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Hypertensive disorders of pregnancy and other adverse pregnancy outcomes (APOs) are associated with an increased risk of future maternal cardiovascular disease. Physical activity during pregnancy reduces the risk of these APOs, yet few meet physical activity guidelines during pregnancy. Little is known about the role of sedentary behavior or sleep in APOs, a critical gap in knowledge given these behaviors comprise the majority of a 24-hour day. To address this knowledge gap, the Pregnancy 24/7 cohort study (2020-2025) uses 2 devices for 24-hour activity assessment in each trimester of pregnancy to examine associations of sedentary behavior, sleep, and the 24-hour activity cycle (composition of sedentary behavior, physical activity, and sleep) with hypertensive disorders and other APOs. Participants (n = 500) are recruited from the University of Iowa, University of Pittsburgh, and West Virginia University in early pregnancy and followed through delivery. The activPAL3 micro and Actiwatch Spectrum Plus are worn in each trimester for 7 days of 24-hour wear to assess the 24-hour activity cycle. APOs are abstracted from medical charts. This study will provide critical data to fuel future research examining how modifying the 24-hour activity cycle in pregnancy can improve maternal health.
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Exercício Físico , Resultado da Gravidez , Gravidez , Feminino , Humanos , Estudos de Coortes , Resultado da Gravidez/epidemiologia , Comportamento Sedentário , Projetos de PesquisaRESUMO
Identifying the sources and fate of microplastics in natural systems has garnered a great deal of attention because of their implications for ecosystem health. This work characterizes the size fraction, morphology, color, and polymer composition of microplastics in western Lake Superior and its adjacent harbor sampled in August and September 2021. The results reveal that the overall microplastic counts are similar, with the harbor stations ranging from 0.62 to 3.32 microplastics per liter and the lake stations ranged from 0.83 to 1.4 microplastics per liter. However, meaningful differences between the sample locations can be seen in the size fraction trends and polymer composition. Namely, the harbor samples had relatively larger amounts of the largest size fraction and more diversity of polymer types, which can be attributed to the urbanized activity and shorter water residence time. Power law size distribution modeling reveals deviations that help in the understanding of potential sources and removal mechanisms, although it significantly underpredicts microplastic counts for smaller-sized particles (5-45 µm), as determined by comparison with concurrently collected microplastic samples enumerated by Nile Red staining and flow cytometry.
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Monitoramento Ambiental , Estuários , Lagos , Microplásticos , Microplásticos/análise , Lagos/química , Poluentes Químicos da Água/análiseRESUMO
Plastic pollution, a major environmental crisis, has a variety of consequences for various organisms within aquatic systems. Beyond the direct toxicity, plastic pollution has the potential to absorb biological toxins and invasive microbial species. To better understand the capability of environmental plastic debris to adsorb these species, we investigated the binding of the model protein bovine serum albumin (BSA) to polyethylene (PE) films at various stages of photodegradation. Circular dichroism and fluorescence studies revealed that BSA undergoes structural rearrangement to accommodate changes to the polymer's surface characteristics (i.e., crystallinity and oxidation state) that occur as the result of photodegradation. To understand how protein structure may inform docking of whole organisms, we studied biofilm formation of bacteriaShewanella oneidensison the photodegraded PE. Interestingly, biofilms preferentially formed on the photodegraded PE that correlated with the state of weathering that induced the most significant structural rearrangement of BSA. Taken together, our work suggests that there are optimal physical and chemical properties of photodegraded polymers that predict which plastic debris will carry biochemical or microbial hitchhikers.
