924 research outputs found

    Kinetin (N6-furfuryladenine): Cytotoxicity against MCF-7 breast cancer cell line and interaction with bovine serum albumin

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    N6-furfuryladenine (kinetin) is a cytokinin growth factor with several biological effects observed in human cells and fruit flies. Kinetin exists naturally in the DNA of almost all organisms tested so far, including human cells and various plants. The cytotoxicity effect of kinetin on MCF-7 breast cancer cell lines was measured by the sulforhodamine B (SRB) assay and the results showed that kinetin could inhibit cell growth in a dose-dependent manner with an IC50 value of 52 μmol/L at 96 h after the drug was added into the culture. The interaction of bovine serum albumin (BSA) with kinetin was studied in aqueous solution at physiological conditions, using constant protein concentration and various drug contents. UV-vis spectroscopic method was used to determine kinetin binding mode, the binding constant and the effects of kinetin complexation on protein structure. The spectroscopic results showed that kinetin is located along the polypeptide chains with overall affinity constant of KKinetin-BSA = 6.8 x 104 M-1.Key words: N6-furfuryladenine (kinetin), MCF-7, cytotoxicity, sulforhodamine B (SRB), bovine serum albumin (BSA)

    Evaluation of the Use and Reasons for Not Using a Helmet by Motorcyclists Admitted to the Emergency Ward of Shahid Bahonar Hospital in Kerman

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    Background: Motorcycle crashes are the cause of severe morbidity and mortality especially because of head injuries. It seems that wearing a helmet has an effective role in protection against head injuries. Nevertheless, motorcyclists usually have no tendency to wear a helmet when driving in cities and have several reasons for this behavior. Objectives: This study aimed to evaluate the use and reasons for not using a helmet by motorcyclists admitted to an emergency ward of a trauma hospital due to accident in Kerman, Iran. Patients and Methods: This study was carried out by recoding the opinions of motorcyclists who had been transferred to the emergency ward of Shahid Bahonar Hospital (Kerman/Iran). Since no data was available on the frequency of the use of helmets, a pilot study was carried out and a sample size of 377 was determined for the main study. Then a researcher-made questionnaire was used to investigate the motorcyclists’ reasons for not using a helmet. Results: Only 21.5% of the motorcyclists had been wearing helmets at the time of the accident. The most frequent reasons for not using a helmet were the heavy weight of the helmet (77%), feeling of heat (71.4%), pain in the neck (69.4%), feeling of suffocation (67.7%), limitation of head and neck movements (59.6%) and all together, physical discomfort was the main cause of not wearing a helmet during motorcycle rides. Conclusions: In general, it appears that it is possible to increase the use of helmets by eliminating its physical problems, and increasing the knowledge of community members in relation to the advantages of helmet use, which will result in a significant decrease in traumas resulting from motorcycle accidents

    WingSegment: A Computer Vision‐Based Hybrid Approach for Insect Wing Image Segmentation and 3D Printing

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    This article introduces WingSegment, a MATLAB app‐designed tool employing a hybrid approach of computer vision and graph theory for precise insect wing image segmentation. WingSegment detects cells, junctions, Pterostigma, and venation patterns, measuring geometric features and generating Voronoi patterns. The tool utilizes region‐growing, thinning, and Dijkstra's algorithms for boundary detection, junction identification, and vein path extraction. It provides histograms and box plots of geometric features, facilitating comprehensive wing analysis. WingSegment's efficiency is validated through comparisons with established tools and manual measurements, demonstrating accurate results. The tool further enables exporting detected boundaries as FreeCAD macro files for 3D modeling and printing, supporting finite element analysis. Beyond advancing insect wing morphology understanding, WingSegment holds broader implications for diverse planar structures, including leaves and geocells. This tool not only enhances automated geometric analysis and 3D model generation in insect wing studies but also contributes to the broader advancement of analysis, 3D printing, and modeling technologies across various planar structures

    Locomotory Behavior of Water Striders with Amputated Legs

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    The stability of the body during locomotion is a fundamental requirement for walking animals. The mechanisms that coordinate leg movement patterns are even more complex at water–air interfaces. Water striders are agile creatures on the water surface, but they can be vulnerable to leg damage, which can impair their movement. One can assume the presence of certain compensatory biomechanical factors that are involved in the maintenance of postural balance lost after an amputation. Here, we studied changes in load distribution among the legs and assessed the effects of amputation on the locomotory behavior and postural defects that may increase the risk of locomotion failure. Apparently, amputees recover a stable posture by applying leg position modifications (e.g., widening the stance) and by load redistribution to the remaining legs. Water striders showed steering failure after amputation in all cases. Amputations affected locomotion by (1) altering motion features (e.g., shorter swing duration of midlegs), (2) functional constraints on legs, (3) shorter travelled distances, and (4) stronger deviations in the locomotion path. The legs functionally interact with each other, and removal of one leg has detrimental effects on the others. This research may assist the bioinspired design of aquatic robots

