Mechanical and microarchitectural analyses of cancellous bone through experiment and computer simulation

The relationship between microarchitecture to the failure mechanism and mechanical properties can be assessed through experimental and computational methods. In this study, both methods were utilised using bovine cadavers. Twenty four samples of cancellous bone were extracted from fresh bovine and the samples were cleaned from excessive marrow. Uniaxial compression testing was performed with displacement control. After mechanical testing, each specimen was ashed in a furnace. Four of the samples were exemplarily scanned using micro-computed tomography (μCT) and three dimensional models of the cancellous bones were reconstructed for finite element simulation. The mechanical properties and the failure modes obtained from numerical simulations were then compared to the experiments. Correlations between microarchitectural parameters to the mechanical properties and failure modes were then made. The Young’s modulus correlates well with the bone volume fraction with R ² = 0.615 and P value 0.013. Three different types of failure modes of cancellous bone were observed: oblique fracture (21.7%), perpendicular global fracture (47.8%), and scattered localised fracture (30.4%). However, no correlations were found between the failure modes to the morphological parameters. The percentage of error between computer predictions and the actual experimental test was from 6 to 12%. These mechanical properties and information on failure modes can be used for the development of synthetic cancellous bone.     

An innovative prostheses design for rehabilitation of severely mutilated dentition: a case report

Partial edentulism has multiple implications in relation to function, esthetics and future rehabilitative treatment. This case report illustrates the management of a patient with extreme consequences of partial edentulism. The main clinical findings were unopposed remaining teeth, overeruption of the remaining teeth, loss of vertical dimension of occlusion, and significant disfigurement of the occlusal plane. Following the diagnostic procedure, a well-coordinated prosthodontic treatment involving liaison with other dental disciplines was indicated. The management involved an innovative combination of fixed and removable prostheses in conjunction with crown lengthening surgery and strategic implant placement. Series of provisional prostheses were applied to facilitate the transition to the final treatment.     

New bioactive glass-ceramic: synthesis and application in PMMA bone cement composites

In present study, a new composition of glass-ceramic was synthesized based on the Na2O-CaO-SiO2-P2O5 glass system. Heat treatment of glass powder was carried out in 2 stages: 600 °C as the nucleation temperature and different temperature on crystallization at 850, 950 and 1000 °C. The glass-ceramic heat-treated at 950 °C was selected as bioactive filler in commercial PMMA bone cement; (PALACOS? LV) due to its ability to form 2 high crystallization phases in comparison with 850 and 1000 °C. The results of this newly glass-ceramic filled PMMA bone cement at 0-16 wt% of filler loading were compared with those of hydroxyapatite (HA). The effect of different filler loading on the setting properties was evaluated. The peak temperature during the polymerization of bone cement decreased when the liquid to powder (L/P) ratio was reduced. The setting time, however, did not show any trend when filler loading was increased. In contrast, dough time was observed to decrease with increased filler loading. Apatite morphology was observed on the surface of the glass-ceramic and selected cement after bioactivity test.     

Descriptive epidemiology of osteoarthritis in British Columbia, Canada

OBJECTIVE: Osteoarthritis (OA) is a highly prevalent and often disabling disease. Data on the incidence of OA in the general population are limited. Our objectives were (1) to estimate OA prevalence and incidence rates by age and sex in a geographically defined population of 4 million people [British Columbia (BC), Canada] using an administrative database; and (2) to determine the effects of different administrative definitions of OA and observation (run-in) time on such estimates. METHODS: We used data on all visits to health professionals and hospital admissions covered by the Medical Services Plan (MSP) of BC for the fiscal years 1991-92 through 2000-01. OA was defined based on International Classification of Diseases, 9th Revision, diagnostic codes required for administrative purposes. RESULTS: The overall prevalence of OA in 2001 was 10.8%: 8.9% in men and 12.6% in women. Prevalence was higher in women in all age groups. By age 70-74 years, about one-third of men and 40% of women had OA. Incidence rates in 2000-01 were 11.7 per 1000 person-years in the total population, 10.0 in men and 13.4 in women. Rates increased linearly with age between 50 and 80 years. Both prevalence and incidence depended strongly on the definition of OA and the run-in period. CONCLUSION: Prevalence of physician-diagnosed OA in BC was slightly lower than self-reported prevalence of arthritis in population surveys. Routinely collected administrative data could be a valuable source of information for OA surveillance, but more research is needed on the validity of OA diagnosis in administrative databases.     

Utilization of mesoporous phosphotungstic acid in nanocellulose membranes for direct methanol fuel cells

Nanocellulose (NC) composite membranes containing novel ternary materials including NC, imidazole (Im), and mesoporous phosphotungstic acid (m-PTA) were successfully fabricated by a phase inversion method. The single-particle size of NC was 88.79 nm with a spherical form. A m-PTA filler with a mesopore size of 4.89 nm was also successfully synthesized by a self-assembly method. Moreover, the fabricated membrane NC/Im/m-PTA-5 exhibited the best performances towards its proton conductivity and methanol permeability at 31.88 mS cm⁻¹ and 1.74 × 10⁻⁶ cm² s⁻¹, respectively. The membrane selectivity was 1.83 × 10⁴ S cm⁻³.

