Correlation between the findings of expiratory high resolution computed tomography, respiratory function tests and tracheal index in chronic obstructive pulmonary disease

Objectives: In this study we aimed to investigate the relationship between expiratory HRCT findings, tracheal index (TI) and pulmonary function tests in patients with chronic obstructive pulmonary disease (COPD).Materials and methods: Sixty patients diagnosed with COPD in our hospital, department of pulmonary medicine, and 65 subjects complaining of cough with normal pulmonary function tests as a control group were enrolled in the study. All subjects were evaluated with HRCT. HRCT and pulmonary function tests were performed in same day and FEV1, FVC, FEV1/FVC values were recorded. Pearson Chi-Square, Independent Samples T test, and Mann Whitney U test were used for statistical evaluation.Results: Subjects’ mean age was 55.44±10.22 years. Bronchiectasis, bronchial wall thickening, emphysema, centrilobular bronchiolar thickening and air trapping were significantly higher in COPD group than control group. In patient group, TI values were lower than control group (p < 0.001). Also there was moderate negative relationship between TI and age (p = 0.00, r = -0.48).Conclusions: Expiratory HRCT findings and TI values show various degrees of relationship with pulmonary function test results in patients with COPD. Despite normal pulmonary function tests, pathological changes can be detected in expiratory HRCT scan

Design, Analysis and Performance Evaluation of Electrical Power Subsystem based on Triple-Junctions Solar PV Cells and SEPIC for a Conceptual 1u Cubesat Mission

This study aims to popularize low voltage power supply design especially for space satellite Cubesat mission and other portable consumer electronic devices. In this context, a preliminary design of an electrical power subsystem (EPS) is carried out for a conceptual 1u Cubesat mission in this paper. Mathematical modeling of the basic elements of the EPS is presented. Photovoltaic (PV) power generation system that is selected is made up of triple-junction solar cells, and the battery charging system based on lithium technology as well as the power conditioning converters are selected based on single ended primary inductance converter topology popularly abbreviated as SEPIC. Triple-junction solar PV cell results are verified by comparing with the datasheet values. A maximum power point tracking algorithm which is known as perturb and observe is implemented and proportional-integral controller is used for the SEPIC. All of these are well analyzed, mathematically modeled and simulated. Feasibility of the designed EPS is verified by comparing with similar devices from different manufacturers

Retrospective Evaluation Of MRI Findings Of Knee Joint In 255 Patients

Retrospective evaluation of knee MRI obtained from 255 cases and to demonstrate most common knee joint pathologies in our region.In our study knee joints of 255 cases who admitted to different clinics of our hospital with various complains of knee between October 1996 and December 1998 were examined in wide spectrum with MRI. Via 1.0 Tesla MRI device and special knee coil in sagittal, coronal and axial plains MRI images were obtained. The number of male and female patients were 173 and 82 and their ages were ranged between 14 and 70, and the mean age was 3413.The most common knee pathologies were intra-articular fluid (%58.04), medial (%46,66) and lateral (%12.55) meniscal injuries, anterior cruciate ligament injury (%17.25) and osteoarthritis (%14.9). The other important lesions were degeneration of medial and lateral meniscus, Baker’s cyst, bursitis, posterior cruciate ligament injury , medial and lateral collateral ligament injuries, synovial hypertrophy, chondromalasia of patella, and contusion.In our images of knee the most common lesions were injuries of meniscus and ligament. Because of being noninvasive technique for knee joint pathologies, capacity of multiplanar imaging, high contrast resolution and chance of detailed anatomic evaluation MR imaging was found to be most appropriate imaging technique for knee joint pathologies

Znieczulenie do cięcia cesarskiego u rodzących z łożyskiem przodującym z/bez łożyska wrośniętego – badanie retrospektywne

