Predictions of angle dependent tortuosity and elasticity effects on sound propagation in cancellous bone

The anisotropic pore structure and elasticity of cancellous bone cause wave speeds and attenuation in cancellous bone to vary with angle. Previously published predictions of the variation in wave speed with angle are reviewed. Predictions that allow tortuosity to be angle dependent but assume isotropic elasticity compare well with available data on wave speeds at large angles but less well for small angles near the normal to the trabeculae. Claims for predictions that only include angle-dependence in elasticity are found to be misleading. Audio-frequency data obtained at audio-frequencies in air-filled bone replicas are used to derive an empirical expression for the angle-and porosity-dependence of tortuosity. Predictions that allow for either angle dependent tortuosity or angle dependent elasticity or both are compared with existing data for all angles and porosities

Impermeable metal microcapsules for diagnostic/ therapeutic applications

Until recently, small, volatile actives could not be efficiently encapsulated for timescales longer than a few days, due to the inherent porosity of the polymeric membranes used as the capsule shell material. Using electro-less deposition of metals, we have developed a method for preventing undesired loss of encapsulated actives using a simple 3 step process.1 The addition of a continuous metal shell prevents loss of the core into a solvent for the core over a period of 90 days, as opposed to polymeric capsules which lose their entire core in less than 30 minutes under the same conditions. Polymer shell – oil core microcapsules are produced using oil-in-water emulsification followed by co-solvent extraction to precipitate a polymeric shell around the oil core, as first described in the work of Vincent et al.2, 3 Metallic catalytic nanoparticles are then physically adsorbed onto the microcapsule polymeric shells. Subsequently, this nanoparticle coating is used to catalyze the growth of a secondary metallic film.4 Here we investigate an exciting application of these metal microcapsules, as a vehicle for drug delivery, the rationale being that once a material is encapsulated in our capsules it cannot escape, until the capsules are broken by an external trigger. Thus, with a drug molecule that exhibits undesirable side effects trapped in the capsules, we can target the delivery site and fracture the capsules by application of an external force once they arrive at that location, removing the unwanted side effects which normally are associated with, for example, off-target effects of drug delivery in cancer treatment. Previously poly(methyl methacrylate) (PMMA) has been utilized as the polymeric shell. However, in this work we demonstrate that PMMA can be substituted for poly(lactic-co-glycolic acid) (PLGA) a biocompatible and biodegradable polymer suitable for use as a drug carrier. We encapsulate perfluorooctyl bromide (PFOB), a tracer for ultrasound, as our model system, and then follow the steps described previously for growth of the metal shell. We demonstrate that by using acoustic pulsed signals of varying intensity and time intervals, we can control the rupture of our metal capsules in an aqueous environment, to trigger release of PFOB into the external environment. 1. Hitchcock, J. P.; Tasker, A. L.; Baxter, E. A.; Biggs, S.; Cayre, O. J., Long-Term Retention of Small, Volatile Molecular Species within Metallic Microcapsules. Acs Applied Materials & Interfaces 2015, 7 (27), 14808-14815. 2. Dowding, P. J.; Atkin, R.; Vincent, B.; Bouillot, P., Oil Core/Polymer Shell Microcapsules by Internal Phase Separation from Emulsion Droplets. Ii: Controlling the Release Profile of Active Molecules. Langmuir 2005, 21 (12), 5278-5284. 3. Loxley, A.; Vincent, B., Preparation of Poly(Methylmethacrylate) Microcapsules with Liquid Cores. Journal of Colloid and Interface Science 1998, 208 (1), 49-62. 4. Horiuchi, S.; Nakao, Y., Platinum Colloid Catalyzed Etchingless Gold Electroless Plating with Strong Adhesion to Polymers. Surface & Coatings Technology 2010, 204 (23), 3811-3817

Effect of physicochemical properties, pre-processing, and extraction on the functionality of wheat bran arabinoxylans in breadmaking - A review

Arabinoxylan (AX) is an abundant hemicellulose in wheat bran and an important functional component in bakery products. This review compares preprocessing and extraction methods, and evaluates their effect on AX properties and functionality as a bread ingredient. The extraction process results in AX isolates or concentrates with varying molecular characteristics, indicating that the process can be adjusted to produce AX with targeted functionality. AX functionality in bread seems to depend on AX properties but also on AX addition level and interactions with other components. This review suggests that the use of AX with tailored properties together with properly optimized baking process could help increasing the amount of added fiber in bread while maintaining or even improving bread quality

Effect of physicochemical properties, pre-processing, and extraction on the functionality of wheat bran arabinoxylans in breadmaking – A review