A NC/Im/m-PTA membrane was fabricated for direct methanol fuel cell applications.     

Evaluation of Vector Competence of Ixodes Ticks for Kemerovo Virus

Tick-borne viruses are responsible for various symptoms in humans and animals, ranging from simple fever to neurological disorders or haemorrhagic fevers. The Kemerovo virus (KEMV) is a tick-borne orbivirus, and it has been suspected to be responsible for human encephalitis cases in Russia and central Europe. It has been isolated from Ixodes persulcatus and Ixodes ricinus ticks. In a previous study, we assessed the vector competence of I. ricinus larvae from Slovakia for KEMV, using an artificial feeding system. In the current study, we used the same system to infect different tick population/species, including I. ricinus larvae from France and nymphs from Slovakia, and I. persulcatus larvae from Russia. We successfully confirmed the first two criteria of vector competence, namely, virus acquisition and trans-stadial transmission, for both tick species that we tested. The estimated infection rates of engorged and moulted ticks suggest specificities between viral strains and tick species/developmental stages.     

Functionalised electrospun membranes (TETA-PVC) for the removal of lead(ii) from water

Driven by the need for delivering sustainable water purification solutions for the removal of heavy metals from water, electrospun PVC membranes were functionalised with triethylenetetramine (TETA) and were used to remove lead(ii) ions selectively from water. The membranes were characterised and their adsorption behavior towards the removal of lead from water was investigated. The incorporation of TETA on the membrane''s surface significantly improved the removal efficiency of lead(ii) up to 99.8% in 30 minutes and under ambient conditions, with the lowest concentration of 50 ppm. The adsorption mechanism was investigated and kinetic data showed a better correlation with the pseudo-second-order model. Similarly, the equilibrium data best fitted with the Langmuir adsorption isotherm model with a relatively high maximum adsorption capacity of 1250 mg g⁻¹ for lead(ii) ions, larger than recently reported adsorption capacities for similar membranes. The functionalised membrane also showed high selectivity to lead(ii) in a mixed solution containing lead(ii), mercury(ii), cadmium(ii), arsenic(iii), copper(ii), and zinc(ii). The functionalised membrane was regenerated, where desorption of lead(ii) was achieved, under mildly acidic conditions. The removal efficiency of the regenerated membrane after six cycles of adsorption/desorption was maintained at a high level of 98%. The proposed design offers a simple yet effective, sustainable, and environmentally friendly solution for water treatment.

Driven by the need for delivering sustainable water purification solutions for the removal of heavy metals from water, TETA functionalised electrospun PVC membranes were fabricated and used to remove lead(ii) ions selectively from water.     

A Review of Food Texture Modification among Individuals with Cerebral Palsy: The Challenges among Cerebral Palsy Families

Individuals with cerebral palsy (CP) frequently present with multiple feeding problems, which may require food texture modification to ensure safe feeding. This review aims to explore the challenges individuals with CP and their caregiver’s face and recommend modified food textures to ensure safety and improve the quality of life and nutritional status. A systematic search was carried out through four databases (i.e., EBSCO (Medline), PubMed, Science Direct, and Web of Science) between January 2011 and May 2022. Out of 86 articles retrieved, seven were selected based on keywords and seven other studies through manual search-five cross-sectional studies, two qualitative studies, one correlational study, one mixed method study, one case-control study, two sections of books, and two educational materials. The findings suggest that preparation and intake of food with modified texture play a necessary role in the safety of swallowing in addition to physical, social, and environmental aspects. Safety was found to be the crucial part of the food texture modification provision besides considering the stress of the caregivers and the nutritional status of individuals with CP. Currently, there are no standard guidelines available pertaining to food texture modification. This led to uncertainties in the dietary provision among caregivers, which may lead to undernourishment. Hence, standard guidelines relating to food texture modification that focuses on food preparation and menus with calorie and nutrient information are timely to be developed.     

Human ‘knockouts’ of CSF3 display severe congenital neutropenia

Colony-stimulating factor 3 (CSF3) is a key factor in neutrophil production and function, and recombinant forms have been used clinically for decades to treat congenital and acquired neutropenia. Although biallelic inactivation of its receptor CSF3R is a well-established cause of severe congenital neutropenia (SCN), no corresponding Mendelian disease has been ascribed to date to CSF3. Here, we describe three patients from two families each segregating a different biallelic inactivating variant in CSF3 with SCN. Complete deficiency of CSF3 as a result of nonsense-mediated decay (NMD) could be demonstrated on RT-PCR using skin fibroblasts-derived RNA. The phenotype observed in this cohort mirrors that documented in mouse and zebrafish models of CSF3 deficiency. Our results suggest that CSF3 deficiency in humans causes a novel autosomal recessive form of SCN.