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Plásticos , Soroalbumina Bovina , Soroalbumina Bovina/química , Plásticos/química , Animais , Bovinos , Biofilmes , Polietileno/química , FotóliseRESUMO
One solution to minimizing plastic pollution is to improve reuse and recycling strategies. Recycling, however, is limited by the overall degradation of plastics being used, and current techniques for monitoring this plastic degradation fail to observe this in its early stages, which is key for optimizing reusability. This research seeks to develop an inexpensive, reproducible, and nondestructive technique for monitoring degradation of polyethylene (PE) and polypropylene (PP) materials using Nile red as a fluorescent probe. Changes in Nile red's fluorescence spectra were observed upon exposure to stained, aged PE and PP samples. As the surface hydrophobicity of the plastic decreases, Nile red's fluorescence signal undergoes a corresponding signal shift to longer wavelengths (lower energy). The trends seen in the fluorescent profile were related to more commonly used measurements of plastic degradation, namely, the carbonyl index from infrared spectroscopy and bulk crystallinity from calorimetry. Results demonstrate clear trends in fluorescence spectra shifts as related to the chemical and physical changes to the plastics, with trends dependent on the polymer type but independent of polymer film thickness. The strength of this technique is divided into two defined fits of the fluorescence signal; one fit characterizes the degradation throughout the whole range of degradative oxidation and the other is tailored to provide insight into the early stages of degradation. Overall, this work establishes a characterization tool that assesses the extent of plastics' degradation, which may ultimately impact our ability to recover plastics and minimize plastic waste.
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BACKGROUND: Interventions targeting physical activity and sedentary behavior concurrently in pregnancy may be an ideal strategy to reduce the risk of pregnancy complications. We assessed the feasibility, acceptability, and preliminary efficacy of a single-arm, remotely-delivered health coaching intervention to promote physical activity and reduce sedentary behavior in pregnancy. METHODS: Women (n = 34) between 8 and 12 weeks gestation were recruited to take part in the INcreasing Steps in PREgnancy (INSPiRE) study. Participants were given an activity tracker (Fitbit Inspire) and met virtually with their health coach throughout the second and third trimesters of pregnancy. Feasibility was based on enrollment, retention, and adherence rates. Acceptance was assessed using a process evaluation survey. Intervention efficacy was based on activPAL data obtained at baseline and the end of the second trimester. RESULTS: Feasibility objectives were met, with greater than 70% enrollment, 97% retention, and 99% adherence. All participants reported high levels of satisfaction with the program. ActivPAL data indicated statistically significant increases in daily steps (+ 1715.8 steps/day, Cohen's d = 0.97), stepping time (+ 1.9%, d = 0.75), standing time (+ 2.3%, d = 0.29), and decreases in total sedentary time (- 4.2%, d = 0.43) and sedentary bouts of 30 minutes (- 4.1%, d = 0.36) from baseline to the end of the second trimester, all p < 0.05. Decreases were also observed in sedentary bouts of 60 minutes (- 3.9%, d = 0.40), but this was not statistically significant. CONCLUSIONS: The INSPiRE study demonstrated feasibility, high acceptability, and preliminary efficacy for improving movement behaviors in women during pregnancy, supporting future testing in a randomized controlled trial.
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Tutoria , Comportamento Sedentário , Exercício Físico , Estudos de Viabilidade , Feminino , Monitores de Aptidão Física , Humanos , GravidezRESUMO
BACKGROUND: Shorter gestation or smaller birth size are indicators of a suboptimal fetal environment and negatively impact short- and long-term offspring health. Understanding how modifiable maternal behaviours, such as moderate-to-vigorous intensity physical activity (MVPA) or sedentary behaviour (SED), improve fetal outcomes could inform strategies to improve health across the lifespan. OBJECTIVES: The objective of this study was to examine the association of MVPA and SED across pregnancy trimesters on gestational age at delivery and newborn anthropometrics. METHODS: The MoM Health Study measured SED (thigh-mounted activPAL3 micro) and MVPA (waist-worn Actigraph GTX3) in each trimester of pregnancy. Birth outcomes (gestational age at delivery, birthweight, birth length, and head circumference) were abstracted from medical records and used to calculate ponderal index (grams*100/cm3 ) and size-for-gestational age percentiles. Associations of group-based trajectories and trimester-specific SED and MVPA with birth outcomes were analysed using regression models. RESULTS: Low, medium, and high trajectory groups were generated SED and MVPA in 103 and 99 pregnant women, respectively. High vs low SED trajectory was associated with earlier gestational age at delivery (ß -1.03 weeks, 95% CI -2.01, -0.06), larger head circumference (ß 0.83 cm, 95% CI 0.24, 1.63), longer birth length (ß 1.37 cm, 95% CI 0.09, 2.64), and lower ponderal index (ß -0.24 g*100/cm3 , 95% CI -0.42, -0.06), after adjustment for demographics, pre-pregnancy BMI, and (for newborn anthropometric outcomes) gestational age. The association of high SED with lower ponderal index was the most robust across progressively adjusted models (ß -0.25 g*100/cm3 , 95% CI -0.44, -0.07). SED trajectory was not associated with birthweight or size-for-gestational age. High vs low MVPA trajectory was only associated with smaller head circumference (ß -0.86 cm, 95% CI -1.70, -0.02). CONCLUSIONS: Higher SED during pregnancy may result in shorter gestation and inhibited fetal growth. Further research evaluating the effect of reducing SED during pregnancy on birth outcomes is warranted.
