Drug—target network

Yıldırım, Muhammed A,Goh, Kwang-Il,Cusick, Michael E,Barabá,si, Albert-Lá,szló,Vidal, Marc Nature Pub. Co 2007 Nature biotechnology Vol.25 No.10

The global set of relationships between protein targets of all drugs and all disease-gene products in the human protein–protein interaction or 'interactome' network remains uncharacterized. We built a bipartite graph composed of US Food and Drug Administration–approved drugs and proteins linked by drug–target binary associations. The resulting network connects most drugs into a highly interlinked giant component, with strong local clustering of drugs of similar types according to Anatomical Therapeutic Chemical classification. Topological analyses of this network quantitatively showed an overabundance of 'follow-on' drugs, that is, drugs that target already targeted proteins. By including drugs currently under investigation, we identified a trend toward more functionally diverse targets improving polypharmacology. To analyze the relationships between drug targets and disease-gene products, we measured the shortest distance between both sets of proteins in current models of the human interactome network. Significant differences in distance were found between etiological and palliative drugs. A recent trend toward more rational drug design was observed.

A QP Artificial Neural Network Inverse Kinematic Solution for Accurate Robot Path Control

Sahin Yıldırım,Ikhal Eski 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.7

In recent decades, Artificial Neural Networks (ANNs) have become the focus of considerable attention in many disciplines, including robot control, where they can be used to solve nonlinear control problems. One of these ANNs applications is that of the inverse kinematic problem, which is important in robot path planning. In this paper, a neural network is employed to analyse of inverse kinematics of PUMA 560 type robot. The neural network is designed to find exact kinematics of the robot. The neural network is a feedforward neural network (FNN). The FNN is trained with different types of learning algorithm for designing exact inverse model of the robot. The Unimation PUMA 560 is a robot with six degrees of freedom and rotational joints. Inverse neural network model of the robot is trained with different learning algorithms for finding exact model of the robot. From the simulation results, the proposed neural network has superior performance for modelling complex robot's kinematics.

Evaluation of anxiety level changes during the first three months of orthodontic treatment

Ersin Yıldırım and Seniz Karacay 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.4

Objective: To determine the changes in dental anxiety, state anxiety, and trait anxiety levels of patients and their parents after 3 months of active orthodontic treatment. Methods: We evaluated 120 patients and one parent of each patient. State Anxiety (STAI-S), Trait Anxiety (STAI-T), and Corah s Dental Anxiety Scale (DAS) were administered before orthodontic treatment (T1) and after 3 months of treatment (T2). Differences in scores between T1 and T2 were compared using paired-sample t-tests and the relationship between the scores of the DAS and the STAI were analyzed using a bivariate two-tailed Pearson correlation test. Results: Dental anxiety and state anxiety levels decreased among the patients after adjustment to orthodontic treatment (p < 0.001). However, 3 months of treatment was not sufficient to decrease the anxiety levels of parents (p > 0.05). Patient trait anxiety affected patient state anxiety and dental anxiety (p < 0.01). Additionally, a significant correlation was found between patient dental anxiety and parent dental anxiety (p < 0.05). Conclusions: Dental anxiety and state anxiety levels decrease after patients become familiar with their orthodontist and they became accustomed to orthodontic treatment. However, 3 months is not a sufficient length of time to decrease parental anxiety levels. [Korean J Orthod 2012;42(4):201-206]

Investigation of Dielectric Properties of Polyethylene-Clay Nanocomposites for Quantifying Nanofiller Dispersion

Saffettin Yıldırım,Kubra Pehlivan,Ali Durmu?,Kadir Esmer 한국고분자학회 2018 폴리머 Vol.42 No.5

This study examined the dielectric properties of linear low density polyethylene (LLDPE)/organo-clay nanocomposites including the same amount of maleic anhydride grafted polyethylene (PE-g-MA) and oxidized polyethylene (OxPE) as compatibilizer at different frequencies (10-1-10+7 Hz) and temperatures (237-373 K). The dielectric constant of natural LLDPE remained constant at around 1.5, depending on the temperature rise and frequency while that of LLDPE-PE-g-MA/clay and LLDPE-OxPE/clay nanocomposites increased up to 4.8 and 2.8, respectively, linearly with increasing temperature. Especially in the low frequency region, a Maxwell-Wagner-Sillars polarization was observed in composite structures with an increase in temperature due to the dipolar effect. It has been concluded that the clay in the polymer matrix was more homogeneously dispersed than OxPE due to the compatibilizing effect of PE-g-MA and that different polarization mechanisms were at play for each compatibilizer.

