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Objetivo: analisar a incidência e os fatores relacionados à obstrução de cateter intravenoso periférico em adultos hospitalizados. Método: uma coorte prospectiva, realizada a partir da observação de 203 cateteres, entre fevereiro de 2019 e maio de 2020, em hospital público e de ensino brasileiro. Foram consideradas variáveis clínicas e do cateter. Os dados foram analisados descritivamente e por estatística inferencial. Resultados: o tempo de permanência variou entre um a 15 dias e a obstrução ocorreu em 7,5% das observações. Houve aumento do risco de obstrução em relação ao sexo (RR=0,49 / p=0,186), à idade (RR=1,20/ p=0,732), aos cateteres de maior calibre (RR=0,53/ p=0,250), à inserção no dorso da mão até antebraço (RR=2,33/ p=0,114) e ao tempo do cateter in situ (RR=033/ p=0,433). Conclusão: O cuidado diário e observação do cateter intravenoso periférico são importantes para minimizar o surgimento de complicações locais e sistêmicas e manter a patência do dispositivo.
Objective: to analyze the incidence and factors related to peripheral intravenous catheter obstruction in hospitalized adults. Method: a prospective cohort, based on the observation of 203 catheters, between February 2019 and May 2020, in a Brazilian public teaching hospital. Clinical and catheter variables were taken into account. The data was analyzed descriptively and using inferential statistics. Results: the length of stay ranged from one to 15 days and obstruction occurred in 7.5% of the observations. There was an increased obstruction risk in relation to gender (RR=0.49 / p=0.186), age (RR=1.20/ p=0.732), larger catheters (RR=0.53/ p=0.250), insertion in the back of the hand up to the forearm (RR=2.33/ p=0.114) and the time length the catheter was in situ (RR=033/ p=0.433). Conclusion: Daily care and observation of the peripheral intravenous catheter is important to minimize the appearance of local and systemic complications and maintain the patency of the device.
Objetivo: analizar la incidencia y los factores relacionados con la obstrucción del catéter intravenoso periférico en adultos hospitalizados. Método: cohorte prospectiva, realizada mediante la observación de 203 catéteres, entre febrero de 2019 y mayo de 2020, en un hospital escuela público brasileño. Se consideraron variables clínicas y del catéter. Los datos se analizaron de forma descriptiva y mediante estadística inferencial. Resultados: el tiempo de permanencia varió entre uno y 15 días y la obstrucción ocurrió en el 7,5% de las observaciones. Hubo mayor riesgo de obstrucción en relación con el sexo (RR=0,49 / p=0,186), la edad (RR=1,20 / p=0,732), los catéteres de mayor calibre (RR=0,53 / p= 0,250), la inserción en el dorso de la mano hasta el antebrazo (RR=2,33/ p=0,114) y el tiempo del catéter in situ (RR=033/ p=0,433). Conclusión: el cuidado diario y la observación del catéter intravenoso periférico son importantes para minimizar la aparición de complicaciones locales y sistémicas y mantener la permeabilidad del dispositivo.
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Understanding the relationship between a dam's size and its ecological effects is important for prioritization of river restoration efforts based on dam removal. Although much is known about the effects of large storage dams, this information may not be applicable to small dams, which represent the vast majority of dams being considered for removal. To better understand how dam effects vary with size, we conducted a multidisciplinary study of the downstream effect of dams on a range of ecological characteristics including geomorphology, water chemistry, periphyton, riparian vegetation, benthic macroinvertebrates, and fish. We related dam size variables to the downstream-upstream fractional difference in measured ecological characteristics for 16 dams in the mid-Atlantic region ranging from 0.9 to 57 m high, with hydraulic residence times (HRTs) ranging from 30 min to 1.5 years. For a range of physical attributes, larger dams had larger effects. For example, the water surface width below dams was greater below large dams. By contrast, there was no effect of dam size on sediment grain size, though the fraction of fine-grained bed material was lower below dams independently of dam size. Larger dams tended to reduce water quality more, with decreased downstream dissolved oxygen and increased temperature. Larger dams decreased inorganic nutrients (N, P, Si), but increased particulate nutrients (N, P) in downstream reaches. Aquatic organisms tended to have greater dissimilarity in species composition below larger dams (for fish and periphyton), lower taxonomic diversity (for macroinvertebrates), and greater pollution tolerance (for periphyton and macroinvertebrates). Plants responded differently below large and small dams, with fewer invasive species below large dams, but more below small dams. Overall, these results demonstrate that larger dams have much greater impact on the ecosystem components we measured, and hence their removal has the greatest potential for restoring river ecosystems.
