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191.
192.
The denitrification performance of a lab-scale anoxic rotating biological contactor (RBC) using landfill leachate with high
nitrate concentration was evaluated. Under a carbon to nitrogen ratio (C/N) of 2, the reactor achieved N-NO3
− removal efficiencies above 95% for concentrations up to 100 mg N-NO3
− l−1. The highest observed denitrification rate was 55 mg N-NO3
− l−1 h−1 (15 g N-NO3
− m−2 d−1) at a nitrate concentration of 560 mg N-NO3
− l−1. Although the reactor has revealed a very good performance in terms of denitrification, effluent chemical oxygen demand (COD)
concentrations were still high for direct discharge. The results obtained in a subsequent experiment at constant nitrate concentration
(220 mg N-NO3
− l−1) and lower C/N ratios (1.2 and 1.5) evidenced that the organic matter present in the leachate was non-biodegradable. A phosphorus
concentration of 10 mg P-PO4
3− l−1 promoted autotrophic denitrification, revealing the importance of phosphorus concentration on biological denitrification
processes. 相似文献
193.
Pilar Barnestein-Fonseca José Leiva-Fernández Francisca Vidal-España Antonio García-Ruiz Daniel Prados-Torres Francisca Leiva-Fernández 《BMC pulmonary medicine》2011,11(1):1-10
Background
Progressive airway inflammation and susceptibility to the airway colonisation and infection are characteristic for the pathophysiology of chronic obstructive pulmonary disease (COPD). Antimicrobial peptides (AMPs) are central to the function of the innate host immune response against microbial pathogens and are regulators of inflammation and immunity. S100A7/psoriasin, a recently described AMP, is an essential component of the human epithelia against invading pathogens and acts as an effector molecule of the host innate defence in the skin. We hypothesized that S100A7/psoriasin is involved in the airway mucosal immunity and differently regulated and expressed in the lung during progression of COPD.Methods
S100A7/psoriasin gene expression was assessed in bronchial biopsies and bronchoalveolar lavage (BAL) fluid cells of healthy controls and COPD patients. Using confocal microscopy and immunohistochemistry, the protein expression of S100A7/psoriasin was investigated.Results
Here, we report that S100A7/psoriasin, the major antimicrobial peptide of the human skin, is constitutively expressed in perinuclear granules of human bronchial epithelial cells and alveolar macrophages. Whereas typical activators of the innate immune response like TLR ligands and cytokines induced the upregulation of CXCL-8 mRNA and release of CXCL-8 by epithelial cells, S100A7/psoriasin mRNA expression was not modulated. To investigate a potential association of S100A7/psoriasin with COPD, S100A7/psoriasin mRNA expression was assessed in bronchial biopsies and BAL fluid cells of patients at different stages of COPD and controls. Overall, 10 healthy individuals and 34 COPD patients were enrolled in this study. We found an association of S100A7/psoriasin mRNA expression with bacterial detection in the tracheobronchial system (p = 0.0304), which was the strongest in individuals positive for with S. aureus (p = 0.0005). However, S100A7/psoriasin mRNA expression was not altered during the progression of COPD.Conclusions
S100A7/psoriasin gene expression is unchanged in the airways during COPD. The newly identified association of S100A7/psoriasin with S. aureus may provide new insights into the antimicrobial defence response of the human airways, leading to the induction of S100A7/psoriasin upon microbial challenge. 相似文献194.
Podosomes and invadopodia are actin-rich protrusions of the plasma membrane important for matrix degradation and cell migration. Most of the information in this field has been obtained in cancer cells, where the presence of invadopodia has been related to increased invasiveness and metastatic potential. The importance of the related podosome structure in other pathological or physiological processes that require cell invasion is relatively unexplored. Recent evidence indicates that essential components of podosomes are responsible for several human syndromes, some of which are characterized by serious developmental defects involving the craniofacial area, skeleton and heart, and very poor prognosis. Here we will review them and discuss the possible role of podosomes as a player in correct embryo development. 相似文献
195.
