3,234 research outputs found
Osteosarcopenia later in life: Prevalence and associated risk factors
Background and aims: The identification of risk factors for osteosarcopenia in older adults is important for planning preventative strategies in clinical practice. Therefore, our study aimed to investigate the prevalence and risk factors associated with osteosarcopenia in older adults using different diagnostic criteria. / Methods: The sample included 171 community-dwelling older adults with a mean age of 79.4 ± 5.9 years and mean body mass index of 25.67 ± 4.70 kg/m2. We analyzed sociodemographic, biomarkers, lifestyle, and health condition data from participants of the “Projeto Idosos - Goiânia” cohort study. The outcome osteosarcopenia was defined as the simultaneous occurrence of sarcopenia and osteopenia. Osteopenia was diagnosed by low lumbar spine bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA). Sarcopenia was diagnosed using handgrip dynamometry and appendicular skeletal mass index assessed by DEXA following the criteria of the two European consensuses on sarcopenia (2010 and 2018). Two osteosarcopenia outcome variables were evaluated: OsteoSarc1 and OsteoSarc2 using the 2010 and 2018 European sarcopenia consensus criteria, respectively. Multivariate Poisson regression analysis was used to calculate the prevalence ratios (PRs). / Results: The prevalence of OsteoSarc1 and OsteoSarc2 were 12.8% and 7.2%, respectively, with no significant gender differences. OsteoSarc1 was associated with low potassium (PR: 3.39, 95% confidence interval [CI]: 1.10–10.43) and malnutrition (PR: 3.84, 95% CI: 1.78–8.30). OsteoSarc2 was associated with being ≥80 years (PR: 7.64, 95% CI: 1.57–37.07), >4 years of education (PR: 3.25, 95% CI: 1.03–10.22), alcohol consumption (PR: 2.41, 95% CI: 1.01–5.77), low potassium (PR: 2.22, 95% CI: 1.45–6.87), low serum vitamin D (PR: 4.47, 95% CI: 1.68–11.88), and malnutrition (PR: 5.00, 95% CI: 1.06–23.51). / Conclusions: OsteoSarc1 had a higher prevalence. The risk factors associated with the two outcomes were malnutrition and potassium level, as well as other risk factors, such as alcohol consumption and low vitamin D level. These findings may contribute to the prevention or treatment of this health condition in older adults
How Are Epigenetic Modifications Related to Cardiovascular Disease in Older Adults?
The rate of aging has increased globally during recent decades and has led to a rising burden of age-related diseases such as cardiovascular disease (CVD). At the molecular level, epigenetic modifications have been shown recently to alter gene expression during the life course and impair cellular function. In this regard, several CVD risk factors, such as lifestyle and environmental factors, have emerged as key factors in epigenetic modifications within the cardiovascular system. In this study, we attempted to summarized recent evidence related to epigenetic modification, inflammation response, and CVD in older adults as well as the effect of lifestyle modification as a preventive strategy in this age group. Recent evidence showed that lifestyle and environmental factors may affect epigenetic mechanisms, such as DNA methylation, histone acetylation, and miRNA expression. Several substances or nutrients such as selenium, magnesium, curcumin, and caffeine (present in coffee and some teas) could regulate epigenetics. Similarly, physical inactivity, alcohol consumption, air pollutants, psychological stress, and shift working are well-known modifiers of epigenetic patterns. Understanding the exact ways that lifestyle and environmental factors could affect the expression of genes could help to influence the time of incidence and severity of aging-associated diseases. This review highlighted that a healthy lifestyle throughout the life course, such as a healthy diet rich in fibers, vitamins, and essential elements, and specific fatty acids, adequate physical activity and sleep, smoking cessation, and stress control, could be useful tools in preventing epigenetic changes that lead to impaired cardiovascular function
Progression of the first stage of spontaneous labour: A prospective cohort study in two sub-Saharan African countries.
