1,042 research outputs found

    Electrical activation of carbon in GaAs : implantation temperature effects

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    Carbon was implanted into GaAs at the energy of 1 MeV with doses between 131013 and 2 31015 cm22 at temperatures of 80 K, nominal room temperature (RT), and 300 °C. A markedly higher electrical activation was obtained in the samples implanted at 80 K compared to those implanted at RT or 300 °C, attaining a maximum hole concentration of 231019 cm23. The redistribution of the C profile during rapid thermal annealing at temperatures from 700 to 950 °C for 10 s was found negligible, independently of the implantation temperature. Similar improvements in the electrical properties were also verified in samples implanted at 80 K with a lower energy of 60 keV. We consider that despite the light mass of C ions, the reduced dynamic annealing at 80 K allows the accumulation of an abundance of As vacancies, which assist the C activation as a p-type dopant

    Right circumcaval ureter and double right renal vein in the Brazilian shorthair cat (Felis catus): two case reports

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    Variations of the renal veins are well described in the literature, although variations concerning the ureter are considered a rare finding in cats. The circumcaval ureter is one of the rarest variations of the ureter and is characterised by a loop of the ureter posterior to the caudal vena cava. This variant is also known as preureteral vena cava and retrocaval ureter. It is thought to be caused by a deviation during embryonic development of the aforementioned vein. Due to its rarity, there are scarce reports of the circumcaval ureter in cats, and its association with two renal veins makes it less common as well. These variations should be preoperatively identified in order to avoid complications in kidney transplants, ureteral surgeries and cystoscopies, for instance. The present work aims to report two cases of a circumcaval ureter with two renal veins in two different Brazilian shorthair cats (Felis catus)

    Intermittent applied mechanical loading induces subchondral bone thickening that may be intensified locally by contiguous articular cartilage lesions

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    Objectives: Changes in subchondral bone (SCB) and cross-talk with articular cartilage (AC) have been linked to osteoarthritis (OA). Using micro-computed tomography (micro-CT) this study: (1) examines changes in SCB architecture in a non-invasive loading mouse model in which focal AC lesions are induced selectively in the lateral femur, and (2) determines any modifications in the contralateral knee, linked to changes in gait, which might complicate use of this limb as an internal control. Methods: Right knee joints of CBA mice were loaded: once with 2weeks of habitual use (n=7), for 2weeks (n=8) or for 5weeks (n=5). Both left (contralateral) and right (loaded) knees were micro-CT scanned and the SCB and trabecular bone analysed. Gait analysis was also performed. Results: These analyses showed a significant increase in SCB thickness in the lateral compartments in joints loaded for 5weeks, which was most marked in the lateral femur; the contralateral non-loaded knee also showed transient SCB thickening (loaded once and repetitively). Epiphyseal trabecular bone BV/TV and trabecular thickness were also increased in the lateral compartments after 5 weeks of loading, and in all joint compartments in the contralateral knee. Gait analysis showed that applied loading only affected gait in the contralateral himd-limb in all groups of mice from the second week after the first loading episode. Conclusions: These data indicate a spatial link between SCB thickening and AC lesions following mechanical trauma, and the clear limitations associated with the use of contralateral joints as controls in such OA models, and perhaps in OA diagnosis

    Ruminal Degradability Of Agro-industrial Fruit Residues

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    The aim of this study was to evaluate the chemical composition and ruminal degradability of the dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of fruit residues. Three fistulated sheep were held collectively in a pen, and fed daily with the studied residues in a diet consisting of canarana grass (Echinochloa pyramidalis) and a concentrate of corn and soybeans. The animals were allowed an adjustment period of seven days. The residues were dried in the sun, crushed in a forage machine, sorted using a 4.0-mm sieve, and incubated for 3, 6, 12, 24, 48, 72, and 96 h using nonwoven bags (weight 60g/m2, 14 ×12 cm2). Chemical analyses of the residues were performed using a randomized block experimental design with split plots. The cherimoya and tamarind residues showed the highest concentrations of CP (12.66% and 11.79%) the ether extract of cherimoya residue was the highest at 22.30%stands out the sour soup residue. The cashew and guava residues showed the highest levels of lignin (22.13 and 18.34%). The effective degradability of DM for the pineapple and tamarind residues to a passage rate of 5%/h were 53.04% and 42.61%, respectively. The guava, cherimoya, and cashew residues showed lower values at 19.16%, 26.86%, and 29.21%, respectively. The cherimoya, guava and pineapple residues showed the highest values of potential degradability for CP at 87%, 81%, 86.02% and 90.94%, respectively, with an average effective degradability of 50.0% at the rate of 5%/h. The pineapple (35.38%) and tamarind residues (34.49%) showed higher values of the effective degradability of NDF at a passage rate of 5%/h. Among the studied residues, the pineapple residue showed the greatest potential for use in animal feed based on chemical composition and rates of degradability.37127929

    Growth inhibitory effects of 3′-nitro-3-phenylamino nor-beta-lapachone against HL-60: A redox-dependent mechanism

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    AbstractIn this study, the cytotoxicity, genotoxicity and early ROS generation of 2,2-dimethyl-(3H)-3-(N-3′-nitrophenylamino)naphtho[1,2-b]furan-4,5-dione (QPhNO2) were investigated and compared with those of its precursor, nor-beta-lapachone (nor-beta), with the main goal of proposing a mechanism of antitumor action. The results were correlated with those obtained from electrochemical experiments held in protic (acetate buffer pH 4.5) and aprotic (DMF/TBABF4) media in the presence and absence of oxygen and with those from dsDNA biosensors and ssDNA in solution, which provided evidence of a positive interaction with DNA in the case of QPhNO2. QPhNO2 caused DNA fragmentation and mitochondrial depolarization and induced apoptosis/necrosis in HL-60 cells. Pre-treatment with N-acetyl-l-cysteine partially abolished the observed effects related to the QPhNO2 treatment, including those involving apoptosis induction, indicating a partially redox-dependent mechanism. These findings point to the potential use of the combination of pharmacology and electrochemistry in medicinal chemistry
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