323 research outputs found

    Simulated 3D Model of the Middle Ear for Theoretical and Practical Training for Students, Post-Graduate ENT Diseases Students and Beginning Otosurgeons

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    Post-graduate ENT diseases students and beginning otosurgeons go through a very important initial training period. The first steps in otosurgery are taken step by step. The transition from theoretical knowledge to temporal bone dissection courses is long and difficult. The lack of preliminary preparation vitiates and increases the cost of temporal bone dissection exercises.Simulated models bridge the gap between theory and practice and contribute to a more effective training.Aim: Developing a simulated 3D model of the mastoid process in real size and the part of the facial nerve passing through it; using a simulated 3D model of mastoid process for anatomical visualization of the hard to find and invisible structures of the middle ear and facial nerve and for nosological training.Material and methods:1. Cadaver temporal bone on which postauricular facial nerve decompression has been performed.2. Elaborating a silicone model based on a print taken from the operative cavity3. 3D printing of the models and colouring4. Putting electrical conductors and their connection to a tactile pointer and light indicatorsResults:The model:–– presents the hard to find and invisible microstructures of the middle ear and the part of the facial nerve passing through it–– allows work in two modes: anatomical and nosological–– contributes to more lasting preservation of knowledge, using the principle of active learning and training visual and tactile memory.Conclusion:The model is developed for tuition, precedes training models and can be improved. ---------------------------------------------------------------- Специализантите по УНГ болести и начинаещите отохирурзи преминават през много важен начален период на обучение. Първите стъпки в отохирургията се осъществяват step by step. Преходът от теоретични познания към курсовете по Temporal Bone Dissection е труден и продължителен. Липсата на предварителнаподготовка опорочава и оскъпява упражненията по дисекция на темпорална кост.Симулационните модели прехвърлят мост между теорията и практиката и допринасят за по-висока ефективност на обучението.Цел: Създаване на симулационен 3D модел в реални размери на processus mastoideus и частта на лицевия нерв, преминаваща през него; използване на симулационен 3D модел на processus mastoideus за анатомично онагледяване на трудно откриваемите и невидими структури на средното ухо и лицевия нерв и за нозологично обучение.Материал и методи:1. трупна темпорална кост, върху която е извършена Postauricular Facial Nerve decompression2. изработване на силиконов модел по взет отпечатък от оперативната кухина3. 3Д принтинг на моделите и оцветяване4. полагане на електрически проводници и свързването им към тактилна показалка и светлинни индикаториРезултати:Моделът:–– представя трудно откриваемите и невидими микроструктури на средното ухо и частта на лицевия нерв, преминаваща през него–– позволява работа в два режима: анатомичен и нозологичен–– допринася за по-трайно запазване на знанията, използвайки принципа на активното обучение и тренирането на зрителната и тактилната паметЗаключение:Моделът е създаден за обучение, предхожда моделите за тренинг и може да бъде усъвършенстван

    Superconductivity and superconducting order parameter phase fluctuations in a weakly doped antiferromagnet

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    The superconducting properties of a recently proposed phenomenological model for a weakly doped antiferromagnet are analyzed, taking into account fluctuations of the phase of the order parameter. In this model, we assume that the doped charge carriers can't move out of the antiferromagnetic sublattice they were introduced. This case corresponds to the free carrier spectra with the maximum at k=(±π/2,±π/2){\bf k}=(\pm \pi /2 ,\pm \pi /2), as it was observed in ARPES experiments in some of the cuprates in the insulating state [1]. The doping dependence of the superconducting gap and the temperature-carrier density phase diagram of the model are studied in the case of the dx2y2d_{x^{2}-y^{2}} pairing symmetry and different values of the effective coupling. A possible relevance of the results to the experiments on high-temperature superconductors is discussed.Comment: 16 pages, 4 figure

