Progressive Collapse Resistance of Steel Frames with Reduced Beam Sections and Web Openings

Progressive collapse represents a critical failure scenario in steel moment-resisting frames, especially when beam sections are intentionally weakened through flange cuts or web openings. While previous studies reported that circular openings were the most effective configuration among various shapes, the present study investigates whether semi-circular openings, when combined with reduced beam sections (RBS), can provide superior performance. A finite element model was developed in ABAQUS/Explicit v2016 and validated against experimental results to ensure reliability. Parametric analyses considered both circular and semi-circular openings with diameters of 80 mm and 110 mm, placed at various distances from the RBS centerline (L = 0, 65, 140, and 180 mm). The results show that openings located too close to the RBS zone (L = 0 mm and L = 65 mm) significantlyreduced strength and suppressed catenary action. Conversely, larger spacings (L = 140 mm and L = 180 mm) enhanced load capacity and ductility by promoting stress redistribution. Importantly, semi-circular openings consistently outperformed circular ones in the present investigation. In particular, the SC3-140-110 specimen achieved the highest peak load (248.7 kN) and the strongest catenary action contribution (227.6 kN), demonstrating superior robustness against progressive collapse. These findings highlight the technical advantage of semi-circular openings as an effective detailing strategy for improving the collapse resistance of steel moment frames

Axial behavior and stability of built-up cold-formed steel columns with and without concrete infill:Experimental and numerical investigation

In recent years, cold-formed steel (CFS) built-up sections have gained a lot of attention in construction. This is mainly because of their structural efficiency and the design advantages they offer. They provide better load-bearing strength and show greater resistance to elastic instability. This study looks at both experimental and numerical analysis of built-up CFS columns. The columns were formed by joining two C-sections in different ways: back-to-back, face-to-face, and box arrangements. Each type was tested with different slenderness ratios. For the experiments, the back-to-back and box sections were connected using two rows of rivets. The face-to-face sections, on the other hand, were joined by welding. In order to improve axial strength and overall stability, all column samples were filled with ordinary concrete, conforming to class C25/30. The numerical modeling was done in ABAQUS to study the mechanical behavior of the columns. This helped in understanding how different joining methods affect their axial compression performance. Analytical checks were also carried out using Eurocode 3 for hollow sections and Eurocode 4 for concrete-filled sections. The role of concrete confinement was examined as well, following American Concrete Institute (ACI) guidelines, for both face-to-face and box-shaped columns. The numerical results matched closely with the experimental findings, with variations of less than 5%. The study identified key failure modes such as local buckling and distortional buckling. It highlighted how section shape, type of connection, and concrete infill all play a major role in improving the strength of built-up CFS columns

Incorporation of tocopherol-rich extracts from mushroom mycelia into yogurt

Consumers are well-informed about food additives and it is likely that they prefer natural additives over their synthetic analogues. Antioxidants represent a major class of food preservatives, among which tocopherols stand out as one of the most important examples. Interestingly, these compounds are present in relevant amounts in the mycelia of in vitro cultured mushrooms. Accordingly, the mycelia from Ganoderma lucidum, Pleurotus ostreatus and Pleurotus eryngii were used as alternative sources of tocopherols. These extracts were incorporated into different yogurt formulations, which were further compared among each other and with yogurts containing commercial α-tocopherol (E307), regarding their nutritional parameters, fatty acid profile and antioxidant activity. The proposed approach was validated as an effective functionalization strategy, particularly in the case of the G. lucidum mycelium, which showed the highest antioxidant potential, most likely as a result of its tocopherol profile. Furthermore, yogurts prepared with each mycelium extract allowed maintaining the nutritional properties observed in the “blank” yogurt formulation.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), L. Barros and J. Barreira contracts. This work is funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE and Project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®.info:eu-repo/semantics/publishedVersio

Analysis of breast milk fatty acid composition using dried milk samples.

