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1.
Proc Natl Acad Sci U S A ; 119(29): e2120553119, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35858352

RESUMO

The physics of mutual interaction of phonon quasiparticles with electronic spin degrees of freedom, leading to unusual transport phenomena of spin and heat, has been a subject of continuing interests for decades. Despite its pivotal role in transport processes, the effect of spin-phonon coupling on the phonon system, especially acoustic phonon properties, has so far been elusive. By means of inelastic neutron scattering and first-principles calculations, anomalous scattering spectral intensity from acoustic phonons was identified in the exemplary collinear antiferromagnetic nickel (II) oxide, unveiling strong spin-lattice correlations that renormalize the polarization of acoustic phonon. In particular, a clear magnetic scattering signature of the measured neutron scattering intensity from acoustic phonons is demonstrated by its momentum transfer and temperature dependences. The anomalous scattering intensity is successfully modeled with a modified magneto-vibrational scattering cross-section, suggesting the presence of spin precession driven by phonon. The renormalization of phonon eigenvector is indicated by the observed "geometry-forbidden" neutron scattering intensity from transverse acoustic phonon. Importantly, the eigenvector renormalization cannot be explained by magnetostriction but instead, it could result from the coupling between phonon and local magnetization of ions.

2.
Bull Math Biol ; 83(7): 73, 2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-34008062

RESUMO

A central need in the field of astrobiology is generalized perspectives on life that make it possible to differentiate abiotic and biotic chemical systems McKay (2008). A key component of many past and future astrobiological measurements is the elemental ratio of various samples. Classic work on Earth's oceans has shown that life displays a striking regularity in the ratio of elements as originally characterized by Redfield (Redfield 1958; Geider and La Roche 2002; Eighty years of Redfield 2014). The body of work since the original observations has connected this ratio with basic ecological dynamics and cell physiology, while also documenting the range of elemental ratios found in a variety of environments. Several key questions remain in considering how to best apply this knowledge to astrobiological contexts: How can the observed variation of the elemental ratios be more formally systematized using basic biological physiology and ecological or environmental dynamics? How can these elemental ratios be generalized beyond the life that we have observed on our own planet? Here, we expand recently developed generalized physiological models (Kempes et al. 2012, 2016, 2017, 2019) to create a simple framework for predicting the variation of elemental ratios found in various environments. We then discuss further generalizing the physiology for astrobiological applications. Much of our theoretical treatment is designed for in situ measurements applicable to future planetary missions. We imagine scenarios where three measurements can be made-particle/cell sizes, particle/cell stoichiometry, and fluid or environmental stoichiometry-and develop our theory in connection with these often deployed measurements.


Assuntos
Exobiologia , Conceitos Matemáticos
3.
Conserv Biol ; 33(1): 9-21, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30055022

RESUMO

Wildlife hunting is essential to livelihoods and food security in many parts of the world, yet present rates of extraction may threaten ecosystems and human communities. Thus, governing sustainable wildlife use is a major social dilemma and conservation challenge. Commons scholarship is well positioned to contribute theoretical insights and analytic tools to better understand the interface of social and ecological dimensions of wildlife governance, yet the intersection of wildlife studies and commons scholarship is not well studied. We reviewed existing wildlife-hunting scholarship, drawing on a database of 1,410 references, to examine the current overlap with commons scholarship through multiple methods, including social network analysis and deductive coding. We found that a very small proportion of wildlife scholarship incorporated commons theories and frameworks. The social network of wildlife scholarship was densely interconnected with several major publication clusters, whereas the wildlife commons scholarship was sparse and isolated. Despite the overarching gap between wildlife and commons scholarship, a few scholars are studying wildlife commons. The small body of scholarship that bridges these disconnected literatures provides valuable insights into the understudied relational dimensions of wildlife and other overlapping common-pool resources. We suggest increased engagement among wildlife and commons scholars and practitioners to improve the state of knowledge and practice of wildlife governance across regions, particularly for bushmeat hunting in the tropics, which is presently understudied through a common-pool resource lens. Our case study of the Republic of Congo showed how the historical context and interrelationships between hunting and forest rights are essential to understanding the current state of wildlife governance and potential for future interventions. A better understanding of the interconnections between wildlife and overlapping common-pool resource systems may be key to understanding present wildlife governance challenges and advancing the common-pool resource research agenda.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Animais Selvagens , Congo , Bolsas de Estudo , Humanos
4.
Depress Anxiety ; 34(8): 671-678, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27921349

