Spiro fosfozen molekülünün geometrik yapısının ve titreşim frekanslarının teorik olarak incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Temel halde bulunan spiro fosfozen'in titreşim frekansları ve geometrik yapısıHartree-Fock ve yoğunluk fonksiyonu metodu (B3LYP) ile 6-31G(d) temel setikullanılarak hesaplanmıştır. HF ve DFT (B3LYP) kullanılarak elde edilenoptimumlaştırılmış geometrik bağ uzunlukları ve bağ açıları deneysel verilerle iyi biruyumluluk göstermektedir. Hartree-Fock ve yoğunluk fonksiyonu metodu (B3LYP)ile hesaplanan sonuçlar, spiro fosfozen'in gözlenen temel titreşim frekansları ilekarşılaştırıldığında B3LYP moleküler titreşim problemleri için hesaplanan Hartree-Fock yaklaşımına göre daha üstündür.The molecular geometry and vibrational frequencies of spiro phosphazene in theground state have been calculeted using the Hartree-Fock and density functionalmethod (B3LYP) with 6-31(G)d basis set. The optimized geometric bomd lengthsand bond angles obtained by using HF and DFT (B3LYP) show the best agreementwith the experimental data. Comparison of the observed fundemental vibrationalfrequencies of Spiro phosphazene with calculated results by density functional(B3LYP) and Hartree-Fock methods indicate that B3LYP is superior to the scaledHartree-Fock approach for molecular vibrational problems

Outcomes of high-risk breast lesions diagnosed using image-guided core needle biopsy: results from a multicenter retrospective study

PURPOSEThe clinical management of high-risk lesions using image-guided biopsy is challenging. This study aimed to evaluate the rates at which such lesions were upgraded to malignancy and identify possible predictive factors for upgrading high-risk lesions.METHODSThis retrospective multicenter analysis included 1.343 patients diagnosed with high-risk lesions using an image-guided core needle or vacuum-assisted biopsy (VAB). Only patients managed using an excisional biopsy or with at least one year of documented radiological follow-up were included. For each, the Breast Imaging Reporting and Data System (BI-RADS) category, number of samples, needle thickness, and lesion size were correlated with malignancy upgrade rates in different histologic subtypes. Pearson’s chi-squared test, the Fisher–Freeman–Halton test, and Fisher’s exact test were used for the statistical analyses.RESULTSThe overall upgrade rate was 20.6%, with the highest rates in the subtypes of intraductal papilloma (IP) with atypia (44.7%; 55/123), followed by atypical ductal hyperplasia (ADH) (38.4%; 144/375), lobular neoplasia (LN) (12.7%; 7/55), papilloma without atypia (9.4%; 58/611), flat epithelial atypia (FEA) (8.7%; 10/114), and radial scars (RSs) (4.6%; 3/65). There was a significant relationship between the upgrade rate and BI-RADS category, number of samples, and lesion size Lesion size was the most predictive factor for an upgrade in all subtypes.CONCLUSIONADH and atypical IP showed considerable upgrade rates to malignancy, requiring surgical excision. The LN, IP without atypia, pure FEA, and RS subtypes showed lower malignancy rates when the BI-RADS category was lower and in smaller lesions that had been adequately sampled using VAB. After being discussed in a multidisciplinary meeting, these cases could be managed with follow-up instead of excision

Giant sacral schwannoma causing bilateral hydronephrosis: Case report and review of the literature

BACKGROUND: Giant sacral schwannomas are very rare, and less than 1%-5% of spinal schwannomas are found in the sacral region. These frequently grow to considerable size because of permissive anatomic location and benign, slow growth of tumor. They can be unnoticed before reaching a huge size.CASE DESCRIPTION: We report a rare case of a giant sacral schwannoma in a 46-year-old man. The patient presented with difficulty in passing urine, episodic constipation, and swelling of the right lower extremity for 6 months. Magnetic resonance imaging revealed 160 x 110 x 110 mm encapsulated heterogenous solid mass originated from left S1 spinal nerve extending into the pelvis and abdomen. Sigmoid colon and rectum were displaced to the right side, and bladder was displaced anteriorly. Left side of the S1 and S2 vertebral bodies, left S1 and S2 neural foramen were also eroded. It also compressed ureters causing bilateral hydronephrosis. The patient underwent a 2-stage procedure in which complete resection was achieved.CONCLUSIONS: We report the second case of a completely resected giant sacral schwannoma with bilateral hydronephrosis in the literature. Performing a 2-stage procedure is important in giant sacral schwannomas. Morbidity can be minimized, and extent of resection can be maximized with the help of combined anterior/posterior approach

