Application of virtual reality technology in simulation of automated workplaces

S pojavom visoko razlučive grafike, brzog računanja, te dobre interakcije uređaja s korisnikom, tehnologija virtualne stvarnosti (VS) u posljednjih nekoliko godina je jedna od glavnih tehnologija. Važan koncept koji predstavlja VS je sustav predočavanja, koji se odnosi na osjećaj potpune uronjenosti u trodimenzijskom računalno generiranom okruženju, pomoću koje se iz korisničke perspektive uvelike olakšava praćenje. Glavna prednost korištenja virtualne stvarnosti očituje se kao mogućnost stvaranja i simuliranja novih tehnoloških jedinica prije njihove realizacije. Ovo može doprinijeti povećanju sigurnosti, povećanju ergonomije i smanjenju troškova. Virtualni model radnog mjesta mogao bi otkriti skrivene pogreške koje se eliminiraju, a koje bi u kasnijoj fazi na tom radnom mjestu mogle uzrokovati velike poteškoće.With the advent of high-resolution graphics, high-speed computing, and user interaction devices, virtual reality (VR) has emerged as a major new technol­ogy in recent years. An important new concept introduced by many VR sys­tems is immersion, which refers to the feeling of complete immersion in a three-dimensional computer-generated environment by means of user-cen­tered perspective achieved through tracking the user. Main advantage of virtual reality application usage is the possibility of creation and simulation of new technological unit before its realization. This may contribute to increasing of safety and ergonomics and decreasing of economical aspects of new proposed unit. Virtual model of proposed workcell could reveal hidden errors whose elimination in later stage of the new workcell creation should cause great difficulties

Cell-free formation of protease-resistant prion protein

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1996.Includes bibliographical references.by David A. Kocisko.Ph.D

Influence of cryorolling on properties of L-PBF 316l stainless steel tested at 298K and 77K

The goal of the present work is to evaluate mechanical properties and to analyse the microstructure of 316L stainless steel produced by Laser Powder Bed Fusion (L-PBF) follow by rolling with different thickness reduction under ambient and cryogenic conditions. The samples before rolling were heat treated. The static tensile test was realized at ambient and cryogenic (77K) conditions. The L-PBF powder metal production technology approved that is a key technology in the additive manufacturing (AM) area, especially for metal powder materials. Mechanical properties tested at 298K and 77K shows that the application of various thermo-deformation rolling conditions increases of strength properties. Achieved mechanical properties are comparable to conventional bulk materials. The strength properties after the rolling under ambient and cryogenic conditions were significantly increased

Intracerebral Infusion of Antisense Oligonucleotides Into Prion-infected Mice

Mice deficient for the cellular prion protein (PrPC) do not develop prion disease; accordingly, gene-based strategies to diminish PrPC expression are of interest. We synthesized a series of chemically modified antisense oligonucleotides (ASOs) targeted against mouse Prnp messenger RNA (mRNA) and identified those that were most effective in decreasing PrPC expression. Those ASOs were also evaluated in scrapie-infected cultured cells (ScN2a) for their efficacy in diminishing the levels of the disease-causing prion protein (PrPSc). When the optimal ASO was infused intracerebrally into FVB mice over a 14-day period beginning 1 day after infection with the Rocky Mountain Laboratory (RML) strain of mouse prions, a prolongation of the incubation period of almost 2 months was observed. Whether ASOs can be used to develop an effective therapy for patients dying of Creutzfeldt–Jakob disease remains to be established

Synthetic prions generated in vitro are similar to a newly identified subpopulation of PrPSc from sporadic Creutzfeldt-Jakob disease

In recent studies, the amyloid form of recombinant prion protein (PrP) encompassing residues 89–230 (rPrP 89-230) produced in vitro induced transmissible prion disease in mice. These studies showed that unlike “classical” PrPSc produced in vivo, the amyloid fibrils generated in vitro were more proteinase-K sensitive. Here we demonstrate that the amyloid form contains a proteinase K-resistant core composed only of residues 152/153–230 and 162–230. The PK-resistant fragments of the amyloid form are similar to those observed upon PK digestion of a minor subpopulation of PrPSc recently identified in patients with sporadic Creutzfeldt-Jakob disease (CJD). Remarkably, this core is sufficient for self-propagating activity in vitro and preserves a β-sheet-rich fibrillar structure. Full-length recombinant PrP 23-230, however, generates two subpopulations of amyloid in vitro: One is similar to the minor subpopulation of PrPSc, and the other to classical PrPSc. Since no cellular factors or templates were used for generation of the amyloid fibrils in vitro, we speculate that formation of the subpopulation of PrPSc with a short PK-resistant C-terminal region reflects an intrinsic property of PrP rather than the influence of cellular environments and/or cofactors. Our work significantly increases our understanding of the biochemical nature of prion infectious agents and provides a fundamental insight into the mechanisms of prions biogenesis

Aging behavior of Al-Li-(Cu, Mg) alloys processed by different deformation methods

