Multilead ECG data compression by multirate signal processing and transform domain coding techniques

Ankara : The Department of Electrical and Electronics Engineering and the Institute of Engineering and Sciences of Bilkent Univ., 1991.Thesis (Master's) -- Bilkent University, 1991.Includes bibliographical references leaves 50-53.This thesis presents two data compression methods for digital electrocardiogram (EGG) signals. The first method is proposed for the compression of single lead EGG data. Various coding technicgies such as Sub-Band Transform and Variable Length Godings are used to realize that purpose. Data size reduction which is a problem in EGG databases is chosen as an application and successful results are achieved during simulations. The second algorithm is proposed for the multilead EGG data compression. A linear transform is applied to samples of the eight standard EGG lead signals. The resulting transform domain signals are compressed using various coding methods, including multi-rate signal processing and transform domain techniques. Higher compression ratios are achieved compared to the single channel compression techniques.Aydın, M CengizM.S

CT taramalarında hastanın kilosuna göre alınan dozun değişimi

Tüm radyoterapi işlemi sırasında çekilen Bilgisayarlı Tomografi (BT) görüntüleri, tedavi portalı tasarımı, planlaması ve hasta pozisyonunun sağlanması için önemlidir. Ancak bu BT taramalarında hastanın aldığı doz, planlama doz hesaplamalarına dahil edilmez. Özellikle adaptif tedavilerde kritik organların limit dozlarının hesaplanmasında günlük BT taramalarından alınan doz çok önemli hale gelmektedir. Bu çalışmada, Monte Carlo tekniğinin kullanıldığı NCICT kodu ile hastaların bazı kritik organları olan kalp ve karaciğerin aldığı dozun hastanın ağırlığına göre değişimi araştırıldı.Computed Tomography (CT) images taken during whole radiotherapy procedure is important for treatment planning, portal design and providing patient position. However, the dose received by the patient in these CT scans are not included in the planning dose calculations. Especially in adaptive treatments, the dose received from daily CT scan becomes very important in calculation of the limit doses of critical organs. In this study, with the NCICT code, which use the Monte Carlo technique, the change of the dose absorbed by some critical organs of the patients, namely the heart and liver, according to the weight of the patient, was investigated

Consequences of neurite transection in vitro

WOS: 000309967300004PubMed ID: 20121423In order to quantify degenerative and regenerative changes and analyze the contribution of multiple factors to the outcome after neurite transection, we cultured adult mouse dorsal root ganglion neurons, and with a precise laser beam, we transected the nerve fibers they extended. Cell preparations were continuously visualized for 24 h with time-lapse microscopy. More distal cuts caused a more elongated field of degeneration, while thicker neurites degenerated faster than thinner ones. Transected neurites degenerated more if the uncut neurites of the same neuron simultaneously degenerated. If any of these uncut processes regenerated, the transected neurites underwent less degeneration. Regeneration of neurites was limited to distal cuts. Unipolar neurons had shorter regeneration than multipolar ones. Branching slowed the regenerative process, while simultaneous degeneration of uncut neurites increased it. Proximal lesions, small neuronal size, and extensive and rapid neurite degeneration were predictive of death of an injured neuron, which typically displayed necrotic rather than apoptotic form. In conclusion, this in vitro model proved useful in unmasking many new aspects and correlates of mechanically-induced neurite injury.Yuzuncu Yil University Directorate of Scientific Research Projects [TF073]This study was supported by the Yuzuncu Yil University Directorate of Scientific Research Projects (grant no. TF073)

Acute necrotizing encephalopathy associated with RANBP2 mutation: Value of MRI findings for diagnosis and intervention

Introduction: Acute necrotizing encephalopathy (ANEC) is a rare entity characterized by encephalopathy following a febrile illness. Most patients are sporadic; however, recurrent and familial cases have been associated with RAN-binding protein 2 (RANBP2) mutation. Well-defined MRI findings can even be life-saving with early diagnosis and treatment. Methods: In this article, nine pediatric cases diagnosed with ANEC1 both clinically and radiologically, and with least one variation in the RANBP2 gene, are presented. Results: All patients were previously healthy and presented with encephalopathy after an acute febrile infection. The patients of 44% had a similar attack history in their family. Influenza A/B was detected in 7 patients (78%). One patient was admitted at age 32 years old. The first clinical findings of patients were encephalopathy (100%), seizure (44%), vision problems (33%), ataxia (11%), and monoplegia (11%). Recurrent attacks were seen in two (22%) patients. Brain MRI findings including bilateral thalamus, external capsules, and brainstem involvements were highly suggestive for RANBP2 mutation. Based on MRI findings, genetic analyses were quickly performed and confirmed. All of the patients were treated with empirical encephalitis treatment, oseltamivir, intravenous immunoglobulin (IVIG), high-dose steroid and, if necessary, plasmapheresis, but three (33%) patients died despite treatment. Conclusion: ANEC associated with RANBP2 mutation may occur early or late-onset and can be recurrent and fatal. Therefore, early diagnosis and treatment have the potential to modify the severity of this encephalopathy. Well-defined MRI findings are highly instructive for early diagnosis

