Geographic accessibility to physiotherapy care in Aotearoa New Zealand.

Disparities in care access for health conditions where physiotherapy can play a major role are abetting health inequities. Spatial analyses can contribute to illuminating inequities in health yet the geographic accessibility to physiotherapy care across New Zealand has not been examined. This population-based study evaluated the accessibility of the New Zealand physiotherapy workforce relative to the population at a local scale. The locations of 5,582 physiotherapists were geocoded and integrated with 2018 Census data to generate 'accessibility scores' for each Statistical Area 2 using the newer 3-step floating catchment area method. For examining the spatial distribution and mapping, accessibility scores were categorized into seven levels, centered around 0.5 SD above and below the mean. New Zealand has an above-average physiotherapy-to-population ratio compared with other OECD countries; however, this workforce is maldistributed. This study identified areas (and locations) where geographic accessibility to physiotherapy care is relatively low.

A Novel Sirolimus-Coated Balloon for the Treatment of Femoropopliteal Lesions: The SELUTION SFA Japan Trial.

BACKGROUND: Sirolimus-coated balloons (SCB) for the treatment of femoropopliteal (FP) lesions have not been systematically studied, but initial outcomes from early studies are promising. OBJECTIVES: The authors sought to evaluate the safety and efficacy of the SELUTION SLR SCB, composed of proprietary microreservoir technology combining sirolimus and biodegradable polymer, when used to treat mild-to-moderate FP disease in a Japanese population. METHODS: This multicenter, prospective, single-arm study (SELUTION SFA JAPAN) enrolled 134 patients with FP disease. It was independently adjudicated by an imaging core laboratory and clinical events committee. The primary endpoint was 12-month primary patency, defined as peak systolic velocity ratio ≥2.5 by duplex ultrasound and compared against a prespecified performance goal of 60% based on established angioplasty data. RESULTS: The mean age was 73.8 ± 6.9 years, and 60.3% of patients had diabetes mellitus. The mean lesion length was 127.4 ± 59.7 mm, 17.2% were chronic total occlusions, and 47.8% involved the popliteal artery. Data on 12-month restenosis were available in 127 patients (94.8%). The 12-month primary patency rate was 87.9%, and the freedom from clinically driven target lesion revascularization (CD-TLR) was 97.0% per Kaplan-Meier estimate. The major adverse event rate was 6.7%, driven by 4 CD-TLRs and 5 deaths, none of which were related to the device or procedure. Ankle-brachial index data improved significantly from 0.73 ± 0.16 at baseline to 0.96 ± 0.14 at 30 days postprocedure and was sustained through 12 months (0.94 ± 0.13). CONCLUSIONS: The SELUTION SFA JAPAN trial demonstrated that a novel SELUTION SCB is a safe and effective treatment option for FP disease in symptomatic patients.

The promise of nanofluids: A bibliometric journey through advanced heat transfer fluids in heat exchanger tubes.

Thermal management is a critical challenge in advanced systems such as electric vehicles (EVs), electronic components, and photoelectric modules. Thermal alleviation is carried out through the cooling systems in which the coolant and the heat exchangers are the key components. The study examines recent literature on nanofluids and heat exchanger tubes along with state-of-the-art concepts being tested for heat transfer intensification. The performance of nanofluids in several common heat transfer tubes' geometries/configurations and the effectiveness of novel heat transfer augmentation mechanisms are presented. Promising results have been reported, showing improved heat transfer parameters with the use of nanofluids and intensification mechanisms like turbulators, fins, grooves, and variations in temperature and flow velocity. These mechanisms enhance dispersion stability, achieve a more uniform temperature distribution, and reduce the boundary layer thickness, resulting in lower tube wall temperatures. Moreover, introducing flow pulsations and magnetic effects further enhances particle mobility and heat exchange. However, there are limitations, such as increased frictional losses and pressure drop due to magnetic effects. The combination of nanofluids, novel heat exchanger tube geometries, and turbulators holds great promise for highly efficient cooling systems in the future. The study also presents a bibliometric analysis that offers valuable insights into the impact and visibility of research in the integration of nanofluids into heat transfer systems. These insights aid in identifying emerging trends and advancing the field towards more efficient and compact systems, paving the way for future advancements.