RESUMO

BACKGROUND: Based on experimental research on threat extinction, individuals exposed to repeated traumatic events may have impaired outcome in exposure therapy compared to those who have experienced a single trauma (Lang & McTeague, ). This study examined whether repeated trauma exposure predicts smaller changes in self-reported distress during imaginal exposure and worse outcomes for patients with posttraumatic stress disorder (PTSD). METHODS: Adults (N = 116) with chronic PTSD received up to 10 sessions of prolonged exposure (PE) therapy. Trauma exposure was assessed via interview and number of traumatic events were summed for each participant. To examine reductions in distress during treatment, mean and peak values of distress during imaginal exposure were calculated for the first imaginal session (initial distress activation) and subsequent sessions (between-session change in distress). Change in PTSD symptoms from pre- to posttreatment and follow-up provided an additional index of outcome. RESULTS: In-session distress during imaginal exposure decreased over the course of treatment. PTSD symptoms also decreased over treatment, with gains being maintained through follow-up. Repeated trauma exposure was not significantly correlated with initial distress activation. Additionally, linear mixed-model analyses showed no significant association between repeated trauma exposure and between-session change in distress or PTSD symptoms. CONCLUSIONS: Contrary to recent speculation, repeated trauma exposure did not predict less change in self-reported distress during imaginal exposure or worse PTSD outcomes. The bench-to-bedside linkage of threat extinction to exposure therapy is discussed, noting strengths and weaknesses. Patients with repeated trauma exposure show reductions in distress with exposure treatment and benefit from PE as much as patients with single-exposure trauma histories.


Assuntos
Terapia Implosiva/métodos , Avaliação de Resultados em Cuidados de Saúde , Trauma Psicológico/terapia , Transtornos de Estresse Pós-Traumáticos/terapia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Trauma Psicológico/complicações , Transtornos de Estresse Pós-Traumáticos/etiologia
5.
Mod Phys Lett B ; 28(30)2014 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-25705067

RESUMO

Neutron reflectometry (NR) was used to examine various live cells adhesion to quartz substrates under different environmental conditions, including flow stress. To the best of our knowledge, these measurements represent the first successful visualization and quantization of the interface between live cells and a substrate with sub-nanometer resolution. In our first experiments, we examined live mouse fibroblast cells as opposed to past experiments using supported lipids, proteins, or peptide layers with no associated cells. We continued the NR studies of cell adhesion by investigating endothelial monolayers and glioblastoma cells under dynamic flow conditions. We demonstrated that neutron reflectometry is a powerful tool to study the strength of cellular layer adhesion in living tissues, which is a key factor in understanding the physiology of cell interactions and conditions leading to abnormal or disease circumstances. Continuative measurements, such as investigating changes in tumor cell - surface contact of various glioblastomas, could impact advancements in tumor treatments. In principle, this can help us to identify changes that correlate with tumor invasiveness. Pursuit of these studies can have significant medical impact on the understanding of complex biological problems and their effective treatment, e.g. for the development of targeted anti-invasive therapies.

6.
Trends Microbiol ; 32(2): 120-121, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38071163

RESUMO

Coral reefs are facing unprecedented anthropogenic pressures impacting critical processes such as recruitment of juvenile corals. Through larval choice assays and co-occurrence network analyses, a recent study by Turnlund et al. identified microbial taxa within reef biofilms that positively correlate and therefore have potential key roles in inducing coral settlement.


