batch systems
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2022 ◽  
Vol 3 (1) ◽  
pp. 1-10
Author(s):  
Massimo Pisu ◽  
Alessandro Concas ◽  
Giacomo Cao ◽  
Antonella Pantaleo

Cell cycle and its progression play a crucial role in the life of all living organisms, in tissues and organs of animals and humans, and therefore are the subject of intense study by scientists in various fields of biomedicine, bioengineering and biotechnology. Effective and predictive simulation models can offer new development opportunities in such fields. In the present paper a comprehensive mathematical model for simulating the cell cycle progression in batch systems is proposed. The model includes a structured population balance with two internal variables (i.e., cell volume and age) that properly describes cell cycle evolution through the various stages that a cell of an entire population undergoes as it grows and divides. The rate of transitions between two subsequent phases of the cell cycle are obtained by considering a detailed biochemical model which simulates the series of complex events that take place during cell growth and its division. The model capability for simulating the effect of various seeding conditions and the adding of few substances during in vitro tests, is discussed by considering specific cases of interest in tissue engineering and biomedicine.


2021 ◽  
Author(s):  
Pablo Arnal ◽  
Ariana Salvia

Actinides, which are toxic for humans, increased their presence in the hydrosphere over the last 80 years. Though actinide recovery from water and immobilization for safe storage is technically feasible, it remains a complex process. Herein, we preliminary studied SiO2@ZrO2 in recovering actinides from water and trapping them in a glass-ceramic upon thermal treatment. To simplify our experimental work, we surrogated radioactive actinides with stable cerium. In the first part of the work, we tested SiO2@ZrO2's ability to recover Ce from water in batch systems. Then, we thermally treated SiO2@ZrO2 with Ce to form a glass-ceramic. All batch experiments showed that SiO2@ZrO2 removes Ce from water. Moreover, all experiments show that SiO2@ZrO2 with Ce converts into a glass-ceramic upon thermal treatment. When heated up to 1000 °C, particles remained spherical, and Ce remained trapped within the structure of crystalline spheroids located between the outer surface and a 50 nm depth. When heated up to 1450 °C, sintering produced bigger particles than the original colloid, and Ce remained trapped within the structure of crystalline spheroids having a broad size distribution located everywhere in the particles.


Author(s):  
María Soledad Ruiz-Mora ◽  
Ruth Alfaro-Cuevas-Villanueva ◽  
Verónica Martínez-Miranda ◽  
Orlando Hernández-Cristóbal ◽  
Raúl Cortés-Martínez

Abstract This work investigated As(V) removal from aqueous solutions using calcium alginate microspheres with encapsulated iron nanoparticles (FeNPs) in batch systems. The kinetic, equilibrium, and thermodynamic parameters of the adsorption process were evaluated. Adsorbents were characterized using Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, and Zeta Potential techniques. The FeNPs were obtained by a simple and low-cost method and they were successfully encapsulated and uniformly dispersed over the microspheres' surface. Significantly fast adsorption kinetic rates were observed due to microspheres' particle size and FeNPs encapsulation. The chemisorption mechanism was recognized in both adsorbate-adsorbent systems. The As(V) isotherms data suggested that the process is associated with heterogeneous adsorption. Available sorption sites with different adsorption energies were related to the functional groups involved in removing As(V), such as hydroxyl and carboxyl groups. Significantly high adsorption capacities were obtained for both materials, suggesting they can be competitive compared to conventional adsorbents, even at low FeNPs concentrations. Besides FeNPs encapsulation enhancing arsenate removal, higher adsorption was obtained at slightly acidic pH values and, together with their small particle size, suggests that the microspheres have a great potential to be used as arsenate adsorbents in the water treatment for human consumption.


2021 ◽  
Author(s):  
Timm Bayer ◽  
Elizabeth Tomaszewski ◽  
Casey Bryce ◽  
Andreas Kappler ◽  
James Byrne

Laboratory-based studies on microbial Fe(II) oxidation are commonly performed over just a few weeks in small volumes with high substrate concentrations, resulting in geochemical gradients and volumetric effects caused by sampling. We used a chemostat to enable uninterrupted supply of medium, and investigated autotrophic growth of the nitrate-reducing Fe(II)-oxidizing culture KS for 24 days. We analysed Fe- and N-speciation, cell-mineral associations, and the identity of minerals. Results were compared to different batch systems (50 and 700 ml – static/shaken). The Fe(II) oxidation rate was highest in the chemostat with 7.57 mM Fe(II) d-1, while the extent was similar (averaged 92% of all Fe(II)). Short-range ordered Fe(III) phases, presumably ferrihydrite, precipitated and later goethite was detected in the chemostat. 1 mM solid phase Fe(II) remained in the chemostat, up to 15 µM of reactive nitrite was measured, and 42% of visualized cells were partially or completely mineral-encrusted, likely caused by abiotic oxidation of Fe(II) by nitrite. Despite (partial) encrustation, cells were still viable. Our results show that even with similar oxidation rates as in batch cultures, cultivating Fe(II)-oxidizing microorganisms under continuous conditions reveals mechanistic insights on the role of reactive intermediates for Fe(II) oxidation, mineral formation and cell-mineral interactions.