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Ecossistema , Invertebrados , Rios , Animais , Invertebrados/fisiologia , Peixes/fisiologia , Conservação dos Recursos Naturais , Movimentos da Água , Monitoramento AmbientalRESUMO
While atmospheric microplastics are known to be transported over long distances, their residence times and transport processes lack clarity. This study utilized natural radionuclides 7Be, 210Pb, and 210Po to explore the transport of atmospheric microplastics in Tianjin, a coastal city in Northern China. Microplastic concentrations ranged from 0.03 to 0.13 particles m-3 over the course of a year. The proportion of microplastic fragments in winter was significantly higher than that in other seasons, with median microplastic sizes in autumn and winter being larger than those in spring and summer. The atmospheric microplastic surface was rough, exhibiting irregular pores and multiple depressions and cracks. Microplastics experienced vertical mixing with the upper atmosphere in April and August and were influenced by rainfall in July. The residence time of atmospheric particles ranged from 9.47 to 22.85 days throughout the year, with an average of 14.41 days. The peak residence time of atmospheric particulates in November may be correlated with increased 210Po levels from coal consumption. Their prolonged atmospheric presence and rough surface allow microplastics to act as carriers for various chemical pollutants, underscoring the complexity and potential risks associated with their presence in the atmosphere.
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Atmosfera , Microplásticos , Microplásticos/análise , Atmosfera/química , China , Radioisótopos de Chumbo/análise , Radioisótopos/análise , Monitoramento Ambiental , Estações do Ano , Berílio/análise , Polônio/análiseRESUMO
Epidemic models of susceptibles, exposed, infected, recovered and deceased (SΕIRD) presume homogeneity, constant rates and fixed, bilinear structure. They produce short-range, single-peak responses, hardly attained under restrictive measures. Tuned via uncertain I,R,D data, they cannot faithfully represent long-range evolution. A robust epidemic model is presented that relates infected with the entry rate to health care units (HCUs) via population averages. Model uncertainty is circumvented by not presuming any specific model structure, or constant rates. The model is tuned via data of low uncertainty, by direct monitoring: (a) of entries to HCUs (accurately known, in contrast to delayed and non-reliable I,R,D data) and (b) of scaled model parameters, representing population averages. The model encompasses random propagation of infections, delayed, randomly distributed entries to HCUs and varying exodus of non-hospitalized, as disease severity subdues. It closely follows multi-pattern growth of epidemics with possible recurrency, viral strains and mutations, varying environmental conditions, immunity levels, control measures and efficacy thereof, including vaccination. The results enable real-time identification of infected and infection rate. They allow design of resilient, cost-effective policy in real time, targeting directly the key variable to be controlled (entries to HCUs) below current HCU capacity. As demonstrated in ex post case studies, the policy can lead to lower overall cost of epidemics, by balancing the trade-off between the social cost of infected and the economic contraction associated with social distancing and mobility restriction measures.
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OBJECTIVE: Oral health is often overlooked in ageing health issues, despite its impact on overall health and quality of life. Older Australians, especially those in rural and remote areas, face difficulties accessing oral health services. The aim of the study was to investigate the factors that contribute to financial barriers to accessing dental services among the ageing population in Australia in relation to their residential location. METHOD: The study included a weighted sample of Australian adults aged 65 years and over from a population-based survey called the National Study of Adult Oral Health (NSAOH) conducted in 2017-18. Descriptive analysis was conducted and generated cross-tabulation tables to investigate the distributions of the outcome, exposure and covariates, including Sex, Education level (the highest level of education), Equivalised household income, Dental insurance, Concession card ownership, Difficulty paying a dental bill and last dental visit. Blinder-Oaxaca decomposition counterfactual analysis was used to explore the potential impact of a person's residence on their financial difficulty accessing dental services. RESULTS: The findings showed that 26.2% (95% CI: 24.3-29.3) of major city residents and 30.1% (95% CI: 26.9-33.3) of rural residents avoided or delayed dental visits due to cost. The decomposition analysis indicated that 53.8% of the disparities in the prevalence of avoided or delayed dental visits due to cost were explained by the selected variables, while 46.2% remained unexplained. The explanatory variable with the largest contribution was difficulty paying a $200 dental bill, accounting for 62.4% of the differences, followed by dental insurance, last dental visit and equivalised household income, which explained 42.1%, 20.8% and 14.9% of the differences, respectively. CONCLUSION: Regional/remote populations experience more financial barriers to accessing dental care than major city populations and the identified factors explain a significant proportion of these disparities. Based on the study findings, recommendations include expanding public dental service coverage, evaluating concession card mechanisms and advocating for regular dental visits to mitigate disparities in dental care access.
