Detoxification of Acid Drainage Using Inorganic pH Buffers in a Constant Flow Bioreactor

Author(s):  
Mark Anglin Harris ◽  
Santo Ragusa
Keyword(s):  
1990 ◽  
Vol 22 (3-4) ◽  
pp. 153-160 ◽  
Author(s):  
T. Okubo ◽  
M. Okada ◽  
A. Murakami ◽  
Y. Inamori

Effects of daily variation of flow on the performance of submerged anaerobic/aerobic biofilm systems were investigated both by laboratory study using synthetic wastewater and by field study using gray water. In laboratory study, concentration of dissolved organic carbon (DOC) in effluent from anaerobic filter fluctuated with daily variation of flow when average hydraulic retention time (HRT) was below 10 h. However, daily mean values of DOC under the varied flow was almost the same as those under constant flow within the same daily mean HRT. Aerobic filter linked to anaerobic filter reduced the concentration of DOC satisfactorily though the concentration in anaerobic filter increased under short HRT. In field study, percent removal of organic carbon by anaerobic filter was considerably smaller (20-30%) than that in laboratory study (90-95%) both at HRT of 20 h though it was improved up to 60-80% by aerobic filter. Effects of peaking factor of flow on the variation of DOC were evaluated by mathematical analysis. It seemed that the peaking factor hardly affected daily mean values of DOC within the same daily mean HRT though maximum values of DOC increased with the increase of peaking factor.


2021 ◽  
Vol 22 (9) ◽  
pp. 4425
Author(s):  
Alazne Arrazola Arrazola Sastre ◽  
Miriam Luque Luque Montoro ◽  
Hadriano M. Lacerda ◽  
Francisco Llavero ◽  
José L. Zugaza

Small guanosine triphosphatases (GTPases) of the Rab and Arf families are key regulators of vesicle formation and membrane trafficking. Membrane transport plays an important role in the central nervous system. In this regard, neurons require a constant flow of membranes for the correct distribution of receptors, for the precise composition of proteins and organelles in dendrites and axons, for the continuous exocytosis/endocytosis of synaptic vesicles and for the elimination of dysfunctional proteins. Thus, it is not surprising that Rab and Arf GTPases have been associated with neurodegenerative diseases such as Alzheimer’s and Parkinson’s. Both pathologies share characteristics such as the presence of protein aggregates and/or the fragmentation of the Golgi apparatus, hallmarks that have been related to both Rab and Arf GTPases functions. Despite their relationship with neurodegenerative disorders, very few studies have focused on the role of these GTPases in the pathogenesis of neurodegeneration. In this review, we summarize their importance in the onset and progression of Alzheimer’s and Parkinson’s diseases, as well as their emergence as potential therapeutical targets for neurodegeneration.


2012 ◽  
Vol 45 (4) ◽  
pp. 674-678 ◽  
Author(s):  
Lukas Lomb ◽  
Jan Steinbrener ◽  
Sadia Bari ◽  
Daniel Beisel ◽  
Daniel Berndt ◽  
...  

Serial femtosecond crystallography (SFX) using X-ray free-electron laser (FEL) sources has the potential to determine the structures of macromolecules beyond the limitation of radiation damage and without the need for crystals of sufficient size for conventional crystallography. In SFX, a liquid microjet is used to inject randomly oriented crystals suspended in their storage solution into the FEL beam. Settling of crystals in the reservoir prior to the injection has been found to complicate the data collection. This article details the development of an anti-settling sample delivery instrument based on a rotating syringe pump, capable of producing flow rates and liquid pressures necessary for the operation of the injector. The device has been used successfully with crystals of different proteins, with crystal sizes smaller than 20 µm. Even after hours of continuous operation, no significant impairment of the experiments due to sample settling was observed. This article describes the working principle of the instrument and sets it in context with regard to the experimental conditions used for SFX. Hit rates for longer measuring periods are compared with and without the instrument operating. Two versions of the instrument have been developed, which both deliver sample at a constant flow rate but which differ in their minimum liquid flow rates and maximum pressures.


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