PubMed İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12469/4466

Browse

Now showing 1 - 5 of 5

Citation - WoS: 85
Citation - Scopus: 89
Electrical and Optical Percolations of Polystyrene Latex-Multiwalled Carbon Nanotube Composites
(Academic Press Inc Elsevier Science, 2010) Kara, Selim; Arda, Ertan; Dolastir, Fahrettin; Pekcan, Önder
Electrical conductivity and optical transmittance properties of polystyrene (PS)-multiwalled carbon nanotube (MWCNT) composite films were investigated. Composite films were prepared by mixing of various mass fractions of MWCNT in PS-water dispersions. After water evaporates powder composite films were annealed at 175 degrees C above the glass transition of PS for 20 min. Photon transmission and two point probe resistivity techniques were employed to determine the variations of the optical and the electrical properties of composites. Transmitted light intensity I(tr) and surface resistivity R(s) were monitored as a function of MWCNT mass fraction (M). It was observed that both the surface resistivity and the optical transparency were decreased by increasing the amount of MWCNT added to the polymeric system. Conductivity and optical results were interpreted according to the classical and site percolation theory respectively. The electrical (sigma) and the optical (op) percolation threshold values and critical exponents were calculated as M(sigma) = 1.8 wt.% M(op) = 0-0.13 wt.% and beta(sigma) = 2.25 beta(op) = 0.32 respectively. (C) 2010 Elsevier Inc. All rights reserved.
Citation - WoS: 20
Citation - Scopus: 21
How People Can Become Persuaded by Weak Messages Presented by Credible Communicators: Not All Sleeper Effects Are Created Equal
(Academic Press Inc Elsevier Science, 2017) Albarracin, Dolores; Kumkale, Gökçe Tarcan; Vento, Patrick Poyner-Del
The sleeper effect has been proposed to describe temporal changes in persuasion for messages associated with noncredible sources. The present research introduces a new kind of sleeper effect denoting increases in persuasion for weak messages associated with credible sources. This effect of the source was hypothesized to derive from attending to the message source rather than the message arguments and reconstructing delayed attitudes primarily on the basis of the source information. Findings from three experiments revealed that when the focus of attention was the communicator there was a sleeper effect for the source. Specifically during the time between an immediate follow up and a delayed follow up persuasion increased when credible sources presented weak arguments. In contrast when the focus of attention was the message arguments a traditional sleeper effect emerged. That is persuasion increased when strong arguments were presented by a noncredible communicator. These effects were mediated by relative recall of arguments versus source attributes and replicated with different message topics and lengths of delay. (C) 2016 Published by Elsevier Inc.
Investigation of Novel Nimesulide Derivatives Against Breast Cancer
(Academic Press Inc Elsevier Science, 2025) Birgul, Kaan; Atlihan, Irem; Dere, Damla; Yelekci, Kemal; Tiber, Pinar Mega; Orun, Oya; Kucukguzel, S. Guniz
This study focused on the synthesis of novel nimesulide semicarbazone derivatives and the evaluation of their cytotoxic potential against luminal-A (MCF-7) and triple-negative (MDA-MB-231) breast cancer cell lines. Additionally, their effects on mitochondrial membrane potential (MMP), apoptosis, and mitogen-activated protein kinase (MAPK) pathway modulation were investigated. Breast cancer remains the most prevalent malignancy among women, with luminal-A and triple-negative subtypes posing significant therapeutic challenges due to drug resistance and the lack of effective targeted treatments. The MAPK pathway plays a crucial role in breast cancer progression, making its inhibition a promising therapeutic approach. Non-steroidal anti-inflammatory drugs (NSAIDs), particularly nimesulide, have demonstrated anticancer potential beyond their well-established anti-inflammatory properties. Accordingly, the semicarbazone moiety was incorporated into the molecular scaffold to enhance the antiproliferative efficacy of nimesulide derivatives, as it has been reported to exhibit cytotoxic and apoptosis-inducing effects across various cancer cell lines. A series of nimesulide semicarbazone derivatives (5a-m) were synthesized through multi-step reactions and characterized using elemental analysis, FT-IR, 1H NMR, 13C NMR and Mass spectroscopy (5e). In silico studies were performed to predict their binding affinities to MAPK12. The cytotoxic effects of the synthesized compounds were assessed by determining IC50 values in MCF-7 and MDA-MB-231 cell lines (CCK8 test). Compounds exhibiting strong cytotoxic activity were further examined for their impact on MMP depolarization (JC-1 assay), apoptosis induction (Annexin V-FITC/PI staining), and MAPK pathway modulation (Western blotting of p-ERK and ERK protein). Molecular docking results indicated that the synthesized compounds exhibited favorable interactions with MAPK12, with compound 5e showing