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Lithium tantalate (LiTaO3) perovskite finds wide use in pyroelectric detectors, optical waveguides and piezoelectric transducers, stemming from its good mechanical and chemical stability and optical transparency. Herein, we present a method for synthesis of LiTaO3 nanoparticles using a scalable Flame Spray Pyrolysis (FSP) technology, that allows the formation of LiTaO3 nanomaterials in a single step. Raman, XRD and TEM studies allow for comprehension of the formation mechanism of the LiTaO3 nanophases, with particular emphasis on the penetration of Li atoms into the Ta-oxide lattice. We show that, control of the High-Temperature Particle Residence Time (HTPRT) in the FSP flame, is the key-parameter that allows successful penetration of the -otherwise amorphous- Li phase into the Ta2O5 nanophase. In this way, via control of the HTPRT in the FSP process, we synthesized a series of nanostructured LiTaO3 particles of varying phase composition from {amorphous Li/Ta2O5/LiTaO3} to {pure LiTaO3, 15-25 nm}. Finally, the photophysical activity of the FSP-made LiTaO3 was validated for photocatalytic H2 production from H2O. These data are discussed in conjunction with the role of the phase composition of the LiTaO3 nanoparticles. More generally, the present work allows a better understanding of the mechanism of ABO3 perovskite formation that requires the incorporation of two cations, A and B, into the nanolattice.
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In river networks, reservoirs are hotspots for nutrient transformations, providing multiple pathways for nitrogen processing. One of the less measured pathways is nitrogen deposition. Here, we investigated the decadal relationship between water residence time and nitrogen deposition using sediment cores from eight mainstem reservoirs within a river system containing two contrasting watersheds. One watershed was significantly urbanized with regulated flow and the other watershed was unregulated with extensive rural land use. We explored the relationship of sediment nitrogen concentrations across a range of residence times, land uses, and other parameters throughout this linked river-reservoir system. Results show that average annual residence time had the strongest relationship to nitrogen deposition when compared to reservoir volume, mean depth, surface area, outflow, and land use. Pigment analysis revealed that residence time influences nitrogen by allowing for longer periods of algal uptake, followed by deposition in particulate organic form. Supporting this mechanism, sedimentary C:N, with low values representing greater algal influence, expressed a strong and negative relationship with average annual residence time, as well as a positive relationship between residence time and photosynthetic pigments diagnostic of cyanobacteria, diatoms, and a combination of green algae+cyanobacteria. Furthermore, we investigated how drought conditions could alter residence times and intensify nitrogen cycling through primary productivity in reservoirs. Drought increased residence time by 45-60 %. This increase was estimated to raise sediment nitrogen concentrations by roughly 2.5-4 %.
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The continuous permafrost in the valleys of Svalbard is dotted by pingos, which are small hills formed by the near surface freezing of ascending groundwater. In this study, we used 3H and Ra isotopes to inquire into the sub-surface residence time of groundwater discharging at these pingos. While its low 3H suggests that the pingo-associated groundwater is basically not modern (i.e. older than 60 years), Ra isotopes imply that most water has an underground residence time of several hundred years. This is deduced from the lower than equilibrium ratios (activity ratios<21.7) of the long-lived to short-lived 226Ra/223Ra. Since the freezing age of the main body of permafrost in this area is >4000 years, the presence of younger water at depth suggests that the aquifer has been recharged after permafrost formation, which could take place via faults or through the non-frozen base of wet glaciers. This active hydrology suggests that permafrost in the valleys of Svalbard was at least locally discontinuous during the Late Holocene, with likely further implications to the release of greenhouse gases during the pre-industrial period.
