Beyond the freedom to build: Long-term outcomes of Elemental’s incremental housing in Quinta Monroy

In 2003, the Chilean architecture firm Elemental began to revisit the idea of partially completed housing harnessing the productive capacities of the informal process within a more formal framework. The Quinta Monroy project in the northern Chilean city of Iquique was the first such project and involved the in-situ replacement of an informal settlement. The desire of residents was for a middle-class house that was beyond the scope of their budget or the subsidy. The Elemental project at Quinta Monroy comprised 93 expandable houses designed in parallel buildings and organized in four courtyards aiming to promote community interaction and maintain neighbors’ affinities. This paper investigates the process of housing adaptation through self-construction twelve years after the residents received their homes in 2005. The strategy to promote resident-driven expansions has been successful as 92 out of 93 households expanded their homes. The most significant concerns focused on the deterioration of living standards due to progressive and uncontrollable extensions which might have significant impacts on the settlement development. The findings from this paper focus on the neighbors’ negotiations for housing extensions and the risk of the re-creation of precarious living environments evidencing limitations for unassisted or spontaneous incremental schemes of housing development.

Reverse Coarsening and the Control of Particle Size Distribution through Surfactant

The minimization of surface area, as a result of the minimization of (positive) surface energy, is a well-known driving force behind the spontaneous broadening of (nano) particle size distribution. We show that surfactant molecules binding to particle surfaces effectively decrease the surface energy and may change its sign. In this case, contrary to the expected broadening behavior, a minimum of free energy is achieved at the maximum surface area for all particles, i.e., when the particles are identical. Numerical simulations based on the classical Lifshitz–Slyozov–Wagner theory with surfactant-induced surface energy renormalization confirm the collapse of the particle size distribution. As the particle size evolution is much slower than particle nucleation and growth, the manipulation of surface energy with in-situ replacement of surfactant molecules provides a method for controlling particle size distribution with great potential for creating mono-disperse nanoparticles, a key goal of nanotechnology.

Systematic Review and Meta: Analysis of Aortic Graft Infections following Abdominal Aortic Aneurysm Repair

Introduction. Aortic graft infection (AGI) is a rare complication following AAA repair and is associated with high morbidity and mortality. Management is variable, and there are no evidence-based guidelines. The aim of this study was to systematically review and analyse management options for AGI. Methods. Data was collected between July and August 2018. A full HDAS search was conducted on the following databases: MEDLINE, EMBASE, CINAHL, and PUBMED. Meta-analysis was conducted using RevMan 5 software. Results. 1,365 patient outcomes were assessed (10 cohort studies and 12 comparative studies). The most common treatment was in situ replacement of the graft (ISR) followed by extra-anatomical replacement (EAR). Various grafts were used for ISR, such as fresh/cryopreserved allograft, venous graft, and prosthetic grafts. No graft material was shown to be superior. Axillobifemoral graft was the commonest type of EAR used. In the majority of cohort studies, ISR was the main treatment for AGI. There was no significant difference in the overall mortality rate (ISR n=70/176 vs. EAR n=47/126, OR 0.93 [95% CI 0.36-2.36], P=0.87). Graft occlusion rate was significantly lower in the ISR group vs. the EAR group (n=14/115 vs. n=29/60 OR 0.16 [95% CI 0.07-0.36], P<0.001). There was no significant difference in the amputation rate between the surgical treatments (ISR n=9/141 vs. EAR n=8/82, OR 0.75 [95% CI 0.07-8.39], P=0.82). Discussion. In situ replacement is the preferred method of treatment as it had lower rates of occlusion. Further strong evidence is required, such as a multicentre trial to establish a management pathway for the condition.

Electrochemical synthesis of tin plasmonic dendritic nanostructures with SEF capability through in situ replacement

Dendrite nanostructures with noble metals, such as Au, silver and tin, act as plasmonic substrates with excellent potential in enhanced fluorescence technology.

In situ replacement of Cu-DEN: an approach for preparing a more noble metal nanocatalyst for catalytic use

The advantage of dendritic monodisperse macromolecules’ dual templating ability was useful in the formation of silica-supported copper nanoparticles Cun@SiO2NPs.