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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only 1,3-bis(gamma-aminopropyl)tetramethyldisiloxane modified epoxy resins: curing and characterization(Elsevier, 1998) Department of Chemistry; Department of Chemistry; Yılgör, Emel; Yılgör, İskender; Researcher; Faculty Member; Department of Chemistry; College of Sciences; College of Sciences; 40527; 24181Incorporation of siloxane oligomers with reactive organofunctional terminal groups, such as amine, epoxy and carboxy, into the structure of epoxy networks, provides improvements in the fracture toughness, water absorption and surface properties of the resultant systems. 1,3-bis(gamma-aminopropyl) tetramethyldisiloxane (DSX) was used as a model curing agent and modifier in bis(4-aminocyclohexyl)methane (PACM-20) cured diglycidyl ether of bisphenol-A (DGEBA) based epoxy resins. Curing reactions followed by differential scanning calorimetry indicated faster reaction rates between DSX and DGEBA as compared with PACM-20 and DGEBA. Mechanical characterization of the modified products showed improvements in tensile and impact strengths as expected. Glass transition temperatures of these materials showed a decrease with an increase in DSX content.Publication Metadata only 1.07 - Rubberlike elasticity(Elsevier, 2012) Mark, J.E.; Department of Chemical and Biological Engineering; Erman, Burak; Faculty Member; Department of Chemical and Biological Engineering; College of Engineering; 179997Molecular structure, molecular and phenomenological theories, and computer simulations of amorphous rubberlike polymeric networks of rubber elasticity are discussed. Behavior of responsive gels, multimodal, liquid-crystalline, and reinforced elastomers in the state of thermodynamic equilibrium are outlined. Characterization of structure and properties based on stress–strain experiments, optical and spectroscopic techniques, scanning tunneling microscopy, atomic force microscopy, nuclear magnetic resonance, small-angle and Brillouin scattering, and pulse wave propagation are outlined. © 2012 Elsevier B.V. All rights reserved.Publication Metadata only 10-NJ multipass-cavity femtosecond CR3+: LiCAF laser pumped by low-power single-mode diodes(Optical Society of America, 2009) Kärtner, Franz X.; Fujimoto, James G.; Demirbaş, Ümit; Department of Physics; Sennaroğlu, Alphan; Faculty Member; Department of Physics; College of Sciences; 23851We report on the generation of 9.9-nJ, 95-fs pulses at a repetition rate of 9.58 MHz from a multipass-cavity Cr3+:LiCAF laser pumped by single-mode diodes with a total absorbed pump power of only 540 mW.Publication Metadata only 1200 nm pumped Tm3+:Lu2O3 ceramic lasers(Optical Soc Amer, 2018) Özharar, Sarper; N/A; Department of Physics; Toker, Işınsu Baylam; Sennaroğlu, Alphan; PhD Student; Faculty Member; Department of Physics; N/A; College of Sciences; N/A; 23851We report on an experimental demonstration of a 1200-nm pumped Tm3+:Lu2O3 ceramic laser. By using a gain-switched, tunable Cr4+:forsterite laser, the excitation spectrum was measured, with optimum pumping bands centered near 1198 nm, 1204 nm, and 1211 nm. The highest slope efficiency of 21.5% was obtained at the pump wavelength of 1204 nm. Comparative energy efficiency measurements performed near 1200-nm and 800-nm pumping further showed that nearly 40% improvement was obtained in slope efficiency measured with respect to the incident pump energy for 1200-nm pumping. A transition was further observed from single-wavelength operation at 2066 nm to dual-wavelength operation near 2066 nm and 1967 nm for absorbed pump energies above 50 mu J. In this regime, two consecutive output pulses were observed in the time domain. The shortest temporal duration of the first pulse was 1.1 mu s at the incident pulse energy of 105 mu J. The duration and build-up time of the second pulse remained around 5.9 mu s and 18.5 mu s. We believe that the improved energy efficiency demonstrated for the 1.5% Tm3+:Lu2O3 ceramic with 1200-nm pumping can be used as an alternative scheme for the excitation of Tm3+:Lu2O3 ceramic lasers.Publication Metadata only 16.4: the optics of an autostereoscopic multiview display(SID, 2010) Baghsiahi, Hadi; Selviah, David R.; Willman, Eero; Fernández, Anibal; Day, Sally E.; Surman, Phil A.; N/A; Department of Electrical and Electronics Engineering; Department of Electrical and Electronics Engineering; Erden, Erdem; Chellappan, Kishore Velichappattu; Ürey, Hakan; Master Student; Researcher; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 8579An autostereoscopic head-tracked back