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金黄色葡萄球菌clfa基因表达产物在小鼠的免疫原性分析  [PDF]
杨明锋,陈创夫,曹旭东,刘君,王正荣,李贞,乔军
牲畜兽医学报 , 2010,
Abstract: ?为分析原核表达的金黄色葡萄球菌clfa部分基因表达产物的免疫原性,作者采用pcr方法从奶牛乳房炎病例中分离的金黄色葡萄球菌中克隆出clfa基因的部分片段,测序后用dnaman软件进行抗原位点分析。构建原核表达质粒clfa-pet-28a+,转化bl21(de3)菌,经iptg诱导表达。用hisbind柱纯化表达蛋白,加弗氏佐剂混匀后免疫小鼠。小鼠分娩后乳腺内攻菌,检查乳腺组织病理变化,乳腺组织中金葡菌数量和tnf-α水平来评价原核表达蛋白的免疫保护效果。结果显示转化bl21(de3)菌,经iptg诱导可以表达clfa蛋白。原核表达蛋白抗原免疫小鼠可以显著降低乳腺组织内金葡菌数量,tnf-α水平也显著低于对照组和全菌蛋白抗原组,提示原核表达的clfa蛋白免疫小鼠可以减少乳腺内金葡菌定植的数量,减轻乳腺内感染造成炎症的严重程度。本研究表明原核表达金黄色葡萄球菌clfa蛋白有一定的免疫保护效果,为奶牛乳房炎疫苗的研究提供科学依据。
Properties of Particleboard Made from Pretreated Particles of Rubberwood, EFB and Rubberwood-EFB Blend  [PDF]
A. Zaidon,A.M. Norhairul Nizam,M.Y. Mohd Nor,F. Abood
Journal of Applied Sciences , 2007,
Abstract: The increasing use of low formaldehyde emission adhesives such as Melamine Urea Formaldehyde (MUF) for bonding particleboard and other wood composites has led researchers to find ways to improve the durability of these products against biodeterioration agents. A study on the treatment of particleboard through soaking of particles with 2% boric acid and 0.2% deltamethrin solutions was conducted. Particleboards were produced utilizing treated particles of rubberwood (clone RRIM 2002), Empty Fruit Bunches (EFB) and rubberwood-EFB blend (70:30). A low formaldehyde emission MUF resin (E1-grade) was used as a binder. The boards were evaluated for resistance against termite and fungal attack, static bending, internal bonding and dimensional stability. The properties were compared with those of untreated boards. The results of this study showed that the resistance of E1 grade MUF-bonded rubberwood and EFB particleboards against white rot fungus (Pycnoporous sanguiness) and termite (Coptotermes curvignathus) can be enhanced through the proposed treatment method. The particleboards made from both rubberwood and rubberwood-EFB blend require longer pressing time (> 6 min). Boric acid offered better protection against white rot wheras deltamethrin was more effective against termite. The bonding quality of both treated rubberwood and rubberwood-EFB blend boards was inferior compared to that of untreated board. Nonetheless, all treated EFB particleboards have higher IB. The strength and stiffness properties of rubberwood and rubberwood-EFB blend particleboards for both dry and wet conditions were markedly reduced by the treatments. The treatments increased the dry MOR and MOE values of EFB boards but lowered the wet MOR and MOE values. The study also indicated that the presence of preservatives had markedly decreased the stability of rubberwood and rubberwood-EFB blend particleboards.
A Structural Model of the Staphylococcus aureus ClfA–Fibrinogen Interaction Opens New Avenues for the Design of Anti-Staphylococcal Therapeutics  [PDF]
Vannakambadi K. Ganesh equal contributor,Jose J. Rivera equal contributor,Emanuel Smeds,Ya-Ping Ko,M. Gabriela Bowden,Elisabeth R. Wann,Shivasankarappa Gurusiddappa,J. Ross Fitzgerald,Magnus H??k
PLOS Pathogens , 2008, DOI: 10.1371/journal.ppat.1000226
Abstract: The fibrinogen (Fg) binding MSCRAMM Clumping factor A (ClfA) from Staphylococcus aureus interacts with the C-terminal region of the fibrinogen (Fg) γ-chain. ClfA is the major virulence factor responsible for the observed clumping of S. aureus in blood plasma and has been implicated as a virulence factor in a mouse model of septic arthritis and in rabbit and rat models of infective endocarditis. We report here a high-resolution crystal structure of the ClfA ligand binding segment in complex with a synthetic peptide mimicking the binding site in Fg. The residues in Fg required for binding to ClfA are identified from this structure and from complementing biochemical studies. Furthermore, the platelet integrin αIIbβ3 and ClfA bind to the same segment in the Fg γ-chain but the two cellular binding proteins recognize different residues in the common targeted Fg segment. Based on these differences, we have identified peptides that selectively antagonize the ClfA-Fg interaction. The ClfA-Fg binding mechanism is a variant of the “Dock, Lock and Latch” mechanism previously described for the Staphylococcus epidermidis SdrG–Fg interaction. The structural insights gained from analyzing the ClfANFg peptide complex and identifications of peptides that selectively recognize ClfA but not αIIbβ3 may allow the design of novel anti-staphylococcal agents. Our results also suggest that different MSCRAMMs with similar structural organization may have originated from a common ancestor but have evolved to accommodate specific ligand structures.
