FM127: Systemic metal ion levels in patients with modular neck total hip arthroplasties: a prospective cohort study

There is increasing evidence that modular neck stems are prone to corrosion-related complications. Recent studies showed elevated metal ions levels and occasional pseudotumor formation in patients with such implants. The purpose of this study was to compare systemic metal-ion levels in patients after primary THA with modular neck stems to those of patients after non-modular implants. To our knowledge, this is the first cohort study including a control group, THA without CoCr heads and dry-assembled neck-stem connections. Methods: 50 patients after THA at a minimum follow-up of 1 year have been selected for the study. Patients with multiple prosthesis or other implants have been deselected. All received a cementless SPS stem from Symbios (Ti6Al4V). 40 patients have the modular neck (CoCr) version and 10 a monobloc version. All bearings were either ceramic-ceramic or ceramic-polyethylene to minimize other sources of CoCr ion release. In the modular group, the neck was chosen pre-operatively based on a 3D planning, allowing for a dry assembly of the stem and neck on the back table before implantation. A plasma system coupled to mass spectrometry was used for a complete elementary quantification in blood and serum separately. Clinical outcome was measured using the Oxford Hip Score. Results : Complete data sets of 29 patients (24 in the modular neck-group (10male, mean age 63y, 35-84y) and 5 in the monobloc-group (3 male, 69 y, 51-83y) are available to date. Mean Co blood levels were .95 ug/L (.14-12.4) in the modular group vs .27 ug/L (.10-.73) in the monobloc group (p=.2). Respective values for Cr were significantly higher in the modular group (.99 g/L; range .75-1.21) compared to those in the monobloc group (.74 g/L ;.62-.86; p=.001). No significant difference was found when comparing serum levels. 5/24 patients had Co levels above 1 g/L (12/24 for Cr), which is by some considered as a relevant elevation. The maximum Co level was measured in an asymptomatic patient. The Oxford Hip Scores were similar in both groups. Conclusion: Cr levels were significantly elevated in the modular neck group compared to those in the monobloc group. 1/24 patients with a modular prosthesis exhibited Co levels, which are beyond the threshold accepted even for metal-on-metal bearing couples. These results have contributed to our decision to abandon the use of modular neck stems. Routine follow-up including annual measurements of systemic CoCr concentrations should be considered.

Arquitectura, integració i implementació d'un projecte modular J2EE

L'objectiu principal del TFC consisteix en la creació d'una complexa estructura modular J2EE basada i mantinguda per Maven, amb la utilització com frameworks Spring, Hibernate i Flex principalment. Aquesta estructura permet reprendre el desenvolupament inicial, nous desenvolupaments i manteniments d'una aplicació, amb un cost temporal mínim per la part de l'equip de desenvolupament.

Una Proposta d'avaluació per competències a la universitat en una estructura modular

En aquest treball presentem una proposta d’avaluació per competències en una estructura modular que és fruit de la nostra experiència com a professors universitaris. Volem oferir un instrument d’avaluació conjunta per a tot l’equip de professors de mòdul que sigui vàlid, àgil i operatiu i que permeti donar feedback a cada estudiant del seu procés d’aprenentatge. Després de presentar els trets més singulars de la nostra institució i exposar alguns referents teòrics en relació a l’avaluació de competències, indiquem quines són les competències que hem seleccionat i aprofundim en la metodologia de treball i avaluació de les mateixes. Aquesta metodologia varia segons els espais acadèmics: gran grup, grup mig i seminari. A cadascun d’aquests espais es treballen i s’avaluen unes competències determinades, tot i que d’una forma més genèrica totes es desenvolupen conjuntament ens els tres àmbits. Considerem que és fonamental assenyalar que no es tracta d’avaluar “per assignatures” ni “per activitats”, sinó d’avaluar les competències que es desenvolupen a través de les matèries i de les propostes de treball que s’especifiquen en el pla docent.. L’ instrument d’avaluació que presentem possibilita la participació de tot el professorat implicat en el mateix mòdul i alhora permet que cada professor utilitzi els seus propis indicadors d’avaluació, aconseguint harmonitzar les dinàmiques de treball individuals i de grup.

Monte Carlo study of a kinetic lattice model with random diffusion of disorder

We report Monte Carlo results for a nonequilibrium Ising-like model in two and three dimensions. Nearest-neighbor interactions J change sign randomly with time due to competing kinetics. There follows a fast and random, i.e., spin-configuration-independent diffusion of Js, of the kind that takes place in dilute metallic alloys when magnetic ions diffuse. The system exhibits steady states of the ferromagnetic (antiferromagnetic) type when the probability p that J>0 is large (small) enough. No counterpart to the freezing phenomena found in quenched spin glasses occurs. We compare our results with existing mean-field and exact ones, and obtain information about critical behavior.

