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Hakan Bıçakçı’nın Uyku Sersemi romanında uzamdaki dönüşümün birey üzerindeki etkileri nasıl anlatılmıştır

A new approach for measuring viscoelastic properties of soft materials using the dynamic response of a spherical object placed at the sample interface

Background: There are several techniques to characterize the mechanical properties of soft materials, such as the indentation method and the method based on the application of a spherical object placed inside the sample. The indentation systems usually yield the elastic properties of materials and their mathematical models do not consider the inertia of the sample involved in motion and radiation damping, while placing an object inside the sample is not practical and this procedure can alter the mechanical properties of the sample for the method based on the application of a bubble/sphere placed inside the sample. Objective: A new approach for the identification of the viscoelastic properties of soft materials using the dynamic response of a spherical object placed at the sample interface was proposed. Methods: The spherical object placed at the sample interface was pressed using an electromagnet and the dynamic response of the spherical object was tracked using a high-speed camera, while the dynamic response of the spherical object placed at the sample interface was estimated using a comprehensive analytical model. The effects of the shear modulus, viscosity, Poisson’s ratio and density of the soft sample, the radius and density of the spherical object and the damping due to radiation were considered in this mathematical model. The shear modulus and viscosity of the soft sample were determined by matching the experimentally identified and theoretically estimated responses of the spherical object. Results: The shear moduli and viscosities of the three phantoms with the gelatin mass ratios of 0.20, 0.25 and 0.29 were measured to be 3450, 4300 and 4950 Pa and 12.5, 14.0 and 15.0 Pa⋅s, respectively. The shear modulus and viscosity of the phantom increases as the gelatin mass ratio increases. The frequency of oscillations of the hemisphere placed at the phantom interface increases as the gelatin mass ratio increases due to stiffness increase. Conclusions: After matching the experimental and theoretical steady-state displacements and amplitudes of oscillations of the hemisphere at the sample interface, the comparison of the experimentally identified and theoretically predicted frequency of oscillations further confirmed the identified material properties of the samples. The approach presented here is expected to provide valuable information on material properties in biomedical and industrial applications.WOS:0010826474000032-s2.0-85174051012ArticleUluslararası işbirliği ile yapılan - EVET2023YÖK - 2022-23Eki

Identification of the viscoelastic properties of soft materials using a convenient dynamic indentation system and procedure

The responses of soft structures such as tissue depend on their viscoelastic properties. Therefore, the knowledge of the elastic and damping properties of soft materials is of great interest. This paper presents the identification of the viscoelastic properties of soft materials using a convenient dynamic indentation system and procedure. Using an electromagnet, a force is applied to a rigid sphere located at the soft-material interface and the dynamic response of the sphere is recorded using a high-speed camera. The recorded video is processed to identify the displacement of the sphere as a function of time. The dynamic response of the sphere located at the soft-material interface is predicted using an analytical model that considers the shear modulus and density of the soft sample, the radiation damping due to shear waves, and the radius and density of the sphere. By matching the measured and predicted steady-state displacements of the sphere, the shear modulus of the soft sample is determined. The viscous damping ratio of the soft sample is identified by using an equivalent viscous damping ratio for the soft sample in the analytical model and matching the measured and predicted oscillation amplitudes of the sphere. Experiments and analyzes are performed using gelation phantoms with different mechanical properties, spheres of different materials and sizes, and different force levels to verify the system and procedure. Three experiments are performed for each gelation phantom, sphere, and external force, and the repeatability of the results is presented. The results show that the dynamic indentation system and procedure presented in this study can be conveniently used to determine the viscoelastic properties of soft materials in practical applications.WOS:000797600100022Scopus - Affiliation ID: 60105072Conference Proceedings Citation IndexProceedings PaperUluslararası işbirliği ile yapılmayan - HAYIR2022YÖK - 2021-22Oca

Clinical Course of Hashimoto's Thyroiditis and Effects of Levothyroxine Therapy on the Clinical Course of the Disease in Children and Adolescents

Objective: The aim of this study was to evaluate the clinical course of Hashimoto’s thyroiditis (HT) in children and adolescents and the effects of levothyroxine therapy on the clinical course and laboratory findings

Long-term results of chronic achilles tendon ruptures repaired with V-Y tendon plasty and fascia turndown

