358 research outputs found
Universal Decimal Classification : a Unique Scheme with its Origin,Development and Credibility
this article deals with the emergence, background history and usages of the Universal Decimal Classification scheme(UDC).It also speaks about the influence of the very scheme over different languages in different countries.It focuses also on the scheme’s acceptability and flexibility to the universal users.This article discusses the scheme’s inclination to be transformed into a machine readable version to compete with other schemes full-fledgedly.Here, the significance of classification scheme in a multilingual atmosphere  is highlighted and future advancements delineated
Dehydrogenation studies in the field of indole alkaloids
Two methods of dehydrogenation have been used for the oxidation of variously ring E-substituted yohimbine- and ajmalicine-type indole alkaloids;The first method, palladium-maleic acid dehydrogenation, produces ring C tetradehydro compounds and can be used for differentiating pseudo compounds from epiallo compounds. The second method, mercuric acetate oxidation, produces 3-dehydro compounds;By the use of the first method the stereochemistry of several indole alkaloids was elucidated;Infrared spectra in the C-H stretching region (3.4--3.7mu) have been used for differentiating between C3 epimers of indole alkaloids;Structures were proposed for several new compounds derived by oxidation or reduction of indole alkaloids or their derivatives;The stereochemistry of various reduction methods was discussed
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Stereometric Design for Desk-Top SFF Fabrication
Solid Freeform Fabrication (SFF) technologies refer to the fabrication of physical parts directly from
computer based solid models described by STL (Stereo Lithography) or VRML (Virtual Reality Modeling
Language) files generated by Computer-Aided Design (CAD) systems. Most of the SFF processes produce parts
by building them layer by layer using a row by row pattern, though it is possible to build the part using other
patterns. The SFF technology represents a challenge to designers who, in addition to making decisions
concerning optimum shape and functionality of the entire part, have'to take under consideration several other
manufacturing factors. These factors cover a wide range of technical issues such as Computer-Aided Design
model generation, part description and model slicing files, laser path files, precision of part design, rendering
patterns, manufacturing tolerances, thermal expansion and residual stress phenomena.
This paper investigates the effect of rendering patterns on the integrity, material characteristics and
mechanical properties of the parts prepared by a desk-top SFF device using diode lasers. Fe - Bronze (Cu - Sn)
premixed metal powders were used as the starting material. The particle size was about 100 /lm to 200 /lm.
Density, tensile strength and microstructure of the parts prepared using different rendering patterns were
characterized. The results were analyzed to seek optimal rendering patterns. It was noticed that the samples
were strong along the laser scanning direction, while they were weak perpendicular to the scanning direction.
These results suggest that the laser scanning patterns should be designed to minimize the warping and maximize
the strength of the part in the direction depending on the part's function.Mechanical Engineerin
Single-Molecule AFM Force Spectroscopy Reveals the Difference in the Folding Patterns between Amyloid β 40 and 42 Within Dimers
Mechanism of amyloid β-protein dimerization determined using single-molecule AFM force spectroscopy.
Aβ42 and Aβ40 are the two primary alloforms of human amyloid β-protein (Aβ). The two additional C-terminal residues of Aβ42 result in elevated neurotoxicity compared with Aβ40, but the molecular mechanism underlying this effect remains unclear. Here, we used single-molecule force microscopy to characterize interpeptide interactions for Aβ42 and Aβ40 and corresponding mutants. We discovered a dramatic difference in the interaction patterns of Aβ42 and Aβ40 monomers within dimers. Although the sequence difference between the two peptides is at the C-termini, the N-terminal segment plays a key role in the peptide interaction in the dimers. This is an unexpected finding as N-terminal was considered as disordered segment with no effect on the Aβ peptide aggregation. These novel properties of Aβ proteins suggests that the stabilization of N-terminal interactions is a switch in redirecting of amyloids form the neurotoxic aggregation pathway, opening a novel avenue for the disease preventions and treatments
Mechanism of amyloid β-protein dimerization determined using single-molecule AFM force spectroscopy.
Aβ42 and Aβ40 are the two primary alloforms of human amyloid β-protein (Aβ). The two additional C-terminal residues of Aβ42 result in elevated neurotoxicity compared with Aβ40, but the molecular mechanism underlying this effect remains unclear. Here, we used single-molecule force microscopy to characterize interpeptide interactions for Aβ42 and Aβ40 and corresponding mutants. We discovered a dramatic difference in the interaction patterns of Aβ42 and Aβ40 monomers within dimers. Although the sequence difference between the two peptides is at the C-termini, the N-terminal segment plays a key role in the peptide interaction in the dimers. This is an unexpected finding as N-terminal was considered as disordered segment with no effect on the Aβ peptide aggregation. These novel properties of Aβ proteins suggests that the stabilization of N-terminal interactions is a switch in redirecting of amyloids form the neurotoxic aggregation pathway, opening a novel avenue for the disease preventions and treatments
AN ENERGY EFFICIENT, MINIMALLY INTRUSIVE MULTI-SENSOR INTELLIGENT SYSTEM FOR HEALTH MONITORING OF ELDERLY PEOPLE
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