Recent advances in 3D printing of biomaterials.

3D Printing promises to produce complex biomedical devices according to computer design using patient-specific anatomical data. Since its initial use as pre-surgical visualization models and tooling molds, 3D Printing has slowly evolved to create one-of-a-kind devices, implants, scaffolds for tissue engineering, diagnostic platforms, and drug delivery systems. Fueled by the recent explosion in public interest and access to affordable printers, there is renewed interest to combine stem cells with custom 3D scaffolds for personalized regenerative medicine. Before 3D Printing can be used routinely for the regeneration of complex tissues (e.g. bone, cartilage, muscles, vessels, nerves in the craniomaxillofacial complex), and complex organs with intricate 3D microarchitecture (e.g. liver, lymphoid organs), several technological limitations must be addressed. In this review, the major materials and technology advances within the last five years for each of the common 3D Printing technologies (Three Dimensional Printing, Fused Deposition Modeling, Selective Laser Sintering, Stereolithography, and 3D Plotting/Direct-Write/Bioprinting) are described. Examples are highlighted to illustrate progress of each technology in tissue engineering, and key limitations are identified to motivate future research and advance this fascinating field of advanced manufacturing

Novel hydrogels based on polysaccharides for soft tissue regeneration: preparation and characterization

Předložená diplomová práce se zabývá přípravou, síťováním a fyzikálně-chemickou charakterizací hydrogelů na bázi polysacharidů. Cílem práce bylo vyvinout elastické filmy, které by mohly být použity pro vlhké hojení ran. Teoretická část shrnuje současné způsoby regenerace měkkých tkání a jejích náhradách (ať už se jedná o přírodní nebo syntetické materiály). Zároveň jsou zdůrazněny základní informace o přírodních polysacharidech (chemická struktura, rozpustnost, tepelná a pH stabilita atd.), jejich modifikace a chemické síťování. Experimentální část je zaměřena na modifikaci přírodní gumy Karaya tak, aby transparentní hydrogely měly nastavitelnou hydrolytickou stabilitu. Vzorky byly analyzovány pomocí FTIR, TGA následované vyhodnocením bobtnání a hydrolytické degradace. Z výsledků vyplynulo, že chemická modifikace zvýšila stabilizaci elastického filmu z přírodního polysacharidu ve vodě až na 25 dní. Díky řízené degradaci a vysoké absorpci vody (85 - 96%) jsou tyto nové hydrogely využitelné především pro vlhké hojení ran (např. popálenin).Presented diploma thesis deals with preparation, crosslinking and physico-chemical characterization of natural polysaccharide-based hydrogels. The aim of the work was to evolve elastic thin films with potential application for moist wound healing. The theoretical part summarizes the state-of-art about regeneration of soft tissues and their substitutes (synthetic or nature). There are pointed out the basic information about natural polysaccharide gums (chemical structure, solubility, heat and pH stability etc.), its modification and chemical crosslinking. The experimental part is focused on the modification of natural gum Karaya in order to make transparent hydrogels with adjustable hydrolytical stability. Samples were analyzed by FTIR, TGA followed by evaluation of swelling properties and hydrolytical degradation. Based on the results, chemical modification helped to stabilize polysaccharide hydrogels in water up to 25 days which is useful mainly for moist wound healing (e.g. after burns) because of high values of water uptake (from 85 up to 96%).

White paper on the future of plasma science and technology in plastics and textiles

This is the peer reviewed version of the following article: “Uros, C., Walsh, J., Cernák, M., Labay, C., Canal, J.M., Canal, C. (2019) White paper on the future of plasma science and technology in plastics and textiles. Plasma processes and polymers, 16 1 which has been published in final form at [doi: 10.1002/ppap.201700228]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."This white paper considers the future of plasma science and technology related to the manufacturing and modifications of plastics and textiles, summarizing existing efforts and the current state‐of‐art for major topics related to plasma processing techniques. It draws on the frontier of plasma technologies in order to see beyond and identify the grand challenges which we face in the following 5–10 years. To progress and move the frontier forward, the paper highlights the major enabling technologies and topics related to the design of surfaces, coatings and materials with non‐equilibrium plasmas. The aim is to progress the field of plastics and textile production using advanced plasma processing as the key enabling technology which is environmentally friendly, cost efficient, and offers high‐speed processingPeer ReviewedPostprint (author's final draft