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Exercício Físico , Comportamento Sedentário , Peso ao Nascer , Feminino , Humanos , Parto , Gravidez , Trimestres da GravidezRESUMO
We evaluated the effects of a simulated workday of prolonged sitting on blood pressure (BP) and pulse wave velocity (PWV) and examined whether posture (seated vs. supine) affected responses. Participants (n = 25) were adults, with overweight/obesity and elevated BP, and performed seated desk work for 7.5 h. BP and PWV were measured in seated and supine postures at baseline (7:15 a.m.), midday (12:05 p.m.), and afternoon (4:45 p.m.). Generalized linear mixed models evaluated the effects of prolonged sitting on BP and PWV within each posture and interactions by posture and sex. In the recommended postures, seated BP and supine carotid-femoral pulse wave velocity (cfPWV) and carotid-ankle pulse wave velocity (caPWV), but not carotid-radial pulse wave velocity (crPWV), significantly increased over the simulated seated workday (all p < 0.05; effect sizes [d] ranged from 0.25 to 0.44). Whilst no posture-by-time interactions were observed (p > 0.05), BP, caPWV, and crPWV were higher when seated versus supine (main effects of posture p < 0.05; d ranged from 0.30 to 1.04). Exploratory analysis revealed that females had greater seated BP responses (p for interaction <0.05); seated PWV and supine BP and PWV responses were similar by sex (p for interaction >0.05). A simulated workday of prolonged sitting increased seated BP and supine cfPWV and caPWV, and posture minimally influenced these responses. These results add to the evidence suggesting a deleterious effect of prolonged sitting on cardiovascular health.
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Determinação da Pressão Arterial , Pressão Sanguínea , Hipertensão/diagnóstico , Obesidade/diagnóstico , Posicionamento do Paciente , Análise de Onda de Pulso , Comportamento Sedentário , Postura Sentada , Decúbito Dorsal , Rigidez Vascular , Adulto , Estudos Cross-Over , Feminino , Humanos , Hipertensão/fisiopatologia , Descrição de Cargo , Masculino , Pessoa de Meia-Idade , Obesidade/fisiopatologia , Valor Preditivo dos Testes , Fatores de TempoRESUMO
BACKGROUND: Sedentary behavior (SED) is a potential risk factor for poor pregnancy outcomes. We evaluated the validity of several common and one new method to assess SED across three trimesters of pregnancy. METHODS: This cohort study of pregnant women measured objective and self-reported SED each trimester via thigh-worn activPAL3 micro (criterion), waist-worn Actigraph GT3X, and self-report from the Pregnancy Physical Activity Questionnaire (PPAQ) and the de novo Sedentary Behavior Two Domain Questionnaire (SB2D). SED (hours per day) and percent time in SED (SED%) from activPAL were compared to GT3X, SB2D, and PPAQ using Pearson's r, ICC, Bland-Altman analysis, and comparison of criterion SED and SED% across tertiles of alternative methods. RESULTS: Fifty-eight women (mean age 31.5 ± 4.8 years; pre-pregnancy BMI 25.1 ± 5.6 kg/m2; 76% white) provided three trimesters of valid activPAL data. Compared to activPAL, GT3X