Home About us Contact
|
Home About us Contact | ||
|
|
||
Scientific Point (scientific + point)
Selected Abstracts,-cell development: the role of intercellular signalsDIABETES OBESITY & METABOLISM, Issue 2008R. Scharfmann Understanding in detail how pancreatic endocrine cells develop is important for many reasons. From a scientific point of view, elucidation of such a complex process is a major challenge. From a more applied point of view, this may help us to better understand and treat specific forms of diabetes. Although a variety of therapeutic approaches are well validated, no cure for diabetes is available. Many arguments indicate that the development of new strategies to cure diabetic patients will require precise understanding of the way ,-cells form during development. This is obvious for a future cell therapy using ,-cells produced from embryonic stem cells. This also holds true for therapeutic approaches based on regenerative medicine. In this review, we summarize our current knowledge concerning pancreatic development and focus on the role of extracellular signals implicated in ,-cell development from pancreatic progenitors. [source] Investigations of humans in space: adequate from a scientific point of view?EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2000P. Bie No abstract is available for this article. [source] Anthropological and physicochemical investigation of the burnt remains of Tomb IX in the ,Sa Figu' hypogeal necropolis (Sassari, Italy) , Early Bronze AgeINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 2 2008G. Piga Abstract Excavations carried out in Tomb IX of the hypogeic necropolis of ,Sa Figu', near the village of Ittiri (Sassari, Italy), supplied burnt human bone remains and pottery unambiguously referred to the Early Bronze Age (characterised by the local culture of ,Bonnannaro'). Besides the anthropological study, we have investigated and evaluated the possibility of a funerary cremation practice in Sardinian pre-history, a subject that has previously not been considered from a scientific point of view. Making use of a calibration procedure based on X-ray diffraction (XRD) line-broadening analysis, related to the microstructural properties, it was possible to estimate the combustion temperature to which the fragmented bones were subjected. It was found that the studied bones reached temperatures varying from 400°C up to a maximum of 850°C. This spread of values suggested inhomogeneous combustion of the bones, which seems compatible with funerary cremation practices. Copyright © 2007 John Wiley & Sons, Ltd. [source] Stability of poly(N -propargylamide)s under ultraviolet irradiationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008Jianping Deng Abstract This article investigates the photostability of poly(N -propargylamide)s under different conditions, on the basis of which application research for this class of highly functional polymers can be performed. With helical polymer 1 [monomer: CCCH2NHCOCH(C2H5)2] taken as a representative, some affecting factors, including the ultraviolet (UV)-light intensity, presence of oxygen, far-UV and near-UV light, and temperature, were investigated. It was found that increasing the UV-light intensity accelerated the degradation of polymer 1. When oxygen was present, it also facilitated the degradation. Far-UV light rather than near-UV light played a predominant role in initiating the degradation of polymer main chains. Elevating the temperature of the polymer solution during UV irradiation made the degradation accelerate. Storing the polymer under weak UV light, in the absence of oxygen, and at a low temperature was favorable for keeping the polymer stable. These findings are important not only from a scientific point of view but especially for developing practical applications of this type of polymer on the basis of its photodegradability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Grafting of polyolefins with maleic anhydride: alchemy or technology?MACROMOLECULAR SYMPOSIA, Issue 1 2003Martin van Duin Abstract Nowadays, the process of maleic anhydride (MA) grafting and the application of MA-grafted polyolefins are viewed as mature technologies. The chemistry and technology of modifying apolar polyolefins with the polar and reactive MA either in solution or in the melt were already explored as far back as the 1950s. Commercial applications exploit the improved adhesion of polyolefins to polar materials, both at the macroscopic scale and on the microscopic scale. However, it is hardly recognised that, from a scientific point of view, grafting has still a strong resemblance to alchemy. Both process and application technologies have been developed in a trial and error fashion. Only in the last decade the structure of MA-grafted polyolefins has been elucidated and attempts to "look" inside the extruder during grafting were only recently successful. The first steps towards the development of sound chemical models are currently made. An overview will be given of the progress made in the various areas mentioned. [source] Use of Renewable Raw Materials in the Chemical Industry , Beyond Sugar and StarchCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 5 2008K. Muffler Abstract Classical energy sources such as petroleum oil and natural gas make up the fundamental materials on which modern industrial chemical parks are based. According to the finite availability of these consuetudinary resources and due to the increasing demand for energy from developing countries and the related rise in prices of oil and natural gas, renewable resources must be considered as valuable alternatives. Discussions about climate change with regard to alternatives in energy production are preceded very fervidly but alternatives have to be examined from a matter-of-fact based economic and scientific point of view. Therefore, this review is focussed on alternative sources such as wood and other agricultural residues with respect to their potential as future energy resources as well as building blocks for chemical synthesis processes. [source] Assessment of risk of venous thromboembolism and its possible prevention in psychiatric patientsPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 1 2008Radovan Malư md Aims:, The aim of the present study was to compile a specific algorithm of prevention of venous thromboembolism in hospitalized psychiatric patients because this specific issue has not been addressed sufficiently in the literature. Methods:, The computer database MEDLINE was searched using key words (schizophrenia OR depression OR bipolar) AND (antipsychotic OR antidepressant) AND (venous thromboembolism OR pulmonary embolism) AND (prevention OR prophylaxis) in 2006. Results:, Based on the literature regarding non-surgical and surgical patients with respect to specificities in mental disorders (obesity induced with psychotropic drugs, possible catatonia, physical restraint, potential dehydration, antipsychotic treatment), a scoring system and a synoptic algorithm of prevention of venous thromboembolism modified for hospitalized psychiatric patients, were suggested. Conclusions:, According to the authors' knowledge this is the first attempt to establish such guidelines exclusively in psychiatry. Individual preventative clinical measures are suggested, ranging from regular physical exercise of lower extremities to repeated parenteral application of high doses of heparin tailored to every patient's risk for venous thromboembolism. Economic data support implementation of a proposed decision procedure into psychiatric clinical practice. Prospective discussion of its international applicability would be beneficial from both the clinical and the scientific points of view. [source] | |||||||||||||