A catalytic asymmetric procedure for the 1,3-dipolar cycloaddition of (Ε)-β-phenylsulfonyl enones with azomethine ylides to provide highly functionalized pyrrolidine derivatives is described. In the ...presence of chiral CuI-Segphos catalysts the aducts were obtained with high regio-, diastereo-, and enantioselectivity. Interestingly, a switch from endo to exo selectivity was observed when Segphos or DTBM-Segphos ligand was used.
Potential exposures are those that may occur as a result of unanticipated operational performance or accidents. Potential exposure situations are probabilistic in nature because they depend on ...uncertain events such as equipment failure, operator errors or external initiators beyond the control of the operator. Consequently, there may exist a range of possible radiological impacts that need to be considered. In this paper a Level 3 Probabilistic Safety Assessment (PSA) for a hypothetical scenario relevant to Innovative Nuclear Energy Systems (INS) was conducted using computer code MACCS (MELCOR Accident Consequence Code Systems). The acceptability of an INS was analyzed taking into account the general requirement that relocation or evacuation measures must not be necessary beyond the site boundary. In addition, deterministic modeling of the accident consequences for the critical meteorological conditions was carried out using the JRODOS decision support system (Real-time On-line Decision Support system for off-site emergency management in Europe). The approach used for dose and risk assessment from potential exposure of accidental releases and their comparison with acceptance criteria are presented. The methodology described can be used as input to the licensing procedure and engineering design considerations to help satisfy relevant health and environmental impact criteria for fission or fusion nuclear installations.
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•PSA Level-3 based on WinMACCS code is carried out for accidental release.•Family curves of percentiles for radiation exposure doses are constructed.•Risk indicators for potential exposure are defined.•Using of risk acceptance curve criteria is proposed for decision making process.
Designing and manufacturing transformers often involves variations in heights and thicknesses of windings. However, such geometric asymmetry introduces a significant impact on the magnitude of stray ...transformer losses. This study examines the effects of asymmetric coils on the generation of stray losses within core clamps and transformer tank walls. A model has been introduced to ascertain the dispersion magnetic field’s value at a specific distance from the coil. The analysis extends to characterising the dispersion magnetic field reaching the tank walls by using electromagnetic simulation by a finite element method. It explores strategies to diminish stray losses, including the placement of magnetic shunts as protective shields for the tank walls. It delves into the efficacy of employing a transformer shell-type configuration to mitigate the magnetic dispersion field. The findings revealed that achieving greater symmetry in transformer coils can minimise stray losses. Specifically, the incorporation of magnetic shunts has the potential to reduce additional losses by 40%, while the adoption of a shell-type configuration alone can lead to a 14% reduction. This work provides valuable insights into optimising transformer designs, contributes a user-friendly tool for estimating additional tank losses, thereby enhancing the knowledge base for transformer manufacturers.
Dynamic mathematical models could be beneficial for understanding and simulating processes to achieve an optimal operation. The optimum, however, could depend on several variables that can be ...conflicting. In this regard, Dynamic Multi-objective Optimization (DMO) is necessary for the trade-off between several objectives. This work aims at proposing a DMO as a control strategy integrating two optimization problems. The objective is to maximize the yield and productivity of the biomethanation processes by modifying the inlet liquid and injected gas flowrates. First, multi-objective optimization was applied. Three Pareto optimal points were selected to develop five cases in dynamic optimization. Case 1 corresponded to experimental data. Cases 2, 3, and 4 considered as objectives the maximum productivity, maximum productivity and yield, and maximum yield, respectively. Case 5 was performed to assess a switch between objectives. For case 3, the yield decreased to 0.97 times, while the productivity increased 3.26 times with respect to case 1. The injected gas flowrate ranged from 2.69 to 8.43 ?? 3 ?? , and the inlet liquid flowrate reached an approximate value of 7.0×10-3 ?? 3 ?? . These results showed the feasibility and good efficiency of the proposed methodology.