had agreement ranging from r = 0.54-0.66 and ICC = 0.52-0.65. Bland-Altman plots revealed small mean differences and unpatterned errors, but wide limits of agreement (greater than ±2 h and ± 15%). The SB2D and PPAQ had r < 0.5 and ICC < 0.3 vs. activPAL SED, with lower agreement during the 2nd and 3rd trimesters, and performed poorly in Bland-Altman analyses. SED% from the modified SB2D performed best of the self-reported instruments with modest mean differences, r ranging from 0.55 to 0.60, and ICCs from 0.31-0.33; though, limits of agreement were greater than ±35%. Significant trends in activPAL SED were observed across increasing tertiles of SB2D SED in the 1st and 3rd trimesters (both p ≤ 0.001), but not the 2nd trimester (p = 0.425); and for PPAQ SED in the 1st and 2nd trimesters (both p < 0.05), but not the 3rd trimester (p = 0.158). AcitvPAL SED and SED% increased significantly across tertiles of GT3X SED and SED% as well as SB2D SED% (all p-for-trend ≤ 0.001). CONCLUSIONS: Compared to activPAL, waist-worn GT3X produced moderate agreement, though similar mean estimates of SED across pregnancy. Self-report questionnaires had large absolute error and wide limits of agreement for SED hr./day; SB2D measurement of SED% was the best self-report method. These data suggest activPAL be used to measure SED when possible, followed by GT3X, and - when necessary - SB2D assessing SED% in pregnancy. TRIAL REGISTRATION: www.clinicaltrials.gov NCT03084302 on 3/20/2017.
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Actigrafia/normas , Gestantes/psicologia , Diagnóstico Pré-Natal/normas , Comportamento Sedentário , Autorrelato/normas , Actigrafia/métodos , Actigrafia/psicologia , Adulto , Feminino , Humanos , Gravidez , Trimestres da Gravidez , Diagnóstico Pré-Natal/métodos , Reprodutibilidade dos TestesRESUMO
Sedentary time (ST) has been inconsistently associated with adiposity and cardiorespiratory fitness in children in previous studies. We studied cross-sectional associations of ST, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with fat mass index (FMI) and cardiorespiratory fitness (estimated VO2max). Associations were evaluated with and without considering pattern of ST by bout length. We measured ST and activity by a wrist-worn accelerometer, FMI by bioelectrical impedance, and VO2max by Pacer test in 443 children (51.2% girls, 10.2 ± 0.6 years). Isotemporal substitution regression models estimated the effects of substituting ST, LPA, and MVPA on FMI and VO2max. Further models repeated analyses separating ST into short (<10 min) and long (≥10 min) bouts. Only replacing ST or LPA with MVPA was consistently associated with lower FMI and greater VO2max. When separated by bout length, only one unique association was found where replacing long ST bouts with short ST bouts was associated with lower FMI in girls only. In conclusion, activity pattern is associated with adiposity in girls and fitness in boys and girls. Separating ST into long and short ST bouts may be of minimal importance when assessing associations with adiposity and fitness using wrist-worn accelerometry in children.
