Cartilage constructs engineered from chondrocytes overexpressing IGF-I improve the repair of osteochondral defects in a rabbit model.

PubMed

Madry, H; Kaul, G; Zurakowski, D; Vunjak-Novakovic, G; Cucchiarini, M

2013-04-16

Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes overexpressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-overexpressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects.

CARTILAGE CONSTRUCTS ENGINEERED FROM CHONDROCYTES OVEREXPRESSING IGF-I IMPROVE THE REPAIR OF OSTEOCHONDRAL DEFECTS IN A RABBIT MODEL

PubMed Central

Madry, Henning; Kaul, Gunter; Zurakowski, David; Vunjak-Novakovic, Gordana; Cucchiarini, Magali

2015-01-01

Tissue engineering combined with gene therapy is a promising approach for promoting articular cartilage repair. Here, we tested the hypothesis that engineered cartilage with chondrocytes over expressing a human insulin-like growth factor I (IGF-I) gene can enhance the repair of osteochondral defects, in a manner dependent on the duration of cultivation. Genetically modified chondrocytes were cultured on biodegradable polyglycolic acid scaffolds in dynamic flow rotating bioreactors for either 10 or 28 d. The resulting cartilaginous constructs were implanted into osteochondral defects in rabbit knee joints. After 28 weeks of in vivo implantation, immunoreactivity to ß-gal was detectable in the repair tissue of defects that received lacZ constructs. Engineered cartilaginous constructs based on IGF-I-over expressing chondrocytes markedly improved osteochondral repair compared with control (lacZ) constructs. Moreover, IGF-I constructs cultivated for 28 d in vitro significantly promoted osteochondral repair vis-à-vis similar constructs cultivated for 10 d, leading to significantly decreased osteoarthritic changes in the cartilage adjacent to the defects. Hence, the combination of spatially defined overexpression of human IGF-I within a tissue-engineered construct and prolonged bioreactor cultivation resulted in most enhanced articular cartilage repair and reduction of osteoarthritic changes in the cartilage adjacent to the defect. Such genetically enhanced tissue engineering provides a versatile tool to evaluate potential therapeutic genes in vivo and to improve our comprehension of the development of the repair tissue within articular cartilage defects. Insights gained with additional exploration using this model may lead to more effective treatment options for acute cartilage defects. PMID:23588785

Biomaterials for Tissue Engineering

PubMed Central

Lee, Esther J.; Kasper, F. Kurtis; Mikos, Antonios G.

2013-01-01

Biomaterials serve as an integral component of tissue engineering. They are designed to provide architectural framework reminiscent of native extracellular matrix in order to encourage cell growth and eventual tissue regeneration. Bone and cartilage represent two distinct tissues with varying compositional and mechanical properties. Despite these differences, both meet at the osteochondral interface. This article presents an overview of current biomaterials employed in bone and cartilage applications, discusses some design considerations, and alludes to future prospects within this field of research. PMID:23820768

Characterization of Mesenchymal Stem Cell-Like Cells Derived From Human iPSCs via Neural Crest Development and Their Application for Osteochondral Repair

PubMed Central

Ikeya, Makoto; Yasui, Yukihiko; Ikeda, Yasutoshi; Ebina, Kosuke; Moriguchi, Yu; Shimomura, Kazunori; Hideki, Yoshikawa

2017-01-01

Mesenchymal stem cells (MSCs) derived from induced pluripotent stem cells (iPSCs) are a promising cell source for the repair of skeletal disorders. Recently, neural crest cells (NCCs) were reported to be effective for inducing mesenchymal progenitors, which have potential to differentiate into osteochondral lineages. Our aim was to investigate the feasibility of MSC-like cells originated from iPSCs via NCCs for osteochondral repair. Initially, MSC-like cells derived from iPSC-NCCs (iNCCs) were generated and characterized in vitro. These iNCC-derived MSC-like cells (iNCMSCs) exhibited a homogenous population and potential for osteochondral differentiation. No upregulation of pluripotent markers was detected during culture. Second, we implanted iNCMSC-derived tissue-engineered constructs into rat osteochondral defects without any preinduction for specific differentiation lineages. The implanted cells remained alive at the implanted site, whereas they failed to repair the defects, with only scarce development of osteochondral tissue in vivo. With regard to tumorigenesis, the implanted cells gradually disappeared and no malignant cells were detected throughout the 2-month follow-up. While this study did not show that iNCMSCs have efficacy for repair of osteochondral defects when implanted under undifferentiated conditions, iNCMSCs exhibited good chondrogenic potential in vitro under appropriate conditions. With further optimization, iNCMSCs may be a new source for tissue engineering of cartilage. PMID:28607560

Bioactive glass 13-93 as a subchondral substrate for tissue-engineered osteochondral constructs: a pilot study.

PubMed

Jayabalan, Prakash; Tan, Andrea R; Rahaman, Mohammed N; Bal, B Sonny; Hung, Clark T; Cook, James L

2011-10-01

Replacement of diseased areas of the joint with tissue-engineered osteochondral grafts has shown potential in the treatment of osteoarthritis. Bioactive glasses are candidates for the osseous analog of these grafts. (1) Does Bioactive Glass 13-93 (BG 13-93) as a subchondral substrate improve collagen and glycosaminoglycan production in a tissue-engineered cartilage layer? (2) Does BG 13-93 as a culture medium supplement increase the collagen and glycosaminoglycan production and improve the mechanical properties in a tissue-engineered cartilage layer? In Study 1, bioactive glass samples (n = 4) were attached to a chondrocyte-seeded agarose layer to form an osteochondral construct, cultured for 6 weeks, and compared to controls. In Study 2, bioactive glass samples (n = 5) were cocultured with cell-seeded agarose for 6 weeks. The cell-seeded agarose layer was exposed to BG 13-93 either continuously or for the first or last 2 weeks in culture or had no exposure. Osteochondral constructs with a BG 13-93 base had improved glycosaminoglycan deposition but less collagen II content. Agarose scaffolds that had a temporal exposure to BG 13-93 within the culture medium had improved mechanical and biochemical properties compared to continuous or no exposure. When used as a subchondral substrate, BG 13-93 did not improve biochemical properties compared to controls. However, as a culture medium supplement, BG 13-93 improved the biochemical and mechanical properties of a tissue-engineered cartilage layer. BG 13-93 may not be suitable in osteochondral constructs but could have potential as a medium supplement for neocartilage formation.

Challenges in engineering osteochondral tissue grafts with hierarchical structures.

PubMed

Gadjanski, Ivana; Vunjak-Novakovic, Gordana

2015-01-01

A major hurdle in treating osteochondral (OC) defects is the different healing abilities of two types of tissues involved - articular cartilage and subchondral bone. Biomimetic approaches to OC-construct engineering, based on recapitulation of biological principles of tissue development and regeneration, have potential for providing new treatments and advancing fundamental studies of OC tissue repair. This review on state of the art in hierarchical OC tissue graft engineering is focused on tissue engineering approaches designed to recapitulate the native milieu of cartilage and bone development. These biomimetic systems are discussed with relevance to bioreactor cultivation of clinically sized, anatomically shaped human cartilage/bone constructs with physiologic stratification and mechanical properties. The utility of engineered OC tissue constructs is evaluated for their use as grafts in regenerative medicine, and as high-fidelity models in biological research. A major challenge in engineering OC tissues is to generate a functionally integrated stratified cartilage-bone structure starting from one single population of mesenchymal cells, while incorporating perfusable vasculature into the bone, and in bone-cartilage interface. To this end, new generations of advanced scaffolds and bioreactors, implementation of mechanical loading regimens and harnessing of inflammatory responses of the host will likely drive the further progress.

Gellan Gum-Based Hydrogels for Osteochondral Repair.

PubMed

Costa, Lígia; Silva-Correia, Joana; Oliveira, J Miguel; Reis, Rui L

2018-01-01

Gellan gum (GG) is a widely explored natural polysaccharide that has been gaining attention in tissue engineering (TE) and regenerative medicine field, and more recently in osteochondral TE approaches. Taking advantage of its inherent features such as biocompatibility, biodegradability, similarity with the extracellular matrix and easy functionalization, GG-based hydrogels have been studied for their potential for cartilage and bone tissue regeneration. Several preclinical studies describe the successful outcome of GG in cartilage tissue engineering. By its turn, GG composites have also been proposed in several strategies to guide bone formation. The big challenge in osteochondral TE approaches is still to achieve cartilage and bone regeneration simultaneously through a unique integrated bifunctional construct. The potential of GG to be used as polymeric support to reach both bone and cartilage regeneration has been demonstrated. This chapter provides an overview of GG properties and the functionalization strategies employed to tailor its behaviour to a particular application. The use of GG in soft and hard tissues regeneration approaches, as well in osteochondral integrated TE strategies is also revised.

Challenges in engineering osteochondral tissue grafts with hierarchical structures Ivana Gadjanski, Gordana Vunjak Novakovic

PubMed Central

Gadjanski, Ivana; Vunjak-Novakovic, Gordana

2015-01-01

Introduction A major hurdle in treating osteochondral (OC) defects are the different healing abilities of two types of tissues involved - articular cartilage and subchondral bone. Biomimetic approaches to OC-construct-engineering, based on recapitulation of biological principles of tissue development and regeneration, have potential for providing new treatments and advancing fundamental studies of OC tissue repair. Areas covered This review on state of the art in hierarchical OC tissue graft engineering is focused on tissue engineering approaches designed to recapitulate the native milieu of cartilage and bone development. These biomimetic systems are discussed with relevance to bioreactor cultivation of clinically sized, anatomically shaped human cartilage/bone constructs with physiologic stratification and mechanical properties. The utility of engineered OC tissue constructs is evaluated for their use as grafts in regenerative medicine, and as high-fidelity models in biological research. Expert opinion A major challenge in engineering OC tissues is to generate a functionally integrated stratified cartilage-bone structure starting from one single population of mesenchymal cells, while incorporating perfusable vasculature into the bone, and in bone-cartilage interface. To this end, new generations of advanced scaffolds and bioreactors, implementation of mechanical loading regimens, and harnessing of inflammatory responses of the host will likely drive the further progress. PMID:26195329

Biological Response of Osteoblastic and Chondrogenic Cells to Graphene-Containing PCL/Bioactive Glass Bilayered Scaffolds for Osteochondral Tissue Engineering Applications.

PubMed

Deliormanlı, Aylin M; Atmaca, Harika

2018-05-25

Graphene-containing 13-93 bioactive glass and poly(ε-caprolactone)-based bilayer, electrically conductive scaffolds were prepared for osteochondral tissue repair. Biological response of osteoblastic MC3T3-E1 and chondrogenic ATDC5 cells to the composite scaffolds was assessed under mono-culture and co-culture conditions. Cytotoxicity was investigated using MTT assay, cartilage matrix production was evaluated by Alcian blue staining, and mineralization of both types of cells in the different culture systems was observed by Alizarin red S staining. Results showed that osteoblastic and chondrogenic cells utilized in the study did not show toxic response to the prepared scaffolds under mono-culture conditions and higher cell viability rates were obtained in co-culture conditions. Larger mineralized areas were determined under co-culture conditions and calcium deposition amount significantly increased compared with that in control group samples after 21 days. Additionally, the amount of glycosaminoglycans synthesized in co-culture was higher compared to mono-culture conditions. Electric stimulation applied under mono-culture conditions suppressed the viability of MC3T3-E1 cells whereas it enhanced the viability rates of ATDC5 cells. The study suggests that the designed bilayered osteochondral constructs have the potential for osteochondral defect repair.

Chitosan-Based Bilayer Hydroxyapatite Nanorod Composite Scaffolds for Osteochondral Regeneration

NASA Astrophysics Data System (ADS)

Swanson, Shawn

Osteochondral defects involve injury to bone and cartilage. As articular cartilage is worn down, bone in the joint begins to rub together, causing bone spurs. This is known as osteoarthritis, and is a common issue among the aging population. This problem presents an interesting opportunity for tissue engineering. Tissue engineering is an approach to treatment of tissue defects where synthetic, three dimensional (3-D) scaffolds are implanted in a defect to facilitate healing. The osteochondral scaffold consists of two regions in the form of a bilayer scaffold- one to mimic bone with osteoconductive properties, and one to mimic cartilage with biomimetic properties. One approach to improving the osteoconductivity of tissue engineering scaffolds is the addition of hydroxyapatite (HAp), the main mineral phase in bone. HAp with nanorod morphology is desirable because it is biomimetic for the calcium phosphate found in bone. Incorporating HAp nanorods in bone tissue engineering scaffolds to form a composite material may increase scaffold osteoconductivity. The cartilage scaffold is fabricated from chitosan and hyaluronic acid (HA). HA is a known component of cartilage and thus is biomimetic. The bilayer scaffolds were seeded with osteoblast-like MG-63 cells to investigate cell migration and were evaluated with Alamar Blue proliferation assay. The cells successfully migrated to the bone region of the scaffold, indicating that the bilayer scaffold provides a promising osteochondral scaffold.

Human umbilical cord mesenchymal stromal cells in a sandwich approach for osteochondral tissue engineering

PubMed Central

Wang, Limin; Zhao, Liang; Detamore, Michael S.

2013-01-01

Cell sources and tissue integration between cartilage and bone regions are critical to successful osteochondral regeneration. In this study, human umbilical cord mesenchymal stromal cells (hUCMSCs), derived from Wharton’s jelly, were introduced to the field of osteochondral tissue engineering and a new strategy for osteochondral integration was developed by sandwiching a layer of cells between chondrogenic and osteogenic constructs before suturing them together. Specifically, hUCMSCs were cultured in biodegradable poly-l-lactic acid scaffolds for 3 weeks in either chondrogenic or osteogenic medium to differentiate cells toward cartilage or bone lineages, respectively. A highly concentrated cell solution containing undifferentiated hUCMSCs was pasted onto the surface of the bone layer at week 3 and the two layers were then sutured together to form an osteochondral composite for another 3 week culture period. Chondrogenic and osteogenic differentiation was initiated during the first 3 weeks, as evidenced by the expression of type II collagen and runt-related transcription factor 2 genes, respectively, and continued with the increase of extracellular matrix during the last 3 weeks. Histological and immunohistochemical staining, such as for glycosaminoglycans, type I collagen and calcium, revealed better integration and transition of these matrices between two layers in the composite group containing sandwiched cells compared to other control composites. These results suggest that hUCMSCs may be a suitable cell source for osteochondral regeneration, and the strategy of sandwiching cells between two layers may facilitate scaffold and tissue integration. PMID:21953869

Current Concepts: Osteochondritis Dissecans of the Capitellum and the Role of Osteochondral Autograft Transplantation.

PubMed

Kirsch, Jacob M; Thomas, Jared; Bedi, Asheesh; Lawton, Jeffrey N

2016-12-01

Background: Osteochondritis dissecans (OCD) of the capitellum is a painful condition, which often affects young throwing athletes. Our current understanding regarding the etiology, risks factors, diagnosis, and efficacy of the available treatment options has expanded over recent years, however remains suboptimal. Recent data on patient-reported outcomes following osteochondral autograft transplantation (OAT) for the treatment of large osteochondral lesions of the capitellum have been promising but limited. This review seeks to critically analyze and summarize the available literature on the etiology, diagnosis, and reported outcomes associated with OCD of the capitellum and the use of OAT for its treatment. Methods: A comprehensive literature search was conducted. Unique and customized search strategies were formulated in PubMed, Embase, Scopus, Web of Science, and CENTRAL. Combinations of keywords and controlled vocabulary terms were utilized in order to cast a broad net. Relevant clinical, biomechanical, anatomic and imaging studies were reviewed along with recent review articles, and case series. Results: Forty-three articles from our initial literature search were found to be relevant for this review. The majority of these articles were either review articles, clinical studies, anatomic or imaging studies or biomechanical studies. Conclusions: Current evidence suggests that OAT may lead to better and more consistent outcomes than previously described methods for treating large OCD lesions of the capitellum.

Treatment of Osteochondral Defects in the Rabbit's Knee Joint by Implantation of Allogeneic Mesenchymal Stem Cells in Fibrin Clots

PubMed Central

Berninger, Markus T.; Wexel, Gabriele; Rummeny, Ernst J.; Imhoff, Andreas B.; Anton, Martina

2013-01-01

The treatment of osteochondral articular defects has been challenging physicians for many years. The better understanding of interactions of articular cartilage and subchondral bone in recent years led to increased attention to restoration of the entire osteochondral unit. In comparison to chondral lesions the regeneration of osteochondral defects is much more complex and a far greater surgical and therapeutic challenge. The damaged tissue does not only include the superficial cartilage layer but also the subchondral bone. For deep, osteochondral damage, as it occurs for example with osteochondrosis dissecans, the full thickness of the defect needs to be replaced to restore the joint surface 1. Eligible therapeutic procedures have to consider these two different tissues with their different intrinsic healing potential 2. In the last decades, several surgical treatment options have emerged and have already been clinically established 3-6. Autologous or allogeneic osteochondral transplants consist of articular cartilage and subchondral bone and allow the replacement of the entire osteochondral unit. The defects are filled with cylindrical osteochondral grafts that aim to provide a congruent hyaline cartilage covered surface 3,7,8. Disadvantages are the limited amount of available grafts, donor site morbidity (for autologous transplants) and the incongruence of the surface; thereby the application of this method is especially limited for large defects. New approaches in the field of tissue engineering opened up promising possibilities for regenerative osteochondral therapy. The implantation of autologous chondrocytes marked the first cell based biological approach for the treatment of full-thickness cartilage lesions and is now worldwide established with good clinical results even 10 to 20 years after implantation 9,10. However, to date, this technique is not suitable for the treatment of all types of lesions such as deep defects involving the subchondral bone 11. The sandwich-technique combines bone grafting with current approaches in Tissue Engineering 5,6. This combination seems to be able to overcome the limitations seen in osteochondral grafts alone. After autologous bone grafting to the subchondral defect area, a membrane seeded with autologous chondrocytes is sutured above and facilitates to match the topology of the graft with the injured site. Of course, the previous bone reconstruction needs additional surgical time and often even an additional surgery. Moreover, to date, long-term data is missing 12. Tissue Engineering without additional bone grafting aims to restore the complex structure and properties of native articular cartilage by chondrogenic and osteogenic potential of the transplanted cells. However, again, it is usually only the cartilage tissue that is more or less regenerated. Additional osteochondral damage needs a specific further treatment. In order to achieve a regeneration of the multilayered structure of osteochondral defects, three-dimensional tissue engineered products seeded with autologous/allogeneic cells might provide a good regeneration capacity 11. Beside autologous chondrocytes, mesenchymal stem cells (MSC) seem to be an attractive alternative for the development of a full-thickness cartilage tissue. In numerous preclinical in vitro and in vivo studies, mesenchymal stem cells have displayed excellent tissue regeneration potential 13,14. The important advantage of mesenchymal stem cells especially for the treatment of osteochondral defects is that they have the capacity to differentiate in osteocytes as well as chondrocytes. Therefore, they potentially allow a multilayered regeneration of the defect. In recent years, several scaffolds with osteochondral regenerative potential have therefore been developed and evaluated with promising preliminary results 1,15-18. Furthermore, fibrin glue as a cell carrier became one of the preferred techniques in experimental cartilage repair and has already successfully been used in several animal studies 19-21 and even first human trials 22. The following protocol will demonstrate an experimental technique for isolating mesenchymal stem cells from a rabbit's bone marrow, for subsequent proliferation in cell culture and for preparing a standardized in vitro-model for fibrin-cell-clots. Finally, a technique for the implantation of pre-established fibrin-cell-clots into artificial osteochondral defects of the rabbit's knee joint will be described. PMID:23728213

Reduction of Sample Size Requirements by Bilateral Versus Unilateral Research Designs in Animal Models for Cartilage Tissue Engineering

PubMed Central

Orth, Patrick; Zurakowski, David; Alini, Mauro; Cucchiarini, Magali

2013-01-01

Advanced tissue engineering approaches for articular cartilage repair in the knee joint rely on translational animal models. In these investigations, cartilage defects may be established either in one joint (unilateral design) or in both joints of the same animal (bilateral design). We hypothesized that a lower intraindividual variability following the bilateral strategy would reduce the number of required joints. Standardized osteochondral defects were created in the trochlear groove of 18 rabbits. In 12 animals, defects were produced unilaterally (unilateral design; n=12 defects), while defects were created bilaterally in 6 animals (bilateral design; n=12 defects). After 3 weeks, osteochondral repair was evaluated histologically applying an established grading system. Based on intra- and interindividual variabilities, required sample sizes for the detection of discrete differences in the histological score were determined for both study designs (α=0.05, β=0.20). Coefficients of variation (%CV) of the total histological score values were 1.9-fold increased following the unilateral design when compared with the bilateral approach (26 versus 14%CV). The resulting numbers of joints needed to treat were always higher for the unilateral design, resulting in an up to 3.9-fold increase in the required number of experimental animals. This effect was most pronounced for the detection of small-effect sizes and estimating large standard deviations. The data underline the possible benefit of bilateral study designs for the decrease of sample size requirements for certain investigations in articular cartilage research. These findings might also be transferred to other scoring systems, defect types, or translational animal models in the field of cartilage tissue engineering. PMID:23510128

Natural Origin Materials for Osteochondral Tissue Engineering.

PubMed

Bonani, Walter; Singhatanadgige, Weerasak; Pornanong, Aramwit; Motta, Antonella

2018-01-01

Materials selection is a critical aspect for the production of scaffolds for osteochondral tissue engineering. Synthetic materials are the result of man-made operations and have been investigated for a variety of tissue engineering applications. Instead, the products of physiological processes and the metabolic activity of living organisms are identified as natural materials. Over the recent decades, a number of natural materials, namely, biopolymers and bioceramics, have been proposed as the main constituent of osteochondral scaffolds, but also as cell carriers and signaling molecules. Overall, natural materials have been investigated both in the bone and in the cartilage compartment, sometimes alone, but often in combination with other biopolymers or synthetic materials. Biopolymers and bioceramics possess unique advantages over their synthetic counterparts due similarity with natural extracellular matrix, the presence of cell recognition sites and tunable chemistry. However, the characteristics of natural origin materials can vary considerably depending on the specific source and extraction process. A deeper understanding of the relationship between material variability and biological activity and the definition of standardized manufacturing procedures will be crucial for the future of natural materials in tissue engineering.

Enzyme-crosslinked gene-activated matrix for the induction of mesenchymal stem cells in osteochondral tissue regeneration.

PubMed

Lee, Yi-Hsuan; Wu, Hsi-Chin; Yeh, Chia-Wei; Kuan, Chen-Hsiang; Liao, Han-Tsung; Hsu, Horng-Chaung; Tsai, Jui-Che; Sun, Jui-Sheng; Wang, Tzu-Wei

2017-11-01

The development of osteochondral tissue engineering is an important issue for the treatment of traumatic injury or aging associated joint disease. However, the different compositions and mechanical properties of cartilage and subchondral bone show the complexity of this tissue interface, making it challenging for the design and fabrication of osteochondral graft substitute. In this study, a bilayer scaffold is developed to promote the regeneration of osteochondral tissue within a single integrated construct. It has the capacity to serve as a gene delivery platform to promote transfection of human mesenchymal stem cells (hMSCs) and the functional osteochondral tissues formation. For the subchondral bone layer, the bone matrix with organic (type I collagen, Col) and inorganic (hydroxyapatite, Hap) composite scaffold has been developed through mineralization of hydroxyapatite nanocrystals oriented growth on collagen fibrils. We also prepare multi-shell nanoparticles in different layers with a calcium phosphate core and DNA/calcium phosphate shells conjugated with polyethyleneimine to act as non-viral vectors for delivery of plasmid DNA encoding BMP2 and TGF-β3, respectively. Microbial transglutaminase is used as a cross-linking agent to crosslink the bilayer scaffold. The ability of this scaffold to act as a gene-activated matrix is demonstrated with successful transfection efficiency. The results show that the sustained release of plasmids from gene-activated matrix can promote prolonged transgene expression and stimulate hMSCs differentiation into osteogenic and chondrogenic lineages by spatial and temporal control within the bilayer composite scaffold. This improved delivery method may enhance the functionalized composite graft to accelerate healing process for osteochondral tissue regeneration. In this study, a gene-activated matrix (GAM) to promote the growth of both cartilage and subchondral bone within a single integrated construct is developed. It has the capacity to promote transfection of human mesenchymal stem cells (hMSCs) and the functional osteochondral tissues formation. The results show that the sustained release of plasmids including TGF-beta and BMP-2 from GAM could promote prolonged transgene expression and stimulate hMSCs differentiation into the osteogenic and chondrogenic lineages by spatial control manner. This improved delivery method should enhance the functionalized composite graft to accelerate healing process in vitro and in vivo for osteochondral tissue regeneration. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Composite scaffolds for osteochondral repair obtained by combination of additive manufacturing, leaching processes and hMSC-CM functionalization.

PubMed

Díaz Lantada, Andrés; Alarcón Iniesta, Hernán; García-Ruíz, Josefa Predestinación

2016-02-01

Articular repair is a relevant and challenging area for the emerging fields of tissue engineering and biofabrication. The need of significant gradients of properties, for the promotion of osteochondral repair, has led to the development of several families of composite biomaterials and scaffolds, using different effective approaches, although a perfect solution has not yet been found. In this study we present the design, modeling, rapid manufacturing and in vitro testing of a composite scaffold aimed at osteochondral repair. The presented composite scaffold stands out for having a functional gradient of density and stiffness in the bony phase, obtained in titanium by means of computer-aided design combined with additive manufacture using selective laser sintering. The chondral phase is obtained by sugar leaching, using a PDMS matrix and sugar as porogen, and is joined to the bony phase during the polymerization of PDMS, therefore avoiding the use of supporting adhesives or additional intermediate layers. The mechanical performance of the construct is biomimetic and the stiffness values of the bony and chondral phases can be tuned to the desired applications, by means of controlled modifications of different parameters. A human mesenchymal stem cell (h-MSC) conditioned medium (CM) is used for improving scaffold response. Cell culture results provide relevant information regarding the viability of the composite scaffolds used. Copyright © 2015 Elsevier B.V. All rights reserved.

Promoting Cartilage Stem Cell Activity to Improve Recovery from Joint Fracture

DTIC Science & Technology

2012-09-01

were obtained after slaughter from a local abattoir (Bud’s Custom Meats , Riverside, IA). Osteochondral explants were prepared by manually sawing an...from the superficial 1/3 or lower 2/3 of the matrix were plated in 150-mm culture dishes and incubated for 10 days. A custom-fabricated device was...Richardson’s stain. The dishes were scanned on a flat bed scanner (300 dpi) and the number of colonies and colony diameters were measured using

Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds

NASA Astrophysics Data System (ADS)

Castro, Nathan J.; O'Brien, Joseph; Zhang, Lijie Grace

2015-08-01

The osteochondral interface of an arthritic joint is notoriously difficult to regenerate due to its extremely poor regenerative capacity and complex stratified architecture. Native osteochondral tissue extracellular matrix is composed of numerous nanoscale organic and inorganic constituents. Although various tissue engineering strategies exist in addressing osteochondral defects, limitations persist with regards to tissue scaffolding which exhibit biomimetic cues at the nano to micro scale. In an effort to address this, the current work focused on 3D printing biomimetic nanocomposite scaffolds for improved osteochondral tissue regeneration. For this purpose, two biologically-inspired nanomaterials have been synthesized consisting of (1) osteoconductive nanocrystalline hydroxyapatite (nHA) (primary inorganic component of bone) and (2) core-shell poly(lactic-co-glycolic) acid (PLGA) nanospheres encapsulated with chondrogenic transforming growth-factor β1 (TGF-β1) for sustained delivery. Then, a novel table-top stereolithography 3D printer and the nano-ink (i.e., nHA + nanosphere + hydrogel) were employed to fabricate a porous and highly interconnected osteochondral scaffold with hierarchical nano-to-micro structure and spatiotemporal bioactive factor gradients. Our results showed that human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation were greatly improved in the biomimetic graded 3D printed osteochondral construct in vitro. The current work served to illustrate the efficacy of the nano-ink and current 3D printing technology for efficient fabrication of a novel nanocomposite hydrogel scaffold. In addition, tissue-specific growth factors illustrated a synergistic effect leading to increased cell adhesion and directed stem cell differentiation.

A comparative study on collagen type I and hyaluronic acid dependent cell behavior for osteochondral tissue bioprinting.

PubMed

Park, Ju Young; Choi, Jong-Cheol; Shim, Jin-Hyung; Lee, Jung-Seob; Park, Hyoungjun; Kim, Sung Won; Doh, Junsang; Cho, Dong-Woo

2014-09-01

Bioprinting is a promising technique for engineering composite tissues, such as osteochondral tissues. In this study, as a first step toward bioprinting-based osteochondral tissue regeneration, we systematically examined the behavior of chondrocytes and osteoblasts to hyaluronic acid (HA) and type I collagen (Col-1) hydrogels. First, we demonstrated that cells on hydrogels that were comprised of major native tissue extracellular matrix (ECM) components (i.e. chondrocytes on HA hydrogels and osteoblasts on Col-1 hydrogels) exhibited better proliferation and cell function than cells on non-native ECM hydrogels (i.e., chondrocytes on Col-1 hydrogels and osteoblasts on HA hydrogels). In addition, cells located near their native ECM hydrogels migrated towards them. Finally, we bioprinted three-dimensional (3D) osteochondral tissue-mimetic structures composed of two compartments, osteoblast-encapsulated Col-1 hydrogels and chondrocyte-encapsulated HA hydrogels, and found viability and functions of each cell type were well maintained within the 3D structures up to 14 days in vitro. These results suggest that with proper choice of hydrogel materials, bioprinting-based approaches can be successfully applied for osteochondral tissue regeneration.

A human osteoarthritis osteochondral organ culture model for cartilage tissue engineering.

PubMed

Yeung, P; Zhang, W; Wang, X N; Yan, C H; Chan, B P

2018-04-01

In vitro human osteoarthritis (OA)-mimicking models enabling pathophysiological studies and evaluation of emerging therapies such as cartilage tissue engineering are of great importance. We describe the development and characterization of a human OA osteochondral organ culture. We also apply this model for evaluation of the phenotype maintenance of a human MSC derived engineered cartilage, as an example of emerging therapeutics, under long term exposure to the OA-mimicking environment. We also test the sensitivity of the model to a series of external factors and a potential disease-modifying agent, in terms of chondrogenic phenotype maintenance of the engineered cartilage, under OA-mimicking environment. Excised joint tissues from total knee replacement surgeries were carved into numerous miniaturized and standardized osteochondral plugs for subsequent OA organ culture. The organ cultures were characterized in detail before being co-cultured with a tissue engineered cartilage. The chondrogenic phenotype of the tissue engineered cartilage co-cultured in long term up to 8 weeks under this OA-mimicking microenvironment was evaluated. Using the same co-culture model, we also screened for a number of biomimetic environmental factors, including oxygen tension, the presence of serum and the application of compression loading. Finally, we studied the effect of a matrix metalloprotease inhibitor, as an example of potential disease-modifying agents, on the co-cultured engineered cartilage. We demonstrate that cells in the OA organ culture were viable while both the typical chondrogenic phenotype and the characteristic OA phenotype were maintained for long period of time. We then demonstrate that upon co-culture with the OA-mimicking organ culture, the engineered cartilage initially exhibited a more fibrocartilage phenotype but progressively reverted back to the chondrogenic phenotype upon long term co-culture up to 8 weeks. The engineered cartilage was also found to be sensitive to all biomimetic environmental factors screened (oxygen tension, serum and compression). Moreover, under the effect of a MMP inhibitor, the chondrogenic phenotype of engineered cartilage was better maintained. We demonstrated the development of a human OA osteochondral organ culture and tested the feasibility and potential of using this model as an in vitro evaluation tool for emerging cartilage therapies. Copyright © 2018 Elsevier Ltd. All rights reserved.

An Interdisciplinary Approach for Understanding Information Utilization in Engineering and Product Design

ERIC Educational Resources Information Center

Bi, Youyi

2017-01-01

Human-centered design requires thorough understanding of people (e.g. customers, designers, engineers) in order to better satisfy the needs and expectations of all stakeholders in the design process. Designers are able to create better products by incorporating customers' subjective evaluations on products. Engineers can also build better tools…

Bioprinting of a mechanically enhanced three-dimensional dual cell-laden construct for osteochondral tissue engineering using a multi-head tissue/organ building system

NASA Astrophysics Data System (ADS)

Shim, Jin-Hyung; Lee, Jung-Seob; Kim, Jong Young; Cho, Dong-Woo

2012-08-01

The aim of this study was to build a mechanically enhanced three-dimensional (3D) bioprinted construct containing two different cell types for osteochondral tissue regeneration. Recently, the production of 3D cell-laden structures using various scaffold-free cell printing technologies has opened up new possibilities. However, ideal 3D complex tissues or organs have not yet been printed because gel-state hydrogels have been used as the principal material and are unable to maintain the desired 3D structure due to their poor mechanical strength. In this study, thermoplastic biomaterial polycaprolactone (PCL), which shows relatively high mechanical properties as compared with hydrogel, was used as a framework for enhancing the mechanical stability of the bioprinted construct. Two different alginate solutions were then infused into the previously prepared framework consisting of PCL to create the 3D construct for osteochondral printing. For this work, a multi-head tissue/organ building system (MtoBS), which was particularly designed to dispense thermoplastic biomaterial and hydrogel having completely different rheology properties, was newly developed and used to bioprint osteochondral tissue. It was confirmed that the line width, position and volume control of PCL and alginate solutions were adjustable in the MtoBS. Most importantly, dual cell-laden 3D constructs consisting of osteoblasts and chondrocytes were successfully fabricated. Further, the separately dispensed osteoblasts and chondrocytes not only retained their initial position and viability, but also proliferated up to 7 days after being dispensed.

Controlled Release Strategies for Bone, Cartilage, and Osteochondral Engineering—Part II: Challenges on the Evolution from Single to Multiple Bioactive Factor Delivery

PubMed Central

Santo, Vítor E.; Mano, João F.; Reis, Rui L.

2013-01-01

The development of controlled release systems for the regeneration of bone, cartilage, and osteochondral interface is one of the hot topics in the field of tissue engineering and regenerative medicine. However, the majority of the developed systems consider only the release of a single growth factor, which is a limiting step for the success of the therapy. More recent studies have been focused on the design and tailoring of appropriate combinations of bioactive factors to match the desired goals regarding tissue regeneration. In fact, considering the complexity of extracellular matrix and the diversity of growth factors and cytokines involved in each biological response, it is expected that an appropriate combination of bioactive factors could lead to more successful outcomes in tissue regeneration. In this review, the evolution on the development of dual and multiple bioactive factor release systems for bone, cartilage, and osteochondral interface is overviewed, specifically the relevance of parameters such as dosage and spatiotemporal distribution of bioactive factors. A comprehensive collection of studies focused on the delivery of bioactive factors is also presented while highlighting the increasing impact of platelet-rich plasma as an autologous source of multiple growth factors. PMID:23249320

Repair Mechanism of Osteochondral Defect Promoted by Bioengineered Chondrocyte Sheet

PubMed Central

Kamei, Naosuke; Adachi, Nobuo; Hamanishi, Michio; Kamei, Goki; Mahmoud, Elhussein Elbadry; Nakano, Tomohiro; Iwata, Takanori; Yamato, Masayuki; Okano, Teruo; Ochi, Mitsuo

2015-01-01

Cell sheet engineering has developed as a remarkable method for cell transplantation. In the field of cartilage regeneration, several studies previously reported that cartilage defects could be regenerated by transplantation of a chondrocyte sheet using cell sheet engineering. However, it remains unclear how such a thin cell sheet could repair a deep cartilage defect. We, therefore, focused on the mechanism of cartilage repair using cell sheet engineering in this study. Chondrocyte sheets and synovial cell sheets were fabricated using cell sheet engineering, and these allogenic cell sheets were transplanted to cover an osteochondral defect in a rat model. Macroscopic and histological evaluation was performed at 4 and 12 weeks after transplantation. Analysis of the gene expression of each cell sheet and of the regenerated tissue at 1 week after transplantation was performed. In addition, green fluorescent protein (GFP) transgenic rats were used as donors (transplanted chondrocyte sheets) or recipients (osteochondral defect models) to identify the cell origin of regenerated cartilage. Cartilage repair was significantly better in the group implanted with a chondrocyte sheet than in that with a synovial cell sheet. The results of gene expression analysis suggest that the possible factor contributing to cartilage repair might be TGFβ1. Cell tracking experiments using GFP transgenic rats showed that the regenerated cartilage was largely composed of cells derived from the transplanted chondrocyte sheets. PMID:25396711

Gradient nano-engineered in situ forming composite hydrogel for osteochondral regeneration.

PubMed

Radhakrishnan, Janani; Manigandan, Amrutha; Chinnaswamy, Prabu; Subramanian, Anuradha; Sethuraman, Swaminathan

2018-04-01

Fabrication of anisotropic osteochondral-mimetic scaffold with mineralized subchondral zone and gradient interface remains challenging. We have developed an injectable semi-interpenetrating network hydrogel construct with chondroitin sulfate nanoparticles (ChS-NPs) and nanohydroxyapatite (nHA) (∼30-90 nm) in chondral and subchondral hydrogel zones respectively. Mineralized subchondral hydrogel exhibited significantly higher osteoblast proliferation and alkaline phosphatase activity (p < 0.05). Osteochondral hydrogel exhibited interconnected porous structure and spatial variation with gradient interface of nHA and ChS-NPs. Microcomputed tomography (μCT) demonstrated nHA gradation while rheology showed predominant elastic modulus (∼930 Pa) at the interface. Co-culture of osteoblasts and chondrocytes in gradient hydrogels showed layer-specific retention of cells and cell-cell interaction at the interface. In vivo osteochondral regeneration by biphasic (nHA or ChS) and gradient (nHA + ChS) hydrogels was compared with control using rabbit osteochondral defect after 3 and 8 weeks. Complete closure of defect was observed in gradient (8 weeks) while defect remained in other groups. Histology demonstrated collagen and glycosaminoglycan deposition in neo-matrix and presence of hyaline cartilage-characteristic matrix, chondrocytes and osteoblasts. μCT showed mineralized neo-tissue formation, which was confined within the defect with higher bone mineral density in gradient (chondral: 0.42 ± 0.07 g/cc, osteal: 0.64 ± 0.08 g/cc) group. Further, biomechanical push-out studies showed significantly higher load for gradient group (378 ± 56 N) compared to others. Thus, the developed nano-engineered gradient hydrogel enhanced hyaline cartilage regeneration with subchondral bone formation and lateral host-tissue integration. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influence of End Customer Exposure on Product Design within an Epistemic Game Environment

ERIC Educational Resources Information Center

Markovetz, Matthew R.; Clark, Renee M.; Swiecki, Zachari; Irgens, Golnaz Arastoopour; Chesler, Naomi C.; Shaffer, David W.; Bodnar, Cheryl A.

2017-01-01

Engineering product design requires both technical aptitude and an understanding of the nontechnical requirements in the marketplace, economic or otherwise. Engineering education has long focused on the technical side of product design, but there is increasing demand for market-aware engineers in industry. Market-awareness and customer-focus are…

High-throughput bone and cartilage micropellet manufacture, followed by assembly of micropellets into biphasic osteochondral tissue.

PubMed

Babur, Betul Kul; Futrega, Kathryn; Lott, William B; Klein, Travis Jacob; Cooper-White, Justin; Doran, Michael Robert

2015-09-01

Engineered biphasic osteochondral tissues may have utility in cartilage defect repair. As bone-marrow-derived mesenchymal stem/stromal cells (MSC) have the capacity to make both bone-like and cartilage-like tissues, they are an ideal cell population for use in the manufacture of osteochondral tissues. Effective differentiation of MSC to bone-like and cartilage-like tissues requires two unique medium formulations and this presents a challenge both in achieving initial MSC differentiation and in maintaining tissue stability when the unified osteochondral tissue is subsequently cultured in a single medium formulation. In this proof-of-principle study, we used an in-house fabricated microwell platform to manufacture thousands of micropellets formed from 166 MSC each. We then characterized the development of bone-like and cartilage-like tissue formation in the micropellets maintained for 8-14 days in sequential combinations of osteogenic or chondrogenic induction medium. When bone-like or cartilage-like micropellets were induced for only 8 days, they displayed significant phenotypic changes when the osteogenic or chondrogenic induction medium, respectively, was swapped. Based on these data, we developed an extended 14-day protocol for the pre-culture of bone-like and cartilage-like micropellets in their respective induction medium. Unified osteochondral tissues were formed by layering 12,000 osteogenic micropellets and 12,000 chondrogenic micropellets into a biphasic structure and then further culture in chondrogenic induction medium. The assembled tissue was cultured for a further 8 days and characterized via histology. The micropellets had amalgamated into a continuous structure with distinctive bone-like and cartilage-like regions. This proof-of-concept study demonstrates the feasibility of micropellet assembly for the formation of osteochondral-like tissues for possible use in osteochondral defect repair.

Tissue engineering-based cartilage repair with mesenchymal stem cells in a porcine model.

PubMed

Chang, Chih-Hung; Kuo, Tzong-Fu; Lin, Feng-Huei; Wang, Jyh-Horng; Hsu, Yuan-Ming; Huang, Huei-Ting; Loo, Shiao-Tung; Fang, Hsu-Wei; Liu, Hwa-Chang; Wang, Wen-Chih

2011-12-01

This in vivo pilot study explored the use of mesenchymal stem cell (MSC) containing tissue engineering constructs in repair of osteochondral defects. Osteochondral defects were created in the medial condyles of both knees of 16 miniature pigs. One joint received a cell/collagen tissue engineering construct with or without pretreatment with transforming growth factor β (TGF-β) and the other joint from the same pig received no treatment or the gel scaffold only. Six months after surgery, in knees with no treatment, all defects showed contracted craters; in those treated with the gel scaffold alone, six showed a smooth gross surface, one a hypertrophic surface, and one a contracted crater; in those with undifferentiated MSCs, five defects had smooth, fully repaired surfaces or partially repaired surfaces, and one defect poor repair; in those with TGF-β-induced differentiated MSCs, seven defects had smooth, fully repaired surfaces or partially repaired surfaces, and three defects showed poor repair. In Pineda score grading, the group with undifferentiated MSC, but not the group with TGF-β-induced differentiated MSCs, had significantly lower subchondral, cell morphology, and total scores than the groups with no or gel-only treatment. The compressive stiffness was larger in cartilage without surgical treatment than the treated area within each group. In conclusion, this preliminary pilot study suggests that using undifferentiated MSCs might be a better approach than using TGF-β-induced differentiated MSCs for in vivo tissue engineered treatment of osteochondral defects. Copyright © 2011 Orthopaedic Research Society.

Mechanical loading regulates human MSC differentiation in a multi-layer hydrogel for osteochondral tissue engineering.

PubMed

Steinmetz, Neven J; Aisenbrey, Elizabeth A; Westbrook, Kristofer K; Qi, H Jerry; Bryant, Stephanie J

2015-07-01

A bioinspired multi-layer hydrogel was developed for the encapsulation of human mesenchymal stem cells (hMSCs) as a platform for osteochondral tissue engineering. The spatial presentation of biochemical cues, via incorporation of extracellular matrix analogs, and mechanical cues, via both hydrogel crosslink density and externally applied mechanical loads, were characterized in each layer. A simple sequential photopolymerization method was employed to form stable poly(ethylene glycol)-based hydrogels with a soft cartilage-like layer of chondroitin sulfate and low RGD concentrations, a stiff bone-like layer with high RGD concentrations, and an intermediate interfacial layer. Under a compressive load, the variation in hydrogel stiffness within each layer produced high strains in the soft cartilage-like layer, low strains in the stiff bone-like layer, and moderate strains in the interfacial layer. When hMSC-laden hydrogels were cultured statically in osteochondral differentiation media, the local biochemical and matrix stiffness cues were not sufficient to spatially guide hMSC differentiation after 21 days. However dynamic mechanical stimulation led to differentially high expression of collagens with collagen II in the cartilage-like layer, collagen X in the interfacial layer and collagen I in the bone-like layer and mineral deposits localized to the bone layer. Overall, these findings point to external mechanical stimulation as a potent regulator of hMSC differentiation toward osteochondral cellular phenotypes. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A novel, visible light-induced, rapidly cross-linkable gelatin scaffold for osteochondral tissue engineering

PubMed Central

Mazaki, Tetsuro; Shiozaki, Yasuyuki; Yamane, Kentaro; Yoshida, Aki; Nakamura, Mariko; Yoshida, Yasuhiro; Zhou, Di; Kitajima, Takashi; Tanaka, Masato; Ito, Yoshihiro; Ozaki, Toshifumi; Matsukawa, Akihiro

2014-01-01

Osteochondral injuries remain difficult to repair. We developed a novel photo-cross-linkable furfurylamine-conjugated gelatin (gelatin-FA). Gelatin-FA was rapidly cross-linked by visible light with Rose Bengal, a light sensitizer, and was kept gelled for 3 weeks submerged in saline at 37°C. When bone marrow-derived stromal cells (BMSCs) were suspended in gelatin-FA with 0.05% Rose Bengal, approximately 87% of the cells were viable in the hydrogel at 24 h after photo-cross-linking, and the chondrogenic differentiation of BMSCs was maintained for up to 3 weeks. BMP4 fusion protein with a collagen binding domain (CBD) was retained in the hydrogels at higher levels than unmodified BMP4. Gelatin-FA was subsequently employed as a scaffold for BMSCs and CBD-BMP4 in a rabbit osteochondral defect model. In both cases, the defect was repaired with articular cartilage-like tissue and regenerated subchondral bone. This novel, photo-cross-linkable gelatin appears to be a promising scaffold for the treatment of osteochondral injury. PMID:24662725

Review: Polymeric-Based 3D Printing for Tissue Engineering.

PubMed

Wu, Geng-Hsi; Hsu, Shan-Hui

Three-dimensional (3D) printing, also referred to as additive manufacturing, is a technology that allows for customized fabrication through computer-aided design. 3D printing has many advantages in the fabrication of tissue engineering scaffolds, including fast fabrication, high precision, and customized production. Suitable scaffolds can be designed and custom-made based on medical images such as those obtained from computed tomography. Many 3D printing methods have been employed for tissue engineering. There are advantages and limitations for each method. Future areas of interest and progress are the development of new 3D printing platforms, scaffold design software, and materials for tissue engineering applications.

Stem cell- and scaffold-based tissue engineering approaches to osteochondral regenerative medicine

PubMed Central

Sundelacruz, Sarah; Kaplan, David L.

2009-01-01

In osteochondral tissue engineering, cell recruitment, proliferation, differentiation, and patterning are critical for forming biologically and structurally viable constructs for repair of damaged or diseased tissue. However, since constructs prepared ex vivo lack the multitude of cues present in the in vivo microenvironment, cells often need to be supplied with external biological and physical stimuli to coax them towards targeted tissue functions. To determine which stimuli to present to cells, bioengineering strategies can benefit significantly from endogenous examples of skeletogenesis. As an example of developmental skeletogenesis, the developing limb bud serves as an excellent model system in which to study how an osteochondral structures form from undifferentiated precursor cells. Alongside skeletal formation during embryogenesis, bone also possesses innate regenerative capacity, displaying remarkable ability to heal after damage. Bone fracture healing shares many features with bone development, driving the hypothesis that the regenerative process generally recapitulates development. Similarities and differences between the two modes of bone formation may offer insight into the special requirements for healing damaged or diseased bone. Thus, endogenous fracture healing, as an example of regenerative skeletogenesis, may also inform bioengineering strategies. In this review, we summarize the key cellular events involving stem and progenitor cells in developmental and regenerative skeletogenesis, and discuss in parallel the corresponding cell- and scaffold-based strategies that tissue engineers employ to recapitulate these events in vitro. PMID:19508851

Integrating three-dimensional printing and nanotechnology for musculoskeletal regeneration

NASA Astrophysics Data System (ADS)

Nowicki, Margaret; Castro, Nathan J.; Rao, Raj; Plesniak, Michael; Zhang, Lijie Grace

2017-09-01

The field of tissue engineering is advancing steadily, partly due to advancements in rapid prototyping technology. Even with increasing focus, successful complex tissue regeneration of vascularized bone, cartilage and the osteochondral interface remains largely illusive. This review examines current three-dimensional printing techniques and their application towards bone, cartilage and osteochondral regeneration. The importance of, and benefit to, nanomaterial integration is also highlighted with recent published examples. Early-stage successes and challenges of recent studies are discussed, with an outlook to future research in the related areas.

Integrating three-dimensional printing and nanotechnology for musculoskeletal regeneration

PubMed Central

Nowicki, Margaret; Castro, Nathan J; Rao, Raj; Plesniak, Michael; Zhang, Lijie Grace

2017-01-01

The field of tissue engineering is advancing steadily, partly due to advancements in rapid prototyping technology. Even with increasing focus, successful complex tissue regeneration of vascularized bone, cartilage and the osteochondral interface remains largely illusive. This review examines current three-dimensional printing techniques and their application towards bone, cartilage and osteochondral regeneration. The importance of, and benefit to, nanomaterial integration is also highlighted with recent published examples. Early-stage successes and challenges of recent studies are discussed, with an outlook to future research in the related areas. PMID:28762957

Biphasic Scaffolds from Marine Collagens for Regeneration of Osteochondral Defects.

PubMed

Bernhardt, Anne; Paul, Birgit; Gelinsky, Michael

2018-03-13

Collagens of marine origin are applied increasingly as alternatives to mammalian collagens in tissue engineering. The aim of the present study was to develop a biphasic scaffold from exclusively marine collagens supporting both osteogenic and chondrogenic differentiation and to find a suitable setup for in vitro chondrogenic and osteogenic differentiation of human mesenchymal stroma cells (hMSC). Biphasic scaffolds from biomimetically mineralized salmon collagen and fibrillized jellyfish collagen were fabricated by joint freeze-drying and crosslinking. Different experiments were performed to analyze the influence of cell density and TGF-β on osteogenic differentiation of the cells in the scaffolds. Gene expression analysis and analysis of cartilage extracellular matrix components were performed and activity of alkaline phosphatase was determined. Furthermore, histological sections of differentiated cells in the biphasic scaffolds were analyzed. Stable biphasic scaffolds from two different marine collagens were prepared. An in vitro setup for osteochondral differentiation was developed involving (1) different seeding densities in the phases; (2) additional application of alginate hydrogel in the chondral part; (3) pre-differentiation and sequential seeding of the scaffolds and (4) osteochondral medium. Spatially separated osteogenic and chondrogenic differentiation of hMSC was achieved in this setup, while osteochondral medium in combination with the biphasic scaffolds alone was not sufficient to reach this ambition. Biphasic, but monolithic scaffolds from exclusively marine collagens are suitable for the development of osteochondral constructs.

Design of a high-speed digital processing element for parallel simulation

NASA Technical Reports Server (NTRS)

Milner, E. J.; Cwynar, D. S.

1983-01-01

A prototype of a custom designed computer to be used as a processing element in a multiprocessor based jet engine simulator is described. The purpose of the custom design was to give the computer the speed and versatility required to simulate a jet engine in real time. Real time simulations are needed for closed loop testing of digital electronic engine controls. The prototype computer has a microcycle time of 133 nanoseconds. This speed was achieved by: prefetching the next instruction while the current one is executing, transporting data using high speed data busses, and using state of the art components such as a very large scale integration (VLSI) multiplier. Included are discussions of processing element requirements, design philosophy, the architecture of the custom designed processing element, the comprehensive instruction set, the diagnostic support software, and the development status of the custom design.

Engineering performance metrics

NASA Astrophysics Data System (ADS)

Delozier, R.; Snyder, N.

1993-03-01

Implementation of a Total Quality Management (TQM) approach to engineering work required the development of a system of metrics which would serve as a meaningful management tool for evaluating effectiveness in accomplishing project objectives and in achieving improved customer satisfaction. A team effort was chartered with the goal of developing a system of engineering performance metrics which would measure customer satisfaction, quality, cost effectiveness, and timeliness. The approach to developing this system involved normal systems design phases including, conceptual design, detailed design, implementation, and integration. The lessons teamed from this effort will be explored in this paper. These lessons learned may provide a starting point for other large engineering organizations seeking to institute a performance measurement system accomplishing project objectives and in achieving improved customer satisfaction. To facilitate this effort, a team was chartered to assist in the development of the metrics system. This team, consisting of customers and Engineering staff members, was utilized to ensure that the needs and views of the customers were considered in the development of performance measurements. The development of a system of metrics is no different than the development of any type of system. It includes the steps of defining performance measurement requirements, measurement process conceptual design, performance measurement and reporting system detailed design, and system implementation and integration.

Customized Fabrication of Osteochondral Tissue for Articular Joint Surface Repair

DTIC Science & Technology

2015-09-01

Kilroy EJ, Tuan RS. (2015) Projection Stereolithographic Fabrication of Human Adipose Stem Cell-incorporated Biodegradable Scaffolds for Cartilage...necessary to include the publications already specified above in this section. Nothing to Report (1) Live Cell-scaffold Printing using Biodegradable ...and PCL scaffolds using PSL (Figure 1,2). Solid PDLLA-PEG scaffold (30%) possesses a compressive modulus up to 800kPa and is biodegradable in

Advancing osteochondral tissue engineering: bone morphogenetic protein, transforming growth factor, and fibroblast growth factor signaling drive ordered differentiation of periosteal cells resulting in stable cartilage and bone formation in vivo.

PubMed

Mendes, L F; Katagiri, H; Tam, W L; Chai, Y C; Geris, L; Roberts, S J; Luyten, F P

2018-02-21

Chondrogenic mesenchymal stem cells (MSCs) have not yet been used to address the clinical demands of large osteochondral joint surface defects. In this study, self-assembling tissue intermediates (TIs) derived from human periosteum-derived stem/progenitor cells (hPDCs) were generated and validated for stable cartilage formation in vivo using two different animal models. hPDCs were aggregated and cultured in the presence of a novel growth factor (GF) cocktail comprising of transforming growth factor (TGF)-β1, bone morphogenetic protein (BMP)2, growth differentiation factor (GDF)5, BMP6, and fibroblast growth factor (FGF)2. Quantitative polymerase chain reaction (PCR) and immunohistochemistry were used to study in vitro differentiation. Aggregates were then implanted ectopically in nude mice and orthotopically in critical-size osteochondral defects in nude rats and evaluated by microcomputed tomography (µCT) and immunohistochemistry. Gene expression analysis after 28 days of in vitro culture revealed the expression of early and late chondrogenic markers and a significant upregulation of NOGGIN as compared to human articular chondrocytes (hACs). Histological examination revealed a bilayered structure comprising of chondrocytes at different stages of maturity. Ectopically, TIs generated both bone and mineralized cartilage at 8 weeks after implantation. Osteochondral defects treated with TIs displayed glycosaminoglycan (GAG) production, type-II collagen, and lubricin expression. Immunostaining for human nuclei protein suggested that hPDCs contributed to both subchondral bone and articular cartilage repair. Our data indicate that in vitro derived osteochondral-like tissues can be generated from hPDCs, which are capable of producing bone and cartilage ectopically and behave orthotopically as osteochondral units.

Engineering Orthopedic Tissue Interfaces

PubMed Central

Yang, Peter J.

2009-01-01

While a wide variety of approaches to engineering orthopedic tissues have been proposed, less attention has been paid to the interfaces, the specialized areas that connect two tissues of different biochemical and mechanical properties. The interface tissue plays an important role in transitioning mechanical load between disparate tissues. Thus, the relatively new field of interfacial tissue engineering presents new challenges—to not only consider the regeneration of individual orthopedic tissues, but also to design the biochemical and cellular composition of the linking tissue. Approaches to interfacial tissue engineering may be distinguished based on if the goal is to recreate the interface itself, or generate an entire integrated tissue unit (such as an osteochondral plug). As background for future efforts in engineering orthopedic interfaces, a brief review of the biology and mechanics of each interface (cartilage–bone, ligament–bone, meniscus–bone, and muscle–tendon) is presented, followed by an overview of the state-of-the-art in engineering each tissue, including advances and challenges specific to regenerating the interfaces. PMID:19231983

Promising Biomolecules.

PubMed

Oliveira, Isabel; Carvalho, Ana L; Radhouani, Hajer; Gonçalves, Cristiana; Oliveira, J Miguel; Reis, Rui L

2018-01-01

The osteochondral defect (OD) comprises the articular cartilage and its subchondral bone. The treatment of these lesions remains as one of the most problematic clinical issues, since these defects include different tissues, requiring distinct healing approaches. Among the growing applications of regenerative medicine, clinical articular cartilage repair has been used for two decades, and it is an effective example of translational medicine; one of the most used cell-based repair strategies includes implantation of autologous cells in degradable scaffolds such as alginate, agarose, collagen, chitosan, chondroitin sulfate, cellulose, silk fibroin, hyaluronic acid, and gelatin, among others. Concerning the repair of osteochondral defects, tissue engineering and regenerative medicine started to design single- or bi-phased scaffold constructs, often containing hydroxyapatite-collagen composites, usually used as a bone substitute. Biomolecules such as natural and synthetic have been explored to recreate the cartilage-bone interface through multilayered biomimetic scaffolds. In this chapter, a succinct description about the most relevant natural and synthetic biomolecules used on cartilage and bone repair, describing the procedures to obtain these biomolecules, their chemical structure, common modifications to improve its characteristics, and also their application in the biomedical fields, is given.

Prototyping and implementing flight qualifiable semicustom CMOS P-well bulk integrated circuits in the JPL environment

NASA Technical Reports Server (NTRS)

Olson, E. M.

1986-01-01

Presently, there are many difficulties associated with implementing application specific custom or semi-custom (standard cell based) integrated circuits (ICs) into JPL flight projects. One of the primary difficulties is developing prototype semi-custom integrated circuits for use and evaluation in engineering prototype flight hardware. The prototype semi-custom ICs must be extremely cost-effective and yet still representative of flight qualifiable versions of the design. A second difficulty is encountered in the transport of the design from engineering prototype quality to flight quality. Normally, flight quality integrated circuits have stringent quality standards, must be radiation resistant and should consume minimal power. It is often not necessary or cost effective, however, to impose such stringent quality standards on engineering models developed for systems analysis in controlled lab environments. This article presents work originally initiated for ground based applications that also addresses these two problems. Furthermore, this article suggests a method that has been shown successful in prototyping flight quality semi-custom ICs through the Metal Oxide Semiconductor Implementation Service (MOSIS) program run by the University of Southern California's Information Sciences Institute. The method has been used successfully to design and fabricate through the MOSIS three different semi-custom prototype CMOS p-well chips. The three designs make use of the work presented and were designed consistent with design techniques and structures that are flight qualifiable, allowing one hour transfer of the design from engineering model status to flight qualifiable foundry-ready status through methods outlined in this article.

Synthetic Materials for Osteochondral Tissue Engineering.

PubMed

Iulian, Antoniac; Dan, Laptoiu; Camelia, Tecu; Claudia, Milea; Sebastian, Gradinaru

2018-01-01

The objective of an articular cartilage repair treatment is to repair the affected surface of an articular joint's hyaline cartilage. Currently, both biological and tissue engineering research is concerned with discovering the clues needed to stimulate cells to regenerate tissues and organs totally or partially. The latest findings on nanotechnology advances along with the processability of synthetic biomaterials have succeeded in creating a new range of materials to develop into the desired biological responses to the cellular level. 3D printing has a great ability to establish functional tissues or organs to cure or replace abnormal and necrotic tissue, providing a promising solution for serious tissue/organ failure. The 4D print process has the potential to continually revolutionize the current tissue and organ manufacturing platforms. A new active research area is the development of intelligent materials with high biocompatibility to suit 4D printing technology. As various researchers and tissue engineers have demonstrated, the role of growth factors in tissue engineering for repairing osteochondral and cartilage defects is a very important one. Following animal testing, cell-assisted and growth-factor scaffolds produced much better results, while growth-free scaffolds showed a much lower rate of healing.

Biofabrication of tissue constructs by 3D bioprinting of cell-laden microcarriers.

PubMed

Levato, Riccardo; Visser, Jetze; Planell, Josep A; Engel, Elisabeth; Malda, Jos; Mateos-Timoneda, Miguel A

2014-09-01

Bioprinting allows the fabrication of living constructs with custom-made architectures by spatially controlled deposition of multiple bioinks. This is important for the generation of tissue, such as osteochondral tissue, which displays a zonal composition in the cartilage domain supported by the underlying subchondral bone. Challenges in fabricating functional grafts of clinically relevant size include the incorporation of cues to guide specific cell differentiation and the generation of sufficient cells, which is hard to obtain with conventional cell culture techniques. A novel strategy to address these demands is to combine bioprinting with microcarrier technology. This technology allows for the extensive expansion of cells, while they form multi-cellular aggregates, and their phenotype can be controlled. In this work, living constructs were fabricated via bioprinting of cell-laden microcarriers. Mesenchymal stromal cell (MSC)-laden polylactic acid microcarriers, obtained via static culture or spinner flask expansion, were encapsulated in gelatin methacrylamide-gellan gum bioinks, and the printability of the composite material was studied. This bioprinting approach allowed for the fabrication of constructs with high cell concentration and viability. Microcarrier encapsulation improved the compressive modulus of the hydrogel constructs, facilitated cell adhesion, and supported osteogenic differentiation and bone matrix deposition by MSCs. Bilayered osteochondral models were fabricated using microcarrier-laden bioink for the bone compartment. These findings underscore the potential of this new microcarrier-based biofabrication approach for bone and osteochondral constructs.

Combination of Polymeric Supports and Drug Delivery Systems for Osteochondral Regeneration.

PubMed

Rojo, Luis

2018-01-01

Musculoskeletal conditions have been defined by European National Health systems as one of the key themes which should be featured during the present decade as a consequence of the significant healthcare and social support costs. Among others, articular cartilage degeneration due to traumatic and degenerative lesion injury or other pathologies commonly results in the development of musculoskeletal disorders such as osteoarthritis and arthritis rheumatoid, eventually leading to progressive articular cartilage and joint destruction especially at osteochondral interphase, that account for more disability among the elderly than any other diseases constituting a global social challenge that needs a multidisciplinary response from the scientific community. Current treatments for damaged osteoarthritic joint cartilage include the use of disease-modifying drugs and ultimately joint arthroplasty as unavoidable surgical intervention due to the limited ability of articular cartilage to self-regenerate. However, potential future regenerative therapies based on tissue engineering strategies are likely to become more important to facilitate the recruitment of repairing cells and improve musculoskeletal metabolism. In addition, emerging bioprinting technologies in combination with implemented manufacturing techniques such electrospinning or cryogelation processes have permitted the development of new tissue substitutes with precise control of sizes and shapes to recreate the complex physiological, biomechanical and hieratical microstructure of osteochondral interphases. Thus, this chapter will provide an upgrade on the state of the art focusing the most relevant developments on polymer scaffolds and drug delivery systems for osteochondral regeneration.

Three-dimensional polycaprolactone-hydroxyapatite scaffolds combined with bone marrow cells for cartilage tissue engineering.

PubMed

Wei, Bo; Yao, Qingqiang; Guo, Yang; Mao, Fengyong; Liu, Shuai; Xu, Yan; Wang, Liming

2015-08-01

The goal of this study was to investigate the chondrogenic potential of three-dimensional polycaprolactone-hydroxyapatite (PCL-HA) scaffolds loaded with bone marrow cells in vitro and the effect of PCL-HA scaffolds on osteochondral repair in vivo. Here, bone marrow was added to the prepared PCL-HA scaffolds and cultured in chondrogenic medium for 10 weeks. Osteochondral defects were created in the trochlear groove of 29 knees in 17 New Zealand white rabbits, which were then divided into four groups that underwent: implantation of PCL-HA scaffolds (left knee, n = 17; Group 1), microfracture (right knee, n = 6; Group 2), autologous osteochondral transplantation (right knee, n = 6; Group 3), and no treatment (right knee, n = 5; Control). Extracellular matrix produced by bone marrow cells covered the surface and filled the pores of PCL-HA scaffolds after 10 weeks in culture. Moreover, many cell-laden cartilage lacunae were observed, and cartilage matrix was concentrated in the PCL-HA scaffolds. After a 12-week repair period, Group 1 showed excellent vertical and lateral integration with host bone, but incomplete cartilage regeneration and matrix accumulation. An uneven surface of regenerated cartilage and reduced distribution of cartilage matrix were observed in Group 2. In addition, abnormal bone growth and unstable integration between repaired and host tissues were detected. For Group 3, the integration between transplanted and host cartilage was interrupted. Our findings indicate that the PCL-HA scaffolds loaded with bone marrow cells improved chondrogenesis in vitro and implantation of PCL-HA scaffolds for osteochondral repairenhanced integration with host bone. However, cartilage regeneration remained unsatisfactory. The addition of trophic factors or the use of precultured cell-PCL-HA constructs for accelerated osteochondral repair requires further investigation. © The Author(s) 2015.

Toward Mass Customization in the Age of Information: The Case for Open Engineering Systems

NASA Technical Reports Server (NTRS)

Simpson, Timothy W.; Lautenschlager, Uwe; Mistree, Farrokh

1997-01-01

In the Industrial Era, manufacturers used "dedicated" engineering systems to mass produce their products. In today's increasingly competitive markets, the trend is toward mass customization, something that becomes increasingly feasible when modern information technologies are used to create open engineering systems. Our focus is on how designers can provide enhanced product flexibility and variety (if not fully customized products) through the development of open engineering systems. After presenting several industrial examples, we anchor our new systems philosophy with two real engineering applications. We believe that manufacturers who adopt open systems will achieve competitive advantage in the Information Age.

Application of computer graphics in the design of custom orthopedic implants.

PubMed

Bechtold, J E

1986-10-01

Implementation of newly developed computer modelling techniques and computer graphics displays and software have greatly aided the orthopedic design engineer and physician in creating a custom implant with good anatomic conformity in a short turnaround time. Further advances in computerized design and manufacturing will continue to simplify the development of custom prostheses and enlarge their niche in the joint replacement market.

Application of Kansei engineering and data mining in the Thai ceramic manufacturing

NASA Astrophysics Data System (ADS)

Kittidecha, Chaiwat; Yamada, Koichi

2018-01-01

Ceramic is one of the highly competitive products in Thailand. Many Thai ceramic companies are attempting to know the customer needs and perceptions for making favorite products. To know customer needs is the target of designers and to develop a product that must satisfy customers. This research is applied Kansei Engineering (KE) and Data Mining (DM) into the customer driven product design process. KE can translate customer emotions into the product attributes. This method determines the relationships between customer feelings or Kansei words and the design attributes. Decision tree J48 and Class association rule which implemented through Waikato Environment for Knowledge Analysis (WEKA) software are used to generate a predictive model and to find the appropriate rules. In this experiment, the emotion scores were rated by 37 participants for training data and 16 participants for test data. 6 Kansei words were selected, namely, attractive, ease of drinking, ease of handing, quality, modern and durable. 10 mugs were selected as product samples. The results of this study indicate that the proposed models and rules can interpret the design product elements affecting the customer emotions. Finally, this study provides useful understanding for the application DM in KE and can be applied to a variety of design cases.

26 CFR 1.460-2 - Long-term manufacturing contracts.

Code of Federal Regulations, 2011 CFR

2011-04-01

... specific customer, a taxpayer must consider the extent to which research, development, design, engineering... substantial amount of research, design, and engineering to produce, C determines that the equipment is a... produce, will be delivered to B in 2003. C determines that the research, design, engineering, retooling...

26 CFR 1.263A-1 - Uniform capitalization of costs.

Code of Federal Regulations, 2014 CFR

2014-04-01

... or facilities. (P) Engineering and design costs. Engineering and design costs include pre-production costs, such as costs attributable to research, experimental, engineering, and design activities (to the... customer demand. (9) Research and experimental expenditures. See section 263A(c)(2) for an exception for...

Enhancement of healing in osteochondral defects by collagen sponge implants.

