727 research outputs found
A study of redundancy management strategy for tetrad strap-down inertial systems
Algorithms were developed that attempt to identify which sensor in a tetrad configuration has experienced a step failure. An algorithm is also described that provides a measure of the confidence with which the correct identification was made. Experimental results are presented from real-time tests conducted on a three-axis motion facility utilizing an ortho-skew tetrad strapdown inertial sensor package. The effects of prediction errors and of quantization on correct failure identification are discussed as well as an algorithm for detecting second failures through prediction
Iatrogenic nerve injury in primary and revision reverse total shoulder arthroplasty
INTRODUCTION
Iatrogenic nerve injury in orthopedic surgery can impair functional outcomes. During the last years, a steady increase in the number of performed reverse total shoulder arthroplasties has been reported and complications associated with this procedure are continuously described. Neurological complications, however, remain underreported. The aims of this study were to calculate the incidence of iatrogenic nerve injury after primary and revision reverse total shoulder arthroplasty in a large patient cohort, as well as identify associated patient-and surgery-related risk factors.
MATERIALS AND METHODS
A retrospective review of our institution's internal Reverse Total Shoulder Arthroplasty (RTSA) database from September 2005 to December 2019 was undertaken and 34 patients with iatrogenic nerve injuries were identified, resulting in a neurological complication rate of 2.6%. Group comparisons between patients with nerve injuries (n = 34) and the remaining cohort without nerve injuries (n = 1275) were performed to identify patient- and surgery-related risk factors.
RESULTS
Of the 34 cases with iatrogenic nerve injury, damage to terminal nerve branches occurred in 21 patients, whereas a brachial plexus lesion was diagnosed in the other 13. Nerve revision surgery was necessary in four patients. At final follow-up 13 patients (45%) had residual motor deficits and 17 (59%) had residual sensory deficits. Higher numbers of previous surgeries of the affected shoulder correlated with subsequent nerve injury (p = 0.035). Operative time was significantly longer in patients, who developed a neurologic deficit, showing a correlation between duration of surgery and occurrence of nerve injury (p = 0.013). Patients with neurologic complications were significantly younger than patients without nerve damage (median 68 vs. 72 years, p = 0.017).
CONCLUSIONS
In specialists' hands reverse total shoulder arthroplasty is a rather safe procedure regarding the risk of neurologic injury. However, multiple previous surgeries of the affected shoulder increase the risk of neurological complications. Cases with post-operative neurologic compromise are rare and usually recover well, with few patients suffering long-term functional deficits from iatrogenic nerve injury.
LEVEL OF EVIDENCE
Level III, retrospective cohort study
Emerging approaches in the molecular design of receptor-selective peptide ligands: conformational, topographical and dynamic considerations
MODELLING OF COLLECTIVE MOVEMENT IN IMMERSIVE ENVIRONMENTS
Immersive technologies allow us to map physical reality by means of 4D virtual systems in ever higher spatial and temporal detail, up to a scale level of 1 : 1. This level of detail enables the representation of phenomena that have been widely ignored by the geovisualization research agenda as yet. An example for such a large scale phenomenon is the collective movement of animals, which can be modelled and visualized only at a fine grained spatio-temporal resolution. This paper focuses on how collective movement can be modelled in an immersive virtual reality (VR) geovisualization. In a brief introduction on immersion and spatial presence we will argue, that high fidelity and realistic VR can strengthen the users’ involvement with the issues visualized. We will then discuss basic characteristics of swarming in nature and review the principal models that have been presented to formalize this collective behavior. Based on the rules of (1) collision avoidance, (2) polarization, (3) aggregation and (4) self-organized criticality we will formulate a viable solution of modelling collective movement within a geovisualization immersive virtual environment. An example of use and results will be presented
Homogeneous Bubble Nucleation driven by local hot spots: a Molecular Dynamics Study