Life ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1300
Author(s):  
Francesca Marchetto ◽  
Marco Roverso ◽  
Davide Righetti ◽  
Sara Bogialli ◽  
Francesco Filippini ◽  
...  

One of the main concerns in industrialized countries is represented by per- and poly-fluoroalkyl substances (PFAS), persistent contaminants hardly to be dealt with by conventional wastewater treatment processes. Phyco-remediation was proposed as a green alternative method to treat wastewater. Synechocystis sp. PCC6803 is a unicellular photosynthetic organism candidate for bioremediation approaches based on synthetic biology, as it is able to survive in a wide range of polluted waters. In this work, we assessed the possibility of applying Synechocystis in PFAS-enriched waters, which was never reported in the previous literature. Respirometry was applied to evaluate short-term toxicity of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which did not affect growth up to 0.5 and 4 mg L−1, respectively. Continuous and batch systems were used to assess the long-term effects, and no toxicity was highlighted for both compounds at quite high concentration (1 mg L−1). A partial removal was observed for PFOS and PFOA, (88% and 37%, with removal rates of about 0.15 and 0.36 mg L−1 d−1, respectively). Measurements in fractionated biomass suggested a role for Synechocystis in the sequestration of PFAS: PFOS is mainly internalized in the cell, while PFOA is somehow transformed by still unknown pathways. A preliminary bioinformatic search gave hints on transporters and enzymes possibly involved in such sequestration/transformation processes, opening the route to metabolic engineering in the perspective application of this cyanobacterium as a new phyco-remediation tool, based on synthetic biology.


2021 ◽  
Vol 11 (19) ◽  
pp. 9355
Author(s):  
Candelaria Tejada-Tovar ◽  
Angel Villabona-Ortíz ◽  
Rodrigo Ortega-Toro

The objective of this study was to prepare bio adsorbents from agro-industrial wastes from yam starch (YSR) and plantain (PSR) production for its use in the removal of Cr (VI) and Ni (II) in aqueous solution in batch and continuous packed-bed column systems. Bromatological analysis showed that the biomaterials are rich in cellulose, lignin, hemicellulose, and SEM micrographs that evidence a mesoporous structure characteristic of materials of lignocellulosic origin. FTIR evidenced functional groups such as hydroxyl, carbonyl, and methyl, possibly involved in the uptake of metal ions. EDS and FTIR analysis after adsorption confirmed that the retention of the metals on the surface of the adsorbent materials was successful. Cr (VI) and Ni (II) removal efficiencies above 80% were achieved using YSR and PSR in batch systems at the different conditions evaluated. The optimum conditions for removing Ni (II) on PSR were a bed height of 11.4 cm and a temperature of 33 °C, while for YSR, they were: 43 °C and 9 cm for temperature and bed height respectively. The variable with the most significant influence on the removal of Cr (VI) in a batch system on the two bio adsorbents was temperature. In contrast, the adsorbent dose and temperature are relevant factors for PSR Ni (II) removal. Therefore, the residues from the preparation of yam and plantain starch have high potential for removing heavy metals from wastewater and are presented as an alternative for their final disposal.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Matthieu Landreau ◽  
HeeJun You ◽  
David A. Stahl ◽  
Mari K. H. Winkler

AbstractAmmonia-oxidizing archaea (AOA) are major players in the nitrogen cycle but their cultivation represents a major challenge due to their slow growth rate and limited tendency to form biofilms. In this study, AOA was embedded in small (~2.5 mm) and large (~4.7 mm) poly(vinyl alcohol) (PVA)—sodium alginate (SA) hydrogel beads cross-linked with four agents (calcium, barium, light, or sulfate) to compare the differences in activity, the diffusivity of nitrogen species (NH4+, NO2−, and NO3−), and polymer leakage in batch systems over time. Sulfate-bound PVA-SA beads were the most stable, releasing the lowest amount of polymer without shrinking. Diffusion coefficients were found to be 2 to 3 times higher in hydrogels than in granules, with ammonium diffusivity being ca. 35% greater than nitrite and nitrate. Despite a longer lag phase in small beads, embedded AOA sustained a high per volume rate of ammonia oxidation compatible with applications in research and wastewater treatment.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
J. Reppin ◽  
C. Beyer ◽  
T. Hartmann ◽  
F. Schluenzen ◽  
M. Flemming ◽  
...  