PubMed

Speer, D P; Chvapil, M; Volz, R G; Holmes, M D

1979-10-01

Implants of porous, highly cross-linked collagen sponge (CS) were tested for their capacity to enhance the healing of osteochondral defects in rabbits. Comparison was made to the healing of similar defects with polyvinyl alcohol sponge (PVAS) implants and with no implants (CONT). Evaluation was carried out up to 44 weeks following implantation and included observation of host cellular response, biodegradability of implant, gross appearance of restored joint surface, collagenous architecture of repair tissue, and properties of the junctions of implants and host articular cartilage, subchondral bone, and medullary bone. Collagen sponge proved most effective in promoting healing of osteochondral defects with fibrous and fibrocartilaginous tissue over restored subchondral bone. Collagen sponge showed many desirable properties as a potential material for biologic resurfacing of damaged joints. These properties included porosity, biodegradability, biocompatability, ability to mechanically protect cells and matrix while directing cell ingrowth, and an available chemical technology for modifying its biomechanical and biological properties. Comparative analysis of results of healing of CS, PVAS, and CONT osteochondral defects suggest rational design criteria for implant materials to improve their effectiveness in restoration of articular surfaces.

40 CFR 1045.105 - What exhaust emission standards must my sterndrive/inboard engines meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

... the fuel type on which the engines in the engine family are designed to operate. You must meet the... data, such as data from research engines or similar engine models that are already in production. Your... for the engine or its components, and any relevant customer design specifications. Your demonstration...

40 CFR 1045.105 - What exhaust emission standards must my sterndrive/inboard engines meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

... the fuel type on which the engines in the engine family are designed to operate. You must meet the... data, such as data from research engines or similar engine models that are already in production. Your... for the engine or its components, and any relevant customer design specifications. Your demonstration...

40 CFR 1045.105 - What exhaust emission standards must my sterndrive/inboard engines meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

... the fuel type on which the engines in the engine family are designed to operate. You must meet the... data, such as data from research engines or similar engine models that are already in production. Your... for the engine or its components, and any relevant customer design specifications. Your demonstration...

40 CFR 1045.105 - What exhaust emission standards must my sterndrive/inboard engines meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

... the fuel type on which the engines in the engine family are designed to operate. You must meet the... data, such as data from research engines or similar engine models that are already in production. Your... for the engine or its components, and any relevant customer design specifications. Your demonstration...

40 CFR 1045.105 - What exhaust emission standards must my sterndrive/inboard engines meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

... the fuel type on which the engines in the engine family are designed to operate. You must meet the... data, such as data from research engines or similar engine models that are already in production. Your... for the engine or its components, and any relevant customer design specifications. Your demonstration...

Systems engineering for very large systems

NASA Technical Reports Server (NTRS)

Lewkowicz, Paul E.

1993-01-01

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

Systems engineering for very large systems

NASA Astrophysics Data System (ADS)

Lewkowicz, Paul E.

Very large integrated systems have always posed special problems for engineers. Whether they are power generation systems, computer networks or space vehicles, whenever there are multiple interfaces, complex technologies or just demanding customers, the challenges are unique. 'Systems engineering' has evolved as a discipline in order to meet these challenges by providing a structured, top-down design and development methodology for the engineer. This paper attempts to define the general class of problems requiring the complete systems engineering treatment and to show how systems engineering can be utilized to improve customer satisfaction and profit ability. Specifically, this work will focus on a design methodology for the largest of systems, not necessarily in terms of physical size, but in terms of complexity and interconnectivity.

3D Printing and Biofabrication for Load Bearing Tissue Engineering.

PubMed

Jeong, Claire G; Atala, Anthony

2015-01-01

Cell-based direct biofabrication and 3D bioprinting is becoming a dominant technological platform and is suggested as a new paradigm for twenty-first century tissue engineering. These techniques may be our next step in surpassing the hurdles and limitations of conventional scaffold-based tissue engineering, and may offer the industrial potential of tissue engineered products especially for load bearing tissues. Here we present a topically focused review regarding the fundamental concepts, state of the art, and perspectives of this new technology and field of biofabrication and 3D bioprinting, specifically focused on tissue engineering of load bearing tissues such as bone, cartilage, osteochondral and dental tissue engineering.

Sol gel-derived hydroxyapatite films over porous calcium polyphosphate substrates for improved tissue engineering of osteochondral-like constructs.

PubMed

Lee, Whitaik David; Gawri, Rahul; Pilliar, Robert M; Stanford, William L; Kandel, Rita A

2017-10-15

Integration of in vitro-formed cartilage on a suitable substrate to form tissue-engineered implants for osteochondral defect repair is a considerable challenge. In healthy cartilage, a zone of calcified cartilage (ZCC) acts as an intermediary for mechanical force transfer from soft to hard tissue, as well as an effective interlocking structure to better resist interfacial shear forces. We have developed biphasic constructs that consist of scaffold-free cartilage tissue grown in vitro on, and interdigitated with, porous calcium polyphosphate (CPP) substrates. However, as CPP degrades, it releases inorganic polyphosphates (polyP) that can inhibit local mineralization, thereby preventing the formation of a ZCC at the interface. Thus, we hypothesize that coating CPP substrate with a layer of hydroxyapatite (HA) might prevent or limit this polyP release. To investigate this we tested both inorganic or organic sol-gel processing methods, asa barrier coating on CPP substrate to inhibit polyP release. Both types of coating supported the formation of ZCC in direct contact with the substrate, however the ZCC appeared more continuous in the tissue formed on the organic HA sol gel coated CPP. Tissues formed on coated substrates accumulated comparable quantities of extracellular matrix and mineral, but tissues formed on organic sol-gel (OSG)-coated substrates accumulated less polyP than tissues formed on inorganic sol-gel (ISG)-coated substrates. Constructs formed with OSG-coated CPP substrates had greater interfacial shear strength than those formed with ISG-coated and non-coated substrates. These results suggest that the OSG coating method can modify the location and distribution of ZCC and can be used to improve the mechanical integrity of tissue-engineered constructs formed on porous CPP substrates. Articular cartilage interfaces with bone through a zone of calcified cartilage. This study describes a method to generate an "osteochondral-like" implant that mimics this organization using isolated deep zone cartilage cells and a sol-gel hydroxyapatite coated bone substitute material composed of calcium polyphosphate (CPP). Developing a layer of calcified cartilage at the interface should contribute to enhancing the success of this "osteochondral-like" construct following implantation to repair cartilage defects. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

TAIPAN fibre feed and spectrograph: engineering overview

NASA Astrophysics Data System (ADS)

Staszak, Nicholas F.; Lawrence, Jon; Zhelem, Ross; Content, Robert; Churilov, Vladimir; Case, Scott; Brown, Rebecca; Hopkins, Andrew M.; Kuehn, Kyler; Pai, Naveen; Klauser, Urs; Nichani, Vijay; Waller, Lew

2016-07-01

TAIPAN will conduct a stellar and galaxy survey of the Southern sky. The TAIPAN positioner is being developed as a prototype for the MANIFEST instrument on the GMT. The TAIPAN Spectrograph is an AAO designed all-refractive 2-arm design that delivers a spectral resolution of R>2000 over the wavelength range 370-870 nm. It is fed by a custom fibre cable from the TAIPAN Starbugs positioner. The design for TAIPAN incorporates 150 optical fibres (with an upgrade path to 300). Presented is an engineering overview of the UKST Fibre Cable design used to support Starbugs, the custom slit design, and the overall design and build plan for the TAIPAN Spectrograph.

Design and development of the Waukesha Custom Engine Control Air/Fuel Module

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moss, D.W.

1996-12-31

The Waukesha Custom Engine Control Air/Fuel Module (AFM) is designed to control the air-fuel ratio for all Waukesha carbureted, gaseous fueled, industrial engine. The AFM is programmed with a personal computer to run in one of four control modes: catalyst, best power, best economy, or lean-burn. One system can control naturally aspirated, turbocharged, in-line or vee engines. The basic system consists of an oxygen sensing system, intake manifold pressure transducer, electronic control module, actuator and exhaust thermocouple. The system permits correct operation of Waukesha engines in spite of changes in fuel pressure or temperature, engine load or speed, and fuelmore » composition. The system utilizes closed loop control and is centered about oxygen sensing technology. An innovative approach to applying oxygen sensors to industrial engines provides very good performance, greatly prolongs sensor life, and maintains sensor accuracy. Design considerations and operating results are given for application of the system to stationary, industrial engines operating on fuel gases of greatly varying composition.« less

Metal Matrix Composites: Custom-made Materials for Automotive and Aerospace Engineering

NASA Astrophysics Data System (ADS)

Kainer, Karl U.

2006-02-01

Since the properties of MMCs can be directly designed "into" the material, they can fulfill all the demands set by design engineers. This book surveys the latest results and development possibilities for MMCs as engineering and functional materials, making it of utmost value to all materials scientists and engineers seeking in-depth background information on the potentials these materials have to offer in research, development and design engineering.

Two Patients with Osteochondral Injury of the Weight-Bearing Portion of the Lateral Femoral Condyle Associated with Lateral Dislocation of the Patella

PubMed Central

Inoue, Hiroaki; Atsumi, Satoru; Ichimaru, Shohei; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2014-01-01

Complications of patellar dislocation include osteochondral injury of the lateral femoral condyle and patella. Most cases of osteochondral injury occur in the anterior region, which is the non-weight-bearing portion of the lateral femoral condyle. We describe two patients with osteochondral injury of the weight-bearing surface of the lateral femoral condyle associated with lateral dislocation of the patella. The patients were 18- and 11-year-old females. Osteochondral injury occurred on the weight-bearing surface distal to the lateral femoral condyle. The presence of a free osteochondral fragment and osteochondral injury of the lateral femoral condyle was confirmed on MRI and reconstruction CT scan. Treatment consisted of osteochondral fragment fixation or microfracture, as well as patellar stabilization. Osteochondral injury was present in the weight-bearing portion of the lateral femoral condyle in both patients, suggesting that the injury was caused by friction between the patella and lateral femoral condyle when the patella was dislocated or reduced at about 90° flexion of the knee joint. These findings indicate that patellar dislocation may occur and osteochondral injury may extend to the weight-bearing portion of the femur even in deep flexion, when the patella is stabilized on the bones of the femoral groove. PMID:25506015

Osteochondral Tissue Cell Viability Is Affected by Total Impulse during Impaction Grafting

PubMed Central

Balash, Paul; Kang, Richard W.; Schwenke, Thorsten; Cole, Brian J.; Wimmer, Markus A.

2010-01-01

Objective: Osteochondral graft transplantation has garnered significant attention because of its ability to replace the lesion with true hyaline cartilage. However, surgical impaction of the graft to anchor it into the defect site can be traumatic and lead to cell death and cartilage degeneration. This study aimed to test the hypothesis that increasing impulse magnitude during impaction of osteochondral plugs has a direct effect on loss of cell viability. Design: In this controlled laboratory study, the impaction force was kept constant while the impulse was varied. Ninety-six osteochondral plugs were extracted from the trochlea of bovine stifle joints and were randomly assigned into 3 experimental and 1 (nonimpacted) control group. The transferred impulse of the experimental groups reflected the median and the lower and upper quartiles of preceding clinical measurements. Data were obtained at day 0, day 4, and day 8; at each point, cell viability was assessed using the Live/Dead staining kit and histological assessments were performed to visualize matrix structural changes. Results: After impaction, cartilage samples stayed intact and did not show any histological signs of matrix disruption. As expected, higher impulse magnitudes introduced more cell death; however, this relationship was lost at day 8 after impaction. Conclusion: Impulse magnitude has a direct effect on cell viability of the graft. Because impulse magnitude is mostly governed by the press-fit characteristics of the recipient site, this study aids in the definition of optimal insertion conditions for osteochondral grafts. PMID:26069558

CASIS Fact Sheet: Hardware and Facilities

NASA Technical Reports Server (NTRS)

Solomon, Michael R.; Romero, Vergel

2016-01-01

Vencore is a proven information solutions, engineering, and analytics company that helps our customers solve their most complex challenges. For more than 40 years, we have designed, developed and delivered mission-critical solutions as our customers' trusted partner. The Engineering Services Contract, or ESC, provides engineering and design services to the NASA organizations engaged in development of new technologies at the Kennedy Space Center. Vencore is the ESC prime contractor, with teammates that include Stinger Ghaffarian Technologies, Sierra Lobo, Nelson Engineering, EASi, and Craig Technologies. The Vencore team designs and develops systems and equipment to be used for the processing of space launch vehicles, spacecraft, and payloads. We perform flight systems engineering for spaceflight hardware and software; develop technologies that serve NASA's mission requirements and operations needs for the future. Our Flight Payload Support (FPS) team at Kennedy Space Center (KSC) provides engineering, development, and certification services as well as payload integration and management services to NASA and commercial customers. Our main objective is to assist principal investigators (PIs) integrate their science experiments into payload hardware for research aboard the International Space Station (ISS), commercial spacecraft, suborbital vehicles, parabolic flight aircrafts, and ground-based studies. Vencore's FPS team is AS9100 certified and a recognized implementation partner for the Center for Advancement of Science in Space (CASIS

Improving Customer Satisfaction in an R and D Environment

NASA Technical Reports Server (NTRS)

Alexander, Anita; Liou, Y. H. Andrew

1998-01-01

Satisfying customer needs is critical to the sustained competitive advantage of service suppliers. It is therefore important to understand the types of customer needs which, if fulfilled or exceeded, add value and contribute to overall customer satisfaction. This study identifies the needs of various research and development (R&D) customers who contract for engineering and design support services. The Quality Function Deployment (QFD) process was used to organize and translate each customer need into performance measures that, if implemented, can improve customer satisfaction. This study also provides specific performance measures that will more accurately guide the efforts of the engineering supplier. These organizations can either implement the QFD methodology presented herein or extract a few performance measures that are specific to the quality dimensions in need of improvement. Listening to 'what' customers talk about is a good first start.

Controlled Release Strategies for Bone, Cartilage, and Osteochondral Engineering—Part I: Recapitulation of Native Tissue Healing and Variables for the Design of Delivery Systems

PubMed Central

Santo, Vítor E.; Mano, João F.; Reis, Rui L.

2013-01-01

The potential of growth factors to stimulate tissue healing through the enhancement of cell proliferation, migration, and differentiation is undeniable. However, critical parameters on the design of adequate carriers, such as uncontrolled spatiotemporal presence of bioactive factors, inadequate release profiles, and supraphysiological dosages of growth factors, have impaired the translation of these systems onto clinical practice. This review describes the healing cascades for bone, cartilage, and osteochondral interface, highlighting the role of specific growth factors for triggering the reactions leading to tissue regeneration. Critical criteria on the design of carriers for controlled release of bioactive factors are also reported, focusing on the need to provide a spatiotemporal control over the delivery and presentation of these molecules. PMID:23268651

Gas Station Pricing Game: A Lesson in Engineering Economics and Business Strategies.

ERIC Educational Resources Information Center

Sin, Aaron; Center, Alfred M.

2002-01-01

Describes an educational game designed for engineering majors that demonstrates engineering economics and business strategies, specifically the concepts of customer perception of product value, convenience, and price differentiation. (YDS)

Use of Synthetic Osteochondral Implants to Treat Bilateral Shoulder Osteochondritis Dissecans in a Dog.

PubMed

Danielski, Alan; Farrell, Michael

2018-06-20

 An 8-month-old American Bulldog was presented for assessment of bilateral thoracic limb lameness. Computed tomographic imaging revealed large, deep osteochondritis dissecans lesions in both humeral heads.  The osteochondritis dissecans lesions were debrided and the exposed subchondral defects were prepared to receive synthetic grafts. Circular implants consisting of a surface layer of polycarbonate urethane and a deep layer of lattice-type titanium were implanted into the osteochondral defects to reconstruct the articular surface topography. Follow-up clinical examination 1.5, 3 and 9months postoperatively revealed a lack of signs of shoulder pain and resolution of thoracic limb lameness. Nine-month follow-up radiographs showed radiographic evidence of osteointegration of both implants.  Synthetic osteochondral implantation in the caudocentral aspect of the humeral head appeared technically feasible and effective in resolving lameness caused by humeral head osteochondritis dissecans. Schattauer GmbH Stuttgart.

[Double-sided juvenile osteochondritis dissecans of the lateral femoral condyle in a 15-year-old boy].

PubMed

Nordkamp, R A G; van Rensen, I H T; Sala, H A G M; van Mourik, J B A

2007-07-21

A 15-year-old boy of Turkish origin presented with a painful swollen left knee. An X-ray revealed osteochondritis dissecans of the lateral femoral condyle. Arthrotomy was performed and the fragment was fixated with tissue glue and 2 absorbable pins. Eight months later, a large recurrent osteochondral fragment of the lateral femoral condyle was seen on X-ray. The patient was re-operated, during which operation the fragment was found and fixated with three compression screws. One year after the first operation the patient developed similar complaints in the contralateral knee; this knee also contained osteochondral fragments necessitating surgery. Osteochondritis dissecans of the knee is a multifactorial disease in which part of the cartilage of the femoral condyle becomes unattached from the subchondral stratum, usually on the lateral side of the medial femoral condyle. Initially, an inflammatory reaction was thought to be the cause of osteochondritis dissecans. Because of the lack of white blood cells, a previous trauma is a better explanation for the ultimate loosening of the cartilage. The treatments that are described for osteochondritis dissecans are conservative treatment, operative fixation, with or without subsequent chondrocyte transplantation or osteochondral autograft transplantation, and finally microfracturing.

VLSI (Very Large Scale Integrated) Design of a 16 Bit Very Fast Pipelined Carry Look Ahead Adder.

DTIC Science & Technology

1983-09-01

the ability for systems engineers to custom design digital integrated circuits. Until recently, the design of integrated circuits has been...traditionally carried out by a select group of logic designers working in semiconductor laboratories. Systems engineers had to "make do" or "fit in" the...products of these labs to realize their designs. The systems engineers had little participation in the actual design of the chip. The MED and CONWAY design

Design Standards for Engineered Tissues

PubMed Central

Nawroth, Janna C.; Parker, Kevin Kit

2013-01-01

Traditional technologies are required to meet specific, quantitative standards of safety and performance. In tissue engineering, similar standards will have to be developed to enable routine clinical use and customized tissue fabrication. In this essay, we discuss a framework of concepts leading towards general design standards for tissue-engineering, focusing in particular on systematic design strategies, control of cell behavior, physiological scaling, fabrication modes and functional evaluation. PMID:23267860

Osteochondral transplantation of the talus: long-term clinical and magnetic resonance imaging evaluation.

PubMed

Imhoff, Andreas B; Paul, Jochen; Ottinger, Benjamin; Wörtler, Klaus; Lämmle, Lena; Spang, Jeffrey; Hinterwimmer, Stefan

2011-07-01

Osteochondral lesions of the ankle are a common injury after ankle sprains, especially in young and active patients. The Osteochondral Autograft Transfer System (OATS) is the only 1-step surgical technique designed to replace the entire osteochondral unit. This study was conducted to evaluate the long-term clinical and radiographic outcomes of the OATS procedure for the talus and compare the results of patients who have had prior surgical interventions with patients for whom OATS represents the primary surgical treatment. Case series; Level of evidence, 4. The authors retrospectively analyzed 26 talus OATS procedures (25 patients) with an average follow-up of 84 months (range, 53-124 months); 9 patients had OATS as a second surgical intervention. The patients completed the American Orthopaedic Foot & Ankle Society (AOFAS) and Tegner scores plus the visual analog scale (VAS) preoperatively and at follow-up. Magnetic resonance imaging examinations were conducted on a 1.5-T whole-body magnet that assessed transplant congruency, adjacent surface of the talus, the corresponding distal tibia, and joint effusion. The authors found significant increases for the AOFAS score (50 to 78 points, P < .01) and the Tegner score (3.1 to 3.7, P < .05) and a significant decrease for the VAS (7.8 to 1.5, P < .01) from preoperative to postoperative. Patients with normal integration or minor incongruity of the transplant on magnetic resonance imaging (81%) had significantly better AOFAS scores (P = .03). Other magnetic resonance imaging criteria did not predict clinical results. Patients for whom OATS represented a second procedure had significantly worse clinical AOFAS and Tegner scores plus a higher VAS. Long-term clinical and magnetic resonance imaging results after osteochondral transplantation are good and patients significantly benefit from this surgery. Magnetic resonance imaging should not be a routine control but appears to be indicated when clinical symptoms persist after osteochondral transplantation.

The Application of Concurrent Engineering Tools and Design Structure Matrix in Designing Tire

NASA Astrophysics Data System (ADS)

Ginting, Rosnani; Fachrozi Fitra Ramadhan, T.

2016-02-01

The development of automobile industry in Indonesia is growing rapidly. This phenomenon causes companies related to the automobile industry such as tire industry must develop products based on customers’ needs and considering the timeliness of delivering the product to the customer. It could be reached by applying strategic planning in developing an integrated concept of product development. This research was held in PT. XYZ that applied the sequential approach in designing and developing products. The need to improve in one stage of product development could occur re-designing that needs longer time in developing a new product. This research is intended to get an integrated product design concept of tire pertaining to the customer's needs using Concurrent Engineering Tools by implementing the two-phased of product development. The implementation of Concurrent Engineering approach results in applying the stage of project planning, conceptual design, and product modules. The product modules consist of four modules that using Product Architecture - Design Structure Matrix to ease the designing process of new product development.

Pratt and Whitney Overview and Advanced Health Management Program

NASA Technical Reports Server (NTRS)

Inabinett, Calvin

2008-01-01

Hardware Development Activity: Design and Test Custom Multi-layer Circuit Boards for use in the Fault Emulation Unit; Logic design performed using VHDL; Layout power system for lab hardware; Work lab issues with software developers and software testers; Interface with Engine Systems personnel with performance of Engine hardware components; Perform off nominal testing with new engine hardware.

Osteochondral allograft.

PubMed

Torrie, Arissa M; Kesler, William W; Elkin, Joshua; Gallo, Robert A

2015-12-01

Over the past decade, osteochondral allograft transplantation has soared in popularity. Advances in storage techniques have demonstrated improved chondrocyte viability at longer intervals and allowed for potential of increased graft availability. Recent studies have stratified outcomes according to location and etiology of the chondral or osteochondral defect. Unipolar lesions generally have favorable outcomes with promising 10-year survival rates. Though those undergoing osteochondral allograft transplantation often require reoperation, patient satisfaction remains high.

Management of Osteochondritis Dissecans of the Femoral Condyle.

PubMed

Shea, Kevin G; Carey, James L; Brown, Gregory A; Murray, Jayson N; Pezold, Ryan; Sevarino, Kaitlyn S

2016-09-01

The American Academy of Orthopaedic Surgeons has developed the Appropriate Use Criteria (AUC) document Management of Osteochondritis Dissecans of the Femoral Condyle. Evidence-based information, in conjunction with the clinical expertise of physicians, was used to develop the criteria to improve patient care and obtain the best outcomes while considering the subtleties and distinctions necessary in making clinical decisions. The AUC clinical patient scenarios were derived from patient indications that generally accompany osteochondritis dissecans of the femoral condyle, as well as from current evidence-based clinical practice guidelines and supporting literature. The 64 patient scenarios and 12 treatments were developed by the Writing Panel, a group of clinicians who are specialists in this AUC topic. Lastly, a separate, multidisciplinary Voting Panel (made up of specialists and nonspecialists) rated the appropriateness of treatment of each patient scenario using a 9-point scale to designate a treatment as Appropriate (median rating, 7 to 9), May Be Appropriate (median rating, 4 to 6), or Rarely Appropriate (median rating, 1 to 3).

Using computed tomography and 3D printing to construct custom prosthetics attachments and devices.

PubMed

Liacouras, Peter C; Sahajwalla, Divya; Beachler, Mark D; Sleeman, Todd; Ho, Vincent B; Lichtenberger, John P

2017-01-01

The prosthetic devices the military uses to restore function and mobility to our wounded warriors are highly advanced, and in many instances not publically available. There is considerable research aimed at this population of young patients who are extremely active and desire to take part in numerous complex activities. While prosthetists design and manufacture numerous devices with standard materials and limb assemblies, patients often require individualized prosthetic design and/or modifications to enable them to participate fully in complex activities. Prosthetists and engineers perform research and implement digitally designs in collaboration to generate equipment for their patient's rehabilitation needs. 3D printing allows for these devices to be manufactured from an array of materials ranging from plastic to titanium alloy. Many designs require form fitting to a prosthetic socket or a complex surface geometry. Specialty items can be scanned using computed tomography and digitally reconstructed to produce a virtual 3D model the engineer can use to design the necessary features of the desired prosthetic, device, or attachment. Completed devices are tested for fit and function. Numerous custom prostheses and attachments have been successfully translated from the research domain to clinical reality, in particular, those that feature the use of computed tomography (CT) reconstructions. The purpose of this project is to describe the research pathways to implementation for the following clinical designs: sets of bilateral hockey skates; custom weightlifting prosthetic hands; and a wine glass holder. This article will demonstrate how to incorporate CT imaging and 3D printing in the design and manufacturing process of custom attachments and assistive technology devices. Even though some of these prosthesis attachments may be relatively simple in design to an engineer, they have an enormous impact on the lives of our wounded warriors.

Current concepts: tissue engineering and regenerative medicine applications in the ankle joint

PubMed Central

Correia, S. I.; Pereira, H.; Silva-Correia, J.; Van Dijk, C. N.; Espregueira-Mendes, J.; Oliveira, J. M.; Reis, R. L.

2014-01-01

Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in general population as well as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior to implantation into the patient. Particularly in the ankle, which is subject to many different injuries (e.g. acute, chronic, traumatic and degenerative), there is still no definitive and feasible answer to ‘conventional’ methods. This review aims to provide current concepts of TERM applications to ankle injuries under preclinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterial design and scaffold processing with potential use in osteochondral ankle lesions. PMID:24352667

Current concepts: tissue engineering and regenerative medicine applications in the ankle joint.

PubMed

Correia, S I; Pereira, H; Silva-Correia, J; Van Dijk, C N; Espregueira-Mendes, J; Oliveira, J M; Reis, R L

2014-03-06

Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in general population as well as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior to implantation into the patient. Particularly in the ankle, which is subject to many different injuries (e.g. acute, chronic, traumatic and degenerative), there is still no definitive and feasible answer to 'conventional' methods. This review aims to provide current concepts of TERM applications to ankle injuries under preclinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterial design and scaffold processing with potential use in osteochondral ankle lesions.

ROBOTICS IN HAZARDOUS ENVIRONMENTS - REAL DEPLOYMENTS BY THE SAVANNAH RIVER NATIONAL LABORATORY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kriikku, E.; Tibrea, S.; Nance, T.

The Research & Development Engineering (R&DE) section in the Savannah River National Laboratory (SRNL) engineers, integrates, tests, and supports deployment of custom robotics, systems, and tools for use in radioactive, hazardous, or inaccessible environments. Mechanical and electrical engineers, computer control professionals, specialists, machinists, welders, electricians, and mechanics adapt and integrate commercially available technology with in-house designs, to meet the needs of Savannah River Site (SRS), Department of Energy (DOE), and other governmental agency customers. This paper discusses five R&DE robotic and remote system projects.

Development of a Comprehensive Osteochondral Allograft MRI Scoring System (OCAMRISS) With Histopathologic, Micro–Computed Tomography, and Biomechanical Validation

PubMed Central

Pallante-Kichura, Andrea L.; Bae, Won C.; Du, Jiang; Statum, Sheronda; Wolfson, Tanya; Gamst, Anthony C.; Cory, Esther; Amiel, David; Bugbee, William D.; Sah, Robert L.; Chung, Christine B.

2014-01-01

Objective: To describe and apply a semiquantitative MRI scoring system for multifeature analysis of cartilage defect repair in the knee by osteochondral allografts and to correlate this scoring system with histopathologic, micro–computed tomography (µCT), and biomechanical reference standards using a goat repair model. Design: Fourteen adult goats had 2 osteochondral allografts implanted into each knee: one in the medial femoral condyle and one in the lateral trochlea. At 12 months, goats were euthanized and MRI was performed. Two blinded radiologists independently rated 9 primary features for each graft, including cartilage signal, fill, edge integration, surface congruity, calcified cartilage integrity, subchondral bone plate congruity, subchondral bone marrow signal, osseous integration, and presence of cystic changes. Four ancillary features of the joint were also evaluated, including opposing cartilage, meniscal tears, synovitis, and fat-pad scarring. Comparison was made with histologic and µCT reference standards as well as biomechanical measures. Interobserver agreement and agreement with reference standards was assessed. Cohen’s κ, Spearman’s correlation, and Kruskal-Wallis tests were used as appropriate. Results: There was substantial agreement (κ > 0.6, P < 0.001) for each MRI feature and with comparison against reference standards, except for cartilage edge integration (κ = 0.6). There was a strong positive correlation between MRI and reference standard scores (ρ = 0.86, P < 0.01). Osteochondral allograft MRI scoring system was sensitive to differences in outcomes between the types of allografts. Conclusions: We have described a comprehensive MRI scoring system for osteochondral allografts and have validated this scoring system with histopathologic and µCT reference standards as well as biomechanical indentation testing. PMID:24489999

26 CFR 1.263A-1 - Uniform capitalization of costs.

Code of Federal Regulations, 2013 CFR

2013-04-01

... costs. Engineering and design costs include pre-production costs, such as costs attributable to research, experimental, engineering, and design activities (to the extent that such amounts are not research and... customer demand. (9) Research and experimental expenditures. See section 263A(c)(2) for an exception for...

26 CFR 1.263A-1 - Uniform capitalization of costs.

Code of Federal Regulations, 2011 CFR

2011-04-01

... costs. Engineering and design costs include pre-production costs, such as costs attributable to research, experimental, engineering, and design activities (to the extent that such amounts are not research and... customer demand. (9) Research and experimental expenditures. See section 263A(c)(2) for an exception for...

26 CFR 1.263A-1 - Uniform capitalization of costs.

Code of Federal Regulations, 2012 CFR

2012-04-01

... costs. Engineering and design costs include pre-production costs, such as costs attributable to research, experimental, engineering, and design activities (to the extent that such amounts are not research and... customer demand. (9) Research and experimental expenditures. See section 263A(c)(2) for an exception for...

History of osteochondral allograft transplantation.

PubMed

Nikolaou, V S; Giannoudis, P V

2017-07-01

Osteochondral defects or injuries represent the most challenging entities to treat, especially when occur to young and active patients. For centuries, it has been recognized that such defects are almost impossible to treat. However, surgeons have never stopped the effort to develop reliable methods to restore articular cartilage and salvage the endangered joint function. Osteochondral allograft transplantation in human was first introduced by Eric Lexer in 1908. Since that era, several pioneers have been worked in the field of osteochondral allotransplantation, presenting and developing the basic research, the methodology and the surgical techniques. Herein we present in brief, the history and the early clinical results of osteochondral allograft transplantation in human. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characteristics of a semi-custom library development system

NASA Technical Reports Server (NTRS)

Yancey, M.; Cannon, R.

1990-01-01

Standard cell and gate array macro libraries are in common use with workstation computer aided design (CAD) tools for application specific integrated circuit (ASIC) semi-custom application and have resulted in significant improvements in the overall design efficiencies as contrasted with custom design methodologies. Similar design methodology enhancements in providing for the efficient development of the library cells is an important factor in responding to the need for continuous technology improvement. The characteristics of a library development system that provides design flexibility and productivity enhancements for the library development engineer as he provides libraries in the state-of-the-art process technologies are presented. An overview of Gould's library development system ('Accolade') is also presented.

Osteochondritis dissecans of the knee in a subadult from a medieval (ninth century A.D.) site in Croatia.

PubMed

Slaus, Mario; Cicvara-Pećina, Tatjana; Lucijanić, Ivica; Pećina, Marko; Stilinović, Davor

2010-06-01

Although osteochondritis dissecans of the knee has been known for a long time, we still do not fully understand why it develops. This prompted us to present and describe an example of osteochondritis dissecans identified in the Osteological Collection of the Croatian Academy of Sciences and Arts. The case of osteochondritis dissecans described in this report was recovered from the Gluvine kuće cemetery in the Dalmatian hinterland, approximately 28 km north-east of Split. A total of 77 graves were excavated and the individual exhibiting osteochondritis dissecans was recovered from grave number 16 that belongs to the younger phase of the cemetery that lasted during the second half of the 9th century A.D. Osteochondritis dissecans was noted in a subadult individual. The pathological changes consistent with osteochondritis dissecans are present on both medial femoral condyles. The lesion on the right femoral condyle is an oval crater-like defect with well defined margins and a porous floor of rough trabecular bone. The lesion on the left femoral condyle is basically, with two small provisions, identical to the one on the right side. The first is that it is slightly smaller, while the second is that unlike its antimere, it has a well preserved bone fragment that fits perfectly into the ostechondritic pit. Radiographic analyses of the femoral condyles support a diagnosis of osteochondritis dissecans and show a well-demarcated radiolucent defect in the articular surfaces of both joints surrounded by a thin sclerotic repair zone. According to the classification systems this degree of change corresponds to stage 3 or grade 3 osteochondritis dissecans--a detached but non-displaced fragment. Returning, for a second, to the opinion that prompted us to present this case, it is clear that during the last 1100 years there have been no significant morphological or radiological changes in the characteristics of osteochondritis dissecans.

ISO 9000 and/or Systems Engineering Capability Maturity Model?

NASA Technical Reports Server (NTRS)

Gholston, Sampson E.

2002-01-01

For businesses and organizations to remain competitive today they must have processes and systems in place that will allow them to first identify customer needs and then develop products/processes that will meet or exceed the customers needs and expectations. Customer needs, once identified, are normally stated as requirements. Designers can then develop products/processes that will meet these requirements. Several functions, such as quality management and systems engineering management are used to assist product development teams in the development process. Both functions exist in all organizations and both have a similar objective, which is to ensure that developed processes will meet customer requirements. Are efforts in these organizations being duplicated? Are both functions needed by organizations? What are the similarities and differences between the functions listed above? ISO 9000 is an international standard of goods and services. It sets broad requirements for the assurance of quality and for management's involvement. It requires organizations to document the processes and to follow these documented processes. ISO 9000 gives customers assurance that the suppliers have control of the process for product development. Systems engineering can broadly be defined as a discipline that seeks to ensure that all requirements for a system are satisfied throughout the life of the system by preserving their interrelationship. The key activities of systems engineering include requirements analysis, functional analysis/allocation, design synthesis and verification, and system analysis and control. The systems engineering process, when followed properly, will lead to higher quality products, lower cost products, and shorter development cycles. The System Engineering Capability Maturity Model (SE-CMM) will allow companies to measure their system engineering capability and continuously improve those capabilities. ISO 9000 and SE-CMM seem to have a similar objective, which is to document the organization's processes and certify to potential customers the capability of a supplier to control the processes that determine the quality of the product or services being produced. The remaining sections of this report examine the differences and similarities between ISO 9000 and SE-CMM and make recommendations for implementation.

Fresh Osteochondral Allograft Transplantation for Fractures of the Knee.

PubMed

Gracitelli, Guilherme C; Tirico, Luis Eduardo Passarelli; McCauley, Julie C; Pulido, Pamela A; Bugbee, William D

2017-04-01

Objective The purpose of this study was to evaluate functional outcomes and allograft survivorship among patients with knee fracture who underwent fresh osteochondral allograft (OCA) transplantation as a salvage treatment option. Design Retrospective analysis of prospectively collected data. Setting Department of Orthopaedic Surgery at one hospital. Patients Fresh OCAs were implanted for osteochondral lesions after knee fracture in 24 males and 15 females with an average age of 34 years. Twenty-nine lesions (74%) were tibial plateau fractures, 6 (15%) were femoral condyle fractures, and 4 (10%) were patella fractures. Main Outcome Measurements Clinical evaluation included modified Merle d'Aubigné-Postel (18-point), International Knee Documentation Committee, and Knee Society function scores, and patient satisfaction. Failure of OCA was defined as revision OCA or conversion to total knee arthroplasty (TKA). Results Nineteen of 39 knees (49%) had further surgery. Ten knees (26%) were considered OCA failures (3 OCA revisions, 6 TKA, and 1 patellectomy). Survivorship of the OCA was 82.6% at 5 years and 69.6% at 10 years. Among the 29 knees (74%) that had the OCA still in situ, median follow-up was 6.6 years. Pain and function improved from preoperative to latest follow-up; 83% of patients reported satisfaction with OCA results. Conclusion OCA transplantation is a useful salvage treatment option for osteochondral lesions caused by knee fracture. Although the reoperation rate was high, successful outcome was associated with significant clinical improvement.

Articular Cartilage Repair Through Muscle Cell-Based Tissue Engineering

DTIC Science & Technology

2011-03-01

defects display good cell survival and can differentiate into chondrocytes that improve the healing of articular cartilage. We also have observed that... self -renewal to their regenerative capacity after transplantation into the cartilage defects (Technical Objective #1). Next, we will determine the...osteochondral defects display good cell survival and can differentiate into chondrocytes that improve the healing of articular cartilage. We also have

Turbomachine Sealing and Secondary Flows. Part 1; Review of Sealing Performance, Customer, Engine Designer, and Research Issues

NASA Technical Reports Server (NTRS)

Hendricks, R. C.; Steinetz, B. M.; Braun, M. J.

2004-01-01

Although forces outside our control shape our industry, turbomachine sealing research, design, and customer agendas established in 1978 by Ludwig, Campbell, and Smith in terms of specific fuel consumption and performance remain as objectives today. Advances have been made because failures of the space shuttle main engine turbomachinery ushered in a new understanding of sealing in high-power-density systems. Further, it has been shown that changes in sealing, especially for high-pressure rotors, dramatically change the performance of the entire engine or turbomachine. Maintaining seal leakages and secondary flows within engine design specifications remains the most efficient and cost effective way to enhance performance and minimize maintenance costs. This three-part review summarizes experiences, ideas, successes, and failures by NASA and the U.S. aerospace industry in secondary flow management in advanced turbomachinery. Part 1 presents system sealing, part 2 system rotordynamics, and part 3 modeling, with some overlap of each part.

Design and manufacture of customized dental implants by using reverse engineering and selective laser melting technology.

PubMed

Chen, Jianyu; Zhang, Zhiguang; Chen, Xianshuai; Zhang, Chunyu; Zhang, Gong; Xu, Zhewu

2014-11-01

Recently a new therapeutic concept of patient-specific implant dentistry has been advanced based on computer-aided design/computer-aided manufacturing technology. However, a comprehensive study of the design and 3-dimensional (3D) printing of the customized implants, their mechanical properties, and their biomechanical behavior is lacking. The purpose of this study was to evaluate the mechanical and biomechanical performance of a novel custom-made dental implant fabricated by the selective laser melting technique with simulation and in vitro experimental studies. Two types of customized implants were designed by using reverse engineering: a root-analog implant and a root-analog threaded implant. The titanium implants were printed layer by layer with the selective laser melting technique. The relative density, surface roughness, tensile properties, bend strength, and dimensional accuracy of the specimens were evaluated. Nonlinear and linear finite element analysis and experimental studies were used to investigate the stress distribution, micromotion, and primary stability of the implants. Selective laser melting 3D printing technology was able to reproduce the customized implant designs and produce high density and strength and adequate dimensional accuracy. Better stress distribution and lower maximum micromotions were observed for the root-analog threaded implant model than for the root-analog implant model. In the experimental tests, the implant stability quotient and pull-out strength of the 2 types of implants indicated that better primary stability can be obtained with a root-analog threaded implant design. Selective laser melting proved to be an efficient means of printing fully dense customized implants with high strength and sufficient dimensional accuracy. Adding the threaded characteristic to the customized root-analog threaded implant design maintained the approximate geometry of the natural root and exhibited better stress distribution and primary stability. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Challenges in engineering large customized bone constructs.

PubMed

Forrestal, David P; Klein, Travis J; Woodruff, Maria A

2017-06-01

The ability to treat large tissue defects with customized, patient-specific scaffolds is one of the most exciting applications in the tissue engineering field. While an increasing number of modestly sized tissue engineering solutions are making the transition to clinical use, successfully scaling up to large scaffolds with customized geometry is proving to be a considerable challenge. Managing often conflicting requirements of cell placement, structural integrity, and a hydrodynamic environment supportive of cell culture throughout the entire thickness of the scaffold has driven the continued development of many techniques used in the production, culturing, and characterization of these scaffolds. This review explores a range of technologies and methods relevant to the design and manufacture of large, anatomically accurate tissue-engineered scaffolds with a focus on the interaction of manufactured scaffolds with the dynamic tissue culture fluid environment. Biotechnol. Bioeng. 2017;114: 1129-1139. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

National Science Foundation 1989 Engineering Senior Design Projects To Aid the Disabled.

ERIC Educational Resources Information Center

Enderle, John D., Ed.

Through the Bioengineering and Research to Aid the Disabled program of the National Science Foundation, design projects were awarded competitively to 16 universities. Senior engineering students at each of the universities constructed custom devices and software for disabled individuals. This compendium contains a description of each project in…

QFD emphasis of IME design

NASA Astrophysics Data System (ADS)

Erickson, C. M.; Martinez, A.

1993-06-01

The 1992 Integrated Modular Engine (IME) design concept, proposed to the Air Force Space Systems Division as a candidate for a National Launch System (NLS) upper stage, emphasized a detailed Quality Functional Deployment (QFD) procedure which set the basis for its final selection. With a list of engine requirements defined and prioritized by the customer, a QFD procedure was implemented where the characteristics of a number of engine and component configurations were assessed for degree of requirement satisfaction. The QFD process emphasized operability, cost, reliability and performance, with relative importance specified by the customer. Existing technology and near-term advanced technology were surveyed to achieve the required design strategies. In the process, advanced nozzles, advanced turbomachinery, valves, controls, and operational procedures were evaluated. The integrated arrangement of three conventional bell nozzle thrust chambers with two advanced turbopump sets selected as the configuration meeting all requirements was rated significantly ahead of the other candidates, including the Aerospike and horizontal flow nozzle configurations.

Application of FDM three-dimensional printing technology in the digital manufacture of custom edentulous mandible trays

PubMed Central

Chen, Hu; Yang, Xu; Chen, Litong; Wang, Yong; Sun, Yuchun

2016-01-01

The objective was to establish and evaluate a method for manufacture of custom trays for edentulous jaws using computer aided design and fused deposition modeling (FDM) technologies. A digital method for design the custom trays for edentulous jaws was established. The tissue surface data of ten standard mandibular edentulous plaster models, which was used to design the digital custom tray in a reverse engineering software, were obtained using a 3D scanner. The designed tray was printed by a 3D FDM printing device. Another ten hand-made custom trays were produced as control. The 3-dimentional surface data of models and custom trays was scanned to evaluate the accuracy of reserved impression space, while the difference between digitally made trays and hand-made trays were analyzed. The digitally made custom trays achieved a good matching with the mandibular model, showing higher accuracy than the hand-made ones. There was no significant difference of the reserved space between different models and its matched digitally made trays. With 3D scanning, CAD and FDM technology, an efficient method of custom tray production was established, which achieved a high reproducibility and accuracy. PMID:26763620

Engineering specification and system design for CAD/CAM of custom shoes: UMC project effort

NASA Technical Reports Server (NTRS)

Bao, Han P.

1991-01-01

The goal of this project is to supplement the footwear design system of North Carolina State University (NCSU) with a software module to design and manufacture a combination sole. The four areas of concentration were: customization of NASCAD (NASA Computer Aided Design) to the footwear project; use of CENCIT data; computer aided manufacturing activities; and beginning work for the bottom elements of shoes. The task of generating a software module for producing a sole was completed with a demonstrated product realization. The software written in C was delivered to NCSU for inclusion in their design system for custom footwear known as LASTMOD. The machining process of the shoe last was improved using a spiral tool path approach.

Stem Cells for Osteochondral Regeneration.

PubMed

Canadas, Raphaël F; Pirraco, Rogério P; Oliveira, J Miguel; Reis, Rui L; Marques, Alexandra P

2018-01-01

Stem cell research plays a central role in the future of medicine, which is mainly dependent on the advances on regenerative medicine (RM), specifically in the disciplines of tissue engineering (TE) and cellular therapeutics. All RM strategies depend upon the harnessing, stimulation, or guidance of endogenous developmental or repair processes in which cells have an important role. Among the most clinically challenging disorders, cartilage degeneration, which also affects subchondral bone becoming an osteochondral (OC) defect, is one of the most demanding. Although primary cells have been clinically applied, stem cells are currently seen as the promising tool of RM-related research because of its availability, in vitro proliferation ability, pluri- or multipotency, and immunosuppressive features. Being the OC unit, a transition from the bone to cartilage, mesenchymal stem cells (MSCs) are the main focus for OC regeneration. Promising alternatives, which can also be obtained from the patient or at banks and have great differentiation potential toward a wide range of specific cell types, have been reported. Still, ethical concerns and tumorigenic risk are currently under discussion and assessment. In this book chapter, we revise the existing stem cell-based approaches for engineering bone and cartilage, focusing on cell therapy and TE. Furthermore, 3D OC composites based on cell co-cultures are described. Finally, future directions and challenges still to be faced are critically discussed.

Quality Function Deployment for Large Systems

NASA Technical Reports Server (NTRS)

Dean, Edwin B.

1992-01-01

Quality Function Deployment (QFD) is typically applied to small subsystems. This paper describes efforts to extend QFD to large scale systems. It links QFD to the system engineering process, the concurrent engineering process, the robust design process, and the costing process. The effect is to generate a tightly linked project management process of high dimensionality which flushes out issues early to provide a high quality, low cost, and, hence, competitive product. A pre-QFD matrix linking customers to customer desires is described.

Femoral osteochondral fracture--a non-contact injury in martial arts? A case report.

PubMed Central

Mbubaegbu, C E; Percy, A J

1994-01-01

A report of a case of osteochondral fracture of the lateral femoral condyle in a patient doing a karate kick. The problems related to fixation of osteochondral fragments with protruding screws are highlighted and the suitability of Herbert screw fixation noted. Images Figure 1 Figure 2 Figure 3 PMID:8000822

Post-traumatic osteochondral ''loose body'' of the olecranon fossa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bassett, L.W.; Mirra, J.M.; Forrester, D.M.

1981-12-01

Three cases of intra-articular osteochondral bodies with the olecranon fossa are reported. All patients had had severe trauma to the elbow, and in each case an osteochondral fragment, nourished by the synovial fluid, became enlarged and finally lodged within the fossa. The radiological and pathological features and presumed pathogenesis are described.

Regulation of decellularized tissue remodeling via scaffold-mediated lentiviral delivery in anatomically-shaped osteochondral constructs.

PubMed

Rowland, Christopher R; Glass, Katherine A; Ettyreddy, Adarsh R; Gloss, Catherine C; Matthews, Jared R L; Huynh, Nguyen P T; Guilak, Farshid

2018-05-30

Cartilage-derived matrix (CDM) has emerged as a promising scaffold material for tissue engineering of cartilage and bone due to its native chondroinductive capacity and its ability to support endochondral ossification. Because it consists of native tissue, CDM can undergo cellular remodeling, which can promote integration with host tissue and enables it to be degraded and replaced by neotissue over time. However, enzymatic degradation of decellularized tissues can occur unpredictably and may not allow sufficient time for mechanically competent tissue to form, especially in the harsh inflammatory environment of a diseased joint. The goal of the current study was to engineer cartilage and bone constructs with the ability to inhibit aberrant inflammatory processes caused by the cytokine interleukin-1 (IL-1), through scaffold-mediated delivery of lentiviral particles containing a doxycycline-inducible IL-1 receptor antagonist (IL-1Ra) transgene on anatomically-shaped CDM constructs. Additionally, scaffold-mediated lentiviral gene delivery was used to facilitate spatial organization of simultaneous chondrogenic and osteogenic differentiation via site-specific transduction of a single mesenchymal stem cell (MSC) population to overexpress either chondrogenic, transforming growth factor-beta 3 (TGF-β3), or osteogenic, bone morphogenetic protein-2 (BMP-2), transgenes. Controlled induction of IL-1Ra expression protected CDM hemispheres from inflammation-mediated degradation, and supported robust bone and cartilage tissue formation even in the presence of IL-1. In the absence of inflammatory stimuli, controlled cellular remodeling was exploited as a mechanism for fusing concentric CDM hemispheres overexpressing BMP-2 and TGF-β3 into a single bi-layered osteochondral construct. Our findings demonstrate that site-specific delivery of inducible and tunable transgenes confers spatial and temporal control over both CDM scaffold remodeling and neotissue composition. Furthermore, these constructs provide a microphysiological in vitro joint organoid model with site-specific, tunable, and inducible protein delivery systems for examining the spatiotemporal response to pro-anabolic and/or inflammatory signaling across the osteochondral interface. Copyright © 2018 Elsevier Ltd. All rights reserved.

High resolution MRI imaging at 9.4 Tesla of the osteochondral unit in a translational model of articular cartilage repair.

PubMed

Goebel, Lars; Müller, Andreas; Bücker, Arno; Madry, Henning

2015-04-16

Non-destructive structural evaluation of the osteochondral unit is challenging. Here, the capability of high-field magnetic resonance imaging (μMRI) at 9.4 Tesla (T) was explored to examine osteochondral repair ex vivo in a preclinical large animal model. A specific aim of this study was to detect recently described alterations of the subchondral bone associated with cartilage repair. Osteochondral samples of medial femoral condyles from adult ewes containing full-thickness articular cartilage defects treated with marrow stimulation were obtained after 6 month in vivo and scanned in a 9.4 T μMRI. Ex vivo imaging of small osteochondral samples (typical volume: 1-2 cm(3)) at μMRI was optimised by variation of repetition time (TR), time echo (TE), flip angle (FA), spatial resolution and number of excitations (NEX) from standard MultiSliceMultiEcho (MSME) and three-dimensional (3D) spoiled GradientEcho (SGE) sequences. A 3D SGE sequence with the parameters: TR = 10 ms, TE = 3 ms, FA = 10°, voxel size = 120 × 120 × 120 μm(3) and NEX = 10 resulted in the best fitting for sample size, image quality, scanning time and artifacts. An isovolumetric voxel shape allowed for multiplanar reconstructions. Within the osteochondral unit articular cartilage, cartilaginous repair tissue and bone marrow could clearly be distinguished from the subchondral bone plate and subarticular spongiosa. Specific alterations of the osteochondral unit associated with cartilage repair such as persistent drill holes, subchondral bone cysts, sclerosis of the subchondral bone plate and of the subarticular spongiosa and intralesional osteophytes were precisely detected. High resolution, non-destructive ex vivo analysis of the entire osteochondral unit in a preclinical large animal model that is sufficient for further analyses is possible using μMRI at 9.4 T. In particular, 9.4 T is capable of accurately depicting alterations of the subchondral bone that are associated with osteochondral repair.

[Design and fabrication of the custom-made titanium condyle by selective laser melting technology].

PubMed

Chen, Jianyu; Luo, Chongdai; Zhang, Chunyu; Zhang, Gong; Qiu, Weiqian; Zhang, Zhiguang

2014-10-01

To design and fabricate the custom-made titanium mandibular condyle by the reverse engineering technology combined with selective laser melting (SLM) technology and to explore the mechanical properties of the SLM-processed samples and the application of the custom-made condyle in the temporomandibular joint (TMJ) reconstruction. The three-dimensional model of the mandibular condyle was obtained from a series of CT databases. The custom-made condyle model was designed by the reverse engineering software. The mandibular condyle was made of titanium powder with a particle size of 20-65 µm as the basic material and the processing was carried out in an argon atmosphere by the SLM machine. The yield strength, ultimate strength, bending strength, hardness, surface morphology and roughness were tested and analyzed. The finite element analysis (FEA) was used to analyze the stress distribution. The complex geometry and the surface of the custom-made condyle can be reproduced precisely by the SLM. The mechanical results showed that the yield strength, ultimate strength, bending strength and hardness were (559±14) MPa, (659±32) MPa, (1 067±42) MPa, and (212±4)HV, respectively. The surface roughness was reduced by sandblast treatment. The custom-made titanium condyle can be fabricated by SLM technology which is time-saving and highly digitized. The mechanical properties of the SLM sample can meet the requirements of surgical implant material in the clinic. The possibility of fabricating custom-made titanium mandibular condyle combined with the FEA opens new interesting perspectives for TMJ reconstruction.

A new building block: costo-osteochondral graft for intra-articular incongruity after distal radius fracture.

PubMed

Tang, Chris Yuk Kwan; Fung, Boris; Poon, T L; Fok, Margaret

2014-01-01

Even with the invention of locking plates, intra-articular fractures of distal radius with extreme comminution remain a challenge for orthopaedic surgeons. Osteochondral graft is a potential choice to reconstruct the articular defect. We report a patient who had a fracture of distal radius with costo-osteochondral graft for articular reconstruction which has not yet been described in the English literature. At nine-year follow-up, he was pain free and had full range of movement of the wrist. The authors suggest that costo-osteochondral graft could be an option with satisfactory result.

Success Rates and Immunologic Responses of Autogenic, Allogenic, and Xenogenic Treatments to Repair Articular Cartilage Defects

PubMed Central

Revell, Christopher M.

2009-01-01

This review examines current approaches available for articular cartilage repair, not only in terms of their regeneration potential, but also as a function of immunologic response. Autogenic repair techniques, including osteochondral plug transplantation, chondrocyte implantation, and microfracture, are the most widely accepted clinical treatment options due to the lack of immunogenic reactions, but only moderate graft success rates have been reported. Although suspended allogenic chondrocytes are shown to evoke an immune response upon implantation, allogenic osteochondral plugs and tissue-engineered grafts using allogenic chondrocytes exhibit a tolerable immunogenic response. Additionally, these repair techniques produce neotissue with success rates approaching those of currently available autogenic repair techniques, while simultaneously obviating their major hindrance of donor tissue scarcity. To date, limited research has been performed with xenogenic tissue, although several studies demonstrate the potential for its long-term success. This article focuses on the various treatment options for cartilage repair and their associated success rates and immunologic responses. PMID:19063664

Improving In Vitro Generated Cartilage-Carrier-Constructs by Optimizing Growth Factor Combination

PubMed Central

Wiegandt, Katharina; Goepfert, Christiane; Pörtner, Ralf

2007-01-01

The presented study is focused on the generation of osteochondral implants for cartilage repair, which consist of bone substitutes covered with in vitro engineered cartilage. Re-differentiation of expanded porcine cells was performed in alginate gel followed by cartilage formation in high-density cell cultures. In this work, different combinations of growth factors for the stimulation of re-differentiation and cartilage formation have been tested to improve the quality of osteochondral implants. It has been demonstrated that supplementation of the medium with growth factors has significant effects on the properties of the matrix. The addition of the growth factors IGF-I (100 ng/mL) and TGF-β1 (10 ng/mL) during the alginate culture and the absence of any growth factors during the high-density cell culture led to significantly higher GAG to DNA ratios and Young’s Moduli of the constructs compared to other combinations. The histological sections showed homogenous tissue and intensive staining for collagen type II. PMID:19662133

An information model to support user-centered design of medical devices.

PubMed

Hagedorn, Thomas J; Krishnamurty, Sundar; Grosse, Ian R

2016-08-01

The process of engineering design requires the product development team to balance the needs and limitations of many stakeholders, including those of the user, regulatory organizations, and the designing institution. This is particularly true in medical device design, where additional consideration must be given for a much more complex user-base that can only be accessed on a limited basis. Given this inherent challenge, few projects exist that consider design domain concepts, such as aspects of a detailed design, a detailed view of various stakeholders and their capabilities, along with the user-needs simultaneously. In this paper, we present a novel information model approach that combines a detailed model of design elements with a model of the design itself, customer requirements, and of the capabilities of the customer themselves. The information model is used to facilitate knowledge capture and automated reasoning across domains with a minimal set of rules by adopting a terminology that treats customer and design specific factors identically, thus enabling straightforward assessments. A uniqueness of this approach is that it systematically provides an integrated perspective on the key usability information that drive design decisions towards more universal or effective outcomes with the very design information impacted by the usability information. This can lead to cost-efficient optimal designs based on a direct inclusion of the needs of customers alongside those of business, marketing, and engineering requirements. Two case studies are presented to show the method's potential as a more effective knowledge management tool with built-in automated inferences that provide design insight, as well as its overall effectiveness as a platform to develop and execute medical device design from a holistic perspective. Copyright © 2016 Elsevier Inc. All rights reserved.

Steady-State Cycle Deck Launcher Developed for Numerical Propulsion System Simulation

NASA Technical Reports Server (NTRS)

VanDrei, Donald E.

1997-01-01

One of the objectives of NASA's High Performance Computing and Communications Program's (HPCCP) Numerical Propulsion System Simulation (NPSS) is to reduce the time and cost of generating aerothermal numerical representations of engines, called customer decks. These customer decks, which are delivered to airframe companies by various U.S. engine companies, numerically characterize an engine's performance as defined by the particular U.S. airframe manufacturer. Until recently, all numerical models were provided with a Fortran-compatible interface in compliance with the Society of Automotive Engineers (SAE) document AS681F, and data communication was performed via a standard, labeled common structure in compliance with AS681F. Recently, the SAE committee began to develop a new standard: AS681G. AS681G addresses multiple language requirements for customer decks along with alternative data communication techniques. Along with the SAE committee, the NPSS Steady-State Cycle Deck project team developed a standard Application Program Interface (API) supported by a graphical user interface. This work will result in Aerospace Recommended Practice 4868 (ARP4868). The Steady-State Cycle Deck work was validated against the Energy Efficient Engine customer deck, which is publicly available. The Energy Efficient Engine wrapper was used not only to validate ARP4868 but also to demonstrate how to wrap an existing customer deck. The graphical user interface for the Steady-State Cycle Deck facilitates the use of the new standard and makes it easier to design and analyze a customer deck. This software was developed following I. Jacobson's Object-Oriented Design methodology and is implemented in C++. The AS681G standard will establish a common generic interface for U.S. engine companies and airframe manufacturers. This will lead to more accurate cycle models, quicker model generation, and faster validation leading to specifications. The standard will facilitate cooperative work between industry and NASA. The NPSS Steady-State Cycle Deck team released a batch version of the Steady-State Cycle Deck in March 1996. Version 1.1 was released in June 1996. During fiscal 1997, NPSS accepted enhancements and modifications to the Steady-State Cycle Deck launcher. Consistent with NPSS' commercialization plan, these modifications will be done by a third party that can provide long-term software support.

Comprehensive analysis of translational osteochondral repair: Focus on the histological assessment.

PubMed

Orth, Patrick; Peifer, Carolin; Goebel, Lars; Cucchiarini, Magali; Madry, Henning

2015-10-01

Articular cartilage guarantees for an optimal functioning of diarthrodial joints by providing a gliding surface for smooth articulation, weight distribution, and shock absorbing while the subchondral bone plays a crucial role in its biomechanical and nutritive support. Both tissues together form the osteochondral unit. The structural assessment of the osteochondral unit is now considered the key standard procedure for evaluating articular cartilage repair in translational animal models. The aim of this review is to give a detailed overview of the different methods for a comprehensive evaluation of osteochondral repair. The main focus is on the histological assessment as the gold standard, together with immunohistochemistry, and polarized light microscopy. Additionally, standards of macroscopic, non-destructive imaging such as high resolution MRI and micro-CT, biochemical, and molecular biological evaluations are addressed. Potential pitfalls of analysis are outlined. A second focus is to suggest recommendations for osteochondral evaluation. Copyright © 2015 Elsevier GmbH. All rights reserved.

Magnetic resonance imaging of hyaline cartilage regeneration in neocartilage graft implantation.

PubMed

Tan, C F; Ng, K K; Ng, S H; Cheung, Y C

2003-12-01

The purpose of this study was to investigate the regenerative potential of hyaline cartilage in a neocartilage graft implant with the aid of MR cartilage imaging using a rabbit model. Surgical osteochondral defects were created in the femoral condyles of 30 mature New Zealand rabbits. The findings of neocartilage in autologous cartilage grafts packed into osteochondral defects were compared with control group of no implant to the osteochondral defect. The outcome of the implantations was correlated with histologic and MR cartilage imaging findings over a 3-month interval. Neocartilage grafts packed into osteochondral defects showed regeneration of hyaline cartilage at the outer layer of the implant using MR cartilage imaging. Fibrosis of fibrocartilage developed at the outer layer of the autologous cartilage graft together with an inflammatory reaction within the osteochondral defect. This animal study provides evidence of the regenerative ability of hyaline cartilage in neocartilage transplants to repair articular cartilage.

Osteochondral Autograft from the Ipsilateral Femoral Head by Surgical Dislocation for Treatment of Femoral Head Fracture Dislocation: A Case Report.

PubMed

Won, Yougun; Lee, Gi Soo; Kim, Sang Bum; Kim, Sun Joong; Yang, Kyu Hyun

2016-11-01

As anatomical reduction of the articular surface of femoral head fractures and restoration of damaged cartilage are essential for good long-term results, many treatment options have been suggested, including fixation of the fracture using various surgical exposures and implants, as well as arthroscopic irrigation and debridement, bone marrow stimulating techniques, osteochondral allograft, autograft, and autogenous chondrocyte implantation. We report a case of osteochondral autograft harvested from its own femoral articular surface through surgical hip dislocation. The osteochondral graft was harvested from the inferior non-weight-bearing articular surface and grafted to the osteochondral defect. One year later, the clinical and radiological results were good, without the collapse of the femoral head or arthritic change. This procedure introduced in our case is considered convenient and able to lessen surgical time without morbidity of the donor site associated with the harvest.

Transition in Gas Turbine Engine Control System Architecture: Modular, Distributed, Embedded

DTIC Science & Technology

2009-08-01

Design + Development + Certification + Procurement + Life Cycle Cost = Net Savings for our Customers Approved for Public Release 16 Economic ...Supporting Small Quantity Electronics Need Broadly Applicable High Temperature Electronics Supply Base Approved for Public Release 17 Economic ...rc ec ures Approved for Public Release 18 Economic Drivers for New FADEC Designs FADEC Implementation Time Pacing Engine Development Issues • FADEC

Hyaline cartilage degenerates after autologous osteochondral transplantation.

PubMed

Tibesku, C O; Szuwart, T; Kleffner, T O; Schlegel, P M; Jahn, U R; Van Aken, H; Fuchs, S

2004-11-01

Autologous osteochondral grafting is a well-established clinical procedure to treat focal cartilage defects in patients, although basic research on this topic remains sparse. The aim of the current study was to evaluate (1) histological changes of transplanted hyaline cartilage of osteochondral grafts and (2) the tissue that connects the transplanted cartilage with the adjacent cartilage in a sheep model. Both knee joints of four sheep were opened surgically and osteochondral grafts were harvested and simultaneously transplanted to the contralateral femoral condyle. The animals were sacrificed after three months and the received knee joints were evaluated histologically. Histological evaluation showed a complete ingrowth of the osseous part of the osteochondral grafts. A healing or ingrowth at the level of the cartilage could not be observed. Histological evaluation of the transplanted grafts according to Mankin revealed significantly more and more severe signs of degeneration than the adjacent cartilage, such as cloning of chondrocytes and irregularities of the articular surface. We found no connecting tissue between the transplanted and the adjacent cartilage and histological signs of degeneration of the transplanted hyaline cartilage. In the light of these findings, long-term results of autologous osteochondral grafts in human beings have to be followed critically.

Human factors involvement in bringing the power of AI to a heterogeneous user population

NASA Technical Reports Server (NTRS)

Czerwinski, Mary; Nguyen, Trung

1994-01-01

The Human Factors involvement in developing COMPAQ QuickSolve, an electronic problem-solving and information system for Compaq's line of networked printers, is described. Empowering customers with expert system technology so they could solve advanced networked printer problems on their own was a major goal in designing this system. This process would minimize customer down-time, reduce the number of phone calls to the Compaq Customer Support Center, improve customer satisfaction, and, most importantly, differentiate Compaq printers in the marketplace by providing the best, and most technologically advanced, customer support. This represents a re-engineering of Compaq's customer support strategy and implementation. In its first generation system, SMART, the objective was to provide expert knowledge to Compaq's help desk operation to more quickly and correctly answer customer questions and problems. QuickSolve is a second generation system in that customer support is put directly in the hands of the consumers. As a result, the design of QuickSolve presented a number of challenging issues. Because the produce would be used by a diverse and heterogeneous set of users, a significant amount of human factors research and analysis was required while designing and implementing the system. Research that shaped the organization and design of the expert system component as well.

Space station System Engineering and Integration (SE and I). Volume 2: Study results

NASA Technical Reports Server (NTRS)

1987-01-01

A summary of significant study results that are products of the Phase B conceptual design task are contained. Major elements are addressed. Study results applicable to each major element or area of design are summarized and included where appropriate. Areas addressed include: system engineering and integration; customer accommodations; test and program verification; product assurance; conceptual design; operations and planning; technical and management information system (TMIS); and advanced development.

Special Gender Studies for Engineering?

ERIC Educational Resources Information Center

Ihsen, Susanne

2005-01-01

Today we are confronted with a new challenge in product development: "Diversity" needs to be implemented in the engineering design and development teams. Such diversity means to "mirror" within the teams the characteristics of different customer groups: the two genders, the different age groups, and the different cultural…

Customized design and 3D printing of face seal for an N95 filtering facepiece respirator.

PubMed

Cai, Mang; Li, Hui; Shen, Shengnan; Wang, Yu; Yang, Quan

2018-03-01

Filtering Facepiece Respirator (FFR) is the most common respirator users in the health care environment utilize for personal protection from outside particles. Comfort and fit are important while wearing an FFR. This paper proposes a novel technology to produce customized face seal design for improving the wearing comfort and fit of FFR wearers. In order to customize the design of face seals, we scanned the faces of three subjects using three-dimensional (3D) laser scanning method. A customized face seal for a 3M 8210 N95 FFR for each headform was designed using reverse engineering technique. Next, the face seal prototypes were fabricated with Acrylonitrile Butadiene Styrene (ABS) plastic using the 3D printing method. A force sensing system based on Arduino Uno R3 was developed, and the force sensor of this system was inserted between the FFR and headform to measure contact pressure. Experimental results showed that the newly designed FFR face seal provided the subjects with an improved contact pressure.

Optimization in the systems engineering process

NASA Technical Reports Server (NTRS)

Lemmerman, Loren A.

1993-01-01

The essential elements of the design process consist of the mission definition phase that provides the system requirements, the conceptual design, the preliminary design and finally the detailed design. Mission definition is performed largely by operations analysts in conjunction with the customer. The result of their study is handed off to the systems engineers for documentation as the systems requirements. The document that provides these requirements is the basis for the further design work of the design engineers at the Lockheed-Georgia Company. The design phase actually begins with conceptual design, which is generally conducted by a small group of engineers using multidisciplinary design programs. Because of the complexity of the design problem, the analyses are relatively simple and generally dependent on parametric analyses of the configuration. The result of this phase is a baseline configuration from which preliminary design may be initiated.

Surgical treatment for osteochondritis dessicans of the knee.

PubMed

Winthrop, Zachary; Pinkowsky, Gregory; Hennrikus, William

2015-12-01

Osteochondritis dissecans (OCD) of the knee is a disease of the subchondral bone with secondary injury to the overlying articular cartilage. OCD lesions are generally categorized as juvenile-growth plates open-or adult-growth plates closed. This maturity-based classification scheme has a prognostic value in that many juvenile OCD lesions will heal with conservative care while most symptomatic adult OCD lesions need surgical intervention. OCD can result in pain, knee joint effusions, loose body formation, and arthritis. Short-term treatment goals include pain and symptom resolution while the long-term goal is to minimize arthritis. Surgical options include debridement, drilling, microfracture, reduction and fixation, autograft osteochondral transplantation, autologous chondrocyte implantation, and allograft osteochondreal transplantation.

Novel alginate biphasic scaffold for osteochondral regeneration: an in vivo evaluation in rabbit and sheep models.

