EFFECT OF QUADRICEP STRENGTH SYMMETRY ON KNEE JOINT SYMMETRY DURING SLS IN ACLR AND HEALTHY INDIVIDUALS

A tear of the anterior cruciate ligament (ACL) is one of the most common and costly injuries for active adults and athletes. This injury causes short- and long-term problems economically through increased health care costs and physically through delayed playing time and early-onset knee osteoarthritis (OA). Athletes returning to high level sports after ACL reconstruction are over four times more likely to reinjure the reconstructed ACL(ACLR) than athletes at lower levels. Risk factors for reinjury are an area of interest for researchers in order to minimize this short-term burden. The high rates of a second ACL tear suggest current inadequate return-to-play (RTP) criteria which focuses on establishing symmetry between the injured and uninjured limb mainly through clinical hop tests and self-reported function surveys such as the KOOS and IKDC. However, to date, the only significant risk factors for a second ACL injury are time after an ACLR and quadricep strength symmetry. Quadricep strength symmetry is most commonly assessed using a dynamometer. However, these devices are not typically found in clinical settings. Thus, a clinically applicable movement that could ultimately be added to the RTP criteria to assess quadricep strength asymmetry is the single leg squat (SLS). PURPOSE: The purpose of this study was to determine the effect of quadriceps strength LSI on knee joint biomechanics LSI during a single leg squat in ACLR and healthy individuals. METHODS: A two cohort (ACLR and healthy) within-groups study design was used to assess the purpose of this study. ACLR individuals (n=10) filled out the KOOS self-report survey. Both healthy (n=10) and ACLR underwent the single leg hop for distance, triple leg hop for distance, and 6m timed hop on both limbs. All participants were then strength assessed on the quadriceps for both limbs using a dynamometer; isometrically at 60 degrees. Lastly, using a 10-camera motion capture system, participants completed 5 SLS per limb as well as a landing task from 75% their maximal hop distance. RESULTS: ACLR participants were split into two groups: those with >90% quadricep strength symmetry and those with 90% ACLR and healthy controls displayed a 3.0 Nm/kg normalized torque for both limbs. This overall suggested that future studies should look at both limbs reaching functionality and strength before RTP, with functionality being defined by absolute values, not the contralateral limb in comparison to the ipsilateral limb

Compréhension du fonctionnement de l'appel à la peur et du role médiateur de la réactance situationnelle en communication préventive de l'anorexie

