4-Quinolone fused heterocyclic ring systems by intramolecular reactions of 4-quinolone-2-carboxamides

A versatile synthetic route to new 4-quinolone-based polycyclic systems is described. TFA-catalyzed intramolecular reaction of N-unsubstituted quinolone-2-carboxylic acid amides gives structurally diverse compounds, depending on the length of the chain. Acid treatment of \u3b2-oxoamides furnishes 3H-pyrazino[1,2-a]quinoline-4,6-diones, due to the nucleophilic attack of N-1 to the carbonyl group, whereas TFA treatment of \u3b4- and \u3b5-oxoamides leads to the formation of tetracyclic compounds by a tandem heteroannulation reaction

Risk assessment of a bulk cryogenic tank: Beyond the Leak-Before-Break criterion

International audienceThe increase in the size and production capacity of air separation plants has boosted the need of developing methodologies to properly assess the risk related to major releases of liquefied gas. In this respect, the Leak-Before-Break (LBB) assessment is currently adopted to demonstrate the safety of the structures containing liquefied gas, under the assumption that the tank is always operated in nominal conditions. This assumption is questioned in this paper, which proposes a new methodology for the assessment of the risks related to cryogenic tank catastrophic rupture. The methodology provides a comprehensive understanding of the issues associated to the worst case rupture scenario: from the investigation of the causes of the undesirable operating conditions up to the analysis of the associated structural consequences, within a probabilistic framewo

Defect tolerance of a gamma titanium aluminide alloy

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Cardiac Implications of Adenotonsillar Hypertrophy and Obstructive Sleep Apnea in Pediatric Patients: A Comprehensive Systematic Review

This review investigates the relationship between pediatric obstructive sleep apnea, often associated with adenotonsillar hypertrophy, and cardiovascular health, particularly pulmonary hypertension. We conducted a comprehensive literature search using electronic databases, including Medline Pub-Med, Scopus, and the Web of Science. The study analyzed a total of 230 articles and screened 48 articles, with 20 included in the final analysis, involving 2429 children. The PRISMA flowchart visually illustrates the selection process, and the ROBINS-E and –I tools help ensure the reliability and validity of the evidence produced by these studies. These studies explored various aspects, including the severity of obstructive sleep apnea, cardiac anomalies, cardiac stress markers, risk factors for pulmonary hypertension, and the impact of adenoidectomy and tonsillectomy on cardiac function. The research found that adenotonsillar hypertrophy and obstructive sleep apnea are significant risk factors for cardiovascular complications, especially pulmonary hypertension, in children. Adenoidectomy and tonsillectomy may provide effective treatments. Following adenoidectomy in relation to obstructive sleep apnea, there appears to be a reduction in mean pulmonary artery pressure during echocardiographic examination. However, the efficacy of these procedures can vary based on the severity of obstructive sleep apnea and individual cardiac conditions. The study also identified concerns regarding data bias. The authors emphasize the need for well-designed clinical studies, including both healthy patients with adenotonsillar hypertrophy and vulnerable children with genetic disorders, to ensure that clinical decisions are based on solid scientific evidence

Direct electrification of Rh/Al2O3 washcoated SiSiC foams for methane steam reforming: An experimental and modelling study

Electrified methane steam reforming (eMSR) is a promising concept for low-carbon hydrogen production. We investigate an innovative eMSR reactor where SiSiC foams, coated with Rh/Al2O3 catalyst, act as electrical resistances to generate the reaction heat via the Joule effect. The novel system was studied at different temperatures, space velocities, operating pressures and catalyst loadings. Thanks to efficient heating, active catalyst and optimal substrate geometry, complete methane conversions were observed even at a high space velocity of 200000 Nl/h/kgcat. A specific energy demand as low as 1.24 kWh/Nm3H2, with an unprecedented energy efficiency of 81%, was achieved on a washcoated foam with catalyst density of 86.3 g/L (GHSV = 150000 Nl/h/kgcat, S/C = 4.1, ambient pressure). A mathematical model was validated against measured performance indicators and used to design an intensified eMSR unit for small scale H2 production.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/)

