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Paediatric asthma clinical pathway: Impact on cost and quality of care
No full textINTRODUCTION: Uncontrolled asthma may cause an increase in healthcare utilisation, hospital admission and productivity loss. With the increasing burden of asthma in Malaysia, strategies aimed at reducing cost of care should be explored. OBJECTIVE: This study aims to determine if a clinical pathway (CPW) for inpatient paediatric asthma would reduce average length of stay (ALOS), improve asthma management and decrease cost. METHODS: A quasi-experimental, pre-post study was used to evaluate the CPW effectiveness. Paediatric inpatients aged 5-18 years old, admitted for acute asthma exacerbation from September 2015 to April 2016 were prospectively recruited. Data from patients admitted from January-July 2015 were used as control. CPW training was carried out in August 2015 using standardised modules. Direct admission cost from the provider’s prospective was calculated. Outcomes compared were differences in ALOS, discharge medication, readmission within 28 days of discharge and cost. RESULTS: ALOS is 26 hours lower in the CPW group for severe exacerbations and underlying uncontrolled asthma (19.2 hours) which is clinically significant as patients have shorter hospital stay. More newly-diagnosed intermittent asthmatics were discharged with relievers in the CPW group (p-value 0.006). None of the patients in the CPW group had readmissions (p-value 0.16). Mean treatment cost for patients in the intervention group is higher at RM843.39 (SD ±48.99, versus RM779.21 SD±44.33). CONCLUSION: This study found that management using a CPW may benefit asthmatic patients with uncontrolled asthma admitted with severe exacerbation. Further studies will be needed to explore CPW’s impact on asthma management starting from the emergency department. © 2019, Malaysian Medical Association. All rights reserved
Platelet-rich concentrate in serum-free medium enhances cartilage-specific extracellular matrix synthesis and reduces chondrocyte hypertrophy of human mesenchymal stromal cells encapsulated in alginate
No full textPlatelet-rich concentrate (PRC), used in conjunction with other chondroinductive growth factors, have been shown to induce chondrogenesis of human mesenchymal stromal cells (hMSC) in pellet culture. However, pellet culture systems promote cell hypertrophy and the presence of other chondroinductive growth factors in the culture media used in previous studies obscures accurate determination of the effect of platelet itself in inducing chondrogenic differentiation. Hence, this study aimed to investigate the effect of PRC alone in enhancing the chondrogenic differentiation potential of human mesenchymal stromal cells (hMSC) encapsulated in three-dimensional alginate constructs. Cells encapsulated in alginate were cultured in serum-free medium supplemented with only 15% PRC. Scanning electron microscopy was used to determine the cell morphology. Chondrogenic molecular signature of hMSCs was determined by quantitative real-time PCR and verified at protein levels via immunohistochemistry and enzyme-linked immunosorbent assay. Results showed that the cells cultured in the presence of PRC for 24 days maintained a chondrocytic phenotype and demonstrated minimal upregulation of cartilaginous extracellular matrix (ECM) marker genes (SOX9, TNC, COL2, ACAN, COMP) and reduced expression of chondrocyte hypertrophy genes (Col X, Runx2) compared to the standard chondrogenic medium (p < 0.05). PRC group had correspondingly higher levels of glycosaminoglycan and increased concentration of chondrogenic specific proteins (COL2, ACAN, COMP) in the ECM. In conclusion, PRC alone appears to be very potent in inducing chondrogenic differentiation of hMSCs and offers additional benefit of suppressing chondrocyte hypertrophy, rendering it a promising approach for providing abundant pool of chondrogenic MSCs for application in cartilage tissue engineering. © 2017, © 2017 Taylor & Francis
Experimental investigations of the effect of the neutral gas pressure on the separate control of ion energy and flux in dual frequency capacitively coupled plasmas
