Search results for "54"
showing 10 items of 2200 documents
Sedimentology of a Late Quaternary lacustrine record from the south-eastern Carpathian Basin
2021
The Upper Pleistocene geoarchives in the south‐eastern Carpathian Basin are represented predominantly by loess–palaeosol records. In 2015, a 10 m sediment core composed of clay‐rich lacustrine sediments was recovered by vibracoring a dry lake basin located between the Vršac Mountains (Serbia) and the Banat Sands in the south‐eastern Carpathian Basin; a location relevant for placing regional archaeological results in a palaeoenvironmental context. Here, we present results from geoelectrical prospection and a lithostratigraphic interpretation of this sequence supported by a detailed granulometric study supplemented by ostracod analysis. An age model based on luminescence dating is discussed a…
Everything you wanted to know about phase and reference frequency in one- and two-dimensional NMR spectroscopy
2019
The fundamental concept of phase discussed in this tutorial aimed at providing students with an explanation of the delays and processing parameters they may find in nuclear magnetic resonance (NMR) pulse programs. We consider the phase of radio-frequency pulses, receiver, and magnetization and how all these parameters are related to phases and offsets of signals in spectra. The impact of the off-resonance effect on the phase of the magnetization is discussed before presenting an overview of how adjustment of the time reference of the free induction decay avoids first-order correction of the phase of spectra. The main objective of this tutorial is to show how the relative phase of a pulse an…
Coñece-lo mundo baixomedieval hispánico a través dos seus refráns: Los refranes que dizen las viejas tras el fuego
2011
O obxectivo do presente artigo é destacar brevemente algúns aspectos socioculturais, políticos e económicos da baixa Idade Media do reino de Castela (e, por extensión, nalgúns casos, dos restantes reinos cristiáns peninsulares), extraíbles da fosilización formal de enunciados pluriverbais que coñecemos como refráns. Baséase, primeiro, na consideración do refrán como reflexo, en maior ou menor medida, da sociedade do seu tempo (e tamén de épocas anteriores) e, segundo, como depositario non só do saber tradicional que se transmite de xeración en xeración, senón tamén da cultura socioeconómica, material e ambiental de épocas pretéritas. Para iso emprégase como corpus textual os Refranes que di…
Anion-driven encapsulation of cationic guests inside pyridine[4]arene dimers
2019
Pyridine[4]arenes have previously been considered as anion binding hosts due to the electron-poor nature of the pyridine ring. Herein, we demonstrate the encapsulation of Me4N+ cations inside a dimeric hydrogen-bonded pyridine[4]arene capsule, which contradicts with earlier assumptions. The complexation of a cationic guest inside the pyridine[4]arene dimer has been detected and studied by multiple gas-phase techniques, ESI-QTOF-MS, IRMPD, and DT-IMMS experiments, as well as DFT calculations. The comparison of classical resorcinarenes with pyridinearenes by MS and NMR experiments reveals clear differences in their host–guest chemistry and implies that cation encapsulation in pyridine[4]arene…
In vitro impact preliminary assessment of airborne particulate from metalworking and woodworking industries.
2020
Abstract BackgroundInhalation is the main route of exposure to airborne pollutants. To evaluate the safety and assess the risks of occupational hazards different testing approaches are used. 3D airway epithelial tissues allow to mimic exposure conditions in vitro, generates human-relevant toxicology data, allows to elucidate mode of action of pollutants. ResultsGilian 3500 pumps equipped with Standard Midget Impingers were used to collect the airborne particulate from woodworking and metalworking environments. EpiAirway™ tissues were used to model half working day (4 h), full working day (8 h), and 3 working day exposures to occupational pollutants. Tissue viability was assessed using MTT a…
The yeast mitogen-activated protein kinase Slt2 is involved in the cellular response to genotoxic stress
2012
Abstract Background The maintenance of genomic integrity is essential for cell viability. Complex signalling pathways (DNA integrity checkpoints) mediate the response to genotoxic stresses. Identifying new functions involved in the cellular response to DNA-damage is crucial. The Saccharomyces cerevisiae SLT2 gene encodes a member of the mitogen-activated protein kinase (MAPK) cascade whose main function is the maintenance of the cell wall integrity. However, different observations suggest that SLT2 may also have a role related to DNA metabolism. Results This work consisted in a comprehensive study to connect the Slt2 protein to genome integrity maintenance in response to genotoxic stresses.…
Cytotoxicity, anti-angiogenic, apoptotic effects and transcript profiling of a naturally occurring naphthyl butenone, guieranone A
2012
Abstract Background Malignant diseases are responsible of approximately 13% of all deaths each year in the world. Natural products represent a valuable source for the development of novel anticancer drugs. The present study was aimed at evaluating the cytotoxicity of a naphtyl butanone isolated from the leaves of Guiera senegalensis, guieranone A (GA). Results The results indicated that GA was active on 91.67% of the 12 tested cancer cell lines, the IC50 values below 4 μg/ml being recorded on 83.33% of them. In addition, the IC50 values obtained on human lymphoblastic leukemia CCRF-CEM (0.73 μg/ml) and its resistant subline CEM/ADR5000 (1.01 μg/ml) and on lung adenocarcinoma A549 (0.72 μg/m…
Exosomal Heat Shock Proteins as New Players in Tumour Cell-to-cell Communication
2014
Exosomes have recently been proposed as novel elements in the study of intercellular communication in normal and pathological conditions. The biomolecular composition of exosomes reflects the specialized functions of the original cells. Heat shock proteins (Hsps) are a group of chaperone proteins with diverse biological roles. In recent years, many studies have focused on the extracellular roles played by Hsps that appear to be involved in cancer development and immune system stimulation. Hsps localized on the surface of exosomes, secreted by normal and tumour cells, could be key players in intercellular cross-talk, particularly during the course of different diseases, such as cancer. Exoso…
Biodistribution, Uptake and Effects Caused by Cancer-derived Extracellular Vesicles
2015
Extracellular vesicles (EVs) have recently emerged as important mediators of intercellular communication. They are released in the extracellular space by a variety of normal and cancerous cell types and have been found in all human body fluids. Cancer-derived EVs have been shown to carry lipids, proteins, mRNAs, non-coding and structural RNAs and even extra-chromosomal DNA, which can be taken up by recipient cells and trigger diverse physiological and pathological responses. An increasing body of evidence suggests that cancer-derived EVs mediate paracrine signalling between cancer cells. This leads to the increased invasiveness, proliferation rate and chemoresistance, as well as the acquisi…
Vida de Miguel de Cervantes Saavedra : escrita e ilustrada con varias noticias y documentos ineditos pertenecientes a la historia y literatura de su …
1819
Index Emblema xil. de l'Academia Española a port. Retrat calc. de Miguel de Cervantes en f. de làm.: Bs. Ametller lo dibujó y grabó" Grav. calc. en f. de làm. pleg., són genealogies Text a 1 col. Sign.: A-RR8, SS2