Polimer Katkılı Kompozitlerin Mekanik ve Yalıtım Özelliklerinin İncelenmesi

Enerji kaynaklarının sınırlı miktarda kalması, enerji üretimine göre enerji sarfiyatının daha yüksek olması ve insanların yaşam standartlarının iyileştirilmesi gibi nedenlerle yapıların yalıtımı ve yeni yalıtım malzemelerinin üretilmesi önem arz etmektedir. Ülkemizde, yalıtım özelliği bulunan bazı atık malzemeler amacına uygun değerlendirilmemekte ve çevre kirliliğine neden olmaktadır. Bu sebeple yalıtım, enerji tasarrufu açısından büyük öneme sahiptir. Enerji kaybı yalıtım teknolojileri ile azaltılabilir. Bu çalışmada, uçucu kül, PVC atığı, odun talaşı, meşe kabuğu ve pomza gibi malzemelerin beton üretiminde değerlendirilmesi ile ucuz, kaliteli yalıtım malzemesi üretilmesi ve bu malzemelerin inşaat sektörüne kazandırılması amaçlanmıştır. Bitüm ve çimento bağlayıcı faz olarak; uçucu kül, PVC atıkları, talaş ve meşe kabuğu ise agrega olarak kullanılmıştır. Üretilmiş olan 12 adet karışımdan ilk 4 tanesinin bağlayıcı malzemesi bitüm, kalan 8 tanesinin bağlayıcı malzemesi ise çimento olarak belirlenmiştir. Üretilen kompozitler üzerinde ultrases hızı, ısı geçirgenlik ve basınç dayanımı testleri uygulanmıştır. Isı geçirgenliği deneyinde en iyi sonuçlar %27 oranlarında çimento, su, pomza ve %19 oranında talaş içeren K5 numunesinden elde edilmiştir. Ayrıca, ultrases hızı deneyinde en iyi sonuçlar %12 PVC atık, %12 uçucu kül, %12 pomza, %12 talaş içeren K8 numunesinde 230 m/s olarak elde edilmiştir. Maksimum basınç dayanımı da K8 numunesinden 4 MPa olarak elde edilmiştir. Yapılan deneysel çalışmalar sonucunda üretilen yeni kompozitlerin ısı ve ses iletimi testlerinde önemli bir iyileşme elde edilmiş ve bu malzemelerin yalıtım teknolojisinde kullanılabileceği ortaya çıkarılmıştır

Evaluation of Transverse Acetabular Ligament Assessment due to Acetabular Labral Tear in Patients Undergoing Magnetic Resonance Arthrography

Objective:In this study, we investigated the relationship between labral tear with its stage and transverse acetabular ligament (TAL) morphology in patients who underwent magnetic resonance arthrography (MRA) examination for acetabular labral tear.Method:Radiological images of 55 patients who applied to our hospital with MRA for acetabular labral pathology were evaluated. Labral lesions were classified as post-traumatic (1A, 2A and 3A) and dysplastic (1B, 2B and 3B) according to the Czerny staging system. The widest contact surface and TAL area with the TAL femoral head were measured in MRAs of patients. In the statistical analysis, the widest contact surface of TAL with the femoral head and TAL area were compared to the right and left sides and according to the Czerny classification.Results:When labral pathologies were evaluated according to the Czerny classification, the widest contact surface of TAL with the femoral head and TAL area, left and right sides, and double groups (1-2,1-3,2-3) in Czerny 1-2-3 classification were compared as post-traumatic (1A, 2A and 3A) and dysplastic (1B, 2B and 3B) lesions of the labrum. As a result, no statistically significant difference was observed (p>0.05).Conclusion:There was no significant relationship between the staging of acetabular labral pathologies and TAL morphology, suggesting that TAL cannot be shown as a predisposing factor in terms of acetabular labral tear