Effect of antecedent statin usage on conduction disturbances and arrhythmias after transcatheter aortic valve replacement.

BACKGROUND: Post-transcatheter aortic valve replacement (TAVR) conduction disturbances and atrial fibrillation (AF) are associated with markedly worse short- and long-term prognosis. Statins have multiple pleotropic effects that may be beneficial in mitigating the risk of these procedural complications as has been found for various other cardiac procedures and surgeries. METHODS: Data were retrospectively collected on consecutive patients in the Yale New Haven Health TAVR Registry who did not have a prior pacemaker, had at least 1 pre- and post-TAVR electrocardiogram, and did not have a change to their statin regimen during the index hospitalization. The primary endpoint was the composite of new pacemaker placement, new AF, and other new conduction disturbances evaluated at 7 days post-TAVR. RESULTS: Between, July 2012 and August 2019, 612 patients met inclusion criteria. Of these, 162 patients were not on antecedent statins, and 450 were (28 low-intensity, 225 moderate-intensity, and 197 high-intensity). After 1:1 propensity matching, 99 patients on moderate-/high-intensity statins were matched to 99 patients not on antecedent statins. At 7 days, there was no significant difference in the occurrence of the primary endpoint (57 % statin users vs 46 % non-statin users; p = 0.16). There was a trend toward increased conduction disturbances 7 days after TAVR in statin users (56 % vs 42 %; p = 0.07), but rates of AF (5 % vs 8 %; p = 0.39) and pacemaker placement (9 % vs 15 %; p = 0.20) were numerically lower in statin users. There was no significant difference in persistent conduction disturbances (21 % vs 18 %; p = 0.59). CONCLUSIONS: Statins do not appear to reduce the risk of post-TAVR AF or conduction abnormalities in this small retrospective study.

Sex Differences in pLVAD-Assisted High-Risk Percutaneous Coronary Intervention: Insights From the PROTECT III Study.

BACKGROUND: Prior studies have found that female patients have worse outcomes following high-risk percutaneous coronary intervention (HRPCI). OBJECTIVES: The authors sought to evaluate sex-based differences in patient and procedural characteristics, clinical outcomes, and safety of Impella-supported HRPCI in the PROTECT III study. METHODS: We evaluated sex-based differences in the PROTECT III study; a prospective, multicenter, observational study of patients undergoing Impella-supported HRPCI. The primary outcome was 90-day major adverse cardiac and cerebrovascular events (MACCE)-the composite of all-cause death, myocardial infarction, stroke/transient ischemic attack, and repeat revascularization. RESULTS: From March 2017 to March 2020, 1,237 patients (27% female) were enrolled. Female patients were older, more often Black, more often anemic, and had more prior strokes and worse renal function, but higher ejection fractions compared to male patients. Preprocedural SYNTAX score was similar between sexes (28.0 ± 12.3). Female patients were more likely to present with acute myocardial infarction (40.7% vs 33.2%; P = 0.02) and more often had femoral access used for PCI and nonfemoral access used for Impella device implantation. Female patients had higher rates of immediate PCI-related coronary complications (4.2% vs 2.1%; P = 0.004) and a greater drop in SYNTAX score post-procedure (-22.6 vs -21.0; P = 0.04). There were no sex differences in 90-day MACCE, vascular complications requiring surgery, major bleeding, or acute limb ischemia. After adjustment using propensity matching and multivariable regression, immediate PCI-related complications was the only safety or clinical outcome that was significantly different by sex. CONCLUSIONS: In this study, rates of 90-day MACCE compared favorably to prior cohorts of HRPCI patients and there was no significant sex differences. (The PROTECT III Study is a substudy of The Global cVAD Study [cVAD]; NCT04136392).

Colchicine and high-intensity rosuvastatin in the treatment of non-critically ill patients hospitalised with COVID-19: a randomised clinical trial.

