1,153 research outputs found

    Extraction and characterization of chitin and chitosan from crustacean by-products: Biological and physicochemical properties

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    Chitin has been extracted from two Tunisian crustacean species. The obtained chitin was transformed into the more useful soluble chitosan. These products were characterized by their biological activity as antimicrobial and antifungal properties. The tested bacterial strains were Escherichia coli American Type Cell Culture (ATCC) 25922, Pseudomonas aeruginosa ATCC 27950 and Staphylococcus aureus ATCC 25923. Four fungi strains were also tested Candida glabrata, Candida albicans, Candidaparapsilensis and Candida kreusei. Squilla chitosan showed a minimum inhibitory concentration (MIC) against the different fungi exceptionally for C. kreusei. Their antioxidant activity was investigated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and inhibition of linoleic acid peroxidation. Parapenaeus longirostris Chitosan showed the highest radical scavenging properties. Chitin and chitosan produced were also characterized with Fourier Transform Infrared Spectroscopy (FTIR).Key words: Antibacterial, antifungal, antioxidant, chitin, chitosan, crustacean

    Generalized β\beta-conformal change and special Finsler spaces

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    In this paper, we investigate the change of Finslr metrics L(x,y)Lˉ(x,y)=f(eσ(x)L(x,y),β(x,y)),L(x,y) \to\bar{L}(x,y) = f(e^{\sigma(x)}L(x,y),\beta(x,y)), which we refer to as a generalized β\beta-conformal change. Under this change, we study some special Finsler spaces, namely, quasi C-reducible, semi C-reducible, C-reducible, C2C_2-like, S3S_3-like and S4S_4-like Finsler spaces. We also obtain the transformation of the T-tensor under this change and study some interesting special cases. We then impose a certain condition on the generalized β\beta-conformal change, which we call the b-condition, and investigate the geometric consequences of such condition. Finally, we give the conditions under which a generalized β\beta-conformal change is projective and generalize some known results in the literature.Comment: References added, some modifications are performed, LateX file, 24 page

    Molecular and serological study by using ELISA and rRT-PCR techniques to detect avian infectious bronchitis virus in chickens in Middle Euphrates

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    The study was conducted to detect Infectious Bronchitis Virus (IBV) in commercial chicken farms of Middle Euphrates, the technique have been used throughout the study protocol, Enzyme-Linked Immunosorbent Assay (ELISA), Real-Time Reverse Transcription Polymerase Chain Reaction (RT-PCR) and histopathological study. (172) serum samples were collected from clinically infected vaccinated broiler farm and (29) serum samples were collected from clinically infected non-vaccinated broiler farm and screened for the presence of IBV antibodies by ELISA.75serum samples from 172 samples were positive, (43.6%) distributed as followed 43 (61.4%) from Hella, 23 (36.5%) from Najaf and 9 (23.07%) from Diwaniyah ,29 serum samples collected from clinically infected non-vaccinated broiler flocks, were 5 (17.2%) serum positive samples for IBV. (75) tissue samples from clinically infected vaccinated broilers distributed were submitted for rRT-PCR technique, the results were as followed42 (56%) have been detected IBV, while 30 (71.4%) was positive in ELISA, and (15) samples from clinically infected non-vaccinated broilers showed 8 (53.3%) IBV were detectable while 5 (62.5%) was positive in ELISA. Also, the research includes studying the histopathological changes of trachea, lung, and kidney of infected birds which were positive for rRT-PCR

    Effects of ultrasound irradiation on the release profile of 5-fluorouracil from magnetic polylactic co-glycolic acid nanocapsules

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    Background: Drug nano-carriers are one of the most important tools for targeted cancer therapy so that undesired side effects of chemotherapy drugs are minimized. In this area, the use of ultrasound can be helpful in controlling drug release from nanoparticles to achieve higher treatment efficiency. Objective: Here, we studies the effects of ultrasound irradiation on the release profile of 5-fluorouracil (5-Fu) loaded magnetic poly lactic co-glycolic acid (PLGA) nanocapsules. Methods: 5-Fu loaded magnetic PLGA nanocapsules were synthesized by multiple emulsification method. Particle size was measured by dynamic light scattering (DLS) and transmission electron microscope (TEM). The pattern of drug release was assessed with and without 3 MHz ultrasound waves at intensities of 0.3, 0.5 and 1 w/ cm2 for exposure time of 5 and 10 min in phosphate-buffered saline (PBS). Results: The size of nanoparticles was about 70 nm. Electron microscope images revealed the spherical shape of nanoparticles. The results demonstrated that the intensity and exposure time of ultrasound irradiation have significant effects on the profile of drug release from nanoparticles. Conclusion: It may be concluded that the application of ultrasound to control the release profile of drug loaded nanocapsules would be a promising method to develop a controlled drug delivery strategy in cancer therapy. © 2016 Shiraz University of Medical Sciences. All rights reserved

    Self-assembly in solution of a reversible comb-shaped supramolecular polymer

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    We report a single step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a combshaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration or the temperature. Moreover, we have proved that the bulkiness of the side-chains have a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the density of arms can be reduced, by simply mixing with a low molar mass bis-urea

    Experimental and theoretical studies of NLO properties of organic–inorganic materials base on p-nitroaniline

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    Third order nonlinear optical properties of a serie of chromophores were investigated using nonlinear transmission (NLT), degenerate four waves mixing (DFWM) and third harmonic generation (THG) experiments. The investigations are completed by theoritical studies performed using quantum chemical semi empirical calculations. Theoretical calculation of UV–VIS spectra and second order molecular hyperpolarisabillity for organic–inorganic hybrid materials base on p-nitroalinine was presented. Third order nonlinear optical susceptibility of the studied compounds was evaluated using third harmonic generation (THG) set up at 1064 nm. The measurements were performed on thin films, deposited on a thick glass substrate

    Design, construction and operation of the ProtoDUNE-SP Liquid Argon TPC

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    The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, U.S.A. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of 7 × 6 × 7.2 m3. The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. ProtoDUNE-SP\u27s successful operation between 2018 and 2020 demonstrates the effectiveness of the single-phase far detector design. This paper describes the design, construction, assembly and operation of the detector components

    Searching for solar KDAR with DUNE

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    The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core of the Sun would provide a unique signature of dark matter annihilation. Since excellent angle and energy reconstruction are necessary to detect this monoenergetic, directional neutrino flux, DUNE with its vast volume and reconstruction capabilities, is a promising candidate for a KDAR neutrino search. In this work, we evaluate the proposed KDAR neutrino search strategies by realistically modeling both neutrino-nucleus interactions and the response of DUNE. We find that, although reconstruction of the neutrino energy and direction is difficult with current techniques in the relevant energy range, the superb energy resolution, angular resolution, and particle identification offered by DUNE can still permit great signal/background discrimination. Moreover, there are non-standard scenarios in which searches at DUNE for KDAR in the Sun can probe dark matter interactions

    Low exposure long-baseline neutrino oscillation sensitivity of the DUNE experiment

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    The Deep Underground Neutrino Experiment (DUNE) will produce world-leading neutrino oscillation measurements over the lifetime of the experiment. In this work, we explore DUNE\u27s sensitivity to observe charge-parity violation (CPV) in the neutrino sector, and to resolve the mass ordering, for exposures of up to 100 kiloton-megawatt-calendar years (kt-MW-CY), where calendar years include an assumption of 57% accelerator uptime based on past accelerator performance at Fermilab. The analysis includes detailed uncertainties on the flux prediction, the neutrino interaction model, and detector effects. We demonstrate that DUNE will be able to unambiguously resolve the neutrino mass ordering at a 4σ (5σ) level with a 66 (100) kt-MW-CY far detector exposure, and has the ability to make strong statements at significantly shorter exposures depending on the true value of other oscillation parameters, with a median sensitivity of 3σ for almost all true δCP values after only 24 kt-MW-CY. We also show that DUNE has the potential to make a robust measurement of CPV at a 3σ level with a 100 kt-MW-CY exposure for the maximally CP-violating values δCP=±π/2. Additionally, the dependence of DUNE\u27s sensitivity on the exposure taken in neutrino-enhanced and antineutrino-enhanced running is discussed. An equal fraction of exposure taken in each beam mode is found to be close to optimal when considered over the entire space of interest

    First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform

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    The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber with an active volume of 7.2× 6.1× 7.0 m3. It is installed at the CERN Neutrino Platform in a specially-constructed beam that delivers charged pions, kaons, protons, muons and electrons with momenta in the range 0.3 GeV/c to 7 GeV/c. Beam line instrumentation provides accurate momentum measurements and particle identification. The ProtoDUNE-SP detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment, and it incorporates full-size components as designed for that module. This paper describes the beam line, the time projection chamber, the photon detectors, the cosmic-ray tagger, the signal processing and particle reconstruction. It presents the first results on ProtoDUNE-SP\u27s performance, including noise and gain measurements, dE/dx calibration for muons, protons, pions and electrons, drift electron lifetime measurements, and photon detector noise, signal sensitivity and time resolution measurements. The measured values meet or exceed the specifications for the DUNE far detector, in several cases by large margins. ProtoDUNE-SP\u27s successful operation starting in 2018 and its production of large samples of high-quality data demonstrate the effectiveness of the single-phase far detector design
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