471 research outputs found
Ideas That Count: PALCUS 2020 Census Coloring Activity - Galo
https://digitalcommons.ric.edu/mpc2020/1006/thumbnail.jp
Ideas That Count: PALCUS 2020 Census Coloring Activity - Galo
https://digitalcommons.ric.edu/mpc2020/1006/thumbnail.jp
Ideas That Count: PALCUS 2020 Census Coloring Activity - Galo
https://digitalcommons.ric.edu/mpc2020/1006/thumbnail.jp
Bioprocess microfluidics: applying microfluidic devices for bioprocessing
Scale-down approaches have long been applied in bioprocessing to resolve scale-up problems. Miniaturized bioreactors have thrived as a tool to obtain process relevant data during early-stage process development. Microfluidic devices are an attractive alternative in bioprocessing development due to the high degree of control over process variables afforded by the laminar flow, and the possibility to reduce time and cost factors. Data quality obtained with these devices is high when integrated with sensing technology and is invaluable for scale-translation and to assess the economical viability of bioprocesses. Microfluidic devices as upstream process development tools have been developed in the area of small molecules, therapeutic proteins, and cellular therapies. More recently, they have also been applied to mimic downstream unit operations
A Dynamic Artificial Potential Field (D-APF) UAV Path Planning Technique for following Ground Moving Targets
Path planning is a vital and challenging component in the support of Unmanned Aerial Vehicles (UAVs) and their deployment in autonomous missions, such as following ground moving target. Few attempts are reported in the literature on multirotor UAV path planning techniques for following ground moving targets despite the great improvement in their control dynamics, flying behaviors and hardware specifications. These attempts suffer several drawbacks including their hardware dependency, high computational requirements, inability to handle obstacles and dynamic environments in addition to their low performance regarding the moving target speed variations. In this paper, a novel dynamic Artificial Potential Field (D-APF) path planning technique is developed for multirotor UAVs for following ground moving targets. The UAV produced path is a smooth and flyable path suitable to dynamic environments with obstacles and can handle different motion profiles for the ground moving target including change in speed and direction. Additionally, the proposed path planning technique effectively supports UAVs following ground moving targets while maneuvering ahead and at a standoff distance from the target. It is hardware-independent where it can be used on most types of multirotor UAVs with an autopilot flight controller and basic sensors for distance measurements. The developed path planning technique is tested and validated against existing general potential field techniques for different simulation scenarios in ROS and gazebo-supported PX4-SITL. Simulation results show that the proposed D-APF is better suited for UAV path planning for following moving ground targets compared to existing general APFs. In addition, it outperforms the general APFs as it is more suitable for UAVs flying in environments with dynamic and unknown obstacles
Quantification of the oxygen uptake rate in a dissolved oxygen controlled oscillating jet-driven microbioreactor
BACKGROUND:
Microbioreactors have emerged as a new tool for early bioprocess development. The technology has advanced rapidly in the last decade and obtaining real-time quantitative data of process variables is nowadays state of the art. In addition, control over process variables has also been achieved. The aim of this study was to build a microbioreactor capable of controlling dissolved oxygen (DO) concentrations and to determine oxygen uptake rate in real time.
RESULTS:
An oscillating jet driven, membrane-aerated microbioreactor was developed without comprising any moving parts. Mixing times of ∼7 s, and kLa values of ∼170 h−1 were achieved. DO control was achieved by varying the duty cycle of a solenoid microvalve, which changed the gas mixture in the reactor incubator chamber. The microbioreactor supported Saccharomyces cerevisiae growth over 30 h and cell densities of 6.7 gdcw L−1. Oxygen uptake rates of ∼34 mmol L−1 h−1 were achieved.
