PubMed İndeksli Yayınlar Koleksiyonu / PubMed Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/20.500.11779/1928

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Now showing 1 - 8 of 8
  • Article
    Longitudinal Norms of Frailty Measured by the Frailty Index: A Cross-National Comparison Using Data from the Survey of Health, Aging, and Retirement in Europe (SHARE)
    (Elsevier, 2026-06-01) Gutierrez, Angela; Supiyev, Adil; Muniz-Terrera, Graciela; Sevi, Baris; Massa, Fernando; Marroig, Alejandra
    Background: Frailty, a geriatric syndrome commonly used to identify vulnerable older adults, is a public health priority. However, the lack of cross-national comparisons of frailty trajectories and their distribution constrains current understanding of normative changes in frailty for residents across different countries. Objective: To derive longitudinal percentiles of frailty using a consistent cross-country approach. Design: Observational study using longitudinal data from the Survey of Health, Ageing and Retirement in Europe (SHARE) between 2004 and 2020. Setting: We fit the distribution of the FI by Generalized Additive Models for Location, Scale, and Shape (GAMLSS), assessed the role of sex (male/female), education (in years), and migration status (migrant/non-migrant), and estimated the longitudinal percentiles of frailty using a consistent cross-country approach for 16 countries. Participants: Individuals aged >= 65 years (N = 42,951) at study entry. Measurements: Frailty index (FI) based on the accumulation of deficits in 40 items. Results: The results show that education is protective against frailty in all countries (a decrease of 1.1 pp. in Switzerland to 5.7 pp. in Slovenia, all p < 0.001). In most countries, women are frailer than men and migrant individuals have higher levels of frailty than non-migrants. FI trajectories showed heterogeneity across countries. The quantiles for women and migrants suggest frailer trajectories than men and non-migrants respectively. Conclusions: Findings from this cross-national comparison provide a framework within which the longitudinal norms of frailty trajectories from different countries can be interpreted.
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Estimated Probabilities of Positive, Vs. Negative, Events Show Separable Correlations With Covid-19 Preventive Behaviours
    (Elsevier, 2022-06-01) Aksu, Ayça; Booth, Robert W.; Yavuz, Burak Baran; Peker, Müjde
    Research has associated optimism with better health-protective behaviours, but few studies have measured optimism or pessimism directly, by asking participants to estimate probabilities of events. We used these probability estimates to examine how optimism and/or pessimism relate to protecting oneself from COVID-19. When COVID-19 first reached Turkey, we asked a snowball sample of 494 Istanbul adults how much they engaged in various COVID-protective behaviours. They also estimated the probabilities of their catching COVID-19, and of other positive and negative events happening to them. Estimated probability of general positive events (optimism) correlated positively with officially-recommended helpful behaviours (e.g. wearing masks), but not with less-helpful behaviours (e.g. sharing ‘alternative’ COVID-related information online). Estimated probabilities of general negative events (pessimism), or of catching COVID, did not correlate significantly with helpful COVID-related behaviours; but they did correlate with psychopathological symptoms, as did less-helpful COVID-related behaviours. This shows important nuances can be revealed by measuring optimism and pessimism, as separate variables, using probability estimates.
  • Article
    Citation - WoS: 44
    Citation - Scopus: 49
    Population Density Index and Its Use for Distribution of Covid-19: a Case Study Using Turkish Data
    (Elsevier, 2021-02-01) Başer, Onur
    Since March 2020, many countries around the world have been experiencing a large outbreak of a novel coronavirus (2019-nCoV). Because there is a higher rate of contact between humans in cities with higher population weighted densities, Covid-19 spreads faster in these areas. In this study, we examined the relationship between population weighted density and the spread of Covid-19. Using data from Turkey, we calculated the elasticity of Covid-19 spread with respect to population weighted density to be 0.67 after controlling for other factors. In addition to the density, the proportion of people over 65, the per capita GDP, and the number of total health care workers in each city positively contributed to the case numbers, while education level and temperature had a negative effect. We suggested a policy measure on how to transfer health care workers from different areas to the areas with a possibility of wide spread.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 16
    Elastic Deformation of Soft Tissue-Mimicking Materials Using a Single Microbubble and Acoustic Radiation Force
    (Elsevier, 2020-12-01) Körük, Hasan; Bezer, James H.; J Rowlands, Christopher; Choi, James J.; Rowlands, Christopher J.