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Acelerometria/instrumentação , Adiposidade/fisiologia , Aptidão Cardiorrespiratória , Exercício Físico/fisiologia , Monitores de Aptidão Física , Comportamento Sedentário , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Consumo de Oxigênio/fisiologia , Fatores de TempoRESUMO
Biodegradable polyesters are being increasingly used to replace conventional, nondegradable polymers in agricultural applications such as plastic film for mulching. For many of these applications, poly(butylene adipate- co-terephthalate) (PBAT) is a promising biodegradable material. However, PBAT is also susceptible to photochemical transformations. To better understand how photochemistry affects the biodegradability of PBAT, we irradiated blown, nonstabilized, transparent PBAT films and studied their enzymatic hydrolysis, which is considered the rate-limiting step in polyester biodegradation. In parallel, we characterized the irradiated PBAT films by dynamic mechanical thermal analysis. The rate of enzymatic PBAT hydrolysis decreased when the density of light-induced cross-links within PBAT exceeded a certain threshold. Mass-spectrometric analysis of the enzymatic hydrolysis products of irradiated PBAT films provided evidence for radical-based cross-linking of two terephthalate units that resulted in the formation of benzophenone-like molecules. In a proof-of-principle experiment, we demonstrated that the addition of photostabilizers to PBAT films mitigated the negative effect of UV irradiation on the enzymatic hydrolyzability of PBAT. This work advances the understanding of light-induced changes on the enzyme-mediated hydrolysis of aliphatic-aromatic polyesters and will therefore have important implications for the development of biodegradable plastics.
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Adipatos , Alcenos , Ácidos Ftálicos , PoliésteresRESUMO
Platelet exocytosis is regulated partially by the granular/cellular membrane lipids and proteins. Some platelets contain a membrane-bound tube, called an open canalicular system (OCS), which assists in granular release events and increases the membrane surface area for greater spreading. The OCS is not found in all species, and variations in membrane composition can cause changes in platelet secretion. Since platelet studies use various animal models, it is important to understand how platelets differ in both their composition and granular release to draw conclusions among various models. The relative phospholipid composition of the platelets with (mouse, rabbit) and without (cow) an OCS was quantified using UPLC-MS/MS. Cholesterol and protein composition was measured using an Amplex Red Assay and BCA Assay. TEM and dark field platelet images were gathered and analyzed with Image J. Granular release was monitored with single cell carbon fiber microelectrode amperometry. Cow platelets contained greater amounts of cholesterol and sphingomyelin. In addition, they yield greater serotonin release and longer δ granule secretion times. Finally, they showed greater spreading area with a greater range of spread. Platelets containing an OCS had more similarities in their membrane composition and secretion kinetics compared to cow platelets. However, cow platelets showed greater fusion pore stability which could be due to extra sphingomyelin and cholesterol, the primary components of lipid rafts. In addition, their greater stability may lead to many granules assisting in spreading. This study highlights fundamental membrane differences and their effects on platelet secretion.
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Plaquetas/metabolismo , Membrana Celular/metabolismo , Lipídeos de Membrana/metabolismo , Proteínas de Membrana/metabolismo , Agregação Plaquetária , Animais , Plaquetas/ultraestrutura , Carbono/química , Fibra de Carbono , Bovinos , Membrana Celular/química , Colesterol/química , Colesterol/metabolismo , Cromatografia Líquida de Alta Pressão , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Exocitose , Cinética , Lipídeos de Membrana/química , Proteínas de Membrana/química , Camundongos , Microeletrodos , Microscopia Eletrônica de Transmissão , Coelhos , Especificidade da Espécie , Espectrometria de Massas em TandemRESUMO
OBJECTIVES: Qualitatively assess experiences of occupational pregnancy discrimination. METHODS: A fully remote phenomenological qualitative study was completed leveraging semistructured interviews with a sample of pregnant employees in the United States. Inclusion criteria included being pregnant, working at least 35 hours per week, employed at least 1 year at current employer, and without diagnosed depression/anxiety. RESULTS: Participants (N = 20) were, on average, 30 years of age, worked 42.6 hours per week, self-identified as non-Hispanic black (50%), and earned least a bachelor's degree (85%). Individuals successfully identified various forms of pregnancy discrimination, believing it occurred due to systemic issues or perceptions that women are weak. Most did not report experiences of discrimination fearing retaliation or being unaware of workplace protections. CONCLUSION: Pregnancy discrimination in the workplaces comes in various forms and is an issue for some working pregnant individuals.