Anorexia prevention or more widely disorder eating behavior, has a strong social and societal interest. It also presents an academic interest, since this context is under-represented in research. Existing anorexia prevention campaigns use the strategy of fear appeal, despite a non-consensual literature on the level of fear appeal to adopt and the exact functioning of the mechanism. The existing literature also suggests, to explain failure of fear appeal, that there is a situational reactance, even though this has never been validated. Four experiments on young women students, public particularly sensitive to this context, allow us to understand and validate the mechanism of fear appeal in successive mediations and while integrating situational reactance. Through these experiments, it is shown that the message with fear appeal creates a cognitive and emotional state of fear, and perceived severity that will oppositely influence situational reactance. The latter influences the perceived efficacy of recommendation, which in turn determines the success or failure of the message. In parallel, the mediator, but secondary role, of self-efficacy on the perceived efficacy of the recommendation is revealed, as well as the moderator of perceived susceptibility. Furthermore, each study attempts to handle, in addition to the level of fear appeal, various components and characteristics of the message, whose effects on the fear appeal mechanism solve in part, some existing conflicts in the literature. Thus, the role of the components, visual and verbal, on the level of fear felt is examined (studies 1 and 2). The effect of the wording of the recommendation (study 2), as well as the effect of the type of argument (study 3) on the process of fear appeal are analyzed. Finally, the addition of the disgust on fear appeal and the validation process by a behavioral measure yet refine understanding the mechanism of fear appeal (study 4). To conclude, the key preventive effective communication with anorexia use of fear appeals are given and results are discussed and complemented with possible future research directions, some of which are used to overcome the limitations mentioned on this research.A prévention de l'anorexie, et plus largement des troubles de comportement alimentaire, revêt un intérêt social et sociétal fort. Elle comporte également un intérêt académique, ce contexte étant sous-représenté en recherche. Les communications existantes sur la prévention de l'anorexie utilisent la stratégie de l'appel à la peur, malgré une littérature non consensuelle sur le niveau d'appel à adopter et sur le fonctionnement exact du mécanisme. La littérature propose également, pour expliquer l'échec de l'appel à la peur, l'existence d'une réactance situationnelle, sans que celle-ci n'ait jamais été validée. Quatre expérimentations auprès de jeunes femmes étudiantes, public particulièrement sensible dans ce contexte, permettent de comprendre et valider le fonctionnement de l'appel à la peur par médiations successives et en intégrant la réactance situationnelle. Il est montré que le message avec appel à la peur crée un état cognitivo-émotionnel composé de peur et de sévérité perçue qui vont influer de manière opposée sur la réactance situationnelle. Cette dernière influence à son tour la perception d'efficacité de la recommandation, qui déterminera ensuite le succès ou l'échec du message. En parallèle, le rôle médiateur, mais secondaire, de l'auto-efficacité sur l'efficacité perçue de la recommandation est révélé, de même que celui modérateur de la vulnérabilité perçue. En complément de ce résultat, chacune des études s'attache à manipuler, en plus du niveau d'appel à la peur, différentes composantes et caractéristiques du message, dont les effets sur le mécanisme d'appel à la peur permettent de résoudre, en partie, certains conflits existants dans la littérature. Ainsi, le rôle des composantes, visuelle et verbale, sur le niveau ressenti de peur est examiné (études 1 et 2). L'effet de la formulation de la recommandation (étude 2), de même que l'effet du type d'argument (étude 3) sur le processus de l'appel à la peur sont analysés. Enfin, l'ajout du dégoût à l'appel à la peur et la validation du fonctionnement du processus par une mesure comportementale affinent encore la compréhension des mécanismes d'action de l'appel à la peur (étude 4). Pour conclure, les clés d'une communication préventive de l'anorexie efficace avec recours à l'appel à la peur sont données et les résultats discutés et complétés par des voies de recherche possibles, dont certaines permettent de pallier les limites mentionnées pour la présente recherche

Perspectivas y experiencias en el empleo de tecnologias no convencionales en el tratamiento de residuales liquidos

Parte de los residuales que genera la industria y la actividad social son corrientes acuosas, que pueden contener compuestos tóxicos y poco biodegradables, donde el tratamiento biológico analiza la importancia de las técnicas no convencionales en el tratamiento de residuales y la descontaminación de aguas. Entre los procesos novedosos se encuentran el ultrasonido, la oxidación catalítica y los reactores con biomembranas. El ultrasonido se emplea en la degradación de compuestos refractarios que no pueden ser tratados por métodos biológicos, en mejorar la degradación biológica y en la desintegración de lodos. La oxidación catalítica es más prometedora desde el punto de vista económico, para el tratamiento de aguas residuales con contaminantes persistentes. El empleo del carbón activado como catalizador en el tratamiento de residuales por oxidación catalítica abre un camino importante en el uso extensivo de este proceso. Los biorreactores de membranas ofrecen un grupo de ventajas relacionadas con la calidad y su reutilización, la reducción de lodos, la estabilidad del permeado con independencia de picos de carga y menores requerimientos de espacio. Estas tecnologías pueden emplearse combinadas entre sí o con los procesos convencionales. La elección del esquema de tratamiento dependerá de las características del residual a tratar o del agua a recuperar, de los volúmenes y de los requisitos que se establezcan para el agua tratada

Application of sludge-based carbonaceous materials in a hybrid water treatment process based on adsorption and catalytic wet air oxidation

This paper describes a preliminary evaluation of the performance of carbonaceous materials prepared from sewage sludges (SBCMs) in a hybrid water treatment process based on adsorption and catalytic wet air oxidation; phenol was used as the model pollutant. Three different sewage sludges were treated by either carbonisation or steam activation, and the physico-chemical properties of the resultant carbonaceous materials (e.g. hardness, BET surface area, ash and elemental content, surface chemistry) were evaluated and compared with a commercial reference activated carbon (PICA F22). The adsorption capacity for phenol of the SBCMs was greater than suggested by their BET surface area, but less than F22; a steam activated, dewatered raw sludge (SA_DRAW) had the greatest adsorption capacity of the SBCMs in the investigated range of concentrations (<0.05 mol L−1). In batch oxidation tests, the SBCMs demonstrated catalytic behaviour arising from their substrate adsorptivity and metal content. Recycling of SA_DRAW in successive oxidations led to significant structural attrition and a hardened SA_DRAW was evaluated, but found to be unsatisfactory during the oxidation step. In a combined adsorption–oxidation sequence, both the PICA carbon and a selected SBCM showed deterioration in phenol adsorption after oxidative regeneration, but a steady state performance was reached after 2 or 3 cycles

