proximal tibiofibular joint cysts and intraneural peroneal nerve ganglia is discussed. Intraosseous cystic lesions, including insertional and degenerative cysts, as well as lesions mimicking cysts of the knee are described and illustrated. Knowledge of the location, characteristic appearance and distinguishing features of cystic masses around the knee as well as potential imaging pitfalls such as normal anatomical recesses and atypical cyst contents on MR imaging aids in allowing a specific diagnosis to be made. This will prevent unnecessary additional investigations and determine whether intra-articular surgery or conservative management is appropriate. (orig.)

  8. Imaging in spinal posterior epidural space lesions: A pictorial essay

    Directory of Open Access Journals (Sweden)

    Foram B Gala

    2016-01-01

    Full Text Available Spinal epidural space is a real anatomic space located outside the dura mater and within the spinal canal extending from foramen magnum to sacrum. Important contents of this space are epidural fat, spinal nerves, epidural veins and arteries. Due to close proximity of posterior epidural space to spinal cord and spinal nerves, the lesions present with symptoms of radiculopathy and/or myelopathy. In this pictorial essay, detailed anatomy of the posterior epidural space, pathologies affecting it along with imaging pearls to accurately diagnose them are discussed. Various pathologies affecting the posterior epidural space either arising from the space itself or occurring secondary to vertebral/intervertebral disc pathologies. Primary spinal bone tumors affecting the posterior epidural space have been excluded. The etiological spectrum affecting the posterior epidural space ranges from degenerative, infective, neoplastic - benign or malignant to miscellaneous pathologies. MRI is the modality of choice in evaluation of these lesions with CT scan mainly helpful in detecting calcification. Due to its excellent soft tissue contrast, Magnetic Resonance Imaging is extremely useful in assessing the pathologies of posterior epidural space, to know their entire extent, characterize them and along with clinical history and laboratory data, arrive at a specific diagnosis and guide the referring clinician. It is important to diagnose these lesions early so as to prevent permanent neurological complication.

  9. MR imaging of lipoma arborescens and the associated lesions

    Energy Technology Data Exchange (ETDEWEB)

    Vilanova, J.C.; Barcelo, J.; Villalon, M. [Magnetic Resonance Unit, Ressonancia Girona, Clinica Girona (Spain); Aldoma, J.; Delgado, E. [Centre Diagnostic Pedralbes, Barcelona (Spain); Zapater, I. [Dept. of Radiology, Hospital de Palamos, Palamos, Girona (Spain)

    2003-09-01

    Objective: To describe the typical features of lipoma arborescens on MR imaging with pathologic correlation and to evaluate the associated lesions within the joints. Design and patients: The MR imaging findings of 32 patients with the diagnosis of lipoma arborescens of the knee (n=32) and shoulder (n=1) were reviewed. The diagnosis of lipoma arborescens was confirmed by the histologic findings in 12 cases and the other 21 cases were diagnosed by the characteristic MR imaging features. One patient had bilateral lipoma arborescens of the knee joint. Results: MR imaging showed a typical pattern of villous lipomatous proliferation of the synovium in all cases, as a diffuse pattern in 79% (26/33) of cases and as a dominant mass-like lesion in 21% (7/33) of cases. The associated MR pathology in the knee was (n=32): joint effusion (100%), degenerative changes (87%), meniscal tear (72%), synovial cysts (38%), bone erosions (25%), chondromatosis (13%), patellar subluxation (6%) and discoid meniscus (3%). In all cases except two there was associated pathology of the knee. MR imaging showed an associated rotator cuff tear in the lipoma arborescens of the shoulder. Conclusion: The characteristic MR features of lipoma arborescens allows an accurate diagnosis of this rare lesion, which is almost always associated with other chronic pathology of the joint in the elderly. (orig.)

  10. Development of Powered Disk Type Sugar Cane Stubble Saver

    Directory of Open Access Journals (Sweden)

    Radite P.A.S.

    2009-04-01

    Full Text Available The objective of this research was to design, fabricate and test a prototype of sugar cane stubble saver based on powered disk mechanism. In this research, a heavy duty disk plow or disk harrow was used as a rotating knife to cut the sugarcane stubble. The parabolic disk was chosen because it is proven reliable as soil working tools and it is available in the market as spare part of disk plow or disk harrow unit. The prototype was mounted on the four wheel tractor’s three point hitch, and powered by PTO of the tractor. Two kinds of disks were used in these experiments, those were disk with regular edge or plain disk and disk with scalloped edge or scalloped disk. Both disks had diameter of 28 inch. Results of field test showed that powered disk mechanism could satisfy cut sugar cane’s stubble. However, scalloped disk type gave smoother stubble cuts compared to that of plain disk. Plain disk type gave broken stubble cut. Higher rotation (1000 rpm resulted better cuts as compared to lower rotation (500 rpm both either on plain disk and scalloped disk. The developed prototype could work below the soil surface at depth of 5 to 10 cm. With tilt angle setting 20O and disk angle 45O the width of cut was about 25 cm.

  11. Performance Considerations for Gigabyte per Second Transcontinental Disk-to-Disk File Transfers

    CERN Document Server

    Kukol, P; Kukol, Peter; Gray, Jim

    2005-01-01

    Moving data from CERN to Pasadena at a gigabyte per second using the next generation Internet requires good networking and good disk IO. Ten Gbps Ethernet and OC192 links are in place, so now it is simply a matter of programming. This report describes our preliminary work and measurements in configuring the disk subsystem for this effort. Using 24 SATA disks at each endpoint we are able to locally read and write an NTFS volume is striped across 24 disks at 1.2 GBps. A 32-disk stripe delivers 1.7 GBps. Experiments on higher performance and higher-capacity systems deliver up to 3.5 GBps.

  12. Scaling Ratios and Triangles in Siegel Disks

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    1999-01-01

    Let f(z)=e^{2i\\pi \\theta} + z^2, where \\theta is a quadratic irrational. McMullen proved that the Siegel disk for f is self-similar about the critical point, and we show that if \\theta = (\\sqrt{5}-1)/2 is the golden mean, then there exists a triangle contained in the Siegel disk, and with one...

  13. Simulating planet migration in globally evolving disks

    CERN Document Server

    Crida, A; Masset, F

    2006-01-01

    Numerical simulations of planet-disk interactions are usually performed with hydro-codes that -- because they consider only an annulus of the disk, over a 2D grid -- can not take into account the global evolution of the disk. However, the latter governs planetary migration of type II, so that the accuracy of the planetary evolution can be questioned. To develop an algorithm that models the local planet-disk interactions together with the global viscous evolution of the disk, we surround the usual 2D grid with a 1D grid ranging over the real extension of the disk. The 1D and 2D grids are coupled at their common boundaries via ghost rings, paying particular attention to the fluxes at the interface, especially the flux of angular momentum carried by waves. The computation is done in the frame centered on the center of mass to ensure angular momentum conservation. The global evolution of the disk and the local planet-disk interactions are both well described and the feedback of one on the other can be studied wit...

  14. A Primer on Unifying Debris Disk Morphologies

    Science.gov (United States)

    Lee, Eve J.; Chiang, Eugene

    2016-08-01

    A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

  15. Capillary condensation between disks in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial capi....... The theory can be applied to the description of flocculations in two-dimensional systems of colloids....

  16. Protoplanetary disks and exoplanets in scattered light

    NARCIS (Netherlands)

    Stolker, T.

    2017-01-01

    High-contrast imaging facilitates the direct detection of protoplanetary disks in scattered light and self-luminous exoplanets on long-period orbits. The combined power of extreme adaptive optics and differential imaging techniques delivers high spatial resolution images of disk morphologies down to

  17. 10 MB disk platter from CDC 7638

    CERN Multimedia

    1974-01-01

    This magnetic disk was one of three which interfaced with various Control Data machines. This single platter came from a Control Data 7638 Disk Storage Subsystem and could contain up to 10MB - about the size of a few MP4's on your iPod.

  18. The Transitional Disks Associated With Herbig Stars

    Science.gov (United States)

    Grady, C.; Fukagawa, M.; Maruta, Y.; Ohta, Y.; Wisniewski, J.; Lomax, J.; Hashimoto, J.; Currie, T.; Okamoto, Y.; Momose, M.; McElwain, M.

    2015-01-01

    As part of the Strategic Exploration of Exoplanets and Disks with Subaru YSO survey, we have surveyed a number of Herbig B-F stars mainly at H-band using Polarimetric Differential Imaging + Angular differential imaging. Historically, Herbig stars have been sorted by the shape of the IR SEDs into those which can be fit by power laws over 1-200 micrometers (Meeus et al. 2001, group II), and those which can be interpreted as a power law + a blackbody component (Meeus group I) or as transitional or pre-transitional disks (Maaskant et al. 2013). Meeus group II disks, when imaged with HiCIAO show featureless disks with depolarization along the projection of the disk semi-minor axis (Kusakabe et al. 2012). This is what we had expected to see for the Meeus group I disks, except for the addition of wide gaps or central cavities. Instead we find wild diversity, suggesting that transitional disks are highly perturbed compared to Meeus group II disks. To date, similar structure continues to be observed as higher Strehl ratio imagery becomes available.

  19. Chemical history of molecules in circumstellar disks

    CERN Document Server

    Visser, Ruud; Doty, Steven D

    2011-01-01

    The chemical composition of a protoplanetary disk is determined not only by in situ chemical processes during the disk phase, but also by the history of the gas and dust before it accreted from the natal envelope. In order to understand the disk's chemical composition at the time of planet formation, especially in the midplane, one has to go back in time and retrace the chemistry to the molecular cloud that collapsed to form the disk and the central star. Here we present a new astrochemical model that aims to do just that. The model follows the core collapse and disk formation in two dimensions, which turns out to be a critical upgrade over older collapse models. We predict chemical stratification in the disk due to different physical conditions encountered along different streamlines. We argue that the disk-envelope accretion shock does not play a significant role for the material in the disk at the end of the collapse phase. Finally, our model suggests that complex organic species are formed on the grain su...

  20. Early Phases of Protoplanetary Disk Evolution

    NARCIS (Netherlands)

    Kamp, Inga; Macchetto, FD

    2010-01-01

    It is widely accepted that planetary systems form from protoplanetary disks, and observations of the dust reveal significant grain growth over timescales of a few million years. However, we know little about the gas processing in the first 10-20 Myr of disk evolution. This is the phase where protopl

  1. Circular plate capacitor with different disks

    CERN Document Server

    Paffuti, Giampiero; Di Lieto, Alberto; Maccarrone, Francesco

    2016-01-01

    In this paper we write a system of integral equations for a capacitor composed by two disks of different radii, generalizing Love's equation for equal disks. We compute the complete asymptotic form of the capacitance matrix both for large and small distances obtaining a generalization of Kirchhoff's formula for the latter case.

  2. Molecular gas in young debris disks

    CERN Document Server

    Moór, A; Juhász, A; Kiss, Cs; Pascucci, I; Kóspál, Á; Apai, D; Henning, Th; Csengeri, T; Grady, C

    2011-01-01

    Gas-rich primordial disks and tenuous gas-poor debris disks are usually considered as two distinct evolutionary phases of the circumstellar matter. Interestingly, the debris disk around the young main-sequence star 49 Ceti possesses a substantial amount of molecular gas, and possibly represents the missing link between the two phases. Motivated to understand the evolution of the gas component in circumstellar disks via finding more 49 Ceti-like systems, we carried out a CO J=3-2 survey with Atacama Pathfinder EXperiment, targeting 20 infrared-luminous debris disks. These systems fill the gap between primordial and old tenuous debris disks in terms of fractional luminosity. Here we report on the discovery of a second 49 Ceti-like disk around the 30 Myr old A3-type star HD21997, a member of the Columba Association. This system was also detected in the CO(2-1) transition, and the reliable age determination makes it an even clearer example of an old gas-bearing disk than 49 Ceti. While the fractional luminosities...

  3. Ancient bronze disks, decorations and calendars

    CERN Document Server

    Sparavigna, Amelia Carolina

    2012-01-01

    Recently, it was published that some ancient bronze disks could had been calendars, that is, that their decorations had this function. Here I am discussing an example, the disk of the Trundholm Sun Chariot, proposing a new interpretation of it, giving a calendar of 360 days. Some geometric diagrams concerning the decoration layout are also proposed.

  4. Snow Line Localization in Classical Protoplanetary Disks

    Science.gov (United States)

    Blevins, S.

    2014-04-01

    Protoplanetary disks are volatile-rich environments capable of producing the essential conditions that make planet formation viable. Establishing a molecular inventory of dominant volatile species, such as water, in the planet-forming zones surrounding young, solar-type stars elevates our understanding of the chemistry involved with planet formation, composition and disk evolution. For this study we measure the water vapor content and determine the location of the condensation front, or snow line, for four classical disks selected for the strong water emission present in their mid-infrared spectra. To accomplish this we combine deep Herschel PACS observations with high resolution Spitzer IRS spectra to create molecular maps comprised of water lines with excitation temperatures that trace the disks' surfaces from 1-100 AU. We use two-dimensional, axisymmetric radiative transfer modeling to retrieve the disks' dust structures and the RADLite raytracer to render model spectra for each disk. A simple step function is used to define the abundance structure and the model spectra are fit to the observed water lines. Preliminary results will be discussed, including the inner disk chemical content, snow line radius and fractional water vapor abundances for the classical disk RNO 90.