We report the effect of the Sesquiterpene Lactones Ambrosin, Incomptine B and Glaucolide E against seven strains of Trypanosoma cruzi, the etiological agent of Chagas Disease. These compounds were ...isolated from Parthenium hysterophorus, Decachaeta incompta, and Vernonia liatroides, respectively. We evaluated by flow cytometry the viability of epimastigotes. Ambrosin was the most effective, then Incomptine B, and Glaucolide E (IC50 = 67.1, 123.7, and 215.1 μM, respectively). These compounds were more potent than the drugs Benznidazole (IC50 > 400 μM) and Nifurtimox (IC50 = 199.7 to >400 μM). Toxicity to mammalian Vero and Jurkat cells was also determined in vitro. All the compounds had a poor selective index (0.003–1.859). Toxicoinformatics is useful to forecast in silico toxicological and pharmacokinetic properties. Ambrosin and Incomptine B may not possess mutagenic, tumorigenic, or reproductive effects. Glaucolide E could possess a low mutagenic and high tumorigenic effects, and probably target the Amine Oxidase A, Prostaglandin and G/H Synthase I. Interestingly, Ambrosin, Incomptine B and Glaucolide E, comply with Lipinsky Rule of Five, indicating a suitable pharmacokinetic profile. Ambrosin and Incomptine B possess high trypanocidal activity, and pharmaceutical properties suitable for development; however, their safety profile should be optimized by structural modifications.
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•Sesquiterpene Lactones Ambrosin, Incomptine B and Glaucolide E have trypanocidal activity.•Ambrosin and Incomptine B possess pharmaceutical properties suitable for development.•The safety profile of Ambrosin and Incomptine B should be optimized before their use as novel trypanocidal drugs.
We aimed to review the available evidence on the association between vitamin B12, folate, and homocysteine levels with worse outcomes among COVID-19 patients.
The search was carried out in ten ...databases simultaneously run on 10 May 2023, without language restrictions. We included cross-sectional, case-control, and cohort studies. The random-effects meta-analysis was performed using the Sidik-Jonkman method and corrected 95% confidence intervals using the truncated Knapp-Hartung standard errors. Standardized mean difference and 95% CI was used as the measure effect size.
Thirteen articles were included in this review (
= 2134). Patients with COVID-19 who did not survive had the highest serum vitamin B12 values (SMD: 1.05; 95% CI: 0.31-1.78;
= 0.01,
= 91.22%). In contrast, low serum folate values were associated with patients with severe COVID-19 (SMD: -0.77; 95% CI: -1.35 to -0.19;
= 0.02,
= 59.09%). The remaining tested differences did not yield significant results.
Elevated serum levels of vitamin B12 were associated with higher mortality in patients with COVID-19. Severe cases of COVID-19 were associated with low serum folate levels. Future studies should incorporate a larger sample size.
Na
/K
-ATPase is an essential transmembrane enzyme found in all mammalian cells with critical functions for cell ion homeostasis. The inhibition of this enzyme by several cardiotonic steroids (CTS) ...has been associated with the cytotoxic effect on cancer cell lines of phytochemicals such as ouabain and digitoxin. This study evaluated the inhibitory capacity of cardenolides calotropin and corotoxigenin 3-O-glucopyranoside (C3OG) from
over the Na
/K
-ATPase activity
and
. The inhibitory assays showed that calotropin and C3OG decreased the Na
/K
-ATPase activity with IC
values of 0.27 and 0.87 μM, respectively. Furthermore, the molecules presented an uncompetitive inhibition on Na
/K
-ATPase activity, with K
values of 0.2 μM to calotropin and 0.5 μM to C3OG. Furthermore, the molecular modeling indicated that calotropin and C3OG might interact with the Thr
and Gln
residues, considered essential to the interaction with the Na
/K
-ATPase. Besides, these cardenolides can interact with amino acid residues such as Phe
, Leu
, and Ala
, to establish hydrophobic interactions on the binding site. Considering the results, these provide novel evidence about the mechanism of action of cardenolides from
, proposing that C3OG is a novel cardenolide that deserves further consideration for
cellular antiproliferative assays and
studies as an anticancer molecule.
