871 research outputs found

    Changes in landing mechanics in patients following anterior cruciate ligament reconstruction when wearing an extension constraint knee brace.

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    BACKGROUND: Anterior cruciate ligament (ACL) reconstruction is associated with a high incidence of second tears (graft tears and contralateral ACL tears). These secondary tears have been attributed to asymmetrical lower extremity mechanics. Knee bracing is one potential intervention that can be used during rehabilitation that has the potential to normalize lower extremity asymmetry; however, little is known about the effect of bracing on movement asymmetry in patients following ACL reconstruction. HYPOTHESIS: Wearing a knee brace would increase knee joint flexion and joint symmetry. It was also expected that the joint mechanics would become more symmetrical in the braced condition. OBJECTIVE: To examine how knee bracing affects knee joint function and symmetry over the course of rehabilitation in patients 6 months following ACL reconstruction. STUDY DESIGN: Controlled laboratory study. LEVEL OF EVIDENCE: Level 3. METHODS: Twenty-three adolescent patients rehabilitating from ACL reconstruction surgery were recruited for the study. The subjects all underwent a motion analysis assessment during a stop-jump activity with and without a functional knee brace on the surgical side that resisted extension for 6 months following the ACL reconstruction surgery. Statistical analysis utilized a 2 × 2 (limb × brace) analysis of variance with a significant alpha level of 0.05. RESULTS: Subjects had increased knee flexion on the surgical side when they were braced. The brace condition increased knee flexion velocity, decreased the initial knee flexion angle, and increased the ground reaction force and knee extension moment on both limbs. Side-to-side asymmetry was present across conditions for the vertical ground reaction force and knee extension moment. CONCLUSION: Wearing a knee brace appears to increase lower extremity compliance and promotes normalized loading on the surgical side. CLINICAL RELEVANCE: Knee extension constraint bracing in postoperative ACL patients may improve symmetry of lower extremity mechanics, which is potentially beneficial in progressing rehabilitation and reducing the incidence of second ACL tears

    Using ground reaction force to predict knee kinetic asymmetry following anterior cruciate ligament reconstruction.

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    Asymmetries in sagittal plane knee kinetics have been identified as a risk factor for anterior cruciate ligament (ACL) re-injury. Clinical tools are needed to identify the asymmetries. This study examined the relationships between knee kinetic asymmetries and ground reaction force (GRF) asymmetries during athletic tasks in adolescent patients following ACL reconstruction (ACL-R). Kinematic and GRF data were collected during a stop-jump task and a side-cutting task for 23 patients. Asymmetry indices between the surgical and non-surgical limbs were calculated for GRF and knee kinetic variables. For the stop-jump task, knee kinetics asymmetry indices were correlated with all GRF asymmetry indices (P < 0.05), except for loading rate. Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2)  ≥ 0.78, P < 0.01) asymmetry indices. For the side-cutting tasks, knee kinetic asymmetry indices were correlated with the peak propulsion vertical GRF and vertical GRF impulse asymmetry indices (P < 0.05). Vertical GRF impulse asymmetry index predicted peak knee moment, average knee moment, and knee work (R(2)  ≥ 0.55, P < 0.01) asymmetry indices. The vertical GRF asymmetries may be a viable surrogate for knee kinetic asymmetries and therefore may assist in optimizing rehabilitation outcomes and minimizing re-injury rates

    Needle aspiration as therapeutic management for suppurative cervical lymphadenitis in children

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    PurposeThis study aimed to evaluate the usefulness of the needle aspiration alternative to open surgical drainage of children with suppurative cervical lymphadenitis requiring surgical drainage.MethodsFrom January 1998 to June 2008, we retrospectively reviewed 38 children treated with needle aspiration as management with suppurative cervical lymphadenitis instead of open surgical drainage.ResultsAll 38 children underwent only 1 puncture. Two patients (5.2%) out of 38 patients experienced reformation of an abscess and all recovered completely after re-treatment with antibiotics. Minor complications were detected in 2 patients (5.2%). One complication originated from remnant necrotic tissue and the other involved formation of a small scar in two patients, which resolved spontaneously. There were no major complications.ConclusionNeedle aspiration can be a simple, safe, and effective alternative procedure to open surgical drainage of children with suppurative cervical lymphadenitis requiring surgical drainage