Objectives: The aim of this retrospective study was to review placenta previa cases and determine the prognostic factors effective on morbidity and mortality and to evaluate the strategy of anesthetic management. Material and methods: 65 women with placenta previa scheduled for elective or emergency cesarean sections from 2004 to 2009 were examined. Patient demographic data, surgery and obstetric characteristics, anesthetic techniques, blood transfusions, the values of hemoglobin and complications were recorded. Results: Mostly, general anesthesia was preferred in the parturients with placenta previa (86.2%, 56/65). 9 patients (13.8%), 2 of whom were converted to general anesthesia due to bleeding and prolonged surgery, received regional anesthesia. 37 of 65 women (56.9%) with placenta previa had had cesarean sections previously. More than half of these patients (21/37, 56.7%) had abnormally invasive placentation and 16 of 21 cases underwent cesarean hysterectomy. The incidence of complications in women with previous cesarean section with abnormally invasive placentation was higher than in the other women (pCel pracy: Celem tego retrospektywnego badania była analiza przypadków łożyska przodującego pod kątem oceny czynników prognostycznych wpływających na zachorowalność i śmiertelność oraz ocena postępowania anestezjologicznego. Materiał: Przeanalizowano 65 przypadków kobiet z łożyskiem przodującym zakwalifikowanych do elektywnego lub pilnego cięcia cesarskiego w latach 2004-2009.Zebrano następujące dane: demograficzne, wywiad operacyjny i położniczy, techniki anestezjologiczne, transfuzje krwi, poziomy hemoglobiny i powikłania. Wyniki: Preferowaną metodą znieczulenia u rodzących z łożyskiem przodującym było znieczulenie ogólne (86,2%; 56/65). Przewodowe znieczulenie otrzymało 9 pacjentek (13,8%) ale u 2 z nich trzeba było przejść na znieczulenie ogólne z uwagi na krwawienie i przedłużony czas operacji. 37 z 65 kobiet (56,9%) z łożyskiem przodującym miało cięcie cesarskie w poprzedniej ciąży. Więcej niż połowa tych pacjentek (21/37, 56,7%) miała nieprawidłowo utworzone łożysko a 16 z 21 przeszło histerektomię położniczą. Częstość powikłań u kobiet po cięciu cesarskim w wywiadzie i z nieprawidłowo utworzonym łożyskiem w analizowanym materiale była wyższa niż u innych pacjentek (

Is there a relationship between age and side dominance of tubal ectopic pregnancies? – A preliminary report

Objectives: To determine whether there exists a relationship between age and side dominance of tubal ectopic pregnancies. Material and Methods: One hundred twenty patients were retrospectively analyzed. The sides of the tubal ectopic pregnancies were recorded on the basis of laparoscopy or laparotomy findings. Five age groups were created: 20-24, 25-29, 30-34, 35-39, and ≥40 years. Results: Of the patients who were ≥ 30 years of age, 46 (69%) and 21 (31%) had tubal ectopic pregnancies on the right and left sides, respectively (p=0.002). In the 35-39 years of age group, 17 of 20 patients (85%) had tubal ectopic pregnancies on the right, and 3 of 20 patients (15%) on the left side (p=0.002). In the 30-34 years of age group, 26 of 39 patients (67%) and 13 of 39 patients (33%) had tubal ectopic pregnancies on the right and left sides, respectively (p=0.037). In the ≥ 40 years of age group, 3 of 8 patients (37%) had tubal ectopic pregnancy on the right side, while 5 patients (63%) on the left side (p=0.48). Conclusions: Patients who are between the age of 30-40 years have a right-sided dominance of tubal ectopic pregnancy, however studies that involve larger numbers of subjects are needed to make definitive conclusions about women older than 40 years of age

Ocena łożyska całkowicie przodującego przy pomocy rezonansu magnetycznego i ultrasonografii w celu wykrycia łożyska wrośniętego i jego wariantów

