Soundness Discrimination in Ferrite Ductile Irons Through Tensile Data Analysis

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Approche min-max pour la recherche d'un chemin optimal

Nous présentons une approche permettant de retrouver la structure d'objets arborescents dans une image en niveau de gris. Notre méthode s'appuie sur une extension de la recherche du chemin d'énergie minimale entre deux sites. Dans le but d'améliorer les résultats obtenus dans le cas d'objets très incurvés, nous proposons de modifier la fonction d'énergie de manière à la rendre indépendante de la longueur du chemin. Nous montrons ensuite l'équivalence entre la formulation min-max que nous proposons et une correction du potentiel en chaque point. Enfin, nous proposons une formulation globale de l'énergie qui consiste à pénaliser les potentiels supérieurs au potentiel min-max. L'approche sera illustrée par des résultats obtenus sur des images aériennes

Anopheles darlingi polytene chromosomes: revised maps including newly described inversions and evidence for population structure in Manaus

Salivary gland polytene chromosomes of 4th instar Anopheles darlingi Root were examined from multiple locations in the Brazilian Amazon. Minor modifications were made to existing polytene photomaps. These included changes to the breakpoint positions of several previously described paracentric inversions and descriptions of four new paracentric inversions, two on the right arm of chromosome 3 and two on the left arm of chromosome 3 that were found in multiple locations. A total of 18 inversions on the X (n = 1) chromosome, chromosome 2 (n = 7) and 3 (n = 11) were scored for 83 individuals from Manaus, Macapá and Porto Velho municipalities. The frequency of 2Ra inversion karyotypes in Manaus shows significant deficiency of heterozygotes (p < 0.0009). No significant linkage disequilibrium was found between inversions on chromosome 2 and 3. We hypothesize that at least two sympatric subpopulations exist within the An. darlingi population at Manaus based on inversion frequencies

Differentials of fertility in North and South Gondar zones, northwest Ethiopia: A comparative cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Ethiopia is one of the most densely populated countries in Africa with an estimated population of 77.1 million in mid-2007. Uncontrolled fertility has adversely influenced the socio-economic, demographic and environmental situations of the country. It is one of the largest and poorest countries that, even in the midst of crisis, has maintained high levels of fertility. This study was aimed at investigating the most important factors influencing fertility behavior in Northwest Ethiopia.</p> <p>Methods</p> <p>A comparative cross-sectional study which included 2424 women aged 25 years and above was undertaken in the Amhara region of Northwest Ethiopia. The study subjects were grouped into high fertile and low fertile categories. There were 1011 and 1413 women in the high and low fertile groups, respectively. A multi-stage cluster sampling stratified by place of residence was employed to select the required study subjects. Both bivariate and multivariate logistic regression techniques were used to analyze the data.</p> <p>Results</p> <p>Among the 25 variables considered in this study, only 9 of them were found significantly and independently associated with the level of fertility. Women with at least secondary education were at a lower risk of high fertility with OR = 0.37 (95% CI: 0.21 to 0.64) compared to those with no formal education. However, women with primary education did not show any significant difference when compared with the same baseline group. Age at first marriage was inversely associated with the number of children ever born alive. Place of residence, household expenditure, number of children who have died, attitude towards using contraceptives, women's knowledge on the safe period, and current marital status were the other variables that showed significant associations with the level of fertility.</p> <p>Conclusion</p> <p>Female education beyond the primary level, reduced infant and child mortality, delayed marriage and correct knowledge on the safe period during the menstrual cycle were amongst the main factors that had a bearing on high fertility.</p

Dolutegravir twice-daily dosing in children with HIV-associated tuberculosis: a pharmacokinetic and safety study within the open-label, multicentre, randomised, non-inferiority ODYSSEY trial

