Study of technology requirements for atmosphere braking to orbit about Mars and Venus. Volume 1 - Summary, January - October 1967

Technology requirements and spacecraft design studies for atmosphere braking to orbit about Mars and Venu

Enzymatic synthesis of antibody-human serum albumin conjugate for targeted drug delivery using tyrosinase from Agaricus bisporus

Highly specific targeted drug delivery devices can be obtained with antibody-human serum albumin (mAb-HSA) conjugates. However, their conventional production involves several reaction steps including chemical modification and activation of both proteins followed by cross-linking often involving toxic chemicals. Here, we describe the enzymatic synthesis of mAb-HSA conjugates for targeted drug delivery devices using tyrosinase from Agaricus bisporus under mild reaction conditions (pH 6.8, 25 [degree]C). Reaction conditions were optimized by using fluorescence labeled HSA to facilitate SDS-PAGE analysis with fluorescence scanning. Enzymatic cross-linking in the presence of natural low molecular weight phenolic compounds (e.g. caffeic acid) resulted in reaction products in the molecular weight range of [similar]216 kDa, corresponding to mAb-HSA conjugates. The composition of the conjugates was confirmed with tryptic digestion followed by LC-MS/MS analysis of the resulting peptide fragments. Successful binding of mAb-HSA conjugates (in contrast to free HSA) to MHC II molecules, located on antigen-presenting cells, was demonstrated by both ELISA and flow cytometry analysis.This work has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement NMP4-LA-2009-228827 NANOFOL and FWF, DK: Metabolic and Cardiovascular Disease: W1226-B18. We thank Tamara Reiter, Graz University of Technology for technical support with SEC; Exbio from the Czech Republic for providing the mAbs and Britta Obrist, Medical University of Graz and the Austrian Centre of Industrial Biotechnology, for technical assistance with LC-MS/MS analysis

A methodology for boost-glide transport technology planning

A systematic procedure is presented by which the relative economic value of technology factors affecting design, configuration, and operation of boost-glide transport can be evaluated. Use of the methodology results in identification of first-order economic gains potentially achievable by projected advances in each of the definable, hypersonic technologies. Starting with a baseline vehicle, the formulas, procedures and forms which are integral parts of this methodology are developed. A demonstration of the methodology is presented for one specific boost-glide system

Monte Carlo Simulations of HIV Capsid Protein Homodimer

Capsid protein (CA) is the building block of virus coats. To help understand how the HIV CA proteins self-organize into large assemblies of various shapes, we aim to computationally evaluate the binding affinity and interfaces in a CA homodimer. We model the N- and C-terminal domains (NTD and CTD) of the CA as rigid bodies and treat the five-residue loop between the two domains as a flexible linker. We adopt a transferrable residue-level coarse-grained energy function to describe the interactions between the protein domains. In seven extensive Monte Carlo simulations with different volumes, a large number of binding/unbinding transitions between the two CA proteins are observed, thus allowing a reliable estimation of the equilibrium probabilities for the dimeric vs monomeric forms. The obtained dissociation constant for the CA homodimer from our simulations, 20–25 μM, is in reasonable agreement with experimental measurement. A wide range of binding interfaces, primarily between the NTDs, are identified in the simulations. Although some observed bound structures here closely resemble the major binding interfaces in the capsid assembly, they are statistically insignificant in our simulation trajectories. Our results suggest that although the general purpose energy functions adopted here could reasonably reproduce the overall binding affinity for the CA homodimer, further adjustment would be needed to accurately represent the relative strength of individual binding interfaces

Life-Cycle Cost Estimation for High-Speed Vehicles: from the engineers’ to the airline’s perspective

This paper aims at upgrading the holistic Cost Estimation methodology for High-Speed Vehicles already developed by Politecnico di Torino and the European Space Agency (ESA) to encompass different stakeholders’ perspectives. In details, the presented methodology combines International Air Transport Association (IATA) best practices with a detailed Life- Cycle Cost (LCC) assessment, which includes the evaluation of Research, Development, Test and Evaluation (RDTE) Costs, Production costs and of Direct and Indirect Operating Costs (DOC and IOC). The integrated approach allows to further extend the capabilities of the inhouse developed HyCost tool to support all the actors of the product value-chain (including engineers, manufacturers, airlines and customers) in assessing the economic sustainability of a newly under-development high-speed vehicle. However, considering the need of providing all these cost analyses perspectives since the early design stages, the derived Cost Estimation Relationships are mainly derived on statistical bases. To cope with the uncertainties that affect the initial statistical population and consequently, the CERs, this paper presents each cost item together with the estimation of related prediction intervals. Finally, results of the application of the upgraded cost estimation methodology and of the upgraded tool to the LAPCAT MR2.4 high-speed civil transport are reported and discussed

ACE2 is the critical in vivo receptor for SARS-CoV-2 in a novel COVID-19 mouse model with TNF-and IFN?-driven immunopathology

Despite tremendous progress in the understanding of COVID-19, mechanistic insight into immunological, disease-driving factors remains limited. We generated maVie16, a mouse-adapted SARS-CoV-2, by serial passaging of a human isolate. In silico modeling revealed how only three Spike mutations of maVie16 enhanced interaction with murine ACE2. maVie16 induced profound pathology in BALB/c and C57BL/6 mice, and the resulting mouse COVID-19 (mCOVID-19) replicated critical aspects of human disease, including early lymphopenia, pulmonary immune cell infiltration, pneumonia, and specific adaptive immunity. Inhibition of the proinflammatory cyto-kines IFN? and TNF substantially reduced immunopathology. Importantly, genetic ACE2-deficiency completely prevented mCOVID-19 development. Finally, inhalation therapy with recombinant ACE2 fully protected mice from mCOVID-19, revealing a novel and efficient treatment. Thus, we here present maVie16 as a new tool to model COVID-19 for the discovery of new therapies and show that disease severity is determined by cytokine-driven immunopathology and critically dependent on ACE2 in vivo. © Gawish et al

Augmented Latent Membrane Protein 1 Expression from Epstein-Barr Virus Episomes with Minimal Terminal Repeats▿

The major oncogene of the Epstein-Barr virus (EBV), latent membrane protein 1 (LMP1), can be expressed from either of two promoters, ED-L1 or L1-TR, producing mRNAs of 2.8 kb or 3.5 kb, respectively. L1-TR, active in nasopharyngeal carcinoma and Hodgkin's lymphoma, is located within the first of a highly variable reiteration of terminal repeat (TR) sequences that are joined by random recombination upon circularization of the linear genome at entry into cells. To determine whether the resultant TR number affects LMP1 promoter activity, we isolated single-cell clones bearing episomes of distinct TR numbers (6TR to 12TR) from epithelial cells newly infected with EBV. LMP1 mRNA levels correlated directly with the quantity of LMP1 protein expressed but varied inversely to TR number. Unexpectedly, the 3.5-kb transcript predominated only at lower TR reiterations. Diminished L1-TR activity in the context of a higher TR count was confirmed with a green fluorescent protein (GFP) reporter construct driven by L1-TR. Various levels of LMP1, expressed from virus isogenic in all but TR number, produced divergent morphological and growth phenotypes in each cell clone. Abundant LMP1 in 6TR cells yielded a relatively cytostatic state compared to the proliferative one produced by intermediate and smaller amounts in 8TR and 12TR clones. These findings suggest that the diversification of TR number, inherent in a round of EBV reactivation and reinfection, may itself be a component of the oncogenic process. The replicative burst preceding onset of many EBV-linked cancers may increase the likelihood that LMP1 levels compatible with clonal outgrowth are achieved in a subset of infected cells