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Background: The Nigerian Breast Cancer Study (NBCS) model is a new risk assessment tool developed for predicting risk of invasive breast cancer in Nigeria. Its applicability outside of Nigeria remains uncertain as it has not been validated in other sub-Saharan Africa populations. Methods: We conducted a case–control study among women with breast cancer and controls ascertained in Cameroon and Uganda from 2011 to 2016. Structured questionnaire interviews were performed to collect risk factor characteristics. The NBCS model, the Gail model, the Gail model for Black population, and the Black Women's Health Study model were applied to the Cameroon and Uganda samples separately. Nigerian as well as local incidence rates were incorporated into the models. Receiver-Operating Characteristic analyses were performed to indicate discriminating capacity. Results: The study included 550 cases (mean age 46.8 ± 11.9) and 509 controls (mean age 46.3 ± 11.7). Compared with the other three models, the NBCS model performed best in both countries. The discriminating accuracy of the NBCS model in Cameroon (age-adjusted C-index = 0.602; 95% CI, 0.542–0.661) was better than in Uganda (age-adjusted C-index = 0.531; 95% CI, 0.459–0.603). Conclusions: These findings demonstrate the potential clinical utility of the NBCS model for risk assessment in Cameroon. All currently available models performed poorly in Uganda, which suggests that the NBCS model may need further calibration before use in other regions of Africa. Impact: Differences in risk profiles across the African diaspora underscores the need for larger studies and may require development of region-specific risk assessment tools for breast cancer.

Residual stresses on aluminum parts can be modified during heat treatments. During solution heat treatment, quenching, and aging, metallurgical transformations combined with thermal gradients lead to a modification of parts properties. Quench and aging treatments sensitivity of AA 7175 aluminum alloy components is addressed in this work. Samples have been subjected to various quenching and aging treatments to verify the actual effect of the treatment parameters on their residual stresses. After a solution heat treatment, quenching has been performed in agitated and non-agitated water at room temperature, as well as at 67°C. The effects of the aging treatment (T74) and stress relief treatment have also been studied. Residual stresses determined by the contour method are reported and it is found that for the specimens used in this work, quenching into agitated water had no significant effect while warm water quench, T74 aging, and stress relief treatments substantially reduce the residual stresses.

Wen-Yang Li,1 Jean-Francois Masse,2 Simon Gakwaya,3 Zhenjin Zhao,4 Wei Wang,1,* Frédéric Sériès3,* 1Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People’s Republic of China; 2Faculté de Médecine Dentaire, Université Laval, Québec, QC, Canada; 3Unité de Recherche en Pneumologie, Centre de Recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, QC, Canada; 4Institute of Orthodontics, The Stomatological Hospital of China Medical University, Shenyang, People’s Republic of China*These authors contributed equally to this workCorrespondence: Wei Wang, Institute of Respiratory Disease, The First Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang, 110001, People’s Republic of China, Tel: +86 83282532, Email wwbycmu@126.com Frédéric Sériès, Centre de recherche, IUCPQ, 2725 chemin Sainte-Foy, Québec, QC, G1V 4G5, Canada, Email Frederic.Series@fmed.ulaval.caBackground: In-lab mandibular protrusive titration using a remotely controlled mandibular positioner (RCMP) could predict the success rate of mandibular advancement device (MAD) and reliably determine the Optimal Protrusive Position (OPP) for obstructive sleep apnea (OSA) patients. The aim of this study was to compare MAD success rate using in-lab RCMP manual titration performed in Caucasian and Chinese OSA patients.Methods: Manual RCMP titration was performed during an in-lab sleep study using the same procedure that had been previously reported in untreated Caucasian and Chinese OSA patients. Success rate was determined according to classical success criteria or to those previously used for RCMP titration.Results: A total of 160 subjects were included in this study, and conclusive data were obtained from 141 (71 Chinese and 70 Caucasian OSA patients). Chinese patients were significantly younger, with lower BMI and more severe OSA disease than the Canadian counterparts. Among patients with predicted success, the OPP expressed in % of full protrusion position did not differ between the two ethnic groups. Chinese ethnicity, younger age and lower baseline AHI were significant determinants of RCMP success. In a multivariate analysis, only ethnicity and AHI were found to significantly account for success, the odds ratio for success in Chinese compared to Caucasians corrected for AHI being 3.7 and 4.6 depending on criteria used to define success.Conclusion: Although the OSA disease was more severe in Chinese patients, the predicted success rate of MAD according to RCMP titration was higher in Chinese than in Caucasians. This study was registered on ClinicalTrials.gov (NCT03231254).Keywords: obstructive sleep apnea, mandibular advancement device, remotely controlled mandibular positioner, optimal protrusive position

