Altered mitochondrial metabolism in the insulin-resistant heart.

Obesity-induced insulin resistance and type 2 diabetes mellitus can ultimately result in various complications, including diabetic cardiomyopathy. In this case, cardiac dysfunction is characterized by metabolic disturbances such as impaired glucose oxidation and an increased reliance on fatty acid (FA) oxidation. Mitochondrial dysfunction has often been associated with the altered metabolic function in the diabetic heart, and may result from FA-induced lipotoxicity and uncoupling of oxidative phosphorylation. In this review, we address the metabolic changes in the diabetic heart, focusing on the loss of metabolic flexibility and cardiac mitochondrial function. We consider the alterations observed in mitochondrial substrate utilization, bioenergetics and dynamics, and highlight new areas of research which may improve our understanding of the cause and effect of cardiac mitochondrial dysfunction in diabetes. Finally, we explore how lifestyle (nutrition and exercise) and pharmacological interventions can prevent and treat metabolic and mitochondrial dysfunction in diabetes.COST Action MitoEAGL

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Growth of Cu 2 ZnSnS 4 (CZTS) thin films using short sulfurization periods

In this study CZTS thin films were grown by a two-stage process that involved sequential sputter deposition of metallic Cu, Zn, and Sn layers on Mo coated glass substrates followed by RTP annealing at 530 and 560 °C for various dwell times (1, 60, and 180 s). CZTS thin films obtained by reaction at different sulfurization temperatures and reaction times were characterized employing XRD, Raman spectroscopy, SEM, EDX, and photoluminescence. It was observed that it is possible to obtain Cu-poor and Zn-rich CZTS thin films with short dwell time of reactions. XRD pattern and Raman spectra of the films showed formation of kesterite CZTS structure and some secondary phases such as CuS, SnS, SnS 2 . The full-width-at-half-maximum (FWHM) values extracted from the (112) diffraction peaks of the CZTS thin films showed that extension of the sulfurization time provides better crystalline quality except for the CZTS560-60 thin film. SEM surface microstructure of the films displayed non-uniform, dense, and polycrystalline structure. The optical band gap of the films as determined by photoluminescence was found to be about 1.36-1.38 eV. © 2019 IOP Publishing Ltd

Growth of Cu2ZnSnS4 (CZTS) thin films using short sulfurization periods

Olgar, Mehmet Ali/0000-0002-6359-8316;WOS: 000457544900001In this study CZTS thin films were grown by a two-stage process that involved sequential sputter deposition of metallic Cu, Zn, and Sn layers on Mo coated glass substrates followed by RTP annealing at 530 and 560 degrees C for various dwell times (1, 60, and 180 s). CZTS thin films obtained by reaction at different sulfurization temperatures and reaction times were characterized employing XRD, Raman spectroscopy, SEM, EDX, and photoluminescence. It was observed that it is possible to obtain Cu-poor and Zn-rich CZTS thin films with short dwell time of reactions. XRD pattern and Raman spectra of the films showed formation of kesterite CZTS structure and some secondary phases such as CuS, SnS, SnS2 . the full-width-at-half-maximum (FWHM) values extracted from the (112) diffraction peaks of the CZTS thin films showed that extension of the sulfurization time provides better crystalline quality except for the CZTS560-60 thin film. SEM surface microstructure of the films displayed non-uniform, dense, and polycrystalline structure. the optical band gap of the films as determined by photoluminescence was found to be about 1.36-1.38 eV

