Facility for validating technologies for the autonomous space rendezvous and docking to uncooperative targets

We present the latest advancements in the air-bearing facility installed at La Sapienza’s GN Lab in the School of Aerospace Engineering. This facility has been utilized in recent times to validate robust control laws for simultaneous attitude control and vibration active damping. The instrumentation and testbed have been restructured and enhanced to enable simulations of close proximity operations. Relative pose determination, accomplished through visual navigation as either an auxiliary or standalone system, is the first building block. Leveraging the acquired knowledge, optimal guidance and control algorithms can be tested for contactless operations (e.g. on-orbit inspection), as well as berthing and docking tasks

A revisited and general Kane’s formulation applied to very flexible multibody spacecraft

Abstract. Current space missions require predicting the spacecraft dynamics with considerable reliability. Among the various components of a spacecraft, subsystems like payload, structures, and power depend heavily on the dynamic behavior of the satellite during its operational life. Therefore, to ensure that the results obtained through numerical simulations correspond to the actual behavior, an accurate dynamical model must be developed. In this context, an implementation of Kane’s method is presented to derive the dynamical equations of a spacecraft composed of both rigid and flexible bodies connected via joints in tree topology. Starting from the kinematics of two generic interconnected bodies, a systematic approach is derived and the recursive structure of the equations is investigated. The Kane’s formulation allows a relatively simple derivation of the equation of motion while obtaining the minimum set of differential equations, which implies lower computational time. On the other hand, this formulation excludes reaction forces and torques from the dynamical equations. Nevertheless, in this work a strategy to compute them a posteriori without further numerical integrations is presented. Flexibility is introduced through the standard modal decomposition technique, so that modal shapes obtained by FEA software can be directly utilized to characterize the elastic motion of the flexible bodies. A spacecraft composed of a rigid bus and several flexible appendages is modeled and numerical simulations point out that this systematic method is very effective for this illustrative example

Benzene with Alkyl Chains Is a Universal Scaffold for Multivalent Virucidal Antivirals.

Most viruses start their invasion by binding to glycoproteins' moieties on the cell surface (heparan sulfate proteoglycans [HSPG] or sialic acid [SA]). Antivirals mimicking these moieties multivalently are known as broad-spectrum multivalent entry inhibitors (MEI). Due to their reversible mechanism, efficacy is lost when concentrations fall below an inhibitory threshold. To overcome this limitation, we modify MEIs with hydrophobic arms rendering the inhibitory mechanism irreversible, i.e., preventing the efficacy loss upon dilution. However, all our HSPG-mimicking MEIs only showed reversible inhibition against HSPG-binding SARS-CoV-2. Here, we present a systematic investigation of a series of small molecules, all containing a core and multiple hydrophobic arms terminated with HSPG-mimicking moieties. We identify the ones that have irreversible inhibition against all viruses including SARS-CoV-2 and discuss their design principles. We show efficacy in vivo against SARS-CoV-2 in a Syrian hamster model through both intranasal instillation and aerosol inhalation in a therapeutic setting (12 h postinfection). We also show the utility of the presented design rules in producing SA-mimicking MEIs with irreversible inhibition against SA-binding influenza viruses

An antiviral trap made of protein nanofibrils and iron oxyhydroxide nanoparticles

Minimizing the spread of viruses in the environment is the first defence line when fighting outbreaks and pandemics, but the current COVID-19 pandemic demonstrates how difficult this is on a global scale, particularly in a sustainable and environmentally friendly way. Here we introduce and develop a sustainable and biodegradable antiviral filtration membrane composed of amyloid nanofibrils made from food-grade milk proteins and iron oxyhydroxide nanoparticles synthesized in situ from iron salts by simple pH tuning. Thus, all the membrane components are made of environmentally friendly, non-toxic and widely available materials. The membrane has outstanding efficacy against a broad range of viruses, which include enveloped, non-enveloped, airborne and waterborne viruses, such as SARS-CoV-2, H1N1 (the influenza A virus strain responsible for the swine flu pandemic in 2009) and enterovirus 71 (a non-enveloped virus resistant to harsh conditions, such as highly acidic pH), which highlights a possible role in fighting the current and future viral outbreaks and pandemics

