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    Altered Stem Cell Receptor Activity in the Ovarian Surface Epithelium by Exogenous Zinc and/or Progesterone
    (Georg Thieme Verlag Kg, 2015) Oktem, G.; Sahin, C.; Dilsiz, O. Y.; Demiray, S. B.; Goker, E. N. T.; Tavmergen, E.
    Background: Ovarian surface epithelium (OSE) has the characteristics of a stem cell and the potential for differentiation. Previous studies on this subject have succeeded in deriving oocytes from OSE stem cells, leading to the belief that OSE could be used for infertility treatment. Methods: Each rat (n=10) was subjected to zinc and/or progesterone injection for 5 days after conception. After a 6-day implantation period, ovarian tissues were removed and comprehensive immunohistochemical analysis of stem cell markers was conducted: Sox2, Klf4, Oct3/4, c-Myc, CD117, CD90, SSEA-1 and Notch pathway analysis; Notch1, Jagged1, and Delta1 in the OSE and ovarian stromal cells were evaluated after treatment with zinc, progesterone, or both. Results: Progesterone moderately affected Sox2 expression (p<0.001), while zinc application strongly affected Klf4 and Oct3/4 and immunoreactivity (p<0.001). CD90 immunoreactivity was decreased in the OSE and stroma of the progesterone group (p=0.006) compared with the zinc (p=0.244) and zinc/progesterone groups (p=0.910). On the other hand, SSEA-1 showed moderate staining in the OSE and weak staining in stromal cells in animals treated with zinc (p=0.727), progesterone (p=0.626), and zinc/progesterone (p=0.371), with no differences compared with control. Zinc application affected Notch pathway immunoreactivity, with a significant increase in Notch1 (p=0.0015) and Jagged1 (p<0.001). Conclusions: The expression of putative stem cell markers in the OSE was verified and stem cell receptor activity was raised in the OSE and ovarian stromal cells by zinc and progesterone. Thus, this increased expression allows the therapeutic use of zinc and progesterone in ovary-related infertility and brings a different perspective to reproductive medicine.
  • Küçük Resim Yok
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    Altered Stem Cell Receptor Activity in the Ovarian Surface Epithelium by Exogenous Zinc and/or Progesterone
    (Georg Thieme Verlag Kg, 2015) Oktem, G.; Sahin, C.; Dilsiz, O. Y.; Demiray, S. B.; Goker, E. N. T.; Tavmergen, E.
    Background: Ovarian surface epithelium (OSE) has the characteristics of a stem cell and the potential for differentiation. Previous studies on this subject have succeeded in deriving oocytes from OSE stem cells, leading to the belief that OSE could be used for infertility treatment. Methods: Each rat (n=10) was subjected to zinc and/or progesterone injection for 5 days after conception. After a 6-day implantation period, ovarian tissues were removed and comprehensive immunohistochemical analysis of stem cell markers was conducted: Sox2, Klf4, Oct3/4, c-Myc, CD117, CD90, SSEA-1 and Notch pathway analysis; Notch1, Jagged1, and Delta1 in the OSE and ovarian stromal cells were evaluated after treatment with zinc, progesterone, or both. Results: Progesterone moderately affected Sox2 expression (p<0.001), while zinc application strongly affected Klf4 and Oct3/4 and immunoreactivity (p<0.001). CD90 immunoreactivity was decreased in the OSE and stroma of the progesterone group (p=0.006) compared with the zinc (p=0.244) and zinc/progesterone groups (p=0.910). On the other hand, SSEA-1 showed moderate staining in the OSE and weak staining in stromal cells in animals treated with zinc (p=0.727), progesterone (p=0.626), and zinc/progesterone (p=0.371), with no differences compared with control. Zinc application affected Notch pathway immunoreactivity, with a significant increase in Notch1 (p=0.0015) and Jagged1 (p<0.001). Conclusions: The expression of putative stem cell markers in the OSE was verified and stem cell receptor activity was raised in the OSE and ovarian stromal cells by zinc and progesterone. Thus, this increased expression allows the therapeutic use of zinc and progesterone in ovary-related infertility and brings a different perspective to reproductive medicine.
