Guided vasculogenic sprouting induced by the immobilized fusion construct CaM-VEGF120

This project is intended to utilize an immobilized bio-active first generation fusion constructed cytokine inducing in receptive cell lines guided vasculogenic development. This research through the assembly, expression and purification of a bio-active molecule the CaM-VEGF120 fusion construct permitted the creation of a first generation smart-gel platform. Cell culture bringing together HUVECs or cBOECs with soluble or immobilized CaM-VEGF120 coupled with a type-I collagen platform are the main components intended to induce guided vascular sprouting. Purification of the CaM-VEGF120 was achieved utilizing HIC coupled with size exclusion chromotography. Mass Spectrometry and cellular augmentation noted by survivability and proliferation suggests the correct CaM-VEGF120 properties were achieved. Cell culture interactive changes were recorded utilizing fluorescent and phase microscopy. The 66 KDa dimeric CaM-VEGF120 was able to phosphorylate the cytoplasmic Tyr1175 localized to the C-terminal portion of the transmembrane VEGFR2. GNP immobilized CaM-VEGF120 induced VEGFR2 expressing cell lines as were imaged over a week’s period recording vascular pseudo-tube formation. These events resulting from contact with the immobilized CaM-VEGF120 and VEGFR2 induced activity thus presenting in vitro guided vascular pseudo-tube development. This research is being pursued utilizing HUVEC and cBOECs as guided vascular pseudo-tube structural formation is possible. This successful model implies a first generation model for physiological vascular development having therapeutic applications

An experience of modularity through design

We aim to utilise the experiences of a marine industry-based design team to determine the need for research into a modular design methodology in an industrial environment. In order to achieve this we couple the outcome of a current design project with the findings of a recent literature survey with the objectives of firstly, clarifying why a methodology is required and, secondly, defining the key elements which the methodology would have to realise or address. The potential benefits of modularity have long been recognised in the shipbuilding industry. Many shipbuilders adopt a 'module' approach to ship construction whereby the ship structure is separated into a number of large structural 'blocks' to ease manufacture and manoeuvrability during construction. However, as understanding of the capabilities of modularity as a design tool develops there is increased interest in capitalising on the differing life phase benefits of modularity such as reduced design costs and time, increased ease of maintenance, upgrade, re-use, redesign and standardisation across individual products and product families. This is especially pertinent in naval shipbuilding where the maintenance of a class of ship requires that all previously designed ships in that class must be of similar outfitting and must be able to interface with the new ship, in terms of propulsion, weapons, communications and electronics, and thus often require some form of retrofit. Therefore, many shipbuilders are moving from viewing modularity as a purely 'manufacturing' principle to a design centred principle. However, as noted by Chang and Ward 'none of the design theories or tools in the mechanical world serves as an articulate procedure for designers to follow in practising modular design'. Thus, despite the identification of a need to introduce modular principles at an earlier stage than detail design and construction, there is little aid in the form of tools, techniques and methodologies for designers in practice

Emerging Space Technologies: Macro-scale On-orbit Manufacturing

Advanced additive manufacturing (AM) technologies have the potential to change the way in which satellites and spacecraft are deployed in orbit by removing traditional launch constraints, whether faring volume or launch loads, and allowing space structures to become larger, lighter and more capable with integrated features. These same approaches may also be exploited for on-orbit servicing, thereby potentially extending the operable lifetime of space infrastructure and increasing cost effectiveness. This paper will provide an overview of the key issues associated with on-orbit manufacturing and discuss the use of AM technologies and investigate the next wave of emerging space technologies enabled by on-orbit manufacturing

Emerging space technologies: macro-scale on-orbit manufacturing

Advanced additive manufacturing (AM) technologies have the potential to change the way in which satellites and spacecraft are deployed in orbit by removing traditional launch constraints, whether faring volume or launch loads, and allowing space structures to become larger, lighter and more capable with integrated features. These same approaches may also be exploited for on-orbit servicing, thereby potentially extending the operable lifetime of space infrastructure and increasing cost effectiveness. This paper will provide an overview of the key issues associated with on-orbit manufacturing and discuss the use of AM technologies and investigate the next wave of emerging space technologies enabled by on-orbit manufacturing

