Biodegradable Magnesium Alloys for Personalised Temporary Implants.

The objective of this experimental work was to examine and characterise the route for obtaining demonstrative temporary biodegradable personalised implants from the Mg alloy Mg-10Zn-0.5Zr-0.8Ca (wt.%). This studied Mg alloy was obtained in its powder state using the mechanical alloying method, with shape and size characteristics suitable for ensuing 3D additive manufacturing using the SLM (selective laser melting) procedure. The SLM procedure was applied to various processing parameters. All obtained samples were characterised microstructurally (using XRD-X-ray diffraction, and SEM-scanning electron microscopy); mechanically, by applying a compression test; and, finally, from a corrosion resistance viewpoint. Using the optimal test processing parameters, a few demonstrative temporary implants of small dimensions were made via the SLM method. Our conclusion is that mechanical alloying combined with SLM processing has good potential to manage 3D additive manufacturing for personalised temporary biodegradable implants of magnesium alloys. The compression tests show results closer to those of human bones compared to other potential metallic alloys. The applied corrosion test shows result comparable with that of the commercial magnesium alloy ZK60.

Laser Powder Bed Fusion Applied to a New Biodegradable Mg-Zn-Zr-Ca Alloy.

The aim of the present paper is to apply the laser powder bed fusion process to a new biodegradable Mg-Zn-Zr-Ca alloy powder prepared via a mechanical alloying method from powder pure components. This additive manufacturing method is expected to allow for the obtaining of high biomechanical and biochemical performance. Various processing parameters for laser powder bed fusion are tested, with a special focus on laser energy density-E [J/mm3]-which is calculated for all experiment variants, and which represents an important processing parameter, dependent upon all the rest. The goal of all the trials is to find the most efficient schema for the production of small biodegradable parts for the medical domain, meaning the selection of optimal processing parameters. An important observation is that the most robust and homogeneous samples without cracks are obtained for lower values of the E, around 100 J/mm3. Thus, the most performant samples are analyzed by scanning electron microscopy, X-ray diffraction and by compression mechanical test.

Tailoring a Low Young Modulus for a Beta Titanium Alloy by Combining Severe Plastic Deformation with Solution Treatment.

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti-Nb-Zr-Fe-O alloy of ß-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of εtot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young's modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young's modulus of about 48-49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of ß-stabilizing alloying elements, especially the Zr/Nb ratio.

Do Investments in Mental Health Systems Result in Greater Use of Mental Health Services? National Trends in Mental Health Service Use (MHSU) in the Canadian Military and Comparable Canadian Civilians, 2002-2013.

BACKGROUND: Mental disorders constitute a significant public health problem worldwide. Ensuring that those who need mental health services access them in an appropriate and timely manner is thus an important public health priority. We used data from 4 cross-sectional, nationally representative population health surveys that employed nearly identical methods to compare MHSU trends in the Canadian military versus comparable civilians. METHOD: The surveys were all conducted by Statistics Canada, approximately a decade apart (Military-2002, Military-2013, Civilian-2002, and Civilian-2012). The sample size for the pooled data across the surveys was 35,984. Comparisons across the 4 surveys were adjusted for differences in need in the 2 populations at the 2 time points. RESULTS: Our findings suggested that first, in the Canadian military, there was a clear and consistent pattern of improvement (i.e., increase) in MHSU over the past decade across a variety of provider types. The magnitudes of the changes were large, representing an absolute increase of 7.15% in those seeking any professional care, corresponding to an 84% relative increase. Second, in comparable Canadian civilians, MHSU remained either unchanged or increased only slightly. Third, the increases in MHSU over time were consistently greater in the military than in the comparable civilian sample. CONCLUSIONS: Our findings point to advantages with respect to MHSU of the military mental health system over the civilian system in Canada; these advantages have widened substantially over time. These findings speak strongly to the potential impact of analogous changes in other health systems, both military and civilian.

Mental Illness-Related Stigma in Canadian Military and Civilian Populations: A Comparison Using Population Health Survey Data.