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Pesquisa Qualitativa , Local de Trabalho , Humanos , Feminino , Gravidez , Adulto , Local de Trabalho/psicologia , Estados Unidos , Discriminação Social , Entrevistas como Assunto , Gestantes/psicologia , Negro ou Afro-Americano/psicologia , Adulto Jovem , PreconceitoRESUMO
Bile acids play important roles in the human body, and changes in their pool can be used as markers for various liver pathologies. In addition to their functional effects in modulating inflammatory responses and cellular survivability, the unconjugated or conjugated, secondary, or primary nature of bile acids accounts for their various ligand effects. The common hydrophilic bile acids have been used successfully as local treatment to resolve drug-induced cell damage or to ameliorate hearing loss. From various literature references, bile acids show concentration and tissue-dependent effects. Some hydrophobic bile acids act as ligands modulating vitamin D receptors, muscarinic receptors, and calcium-activated potassium channels, important proteins in the inner ear system. Currently, there are limited resources investigating the therapeutic effects of bile acid on hearing loss and little to no information on detecting bile acids in the remote ear system, let alone baseline bile acid levels and their prevalence in healthy and disease conditions. This review presents both hydrophilic and hydrophobic human bile acids and their tissue-specific effects in modulating cellular integrity, thus considering the possible effects and extended therapeutic applicability of bile acids to the inner ear tissue.
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Ácidos e Sais Biliares , Perda Auditiva , Animais , Humanos , Ácidos e Sais Biliares/metabolismo , Ácidos e Sais Biliares/uso terapêutico , Orelha Interna/efeitos dos fármacos , Orelha Interna/metabolismo , Audição/efeitos dos fármacos , Perda Auditiva/tratamento farmacológico , Interações Hidrofóbicas e Hidrofílicas , Ligantes , Receptores de Calcitriol/metabolismo , Receptores Muscarínicos/metabolismoRESUMO
Targeted drug delivery is an ongoing aspect of scientific research that is expanding through the design of micro- and nanoparticles. In this paper, we focus on spray dried microparticles as carriers for a repurposed lipophilic antioxidant (probucol). We characterise the microparticles and quantify probucol prior to assessing cytotoxicity on both control and cisplatin treated hair cells (known as House Ear Institute-Organ of Corti 1; HEI-OC1). The addition of water-soluble polymers to 2% ß-cyclodextrin resulted in a stable probucol formulation. Ursodeoxycholic acid (UDCA) used as formulation excipient increases probucol miscibility and microparticle drug content. Formulation characterisations reveals spray drying results in spherical UDCA-drug microparticles with a mean size distribution of â¼5-12 µm. Probucol microparticles show stable short-term storage conditions accounting for only â¼10% loss over seven days. By mimicking cell culture conditions, both UDCA-probucol (67%) and probucol only (82%) microparticles show drug release in the initial two hours. Furthermore, probucol formulations with or without UDCA preserve cell viability and reduce cisplatin-induced oxidative stress. Mitochondrial bioenergetics results in lower basal respiration and non-mitochondrial respiration, with higher maximal respiration, spare capacity, ATP production and proton leak within cisplatin challenged UDCA-probucol groups. Overall, we present a facile method for incorporating lipophilic antioxidant carriers in polymer-based particles that are tolerated by HEI-OC1 cells and show stable drug release, sufficient in reducing cisplatin-induced reactive oxygen species accumulation.