one of the highest binding affinity (-9.29 kcal/mol, Ki = 0.154 mu M). Cytotoxicity assays revealed that compound 5e had the lowest IC50 values (11.77 +/- 0.26 mu M in MCF-7; 20.72 +/- 0.25 mu M in MDA-MB-231), demonstrating significantly higher cytotoxicity than nimesulide. JC-1 assays confirmed that compound 5e induced MMP depolarization at higher concentrations, suggesting apoptosis activation. Flow cytometry analysis further validated a substantial increase in apoptotic cell populations following treatment with compound 5e. Western blot results showed a dose-dependent decrease in p-ERK levels in both MCF-7 and MDA-MB-231 cells, confirming MAPK pathway inhibition. These findings support that nimesulide-based semicarbazones, particularly compound 5e, exhibit potent antiproliferative and pro-apoptotic activity via MAPK pathway modulation, offering a promising avenue for the development of targeted breast cancer therapies.
Citation - WoS: 22
Citation - Scopus: 25
Secondhand Smoke in Waterpipe Tobacco Venues in Istanbul Moscow and Cairo
(Academic Press Inc Elsevier Science, 2019) Moon, Katherine A.; Magid, Hoda; Torrey, Christine; Rule, Ana M.; Ferguson, Jacqueline; Susan, Jolie; Sun, Zhuolu; Abubaker, Salahaddin; Levshin, Vladimir; Çarkoğlu, Aslı; Radwan, Ghada Nasr; El-Rabbat, Maha; Cohen, Joanna E.; Strickland, Paul; Navas-Acien, Ana; Breysse, Patrick N.
Objective: The prevalence of waterpipe tobacco smoking has risen in recent decades. Controlled studies suggest that waterpipe secondhand smoke (SHS) contains similar or greater quantities of toxicants than cigarette SHS which causes significant morbidity and mortality. Few studies have examined SHS from waterpipe tobacco in real-world settings. The purpose of this study was to quantify SHS exposure levels and describe the characteristics of waterpipe tobacco venues. Methods: In 2012-2014 we conducted cross-sectional surveys of 46 waterpipe tobacco venues (9 in Istanbul 17 in Moscow and 20 in Cairo). We administered venue questionnaires conducted venue observations and sampled indoor air particulate matter (PM2.5) (N=35) carbon monoxide (CO) (N=23) particle-bound polycyclic aromatic hydrocarbons (p-PAHs) (N=31) 4-methylnitrosamino)-1-(3-pyridy1)-1-butanone (NNK) (N-43) and air nicotine (N=46). Results: Venue characteristics and SHS concentrations were highly variable within and between cities. Overall we observed a mean (standard deviation (SD)) of 5 (5) waterpipe smokers and 5 (3) cigarette smokers per venue. The overall median (25th percentile 75th percentile) of venue mean air concentrations was 136 (82 213) mu/m(3) for PM2.5 3.9 (1.7 22) ppm for CO 68 (33 121) ng/m(3) for p-PAHs 1.0 (0.5 1.9) ng/m(3) for NNK and 5.3 (0.7 14) mu g/m(3) for nicotine. PM2.5 CO and p-PAHs concentrations were generally higher in venues with more waterpipe smokers and cigarette smokers although associations were not statistically significant. Conclusion: High concentrations of SHS constituents known to cause health effects indicate that indoor air quality in waterpipe tobacco venues may adversely affect the health of employees and customers. (C) 2015 Elsevier Inc. All rights reserved.
Citation - WoS: 9
Citation - Scopus: 9
Smoke-Free Turkey: Evaluation of Outdoor Areas of Public Places
(Academic Press Inc Elsevier Science, 2019) Kaplan, Bekir; Grau-Perez, Maria; Çarkoğlu, Aslı; Ergör, Gül; Hayran, Mutlu; Navas-Acien, Ana; Cohen, Joanna E.
Significance: Secondhand tobacco smoke (SHS) exposure is a major cause of morbidity and mortality around the world. The objective of this study was to evaluate the presence of smoking in outdoor areas of public places in three largest Turkish cities (Istanbul Ankara and Izmir). Method: For this cross-sectional observational study the Turkish Statistical Institute randomly selected 10 sampling points in each city. Around each sampling point fieldworkers visited the closest bars/nightclubs cafes government buildings hospitals restaurants schools shopping malls traditional coffee houses universities children's playgrounds parks and open markets. We observed smoking ashtrays and cigarette butts at the outdoor areas of public venues within the urban districts of each city. The fieldwork was conducted in April–May 2016. Results: 477 venues were observed covering 1017 outdoor locations in which 17737 people were observed. Smoking in outdoor areas ranged from 3.7% around schools to 90% in open markets. Ashtrays were almost ubiquitous in hospitals (95.6%) shopping malls (92.0%) and universities (90.9%). Cigarette butts were more often observed in open markets (100%) shopping malls (96%) universities (95.5%) and parks (93.3%). Smoking at outdoor areas around schools was significantly lower than around other venues. Conclusion: Smoking in outdoor areas was common in most public places in Turkey except schools. The current indoor SHS legislation should be extended to cover adjacent outdoor areas of public venues in order to effectively protect people from SHS exposure in Turkey. © 2019 The Authors

Browse

Browsing PubMed İndeksli Yayınlar Koleksiyonu by browse.metadata.publisher "Academic Press Inc Elsevier Science"