    On identifiability for chemical systems from measurable variables

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    The final publication is available at Springer via http://dx.doi.org/10.1007/s10910-013-0149-4The dynamics of the composition of chemical species in reacting systems can be characterized by a set of autonomous differential equations derived from mass conservation principles and some elementary hypothesis related to chemical reactivity. These sets of ordinary differential equations are basically non-linear, their complexity grows as much increases the number of substances present in the reacting media an can be characterized by a set of phenomenological constants which contains all the relevant information about the physical system. The determination of these kinetic constants is critical for the design or control of chemical systems from a technological point of view but the non-linear nature of the equations implies that there are hidden correlations between the parameters which maybe can be revealed with a identifiability analysis.This work has been partially supported by MTM2010-18228.Cantó Colomina, B.; Coll, C.; Sánchez, E.; Cardona Navarrete, SC.; Navarro-Laboulais, J. (2014). On identifiability for chemical systems from measurable variables. Journal of Mathematical Chemistry. 52(4):1023-1035. https://doi.org/10.1007/s10910-013-0149-4S10231035524M.J. Almendral, A. Alonso, M.S. Fuentes, Development of new methodologies for on-line determination of the bromate. J. Environ. Monit. 11, 1381–1388 (2009)A. Ben-Zvi, P.J. McLellan, K.B. McAuley, Identifiability of linear time-invariant differential-algebraic systems. I. The generalized Markov parameter approach. Ind. Eng. Chem. Res. 42, 6607–6618 (2003)T.P. Bonacquisti, A drinking water utility’s perspective on bromide, bromate, and ozonation. Toxicology 221, 145–148 (2006)R. Butler, A. Godley, L. Lytton, E. Cartmell, Bromate environmental contamination: review of impact and possible treatment. Crit. Rev. Environ. Sci. Tech. 35, 193–217 (2005)R. Butler, L. Lytton, A.R. Godley, I.E. Tothill, E. Cartmell, Bromate analysis in groundwater and wastewater samples. J. Environ. Monit. 7, 999–1006 (2005)B. Cantó, S.C. Cardona, C. Coll, J. Navarro-Laboulais, E. Sánchez, Dynamic optimization of a gas-liquid reactor. J. Math. Chem. 50, 381–393 (2012)B. Cantó, C. Coll and E. Sánchez, Identifiability of a class of discretized linear partial differential algebraic equations, Math. Problems Eng. 2011, 1–12 (2011)A. Constantinides, N. Mostoufi, Numerical Methods for Chemical Engineers with MATLAB Applications, Alkis Constantinides and Navid Mostoufi, Upper Saddle River (Prentice Hall, New Jersey, 1999)P. Englezos, N. Kalogerakis, Applied Parameter Estimation for Chemical Engineers (Marcel Dekker, New York, 2001)U. von Gunten, Ozonation of drinking water. Part II. Disinfection and by-product formation in presence of bromide, iodide or chlorine. Water Res. 37, 1469–1487 (2003)B. Legube, B. Parinet, K. Gelinet, F. Berne, J-Ph Croue, Modeling of bromate formation by ozonation of surface waters in drinking water treatment. Water Res. 38, 2185–2195 (2004)Q. Liu, L.M. Schurter, C.E. Muller, S. Aloisio, J.S. Francisco, D.W. Margerum, Kinetics and mechanisms of aqueous ozone reactions with bromide, sulfite, hydrogen sulfite, iodide, and nitrite ions. Inorg. Chem. 40, 4436–4442 (2001)J.B. Rawling, J.G. Ekerdt, Chemical Reactor Analysis and Design Fundamentals (Nob Hill Pub, Madison, 2002)W.E. Stewart, M. Caracotsios, Computer Aided Modelling of Reactive Systems (John Wiley and Sons, New York, 2008)P. Westerhoff, R. Song, G. Amy, R. Minear, Numerical kinetic models for bromide oxidation to bromine and bromate. Water Res. 32, 1687–1699 (1998)World Health Organization, Bromate in Drinking-water, Document WHO/SDE/WSH/05.08/78, http://www.who.int/water_sanitation_health/dwq/chemicals/en/ (accesed 26/07/12