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Purpose: Mental health is critical for a healthy pregnancy, yet few studies have evaluated its associations with best practice, objectively measured moderate- to vigorous-intensity physical activity (MVPA) or sedentary behavior (SED). This study evaluated associations of MVPA and SED with mental health across pregnancy. Materials and Methods: Two cohort studies (total n = 125, mean [standard deviation] 31 [5] years, and 14.4% Black) measured MVPA (waist-worn ActiGraph GT3X) and SED (thigh-mounted activPAL) as well as self-reported depressive symptoms and mood disturbance in each trimester. Associations of group-based trajectories of MVPA and SED with depressive symptoms and mood disturbance were analyzed using regression analyses, both overall and by trimester. Results: Overall, the medium versus low trajectory of MVPA was associated with lower levels of depressive symptoms (B = -1.82, 95% confidence interval [CI] -2.97 to -0.68). In the second trimester, women in either the medium or high MVPA trajectories had lower levels of depressive symptoms compared with women in the low MVPA trajectory (B = -8.73, 95% CI -15.74 to -1.71; and B = -2.18, 95% CI -3.80 to -0.56). SED trajectories were not associated with depressive symptoms. Higher trajectories of MVPA and lower trajectories of SED were associated with lower total mood disturbance, with significant associations in the second trimester for MVPA and the first and second trimesters for SED. Higher MVPA trajectories were associated with higher tension, fatigue, and confusion subscales, while higher SED trajectories were associated with higher anger and fatigue and lower esteem and vigor subscales. Conclusions: MVPA and SED levels appear to affect mental health during pregnancy, although larger prospective studies are warranted. Clinical Trail Registration Number: NCT03084302.
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Depressão , Exercício Físico , Comportamento Sedentário , Humanos , Feminino , Gravidez , Exercício Físico/psicologia , Adulto , Depressão/psicologia , Depressão/epidemiologia , Estudos de Coortes , Saúde Mental , Complicações na Gravidez/psicologia , Trimestres da Gravidez/psicologia , AutorrelatoRESUMO
Polylactic acid (PLA) and bioplastics alike have a designed degradability to avoid the environmental buildup that petroplastics have created. Yet, this designed biotic-degradation has typically been characterized in ideal conditions. This study seeks to relate the abiotic to the biotic degradation of PLA to accurately represent the degradation pathways bioplastics will encounter, supposing their improper disposal in the environment. Enzymatic hydrolysis was used to study the biodegradation of PLA with varying stages of photoaging. Utilizing a fluorescent tag to follow enzyme hydrolysis, it was determined that increasing the amount of irradiation yielded greater amounts of total enzymatic hydrolysis by proteinase K after 8 h of enzyme incubation. While photoaging of the polymers causes minimal changes in chemistry and increasing amounts of crystallinity, the trends in biotic degradation appear to primarily be driven by photoinduced reduction in molecular weight. The relationship between photoaging and enzyme hydrolysis appears to be independent of enzyme type, though commercial product degradation may be impacted by the presence of additives. Overall, this work reveals the importance of characterizing biodegradation with relevant samples that ultimately can inform optimization of production and disposal.
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While nanoparticles occur naturally in the environment and have been intentionally used for centuries, the production and use of engineered nanoparticles has seen a recent spike, which makes environmental release almost certain. Therefore, recent efforts to characterize the toxicity of engineered nanoparticles have focused on the environmental implications, including exploration of toxicity to organisms from wide-ranging parts of the ecosystem food webs. Herein, we summarize the current understanding of toxicity of engineered nanoparticles to representatives of various trophic levels, including bacteria, plants, and multicellular aquatic/terrestrial organisms, to highlight important challenges within the field of econanotoxicity, challenges that analytical chemists are expertly poised to address.
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Poluição Ambiental/efeitos adversos , Nanopartículas/toxicidade , Nanotecnologia/tendências , Animais , Monitoramento Ambiental/métodos , Poluição Ambiental/prevenção & controle , Humanos , Nanopartículas/química , Nanotecnologia/métodosRESUMO
Understanding of nanoparticle impacts on critical bacteria functions allows us to gain a mechanistic understanding of toxicity and guides us toward design rules for creating safe nanomaterials. Herein, biofilm formation, a general bacteria function, and riboflavin secretion, a species-specific function, were monitored in Shewanella oneidensis, a metal reducing bacterium, following exposure to a variety of TiO2 nanoparticle types (synthesized, Aeroxide P25, and T-Eco). Transmission electron microscopy (TEM) images show that dosed nanoparticles are in close proximity to the bacteria, but they are not internalized. Using quartz crystal microbalance (QCM), it was revealed that S. oneidensis biofilm formation is slowed in the presence of nanoparticles. Though S. oneidensis grows more slowly in the presence of TiO2 nanoparticles, riboflavin secretion, a function related to the S. oneidensis metal reducing capacity, was increased significantly in a nanoparticle dose-dependent manner. Both changes in biofilm formation and riboflavin secretion are supported by changes in gene expression in nanoparticle-exposed S. oneidensis. This broad study of bacterial nanotoxicity, including use of sensitive analytical tools for functional assessments of biofilm formation, riboflavin secretion, and gene expression, has implications for total ecosystem health as the use of engineered nanoparticles grows.