Background: Children with HIV-associated tuberculosis (TB) have few antiretroviral therapy (ART) options. We aimed to evaluate the safety and pharmacokinetics of dolutegravir twice-daily dosing in children receiving rifampicin for HIV-associated TB. Methods: We nested a two-period, fixed-order pharmacokinetic substudy within the open-label, multicentre, randomised, controlled, non-inferiority ODYSSEY trial at research centres in South Africa, Uganda, and Zimbabwe. Children (aged 4 weeks to <18 years) with HIV-associated TB who were receiving rifampicin and twice-daily dolutegravir were eligible for inclusion. We did a 12-h pharmacokinetic profile on rifampicin and twice-daily dolutegravir and a 24-h profile on once-daily dolutegravir. Geometric mean ratios for trough plasma concentration (Ctrough), area under the plasma concentration time curve from 0 h to 24 h after dosing (AUC0–24 h), and maximum plasma concentration (Cmax) were used to compare dolutegravir concentrations between substudy days. We assessed rifampicin Cmax on the first substudy day. All children within ODYSSEY with HIV-associated TB who received rifampicin and twice-daily dolutegravir were included in the safety analysis. We described adverse events reported from starting twice-daily dolutegravir to 30 days after returning to once-daily dolutegravir. This trial is registered with ClinicalTrials.gov (NCT02259127), EudraCT (2014–002632-14), and the ISRCTN registry (ISRCTN91737921). Findings: Between Sept 20, 2016, and June 28, 2021, 37 children with HIV-associated TB (median age 11·9 years [range 0·4–17·6], 19 [51%] were female and 18 [49%] were male, 36 [97%] in Africa and one [3%] in Thailand) received rifampicin with twice-daily dolutegravir and were included in the safety analysis. 20 (54%) of 37 children enrolled in the pharmacokinetic substudy, 14 of whom contributed at least one evaluable pharmacokinetic curve for dolutegravir, including 12 who had within-participant comparisons. Geometric mean ratios for rifampicin and twice-daily dolutegravir versus once-daily dolutegravir were 1·51 (90% CI 1·08–2·11) for Ctrough, 1·23 (0·99–1·53) for AUC0–24 h, and 0·94 (0·76–1·16) for Cmax. Individual dolutegravir Ctrough concentrations were higher than the 90% effective concentration (ie, 0·32 mg/L) in all children receiving rifampicin and twice-daily dolutegravir. Of 18 children with evaluable rifampicin concentrations, 15 (83%) had a Cmax of less than the optimal target concentration of 8 mg/L. Rifampicin geometric mean Cmax was 5·1 mg/L (coefficient of variation 71%). During a median follow-up of 31 weeks (IQR 30–40), 15 grade 3 or higher adverse events occurred among 11 (30%) of 37 children, ten serious adverse events occurred among eight (22%) children, including two deaths (one tuberculosis-related death, one death due to traumatic injury); no adverse events, including deaths, were considered related to dolutegravir. Interpretation: Twice-daily dolutegravir was shown to be safe and sufficient to overcome the rifampicin enzyme-inducing effect in children, and could provide a practical ART option for children with HIV-associated TB

Neuropsychiatric manifestations and sleep disturbances with dolutegravir-based antiretroviral therapy versus standard of care in children and adolescents: a secondary analysis of the ODYSSEY trial

BACKGROUND: Cohort studies in adults with HIV showed that dolutegravir was associated with neuropsychiatric adverse events and sleep problems, yet data are scarce in children and adolescents. We aimed to evaluate neuropsychiatric manifestations in children and adolescents treated with dolutegravir-based treatment versus alternative antiretroviral therapy. METHODS: This is a secondary analysis of ODYSSEY, an open-label, multicentre, randomised, non-inferiority trial, in which adolescents and children initiating first-line or second-line antiretroviral therapy were randomly assigned 1:1 to dolutegravir-based treatment or standard-of-care treatment. We assessed neuropsychiatric adverse events (reported by clinicians) and responses to the mood and sleep questionnaires (reported by the participant or their carer) in both groups. We compared the proportions of patients with neuropsychiatric adverse events (neurological, psychiatric, and total), time to first neuropsychiatric adverse event, and participant-reported responses to questionnaires capturing issues with mood, suicidal thoughts, and sleep problems. FINDINGS: Between Sept 20, 2016, and June 22, 2018, 707 participants were enrolled, of whom 345 (49%) were female and 362 (51%) were male, and 623 (88%) were Black-African. Of 707 participants, 350 (50%) were randomly assigned to dolutegravir-based antiretroviral therapy and 357 (50%) to non-dolutegravir-based standard-of-care. 311 (44%) of 707 participants started first-line antiretroviral therapy (ODYSSEY-A; 145 [92%] of 157 participants had efavirenz-based therapy in the standard-of-care group), and 396 (56%) of 707 started second-line therapy (ODYSSEY-B; 195 [98%] of 200 had protease inhibitor-based therapy in the standard-of-care group). During follow-up (median 142 weeks, IQR 124–159), 23 participants had 31 neuropsychiatric adverse events (15 in the dolutegravir group and eight in the standard-of-care group; difference in proportion of participants with ≥1 event p=0·13). 11 participants had one or more neurological events (six and five; p=0·74) and 14 participants had one or more psychiatric events (ten and four; p=0·097). Among 14 participants with psychiatric events, eight participants in the dolutegravir group and four in standard-of-care group had suicidal ideation or behaviour. More participants in the dolutegravir group than the standard-of-care group reported symptoms of self-harm (eight vs one; p=0·025), life not worth living (17 vs five; p=0·0091), or suicidal thoughts (13 vs none; p=0·0006) at one or more follow-up visits. Most reports were transient. There were no differences by treatment group in low mood or feeling sad, problems concentrating, feeling worried or feeling angry or aggressive, sleep problems, or sleep quality. INTERPRETATION: The numbers of neuropsychiatric adverse events and reported neuropsychiatric symptoms were low. However, numerically more participants had psychiatric events and reported suicidality ideation in the dolutegravir group than the standard-of-care group. These differences should be interpreted with caution in an open-label trial. Clinicians and policy makers should consider including suicidality screening of children or adolescents receiving dolutegravir

