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Numerous Modifications (numerous + modifications)
Selected AbstractsSolid-phase synthesis of a dendritic peptide related to a retinoblastoma protein fragment utilizing a combined boc- and fmoc-chemistry approachJOURNAL OF PEPTIDE SCIENCE, Issue 5 2001Vittoria Cavallaro Abstract Dendritic peptides, often presented as multiple antigen peptides (MAPs), are widely used in immunological-based fields of research, although their synthesis can be extremely challenging. In this paper, a tetrameric dendritic MAP-like presentation of the retinoblastoma protein [649-654] sequence (4RB649-654) has been prepared using solid-phase peptide synthesis (SPPS) methods. During the synthesis of this dendritic molecule, numerous modifications to the synthetic protocols were examined. These modifications included the introduction of a combination Boc- and Fmoc-chemistry approach and also the use of 1,8-diazabicyclo[5.4.0]-undec-7-ene as a Fmoc-deprotection agent. The use in combination of Boc- and Fmoc-based synthetic strategies resulted in the production of the desired peptide molecule, 4RB649-654, in high purity and acceptable yields following purification by reversed phase HPLC. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd. [source] Micro-Raman spectroscopic study of artificially aged natural and dyed woolJOURNAL OF RAMAN SPECTROSCOPY, Issue 5 2008Brenda Doherty Abstract The objective of this study was to evaluate the use of micro-Raman spectroscopy as a non-invasive vibrational spectroscopic technique applied to the examination of wool samples, which may be applied to textile materials of cultural heritage interest. In this work, a selection of wool materials were primarily investigated in their unaged states through the utility of a natural wool reference together with selected samples dyed with different natural colorants, namely woad, weld and madder. The identification of the main modes of vibration of the wool fibre keratin was assessed in all the samples, which aided the determination of the changes within the protein structure, in particular, through the cysteine and peptide cross-linkages brought about by the addition of the dyes that can produce effects similar to degradation. The dye too was assessed importantly to enable its identification through its characteristic scattering or fluorescence emissions on a woollen matrix, as well as to ascertain whether a uniform covering across the surface of the wool was achieved or not. Regarding the artificial degradation of the samples it was possible to observe numerous modifications within the molecular structure of the wool, in particular, within the amide I, CH bending, amide III and S-S stretchings along with the physical photo-yellowing of fibres given by the presence of lipids dispersed across the surface of the wool. The effects of ageing on the dyed samples were also investigated, indicating that many of the bands relative to the colorants were still present, yet so too were numerous vibrations from the wool that also indicated a certain level of stress and degradation to the underlying wool. Copyright © 2008 John Wiley & Sons, Ltd. [source] Modified technique of ureteroureterostomy in rat kidney transplantationMICROSURGERY, Issue 4 2004Alexander Pietsch Dr. Med. Different strain combinations of rats are available to study immunological and transplant-related problems in the models of kidney transplantation. Although numerous modifications of surgical techniques for ureteric reconstruction are evaluated in order to reduce complications and to extend long-term survival, ureteric complications still occur frequently, especially when the difference in diameter of both donor and host ureters is disproportionate. Instead of using the current nonsplinted ureteroureterostomy (method A), a versatile and rapid technical modification (method B) was developed to perform reconstruction of ureters with disproportionate diameters. The overall incidence of ureteric complications was 80% (8/10) using method A, whereas this rate was significantly reduced to 15% (3/20) using method B (P < 0.001). Our modification proves the feasibility of nonsplinted ureteroureterostomy in a technical, highly demanding rat model of kidney transplantation with an acceptable rate of ureteric complication, considering the disproportionate difference in diameter between the host and donor ureters. © 2004 Wiley-Liss, Inc. [source] Atomvolumen, Packungsdichte der Atome und chemische Bindung in nichtmetallischen ElementenACTA CRYSTALLOGRAPHICA SECTION B, Issue 4 2007M. Trömel The atomic volume of crystalline elements is largely determined by the packing density of atoms in the respective modification. The determination of packing density is improved by assuming that the atomic distances depend on bond valences according to Pauling's equation. With the additional assumption of equal valence in different modifications, the experimental atomic volume of an element in any given structure is reduced to its volume in close-packed structures, e.g. f.c.c. The ratio of this reduced atomic volume and the experimental atomic volume is a measure of packing density. Reduced atomic volumes of C, Si, Ge, P, As, S and Se, as calculated from different modifications, correspond in most cases to within less than ±1% for each element, even if calculated from extremely different structures like diamond and buckminsterfullerene in the case of carbon, or from numerous modifications of sulfur with annular molecules of different sizes. Exceptions (graphite, white phosphorus, tin and selenium) indicate deviating valences. [source] Front and Back Covers, Volume 25, Number 3.ANTHROPOLOGY TODAY, Issue 3 2009June 200 Front & back cover caption, volume 25 issue 3 Front & back cover HERITAGE PROTECTION Created in the aftermath of World War II, UNESCO was mandated to engage in a worldwide educational campaign aimed at establishing the conditions for lasting peace. This involved working out and disseminating a new world view based on a revised conception of human diversity. The founders of UNESCO argued that prejudice relating to human diversity is the main cause of war, and hoped that a radical modification of the existing vision of that diversity would help to guarantee of peace. Over the 60 years of its history UNESCO's doctrine has been subject to numerous modifications. Initially, cultural diversity was often described in terms of unequal economic progress and presented as an obstacle to be overcome. But in the 1960s ,progress', and the resulting cultural homogenization, began to be considered a major threat to human diversity, particularly diversity of culture. Co-ordinated by UNESCO, the international salvage of the Abu Simbel temples, threatened with submersion in Lake Nasser, became a symbol of a new moral obligation, incumbent upon all humans, to safeguard a common ,world heritage' (exemplified in the images on the back and front covers of this issue). Over the last decade, the notion of common heritage of humanity has been extended to all expressions of cultural traditions, thought to be endangered by the deleterious effects of globalization. UNESCO has chosen to put its support behind local identities and the right of the minorities to conserve their traditional differences. Alongside the principle of the equality of individuals, UNESCO now also upholds the equality of cultures, suggesting that the charter of human rights needs to be supplemented by a charter of cultural rights. The major challenge to UNESCO's current ideology is the compatibility of universal human rights with particular cultural rights. If all traditions deserve to be protected, should this privilege be bestowed equally on masterpieces of the past as on traditional practices. Wearing the burqa need not be controversial, but what about practices like genital mutilation or ,honour killings'? As Wiktor Stoczkowski argues in his article, such issues are intensely anthropological challenges deserving our attention. [source] | ||||||||||