216 research outputs found
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Heterotopic Ossification following Suprapatellar Intramedullary Nailing.
Introduction: Tibial shaft fractures are common fractures seen in trauma and orthopedic practice today. The majority of these fractures are treated with intramedullary nailing (IMN) which is rapidly becoming a gold standard. The procedure itself is performed by either a suprapatellar approach or infrapatellar approach. Suprapatellar approach is gaining popularity due to relative ease of insertion, decreased associated risk of anterior knee pain, and more accurate reduction. We report a case of heterotopic ossification noted in the knee following IMN of tibia performed using a suprapatellar approach. Case Report: A 27-year-old male, having sustained a left, Gustilo IIIB tibial shaft fracture following a motor vehicle accident, underwent a reamed intramedullary nail fixation performed through a suprapatellar approach. Two months later, he presented with intra-articular heterotopic ossification which was limiting his knee movement. He then underwent arthroscopic removal of the bony fragments which resolved his symptoms. Conclusion: An extensive search of literature did not yield any reported incidence of heterotopic ossification associated with IMN performed through a suprapatellar approach. We present this case report to raise awareness that although IMN through a suprapatellar approach is a safe approach, it does have associated risk of heterotopic ossification which needs to be included in the consent process
Harmonic oscillations and their switching in elliptical optical waveguide arrays
We have studied harmonic oscillations in an elliptical optical waveguide
array in which the coupling between neighboring waveguides is varied in accord
with a Kac matrix so that the propagation constant eigenvalues can take equally
spaced values. As a result, long-living Bloch oscillation (BO) and dipole
oscillation (DO) are obtained when a linear gradient in the propagation
constant is applied. Moreover, we achieve a switching from DO to BO or vice
versa by ramping up the gradient profile. The various optical oscillations as
well as their switching are investigated by field evolution analysis and
confirmed by Hamiltonian optics. The equally spaced eigenvalues in the
propagation constant allow viable applications in transmitting images,
switching and routing of optical signals.Comment: 14 pages, 5 figure
The Association Between Adverse Childhood Experiences (ACEs), Bullying Victimization, and Internalizing and Externalizing Problems Among Early Adolescents: Examining Cumulative and Interactive Associations
Both adverse childhood experiences (ACEs) and bullying victimization are linked with mental health problems in adolescents. However, little is known about the overlap between the two factors and how this impacts adolescent mental health problems (i.e., internalizing and externalizing problems). The current study analyzed data from 8,085 participants (47.7% female; 44.1% racial/ethnic minority) in the Adolescent Brain Cognitive Development (ABCD) study, baseline (2016–2018, ages 9–10 years) to Year 2. Regression analyses were used to estimate associations between ACEs, bullying victimization and mental health problems, respectively, adjusting for sex, race/ethnicity, country of birth, household income, parental education, and study site. The findings showed that both ACEs and bullying victimization were independently associated with higher internalizing and higher externalizing problems. However, no significant interaction was found between ACEs and bullying victimization. Overall, the results align with the cumulative risk model of adversity, linking cumulative ACEs and bullying victimization to internalizing and externalizing problems in early adolescents
The treatment of segmental tibial fractures: does patient preference differ from surgeon choice?
INTRODUCTION: Segmental tibial fractures are complex injuries with a prolonged recovery time. Current definitive treatment options include intramedullary fixation or a circular external fixator. However, there is uncertainty as to which surgical option is preferable and there are no sufficiently rigorous multi-centre trials that have answered this question. The objective of this study was to determine whether patient and surgeon opinion was permissive for a randomised controlled trial (RCT) comparing intramedullary nailing to the application of a circular external fixator. MATERIALS AND METHODS: A convenience questionnaire survey of attending surgeons was conducted during the United Kingdom's Orthopaedic Trauma Society annual meeting 2017 to determine the treatment modalities used for a segmental tibial fracture (n=63). Patient opinion was obtained from clinical patients who had been treated for a segmental tibial fracture as part of a patient and public involvement focus group with questions covering the domains of surgical preference, treatment expectations, outcome, the consent process and follow-up regime (n=5). RESULTS: Based on the surgeon survey, 39% routinely use circular frame fixation following segmental tibial fracture compared to 61% who use nail fixation. Nail fixation was reported as the treatment of choice for a closed injury in a healthy patient in 81% of surgeons, and by 86% for a patient with a closed fracture who was obese. Twenty-one percent reported that they would use a nail for an open segmental tibia fracture in diabetics who smoked, whilst 57% would opt for a nail for a closed injury with compartment syndrome, and only 27% would use a nail for an open segmental injury in a young fit sports person. The patient and public preference exercise identified that sleep, early functional outcomes and psychosocial measures of outcomes are important. CONCLUSION: We concluded that a RCT comparing definitive fixation with an intramedullary nail and a circular external fixator is justified as there remains uncertainty on the optimal surgical management for segmental tibial fractures. Furthermore, psychosocial factors and early post-operative outcomes should be reported as core outcome measures as part of such a trial
Solitons in one-dimensional nonlinear Schr\"{o}dinger lattices with a local inhomogeneity
In this paper we analyze the existence, stability, dynamical formation and
mobility properties of localized solutions in a one-dimensional system
described by the discrete nonlinear Schr\"{o}dinger equation with a linear
point defect. We consider both attractive and repulsive defects in a focusing
lattice. Among our main findings are: a) the destabilization of the on--site
