Kadir Demirci

Bio: Kadir Demirci is an academic researcher from Süleyman Demirel University. The author has contributed to research in topics: Beck Depression Inventory & Anxiety. The author has an hindex of 10, co-authored 38 publications receiving 1208 citations.

Relationship of smartphone use severity with sleep quality, depression, and anxiety in university students.

Abstract: Background and aims The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students. Methods In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh Sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale. Results The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and day...

Validity and Reliability of the Turkish Version of the Smartphone Addiction Scale in a Younger Population

Abstract: Objective: Smartphones have many features such as communication, internet, photography, multimedia and navigation, and are currently one of the most popular technological devices. Usage of smartphones has increased rapidly and this rapid increase has brought about addiction and problematic usage. To our knowledge, there is no scale, which can be used to assess addiction to smartphones in the Turkish population. The aim of this study was to adapt Turkish terminology and to assess the reliability and validity of the Turkish version of the Smartphone Addiction Scale. Methods: The sample was composed of 301 students studying at the Faculty of Medicine, Suleyman Demirel University, who used smartphones. In the study, in addition to the Smartphone Addiction Scale, an Information Form, the Internet Addiction Scale and the Problem Mobile Phone Use Scale were used as tools for collecting data. The scales were given to all attendees in mixed order and the Information Form was always given at the first stage. It took about 20 minutes to complete the scales. Test-retest application was made with 30 randomly selected students (with the help of nicknames) three weeks later. The factor structure of the scale was examined by factor analysis and the Varimax Rotation method. Internal consistency, split-half reliability and test-retest reliability analyses were conducted for the reliability analysis. Pearson correlation analysis was used to analyze criterion-related validity. Results: Factor analysis revealed a seven-factor structure and factor loadings of items that ranged from 0.349 to 0.824. The Cronbach’s alpha coefficient was founded to be 0.947 for the scale. Correlations between the Smartphone Addiction Scale-Turkish version and the other scales were statistically significant. The test-retest reliability was high (r=0.814). The Guttman Split-half coefficient was calculated to be 0.893 in the split-half reliability analysis. The average total scores for girls were significantly higher than those for boys (p=0.03). There was a non-significant negative correlation between age and scale total score (r=-0.086, p=0.13). Average scale scores were the highest in users who used smartphones for over 16 hours. Average scale scores were significantly higher in users who used smartphones for over 16 hours compared with users of smartphones for less than 4 hours (p=0.01). We recorded the highest scale score in the game category. We didn’t observe any statistical significance when comparing game scores with those of the internet (p=0.44) and social networking (p=0.98) categories. Additionally, total scores for gaming were significantly higher than those for voice calling (p=0.02), short text messaging (p=0.02) and other categories (p=0.04). Moreover, the participants who selected the answers ‘agree’ or ‘unsure’ as self-rating for smartphone addiction obtained significantly higher scores than the participants who answered ‘disagree’ (p=0.01). Conclusion: In this study, we found that the Turkish version of the Smartphone Addiction Scale is a reliable and valid measurement tool for the evaluation of smartphone addiction.

Effects of smartphone overuse on hand function, pinch strength, and the median nerve

Abstract: Introduction In this study we investigated the flexor pollicis longus (FPL) tendon and median nerve in smartphone users by ultrasonography to assess the effects of smartphone addiction on the clinical and functional status of the hands. Methods: One hundred two students were divided into 3 groups: non-users, and high or low smartphone users. Smartphone Addiction Scale (SAS) scores and grip and pinch strengths were recorded. Pain in thumb movement and rest and hand function were evaluated on the visual analog scale (VAS) and the Duruoz Hand Index (DHI), respectively. The cross-sectional areas (CSAs) of the median nerve and the FPL tendon were calculated bilaterally using ultrasonography. Results: Significantly higher median nerve CSAs were observed in the dominant hands of the high smartphone users than in the non-dominant hands (P < 0.001). SAS scores correlated with VAS pain for movement and rest, DHI scores, and pinch strength (P < 0.05; r = 0.345, 0.272, 0.245, and 0.281, respectively). Conclusions: Smartphone overuse enlarges the median nerve, causes pain in the thumb, and decreases pinch strength and hand functions. Muscle Nerve, 2015 Muscle Nerve 52: 183–188, 2015

The Protective Role of Selenium on Scopolamine-Induced Memory Impairment, Oxidative Stress, and Apoptosis in Aged Rats: The Involvement of TRPM2 and TRPV1 Channels