PubMed

Filardo, Giuseppe; Perdisa, Francesco; Gelinsky, Michael; Despang, Florian; Fini, Milena; Marcacci, Maurilio; Parrilli, Anna Paola; Roffi, Alice; Salamanna, Francesca; Sartori, Maria; Schütz, Kathleen; Kon, Elizaveta

2018-05-26

Current therapeutic strategies for osteochondral restoration showed a limited regenerative potential. In fact, to promote the growth of articular cartilage and subchondral bone is a real challenge, due to the different functional and anatomical properties. To this purpose, alginate is a promising biomaterial for a scaffold-based approach, claiming optimal biocompatibility and good chondrogenic potential. A previously developed mineralized alginate scaffold was investigated in terms of the ability to support osteochondral regeneration both in a large and medium size animal model. The results were evaluated macroscopically and by microtomography, histology, histomorphometry, and immunohistochemical analysis. No evidence of adverse or inflammatory reactions was observed in both models, but limited subchondral bone formation was present, together with a slow scaffold resorption time.The implantation of this biphasic alginate scaffold provided partial osteochondral regeneration in the animal model. Further studies are needed to evaluate possible improvement in terms of osteochondral tissue regeneration for this biomaterial.

Osteochondral injuries of the foot and ankle.

PubMed

Frost, Andrew; Roach, Richard

2009-06-01

Osteochondral injuries commonly affect the ankle joint and involve the dome of the talus. This article describes the etiology and pathogenesis of these injuries. Their clinical presentation is described and advice is given on how to diagnose and investigate suspected osteochondral injuries. The various treatment options currently available are briefly reviewed. There is some attempt made to give consensus on optimal treatment of this condition at the present time.

Arthroscopic Surgical Technique for an Acute Talar Dome Osteochondral Lesion in a Professional Rugby League Player.

PubMed

Sullivan, Martin; Fraser, Ethan J; Linklater, James; Harris, Craig; Morgan, Kieran

2017-06-01

Talar osteochondral lesions represent challenging clinical entities, particularly in high-demand athletes. Surgical treatment of large lesions often requires a 2-step procedure, or the use of osteotomy in the case of autologous osteochondral transfer, which can delay return to sport. A professional rugby league player underwent surgery for a complex injury to the ankle. A talar osteochondral lesion with a maximal diameter of 15 mm was treated in an arthroscopic fashion using the cartilage taken from the completely displaced osteochondral fragment. Cartilage was cut into chips and combined with bone graft product containing platelet-derived growth factor and a porous collagen scaffold. Autologous cartilage was then reimplanted arthroscopically. The patient was allowed full ankle motion from 2 weeks postoperatively, and weightbearing was commenced at 6 weeks. Follow-up imaging and functional outcomes, including return to sport, were assessed at regular intervals. The patient was able to return to professional rugby league by 23 weeks postoperatively. Magnetic resonance imaging at 16 months postoperatively showed restoration of the subchondral plate and osseous infill. At final follow-up, the patient remained pain free and was playing at preinjury level. This report describes good outcomes using a novel, 1-step cartilage repair technique to treat a large talar osteochondral lesion in a professional athlete. Level V: Expert opinion.

Domain-specific languages and diagram customization for a concurrent engineering environment

NASA Astrophysics Data System (ADS)

Cole, B.; Dubos, G.; Banazadeh, P.; Reh, J.; Case, K.; Wang, Y.; Jones, S.; Picha, F.

A major open question for advocates of Model-Based Systems Engineering (MBSE) is the question of how system and subsystem engineers will work together. The Systems Modeling Language (SysML), like any language intended for a large audience, is in tension between the desires for simplicity and for expressiveness. In order to be more expressive, many specialized language elements may be introduced, which will unfortunately make a complete understanding of the language a more daunting task. While this may be acceptable for systems modelers, it will increase the challenge of including subsystem engineers in the modeling effort. One possible answer to this situation is the use of Domain-Specific Languages (DSL), which are fully supported by the Unified Modeling Language (UML). SysML is in fact a DSL for systems engineering. The expressive power of a DSL can be enhanced through the use of diagram customization. Various domains have already developed their own schematic vocabularies. Within the space engineering community, two excellent examples are the propulsion and telecommunication subsystems. A return to simple box-and-line diagrams (e.g., the SysML Internal Block Diagram) are in many ways a step backward. In order allow subsystem engineers to contribute directly to the model, it is necessary to make a system modeling tool at least approximate in accessibility to drawing tools like Microsoft PowerPoint and Visio. The challenge is made more extreme in a concurrent engineering environment, where designs must often be drafted in an hour or two. In the case of the Jet Propulsion Laboratory's Team X concurrent design team, a subsystem is specified using a combination of PowerPoint for drawing and Excel for calculation. A pilot has been undertaken in order to meld the drawing portion and the production of master equipment lists (MELs) via a SysML authoring tool, MagicDraw. Team X currently interacts with its customers in a process of sharing presentations. There are severa- inefficiencies that arise from this situation. The first is that a customer team must wait two weeks to a month (which is 2-4 times the duration of most Team X studies themselves) for a finalized, detailed design description. Another is that this information must be re-entered by hand into the set of engineering artifacts and design tools that the mission concept team uses after a study is complete. Further, there is no persistent connection to Team X or institutionally shared formulation design tools and data after a given study, again reducing the direct reuse of designs created in a Team X study. This paper presents the underpinnings of subsystem DSLs as they were developed for this pilot. This includes specialized semantics for different domains as well as the process by which major categories of objects were derived in support of defining the DSLs. The feedback given to us by the domain experts on usability, along with a pilot study with the partial inclusion of these tools is also discussed.

Domain-Specific Languages and Diagram Customization for a Concurrent Engineering Environment

NASA Technical Reports Server (NTRS)

Cole, Bjorn; Dubos, Greg; Banazadeh, Payam; Reh, Jonathan; Case, Kelley; Wang, Yeou-Fang; Jones, Susan; Picha, Frank

2013-01-01

A major open question for advocates of Model-Based Systems Engineering (MBSE) is the question of how system and subsystem engineers will work together. The Systems Modeling Language (SysML), like any language intended for a large audience, is in tension between the desires for simplicity and for expressiveness. In order to be more expressive, many specialized language elements may be introduced, which will unfortunately make a complete understanding of the language a more daunting task. While this may be acceptable for systems modelers, it will increase the challenge of including subsystem engineers in the modeling effort. One possible answer to this situation is the use of Domain-Specific Languages (DSL), which are fully supported by the Unified Modeling Language (UML). SysML is in fact a DSL for systems engineering. The expressive power of a DSL can be enhanced through the use of diagram customization. Various domains have already developed their own schematic vocabularies. Within the space engineering community, two excellent examples are the propulsion and telecommunication subsystems. A return to simple box-and-line diagrams (e.g., the SysML Internal Block Diagram) are in many ways a step backward. In order allow subsystem engineers to contribute directly to the model, it is necessary to make a system modeling tool at least approximate in accessibility to drawing tools like Microsoft PowerPoint and Visio. The challenge is made more extreme in a concurrent engineering environment, where designs must often be drafted in an hour or two. In the case of the Jet Propulsion Laboratory's Team X concurrent design team, a subsystem is specified using a combination of PowerPoint for drawing and Excel for calculation. A pilot has been undertaken in order to meld the drawing portion and the production of master equipment lists (MELs) via a SysML authoring tool, MagicDraw. Team X currently interacts with its customers in a process of sharing presentations. There are several inefficiencies that arise from this situation. The first is that a customer team must wait two weeks to a month (which is 2-4 times the duration of most Team X studies themselves) for a finalized, detailed design description. Another is that this information must be re-entered by hand into the set of engineering artifacts and design tools that the mission concept team uses after a study is complete. Further, there is no persistent connection to Team X or institutionally shared formulation design tools and data after a given study, again reducing the direct reuse of designs created in a Team X study. This paper presents the underpinnings of subsystem DSLs as they were developed for this pilot. This includes specialized semantics for different domains as well as the process by which major categories of objects were derived in support of defining the DSLs. The feedback given to us by the domain experts on usability, along with a pilot study with the partial inclusion of these tools is also discussed.

Imaging of non-osteochondral tissues in osteoarthritis.

PubMed

Guermazi, A; Roemer, F W; Crema, M D; Englund, M; Hayashi, D

2014-10-01

The aim of this review is to describe imaging techniques for evaluation of non-osteochondral structures such as the synovium, menisci in the knee, labrum in the hip, ligaments and muscles and to review the literature from recent clinical and epidemiological studies of OA. This is a non-systematic narrative review of published literature on imaging of non-osteochondral tissues in OA. PubMed and MEDLINE search for articles published up to 2014, using the keywords osteoarthritis, synovitis, meniscus, labrum, ligaments, plica, muscles, magnetic resonance imaging (MRI), ultrasound, computed tomography (CT), scintigraphy, and positron emission tomography (PET). Published literature showed imaging of non-osteochondral tissues in OA relies primarily on MRI and ultrasound. The use of semiquantitative and quantitative imaging biomarkers of non-osteochondral tissues in clinical and epidemiological OA studies is reported. We highlight studies that have compared both imaging methodologies directly, and those that have established a relationship between imaging biomarkers and clinical outcomes. We provide recommendations as to which imaging protocols should be used to assess disease-specific changes regarding synovium, meniscus in the knee, labrum in the hip, and ligaments, and highlight potential pitfalls in their usage. MRI and ultrasound are currently the most useful imaging modalities for evaluation of non-osteochondral tissues in OA. MRI evaluation of any tissue needs to be performed using appropriate MR pulse sequences. Ultrasound may be particularly useful for evaluation of small joints of the hand. Nuclear medicine and CT play a limited role in imaging of non-osteochondral tissues in OA. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Performance optimization of an online retailer by a unique online resilience engineering algorithm

NASA Astrophysics Data System (ADS)

Azadeh, A.; Salehi, V.; Salehi, R.; Hassani, S. M.

2018-03-01

Online shopping has become more attractive and competitive in electronic markets. Resilience engineering (RE) can help such systems divert to the normal state in case of encountering unexpected events. This study presents a unique online resilience engineering (ORE) approach for online shopping systems and customer service performance. Moreover, this study presents a new ORE algorithm for the performance optimisation of an actual online shopping system. The data are collected by standard questionnaires from both expert employees and customers. The problem is then formulated mathematically using data envelopment analysis (DEA). The results show that the design process which is based on ORE is more efficient than the conventional design approach. Moreover, on-time delivery is the most important factor from the personnel's perspective. In addition, according to customers' view, trust, security and good quality assurance are the most effective factors during transactions. This is the first study that introduces ORE for electronic markets. Second, it investigates impact of RE on online shopping through DEA and statistical methods. Third, a practical approach is employed in this study and it may be used for similar online shops. Fourth, the results are verified and validated through complete sensitivity analysis.

Design and Validation of a Compressive Tissue Stimulator with High-Throughput Capacity and Real-Time Modulus Measurement Capability

PubMed Central

Salvetti, David J.; Pino, Christopher J.; Manuel, Steven G.; Dallmeyer, Ian; Rangarajan, Sanjeet V.; Meyer, Tobias; Kotov, Misha

2012-01-01

Mechanical stimulation has been shown to impact the properties of engineered hyaline cartilage constructs and is relevant for engineering of cartilage and osteochondral tissues. Most mechanical stimulators developed to date emphasize precision over adaptability to standard tissue culture equipment and protocols. The realization of mechanical characteristics in engineered constructs approaching native cartilage requires the optimization of complex variables (type of stimulus, regimen, and bimolecular signals). We have proposed and validated a stimulator design that focuses on high construct capacity, compatibility with tissue culture plastic ware, and regimen adaptability to maximize throughput. This design utilizes thin force sensors in lieu of a load cell and a linear encoder to verify position. The implementation of an individual force sensor for each sample enables the measurement of Young's modulus while stimulating the sample. Removable and interchangeable Teflon plungers mounted using neodymium magnets contact each sample. Variations in plunger height and design can vary the strain and force type on individual samples. This allows for the evaluation of a myriad of culture conditions and regimens simultaneously. The system was validated using contact accuracy, and Young's modulus measurements range as key parameters. Contact accuracy for the system was excellent within 1.16% error of the construct height in comparison to measurements made with a micrometer. Biomaterials ranging from bioceramics (cancellous bone, 123 MPa) to soft gels (1% agarose, 20 KPa) can be measured without any modification to the device. The accuracy of measurements in conjunction with the wide range of moduli tested demonstrate the unique characteristics of the device and the feasibility of using this device in mapping real-time changes to Young's modulus of tissue constructs (cartilage, bone) through the developmental phases in ex vivo culture conditions. PMID:21988089

Engineering Changes in Product Design - A Review

NASA Astrophysics Data System (ADS)

Karthik, K.; Janardhan Reddy, K., Dr

2016-09-01

Changes are fundamental to product development. Engineering changes are unavoidable and can arise at any phase of the product life cycle. The consideration of market requirements, customer/user feedbacks, manufacturing constraints, design innovations etc., turning them into viable products can be accomplished when product change is managed properly. In the early design cycle, informal changes are accepted. However, changes become formal when its complexity and cost increases, and as product matures. To maximize the market shares, manufacturers have to effectively and efficiently manage engineering changes by means of Configuration Control. The paper gives a broad overview about ‘Engineering Change Management’ (ECM) through configuration management and its implications in product design. The aim is to give an idea and understanding about the engineering changes in product design scenario to the new researchers. This paper elaborates the significant aspect of managing the engineering changes and the importance of ECM in a product life cycle.

Use of 3D Printing for Custom Wind Tunnel Fabrication

NASA Astrophysics Data System (ADS)

Gagorik, Paul; Bates, Zachary; Issakhanian, Emin

2016-11-01

Small-scale wind tunnels for the most part are fairly simple to produce with standard building equipment. However, the intricate bell housing and inlet shape of an Eiffel type wind tunnel, as well as the transition from diffuser to fan in a rectangular tunnel can present design and construction obstacles. With the help of 3D printing, these shapes can be custom designed in CAD models and printed in the lab at very low cost. The undergraduate team at Loyola Marymount University has built a custom benchtop tunnel for gas turbine film cooling experiments. 3D printing is combined with conventional construction methods to build the tunnel. 3D printing is also used to build the custom tunnel floor and interchangeable experimental pieces for various experimental shapes. This simple and low-cost tunnel is a custom solution for specific engineering experiments for gas turbine technology research.

Osteochondritis Dissecans of the Glenoid in a Major League Baseball Prospect: A Case Report.

PubMed

Grau, Luis Carlos; Jose, Jean; Sama, Andrew Joseph; Baraga, Michael Gerald

2016-01-01

A 16-year-old Major League Baseball prospect presented with persistent shoulder pain associated with throwing. Magnetic resonance imaging (MRI) demonstrated a large osteochondritis dissecans lesion in the posterosuperior aspect of the glenoid. The patient was restricted from throwing and underwent therapy to improve range of motion and throwing mechanics. Eight months after initiating nonoperative treatment, an MRI arthrogram demonstrated a healed lesion. At follow-up 2 years after treatment, full relief of symptoms had persisted. Osteochondritis dissecans lesions of the glenoid are extremely rare, but have the potential to heal in overhead-throwing athletes. To our knowledge, this is the only case reported in the literature that demonstrates a healed osteochondritis dissecans lesion of the glenoid following nonoperative treatment.

Osteochondral Autograft Transplantation Surgery for Metacarpal Head Defects.

PubMed

Kitay, Alison; Waters, Peter M; Bae, Donald S

2016-03-01

Post-traumatic osteonecrosis of the metacarpal head is a challenging problem, particularly in younger patients in whom arthroplasty may not be a durable option. Although several osteochondral reconstructive options have been proposed, some are associated with considerable donor site morbidity and/or require the use of internal fixation. We present an application of osteochondral autograft transplantation surgery as a treatment option for focal metacarpal head lesions. An osteochondral plug from the non-weight-bearing articular surface of the knee is transferred and press-fit to resurface a focal metacarpal head defect. The technical pearls and pitfalls are reviewed, and an illustrative case is presented. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Reinventing the Wheel: Design and Problem Solving

ERIC Educational Resources Information Center

Blasetti, Sean M.

2010-01-01

This article describes a design problem that not only takes students through the technological design process, but it also provides them with real-world problem-solving experience as it relates to the manufacturing and engineering fields. It begins with a scenario placing the student as a custom wheel designer for an automotive manufacturing…

Fresh Osteochondral Allograft Versus Autograft: Twelve-Month Results in Isolated Canine Knee Defects.

PubMed

McCarty, Eric C; Fader, Ryan R; Mitchell, Justin J; Glenn, R Edward; Potter, Hollis G; Spindler, Kurt P

2016-09-01

Osteochondral autografts and allografts have been widely used in the treatment of isolated grade 4 articular cartilage lesions of the knee. However, there is a paucity of literature regarding the basic science investigating the direct comparison between fresh osteochondral allografts to autografts. At 12 months, fresh osteochondral allografts are equal to autografts with respect to function, bony incorporation into host bone, and chondrocyte viability. Controlled laboratory study. Eight adult mongrel dogs underwent bilateral hindlimb osteochondral graft implantation in the knee after creation of an acute Outerbridge grade 4 cartilage defect. One hindlimb of each dog knee received an autograft, and the contralateral knee received an allograft. All dogs were sacrificed at 12 months. Graft analysis included gross examination, radiographs, magnetic resonance imaging (MRI), biomechanical testing, and histology. MRI demonstrated excellent bony incorporation of both autografts and allografts, except for 1 allograft that revealed partial incorporation. Histologic examination of cartilage showed intact hyaline appearance for both autografts and allografts, with fibrocartilage at the host-graft interface of both. Biomechanical testing demonstrated no significant difference between allografts and autografts (P = .76). Furthermore, no significant difference was observed between allografts and the native cartilage with biomechanical testing (P = .84). After 12 months from time of implantation, fresh osteochondral allograft tissue and autograft tissue in this study were not statistically different with respect to biomechanical properties, gross morphology, bony incorporation, or overall histologic characteristics. When compared with the previously reported 6-month incorporation rates, there was improved allograft and autograft incorporation at 12 months. With no significant differences in gross examination, radiographs, MRI, biomechanical testing, or histology in the canine model, the use of allograft tissue to treat osteochondral defects may eliminate the morbidity associated with autograft harvest. © 2016 The Author(s).

Autologous Dual-Tissue Transplantation for Osteochondral Repair

PubMed Central

Foldager, Casper Bindzus; Jensen, Jonas; Lind, Martin

2015-01-01

Background Numerous treatment methods for osteochondral repair have been implemented, including auto- and allogeneic osteochondral transplantations, combined bone and chondrocyte transplantations, and synthetic implants, but no gold standard treatment has been established. We present preliminary data on a combined autologous bone and cartilage chips: autologous dual-tissue transplantation (ADTT); an easily applicable, low-cost treatment option for osteochondral repair. The aim of this study was to investigate the early biological and clinical outcome of ADTT. Materials Eight patients (age 32 ± 7.5 years) suffering from osteochondritis dissecans (OCD) in the knee were enrolled. The OCD lesion was debrided and the osteochondral defect was filled with autologous bone, to a level at the base of the adjacent cartilage. Cartilage biopsies from the intercondylar notch were chipped and embedded within fibrin glue in the defect. Evaluation was performed using magnetic resonance imaging, computed tomography, and clinical scores, preoperative and 1 year postoperative. Results Cartilage tissue repair evaluated using MOCART score improved from 22.5 to 52.5 (P < 0.01). Computed tomography imaging demonstrated very good subchondral bone healing with all 8 patients having a bone filling of >80%. We found improvements 1 year postoperative in the International Knee Documentation Committee score (from 35.9 to 68.1, P < 0.01), Tegner score (from 2.6 to 4.7, P < 0.05), and Knee injury and Osteoarthritis Outcome Score pain, symptoms, sport/recreation and quality of life (P < 0.05). Conclusion Treatment of OCD with ADTT resulted in very good subchondral bone restoration and good cartilage repair. Significant improvements in patient reported outcome was found at 1 year postoperative. This study suggests ADTT as a promising, low-cost, treatment option for osteochondral injuries. PMID:26175862

Refixation of Osteochondral Fractures by an Ultrasound-Activated Pin System - An Ovine In Vivo Examination Using CT and Scanning Electron Microscope.

PubMed

H, Neumann; A P, Schulz; S, Breer; A, Unger; B, Kienast

2015-01-01

Osteochondral injuries, if not treated appropriately, often lead to severe osteoarthritis of the affected joint. Without refixation of the osteochondral fragment, human cartilage only repairs these defects imperfectly. All existing refixation systems for chondral defects have disadvantages, for instance bad MRI quality in the postoperative follow-up or low anchoring forces. To address the problem of reduced stability in resorbable implants, ultrasound-activated pins were developed. By ultrasound-activated melting of the tip of these implants a higher anchoring is assumed. Aim of the study was to investigate, if ultrasound-activated pins can provide a secure refixation of osteochondral fractures comparing to conventional screw and conventional, resorbable pin osteosynthesis. CT scans and scanning electron microscopy should proovegood refixation results with no further tissue damage by the melting of the ultrasound-activated pins in comparison to conventional osteosynthesis. Femoral osteochondral fragments in sheep were refixated with ultrasound-activated pins (SonicPin™), Ethipins(®) and screws (Asnis™). The quality of the refixated fragments was examined after three month of full weight bearing by CT scans and scanning electron microscopy of the cartilage surface. The CT examination found almost no statistically significant difference in the quality of refixation between the three different implants used. Concerning the CT morphology, ultrasound-activated pins demonstrated at least the same quality in refixation of osteochondral fragments as conventional resorbable pins or screws. The scanning electron microscopy showed no major surface damage by the three implants, especially any postulated cartilage damage induced by the heat of the ultrasound-activated pin. The screws protruded above the cartilage surface, which may affect the opposingtibial surface. Using CT scans and scanning electron microscopy, the SonicPin™, the Ethipin(®) and screws were at least equivalent in refixation quality of osteochondral fragments.

Simple geometry tribological study of osteochondral graft implantation in the knee.

PubMed

Bowland, Philippa; Ingham, Eileen; Fisher, John; Jennings, Louise M

2018-03-01

Robust preclinical test methods involving tribological simulations are required to investigate and understand the tribological function of osteochondral repair interventions in natural knee tissues. The aim of this study was to investigate the effects of osteochondral allograft implantation on the local tribology (friction, surface damage, wear and deformation) of the tissues in the natural knee joint using a simple geometry, reciprocating pin-on-plate friction simulator. In addition, the study aimed to assess the ability of osteochondral grafts to restore a low surface damage, deformation and wear articulation when compared to the native state. A method was developed to characterise and quantify surface damage wear and deformation of the opposing cartilage-bone pin surface using a non-contacting optical profiler (Alicona Infinite Focus). Porcine 12 mm diameter cartilage-bone pins were reciprocated against bovine cartilage-bone plates that had 6 mm diameter osteochondral allografts, cartilage defects or stainless steel pins (positive controls) inserted centrally. Increased levels of surface damage with changes in geometry were not associated with significant increases in the coefficient of dynamic friction. Significant damage to the opposing cartilage surface was observed in the positive control groups. Cartilage damage, deformation and wear (as measured by change in geometry) in the xenograft (2.4 mm 3 ) and cartilage defect (0.99 mm 3 ) groups were low and not significantly different (p > 0.05) compared to the negative control in either group. The study demonstrated the potential of osteochondral grafts to restore the congruent articular surface and biphasic tribology of the natural joint. An optical method has been developed to characterise cartilage wear, damage and deformation that can be applied to the tribological assessment of osteochondral grafts in a whole natural knee joint simulation model.

Simple geometry tribological study of osteochondral graft implantation in the knee

PubMed Central

Bowland, Philippa; Ingham, Eileen; Fisher, John; Jennings, Louise M

2018-01-01

Robust preclinical test methods involving tribological simulations are required to investigate and understand the tribological function of osteochondral repair interventions in natural knee tissues. The aim of this study was to investigate the effects of osteochondral allograft implantation on the local tribology (friction, surface damage, wear and deformation) of the tissues in the natural knee joint using a simple geometry, reciprocating pin-on-plate friction simulator. In addition, the study aimed to assess the ability of osteochondral grafts to restore a low surface damage, deformation and wear articulation when compared to the native state. A method was developed to characterise and quantify surface damage wear and deformation of the opposing cartilage-bone pin surface using a non-contacting optical profiler (Alicona Infinite Focus). Porcine 12 mm diameter cartilage-bone pins were reciprocated against bovine cartilage-bone plates that had 6 mm diameter osteochondral allografts, cartilage defects or stainless steel pins (positive controls) inserted centrally. Increased levels of surface damage with changes in geometry were not associated with significant increases in the coefficient of dynamic friction. Significant damage to the opposing cartilage surface was observed in the positive control groups. Cartilage damage, deformation and wear (as measured by change in geometry) in the xenograft (2.4 mm3) and cartilage defect (0.99 mm3) groups were low and not significantly different (p > 0.05) compared to the negative control in either group. The study demonstrated the potential of osteochondral grafts to restore the congruent articular surface and biphasic tribology of the natural joint. An optical method has been developed to characterise cartilage wear, damage and deformation that can be applied to the tribological assessment of osteochondral grafts in a whole natural knee joint simulation model. PMID:29375001

In Vivo Efficacy of Fresh vs. Frozen Osteochondral Allografts in the Goat at 6 Months is Associated with PRG4 Secretion

PubMed Central

Pallante-Kichura, Andrea L.; Chen, Albert C.; Temple-Wong, Michele M.; Bugbee, William D.; Sah, Robert L.

2014-01-01

The long-term efficacy of osteochondral allografts is due to the presence of viable chondrocytes within graft cartilage. Chondrocytes in osteochondral allografts, especially those at the articular surface that normally produce the lubricant proteoglycan-4 (PRG4), are susceptible to storage-associated death. The hypothesis of this study was that the loss of chondrocytes within osteochondral grafts leads to decreased PRG4 secretion, after graft storage and subsequent implant. The objectives were to determine the effect of osteochondral allograft treatment (FROZEN vs. FRESH) on secretion of functional PRG4 after (i) storage, and (ii) 6months in vivo in adult goats. FROZEN allograft storage reduced PRG4 secretion from cartilage by ~85% compared to FRESH allograft storage. After 6months in vivo, the PRG4-secreting function of osteochondral allografts was diminished with prior FROZEN storage by ~81% versus FRESH allografts and by ~84% versus non-operated control cartilage. Concomitantly, cellularity at the articular surface in FROZEN allografts was ~96% lower than FRESH allografts and non-operated cartilage. Thus, the PRG4-secreting function of allografts appears to be maintained in vivo based on its state after storage. PRG4 secretion may be not only a useful marker of allograft performance, but also a biological process protecting the articular surface of grafts following cartilage repair. PMID:23362152

Histological evaluation of calcaneal tuberosity cartilage--A proposed donor site for osteochondral autologous transplant for talar dome osteochondral lesions.

PubMed

Calder, James D F; Ballal, Moez S; Deol, Rupinderbir S; Pearce, Christopher J; Hamilton, Paul; Lutz, Michael

2015-09-01

Osteochondral Autologous Transplant (OATs) as a treatment option for Osteochondral lesions (OCLs) of the talar dome frequently uses the distal femur as the donor site which is associated with donor site morbidity in up to 50%. Some studies have described the presence of hyaline cartilage in the posterior superior calcaneal tuberosity. The aim of this study was to evaluate the posterior superior calcaneal tuberosity to determine if it can be a suitable donor site for OATs of the talus In this cadaveric study, we histologically evaluated 12 osteochondral plugs taken from the posterior superior calcaneal tuberosity and compared them to 12 osteochondral plugs taken from the talar dome. In the talar dome group, all samples had evidence of hyaline cartilage with varying degrees of GAG staining. The average hyaline cartilage thickness in the samples was 1.33 mm. There was no evidence of fibrocartilage, fibrous tissue or fatty tissue in this group. In contrast, the Calcaneal tuberosity samples had no evidence of hyaline cartilage. Fibrocartilage was noted in 3 samples only. We believe that the structural differences between the talus and calcanium grafts render the posterior superior clancaneal tuberosity an unsuitable donor site for OATs in the treatment of OCL of the talus. Copyright © 2014 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

QFD-ANP Approach for the Conceptual Design of Research Vessels: A Case Study

NASA Astrophysics Data System (ADS)

Venkata Subbaiah, Kambagowni; Yeshwanth Sai, Koneru; Suresh, Challa

2016-10-01

Conceptual design is a subset of concept art wherein a new idea of product is created instead of a visual representation which would directly be used in a final product. The purpose is to understand the needs of conceptual design which are being used in engineering designs and to clarify the current conceptual design practice. Quality function deployment (QFD) is a customer oriented design approach for developing new or improved products and services to enhance customer satisfaction. House of quality (HOQ) has been traditionally used as planning tool of QFD which translates customer requirements (CRs) into design requirements (DRs). Factor analysis is carried out in order to reduce the CR portions of HOQ. The analytical hierarchical process is employed to obtain the priority ratings of CR's which are used in constructing HOQ. This paper mainly discusses about the conceptual design of an oceanographic research vessel using analytical network process (ANP) technique. Finally the QFD-ANP integrated methodology helps to establish the importance ratings of DRs.

Implementation of Systems Engineering Practices into a Capstone Course

NASA Technical Reports Server (NTRS)

Murphy, Gloria; Schmidt, Peter

2011-01-01

Discusses the NASA Exploration Systems Mission Directorate senior design projects which are to provide students with senior design project ideas, with potential contribution to NASA ESMD objectives. and provides NASA technical representative to act as external customer / technology mentor / requirements source.

Osteochondritis Dissecans

MedlinePlus

... can then break loose, causing pain and possibly hinder joint motion. Osteochondritis dissecans occurs most often in ... Adolescents participating in organized sports might benefit from education on the risks to their joints associated with ...

OPC model generation procedure for different reticle vendors

NASA Astrophysics Data System (ADS)

Jost, Andrew M.; Belova, Nadya; Callan, Neal P.

2003-12-01

The challenge of delivering acceptable semiconductor products to customers in timely fashion becomes more difficult as design complexity increases. The requirements of current generation designs tax OPC engineers greater than ever before since the readiness of high-quality OPC models can delay new process qualifications or lead to respins, which add to the upward-spiraling costs of new reticle sets, extend time-to-market, and disappoint customers. In their efforts to extend the printability of new designs, OPC engineers generally focus on the data-to-wafer path, ignoring data-to-mask effects almost entirely. However, it is unknown whether reticle makers' disparate processes truly yield comparable reticles, even with identical tools. This approach raises the question of whether a single OPC model is applicable to all reticle vendors. LSI Logic has developed a methodology for quantifying vendor-to-vendor reticle manufacturing differences and adapting OPC models for use at several reticle vendors. This approach allows LSI Logic to easily adapt existing OPC models for use with several reticle vendors and obviates the generation of unnecessary models, allowing OPC engineers to focus their efforts on the most critical layers.

Acute Delamination of Commercially Available Decellularized Osteochondral Allograft Plugs

PubMed Central

Degen, Ryan M.; Tetreault, Danielle; Mahony, Greg T.; Williams, Riley J.

2016-01-01

Articular cartilage injuries, and corresponding surgical procedures, are occurring with increasing frequency as identified by a review of recent surgical trends. Concerns have grown in recent years regarding the longevity of results following microfracture, with a shift toward cartilage restoration procedures in recent years. This case report describes 2 cases of acute failure following the use of commercially available osteochondral allograft plugs used for the treatment of osteochondral defects of the distal femur. In both cases the chondral surface of the plug delaminated from the underlying cancellous bone, resulting in persistent pain and swelling requiring reoperation and removal of the loose fragments. Caution should be employed when considering use of these plugs for the treatment of osteochondral lesions, as similar outcomes have not been noted with other cartilage restoration techniques. PMID:27688840

19 CFR 10.814 - Direct costs of processing operations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... manufacture of the specific good, including fringe benefits, on-the-job training, and the costs of engineering..., design, engineering, and blueprint costs, to the extent that they are allocable to the specific good; (4... 19 Customs Duties 1 2014-04-01 2014-04-01 false Direct costs of processing operations. 10.814...

19 CFR 10.774 - Direct costs of processing operations.

Code of Federal Regulations, 2014 CFR

2014-04-01

... manufacture of the specific good, including fringe benefits, on-the-job training, and the costs of engineering..., design, engineering, and blueprint costs, to the extent that they are allocable to the specific good; (4... 19 Customs Duties 1 2014-04-01 2014-04-01 false Direct costs of processing operations. 10.774...

Osteochondral lesions about the ankle.

PubMed

Naran, Ketan N; Zoga, Adam C

2008-11-01

Osteochondral lesions (OCLs) about the foot and ankle often manifest clinically as prolonged joint pain after trauma, often an ankle sprain, which is refractory to conventional, conservative therapeutic treatment. Noncontrast MR imaging is the standard of care imaging modality for diagnosing and classifying osteochondral lesions, but equivocal or difficult lesions can be assessed more specifically with direct MR arthrography or in conjunction with multidetector CT. Once an OCL has been identified, the imager should make every effort to determine whether it is stable or potentially unstable.

A multilayer biomaterial for osteochondral regeneration shows superiority vs microfractures for the treatment of osteochondral lesions in a multicentre randomized trial at 2 years.

PubMed

Kon, Elizaveta; Filardo, Giuseppe; Brittberg, Mats; Busacca, Maurizio; Condello, Vincenzo; Engebretsen, Lars; Marlovits, Stefan; Niemeyer, Philipp; Platzer, Patrik; Posthumus, Michael; Verdonk, Peter; Verdonk, Renè; Victor, Jan; van der Merwe, Willem; Widuchowski, Wojciech; Zorzi, Claudio; Marcacci, Maurilio

2017-09-14

The increasing awareness on the role of subchondral bone in the etiopathology of articular surface lesions led to the development of osteochondral scaffolds. While safety and promising results have been suggested, there are no trials proving the real potential of the osteochondral regenerative approach. Aim was to assess the benefit provided by a nanostructured collagen-hydroxyapatite (coll-HA) multilayer scaffold for the treatment of chondral and osteochondral knee lesions. In this multicentre randomized controlled clinical trial, 100 patients affected by symptomatic chondral and osteochondral lesions were treated and evaluated for up to 2 years (51 study group and 49 control group). A biomimetic coll-HA scaffold was studied, and bone marrow stimulation (BMS) was used as reference intervention. Primary efficacy measurement was IKDC subjective score at 2 years. Secondary efficacy measurements were: KOOS, IKDC Knee Examination Form, Tegner and VAS Pain scores evaluated at 6, 12 and 24 months. Tissue regeneration was evaluated with MRI MOCART scoring system at 6, 12 and 24 months. An external independent agency was involved to ensure data correctness and objectiveness. A statistically significant improvement of all clinical scores was obtained from basal evaluation to 2-year follow-up in both groups, although no overall statistically significant differences were detected between the two treatments. Conversely, the subgroup of patients affected by deep osteochondral lesions (i.e. Outerbridge grade IV and OCD) showed a statistically significant better IKDC subjective outcome (+12.4 points, p = 0.036) in the coll-HA group. Statistically significant better results were also found for another challenging group: sport active patients (+16.0, p = 0.027). Severe adverse events related to treatment were documented only in three patients in the coll-HA group and in one in the BMS group. The MOCART score showed no statistical difference between the two groups. This study highlighted the safety and potential of a biomimetic implant. While no statistically significant differences were found compared to BMS for chondral lesions, this procedure can be considered a suitable option for the treatment of osteochondral lesions. I.

Employment Opportunities for the Handicapped in Programmable Automation.

ERIC Educational Resources Information Center

Swift, Richard; Leneway, Robert

A Computer Integrated Manufacturing System may make it possible for severely disabled people to custom design, machine, and manufacture either wood or metal parts. Programmable automation merges computer aided design, computer aided manufacturing, computer aided engineering, and computer integrated manufacturing systems with automated production…

Comparison of the stability of various internal fixators used in the treatment of osteochondritis dissecans--a mechanical model.

PubMed

Morelli, Moreno; Poitras, Philippe; Grimes, Valentine; Backman, David; Dervin, Geoffrey

2007-04-01

The purpose of this study was to determine what characteristics of fixation devices used in the treatment of osteochondritis dissecans (OCD) contribute to improved stability to resist shear loading. An OCD model was designed using rigid polyurethane foam. Each specimen consisted of two components, an osteochondral fragment and a corresponding defect. A total of 40 specimens were prepared and assigned to one of four groups: control (no extrinsic stabilizer); two 2-mm-diameter Kirschner wires (K-wires), 40 mm in length; one threaded washer and a 28-mm screw; and one threaded washer and a 38 mm screw. Each specimen was mounted onto an Iosipescu shear test fixture and subjected to shear loads at a pseudo-static displacement rate of 0.075 mm/s. All groups demonstrated some stability; controls were significantly less stable than all other groups. The group with the threaded washer and 38-mm screw demonstrated the greatest stability (p < 0.001), and no difference was noted between the K-wire and 28-mm screw groups. These results suggest that, in this OCD model, friction conferred some intrinsic stability to resist loads in shear. However, stability was improved with the use of long implants that compressed the fragments together.

76 FR 21775 - Notice of Issuance of Final Determination Concerning Certain Office Workstations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-18

.... Sec. 134.1(b)), defines ``country of origin'' as: [T]he country of manufacture, production, or growth... engineered and designed the office workstations wholly within the U.S. The assembly and installation of the... customer to design a workstation architecture best suited to the specific office space. Once a design...

A Case Study of Reverse Engineering Integrated in an Automated Design Process

NASA Astrophysics Data System (ADS)

Pescaru, R.; Kyratsis, P.; Oancea, G.

2016-11-01

This paper presents a design methodology which automates the generation of curves extracted from the point clouds that have been obtained by digitizing the physical objects. The methodology is described on a product belonging to the industry of consumables, respectively a footwear type product that has a complex shape with many curves. The final result is the automated generation of wrapping curves, surfaces and solids according to the characteristics of the customer's foot, and to the preferences for the chosen model, which leads to the development of customized products.

Development of a user customizable imaging informatics-based intelligent workflow engine system to enhance rehabilitation clinical trials

NASA Astrophysics Data System (ADS)

Wang, Ximing; Martinez, Clarisa; Wang, Jing; Liu, Ye; Liu, Brent

2014-03-01

Clinical trials usually have a demand to collect, track and analyze multimedia data according to the workflow. Currently, the clinical trial data management requirements are normally addressed with custom-built systems. Challenges occur in the workflow design within different trials. The traditional pre-defined custom-built system is usually limited to a specific clinical trial and normally requires time-consuming and resource-intensive software development. To provide a solution, we present a user customizable imaging informatics-based intelligent workflow engine system for managing stroke rehabilitation clinical trials with intelligent workflow. The intelligent workflow engine provides flexibility in building and tailoring the workflow in various stages of clinical trials. By providing a solution to tailor and automate the workflow, the system will save time and reduce errors for clinical trials. Although our system is designed for clinical trials for rehabilitation, it may be extended to other imaging based clinical trials as well.

Fully printable, strain-engineered electronic wrap for customizable soft electronics.

PubMed

Byun, Junghwan; Lee, Byeongmoon; Oh, Eunho; Kim, Hyunjong; Kim, Sangwoo; Lee, Seunghwan; Hong, Yongtaek

2017-03-24

Rapid growth of stretchable electronics stimulates broad uses in multidisciplinary fields as well as industrial applications. However, existing technologies are unsuitable for implementing versatile applications involving adaptable system design and functions in a cost/time-effective way because of vacuum-conditioned, lithographically-predefined processes. Here, we present a methodology for a fully printable, strain-engineered electronic wrap as a universal strategy which makes it more feasible to implement various stretchable electronic systems with customizable layouts and functions. The key aspects involve inkjet-printed rigid island (PRI)-based stretchable platform technology and corresponding printing-based automated electronic functionalization methodology, the combination of which provides fully printed, customized layouts of stretchable electronic systems with simplified process. Specifically, well-controlled contact line pinning effect of printed polymer solution enables the formation of PRIs with tunable thickness; and surface strain analysis on those PRIs leads to the optimized stability and device-to-island fill factor of strain-engineered electronic wraps. Moreover, core techniques of image-based automated pinpointing, surface-mountable device based electronic functionalizing, and one-step interconnection networking of PRIs enable customized circuit design and adaptable functionalities. To exhibit the universality of our approach, multiple types of practical applications ranging from self-computable digital logics to display and sensor system are demonstrated on skin in a customized form.

Advanced engineering tools for design and fabrication of a custom nasal prosthesis

NASA Astrophysics Data System (ADS)

Oliveira, Inês; Leal, Nuno; Silva, Pedro; da Costa Ferreira, A.; Neto, Rui J.; Lino, F. Jorge; Reis, Ana

2012-09-01

Unexpected external defects resulting from neoplasms, burns, congenital malformations, trauma or other diseases, particularly when involving partial or total loss of an external organ, can be emotionally devastating. These defects can be restored with prosthesis, obtained by different techniques, materials and methods. The increase of patient numbers and cost constraints lead to the need of exploring new techniques that can increase efficiency. The main goal of this project was to develop a full engineering-based manufacturing process to obtain soft-tissue prosthesis that could provide faster and less expensive options in the manufacturing of customized prosthesis, and at the same time being able to reproduce the highest degree of details, with the maximum comfort for the patient. Design/methodology/approach - This case report describes treatment using silicone prosthesis with an anatomic retention for an 80-years-old woman with a rhinectomy. The proposed methodology integrates non-contact structured light scanning, CT and reverse engineering with CAD/CAM and additive manufacturing technology. Findings - The proposed protocol showed encouraging results since reveals being a better solution for fabricating custom-made facial prostheses for asymmetrical organs than conventional approaches. The process allows the attainment of prosthesis with the minimum contact and discomfort for the patient, disclosing excellent results in terms of aesthetic, prosthesis retention and in terms of time and resources consumed.

Fully printable, strain-engineered electronic wrap for customizable soft electronics

NASA Astrophysics Data System (ADS)

Byun, Junghwan; Lee, Byeongmoon; Oh, Eunho; Kim, Hyunjong; Kim, Sangwoo; Lee, Seunghwan; Hong, Yongtaek

2017-03-01

Rapid growth of stretchable electronics stimulates broad uses in multidisciplinary fields as well as industrial applications. However, existing technologies are unsuitable for implementing versatile applications involving adaptable system design and functions in a cost/time-effective way because of vacuum-conditioned, lithographically-predefined processes. Here, we present a methodology for a fully printable, strain-engineered electronic wrap as a universal strategy which makes it more feasible to implement various stretchable electronic systems with customizable layouts and functions. The key aspects involve inkjet-printed rigid island (PRI)-based stretchable platform technology and corresponding printing-based automated electronic functionalization methodology, the combination of which provides fully printed, customized layouts of stretchable electronic systems with simplified process. Specifically, well-controlled contact line pinning effect of printed polymer solution enables the formation of PRIs with tunable thickness; and surface strain analysis on those PRIs leads to the optimized stability and device-to-island fill factor of strain-engineered electronic wraps. Moreover, core techniques of image-based automated pinpointing, surface-mountable device based electronic functionalizing, and one-step interconnection networking of PRIs enable customized circuit design and adaptable functionalities. To exhibit the universality of our approach, multiple types of practical applications ranging from self-computable digital logics to display and sensor system are demonstrated on skin in a customized form.

Fully printable, strain-engineered electronic wrap for customizable soft electronics

PubMed Central

Byun, Junghwan; Lee, Byeongmoon; Oh, Eunho; Kim, Hyunjong; Kim, Sangwoo; Lee, Seunghwan; Hong, Yongtaek

2017-01-01

Rapid growth of stretchable electronics stimulates broad uses in multidisciplinary fields as well as industrial applications. However, existing technologies are unsuitable for implementing versatile applications involving adaptable system design and functions in a cost/time-effective way because of vacuum-conditioned, lithographically-predefined processes. Here, we present a methodology for a fully printable, strain-engineered electronic wrap as a universal strategy which makes it more feasible to implement various stretchable electronic systems with customizable layouts and functions. The key aspects involve inkjet-printed rigid island (PRI)-based stretchable platform technology and corresponding printing-based automated electronic functionalization methodology, the combination of which provides fully printed, customized layouts of stretchable electronic systems with simplified process. Specifically, well-controlled contact line pinning effect of printed polymer solution enables the formation of PRIs with tunable thickness; and surface strain analysis on those PRIs leads to the optimized stability and device-to-island fill factor of strain-engineered electronic wraps. Moreover, core techniques of image-based automated pinpointing, surface-mountable device based electronic functionalizing, and one-step interconnection networking of PRIs enable customized circuit design and adaptable functionalities. To exhibit the universality of our approach, multiple types of practical applications ranging from self-computable digital logics to display and sensor system are demonstrated on skin in a customized form. PMID:28338055

Editorial Commentary: The Acellular Osteochondral Allograft, the Emperor Has New Clothes.

PubMed

Mandelbaum, Bert R; Chahla, Jorge

2017-12-01

For larger lesions (>2.5-cm 2 ), clinical evidence and practice have shown that fresh osteochondral allograft have good durability, with 88% return to sport and greater than 75% 10-year survival rates for treatment of large femoral condyle lesions. That said, the use of fresh osteochondral allografts in clinical practice is limited by the availability of acceptable donor tissues for eligible patients in a timely fashion. Significant diminution of chondrocyte viability and density occurs during the preservation and storage period. All osteochondral allografts are not equal in performance and outcome. Chondrocyte density and viability are critical for successful transplantation and outcome in the short and long term. This commentary highlights the high failure rates of tissue when it is acellular. Copyright © 2017 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

26 CFR 1.460-1 - Long-term contracts.

Code of Federal Regulations, 2011 CFR

2011-04-01

... attributable to designing the satellite and developing computer software using the PCM. Example 7. Non-long... customer has title to, control over, or bears the risk of loss from, the property manufactured or... as design and engineering costs, other than expenses attributable to bidding and negotiating...

26 CFR 1.460-1 - Long-term contracts.

Code of Federal Regulations, 2012 CFR

2012-04-01

... attributable to designing the satellite and developing computer software using the PCM. Example 7. Non-long... customer has title to, control over, or bears the risk of loss from, the property manufactured or... as design and engineering costs, other than expenses attributable to bidding and negotiating...

26 CFR 1.460-1 - Long-term contracts.

Code of Federal Regulations, 2014 CFR

2014-04-01

... attributable to designing the satellite and developing computer software using the PCM. Example 7. Non-long... customer has title to, control over, or bears the risk of loss from, the property manufactured or... as design and engineering costs, other than expenses attributable to bidding and negotiating...

26 CFR 1.460-1 - Long-term contracts.

Code of Federal Regulations, 2013 CFR

2013-04-01

... attributable to designing the satellite and developing computer software using the PCM. Example 7. Non-long... customer has title to, control over, or bears the risk of loss from, the property manufactured or... as design and engineering costs, other than expenses attributable to bidding and negotiating...

Here's the beef: A case study in organizational transformation

NASA Technical Reports Server (NTRS)

Huseonica, William F.; Giardino, Marco J.

1992-01-01

The Science and Technology Lab (STL) is tasked with the design, development, and application of the science and engineering services. Formed in the early 1970's STL adhered to many traditional attitudes including barriers to communication, excessive management control, parochial strategies, unclear measures of success, lack of customer focus, underutilization of people, and excessive administrative burdens on scientists and engineers. The challenge for the STL was to maximize customer satisfaction through the effective and efficient application of the notable skills and talents of the STL's workforce. In this way, the Lab would begin its exciting journey toward becoming world class. A discussion of this on-going transformation is presented.

Customer Management Skills for Effective Air Force Civil Engineering Customer Service.

DTIC Science & Technology

1986-09-01

advertise --competence. (1) Craftsmen working closely with customer service -doing what is promised when it’s promised -if return to job site required, tell...RD-RI74 1 4 CUSTOMER MANAGEMENT SKILLS FOR EFFECTIVE AIR FORCE / I CIVIL ENGINEERING CUST (U) AIR FORCE INST OF TECH WRIGHT-PATTERSON RFS ON...I93 -A CUSTOMER MANAGEMENT SKILLS FOR EFFECTIVE AIR FORCE CIVIL ENGINEERING CUSTOMER SERVICE THESIS Danny S.- Long Captain, USAF AFIT/GEM/DEM/86S-1 7

How I Manage Osteochondritis Dissecans.

ERIC Educational Resources Information Center

DiStefano, Vincent J.

1986-01-01

Osteochondritis dissecans, a lesion found most often on the femur at the knee joint, occurs most frequently in active adolescents. This article describes treatment for preadolescents, adolescents, and adults. Osteochondritus dissecans of the patella is also presented. (MT)

A systematic approach to the Kansei factors of tactile sense regarding the surface roughness.

PubMed

Choi, Kyungmee; Jun, Changrim

2007-01-01

Designing products to satisfy customers' emotion requires the information gathered through the human senses, which are visual, auditory, olfactory, gustatory, or tactile senses. By controlling certain design factors, customers' emotion can be evaluated, designed, and satisfied. In this study, a systematic approach is proposed to study the tactile sense regarding the surface roughness. Numerous pairs of antonymous tactile adjectives are collected and clustered. The optimal number of adjective clusters is estimated based on the several criterion functions. The representative average preferences of the final clusters are obtained as the estimates of engineering parameters to control the surface roughness of the commercial polymer-based products.

Recent Advances in Cartilage Tissue Engineering: From the Choice of Cell Sources to the Use of Bioreactors

NASA Astrophysics Data System (ADS)

Martin, Ivan; Démarteau, Olivier; Braccini, Alessandra

Grafting engineered cartilage tissues represents a promising approach for the repair of joint injuries. Recent animal experiments have demonstrated that tissues engineered by culturing chondrocytes on 3D scaffolds in bioreactors provide functional templates for orderly repair of large osteochondral lesions. To date, however, a reproducible generation of uniform cartilage tissues of predefined size starting from adult human cells has not been achieved. In this paper we review some of the recent advances and challenges ahead in the identification of appropriate (i) cell sources, (ii) bioactive factors, (iii) 3D scaffolds and (iv) bioreactors for human cartilage tissue engineering. We also present an example of how integrated efforts in these different areas can help addressing fundamental questions and advancing the field of cartilage tissue engineering towards clinical use. The presented experiment demonstrates that human nasal chondrocytes are responsive to dynamic loading and thus could be further investigated as a cell source for implantation in a joint environment.

Integrating Thermal Tools Into the Mechanical Design Process

NASA Technical Reports Server (NTRS)

Tsuyuki, Glenn T.; Siebes, Georg; Novak, Keith S.; Kinsella, Gary M.

1999-01-01

The intent of mechanical design is to deliver a hardware product that meets or exceeds customer expectations, while reducing cycle time and cost. To this end, an integrated mechanical design process enables the idea of parallel development (concurrent engineering). This represents a shift from the traditional mechanical design process. With such a concurrent process, there are significant issues that have to be identified and addressed before re-engineering the mechanical design process to facilitate concurrent engineering. These issues also assist in the integration and re-engineering of the thermal design sub-process since it resides within the entire mechanical design process. With these issues in mind, a thermal design sub-process can be re-defined in a manner that has a higher probability of acceptance, thus enabling an integrated mechanical design process. However, the actual implementation is not always problem-free. Experience in applying the thermal design sub-process to actual situations provides the evidence for improvement, but more importantly, for judging the viability and feasibility of the sub-process.

Engineering synthetic TALE and CRISPR/Cas9 transcription factors for regulating gene expression.

PubMed

Kabadi, Ami M; Gersbach, Charles A

2014-09-01

Engineered DNA-binding proteins that can be targeted to specific sites in the genome to manipulate gene expression have enabled many advances in biomedical research. This includes generating tools to study fundamental aspects of gene regulation and the development of a new class of gene therapies that alter the expression of endogenous genes. Designed transcription factors have entered clinical trials for the treatment of human diseases and others are in preclinical development. High-throughput and user-friendly platforms for designing synthetic DNA-binding proteins present innovative methods for deciphering cell biology and designing custom synthetic gene circuits. We review two platforms for designing synthetic transcription factors for manipulating gene expression: Transcription activator-like effectors (TALEs) and the RNA-guided clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. We present an overview of each technology and a guide for designing and assembling custom TALE- and CRISPR/Cas9-based transcription factors. We also discuss characteristics of each platform that are best suited for different applications. Copyright © 2014 Elsevier Inc. All rights reserved.

Differences in joint morphology between the knee and ankle affect the repair of osteochondral defects in a rabbit model.

PubMed

Makitsubo, Manami; Adachi, Nobuo; Nakasa, Tomoyuki; Kato, Tomohiro; Shimizu, Ryo; Ochi, Mitsuo

2016-10-04

Although differences in the results of the bone marrow stimulation technique between the knee and ankle have been reported, a detailed mechanism for those differences has not been clarified. The purpose of this study was to examine whether morphological differences between the knee and ankle joint affect the results of drilling as treatment for osteochondral defects in a rabbit model. Osteochondral defects were created at the knee and ankle joint in the rabbit. In the knee, osteochondral defects were created at the medial femoral condyle (MFC) and patellar groove (PG). At the ankle, defects were created in the talus at either a covered or uncovered area by the tibial plafond. After creating the osteochondral defect, drilling was performed. At 4, 8, and 12 weeks after surgery, repair of the osteochondral defects were evaluated histologically. The proliferation of rabbit chondrocytes and proteoglycan release of cartilage tissue in response to IL-1β were analyzed in vitro in both joints. At 8 weeks after surgery, hyaline cartilage repair was observed in defects at the covered area of the talus and the MFC. At 12 weeks, hyaline cartilage with a normal thickness was observed for the defect at the covered area of the talus, but not for the defect at the MFC. At 12 weeks, subchondral bone formation progressed and a normal contour of subchondral bone was observed on CT in the defect at the covered area of the talus. No significant differences in chondrocyte proliferation rate and proteoglycan release were detected between the knee and ankle in vitro. Our results demonstrate that the covered areas of the talus show early and sufficient osteochondral repair compared to that of the knee and the uncovered areas of the talus. These results suggest that the congruent joint shows better subchondral repair prior to cartilage repair compared to that of the incongruent joint.

Refixation of Osteochondral Fractures by an Ultrasound-Activated Pin System – An Ovine In Vivo Examination Using CT and Scanning Electron Microscope

PubMed Central

H, Neumann; A.P, Schulz; S, Breer; A, Unger; B, Kienast

2015-01-01

Background: Osteochondral injuries, if not treated appropriately, often lead to severe osteoarthritis of the affected joint. Without refixation of the osteochondral fragment, human cartilage only repairs these defects imperfectly. All existing refixation systems for chondral defects have disadvantages, for instance bad MRI quality in the postoperative follow-up or low anchoring forces. To address the problem of reduced stability in resorbable implants, ultrasound-activated pins were developed. By ultrasound-activated melting of the tip of these implants a higher anchoring is assumed. Aim of the study was to investigate, if ultrasound-activated pins can provide a secure refixation of osteochondral fractures comparing to conventional screw and conventional, resorbable pin osteosynthesis. CT scans and scanning electron microscopy should proovegood refixation results with no further tissue damage by the melting of the ultrasound-activated pins in comparison to conventional osteosynthesis. Methods: Femoral osteochondral fragments in sheep were refixated with ultrasound-activated pins (SonicPin™), Ethipins® and screws (Asnis™). The quality of the refixated fragments was examined after three month of full weight bearing by CT scans and scanning electron microscopy of the cartilage surface. Results: The CT examination found almost no statistically significant difference in the quality of refixation between the three different implants used. Concerning the CT morphology, ultrasound-activated pins demonstrated at least the same quality in refixation of osteochondral fragments as conventional resorbable pins or screws. The scanning electron microscopy showed no major surface damage by the three implants, especially any postulated cartilage damage induced by the heat of the ultrasound-activated pin. The screws protruded above the cartilage surface, which may affect the opposingtibial surface. Conclusion: Using CT scans and scanning electron microscopy, the SonicPin™, the Ethipin® and screws were at least equivalent in refixation quality of osteochondral fragments. PMID:25674184

Genetics Home Reference: familial osteochondritis dissecans

MedlinePlus

... Familial osteochondritis dissecans Seattle Children's TeensHealth from Nemours: Knee Injuries University of Connecticut Health Center Patient Support and Advocacy Resources (1 link) American College of Rheumatology: Osteoarthritis ClinicalTrials.gov (1 link) ClinicalTrials.gov Scientific Articles ...

Technical Report: Correlation Between the Repair of Cartilage and Subchondral Bone in an Osteochondral Defect Using Bilayered, Biodegradable Hydrogel Composites.

PubMed

Lu, Steven; Lam, Johnny; Trachtenberg, Jordan E; Lee, Esther J; Seyednejad, Hajar; van den Beucken, Jeroen J J P; Tabata, Yasuhiko; Kasper, F Kurtis; Scott, David W; Wong, Mark E; Jansen, John A; Mikos, Antonios G

2015-12-01

The present work investigated correlations between cartilage and subchondral bone repair, facilitated by a growth factor-delivering scaffold, in a rabbit osteochondral defect model. Histological scoring indices and microcomputed tomography morphological parameters were used to evaluate cartilage and bone repair, respectively, at 6 and 12 weeks. Correlation analysis revealed significant associations between specific cartilage indices and subchondral bone parameters that varied with location in the defect (cortical vs. trabecular region), time point (6 vs. 12 weeks), and experimental group (insulin-like growth factor-1 only, bone morphogenetic protein-2 only, or both growth factors). In particular, significant correlations consistently existed between cartilage surface regularity and bone quantity parameters. Overall, correlation analysis between cartilage and bone repair provided a fuller understanding of osteochondral repair and can help drive informed studies for future osteochondral regeneration strategies.

Chemical and morphological gradient scaffolds to mimic hierarchically complex tissues: From theoretical modeling to their fabrication.

PubMed

Marrella, Alessandra; Aiello, Maurizio; Quarto, Rodolfo; Scaglione, Silvia

2016-10-01

Porous multiphase scaffolds have been proposed in different tissue engineering applications because of their potential to artificially recreate the heterogeneous structure of hierarchically complex tissues. Recently, graded scaffolds have been also realized, offering a continuum at the interface among different phases for an enhanced structural stability of the scaffold. However, their internal architecture is often obtained empirically and the architectural parameters rarely predetermined. The aim of this work is to offer a theoretical model as tool for the design and fabrication of functional and structural complex graded scaffolds with predicted morphological and chemical features, to overcome the time-consuming trial and error experimental method. This developed mathematical model uses laws of motions, Stokes equations, and viscosity laws to describe the dependence between centrifugation speed and fiber/particles sedimentation velocity over time, which finally affects the fiber packing, and thus the total porosity of the 3D scaffolds. The efficacy of the theoretical model was tested by realizing engineered graded grafts for osteochondral tissue engineering applications. The procedure, based on combined centrifugation and freeze-drying technique, was applied on both polycaprolactone (PCL) and collagen-type-I (COL) to test the versatility of the entire process. A functional gradient was combined to the morphological one by adding hydroxyapatite (HA) powders, to mimic the bone mineral phase. Results show that 3D bioactive morphologically and chemically graded grafts can be properly designed and realized in agreement with the theoretical model. Biotechnol. Bioeng. 2016;113: 2286-2297. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A unique nuclear thermal rocket engine using a particle bed reactor

NASA Astrophysics Data System (ADS)

Culver, Donald W.; Dahl, Wayne B.; McIlwain, Melvin C.

1992-01-01

Aerojet Propulsion Division (APD) studied 75-klb thrust Nuclear Thermal Rocket Engines (NTRE) with particle bed reactors (PBR) for application to NASA's manned Mars mission and prepared a conceptual design description of a unique engine that best satisfied mission-defined propulsion requirements and customer criteria. This paper describes the selection of a sprint-type Mars transfer mission and its impact on propulsion system design and operation. It shows how our NTRE concept was developed from this information. The resulting, unusual engine design is short, lightweight, and capable of high specific impulse operation, all factors that decrease Earth to orbit launch costs. Many unusual features of the NTRE are discussed, including nozzle area ratio variation and nozzle closure for closed loop after cooling. Mission performance calculations reveal that other well known engine options do not support this mission.

Spark innovation through empathic design.

PubMed

Leonard, D; Rayport, J F

1997-01-01

Companies are used to bringing in customers to participate in focus groups, usability laboratories, and market research surveys in order to help in the development of new products and services. And for improving products that customers know well, those tools are highly sophisticated. For example, knowledgeable customers are adept at identifying the specific scent of leather they expect in a luxury vehicle or at helping to tune the sound of a motorcycle engine to just the timbre that evokes feelings of power. But to go beyond improvements to the familiar, companies need to identify and meet needs that customers may not yet recognize. To accomplish that task, a set of techniques called empathic design can help. Rather than bring the customers to the company, empathic design calls for company representatives to watch customers using products and services in the context of their own environments. By doing so, managers can often identify unexpected uses for their products, just as the product manager of a cooking oil did when he observed a neighbor spraying the oil on the blades of a lawn mower to reduce grass buildup. They can also uncover problems that customers don't mention in surveys, as the president of Nissan Design did when he watched a couple struggling to remove the backseat of a competitor's minivan in order to transport a couch. The five-step process Dorothy Leonard and Jeffrey Rayport describe in detail is a relatively low-cost, low-risk way to identify customer needs, and it has the potential to redirect a company's existing technological capabilities toward entirely new businesses.

Greater magnitude tibiofemoral contact forces are associated with reduced prevalence of osteochondral pathologies 2-3 years following anterior cruciate ligament reconstruction.

PubMed

Saxby, David John; Bryant, Adam L; Van Ginckel, Ans; Wang, Yuanyuan; Wang, Xinyang; Modenese, Luca; Gerus, Pauline; Konrath, Jason M; Fortin, Karine; Wrigley, Tim V; Bennell, Kim L; Cicuttini, Flavia M; Vertullo, Christopher; Feller, Julian A; Whitehead, Tim; Gallie, Price; Lloyd, David G

2018-06-07

External loading of osteoarthritic and healthy knees correlates with current and future osteochondral tissue state. These relationships have not been examined following anterior cruciate ligament reconstruction. We hypothesised greater magnitude tibiofemoral contact forces were related to increased prevalence of osteochondral pathologies, and these relationships were exacerbated by concomitant meniscal injury. This was a cross-sectional study of 100 individuals (29.7 ± 6.5 years, 78.1 ± 14.4 kg) examined 2-3 years following hamstring tendon anterior cruciate ligament reconstruction. Thirty-eight participants had concurrent meniscal pathology (30.6 ± 6.6 years, 83.3 ± 14.3 kg), which included treated and untreated meniscal injury, and 62 participants (29.8 ± 6.4 years, 74.9 ± 13.3 kg) were free of meniscal pathology. Magnetic resonance imaging of reconstructed knees was used to assess prevalence of tibiofemoral osteochondral pathologies (i.e., cartilage defects and bone marrow lesions). A calibrated electromyogram-driven neuromusculoskeletal model was used to predict medial and lateral tibiofemoral compartment contact forces from gait analysis data. Relationships between contact forces and osteochondral pathology prevalence were assessed using logistic regression models. In patients with reconstructed knees free from meniscal pathology, greater medial contact forces were related to reduced prevalence of medial cartilage defects (odds ratio (OR) = 0.7, Wald χ 2 (2) = 7.9, 95% confidence interval (CI) = 0.50-95, p = 0.02) and medial bone marrow lesions (OR = 0.8, Wald χ 2 (2) = 4.2, 95% CI = 0.7-0.99, p = 0.04). No significant relationships were found in lateral compartments. In reconstructed knees with concurrent meniscal pathology, no relationships were found between contact forces and osteochondral pathologies. In patients with reconstructed knees free from meniscal pathology, increased contact forces were associated with fewer cartilage defects and bone marrow lesions in medial, but not, lateral tibiofemoral compartments. No significant relationships were found between contact forces and osteochondral pathologies in reconstructed knees with meniscal pathology for any tibiofemoral compartment. Future studies should focus on determining longitudinal effects of contact forces and changes in osteochondral pathologies. IV.

[Arthroscopic treatment of chondral lesions of the ankle joint. Evidence-based therapy].

PubMed

Thomas, M; Jordan, M; Hamborg-Petersen, E

2016-02-01

Ankle sprains are the most relevant injuries of the lower extremities and can lead to damage to ligaments and osteochondral lesions. Up to 50 % of patients with a sprained ankle later develop a lesion of the cartilage in the ankle joint or an osteochondral lesion of the talus. This can lead to osteoarthritis of the injured ankle joint. Spontaneous healing is possible in all age groups in cases of a bone bruise in the subchondral bone but in isolated chondral injuries is only useful in pediatric patients. In many cases chondral and osteochondral injuries lead to increasing demarcation of the affected area and can result in progressive degeneration of the joint if not recognized in time. There also exist a certain number of osteochondral changes of the articular surface of the talus without any history of relevant trauma, which are collectively grouped under the term osteochondrosis dissecans. Perfusion disorders are discussed as one of many possible causes of these alterations. Nowadays, chondral and osteochondral defects can be treated earlier due to detection using very sensitive magnetic resonance imaging (MRI) and computed tomography (CT) techniques. The use of conservative treatment only has a chance of healing in pediatric patients. Conservative measures for adults should only be considered as adjuvant treatment to surgery.Based on a comprehensive analysis of the current literature, this article gives an overview and critical analysis of the current concepts for treatment of chondral and osteochondral injuries and lesions of the talus. With arthroscopic therapy curettage and microfracture of talar lesions are the predominant approaches or retrograde drilling of the defect is another option when the chondral coating is retained. Implantation of autologous chondral cells or homologous juvenile cartilage tissue is also possible with arthroscopic techniques. Osteochondral fractures (flake fracture) are usually performed as a mini-open procedure supported by arthroscopy. The use of the osteochondral autograft transfer system (OATS), implantation of membranes with or without autologous bone marrow transfer and possibly with growth factors or implantation of stem cells are carried out in combination with arthroscopic mini-open procedures. The results from the literature are discussed and compared with own results after arthroscopic treatment of chondral lesions of the talus.

Investigation into some characteristics of the mass-customized production paradigm

NASA Astrophysics Data System (ADS)

Tapper, Jerome; Sundar, Pratap S.; Kamarthi, Sagar V.

2000-10-01

In recent times, while markets are reaching their saturation limits and customers are becoming more demanding, a paradigm shift has been taking place from mass production to mass- customized production (MCP). The concept of mass customization (MC) focuses on satisfying a customer's unique needs with the help of new technologies such as Internet, digital product realization, and re-configurable production facilities. In MC the needs of an individual customer are translated into design, accordingly produced, and delivered to the customer. In this research three hypothesis related to MCP are investigated by the data/information collected from ten companies, which are engaged in MCP. These three hypothesis are (1) mass-customized production systems can be classified into make-to-stock MCP, assemble-to-order MCP, make-to-order MCP, engineer-to-order MC, and develop-to-order MCP, (2) in mass-customized production systems the process of customization eliminates customer sacrifice, and (3) mass-customized production systems can deliver products at mass-production cost. The preliminary study indicates that while the first hypothesis is valid, MCP companies rarely fulfill what is stated in the other two hypotheses.

Protein Design for Pathway Engineering

PubMed Central

Eriksen, Dawn T.; Lian, Jiazhang; Zhao, Huimin

2013-01-01

Design and construction of biochemical pathways has increased the complexity of biosynthetically-produced compounds when compared to single enzyme biocatalysis. However, the coordination of multiple enzymes can introduce a complicated set of obstacles to overcome in order to achieve a high titer and yield of the desired compound. Metabolic engineering has made great strides in developing tools to optimize the flux through a target pathway, but the inherent characteristics of a particular enzyme within the pathway can still limit the productivity. Thus, judicious protein design is critical for metabolic and pathway engineering. This review will describe various strategies and examples of applying protein design to pathway engineering to optimize the flux through the pathway. The proteins can be engineered for altered substrate specificity/selectivity, increased catalytic activity, reduced mass transfer limitations through specific protein localization, and reduced substrate/product inhibition. Protein engineering can also be expanded to design biosensors to enable high through-put screening and to customize cell signaling networks. These strategies have successfully engineered pathways for significantly increased productivity of the desired product or in the production of novel compounds. PMID:23558037

Protein design for pathway engineering.