OBJECTIVE: To evaluate the effect of colchicine and high-intensity rosuvastatin in addition to standard of care on the progression of COVID-19 disease in hospitalised patients. DESIGN: A pragmatic, open-label, multicentre, randomised controlled trial conducted from October 2020 to September 2021. Follow-up was conducted at 30 and 60 days. The electronic medical record was used at all stages of the trial including screening, enrolment, randomisation, event ascertainment and follow-up. SETTING: Four centres in the Yale New Haven Health System. PARTICIPANTS: Non-critically ill hospitalised patients with COVID-19. INTERVENTIONS: Patients were randomised 1:1 to either colchicine plus high-intensity rosuvastatin in addition to standard of care versus standard of care alone. Assigned treatment was continued for the duration of index hospitalisation or 30 days, whichever was shorter. PRIMARY AND SECONDARY OUTCOME MEASURES: The prespecified primary endpoint was progression to severe COVID-19 disease (new high-flow or non-invasive ventilation, mechanical ventilation, need for vasopressors, renal replacement therapy or extracorporeal membrane oxygenation, or death) or arterial/venous thromboembolic events (ischaemic stroke, myocardial infarction, deep venous thrombosis or pulmonary embolism) evaluated at 30 days. RESULTS: Among the 250 patients randomised in this trial (125 to each arm), the median age was 61 years, 44% were women, 15% were Black and 26% were Hispanic/Latino. As part of the standard of care, patients received remdesivir (87%), dexamethasone (92%), tocilizumab (18%), baricitinib (2%), prophylactic/therapeutic anticoagulation (98%) and aspirin (91%). The trial was terminated early by the data and safety monitoring board for futility. No patients were lost to follow-up due to electronic medical record follow-up. There was no significant difference in the primary endpoint at 30 days between the active arm and standard of care arm (15.2% vs 8.8%, respectively, p=0.17). CONCLUSIONS: In this small, open-label, randomised trial of non-critically ill hospitalised patients with COVID-19, the combination of colchicine and rosuvastatin in addition to standard of care did not appear to reduce the risk of progression of COVID-19 disease or thromboembolic events, although the trial was underpowered due to a lower-than-expected event rate. The trial leveraged the power of electronic medical records for efficiency and improved follow-up and demonstrates the utility of incorporating electronic medical records into future trials. TRIAL REGISTRATION: NCT04472611.

Blood pressure response to commonly administered antihypertensives for severe inpatient hypertension.

BACKGROUND: Blood pressure (BP) elevations are commonly treated in hospitalized patients; however, treatment is not guideline directed. Our objective was to assess BP response to commonly prescribed antihypertensives after the development of severe inpatient hypertension (HTN). METHODS: This is a cohort study of adults, excluding intensive care unit patients, within a single healthcare system admitted for reasons other than HTN who developed severe HTN (systolic BP>180 or diastolic BP >110 mmHg at least 1 hour after admission). We identified the most commonly administered antihypertensives given within 6 hours of severe HTN (given to >10% of treated patients). We studied the association of treatment with each antihypertensive vs. no treatment on BP change in the 6 hours following severe HTN development using mixed-effects model after adjusting for demographics and clinical characteristics. RESULTS: Among 23,147 patients who developed severe HTN, 9,166 received antihypertensive treatment. The most common antihypertensives given were oral metoprolol (n = 1991), oral amlodipine (n = 1812), oral carvedilol (n = 1116), IV hydralazine (n = 1069) and oral hydralazine (n = 953). In the fully adjusted model, treatment with IV hydralazine led to 13 [-15.9, -10.1], 18 [-22.2, -14] and 11 [-14.1, -8.3] mmHg lower MAP, SBP, and DBP in the 6 hours following severe HTN development compared to no treatment. Treatment with oral hydralazine and oral carvedilol also resulted in significantly lower BPs in the 6 hours following severe HTN development (6 [-9.1, -2.1 and -7 [-9.1, -4.2] lower MAP, respectively) compared to no treatment. Receiving metoprolol and amlodipine did not result in a drop in BP compared to no treatment. CONCLUSION: Among commonly used antihypertensives, IV hydralazine resulted in the most significant drop in BP following severe HTN, while metoprolol and amlodipine did not lower BP. Further research to assess the effect of treatment on clinical outcomes and if needed which antihypertensives to administer are necessary.