Objective: To evaluate the importance of ultrasonography (US) and magnetic resonance imaging (MRI) in detecting placental adherence defects. Material and methods: Patients diagnozed with total placenta previa (n=40) in whom hysterectomy was performed due to placental adherence defects (n=20) or in whom the placenta detached spontaneously after a Cesarean delivery (n=20) were included into the study between June 2008 and January 2011, at the Department of Obstetrics and Gynecology, Ege University (Izmir, Turkey). Gray-scale US was used to check for any placental lacunae, sub-placental sonolucent spaces or a placental mass invading the vesicouterine plane and bladder. Intra-placental lacunar turbulent blood flow and an increase in vascularization in the vesicouterine plane were evaluated with color Doppler mode. Subsequently, all patients had MRI and the results were compared with the histopathologic examinations. Results: The sensitivity of MRI for diagnosis of placental adherence defects before the operation was 95%, with a specificity of 95%. In the presence of at least one diagnostic criterion, the sensitivity and specificity of US were 87.5% and 100% respectively, while the sensitivity of color Doppler US was 62.5% with a specificity of 100%. Conclusions: Currently, MRI appears to be the gold standard for the diagnosis of placenta accreta. None of the ultrasonographic criteria is solely sufficient to diagnose placental adherence defects, however, they assist in the diagnostic process.Cel pracy: Celem pracy była ocena przydatności ultrasonografii (US) i rezonansu magnetycznego (MRI) w wykrywaniu nieprawidłowości implantacji łożyska. Materiał i metoda: Do badania włączono pacjentki, które leczone były w Klinice Położnictwa i Ginekologii na Uniwersytecie Ege w Izmirze (Turcja), w okresie od czerwca 2008 do stycznia 2011, z powodu łożyska całkowicie przodującego (n=40). U 20 pacjentek wykonano histerektomię z powodu trudności w oddzieleniu łożyska a u 20 łożysko oddzieliło się samoistnie w trakcie cięcia cesarskiego. Zastosowano skalę Graya do oceny lakun w łożysku, wolnych przestrzeni pod płytą łożyska oraz masy łożyskowej naciekającej płaszczyznę pęcherzowo-maciczną oraz pęcherz moczowy. W badaniu USG z kolorowym Dopplerem oceniano turbulentny przepływ krwi w lakunach wewnątrzłożyskowych oraz wzrost unaczynienia w płaszczyźnie pęcherzowo-macicznej. Następnie wszystkie pacjentki miały wykonane badanie MRI a wyniki porównano z oceną histopatologiczną. Wyniki: Czułość badania MRI dla rozpoznania nieprawidłowości implantacji łożyska przed operacją wyniosła 95% a specyficzność również 95%. Przy obecnym przynajmniej jednym kryterium diagnostycznym, czułość i specyficzność badania USG wyniosły odpowiednio 87,5% i 100%, podczas gdy czułość kolorowego Dopplera wyniosła 62,5% a specyficzność 100%. Wnioski: Obecnie badanie MRI jest złotym standardem wykrywania łożyska wrośniętego. Żadne z ultrasonograficznych kryteriów nie jest wystarczające do rozpoznania nieprawidłowości implantacji łożyska, aczkolwiek pełnią funkcję pomocniczą w procesie diagnostycznym

Nonlinear system identification using deterministic multilevel sequences

Bu &ccedil;alışmada sınırlı doğrusalsızlık derecesine sahip Volterra s&uuml;zge&ccedil;leri i&ccedil;in yeni bir g&ouml;sterilim geliştirilmektedir. Bu g&ouml;sterilim kullanılarak Volterra s&uuml;zge&ccedil;leri i&ccedil;in kesin bir tanılama y&ouml;ntemi sunulmaktadır. Bu yeni y&ouml;ntem, giriş işareti olarak farklı seviyelere sahip impulslardan oluşan gerekirci diziler kullanmaktadır. Yeni tanılama y&ouml;ntemi doğrusal, zamanla-değişmez sistemlerdeki birim impuls cevabının doğrusal olmayan sistemlere başarılı bir uyarlaması olarak d&uuml;ş&uuml;n&uuml;lebilir. &Ccedil;alışmada sunulan tanılama y&ouml;ntemi kesindir; b&ouml;ylece g&ouml;zlem g&uuml;r&uuml;lt&uuml;s&uuml; olmadığında Volterra &ccedil;ekirdeklerini hatasız kestirmektedir. Bilgisayar benzetimleriyle tanılama y&ouml;nteminin literat&uuml;rde yakın zamanda sunulmuş olan y&ouml;ntemlerden daha iyi kestirim sonu&ccedil;ları verdiği g&ouml;sterilmiştir.Anahtar Kelimeler: Doğrusal olmayan sistem tanılama, Volterra s&uuml;zge&ccedil;leri.In this paper we develop a new representation for the finite-order Volterra filters. This representation introduces a novel partitioning of the Volterra kernels.Using this representation, we formulate a novel exact identification method for Volterra filters, which uses deterministic sequences consisting of impulses with distinct levels. The identification method might be considered as a successful extension of the impulse response of the linear, time-invariant systems to the realm of nonlinear systems. The developed method indeed includes identification using the unit impulse response as a subcase when the system under consideration is a linear system. Our identification method is exact; hence, it calculates the exact Volterra kernels in the absence of noise for very short length input sequences. Our method calculates each Volterra kernel individually. The kernel estimates are not utilized in the calculation of further kernel estimates. This property hinders error propagation among kernel estimates. Our method calculates directly the Volterra kernels, instead of calculating first some intermediary representation such as the Wiener kernels, which do not have any directly interpretable results. Our method does not introduce and identify any kernels which are redundant for the regular Volterra filter. We demonstrate with simulations that the identification algorithm can produce better parameter estimates than some most recent algorithms in the literature. Keywords: Nonlinear system identification, Volterra filters

