848 research outputs found
Comparison of aerodynamic models for Vertical Axis Wind Turbines
Multi-megawatt Vertical Axis Wind Turbines (VAWTs) are experiencing an increased interest for floating offshore applications. However, VAWT development is hindered by the lack of fast, accurate and validated simulation models. This work compares six different numerical models for VAWTS: a multiple streamtube model, a double-multiple streamtube model, the actuator cylinder model, a 2D potential flow panel model, a 3D unsteady lifting line model, and a 2D conformal mapping unsteady vortex model. The comparison covers rotor configurations with two NACA0015 blades, for several tip speed ratios, rotor solidity and fixed pitch angle, included heavily loaded rotors, in inviscid flow. The results show that the streamtube models are inaccurate, and that correct predictions of rotor power and rotor thrust are an effect of error cancellation which only occurs at specific configurations. The other four models, which explicitly model the wake as a system of vorticity, show mostly differences due to the instantaneous or time averaged formulation of the loading and flow, for which further research is needed.Aerodynamics, Wind Energy & PropulsionAerospace Engineerin
Insulin regulates carboxypeptidase E by modulating translation initiation scaffolding protein eIF4G1 in pancreatic β cells
Insulin resistance, hyperinsulinemia, and hyperproinsulinemia occur early in the pathogenesis of type 2 diabetes (T2D). Elevated levels of proinsulin and proinsulin intermediates are markers of β-cell dysfunction and are strongly associated with development of T2D in humans. However, the mechanism(s) underlying β-cell dysfunction leading to hyperproinsulinemia is poorly understood. Here, we show that disruption of insulin receptor (IR) expression in β cells has a direct impact on the expression of the convertase enzyme carboxypeptidase E (CPE) by inhibition of the eukaryotic translation initiation factor 4 gamma 1 translation initiation complex scaffolding protein that is mediated by the key transcription factors pancreatic and duodenal homeobox 1 and sterol regulatory element-binding protein 1, together leading to poor proinsulin processing. Reexpression of IR or restoring CPE expression each independently reverses the phenotype. Our results reveal the identity of key players that establish a previously unknown link between insulin signaling, translation initiation, and proinsulin processing, and provide previously unidentified mechanistic insight into the development of hyperproinsulinemia in insulin-resistant states
CONCEPTT: Continuous Glucose Monitoring in Women with Type 1 Diabetes in Pregnancy Trial: A multi-center, multi-national, randomized controlled trial - Study protocol.
BACKGROUND: Women with type 1 diabetes strive for optimal glycemic control before and during pregnancy to avoid adverse obstetric and perinatal outcomes. For most women, optimal glycemic control is challenging to achieve and maintain. The aim of this study is to determine whether the use of real-time continuous glucose monitoring (RT-CGM) will improve glycemic control in women with type 1 diabetes who are pregnant or planning pregnancy. METHODS/DESIGN: A multi-center, open label, randomized, controlled trial of women with type 1 diabetes who are either planning pregnancy with an HbA1c of 7.0 % to ≤10.0 % (53 to ≤ 86 mmol/mol) or are in early pregnancy (<13 weeks 6 days) with an HbA1c of 6.5 % to ≤10.0 % (48 to ≤ 86 mmol/mol). Participants will be randomized to either RT-CGM alongside conventional intermittent home glucose monitoring (HGM), or HGM alone. Eligible women will wear a CGM which does not display the glucose result for 6 days during the run-in phase. To be eligible for randomization, a minimum of 4 HGM measurements per day and a minimum of 96 hours total with 24 hours overnight (11 pm-7 am) of CGM glucose values are required. Those meeting these criteria are randomized to RT- CGM or HGM. A total of 324 women will be recruited (110 planning pregnancy, 214 pregnant). This takes into account 15 and 20 % attrition rates for the planning pregnancy and pregnant cohorts and will detect a clinically relevant 0.5 % difference between groups at 90 % power with 5 % significance. Randomization will stratify for type of insulin treatment (pump or multiple daily injections) and baseline HbA1c. Analyses will be performed according to intention to treat. The primary outcome is the change in glycemic control as measured by HbA1c from baseline to 24 weeks or conception in women planning pregnancy, and from baseline to 34 weeks gestation during pregnancy. Secondary outcomes include maternal hypoglycemia, CGM time in, above and below target (3.5-7.8 mmol/l), glucose variability measures, maternal and neonatal outcomes. DISCUSSION: This will be the first international multicenter randomized controlled trial to evaluate the impact of RT- CGM before and during pregnancy in women with type 1 diabetes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01788527 Registration Date: December 19, 2012
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Environmental management of assembled chemical weapons assessment program.
