3D extrusion of multi-biomaterial lattices using an environmentally informed workflow

The conventional building material palette has been proven limited in terms of adaptability to our current environmental challenges. Innovations in computational design and digital manufacturing have supported the broadening of biomaterial applications as an alternative. While biomaterials are characteristically responsive to stimuli such as temperature and humidity, their unpredictable behaviour is a hurdle to standardization and architectural utilisation. To examine the nexus between material formulation, computation and manufacturing, multi-biomaterial lattice structures were produced through an environmentally informed workflow. Customized biomaterial development resulted in three candidate biopolymer blends with varying levels of hydro-responsiveness and transparency. The computational strategy included a machine learning clustering algorithm to customise results and dictate material distribution outputs. To test the workflow, environmental data of solar radiation exposure and solar heat gain from a specific location was used to inform the material deposition via pneumatic extrusion for the design and digital fabrication of a deformation-controlled prototype of 350 mm × 350 mm. This led to a series of multi-biomaterial wall panel components that can be applied at architectural scale. In future, these techniques can support the incorporation of living elements to be embedded within the built environment for truly animate architecture.     

CD28null and Regulatory T Cells Are Substantially Disrupted in Patients with End-Stage Renal Disease Due to Diabetes Mellitus

Background: End-stage renal disease (ESRD) is associated with alterations in T-cell immunity, including increased CD28null and reduced regulatory T cells (Tregs). However, whether immune disturbances are due to ESRD or primary disease is not yet clear. As diabetes mellitus is the leading cause of ESRD, we evaluated its impact on the immune profile of ESRD patients. Methods: CD28null, Tregs, and natural killer cells were initially analyzed by flow cytometry in 30 predialysis ESRD patients due to diabetes (DM), 30 non-DM (NDM), and 25 healthy controls. Measurements were repeated after 6 months on hemodialysis (HD) or peritoneal dialysis (CAPD). Results: The percentage of CD4 + CD28null cells, CD8 + CD28null cells, and Tregs showed significant differences in DM, NDM, and controls; mean rank 33.71 vs. 25.68 vs. 18.88, p = 0.006, 37.79 vs. 28.82 vs. 17.08, p = 0.008, and 20.79 vs. 26.12 vs. 41.33, p = 0.001, respectively. DM vs. NDM had increased CD4 + CD28null and CD8 + CD28null cells, 11.5% (1.5%–24%) vs. 4.1% (0–42.3%), p = 0.02 and 61.3% (24%–76%) vs. 43% (5.7%–85%), p = 0.04, respectively. After 6 months on HD but not CAPD, DM showed a significant further increase in CD4 + CD28null cells, from 30 (14–100) to 52.7 (15–203), p = 0.02; and CD8 + CD28null cells, from 137 (56–275) to 266 (103–456), p = 0.01. Conclusions: Diabetes mellitus affects T-cell subtypes even at predialysis stage, though changes become more prominent after commencement on HD.     

Light induced Nitrosomonas inhibition

The purpose of this study was to evaluate and verify the impact of light exposure on an enriched Nitrosomonas culture. Resting cells maintained under aerobic conditions without an exogenous ammonium-nitrogen source were fully inhibited within a 10 min period of ambient light contact (i.e. fluorescent and indirect natural room light). These cells were, however, protected against this inhibitive phenomenon during active respiration periods and during anoxic exposure conditions. Recovery, albiet partial, from such light induced inhibition was initiated after a “dark” contact period of approx. 2.5–3 h without exogenous ammonium presence. Research involving enriched or pure Nitrosomonas cultures (e.g. batch bioassay testing) should consequently be completed under environmental conditions designed to obviate this problem.     

Dissolution of aluminosilicate minerals and by-products in alkaline media

In this work, the leaching behaviour of six aluminosilicate industrial minerals and by-products (kaolin, metakaolin, fly ash, natural pozzolana from Milos, zeolite and furnace slag) in alkaline solutions is investigated. The variables studied are the kind of alkali metal (K, Na), the concentration of the alkaline solution (2.5, 5 and 10 M) and the time of dissolution (5, 10 and 24 h). The solid residue after the leaching was examined by means of XRD and FTIR. As it is concluded, the leaching ability of Al and Si is according to the following descending order: Metakaolin > Zeolite > Slag > Fly Ash > Pozzolana > Kaolin. The extent of dissolution is higher in NaOH than in KOH solutions, especially when the most reactive materials are concerned. Finally, Si and Al seem to have a synchronized leaching behaviour in both alkaline solutions.     

Retention of trans-anethole by gelatine and starch matrices

The retention of trans-anethole by gelatine gels (2.5, 5, 10 and 20 wt.%) and starch solutions (10 and 20 wt.%) was investigated by Static Headspace Gas Chromatography. Prior to analysis the samples were left to equilibrate for 24 h at 5 and 37 °C, respectively. Higher partition coefficients were obtained at the higher temperature, probably due to the increased volatility of the aroma compound. The effect of freeze drying of the matrices in the presence of trans-anethole was also evaluated. No significant effect on the partition coefficient values was observed. However, the changes in the nature and the concentration of the matrix were not of great importance on the retention of trans-anethole.     

Compression of gellan gels. Part I: effect of salts

Gellan gels, in the presence of potassium and calcium ions and their mixtures, were tested using large deformation compression experiments. Characterisation was based on stress and strain at failure along with Young’s modulus. Samples prior to compression were refrigerated at 5 °C for 1, 2 and 24 h. In the case of potassium, the strongest gel was obtained for a cation concentration of 80 mm . Increasing concentrations of calcium resulted in decreased gel strength. Brittleness values for potassium and calcium gels fluctuated around ～0.5 and ～0.3 respectively. The strength for both, potassium and calcium, gels did not increase significantly over time. For each cation, Young’s modulus and stress at failure showed the same variation. In the case of mixtures, strength was determined by calcium as its progressive replacement by potassium was actually similar to reducing its concentration. Potassium determined the remaining properties.