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OBJECTIVES: Family caregivers of older adults with severe dementia often experience anticipatory grief. We aimed to investigate the temporal association of caregiving stressors (older adults' behavioral symptoms, and caregiver-older adult co-residence and emotional closeness) and caregivers' anticipatory grief, and its mediation by positive and negative caregiving experiences. DESIGN: Prospective cohort. SETTING: Singapore. PARTICIPANTS: About 169 family caregivers of older adults with severe dementia were surveyed every 4 months for 4 years (up to 13 surveys). MEASUREMENTS: We measured anticipatory grief using the Marwit Meuser Caregiver Grief Inventory-Short Form, negative caregiving experiences using the Caregiver Reaction Assessment scale, positive caregiving experiences using Gain in Alzheimer Care Instrument and behavioral symptoms using the Cohen-Mansfield Agitation Inventory. We implemented a cross-lagged panel model to test mediation, a form of longitudinal path analysis. RESULTS: About 35% of the caregivers reported high anticipatory grief at least once during the study period. Older adults' behavioral symptoms had a significant direct effect (Standardized coefficient [95% confidence interval]: 0.12 [0.04, 0.21]) on caregivers' anticipatory grief. Negative experiences mediated the significant indirect effect of older adults' behavioral symptoms (0.16 [0.06, 0.25]) and coresidence (0.16 [0.07, 0.25]) on caregivers' anticipatory grief. Positive caregiving experiences did not mediate any path. CONCLUSIONS: Findings indicate a temporal association between caregiving stressors and anticipatory grief, mediated by negative caregiving experiences. Routine screening for anticipatory grief, and interventions to address caregiver stressors and negative caregiving experiences may alleviate caregivers' grief.
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OBJECTIVE: This study is part of a programmatic investigation of rural disparities in cigarette smoking examining disparities in smoking prevalence and for the first-time quit ratios among adult women of reproductive age (18-44 years), a highly vulnerable population due to risk for multigenerational adverse effects. METHODS: Data came from 18 years (2002-2019) of the U.S. National Survey on Drug Use and Health (NSDUH) among women (n = 280,626) categorized by rural-urban residence, pregnancy status, using weighted logistic regression models testing time trends and controlling for well-established sociodemographic predictors of smoking (race/ethnicity, education, income). Concerns regarding changes in survey methods used before 2002 and after 2019 precluded inclusion of earlier and more recent survey years in the present study. RESULTS: Overall smoking prevalence across years was greater in rural than urban residents (adjusted odds ratio [AOR] = 1.11; 95%CI, 1.07-1.15; P < .001) including those not-pregnant (AOR = 1.10; 1.07-1.14; P < .001) and pregnant (AOR = 1.29; 1.09-1.52; P < .001). Overall quit ratios across years were lower in rural than urban residents (AOR = 0.93; 0.87-0.99; P < .001) including those not-pregnant (AOR = 0.93; 0.88-1.00, P = .035) and pregnant (AOR = 0.78; 0.62-0.99; P = .039). Interactions of rural versus urban residence with study years for prevalence and quit ratios overall and by pregnancy status are detailed in the main text. CONCLUSIONS: These results support a longstanding and robust rural disparity in smoking prevalence among women of reproductive age including those currently pregnant and provides novel evidence that differences in smoking cessation contribute to this disparity further underscoring a need for greater access to evidence-based tobacco control and regulatory interventions in rural regions.
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Tuberculosis remains a leading cause of death from a single infection worldwide. Drug resistance to existing and even new antimycobacterials calls for research into novel targets and unexplored mechanisms of action. Recently we reported on the development of tight-binding inhibitors of Mycobacterium tuberculosis (Mtb) lipoamide dehydrogenase (Lpd), which selectively inhibit the bacterial but not the human enzyme based on a differential modality of inhibitor interaction with these targets. Here we report on the striking improvement in inhibitor residence time on the Mtb enzyme associated with scaffold progression from an indazole to 2-cyanoindole. Cryo-EM of Lpd with the bound 2-cyanoindole inhibitor 19 confirmed displacement of the buried water molecule deep in the binding channel with a cyano group. The ensuing hours-long improvement in on-target residence time is associated with enhanced antibacterial activity in axenic culture and in primary mouse macrophages. Resistance to 2-cyanoindole inhibitors involves mutations within the inhibitor binding site that have little effect on inhibitor affinity but change the modality of inhibitor-target interaction, resulting in fast dissociation from Lpd. These findings underscore that on-target residence time is a major determinant of antibacterial activity and in vivo efficacy.
