Toward a fannish methodology: Affect as an asset

Fan studies is a multifaceted discipline that developed from widely different fields of research, resulting in a great variety of methodological approaches. A recurring issue in discussions on methodology in fan studies is the tension between the researchers' attachment to the phenomenon they are studying and the more detached, critical role of a researcher. The double position as both a participant in and observer of the communities that they are researching has led to valuable discussions about reflexivity and positionality in fan studies methodologies. Indeed, the double position of fan and researcher can inform and enrich research by bringing fannish practices and sensibilities to research projects. This tension between attachment to and detachment from the field influences the research process, leading to ethical challenges that acafans must face as a result of their dual positionality. Drawing on affect theory, and reflecting on our own research experiences from an autoethnographic perspective, we show how fannish attachment to the subject-object of study can be a driving force—a resource rather than an impediment to good research. An affective turn in methodology could improve knowledge not only within the field of fan studies but in the social sciences in general.publishedVersio

Optimisation and enhancement of a liposomal delivery system

Polymethyl methacrylate (PMMA) bone cement is commonly used for implant fixation in total joint replacement surgery (TJR), for the treatment of end stage arthritis. The use of antibiotic loaded bone cement (ALBC) is well-established in the prevention of post-surgical infections. Currently, elution of antibiotics from ALBCs occurs in a biphasic profile, with a high initial burst release within the first hours of application, followed by release of sub-inhibitory concentrations over long periods of time. Due to the inability of ALBCs to release clinically effective concentrations of antibiotic over an extended time-period, infections are still a major challenge; moreover, sub-inhibitory antibiotic release may increase the potential for antimicrobial resistance. The aim of this study was to develop and test a new bone cement formulation with optimised sustained antibiotic release, whilst maintaining the mechanical properties of the commercial bone cement. A liposomal bone cement delivery system containing gentamicin sulfate was produced and validated. The liposomal bone cement released a lower mass quantity of gentamicin than commercial ALBC; however, it released a higher percentage of its total incorporated gentamicin content compared to the commercial ALBC, whilst maintaining the antimicrobial efficacy and the mechanical properties of the commercial bone cement. Fluorescent labelled liposomes were used to determine that no measurable quantity of lipid was released from the bone cement. A freeze-dried liposomal formulation was investigated as a means to make the liposomal bone cement a more commercially feasible product. Gentamicin loaded liposomes were freeze-dried and incorporated into bone cement at gentamicin base concentrations of 0.15% w/w - 0.60% w/w of the PMMA bone cement. Whilst these cements showed improved antimicrobial properties, antibiotic release was generally below the limit of detection and mechanical properties were only maintained for the cement containing 0.15% w/w gentamicin. The process was also relatively inefficient, with freeze-drying causing a reduction in lipid and gentamicin content to around half of the initial mass quantities used. Given the limited functionality of the freeze-dried formulation and the commercial impracticality of the non-freeze-dried liposomal bone cement, alternative bone cement formulations were investigated. ALBC containing different mass quantities of hydrophilic (lactose) and hydrophobic (magnesium stearate) additives at concentrations of 10% w/w - 25% w/w of the PMMA bone cement were prepared. Cement containing lactose, released much higher mass quantities of gentamicin than the commercial ALBC and the magnesium stearate cements, although the magnesium stearate cements had a more gradual drug release profile. All cements containing additives had comparable antimicrobial properties to the commercial ALBC, however, the mechanical properties were only maintained for the 10% w/w lactose cement. Since magnesium stearate cements had a more extended drug-release profile, magnesium stearate was used to dry particle coat gentamicin sulfate using different mixing methods of varying shear (tumble mixer, pestle and mortar, ball mill). All bone cements made from dry powder coated gentamicin sulfate, released a similar mass of gentamicin, which was significantly lower than the gentamicin dose released in the commercial ALBC. Antimicrobial activity was maintained, and mechanical properties were comparable to the commercial ALBC. This research has shown that incorporating liposomal antibiotic formulations in bone cements, in a manner that is commercially feasible, is extremely challenging. Whilst the use of liposomes can improve the drug release profile, the manufacturing process can result in significant loss of the active ingredient. Dry particle coating of gentamicin, using small mass quantities of magnesium stearate, could be used as an alternative approach to modify the drug release profile from bone cement, however, further investigation is required to optimise parameters such as mixing method, particle size and type of guest particle, and to establish the potential impact of this approach on toxicity and cement longevity

Electrodeposition of Fe-Sn from the chloride-based electrolyte

The conditions for electrodeposition of Fe-Sn alloys from a novel, environmentally friendly, ferrous chloride-based electrolyte were studied. The influence of the pH on the electrolyte stability and deposit stoichiometry was studied and discussed. Anodic stripping voltammetry (ASV), XRD and SEM/EDX were used to characterise the electrodeposited phases. The results from ASVs indicated the possibility to deposit at least two different phases at high overpotentials. Hull cell depositions in an electrolyte with a Sn to Fe ratio 1:1 and a pH value of 2.8 showed regular deposition of Fe-Sn. Fe-rich deposits (54.84 at.-%) were obtained from an electrolyte with Sn to Fe ratio 1:10. The XRD results were compatible with the electrochemical investigations. In all studied samples β-Sn, FeSn2 and Fe5Sn3 were detected. The presence of ferromagnetic Fe5Sn3 was not influenced by the Sn to Fe ions ratio in the electrolyte