Structural features and aging behavior of Alsingle bondLi, Al-Li-Cu and Al-Li-Mg alloys under different equivalent strains (ε ) were investigated. Following solid-solution treatment, high-pressure torsion (HPT), asymmetric rolling (ASR) and cold rolling (CR) were adopted to introduce high, middle and low amount of strains to Al-Li-(Cu, Mg) alloys. After deformation, for the HPT processed alloys under high equivalent strains, the highest as-deformed hardness was obtained. Transmission electron microscopy (TEM) revealed that the grain size was refined to 210 nm, 120 nm and 150 nm, respectively. single bond Under severe plastic deformation condition (ε > 30), the Alsingle bondLi alloy lost age-hardenability, however, the aging of the asymmetric rolled Alsingle bondLi alloys increased the hardness further and the highest hardness was obtained in this alloy. For the Al-Li-Cu and Al-Li-Mg alloys, a further increase in hardness was achieved by aging the as-deformed alloys, regardless of the equivalent strains. Meanwhile, the peak hardness increases with increasing the equivalent strains. During aging treatment, the behavior of the precipitates was discussed in the present work

Virtools and its Application in MOCAP and Creation of the Scripts for Animation of Models

In this progress period technicians and companies very often need to simulate some events such as people walking or moving some objects from one place to another. This contribution is focused on one kind of virtual reality (VR) - MOCAP (Motion Capture) and on the creation of graphical scripts for the animation of models. VR is used also in the process of workplace design. Firstly, the workplace is designed and prior to its real building there are different conditions simulated. Once the manufactory is optimally designed, the realization of its building starts. VR has a very important role in these stages, because it can bring significant financial savings. The result of this simulation is a workplace, which makes provision for ergonomic requirements as badly designed workplace increases additional costs and assembling time. Currently, most companies try to prepare the projects of new products by simulations and analyses rather than assumptions or conjecture

influence of cryorolling on properties of l pbf 316l stainless steel tested at 298k and 77k

The goal of the present work is to evaluate mechanical properties and to analyse the microstructure of 316L stainless steel produced by Laser Powder Bed Fusion (L-PBF) follow by rolling with different thickness reduction under ambient and cryogenic conditions. The samples before rolling were heat treated. The static tensile test was realized at ambient and cryogenic (77K) conditions. The L-PBF powder metal production technology approved that is a key technology in the AM area, especially for metal powder materials. Mechanical properties tested at 298K and 77K shows that the application of various thermo-deformation rolling conditions increases of strength properties. Achieved mechanical properties are comparable to conventional bulk materials. The strength properties after the rolling under ambient and cryogenic conditions were significantly increased.</p

Molecular dynamics studies on the NMR and X-ray structures of rabbit prion protein wild-type and mutants

Prion diseases are invariably fatal and highly infectious neurodegenerative diseases that affect a wide variety of mammalian species such as sheep, goats, mice, humans, chimpanzees, hamsters, cattle, elks, deer, minks, cats, chicken, pigs, turtles, etc. These neurodegenerative diseases are caused by the conversion from a soluble normal cellular protein into insoluble abnormally folded infectious prions and the conversion is believed to involve conformational change from a predominantly alpha-helical protein to one rich in beta-sheet structure. Such conformational changes may be amenable to study by molecular dynamics (MD) techniques. For rabbits, classical studies show they have a low susceptibility to be infected, but in 2012 it was reported that rabbit prion can be generated (though not directly) and the rabbit prion is infectious and transmissible (Proceedings of the National Academy of Sciences USA 109(13): 5080-5). This paper studies the NMR and X-ray molecular structures of rabbit prion protein wild-type and mutants by MD techniques, in order to understand the specific mechanism of rabbit prion protein and rabbit prions.Comment: (The 2nd version of arXiv1304.7633

Characterization of 2′-fluoro-RNA aptamers that bind preferentially to disease-associated conformations of prion protein and inhibit conversion

We have isolated artificial ligands or aptamers for infectious prions in order to investigate conformational aspects of prion pathogenesis. The aptamers are 2'-fluoro-modified RNA produced by in vitro selection from a large, randomized library. One of these ligands (aptamer SAF-93) had more than 10-fold higher affinity for PrPSc than for recombinant PrPC and inhibited the accumulation of PrPres in near physiological cell-free conversion assay. To understand the molecular basis of these properties and to distinguish specific from nonspecific aptamer-PrP interactions, we studied deletion mutants of bovine PrP in denatured, alpha-helix-rich and beta-sheet-rich forms. We provide evidence that, like scrapie-associated fibrils (SAF), the beta-oligomer of PrP bound to SAF-93 with at least 10-fold higher affinity than did the alpha-form. This differential affinity could be explained by the existence of two binding sites within the PrP molecule. Site 1 lies within residues 23-110 in the unstructured N terminus and is a nonspecific RNA binding site found in all forms of PrP. The region between residue 90 and 110 forms a hinge region that is occluded in the alpha-rich form of PrP but becomes exposed in the denatured form of PrP. Site 2 lies in the region C-terminal of residue 110. This site is beta-sheet conformation-specific and is not recognized by control RNAs. Taken together, these data provide for the first time a specific ligand for a disease conformation-associated site in a region of PrP critical for conformational conversion. This aptamer could provide tools for the further analysis of the processes of PrP misfolding during prion disease and leads for the development of diagnostic and therapeutic approaches to TSEs