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Structural Arrangement (structural + arrangement)
Selected AbstractsImproving the ON/OFF Ratio and Reversibility of Recording by Rational Structural Arrangement of Donor,Acceptor MoleculesADVANCED FUNCTIONAL MATERIALS, Issue 5 2010Ying Ma Abstract Organic molecules with donor,acceptor (D,A) structure are an important type of material for nanoelectronics and molecular electronics. The influence of the electron donor and acceptor units on the electrical function of materials is a worthy topic for the development of high-performance data storage. In this work, the effect of different D,A structures (namely D,,,A,,,D and A,,,D,,,A) on the electronic switching properties of triphenylamine-based molecules is investigated. Devices based on D,,,A,,,D molecules exhibit excellent write,read,erase characteristics with a high ON/OFF ratio of up to 106, while that based on A,,,D,,,A molecules exhibit irreversible switching behavior with an ON/OFF ratio of about (3.2,×,101),(1,×,103). Moreover, long retention time of the high conductance state and low threshold voltage are observed for the D,A switching materials. Accordingly, stable and reliable nanoscale data storage is achieved on the thin films of the D,A molecules by scanning tunneling microscopy. The influence of the arrangement of the D and A within the molecular backbone disclosed in this study will be of significance for improving the electronic switching properties (ON/OFF current ratio and reversibility) of new molecular systems, so as to achieve more efficient data storage through appropriate design strategies. [source] ChemInform Abstract: Structural Arrangement of the Ternary Metal Boride Carbide Compounds MB2C4 (M: Mg, Ca, La and Ce) from First-Principles Theory.CHEMINFORM, Issue 38 2008Chang-Ming Fang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Self-Organization of Dipolar 4,4,-Disubstituted 2,2,-Bipyridine Metal Complexes into Luminescent Lamellar Liquid CrystalsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2003Daniela Pucci Abstract Mononuclear cis -dichloro complexes, [LnMCl2], with different metal centres (PtII, NiII, and ZnII) and a series of palladium and platinum derivatives, [L2MX2], in which chloride groups are replaced with iodide, bromide, and azide ligands, have been synthesized from 4,4,-disubstituted-2,2,-bipyridines. Upon complexation of these non-mesogenic ligands, the peculiar structural arrangement, characterized by intermolecular associations of the new derivatives, induces mesomorphism in most [L2MX2] complexes, confirming the importance of coordination chemistry in metal-mediated formation of liquid crystals. Single crystal X-ray structures have been determined for dihexadecyl 2,2,-bipyridyl-4,4,-dicarboxylatopalladium and -zinc dichloride derivatives. Both the metal centres and the ancillary ligands have been varied to use dipole coupling as a tool to control molecular architecture: thermal, as well as spectroscopic properties, depend strongly upon molecular dipolar interactions. Tunable red and blue emitters based on PdII and PtII, both in solution and in the solid state, have been obtained. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Ferromagnetism in [Mn(Cp*)2]+ -Derived Complexes: the "Miraculous" Stacking in [Mn(Cp*)2][Ni(dmit)2]EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 15 2003Christophe Faulmann Abstract The synthesis and characterisation (X-ray structure and magnetism) of metal complexes (Ni, Au) with the [Mn(Cp*)2]+ cation and the dmit2, and dmid2, ligands are reported. [Mn(Cp*)2][Ni(dmit)2] (1) and [Mn(Cp*)2][Au(dmit)2] (2) exhibit the same structural arrangement, built on stacks of [Ni(dmit)2], pairs separated by two [Mn(Cp*)2]+ cations, showing a ···D+D+A,A,D+D+A,A,··· motif. On the contrary, the dmid2, derivative [Mn(Cp*)2][Ni(dmid)2]·CH3CN (3) exhibits a totally different structure, built on mixed layers composed of one [Ni(dmid)2], unit separated by two [Mn(Cp*)2]+ cations, showing a ···D+D+A,D+D+A,···motif. The layers are separated from each other by perpendicular [Ni(dmid)2], units and solvent molecules. Compound 2 exhibits antiferromagnetic interactions, whereas 1 and 3 exhibit ferromagnetic interactions at low temperature. Moreover, as confirmed by AC and DC magnetic susceptibility measurements, 1 is a ferrimagnet, the first ever derived from a 1,2-bis-dithiolene ligand. The ferromagnetic interactions in 1 and 3 are explained using the McConnell I mechanism. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Bicolor Pixels from a Single Active Molecular Material by Surface-Tension-Driven Deposition,ADVANCED MATERIALS, Issue 12 2007I. Viola The fabrication of a green- and red-emitting pixel structure (see figure, scale bar 10,,m) by the single-step, surface-tension-driven assembly of a single luminescent thiophene-based molecular material is reported. The solid-state organization of the selected thiophene-based oligomer is controlled by exploiting the molecular structural arrangement, induced during a dewetting process and facilitated by the great conformational flexibility of the oligomer, typical of several substituted oligothiophenes. [source] Role of the Latent Transforming Growth Factor ,,Binding Protein 1 in Fibrillin-Containing Microfibrils in Bone Cells In Vitro and In VivoJOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2000Sarah L. Dallas Abstract Latent transforming growth factor ,,binding proteins (LTBPs) are extracellular matrix (ECM) proteins that bind latent transforming growth factor , (TGF-,) and influence its availability in bone and other connective tissues. LTBPs have homology with fibrillins and may have related functions as microfibrillar proteins. However, at present little is known about their structural arrangement in the ECM. By using antibodies against purified LTBP1, against a short peptide in LTBP1, and against epitope-tagged LTBP1 constructs, we have shown colocalization of LTBP1 and fibrillin 1 in microfibrillar structures in the ECM of cultured primary osteoblasts. Immunoelectron microscopy confirmed localization of LTBP1 to 10- to 12-nm microfibrils and suggested an ordered aggregation of LTBP1 into these structures. Early colocalization of LTBP1 with fibronectin suggested a role for fibronectin in the initial assembly of LTBP1 into the matrix; however, in more differentiated osteoblast cultures, LTBP1 and fibronectin 1 were found in distinct fibrillar networks. Overexpression of LTBP1 deletion constructs in osteoblast-like cells showed that N-terminal amino acids 67,467 were sufficient for incorporation into fibrillin-containing microfibrils and suggested that LTBP1 can be produced by cells distant from the site of fibril formation. In embryonic long bones in vivo, LTBP1 and fibrillin 1 colocalized at the surface of newly forming osteoid and bone. However, LTBP1-positive fibrils, which did not contain fibrillin 1, were present in cartilage matrix. These studies show that in addition to regulating TGF,1, LTBP1 may function as a structural component of connective tissue microfibrils. LTBP1 may therefore be a candidate gene for Marfan-related connective tissue disorders in which linkage to fibrillins has been excluded. [source] A possible molecular mechanism of hanatoxin binding-modified gating in voltage-gated K+ -channelsJOURNAL OF MOLECULAR RECOGNITION, Issue 6 2003Kuo-Long Lou Abstract While S4 is known as the voltage sensor in voltage-gated potassium channels, the carboxyl terminus of S3 (S3C) is of particular interest concerning the site for gating modifier toxins like hanatoxin. The thus derived helical secondary structural arrangement for S3C, as well as its surrounding environment, has since been intensively and vigorously debated. Our previous structural analysis based on molecular simulation has provided sufficient information to describe reasonable docking conformation and further experimental designs (Lou et al., 2002. J. Mol. Recognit. 15: 175,179). However, if one only relies on such information, more advanced structure,functional interpretations for the roles S3C may play in the modification of gating behavior upon toxin binding will remain unknown. In order to have better understanding of the molecular details regarding this issue, we have performed the docking simulation with the S3C sequence from the hanatoxin-insensitive K+ -channel, shaker, and analyzed the conformational changes resulting from such docking. Compared with other functional data from previous studies with respect to the proximity of the S3,S4 linker region, we suggested a significant movement of drk1 S3C, but not shaker S3C, in the direction presumably towards S4, which was comprehended as a possible factor interfering with S4 translocation during drk1 gating in the presence of toxin. In combination with the discussions for structural roles of the length of the S3,S4 linker, a possible molecular mechanism to illustrate the hanatoxin binding-modified gating is proposed. Copyright © 2003 John Wiley & Sons, Ltd. [source] Spermatozoal ultrastructure in three Atlantic solenocerid shrimps (Decapoda, Dendrobranchiata)JOURNAL OF MORPHOLOGY, Issue 3 2006Antonio Medina Abstract The spermatozoal ultrastructure in three solenocerid shrimps (Solenocera membranacea, S. africana, and Pleoticus muelleri) from different Atlantic locations was examined with the aim of increasing understanding of the phylogenetic relationships in the Dendrobranchiata. A considerable structural similarity between the sperm of these species and those of penaeid shrimps supports a close affinity between the Penaeidae and Solenoceridae. However, significant differences in the sperm morphology of the previously investigated sicyoniids (namely, a greater complexity of the acrosomal complex) suggest evolutionary separation of the Sicyoniidae from the assemblage Penaeidae-Solenoceridae. Two ultrastructural features distinguish the spermatozoa of the three studied solenocerids from penaeid sperm: 1) separation of the plasma and acrosome membranes at the base of the spike and anterior region of the cap, and 2) asymmetry of the acrosomal cap, which appears to be a synapomorphy of the group. No striking ultrastructural differences were found between the spermatozoa of the closely related species S. membranacea and S. africana, whereas a great number of morphological differences separate the spermatozoa of Pleoticus from those of Solenocera (e.g., shape of the acrosomal cap, structural arrangement of the contents of the whole acrosome vesicle, thickness and distribution of the cytoplasm, and external shape of the spike). J. Morphol. © 2005 Wiley-Liss, Inc. [source] The response of protist and metazoan communities in permeable pavement structures to high oil loadingsTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2005S. J. COUPE Permeable pavement structures (PPS) have been demonstrated to provide an efficient and sustainable method of controlling urban derived hydrocarbon contamination. Until recently, laboratory PPS mesocosm models have used crushed granite as the load bearing sub-base material. However, the use of virgin stone may not be the optimal choice of substrate, as this is not necessarily sustainable or cost effective in the long term when compared to the use of recycled materials. However, recycled materials such as waste concrete may change the environmental conditions in PPS mesocosms, and the characteristics of the eukaryotic community may become different from those which have been previously described. In the current experiment, granite and recycled concrete sub-base materials were compared for their ability to retain 900 g/m2 of clean mineral oil applied to the mesocosm surface. It was observed that, even at this very high oil loading, 99.95% of the applied oil was retained within granite and concrete-based structures, but the effluent was two pH units more alkaline in concrete mesocosms than granite. The eukaryotic microfauna in the effluent from both mesocosm types showed a ten-fold increase in protist abundance, and a doubling in the number of protist genera, compared with earlier work using only 18 g/m2 of applied oil. Five genera of testate amoebae not previously recorded in PPS were identified, these included Arcella, Assulina, Cryptodifflugia, Cyclopyxis and Difflugia in addition to the three genera observed previously using the lower oil application. Metazoan abundances increased from 1.5 × 101 organisms per ml using the lower oil loadings to 2.0 × 103/ml in the current experiment. Rotifers and nematodes were the most numerous, but tardigrades were also observed in both concrete and granite-based mesocosms. Despite the differences in effluent pH, it was apparent that there were only marginal differences in the eukaryotic microbiology of the two mesocosm types. This was thought to be due to the layered structural arrangement of the pavement and the location of the highly oil-retentive polypropylene geotextile and extensive biofilm layer positioned above the concrete sub-base. Work is now underway to find oil loadings that will adversely affect the abundance and diversity of eukaryotic organisms in PPS mesocosms. [source] How Crisis Shapes Change: New Perspectives on China's Political Economy during the Sino-Japanese War, 1937,19451HISTORY COMPASS (ELECTRONIC), Issue 4 2007Morris L. Bian This article surveys the recent literature on China's political economy during the Sino-Japanese War (1937,45). This literature reveals that the war-triggered sustained systemic crisis brought about the most intensive Nationalist state-building efforts, the danwei designation of political, economic, and administrative organizations, the expansion of state-owned industries and the decline of the private sector, the creation of a state enterprise system, and the formation of an ideology of developmental state. This literature suggests that the elements of post-1949 institutional and structural arrangements and ideological systems developed well before 1949. Therefore, the critical issue is no longer that of establishing institutional, structural, and ideological continuity between the Nationalist and Communist eras; instead, it rests in understanding why and how the Chinese Communists kept intact, built on, and expanded existing institutions, structures, and ideologies in certain key areas of political, economic, and administrative life. [source] MICROSTRUCTURAL AND RHEOLOGICAL PROPERTIES OF LOW-FAT STIRRED YOGHURTS MADE WITH SKIM MILK AND MULTIPLE EMULSIONSJOURNAL OF TEXTURE STUDIES, Issue 6 2009C. LOBATO-CALLEROS ABSTRACT This article focuses on the study of the dynamic rheological and structural properties developed in low-fat stirred yoghurts made with skim milk and multiple emulsions stabilized with carboxymethylcellulose (SYCMC) or amidated low methoxy pectin (SYALMP), in comparison with a full milk-fat stirred yoghurt control (SYMF). The SYALMP yoghurt exhibited greatest Tan,after 14 days of storage than the SYMF and SYCMC yoghurts. The SYALMP yoghurt presented the highest lacunarity value and was characterized by a structure composed of highly clusterized casein aggregates. In contrast, the SYCMC and SYMF yoghurts displayed lower lacunarity values and structures characterized by smaller casein clusters. Lower Tan,values were associated with lower lacunarity values. PRACTICAL APPLICATIONS Limited work has been done on stirred and set-style yoghurts, cheeses and, in general, dairy products, where milk-fat globules are substituted by skim milk combined with multiple emulsions containing polyunsaturated vegetable oils. As a result of this, multicomponent gels formation occurs (made up by milk proteins, polyunsaturated vegetable oils, emulsifiers, hydrocolloids and many possible other ingredients), which give rise to completely different structural arrangements that may display comparable mechanical-sensory properties with those exhibited by their full milk-fat counterparts, paving the way for the development of new healthier foods sensory and texturally acceptable to consumers. [source] Regulation of ADL6 activity by its associated molecular networkTHE PLANT JOURNAL, Issue 5 2002Bernard C.