CZTS layers formed under sulfur-limited conditions at above atmospheric pressure

Olgar, Mehmet Ali/0000-0002-6359-8316;WOS: 000450320600016In this study CZTS thin films were grown by a two-stage process that involved sequential sputter deposition of metallic Cu, Zn, and Sn layers on Mo coated glass substrates followed by RTP annealing in a sulfur atmosphere at background gas pressures in the range of 1-2 atm. Sulfurization was carried out in a mini reaction volume that provided a relatively S-limited environment Reacted films were characterized using XRD, EDX, SEM, photoluminescence and Raman spectroscopy. It was found that, under the S-limited regime provided in these experiments the Cu-S secondary phase formation was most extreme in the sample grown at 1.5 aim, whereas films grown at lower and higher pressures showed much smaller degree of phase separation. Reaction at 2 atm yielded a compound film that was the closest to the initial precursor in terms of its composition. SEM micrographs showed rough morphology and polycrystalline structure that changed with the sulfurization pressure. the optical band gap of the films as determined by photoluminescence was found to be about 1.37 eV. These experiments demonstrated the importance of the sulfurization pressure as well as the size of the reactor internal volume in determining secondary phase formation in two-stage processed CZTS layers

Growth and characterization of Cu2SnS3 (CTS), Cu2SnSe3 (CTSe), and Cu2Sn(S,Se)3 (CTSSe) thin films using dip-coated Cu–Sn precursor

Ternary compounds Cu2SnS3, Cu2SnSe3 and Cu2Sn(S,Se)3 thin films used in thin film solar cell applications were prepared at the first time by such a two-stage process that includes dip-coating of Cu–Sn precursors as distinct from vacuum-based fabrication methods followed by sulfurization/selenization of prepared precursors via rapid thermal processing at 550 °C. All prepared thin films revealed Cu-poor composition. X-ray diffraction and Raman spectra of the samples showed that Cu2SnS3 and Cu2SnSe3 thin films had a monoclinic structure as a dominant phase and additionally some secondary phases such as tetragonal Cu2SnS3 and orthorhombic Cu3SnS4. However, the tetragonal and orthorhombic phases had more impact on Cu2Sn(SSe)3 thin film. Compact, dense, and small grained surface morphologies were obtained for the Cu2SnS3 and Cu2Sn(SSe)3 thin films, while the surface morphology of the Cu2SnSe3 thin film had larger grained surface morphology. The Cu2SnS3 thin film demonstrated higher transmittance (~ 65%) and two different absorption edges that indicates formation of two band gap energy. Band gap values of Cu2SnS3, Cu2Sn(SSe)3 and Cu2SnSe3 thin films were found 0.97 eV (and 1.51 eV), 1.25 eV and 0.78 eV, respectively. The lowest resistivity (2.48 × 10-1 ? cm) and the highest carrier concentration (1.64 × 1019 cm-3) values were observed for Cu2Sn(SSe)3 thin film. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.Recep Tayyip Erdogan ÜniversitesiThis work was supported by the research fund of Recep Tayyip Erdogan University, Rize, Turkey, under Contract No. FDK-2018-96

Cu(In,Ga)(Se,Te)(2) films formed on metal foil substrates by a two-stage process employing electrodeposition and evaporation

Olgar, Mehmet Ali/0000-0002-6359-8316;WOS: 000427524100006Cu(In,Ga)(Se,Te)(2) or CIGST films were grown over molybdenum coated stainless steel foil substrates using a two-stage technique. the process involved deposition of a Cu-In-Ga/Se-Te precursor stack over the Mo layer using electrodeposition for the metals and evaporation for the chalcogens. the stack was then annealed at 600 degrees C to initiate reaction between the constituent elements. the reacted films were characterized in terms of their structural, compositional, electrical and optical properties. Results were compared to films obtained using all-evaporated precursor stacks formed on glass substrates. It was observed that the compositional control and the morphological properties of the compound layers grown on the metal foil substrates employing electrodeposition and rapid thermal annealing were superior to the films obtained on glass substrates using evaporated precursors and slower temperature ramp rate during annealing. Glancing angle XRD measurements at the front and back surfaces of the layers showed that Ga distribution through the CIGT films was much more uniform than that through the CIGS layers. CIGST films, which contained both Se and Te had slightly Se-rich surface compared to their bulk