Abstract: Inhibition of Ca2+ entry into the hippocampus and dorsal root ganglion (DRG) through inhibition of N-methyl-D-aspartate (NMDA) receptor antagonist drugs is the current standard of care in neuronal diseases such as Alzheimer's disease, dementia, and peripheral pain. Oxidative stress activates Ca2+-permeable TRPM2 and TRPV1, and recent studies indicate that selenium (Se) is a potent TRPM2 and TRPV1 channel antagonist in the hippocampus and DRG. In this study, we investigated the neuroprotective properties of Se in primary hippocampal and DRG neuron cultures of aged rats when given alone or in combination with scopolamine (SCOP). Thirty-two aged (18-24 months old) rats were divided into four groups. The first and second groups received a placebo and SCOP (1 mg/kg/day), respectively. The third and fourth groups received intraperitoneal Se (1.5 mg/kg/ over day) and SCOP + Se, respectively. The hippocampal and DRG neurons also were stimulated in vitro with a TRPV1 channel agonist (capsaicin) and a TRPM2 channel agonist (cumene hydroperoxide). We found that Se was fully effective in reversing SCOP-induced TRPM2 and TRPV1 current densities as well as errors in working memory and reference memory. In addition, Se completely reduced SCOP-induced oxidative toxicity by modulating lipid peroxidation, reducing glutathione and glutathione peroxidase. The Se and SCOP + Se treatments also decreased poly (ADP-ribose) polymerase activity, intracellular free Ca2+ concentrations, apoptosis, and caspase 3, caspase 9, and mitochondrial membrane depolarization values in the hippocampus. In conclusion, the current study reports on the cellular level for SCOP and Se on the different endocytotoxic cascades for the first time. Notably, the research indicates that Se can result in remarkable neuroprotective and memory impairment effects in the hippocampal neurons of rats. Graphical abstract Possible molecular pathways of involvement of selenium (Se) in scopolamine (SCOP) induced apoptosis, oxidative stress, and calcium accumulation through TRPM2 and TRPV1 channels in the hippocampus neurons of aged rats. The TRPM2 channel is activated by ADP-ribose and oxidative stress, although it is inhibited by ACA. The TRPV1 channel is activated by oxidative stress and capsaicin, and it is blocked by capsazepine (CPZ). The beta-amyloid plaque induces oxidative stress in hippocampus. SCOP can result in augmented ROS release in hippocampal neurons, leading to Ca2+ uptake through TRPM2 and TRPV1 channels. Mitochondria were reported to accumulate Ca2+ provided that intracellular Ca2+ rises, thereby leading to the depolarization of mitochondrial membranes and release of apoptosis-inducing factors such as caspase 3 and caspase 9. Se reduced TRPM2 and TRPV1 channel activation through the modulation of aging oxidative reactions and Se-dependent glutathione peroxidase (GSH-Px) antioxidant pathways.

Selenium attenuates apoptosis, inflammation and oxidative stress in the blood and brain of aged rats with scopolamine-induced dementia.

Abstract: A potent antioxidant, selenium might modulate dementia-induced progression of brain and blood oxidative and apoptotic injuries. The present study explores whether selenium protects against experimental dementia (scopolamine, SCOP)-induced brain, and blood oxidative stress, apoptosis levels, and cytokine production in rats. Thirty-two rats were equally divided into four groups. The first group was used as an untreated control. The second group was treated with SCOP to induce dementia. The third and fourth groups received 1.5 mg/kg selenium (sodium selenite) and SCOP + selenium, respectively. Dementia was induced in the second and forth groups by intraperitoneal SCOP (1 mg/kg) administration. Brain, plasma, and erythrocyte lipid peroxidation levels as well as plasma TNF-α, interleukin (IL)-1β, and IL-4 levels were high in the SCOP group though they were low in selenium treatments. Selenium and selenium + SCOP treatments increased the lowered glutathione peroxidase activity, reduced glutathione, vitamins A and E concentrations in the brain, erythrocytes and plasma of the SCOP group. Apoptotic value expressions as active caspase-3, procaspase-9, and PARP were also increased by SCOP, while they were decreased by selenium and selenium + SCOP treatments. In conclusion, selenium induced protective effects against experimental dementia-induced brain, and blood oxidative injuries and apoptosis through regulation of cytokine production, vitamin E, glutathione concentrations, and glutathione peroxidase activity.

Relationship of smartphone use severity with sleep quality, depression, and anxiety in university students.

Abstract: Background and aims The usage of smartphones has increased rapidly in recent years, and this has brought about addiction. The aim of the current study was to investigate the relationship between smartphone use severity and sleep quality, depression, and anxiety in university students. Methods In total, 319 university students (203 females and 116 males; mean age = 20.5 ± 2.45) were included in the study. Participants were divided into the following three groups: a smartphone non-user group (n = 71, 22.3%), a low smartphone use group (n = 121, 37.9%), and a high smartphone use group (n = 127, 39.8%). All participants were evaluated using the Pittsburgh Sleep Quality Index, Beck Depression Inventory, Beck Anxiety Inventory; moreover, participants other than those in the smartphone non-user group were also assessed with the Smartphone Addiction Scale. Results The findings revealed that the Smartphone Addiction Scale scores of females were significantly higher than those of males. Depression, anxiety, and day...