Assuntos
Antozoários , Animais , Recifes de Corais , Larva
7.
Psychooncology ; 22(7): 1501-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22887054

RESUMO

BACKGROUND: This study examined how language reflective of emotional and social processes during a cancer-related discussion relates to patient, couple, and family adjustment after breast cancer. It investigated whether emotional expression or relational focus, manifested in language use, indicates healthy family coping following breast cancer. METHODS: Family members each completed measures of adjustment (Family Environment Scale, Dyadic Adjustment Scale, and patient Profile of Mood States) and engaged in a 15-min family discussion about how they have coped with breast cancer. Transcripts from the discussion were submitted to a text-analysis software program to obtain frequency of positive and negative emotion words, and personal pronouns spoken by each family member. The relationship between self-reports of adjustment and frequency of language use during the family discussion was analyzed with regression models. RESULTS: Partners' positive emotion words were indicative of better family adjustment, patients' negative emotion words indicated greater family conflict, and sons' and daughters' anger words indicated poorer adjustment, whereas their anxiety words indicated better family adjustment. Partner we-talk was related to better dyadic adjustment, and couples' 'you' was somewhat related to worse adjustment at all levels. CONCLUSIONS: Important information about how a family copes with breast cancer can be obtained by attending to families' emotional and relational language. This study suggests that clinicians and members of families' support networks can gauge how well a family has adapted after the breast cancer experience by attending to the type of words that each family member uses to describe how they coped with breast cancer.


Assuntos
Adaptação Psicológica , Neoplasias da Mama/psicologia , Família/psicologia , Linguística , Cônjuges/psicologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Comunicação , Emoções , Feminino , Humanos , Relações Interpessoais , Pessoa de Meia-Idade , Parceiros Sexuais/psicologia , Ajustamento Social , Apoio Social , Inquéritos e Questionários , Adulto Jovem
8.
Fluids Barriers CNS ; 20(1): 61, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37596666

RESUMO

BACKGROUND: Hydrocephalus is a pathological accumulation of cerebrospinal fluid (CSF), leading to ventriculomegaly. Hydrocephalus may be primary or secondary to traumatic brain injury, infection, or intracranial hemorrhage. Regardless of cause, current treatment involves surgery to drain the excess CSF. Importantly, there are no long-term, effective pharmaceutical treatments and this represents a clinically unmet need. Many forms of hydrocephalus involve dysregulation in water and electrolyte homeostasis, making this an attractive, druggable target. METHODS: In vitro, a combination of electrophysiological and fluid flux assays was used to elucidate secretory transepithelial electrolyte and fluid flux in a human cell culture model of the choroid plexus epithelium and to determine the involvement of serum-, glucocorticoid-induced kinase 1 (SGK1). In vivo, MRI studies were performed in a genetic rat model of hydrocephalus to determine effects of inhibition of SGK1 with a novel inhibitor, SI113. RESULTS: In the cultured cell line, SI113 reduced secretory transepithelial electrolyte and fluid flux. In vivo, SI113 blocks the development of hydrocephalus with no effect on ventricular size of wild-type animals and no overt toxic effects. Mechanistically, the development of hydrocephalus in the rat model involves an increase in activated, phosphorylated SGK1 with no change in the total amount of SGK1. SI113 inhibits phosphorylation with no changes in total SGK1 levels in the choroid plexus epithelium. CONCLUSION: These data provide a strong preclinical basis for the use of SGK1 inhibitors in the treatment of hydrocephalus.


Assuntos
Lesões Encefálicas Traumáticas , Hidrocefalia , Humanos , Animais , Ratos , Glucocorticoides , Hidrocefalia/tratamento farmacológico , Fosforilação , Transporte Biológico
9.
Artigo em Inglês | MEDLINE | ID: mdl-38469373