  • Küçük Resim Yok
    Öğe
    Altered Stem Cell Receptor Activity in the Ovarian Surface Epithelium by Exogenous Zinc and/or Progesterone
    (Georg Thieme Verlag Kg, 2015) Oktem, G.; Sahin, C.; Dilsiz, O. Y.; Demiray, S. B.; Goker, E. N. T.; Tavmergen, E.
    Background: Ovarian surface epithelium (OSE) has the characteristics of a stem cell and the potential for differentiation. Previous studies on this subject have succeeded in deriving oocytes from OSE stem cells, leading to the belief that OSE could be used for infertility treatment. Methods: Each rat (n=10) was subjected to zinc and/or progesterone injection for 5 days after conception. After a 6-day implantation period, ovarian tissues were removed and comprehensive immunohistochemical analysis of stem cell markers was conducted: Sox2, Klf4, Oct3/4, c-Myc, CD117, CD90, SSEA-1 and Notch pathway analysis; Notch1, Jagged1, and Delta1 in the OSE and ovarian stromal cells were evaluated after treatment with zinc, progesterone, or both. Results: Progesterone moderately affected Sox2 expression (p<0.001), while zinc application strongly affected Klf4 and Oct3/4 and immunoreactivity (p<0.001). CD90 immunoreactivity was decreased in the OSE and stroma of the progesterone group (p=0.006) compared with the zinc (p=0.244) and zinc/progesterone groups (p=0.910). On the other hand, SSEA-1 showed moderate staining in the OSE and weak staining in stromal cells in animals treated with zinc (p=0.727), progesterone (p=0.626), and zinc/progesterone (p=0.371), with no differences compared with control. Zinc application affected Notch pathway immunoreactivity, with a significant increase in Notch1 (p=0.0015) and Jagged1 (p<0.001). Conclusions: The expression of putative stem cell markers in the OSE was verified and stem cell receptor activity was raised in the OSE and ovarian stromal cells by zinc and progesterone. Thus, this increased expression allows the therapeutic use of zinc and progesterone in ovary-related infertility and brings a different perspective to reproductive medicine.
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    Comparative studies of pyridine and bipyridine ruthenium dye complexes with different side groups as sensitizers in sol-gel quasi-solid-state dye sensitized solar cells
    (Pergamon-Elsevier Science Ltd, 2015) Sygkridou, D.; Sahin, C.; Varlikli, C.; Stathatos, E.
    Six ruthenium(II) complexes as charge-transfer sensitizers for dye sensitized solar cells (DSSCs) are synthesized. The absorption and electrochemical properties of newly synthesized ruthenium-dye molecules contained one bipyridine (bpy) ligand with two carboxylic groups have been investigated. Among them, four ruthenium(II) complexes contain a second bpy ligand with branching and non-branching side groups containing C and H only and the remaining two ruthenium(II) complexes instead of a second bipyridine (bpy) ligand, they consisted of a pyridine (py) ligand with side groups containing -C-O-C-molecular group. Dye sensitized solar cells employing quasi-solid state electrolyte and the six ruthenium complexes are constructed and electrically characterized under standard conditions of light irradiance (1000 W/m(2), AM 1.5). Their behavior is compared with that of commercially available ruthenium complex D907 in terms of current-voltage characteristic curves under simulated light and dark while electrochemical impedance spectroscopy showed comparable results for local resistance to charge transfer across the TiO2-electrolyte interface and free electron lifetimes for two bipyridine and commercial D907 complexes. The influence of molecular side groups into ruthenium-dye molecules is discussed in terms of the cells' efficiency. (C) 2015 Elsevier Ltd. All rights reserved.
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    Comparative studies of pyridine and bipyridine ruthenium dye complexes with different side groups as sensitizers in sol-gel quasi-solid-state dye sensitized solar cells
    (Pergamon-Elsevier Science Ltd, 2015) Sygkridou, D.; Sahin, C.; Varlikli, C.; Stathatos, E.
