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Publication Metadata only “Beware the young doctor and the old barber”: development and validation of a job age-type spectrum(Elsevier, 2021) Reeves, Michael Dennis; Fritzsche, Barbara Ann; Smith, Nicholas Anthony; Ng, Yin Lu; Department of Business Administration; Department of Business Administration; Marcus, Justin; Faculty Member; College of Administrative Sciences and Economics; 124653Taking a worker-centric approach, with evidence based on the experiences of working individuals, the current study examines the age-related stereotypes of jobs, the characteristics of age-stereotyped jobs, and the consequences of occupying them. In Study 1, we utilize samples of working adults from the US, Turkey, and Malaysia to establish validation evidence for a spectrum of 160 jobs (n = 123 raters per job). Study 1 findings indicate that entry-level jobs and jobs requiring manual labor or the use of technology are younger-typed, whereas senior level jobs and jobs requiring large investments in training or education are older-typed. The age-typing of jobs was found to be similar across countries for the vast majority of jobs. We then provide criterion validity evidence in Study 2, by testing the interactive effects of chronological age, job age-type, and sex on psychological age and perceived age and sex discrimination across samples of workers from these same three countries (n = 1469). Results upheld theoretical predictions based upon career timetables theory, prototype matching theory, and intersectional salience of ageism theory. The interactive effects of chronological age and job age-type were stronger for women than for men; the hypothesized patterns of effects were overall consistent for women but not for men.Item Metadata only “Do you feel like becoming a leader?” emotions and the likelihood of self-nomination for leadership(Elsevier Science Inc, 2023) 0000-0003-4784-334X; Shelia, Salome; Department of Psychology; Aycan, Zeynep; Faculty Member; College of Social Sciences and Humanities; 5798Item Metadata only "Sensing" productivity at home: self-tracking technologies, gender, and labor in Turkey(Oxford Univ Press Inc, 2023) 0000-0001-7085-5934; Department of Media and Visual Arts; Ünal, Nazlı Özkan; Faculty Member; College of Social Sciences and Humanities; 309365This article explores how women in Turkey use sensing technologies to render visible their productivity at home in ways that contest home-workplace boundary under neoliberal, digital capitalism. It does so by focusing on a group of lower- and middle-class women, who work from home as both paid laborers and unpaid caregivers. Although neoliberalism makes it harder to distinguish home and workplace, my digital ethnography highlights that women working from home feel a home-workplace separation that renders invisible their productivity. By translating embodied knowledge into quantified data, smartwatches provide women with new information that I call revelations. Women share these revelations on digital platforms to render visible their productivity at home in ways that transgress the home-workplace boundary. By exploring these revelations as moments of "otherwise," this article highlights both when smartwatches reproduce neoliberal mentality and become tools for others in the public to register its exploitative consequences.Publication Metadata only “Smart poisoning” of Co/SiO2 catalysts by sulfidation for chirality-selective synthesis of (9,8) single-walled carbon nanotubes(2016) Yuan, Yang; Karahan, H. Enis; Wei, Li; Zhai, Shengli; Lau, Raymond; Chen, Yuan; N/A; Yıldırım, Cansu; Birer, Özgür; Master Student; Researcher; Koç University Surface Science and Technology Center (KUYTAM) / Koç Üniversitesi Yüzey Teknolojileri Araştırmaları Merkezi (KUYTAM); N/A; N/A; N/AThe chirality-selective synthesis of relatively large (diameter > 1 nm) single-walled carbon nanotubes (SWCNTs) is of great interest for a variety of practical applications, but only a few catalysts are available so far. Previous studies suggested that S (compounds) can enhance the chirality-selectivity of Co catalysts in SWCNT synthesis, however, the mechanism behind is not fully understood, and no tailorable methodology has yet been developed. Here, we demonstrate a facile approach to achieve the chirality-selective synthesis of SWCNTs by the sulfidation-based poisoning of silica-supported Co catalysts using a mixture of H2S and H2. The UV-vis-NIR, photoluminescence, and Raman spectroscopy results together show that the resulting SWCNTs have a narrow diameter distribution of around 1.2 nm, and (9,8) nanotubes have an abundance of ∼38% among the semiconducting species. More importantly, the carbon yield achieved by the sulfided catalyst (2.5 wt%) is similar to that of the nonsulfided one (2.7 wt%). The characterization of the catalysts by X-ray diffraction, X-ray photoelectron spectroscopy, X-ray fluorescence, and H2 temperature-programmed reduction shows that the sulfidation leads to the formation of Co9S8 nanoparticles. However, Co9S8 nanoparticles are reduced