2,096 research outputs found

    Cardiovascular health effects following exposure of human volunteers during fire extinction exercises

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    Abstract Background Firefighters have increased risk of cardiovascular disease and of sudden death from coronary heart disease on duty while suppressing fires. This study investigated the effect of firefighting activities, using appropriate personal protective equipment (PPE), on biomarkers of cardiovascular effects in young conscripts training to become firefighters. Methods Healthy conscripts (n = 43) who participated in a rescue educational course for firefighting were enrolled in the study. The exposure period consisted of a three-day training course where the conscripts participated in various firefighting exercises in a constructed firehouse and flashover container. The subjects were instructed to extinguish fires of either wood or wood with electrical cords and mattresses. The exposure to particulate matter (PM) was assessed at various locations and personal exposure was assessed by portable PM samplers and urinary excretion of 1-hydroxypyrene. Cardiovascular measurements included microvascular function and heart rate variability (HRV). Results The subjects were primarily exposed to PM in bystander positions, whereas self-contained breathing apparatus effectively abolished pulmonary exposure. Firefighting training was associated with elevated urinary excretion of 1-hydroxypyrene (105%, 95% CI: 52; 157%), increased body temperature, decreased microvascular function (−18%, 95% CI: -26; −9%) and altered HRV. There was no difference in cardiovascular measurements for the two types of fires. Conclusion Observations from this fire extinction training show that PM exposure mainly occurs in situations where firefighters removed the self-contained breathing apparatus. Altered cardiovascular disease endpoints after the firefighting exercise period were most likely due to complex effects from PM exposure, physical exhaustion and increased core body temperature

    A Cost-Effective and Smart Sensing Tissue-like Testbed for Surgical Training

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    A low-cost tissue-like testbed with six nodes of varying stiffness was developed for surgical training to provide pressure and force feedback data through image reception to human operators. Using SolidWorks, a 3D model of the box trainer housing was created. A pad for the distribution of smartsensing nodes and microcontroller connections was designed with open spaces for the respective components. The pad was 3D-printed with PLA filament. Flat piezoelectric pressure sensors were fabricated with conductive materials and velostat sensor material. Using static and dynamic analyses, three top sensors were chosen to be used in three pressure sensing nodes. A calibration process was performed on the pressure sensors to find the linear relationship between voltage and pressure, which was then used to create a conversion equation for each sensor. These equations were used to collect data at the three pressure sensing nodes on the silicone testbed pad. Conductive TPU filament was used to 3D-print vertical force sensors, which were designed using SolidWorks. The force sensors were calibrated with a squeezing mechanism to find a relationship between voltage and force and to subsequently develop a conversion equation for each sensor. We used these equations to collect force data from the three force sensing nodes on the testbed pad. Through static and dynamic analyses, the force sensors were found to be functional, but to need improvements in accuracy. The mechatronic system was designed and developed to integrate all six sensors and to collect data from the testbed pad using an Arduino microcontroller. The flat pressure and vertical force sensors were embedded in each node to measure the pressure and force that occurs during the deformation of the six nodes. Data was collected and imported into MATLAB. This data was used in displaying pressure and force mapping of the nodes over a live video of the silicone pad. Pressure and force mapping was realized by drawing color-coded circles on each of the six nodes that correspond to a range of force or pressure values. From this development, the surgical testbed provides multi-stiffness tissue training with live pressure and force mapping overlaid on a live video of the emulated surgical field

    Circulating endothelial progenitor cells and large artery structure and function in young subjects with uncomplicated Type 1 Diabetes

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    <p>Abstract</p> <p>Background</p> <p>Carotid intima-media thickness (IMT), indices of large artery stiffness and measures of endothelium function may be used as markers of early atherosclerosis in type 1 diabetes mellitus (T1DM). The aim of the present study was to compare the indices of large artery structure and function as well as endothelial function and regenerating capacity between adolescents with T1DM and healthy control of similar age. In addition, the associations of different vascular measures with endothelial progenitor cells (EPCs), glyco-metabolic control and serum levels of advanced glycation endproducts (AGEs), soluble receptors for AGEs (sRAGE) and adiponectin were evaluated.</p> <p>Methods</p> <p>Sixteen uncomplicated young T1DM patients (mean age 18 ± 2 years, history of disease 11 ± 5 years, HbA1c 7.7 ± 1.1%) and 26 controls (mean age 19 ± 2 years) were studied. A radiofrequency-based ultrasound system (Esaote MyLab 70) was used to measure carotid IMT and wave speed (WS, index of local stiffness), applanation tonometry (PulsePen) was applied to obtain central pulse pressure (PP) and augmentation index (AIx), and carotid-femoral pulse wave velocity (PWV, Complior) was used as index of aortic stiffness. Peripheral endothelium-dependent vasodilation was determined as reactive hyperemia index (RHI, EndoPAT). Circulating EPCs, glycometabolic profile, AGEs (autofluorescence method), sRAGE and adiponectin were also measured.</p> <p>Results</p> <p>After adjusting for age, sex and blood pressure, T1DM adolescents had significantly higher carotid IMT (456 ± 7 vs. 395 ± 63 μm, p < 0.005), carotid WS (p < 0.005), PWV (p = 0.01), AIx (p < 0.0001) and central PP (p < 0.01) and lower EPCs (p = 0.02) as compared to controls. RHI was reduced only in diabetic patients with HbA1c ≥7.5% (p < 0.05). In the overall population, EPCs were an independent determinant of carotid IMT (together with adiponectin), while fasting plasma glucose was an independent determinant of carotid WS, AIx and central PP.</p> <p>Conclusions</p> <p>Our findings suggest that young subjects with relatively long-lasting T1DM have a generalized preclinical involvement of large artery structure and function, as well as a blunted endothelium regenerating capacity. Hyperglycemia and suboptimal chronic glycemic control seem to deteriorate the functional arterial characteristics, such as large arteries stiffness, wave reflection and peripheral endothelium-dependent vasodilation, whereas an impaired endothelium regenerating capacity and adiponectin levels seem to influence arterial structure.</p

