Cukurova University
  • Adana, Turkey
Recent publications
Introduction Lower limb stiffness has been shown to be associated with running economy (RE) in adults, but this relationship in children remains unclear. Objectives The purpose of this study was to investigate the relationship between lower limb stiffness, RE, and repeated-sprint ability in child soccer players. Methods Twenty-eight male child soccer players (mean age 11.8 ± 0.9 years) participated in the study. RE was determined by measuring the steady-state oxygen uptake (ml/min/kg) at submaximal running speeds of 8 and 9 km/h. Vertical and leg stiffness were calculated from the flight and contact time data obtained during two submaximal running tests. Additionally, vertical stiffness was measured during the maximal and submaximal hopping tests. All participants performed the repeated sprint test consisting of 10 × 20-m all-out sprints interspersed with 20-s active recovery. Results During both submaximal running tests, vertical (r= –0.505 to –0.472) and leg stiffness (r= –0.484 to –0.459) were significantly correlated with RE (p< 0.05). Maximal (r= –0.450) and submaximal hopping stiffness (r= –0.404) were significantly correlated with RE at 8 km/h (p< 0.05). Maximal hopping stiffness was significantly correlated with the best sprint time (r= –0.439) and mean sprint time (r= –0.496) (p< 0.05). Vertical (r= –0.592 to –0.433) and leg stiffness (r= –0.612 to –0.429) at 8 and 9 km/h and submaximal hopping stiffness (r= –0.394) were significantly correlated with the fatigue index (p< 0.05). Conclusions Current findings indicate that the lower limb stiffness may be an important determinant of both RE and repeated-sprint ability in child soccer players. Level of Evidence II; Diagnostic Studies - Investigating a Diagnostic Test. Oxygen consumption; Running; Children
“Food processing 4.0” concept denotes processing food in the current digital era by harnessing fourth industrial revolution (called Industry 4.0) technologies to improve quality and safety of processed food products, reduce production costs and time, save energy and resources, as well as diminish food loss and waste. Industry 4.0 technologies have been gaining great attention in recent years, revolutionizing, and transforming many manufacturing industries, including the food processing sector. The aim of this narrative review is to provide an updated overview of recent developments of Industry 4.0 technologies in digital transformation and process automation of the food processing industry. Our literature review shows the key role of robotics, smart sensors, Artificial Intelligence, the Internet of Things, and Big Data as the main enablers of the Food Processing 4.0. advantages in terms of quality control (sorting during processing with robotics and Artificial Intelligence, for instance), safety (connecting sensors and devices with Internet of Things), and production efficiency (forecasting demand with Big Data). However, detailed studies are still necessary to tackle significant challenges and provide deep insights into each of Food Processing 4.0 enablers such as the development of specific effectors for robotics; miniaturization and portability for sensors; standardization of systems and improve data sharing for Big Data; and reduce initial and maintenance costs of these technologies.
A series of novel N-benzoylthiourea-pyrrolidine carboxylic acid derivatives bearing an imidazole moiety has been prepared and their various biological activities are evaluated. The ability of forming intermolecular hydrogen-bonds of these molecules was pursued in the search of the best antimicrobial activity. The synthesized compounds were tested to search whether they had an enzyme inhibitory potency against AChE and BChE, which are the main targets for Alzheimer's disease. The prepared compounds were also screened for antituberculosis activity against M. tuberculosis H37Rv strain and the antibacterial activity against E. coli, A. baumannii, S. aureus, B. subtilis, A. hydrophila, bacteria. In addition, their antifungal activities are also evaluated against C. tropicalis, C. albicans, C. glabrata strains.