OBJECTIVE: This study sought to compare the prevalence and impacts of mental illness-related stigma among Canadian Armed Forces personnel and Canadian civilians. METHODS: Data were from two highly comparable, population-based, cross-sectional surveys of Canadian military personnel and Canadian civilians: the 2013 Canadian Forces Mental Health Survey (N=6,696) and the 2012 Canadian Community Health Survey-Mental Health (N=25,113), respectively. Perceived stigma was assessed among those who reported care seeking for a mental health problem in the past 12 months. Follow-up questions assessed the impact of stigma in various domains. Modified Poisson regression and linear regression were used to examine population differences (military versus civilian) in terms of care seeking, stigma, and stigma impact, with adjustments for sociodemographic characteristics and the need for care. RESULTS: Military personnel were significantly more likely than civilians to have perceived stigma (adjusted prevalence ratio [PR]=1.70, 95% confidence interval [CI]=1.11-2.60). Stigma had a greater impact on military personnel, particularly in terms of work or school life (b=1.01, CI=.57-1.47). However, military personnel were also significantly more likely than civilians to have sought care (PR=1.86, CI=1.53-2.25). CONCLUSIONS: Military personnel reported a disproportionate amount of mental illness-related stigma, compared with Canadian civilians, and a greater impact of stigma. Nevertheless, military personnel were more likely to seek care, pointing to a complex relationship between stigma and care seeking in the military.

Prevalence of Past-Year Mental Disorders in the Canadian Armed Forces, 2002-2013.

OBJECTIVE: More than 40,000 Canadian Armed Forces (CAF) personnel have deployed in support of the mission in Afghanistan since 2002. Over the same period, the CAF strengthened its mental health system. This article explores the effect of these events on the prevalence of past-year mental disorders over the period 2002-2013. METHOD: The data sources were 2 highly comparable population-based mental health surveys of CAF Regular Force personnel done in 2002 and 2013 (n = 5155 and 6996, respectively). Data were collected via in-person interviews with Statistics Canada personnel using the World Health Organization's Composite International Diagnostic Interview to assess past-year disorders. RESULTS: In 2013, 16.5% had 1 or more of the 6 past-year disorders assessed in the survey, with the most common conditions being major depressive episode (MDE), posttraumatic stress disorder (PTSD), and generalized anxiety disorder (GAD), which affected 8.0%, 5.3%, and 4.7%, respectively. The prevalence of PTSD, GAD, and panic disorder has increased significantly since 2002 (adjusted odds ratios from logistic regression models = 2.1, 3.0, and 1.9, respectively), while no change was seen for MDE. The comorbidity of mood and anxiety disorders increased significantly over time, being seen in 27.4% and 41.0% of those with mental disorders in 2002 and 2013, respectively. CONCLUSION: There has been an increase in the prevalence of PTSD and other anxiety disorders and of the extent of comorbidity of mood and anxiety disorders in CAF personnel over the period 2002-2013.

Prevalence Comparison of Past-year Mental Disorders and Suicidal Behaviours in the Canadian Armed Forces and the Canadian General Population.

OBJECTIVE: Military personnel in Canada and elsewhere have been found to have higher rates of certain mental disorders relative to their corresponding general populations. However, published Canadian data have only adjusted for age and sex differences between the populations. Additional differences in the sociodemographic composition, labour force characteristics, and childhood trauma exposure in the populations could be driving these prevalence differences. Our objective is to compare the prevalence of past-year mental disorders and suicidal behaviours in the Canadian Armed Forces Regular Force with the rates in a representative, matched sample of Canadians in the general population (CGP). METHODS: Data sources were the 2013 Canadian Forces Mental Health Survey and the 2012 Canadian Community Health Survey-Mental Health. CGP sample was restricted to match the age range, employment status, and history of chronic conditions of Regular Force personnel. An iterative proportional fitting method was used to approximate the marginal distribution of sociodemographic and childhood trauma variables in both samples. RESULTS: Relative to the matched CGP, Regular Force personnel had significantly higher rates of past-year major depressive episode, generalized anxiety disorder, and suicide ideation. However, lower rates of alcohol use disorder were seen in Regular Force personnel relative to the matched CGP sample. CONCLUSIONS: Factors other than differences in sociodemographic composition and history of childhood trauma account for the excess burden of mental disorders and suicidal behaviours in the Canadian Armed Forces. Explanations to explore in future research include occupational trauma, selection effects, and differences in the context of administration of the 2 surveys.

