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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 3D printed kombucha biomaterial as a tissue scaffold and L929 cell cytotoxicity assay(Wiley, 2024) Yanbakan, Edaguel; Tuncel, Tugba; Kocak Sezgin, Ayse; Bozoglan, Emirhan; Berikten, Derya; Kar, Fatih; Department of Molecular Biology and Genetics; Bağlan, İlkyaz; Department of Molecular Biology and Genetics; College of SciencesTissue engineering includes the construction of tissue-organ scaffold. The advantage of three-dimensional scaffolds over two-dimensional scaffolds is that they provide homeostasis for a longer time. The microbial community in Symbiotic culture of bacteria and yeast (SCOBY) can be a source for kombucha (kombu tea) production. In this study, it was aimed to investigate the usage of SCOBY, which produces bacterial cellulose, as a biomaterial and 3D scaffold material. 3D printable biomaterial was obtained by partial hydrolysis of oolong tea and black tea kombucha biofilms. In order to investigate the usage of 3D kombucha biomaterial as a tissue scaffold, "L929 cell line 3D cell culture" was created and cell viability was tested in the biomaterial. At the end of the 21st day, black tea showed 51% and oolong tea 73% viability. The cytotoxicity of the materials prepared by lyophilizing oolong and black tea kombucha beverages in fibroblast cell culture was determined. Black tea IC50 value: 7.53 mg, oolong tea IC50 value is found as 6.05 mg. Fibroblast viability in 3D biomaterial + lyophilized oolong and black tea kombucha beverages, which were created using the amounts determined to these values, were investigated by cell culture Fibroblasts in lyophilized and 3D biomaterial showed viability of 58% in black tea and 78% in oolong tea at the end of the 7th day. In SEM analysis, it was concluded that fibroblast cells created adhesion to the biomaterial. 3D biomaterial from kombucha mushroom culture can be used as tissue scaffold and biomaterial.Publication Open Access 3D printed microneedles for point of care biosensing applications(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Department of Mechanical Engineering; Sarabi, Misagh Rezapour; Nakhjavani, Sattar Akbar; Taşoğlu, Savaş; Faculty Member; Department of Mechanical Engineering; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); Koç Üniversitesi İş Bankası Yapay Zeka Uygulama ve Araştırma Merkezi (KUIS AI)/ Koç University İş Bank Artificial Intelligence Center (KUIS AI); Graduate School of Sciences and Engineering; College of Engineering; N/A; N/A; 291971Microneedles (MNs) are an emerging technology for user-friendly and minimally invasive injection, offering less pain and lower tissue damage in comparison to conventional needles. With their ability to extract body fluids, MNs are among the convenient candidates for developing biosensing setups, where target molecules/biomarkers are detected by the biosensor using the sample collected with the MNs. Herein, we discuss the 3D printing of microneedle arrays (MNAs) toward enabling point-of-care (POC) biosensing applications.Publication Metadata only 3D printed poly(lactic acid) scaffolds modified with chitosan and hydroxyapatite for bone repair applications(Elsevier, 2020) N/A; N/A; N/A; N/A; Department of Chemistry; Department of Chemical and Biological Engineering; Department of Chemistry; Nazeer, Muhammad Anwaar; Önder, Özgün Can; Sevgili, İlkem; Yılgör, Emel; Kavaklı, İbrahim Halil; Yılgör, İskender; PhD Student; PhD Student; PhD Student; Researcher; Faculty Member; Faculty Member; Department of Chemical and Biological Engineering; Department of Chemistry; 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; Graduate School of Sciences and Engineering; College of Sciences; College of Engineering; College of Sciences; N/A; N/A; N/A; N/A; 40319; 241813D printed poly(lactic acid) (PLA) scaffolds surface modified with chitosan (CS) and hydroxyapatite (HA) to produce a novel bioactive composite scaffold is reported. Excellent mechanical properties of PLA, the bioactivity of CS, and osteogenic characteristics of HA are combined to fabricate composite scaffolds using a simple desktop 3D printer. Scaffolds were characterized through attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) and water contact angle measurements before and after modification. Formic acid was used as a solvent to prepare stable CS/HA dispersions and was found to be a