Behaviour of adipose-derived canine mesenchymal stem cells after superparamagnetic iron oxide nanoparticles labelling for magnetic resonance imaging

Background: Therapy with mesenchymal stem cells (MSCs) has been reported to provide beneficial effects in the treatment of neurological and orthopaedic disorders in dogs. The exact mechanism of action is poorly understood. Magnetic resonance imaging (MRI) gives the opportunity to observe MSCs after clinical administration. To visualise MSCs with the help of MRI, labelling with an MRI contrast agent is necessary. However, it must be clarified whether there is any negative influence on cell function and viability after labelling prior to clinical administration. Results: For the purpose of the study, seven samples with canine adipose-derived stem cells were incubated with superparamagnetic iron oxide nanoparticles (SPIO: 319.2 µg/mL Fe) for 24 h. The internalisation of the iron particles occurred via endocytosis. SPIO particles were localized as free clusters in the cytoplasm or within lysosomes depending on the time of investigation. The efficiency of the labelling was investigated using Prussian blue staining and MACS assay. After 3 weeks the percentage of SPIO labelled canine stem cells decreased. Phalloidin staining showed no negative effect on the cytoskeleton. Labelled cells underwent osteogenic and adipogenic differentiation. Chondrogenic differentiation occurred to a lesser extent compared with a control sample. MTT-Test and wound healing assay showed no influence of labelling on the proliferation. The duration of SPIO labelling was assessed using a 1 Tesla clinical MRI scanner and T2 weighted turbo spin echo and T2 weighted gradient echo MRI sequences 1, 2 and 3 weeks after labelling. The hypointensity caused by SPIO lasted for 3 weeks in both sequences. Conclusions: An Endorem labelling concentration of 319.2 µg/mL Fe (448 µg/mL SPIO) had no adverse effects on the viability of canine ASCs. Therefore, this contrast agent could be used as a model for iron oxide labelling agents. However, the tracking ability in vivo has to be evaluated in further studies

Superconducting fluctuations in small grains - the Universal Hamiltonian and the reduced BCS model

Small superconducting grains are discussed in the frameworks of both the reduced BCS Hamiltonian and the Universal Hamiltonian. It is shown that fluctuations of electrons in levels far from the Fermi energy dominate superconducting properties in small and ultrasmall grains. Experimental consequences related to the spin susceptibility and persistent currents of grains and rings with weak electron-electron interactions are discussed.Comment: Contribution to the proceedings of "Fluctuations and phase transitions in superconductors", Nazareth Ilit, Israel, June 10-14, 200

Bildungsgerechtigkeit und Weiterbildung: Implikationen aus der Adressaten- und der Professionsforschung

Der Beitrag beleuchtet das Thema aus zwei Forschungsperspektiven. Die Adressatenforschung zeigt, dass sich Bildungs(un)gerechtigkeit bereits früh im Lebenslauf manifestiert und über die Lebensspanne eher verschärft, denn verringert. Weiterbildung kann aber kompensierend und chancenausgleichend wirken, was professionstheoretisch zu belegen ist. Entscheidend ist bei der Programmplanung das Grundprinzip der Teilnehmendenorientierung und die Ungleichbehandlung von Ungleichem

El prudencialismo táctico de Baltasar Gracián

Nos quejamos del poco valor humano y ético de muchos políticos de nuestro tiempo, pero no es difícil encontrar antecedentes del daño que puede hacer al bien común no comprender la misión de servicio a los demás que tienen tanto la vida política como cualquier puesto de dirección en las organizaciones humanas

La educación política en la antigüedad clásica griega

En la Antigüedad clásica la participación política era considerada de la máxima importancia y definitoria del hombre libre; ser hombre era ser ciudadano. Esto implicaba a su vez la necesidad e importancia determinante de una formación orientada en dos dimensiones: participación ciudadana responsable y preparación para gobernar competentemente. Los principales filósofos políticos de entonces han tratado profunda y muy acertadamente este asunto; tanto es así, que muchos especialistas contemporáneos afirman con pesimismo: «hoy día la única novedad son los clásicos», también porque abordaron temas de gran actualidad para hoy avant la lettre. Incluso un apretado resumen, como se ofrece en este artículo, acerca del modo que abordaron esta educación política los principales autores griegos de ese período, puede ayudar a exhumar interesantes ideas que son como un rico filón de inspiración para programas hodiernos de formación política inspirados en los clásicos.Political participation in the ancient Greek society was considered of the outmost importance, defining the free man: to be man was to be a citizen. This fact emphasized the need and importance of a formation oriented in two dimensions: responsible citizenship participation and preparation for government. The main Greek political philosophers dealt with these topics in depth and very rightly up to the extent that many contemporary specialists state with pessimism: «nowadays, the only novelty are the classics» also because they analyzed topics of outmost current importance. Even a short abstract – as the one in the present paper – about political education by the most important Greek authors in the classic period, may help to extract interesting ideas to inspire the modern programs of political formation based on the classical authors

