9 research outputs found

    Thermophysical properties of IoNanofluids composed of 1-ethyl-3- methylimidazolium thiocyanate and carboxyl-functionalized long multi-walled carbon nanotubes

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    The concept of IoNanofluids (INFs) as the stable dispersions of nanoparticles in ionic liquids was proposed in 2009 by Nieto de Castro’s group. INFs characterize exciting properties such as improved thermal conductivity, non-volatility, and non-flammability. This work is a continuation of our studies on the morphology and physicochemistry of carbon-based nanomaterials a ecting thermal conductivity, viscosity, and density of INFs. We focus on the characterization of dispersions composed of long carboxylic group-functionalized multi-walled carbon nanotubes and 1-ethyl-3-methylimidazolium thiocyanate. The thermal conductivity of INFs was measured using KD2 Pro Thermal Properties Analyzer (Decagon Devices Inc., Pullman, WA, USA). The viscosity was investigated using rotary viscometer LV DV-II+Pro (Brookfield Engineering, Middleboro, MA, USA). The density of INFs was measured using a vibrating tube densimeter Anton Paar DMA 5000 (Graz, Austria). The maximum thermal conductivity enhancement of 22% was observed for INF composed of 1 wt% long carboxylic group-functionalized multi-walled carbon nanotubes

    Assessment of saddle fit in racehorses using infrared thermography

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    The aim of this study was to assess the influence of horse, saddle, and rider on saddle fit in racehorses by detecting pressure distribution using infrared thermography. In this study, 22 saddles used on 65 racing horses ridden by 21 riders were used. Data from horses including gender, breed, age, training intensity, and level of performance were collected. Type and mass of the saddle were also obtained, along with information about the rider's body mass and riding skills. Thermographic images of the saddle's panels were captured immediately after untacking the horse at each thermographic examination. On each thermographic image of the saddle panels, six regions of interest (ROIs) were marked, with mean temperature calculated within each ROI to indicate pressure distribution. Saddle fit was evaluated for right/left panel pressure, bridging/rocking pressure, and front/back pressure according to horse's: gender, breed, age, training intensity, level of conditioning, rider's skills, and load (saddle plus rider mass). There were statistically significant relationships (P < .05) between left/right asymmetry and age, training, intensity and load. In front/back pressure, there was a statistically significant relationship (P < .05) for load. No statistically significant relationships were observed between bridging/rocking pressure and the rest of the aforementioned variables. The study indicated that load, horse age, and training intensity influence pressure distribution in racing saddles. Therefore, animal age and load have to be considered in saddle fit. Infrared thermography has been confirmed as a useful tool in the evaluation of saddle fit in racing horses

    Cardiovascular risk factors as determinants of cerebral blood flow - a cross-sectional and 6-year follow-up study

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    Purpose: The parameters of cerebral blood flow are modulated by many factors. The aim of the study was to prospectively assess the relationship between the number of the established cardiovascular risk factors and hemodynamic parameters of cerebral blood flow. Material and methods: The study was cross-sectional baseline and 6-year follow-up data analysis. We analyzed data regarding cardiovascular risk factors, medications use, and ultrasonographically (transcranial Doppler) obtained mean cerebral blood flow velocity (mCBFV), pulsatility (PI), resistance (RI) indexes of middle cerebral artery. Results: After 6.0 ± 0.6 years of follow-up, there was increase in systolic (p = .047), and decrease in diastolic (p = .005) blood pressure, resulting in greater pulse pressure (p < .001). Although intima-media thickness increased during follow-up (p = .019), PI, RI and mCBFV did not differ between baseline and follow-up. In the cohort without follow-up (n = 112), we observed strong association between number of studied cardiovascular risk factors and lower mCBFV, and higher PI and RI (all p < .001), in the cohort with 6 year follow-up (n = 53), we confirmed similar association for mCBFV and PI (p = .002) at baseline, and mCBFV (p = .024) after follow-up. During follow-up, more patients were treated with vasoactive medications (p < .05). Also the median (interquartile range) of total number of taken drugs at follow-up 2 (1–3) was greater than at baseline 1 (0–2), (p < .001). The addition of vasoactive medications during follow-up was associated with increase of the mCBFV (0.012 ± 0.02 m/s, p = .013). Conclusion: The parameters of the cerebral blood flow are adversely influenced by accretion of cardiovascular risk factors, both at baseline and after 6 years of follow-up. The addition of a vasoactive medication during follow-up is associated with an increase of the mCBFV, a possibly beneficial effect

    Association of Office and Ambulatory Blood Pressure With Mortality and Cardiovascular Outcomes

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    Importance: Blood pressure (BP) is a known risk factor for overall mortality and cardiovascular (CV)-specific fatal and nonfatal outcomes. It is uncertain which BP index is most strongly associated with these outcomes. Objective: To evaluate the association of BP indexes with death and a composite CV event. Design, Setting, and Participants: Longitudinal population-based cohort study of 11 135 adults from Europe, Asia, and South America with baseline observations collected from May 1988 to May 2010 (last follow-ups, August 2006-October 2016). Exposures: Blood pressure measured by an observer or an automated office machine; measured for 24 hours, during the day or the night; and the dipping ratio (nighttime divided by daytime readings). Main Outcomes and Measures: Multivariable-adjusted hazard ratios (HRs) expressed the risk of death or a CV event associated with BP increments of 20/10 mm Hg. Cardiovascular events included CV mortality combined with nonfatal coronary events, heart failure, and stroke. Improvement in model performance was assessed by the change in the area under the curve (AUC). Results: Among 11 135 participants (median age, 54.7 years, 49.3% women), 2836 participants died (18.5 per 1000 person-years) and 2049 (13.4 per 1000 person-years) experienced a CV event over a median of 13.8 years of follow-up. Both end points were significantly associated with all single systolic BP indexes (P < .001). For nighttime systolic BP level, the HR for total mortality was 1.23 (95% CI, 1.17-1.28) and for CV events, 1.36 (95% CI, 1.30-1.43). For the 24-hour systolic BP level, the HR for total mortality was 1.22 (95% CI, 1.16-1.28) and for CV events, 1.45 (95% CI, 1.37-1.54). With adjustment for any of the other systolic BP indexes, the associations of nighttime and 24-hour systolic BP with the primary outcomes remained statistically significant (HRs ranging from 1.17 [95% CI, 1.10-1.25] to 1.87 [95% CI, 1.62-2.16]). Base models that included single systolic BP indexes yielded an AUC of 0.83 for mortality and 0.84 for the CV outcomes. Adding 24-hour or nighttime systolic BP to base models that included other BP indexes resulted in incremental improvements in the AUC of 0.0013 to 0.0027 for mortality and 0.0031 to 0.0075 for the composite CV outcome. Adding any systolic BP index to models already including nighttime or 24-hour systolic BP did not significantly improve model performance. These findings were consistent for diastolic BP. Conclusions and Relevance: In this population-based cohort study, higher 24-hour and nighttime blood pressure measurements were significantly associated with greater risks of death and a composite CV outcome, even after adjusting for other office-based or ambulatory blood pressure measurements. Thus, 24-hour and nighttime blood pressure may be considered optimal measurements for estimating CV risk, although statistically, model improvement compared with other blood pressure indexes was small.status: publishe
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