    Impact of blood glucose variability on carotid artery intima media thickness and distensibility in type 1 diabetes mellitus

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    Aims. Diabetes mellitus is characterized by structural and functional alterations of the large- and medium-size arteries. Whether blood glucose variability, i.e. the glycemic oscillations occurring during the 24-h period, represents a risk factor for vascular alterations additional to and independent on HbA1c in type 1 diabetes mellitus is still undefined. The present study was carried out with the aim at investigating the impact of different measures of blood glucose variability on arterial structure and function. We studied 17 non-complicated type 1 diabetic patients (11 males, six females) with an age of 40.8 ± 7.6 years (mean ± SD). In each patient, 24-h glucose profile was obtained by continuous glucose monitoring system and glucose variability was expressed as mean ± SD of 24-h blood glucose levels, mean amplitude of glycemic excursions and postprandial hyperglycemic spikes. Arterial structure and function was measured as carotid IMT and stiffness. Major findings. The different approaches to assessing blood glucose variability well correlated between and with HbA1c. Carotid IMT and stiffness showed significant correlations with age, blood pressure, heart rate and daily insulin intake but a non- significant correlation with blood glucose variability. Principal conclusion. Thus, in type 1 diabetes mellitus, measures of glycemic variability are useful in predicting both actual and long-lasting glycemic control. In absence of diabetes-related complications and of any intima-media thickness alterations, the major predictors of arterial distensibility are represented by traditional risk factors beside glycemic 24-h control. © 2013 Scandinavian Foundation for Cardiovascular Researc

    Int J Ind Ergon

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    Relevance to Industry:Because the feed force level can affect HTV exposures to bucking bar operators, the feed force required for specific riveting operations should be an important consideration when selecting bucking bar models. This study provides useful information about bucking bar responses to riveting hammer vibrations; this knowledge can improve bucking bar selections.CC999999/Intramural CDC HHS/United States2019-02-19T00:00:00Z30792565PMC6379920vault:3155

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 204

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    This bibliography lists 140 reports, articles, and other documents introduced into the NASA scientific and technical information system in February 1980

    Technology applications

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    A summary of NASA Technology Utilization programs for the period of 1 December 1971 through 31 May 1972 is presented. An abbreviated description of the overall Technology Utilization Applications Program is provided as a background for the specific applications examples. Subjects discussed are in the broad headings of: (1) cancer, (2) cardiovascular disease, (2) medical instrumentation, (4) urinary system disorders, (5) rehabilitation medicine, (6) air and water pollution, (7) housing and urban construction, (8) fire safety, (9) law enforcement and criminalistics, (10) transportation, and (11) mine safety

    Effect and Time Course of Acute Red Wine Consumption on Blood Antioxidant Capacity and Arterial Distensibility in Male Smokers

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    INTRODUCTION/BACKGROUND: Smoking cigarettes leads to oxidative stress and is harmful to endothelial function. Antioxidants found in red wine have been shown to counteract the negative effects of reactive oxygen species. METHODS: The current study investigated antioxidant capacity and vascular performance after smoking cigarettes and consuming wine. Participants included eight male smokers who attended an orientation where baseline anthropometric measures were obtained. Participants were assigned to the wine or control group in a randomized crossover design. The wine group consumed wine immediately following baseline measures of arterial distensibility and providing blood samples. Smoking occurred 15 and 120 minutes following wine consumption. Arterial distensibility measures and blood samples were again collected at these two time points. Controls followed the same procedure but did not consume wine. Outcome variables included plasma antioxidant capacity (FRAP, ORAC) and vascular measures (arterial distensibility). RESULTS: When given wine, the participants’ antioxidant capacity increased in FRAP (P=0.046) but not ORAC. Vascular measures showed a significant difference at time 3 (P=0.030). DISCUSSION/CONCLUSION: The results of the present study suggest drinking red wine while smoking cigarettes increases antioxidant capacity but does not provide health benefits related to vascular performance
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