Cross sectional behavior of hot-rolled i-sections of austenitic stainless steel subjected to biaxial loading

El trabajo consiste en el análisis estructural de uniones soldadas típicas que se construyen sistemáticamente en las diferentes misiones sociales de viviendas en Venezuela. Se analiza la respuesta estática de las uniones mediante un código de elementos finitos implementado en el programa Abaqus y luego se analiza la verificación estructural arrojada por las normativas y por Software de carácter proyectual como Idea Static

Assessing worth of marine protected areas for the protection of threatened biodiversity using IUCN Red List and Red List Index. A pilot study in six mediterranean areas

Abstract The Mediterranean marine region is considered one of the world's biodiversity hotspots for conservation priorities due the high occurrence of rare and threatened species, endemism and high species richness. However, several pressure such as losses and alterations of habitats are ongoing and in order to increase conservation in this sea region, many marine protected areas were established, including Natura 2000 sites. The latter are areas designated under the Habitat and Bird Directives for the conservation of species in need of strict protection, so that they can reach a favourable conservation status. Species conservation status is also assessed through the IUCN (International Union for Conservation of Nature) Red List of Threatened Species. The aim of our study was to test whether IUCN Red List and the related Red List Index RLI (which aggregates in a single value all the information on conservation status of a particular set of species) can be used as a metrics to characterize MPAs, and orienting, consequently, local marine conservation policies. A pilot study was undertaken in the six Sicilian MPAs (Marine Protected Areas) and results highlighted that Egadi Island has a low RLI value (meaning that the MPA hosts many species with a threatened status) while the Capo Gallo MPA, at the opposite, as an high RLI value (i.e.less threatened species); the other four MPAs. Egadi, Pelagie, and Ustica showed similar distribution frequencies of Red List categories having similar RLI values. Biological resource use, natural system modifications, invasive species, and pollution all account for 90% of assessed threats. Outcomes of our study showed that IUCN indicators should be considered as a tool to: assess the conservation status of set of species in protected areas; drive prioritization in the decision process in order to support an effective management conservation plan; designate new MPAs

Sneaking into a Hotspot of Biodiversity: Coverage and Integrity of a Rhodolith Bed in the Strait of Sicily (Central Mediterranean Sea)

Habitat mapping, physical characteristics and benthic community of a rhodolith bed in the Pelagie Islands (Strait of Sicily, Mediterranean Sea) were studied through Multi–Beam Echo–Sounder (MBES), Remotely Operated Vehicle (ROV) and grab samples. The geomorphological analysis revealed an articulated and wide rhodolith bed; video inspections highlighted a bed with high coverage, few sandy patches and with a prevalence of the boxwork morphotype. A total of 207 taxa with 876 specimens were identified, and Polychaeta was the dominant taxon. Linguimaera caesaris, a Lessepsian benthic amphipod, was recorded in all sampling sites, and its presence represents an input to deepen the benthic assemblage research on the rhodolith bed. In terms of morphotype composition, dead/live ratio and species variability, the bed variability indicated a good status of health, although trawling signs were detected through ROV videos. The present study broadens the knowledge on Mediterranean rhodolith beds and supports the importance of survey and monitoring activities for the conservation and management of this important habitat

Marine Antimalarials

Malaria is an infectious disease causing at least 1 million deaths per year, and, unfortunately, the chemical entities available to treat malaria are still too limited. In this review we highlight the contribution of marine chemistry in the field of antimalarial research by reporting the most important results obtained until the beginning of 2009, with particular emphasis on recent discoveries. About 60 secondary metabolites produced by marine organisms have been grouped into three structural types and discussed in terms of their reported antimalarial activities. The major groups of metabolites include isonitrile derivatives, alkaloids and endoperoxide derivatives. The following discussion evidences that antimalarial marine molecules can efficiently integrate the panel of lead compounds isolated from terrestrial sources with new chemical backbones and, sometimes, with unique functional groups

Halogenated Indole Alkaloids from Marine Invertebrates

This review discusses the isolation, structural elucidation, and biological activities of halogenated indole alkaloids obtained from marine invertebrates. Meridianins and related compounds (variolins, psammopemmins, and aplicyanins), as well as aplysinopsins and leptoclinidamines, are focused on. A compilation of the 13C-NMR spectral data of these selected natural indole alkaloids is also provided

Bioactive Sesterterpenes and Triterpenes from Marine Sponges: Occurrence and Pharmacological Significance

Marine ecosystems (>70% of the planet’s surface) comprise a continuous resource of immeasurable biological activities and immense chemical entities. This diversity has provided a unique source of chemical compounds with potential bioactivities that could lead to potential new drug candidates. Many marine-living organisms are soft bodied and/or sessile. Consequently, they have developed toxic secondary metabolites or obtained them from microorganisms to defend themselves against predators [1]. For the last 30–40 years, marine invertebrates have been an attractive research topic for scientists all over the world. A relatively small number of marine plants, animals and microbes have yielded more than 15,000 natural products including numerous compounds with potential pharmaceutical potential. Some of these have already been launched on the pharmaceutical market such as Prialt® (ziconotide; potent analgesic) and Yondelis® (trabectedin or ET-743; antitumor) while others have entered clinical trials, e.g., alpidin and kahalalide F. Amongst the vast array of marine natural products, the terpenoids are one of the more commonly reported and discovered to date. Sesterterpenoids (C25) and triterpenoids (C30) are of frequent occurrence, particularly in marine sponges, and they show prominent bioactivities. In this review, we survey sesterterpenoids and triterpenoids obtained from marine sponges and highlight their bioactivities

How do cardiologists select patients for dual antiplatelet therapy continuation beyond 1 year after a myocardial infarction? Insights from the EYESHOT Post-MI Study

Background: Current guidelines suggest to consider dual antiplatelet therapy (DAPT) continuation for longer than 12 months in selected patients with myocardial infarction (MI). Hypothesis: We sought to assess the criteria used by cardiologists in daily practice to select patients with a history of MI eligible for DAPT continuation beyond 1 year. Methods: We analyzed data from the EYESHOT Post-MI, a prospective, observational, nationwide study aimed to evaluate the management of patients presenting to cardiologists 1 to 3 years from the last MI event. Results: Out of the 1633 post-MI patients enrolled in the study between March and December 2017, 557 (34.1%) were on DAPT at the time of enrolment, and 450 (27.6%) were prescribed DAPT after cardiologist assessment. At multivariate analyses, a percutaneous coronary intervention (PCI) with multiple stents and the presence of peripheral artery disease (PAD) resulted as independent predictors of DAPT continuation, while atrial fibrillation was the only independent predictor of DAPT interruption for patients both at the second and the third year from MI at enrolment and the time of discharge/end of the visit. Conclusions: Risk scores recommended by current guidelines for guiding decisions on DAPT duration are underused and misused in clinical practice. A PCI with multiple stents and a history of PAD resulted as the clinical variables more frequently associated with DAPT continuation beyond 1 year from the index MI