RESUMO

Introduction: Dietary intake of whole grains and legumes and adequate physical activity (PA) have been associated with reduced colorectal cancer (CRC) risk. A single-blinded, two-arm, randomized, placebo-controlled pilot trial was implemented to evaluate the impact of a 12-week dietary intervention of rice bran + navy bean supplementation and PA education on metabolite profiles and the gut microbiome among individuals at high risk of CRC. Methods: Adults (n=20) were randomized 1:1 to dietary intervention or control. All participants received PA education at baseline. Sixteen study foods were prepared with either heat-stabilized rice bran + navy bean powder or Fibersol®-2 as a placebo. Intervention participants consumed 30 g rice bran + 30 g navy bean powder daily; those in the control group consumed 10 g placebo daily. Non-targeted metabolite profiling was performed by UPLC-MS/MS to evaluate plasma, urine, and stool at 0, 6, and 12 weeks. Stool was also analyzed for primary and secondary bile acids (BAs) and short chain fatty acids (SCFAs) by UPLC-MS/MS and microbial community structure via 16S amplicon sequencing. Two-way ANOVA was used to compare differences between groups for metabolites, and mixed models were used to compare differences between groups for BAs, SCFAs, and alpha and beta diversity measures of microbial community structure. Results: Across biological matrices, the intervention resulted in changes to several amino acid and lipid metabolites, compared to control. There was a 2.33-fold difference in plasma (p<0.001) and a 3.33-fold difference in urine (p=0.008) for the amino acid S-methylcysteine at 12 weeks. Fold-differences to 4-methoxyphenol sulfate in plasma and urine after 6 and 12 weeks (p<0.001) was a novel result from this combined rice bran and navy bean intervention in people. A 2.98-fold difference in plasma (p=0.002) and a 17.74-fold difference in stool (p=0.026) was observed for the lipid octadecenedioylcarnitine at 12 weeks. For stool BAs, 3-oxocholic acid was increased at 12 weeks compared to control within a subset of individuals (mean difference 16.2 ug/uL, p=0.022). No significant differences were observed between groups for stool SCFAs or microbial community structure. Discussion: Dietary intake of rice bran + navy beans demonstrates beneficial modulation of host and gut microbial metabolism and represents a practical and affordable means of increasing adherence to national guidelines for CRC control and prevention in a high-risk population.

10.
Psychol Sci ; 23(3): 261-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22282874

RESUMO

Divorce is a highly stressful event, and much remains to be learned about the factors that promote psychological resilience when marriages come to an end. In this study, divorcing adults (N = 109) completed a 4-min stream-of-consciousness recording about their marital separation at an initial laboratory visit. Four judges rated the degree to which participants exhibited self-compassion (defined by self-kindness, an awareness of one's place in shared humanity, and emotional equanimity) in their recordings. Judges evidenced considerable agreement in their ratings of participants' self-compassion, and these ratings demonstrated strong predictive utility: Higher levels of self-compassion at the initial visit were associated with less divorce-related emotional intrusion into daily life at the start of the study, and this effect persisted up to 9 months later. These effects held when we accounted for a number of competing predictors. Self-compassion is a modifiable variable, and if our findings can be replicated, they may have implications for improving the lives of divorcing adults.


Assuntos
Divórcio/psicologia , Empatia , Resiliência Psicológica , Autoimagem , Estresse Psicológico , Adulto , Emoções , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Pessoa de Meia-Idade
11.
Br J Clin Pharmacol ; 74(1): 147-53, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22257274

RESUMO

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: • Switching of patients' prescribed medicines within a therapeutic class is a common strategy to reduce prescribing costs, and in England a standard methodology has been promoted for switching processes. • Previous work to date suggests many patients are sceptical of generic products and switching may reduce compliance. • Patients' views on switching in general and the processes used have not been widely sought. WHAT THIS STUDY ADDS: • Patients may be less accepting of therapeutic switching programmes than is currently assumed. • Patients lacked understanding of the reason for the switch, despite standard letters and information leaflets being used, and few sought consultations. • Greater explanation of switching, possibly with involvement of community pharmacists, could lead to improved patient understanding and acceptance. INTRODUCTION Estimates suggest £200 million could be saved on prescribing costs in England by implementing medication switches. Few studies have evaluated patients' views or understanding of therapeutic switches. AIM: To obtain patient and pharmacist perspectives on switching from atorvastatin to simvastatin within an English Primary Care Trust (PCT). METHOD: All patients undergoing this switch, in seven self-selected East Lancashire practices, were sent postal questionnaires covering demographics, experiences and views regarding switching, with no reminder. Practice pharmacists implementing switches in these practices were interviewed about processes and their views on these. RESULTS: Pharmacists' switching process involved a standard letter offering a telephone consultation or appointment, plus an information leaflet. They considered most patients accepted switches, with few requesting consultations. Four hundred and ninety-four patients were identified and a response rate of 48.6% (240) obtained. The majority of respondents were happy with the switch (53.7%) and how they were informed (60.1%), with these findings being positively correlated. However over half (52.9%) did not understand the reason for the switch, particularly those with lower educational qualifications. Patients unhappy about switching perceived they had experienced side effects, or only learned of the switch on collecting a prescription or did not recall the consultation offer. Respondents indicated a preference for future switches to involve a face-to-face consultation (59.8%), with two-thirds (65.2%) agreeing that community pharmacists should explain medication switches. CONCLUSION: The standard process used, in line with nationally-designed templates, resulted in many patients being unhappy with or lacking understanding of switching statins, suggesting that improvements may be needed.


