580 research outputs found
Microporous microcarrier biofilm for copper removal from industrial wastewaters
No full textHeavy metals (HM) in water bodies pose serious environmental and health threats. Bacterial exopolymeric substances (EPS) can be employed as active surfaces for HM cation binding. Biofilm-based systems, consisting of microporous microcarriers inoculated with specific metal-resistant bacterial strains, can represent an operative implementation of planktonic ones.
This study investigates copper (Cu(II)) removal from electroplating wastewaters by Serratia plymuthica strain As3-5a(5) characterized for Cu(II) high resistance (MIC of 476 mg L-1), EPS production (90 mg g-1 d.w) and biofilm formation (2.24 OD595nm/OD600nm). In non-proliferating cell planktonic system, strain As3-5a(5) removed up to 40% of Cu(II) from a 200 mg L−1 solution and 30% from wastewater. Metal desorption achieved by 0.1 M nitric acid was in the order of 50%. In biofilm-based systems, strain As3-5a(5) exhibited Cu(II) removal of 43% on cellulose acetate filter, 45% on calcium alginate beads, and 83% on gardening substrate, in 4-minute contact time.
To enhance cell viability, optimize cellular structure, and increase EPS formation, molasses was added as growth substrate. Preliminary data evidenced that EPS production increased, while maintaining the prevalent monosaccharides mannose and rhamnose as determined by NMR analysis. Flow cytometry method, assessed by using a Concanavalin-A fluorescent lectin with specific binding to the strain monosaccharides, will further validate these data.
This work provides insights for the development of a sustainable biological method for metal removal, also in view of new utilization of metal-bacterial complexes for catalytic purposes or recovery of metal itself in a circular economy frame. Acknowledgement. Research supported by Fondazione CARIPLO-Circular Economy 2020 project num. 1069-2020 “Heavy Metal Bio-recovery and Valorization-HMBV” https://sites.unimi.it/hmbv/. Melzi A. is awarded of a PhD fellowship by the University of Milan - Food Systems PhD Program
Melzi d'Eril, ambassadeur malgré lui. Un épisode des relations entre les Républiques Française et Cisalpine en 1798
No full textRoberts John M. Melzi d'Eril, ambassadeur malgré lui. Un épisode des relations entre les Républiques Française et Cisalpine en 1798. In: Revue d’histoire moderne et contemporaine, tome 9 N°2, Avril-juin 1962. pp. 111-137
Stability of neuroactive amino acids in cerebrospinal fluid under various conditions of processing and storage.
No full textReference interval for serum lipase measured by a method based on the methylresorufinester cleavage
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Comparison of changes in respiratory function and exercise oxygen uptake with losartan versus enalapril in congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy
No full textIn congestive heart failure (CHF), some of the effects of angiotensin- converting enzyme (ACE) inhibitors, such as an increase in exercise oxygen uptake (VO2), are mediated through prostaglandins. Angiotensin (AT1) receptor blockers apparently do not share potentiation of this biosystem. We tested whether losartan improves exercise VO2 in CHF and if the effect is the same as for enalapril. Sixteen men with CHF and 8 volunteers, all nonsmokers and not taking ACE, AT1 receptor, or cyclooxygenase inhibitors, were randomized to receive placebo, enalapril (10 mg 2 times daily), losartan (50 mg/day), each of these 2 drugs plus aspirin (325 mg/day), aspirin, or the same preparations in a reverse order, each for 3 weeks, with a 3-week washout period between treatments. Pulmonary function and VO2 were assessed at the end of each treatment. In CHF, losartan and enalapril caused a similar improvement of VO2 and exercise tolerance, which was absent in controls and was counteracted by aspirin (prostaglandin inhibition) when obtained with enalapril and not with losartan. While on enalapril, we also detected an increase in the diffusing lung capacity for carbon monoxide, which correlated with changes in VO2 and was antagonized by aspirin, suggesting the possibility that a prostaglandin-mediated functional improvement of the alveolar capillary membrane contributes to the rise in VO2. Thus, losartan is as effective as enalapril for exercise VO2 and exercise tolerance, but the mechanism seems to be dissociated from a prostaglandin biosystem activation. Losartan may represent an advancement in CHF because its efficacy on VO2 is similar to that of enalapril, but is not antagonized by aspirin
Integrated Vehicle Dynamics System through Coordinating Active Aerodynamics Control, Active Rear Steering, Torque Vectoring and Hydraulically Interconnected Suspension
No full textThis paper investigates integrated vehicle dynamics control through coordinating active aerodynamics control, active rear steering, torque vectoring and hydraulically interconnected suspension for improving the overall vehicle performance including handling, stability, and comfort. After developing each chassis control system, it is tested by various manoeuvres in order to assess each subsystem. Then, a rule-based coordinate system is proposed for integrated control of the four chassis control systems. Simulation investigation is performed to display the effectiveness of the proposed integrated vehicle dynamics system. Results demonstrate that the proposed control scheme is able to enhance the multiple performance indices of the vehicle including both the ride comfort, and the lateral stability, compared to the non-integrated control syste
Misura della lipasi con metodo con substrato cromogenico : definizione dei valori di riferimento
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