    Mechanical effects of microbubbles on tissues are central to many emerging ultrasound applications. Here, we investigated the acoustic radiation force a microbubble exerts on tissue at clinically relevant therapeutic ultrasound parameters. Individual microbubbles administered into a wall-less hydrogel channel (diameter: 25–100 µm, Young's modulus: 2–8.7 kPa) were exposed to an acoustic pulse (centre frequency: 1 MHz, pulse length: 10 ms, peak-rarefactional pressures: 0.6–1.0 MPa). Using high-speed microscopy, each microbubble was tracked as it pushed against the hydrogel wall. We found that a single microbubble can transiently deform a soft tissue-mimicking material by several micrometres, producing tissue loading–unloading curves that were similar to those produced using other indentation-based methods. Indentation depths were linked to gel stiffness. Using a mathematical model fitted to the deformation curves, we estimated the radiation force on each bubble (typically tens of nanonewtons) and the viscosity of the gels. These results provide insight into the forces exerted on tissues during ultrasound therapy and indicate a potential source of bio-effects.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 2
    Dataseton Maternal Attitudes About Child Maltreatment in Nine Countries Using a Q-Sort Methodology
    (Elsevier, 2020-06-01) Mels, Cindy; Alink, Lenneke; Branger, Marjolein; Carcamo, Rodrigo; Van Ginkel, Joost); Wang, Lamei; Yavuz Müren, Melis; Asanjarani, Faramarz; Soares, Isabel; Emmen, Rosanneke; Selcuk, Bilge; Hsiao, Celia; Woudstra, Mi-lan; Mesman, Judi
    Analyses of the present data are reported in the article "Crossing Boundaries: A Pilot Study of Maternal Attitudes about Child Maltreatment in Nine Countries"[8]. Data were collected during home visits using the Maltreatment Q-Sort (MQS). A total of 466 mothers from nine different countries gave their opinion about child maltreatment by sorting 90 cards with parenting behaviors taken from the literature that reflect four types of child maltreatment, into 9 evenly distributed stacks (with 10 cards each) from least to most harmful for the child. This data article provides an overview of the content of the 90 items, which type of maltreatment they reflect, and the source of the items. The percentage of mothers labelling each of the MQS items as maltreatment is also presented. In addition, instructions are included about the administration of the MQS as well as data-entry and analyses of Q-sort data, accompanied by example datasets and syntaxes. This can serve as a manual for researchers interested in using Q-sort data.
  • Article
    Citation - WoS: 25
    Citation - Scopus: 25
    Impact of Switching From an Initial Tumor Necrosis Factor Inhibitor on Health Care Resource Utilization and Costs Among Patients With Rheumatoid Arthritis
    (Elsevier, 2015-07-01) Roy, Sanjoy; Ganguli, Arijit; Xie, Lin; Başer, Onur; Cifaldi, Mary
    Purpose: Despite improved clinical outcomes for the majority of patients, nearly 30% of patients with rheumatoid arthritis (RA) who initiate tumor necrosis factor antagonist (anti-TNF) biologic agents fail to respond to their first-line anti-TNF and switch to another anti-TNF or a non-TNF biologic. How this change affects health care costs and resource utilization is unknown. We therefore compared RA patients taking first-line anti-TNFs who switched to a second anti-TNF versus those patients who switched to an alternate biologic. Methods: Health care claims data were obtained from a large US database for eligible adults with confirmed RA diagnoses who initiated anti-TNF treatment and switched to another biologic. Health care costs and utilization during the first 12 months' postswitch were compared. Generalized linear models were used to adjust for differences in demographic and clinical characteristics before switching. Findings: Patients who switched to a second anti-TNF rather than a non-TNF biologic were generally younger (53.0 vs. 55.3 years; P < 0.0001) and less likely to be female (79.7% vs. 82.7%; P = 0.0490). Of the 3497 eligible patients who switched from first-line anti-TNFs, 2563 (73.3%) switched to another anti-TNF and 934 (26.7%) switched to a non-TNF. Adalimumab was the most frequently prescribed (43.4%) second-line anti-TNF, and abatacept was the most common non anti-TNF (71.4%). Patients who switched to a second anti-TNF remained on their first medication for a significantly shorter