Assuntos
Prescrições de Medicamentos/economia , Medicamentos Genéricos/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Cooperação do Paciente/psicologia , Prescrições de Medicamentos/normas , Substituição de Medicamentos , Medicamentos Genéricos/economia , Inglaterra , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/economia , Farmacêuticos , Relações Médico-Paciente , Padrões de Prática Médica , Atenção Primária à Saúde/métodos , Encaminhamento e Consulta , Classe Social , Equivalência Terapêutica
12.
Mar Pollut Bull ; 181: 113903, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35843165

RESUMO

Algal turfs trap and retain particulates, however, little is known about the relationship between particulate accumulation and taxonomic composition of algal turfs. We investigated how particulate mass related to algal turf structure (length and density) and community composition (taxonomic and functional) on two disparate reefs. Particulate mass was positively related to algal turf length. By contrast, the relationship between particulate mass and turf density was more complex and followed a negative parabolic shape; density increased with particulate mass before stabilising and then declining. Community analyses showed taxonomic, but not functional group compositions differed significantly between reefs and with increasing particulate mass. Our results suggest high loads of particulates accumulated in algal turfs are related to a longer, lower density turf structure, typified by filamentous forms such as Cladophora. Changes in algal turf structure and composition could have a variety of bottom-up influences on coral reef ecosystems.


Assuntos
Antozoários , Recifes de Corais , Animais , Ecossistema , Sedimentos Geológicos/química
13.
Nutrients ; 14(3)2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-35276967

RESUMO

Rice bran contains essential nutrients, antioxidants, and bioactives with anti-inflammatory and diarrheal protective properties important for infants. This 6-month randomized controlled trial investigated the effects of heat-stabilized rice bran supplementation during Malian infant weaning. Fifty healthy 6-month-old infants were randomized to a rice bran intervention (N = 25) or non-intervention control group (N = 25). Intervention infants received dose-escalating rice bran supplementation for 6 months (1-5 g/day). Monthly infant dried blood spot and anthropometric measurements were collected. Dried blood spot metabolite abundances were compared monthly according to diet for six months. Supplementation resulted in favorable weight-for-age and weight-for-length z-score changes. Non-targeted dried blood spot-based metabolomics identified 796 metabolites, of which 33% had significant fold differences between groups (7-12 months). Lipids and amino acids represented 70.6% of the metabolites identified. Rice bran supplementation during infant weaning significantly modulated the metabolites involved in antioxidant defenses and with neuroactive properties including reduced glutathione, glycine, glutamate, cysteinylglycine, tryptophan betaine, and choline. These findings support rice bran as a weaning ingredient to meet infant nutritional requirements and with the potential to reduce oxidative stress and improve cognitive outcomes. This study provides evidence for dried blood spots as a cost-effective tool to detect infant biomarkers of nutritional and metabolic status.


Assuntos
Oryza , Pré-Escolar , Suplementos Nutricionais , Humanos , Lactente , Mali , Redes e Vias Metabólicas , Metabolômica , Oryza/química , Desmame
14.
PLoS One ; 17(11): e0273325, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36449458