Background: This study aimed to evaluate the long-term follow-up results of V-Y tendon plasty with fascia turndown, for repairing chronic Achilles tendon ruptures. Methods: Seventeen patients (12 males, 5 females), who were diagnosed with chronic Achilles tendon rupture and met the inclusion criteria, were included in the study. These patients received treatment by means of V-Y tendon plasty with fascia turndown from January 1995 to December 2001. Clinical outcomes of the patients were assessed by using isokinetic strength testing, questioning the patient regarding residual discomfort, pain, or swelling and having the ability to perform heel rises and using American Orthopaedic Foot & Ankle Society’s (AOFAS’s) Ankle-Hind Foot Scale score. Mean followup duration was 16 years (13-18 years). Results: Mean time from the injury to operative treatment was 7 months. Mean operative defect of Achilles tendon in neutral position after debridement was 6 cm. During the follow-up, the mean calf atrophy was 3.4 cm. The mean 30 degrees/s plantarflex and 120 degrees/s plantarflex peak torques were 89 and 45 Nm, respectively. The mean 30 degrees/s plantarflex peak torque deficiency was 16%. The mean 120 degrees/s plantarflex peak torque deficiency was 17%. The average peak torque deficiency was 17%. The pre- and postoperative mean AOFAS Ankle-Hindfoot Scale scores were 64 and 95, respectively. No patient had a rerupture. Superficial wound infection was treated with oral antibiotic therapy in 2 patients (11%). Conclusions: The V-Y tendon plasty with fascia turndown for repairing chronic Achilles tendon ruptures yielded results comparable with the literature regarding clinical outcomes. This method did not require synthetic materials for augmentation and was an economic alternative compared to other repair methods. Level of Evidence: Level III, retrospective comparative study

Texture development in hydroentangled nonwovens

Kısa bir süre önce eş-oluşum(co-occurrence) temeline dayanan bir görünüm analiz metoduyla ilgili bir makalemizi sunduk. Bu makalemizde de aynı görünüm analiz metodunu kullanılarak, suyla iğnelenmiş (dolaştırılmış) dokunmamış kumaşlardaki yüzey görünümünün işlem parametrelerine bağlı olarak gelişimini inceleyeceğiz. Görünümdeki değişimi suyla iğneleme enerjisiyle ilişkilendirerek verilerimizi değerlendireceğiz. İşlem enerjisi, makinadaki basınç değişimi ve  geçiş sayısına göre kontrol edilmiş, tüm  kumaşlar aynı tül  ve aynı destek bandı üzerinde üretilmiştir. Verilerimiz bize, yüzey belirginliğinin basınç ile doğru orantılı olarak belli bir değere kadar iyileştiğini ve daha sonra ise görünümün bozulduğunu göstermiştir.Anahtar Kelimeler: Görünüm analizi, suyla iğneleme(dolaştırma), spesifik enerji, eş-oluşum yöntemi.The intention of this research is to develop an optical method and a turnkey imaging system for classifying texture in hydroentangled nonwovens. This paper uses this texture analysis method to examine the development of the texture during hydroentangling as a function process conditions. We report on the development of texture as a function of hydroentangling energy.  Energy was varied by controlling the pressure and number of passes. 1.7 dtex PET was selected as the fiber. A pilot-scale Honeycomb hydroentangling machine was used to produce fabrics under varying pressures and number of passes.  All fabrics were produced using the same web on the same forming belt substrate. Our data indicated that co-occurrence analysis is a good indicator for determining the surface texture properties. We have demonstrated that horizontal and vertical contrast functions and their respective power spectral analysis data will provide a useful tool for quantifying texture. We have also showed that hydroentangling pressure has a marked effect on the manner in which texture develops during the process. In general, increasing pressure and the number of passes will result in a better texture definition up to a certain point provided that the web is sufficiently consolidated.  If the web is not consolidated, higher pressures will result in perturbing the web with a concomitantly lower texture definition.Keywords: Texture analysis, hydroentanglement, specific energy, co-occurrence method.

Time between first and second transurethral resection of bladder tumors in patients with high-grade t1 tumors: is it a risk factor for residual tumor detection?

Purpose: We evaluated the risk factors for residual tumor detection after transurethral resection of bladder tumors (TURBT) in patients with newly diagnosed high-grade T1 transitional cell carcinoma of the bladder. Patients and Methods: Overall 132 patients underwent TURBT for primary bladder tumors and were diagnosed as high-grade T1 bladder cancer. Patients with incomplete resections were excluded from the study. Clinical and pathologic characteristics of the patients were compared and multivariate analysis was performed to determine independent prognostic factors. Results: Residual tumor was demonstrated in 57 (43.1%) of the patients. The residual tumor rate was significantly lower in patients with solitary tumors, tumors 3 cm in size, absence of detrusor muscle in the initial TURBT specimen, TURBT performed by trainees and finally, as a new finding, prolonged interval between first and second TURBT are independent predictors for residual tumor detection in patients with high-grade T1 tumors. (c) 2013 S. Karger AG, Base

Titration of betaine therapy to optimize therapy in an infant with 5,10-methylenetetrahydrofolate reductase deficiency

PubMed ID: 19434424Betaine therapy was given for 2 years to a 2- year-old boy with 5,10-methylenetetrahydrofolate reductase deficiency. Used as a methyl donor to lower homocysteine levels through methylation of methionine, betaine has been reported to be effective in treating homocystinuria. Satisfactory biochemical and clinical responses were obtained with the following regimen: betaine started in the newborn period at increasing doses to reach 1 g given six times a day. It is suggested that frequent administration of a moderate dose may provide clinical and biochemical benefit. © Springer-Verlag 2009

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Hashimoto tiroiditinin çocuk ve ergenlerde seyri, Na- L tiroksin tedavisinin antikor titreleri üzerine etkisi