Reaction-diffusion lattice gas: Theory and computer results

We report on the study of nonequilibrium ordering in the reaction-diffusion lattice gas. It is a kinetic model that relaxes towards steady states under the simultaneous competition of a thermally activated creation-annihilation $(reaction$) process at temperature T, and a diffusion process driven by a heat bath at temperature T?T. The phase diagram as one varies T and T, the system dimension d, the relative priori probabilities for the two processes, and their dynamical rates is investigated. We compare mean-field theory, new Monte Carlo data, and known exact results for some limiting cases. In particular, no evidence of Landau critical behavior is found numerically when d=2 for Metropolis rates but Onsager critical points and a variety of first-order phase transitions.

Ising critical behavior of a non-Halmiltonian lattice system

We study steady states in d-dimensional lattice systems that evolve in time by a probabilistic majority rule, which corresponds to the zero-temperature limit of a system with conflicting dynamics. The rule satisfies detailed balance for d=1 but not for d>1. We find numerically nonequilibrium critical points of the Ising class for d=2 and 3.

Ground-state order and spin-lattice coupling in tetrahedral spin systems Cu2Te2O5X2 (X = Br or Cl)

High-resolution ac susceptibility and thermal conductivity measurement on Cu2Te2O5X2 (X=Br,Cl) single crystals are reported. For Br-sample, sample dependence prevents one from distinguishing between possibilities of magnetically ordered and spin-singlet ground states. In Cl-sample a three-dimensional transition at 18.5 K is accompanied by almost isotropic behavior of susceptibility and almost switching behavior of thermal conductivity. Thermal conductivity studies suggest the presence of a tremendous spin-lattice coupling characterizing Cl- but not Br-sample. Below the transition Cl-sample is in a complex magnetic state involving AF order but also the elements consistent with the presence of a gap in the excitation spectrum.

Adverse tissue reaction to corrosion at the neck-stem junction after modular primary total hip arthroplasty.

Complications related to the neck-stem junction of modular stems used for total hip arthroplasty (THA) are generating increasing concern. A 74-year-old male had increasing pain and a cutaneous reaction around the scar 1 year after THA with a modular neck-stem. Imaging revealed osteolysis of the calcar and a pseudo-tumour adjacent to the neck-stem junction. Serum cobalt levels were elevated. Revision surgery to exchange the stem and liner and to resect the pseudo-tumour was performed. Analysis of the stem by scanning electron microscopy and by energy dispersive X-ray and white light interferometry showed fretting corrosion at the neck-stem junction contrasting with minimal changes at the head-neck junction. Thus, despite dry assembly of the neck and stem on the back table at primary THA, full neck-stem contact was not achieved, and the resulting micromotion at the interface led to fretting corrosion. This case highlights the mechanism of fretting corrosion at the neck-stem interface responsible for adverse local tissue reactions. Clinical and radiological follow-up is mandatory in patients with dual-modular stems.

Modelo para una autoevaluación modular en una institución educativa (BADI)

Una eficaz acción educativa obliga necesariamente a plantearse en profundidad la autoevaluación como modelo de cambio y la participación de todos los estamentos de la comunidad educativa. Un mayor o menor grado de participación viene a ser un indicador que nos permite valorar cualquier propuesta de «calidad», «reforma» o «innovación». El modelo B.A.D.I. yen especial su instrumento modular, responde a las exigencias particulares de reflexión, análisis y toma de decisiones que se realiza en cada centro para responder adecuadamente a cualquier planteamiento innovador. Los principios fundamentales de este modelo se resumen en: A. Es un modelo de concepción organicista, estamental, con definición ideológica. B. Responde a un enfoque fundamentalmente rogeriano. C. Participa de los enfoques social, abierto, dinámico, cultural y positivo. Comparte la teoría moderna de la organización y sus indicadores se agrupan en cuatro fases: Criterial, presupuestaria, metodológica e informativa. D. Se identifica con los modelos centrados en la evaluación de cambio, de forma especial con la autoevaluación. La flexibilidad que caracteriza al modelo viene dado por el instrumento modular de área o de criterio, como resultado de la participación y el consenso de todos los estamentos de la institución educativa.

A modular tethering complex for endosomal recycling.

How proteins migrate through the interconnected organelles of the endolysosomal system is poorly understood. A piece of the puzzle has been added with the identification of a complex of tethering factors that functions in the recycling of proteins towards the cell surface.