I-131 radyoizotop aktivitelerinin nükleer tıpta kullanılan organ dozu üzerine etkisi

Hayatta radyasyona maruz kalmanın birçok yolu vardır. Özellikle tıbbi uygulamalar, şiddetli maruziyetin en önemli sebebidir. Tıbbi uygulamalarda Bilgisayarlı Tomografi (BT) taramaları ilk sırada yer alırken, nükleer tıp ikinci sırada yer almaktadır. Tabii ki, maruz kalan doku ve dolayısıyla organlar tarafından emilen doz, sağlığa yönelik risklerle doğru orantılıdır. Nükleer tıpta tedavi amaçlı vücuda yerleştirilen radyoizotoplar nedeniyle sadece tümörün bulunduğu organ ve/veya dokulara değil, çevredeki diğer organ ve dokular az miktarda olsa da doz absorbe eder. Bu çalışmada erişkin fantomların (erkek ve dişi) tiroid bezine yerleştirilen iyot radyoizotop I-131'in aktivitelerine göre tiroid bezi, timüs ve lenf bezlerinin aldığı dozlardaki değişim Monte Carlo-tabanlı NCINM kodu ile araştırılmıştır.There are many ways to be exposed to radiation in life. Medical applications, in particular, are the most important form of severe exposure. In medical applications, Computed Tomography (CT) scans are in the first place, while nuclear medicine is in the second place. Of course, the dose absorbed by the exposed tissue and therefore the organs is directly proportional to the risks to health. In nuclear medicine, due to the radioisotopes placed in the body for therapeutic purposes, some doses are not given only to the organ and/or tissues where the tumor is placed, but also to other surrounding organ and tissues. In this study, the change in the doses received by the thyroid gland, thymus, and lymph nodes according to the activities of the iodine radioisotope I-131 placed in the thyroid gland of adult phantoms (both male and female) were investigated with the Monte Carlo-based code

Digital Transformation and Openness in the Turkish Higher Education System

This chapter introduces openness in education and open educational resources (OER) in Turkey. To better understand and conceptualize the Turkish case, there is a need to briefly introduce Turkish HE and how openness is perceived by Turkish Society. By 2021, the total population of Turkey is around 85 million and approximately 10% of its population (around 8 million) attends higher education (HE). HE in Turkey is delivered through face-to-face, distance, and open education modalities. In this context, it should be noted that due to Turkish regulations, there are distinct differences in the definition of distance education and open education. Accordingly, open education offers open admissions with minimal entry requirements and flexible learning opportunities (e.g., self-paced, attendance is not required), on the other hand, distance education offers partly flexible admissions (e.g., predefined entry requirements, attendance is required, students should pay for the courses). The demand for HE is high, but the number of accepted students is relatively low compared to the total demand. As such, open education is a viable solution for the Turkish HE system

Effects of Proton Pump Inhibitors and H2 Receptor Antagonists on the Ileum Motility

Objectives. To investigate the effects of proton pump inhibitors (PPIs) and H2 receptor antagonists on ileum motility in rats with peritonitis and compare changes with control group rats. Methods. Peritonitis was induced by cecal ligation and puncture in 8 rats. Another of 8 rats underwent a sham operation and were accepted as controls. Twenty-four hours later after the operation, the rats were killed, and their ileum smooth muscle was excised and placed in circular muscle direction in a 10 mL organ bath. Changes in amplitude and frequency of contractions were analyzed before and after PPIs and H2 receptor blockers. Results. PPI agents decreased the motility in a dose-dependent manner in ileum in both control and intraabdominal sepsis groups. While famotidine had no significant effect on ileum motility, ranitidine and nizatidine enhanced motility in ileum in both control and intraabdominal sepsis groups. This excitatory effect of H2 receptor antagonists and inhibitor effects of PPIs were significantly high in control group when compared to the peritonitis group. The inhibitor effect of pantoprazole on ileum motility was significantly higher than the other two PPI agents. Conclusions. It was concluded that H2 receptor antagonists may be more effective than PPIs for recovering the bowel motility in the intraabdominal sepsis situation

Vagal Nerve Schwannoma Clinically Mimicking Gastrointestinal Stromal Tumor: Report of a Case

Introduction: Mesenchymal tumors of the gastrointestinal (GI) tract are mainly comprised of a spectrum of spindle cell tumors which include gastrointestinal stromal tumors (GISTs), leiomyomas or leiomyosarcomas, and schwannomas. As all of these tumors of the GI are located in the submucosal layer of the bowell wall, differential diagnosis is very difficult. Histopathological evaluation using immunohistochemical staining is required for the definitive diagnosis.Presentation of case: A 20-year-old female patient was presented with an upper abdominal pain and dyspepsia since 2 months duration.This case  is initially thought as GIST but finally diagnosed as vagal nerve schwannoma by histopathological evaluation after resection of the mass.Conclusion: Schwannomas should be considered in the differential diagnosis of other mesenchimal tumors, such as gastrointestinal stromal tumors and leiomyomas or leiomyosarcomas, indeed it can grow in any part of the peripheral nerves along the gastrointestinal tract. Histopathological evaluation including immunohistochemical staining is required for the definitive diagnosis