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Publication Open Access “Noise Factory”: a qualitative study exploring healthcare providers’ perceptions of noise in the intensive care unit(Elsevier, 2020) Güner, Perihan; Kebapçı, Ayda; Faculty Member; School of Nursing; 203808Objectives: this study aimed to explore healthcare providers’ perceptions of noise in the intensive care unit. Design: a qualitative exploratory study was conducted using group interviews. Setting: the setting comprised a total of 15 participants (five physicians and ten registered nurses) working in an 18-bed medical surgical intensive care unit at a teaching hospital in Istanbul, Turkey. Semi-structured questions were formulated and used in focus group interviews, after which the recorded interviews were transcribed by the researchers. Thematic analysis was used to identify significant statements and initial codes. Findings: four themes were identified: the meaning of noise, sources of noise, effects of noise and prevention and management of noise. It was found that noise was an inevitable feature of the intensive care unit. The most common sources of noise were human-induced. It was also determined that device-induced noise, such as alarms, did not produce a lot of noise; however, when staff were late in responding, the sound transformed into noise. Furthermore, it was observed that efforts to decrease noise levels taken by staff had only a momentary effect, changing nothing in the long term because the entire team failed to implement any initiatives consistently. The majority of nurses stated that they were now becoming insensitive to the noise due to the constant exposure to device-induced noise. Conclusion: the data obtained from this study showed that especially human-induced noise threatened healthcare providers’ cognitive task functions, concentration and job performance, impaired communication and negatively affected patient safety. In addition, it was determined that any precautions taken to reduce noise were not fully effective. A team approach should be used in managing noise in intensive care units with better awareness.
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 Open Access #COVID19 and #Breastcancer: a qualitative analysis of tweets(Multidisciplinary Digital Publishing Institute (MDPI), 2022) Naganathan, G.; Cleland, J.; Reel, E.; Cil, T.; Bilgen, İdil; School of MedicineRapid and efficient communication regarding quickly evolving medical information was paramount for healthcare providers and patients throughout the COVID-19 pandemic. Over the last several years, social media platforms such as Twitter have emerged as important tools for health promotion, virtual learning among healthcare providers, and patient support. We conducted a qualitative thematic content analysis on tweets using the hashtags #BreastSurgery, #BreastCancer, #BreastOncology, #Pandemic, and #COVID19. Advocacy organizations were the most frequent authors of tweets captured in this dataset, and most tweets came from the United States of America (64%). Seventy-three codes were generated from the data, and, through iterative, inductive analysis, three major themes were developed: patient hesitancy and vulnerability, increased efforts in knowledge sharing, and evolving best practices. We found that Twitter was an effective way to share evolving best practices, education, and collective experiences among key stakeholders. As Twitter is increasingly used as a tool for health promotion and knowledge translation, a better understanding of how key stakeholders engage with healthcare-related topics on the platform can help optimize the use of this powerful tool.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 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 2.3-μm Tm3+: YLF laser passively Q-switched with a Cr2+: ZnSe saturable absorber(Optical Soc Amer, 2017) N/A; N/A; Canbaz, Ferda; Yorulmaz, İsmail; Sennaroğlu, Alphan; PhD Student; PhD Student; Faculty Member; 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; College of Sciences; N/A; N/A; 23851We report, what is to our knowledge, the first passively Q-switched operation of a 2.3-mu m Tm3+ : YLF laser by using a Cr2+ : ZnSe saturable absorber. In the experiments, a tunable Ti3+ : sapphire laser was used to end pump the Tm3+ : YLF gain medium inside an x cavity. A Cr2+ : ZnSe saturable absorber was also included in the cavity to initiate passive Q switching. At all pump power levels above lasing threshold, passively Q-switched operation of the Tm3+ : YLF laser could be obtained at 2309 nm with pulse durations and repetition frequencies in the ranges of 1.21.4 mu s and 0.3-2.1 kHz, respectively. Analysis of power dependent repetition rate data further gave an estimated value of 3.1% for the round-trip saturable loss of the Cr2+ : ZnSe saturable absorber.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 Open Access 25-hydroxyvitamin D levels are low but not associated with disease activity in chronic spontaneous urticaria and depression(AEPress, 2020) Vurgun, Eren; Güntaş, Gürkan; Kocatürk Göncü, Özgür Emek; Memet, Bachar; Doctor; School of Medicine; Koç University Hospital; 217219; N/AAim: to evaluate vitamin D levels in patients with chronic spontaneous urticaria (CSU), depression and both of them, thus to fi nd out whether vitamin D may be a common causative factor of CSU and depression. Methods: thirty patients with CSU, 30 patients with depression, 30 patients with both CSU and depression and 30 healthy volunteers as control group were involved in the study. Serum 25-hydroxyvitamin D (25(OH) D) levels of these groups were measured and compared. Correlations between 25(OH)D levels and the activity of CSU and depression were analyzed. Results: healthy controls' 25(OH)D levels (17.2±8.8 ng/mL) were higher than patients with CSU (9.1±5.1 ng/mL), depression (8.9±6.1 ng/mL) and CSU with depression (7.7±4.7 ng/mL) (p<0.001, p<0.001 and p<0.001, respectively). There were no differences in 25(OH)D levels between CSU patients with and without depression, between depression patients and CSU patients with and without depression (p=0.43, p=0.82 and p=0.92, respectively). There were no correlations between 25(OH)D levels and the activity of CSU or depression (p=0.99 and p=0.76, respectively). Conclusion: Lower 25(OH)D levels in CSU and/or depression may appear as a secondary phenomenon, which means being result of these diseases rather than the cause (Tab. 1, Fig. 2, Ref. 41).