Crystallization diagram for antisolvent crystallization of lactose : using design of experiments to investigate continuous mixing- induced supersaturation

This study investigates the effects of key process parameters of continuous mixing-induced supersaturation on the antisolvent crystallization of lactose using D-optimal Design of Experiments (DoE). Aqueous solutions of lactose were mixed isothermally with antisolvents using a concentric capillary mixer. Process parameters investigated were the choice of antisolvent (acetone or isopropanol), concentration of lactose solution, total mass flow rate, and the ratio of mass flow rates of lactose solution and antisolvent. Using a D-optimal DoE a statistically significant sample set was chosen to explore and quantify the effects of these parameters. The responses measured were the solid state of the lactose crystallized, induction time, solid yield and particle size. Mixtures of α-lactose monohydrate and β-lactose were crystallized under most conditions with β-lactose content increasing with increasing amount of antisolvent. Pure α-lactose monohydrate was crystallized using acetone as the antisolvent, with mass flow ratios near 1:1, and near saturated solutions of lactose. A higher resolution DoE was adopted for acetone and was processed using multivariate methods to obtain a crystallization diagram of lactose. The model was used to create an optimized process to produce α-lactose monohydrate and predicted results agreed well with those obtained experimentally, validating the model. The solid state of lactose, induction time, and solid yield were accurately predicted

Rapid testing versus karyotyping in Down's syndrome screening: cost-effectiveness and detection of clinically significant chromosome abnormalities

In all, 80% of antenatal karyotypes are generated by Down's syndrome screening programmes (DSSP). After a positive screening, women are offered prenatal foetus karyotyping, the gold standard. Reliable molecular methods for rapid aneuploidy diagnosis (RAD: fluorescence in situ hybridization (FISH) and quantitative fluorescence PCR (QF-PCR)) can detect common aneuploidies, and are faster and less expensive than karyotyping

Integrin-Alpha IIb Identifies Murine Lymph Node Lymphatic Endothelial Cells Responsive to RANKL

Microenvironment and activation signals likely imprint heterogeneity in the lymphatic endothelial cell (LEC) population. Particularly LECs of secondary lymphoid organs are exposed to different cell types and immune stimuli. However, our understanding of the nature of LEC activation signals and their cell source within the secondary lymphoid organ in the steady state remains incomplete. Here we show that integrin alpha 2b (ITGA2b), known to be carried by platelets, megakaryocytes and hematopoietic progenitors, is expressed by a lymph node subset of LECs, residing in medullary, cortical and subcapsular sinuses. In the subcapsular sinus, the floor but not the ceiling layer expresses the integrin, being excluded from ACKR4+LECs but overlapping with MAdCAM-1 expression. ITGA2b expression increases in response to immunization, raising the possibility that heterogeneous ITGA2b levels reflect variation in exposure to activation signals. We show that alterations of the level of receptor activator of NF-κB ligand (RANKL), by overexpression, neutralization or deletion from stromal marginal reticular cells, affected the proportion of ITGA2b+LECs. Lymph node LECs but not peripheral LECs express RANK. In addition, we found that lymphotoxin-β receptor signaling likewise regulated the proportion of ITGA2b+LECs. These findings demonstrate that stromal reticular cells activate LECs via RANKL and support the action of hematopoietic cell-derived lymphotoxin

Water activity and its prediction: A review

Water activity is a very useful parameter in food preservation. Raoult's law gave a first base in the case of ideal solutions. In 1966, Norrish presented a thermodynamically based equation to predict activity coefficients in confectionery syrups. Later, the Gibbs-Duhem equation was used to produce series of predictive models starting with Ross in 1975. Some apparent refinements have been proposed since then by Caurie, followed by Lilley and Sutton. In this work an analysis of different approaches are discussed with their limits. New directions are also suggested for either a more numerical approach to solve directly the Gibbs-Duhem equation, or a more empirical one, based on the zonotopes