Extension of Murray's law using a non-Newtonian model of blood flow.

BACKGROUND: So far, none of the existing methods on Murray's law deal with the non-Newtonian behavior of blood flow although the non-Newtonian approach for blood flow modelling looks more accurate. MODELING: In the present paper, Murray's law which is applicable to an arterial bifurcation, is generalized to a non-Newtonian blood flow model (power-law model). When the vessel size reaches the capillary limitation, blood can be modeled using a non-Newtonian constitutive equation. It is assumed two different constraints in addition to the pumping power: the volume constraint or the surface constraint (related to the internal surface of the vessel). For a seek of generality, the relationships are given for an arbitrary number of daughter vessels. It is shown that for a cost function including the volume constraint, classical Murray's law remains valid (i.e. SigmaR(c) = cste with c = 3 is verified and is independent of n, the dimensionless index in the viscosity equation; R being the radius of the vessel). On the contrary, for a cost function including the surface constraint, different values of c may be calculated depending on the value of n. RESULTS: We find that c varies for blood from 2.42 to 3 depending on the constraint and the fluid properties. For the Newtonian model, the surface constraint leads to c = 2.5. The cost function (based on the surface constraint) can be related to entropy generation, by dividing it by the temperature. CONCLUSION: It is demonstrated that the entropy generated in all the daughter vessels is greater than the entropy generated in the parent vessel. Furthermore, it is shown that the difference of entropy generation between the parent and daughter vessels is smaller for a non-Newtonian fluid than for a Newtonian fluid.

Occlusion postcontusionnelle de l'artère et de la veine centrale de la rétine [Post-concussion occlusion of the central artery and vein of the retina]

BACKGROUND: Combined simultaneous occlusion of the central retinal artery and central retinal vein occurs very rarely and has been observed in patients with systemic disorders such as leukaemia. CASE REPORT: We report a case of a young man who suffered a combined retinal vascular occlusion with occlusion of the posterior ciliary arteries following blunt trauma to the face with massive haematoma of the lids. To our knowledge, this is the first time that such a sequence of events has been recorded.

Consumers' use of nutrition-related endorsement symbol to help their purchase decisions: An extension of the theory of planned behaviour

Tutkimuksessa haluttiin selvittää, mitkä tekijät vaikuttavat ravintoon liittyvän suositusmerkin käyttöön kuluttajan ostopäätöksen apuna. Tutkimuksen viitekehyksen pohjaksi valittiin suunnitellun toiminnan teoria, joka on osoittautunut selittämään hyvin useaa ravintoon- ja terveyteen liittyvää käyttäytymistä. Tutkimustoteutettiin kyselytutkimuksella, jonka aineisto kerättiin Internetissä julkaistulla kyselylomakkeella. Tulokset osoittivat, että kuluttajan aikomus käyttää suositusmerkkiä oli mallin vahvin selittäjä. Lisäksi merkin käyttöä selitti kuluttajan kokema sisäinen kontrolli, johon ulkoinen kontrolli vahvasti vaikuttaa. Ostopäätössitoutumisen havaittiin vaikuttavan aikomuksen ja todellisen merkin käytön väliseen yhteyteen. Yleisesti tulokset osoittivat, että kuluttajilla on aikomusta käyttää merkkiä, mutta todellinen käyttö on huomattavasti vähäisempää.

The Effect of Switching Ranibizumab to Aflibercept in Refractory Cases of Macular Edema Secondary to Ischemic Central Vein Occlusion.

