194 research outputs found
A formulation of the fractional Noether-type theorem for multidimensional Lagrangians
This paper presents the Euler-Lagrange equations for fractional variational
problems with multiple integrals. The fractional Noether-type theorem for
conservative and nonconservative generalized physical systems is proved. Our
approach uses well-known notion of the Riemann-Liouville fractional derivative.Comment: Submitted 26-SEP-2011; accepted 3-MAR-2012; for publication in
Applied Mathematics Letter
The use of nasal midazolam in reducing preoperative anxiety in children
Background: Surgery and anesthesia can cause a considerable distress with psychological consequences for children. This preoperative anxiety can lead to post operative emergence delirium, maladaptive behavioral changes such as night time crying, enuresis, feeding difficulties, apathy, and withdrawal.Objectives: The aim of this study is to investigate the effect of nasal midazolam as a routine intervention to reduce pre-operative anxiety and inducing anxiolysis in children undergoing day case procedure.Method: One hundred children were randomly allocated into two groups. The study group (N=50) were premedicated with nasal midazolam 0.2mg/kg and the control group (N=50) who received 0.04ml of normal saline. The children response to nasal administration was noticed and after 15 minutes children were taken to operating room. Anxiety at parental separation and at induction of anesthesia was measured using modified-Yale Preoperative Anxiety Scale.Results: Children who received nasal midazolam had a significantly better parental separation and induction of anesthesia. 88% of children who received nasal midazolam scored below 30-indicating absence of anxiety- on modified-Yale Preoperative Anxiety Scale compared to 32% in the control group. More than half of patients in both groups found nasal route to be unpleasant and stressful.Conclusion: For children undergoing elective brief surgical procedure, nasal midazolam is effective in reducing preoperative anxiety. Nasal midazolam was associated in more than half of patients with nasal irritation and crying, a route can not be recommended in children
Laparoscopy for the management of impalpable testis
Background: Cryptorchidism is encountered in 21% of preterm infants, 2-4% of all full term boys and 1% of one year old boys.Objectives:To present our experience in the utilization of diagnostic laparoscopy for the management of children with impalpable testes.Method:This is a retrospective study conducted between March 2010 and December 2011. The medical records of boys with impalpable testis were reviewed. Diagnostic laparoscopic findings regarding presence, morphological state, and location of testis were analyzed. Special attention to how initial laparoscopy influenced subsequent surgical procedures and management.Results:Fifty four boys underwent laparoscopy with 76 impalpable testes. Forty testes were unilateral impalpable testes, two third of them were left sided. Thirty seven testes were intraabdominal, eight of them were atrophied and excised laparoscopically. Twenty nine of them were viable, 90% of them underwent first stage Fowler-Stephens procedure, while the rest underwent primary laparoscopic orchidopexy. Vas and spermatic vessels were seen entering inguinal canal in 25 testes. This group had immediate inguinal exploration, 22 of testes underwent orchidopexy and three orchidectomy. Fourteen boys found to blind end vas and vessels with no further treatment needed.Conclusions: Laparoscopic exploration should be performed because it accurately identifies and localizes the missing testis. In addition, it facilitates the planning of definitive surgical management of orchidopexy, staged orchidopexy or orchidectomy. So we recommend that initial laparoscopic exploration should be performed for patient with impalpable testis.Keywords:Impalpable testis, Laparoscopy, Orchidopexy, Jordan
Percutaneous central venous catheterization in children, is it efficient?
ObjectiveTo evaluate the frequent use of percutaneous central venous catheters (CVCs) in pediatric agegroup.MethodsRetrospectively we reviewed the records of all children that had percutaneous CVCs in the pediatric surgical ward and pediatric intensive care unit at King Hussein Medical Center between January2007 and December 2007 (one year). Patients were evaluated with respect to their age, gender, catheter type, indication for CVC insertion, site of CVC insertion. The duration of catheter use and eventual complications were also taken into consideration.ResultsA total of 120 percutaneous CVCs were inserted in 104 children. Patient age ranged from one day to14 years. The average catheter insertion time was 12.5 days. We noted 66 (18.8%) CVC- related complications. Complications related to percutaneous CVCs insertion were malposition of catheter (5.4%) and pneumothorax (0.9%). Occlusion of CVCs (4.3%), catheter related bloodstream infections (CRBI) (4.0%), dislodgment (3.7%) and catheter damage (0.6%) were complications associated with lenght of CVCs use.ConclusionWe conclude that percutaneous central venous catheterization is a safe and efficient procedure that can be done at bedside with minimal complications in pediatric age group.Keywords: Percutaneous, indications, complications, children.
Fractional Euler-Lagrange differential equations via Caputo derivatives
We review some recent results of the fractional variational calculus.
Necessary optimality conditions of Euler-Lagrange type for functionals with a
Lagrangian containing left and right Caputo derivatives are given. Several
problems are considered: with fixed or free boundary conditions, and in
presence of integral constraints that also depend on Caputo derivatives.Comment: This is a preprint of a paper whose final and definite form will
appear as Chapter 9 of the book Fractional Dynamics and Control, D. Baleanu
et al. (eds.), Springer New York, 2012, DOI:10.1007/978-1-4614-0457-6_9, in
pres
Generalized transversality conditions in fractional calculus of variations
Problems of calculus of variations with variable endpoints cannot be solved without transversality conditions. Here, we establish such type of conditions for fractional variational problems with the Caputo derivative. We consider: the Bolza-type fractional variational problem, the fractional variational problem with a Lagrangian that may also depend on the unspecified end-point phi(b), where x = phi(t) is a given curve, and the infinite horizon fractional variational problem. (C) 2012 Elsevier B.V. All rights reserved
Fractional Dynamics from Einstein Gravity, General Solutions, and Black Holes
We study the fractional gravity for spacetimes with non-integer dimensions.