Improving thermal performance in heated channels has received much attention from many researchers due to its presence in various thermal systems. The present research numerically illustrated the effect of turbulent pulsating flow and SWCNT-water nanofluids in sinusoidal wavy channel on hydrothermal characteristics and entropy production. This study aims to provide a new thermal management approach for compact heat exchangers. Two various models for describing the motion of nanoparticles in a base fluid are applied. These models are Homogeneous single-phase, SPM and Lagrangian-Eulerian model (or discrete phase model), DPM. Governing equations are computationally solved utilizing the finite volume technique. This simulation covers Reynolds number, pulsation frequency, phase shift and nanoparticles concentration in the range of (4000 ≤ Re ≤ 7000), (1 ≤ f ≤ 5), (0° ≤ θ ≤ 180°) and (0% ≤ φ ≤ 3%), respectively. CFD simulations show that the pulsation frequency, f and phase shift, θ have a significant role in improving the heat transfer ratio and controlling the entropy generation through the wavy channel. Finally, it is recommended to use SWCNT/water nanofluid with a high-volume fraction (φ = 3%) as a working fluid in the considered channel due to its high heat transfer ratio and low thermal irreversibility.
The increasing demand for clean energy has resulted in the growth of renewable energy-based distributed generation (DG) penetration in the power distribution networks (PDN). The crucial point here is to find the optimum allocation of DGs to minimize the power loss and enhance the system performance overall. In this study, the Equilibrium Optimizer (EO) algorithm-based method is proposed to determine the location, size, connection type, and power factor of three different types of multiple DGs based on a three-phase 123-bus unbalanced PDN. The complex 123-bus UPDN has been very little studied to date, and most existing research works on the DG allocation problem have been conducted using a co-simulation platform. In this work, an unbalanced three-phase backward forward load flow (UBFLF) algorithm is written and executed under the MATLAB environment. This approach has decreased the complexity of co-simulation and provided advantages like optimizing the power factor value and the connection type (Delta/Wye) of DGs easily. Six more recent and well-established optimization algorithms such as PSO, JFO, BO, SMA, FDA, and GBO are also applied under the same test conditions to solve the Type-III DGs allocation problem. The results obtained are compared with the proposed method to show the effectiveness of the method in terms of elapsed time, statistical variables (such as standard deviation, median, variance and so on), converge speed, and best/worst case active power loss values. The efficacy of the presented method is also validated by comparing the results obtained using three distinct platforms as MATLAB/Simulink, IEEE-PES data, and OpenDSS. The detailed and comprehensive analyses show that the proposed approach demonstrates the lowest power loss, more enhancement in voltage profile, and the superiority of the EO algorithm in the application of a 123-bus unbalanced power distribution network.
The North Anatolian Fault Zone (NAFZ) is the world's most seismically significant strike-slip fault and Turkey's most active tectonic structure. A segment of NAFZ known as Gerede is located in northwest Turkey. It is debatable whether the Gerede segment of the NAFZ exhibits evidence of tectonic creep formation. The movement of the Gerede Segment of the NAFZ was investigated using various methods in this study. The Global Navigation Satellite System (GNSS) and soil mechanics-based methods were used in the Gerede Segment of the NAFZ for fault displacement analysis using a multidisciplinary approach. The GNSS technique is widely used in geodynamics-kinematics and cartography studies of earth crust movements, as well as in determining deformations during earthquake periods and as a source of data in defining geological and atmospheric phases. By establishing a GNSS network composed of regional or geodetic station points around the fault zone, it is possible to determine the deformations, velocities, and possible seismic slip rates of permanent GNSS stations on this network. The shear box test is used in soil mechanics to determine the shear strength parameters c and φ. A shear box test is performed to determine the pattern of fault movement (seismic or aseismic) and to determine the shear strength parameters (c, φ). An undisturbed block sample from a paleoseismology trench was used for a consolidated drained (CD) type shear box test. It was found that the fault movement near the Gerede Segment was not creeping. This study makes a new contribution to the debate on whether the Gerede Segment's movement pattern is creep or seismic.
In this study, an investigation is made on the ratio of cushion gas to working gas in the storage of hydrogen gas at different depths in underground salt caverns. For this purpose, hydrogen storage parameters are determined for six salt caverns of the same size and characteristics but different depths in the same salt dome area. A minimum gas pressure inside the caverns is required to avoid some adverse effects such as collapse and cracking due to the pressure drop that occurs during the withdrawal of the stored hydrogen gas. Since this pressure required for cavern safety is provided by the cushion gas left in the cavern, determining the cushion gas/working gas ratio has a key role in preserving the structure of the caverns and balancing the storage cost. Therefore, in addition to calculating the energy value of the hydrogen stored in the caverns, the optimum cushion gas/working gas ratios are determined by using some mathematical equations for six salt caverns with different vertical depths. According to the calculations, while the total volume of the stored hydrogen gas at a depth of 1000 m is approximately 76×10⁶ Nm³, 33.46% of it cannot be used as cushion gas. Likewise, while the total volume of the stored hydrogen gas at a depth of 1500 m is approximately 106.55×10⁶ Nm³, 34.29% of it cannot be used as cushion gas.