Background: Macular edema resulting from central retinal vein occlusion is effectively treated with anti-vascular endothelial growth factor injections. However, some patients need monthly retreatment and still show frequent recurrences. The purpose of this study was to evaluate the visual and anatomic outcomes of refractory macular edema resulting from ischemic central retinal vein occlusion in patients switched from ranibizumab to aflibercept intravitreal injections. Patients and Methods: We describe a retrospective series of patients followed in the Medical Retina Unit of the Jules Gonin Eye Hospital for macular edema due to ischemic central retinal vein occlusion, refractory to monthly retreatment with ranibizumab, and changed to aflibercept. Refractory macular edema was defined as persistence of any fluid at each visit one month after last injection during at least 6 months. All patients had to have undergone pan-retinal laser scan. Results: Six patients were identified, one of whom had a very short-term follow-up (excluded from statistics). Mean age was 57 ± 12 years. The mean changes in visual acuity and central macular thickness from baseline to switch were + 20.6 ± 20.3 ETDRS letters and - 316.4 ± 276.6 µm, respectively. The additional changes from before to after the switch were + 9.2 ± 9.5 ETDRS letters and - 248.0 ± 248.7 µm, respectively. The injection intervals could often be lengthened after the switch. Conclusions: Intravitreal aflibercept seems to be a promising alternative treatment for macular edema refractory to ranibizumab in ischemic central retinal vein occlusion.

Recurrent Macular Edema in Central Retinal Vein Occlusion Treated with Intravitreal Ranibizumab using a Modified Treat and Extend Regimen.

Background: The aim of this study was to evaluate the stability over time of the individually defined interval of intravitreal ranibizumab injection (IVR) for the treatment of recurrent macular edema (ME) in central retinal vein occlusion (CRVO). Patients and Methods: A case series of treatment naïve patients followed in the Jules Gonin Eye Hospital for macular edema due to central retinal vein occlusion is presented. Patients were treated monthly with IVR until complete absence of fluid on qualitative SD-OCT with a minimum of 5 monthly IVR. Thereafter, they were followed according to a modified treat and extend regimen (mTER). Results: Twelve eyes (12 patients) with ME due to CRVO were included. The mean follow-up period was 31.3 months. Analysis showed that best corrected visual acuity (BCVA), central macular thickness and qualitative spectral domain optical coherence tomography (SD-OCT) showed comparable results under monthly interval, after titration of an individualized interval and when performed in a series. 78 % of treating intervals were within ± 2 weeks of the first individually adjusted interval. The mean first defined interval was 4.3 weeks and the mean interval over time was 5.5 weeks (p = 0.003). There was a trend towards longer interval over time. Conclusion: The adjusted interval of retreatment of patients with ME due to CRVO showed a high stability with a trend toward longer duration over time. An mTER regimen seems to be valuable to follow patients with ME with good stabilization of VA.

Extension des prestations de type "équipe mobile" aux foyers socio-éducatifs: projet pilote dans le canton de Vaud [Extension of mobile team services to socio-educational home: pilot project in the Vaud canton].

L'objectif principal de ce projet d'extension des prestations, de type Antenne d'intervention dans le milieu pour enfants et adolescents (AIMEA) aux foyers socio-éducatifs pour l'ensemble du canton de Vaud, vise à décloisonner les champs socio-éducatifs et pédopsychiatriques. 64 patients ont fait l'objet d'une évaluation au cours de la phase pilote (après une année de fonctionnement). De plus, une enquête de satisfaction a été effectuée soit à la fin du suivi, soit à la fin de la phase pilote de ce projet (au 31.12.2012). Cette expérience très positive, relevée par une grande majorité des acteurs impliqués dans la prise en charge socio-éducative et pédopsychiatrique des mineurs, suscite un désir d'extension des prestations de type équipe mobile à d'autres structures ou à d'autres types de situations. The main objective of this project about mobile team service extension to the socio-educational home of the whole Vaud canton targets to decompartmentalize the socio-educational and youth-psychiatry domains. 64 patient were assessed during this pilot phase (after one-year functioning). In addition, a satisfaction survey was done either at the end of the follow up or at the end of the pilot phase of the project (31.12.2012). This experience was very positive as highlighted by the vast majority of the person involved in the socio-educational and youth-psychiatric domains taking care of youth. A desire of extension of mobile team service to other institutional structure or other situations was expressed.