Fırsat eşitliği açısından eğitimde dijitalleşme: Öğretmen görüşleri

<p><span>Bu araştırmanın amacı, fırsat eşitliği açısından eğitimde dijitalleşme konusunun öğretmen görüşlerine göre incelemektir. Bu araştırmada nitel yöntem tercih edilmiş olup olgu bilim deseninde tasarlanmıştır. Araştırmanın çalışma grubunu 21 öğretmen oluşturmuştur. Çalışma grubu, ölçüt örnekleme yaklaşımı ve maksimum çeşitlilik kullanılarak seçilmiştir. Veri toplama aracı olarak araştırmacının yarı yapılandırılmış görüşme formu kullanılmıştır. Görüşmeler, çalışma grubu üyeleriyle yüz yüze gerçekleştirilmiştir. Çalışma verileri temalar, kategoriler ve kodlar ortaya çıkarmıştır. Veriler üzerinde hem içerik analizi hem de betimsel analiz yapılmıştır. Araştırmada öğretmenlerin dijital eğitim materyallerine yönelik görüşleri, avantajlar ve dezavantajlar temaları altında toplanarak incelenmiştir. Dijital araçların öğrenci katılımı ve etkileşimi üzerindeki etkiler ise kullanma becerilerine ilişkin değişiklikler, öğrenme içeriğine ilişkin değişiklikler ve eşit katılım zorlukları teması altında ele alınmıştır. Öğrencilerin dijitalleşme sürecinde karşılaştığı engeller, okullardaki teknolojik altyapı eksikliği, sosyo-ekonomik sınırlamalar ve motivasyonel unsurlar olarak belirlenmiştir. Fırsat eşitliğini sağlamak için öğretmenlerin benimsediği stratejiler, bireysel yaklaşımlar ve eğitsel yaklaşımlar olarak iki temada özetlenmiştir.</span></p&gt

Wrist fractures: sensitivity of radiography, prevalence, and patterns in MDCT

© 2014, American Society of Emergency Radiology.The aims of this study are to evaluate diagnostic performance of conventional radiographs for wrist fractures using multidetector computerized tomography (MDCT) as a reference standard, to determine prevalence, demographic risk factors including age and sex, and associations among various wrist fractures. A retrospective study was performed, finding a total 455 patients (457 wrists) who had wrist trauma and who had undergone a radiography and subsequent MDCT examination during a 45-month period. The MDCT and radiographs of the patients were reviewed by two radiologists, and a consensus was obtained for the presence of fracture. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of radiographs were calculated using MDCT findings as reference standard. The correlation of both age and sex between the presence of fracture was also analyzed. Of the 455 patients, 223 (49.0 %) had one or more fractures in wrist. A total of 302 (160 patients had one, 50 had two, 10 had three, and 3 had four) fractures were diagnosed in the wrist region. In 457 wrists, MDCT revealed 128 occult fractures missed by radiography. The overall sensitivity, specificity, PPV, and NPV of radiography for the detection of all wrist fractures were 57.8, 99.5, 87.4, and 97.4 %, respectively. The sensitivities of radiography ranged 0–41.2 % for other carpal bone except scaphoid (66 %) fractures and 66.7–80 % for the proximal metacarpus, distal ulna, and radius fractures. Wrist fractures appear to be overlooked on radiography. Further imaging should be warranted for patients who are clinically suspicious for wrist fracture in emergency rooms

Visceral Leishmaniasis Caused by Leishmania Tropica

Purpose: In Turkey, the main causative agent of visceral leishmaniasis (VL) is Leishmania. infantum and the main causative agent of cutaneous leishmaniasis (CL) is Leishmania tropica. In this study, we aimed to discuss the possible mechanisms, clinical aspects, and threat of visceralizing L. tropica. Methods: This study includes seven cases of VL caused by L. tropica.Five patients were male (71%) and four were adults (57%). Results: All the VL patients complained of fever and splenomegaly. Fatigue, pancytopenia, and hepatomegaly were present in six patients each (86%), while weight loss and gastrointestinal system (GIS) symptoms were present in 5 patients (71%). Conclusions: In this study, we have evaluated seven cases of visceralized L. tropica (VLT) in the context of the changing leishmaniasis epidemiology in Turkey. We have evaluated the possible mechanisms of visceralization; inter- and intraspecies genetic exchange with all the old world leishmaniasis agents present in the region, stress induced by inappropriate use of drugs, and possible ongoing adaptation mechanisms of Leishmania spp. The threat posed by VLT is significant as L. tropica is the most widespread and most common cause of leishmaniasis in Turkey. We do not know the vectorial capacity of the sand flies for the transmission of VLT strains or if these strains are in circulation in Turkey. Future studies should be carried out to investigate these issues as the transition of L. tropica from a mild disease-causing agent to a mortal one poses a significant public health concern for Turkey and Europe