BACKGROUND: Escalation in the global rates of labour interventions, particularly cesarean section and oxytocin augmentation, has renewed interest in a better understanding of natural labour progression. Methodological advancements in statistical and computational techniques addressing the limitations of pioneer studies have led to novel findings and triggered a re-evaluation of current labour practices. As part of the World Health Organization's Better Outcomes in Labour Difficulty (BOLD) project, which aimed to develop a new labour monitoring-to-action tool, we examined the patterns of labour progression as depicted by cervical dilatation over time in a cohort of women in Nigeria and Uganda who gave birth vaginally following a spontaneous labour onset. METHODS AND FINDINGS: This was a prospective, multicentre, cohort study of 5,606 women with singleton, vertex, term gestation who presented at ≤ 6 cm of cervical dilatation following a spontaneous labour onset that resulted in a vaginal birth with no adverse birth outcomes in 13 hospitals across Nigeria and Uganda. We independently applied survival analysis and multistate Markov models to estimate the duration of labour centimetre by centimetre until 10 cm and the cumulative duration of labour from the cervical dilatation at admission through 10 cm. Multistate Markov and nonlinear mixed models were separately used to construct average labour curves. All analyses were conducted according to three parity groups: parity = 0 (n = 2,166), parity = 1 (n = 1,488), and parity = 2+ (n = 1,952). We performed sensitivity analyses to assess the impact of oxytocin augmentation on labour progression by re-examining the progression patterns after excluding women with augmented labours. Labour was augmented with oxytocin in 40% of nulliparous and 28% of multiparous women. The median time to advance by 1 cm exceeded 1 hour until 5 cm was reached in both nulliparous and multiparous women. Based on a 95th percentile threshold, nulliparous women may take up to 7 hours to progress from 4 to 5 cm and over 3 hours to progress from 5 to 6 cm. Median cumulative duration of labour indicates that nulliparous women admitted at 4 cm, 5 cm, and 6 cm reached 10 cm within an expected time frame if the dilatation rate was ≥ 1 cm/hour, but their corresponding 95th percentiles show that labour could last up to 14, 11, and 9 hours, respectively. Substantial differences exist between actual plots of labour progression of individual women and the 'average labour curves' derived from study population-level data. Exclusion of women with augmented labours from the study population resulted in slightly faster labour progression patterns. CONCLUSIONS: Cervical dilatation during labour in the slowest-yet-normal women can progress more slowly than the widely accepted benchmark of 1 cm/hour, irrespective of parity. Interventions to expedite labour to conform to a cervical dilatation threshold of 1 cm/hour may be inappropriate, especially when applied before 5 cm in nulliparous and multiparous women. Averaged labour curves may not truly reflect the variability associated with labour progression, and their use for decision-making in labour management should be de-emphasized
The Analyticity of a Generalized Ruelle's Operator
In this work we propose a generalization of the concept of Ruelle operator
for one dimensional lattices used in thermodynamic formalism and ergodic
optimization, which we call generalized Ruelle operator, that generalizes both
the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator
defined in [Bowen]. We suppose the alphabet is given by a compact metric space,
and consider a general a-priori measure to define the operator. We also
consider the case where the set of symbols that can follow a given symbol of
the alphabet depends on such symbol, which is an extension of the original
concept of transition matrices from the theory of subshifts of finite type. We
prove the analyticity of the Ruelle operator and present some examples
Vitamin D in women with class II/III obesity: Findings from the DieTBra trial
Objective: To assess the prevalence of vitamin D deficiency and factors associated with serum vitamin D levels in adult women with class II/III obesity. Methods: We analysed baseline data from 128 adult women with class II/III obesity i.e. BMI ≥35 kg/m2 who participated in the DieTBra clinical trial. Sociodemographic, lifestyle, sun exposure, sunscreen, dietary intake of calcium and vitamin D, menopause, diseases, medication, and body composition data were analysed using multiple linear regression. Results: 128 women had mean BMI 45.53 ± 6.36, mean age 39.7 ± 8.75 kg/m2 and serum vitamin D 30.02 ng/ml ± 9.80. Vitamin D deficiency was 14.01%. There was no association between serum vitamin D levels and BMI, body fat percentage, total body fat and waist circumference. Age group (p = 0.004), sun exposure/day (p = 0.072), use of sunscreen (p = 0.168), inadequate calcium intake (p = 0.030), BMI (p = 0.192), menopause (p = 0.029) and lipid-lowering drugs (p = 0.150) were included in the multiple linear regression. The following remained associated with low serum vitamin D: being 40–49 years (p = 0.003); ≥50 years of age (p = 0.020) and inadequate calcium intake (p = 0.027). Conclusion: The prevalence of vitamin D deficiency was lower than expected. Lifestyle, sun exposure and body composition were not associated. Age over 40 years and inadequate calcium intake were significantly associated with low serum vitamin D levels