Occupational outcomes following mild traumatic brain injury in Canadian military personnel deployed in support of the mission in Afghanistan: a retrospective cohort study.

OBJECTIVE: Deployment-related mild traumatic brain injury (MTBI) occurs in a significant number of military personnel but its long-term impacts are unclear. This study explores the impact of deployment-related MTBI on continued fitness-for-duty, with the ultimate intent of identifying potential targets for intervention to attenuate its effects. PARTICIPANTS: Consisted of 16 193 Canadian Armed Forces (CAF) personnel who deployed in support of the mission in Afghanistan and completed an enhanced postdeployment screening (EPDS) questionnaire over the period January 2009-July 2012. PRIMARY OUTCOME: The primary outcome was development of permanent medical unfitness defined as a 'career-limiting medical condition' (CL-MC). The secondary outcome was the diagnostic categories recorded for each individual at the time a CL-MC was established. DESIGN: This study used a retrospective cohort design. Linked administrative and health data provided the primary outcome and the diagnoses responsible for it. Survival analysis was used to estimate the risk of a CL-MC and Cox regression provided adjusted HRs (aHRs) for the association between a CL-MC and MTBI, accounting for key covariates and confounders. Diagnostic categories associated with CL-MCs were identified. RESULTS: Over a median follow-up period of 3.42 years, 6.57% of the study population developed a CL-MC. MTBI was independently associated with CL-MCs (aHR=1.65, 95% CI 1.35 to 2.03). Mental disorders and musculoskeletal conditions were the primary diagnoses associated with CL-MCs (identified as the primary diagnosis in 55.4% and 25.9%, respectively), and a neurological condition was only documented in 5.8% of those with MTBI who developed a CL-MC CONCLUSIONS: Deployment-related MTBI was associated with adverse occupational outcome but mental disorders and musculoskeletal conditions primarily drove subsequent medical unfitness. These findings support a diagnostic and treatment approach focusing on these comorbidities as the most promising strategy to minimise the burden of disability in MTBI-exposed military personnel.

Arthritis has an impact on the daily lives of Canadians young and old: results from a population-based survey.

BACKGROUND: There is a perception that the impacts of arthritis are greatest among older adults. However, the effect of age on health-related outcomes in individuals with arthritis has not been explicitly studied. This study examined whether the physical and mental health impacts of arthritis are greater in older (75+ years) versus younger (20-44, 45-64 and 65-74 years) Canadian adults. METHODS: Data were from the arthritis component of the 2009 Survey on Living with Chronic Diseases in Canada. The responses were weighted to be representative of Canadians (≥20 years) with arthritis. Associations between age and the prevalence of severe/frequent joint pain, severe/frequent fatigue, sleep limitations, instrumental activities of daily living (IADLs) limitations, high levels of stress, suboptimal general and suboptimal mental health, were examined descriptively prior to conducting multivariate log-binomial regression analyses. RESULTS: A total of 4565 respondents completed the survey (78% response rate). Individuals with arthritis were mostly female (63%), of working age (57%) and overweight or obese (67%). Upon adjusting for covariates, younger (20-44 years) and/or middle aged (45-64 years) adults were more likely than those older (75+ years) to report severe/frequent joint pain, sleep limitations, high levels of stress and suboptimal mental health. After adjusting for covariates, age was not associated with IADL limitations, severe/frequent fatigue or suboptimal general health. CONCLUSIONS: Contrary to the belief that older adults with arthritis experience more severe physical and mental health outcomes, we found that older adults were less likely to report worse outcomes than younger adults. In light of these findings, public health messaging should stress that arthritis does not just affect the elderly and emphasize the importance of timely diagnosis and management at all ages in order to prevent or, minimize arthritis-related impairment.

CARTOONS KILL: casualties in animated recreational theater in an objective observational new study of kids' introduction to loss of life.