Several alternatives to the conventional alginate beads formulation were studied for encapsulation of invertase. Pectin was added to the alginate/enzyme solution while trehalose and β-cyclodextrin were added to the calcium gelation media. The effect of composition changes, freezing, drying methods (freeze, vacuum, or air drying), and thermal treatment were evaluated on invertase stability and its release kinetics from beads. The enzyme release mechanism from wet beads depended on pH. The addition of trehalose, pectin, and β-cyclodextrin modified the bead structure, leading in some cases to a release mechanism that included the relaxation of the polymer chains, besides Fickian diffusion. Enzyme release from vacuum-dried beads was much faster than from freeze-dried beads, probably due to their higher pore size. The inclusion of β-cyclodextrin and especially of pectin prevented enzyme activity losses during bead generation, and trehalose addition was fundamental for achieving adequate invertase protection during freezing, drying, and thermal treatment. Present results showed that several alternatives such as drying method, composition, as well as pH of the relese medium can be managed to control enzyme release. 相似文献
196.
197.
Rodríguez-Bonilla P López-Nicolás JM Méndez-Cazorla L García-Carmona F 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(15-16):1091-1097
In this work, a reversed phase high performance liquid chromatography (RP-HPLC) method was developed for the determination of pterostilbene in food samples. The novel method is based on the addition of cyclodextrins (CDs) to the mobile phase where the complexation of pterostilbene by CDs is carried out. In order to select the most suitable conditions for the RP-HPLC method, the effect of several physico-chemical parameters on the complexation of pterostilbene by CDs was studied. Our results show that the addition of 12 mM HP-β-CD to a 50:50 (v/v) methanol:water mobile phase at 25°C and pH 7.0 significantly improves the main analytical parameters. In addition, it was seen that pterostilbene forms a 1:1 complex with HP-β-CD, showing an apparent complexation constant of 251±13 M(-1). Finally, in order to study the validity of the proposed method, blueberries were analyzed and the concentration of pterostilbene has been determined. 相似文献
198.
del Pilar Ferraris M Barrera GI Padilla AP Rodríguez JA 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(26):2741-2745
The objective of this study was the development of affinity adsorbent particles with the appropriate characteristics to be applied in protein purification using the affinity ultrafiltration method. To prepare affinity macroligands Cibacron Blue 3GA, as a ligand molecule, was immobilized by covalent bonding onto yeast cell walls, the support material or matrix. The maximum attachment of the ligand to the matrix was 212 μmol/g (ligand dry weight/yeast dry weight). Lysozyme was selected as the protein model for the adsorption studies. Its adsorption onto the matrix without ligand and matrix with attached ligand were investigated batch-wise. The adsorption equilibrium isotherms appeared to follow a typical Langmuir isotherm. The maximum adsorption capacity (q(m)) of the Cell-Cibacron macroligand for lysozyme was 110 mg/ml of wet macroligand. The adsorbent was also employed for the separation of lysozyme from hen egg white. High purity lysozyme was obtained. 相似文献
199.
Gutiérrez-Escribano P González-Novo A Suárez MB Li CR Wang Y de Aldana CR Correa-Bordes J 《Molecular biology of the cell》2011,22(14):2458-2469
Nuclear Dbf2-related (NDR) protein kinases are essential components of regulatory pathways involved in cell morphogenesis, cell cycle control, and viability in eukaryotic cells. For their activity and function, these kinases require interaction with Mob proteins. However, little is known about how the Mob proteins are regulated. In Candida albicans, the cyclin-dependent kinase (CDK) Cdc28 and the NDR kinase Cbk1 are required for hyphal growth. Here we demonstrate that Mob2, the Cbk1 activator, undergoes a Cdc28-dependent differential phosphorylation on hyphal induction. Mutations in the four CDK consensus sites in Mob2 to Ala significantly impaired hyphal development. The mutant cells produced short hyphae with enlarged tips that displayed an illicit activation of cell separation. We also show that Cdc28 phosphorylation of Mob2 is essential for the maintenance of polarisome components at hyphal tips but not at bud tips during yeast growth. Thus we have found a novel signaling pathway by which Cdc28 controls Cbk1 through the regulatory phosphorylation of Mob2, which is crucial for normal hyphal development. 相似文献
200.