441 research outputs found

    Comments on Sweeny and Gliozzi dynamics for simulations of Potts models in the Fortuin-Kasteleyn representation

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    We compare the correlation times of the Sweeny and Gliozzi dynamics for two-dimensional Ising and three-state Potts models, and the three-dimensional Ising model for the simulations in the percolation prepresentation. The results are also compared with Swendsen-Wang and Wolff cluster dynamics. It is found that Sweeny and Gliozzi dynamics have essentially the same dynamical critical behavior. Contrary to Gliozzi's claim (cond-mat/0201285), the Gliozzi dynamics has critical slowing down comparable to that of other cluster methods. For the two-dimensional Ising model, both Sweeny and Gliozzi dynamics give good fits to logarithmic size dependences; for two-dimensional three-state Potts model, their dynamical critical exponent z is 0.49(1); the three-dimensional Ising model has z = 0.37(2).Comment: RevTeX, 4 pages, 5 figure

    Nonoperative Treatment of Thoracic and Lumbar Spine Fractures:A Prospective Randomized Study of Different Treatment Options

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    Objectives: To evaluate and compare nonoperative treatment methods for traumatic thoracic and lumbar compression fractures and burst fractures.Design: Prospective randomized controlled trial with long-term follow-up.Setting: Two general hospitals in the Netherlands.Patients/Participants: Patients with a traumatic thoracic or lumbar spine fracture, without neurologic damage, with less than 50% loss of height of the anterior column and less than 30% reduction of the spinal canal were included.Intervention: Patients in the compression group were randomized to physical therapy and postural instructions, a brace for 6 weeks, or a Plaster of Paris cast for 6 or 12 weeks. Patients in the burst group received a brace or a Plaster of Paris cast, both for 12 weeks.Main Outcome Measurements: Follow-up examinations included radiographs, Visual Analogue Scores for toleration of treatment and persistent pain, and an Oswestry Disability Index at long-term follow-up.Results: There were 133 patients: 108 in the compression group and 25 in the burst group. For compression fractures, physical therapy and brace were considered the most tolerable. Brace therapy scored significantly better on the Visual Analogue Scores for residual pain and on the Oswestry Disability Index. None of the treatments had any significant effect on the residual deformity measurements. For burst fractures, no significant differences were found.Conclusions: Brace treatment with supplementary physical therapy is the treatment of choice for patients with compression fractures of the thoracic and lumbar spine. Furthermore, more than 20% of all patients had moderate or severe back pain at long-term follow-up.</p

    The Development of a Universally Accepted Sacral Fracture Classification: A Survey of AOSpine and AOTrauma Members.

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    Study Design Survey study. Objective To determine the global perspective on controversial aspects of sacral fracture classifications. Methods While developing the AOSpine Sacral Injury Classification System, a survey was sent to all members of AOSpine and AOTrauma. The survey asked four yes-or-no questions to help determine the best way to handle controversial aspects of sacral fractures in future classifications. Chi-square tests were initially used to compare surgeons\u27 answers to the four key questions of the survey, and then the data was modeled through multivariable logistic regression analysis. Results A total of 474 surgeons answered all questions in the survey. Overall 86.9% of respondents felt that the proposed hierarchical nature of injuries was appropriate, and 77.8% of respondents agreed that that the risk of neurologic injury is highest in a vertical fracture through the foramen. Almost 80% of respondents felt that the separation of injuries based on the integrity of L5-S1 facet was appropriate, and 83.8% of surgeons agreed that a nondisplaced sacral U fracture is a clinically relevant entity. Conclusion This study determines the global perspective on controversial areas in the injury patterns of sacral fractures and demonstrates that the development of a comprehensive and universally accepted sacral classification is possible

    Sacral Fractures and Associated Injuries.

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    STUDY DESIGN: Literature review. OBJECTIVE: The aim of this review is to describe the injuries associated with sacral fractures and to analyze their impact on patient outcome. METHODS: A comprehensive narrative review of the literature was performed to identify the injuries associated with sacral fractures. RESULTS: Sacral fractures are uncommon injuries that result from high-energy trauma, and that, due to their rarity, are frequently underdiagnosed and mistreated. Only 5% of sacral fractures occur in isolation. Injuries most often associated with sacral fractures include neurologic injuries (present in up to 50% of sacral fractures), pelvic ring disruptions, hip and lumbar spine fractures, active pelvic/ abdominal bleeding and the presence of an open fracture or significant soft tissue injury. Diagnosis of pelvic ring fractures and fractures extending to the lumbar spine are key factors for the appropriate management of sacral fractures. Importantly, associated systemic (cranial, thoracic, and abdominopelvic) or musculoskeletal injuries should be promptly assessed and addressed. These associated injuries often dictate the management and eventual outcome of sacral fractures and, therefore, any treatment algorithm should take them into consideration. CONCLUSIONS: Sacral fractures are complex in nature and often associated with other often-missed injuries. This review summarizes the most relevant associated injuries in sacral fractures and discusses on their appropriate management

    Схемотехническое моделирование и синтез активных СВЧ-фильтров на полевых транзисторах Шоттки

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    Разработаны схемы активных СВЧ-фильтров, пригодных для исполнения в виде гибридной или полупроводниковой микросхемы