  5. Complications and outcomes of surgery for degenerative lumbar deformity in elderly patients

    Directory of Open Access Journals (Sweden)

    Kim HJ

    2013-12-01

    Full Text Available Hyo Jong Kim, Kyu Yeol Lee, Lih WangDepartment of Orthopaedic Surgery, College of Medicine, Dong-A University, Busan, KoreaBackground: The purpose of this study was to analyze the complications, clinical outcomes, and any correlative risk factors associated with degenerative lumbar deformity surgery in elderly patients.Methods: We reviewed 78 patients who underwent posterior decompression and posterolateral fusion requiring a minimum three-level fusion for degenerative lumbar deformity associated with spinal stenosis between May 2001 and May 2006, with at least a one-year follow-up period. We assessed and compared the postoperative complications and clinical outcomes for patients aged 65 years and over (group A and patients aged 50–64 years (group B. Risk factors that could influence complications and clinical outcome were evaluated and statistically analyzed.Results: The postoperative complication rate was not significantly different between the two age groups (53% in group A and 40% in group B; however, group A had a significantly higher frequency of minor complications than group B, especially for urinary retention and postoperative delirium. A statistical relationship between diabetes mellitus and deep wound infection, one of the major complications of degenerative lumbar deformity surgery, was observed in both group A and group B. Male sex was a risk factor for urinary retention and long operative time, and abundant blood loss was a significant risk factor for postoperative delirium in group A.Conclusion: There were no significant differences in results for degenerative lumbar deformity surgery between patients older and younger than 65 years. However, diabetes mellitus showed a significant correlation with deep wound infection, which is one of the major complications of degenerative lumbar deformity surgery, and with urinary retention and postoperative delirium, which occurred frequently in patients aged older than 65 years

  6. Outcomes and Complications of Diabetes Mellitus on Patients Undergoing Degenerative Lumbar Spine Surgery

    Science.gov (United States)

    Guzman, Javier Z.; Iatridis, James C.; Skovrlj, Branko; Cutler, Holt; Hecht, Andrew C.; Qureshi, Sheeraz A.; Cho, Samuel K.

    2014-01-01

    Study Design Retrospective database analysis. Objective To assess the effect glycemic control has on perioperative morbidity and mortality in patients undergoing elective degenerative lumbar spine surgery. Summary of background data Diabetes Mellitus (DM) is a prevalent disease of glucose dysregulation that has been demonstrated to increase morbidity and mortality following spine surgery. However, there is limited understanding of whether glycemic control influences surgical outcomes in DM patients undergoing lumbar spine procedures for degenerative conditions. Methods The Nationwide Inpatient Sample was analyzed from 2002 to 2011. Hospitalizations were isolated based on International Classification of Diseases Ninth Revision, Clinical Modification procedural codes for lumbar spine surgery and diagnoses codes for degenerative conditions of the lumbar spine. Patients were then classified into three cohorts: controlled diabetics, uncontrolled diabetics and non-diabetics. Patient demographic data, acute complications and hospitalization outcomes were determined for each cohort. Results A total of 403,629 (15.7%) controlled diabetics and 19,421(0.75%) uncontrolled diabetics underwent degenerative lumbar spine surgery from 2002-2011. Relative to non-diabetics, uncontrolled diabetics had significantly increased odds of cardiac complications, deep venous thrombosis and post-operative shock; additionally, uncontrolled diabetics also had an increased mean length of stay (approximately 2.5 days), greater costs (1.3-fold) and a greater risk of inpatient mortality (odds ratio=2.6, 95% confidence interval=1.5-4.8, p degenerative lumbar spine surgery leads to increased risk of acute complications and poor outcomes. Patients with uncontrolled DM, or poor glucose control, may benefit from improving glycemic control prior to surgery. PMID:24983935

  7. Congenital Cervical Fusion as a Risk Factor for Development of Degenerative Cervical Myelopathy.

    Science.gov (United States)

    Nouri, Aria; Martin, Allan R; Lange, Stefan F; Kotter, Mark R N; Mikulis, David J; Fehlings, Michael G

    2017-04-01

    Congenital fusion of cervical vertebrae, including Klippel-Feil syndrome (KFS), is a suspected risk factor for development of degenerative cervical myelopathy (DCM). We aimed to establish prevalence and degenerative patterns of congenital cervical fusion (CCF) among a global cohort of patients with DCM. Data from 3 prospective DCM studies were merged, including clinical data for 813 patients and imaging for 592 patients. CCF was diagnosed by presence of fused cervical vertebrae without signs of degenerative fusion. A wasp-waist sign was used to define a KFS subgroup. Characteristics of patients with CCF and the KFS subgroup were compared with the remainder of patients with DCM. Twenty-three patients with CCF (14 KFS) were identified, indicating a prevalence of 3.9% (2.4% KFS). Patients with CCF were older (P = 0.02), had more operated levels (P = 0.01), had higher rates of ossified posterior longitudinal ligament (P = 0.02), and demonstrated worse degenerative changes at C3-4, including spinal cord compression (P = 0.002) and T2 weighted image T2WI signal hyperintensity (P = 0.04). Levels adjacent to fusions showed a trend toward increased spinal cord compression (P = 0.09), with fusions at C3-4 or above showing cord compression below in 9 of 10 patients, fusions at C5-6 or below having cord compression above in 8 of 8 patients, and fusions at C4-5 showed cord compression above and below in 2 of 2 patients. The prevalence of CCF and KFS is higher in DCM than for the general population, suggesting that these patients are predisposed to DCM development. Patients with CCF also have an altered pattern of degenerative changes, seemingly related to adjacent segment degeneration that preferentially affects midcervical levels. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Diffusion tensor imaging differentiates vascular parkinsonism from parkinsonian syndromes of degenerative origin in elderly subjects

    Energy Technology Data Exchange (ETDEWEB)

    Deverdun, Jérémy [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Laboratoire Charles Coulomb, CNRS UMR 5221 - Université Montpellier II, Montpellier (France); I2FH, Institut d’Imagerie Fonctionnelle Humaine, Hôpital Gui de Chauliac, CHRU de, Montpellier (France); Menjot de Champfleur, Sophie [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Clinique du Parc, Castelnau-le-Lez (France); Cabello-Aguilar, Simon [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); I2FH, Institut d’Imagerie Fonctionnelle Humaine, Hôpital Gui de Chauliac, CHRU de, Montpellier (France); Maury, Florence [Department of Neurology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Molino, François [Laboratoire Charles Coulomb, CNRS UMR 5221 - Université Montpellier II, Montpellier (France); Institut de Génomique Fonctionnelle, UMR 5203 - INSERM U661 - Université Montpellier II - Université, Montpellier I (France); Charif, Mahmoud [Department of Neurology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Leboucq, Nicolas [Department of Neuroradiology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); Ayrignac, Xavier; Labauge, Pierre [Department of Neurology, Montpellier University Hospital Center, Gui de Chauliac Hospital, Montpellier (France); and others

    2014-11-15

    Background and Purpose: The etiologic diagnosis of parkinsonian syndromes is of particular importance when considering syndromes of vascular or degenerative origin. The purpose of this study is to find differences in the white-matter architecture between those two groups in elderly patients. Materials and Methods: Thirty-five patients were prospectively included (multiple-system atrophy, n = 5; Parkinson's disease, n = 15; progressive supranuclear palsy, n = 9; vascular parkinsonism, n = 6), with a mean age of 76 years. Patients with multiple-system atrophy, progressive supranuclear palsy and Parkinson's disease were grouped as having parkinsonian syndromes of degenerative origin. Brain MRIs included diffusion tensor imaging. Fractional anisotropy and mean-diffusivity maps were spatially normalized, and group analyses between parkinsonian syndromes of degenerative origin and vascular parkinsonism were performed using a voxel-based approach. Results: Statistical parametric-mapping analysis of diffusion tensor imaging data showed decreased fractional anisotropy value in internal capsules bilaterally in patients with vascular parkinsonism compared to parkinsonian syndromes of degenerative origin (p = 0.001) and showed a lower mean diffusivity in the white matter of the left superior parietal lobule (p = 0.01). Fractional anisotropy values were found decreased in the middle cerebellar peduncles in multiple-system atrophy compared to Parkinson's disease and progressive supranuclear palsy. The mean diffusivity was increased in those regions for these subgroups. Conclusion: Clinically defined vascular parkinsonism was associated with decreased fractional anisotropy in the deep white matter (internal capsules) compared to parkinsonian syndromes of degenerative origin. These findings are consistent with previously published neuropathological data.

  9. MHD Turbulence in Accretion Disk Boundary Layers

    CERN Document Server

    Chan, Chi-kwan

    2012-01-01

    The physical modeling of the accretion disk boundary layer, the region where the disk meets the surface of the accreting star, usually relies on the assumption that angular momentum transport is opposite to the radial angular frequency gradient of the disk. The standard model for turbulent shear viscosity, widely adopted in astrophysics, satisfies this assumption by construction. However, this behavior is not supported by numerical simulations of turbulent magnetohydrodynamic (MHD) accretion disks, which show that angular momentum transport driven by the magnetorotational instability is inefficient in this inner disk region. I will discuss the results of a recent study on the generation of hydromagnetic stresses and energy density in the boundary layer around a weakly magnetized star. Our findings suggest that although magnetic energy density can be significantly amplified in this region, angular momentum transport is rather inefficient. This seems consistent with the results obtained in numerical simulations...

  10. Magnetic fields in early protostellar disk formation

    CERN Document Server

    González-Casanova, Diego F; Lazarian, Alexander

    2016-01-01

    We consider formation of accretion disks from a realistically turbulent molecular gas using 3D MHD simulations. In particular, we analyze the effect of the fast turbulent reconnection described by the Lazarian & Vishniac (1999) model for the removal of magnetic flux from a disk. With our numerical simulations we demonstrate how the fast reconnection enables protostellar disk formation resolving the so-called "magnetic braking catastrophe". In particular, we provide a detailed study of the dynamics of a 0.5 M$_\\odot$ protostar and the formation of its disk for up to several thousands years. We measure the evolution of the mass, angular momentum, magnetic field, and turbulence around the star. We consider effects of two processes that strongly affect the magnetic transfer of angular momentum, both of which are based on turbulent reconnection: the first, "reconnection diffusion", removes the magnetic flux from the disk, the other involves the change of the magnetic field's topology, but does not change the a...

  11. From disks to planets: observational insights

    Science.gov (United States)

    Isella, Andrea

    The unprecedented sensitivity and imaging capabilities offered by the Atacama Large Millimeter Array (ALMA) are transforming our understanding of protoplanetary disks and, hence, of planet formation. In this brief chapter, I first discuss the main results and caveats related to the measurement of the mass of solids in protoplanetary disks based on millimeter-wave observations. I then present a recent analysis of the ALMA observations of the HL Tau disk, which suggests that the observed circular rings might be due to the tidal interaction between Saturn mass planets and the circumstellar material. In the conclusion, I argue that the existing observations of protoplanetary disks suggest that planets might form very early on, perhaps at the same time as the formation of the disk itself.

  12. Gravitational Instabilities in Disks with Radiative Cooling

    CERN Document Server

    Mejia, A C; Pickett, M K; Mej\\'ia, Annie C.; Durisen, Richard H.; Pickett, Megan K.

    2003-01-01

    Previous simulations of self-gravitating protostellar disks have shown that, once developed, gravitational instabilities are enhanced by cooling the disk constantly during its evolution (Pickett et al. 2002). These earlier calculations included a very simple form of volumetric cooling, with a constant cooling time throughout the disk, which acted against the stabilizing effects of shock heating. The present work incorporates more realistic treatments of energy transport. The initial disk model extends from 2.3 to 40 AU, has a mass of 0.07 Msun and orbits a 0.5 Msun star. The models evolve for a period of over 2500 years, during which extensive spiral arms form. The disks structure is profoundly altered, transient clumps form in one case, but no permanent bound companion objects develop.

  13. Structures of magnetized thin accretion disks

    Institute of Scientific and Technical Information of China (English)

    LI; xiaoqing(李晓卿); JI; Haisheng(季海生)

    2002-01-01

    We investigate the magnetohydrodynamic (MHD) process in thin accretion disks. Therelevant momentum as well as magnetic reduction equations in the thin disk approximation areincluded. On the basis of these equations, we examine numerically the stationary structures, includingdistributions of the surface mass density, temperature and flow velocities of a disk around a youngstellar object (YSO). The numerical results are as follows: (i) There should be an upper limit to themagnitude of magnetic field, such an upper limit corresponds to the equipartition field. For relevantmagnitude of magnetic field of the disk's interior the disk remains approximately Keplerian. (ii) Thedistribution of effective temperature T(r) is a smoothly decreasing function of radius with power 1 corresponding to the observed radiation flux density, provided that the magnetic fieldindex γ= -1/2,is suitably chosen.

  14. Reverberation Mapping of AGN Accretion Disks

    Science.gov (United States)

    Fausnaugh, Michael; AGN STORM Collaboration

    2017-01-01

    I will discuss new reverberation mapping results that allow us to investigate the temperature structure of AGN accretion disks. By measuring time-delays between broad-band continuum light curves, we can determine the size of the disk as a function of wavelength. I will discuss the detection of continuum lags in NGC 5548 reported by the AGN STORM project and implications for the accretion disk. I will also present evidence for continuum lags in two other AGN for which we recently measured black hole masses from continuum-Hbeta reverberations. The mass measurements allow us to compare the continuum lags to predictions from standard thin disk theory, and our results indicate that the accretion disks are larger than the simplest expectations.

  15. The WEAVE disk dynamics survey

    Science.gov (United States)

    Famaey, B.; Antoja, T.; Romero-Gomez, M.; Siebert, A.; Babusiaux, C.; Di Matteo, P.; Figueras, F.; Fragkoudi, F.; Garzon-Lopez, F.; Gonzalez-Fernandez, C.; Martinez-Valpuesta, I.; Monari, G.; Mor-Crespo, R.; Hill, V.

    2016-12-01

    WEAVE is the next-generation wide-field survey facility for the William Herschel Telescope. It consists of a multi-object fibre spectrograph with a 2°-diameter field of view that can obtain ˜ 1000 spectra simultaneously. The "WEAVE Galactic Archaeology survey" is the survey focused on the Milky Way, as a complement to the Gaia space mission, and will start operating in early 2018. This survey is subdivided in four sub-surveys, among which the "WEAVE disk dynamics survey". This survey plans to measure the radial velocities (and abundances as far as possible) of ˜ 10^6 stars with magnitude 15speed? -, as well as (iii) about their influence on secular processes such as stellar radial migration are essential elements for a better understanding of the chemo-dynamical evolution of our Galaxy, and of galaxies in general. This survey is designed to answer these questions.