projection display that uses an RGB laser illumination source and a fast light engine is described. Images are horizontally scanned columns controlled by a spatial light modulator that directs two or more images in the directions of the apposite viewers 'eyes.Publication Metadata only 18F-FDG PET/CT imaging in a patient with a rare diagnosis of sarcomatoid malignant peritoneal mesothelioina(Lippincott Williams & Wilkins, 2013) Tokmak, Handan; Demirkol, Onur M.; Kaban, Kerim; N/A; Mandel, Nil Molinas; Dilege, Şükrü; Faculty Member; Faculty Member; School of Medicine; School of Medicine; 194197; 122573Malignant peritoneal mesothelioma is an uncommon but deadly disease arising from serosal surfaces of the peritoneum. Asbestos exposure is the most recognized risk factor. We report a case of diffuse, sarcomatoid malignant peritoneal mesothelioma who presented to the hospital with abdominal pain. The patient had an abdominal MRI scan as initial scanning which demonstrated nonspecific findings suspected of peritoneal carcinomatosis. The patient was admitted to our department for the metabolic characterization of the lesions with F-18-FDG PET/CT imaging and the diagnosis of the primary malignancy. F-18-FDG PET/CT imaging revealed diffusely increased metabolic activity throughout the peritoneum and the histopathological features were compatible with sarcomatoid malignant peritoneal mesothelioma.Publication Metadata only 18F-FDG PET/CT mean suv and metabolic tumor volume for mean survival time in non-small cell lung cancer(Lippincott Williams and Wilkins, 2015) Kurtipek, Ercan; Çaycı, Mustafa; Düzgün, Nuri; Esme, Hıdır; Terzi, Yüksel; Bakdık, Süleyman; Ünlü, Yaşar; Burnik, Cengiz; Bekçi, Taha Tahir; N/A; Aygün, Murat Serhat; Teaching Faculty; School of Medicine; Koç University Hospital; 291692Objective: The study was designed to determine the relationship between survival time of standardized uptake value (SUVmax and SUVmean) and metabolic tumor volume (MTV) in patients with non-small cell lung cancer (NSCLC), and examine the impact of demographic, clinical, and radiological data of these patients on survival. Materials and Methods: We performed a retrospective analysis of the records of 79 patients with NSCLC who presented to our hospital between May 2010 and March 2013, received a final diagnosis, and underwent 18F-FDG PET/CT for staging. Clinical, radiological, and 18F-FDG PET/CT parameters with an impact on prognosis such as the SUVmax of the primary tumor as calculated by the volumetric region of interest in the 18F-FDG PET/CT scans during initial diagnosis, mean SUV of the tumor, and MTV obtained with a threshold of SUVmax greater than 2.5 were recorded and statistically analyzed. A statistical analysis was carried out based on the clinical, radiological, and PET/CT findings of the patients who were divided into 2 groups: survivors and nonsurvivors. Results: Seventy patients (88.6%) were men, and 9 (11.4%) were women. The mean age was 63.65 ± 11.51 years in the nonsurvivor group (n = 40) versus 62.74 ± 10.60 years in the survivor group (n = 39) (Table 1). The mean survival time from diagnosis was 7.9 ± 6.52 months in the nonsurvivor group versus 14.09 ± 7.41 months in the survivor group. The mean survival time was 12.9 ± 7.9 months for those aged 60 or younger, whereas it was 9.9 ± 7.2 years for those aged 60 or older. According to the Cox regression analysis, higher MTV [relative risk (RR), 1.006; P = 0.03] and mean SUVmax (mSUV) (RR, 1.302; P = 0.03) had a significant impact on shortening of the mean survival time. However, no statistical significance was reached for SUVmax measurements (RR, 0.970; P = 0.39). Furthermore, there was a significant relationship between increased tumor size (andlt;2 cm, 2-4 cm, and ≥4 cm) and shortened mean survival time (P = 0.03). Conclusion: The present study showed that MTV and mSUV of FDG PET/CT scans of the tumor, but not SUVmax, had a significant impact on survival time of patients with NSCLC. Based on this result, we believe that we might have more accurate information about the survival time of our patients if we also evaluate mSUV and MTV in combination with mSUV, which is frequently used for diagnosis and monitoring of patients with NSCLC during our daily practice. © 2015 Wolters Kluwer Health, Inc. All rights reserved.Publication Metadata only 18F-FDG PET/CT texture analysis of anthracotic lymph nodes detected with EBUS and comparison with cytological findings(P.Ziti and Co, 2022) N/A; N/A; N/A; N/A; N/A; N/A; N/A; N/A; Çağlayan, Benan Niku; Fırat, Pınar Arıkan; Seymen, Hülya; Bulutay, Pınar; Falay, Fikri