In composite aircraft structures, woven carbon-fiber-reinforced composites are used as elements of the boxes to mitigate damage during crash events and provide a measure of protection for the passengers against abrupt decelerations. Due to their multi-scale damage effects and complex coupling between failure mechanisms, despite years of extensive works of researchers around the world, a complete and validated methodology for predicting crushing behavior of woven composite structures has not yet been achieved. In the present paper, experimental and numerical investigations were conducted. The principal contribution is to model and adapt failure mechanisms; fragmentation and kink-bandings, for plain weave fabric CFRP composites, within an advanced numerical model to predict the quasi-static crush behavior of hat-shape cross-section coupons. A meso-scale model, which accounts for intralaminar damage, implemented as a user subroutine VUMAT in Abaqus/Explicit was developed and used. Eight layers of stacked solid elements model were used with saw teeth type and 45° chamfer-type triggering mechanisms to ensure a continuous stable crushing mode of failure. A comparison with experimental and existing numerical model Abq_Ply_Fabric results confirms the computational tool’s accuracy.

Despite years of governmental and academic institutions’ researches, no experimental standards are established for evaluating crush Specific Energy Absorption SEA for plain weave fabric woven carbon-fiber-reinforced composites used in modern aircraft structures as elements of the boxes to mitigate damage during crush events. At the laboratory scale, this paper proposes a comparative study of energy absorption capability of flat plate coupons made by CFRP plain weave fabric composites. A new fixture design and setup were created with hydraulic pressure and drop tower machines to carry out tests of flat plate composite specimens under quasi-static and low velocity on-axis crash loading. For investigating parameters sensibility of triggers and layups, numerical and experimental results of four trigger types and three stacking sequences were compared. A confrontation between experimental and pre-developed UL-Crush numerical material model results confirms that coupons with 0˚ oriented central plies and saw teeth or corrugated triggers dissipates higher energy during crush, compared to coupons with 90˚ or 45˚ oriented central plies and chamfer 45˚ or steeple triggers. An efficient and simplified experimental methodology was developed to measure and investigate different parameters influencing SEA of composites under crush load. Comparison between experimental and UL-Crush material model confirms the performance of such simulation tool.

In crash event, aerospace structures are designed to collapse progressively, dissipating high kinetic energy and protecting the passengers against abrupt decelerations. To achieve this goal, a bett...