Polimer Katkılı Kompozitlerin Mekanik ve Yalıtım Özelliklerinin İncelenmesi

Enerji kaynaklarının sınırlı miktarda kalması, enerji üretimine göre enerji sarfiyatının daha yüksek olması ve insanların yaşam standartlarının iyileştirilmesi gibi nedenlerle yapıların yalıtımı ve yeni yalıtım malzemelerinin üretilmesi önem arz etmektedir. Ülkemizde, yalıtım özelliği bulunan bazı atık malzemeler amacına uygun değerlendirilmemekte ve çevre kirliliğine neden olmaktadır. Bu sebeple yalıtım, enerji tasarrufu açısından büyük öneme sahiptir. Enerji kaybı yalıtım teknolojileri ile azaltılabilir. Bu çalışmada, uçucu kül, PVC atığı, odun talaşı, meşe kabuğu ve pomza gibi malzemelerin beton üretiminde değerlendirilmesi ile ucuz, kaliteli yalıtım malzemesi üretilmesi ve bu malzemelerin inşaat sektörüne kazandırılması amaçlanmıştır. Bitüm ve çimento bağlayıcı faz olarak; uçucu kül, PVC atıkları, talaş ve meşe kabuğu ise agrega olarak kullanılmıştır. Üretilmiş olan 12 adet karışımdan ilk 4 tanesinin bağlayıcı malzemesi bitüm, kalan 8 tanesinin bağlayıcı malzemesi ise çimento olarak belirlenmiştir. Üretilen kompozitler üzerinde ultrases hızı, ısı geçirgenlik ve basınç dayanımı testleri uygulanmıştır. Isı geçirgenliği deneyinde en iyi sonuçlar %27 oranlarında çimento, su, pomza ve %19 oranında talaş içeren K5 numunesinden elde edilmiştir. Ayrıca, ultrases hızı deneyinde en iyi sonuçlar %12 PVC atık, %12 uçucu kül, %12 pomza, %12 talaş içeren K8 numunesinde 230 m/s olarak elde edilmiştir. Maksimum basınç dayanımı da K8 numunesinden 4 MPa olarak elde edilmiştir. Yapılan deneysel çalışmalar sonucunda üretilen yeni kompozitlerin ısı ve ses iletimi testlerinde önemli bir iyileşme elde edilmiş ve bu malzemelerin yalıtım teknolojisinde kullanılabileceği ortaya çıkarılmıştır

Spinal melorheostosis: A rare presentation

CASE: A 22-year-old female patient was referred to the orthopaedic department for further examination after a radiopaque area was observed in the T6 vertebra in her chest radiograph. Computed Tomography (CT) showed a sclerotic mass with smooth borders, involving the entire body of the T6 vertebra, left posterior elements, posterior of the rib past the left zygapophyseal joint, and a "flowing candle wax" image toward the T7 vertebra. Spinal melorheostosis was considered radiologically in the patient, but malignancy could not be completely excluded. Thereupon, open biopsy was performed under general anesthesia. CONCLUSION: Spinal melorheostosis is a rare condition. Histological examination should be considered in cases where the diagnosis remains suspicious after clinical and radiological evaluations

A rare complication of the thyroid malignancies : jugular vein invasion

BACKGROUND: Unilateral invasion of the internal jugular vein (IJV) after subtotal thyroidectomy caused by local recurrence of papillary thyroid carcinoma is extremely rare. We report a case of papillary thyroid carcinoma which invades IJV with hypervascular tumor thrombus. CASE REPORT: We report a case of a 52-year-old woman with a history of previous thyroid operation who presented with a 2-month history of a painless, growing, hard, solitary mass on the left side of the neck. Clinical examination revealed also ipsilateral cervical lymphadenopathy. Radiological examination showed a necrotic and cystic mass arising from the operated area extending and invading the left jugular vein wall with hypervascular tumor thrombus. Cytological examination of the mass confirmed a papillary thyroid carcinoma (PTC) and enlarged metastatic lymph nodes. Therefore, total thyroidectomy with left neck dissection and segmental resection of the left internal jugular vein were performed, and the tumor thrombus was cleared successfully. CONCLUSIONS: Invasion of IJV with hypervascular tumor thrombosis is an extremely rare condition in papillary thyroid carcinoma. Thrombosis of IJV is probably underdiagnosed. Early-stage diagnosis is important for long-term survival rates