    Patterns of load distribution among the legs in small water striders during standing and striding

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    Water striders (Gerris argentatus) move across the water surface by taking advantage of the surface tension, which supports their bodyweight without breaking. During locomotion, the midlegs are primarily responsible for generating thrust, whereas the other legs support the body. Although the aspects of standing and locomotion on the water surface are well understood, relatively fewer studies concerned the coordinated biomechanical movements of the legs. In order to maintain buoyancy of the body on the water surface, the leg positions must be adjusted to distribute the bodyweight appropriately. The present study investigates distribution of the bodyweight on the legs in relatively small water striders. We aimed to understand how loading on the legs changes during sculling that leads to sliding of the body on the water surface. The assistance of all legs at every moment enables the body to maintain its floating during standing and striding. Water striders can achieve a gentle striding through the midlegs driving phase in association with smooth load shifting among their legs, which are positioned in a specific configuration to support the insect on the water surface

    Synthesis and antiproliferative activity of diethyl 5- acetyl-4-methyl- 6-(2-fluorophenylimino)-6H-thiopyran- 2,3-dicarboxylate (3TM)

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    Diethyl 5-acetyl-4-methyl-6-(2-fluorophenylimino)-6H-thiopyran-2,3-dicarboxylate (3TM) was synthesized and the antiproliferative activity of 3TM is reported here. Compound 3TM inhibits the growth of human colon cancer HCT-15 with an IC50 value of 4.5 μM and breast cancer MCF-7 with an IC50 value of 7 μM in a dose/time dependent manner by using sulforhodamine B assay. Moreover, suppression of clonogenic activity occurs after exposure to 3TM at a concentration of 3 μM for HCT-15 and of 5 μM for MCF-7. The effect of ligand complexation on DNA structure led to the overall affinity constant of K3M-DNA = 2.4 x 104 M-1.Key words: Diethyl 5-acetyl-4-methyl-6-(2-fluorophenylimino)-6H-thiopyran-2,3-dicarboxylate (3TM), synthesis, antiproliferative activity

    Coordinated operation of electric vehicle charging and wind power generation as a virtual power plant: A multi-stage risk constrained approach

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    © 2019 Elsevier Ltd As the number of electric vehicles (EVs) is steadily increasing, their aggregation can offer significant storage to improve the electric system operation in many aspects. To this end, a comprehensive stochastic optimization framework is proposed in this paper for the joint operation of a fleet of EVs with a wind power producer (WPP) in a three-settlement pool-based market. An aggregator procures enough energy for the EVs based on their daily driving patterns, and schedules the stored energy to counterbalance WPP fluctuations. Different sources of uncertainty including the market prices and WPP generation are modeled through proper scenarios, and the risk is hedged by adding a risk measure to the formulation. To obtain more accurate results, the battery degradation costs are also included in the problem formulation. A detailed case study is presented based on the Iberian electricity market data as well as the technical information of three different types of EVs. The proposed approach is benchmarked against the disjoint operation of EVs and WPP. Numerical simulations demonstrate that the proposed strategy can effectively benefit EV owners and WPP by reducing the energy costs and increasing the profits

    A review on economic and technical operation of active distribution systems

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    © 2019 Elsevier Ltd Along with the advent of restructuring in power systems, considerable integration of renewable energy resources has motivated the transition of traditional distribution networks (DNs) toward new active ones. In the meanwhile, rapid technology advances have provided great potentials for future bulk utilization of generation units as well as the energy storage (ES) systems in the distribution section. This paper aims to present a comprehensive review of recent advancements in the operation of active distribution systems (ADSs) from the viewpoint of operational time-hierarchy. To be more specific, this time-hierarchy consists of two stages, and at the first stage of this time-hierarchy, four major economic factors, by which the operation of traditional passive DNs is evolved to new active DNs, are described. Then the second stage of the time-hierarchy refers to technical management and power quality correction of ADSs in terms of static, dynamic and transient periods. In the end, some required modeling and control developments for the optimal operation of ADSs are discussed. As opposed to previous review papers, potential applications of devices in the ADS are investigated considering their operational time-intervals. Since some of the compensating devices, storage units and generating sources may have different applications regarding the time scale of their utilization, this paper considers real scenario system operations in which components of the network are firstly scheduled for the specified period ahead; then their deviations of operating status from reference points are modified during three time-intervals covering static, dynamic and transient periods
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