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G protein-coupled receptors (GPCRs) are lipid-regulated transmembrane proteins that play a central role in cell signaling and pharmacology. Although the role of membrane lipids in GPCR function is well established, the underlying GPCR-lipid interactions have not been thermodynamically characterized due to the complexity of these interactions. In this work, we estimate the energetics and dynamics of lipid association from coarse-grain simulations of the serotonin1A receptor embedded in a complex membrane. We show that lipids bind to the receptor with varying energetics of 1-4 kT, and timescales of 1-10 µs. The most favorable energetics and longest residence times are observed for cholesterol, glycosphingolipid GM1, phosphatidylethanolamine (PE) and phosphatidylserine (PS) lipids. Multi-exponential fitting of the contact probability suggests distinct dynamic regimes, corresponding to ps, ns and µs timescales, that we correlate with the annular, intermediate and non-annular lipid sites. The timescales of lipid binding correspond to high barrier heights, despite their relatively weaker energetics. Our results highlight that GPCR-lipid interactions are driven by both thermodynamic interactions and the dynamical features of lipid binding.
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Receptor 5-HT1A de Serotonina , Termodinâmica , Receptor 5-HT1A de Serotonina/metabolismo , Receptor 5-HT1A de Serotonina/química , Simulação de Dinâmica Molecular , Lipídeos de Membrana/metabolismo , Lipídeos de Membrana/química , Fosfatidiletanolaminas/química , Fosfatidiletanolaminas/metabolismo , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Colesterol/metabolismo , Colesterol/químicaRESUMO
INTRODUCTION: Some evidence suggests that cannabis may be a safer substitute for other drugs. Historically, sober living houses (SLHs) have been abstinence-based environments designed for individuals in recovery to live with others in recovery. However, the evolving legal landscape around cannabis use has left SLH operators and managers in a difficult position regarding policies related to cannabis use among residents. The primary aim of this study was to examine how cannabis use relates to alcohol use, other drug use, and related problems among SLH residents. METHODS: Baseline (N = 557), 6-month (n = 462), and 12-month (n = 457) data came from SLH residents living in 48 houses in Los Angeles, CA from 2018 to 2021. Longitudinal generalized estimating equation models tested associations between any past six-month cannabis use and alcohol and non-cannabis drug outcomes: any use, number of days of use, and any alcohol- or drug-related problems. Final models adjusted for baseline age, sex, race-and-ethnicity, inpatient substance use treatment, and alcohol/drug use days, and time-varying 12-step attendance and percent of social network using drugs/alcohol heavily. RESULTS: At baseline, 107 (19.2 %) residents reported cannabis use in the past six months. At 12 months, 80 (17.5 %) residents reported cannabis use in the past six months. Across all timepoints, any vs. no past six-month cannabis use was related to significantly (P < 0.05) higher odds of past-month alcohol use (OR = 3.85, 95 % CI: 2.65, 5.59); more drinking days in the past six months (IRR = 1.76, 95 % CI: 1.40, 2.21); higher odds of alcohol problems (OR = 2.74, 95 % CI: 1.99, 3.76); higher odds of past-month drug use (OR = 10.41, 95 % CI: 6.37, 17.00); more drug use days in the past six months (IRR = 1.86, 95 % CI: 1.40, 2.49); and higher odds of drug problems (OR = 14.99, 95 % CI: 9.91, 22.68). CONCLUSIONS: During each assessment period, almost one-fifth of individuals residing in sample of California sober living houses report using cannabis in the past six months. Cannabis does not appear to work as a substitute for alcohol or other drugs in this population because cannabis use is related to increased risk of alcohol and other drug use and problems. SLH managers and operators should consider potential harm that could result from house policies that fail to address cannabis use.