Kombinacja wewnątrzczaszkowej przezierności i ultrasonografii 3D w diagnostyce wad cewy nerwowej w pierwszym trymestrze ciąży: opis przypadku i przegląd literatury

Neural tube defects are congenital defects of the central nervous system caused by lack of neural tube closure. First trimester screening for aneuploidy has become widespread in the recent years. Fetal intracranial translucency (IT) can be easily observed in normal fetuses in the mid-sagittal plane. The absence of IT should be an important factor taken into consideration in the early diagnosis of open spinal defects. 3D ultrasonography is especially useful in cases of spinal anomalies where the visualization of the fetal structure is insufficient due to fetal position. We present a combination of intracranial translucency and 3D sonography used in the first trimester diagnosis of a neural tube defect case.Wady cewy nerwowej są wrodzonymi defektami centralnego układu nerwowego spowodowanymi brakiem zamknięcia cewy nerwowej. Badania skriningowe w pierwszym trymestrze w kierunku aneuploidii stały się w ostatnich latach bardzo rozpowszechnione. Płodowa przezierność wewnątrzczaszkowa może być oceniona w prawidłowych płodach w płaszczyźnie pośrodkowej. Brak przezierności wewnątrzczaszkowej (IT) powinien być istotnym czynnikiem ryzyka branym pod uwagę we wczesnej diagnostyce otwartych wad cewy nerwowej. Ultrasonografia 3D jest szczególnie przydatna w przypadkach gdy uwidocznienie struktur płodu jest niewystarczające z uwagi na pozycję płodu. Przedstawiamy kombinację przezierności wewnątrzczaszkowej i ultrasonografii 3D w diagnostyce wad cewy nerwowej w pierwszym trymetrze ciąży

KLASİK RTK ve AĞ-RTK YÖNTEMLERİNİN KARŞILAŞTIRILMASI

Günümüzde nokta konumlarının belirlenmesinde GNSS yaygın olarak kullanılmaktadır. Bu teknolojinin yoğun kullanımı, yüksek doğruluk ve duyarlıklı olarak gerçek zamanlı konum belirleme ihtiyacını doğurmuş ve bunun sonucu olarak öncelikle Standart (Klasik)- RTK (Real Time Kinematic) tekniği, ardından da Ağ-RTK (Network RTK) tekniği geliştirilmiştir. Günümüzde birçok ülkede sürekli gözlem yapan sabit GNSS istasyonları (CORS - Continuously Operating Reference Station) bulunmaktadır. Ülkemizde de Mayıs 2009’da faaliyete geçen, 146 istasyondan oluşan (KKTC (Kuzey Kıbrıs Türk Cumhuriyeti)’de 4 adet dahil) ve tüm ülkeyi kapsayan TUSAGA-Aktif (CORS-TR) istasyonları bulunmaktadır.Bu çalışmada, Klasik RTK yöntemiyle sabit istasyona olan uzaklıklar 1-10 km.arasında oluşturulan otuzar noktalı 10 bölgede, hem GPS hem de GPS+GLONASS uyduları kullanılarak nokta konumları belirlenmiştir. Elde edilen koordinatlar her bölgede yapılan ölçüler sonucu elde edilen Ağ-RTK koordinatlarıyla ve bölge ayrımı yapılmaksızın tüm noktaların koordinatları bir bütün olarak karşılaştırılmıştır. Bu karşılaştırma ile Klasik RTK yönteminde gezici alıcının sabit(referans) istasyonuna olan uzaklığının konum doğruluğuna etkisi araştırılmıştır. Yapılan değerlendirmeler neticesinde, konum doğruluğunu referans noktasına olan uzaklığın ve çevredeki engellerin (bina, hava alanı ve üstgeçit vb.) etkilediği görülmüştür.Test alanında yapılan ölçülerin değerlendirilmesi sonucu Ağ RTK ve Klasik RTK koordinatları arasındaki x ve y yönündeki farklar 0.2 cm. – 9.0 cm., ortalama hatalar ±1.28 cm. - ±4.39 cm, z yönündeki farklar ise 0.1 cm. – 15.7 cm., ortalama hatalar ise ±2.21 cm. - ±7.81 cm. arasında değişmektedir.