back to regenerate metallic Co nanoparticles during the synthesis of SWCNTs, which maintain a high carbon yield. In this process, Co9S8 nanoparticles seemingly intermediate the production of Co nanoparticles with narrow size distribution. Due to the fact that the poisoning step improves the quality of the end-product rather than hampering the growth process, we have coined the process developed as “smart poisoning”. This study not only reveals the mechanism behind the beneficial role of S in the selective synthesis of relatively large SWCNTs but also presents a promising method to create chirality-selective catalysts with high activity for scalable synthesis.Publication Open Access "Whole" vs "fragmented" approach to EAACI pollen season definitions: a multicenter study in six Southern European cities(Wiley, 2020) Hoffmann, Tara Maria; Şahin, Aydan Acar; Aggelidis, Xenophon; Arasi, Stefania; Barbalace, Andrea; Bourgoin, Anne; Bregu, Blerina; Brighetti, Maria Antonia; Caeiro, Elsa; Sozmen, Sule Caglayan; Caminiti, Lucia; Charpin, Denis; Couto, Mariana; Delgado, Luis; Businco, Andrea Di Rienzo; Dimier, Claire; Dimou, Maria, V; Fonseca, Joao A.; Göksel, Özlem; Güvensen, Aykut; Hernandez, Dolores; Jang, Dah Tay; Kalpaklıoğlu, Füsun; Lame, Blerta; Llusar, Ruth; Makris, Michael P.; Mazon, Angel; Mesonjesi, Eris; Nieto, Antonio; Pahus, Laurie; Pajno, Giovanni Battista; Panasiti, Ilenia; Panetta, Valentina; Papadopoulos, Nikolaos G.; Pellegrini, Elisabetta; Pelosi, Simone; Pereira, Ana Margarida; Pereira, Mariana; Pinar, Munevver; Pfaar, Oliver; Potapova, Ekaterina; Priftanji, Alfred; Psarros, Fotis; Sfika, Ifigenia; Suarez, Javier; Thibaudon, Michel; Travaglini, Alessandro; Tripodi, Salvatore; Verdier, Valentine; Villella, Valeria; Xepapadaki, Paraskevi; Matricardi, Paolo M.; Dramburg, Stephanie; Öztürk, Ayşe Bilge; Saçkesen, Cansın; Yazıcı, Duygu; Faculty Member; Faculty Member; PhD Student; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; Graduate School of Health Sciences; Koç University Hospital; 147629; 182537; N/ABackground: the adequate definition of pollen seasons is essential to facilitate a correct diagnosis, treatment choice, and outcome assessment in patients with seasonal allergic rhinitis. A position paper by the European Academy of Allergy and Clinical Immunology (EAACI) proposed season definitions for Northern and Middle Europe. Objective To test the pollen season definitions proposed by EAACI in six Mediterranean cities for seven pollen taxa. Methods: as part of the @IT.2020 multi-center study, pollen counts for Poaceae, Oleaceae, Fagales, Cupressaceae, Urticaceae (Parietaria spp.), and Compositae (Ambrosia spp., Artemisia spp.) were collected from January 1 to December 31, 2018. Based on these data, pollen seasons were identified according to EAACI criteria. A unified monitoring period for patients in AIT trials was created and assessed for feasibility. Results: the analysis revealed a great heterogeneity between the different locations in terms of pattern and length of the examined pollen seasons. Further, we found a fragmentation of pollen seasons in several segments (max. 8) separated by periods of low pollen counts (intercurrent periods). Potential monitoring periods included often many recording days with low pollen exposure (max. 341 days). Conclusion: the Mediterranean climate leads to challenging pollen exposure times. Monitoring periods for AIT trials based on existing definitions may include many intermittent days with low pollen concentrations. Therefore, it is necessary to find an adapted pollen season definition as individual solution for each pollen and geographical area.Publication Metadata only (Bis)phosphonic acid-functionalized poly(ethyleneimine)- poly(amido amine)s for selective in vitro transfection of osteosarcoma cells(Amer Chemical Soc, 2021) Güven, Melek Naz; Altuncu, Seçkin; Konca, Yeliz Utku; Avcı, Duygu; N/A; Department of Chemistry; Department of Chemistry; Demirci, Gözde; Acar, Havva Funda Yağcı; Master Student; Faculty Member; Graduate School of Sciences and Engineering; College of Sciences; N/A; 178902Osteosarcoma is aggressive bone cancer, whose treatment has not changed significantly for the past few decades. Although gene therapy methods have emerged as potential treatment routes, the need for efficient and nontoxic gene delivery systems targeting osteosarcoma cells remains a challenge. High-molecular-weight poly(ethyleneimine)s (PEIs) are used as universal transfection agents; however, they cause significant cytotoxicity. on the other hand, poly(amido amine)s (PAAs) are biocompatible, biodegradable polymers with promising transfection efficiency, which should be improved further. In this paper, we combined low-molecular-weight branched PEI (1800 Da) and PAA macromers functionalized with various amounts of (bis)phosphonic acid groups and pentanol (via 5-amino-1-pentanol (AP)). The (bis)phosphonic acid groups on these polymers (PAEIs) are intended to facilitate bone targeting. The molecular weights of the PAEI polymers were between 2600 and 8600 g/mol. Their cytotoxicities and green