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Biofilmes/crescimento & desenvolvimento , Flavinas/metabolismo , Nanopartículas/metabolismo , Shewanella/fisiologia , Titânio/metabolismo , Biofilmes/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Flavinas/antagonistas & inibidores , Nanopartículas/toxicidade , Shewanella/efeitos dos fármacos , Titânio/toxicidadeRESUMO
BACKGROUND: Cardiovascular disease (CVD) progression occurs across the lifespan. However, available measures of CVD risk in young children are limited. Carotid-femoral pulse wave velocity (cfPWV) is a gold-standard, noninvasive measure of CVD risk that has been studied in children ages 6-18 years. Yet, cfPWV has been measured to a lesser extent in younger children, a population whose temperament or attention span may pose unique challenges. Brachial-femoral PWV (bfPWV) may be feasible, more acceptable, and could provide similar CVD risk assessment to cfPWV in younger children. This study aimed to determine the feasibility of bfPWV measurement in children ages 2-4 years including assessment of comparability of bfPWV to cfPWV normative data. METHODS: In 10 children (mean 2.9 ± 0.5 years), oscillometric cuffs were placed on the upper thigh and upper arm. Following a 5-min rest, cuffs were inflated to a subdiastolic pressure three times, and waveforms were captured. Procedures were repeated after a 15-min rest. Measured values were compared to age-predicted cfPWV extrapolated from published normative data in children 6-18 years of age. RESULTS: We successfully obtained at least one acceptable quality bfPWV scan in all participants. Among the subset with a repeated measurement ( n = 5), mean (SD) difference between measurements was 0.013 (0.28) m/s. Mean bfPWV was slightly higher than age-predicted cfPWV (observed: 4.55 m/s; predicted: 3.99 m/s; P = 0.012) with larger residuals among younger children and those not reclined in a chair during measurement. CONCLUSION: bfPWV appears to be feasible tool for noninvasive CVD risk assessment in children ages 2-4 years.
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Doenças Cardiovasculares , Rigidez Vascular , Humanos , Pré-Escolar , Criança , Adolescente , Estudos de Viabilidade , Pressão Sanguínea , Análise de Onda de Pulso/métodos , Artérias Carótidas/diagnóstico por imagem , Artéria Femoral , Doenças Cardiovasculares/epidemiologia , Fatores de RiscoRESUMO
Plastic pollution is a major threat facing our environment. To understand the full effects, we must first characterize how plastics break down in environmental systems. Heretofore, there has been little work examining how exposure to sewage sludge facilitates the degradation of plastics, particularly of plastics that have been previously weathered. Herein, we characterize how the crystallinity, surface chemistry, and morphology of polylactic acid (PLA) and polyethylene (PE) films change due to sludge exposure. In this work, sludge-induced changes in carbonyl index were found to depend on the level of prior exposure to ultraviolet (UV) irradiation. The carbonyl indices of un-irradiated films increased while those of UV-aged films decreased after 35 days of sludge exposure. In addition, the carbonoxygen and hydroxyl bond indices of PE films increased with sludge exposure, suggesting the surface oxidation of PE. As for PLA, crystallinity was found to increase with sludge exposure, consistent with a chain scission mechanism. This work will help to predict the behavior of plastic films after transfer from wastewater to sewage sludge.