    Secondary peak on asymmetric magnetization loop of type-II superconductors

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    Asymmetric magnetization loops with a second peak effect were parameterized by the extended critical state model. The magnetic field distribution in a sample is considered. Expression is suggested for a peak of the critical current density and corresponding depression on field dependence of the depth of surface layer with equilibrium magnetization. These functions determine the width and the asymmetry of a magnetization loop. Asymmetry of the secondary peak height on magnetization branches for increasing and decreasing field is reproduced on the computed magnetization curves.Comment: 6 pages, 2 figures, Equation 6 is modified to be f=0 at B=

    Direct Ascription of Missing Categorical Values in Survey Research Data

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    The complete datasets are a prerequisite for sustainable analyses, robust an- alytics and unbiased interpretation of results. Missing values in a survey occur when no data value is stored for the variable in an observation. Missing data can have a significant effect on the conclusions that can be drawn from the data. Direct ascription is the process of replacing missing data with predicted values. The aim of this work is to describe an approach to direct ascription of missing categorical values in survey research data based both on the assumption that values in a data set are missing at random and on the implementation of the correspondence analysis

    Functional endoscopic sinus surgery (FESS) with navigation system in childhood – our experience. Presentation of clinical cases

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    Introduction: Functional endoscopic sinus surgery (FESS) is the gold minimally invasive standard in diagnosing and surgically treating many diseases of the nose and paranasal cavities. An advantage of FESS is the possibility of application in all age groups.Materials and methods: We observed pediatric patients attended the Otorhinolaryngology Clinic in the University Hospital “Dr. Georgi Stranski” – Pleven in 2021. FESS surgery was performed in the “Integrated interdisciplinary operating unit with navigation and telesurgery systems” at the Center of competence on personalised medicine, 3D and telemedicine, robotic and minimally invasive surgery „Leonardo da Vinci” in Medical University – Pleven.Clinical cases: Case 1: A 7-year-old male patient with orbital complication of rhinosinusitis, with left orbital preseptal cellulitis, without ophthalmoplegia or loss of vision, + ptosis of the eyelid and data on pansinuitis from CT images. Performed FESS found lysis of lamina papyracea with involvement of anterior and posterior ethmoidal cells. Postoperative treatment was done with Ceftriaxone 1g/12h i.v. for 7 days, nasal glucocorticoids and antihistamines.Case 2: A 17-year-old female patient with suggested primary ciliary dyskinesia with a recurrent rhinosinusitis, persistent nasal obstruction, and thick viscous secretions that did not respond to conservative treatment. Sweat test for cystic fibrosis (-). FESS reshaping of the natural openings of the maxillary sinuses and anterior ethmoidectomy were performed bilaterally.Conclusion: FESS is a minimally invasive method, which is suitable for application in pediatric patients. When applied by trained professionals, FESS with an integrated navigation system is optimal for the diagnosis and surgical treatment of chronic and acute rhinosinusitis in children

    Estimation of errors in text and data processing

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    The company Adiss Lab Lts. obtained 1 000 000 medical reports that are either in free form text, or in XML format. One of the main goals of their development is to integrate an algorithm for information extraction (IE) in their platform. The verification of the algorithm’s output for a report is done by a medical doctor (MD) for a certain fee. Validating the correctness of all data would be overwhelming and very expensive. Hence, the problem, as presented by the company, is to provide a method (algorithm) which determines the minimum amount of reports that will validate the correctness of the IE algorithm and a procedure for selecting these reports. In order to solve the problem we have considered an algorithm-centric approach uses active learning and semi-supervised learning