El buen gobernante en la antigüedad clásica. Indagación de un enfoque sapiencial en Plutarco [Crónica]

Texto leído en la defensa de la tesis doctoral realizada en la Facultad Eclesiástica de Filosofía de la Universidad de Navarra, el día 11 de febrero de 2011. Dirigió la tesis el Prof. Rafael Alvira. El tribunal estuvo compuesto por los profesores: José Ángel García Cuadrado (presidente), Ángel Luis González, Rafael Alvira, Kurt Spang, Javier Vergara (secretario)

Discrete mechanics and optimal control for constrained systems

The equations of motion of a controlled mechanical system subject to holonomic constraints may be formulated in terms of the states and controls by applying a constrained version of the Lagrange-d’Alembert principle. This paper derives a structure-preserving scheme for the optimal control of such systems using, as one of the key ingredients, a discrete analogue of that principle. This property is inherited when the system is reduced to its minimal dimension by the discrete null space method. Together with initial and final conditions on the configuration and conjugate momentum, the reduced discrete equations serve as nonlinear equality constraints for the minimization of a given objective functional. The algorithm yields a sequence of discrete configurations together with a sequence of actuating forces, optimally guiding the system from the initial to the desired final state. In particular, for the optimal control of multibody systems, a force formulation consistent with the joint constraints is introduced. This enables one to prove the consistency of the evolution of momentum maps. Using a two-link pendulum, the method is compared with existing methods. Further, it is applied to a satellite reorientation maneuver and a biomotion problem

Minimizing complications during retropubic radical prostatectomy - is ureteral stenting necessary?

<p>Abstract</p> <p>Objectives and aims</p> <p>To avoid damage to the ureters during bladder neck preparation in radical prostatectomy for prostate cancer, it may be helpful to insert ureteral stents temporarily or to intravenously administer indigo carmine dye for enhanced visualisation of ureteric orifices. We evaluated our bladder neck preserving technique at radical prostatectomy with regard to ureteric injuries.</p> <p>Patients and methods</p> <p>We analysed 369 consecutive radical prostatectomies operated in our clinic in a bladder neck preserving technique. The following parameters were assessed in this retrospective study: number of prophylactic ureteric stent insertions, application of indigo carmine dye, observed injuries of the ureters by the surgeon, postoperative increase of serum creatinine and postoperative status of kidney ultrasound.</p> <p>Results</p> <p>In 7/369 prostatectomies (1.90%) a ureteric stent insertion was performed, indigo carmine was not applied to any patient at all, yet no intraoperative injury of a ureter was observed by a surgeon. No revision was necessary due to a ureteral injury within the observation period of one year after surgery. In 17 patients with preoperative normal creatinine value a pathological value was observed on the first postoperative day (mean 1.4 mg/dl). In these patients no consecutive postrenal acute renal failure was observed, no hydronephrosis was monitored by ultrasound and no further intervention was necessary.</p> <p>Conclusions</p> <p>Bladder neck preserving operation technique does not implicate the need of prophylactic ureteric stent insertions and has no higher incidence of ureteric injuries.</p

Laser-induced disassembly of a graphene single crystal into a nano-crystalline network

We report about investigations of time-dependent structural modifications in single crystal graphene due to laser irradiation even at moderate power levels of 1mW in a diffraction limited spot. The structural modifications have been characterized by in situ scanning confocal Raman spectroscopy, atomic force height microscopy and transport studies. The time evolution of the Raman spectrum reveals two different effects: on a short time scale, dopants, initially present on the flake, are removed. The longer time scale behavior points to a laser induced gradual local decomposition of single crystal graphene into a network of interconnected nano-crystallites with a characteristic length scale of approximately 10 nm due to bond-breaking. The broken bonds offer additional docking sites for adsorbates as confirmed in transport and AFM height studies. These controlled structural modifications may for instance be valuable for enhancing the local reactivity and trimming graphene based gas sensors.Comment: 16 pages, 4 figure