Background: Sub-Saharan Africa (SSA) has a high proportion of premenopausal hormone receptor negative breast cancer. Previous studies reported a strikingly high prevalence of germline mutations in BRCA1 and BRCA2 among Nigerian patients with breast cancer. It is unknown if this exists in other SSA countries. Methods: Breast cancer cases, unselected for age at diagnosis and family history, were recruited from tertiary hospitals in Kampala, Uganda and Yaoundé, Cameroon. Controls were women without breast cancer recruited from the same hospitals and age-matched to cases. A multigene sequencing panel was used to test for germline mutations. Results: There were 196 cases and 185 controls with a mean age of 46.2 and 46.6 years for cases and controls, respectively. Among cases, 15.8% carried a pathogenic or likely pathogenic mutation in a breast cancer susceptibility gene: 5.6% in BRCA1, 5.6% in BRCA2, 1.5% in ATM, 1% in PALB2, 0.5% in BARD1, 0.5% in CDH1, and 0.5% in TP53. Among controls, 1.6% carried a mutation in one of these genes. Cases were 11-fold more likely to carry a mutation compared with controls (OR = 11.34; 95% confidence interval, 3.44–59.06; P < 0.001). The mean age of cases with BRCA1 mutations was 38.3 years compared with 46.7 years among other cases without such mutations (P = 0.03). Conclusions: Our findings replicate the earlier report of a high proportion of mutations in BRCA1/2 among patients with symptomatic breast cancer in SSA. Impact: Given the high burden of inherited breast cancer in SSA countries, genetic risk assessment could be integrated into national cancer control plans.

Study Objectives Obstructive sleep apnea (OSA), sleep fragmentation, and short sleep duration (SD) have been associated with chronic kidney disease (CKD). However, these potential mechanisms for CKD have not been compared in the same cohort. This study investigated the independent and combined impact of OSA and insomnia with short sleep duration on the risk of CKD progression in a sleep clinic population. Methods In a cross-sectional study design, adults with suspected OSA completed an overnight sleep study and a questionnaire that included the Insomnia Severity Index (ISI) and Pittsburgh Sleep Quality Index (PSQI). They also provided blood and urine samples for measurement of the glomerular filtration rate and urine albumin:creatinine ratio, from which the risk of CKD progression was determined. Results Participants (n = 732, 41% female, 55 ± 13 years) were categorized into four groups: no/mild OSA without insomnia (NM-OSA, n = 203), insomnia with SD without OSA (Insomnia-SD, n = 104), moderate-to-severe OSA without insomnia (MS-OSA, n = 242), and comorbid insomnia and OSA with SD (COMISA-SD, n = 183). After stratification, 12.8% of NM-OSA, 15.4% of Insomnia-SD, 28.9% of MS-OSA, and 31.7% of the COMISA-SD participants had an increased risk of CKD progression. Compared to NM-OSA, the odds ratio (OR) for an increased risk of CKD progression was not increased in Insomnia-SD (OR 0.95, confidence interval [CI]: 0.45–1.99) and was increased to the same degree in MS-OSA (OR 2.79, CI: 1.60–4.85) and COMISA-SD (OR 3.04, CI: 1.69–5.47). However, the ORs were similar between the MS-OSA and COMISA-SD groups across all statistical models (p ≥ .883). Conclusions In a sleep clinic population, insomnia with short sleep duration does not increase the risk of CKD progression; nor does it further increase the risk of CKD progression associated with moderate-to-severe OSA.

Study Objectives Chronic kidney disease (CKD) is a global health concern and a major risk factor for cardiovascular morbidity and mortality. Obstructive sleep apnea (OSA) may exacerbate this risk by contributing to the development of CKD. This study investigated the prevalence and patient awareness of the risk of CKD progression in individuals with OSA. Methods Adults referred to five Canadian academic sleep centers for suspected OSA completed a questionnaire, a home sleep apnea test or in-lab polysomnography and provided blood and urine samples for measurement of estimated glomerular filtration rate (eGFR) and the albumin:creatinine ratio (ACR), respectively. The risk of CKD progression was estimated from a heat map incorporating both eGFR and ACR. Results 1295 adults (42% female, 54 ± 13 years) were categorized based on the oxygen desaturation index (4% desaturation): 30 (severe OSA, n = 421). After stratification, 13.6% of the no/mild OSA group, 28.9% of the moderate OSA group, and 30.9% of the severe OSA group had a moderate-to-very high risk of CKD progression (p < .001), which was defined as an eGFR Conclusion Patients with moderate and severe OSA have an increased risk of CKD progression independent of other CKD risk factors; most patients are unaware of this increased risk.