No full textClassical dual-frequency capacitively coupled plasmas (2f CCPs) operating at low pressures and significantly different frequencies are often used for a variety of applications in semiconductor manufacturing in order to control the mean ion energy at the electrodes separately from the ion flux. However, recent computational studies have indicated that this separate control is limited by the frequency coupling effects and by the contribution of secondary electrons to the ionization dynamics [Donkó et al., Appl. Phys. Lett. 97, 081501 (2010); Schulze et al., Plasma Sources Sci. Technol. 20, 045007 (2011)]. Here, we verify these simulation results experimentally by measuring the ion flux to an electrode as a function of the low frequency (LF) and high frequency power at different neutral gas pressures in a 2f CCP operated at 2.26 MHz and 13.56 MHz in argon. In agreement with previous computational predictions, we find the ion flux to decrease as a function of the LF power at a low pressure of 1 mTorr due to the frequency coupling and to increase as a function of the LF power at a higher pressure of 60 mTorr due to the presence of secondary electrons. These experimental findings show that separate control of ion properties in classical 2f CCPs is generally not possible, but potentially limited to specific discharge conditions. © 2019 Author(s)
Enhancing the Efficiency of a Dye-Sensitized Solar Cell Based on a Metal Oxide Nanocomposite Gel Polymer Electrolyte
No full textTo overcome the critical limitations of liquid-electrolyte-based dye-sensitized solar cells, quasi-solid-state electrolytes have been explored as a means of addressing long-term device stability, albeit with comparatively low ionic conductivities and device performances. Although metal oxide additives have been shown to augment ionic conductivity, their propensity to aggregate into large crystalline particles upon high-heat annealing hinders their full potential in quasi-solid-state electrolytes. In this work, sonochemical processing has been successfully applied to generate fine Co3O4 nanoparticles that are highly dispersible in a PAN:P(VP-co-VAc) polymer-blended gel electrolyte, even after calcination. An optimized nanocomposite gel polymer electrolyte containing 3 wt % sonicated Co3O4 nanoparticles (PVVA-3) delivers the highest ionic conductivity (4.62 × 10-3 S cm-1) of the series. This property is accompanied by a 51% enhancement in the apparent diffusion coefficient of triiodide versus both unmodified and unsonicated electrolyte samples. The dye-sensitized solar cell based on PVVA-3 displays a power conversion efficiency of 6.46% under AM1.5 G, 100 mW cm-2. By identifying the optimal loading of sonochemically processed nanoparticles, we are able to generate a homogenous extended particle network that effectively mobilizes redox-active species through a highly amorphous host matrix. This effect is manifested in a selective 51% enhancement in photocurrent density (JSC = 16.2 mA cm-2) and a lowered barrier to N719 dye regeneration (RCT = 193 ω) versus an unmodified solar cell. To the best of our knowledge, this work represents the highest known efficiency to date for dye-sensitized solar cells based on a sonicated Co3O4-modified gel polymer electrolyte. Sonochemical processing, when applied in this manner, has the potential to make meaningful contributions toward the ongoing mission to achieve the widespread exploitation of stable and low-cost dye-sensitized solar cells. Copyright © 2019 American Chemical Society
Prevalence of growth and endocrine disorders in Malaysian children with transfusion-dependent thalassaemia
No full textINTRODUCTION Endocrine dysfunction due to iron overload secondary to frequent blood transfusions is a common complication in children with transfusion-dependent thalassaemia (TDT). We ascertained the prevalence of endocrine dysfunction in children with TDT seen in a hospital setting in Malaysia. METHODS We reviewed all patients with TDT who had ≥ 8 blood transfusions per year. Patients who had a history of stem cell transplantation, concurrent autoimmune diseases or were newly diagnosed to have TDT were excluded. Standard diagnostic criteria were used in the diagnosis of various endocrine dysfunctions. RESULTS Of the 82 patients with TDT, 65% had at least one endocrine dysfunction. Short stature was the commonest (40.2%), followed by pubertal disorders (14.6%), hypoparathyroidism (12.3%), vitamin D deficiency (10.1%), hypocortisolism (7.3%), diabetes mellitus (5.2%) and overt hypothyroidism (4.9%). Subclinical hypothyroidism and pre-diabetes mellitus were seen in 13.4% and 8.6% of the patients, respectively. For children aged 10 years of age. Close monitoring for endocrine dysfunction and hormonal therapy is essential to prevent long-term adverse outcomes. © 2019, Singapore Medical Association. All rights reserved