Water hardness affects metal uptake and toxicity in fish. Calcium is the most important ion determining water hardness. Fish are one of the most important food supplies for humans. Thus, Oreochromis niloticus were exposed to Cr⁶⁺, Ni²⁺, Zn²⁺ and Hg²⁺ in differing Ca²⁺ levels (30, 60 and 120 mg Ca²⁺/L) and subsequently serum biochemical parameters and muscle food quality were investigated. In acute experiments (3 days), fish were exposed to 30 µM of Cr⁶⁺, Ni²⁺ and Zn²⁺, and 0.3 µM of Hg²⁺, though they were exposed to 10 µM for Cr⁶⁺, Ni²⁺ and Zn⁺² and 0.03 µM for Hg²⁺ in chronic experiments (30 days). Data showed that there were significant (p < 0.05) alterations in the levels of glucose, alanine transaminase, aspartate transaminase, cholesterol and triglyceride in the serum, most alterations being at the lowest calcium level. Serum ion levels (Na⁺, K⁺, Ca²⁺⁾ also altered significantly, but only in chronic exposures. There were significant variations in the quality of muscle in both durations, as total protein, lipid and raw ash levels altered significantly (p < 0.05), though no significant change occurred in the water content of muscle tissue. This work demonstrated that metals affected the serum biochemistry and muscle food quality of Oreochromis niloticus, emphasizing the stress that fish could face in metal-contaminated waters.
This study aimed to find the effects of several mycorrhiza species on agronomic characteristics and nutrient uptake of various sweet sorghum genotypes under the semi-arid Mediterranean soil conditions. Four sweet sorghum genotypes were inoculated with three mycorrhiza species under greenhouse conditions. The plants were evaluated for growth parameters such as shoot height, root length, root morphology (root surface, root diameter and volume), shoot and root dry weight, uptake of macro and micro mineral nutrients, root colonisation and mycorrhizal dependency. Mycorrhizal species significantly improved growth and productivity of sorghum genotypes. Inoculation of Funneliformis mosseae, Claroideoglomus claroideum and Claroideoglomus etunicatum resulted in the highest shoot and total dry matter biomass production in Ashana, Hereahri and Yellow genotypes, respectively. Mycorrhiza inoculated white genotype had higher root colonisation and root development, and shoot P, K, Ca and Mg contents. Yellow genotypes produced significantly higher shoot and total dry weight and also were highly mycorrhiza dependent among the four genotypes. Compared to the control treatment mycorrhizal inoculation increased shoot Zn concentration but had non-consistent effects on shoot Cu, Fe and Mn contents. Conclusively, our findings confirmed that sweet sorghum genotypes responded selectively to arbuscular mycorrhizal fungi (AMF) colonisation for their growth parameters and nutrients uptake.
The aim of this study is to determine the tea and coffee consumption habits of individuals in Adana and İzmir and to identify how the new trends are effective in consumption patterns. Therefore, the research is based on a comparison of two cities with distinctive culinary culture. Questionnaire technique was used to collect the data. Surveys were administered to 806 people in Adana and İzmir, Turkey. The research shows that tea is preferred in Adana (63.3%), whereas participants in İzmir opt for coffee (53.4%). The ratio of tasting international regional coffees is higher in İzmir than in Adana. In both cities, black tea and Turkish coffee are among the most consumed drinks. Despite the increasing tendency of foreign beverages due to the impact of globalization, the local people kept their interest in tea and Turkish coffee drink which is a component of the national intangible cultural heritage of Turkey. It is recommended that foreign businesses should include these traditional drinks on the menu.
