Bitkisel bir kompozitin yüzey topografyası basılabilirliğini nasıl etkiler?

In this study, the effect of surface topography of luffa fiber reinforced green composite materials on its printability was investigated. For this purpose, bio-composite plates using luffa fiber as reinforcement and epoxy as the matrix were produced. Then, printing such as line and dot on the surfaces of these plates was carried out by the screen printing method. Before and after printing, the surface roughness values of the produced bio-composites were measured using 3D non-contact optical profilometer. Afterward, to validate these measurements and to check the printing quality, 3D Optical Profilometer was used to scan the surface roughness of bio-composite materials. According to the obtained results, the improvement of the composite surface topography is increase surface smoothness. With this result, it is clearly understood that the surface smoothness is the main parameter of printability for the resulting image clarity.Bu çalışmada, kabak lifi takviyeli bitkisel kompozit malzemelerin yüzey topografyasının basılabilirliğine etkisi incelenmiştir. Bu amaçla, takviye olarak kabak lifi ve matris olarak epoksi kullanılarak biyokompozit plakalar üretilmiştir. Daha sonra bu plakaların yüzeylerine çizgi ve nokta gibi baskılar serigrafi baskı yöntemi ile gerçekleştirilmiştir. Baskıdan önce ve sonra, üretilen biyo-kompozitlerin yüzey pürüzlülük değerleri, 3D temassız optik profilometre kullanılarak ölçülmüştür. Daha sonra bu ölçümleri doğrulamak ve baskı kalitesini kontrol etmek için 3D Optik Profilometre biyo-kompozit malzemelerin yüzey pürüzlülüğünü taramak için kullanılmıştır. Elde edilen sonuçlara göre, kompozit yüzey topografyasındaki gelişme, yüzey pürüzsüzlüğünü arttırmaktadır. Bu sonuç ile yüzey pürüzsüzlüğünün, elde edilen görüntü netliği için basılabilirliğin ana parametresi olduğu açıkça anlaşılmaktadır

Hayat dolu kalbi 23.30'da durdu

Taha Toros Arşivi, Dosya No: 67-Barış MançoUnutma İstanbul projesi İstanbul Kalkınma Ajansı'nın 2016 yılı "Yenilikçi ve Yaratıcı İstanbul Mali Destek Programı" kapsamında desteklenmiştir. Proje No: TR10/16/YNY/010

Effects of structured exercise program on severity of dizziness, kinesiophobia, balance, fatigue, quality of sleep, activities of daily living, and quality of life in bilateral vestibular hypofunction

BACKGROUND: A minimal number of studies have documented the impact of Vestibular rehabilitation (VR) on the recovery rate of patients with bilateral vestibular hypofunction (BVH). OBJECTIVE: The purpose of this study was to investigate the effectiveness of structured VR programs on severity of dizziness, kinesiophobia, balance, fatigue, quality of sleep, activities of daily living (ADL) and quality of life (QoL) in subjects with chronic BVH. METHOD: Twenty-five participants diagnosed with BVH were included in the study. A structured VR program was applied in 50-minute sessions once a week and as a home exercise program 3 times a day over 8 weeks. Participants were evaluated for severity of dizziness with the visual analog scale, for kinesiophobia with the tampa scale of kinesiophobia, for balance with the Semitandem, tandem, and standing tests, for quality of sleep with the Pittsburgh sleep quality index, for ADL with the vestibular disorders activities of daily life, for QoL with dizziness handicap inventory and for fatigue with the fatigue severity scale at the baseline (T1), at 4th week (T2), 8th week (T3), and 20th week (T4) after study started. RESULTS: Significant difference in terms of Tandem Test and 1 Leg Stand Test was found in favor of T3-T4 Period (P < .05). There were significant improvements in terms of vestibular disorders activities of daily life, tampa scale of kinesiophobia, Pittsburgh sleep quality index and dizziness handicap inventory in favor of the T3 to T4 Period (P < .05). Significant difference in terms of visual analog scale was found in favor of T2 Period (P < .05). CONCLUSIONS: A twelve-week structured VR program may enhance severity of dizziness, kinesiophobia, balance, quality of sleep, ADL and QoL in participants with chronic BVH

Diagnostic Value of the Video Head Impulse Test in Patients with Vertigo: Can It Be Used as a Screening Tool?