CONCLUSION:
The results highlight the potential of DO-controlled microbioreactors to obtain real-time information on oxygen uptake rate, and by extension on cellular metabolism for a variety of cell types over a broad range of processing conditions. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry
mRNA vaccines manufacturing: Challenges and bottlenecks
Vaccines are one of the most important tools in public health and play an important role in infectious diseases control. Owing to its precision, safe profile and flexible manufacturing, mRNA vaccines are reaching the stoplight as a new alternative to conventional vaccines. In fact, mRNA vaccines were the technology of choice for many companies to combat the Covid-19 pandemic, and it was the first technology to be approved in both United States and in Europe Union as a prophylactic treatment. Additionally, mRNA vaccines are being studied in the clinic to treat a number of diseases including cancer, HIV, influenza and even genetic disorders. The increased demand for mRNA vaccines requires a technology platform and cost-effective manufacturing process with a well-defined product characterisation. Large scale production of mRNA vaccines consists in a 1 or 2-step in vitro reaction followed by a purification platform with multiple steps that can include Dnase digestion, precipitation, chromatography or tangential flow filtration. In this review we describe the current state-of-art of mRNA vaccines, focusing on the challenges and bottlenecks of manufacturing that need to be addressed to turn this new vaccination technology into an effective, fast and cost-effective response to emerging health crises
Efectos de la sal sobre la solubilidad y las propiedades emulsionantes de la caseÃna y sus hidrolizados trÃpticos
This work reports an investigation about the effect of NaCl addition (0.02 mol/L) on some functional properties of casein(CA) and its tryptic hydrolysates (TH). The solubility, the emulsifying capacity (EC), the emulsifying activity index(EAI) and the emulsion stability (ES) were determined at two pH values (4.0 and 5.0). The results showed that thisprocedure was benefi cial for the solubility of CA and TH, being more intense at pH 5.0 and 4.0, respectively. Also, apositive effect of NaCl addition was observed for CA and TH, at both pH values, and the best results for both sampleswere achieved at pH 5.0. The ES was slightly affected by the presence of salt and only for some samples of CA andTH it was increased. Contrarily, the EAI values of casein were reduced with the addition of NaCl at pH 4.0 and 5.0,while those of TH were positively affected by this treatment at both pH values.En este trabajo se presentan los resultados de una investigación sobre los efectos de la adición de NaCl (0,02 mol/L)sobre algunas propiedades funcionales de la caseÃna (CA) y de sus hidrolizados trÃpticos (TH). Se determinaron lasolubilidad, la capacidad emulsionante (CE), el Ãndice de actividad emulsionante (IAE) y la estabilidad de la emulsión(EE) con dos valores de pH (4,0 y 5,0). Los resultados demostraron que el procedimiento era benefi cioso parala solubilidad de CA y TH, siendo más intensa con pH 5,0 y 4,0, respectivamente. También se observó un efectopositivo de la adición de NaCl en CA y TH, con ambos valores de pH, consiguiéndose los mejores resultados conpH 5,0. La EE se vio ligeramente afectada por la presencia de sal, y sólo aumentó en algunas muestras de CA yTH. Por el contrario, los valores del IAE de la caseÃna se redujeron al añadir NaCl con pH 4,0 y 5,0, mientras quelas de TH se vieron afectadas positivamente por este tratamiento con ambos valores de pH
Flocculation on a chip: a novel screening approach to determine floc growth rates and select flocculating agents
Flocculation is a key purification step in cell-based processes for the food and pharmaceutical industry
where the removal of cells and cellular debris is aided by adding flocculating agents. However, finding the
best suited flocculating agent and optimal conditions to achieve rapid and effective flocculation is a nontrivial
task. In conventional analytical systems, turbulent mixing creates a dynamic equilibrium between floc
growth and breakage, constraining the determination of floc formation rates. Furthermore, these systems
typically rely on end-point measurements only. We have successfully developed for the first time a microfluidic
system for the study of flocculation under well controlled conditions. In our microfluidic device
(μFLOC), floc sizes and growth rates were monitored in real time using high-speed imaging and computational
image analysis. The on-line and in situ detection allowed quantification of floc sizes and their growth
kinetics. This eliminated the issues of sample handling, sample dispersion, and end-point measurements.
We demonstrated the power of this approach by quantifying the growth rates of floc formation under forty
different growth conditions by varying industrially relevant flocculating agents (pDADMAC, PEI, PEG), their
concentration and dosage. Growth rates between 12.2 μm s−1 for a strongly cationic flocculant (pDADMAC)
and 0.6 μm s−1 for a non-ionic flocculant (PEG) were observed, demonstrating the potential to rank flocculating
conditions in a quantitative way. We have therefore created a screening tool to efficiently compare
flocculating agents and rapidly find the best flocculating condition, which will significantly accelerate early
bioprocess development
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