Cutinase purification on poly(ethylene glycol)–hydroxypropyl starch aqueous two-phase systems

The partition behaviour of cutinase on poly(ethylene glycol) (PEG)–hydroxypropyl starch aqueous two-phase systems was characterized. The effect of molecular mass of PEG, the pH of the system and tie-line length on cutinase partition coefficient and cutinase yield to the top phase was investigated for systems prepared with a purified hydroxypropyl starch (Reppal PES 100) and a crude one (HPS). The effect of the presence of different salts, such as sodium chloride, sodium sulphate and ammonium sulphate, on cutinase partition was also studied. The results lead to the conclusion that aqueous two-phase systems composed of PEG and hydroxypropyl starch are not efficient in the purification of cutinase. In the majority of cases, the partition coefficients were very close to 1, with pH being the factor which affects most cutinase partition. Partition coefficients were significantly improved when salts were added to the systems. For PEG 4000–Reppal PES 100 [at pH 4.0; 0.5 M (NH4)2 SO4], the partition coefficient for cutinase was 3.7, while a value of 12 was obtained for PEG 4000–HPS (at pH 4.0; 1 M NaC1). An isoelectric point (pI ) of 7.8 was confirmed for cutinase by constructing a cross partition graphic from the results obtained in the experiments with different salts. 1998 Elsevier Science B.V. All rights reserved

Stress-crack opening relationship of enhanced performance concrete

Force-deflection responses obtained from three-point bending tests with notched beams of enhanced performance concrete were used to determine, by means of an inverse analysis, the stress at crack initiation, the shape of the stress-crack opening relationship and the fracture energy of this material. This inverse analysis was performed with non-linear finite element software where crack opening and crack propagation were simulated by discrete crack models using interface finite elements. The influence of both the concrete age and the percentage of binder replaced by fly-ash on the fracture parameters was analysed. In the present work, the numerical strategy is described, and the obtained results are presented and analysed.ADI - PABERFIA

Rapid optimization of chromatography operating conditions using a nano- liter scale column on a microfluidic chip with integrated pneumatic valves and optical sensors

Purification of monoclonal antibodies (mAbs) is traditionally achieved by chromatographic separations, which are very robust but require time-consuming optimization on a case-by-case, particularly if a non-affinity step is used. In this context, multimodal chromatography has been explored as a versatile and cost-effective alternative to the established affinity step employed for capturing mAbs. However, selective capture/polishing of a target mAb using such multimodal ligands comes with the need for extensive and time-consuming optimization, due to the multitude of interactions that can be simultaneously promoted in the ligand. In this work, we developed a novel microfluidic platform comprising multimodal chromatography beads inside micro-columns for rapid screening of operating conditions. Sequential liquid insertion in the device was achieved by using integrated pneumatic valves and the chromatographic assays were combined with a signal acquisition module for on-chip fluorescence measurements. Please click Additional Files below to see the full abstract

Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study

Purpose: To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP). Methods: Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed. Results: A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression. Conclusion: In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.info:eu-repo/semantics/publishedVersio