Background and Aim: Several laboratory tools are used to evaluate balance disorders but, there is still no screening test to determine the site and the severity of the lesion. The aim was to investigate whether video Head Impulse Test (vHIT) can be used as a screening test in patients with chronic or recurrent vertigo and dizziness. Methods: The files of 965 patients who were followed up in our vertigo outpatient clinic were reviewed retrospectively. Vestibulo-Ocular Reflex (VOR) gains and saccadic movements of the right and left lateral canals in the vHIT test, and Canal Paresis (CP) in the Caloric Testing (CT) were noted. Results: A total of 325 patients were included in our study. In CT results, the group that CP was most frequently detected was Menière’s Disease (MD) group (71 patients (74.7%). While vHIT results were found to be pathological in the vast majority of patients in the Vestibular Neuritis (VN) group (72.7%), the results were found to be normal at the highest rate in the vestibular migraine group (77.9%). Correlation analysis showed a significant but weak correlation between the degree of CP in the CT and the VOR gains of the lateral canals in vHIT in all groups. Conclusion: Although it has high sensitivity in cases with VN and vestibulopathy, we think that vHIT cannot be used as a screening tool in patients with vertigo, especially for chronic cases, since its sensitivity rate differs in the long term according to the cause of the disease

A Child with Acute Appendicitis Secondary to Blunt Abdominal Trauma: A Case Report and Review of the Literature

We present a child with abdominal pain and vomiting after blunt abdominal trauma (BAT). He had tenderness, guarding and rebound on the bilateral lower quadrant of the abdomen. He had no abrasion on the abdominal skin surface. He had marked leukocytosis and increased C-reactive protein level. Contrast-enhanced abdominal computed tomography revealed inflamed appendicitis. He was operated by pediatric surgeons and, an perforated appendix was illustrated on pathological examination. BAT and acute appendicitis (AA) are independently very frequent issues. In pediatric emergency departments, BAT and AA are very frequent issues, however, coexistence of these two condition in the same patient is rare. This case report and review of the literature showed that occurrence of AA after BAT should be considered by emergency physicians

Idiopathic pulmonary hemosiderosis mimicking iron deficiency anemia: a delayed diagnosis?

Idiopathic pulmonary hemosiderosis (IPH) is an uncommon chronic disorder in children. It is characterized by recurrent pulmonary hemorrhage and may result in hemoptysis and pulmonary insufficiency. The most common hematologic manifestation of IPH is iron deficiency anemia. The etiology of IPH is not known and its diagnosis may be difficult due to the variable clinical courses. The most helpful signs for identifying IPH are iron deficiency anemia and recurrent or chronic cough, hemoptysis, dyspnea, wheezing. We report here 5 pediatric cases of IPH presenting with iron deficiency anemia and without pulmonary symptoms. Mean corpuscular volume was low in all patients; iron was low in 4 out of 5 cases; total iron binding capacity was high in all of them; ferritin was low in 3 patients. At follow up, none of them had responded successfully to the iron therapy. Although they didn’t present with pulmonary symptoms, chest radiographs incidentally revealed diffuse reticulonoduler shadows in all of them. Computed tomography revealed diffuse ground-glass opacities, consolidation, increased density. The diagnosis was confirmed by the detection of hemosiderinladen macrophages in bronchoalveolar lavage fluid and gastric aspirate. If patients with iron deficiency anemia don’t respond to iron therapy, they should be examined for IPH. Chest radiographs should be taken even in absence of pulmonary symptoms. Early diagnosis is important for a timely management of IPH

The genetic history of the Southern Arc: a bridge between West Asia and Europe

By sequencing 727 ancient individuals from the Southern Arc (Anatolia and its neighbors in Southeastern Europe and West Asia) over 10,000 years, we contextualize its Chalcolithic period and Bronze Age (about 5000 to 1000 BCE), when extensive gene flow entangled it with the Eurasian steppe. Two streams of migration transmitted Caucasus and Anatolian/Levantine ancestry northward, and the Yamnaya pastoralists, formed on the steppe, then spread southward into the Balkans and across the Caucasus into Armenia, where they left numerous patrilineal descendants. Anatolia was transformed by intra–West Asian gene flow, with negligible impact of the later Yamnaya migrations. This contrasts with all other regions where Indo-European languages were spoken, suggesting that the homeland of the Indo-Anatolian language family was in West Asia, with only secondary dispersals of non-Anatolian Indo-Europeans from the steppe

Using radiologic criteria; is it possible to differentiate malignancy in solid pancreas tumors?