OBJECTIVES: To assess the risk of on-screen death of important characters in children's animated films versus dramatic films for adults. DESIGN: Kaplan-Meier survival analysis with Cox regression comparing time to first on-screen death. SETTING: Authors' television screens, with and without popcorn. PARTICIPANTS: Important characters in 45 top grossing children's animated films and a comparison group of 90 top grossing dramatic films for adults. MAIN OUTCOME MEASURES: Time to first on-screen death. RESULTS: Important characters in children's animated films were at an increased risk of death compared with characters in dramatic films for adults (hazard ratio 2.52, 95% confidence interval 1.30 to 4.90). Risk of on-screen murder of important characters was higher in children's animated films than in comparison films (2.78, 1.02 to 7.58). CONCLUSIONS: Rather than being the innocuous form of entertainment they are assumed to be, children's animated films are rife with on-screen death and murder.

Deployment-related mild traumatic brain injury, mental health problems, and post-concussive symptoms in Canadian Armed Forces personnel.

BACKGROUND: Up to 20% of US military personnel deployed to Iraq or Afghanistan experience mild traumatic brain injury (mTBI) while deployed; up to one-third will experience persistent post-concussive symptoms (PCS). The objective of this study was to examine the epidemiology of deployment-related mTBI and its relationship to PCS and mental health problems (MHPs) in Canadian Armed Forces (CAF) personnel. METHODS: Participants were 16153 personnel who underwent post-deployment screening (median =136 days after return) following deployment in support of the mission in Afghanistan from 2009 - 2012. The screening questionnaire assessed mTBI and other injuries while deployed, using the Brief Traumatic Brain Injury Screening Tool. Current MHPs and PCS were assessed using items from the Patient Health Questionnaire, the Patient Checklist for PTSD, and the Cognitive Failures Questionnaire. Log-binomial regression explored the association of mTBI, other injuries, and MHPs with PCS, using the presence of 3 or more of 7 PCS as the outcome. Results are expressed as adjusted prevalence ratios (PR). RESULTS: mTBI while deployed was reported in 843 respondents (5.2%). Less severe forms of mTBI (associated only with having been dazed or confused or having "seen stars") predominated. Blast was reported as a mechanism of injury in half of those with mTBI. Multiple PCS were present in 21% of those with less severe forms of mTBI and in 27% of those with more severe forms of mTBI (i.e., mTBI associated with loss of consciousness or post-traumatic amnesia). After adjustment for confounding, mTBI had no statistically significant association with PCS relative to non-TBI injury. In contrast, MHPs had a strong association with reporting 3 or more PCS (adjusted prevalence ratio (PR) =7.77). CONCLUSION: Deployment-related mTBI prevalence was lower than in many US reports; most of those who had had mTBI were free of multiple PCS. PCS was strongly associated with MHPs but not with mTBI. Careful assessment of MHPs is essential in personnel with a history of combat-related mTBI and PCS.

Prevalence and correlates of mental health problems in Canadian Forces personnel who deployed in support of the mission in Afghanistan: findings from postdeployment screenings, 2009-2012.

OBJECTIVE: An important minority of military personnel will experience mental health problems after overseas deployments. Our study sought to describe the prevalence and correlates of postdeployment mental health problems in Canadian Forces personnel. METHOD: Subjects were 16 193 personnel who completed postdeployment screening after return from deployment in support of the mission in Afghanistan. Screening involved a detailed questionnaire and a 40-minute, semi-structured interview with a mental health clinician. Mental health problems were assessed using the Patient Health Questionnaire and the Posttraumatic Stress Disorder Checklist-Civilian Version. Logistic regression was used to explore independent risk factors for 1 or more of 6 postdeployment mental health problems. RESULTS: Symptoms of 1 or more of 6 mental health problems were seen in 10.2% of people screened; the most prevalent symptoms were those of major depressive disorder (3.2%), minor depression (3.3%), and posttraumatic stress disorder (2.8%). The strongest risk factors for postdeployment mental health problems were past mental health care (adjusted odds ratio [AOR] 2.89) and heavy combat exposure (AOR 2.57 for third tertile, compared with first tertile). These risk groups might be targeted in prevention and control efforts. In contrast to findings from elsewhere, Reservist status, deployment duration, and number of previous deployments had no relation with mental health problems. CONCLUSIONS: An important minority of personnel will disclose symptoms of mental health problems during postdeployment screening. Differences in risk factors seen in different nations highlight the need for caution in applying the results of research in one population to another.