BACKGROUND: The effect of breast milk fatty acid (FA) composition, particularly levels of docosahexaenoic acid (DHA), on infant health outcomes is unclear. Part of the reason for this is difficulties in collecting, storing and shipping milk samples to the laboratory. Here we report the validation of a dried milk spot (DMS) system to measure FA composition to help overcome these obstacles. Milk FA were measured by gas chromatography and reported as percent of total FA; the FA of primary interest in this study were DHA and industrially produced trans FA (iTFA). Experiments were carried out using pooled milk samples from US (n = 5) and Malawian women (n = 50). Experiments compared liquid vs. DMS samples (n = 55), assessed stability of FA composition under different storage conditions (n = 5), and compared the results from two different labs using the same methods (n = 5). RESULTS: Both % DHA and % iTFA levels in liquid and DMS samples were strongly correlated (R(2) = 0.99 and 0.99, respectively, P < 0.0001). The % DHA in DMS samples was stable for up to four weeks at room temperature and up to three years at -80 °C; only slight deviations from the acceptable range of variability (±15 %) occurred in the 4 °C and -20 °C conditions for % DHA. The % iTFA was stable under all conditions. All % DHA and % iTFA were within 15 % of the referent when analyzed in two laboratories. CONCLUSIONS: Valid FA composition values can be obtained from DMS samples using this robust collection and transport system which should facilitate studies of the role of milk FA composition in infant development

Pleurotus species as a source of bio-preservatives

Mushrooms are consumed worldwide not only as a part of the normal diet, but also as a delicacy due to their highly desirable taste and aroma. In addition to their nutritional value, mushrooms have been considered functional foods [1] and even as adjuvants in some therapies, namely chemotherapy [2]. This is because they are natural matrices rich in bioactive molecules, such as phenolic compounds, tocopherols, ascorbic acid, or carotenoids. In particular, tocopherols are powerful antioxidants that can be explored as natural food preservatives, in order to replace the widely used synthetic counterparts. With these aspects in mind, and given the evidence that the in vitro culture of mushrooms promotes the production of tocopherols [3], the present work aimed to sub-culture two different mushroom species by in vitro techniques, in order to enhance the production of tocopherols, and use the mycelium as sources of preservative ingredients for foodstuff. The species chosen for the study were two of the most consumed species worldwide, Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm. and Pleurotus eryngii (DC.) Quél. Firstly, both mushroom species were cultivated in different culture media (i.e., MMN complete, MMN incomplete and PDA), in order to optimize the ideal growth conditions. Since the best growth was obtained on PDA medium, both species were cultivated in PDB liquid medium, in order to obtain the amount of biomass required for the assays. After a period of approximately five weeks, the mycelia were recovered, freeze-dried and stored until further analyses. The tocopherols content was evaluated by high performance liquid chromatography coupled with a fluorescence detector. A formulation enriched in tocopherols will be prepared by extraction from the mycelium and further incorporated in cakes. Its preservative capacity will be assessed, through the evaluation of the antioxidant and antimicrobial properties before and after incorporation in the foodstuff. The results will be compared with commercial available and used preservatives (i.e., ascorbic acid- natural antioxidant and potassium sorbate- synthetic preservative).info:eu-repo/semantics/publishedVersio

A New Zn(II) Metal Hybrid Material of 5-Nitrobenzimidazolium Organic Cation (C7H6N3O2)2[ZnCl4]: Elaboration, Structure, Hirshfeld Surface, Spectroscopic, Molecular Docking Analysis, Electric and Dielectric Properties

The slow solvent evaporation approach was used to create a single crystal of (CHNO)[ZnCl] at room temperature. Our compound has been investigated by single-crystal XRD which declares that the complex crystallizes in the monoclinic crystallographic system with the P2/c as a space group. The molecular arrangement of the compound can be described by slightly distorted tetrahedral ZnCl anionic entities and 5-nitrobenzimidazolium as cations, linked together by different non-covalent interaction types (H-bonds, Cl…Cl, π…π and C–H…π). Hirshfeld’s surface study allows us to identify that the dominant contacts in the crystal building are H…Cl/Cl…H contacts (37.3%). FT-IR method was used to identify the different groups in (CHNO)[ZnCl]. Furthermore, impedance spectroscopy analysis in 393 ≤ T ≤ 438 K shows that the temperature dependence of DC conductivity follows Arrhenius’ law. The frequency–temperature dependence of AC conductivity for the studied sample shows one region (E = 2.75 eV). In order to determine modes of interactions of compound with double stranded DNA, molecular docking simulations were performed at molecular level

Validation of a direct-to-PCR COVID-19 detection protocol utilizing mechanical homogenization: a model for reducing resources needed for accurate testing

