50 research outputs found

    CFD modelling for dams and reservoirs – best practice workflows, specification and review

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    This paper identifies the need for industry guidance for the application of computational fluid dynamics (CFD) to the dams and reservoirs industry and lays out the primary components of such a model study, providing guidance for procurement and review. First, workflow is discussed to give an overview to those unfamiliar with the process. The key areas are explicitly explained for the layperson. The later part of the paper identifies key issues that reviewers should focus on and discusses areas such as accuracy. Support is offered to owners and those procuring model studies in the form of sample text recommended for specifying CFD studies. Finally, the paper recommends a high level of quality control and expert review when issues of dam safety are concerned

    Bioorthogonal Swarming: In Situ Generation of Dendrimers

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    With the aid of bioorthogonal chemistry, we demonstrate the fabrication of synthetic dendrimers in situ around living cells. Using tetrazine dienophile and aminooxyl/hydrazide aldehyde chemistries, the density of functional groups on the dendrimers exponentially amplified intensities of fluorescent markers in antibody-targeted live cell imaging. This novel “swarming” approach highlights the power of bioorthogonal chemistry and provides a route to non-natural chemical structures on cells, paving the way for the generation of various artificial cellular nanostructures and scaffolds

    MINPP1 prevents intracellular accumulation of the chelator inositol hexakisphosphate and is mutated in Pontocerebellar Hypoplasia

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    Inositol polyphosphates are vital metabolic and secondary messengers, involved in diverse cellular functions. Therefore, tight regulation of inositol polyphosphate metabolism is essential for proper cell physiology. Here, we describe an early-onset neurodegenerative syndrome caused by loss-of-function mutations in the multiple inositol-polyphosphate phosphatase 1 gene (MINPP1). Patients are found to have a distinct type of Pontocerebellar Hypoplasia with typical basal ganglia involvement on neuroimaging. We find that patient-derived and genome edited MINPP1−/− induced stem cells exhibit an inefficient neuronal differentiation combined with an increased cell death. MINPP1 deficiency results in an intracellular imbalance of the inositol polyphosphate metabolism. This metabolic defect is characterized by an accumulation of highly phosphorylated inositols, mostly inositol hexakisphosphate (IP6), detected in HEK293 cells, fibroblasts, iPSCs and differentiating neurons lacking MINPP1. In mutant cells, higher IP6 level is expected to be associated with an increased chelation of intracellular cations, such as iron or calcium, resulting in decreased levels of available ions. These data suggest the involvement of IP6-mediated chelation on Pontocerebellar Hypoplasia disease pathology and thereby highlight the critical role of MINPP1 in the regulation of human brain development and homeostasis

    Image-guided versus blind corticosteroid injections in adults with shoulder pain: A systematic review

