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1.
Appl Environ Microbiol ; 85(14)2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31076435

RESUMO

Glacial retreat is changing biogeochemical cycling in the Arctic, where glacial runoff contributes iron for oceanic shelf primary production. We hypothesize that in Svalbard fjords, microbes catalyze intense iron and sulfur cycling in low-organic-matter sediments. This is because low organic matter limits sulfide generation, allowing iron mobility to the water column instead of precipitation as iron monosulfides. In this study, we tested this with high-depth-resolution 16S rRNA gene libraries in the upper 20 cm at two sites in Van Keulenfjorden, Svalbard. At the site closer to the glaciers, iron-reducing Desulfuromonadales, iron-oxidizing Gallionella and Mariprofundus, and sulfur-oxidizing Thiotrichales and Epsilonproteobacteria were abundant above a 12-cm depth. Below this depth, the relative abundances of sequences for sulfate-reducing Desulfobacteraceae and Desulfobulbaceae increased. At the outer station, the switch from iron-cycling clades to sulfate reducers occurred at shallower depths (∼5 cm), corresponding to higher sulfate reduction rates. Relatively labile organic matter (shown by δ13C and C/N ratios) was more abundant at this outer site, and ordination analysis suggested that this affected microbial community structure in surface sediments. Network analysis revealed more correlations between predicted iron- and sulfur-cycling taxa and with uncultured clades proximal to the glacier. Together, these results suggest that complex microbial communities catalyze redox cycling of iron and sulfur, especially closer to the glacier, where sulfate reduction is limited due to low availability of organic matter. Diminished sulfate reduction in upper sediments enables iron to flux into the overlying water, where it may be transported to the shelf.IMPORTANCE Glacial runoff is a key source of iron for primary production in the Arctic. In the fjords of the Svalbard archipelago, glacial retreat is predicted to stimulate phytoplankton blooms that were previously restricted to outer margins. Decreased sediment delivery and enhanced primary production have been hypothesized to alter sediment biogeochemistry, wherein any free reduced iron that could potentially be delivered to the shelf will instead become buried with sulfide generated through microbial sulfate reduction. We support this hypothesis with sequencing data that showed increases in the relative abundance of sulfate reducing taxa and sulfate reduction rates with increasing distance from the glaciers in Van Keulenfjorden, Svalbard. Community structure was driven by organic geochemistry, suggesting that enhanced input of organic material will stimulate sulfate reduction in interior fjord sediments as glaciers continue to recede.


Assuntos
Ferro/metabolismo , Microbiota , Água do Mar/microbiologia , Enxofre/metabolismo , Regiões Árticas , Mudança Climática , Estuários , Sedimentos Geológicos/microbiologia , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Svalbard
2.
J Sleep Res ; 26(5): 606-613, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28401614

RESUMO

Tonic and phasic rapid eye movement (REM) sleep seem to represent two different brain states exerting different effects on epileptic activity. In particular, interictal spikes are suppressed strongly during phasic REM sleep. The reason for this effect is not understood completely. A different level of synchronization in phasic and tonic REM sleep has been postulated, yet never measured directly. Here we assessed the interictal spike rate across non-REM (NREM) sleep, phasic and tonic REM sleep in nine patients affected by drug resistant focal epilepsy: five with type II focal cortical dysplasia and four with hippocampal sclerosis. Moreover, we applied different quantitative measures to evaluate the level of synchronization at the local and global scale during phasic and tonic REM sleep. We found a lower spike rate in phasic REM sleep, both within and outside the seizure onset zone. This effect seems to be independent from the histopathological substrate and from the brain region, where epileptic activity is produced (temporal versus extra-temporal). A higher level of synchronization was observed during tonic REM sleep both on a large (global) and small (local) spatial scale. Phasic REM sleep appears to be an interesting model for understanding the mechanisms of suppression of epileptic activity.


Assuntos
Eletroencefalografia , Epilepsias Parciais/fisiopatologia , Sono REM/fisiologia , Encéfalo/patologia , Encéfalo/fisiopatologia , Epilepsias Parciais/patologia , Epilepsia/patologia , Epilepsia/fisiopatologia , Feminino , Hipocampo/patologia , Hipocampo/fisiopatologia , Humanos , Masculino , Malformações do Desenvolvimento Cortical do Grupo I/patologia , Malformações do Desenvolvimento Cortical do Grupo I/fisiopatologia , Convulsões/fisiopatologia
3.
BMC Geriatr ; 17(1): 154, 2017 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-28724351