Okan; Demirtaş, Elif; Demirkol, Mehmet Onur; Meriçöz, Çisel Aydın; Faculty Member; Faculty Member; Teaching Faculty; Teaching Faculty; Teaching Faculty; Master Student; Faculty Member; Teaching Faculty; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; Graduate School of Health Sciences; School of Medicine; School of Medicine; 230719; 207545; 350778; 133565; 246484; N/A; 196946; 162418Objective: Lymph node metastasis is the most important factor both in the selection of treatment since many alternatives have been created in recent years, and in the evaluation of prognosis in lung cancer. The most unpredictable cause of lymph node false positivity in fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is anthracosis. The aim of this study is to compare 18F-FDG PET/CT texture information of anthracotic (ALN) and metastatic (MLN) lymph nodes, after re-evaluation of the cytological samples obtained from anthracotic lymph nodes by EBUS-TBNA. Subjects and Methods: Ninety nine patients, 78 of whom had primary lung cancer were included in the study. Two hundred and three lymph nodes from 99 patients sampled by EBUS-TBNA and diagnosed cytologically as ALN or MLN were evaluated retrospectively. All ALN were classified as grades 1, 2 and 3 cytologically. Volume of interest (VOI) of 203 lymph nodes was re-drawn and maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) values were recorded. Results: There was a statistically significant difference in MTV and TLG values in MLN and all ALN grades. However, only grade 1-2 ALNs could be differentiated from MLNs with SUVmax, and no statistically significant difference was found in grade 3 ALN and MLN. Metabolic tumor volume and TLG values over 4.10cm3 and 26.57 showed 60% and 59% sensitivity and 83% and 94 specificity respectively for the identification of MLN. Conclusion: The contribution of MTV and TLG values of 18F-FDG PET/CT to the differential diagnosis of ALN is much more valuable than SUVmax values, especially for grade 3 anthracosis. It was thought that cytological reporting of only grade 3 ALN could make a better contribution to the 18F-FDG PET/CT evaluation analysis.Publication Metadata only 21 fs Cr:LiSAF laser mode locked with a single-walled carbon nanotube saturable absorber(Optical Soc Amer, 2019) Bae, Ji Eun; Rotermund, Fabian; Demirbaş, Ümit; N/A; N/A; N/A; Department of Physics; Tanısalı, Gökhan; Toker, Işınsu Baylam; Taşçı, Mısra; Sennaroğlu, Alphan; PhD Student; PhD Student; Undergraduate Student; Faculty Member; Department of Physics; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; School of Medicine; College of Sciences; N/A; N/A; N/A; 23851We report the shortest femtosecond pulses directly generated from a solid-state laser that is mode locked by using a single-walled carbon nanotube saturable absorber (SWCNT-SA). In the experiments, we used a 660 nm diode-pumped, low-threshold extended-cavity Cr:LiSAF laser operating around 850 nm with a repetition rate of 47.9 MHz. The SWCNT-SA mode-locked Cr:LiSAF laser produced 21 fs pulses with a time-bandwidth product of 0.56 by using only 210 mW of pump power. Pump-probe spectroscopy measurements showed that the SWCNT-SA exhibited saturable absorption with slow and fast decay times of 2.7 ps and 0.4 ps. The single-pass modulation depth and saturation fluence of the SWCNT-SA were further determined as 0.3% and 45 mu J/cm(2) at the pump wavelength of 850 nm.Publication Metadata only 268th ENMC workshop - Genetic diagnosis, clinical classification, outcome measures, and biomarkers in Facioscapulohumeral Muscular Dystrophy (FSHD): Relevance for clinical trials(Elsevier B.V., 2023) Montagnese F, de Valle K, Lemmers RJLF, Mul K, Dumonceaux J, Voermans N; 268th ENMC workshop participants.; Oflazer, Piraye; ; School of Medicine;Highlights This ENMC workshop has seen the participation of many important stakeholders working together to improve trial readiness in FSHD: patients and patients’ organizations (FSHD-Europe, FSHD-Society and FSHD Global), neuromuscular clinicians, geneticists, basic researchers, representatives of the TREAT-NMD network, the FSHD-CTRN and EMA. COMs represent useful tools for the standardized collection of clinical features but need to be selected to match the clinical setting of use. For patient care, they need to be informative, with practical and time efficient utility so as not to detract from clinical care. For clinical trial purposes, the need to be reliable, valid, meaningful and sensitive to change to better depict therapeutic responses. An optimized clinical evaluation and genetic test form is one of the goals of WG1 and 2. A diagnostic flowchart