Effects of mass loading on the viability of assessing the state of healing of a fixated fractured long bone

Introduction

This paper aims to evaluate the effects of mass loading on the healing assessment of an internally fixated femur by vibrational means. The presence of soft tissue surrounding a femur increases damping and mass of a system, and hence affects the vibrational response of a mechanical structure by obscuring the coherent modes. This may compromise vibration-based monitoring strategies in identifying modes associated with fracture healing.

Methods

This paper presents a series of experimental works to address this issue. Two osteotomised composite femurs were internally fixated using a plate-screw system and an intramedullary nail. Soft tissue is approximated by surrounding an artificial Sawbone femur with modelling clay. The femur is excited by an instrumented impact hammer and instrumented with two accelerometers to record bending and torsion modes between 0 and 600 Hz. A 30-min epoxy was applied to simulate the healing of the fractured femur in the osteotomised region. The resonant frequencies and its modes are monitored while union is being formed and a healing index is calculated at various times to quantify the degree of healing.

Results

The results demonstrate that the effect of modelling clay compressed the natural modes along the frequency axis. It is observed that frequency bandwidth in the vicinity of 150 Hz and 500 Hz is sensitive to the state of healing of the fixated femurs, which is due to the increase in stiffness of the osteotomised region. These findings were used to formulate the healing index which assists in identifying the initial, later and complete healing stages in conjunction with the index derivative.

Conclusion

In this study, a two-sensor measurement strategy to quantify fixated femur healing is investigated. It is shown that the mass loading effect did not affect this vibrational analysis method ability to assess the state of healing, and both coherent bending and twisting modes associated with healing were easily identified. The proposed healing index, its derivative, and the cross-spectra are a viable tool for quantitative healing assessment.

Mortality risk reduction differs according to bisphosphonate class: a 15-year observational study

In this prospective cohort of 6120 participants aged 50+, nitrogen-bisphosphonates but not non-nitrogen bisphosphonates were associated with a significant 34% mortality risk reduction compared to non-treated propensity score matched controls. These findings open new avenues for research into mechanistic pathways.

INTRODUCTION

Emerging evidence suggests that bisphosphonates (BP), first-line treatment of osteoporosis, are associated with reduced risks for all-cause mortality. This study aimed to determine the association between different BP types and mortality risk in participants with or without a fracture.

METHODS

A prospective cohort study of users of different BPs matched to non-users by propensity score (age, gender, co-morbidities, fragility fracture status) and time to starting the BP medication from the population-based Canadian Multicentre Osteoporosis Study from nine Canadian centres followed from 1995 to 2013. Mortality risk for bisphosphonate users vs matched non-users was assessed using pairwise multivariable Cox proportional hazards models.

RESULTS

There were 2048 women and 308 men on BP and 1970 women and 1794 men who did not receive medication for osteoporosis. The relationship between BP and mortality risk was explored in three separate 1:1 propensity score-matched cohorts of BP users and no treatment (etidronate, n = 599, alendronate, n = 498, and risedronate n = 213). Nitrogen BP (n-BP) (alendronate and risedronate) was associated with lower mortality risks [pairwise HR, 0.66 (95% CI, 0.48-0.91)] while the less potent non-n-BP, etidronate, was not [pairwise HR: 0.89 (95% CI, 0.66-1.20)]. A direct comparison between n-BP and etidronate (n = 340 pairs) also suggested a better survival for n-BP [paired HR, 0.47 (95%CI, (95% CI, 031-0.70)] for n-BP vs. etidronate].

CONCLUSION

Compared to no treatment, nitrogen but not non-nitrogen bisphosphonates appear to be associated with better survival.

Bacterial population dynamics after foliar fertilization of almond leaves

AIMS

To describe the effects of foliar fertilizer application on the bacterial populations of almond tree leaves.

METHODS AND RESULTS

We applied a commercially available foliar fertilizer or a water control onto the leaves of almond trees and collected leaves after 1, 7, 14 and 56 days and examined their bacterial populations by 16S rRNA gene sequence analysis. After 1 day, we observed significant differences in 3 of the 4 predominant bacterial phyla, and 5 of the 13 predominant bacterial families. After 7 days, we observed significant differences in all of the predominant phyla, and 8 of the 13 predominant families. After 14 days, the number of significant differences decreased, and after 56 days only 2 of the 13 predominant families differed significantly.

CONCLUSIONS

Foliar fertilization significantly altered the bacterial population structure of almond leaves as compared to the water control. While most of the observed perturbation was transient, significant differences remained after 56 days.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report describing the effects of foliar fertilization on the bacterial populations of almond leaves and provides new insights as to how this process alters the leaf bacterial population structure.

Solar Sources of Interplanetary Magnetic Clouds Leading to Helicity Prediction

This study identifies the solar origins of magnetic clouds that are observed at 1 AU and predicts the helical handedness of these clouds from the solar surface magnetic fields. We started with the magnetic clouds listed by the Magnetic Field Investigation (MFI) team supporting NASA's Wind spacecraft in what is known as the MFI table and worked backward in time to identify solar events that produced these clouds. Our methods utilize magnetograms from the Helioseismic and Magnetic Imager instrument on the Solar Dynamics Observatory spacecraft so that we could only analyze MFI entries after the beginning of 2011. This start date and the end date of the MFI table gave us 37 cases to study. Of these we were able to associate only eight surface events with clouds detected by Wind at 1 AU. We developed a simple algorithm for predicting the cloud helicity that gave the correct handedness in all eight cases. The algorithm is based on the conceptual model that an ejected flux tube has two magnetic origination points at the positions of the strongest radial magnetic field regions of opposite polarity near the places where the ejected arches end at the solar surface. We were unable to find events for the remaining 29 cases: lack of a halo or partial halo coronal mass ejection in an appropriate time window, lack of magnetic and/or filament activity in the proper part of the solar disk, or the event was too far from disk center. The occurrence of a flare was not a requirement for making the identification but in fact flares, often weak, did occur for seven of the eight cases.