Our constructions are based on a geometric formalism with the fractional Caputo
derivative and integral calculus adapted to nonolonomic distributions. This
allows us to define a fractional spacetime geometry with fundamental
geometric/physical objects and a generalized tensor calculus all being similar
to respective integer dimension constructions. Such models of fractional
gravity mimic the Einstein gravity theory and various Lagrange-Finsler and
Hamilton-Cartan generalizations in nonholonomic variables. The approach
suggests a number of new implications for gravity and matter field theories
with singular, stochastic, kinetic, fractal, memory etc processes. We prove
that the fractional gravitational field equations can be integrated in very
general forms following the anholonomic deformation method for constructing
exact solutions. Finally, we study some examples of fractional black hole
solutions, fractional ellipsoid gravitational configurations and imbedding of
such objects in fractional solitonic backgrounds.Comment: latex2e, 11pt, 40 pages with table of conten
White Matter Microstructure and Structural Networks in Treatment-Resistant Schizophrenia Patients After Commencing Clozapine Treatment: A Longitudinal Diffusion Imaging Study
This study investigates changes on white matter microstructure and neural networks after 6 months of switching to clozapine in schizophrenia patients compared to controls, and whether any changes are related to clinical variables. T1 and diffusion-weighted MRI images were acquired at baseline before commencing clozapine and after 6 months of treatment for 22 patients with treatment-resistant schizophrenia and 23 controls. The Tract-based spatial statistics approach was used to compare changes over time between groups in fractional anisotropy (FA). Changes in structural network organisation weighted by FA and number of streamlines were assessed using graph theory. Patients displayed a significant reduction of FA over time (p<0.05) compared to controls in the genu and body of the corpus callosum and bilaterally in the anterior and superior corona radiata. There was no correlation between FA change in patients and changes in clinical variables or serum level of clozapine. There was no changes in structural network organisation between groups (F(7,280)=2.80;p = 0.187). This longitudinal study demonstrated progressive focal FA abnormalities in key anterior tracts, but preserved brain structural network organisation in patients. The FA reduction was independent of any clinical measures and may reflect progression of the underlying pathophysiology of this malignant form of schizophrenia illness
Equal antipyretic effectiveness of oral and rectal acetaminophen: a randomized controlled trial [ISRCTN11886401]
BACKGROUND: The antipyretic effectiveness of rectal versus oral acetaminophen is not well established. This study is designed to compare the antipyretic effectiveness of two rectal acetaminophen doses (15 mg/kg) and (35 mg/kg), to the standard oral dose of 15 mg/kg. METHODS: This is a randomized, double-dummy, double-blind study of 51 febrile children, receiving one of three regimens of a single acetaminophen dose: 15 mg/kg orally, 15 mg/kg rectally, or 35 mg/kg rectally. Rectal temperature was monitored at baseline and hourly for a total of six hours. The primary outcome of the study, time to maximum antipyresis, and the secondary outcome of time to temperature reduction by at least 1°C were analyzed by one-way ANOVA. Two-way ANOVA with repeated measures over time was used to compare the secondary outcome: change in temperature from baseline at times1, 2, 3, 4, 5, and 6 hours among the three groups. Intent-to-treat analysis was planned. RESULTS: No significant differences were found among the three groups in the time to maximum antipyresis (overall mean = 3.6 hours; 95% CI: 3.2–4.0), time to fever reduction by 1°C or the mean hourly temperature from baseline to 6 hours following dose administration. Hypothermia (temperature < 36.5°C) occurred in 11(21.6%) subjects, with the highest proportion being in the rectal high-dose group. CONCLUSION: Standard (15 mg/kg) oral, (15 mg/kg) rectal, and high-dose (35 mg/kg) rectal acetaminophen have similar antipyretic effectiveness
Normalization of impaired emotion inhibition in bipolar disorder mediated by cholinergic neurotransmission in the cingulate cortex
The muscarinic-cholinergic system is involved in the pathophysiology of bipolar disorder (BD), and contributes to attention and the top-down and bottom-up cognitive and affective mechanisms of emotional processing, functionally altered in BD. Emotion processing can be assessed by the ability to inhibit a response when the content of the image is emotional. Impaired regulatory capacity of cholinergic neurotransmission conferred by reduced M2-autoreceptor availability is hypothesized to play a role in elevated salience of negative emotional distractors in euthymic BD relative to individuals with no history of mood instability. Thirty-three euthymic BD type-I (DSM-V-TR) and 50 psychiatrically-healthy controls underwent functional magnetic resonance imaging (fMRI) and an emotion-inhibition paradigm before and after intravenous cholinergic challenge using the acetylcholinesterase inhibitor, physostigmine (1 mg), or placebo. Mood, accuracy, and reaction time on either recognizing or inhibiting a response associated with an image involving emotion and regional functional activation were examined for effects of cholinergic challenge physostigmine relative to placebo, prioritizing any interaction with the diagnostic group. Analyses revealed that (1) at baseline, impaired behavioral performance was associated with lower activation in the anterior cingulate cortex in BD relative to controls during emotion processing; (2) physostigmine (vs. placebo) affected behavioral performance during the inhibition of negative emotions, without altering mood, and increased activation in the posterior cingulate cortex in BD (vs. controls); (3) In BD, lower accuracy observed during emotion inhibition of negative emotions was remediated by physostigmine and was associated with cingulate cortex overactivation. Our findings implicate abnormal regulation of cholinergic neurotransmission in the cingulate cortices in BD, which may mediate exaggerated emotional salience processing, a core feature of BD
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