190 research outputs found

    Substrate suppression of oxidation process in pnictogen monolayers

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    2D materials present an interesting platform for device designs. However, oxidation can drastically change the system's properties, which need to be accounted for. Through {\it ab initio} calculations, we investigated freestanding and SiC-supported As, Sb, and Bi mono-elemental layers. The oxidation process occurs through an O2_2 spin-state transition, accounted for within the Landau-Zener transition. Additionally, we have investigated the oxidation barriers and the role of spin-orbit coupling. Our calculations pointed out that the presence of SiC substrate reduces the oxidation time scale compared to a freestanding monolayer. We have extracted the energy barrier transition, compatible with our spin-transition analysis. Besides, spin-orbit coupling is relevant to the oxidation mechanisms and alters time scales. The energy barriers decrease as the pnictogen changes from As to Sb to Bi for the freestanding systems, while for SiC-supported, they increase across the pnictogen family. Our computed energy barriers confirm the enhanced robustness against oxidation for the SiC-supported systems

    In vitro elicitation of intestinal immune Responses in Teleost Fish: evidence for a type IV hypersensitivity reaction in Rainbow Trout.

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    In fish the gut immune system has been the subject of few investigations until now. Here, we provide novel morphological and immunological data on the gut isolated from rainbow trout Salmo gairdneri. The pyloric (P) and terminal (T) segments of trout gut, when morphologically examined, evidenced lymphocytes and macrophages (MO) loosely dispersed in the intestinal mucosa and in the lamina propria in the absence of typical Peyer's patches-like structures. Furthermore, incubation of P and T sections with Candida albicans (Ca) and functional analysis of supernatants generated some interesting results. In fact, active supernatants, when compared with controls, exhibited cytokine-like activities attributable to the presence of interferon (IFN)-gamma and migration inhibiting factor (MIF), respectively. In particular, IFN-gamma-like activity gave rise to an enhancement of Ca phagocytosis by MO, whereas MIF inhibited MO migration in agarose. Taken together, these in vitro data suggest that the gut-associated lymphoreticular tissue in fish possesses the appropriate armamentarium to mount a type IV hypersensitivity response when challenged by microbial antigens

    The Use of Molecular Pathway Inhibitors in the Treatment of Osteosarcoma

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    Presently, the 5-year survival rate for metastatic osteosarcoma remains low despite advances in chemotherapeutics and neoadjuvant therapy. A majority of the morbidity and nearly all of the mortality in osteosarcoma rely not in the primary disease but in the metastatic disease. The pursuit of novel molecular therapies is attractive due to their targeted ability to combat metastasis. Unlike traditional chemotherapy agents, which work by targeting rapidly dividing cells, targeted therapies may spare normal cells and decrease the adverse effects of chemotherapy by targeting specific pathways. Here, we discuss key molecular pathways in osteosarcoma and their ability to be modulated for the goal of eradication of primary and metastatic disease. We focus specifically on the aldehyde dehydrogenase (ALDH), epidermal growth factor receptor (EGFR), and insulin-like growth factor-1 receptor (IGF-1R) pathways

    A Morphological and Ultrastructural Study of the Anterior Digestive Tract of Adult Nile Tilapia Oreochromis niloticus

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    Among the most-used fish species in aquaculture is the Nile tilapia, due to its rapid growth rate and its adaptation to a wide range of farming conditions. A careful description of the morphology of the digestive tract, particularly the esophagus and stomach, allows a better understanding of the relationship between structure and function. Combining scanning and light microscopy we highlighted the presence of five different zones in the stomach (1: esophagus-gastric lumen passage; 2: descending glandular portion; 3: fundic portion; 4: ascending glandular portion; 5: gastric-pyloric transition portion). Histochemical investigation showed a secretion of carboxylates mucopolysaccharides along the esophagus and sulphated complex carbohydrates in the stomach. These results suggest that mucins play a protective role of the epithelial lining, which is essential for a correct digestive process. Finally, the characterization of the main cellular structures may be inspiring for more advanced studies aiming to decipher the role of specific molecules, such as neuropeptides, involved in the physiological digestive process