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    <p>Abstract</p> <p>Background</p> <p>Corticosteroid injections can be performed blind (landmark-guided) or with image guidance, and this may account for variable clinical outcomes. The objective of this study was to assess the effectiveness and safety of image-guided versus blind corticosteroid injections in improving pain and function among adults with shoulder pain.</p> <p>Methods</p> <p>MEDLINE, the Cochrane Controlled Trials Register and EMBASE were searched to May 2010. Additional studies were identified by searching bibliographies of shortlisted articles. Search items included blind, landmark, anatomical, clinical exam, image-guided, ultrasound, fluoroscopy, steroid injection, frozen shoulder, random allocation, randomized controlled trial (RCT) and clinical trial.</p> <p>Randomized controlled studies comparing image-guided versus blind (landmark-guided) corticosteroid shoulder injections that examined pain, function and/or adverse events were included. Independent extraction was done by two authors using a form with pre-specified data fields, including risk of bias appraisal. Conflicts were resolved by discussion. The decision to pool data was based on assessment of clinical design homogeneity. When warranted, studies were pooled under a random-effects model.</p> <p>Results</p> <p>Two RCTs for pain, function and adverse events (n = 101) met eligibility criteria. No serious threats to validity were found. Both trials compared ultrasound-guided versus landmark-guided injections and were judged similar in clinical design. Low to moderate heterogeneity was observed: shoulder pain I<sup>2 </sup>= 60%, function I<sup>2 </sup>= 22%. A meta-analysis demonstrated greater improvement with ultrasound-guided injections at 6 weeks after injection in both pain (mean difference = 2.23 [95% CI: 1.27, 3.18]), as assessed with a 0 to 10 visual analogue scale, and shoulder function (standardised mean difference = 1.09 [95% CI: 0.61, 1.57]) as assessed with shoulder function scores. Although more adverse events (all mild) were reported with landmark-guided injections, the difference was not statistically significant (risk ratio = 0.20 [95% CI: 0.04, 1.13]).</p> <p>This review was only based on two moderate-sized trials. Blinding of patients was not performed in both trials, causing some risk of bias in outcome assessment since primary endpoints were wholly or partially patient-reported.</p> <p>Conclusion</p> <p>There is a paucity of RCTs on image-guided versus landmark-guided corticosteroid shoulder injections examining pain, function and adverse events. In this review, patients who underwent image-guided (ultrasound) injections had statistically significant greater improvement in shoulder pain and function at 6 weeks after injection. Image-guided (ultrasound) corticosteroid injections potentially offer a significantly greater clinical improvement over blind (landmark-guided) injections in adults with shoulder pain. However, this apparent benefit requires confirmation from further studies (adequately-powered and well-executed RCTs).</p

    Combined Notch and PDGF Signaling Enhances Migration and Expression of Stem Cell Markers while Inducing Perivascular Cell Features in Muscle Satellite Cells

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    Satellite cells are responsible for skeletal muscle regeneration. Upon activation, they proliferate as transient amplifying myoblasts, most of which fuse into regenerating myofibers. Despite their remarkable differentiation potential, these cells have limited migration capacity, which curtails clinical use for widespread forms of muscular dystrophy. Conversely, skeletal muscle perivascular cells have less myogenic potential but better migration capacity than satellite cells. Here we show that modulation of Notch and PDGF pathways, involved in developmental specification of pericytes, induces perivascular cell features in adult mouse and human satellite cell-derived myoblasts. DLL4 and PDGF-BB-treated cells express markers of perivascular cells and associate with endothelial networks while also upregulating markers of satellite cell self-renewal. Moreover, treated cells acquire trans-endothelial migration ability while remaining capable of engrafting skeletal muscle upon intramuscular transplantation. These results extend our understanding of muscle stem cell fate plasticity and provide a druggable pathway with clinical relevance for muscle cell therapy

    Oral and Dental Health in Children with Chronic Liver Disease in the Turkey Northeast

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    Background: It is important to be aware of oral and dental problems in the early period in children with chronic liver disease (CLD) to prevent late complications. Therefore, we aimed to analyze the oral and dental health status in children with CLD. Methods: The three groups of children (3–18 years old); Group 1 (disease group, n = 31) patients with CLD, Group 2 (disease control group, n = 17) patients with chronic renal failure, and Group 3 healthy children (control group, n = 35). Examination of oral and dental structures were made, and then salivary parameters were analyzed. Antegonial index were calculated from panoramic X‑rays. Results: Enamel hypoplasia was found in 54.8%, 41.1%, and 31.4% of the children in the Groups 1, 2, and 3, respectively (P1‑3 &lt; 0.05). High salivary buffer capacity was found in 45.2% and 70.6% of the patients in Groups 1 and 2, respectively, and 45.7% of the children in healthy group, (P1‑2 and P2‑3 &lt; 0.05). Factors associated with enamel hypoplasia in patients with CLD were male gender (64.7% vs. 21.4%, P &lt; 0.05) and the presence of malnutrition (41.1% vs. 7.1%, P &lt; 0.05). Conclusion: Pediatric hepatologists must be aware of the dental problems in children with CLD. Enamel hypoplasia is common in children with CLD, and it may predispose to dental caries.Keywords: Chronic liver disease, dental health, enamel hypoplasi
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