LES of Temporally Evolving Mixing Layers by an Eighth-Order Filter Scheme

An eighth-order filter method for a wide range of compressible flow speeds (H.C. Yee and B. Sjogreen, Proceedings of ICOSAHOM09, June 22-26, 2009, Trondheim, Norway) are employed for large eddy simulations (LES) of temporally evolving mixing layers (TML) for different convective Mach numbers (Mc) and Reynolds numbers. The high order filter method is designed for accurate and efficient simulations of shock-free compressible turbulence, turbulence with shocklets and turbulence with strong shocks with minimum tuning of scheme parameters. The value of Mc considered is for the TML range from the quasi-incompressible regime to the highly compressible supersonic regime. The three main characteristics of compressible TML (the self similarity property, compressibility effects and the presence of large-scale structure with shocklets for high Mc) are considered for the LES study. The LES results using the same scheme parameters for all studied cases agree well with experimental results of Barone et al. (2006), and published direct numerical simulations (DNS) work of Rogers & Moser (1994) and Pantano & Sarkar (2002)

Metformin overdose: A serious iatrogenic complication-Western France Poison Control Centre Data Analysis

INTRODUCTION: The prevalence of type 2 diabetes (T2D) continues to rise across the world. Metformin is still considered the "gold standard" and is, therefore, increasingly prescribed. Monitoring of metformin continues to be debated because of its association with lactic acidosis (MALA), a rare but life-threatening complication. The aim of this study was to identify the main individual characteristics associated with severe poisoning in self-poisonings and therapeutic accidents reported at the Western France Poison Control Centre (PCC). METHODS: Retrospective study of metformin poisoning from September 1999 to September 2016 at the Western France PCC recorded in the French PCC\u27s database (SICAP). The end-point was clinically high severity (mortality and/or cardiovascular shock and/or GCS ≤ 7/15). RESULTS: Of the 382 cases included, 197 concerned acute accidental exposures, 127 self-poisonings and 58 therapeutic accidents. MALA concerned 63 patients: 44 therapeutic accidents and 19 self-poisonings. High severity concerned 59 patients: 47 therapeutic accidents and 12 self-poisonings. T2D and age > 60 significantly increase the risk of high severity (OR 7.7, CI [1.54-38.41]; P = 0.013; OR 3.5, CI [1.60-7.84]; P = 0.002, respectively). CONCLUSIONS: Metformin may lead to MALA and severe poisoning in therapeutic accidents but also in self-poisoning circumstances. Among reported cases, T2D history and age >60 increase the risk of serious poisoning. Monitoring of their treatment should be taken seriously especially in the event of digestive symptoms such as diarrhoea

Prognostic Value of the Insertion/Deletion Polymorphism of the ACE Gene in Type 2 Diabetic Subjects: Results from the Non-Insulin-Dependent Diabetes, Hypertension, Microalbuminuria or Proteinuria, Cardiovascular Events, and Ramipril (DIABHYCAR), Diabete de type 2, Nephropathie et Genetique (DIAB2NEPHROGENE), and Survie, Diabete de type 2 et Genetique (SURDIAGENE) studies

OBJECTIVE—We tested whether determination of the ACE insertion/deletion polymorphism is useful for renal and cardiovascular prognoses of type 2 diabetic subjects

Growth of MnxAu1−x Films on Cu(001) and Ag(001) Single-Crystal Substrates

The growth, morphology, and structure of MnxAu1-x films on Cu(001) and Ag(001) are studied by means of low-energy electron diffraction (LEED), medium-energy electron diffraction, Auger electron spectroscopy, and scanning tunnelling microscopy. Different concentrations x from about 0.5 to 1 and thicknesses from0.2 to 12.9 ML of MnxAu1-x are examined. For several values of x, MnxAu1-x exhibits a c(2 x 2) superstructure pattern on Cu(001) when the total thickness is around or above 0.5 ML. Above 1 ML, LEED patterns of MnxAu1-x can be only observed on Ag(001), but not on Cu(001). LEED-I(V) is employed to deduce the vertical interlayer distance for as-grown and post-annealed films on Ag(001). Above 500 K, Ag from the substrate segregates into thefilms

Numerical Simulations of Microscale Gas Flows: Continuum Approach

Non

Polymorphous Si thin films from radio frequency plasmas of SiH4 diluted in Ar: A study by transmission electron microscopy and Raman spectroscopy

In this study, we present a detailed structural characterization by means of transmission electron microscopy and Raman spectroscopy of polymorphous silicon (pm-Si:H) thin films deposited using radio-frequency dust-forming plasmas of SiH4 diluted in Ar. Square-wave modulation of the plasma and gas temperature was varied to obtain films with different nanostructures. Transmission electron microscopy and electron diffraction have shown the presence of Si crystallites of around 2 nm in the pm-Si:H films, which are related to the nanoparticles formed in the plasma gas phase coming from their different growth stages, named particle nucleation and coagulation. Raman scattering has proved the role of the film nanostructure in the crystallization process induced ¿in situ¿ by laser heating