Background Cold storage of reared natural enemies is important in terms of planning the release time and quantity, eliminating unpredicted demand increases, and reducing production costs. However, the tolerance of reared natural enemies at low temperatures varies depending on the species and needs to be determined. Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) is one of the most important natural enemies used in biological control of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in greenhouses. Results In a laboratory study, longevity, parasitism capacity and functional response of E. mundus adults obtained from 8-days cold-stored red-eyed E . mundus pupae at 10 °C with 45 ± 5% RH conditions were determined. Mean longevity obtained from stored E . mundus pupae of female and male were 23.6 and 16.2 days, respectively. However, parasitism capacity was negatively affected so that the total mean number of immature B . tabaci parasitized by an E . mundus female obtained from cold-stored pupae (13.6) was statistically lower than that obtained from the colony (26.8) reared at room temperature. Adults obtained from both non-stored and stored E . mundus pupae exhibited a type II functional response to increasing host density. Although cold storage did not alter the type of functional response, it negatively affected the maximum attack rate ( α ) and handling time ( Th ) of the parasitoid. The lowest maximum attack rate (1.56) and highest handling time (0.059) were obtained for adults of cold-stored E . mundus pupae. Conclusions The results obtained may contribute to the augmentative biological control of B. tabaci in greenhouses.
The increasing penetration of renewable energy sources in the power system raises several challenges from the power quality and output power fluctuations point of view. However, the output power oscillations and power quality problems caused by the low order harmonic oscillations at the second-order frequency of the utility grid on the dc-link capacitor are emerging as major issues for the efficient operation of power converters. In this manner, a novel method based on modification in the control algorithm to alleviate the output power oscillation and reduce the output current total harmonic distortion is proposed. The proposed control approach seems as a promising solution for the satisfactory grid operation of renewable energy sources regarding not requiring any additional circuit and increment in the capacity of the dc-link capacitor. Moreover, mitigation of oscillations enhances the active power reference tracking capability of the controller that enables the overall efficiency improvement of the system. The performed case studies reveal that the overall efficiency rate of the system is increased by 1.3%. On the other hand, the output current harmonic distortion is decreased below 3% even under low power operating conditions. Also, the complexity level of the control algorithm is quite low for real-time implementation.
Purpose The International Nosocomial Infection Control Consortium (INICC) found a high mortality rate in ICUs of the Middle East (ME). Our goal was to identify mortality risk factor (RF) in ICUs of the ME. Materials From 08/01/2003 to 02/12/2022, we conducted a prospective cohort study in 236 ICUs of 77 hospitals in 44 cities in 10 countries of ME. We analyzed 16 independent variables using multiple logistic regression. Results 66,440 patients, hospitalized during 652,167 patient-days, and 13,974 died. We identified following mortality RF: Age (adjusted odds ratio (aOR):1.02;p < 0.0001) rising risk 2% yearly; length of stay (LOS) (aOR:1.02;p < 0.0001) rising the risk 2% per day; central line (CL)-days (aOR:1.01;p < 0.0001) rising risk 1% per day; mechanicalventilator (MV) utilization-ratio (aOR:14.51;p < 0.0001); CL-associated bloodstream infection (CLABSI) acquisition (aOR):1.49;p < 0.0001); ventilator-associated pneumonia (VAP) acquisition (aOR:1.50;p < 0.0001); female gender (OR:1.14;p < 0.0001); hospitalization at a public-hospital (OR:1.31;p < 0.0001); and medical-hospitalization (aOR:1.64;p < 0.0001). High-income countries showed lowest risk (aOR:0.59;p < 0.0001). Conclusion Some identified RF are unlikely to change, such as country income-level, facility ownership, hospitalization type, gender, and age. Some can be modified; LOS, CL-use, MV-use, CLABSI, VAP. So, to lower the mortality risk in ICUs, we recommend focusing on strategies to shorten the LOS, reduce CL and MV-utilization, and use evidence-based recommendations to prevent CLABSI and VAP.