Real-world patient- and caregiver-reported outcomes in advanced breast cancer

Background

Advanced breast cancer (abc) represents a substantial burden for patients and caregivers. In the present study, we aimed to estimate quality of life (qol), utility, productivity loss, pain, health care resource utilization, and costs for patients with abc, and qol, utility, and productivity loss for their caregivers.

Methods

This multicentre prospective non-interventional study was conducted in Canada. Eligible participants were postmenopausal women with estrogen receptor-positive, her2-negative unresectable abc and their caregivers. Validated questionnaires were used to measure qol, utility, productivity loss, and pain. Patients and caregivers were classified into 4 health states typically used in oncology economic modelling: first-line progression-free (1l-pf), first-line progressive disease (1l-pd), second- or subsequent-line progression-free (≥2l-pf), and second- or subsequent-line progressive disease (≥2l-pd).

Results

Most patients and caregivers accepted to participate, with total recruitment of 202 patients and 78 caregivers. Compared with patients in pf, patients in pd had lower mean qol scores (52.9 ± 29.9 for 1l-pd vs. 68.2 ± 23.2 for 1l-pf, and 54.0 ± 23.6 for ≥2l-pd vs. 66.0 ± 22.1 for ≥2l-pf), lower mean utility values (0.64 ± 0.22 for 1l-pd vs. 0.73 ± 0.20 for 1l-pf, and 0.65 ± 0.25 for ≥2l-pd vs. 0.74 ± 0.18 for ≥2l-pf), and greater productivity loss (39.4 ± 27.7 for 1l-pd vs. 27.5 ± 30.1 for 1l-pf, and 37.6 ± 29.2 for ≥2l-pd vs. 32.0 ± 29.0 for ≥2l-pf). Compared with caregivers of patients in pf, caregivers of patients in pd had lower qol scores and utility values, and greater productivity loss.

Conclusions

Study results indicate that, for patients and caregivers, pd health states are associated with a deterioration of qol and utility and a decrease in productivity in both 1l and ≥2l.

Therapeutic cancer vaccine: building the future from lessons of the past

Anti-cancer vaccines have raised many hopes from the start of immunotherapy but have not yet been clinically successful. The few positive results of anti-cancer vaccines have been observed in clinical situations of low tumor burden or preneoplastic lesions. Several new concepts and new results reposition this therapeutic approach in the field of immunotherapy. Indeed, cancers that respond to anti-PD-1/PD-L1 (20-30%) are those that are infiltrated by anti-tumor T cells with an inflammatory infiltrate. However, 70% of cancers do not appear to have an anti-tumor immune reaction in the tumor microenvironment. To induce this anti-tumor immunity, therapeutic combinations between vaccines and anti-PD-1/PD-L1 are being evaluated. In addition, the identification of neoepitopes against which the immune system is less tolerated is giving rise to a new enthusiasm by the first clinical results of the vaccine including these neoepitopes in humans. The ability of anti-cancer vaccines to induce a population of anti-tumor T cells called memory resident T cells that play an important role in immunosurveillance is also a new criterion to consider in the design of therapeutic vaccines.

How do caregivers understand and respond to unsettled infant behaviour in Vietnam? A qualitative study

BACKGROUND

Unsettled infant behaviours are a common source of concern for new parents and have been associated with perinatal common mental disorders amongst women in high-income settings. There is little evidence about how unsettled infant behaviours are understood and managed in low and lower-middle income countries. This study aimed to describe caregivers' understandings of, and responses to, unsettled infant behaviours in Vietnam and their family caregiving contexts.

METHODS

Women who were mothers of infants aged 0-6 months were purposively recruited from two sites in Thua Thien Hue Province, Vietnam (one urban and one rural). An additional group of women who were grandmothers were recruited by snowball sampling. Data were collected in semi-structured interviews about demographic information, infant feeding practices, descriptions of infant crying episodes, beliefs about why infants cry, settling strategies, infant sleeping arrangements and sources of advice on infant care. Translated interview transcripts were analysed thematically.

RESULTS

Twenty-four interviews were undertaken (21 with mothers and 3 with grandmothers). Five major themes emerged from the data after analysis: infant settling techniques, sources of information on unsettled infant behaviour, understandings of the causes of infant crying, the emotional responses of caregivers and the intergenerational household context. Infants were commonly cared for by people from multiple generations, particularly during the day. Infant settling was characterized by attending to infants immediately, breastfeeding and bed-sharing with parents during the night. Most mothers received advice on caregiving from family members. Infant crying was attributed to hunger and loneliness, as well as traditional beliefs that the infant was being upset by 'ghosts' or becoming 'hot'. Women described feeling anxious, frustrated and helpless in relation to unsettled behaviours amongst their infants.

CONCLUSIONS

Educational interventions on interpreting infant cues, infant sleep requirements and bed sharing may be appropriate in Vietnam if multiple generations are included and traditional beliefs about infant crying are addressed.