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Specific Morphologies (specific + morphology)
Selected AbstractsAncestors and variants: tales from the crypticEVOLUTION AND DEVELOPMENT, Issue 3 2000William E. Browne SUMMARY Those who work at the interface of development and evolution are united by the conviction that developmental comparisons can shed light on both the evolution of specific morphologies and the macroevolutionary process itself. In practice, however, the field comprises a diversity of approaches. As the field grows and practitioners attempt to digest a growing mountain of comparative data, the various approaches of "Evo Devo" have themselves evolved. A meeting organized by the authors and held at the University of Chicago in the Spring of 1999 illustrated some of these changes. This review will draw on its content to discuss recent developments in two areas: the reconstruction of common ancestors and the developmental basis of evolutionary change. [source] The influence of solution-state conditions and stirring rate on the assembly of poly(acrylic acid)-containing amphiphilic triblock copolymers with multi-aminesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2010Jennifer L. Sorrells Abstract In the effort towards making nanoscale objects and assemblies feasible for use as functional materials, it is imperative to obtain control over the fundamental architectures and essential to understand what experimental conditions cause the manifestation of specific morphologies. A number of factors are known to influence the shape during the self-assembly of amphiphilic block copolymers in solution, including solvent composition, polymer length, hydrophobicity versus hydrophilicity, as well as the addition of additives that can interact with segments of the block copolymers. This research, focused on developing an understanding of the micellar architectures accessed by the amphiphilic triblock copolymer of acrylic acid, methyl acrylate, and styrene, PAA85 - b -PMA40 - b -PS35, as a function of the stirring rate, together with other factors, when undergoing coassembly with ethylenediamine or diethylenetriamine in water/tetrahydrofuran solutions. The work demonstrates that the rate at which the polymer solution was stirred impacts the shape of the solution-state assemblies formed by the triblock copolymer. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 [source] Formation of microporous poly(hydroxybutyric acid) membranes for culture of osteoblast and fibroblastPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 12 2009Han-Shiang Huag Abstract Microporous membranes of a biodegradable polymer, poly(hydroxybutyric acid) (PHB), were prepared by a phase-inversion process and their cell compatibility was evaluated in vitro. A ternary system, ethanol/chloroform/PHB, was employed to prepare the membranes, wherein ethanol and chloroform were served as the nonsolvent and solvent for PHB, respectively. In the phase-inversion process, the polymer dissolution temperature was varied from 80 to 120°C to yield membranes with specific morphologies, such as globular particles, porous channels, etc. Moreover, cell viability was examined on the formed membranes. Two cell lines, osteoblast hFOB1.19 and fibroblast L929, were cultured in vitro. It was found that these two types of cells exhibited different responses on different membranes: the hFOB1.19 cells showed significant increase in cell proliferation with increase in surface roughness, whereas the L929 cells demonstrated an opposite trend, preferring to attach and grow on a flat surface. PHB membranes with different morphologies exhibit different cell compatibilities, which may be useful means for the architectural design of materials for tissue engineering. Copyright © 2009 John Wiley & Sons, Ltd. [source] Intrachromosomal amplification of chromosome 21 (iAMP21) may arise from a breakage,fusion,bridge cycleGENES, CHROMOSOMES AND CANCER, Issue 4 2007Hazel M. Robinson Intrachromosomal amplification of chromosome 21 (iAMP21), involving amplification of the RUNX1 gene and duplication of chromosome 21, dup(21q), defines a new cytogenetic subgroup in B-lineage acute lymphoblastic leukemia (ALL) with a poor prognosis. Characterization of this abnormality has become vital to ensure that the most accurate detection method is used. We have previously defined common regions of amplification and deletion of chromosome 21 in these patients, although the level and extent of amplification within the amplicon was highly variable. This study, using interphase fluorescence in situ hybridization (FISH) with chromosome 21 locus specific probes, substantiated these findings in a large series of patients and confirmed that the amplicon always included RUNX1. Thus, FISH with probes directed to the RUNX1 gene remains the most reliable detection method. Metaphase FISH, supported by G- and multiple color chromosomal banding (mBAND) revealed the patient specific morphology and genetic profile of the dup(21q) chromosomes, as well as the complexity of the intrachromosomal changes giving rise to them. These findings suggested that iAMP21 had arisen from a breakage,fusion,bridge cycle: a mechanism previously described in tumors, which we report for the first time in ALL. © 2007 Wiley-Liss, Inc. [source] Electrochemical polymerization of pyrrole in cholesteric liquid crystals: Morphology and optical propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2007Hiromasa Goto Abstract Electrochemical polymerization in a cholesteric liquid-crystal electrolyte was carried out. Polypyrrole thus synthesized in a cholesteric liquid-crystal electrolyte could be clearly seen to form a specific morphology. The polypyrrole films exhibited chiroptical properties and formed various surface structures such as Schlieren, Nazca-line, sea-anemone, and wire-loop structures. These structures that developed during polymerization were preserved even after washing. Moreover, no chiral molecule reacted chemically with the monomer during polymerization, and the electrolyte functioned only as a matrix chiral continuum. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1377,1387, 2007. [source] Four cases of distinctive meningiomas with Zellballen growth patternAPMIS, Issue 12 2009YINGCHUN DONG Meningiomas are attributed to those tumours with slow-growing pattern occurring predominantly in middle-aged or elderly patients. Fifteen histological variants have been described based on the variable histomorphological features. Herein we report four cases with specific Zellballen growth pattern, giving the tumours a ,paraganglioma-like' general aspect. The diagnosis of meningiomas was confirmed by immunohistochemical and ultrastructural findings. Histopathologists should be aware of this specific morphology which can lead to misdiagnosis. [source] | |||||||||||||