PubMed

Eriksen, Dawn T; Lian, Jiazhang; Zhao, Huimin

2014-02-01

Design and construction of biochemical pathways has increased the complexity of biosynthetically-produced compounds when compared to single enzyme biocatalysis. However, the coordination of multiple enzymes can introduce a complicated set of obstacles to overcome in order to achieve a high titer and yield of the desired compound. Metabolic engineering has made great strides in developing tools to optimize the flux through a target pathway, but the inherent characteristics of a particular enzyme within the pathway can still limit the productivity. Thus, judicious protein design is critical for metabolic and pathway engineering. This review will describe various strategies and examples of applying protein design to pathway engineering to optimize the flux through the pathway. The proteins can be engineered for altered substrate specificity/selectivity, increased catalytic activity, reduced mass transfer limitations through specific protein localization, and reduced substrate/product inhibition. Protein engineering can also be expanded to design biosensors to enable high through-put screening and to customize cell signaling networks. These strategies have successfully engineered pathways for significantly increased productivity of the desired product or in the production of novel compounds. Copyright © 2013 Elsevier Inc. All rights reserved.

Gene gymnastics

PubMed Central

Vijayachandran, Lakshmi S; Thimiri Govinda Raj, Deepak B; Edelweiss, Evelina; Gupta, Kapil; Maier, Josef; Gordeliy, Valentin; Fitzgerald, Daniel J; Berger, Imre

2013-01-01

Most essential activities in eukaryotic cells are catalyzed by large multiprotein assemblies containing up to ten or more interlocking subunits. The vast majority of these protein complexes are not easily accessible for high resolution studies aimed at unlocking their mechanisms, due to their low cellular abundance and high heterogeneity. Recombinant overproduction can resolve this bottleneck and baculovirus expression vector systems (BEVS) have emerged as particularly powerful tools for the provision of eukaryotic multiprotein complexes in high quality and quantity. Recently, synthetic biology approaches have begun to make their mark in improving existing BEVS reagents by de novo design of streamlined transfer plasmids and by engineering the baculovirus genome. Here we present OmniBac, comprising new custom designed reagents that further facilitate the integration of heterologous genes into the baculovirus genome for multiprotein expression. Based on comparative genome analysis and data mining, we herein present a blueprint to custom design and engineer the entire baculovirus genome for optimized production properties using a bottom-up synthetic biology approach. PMID:23328086

Dual compile strategy for parallel heterogeneous execution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Tyler Barratt; Perry, James Thomas

2012-06-01

The purpose of the Dual Compile Strategy is to increase our trust in the Compute Engine during its execution of instructions. This is accomplished by introducing a heterogeneous Monitor Engine that checks the execution of the Compute Engine. This leads to the production of a second and custom set of instructions designed for monitoring the execution of the Compute Engine at runtime. This use of multiple engines differs from redundancy in that one engine is working on the application while the other engine is monitoring and checking in parallel instead of both applications (and engines) performing the same work atmore » the same time.« less

Computer-aided engineering of semiconductor integrated circuits

NASA Astrophysics Data System (ADS)

Meindl, J. D.; Dutton, R. W.; Gibbons, J. F.; Helms, C. R.; Plummer, J. D.; Tiller, W. A.; Ho, C. P.; Saraswat, K. C.; Deal, B. E.; Kamins, T. I.

1980-07-01

Economical procurement of small quantities of high performance custom integrated circuits for military systems is impeded by inadequate process, device and circuit models that handicap low cost computer aided design. The principal objective of this program is to formulate physical models of fabrication processes, devices and circuits to allow total computer-aided design of custom large-scale integrated circuits. The basic areas under investigation are (1) thermal oxidation, (2) ion implantation and diffusion, (3) chemical vapor deposition of silicon and refractory metal silicides, (4) device simulation and analytic measurements. This report discusses the fourth year of the program.

Design of 3D simulation engine for oilfield safety training

NASA Astrophysics Data System (ADS)

Li, Hua-Ming; Kang, Bao-Sheng

2015-03-01

Aiming at the demand for rapid custom development of 3D simulation system for oilfield safety training, this paper designs and implements a 3D simulation engine based on script-driven method, multi-layer structure, pre-defined entity objects and high-level tools such as scene editor, script editor, program loader. A scripting language been defined to control the system's progress, events and operating results. Training teacher can use this engine to edit 3D virtual scenes, set the properties of entity objects, define the logic script of task, and produce a 3D simulation training system without any skills of programming. Through expanding entity class, this engine can be quickly applied to other virtual training areas.

Surface Roughness and Morphology Customization of Additive Manufactured Open Porous Ti6Al4V Structures

PubMed Central

Pyka, Grzegorz; Kerckhofs, Greet; Papantoniou, Ioannis; Speirs, Mathew; Schrooten, Jan; Wevers, Martine

2013-01-01

Additive manufacturing (AM) is a production method that enables the building of porous structures with a controlled geometry. However, there is a limited control over the final surface of the product. Hence, complementary surface engineering strategies are needed. In this work, design of experiments (DoE) was used to customize post AM surface treatment for 3D selective laser melted Ti6Al4V open porous structures for bone tissue engineering. A two-level three-factor full factorial design was employed to assess the individual and interactive effects of the surface treatment duration and the concentration of the chemical etching solution on the final surface roughness and beam thickness of the treated porous structures. It was observed that the concentration of the surface treatment solution was the most important factor influencing roughness reduction. The designed beam thickness decreased the effectiveness of the surface treatment. In this case study, the optimized processing conditions for AM production and the post-AM surface treatment were defined based on the DoE output and were validated experimentally. This allowed the production of customized 3D porous structures with controlled surface roughness and overall morphological properties, which can assist in more controlled evaluation of the effect of surface roughness on various functional properties. PMID:28788357

Surface Roughness and Morphology Customization of Additive Manufactured Open Porous Ti6Al4V Structures.

PubMed

Pyka, Grzegorz; Kerckhofs, Greet; Papantoniou, Ioannis; Speirs, Mathew; Schrooten, Jan; Wevers, Martine

2013-10-22

Additive manufacturing (AM) is a production method that enables the building of porous structures with a controlled geometry. However, there is a limited control over the final surface of the product. Hence, complementary surface engineering strategies are needed. In this work, design of experiments (DoE) was used to customize post AM surface treatment for 3D selective laser melted Ti6Al4V open porous structures for bone tissue engineering. A two-level three-factor full factorial design was employed to assess the individual and interactive effects of the surface treatment duration and the concentration of the chemical etching solution on the final surface roughness and beam thickness of the treated porous structures. It was observed that the concentration of the surface treatment solution was the most important factor influencing roughness reduction. The designed beam thickness decreased the effectiveness of the surface treatment. In this case study, the optimized processing conditions for AM production and the post-AM surface treatment were defined based on the DoE output and were validated experimentally. This allowed the production of customized 3D porous structures with controlled surface roughness and overall morphological properties, which can assist in more controlled evaluation of the effect of surface roughness on various functional properties.

Focal Defects of the Knee Articular Surface: Evidence of a Regenerative Potential Pattern in Osteochondritis Dissecans and Degenerative Lesions

PubMed Central

Gabusi, Elena; Manferdini, Cristina; Paolella, Francesca; Gambari, Laura; Mariani, Erminia

2017-01-01

The surgical treatment of knee articular focal lesions may offer heterogeneous clinical results. Osteochondritis dissecans (OCD) lesions showed to heal better than degenerative lesions (DL) but the underlying biological reasons are unknown. We evaluated the basal histological and immunohistochemical characteristics of these lesions analyzing a series of osteochondral fragments from young patients with similar age but presenting different etiology. Osteochondral tissue samples were stained with Safranin O and graded using a histological score. Markers of mesenchymal progenitor cells (CD146), osteoclasts (tartrate-resistant acid phosphatase, TRAP), and vessels (CD34) were evaluated. Histological score showed a higher degeneration of both cartilage and bone compartments in OCD compared to DL fragments. Only CD146-positive cells were found at the same percentage in cartilage compartment of both DL and OCD patients. By contrast, in the bone compartment a significantly higher percentage of CD146, TRAP, and CD34 markers was found in OCD compared to DL patients. These data showed distinct histological characteristics of osteochondral focal lesions located in the same anatomical region but having a different etiology. The higher percentages of these markers in OCD than in DL, mainly associated with a high bone turnover, could help to explain the higher clinical healing potential of OCD patients. PMID:28770227

Water-based polyurethane 3D printed scaffolds with controlled release function for customized cartilage tissue engineering.

PubMed

Hung, Kun-Che; Tseng, Ching-Shiow; Dai, Lien-Guo; Hsu, Shan-hui

2016-03-01

Conventional 3D printing may not readily incorporate bioactive ingredients for controlled release because the process often involves the use of heat, organic solvent, or crosslinkers that reduce the bioactivity of the ingredients. Water-based 3D printing materials with controlled bioactivity for customized cartilage tissue engineering is developed in this study. The printing ink contains the water dispersion of synthetic biodegradable polyurethane (PU) elastic nanoparticles, hyaluronan, and bioactive ingredients TGFβ3 or a small molecule drug Y27632 to replace TGFβ3. Compliant scaffolds are printed from the ink at low temperature. These scaffolds promote the self-aggregation of mesenchymal stem cells (MSCs) and, with timely release of the bioactive ingredients, induce the chondrogenic differentiation of MSCs and produce matrix for cartilage repair. Moreover, the growth factor-free controlled release design may prevent cartilage hypertrophy. Rabbit knee implantation supports the potential of the novel 3D printing scaffolds in cartilage regeneration. We consider that the 3D printing composite scaffolds with controlled release bioactivity may have potential in customized tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Integration of COTS/GOTS within NASA's HST Command and Control System

NASA Technical Reports Server (NTRS)

Pfarr, Thomas; Reis, James E.; Obenschain, Arthur F. (Technical Monitor)

2001-01-01

NASA's mission critical Hubble Space Telescope (HST) command and control system has been re-engineered with COTS/GOTS and minimal custom code. This paper focuses on the design of this new HST Control Center System (CCS) and the lessons learned throughout its development. CCS currently utilizes 31 COTS/GOTS products with an additional 12 million lines of custom glueware code; the new CCS exceeds the capabilities of the original system while significantly reducing the lines of custom code by more than 50%. The lifecycle of COTS/GOTS products will be examined including the pack-age selection process, evaluation process, and integration process. The advantages, disadvantages, issues, concerns, and lessons teamed for integrating COTS/GOTS into the NASA's mission critical HST CCS will be examined in detail. Command and control systems designed with traditional custom code development efforts will be compared with command and control systems designed with new development techniques relying heavily on COTS/COTS integration. This paper will reveal the many hidden costs of COTS/GOTS solutions when compared to traditional custom code development efforts; this paper will show the high cost of COTS/GOTS solutions including training expenses, consulting fees, and long-term maintenance expenses.

How the Kano model contributes to Kansei engineering in services.

PubMed

Hartono, Markus; Chuan, Tan Kay

2011-11-01

Recent studies show that products and services hold great appeal if they are attractively designed to elicit emotional feelings from customers. Kansei engineering (KE) has good potential to provide a competitive advantage to those able to read and translate customer affect and emotion in actual product and services. This study introduces an integrative framework of the Kano model and KE, applied to services. The Kano model was used and inserted into KE to exhibit the relationship between service attribute performance and customer emotional response. Essentially, the Kano model categorises service attribute quality into three major groups (must-be [M], one-dimensional [O] and attractive [A]). The findings of a case study that involved 100 tourists who stayed in luxury 4- and 5-star hotels are presented. As a practical matter, this research provides insight on which service attributes deserve more attention with regard to their significant impact on customer emotional needs. STATEMENT OF RELEVANCE: Apart from cognitive evaluation, emotions and hedonism play a big role in service encounters. Through a focus on delighting qualities of service attributes, this research enables service providers and managers to establish the extent to which they prioritise their improvement efforts and to always satisfy their customer emotions beyond expectation.

A novel aragonite-based scaffold for osteochondral regeneration: early experience on human implants and technical developments.

PubMed

Kon, Elizaveta; Robinson, Dror; Verdonk, Peter; Drobnic, Matej; Patrascu, Jenel Mariano; Dulic, Oliver; Gavrilovic, Gordon; Filardo, Giuseppe

2016-12-01

Chondral and osteochondral lesions represent a debilitating disease. Untreated lesions remain a risk factor for more extensive joint damage. The objective of this clinical study is to evaluate safety and early results of an aragonite-based scaffold used for osteochondral unit repair, by analysing both clinical outcome and MRI results, as well as the benefits of the procedure optimization through novel tapered shaped implants. A crystalline aragonite bi-phasic scaffold was implanted in patients affected by focal chondral-osteochondral knee lesions of the condyle and trochlea. Twenty-one patients (17 men, 4 women with a mean age of 31.0 ± 8.6 years) without severe OA received tapered shaped implants for the treatment of 2.5 ±1.7 cm 2 sized defects. The control group consisted of 76 patients selected according to the same criteria from a database of patients who previously underwent implantation of cylindrical-shaped implants. The clinical outcome of all patients was evaluated with the IKDC subjective score, the Lysholm score, and all 5 KOOS subscales administered preoperatively and at 6 and 12 months after surgery, while MRI evaluation was performed at the 12 month follow-up. A statistically significant improvement in all clinical scores was documented both in the tapered implants and the cylindrical group. No difference could be detected in the comparison between the improvement obtained with the two implant types, neither in the clinical nor in imaging evaluations. A difference could be detected instead in terms of revision rate, which was lower in the tapered implant group with no implant removal - 0% vs 8/76-10.5% failures in the cylindrical implants. This study highlighted both safety and potential of a novel aragonite-based scaffold for the treatment of chondral and osteochondral lesions in humans. A tapered shape relative to the cylindrical shaped implant design, improved the scaffold's safety profile. Tapered scaffolds maintain the clinical improvement observed in cylindrical implants while reducing the postoperative risk of revision surgery. This aragonite-based implant was associated with a significant clinical improvement at the 12 month follow-up. Moreover, MRI findings revealed graft integration with good bone and cartilage formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

A fuzzy-match search engine for physician directories.

PubMed

Rastegar-Mojarad, Majid; Kadolph, Christopher; Ye, Zhan; Wall, Daniel; Murali, Narayana; Lin, Simon

2014-11-04

A search engine to find physicians' information is a basic but crucial function of a health care provider's website. Inefficient search engines, which return no results or incorrect results, can lead to patient frustration and potential customer loss. A search engine that can handle misspellings and spelling variations of names is needed, as the United States (US) has culturally, racially, and ethnically diverse names. The Marshfield Clinic website provides a search engine for users to search for physicians' names. The current search engine provides an auto-completion function, but it requires an exact match. We observed that 26% of all searches yielded no results. The goal was to design a fuzzy-match algorithm to aid users in finding physicians easier and faster. Instead of an exact match search, we used a fuzzy algorithm to find similar matches for searched terms. In the algorithm, we solved three types of search engine failures: "Typographic", "Phonetic spelling variation", and "Nickname". To solve these mismatches, we used a customized Levenshtein distance calculation that incorporated Soundex coding and a lookup table of nicknames derived from US census data. Using the "Challenge Data Set of Marshfield Physician Names," we evaluated the accuracy of fuzzy-match engine-top ten (90%) and compared it with exact match (0%), Soundex (24%), Levenshtein distance (59%), and fuzzy-match engine-top one (71%). We designed, created a reference implementation, and evaluated a fuzzy-match search engine for physician directories. The open-source code is available at the codeplex website and a reference implementation is available for demonstration at the datamarsh website.

Single board system for fuzzy inference

NASA Technical Reports Server (NTRS)

Symon, James R.; Watanabe, Hiroyuki

1991-01-01

The very large scale integration (VLSI) implementation of a fuzzy logic inference mechanism allows the use of rule-based control and decision making in demanding real-time applications. Researchers designed a full custom VLSI inference engine. The chip was fabricated using CMOS technology. The chip consists of 688,000 transistors of which 476,000 are used for RAM memory. The fuzzy logic inference engine board system incorporates the custom designed integrated circuit into a standard VMEbus environment. The Fuzzy Logic system uses Transistor-Transistor Logic (TTL) parts to provide the interface between the Fuzzy chip and a standard, double height VMEbus backplane, allowing the chip to perform application process control through the VMEbus host. High level C language functions hide details of the hardware system interface from the applications level programmer. The first version of the board was installed on a robot at Oak Ridge National Laboratory in January of 1990.

75 FR 34426 - Notice of Petitions by Firms for Determination of Eligibility To Apply for Trade Adjustment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-17

... The company designs and manufactures Company. City, MO 64108. custom tents and awnings. A. Rifkin... Engineering & 750 Broad Street, 5/17/2010 Electro Chemical manufactures steel tanks Manufacturing. Emmaus, PA.... TLX Technologies, LLC......... Saratoga Drive, 5/17/2010 The firm designs and manufactures Waukesha...

A Framework for Mapping User-Designed Forms to Relational Databases

ERIC Educational Resources Information Center

Khare, Ritu

2011-01-01

In the quest for database usability, several applications enable users to design custom forms using a graphical interface, and forward engineer the forms into new databases. The path-breaking aspect of such applications is that users are completely shielded from the technicalities of database creation. Despite this innovation, the process of…

Development of a software for the design of custom-made hip prostheses using an open-source rapid application development environment.

PubMed

Viceconti, M; Testi, D; Gori, R; Zannoni, C

2000-01-01

The present work describes a technology transfer project called HIPCOM devoted to the re-engineering of the process used by a medical devices manufacturer to design custom-made hip prostheses. Although it started with insufficient support from the end-user management, a very tight scheduling and a moderate budget, the project developed into what is considered by all partners a success story. In particular, the development of the design software, called HIPCOM Interactive Design Environment (HIDE) was completed in a time shorter than any optimistic expectation. The software was quite stable since its first beta version, and once introduced at the user site it fully replaced the original procedure in less than two months. One year after the early adoption, more than 80 custom-made prostheses had been designed with HIDE and the user had reported only two bugs, both cosmetics. The scope of the present work was to report the development experience and to investigate the reasons for these positive results, with particular reference to the development procedure and the software architecture. The choice of TCL/TK as development language and the adoption of well-defined software architecture were found to be the success key factors. Other important determinants were found to be the adoption of an incremental software engineering strategy, well suited for small to medium projects and the presence in the development staff of a technology transfer expert.

Regenerating Articular Tissue by Converging Technologies

PubMed Central

Paoluzzi, Luca; Pieper, Jeroen; de Wijn, Joost R.; van Blitterswijk, Clemens A.

2008-01-01

Scaffolds for osteochondral tissue engineering should provide mechanical stability, while offering specific signals for chondral and bone regeneration with a completely interconnected porous network for cell migration, attachment, and proliferation. Composites of polymers and ceramics are often considered to satisfy these requirements. As such methods largely rely on interfacial bonding between the ceramic and polymer phase, they may often compromise the use of the interface as an instrument to direct cell fate. Alternatively, here, we have designed hybrid 3D scaffolds using a novel concept based on biomaterial assembly, thereby omitting the drawbacks of interfacial bonding. Rapid prototyped ceramic particles were integrated into the pores of polymeric 3D fiber-deposited (3DF) matrices and infused with demineralized bone matrix (DBM) to obtain constructs that display the mechanical robustness of ceramics and the flexibility of polymers, mimicking bone tissue properties. Ostechondral scaffolds were then fabricated by directly depositing a 3DF structure optimized for cartilage regeneration adjacent to the bone scaffold. Stem cell seeded scaffolds regenerated both cartilage and bone in vivo. PMID:18716660

Optimized and Automated design of Plasma Diagnostics for Additive Manufacture

NASA Astrophysics Data System (ADS)

Stuber, James; Quinley, Morgan; Melnik, Paul; Sieck, Paul; Smith, Trevor; Chun, Katherine; Woodruff, Simon

2016-10-01

Despite having mature designs, diagnostics are usually custom designed for each experiment. Most of the design can be now be automated to reduce costs (engineering labor, and capital cost). We present results from scripted physics modeling and parametric engineering design for common optical and mechanical components found in many plasma diagnostics and outline the process for automated design optimization that employs scripts to communicate data from online forms through proprietary and open-source CAD and FE codes to provide a design that can be sent directly to a printer. As a demonstration of design automation, an optical beam dump, baffle and optical components are designed via an automated process and printed. Supported by DOE SBIR Grant DE-SC0011858.

The effect of requirements prioritization on avionics system conceptual design

NASA Astrophysics Data System (ADS)

Lorentz, John

This dissertation will provide a detailed approach and analysis of a new collaborative requirements prioritization methodology that has been used successfully on four Coast Guard avionics acquisition and development programs valued at $400M+. A statistical representation of participant study results will be discussed and analyzed in detail. Many technically compliant projects fail to deliver levels of performance and capability that the customer desires. Some of these systems completely meet "threshold" levels of performance; however, the distribution of resources in the process devoted to the development and management of the requirements does not always represent the voice of the customer. This is especially true for technically complex projects such as modern avionics systems. A simplified facilitated process for prioritization of system requirements will be described. The collaborative prioritization process, and resulting artifacts, aids the systems engineer during early conceptual design. All requirements are not the same in terms of customer priority. While there is a tendency to have many thresholds inside of a system design, there is usually a subset of requirements and system performance that is of the utmost importance to the design. These critical capabilities and critical levels of performance typically represent the reason the system is being built. The systems engineer needs processes to identify these critical capabilities, the associated desired levels of performance, and the risks associated with the specific requirements that define the critical capability. The facilitated prioritization exercise is designed to collaboratively draw out these critical capabilities and levels of performance so they can be emphasized in system design. Developing the purpose, scheduling and process for prioritization events are key elements of systems engineering and modern project management. The benefits of early collaborative prioritization flow throughout the project schedule, resulting in greater success during system deployment and operational testing. This dissertation will discuss the data and findings from participant studies, present a literature review of systems engineering and design processes, and test the hypothesis that the prioritization process had no effect on stakeholder sentiment related to the conceptual design. In addition, the "Requirements Rationalization" process will be discussed in detail. Avionics, like many other systems, has transitioned from a discrete electronics engineering, hard engineering discipline to incorporate software engineering as a core process of the technology development cycle. As with other software-based systems, avionics now has significant soft system attributes that must be considered in the design process. The boundless opportunities that exist in software design demand prioritization to focus effort onto the critical functions that the software must provide. This has been a well documented and understood phenomenon in the software development community for many years. This dissertation will attempt to link the effect of software integrated avionics to the benefits of prioritization of requirements in the problem space and demonstrate the sociological and technical benefits of early prioritization practices.

A general engineering scenario for concurrent engineering environments

NASA Astrophysics Data System (ADS)

Mucino, V. H.; Pavelic, V.

The paper describes an engineering method scenario which categorizes the various activities and tasks into blocks seen as subjects which consume and produce data and information. These methods, tools, and associated utilities interact with other engineering tools by exchanging information in such a way that a relationship between customers and suppliers of engineering data is established clearly, while data exchange consistency is maintained throughout the design process. The events and data transactions are presented in the form of flowcharts in which data transactions represent the connection between the various bricks, which in turn represent the engineering activities developed for the particular task required in the concurrent engineering environment.

User-friendly design approach for analog layout design

NASA Astrophysics Data System (ADS)

Li, Yongfu; Lee, Zhao Chuan; Tripathi, Vikas; Perez, Valerio; Ong, Yoong Seang; Hui, Chiu Wing

2017-03-01

Analog circuits are sensitives to the changes in the layout environment conditions, manufacturing processes, and variations. This paper presents analog verification flow with five types of analogfocused layout constraint checks to assist engineers in identifying any potential device mismatch and layout drawing mistakes. Compared to several solutions, our approach only requires layout design, which is sufficient to recognize all the matched devices. Our approach simplifies the data preparation and allows seamless integration into the layout environment with minimum disruption to the custom layout flow. Our user-friendly analog verification flow provides the engineer with more confident with their layouts quality.

NDSU undergraduate design projects for the disabled.

PubMed

Baczkowski, L S; Enderle, J D; Krause, D J; Rawson, J L

1990-01-01

Disabled persons of average means cannot afford custom made devices or adaptations to manufactured devices to meet their individual needs. Consequently, many disabled individuals have not been able to live as independently as society demands. At North Dakota State University, the need to give undergraduate electrical engineering students practical design experience has been fulfilled by requiring the students to design and build adaptive devices for the disabled. Consequently, the successful results of this effort have fulfilled the needs of two diverse human groups--student engineers and the disabled community. Presented is an effective approach used at North Dakota State University to manage senior design students.

Effect of Impaction Sequence on Osteochondral Graft Damage: The Role of Repeated and Varying Loads

PubMed Central

Kang, Richard W.; Friel, Nicole A.; Williams, James M.; Cole, Brian J.; Wimmer, Markus A.

2013-01-01

Background Osteochondral autografts and allografts require mechanical force for proper graft placement into the defect site; however, impaction compromises the tissue. This study aimed to determine the effect of impaction force and number of hits to seat the graft on cartilage integrity. Hypothesis Under constant impulse conditions, higher impaction load magnitudes are more detrimental to cell viability, matrix integrity and collagen network organization and will result in proteoglycan loss and nitric oxide release. Study Design Controlled laboratory study Methods Osteochondral explants, harvested from fresh bovine trochleas, were exposed to a series of consistent impact loads delivered by a pneumatically driven device. Each plug received the same overall impulse of 7 Ns, reflecting the mean of 23 clinically inserted plugs. Impaction loads of 37.5N, 75N, 150N, and 300N were matched with 74, 37, 21, and 11 hits respectively. Following impaction, the plugs were harvested and cartilage was analyzed for cell viability, histology by safranin-o and picosirius red, and release of sulfated glycosaminoglycans and nitric oxide. Data were compared with non-impacted control. Results Impacted plugs had significantly lower cell viability than non-impacted plugs. A dose response relationship in loss of cell viability with respect to load magnitude was seen immediately and after 4 days but lost after 8 days. Histologic analysis revealed intact cartilage surface in all samples (loaded or control), with loaded samples showing alterations in birefringence. While the sulfated GAG release was similar across varying impaction loads, release of nitric oxide increased with increasing impaction magnitudes and time. Conclusions Impaction loading parameters have a direct effect on the time course of the viability of the cartilage in the graft tissue. Clinical Relevance Optimal loading parameters for surgical impaction of osteochondral grafts are those with lower load magnitudes and a greater number of hits to ensure proper fit. PMID:19915099

Fixation of osteochondral fractures in rabbit knees. A comparison of Kirschner wires, fibrin sealant, and polydioxanone pins.

PubMed

Plaga, B R; Royster, R M; Donigian, A M; Wright, G B; Caskey, P M

1992-03-01

We compared fibrin sealant, polydioxanone (PDS) pins and Kirschner wires in the fixation of osteochondral fractures in rabbit knees. Standardised osteochondral fractures of the right medial femoral condyle were made in 56 adult New Zealand white rabbits. There were equal groups of control knees, and those which had Kirschner-wire, fibrin-sealant or PDS-pin fixation. No external immobilisation was used. One animal from each group was killed at two, three and four weeks. The remaining rabbits were killed at six weeks. A fracture which healed with less than 1 mm of displacement was considered a success. There was successful healing in 29% of the control group, in all of the Kirschner-wire group, in 50% of the fibrin-sealant group, and in 86% of the PDS-pin group. The use of PDS pins appears to be a reliable alternative to the use of metal in the fixation of osteochondral fractures in rabbits.

Arthroscopic retrograde osteochondral autologous transplantation to chondral lesion in femoral head.

PubMed

Cetinkaya, Sarper; Toker, Berkin; Taser, Omer

2014-06-01

This report describes the treatment of 2 cases of full-thickness cartilage defect of the femoral head. The authors performed osteochondral autologous transplantation with a different technique that has not been reported to date. One patient was 37 years old, and the other was 42 years old. Both presented with hip pain. In both patients, radiograph and magnetic resonance imaging scan showed a focal chondral defect on the weight-bearing area of the femoral head and acetabular impingement. A retrograde osteochondral autologous transplantation technique combined with hip arthroscopy and arthroscopic impingement treatment was performed. After a 2-month recovery period, the symptoms were resolved. In the first year of follow-up, Harris Hip scores improved significantly (case 1, 56.6 to 87.6; case 2, 58.6 to 90). The technique described yielded good short- and midterm clinical and radiologic outcomes. To the authors' knowledge, this report is the first to describe a retrograde osteochondral transplantation technique performed with hip arthroscopy in the femoral head. Copyright 2014, SLACK Incorporated.

Treatment of focal articular cartilage lesions of the knee with autogenous osteochondral graftsA 2- to 4-year follow-up study.

PubMed

Wang, Ching-Jen

2002-04-01

A retrospective study of 15 patients with 16 knees who underwent osteochondral autografts for focal full thickness articular cartilage defects of the knee with 2- to 4-year follow-up showed 80% good or excellent clinical results. There was no correlation of the clinical results with the underlying diagnoses, including osteonecrosis, osteochondritis dessicans and traumatic cartilage defect, or a size of the lesion smaller than 600 mm(2). However, cartilage lesions larger than 600 mm(2) were associated with increasing fibrous tissue formation and fissuring between the grafts and the host tissues and poor results. The improvement in symptoms appeared time-dependent, ranging from 6 to 16 weeks, suggesting that postoperative protection of the graft is warranted. There was no radiographic progression of degenerative changes of the knee on the medium-term follow-up. Therefore, an autogenous osteochondral graft is considered a good method in the treatment of knees with moderately sized articular cartilage defects.

Model-Based Engineering Design for Trade Space Exploration throughout the Design Cycle

NASA Technical Reports Server (NTRS)

Lamassoure, Elisabeth S.; Wall, Stephen D.; Easter, Robert W.

2004-01-01

This paper presents ongoing work to standardize model-based system engineering as a complement to point design development in the conceptual design phase of deep space missions. It summarizes two first steps towards practical application of this capability within the framework of concurrent engineering design teams and their customers. The first step is standard generation of system sensitivities models as the output of concurrent engineering design sessions, representing the local trade space around a point design. A review of the chosen model development process, and the results of three case study examples, demonstrate that a simple update to the concurrent engineering design process can easily capture sensitivities to key requirements. It can serve as a valuable tool to analyze design drivers and uncover breakpoints in the design. The second step is development of rough-order- of-magnitude, broad-range-of-validity design models for rapid exploration of the trade space, before selection of a point design. At least one case study demonstrated the feasibility to generate such models in a concurrent engineering session. The experiment indicated that such a capability could yield valid system-level conclusions for a trade space composed of understood elements. Ongoing efforts are assessing the practicality of developing end-to-end system-level design models for use before even convening the first concurrent engineering session, starting with modeling an end-to-end Mars architecture.

Comparative study of navigated versus freehand osteochondral graft transplantation of the knee.

PubMed

Koulalis, Dimitrios; Di Benedetto, Paolo; Citak, Mustafa; O'Loughlin, Padhraig; Pearle, Andrew D; Kendoff, Daniel O

2009-04-01

Osteochondral lesions are a common sports-related injury for which osteochondral grafting, including mosaicplasty, is an established treatment. Computer navigation has been gaining popularity in orthopaedic surgery to improve accuracy and precision. Navigation improves angle and depth matching during harvest and placement of osteochondral grafts compared with conventional freehand open technique. Controlled laboratory study. Three cadaveric knees were used. Reference markers were attached to the femur, tibia, and donor/recipient site guides. Fifteen osteochondral grafts were harvested and inserted into recipient sites with computer navigation, and 15 similar grafts were inserted freehand. The angles of graft removal and placement as well as surface congruity (graft depth) were calculated for each surgical group. The mean harvesting angle at the donor site using navigation was 4 degrees (standard deviation, 2.3 degrees ; range, 1 degrees -9 degrees ) versus 12 degrees (standard deviation, 5.5 degrees ; range, 5 degrees -24 degrees ) using freehand technique (P < .0001). The recipient plug removal angle using the navigated technique was 3.3 degrees (standard deviation, 2.1 degrees ; range, 0 degrees -9 degrees ) versus 10.7 degrees (standard deviation, 4.9 degrees ; range, 2 degrees -17 degrees ) in freehand (P < .0001). The mean navigated recipient plug placement angle was 3.6 degrees (standard deviation, 2.0 degrees ; range, 1 degrees -9 degrees ) versus 10.6 degrees (standard deviation, 4.4 degrees ; range, 3 degrees -17 degrees ) with freehand technique (P = .0001). The mean height of plug protrusion under navigation was 0.3 mm (standard deviation, 0.2 mm; range, 0-0.6 mm) versus 0.5 mm (standard deviation, 0.3 mm; range, 0.2-1.1 mm) using a freehand technique (P = .0034). Significantly greater accuracy and precision were observed in harvesting and placement of the osteochondral grafts in the navigated procedures. Clinical studies are needed to establish a benefit in vivo. Improvement in the osteochondral harvest and placement is desirable to optimize clinical outcomes. Navigation shows great potential to improve both harvest and placement precision and accuracy, thus optimizing ultimate surface congruity.

Stellar Inertial Navigation Workstation

NASA Technical Reports Server (NTRS)

Johnson, W.; Johnson, B.; Swaminathan, N.

1989-01-01

Software and hardware assembled to support specific engineering activities. Stellar Inertial Navigation Workstation (SINW) is integrated computer workstation providing systems and engineering support functions for Space Shuttle guidance and navigation-system logistics, repair, and procurement activities. Consists of personal-computer hardware, packaged software, and custom software integrated together into user-friendly, menu-driven system. Designed to operate on IBM PC XT. Applied in business and industry to develop similar workstations.

A new statistical method for design and analyses of component tolerance

NASA Astrophysics Data System (ADS)

Movahedi, Mohammad Mehdi; Khounsiavash, Mohsen; Otadi, Mahmood; Mosleh, Maryam

2017-03-01

Tolerancing conducted by design engineers to meet customers' needs is a prerequisite for producing high-quality products. Engineers use handbooks to conduct tolerancing. While use of statistical methods for tolerancing is not something new, engineers often use known distributions, including the normal distribution. Yet, if the statistical distribution of the given variable is unknown, a new statistical method will be employed to design tolerance. In this paper, we use generalized lambda distribution for design and analyses component tolerance. We use percentile method (PM) to estimate the distribution parameters. The findings indicated that, when the distribution of the component data is unknown, the proposed method can be used to expedite the design of component tolerance. Moreover, in the case of assembled sets, more extensive tolerance for each component with the same target performance can be utilized.

Multiple Osteochondral Allograft Transplantation with Concomitant Tibial Tubercle Osteotomy for Multifocal Chondral Disease of the Knee.

PubMed

Cotter, Eric J; Waterman, Brian R; Kelly, Mick P; Wang, Kevin C; Frank, Rachel M; Cole, Brian J

2017-08-01

Symptomatic patellofemoral chondral lesions are a challenging clinical entity, as these defects may result from persistent lateral patellar maltracking or repetitive microtrauma. Anteromedializing tibial tubercle osteotomy has been shown to be an effective strategy for primary and adjunctive treatment of focal or diffuse patellofemoral disease to improve the biomechanical loading environment. Similarly, osteochondral allograft transplantation has proven efficacy in physiologically young, high-demand patients with condylar or patellofemoral lesions, particularly without early arthritic progression. The authors present the surgical management of a young athlete with symptomatic tricompartmental focal chondral defects with fresh osteochondral allograft transplantation and anteromedializing tibial tubercle osteotomy.

Is retrograde drilling really useful for osteochondral lesion of talus with subchondral cyst?: A case report.

PubMed

Jeong, Seong-Yup; Kim, Jong-Kil; Lee, Kwang-Bok

2016-12-01

Retrograde drilling is a well accepted procedure for osteochondral lesion of the talus and subchondral cyst with intact overlying cartilage. It has good results in most reports. Compared to anterograde drilling, retrograde drilling can protect the integrity of the articular cartilage. The purpose of this study was to evaluate the suitability of using retrograde drilling for osteochondral lesion with subchondral cyst and discuss the mechanism involved in the development of subchondral cyst. We report a 53-year-old man who had complained left ankle pain that lasted over 6 months which was exacerbated by walking. We diagnosed it as osteochondral lesion of the talus with subchondral cyst. Plain X-ray, computed tomography, and magnetic resonance imaging (MRI) of the ankle. He undertook retrograde drilling without debridement of cartilage. After the surgery, the pain had been subsided for 1 year, although arthritic change had progressed. However, after 5 years of retrograde drilling, he revisited our hospital due to severe ankle pain. Plain X-ray and MRI showed arthritic change of the ankle and multiple cystic formation of talus. Retrograde drilling has some problem because this procedure is not theoretically correct when the development of a subchondral cyst in osteochondral lesion of the talus is considered. In addition, retrograde drilling may impair uninjured bone marrow of the talus, resulting in the development of multiple cystic formations.

In Vivo Tracking of Mesechymal Stem Cells Using Fluorescent Nanoparticles in an Osteochondral Repair Model

PubMed Central

Lee, Jong Min; Kim, Byung-Soo; Lee, Haeshin; Im, Gun-Il

2012-01-01

We devised and tested an in vivo system to monitor the migration of mesenchymal stem cells (MSCs) within the marrow cavity. In vitro studies confirmed that platelet-derived growth factor (PDGF)-AA had the most potent chemotactic effect of the tested factors, and possessed the greatest number of receptors in MSCs. MSCs were labeled with fluorescent nanoparticles and injected into the marrow cavity of nude rats through osteochondral defects created in the distal femur. The defects were sealed with HCF (heparin-conjugated fibrin) or PDGF-AA-loaded HCF. In the HCF-only group, the nanoparticle-labeled MSCs dispersed outside the marrow cavity within 3 days after injection. In the PDGF-AA-loaded HCF group, the labeled cells moved time-dependently for 14 days toward the osteochondral defect. HCF-PDGF in low dose (LD; 8.5 ng/µl) was more effective than HCF-PDGF in high dose (HD; 17 ng/µl) in recruiting the MSCs to the osteochondral defect. After 21 days, the defects treated with PDGF and transforming growth factor (TGF)-β1-loaded HCF showed excellent cartilage repair compared with other groups. Further studies confirmed that this in vivo osteochondral MSCs tracking system (IOMTS) worked for other chemoattractants (chemokine (C-C motif) ligand 2 (CCL2) and PDGF-BB). IOMTS can provide a useful tool to examine the effect of growth factors or chemokines on endogenous cartilage repair. PMID:22491215

Osteochondral autograft transplantation for juvenile osteochondritis dissecans of the knee: a series of twelve cases.

PubMed

Sasaki, Ken; Matsumoto, Tomoyuki; Matsushita, Takehiko; Kubo, Seiji; Ishida, Kazunari; Tei, Katsumasa; Akisue, Toshihiro; Kurosaka, Masahiro; Kuroda, Ryosuke

2012-11-01

The purpose of this study was to evaluate the clinical outcomes of osteochondral autograft transplantation (OAT) for juvenile osteochondritis dissecans (JOCD) lesions of the knee, especially time to return to sports. Twelve knee JOCD lesions with OCD grade 3 and 4 categorised by magnetic resonance imaging (MRI) were treated with OAT. Nine male and two female skeletally immature patients averaging 13.7 years old were included. The OCD lesions were assessed arthroscopically and then fixed in situ using multiple osteochondral plugs harvested under fluoroscopy from the distal femoral condyle without damaging the physis. International Cartilage Repair Society (ICRS) score and Lysholm score were assessed pre- and postoperatively. After a mean follow-up of 26.2 ± 15.1 months, the International Knee Documentation Committee (IKDC) subjective score significantly improved (p < 0.01). According to the IKDC score, objective assessment showed that ten of 12 (83 %) had excellent results (score: A) after OAT and significantly improved (p < 0.01). Based on ICRS criteria, results were satisfactory in all patients. No patients experienced complications at the graft harvest site. All patients returned to their previous level of athletic activity at an average of 5.7 months after the surgery. OAT for JOCD of the knee provided satisfactory results in all patients at a mean follow-up of 26.2 months.

Optical engineering capstone design projects with industry sponsors

NASA Astrophysics Data System (ADS)

Bunch, Robert M.; Leisher, Paul O.; Granieri, Sergio C.

2014-09-01

Capstone senior design is the culmination of a student's undergraduate engineering education that prepares them for engineering practice. In fact, any engineering degree program that pursues accreditation by the Engineering Accreditation Commission of ABET must contain "a major design experience based on the knowledge and skills acquired in earlier course work and incorporating appropriate engineering standards and multiple realistic constraints." At Rose-Hulman, we offer an interdisciplinary Optical Engineering / Engineering Physics senior design curriculum that meets this requirement. Part of this curriculum is a two-course sequence where students work in teams on a design project leading to a functional prototype. The students begin work on their capstone project during the first week of their senior year. The courses are deliverable-driven and the students are held accountable for regular technical progress through weekly updates with their faculty advisor and mid-term design reviews. We have found that client-sponsored projects offer students an enriched engineering design experience as it ensures consideration of constraints and standards requirements similar to those that they will encounter as working engineers. Further, client-sponsored projects provide teams with an opportunity for regular customer interactions which help shape the product design. The process that we follow in both soliciting and helping to scope appropriate industry-related design projects will be described. In addition, an outline of the capstone course structure as well as methods used to hold teams accountable for technical milestones will be discussed. Illustrative examples of past projects will be provided.

Design of a hydraulic bending machine

Treesearch

Steven G. Hankel; Marshall Begel

2004-01-01

To keep pace with customer demands while phasing out old and unserviceable test equipment, the staff of the Engineering Mechanics Laboratory (EML) at the USDA Forest Service, Forest Products Laboratory, designed and assembled a hydraulic bending test machine. The EML built this machine to test dimension lumber, nominal 2 in. thick and up to 12 in. deep, at spans up to...

Rapid Development of Orion Structural Test Systems

NASA Astrophysics Data System (ADS)

Baker, Dave

2012-07-01

NASA is currently validating the Orion spacecraft design for human space flight. Three systems developed by G Systems using hardware and software from National Instruments play an important role in the testing of the new Multi- purpose crew vehicle (MPCV). A custom pressurization and venting system enables engineers to apply pressure inside the test article for measuring strain. A custom data acquisition system synchronizes over 1,800 channels of analog data. This data, along with multiple video and audio streams and calculated data, can be viewed, saved, and replayed in real-time on multiple client stations. This paper presents design features and how the system works together in a distributed fashion.

Design of Lesehan Chair by Using Kansei Engineering Method And Anthropometry Approach

NASA Astrophysics Data System (ADS)

Pambudi, A. T.; Suryoputro, M. R.; Sari, A. D.; Kurnia, R. D.

2016-01-01

Special Region of Yogyakarta (DIY) is known as city for academic. Many people come to get some education in college. They live in boarding house with some supporting facilities. The most common facilities is low table which lead students have to sit on the floor while studying on table which could cause higher risk of back pain and musculoskeletal disorder. To identify the solution to reduce back pain and musculoskeletal risk, it is needed to design a lesehan chair which also appropriate to customer needs. Kansei engineering method was used with a total of 30 respondents participated, 15 kansei words collected, and 12 kansei words selected by doing validation and reliability test. The result of this study showed that quality, aesthetics, and comfort level influence the design of lesehan chair. A design of lesehan chair was created by considering the suitable concept and merging it with the physical design and its anthropometry measurement. In this case, marginal homogeneity test is needed to identify the differences between each kansei words attribute and the design or product recommendation. The marginal homogeneity test results show that the design and product recommendation has fulfilled customer's desires and needs. For further research, it is needed to analyse and evaluate the posture of lesehan chair users in order to develop and improve its performance.

A review of rapid prototyping techniques for tissue engineering purposes.

PubMed

Peltola, Sanna M; Melchels, Ferry P W; Grijpma, Dirk W; Kellomäki, Minna

2008-01-01

Rapid prototyping (RP) is a common name for several techniques, which read in data from computer-aided design (CAD) drawings and manufacture automatically three-dimensional objects layer-by-layer according to the virtual design. The utilization of RP in tissue engineering enables the production of three-dimensional scaffolds with complex geometries and very fine structures. Adding micro- and nanometer details into the scaffolds improves the mechanical properties of the scaffold and ensures better cell adhesion to the scaffold surface. Thus, tissue engineering constructs can be customized according to the data acquired from the medical scans to match the each patient's individual needs. In addition RP enables the control of the scaffold porosity making it possible to fabricate applications with desired structural integrity. Unfortunately, every RP process has its own unique disadvantages in building tissue engineering scaffolds. Hence, the future research should be focused on the development of RP machines designed specifically for fabrication of tissue engineering scaffolds, although RP methods already can serve as a link between tissue and engineering.

Passaged adult chondrocytes can form engineered cartilage with functional mechanical properties: a canine model.

PubMed

Ng, Kenneth W; Lima, Eric G; Bian, Liming; O'Conor, Christopher J; Jayabalan, Prakash S; Stoker, Aaron M; Kuroki, Keiichi; Cook, Cristi R; Ateshian, Gerard A; Cook, James L; Hung, Clark T

2010-03-01

It was hypothesized that previously optimized serum-free culture conditions for juvenile bovine chondrocytes could be adapted to generate engineered cartilage with physiologic mechanical properties in a preclinical, adult canine model. Primary or passaged (using growth factors) adult chondrocytes from three adult dogs were encapsulated in agarose, and cultured in serum-free media with transforming growth factor-beta3. After 28 days in culture, engineered cartilage formed by primary chondrocytes exhibited only small increases in glycosaminoglycan content. However, all passaged chondrocytes on day 28 elaborated a cartilage matrix with compressive properties and glycosaminoglycan content in the range of native adult canine cartilage values. A preliminary biocompatibility study utilizing chondral and osteochondral constructs showed no gross or histological signs of rejection, with all implanted constructs showing excellent integration with surrounding cartilage and subchondral bone. This study demonstrates that adult canine chondrocytes can form a mechanically functional, biocompatible engineered cartilage tissue under optimized culture conditions. The encouraging findings of this work highlight the potential for tissue engineering strategies using adult chondrocytes in the clinical treatment of cartilage defects.

Custom-Designed Molecular Scissors for Site-Specific Manipulation of the Plant and Mammalian Genomes

NASA Astrophysics Data System (ADS)

Kandavelou, Karthikeyan; Chandrasegaran, Srinivasan

Zinc finger nucleases (ZFNs) are custom-designed molecular scissors, engineered to cut at specific DNA sequences. ZFNs combine the zinc finger proteins (ZFPs) with the nonspecific cleavage domain of the FokI restriction enzyme. The DNA-binding specificity of ZFNs can be easily altered experimentally. This easy manipulation of the ZFN recognition specificity enables one to deliver a targeted double-strand break (DSB) to a genome. The targeted DSB stimulates local gene targeting by several orders of magnitude at that specific cut site via homologous recombination (HR). Thus, ZFNs have become an important experimental tool to make site-specific and permanent alterations to genomes of not only plants and mammals but also of many other organisms. Engineering of custom ZFNs involves many steps. The first step is to identify a ZFN site at or near the chosen chromosomal target within the genome to which ZFNs will bind and cut. The second step is to design and/or select various ZFP combinations that will bind to the chosen target site with high specificity and affinity. The DNA coding sequence for the designed ZFPs are then assembled by polymerase chain reaction (PCR) using oligonucleotides. The third step is to fuse the ZFP constructs to the FokI cleavage domain. The ZFNs are then expressed as proteins by using the rabbit reticulocyte in vitro transcription/translation system and the protein products assayed for their DNA cleavage specificity.

Analytical Design Package (ADP2): A computer aided engineering tool for aircraft transparency design

NASA Technical Reports Server (NTRS)

Wuerer, J. E.; Gran, M.; Held, T. W.

1994-01-01

The Analytical Design Package (ADP2) is being developed as a part of the Air Force Frameless Transparency Program (FTP). ADP2 is an integrated design tool consisting of existing analysis codes and Computer Aided Engineering (CAE) software. The objective of the ADP2 is to develop and confirm an integrated design methodology for frameless transparencies, related aircraft interfaces, and their corresponding tooling. The application of this methodology will generate high confidence for achieving a qualified part prior to mold fabrication. ADP2 is a customized integration of analysis codes, CAE software, and material databases. The primary CAE integration tool for the ADP2 is P3/PATRAN, a commercial-off-the-shelf (COTS) software tool. The open architecture of P3/PATRAN allows customized installations with different applications modules for specific site requirements. Integration of material databases allows the engineer to select a material, and those material properties are automatically called into the relevant analysis code. The ADP2 materials database will be composed of four independent schemas: CAE Design, Processing, Testing, and Logistics Support. The design of ADP2 places major emphasis on the seamless integration of CAE and analysis modules with a single intuitive graphical interface. This tool is being designed to serve and be used by an entire project team, i.e., analysts, designers, materials experts, and managers. The final version of the software will be delivered to the Air Force in Jan. 1994. The Analytical Design Package (ADP2) will then be ready for transfer to industry. The package will be capable of a wide range of design and manufacturing applications.

Note: Design and fabrication of a simple versatile microelectrochemical cell and its accessories

NASA Astrophysics Data System (ADS)

Rajan, Viswanathan; Neelakantan, Lakshman

2015-09-01

A microelectrochemical cell housed in an optical microscope and custom-made accessories have been designed and fabricated, which allows performing spatially resolved corrosion measurements. The cell assembly was designed to directly integrate the reference electrode close to the capillary tip to avoid air bubbles. A hard disk along with an old optical microscope was re-engineered into a microgrinder, which made the vertical grinding of glass capillary tips very easy. A stepper motor was customized into a microsyringe pump to dispense a controlled volume of electrolyte through the capillary. A force sensitive resistor was used to achieve constant wetting area. The functionality of the developed instrument is demonstrated by studying μ-electrochemical behavior of worn surface on AA2014-T6 alloy.

Measurement of Civil Engineering Customer Satisfaction in Tactical Air Command: A Prototype Evaluation Program.

DTIC Science & Technology

1986-09-01

customers . The article states that in response to a White House Office of Consumer Affairs study and with the wide use of minicomputers: Companies are...D-A174 l16 MEASUREMENT OF CIVIL ENGINEERING CUSTOMER SRTISFACTIbN 1/ IN TACTICAL AIR CO (U) AIR FORCE INST OF TECH ...... RIGHT-PATTERSON AFB ON...BUREAU OF STANDARDS- 1963-A_ . -_- ’II I-F MEASUREMENT OF CIVIL ENGINEERING CUSTOMER SATISFACTION IN TACTICAL AIR COMMAND: A PROTOTYPE EVALUATION PROGRAM

Icing Research Tunnel (IRT) Force Measurement System (FMS)

NASA Technical Reports Server (NTRS)

Roberts, Paul W.

2012-01-01

An Electronics Engineer at the Glenn Research Center (GRC), requested the NASA Engineering and Safety Center (NESC) provide technical support for an evaluation of the existing force measurement system (FMS) at the GRC's Icing Research Tunnel (IRT) with the intent of developing conceptual designs to improve the tunnel's force measurement capability in order to better meet test customer needs. This report contains the outcome of the NESC technical review.

Osteochondral graft from the pre-achilles area for replacement of articular surface defects

NASA Astrophysics Data System (ADS)

Kuznetsov, V. V.; Pahomov, I. A.; Prohorenko, V. M.; Sadovoy, M. A.; Korel, A. V.; Zaydman, A. M.; Repin, A. V.; Gudi, S. M.; Korochkin, S. B.

2017-09-01

We substantiate a new technique for obtaining osteochondral autograft to replace osteochondral defects resulting from various lesions of the talar trochlea by means of morphological examination of the following microslides: talar cartilage (cadaver material), cartilage portion of the pre-achilles zone of the calcaneum, lateral femoral condyle, and necrotic area of the talus. Examination of the specimens of the pre-achilles cartilage of the calcaneus revealed a large number of poorly differentiated chondroblasts in the homogeneously stained extracellular matrix; the presence of all zones (superficial zone, zone of columnar structures, and "tidemark"). This is indicative of structural and functional preservation of this cartilage, which therefore can be considered as an autograft material.

Osteochondral lesions of the ankle joint in professional soccer players: treatment with autologous matrix-induced chondrogenesis.

PubMed

Valderrabano, Victor; Barg, Alexej; Alattar, Abdulhameed; Wiewiorski, Martin

2014-12-01

Acute and recurrent ankle sprains and other trauma to the ankle joint are common injuries in soccer and can be accompanied by or result in osteochondral lesions of the ankle joint, majorly of the talus. Conservative treatment frequently fails. Several operative treatment techniques exist; however, the choice of the right procedure is difficult due to lack of literature with a high level of evidence. We present our treatment method for acute and chronic ankle osteochondral lesions with cystic formation approached by a new surgical technique combining bone plasty and a collagen matrix (autologous matrix-induced chondrogenesis). Therapeutic, Level IV: Case series. © 2014 The Author(s).

Costo-osteochondral graft for post-traumatic osteonecrosis of the radial head in an adolescent boy.

PubMed

Iwai, S; Sato, K; Nakamura, T; Okazaki, M; Itoh, Y; Toyama, Y; Ikegami, H

2011-01-01

We present a case of post-traumatic osteonecrosis of the radial head in a 13-year-old boy which was treated with costo-osteochondral grafts. A satisfactory outcome was seen at a follow-up of two years and ten months. Although costo-osteochondral grafting has been used in the treatment of defects in articular cartilage, especially in the hand and the elbow, the extension of the technique to manage post-traumatic osteonecrosis of the radial head in a child has not previously been reported in the English language literature. Complete relief of pain was obtained and an improvement in the range of movement was observed. The long-term results remain uncertain.

Research pressure instrumentation for NASA Space Shuttle main engine, modification no. 5

NASA Technical Reports Server (NTRS)

Anderson, P. J.; Nussbaum, P.; Gustafson, G.

1984-01-01

The objective of the research project described is to define and demonstrate methods to advance the state of the art of pressure sensors for the space shuttle main engine (SSME). Silicon piezoresistive technology was utilized in completing tasks: generation and testing of three transducer design concepts for solid state applications; silicon resistor characterization at cryogenic temperatures; experimental chip mounting characterization; frequency response optimization and prototype design and fabrication. Excellent silicon sensor performance was demonstrated at liquid nitrogen temperature. A silicon resistor ion implant dose was customized for SSME temperature requirements. A basic acoustic modeling software program was developed as a design tool to evaluate frequency response characteristics.

Lessons Learned from Ares I Upper Stage Structures and Thermal Design

NASA Technical Reports Server (NTRS)

Ahmed, Rafiq

2012-01-01

The Ares 1 Upper Stage was part of the vehicle intended to succeed the Space Shuttle as the United States manned spaceflight vehicle. Although the Upper Stage project was cancelled, there were many lessons learned that are applicable to future vehicle design. Lessons learned that are briefly detailed in this Technical Memorandum are for specific technical areas such as tank design, common bulkhead design, thrust oscillation, control of flight and slosh loads, purge and hazardous gas system. In addition, lessons learned from a systems engineering and vehicle integration perspective are also included, such as computer aided design and engineering, scheduling, and data management. The need for detailed systems engineering in the early stages of a project is emphasized throughout this report. The intent is that future projects will be able to apply these lessons learned to keep costs down, schedules brief, and deliver products that perform to the expectations of their customers.

Influence of custom-made implant designs on the biomechanical performance for the case of immediate post-extraction placement in the maxillary esthetic zone: a finite element analysis.

PubMed

Chen, Jianyu; Zhang, Zhiguang; Chen, Xianshuai; Zhang, Xiao

2017-05-01

Due to the increasing adoption of immediate implantation strategies and the rapid development of the computer aided design/computer aided manufacturing technology, a therapeutic concept based on patient-specific implant dentistry has recently been reintroduced by many researchers. However, little information is available on the designs of custom-made dental implant systems, especially their biomechanical behavior. The influence of the custom-made implant designs on the biomechanical performance for both an immediate and a delayed loading protocol in the maxillary esthetic zone was evaluated by means of the finite element (FE) method. FE models of three dental implants were considered: a state of the art cylindrical implant and two custom-made implants designed by reverse engineering technology, namely a root-analogue implant and a root-analogue threaded implant. The von Mises stress distributions and micro-motions around the bone-implant interfaces were calculated using ANSYS software. In a comparison of the three implant designs for both loading protocols, a favorable biomechanical performance was observed for the use of root-analogue threaded implant which approximated the geometry of natural anterior tooth and maintained the original long-axis. The results indicated that bone-implant interfacial micro-motion was reduced and a favorable stress distribution after osseointegration was achieved.

Simscape Modeling Verification in the Simulink Development Environment

NASA Technical Reports Server (NTRS)

Volle, Christopher E. E.

2014-01-01

The purpose of the Simulation Product Group of the Control and Data Systems division of the NASA Engineering branch at Kennedy Space Center is to provide a realtime model and simulation of the Ground Subsystems participating in vehicle launching activities. The simulation software is part of the Spaceport Command and Control System (SCCS) and is designed to support integrated launch operation software verification, and console operator training. Using Mathworks Simulink tools, modeling engineers currently build models from the custom-built blocks to accurately represent ground hardware. This is time consuming and costly due to required rigorous testing and peer reviews to be conducted for each custom-built block. Using Mathworks Simscape tools, modeling time can be reduced since there would be no custom-code developed. After careful research, the group came to the conclusion it is feasible to use Simscape's blocks in MatLab's Simulink. My project this fall was to verify the accuracy of the Crew Access Arm model developed using Simscape tools running in the Simulink development environment.

Glenoid dysplasia and osteochondritis dissecans in a cat

PubMed Central

Schwarze, Rebecca A.; Tano, Cheryl A.; Carroll, Vincent W.

2015-01-01

A 2-year-old Maine coon cat was presented for a right forelimb lameness. Computed tomography of the shoulder revealed a shallow glenoid, osteophyte deposition at the caudal humeral head and medial glenoid, and an intra-articular osseous body. This cat had glenoid dysplasia and osteochondritis dissecans of the glenoid. PMID:26130839

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings.

PubMed

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P; Kravitz, Richard L; Owen, Richard R; Sullivan, J Greer; Wu, Albert W; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-09-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context.

Handheld emissions detector (HED): overview and development

NASA Astrophysics Data System (ADS)

Valentino, George J.; Schimmel, David

2009-05-01

Nova Engineering, Cincinnati OH, a division of L-3 Communications (L-3 Nova), under the sponsorship of Program Manager Soldier Warrior (PM-SWAR), Fort Belvoir, VA, has developed a Soldier portable, light-weight, hand-held, geolocation sensor and processing system called the Handheld Emissions Detector (HED). The HED is a broadband custom receiver and processor that allows the user to easily sense, direction find, and locate a broad range of emitters in the user's surrounding area. Now in its second design iteration, the HED incorporates a set of COTS components that are complemented with L-3 Nova custom RF, power, digital, and mechanical components, plus custom embedded and application software. The HED user interfaces are designed to provide complex information in a readily-understandable form, thereby providing actionable results for operators. This paper provides, where possible, the top-level characteristics of the HED as well as the rationale behind its design philosophy along with its applications in both DOD and Commercial markets.

Re-engineering: a prescription for hospitals.

PubMed

Bolton, C; Gordon, J R

1994-01-01

Previously applied mostly in large, private sector corporations, "re-engineering" is fast becoming a tool that hospitals can use to break away from the old to find a new and better way of doing things. Re-engineering, however, first requires strong leadership which is committed to employee involvement and re-inventing the process design to meet the needs of the customers. Once the transition has been completed, the processes and the organization must continue to be managed differently. This article reviews the processes involved in re-engineering, and discusses the implementation of the initiative at the Sunnybrook Health Science Centre in Toronto.

Evaluation of a press-fit osteochondral poly(ester-urethane) scaffold in a rabbit defect model.

PubMed

Dresing, Iska; Zeiter, Stephan; Auer, Jörg; Alini, Mauro; Eglin, David

2014-07-01

The purpose of this study was to evaluate the impact on osteochondral healing of press-fitted multiphasic osteochondral scaffolds consisting of poly(ester-urethane) (PUR) and hydroxyapatite into a cylindric osteochondral defect in the distal non-weight bearing femoral trochlear ridge of the rabbit. Two scaffolds were investigated, one with and one without an intermediate microporous membrane between the cartilage and the bone compartment of the scaffold. A control group without a scaffold placed into the defect was included. After 12 weeks macroscopic and histomorphological analyses were performed. The scaffold was easily press-fitted and provided a stable matrix for tissue repair. The membrane did not demonstrate a detrimental effect on tissue healing compared with the scaffold without membrane. However, the control group had statistically superior healing as reflected by histological differences in the cartilage and subchondral bone compartment between control group and each scaffold group. A more detailed analysis revealed that the difference was localized in the bone compartment healing. The present study demonstrates that an elastomeric PUR scaffold can easily be press-fitted into an osteochondral defect and provides a stable matrix for tissue repair. However, the multi-phasic scaffold did not provide a clear advantage for tissue healing. Future investigations should refine especially the bone phase of the implant to increase its stiffness, biocompatibility and osteoconductive activity. A more precise fabrication technique would be necessary for the matching of tissue organisation.

Advancements in Orthopedic Intervention: Retrograde Drilling and Bone Grafting of Osteochondral Lesions of the Knee Using Magnetic Resonance Imaging Guidance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seebauer, Christian J., E-mail: christian.seebauer@charite.d; Bail, Hermann J., E-mail: hermann-josef.bail@klinikum-nuernberg.d; Rump, Jens C., E-mail: jens.rump@charite.de

Computer-assisted surgery is currently a novel challenge for surgeons and interventional radiologists. Magnetic resonance imaging (MRI)-guided procedures are still evolving. In this experimental study, we describe and assess an innovative passive-navigation method for MRI-guided treatment of osteochondritis dissecans of the knee. A navigation principle using a passive-navigation device was evaluated in six cadaveric knee joint specimens for potential applicability in retrograde drilling and bone grafting of osteochondral lesions using MRI guidance. Feasibility and accuracy were evaluated in an open MRI scanner (1.0 T Philips Panorama HFO MRI System). Interactive MRI navigation allowed precise drilling and bone grafting of osteochondral lesionsmore » of the knee. All lesions were hit with an accuracy of 1.86 mm in the coronal plane and 1.4 mm the sagittal plane. Targeting of all lesions was possible with a single drilling. MRI allowed excellent assessment of correct positioning of the cancellous bone cylinder during bone grafting. The navigation device and anatomic structures could be clearly identified and distinguished throughout the entire drilling procedure. MRI-assisted navigation method using a passive navigation device is feasible for the treatment of osteochondral lesions of the knee under MRI guidance and allows precise and safe drilling without exposure to ionizing radiation. This method may be a viable alternative to other navigation principles, especially for pediatric and adolescent patients. This MRI-navigated method is also potentially applicable in many other MRI-guided interventions.« less

Dynamic impact force and association with structural damage to the knee joint: an ex-vivo study.

PubMed

Brill, Richard; Wohlgemuth, Walther A; Hempfling, Harald; Bohndorf, Klaus; Becker, Ursula; Welsch, Ulrich; Kamp, Alexander; Roemer, Frank W

2014-12-01

No systematic, histologically confirmed data are available concerning the association between magnitude of direct dynamic impact caused by vertical impact trauma and the resulting injury to cartilage and subchondral bone. The aim of this study was to investigate the association between dynamic impact and the resulting patterns of osteochondral injury in an ex-vivo model. A mechanical apparatus was employed to perform ex-vivo controlled dynamic vertical impact experiments in 110 pig knees with the femur positioned in a holding fixture. A falling body with a thrust plate and photo sensor was applied. The direct impact to the trochlear articular surface was registered and the resulting osteochondral injuries macroscopically and histologically correlated and categorized. The relationship between magnitude of direct impact and injury severity could be classified as stage I injuries (impact <7.3MPa): elastic deformation, no histological injury; stage II injuries (impact 7.3-9.6MPa): viscoelastic imprint of the cartilaginous surface, subchondral microfractures; stage III injuries (impact 9.6-12.7MPa): disrupted cartilage surface, chondral fissures and subchondral microfractures; stage IV injuries (impact >12.7MPa): osteochondral impression, histologically imprint and osteochondral macrofractures. The impact ranges and histologic injury stages determined from this vertical dynamic impact experiment allowed for a biomechanical classification of direct, acute osteochondral injury. In contrast to static load commonly applied in ex-vivo experiments, dynamic impact more realistically represents actual trauma to the knee joint.

Three phase power conversion system for utility interconnected PV applications

NASA Astrophysics Data System (ADS)

Porter, David G.

1999-03-01

Omnion Power Engineering Corporation has developed a new three phase inverter that improves the cost, reliability, and performance of three phase utility interconnected photovoltaic inverters. The inverter uses a new, high manufacturing volume IGBT bridge that has better thermal performance than previous designs. A custom easily manufactured enclosure was designed. Controls were simplified to increase reliability while maintaining important user features.

System engineering of complex optical systems for mission assurance and affordability

NASA Astrophysics Data System (ADS)

Ahmad, Anees

2017-08-01

Affordability and reliability are equally important as the performance and development time for many optical systems for military, space and commercial applications. These characteristics are even more important for the systems meant for space and military applications where total lifecycle costs must be affordable. Most customers are looking for high performance optical systems that are not only affordable but are designed with "no doubt" mission assurance, reliability and maintainability in mind. Both US military and commercial customers are now demanding an optimum balance between performance, reliability and affordability. Therefore, it is important to employ a disciplined systems design approach for meeting the performance, cost and schedule targets while keeping affordability and reliability in mind. The US Missile Defense Agency (MDA) now requires all of their systems to be engineered, tested and produced according to the Mission Assurance Provisions (MAP). These provisions or requirements are meant to ensure complex and expensive military systems are designed, integrated, tested and produced with the reliability and total lifecycle costs in mind. This paper describes a system design approach based on the MAP document for developing sophisticated optical systems that are not only cost-effective but also deliver superior and reliable performance during their intended missions.

Axial load-bearing capacity of an osteochondral autograft stabilized with a resorbable osteoconductive bone cement compared with a press-fit graft in a bovine model.

PubMed

Kiss, Marc-Olivier; Levasseur, Annie; Petit, Yvan; Lavigne, Patrick

2012-05-01

Osteochondral autografts in mosaicplasty are inserted in a press-fit fashion, and hence, patients are kept nonweightbearing for up to 2 months after surgery to allow bone healing and prevent complications. Very little has been published regarding alternative fixation techniques of those grafts. Osteochondral autografts stabilized with a resorbable osteoconductive bone cement would have a greater load-bearing capacity than standard press-fit grafts. Controlled laboratory study. Biomechanical testing was conducted on 8 pairs of cadaveric bovine distal femurs. For the first 4 pairs, 6 single osteochondral autografts were inserted in a press-fit fashion on one femur. On the contralateral femur, 6 grafts were stabilized with a calcium triglyceride osteoconductive bone cement. For the 4 remaining pairs of femurs, 4 groups of 3 adjacent press-fit grafts were inserted on one femur, whereas on the contralateral femur, grafts were cemented. After a maturation period of 48 hours, axial loading was applied on all single grafts and on the middle graft of each 3-in-a-row series. For the single-graft configuration, median loads required to sink the press-fit and cemented grafts by 2 and 3 mm were 281.87 N versus 345.56 N (P = .015) and 336.29 N versus 454.08 N (P = .018), respectively. For the 3-in-a-row configuration, median loads required to sink the press-fit and cemented grafts by 2 and 3 mm were 260.31 N versus 353.47 N (P = .035) and 384.83 N versus 455.68 N (P = .029), respectively. Fixation of osteochondral grafts using bone cement appears to improve immediate stability over the original mosaicplasty technique for both single- and multiple-graft configurations. Achieving greater primary stability of osteochondral grafts could potentially accelerate postoperative recovery, allowing early weightbearing and physical therapy.

Multi-Disciplinary Analysis for Future Launch Systems Using NASA's Advanced Engineering Environment (AEE)

NASA Technical Reports Server (NTRS)

Monell, D.; Mathias, D.; Reuther, J.; Garn, M.