for FSHD1 and FSHD2 has been proposed. Another important unmet need for clinical trial readiness in FSHD is the identification of good therapeutic biomarkers, which ideally should be quantitative, non-invasive, applicable across the entire range of disease severity, sensitive to change, reliable and clinically meaningful. The WG 3 will produce standard operating procedures (SOPs) for DUX4 detection. Similarly, large differences in the reporting of studies performed on animal models, thus hindering interpretation, repeatability and comparison of the results need to be addressed. Guidelines regarding minimum information for publication of work including animal models for FSHD will therefore be published.Publication Metadata only 2d -> 3d polycatenated and 3d -> 3d interpenetrated metal-organic frameworks constructed from thiophene-2,5-dicarboxylate and rigid bis(imidazole) ligands(Elsevier, 2014) Erer, Hakan; Yesilel, Okan Zafer; Arici, Mursel; Buyukgungor, Orhan; Department of Chemical and Biological Engineering; Keskin, Seda; Faculty Member; Department of Chemical and Biological Engineering; College of Engineering; 40548Hydrothermal reactions of rigid 1,4-bis(imidazol-1-yl)benzene (dib) and 1,4-bis(imidazol-1-yl)-2, 5-dimethylbenzene (dimb) with deprotonated thiophene-2,5-dicarboxylic acid (H(2)tdc) in the presence of Zn(II) and Cd(II) salts in H2O produced three new metal-organic frameworks, namely, [Zn(mu-tdc)(H2O) (mu-dib)](n) (1), [Cd(mu-tdc)(H2O)(mu-dib)(n) (2), and {[Cd-2(mu(3)-tdc)(2)(mu-dimb)(2)] center dot (H2O)}(n) (3). These MOFs were characterized by FT-IR spectroscopy, elemental, thermal (TG, DTA, DTG and DSC), and single-crystal X-ray diffraction analyses. Isomorphous complexes 1 and 2 reveal polycatenated 2D+2D -> 3D framework based on an undulated (4,4)-sql layer. Complex 3 exhibits a new 4-fold interpenetrating 3D framework with the point symbol of 6(6). Molecular simulations were used to assess the potentials of the complexes for H-2 storage application. Moreover, these coordination polymers exhibit blue fluorescent emission bands in the solid state at room temperature.Publication Metadata only 2D scanning MEMS stage integrated with microlens arrays for high-resolution beam steering(IEEE, 2009) Department of Electrical and Electronics Engineering; N/A; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Ürey, Hakan; Gökçe, Sertan Kutal; Holmstrom, Sven; Arslan, Aslıhan; Ataman, Çağlar; Seren, Hüseyin Rahmi; Faculty Member; Master Student; Researcher; Master Student; PhD Student; Master Student; Other; Department of Electrical and Electronics Engineering; College of Engineering; Graduate School of Sciences and Engineering; College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; N/A; 8579; N/A; N/A; N/A; N/A; N/A; N/AA novel MEMS stage using one set of comb fingers, capable of 2-axis motion is designed and developed. With an integrated 1.1mm square microlens-array it deflects 40um in-plane at 60V and 95um out-of-plane at 100V.Publication Metadata only 32 novel pathogenic sequence variants in 253 DMD/BMD patients from Turkey(Nature Publishing Group, 2018) Toksoy, G.; Aghayev, A.; Bagirova, G.; Tekce, H. Durmus; Avci, S.; Altunolu, U.; Parman, Y.; Oflazer, P.; Yapici, Z.; N/A; Kayserili, Hülya; Faculty Member; School of Medicine; 7945N/APublication Metadata only 3D articulated shape segmentation using motion information(Institute of Electrical and Electronics Engineers (IEEE), 2010) Department of Computer Engineering; N/A; Yemez, Yücel; Kalafatlar, Emre; Faculty Member; Master Student; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; 107907; N/AWe present a method for segmentation of articulated 3D shapes by incorporating the motion information obtained from time-varying models. We assume that the articulated shape is given in the form of a mesh sequence with fixed connectivity so that the inter-frame vertex correspondences, hence the vertex movements, are known a priori. We use different postures of an articulated shape in multiple frames to constitute an affinity matrix which encodes both temporal and spatial similarities between surface points. The shape is then decomposed into segments in spectral domain based on the affinity matrix using a standard K-means clustering algorithm. The performance of the proposed segmentation method is demonstrated on the mesh sequence of a human actor.Publication Metadata only 3D display dependent quality evaluation and rate allocation using scalable video coding(Ieee, 2009) N/A; N/A; Department of Electrical and Electronics Engineering; Saygılı, Görkem; Gürler, Cihat Göktuğ; Tekalp, Ahmet Murat; Master