In the present paper, flow characteristics of an Unmanned Underwater Vehicle (UUV) with a commonly used Myring profile were investigated numerically and experimentally using Computational Fluid Dynamics (CFD) and the Particle Image Velocimetry (PIV) technique under the influence of free surface. The 3-D and two-phase flow simulation generated using the Volume of Fluid (VOF) were carried out using the Large Eddy Simulation (LES) turbulence model for high accuracy in both near free-surface and almost uniform flow conditions. Due to the presence of the free-surface effect, dynamics and unsteady instantaneous flow characteristics such as force and moment coefficients, streamlines topology, and pressure values on the body surface along with vorticity structures were found to be very chaotic and have irregular motion in the wake while the followable variation trend of the time-averaged properties was obtained to show critical immersion ratio. The immersion ratios of 0.75≤ h/D≤3.50 were examined at Reynolds numbers Re = 2.0 × 10⁴ and 4.0 × 10⁴. Jet-like flow between the UUV body and the free surface of the water was detected at the immersion ratio of h/D = 0.75, which caused a substantial asymmetry in flow structures, resulting in highest drag and lift values. Increased surface disturbance at Re = 4.0 × 10⁴ caused air introduction into via jet-like flow in h/D = 0.75, which caused positive lift. Hydrodynamic coefficients and isosurfaces shown that the free-surface effect decreased significantly up to h/D = 1.50 at constant Reynolds numbers. Further investigation of time-averaged velocity components, streamlines, vorticity and turbulence statistics revealed that h/D = 1.50 acted as a transitional immersion ratio as the flow structure changed significantly with Reynolds numbers. The utilized CFD approach yielded especially excellent agreement with the PIV measurements with the discrepancy which varies from 1% to 15% in near wake for streamwise velocity components to simulate the essential unmeasured flow features needed in the research and development process of UUVs when they move below the free surface.
The aim of this study was to present the clinical and microbiological characteristics of patients with infective endocarditis.A retrospective evaluation was made of patients diagnosed with infective endocarditis between 1995 and 2021. The clinical and laboratory characteristics of the patients were recorded together with conditions constituting a risk for the development of endocarditis, treatment, and surgical outcomes.Evaluation was made of 68 patients with a mean age of 7.3 years (3 months-17 years), diagnosed with infective endocarditis. An underlying cause of CHD was determined in 47 (69%) patients and rheumatic valve disease in 3 (4.4%). There was no structural heart disease in 18 (26%) patients of whom 13 of them had other risk factors. A causative organism was found in 41 (60%) cases, and the microorganism most often determined was viridans group streptococcus. No difference was determined between the patients diagnosed before and after 2007 in respect of the frequency of viridans streptococcus (p > 0.05). Septic emboli were seen in 18 (26%) patients, of which 17 required surgical treatments. In 5 of 11 (16.6%) patients with mortality, the agent was S. aureus. Of the total 28 (41%) patients were evaluated as hospital-acquired endocarditis. The most frequently determined agents in this group were staphylococcus epidermidis and S. aureus.Although CHDs continue to be the greatest risk factor for endocarditis, there is an increasing frequency of endocarditis in patients with no structural heart disease. Mortality rates are still high in infective endocarditis, especially in S. aureus endocarditis.
Background: Sorafenib is a multikinase inhibitor currently used in the treatment of hepatocellular carcinoma, renal cell carcinoma and thyroid cancer. Objectives: The literature on this agent is scarce. This study aimed to evaluate the effects of sorafenib when administered to both healthy and cisplatin-induced rats. Material and methods: The animals were divided into 4 groups: 1) control group that received 0.9% saline intraperitoneally (C); 2) group administered a single dose (7 mg/kg) of cisplatin (Cis); 3) a group administered 20 mg/kg of sorafenib for 7 days (Sor); 4) group administered 20 mg/kg of sorafenib followed by 7 mg/kg of cisplatin for 7 days (Cis+Sor). All animals were sacrificed 7 days after the completion of their treatment arm, and serum and tissue samples were taken. Results: Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and interleukin 38 (IL-38) levels were increased in the Sor and Cis+Sor groups compared to the control group. When compared with the control group, serum urea, creatinine, kidney IL-1β, and tumor necrosis factor alpha (TNF-α) levels did not change in the Sor group. When compared to the Cis group, the levels of these parameters decreased in the Cis+Sor group. Conclusions: According to the data obtained, sorafenib caused liver toxicity when given to both healthy and cisplatin-induced rats. While sorafenib did not cause any significant changes in the kidneys when given to healthy rats, it had a healing effect in kidneys after stress induced by cisplatin.
