Search results for "rpe"
showing 10 items of 2566 documents
ON THE EFFECTS OF A CRACK PROPAGATING TOWARD THE INTERFACE OF A BIMATERIAL SYSTEM
2006
This paper deals with the influence of matrix cracks on the failure mode of bimaterial systems and composite materials. In order to investigate such an influence, the stress field near a crack embedded into the more yielding material and propagating perpendicularly to the interface, has been analyzed by using systematic numerical simulations. Such analysis has shown that the crack propagation give rises to transversal stresses that can damage the reinforcing materials when this has low modulus, as glass fibers, or low transversal strength, such as carbon fibers. Moreover, the longitudinal stress concentration can damage the reinforcing material only if this has high stiffness, as in the cas…
Identification of Bioactive Compounds in Polar and Nonpolar Extracts of Araujia sericifera
2017
Abstract Araujia sericifera is a native perennial, climbing laticiferous shrub from South America that is currently naturalized in many other countries. Previous data describe promising properties for A. sericifera, but no systematic study of its bioactive compounds and possible medicinal applications has been conducted to date. In the present study, aerial parts of A. sericifera (leaves, stems, and fruits) were explored by combining GC-MS and NMR spectroscopy analysis for both nonpolar (hexane) and polar (methanol) extracts. The hexanic extracts contained high amounts of pentacyclic triterpenes including two new metabolites, 3-tigloyl germanicol (18) and 3-tigloyl lupeol (19). The methanol…
Facing the face – the construction of the frontal face in prehistoric and ancient two- and three-dimensional images
2020
Interpersonal communication depends to a large extent on the human face, with its many sensory organs, easily recognizable features and expression capacities. This is clearly evidenced by the abund...
Applying the UDA‑ODA discrimination technique to a herpetological association: the case of the Middle Palaeolithic site of El Salt (Alcoi, Spain)
2022
AbstractEl Salt (Middle Palaeolithic; Alcoi, Spain) is a key site for understanding the disappearance of Neanderthals in the eastern Iberian Peninsula, a process that is observed along its stratigraphic sequence. To improve our understanding of the palaeoclimatic context in which this process took place, we applied the UDA-ODA discrimination technique to the fossil herpetological assemblages from Stratigraphic Units (SU) Xb (52.3 ± 4.6 ka) and V (45.2 ± 3.4/44.7 ± 3.4 ka). This method is based in the application of an ecological criterion, the maximum altitude of each species on each Iberian range, to discern and remove those areas that do not meet their ecological requirements (UDA) from t…
An execution in medieval Sicily: Computerised tomography scan analysis and 3D reconstruction of an ancient forensic context
2019
The bioarchaeological and forensic approach is increasingly applied in the study of funerary contexts in archaeology. Here, we present a case of an atypical medieval burial recently discovered in Piazza Armerina (Sicily), in which the integrated use of traditional bioarchaeological and forensic anthropology methods was crucial. The skeleton was lying in a prone position and was characterised by a peculiar injury pattern. We recorded six clear stab wound marks on the posterior surface of the sternum. The use of computerised tomography scan and 3D modelling techniques has made it possible to obtain a reliable reconstruction of the cause and modality of death, pointing to the execution of the …
Offerings for the gate: a ritual deposit at the West Gate of la Bastida de les Alcusses (Moixent, Valencia)
2015
En este trabajo se dan a conocer los resultados de las excavaciones llevadas a cabo en la Puerta Oeste de a Bastida de les Alcusses entre los años 2010 y 2011. Asociado a una renovación de las estructuras de la entrada y la muralla, se documentó un depósito de varios centenares de objetos incluyendo herrajes, maderas, armas, cerámica, semillas, frutos, fauna y restos constructivos. Presentamos el estudio multidisciplinar de todos los materiales y las varias líneas de interpretación que nos sugiere este extraordinario contexto.
Total Synthesis and Biological Investigation of (−)‐Artemisinin: The Antimalarial Activity of Artemisinin Is not Stereospecific
2018
Here, we describe an efficient and diversity-oriented entry to both (-)-artemisinin (1) and its natural antipode (+)-artemisinin, starting from commercially and readily available S-(+)- and R-(-)-citronellene, respectively. Subsequently, we answered the still open question regarding the specificity of artemisinins action. By using a drug-sensitive Plasmodium falciparum NF54 strain, we showed that the antimalarial activity of artemisinin is not stereospecific. Our straightforward and biomimetic approach to this natural endoperoxide enables the synthesis of artemisinin derivatives that are not accessible through applying current methods and may help to address the problem of emerging resistan…
Oxidative stress response of tumor cells: microarray-based comparison between artemisinins and anthracyclines
2004
The antimalarial artemisinins also reveal profound cytotoxic activity against tumor cells. Artemisinins harbor an endoperoxide bridge whose cleavage results in the generation of reactive oxygen species (ROS) and/or artemisinin carbon-centered free radicals. Established cancer drugs such as anthracyclines also form ROS and free radicals that are responsible for the cardiotoxicity of anthracyclines. In contrast, artemisinins do not reveal cardiotoxicity. In the present investigation, we compared the cytotoxic activities of different artemisinins (artemisinin, artesunate, arteether, artemether, artemisitene, dihydroartemisinylester stereoisomers) in 60 cell lines of the National Cancer Institu…
Toxicity of the antimalarial artemisinin and its dervatives.
2010
As long as no effective malaria vaccine is available, chemotherapy belongs to the most important weapons fighting malaria. One of the most promising new drug developments is the sesquiterpene artemisinin (ARS) and its derivatives, e.g., artemether, arteether, and sodium artesunate. Large clinical studies and meta-analyses did not show serious side effects, although proper monitoring of adverse effects in developing countries might not be a trivial task. There is a paucity of large-scale clinical trials suitable to detect rare but significant toxicity. Therefore, a final and definitive statement on the safety of artemisinins still cannot be made. In contrast, animal experiments show consider…
Antibacterial and antifungal activities of Otanthus maritimus (L.) Hoffmanns.Link essential oil from Sicily.
2013
The chemical composition of the essential oil obtained from the flowers of Otanthus maritimus L., a perennial plant growing wild in maritime sands in the Mediterranean region, was investigated by GC and GC-MS analyses. Totally 66 were identified. The oil was dominated by the high content of monoterpene compounds, especially oxygenated monoterpenes which accounted for 73.1%. The most abundant components were yomogi alcohol (20.8%), camphor (15.8%), artemisyl acetate (15.3%) and artemisia alcohol (13.7%). The oil was tested against two Gram (+) and six Gram (-) bacterial strains, both American Type Culture Collection standard strains and clinically isolated (CI), one potentially pathogenic ye…