ST-Segment Elevation Myocardial Infarction: Sex Differences in Incidence, Etiology, Treatment, and Outcomes.

PURPOSE: Although there have been marked improvements in the standard of care for treatment of ST-elevation myocardial infarction, women, especially younger women, continue to have significantly worse outcomes than men. RECENT FINDINGS: This review highlights the current sex differences in presentation, etiology, treatment, and outcomes among these patients in order to make providers aware of the heterogeneous entities that cause ST-elevation myocardial infarction particularly in women and of disparities in treatment that lead to poorer outcomes in women. Furthermore, it emphasizes evidence-based strategies including standardized protocols for early revascularization, mechanical circulatory support, and access methodology that can reduce sex-based disparities in treatments and outcomes.

Severe inpatient hypertension prevalence and blood pressure response to antihypertensive treatment.

Severe hypertension (HTN) that develops during hospitalization is more common than admission for HTN; however, it is poorly studied, and treatment guidelines are lacking. Our goal is to characterize hospitalized patients who develop severe HTN and assess blood pressure (BP) response to treatment. This is a multi-hospital retrospective cohort study of adults admitted for reasons other than HTN who developed severe HTN. The authors defined severe inpatient HTN as the first documented BP elevation (systolic BP > 180 or diastolic BP > 110) at least 1 hour after admission. Treatment was defined as receiving antihypertensives (intravenous [IV] or oral) within 6h of BP elevation. As a measure of possible overtreatment, the authors studied the association between treatment and time to mean arterial pressure (MAP) drop ≥ 30% using the Cox proportional hazards model. Among 224 265 hospitalized adults, 10% developed severe HTN of which 40% were treated. Compared to patients who did not develop severe HTN, those who did were older, more commonly women and black, and had more comorbidities. Incident MAP drop ≥ 30% among treated and untreated patients with severe HTN was 2.2 versus 5.7/1000 person-hours. After adjustment, treated versus. untreated patients had lower rates of MAP drop ≥ 30% (hazard rate [HR]: 0.9 [0.8, 0.99]). However, those receiving only IV treatment versus untreated had greater rates of MAP drop ≥ 30% (1.4 [1.2, 1.7]). Overall, the authors found that clinically significant MAP drop is observed among inpatients with severe HTN irrespective of treatment, with greater rates observed among patients treated only with IV antihypertensives. Further research is needed to phenotype inpatients with severe HTN.

Excessive Blood Pressure Response to Clonidine in Hospitalized Patients With Asymptomatic Severe Hypertension.

BACKGROUND: There are limited and nonconcordant data on the rapidity and safety of blood pressure response to clonidine in the setting of asymptomatic severe hypertension. We evaluated the blood pressure response to clonidine in hospitalized patients with asymptomatic severe hypertension. METHODS: We performed a review of hospitalized, noncritically ill patients receiving clonidine within 6 hours of developing asymptomatic severe hypertension (systolic blood pressure [SBP] >180 or diastolic blood pressure [DBP] >110 mm Hg in the absence of acute hypertension-mediated target organ damage). The incidence of mean arterial pressure (MAP) reduction by ≥30% at 4 hours after clonidine was the primary endpoint. RESULTS: We identified 200 relevant patient encounters (median age 63 years, 48.5% women). Median time to clonidine following asymptomatic severe hypertension was 2.8 hours. A total of 20 (10%) patients had ≥30% MAP reduction within 4 hours after clonidine, and 32 (16%) patients had ≥30% reduction in either SBP, DBP, or MAP. Older age, female sex, and preexisting vascular disease were associated with ≥30% MAP reductions (P < 0.05). Only patient sex and clonidine dose of 0.3 mg were significant in multivariable models. There were 14 adverse events observed within 24 hours of administration of clonidine; most (9) were acute kidney injury. There were no ischemic (myocardial, cerebrovascular) events. CONCLUSIONS: A substantial minority of hospitalized patients with asymptomatic severe hypertension experience precipitous blood pressure decline with clonidine, and though blood pressure declines more precipitously in women and those receiving higher doses (0.3 mg specifically), the response to clonidine is generally not predictable on clinical grounds.

