Adsorption challenge in the PDMS-based microfluidic systems for drug screening application

Drug screening is one of the demand areas due to close and direct dependency on human health. On the other hand, recently microfluidic systems have been increasingly used for drug development and screening purposes. However, this system has some challenges such as adsorption issue which can effect pharmacokinetic-pharmacodynamic (PK-PD) of the drugs. Thus, in this research, the issue was characterized and evaluated by UV-Vis spectrophotometry and FTIR spectroscopy devices as a model drug of cisplatin. Despite of strong relationship between logP and adsorption, and the very low value of logP in the drug candidate, the results for both apical and basal planes of the microfluidic chip confirmed the adsorption. In the UV-Vis spectrophotometry, the basal plane show 5%, and 10% higher adsorption compared to apical and control polydimethylsiloxane (PDMS)-based microfluidic. Additionally, the FTIR patterns were a good coincide with UV-Vis results

Production of AgCu:NiO/Ni foam electrode with high charge accumulation and long cycling stability

Nickel oxide is a promising material for electrochemical energy storage devices due to its high specific surface area, rapid redox reactions, and short diffusion path in the solid electrode. It has been known that the loading of metallic elements into the NiO matrix enhances these superior properties. NiO material is electrochemically deposited on Ni foam, and then, Ag and Cu thin layers are coated on NiO by thermal evaporation. The produced NiO/Ni foam and AgCu:NiO/Ni foam electrodes are annealed at 400 degrees C for 1 h. Those are utilized as anode for high-performance energy storage electrode in an alkaline solution. The former has an energy density of 56.9 Wh kg(-1) at 3155.5 W kg(-1), while the latter has a high energy density of 107.6 Wh kg(-1) at the corresponding power density of 2957.7 W kg(-1). Although specific capacitance of the former decreases to 46.2% of its original capacitance at 10 A g(-1) after 5000 cycles, the latter exhibits higher cycling stability with 71.0% retention after 5000 charge-discharge cycles owing to the loading of Ag and Cu into NiO matrix. Charge transfer resistance of NiO/Ni foam, which is inversely proportional to electroactive surface area, reduces from 19.4 to 0.28 omega after the incorporation of Ag and Cu. Compared to NiO/Ni foam, AgCu:NiO/Ni foam with a higher electroactive surface area is more appropriate for charge accumulation. As mention above, the features of AgCu:NiO/Ni foam indicate that it is a promising material as an effective start-of-art energy storage device.Turkey Scientific and Technological Research Council (TUBITAK) [119F251]; TUBITAKThis work was supported by the Turkey Scientific and Technological Research Council (TUBITAK), Project number 119F251. The authors thank to TUBITAK for financial support

Investigation of the structural, magnetic, and cooling performance of AlFe thin film and AlFeGd nanometric giant magnetocaloric thin films

Giant magnetocaloric thin films are promising materials for new generation energy-efficient cooling systems. To investigate the cooling performance of AlFe and AlFeGd alloys, thin films have been deposited onto a glass substrate by thermionic vacuum arc (TVA) deposition system. TVA is a physical vapor deposition technology; it works in high vacuum and low-temperature conditions. AlFe and AlFeGd thin films are of significant importance for giant magnetocaloric materials. The surface and magnetic properties of a magnetic material are strongly dependent on the deposition process. In this paper, the structural, magnetic, and cooling performances of AlFe alloys with and without the Gd element have been investigated. When the Gd elements are added to AlFe alloys, the size of crystallite and the surface morphology of the giant nanometric magnetocaloric thin films are altered. The size of crystallite decreases to a lower value due to the Gd element added. According to the results of the elemental analysis, the elemental ratios of the AlFe and AlFeGd thin films were measured as (87:13) and (84:4:12), respectively, which are different from the ones reported previously. Magnetic cooling performance and magnetization strongly depend on these ratios. The mean values of crystallite size for the AlFe thin film and AlFeGd nanometric giant magnetocaloric thin film were measured as 50 nm and 12 nm, respectively. Following the Curie temperature of AlFeGd thin film, and the temperature difference it produces in the studied magnetic fields, 60 successive units of this material are assumed to form a magnetic refrigeration cycle. The coefficient of performance of this cycle is calculated to be 2.084—nearly two times better than the suggested cascade vapor-compression cycles in the same temperature range. This fact alongside the solid-state and environmentally friendly attributes of magnetic refrigeration cycles makes the AlFeGd thin films a strong candidate for accomplishing an efficient refrigeration system