Contributors:Ernest Essoun, Ruiyao Wang, Manuel A.S. Aquino
Valent-averaged diruthenium(II,III) tetraacetate, [Ru2(μ-O2CCH3)4(H2O)2](PF6), was reacted with various bidentate P–N donor ligands. These reactions led to the partial displacement of bridging carboxylate groups and concomitant cleavage of the Ru–Ru bond, producing novel complexes. Disassembly reactions with the aminophosphines; diphenyl-2-pyridylphosphine (dpppy) and 2-(diphenylphosphino)ethylamine (dppea), produced homoleptic tris-chelated species, fac-[Ru(dpppy-P,N)3](PF6)2 (III) and mer-[Ru(dppea-P,N)3](PF6)2 (VI), respectively. Disassembly reactions with aromatic aminophosphines; 2-(diphenylphosphino)methylpyridine (dppmpy) and 2-(diphenylphosphino)ethylpyridine (dppepy), led to heteroleptic tris-chelated complexes cis,cis,trans-[Ru(dppmpy-P,N)2(η2-O2CCH3)](PF6)·MeOH (IV) and cis,cis,trans-[Ru(dppepy-P,N)2(η2-O2CCH3)](PF6) (V), respectively, whereas reaction with the non-cyclic aminophosphine, 3-(diphenylphosphino)-1-propylamine (dpppa) and the non-cyclic iminophosphine, 2-(diphenylphosphino)benzylidinebenzylamine (dppbba), led to the heteroleptic tris-chelated complexes cis,cis,trans-[Ru(dpppa-P,N)2(η2-O2CCH3)](PF6·EtOH (VII) and cis,cis,trans-[Ru(dppbba-P,N)2(η2-O2CCH3)](PF6)·2MeOH·H2O (VIII), respectively. All complexes were fully characterized. Electrochemical studies (CV, OSWV) showed that the homoleptic tris-chelated complexes had higher oxidation potentials (Epa) than the corresponding heteroleptic tris-chelated complexes, due to the weak π-acceptor ability of the acetate group. Complex (III) has the highest Epa as it contains the strongest combination of π-accepting groups. The Epa values of the heteroleptic complexes were found to be in the order: dppbba (CHN)>dppmpy, dppepy (py)>dpppa (NH2), since amines are much poorer π-acceptors than pyridyl and imino groups. Complexes (III), (VI) and (VII) showed irreversible oxidation waves, while complexes (IV), (V) and (VIII) displayed quasi-reversible one electron processes.
Contributors:Wilian M. dos Santos, Glauco A.P. Caurin, Adriano A.G. Siqueira
Active orthosis is one of the main research topics in the field of motor recovery. This paper deals with the design and control of an active knee orthosis driven by a customized rotary Series Elastic Actuator (SEA). The proposed actuator includes a DC motor, a worm gear and a customized torsion spring. Since the elastic element is the most important component in SEA design, a finite element analysis of the spring is performed to meet the specific requirements for knee assistance. Torque and impedance control are implemented to ensure secure interaction with the patient and to enable new strategies for rehabilitation. The torque controller, cascaded with an inner motor velocity control loop, is based on H∞ criterion to achieve good system performance with relation to parametric uncertainties and external disturbances. The impedance control is implemented using a PD position controller in cascade with the torque controller, where the outer position controller determines the desired torque according to position and velocity errors and impedance parameters. A variable impedance control strategy is then implemented to show the possibility to regulate the impedance of the knee joint during walking. Experiments considering the interaction between the subject and the active orthosis are performed to evaluate the proposed controllers.
The objective of this study was to assess the prevalence of restless legs syndrome (RLS) among patients with stroke and to examine the anatomical correlation between location of stroke and RLS symptoms.
Contributors:Riccardo Pettinari, Fabio Marchetti, Agnese Petrini, Claudio Pettinari, Giulio Lupidi, Belén Fernández, Antonio Rodríguez Diéguez, Giorgio Santoni, Massimo Nabissi
A series of ruthenium(II) arene complexes (arene=p-cymene, hexamethylbenzene and benzene) containing dibenzoylmethane ligand (DBMH) of formula [(arene)Ru(DBM)Cl] and their ionic derivatives bearing PTA (1,3,5-triaza-7-phosphaadamantane), of formula [(arene)Ru(DBM)(PTA)]X (X=PF6- or SO3CF3-) have been synthesized and fully characterized. The solid-state structures of five complexes have been determined by single-crystal X-ray diffraction. These ruthenium materials exhibit intense photoluminescence emission at room temperature in the solid state. All complexes effectively bind to calf thymus DNA through intercalative/electrostatic interactions with more affinity for DNA minor groove. Finally, the antitumor activity of both ligand and complexes was evaluated against the U266 and RPMI human multiple myeloma cell lines, and some of them showed a cytotoxic and pro-apoptotic effect toward both cell lines.