欧 亚 种 葡 萄 简 约 栽 培 技 术  [PDF]
杨巧云1,王新香2
北方园艺 , 2010, DOI: 10.11937/bfyy.201017027
Abstract:
EVIDENCE FOR PAPER STRENGTH IMPROVEMENT BY INCLUSION OF FINES GENERATED FROM APMP OF EFB  [PDF]
Nurul Hasanah Kamaludin,Arniza Ghazali,Wan Rosli Wan Daud
Journal of Sustainability Science and Management , 2011,
Abstract: The oil-palm empty fruit bunch (EFB) was subjected to alkaline peroxide mechanical pulping (APMP) treatment concept for pulp production and paper-making purposes. Analysis showed that tensile strength of the pulp network increased twice as much by blending the pulp with 12% of the 400-mesh fines fraction recovered from the refining and screening streams. It was also observed that the recovered 400-mesh fines carried many forms, some being pitted vessel elements with long tube-like shapes of varying diameters as a result of vessel elongation. The ‘split’ vessels, however, were resemblances of narrow fibres and this arose from the splitting that occurred along the perforation of the cell wall. In the paper formed by the EFB APMP pulp network, the various forms of vessel element inter-locked with each other, filling the micro-voids, which were initially present as a result of partial bonding between the incompletely-fibrillated fibre bundles. It was the filling effects of these fines elements that were responsible for improving the tensile strength of the produced handsheet by 100%.
Influence of Solid Loading Concentrations, Inoculums Size and Nitrogen Sources on Ethanol Production from Empty Fruit Bunches (EFB) Hydrolysate in Separate Hydrolysis and Fermentation (SHF)
Mohd Asyraf Kassim,Nasrin Abu Bakar,Loh Soh Kheang,Astimar Aziz
Research Journal of Applied Sciences , 2012, DOI: 10.3923/rjasci.2011.310.319
Abstract: Malaysia is one of the largest palm oil producers in the world and the industry has contributed the significant income to the country for many years. With the rapid growth of palm oil production in Malaysia, the amount of biomass residues generated also has shown a corresponding increase. Mass generation of palm biomass particularly Empty Fruit Bunches (EFB) has been identified as one of the main environmental issue generated from palm oil industry. Conversion of EFB into value added products such as bioethanol has been identified as an alternative way to reduce accumulation of EFB in the plantation. In this study, the effects of different EFB concentration, inoculums size and nitrogen sources on bioethanol production using pre-treated EFB were investigated. The pulverized EFB was initially pre-treated with 1% (w/v) sodium hydroxide (NaOH) followed by acid hydrolysis using 0.7% (v/v) sulfuric acid (H2SO4) and enzymatic saccharification prior to fermentation via Separate Hydrolysis and Fermentation (SHF) mode with Saccharomyces cerevisiae were carried out. The enzymatic hydrolysis process of EFB indicated that the highest glucose concentration was obtained by using 15% (w/v) EFB with 26.35 g L-1 glucose and 4.6 g L-1 xylose, respectively. The fermentation of hydrolysate obtained from saccharified EFB at different solid loading indicated that the highest ethanol production was achieved at 10% (w/v) EFB with 10.45 g L-1 ethanol corresponding to ethanol yield (Yp/s) of 0.53 g g-1 glucose. The most suitable inoculums size for ethanol production from saccharified EFB hydrolysate was 10% (v/v) active S. cerevisiae and additional of peptone in the EFB hydrolysate was not significantly affected (p<0.5) the ethanol production. However, additional of peptone in the saccharified EFB hydrolysate was able to reduce period of fermentation from 72-48 h of incubation.
The Sortase A Substrates FnbpA, FnbpB, ClfA and ClfB Antagonize Colony Spreading of Staphylococcus aureus  [PDF]
Eleni Tsompanidou, Emma L. Denham, Mark J. J. B. Sibbald, Xiao-mei Yang, Jolien Seinen, Alexander W. Friedrich, Girbe Buist, Jan Maarten van Dijl
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0044646
Abstract: Staphylococcus aureus is an important human pathogen that is renowned both for its rapid transmission within hospitals and the community, and for the formation of antibiotic resistant biofilms on medical implants. Recently, it was shown that S. aureus is able to spread over wet surfaces. This motility phenomenon is promoted by the surfactant properties of secreted phenol-soluble modulins (PSMs), which are also known to inhibit biofilm formation. The aim of the present studies was to determine whether any cell surface-associated S. aureus proteins have an impact on colony spreading. To this end, we analyzed the spreading capabilities of strains lacking non-essential components of the protein export and sorting machinery. Interestingly, our analyses reveal that the absence of sortase A (SrtA) causes a hyper-spreading phenotype. SrtA is responsible for covalent anchoring of various proteins to the staphylococcal cell wall. Accordingly, we show that the hyper-spreading phenotype of srtA mutant cells is an indirect effect that relates to the sortase substrates FnbpA, FnbpB, ClfA and ClfB. These surface-exposed staphylococcal proteins are known to promote biofilm formation, and cell-cell interactions. The hyper-spreading phenotype of srtA mutant staphylococcal cells was subsequently validated in Staphylococcus epidermidis. We conclude that cell wall-associated factors that promote a sessile lifestyle of S. aureus and S. epidermidis antagonize the colony spreading motility of these bacteria.
