170 research outputs found

    Percutaneous central venous catheterization in children, is it efficient?

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    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.

    Effect of vitamin D replacement on maternal and neonatal outcomes: a randomised controlled trial in pregnant women with hypovitaminosis D. A protocol

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    Introduction: The vitamin D recommended doses during pregnancy differ between societies. The WHO guidelines do not recommend routine prenatal supplementation, but they underscore the fact that women with the lowest levels may benefit most. The effects of routine supplementation during pregnancy on maternal and neonatal clinical outcomes have not been investigated in the Middle East, where hypovitaminosis D is prevalent. Our hypothesis is that in Middle Eastern pregnant women, a vitamin D dose of 3000?IU/day is required to reach a desirable maternal 25-hydroxyvitamin D [25(OH)D] level, and to positively impact infant bone mineral content (BMC).Methods and analysis: This is a multicentre blinded randomised controlled trial. Pregnant women presenting to the Obstetrics and Gynaecology clinics will be approached. Eligible women will be randomised to daily equivalent doses of cholecalciferol, 600?IU or 3000?IU, from 15 to 18?weeks gestation until delivery. Maternal 25(OH)D and chemistries will be assessed at study entry, during the third trimester and at delivery. Neonatal anthropometric variables and 25(OH)D level will be measured at birth, and bone and fat mass assessment by dual-energy X-ray absorptiometry scan at 1?month. A sample size of 280 pregnant women is needed to demonstrate a statistically significant difference in the proportion of women reaching a 25(OH)D level ?50?nmol/L at delivery, and a difference in infant BMC of 6 (10)g, for a 90% power and a 2.5% level of significance. The proportions of women achieving a target 25(OH)D level will be compared between the two arms, using ?2. An independent t test will be used to compare mean infant BMC between the two arms. The primary analysis is an intention-to-treat analysis of unadjusted results.Ethics and dissemination: The protocol has been approved by the Institutional Review Board at the American University of Beirut-Lebanon (IM.GEHF.22). The trial results will be published in peer-reviewed medical journals and presented at scientific conferences.Trial registration number: NCT02434380.<br/

    Mechanical and X ray computed tomography characterisation of a WAAM 3D printed steel plate for structural engineering applications

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    This paper reports an investigation to improve fundamental knowledge and understanding of 3D printing of steel in structural engineering. The process method examined is Wire and Arc Additive Manufacturing (WAAM) for the manufacturing of large-sized components. The mechanical properties of 3D printed Union K 40 - GMAW steel are determined and benchmarked against measured properties of EN 8 carbon medium steel. The results presented and discussed are from tensile coupon testing and X-ray Computed Tomography, with the latter inspecting an internal volume of the WAAM steel for: printing orientation; mapping porosity; interfacial variation between the printed layers. The key finding is that the mechanical properties of the WAAM steel satisfy the requirements for a structural steel grade for building structures as specified by Eurocode 3 (EN 1993–1-1)

    Fractional Dynamics from Einstein Gravity, General Solutions, and Black Holes

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    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

    Assessment of Yeasts as Potential Probiotics: A Review of Gastrointestinal Tract Conditions and Investigation Methods

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    Probiotics are microorganisms (including bacteria, yeasts and moulds) that confer various health benefits to the host, when consumed in sufficient amounts. Food products containing probiotics, called functional foods, have several health-promoting and therapeutic benefits. The significant role of yeasts in producing functional foods with promoted health benefits is well documented. Hence, there is considerable interest in isolating new yeasts as potential probiotics. Survival in the gastrointestinal tract (GIT), salt tolerance and adherence to epithelial cells are preconditions to classify such microorganisms as probiotics. Clear understanding of how yeasts can overcome GIT and salt stresses and the conditions that support yeasts to grow under such conditions is paramount for identifying, characterising and selecting probiotic yeast strains. This study elaborated the adaptations and mechanisms underlying the survival of probiotic yeasts under GIT and salt stresses. This study also discussed the capability of yeasts to adhere to epithelial cells (hydrophobicity and autoaggregation) and shed light on in vitro methods used to assess the probiotic characteristics of newly isolated yeasts

    Power management and control strategies for off-grid hybrid power systems with renewable energies and storage