2003-01-01

A new engineering environment constructed for the purposes of analyzing and designing Reusable Launch Vehicles (RLVs) is presented. The new environment has been developed to allow NASA to perform independent analysis and design of emerging RLV architectures and technologies. The new Advanced Engineering Environment (AEE) is both collaborative and distributed. It facilitates integration of the analyses by both vehicle performance disciplines and life-cycle disciplines. Current performance disciplines supported include: weights and sizing, aerodynamics, trajectories, propulsion, structural loads, and CAD-based geometries. Current life-cycle disciplines supported include: DDT&E cost, production costs, operations costs, flight rates, safety and reliability, and system economics. Involving six NASA centers (ARC, LaRC, MSFC, KSC, GRC and JSC), AEE has been tailored to serve as a web-accessed agency-wide source for all of NASA's future launch vehicle systems engineering functions. Thus, it is configured to facilitate (a) data management, (b) automated tool/process integration and execution, and (c) data visualization and presentation. The core components of the integrated framework are a customized PTC Windchill product data management server, a set of RLV analysis and design tools integrated using Phoenix Integration's Model Center, and an XML-based data capture and transfer protocol. The AEE system has seen production use during the Initial Architecture and Technology Review for the NASA 2nd Generation RLV program, and it continues to undergo development and enhancements in support of its current main customer, the NASA Next Generation Launch Technology (NGLT) program.

Improved osteochondral allograft preservation using serum-free media at body temperature.

PubMed

Garrity, Joseph T; Stoker, Aaron M; Sims, Hannah J; Cook, James L

2012-11-01

Osteochondral allografts (OCAs) are currently preserved at 4°C and used within 28 days of donor harvest. The window of opportunity for implantation is limited to 14 days due to a 2-week disease testing protocol. Osteochondral allograft tissues stored at 37°C will have significantly higher chondrocyte viability, as well as superior biochemical and biomechanical properties, than those stored at 4°C. Controlled laboratory study. Osteochondral allografts from 15 adult canine cadavers were aseptically harvested within 4 hours of death. Medial and lateral femoral condyles were stored in Media 1, similar to the current standard, or Media 2, an anti-inflammatory and chondrogenic media containing dexamethasone and transforming growth factor-β3, at 4°C or 37°C for up to 56 days. Chondrocyte viability, glycosaminoglycan (GAG) and collagen (hydroxyproline [HP]) content, biomechanical properties, and collagen II and aggrecan content were assessed at days 28 and 56. Five femoral condyles were stored overnight and assessed the next day to serve as controls. Storage in Media 1 at 37°C maintained chondrocyte viability at significantly higher levels than in any other media-temperature combination and at levels not significantly different from controls. Osteochondral allografts stored in either media at 4°C showed a significant decrease in chondrocyte viability throughout storage. Glycosaminoglycan and HP content were maintained through 56 days of storage in OCAs in Media 1 at 37°C. There were no significant differences in elastic or dynamic moduli among groups at day 56. Qualitative immunohistochemistry demonstrated the presence of collagen II and aggrecan throughout all layers of cartilage. Osteochondral allograft viability, matrix content and composition, and biomechanical properties were maintained at "fresh" levels through 56 days of storage in Media 1 at 37°C. Osteochondral allografts stored at 4°C were unable to maintain viability or matrix integrity through 28 days of storage. These findings suggest that storage of OCAs in a defined media at 37°C is superior to current protocols (4°C) for tissue preservation prior to transplantation. Storage of OCAs in serum-free chemically defined media at 37°C can increase the "window of opportunity" for implantation of optimal tissue from 14 days to 42 days after disease testing clearance.

Effects of osteochondral defect size on cartilage regeneration using a double-network hydrogel.

PubMed

Higa, Kotaro; Kitamura, Nobuto; Goto, Keiko; Kurokawa, Takayuki; Gong, Jian Ping; Kanaya, Fuminori; Yasuda, Kazunori

2017-05-22

There has been increased interest in one-step cell-free procedures to avoid the problems related to cell manipulation and its inherent disadvantages. We have studied the chondrogenic induction ability of a PAMPS/PDMAAm double-network (DN) gel and found it to induce chondrogenesis in animal osteochondral defect models. The purpose of this study was to investigate whether the healing process and the degree of cartilage regeneration induced by the cell-free method using DN gel are influenced by the size of osteochondral defects. A total of 63 mature female Japanese white rabbits were used in this study, randomly divided into 3 groups of 21 rabbits each. A 2.5-mm diameter osteochondral defect was created in the femoral trochlea of the patellofemoral joint of bilateral knees in Group I, a 4.3-mm osteochondral defect in Group II, and a 5.8-mm osteochondral defect in Group III. In the right knee of each animal, a DN gel plug was implanted so that a vacant space of 2-mm depth was left above the plug. In the left knee, we did not conduct any treatment to obtain control data. Animals were sacrificed at 2, 4, and 12 weeks after surgery, and gross and histological evaluations were made. The present study demonstrated that all sizes of the DN gel implanted defects as well as the 2.5mm untreated defects showed cartilage regeneration at 4 and 12 weeks. The 4.3-mm and 5.8-mm untreated defects did not show cartilage regeneration during the 12-week period. The quantitative score reported by O'Driscoll et al. was significantly higher in the 4.3-mm and 5.8-mm DN gel-implanted defects than the untreated defects at 4 and 12 weeks (p < 0.05). The 2.5-mm and 4.3-mm DN gel implanted defects maintained relatively high macroscopic and histological scores for the 12-week implantation period, while the histological score of the 5.8-mm DN gel implanted defect had decreased somewhat but statistically significantly at 12 weeks (p = 0.0057). The DN gel induced cartilage regeneration in defects between 2.5 and 5.8 mm, offering a promising device to establish a cell-free cartilage regeneration therapy and applicable to various sizes of osteochondral defects.

Design the Cost Approach in Trade-Off's for Structural Components, Illustrated on the Baseline Selection of the Engine Thrust Frame of Ariane 5 ESC-B

NASA Astrophysics Data System (ADS)

Appolloni, L.; Juhls, A.; Rieck, U.

2002-01-01

Designing for value is one of the very actual upcoming methods for design optimization, which broke into the domain of aerospace engineering in the late 90's. In the frame of designing for value two main design philosophies exist: Design For Cost and Design To Cost. Design To Cost is the iterative redesign of a project until the content of the project meets a given budget. Designing For Cost is the conscious use of engineering process technology to reduce life cycle cost while satisfying, and hopefully exceeding, customer demands. The key to understanding cost, and hence to reducing cost, is the ability to measure cost accurately and to allocate it appropriately to products. Only then can intelligent decisions be made. Therefore the necessity of new methods as "Design For Value" or "Design For Competitiveness", set up with a generally multidisciplinary approach to find an optimized technical solution driven by many parameters, depending on the mission scenario and the customer/market needs. Very often three, but not more than five parametric drivers are sufficient. The more variable exist, the higher is in fact the risk to find just a sub-optimized local and not the global optimum, and the less robust is the found solution against change of input parameters. When the main parameters for optimization have been identified, the system engineer has to communicate them to all design engineers, who shall take care of these assessment variables during the entire design and decision process. The design process which has taken to the definition of the feasible structural concepts for the Engine Thrust Frame of the Ariane 5 Upper Cryogenic Stage ESC-B follows these most actual design philosophy methodologies, and combines a design for cost approach, to a design to cost optimization loop. Ariane 5 is the first member of a family of heavy-lift launchers. It aims to evolve into a family of launchers that responds to the space transportation challenges of the 21st century. New upper stages, along with modifications to the main cryogenic stage and solid boosters, will increase performance and meet demands of a changing market. A two-steps approach was decided for future developments of the launcher upper stage, in order to increase the payload lift capability of Ariane 5. The first step ESC-A is scheduled for first launch in 2002. As later step ESC-B shall grow up to 12 tons in GTO orbit, with multiple restart capability, i.e. re-ignitable engine. Ariane 5 ESC-B first flight is targeted for 2006. It will be loaded with 28 metric tons of liquid oxygen and liquid hydrogen and powered by a new expander cycle engine "Vinci". The Vinci engine will be connected to the tanks of the ESC-B stage via the structure named from the designers ETF, or Engine Thrust Frame. In order to develop a design concept for the ETF component a trade off was performed, based on the most modern system engineering methodologies. This paper will describe the basis of the system engineering approach in the design to cost process, and illustrate such approach as it has been applied during the trade off for the baseline selection of the Engine Thrust Frame of Ariane 5 ESC-B.

Adaptation of a commercial robot for genome library replication

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uber, D.C.; Searles, W.L.

1994-01-01

This report describes tools and fixtures developed at the Human Genome Center at Lawrence Berkeley Laboratory for the Hewlett-Packard ORCA{trademark} (Optimized Robot for Chemical Analysis) to replicate large genome libraries. Photographs and engineering drawings of the various custom-designed components are included.

Ceramic hemi-unicondylar arthroplasty in an adolescent patient with idiopathic tibial chondrolysis.

PubMed

Dombroski, Derek; Garino, Jonathan; Lee, Gwo-Chin

2009-06-01

Despite recent advances in cartilage regeneration and restoration procedures, isolated, large, full-thickness cartilage lesions in young patients continue to pose significant challenges to patients and orthopedic surgeons. Treatment options for this difficult problem have traditionally included arthrodesis, osteotomy, osteochondral allograft, and prosthetic reconstruction. We present a case of an adolescent patient with isolated idiopathic lateral tibial chondrolysis treated with a custom ceramic hemi-unicondylar hemiarthroplasty. Preoperatively, a 3-dimensional computed tomography scan of the patient's knee was obtained to begin manufacturing a conforming custom ceramic insert that would articulate between the tibial base plate and the patient's native lateral femoral cartilage. Through a lateral parapatellar approach, the tibial preparation was carried out using the Zimmer M/G unicompartmental knee system (Warsaw, Indiana), and the tibial base plate was cemented into position in the standard fashion. A custom, conforming, prefabricated ceramic insert (CeramTec, Memphis, Tennessee) was then inserted onto the tibial base plate. At 5-year follow-up, this salvage procedure was successful in relieving pain and restoring function in this young patient. There were no signs of implant loosening or lysis. Magnetic resonance imaging of the knee at last follow-up revealed that the cartilage thickness of the patient's lateral femoral condyle remained unchanged. Unicondylar hemiarthroplasty performed in patients with large unipolar lesions in the knee can provide durable and reliable pain relief. Ceramic is a viable material that can be considered for articulation with native cartilage.

Repair of articular osteochondral defects of the knee joint using a composite lamellar scaffold.

PubMed

Lv, Y M; Yu, Q S

2015-04-01

The major problem with repair of an articular cartilage injury is the extensive difference in the structure and function of regenerated, compared with normal cartilage. Our work investigates the feasibility of repairing articular osteochondral defects in the canine knee joint using a composite lamellar scaffold of nano-ß-tricalcium phosphate (ß-TCP)/collagen (col) I and II with bone marrow stromal stem cells (BMSCs) and assesses its biological compatibility. The bone-cartilage scaffold was prepared as a laminated composite, using hydroxyapatite nanoparticles (nano-HAP)/collagen I/copolymer of polylactic acid-hydroxyacetic acid as the bony scaffold, and sodium hyaluronate/poly(lactic-co-glycolic acid) as the cartilaginous scaffold. Ten-to 12-month-old hybrid canines were randomly divided into an experimental group and a control group. BMSCs were obtained from the iliac crest of each animal, and only those of the third generation were used in experiments. An articular osteochondral defect was created in the right knee of dogs in both groups. Those in the experimental group were treated by implanting the composites consisting of the lamellar scaffold of ß-TCP/col I/col II/BMSCs. Those in the control group were left untreated. After 12 weeks of implantation, defects in the experimental group were filled with white semi-translucent tissue, protruding slightly over the peripheral cartilage surface. After 24 weeks, the defect space in the experimental group was filled with new cartilage tissues, finely integrated into surrounding normal cartilage. The lamellar scaffold of ß-TCP/col I/col II was gradually degraded and absorbed, while new cartilage tissue formed. In the control group, the defects were not repaired. This method can be used as a suitable scaffold material for the tissue-engineered repair of articular cartilage defects. Cite this article: Bone Joint Res 2015;4:56-64. ©2015 The British Editorial Society of Bone & Joint Surgery.

Precision engineering for future propulsion and power systems: a perspective from Rolls-Royce.

PubMed

Beale, Sam

2012-08-28

Rolls-Royce today is an increasingly global business, supplying integrated power systems to a wide variety of customers for use on land, at sea and in the air. Its reputation for 'delivering excellence' to these customers has been built largely on its gas turbine technology portfolio, and this reputation relies on the quality of the company's expertise in design, manufacture and delivery of services. This paper sets out to examine a number of examples, such as the high-pressure turbine blade, of the company's reliance on precision design and manufacture, highlighting how this precision contributes to customer satisfaction with its products. A number of measures the company is taking to accelerate its competitiveness in precision manufacture are highlighted, not least its extensive relationships with the academic research base. The paper finishes by looking briefly at the demands of the company's potential future product portfolio.

Software Manages Documentation in a Large Test Facility

NASA Technical Reports Server (NTRS)

Gurneck, Joseph M.

2001-01-01

The 3MCS computer program assists and instrumentation engineer in performing the 3 essential functions of design, documentation, and configuration management of measurement and control systems in a large test facility. Services provided by 3MCS are acceptance of input from multiple engineers and technicians working at multiple locations;standardization of drawings;automated cross-referencing; identification of errors;listing of components and resources; downloading of test settings; and provision of information to customers.

Tailoring Systems Engineering Processes in a Conceptual Design Environment: A Case Study at NASA Marshall Spaceflight Center's ACO

NASA Technical Reports Server (NTRS)

Mulqueen, John; Maples, C. Dauphne; Fabisinski, Leo, III

2012-01-01

This paper provides an overview of Systems Engineering as it is applied in a conceptual design space systems department at the National Aeronautics and Space Administration (NASA) Marshall Spaceflight Center (MSFC) Advanced Concepts Office (ACO). Engineering work performed in the NASA MFSC's ACO is targeted toward the Exploratory Research and Concepts Development life cycle stages, as defined in the International Council on Systems Engineering (INCOSE) System Engineering Handbook. This paper addresses three ACO Systems Engineering tools that correspond to three INCOSE Technical Processes: Stakeholder Requirements Definition, Requirements Analysis, and Integration, as well as one Project Process Risk Management. These processes are used to facilitate, streamline, and manage systems engineering processes tailored for the earliest two life cycle stages, which is the environment in which ACO engineers work. The role of systems engineers and systems engineering as performed in ACO is explored in this paper. The need for tailoring Systems Engineering processes, tools, and products in the ever-changing engineering services ACO provides to its customers is addressed.

Perl Embedded in PTC's Pro/ENGINEER, Version 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

2003-12-22

Pro-PERL (AKA Pro/PERL) is a Perl extension to the PTC Pro/TOOLKIT API to the PTC Pro/ENGINEER CAD application including an embedded interpreter. It can be used to automate and customize Pro/ENGINEER, create Vendor Neutral Archive (VNA) format files and re-create CAD models from the VNA files. This has applications in sanitizing classified CAD models created in a classified environment for transfer to an open environment, creating template models for modification to finished models by non-expert users, and transfer of design intent data to other modeling technologies.

Design and implementation of a project-based active/cooperative engineering design course for freshmen

NASA Astrophysics Data System (ADS)

Abdulaal, R. M.; Al-Bahi, A. M.; Soliman, A. Y.; Iskanderani, F. I.

2011-08-01

A project-based active/cooperative design course is planned, implemented, assessed and evaluated to achieve several desired engineering outcomes. The course allows freshman-level students to gain professional hands-on engineering design experience through an opportunity to practise teamwork, quality principles, communication skills, life-long learning, realistic constraints and awareness of current domestic and global challenges. Throughout successive design reports and in-class assignments, the students are required by the end of the semester to communicate, clearly and concisely, the details of their design both orally and in writing through a functional artefact/prototype, a design notebook, an A0 project poster and a final oral presentation. In addition to these direct assessment tools, several indirect measures are used to ensure triangulation. Assignments are based on customer expectations using a detailed checklist. This paper shows the direct and indirect assessment tools that indicated a high level of achievement of course learning outcomes and a high level of student satisfaction.

A definition of high-level decisions in the engineering of systems

NASA Astrophysics Data System (ADS)

Powell, Robert Anthony

The role of the systems engineer defines that he or she be proactive and guide the program manager and their customers through their decisions to enhance the effectiveness of system development---producing faster, better, and cheaper systems. The present lack of coverage in literature on what these decisions are and how they relate to each other may be a contributing factor to the high rate of failure among system projects. At the onset of the system development process, decisions have an integral role in the design of a system that meets stakeholders' needs. This is apparent during the design and qualification of both the Development System and the Operational System. The performance, cost and schedule of the Development System affect the performance of the Operational System and are affected by decisions that influence physical elements of the Development System. The performance, cost, and schedule of the Operational System is affected by decisions that influence physical elements of the Operational System. Traditionally, product and process have been designed using know-how and trial and error. However, the empiricism of engineers and program managers is limited which can, and has led to costly mistakes. To date, very little research has explored decisions made in the engineering of a system. In government, literature exists on procurement processes for major system development; but in general literature on decisions, how they relate to each other, and the key information requirements within one of two systems and across the two systems is not readily available. This research hopes to improve the processes inherent in the engineering of systems. The primary focus of this research is on department of defense (DoD) military systems, specifically aerospace systems and may generalize more broadly. The result of this research is a process tool, a Decision System Model, which can be used by systems engineers to guide the program manager and their customers through the decisions about concurrently designing and qualifying both the Development and Operational systems.

Customer satisfaction planning and industrial engineering move hospital towards in-house stockless program.

PubMed

Burton, R; Mauk, D

1993-03-01

By integrating customer satisfaction planning and industrial engineering techniques when examining internal costs and efficiencies, materiel managers are able to better realize what concepts will best meet their customers' needs. Defining your customer(s), applying industrial engineering techniques, completing work sampling studies, itemizing recommendations and benefits to each alternative, performing feasibility and cost-analysis matrixes and utilizing resources through productivity monitoring will get you on the right path toward selecting concepts to use. This article reviews the above procedures as they applied to one hospital's decision-making process to determine whether to incorporate a stockless inventory program. Through an analysis of customer demand, the hospital realized that stockless was the way to go, but not by outsourcing the function--the hospital incorporated an in-house stockless inventory program.

A Development of a System Enables Character Input and PC Operation via Voice for a Physically Disabled Person with a Speech Impediment

NASA Astrophysics Data System (ADS)

Tanioka, Toshimasa; Egashira, Hiroyuki; Takata, Mayumi; Okazaki, Yasuhisa; Watanabe, Kenzi; Kondo, Hiroki

We have designed and implemented a PC operation support system for a physically disabled person with a speech impediment via voice. Voice operation is an effective method for a physically disabled person with involuntary movement of the limbs and the head. We have applied a commercial speech recognition engine to develop our system for practical purposes. Adoption of a commercial engine reduces development cost and will contribute to make our system useful to another speech impediment people. We have customized commercial speech recognition engine so that it can recognize the utterance of a person with a speech impediment. We have restricted the words that the recognition engine recognizes and separated a target words from similar words in pronunciation to avoid misrecognition. Huge number of words registered in commercial speech recognition engines cause frequent misrecognition for speech impediments' utterance, because their utterance is not clear and unstable. We have solved this problem by narrowing the choice of input down in a small number and also by registering their ambiguous pronunciations in addition to the original ones. To realize all character inputs and all PC operation with a small number of words, we have designed multiple input modes with categorized dictionaries and have introduced two-step input in each mode except numeral input to enable correct operation with small number of words. The system we have developed is in practical level. The first author of this paper is physically disabled with a speech impediment. He has been able not only character input into PC but also to operate Windows system smoothly by using this system. He uses this system in his daily life. This paper is written by him with this system. At present, the speech recognition is customized to him. It is, however, possible to customize for other users by changing words and registering new pronunciation according to each user's utterance.

Custom Search Engines: Tools & Tips

ERIC Educational Resources Information Center

Notess, Greg R.

2008-01-01

Few have the resources to build a Google or Yahoo! from scratch. Yet anyone can build a search engine based on a subset of the large search engines' databases. Use Google Custom Search Engine or Yahoo! Search Builder or any of the other similar programs to create a vertical search engine targeting sites of interest to users. The basic steps to…

Satellite-instrument system engineering best practices and lessons

NASA Astrophysics Data System (ADS)

Schueler, Carl F.

2009-08-01

This paper focuses on system engineering development issues driving satellite remote sensing instrumentation cost and schedule. A key best practice is early assessment of mission and instrumentation requirements priorities driving performance trades among major instrumentation measurements: Radiometry, spatial field of view and image quality, and spectral performance. Key lessons include attention to technology availability and applicability to prioritized requirements, care in applying heritage, approaching fixed-price and cost-plus contracts with appropriate attention to risk, and assessing design options with attention to customer preference as well as design performance, and development cost and schedule. A key element of success either in contract competition or execution is team experience. Perhaps the most crucial aspect of success, however, is thorough requirements analysis and flowdown to specifications driving design performance with sufficient parameter margin to allow for mistakes or oversights - the province of system engineering from design inception to development, test and delivery.

Design of rocker switches for work-vehicles--an application of Kansei Engineering.

PubMed

Schütte, Simon; Eklund, Jörgen

2005-09-01

Rocker switches used in vehicles meet high demands partly due to the increased focus on customer satisfaction. Previous studies focused on ergonomics and usability rather than design for emotions and affection. The aim of this study was to determine how and to what extent engineering properties influence the perception of rocker switches. Secondary aims were to compare two types of rating scales and to determine consistency over time of the ratings. As a method Kansei Engineering was used, describing a product domain from a physical and semantic point of view. A model was built and validated, and recommendations for new designs were given. It was seen that the subjective impressions of robustness, precision and design are strongly influenced by the zero position, the contact position, the form-ratio, shape and the surface of rocker switches. A 7-point scale was found suitable. The Kansei ratings were consistent over time.

An analysis of microsystems development at Sandia National Laboratories

NASA Astrophysics Data System (ADS)

Herrera, Gilbert V.; Myers, David R.

2011-06-01

While Sandia initially was motivated to investigate emergent microsystem technology to miniaturize existing macroscale structures, present designs embody innovative approaches that directly exploit the fundamentally different material properties of a new technology at the micro- and nano-scale. Direct, hands-on experience with the emerging technology gave Sandia engineers insights that not only guided the evolution of the technology but also enabled them to address new applications that enlarged the customer base for the new technology. Sandia's early commitment to develop complex microsystems demonstrated the advantages that early adopters gain by developing an extensive design and process tool kit and a shared awareness of multiple approaches to achieve the multiple goals. As with any emergent technology, Sandia's program benefited from interactions with the larger technical community. However, custom development followed a spiral path of direct trial-and-error experience, analysis, quantification of materials properties at the micro- and nano-scale, evolution of design tools and process recipes, and an understanding of reliability factors and failure mechanisms even in extreme environments. The microsystems capability at Sandia relied on three key elements. The first was people: a mix of mechanical and semiconductor engineers, chemists, physical scientists, designers, and numerical analysts. The second was a unique facility that enabled the development of custom technologies without contaminating mainline product deliveries. The third was the arrival of specialized equipment as part of a Cooperative Research And Development Agreement (CRADA) enabled by the National Competitiveness Technology Transfer Act of 1989. Underpinning all these, the program was guided and sustained through the research and development phases by accomplishing intermediate milestones addressing direct mission needs.

Harnessing cell–biomaterial interactions for osteochondral tissue regeneration.

PubMed

Kim, Kyobum; Yoon, Diana M; Mikos, Antonios; Kasper, F Kurtis

2012-01-01

Articular cartilage that is damaged or diseased often requires surgical intervention to repair the tissue; therefore, tissue engineering strategies have been developed to aid in cartilage regeneration. Tissue engineering approaches often require the integration of cells, biomaterials, and growth factors to direct and support tissue formation. A variety of cell types have been isolated from adipose, bone marrow, muscle, and skin tissue to promote cartilage regeneration. The interaction of cells with each other and with their surrounding environment has been shown to play a key role in cartilage engineering. In tissue engineering approaches, biomaterials are commonly used to provide an initial framework for cell recruitment and proliferation and tissue formation. Modifications of the properties of biomaterials, such as creating sites for cell binding, altering their physicochemical characteristics, and regulating the delivery of growth factors, can have a significant influence on chondrogenesis. Overall, the goal is to completely restore healthy cartilage within an articular cartilage defect. This chapter aims to provide information about the importance of cell–biomaterial interactions for the chondrogenic differentiation of various cell populations that can eventually produce functional cartilage matrix that is indicative of healthy cartilage tissue.

Anatomic feature of deltoid ligament attachment in posteromedial osteochondral lesion of talar dome.

PubMed

Nakasa, Tomoyuki; Sawa, Mikiya; Ikuta, Yasunari; Yoshikawa, Masahiro; Tsuyuguchi, Yusuke; Adachi, Nobuo

2018-03-01

Osteochondral lesions of the talus (OLT) are recognized as being commonly associated with trauma. However, the etiology of OLT remains unclear. In the case of a posteromedial lesion of OLT (medial OLT), the deep layer of the deltoid ligament is located close to the medial OLT, and this relationship between a medial lesion and deltoid ligament could be a risk factor for medial OLT. The purpose of this study is to investigate the unique anatomic feature of the deep deltoid attachment to the talus in patients with medial OLT compared with patients with non-medial OLT. Forty ankles with medial OLT and 40 ankles without medial OLT were retrospectively reviewed in this study. On the coronal images of MRI, the attachment of deltoid ligament was measured. The continuity of the osteochondral fragment and its bed was evaluated on MRI and arthroscopic findings. Coronal MRI images showed that the attachment of the deep deltoid ligament to the medial OLT was broader and located more proximally than in non-medial OLT. The continuity of fibers from the insertion site of deltoid ligament to the talus to the osteochondral fragment was observed (76.7%). In the arthroscopic findings, the osteochondral fragment was obviously connected to the talus at the medial site in 85.2% of feet. The location of the deep deltoid ligament attachment to the medial OLT was more proximal and there was the possibility of these anatomic feature might contribute to the pathogenesis of medial OLT. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Requirements Development for the NASA Advanced Engineering Environment (AEE)

NASA Technical Reports Server (NTRS)

Rogers, Eric; Hale, Joseph P.; Zook, Keith; Gowda, Sanjay; Salas, Andrea O.

2003-01-01

The requirements development process for the Advanced Engineering Environment (AEE) is presented. This environment has been developed to allow NASA to perform independent analysis and design of space transportation architectures and technologies. Given the highly collaborative and distributed nature of AEE, a variety of organizations are involved in the development, operations and management of the system. Furthermore, there are additional organizations involved representing external customers and stakeholders. Thorough coordination and effective communication is essential to translate desired expectations of the system into requirements. Functional, verifiable requirements for this (and indeed any) system are necessary to fulfill several roles. Requirements serve as a contractual tool, configuration management tool, and as an engineering tool, sometimes simultaneously. The role of requirements as an engineering tool is particularly important because a stable set of requirements for a system provides a common framework of system scope and characterization among team members. Furthermore, the requirements provide the basis for checking completion of system elements and form the basis for system verification. Requirements are at the core of systems engineering. The AEE Project has undertaken a thorough process to translate the desires and expectations of external customers and stakeholders into functional system-level requirements that are captured with sufficient rigor to allow development planning, resource allocation and system-level design, development, implementation and verification. These requirements are maintained in an integrated, relational database that provides traceability to governing Program requirements and also to verification methods and subsystem-level requirements.

The Stromal Vascular Fraction From Fat Tissue in the Treatment of Osteochondral Knee Defect: Case Report

PubMed Central

Salikhov, Ramil Z.; Masgutov, Ruslan F.; Chekunov, Mikhail A.; Tazetdinova, Leysan G.; Masgutova, Galina; Teplov, Oleg V.; Galimov, Damir; Plakseichuk, Yuri; Yagudin, Ramil; Pankov, Igor O.; Rizvanov, Albert

2018-01-01

In this study we applied autologous fat tissue stromal vascular fraction (SVF) cells in combination with microfracturing technique in a 36-year-old man with an osteochondral lesion of the medial femoral condyle 8 months after the injury. Cell material was generated by fat tissue liposuction from the anterior abdominal wall with subsequent extraction of the SVF and injected through a mini-arthrotomy portal with subsequent fibrin sealant fixation. The follow-up period was 2 years. Clinical score improved from 23 to 96 according to IKDC and from 10 to 90 according to EQ-VAS at 24 months follow-up. Magnetic resonance imaging (MRI) before the surgery revealed an osteochondral lesion with development of significant trabecular edema that remained unchanged for 6 months despite conservative treatment. MRI 1 and 2 years after the surgery showed the recovery of the damaged cartilage thickness with somewhat uneven structure and a decrease in the trabecular edema of the femoral condyle. The use of SVF cells with fibrin sealant fixation might be a promising approach in the treatment of osteochondral joint lesions. Further studies are required. PMID:29900170

A Missense Mutation in the Aggrecan C-type Lectin Domain Disrupts Extracellular Matrix Interactions and Causes Dominant Familial Osteochondritis Dissecans

PubMed Central

Stattin, Eva-Lena; Wiklund, Fredrik; Lindblom, Karin; Önnerfjord, Patrik; Jonsson, Björn-Anders; Tegner, Yelverton; Sasaki, Takako; Struglics, André; Lohmander, Stefan; Dahl, Niklas; Heinegård, Dick; Aspberg, Anders

2010-01-01

Osteochondritis dissecans is a disorder in which fragments of articular cartilage and subchondral bone dislodge from the joint surface. We analyzed a five-generation family in which affected members had autosomal-dominant familial osteochondritis dissecans. A genome-wide linkage analysis identified aggrecan (ACAN) as a prime candidate gene for the disorder. Sequence analysis of ACAN revealed heterozygosity for a missense mutation (c.6907G > A) in affected individuals, resulting in a p.V2303M amino acid substitution in the aggrecan G3 domain C-type lectin, which mediates interactions with other proteins in the cartilage extracellular matrix. Binding studies with recombinant mutated and wild-type G3 proteins showed loss of fibulin-1, fibulin-2, and tenascin-R interactions for the V2303M protein. Mass spectrometric analyses of aggrecan purified from patient cartilage verified that V2303M aggrecan is produced and present in the tissue. Our results provide a molecular mechanism for the etiology of familial osteochondritis dissecans and show the importance of the aggrecan C-type lectin interactions for cartilage function in vivo. PMID:20137779

The effect of autologous adipose derived mesenchymal stem cell therapy in the treatment of a large osteochondral defect of the knee following unsuccessful surgical intervention of osteochondritis dissecans - a case study.

PubMed

Freitag, Julien; Shah, Kiran; Wickham, James; Boyd, Richard; Tenen, Abi

2017-07-14

A prospective analysis of the effect of autologous adipose derived mesenchymal stem cell (MSC) therapy in the treatment of an osteochondral defect of the knee with early progressive osteoarthritis following unsuccessful surgical intervention of osteochondritis dissecans (OCD). After failed conventional management of OCD a patient undergoes intra-articular MSC therapy. Patient outcome measures included the Numeric Pain Rating Scale (NPRS), the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Knee Injury and Osteoarthritis Outcome Score (KOOS). Structural outcome was assessed using MRI with the novel technique of T2 mapping used to indicate cartilage quality. Following MSC therapy the patient reported improvement in pain and function as measured by NPRS, WOMAC and KOOS. Repeat MRI analysis showed regeneration of cartilage. MRI T2 mapping indicated hyaline like cartilage regrowth. In this report, the use of MSCs, after unsuccessful conventional OCD management, resulted in structural, functional and pain improvement. These results highlight the need to further study the regenerative potential of MSC therapy. Australian and New Zealand Clinical Trial Registry Number - ACTRN12615000258550 (Date registered 19/03/2015 - retrospectively registered).

RosettaRemodel: A Generalized Framework for Flexible Backbone Protein Design

PubMed Central

Huang, Po-Ssu; Ban, Yih-En Andrew; Richter, Florian; Andre, Ingemar; Vernon, Robert; Schief, William R.; Baker, David

2011-01-01

We describe RosettaRemodel, a generalized framework for flexible protein design that provides a versatile and convenient interface to the Rosetta modeling suite. RosettaRemodel employs a unified interface, called a blueprint, which allows detailed control over many aspects of flexible backbone protein design calculations. RosettaRemodel allows the construction and elaboration of customized protocols for a wide range of design problems ranging from loop insertion and deletion, disulfide engineering, domain assembly, loop remodeling, motif grafting, symmetrical units, to de novo structure modeling. PMID:21909381

A Practical Guide for Managing Customer Service in Base Civil Engineering.

DTIC Science & Technology

1988-04-01

IMPROVING CUSTOMER SERVICE IN BASE CIVIL ENGINEERING Step One: Evaluate Present Service Quality .. ......... .11 Step Two: Develop and Clarify a...cross sectional viewpoint. In chapter three, specific steps will be presented for managers to evaluate and improve the present level of service quality in...customer service in base civil engineering or any other organization for that matter is to evaluate the present level of service quality (1:170). Data

Surface structure and tribology of legless squamate reptiles.

PubMed

Abdel-Aal, Hisham A

2018-03-01

Squamate reptiles (around 10,000 species of snakes and lizards) comprise a myriad of distinct terrestrial vertebrates. The diversity within this biological group offers a great opportunity for customized bio-inspired solutions that address a variety of current technological problems especially within the realm of surface engineering and tribology. One subgroup within squamata is of interest in that context, namely the legless reptiles (mainly snakes and few lizards). The promise of that group lies within their functional adaptation as manifested in optimized surface designs and locomotion that is distinguished by economy of effort even when functioning within hostile tribological environments. Legless reptiles are spread over a wide range in the planet, this geographical diversity demands customized response to local habitats. Customization, in turn, is facilitated through specialized surface design features. In legless reptiles, micro elements of texture, their geometry and topological layout advance mitigation of frictional effects both in locomotion and in general function. Lately, the synergy between functional traits and intrinsic surface features has emerged as focus of research across disciplines. Many investigations have sought to characterize the structural as well as the tribological response of legless species from an engineering point of view. Despite the sizable amount of data that have accumulated in the literature over the past two decades or so, no effort to review the available information, whence this review. This manuscript, therefore, endeavors to assess available data on surface metrology and tribological behavior of legless reptiles and to define aspects of that performance necessary to formulate an advanced paradigm for bio-inspired surface engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

Software engineering project management - A state-of-the-art report

NASA Technical Reports Server (NTRS)

Thayer, R. H.; Lehman, J. H.

1977-01-01

The management of software engineering projects in the aerospace industry was investigated. The survey assessed such features as contract type, specification preparation techniques, software documentation required by customers, planning and cost-estimating, quality control, the use of advanced program practices, software tools and test procedures, the education levels of project managers, programmers and analysts, work assignment, automatic software monitoring capabilities, design and coding reviews, production times, success rates, and organizational structure of the projects.

How to renovate a 50-year-old wastewater treating plant: Part 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunter, M.L.

1996-01-01

How does an existing refinery cost-effectively renovate wastewater/stormwater treating systems to meet today`s environmental regulations and standards? Faced with solving this problem, Amoco`s Whiting Refinery developed a project team consisting of plant and operations engineers, corporate project and design engineers, contractors and vendors to map out a strategy to re-engineer the existing wastewater treating plant (WWTP) and auxiliary functions. This case history shows how an old refinery limited by existing equipment, building space, operation`s availability requirements and costs divided the project into several design phases. The design team used a proactive approach with empowerment responsibilities to solve construction, equipment usagemore » and regulatory problems throughout the project`s lifetime. Focusing on front-end planning and customer service (the refinery), team members applied value-based engineering designs to keep costs down, implemented safe work practices during construction, used HAZOP reviews to scrutinize proposed designs for operating and maintenance procedures, etc. The result has been the renovation of a 50-year-old WWTP completed under budget, ontime and in compliance with federal mandates.« less

Pulsed electromagnetic fields after arthroscopic treatment for osteochondral defects of the talus: double-blind randomized controlled multicenter trial

PubMed Central

van Bergen, Christiaan JA; Blankevoort, Leendert; de Haan, Rob J; Sierevelt, Inger N; Meuffels, Duncan E; d'Hooghe, Pieter RN; Krips, Rover; van Damme, Geert; van Dijk, C Niek

2009-01-01

Background Osteochondral talar defects usually affect athletic patients. The primary surgical treatment consists of arthroscopic debridement and microfracturing. Although this is mostly successful, early sport resumption is difficult to achieve, and it can take up to one year to obtain clinical improvement. Pulsed electromagnetic fields (PEMFs) may be effective for talar defects after arthroscopic treatment by promoting tissue healing, suppressing inflammation, and relieving pain. We hypothesize that PEMF-treatment compared to sham-treatment after arthroscopy will lead to earlier resumption of sports, and aim at 25% increase in patients that resume sports. Methods/Design A prospective, double-blind, randomized, placebo-controlled trial (RCT) will be conducted in five centers throughout the Netherlands and Belgium. 68 patients will be randomized to either active PEMF-treatment or sham-treatment for 60 days, four hours daily. They will be followed-up for one year. The combined primary outcome measures are (a) the percentage of patients that resume and maintain sports, and (b) the time to resumption of sports, defined by the Ankle Activity Score. Secondary outcome measures include resumption of work, subjective and objective scoring systems (American Orthopaedic Foot and Ankle Society – Ankle-Hindfoot Scale, Foot Ankle Outcome Score, Numeric Rating Scales of pain and satisfaction, EuroQol-5D), and computed tomography. Time to resumption of sports will be analyzed using Kaplan-Meier curves and log-rank tests. Discussion This trial will provide level-1 evidence on the effectiveness of PEMFs in the management of osteochondral ankle lesions after arthroscopy. Trial registration Netherlands Trial Register (NTR1636) PMID:19591674

Microsphere-based gradient implants for osteochondral regeneration: a long-term study in sheep

PubMed Central

Mohan, Neethu; Gupta, Vineet; Sridharan, Banu Priya; Mellott, Adam J; Easley, Jeremiah T; Palmer, Ross H; Galbraith, Richard A; Key, Vincent H; Berkland, Cory J; Detamore, Michael S

2015-01-01

Background: The microfracture technique for cartilage repair has limited ability to regenerate hyaline cartilage. Aim: The current study made a direct comparison between microfracture and an osteochondral approach with microsphere-based gradient plugs. Materials & methods: The PLGA-based scaffolds had opposing gradients of chondroitin sulfate and β-tricalcium phosphate. A 1-year repair study in sheep was conducted. Results: The repair tissues in the microfracture were mostly fibrous and had scattered fissures with degenerative changes. Cartilage regenerated with the gradient plugs had equal or superior mechanical properties; had lacunated cells and stable matrix as in hyaline cartilage. Conclusion: This first report of gradient scaffolds in a long-term, large animal, osteochondral defect demonstrated potential for equal or better cartilage repair than microfracture. PMID:26418471

A systems engineering approach to AIS accreditation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, L.M.; Hunteman, W.J.

1994-04-01

The systems engineering model provides the vehicle for communication between the developer and the customer by presenting system facts and demonstrating the system in an organized form. The same model provides implementors with views of the system`s function and capability. The authors contend that the process of obtaining accreditation for a classified Automated Information System (AIS) adheres to the typical systems engineering model. The accreditation process is modeled as a ``roadmap`` with the customer represented by the Designed Accrediting Authority. The ``roadmap`` model reduces the amount of accreditation knowledge required of an AIS developer and maximizes the effectiveness of participationmore » in the accreditation process by making the understanding of accreditation a natural consequence of applying the model. This paper identifies ten ``destinations`` on the ``road`` to accreditation. The significance of each ``destination`` is explained, as are the potential consequences of its exclusion. The ``roadmap,`` which has been applied to a range of information systems throughout the DOE community, establishes a paradigm for the certification and accreditation of classified AISs.« less

Science and Engineering Education : Who is the Customer?

DTIC Science & Technology

2012-05-30

business relationships are at the heart of the negative consequences of misidentifying the student as customer [8]. Student evaluations of teachers are...Journal of Education Management , 8, 29-36. 7. Scott, S.V. (1999) The academic as service provider: is the customer ‘always right’? Journal of...Engineering Education: Who is the Customer ? 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Michael Courtney

A Measurement of Civil Engineering Customer Satisfaction.

DTIC Science & Technology

1987-09-01

to best represent civil engineering customers : military building managers , civilian building managers , and field grade officers. Building managers ...not know how well they are meeting the expectations of their customers . In their book on service management , 5- I8 Albrecht and Zemke fault American...Austin provide the simplest definition of a customer -- one who pays the bills .59 (2:45). In his book on service management , Richard Normann labels tile

Clinical and Radiological Regeneration of Large and Deep Osteochondral Defects of the Knee by Bone Augmentation Combined With Matrix-Guided Autologous Chondrocyte Transplantation.

PubMed

Zellner, Johannes; Grechenig, Stephan; Pfeifer, Christian G; Krutsch, Werner; Koch, Matthias; Welsch, Goetz; Scherl, Madeleine; Seitz, Johannes; Zeman, Florian; Nerlich, Michael; Angele, Peter

2017-11-01

Large osteochondral defects of the knee are a challenge for regenerative treatment. While matrix-guided autologous chondrocyte transplantation (MACT) represents a successful treatment for chondral defects, the treatment potential in combination with bone grafting by cancellous bone or bone block augmentation for large and deep osteochondral defects has not been evaluated. To evaluate 1- to 3-year clinical outcomes and radiological results on magnetic resonance imaging (MRI) after the treatment of large osteochondral defects of the knee with bone augmentation and MACT. Special emphasis is placed on different methods of bone grafting (cancellous bone grafting or bone block augmentation). Case series; Level of evidence, 4. Fifty-one patients were included. Five patients were lost to follow-up. This left 46 patients (mean age, 28.2 years) with a median follow-up time of 2 years. The 46 patients had 47 deep, large osteochondral defects of the knee joint (1 patient with bilateral defects; mean defect size, 6.7 cm 2 ). The origin of the osteochondral defects was osteochondritis dissecans (n = 34), osteonecrosis (n = 8), or subchondral cysts (n = 5). Depending on the depth, all defects were treated by cancellous bone grafting (defect depth ≤10 mm; n = 16) or bone block augmentation (defect depth >10 mm; n = 31) combined with MACT. Clinical outcomes were followed at 3 months, 6 months, 1 year, 2 years, and 3 years and evaluated using the International Knee Documentation Committee (IKDC) score and Cincinnati score. A magnetic resonance imaging (MRI) evaluation was performed at 1 and 2 years, and the magnetic resonance observation of cartilage repair tissue (MOCART) score with additional specific subchondral bone parameters (bone regeneration, bone signal quality, osteophytes, sclerotic areas, and edema) was analyzed. The clinical outcome scores revealed a significant increase at follow-up (6 months to 3 years) compared with the preclinical results. The median IKDC score increased from 42.6 preoperatively to 75.3 at 1 year, 79.7 at 2 years, and 84.3 at 3 years. The median Cincinnati score significantly increased from 39.8 preoperatively to 72.0 at 1 year, 78.0 at 2 years, and 80.3 at 3 years. The MRI evaluation revealed a MOCART score of 82.6 at 1 year without a deterioration at the later follow-up time point. Especially, the subchondral bone analysis showed successful regeneration. All bone blocks and cancellous bone grafts were integrated in the bony defects, and no chondrocyte transplant failure could be detected throughout the follow-up. Large and deep osteochondral defects of the knee joint can be treated successfully with bone augmentation and MACT. The treatment of shallow bony defects with cancellous bone grafting and deep bony defects with bone block augmentation shows promising results.

The influence of prototype testing in three-dimensional aortic models on fenestrated endograft design.

PubMed

Taher, Fadi; Falkensammer, Juergen; McCarte, Jamie; Strassegger, Johann; Uhlmann, Miriam; Schuch, Philipp; Assadian, Afshin

2017-06-01

The fenestrated Anaconda endograft (Vascutek/Terumo, Inchinnan, UK) is intended for the treatment of abdominal aortic aneurysms with an insufficient infrarenal landing zone. The endografts are custom-made with use of high-resolution, 1-mm-slice computed tomography angiography images. For every case, a nonsterile prototype and a three-dimensional (3D) model of the patient's aorta are constructed to allow the engineers as well as the physician to test-implant the device and to review the fit of the graft. The aim of this investigation was to assess the impact of 3D model construction and prototype testing on the design of the final sterile endograft. A prospectively held database on fenestrated endovascular aortic repair patients treated at a single institution was completed with data from the Vascutek engineers' prototype test results as well as the product request forms. Changes to endograft design based on prototype testing were assessed and are reported for all procedures. Between April 1, 2013, and August 18, 2015, 60 fenestrated Anaconda devices were implanted. Through prototype testing, engineers were able to identify and report potential risks to technical success related to use of the custom device for the respective patient. Theoretical concerns about endograft fit in the rigid model were expressed in 51 cases (85.0%), and the engineers suggested potential changes to the design of 21 grafts (35.0%). Thirteen cases (21.7%) were eventually modified after the surgeon's testing of the prototype. A second prototype was ordered in three cases (5.0%) because of extensive changes to endograft design, such as inclusion of an additional fenestration. Technical success rates were comparable for grafts that showed a perfect fit from the beginning and cases in which prototype testing resulted in a modification of graft design. Planning and construction of fenestrated endografts for complex aortic anatomies where exact fit and positioning of the graft are paramount to allow cannulation of the aortic branches are challenging. In the current series, approximately one in five endografts was modified after prototype testing in an aortic model. Eventually, success rates were comparable between the groups of patients with a good primary prototype fit and those in which the endograft design was altered. Prototype testing in 3D aortic models is a valuable tool to test the fit of a custom-made endograft before implantation. This may help avoid potentially debilitating adverse events associated with misaligned fenestrations and unconnected aortic branches. Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Osteochondritis dissecans of the patella in a XVII century player of the Florentine historic kickball.

PubMed

Lippi, Donatella; Matucci-Cerinic, Marco; Villari, Natale; Fornaciari, Gino; Mascalchi, Mario

2010-03-01

We report a case of osteochondritis dissecans in the patella of Francesco de' Medici, Prince of Capistrano, who lived from 1594 to 1614. He was known to play Florentine kick ball, a precursor of Rugby and American football, and speculate that trauma from this activity may have led to the lesion. Copyright 2009 Elsevier B.V. All rights reserved.

Return to sports after autogenous osteochondral mosaicplasty of the femoral condyles: 25 cases at a mean follow-up of 9 years.

PubMed

Cognault, J; Seurat, O; Chaussard, C; Ionescu, S; Saragaglia, D

2015-05-01

Autogenous osteochondral mosaicplasty is the most common cartilage restoration technique in standard clinical practice. The purpose of this study was to evaluate the return to sports 9 years after mosaicplasty of the femoral condyles. The long-term results of an osteochondral autograft show that patients can regain their pre-injury activity level. This study is based on a series of 25 patients with a mean age of 28.9 years (range, 16-44 years) who had stage 3 or 4 chondral lesions of the femoral condyles (according to the ICRS or ICRS-OCD scores). The origin of the lesion was osteochondritis dissecans (13 knees), osteochondral fracture sequelae (ten knees), or aseptic osteonecrosis (two knees). The average size of the lesion was 2.11 ± 0.9 cm(2). Ten patients (40%) had an associated procedure during the osteochondral autograft. The patients were assessed clinically (IKDC and Lysholm-Tegner scores) and radiographically by a reviewer independent of the team of operators. All patients were re-examined at a mean follow-up of 9 years (range, 6-15 years), with 84% satisfied or very satisfied with the procedure. The average IKDC was 74.5 ± 18.5 points. The average Lysholm score was 87.3 ± 11.6 points. The average Tegner score ranged from 6.35 ± 1.53 points prior to surgery to 5.60 ± 1.64 points after surgery (P = 0.001). The average loss was 0.64 points for patients whose presurgery Tegner score was greater than or equal to 7 (P = 0.019) and 0.3 points if lower than 7. The radiologic evaluation of 21 patients showed complete osteointegration of the grafts in 90% of cases. The results of the femoral condyle mosaic autografts are satisfactory, a mean of 9 years after surgery. The most active patients lowered their activity level while the more sedentary did not have to adapt their lifestyle. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Spontaneous hyaline cartilage regeneration can be induced in an osteochondral defect created in the femoral condyle using a novel double-network hydrogel.

PubMed

Yokota, Masashi; Yasuda, Kazunori; Kitamura, Nobuto; Arakaki, Kazunobu; Onodera, Shin; Kurokawa, Takayuki; Gong, Jian-Ping

2011-02-22

Functional repair of articular osteochondral defects remains a major challenge not only in the field of knee surgery but also in tissue regeneration medicine. The purpose is to clarify whether the spontaneous hyaline cartilage regeneration can be induced in a large osteochondral defect created in the femoral condyle by means of implanting a novel double-network (DN) gel at the bottom of the defect. Twenty-five mature rabbits were used in this study. In the bilateral knees of each animal, we created an osteochondral defect having a diameter of 2.4-mm in the medial condyle. Then, in 21 rabbits, we implanted a DN gel plug into a right knee defect so that a vacant space of 1.5-mm depth (in Group I), 2.5-mm depth (in Group II), or 3.5-mm depth (in Group III) was left. In the left knee, we did not apply any treatment to the defect to obtain the control data. All the rabbits were sacrificed at 4 weeks, and the gross and histological evaluations were performed. The remaining 4 rabbits underwent the same treatment as used in Group II, and real-time PCR analysis was performed at 4 weeks. The defect in Group II was filled with a sufficient volume of the hyaline cartilage tissue rich in proteoglycan and type-2 collagen. The Wayne's gross appearance and histology scores showed that Group II was significantly greater than Group I, III, and Control (p < 0.012). The relative expression level of type-2 collagen, aggrecan, and SOX9 mRNAs was significantly greater in Group II than in the control group (p < 0.023). This study demonstrated that spontaneous hyaline cartilage regeneration can be induced in vivo in an osteochondral defect created in the femoral condyle by means of implanting the DN gel plug at the bottom of the defect so that an approximately 2-mm deep vacant space was intentionally left in the defect. This fact has prompted us to propose an innovative strategy without cell culture to repair osteochondral lesions in the femoral condyle.

NASA Glenn Wind Tunnel Model Systems Criteria

NASA Technical Reports Server (NTRS)

Soeder, Ronald H.; Roeder, James W.; Stark, David E.; Linne, Alan A.

2004-01-01

This report describes criteria for the design, analysis, quality assurance, and documentation of models that are to be tested in the wind tunnel facilities at the NASA Glenn Research Center. This report presents two methods for computing model allowable stresses on the basis of the yield stress or ultimate stress, and it defines project procedures to test models in the NASA Glenn aeropropulsion facilities. Both customer-furnished and in-house model systems are discussed. The functions of the facility personnel and customers are defined. The format for the pretest meetings, safety permit process, and model reviews are outlined. The format for the model systems report (a requirement for each model that is to be tested at NASA Glenn) is described, the engineers responsible for developing the model systems report are listed, and the timetable for its delivery to the project engineer is given.

Key ingredients needed when building large data processing systems for scientists

NASA Technical Reports Server (NTRS)

Miller, K. C.

2002-01-01

Why is building a large science software system so painful? Weren't teams of software engineers supposed to make life easier for scientists? Does it sometimes feel as if it would be easier to write the million lines of code in Fortran 77 yourself? The cause of this dissatisfaction is that many of the needs of the science customer remain hidden in discussions with software engineers until after a system has already been built. In fact, many of the hidden needs of the science customer conflict with stated needs and are therefore very difficult to meet unless they are addressed from the outset in a system's architectural requirements. What's missing is the consideration of a small set of key software properties in initial agreements about the requirements, the design and the cost of the system.

Integrating Science and Engineering to Implement Evidence-Based Practices in Health Care Settings

PubMed Central

Wu, Shinyi; Duan, Naihua; Wisdom, Jennifer P.; Kravitz, Richard L.; Owen, Richard R.; Sullivan, Greer; Wu, Albert W.; Di Capua, Paul; Hoagwood, Kimberly Eaton

2015-01-01

Integrating two distinct and complementary paradigms, science and engineering, may produce more effective outcomes for the implementation of evidence-based practices in health care settings. Science formalizes and tests innovations, whereas engineering customizes and optimizes how the innovation is applied tailoring to accommodate local conditions. Together they may accelerate the creation of an evidence-based healthcare system that works effectively in specific health care settings. We give examples of applying engineering methods for better quality, more efficient, and safer implementation of clinical practices, medical devices, and health services systems. A specific example was applying systems engineering design that orchestrated people, process, data, decision-making, and communication through a technology application to implement evidence-based depression care among low-income patients with diabetes. We recommend that leading journals recognize the fundamental role of engineering in implementation research, to improve understanding of design elements that create a better fit between program elements and local context. PMID:25217100

Upstream Design and 1D-CAE

NASA Astrophysics Data System (ADS)

Sawada, Hiroyuki

Recently, engineering design environment of Japan is changing variously. Manufacturing companies are being challenged to design and bring out products that meet the diverse demands of customers and are competitive against those produced by rising countries(1). In order to keep and strengthen the competitiveness of Japanese companies, it is necessary to create new added values as well as conventional ones. It is well known that design at the early stages has a great influence on the final design solution. Therefore, design support tools for the upstream design is necessary for creating new added values. We have established a research society for 1D-CAE (1 Dimensional Computer Aided Engineering)(2), which is a general term for idea, methodology and tools applicable for the upstream design support, and discuss the concept and definition of 1D-CAE. This paper reports our discussion about 1D-CAE.

Computational protein design-the next generation tool to expand synthetic biology applications.

PubMed

Gainza-Cirauqui, Pablo; Correia, Bruno Emanuel

2018-05-02

One powerful approach to engineer synthetic biology pathways is the assembly of proteins sourced from one or more natural organisms. However, synthetic pathways often require custom functions or biophysical properties not displayed by natural proteins, limitations that could be overcome through modern protein engineering techniques. Structure-based computational protein design is a powerful tool to engineer new functional capabilities in proteins, and it is beginning to have a profound impact in synthetic biology. Here, we review efforts to increase the capabilities of synthetic biology using computational protein design. We focus primarily on computationally designed proteins not only validated in vitro, but also shown to modulate different activities in living cells. Efforts made to validate computational designs in cells can illustrate both the challenges and opportunities in the intersection of protein design and synthetic biology. We also highlight protein design approaches, which although not validated as conveyors of new cellular function in situ, may have rapid and innovative applications in synthetic biology. We foresee that in the near-future, computational protein design will vastly expand the functional capabilities of synthetic cells. Copyright © 2018. Published by Elsevier Ltd.

Fault Diagnosis of Demountable Disk-Drum Aero-Engine Rotor Using Customized Multiwavelet Method.

PubMed

Chen, Jinglong; Wang, Yu; He, Zhengjia; Wang, Xiaodong

2015-10-23

The demountable disk-drum aero-engine rotor is an important piece of equipment that greatly impacts the safe operation of aircraft. However, assembly looseness or crack fault has led to several unscheduled breakdowns and serious accidents. Thus, condition monitoring and fault diagnosis technique are required for identifying abnormal conditions. Customized ensemble multiwavelet method for aero-engine rotor condition identification, using measured vibration data, is developed in this paper. First, customized multiwavelet basis function with strong adaptivity is constructed via symmetric multiwavelet lifting scheme. Then vibration signal is processed by customized ensemble multiwavelet transform. Next, normalized information entropy of multiwavelet decomposition coefficients is computed to directly reflect and evaluate the condition. The proposed approach is first applied to fault detection of an experimental aero-engine rotor. Finally, the proposed approach is used in an engineering application, where it successfully identified the crack fault of a demountable disk-drum aero-engine rotor. The results show that the proposed method possesses excellent performance in fault detection of aero-engine rotor. Moreover, the robustness of the multiwavelet method against noise is also tested and verified by simulation and field experiments.

Autologous engineering of cartilage

PubMed Central

Emans, Pieter J.; van Rhijn, Lodewijk W.; Welting, Tim J. M.; Cremers, Andy; Wijnands, Nina; Spaapen, Frank; Voncken, J. Willem; Shastri, V. Prasad

2010-01-01

Treatment of full-thickness damage to hyaline cartilage is hampered by the limited availability of autologous healthy cartilage and the lengthy, cost-prohibitive cell isolation and expansion steps associated with autologous cartilage implantation (ACI). Here we report a strategy for de novo engineering of ectopic autologous cartilage (EAC) within the subperiosteal space (in vivo bioreactor), through the mere introduction of a biocompatible gel that might promote hypoxia-mediated chondrogenesis, thereby effectively overcoming the aforementioned limitations. The EAC is obtained within 3 wk post injection of the gel, and can be press-fit into an osteochondral defect where it undergoes remodeling with good lateral and subchondral integration. The implanted EAC showed no calcification even after 9 mo and attained an average O’Driscoll score of 11 (versus 4 for controls). An “on demand” autologous source of autologous cartilage with remodeling capacity is expected to significantly impact the clinical options in repair of trauma to articular cartilage. PMID:20133690

Transplantation of autologous endothelial progenitor cells in porous PLGA scaffolds create a microenvironment for the regeneration of hyaline cartilage in rabbits.

PubMed

Chang, N-J; Lam, C-F; Lin, C-C; Chen, W-L; Li, C-F; Lin, Y-T; Yeh, M-L

2013-10-01

Repairing articular cartilage is clinically challenging. We investigated a simple, effective and clinically feasible cell-based therapeutic approach using a poly(lactide-co-glycolide) (PLGA) scaffold seeded with autologous endothelial progenitor cells (EPC) to repair a full-thickness osteochondral defect in rabbits using a one-step surgery. EPC obtained by purifying a small amount of peripheral blood from rabbits were seeded into a highly porous, biocompatible PLGA scaffold, namely, EPC-PLGA, and implanted into the osteochondral defect in the medial femoral condyle. Twenty two rabbits were randomized into one of three groups: the empty defect group (ED), the PLGA-only group or the EPC-PLGA group. The defect sites were evaluated 4 and 12 weeks after implantation. At the end of testing, only the EPC-PLGA group showed the development of new cartilage tissue with a smooth, transparent and integrated articular surface. Moreover, histological analysis showed obvious differences in cartilage regeneration. At week 4, the EPC-PLGA group showed considerably higher TGF-β2 and TGF-β3 expression, a greater amount of synthesized glycosaminoglycan (GAG) content, and a higher degree of osteochondral angiogenesis in repaired tissues. At week 12, the EPC-PLGA group showed enhanced hyaline cartilage regeneration with a normal columnar chondrocyte arrangement, higher SOX9 expression, and greater GAG and collagen type II (COLII) content. Moreover, the EPC-PLGA group showed organized osteochondral integration, the formation of vessel-rich tubercular bone and significantly higher bone volume per tissue volume and trabecular thickness (Tb.Th). The present EPC-PLGA cell delivery system generates a suitable in situ microenvironment for osteochondral regeneration without the supplement of exogenous growth factors. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Undergraduate design projects for assistive technology needs: assisted fishing.

PubMed

Borrego, Nick; Bilan, Kristi; Gebes, T J; Barrett, S F; Morton, S A

2012-01-01

In 2010 the University of Wyoming, College of Engineering and Applied Science was funded for a five year increment of the National Science Foundation’s Research to Aid Persons with Disabilities. This program provides a vital link between challenged individuals who require custom assistive technology devices with senior capstone design students who require challenging, meaningful projects. The program also provides education for our next generation of engineers on the needs of all individuals. In this paper we describe the program organization including project partners in the College and Wyoming Institute for Disabilities (WIND). We also provide a case study of a recently completed project for an assistive fishing device.

Human Centered Hardware Modeling and Collaboration

NASA Technical Reports Server (NTRS)

Stambolian Damon; Lawrence, Brad; Stelges, Katrine; Henderson, Gena

2013-01-01

In order to collaborate engineering designs among NASA Centers and customers, to in clude hardware and human activities from multiple remote locations, live human-centered modeling and collaboration across several sites has been successfully facilitated by Kennedy Space Center. The focus of this paper includes innovative a pproaches to engineering design analyses and training, along with research being conducted to apply new technologies for tracking, immersing, and evaluating humans as well as rocket, vehic le, component, or faci lity hardware utilizing high resolution cameras, motion tracking, ergonomic analysis, biomedical monitoring, wor k instruction integration, head-mounted displays, and other innovative human-system integration modeling, simulation, and collaboration applications.

User engineering: A new look at system engineering

NASA Technical Reports Server (NTRS)

Mclaughlin, Larry L.

1987-01-01

User Engineering is a new System Engineering perspective responsible for defining and maintaining the user view of the system. Its elements are a process to guide the project and customer, a multidisciplinary team including hard and soft sciences, rapid prototyping tools to build user interfaces quickly and modify them frequently at low cost, and a prototyping center for involving users and designers in an iterative way. The main consideration is reducing the risk that the end user will not or cannot effectively use the system. The process begins with user analysis to produce cognitive and work style models, and task analysis to produce user work functions and scenarios. These become major drivers of the human computer interface design which is presented and reviewed as an interactive prototype by users. Feedback is rapid and productive, and user effectiveness can be measured and observed before the system is built and fielded. Requirements are derived via the prototype and baselined early to serve as an input to the architecture and software design.

Proposed Facility Modifications to Support Propulsion Systems Testing Under Simulated Space Conditions at Plum Brook Station's Spacecraft Propulsion Research Facility (B-2)

NASA Technical Reports Server (NTRS)

Edwards, Daryl A.

2008-01-01

Preparing NASA's Plum Brook Station's Spacecraft Propulsion Research Facility (B-2) to support NASA's new generation of launch vehicles has raised many challenges for B-2's support staff. The facility provides a unique capability to test chemical propulsion systems/vehicles while simulating space thermal and vacuum environments. Designed and constructed in the early 1960s to support upper stage cryogenic engine/vehicle system development, the Plum Brook Station B-2 facility will require modifications to support the larger, more powerful, and more advanced engine systems for the next generation of vehicles leaving earth's orbit. Engine design improvements over the years have included large area expansion ratio nozzles, greater combustion chamber pressures, and advanced materials. Consequently, it has become necessary to determine what facility changes are required and how the facility can be adapted to support varying customers and their specific test needs. Exhaust system performance, including understanding the present facility capabilities, is the primary focus of this work. A variety of approaches and analytical tools are being employed to gain this understanding. This presentation discusses some of the challenges in applying these tools to this project and expected facility configuration to support the varying customer needs.

Proposed Facility Modifications to Support Propulsion Systems Testing Under Simulated Space Conditions at Plum Brook Station's Spacecraft Propulsion Research Facility (B-2)

NASA Technical Reports Server (NTRS)

Edwards, Daryl A.

2007-01-01

Preparing NASA's Plum Brook Station's Spacecraft Propulsion Research Facility (B-2) to support NASA's new generation of launch vehicles has raised many challenges for B-2 s support staff. The facility provides a unique capability to test chemical propulsion systems/vehicles while simulating space thermal and vacuum environments. Designed and constructed 4 decades ago to support upper stage cryogenic engine/vehicle system development, the Plum Brook Station B-2 facility will require modifications to support the larger, more powerful, and more advanced engine systems for the next generation of vehicles leaving earth's orbit. Engine design improvements over the years have included large area expansion ratio nozzles, greater combustion chamber pressures, and advanced materials. Consequently, it has become necessary to determine what facility changes are required and how the facility can be adapted to support varying customers and their specific test needs. Instrumental in this task is understanding the present facility capabilities and identifying what reasonable changes can be implemented. A variety of approaches and analytical tools are being employed to gain this understanding. This paper discusses some of the challenges in applying these tools to this project and expected facility configuration to support the varying customer needs.

A novel double-network hydrogel induces spontaneous articular cartilage regeneration in vivo in a large osteochondral defect.

PubMed

Yasuda, Kazunori; Kitamura, Nobuto; Gong, Jian Ping; Arakaki, Kazunobu; Kwon, Hyuck Joon; Onodera, Shin; Chen, Yong Mei; Kurokawa, Takayuki; Kanaya, Fuminori; Ohmiya, Yoshihiro; Osada, Yoshihito

2009-04-08

We have developed a novel method to induce spontaneous hyaline cartilage regeneration in vivo for a large osteochondral defect by implanting a plug made from a double-network hydrogel composed of poly(2-acrylamido-2-methylpropanesulfonic acid) and poly(N,N'-dimethylacrylamide) at the bottom of the defect, leaving the cavity vacant. In cells regenerated in the treated defect, type-2 collagen, Aggrican, and SOX9 mRNAs were highly expressed and the regenerated matrix was rich in proteoglycan and type-2 collagen at 4 weeks. This fact gave a significant modification to the commonly established concept that hyaline cartilage tissue cannot regenerate in vivo. This study prompted an innovative strategy in the field of joint surgery to repair an osteochondral defect using an advanced, high-function hydrogel.

ARCADIA{sup R} - A New Generation of Coupled Neutronics / Core Thermal- Hydraulics Code System at AREVA NP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curca-Tivig, Florin; Merk, Stephan; Pautz, Andreas

2007-07-01

Anticipating future needs of our customers and willing to concentrate synergies and competences existing in the company for the benefit of our customers, AREVA NP decided in 2002 to develop the next generation of coupled neutronics/ core thermal-hydraulic (TH) code systems for fuel assembly and core design calculations for both, PWR and BWR applications. The global CONVERGENCE project was born: after a feasibility study of one year (2002) and a conceptual phase of another year (2003), development was started at the beginning of 2004. The present paper introduces the CONVERGENCE project, presents the main feature of the new code systemmore » ARCADIA{sup R} and concludes on customer benefits. ARCADIA{sup R} is designed to meet AREVA NP market and customers' requirements worldwide. Besides state-of-the-art physical modeling, numerical performance and industrial functionality, the ARCADIA{sup R} system is featuring state-of-the-art software engineering. The new code system will bring a series of benefits for our customers: e.g. improved accuracy for heterogeneous cores (MOX/ UOX, Gd...), better description of nuclide chains, and access to local neutronics/ thermal-hydraulics and possibly thermal-mechanical information (3D pin by pin full core modeling). ARCADIA is a registered trademark of AREVA NP. (authors)« less

Rationally designed synthetic protein hydrogels with predictable mechanical properties.

PubMed

Wu, Junhua; Li, Pengfei; Dong, Chenling; Jiang, Heting; Bin Xue; Gao, Xiang; Qin, Meng; Wang, Wei; Bin Chen; Cao, Yi

2018-02-12

Designing synthetic protein hydrogels with tailored mechanical properties similar to naturally occurring tissues is an eternal pursuit in tissue engineering and stem cell and cancer research. However, it remains challenging to correlate the mechanical properties of protein hydrogels with the nanomechanics of individual building blocks. Here we use single-molecule force spectroscopy, protein engineering and theoretical modeling to prove that the mechanical properties of protein hydrogels are predictable based on the mechanical hierarchy of the cross-linkers and the load-bearing modules at the molecular level. These findings provide a framework for rationally designing protein hydrogels with independently tunable elasticity, extensibility, toughness and self-healing. Using this principle, we demonstrate the engineering of self-healable muscle-mimicking hydrogels that can significantly dissipate energy through protein unfolding. We expect that this principle can be generalized for the construction of protein hydrogels with customized mechanical properties for biomedical applications.

Modular Biopower System Providing Combined Heat and Power for DoD Installations

DTIC Science & Technology

2013-12-01

Cycle Cost evaluation using the experimental results of the 6-month field demonstration and the system’s projected cost and performance for the...34 5.6 SAMPLING RESULTS ...premises, which resulted in a significant program delay. After a short period of operation, the custom-designed engine developed mechanical

Percutaneous CT-Guided Treatment of Osteochondritis Dissecans of the Sacroiliac Joint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becce, Fabio, E-mail: fabio.becce@chuv.ch; Mouhsine, Elyazid; Mosimann, Pascal John

2012-08-15

Osteochondritis dissecans (OCD) is a joint disorder that affects the articular cartilage and subchondral bone, most commonly at the knee. OCD of the sacroiliac joint is extremely rare. Management of OCD remains controversial, and surgery is often needed, especially when conservative treatment fails. We present a rare case of OCD involving the left sacroiliac joint successfully treated by percutaneous computed tomography-guided retrograde drilling and debridement.