In this study, a new compressible flow model for small orifice openings in pneumatic proportional directional control valves has been proposed. It is crucial to precisely control pneumatic valves over all control ranges; yet, conventional flow models fail around the closed position of the valve. The main deficit of the existing studies in the literature is to assume constant values for the parameters of the flow model over changing operating conditions. It has been demonstrated that these rough assumptions are insufficient in precisely predicting the mass flow rate, particularly for small orifice openings. An enhanced experimental setup has been introduced to improve the effectiveness of the proposed model. The cracking pressure ratio and parameters of the model have been identified with experimental method. In the proposed model, new empirical coefficients have been established after a thorough investigation of the impact of supply pressure on the flow behavior of the valve. Validation studies of the model in both the filling and exhausting states of the valve have been carried out at various supply pressures and orifice openings, yielding rather promising modeling performances. In validation tests, the real pressure and the pressure produced by new model have been compared, and good agreement has been achieved with 0.0039% absolute error. According to the findings, the proposed improved flow model can be selected in precision pneumatic control applications.
In this study, we aimed to evaluate possible toxic effects of thimerosal, aluminum and combination of thimerosal and aluminum in SH-SY5Y cells. Inhibitory concentrations were determined by MTT assay; reactive oxygen species (ROS) were determined by a fluorometric kit and antioxidant/oxidant parameters were measured by spectrophotometric kits. Nuclear factor erythroid 2-associated factor 2 (Nrf2), norepinephrine (NE), dopamine transporter (DAT) and dopamine beta β-hydroxylase (DBH) levels were measured by sandwich ELISA kits while 8-hydroxy deoxyguanosine (8-OHdG) and dopamine levels were determined by competitive ELISA kits. Thimerosal (1.15 μM) and aluminum (362 μM) were applied to cells at inhibitory concentrations 20 (IC 20 s) for 24 h. ROS increased significantly in cells aluminum- and aluminum+thimerosal-treated cells. Glutathione levels decreased in aluminum group while total antioxidant capacity and protein oxidation levels increased significantly in aluminum and aluminum+thimerosal groups. Lipid peroxidation increased significantly in groups treated with aluminum and aluminum+thimerosal. Nrf2 levels and DNA damage were significantly higher in all groups while dopamine levels significantly increased in cells treated with thimerosal and aluminum+thimerosal, DAT levels were found to be higher in all experimental groups compared to the control. These findings showed that both thimerosal and aluminum can change oxidant/antioxidant status, cause DNA damage, alter dopamine and DAT levels. Changes seen in cells treated with combined exposure to aluminum and thimerosal are more pronounced. Special care should be taken while vaccinating sensitive populations and safer alternatives for aluminum and thimerosal should used.
Variable selection approaches are often employed in high-dimensionality and multicollinearity problems. Since lasso selects variables by shrinking the coefficients, it has extensive use in many fields. On the other, we may sometime have extra information on the model. In this case, the extra information should be considered in the estimation procedure. In this paper, we propose a stochastic restricted lasso estimator in linear regression model which uses the extra information as stochastic linear restrictions. The estimator is a generalization of mixed estimator with L1 type penalization. We give the coordinate descent algorithm to estimate the coefficient vector of the stochastic restricted lasso method and propose method to estimate the tuning parameter. We conduct two real data analyses and simulation studies to compare the estimator with several methods including the ridge, lasso and stochastic restricted ridge. The real data analyses and simulation studies show that the new estimator enjoys the automatic variable selection property of the lasso while outperforms standard methods, achieving lower test mean squared error.
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3,313 members
Selda Çetin
  • Department of Physics
Sevgi Ozcan
  • Department of Family Medicine
Uner Tan
  • Department of Physiology
Gulsah Saydaoglu
  • Department of Biostatistics and Medical Informatics
Dilek Özcengiz
  • Department of Anesthesiology and Reanimation
01330, Adana, Turkey
Head of institution
Prof. Dr. Meryem Tuncel