  16. Streaming Instabilities in Protoplanetary Disks

    CERN Document Server

    Youdin, A N; Youdin, Andrew N.; Goodman, Jeremy

    2004-01-01

    Interpenetrating streams of solids and gas in a Keplerian disk produce a local, linear instability. The two components mutually interact via aerodynamic drag, which generates radial drift and triggers unstable modes. The secular instability does not require self-gravity, yet it generates growing particle density perturbations that could seed planetesimal formation. Growth rates are slower than dynamical, but faster than radial drift, timescales. Growth rates, like streaming velocities, are maximized for marginal coupling (stopping times comparable dynamical times). Fastest growth occurs when the solid to gas density ratio is order unity and feedback is strongest. Curiously, growth is strongly suppressed when the densities are too nearly equal. The relation between background drift and wave properties is explained by analogy with Howard's semicircle theorem. The three-dimensional, two-fluid equations describe a sixth order (in the complex frequency) dispersion relation. A terminal velocity approximation allows...

  17. Experiments with the Secchi disk

    Science.gov (United States)

    Aas, E.; Høkedal, J.; Sørensen, K.

    2013-10-01

    The Secchi depth and its relationships to other properties of the sea water in the Oslofjord-Skagerrak area have been investigated. White and black disks of different sizes have been applied, and the Secchi depth has been observed with the naked eye, through colour filters and with a water telescope. Spectral luminances and illuminances have been calculated from recordings of radiance and irradiance. A theoretical expression for the Secchi depth has been tested against field observations, and statistical relationships between Secchi depths and attenuation coefficients have been determined. Effects of size, colour filters, sun glitter and ship shadow have been quantified. The possibility to estimate quanta irradiance, chlorophyll a and total suspended material has also been studied.

  18. [Managing focal incidental renal lesions].

    Science.gov (United States)

    Nicolau, C; Paño, B; Sebastià, C

    2016-01-01

    Incidental renal lesions are relatively common in daily radiological practice. It is important to know the different diagnostic possibilities for incidentally detected lesions, depending on whether they are cystic or solid. The management of cystic lesions is guided by the Bosniak classification. In solid lesions, the goal is to differentiate between renal cancer and benign tumors such as fat-poor angiomyolipoma and oncocytoma. Radiologists need to know the recommendations for the management of these lesions and the usefulness of the different imaging techniques and interventional procedures in function of the characteristics of the incidental lesion and the patient's life expectancy.

  19. Disk-loss and Disk-renewal Phases in Classical Be Stars. II. Contrasting with Stable and Variable Disks

    Science.gov (United States)

    Draper, Zachary H.; Wisniewski, John P.; Bjorkman, Karen S.; Meade, Marilyn R.; Haubois, Xavier; Mota, Bruno C.; Carciofi, Alex C.; Bjorkman, Jon E.

    2014-05-01

    Recent observational and theoretical studies of classical Be stars have established the utility of polarization color diagrams (PCDs) in helping to constrain the time-dependent mass decretion rates of these systems. We expand on our pilot observational study of this phenomenon, and report the detailed analysis of a long-term (1989-2004) spectropolarimetric survey of nine additional classical Be stars, including systems exhibiting evidence of partial disk-loss/disk-growth episodes as well as systems exhibiting long-term stable disks. After carefully characterizing and removing the interstellar polarization along the line of sight to each of these targets, we analyze their intrinsic polarization behavior. We find that many steady-state Be disks pause at the top of the PCD, as predicted by theory. We also observe sharp declines in the Balmer jump polarization for later spectral type, near edge-on steady-state disks, again as recently predicted by theory, likely caused when the base density of the disk is very high, and the outer region of the edge-on disk starts to self absorb a significant number of Balmer jump photons. The intrinsic V-band polarization and polarization position angle of γ Cas exhibits variations that seem to phase with the orbital period of a known one-armed density structure in this disk, similar to the theoretical predictions of Halonen & Jones. We also observe stochastic jumps in the intrinsic polarization across the Balmer jump of several known Be+sdO systems, and speculate that the thermal inflation of part of the outer region of these disks could be responsible for producing this observational phenomenon. Finally, we estimate the base densities of this sample of stars to be between ≈8 × 10-11 and ≈4 × 10-12 g cm-3 during quasi steady state periods given there maximum observed polarization.

  20. Disk-loss and disk-renewal phases in classical Be stars. II. Contrasting with stable and variable disks

    Energy Technology Data Exchange (ETDEWEB)

    Draper, Zachary H. [Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Rd, Victoria, BC V8P 5C2 (Canada); Wisniewski, John P. [HL Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St, Norman, OK 73019 (United States); Bjorkman, Karen S.; Bjorkman, Jon E. [Ritter Observatory, Department of Physics and Astronomy, Mail Stop 113, University of Toledo, Toledo, OH 43606 (United States); Meade, Marilyn R. [Space Astronomy Lab, University of Wisconsin-Madison, 1150 University Avenue, Madison, WI 53706 (United States); Haubois, Xavier; Mota, Bruno C.; Carciofi, Alex C., E-mail: wisniewski@ou.edu, E-mail: karen.bjorkman@utoledo.edu, E-mail: jon@physics.utoledo.edu, E-mail: meade@astro.wisc.edu, E-mail: xhaubois@astro.iag.usp.br, E-mail: carciofi@usp.br [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universitária de São Paulo, Rua do Matão 1226, Cidade Universitária, 05508-900 São Paulo, SP (Brazil)

    2014-05-10

    Recent observational and theoretical studies of classical Be stars have established the utility of polarization color diagrams (PCDs) in helping to constrain the time-dependent mass decretion rates of these systems. We expand on our pilot observational study of this phenomenon, and report the detailed analysis of a long-term (1989-2004) spectropolarimetric survey of nine additional classical Be stars, including systems exhibiting evidence of partial disk-loss/disk-growth episodes as well as systems exhibiting long-term stable disks. After carefully characterizing and removing the interstellar polarization along the line of sight to each of these targets, we analyze their intrinsic polarization behavior. We find that many steady-state Be disks pause at the top of the PCD, as predicted by theory. We also observe sharp declines in the Balmer jump polarization for later spectral type, near edge-on steady-state disks, again as recently predicted by theory, likely caused when the base density of the disk is very high, and the outer region of the edge-on disk starts to self absorb a significant number of Balmer jump photons. The intrinsic V-band polarization and polarization position angle of γ Cas exhibits variations that seem to phase with the orbital period of a known one-armed density structure in this disk, similar to the theoretical predictions of Halonen and Jones. We also observe stochastic jumps in the intrinsic polarization across the Balmer jump of several known Be+sdO systems, and speculate that the thermal inflation of part of the outer region of these disks could be responsible for producing this observational phenomenon. Finally, we estimate the base densities of this sample of stars to be between ≈8 × 10{sup –11} and ≈4 × 10{sup –12} g cm{sup –3} during quasi steady state periods given there maximum observed polarization.

  1. Are all flaring Herbig disks transitional?

    Science.gov (United States)

    Maaskant, K. M.; Honda, M.; Waters, L. B. F. M.; Tielens, A. G. G. M.; Dominik, Carsten; Min, M.; Verhoeff, A.; Meeus, G.; Ancker, M. E.

    2013-07-01

    Context: The evolution of young massive protoplanetary disks toward planetary systems is expected to correspond to structural changes in observational appearance, which includes the formation of gaps and the depletion of dust and gas. Aims. A special group of disks around Herbig Ae/Be stars do not show prominent silicate emission features, although they still bear signs of flaring disks, the presence of gas, and small grains. We focus our attention on four key Herbig Ae/Be stars to understand the structural properties responsible for the absence of silicate feature emission. Methods: We investigate Q- and N-band images taken with Subaru/COMICS, Gemini South/T-ReCS, and VLT/VISIR. We perform radiative transfer modeling to examine the radial distribution of dust and polycyclic aromatic hydrocarbons (PAHs). Our solutions require a separation of inner- and outer- disks by a large gap. From this, we characterize the radial density structure of dust and PAHs in the disk. Results: The inner edge of the outer disk has a high surface brightness and a typical temperature between ˜100-150 K and therefore, dominates the emission in the Q-band. All four disks are characterized by large gaps. We derive radii of the inner edge of the outer disk of 34+4 , 23+3 , 30+5 and 63+4 AU for HD 97048, HD 169142, HD 135344 B, and Oph IRS 48, respectively. For HD 97048 this is the first -4 -5 -3 -4 detection of a disk gap. The large gaps deplete the entire population of silicate particles with temperatures suitable for prominent mid- infrared feature emission, while small carbonaceous grains and PAHs can still show prominent emission at mid-infrared wavelengths. The continuum emission in the N-band is not due to emission in the wings of PAHs. This continuum emission can be due to very small grains or to thermal emission from the inner disk. We find that PAH emission is not always dominated by PAHs on the surface of the outer disk. Conclusions: The absence of silicate emission features is

  2. Lesiones en el deporte

    Directory of Open Access Journals (Sweden)

    Rubio Gimeno, Silvio

    2000-02-01

    Full Text Available Not available

    El incremento de la actividad física y del deporte, en las sociedades llamadas desarrolladas, ha traído consigo beneficios claros para la salud, reflejados en diferentes indicadores de salud. Simultáneamente, el deporte de competición obliga a una dedicación diaria a intensidad de entrenamiento, con objeto de obtener los elevados requerimientos físicos que exige la competición. Todo ello ha traído consigo la aparición de numerosas lesiones, fundamentalmente del sistema músculo- esquelético.
    Se exponen en este trabajo consideraciones históricas, la epidemiología de la lesión deportiva y se describen, concisamente, algunas de las lesiones más habituales y significativas que afectan a músculos, tendones y sistema esquelético.

  3. Degenerative dementia: nosological aspects and results of single photon emission computed tomography; Les demences degeneratives: aspects nosologiques et resultats de la tomographie d'emission monophotonique

    Energy Technology Data Exchange (ETDEWEB)

    Dubois, B.; Habert, M.O. [Hopital Pitie-Salpetriere, 75 - Paris (France)

    1999-12-01

    Ten years ago, the diagnosis discussion of a dementia case for the old patient was limited to two pathologies: the Alzheimer illness and the Pick illness. During these last years, the frame of these primary degenerative dementia has fallen into pieces. The different diseases and the results got with single photon emission computed tomography are discussed. for example: fronto-temporal dementia, primary progressive aphasia, progressive apraxia, visio-spatial dysfunction, dementia at Lewy's bodies, or cortico-basal degeneration. (N.C.)

  4. Meniscal Ramp Lesions

    OpenAIRE

    2016-01-01

    Meniscal ramp lesions are more frequently associated with anterior cruciate ligament (ACL) injuries than previously recognized. Some authors suggest that this entity results from disruption of the meniscotibial ligaments of the posterior horn of the medial meniscus, whereas others support the idea that it is created by a tear of the peripheral attachment of the posterior horn of the medial meniscus. Magnetic resonance imaging (MRI) scans have been reported to have a low sensitivity, ...

  5. An unexpected lumbar lesion

    Directory of Open Access Journals (Sweden)

    Laura Beard

    2016-01-01

    Full Text Available This case report details an interesting case of suspected spinal bifida in an obstetric patient who presented for an elective cesarean section. A large scarred/dimpled area, surrounded by significant hair growth in the region of the lumbar spine had been missed in multiple antenatal and preoperative assessments and was recognized on the day of the surgery as the patient was being prepared for spinal anesthesia. The patient was uncertain regarding the pathology of the lesion, and all investigations relating to this had been undertaken in Pakistan where she lived as a child. General anesthesia was undertaken because magnetic resonance imaging had not been performed and tethering of the spinal cord could not be ruled out clinically. The patient suffered from significant blood loss intra and postoperatively, requiring a two unit blood transfusion. She was discharged after 5 days in the hospital. This case highlights the need for thorough examination in all obstetric patients presenting to the preoperative clinic, focusing on the airway, vascular access, and lumbar spine. Patients may not always disclose certain information due to a lack of understanding, embarrassment, forgetfulness, or language barriers. Significant aspects of their care may have been undertaken abroad and access to these notes is often limited. Preoperative detection of the lesion would have allowed further investigation and imaging of the lesion and enabled more comprehensive discussions with the patient regarding anesthetic options and risk.

  6. Warped Circumbinary Disks in Active Galactic Nuclei

    CERN Document Server

    Hayasaki, Kimitake; Okazaki, Atsuo T; Jung, Taehyun; Zhao, Guangyao; Naito, Tsuguya

    2014-01-01

    We study a warping instability of a geometrically thin, non-self-gravitating disk surrounding binary supermassive black holes on a circular orbit. Such a circumbinary disk is subject to not only tidal torques due to the binary gravitational potential but also radiative torques due to radiation emitted from an accretion disk around each black hole. We find that a circumbinary disk initially aligned with the binary orbital plane is unstable to radiation-driven warping beyond the marginally stable warping radius, which is sensitive to both the ratio of vertical to horizontal shear viscosities and the mass-to-energy conversion efficiency. As expected, the tidal torques give no contribution to the growth of warping modes but tend to align the circumbinary disk with the orbital plane. Since the tidal torques can suppress the warping modes in the inner part of circumbinary disk, the circumbinary disk starts to be warped at radii larger than the marginally stable warping radius. If the warping radius is of the order ...

  7. Disk Accretion Onto High-Mass Planets

    CERN Document Server

    Lubow, S H; Artymowicz, P

    1999-01-01

    We analyze the nonlinear, two-dimensional response of a gaseous, viscous protoplanetary disk to the presence of a planet of one Jupiter mass (1 M_J) and greater that orbits a 1 solar mass star by using the ZEUS hydrodynamics code with high resolution near the planet's Roche lobe. The planet is assumed to be in a circular orbit about the central star and is not allowed to migrate. A gap is formed about the orbit of the planet, but there is a nonaxisymmetric flow through the gap and onto the planet. The gap partitions the disk into an inner (outer) disk that extends inside (outside) the planet's orbit. For a 1 M_J planet and typical disk parameters, the accretion through the gap onto the planet is highly efficient. For typical disk parameters, the mass doubling time scale is less than 10^5 years, considerably shorter than the disk lifetime. Following shocks near the L1 and L2 Lagrange points, disk material enters the Roche lobe in the form of two gas streams. Shocks occur within the Roche lobe as the gas stream...

  8. Numerical simulations of dissipationless disk accretion

    Science.gov (United States)

    Bogovalov, S. V.; Tronin, I. V.