Staphylococcus aureus Proteins Sbi and Efb Recruit Human Plasmin to Degrade Complement C3 and C3b  [PDF]
Tina K. Koch,Michael Reuter,Diana Barthel,Sascha B?hm,Jean van den Elsen,Peter Kraiczy,Peter F. Zipfel,Christine Skerka
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0047638
Abstract: Upon host infection, the human pathogenic microbe Staphylococcus aureus (S. aureus) immediately faces innate immune reactions such as the activated complement system. Here, a novel innate immune evasion strategy of S. aureus is described. The staphylococcal proteins surface immunoglobulin-binding protein (Sbi) and extracellular fibrinogen-binding protein (Efb) bind C3/C3b simultaneously with plasminogen. Bound plasminogen is converted by bacterial activator staphylokinase or by host-specific urokinase-type plasminogen activator to plasmin, which in turn leads to degradation of complement C3 and C3b. Efb and to a lesser extend Sbi enhance plasmin cleavage of C3/C3b, an effect which is explained by a conformational change in C3/C3b induced by Sbi and Efb. Furthermore, bound plasmin also degrades C3a, which exerts anaphylatoxic and antimicrobial activities. Thus, S. aureus Sbi and Efb comprise platforms to recruit plasmin(ogen) together with C3 and its activation product C3b for efficient degradation of these complement components in the local microbial environment and to protect S. aureus from host innate immune reactions.
Dimensional Stability Properties of Medium Density Fibreboard (MDF) from Treated Oil Palm (Elaeis guineensis) Empty Fruit Bunches (EFB) Fibres  [PDF]
Zawawi Ibrahim, Mansur Ahmad, Astimar Abdul Aziz, Ridzuan Ramli, Mohd Ariff Jamaludin, Suhaimi Muhammed, Aisyah Humaira Alias
Open Journal of Composite Materials (OJCM) , 2016, DOI: 10.4236/ojcm.2016.64009
Abstract: The aim of the study was to investigate the effect of pre-treatments by using sodium hydroxide (NaOH) and acetic acid on oil palm Empty Fruit Bunch (EFB) fibres for the production of Medium Density Fibreboard (MDF). The EFB fibres were treated with chemicals in the concentration range of 0.2%, 0.4%, 0.6% and 0.8% prior to refining. Single-homogenous layer MDF with 12 mm thickness and density of 720 kg/m3 was produced. Urea-Formaldehyde (UF) was applied at 10% loading (based on dry weight of dry fibres) as a binder. The physical properties (Water Absorption (WA) and Thickness Swelling (TS)) of the produced panels were tested according to European Standard, EN 622-5:2006. The results show that types of chemical used had greater effects than concentration on the dimensional stability of the MDF. EFB fibres treated with acetic acid produced MDF with better dimensional stability compared to the MDF NaOH treated fibres. High concentration of NaOH produced poor dimensional stability in the panels.
Effect of Combinative Pretreatments on Cellulose-to-Glucose Conversion of Empty Palm Fruit Bunch (EFB)  [PDF]
Yakindra Prasad Timilsena,Nicolas Brosse
Journal of Food Science and Technology Nepal , 2012, DOI: 10.3126/jfstn.v7i0.10613
Abstract: Various methods of pretreatments were investigated to their effect on cellulose to glucose conversion efficiency on enzymatic hydrolysis of a tropical agro-industrial waste residue (empty palm fruit bunch, EFB). Four different kinds of combinative pretreatments (autohydrolysis with and without naphthol, dilute acid prehydrolysis, soda prehydrolysis and enzymatic prehydrolysis) were tested for delignification during the first and the second steps of pretreatment. Each prehydrolysis step was seconded by the organosolv delignification with the same conditions of pretreatment. It was observed that all the combinative methods were far more efficient in delignification and enzymatic hydrolysis ability as compared to its one step counter parts. The combinative pretreatment method involving dilute acid prehydrolysis followed by organosolv delignification revealed the best result with respect to lignin removal and enzymatic hydrolysis. The resultant pulp contained very low Klason lignin (~5%) with high sugar conversion ratio (64% total reducing sugars). DOI: http://dx.doi.org/10.3126/jfstn.v7i0.10613 ? J. Food Sci. Technol. Nepal, Vol. 7 (81-85), 2012 ?
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