Approximating Weighted Duo-Preservation in Comparative Genomics

Motivated by comparative genomics, Chen et al. [9] introduced the Maximum Duo-preservation String Mapping (MDSM) problem in which we are given two strings $s_1$ and $s_2$ from the same alphabet and the goal is to find a mapping $\pi$ between them so as to maximize the number of duos preserved. A duo is any two consecutive characters in a string and it is preserved in the mapping if its two consecutive characters in $s_1$ are mapped to same two consecutive characters in $s_2$. The MDSM problem is known to be NP-hard and there are approximation algorithms for this problem [3, 5, 13], but all of them consider only the "unweighted" version of the problem in the sense that a duo from $s_1$ is preserved by mapping to any same duo in $s_2$ regardless of their positions in the respective strings. However, it is well-desired in comparative genomics to find mappings that consider preserving duos that are "closer" to each other under some distance measure [19]. In this paper, we introduce a generalized version of the problem, called the Maximum-Weight Duo-preservation String Mapping (MWDSM) problem that captures both duos-preservation and duos-distance measures in the sense that mapping a duo from $s_1$ to each preserved duo in $s_2$ has a weight, indicating the "closeness" of the two duos. The objective of the MWDSM problem is to find a mapping so as to maximize the total weight of preserved duos. In this paper, we give a polynomial-time 6-approximation algorithm for this problem.Comment: Appeared in proceedings of the 23rd International Computing and Combinatorics Conference (COCOON 2017

Mineral Acquisition and Utilization Strategy of Three Tropical Forages at Different Phosphorus and Nitrogen Supply

A glasshouse experiment was conducted to examine mineral acquisition and utilization strategies of Brachiaria decumbens (BD), Brachiaria brizantha (BB) and Panicum maximum (PM). The plants were grown under nine treatments resulted from the combination of three levels of phosphorus (0, 25 and 50 kgP/ha) and three levels of nitrogen (25, 150 and 300 kgN/ha). BD showed the lowest value of root weight and root length per pot, but the highest efficiency of P and N uptake (P and N uptake mg / unit root weight g). On the other hand, PM showed lower mineral uptake efficiency, but the highest mineral use efficiency (dry matter production g / absorbed P and N mg). Moreover, total P and N uptake in BB was the highest, and this seems to be achieved by the multiplicative effect of moderate mineral uptake efficiency and the moderate size of the root system

Impact of Hanging Motionless in Harness on Respiratory and Blood Pressure Reflex Modulation in Mountain Climbers

Harness hang syncope (HHS) is a risk that specifically affects safety of harness users in mountain climbing. Aims: To evaluate individual patterns of breathing resulting from deranged cardiovascular reflexes triggering a syncopal event when a mismatch between cerebral O2 demand and supply is present. Results: Forty healthy participants [aged 39.1 (8.2) years] were enrolled in a motionless suspension test while hanging in harness. Respiratory gas exchange values were analyzed to assess the pattern of breathing (EpInWel, respiratory elastic power) and cardiovascular parameters were monitored (BP, blood pressure). Four participants experienced HHS after 30.0 (7.6) minutes, with an early manifestation of loss of control of both a sustainable EpInWel and BP, starting after 10-12 minutes. Among the other participants, two different reactions were observed during suspension: (1) group G1 tolerated 32.7 (11.4) minutes of suspension by a favorable adaptation of the EpInWel and BP parameters and (2) group G2 showed significantly shorter time of suspension 24.0 (10.4) minutes with unfavorable increase in EpInWel and BP. Conclusions: Greater resistance to HHS occurs in people developing less marked fluctuations of both respiratory and cardiovascular reflex responses. Conversely, wider fluctuations both in control of EpInWel and BP were observed in the event of decreased suspension tolerance or in syncopal events

Effects of Fertilization and Legume Introduction on the Forage Production of \u3ci\u3eBrachiaria decumbens\u3c/i\u3e Pastures

A grazing experiment was conducted to examine the effects of P and K fertilization and legume introduction on the forage production of Brachiaria decumbens (BD) pastures. Amount of biomass, dry matter production and forage quality were evaluated on BD pastures where three treatments were applied: without maintenance fertilizer (BD-N), with maintenance fertilizer (BD-F), and BD and Stylosanthes guianensis cv. Mineirao (SG) mixture with maintenance fertilizer (BD-FL). The fertilizer application increased an annual average of biomass and the contents of P and K in the leaves. On the other hand, the legume introduction had a positive influence on crude protein and digestibility, and the effect was obvious in the rainy season. The introduction of legume also increased litter decomposition constants, although the difference in the constants among the treatments was not significant