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Transtornos Relacionados ao Uso de Substâncias , Humanos , Feminino , Masculino , Adulto , Estudos Longitudinais , Pessoa de Meia-Idade , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Consumo de Bebidas Alcoólicas/epidemiologia , Consumo de Bebidas Alcoólicas/legislação & jurisprudência , Los Angeles/epidemiologia , Uso da Maconha/legislação & jurisprudência , Uso da Maconha/epidemiologia , California/epidemiologia , Casas para Recuperação , Adulto Jovem , Alcoolismo/epidemiologiaRESUMO
Introduction: The present research investigates the activity of Kolberi in the border villages of western and northwestern Iran, specifically in the Kurdish area of Nosud in Kermanshah province. Kolberi, a form of labor in these regions, subjects individuals to severe risks, including painful death or lifelong physical injuries, bringing considerable suffering and hardships to the Kolbers and their families. This study explores the narratives of Kolbers' mothers regarding their children's Kolberi experiences through Pierre Bourdieu's theoretical framework of social suffering. Methods: This qualitative study employs interpretive phenomenology to examine the lived experiences of mothers in the Nosud border area. Twenty-two Kolbers' mothers were selected using purposive sampling. Data collection was conducted through semi-structured interviews and participant observation, continuing until theoretical saturation was achieved. Results: Content analysis of the interviews revealed eight basic themes: (1) occurrence and aggravation of physical and mental complications, (2) reproduction of poverty and misery, (3) marginalization of the field of education in border areas, (4) emergence of structural determinism alongside environmental determinism, (5) weakening of the social status of Kolbers, (6) Kolber and bare life, (7) structural dehumanization of Kolber's position, and (8) unique experiences of mothers regarding Kolberi. Discussion: The findings highlight the unique and often neglected experiences of mothers related to Kolberi, emphasizing the economic struggles in Iran's border areas. These experiences unveil hidden aspects of Kolberi, suggesting potential avenues for further research and contributing to the revitalization of activism among Kolbers' mothers in border regions. The study underscores the importance of addressing the socio-economic conditions that perpetuate Kolberi and its associated sufferings.
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The dimeric kinesin-8 motors have the biological function of depolymerizing microtubules (MTs) from the plus end. However, the molecular mechanism of the depolymerization promoted by the kinesin-8 motors is still undetermined. Here, a model is proposed for the MT depolymerization by the kinesin-8 motors. Based on the model, the dynamics of depolymerization in the presence of the single motor at the MT plus end under no load and under load on the motor is studied theoretically. The dynamics of depolymerization in the presence of multiple motors at the MT plus end is also analyzed. The theoretical results explain well the available experimental data. The studies can also be applicable to other families of kinesin motors such as kinesin-13 mitotic centromere-associated kinesin motors that have the ability to depolymerize MTs.
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Cinesinas , Microtúbulos , Polimerização , Cinesinas/metabolismo , Cinesinas/química , Microtúbulos/metabolismo , Humanos , AnimaisRESUMO
BACKGROUND: This study investigated the association between living arrangements and healthrelated quality of life (HRQoL) in older people. METHODS: A secondary analysis was conducted of 6,153 participants (aged ≥60 years) from the seventh Korean National Health and Nutrition Examination Survey (2016 to 2018). HRQoL was measured using the 3-level version of the EuroQol 5-dimensional questionnaire. The chi-square test, t-test, and multiple regression were used, applying sampling weights for the analysis. RESULTS: The proportion of respondents living alone was 18.0%, with a higher prevalence among women and older age groups (p<0.001). The overall HRQoL was lower in groups living alone than in groups living with others (p<0.001). Older people living alone showed higher impairments in all dimensions of the 3-level version of the European Quality of Life 5-Dimensional Questionnaire (EQ-5D-3L) than those living with others, including mobility (p<0.001), self-care (p<0.001), usual activities (p<0.001), pain/discomfort (p<0.001), and depression/anxiety (p<0.001). Problems with mobility were most prevalent (42.8%), followed by pain/ discomfort (41.9%) in respondents living alone. Living alone was significantly associated with a lower HRQoL index score (b=-0.048, p<0.001) after adjusting for age, gender, education, exercise, perceived stress, and perceived health status. CONCLUSION: Living alone was negatively associated with HRQoL. Based on this study, future care planning for older people should consider their living arrangements. The need to strengthen and expand care programs targeting those living alone should also be addressed.