Knee salvage procedures: The indications, techniques and outcomes of large osteochondral allografts

PubMed Central

Chui, Karen; Jeys, Lee; Snow, Martyn

2015-01-01

The overall incidence of osteochondral defect in the general population is estimated to be 15 to 30 per 100000 people. These lesions can become symptomatic causing pain, swelling and decreased function of the knee, and may eventually progress to osteoarthritis. In the young and active population, partial or total knee arthroplasty (TKA) is rarely the treatment of choice due to risk of early failure. Osteochondral allograft transplantation has been demonstrated to be a safe and effective treatment of large osteochondral and chondral defects of the knee in appropriately selected patients. The treatment reduces pain, improves function and is a viable limb salvage procedure for patients, especially young and active patients for whom TKA is not recommended. Either large dowels generated with commercially available equipment or free hand shell allografts can be implanted in more posterior lesions. Current recommendations for fresh allografts stored at 4C advise implantation within 21-28 d of procurement for optimum chondrocyte viability, following screening and testing protocols. Higher rates of successful allograft transplantation are observed in younger patients, unipolar lesions, normal or corrected malalignment, and defects that are treated within 12 mo of symptom onset. Patients with bipolar lesions, uncorrectable malalignment, advanced osteoarthritis, and those over 40 tend to have less favourable outcomes. PMID:25893177

The 2015-2016 SEPMAP Program at NASA JSC: Science, Engineering, and Program Management Training

NASA Technical Reports Server (NTRS)

Graham, L.; Archer, D.; Bakalyar, J.; Berger, E.; Blome, E.; Brown, R.; Cox, S.; Curiel, P.; Eid, R.; Eppler, D.;

Social norms of "good" design: Interdisciplinary perspectives from a survey of engineers and clinicians in bioengineering.

PubMed

Johnson, Angela N

2016-08-01

In bioengineering training for new researchers and engineers, a great deal of time is spent discussing what constitutes "good" design. Conceptualization of good design, however, varies widely across interdisciplinary team members, with potential to both foster innovation or lead to unproductive conflict. To explore how groups central to bioengineering teams (physicians/clinicians and engineers/physicists) conceptualize good design, we asked 176 professionals in bioengineering to complete a comprehensive online survey including items designed to assess cognitive and moral foundations (validated MFQ30 tool) and custom items assessing perceptions on good design in three areas (good design characteristics, reputation of design approvers, and perceived design patient/consumer suitability). Of those that responded, 82 completed all quantitative survey sections and were included in this preliminary analysis. Correlations between response areas were examined to explore the possible links between cognitive and moral biases and perspectives on good design. The survey results indicated that both groups were more conservative than average Americans based on previous reports, and clinicians scored higher on average for all MFQ30 domains. Numerous significant correlations with good design were observed among clinicians, while engineers/physicists most closely correlated good design with prescriber approval and scientific/technical literature. The exploratory analysis demonstrated the potential utility of sociological frameworks to explore relationships in design thinking with potential utility to stimulate thriving conversation on team-based design thinking in bioengineering education and practice.

Space Transportation System Availability Requirement and Its Influencing Attributes Relationships

NASA Technical Reports Server (NTRS)

Rhodes, Russell E.; Adams, Timothy C.; McCleskey, Carey M.

2008-01-01

It is important that engineering and management accept the need for an availability requirement that is derived with its influencing attributes. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability. Also important to provide bounds of the variables providing engineering the insight required to control the system's engineering solution, e.g., these influencing attributes become design requirements also. These variables will drive the need to provide integration of similar discipline functions or technology selection to allow control of the total parts count. The relationship of selecting a reliability requirement will place a constraint on parts count to achieve a given availability requirement or if allowed to increase the parts count will drive the system reliability requirement higher. They also provide the understanding for the relationship of mean repair time (or mean down time) to maintainability, e.g., accessibility for repair, and both the mean time between failure, e.g., reliability of hardware and availability. The concerns and importance of achieving a strong availability requirement is driven by the need for affordability, the choice of using the two launch solution for the single space application, or the need to control the spare parts count needed to support the long stay in either orbit or on the surface of the moon. Understanding the requirements before starting the architectural design concept will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable increased life cycle cost of the fielded space transportation system.

Space Transportation System Availability Requirements and Its Influencing Attributes Relationships

NASA Technical Reports Server (NTRS)

Rhodes, Russell E.; Adams, Timothy C.; McCleskey, Carey M.

2008-01-01

It is important that engineering and management accept the need for an availability requirement that is derived with its influencing attributes. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability. Also important to provide bounds of the variables providing engineering the insight required to control the system's engineering solution, e.g., these influencing attributes become design requirements also. These variables will drive the need to provide integration of similar discipline functions or technology selection to allow control of the total parts count. The relationship of selecting a reliability requirement will place a constraint on parts count to achieve a given availability requirement or if allowed to increase the parts count will drive the system reliability requirement higher. They also provide the understanding for the relationship of mean repair time (or mean down time) to maintainability, e.g., accessibility for repair, and both the mean time between failure, e.g., reliability of hardware and availability. The concerns and importance of achieving a strong availability requirement is driven by the need for affordability, the choice of using the two launch solution for the single space application, or the need to control the spare parts count needed to support the long stay in either orbit or on the surface of the moon. Understanding the requirements before starting the architectural design concept will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable increased life cycle cost of the fielded space transportation system.

U.S. Army Corps of Engineers: Building Overhead Costs into Projects and Customers’ Views on Information Provided

DTIC Science & Technology

2013-06-01

U.S. ARMY CORPS OF ENGINEERS Building Overhead Costs into Projects and Customers ’ Views on Information Provided...Overhead Costs into Projects and Customers ’ Views on Information Provided 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...and Customers ’ Views on Information Provided Why GAO Did This Study The Corps spends billions of dollars annually on projects in its Civil Works

Additive Manufacture of Plasma Diagnostic Components Final Report Phase II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodruff, Simon; Romero-Talamas, Carlos; You, Setthivoine

There is now a well-established set of plasma diagnostics (see e.g. [3]), but these remain some of the mostexpensive assemblies in fusion systems since for every system they have to be custom built, and time fordiagnostic development can pace the project. Additive manufacturing (AM) has the potential to decreaseproduction cost and significantly lower design time of fusion diagnostic subsystems, which would realizesignificant cost reduction for standard diagnostics. In some cases, these basic components can be additivelymanufactured for less than 1/100th costs of conventional manufacturing.In our DOE Phase II SBIR, we examined the impact that AM can have on plasma diagnosticmore » cost bytaking 15 separate diagnostics through an engineering design using Conventional Manufacturing (CM) tech-niques, then optimizing the design to exploit the benefits of AM. The impact of AM techniques on cost isfound to be in several areas. First, the cost of materials falls because AM parts can be manufactured withlittle to no waste, and engineered to use less material than CM. Next, the cost of fabrication falls for AMparts relative to CM since the fabrication time can be computed exactly, and often no post-processing isrequired for the part to be functional. We find that AM techniques are well suited for plasma diagnosticssince typical diagnostic complexity comes at no additional cost. Cooling channels, for example, can be builtin to plasma-facing components at no extra cost. Fabrication costs associated with assembly are lower forAM parts because many components can be combined and printed as monoliths, thereby mitigating the needfor alignment or calibration. Finally, the cost of engineering is impacted by exploiting AM design tools thatallow standard components to be customized through web-interfaces. Furthermore, we find that conceptdesign costs can be impacted by scripting interfaces for online engineering design tools.« less

Incorporating Servqual-QFD with Taguchi Design for optimizing service quality design

NASA Astrophysics Data System (ADS)

Arbi Hadiyat, M.

2018-03-01

Deploying good service design in service companies has been updated issue in improving customer satisfaction, especially based on the level of service quality measured by Parasuraman’s SERVQUAL. Many researchers have been proposing methods in designing the service, and some of them are based on engineering viewpoint, especially by implementing the QFD method or even using robust Taguchi method. The QFD method would found the qualitative solution by generating the “how’s”, while Taguchi method gives more quantitative calculation in optimizing best solution. However, incorporating both QFD and Taguchi has been done in this paper and yields better design process. The purposes of this research is to evaluate the incorporated methods by implemented it to a case study, then analyze the result and see the robustness of those methods to customer perception of service quality. Started by measuring service attributes using SERVQUAL and find the improvement with QFD, the deployment of QFD solution then generated by defining Taguchi factors levels and calculating the Signal-to-noise ratio in its orthogonal array, and optimized Taguchi response then found. A case study was given for designing service in local bank. Afterward, the service design obtained from previous analysis was then evaluated and shows that it was still meet the customer satisfaction. Incorporating QFD and Taguchi has performed well and can be adopted and developed for another research for evaluating the robustness of result.

Computer-aided design of biological circuits using TinkerCell

PubMed Central

Bergmann, Frank T; Sauro, Herbert M

2010-01-01

Synthetic biology is an engineering discipline that builds on modeling practices from systems biology and wet-lab techniques from genetic engineering. As synthetic biology advances, efficient procedures will be developed that will allow a synthetic biologist to design, analyze and build biological networks. In this idealized pipeline, computer-aided design (CAD) is a necessary component. The role of a CAD application would be to allow efficient transition from a general design to a final product. TinkerCell is a design tool for serving this purpose in synthetic biology. In TinkerCell, users build biological networks using biological parts and modules. The network can be analyzed using one of several functions provided by TinkerCell or custom programs from third-party sources. Since best practices for modeling and constructing synthetic biology networks have not yet been established, TinkerCell is designed as a flexible and extensible application that can adjust itself to changes in the field. PMID:21327060

A Discussion of the Software Quality Assurance Role

NASA Technical Reports Server (NTRS)

Kandt, Ronald Kirk

2010-01-01

The basic idea underlying this paper is that the conventional understanding of the role of a Software Quality Assurance (SQA) engineer is unduly limited. This is because few have asked who the customers of a SQA engineer are. Once you do this, you can better define what tasks a SQA engineer should perform, as well as identify the knowledge and skills that such a person should have. The consequence of doing this is that a SQA engineer can provide greater value to his or her customers. It is the position of this paper that a SQA engineer providing significant value to his or her customers must not only assume the role of an auditor, but also that of a software and systems engineer. This is because software engineers and their managers particularly value contributions that directly impact products and their development. These ideas are summarized as lessons learned, based on my experience at Jet Propulsion Laboratory (JPL).

Treatment of Knee Osteochondral Lesions Using a Novel Clot of Autologous Plasma Rich in Growth Factors Mixed with Healthy Hyaline Cartilage Chips and Intra-Articular Injection of PRGF

PubMed Central

Alentorn-Geli, Eduard; Steinbacher, Gilbert; Álvarez-Díaz, Pedro; Cuscó, Xavier; Seijas, Roberto; Barastegui, David; Navarro, Jordi; Laiz, Patricia; García-Balletbó, Montserrat

2017-01-01

Knee cartilage or osteochondral lesions are common and challenging injuries. To date, most symptomatic lesions warrant surgical treatment. We present two cases of patients with knee osteochondral defects treated with a one-step surgical procedure consisting of an autologous-based matrix composed of healthy hyaline cartilage chips, mixed plasma poor-rich in platelets clot, and plasma rich in growth factors (PRGF). Both patients returned to playing soccer at the preinjury activity level and demonstrated excellent defect filling in both magnetic resonance imaging and second-look arthroscopy (in one of them). The use of a clot of autologous plasma poor in platelets with healthy hyaline cartilage chips and intra-articular injection of plasma rich in platelets is an effective, easy, and cheap option to treat knee cartilage injuries in young and athletic patients. PMID:28798878

Steroid-induced femoral head osteonecrosis in immune thrombocytopenia treatment with osteochondral autograft transplantation.

PubMed

Fotopoulos, Vasileios Ch; Mouzopoulos, George; Floros, Themistoklis; Tzurbakis, Matthaios

2015-09-01

Osteonecrosis of the femoral head is a devastating complication of steroid administration and has rarely been observed in the treatment of immune thrombocytopenia. The treatment of osteochondral defects in advanced stages of avascular necrosis (AVN), characterized by collapse of the subchondral bone, remains an unsolved burden in orthopedic surgery. In this report, we present a case of a 19-year-old female that was admitted in the Emergency Department with walking disability and painful hip joint movement due to steroid-induced femoral head osteonecrosis. Two years before she was diagnosed with immune thrombocytopenia, for which she received pulse steroid therapy with high dose of dexamethasone and underwent a splenectomy. This case report is the first to describe the use of osteochondral autograft transplantation as a treatment of steroid-induced AVN of the femoral head due to immune thrombocytopenia at the age of 19 years with very good clinical and radiological results 3 years postoperatively.

Treatment of Knee Osteochondral Lesions Using a Novel Clot of Autologous Plasma Rich in Growth Factors Mixed with Healthy Hyaline Cartilage Chips and Intra-Articular Injection of PRGF.

PubMed

Cugat, Ramón; Alentorn-Geli, Eduard; Steinbacher, Gilbert; Álvarez-Díaz, Pedro; Cuscó, Xavier; Seijas, Roberto; Barastegui, David; Navarro, Jordi; Laiz, Patricia; García-Balletbó, Montserrat

2017-01-01

Knee cartilage or osteochondral lesions are common and challenging injuries. To date, most symptomatic lesions warrant surgical treatment. We present two cases of patients with knee osteochondral defects treated with a one-step surgical procedure consisting of an autologous-based matrix composed of healthy hyaline cartilage chips, mixed plasma poor-rich in platelets clot, and plasma rich in growth factors (PRGF). Both patients returned to playing soccer at the preinjury activity level and demonstrated excellent defect filling in both magnetic resonance imaging and second-look arthroscopy (in one of them). The use of a clot of autologous plasma poor in platelets with healthy hyaline cartilage chips and intra-articular injection of plasma rich in platelets is an effective, easy, and cheap option to treat knee cartilage injuries in young and athletic patients.

Fault Diagnosis of Demountable Disk-Drum Aero-Engine Rotor Using Customized Multiwavelet Method

PubMed Central

Chen, Jinglong; Wang, Yu; He, Zhengjia; Wang, Xiaodong

2015-01-01

The demountable disk-drum aero-engine rotor is an important piece of equipment that greatly impacts the safe operation of aircraft. However, assembly looseness or crack fault has led to several unscheduled breakdowns and serious accidents. Thus, condition monitoring and fault diagnosis technique are required for identifying abnormal conditions. Customized ensemble multiwavelet method for aero-engine rotor condition identification, using measured vibration data, is developed in this paper. First, customized multiwavelet basis function with strong adaptivity is constructed via symmetric multiwavelet lifting scheme. Then vibration signal is processed by customized ensemble multiwavelet transform. Next, normalized information entropy of multiwavelet decomposition coefficients is computed to directly reflect and evaluate the condition. The proposed approach is first applied to fault detection of an experimental aero-engine rotor. Finally, the proposed approach is used in an engineering application, where it successfully identified the crack fault of a demountable disk-drum aero-engine rotor. The results show that the proposed method possesses excellent performance in fault detection of aero-engine rotor. Moreover, the robustness of the multiwavelet method against noise is also tested and verified by simulation and field experiments. PMID:26512668

A Study of Technical Engineering Peer Reviews at NASA

NASA Technical Reports Server (NTRS)

Chao, Lawrence P.; Tumer, Irem Y.; Bell, David G.

2003-01-01

This report describes the state of practices of design reviews at NASA and research into what can be done to improve peer review practices. There are many types of reviews at NASA: required and not, formalized and informal, programmatic and technical. Standing project formal reviews such as the Preliminary Design Review and Critical Design Review are a required part of every project and mission development. However, the technical, engineering peer reviews that support teams' work on such projects are informal, some times ad hoc, and inconsistent across the organization. The goal of this work is to identify best practices and lessons learned from NASA's experience, supported by academic research and methodologies to ultimately improve the process. This research has determined that the organization, composition, scope, and approach of the reviews impact their success. Failure Modes and Effects Analysis (FMEA) can identify key areas of concern before or in the reviews. Product definition tools like the Project Priority Matrix, engineering-focused Customer Value Chain Analysis (CVCA), and project or system-based Quality Function Deployment (QFD) help prioritize resources in reviews. The use of information technology and structured design methodologies can strengthen the engineering peer review process to help NASA work towards error-proofing the design process.

Organ Printing

NASA Astrophysics Data System (ADS)

Cho, Dong-Woo; Lee, Jung-Seob; Jang, Jinah; Jung, Jin Woo; Park, Jeong Hun; Pati, Falguni

2015-10-01

This book introduces various 3D printing systems, biomaterials, and cells for organ printing. In view of the latest applications of several 3D printing systems, their advantages and disadvantages are also discussed. A basic understanding of the entire spectrum of organ printing provides pragmatic insight into the mechanisms, methods, and applications of this discipline. Organ printing is being applied in the tissue engineering field with the purpose of developing tissue/organ constructs for the regeneration of both hard (bone, cartilage, osteochondral) and soft tissues (heart). There are other potential application areas including tissue/organ models, disease/cancer models, and models for physiology and pathology, where in vitro 3D multicellular structures developed by organ printing are valuable.

Customizing the JPL Multimission Ground Data System: Lessons learned

NASA Technical Reports Server (NTRS)

Murphy, Susan C.; Louie, John J.; Guerrero, Ana Maria; Hurley, Daniel; Flora-Adams, Dana

1994-01-01

The Multimission Ground Data System (MGDS) at NASA's Jet Propulsion Laboratory has brought improvements and new technologies to mission operations. It was designed as a generic data system to meet the needs of multiple missions and avoid re-inventing capabilities for each new mission and thus reduce costs. It is based on adaptable tools that can be customized to support different missions and operations scenarios. The MGDS is based on a distributed client/server architecture, with powerful Unix workstations, incorporating standards and open system architectures. The distributed architecture allows remote operations and user science data exchange, while also providing capabilities for centralized ground system monitor and control. The MGDS has proved its capabilities in supporting multiple large-class missions simultaneously, including the Voyager, Galileo, Magellan, Ulysses, and Mars Observer missions. The Operations Engineering Lab (OEL) at JPL has been leading Customer Adaptation Training (CAT) teams for adapting and customizing MGDS for the various operations and engineering teams. These CAT teams have typically consisted of only a few engineers who are familiar with operations and with the MGDS software and architecture. Our experience has provided a unique opportunity to work directly with the spacecraft and instrument operations teams and understand their requirements and how the MGDS can be adapted and customized to minimize their operations costs. As part of this work, we have developed workstation configurations, automation tools, and integrated user interfaces at minimal cost that have significantly improved productivity. We have also proved that these customized data systems are most successful if they are focused on the people and the tasks they perform and if they are based upon user confidence in the development team resulting from daily interactions. This paper will describe lessons learned in adapting JPL's MGDS to fly the Voyager, Galileo, and Mars Observer missions. We will explain how powerful, existing ground data systems can be adapted and packaged in a cost effective way for operations of small and large planetary missions. We will also describe how the MGDS was adapted to support operations within the Galileo Spacecraft Testbed. The Galileo testbed provided a unique opportunity to adapt MGDS to support command and control operations for a small autonomous operations team of a handful of engineers flying the Galileo Spacecraft flight system model.

Virtual Collaborative Environments for System of Systems Engineering and Applications for ISAT

NASA Technical Reports Server (NTRS)

Dryer, David A.

2002-01-01

This paper describes an system of systems or metasystems approach and models developed to help prepare engineering organizations for distributed engineering environments. These changes in engineering enterprises include competition in increasingly global environments; new partnering opportunities caused by advances in information and communication technologies, and virtual collaboration issues associated with dispersed teams. To help address challenges and needs in this environment, a framework is proposed that can be customized and adapted for NASA to assist in improved engineering activities conducted in distributed, enhanced engineering environments. The approach is designed to prepare engineers for such distributed collaborative environments by learning and applying e-engineering methods and tools to a real-world engineering development scenario. The approach consists of two phases: an e-engineering basics phase and e-engineering application phase. The e-engineering basics phase addresses skills required for e-engineering. The e-engineering application phase applies these skills in a distributed collaborative environment to system development projects.

Selling Internet Gambling: Advertising, New Media and the Content of Poker Promotion

ERIC Educational Resources Information Center

McMullan, John L.; Kervin, Melissa

2012-01-01

This study examines the web design and engineering, advertising and marketing, and pedagogical features present at a random sample of 71 international poker sites obtained from the Casino City directory in the summer of 2009. We coded for 22 variables related to access, appeal, player protection, customer services, on-site security, use of images,…

Through a Different Lens: Bridging the Expectation-Perception (Quality) Divide in Higher Education

ERIC Educational Resources Information Center

Yeo, Roland K.; Marquardt, Michael J.

2011-01-01

The paper draws on the underpinnings of SERVQUAL (a Service Quality measurement model) and explores three key aspects of service standards as adopted by an Engineering School in Singapore: customer orientation, course design/delivery and support services. Qualitative methodology was employed and data were collected by means of structured in-depth…

19 CFR 10.178 - Direct costs of processing operations performed in the beneficiary developing country.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., design, engineering, and blueprint costs insofar as they are allocable to the specific merchandise; and... 19 Customs Duties 1 2013-04-01 2013-04-01 false Direct costs of processing operations performed in... TO A REDUCED RATE, ETC. General Provisions Generalized System of Preferences § 10.178 Direct costs of...

19 CFR 10.178 - Direct costs of processing operations performed in the beneficiary developing country.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., design, engineering, and blueprint costs insofar as they are allocable to the specific merchandise; and... 19 Customs Duties 1 2014-04-01 2014-04-01 false Direct costs of processing operations performed in... TO A REDUCED RATE, ETC. General Provisions Generalized System of Preferences § 10.178 Direct costs of...

19 CFR 10.178 - Direct costs of processing operations performed in the beneficiary developing country.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., design, engineering, and blueprint costs insofar as they are allocable to the specific merchandise; and... 19 Customs Duties 1 2012-04-01 2012-04-01 false Direct costs of processing operations performed in... TO A REDUCED RATE, ETC. General Provisions Generalized System of Preferences § 10.178 Direct costs of...

77 FR 51067 - Investigations Regarding Eligibility To Apply for Worker Adjustment Assistance

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-23

.... Brockport, PA...... 08/06/12 08/03/12 (Union). 81863 Industrial Machine & Farmington, MO..... 08/07/12 08/07... Industrial Sales (Workers). 81865 Sihi Pumps (Workers).... Grand Island, NY... 08/07/12 07/31/12 81866 Acme... Custom Technology, Windsor, CT........ 08/09/12 08/09/12 Inc., Engineering Design and Drafting Department...

Implantation of Autologous Cartilage Chips Improves Cartilage Repair Tissue Quality in Osteochondral Defects: A Study in Göttingen Minipigs.

PubMed

Christensen, Bjørn Borsøe; Foldager, Casper Bindzus; Olesen, Morten Lykke; Hede, Kris Chadwick; Lind, Martin

2016-06-01

Osteochondral injuries have poor endogenous healing potential, and no standard treatment has been established. The use of combined layered autologous bone and cartilage chips for treatment of osteochondral defects has shown promising short-term clinical results. This study aimed to investigate the role of cartilage chips by comparing combined layered autologous bone and cartilage chips with autologous bone implantation alone in a Göttingen minipig model. The hypothesis was that the presence of cartilage chips would improve the quality of the repair tissue. Controlled laboratory study. Twelve Göttingen minipigs received 2 osteochondral defects in each knee. The defects were randomized to autologous bone graft (ABG) combined with autologous cartilage chips (autologous dual-tissue transplantation [ADTT]) or ABG alone. Six animals were euthanized at 6 months and 6 animals were euthanized at 12 months. Follow-up evaluation consisted of histomorphometry, immunohistochemistry, semiquantitative scoring (International Cartilage Repair Society II), and computed tomography. There was significantly more hyaline cartilage in the ADTT group (25.8%) compared with the ABG group (12.8%) at 6 months after treatment. At 12 months, the fraction of hyaline cartilage in the ABG group had significantly decreased to 4.8%, whereas the fraction of hyaline cartilage in the ADTT group was unchanged (20.1%). At 6 and 12 months, there was significantly more fibrocartilage in the ADTT group (44% and 60.8%) compared with the ABG group (24.5% and 41%). The fraction of fibrous tissue was significantly lower in the ADTT group compared with the ABG group at both 6 and 12 months. The implanted cartilage chips stained >75% positive for collagen type 4 and laminin at both 6 and 12 months. Significant differences were found in a number of International Cartilage Repair Society II subcategories. The volume of the remaining bone defect significantly decreased from 6 to 12 months in both treatment groups; however, no difference in volume was found between the groups at either 6 or 12 months. The presence of cartilage chips in an osteochondral defect facilitated the formation of fibrocartilage as opposed to fibrous tissue at both 6 and 12 months posttreatment. The implanted chips were present in the defect and viable after 12 months. This study substantiates the chondrogenic role of cartilage chips in osteochondral defects. © 2016 The Author(s).

Electrical stimulation systems for cardiac tissue engineering

PubMed Central

Tandon, Nina; Cannizzaro, Christopher; Chao, Pen-Hsiu Grace; Maidhof, Robert; Marsano, Anna; Au, Hoi Ting Heidi; Radisic, Milica; Vunjak-Novakovic, Gordana

2009-01-01

We describe a protocol for tissue engineering of synchronously contractile cardiac constructs by culturing cardiac cells with the application of pulsatile electrical fields designed to mimic those present in the native heart. Tissue culture is conducted in a customized chamber built to allow for cultivation of (i) engineered three-dimensional (3D) cardiac tissue constructs, (ii) cell monolayers on flat substrates or (iii) cells on patterned substrates. This also allows for analysis of the individual and interactive effects of pulsatile electrical field stimulation and substrate topography on cell differentiation and assembly. The protocol is designed to allow for delivery of predictable electrical field stimuli to cells, monitoring environmental parameters, and assessment of cell and tissue responses. The duration of the protocol is 5 d for two-dimensional cultures and 10 d for 3D cultures. PMID:19180087

Fresh-Stored Osteochondral Allograft for Treatment of Osteochondritis Dissecans the Femoral Head

DTIC Science & Technology

2010-01-01

rotational osteotomy for treatment of avascular necrosis of the femoral head. Arch Orthop Trauma Surg. 1996;115:80–84. Volume 468, Number 2, February 2010...14. Hall FM. Osteochondrosis dissecans and avascular necrosis of bone. (Comment on: Skeletal Radiol. 1990;19(6):419–421.) Skeletal Radiol. 1991;20...439–456. 28. Schneider W, Aigner N, Pinggera O, Knahr K. Intertrochanteric osteotomy for avascular necrosis of the head of the femur: sur- vival

Cryopreserved and frozen hyaline cartilage imaged by environmental scanning electron microscope. An experimental and prospective study.

PubMed

Sastre, Sergi; Suso, Santiago; Segur, Josep-Maria; Bori, Guillem; Carbonell, José-Antonio; Agustí, Elba; Nuñez, Montse

2008-08-01

To obtain images of the articular surface of osteochondral grafts (fresh, frozen, and cryopreserved in RPMI) using an environmental scanning electron microscope (ESEM). To evaluate and compare the main morphological aspects of the chondral surface of the fresh, frozen, and cryopreserved grafts as visualized via ESEM. The study was based on osteochondral fragments from the internal condyle of the knee joint of New Zealand rabbits, corresponding to the chondral surface from fresh, frozen, and cryopreserved samples. One hundred ESEM images were obtained from each group and then classified according to a validated system. The kappa index and the corresponding concordance index were calculated, and the groups were compared by Pearson's chi-squared test (p < 0.05). The articular surface of cryopreserved osteochondral grafts had fewer even surfaces and filled lacunae and a higher number of empty lacunae as compared to fresh samples; these differences correspond to images of cell membrane lesions that lead to destruction of the chondrocyte. Frozen grafts showed more hillocky and knobby surfaces than did fresh grafts; they also had a greater number of empty chondrocyte lacunae. ESEM is useful for obtaining images of the surface of osteochondral grafts. When compared to fresh samples, cryopreservation in RPMI medium produces changes in the surface of hyaline cartilage, but to a lesser extent than those produced by freezing.

Combination therapy with intra-articular injection of mesenchymal stem cells and articulated joint distraction for repair of a chronic osteochondral defect in the rabbit.

PubMed

Harada, Yohei; Nakasa, Tomoyuki; Mahmoud, Elhussein Elbadry; Kamei, Goki; Adachi, Nobuo; Deie, Masataka; Ochi, Mitsuo

2015-10-01

The present study investigated intra-articular injection of bone-marrow-derived mesenchymal stem cells (MSCs) combined with articulated joint distraction as treatment for osteochondral defects. Large osteochondral defects were created in the weight-bearing area of the medial femoral condyle in rabbit knees. Four weeks after defect creation, rabbits were divided into six groups: control group, MSC group, distraction group, distraction + MSC group, temporary distraction group, and temporary distraction + MSC group. Groups with MSC received intra-articular injection of MSCs. Groups with distraction underwent articulated distraction arthroplasty. Groups with temporary distraction discontinued the distraction after 4 weeks. The rabbits were euthanized at 4, 8, and 12 weeks after treatment except temporary distraction groups which were euthanized at only 12 weeks. Histological scores in the distraction + MSC group were significantly better than in the control, MSC group or distraction group at 4 and 8 weeks, but showed no further improvement. At 12 weeks, the temporary distraction + MSC group showed the best results, demonstrating hyaline cartilage repair with regeneration of the osteochondral junction. In conclusion, joint distraction with intra-articular injection of MSCs promotes early cartilage repair, and compressive loading of the repair tissue after temporary distraction stimulates articular cartilage regeneration. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Laser-Etched Designs for Molding Hydrogel-Based Engineered Tissues

PubMed Central

Munarin, Fabiola; Kaiser, Nicholas J.; Kim, Tae Yun; Choi, Bum-Rak

2017-01-01

Rapid prototyping and fabrication of elastomeric molds for sterile culture of engineered tissues allow for the development of tissue geometries that can be tailored to different in vitro applications and customized as implantable scaffolds for regenerative medicine. Commercially available molds offer minimal capabilities for adaptation to unique conditions or applications versus those for which they are specifically designed. Here we describe a replica molding method for the design and fabrication of poly(dimethylsiloxane) (PDMS) molds from laser-etched acrylic negative masters with ∼0.2 mm resolution. Examples of the variety of mold shapes, sizes, and patterns obtained from laser-etched designs are provided. We use the patterned PDMS molds for producing and culturing engineered cardiac tissues with cardiomyocytes derived from human-induced pluripotent stem cells. We demonstrate that tight control over tissue morphology and anisotropy results in modulation of cell alignment and tissue-level conduction properties, including the appearance and elimination of reentrant arrhythmias, or circular electrical activation patterns. Techniques for handling engineered cardiac tissues during implantation in vivo in a rat model of myocardial infarction have been developed and are presented herein to facilitate development and adoption of surgical techniques for use with hydrogel-based engineered tissues. In summary, the method presented herein for engineered tissue mold generation is straightforward and low cost, enabling rapid design iteration and adaptation to a variety of applications in tissue engineering. Furthermore, the burden of equipment and expertise is low, allowing the technique to be accessible to all. PMID:28457187

Crystal Engineering of an nbo Topology Metal-Organic Framework for Chemical Fixation of CO₂ under Ambient Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Wen-Yang; Chen, Yao; Niu, Youhong

Crystal engineering of the nbo metal–organic framework (MOF) platform MOF-505 with a custom-designed azamacrocycle ligand (1,4,7,10-tetrazazcyclododecane-N,N',N'',N'''-tetra-p-methylbenzoic acid) leads to a high density of well-oriented Lewis active sites within the cuboctahedral cage in MMCF-2, [Cu₂(Cu-tactmb)(H₂O)₃(NO₃)₂]. This MOF demonstrates high catalytic activity for the chemical fixation of CO₂ into cyclic carbonates at room temperature under 1 atm pressure.

Materials Science Laboratory

NASA Technical Reports Server (NTRS)

Jackson, Dionne

2005-01-01

The NASA Materials Science Laboratory (MSL) provides science and engineering services to NASA and Contractor customers at KSC, including those working for the Space Shuttle. International Space Station. and Launch Services Programs. These services include: (1) Independent/unbiased failure analysis (2) Support to Accident/Mishap Investigation Boards (3) Materials testing and evaluation (4) Materials and Processes (M&P) engineering consultation (5) Metrology (6) Chemical analysis (including ID of unknown materials) (7) Mechanical design and fabrication We provide unique solutions to unusual and urgent problems associated with aerospace flight hardware, ground support equipment and related facilities.

Commercial considerations in tissue engineering

PubMed Central

Mansbridge, Jonathan

2006-01-01

Tissue engineering is a field with immense promise. Using the example of an early tissue-engineered skin implant, Dermagraft, factors involved in the successful commercial development of devices of this type are explored. Tissue engineering has to strike a balance between tissue culture, which is a resource-intensive activity, and business considerations that are concerned with minimizing cost and maximizing customer convenience. Bioreactor design takes place in a highly regulated environment, so factors to be incorporated into the concept include not only tissue culture considerations but also matters related to asepsis, scaleup, automation and ease of use by the final customer. Dermagraft is an allogeneic tissue. Stasis preservation, in this case cryopreservation, is essential in allogeneic tissue engineering, allowing sterility testing, inventory control and, in the case of Dermagraft, a cellular stress that may be important for hormesis following implantation. Although the use of allogeneic cells provides advantages in manufacturing under suitable conditions, it raises the spectre of immunological rejection. Such rejection has not been experienced with Dermagraft. Possible reasons for this and the vision of further application of allogeneic tissues are important considerations in future tissue-engineered cellular devices. This review illustrates approaches that indicate some of the criteria that may provide a basis for further developments. Marketing is a further requirement for success, which entails understanding of the mechanism of action of the procedure, and is illustrated for Dermagraft. The success of a tissue-engineered product is dependent on many interacting operations, some discussed here, each of which must be performed simultaneously and well. PMID:17005024

Commercial considerations in tissue engineering.

PubMed

Mansbridge, Jonathan

2006-10-01

Tissue engineering is a field with immense promise. Using the example of an early tissue-engineered skin implant, Dermagraft, factors involved in the successful commercial development of devices of this type are explored. Tissue engineering has to strike a balance between tissue culture, which is a resource-intensive activity, and business considerations that are concerned with minimizing cost and maximizing customer convenience. Bioreactor design takes place in a highly regulated environment, so factors to be incorporated into the concept include not only tissue culture considerations but also matters related to asepsis, scaleup, automation and ease of use by the final customer. Dermagraft is an allogeneic tissue. Stasis preservation, in this case cryopreservation, is essential in allogeneic tissue engineering, allowing sterility testing, inventory control and, in the case of Dermagraft, a cellular stress that may be important for hormesis following implantation. Although the use of allogeneic cells provides advantages in manufacturing under suitable conditions, it raises the spectre of immunological rejection. Such rejection has not been experienced with Dermagraft. Possible reasons for this and the vision of further application of allogeneic tissues are important considerations in future tissue-engineered cellular devices. This review illustrates approaches that indicate some of the criteria that may provide a basis for further developments. Marketing is a further requirement for success, which entails understanding of the mechanism of action of the procedure, and is illustrated for Dermagraft. The success of a tissue-engineered product is dependent on many interacting operations, some discussed here, each of which must be performed simultaneously and well.

Transplantation of dedifferentiated fat cell-derived micromass pellets contributed to cartilage repair in the rat osteochondral defect model.

PubMed

Shimizu, Manabu; Matsumoto, Taro; Kikuta, Shinsuke; Ohtaki, Munenori; Kano, Koichiro; Taniguchi, Hiroaki; Saito, Shu; Nagaoka, Masahiro; Tokuhashi, Yasuaki

2018-03-20

Mature adipocyte-derived dedifferentiated fat (DFAT) cells possesses the ability to proliferate effectively and the potential to differentiate into multiple linages of mesenchymal tissue; similar to adipose-derived stem cells (ASCs). The purpose of this study is to examine the effects of DFAT cell transplantation on cartilage repair in a rat model of osteochondral defects. Full-thickness osteochondral defects were created in the knees of Sprague-Dawley rats bilaterally. Cartilage-like micromass pellets were prepared from green fluorescent protein (GFP)-labeled rat DFAT cells and subsequently transplanted into the affected right knee of these rats. Defects in the left knee were used as a control. Macroscopic and microscopic changes of treated and control defects were evaluated up to 12 weeks post-treatment with DFAT cells. To observe the transplanted cells, sectioned femurs were immunostained for GFP and type II collagen. DFAT cells formed micromass pellets expressing characteristics of immature cartilage in vitro. In the DFAT cell-transplanted limbs, the defects were completely filled with white micromass pellets as early as 2 weeks post-treatment. These limbs became smooth at 4 weeks. Conversely, the defects in the control limbs were still not repaired by 4 weeks. Macroscopic ICRS scores at 2 and 4 weeks were significantly higher in the DFAT cells-transplanted limbs compared to those of the control limbs. The modified O'Driscol histological scores for the DFAT cell-transplanted limbs were significantly higher than those of the control limbs at corresponding time points. GFP-positive DAFT cells were detected in the transplanted area at 2 weeks but hardly visible at 12 weeks post-operation. Transplantation of DFAT cell-derived micromass pellets contribute to cartilage repair in a rat osteochondral defect model. DFAT cell transplantation may be a viable therapeutic strategy for the repair of osteochondral injuries. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

RFM-based eco-efficiency analysis using Takagi-Sugeno fuzzy and AHP approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Ruiyang

2009-04-15

Eco-design is crucial to take environmental aspects into account in the phases of design. Few literature review that green product must meet market value. The development of models to predict market value is thus very useful because it can provide early eco-efficiency to the eco-design. For the eco-design engineer, when he tries to solve a customer feedback problem, he usually faces the eco-efficiency. There are, however, often other types of fuzziness uncertainty present, which are related to the quantity of eco-design conditions. In this paper, it is derived that analysis of eco-efficiency can be identified by using the RFM valuemore » for quantifying eco-design with Takagi-Sugeno fuzzy system on customer feedback problem. It clusters eco-efficiency into segments according to green product usages value expressed in terms of weighted RFM. This experiment examined the weighted RFM effect of overall average normalized, AHP and non-weighted for F1 metric. The experimental results show that the proposed methodology indeed can yield identification of higher quality.« less

What is the Final Verification of Engineering Requirements?

NASA Technical Reports Server (NTRS)

Poole, Eric

2010-01-01

This slide presentation reviews the process of development through the final verification of engineering requirements. The definition of the requirements is driven by basic needs, and should be reviewed by both the supplier and the customer. All involved need to agree upon a formal requirements including changes to the original requirements document. After the requirements have ben developed, the engineering team begins to design the system. The final design is reviewed by other organizations. The final operational system must satisfy the original requirements, though many verifications should be performed during the process. The verification methods that are used are test, inspection, analysis and demonstration. The plan for verification should be created once the system requirements are documented. The plan should include assurances that every requirement is formally verified, that the methods and the responsible organizations are specified, and that the plan is reviewed by all parties. The options of having the engineering team involved in all phases of the development as opposed to having some other organization continue the process once the design has been complete is discussed.

How to improve the promotion of Korean beef barbecue, bulgogi, for international customers. An application of quality function deployment.

PubMed

Park, So-Hyun; Ham, Sunny; Lee, Min-A

2012-10-01

Quality function deployment (QFD) is a product development technique that translates customer requirements into activities for the development of products and services. This study utilizes QFD to identify American customer's requirements for bulgogi, a popular Korean dish among international customers, and how to fulfill those requirements. A customer survey and an expert opinion survey were conducted for US customers. The top five customer requirements for bulgogi were identified as taste, freshness, flavor, tenderness, and juiciness; ease of purchase was included in the place of tenderness after calculating the weight requirements. Eighteen engineering characteristics were developed, and a 'localization of bulgogi menu' is strongly related to the other characteristics as well. The results from the calculation of relative importance of engineering characteristics identified that the 'control of marinating time', 'localization of bulgogi menu', 'improvement of cooking and serving process', 'development of recipe by parts of beef', and 'use of various seasonings' were the highest contributors to the overall improvement of bulgogi. The relative importance of engineering characteristics, correlation, and technical difficulties are ranked and integrated to develop the most effective strategy. The findings are discussed relative to industry implications. Copyright © 2012 Elsevier Ltd. All rights reserved.

A Planning Approach of Engineering Characteristics Based on QFD-TRIZ Integrated

NASA Astrophysics Data System (ADS)

Liu, Shang; Shi, Dongyan; Zhang, Ying

Traditional QFD planning method compromises contradictions between engineering characteristics to achieve higher customer satisfaction. However, this compromise trade-off can not eliminate the contradictions existing among the engineering characteristics which limited the overall customer satisfaction. QFD (Quality function deployment) integrated with TRIZ (the Russian acronym of the Theory of Inventive Problem Solving) becomes hot research recently for TRIZ can be used to solve contradictions between engineering characteristics which construct the roof of HOQ (House of quality). But, the traditional QFD planning approach is not suitable for QFD integrated with TRIZ for that TRIZ requires emphasizing the contradictions between engineering characteristics at problem definition stage instead of compromising trade-off. So, a new planning approach based on QFD / TRIZ integration is proposed in this paper, which based on the consideration of the correlation matrix of engineering characteristics and customer satisfaction on the basis of cost. The proposed approach suggests that TRIZ should be applied to solve contradictions at the first step, and the correlation matrix of engineering characteristics should be amended at the second step, and at next step IFR (ideal final result) must be validated, then planning execute. An example is used to illustrate the proposed approach. The application indicated that higher customer satisfaction can be met and the contradictions between the characteristic parameters are eliminated.

Coping with Variability in Model-Based Systems Engineering: An Experience in Green Energy

NASA Astrophysics Data System (ADS)

Trujillo, Salvador; Garate, Jose Miguel; Lopez-Herrejon, Roberto Erick; Mendialdua, Xabier; Rosado, Albert; Egyed, Alexander; Krueger, Charles W.; de Sosa, Josune

Model-Based Systems Engineering (MBSE) is an emerging engineering discipline whose driving motivation is to provide support throughout the entire system life cycle. MBSE not only addresses the engineering of software systems but also their interplay with physical systems. Quite frequently, successful systems need to be customized to cater for the concrete and specific needs of customers, end-users, and other stakeholders. To effectively meet this demand, it is vital to have in place mechanisms to cope with the variability, the capacity to change, that such customization requires. In this paper we describe our experience in modeling variability using SysML, a leading MBSE language, for developing a product line of wind turbine systems used for the generation of electricity.

Modeling Languages Refine Vehicle Design

NASA Technical Reports Server (NTRS)

2009-01-01

Cincinnati, Ohio s TechnoSoft Inc. is a leading provider of object-oriented modeling and simulation technology used for commercial and defense applications. With funding from Small Business Innovation Research (SBIR) contracts issued by Langley Research Center, the company continued development on its adaptive modeling language, or AML, originally created for the U.S. Air Force. TechnoSoft then created what is now known as its Integrated Design and Engineering Analysis Environment, or IDEA, which can be used to design a variety of vehicles and machinery. IDEA's customers include clients in green industries, such as designers for power plant exhaust filtration systems and wind turbines.

Accurate reconstruction of discontinuous mandible using a reverse engineering/computer-aided design/rapid prototyping technique: a preliminary clinical study.

PubMed

Zhou, Li-bin; Shang, Hong-tao; He, Li-sheng; Bo, Bin; Liu, Gui-cai; Liu, Yan-pu; Zhao, Jin-long

2010-09-01

To improve the reconstructive surgical outcome of a discontinuous mandibular defect, we used reverse engineering (RE), computer-aided design (CAD), and rapid prototyping (RP) technique to fabricate customized mandibular trays to precisely restore the mandibular defects. Autogenous bone grafting was also used to restore the bony continuity for occlusion rehabilitation. Six patients who had undergone block resection of the mandible underwent reconstruction using a custom titanium tray combining autogenous iliac grafts. The custom titanium tray was made using a RE/CAD/RP technique. A virtual 3-dimensional model was obtained by spiral computed tomography scanning. The opposite side of the mandible was mirrored to cover the defect area to restore excellent facial symmetry. A bone grafting tray was designed from the mirrored image and manufactured using RP processing and casting. The mandibular defects were restored using the trays in combination of autologous iliac grafting. An implant denture was made for 1 of the 6 patients at 24 weeks postoperatively for occlusion rehabilitation. The trays fabricated using this technique fit well in all 6 patients. The reconstructive procedures were easy and time saving. Satisfactory facial symmetry was restored. No severe complications occurred in the 5 patients without occlusion rehabilitation during a mean 50-month follow-up period. The reconstruction in the patient with occlusion lasted for only 1 year and failed eventually because of bone resorption and infection. Mandibular reconstruction was facilitated using the RE/CAD/RP technique. Satisfactory esthetic results were achieved. However, the rigidity of the cast tray could cause severe stress shielding to the grafts, which could lead to disuse atrophy. Therefore, some modification is needed for functional reconstruction. Copyright 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Cartilage repair using mesenchymal stem cell (MSC) sheet and MSCs-loaded bilayer PLGA scaffold in a rabbit model.

PubMed

Qi, Yiying; Du, Yi; Li, Weixu; Dai, Xuesong; Zhao, Tengfei; Yan, Weiqi

2014-06-01

The integration of regenerated cartilage with surrounding native cartilage is a major challenge for the success of cartilage tissue-engineering strategies. The purpose of this study is to investigate whether incorporation of the power of mesenchymal stem cell (MSC) sheet to MSCs-loaded bilayer poly-(lactic-co-glycolic acid) (PLGA) scaffolds can improve the integration and repair of cartilage defects in a rabbit model. Rabbit bone marrow-derived MSCs were cultured and formed cell sheet. Full-thickness cylindrical osteochondral defects (4 mm in diameter, 3 mm in depth) were created in the patellar groove of 18 New Zealand white rabbits and the osteochondral defects were treated with PLGA scaffold (n = 6), PLGA/MSCs (n = 6) or MSC sheet-encapsulated PLGA/MSCs (n = 6). After 6 and 12 weeks, the integration and tissue response were evaluated histologically. The MSC sheet-encapsulated PLGA/MCSs group showed significantly more amounts of hyaline cartilage and higher histological scores than PLGA/MSCs group and PLGA group (P < 0.05). In addition, the MSC sheet-encapsulated PLGA/MCSs group showed the best integration between the repaired cartilage and surrounding normal cartilage and subchondral bone compared to other two groups. The novel method of incorporation of MSC sheet to PLGA/MCSs could enhance the ability of cartilage regeneration and integration between repair cartilage and the surrounding cartilage. Transplantation of autologous MSC sheet combined with traditional strategies or cartilage debris might provide therapeutic opportunities for improving cartilage regeneration and integration in humans.

A New Chemistry Course for Non-Chemistry Majors.

ERIC Educational Resources Information Center

Ariel, Magda; And Others

1982-01-01

A two-semester basic chemistry course for nonchemistry engineering majors is described. First semester provides introductory chemistry for freshmen while second semester is "customer-oriented," based on a departmental choice of three out of six independent modules. For example, aeronautical engineering "customers" would select…

Robot Training With Vector Fields Based on Stroke Survivors' Individual Movement Statistics.

PubMed

Wright, Zachary A; Lazzaro, Emily; Thielbar, Kelly O; Patton, James L; Huang, Felix C

2018-02-01

The wide variation in upper extremity motor impairments among stroke survivors necessitates more intelligent methods of customized therapy. However, current strategies for characterizing individual motor impairments are limited by the use of traditional clinical assessments (e.g., Fugl-Meyer) and simple engineering metrics (e.g., goal-directed performance). Our overall approach is to statistically identify the range of volitional movement capabilities, and then apply a robot-applied force vector field intervention that encourages under-expressed movements. We investigated whether explorative training with such customized force fields would improve stroke survivors' (n = 11) movement patterns in comparison to a control group that trained without forces (n = 11). Force and control groups increased Fugl-Meyer UE scores (average of 1.0 and 1.1, respectively), which is not considered clinically meaningful. Interestingly, participants from both groups demonstrated dramatic increases in their range of velocity during exploration following only six days of training (average increase of 166.4% and 153.7% for the Force and Control group, respectively). While both groups showed evidence of improvement, we also found evidence that customized forces affected learning in a systematic way. When customized forces were active, we observed broader distributions of velocity that were not present in the controls. Second, we found that these changes led to specific changes in unassisted motion. In addition, while the shape of movement distributions changed significantly for both groups, detailed analysis of the velocity distributions revealed that customized forces promoted a greater proportion of favorable changes. Taken together, these results provide encouraging evidence that patient-specific force fields based on individuals' movement statistics can be used to create new movement patterns and shape them in a customized manner. To the best of our knowledge, this paper is the first to directly link engineering assessments of stroke survivors' exploration movement behaviors to the design of customized robot therapy.

Magnetic resonance imaging-three-dimensional printing technology fabricates customized scaffolds for brain tissue engineering

PubMed Central

Fu, Feng; Qin, Zhe; Xu, Chao; Chen, Xu-yi; Li, Rui-xin; Wang, Li-na; Peng, Ding-wei; Sun, Hong-tao; Tu, Yue; Chen, Chong; Zhang, Sai; Zhao, Ming-liang; Li, Xiao-hong

2017-01-01

Conventional fabrication methods lack the ability to control both macro- and micro-structures of generated scaffolds. Three-dimensional printing is a solid free-form fabrication method that provides novel ways to create customized scaffolds with high precision and accuracy. In this study, an electrically controlled cortical impactor was used to induce randomized brain tissue defects. The overall shape of scaffolds was designed using rat-specific anatomical data obtained from magnetic resonance imaging, and the internal structure was created by computer-aided design. As the result of limitations arising from insufficient resolution of the manufacturing process, we magnified the size of the cavity model prototype five-fold to successfully fabricate customized collagen-chitosan scaffolds using three-dimensional printing. Results demonstrated that scaffolds have three-dimensional porous structures, high porosity, highly specific surface areas, pore connectivity and good internal characteristics. Neural stem cells co-cultured with scaffolds showed good viability, indicating good biocompatibility and biodegradability. This technique may be a promising new strategy for regenerating complex damaged brain tissues, and helps pave the way toward personalized medicine. PMID:28553343

SSC Engineering Analysis

NASA Technical Reports Server (NTRS)

Ryan, Harry; Junell, Justin; Albasini, Colby; O'Rourke, William; Le, Thang; Strain, Ted; Stiglets, Tim

2011-01-01

A package for the automation of the Engineering Analysis (EA) process at the Stennis Space Center has been customized. It provides the ability to assign and track analysis tasks electronically, and electronically route a task for approval. It now provides a mechanism to keep these analyses under configuration management. It also allows the analysis to be stored and linked to the engineering data that is needed to perform the analysis (drawings, etc.). PTC s (Parametric Technology Corp o ration) Windchill product was customized to allow the EA to be created, routed, and maintained under configuration management. Using Infoengine Tasks, JSP (JavaServer Pages), Javascript, a user interface was created within the Windchill product that allows users to create EAs. Not only does this interface allow users to create and track EAs, but it plugs directly into the out-ofthe- box ability to associate these analyses with other relevant engineering data such as drawings. Also, using the Windchill workflow tool, the Design and Data Management System (DDMS) team created an electronic routing process based on the manual/informal approval process. The team also added the ability for users to notify and track notifications to individuals about the EA. Prior to the Engineering Analysis creation, there was no electronic way of creating and tracking these analyses. There was also a feature that was added that would allow users to track/log e-mail notifications of the EA.

Osteochondral repair in hemophilic ankle arthropathy: from current options to future perspectives

PubMed Central

BUDA, ROBERTO; CAVALLO, MARCO; CASTAGNINI, FRANCESCO; FERRANTI, ENRICO; NATALI, SIMONE; GIANNINI, SANDRO

2015-01-01

Young hemophilic patients are frequently affected by ankle arthropathy. At the end stage of the disease, the current treatments are arthrodesis and arthroplasty, which have significant drawbacks. Validated procedures capable of slowing down or even arresting the progression towards the end stage are currently lacking. This review aims to discuss the rationale for and feasibility of applying, in mild hemophilic ankle arthropathy, the main techniques currently used to treat osteochondral defects, focusing in particular on ankle distraction, chondrocyte implantation, mesenchymal stem cell transplantation, allograft transplantation and the use of growth factors. To date, ankle distraction is the only procedure that has been successfully used in hemophilic ankle arthropathy. The use of mesenchymal stem cells have recently been evaluated as feasible for osteochondral repair in hemophilic patients. There may be a rationale for the use of growth factors if they are combined with the previous techniques, which could be useful to arrest the progression of the degeneration or delay end-stage procedures. PMID:26904526

Osteochondritis Dessicans- Primary Fixation using Bioabsorbable Implants

PubMed Central

Galagali, Anand; Rao, Muralidhar

2012-01-01

Introduction: Osteochondritis dessicans (OCD) is a localized condition where a section of articular cartilage and underlying subchondral bone separate from the joint surface. It is important to diagnose unstable OCD early and fix the fragments primarily as the results of any surgical management at late presentations are guarded. Use of bioabsorbable implants for fixing OCD is recent and we report one such case in grade IV OCD. Case Report: We present a 14 year old girl who came with a history of acute pain, swelling, inability to bear weight on the right knee following a dance practice. MRI showed stage IV osteochondral fragment measuring 20x 8mm lying free. This was primarily fixed with bioabsorbable implants. 10 months follow up showed excellent clinical and functional results. Conclusion: This case highlights the advantages of early primary fixation whenever possible. By far, to our knowledge, this is the first case of successful treatment of stage IV OCD using bioabsorbable implants. PMID:27298854

Effect of Low-Intensity Pulsed Ultrasound after Mesenchymal Stromal Cell Injection to Treat Osteochondral Defects: An In Vivo Study.

PubMed

Yamaguchi, Shoki; Aoyama, Tomoki; Ito, Akira; Nagai, Momoko; Iijima, Hirotaka; Tajino, Junichi; Zhang, Xiangkai; Wataru, Kiyan; Kuroki, Hiroshi

2016-12-01

We investigated the effect of low-intensity pulsed ultrasound (LIPUS) treatment combined with mesenchymal stromal cell (MSC) injection for cartilage repair and subchondral bone reconstitution for treatment of osteochondral defects. An osteochondral defect was created on both femur grooves of Wistar rats. Four weeks later, bone marrow MSCs were injected into the right knee joint. The rats were divided into two intervention groups: without or with LIPUS irradiation. Cartilage repair was evaluated histologically based on the Wakitani cartilage repair score. Subchondral bone reconstitution was evaluated as bone volume (BV)/tissue volume (TV) by micro-computed tomography analysis. MSC injection improved the cartilage repair score, and LIPUS irradiation improved BV/TV. Combination treatment promoted both cartilage repair and BV/TV improvement. Thus, MSC injection combined with LIPUS irradiation is more effective than either treatment alone in promoting concurrent cartilage repair and subchondral reconstitution. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

A game-based decision support methodology for competitive systems design

NASA Astrophysics Data System (ADS)

Briceno, Simon Ignacio

This dissertation describes the development of a game-based methodology that facilitates the exploration and selection of research and development (R&D) projects under uncertain competitive scenarios. The proposed method provides an approach that analyzes competitor positioning and formulates response strategies to forecast the impact of technical design choices on a project's market performance. A critical decision in the conceptual design phase of propulsion systems is the selection of the best architecture, centerline, core size, and technology portfolio. This selection can be challenging when considering evolving requirements from both the airframe manufacturing company and the airlines in the market. Furthermore, the exceedingly high cost of core architecture development and its associated risk makes this strategic architecture decision the most important one for an engine company. Traditional conceptual design processes emphasize performance and affordability as their main objectives. These areas alone however, do not provide decision-makers with enough information as to how successful their engine will be in a competitive market. A key objective of this research is to examine how firm characteristics such as their relative differences in completing R&D projects, differences in the degree of substitutability between different project types, and first/second-mover advantages affect their product development strategies. Several quantitative methods are investigated that analyze business and engineering strategies concurrently. In particular, formulations based on the well-established mathematical field of game theory are introduced to obtain insights into the project selection problem. The use of game theory is explored in this research as a method to assist the selection process of R&D projects in the presence of imperfect market information. The proposed methodology focuses on two influential factors: the schedule uncertainty of project completion times and the uncertainty associated with competitive reactions. A normal-form matrix is created to enumerate players, their moves and payoffs, and to formulate a process by which an optimal decision can be achieved. The non-cooperative model is tested using the concept of a Nash equilibrium to identify potential strategies that are robust to uncertain market fluctuations (e.g: uncertainty in airline demand, airframe requirements and competitor positioning). A first/second-mover advantage parameter is used as a scenario dial to adjust market rewards and firms' payoffs. The methodology is applied to a commercial aircraft engine selection study where engine firms must select an optimal engine project for development. An engine modeling and simulation framework is developed to generate a broad engine project portfolio. The creation of a customer value model enables designers to incorporate airline operation characteristics into the engine modeling and simulation process to improve the accuracy of engine/customer matching. Summary. Several key findings are made that provide recommendations on project selection strategies for firms uncertain as to when they will enter the market. The proposed study demonstrates that within a technical design environment, a rational and analytical means of modeling project development strategies is beneficial in high market risk situations.

Toward a patient-specific tissue engineered vascular graft

PubMed Central

Best, Cameron; Strouse, Robert; Hor, Kan; Pepper, Victoria; Tipton, Amy; Kelly, John; Shinoka, Toshiharu; Breuer, Christopher

2018-01-01

Integrating three-dimensional printing with the creation of tissue-engineered vascular grafts could provide a readily available, patient-specific, autologous tissue source that could significantly improve outcomes in newborns with congenital heart disease. Here, we present the recent case of a candidate for our tissue-engineered vascular graft clinical trial deemed ineligible due to complex anatomical requirements and consider the application of three-dimensional printing technologies for a patient-specific graft. We 3D-printed a closed-disposable seeding device and validated that it performed equivalently to the traditional open seeding technique using ovine bone marrow–derived mononuclear cells. Next, our candidate’s preoperative imaging was reviewed to propose a patient-specific graft. A seeding apparatus was then designed to accommodate the custom graft and 3D-printed on a commodity fused deposition modeler. This exploratory feasibility study represents an important proof of concept advancing progress toward a rationally designed patient-specific tissue-engineered vascular graft for clinical application. PMID:29568478

Image-guided tissue engineering of anatomically shaped implants via MRI and micro-CT using injection molding.

PubMed

Ballyns, Jeffery J; Gleghorn, Jason P; Niebrzydowski, Vicki; Rawlinson, Jeremy J; Potter, Hollis G; Maher, Suzanne A; Wright, Timothy M; Bonassar, Lawrence J

2008-07-01

This study demonstrates for the first time the development of engineered tissues based on anatomic geometries derived from widely used medical imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI). Computer-aided design and tissue injection molding techniques have demonstrated the ability to generate living implants of complex geometry. Due to its complex geometry, the meniscus of the knee was used as an example of this technique's capabilities. MRI and microcomputed tomography (microCT) were used to design custom-printed molds that enabled the generation of anatomically shaped constructs that retained shape throughout 8 weeks of culture. Engineered constructs showed progressive tissue formation indicated by increases in extracellular matrix content and mechanical properties. The paradigm of interfacing tissue injection molding technology can be applied to other medical imaging techniques that render 3D models of anatomy, demonstrating the potential to apply the current technique to engineering of many tissues and organs.

Role of System Architecture in Architecture in Developing New Drafting Tools

NASA Astrophysics Data System (ADS)

Sorguç, Arzu Gönenç

In this study, the impact of information technologies in architectural design process is discussed. In this discussion, first the differences/nuances between the concept of software engineering and system architecture are clarified. Then, the design process in engineering, and design process in architecture has been compared by considering 3-D models as the center of design process over which the other disciplines involve the design. It is pointed out that in many high-end engineering applications, 3-D solid models and consequently digital mock-up concept has become a common practice. But, architecture as one of the important customers of CAD systems employing these tools has not started to use these 3-D models. It is shown that the reason of this time lag between architecture and engineering lies behind the tradition of design attitude. Therefore, it is proposed a new design scheme a meta-model to develop an integrated design model being centered on 3-D model. It is also proposed a system architecture to achieve the transformation of architectural design process by replacing 2-D thinking with 3-D thinking. It is stated that in the proposed system architecture, the CAD systems are included and adapted for 3-D architectural design in order to provide interfaces for integration of all possible disciplines to design process. It is also shown that such a change will allow to elaborate the intelligent or smart building concept in future.

Hands on Education Through Student-Industry Partnerships

NASA Astrophysics Data System (ADS)

Brown, J.; Wolfson, M.; Morris, K.

2013-09-01

Lockheed Martin Space Systems Company has invested in the future generation of engineers by partially funding and mentoring CubeSat projects around the country. One CubeSat in particular, ALL-STAR, has shown how this industry/university partnership benefits both the students and their mentors. Students gain valuable insight into aspects of spacecraft design that aren't taught in classes. They also start learning about industry processes for designing, building, and testing satellites before ever working in that environment. Because of this experience, industry is getting more qualified engineers starting fresh out of college. In addition Lockheed Martin's partnership with the university will allow them to use the students to help build affordable CubeSats for internal and customer's research and development projects. The mentoring also challenges the engineers to think differently about similar problems they face every day with their larger programs in order to make the solution simple and affordable.

A low cost, customizable turbidostat for use in synthetic circuit characterization.

PubMed

Takahashi, Chris N; Miller, Aaron W; Ekness, Felix; Dunham, Maitreya J; Klavins, Eric

2015-01-16

Engineered biological circuits are often disturbed by a variety of environmental factors. In batch culture, where the majority of synthetic circuit characterization occurs, environmental conditions vary as the culture matures. Turbidostats are powerful characterization tools that provide static culture environments; however, they are often expensive, especially when purchased in custom configurations, and are difficult to design and construct in a lab. Here, we present a low cost, open source multiplexed turbidostat that can be manufactured and used with minimal experience in electrical or software engineering. We demonstrate the utility of this system to profile synthetic circuit behavior in S. cerevisiae. We also demonstrate the flexibility of the design by showing that a fluorometer can be easily integrated.

Effects of process parameters in plastic, metal, and ceramic injection molding processes

NASA Astrophysics Data System (ADS)

Lee, Shi W.; Ahn, Seokyoung; Whang, Chul Jin; Park, Seong Jin; Atre, Sundar V.; Kim, Jookwon; German, Randall M.

2011-09-01

Plastic injection molding has been widely used in the past and is a dominant forming approach today. As the customer demands require materials with better engineering properties that were not feasible with polymers, powder injection molding with metal and ceramic powders has received considerable attention in recent decades. To better understand the differences in the plastic injection molding, metal injection molding, and ceramic injection molding, the effects of the core process parameters on the process performances has been studied using the state-of-the-art computer-aided engineering (CAE) design tool, PIMSolver® The design of experiments has been conducted using the Taguchi method to obtain the relative contributions of various process parameters onto the successful operations.

Bioactive Scaffolds for Regeneration of Cartilage and Subchondral Bone Interface

PubMed Central

Deng, Cuijun; Zhu, Huiying; Li, Jiayi; Feng, Chun; Yao, Qingqiang; Wang, Liming; Chang, Jiang; Wu, Chengtie

2018-01-01

The cartilage lesion resulting from osteoarthritis (OA) always extends into subchondral bone. It is of great importance for simultaneous regeneration of two tissues of cartilage and subchondral bone. 3D-printed Sr5(PO4)2SiO4 (SPS) bioactive ceramic scaffolds may achieve the aim of regenerating both of cartilage and subchondral bone. We hypothesized that strontium (Sr) and silicon (Si) ions released from SPS scaffolds play a crucial role in osteochondral defect reconstruction. Methods: SPS bioactive ceramic scaffolds were fabricated by a 3D-printing method. The SEM and ICPAES were used to investigate the physicochemical properties of SPS scaffolds. The proliferation and maturation of rabbit chondrocytes stimulated by SPS bioactive ceramics were measured in vitro. The stimulatory effect of SPS scaffolds for cartilage and subchondral bone regeneration was investigated in vivo. Results: SPS scaffolds significantly stimulated chondrocyte proliferation, and SPS extracts distinctly enhanced the maturation of chondrocytes and preserved chondrocytes from OA. SPS scaffolds markedly promoted the regeneration of osteochondral defects. The complex interface microstructure between cartilage and subchondral bone was obviously reconstructed. The underlying mechanism may be related to Sr and Si ions stimulating cartilage regeneration by activating HIF pathway and promoting subchondral bone reconstruction through activating Wnt pathway, as well as preserving chondrocytes from OA via inducing autophagy and inhibiting hedgehog pathway. Conclusion: Our findings suggest that SPS scaffolds can help osteochondral defect reconstruction and well reconstruct the complex interface between cartilage and subchondral bone, which represents a promising strategy for osteochondral defect regeneration. PMID:29556366

Ex vivo culture platform for assessment of cartilage repair treatment strategies.

PubMed

Schwab, Andrea; Meeuwsen, Annick; Ehlicke, Franziska; Hansmann, Jan; Mulder, Lars; Smits, Anthal; Walles, Heike; Kock, Linda

2017-01-01

There is a great need for valuable ex vivo models that allow for assessment of cartilage repair strategies to reduce the high number of animal experiments. In this paper we present three studies with our novel ex vivo osteochondral culture platform. It consists of two separated media compartments for cartilage and bone, which better represents the in vivo situation and enables supply of factors specific to the different needs of bone and cartilage. We investigated whether separation of the cartilage and bone compartments and/or culture media results in the maintenance of viability, structural and functional properties of cartilage tissue. Next, we evaluated for how long we can preserve cartilage matrix stability of osteochondral explants during long-term culture over 84 days. Finally, we determined the optimal defect size that does not show spontaneous self-healing in this culture system. It was demonstrated that separated compartments for cartilage and bone in combination with tissue-specific medium allow for long-term culture of osteochondral explants while maintaining cartilage viability, matrix tissue content, structure and mechanical properties for at least 56 days. Furthermore, we could create critical size cartilage defects of different sizes in the model. The osteochondral model represents a valuable preclinical ex vivo tool for studying clinically relevant cartilage therapies, such as cartilage biomaterials, for their regenerative potential, for evaluation of drug and cell therapies, or to study mechanisms of cartilage regeneration. It will undoubtedly reduce the number of animals needed for in vivo testing.

Rabbit Trochlear Model of Osteochondral Allograft Transplantation

PubMed Central

To, Nhat; Curtiss, Shane; Neu, Corey P; Salgado, Christopher J; Jamali, Amir A

2011-01-01

Allografting and autografting of osteochondral tissues is a promising strategy to treat articular cartilage lesions in damaged joints. We developed a new model of fresh osteochondral allografting using the entire rabbit trochlea. The objective of the current study was to demonstrate that this model would achieve reproducible graft–host healing and maintain normal articular cartilage histologic, immunolocalization, and biochemical characteristics after transplantation under diverse storage and transplantation conditions. New Zealand white (n = 8) and Dutch belted (n = 8) rabbits underwent a 2-stage transplantation operation using osteochondral grafts that had been stored for 2 or 4 wk. Trochlear grafts harvested from the left knee were transplanted to the right knee as either autografts or allografts. Grafts were fixed with 22-gauge steel wire or 3-0 nylon suture. Rabbits were euthanized for evaluation at 1, 2, 4, 6, and 12 wk after transplantation. All grafts that remained in vivo for at least 4 wk demonstrated 100% interface healing by microCT. Trabecular bridging was present at the host–graft interface starting at 2 wk after transplantation, with no significant difference in cartilage histology between the various groups. The combined histology scores indicated minimal evidence of osteoarthritis. Immunostaining revealed that superficial zone protein was localized at the surface of all transplants. The rabbit trochlear model met our criteria for a successful model in regard to the ease of the procedure, low rate of surgical complications, relatively large articular cartilage surface area, and amount of host–graft bone interface available for analysis. PMID:22330350

Radiographic changes in Thoroughbred yearlings in South Africa.