Effects of pre-filmed FeCO3 on flow-induced corrosion and erosion-corrosion in the absence and presence of corrosion inhibitor at 60 °C
In CO2 environments, an increase in the temperature can influence carbon steel flow-induced corrosion (FIC) and erosion-corrosion (EC) degradation processes. Increasing temperature typically results in the acceleration of electrochemical degradation mechanisms in the absence of protective corrosion product layers. Furthermore, the presence of sand in corrosive process fluids could aggravate the service conditions. Although protective iron carbonate (FeCO3) film or/and corrosion inhibitors are capable of suppressing corrosion in CO2-containing environments typical of oil and gas production, their ability to suppress degradation and their associated mechanisms in erosion-corrosion environments is less understood. This work focuses on understanding the ability of FeCO3 to protect the steel surface in the absence and presence of corrosion inhibitor and their interactions in flow-induced and erosion-corrosion systems at 60 °C. The effect of the temperature increase is investigated based on results obtained in a previous study performed at 25 °C. FeCO3 filmed carbon steel specimens were developed using an autoclave at 60 °C, pH 6.6 and 30 bar in a 1.5 wt% NaCl CO2-saturated solution over 48 h. The FeCO3 covered specimens were evaluated in FIC and EC environments at 60 °C and a flow velocity of 15 m/s in the presence and absence of 1000 mg/L sand and 100 ppm of a commercially available corrosion inhibitor. Results indicate that the sole presence of an FeCO3 layer is not sufficient to retard the corrosive process of carbon steel at 60 °C under EC conditions. However, the commercial corrosion inhibitor was observed to worked synergistically with the FeCO3 layer to reduce the corrosion degradation component in both the presence and absence of sand particles. The erosion component is also reduced in erosion-corrosion environments as a result of the combined presence of FeCO3 and corrosion inhibitor
Nidification of Polybia rejecta (Hymenoptera: Vespidae) associated to Azteca chartifex (Hymenoptera: Formicidae) in a fragment of Atlantic Forest, in the state of Minas Gerais, southeastern Brazil
Digital Quantum Simulation of the Statistical Mechanics of a Frustrated Magnet
Many interesting problems in physics, chemistry, and computer science are
equivalent to problems of interacting spins. However, most of these problems
require computational resources that are out of reach by classical computers. A
promising solution to overcome this challenge is to exploit the laws of quantum
mechanics to perform simulation. Several "analog" quantum simulations of
interacting spin systems have been realized experimentally. However, relying on
adiabatic techniques, these simulations are limited to preparing ground states
only. Here we report the first experimental results on a "digital" quantum
simulation on thermal states; we simulated a three-spin frustrated magnet, a
building block of spin ice, with an NMR quantum information processor, and we
are able to explore the phase diagram of the system at any simulated
temperature and external field. These results serve as a guide for identifying
the challenges for performing quantum simulation on physical systems at finite
temperatures, and pave the way towards large scale experimental simulations of
open quantum systems in condensed matter physics and chemistry.Comment: 7 pages for the main text plus 6 pages for the supplementary
material
Effects of exposure to cigarette smoke prior to pregnancy in diabetic rats
<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to evaluate the effects of cigarette smoke exposure before pregnancy on diabetic rats and their offspring development.</p> <p>Methods</p> <p>Diabetes was induced by streptozotocin and cigarette smoke exposure was conducted by mainstream smoke generated by a mechanical smoking device and delivered into a chamber. Diabetic female Wistar rats were randomly distributed in four experimental groups (n minimum = 13/group): nondiabetic (ND) and diabetic rats exposed to filtered air (D), diabetic rats exposed to cigarette smoke prior to and into the pregnancy period (DS) and diabetic rats exposed to cigarette smoke prior to pregnancy period (DSPP). At day 21 of pregnancy, rats were killed for maternal biochemical determination and reproductive outcomes.</p> <p>Results</p> <p>The association of diabetes and cigarette smoke in DSPP group caused altered glycemia at term, reduced number of implantation and live fetuses, decreased litter and maternal weight, increased pre and postimplantation loss rates, reduced triglyceride and VLDL-c concentrations, increased levels of thiol groups and MDA. Besides, these dams presented increased SOD and GSH-Px activities. However, the increased antioxidant status was not sufficient to prevent the lipid peroxidation observed in these animals.</p> <p>Conclusion</p> <p>Despite the benefits stemming from smoking interruption during the pregnancy of diabetic rats, such improvement was insufficient to avoid metabolic alterations and provide an adequate intrauterine environment for embryofetal development. Therefore, these results suggest that it is necessary to cease smoking extensive time before planning pregnancy, since stopping smoking only when pregnancy is detected may not contribute effectively to fully adequate embryofetal development.</p
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