Estimating Virus Production Rates in Aquatic Systems

Viruses are pervasive components of marine and freshwater systems, and are known to be significant agents of microbial mortality. Developing quantitative estimates of this process is critical as we can then develop better models of microbial community structure and function as well as advance our understanding of how viruses work to alter aquatic biogeochemical cycles. The virus reduction technique allows researchers to estimate the rate at which virus particles are released from the endemic microbial community. In brief, the abundance of free (extracellular) viruses is reduced in a sample while the microbial community is maintained at near ambient concentration. The microbial community is then incubated in the absence of free viruses and the rate at which viruses reoccur in the sample (through the lysis of already infected members of the community) can be quantified by epifluorescence microscopy or, in the case of specific viruses, quantitative PCR. These rates can then be used to estimate the rate of microbial mortality due to virus-mediated cell lysis

Zn doped iron oxide nanoparticles with high magnetization and photothermal efficiency for cancer treatment

Magnetic nanoparticles (NPs) are powerful agents to induce hyperthermia in tumours upon the application of an alternating magnetic field or an infrared laser. Dopants have been investigated to alter different properties of materials. Herein, the effect of zinc doping into iron oxide NPs on their magnetic properties and structural characteristics has been investigated in-depth. A high temperature reaction with autogenous pressure was used to prepare iron oxide and zinc ferrite NPs of same size and morphology for direct comparison. Pressure was key in obtaining high quality nanocrystals with reduced lattice strain (27% less) and enhanced magnetic properties. Zn_{0.4}Fe_{2.6}O_{4} NPs. with small size of 10.2 ± 2.5 nm and very high saturation magnetisation of 142 ± 9 emu g_{Fe+Zn}^{−1} were obtained. Aqueous dispersion of the NPs showed long term magnetic (up to 24 months) and colloidal stability (at least 6 d) at physiologically mimicking conditions. The samples had been kept in the fridge and had been stable for four years. The biocompatibility of Zn_{0.4}Fe_{2.6}O_{4} NPs was next evaluated by metabolic activity, membrane integrity and clonogenic assays, which show an equivalence to that of iron oxide NPs. Zinc doping decreased the bandgap of the material by 22% making it a more efficient photothermal agent than iron oxide-based ones. Semiconductor photo-hyperthermia was shown to outperform magneto-hyperthermia in cancer cells, reaching the same temperature 17 times faster whilst using 20 times less material (20 mg_{Fe+Zn} ml^{−1}vs. 1 mg_{Fe+Zn} ml^{−1}). Magnetothermal conversion was minimally hindered in the cellular confinement whilst photothermal efficiency remained unchanged. Photothermia treatment alone achieved 100% cell death after 10 min of treatment compared to only 30% cell death achieved with magnetothermia at clinically relevant settings for each at their best performing concentration. Altogether, these results suggest that the biocompatible and superparamagnetic zinc ferrite NPs could be a next biomaterial of choice for photo-hyperthermia, which could outperform current iron oxide NPs for magnetic hyperthermia

Recent insights in magnetic hyperthermia: From the “hot-spot” effect for local delivery to combined magneto-photo-thermia using magneto-plasmonic hybrids

International audienceMagnetic hyperthermia which exploits the heat generated by magnetic nanoparticles (MNPs) when exposed to an alternative magnetic field (AMF) is now in clinical trials for the treatment of cancers. However, this thermal therapy requires a high amount of MNPs in the tumor to be efficient. On the contrary the hot spot local effect refers to the use of specific temperature profile at the vicinity of nanoparticles for heating with minor to no long-range effect. This magneto-thermal effect can be exploited as a relevant external stimulus to temporally and spatially trigger drug release.In this review, we focus on recent advances in magnetic hyperthermia. Indirect experimental proofs of the local temperature increase are first discussed leading to a good estimation of the temperature at the surface (from 0.5 to 6 nm) of superparamagnetic NPs. Then we highlight recent studies illustrating the hot-spot effect for drug- release. Finally, we present another recent strategy to enhance the efficacity of thermal treatment by combining photothermal therapy with magnetic hyperthermia mediated by magneto-plasmonic nanoplatforms