PubMed

Furniss, C; Carstens, A; van den Berg, S S

2011-12-01

This study involves the evaluation of pre-purchase radiographic studies of South African Thoroughbred yearlings. Radiographic changes were recorded and compared with similar international studies. The study differs from other studies in that a lower prevalence of pedal osteitis (1.26%), dorsal osteochondral fragmentation of the metatarsophalangeal joint (1.60%), distal metacarpal sagittal ridge changes (15.7%), ulnar carpal bone lucencies (8.33%), carpal osteophytes (1.19%), distal intertarsal and tarsometatarsal joint radiographic changes (9.92%), tarsal osteochondrosis lesions (4.40%) and stifle osteochondrosis lesions (0.4%) was found. The prevalence of dorsal osteochondral fragments in the metacarpophalangeal joint was similar to other studies (1.60%). A higher prevalence of vascular channels as well as irregular borders and lucencies was evident in the proximal sesamoid bones. There was a higher prevalence of palmar metacarpophalangeal and plantar metatarsophalangeal osteochondral fragments (2% and 7.10% respectively). Palmar metacarpal disease, metacarpal supracondylar lysis, proximal sesamoid bone fractures and carpal osteochondral fragmentation were absent in the current study. Additional findings recorded in the current study were proximal interphalangeal joint hyperextension (left front 15.13%, right front 18.91%), the solar angle (right front 2.38 degrees, left front 2.79 degrees), the prevalence of carpal bone 1 (30.95%) and carpal bone 5 (1.59%). Management, nutrition and genetics in the various groups of Thoroughbred yearlings should be further investigated in order to explain the reasons for the differences recorded in the current study.

Osteochondral integration of multiply incised pure cartilage allograft: repair method of focal chondral defects in a porcine model.

PubMed

Bardos, Tamas; Farkas, Boglarka; Mezes, Beata; Vancsodi, Jozsef; Kvell, Krisztian; Czompoly, Tamas; Nemeth, Peter; Bellyei, Arpad; Illes, Tamas

2009-11-01

A focal cartilage lesion has limited capacity to heal, and the repair modalities used at present are still unable to provide a universal solution. Pure cartilage graft implantation appears to be a simple option, but it has not been applied widely as cartilage will not reattach easily to the subchondral bone. We used a multiple-incision technique (processed chondrograft) to increase cartilage graft surface. We hypothesized that pure cartilage graft with augmented osteochondral fusion capacity may be used for cartilage repair and we compared this method with other repair techniques. Controlled laboratory study. Full-thickness focal cartilage defects were created on the medial femoral condyle of 9-month-old pigs; defects were repaired using various methods including bone marrow stimulation, autologous chondrocyte implantation, and processed chondrograft. After the repair, at weeks 6 and 24, macroscopic and histologic evaluation was carried out. Compared with other methods, processed chondrograft was found to be similarly effective in cartilage repair. Defects without repair and defects treated with bone marrow stimulation appeared slightly irregular with fibrocartilage filling. Autologous chondrocyte implantation produced hyalinelike cartilage, although its cellular organization was distinguishable from the surrounding articular cartilage. Processed chondrograft demonstrated good osteochondral integration, and the resulting tissue appeared to be hyaline cartilage. The applied cartilage surface processing method allows acceptable osteochondral integration, and the repair tissue appears to have good macroscopic and histologic characteristics. If further studies confirm its efficacy, this technique could be considered for human application in the future.

Application of Extrusion-Based Hydrogel Bioprinting for Cartilage Tissue Engineering.

PubMed

You, Fu; Eames, B Frank; Chen, Xiongbiao

2017-07-23

Extrusion-based bioprinting (EBB) is a rapidly developing technique that has made substantial progress in the fabrication of constructs for cartilage tissue engineering (CTE) over the past decade. With this technique, cell-laden hydrogels or bio-inks have been extruded onto printing stages, layer-by-layer, to form three-dimensional (3D) constructs with varying sizes, shapes, and resolutions. This paper reviews the cell sources and hydrogels that can be used for bio-ink formulations in CTE application. Additionally, this paper discusses the important properties of bio-inks to be applied in the EBB technique, including biocompatibility, printability, as well as mechanical properties. The printability of a bio-ink is associated with the formation of first layer, ink rheological properties, and crosslinking mechanisms. Further, this paper discusses two bioprinting approaches to build up cartilage constructs, i.e., self-supporting hydrogel bioprinting and hybrid bioprinting, along with their applications in fabricating chondral, osteochondral, and zonally organized cartilage regenerative constructs. Lastly, current limitations and future opportunities of EBB in printing cartilage regenerative constructs are reviewed.

Repair and tissue engineering techniques for articular cartilage

PubMed Central

Makris, Eleftherios A.; Gomoll, Andreas H.; Malizos, Konstantinos N.; Hu, Jerry C.; Athanasiou, Kyriacos A.

2015-01-01

Chondral and osteochondral lesions due to injury or other pathology commonly result in the development of osteoarthritis, eventually leading to progressive total joint destruction. Although current progress suggests that biologic agents can delay the advancement of deterioration, such drugs are incapable of promoting tissue restoration. The limited ability of articular cartilage to regenerate renders joint arthroplasty an unavoidable surgical intervention. This Review describes current, widely used clinical repair techniques for resurfacing articular cartilage defects; short-term and long-term clinical outcomes of these techniques are discussed. Also reviewed is a developmental pipeline of regenerative biological products that over the next decade could revolutionize joint care by functionally healing articular cartilage. These products include cell-based and cell-free materials such as autologous and allogeneic cell-based approaches and multipotent and pluripotent stem-cell-based techniques. Central to these efforts is the prominent role that tissue engineering has in translating biological technology into clinical products; therefore, concomitant regulatory processes are also discussed. PMID:25247412

Repair and tissue engineering techniques for articular cartilage.

PubMed

Makris, Eleftherios A; Gomoll, Andreas H; Malizos, Konstantinos N; Hu, Jerry C; Athanasiou, Kyriacos A

2015-01-01

Chondral and osteochondral lesions due to injury or other pathology commonly result in the development of osteoarthritis, eventually leading to progressive total joint destruction. Although current progress suggests that biologic agents can delay the advancement of deterioration, such drugs are incapable of promoting tissue restoration. The limited ability of articular cartilage to regenerate renders joint arthroplasty an unavoidable surgical intervention. This Review describes current, widely used clinical repair techniques for resurfacing articular cartilage defects; short-term and long-term clinical outcomes of these techniques are discussed. Also reviewed is a developmental pipeline of acellular and cellular regenerative products and techniques that could revolutionize joint care over the next decade by promoting the development of functional articular cartilage. Acellular products typically consist of collagen or hyaluronic-acid-based materials, whereas cellular techniques use either primary cells or stem cells, with or without scaffolds. Central to these efforts is the prominent role that tissue engineering has in translating biological technology into clinical products; therefore, concomitant regulatory processes are also discussed.

Systematic Propulsion Optimization Tools (SPOT)

NASA Technical Reports Server (NTRS)

Bower, Mark; Celestian, John

1992-01-01

This paper describes a computer program written by senior-level Mechanical Engineering students at the University of Alabama in Huntsville which is capable of optimizing user-defined delivery systems for carrying payloads into orbit. The custom propulsion system is designed by the user through the input of configuration, payload, and orbital parameters. The primary advantages of the software, called Systematic Propulsion Optimization Tools (SPOT), are a user-friendly interface and a modular FORTRAN 77 code designed for ease of modification. The optimization of variables in an orbital delivery system is of critical concern in the propulsion environment. The mass of the overall system must be minimized within the maximum stress, force, and pressure constraints. SPOT utilizes the Design Optimization Tools (DOT) program for the optimization techniques. The SPOT program is divided into a main program and five modules: aerodynamic losses, orbital parameters, liquid engines, solid engines, and nozzles. The program is designed to be upgraded easily and expanded to meet specific user needs. A user's manual and a programmer's manual are currently being developed to facilitate implementation and modification.

Channeled Scaffolds for Engineering Myocardium with Mechanical Stimulation

PubMed Central

Zhang, Ting; Wan, Leo Q.; Xiong, Zhuo; Marsano, Anna; Maidhof, Robert; Park, Miri; Yan, Yongnian; Vunjak-Novakovic, Gordana

2011-01-01

The characteristics of the matrix (composition, structure, mechanical properties) and external culture environment (pulsatile perfusion, physical stimulation) are critically important for engineering functional myocardial tissue. We report the development of chitosan-collagen scaffolds with micro-pores and an array of parallel channels (~200 μm in diameter) that were specifically designed for cardiac tissue engineering with mechanical stimulation. The scaffolds were designed to have the structural and mechanical properties similar to those of the native human heart matrix. Scaffolds were seeded with neonatal rat heart cells and subjected to dynamic tensile stretch using a custom-designed bioreactor. The channels enhanced oxygen transport and facilitated the establishment of cell connections within the construct. The myocardial patches (14 mm in diameter, 1–2 mm thick) consisted of metabolically active cells and started to contract synchronously after 3 days of culture. Mechanical stimulation with high tensile stresses promoted cell alignment, elongation, and the expression of connexin-43 (Cx-43). This study confirms the importance of scaffold design and mechanical stimulation for the formation of contractile cardiac constructs. PMID:22081518

Channelled scaffolds for engineering myocardium with mechanical stimulation.

PubMed

Zhang, Ting; Wan, Leo Q; Xiong, Zhuo; Marsano, Anna; Maidhof, Robert; Park, Miri; Yan, Yongnian; Vunjak-Novakovic, Gordana

2012-10-01

The characteristics of the matrix (composition, structure, mechanical properties) and external culture environment (pulsatile perfusion, physical stimulation) of the heart are important characteristics in the engineering of functional myocardial tissue. This study reports on the development of chitosan-collagen scaffolds with micropores and an array of parallel channels (~ 200 µm in diameter) that were specifically designed for cardiac tissue engineering using mechanical stimulation. The scaffolds were designed to have similar structural and mechanical properties of those of native heart matrix. Scaffolds were seeded with neonatal rat heart cells and subjected to dynamic tensile stretch using a custom designed bioreactor. The channels enhanced oxygen transport and facilitated the establishment of cell connections within the construct. The myocardial patches (14 mm in diameter, 1-2 mm thick) consisted of metabolically active cells that began to contract synchronously after 3 days of culture. Mechanical stimulation with high tensile stress promoted cell alignment, elongation, and expression of connexin-43 (Cx-43). This study confirms the importance of scaffold design and mechanical stimulation for the formation of contractile cardiac constructs. Copyright © 2011 John Wiley & Sons, Ltd.

Integrated Multidisciplinary Optimization Objects

NASA Technical Reports Server (NTRS)

Alston, Katherine

2014-01-01

OpenMDAO is an open-source MDAO framework. It is used to develop an integrated analysis and design environment for engineering challenges. This Phase II project integrated additional modules and design tools into OpenMDAO to perform discipline-specific analysis across multiple flight regimes at varying levels of fidelity. It also showcased a refined system architecture that allows the system to be less customized to a specific configuration (i.e., system and configuration separation). By delivering a capable and validated MDAO system along with a set of example applications to be used as a template for future users, this work greatly expands NASA's high-fidelity, physics-based MDAO capabilities and enables the design of revolutionary vehicles in a cost-effective manner. This proposed work complements M4 Engineering's expertise in developing modeling and simulation toolsets that solve relevant subsonic, supersonic, and hypersonic demonstration applications.

Computer-aided design of biological circuits using TinkerCell.

PubMed

Chandran, Deepak; Bergmann, Frank T; Sauro, Herbert M

2010-01-01

Synthetic biology is an engineering discipline that builds on modeling practices from systems biology and wet-lab techniques from genetic engineering. As synthetic biology advances, efficient procedures will be developed that will allow a synthetic biologist to design, analyze, and build biological networks. In this idealized pipeline, computer-aided design (CAD) is a necessary component. The role of a CAD application would be to allow efficient transition from a general design to a final product. TinkerCell is a design tool for serving this purpose in synthetic biology. In TinkerCell, users build biological networks using biological parts and modules. The network can be analyzed using one of several functions provided by TinkerCell or custom programs from third-party sources. Since best practices for modeling and constructing synthetic biology networks have not yet been established, TinkerCell is designed as a flexible and extensible application that can adjust itself to changes in the field. © 2010 Landes Bioscience

Sonography on injury of the medial patellofemoral ligament after acute traumatic lateral patellar dislocation: Injury patterns and correlation analysis with injury of articular cartilage of the inferomedial patella.

PubMed

Zhang, Guang-Ying; Zheng, Lei; Shi, Hao; Qu, Su-Hui; Ding, Hong-Yu

2013-12-01

The purpose of this study was to investigate the accuracy of high-frequency ultrasonography in the diagnosis of injuries of medial patellofemoral ligaments (MPFLs), analyse the characteristics of MPFL injury and correlations between injury of the MPFL and articular cartilage of the inferomedial patella in patients with acute traumatic lateral patellar dislocation. High-frequency sonographic images of 49 patients with acute traumatic lateral patellar dislocations treated surgically were reviewed. The χ(2) tests were performed for statistical analysis. Twenty-eight cases of complete MPFL tear and 21 cases of partial MPFL tear were identified in operation, with 27 cases of MPFL tear located at their femoral attachment, 21 cases of tear at the patellar attachment and one case of midsubstance tear. The diagnostic accuracy of sonography regarding partial MPFL tear and complete MPFL tear was 89.8% and 89.8%. Among the patients with MPFL tear at the patellar attachment, eight and six cases were concomitant with chondral and osteochondral lesions in the inferomedial patella, respectively, in contrast to nine and six cases in patients with MPFL tear at the femoral attachment, respectively. There was no significant difference between the two locations described above regarding the prevalence rates of chondral or osteochondral lesions of the inferomedial patella (P=0.732, P=0.614). Among the patients with complete MPFL tear, 12 and 10 cases were concomitant with chondral and osteochondral lesions in the inferomedial patella, respectively, while six and two cases were concomitant with partial MPFL tear. There was no significant difference between the two types of injuries discussed above on the prevalence rates of chondral lesions of the inferomedial patella (P=0.305), but the prevalence rate of osteochondral lesions between the two types of injuries discussed above was statistically different (P=0.035). The MPFL is most easily injured at the femoral attachment, secondly at the patellar attachment. High-frequency ultrasonography is an accurate method in the diagnosis of an MPFL tear. There are neither significant differences on the prevalence rates of chondral or osteochondral lesions of the inferomedial patella between locations of MPFL injuries, nor significant difference on the prevalence rates of chondral lesions between MPFL injury types; but the complete MPFL tear is more often concomitant with inferomedial patellar osteochondral lesions than the partial MPFL tear. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Treatment of Osteochondral Lesions in the Ankle: A Guideline from the Group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU)].

PubMed

Aurich, M; Albrecht, D; Angele, P; Becher, C; Fickert, S; Fritz, J; Müller, P E; Niemeyer, P; Pietschmann, M; Spahn, G; Walther, M

2017-02-01

Background: Osteochondral lesions (OCL) of the ankle are a common cause of ankle pain. Although the precise pathophysiology has not been fully elucidated, it can be assumed that a variety of factors are responsible, mainly including traumatic events such as ankle sprains. Advances in arthroscopy and imaging techniques, in particular magnetic resonance imaging (MRI), have improved the possibilities for the diagnosis of OCLs of the ankle. Moreover, these technologies aim at developing new classification systems and modern treatment strategies. Material and Methods: This article is a review of the literature. Recommendations of the group "Clinical Tissue Regeneration" of the German Society of Orthopaedics and Traumatology (DGOU) for the treatment of OCLs of the ankle are presented. The review gives a concise overview on the results of clinical studies and discusses advantages and disadvantages of different treatment strategies. Results: Non-operative treatment shows good results for selected indications in children and adolescents, especially in early stages of osteochondritis dissecans (OCD). However, surgical treatment is usually indicated in OCLs in adolescents and adults, depending on the size and location of the lesion. Various arthroscopic and open procedures are frequently employed, including reattachment of the fragment, local debridement of the lesion with fragment removal and curettage of the lesion, bone marrow-stimulation by microfracture or microdrilling (antegrade or retrograde), and autologous matrix-induced chondrogenesis (AMIC®) - with or without reconstruction of a subchondral bone defect or cyst by autologous cancellous bone grafting. Isolated subchondral cysts with an intact cartilage surface can be treated by retrograde drilling and possibly additional retrograde bone grafting. For larger defects or as salvage procedure, osteochondral cylinder transplantation (OATS® or Mosaicplasty®) or matrix-induced autologous chondrocyte transplantation (MACT) are recommended. Transplantation of so-called (osteochondral) mega grafts, such as autologous bone grafts or allografts, are used for very large osteochondral defects that cannot be reconstructed otherwise. Implantation of the so-called "small metal implants" - such as HemiCAP Talus® - is reserved for selected cases after failed primary reconstruction. Corrective osteotomies are indicated in accompanying axial malalignments. Conclusions: There are several different treatment strategies for OCLs, but clinical studies are rare and evidence is limited. Therefore, interventional studies, e.g. randomised controlled trials (RCTs), but also observational studies, e.g. based on data of the Cartilage Registry of the German Society of Orthopaedics and Traumatology (www.knorpelregister-dgou.de), are needed and are recommended by the authors. Georg Thieme Verlag KG Stuttgart · New York.

Humeral Head Reconstruction With Osteochondral Allograft Transplantation.

PubMed

Saltzman, Bryan M; Riboh, Jonathan C; Cole, Brian J; Yanke, Adam B

2015-09-01

To synthesize, in a systematic review, the available clinical evidence of osteochondral allograft transplants for large osteochondral defects of the humeral head. The Medline, Embase, and Cochrane databases were searched for studies reporting clinical or radiographic outcomes of osteochondral allograft transplantation for humeral head defects. Descriptive statistics were provided for all outcomes. After checking for data normality, we compared postoperative and preoperative values using the Student t test. We included 12 studies (8 case reports and 4 case series) in this review. The study group consisted of 35 patients. The mean age was 35.4 ± 18.1 years; 77% of patients were male patients. Thirty-three patients had large Hill-Sachs lesions due to instability, 1 had an osteochondritis dissecans lesion, and 1 had an iatrogenic lesion after resection of synovial chondromatosis. The mean lesion size was 3 ± 1.4 cm (anteroposterior) by 2.25 ± 0.3 cm (medial-lateral), representing on average 40.5% ± 4.73% of the native articular surface. Of the 35 patients, 3 received a fresh graft, with all others receiving frozen grafts. Twenty-three femoral heads, 10 humeral heads, and 2 sets of osteochondral plugs were used. The mean length of follow-up was 57 months. Significant improvements were seen in forward flexion at 6 months (68° ± 18.1°, P < .001), forward flexion at 12 months (83.42° ± 18.3°, P < .001), and external rotation at 12 months (38.72° ± 18.8°, P < .001). American Shoulder and Elbow Surgeons scores improved by 14 points (P = .02). Radiographic studies at final follow-up showed allograft necrosis in 8.7% of cases, resorption in 36.2%, and glenohumeral arthritic changes in 35.7%. Complication rates were between 20% and 30%, and the reoperation rate was 26.67%. Although only 3 patients received fresh allografts, there were no reports of graft resorption, necrosis, or arthritic changes in these patients. Humeral head allograft-most commonly used in the setting of large Hill-Sachs lesions due to instability-has shown significant improvements in shoulder motion and American Shoulder and Elbow Surgeons scores as far as 1 year postoperatively. Return-to-work rates and satisfaction levels are high after the intervention. Complication and reoperation rates are substantial, although it is possible that use of fresh allograft tissue may result in less resorption and necrosis. Level V, systematic review of Level IV and V studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

15 CFR 760.3 - Exceptions to prohibitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., a U.S. contractor building an industrial facility in boycotting country Y is asked by B, a resident... agency of boycotting country Y to build a pipeline. Y requests A to suggest qualified engineering firms... conducts its operations, to identify qualified engineering firms to its customers so that its customers may...

15 CFR 760.3 - Exceptions to prohibitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., a U.S. contractor building an industrial facility in boycotting country Y is asked by B, a resident... agency of boycotting country Y to build a pipeline. Y requests A to suggest qualified engineering firms... conducts its operations, to identify qualified engineering firms to its customers so that its customers may...

Inspection planning development: An evolutionary approach using reliability engineering as a tool

NASA Technical Reports Server (NTRS)

Graf, David A.; Huang, Zhaofeng

1994-01-01

This paper proposes an evolutionary approach for inspection planning which introduces various reliability engineering tools into the process and assess system trade-offs among reliability, engineering requirement, manufacturing capability and inspection cost to establish an optimal inspection plan. The examples presented in the paper illustrate some advantages and benefits of the new approach. Through the analysis, reliability and engineering impacts due to manufacturing process capability and inspection uncertainty are clearly understood; the most cost effective and efficient inspection plan can be established and associated risks are well controlled; some inspection reductions and relaxations are well justified; and design feedbacks and changes may be initiated from the analysis conclusion to further enhance reliability and reduce cost. The approach is particularly promising as global competitions and customer quality improvement expectations are rapidly increasing.

Quantitative intact specimen magnetic resonance microscopy at 3.0 T.

PubMed

Bath, Kevin G; Voss, Henning U; Jing, Deqiang; Anderson, Stewart; Hempstead, Barbara; Lee, Francis S; Dyke, Jonathan P; Ballon, Douglas J

2009-06-01

In this report, we discuss the application of a methodology for high-contrast, high-resolution magnetic resonance microscopy (MRM) of murine tissue using a 3.0-T imaging system. We employed a threefold strategy that included customized specimen preparation to maximize image contrast, three-dimensional data acquisition to minimize scan time and custom radiofrequency resonator design to maximize signal sensitivity. Images had a resolution of 100 x 78 x 78 microm(3) with a signal-to-noise ratio per voxel greater than 25:1 and excellent contrast-to-noise ratios over a 30-min acquisition. We quantitatively validated the methods through comparisons of neuroanatomy across two lines of genetically engineered mice. Specifically, we were able to detect volumetric differences of as little as 9% between genetically engineered mouse strains in multiple brain regions that were predictive of underlying impairments in brain development. The overall methodology was straightforward to implement and provides ready access to basic MRM at field strengths that are widely available in both the laboratory and the clinic.

Innovative approach for the in vitro research on biomedical scaffolds designed and customized with CAD-CAM technology.

PubMed

Marrelli, Massimo; Pujia, Antonella; Palmieri, Francesca; Gatto, Roberto; Falisi, Giovanni; Gargari, Marco; Caruso, Silvia; Apicella, Davide; Rastelli, Claudio; Nardi, Gianna Maria; Paduano, Francesco; Tatullo, Marco

2016-12-01

Studies on biomaterials involve assays aimed to assess the interactions between the biomaterial and the cells seeded on its surface. However, the morphology of biomaterials is heterogeneous and it could be tricky to standardize the results among different biomaterials and the classic plastic plates. In this light, we decided to create, by means of computer-aided design (CAD) technology, a standardized sample model, with equal shape and sizes, able to fit into a classic shape of a 96-wells tissue culture plate (TCP). The design of this sample consists of a hole in the top in order to allow the injected cells to settle without them being able to slip from the sides of the sample to the bottom of the TCP wells. This CAD project is made using the software Pro-Engineer. The sample will totally fill the wells of the 96-well TCP. Dental pulp stem cells have been used to assess the ability of the different sample to support and promote the cell proliferation. Twelve titanium, 12 gold-palladium, and 12 zirconium oxide customized samples were designed by means of the software cam powermill, by importing the .stl file created in Pro-Engineer software. The proliferation rate of the tested scaffolds showed to be similar to the control in the group with the customized shape. We think that our method can be useful to test different types of scaffolds when a greater accuracy of the measurements is desirable in order to verify the cell behavior of these scaffolds. Our innovative method can improve the standardization process in the evaluation of cell behavior on different biomaterials to open the way to more reliable tests on biomatrices functionalized with drugs or growth factors applied to the future regenerative medicine. © The Author(s) 2016.

Energy planning and energy efficiency assistance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Markel, L.

1995-12-31

Electrotek is an engineering services company specializing in energy-related programs. Clients are most utilities, large energy users, and the U.S. Electric Power Research Institute. Electrotek has directed energy projects for the U.S. Agency for International Development and the U.S. Department of Energy in Poland and other countries of Central Europe. The objective is to assist the host country organizations to identify and implement appropriate energy efficiency and pollution reduction technologies, to transfer technical and organizational knowledge, so that further implementations are market-driven, without needed continuing foreign investment. Electrotek has worked with the Silesian Power Distribution Company to design an energymore » efficiency program for industrial customers that has proven to be profitable for the company and for its customers. The program has both saved energy and costs, and reduced pollution. The program is expanding to include additional customers, without needing more funding from the U.S. government.« less

A Flexible Electronic Commerce Recommendation System

NASA Astrophysics Data System (ADS)

Gong, Songjie

Recommendation systems have become very popular in E-commerce websites. Many of the largest commerce websites are already using recommender technologies to help their customers find products to purchase. An electronic commerce recommendation system learns from a customer and recommends products that the customer will find most valuable from among the available products. But most recommendation methods are hard-wired into the system and they support only fixed recommendations. This paper presented a framework of flexible electronic commerce recommendation system. The framework is composed by user model interface, recommendation engine, recommendation strategy model, recommendation technology group, user interest model and database interface. In the recommender strategy model, the method can be collaborative filtering, content-based filtering, mining associate rules method, knowledge-based filtering method or the mixed method. The system mapped the implementation and demand through strategy model, and the whole system would be design as standard parts to adapt to the change of the recommendation strategy.

Molecular engineering and measurements to test hypothesized mechanisms in single molecule conductance switching.

PubMed

Moore, Amanda M; Dameron, Arrelaine A; Mantooth, Brent A; Smith, Rachel K; Fuchs, Daniel J; Ciszek, Jacob W; Maya, Francisco; Yao, Yuxing; Tour, James M; Weiss, Paul S

2006-02-15

Six customized phenylene-ethynylene-based oligomers have been studied for their electronic properties using scanning tunneling microscopy to test hypothesized mechanisms of stochastic conductance switching. Previously suggested mechanisms include functional group reduction, functional group rotation, backbone ring rotation, neighboring molecule interactions, bond fluctuations, and hybridization changes. Here, we test these hypotheses experimentally by varying the molecular designs of the switches; the ability of the molecules to switch via each hypothetical mechanism is selectively engineered into or out of each molecule. We conclude that hybridization changes at the molecule-surface interface are responsible for the switching we observe.

Brooklyn Union strategy: Re-engineering from outside in

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, W.P. Jr.

1997-04-01

Five years ago, the management at Brooklyn Union embarked on a long, hard look at the way the company conducted business. In effect, they stepped into their customers` shoes. Business Process Improvement (BPI) is designed to construct a lasting corporate culture that can help Brooklyn Union meet its stated goal of becoming the premier energy company in the Northeast. A major component of that culture involves a dedication to service and cost management that is as solid as their credit ratings. To date, the bottom line on BPI has been impressive: By 1995, the customer satisfaction rating, which had beenmore » hovering in the `80s, had shot up to 95%. The management commitment has come in the form of resources, and a willingness to put its money where its mouth is (rewards for performance). The employee buy-in has shown up in those outstanding ratings from customers and in the financial results. Changing the culture of any long-established entity is never easy, whether it be on the micro-level (a family, for instance) of the macro-level (a country). It involves issues of trust, and a certain leap of faith that the new approach will bring results. Communication and education are two of the keys to gaining that participation. The company was able to impress upon employees the need for change--in particular the need for them to begin thinking like customers. The paper discusses the implementation of this re-engineering strategy.« less

Space Transportation System Availability Requirements and Its Influencing Attributes Relationships

NASA Technical Reports Server (NTRS)

Rhodes, Russel E.; Adams, TImothy C.

2008-01-01

It is essential that management and engineering understand the need for an availability requirement for the customer's space transportation system as it enables the meeting of his needs, goal, and objectives. There are three types of availability, e.g., operational availability, achieved availability, or inherent availability. The basic definition of availability is equal to the mean uptime divided by the sum of the mean uptime plus the mean downtime. The major difference is the inclusiveness of the functions within the mean downtime and the mean uptime. This paper will address tIe inherent availability which only addresses the mean downtime as that mean time to repair or the time to determine the failed article, remove it, install a replacement article and verify the functionality of the repaired system. The definitions of operational availability include the replacement hardware supply or maintenance delays and other non-design factors in the mean downtime. Also with inherent availability the mean uptime will only consider the mean time between failures (other availability definitions consider this as mean time between maintenance - preventive and corrective maintenance) that requires the repair of the system to be functional. It is also essential that management and engineering understand all influencing attributes relationships to each other and to the resultant inherent availability requirement. This visibility will provide the decision makers with the understanding necessary to place constraints on the design definition for the major drivers that will determine the inherent availability, safety, reliability, maintainability, and the life cycle cost of the fielded system provided the customer. This inherent availability requirement may be driven by the need to use a multiple launch approach to placing humans on the moon or the desire to control the number of spare parts required to support long stays in either orbit or on the surface of the moon or mars. It is the intent of this paper to provide the visibility of relationships of these major attribute drivers (variables) to each other and the resultant system inherent availability, but also provide the capability to bound the variables providing engineering the insight required to control the system's engineering solution. An example of this visibility will be the need to provide integration of similar discipline functions to allow control of the total parts count of the space transportation system. Also the relationship visibility of selecting a reliability requirement will place a constraint on parts count to achieve a given inherent availability requirement or accepting a larger parts count with the resulting higher reliability requirement. This paper will provide an understanding for the relationship of mean repair time (mean downtime) to maintainability, e.g., accessibility for repair, and both mean time between failure, e.g., reliability of hardware and the system inherent availability. Having an understanding of these relationships and resulting requirements before starting the architectural design concept definition will avoid considerable time and money required to iterate the design to meet the redesign and assessment process required to achieve the results required of the customer's space transportation system. In fact the impact to the schedule to being able to deliver the system that meets the customer's needs, goals, and objectives may cause the customer to compromise his desired operational goal and objectives resulting in considerable increased life cycle cost of the fielded space transportation system.

Structure Property Studies for Additively Manufactured Parts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milenski, Helen M; Schmalzer, Andrew Michael; Kelly, Daniel

2015-08-17

Since the invention of modern Additive Manufacturing (AM) processes engineers and designers have worked hard to capitalize on the unique building capabilities that AM allows. By being able to customize the interior fill of parts it is now possible to design components with a controlled density and customized internal structure. The creation of new polymers and polymer composites allow for even greater control over the mechanical properties of AM parts. One of the key reasons to explore AM, is to bring about a new paradigm in part design, where materials can be strategically optimized in a way that conventional subtractivemore » methods cannot achieve. The two processes investigated in my research were the Fused Deposition Modeling (FDM) process and the Direct Ink Write (DIW) process. The objectives of the research were to determine the impact of in-fill density and morphology on the mechanical properties of FDM parts, and to determine if DIW printed samples could be produced where the filament diameter was varied while the overall density remained constant.« less

Evolving Dispensers: How to Take Benefit from Heritage

NASA Astrophysics Data System (ADS)

Veilleraud, Fredderic; Larcher, Virginie

2014-06-01

Thanks to its large know-how in the field of accommodation and launch of multiple payloads on civil and military programs, Airbus Defence and Space has developed since 1996 dispensers for various constellations on various launchers.Taking into account time and cost constraints of this market, Airbus D&S early based its solutions on adaptation of previous products enabling to limit engineering and manufacturing effort. Thus, Airbus D&S has developed a family of prequalified technological elements allowing adaptation of design to requirement while limiting drastically qualification need.Doing that, Airbus Defence and Space has also gathered a strong experience on various primary concepts that could be easily tuned and customized to new customer needs.

Helicopter Acoustics

NASA Technical Reports Server (NTRS)

1978-01-01

Exterior and interior noise problems are addressed both from the physics and engineering as well as the human factors point of view. The role of technology in closing the gap between what the customers and regulating agencies would like to have and what is available is explored. Noise regulation concepts, design, operations and testing for noise control, helicopter noise prediction, and research tools and measurements are among the topics covered.

Inside Real Innovation

DTIC Science & Technology

2011-11-01

whether it is a purchasing manager , a design engineer or a manufacturing line operator. It is not necessary for the customer at the end of the supply...transactional experiences, which usually involve talking to people. For example, a conversation with a manufacturing manager about whether he is concerned about...Innovations require experimenting with greater uncertainty in Technology, Market and Implementation. The owner cuts her own pay in order to hire a manager

The MSFC Systems Engineering Guide: An Overview and Plan

NASA Technical Reports Server (NTRS)

Shelby, Jerry A.; Thomas, L. Dale

2007-01-01

As systems and subsystems requirements become more complex in the pursuit of the exploration of space, advanced technology will demand and require an integrated approach to the design and development of safe and successful space vehicles and there products. System engineers play a vital and key role in transforming mission needs into vehicle requirements that can be verified and validated. This will result in a safe and cost effective design that will satisfy the mission schedule. A key to successful vehicle design within systems engineering is communication. Communication, through a systems engineering infrastructure, will not only ensure that customers and stakeholders are satisfied but will also assist in identifying vehicle requirements; i.e. identification, integration and management. This vehicle design will produce a system that is verifiable, traceable, and effectively satisfies cost, schedule, performance, and risk throughout the life-cycle of the product. A communication infrastructure will bring about the integration of different engineering disciplines within vehicle design. A system utilizing these aspects will enhance system engineering performance and improve upon required activities such as Development of Requirements, Requirements Management, Functional Analysis, Test, Synthesis, Trade Studies, Documentation, and Lessons Learned to produce a successful final product. This paper will describe the guiding vision, progress to date and the plan forward for development of the Marshall Space Flight Center (MSFC) Systems Engineering Guide (SEG), a virtual systems engineering handbook and archive that will describe the system engineering processes that are used by MSFC in the development of complex systems such as the Ares launch vehicle. It is the intent of this website to be a "One Stop Shop" for our systems engineers that will provide tutorial information, an overview of processes and procedures and links to assist system engineering with guidance and references, and provide an archive of systems engineering artifacts produced by the many NASA projects developed and managed by MSFC over the years.

Key Decision Record Creation and Approval Module

NASA Technical Reports Server (NTRS)

Hebert, Barrt; Messer, Elizabeth A.; Albasini, Colby; Le, Thang; ORourke, William, Sr.; Stiglets, Tim; Strain, Ted

2012-01-01

Retaining good key decision records is critical to ensuring the success of a project or operation. Having adequately documented decisions with supporting documents and rationale can greatly reduce the amount of rework or reinvention over a project's, vehicle's, or facility's lifecycle. Stennis Space Center developed and uses a software tool that automates the Key Decision Record (KDR) process for its engineering and test projects. It provides the ability for a user to log key decisions that are made during the course of a project. By customizing Parametric Technology Corporation's (PTC) Windchill product, the team was able to log all information about a decision, and electronically route that information for approval. Customizing the Windchill product allowed the team to directly connect these decisions to the engineering data that it might affect and notify data owners of the decision. The user interface was created in JSP and Javascript, within the OOTB (Out of the Box) Windchill product, allowing users to create KDRs. Not only does this interface allow users to create and track KDRs, but it also plugs directly into the OOTB ability to associate these decision records with other relevant engineering data such as drawings, designs, models, requirements, or specifications

Fabrication of Custom-Shaped Grafts for Cartilage Regeneration

PubMed Central

Koo, Seungbum; Hargreaves, Brian A.; Gold, Garry E.; Dragoo, Jason L.

2011-01-01

Transplantation of engineered cartilage grafts is a promising method to treat diseased articular cartilage. The interfacial areas between the graft and the native tissues play an important role in the successful integration of the graft to adjacent native tissues. The purposes of the study were to create a custom shaped graft through 3D tissue shape reconstruction and rapid-prototype molding methods using MRI data, and to test the accuracy of the custom shaped graft against the original anatomical defect. An iatrogenic defect on the distal femur was identified with a 1.5 Tesla MRI and its shape was reconstructed into a three-dimensional (3D) computer model by processing the 3D MRI data. First, the accuracy of the MRI-derived 3D model was tested against a laser-scan based 3D model of the defect. A custom-shaped polyurethane graft was fabricated from the laser-scan based 3D model by creating custom molds through computer aided design and rapid-prototyping methods. The polyurethane tissue was laser-scanned again to calculate the accuracy of this process compared to the original defect. The volumes of the defect models from MRI and laser-scan were 537 mm3 and 405 mm3, respectively, implying that the MRI model was 33% larger than the laser-scan model. The average (±SD) distance deviation of the exterior surface of the MRI model from the laser-scan model was 0.4±0.4 mm. The custom-shaped tissue created from the molds was qualitatively very similar to the original shape of the defect. The volume of the custom-shaped cartilage tissue was 463 mm3 which was 15% larger than the laser-scan model. The average (±SD) distance deviation between the two models was 0.04±0.19 mm. Custom-shaped engineered grafts can be fabricated from standard sequence 3-D MRI data with the use of CAD and rapid-prototyping technology, which may help solve the interfacial problem between native cartilage and graft, if the grafts are custom made for the specific defect. The major source of error in fabricating a 3D custom shaped cartilage graft appears to be the accuracy of a MRI data itself; however, the precision of the model is expected to increase by the utilization of advanced MR sequences with higher magnet strengths. PMID:21058268

MicroShell Minimalist Shell for Xilinx Microprocessors

NASA Technical Reports Server (NTRS)

Werne, Thomas A.

2011-01-01

MicroShell is a lightweight shell environment for engineers and software developers working with embedded microprocessors in Xilinx FPGAs. (MicroShell has also been successfully ported to run on ARM Cortex-M1 microprocessors in Actel ProASIC3 FPGAs, but without project-integration support.) Micro Shell decreases the time spent performing initial tests of field-programmable gate array (FPGA) designs, simplifies running customizable one-time-only experiments, and provides a familiar-feeling command-line interface. The program comes with a collection of useful functions and enables the designer to add an unlimited number of custom commands, which are callable from the command-line. The commands are parameterizable (using the C-based command-line parameter idiom), so the designer can use one function to exercise hardware with different values. Also, since many hardware peripherals instantiated in FPGAs have reasonably simple register-mapped I/O interfaces, the engineer can edit and view hardware parameter settings at any time without stopping the processor. MicroShell comes with a set of support scripts that interface seamlessly with Xilinx's EDK tool. Adding an instance of MicroShell to a project is as simple as marking a check box in a library configuration dialog box and specifying a software project directory. The support scripts then examine the hardware design, build design-specific functions, conditionally include processor-specific functions, and complete the compilation process. For code-size constrained designs, most of the stock functionality can be excluded from the compiled library. When all of the configurable options are removed from the binary, MicroShell has an unoptimized memory footprint of about 4.8 kB and a size-optimized footprint of about 2.3 kB. Since MicroShell allows unfettered access to all processor-accessible memory locations, it is possible to perform live patching on a running system. This can be useful, for instance, if a bug is discovered in a routine but the system cannot be rebooted: Shell allows a skilled operator to directly edit the binary executable in memory. With some forethought, MicroShell code can be located in a different memory location from custom code, permitting the custom functionality to be overwritten at any time without stopping the controlling shell.

Revisiting software specification and design for large astronomy projects

NASA Astrophysics Data System (ADS)

Wiant, Scott; Berukoff, Steven

2016-07-01

The separation of science and engineering in the delivery of software systems overlooks the true nature of the problem being solved and the organization that will solve it. Use of a systems engineering approach to managing the requirements flow between these two groups as between a customer and contractor has been used with varying degrees of success by well-known entities such as the U.S. Department of Defense. However, treating science as the customer and engineering as the contractor fosters unfavorable consequences that can be avoided and opportunities that are missed. For example, the "problem" being solved is only partially specified through the requirements generation process since it focuses on detailed specification guiding the parties to a technical solution. Equally important is the portion of the problem that will be solved through the definition of processes and staff interacting through them. This interchange between people and processes is often underrepresented and under appreciated. By concentrating on the full problem and collaborating on a strategy for its solution a science-implementing organization can realize the benefits of driving towards common goals (not just requirements) and a cohesive solution to the entire problem. The initial phase of any project when well executed is often the most difficult yet most critical and thus it is essential to employ a methodology that reinforces collaboration and leverages the full suite of capabilities within the team. This paper describes an integrated approach to specifying the needs induced by a problem and the design of its solution.

Engineering design of the PLX- α coaxial gun

NASA Astrophysics Data System (ADS)

Cruz, Edward; Brockington, Samuel; Case, Andrew; Luna, Marco; Witherspoon, Douglas; Langendorf, Samuel

2016-10-01

We describe the engineering and technical aspects of the coaxial gun designed for the 60-gun scaling study of spherically imploding plasma liners as a standoff driver for plasma-jet-driven magneto-inertial fusion. Each coaxial gun incorporates a fast, dense gas injection and triggering system, a compact low-weight pfn with integral sparkgap switching, and a contoured gap designed to suppress the blow-by instability. Alpha1 and Alpha2 guns are compared, with emphasis on the improvements on Alpha2, which include a faster more robust gas valve, an improved electrode contour, a custom 600- μF, 5-kV pfn, and a set of six inline sparkgap switches operated in parallel. The switch and pfn configurations are mounted directly to the back of the gun, and are designed to reduce inductance, cost, and complexity, maximize efficiency and system reliability, and ensure symmetric current flow. We will provide a detailed overview of the design choices made for the PLX- α coaxial gun. This work supported by the ARPA-E ALPHA Program.

Onyx-Advanced Aeropropulsion Simulation Framework Created

NASA Technical Reports Server (NTRS)

Reed, John A.

2001-01-01

The Numerical Propulsion System Simulation (NPSS) project at the NASA Glenn Research Center is developing a new software environment for analyzing and designing aircraft engines and, eventually, space transportation systems. Its purpose is to dramatically reduce the time, effort, and expense necessary to design and test jet engines by creating sophisticated computer simulations of an aerospace object or system (refs. 1 and 2). Through a university grant as part of that effort, researchers at the University of Toledo have developed Onyx, an extensible Java-based (Sun Micro-systems, Inc.), objectoriented simulation framework, to investigate how advanced software design techniques can be successfully applied to aeropropulsion system simulation (refs. 3 and 4). The design of Onyx's architecture enables users to customize and extend the framework to add new functionality or adapt simulation behavior as required. It exploits object-oriented technologies, such as design patterns, domain frameworks, and software components, to develop a modular system in which users can dynamically replace components with others having different functionality.

Developing a search engine for pharmacotherapeutic information that is not published in biomedical journals.

PubMed

Do Pazo-Oubiña, F; Calvo Pita, C; Puigventós Latorre, F; Periañez-Párraga, L; Ventayol Bosch, P

2011-01-01

To identify publishers of pharmacotherapeutic information not found in biomedical journals that focuses on evaluating and providing advice on medicines and to develop a search engine to access this information. Compiling web sites that publish information on the rational use of medicines and have no commercial interests. Free-access web sites in Spanish, Galician, Catalan or English. Designing a search engine using the Google "custom search" application. Overall 159 internet addresses were compiled and were classified into 9 labels. We were able to recover the information from the selected sources using a search engine, which is called "AlquimiA" and available from http://www.elcomprimido.com/FARHSD/AlquimiA.htm. The main sources of pharmacotherapeutic information not published in biomedical journals were identified. The search engine is a useful tool for searching and accessing "grey literature" on the internet. Copyright © 2010 SEFH. Published by Elsevier Espana. All rights reserved.

NASA Lewis Wind Tunnel Model Systems Criteria

NASA Technical Reports Server (NTRS)

Soeder, Ronald H.; Haller, Henry C.

1994-01-01

This report describes criteria for the design, analysis, quality assurance, and documentation of models or test articles that are to be tested in the aeropropulsion facilities at the NASA Lewis Research Center. The report presents three methods for computing model allowable stresses on the basis of the yield stress or ultimate stress, and it gives quality assurance criteria for models tested in Lewis' aeropropulsion facilities. Both customer-furnished model systems and in-house model systems are discussed. The functions of the facility manager, project engineer, operations engineer, research engineer, and facility electrical engineer are defined. The format for pretest meetings, prerun safety meetings, and the model criteria review are outlined Then, the format for the model systems report (a requirement for each model that is to be tested at NASA Lewis) is described, the engineers that are responsible for developing the model systems report are listed, and the time table for its delivery to the facility manager is given.

Ex vivo model unravelling cell distribution effect in hydrogels for cartilage repair.

PubMed

Mouser, Vivian H M; Dautzenberg, Noël M M; Levato, Riccardo; van Rijen, Mattie H P; Dhert, Wouter J A; Malda, Jos; Gawlitta, Debby

2018-01-01

The implantation of chondrocyte-laden hydrogels is a promising cartilage repair strategy. Chondrocytes can be spatially positioned in hydrogels and thus in defects, while current clinical cell therapies introduce chondrocytes in the defect depth. The main aim of this study was to evaluate the effect of spatial chondrocyte distribution on the reparative process. To reduce animal experiments, an ex vivo osteochondral plug model was used and evaluated. The role of the delivered and endogenous cells in the repair process was investigated. Full thickness cartilage defects were created in equine osteochondral plugs. Defects were filled with (A) chondrocytes at the bottom of the defect, covered with a cell-free hydrogel, (B) chondrocytes homogeneously encapsulated in a hydrogel, and (C, D) combinations of A and B with different cell densities. Plugs were cultured for up to 57 days, after which the cartilage and repair tissues were characterized and compared to baseline samples. Additionally, at day 21, the origin of cells in the repair tissue was evaluated. Best outcomes were obtained with conditions C and D, which resulted in well-integrated cartilage-like tissue that completely filled the defect, regardless of the initial cell density. A critical role of the spatial chondrocyte distribution in the repair process was observed. Moreover, the osteochondral plugs stimulated cartilage formation in the hydrogels when cultured in the defects. The resulting repair tissue originated from the delivered cells. These findings confirm the potential of the osteochondral plug model for the optimization of the composition of cartilage implants and for studying repair mechanisms.

Regeneration of hyaline cartilage promoted by xenogeneic mesenchymal stromal cells embedded within elastin-like recombinamer-based bioactive hydrogels.

PubMed

Pescador, David; Ibáñez-Fonseca, Arturo; Sánchez-Guijo, Fermín; Briñón, Jesús G; Arias, Francisco Javier; Muntión, Sandra; Hernández, Cristina; Girotti, Alessandra; Alonso, Matilde; Del Cañizo, María Consuelo; Rodríguez-Cabello, José Carlos; Blanco, Juan Francisco

2017-08-01

Over the last decades, novel therapeutic tools for osteochondral regeneration have arisen from the combination of mesenchymal stromal cells (MSCs) and highly specialized smart biomaterials, such as hydrogel-forming elastin-like recombinamers (ELRs), which could serve as cell-carriers. Herein, we evaluate the delivery of xenogeneic human MSCs (hMSCs) within an injectable ELR-based hydrogel carrier for osteochondral regeneration in rabbits. First, a critical-size osteochondral defect was created in the femora of the animals and subsequently filled with the ELR-based hydrogel alone or with embedded hMSCs. Regeneration outcomes were evaluated after three months by gross assessment, magnetic resonance imaging and computed tomography, showing complete filling of the defect and the de novo formation of hyaline-like cartilage and subchondral bone in the hMSC-treated knees. Furthermore, histological sectioning and staining of every sample confirmed regeneration of the full cartilage thickness and early subchondral bone repair, which was more similar to the native cartilage in the case of the cell-loaded ELR-based hydrogel. Overall histological differences between the two groups were assessed semi-quantitatively using the Wakitani scale and found to be statistically significant (p < 0.05). Immunofluorescence against a human mitochondrial antibody three months post-implantation showed that the hMSCs were integrated into the de novo formed tissue, thus suggesting their ability to overcome the interspecies barrier. Hence, we conclude that the use of xenogeneic MSCs embedded in an ELR-based hydrogel leads to the successful regeneration of hyaline cartilage in osteochondral lesions.

Return to running following knee osteochondral repair using an anti-gravity treadmill: A case report.

PubMed

Hambly, Karen; Poomsalood, Somruthai; Mundy, Emma

2017-07-01

The purpose of this study was to assess the impact of an anti-gravity treadmill return to running programme on self-efficacy and subjective knee function following knee osteochondral surgery. A 39-year-old otherwise healthy female endurance runner with a left knee femoral cartilage grade 3-4 defect 3 cm 2 . The patient underwent single step arthroscopic microfracture with Bone Marrow Aspirate Concentrate. An AlterG ® anti-gravity treadmill was used to manipulate loading during a graduated phased return to running over 8 weeks. Self-efficacy was evaluated using the Self-Efficacy for Rehabilitation outcomes scale (SER) and the Knee Self-Efficacy Scale (K-SES). Subjective knee function was evaluated using the Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee Subjective Knee Form (IKDC). The programme resulted in improvements in SER (57%), K-SES present (89%) and K-SES future (65%) self-efficacy domains. The IKDC score demonstrated a clinically important improvement with an increase from 62.1 in week 1-86.2 in week 8 (39%). Only the KOOS Sport/Rec subscale showed a clinically important improvement from week 1 to week 8. The programme resulted in improved knee and rehabilitation self-efficacy and subjective knee function following osteochondral repair of the knee. This case report illustrates the importance of considering self-efficacy in rehabilitation after knee osteochondral surgery and highlights the potential role for anti-gravity treadmills in enhancing self-efficacy and subjective knee function in preparation for a return to sport. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

The Use of Osteochondral Allograft Transplantation for Primary Treatment of Cartilage Lesions in the Knee.

PubMed

Briggs, Dustin T; Sadr, Kamran N; Pulido, Pamela A; Bugbee, William D

2015-10-01

To assess the outcome of osteochondral allograft (OCA) transplantation as the primary treatment for cartilage injury in patients with no previous surgical treatment. Case series. Patients were identified in our outcomes database. Patients undergoing primary OCA transplantation with no prior surgical treatment and a minimum of 2 years follow-up were selected. Pain and function were evaluated preoperatively and postoperatively. Patient satisfaction was assessed. Reoperations following OCA transplantation were captured. Failure was defined as revision OCA or conversion to arthroplasty. Fifty-five patients (61 knees) were included in the analysis. The study consisted of 30 males and 25 females (mean age = 32.9 years; range = 15.7-67.8 years). The most common diagnoses for the OCA transplantation were osteochondritis dissecans (44.3%) and avascular necrosis (31.1%). Pain and function improved preoperatively to postoperatively on all outcome scales (P < 0.01). The majority of patients (86%) were "extremely satisfied" or "satisfied." OCA survivorship was 89.5% at 5 years and 74.7% at 10 years. At latest follow-up (mean = 7.6 years; range = 1.9-22.6 years), OCA remained in situ in 50 knees (82%). Eighteen knees (29.5%) had further surgery; 11 OCA failures and 7 other surgical procedure(s). Of the failed knees (mean time to failure = 3.5 years; range = 0.5-13.7 years), 8 were converted to arthroplasty, 2 had OCA revisions, and 1 had a patellectomy. OCA transplantation is an acceptable primary treatment method for some chondral and osteochondral defects of the knee. Failure of previous treatment(s) is not a prerequisite for OCA transplantation.

Get inside the lives of your customers.

PubMed

Seybold, P B

2001-05-01

Many companies have become adept at the art of customer relationship management. They've collected mountains of data on preferences and behavior, divided buyers into ever-finer segments, and refined their products, services, and marketing pitches. But all too often those efforts are too narrow--they concentrate only on the points where the customer comes into contact with the company. Few businesses have bothered to look at what the author calls the customer scenario--the broad context in which customers select, buy, and use products and services. As a result, consultant Patricia Seybold maintains, they've routinely missed chances to deepen loyalty and expand sales. In this article, the author shows how effective three very different companies have been at using customer scenarios as the centerpiece of their marketing plans. Chip maker National Semiconductor looked beyond the purchasing agents that buy in bulk to find ways to make it easier for engineers to design National's components into their specifications for mobile telephones. Each time they do so, it translates into millions of dollars in orders. By developing a customer scenario that describes how people actually shop for groceries, Tesco learned the importance of decentralizing its Web shopping site and how the extra costs of decentralization could be outweighed by the higher profit margins on-line customers generate. And Buzzsaw.com used customer scenarios as the basis for its entire business. It has used the Web to create a better way for the dozens of participants in a construction project to share their drawings and manage their projects. Seybold lays out the steps managers can take to develop their own customer scenarios. By thinking broadly about the challenges your customers face, she suggests, you can almost always find ways to make their lives easier--and thus earn their loyalty.

Re-Engineering Complex Legacy Systems at NASA

NASA Technical Reports Server (NTRS)

Ruszkowski, James; Meshkat, Leila

2010-01-01

The Flight Production Process (FPP) Re-engineering project has established a Model-Based Systems Engineering (MBSE) methodology and the technological infrastructure for the design and development of a reference, product-line architecture as well as an integrated workflow model for the Mission Operations System (MOS) for human space exploration missions at NASA Johnson Space Center. The design and architectural artifacts have been developed based on the expertise and knowledge of numerous Subject Matter Experts (SMEs). The technological infrastructure developed by the FPP Re-engineering project has enabled the structured collection and integration of this knowledge and further provides simulation and analysis capabilities for optimization purposes. A key strength of this strategy has been the judicious combination of COTS products with custom coding. The lean management approach that has led to the success of this project is based on having a strong vision for the whole lifecycle of the project and its progress over time, a goal-based design and development approach, a small team of highly specialized people in areas that are critical to the project, and an interactive approach for infusing new technologies into existing processes. This project, which has had a relatively small amount of funding, is on the cutting edge with respect to the utilization of model-based design and systems engineering. An overarching challenge that was overcome by this project was to convince upper management of the needs and merits of giving up more conventional design methodologies (such as paper-based documents and unwieldy and unstructured flow diagrams and schedules) in favor of advanced model-based systems engineering approaches.

Customer Satisfaction with Air Force Civil Engineering Support

DTIC Science & Technology

1988-09-01

Regulation aS-l states, "No other base organization directly affects the living environment of every person on base as does the BCE (Base Civil Engineering...accounting, engineering, and legal firms; personal services such as housekeeping, barbering, and recreational services; and most of the nonprofit areas of...a single package via Lear jet to keep a promise to a customer" (Lele, 1987: 45). Frito Lay maintains a 10,000 person sales force in what is a

NASA's MERBoard: An Interactive Collaborative Workspace Platform. Chapter 4

NASA Technical Reports Server (NTRS)

Trimble, Jay; Wales, Roxana; Gossweiler, Rich

2003-01-01

This chapter describes the ongoing process by which a multidisciplinary group at NASA's Ames Research Center is designing and implementing a large interactive work surface called the MERBoard Collaborative Workspace. A MERBoard system involves several distributed, large, touch-enabled, plasma display systems with custom MERBoard software. A centralized server and database back the system. We are continually tuning MERBoard to support over two hundred scientists and engineers during the surface operations of the Mars Exploration Rover Missions. These scientists and engineers come from various disciplines and are working both in small and large groups over a span of space and time. We describe the multidisciplinary, human-centered process by which this h4ERBoard system is being designed, the usage patterns and social interactions that we have observed, and issues we are currently facing.

[Osteochondral lesions of the talar dome: surgical treatment in a series of 30 cases].

PubMed

Jarde, O; Trinquier-Lautard, J L; Garate, F; de Lestang, M; Vives, P

2000-10-01

We reviewed 30 cases of osteochondral lesions of the astragalar vault treated surgically. Among the 30 patients, 17 participated in sports activities and 24 had a history of trauma. Mean delay to surgery was 10 months. Treatment included osteochondritis curettage and Pridie perforations. Direct access was used in 11 cases, malleolar osteotomy in 13 and arthroscopy in 6. Cancellous bone grafts were used in 6 cases. Mean follow-up was 3 years 7 months (minimum 2 years). All patients had an arthroscan at last follow-up. Evaluation of post-operative outcome was based on clinical assessment and arthroscan findings. Surgical treatment provided very good results in 75 p. 100 of cases with pain relief and improved walking distance. Our cases pointed out the important contribution of the FOG (Fracture Osteonecrosis Geode) classification to pathogenic and prognostic analysis. The Berndt and Harty classifications were not found to be useful. In case of localized necrosis, we propose arthroscopic perforation curettage. In case of bone loss, a direct cancellous graft may be used.

The use of osteochondral allograft with bone marrow-derived mesenchymal cells and hinge joint distraction in the treatment of post-collapse stage of osteonecrosis of the femoral head.

PubMed

Gagala, J; Tarczynska, M; Gaweda, K; Matuszewski, L

2014-09-01

Osteonecrosis of the femoral head is an entity which occurs mainly in young and active patients aged between 20 and 50. The success of hip joint preserving treatments ranges from 15% to 50% depending on the stage and amount of osteonecrotic lesion. Total hip replacement is indicated in late post-collapse hips but it has unsatisfactory survival because of the wear and osteolysis in young and active patients. Osteochondral allografts have been reported in the treatment of large articular lesions with defects in underlying bone in knee, talus and shoulder. By combining osteoconductive properties of osteochondral allograft with osteogenic abilities of bone marrow-derived mesenchymal cells it has a potential to be an alternative to an autologous graft. The adjunct of hinged joint distraction should minimize stresses in subchondral bone to promote creeping substitution and prevent femoral head collapse. Unlike current treatment modalities, it would provide both structural support and allow bony and articular substitution. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Integration of COTS/GOTS within NASA's HST Command and Control System

NASA Technical Reports Server (NTRS)

Pfarr, Thomas; Reis, James E.

2001-01-01

NASA's mission critical Hubble Space Telescope (HST) command and control system has been re-engineered with commercial-off-the-shelf (COTS/GOTS) and minimal custom code. This paper focuses on the design of this new HST Control Center System (CCS) and the lessons learned throughout its development. CCS currently utilizes more than 30 COTS/GOTS products with an additional 1/2 million lines of custom glueware code; the new CCS exceeds the capabilities of the original system while significantly reducing the lines of custom code by more than 50%. The lifecycle of COTS/GOTS products will be examined including the package selection process, evaluation process, and integration process. The advantages, disadvantages, issues, concerns, and lessons learned for integrating COTS/GOTS into the NASA's mission critical HST CCS will be examined in detail. This paper will reveal the many hidden costs of COTS/GOTS solutions when compared to traditional custom code development efforts; this paper will show the high cost of COTS/GOTS solutions including training expenses, consulting fees, and long-term maintenance expenses.

Guide to Using Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Ryan Phillip; Agelastos, Anthony Michael; Miller, Joel D.

2015-03-01

Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

Guide to Using Sierra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaw, Ryan Phillip; Agelastos, Anthony Michael; Miller, Joel D.

2017-04-01

Sierra is an engineering mechanics simulation code suite supporting the Nation's Nuclear Weapons mission as well as other customers. It has explicit ties to Sandia National Labs' workfow, including geometry and meshing, design and optimization, and visualization. Dis- tinguishing strengths include "application aware" development, scalability, SQA and V&V, multiple scales, and multi-physics coupling. This document is intended to help new and existing users of Sierra as a user manual and troubleshooting guide.

Customer requirements process

NASA Technical Reports Server (NTRS)

Russell, Yvonne; Falsetti, Christine M.

1991-01-01

Customer requirements are presented through three viewgraphs. One graph presents the range of services, which include requirements management, network engineering, operations, and applications support. Another viewgraph presents the project planning process. The third viewgraph presents the programs and/or projects actively supported including life sciences, earth science and applications, solar system exploration, shuttle flight engineering, microgravity science, space physics, and astrophysics.

The Evolution of Inquiry Activities in the Akamai Observatory Short Course, 2004-2009

NASA Astrophysics Data System (ADS)

Rice, E. L.; McElwain, M.; Sonnett, S.; Rafelski, M.

2010-12-01

The Akamai Observatory Short Course (AOSC) is a five-day course of activities designed to prepare college students majoring in science, technology, engineering, and mathematics (STEM) fields for internships at observatories on the Big Island of Hawai'i. The design and implementation of inquiry-based activities in the AOSC have evolved considerably over the six years of the course. The content goals have always focused on the basic understanding of light and optics necessary to understand telescopes, but the scientific process goals gradually evolved to reflect the increasingly recognized importance of engineering design skills for successful observatory internships. In 2004 the inquiry-based activities were limited to one well-established Color, Light, and Spectra activity. In subsequent years more activities were customized and expanded upon to reflect the learners' diverse academic backgrounds, the developing goals of the short course, and feedback from internship hosts. The most recent inquiry, the Design and Build a Telescope activity, engaged students in designing and building a simple telescope, emphasizing science and engineering process skills in addition to science content. This activity was influenced by the Mission Design activity, added in 2006, that incorporated the application of inquiry-based learning to the engineering design process and allowed students to draw upon their diverse prior knowledge and experience. In this paper we describe the inquiry-based activities in the AOSC in the context of its year-to-year evolution, including the conceptual and pragmatic changes to the short course that influenced the evolution.

Right Fronto-Temporal EEG can Differentiate the Affective Responses to Award-Winning Advertisements.

PubMed

Wang, Regina W Y; Huarng, Shy-Peih; Chuang, Shang-Wen

2018-04-01

Affective engineering aims to improve service/product design by translating the customer's psychological feelings. Award-winning advertisements (AAs) were selected on the basis of the professional standards that consider creativity as a prerequisite. However, it is unknown if AA is related to satisfactory advertising performance among customers or only to the experts' viewpoints towards the advertisements. This issue in the field of affective engineering and design merits in-depth evaluation. We recruited 30 subjects and performed an electroencephalography (EEG) experiment while watching AAs and non-AAs (NAAs). The event-related potential (ERP) data showed that AAs evoked larger positive potentials 250-1400 [Formula: see text]ms after stimulus onset, particularly in the right fronto-temporal regions. The behavioral results were consistent with the professional recognition given to AAs by experts. The perceived levels of creativity and "product-like" quality were higher for the AAs than for the NAAs. Event-related spectral perturbation (ERSP) analysis further revealed statistically significant differences in the theta, alpha, beta, and gamma band activity in the right fronto-temporal regions between the AAs and NAAs. Our results confirm that EEG features from the time/frequency domains can differentiate affective responses to AAs at a neural circuit level, and provide scientific evidence to support the identification of AAs.

Energy Return On Investment of Engineered Geothermal Systems Data

DOE Data Explorer

Mansure, Chip

2012-01-01

The project provides an updated Energy Return on Investment (EROI) for Enhanced Geothermal Systems (EGS). Results incorporate Argonne National Laboratory's Life Cycle Assessment and base case assumptions consistent with other projects in the Analysis subprogram. EROI is a ratio of the energy delivered to the consumer to the energy consumed to build, operate, and decommission the facility. EROI is important in assessing the viability of energy alternatives. Currently EROI analyses of geothermal energy are either out-of-date, of uncertain methodology, or presented online with little supporting documentation. This data set is a collection of files documenting data used to calculate the Energy Return On Investment (EROI) of Engineered Geothermal Systems (EGS) and erratum to publications prior to the final report. Final report is available from the OSTI web site (http://www.osti.gov/geothermal/). Data in this collections includes the well designs used, input parameters for GETEM, a discussion of the energy needed to haul materials to the drill site, the baseline mud program, and a summary of the energy needed to drill each of the well designs. EROI is the ratio of the energy delivered to the customer to the energy consumed to construct, operate, and decommission the facility. Whereas efficiency is the ratio of the energy delivered to the customer to the energy extracted from the reservoir.

Different osteochondral potential of clonal cell lines derived from adult human trabecular bone.

PubMed

Osyczka, Anna M; Nöth, Ulrich; Danielson, Keith G; Tuan, Rocky S

2002-06-01

Cells derived from human trabecular bones have been shown to have multipotential differentiation ability along osteogenic, chondrogenic, and adipogenic lineages. In this study, we have derived two clonal sublines of human trabecular bone cells by means of stable transduction with human papilloma virus E6/E7 genes. Our results showed that these clonal sublines differ in their osteochondral potential, but are equally adipogenic, indicative of the heterogeneous nature of the parental cell population. The availability of these cell lines should be useful for the analysis of the mechanisms regulating the differentiation of adult mesenchymal progenitor cells.

[Experimental study on loading naringin composite scaffolds for repairing rabbit osteochondral defects].

PubMed

Huang, Junbo; Wang, Shiyong; Zhang, Xiaomin; Li, Gen; Ji, Puzhong; Zhao, Hongbin

2017-04-01

To investigate the performance of loading naringin composite scaffolds and its effects on repair of osteochondral defects. The loading naringin and unloading naringin sustained release microspheres were prepared by W/O/W method; with the materials of the attpulgite and the collagen type I, the loading naringin, unloading naringin, and loading transforming growth factor β 1 (TGF-β 1 ) osteochondral composite scaffolds were constructed respectively by "3 layers sandwich method". The effect of sustained-release of loading naringin microspheres, the morphology of the composite scaffolds, and the biocompatibility were evaluated respectively by releasing in vitro , scanning electron microscope, and cell counting kit 8. Forty Japanese white rabbits were randomly divided into groups A, B, C, and D, 10 rabbits each group. After a osteochondral defect of 4.5 mm in diameter and 4 mm in depth was made in the intercondylar fossa of two femurs. Defect was not repaired in group A (blank control), and defect was repaired with unloading naringin composite scaffolds (negative control group), loading naringin composite scaffolds (experimental group), and loading TGF-β 1 composite scaffolds (positive control group) in groups B, C, and D respectively. At 3 and 6 months after repair, the intercondylar fossa was harvested for the general, HE staining, and toluidine blue staining to observe the repair effect. Western blot was used to detect the expression of collagen type II in the new cartilage. Loading naringin microspheres had good effect of sustained-release; the osteochondral composite scaffolds had good porosity; the cell proliferation rate on loading naringin composite scaffold was increased significantly when compared with unloading naringin scaffold ( P <0.05). General observation revealed that defect range of groups C and D was reduced significantly when compared with groups A and B at 3 months after repair; at 6 months after repair, defects of group C were covered by new cartilage, and new cartilage well integrated with the adjacent cartilage in group D. The results of histological staining revealed that defects were filled with a small amount of fibrous tissue in groups A and B, and a small amount of new cartilage in groups C and D at 3 months after repair; new cartilage of groups C and D was similar to normal cartilage, but defects were filled with a large amount of fibrous tissue in groups A and B at 6 months after repair. The expression of collagen type II in groups C and D was significantly higher than that in groups A and B ( P <0.05), but no significant difference was found between groups C and D ( P >0.05). Loading naringin composite scaffolds have good biocompatibility and effect in repair of rabbit articular osteochondral defects.

GLobal Integrated Design Environment

NASA Technical Reports Server (NTRS)

Kunkel, Matthew; McGuire, Melissa; Smith, David A.; Gefert, Leon P.

2011-01-01

The GLobal Integrated Design Environment (GLIDE) is a collaborative engineering application built to resolve the design session issues of real-time passing of data between multiple discipline experts in a collaborative environment. Utilizing Web protocols and multiple programming languages, GLIDE allows engineers to use the applications to which they are accustomed in this case, Excel to send and receive datasets via the Internet to a database-driven Web server. Traditionally, a collaborative design session consists of one or more engineers representing each discipline meeting together in a single location. The discipline leads exchange parameters and iterate through their respective processes to converge on an acceptable dataset. In cases in which the engineers are unable to meet, their parameters are passed via e-mail, telephone, facsimile, or even postal mail. The result of this slow process of data exchange would elongate a design session to weeks or even months. While the iterative process remains in place, software can now exchange parameters securely and efficiently, while at the same time allowing for much more information about a design session to be made available. GLIDE is written in a compilation of several programming languages, including REALbasic, PHP, and Microsoft Visual Basic. GLIDE client installers are available to download for both Microsoft Windows and Macintosh systems. The GLIDE client software is compatible with Microsoft Excel 2000 or later on Windows systems, and with Microsoft Excel X or later on Macintosh systems. GLIDE follows the Client-Server paradigm, transferring encrypted and compressed data via standard Web protocols. Currently, the engineers use Excel as a front end to the GLIDE Client, as many of their custom tools run in Excel.