Long term outcomes of ultrathin versus standard thickness second-generation drug eluting stents: Meta-analysis of randomized trials.

OBJECTIVE: Identify the effect of ultrathin drug eluting stents on long term outcomes in coronary artery disease. BACKGROUND: Although second-generation drug eluting stents (DES) are superior to first-generation DES, persistence of adverse outcomes has led to continued refinement in design. Ultrathin second-generation DES have been shown to improve outcomes at 1-year follow-up. Beyond 1-year their effect remains unknown. METHODS: PubMed, Embase and Cochrane Database were searched for randomized controlled trials that compared ultrathin (defined as <70 um) to standard thickness second-generation DES. Studies were chosen according to the PROSPERO protocol (CRD42020185374). Data from randomized controlled trials were pooled using random-effects model (Mantel-Haenszel). The primary outcome was target lesion failure (TLF) at 2 years, a composite of cardiac death, target vessel myocardial infarction, and ischemia-driven target vessel revascularization. Secondary outcomes included TLF at 3 and 5 years, the components of TLF and definite or probable stent thrombosis. Differences in outcomes between groups were presented in Forest plots as risk ratios (RR) with corresponding 95% confidence intervals (CIs) for each trial. RESULTS: We identified 18 publications from 10 trials with14,649 patients. At 2-years there was a significant 12% reduction in TLF (RR, 0.88; 95% CI 0.78-0.99; p < 0.05) associated with the use of ultrathin DES. At 3-years, there was a significant 19% reduction in TLF with ultrathin DES (RR, 0.79; 95% CI 0.64-0.98; p < 0.05). CONCLUSION: In patients undergoing percutaneous coronary intervention, ultrathin DES improve long term clinical outcomes.

Ceftazidime induced liver injury.

A 65-year-old woman with type II diabetes mellitus complicated by non-healing ulcers with recurrent osteomyelitis was admitted for progression of cellulitis after treatment failure with an outpatient course of amoxicillin-clavulanate. She was found to have persistent osteomyelitis and started on ceftazidime for a culture documented Pseudomonas aeruginosa infection. After two parenteral doses, she had a rapid rise in liver function tests (LFTs) in a hepatocellular pattern. Due to rapid identification, all medications with potential hepatotoxicity, including ceftazidime, were discontinued and the LFTs promptly returned to baseline over 3 days. Of note, the patient did not experience any symptoms of liver injury. Other causes of acute liver injury were effectively ruled out, but the case was confounded by usage of other potential hepatotoxic medications. Still, the most likely culprit was ceftazidime, a rare cause of drug induced liver injury with very few reports in the literature.

Design and rationale of the colchicine/statin for the prevention of COVID-19 complications (COLSTAT) trial.

BACKGROUND: Despite improvement in the standard of care (SOC) for hospitalized COVID-19 patients, rates of morbidity and mortality remain high. There continues to be a need for easily available and cost-effective treatments. Colchicine and rosuvastatin are both safe and well-studied medications with anti-inflammatory and other pleiotropic effects that may provide additional benefits to hospitalized COVID-19 patients. METHODS AND RESULTS: The Colchicine/Statin for the Prevention of COVID-19 Complications (COLSTAT) trial is a pragmatic, open-label, multicenter, randomized trial comparing the combination of colchicine and rosuvastatin in addition to SOC to SOC alone in hospitalized COVID-19 patients. Four centers in the Yale New Haven Health network will enroll a total of 466 patients with 1:1 randomization. The trial will utilize the electronic health record (Epic® Systems, Verona, Wisconsin, USA) at all stages including screening, randomization, intervention, event ascertainment, and follow-up. The primary endpoint is the 30-day composite of progression to severe COVID-19 disease as defined by the World Health Organization ordinal scale of clinical improvement and arterial/venous thromboembolic events. The secondary powered endpoint is the 30-day composite of death, respiratory failure requiring intubation, and myocardial injury. CONCLUSIONS: The COLSTAT trial will provide evidence on the efficacy of repurposing colchicine and rosuvastatin for the treatment of hospitalized COVID-19 patients. Moreover, it is designed to be a pragmatic trial that will demonstrate the power of using electronic health records to improve efficiency and enrollment in clinical trials in an adapting landscape. CLINICAL TRIAL REGISTRATION: NCT04472611 (https://clinicaltrials.gov/ct2/show/NCT04472611).

