Analysis of a wearable robotic system for ankle rehabilitation

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. As one of the most commonly injured joints of the human body, the ankle is often subject to sprains or fractures that require motion assistance to recover mobility. Whereas physiotherapists usually perform rehabilitation in one-on-one sessions with patients, several successful robotic rehabilitation solutions have been proposed in the last years. However, their design is usually bulky and requires the patient to sit or stand in a static position. A lightweight wearable device for ankle motion assistance, the CABLEankle, is here proposed for motion ankle exercising in rehabilitation and training. The CABLEankle is based on a cable-driven S-4SPS parallel architecture, which enables motion assistance over the large motion range of the human ankle in a walking gait. The proposed mechanism design is analyzed with kinematic and static models, and the force closure workspace of the mechanism is discussed with analytical results. Finally, the feasibility of the proposed design is investigated through numerical simulations over the ankle motion range as a characterization of the peculiar motion

Destruction of dimethyl ether and methyl formate by collisions with He+^+

To correctly model the abundances of interstellar complex organic molecules (iCOMS) in different environments, both formation and destruction routes should be appropriately accounted for. While several scenarios have been explored for the formation of iCOMs via grain and gas-phase processes, much less work has been devoted to understanding the relevant destruction pathways, with special reference to (dissociative) charge exchange or proton transfer reactions with abundant atomic and molecular ions such as He$^+$, H$_3^+$ and HCO$^+$. By using a combined experimental and theoretical methodology we provide new values for the rate coefficients and branching ratios (BRs) of the reactions of He$^+$ ions with two important iCOMs, namely dimethyl ether (DME) and methyl formate (MF). We also review the destruction routes of DME and MF by other two abundant ions, namely H$_3^+$ and HCO$^+$. Based on our recent laboratory measurements of cross sections and BRs for the DME/MF + He$^+$ reactions over a wide collision energy range, we extend our theoretical insights on the selectivity of the microscopic dynamics to calculate the rate coefficients $k(T)$ in the temperature range from 10 to 298 K. We implement these new and revised kinetic data in a general model of cold and warm gas, simulating environments where DME and MF have been detected. Due to stereodynamical effects present at low collision energies, the rate coefficients, BRs and temperature dependences here proposed differ substantially from those reported in KIDA and UDfA, two of the most widely used astrochemical databases. These revised rates impact the predicted abundances of DME and MF, with variations up to 40% in cold gases and physical conditions similar to those present in prestellar coresComment: accepted for publication in Astronomy and Astrophysics (manuscript no. AA/2018/34585), 10 pages, 3 figure

Ab Initio Spectroscopic Investigation of Pharmacologically Relevant Chiral Molecules: The Cases of Avibactam, Cephems, and Idelalisib as Benchmarks for Antibiotics and Anticancer Drugs

Abstract: The ability to accurately measure or predict several physicochemical properties of molecules which play a role as active substances in drugs can be of strategic importance for pharmacological applications, in addition to its possible interest in fundamental research. Chirality is a relevant feature in the characterization of drug molecules: enantiomers can show different pharmacological activity and adverse effects. The ability to separate stereoisomers and to assign their absolute configuration can thus be crucial. Circular dichroism (CD) spectra are a useful tool to distinguish between enantiomers. In this work we apply an in-house developed code, based on an efficient DFT approach for circular dichroism, to fully characterize the molecular optical properties in the case of few selected fundamental molecules for current medical and pharmaceutical research, namely avibactam, as representative of non b-lactam inhibitors, two cephems (cefepime and cefoxitin), as examples of b-lactam antibiotics, and idelalisib, as a recent relevant anticancer active substance to treat major leukemias. For the above molecules, in addition to their optical absorption spectra, we calculate their CD spectra within state-of-the-art computational techniques. We then investigate both the conformational and chemical sensitivity of absorption and CD spectra for the chosen molecules. The outcomes of the present research could be of fundamental importance to gain additional information on molecules involved in therapeutic protocols for severe diseases or in drug design

A Concerted Variational Strategy for Investigating Rare Events

A strategy for finding transition paths connecting two stable basins is presented. The starting point is the Hamilton principle of stationary action; we show how it can be transformed into a minimum principle through the addition of suitable constraints like energy conservation. Methods for improving the quality of the paths are presented: for example, the Maupertuis principle can be used for determining the transition time of the trajectory and for coming closer to the desired dynamic path. A saddle point algorithm (conjugate residual method) is shown to be efficient for reaching a ``true'' solution of the original variational problem.Comment: 3 figures, accepted for publication in Journal of Chemical Physic

