| 1. |
- Drake, TM, et al.
(author)
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Surgical site infection after gastrointestinal surgery in children: an international, multicentre, prospective cohort study
- 2020
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In: BMJ global health. - : BMJ. - 2059-7908. ; 5:12
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Journal article (peer-reviewed)abstract
- Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). However, there is a lack of data available about SSI in children worldwide, especially from low-income and middle-income countries. This study aimed to estimate the incidence of SSI in children and associations between SSI and morbidity across human development settings.MethodsA multicentre, international, prospective, validated cohort study of children aged under 16 years undergoing clean-contaminated, contaminated or dirty gastrointestinal surgery. Any hospital in the world providing paediatric surgery was eligible to contribute data between January and July 2016. The primary outcome was the incidence of SSI by 30 days. Relationships between explanatory variables and SSI were examined using multilevel logistic regression. Countries were stratified into high development, middle development and low development groups using the United Nations Human Development Index (HDI).ResultsOf 1159 children across 181 hospitals in 51 countries, 523 (45·1%) children were from high HDI, 397 (34·2%) from middle HDI and 239 (20·6%) from low HDI countries. The 30-day SSI rate was 6.3% (33/523) in high HDI, 12·8% (51/397) in middle HDI and 24·7% (59/239) in low HDI countries. SSI was associated with higher incidence of 30-day mortality, intervention, organ-space infection and other HAIs, with the highest rates seen in low HDI countries. Median length of stay in patients who had an SSI was longer (7.0 days), compared with 3.0 days in patients who did not have an SSI. Use of laparoscopy was associated with significantly lower SSI rates, even after accounting for HDI.ConclusionThe odds of SSI in children is nearly four times greater in low HDI compared with high HDI countries. Policies to reduce SSI should be prioritised as part of the wider global agenda.
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| 2. |
- Abbasiasl, Taher, et al.
(author)
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Effect of intensified cavitation using poly (vinyl alcohol) microbubbles on spray atomization characteristics in microscale
- 2020
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In: AIP Advances. - : American Institute of Physics (AIP). - 2158-3226. ; 10:2
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Journal article (peer-reviewed)abstract
- In this study, cavitating flows inside a transparent cylindrical nozzle with an inner diameter of 0.9 mm were visualized, and the effect of cavitation on atomization characteristics of emerging sprays was investigated. Different patterns of cavitating flows inside the nozzle were visualized using a high-speed camera. In-house codes were developed to process the captured images to study the droplet size distribution and droplet velocity in different flow regimes. The results show that cavitating flows at the microscale have significant effects on atomization characteristics of the spray. Two working fluids, namely, water and poly(vinyl alcohol) microbubble (PVA MB) suspension, were employed. Accordingly, the injection pressures were detected as 690 kPa, 1035 kPa, and 1725 kPa for cavitation inception, supercavitation, and hydraulic flip flow regimes in the case of water, respectively. The corresponding pressures for the aforementioned patterns for PVA MB suspension were 590 kPa, 760 kPa, and 1070 kPa, respectively. At the microscale, as a result of a higher volume fraction of cavitation bubbles inside the nozzle, there is no large difference between the cavitation numbers corresponding to cavitating and hydraulic flip flows. Although the percentage of droplets with diameters smaller than 200 μm was roughly the same for both cases of water and PVA MB suspension, the Sauter mean diameter was considerably lower in the case of PVA MBs. Moreover, higher droplet velocities were achieved in the case of PVA MBs at lower injection pressures.
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| 3. |
- Alsabery, Ammar I., et al.
(author)
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Role of Rotating Cylinder toward Mixed Convection inside a Wavy Heated Cavity via Two-Phase Nanofluid Concept
- 2020
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In: Nanomaterials. - : MDPI. - 2079-4991. ; 10:6
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Journal article (peer-reviewed)abstract
- The mixed convection two-phase flow and heat transfer of nanofluids were addressed within a wavy wall enclosure containing a solid rotating cylinder. The annulus area between the cylinder and the enclosure was filled with water-alumina nanofluid. Buongiorno's model was applied to assess the local distribution of nanoparticles in the host fluid. The governing equations for the mass conservation of nanofluid, nanoparticles, and energy conservation in the nanofluid and the rotating cylinder were carried out and converted to a non-dimensional pattern. The finite element technique was utilized for solving the equations numerically. The influence of the undulations, Richardson number, the volume fraction of nanoparticles, rotation direction, and the size of the rotating cylinder were examined on the streamlines, heat transfer rate, and the distribution of nanoparticles. The Brownian motion and thermophoresis forces induced a notable distribution of nanoparticles in the enclosure. The best heat transfer rate was observed for 3% volume fraction of alumina nanoparticles. The optimum number of undulations for the best heat transfer rate depends on the rotation direction of the cylinder. In the case of counterclockwise rotation of the cylinder, a single undulation leads to the best heat transfer rate for nanoparticles volume fraction about 3%. The increase of undulations number traps more nanoparticles near the wavy surface.
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| 4. |
- Elsharkawi, Ibrahim, et al.