Contributors:Aleksandra Zatajska, Miłosz Siczek, Anna Skarżyńska, Piotr Smoleński
Reactions of [NH4]2[PdCl4] with N-protonated or N-alkyl-1,3,5-triaza-7-phosphaadamantane iodide salts [PTA-R]I (R=H, Me, Et, nPr, nBu) give the water-soluble palladium(II) complexes of type [PdI3(PTA-R)] in isolated yields of 62–81%. All these compounds have been fully characterized by IR and NMR spectroscopies and elemental analyses. Their molecular structures were confirmed by single crystal X-ray diffraction analysis. The complexes belong to the relatively unusual zwitterionic, coordination compounds. Moreover, they constitute, as far as we are aware, the first reported examples of palladium compounds bearing N-alkyl-1,3,5-triaza-7-phosphaadamantane ligands. The complexes catalyze efficiently Heck reaction of iodobenzene and n-butyl acrylate as well as iodobenzene and substituted styrenes, under mild conditions in water as a solvent.
This paper presents a novel data driven technique for the detection and isolation of faults, which generate impacts in a rotating equipment. The technique is built upon the principles of empirical mode decomposition (EMD), envelope analysis and pseudo-fault signal for fault separation. Firstly, the most dominant intrinsic mode function (IMF) is identified using EMD of a raw signal, which contains all the necessary information about the faults. The envelope of this IMF is often modulated with multiple vibration sources and noise. A second level decomposition is performed by applying pseudo-fault signal (PFS) assisted EMD on the envelope. A pseudo-fault signal is constructed based on the known fault characteristic frequency of the particular machine. The objective of using external (pseudo-fault) signal is to isolate different fault frequencies, present in the envelope . The pseudo-fault signal serves dual purposes: (i) it solves the mode mixing problem inherent in EMD, (ii) it isolates and quantifies a particular fault frequency component. The proposed technique is suitable for real-time implementation, which has also been validated on simulated fault and experimental data corresponding to a bearing and a gear-box set-up, respectively.
Contributors:Meiyu Gai, Johannes Frueh, Tieyan Si, Narsiu Hu, Gleb B. Sukhorukov, Qiang He
The collision phenomena of self-propelled micro-plate motors are significantly different from classical life-less particles. The Janus micro-plate motors used in this study are 5 and 10μm in diameter and driven by catalytic decomposition of hydrogen peroxide. Periodically oscillating oxygen bubbles drive the motor in rugged straight or spiral motion. Since the inertia effect of mass is no longer important for slow motion in low Reynold number liquid, the momentum law of collision shows some new characteristics due to the constant self-propelling force. We found a bounce back collision and a linear collision between the bubbles of one motor and the micromotor plates as well as between 2 microplates and present a basic theoretical concept. In addition we show experimentally that these 2D particles are able to destroy emerging gas bubbles. More complex collision dynamics may exist for a higher concentration of self-propelled motors.
Photoreactions of 4-pentenyl-1-cyanonaphthalenes yield spirocyclic products along with [4+2] cycloadducts. Photoreactions of 5-phenyl derivatives produce a product having tricyclo[6.3.0.01,4]undecadiene skeleton. Formation of angular triquinanes takes place in photoreactions of cycloalkene-linked cyanonaphthalenes. The observation demonstrates that π–π arene ring interactions, steric hindrance, and suitable locations of reaction sites in syn and anti singlet exciplexes govern the modes followed in intramolecular photoreactions of 4-alkenyl-1-cyanonaphthalenes.
Fluorosis is an endemic global problem causing male reproductive impairment. F mediates male reproductive toxicity in mice down-regulating 63 genes involved in diverse biological processes - apoptosis, cell cycle, cell signaling, chemotaxis, electron transport, glycolysis, oxidative stress, sperm capacitation and spermatogenesis. We predicted the miRNAs down-regulating these 63 genes using TargetScan, DIANA and MicroCosm. The prediction tools identified 3059 miRNAs targeting 63 genes. Of the predicted interactions, 11 miRNAs (mmu-miR-103, -107, -122, -188a, -199a-5p, -205, -340-5p, -345-3p, -452-5p, -499, -878-3p) were commonly found in the three tools utilized and seven miRNAs (miR-9-5p, miR-511-3p, miR-7b-5p, miR-30e-5p, miR-17-5p, miR-122-5p and miR-541-5p) targeting six genes (Traf3, Rock2, Rgs8, Atp1b2, Cacna2d1 and Aldoa) were already validated experimentally in mice. The miRNA-mRNA network of the predicted miRNAs with its respective targets revealed the complex interaction within a biological process leading to sperm dysfunction on exposure to F. Our findings not only suggest that the predicted miRs furnish evidence, but also have the potential to serve as non-invasive biomarkers on F-induced sperm dysfunction. Our data contribute towards elucidating the function of miRNAs in the fluoride induced infertility. miRNA molecular pathways in F intoxication will open new avenues on the use of antagomirs in recovering fertility.