    Громадська робота як чинник повсякденного життя вчителя

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    Treatment and reconstruction of large bone defects, delayed unions, and nonunions is challenging and has resulted in an ongoing search for novel tissue-engineered therapies. Bone morphogenetic protein-2 (BMP-2) gene therapy is a promising strategy to provide sustained production of BMP-2 locally. Alginate polymer-based nonviral gene therapy with BMP-2 plasmid DNA (pBMP-2) in constructs with multipotent mesenchymal stromal cells (MSCs) has resulted in prolonged gene expression and bone formation in vivo. To further translate this technology toward larger animal models, important issues remain to be investigated, such as the necessity of seeded cells as a target for gene therapy. For that purpose, a large animal-screening model in an orthotopic location, with fully separated chambers, was investigated. Four cylinder-shaped implants were placed in the iliac crests of ten goats. Polycaprolactone tubes around each implant allowed bone ingrowth from the underlying bone and bone marrow and ensured separation of the experimental conditions. An empty tube showed low levels of spontaneous bone ingrowth, and implantation of autologous bone indicated proper bone function with respect to remodeling and resorption. Control ceramic scaffolds were compared to scaffolds containing pBMP-2 either or not combined with seeded MSCs. Fluorochrome incorporation evaluated at 3, 6, and 9 weeks and histomorphometry at 12 weeks after implantation revealed clear differences between the groups, with pBMP-2 combined with MSCs being the most effective. The BMP-2 was demonstrated in a variety of bone-residing cells through immunohistochemistry. Further analysis indicated that multinucleated giant cells might have an important role in transgene expression. Taken together, this work introduces a large animal model for studying bone formation at multiple sites simultaneously in an orthotopic location. The model appeared robust, showed no neighboring effects, and demonstrated effectivity of combined cell and gene therapy

    Reliability and Validity of the German Version of the AO Spine Patient Reported Outcome Spine Trauma Questionnaire.

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    STUDY DESIGN A single-center validation study. OBJECTIVE To translate and cross-culturally adapt the AO Spine PROST (Patient Reported Outcome Spine Trauma) into German, and to test its psychometric properties among German-speaking Swiss spine trauma patients. METHODS Patients were recruited from a level-1 Swiss trauma center. Next to the AO Spine PROST, the EQ-5D-3L questionnaire was used for concurrent validity. Questionnaires were filled out at two-time points for test-retest reliability. Patient characteristics were analyzed using descriptive statistics. For content validity, floor, and ceiling effects, as well as any irrelevant and missing questions were analyzed. Construct validity of the AO Spine PROST questionnaire to the EQ-5D-3L was tested using Spearman correlation tests. RESULTS The AOSpine PROST was translated and adapted into German using established guidelines. We included 179 patients. The floor effect for all items was well within the optimal range (below 15%), while the ceiling effect of seven items was within the optimal range. None of the items displayed a problematic floor or ceiling effect. The overall test-retest reliability of the total PROST score was excellent, with an ICC of .83 (95% CI .69-.91). The Spearman correlation coefficient between the total PROST summary score and EQ-5D-3 L was ρ = .63. CONCLUSIONS The German version of the AO Spine PROST questionnaire demonstrated very good validity and reliability results

    Diagnosis of diffuse idiopathic skeletal hyperostosis with chest computed tomography:inter-observer agreement

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    To evaluate and improve the interobserver agreement for the CT-based diagnosis of diffuse idiopathic skeletal hyperostosis (DISH). Six hundred participants of the CT arm of a lung cancer screening trial were randomly divided into two groups. The first 300 CTs were scored by five observers for the presence of DISH based on the original Resnick criteria for radiographs. After analysis of the data a consensus meeting was organised and the criteria were slightly modified regarding the definition of 'contiguous', the definition of 'flowing ossifications' and the viewing plane and window level. Subsequently, the second set of 300 CTs was scored by the same observers. kappa >= 0.61 was considered good agreement. The 600 male participants were on average 63.5 (SD 5.3) years old and had smoked on average 38.0 pack-years. In the first round kappa values ranged from 0.32 to 0.74 and 7 out of 10 values were below 0.61. After the consensus meeting the interobserver agreement ranged from 0.51 to 0.86 and 3 out of 10 values were below 0.61. The agreement improved significantly. This is the first study that reports interobserver agreement for the diagnosis of DISH on chest CT, showing mostly good agreement for modified Resnick criteria. . DISH is diagnosed on fluoroscopic and radiographic examinations using Resnick criteria . Evaluation of DISH on chest CT was modestly reproducible with the Resnick criteria . A consensus meeting and Resnick criteria modification improved inter-rater reliability for DISH . Reproducible CT criteria for DISH aids research into this poorly understood entity

    Уровень провоспалительных цитокинов внутриматочных смывов при гиперплазиях эндометрия

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    Проведено вивчення змін рівня прозапальних цитокінів ІЛ -1ß, ІЛ -6 та ФНП-α в маткових змивах у жінок з різними видами гіперплазій ендометрію. Встановлено, що формування гіперплазії ендометрію супроводжується активацією прозапальних цитокінів. Найбільш виражені зміни виявлені при комплексній гіперплазії ендометрію. Запальний процес в урогенітальної системі сприяє більш вираженому зростанню рівня цитокінів в маткових змивах. Оцінка вираженості змін в рівні цитокінів маткових змивів може використовуватися в якості додаткового критерію, що характеризує гіперплазії ендометрію, для оцінки формування запальних змін в ендометрії при його гіперплазії і для оцінки прогнозу перебігу гіперплазій.Levels of proinflammatory cytokines IL-1ß, IL-6 and TNF-α in uterine lavage fluid of women with different types of endometrial hyperplasia were studied. It is established that the formation of endometrial hyperplasia is associated with activation of proinflammatory cytokines. The most intensive changes were found in complex endometrial hyperplasia. Inflammation in the urogenital system leads to more intensive increase of cytokines level in the uterine washout. Investigation of changes in cytokines levels in uterine lavage fluid can be used as an additional criterion for characteristics of endometrial hyperplasia, to assess the formation of inflammatory changes in the endometrium and for prognosis of hyperplasia
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