suitable solvent for producing PLA/CS/HA composites. Surface properties of modified scaffolds were superior in terms of hydrophilicity and bioactivity, which resulted in enhanced attachment and proliferation of human osteosarcoma cells in vitro compared to the unmodified PLA scaffolds.Publication Open Access A bacteria-derived tail anchor localizes to peroxisomes in yeast and mammalian cells(Nature Publishing Group (NPG), 2018) Seferoğlu, Ayşe Bengisu; Department of Molecular Biology and Genetics; Dunn, Cory David; Keskin, Abdurrahman; Akdoğan, Emel; Lutfullahoglu-Bal, Guleycan; Department of Molecular Biology and Genetics; College of SciencesProkaryotes can provide new genetic information to eukaryotes by horizontal gene transfer (HGT), and such transfers are likely to have been particularly consequential in the era of eukaryogenesis. Since eukaryotes are highly compartmentalized, it is worthwhile to consider the mechanisms by which newly transferred proteins might reach diverse organellar destinations. Toward this goal, we have focused our attention upon the behavior of bacteria-derived tail anchors (TAs) expressed in the eukaryote Saccharomyces cerevisiae. In this study, we report that a predicted membrane-associated domain of the Escherichia coli YgiM protein is specifically trafficked to peroxisomes in budding yeast, can be found at a pre-peroxisomal compartment (PPC) upon disruption of peroxisomal biogenesis, and can functionally replace an endogenous, peroxisome-directed TA. Furthermore, the YgiM(TA) can localize to peroxisomes in mammalian cells. Since the YgiM(TA) plays no endogenous role in peroxisomal function or assembly, this domain is likely to serve as an excellent tool allowing further illumination of the mechanisms by which TAs can travel to peroxisomes. Moreover, our findings emphasize the ease with which bacteria-derived sequences might target to organelles in eukaryotic cells following HGT, and we discuss the importance of flexible recognition of organelle targeting information during and after eukaryogenesis.Publication Open Access A comparative molecular dynamics study of methylation state specificity of JMJD2A(Public Library of Science, 2011) Bozfakioğlu S.; Uğurel, Elif; Sinan, M.; Department of Chemical and Biological Engineering; Keskin, Özlem; Erman, Burak; Gürsoy, Attila; Faculty Member; Faculty Member; Department of Chemical and Biological Engineering; College of Sciences; College of Engineering; 26605; 179997; N/AHistone modifications have great importance in epigenetic regulation. JMJD2A is a histone demethylase which is selective for di- and trimethyl forms of residues Lys9 and Lys36 of Histone 3 tail (H3K9 and H3K36). We present a molecular dynamics simulations of mono-, di- and trimethylated histone tails in complex with JMJD2A catalytic domain to gain insight into how JMJD2A discriminates between the methylation states of H3K9. The methyl groups are located at specific distances and orientations with respect to Fe(II) in methylammonium binding pocket. For the trimethyllysine the mechanism which provides the effectual orientation of methyl groups is the symmetry, whereas for the dimethyllysine case the determining factors are the interactions between methyllysine head and its environment and subsequently the restriction on angular motion. The occurrence frequency of methyl groups in a certain proximity of Fe(II) comes out as the explanation of the enzyme activity difference on di-and tri-methylated peptides. Energy analysis suggests that recognition is mostly driven by van der Waals and followed by Coulombic interactions in the enzyme-substrate interface. The number (mono, di or tri) and orientations of methyl groups and water molecules significantly affect the extent of van der Waals interaction strengths. Hydrogen bonding analysis suggests that the interaction between JMJD2A and its substrates mainly comes from main chain-side chain interactions. Binding free energy analysis points out Arg8 as an important residue forming an intra-substrate hydrogen bond with tri and dimethylated Lys9 of the H3 chain. Our study provides new insights into how JMJD2A discriminates between its substrates from both a structural and dynamical point of view.Publication Metadata only A comparison of piezosurgery with conventional techniques for internal osteotomy(Springer, 2017) Dogan, R.; N/A; Koçak, İlker; Gökler, Ozan; Doctor; Teaching Faculty; N/A; School