•Before 2010 NORM waste is managed as non-radioactive, disposed in landfills.•After 2010 radiological impact of the management of NORM wastes must be assessed.•Quantities that can be disposed in ...hazardous or non-hazardous landfills are given.•Uncertainty analysis is included to provide consistency to the calculations.
Naturally Occurring Radioactive Materials (NORM) wastes are generated in huge quantities in several industries and their management has been carried out under considerations of industrial non-radioactive wastes, before the concern on the radioactivity content was included in the legislation. Therefore these wastes were conditioned using conventional methods and the waste disposals were designed to isolate toxic elements from the environment for long periods of time. Spanish regulation for these conventional toxic waste disposals includes conditions that assure adequate isolation to minimize the impact of the wastes to the environment in present and future conditions.
After 1996 the radiological impact of the management of NORM wastes is considered and all the aspects related with natural radiations and the radiological control regarding the management of residues from NORM industries were developed in the new regulation. One option to be assessed is the disposal of NORM wastes in hazardous and non-hazardous waste disposals, as was done before this new regulation.
This work analyses the management of NORM wastes in these landfills to derive the masses that can be disposed without considerable radiological impact. Generic dose assessments were carried out under highly conservative hypothesis and a discussion on the uncertainty and variability sources was included to provide consistency to the calculations.
This study evaluated the impact of supplementing ZH in combination with D3 on the growth performance, energy efficiency, carcass traits, and meat quality of feedlot lambs. Thirty-two Dorper × ...Katahdin cross lambs (37.3 ± 5.72 kg) were utilized in a 29 d experiment in a completely randomized block design with a 2 × 2 factorial structure consisting of two levels of ZH for 26 d (0 and 0.20 mg/kg PV−1) and two levels of D3 for 7 d (0 and 1.5 × 106 IU/d−1). ZH improved (p ≤ 0.05) the average daily gain (ADG) and feed efficiency by 9.9% and 17.8%, respectively, as well as hot carcass weight (HCW) and dressing carcass by 4.3% and 2.6%, respectively. (p ≤ 0.03). However, ZH increased (p < 0.01) muscle pH and Warner–Bratzler shear force (WBSF) (2.5 and 23.0%, respectively). D3 supplementation negatively affected (p ≤ 0.02) dry matter intake (DMI) (last 7 d) and ADG by 15.7% and 18.1%. On the other hand, D3 improved the pH of the longissimus thoracis muscle by 1.7% (p = 0.03) without affecting WBSF. When D3 was supplemented in combination with ZH, it was observed that meat quality was improved by reducing muscle pH compared to lambs treated only with ZH. However, D3 did not improve the meat tenderness negatively affected by ZH supplementation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
► Seasonal effect on Sonoran propolis (composition and biology activity) was studied. ► Seasonality did not significantly change the chemical composition of propolis. ► Season had an important effect ...on the antiproliferative activity of propolis. ► Spring propolis showed the highest inhibitory effect on the growth of cancer cells.
Propolis is widely used as a folk medicine and as a constituent of health foods in many parts of the world. The main purpose of this study was to evaluate the seasonal effect on the chemical composition and biological activities (antiproliferative and antioxidant activities) of Sonoran propolis (Mexico). Propolis was collected during all four seasons of the year and chemical composition, antiproliferative, and free-radical scavenging activities of collected propolis were evaluated by HPLC, MTT, and DPPH assays, respectively. The relative abundance of the main chemical constituents of propolis was similar in all propolis samples analysed. In contrast, significant differences were observed in their antiproliferative activity in the B-cell lymphoma cancer cell line M12.C3.F6. Propolis collected in the spring showed the highest inhibitory effect on the growth of cancer cells. All propolis samples had weak free-radical scavenging activity. Our results indicate that season had a significant effect on the antiproliferative properties of Sonoran propolis.