Student; PhD Student; Faculty Member; Department of Electrical and Electronics Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 26207It is well known that the human visual system can perceive high frequency content in 3D, even if that information is present in only one of the views. Then, the best 3D perception quality may be achieved by allocating the rates of the reference (right) and auxiliary (left) views asymmetrically. However the question of whether the rate reduction for the auxiliary view should be achieved by spatial resolution reduction (coding a downsampled version of the video followed by upsampling after decoding) or quality (QP) reduction is an open issue. This paper shows that which approach should be preferred depends on the 3D display technology used at the receiver. Subjective tests indicate that users prefer lower quality (larger QP) coding of the auxiliary view over lower resolution coding if a "full spatial resolution" 3D display technology (such as polarized projection) is employed. On the other hand, users prefer lower resolution coding of the auxiliary view over lower quality coding if a "reduced spatial resolution" 3D display technology (such as parallax barrier - autostereoscopic) is used. Therefore, we conclude that for 3D IPTV services, while receiving full quality/resolution reference view, users should subscribe to differently scaled versions of the auxiliary view depending on their 3D display technology. We also propose an objective 3D video quality measure that takes the 3D display technology into account.Publication Metadata only 3D face recognition(Institute of Electrical and Electronics Engineers (IEEE), 2006) Dutaǧaci, H.; Sankur, B.; Department of Computer Engineering; Yemez, Yücel; Faculty Member; Department of Computer Engineering; College of Engineering; 107907In this paper, we compare face recognition performances of various features applied on registered 3D scans of faces. The features we compare are DFT or DCT- based features, ICA-based features and NNMF-based features. We apply the feature extraction techniques to three different representations of registered faces: 3D point clouds, 2D depth images and 3D voxel representations. We also consider block-based DFT or DCT-based local features on 2D depth images and their fusion schemes. Experiments using different combinations of representation types and feature vectors are conducted on the 3D-RMA dataset. / Bu bildiride, kayıtlı 3B yüz taramalarında uygulanan çeşitli özelliklerin yüz tanıma performanslarını karşılaştırıyoruz. Karşılaştırdığımız özellikler, DFT veya DCT tabanlı özellikler, ICA tabanlı özellikler ve NNMF tabanlı özelliklerdir. Öznitelik çıkarma tekniklerini kayıtlı yüzlerin üç farklı temsiline uyguluyoruz: 3B nokta bulutları, 2B derinlik görüntüleri ve 3B voksel temsilleri. Ayrıca, 2D derinlik görüntüleri ve bunların füzyon şemaları üzerindeki blok tabanlı DFT veya DCT tabanlı yerel özellikleri de dikkate alıyoruz. 3D-RMA veri seti üzerinde farklı temsil türleri ve özellik vektörleri kombinasyonları kullanılarak deneyler yapılmıştır.Publication Metadata only 3D isometric shape correspondence(IEEE, 2010) Department of Computer Engineering; Yemez, Yücel; Sahillioğlu, Yusuf; Faculty Member; PhD Student; Department of Computer Engineering; College of Engineering; Graduate School of Sciences and Engineering; 107907; 215195We address the problem of correspondence between 3D isometric shapes. We present an automatic method that finds the optimal correspondence between two given (nearly) isometric shapes by minimizing the amount of deviation from isometry. We optimize the isometry error in two steps. In the first step, the 3D points uniformly sampled from the shape surfaces are transformed into spectral domain based on geodesic affinity, where the isometry errors are minimized in polynomial time by complete bipartite graph matching. The second step of optimization, which is well-initialized by the resulting correspondence of the first step, explicitly minimizes the isometry cost via an iterative greedy algorithm in the original 3D Euclidean space. Our method is put to test using (nearly) isometric pairs of shapes and its performance is measured via ground-truth correspondence information when available.Publication Metadata only 3D model retrieval using probability density-based shape descriptors(IEEE Computer Society, 2009) Akgul, Ceyhun Burak; Sankur, Buelent; Schmitt, Francis; Department of Computer Engineering; Yemez, Yücel; Faculty Member; Department of Computer Engineering; College of Engineering; 107907We address content-based retrieval of complete 