Arabinoxylan (AX) is an abundant hemicellulose in wheat bran and an important functional component in bakery products. This review compares preprocessing and extraction methods, and evaluates their effect on AX properties and functionality as a bread ingredient. The extraction process results in AX isolates or concentrates with varying molecular characteristics, indicating that the process can be adjusted to produce AX with targeted functionality. AX functionality in bread seems to depend on AX properties but also on AX addition level and interactions with other components. This review suggests that the use of AX with tailored properties together with properly optimized baking process could help increasing the amount of added fiber in bread while maintaining or even improving bread quality

Soft-tissue thickness compensation for ultrasound transit time spectroscopy estimated bone volume fraction - an experimental replication study

Quantitative Ultrasound (QUS) offers a reliable means to predict osteoporotic fracture risk, although to date it has not been generally used within routine clinical management since it does not provide a direct estimate of bone mineral density (BMD), and hence, the associated WHO criteria for osteopenia and osteoporosis. Langton has proposed that ultrasound propagation through cancellous bone may be considered as an array of parallel sonic-rays, the transit-time of each determined by the corresponding proportion of bone and marrow propagated. This concept has led to the development of ultrasound transit time spectroscopy (UTTS) to estimate solid (bone) volume fraction (SVF). However, within the real-world clinical environment, a bone, such as the calcaneus, has overlying soft-tissues that would result in a significantly time-extended transit time spectrum (TTS), and hence, an underestimated SVF. The aims of this experimental replication study were firstly, to investigate the effect of overlying soft-tissues upon UTTS derived SVF (UTTS-SVF) estimation, and secondly, to develop and evaluate a method to compensate for this, thereby providing a more accurate estimation of SVF. Four 3D-cylindrical replica cancellous bone samples, with flat-parallel cortex discs on opposite faces, were studied; with varying thicknesses of water-replicating overlying soft-tissues. Through-transmission ultrasound signals were recorded, from which the apparent TTS was derived via deconvolution. Pulse-echo signals were utilised to measure the thickness of water overlying the replica cortices. The TTS was then corrected for the ultrasound transit-time associated with the overlying water. Ultrasound transit time spectroscopy derived solid volume fraction (UTTS-SVF) was then calculated, and compared with the SVF value measured with microcomputed tomography (μCT-SVF). The results demonstrated that varying water- thicknesses for each sample provided very similar formats of ultrasound transit-time spectra, but with significant extended time shifts. Compensation for overlying water thickness provided an accurate estimate of SVF for all samples; the overall of agreement between UTTS-SVF with μCT-SVF being 92.68%. It is therefore suggested that UTTS has the potential to provide a reliable in-vivo estimate of BMD and hence application of the established WHO T-score for routine clinical assessment of osteoporosis

Wave propagation in stereo-lithographical (STL) bone replicas at oblique incidence

Comparisons between predictions of a Biot-Allard model allowing for angle-dependent elasticity and angle-and-porosity dependent tortuosity and transmission data obtained at normal incidence on water-saturated replica bones are extended to oblique incidence. The model includes two parameters which are adjusted for best fit at normal incidence. Using the same parameter values, it is found that predictions of the variation of transmitted waveforms with angle through two types of bone replica are in reasonable agreement with data despite the fact that scattering is not included in the theory

Association of adrenal steroids with metabolomic profiles in patients with primary and endocrine hypertension

Introduction: Endocrine hypertension (EHT) due to pheochromocytoma/paraganglioma (PPGL), Cushing’s syndrome (CS), or primary aldosteronism (PA) is linked to a variety of metabolic alterations and comorbidities. Accordingly, patients with EHT and primary hypertension (PHT) are characterized by distinct metabolic profiles. However, it remains unclear whether the metabolomic differences relate solely to the disease-defining hormonal parameters. Therefore, our objective was to study the association of disease defining hormonal excess and concomitant adrenal steroids with metabolomic alterations in patients with EHT. Methods: Retrospective European multicenter study of 263 patients (mean age 49 years, 50% females; 58 PHT, 69 PPGL, 37 CS, 99 PA) in whom targeted metabolomic and adrenal steroid profiling was available. The association of 13 adrenal steroids with differences in 79 metabolites between PPGL, CS, PA and PHT was examined after correction for age, sex, BMI, and presence of diabetes mellitus. Results: After adjustment for BMI and diabetes mellitus significant association between adrenal steroids and metabolites – 18 in PPGL, 15 in CS, and 23 in PA – were revealed. In PPGL, the majority of metabolite associations were linked to catecholamine excess, whereas in PA, only one metabolite was associated with aldosterone. In contrast, cortisone (16 metabolites), cortisol (6 metabolites), and DHEA (8 metabolites) had the highest number of associated metabolites in PA. In CS, 18-hydroxycortisol significantly influenced 5 metabolites, cortisol affected 4, and cortisone, 11-deoxycortisol, and DHEA each were linked to 3 metabolites. Discussions: Our study indicates cortisol, cortisone, and catecholamine excess are significantly associated with metabolomic variances in EHT versus PHT patients. Notably, catecholamine excess is key to PPGL’s metabolomic changes, whereas in PA, other non-defining adrenal steroids mainly account for metabolomic differences. In CS, cortisol, alongside other non-defining adrenal hormones, contributes to these differences, suggesting that metabolic disorders and cardiovascular morbidity in these conditions could also be affected by various adrenal steroids.</p