    2017-09-01

    Our goal is to study the regime of disk accretion in which almost all of the angular momentum and energy is carried away by the wind outflowing from the disk in numerical experiments. For this type of accretion the kinetic energy flux in the outflowing wind can exceed considerably the bolometric luminosity of the accretion disk, what is observed in the plasma flow from galactic nuclei in a number of cases. In this paper we consider the nonrelativistic case of an outflow from a cold Keplerian disk. All of the conclusions derived previously for such a system in the self-similar approximation are shown to be correct. The numerical results agree well with the analytical predictions. The inclination angle of the magnetic field lines in the disk is less than 60°, which ensures a free wind outflow from the disk, while the energy flux per wind particle is greater than the particle rotation energy in its Keplerian orbit by several orders of magnitude, provided that the ratio r A/ r ≫ 1, where r A is the Alfvénic radius and r is the radius of the Keplerian orbit. In this case, the particle kinetic energy reaches half the maximum possible energy in the simulation region. The magnetic field collimates the outflowing wind near the rotation axis and decollimates appreciably the wind outflowing from the outer disk periphery.

  9. Dynamics of acoustically levitated disk samples.

    Science.gov (United States)

    Xie, W J; Wei, B

    2004-10-01

    The acoustic levitation force on disk samples and the dynamics of large water drops in a planar standing wave are studied by solving the acoustic scattering problem through incorporating the boundary element method. The dependence of levitation force amplitude on the equivalent radius R of disks deviates seriously from the R3 law predicted by King's theory, and a larger force can be obtained for thin disks. When the disk aspect ratio gamma is larger than a critical value gamma(*) ( approximately 1.9 ) and the disk radius a is smaller than the critical value a(*) (gamma) , the levitation force per unit volume of the sample will increase with the enlargement of the disk. The acoustic levitation force on thin-disk samples ( gammafield for stable levitation of a large water drop is to adjust the reflector-emitter interval H slightly above the resonant interval H(n) . The simulation shows that the drop is flattened and the central parts of its top and bottom surface become concave with the increase of sound pressure level, which agrees with the experimental observation. The main frequencies of the shape oscillation under different sound pressures are slightly larger than the Rayleigh frequency because of the large shape deformation. The simulated translational frequencies of the vertical vibration under normal gravity condition agree with the theoretical analysis.

  10. Lunar and Meteorite Sample Disk for Educators

    Science.gov (United States)

    Foxworth, Suzanne; Luckey, M.; McInturff, B.; Allen, J.; Kascak, A.

    2015-01-01

    NASA Johnson Space Center (JSC) has the unique responsibility to curate NASA's extraterrestrial samples from past and future missions. Curation includes documentation, preservation, preparation and distribution of samples for research, education and public outreach. Between 1969 and 1972 six Apollo missions brought back 382 kilograms of lunar rocks, core and regolith samples, from the lunar surface. JSC also curates meteorites collected from a US cooperative effort among NASA, the National Science Foundation (NSF) and the Smithsonian Institution that funds expeditions to Antarctica. The meteorites that are collected include rocks from Moon, Mars, and many asteroids including Vesta. The sample disks for educational use include these different samples. Active relevant learning has always been important to teachers and the Lunar and Meteorite Sample Disk Program provides this active style of learning for students and the general public. The Lunar and Meteorite Sample Disks permit students to conduct investigations comparable to actual scientists. The Lunar Sample Disk contains 6 samples; Basalt, Breccia, Highland Regolith, Anorthosite, Mare Regolith and Orange Soil. The Meteorite Sample Disk contains 6 samples; Chondrite L3, Chondrite H5, Carbonaceous Chondrite, Basaltic Achondrite, Iron and Stony-Iron. Teachers are given different activities that adhere to their standards with the disks. During a Sample Disk Certification Workshop, teachers participate in the activities as students gain insight into the history, formation and geologic processes of the moon, asteroids and meteorites.

  11. The Dark Disk of the Milky Way

    CERN Document Server

    Purcell, Chris W; Kaplinghat, Manoj

    2009-01-01

    Massive satellite accretions onto early galactic disks can lead to the deposition of dark matter in disk-like configurations that co-rotate with the galaxy. This phenomenon has potentially dramatic consequences for dark matter detection experiments. We utilize focused, high-resolution simulations of accretion events onto disks designed to be Galaxy analogues, and compare the resultant disks to the morphological and kinematic properties of the Milky Way's thick disk in order to bracket the range of co-rotating accreted dark matter. We find that the Milky Way's merger history must have been unusually quiescent compared to median LCDM expectations and therefore its dark disk must be relatively small: the fraction of accreted dark disk material near the Sun is about 20% of the host halo density or smaller and the co-rotating dark matter fraction near the Sun, defined as particles moving with a rotational velocity lag less than 50 km/s, is enhanced by about 30% or less compared to a standard halo model. Such a dar...

  12. The CDF Run II Disk Inventory Manager

    Institute of Scientific and Technical Information of China (English)

    PaulHubbard; StephanLammel

    2001-01-01

    The Collider Detector at Fermilab(CDF) experiment records and analyses proton-antiprotion interactions at a center-of -mass energy of 2 TeV,Run II of the Fermilab Tevatron started in April of this year,The duration of the run is expected to be over two years.One of the main data handling strategies of CDF for RUn II is to hide all tape access from the user and to facilitate sharing of data and thus disk space,A disk inventory manager was designed and developed over the past years to keep track of the data on disk.to coordinate user access to the data,and to stage data back from tape to disk as needed.The CDF Run II disk inventory manager consists of a server process,a user and administrator command line interfaces.and a library with the routines of the client API.Data are managed in filesets which are groups of one or more files.The system keeps track of user acess to the filesets and attempts to keep frequently accessed data on disk.Data that are not on disk are automatically staged back from tape as needed.For CDF the main staging method is based on the mt-tools package as tapes are written according to the ANSI standard.

  13. SPH simulations of structures in protoplanetary disks

    Science.gov (United States)

    Demidova, T. V.; Grinin, V. P.

    2017-02-01

    Using the GADGET-2 code modified by us, we have computed hydrodynamic models of a protoplanetary disk perturbed by a low-mass companion. We have considered the cases of circular and eccentric orbits coplanar with the disk and inclined relative to its midplane. During our simulations we computed the column density of test particles on the line of sight between the central star and observer. On this basis we computed the column density of circumstellar dust by assuming the dust and gas to be well mixed with a mass ratio of 1: 100. To study the influence of the disk orientation relative to the observer on the interstellar extinction, we performed our computations for four inclinations of the line of sight to the disk plane and eight azimuthal directions. The column densities in the circumstellar disk of the central star and the circumbinary disk were computed separately. Our computations have shown that periodic column density oscillations can arise in both inner and circumbinary disks. The amplitude and shape of these oscillations depend on the system's parameters (the orbital eccentricity and inclination, the component mass ratio) and its orientation in space. The results of our simulations can be used to explain the cyclic brightness variations of young UX Ori stars.

  14. Detecting circumstellar disks around gravitational microlenses

    CERN Document Server

    Hundertmark, M; Dreizler, S

    2009-01-01

    We investigate the chance of detecting proto-planetary or debris disks in stars that induce microlensing events (lenses). The modification of the light curves shapes due to occultation and extinction by the disks as well as the additional gravitational deflection caused by the additional mass is considered. The magnification of gravitational microlensing events is calculated using the ray shooting method. The occultation is taken into account by neglecting or weighting the images on the lens plane according to a transmission map of the corresponding disk for a point source point lens (PSPL) model. The estimated frequency of events is obtained by taking the possible inclinations and optical depths of the disk into account. We conclude that gravitational microlensing can be used, in principle, as a tool for detecting debris disks beyond 1 kpc, but estimate that each year of the order of 1 debris disk is expected for lens stars of F, G, or K spectral type and of the order of 10 debris disks might have shown sign...

  15. Cold Dark Matter Substructure and Galactic Disks

    CERN Document Server

    Kazantzidis, Stelios; Bullock, James S

    2008-01-01

    We perform a set of high-resolution, dissipationless N-body simulations to investigate the influence of cold dark matter (CDM) substructure on the dynamical evolution of thin galactic disks. Our method combines cosmological simulations of galaxy-sized CDM halos to derive the properties of substructure populations and controlled numerical experiments of consecutive subhalo impacts onto initially-thin, fully-formed disk galaxies. We demonstrate that close encounters between massive subhalos and galactic disks since z~1 should be common occurrences in LCDM models. In contrast, extremely few satellites in present-day CDM halos are likely to have a significant impact on the disk structure. One typical host halo merger history is used to seed controlled N-body experiments of subhalo-disk encounters. As a result of these accretion events, the disk thickens considerably at all radii with the disk scale height increasing in excess of a factor of 2 in the solar neighborhood. We show that interactions with the subhalo p...

  16. The Hot Inner Disk of FU Ori

    CERN Document Server

    Zhu, Zhaohuan; Calvet, Nuria; Hernandez, Jesus; Muzerolle, James; Tannirkulam, Ajay-Kumar

    2007-01-01

    We have constructed a detailed radiative transfer disk model which reproduces the main features of the spectrum of the outbursting young stellar object FU Orionis from ~ 4000 angstrom, to ~ 8 micron. Using an estimated visual extinction Av~1.5, a steady disk model with a central star mass ~0.3 Msun and a mass accretion rate ~ 2e-4 Msun/yr, we can reproduce the spectral energy distribution of FU Ori quite well. With the mid-infrared spectrum obtained by the Infrared Spectrograph (IRS) on board the Spitzer Space Telescope, we estimate that the outer radius of the hot, rapidly accreting inner disk is ~ 1 AU using disk models truncated at this outer radius. Inclusion of radiation from a cooler irradiated outer disk might reduce the outer limit of the hot inner disk to ~ 0.5 AU. In either case, the radius is inconsistent with a pure thermal instability model for the outburst. Our radiative transfer model implies that the central disk temperature Tc > 1000 K out to ~ 0.5 - 1 AU, suggesting that the magnetorotationa...

  17. The effects of viscosity on circumplanetary disks

    Institute of Scientific and Technical Information of China (English)

    De-Fu Bu; Hsien Shang; Feng Yuan

    2013-01-01

    The effects of viscosity on the circumplanetary disks residing in the vicinity of protoplanets are investigated through two-dimensional hydrodynamical simulations with the shearing sheet model.We find that viscosity can considerably affect properties of the circumplanetary disk when the mass of the protoplanet Mp (<) 33 M(⊙),where M(⊙) is the Earth's mass.However,effects of viscosity on the circumplanetary disk are negligibly small when the mass of the protoplanet Mp(>) 33 M(⊙).We find that when Mp(<) 33 M(⊙),viscosity can markedly disrupt the spiral structure of the gas around the planet and smoothly distribute the gas,which weakens the torques exerted on the protoplanet.Thus,viscosity can slow the migration speed of a protoplanet.After including viscosity,the size of the circumplanetary disk can be decreased by a factor of (>) 20%.Viscosity helps to transport gas into the circumplanetary disk from the differentially rotating circumstellar disk.The mass of the circumplanetary disk can be increased by a factor of 50% after viscosity is taken into account when Mp(<) 33 M(⊙).Effects of viscosity on the formation of planets and satellites are briefly discussed.

  18. Viscous Stability of Relativistic Keplerian Accretion Disks

    CERN Document Server

    Ghosh, P

    1998-01-01

    We investigate the viscous stability of thin, Keplerian accretion disks in regions where general relativistic (GR) effects are essential. For gas pressure dominated (GPD) disks, we show that the Newtonian conclusion that such disks are viscously stable is reversed by GR modifications in the behaviors of viscous stress and surface density over a significantly large annular region not far from the innermost stable orbit at $r=\\rms$. For slowly-rotating central objects, this region spans a range of radii $14\\lo r\\lo 19$ in units of the central object's mass $M$. For radiation pressure dominated (RPD) disks, the Newtonian conclusion that they are viscously unstable remains valid after including the above GR modifications, except in a very small annulus around $r\\approx 14M$, which has a negligible influence. Inclusion of the stabilizing effect of the mass-inflow through the disk's inner edge via a GR analogue of Roche-lobe overflow adds a small, stable region around \\rms~for RPD disks, but leaves GPD disks unchan...

  19. Gravitational Stirring in Planetary Debris Disks

    CERN Document Server

    Kenyon, S J; Kenyon, Scott J.; Bromley, Benjamin C.

    2001-01-01

    We describe gravitational stirring models of planetary debris disks using a new multi-annulus planetesimal evolution code. The current code includes gravitational stirring and dynamical friction; future studies will include coagulation, fragmentation, Poynting-Robertson drag, and other physical processes. We use the results of our calculations to investigate the physical conditions required for small bodies in a planetesimal disk to reach the shattering velocity and begin a collisional cascade. Our results demonstrate that disks composed primarily of bodies with a single size will not undergo a collisional cascade which produces small dust grains at 30-150 AU on timescales of 1 Gyr or smaller. Disks with a size distribution of bodies reach conditions necessary for a collisional cascade in 10 Myr to 1 Gyr if the disk is at least as massive as a minimum mass solar nebula and if the disk contains objects with radii of 500 km or larger. The estimated 500 Myr survival time for these disks is close to the median ag...

  20. Circumstellar disks around Herbig Be stars

    CERN Document Server

    Alonso-Albi, T; Bachiller, R; Neri, R; Planesas, P; Testi, L; Berne, O; Joblin, C

    2008-01-01

    We have carried out a search for circumstellar disks around Herbig Be stars using the NRAO Very Large Array (VLA) and the IRAM Plateau de Bure (PdB) interferometers. In this Paper, we present our new VLA and PdBI data on the three objects MWC 297, Z CMa and LKHa 215. We have constructed the SED from near-IR to centimeter wavelengths by adding our millimeter and centimeter data to the available data at other wavelengths, mainly Spitzer images. The whole SED has been fitted using a disk+envelope model. In addition, we have compiled all the disk millimeter observations in the literature and made some statistics. We show that the disk mass is usually only a small percentage (less than 10%) of the mass of the whole envelope in HBe stars. Concerning the disks, there are large source to source variations. Two disks of our sample, R Mon and Z CMa, have similar sizes and masses to those found in T Tauri and Herbig Ae stars. The disks around MWC 1080 and MWC 297 are, however, smaller (rout<100 AU). We have not detec...