RESUMO

BACKGROUND: Due to the demographic ageing process and the increasing number of pre-frail and frail individuals, new lifestyle interventions to enhance the quality of life (QoL) in community-dwelling older adults are necessary. Therefore, we performed a randomised controlled trial (RCT) to compare effects of a lay-led home-based physical and nutritional intervention programme with social support alone on different QoL domains in community-dwelling pre-frail and frail older adults. METHODS: In this analysis within a RCT (12 weeks), lay volunteers visited one-on-one pre-frail or frail older adults at home twice a week. Participants in the physical training and nutritional intervention (PTN) group performed six strength exercises and discussed main nutritional issues during each visit. The social support (SOSU) group received home visits twice a week for social exchanges. The QoL was assessed with the WHOQOL-BREF and the WHOQOL-OLD instruments. Analyses of covariance (ANCOVA) were used to examine differences between groups with baseline values as the covariate. Changes within groups were assessed with paired t-tests. RESULTS: Eighty participants (n = 39 in the PTN group and n = 41 in the SOSU group) were included. No significant differences were found between the two groups except in past, present and future activities domain [ß = 3.66 (95% confidence interval 0.13 to 7.18)] in favour of the PTN group. However, there was some evidence of greater within group improvements in the PTN group particularly in overall QoL, social relations and social participation. In the SOSU group, no significant effect was observed in any QoL domain. CONCLUSION: A combination of a home-based physical and nutritional intervention was not more effective compared to social support alone, on QoL in community-dwelling pre-frail and frail older adults. However, the small but significant improvement within the PTN group suggests that a home-based physical and nutritional intervention delivered by volunteers may influence the QoL in a positive way. TRIAL REGISTRATION: The study protocol was registered on 6 November 2013 at ClinicalTrials.gov (identifier: NCT01991639 ).


Assuntos
Intervenção Médica Precoce/métodos , Idoso Fragilizado/psicologia , Visita Domiciliar , Vida Independente/psicologia , Qualidade de Vida/psicologia , Apoio Social , Idoso , Idoso de 80 Anos ou mais , Intervenção Médica Precoce/tendências , Terapia por Exercício/métodos , Terapia por Exercício/psicologia , Feminino , Seguimentos , Visita Domiciliar/tendências , Humanos , Vida Independente/tendências , Masculino , Apoio Nutricional/métodos , Apoio Nutricional/psicologia , Apoio Nutricional/tendências
4.
Ann Oncol ; 26(12): 2375-91, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26371282

RESUMO

Immune checkpoint antibodies that augment the programmed cell death protein 1 (PD-1)/PD-L1 pathway have demonstrated antitumor activity across multiple malignancies, and gained recent regulatory approval as single-agent therapy for the treatment of metastatic malignant melanoma and nonsmall-cell lung cancer. Knowledge of toxicities associated with PD-1/PD-L1 blockade, as well as effective management algorithms for these toxicities, is pivotal in order to optimize clinical efficacy and safety. In this article, we review selected published and presented clinical studies investigating single-agent anti-PD-1/PD-L1 therapy and trials of combination approaches with other standard anticancer therapies, in multiple tumor types. We summarize the key adverse events reported in these studies and their management algorithms.


Assuntos
Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/imunologia , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/imunologia , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/imunologia , Animais , Anticorpos Monoclonais/farmacologia , Exantema/induzido quimicamente , Fadiga/induzido quimicamente , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Pneumonia/induzido quimicamente
5.
Eur J Neurol ; 22(10): 1337-54, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26255640

RESUMO

In recent years, evidence has emerged for a bidirectional relationship between sleep and neurological and psychiatric disorders. First, sleep-wake disorders (SWDs) are very common and may be the first/main manifestation of underlying neurological and psychiatric disorders. Secondly, SWDs may represent an independent risk factor for neuropsychiatric morbidities. Thirdly, sleep-wake function (SWF) may influence the course and outcome of neurological and psychiatric disorders. This review summarizes the most important research and clinical findings in the fields of neuropsychiatric sleep and circadian research and medicine, and discusses the promise they bear for the next decade. The findings herein summarize discussions conducted in a workshop with 26 European experts in these fields, and formulate specific future priorities for clinical practice and translational research. More generally, the conclusion emerging from this workshop is the recognition of a tremendous opportunity offered by our knowledge of SWF and SWDs that has unfortunately not yet entered as an important key factor in clinical practice, particularly in Europe. Strengthening pre-graduate and postgraduate teaching, creating academic multidisciplinary sleep-wake centres and simplifying diagnostic approaches of SWDs coupled with targeted treatment strategies yield enormous clinical benefits for these diseases.


Assuntos
Pesquisa Biomédica/tendências , Neurologia/tendências , Psiquiatria/tendências , Transtornos do Sono-Vigília/fisiopatologia , Sono/fisiologia , Humanos
6.
J Eur Acad Dermatol Venereol ; 27(3): e394-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23057648

RESUMO

BACKGROUND: Uveal melanoma is the most common intraocular neoplasm with a high tendency to metastasize predominantly to the liver. Prognostic parameters for progression and overall survival are not well defined. The aim of this study was to assess the value of pretherapeutic serum levels of C-reactive protein (CRP), lactate dehydrogenase, albumin and fibrinogen in patients with uveal melanoma and to evaluate their significance as prognostic parameters for survival. METHODS: Forty-nine patients with metastatic uveal melanoma treated between 2000 and 2010 were retrospectively analysed. The potential influence of levels of CRP, lactate dehydrogenase, fibrinogen and albumin as well as other commonly known prognostic variables on progression-free and overall survival were investigated. RESULTS: Patients' age and treatment with systemic chemotherapy were the only variables to show significant influences on progression-free and overall survival in a univariate analysis. Multivariate analysis confirmed the influence of these variables on progression-free survival, presence of metastasis, pretherapeutic CRP levels and treatment with systemic chemotherapy were associated with overall survival. CONCLUSION: In this patient cohort elevated pretherapeutic CRP and extent of metastasis are independent prognostic factors for decreased overall survival, whereas treatment with systemic chemotherapy showed a significant association with improved overall survival.