Harmonising the Modular Product Range

Työn tavoitteena on analysoida KONEen hissien ovituoteperheitä ja harmonisoida modulaarista ovituotevalikoimaa niin, että tulos olisi mahdollisimman suotuisa KONEelle sekä sen sidosryhmille. Harmonisointi toteutetaan, koska KONEen tuotevalikoima on erittäin laaja ja monimutkainen ja siitä syystä erittäin kallis ja vaikea hallita ja ylläpitää. Tavoitteena on selvittää myös termejä modulaarisuus ja tuotealusta olennaisen kirjallisuuden pohjalta. Nykyään yritysten täytyy kehittää tuotevalikoimaa jatkuvasti. Yrityksen koko tuotevalikoiman varioituvuus tulisi kuitenkin pitää järkevissä rajoissa. Moduuleita ja tuotealustoja pitäisi käyttää jakamaan tuotteiden avainelementtejä ja lisäämään varioituvuutta helposti hallittavalla tavalla. Kannattamattomat ja matalavolyymiset tuotteet kuluttavat yrityksen niukkoja resursseja. Tällaiset tuotteet tulisi poistaa tuotevalikoimasta, mutta ei ilman harkintaa. Kannattama-tonkin tuote voi olla erittäin arvokas asiakkaalle ja tällaisen tuotteen hylkääminen voi olla yritykselle pitkällä tähtäimellä erittäin kohtalokasta. Työn tuloksena oli harmonisointiehdotus KONEen AMD-oville ja selvitys harmonisoinnin vaikutuksista. Harmonisointi KONEella päätettiin toteuttaa siten, että matalavolyymiset tuotteet siirrettiin erikoistuotteiden valikoimaan. Myös kustannusanalyysi tukee harmonisointipäätöstä laskentajärjestelmän puutteista huolimatta.

Assignment markets with the same core

[spa] En el contexto de los juegos de asignación bilaterales, estudiamos el conjunto de matrices asociadas a mercados de asignación con el mismo nucleo. Se proporcionan condiciones sobre las entradas de la matriz que aseguran que los juegos de asignación asociados tienen el mismo núcleo. Se prueba que este conjunto de matrices que dan lugar al mismo núcleo forman un semirretículo con un número finito de elementos minimales y un único máximo. Se da una caracterización de estos elementos minimales. También se proporciona una condición suficiente para obtener un retículo.

Designing a modular, open and expandable Bluetooth-platform

Lähitulevaisuudessa langattomien järjestelmien kaupalliset mahdollisuudet tulevat olemaan valtavia. Tutkiaksemme tulevia tarpeita, tässä diplomityössä esitellään kuinka voidaan suunnitella ja toteuttaa avoin langaton asiakas-palvelin järjestelmä. Järjestelmänä päätettiin käyttää Bluetooth:ia. Tutkituista langattomista standardeista Bluetooth sopii parhaiten akkukäyttöiselle laitteelle, jonka tulee olla monipuolinen. Lisäksi Bluetooth:iin on liitetty suuria kaupallisia odotuksia ja yksi työn tavoitteista olikin tutkia, ovatko nämä odotukset realistisia. Bluetooth:iin havaittiin liittyvän paljon ylimainontaa ja, sen todettiin olevan monimutkainen. Sillä on kuitenkin paljon ominaisuuksia ja erilaisten käyttöprofiilien avulla sitä voidaan käyttää monenlaisiin tehtäviin. Suunniteltu järjestelmä ajaa socket-palvelinta Bluetooth-yhteyden päällä. Tietyntyyppiseen liikenteeseen erikoistuneet socket:t tarjoavat vaaditun laajennattavuuden. Palvelin toteutetiin Linux-säikeenä ja se hallitsee Bluetooth protokollapinoa sekä sovelluksia, joita suoritetaan palvelimella. Näiden sovelluksien palvelut ovat muiden käytössä Bluetooth:n kautta.

Assignment markets with the same core

[spa] En el contexto de los juegos de asignación bilaterales, estudiamos el conjunto de matrices asociadas a mercados de asignación con el mismo nucleo. Se proporcionan condiciones sobre las entradas de la matriz que aseguran que los juegos de asignación asociados tienen el mismo núcleo. Se prueba que este conjunto de matrices que dan lugar al mismo núcleo forman un semirretículo con un número finito de elementos minimales y un único máximo. Se da una caracterización de estos elementos minimales. También se proporciona una condición suficiente para obtener un retículo.