Meta-Analysis of Gender Disparities in In-hospital Care and Outcomes in Patients with ST-Segment Elevation Myocardial Infarction.

Gender disparities in ST-segment elevation myocardial infarction (STEMI) outcomes continue to be reported worldwide; however, the magnitude of this gap remains unknown. To evaluate gender-based discrepancies in clinical outcomes and identify the primary driving factors a global meta-analysis was performed. Studies were selected if they included all comers with STEMI, reported gender specific patient characteristics, treatments, and outcomes, according to the registered PROSPERO protocol: CRD42020161469. A total of 56 studies (705,098 patients, 31% females) were included. Females were older, had more comorbidities and received less antiplatelet therapy and primary percutaneous coronary intervention (PCI). Females experienced significantly longer delays to first medical contact (mean difference 42.5 min) and door-to-balloon time (mean difference 4.9 min). In-hospital, females had increased rates of mortality (odds ratio [OR] 1.91, 95% confidence interval [CI] 1.84 to 1.99, p <0.00001), repeat myocardial infarction (MI) (OR 1.25, 95% CI 1.00 to 1.56, p=0.05), stroke (OR 1.67, 95% CI 1.27 to 2.20, p <0.001), and major bleeding (OR 1.82, 95% CI 1.56 to 2.12, p <0.00001) compared with males. Older age at presentation was the primary driver of excess mortality in females, although other factors including lower rates of primary PCI and aspirin usage, and longer door-to-balloon times contributed. In contrast, excess rates of repeat MI and stroke in females appeared to be driven, at least in part, by lower use of primary PCI and P2Y12 inhibitors, respectively. In conclusion, despite improvements in STEMI care, women continue to have in-hospital rates of mortality, repeat MI, stroke, and major bleeding up to 2-fold higher than men. Gender disparities in in-hospital outcomes can largely be explained by age differences at presentation but comorbidities, delays to care and suboptimal treatment experienced by women may contribute to the gender gap.

A GIS approach to the development of a segment-level derailment prediction model.

Train related accidents, particularly derailments, can lead to severe consequences especially when they involve injuries or fatalities or when they involve hazardous materials that might result in environmental impacts. Whereas numerous road safety studies have suggested appropriate approaches to predicting vehicle-to-vehicle collisions, very few railway safety studies have considered predicting the number of derailments on rail tracks in North America. In addition, the existing few rail safety assessment and derailment prediction models have often been constrained by aggregated data limiting the safety assessments by, for example, failing to consider segment-level characteristics. This paper focused on the development of an integrated database for the development of a segment-level derailment prediction model for Canada's rail network. The primary objective of this paper is to report how challenges in the data integration process were overcome and also to develop a network screening tool to identify segments with high derailment risk in Canada's rail network. Negative binomial regression and the Empirical Bayes technique were used to estimate the predicted number of derailments on Canada's rail network at the segment level. A network screening process was then successfully applied to identify key segments of safety concern: the top ten segments of concern accounted for approximately 1% of the rail network allowing decision makers to focus their derailment mitigation efforts on a manageable part of Canada's vast rail network. The data processing approach and analysis in this study have strong implications for advancing research on rail safety in North America.

Examining weather-related factors on physical activity levels of children from rural communities.