    Initial experience with off-pump left ventricular assist device implantation in single center: retrospective analysis

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    <p>Abstract</p> <p>Background</p> <p>We hypothesize that implantation of left ventricular assist device through off-pump technique is feasible and has a comparable result to implantation on cardiopulmonary bypass and could improve one-year survival.</p> <p>Methods</p> <p>This retrospective, observational, single-center study was conducted on 29 consecutive patients at our institution who underwent off-pump left ventricular assist device implantation by a single surgeon.</p> <p>Results</p> <p>Twenty-seven procedures were performed successfully using the off-pump technique. The survival rate was 92% at 30 days, 76% at 90 days, and 67% at one year. We compared the one-year survival of different implantation periods, and divided our study into three time intervals (2004-2005, 2006, and 2007). There was a trend in reduction in number of deaths over one year that demonstrated a decrease in death rate from 50% to 17%, as well as improvement in our experience over time. However, this trend is not statistically significant (p = 0.08) due to limited sample size.</p> <p>Conclusions</p> <p>Based upon our findings, off-pump left ventricular assist device implantation is a feasible surgical technique, and combining this technique with improved device technology in the future may provide even greater improvement in patient outcomes.</p

    Abdominal functional electrical stimulation to improve respiratory function after spinal cord injury: a systematic review and meta-analysis

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    Objectives: Abdominal functional electrical stimulation (abdominal FES) is the application of a train of electrical pulses to the abdominal muscles, causing them to contract. Abdominal FES has been used as a neuroprosthesis to acutely augment respiratory function and as a rehabilitation tool to achieve a chronic increase in respiratory function after abdominal FES training, primarily focusing on patients with spinal cord injury (SCI). This study aimed to review the evidence surrounding the use of abdominal FES to improve respiratory function in both an acute and chronic manner after SCI. Settings: A systematic search was performed on PubMed, with studies included if they applied abdominal FES to improve respiratory function in patients with SCI. Methods: Fourteen studies met the inclusion criteria (10 acute and 4 chronic). Low participant numbers and heterogeneity across studies reduced the power of the meta-analysis. Despite this, abdominal FES was found to cause a significant acute improvement in cough peak flow, whereas forced exhaled volume in 1 s approached significance. A significant chronic increase in unassisted vital capacity, forced vital capacity and peak expiratory flow was found after abdominal FES training compared with baseline. Conclusions: This systematic review suggests that abdominal FES is an effective technique for improving respiratory function in both an acute and chronic manner after SCI. However, further randomised controlled trials, with larger participant numbers and standardised protocols, are needed to fully establish the clinical efficacy of this technique

    Reviewing, indicating, and counting books for modern research evaluation systems

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    In this chapter, we focus on the specialists who have helped to improve the conditions for book assessments in research evaluation exercises, with empirically based data and insights supporting their greater integration. Our review highlights the research carried out by four types of expert communities, referred to as the monitors, the subject classifiers, the indexers and the indicator constructionists. Many challenges lie ahead for scholars affiliated with these communities, particularly the latter three. By acknowledging their unique, yet interrelated roles, we show where the greatest potential is for both quantitative and qualitative indicator advancements in book-inclusive evaluation systems.Comment: Forthcoming in Glanzel, W., Moed, H.F., Schmoch U., Thelwall, M. (2018). Springer Handbook of Science and Technology Indicators. Springer Some corrections made in subsection 'Publisher prestige or quality

    Spatially organizing future genders: an artistic intervention in the creation of a hir-toilet

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    Toilets, a neglected facility in the study of human relations at work and beyond, have become increasingly important in discussions about future experiences of gender diversity. To further investigate the spatial production of gender and its potential expressions, we transformed a unisex single-occupancy toilet at Uppsala University into an all-gender or ‘hir-toilet’.1 With the aim to disrupt and expose the dominant spatial organization of the two binary genders, we inaugurated the hir-toilet with the help of a performance artist. We describe and analyse internal and external responses thereto, using Lefebvre’s work on dialectics and space. Focusing on how space is variously lived, conceived and perceived, our analysis questions the very rationale of gender categorizations. The results contribute to a renewed critique of binary thinking in the organization of workplaces by extending our understanding of how space and human relations mutually constitute each other