fluorescence protein (GFP) transfection efficiencies were tested on an osteosarcoma cell line (U-2 OS cells), which is challenging to transfect, and healthy muscle cells (C2C12). Both the cytotoxicity and transfection efficiency of PAEIs were affected by the phosphonic acid (via APA, 2-aminoethyl phosphonic acid) or bisphosphonic acid (via ALE, sodium alendronate) content of the polymers. PAEIs are more cytocompatible than both linear and branched 25 kDa PEI. ALE-containing PAEIs provided better transfection than APA-containing ones. The most efficient PAEI polymer, containing a 0.7:0.3 AP/ALE ratio, displayed a transfection efficiency that was five times higher than that of 25 kDa PEI with dramatically better cytocompatibility. This is comparable to FuGENE, but PAEI is more advantageous in selective transfection of the U-2 OS. This set of polymers may be promising candidates for targeted gene therapy of osteosarcoma.Publication Metadata only 1,3-bis(gamma-aminopropyl)tetramethyldisiloxane modified epoxy resins: curing and characterization(Elsevier, 1998) Department of Chemistry; Department of Chemistry; Department of Chemistry; Yılgör, Emel; Yılgör, İskender; Researcher; Faculty Member; 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 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.Item Metadata only 3D bioprinted organ-on-chips(John Wiley and Sons Inc, 2023) 0000-0003-4604-217X; 0009-0004-1518-6706; 0000-0002-5295-5701; 0000-0001-8888-6106; Mustafaoglu, Nur; Zhang, Yu Shrike; Department of Electrical and Electronics Engineering; N/A; N/A; N/A; Taşoğlu, Savaş; Birtek, Mehmet Tuğrul; Sarabi, Misagh Rezapour; Dabbagh, Sajjad Rahmani; Faculty Member; PhD Student; PhD Student; PhD Student; Koç Üniversitesi İş Bankası Yapay Zeka Uygulama ve Araştırma Merkezi (KUIS AI)/ Koç University İş Bank Artificial Intelligence Center (KUIS AI); KU Arçelik Research Center for Creative Industries (KUAR) / KU Arçelik Yaratıcı Endüstriler Uygulama ve Araştırma Merkezi (KUAR); College of Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; 291971; N/A; N/A; N/AOrgan-on-a-chip (OOC) platforms recapitulate human in vivo-like conditions more realistically compared to many animal models and conventional two-dimensional cell cultures. OOC setups benefit from continuous perfusion of cell cultures through microfluidic channels, which promotes cell viability and activities. Moreover, microfluidic chips allow the integration of biosensors for real-time monitoring and analysis of cell interactions and responses to administered drugs. Three-dimensional (3D) bioprinting enables the fabrication of multicell OOC platforms with sophisticated 3D structures that more closely mimic human tissues. 3D-bioprinted OOC platforms are promising tools for understanding the functions of organs, disruptive influences of diseases on organ functionality, and screening the efficacy as well as toxicity of drugs on organs. Here, common 3D bioprinting techniques, advantages, and limitations of each method are reviewed. Additionally, recent advances, applications, and potentials of 3D-bioprinted OOC platforms for emulating various human organs are presented. Last, current challenges and future perspectives of OOC platforms are discussed. © 2022 The Authors. Aggregate published by SCUT, AIEI, and John Wiley & Sons Australia, Ltd.Publication Open Access 3D microprinting of iron platinum nanoparticle-based magnetic mobile microrobots(Wiley, 2021) Giltinan, Joshua; Sridhar, Varun; Bozüyük, Uğur; Sheehan, Devin; Department of Mechanical Engineering; Department of Mechanical Engineering; Sitti, Metin; Faculty Member; School of Medicine; College of Engineering; 297104Wireless magnetic microrobots are envisioned to revolutionize minimally invasive medicine. While many promising medical magnetic microrobots are proposed, the ones using hard magnetic materials are not mostly biocompatible, and the ones using biocompatible soft magnetic nanoparticles are magnetically very weak and, therefore, difficult to actuate. Thus, biocompatible hard magnetic micro/nanomaterials are essential toward easy-to-actuate and clinically viable 3D medical microrobots. To fill such crucial gap, this study proposes ferromagnetic and biocompatible iron platinum (FePt) nanoparticle-based 3D microprinting of microrobots using the two-photon polymerization technique. A modified one-pot synthesis method is presented for producing FePt nanoparticles in large volumes and 3D printing of helical microswimmers made from biocompatible trimethylolpropane ethoxylate triacrylate (PETA) polymer with embedded FePt nanoparticles. The 30 mu m long helical magnetic microswimmers are able to swim at speeds of over five body lengths per second at 200Hz, making them the fastest helical swimmer in the tens of micrometer length scale at the corresponding low-magnitude actuation fields of 5-10mT. It is also experimentally in vitro verified that the synthesized FePt nanoparticles are biocompatible. Thus, such 3D-printed microrobots are biocompatible and easy to actuate toward creating clinically viable future medical microrobots.