Environmental planning and management was an integral part of the ACWA Program planning process. To ensure that environmental protection issues could be addressed expeditiously and not delay the demonstrations, the PMACWA scaled the technology demonstrations such that simplified regulatory processes and existing research and development facilities could be used. The use of enclosed facilities for the demonstrations prevents any uncontrolled discharges to the environment and made it possible to conduct environmental assessments relatively quickly. The PMACWA also arranged for public briefings to ease any community concerns over the operations with chemical weapons. These steps precluded regulatory and community resistance to the ACWA activities. The cooperation of the regulators and stakeholders has been a key element in enabling the ACWA Program to move with the speed that it has to date. Technology demonstrations are currently underway and are scheduled to be completed in late May 1999. The data collected during these demonstrations will be used to prepare and submit a summary report to Congress by August 1999. The challenge continues for the ACWA management to guide the demonstrations to completion and to plan for possible pilot testing. As the scale of the ACWA facilities increase in size, the ease of reduced regulatory processes and environmental analyses will no longer be possible. However, the PMACWA will continue to explore all paths through the environmental process to speed the ACWA program to its goals while at the same time ensuring adequate protection of public health and safety and of the environment
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Technology resource document for the assembled chemical weapons assessment environmental impact statement. Vol. 4 : assembled systems for weapons destruction at Pueblo Chemical Depot.
This volume of the Technical Resource Document (TRD) for the ''Environmental Impact Statement (EIS) for the Design, Construction and Operation of One or More Pilot Test Facilities for Assembled Chemical Weapons Destruction Technologies at One or More Sites'' (PMACWA 2001c) pertains to the destruction of assembled chemical weapons (ACW) stored at Pueblo Chemical Depot (PCD), located outside Pueblo, Colorado. This volume presents technical and process information on each of the destruction technologies applicable to treatment of the specific ACW stored at PCD. The destruction technologies described are those that have been demonstrated during Phase I of the Assembled Chemical Weapons Assessment (ACWA) demonstration process (see Volume 1)
Diabetes and baseline glucose are associated with inflammation, left ventricular function and short- and long-term outcome in acute coronary syndromes: role of the novel biomarker Cyr 61.
Hyperglycemia in the setting of an acute coronary syndrome (ACS) impacts short term outcomes, but little is known about longer term effects. We therefore designed this study to firstly determine the association between hyperglycemia and short term and longer term outcomes in patients presenting with ACS and secondly evaluate the prognostic role of diabetes, body mass index (BMI) and the novel biomarker Cyr61 on outcomes.
The prospective Special Program University Medicine-Acute Coronary Syndrome (SPUM-ACS) cohort enrolled 2168 patients with ACS between December 2009 and October 2012, of which 2034 underwent PCI (93.8%). Patients were followed up for 12 months. Events were independently adjudicated by three experienced cardiologists. Participants were recruited from four tertiary hospitals in Switzerland: Zurich, Geneva, Lausanne and Bern. Participants presenting with acute coronary syndromes and who underwent coronary angiography were included in the analysis. Patients were grouped according to history of diabetes (or HbA1c greater than 6%), baseline blood sugar level (BSL; < 6, 6-11.1 and > 11.1 mmol/L) and body mass index (BMI). The primary outcome was major adverse cardiac events (MACE) which was a composite of myocardial infarction, stroke and all-cause death. Secondary outcomes included the individual components of the primary endpoint, revascularisations, bleeding events (BARC classification) and cerebrovascular events (ischaemic or haemorrhagic stroke or TIA).
Patients with hyperglycemia, i.e. BSL ≥ 11.1 mmol/L, had higher levels of C-reactive protein (CRP), white blood cell count (WBC), creatinine kinase (CK), higher heart rates and lower left ventricular ejection fraction (LVEF) and increased N-terminal pro-brain natriuretic peptide. At 30 days and 12 months, those with BSL ≥ 11.1 mmol/L had more MACE and death compared to those with BSL < 6.0 mmol/L or 6.0-11.1 mmol/L (HR-ratio 4.78 and 6.6; p < 0.001). The novel biomarker Cyr61 strongly associated with high BSL and STEMI and was independently associated with 1 year outcomes (HR 2.22; 95% CI 1.33-3.72; Tertile 3 vs. Tertile 1).