OBJECTIVE: The objective was to examine the influence of weather on moderate-to-vigorous physical activity (MVPA) and light physical activity (LPA) levels of children aged 8-14 years from rural communities, an understudied Canadian population. METHODS: Children (n = 90) from four communities in rural Northwestern Ontario participated in this study between September and December 2016. Children's MVPA and LPA were measured using an Actical accelerometer and demographic data were gathered from surveys of children and their parents. Weather data were collected from the closest weather station. Cross-classified regression models were used to assess the relationship between weather and children's MVPA and LPA. RESULTS: Boys accumulated more MVPA than girls (b = 26.38, p < 0.01), children were more active on weekdays as compared with weekends (b = - 16.23, p < 0.01), children were less active on days with precipitation (b = - 22.88, p < 0.01), and higher temperature led to a significant increase in MVPA (b = 1.33, p < 0.01). As children aged, they accumulated less LPA (b = - 9.36, p < 0.01) and children who perceived they had higher levels of physical functioning got more LPA (b = 25.18, p = 0.02). Similar to MVPA, children had higher levels of LPA on weekdays (b = - 37.24, p < 0.01) as compared to weekend days and children accumulated less LPA (b = -50.01, p < 0.01) on days with rain. CONCLUSION: The study findings indicate that weather influences rural children's MVPA and LPA. Future research is necessary to incorporate these findings into interventions to increase rural children's overall PA levels and improve their overall health.

RéSUMé: OBJECTIF: Examiner l'influence de la météo sur les niveaux d'activité physique modérée à vigoureuse (APMV) et d'activité physique légère (APL) des enfants de 8 à 14 ans vivant en milieu rural, une population canadienne sous-étudiée. MéTHODE: Des enfants (n = 90) de quatre communautés rurales du Nord-Ouest de l'Ontario ont participé à l'étude entre septembre et décembre 2016. Leurs niveaux d'APMV et d'APL ont été mesurés à l'aide d'un accéléromètre de marque Actical, et leurs données démographiques ont été obtenues en sondant les enfants et leurs parents. Les données météorologiques ont été obtenues auprès de la station météorologique la plus proche. Des modèles de régression recoupés ont servi à analyser la relation entre la météo et l'APMV et l'APL des enfants. RéSULTATS: Les garçons ont accumulé plus d'APMV que les filles (b = 26,38 p < 0,01); les enfants étaient plus actifs les jours de semaine que les fins de semaine (b = -16,23 p < 0,01); les enfants étaient moins actifs les jours avec précipitations (b = -22,88 p < 0,01); et les températures élevées étaient associées à une augmentation significative de l'APMV (b = 1,33 p < 0,01). En grandissant, les enfants accumulaient moins d'APL (b = -9,36 p < 0,01) et les enfants qui pensaient avoir des niveaux d'activité physique plus élevés accumulaient plus d'APL (b = 25,18 p = 0,02). Comme pour l'APMV, les enfants avaient des niveaux d'APL plus élevés les jours de semaine (b = -37,24 p < 0,01) que les fins de semaine, et les enfants accumulaient moins d'APL (b = -50,01 p < 0,01) les jours de pluie. CONCLUSION: Les constatations de l'étude montrent que la météo influence l'APMV et l'APL des enfants en milieu rural. Il faudrait pousser la recherche pour intégrer ces constatations dans des interventions pour faire augmenter les niveaux d'activité physique globaux des enfants en milieu rural et améliorer leur santé globale.

On Aqua-Based Silica (SiO2-Water) Nanocoolant: Convective Thermal Potential and Experimental Precision Evaluation in Aluminum Tube Radiator.

Although the research on potential use of nanofluids in automotive vehicles is in its embryonic stage, a number of studies have suggested the strong prospect of nanofluids for the efficient thermal management of automotive vehicles. Nevertheless, the pinnacle of nanofluid-based systems awaits stable nanoparticle suspension. The present work studies the heat transfer performance of an aluminum tube automotive radiator with 31 flattened tubes and louvered fins using water and different concentrations (0.04, 0.08, and 0.12 vol.%)-based SiO2/water nanofluids as the engine coolant. Inlet temperature and flowrate of the fluid were varied from 60 to 70 °C and 12 to 18 LPM, respectively. The topmost increment in heat transfer rate of 36.92% and Nusselt number of 45.53% were observed in the upper range of tested operational parameters, however, the relative heat transfer increment percentage dropped from 5% (between 0.04 and 0.08 vol.%) to 3.5% (between 0.08 and 0.12 vol.%) due to agglomeration and cluster formation caused by the presence of a greater number of nanoparticles. Precise evaluation of the experimental results was also carried out by reperforming the tests after three days of initial experimentations. A mere deviation of less than 1% was observed between the initial and repeated tests, however, the decline was caused due to the synergistic effects of clustering and fouling.