Pankreas kanseri, erkekerlerde dördüncü, kadınlarda ise beşinci sırada gelen kanserden ölüm nedenidir. Klinik muayene ve biyokimyasal yöntemlerle tanısının konulamaması, cerrahi olarak zor bir yerleşimde olması nedeniyle radyolojik görüntüleme yöntemleri tanıda, tedavi yönteminin belirlenmesinde ve tedavi takibinde önemlidir. Kronik pankreatit, pankreasın ekzokrin fonksiyonlarında azalmaya neden olan histopatolojik olarak fibrozis ile karakterize kronik enfeksiyondur. En sık nedeni alkol kullanımıdır. Tekrarlayan akut pankreatit atakları sonucunda geliştiği düşünülmektedir. Otoimmün pankreatit nadir görülen, otoimmün etyolojinin neden olduğu pankreasın kronik yangısal hastalığıdır. Tüberküloz pankreatit ise genellikle milier tüberkülozlu olgularda peripankreatik lenf nodu tutulumuna bağlı olarak ortaya çıkan bir hastalıktır.Yukarıda tanımlanmış olan benign ve malign hastalıkların klinik ve muayene bulguları benzerdir. Ancak bu hastalıkların sağaltımı tamamen farklıdır. Radyolojik görüntüleme yöntemleriyle pankreasın benign ve malign hastlalıklarında tanımlanmış olan bulguların her iki klinik durumda da gözlenenbilmesi nedeniyle ayırıcı tanıda güçlük yaşanmaktadır. Çalışmadaki amacımız radyolojik kriterlerin iki lezyon grubunu ayırmadaki etkinliğini irdelemektir.Gereç ve Yöntem Çalışmamızda Dokuz Eylül Üniversitesi Tıp Fakültesi Radyoloji Anabililm Dalı'nda 2003-2011 yılları arasında abdominal BT veya MR incelemesi yapılan ve pankreasında fokal kitlesel lezyon tanımlanmış olgular retrospektif olarak aynı deneyimde iki radyolog tarafından değerlendirilmiştir. Çalışmaya 58 malign, 26 benign tanılı olgu dahil edilmiştir. Çalışmaya dahil edilen olgularda kitlesel lezyonun sınır netliği, lezyonun iç yapısı, lezyonda kalsifikasyon bulunması, normal panreas parankiminde kalsifikasyon bulunması, pankreas kanalında dilatasyon varlığı ve dilatasyon tipi, peripankreatik yağlı doku heterojenitesi, peripankreatik alanda lenf nodu varlığı, lezyonun pankreas parankimine göre arterial ve portal fazda kontrastlanma düzeyleri kriterleri teker teker değerlendirilmiştir. Ayrıca bu kriterlerin ikişerli, üçerli, dörderli gruplandırılması yapılarak lezyon karekterizasyonunda duyarlılık ve özgüllük değerleri yükseltilmeye çalışılmıştır. BulgularBelirlenmiş olan kriterlerden sadece peripankreatik alan heterojenitesinin lezyon karekterizasyonunda istatistiksel olarak anlamlı olmadığı saptanmıştır. Diğer kriterlerden herbiri istatistiksel olarak anlamlı bulunmuştur. Lezyonda kalsifikasyon olmaması %91.3, parankimde kalsifikasyon olmaması %100 değerleri ile tek başına en yüksek duyarlılık değerine sahip idi. Lezyon karakterizasyonunda tanımlanan kritelerden tek başına en yüksek seçicilik değerine sahip olanlar ise %80.7 ile damar invazyon varlığı ve %73 ile peripankreatik alanda lenf nodu varlığı idi. Kriterlerin gruplandırılımasıyla yapılan değerlendirmede kitlesel lezyonda kalsifikasyon bulunmayan, kitlesel lezyonda sınır netliği olan, kitlesi arterial fazda parankime göre az kontrastlanan ana pankreatik kanalda düzenli dilatasyona neden olma kriterlerine sahip olgularda seçicilik değeri %100 olarak saptanmıştır.Tartışma ve Sonuç Pankreasın malign ve benign lezyonlarının radyolojik yöntemler ile ayrılması sağaltımı farklı olan hastalıklara yaklaşımda son derece önemlidir. Ancak radyolojik olarak bu her zaman mümkün olmamaktadır. Elde ettiğimiz sonuçlarda benignitenin kuvvetli göstergesi olan parankimde veya lezyonda kalsifikasyon varlığı kronik pankreatitli olgularda gelişen pankreas kanseri ayrımında yeterince anlamlı olmayabilir. Çalışmamızda kritelerin gruplandırılmasıyla tatmin edici düzeyde seçicilik değerlerine ulaşılmıştır, ancak duyarlılık değerinin arttırılması yeni görüntüleme yöntemlerinin geliştirilmesine bağlıdır. İlk araştırma verileri bu konuda MR-difüzyon incelemesini öne çıkartmaktadır. Pancreas cancer is the fourth leading cause of cancer-related death in men, and fifth in women. Cancer of the pancreas may not be