Phospholipid—polymer amphiphile hybrid assemblies and their interaction with macrophages

Recently, the combination of lipids and block copolymers has become an alternative to liposomes and polymersomes as nano-sized drug carriers. We synthesize novel block copolymers consisting of poly(cholesteryl acrylate) as the hydrophobic core and poly(N-isopropylacrylamide) (PNIPAAm) as the hydrophilic extensions. Their successful phospholipid-assisted assembly into vesicles is demonstrated using the evaporation-hydration method. The preserved thermo-responsive property of the lipid-polymer hybrids is shown by a temperature dependent adsorption behaviour of the vesicles to poly(l lysine) coated surfaces. As expected, the vesicle adsorption is found to be higher at elevated temperatures. The cellular uptake efficiency of hybrids is assessed using macrophages with applied shear stress. The amount of adhering macrophages is affected by the time and level of applied shear stress. Further, it is found that shorter PNIPAAm extensions lead to higher uptake of the assemblies by the macrophages with applied shear stress. No inherent cytotoxicity is observed at the tested conditions. Taken together, this first example of responsive lipid-polymer hybrids, and their positive biological evaluation makes them promising nano-sized drug carrier candidates.     

Plasma centrifugation does not influence thrombin-antithrombin and plasmin-antiplasmin levels but determines platelet microparticles count

Introduction

Centrifugation is an essential step for plasma preparation to remove residual elements in plasma, especially platelets and platelet-derived microparticles (PMPs). Our working hypothesis was that centrifugation as a preanalytical step may influence some coagulation parameters.

Materials and methods

Healthy young men were recruited (N = 17). For centrifugation, two protocols were applied: (A) the first centrifugation at 2500 x g for 15 min and (B) at 2500 x g for 20 min at room temperature with a light brake. In protocol (A), the second centrifugation was carried out at 2500 x g for 15 min, whereas in protocol (B), the second centrifugation involved a 10 min spin at 13,000 x g. Thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes concentrations were determined by enzyme-linked immunosorbent assays. PMPs were stained with CD41 antibody and annexin V, and analyzed by flow cytometry method. Procoagulant activity was assayed by the Calibrated Automated Thrombogram method as a slope of thrombin formation (CAT velocity).

Results

Median TAT and PAP concentrations did not differ between the centrifugation protocols. The high speed centrifugation reduced the median (IQR) PMP count in plasma from 1291 (841-1975) to 573 (391-1010) PMP/µL (P = 0.001), and CAT velocity from 2.01 (1.31-2.88) to 0.97 (0.82-1.73) nM/min (P = 0.049). Spearman’s rank correlation analysis showed correlation between TAT and PMPs in the protocol A plasma which was (rho = 0.52, P < 0.050) and between PMPs and CAT for protocol A (rho = 0.74, P < 0.050) and protocol B (rho = 0.78, P < 0.050).

Conclusion

Centrifugation protocols do not influence the markers of plasminogen (PAP) and thrombin (TAT) generation but they do affect the PMP count and procoagulant activity.Key words: cell-derived microparticles, blood coagulation tests, centrifugation, preanalytical phase     

Putting Children at the Centre: Making policy as if children mattered

Abstract

What do we mean when we say we want to put children at the centre of policy? What are the moral justifications for this approach? Has it become harder for us to understand this concept, when in practice paid work has been at the centre? In part confusion arises because the unpaid work of caring for children is invisible until it is marketized. In turn, the underlying problem is that we have forgotten our traditions of egalitarianism and adopted a powerful mindset that is proving to be paralyzing. Exploring New Zealand family policies such as paid parental leave (PPL), early childhood education, child tax credits (CTC) suggests that there is much room for improvement if the needs of children are to come first. But first and foremost we must have a very different, child-centric, colour-blind, non-judgmental change of heart.     

Daycare Staff Emotions and Coping Related to Children of Divorce: A Q Methodological Study

This Q methodological study explores emotional experiences and coping of daycare staff when working with children of divorce and their families. Two main coping strategies among daycare staff were identified: 1) Confident copers, and 2) Non-confident copers. Interviews exemplify the two main experiences. Both groups may struggle with coping in this work. Still, Non-confident copers seem to experience more problems than do Confident copers. Both Confident and Non-confident copers find it difficult to work with parents who argue in front of the children. Accordingly, we suggest tailored education and counseling in this field to increase knowledge and coping among staff, to help them in their work with children of divorce.     

Monitoring bullying behaviours may not enhance principal's awareness of the prevalence

Monitoring bullying behaviours is the key aspect of a successful anti-bullying intervention. Questionnaires among pupils and principals of the same schools were utilised to measure the agreement between pupil-reported frequency and principals' estimations of the prevalence of frequent bullying in the same schools and to identify monitoring methods associated with the best agreement. The correlation between the pupil-reported frequency and the principal's estimate of the prevalence was weak. Two-thirds of the principals estimated the prevalence of frequent bullying in their schools to be four percentage points lower than the prevalence, based on pupils' reports. Questionnaires that were developed and administered by the schools themselves and unspecified monitoring methods were associated with the best agreement between pupils' reports and principals' estimates of the prevalence of frequent bullying. There is a clear need to communicate better the nationally collected data back to schools. It seems that despite the monitoring efforts, school principals were not aware of the prevalence of frequent bullying as perceived by their pupils. Awareness of the problem may require more than just available evidence.     

Balance Among Cognitive Control Processes: A Case Study of a Gifted Youth

This case study analyzed the cognitive strategies of Ethan, a gifted youth, when performing a Stop Signal Task assessing cognitive control processes including response inhibition as well as proactive and reactive adjustments of response. In the case of Ethan, the response inhibition score was biased, revealing that Ethan did not follow the instructions but challenged them and was successful in doing this. Specifically, he made important proactive adjustments, by both slowing down and speeding up (i.e., risk taking) his responses according to the likelihood of the apparition of the stop signal (triggering response inhibition). Ethan’s performance indicated that he perfectly understood the procedure behind the task and completed it according to his own comprehension. Ethan’s results showed that researchers and clinicians must be careful when assessing gifted children and adolescents by using tasks that they cannot defeat.     

Fostering and assessing student critical thinking: From theory to teaching practice

In an age of innovation and digitalisation, critical thinking has become one of the most valued skills in the labour market. This paper shows how teachers can empower students to develop their students' critical thinking. After recalling why critical thinking matters for democracy and the economy, a definition of critical thinking is outlined. Next, a demonstration is given of how the concept critical thinking can be translated and simplified using teacher-friendly rubrics that can support the design or redesign of lesson plans, teacher observations and formative assessment—as well as standardised assessments. In conclusion, the paper argues that critical thinking should be mainstreamed in all subjects in school curricula, and that it leads to deeper understanding of subject matter content.