Experimental assessment on feasibility of computed tomography-based thermometry for radiofrequency ablation on tissue equivalent polyacrylamide phantom
No full textPurpose: This study aimed to evaluate the effects of various computed tomography (CT) acquisition parameters and metal artifacts on CT number measurement for CT thermometry during CT-guided thermal ablation. Methods: The effects of tube voltage (100–140 kVp), tube current (20–250 mAs), pitch (0.6–1.5) and gantry rotation time (0.5, 1.0 s) as well as metal artifacts from a radiofrequency ablation (RFA) needle on CT number were evaluated using liver tissue equivalent polyacrylamide (PAA) phantom. The correlation between CT number and temperature from 37 to 80 °C was studied on PAA phantom using optimum CT acquisition parameters. Results: No statistical significant difference (p > 0.05) was found on CT numbers under the variation of different acquisition parameters for the same temperature setting. On the other hand, the RFA needle has induced metal artifacts on the CT images of up to 8 mm. The CT numbers decreased linearly when the phantom temperature increased from 37 to 80 °C. A linear regression analysis on the CT numbers and temperature suggested that the CT thermal sensitivity was –0.521 ± 0.061 HU/°C (R2 = 0.998). Conclusion: CT thermometry is feasible for temperature assessment during RFA with the current CT technology, which produced a high CT number reproducibility and stable measurement at different CT acquisition parameters. Despite being affected by metal artifacts, the CT-based thermometry could be further developed as a tissue temperature monitoring tool during CT-guided thermal ablation. © 2019, © 2019 The Author(s). Published with license by Taylor & Francis Group, LLC
Cell surface α2,3-linked sialic acid facilitates Zika virus internalization
No full textThe emergence of neurotropic Zika virus (ZIKV) raised a public health emergency of global concern. ZIKV can cross the placental barrier and infect foetal brains, resulting in microcephaly, but the pathogenesis of ZIKV is poorly understood. With recent findings reporting AXL as a type I interferon antagonist rather than an entry receptor, the exact entry mechanism remains unresolved. Here we report that cell surface sialic acid plays an important role in ZIKV infection. Removal of cell surface sialic acid by neuraminidase significantly abolished ZIKV infection in Vero cells and human induced-pluripotent stem cells-derived neural progenitor cells. Furthermore, knockout of the sialic acid biosynthesis gene encoding UDP-N-acetylglucosamine-2-epimerase/N-acetylmannosamine kinase resulted in significantly less ZIKV infection of both African and Asian lineages. Huh7 cells deficient in α2,3-linked sialic acid through knockout of ST3 β-galactoside-α2,3-sialyltransferase 4 had significantly reduced ZIKV infection. Removal of membrane-bound, un-internalized virus with pronase treatment revealed the role of sialic acid in ZIKV internalization but not attachment. Sialyllactose inhibition studies showed that there is no direct interaction between sialic acid and ZIKV, implying that sialic acid could be mediating ZIKV-receptor complex internalization. Identification of α2,3-linked sialic acid as an important host factor for ZIKV internalization provides new insight into ZIKV infection and pathogenesis. © 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group, on behalf of Shanghai Shangyixun Cultural Communication Co., Ltd
Liraglutide in Children and Adolescents with Type 2 Diabetes
No full textBACKGROUND Metformin is the regulatory-approved treatment of choice for most youth with type 2 diabetes early in the disease. However, early loss of glycemic control has been observed with metformin monotherapy. Whether liraglutide added to metformin (with or without basal insulin treatment) is safe and effective in youth with type 2 diabetes is unknown. METHODS Patients who were 10 to less than 17 years of age were randomly assigned, in a 1:1 ratio, to receive subcutaneous liraglutide (up to 1.8 mg per day) or placebo for a 26-week double-blind period, followed by a 26-week open-label extension period. Inclusion criteria were a body-mass index greater than the 85th percentile and a glycated