Thermal Conductivity Measurements with Galvanic Metallization Lines on Porosified LTCC Applying the 3-Omega Technique

AbstractThe reduction of the thermal conductivity of low temperature co-fired ceramics (LTCC) caused by a porosification process originally developed for the local modification of the permittivity is determined by the 3ω measurement technique. Therefore, metallization lines of small width down to 20μm are applied by galvanic pulse plating onto the roughened LTCC surface. By this deposition technology it is possible, to cover the pores without any depth penetration. Compared to the ‘as fired’ state, a reduction in thermal conductivity of up to 70% is measured independent of the LTCC type

Comparative morphology of the mouthparts of the megadiverse South African monkey beetles (Scarabaeidae: Hopliini): feeding adaptations and guild structure

Although anthophilous Coleoptera are regarded to be unspecialised flower-visiting insects, monkey beetles (Scarabaeidae: Hopliini) represent one of the most important groups of pollinating insects in South Africa’s floristic hotspot of the Greater Cape Region. South African monkey beetles are known to feed on floral tissue; however, some species seem to specialise on pollen and/or nectar. The present study examined the mouthpart morphology and gut content of various hopliine species to draw conclusions on their feeding preferences. According to the specialisations of their mouthparts, the investigated species were classified into different feeding groups. Adaptations to pollen-feeding included a well-developed, toothed molar and a lobe-like, setose lacinia mobilis on the mandible as well as curled hairs or sclerotized teeth on the galea of the maxillae. Furthermore, elongated mouthparts were interpreted as adaptations for nectar feeding. Floral- and folial-tissue feeding species showed sclerotized teeth on the maxilla, but the lacinia was mostly found to be reduced to a sclerotized ledge. While species could clearly be identified as floral or folial tissue feeding, several species showed intermediate traits suggesting both pollen and nectar feeding adaptations. Mismatches found between mouthpart morphology and previously reported flower visiting behaviours across different genera and species requires alternative explanations, not necessarily associated with feeding preferences. Although detailed examinations of the mouthparts allowed conclusions about the feeding preference and flower-visiting behaviour, additional morphological and behavioural investigations, combined with greater taxon sampling and phylogenetic data, are still necessary to fully understand hopliine host plant relationships, related to monkey beetle diversity

Pripravljanje sekundarnih amina redukcijom Schiffovih baza. II. O furfuriliden- i furfuril-o-anisidinu

Nastavljajuci pokuse pripravljanja sekundarnih (a-furfuril)-arilamina, priredili smo do sada neopisani furfuriliden-o-anisidin (I), iz kojega je redukcijom s pomocu magnezija i metanola dobiven furfuril-o-anisidin (III) s 57 %-tnim iskoristenjem

Effect of hirtisation on the roughness and fatigue performance of porous titanium lattice structures

Additive manufacturing (AM) has enabled the fabrication of extremely complex components such as porous metallic lattices, which have applications in aerospace, automotive, and in particular biomedical devices. The fatigue resistance of these materials is currently an important limitation however, due to manufacturing defects such as semi-fused particles and weld lines. Here Hirtisation$^\circledR$ is used for post-processing of Ti-6Al-4V lattices, reducing the strut surface roughness (Sa) from 12 to 6 $\mu$m, removing all visible semi-fused particles. The evenness of this treatment in lattices with $\rho /\rho_{s}$ up to 18.3% and treatment depth of 6.5 mm was assessed, finding no evidence of reduced effectiveness on internal surfaces. After normalising to quasi-static mechanical properties to account for material losses during hirtisation (34-37% reduction in strut diameter), the fatigue properties show a marked improvement due to the reduction in surface roughness. Normalised high cycle fatigue strength ($\sigma_{f,10^{6}}/\sigma_{y}$) increased from around 0.1 to 0.16-0.21 after hirtisation, an average increase of 80%. For orthopaedic implant devices where matching the stiffness of surrounding bone is crucial, the $\sigma_{f}/E$ ratio is a key metric. After hirtisation the $\sigma_{f}/E$ ratio increased by 90%, enabling design of stiffness matched implant materials with greater fatigue strength. This work demonstrates that hirtisation is an effective method for improving the surface roughness of porous lattice materials, thereby enhancing their fatigue performance.Comment: 10 figure

Electrodeposition of Soft Magnetic Fe-W-P Alloy Coatings from an Acidic Electrolyte

Fe-W-P coatings were deposited from a newly developed electrolytic bath. The effect of plating parameters, such as electrolyte current density and pH has been studied. It was found that\ua0the pH has a very strong effect on the phosphorous content of the coatings. Metallic-like, non-powdery alloys of Fe-W-P deposits with no cracks (lowly stressed) can be obtained at a lower pH\ua0(<3), exhibiting high phosphorus (up to 13 at.%) and low tungsten (6 at.%) contents. At a higher pH\ua0(>3), the composition changes to low phosphorus and high tungsten content, showing a matte,\ua0greyish, and rough surface. The applied current density also influences the morphology and the\ua0amount of phosphorous content. The deposits showed an amorphous structure for all samples with\ua0soft ferromagnetic properties