Progression of aortic stenosis after an acute myocardial infarction

Background Myocardial infarction (MI) has been shown to induce fibrotic remodelling of the mitral and tricuspid valves. It is unknown whether MI also induces pathological remodelling of the aortic valve and alters aortic stenosis (AS) progression. We thus compared AS progression after an acute MI and in patients with/without history of MI, and assessed post-MI pathobiological changes within the aortic valve leaflets in a sheep model. Methods Serial echocardiograms in human patients with AS were retrospectively analysed and compared between 3 groups: (1) acute MI at baseline (n=68), (2) prior history of MI (n=45) and (3) controls without MI (n=101). Annualised progression rates of AS severity were compared between these 3 groups. In addition, aortic valves were harvested from 15 sheep: (1) induced inferior MI (n=10) and (2) controls without MI (n=5), for biological and histological analyses. Results In humans, the acute MI, previous MI and control groups had comparable baseline AS severity. Indexed aortic valve area (AVAi) declined faster in the acute MI group compared with controls (−0.07±0.06 vs −0.04±0.04 cm²/m²/year; p=0.004). After adjustment, acute MI status was significantly associated with faster AVAi progression (mean difference: −0.013 (95% CI −0.023 to −0.003) cm²/m²/year, p=0.008). In the post-MI experimental animal model, aortic valve thickness and qualitative/quantitative expression of collagen were significantly increased compared with controls. Conclusions The results of this study suggest that AS progression is accelerated following acute MI, which could be caused by increased collagen production and thickening of the aortic valve after the ischaemic event

Admission Hyperglycemia Predicts a Worse Outcome in Stroke Patients Treated With Intravenous Thrombolysis

OBJECTIVE: Admission hyperglycemia has been associated with worse outcomes in ischemic stroke. We hypothesized that hyperglycemia (glucose >8.0 mmol/l) in the hyperacute phase would be independently associated with increased mortality, symptomatic intracerebral hemorrhage (SICH), and poor functional status at 90 days in stroke patients treated with intravenous tissue plasminogen activator (IV-tPA). RESEARCH DESIGN AND METHODS: Using data from the prospective, multicenter Canadian Alteplase for Stroke Effectiveness Study (CASES), the association between admission glucose >8.0 mmol/l and mortality, SICH, and poor functional status at 90 days (modified Rankin Scale >1) was examined. Similar analyses examining glucose as a continuous measure were conducted. RESULTS: Of 1,098 patients, 296 (27%) had admission hyperglycemia, including 18% of those without diabetes and 70% of those with diabetes. After multivariable logistic regression, admission hyperglycemia was found to be independently associated with increased risk of death (adjusted risk ratio 1.5 [95% CI 1.2-1.9]), SICH (1.69 [0.95-3.00]), and a decreased probability of a favorable outcome at 90 days (0.7 [0.5-0.9]). An incremental risk of death and SICH and unfavorable 90-day outcomes was observed with increasing admission glucose. This observation held true for patients with and without diabetes. CONCLUSIONS: In this cohort of IV-tPA-treated stroke patients, admission hyperglycemia was independently associated with increased risk of death, SICH, and poor functional status at 90 days. Treatment trials continue to be urgently needed to determine whether this is a modifiable risk factor for poor outcome

Evaluating the Effectiveness of Coagulation–Flocculation Treatment Using Aluminum Sulfate on a Polluted Surface Water Source: A Year-Long Study

\ua9 2024 by the authors.Safeguarding drinking water is a major public health and environmental concern because it is essential to human life but may contain pollutants that can cause illness or harm the environment. Therefore, continuous research is necessary to improve water treatment methods and guarantee its quality. As part of this study, the effectiveness of coagulation–flocculation treatment using aluminum sulfate (Al2(SO4)3) was evaluated on a very polluted site. Samplings were taken almost every day for a month from the polluted site, and the samples were characterized by several physicochemical properties, such as hydrogen potential (pH), electrical conductivity, turbidity, organic matter, ammonium (NH+4), phosphate (PO43−), nitrate (NO3−), nitrite (NO2−), calcium (Ca2+), magnesium (Mg2+), total hardness (TH), chloride (Cl−), bicarbonate (HCO3−), sulfate (SO42−), iron (Fe3+), manganese (Mn2+), aluminum (Al3+), potassium (K+), sodium (Na+), complete alkalimetric titration (TAC), and dry residue (DR). Then, these samples were treated with Al2(SO4)3 using the jar test method, which is a common method to determine the optimal amount of coagulant to add to the water based on its physicochemical characteristics. A mathematical model had been previously created using the support vector machine method to predict the dose of coagulant according to the parameters of temperature, pH, TAC, conductivity, and turbidity. This Al2(SO4)3 treatment step was repeated at the end of each month for a year, and a second characterization of the physicochemical parameters was carried out in order to compare them with those of the raw water. The results showed a very effective elimination of the various pollutions, with a very high rate, thus demonstrating the effectiveness of the Al2(SO4)3. The physicochemical parameters measured after the treatment showed a significant reduction in the majority of the physicochemical parameters. These results demonstrated that the coagulation–flocculation treatment with Al2(SO4)3 was very effective in eliminating the various pollutions present in the raw water. They also stress the importance of continued research in the field of water treatment to improve the quality of drinking water and protect public health and the environment