AbstractBatch scheduling systems are usually designed to maximise fair resource utilisation and efficiency, but are less well designed for demanding interactive processing, which requires fast access to resources while low upstart latency is only of secondary significance for high throughput of high performance computing scheduling systems. The computing clusters at DESY are intended as batch systems for end users to run massive analysis and simulation jobs enabling fast turnaround systems, in particular when processing is expected to feed back to operation of instruments in near real-time. The continuously increasing popularity of Jupyter Notebooks for interactive and online processing made an integration of this technology into the DESY batch systems indispensable. We present here our approach to utilise the HTCondor and SLURM backends to integrate Jupyter Notebook servers and the techniques involved to provide fast access. The chosen approach offers a smooth user experience allowing users to customize resource allocation tailored to their computational requirements. In addition, we outline the differences between the HPC and the HTC implementations and give an overview of the experience of running Jupyter Notebook services.


2021 ◽  
Author(s):  
Maisuls Iván ◽  
Yolanda Castro Martin ◽  
Alicia Duran ◽  
Dominic Lariviere ◽  
Pablo Arnal

<p>Fluoride is a natural contaminant of water ⁠that endangers many people worldwide when present in concentrations higher than 2 ppm. Here, fluoride removal by four different nanostructured colloidal particles (SiO<sub>2</sub>@ZrO<sub>2</sub><sup>nc</sup>, SiO<sub>2</sub>@ZrO<sub>2</sub><sup>c</sup>, @ZrO<sub>2</sub><sup>nc</sup>, and @ZrO<sub>2</sub><sup>c</sup>) was measured in batch systems within a period of 24 h. Surprisingly, these materials removed fluoride from the water solutions and reached equilibrium in less than 10 minutes. The combination of high specific surface and fast fluoride removal placed these materials among the top materials currently known in fluoride removal. Also, the impact of element leaching was measured and quantified. The influence of time, pH, and fluoride concentration on leaching of Zr and Si was evaluated with a response surface methodology. Leaching of Zr and Si continued for several hours and depended on first-order, quadratic and cross-product coefficients. Previous studies of fluoride removal with zirconium oxide often assumed that a decrease in fluoride concentration in the solution indicated that fluoride was bound to the surface of the oxide. Zirconium oxide's solubility in water is low, but not zero. Hence, Zr might have formed soluble fluorocomplexes. This is the first report of fluoride removal with zirconium oxide that studied the leaching of the solid to exclude the formation of soluble fluorocomplexes.</p>


2021 ◽  
Author(s):  
Maisuls Iván ◽  
Yolanda Castro Martin ◽  
Alicia Duran ◽  
Dominic Lariviere ◽  
Pablo Arnal

<p>Fluoride is a natural contaminant of water ⁠that endangers many people worldwide when present in concentrations higher than 2 ppm. Here, fluoride removal by four different nanostructured colloidal particles (SiO<sub>2</sub>@ZrO<sub>2</sub><sup>nc</sup>, SiO<sub>2</sub>@ZrO<sub>2</sub><sup>c</sup>, @ZrO<sub>2</sub><sup>nc</sup>, and @ZrO<sub>2</sub><sup>c</sup>) was measured in batch systems within a period of 24 h. Surprisingly, these materials removed fluoride from the water solutions and reached equilibrium in less than 10 minutes. The combination of high specific surface and fast fluoride removal placed these materials among the top materials currently known in fluoride removal. Also, the impact of element leaching was measured and quantified. The influence of time, pH, and fluoride concentration on leaching of Zr and Si was evaluated with a response surface methodology. Leaching of Zr and Si continued for several hours and depended on first-order, quadratic and cross-product coefficients. Previous studies of fluoride removal with zirconium oxide often assumed that a decrease in fluoride concentration in the solution indicated that fluoride was bound to the surface of the oxide. Zirconium oxide's solubility in water is low, but not zero. Hence, Zr might have formed soluble fluorocomplexes. This is the first report of fluoride removal with zirconium oxide that studied the leaching of the solid to exclude the formation of soluble fluorocomplexes.</p>


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