readily diagnosed by clinical examination and biochemical testing methods, moreover, localization of the tumor is surgically difficult. Therefore, radiographic imaging techniques are highly important in the diagnosis of pancreas cancer, also in determining and monitoring the treatment. Chronic pancreatitis is a chronic infection, histopathologically characterized by fibrosis, and resulting in reduction of the pancreatic exocrine functions. The most common cause is accepted as alcohol abuse. It is considered to develop more likely as a result of recurrent attacks of acute pancreatitis. Autoimmune pancreatitis is a rare chronic inflammatory disease of the pancreas caused by an autoimmune etiology. Tuberculosis pancreatitis is also rare and generally seen in miliary tuberculosis patients as a result of peripancreatic lymph node involvement. Clinical and physical examination findings of the benign and malignant diseases described above are more or less similar. However, relevant treatment approaches are completely different. In some instances, benign and malignant pancreatic diseases may not be differentiated by common clinical findings defined by radiographic imaging methods. The objective of this study is to examine thoroughly the effectiveness of radiological criteria in differentiating each lesion group. Material and Method In our study, patients who have been examined by abdominal CT scan or MRI and diagnosed as pancreas cancer with the defined focal mass lesions in the period between 2003-2011, by the Department of Radiology, Faculty of Medicine, Dokuz Eylul University, were retrospectively evaluated by two different radiologists. Totally 58 malignant and 26 benign cases were enrolled in the study. For each of the participants, criteria such as clearness of the margins of the tumor mass, internal structure of the lesion, presence of calcification in the lesion and in the normal pancreas parenchyma, presence of pancreatic duct dilatation and dilatation-type, peripancreatic fatty tissue heterogeneity, presence of peripancreatic lymph node, arterial and portal levels of enhancement according to pancreas parenchymal tissue were individually evaluated. In addition, these criteria were further grouped in pairs, threes, and fours in order to increase sensitivity and specificity values with regard to the lesion characterization. Results Among the specified criteria, presence of peripancreatic heterogeneity was not found statistically significant, while each of the other criteria was determined as statistically significant. Lack of calcification both in the lesion and also in the pancreas parenchyma displayed highest sensitivity, with the values respectively, 91.3% and 100%. Highest specificity values were observed for vascular invasion and presence of peripancreatic lymph node, as 80.7% and 73%, respectively. In the evaluation performed by grouping the criteria, the specifity of the case lacking calcification in the lesion, prominent with clear mass margins, having less enhancement in the arterial phase compared to pancreas parenchyma, and causing regular dilatation in the main pancreatic duct, was determined as 100%.Discussion and Conclusion Differentiation of malignant and benign lesions of the pancreas by using radiological methods are significantly important in approaching to different diseases having different treatments. However, this may not always be possible by current radiological methods. According to the data we achieved, as a strong indication of benignity, presence of calcification in parenchyma or in the lesion may not be significant enough in differentiating cancer development in patients with chronic pancreatitis. We obtained satisfactory specificity values by grouping the criteria, but increasing sensitivity values may be dependent on the development of new imaging techniques. According to the preliminary study data, MR-diffusion technique has become prominent and distinguished in this sense