Efficient and effective viral detection methodologies are a critical piece in the global response to COVID-19, with PCR-based nasopharyngeal and oropharyngeal swab testing serving as the current gold standard. With over 100 million confirmed cases globally, the supply chains supporting these PCR testing efforts are under a tremendous amount of stress, driving the need for innovative and accurate diagnostic solutions. Herein, the utility of a direct-to-PCR method of SARS-CoV-2 detection grounded in mechanical homogenization is examined for reducing resources needed for testing while maintaining a comparable sensitivity to the current gold standard workflow of nasopharyngeal and oropharyngeal swab testing. In a head-to-head comparison of 30 patient samples, this initial clinical validation study of the proposed homogenization-based workflow demonstrated significant agreeability with the current extraction-based method utilized while cutting the total resources needed in half

Characterising protective immune responses to SARS-CoV-2 in urban and rural Malawi between February 2021 and April 2022

SARS-CoV-2 transmission in Malawi remains unclear due to high proportions of mild/asymptomatic infections and limited diagnostics. Existing seroprevalence studies in Malawi have primarily used convenience samples and enzyme-linked immunosorbent assays (ELISAs). We assessed SARSCoV-2 neutralisation in a longitudinal Malawian population-based cohort, assessing protective immunity post-infection and vaccination. Sera were obtained from rural (Karonga, n = 958) and urban (Lilongwe, n = 918) based participants at three-monthly intervals (February 2021-April 2022). Neutralising antibodies against SARS-CoV-2 were measured using human immunodeficiency (HIV)based pseudotype assays in HIV-uninfected participants, and vesicular stomatitis virus-based assays in HIV-infected participants and an HIV-uninfected subset. Nucleocapsid ELISAs identified vaccinated participants also infected. SARS-CoV-2 neutralisation profiles increased in complexity over time from rising vaccination coverage and emerging variants. Neutralising antibody prevalence was higher in Lilongwe than Karonga (68.1% (CI 63.5–72.4) vs. 45.4% (CI 41.6–49.3), Survey 4). Hybrid immune and solely vaccinated participants exhibited higher titres than those solely infected. Children &lt; 15 years had the lowest neutralising antibody titres among infected (not vaccinated) participants. People living with HIV had lower neutralising responses than those HIV-uninfected, particularly post vaccination. We therefore recommend surveillance of children and people living with HIV as low neutralisation responses increase reinfection risk. COVID-19 vaccination should be prioritised for HIV-infected individuals

New records of rarely reported species in the Mediterranean Sea (July 2023)

This Collective Article presents new information about the occurrence of 23 marine taxa that belong to five Phyla: two Chlorophyta, one Annelida, six Mollusca, three Arthropoda, eleven Chordata (one Ascidiacea, one Elasmobranchii and nine Teleostei) and extending from the Western Mediterranean to the Levantine Sea. All these records were reported from nine countries from the western to the eastern Mediterranean Sea, with a broad biogeographical coverage as follows: Spain: first records of the sacoglossans Cyerce graeca and Placida tardyi for the Alboran Sea and first records of the nudibranch Marionia gemmii for the Mediterranean waters of Spain; first records of nudibranch Algarvia alba in the Mediterranean Sea. Italy: First report of the long-legged crab Paragalene longicrura, a further new Mediterranean record of the rare offshore rockfish Pontinus kuhlii, first documented record of the spiny butterfly ray Gymnura altavela in Sardinia (Tyrrhenian Sea), new record of the red‐spotted wrasse Lappanella fasciata from the Messina Strait, first documented record of the rarely observed brown moray Gymnothorax unicolor in the Ionian coast, first record of the colonial ascidian Botrylloides israeliensis, first record of the Morocco dentex Dentex maroccanus, first record of mottled shore crab Pachygrapsus maurus and of an adult specimen of barracudina Lestidiops sphyrenoides in the Adriatic Sea, and further new Mediterranean records of Ross worm Sabellaria spinulosa along the same coast. Tunisia: second record of smalleye squaretail Tetragonurus cuvieri from the African Mediterranean coast. Slovenia: first records of the sea slug Trapania graeffei and Melanochlamys wildpretii, with the last one also representing the northernmost finding of this species. Croatia: northernmost record of the endangered twaite shad Alosa fallax in the Adriatic coast. Albania: first records of the Mediterranean spearfish Tetrapturus belone. Türkiye: first record from the Aegean coasts for Türkiye of the green macroalgae Cladophora battersii and Valonia aegagropila. Israel: first record of the skeleton shrimp Caprella acanthifera in the Southeastern Mediterranean Sea. Syria: first record of the Smooth grenadier Nezumia aequalis from Syrian marine waters