-H. Summary Plant dynamin-like proteins consist of a group of high molecular weight GTPase with diverse structural arrangements and cellular localizations. In addition, unlike animal dynamins, there was no evidence for the involvement of any plant dynamin-like protein in clathrin-mediated vesicle trafficking. In this study we demonstrate that ADL6 (Arabidopsis dynamin-like protein 6), due to its domain arrangement, behaves similarly to the animal dynamins. The association of ADL6 with clathrin-coated vesicles was demonstrated by co-fractionation and immunocytochemical studies. ADL6 also interacted via its C-terminus with ,-adaptin, an adaptor protein of clathrin-coated vesicles. Our results suggest that ADL6 participates in clathrin-mediated vesicle trafficking originating from the Golgi. In addition, our studies demonstrate that ADL6 intrinsic GTPase activity is regulated by its association with acidic phospholipids and an SH3 (Src homology 3)-containing protein. [source] Audit for Accountability in China: An Incomplete MissionAUSTRALIAN JOURNAL OF PUBLIC ADMINISTRATION, Issue 2009Ting Gong This article argues against the conventional wisdom that accountability is the raison d'être of auditing activities. Audit, admittedly, is a part of the accountability architecture as it contributes to the financial health of a government and the effective management of public money. This does not mean, however, that audit necessarily generates accountability. China's experience with establishing a power audit regime shows that without enabling goals, impartial structural arrangements, and effective procedures, auditing for accountability only remains an incomplete mission. [source] Synthesis of quadruplex-forming tetra-end-linked oligonucleotides: Effects of the linker size on quadruplex topology and stabilityBIOPOLYMERS, Issue 6 2009Giorgia Oliviero Abstract G-quadruplexes are characteristic structural arrangements of guanine-rich DNA sequences that abound in regions with relevant biological significance. These structures are highly polymorphic differing in the number and polarity of the strands, loop composition, and conformation. Furthermore, the cation species present in solution strongly influence the topology of the G-quadruplexes. Recently, we reported the synthesis and structural studies of new G-quadruplex forming oligodeoxynucleotides (ODNs) in which the 3,- and/or the 5,-ends of four ODN strands are linked together by a non-nucleotidic tetra-end-linker (TEL). These TEL-ODN analogs having the sequence TGGGGT are able to form parallel G-quadruplexes characterized by a remarkable high thermal stability. We report here an investigation about the influence of the reduction of the TEL size on the molecularity, topology, and stability of the resulting TEL-G-quadruplexes using a combination of circular dichroism (CD), CD melting, 1H NMR spectroscopy, gel electrophoresis, and molecular modeling data. We found that all TEL-(TGGGGT)4 analogs, regardless the TEL size and the structural orientation of the ODN branches, formed parallel TEL-G-quadruplexes. The molecular modeling studies appear to be consistent with the experimental CD and NMR data revealing that the G-quadruplexes formed by TEL-ODNs having the longer TEL (L1 - 4) are more stable than the corresponding G-quadruplexes having the shorter TEL (S1 - 4). The relative stability of S1 - 4 was also reported. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 466,477, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Collaboration between service users and professionals: Legitimate decisions in child protection , a Norwegian modelCHILD & FAMILY SOCIAL WORK, Issue 3 2005Elisabeth Willumsen ABSTRACT The aim of this study is to examine the conditions for achieving free and open communication in collaboration. The context is child protection where ,the best interest of the child' is at stake. First, a theoretical standard based on free and open communication and equal partnership (deliberation) is presented. Secondly, an explorative analysis is undertaken of the collaboration process between professionals and service users in two review groups regarding two young people, Jane and Tom, both of whom appear to have psychosocial ,problems, living, in, residential, care., Thirdly,, on, the, basis, of this analysis, recommendations on how to improve collaboration in review groups are made. The findings show that collaboration has several functions: formal decision-making, legitimate decision-making and learning. There is a need to clarify the purpose of collaboration and strengthen structural arrangements as well as develop guidelines for handling challenges at different levels. [source] | |||||||||||||||||||