Association of adrenal steroids with metabolomic profiles in patients with primary and endocrine hypertension

Introduction: Endocrine hypertension (EHT) due to pheochromocytoma/paraganglioma (PPGL), Cushing’s syndrome (CS), or primary aldosteronism (PA) is linked to a variety of metabolic alterations and comorbidities. Accordingly, patients with EHT and primary hypertension (PHT) are characterized by distinct metabolic profiles. However, it remains unclear whether the metabolomic differences relate solely to the disease-defining hormonal parameters. Therefore, our objective was to study the association of disease defining hormonal excess and concomitant adrenal steroids with metabolomic alterations in patients with EHT. Methods: Retrospective European multicenter study of 263 patients (mean age 49 years, 50% females; 58 PHT, 69 PPGL, 37 CS, 99 PA) in whom targeted metabolomic and adrenal steroid profiling was available. The association of 13 adrenal steroids with differences in 79 metabolites between PPGL, CS, PA and PHT was examined after correction for age, sex, BMI, and presence of diabetes mellitus. Results: After adjustment for BMI and diabetes mellitus significant association between adrenal steroids and metabolites – 18 in PPGL, 15 in CS, and 23 in PA – were revealed. In PPGL, the majority of metabolite associations were linked to catecholamine excess, whereas in PA, only one metabolite was associated with aldosterone. In contrast, cortisone (16 metabolites), cortisol (6 metabolites), and DHEA (8 metabolites) had the highest number of associated metabolites in PA. In CS, 18-hydroxycortisol significantly influenced 5 metabolites, cortisol affected 4, and cortisone, 11-deoxycortisol, and DHEA each were linked to 3 metabolites. Discussions: Our study indicates cortisol, cortisone, and catecholamine excess are significantly associated with metabolomic variances in EHT versus PHT patients. Notably, catecholamine excess is key to PPGL’s metabolomic changes, whereas in PA, other non-defining adrenal steroids mainly account for metabolomic differences. In CS, cortisol, alongside other non-defining adrenal hormones, contributes to these differences, suggesting that metabolic disorders and cardiovascular morbidity in these conditions could also be affected by various adrenal steroids.</p

Improving health worker performance through text messaging: A mixed-methods evaluation of a pilot intervention designed to increase coverage of intermittent preventive treatment of malaria in pregnancy in West Nile, Uganda

Poor health worker performance is a well-documented obstacle to quality service provision. Due to the increasingly widespread availability of mobile devices, mobile health (mHealth) has received growing attention as a service improvement tool. This pilot study explored feasibility, acceptability and outcomes of an mHealth intervention designed to increase coverage of intermittent preventive treatment of malaria in pregnancy (IPTp) in two districts of West Nile, Uganda. In both districts, selected health workers (N = 48) received classroom training on malaria in pregnancy. All health workers in one district (N = 49) subsequently received 24 text messages reinforcing the training content. The intervention was evaluated using a mixed-methods approach, including four focus group discussions with health workers and three in-depth interviews with district health officials, health worker knowledge assessments one month (N = 90) and six months (N = 89) after the classroom training, and calculation of IPTp coverage from participating health facilities’ (N = 16) antenatal care registers covering six months pre- and post-intervention. Complementing classroom training with text messaging was found to be a feasible, acceptable and inexpensive approach to improving health worker performance. The messages served as reminders to those who had attended the classroom training and helped spread information to those who had not. Health workers in the district where text messages were sent had significantly better knowledge of IPTp, achieving an increased composite knowledge score of 6.00 points (maximum score: 40) compared with those in the district where only classroom training was provided. Average facility coverage of three doses of IPTp was also significantly higher where text messages were sent (85.8%) compared with the district where only classroom training was provided (54.1%). This intervention shows promise for the improvement of health worker performance for delivery of IPTp, and could have significant broader application