Sleep laboratory test referrals in Canada: sleep apnea rapid response survey.

BACKGROUND: An estimated 5.4 million Canadian adults have been diagnosed with sleep apnea or are at high risk of experiencing obstructive sleep apnea (OSA). There are no recent Canadian data regarding access to and predictors of referral for diagnostic testing in these populations. METHODS: The Sleep Apnea Rapid Response survey sampled 8647 Canadian adults and captured information about risk, testing, diagnosis and treatment of sleep apnea. Predictors of sleep laboratory test referrals were assessed using log-linked binomial regression modelling. Information regarding sleep testing facilities was updated at the provincial and regional levels. RESULTS: Approximately 76.8% (95% CI 70.1% to 83.6%) of adult Canadians with sleep apnea and 5.1% (95% CI 3.4% to 6.7%) of those at high risk for OSA reported being referred to a sleep laboratory. Significant predictors of sleep laboratory referral in the general population were male sex, middle age, overweight or obese, a chronic condition, having a regular medical doctor and reporting symptoms of sleep apnea. Region of residence was also a predictor of reported sleep laboratory referral, with individuals from Ontario being more likely to report being referred to a sleep laboratory versus individuals from other regions. CONCLUSION: Individuals reporting risk factors and symptoms associated with OSA were more likely to report a sleep laboratory testing referral compared with those without risk factors or symptoms. However, Canada's diagnostic sleep laboratory testing capacity varies across regions and is believed to be inadequate given the number of individuals at high risk for OSA who did not report testing referral.

Exercise/physical activity and weight management efforts in Canadians with self-reported arthritis.

OBJECTIVE: To describe the exercise/physical activity and weight management efforts of Canadians with self-reported arthritis, to examine factors associated with their engagement in these strategies to help manage their arthritis, and to explore reasons for lack of engagement. METHODS: Data were from the arthritis component of the 2009 Survey on Living with Chronic Diseases in Canada. The responses (78% response rate; n = 4,565) were weighted to be representative of Canadians (ages ≥20 years) with arthritis. Logistic regression analyses were used to examine factors associated with engaging in exercise/physical activity and weight control/loss (among overweight/obese respondents) for arthritis management purposes. RESULTS: Individuals with arthritis were mostly women (63%), ages ≥45 years (89%), overweight/obese (67%), married (68%), and white (87%), with postsecondary education (69%). Sixty-three percent were exercising and of those who were overweight or obese, 68% were trying to control/lose weight; only 46% were engaged in both. Having received a clinical recommendation was the factor most strongly associated with engaging in exercise/physical activity and/or controlling/losing weight. The most common reason for not exercising was a coexisting health condition/problem (22%), while the most common reason for not controlling/losing weight among those who were overweight/obese was that it was felt not to be necessary (51%). CONCLUSION: The provision of clinical recommendations from a health professional, providing advice on safe and suitable exercises/physical activities, as well as addressing misperceptions of the need to lose weight among the overweight/obese, may facilitate engagement in these health behaviors and ultimately reduce the consequences of arthritis.

Blind deconvolution for ultrasound sequences using a noninverse greedy algorithm.

The blind deconvolution of ultrasound sequences in medical ultrasound technique is still a major problem despite the efforts made. This paper presents a blind noninverse deconvolution algorithm to eliminate the blurring effect, using the envelope of the acquired radio-frequency sequences and a priori Laplacian distribution for deconvolved signal. The algorithm is executed in two steps. Firstly, the point spread function is automatically estimated from the measured data. Secondly, the data are reconstructed in a nonblind way using proposed algorithm. The algorithm is a nonlinear blind deconvolution which works as a greedy algorithm. The results on simulated signals and real images are compared with different state of the art methods deconvolution. Our method shows good results for scatters detection, speckle noise suppression, and execution time.