    Differential Effects of Early- and Late-Life Access to Carotenoids on Adult Immune Function and Ornamentation in Mallard Ducks (Anas platyrhynchos)

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    Environmental conditions early in life can affect an organism’s phenotype at adulthood, which may be tuned to perform optimally in conditions that mimic those experienced during development (Environmental Matching hypothesis), or may be generally superior when conditions during development were of higher quality (Silver Spoon hypothesis). Here, we tested these hypotheses by examining how diet during development interacted with diet during adulthood to affect adult sexually selected ornamentation and immune function in male mallard ducks (Anas platyrhynchos). Mallards have yellow, carotenoid-pigmented beaks that are used in mate choice, and the degree of beak coloration has been linked to adult immune function. Using a 2×2 factorial experimental design, we reared mallards on diets containing either low or high levels of carotenoids (nutrients that cannot be synthesized de novo) throughout the period of growth, and then provided adults with one of these two diets while simultaneously quantifying beak coloration and response to a variety of immune challenges. We found that both developmental and adult carotenoid supplementation increased circulating carotenoid levels during dietary treatment, but that birds that received low-carotenoid diets during development maintained relatively higher circulating carotenoid levels during an adult immune challenge. Individuals that received low levels of carotenoids during development had larger phytohemagglutinin (PHA)-induced cutaneous immune responses at adulthood; however, dietary treatment during development and adulthood did not affect antibody response to a novel antigen, nitric oxide production, natural antibody levels, hemolytic capacity of the plasma, or beak coloration. However, beak coloration prior to immune challenges positively predicted PHA response, and strong PHA responses were correlated with losses in carotenoid-pigmented coloration. In sum, we did not find consistent support for either the Environmental Matching or Silver Spoon hypotheses. We then describe a new hypothesis that should be tested in future studies examining developmental plasticity

    Variability in a dominant block to SIV early reverse transcription in rhesus monkey cells predicts in vivo viral replication and time to death

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    While it has long been appreciated that there is considerable variability in host containment of HIV/SIV replication, the determinants of that variability are not fully understood. Previous studies demonstrated that the degree of permissivity of a macaque's peripheral blood mononuclear cells (PBMC) for infection with simian immunodeficiency virus (SIV) in vitro predicted that animal's peak plasma virus RNA levels following SIV infection in vivo. The present study was conducted to define the mechanisms underlying the variable intrinsic susceptibility of rhesus monkey PBMC to SIVsmE660 infection. In a cohort of 15 unrelated Indian-origin rhesus monkeys, infectability of PBMC of individual animals with SIVsmE660, as defined by tissue culture infectious dose (TCID50), varied by more than 3 logs and was a stable phenotype over time. Susceptibility of a monkey's PBMC to wild type SIVsmE660 infection correlated with the susceptibility of that monkey's PBMC to infection with VSV-G pseudotyped SIVsm543-GFP. Moreover, the permissivity of an individual monkey's PBMC for infection with this construct correlated with the permissivity of a B-lymphoblastoid cell line (B-LCL) generated from PBMC of the same animal. We found that the degree of intrinsic resistance of monkey B-LCL correlated with the copy number of early reverse transcription (ERT) SIV DNA. The resistance of monkey B-LCL to SIVsmE660 replication could be abrogated by preincubation of cells with the SIV virus-like particles (VLPs) and SIV resistance phenotype could be transferred to a SIV susceptible B-LCL through cell fusion. Finally, we observed a positive correlation between susceptibility of monkey B-LCL to SIV infection with a VSV-G pseudotyped SIV-GFP construct in vitro and both the peak plasma virus RNA levels in vivo and time to death following wild type SIV infection. These findings suggest that a dominant early RT restricting factor that can be saturated by SIV capsid may contribute to the variable resistance to SIV infection in rhesus monkey B-LCL and that this differential intrinsic susceptibility contributes to the clinical outcome of an SIV infection
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