We report a Molecular Dynamics study of homogenous bubble nucleation in a
Lennard-Jones fluid. The rate of bubble nucleation is estimated using
forward-flux sampling (FFS). We find that cavitation starts with compact
bubbles rather than with ramified structures as had been suggested by Shen and
Debenedetti (J. Chem. Phys. 111:3581, 1999). Our estimate of the
bubble-nucleation rate is higher than predicted on the basis of Classical
Nucleation Theory (CNT). Our simulations show that local temperature
fluctuations correlate strongly with subsequent bubble formation - this
mechanism is not taken into account in CNT
Studies in vitro with ICI 174, 864, [D-Pen2, D-Pen5]-enkephalin (DPDPE) and [D-Ala2, NMePhe4, Gly-ol]-enkephalin (DAGO)
The interactions of a proposed, selective delta receptor antagonist (ICI 174, 864) and selective agonists at mu and delta receptors, [D-Ala2, NMePhe4, Gly-ol]-enkephalin (DAGO) and [D-Pen2, D-Pen5]-enkephalin (DPDPE), respectively, have been studied using the electrically-stimulated mouse isolated vas deferens (MVD) and the guinea-pig isolated ileum (GPI). Incubation of increasing concentrations of ICI 174, 864 (10, 30, 100 and 300 nM) produced a dose-related and parallel rightward displacement of the DPDPE dose-response curve in the MVD. In contrast, ICI 174, 864 (300-3000 nM) failed to affect the DAGO dose-response curve in the same tissue. Analysis of the DPDPE-ICI 174, 864 interaction in the MVD using the pA2 method revealed a Schild plot slope of -0.68 suggesting the involvement of more than one population of receptors. ICI 174, 864 (300 nM) failed to antagonize DPDPE in the GPI at doses up to 30 uM. These results suggest that (a) ICI 174, 864 acts as a selective delta antagonist in the MVD; (b) DPDPE interacts with mu receptors in the MVD but only at very high concentrations, and (c) delta receptors appear not to be of functional importance in the GPI.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25769/1/0000330.pd
Characterization of SNF 9007, A Novel Cholecystokinin/Opoid Ligand in Mouse Ileum in Vitro: Evidence for Involvement of CholecystokininA and CholecystokininB Receptors in Regulation of Ion Transport1
ABSTRACT The effects of cholecystokinin (CCK) fragments and Asp-Tyr-DPh Gly-Trp-[N-Me]Nle-Asp-Phe-NH
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Dairy consumption and cardiometabolic diseases: systematic review and updated meta-analyses of prospective cohort studies
Purpose of Review Dairy products contain both beneficial and harmful nutrients in relation to cardiometabolic diseases. Here, we
provide the latest scientific evidence regarding the relationship between dairy products and cardiometabolic diseases by
reviewing the literature and updating meta-analyses of observational studies.
Recent Findings We updated our previous meta-analyses of cohort studies on type 2 diabetes, coronary heart disease (CHD), and
stroke with nine studies and confirmed previous results. Total dairy and low-fat dairy (per 200 g/d) were inversely associated with
a 3–4% lower risk of diabetes. Yogurt was non-linearly inversely associatedwith diabetes (RR = 0.86, 95%CI: 0.83–0.90 at 80 g/
d). Total dairy and milk were not associated with CHD (RR~1.0). An increment of 200 g of daily milk intake was associated with
an 8% lower risk of stroke.
Summary The latest scientific evidence confirmed neutral or beneficial associations between dairy products and risk of cardiometabolic
diseases
The death and the resurrection of (psy)critique: the case of neuroeducation
A rapidly emerging hegemonic neuro-culture and a booming neural subjectivity signal the entry point for an inquiry into the status of the signifier neuro as a universal passe-partout. The wager of this paper is that the various (mis)appropriations of the neurosciences in the media and in academia itself point to something essential, if not structural, in connection with both the discipline of the neurosciences and the current socio-cultural and ideological climate. Starting from the case of neuroeducation (the application of neuroscience within education), the genealogy of the neurological turn is linked to the history of psychology and its inextricable bond with processes of psychologisation. If the neurological turn risks not merely neglecting the dimension of critique, but also obviating its possibility, then revivifying a psy-critique (understanding the academified modern subject as grounded in the scientific point of view from nowhere) might be necessary in order to understand today’s neural subjectivity and its place within current biopolitics
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