824 research outputs found

    Characterization of polygalacturonases produced by the endophytic fungus Penicillium brevicompactum in solid state fermentation - SSF

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    Polygalacturonases belong to the family of pectinases, enzymes that are in high demand in industry because of their many different applications. This study therefore sought to examine the production of polygalacturonases using an endophytic fungus, Penicilium brevicompactum, isolated from Baccharis dracunculifolia D.C. (Asteraceae) through semi solid fermentation using orange peels and citric pectin 2% as base substrate, supplemented with different carbon sources. After the fermentation process, the enzyme was characterized. The results showed that the micro-organism was able to use a wide range of carbon sources, but with polygalacturonase activity varying with each source. The highest yield, however, was achieved after 30 hours of incubation in the presence of 4% of galactose and 2% of pectin. Studies on the characterization of the polygalacturonase revealed that the optimal temperature of this enzyme is 72°C and that it maintains 60 and 15% of its maximum activity when incubated for 2 hours at 40 and 90°C, respectively. The optimal pH for the activity of the enzyme was 4.6. The enzyme retained 65 and 30% of its maximum activity when incubated at pH 3.5 and 9.5, respectively, for 24 hours at ambient temperature. The enzyme activity was stimulated by Mg2+ ions. On the other hand, it was inhibited by the ions Cs+2, Hg+2, Li+2 and Sr+2. The ions Zn+2 and Cu+2 inhibited it by 94% and 69%, respectively

    Expression of progesterone receptor membrane component-1 in bovine reproductive system during estrous cycle

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    Several reports suggest the participation of progesterone receptor membrane component 1 (PGRMC1) in progesterone signaling in the reproductive system. This study aimed at investigating the presence and localization of PGRMC1 in bovine ovary, oviduct and uterus, during the follicular and luteal phases of the estrous cycle. In the ovary, PGRMC1 has been detected in surface germinal epithelium, granulosa cells, theca cells and in the germinal vesicle of the oocytes at all stages of folliculogenesis. In the corpus luteum the expression of PGRMC1 was influenced by the stage of the estrous cycle. In the oviducts and in the uterus horns, PGRMC1 was immunolocalized in the luminal epithelium, in the muscle layer cells and in the endothelial cells. In the uterus, PGRMC1 was intensely localized also in the glandular endometrium. However, in the oviducts and in the uterus horns, the localization of PGRMC1 was independent on the stage of the estrous cycle and on whether evaluating the ipsilateral or the contralateral organ. In conclusion, the present immunohistochemical study showed that PGRMC1 is located in various compartments of the bovine female reproductive organs. With the exception of the corpora lutea, PGRMC1 localization showed similar pattern during different stages of the estrous cycle

    On the relationship between functional encryption, obfuscation, and fully homomorphic encryption

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    We investigate the relationship between Functional Encryption (FE) and Fully Homomorphic Encryption (FHE), demonstrating that, under certain assumptions, a Functional Encryption scheme supporting evaluation on two ciphertexts implies Fully Homomorphic Encryption. We first introduce the notion of Randomized Functional Encryption (RFE), a generalization of Functional Encryption dealing with randomized functionalities of interest in its own right, and show how to construct an RFE from a (standard) semantically secure FE. For this we define the notion of entropically secure FE and use it as an intermediary step in the construction. Finally we show that RFEs constructed in this way can be used to construct FHE schemes thereby establishing a relation between the FHE and FE primitives. We conclude the paper by recasting the construction of RFE schemes in the context of obfuscation.NSF -National Science Foundatio

    LNL irradiation facilities for radiation damage studies on electronic devices

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    In this paper we will review the wide range of irradiation facilities installed at the INFN Legnaro National Laboratories and routinely used for radiation damage studies on silicon detectors, electronic components and systems. The SIRAD irradiation facility, dedicated to Single Event Effect (SEE) and bulk damage studies, is installed at the 14MV Tandem XTU accelerator and can deliver ion beams from H up to Au in the energy range from 28MeV to 300 MeV. An Ion Electron Emission Microscope, also installed at SIRAD, allows SEE testing with micrometric sensitivity. For total dose tests, two facilities are presently available: an X-rays source and a 60Co γ-ray source. The 7MV Van de Graaff CN accelerator provides 1H beams in the energy range 2–7MeV and currents up to few μA for both total dose and bulk damage studies. At this facility, very high dose rates (up to ∼100 krad/s (SiO2)) can be achieved. Finally, also neutron beams are available, produced at the CN accelerator, by the reaction d + Be ⇒ n+B

    “Three-bullets” loaded mesoporous silica nanoparticles for combined photo/chemotherapy

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    This contribution reports the design, preparation, photophysical and photochemical characterization, as well as a preliminary biological evaluation of mesoporous silica nanoparticles (MSNs) covalently integrating a nitric oxide (NO) photodonor (NOPD) and a singlet oxygen (1O2) photosensitizer (PS) and encapsulating the anticancer doxorubicin (DOX) in a noncovalent fashion. These MSNs bind the NOPD mainly in their inner part and the PS in their outer part in order to judiciously exploit the different diffusion radius of the cytotoxic NO and 1O2. Furthermore this silica nanoconstruct has been devised in such a way to permit the selective excitation of the NOPD and the PS with light sources of different energy in the visible window. We demonstrate that the individual photochemical performances of the photoactive components of the MSNs are not mutually affected, and remain unaltered even in the presence of DOX. As a result, the complete nanoconstruct is able to deliver NO and 1O2 under blue and green light, respectively, and to release DOX under physiological conditions. Preliminary biological results performed using A375 cancer cells show a good tolerability of the functionalized MSNs in the dark and a potentiated activity of DOX upon irradiation, due to the effect of the NO photoreleased

    Characterization of alpha-Amylase Produced by the Endophytic Strain of Penicillium digitatum in Solid State Fermentation (SSF) and Submerged Fermentation (SmF)

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    Α-Amylases are enzymes responsible for breaking the α-1.4 bond in polysaccharides with three or more glucose units, occupying the second place in the most widely employed enzymes in industry in the world. The objective of this study was to compare the yields of α-amylase produced by the endophytic fungus, Penicillium digitatum, strain D1-FB, isolated from Baccharis dracunculifolia D.C. (Asteraceae), through the solid state fermentation (SSM) and submerged fermentation (SmF) processes, in addition to characterizing the produced enzyme. The two fermentations were conducted for 120 hours, taking samples every 24 hours to obtain the peaks of production. The enzymes were characterized according to their optimal pH and temperature for performance and stability regarding the incubation in the presence of ions, variations in pH and temperature. The maximum yield of the enzyme was observed with SSF, using rice bran as substrate after 72 hours of fermentation, with 1,625 U/mL. The α-amylase had an optimal pH at 6.5 and optimal temperature at 45°C. All the ions resulted in a decrease in the activity of α-amylase in the concentration of 5mM. The enzyme proved to be quite stable in a pH range of 6.0 to 7.5 and up to the temperature of 37°C, but it presented great drops in activity with temperatures above 45°C and in the presence of ions at the concentration of 5 mM
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