Increased prevalence of mild myopathic changes in the post-COVID-19 duration

There are reports of peripheral nerve and muscle involvement during or after coronavirus disease 2019 (COVID-19), even following a mild infection. Here, we aimed to analyze the objective findings regarding peripheral nerve, neuromuscular junction, and muscle function using electrophysiology in patients with a previous COVID-19 infection. All consecutive patients with a history of COVID-19 were questioned for post-COVID-19 duration-related neurological complaints via Composite Autonomic Symptom Score-31 (COMPASS-31), modified Toronto Neuropathy score (mTORONTO), and Fatigue Severity Scale (FSS). Patients were dichotomized into two groups based on their scores in the questionnaire. Group 1 (patients with high scores in any area of the questionnaire) and Group 2 (patients with normal scores in all sections of the questionnaire). In the second step, Group 1 was invited to a preplanned hospital visit for electrophysiological analysis, including nerve conduction studies, repetitive nerve stimulation, needle electromyography (EMG), quantitative motor unit potential analysis (qMUP), and single fiber EMG. We included 106 patients in the study. According to the questionnaire, 38 patients constituted Group 1, and 68 formed Group 2. Of the 38 patients, 14 accepted and underwent preplanned electrophysiological examinations. Needle EMG revealed small, short, polyphasic MUPs with early recruitment, and qMUP analysis demonstrated an increased percentage of polyphasic potentials in three patients. The examinations in other patients were unremarkable. The high prevalence of complaints and objective myopathic findings in our cohort implicated the role of muscle involvement in the post-COVID-19 duration. Considering the socioeconomic and psychological burden of the post-COVID-19 duration among individuals and societies, a better understanding of the symptoms and myopathy is warranted.</p

Evaluation of abdominal computed tomography findings in patients with COVID-19: a multicenter study

PURPOSE: To evaluate the frequency of abdominal computed tomography (CT) findings in patients with coronavirus disease-2019 (COVID-19) and interrogate the relationship between abdominal CT findings and patient demographic features, clinical findings, and laboratory test results as well as the CT atherosclerosis score in the abdominal aorta. METHODS: This study was designed as a multicenter retrospective study. The abdominal CT findings of 1.181 patients with positive abdominal symptoms from 26 tertiary medical centers with a positive polymerase chain-reaction test for severe acute respiratory syndrome coronavirus 2 were reviewed. The frequency of ischemic and non-ischemic CT findings as well as the association between CT findings, clinical features, and abdominal aortic calcific atherosclerosis score (AA-CAS) were recorded. RESULTS: Ischemic and non-ischemic abdominal CT findings were detected in 240 (20.3%) and 328 (27.7%) patients, respectively. In 147 patients (12.4%), intra-abdominal malignancy was present. The most frequent ischemic abdominal CT findings were bowel wall thickening (n = 120; 10.2%) and perivascular infiltration (n = 40; 3.4%). As for non-ischemic findings, colitis (n = 91; 7.7%) and small bowel inflammation (n = 73; 6.2%) constituted the most frequent disease processes. The duration of hospital stay was found to be higher in patients with abdominal CT findings than in patients without any positive findings (13.8 ± 13 vs. 10.4 ± 12.8 days, P 0.001). The frequency of abdominal CT findings was significantly higher in patients who did not survive the infection than in patients who were discharged after recovery (41.7% vs. 27.4%, P 0.001). Increased AA-CAS was found to be associated with a higher risk of ischemic conditions in abdominal CT examinations. CONCLUSION: Abdominal symptoms in patients with COVID-19 are usually associated with positive CT findings. The presence of ischemic findings on CT correlates with poor COVID-19 outcomes. A high AA-CAS is associated with abdominal ischemic findings in patients with COVID-19