HeritageBot platform for service in Cultural Heritage frames

A service robot for Cultural Heritage frames is proposed as a novel robotic platform with a modular design for both ground locomotion and flight capability. The peculiarities of the system are discussed by performance evaluation via simulation. A prototype has been built and tested both to prove the feasibility of the proposed design and to characterize its operation performance

The Optimal Permeation of Cyclic Boronates to Cross the Outer Membrane via the Porin Pathway

We investigated the diffusion of three cyclic boronates formulated as beta-lactamase inhibitors through the porin OmpF to evaluate their potential to cross OM via the porin pathway. The three nonbeta-lactam molecules diffuse through the porin eyelet region with the same mechanism observed for beta-lactam molecules and diazobicyclooctan derivatives, with the electric dipole moment aligned with the transversal electric field. In particular, the BOH group can interact with both the basic ladder and the acidic loop L3, which is characteristic of the size-constricted region of this class of porins. On one hand, we confirm that the transport of small molecules through enterobacter porins has a common general mechanism; on the other, the class of cyclic boronate molecules does not seem to have particular difficulties in diffusing through enterobacter porins, thus representing a good scaffold for new anti-infectives targeting Gram-negative bacteria research

Design and test of a gripper prototype for horticulture products

This paper describes the design of a gripper for horticulture product grasping. The design solution has been achieved by means of a systematic approach by evaluating all the possible architecture. The proposed structure is optimized and numerically simulated. Then, a prototype has been built and tested in laboratory. The design process and test results are discussed to show the efficiency of the built prototype with lab test

New V. cholerae atypical El Tor variant emerged during the 2006 epidemic outbreak in Angola

<p>Abstract</p> <p>Background</p> <p><it>V. cholerae </it>is the etiological agent of cholera, a major public health concern in most developing countries. Virulence of <it>V. cholerae </it>relies on the powerful cholera toxin, encoded by the CTX prophage. The emergence of new pathogenic variants in the recent years has been mostly associated with new CTX prophage rearrangements.</p> <p>Results</p> <p>In this retrospective study, we show that the epidemic <it>V. cholerae </it>O1 El Tor strain responsible for the 2006 outbreak in Angola is clonally and genetically different from El Tor strains circulating in the 1990s in the same area. Strains from 2006 carry ICE<it>Vch</it>Ang3 of the SXT/R391 family. This ICE is associated with a narrower multidrug resistance profile compared to the one conferred by plasmid p3iANG to strains of the 1990s. The CTX prophage carried by 2006 El Tor strains is characterized by <it>rstR^ET</it>and <it>ctxB^Cla</it>alleles organized in a RS1-RS2-Core array on chromosome I. Interestingly, the newly emerging atypical strain belongs to a clade previously known to comprise only clinical isolates from the Indian subcontinent that also contain the same ICE of the SXT/R391 family.</p> <p>Conclusions</p> <p>Our findings remark the appearance of a novel <it>V. cholerae </it>epidemic variant in Africa with a new CTXΦ arrangement previously described only in the Indian Subcontinent.</p

New <i>V. cholerae</i> atypical El Tor variant emerged during the 2006 epidemic outbreak in Angola

Background V. cholerae is the etiological agent of cholera, a major public health concern in most developing countries. Virulence of V. cholerae relies on the powerful cholera toxin, encoded by the CTX prophage. The emergence of new pathogenic variants in the recent years has been mostly associated with new CTX prophage rearrangements. Results In this retrospective study, we show that the epidemic V. cholerae O1 El Tor strain responsible for the 2006 outbreak in Angola is clonally and genetically different from El Tor strains circulating in the 1990s in the same area. Strains from 2006 carry ICEVchAng3 of the SXT/R391 family. This ICE is associated with a narrower multidrug resistance profile compared to the one conferred by plasmid p3iANG to strains of the 1990s. The CTX prophage carried by 2006 El Tor strains is characterized by rstRET and ctxBCla alleles organized in a RS1-RS2-Core array on chromosome I. Interestingly, the newly emerging atypical strain belongs to a clade previously known to comprise only clinical isolates from the Indian subcontinent that also contain the same ICE of the SXT/R391 family. Conclusions Our findings remark the appearance of a novel V. cholerae epidemic variant in Africa with a new CTXΦ arrangement previously described only in the Indian Subcontinent.</br