mode centered at the defect in the repulsive case; b) the disappearance of
localized modes in the vicinity of the defect due to saddle-node bifurcations
for sufficiently strong defects of either type; c) the decrease of the
amplitude formation threshold for attractive and its increase for repulsive
defects; and d) the detailed elucidation as a function of initial speed and
defect strength of the different regimes (trapping, trapping and reflection,
pure reflection and pure transmission) of interaction of a moving localized
mode with the defect.Comment: 12 pages, 10 figure
Schrodinger cat states prepared by Bloch oscillation in a spin-dependent optical lattice
We propose to use Bloch oscillation of ultra-cold atoms in a spin-dependent
optical lattice to prepare schrodinger cat states. Depending on its internal
state, an atom feels different periodic potentials and thus has different
energy band structures for its center-of-mass motion. Consequently, under the
same gravity force, the wave packets associated with different internal states
perform Bloch oscillation of different amplitudes in space and in particular
they can be macroscopically displaced with respect to each other. In this way,
a cat state can be prepared.Comment: 4 pages, 3 figures; slightly modifie
Impact of Excess Auditor Remuneration on the Cost of Equity Capital around the World
This study examines the relation between excess auditor remuneration and the implied required rate of return (IRR hereafter) on equity capital in global markets. We conjecture that when auditor remuneration is excessively large, investors may perceive the auditor to be economically bonded to the client, leading to a lack of independence. This perceived lack of independence increases the information risk associated with the credibility of financial statements, thereby increasing IRR. Consistent with this notion, we find that IRR is increasing in excess auditor remuneration, but only in countries with stronger investor protection. Finding evidence of a relation only in stronger investor protection countries is consistent with the more prominent role of audited financial statements for investors' decisions in these countries. In settings in which investors are less likely to rely on audited financial statements and instead rely on alternative sources of information (i.e., in countries with weaker investor protection), the impact of client-auditor bonding should have less of an effect on investors' decisions.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Study of montelukast in children with sickle cell disease (SMILES): a study protocol for a randomised controlled trial
BACKGROUND: Young children with sickle cell anaemia (SCA) often have slowed processing speed associated with reduced brain white matter integrity, low oxygen saturation, and sleep-disordered breathing (SDB), related in part to enlarged adenoids and tonsils. Common treatments for SDB include adenotonsillectomy and nocturnal continuous positive airway pressure (CPAP), but adenotonsillectomy is an invasive surgical procedure, and CPAP is rarely well-tolerated. Further, there is no current consensus on the ability of these treatments to improve cognitive function. Several double-blind, randomised controlled trials (RCTs) have demonstrated the efficacy of montelukast, a safe, well-tolerated anti-inflammatory agent, as a treatment for airway obstruction and reducing adenoid size for children who do not have SCA. However, we do not yet know whether montelukast reduces adenoid size and improves cognition function in young children with SCA. METHODS: The Study of Montelukast In Children with Sickle Cell Disease (SMILES) is a 12-week multicentre, double-blind, RCT. SMILES aims to recruit 200 paediatric patients with SCA and SDB aged 3-7.99 years to assess the extent to which montelukast can improve cognitive function (i.e. processing speed) and sleep and reduce adenoidal size and white matter damage compared to placebo. Patients will be randomised to either montelukast or placebo for 12 weeks. The primary objective of the SMILES trial is to assess the effect of montelukast on processing speed in young children with SCA. At baseline and post-treatment, we will administer a cognitive evaluation; caregivers will complete questionnaires (e.g. sleep, pain) and measures of demographics. Laboratory values will be obtained from medical records collected as part of standard care. If a family agrees, patients will undergo brain MRIs for adenoid size and other structural and haemodynamic quantitative measures at baseline and post-treatment, and we will obtain overnight oximetry. DISCUSSION: Findings from this study will increase our understanding of whether montelukast is an effective treatment for young children with SCA. Using cognitive testing and MRI, the SMILES trial hopes to gain critical knowledge to help develop targeted interventions to improve the outcomes of young children with SCA. TRIAL REGISTRATION: ClinicalTrials.gov NCT04351698 . Registered on April 17, 2020. European Clinical Trials Database (EudraCT No. 2017-004539-36). Registered on May 19, 2020
Reference values for serum creatinine in children younger than 1 year of age
Reliable reference values of enzymatically assayed serum creatinine categorized in small age intervals are lacking in young children. The aim of this study was to determine reference values for serum creatinine during the first year of life and study the influence of gender, weight and height on these values. Serum creatinine determinations between 2003 and 2008 were retrieved from the hospital database. Strict exclusion criteria ensured the selection of patients without kidney damage. Correlation analysis was performed to evaluate the relation between height, weight and serum creatinine; the Mann–Whitney test was used to evaluate the relation between gender and serum creatinine. A broken stick model was designed to predict normal serum creatinine values. Mean serum creatinine values were found to decrease rapidly from 55 μmol/L on day 1 to 22 μmol/L in the second month of life; they then stabilized at 20 μmol/L until the seventh month, followed by a slight increase. No significant relation was found between serum creatinine and gender, weight and height. We present here reference values of serum creatinine in infants not at risk of decreased renal function. The absence of a relationship with gender, weight and height confirms that height-based equations to estimate glomerular filtration rate are less useful in patients of this age group
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