High-Resolution 1.5-Tesla Magnetic Resonance Imaging for Tissue-Engineered Constructs: A Noninvasive Tool to Assess Three-Dimensional Scaffold Architecture and Cell Seeding

International audienceTissue-engineered scaffolds are made of biocompatible polymers with various structures, allowing cell seeding, growth, and differentiation. Noninvasive imaging methods are needed to study tissue-engineered constructs before and after implantation. Here, we show that high-resolution magnetic resonance imaging (MRI) performed on a clinical 1.5-T device is a reliable technique to assess three-dimensional structures of porous scaffolds and to validate cell-seeding procedures. A high-temperature superconducting detection coil was used to achieve a resolution of 30Â30Â30 mm 3 when imaging the scaffolds. Three types of structures with tuneable architectures were prepared from naturally derived polysaccharides and evaluated as scaffolds for mesenchymal stem cell (MSC) culture. To monitor cell seeding, MSCs were magnetically labeled using simple incubation with anionic citrate-coated iron-oxide nanoparticles for 30 min. Iron uptake was quantified using single-cell magnetophoresis, and cell proliferation was checked for 7 days after labeling. Three-dimensional (3D) microstructures of scaffolds were assessed using MRI, revealing lamellar or globular porous organization according to the scaffold preparation process. MSCs with different iron load (5, 12 and 31 pg of iron per cell) were seeded on scaffolds at low density (132 cells=mm 3) and detected on 3D gradient-echo MR images according to phase distortions and areas of intensely low signal, whose size increased with cell iron load and echo time. Overall signal loss in the scaffold correlated with the number of seeded cells and their iron load. Different organizations of cells were observed depending on the scaffold architecture. After subcutaneous implantation in mice, scaffolds seeded with labeled cells could be distinguished in vivo from scaffold with nonlabeled cells by observation of signal and phase heterogeneities and by measuring the global signal loss. High-resolution 1.5-T MRI combined with efficient intracellular contrast agents shows promise for noninvasive 3D visualization of tissue-engineered constructs before and after in vivo implantation

Role of the urinary concentrating process in the renal effects of high protein intake

Role of the urinary concentrating process in the renal effects of high protein intake. High protein diet is known to increase glomerular filtration rate (GFR) and induce kidney hypertrophy. The mechanisms underlying these changes are not understood. Since the mammalian kidney comprises different nephron segments located in well-delineated zones, it is conceivable that the hypertrophy does not affect all kidney zones and all nephron segments uniformly. The present experiments were designed to study the chronic effects of high or low isocaloric protein diets (HP = 32% or LP = 10% casein, respectively) on kidney function and morphology in Sprague-Dawley rats. HP diet induced significant increases in kidney mass, GFR, free water clearance, and maximum urine concentrating ability. Kidney hypertrophy was characterized by: 1. a preferential increase in thickness of the inner stripe of the outer medulla (IS) (+ 54%, P < 0.001, while total kidney height, from cortex to papillary tip, increased only by 18%); 2. a marked hypertrophy of the thick ascending limbs (TAL) in the inner stripe (+40% epithelium volume/unit tubular length, P < 0.05) but not in the outer stripe nor in the cortex; 3. an increase in heterogeneity of glomeruli between superficial (S) and deep (D) nephrons (D/S = 1.47 in HP vs. 1.17 in LP, P < 0.05). In contrast, normal kidney growth with age and kidney hypertrophy induced by uninephrectomy were not accompanied by preferential enlargement of IS structures. The morphologic changes induced by high protein intake parallel those we previously reported in rats fed a normal diet (25% protein) but in which the operation of the urine concentrating mechanism was chronically stimulated by ADH infusion or by reduction in water intake. This similarity and the dramatic increase in free water reabsorption induced by HP diet suggest that high protein intake affects kidney function and morphology by increasing the level of operation of the urine concentrating process. The preferential increase in TAL epithelium disclosed in this study, and the recent demonstration by others of a decreased salt concentration in the early distal tubule of HP rats raises the possibility that the protein-induced increase in GFR is mediated by a depression of tubuloglomerular feedback resulting from an increased salt transport in the medullary TAL in relation with an increase in free water generation