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The ecological impact of non-native species arises from their establishment in local assemblages. However, the rates of non-native spread in new regions and their determinants have not been comprehensively studied. Here, we combined global databases documenting the occurrence of non-native species and residence of non-native birds, mammals, and vascular plants at regional and local scales to describe how the likelihood of non-native occurrence and their proportion in local assemblages relate with their residence time and levels of human usage in different ecosystems. Our findings reveal that local non-native occurrence generally increases with residence time. Colonization is most rapid in croplands and urban areas, while it is slower and variable in natural or semi-natural ecosystems. Notably, non-native occurrence continues to rise even 200 years after introduction, especially for birds and vascular plants, and in other land-use types rather than croplands and urban areas. The impact of residence time on non-native proportions is significant only for mammals. We conclude that the continental exchange of biotas requires considerable time for effects to manifest at the local scale across taxa and land-use types. The unpredictability of future impacts, implied by the slow spread of non-native species, strengthens the call for stronger regulations on the exchange of non-native species to reduce the long-lasting invasion debt looming on ecosystems' future.
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Aves , Espécies Introduzidas , Mamíferos , Animais , Plantas , Ecossistema , Biodiversidade , Conservação dos Recursos NaturaisRESUMO
Nowadays, the utilization of biogas for energy generation is hindered by the declining production costs of solar and wind power. A shift towards the valorization of biogas into ectoine, a highly valuable bioproduct priced at 1000 ⸱kg-1, offers a novel approach to fostering a more competitive biogas market while contributing to carbon neutrality. This study evaluated the optimization of CH4 gas-liquid mass transfer in 10 L bubble column bioreactors for CH4 conversion into ectoine and hydroxyectoine using a mixed methanotrophic culture. The influence of the empty bed residence time (EBRTs of 27, 54, and 104 min) at different membrane diffuser pore sizes (0.3 and 0.6 mm) was investigated. Despite achieving CH4 elimination capacities (CH4-ECs) of 10-12 g⸱m-3⸱h-1, an EBRT of 104 min mediated CH4 limitation within the cultivation broth, resulting in a negligible biomass growth. Reducing the EBRT to 54 min entailed CH4-ECs of 21-24 g⸱m-3⸱h-1, concomitant to a significant increase in biomass growth (up to 0.17 g⸱L⸱d-1) and reaching maximum ectoine and hydroxyectoine accumulation of 79 and 13 mg⸱gVSS-1, respectively. Conversely, process operation at an EBRT of 27 min lead to microbial inhibition, resulting in a reduced biomass growth of 0.09 g⸱L⸱d-1 and an ectoine content of 47 mg⸱gVSS-1. While the influence of diffuser pore size was less pronounced compared to EBRT, the optimal process performance was observed with a diffuser pore size of 0.6 mm.
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Biocombustíveis , Reatores Biológicos , Metano , Metano/metabolismo , Diamino Aminoácidos/metabolismo , BiomassaRESUMO
Though their small size, ponds play a disproportionately crucial role in eliminating nitrogen (N) transporting to downstream freshwaters. As significant water infrastructures, ponds are non-sustainable due to loss of storage capacity resulting from sedimentation. However, the effects of pond sedimentation on N removal is widely neglected in landscape N processing. The NUFER (Nutrient flows in Food chains, Environment and Resources use) model was employed to estimate N runoff from 1960 to 2018. We reconstructed the dynamic of number and storing capacity of about 14 million ponds due to construction and sedimentation from 1960 to 2018, projecting these trends into the year 2060. Our approach incorporated first-order kinetic reactions, including water residence time (HRT), to estimate N removal of ponds, utilizing data 6 monitoring ponds and 81 ponds from literature studies. Our analysis reveals a fourteen-fold increase in N runoff over the past six decades, rising from 0.8 Mt N in 1960 to 11.4 Mt N in 2018. Due to the initial rapid expansion of ponds, N removal by ponds increased from 6.4 % in 1960 to 13.6 % in 1990. Sedimentation is prevalent in ponds, particularly in small ponds with a sedimentation accumulation rate of 2.96 cm yr-1. Pond sedimentation, which reduces HRT, resulted in a decrease in pond N removal percentage to 11.2 % in 2018 and a projected 7.4 % by the year 2060, assuming similar sediment accumulation rates persist in the future. Overall, our findings underscore the non-negligible role of ponds as landscape nodes in N cycling. Urgent mitigation measures are needed to extend the lifetime of existing ponds and sustain their critical role in water quality management.