‘There is no choice apart from antibiotics…’: qualitative analysis of views on urinary infections in pregnancy and antimicrobial resistance

Background: Antimicrobial resistance (AMR) is a health risk as it can lead to life-threatening infections. There has been a rise in resistant urinary tract infections (UTIs) which is the most common infection in pregnancy. This can be challenging in pregnancy due to the additional need to safeguard foetal development. The study's aim was to explore views about AMR in women who experienced UTIs in pregnancy. Design: Fifteen semi-structured interviews were conducted in the UK and analysed using thematic analysis. Results: Results highlighted two themes: conceptualization of AMR and pregnancy as a deviation from the norm, with an overarching theme of ‘self-efficacy’. Results show that participants were concerned about AMR but uncertain about the effect on society compared to individual's taking antibiotics and about completing antibiotic courses. Participants reported an unsparing use of antibiotics was justified in pregnancy, and behaviours like drinking adequate water were ineffective at preventing UTIs. In summary, women had low self-efficacy regards tackling AMR and managing their health. Conclusion: Misconceptions about how AMR affects society vs the individual translated into viewing it as a future problem to be tackled by the health-care sector. Consequently, AMR requires reconceptualization as a current problem requiring collective action. This research also indicates women endorse a biomedical model of UTIs in pregnancy which attributes resolving illness to interventions such as medicines, implying an automatic reliance on antibiotics. Subsequently, there is a need for self-efficacy by focusing on a behavioural model which emphasizes behaviours for infection prevention, thus reducing the need for antibiotics

Comparison of two model frameworks for fiber dispersion in the elasticity of soft biological tissues

This study compares two models that are used to describe the elastic properties of fiber-reinforced materials with dispersed fibers, in particular some soft biological tissues such as arterial walls and cartilages. The two model approaches involve different constitutive frameworks, one being based on a generalized structure tensor (GST) and the other on the method of angular integration (AI). By using two representative examples, with the same number of parameters for each model, it is shown that the predictions of the two models are virtually identical for a significant range of large deformations, which contradicts conclusions contained in several papers that are based on faulty analysis. Additionally, each of the models is fitted to sets of uniaxial data from the circumferential and axial directions of the adventitia of a human aorta, both models providing excellent agreement with the data. While the predictions of the two models are comparable and exclusion of compressed fibers can be accommodated by either model, it is well known that the AI model requires more computational time than the GST model when used within a finite element environment, in particular if compressed fibers are excluded

Abnormal long wave dispersion phenomena in a slightly compressible elastic plate with non-classical boundary conditions

A two parameter asymptotic analysis is employed to investigate some unusual long wave dispersion phenomena in respect of symmetric motion in a nearly incompressible elastic plate. The plate is not subject to the usual classical traction free boundary conditions, but rather has its faces fixed, precluding any displacement on the boundary. The abnormal long wave behaviour results in the derivation of non-local approximations for symmetric motion, giving frequency as a function of wave number. Motivated by these approximations, the asymptotic forms of displacement components established and long wave asymptotic integration is carried out

Hyperelastic cloaking theory: Transformation elasticity with pre-stressed solids

Transformation elasticity, by analogy with transformation acoustics and optics, converts material domains without altering wave properties, thereby enabling cloaking and related effects. By noting the similarity between transformation elasticity and the theory of incremental motion superimposed on finite pre-strain it is shown that the constitutive parameters of transformation elasticity correspond to the density and moduli of small-on-large theory. The formal equivalence indicates that transformation elasticity can be achieved by selecting a particular finite (hyperelastic) strain energy function, which for isotropic elasticity is semilinear strain energy. The associated elastic transformation is restricted by the requirement of statically equilibrated pre-stress. This constraint can be cast as \tr {\mathbf F} = constant, where $\mathbf{F}$ is the deformation gradient, subject to symmetry constraints, and its consequences are explored both analytically and through numerical examples of cloaking of anti-plane and in-plane wave motion.Comment: 20 pages, 5 figure

Modeling of fibrous biological tissues with a general invariant that excludes compressed fibers

Dispersed collagen fibers in fibrous soft biological tissues have a significant effect on the overall mechanical behavior of the tissues. Constitutive modeling of the detailed structure obtained by using advanced imaging modalities has been investigated extensively in the last decade. In particular, our group has previously proposed a fiber dispersion model based on a generalized structure tensor. However, the fiber tension–compression switch described in that study is unable to exclude compressed fibers within a dispersion and the model requires modification so as to avoid some unphysical effects. In a recent paper we have proposed a method which avoids such problems, but in this present study we introduce an alternative approach by using a new general invariant that only depends on the fibers under tension so that compressed fibers within a dispersion do not contribute to the strain-energy function. We then provide expressions for the associated Cauchy stress and elasticity tensors in a decoupled form. We have also implemented the proposed model in a finite element analysis program and illustrated the implementation with three representative examples: simple tension and compression, simple shear, and unconfined compression on articular cartilage. We have obtained very good agreement with the analytical solutions that are available for the first two examples. The third example shows the efficacy of the fibrous tissue model in a larger scale simulation. For comparison we also provide results for the three examples with the compressed fibers included, and the results are completely different. If the distribution of collagen fibers is such that it is appropriate to exclude compressed fibers then such a model should be adopted