  1. Accretion Disks around Young Low Mass Stars

    Directory of Open Access Journals (Sweden)

    Paola D´Alessio

    2001-01-01

    Full Text Available In the past decade, it has become clear that almost half of the low mass pre-main sequence stars are surrounded by disks, which are responsible for the observed infrared and optical-UV excess emission. The characterization of the structure of circumstellar disks is a crucial step towards understanding the early stellar evolution and planet formation. The thesis summarized here presents physical models of the detailed structure of accretion disks surrounding T Tauri stars. The disks are assumed to be in steady state, in vertical hydrostatic equilibrium, and with a turbulent viscosity described by the alpha-prescription. We consider different heating mechanisms: viscous dissipation, heating by cosmic rays and radioactive decay, irradiation by the central star or irradiation by an infalling envelope. The energy is transported in the vertical direction by radiation, convection and the turbulent flux. Give n the disk structure, we calculate its emission by integrating the radiative transfer equation for an arbitrary orientation of the disk relative to the line of sight. Spectral energy distributions (SEDs and images are compared with observations, and disk properties can be inferred or constrained.

  2. Acute periodontal lesions.

    Science.gov (United States)

    Herrera, David; Alonso, Bettina; de Arriba, Lorenzo; Santa Cruz, Isabel; Serrano, Cristina; Sanz, Mariano

    2014-06-01

    This review provides updates on acute conditions affecting the periodontal tissues, including abscesses in the periodontium, necrotizing periodontal diseases and other acute conditions that cause gingival lesions with acute presentation, such as infectious processes not associated with oral bacterial biofilms, mucocutaneous disorders and traumatic and allergic lesions. A periodontal abscess is clinically important because it is a relatively frequent dental emergency, it can compromise the periodontal prognosis of the affected tooth and bacteria within the abscess can spread and cause infections in other body sites. Different types of abscesses have been identified, mainly classified by their etiology, and there are clear differences between those affecting a pre-existing periodontal pocket and those affecting healthy sites. Therapy for this acute condition consists of drainage and tissue debridement, while an evaluation of the need for systemic antimicrobial therapy will be made for each case, based on local and systemic factors. The definitive treatment of the pre-existing condition should be accomplished after the acute phase is controlled. Necrotizing periodontal diseases present three typical clinical features: papilla necrosis, gingival bleeding and pain. Although the prevalence of these diseases is not high, their importance is clear because they represent the most severe conditions associated with the dental biofilm, with very rapid tissue destruction. In addition to bacteria, the etiology of necrotizing periodontal disease includes numerous factors that alter the host response and predispose to these diseases, namely HIV infection, malnutrition, stress or tobacco smoking. The treatment consists of superficial debridement, careful mechanical oral hygiene, rinsing with chlorhexidine and daily re-evaluation. Systemic antimicrobials may be used adjunctively in severe cases or in nonresponding conditions, being the first option metronidazole. Once the acute

  3. The $Spitzer$ infrared spectrograph survey of protoplanetary disks in Orion A: I. disk properties

    CERN Document Server

    Kim, K H; Manoj, P; Forrest, W J; Furlan, Elise; Najita, Joan; Sargent, Benjamin; Hernández, Jesús; Calvet, Nuria; Adame, Lucía; Espaillat, Catherine; Megeath, S T; Muzerolle, James; McClure, M K

    2016-01-01

    We present our investigation of 319 Class II objects in Orion A observed by $Spitzer$/IRS. We also present the follow-up observation of 120 of these Class II objects in Orion A from IRTF/SpeX. We measure continuum spectral indices, equivalent widths, and integrated fluxes that pertain to disk structure and dust composition from IRS spectra of Class II objects in Orion A. We estimate mass accretion rates using hydrogen recombination lines in the SpeX spectra of our targets. Utilizing these properties, we compare the distributions of the disk and dust properties of Orion A disks to those of Taurus disks with respect to position within Orion A (ONC and L1641) and to the sub-groups by the inferred radial structures, such as transitional disks vs. radially continuous full disks. Our main findings are as follows. (1) Inner disks evolve faster than the outer disks. (2) Mass accretion rate of transitional disks and that of radially continuous full disks are statistically significantly displaced from each other. The m...

  4. Atypical idiopathic inflammatory demyelinating lesions

    DEFF Research Database (Denmark)

    Wallner-Blazek, Mirja; Rovira, Alex; Fillipp, Massimo;

    2013-01-01

    Atypical lesions of a presumably idiopathic inflammatory demyelinating origin present quite variably and may pose diagnostic problems. The subsequent clinical course is also uncertain. We, therefore, wanted to clarify if atypical idiopathic inflammatory demyelinating lesions (AIIDLs) can be class...

  5. Lesions of cartilage in the femoropateliar joint, diagnosis by computerized tomography

    Energy Technology Data Exchange (ETDEWEB)

    Reiser, M.; Anacker, H.; Karpf, P.M.; Hoerterer, H.; Paar, O.; Riel, K.A.

    1982-01-21

    The conventional arthrographic methods for demonstration of the femoro-patellar joint are not sufficiently reliable. Through the use of CT-arthrography a cross-sectional image free of superimposition and possessing a high density resolution is available thus facilitating a direct demonstration of the joint cartilage. Traumatic and degenerative lesions of the cartilage can be clearly shown by CT-arthrography. Damage of cartilage in patients with chondromalacia patellae can be differentiated in its different stages. The shape of the patella and its relation to femoral condyles can be evaluated more accurate than by conventional axial X-rays.

  6. Yb Thin-Disk Laser Results

    Energy Technology Data Exchange (ETDEWEB)

    Zapata, L E; Beach, R A; Mitchell, S; Payne, S A

    2002-05-14

    Thin-disk laser configurations have recently been demonstrated at cw output povters exceeding 1 kW [1]. Thin-disk lasers enable the generation of high average power by minimizing the distance over which waste heat is transported. A disk-laser of transverse dimensions significantly larger than its thickness will sustain laser output with intensity proportional to the thermal flux it dissipates. The fracture strength of the laser material limits the maximum temperature difference of a credible design. Further increases in the heat dissipation capacity of a disk varies inversely with the disk thickness (t) thus, the average laser output intensity of a thin/disk laser scales as 1/t; that is, to maximize the output intensity we must use the thinnest possible disk that is consistent with the pump geometry. The main challenge for the laser designer is then to coerce a thin gain sample into absorbing pump power efficiently. For this purpose, use of a highly absorbing gain medium is desirable in combination with a pumping geometry that allows multi-passing of the pump light. An important feature of the thin-disk laser is that one-dimensional thermal gradients away from the edges are made to align with the extraction beam Thus, as long as pumping and cooling fields are uniformly distributed, the contributions to wavefront error from dn/dT and the stress optic effect integrate along a 1-dimensional thermal gradient and a constant optical path-length-difference across the extent of the beam. The thin-disk laser therefore, holds promise for high beam quality at high average power.

  7. MAGNETIC FIELDS IN EARLY PROTOSTELLAR DISK FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    González-Casanova, Diego F.; Lazarian, Alexander [Astronomy Department, University of Wisconsin-Madison, 475 North Charter Street, Madison, WI 53706-1582 (United States); Santos-Lima, Reinaldo, E-mail: casanova@astro.wisc.edu [Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, R. do Matão, 1226, São Paulo, SP 05508-090 (Brazil)

    2016-03-10

    We consider formation of accretion disks from a realistically turbulent molecular gas using 3D MHD simulations. In particular, we analyze the effect of the fast turbulent reconnection described by the Lazarian and Vishniac model for the removal of magnetic flux from a disk. With our numerical simulations we demonstrate how the fast reconnection enables protostellar disk formation resolving the so-called “magnetic braking catastrophe.” In particular, we provide a detailed study of the dynamics of a 0.5 M{sub ⊙} protostar and the formation of its disk for up to several thousands years. We measure the evolution of the mass, angular momentum, magnetic field, and turbulence around the star. We consider effects of two processes that strongly affect the magnetic transfer of angular momentum, both of which are based on turbulent reconnection: the first, “reconnection diffusion,” removes the magnetic flux from the disk; the other involves the change of the magnetic field's topology, but does not change the absolute value of the magnetic flux through the disk. We demonstrate that for the first mechanism, turbulence causes a magnetic flux transport outward from the inner disk to the ambient medium, thus decreasing the coupling of the disk to the ambient material. A similar effect is achieved through the change of the magnetic field's topology from a split monopole configuration to a dipole configuration. We explore how both mechanisms prevent the catastrophic loss of disk angular momentum and compare both above turbulent reconnection mechanisms with alternative mechanisms from the literature.

  8. Mass Extinctions and a Dark Disk

    CERN Document Server

    Kramer, Eric David

    2016-01-01

    We consider whether the observed periodicity of mass extinctions and of comet impacts on Earth is consistent with Solar oscillation about the Galactic midplane and spiral arm crossings. It is of further interest to determine whether a hypothetical thin dark disk is necessary to give the right periodicity, and whether such a dark disk is allowed given kinematic and other observational constaints on the Galaxy's gravitational potential. We show that a dark disk consistent with recent bounds, combined with data for spiral arm crossing, can lead to the required periodicity. Moreover, we find that the best fit values correctly predict the date of the Chicxulub crater dated to 66 My ago.

  9. The innermost astronomical unit of protoplanetary disks

    CERN Document Server

    Kluska, J; Benisty, M

    2016-01-01

    Circumstellar disks around young stars are the birthsites of planets. It is thus fundamental to study the disks in which they form, their structure and the physical conditions therein. The first astronomical unit is of great interest because this is where the terrestrial-planets form and the angular momentum is controled via massloss through winds/jets. With its milli-arcsecond resolution, optical interferometry is the only technic able to spatially resolve the first few astronomical units of the disk. In this review, we will present a broad overview of studies of young stellar objects with interferometry, and discuss prospects for the future.

  10. Scattered light mapping of protoplanetary disks

    Science.gov (United States)

    Stolker, T.; Dominik, C.; Min, M.; Garufi, A.; Mulders, G. D.; Avenhaus, H.

    2016-12-01

    Context. High-contrast scattered light observations have revealed the surface morphology of several dozen protoplanetary disks at optical and near-infrared wavelengths. Inclined disks offer the opportunity to measure part of the phase function of the dust grains that reside in the disk surface which is essential for our understanding of protoplanetary dust properties and the early stages of planet formation. Aims: We aim to construct a method which takes into account how the flaring shape of the scattering surface of an optically thick protoplanetary disk projects onto the image plane of the observer. This allows us to map physical quantities (e.g., scattering radius and scattering angle) onto scattered light images and retrieve stellar irradiation corrected images (r2-scaled) and dust phase functions. Methods: The scattered light mapping method projects a power law shaped disk surface onto the detector plane after which the observed scattered light image is interpolated backward onto the disk surface. We apply the method on archival polarized intensity images of the protoplanetary disk around HD 100546 that were obtained with VLT/SPHERE in the R' band and VLT/NACO in the H and Ks bands. Results: The brightest side of the r2-scaled R' band polarized intensity image of HD 100546 changes from the far to the near side of the disk when a flaring instead of a geometrically flat disk surface is used for the r2-scaling. The decrease in polarized surface brightness in the scattering angle range of 40°-70° is likely a result of the dust phase function and degree of polarization which peak in different scattering angle regimes. The derived phase functions show part of a forward scattering peak, which indicates that large, aggregate dust grains dominate the scattering opacity in the disk surface. Conclusions: Projection effects of a protoplanetary disk surface need to be taken into account to correctly interpret scattered light images. Applying the correct scaling for the

  11. Patterns In Debris Disks: No Planets Required?

    Science.gov (United States)

    Kuchner, Marc

    2012-01-01

    Debris disks like those around Fomalhaut and Beta Pictoris show striking dust patterns often attributed to hidden exoplanets. These patterns have been crucial for constraining the masses and orbits of these planets. But adding a bit of gas to our models of debris disks--too little gas to detect--seems to alter this interpretation. Small amounts of gas lead to new dynamical instabilities that may mimic the narrow eccentric rings and other structures planets would create in a gas-free disk. Can we still use dust patterns to find hidden exoplanets?

  12. Millimeter Continuum Observations Of Disk Solids

    Science.gov (United States)

    Andrews, Sean

    2016-07-01

    I will offer a condensed overview of some key issues in protoplanetary disk research that makes use interferometric measurements of the millimeter-wavelength continuum emitted by their solid particles. Several lines of evidence now qualitatively support theoretical models for the growth and migration of disk solids, but also advertise a quantitative tension with the traditional efficiency of that evolution. New observations of small-scale substructures in disks might both reconcile the conflict and shift our focus in the mechanics of planet formation.

  13. A disappearing neonatal skin lesion.

    LENUS (Irish Health Repository)

    Hawkes, Colin Patrick

    2012-01-31

    A preterm baby girl was noted at birth to have a firm, raised, non-tender skin lesion located over her right hip. She developed three similar smaller lesions on her ear, buttock and right knee. All lesions had resolved by 2 months of age.

  14. Disk-Loss and Disk-Renewal Phases in Classical Be Stars II. Contrasting with Stable and Variable Disks

    CERN Document Server

    Draper, Zachary H; Bjorkman, Karen S; Meade, Marilyn R; Haubois, Xavier; Mota, Bruno C; Carciofi, Alex C; Bjorkman, Jon E

    2014-01-01

    Recent observational and theoretical studies of classical Be stars have established the utility of polarization color diagrams (PCD) in helping to constrain the time-dependent mass decretion rates of these systems. We expand on our pilot observational study of this phenomenon, and report the detailed analysis of a long-term (1989-2004) spectropolarimetric survey of 9 additional classical Be stars, including systems exhibiting evidence of partial disk-loss/disk-growth episodes as well as systems exhibiting long-term stable disks. After carefully characterizing and removing the interstellar polarization along the line of sight to each of these targets, we analyze their intrinsic polarization behavior. We find that many steady-state Be disks pause at the top of the PCD, as predicted by theory. We also observe sharp declines in the Balmer jump polarization for later spectral type, near edge-on steady-state disks, again as recently predicted by theory, likely caused when the base density of the disk is very high, ...