3D object models by a probabilistic generative description of local shape properties. The proposed shape description framework characterizes a 3D object with sampled multivariate probability density functions of its local surface features. This density-based descriptor can be efficiently computed via kernel density estimation (KDE) coupled with fast Gauss transform. The nonparametric KDE technique allows reliable characterization of a diverse set of shapes and yields descriptors which remain relatively insensitive to small shape perturbations and mesh resolution. Density-based characterization also induces a permutation property which can be used to guarantee invariance at the shape matching stage. As proven by extensive retrieval experiments on several 3D databases, our framework provides state-of-the-art discrimination over a broad and heterogeneous set of shape categories.Publication Metadata only 3D object matching via multivariate shape distributions(Institute of Electrical and Electronics Engineers (IEEE), 2005) Akgül, C.B.; Sankur, B.; Schmitt, F.; Department of Computer Engineering; Yemez, Yücel; Faculty Member; Department of Computer Engineering; College of Engineering; 1079073B nesne eşleştirme literatüründe, problemi şekil dağılımlarının karşılaştırılmasına indirgeyen yöntemler bulunmaktadır. Şekil dağılımı, 3B nesne yüzeyi üzerinde hesaplanan bir işlevin değerlerinin olasılık dağılımı olarak tanımlanır. Bu çalışmada varolan yöntemi, birden çok işlevin getirdiği şekil bilgisinden aynı anda yararlanacak şekilde genişletiyoruz. Çokboyutlu şekil dağılımları adını verdiğimiz bu 3B nesne betimleyicilerini, örnek bir 3B nesne veri tabanındaki nesneler için parametrik olmayan yaklaşımlarla kestiriyor, karşılaştırmaları alternatif metrikler yoluyla yapıyoruz. Elde edilen kesinlik-geri getirme eğrileri çokboyutlu şekil dağılımlarının karşılaştırılmasının yeni bir 3B nesne eşleştirme paradigması olabileceğini göstermektedir.Publication Metadata only 3D printed biodegradable polyurethaneurea elastomer recapitulates skeletal muscle structure and function(American Chemical Society (ACS), 2021) Gokyer, Seyda; Berber, Emine; Vrana, Engin; Orhan, Kaan; Abou Monsef, Yanad; Guvener, Orcun; Zinnuroglu, Murat; Oto, Cagdas; Huri, Pinar Yilgor; Department of Chemistry; Department of Chemistry; Yılgör, Emel; Yılgör, İskender; Researcher; Faculty Member; Department of Chemistry; College of Sciences; College of Sciences; N/A; 24181Effective skeletal muscle tissue engineering relies on control over the scaffold architecture for providing muscle cells with the required directionality, together with a mechanical property match with the surrounding tissue. Although recent advances in 3D printing fulfill the first requirement, the available synthetic polymers either are too rigid or show unfavorable surface and degradation profiles for the latter. In addition, natural polymers that are generally used as hydrogels lack the required mechanical stability to withstand the forces exerted during muscle contraction. Therefore, one of the most important challenges in the 3D printing of soft and elastic tissues such as skeletal muscle is the limitation of the availability of elastic, durable, and biodegradable biomaterials. Herein, we have synthesized novel, biocompatible and biodegradable, elastomeric, segmented polyurethane and polyurethaneurea (TPU) copolymers which are amenable for 3D printing and show high elasticity, low modulus, controlled biodegradability, and improved wettability, compared to conventional polycaprolactone (PCL) and PCL-based TPUs. The degradation profile of the 3D printed TPU scaffold was in line with the potential tissue integration and scaffold replacement process. Even though TPU attracts macrophages in 2D configuration, its 3D printed form showed limited activated macrophage adhesion and induced muscle-like structure formation by C2C12 mouse myoblasts in vitro, while resulting in a significant increase in muscle regeneration in vivo in a tibialis anterior defect in a rat model. Effective muscle regeneration was confirmed with immunohistochemical assessment as well as evaluation of electrical activity produced by regenerated muscle by EMG analysis and its force generation via a custom-made force transducer. Micro-CT evaluation also revealed production of more muscle-like structures in the case of implantation of cell-laden 3D printed scaffolds. These results demonstrate that matching the tissue properties for a given application via use of tailor-made polymers can substantially contribute to the regenerative outcomes of 3D printed tissue engineering scaffolds.