RESUMO

While coral reefs in Australia have historically been a showcase of conventional management informed by research, recent declines in coral cover have triggered efforts to innovate and integrate intervention and restoration actions into management frameworks. Here we outline the multi-faceted intervention approaches that have developed in Australia since 2017, from newly implemented in-water programs, research to enhance coral resilience and investigations into socio-economic perspectives on restoration goals. We describe in-water projects using coral gardening, substrate stabilisation, coral repositioning, macro-algae removal, and larval-based restoration techniques. Three areas of research focus are also presented to illustrate the breadth of Australian research on coral restoration, (1) the transdisciplinary Reef Restoration and Adaptation Program (RRAP), one of the world's largest research and development programs focused on coral reefs, (2) interventions to enhance coral performance under climate change, and (3) research into socio-cultural perspectives. Together, these projects and the recent research focus reflect an increasing urgency for action to confront the coral reef crisis, develop new and additional tools to manage coral reefs, and the consequent increase in funding opportunities and management appetite for implementation. The rapid progress in trialling and deploying coral restoration in Australia builds on decades of overseas experience, and advances in research and development are showing positive signs that coral restoration can be a valuable tool to improve resilience at local scales (i.e., high early survival rates across a variety of methods and coral species, strong community engagement with local stakeholders). RRAP is focused on creating interventions to help coral reefs at multiple scales, from micro scales (i.e., interventions targeting small areas within a specific reef site) to large scales (i.e., interventions targeting core ecosystem function and social-economic values at multiple select sites across the Great Barrier Reef) to resist, adapt to and recover from the impacts of climate change. None of these interventions aim to single-handedly restore the entirety of the Great Barrier Reef, nor do they negate the importance of urgent climate change mitigation action.


Assuntos
Antozoários , Animais , Ecossistema , Austrália , Aclimatação , Água
15.
Phys Rev Lett ; 106(13): 138101, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21517422

RESUMO

Polymer-supported single lipid bilayers are models to study configurations of cell membranes. We used off-specular neutron scattering to quantify in-plane height-height correlations of interfacial fluctuations of such a lipid bilayer. As temperature decreased from 37 °C to 25 °C, the polymer swells and the polymer-supported lipid membrane deviates from its initially nearly planar structure. A correlation length characteristic of capillary waves changes from 30 µm at 37 °C to 11 µm at 25 °C, while the membrane bending rigidity remains roughly constant in this temperature range.


Assuntos
Membrana Celular/química , Bicamadas Lipídicas/química , Difração de Nêutrons , Polímeros/química , Temperatura
16.
J Phys Act Health ; 18(11): 1404-1411, 2021 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-34662855

RESUMO

BACKGROUND: Adenomatous polyps are associated with an increased risk of developing colorectal cancer. Physical activity (PA) and spending less time sedentary may reduce risk of polyp recurrence and cancer incidence. This study examined associations between PA, sedentary time, and stool metabolites in adults at high risk for developing colorectal cancer. METHODS: Participants were ≥18 years old with ≥1 adenomatous polyps removed in the previous 3 years. PA and sedentary time were assessed using an activPAL™ accelerometer. Stool samples were analyzed for short-chain fatty acids, and primary/secondary bile acid metabolites by mass spectrometry. Linear regression models examined associations between PA, sedentary time, and stool parameters, with dietary fiber as a covariate. RESULTS: Participants (N = 21) were 59 (9) years old and had a body mass index of 28.1 (3.35 kg/m2). Light-intensity PA was associated with butyrate (ß = 1.88; 95% confidence interval [CI], 0.477 to 3.291) and propionate (ß = 1.79; 95% CI, 0.862 to 2.724). Moderate to vigorous PA was associated with deoxycholic acid (ß = -6.13; 95% CI, -12.14 to -0.11) and ursodeoxycholic acid (ß = -0.45; 95% CI, -0.80 to -0.12) abundance. CONCLUSIONS: Both light and moderate to vigorous PA were associated with gut microbial metabolite production. These findings suggest the importance of examining PA intensity alongside stool metabolites for colorectal cancer prevention.


Assuntos
Neoplasias Colorretais , Exercício Físico , Acelerometria , Adolescente , Adulto , Criança , Neoplasias Colorretais/epidemiologia , Fibras na Dieta , Fezes , Humanos , Comportamento Sedentário
17.
Life (Basel) ; 11(6)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072344

RESUMO

In the search for life beyond Earth, distinguishing the living from the non-living is paramount. However, this distinction is often elusive, as the origin of life is likely a stepwise evolutionary process, not a singular event. Regardless of the favored origin of life model, an inherent "grayness" blurs the theorized threshold defining life. Here, we explore the ambiguities between the biotic and the abiotic at the origin of life. The role of grayness extends into later transitions as well. By recognizing the limitations posed by grayness, life detection researchers will be better able to develop methods sensitive to prebiotic chemical systems and life with alternative biochemistries.