System architectures assessment based on network metrics

Characterising system architectures and describing a system’s properties using quantitative metrics is required for the comparison and evaluation of engineering systems. The aim of this article is to discuss the assessment of system architectures based on network metrics derived from literature. In this paper, network metrics such as interaction density, Newman modularity index (Q), centrality measures, cyclomatic number, and graph energy measure are included into a methodological approach for evaluating five hypothetical system architecture patterns: bus-modular, sequential, hierarchical, core-periphery and integral. Network and graph theory offer a conceptual approach to model and analyse engineering system architectures. The contribution of the article is a network metrics assessment founded on describing emergent system architecture properties as integrality, modularity, centrality, cyclicality and complexity for holistically assessing system architectures. The network metrics offer quantitative tools to gain valuable insights and can function as decision aid tools during the redesign and early development of engineering systems

A network science-based assessment methodology for robust modular system architectures during early conceptual design

This article describes a methodology to assess, during the early conceptual design stage, the robustness, and modularity of engineering system architectures, which integrates concepts from network science with engineering systems. The application specifically focuses on the architecture of the power, propulsion, and cooling systems of a naval ship. The methodology incorporates a binary Design Structure Matrix as the basis for an assessment of redundancy and modularity effects on robustness, in response to disruption of modules in the architecture. Robustness is used to drive the module selection, which supports the formulation of a robust module configuration subject to the level of redundancy in the system architecture. The case study results demonstrated: redundancy promotes robustness of the architecture and enables modularity; however, high levels of redundancy in comparison to medium level redundancy does not significantly improve robustness. The novel contribution of this article relates to the combined quantitative assessment of redundancy, modularity and robustness in a collective methodology. This methodology supports conceptual design decision making, allowing early prediction of compliance of requirements that enable cost, development time and survivability targets to be achieved

A network tool to analyse and improve robustness of system architectures

The architecture of a system is decided at the initial stage of the design. However, the robustness of the system is not usually assessed in detail during the initial stages, and the exploration of alternative system architectures is limited due to the influence of previous designs and opinions. This article presents a novel network generator that enables the analysis of the robustness of alternative system architectures in the initial stages of design. The generator is proposed as a network tool for system architectures dictated by their configuration of source and sink components structured in a way to deliver a particular functionality. Its parameters allow exploration with theoretical patterns to define the main structure and hub structure, vary the number, size, and connectivity of hub components, define source and sink components and directionality at the hub level and adapt a redundancy threshold criterion. The methodology in this article assesses the system architecture patterns through robustness and modularity network based metrics and methods. Two naval distributed engineering system architectures are examined as the basis of reference for the simulated networks. The generator provides the capacity to create alternative complex system architecture options with identifiable patterns and key features, aiding in a broader explorative and analytical, in-depth, time and cost-efficient initial design process

Network-based metrics for assessment of naval distributed system architectures

The architecture of a system is generally established at the end of the conceptual design phase where sixty to eighty percent of the lifetime system costs are committed. The architecture influences the system’s complexity, integrality, modularity and robustness. However, such properties of system architecture are not typically analytically evaluated early on during the conceptual process. System architectures are defined using qualitative experience, and the early stage decisions are subject to the judgement of stakeholders. This article suggests a set of network-based metrics that can potentially function as early evaluation indicators to assess complexity, integrality, modularity and robustness of distributed system architectures during conceptual design. A new robustness metric is proposed that assesses the ability of architecture to support a level functional requirement of the system after a disruption. The new robustness metric is evaluated by an electrical simulation software (MATPOWER). A ship vulnerability assessment software (SURVIVE) was used to find potential disruptive events. Two technical case studies examining existing naval distributed system architectures are elaborated. Conclusions on the network modelling and metrics as early aids to assess system architectures and to choose among alternatives during the conceptual decision phase are presented

An architectural description for the application of MBSE in complex systems

The design of a complex warship is a multi-disciplinary effort which often encounters major challenges, particularly with respect to integration across interfaces in the System of Systems (SoS). In principle, the goal of Model Based Systems Engineering (MBSE) with respect to system design is to provide a means of capturing and communicating the system design in a structured, consistent, and coherent fashion; that can be easily assessed by engineering teams and quickly analysed using queries and toolsets. The focus of this paper is to investigate the potential to achieve a consistent description, identify a viable methodology that minimises mismatch in requirements and to avoid an extended design lifecycle. This study highlights the need to develop a generic Architectural Description (AD) that is based on a common ontology which would clearly define the fundamental tenets of applying state-of-the-art Architectural Frameworks (AFs) in naval ship design. An investigation on the effectiveness and accuracy of a graph-based approach is needed to assess whether it is possible to create a ‘Rosetta stone’ for AFs, which links any two or more different model viewpoints in different AF’s using the approach

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty