1,084 research outputs found

    Proizvodnja polinezasićenih masnih kiselina s pomoću plijesni Mucor recurvus sp. upotrebom melase šećerne trske kao izvora ugljika

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    Sugarcane molasses is rich in nutriments and vitamins. It may be used as the carbon source for the production of polyunsaturated fatty acids (PUFA) by Mucor recurvus sp. Using sugarcane molasses, the effects of fermentation parameters and media components on polyunsaturated fatty acid production through both linear and orthogonal array experiments were investigated. The best fermentation conditions for PUFA production were found as follows: 15 % sugarcane molasses, pH=6.0, 28 °C, 5 days, 160 rpm. It was also found that molasses and urea enhanced PUFA production with the optimal carbon to nitrogen (C/N) ratio of 35. Under the most favourable conditions, the total lipid content at 7.13 g/L and PUFA up to 5.74 g/L including (0.82±0.05) g/L of linolenic acid (LA), (1.35±0.02) g/L of γ-linolenic acid (GLA), (0.17±0.06) g/L of α-linolenic acid (ALA), (0.57±0.06) g/L of arachidonic acid (ARA), (0.46±0.07) g/L of eicosapentaenoic acid (EPA) and (0.34±0.08) g/L of docosahexaenoic acid (DHA) were obtained. Our study suggests that sugarcane molasses is a superior alternative carbon source for industrial PUFA production.Melasa šećerne trske je bogata hranjivim tvarima i vitaminima. Upotrebljava se kao izvor ugljika za proizvodnju polinezasićenih masnih kiselina s pomoću plijesni Mucor recurvus sp. Linearnom i ortogonalnom metodom istražen je utjecaj uvjeta fermentacije i sastojaka podloge, uz dodatak melase šećerne trske, na proizvodnju polinezasićenih masnih kiselina. Najbolji uvjeti fermentacije za proizvodnju polinezasićenih masnih kiselina bili su: 15 % melase šećerne trske; pH=6,0; 28 °C; 5 dana i 160 rpm. Također je utvrđeno da dodatak melase i uree povećava proizvodnju pri optimalnom omjeru ugljika i dušika C/N=35. Pri optimalnim uvjetima proizvedeno je ukupno 7,13 g/L lipida i 5,74 g/L polinezasićenih masnih kiselina, od toga (0,82±0,05) g/L linolenske kiseline, (1,35±0,02) g/L γ-linolenske kiseline, (0,17±0,06) g/L α-linolenske kiseline, (0,57±0,06) g/L arahidonske kiseline, (0,46±0,07) g/L eikosapentenoične kiseline i (0,34±0,08) g/L dokosaheksaenoične kiseline. Ovo je istraživanje pokazalo da je melasa šećerne trske najbolji alternativni izvor ugljika za industrijsku proizvodnju polinezasićenih masnih kiselina

    Au impact on GaAs epitaxial growth on GaAs (111)B substrates in molecular beam epitaxy

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    GaAs growth behaviour under the presence of Au nanoparticles on GaAs {111}(B) substrate is investigated using electron microscopy. It has been found that, during annealing, enhanced Ga surface diffusion towards Au nanoparticles leads to the GaAs epitaxial growth into {113}(B) faceted triangular pyramids under Au nanoparticles, governed by the thermodynamic growth, while during conventional GaAs growth, growth kinetics dominates, resulting in the flatted triangular pyramids at high temperature and the epitaxial nanowires growth at relatively low temperature. This study provides an insight of Au nanoparticle impact on GaAs growth, which is critical for understanding the formation mechanisms of semiconductor nanowires. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4792053

    Expression of CD147 on monocytes/macrophages in rheumatoid arthritis: its potential role in monocyte accumulation and matrix metalloproteinase production

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    Monocytes/macrophages play an important role in rheumatoid arthritis (RA) pathogenesis. They can activate fibroblasts through many molecules, including IL-1 and tumor necrosis factor-alpha, but there have been very few reports on the role of CD147 in RA. In our study, the results of flow cytometry reveal that the mean fluorescence intensity (MFI) of CD147 expression on CD14+ monocytes of peripheral blood from RA patients was higher than that in normal control and ankylosing spondylitis (AS) patients. The MFI of CD147 expression on the CD14+ monocytes in RA synovial fluid was higher than that in RA peripheral blood. Immunohistochemical staining shows that CD147 expression in RA synovium correlated with matrix metalloproteinase (MMP)-1 expression. A double immunofluorescent assay shows that CD147 was expressed on CD68+ cells in RA synovium. The potential role of CD147 in cyclophilin A (CyPA)-mediated cell migration was studied using a chemotaxis assay in vitro and it was found that the addition of anti-CD147 antibody or a CD147 antagonistic peptide significantly decreased the chemotactic index of the mononuclear cells. The role of CD147 in MMP production and cell invasion in vitro were studied through the co-culture of human CD14+ monocytes or monocytic line THP-1 cells and human fibroblasts, as well as by gel zymography and an invasion assay. Significantly elevated release and activation of MMP-9 and/or MMP-2 were seen in the co-culture of human monocytes/THP-1 cells and fibroblasts compared with cultures of the cells alone. An increased number of cells invading through the filters in the invasion assays was also observed in the co-cultured cells. The addition of CD147 antagonistic peptide had some inhibitory effect, not only on MMP production but also on cell invasion in the co-culture. Our study demonstrates that the increased expression of CD147 on monocytes/macrophages in RA may be responsible for elevated MMP secretion, cell invasion and CyPA-mediated cell migration into the joints, all of which may contribute to the cartilage and bone destruction of RA. These findings, together with a better understanding of CD147, CyPA and RA, will help in the development of innovative therapeutic interventions for RA

    Gemcitabine enhances cell invasion via activating HAb18G/CD147-EGFR-pSTAT3 signaling

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    Pancreatic cancer, one of the most lethal cancers, has very poor 5-year survival partly due to gemcitabine resistance. Recently, it was reported that chemotherapeutic agents may act as stressors to induce adaptive responses and to promote chemoresistance in cancer cells. During long-term drug treatment, the minority of cancer cells survive and acquire an epithelial-mesenchymal transition phenotype with increased chemo-resistance and metastasis. However, the short-term response of most cancer cells remains unclear. This study aimed to investigate the short-term response of pancreatic cancer cells to gemcitabine stress and to explore the corresponding mechanism. Our results showed that gemcitabine treatment for 24 hours enhanced pancreatic cancer cell invasion. In gemcitabine-treated cells, HAb18G/CD147 was up-regulated; and HAb18G/CD147 down-regulation or inhibition attenuated gemcitabine-enhanced invasion. Mechanistically, HAb18G/CD147 promoted gemcitabine-enhanced invasion by activating the EGFR (epidermal growth factor receptor)-STAT3 (signal transducer and activator of transcription 3) signaling pathway. Inhibition of EGFR-STAT3 signaling counteracted gemcitabine-enhanced invasion, and which relied on HAb18G/CD147 levels. In pancreatic cancer tissues, EGFR was highly expressed and positively correlated with HAb18G/CD147. These data indicate that pancreatic cancer cells enhance cell invasion via activating HAb18G/CD147-EGFR-pSTAT3 signaling. Our findings suggest that inhibiting HAb18G/CD147 is a potential strategy for overcoming drug stress-associated resistance in pancreatic cancer

    WebIBC: Identity Based Cryptography for Client Side Security in Web Applications

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    The growing popularity of web applications in the last few years has led users to give the management of their data to online application providers, which will endanger the security and privacy of the users. In this paper(1), we present WebIBC, which integrates public key cryptography into web applications without any browser plugins. The public key of WebIBC is provided by identity based cryptography, eliminating the need of public key and certificate online retrieval; the private key is supplied by the fragment identifier of the URL inspired by BeamAuth [6]. The implementation and performance evaluation demonstrate that WebIBC is secure and efficient both in theory and practice.Computer Science, Theory & MethodsCPCI-S(ISTP)
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