Space biology initiative program definition review. Trade study 2: Prototype utilization in the development of space biology hardware

The objective was to define the factors which space flight hardware developers and planners should consider when determining: (1) the number of hardware units required to support program; (2) design level of the units; and (3) most efficient means of utilization of the units. The analysis considered technology risk, maintainability, reliability, and safety design requirements for achieving the delivery of highest quality flight hardware. Relative cost impacts of the utilization of prototyping were identified. The development of Space Biology Initiative research hardware will involve intertwined hardware/software activities. Experience has shown that software development can be an expensive portion of a system design program. While software prototyping could imply the development of a significantly different end item, an operational system prototype must be considered to be a combination of software and hardware. Hundreds of factors were identified that could be considered in determining the quantity and types of prototypes that should be constructed. In developing the decision models, these factors were combined and reduced by approximately ten-to-one in order to develop a manageable structure based on the major determining factors. The Baseline SBI hardware list of Appendix D was examined and reviewed in detail; however, from the facts available it was impossible to identify the exact types and quantities of prototypes required for each of these items. Although the factors that must be considered could be enumerated for each of these pieces of equipment, the exact status and state of development of the equipment is variable and uncertain at this time

DeSyRe: on-Demand System Reliability

The DeSyRe project builds on-demand adaptive and reliable Systems-on-Chips (SoCs). As fabrication technology scales down, chips are becoming less reliable, thereby incurring increased power and performance costs for fault tolerance. To make matters worse, power density is becoming a significant limiting factor in SoC design, in general. In the face of such changes in the technological landscape, current solutions for fault tolerance are expected to introduce excessive overheads in future systems. Moreover, attempting to design and manufacture a totally defect and fault-free system, would impact heavily, even prohibitively, the design, manufacturing, and testing costs, as well as the system performance and power consumption. In this context, DeSyRe delivers a new generation of systems that are reliable by design at well-balanced power, performance, and design costs. In our attempt to reduce the overheads of fault-tolerance, only a small fraction of the chip is built to be fault-free. This fault-free part is then employed to manage the remaining fault-prone resources of the SoC. The DeSyRe framework is applied to two medical systems with high safety requirements (measured using the IEC 61508 functional safety standard) and tight power and performance constraints

An Approach for Supporting Ad-hoc Modifications in Distributed Workflow Management Systems

Supporting enterprise-wide or even cross-organizational business processes is a characteristic challenge for any workflow management system (WfMS). Scalability at the presence of high loads as well as the capability to dynamically modify running workflow (WF) instances (e.g., to cope with exceptional situations) are essential requirements in this context. Should the latter one, in particular, not be met, the WfMS will not have the necessary flexibility to cover the wide range of process-oriented applications deployed in many organizations. Scalability and flexibility have, for the most part, been treated separately in the relevant literature thus far. Even though they are basic needs for a WfMS, the requirements related with them are totally different. To achieve satisfactory scalability, on the one hand, the system needs to be designed such that a workflow instance can be controlled by several WF servers that are as independent from each other as possible. Yet dynamic WF modifications, on the other hand, necessitate a (logical) central control instance which knows the current and global state of a WF instance. For the first time, this paper presents methods which allow ad-hoc modifications (e.g., to insert, delete, or shift steps) to be performed in a distributed WfMS; i.e., in a WfMS with partitioned WF execution graphs and distributed WF control. It is especially noteworthy that the system succeeds in realizing the full functionality as given in the central case while, at the same time, achieving extremely favorable behavior with respect to communication costs