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    This document is the Accepted Manuscript of the following article: Belkacem Belabbas, Tayeb Allaoui, Mohamed Tadjine, and Mouloud Denai, 'Power management and control strategies for off-grid hybrid power systems with renewable energies and storage', Energy Systems, September 2017. Under embargo. Embargo end date: 19 September 2018. The final publication is available at Springer via https://doi.org/10.1007/s12667-017-0251-y.This paper presents a simulation study of standalone hybrid Distributed Generation Systems (DGS) with Battery Energy Storage System (BESS). The DGS consists of Photovoltaic (PV) panels as Renewable Power Source (RPS), a Diesel Generator (DG) for power buck-up and a BESS to accommodate the surplus of energy, which may be employed in times of poor PV generation. While off-grid DGS represent an efficient and cost-effective energy supply solution particularly to rural and remote areas, fluctuations in voltage and frequency due to load variations, weather conditions (temperature, irradiation) and transmission line short-circuits are major challenges. The paper suggests a hierarchical Power Management (PM) and controller structure to improve the reliability and efficiency of the hybrid DGS. The first layer of the overall control scheme includes a Fuzzy Logic Controller (FLC) to adjust the voltage and frequency at the Point of Common Coupling (PCC) and a Clamping Bridge Circuit (CBC) which regulates the DC bus voltage. A maximum power point tracking (MPPT) controller based on FLC is designed to extract the optimum power from the PV. The second control layer coordinates among PV, DG and BESS to ensure reliable and efficient power supply to the load. MATLAB Simulink is used to implement the overall model of the off-grid DGS and to test the performance of the proposed control scheme which is evaluated in a series of simulations scenarios. The results demonstrated the good performance of the proposed control scheme and effective coordination between the DGS for all the simulation scenarios considered.Peer reviewedFinal Accepted Versio

    Inactivation of <i>Cronobacter sakazakii</i> in reconstituted infant milk formula by plant essential oils

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    This study aimed to screen the in vitro antimicrobial activity of 10 plant essential oils (EOs) against 4 Cronobacter sakazakii strains, and use these oils or their combination to control C. sakazakii cocktail at low (3 log10 CFU/ml) and high (6 log10 CFU/ml) contamination levels in reconstituted infant milk formula (RIMF). Cinnamon and fir oils were the most inhibitory to C. sakazakii strains with inhibition zone of 32 to 40 mm at 20 µl/disc (the minimum inhibitory concentrations were 0.16 and 0.625 µl/ml, respectively). The addition of each of cinnamon or fir oil at 1% (v/v) reduced the C. sakazakii numbers in RIMF by 0.7-0.8 log10 CFU/ml when inoculated with high contamination level and by 2.5-3.1 log10 CFU/ml when inoculated with low contamination level. However, the combination of cinnamon and fir oils reduced C. sakazakii numbers at both inoculum levels to undetectable levels after 3 h of incubation at 37°C. The results of the current study indicated that a combination of cinnamon and fir oils has a potent antimicrobial activity which may potentially be used to control C. sakazakii in RIMF

    Hunting for the high-affinity state of G-protein coupled receptors with agonist tracers:Theoretical and practical considerations for positron emission tomography (PET) imaging

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    The concept of the high-affinity state postulates that a certain subset of G-protein-coupled receptors is primarily responsible for receptor signaling in the living brain. Assessing the abundance of this subset is thus potentially highly relevant for studies concerning the responses of neurotransmission to pharmacological or physiological stimuli, and the dysregulation of neurotransmission in neurological or psychiatric disorders. The high-affinity state is preferentially recognized by agonists in vitro. For this reason, agonist tracers have been developed as tools for the non-invasive imaging of the high-affinity state with positron emission tomography (PET). This review provides an overview of agonist tracers that have been developed for PET imaging of the brain, and the experimental paradigms that have been developed for the estimation of the relative abundance of receptors configured in the high-affinity state. Agonist tracers appear to be more sensitive to endogenous neurotransmitter challenge than antagonists, as was originally expected. However, other expectations regarding agonist tracers have not been fulfilled. Potential reasons for difficulties in detecting the high-affinity state in vivo are discussed
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