Preliminary Study on Kano Model in the Conceptual Design Activities for Product Lifecycle Improvement

NASA Astrophysics Data System (ADS)

Fahrul Hassan, Mohd; Rahman, M. R. A.; Arifin, A. M. T.; Ismail, A. E.; Rasidi Ibrahim, M.; Zulafif Rahim, M.; Fauzi Ahmad, Md

2017-08-01

Product manufactured with short life cycle had only one major issue, it can lead to increasing volume of waste. Day by day, this untreated waste had consumed many landfill spaces, waiting for any possible alternatives. Lack of product recovery knowledge and recyclability features imprinted into product design are one of the main reason behind all this. Sustainable awareness aspect should not just be implied into people’s mind, but also onto product design. This paper presents a preliminary study on Kano model method in the conceptual design activities to improve product lifecycle. Kano model is a survey-type method, used to analyze and distinguished product qualities or features, also how the customers may have perceived them. Three important attributes of Kano model are performance, attractive and must-be. The proposed approach enables better understanding of customer requirements while providing a way for Kano model to be integrated into engineering design to improve product’s end-of-life. Further works will be continued to provide a better lifecycle option (increase percentage of reuse, remanufacture or recycle, whereby decrease percentage of waste) of a product using Kano model approach.

Design of a Facility to Test the Advanced Stirling Radioisotope Generator Engineering Unit

NASA Technical Reports Server (NTRS)

Lewandowski, Edward J.; Schreiber, Jeffrey G.; Oriti, Salvatore M.; Meer, David W.; Brace, Michael H.; Dugala, Gina

2009-01-01

The Advanced Stirling Radioisotope Generator (ASRG) is being considered to power deep space missions. An engineering unit, the ASRG-EU, was designed and fabricated by Lockheed Martin under contract to the Department of Energy. This unit is currently on an extended operation test at NASA Glenn Research Center to generate performance data and validate the life and reliability predictions for the generator and the Stirling convertors. A special test facility was designed and built for testing the ASRG-EU. Details of the test facility design are discussed. The facility can operate the convertors under AC bus control or with the ASRG-EU controller. It can regulate input thermal power in either a fixed temperature or fixed power mode. An enclosure circulates cooled air around the ASRG-EU to remove heat rejected from the ASRG-EU by convection. A custom monitoring and data acquisition system supports the test. Various safety features, which allow 2417 unattended operation, are discussed.

BIOMedical Search Engine Framework: Lightweight and customized implementation of domain-specific biomedical search engines.

PubMed

Jácome, Alberto G; Fdez-Riverola, Florentino; Lourenço, Anália

2016-07-01

Text mining and semantic analysis approaches can be applied to the construction of biomedical domain-specific search engines and provide an attractive alternative to create personalized and enhanced search experiences. Therefore, this work introduces the new open-source BIOMedical Search Engine Framework for the fast and lightweight development of domain-specific search engines. The rationale behind this framework is to incorporate core features typically available in search engine frameworks with flexible and extensible technologies to retrieve biomedical documents, annotate meaningful domain concepts, and develop highly customized Web search interfaces. The BIOMedical Search Engine Framework integrates taggers for major biomedical concepts, such as diseases, drugs, genes, proteins, compounds and organisms, and enables the use of domain-specific controlled vocabulary. Technologies from the Typesafe Reactive Platform, the AngularJS JavaScript framework and the Bootstrap HTML/CSS framework support the customization of the domain-oriented search application. Moreover, the RESTful API of the BIOMedical Search Engine Framework allows the integration of the search engine into existing systems or a complete web interface personalization. The construction of the Smart Drug Search is described as proof-of-concept of the BIOMedical Search Engine Framework. This public search engine catalogs scientific literature about antimicrobial resistance, microbial virulence and topics alike. The keyword-based queries of the users are transformed into concepts and search results are presented and ranked accordingly. The semantic graph view portraits all the concepts found in the results, and the researcher may look into the relevance of different concepts, the strength of direct relations, and non-trivial, indirect relations. The number of occurrences of the concept shows its importance to the query, and the frequency of concept co-occurrence is indicative of biological relations meaningful to that particular scope of research. Conversely, indirect concept associations, i.e. concepts related by other intermediary concepts, can be useful to integrate information from different studies and look into non-trivial relations. The BIOMedical Search Engine Framework supports the development of domain-specific search engines. The key strengths of the framework are modularity and extensibilityin terms of software design, the use of open-source consolidated Web technologies, and the ability to integrate any number of biomedical text mining tools and information resources. Currently, the Smart Drug Search keeps over 1,186,000 documents, containing more than 11,854,000 annotations for 77,200 different concepts. The Smart Drug Search is publicly accessible at http://sing.ei.uvigo.es/sds/. The BIOMedical Search Engine Framework is freely available for non-commercial use at https://github.com/agjacome/biomsef. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

High-output LED-based light engine for profile lighting fixtures with high color uniformity using freeform reflectors.

PubMed

Gadegaard, Jesper; Jensen, Thøger Kari; Jørgensen, Dennis Thykjær; Kristensen, Peter Kjær; Søndergaard, Thomas; Pedersen, Thomas Garm; Pedersen, Kjeld

2016-02-20

In the stage lighting and entertainment market, light engines (LEs) for lighting fixtures are often based on high-intensity discharge (HID) bulbs. Switching to LED-based light engines gives possibilities for fast switching, additive color mixing, a longer lifetime, and potentially, more energy-efficient systems. The lumen output of a single LED is still not sufficient to replace an HID source in high-output profile fixtures, but combining multiple LEDs can create an LE with a similar output, but with added complexity. This paper presents the results of modeling and testing such a light engine. Custom ray-tracing software was used to design a high-output red, green and blue LED-based light engine with twelve CBT-90 LEDs using a dual-reflector principle. The simulated optical system efficiency was 0.626 with a perfect (R=1) reflector coating for light delivered on a target surface through the entire optical system. A profile lighting fixture prototype was created, and provided an output of 6744 lumen and an efficiency of 0.412. The lower efficiency was mainly due to a non-optimal reflector coating, and the optimized design is expected to reach a significantly higher efficiency.

Effect of ceramic calcium-phosphorus ratio on chondrocyte-mediated biosynthesis and mineralization.

PubMed

Boushell, Margaret K; Khanarian, Nora T; LeGeros, Raquel Z; Lu, Helen H

2017-10-01

The osteochondral interface functions as a structural barrier between cartilage and bone, maintaining tissue integrity postinjury and during homeostasis. Regeneration of this calcified cartilage region is thus essential for integrative cartilage healing, and hydrogel-ceramic composite scaffolds have been explored for calcified cartilage formation. The objective of this study is to test the hypothesis that Ca/P ratio of the ceramic phase of the composite scaffold regulates chondrocyte biosynthesis and mineralization potential. Specifically, the response of deep zone chondrocytes to two bioactive ceramics with different calcium-phosphorus ratios (1.35 ± 0.01 and 1.41 ± 0.02) was evaluated in agarose hydrogel scaffolds over two weeks in vitro. It was observed that the ceramic with higher calcium-phosphorus ratio enhanced chondrocyte proliferation, glycosaminoglycan production, and induced an early onset of alkaline phosphorus activity, while the ceramic with lower calcium-phosphorus ratio performed similarly to the ceramic-free control. These results underscore the importance of ceramic bioactivity in directing chondrocyte response, and demonstrate that Ca/P ratio is a key parameter to be considered in osteochondral scaffold design. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2694-2702, 2017. © 2017 Wiley Periodicals, Inc.

Supporting Educational Games in Higher Education: The Creation and Implementation of Custom Game Engine for a University

ERIC Educational Resources Information Center

Choi, Gi Woong; Pursel, Barton K.; Stubbs, Chris

2017-01-01

Interest towards implementing educational gaming into courses within higher education continues to increase, but it requires extensive amounts of resources to create individual games for each course. This paper is a description of a university's effort to create a custom educational game engine to streamline the game development process within the…

The ATPG Attack for Reverse Engineering of Combinational Hybrid Custom-Programmable Circuits

DTIC Science & Technology

2017-03-23

The ATPG Attack for Reverse Engineering of Combinational Hybrid Custom- Programmable Circuits Raza Shafiq Hamid Mahmoodi Houman Homayoun Hassan... programmable circuits. While functionality of programmable cells are only known to trusted parties, effective techniques for activation and propagation...of the cells are introduced. The ATPG attack carefully studies dependency of programmable cells to develop their (partial) truth tables. Results

Teaching customer-centric operations management - evidence from an experiential learning-oriented mass customisation class

NASA Astrophysics Data System (ADS)

Medini, Khaled

2018-01-01

The increase of individualised customer demands and tough competition in the manufacturing sector gave rise to more customer-centric operations management such as products and services (mass) customisation. Mass customisation (MC), which inherits the 'economy of scale' from mass production (MP), aims to meet specific customer demands with near MP efficiency. Such an overarching concept has multiple impacts on operations management. This requires highly qualified and multi-skilled engineers who are well prepared for managing MC. Therefore, this concept should be properly addressed by engineering education curricula which needs to keep up with the emerging business trends. This paper introduces a novel course about MC and variety in operations management which recalls several Experiential Learning (EL) practices consistently with the principle of an active learning. The paper aims to analyse to which extent EL can improve the efficiency of the teaching methods and the retention rate in the context of operations management. The proposed course is given to engineering students whose' perceptions are collected using semi-structured questionnaires and analysed quantitatively and qualitatively. The paper highlights the relevance (i) of teaching MC, and (ii) of active learning in engineering education, through the specific application in the domain of MC.

The method to divide a sentence of requirement into individual requirements and the development of requirement specification editor which can describe individual requirements.

PubMed

Sato, Kuniya; Ooba, Masahiro; Takagi, Tomohiko; Furukawa, Zengo; Komiya, Seiichi; Yaegashi, Rihito

2013-12-01

Agile software development gains requirements from the direct discussion with customers and the development staff each time, and the customers evaluate the appropriateness of the requirement. If the customers divide the complicated requirement into individual requirements, the engineer who is in charge of software development can understand it easily. This is called division of requirement. However, the customers do not understand how much and how to divide the requirements. This paper proposes the method to divide a complicated requirement into individual requirements. Also, it shows the development of requirement specification editor which can describe individual requirements. The engineer who is in charge of software development can understand requirements easily.

Tip-Clearance Measurement in the First Stage of the Compressor of an Aircraft Engine.

PubMed

García, Iker; Przysowa, Radosław; Amorebieta, Josu; Zubia, Joseba

2016-11-11

In this article, we report the design of a reflective intensity-modulated optical fiber sensor for blade tip-clearance measurement, and the experimental results for the first stage of a compressor of an aircraft engine operating in real conditions. The tests were performed in a ground test cell, where the engine completed four cycles from idling state to takeoff and back to idling state. During these tests, the rotational speed of the compressor ranged between 7000 and 15,600 rpm. The main component of the sensor is a tetrafurcated bundle of optical fibers, with which the resulting precision of the experimental measurements was 12 µm for a measurement range from 2 to 4 mm. To get this precision the effect of temperature on the optoelectronic components of the sensor was compensated by calibrating the sensor in a climate chamber. A custom-designed MATLAB program was employed to simulate the behavior of the sensor prior to its manufacture.

Tip-Clearance Measurement in the First Stage of the Compressor of an Aircraft Engine

PubMed Central

García, Iker; Przysowa, Radosław; Amorebieta, Josu; Zubia, Joseba

2016-01-01

In this article, we report the design of a reflective intensity-modulated optical fiber sensor for blade tip-clearance measurement, and the experimental results for the first stage of a compressor of an aircraft engine operating in real conditions. The tests were performed in a ground test cell, where the engine completed four cycles from idling state to takeoff and back to idling state. During these tests, the rotational speed of the compressor ranged between 7000 and 15,600 rpm. The main component of the sensor is a tetrafurcated bundle of optical fibers, with which the resulting precision of the experimental measurements was 12 µm for a measurement range from 2 to 4 mm. To get this precision the effect of temperature on the optoelectronic components of the sensor was compensated by calibrating the sensor in a climate chamber. A custom-designed MATLAB program was employed to simulate the behavior of the sensor prior to its manufacture. PMID:27845709

SmartSIM - a virtual reality simulator for laparoscopy training using a generic physics engine.

PubMed

Khan, Zohaib Amjad; Kamal, Nabeel; Hameed, Asad; Mahmood, Amama; Zainab, Rida; Sadia, Bushra; Mansoor, Shamyl Bin; Hasan, Osman

2017-09-01

Virtual reality (VR) training simulators have started playing a vital role in enhancing surgical skills, such as hand-eye coordination in laparoscopy, and practicing surgical scenarios that cannot be easily created using physical models. We describe a new VR simulator for basic training in laparoscopy, i.e. SmartSIM, which has been developed using a generic open-source physics engine called the simulation open framework architecture (SOFA). This paper describes the systems perspective of SmartSIM including design details of both hardware and software components, while highlighting the critical design decisions. Some of the distinguishing features of SmartSIM include: (i) an easy-to-fabricate custom-built hardware interface; (ii) use of a generic physics engine to facilitate wider accessibility of our work and flexibility in terms of using various graphical modelling algorithms and their implementations; and (iii) an intelligent and smart evaluation mechanism that facilitates unsupervised and independent learning. Copyright © 2016 John Wiley & Sons, Ltd.

Automated and comprehensive link engineering supporting branched, ring, and mesh network topologies

NASA Astrophysics Data System (ADS)

Farina, J.; Khomchenko, D.; Yevseyenko, D.; Meester, J.; Richter, A.

2016-02-01

Link design, while relatively easy in the past, can become quite cumbersome with complex channel plans and equipment configurations. The task of designing optical transport systems and selecting equipment is often performed by an applications or sales engineer using simple tools, such as custom Excel spreadsheets. Eventually, every individual has their own version of the spreadsheet as well as their own methodology for building the network. This approach becomes unmanageable very quickly and leads to mistakes, bending of the engineering rules and installations that do not perform as expected. We demonstrate a comprehensive planning environment, which offers an efficient approach to unify, control and expedite the design process by controlling libraries of equipment and engineering methodologies, automating the process and providing the analysis tools necessary to predict system performance throughout the system and for all channels. In addition to the placement of EDFAs and DCEs, performance analysis metrics are provided at every step of the way. Metrics that can be tracked include power, CD and OSNR, SPM, XPM, FWM and SBS. Automated routine steps assist in design aspects such as equalization, padding and gain setting for EDFAs, the placement of ROADMs and transceivers, and creating regeneration points. DWDM networks consisting of a large number of nodes and repeater huts, interconnected in linear, branched, mesh and ring network topologies, can be designed much faster when compared with conventional design methods. Using flexible templates for all major optical components, our technology-agnostic planning approach supports the constant advances in optical communications.

Engineering Design and Automation in the Applied Engineering Technologies (AET) Group at Los Alamos National Laboratory.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wantuck, P. J.; Hollen, R. M.

2002-01-01

This paper provides an overview of some design and automation-related projects ongoing within the Applied Engineering Technologies (AET) Group at Los Alamos National Laboratory. AET uses a diverse set of technical capabilities to develop and apply processes and technologies to applications for a variety of customers both internal and external to the Laboratory. The Advanced Recovery and Integrated Extraction System (ARIES) represents a new paradigm for the processing of nuclear material from retired weapon systems in an environment that seeks to minimize the radiation dose to workers. To achieve this goal, ARIES relies upon automation-based features to handle and processmore » the nuclear material. Our Chemical Process Development Team specializes in fuzzy logic and intelligent control systems. Neural network technology has been utilized in some advanced control systems developed by team members. Genetic algorithms and neural networks have often been applied for data analysis. Enterprise modeling, or discrete event simulation, as well as chemical process simulation has been employed for chemical process plant design. Fuel cell research and development has historically been an active effort within the AET organization. Under the principal sponsorship of the Department of Energy, the Fuel Cell Team is now focusing on technologies required to produce fuel cell compatible feed gas from reformation of a variety of conventional fuels (e.g., gasoline, natural gas), principally for automotive applications. This effort involves chemical reactor design and analysis, process modeling, catalyst analysis, as well as full scale system characterization and testing. The group's Automation and Robotics team has at its foundation many years of experience delivering automated and robotic systems for nuclear, analytical chemistry, and bioengineering applications. As an integrator of commercial systems and a developer of unique custom-made systems, the team currently supports the automation needs of many Laboratory programs.« less

The use of a cartilage decellularized matrix scaffold for the repair of osteochondral defects: the importance of long-term studies in a large animal model.

PubMed

Vindas Bolaños, R A; Cokelaere, S M; Estrada McDermott, J M; Benders, K E M; Gbureck, U; Plomp, S G M; Weinans, H; Groll, J; van Weeren, P R; Malda, J

2017-03-01

To investigate the effect of decellularized cartilage-derived matrix (CDM) scaffolds, by itself and as a composite scaffold with a calcium phosphate (CaP) base, for the repair of osteochondral defects. It was hypothesized that the chondral defects would heal with fibrocartilaginous tissue and that the composite scaffold would result in better bone formation. After an 8-week pilot experiment in a single horse, scaffolds were implanted in eight healthy horses in osteochondral defects on the medial trochlear ridge of the femur. In one joint a composite CDM-CaP scaffold was implanted (+P), in the contralateral joint a CDM only (-P) scaffold. After euthanasia at 6 months, tissues were analysed by histology, immunohistochemistry, micro-CT, biochemistry and biomechanical evaluation. The 8-week pilot showed encouraging formation of bone and cartilage, but incomplete defect filling. At 6 months, micro-CT and histology showed much more limited filling of the defect, but the CaP component of the +P scaffolds was well integrated with the surrounding bone. The repair tissue was fibrotic with high collagen type I and low type II content and with no differences between the groups. There were also no biochemical differences between the groups and repair tissue was much less stiff than normal tissue (P < 0.0001). The implants failed to produce reasonable repair tissue in this osteochondral defect model, although the CaP base in the -P group integrated well with the recipient bone. The study stresses the importance of long-term in vivo studies to assess the efficacy of cartilage repair techniques. Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

2D and 3D MOCART scoring systems assessed by 9.4 T high-field MRI correlate with elementary and complex histological scoring systems in a translational model of osteochondral repair.

PubMed

Goebel, L; Zurakowski, D; Müller, A; Pape, D; Cucchiarini, M; Madry, H

2014-10-01

To compare the 2D and 3D MOCART system obtained with 9.4 T high-field magnetic resonance imaging (MRI) for the ex vivo analysis of osteochondral repair in a translational model and to correlate the data with semiquantitative histological analysis. Osteochondral samples representing all levels of repair (sheep medial femoral condyles; n = 38) were scanned in a 9.4 T high-field MRI. The 2D and adapted 3D MOCART systems were used for grading after point allocation to each category. Each score was correlated with corresponding reconstructions between both MOCART systems. Data were next correlated with corresponding categories of an elementary (Wakitani) and a complex (Sellers) histological scoring system as gold standards. Correlations between most 2D and 3D MOCART score categories were high, while mean total point values of 3D MOCART scores tended to be 15.8-16.1 points higher compared to the 2D MOCART scores based on a Bland-Altman analysis. "Defect fill" and "total points" of both MOCART scores correlated with corresponding categories of Wakitani and Sellers scores (all P ≤ 0.05). "Subchondral bone plate" also correlated between 3D MOCART and Sellers scores (P < 0.001). Most categories of the 2D and 3D MOCART systems correlate, while total scores were generally higher using the 3D MOCART system. Structural categories "total points" and "defect fill" can reliably be assessed by 9.4 T MRI evaluation using either system, "subchondral bone plate" using the 3D MOCART score. High-field MRI is valuable to objectively evaluate osteochondral repair in translational settings. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Transplantation of Scaffold-Free Cartilage-Like Cell-Sheets Made from Human Bone Marrow Mesenchymal Stem Cells for Cartilage Repair: A Preclinical Study.

PubMed

Itokazu, Maki; Wakitani, Shigeyuki; Mera, Hisashi; Tamamura, Yoshihiro; Sato, Yasushi; Takagi, Mutsumi; Nakamura, Hiroaki

2016-10-01

The object of this study was to determine culture conditions that create stable scaffold-free cartilage-like cell-sheets from human bone marrow-derived mesenchymal stem cells (hBMSCs) and to assess their effects after transplantation into osteochondral defects in nude rats. (Experiment 1) The hBMSCs were harvested from 3 males, the proliferative and chondrogenic capacities were assessed at passage 1, and the cells were expanded in 3 different culture conditions: (1) 5% fetal bovine serum (FBS), (2) 10% FBS, and (3) 5% FBS with fibroblast growth factor 2 (FGF-2). The cells were harvested and made chondrogenic pellet culture. The cell proliferation rate, glycosaminoglycan/DNA ratio, and safranin-O staining intensity of pellets cultured condition 3 were higher than those of conditions 1 and 2. (Experiment 2) The hBMSCs were expanded and passaged 3 times under culture condition 3, and fabricate the cell-sheets in chondrogenic medium either with or without FBS. The cell-sheets fabricated with FBS maintained their size with flat edges. (Experiment 3) The cell-sheets were transplanted into osteochondral defects in nude rats. Histological analysis was performed at 2, 4, and 12 weeks after surgery. The osteochondral repair was better after sheet transplantation than in the control group and significantly improved Wakitani score. Immunostaining with human-specific vimentin antibody showed that the transplanted cells became fewer and disappeared at 12 weeks. These results indicate that culture with FGF-2 may help to quickly generate sufficient numbers of cells to create stable and reliable scaffold-free cartilage-like cell-sheets, which contribute to the regeneration of osteochondral defects.

Impact insertion of osteochondral grafts: Interference fit and central graft reduction affect biomechanics and cartilage damage.

PubMed

Su, Alvin W; Chen, Yunchan; Wailes, Dustin H; Wong, Van W; Cai, Shengqiang; Chen, Albert C; Bugbee, William D; Sah, Robert L

2018-01-01

An osteochondral graft (OCG) is an effective treatment for articular cartilage and osteochondral defects. Impact of an OCG during insertion into the osteochondral recipient site (OCR) can cause chondrocyte death and matrix damage. The aim of the present study was to analyze the effects of graft-host interference fit and a modified OCG geometry on OCG insertion biomechanics and cartilage damage. The effects of interference fit (radius of OCG - radius of OCR), loose (0.00 mm), moderate (0.05 mm), tight (0.10 mm), and of a tight fit with OCG geometry modification (central region of decreased radius), were analyzed for OCG cylinders and OCR blocks from adult bovine knee joints with an instrumented drop tower apparatus. An increasingly tight (OCG - OCR) interference fit led to increased taps for insertion, peak axial force, graft cartilage axial compression, cumulative and total energy delivery to cartilage, lower time of peak axial force, lesser graft advancement during each tap, higher total crack length in the cartilage surface, and lower chondrocyte viability. The modified OCG, with reduction of diameter in the central area, altered the biomechanical insertion variables and biological consequences to be similar to those of the moderate interference fit scenario. Micro-computed tomography confirmed structural interference between the OCR bone and both the proximal and distal bone segments of the OCGs, with the central regions being slightly separated for the modified OCGs. These results clarify OCG insertion biomechanics and mechanobiology, and introduce a simple modification of OCGs that facilitates insertion with reduced energy while maintaining a structural interference fit. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:377-386, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Rapid Modeling and Analysis Tools: Evolution, Status, Needs and Directions

NASA Technical Reports Server (NTRS)

Knight, Norman F., Jr.; Stone, Thomas J.; Ransom, Jonathan B. (Technical Monitor)

2002-01-01

Advanced aerospace systems are becoming increasingly more complex, and customers are demanding lower cost, higher performance, and high reliability. Increased demands are placed on the design engineers to collaborate and integrate design needs and objectives early in the design process to minimize risks that may occur later in the design development stage. High performance systems require better understanding of system sensitivities much earlier in the design process to meet these goals. The knowledge, skills, intuition, and experience of an individual design engineer will need to be extended significantly for the next generation of aerospace system designs. Then a collaborative effort involving the designer, rapid and reliable analysis tools and virtual experts will result in advanced aerospace systems that are safe, reliable, and efficient. This paper discusses the evolution, status, needs and directions for rapid modeling and analysis tools for structural analysis. First, the evolution of computerized design and analysis tools is briefly described. Next, the status of representative design and analysis tools is described along with a brief statement on their functionality. Then technology advancements to achieve rapid modeling and analysis are identified. Finally, potential future directions including possible prototype configurations are proposed.

Reinforcement of mono- and bi-layer poly(ethylene glycol) hydrogels with a fibrous collagen scaffold

PubMed Central

Kinneberg, K. R. C.; Nelson, A.; Stender, M.; Aziz, A. H.; Mozdzen, L. C.; Harley, B. A. C.; Bryant, S. J.; Ferguson, V. L.

2015-01-01

Biomaterial-based tissue engineering strategies hold great promise for osteochondral tissue repair. Yet significant challenges remain in joining highly dissimilar materials to achieve a biomimetic, mechanically robust design for repairing interfaces between soft tissue and bone. This study sought to improve interfacial properties and function in a bilayer, multi-phase hydrogel interpenetrated with a fibrous collagen scaffold. ‘Soft’ 10% (w/w) and ‘stiff’ 30% (w/w) PEGDM was formed into mono- or bilayer hydrogels possessing a sharp diffusional interface. Hydrogels were evaluated as single- (hydrogel only) or multi-phase (hydrogel+fibrous scaffold penetrating throughout the stiff layer and extending >500μm into the soft layer). Including a fibrous scaffold into both soft and stiff single-phase hydrogels significantly increased tangent modulus and toughness and decreased lateral expansion under compressive loading. In multi-phase hydrogels, finite element simulations predict substantially reduced stress and strain gradients across the soft—stiff hydrogel interface. When combining two low moduli constituent material, composites theory poorly predicts the observed, large modulus increases. These results suggest material structure associated with the fibrous scaffold penetrating within the PEG hydrogel as the major contributor to improved properties and function – the hydrogel bore compressive loads and the 3D fibrous scaffold was loaded in tension thus resisting lateral expansion. PMID:26001970

Engineering Lessons Learned and Systems Engineering Applications

NASA Technical Reports Server (NTRS)

Gill, Paul S.; Garcia, Danny; Vaughan, William W.

2005-01-01

Systems Engineering is fundamental to good engineering, which in turn depends on the integration and application of engineering lessons learned and technical standards. Thus, good Systems Engineering also depends on systems engineering lessons learned from within the aerospace industry being documented and applied. About ten percent of the engineering lessons learned documented in the NASA Lessons Learned Information System are directly related to Systems Engineering. A key issue associated with lessons learned datasets is the communication and incorporation of this information into engineering processes. Systems Engineering has been defined (EINIS-632) as "an interdisciplinary approach encompassing the entire technical effort to evolve and verify an integrated and life-cycle balanced set of system people, product, and process solutions that satisfy customer needs". Designing reliable space-based systems has always been a goal for NASA, and many painful lessons have been learned along the way. One of the continuing functions of a system engineer is to compile development and operations "lessons learned" documents and ensure their integration into future systems development activities. They can produce insights and information for risk identification identification and characterization. on a new project. Lessons learned files from previous projects are especially valuable in risk

19 CFR 191.142 - Procedure.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Procedure. 191.142 Section 191.142 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Foreign-Built Jet Aircraft Engines Processed in the United States § 191.142 Procedure...

19 CFR 191.142 - Procedure.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 2 2011-04-01 2011-04-01 false Procedure. 191.142 Section 191.142 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Foreign-Built Jet Aircraft Engines Processed in the United States § 191.142 Procedure...

The interplay between customer participation and difficulty of design examples in the online designing process and its effect on customer satisfaction: mediational analyses.

PubMed

Chang, Chia-Chi; Chen, Hui-Yun; Huang, I-Chiang

2009-04-01

In the current consumer-centric economy, consumers increasingly desire the opportunity to design their own products in order to express more effectively their self-image. Mass customization, based on efficient and flexible modulization designs, has provided individualized products to satisfy this desire. This work presents an experiment employed to demonstrate that customer participation leads to higher satisfaction. Specifically, the increment in customer satisfaction due to participation is greater when an easy example is provided than when either no example or a difficult one is provided. Additionally, self-congruity plays a mediating role on the customer participation-satisfaction relationship, and this mediating effect varies across different levels of the design example provided in the design process. When an easy design example is present, customer participation has a direct effect on satisfaction, in addition to the indirect effect of self-congruity. When a difficult example is provided, customer participation does not have incremental effects on either self-congruity or customer satisfaction. Finally, when no design example is shown to customers, contrary to our expectation, participation still enhances customer satisfaction due to an increased sense of self-congruity.

Purpose-driven biomaterials research in liver-tissue engineering.

PubMed

Ananthanarayanan, Abhishek; Narmada, Balakrishnan Chakrapani; Mo, Xuejun; McMillian, Michael; Yu, Hanry

2011-03-01

Bottom-up engineering of microscale tissue ("microtissue") constructs to recapitulate partially the complex structure-function relationships of liver parenchyma has been realized through the development of sophisticated biomaterial scaffolds, liver-cell sources, and in vitro culture techniques. With regard to in vivo applications, the long-lived stem/progenitor cell constructs can improve cell engraftment, whereas the short-lived, but highly functional hepatocyte constructs stimulate host liver regeneration. With regard to in vitro applications, microtissue constructs are being adapted or custom-engineered into cell-based assays for testing acute, chronic and idiosyncratic toxicities of drugs or pathogens. Systems-level methods and computational models that represent quantitative relationships between biomaterial scaffolds, cells and microtissue constructs will further enable their rational design for optimal integration into specific biomedical applications. Copyright © 2010 Elsevier Ltd. All rights reserved.

NASA's Optical Program on Ascension Island: Bringing MCAT to Life as the Eugene Stansbery-Meter Class Autonomous Telescope (ES-MCAT)

NASA Astrophysics Data System (ADS)

Lederer, S. M.; Hickson, P.; Cowardin, H. M.; Buckalew, B.; Frith, J.; Alliss, R.

In June 2015, the construction of the Meter Class Autonomous Telescope was completed and MCAT saw the light of the stars for the first time. In 2017, MCAT was newly dedicated as the Eugene Stansbery-MCAT telescope by NASA’s Orbital Debris Program Office (ODPO), in honour of his inspiration and dedication to this newest optical member of the NASA ODPO. Since that time, MCAT has viewed the skies with one engineering camera and two scientific cameras, and the ODPO optical team has begun the process of vetting the entire system. The full system vetting includes verification and validation of: (1) the hardware comprising the system (e.g. the telescopes and its instruments, the dome, weather systems, all-sky camera, FLIR cloud infrared camera, etc.), (2) the custom-written Observatory Control System (OCS) master software designed to autonomously control this complex system of instruments, each with its own control software, and (3) the custom written Orbital Debris Processing software for post-processing the data. ES-MCAT is now capable of autonomous observing to include Geosyncronous survey, TLE (Two-line element) tracking of individual catalogued debris at all orbital regimes (Low-Earth Orbit all the way to Geosynchronous (GEO) orbit), tracking at specified non-sidereal rates, as well as sidereal rates for proper calibration with standard stars. Ultimately, the data will be used for validation of NASA’s Orbital Debris Engineering Model, ORDEM, which aids in engineering designs of spacecraft that require knowledge of the orbital debris environment and long-term risks for collisions with Resident Space Objects (RSOs).

NASA's Optical Program on Ascension Island: Bringing MCAT to Life as the Eugene Stansbery-Meter Class Autonomous Telescope (ES-MCAT)

NASA Technical Reports Server (NTRS)

Lederer, S. M.; Hickson, P.; Cowardin, H. M.; Buckalew, B.; Frith, J.; Alliss, R.

2017-01-01

In June 2015, the construction of the Meter Class Autonomous Telescope was completed and MCAT saw the light of the stars for the first time. In 2017, MCAT was newly dedicated as the Eugene Stansbery-MCAT telescope by NASA's Orbital Debris Program Office (ODPO), in honor of his inspiration and dedication to this newest optical member of the NASA ODPO. Since that time, MCAT has viewed the skies with one engineering camera and two scientific cameras, and the ODPO optical team has begun the process of vetting the entire system. The full system vetting includes verification and validation of: (1) the hardware comprising the system (e.g. the telescopes and its instruments, the dome, weather systems, all-sky camera, FLIR cloud infrared camera, etc.), (2) the custom-written Observatory Control System (OCS) master software designed to autonomously control this complex system of instruments, each with its own control software, and (3) the custom written Orbital Debris Processing software for post-processing the data. ES-MCAT is now capable of autonomous observing to include Geosynchronous survey, TLE (Two-line element) tracking of individual catalogued debris at all orbital regimes (Low-Earth Orbit all the way to Geosynchronous (GEO) orbit), tracking at specified non-sidereal rates, as well as sidereal rates for proper calibration with standard stars. Ultimately, the data will be used for validation of NASA's Orbital Debris Engineering Model, ORDEM, which aids in engineering designs of spacecraft that require knowledge of the orbital debris environment and long-term risks for collisions with Resident Space Objects (RSOs).

ANSYS UIDL-Based CAE Development of Axial Support System for Optical Mirror

NASA Astrophysics Data System (ADS)

Yang, De-Hua; Shao, Liang

2008-09-01

The Whiffle-tree type axial support mechanism is widely adopted by most relatively large optical mirrors. Based on the secondary developing tools offered by the commonly used Finite Element Anylysis (FEA) software ANSYS, ANSYS Parametric Design Language (APDL) is used for creating the mirror FEA model driven by parameters, and ANSYS User Interface Design Language (UIDL) for generating custom menu of interactive manner, whereby, the relatively independent dedicated Computer Aided Engineering (CAE) module is embedded in ANSYS for calculation and optimization of axial Whiffle-tree support of optical mirrors. An example is also described to illustrate the intuitive and effective usage of the dedicated module by boosting work efficiency and releasing related engineering knowledge of user. The philosophy of secondary-developed special module with commonly used software also suggests itself for product development in other industries.

Streamlining the Design-to-Build Transition with Build-Optimization Software Tools.

PubMed

Oberortner, Ernst; Cheng, Jan-Fang; Hillson, Nathan J; Deutsch, Samuel

2017-03-17

Scaling-up capabilities for the design, build, and test of synthetic biology constructs holds great promise for the development of new applications in fuels, chemical production, or cellular-behavior engineering. Construct design is an essential component in this process; however, not every designed DNA sequence can be readily manufactured, even using state-of-the-art DNA synthesis methods. Current biological computer-aided design and manufacture tools (bioCAD/CAM) do not adequately consider the limitations of DNA synthesis technologies when generating their outputs. Designed sequences that violate DNA synthesis constraints may require substantial sequence redesign or lead to price-premiums and temporal delays, which adversely impact the efficiency of the DNA manufacturing process. We have developed a suite of build-optimization software tools (BOOST) to streamline the design-build transition in synthetic biology engineering workflows. BOOST incorporates knowledge of DNA synthesis success determinants into the design process to output ready-to-build sequences, preempting the need for sequence redesign. The BOOST web application is available at https://boost.jgi.doe.gov and its Application Program Interfaces (API) enable integration into automated, customized DNA design processes. The herein presented results highlight the effectiveness of BOOST in reducing DNA synthesis costs and timelines.

Application of Extrusion-Based Hydrogel Bioprinting for Cartilage Tissue Engineering

PubMed Central

You, Fu; Eames, B. Frank; Chen, Xiongbiao

2017-01-01

Extrusion-based bioprinting (EBB) is a rapidly developing technique that has made substantial progress in the fabrication of constructs for cartilage tissue engineering (CTE) over the past decade. With this technique, cell-laden hydrogels or bio-inks have been extruded onto printing stages, layer-by-layer, to form three-dimensional (3D) constructs with varying sizes, shapes, and resolutions. This paper reviews the cell sources and hydrogels that can be used for bio-ink formulations in CTE application. Additionally, this paper discusses the important properties of bio-inks to be applied in the EBB technique, including biocompatibility, printability, as well as mechanical properties. The printability of a bio-ink is associated with the formation of first layer, ink rheological properties, and crosslinking mechanisms. Further, this paper discusses two bioprinting approaches to build up cartilage constructs, i.e., self-supporting hydrogel bioprinting and hybrid bioprinting, along with their applications in fabricating chondral, osteochondral, and zonally organized cartilage regenerative constructs. Lastly, current limitations and future opportunities of EBB in printing cartilage regenerative constructs are reviewed. PMID:28737701

Tailoring Enterprise Systems Engineering Policy for Project Scale and Complexity

NASA Technical Reports Server (NTRS)

Cox, Renee I.; Thomas, L. Dale

2014-01-01

Space systems are characterized by varying degrees of scale and complexity. Accordingly, cost-effective implementation of systems engineering also varies depending on scale and complexity. Recognizing that systems engineering and integration happen everywhere and at all levels of a given system and that the life cycle is an integrated process necessary to mature a design, the National Aeronautic and Space Administration's (NASA's) Marshall Space Flight Center (MSFC) has developed a suite of customized implementation approaches based on project scale and complexity. While it may be argued that a top-level system engineering process is common to and indeed desirable across an enterprise for all space systems, implementation of that top-level process and the associated products developed as a result differ from system to system. The implementation approaches used for developing a scientific instrument necessarily differ from those used for a space station. .

Software Design Improvements. Part 2; Software Quality and the Design and Inspection Process

NASA Technical Reports Server (NTRS)

Lalli, Vincent R.; Packard, Michael H.; Ziemianski, Tom

1997-01-01

The application of assurance engineering techniques improves the duration of failure-free performance of software. The totality of features and characteristics of a software product are what determine its ability to satisfy customer needs. Software in safety-critical systems is very important to NASA. We follow the System Safety Working Groups definition for system safety software as: 'The optimization of system safety in the design, development, use and maintenance of software and its integration with safety-critical systems in an operational environment. 'If it is not safe, say so' has become our motto. This paper goes over methods that have been used by NASA to make software design improvements by focusing on software quality and the design and inspection process.

Mechanical evaluation of nHAp scaffold coated with poly-3-hydroxybutyrate for bone tissue engineering.

PubMed

Foroughi, Mohammad Reza; Karbasi, Saeed; Ebrahimi-Kahrizsangi, Reza

2013-02-01

Regeneration of bone, cartilage and osteochondral tissues by tissue engineering has attracted intense attention due to its potential advantages over the traditional replacement of tissues with synthetic implants. Nevertheless, there is still a dearth of ideal or suitable scaffolds based on porous biomaterials, and the present study was undertaken to develop and evaluate a useful porous composite scaffold system. In this study, nano hydroxyapatite (nHAp) powder made (about 35-45 nm) by heating at temperature of 900 degrees C and porous hydroxyapatite (40, 50 and 60 wt% solution) for making scaffold, by using Polyurethane sponge replication method. In order to increase the scaffolds mechanical properties, they coated with 2, 4 and 6 wt% Poly-3-hydroxybutyrate (P3HB) for 30 sec and 60 sec, respectively; after the scaffold coated by Polymer and survey results, this scaffold is nHAp/P3HB composite. Based on these results, this scaffold is an optimized one among three tested above mentioned composition and can be utilized in bone tissue engineering. In the result, the best of scaffold is with 50 wt% HAp and 6 wt% P3HB and porosity of present is between 80-90% with compressive strength and modulus 1.51 MPa and 22.73 MPa, respectively, that it can be application in bone tissue engineering.

Curating the Web: Building a Google Custom Search Engine for the Arts

ERIC Educational Resources Information Center

Hennesy, Cody; Bowman, John

2008-01-01

Google's first foray onto the web made search simple and results relevant. With its Co-op platform, Google has taken another step toward dramatically increasing the relevancy of search results, further adapting the World Wide Web to local needs. Google Custom Search Engine, a tool on the Co-op platform, puts one in control of his or her own search…

19 CFR 191.144 - Refund of duties.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Refund of duties. 191.144 Section 191.144 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Foreign-Built Jet Aircraft Engines Processed in the United States § 191.144 Refund of...

19 CFR 191.144 - Refund of duties.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 2 2011-04-01 2011-04-01 false Refund of duties. 191.144 Section 191.144 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Foreign-Built Jet Aircraft Engines Processed in the United States § 191.144 Refund of...

Bone Marrow Aspirate Concentrate-Enhanced Marrow Stimulation of Chondral Defects

PubMed Central

Eichler, Hermann; Orth, Patrick

2017-01-01

Mesenchymal stem cells (MSCs) from bone marrow play a critical role in osteochondral repair. A bone marrow clot forms within the cartilage defect either as a result of marrow stimulation or during the course of the spontaneous repair of osteochondral defects. Mobilized pluripotent MSCs from the subchondral bone migrate into the defect filled with the clot, differentiate into chondrocytes and osteoblasts, and form a repair tissue over time. The additional application of a bone marrow aspirate (BMA) to the procedure of marrow stimulation is thought to enhance cartilage repair as it may provide both an additional cell population capable of chondrogenesis and a source of growth factors stimulating cartilage repair. Moreover, the BMA clot provides a three-dimensional environment, possibly further supporting chondrogenesis and protecting the subchondral bone from structural alterations. The purpose of this review is to bridge the gap in our understanding between the basic science knowledge on MSCs and BMA and the clinical and technical aspects of marrow stimulation-based cartilage repair by examining available data on the role and mechanisms of MSCs and BMA in osteochondral repair. Implications of findings from both translational and clinical studies using BMA concentrate-enhanced marrow stimulation are discussed. PMID:28607559

Hyaline cartilage surface study with an environmental scanning electron microscope. An experimental study.

PubMed

Sastre, S; Suso, S; Segur, J M; Bori, G; Carbonell, J A; Agustí, E; Nuñez, M

2009-11-01

To obtain images of the articular surface of fresh osteochondral grafts using an environmental scanning electron microscope (ESEM). To evaluate and compare the main morphological aspects of the chondral surface of the fresh grafts. To develop a validated classification system on the basis of the images obtained via the ESEM. The study was based on osteochondral fragments from the internal condyle of the knee joint of New Zealand rabbits, corresponding to fresh chondral surface. One hundred images were obtained via the ESEM and these were classified by two observers according to a category system. The Kappa index and the corresponding confidence interval (CI) were calculated. Of the samples analysed, 62-72% had an even surface. Among the samples with an uneven surface 17-22% had a hillocky appearance and 12-16% a knobbly appearance. As regards splits, these were not observed in 92-95% of the surfaces; 4-7% showed superficial splits and only 1% deep splits. In 78-82% of cases no lacunae in the surface were observed, while 17-20% showed filled lacunae and only 1-2% presented empty lacunae. The study demonstrates that the ESEM is useful for obtaining and classifying images of osteochondral grafts.

Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marriott, Craig; Gonzalez, Manual; Russell, Durrett

2011-06-30

This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc.more » in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables such as internal dilution level and charge temperature. As a result, HCCI combustion has limited robustness when variables exceed the required narrow ranges determined in this program. HCCI combustion is also not available for the entire range of production engine speeds and loads, (i.e., the dynamic range is limited). Thus, regular SI combustion must be employed for a majority of the full dynamic range of the engine. This degrades the potential fuel economy impact of HCCI combustion. Currently-available combustion control actuators for the simple valve train system engine do not have the authority for continuous air - fuel or torque control for managing the combustion mode transitions between SI and HCCI and thus, require further refinement to meet customer refinement expectations. HCCI combustion control sensors require further development to enable robust long-term HCCI combustion control. Finally, the added technologies required to effectively manage HCCI combustion such as electric cam phasers, central direct fuel injection, cylinder pressure sensing, high-flow exhaust gas recirculation system, etc. add excessive on-engine cost and complexity that erodes the production-viability business« less

Turkey BILSAT-1: a Case Study for the Surrey Know-How Transfer and Training Program

NASA Astrophysics Data System (ADS)

Ghafoor, Nadeem; Murat Leloglu, Ugur; Sweeting, Martin, , Sir

2002-01-01

Surrey has established itself over the past 18 years as a world leader in providing hands-on spacecraft engineering training through its Small Satellite Engineering Know-How Transfer and Training (`KHTT') programme. This 18- month course runs alongside the construction of a microsatellite executed through SSTL, and strikes a balance between classroom-based teaching and total immersion within professional engineering teams. Hands-on training is provided covering the entire satellite engineering process, from mission and subsystem design, through module manufacture, assembly and integration, to qualification and flight model environmental tests, launch and commissioning. SSTL's experience in providing the KHTT programme has resulted in a well-defined course structure that yet retains the ability to accommodate individual customer requirements. The programme also takes full advantage of SSTL's intrinsic link with the Surrey Space Centre (`SSC') at the University of Surrey, offering a range of MSc and PhD research programmes pursuing common research interests of both SSTL and the customer, and in many cases complementing the development of either the customer's satellite or their future plans for an evolved space capability. Throughout 2002, three KHTT programmes have run in parallel at SSTL. A team of 11 engineers from the Centre Nationale des Techniques Spatiales in Algeria have now reached completion of their programme with Alsat-1, the first enhanced microsatellite of the Disaster Monitoring Constellation (`DMC'). In December 2001, 15 engineers from the Federal Ministry of Science and Technology in Nigeria arrived at SSTL and are now midway through their programme with Nigeriasat-1, the second enhanced microsatellite of the DMC. Thirdly, arriving slightly earlier in August 2001, a team from Tubitak-Bilten in Turkey commenced their KHTT programme with BILSAT-1, a high-capability enhanced microsatellite also contributing to the DMC, and are due to continue through February 2003. This paper explores the case of BILSAT-1 as a particular example of the SSTL KHTT approach. The BILSAT-1 KHTT team comprises a core group of 8 young engineers with strong backgrounds in mechanical, electrical and electronic engineering. Complementing the activities of this SSTL-based team are 4 MSc students conducting research at the Surrey Space Centre and a number of academic staff and technicians at Tubitak-Bilten in Ankara. The core team engineers, upon completing their academic lecture programme, immediately became involved in the development work on BILSAT-1. Hardware experience has been gained through the building, integrating and testing of an engineering model, before the team proceeds with testing of the assembled BILSAT-1 flight model. The team has also worked with their colleagues at Tubitak-Bilten in proposing and designing two of the BILSAT-1 payloads, the multispectral imager and the high-performance DSP card, both being manufactured in Turkey. In support of the new facility being built at Tubitak-Bilten several future cleanroom and ECAD staff visited SSTL earlier this year to attend soldering and PCB manufacturing courses. With training in project management forming the final component of the KHTT team's training a firm basis is established from which Tubitak-Bilten hopes to further develop its own satellite production capabilities.

Around Marshall

NASA Image and Video Library

2004-02-01

Andy Jenkins, an engineer for the Lab on a Chip Applications Development program, helped build the Applications Development Unit (ADU-25), a one-of-a-kind facility for controlling and analyzing processes on chips with extreme accuracy. Pressure is used to cause fluids to travel through network of fluid pathways, or micro-channels, embossed on the chips through a process similar to the one used to print circuits on computer chips. To make customized chips for various applications, NASA has an agreement with the U.S. Army's Micro devices and Micro fabrication Laboratory at Redstone Arsenal in Huntsville, Alabama, where NASA's Marshall Space Flight Center (MSFC) is located. The Marshall Center team is also collaborating with scientists at other NASA centers and at universities to develop custom chip designs for many applications, such as studying how fluidic systems work in spacecraft and identifying microbes in self-contained life support systems. Chips could even be designed for use on Earth, such as for detecting deadly microbes in heating and air systems. (NASA/MSFC/D.Stoffer)

The Qualitative Measurement towards Emotional Feeling of Design for Product Development

NASA Astrophysics Data System (ADS)

Syaifoelida, Fevi; Megat Hamdan, M. A. M.; Murrad, M.; Aminuddin, Hazim

2018-04-01

To compete in today’s ever-growing technology market, a product needs to be well presentable to the customers. It is a challenge to design a product that is able to attract customer’s attention and to build their loyalty towards the product. A product needs to be designed with focus to give the maximum level of satisfaction to the end user which is the customer. That is the focus of this paper, to achieve customer’s satisfaction, by studying feelings and emotional value related to product designs using Kansei Engineering (KE) and to test how important that product element (level of satisfaction) by using Kano Method (KM). KE is a method of translating human emotions and feelings into product development. The method studies the human interaction and responses when a customer sees a product, then translates it into a new improved design. However, KE cannot stand on its own. It did not specify in which extends the feeling or emotions is important in a product. After we had the design appearance parameters from KE and existing design evaluation, it need to be classified which is more important than the other is. That is why Kano Method (KM) will also be used. Since this scope of study towards an emotional feeling of design (existing part/appearance) in Kano categories not in deep function of technical requirement, so KM will help to classify parts of product into categories, which part will give fully satisfaction while using it. It studies the more important attributes considered by the customers for improvement. The objective is to find out the design priority guide that can be used to maximize customer’s satisfaction. Therefore, in order to apply the qualitative measurement idea into the real situation, the headphone product is chosen (popular among students) as the product (the appearance of part, feeling when use it) domain for this study. As the results progressed, it was found out that the headband part of headphone is the most important part of the product. It needs to be durable and comfortably designed to give full satisfaction while using (Kano-functional). The research and development (R&D), and designing process of a product can be improved greatly to increase the customer’s satisfaction by capturing their emotional feeling in physiological design.

Engineering customized TALE nucleases (TALENs) and TALE transcription factors by fast ligation-based automatable solid-phase high-throughput (FLASH) assembly.

PubMed

Reyon, Deepak; Maeder, Morgan L; Khayter, Cyd; Tsai, Shengdar Q; Foley, Jonathan E; Sander, Jeffry D; Joung, J Keith

2013-07-01

Customized DNA-binding domains made using transcription activator-like effector (TALE) repeats are rapidly growing in importance as widely applicable research tools. TALE nucleases (TALENs), composed of an engineered array of TALE repeats fused to the FokI nuclease domain, have been used successfully for directed genome editing in various organisms and cell types. TALE transcription factors (TALE-TFs), consisting of engineered TALE repeat arrays linked to a transcriptional regulatory domain, have been used to up- or downregulate expression of endogenous genes in human cells and plants. This unit describes a detailed protocol for the recently described fast ligation-based automatable solid-phase high-throughput (FLASH) assembly method. FLASH enables automated high-throughput construction of engineered TALE repeats using an automated liquid handling robot or manually using a multichannel pipet. Using the automated approach, a single researcher can construct up to 96 DNA fragments encoding TALE repeat arrays of various lengths in a single day, and then clone these to construct sequence-verified TALEN or TALE-TF expression plasmids in a week or less. Plasmids required for FLASH are available by request from the Joung lab (http://eGenome.org). This unit also describes improvements to the Zinc Finger and TALE Targeter (ZiFiT Targeter) web server (http://ZiFiT.partners.org) that facilitate the design and construction of FLASH TALE repeat arrays in high throughput. © 2013 by John Wiley & Sons, Inc.

Engineering Customized TALE Nucleases (TALENs) and TALE Transcription Factors by Fast Ligation-based Automatable Solid-phase High-throughput (FLASH) Assembly

PubMed Central

Reyon, Deepak; Maeder, Morgan L.; Khayter, Cyd; Tsai, Shengdar Q.; Foley, Jonathan E.; Sander, Jeffry D.; Joung, J. Keith

2013-01-01

Customized DNA-binding domains made using Transcription Activator-Like Effector (TALE) repeats are rapidly growing in importance as widely applicable research tools. TALE nucleases (TALENs), composed of an engineered array of TALE repeats fused to the FokI nuclease domain, have been used successfully for directed genome editing in multiple different organisms and cell types. TALE transcription factors (TALE-TFs), consisting of engineered TALE repeat arrays linked to a transcriptional regulatory domain, have been used to up- or down-regulate expression of endogenous genes in human cells and plants. Here we describe a detailed protocol for practicing the recently described Fast Ligation-based Automatable Solid-phase High-throughput (FLASH) assembly method. FLASH enables automated high-throughput construction of engineered TALE repeats using an automated liquid handling robot or manually using a multi-channel pipet. With the automated version of FLASH, a single researcher can construct up to 96 DNA fragments encoding various length TALE repeat arrays in one day and then clone these to construct sequence-verified TALEN or TALE-TF expression plasmids in one week or less. Plas-mids required to practice FLASH are available by request from the Joung Lab (http://www.jounglab.org/). We also describe here improvements to the Zinc Finger and TALE Targeter (ZiFiT Targeter) webserver (http://ZiFiTBeta.partners.org) that facilitate the design and construction of FLASH TALE repeat arrays in high-throughput. PMID:23821439

Chemical Library Screening for Potential Therapeutics Using Novel Cell Based Models of ALS

DTIC Science & Technology

2017-06-01

Major Task 1, Subtask 1. Our first major activity in year 1 was the design and engineering of a custom inducible plasmid for expressing fluorescently...back to that construct. Other achievements during this first major activity derived from investigating why Broccoli RNA aptamer did not fold...These are outlined below in the CHANGES/PROBLEMS section. Major Task 1, Subtask 2. Our second major activity in year 1 was to generate human neural

Generation of Custom DSP Transform IP Cores: Case Study Walsh-Hadamard Transform

DTIC Science & Technology

2002-09-01

mathematics and hardware design What I know: Finite state machine Pipelining Systolic array … What I know: Linear algebra Digital signal processing...state machine Pipelining Systolic array … What I know: Linear algebra Digital signal processing Adaptive filter theory … A math guy A hardware engineer...Synthesis Technology Libary Bit-width (8) HF factor (1,2,3,6) VF factor (1,2,4, ... 32) Xilinx FPGA Place&Route Xilinx FPGA Place&Route Performance

Magnetic Gearboxes for Aerospace Applications

NASA Technical Reports Server (NTRS)

Perez-Diaz, Jose Luis; Diez-Jimenez, Efren; Alvarez-Valenzuela, Marco A.; Sanchez-Garcia-Casarrubios, Juan; Cristache, Christian; Valiente-Blanco, Ignacio

2014-01-01

Magnetic gearboxes are contactless mechanisms for torque-speed conversion. They present no wear, no friction and no fatigue. They need no lubricant and can be customized for other mechanical properties as stiffness or damping. Additionally, they can protect structures and mechanisms against overloads, limitting the transmitted torque. In this work, spur, planetary and "magdrive" or "harmonic drive" configurations are compared considering their use in aerospace applications. The most recent test data are summarized to provide some useful help for the design engineer.

Systems Engineering Technical Leadership Development Program

DTIC Science & Technology

2012-02-01

leading others in creative problem solving, complexity, and why projects fail . These topics were additionally supported by case studies designed to...Your Core Values Dominick Wed 12:30-1:30 Lunch Wed 1:30-2:45 Case Study: Why Projects Fail Pennotti Wed 2:45-3:00 Break Wed 3:00-4:30 Project...Case Study: When Good Wasn’t Good Enough 11. Technical Value-5: Group Project: AR2D2 RFP 12. Customer Expectation-1: Lecture: Why Systems Fail

Engineering and Design: Control Stations and Control Systems for Navigation Locks and Dams

DTIC Science & Technology

1997-05-30

of human intelli- hypothetical lock and dam configurations. Finally, b. Terminology. (1) PLC system. The computer- based systems utilize special...electrical industry for industrial use. There- fore, for purposes of this document, a computer- based system is referred to as a PLC system. (2) Relay- based ...be custom made, because most of today’s control systems of any complexity are PLC - based , the standard size of a given motor starter cubicle is not

Vision & Needs for Distributed Controls: Customers for Control Systems and What Do They Value (Postprint)

DTIC Science & Technology

2009-08-01

in engine technology 7 VS. • Military demand is growing for FADEC & control systems with expert system embedded in the S/W for fault tolerance...leverage commercial FADECs & control systems S/W & H/W. •Modular / Universal/Distributed design can reduce development time and cost. S/W could offer...baseline for military-qualified FADECs . •To promote dual use, the services must recognize the similarities between commercial applications & military

Improved quality of cartilage repair by bone marrow mesenchymal stem cells for treatment of an osteochondral defect in a cynomolgus macaque model

PubMed Central

Araki, Susumu; Imai, Shinji; Ishigaki, Hirohito; Mimura, Tomohiro; Nishizawa, Kazuya; Ueba, Hiroaki; Kumagai, Kousuke; Kubo, Mitsuhiko; Mori, Kanji; Ogasawara, Kazumasa; Matsusue, Yoshitaka

2015-01-01

Background and purpose Integration of repaired cartilage with surrounding native cartilage is a major challenge for successful tissue-engineering strategies of cartilage repair. We investigated whether incorporation of mesenchymal stem cells (MSCs) into the collagen scaffold improves integration and repair of cartilage defects in a cynomolgus macaque model. Methods Cynomolgus macaque bone marrow-derived MSCs were isolated and incorporated into type-I collagen gel. Full-thickness osteochondral defects (3 mm in diameter, 5 mm in depth) were created in the patellar groove of 36 knees of 18 macaques and were either left untreated (null group, n = 12), had collagen gel alone inserted (gel group, n = 12), or had collagen gel incorporating MSCs inserted (MSC group, n = 12). After 6, 12, and 24 weeks, the cartilage integration and tissue response were evaluated macroscopically and histologically (4 null, 4 gel, and 4 MSC knees at each time point). Results The gel group showed most cartilage-rich reparative tissue covering the defect, owing to formation of excessive cartilage extruding though the insufficient subchondral bone. Despite the fact that a lower amount of new cartilage was produced, the MSC group had better-quality cartilage with regular surface, seamless integration with neighboring naïve cartilage, and reconstruction of trabecular subchondral bone. Interpretation Even with intensive investigation, MSC-based cell therapy has not yet been established in experimental cartilage repair. Our model using cynomolgus macaques had optimized conditions, and the method using MSCs is superior to other experimental settings, allowing the possibility that the procedure might be introduced to future clinical practice. PMID:25175660

Hyaline Articular Matrix Formed by Dynamic Self-Regenerating Cartilage and Hydrogels.

PubMed

Meppelink, Amanda M; Zhao, Xing; Griffin, Darvin J; Erali, Richard; Gill, Thomas J; Bonassar, Lawrence J; Redmond, Robert W; Randolph, Mark A

2016-07-01

Injuries to the articular cartilage surface are challenging to repair because cartilage possesses a limited capacity for self-repair. The outcomes of current clinical procedures aimed to address these injuries are inconsistent and unsatisfactory. We have developed a novel method for generating hyaline articular cartilage to improve the outcome of joint surface repair. A suspension of 10(7) swine chondrocytes was cultured under reciprocating motion for 14 days. The resulting dynamic self-regenerating cartilage (dSRC) was placed in a cartilage ring and capped with fibrin and collagen gel. A control group consisted of chondrocytes encapsulated in fibrin gel. Constructs were implanted subcutaneously in nude mice and harvested after 6 weeks. Gross, histological, immunohistochemical, biochemical, and biomechanical analyses were performed. In swine patellar groove, dSRC was implanted into osteochondral defects capped with collagen gel and compared to defects filled with osteochondral plugs, collagen gel, or left empty after 6 weeks. In mice, the fibrin- and collagen-capped dSRC constructs showed enhanced contiguous cartilage matrix formation over the control of cells encapsulated in fibrin gel. Biochemically, the fibrin and collagen gel dSRC groups were statistically improved in glycosaminoglycan and hydroxyproline content compared to the control. There was no statistical difference in the biomechanical data between the dSRC groups and the control. The swine model also showed contiguous cartilage matrix in the dSRC group but not in the collagen gel and empty defects. These data demonstrate the survivability and successful matrix formation of dSRC under the mechanical forces experienced by normal hyaline cartilage in the knee joint. The results from this study demonstrate that dSRC capped with hydrogels successfully engineers contiguous articular cartilage matrix in both nonload-bearing and load-bearing environments.

Modulation of chondrogenic differentiation of human mesenchymal stem cells in jellyfish collagen scaffolds by cell density and culture medium.

PubMed

Pustlauk, W; Paul, B; Brueggemeier, S; Gelinsky, M; Bernhardt, A

2017-06-01

Studies on tissue-engineering approaches for the regeneration of traumatized cartilage focus increasingly on multipotent human mesenchymal stem cells (hMSCs) as an alternative to autologous chondrocytes. The present study applied porous scaffolds made of collagen from the jellyfish Rhopilema esculentum for the in vitro chondrogenic differentiation of hMSCs. Culture conditions in those scaffolds differ from conditions in high-density pellet cultures, making a re-examination of these data necessary. We systematically investigated the influence of seeding density, basic culture media [Dulbecco's modified Eagle's medium (DMEM), α-minimum essential medium (α-MEM)] with varying glucose content and supplementation with fetal calf serum (FCS) or bovine serum albumin (BSA) on the chondrogenic differentiation of hMSCs. Gene expression analyses of selected markers for chondrogenic differentiation and hypertrophic development were conducted. Furthermore, the production of cartilage extracellular matrix (ECM) was analysed by quantification of sulphated glycosaminoglycan and collagen type II contents. The strongest upregulation of chondrogenic markers, along with the highest ECM deposition was observed in scaffolds seeded with 2.4 × 10 6 cells/cm 3 after cultivation in high-glucose DMEM and 0.125% BSA. Lower seeding densities compared to high-density pellet cultures were sufficient to induce in vitro chondrogenic differentiation of hMSCs in collagen scaffolds, which reduces the amount of cells required for the seeding of scaffolds and thus the monolayer expansion period. Furthermore, examination of the impact of FCS and α-MEM on chondrogenic MSC differentiation is an important prerequisite for the development of an osteochondral medium for simultaneous osteogenic and chondrogenic differentiation in biphasic scaffolds for osteochondral tissue regeneration. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Re-engineering pre-employment check-up systems: a model for improving health services.

PubMed

Rateb, Said Abdel Hakim; El Nouman, Azza Abdel Razek; Rateb, Moshira Abdel Hakim; Asar, Mohamed Naguib; El Amin, Ayman Mohammed; Gad, Saad abdel Aziz; Mohamed, Mohamed Salah Eldin

2011-01-01

The purpose of this paper is to develop a model for improving health services provided by the pre-employment medical fitness check-up system affiliated to Egypt's Health Insurance Organization (HIO). Operations research, notably system re-engineering, is used in six randomly selected centers and findings before and after re-engineering are compared. The re-engineering model follows a systems approach, focusing on three areas: structure, process and outcome. The model is based on six main components: electronic booking, standardized check-up processes, protected medical documents, advanced archiving through an electronic content management (ECM) system, infrastructure development, and capacity building. The model originates mainly from customer needs and expectations. The centers' monthly customer flow increased significantly after re-engineering. The mean time spent per customer cycle improved after re-engineering--18.3 +/- 5.5 minutes as compared to 48.8 +/- 14.5 minutes before. Appointment delay was also significantly decreased from an average 18 to 6.2 days. Both beneficiaries and service providers were significantly more satisfied with the services after re-engineering. The model proves that re-engineering program costs are exceeded by increased revenue. Re-engineering in this study involved multiple structure and process elements. The literature review did not reveal similar re-engineering healthcare packages. Therefore, each element was compared separately. This model is highly recommended for improving service effectiveness and efficiency. This research is the first in Egypt to apply the re-engineering approach to public health systems. Developing user-friendly models for service improvement is an added value.

Successful marriage: American Panel Corporation and LG Philips LCD custom-designed avionic, shipboard, and rugged ground vehicle display modules from a consumer-oriented fabrication facility

NASA Astrophysics Data System (ADS)

Dunn, William; Garrett, Kimberly S.

2001-09-01

American panel corporation (APC) believes the use of custom designed (instead of ruggedized commercial) AMLCD cells is the only way to meet the specific environmental and performance requirements of the military/commercial avionic, shipboard and rugged ground vehicle markets. The APC/LG.Philips LCD (LG) custom approach mitigates risk to the end-user in many ways. As a part of the APC/LG long- term agreement LG has committed to provide module level equivalent (form, fit and function equivalent) panels for a period of ten years. No other commercial glass manufacturer has provided such an agreement. With the use of LG's commercial production manufacturing capabilities, APC/LG can provide the opportunity to procure a lifetime buy for any program with delivery of the entire lot within six months of order placement. This ensures that the entire production program will receive identical glass for every unit. The APC/LG relationship works where others have failed due to the number of years spent cultivating the mutual trust and respect necessary for establishing such a partnership, LG's interest in capturing the market share of this niche application, and the magnitude of the initial up-front investment by APC in engineering, tooling, facilities, production equipment, and LCD cell inventory.

GeoDash: Assisting Visual Image Interpretation in Collect Earth Online by Leveraging Big Data on Google Earth Engine

NASA Technical Reports Server (NTRS)

Markert, Kel; Ashmall, William; Johnson, Gary; Saah, David; Mollicone, Danilo; Diaz, Alfonso Sanchez-Paus; Anderson, Eric; Flores, Africa; Griffin, Robert

2017-01-01

Collect Earth Online (CEO) is a free and open online implementation of the FAO Collect Earth system for collaboratively collecting environmental data through the visual interpretation of Earth observation imagery. The primary collection mechanism in CEO is human interpretation of land surface characteristics in imagery served via Web Map Services (WMS). However, interpreters may not have enough contextual information to classify samples by only viewing the imagery served via WMS, be they high resolution or otherwise. To assist in the interpretation and collection processes in CEO, SERVIR, a joint NASA-USAID initiative that brings Earth observations to improve environmental decision making in developing countries, developed the GeoDash system, an embedded and critical component of CEO. GeoDash leverages Google Earth Engine (GEE) by allowing users to set up custom browser-based widgets that pull from GEE's massive public data catalog. These widgets can be quick looks of other satellite imagery, time series graphs of environmental variables, and statistics panels of the same. Users can customize widgets with any of GEE's image collections, such as the historical Landsat collection with data available since the 1970s, select date ranges, image stretch parameters, graph characteristics, and create custom layouts, all on-the-fly to support plot interpretation in CEO. This presentation focuses on the implementation and potential applications, including the back-end links to GEE and the user interface with custom widget building. GeoDash takes large data volumes and condenses them into meaningful, relevant information for interpreters. While designed initially with national and global forest resource assessments in mind, the system will complement disaster assessments, agriculture management, project monitoring and evaluation, and more.

GeoDash: Assisting Visual Image Interpretation in Collect Earth Online by Leveraging Big Data on Google Earth Engine

NASA Astrophysics Data System (ADS)

Markert, K. N.; Ashmall, W.; Johnson, G.; Saah, D. S.; Anderson, E.; Flores Cordova, A. I.; Díaz, A. S. P.; Mollicone, D.; Griffin, R.

2017-12-01

Collect Earth Online (CEO) is a free and open online implementation of the FAO Collect Earth system for collaboratively collecting environmental data through the visual interpretation of Earth observation imagery. The primary collection mechanism in CEO is human interpretation of land surface characteristics in imagery served via Web Map Services (WMS). However, interpreters may not have enough contextual information to classify samples by only viewing the imagery served via WMS, be they high resolution or otherwise. To assist in the interpretation and collection processes in CEO, SERVIR, a joint NASA-USAID initiative that brings Earth observations to improve environmental decision making in developing countries, developed the GeoDash system, an embedded and critical component of CEO. GeoDash leverages Google Earth Engine (GEE) by allowing users to set up custom browser-based widgets that pull from GEE's massive public data catalog. These widgets can be quick looks of other satellite imagery, time series graphs of environmental variables, and statistics panels of the same. Users can customize widgets with any of GEE's image collections, such as the historical Landsat collection with data available since the 1970s, select date ranges, image stretch parameters, graph characteristics, and create custom layouts, all on-the-fly to support plot interpretation in CEO. This presentation focuses on the implementation and potential applications, including the back-end links to GEE and the user interface with custom widget building. GeoDash takes large data volumes and condenses them into meaningful, relevant information for interpreters. While designed initially with national and global forest resource assessments in mind, the system will complement disaster assessments, agriculture management, project monitoring and evaluation, and more.

Molecular structures guide the engineering of chromatin

PubMed Central

Tekel, Stefan J.

2017-01-01

Abstract Chromatin is a system of proteins, RNA, and DNA that interact with each other to organize and regulate genetic information within eukaryotic nuclei. Chromatin proteins carry out essential functions: packing DNA during cell division, partitioning DNA into sub-regions within the nucleus, and controlling levels of gene expression. There is a growing interest in manipulating chromatin dynamics for applications in medicine and agriculture. Progress in this area requires the identification of design rules for the chromatin system. Here, we focus on the relationship between the physical structure and function of chromatin proteins. We discuss key research that has elucidated the intrinsic properties of chromatin proteins and how this information informs design rules for synthetic systems. Recent work demonstrates that chromatin-derived peptide motifs are portable and in some cases can be customized to alter their function. Finally, we present a workflow for fusion protein design and discuss best practices for engineering chromatin to assist scientists in advancing the field of synthetic epigenetics. PMID:28609787