    Our experience in the surgical treatment of Obstructive Sleep Apnea

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    Background: Obstructive Sleep Apnea (OSA) is a sleep-related breathing disorder, leading to decreased quality of life, increased risk of cardiovascular morbidity and mortality, increased frequency of automobile accidents. Continuous positive airway pressure (CPAP) remains the first line of treatment for OSA. Many patients are unwilling or incapable to tolerate the treatment and therefore turn to surgical options to alleviate symptoms and sequela of the disease.Аim: To present our experience in the surgical treatment of OSA.Materials and Methods: 50 patients (48 male / 2 female) underwent surgical treatment for OSA in our clinic for a period of 10 years. Subjective complaints were evaluated by interview of the patient and partner pre- and postoperatively, with key factors studied being snoring level (visual analogue 1–10) and Epworth Sleepiness Scale (ESS). Objective data were Body Mass Index (BMI), nasal endoscopy, pre and postoperative polysomnographic data, rhinomanometry, Mallampati score, diagnostic imaging of the nose and sinuses.Results: The mean BMI of the patients was 29.8± 3.4. 21 patients had nasal obstruction for which they underwent surgical treatment. 5 patients had micro or retrognathia. 37 Pateints had a Mallampati score of 3 and 13 of 4. All 50 patients underwent Uvulopalatopharyngoplasty (UPPP) and 6 patients also had Radiofrequency tongue base reduction. There were no serious complications. Subjective improvement in the severity of the symptoms was obtained in 88% (44) of patients. Objective success was obtained in 56% (28) of the patients.Conclusions: Surgical treatment of OSA leads to a significant subjective improvement in the severity of symptoms and acceptable objective results. For maximal results a multidisciplinary approach is required for the complex treatment of OSA

    Profiling of VEGFs and VEGFRs as Prognostic Factors in Soft Tissue Sarcoma: VEGFR-3 Is an Independent Predictor of Poor Prognosis

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    BACKGROUND: In non-gastrointestinal stromal tumor soft tissue sarcoma (non-GIST STS) optimal treatment is surgery with wide resection margins. Vascular endothelial growth factors (VEGFs) and receptors (VEGFRs) are known to be key players in the initiation of angiogenesis and lymphangiogenesis. This study investigates the prognostic impact of VEGFs and VEGFRs in non-GIST STS with wide and non-wide resection margins. METHODS: Tumor samples from 249 patients with non-GIST STS were obtained and tissue microarrays were constructed for each specimen. Immunohistochemistry was used to evaluate the expressions of VEGF-A, -C and -D and VEGFR-1, -2 and -3. RESULTS: In the univariate analyses, VEGF-A (P=0.040) in the total material, and VEGF-A (P=0.018), VEGF-C (P=0.025) and VEGFR-3 (P=0.027) in the subgroup with wide resection margins, were significant negative prognostic indicators of disease-specific survival (DSS). In the multivariate analysis, high expression of VEGFR-3 (P=0.042, HR=1.907, 95% CI 1.024-3.549) was an independent significant negative prognostic marker for DSS among patients with wide resection margins. CONCLUSION: VEGFR-3 is a strong and independent negative prognostic marker for non-GIST STSs with wide resection margins

    The application of ultrasound examination in the treatment of Acute Sinusitis. Comparing X-ray to ultrasound of paranasal sinuses

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    Background: Acute rhinosinusitis (ARS) is one of the most common diseases encountered in the out-patient setting. X-ray of the paranasal sinuses is the gold standard in the diagnosis of ARS with its accessibility and accuracy. Ultrasound examination of the paranasal sinuses is a noninvasive diagnostic method which is an acceptable alternative in the follow-up of the treatment.Aim: To present the application of portable sinuson in the out-patient setting on patients with ARS and its effectiveness.Materials and Methods: 22 patients (12m/10f) underwent X-ray of the paranasal sinuses, which resulted in ARS. The results of the X-rays were compared with the ultrasound examination of the paranasal sinuses with a portable sinuson (SINUSULTRA ULTRAMAX). The examination was repeated on the 1-st and 2-nd week and 2 months after the treatment for ARS.Results: From the 22 patients – 10 were with unilateral maxillary sinusitis, 7 with bilateral sinusitis and 5 with pansinusitis. 5 (22%) false positives were registered from the ultrasound examination on the initial check-up, 3 (13%) false negatives were registered on the follow-ups on the 1-st and the 2-nd week, 2 (9%) false negatives were registered 2 months after the treatment for ARS.Conclusion: Ultrasound examination of the paranasal sinuses is a noninvasive, painless, fast and with an adequate degree of accuracy. It is a good alternative for children and pregnant women. Ultrasound examination can be applied in the follow-up of ARS
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