Large needle aspiration biopsy and galectin-3 determination in selected thyroid nodules with indeterminate FNA-cytology

Thyroid fine-needle aspiration biopsy (FNA)-cytology is widely used for the preoperative characterisation of thyroid nodules but this task is difficult for follicular lesions, which often remain undefined. We propose a strategy for improving the preoperative characterisation of selected follicular thyroid proliferations, which is based on large needle aspiration biopsy (LNAB) and galectin-3 expression analysis. Eighty-five thyroid specimens were obtained by LNAB (20-gauge needles) from thyroid nodules with indeterminate follicular FNA-cytology. Aspirated material was processed as a tissue microbiopsy to obtain cell blocks for both cyto/histo-morphological evaluation and galectin-3 expression analysis, by using a purified monoclonal antibody to galectin-3 and a biotin-free immunoperoxidase staining method. Preoperative diagnosis was compared to the final histology. LNAB and cell-block technique allow a preliminary distinction between nodules with a homogeneous microfollicular/trabecular structure, as frequently observed in tumours, and lesions with mixed normo–micro–macrofollicular architecture, as observed in goitre. Furthermore, LNAB provides optimal substrates for galectin-3 expression analysis. Among 85 cases tested, 14 galectin-3-positive cases were discovered preoperatively (11 thyroid cancers and three adenomas confirmed at the final histology), whereas galectin-3-negative cases were 71 (one carcinoma and 70 benign proliferations at the final histology). Sensitivity, specificity and diagnostic accuracy of this integrated morphologic and phenotypic diagnostic approach were 91.6, 97.2 and 95.3%, respectively. In conclusion, LNAB plus galectin-3 expression analysis when applied preoperatively to selected thyroid nodules candidate to surgery can potentially reduce unnecessary thyroid resections

Does spatial locative comprehension predict landmark-based navigation?

In the present study we investigated the role of spatial locative comprehension in learning and retrieving pathways when landmarks were available and when they were absent in a sample of typically developing 6- to 11-year-old children. Our results show that the more proficient children are in understanding spatial locatives the more they are able to learn pathways, retrieve them after a delay and represent them on a map when landmarks are present in the environment. These findings suggest that spatial language is crucial when individuals rely on sequences of landmarks to drive their navigation towards a given goal but that it is not involved when navigational representations based on the geometrical shape of the environment or the coding of body movements are sufficient for memorizing and recalling short pathways

Detection and molecular characterisation of thyroid cancer precursor lesions in a specific subset of Hashimoto's thyroiditis

Hashimoto's thyroiditis (HT) represents the most common cause of hypothyroidism and nonendemic goiter, but its clinical and pathological heterogeneity opens the question if this disease should be more properly considered as a spectrum of different thyroid conditions rather than as a single nosological entity. In this study, we analysed 133 cases of HT for the expression of galectin-3, a lectin molecule involved in malignant transformation, apoptosis and cell cycle control. An unexpected expression of galectin-3 was demonstrated in a subset of HT together with the presence of HBME-1, c-met and cyclin-D1 that are also involved in malignant transformation and deregulated cell growth. Furthermore, a loss of allelic heterozygosity in a specific cancer-related chromosomal region was demonstrated in some HT harbouring galectin-3-positive follicular cells, by using laser capture microdissection. On the basis of the morphological and molecular findings we identified four subsets of HT: (a) HT with classic features of chronic autoimmune thyroiditis; (b) HT associated to hyperplastic/adenomatous lesions; (c) HT harbouring thyroid cancer precursors; (d) HT associated to unequivocal thyroid microcarcinomas. Our findings provide a well-substantiated morphological and molecular demonstration that HT may include a spectrum of different thyroid conditions ranging from chronic autoimmune thyroiditis to thyroiditis triggered by specific immune-response to cancer-related antigens