Evaluation of anxiety level changes during the first three months of orthodontic treatment

Ersin Yıldırım,Seniz Karacay 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.4

Objective: To determine the changes in dental anxiety, state anxiety, and trait anxiety levels of patients and their parents after 3 months of active orthodontic treatment. Methods: We evaluated 120 patients and one parent of each patient. State Anxiety (STAI-S), Trait Anxiety (STAI-T), and Corah’s Dental Anxiety Scale (DAS) were administered before orthodontic treatment (T1) and after 3 months of treatment (T2). Differences in scores between T1 and T2 were compared using paired-sample t-tests and the relationship between the scores of the DAS and the STAI were analyzed using a bivariate two-tailed Pearson correlation test. Results: Dental anxiety and state anxiety levels decreased among the patients after adjustment to orthodontic treatment (p < 0.001). However, 3 months of treatment was not sufficient to decrease the anxiety levels of parents (p > 0.05). Patient trait anxiety affected patient state anxiety and dental anxiety (p < 0.01). Additionally, a significant correlation was found between patient dental anxiety and parent dental anxiety (p < 0.05). Conclusions: Dental anxiety and state anxiety levels decrease after patients become familiar with their orthodontist and they became accustomed to orthodontic treatment. However, 3 months is not a sufficient length of time to decrease parental anxiety levels.

Comparison of optimized roughness parameters of some artificially roughened solar air heaters

Cihan Yıldırım,Ibrahim Aydoğdu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.10

In this study, theoretical investigation derived from experimental correlations and the artificial bee colony optimization method are used to determine the optimum geometrical parameters which maximize the termohydraulic efficiency of some artificially roughened solar air heaters. Nine different roughness types are considered, i.e., transverse wedge-shaped rib roughness, protrusion roughness, multiple v-ribs roughness, rib-grooved roughness, metal grit ribs roughness, compound turbulators roughness, v-shaped rib roughness, arc-shaped wire roughness, and discrete v-down ribs roughness. The effects of the artificial roughness element parameters on the best thermal performance and the thermohydraulic performance are compared. Optimum results are obtained with multiple v-ribs roughness for the low mass flow rate (MFR = 0.1 kg/s) and with protrusion roughness for the high mass flow rate (MFR = 0.5 kg/s). Optimum roughness parameters and corresponding thermal and thermohydraulic efficiencies are tabulated for each solar collector type. As expected, increased roughness geometry leads to higher pressure loss and reduces thermohydraulic efficiency.

Artificial bee colony algorithm for thermohydraulic optimization of flat plate solar air heaters

Cihan Yıldırım,İbrahim Aydoğdu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.7

Determination of thermal efficiency is not a sufficient tool for solar air heaters because of disregarded energy consumption by fans. Most of the solar air heaters are equipped with fans in order to overcome pressure drops. Thermohydraulic efficiency is more favorable than thermal efficiency in terms of the design of solar energy conversion systems. In this present study, Artificial bee colony (ABC) based optimum design and operation algorithm is developed for Single pass solar air heater (SPSAH) and for Double parallel pass solar air heater (DPPSAH) which maximizes thermohydraulic efficiency. In order to solve the algorithm, channel depth is treated as a design variable, and air mass flow rate is defined as an operation parameter. Furthermore, energy balance equations are written for solar air heaters and solved for steady-state condition. As a result, optimum design and operation values are obtained from the algorithm for different collector lengths and solar insolation levels.

Velocity Distribution Upstream of Circular and Square Intakes

Nevzat Yıldırım,Kerem Taştan 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.1

In the present study, a practical method is developed to predict the radial velocity of the flow towards circular and square intakes. It is shown that one single spherical sink surface passing from the desired points that have radial velocity vectors of identical magnitude within the ambient fluid can be used for the prediction of the radial velocity. The specific imaginary center of the corresponding spherical sink surface should be located on the center-line axis downstream of the entrance of the intake. As opposed to the previous studies, the proposed method does not require the solution of equations in closed-integral form, and it can also be used for the orifice-intake not opening into the atmosphere (submerged outlet), and an intake with a pipe, or intake-pipe projecting into the ambient fluid. It is shown that velocity field can be predicted with the introduced method even in the case of circulation imposed or induced ambient fluid flow. The agreement between the theoretical results and the available experimental/numerical results was found to be good.

Analysis of the Parameters Affecting the Efficiency of the Wireless Power Transmission System Designed for New Generation Electric Vehicles

Özüpak Yıldırım 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.6

In magnetic resonance coupled wireless power transfer (WPT) systems, parameters were investigated in the WPT system to ensure maximum power transfer under the conditions of changing the distance between the receive coil and the transmit coil. When the distance between the transceiver coils is changed, the inductances of the system and the coupling coefficient for maximum power transfer were calculated with Maxwell-3D, which performed a solution based on the finite element method (FEM). In addition, the effect of the distance variation between the transmitter and receiver coils, the coupling coefficient (k) values, on the input inductance and power transmission was investigated. In the model developed in the ANSYS-Maxwell environment, it has been observed that the variation of the input inductance depending on the distance and therefore the common inductance between the transmitter and receiver coils can be analyzed. In addition, the effect of the coupling factor (k) on the WPT system has also been demonstrated. It has been shown that maximum power transfer can be sustained in WPT systems where the distance between the receive coil and the transmit coil varies within certain limits. Finally, the efficiency of the transformer for a close distance between the coils was also tested experimentally.

Letters to the Editor : Importance of Rectal Urgency in Childhood Irritable Bowel Syndrome

( Sule Yıldırım ) 대한소화기기능성질환·운동학회(구 대한소화관운동학회) 2014 Journal of Neurogastroenterology and Motility (JNM Vol.20 No.2