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Long Lasting Insecticidal Nets (LLINs) supplemented with the synergist piperonyl butoxide have been developed in response to growing pyrethroid resistance however their durability in the field remains poorly described. A pragmatic cluster-randomised trial was embedded into Uganda’s 2017-2018 distribution to compare the durability of LLINs with and without PBOA total of 104 clusters were included with each receiving one of four LLIN products, two with pyrethroid+PBO (Olyset Plus and PermaNet 3.0) and two pyrethroid-only (Olyset Net and PermaNet 2.0). Nets were sampled at baseline, 12, and 25 months post-distribution to assess physical condition, chemical content, and bioefficacy. Physical condition was quantified using proportionate Hole Index and chemical content measured using high-performance liquid chromatography. Bioefficacy was assessed with three-minute WHO Cone and Wireball assays using pyrethroid-resistant An. gambiae, with 1hr knockdown and 24hr mortality recorded.There was no difference in physical durability between LLIN products assessed (p=0.644). The pyrethroid content of all products remained relatively stable across timepoints but PBO content declined by 55% (pHere we demonstrate that both Olyset Plus and PermaNet 3.0 are as durable as their pyrethroid-only equivalents and had superior bioefficacy against pyrethroid-resistant An. gambiae. However, the superiority of PBO-LLINs decreased with operational use, correlating with a reduction in total PBO content. This decline in bioefficacy after just two years is concerning and there is an urgent need to assess the durability of PBO LLINs in other settings.

This article will describe a wide variety of materials that have been or may have been used as fills for voids in three-dimensional objects in the Western world. Some of the materials discussed are ancient, and some were the result of 19th-century technical innovation, but all predate the introduction of most of the synthetic polymers. A brief introduction considers the different approaches to restoration of craftspeople working within a trade or craft and those who were menders and restorers, as well as the widespread use of proprietary adhesives and filling materials. A catalog of filling compounds drawn from European and American literature on the subject follows. It includes brief descriptions of such binder and bulking agent combinations as traditional gesso, common materials such as plaster and the “patent plasters,” as well as more complex compounds that harden by chemical reaction. Many of these are little-known today, such as those based on sulfur, water-glass (sodium and potassium silica...

The use of paper or paper fiber in the production of three-dimensional objects seems to have closely followed the spread of papermaking itself: Brief notice of this ancient history is followed by description of papier Mâche as an architectural material from the 17th to the early 19th century, focusing on the mid-18th century, when it appears to have been used most extensively. The practices of the London craftspeople who produced sculptural detail in this medium for domestic use and export are examined as illuminated by the technical examination of papier Mâche in the Miles Brewton House of Charleston, South Carolina, dating from the 1760s. Discussion of the Brewton house material includes the complete rococo-style ceiling in the parlor, the reconstruction of gilded molding based on fragments from the drawing room found in a rat's nest during restoration, and a bas-relief of Apollo and a gilded border in the stair hall that was damaged but largely complete. Restoration of original decorative sche...

The faience of the New Kingdom period is frequently decorated with an expanded palette of red, black, and yellow. This polychrome decoration was often accomplished by inlaying one color of paste into another. The aesthetic success of these inlay techniques reveals a fundamental understanding of the materials' characteristics before, during, and after firing, and knowledge of how to manipulate these characteristics. The goal of this research is to more fully understand ancient Egyptian faience inlay techniques by characterizing the properties of a set of standard reproductions. As the most aesthetically successful reproductions were obtained using pre-fired components, a series of experiments was performed to quantify changes in glaze color, glaze gloss, and depth of glaze penetration upon refiring. Data was gathered from replicated samples and cross-sections using SEM, UV-VIS spectrophotometry, colorimetry, and optical microscopy. Visual comparisons were made between cross-sections of replicated inlays and examples of broken ancient Egyptian faience inlays.

Cyclododecane, a volatile cyclic alkane (C12H24), was recently introduced to the conservation field as a temporary consolidant or masking material with suggested uses in paintings, textile and architectural conservation. In the present study, the waxlike hydrocarbon material was tested for its potential use as a temporary fixative for water-sensitive media on paper using an adaptation of a commercial wax-melting tool. Cyclododecane offered considerable, although not always complete, protection during aqueous treatments performed on media with different degrees of water sensitivity. The hydrocarbon was further investigated as a barrier film for taking molds from objects with porous surfaces that are easily contaminated by residues of the silicone mold materials commonly used. In combination with gum arabic or methylcellulose, this barrier system virtually eliminated the penetration of the silicone oils into the surface of modern flowerpot shards and limestone samples. In both of these applications,...

An apparatus for repairing flat glass with thermosetting resins is described. Small threaded rods inserted through numerous threaded holes in the top surface of a light-box allow fine and repeated adjustments to be made in the level of fragments before adhesive is introduced. Elevation off the surface prevents adhesive from running under edges. The light allows the conservator to monitor resin penetration and the low level of heat aids in curing the resin.

This paper describes a method for treating cupped and blind cleavage and carrying out cosmetic compensation on Hinterglasmalerei which solves many of the problems encountered with previously reported treatments involving solvent relaxation and/or consolidation with synthetic resins. In the treatment described, the severely damaged paint film is transferred off the glass virtually intact, then cleaned and compensated from the front prior to reattachment with a low viscosity epoxy resin.