    Integrated olfactory receptor and microarray gene expression databases

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    <p>Abstract</p> <p>Background</p> <p>Gene expression patterns of olfactory receptors (ORs) are an important component of the signal encoding mechanism in the olfactory system since they determine the interactions between odorant ligands and sensory neurons. We have developed the Olfactory Receptor Microarray Database (ORMD) to house OR gene expression data. ORMD is integrated with the Olfactory Receptor Database (ORDB), which is a key repository of OR gene information. Both databases aim to aid experimental research related to olfaction.</p> <p>Description</p> <p>ORMD is a Web-accessible database that provides a secure data repository for OR microarray experiments. It contains both publicly available and private data; accessing the latter requires authenticated login. The ORMD is designed to allow users to not only deposit gene expression data but also manage their projects/experiments. For example, contributors can choose whether to make their datasets public. For each experiment, users can download the raw data files and view and export the gene expression data. For each OR gene being probed in a microarray experiment, a hyperlink to that gene in ORDB provides access to genomic and proteomic information related to the corresponding olfactory receptor. Individual ORs archived in ORDB are also linked to ORMD, allowing users access to the related microarray gene expression data.</p> <p>Conclusion</p> <p>ORMD serves as a data repository and project management system. It facilitates the study of microarray experiments of gene expression in the olfactory system. In conjunction with ORDB, ORMD integrates gene expression data with the genomic and functional data of ORs, and is thus a useful resource for both olfactory researchers and the public.</p

    Repeatability and temporal consistency of lower limb biomechanical variables expressing interlimb coordination during the double-support phase in people with and without stroke sequelae

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    Reliable biomechanical methods to assess interlimb coordination during the double-support phase in post-stroke subjects are needed for assessing movement dysfunction and related variability. The data obtained could provide a significant contribution for designing rehabilitation programs and for their monitorisation. The present study aimed to determine the minimum number of gait cycles needed to obtain adequate values of repeatability and temporal consistency of lower limb kinematic, kinetic, and electromyographic parameters during the double support of walking in people with and without stroke sequelae. Eleven post-stroke and thirteen healthy participants performed 20 gait trials at self-selected speed in two separate moments with an interval between 72 h and 7 days. The joint position, the external mechanical work on the centre of mass, and the surface electromyographic activity of the tibialis anterior, soleus, gastrocnemius medialis, rectus femoris, vastus medialis, biceps femoris, and gluteus maximus muscles were extracted for analysis. Both the contralesional and ipsilesional and dominant and non-dominant limbs of participants with and without stroke sequelae, respectively, were evaluated either in trailing or leading positions. The intraclass correlation coefficient was used for assessing intra-session and inter-session consistency analysis. For most of the kinematic and the kinetic variables studied in each session, two to three trials were required for both groups, limbs, and positions. The electromyographic variables presented higher variability, requiring, therefore, a number of trials ranging from 2 to >10. Globally, the number of trials required inter-session ranged from 1 to >10 for kinematic, from 1 to 9 for kinetic, and 1 to >10 for electromyographic variables. Thus, for the double support analysis, three gait trials were required in order to assess the kinematic and kinetic variables in cross-sectional studies, while for longitudinal studies, a higher number of trials (>10) were required for kinematic, kinetic, and electromyographic variables.info:eu-repo/semantics/publishedVersio

    Revealing quantum Hall states in epitaxial topological half-Heusler semimetal

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    Prediction of topological surface states (TSS) in half-Heusler compounds raises exciting possibilities to realize exotic electronic states and novel devices by exploiting their multifunctional nature. However, an important prerequisite is identification of macroscopic physical observables of the TSS, which has been difficult in these semi-metallic systems due to prohibitively large number of bulk carriers. Here, we introduce compensation alloying in epitaxial thin films as an effective route to tune the chemical potential and simultaneously reduce the bulk carrier concentration by more than two orders of magnitude compared to the parent compound. Linear magnetoresistance is shown to appear as a precursor phase that transmutes into a TSS induced quantum Hall phase on further reduction of the coupling between the surface states and the bulk carriers. Our approach paves the way to reveal and manipulate exotic properties of topological phases in Heusler compounds.Comment: 8 pages, 4 figures. Supplementary Infromation contains 7 sections and 17 figure
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