    Six ruthenium(II) complexes as charge-transfer sensitizers for dye sensitized solar cells (DSSCs) are synthesized. The absorption and electrochemical properties of newly synthesized ruthenium-dye molecules contained one bipyridine (bpy) ligand with two carboxylic groups have been investigated. Among them, four ruthenium(II) complexes contain a second bpy ligand with branching and non-branching side groups containing C and H only and the remaining two ruthenium(II) complexes instead of a second bipyridine (bpy) ligand, they consisted of a pyridine (py) ligand with side groups containing -C-O-C-molecular group. Dye sensitized solar cells employing quasi-solid state electrolyte and the six ruthenium complexes are constructed and electrically characterized under standard conditions of light irradiance (1000 W/m(2), AM 1.5). Their behavior is compared with that of commercially available ruthenium complex D907 in terms of current-voltage characteristic curves under simulated light and dark while electrochemical impedance spectroscopy showed comparable results for local resistance to charge transfer across the TiO2-electrolyte interface and free electron lifetimes for two bipyridine and commercial D907 complexes. The influence of molecular side groups into ruthenium-dye molecules is discussed in terms of the cells' efficiency. (C) 2015 Elsevier Ltd. All rights reserved.
  • Küçük Resim Yok
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    Comparative studies of pyridine and bipyridine ruthenium dye complexes with different side groups as sensitizers in sol-gel quasi-solid-state dye sensitized solar cells
    (Pergamon-Elsevier Science Ltd, 2015) Sygkridou, D.; Sahin, C.; Varlikli, C.; Stathatos, E.
    Six ruthenium(II) complexes as charge-transfer sensitizers for dye sensitized solar cells (DSSCs) are synthesized. The absorption and electrochemical properties of newly synthesized ruthenium-dye molecules contained one bipyridine (bpy) ligand with two carboxylic groups have been investigated. Among them, four ruthenium(II) complexes contain a second bpy ligand with branching and non-branching side groups containing C and H only and the remaining two ruthenium(II) complexes instead of a second bipyridine (bpy) ligand, they consisted of a pyridine (py) ligand with side groups containing -C-O-C-molecular group. Dye sensitized solar cells employing quasi-solid state electrolyte and the six ruthenium complexes are constructed and electrically characterized under standard conditions of light irradiance (1000 W/m(2), AM 1.5). Their behavior is compared with that of commercially available ruthenium complex D907 in terms of current-voltage characteristic curves under simulated light and dark while electrochemical impedance spectroscopy showed comparable results for local resistance to charge transfer across the TiO2-electrolyte interface and free electron lifetimes for two bipyridine and commercial D907 complexes. The influence of molecular side groups into ruthenium-dye molecules is discussed in terms of the cells' efficiency. (C) 2015 Elsevier Ltd. All rights reserved.
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    Role of side groups in pyridine and bipyridine ruthenium dye complexes for modulated surface photovoltage in nanoporous TiO2
    (Elsevier Science Bv, 2010) Sahin, C.; Dittrich, Th.; Varlikli, C.; Icli, S.; Lux-Steiner, M. Ch.
    The influence of molecular side groups on the electron backtransfer into ruthenium-dye molecules adsorbed on ultra-thin nanoporous TiO2 layers has been investigated by modulated surface photovoltage spectroscopy in argon atmosphere. All ruthenium-dye molecules contained one bipyridine (bpy) ligand with two carboxylic groups for anchoring at the TiO2 surface. Ruthenium (II) complexes with a second bpy ligand with branching and non-branching side groups containing C and H only and ruthenium (II) complexes with a second pyridine (py) ligand with side groups containing different numbers of -C-O-C- sequences were synthesized. The electron backtransfer was practically not affected by branching or non-branching side groups in the bpy-bpy complexes. In contrast, electron backtransfer was much less for bpy-py complexes in comparison to bpy-bpy complexes and increased strongly with increasing number of -C-O-C- sequences in the side groups. (C) 2009 Elsevier B.V. All rights reserved.