18.
Biophys J ; 98(5): 793-9, 2010 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-20197032

RESUMO

Neutron reflectometry (NR) was used to examine live mouse fibroblast cells adherent on a quartz substrate in a deuterated phosphate-buffered saline environment at room temperature. These measurements represent the first, to our knowledge, successful visualization and quantization of the interface between live cells and a substrate with subnanometer resolution using NR. NR data, attributable to the adhesion of live cells, were observed and compared with data from pure growth medium. Independently of surface cell density, the average distance between the center of the cell membrane region and the quartz substrate was determined to be approximately 180 A. The membrane region ( approximately 80 A thick) contains the membranes of cells that are inhomogeneously distributed or undulating, likely conforming to the nonplanar geometry of the supporting adherence proteins. A second region of cell membranes at a greater distance from the substrate was not detectable by NR due to the resolution limits of the technique employed. Attachment of the live cell samples was confirmed by interaction with both distilled water and trypsin. Distinct changes in the NR data after exposure indicate the removal of cells from the substrate.


Assuntos
Biofísica/métodos , Fibroblastos/citologia , Nêutrons , Animais , Adesão Celular/efeitos dos fármacos , Contagem de Células , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Meios de Cultura/farmacologia , Fibroblastos/efeitos dos fármacos , Camundongos , Tripsina/farmacologia , Água/farmacologia
19.
Acta Crystallogr D Biol Crystallogr ; 66(Pt 11): 1237-43, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21041944

RESUMO

The nonperturbative nature of neutron reflectometry (NR) coupled with its isotopic sensitivity has made it an ideal candidate for the study of model biological membranes at the solid-liquid interface. In this article, methods are presented for the creation and characterization of supported model membranes which can mimic many of the critical attributes of cell membranes. It is demonstrated that NR can characterize the structure, composition and organization of model membranes deposited on solid, nanoporous and polymer supports. Additionally, in situ NR measurements of the interactions between model membranes and external stimuli are presented. Finally, an investigation of the adherence region of live mouse fibroblast cells is described.


Assuntos
Membrana Celular/química , Fibroblastos/química , Fibroblastos/metabolismo , Bicamadas Lipídicas/química , Nêutrons , Polímeros/química , Animais , Adesão Celular , Membrana Celular/metabolismo , Células Cultivadas , Membranas Artificiais , Camundongos , Modelos Biológicos , Nanopartículas/química , Estresse Oxidativo , Dióxido de Silício/química , Propriedades de Superfície , beta-Ciclodextrinas/química
20.
Langmuir ; 26(5): 3342-9, 2010 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-19921839

RESUMO

In order to investigate the process of noncovalent adsorption on glassy carbon surfaces, two terpyridine ligands 4-pyren-1-yl-N-[5-([2,2';6',2'']terpyridin-4'-yloxy)-pentyl]-butyramide (tpy~py) and N-[5-([2,2';6',2'']terpyridin-4'-yloxy)-pentyl]-2-naphthamide (tpy~nap) as well as the homoleptic cobalt(II) complexes of these ligands (Co(tpy~py)(2)(PF(6))(2) and Co(tpy~nap)(2)(PF(6))(2)) were synthesized. Electrochemical measurements in solution were used to characterize the transport behavior of these complexes and to verify that the polyaromatic portion of each ligand did not dramatically influence the electronic properties of the transition metal complex. The adsorption of the cobalt complexes above on glassy carbon electrode surfaces was then examined using cyclic voltammetry and was found to be well described by Langmuir or Frumkin isotherms. The free energy of adsorption for Co(tpy~py)(2)(PF(6))(2) was considerably larger than that for Co(tpy~nap)(2)(PF(6))(2): -41 versus -30 kJ/mol.

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