  15. Effects of inclined star-disk encounter on protoplanetary disk size

    CERN Document Server

    Bhandare, Asmita; Pfalzner, Susanne

    2016-01-01

    Most, if not all, young stars are initially surrounded by protoplanetary disks. Owing to the preferential formation of stars in stellar clusters, the protoplanetary disks around these stars may potentially be affected by the cluster environment. Various works have investigated the influence of stellar fly-bys on disks, although many of them consider only the effects due to parabolic, coplanar encounters often for equal-mass stars, which is only a very special case. We perform numerical simulations to study the fate of protoplanetary disks after the impact of parabolic star-disk encounter for the less investigated case of inclined up to coplanar, retrograde encounters, which is a much more common case. Here, we concentrate on the disk size after such encounters because this limits the size of the potentially forming planetary systems. In addition, with the possibilities that ALMA offers, now a direct comparison to observations is possible. Covering a wide range of periastron distances and mass ratios between t...

  16. Disk-cylinder and disk-sphere nanoparticles via a block copolymer blend solution construction.

    Science.gov (United States)

    Zhu, Jiahua; Zhang, Shiyi; Zhang, Ke; Wang, Xiaojun; Mays, Jimmy W; Wooley, Karen L; Pochan, Darrin J

    2013-01-01

    Researchers strive to produce nanoparticles with complexity in composition and structure. Although traditional spherical, cylindrical and membranous, or planar, nanostructures are ubiquitous, scientists seek more complicated geometries for potential functionality. Here we report the simple solution construction of multigeometry nanoparticles, disk-sphere and disk-cylinder, through a straightforward, molecular-level, blending strategy with binary mixtures of block copolymers. The multigeometry nanoparticles contain disk geometry in the core with either spherical patches along the disk periphery in the case of disk-sphere particles or cylindrical edges and handles in the case of the disk-cylinder particles. The portions of different geometry in the same nanoparticles contain different core block chemistry, thus also defining multicompartments in the nanoparticles. Although the block copolymers chosen for the blends are important for the definition of the final hybrid particles, the control of the kinetic pathway of assembly is critical for successful multigeometry particle construction.

  17. Disk Winds Driven by Magnetorotational Instability and Dispersal of Proto-Planetary Disks

    CERN Document Server

    Suzuki, T K

    2008-01-01

    By performing local three-dimensional MHD simulations of stratified accretion disks, we investigate disk winds driven by MHD turbulence. Initially given weak vertical magnetic fields are effectively amplified by magnetorotational instability and winding due to differential rotation. Large scale channel flows develop most effectively at 1.5 - 2 times the scale heights where the magnetic pressure is comparable to but slightly smaller than the gas pressure. The breakup of these channel flows drives structured disk winds by transporting the Poynting flux to the gas. These features are universally observed in the simulations of various initial fields. This disk wind process should play an essential role in the dynamical evaporation of proto-planetary disks. The breakup of channel flows also excites the momentum fluxes associated with Alfvenic and (magneto-)sonic waves toward the mid-plane, which possibly contribute to the sedimentation of small dust grains in protoplanetary disks.

  18. Lesiones deportivas Sports injuries

    Directory of Open Access Journals (Sweden)

    Isabel Cristina Gallego Ching

    2007-04-01

    Full Text Available El estrés generado por la práctica deportiva ha originado una mayor probabilidad de que los atletas presenten lesiones agudas y crónicas. En el ámbito mundial existen diferentes investigaciones acerca de la incidencia de lesiones deportivas. La comparación de sus resultados es difícil por las diferencias en las características de la población y en la forma de reportar los datos, que varía ampliamente entre los estudios (proporciones o tasas de incidencia o tasas por cada 100 ó 1.000 participantes o tasas por horas de juego o por número de partidos jugados. Las tasas varían entre 1,7 y 53 lesiones por 1.000 horas de práctica deportiva, entre 0,8 y 90,9 por 1.000 horas de entrenamiento, entre 3,1 y 54,8 por 1.000 horas de competición y de 6,1 a 10,9 por 100 juegos. La gran variación entre las tasas de incidencia se explica por las diferencias existentes entre los deportes, los países, el nivel competitivo, las edades y la metodología empleada en los estudios. Se ha definido la lesión deportiva como la que ocurre cuando los atletas están expuestos a la práctica del deporte y se produce alteración o daño de un tejido, afectando el funcionamiento de la estructura. Los deportes de contacto generan mayor riesgo de presentar lesiones; se destacan al respecto los siguientes: fútbol, rugby, baloncesto, balonmano, artes marciales y jockey. Las lesiones ocurren con mayor probabilidad en las competencias que en el entrenamiento. Stress generated by sports practice has increased the probability that athletes suffer from acute and chronic injuries. Worldwide, there have been many different investigations concerning the incidence of sport injuries. The different ways in which results have been presented makes it difficult to compare among them. Rates of sports injuries vary between 1.7 and 53 per 1.000 hours of sports practice; 0.8 and 90.9 per 1.000 hours of training; 3.1 and 54.8 per 1.000 hours of competition, and 6.1 and 10.9 per 100

  19. Imaging of degenerative spine disease--the state of the art.

    Science.gov (United States)

    Sasiadek, Marek J; Bladowska, Joanna

    2012-01-01

    The authors review the current state of imaging of degenerative spinal disease (DSD), which is one of the most common disorders in humans. The most important definitions as well as short descriptions of the etiopathology and clinical presentation of DSD are provided first, followed by an overview of conventional and advanced imaging methods that are used in DSD. The authors then discuss in detail the imaging patterns of particular types of degenerative changes. Finally, the current imaging algorithm in DSD is presented. The imaging method of choice is magnetic resonance, including advanced techniques--especially diffusion tensor imaging. Other imaging methods (plain radiography, computed tomography, vascular studies, scintigraphy, positron emission tomography, discography) play a supplementary role ).

  20. Polyetheretherketone (PEEK) rods: short-term results in lumbar spine degenerative disease.

    Science.gov (United States)

    Colangeli, S; Barbanti Brodàno, G; Gasbarrini, A; Bandiera, S; Mesfin, A; Griffoni, C; Boriani, S

    2015-06-01

    Pedicle screw and rod instrumentation has become the preferred technique for performing stabilization and fusion in the surgical treatment of lumbar spine degenerative disease. Rigid fixation leads to high fusion rates but may also contribute to stress shielding and adjacent segment degeneration. Thus, the use of semirigid rods made of polyetheretherketone (PEEK) has been proposed. Although the PEEK rods biomechanical properties, such as anterior load sharing properties, have been shown, there are few clinical studies evaluating their application in the lumbar spine surgical treatment. This study examined a retrospective cohort of patients who underwent posterior lumbar fusion for degenerative disease using PEEK rods, in order to evaluate the clinical and radiological outcomes and the incidence of complications.

  1. Stand-alone anterior lumbar interbody fusion for treatment of degenerative spondylolisthesis.

    Science.gov (United States)

    Rao, Prashanth J; Ghent, Finn; Phan, Kevin; Lee, Keegan; Reddy, Rajesh; Mobbs, Ralph J

    2015-10-01

    We sought to evaluate the clinical and radiologic efficacy of stand-alone anterior lumbar interbody fusion (ALIF) for low grade degenerative spondylolisthesis, the favoured surgical management approach at our institution. The optimal approach for surgical management of spondylolisthesis remains contentious. We performed a prospective analysis of all consecutive patients with low grade lumbar spondylolisthesis who underwent ALIF between 2009 and 2013 by a single surgeon (n=27). The mean age was 64.9 years with a male to female ratio of 14:13. There were 32 levels operated and the average preoperative spondylolisthesis was 14.8%, which reduced to 6.4% postoperatively and 9.4% at the latest follow-up (p=0001). Postoperative disc height was increased to 175% of preoperative values and was statistically significant (plumbar degenerative spondylolisthesis. Future studies should include adequately powered, prospective, multicentre registry studies with long term follow-up to allow a better assessment of the relative benefits and risks.

  2. Regeneration of the retina: toward stem cell therapy for degenerative retinal diseases.

    Science.gov (United States)

    Jeon, Sohee; Oh, Il-Hoan

    2015-04-01

    Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases.

  3. Acute pyogenic discitis in a degenerative intervertebral disc in an adult

    Directory of Open Access Journals (Sweden)

    Masamitsu Tanaka

    2010-08-01

    Full Text Available Masamitsu Tanaka1,2, Hiroshi Shimizu2, Yoshiyuki Yato1, Takashi Asazuma1, Koichi Nemoto11Department of Orthopedic Surgery, National Defense Medical College, Tokorozawa, Saitama; 2Department of Orthopedic Surgery, Self Defense Force Fukuoka Hospital, Kasuga, Fukuoka, JapanAbstract: A 35-year-old male who had been receiving conservative treatment for L4 isthmic spondylolisthesis suffered from pyogenic spondylodiscitis in the degenerative L4/L5 intervertebral disc space, which could be identified by comparison with previous images. Symptoms improved with conservative antibiotic treatment. Neovascularization may occur in the annulus fibrosus of a degenerative intervertebral disc, which may increase the risk of hematogenous infection, leading to “discitis” even in adults.Keywords: spondylodiscitis, spondylitis, discitis, isthmic spondylolisthesis, spondylolysis, intervertebral disc degeneration

  4. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients

    DEFF Research Database (Denmark)

    Kise, Nina Jullum; Risberg, May Arna; Stensrud, Silje;

    2016-01-01

    clinics in Norway. PARTICIPANTS: 140 adults, mean age 49.5 years (range 35.7-59.9), with degenerative medial meniscal tear verified by magnetic resonance imaging. 96% had no definitive radiographic evidence of osteoarthritis. INTERVENTIONS: 12 week supervised exercise therapy alone or arthroscopic partial......OBJECTIVE: To determine if exercise therapy is superior to arthroscopic partial meniscectomy for knee function in middle aged patients with degenerative meniscal tears. DESIGN: Randomised controlled superiority trial. SETTING: Orthopaedic departments at two public hospitals and two physiotherapy...... months, muscle strength had improved in the exercise group (P≤0.004). No serious adverse events occurred in either group during the two year follow-up. 19% of the participants allocated to exercise therapy crossed over to surgery during the two year follow-up, with no additional benefit. CONCLUSION...

  5. Revisiting the application of integrated physiotherapy in degenerative-dystrophic diseases of the musculoskeletal system

    Directory of Open Access Journals (Sweden)

    Kotenko K.V.

    2014-12-01

    Full Text Available Aim. The authors described a comprehensive program of frozen shoulder treatment, including extracorporeal shock wave therapy and pelotherapy. Objective: To evaluate the effectiveness of the inclusion of extracorporeal shock wave therapy and pelotherapy in rehabilitation of patients with degenerative diseases of the musculoskeletal system. Materials and Methods: there had been examined 120 patients during the study. Results: The result of the application of complex physiotherapy normalized indicators of metabolic and electrolyte imbalances that are important in the formation of a therapeutic effect. Conclusion: The application of extracorporeal shock wave therapy and in combination with pelotherapy in patients with scapula-humeral periarthritis is the elimination of metabolic and electrolyte imbalance, which is important in degenerative diseases of the musculoskeletal system

  6. Degenerative disc disease in the lumbar spine: Another cause for focally reduced activity on marrow scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, M. (Addenbrookes Hospital, Cambridge (United Kingdom). Dept. of Radiology); Miles, K.A. (Addenbrookes Hospital, Cambridge (United Kingdom). Dept. of Radiology Addenbrookes Hospital, Cambridge (United Kingdom). Dept. of Nuclear Medicine); Wraight, E.P. (Addenbrookes Hospital, Cambridge (United Kingdom). Dept. of Nuclear Medicine); Dixon, A.K. (Addenbrookes Hospital, Cambridge (United Kingdom). Dept. of Radiology Cambridge Univ. (United Kingdom))

    1992-05-01

    A patient is presented in whom a focal reduction in marrow activity in the lumbar spine on both leucocyte and nanocolloid marrow scintigraphy was subsequently shown to be due to fatty infiltration of marrow in association with disc degeneration. Degenerative disease in the lumbar spine has not been previously described as a cause of abnormal bone marrow distribution by such means and needs to be distinguished from a more serious pathology, such as malignant infiltration and vertebral infection, which it may mimic. In a retrospective review of 33 nanocolloid bone marrow and 117 leucocyte scintigrams, 8 showed a degree of reduced marrow activity in the lumbar spine consistent with that caused by degenerative changes. (orig.).

  7. A 12-Week Exercise Therapy Program in Middle-Aged Patients With Degenerative Meniscus Tears

    DEFF Research Database (Denmark)

    Stensrud, Silje; Roos, Ewa M.; Risberg, May Arna

    2012-01-01

    , progression, tolerance, and potential benefit from an exercise therapy program in these patients who have not had surgery. This study describes a progressive exercise therapy program aiming at improving neuromuscular function and muscle strength in middle-aged patients with degenerative meniscus tears......Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 STUDY DESIGN: Case Series. BACKGROUND: Exercise is a viable treatment alternative to arthroscopic partial meniscectomy in patients with degenerative meniscus tears. No study has reported in detail type of exercises...... global rating of change scale, isokinetic knee muscle strength tests, and 3 lower extremity performance tests. Post intervention there were clinically meaningful changes (greater than 10 points) in 16 of 20 patients on the KOOS knee related quality of life, 19 of 20 patients rated themselves as "a lot...

  8. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients

    DEFF Research Database (Denmark)

    Kise, Nina Jullum; Risberg, May Arna; Stensrud, Silje

    2016-01-01

    months, muscle strength had improved in the exercise group (P≤0.004). No serious adverse events occurred in either group during the two year follow-up. 19% of the participants allocated to exercise therapy crossed over to surgery during the two year follow-up, with no additional benefit. CONCLUSION......OBJECTIVE: To determine if exercise therapy is superior to arthroscopic partial meniscectomy for knee function in middle aged patients with degenerative meniscal tears. DESIGN: Randomised controlled superiority trial. SETTING: Orthopaedic departments at two public hospitals and two physiotherapy...... clinics in Norway. PARTICIPANTS: 140 adults, mean age 49.5 years (range 35.7-59.9), with degenerative medial meniscal tear verified by magnetic resonance imaging. 96% had no definitive radiographic evidence of osteoarthritis. INTERVENTIONS: 12 week supervised exercise therapy alone or arthroscopic partial...