period (342.5 vs 420.6 days; P < 0.0001) and had lower comorbidity indices and higher disease severity at baseline than those who switched to a non anti-TNF. After adjusting for baseline differences, patients who switched to second anti-TNFs versus a non-TNF incurred lower RA-related costs ($20,938.9 vs $22,645.2; P = 0.0010) and total health care costs ($34,894.6 vs $38,437.2; P = 0.0010) 1 year postswitch. These differences were driven by increased physician office visit costs among the non-TNF group. Implications: Among the anti-TNF initiators who switched therapy, more patients switched to a second anti-TNF than to a non-TNF. Switching to a second anti-TNF treatment was associated with lower all-cause and RA-related health care costs and resource utilization than switching to a non-TNF. Because switching therapy may be unavoidable, finding a treatment algorithm mitigating this increase to any extent should be considered. These data are limited by their retrospective design. Additional confounding variables that could not be controlled for may affect results. (C) 2015 The Authors. Published by Elsevier HS journals, Inc.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 17
    Acoustic Streaming in a Soft Tissue Microenvironment
    (Elsevier, 2019-01-01) El Ghamrawy, Ahmed; Mohammed, Ali; Jones, Julian R; Körük, Hasan; Choi, James J; de Comtes, Florentina
    We demonstrated that sound can push fluid through a tissue-mimicking material. Although acousticstreaming in tissue has been proposed as a mechanism for biomedical ultrasound applications, such as neuromodu-lation and enhanced drug penetration, streaming in tissue or acoustic phantoms has not been directly observed. Wedeveloped a material that mimics the porous structure of tissue and used a dye and a video camera to track fluidmovement. When applied above an acoustic intensity threshold, a continuous focused ultrasound beam (spatialpeak time average intensity: 238 W/cm2, centre frequency: 5 MHz) was found to push the dye axially, that is, in thedirection of wave propagation and in the radial direction. Dye clearance increased with ultrasound intensity andwas modelled using an adapted version of Eckart’s acoustic streaming velocity equation. No microstructuralchanges were observed in the sonicated region when assessed using scanning electron microscopy. Our study indi-cates that acoustic streaming can occur in soft porous materials and provides a mechanistic basis for future use ofstreaming for therapeutic or diagnostic purposes.
  • Article
    Citation - WoS: 1
    Citation - Scopus: 3
    Brief Time Course of Trait Anxiety-Related Attentional Bias To Fearconditioned Stimuli: Evidence From the Dual-Rsvp Task
    (Elsevier, 2017-03-01) Booth, Robert William
    Background and objectives Attentional bias to threat is a much-studied feature of anxiety; it is typically assessed using response time (RT) tasks such as the dot probe. Findings regarding the time course of attentional bias have been inconsistent, possibly because RT tasks are sensitive to processes downstream of attention. Methods Attentional bias was assessed using an accuracy-based task in which participants detected a single digit in two simultaneous rapid serial visual presentation (RSVP) streams of letters. Before the target, two coloured shapes were presented simultaneously, one in each RSVP stream; one shape had previously been associated with threat through Pavlovian fear conditioning. Attentional bias was indicated wherever participants identified targets in the threat’s RSVP stream more accurately than targets in the other RSVP stream. Results In 87 unselected undergraduates, trait anxiety only predicted attentional bias when the target was presented immediately following the shapes, i.e. 160 ms later; by 320 ms the bias had disappeared. This suggests attentional bias in anxiety can be extremely brief and transitory. Limitations This initial study utilised an analogue sample, and was unable to physiologically verify the efficacy of the conditioning. The next steps will be to verify these results in a sample of diagnosed anxious patients, and to use alternative threat stimuli. Conclusions The results of studies using response time to assess the time course of attentional bias may partially reflect later processes such as decision making and response preparation. This may limit the efficacy of therapies aiming to retrain attentional biases using response time tasks.