(author)
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Exploring the effect of epigenetic modifiers on developing insulin-secreting cells
- 2020
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In: HUMAN CELL. - : SPRINGER JAPAN KK. - 1749-0774 .- 0914-7470. ; 33, s. 1-9
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Journal article (peer-reviewed)abstract
- Diabetes is a worldwide health problem with increasing incidence. The current management modalities did not succeed to decrease comorbidities. This study aimed at enhancing the regenerative solution for diabetes by improving the differentiation of mesenchymal stromal cells (MSC) into glucose-sensitive, insulin-secreting cells through an epigenetic modification approach. A 3-day treatment protocol with the epigenetic modifiers, either decitabine (5-aza-2 -deoxycytidine; Aza); a DNA methylation inhibitor or Vorinostat (suberoylanilide hydroxamic acid; SAHA); a histone deacetylase inhibitor was added to two different human stem cell lines. The cells followed a multi-step differentiation protocol that provided the critical triggers in a temporal approach. Aza-pretreated group showed higher intracellular expression of insulin and the transcription factor PDX-1. The cells responded to the high glucose challenge by secreting insulin in the media, as shown by ELISA. Gene expression showed induction of the genes for insulin, the glucose transporter 2, glucokinase, as well as the transcription factors MafA and NKX6.1. Although SAHA showed upregulation of insulin secretion, in comparison to control, the cells could not respond to the high glucose challenge. Interestingly, Aza-treated cells showed a significant decrease in the global DNA methylation level at the end of the culture. In conclusion, this additional step with Aza could enhance the response of MSC to the classical differentiation protocol for insulin-secreting cells and may help in establishing a regenerative solution for patients with diabetes.
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| 5. |
- Gevari, Moein Talebian, et al.
(author)
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Direct and indirect thermal applications of hydrodynamic and acoustic cavitation : A review
- 2020
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In: Applied Thermal Engineering. - : Elsevier. - 1359-4311 .- 1873-5606. ; 171
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Research review (peer-reviewed)abstract
- The phase change phenomenon in fluids as a result of low local pressure under a critical value is known as cavitation. Acoustic wave propagation or hydrodynamic pressure drop of the working fluid are the main reasons for inception of this phenomenon. Considering the released energy from the collapsing cavitation bubbles as a reliable source has led to its implementation to different fields, namely, heat transfer, surface cleaning and fouling, water treatment, food industry, chemical reactions, energy harvesting. A considerable amount of energy in the mentioned industries is required for thermal applications. Cavitation could serve for minimizing the energy demand and optimizing the processes. Thus, the energy efficiency of the systems could be significantly enhanced. This review article focuses on the direct and indirect thermal applications of hydrodynamic and acoustic cavitation. Relevant studies with emerging applications are discussed, while developments in cavitation, which have given rise to thermal applications during the last decade, are also included in this review.
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| 6. |
- Khan, Amir Ali, et al.
(author)
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Significant transcriptomic changes are associated with differentiation of bone marrow-derived mesenchymal stem cells into neural progenitor-like cells in the presence of bFGF and EGF
- 2020
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In: Cell & Bioscience. - : BMC. - 2045-3701. ; 10:1
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Journal article (peer-reviewed)abstract
- IntroductionMesenchymal stem cells (MSCs) isolated from bone marrow have different developmental origins, including neural crest. MSCs can differentiate into neural progenitor-like cells (NPCs) under the influence of bFGF and EGF. NPCs can terminally differentiate into neurons that express beta-III-tubulin and elicit action potential. The main aim of the study was to identify key genetic markers involved in differentiation of MSCs into NPCs through transcriptomic analysis.MethodTotal RNA was isolated from MSCs and MSCs-derived NPCs followed by cDNA library construction for transcriptomic analysis. Sample libraries that passed the quality and quantity assessments were subjected to high throughput mRNA sequencing using NextSeq (R) 500. Differential gene expression analysis was performed using the DESeq2 R package with MSC samples being a reference group. The expression of eight differentially regulated genes was counter validated using real-time PCR.ResultsIn total, of the 3,252 differentially regulated genes between MSCs and NPCs with two or more folds, 1,771 were upregulated genes, whereas 1,481 were downregulated in NPCs. Amongst these differential genes, 104 transcription factors were upregulated, and 45 were downregulated in NPCs. Neurogenesis related genes were upregulated in NPCs and the main non-redundant gene ontology (GO) terms enriched in NPCs were the autonomic nervous system, cell surface receptor signalling pathways), extracellular structure organisation, and programmed cell death. The main non-redundant GO terms enriched in MSCs included cytoskeleton organisation cytoskeleton structural constituent, mitotic cell cycle), and the mitotic cell cycle process Gene set enrichment analysis also confirmed cell cycle regulated pathways as well as Biocarta integrin pathway were upregulated in MSCs. Transcription factors enrichment analysis by ChEA3 revealed Foxs1 and HEYL, amongst the top five transcription factors, inhibits and enhances, respectively, the NPCs differentiation of MSCs.ConclusionsThe vast differences in the transcriptomic profiles between NPCs and MSCs revealed a set of markers that can identify the differentiation stage of NPCs as well as provide new targets to enhance MSCs differentiation into NPCs.
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