  9. Neuroimaging and genetic risk for Alzheimer's disease and addiction-related degenerative brain disorders.

    Science.gov (United States)

    Roussotte, Florence F; Daianu, Madelaine; Jahanshad, Neda; Leonardo, Cassandra D; Thompson, Paul M

    2014-06-01

    Neuroimaging offers a powerful means to assess the trajectory of brain degeneration in a variety of disorders, including Alzheimer's disease (AD). Here we describe how multi-modal imaging can be used to study the changing brain during the different stages of AD. We integrate findings from a range of studies using magnetic resonance imaging (MRI), positron emission tomography (PET), functional MRI (fMRI) and diffusion weighted imaging (DWI). Neuroimaging reveals how risk genes for degenerative disorders affect the brain, including several recently discovered genetic variants that may disrupt brain connectivity. We review some recent neuroimaging studies of genetic polymorphisms associated with increased risk for late-onset Alzheimer's disease (LOAD). Some genetic variants that increase risk for drug addiction may overlap with those associated with degenerative brain disorders. These common associations offer new insight into mechanisms underlying neurodegeneration and addictive behaviors, and may offer new leads for treating them before severe and irreversible neurological symptoms appear.

  10. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients

    DEFF Research Database (Denmark)

    Kise, Nina Jullum; Risberg, May Arna; Stensrud, Silje

    2016-01-01

    clinics in Norway. PARTICIPANTS: 140 adults, mean age 49.5 years (range 35.7-59.9), with degenerative medial meniscal tear verified by magnetic resonance imaging. 96% had no definitive radiographic evidence of osteoarthritis. INTERVENTIONS: 12 week supervised exercise therapy alone or arthroscopic partial...... meniscectomy alone. MAIN OUTCOME MEASURES: Intention to treat analysis of between group difference in change in knee injury and osteoarthritis outcome score (KOOS4), defined a priori as the mean score for four of five KOOS subscale scores (pain, other symptoms, function in sport and recreation, and knee....... Our results should encourage clinicians and middle aged patients with degenerative meniscal tear and no definitive radiographic evidence of osteoarthritis to consider supervised exercise therapy as a treatment option.Trial registration www.clinicaltrials.gov (NCT01002794)....

  11. Exercise therapy versus arthroscopic partial meniscectomy for degenerative meniscal tear in middle aged patients

    DEFF Research Database (Denmark)

    Kise, Nina Jullum; Risberg, May Arna; Stensrud, Silje

    2016-01-01

    clinics in Norway. Participants 140 adults, mean age 49.5 years (range 35.7-59.9), with degenerative medial meniscal tear verified by magnetic resonance imaging. 96% had no definitive radiographic evidence of osteoarthritis. Interventions 12 week supervised exercise therapy alone or arthroscopic partial...... meniscectomy alone. Main outcome measures Intention to treat analysis of between group difference in change in knee injury and osteoarthritis outcome score (KOOS 4), defined a priori as the mean score for four of five KOOS subscale scores (pain, other symptoms, function in sport and recreation, and knee....... Our results should encourage clinicians and middle aged patients with degenerative meniscal tear and no definitive radiographic evidence of osteoarthritis to consider supervised exercise therapy as a treatment option. Trial registration www.clinicaltrials.gov (NCT01002794)....

  12. Degenerative primer design and gene sequencing validation for select turkey genes.

    Science.gov (United States)

    Hutsko, Stephanie L; Lilburn, Michael S; Wick, Macdonald

    2016-06-01

    We successfully designed and validated degenerative primers for turkey genes MUC2, RPS13, TBP and TFF2 based on chicken sequences in order to use gene transcription analysis to evaluate (quantify) the mucin transcription to probiotic supplementation in turkeys. Primers were designed for the genes MUC2, TFF2, RPS13 and TBP using a degenerative primer design method based on the available Gallus gallus sequences. All primer sets, which produced a single PCR amplicon of the expected sizes, were cloned into the TOPO(®) vector and then transformed into TOP 10(®) competent cells. Plasmid DNA isolation was performed on the TOP10(®) cell culture and sent for sequencing. Sequences were analyzed using NCBI BLAST. All genes sequenced had over 90% homology with both the chicken and predicted turkey sequences. The sequences were used to design new 100% homologous primer sets for the genes of interest. © 2016 Poultry Science Association Inc.

  13. Modern approaches to diagnostics of combined degenerative hip and spine pathology

    Directory of Open Access Journals (Sweden)

    V. V. Khominets

    2014-01-01

    Full Text Available The results of standard radiographs of 90 patients with hip-spine syndrome associated with one unilateral or bilateral III stage hip osteoarthhrosis were analyzed with the aim to improve the diagnostics of pathological changes in the "hip joint-pelvis- spine" complex. 12 parameters of sagittal spinal-pelvic balance and 3 parameters of frontal one were studied and the degenerative changes in spinal motional segments were evaluated. The statistical processing of obtained data was made. It was stated that the most frequent variant of sagittal spinal-pelvic profile is hyperlordosic one, followed by formation of degenerative changes especially in dorsal regions of spine (р=0,076.The strategy of patient examination with hip-spine syndrome was established from clinical and radiographic positions.

  14. Comparison of degree of postoperative muscle damage between MIS-TLIF- and PLIF treatment for single-level degenerative lumbar disease

    Directory of Open Access Journals (Sweden)

    Liang ZHOU

    2014-01-01

    Full Text Available Objective To compare the postoperative muscle damage after either posterior lumbar interbody fusion (PLIF or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF with the aid of X-Tube system in patients with singlelevel degenerative lumbar spinal disease. Methods The clinical data of 52 patients (males 28, females 24, aged 54.3±7.8 years with single-level degenerative lumbar spinal disease undergoing MIS-TLIF assisted by the X-Tube system from Oct 2010 to Sep 2011 was analyzed retrospectively. The operative time, intraoperative blood loss, postoperative drainage volume, postoperative bedtime, and serum creatine kinase (CK level 1 day before surgery and 1, 3 and 5 days after surgery were recorded and compared with those of 38 patients (males 20, females 18, aged 51.6±8.6 years with the same disease undergoing conventional open PLIF during the corresponding period. The back pain visual analogue score (VAS, Oswestry disability index (ODI score and imaging examination were performed before operation, after operation and during follow-up duration for each patient. Results There was no significant difference in the gender, age, clinical diagnosis, lesion location, preoperative CK level, VAS and ODI scores between the two groups (P>0.05. The operative time was longer in MIS-TLIF group than in PLIF group (P0.05. Radiological followup observation revealed good fusion 6 months after operation in all the patients. Conclusion The X-Tube-assisted MIS-TLIF has several advantages over conventional open PLIF, such as less intraoperative blood loss, milder muscle damage, and lighter back pain. DOI: 10.11855/j.issn.0577-7402.2013.12.04

  15. Klatskin-Like Lesions

    Directory of Open Access Journals (Sweden)

    M. P. Senthil Kumar

    2012-01-01

    Full Text Available Hilar cholangiocarcinoma, also known as Klatskin tumour, is the commonest type of cholangiocarcinoma. It poses unique problems in the diagnosis and management because of its anatomical location. Curative surgery in the form of major hepatic resection entails significant morbidity. About 5–15% of specimens resected for presumed Klatskin tumour prove not to be cholangiocarcinomas. There are a number of inflammatory, infective, vascular, and other pathologies, which have overlapping clinical and radiological features with a Klatskin tumour, leading to misinterpretation. This paper aims to summarise the features of such Klatskin-like lesions that have been reported in surgical literature.

  16. Klatskin-like lesions.

    Science.gov (United States)

    Senthil Kumar, M P; Marudanayagam, R

    2012-01-01

    Hilar cholangiocarcinoma, also known as Klatskin tumour, is the commonest type of cholangiocarcinoma. It poses unique problems in the diagnosis and management because of its anatomical location. Curative surgery in the form of major hepatic resection entails significant morbidity. About 5-15% of specimens resected for presumed Klatskin tumour prove not to be cholangiocarcinomas. There are a number of inflammatory, infective, vascular, and other pathologies, which have overlapping clinical and radiological features with a Klatskin tumour, leading to misinterpretation. This paper aims to summarise the features of such Klatskin-like lesions that have been reported in surgical literature.

  17. Lesiones en el deporte

    OpenAIRE

    2000-01-01

    Not available

    El incremento de la actividad física y del deporte, en las sociedades llamadas desarrolladas, ha traído consigo beneficios claros para la salud, reflejados en diferentes indicadores de salud. Simultáneamente, el deporte de competición obliga a una dedicación diaria a intensidad de entrenamiento, con objeto de obtener los elevados requerimientos físicos que exige la competición. Todo ello ha traído consigo la aparición de numerosas lesiones, fundamentalmen...

  18. Atrichia with Papular Lesions

    OpenAIRE

    Bansal, Manish; Manchanda, Kajal; Lamba, Sachin; Pandey, SS

    2011-01-01

    Atrichia with papular lesions (APL) is a rare autosomal recessive form of irreversible alopecia with onset at few months of age with papular keratin cysts over the body. It is associated with mutation in the Zinc finger domain of the human hairless gene on chromosome region 8p12. An eleven-year-old male presented with extensive alopecia starting at six months of age refractory to the treatment along with keratotic papules on the face and trunk. Biopsy from a papule showed mid-dermal keratin c...

  19. Lesiones en corredores amateurs

    OpenAIRE

    Natale, Vanesa

    2011-01-01

    Se realizó un estudio tomando como muestra a 100 corredores amateurs de la ciudad de Mar del Plata, en la cual el objetivo general fue determinar cuáles son las patologías más frecuentes en corredores. Correr no es solo un deporte en si mismo sino que tiene elementos de otras actividades deportivas, es decir, que las lesiones de los corredores también son comunes en otros tipos de deportes. El número de deportistas aumenta diariamente y al mismo tiempo aumentan el número de per...

  20. Cystic Lesions of the Mediastinum.

    Science.gov (United States)

    Vargas, Daniel; Suby-Long, Thomas; Restrepo, Carlos S

    2016-06-01

    Cystic lesions are commonly seen in the mediastinum, and they may arise from virtually any organ. The vast majority of these lesions are benign and result in no symptoms. When large, cysts may produce symptoms related to compression of adjacent structures. The most common mediastinal cysts are pericardial and foregut duplication cysts. Both computed tomography and magnetic resonance are routinely used to evaluate these lesions. Although computed tomography offers superior spatial resolution, magnetic resonance is useful in differentiating cysts that contain proteinaceous material from solid lesions. Occasionally, cysts arise from solid lesions, such as thymoma or teratoma. Although cysts are alike in appearance, location helps narrowing the differential diagnoses.

  1. A Prospective Study on the Outcome of Degenerative Lumbar Spinal Stenosis Treated With Open Laminotomy

    Directory of Open Access Journals (Sweden)

    Martin Wong Chung-Ting

    2012-12-01

    Result: There were significant improvement of mean Japanese Orthopaedic Association lumbar score, Oswestry Disability Index(ODI, and visual analogue scale (VAS. Male had significantly better result in ODI and VAS. There was no significant difference regarding to older age (>65 or the presence of preexisting degenerative spondylolisthesis. One patient was found to have increased lumbar instability after operation. The overall reoperation rate was 6.9%.

  2. Is there a role for wine in cancer and the degenerative diseases of aging?

    OpenAIRE

    Creina S Stockley

    2009-01-01

    Creina S StockleyThe Australian Wine Research Institute, Adelaide, South Australia, AustraliaAbstract: Population aging is associated with the increased incidence cancer and of degenerative diseases. Population aging is occurring on a global scale, with faster aging projected for the coming decades than has occurred in the past. Globally, the population aged 60 years and over is projected to nearly triple by 2050, while the population aged 80 years and over is projected to experience a more t...

  3. MRI of degenerative lumbar spine disease: comparison of non-accelerated and parallel imaging

    Energy Technology Data Exchange (ETDEWEB)

    Noelte, Ingo; Gerigk, Lars; Brockmann, Marc A.; Kemmling, Andre; Groden, Christoph [Medical Faculty Mannheim of the University of Heidelberg, Department of Neuroradiology, Mannheim (Germany)

    2008-05-15

    Parallel imaging techniques such as GRAPPA have been introduced to optimize image quality and acquisition time. For spinal imaging in a clinical setting no data exist on the equivalency of conventional and parallel imaging techniques. The purpose of this study was to determine whether T1- and T2-weighted GRAPPA sequences are equivalent to conventional sequences for the evaluation of degenerative lumbar spine disease in terms of image quality and artefacts. In patients with clinically suspected degenerative lumbar spine disease two neuroradiologists independently compared sagittal GRAPPA (acceleration factor 2, time reduction approximately 50%) and non-GRAPPA images (25 patients) and transverse GRAPPA (acceleration factor 2, time reduction approximately 50%) and non-GRAPPA images (23 lumbar segments in six patients). Comparative analyses included the minimal diameter of the spinal canal, disc abnormalities, foraminal stenosis, facet joint degeneration, lateral recess, nerve root compression and osteochondrotic vertebral and endplate changes. Image inhomogeneity was evaluated by comparing the nonuniformity in the two techniques. Image quality was assessed by grading the delineation of pathoanatomical structures. Motion and aliasing artefacts were classified from grade 1 (severe) to grade 5 (absent). There was no significant difference between GRAPPA and non-accelerated MRI in the evaluation of degenerative lumbar spine disease (P > 0.05), and there was no difference in the delineation of pathoanatomical structures. For inhomogeneity there was a trend in favour of the conventional sequences. No significant artefacts were observed with either technique. The GRAPPA technique can be used effectively to reduce scanning time in patients with degenerative lumbar spine disease while preserving image quality. (orig.)

  4. Physiotherapy in degenerative cerebellar ataxias: utilisation, patient satisfaction, and professional expertise.

    Science.gov (United States)

    Fonteyn, Ella M R; Keus, Samyra H J; Verstappen, Carla C P; van de Warrenburg, Bart P C

    2013-12-01

    Physiotherapy plays an important role in the management of patients with degenerative cerebellar ataxias. However, our insight in the quantity and quality of physiotherapy prescription in this group of patients is incomplete. The purposes of this study were to investigate the utilization of physiotherapy and patient satisfaction in patients with degenerative ataxias in The Netherlands and to examine the level of expertise and needs of physiotherapists treating ataxia patients. Questionnaires were sent to members of the Dutch association for patients with degenerative cerebellar ataxias (n = 532). In addition, 181 questionnaires were sent to the physiotherapists who had recently treated the patients who responded. Eventually, 317 questionnaires from patients (60 %) and 114 questionnaires from physiotherapists (63 %) could be used for further analysis. Sixty-four percent of the patients were currently treated by a physiotherapist. Their median treatment duration was 5 years. Nineteen percent of the patients had never been referred, often despite the presence of limitations in daily activities. On the other hand, some participants without reported limitations had received physiotherapy. In general, participants were satisfied with their physiotherapist. The most reported treatment goals were improvement or maintenance of balance, general physical condition, and mobility. Physiotherapists reported lack of ataxia-specific expertise and expressed the need for education and evidence-based guidelines. Referral to and use of physiotherapy in patients with degenerative cerebellar ataxia in The Netherlands are currently inconsistent and not in agreement with the little scientific evidence available. Referral rates are high, but referrals and actual necessity are discrepant; treatment duration is long; and ataxia-specific expertise among physiotherapists is insufficient. Evidence-based recommendations and specific training of physiotherapists are needed.