In this large, prospective, independently adjudicated cohort of in all comers ACS patients undergoing PCI, both a history of diabetes and elevated entry glucose was associated with inflammation and increased risk of MACE both at short and long-term. The mediators might involve increased sympathetic activation, inflammation and ischemia as reflected by elevated Cyr61 levels leading to larger levels of troponin and lower LVEF. Trial registration Clinical Trial Registration Number: NCT01000701. Registered October 23, 2009
Whole-body integration of gene expression and single-cell morphology
Animal bodies are composed of cell types with unique expression programs that implement their distinct locations, shapes, structures, and functions. Based on these properties, cell types assemble into specific tissues and organs. To systematically explore the link between cell-type-specific gene expression and morphology, we registered an expression atlas to a whole-body electron microscopy volume of the nereid Platynereis dumerilii. Automated segmentation of cells and nuclei identifies major cell classes and establishes a link between gene activation, chromatin topography, and nuclear size. Clustering of segmented cells according to gene expression reveals spatially coherent tissues. In the brain, genetically defined groups of neurons match ganglionic nuclei with coherent projections. Besides interneurons, we uncover sensory-neurosecretory cells in the nereid mushroom bodies, which thus qualify as sensory organs. They furthermore resemble the vertebrate telencephalon by molecular anatomy. We provide an integrated browser as a Fiji plugin for remote exploration of all available multimodal datasets
Large genomic rearrangements in the CFTR gene contribute to CBAVD
<p>Abstract</p> <p>Background</p> <p>By performing extensive scanning of whole coding and flanking sequences of the <it>CFTR (Cystic Fibrosis Transmembrane Conductance Regulator</it>) gene, we had previously identified point mutations in 167 out of 182 (91.7%) males with isolated congenital bilateral absence of the vas deferens (CBAVD). Conventional PCR-based methods of mutation analysis do not detect gross DNA lesions. In this study, we looked for large rearrangements within the whole <it>CFTR </it>locus in the 32 CBAVD patients with only one or no mutation.</p> <p>Methods</p> <p>We developed a semi-quantitative fluorescent PCR assay (SQF-PCR), which relies on the comparison of the fluorescent profiles of multiplex PCR fragments obtained from different DNA samples. We confirmed the gross alterations by junction fragment amplification and identified their breakpoints by direct sequencing.</p> <p>Results</p> <p>We detected two large genomic heterozygous deletions, one encompassing exon 2 (c.54-5811_c.164+2186del8108ins182) [or <it>CFTRdele2</it>], the other removing exons 22 to 24 (c.3964-3890_c.4443+3143del9454ins5) [or <it>CFTRdele 22_24</it>], in two males carrying a typical CBAVD mutation on the other parental <it>CFTR </it>allele. We present the first bioinformatic tool for exon phasing of the <it>CFTR </it>gene, which can help to rename the exons and the nomenclature of small mutations according to international recommendations and to predict the consequence of large rearrangements on the open reading frame.</p> <p>Conclusion</p> <p>Identification of large rearrangements further expands the <it>CFTR </it>mutational spectrum in CBAVD and should now be systematically investigated. We have designed a simple test to specifically detect the presence or absence of the two rearrangements identified in this study.</p
Mammalian lipid droplets are innate immune hubs integrating cell metabolism and host defense.
Lipid droplets (LDs) are the major lipid storage organelles of eukaryotic cells and a source of nutrients for intracellular pathogens. We demonstrate that mammalian LDs are endowed with a protein-mediated antimicrobial capacity, which is up-regulated by danger signals. In response to lipopolysaccharide (LPS), multiple host defense proteins, including interferon-inducible guanosine triphosphatases and the antimicrobial cathelicidin, assemble into complex clusters on LDs. LPS additionally promotes the physical and functional uncoupling of LDs from mitochondria, reducing fatty acid metabolism while increasing LD-bacterial contacts. Thus, LDs actively participate in mammalian innate immunity at two levels: They are both cell-autonomous organelles that organize and use immune proteins to kill intracellular pathogens as well as central players in the local and systemic metabolic adaptation to infection
Comparison of bioresorbable vs durable polymer drug-eluting stents in unprotected left main (from the RAIN-CARDIOGROUP VII Study)
International audienceAbstract Background There are limited data regarding the impact of bioresorbable polymer drug eluting stent (BP-DES) compared to durable polymer drug eluting stent (DP-DES) in patients treated with percutaneous coronary intervention using ultrathin stents in left main or bifurcations. Methods In the RAIN registry (ClinicalTrials NCT03544294, june 2018 retrospectively registered) patients with a ULM or bifurcation stenosis treated with PCI using ultrathin stents (struts thinner than 81 μm) were enrolled. The primary endpoint was the rate of target lesion revascularization (TLR); major adverse cardiovascular events (MACE, a composite of all-cause death, myocardial infarction, TLR and stent thrombosis) and its components, along with target vessel revascularization (TVR) were the secondary ones. A propensity score with matching analysis to compare patients treated with BP-DES versus DP-DES was also assessed. Results From 3001 enrolled patients, after propensity score analysis 1400 patients (700 for each group) were selected. Among them, 352 had ULM disease and 1048 had non-LM bifurcations. At 16 months (12–22), rates of TLR (3.7% vs 2.9%, p = 0.22) and MACE were similar (12.3% vs. 11.6%, p = 0.74) as well as for the other endpoints. Sensitivity analysis of outcomes after a two-stents strategy, showed better outcome in term of MACE (20.4% vs 10%, p = 0.03) and TVR (12% vs 4.6%, p = 0.05) and a trend towards lower TLR in patients treated with BP-DES. Conclusion In patients with bifurcations or ULM treated with ultrathin stents BP-DES seems to perform similarly to DP-DES: the trends toward improved clinical outcomes in patients treated with the BP-DES might potentially be of value for speculating the stent choice in selected high-risk subgroups of patients at increased risk of ischemic events. Trial registration ClinicalTrials.gov Identifier: NCT03544294 . Retrospectively registered June 1, 2018
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