of Medicine; Koç University Hospital; Koç University Hospital; N/A; 311179To compare conventional osteotomy with the piezosurgery medical device, in terms of postoperative edema, ecchymosis, pain, operation time, and mucosal integrity, in rhinoplasty patients. In this prospective study, 49 rhinoplasty patients were randomly divided into two groups according to osteotomy technique used, either conventional osteotomy or piezosurgery. For all patients, the total duration of the operation was recorded, and photographs were taken and scored for ecchymosis and edema on postoperative days 2, 4, and 7. In addition, pain level was evaluated on postoperative day 2, and mucosal integrity was assessed on day 4. All scoring and evaluation was conducted by a physician who was blinded to the osteotomy procedure. In the piezosurgery group, edema scores on postoperative day 2 and ecchymosis scores on postoperative days 2, 4, and 7 were significantly lower than in the conventional osteotomy group (p < 0.05). On postoperative day 2, the pain level was lower in the piezosurgery group than in the conventional osteotomy group (p < 0.05). In an endoscopic examination on postoperative day 4, while 24% of the patients in the conventional osteotomy group had mucosal damage, no such damage was observed in the piezosurgery group. When total operation duration was compared, there was no significant difference between the groups (p > 0.05). Piezosurgery is a safe osteotomy method, with less edema (in the early postoperative period) and ecchymosis compared with conventional osteotomy, as well as less pain, a similar operation duration, and no mucosal damage.Publication Metadata only A compassionate self is a true self? self-compassion promotes subjective authenticity(Sage, 2019) Zhang, Jia Wei; Chen, Serena; Shakur, Teodora K. Tomova; Chai, Wen Jia; Ramis, Tamilselvan; Shaban-Azad, Hadi; Razavi, Pooya; Nutankumar, Thingujam; Manukyan, Arpine; N/A; Bilgin, Begüm; Master Student; Graduate School of Social Sciences and Humanities; N/ATheory and research converge to suggest that authenticity predicts positive psychological adjustment. Given these benefits of authenticity, there is a surprising dearth of research on the factors that foster authenticity. Five studies help fill this gap by testing whether self-compassion promotes subjective authenticity. Study 1 found a positive association between trait self-compassion and authenticity. Study 2 demonstrated that on days when people felt more self-compassionate, they also felt more authentic. Study 3 discovered that people experimentally induced to be self-compassionate reported greater state authenticity relative to control participants. Studies 4 and 5 recruited samples from multiple cultures and used a cross-sectional and a longitudinal design, respectively, and found that self-compassion predicts greater authenticity through reduced fear of negative evaluation (Study 4) and heightened optimism (Study 5). Across studies, self-compassion's effects on authenticity could not be accounted for by self-esteem. Overall, the results suggest that self-compassion can help cultivate subjective authenticity.Publication Metadata only A construal level account of the impact of religion and god on prosociality(Sage, 2020) N/A; N/A; Department of Business Administration; Canlı, Zeynep Gürhan; Karataş, Mustafa; PhD Student; Faculty Member; Department of Business Administration; Graduate School of Business; College of Administrative Sciences and Economics; N/A; 16135This research shows that the two most prevalent religious constructs-God and religion-differentially impact cognition. Activating thoughts about God (vs. religion) induces a relatively more abstract (vs. concrete) mindset (Studies 1a-1c). Consequently, time donation intentions (Study 2) and actual monetary donations (Study 3) after a God (vs. religion) prime increase when people are presented an abstractly (vs. concretely) framed donation appeal. Similarly, people donate more money to distant (vs. close) donation targets, which are construed relatively abstractly (vs. concretely), when a religious speech activates predominantly God-specific (vs. religion-specific) thoughts (Study 4). These effects are mediated by "feeling right" under construal level fit (Study 3). Overall, this research significantly advances extant knowledge on religious cognition and past research on the link between religion and prosociality.