Comparing The Most Commonly Used Classical Methods For Determining The Ridge Parameter In Ridge Regression

Multicollinearity is a most common problem in multiple regression models. Many different methods are developed to solve the problem of multicollinearity. Ridge regression estimation is a popular one of these methods. And the mostly investigated matter of this method is determining the ridge parameter; therefore, various procedures are developed for determining the ridge parameter in ridge regression. In this study, we compared the commonly used methods for choosing the ridge parameter in an actual data set taken from General Directorate of Turkish Highways and Turkish Statistical Institute. We calculated the ridge parameter by the methods which are known as ridge trace, ordinary ridge estimator and an iterative method for ordinary ridge estimator. We indicated the good and worst aspects of these methods in terms of mean square error (MSE), variance inflation factors (VIF) and the other multicollinearity statistics. According the results of this study, we found that, the ridge trace method is more useful then others when it is evaluated together with the statistics of model

Sıçanlarda testis torsiyonu tanısında kullanılan Power Doppler Ultrason ve Renkli Doppler Ultrason tekniğinin Süperb Mikrovasküler Imaging Ultrason tekniği ile karşılaştırılması

Amaç: Testis torsiyonu cerrahi bir acildir. Bu çalışmada sıçanlarda testis torsiyonu tanısında Power Doppler Ultrason, Renkli Doppler Ultrason ve Superb Mikrovasküler Imaging Ultrason tekniklerinin birbirlerine üstünlüklerini değerlendirmeyi amaçlamaktadır. Gereç ve yöntem: 210-262 gr ağırlığında, 26-30 günlük, 30 pubertal Wistar-Albino erkek sıçanı deneye dahil edildi. Sıçanlar, grup A-sham, bir saatlik torsiyondan sonra grup B-orşiektomi, iki saatlik torsiyondan sonra grup D-orşiektomi, üç saatlik torsiyondan sonra grup C-orşiektomi, dört saat sonra grup C-orşiektomi grubu olmak üzere 5 gruba randomize olarak ayrıldı. Tüm sıçanlar torsiyondan önce Power Doppler Görüntüleme, Renkli Doppler Görüntüleme ve Süper Mikrovasküler Görüntüleme ile takip edildi, ancak torsiyonun birinci saatinden sonra B grubuna üç ultrason tekniği, torsiyonun birinci ve ikinci saatlerinden sonra grup C'ye üç ultrason tekniği ile, grup D torsiyonun birinci, ikinci ve üçüncü saatlerinden sonra her üç ultrason tekniği ile, grup E'ye ise torsiyonun birinci, ikinci, üçüncü ve dördüncü saatlerinden sonra her üç ultrason tekniği ile ultrason yapıldı. Tüm sıçanlara aynı doktor tarafından 7-18 MHz lineer prob kullanılarak ultrason taraması yapıldı. Görüntüler, damarlanma derecesi ve artefaktların varlığı açısından değerlendirildi. Her grubun torsiyon süresi sonunda orşiektomi yapılması ile histopatolojik değerlendirme yapıldı. Bulgular: Superb Mikrovasküler Imaging Ultrason, torsiyonlu testislerde Renkli Doppler Ultrason ve Power Doppler Ultrasona göre kıyasla istatistiksel olarak anlamlı bir fark olmaksızın daha yüksek evreleme puanlarına sahipti. 4 saatlik iskemiden sonra, her üç yönteme de aynı puanları verdi. Histopatolojik evrelemeye bakıldığında 1 saatlik iskemi ile 2, 3 ve 4 saatlik iskemi süreleri arasında anlamlı fark bulundu. 2, 3 ve 4 saatlik iskemiden sonra yapılan histopatolojik evrelemede anlamlı bir fark bulunmadı. Her üç cihazın da her saat için birbiriyle uyumlu olduğu görüldü. Sonuç: Testis torsiyonunu saptamak için kullanılan Superb Mikrovasküler Imaging Ultrason, Power Doppler Ultrason ve Renkli Doppler Ultrason ile karşılaştırılmasında her üç teknik de etkili ve güvenli tanı yöntemleri olarak bulundu