  5. Radiographic evaluation of the use of transverse traction device in vertebral arthrodesis for degenerative diseases

    OpenAIRE

    Edgar Takao Utino; João Paulo Machado Bergamaschi; Luciano Antonio Nassar Pellegrino; Ricardo Shigueaki Galhego Umeta; Maria Fernanda Silber Caffaro; Robert Meves; Osmar Avanzi

    2014-01-01

    OBJECTIVE: Perform radiographic analysis of the use of Transverse Traction Device (DTT) with respect to fusion rate in patients submitted to vertebral arthrodesis for degenerative lumbar diseases. METHODS: We selected x-ray images on anteroposterior, lateral and oblique views and with maximum flexion and extension dynamics of 23 patients submitted to posterolateral arthrodesis of the lumbar spine with a minimum follow-up period of six months. The images were evaluated and classified by the ...

  6. Prevalence and Prognosis of Anemia in Dogs with Degenerative Mitral Valve Disease

    OpenAIRE

    Yu, Ivarosa Bing-Ye; Huang, Hui-Pi

    2016-01-01

    In humans, heart failure (HF) and renal insufficiency (RI) have negative reciprocal effects, and anemia can exacerbate their progression. In this retrospective study, the prevalence and prognostic significance of anemia in 114 dogs with degenerative mitral valve disease (DMVD) was investigated. Pretreatment clinical parameters, prevalence of anemia and azotemia, and survival time were analyzed in relation to HF severity. The prevalence of anemia was highest in dogs with the modified New York ...

  7. Electromagnetic fields in the treatment of chronic lower back pain in patients with degenerative disc disease

    OpenAIRE

    Arneja, Amarjit S; Kotowich, Alan; Staley, Doug; Summers, Randy; Tappia, Paramjit S

    2016-01-01

    Aim: To examine the effects of low-amplitude, low frequency electromagnetic field therapy (EMF) therapy in patients with persistent chronic lower back pain associated with degenerative disc disease. Design: Double-blind, randomized and placebo controlled. Intervention: EMF using a medical device resonator; control group underwent same procedures, except the device was turned off. Outcome measures: Pain reduction and mobility. Results: Improvements in overall physical health, social functionin...

  8. Physical esercise and its prescription in patients with chronic degenerative diseases

    OpenAIRE

    Gómez, Rossana; Faculdade de Ciências, Universidade Estadual Paulista. São Paulo, Brasil. Magíster en Educación Física.; Monteiro, Henrique; Faculdade de Ciências, Universidade Estadual Paulista. São Paulo, Brasil. Doctor en educación física.; Cossio-Bolaños, Marco Antonio; Instituto del Deporte Universitario, Universidad Nacional de San Agustín. Arequipa, Perú. Faculdade de Educação Física, Universidade Estadual de Campinas. São Paulo, Brasil. Magíster en Educación Física.; Fama-Cortez, Domingo; Facultad de Medicina, Universidad de Córdova. Cordova, España. Médica.; Zanesco, Angelina; Instituto de Biociencias, Universidade Estadual Paulista. São Paulo, Brasil. Doctor en educación física.

    2010-01-01

    Chronic degenerative diseases constitute one of the main causes of death at a global level, and their significant increase has alerted many countries, which are taking measures to reduce risk factors, some of which are modifiable; being the regular exercise a means of prevention and rehabilitation of these diseases. The objective of this revision is to analyze the necessary parameters to take into account for the prescription of an exercise program in patients with obesity, high blood pressur...

  9. Current concepts on spinal arthrodesis in degenerative disorders of the lumbar spine

    OpenAIRE

    Lykissas, Marios G; Aichmair, Alexander

    2013-01-01

    Back pain is a common chronic disorder that represents a large burden for the health care system. There is a broad spectrum of available treatment options for patients suffering from chronic lower back pain in the setting of degenerative disorders of the lumbar spine, including both conservative and operative approaches. Lumbar arthrodesis techniques can be divided into sub-categories based on the part of the vertebral column that is addressed (anterior vs posterior). Furthermore, one has to ...

  10. Sagittal balance disorders in severe degenerative spine. Can we identify the compensatory mechanisms?

    Science.gov (United States)

    Barrey, Cédric; Roussouly, Pierre; Perrin, Gilles; Le Huec, Jean-Charles

    2011-09-01

    Aging of the spine is characterized by facet joints arthritis, degenerative disc disease and atrophy of extensor muscles resulting in a progressive kyphosis. Recent studies confirmed that patients with lumbar degenerative disease were characterized by an anterior sagittal imbalance, a loss of lumbar lordosis and an increase of pelvis tilt. The aim of this paper was thus to describe the different compensatory mechanisms which are observed in the spine, pelvis and/or lower limbs areas for patients with severe degenerative spine. We reviewed all the compensatory mechanisms of sagittal unbalance described in the literature. According to the severity of the imbalance, we could identify three different stages: balanced, balanced with compensatory mechanisms and imbalanced. For the two last stages, the compensatory mechanisms permitted to limit consequences of lumbar kyphosis on the global sagittal alignment. Reduction of thoracic kyphosis, intervertebral hyperextension, retrolisthesis, pelvis backtilt, knee flessum and ankle extension were the main mechanisms described in the literature. The basic concept of these compensatory mechanisms was to extend adjacent segments of the kyphotic spine allowing for compensation of anterior translation of the axis of gravity. To avoid underestimate the severity of the degenerative spine disorder, it thus seems important to recognize the different compensatory mechanisms from the upper part of the trunk to the lower limbs. We propose a three steps algorithm to analyse the balance status and determine the presence or not of these compensatory mechanisms: measurement of pelvis incidence, assessment of global sagittal alignment and analysis of compensatory mechanisms successively in the spine, pelvis and lower limbs areas.

  11. New Scattered Disk Object and Centaur Colors

    Science.gov (United States)

    Brucker, Melissa; Wilcox, P.; Stansberry, J.

    2013-10-01

    We report B, V, and R magnitudes for scattered disk objects and centaurs from observations taken in December 2011 and August 2013 using the Lowell Observatory Perkins Telescope with PRISM and observations taken in March 2012 at the Vatican Advanced Technology Telescope (VATT) on Mt. Graham, Arizona. Targeted scattered disk objects include 2002 CY224, 2003 UY117, 2006 QJ181, 2008 CT190, 2009 YG19, 2010 FD49, 2010 VZ98. Targeted centaurs include 2002 QX47, 2005 UJ438, 2006 UX184, and 2007 RH283. We will determine if the resultant centaur colors follow the bimodal distribution (B-R either red or gray) previously detected. We will also compare the resultant scattered disk object colors to those published for other scattered disk objects. This work is based on observations with the Perkins Telescope at Lowell Observatory, and with the VATT: The Alice P. Lennon Telescope and the Thomas J. Bannan Astrophysics Facility.

  12. Stochastic oscillations of general relativistic disks

    CERN Document Server

    Harko, Tiberiu

    2012-01-01

    We analyze the general relativistic oscillations of thin accretion disks around compact astrophysical objects interacting with the surrounding medium through non-gravitational forces. The interaction with the external medium (a thermal bath) is modeled via a friction force, and a random force, respectively. The general equations describing the stochastically perturbed disks are derived by considering the perturbations of trajectories of the test particles in equatorial orbits, assumed to move along the geodesic lines. By taking into account the presence of a viscous dissipation and of a stochastic force we show that the dynamics of the stochastically perturbed disks can be formulated in terms of a general relativistic Langevin equation. The stochastic energy transport equation is also obtained. The vertical oscillations of the disks in the Schwarzschild and Kerr geometries are considered in detail, and they are analyzed by numerically integrating the corresponding Langevin equations. The vertical displacement...

  13. Radiation-Driven Warping. 2; Nonisothermal Disks

    Science.gov (United States)

    Maloney, Philip R.; Begelman, Mitchell C.; Nowak, Michael A.

    1998-01-01

    Recent work by Pringle and by Maloney, Begelman, & Pringle has shown that geometrically thin, optically thick, accretion disks are unstable to warping driven by radiation torque from the central source. This work was confined to isothermal (i.e., surface density Sigma varies as R(sup -3/2) disks. In this paper we generalize the study of radiation-driven warping to include general power-law surface density distributions, Sigma varies as R(sup -delta).We consider the range from Delta = 3/2 (the isothermal case) to Delta = -3/2, which corresponds to a radiation-pressure-supported disk; this spans the range of surface density distributions likely to be found in real astrophysical disks. In all cases there are an infinite number of zero-crossing solutions (i.e., solutions that cross the equator), which are the physically relevant modes if the outer boundary of the disk is required to lie in a specified plane. However, unlike the isothermal disk, which is the degenerate case, the frequency eigenvalues for Delta does not equal 3/2 are all distinct. In all cases the location of the zero moves outward from the steady state (pure precession) value with increasing growth rate; thus, there is a critical minimum size for unstable disks. Modes with zeros at smaller radii are damped. The critical radius and the steady state precession rate depend only weakly on Delta. An additional analytic solution has been found for Delta = 1. The case Delta = 1 divides the solutions into two qualitatively different regimes. For Delta greater than or equal to 1, the fastest growing modes have maximum warp amplitude, close to the disk outer edge, and the ratio of Beta(sub max) to the warp amplitude at the disk inner edge, Beta(sub o), is much greater than 1. For Delta less than 1, Beta(sub max/Beta(sub o) approximately equals 1, and the warp maximum steadily approaches the origin as Delta decreases. This implies that nonlinear effects must be important if the warp extends to the disk inner edge

  14. Accretion disks around a mass with quadrupole

    CERN Document Server

    Abishev, Medeu; Quevedo, Hernando; Toktarbay, Saken

    2015-01-01

    We consider the stability properties of test particles moving along circular orbits around a mass with quadrupole. We show that the quadrupole modifies drastically the properties of an accretion disk made of such test particles.

  15. Foundations of Black Hole Accretion Disk Theory

    National Research Council Canada - National Science Library

    Abramowicz, Marek A; Fragile, P. Chris

    2013-01-01

    This review covers the main aspects of black hole accretion disk theory. We begin with the view that one of the main goals of the theory is to better understand the nature of black holes themselves...

  16. Analytic Creep Durability of Rotating Uniform Disks

    Directory of Open Access Journals (Sweden)

    Yuriy Nyashin

    1998-01-01

    Full Text Available Turbine disks of aircraft engines in operation are subjected to alternating thermocyclic deformation under high temperatures. Operation gives rise to sufficiently high stresses and subsequent creep damaging effects.

  17. Magnetohydrodynamic Origin of Jets from Accretion Disks

    CERN Document Server

    Lovelace, R V E; Koldoba, A V

    1999-01-01

    A review is made of recent magnetohydrodynamic (MHD) theory and simulations of origin of jets from accretion disks. Many compact astrophysical objects emit powerful, highly-collimated, oppositely directed jets. Included are the extra galactic radio jets of active galaxies and quasars, and old compact stars in binaries, and emission line jets in young stellar objects. It is widely thought that these different jets arise from rotating, conducting accretion disks threaded by an ordered magnetic field. The twisting of the magnetic field by the rotation of the disk drives the jets by magnetically extracting matter, angular momentum, and energy from the accretion disk. Two main regimes have been discussed theoretically, hydromagnetic winds which have a significant mass flux, and Poynting flux jets where the mass flux is negligible. Over the past several years, exciting new developments on models of jets have come from progress in MHD simulations which now allow the study of the origin - the acceleration and collima...

  18. Interstellar Gas and a Dark Disk

    Science.gov (United States)

    Kramer, Eric David; Randall, Lisa

    2016-10-01

    We introduce a potentially powerful method for constraining or discovering a thin dark matter disk in the Milky Way. The method relies on the relationship between the midplane densities and scale heights of interstellar gas being determined by the gravitational potential, which is sensitive to the presence of a dark disk. We show how to use the interstellar gas parameters to set a bound on a dark disk and discuss the constraints suggested by the current data. However, current measurements for these parameters are discordant, with the uncertainty in the constraint being dominated by the molecular hydrogen midplane density measurement, as well as by the atomic hydrogen velocity dispersion measurement. Magnetic fields and cosmic ray pressure, which are expected to play a role, are uncertain as well. The current models and data are inadequate to determine the disk's existence, but taken at face value, may favor its existence depending on the gas parameters used.

  19. Observations of Solids in Protoplanetary Disks

    CERN Document Server

    Andrews, Sean M

    2015-01-01

    This review addresses the state of research that employs astronomical (remote sensing) observations of solids ("dust") in young circumstellar disks to learn about planet formation. The intention is for it to serve as an accessible, introductory, pedagogical resource for junior scientists interested in the subject. After some historical background and a basic observational primer, the focus is shifted to the three fundamental topics that broadly define the field: (1) demographics -- the relationships between disk properties and the characteristics of their environments and hosts; (2) structure -- the spatial distribution of disk material and its associated physical conditions and composition; and (3) evolution -- the signposts of key changes in disk properties, including the growth and migration of solids and the impact of dynamical interactions with young planetary systems. Based on the state of the art results in these areas, suggestions are made for potentially fruitful lines of work in the near future.

  20. Accretion disks around a mass with quadrupole

    Science.gov (United States)

    Abishev, M.; Boshkayev, K.; Quevedo, H.; Toktarbay, S.

    We consider the stability properties of circular orbits of test particles moving around a mass with quadrupole. We show that the quadrupole modifies drastically the properties of an accretion disk made of such test particles.