Alternating tangential flow (ATF) filtration has been used with success in the Biopharmaceutical industry as a lower shear technology for cell retention perfusion cultures. The ATF system is different than filtration; however, that reverse once per cycle means to minimize fouling. Few studies have reported literature evaluates and how key variables affect rate at which filters foul. In this study, an experimental setup was devised allowed determination of time it took fouling occur given...

This research focuses on investigating the use of common biofuel grasses to assess their potential as agents long-term remediation contaminated soils using lead a model heavy metal ion. We present evidence demonstrating that switch grass and Timothy may be potentially useful for phytoremediation describe novel techniques track remove contaminants from inception product. Enzymatic digestion thermochemical approaches are being used convert this lignocellulosic feedstock into product (sugars,...

While CAR-T therapy is a growing and promising area of cancer research, it limited by high cost the difficulty consistently culturing T-cells to therapeutically relevant concentrations ex-vivo. Cytokines IL-2, IL-7 IL-15 have been found stimulate growth T cells, however, optimized combination these three cytokines for cell proliferation unknown. In this study, we designed an integrated experimental modeling approach optimize cytokine supplementation rapid expansion in clinical applications....

CFD (computational fluid dynamics) has been used to model upstream bioprocessing steps such as fermentation and homogenization. The focus of these studies oftentimes characterize single-phase (liquid) flow hydrodynamic shear. In the actual operations, however, there are at least two phases (cells liquid) present. bioreactor, gas bubbles constitute a third phase. More recent models have considered momentum mass transfer that occurs between phases. This review summarizes from biochemical...

Abstract A mathematical model is presented for predicting the shear‐induced decrease in live cells occurring over time during tangential flow filtration. The uses a cell death rate constant ( K ) and considers effects of rate, solution viability, filtration system volumes dimensions. Single pass recycle capillary experiments with solutions high (93%), medium (87%), low (70%) viability were run, where maximum laminar shear stress ranged from 10– 300 Pa, to validate determine constants. values...

A Computational Fluid Dynamic (CFD) model of flow in a high-pressure homogenizing valve (APV Gaulin 30CD) was developed with the Fluent software. The 2D consists an unstructured hexagonal mesh, dense regions high gradients. (single-phase) modeled as laminar upstream and channel (gap) turbulent downstream exit. Applying realizable kappa-epsilon turbulence model, CFD accurately predicted effect gap space on fluid dynamic conditions (inlet pressure gradient) (impact pressure) for standard...

A battery of eight auditory discrimination tests was designed to measure the primary dimension along which simple and complex sounds can be discriminated. Six tests, selected on basis data collected in an earlier 22-subtest version [D. M. Johnson, J. K. Jensen, C. S. Watson, Acoust. Soc. Am. Suppl. 1 67, S52 (1980)], use tonal stimuli: frequency, intensity, duration discrimination, using single tones, rhythm, temporal order, tonal-pattern multitone sequences. Two additional employ speech...

Expanded-bed adsorption (EBA) can be particularly useful in protein recovery from high-cell-density fermentation broth where conventional methods for harvest and clarification, such as continuous centrifugation depth filtration, demand long processing times are associated with high costs. In this work, the use of next-generation high-particle-density EBA adsorbents, including two mixed-mode resins, direct capture a recombinant expressed yeast at cell densities is evaluated. Using classical...

Within the last decade, fully disposable centrifuge technologies, fluidized-bed centrifuges (FBC), have been introduced to biologics industry. The FBC has found a niche in cell therapy where it is used collect, concentrate, and then wash mammalian product while continuously discarding centrate. goal of this research was determine optimum conditions for recovery live cells, develop mathematical model that can assist with process scaleup. Cell losses occur during bed formation via flow...

Optimization of the alkaline lysis (P2) and neutralization (N3) steps in recovery DNA plasmids was pursued. Experiments were conducted at test‐tube 5‐litre scales with 3 kb (pUC18) 20 (pQR150) plasmids. The scale degree mixing/shear did not affect optimum yield supercoiled plasmid during P2 step, but effect time required for to be achieved. This large longer (8–9 min), especially when a low‐shear impeller used. Also, reached maximum purity (percentage form) simultaneously minimum. As...

Abstract Considerable debate has occurred over the use of hydrofoil impellers in large‐scale fermentors to improve mixing and mass transfer highly viscous non‐Newtonian systems. Using a computational fluid dynamics software package (Fluent, version 4.30) extensive calculations were performed study effect impeller speed (70–130 rpm), broth rheology (value power law flow behavior index from 0.2 0.6), distance between cooling coil bank fermentor wall (6–18 in.) on near perimeter large (75‐m 3 )...

Sigma theory is commonly used to predict the conditions that result in half of entering particles being retained within a continuous-flow centrifuge. In this research, 2D computational fluid dynamics (CFD) model flow through tubular bowl centrifuge (Sharples, 5 cm radius) was developed with Fluent software. A volume-of-fluid (VOF) approach for most simulations track motion liquid and gas phases, because location gas/liquid interface depends on operating conditions. The CFD results indicate...

The ambr bioreactors are single‐use microbioreactors for cell line development and process optimization. With operating conditions large‐scale biopharmaceutical production properly scaled down, such as the ambr15™ can potentially be used to predict effect of changes modified media or different lines. While there have been some recent studies evaluating technology a scale‐down model fed‐batch operations, little has reported semi‐continuous continuous operation. Gassing rates dilution in were...

Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within rotary pump can adversely affect product yield or purity during, example, cell concentration via cross-flow filtration. In this research, CHO grown 20-L bioreactors were fed both single pass and recycle experiments conducted at different RPMs "slip" conditions. The results indicate that slip flow rate more severely impacts viability than RPM. A novel mathematical...

Current theories of aging suggest that at least part the decline in performance on psychophysical tasks, commonly observed older subjects, may be result their becoming more cautious about sensory decisions. This conclusion has been supported by experiments which criterion index, β, from signal detection theory is shown to higher (indicating a strict criterion) for subjects. A weight-discrimination experiment reported failed replicate earlier results; subjects' criteria were same or lax than...