T-Coffee: a web server for the multiple sequence alignment of protein and RNA sequences using structural information and homology extension

This article introduces a new interface for T-Coffee, a consistency-based multiple sequence alignment program. This interface provides an easy and intuitive access to the most popular functionality of the package. These include the default T-Coffee mode for protein and nucleic acid sequences, the M-Coffee mode that allows combining the output of any other aligners, and template-based modes of T-Coffee that deliver high accuracy alignments while using structural or homology derived templates. These three available template modes are Expresso for the alignment of protein with a known 3D-Structure, R-Coffee to align RNA sequences with conserved secondary structures and PSI-Coffee to accurately align distantly related sequences using homology extension. The new server benefits from recent improvements of the T-Coffee algorithm and can align up to 150 sequences as long as 10 000 residues and is available from both http://www.tcoffee.org and its main mirror http://tcoffee.crg.cat.

Integrin-Specific Mechanoresponses to Compression and Extension Probed by Cylindrical Flat-Ended AFM Tips in Lung Cells

Cells from lung and other tissues are subjected to forces of opposing directions that are largely transmitted through integrin-mediated adhesions. How cells respond to force bidirectionality remains ill defined. To address this question, we nanofabricated flat-ended cylindrical Atomic Force Microscopy (AFM) tips with ~1 µm2 cross-section area. Tips were uncoated or coated with either integrin-specific (RGD) or non-specific (RGE/BSA) molecules, brought into contact with lung epithelial cells or fibroblasts for 30 s to form focal adhesion precursors, and used to probe cell resistance to deformation in compression and extension. We found that cell resistance to compression was globally higher than to extension regardless of the tip coating. In contrast, both tip-cell adhesion strength and resistance to compression and extension were the highest when probed at integrin-specific adhesions. These integrin-specific mechanoresponses required an intact actin cytoskeleton, and were dependent on tyrosine phosphatases and Ca2+ signaling. Cell asymmetric mechanoresponse to compression and extension remained after 5 minutes of tip-cell adhesion, revealing that asymmetric resistance to force directionality is an intrinsic property of lung cells, as in most soft tissues. Our findings provide new insights on how lung cells probe the mechanochemical properties of the microenvironment, an important process for migration, repair and tissue homeostasis.

Fluctuaciones de la extension del casquete glacial de la isla de Livingston (Shetland del sur) desde 1956 hasta 1996.

A partir de documentos cartográficos e imágenes de satélite se constata un 4,31% de reducción de extensión del casquete glacial de la isla Livingston desde 1956 hasta 1996. Se detecta la influencia de factores locales, fundamentalmente de tipo topogr á fico, que condicionan los avances y retrocesos del frente glacial en los diferentes sectores de la costa y se establece un modelo simple en el que se relaciona la reducción del conjunto del casquete con el calentamiento atmosférico experimentado en los últimos decenios en la zona de la Península Antártica.

Traitement percutané de la thrombose veineuse profonde aiguë [Catheter-based treatment for acute deep vein thrombosis].

Plus de la moitié des patients présentant une thrombose veineuse profonde des membres inférieurs développent un syndrome post-thrombotique. Le risque est particulièrement élevé en cas de thrombose de l'axe principal de drainage veineux comprenant la veine fémorale commune et les veines iliaques. Plusieurs études ont démontré que l'incidence du syndrome post-thrombotique peut être diminuée si une recanalisation des veines ilio-fémorales est obtenue dans la phase aiguë. A l'heure actuelle, des techniques de recanalisation percutanées sont proposées à des patients sélectionnés présentant une thrombose ilio-fémorale. Cet article a pour but de résumer les connaissances actuelles sur la recanalisation percutanée de la thrombose veineuse profonde aiguë. Nearly half of patients with acute lower limb deep vein thrombosis (DVT) develop a post-thrombotic syndrome (PTS). This risk is particularly high in case of proximal DVT of the common femoral and iliac vein, the major lower limbs venous outflow vessel. Several studies have demonstrated that PTS incidence can be reduced with early vein recanalisation. Currently, catheter-based recanalisation therapies can be offered to selected patients with acute ilio-femoral deep vein thrombosis. Aim of the present article is to summarize current knowledge on these catheter-based recanalisation therapies.