hemoglobin level between 7.0 and 11.0% if the patients were being treated with diet and exercise alone or between 6.5 and 11.0% if they were being treated with metformin (with or without insulin). All the patients received metformin during the trial. The primary end point was the change from baseline in the glycated hemoglobin level after 26 weeks. Secondary end points included the change in fasting plasma glucose level. Safety was assessed throughout the course of the trial. RESULTS Of 135 patients who underwent randomization, 134 received at least one dose of liraglutide (66 patients) or placebo (68 patients). Demographic characteristics were similar in the two groups (mean age, 14.6 years). At the 26-week analysis of the primary efficacy end point, the mean glycated hemoglobin level had decreased by 0.64 percentage points with liraglutide and increased by 0.42 percentage points with placebo, for an estimated treatment difference of-1.06 percentage points (P<0.001); the difference increased to-1.30 percentage points by 52 weeks. The fasting plasma glucose level had decreased at both time points in the liraglutide group but had increased in the placebo group. The number of patients who reported adverse events was similar in the two groups (56 [84.8%] with liraglutide and 55 [80.9%] with placebo), but the overall rates of adverse events and gastrointestinal adverse events were higher with liraglutide. CONCLUSIONS In children and adolescents with type 2 diabetes, liraglutide, at a dose of up to 1.8 mg per day (added to metformin, with or without basal insulin), was efficacious in improving glycemic control over 52 weeks. This efficacy came at the cost of an increased frequency of gastrointestinal adverse events. (Funded by Novo Nordisk; Ellipse ClinicalTrials.gov number, NCT01541215.). © 2019 Massachusetts Medical Society
A new hybrid GA−ACO−PSO algorithm for solving various engineering design problems
No full textThe intention of this hybridization is to further enhance the exploratory and exploitative search capabilities involving simple concepts. The proposed algorithm adopts the combined discrete and continuous probability distribution scheme of ant colony optimization (ACO) to specifically assist genetic algorithm in the aspect of exploratory search. Besides, distinctive crossover and mutation operators are introduced, in which, two types of mutation operators, namely, standard mutation and refined mutation are suggested. In early iterations, standard mutation is utilized collaboratively with the concept of unrepeated tours of ACO to evade local entrapment, while refined mutation is used in later iterations to supplement the exploitative search, which is mainly controlled by particle swarm optimization. The proposed method has been validated in solving test functions and well-known engineering design problems. It exhibits a great global search capability even in the presence of non-linearity, multimodality and constraints, involving a large number of dimensions as well as large search areas. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group
Efficiency enhancement study on addition of 1-hexyl-3-methylimidazolium iodide ionic liquid to the poly(methyl methacrylate-co-methacrylic acid) electrolyte system as applied in dye-sensitized solar cells
No full textThe replacement of liquid electrolytes with gel polymer substituents in dye-sensitized solar cells (DSSCs) has become an accepted strategy not only to overcome problems encountered previously but also to increase the shelf life and photovoltaic performance of DSSCs. In that perspective, a gel polymer electrolyte system based on poly(methyl methacrylate-co-methacrylic acid), P(MMA-co-MAA), was prepared with iodine/iodide redox mediator from a sodium salt and the commercially available ionic liquid 1-hexyl-3-methylimidazolium iodide (HMIm + I − ) and was studied for its ionic conductivity and energy conversion efficiencies along with structural investigation of the complex by Fourier transform infrared spectroscopy and X-ray diffraction. The highest conductivity achieved was 2.33 mS cm −1 at room temperature for the gel polymer electrolyte with 20 wt% HMIm + I − . With a generic DSSC arrangement of TiO 2 sensitized with N719 dye photoanode/electrolyte/Pt-containing counter electrode, the copolymer-based conducting electrolyte displayed power conversion efficiency of 5.30% under illumination of 100 mW cm −2 . © 2019 Elsevier Lt