Bu çalışmanın amacı, ötiroit Hashimoto tiroiditinde Na-L Tiroksin tedavisinin hastalığın klinik seyrine, olguların büyümesine ve antikor titreleri üzerine etkisinin araştırılmasıdır Çalışma, Ege Üniversitesi Tıp Fakültesi Pediatrik Endokrinoloji Polikliniği'ne 2002-2008 yılları arasında başvuran, laboratuvar ve klinik bulguları ile Hashimoto tiroiditi tanısı almış, yaşları 4 ile 18 arasında olan 101 olgunun dosyalarından elde edilen veriler ile yürütülmüştür. Olguların verileri başlangıç, 350±137 günlük 1. izlem dönemi, 786 ±296 günlük 2. izlem dönemi olarak gruplandırılarak değerlendirilmiştir Ortalama hasta yaşı 12,3 ± 2,90, kız/erkek oranı 5,7/1 olarak saptanmıştır. Hastaların en sık başvuru yakınması %58 oranında boyunda şişlik yakınması olurken, bu yakınmayı %18 ile sinirlilik, %13 ile dermatolojik problemler izlemiştir. Erkek olguların %33'ünün kız olguların ise %28'inin annesinde, babasında ya da kardeşinde tiroit fonksiyon bozukluğu ve/veya guatr saptanmıştır Çalışmaya dahil edilen grubun %63'ünü yeni tanı alan, %37'sini ise dış merkezden tedavi başlanarak yönlendirilen hastalar oluşturmuştur. Yeni tanı alan hastaların %34'ü subklinik hipotiroidi %39'u ötiroidi %14'ü hipotiroidi durumunda bulunmuştur. Tedavi alan ve almayan hastaların başvurudaki Anti-T, Anti-M değerleri ve antropometrik ölçümleri arasında anlamlı fark saptanmamıştır Başlangıçta tedavi almayan ve araştırmanın sonuna kadar izlenen subklinik hipotiroidili 15 olgunun 13 tanesinde izlemde TSH yüksekliği yada aşikar hipotiroidizm kliniği gelişmesi nedeniyle tedavi başlanmıştır. Tedavi başlanmayan olguların 1 tanesi hipotiroidi, 1 tanesi ise ötiroidi kliniğinde geçtiği saptanmıştır. Başlangıçta tedavi kullanmayan ve araştırma sonuna dek izlenen 20 ötiroid olgunun ise 13 tanesine tedavi başlanmıştır. Tedavi başlanmayan 7 olgunun 4 tanesi araştırma sonunda hipotiroidi durumunda geçerken, 3 tanesi ise ötiroidi olarak izlenmiştir. Bu sonuç literatüre paralel şekilde subklinik hipotiroidi ve ötiroidi olan olguların, uzun süreli izlemde, nihai olarak hipotiroidi kliniğine geçiş yaptığını göstermektedir Başvuru anında olguların % 37'si tedavi görür durumda ve % 63'ü ise tedavisiz iken, 1. izlem periyodu sonrasında bu oran sırası ile %70'e ve %30 ve 2. izlem dönemi sonrasında %85'e ve %15 olarak tedavi görenler lehine değişmiştir Başlangıçtan beri tedavi alan ve tüm araştırma süresince izlenen 30 kişilik grupta Anti-T ortalama değerleri 472 IU/ml den 252'ye IU//ml gerilemiştir (P=0,01). Tedavi almayan grupta da Anti-T değerlerleri ortalaması 487 IU/ml den 136 IU/ml 'ye gerilemesine karşın bu düşüş anlamlı bulunmamıştır. Tedavi alan ve almayan gruplardaki Anti-T değerlerindeki değişim karşılaştırıldığında da sonuç yine anlamlı olarak saptanmamıştır. Anti- M değerlerindeki değişim ise her iki grup için anlamlı bulunmamıştır Çalışmamızda hastaların başvuru, 1. izlem dönemi ve 2. izlem dönemindeki Anti-T ve Anti-M değerlerine bakıldığında, olguların izlem süresindeki klinik durumları ile Anti-T ve Anti-M değerlerindeki değişiklikler arasında ilişki kurulamamıştır. Burada klinik durumu etkileyen ve sonuçları yorumlamayı güçleştiren, bizim araştırmamızda değerlendirmeye alınmamış olan diğer otoantikorların etkisi olabileceği düşünülmüştür Hashimoto tiroiditi olan hastaların en sık başvuru nedenlerinden bir tanesi de büyüme geriliği olmasına karşın araştırmada tedavi kullanan ve kullanmayan hastaların, başvurudaki, 1. izlem dönemindeki ve 2. izlem dönemindeki Boy SDS, Ağırlık SDS ve VKİ SDS'leri arasında anlamlı fark bulunmamamıştır. Bunun nedeni olarak olguların tüm izlem süresince sadece %8 -17'si oranında hipotiroidi saptanmış olması ve hipotiroidili hastalara uzun süreli izlemde müdahale edilerek büyük oranda ötiroidi durumuna getirilmesinin olabileceği düşünülmüştür