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Morphological Organization (morphological + organization)
Selected AbstractsP3HT/PCBM Bulk Heterojunction Solar Cells: Impact of Blend Composition and 3D Morphology on Device PerformanceADVANCED FUNCTIONAL MATERIALS, Issue 9 2010Svetlana S. van Bavel Abstract The performance of polymer solar cells (PSC) strongly depends on the 3D morphological organization of the donor and acceptor compounds within the bulk heterojunction active layer. The technique of electron tomography is a powerful tool for studying 3D morphology of the layers composed of poly(3-hexylthiophene) (P3HT) and a fullerene derivative ([6,6]-phenyl-C61-butyric acid methyl ester; PCBM), especially to quantify the amount and distribution of fibrillar P3HT nanocrystals throughout the volume of the active layer. In this study, electron tomography is used to characterize P3HT/PCBM layers with different blend compositions, both before and after thermal annealing. The power conversion efficiency of the corresponding PSCs is strongly dependent on the overall crystallinity of P3HT and the way P3HT crystals are distributed throughout the thickness of the active layer. [source] Epileptogenic roles of astroglial death and regeneration in the dentate gyrus of experimental temporal lobe epilepsyGLIA, Issue 4 2006Tae-Cheon Kang Abstract Recent studies have demonstrated that blockade of neuronal death in the hippocampus cannot prevent epileptogenesis in various epileptic models. These reports indicate that neurodegeneration alone is insufficient to cause epilepsy, and that the role of astrocytes in epileptogenesis should be reconsidered. Therefore, the present study was designed to elucidate whether altered morphological organization or the functionalities of astrocytes induced by status epilepticus (SE) is responsible for epileptogenesis. Glial responses (reactive microgliosis followed by astroglial death) in the dentate gyrus induced by pilocarpine-induced SE were found to precede neuronal damage and these alterations were closely related to abnormal neurotransmission related to altered vesicular glutamate and GABA transporter expressions, and mossy fiber sprouting in the dentate gyrus. In addition, newly generated astrocytes showed down-regulated expressions of glutamine synthase, glutamate dehydrogenase, and glial GABA transporter. Taken together, our findings suggest that glial responses after SE may contribute to epileptogenesis and the acquisition of the properties of the epileptic hippocampus. Thus, we believe that it is worth considering new therapeutic approaches to epileptogenesis involving targeting the inactivation of microglia and protecting against astroglial loss. © 2006 Wiley-Liss, Inc. [source] Signalling molecules and growth factors for tissue engineering of cartilage,what can we learn from the growth plate?,JOURNAL OF TISSUE ENGINEERING AND REGENERATIVE MEDICINE, Issue 6 2009Christoph Brochhausen Abstract Modern tissue engineering concepts integrate cells, scaffolds, signalling molecules and growth factors. For the purposes of regenerative medicine, fetal development is of great interest because it is widely accepted that regeneration recapitulates in part developmental processes. In tissue engineering of cartilage the growth plate of the long bone represents an interesting, well-organized developmental structure with a spatial distribution of chondrocytes in different proliferation and differentiation stages, embedded in a scaffold of extracellular matrix components. The proliferation and differentiation of these chondrocytes is regulated by various hormonal and paracrine factors. Thus, members of the TGF, superfamily, the parathyroid hormone-related peptide,Indian hedgehog loop and a number of transcription factors, such as Sox and Runx, are involved in the regulation of chondrocyte proliferation and differentiation. Furthermore, adhesion molecules, homeobox genes, metalloproteinases and prostaglandins play a role in the complex regulation mechanisms. The present paper summarizes the morphological organization of the growth plate and provides a short but not exhaustive overview of the regulation of growth plate development, giving interesting insights for tissue engineering of cartilage. Copyright © 2009 John Wiley & Sons, Ltd. [source] Localization of Hyaluronic Acid in the Seminal Vesicles of the Miniature PigANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2007A. Sakairi Summary We studied the detailed localization of hyaluronic acid in the seminal vesicles of the miniature pig, using hyaluronic acid-binding protein as a specific histochemical probe at the ultrastructural level. According to the results, the basolateral surface of the plasma membrane of the glandular epithelial cells, was found to contain hyaluronan. However, abundantly present was hyaluronan in the subepithelial connective tissue, in particular, in the extracellular matrix surrounding the fibroblasts, smooth muscle cells, small blood vessels and capillaries. The substance was also observed in the surface coat of the plasma membrane of the fibroblasts, but not in that of the smooth muscle cells. The findings suggest that hyaluronan in the seminal vesicles of the miniature pig is synthesized onto the surface coat of the plasma membrane of the fibroblasts, is contributed to the extracellular matrix, and consequently concentrates in the subepithelial connective tissue. The substance may particularly be involved in a variety of cellular functions to maintain morphological organization as well as to regulate physiological homeostasis in the reproductive organ of this species, rather than participate in sperm functions. [source] Basilar Artery of the Capybara (Hydrochaeris hydrochaeris): an Ultrastructural StudyANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 2 2004S. Islam Summary The present study investigated the ultrastructural features of the basilar artery of the largest rodent species, the capybara. The study suggests that the general ultrastructural morphological organization of the basilar artery of the capybara is similar to that of small rodents. However, there are some exceptions. The basilar artery of the capybara contains a subpopulation of ,granular' vascular smooth muscle cells resembling monocytes and/or macrophages. The possibility cannot be excluded that the presence of these cells reflects the remodelling processes of the artery due to animal maturation and the regression of the internal carotid artery. To clarify this issue, more systemic studies are required involving capybaras of various ages. [source] | ||||||||||