Mitral valve prolapse: Gender differences in evaluation and management

Mitral valve prolapse is a common clinical disorder that affects approximately 3-4% of the adult population. Prolapse occurs more commonly in women and has been associated with a variety of cardiac complications including mitral regurgitation, endocarditis, arrhythmias, and sudden death, as well as noncardiac manifestations including stroke. Much of our earlier understanding has been influenced by significant referral biases and lack of controlled studies. Our understanding of mitral prolapse has evolved considerably since the initial descriptions nearly 3 decades ago. This review on the current knowledge regarding diagnosis and management of primary mitral valve prolapse focuses on gender-related issues that influence clinical presentation, prognosis, and therapeutic strategies

Novel approach based on tensile strain hardening analysis to assess the integrity of an Al alloy produced through High-Pressure Die Casting

The analysis of the structural integrity of components in Al alloys produced by High Pressure Die Casting (HPDC) is paramount for identifying a correlation between process-microstructure-mechanical properties, a correlation that allows to classify the quality process parameters, and identify potential application areas. The tensile test represents the simplest method to pursue this aim, and the tensile strain hardening analysis seems to be capable of providing interesting correlations. In fact, an innovative method based on the analysis of strain hardening through the formalism of the constitutive equation of Voce has provided interesting results in other foundry materials, such as spheroidal cast irons. In this work, we report the results of the application of the innovative method to an Al alloy produced by HPDC in two components having two different geometries. One geometry is that of a round tensile specimen, adopted as a reference since it has an "ideal" microstructure according to the PD CEN/TR 16748:2014 standard, and a second one is a real U shape geometry. The innovative procedure has uniquely identified that the Al alloy with "ideal" microstructure has better microstructural integrity of the material from the U geometry casting, demonstrating that the innovative procedure can also be used successfully for Al alloys produced by HPDC

Assessment of the austempering process evolution through tensile testing

The capability of a constituent equation based on physical parameters to relate the plastic behavior with the microstructure was investigated in Austempered Ductile cast Iron 1050 (ADI 1050) to assess the stability of the residual austenite produced during austempering to obtain the optimum ausferritic microstructure. The critical time-window to interrupt austempering is that when the austempering transformation has come to saturation and an austenitic fraction characterized by maximum stability is produced (Stage I of austempering), before the precipitation of detrimental carbides e' takes place (Stage II of austempering). The ADI 1050 was quenched after different times during austempering, and the quenched samples were deformed through tensile testing at room temperature. The trends of ultimate tensile strengths Rm and elongations to rupture eR were consistent with the observed microstructure, and for very long austempering times a significant reduction in ductility was found, which could be rationalized as the occurring of e' precipitation. However, the Rm and eR data trends showed a large dispersion, so that it was impossible to identify unambiguously the optimum timewindow of austempering. For this reason, tensile flow curves were modelled with a constituent equation based on physical parameters related to the microstructure of materials. These parameters showed a lower dispersion with smooth trends against the austempering times, so they allowed to determine the critical time-window to stop the austempering industrial process for the best ausferrite