Assuntos
Biomarcadores/sangue , Melanoma/tratamento farmacológico , Neoplasias Uveais/tratamento farmacológico , Albuminas/metabolismo , Proteína C-Reativa/metabolismo , Intervalo Livre de Doença , Feminino , Fibrinogênio/metabolismo , Humanos , L-Lactato Desidrogenase/sangue , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Metástase Neoplásica , Prognóstico , Estudos Retrospectivos , Neoplasias Uveais/patologia
8.
Eur Geriatr Med ; 11(1): 169-177, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32297234

RESUMO

PURPOSE: The Joint Action Malnutrition in the Elderly (MaNuEL) Knowledge Hub was established to extend scientific knowledge, strengthen evidence-based practice, build a sustainable, transnational network of experts and harmonize research and clinical practice in the field of protein-energy malnutrition in older persons. This paper aims to summarize the main scientific results achieved during the 2-year project and to outline the recommendations derived. METHODS: 22 research groups from seven countries (Austria, France, Germany, Ireland, Spain, The Netherlands and New Zealand) worked together on 6 relevant domains of malnutrition-i.e. prevalence, screening, determinants, treatment, policy measures and education for health care professionals-making use of existing datasets, evidence and expert knowledge. RESULTS: Four systematic reviews, six secondary data analyses of existing cohort and intervention studies, two web-based surveys and one Delphi study were performed. In addition, a scoring system to rate malnutrition screening tools and a theoretical framework on the aetiology of malnutrition in older persons were developed. Based on these activities and taking existing evidence into consideration, 13 clinical practice, 9 research and 4 policy recommendations were developed. The MaNuEL Toolbox was created and made available to effectively distribute and disseminate the MaNuEL results and recommendations. CONCLUSIONS: The MaNuEL Knowledge Hub successfully achieved its aims. Results and recommendations will support researchers, healthcare professionals, policy-makers as well as educational institutes to advance their efforts in tackling the increasing problem of protein-energy malnutrition in the older population.


Assuntos
Desnutrição , Idoso , Idoso de 80 Anos ou mais , Pessoal de Saúde , Humanos , Desnutrição/diagnóstico , Programas de Rastreamento , Prevalência , Inquéritos e Questionários
9.
PLoS One ; 15(5): e0232447, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32379781

RESUMO

BACKGROUND: Malnutrition linked to noncommunicable diseases presents major health problems across Europe. The World Health Organisation encourages countries to conduct national dietary surveys to obtain data to inform public health policies designed to prevent noncommunicable diseases. METHODS: Data on 27334 participants aged 19-64y were harmonised and pooled across national dietary survey datasets from 12 countries across the WHO European Region. Weighted mean nutrient intakes were age-standardised using the Eurostat 2013 European Standard Population. Associations between country-level Gross Domestic Product (GDP) and key nutrients and nutrient densities were investigated using linear regression. The potential mitigating influence of participant-level educational status was explored. FINDINGS: Higher GDP was positively associated with total sugar intake (5·0% energy for each 10% increase in GDP, 95% CI 0·6, 9·3). Scandinavian countries had the highest vitamin D intakes. Participants with higher educational status had better nutritional intakes, particularly within lower GDP countries. A 10% higher GDP was associated with lower total fat intakes (-0·2% energy, 95% CI -0·3, -0·1) and higher daily total folate intakes (14µg, 95% CI 12, 16) in higher educated individuals. INTERPRETATION: Lower income countries and lower education groups had poorer diet, particularly for micronutrients. We demonstrate for the first time that higher educational status appeared to have a mitigating effect on poorer diet in lower income countries. It illustrates the feasibility and value of harmonising national dietary survey data to inform European policy regarding access to healthy diets, particularly in disadvantaged groups. It specifically highlights the need for strong policies supporting nutritional intakes, prioritising lower education groups and lower income countries.


Assuntos
Dieta , Desnutrição/epidemiologia , Fatores Socioeconômicos , Adulto , Inquéritos sobre Dietas , Dieta Saudável , Escolaridade , Ingestão de Energia , Europa (Continente)/epidemiologia , Feminino , Humanos , Renda , Modelos Lineares , Masculino , Desnutrição/prevenção & controle , Micronutrientes/administração & dosagem , Pessoa de Meia-Idade , Análise Multivariada , Estado Nutricional , Pobreza , Adulto Jovem
10.
Science ; 260(5114): 1626-9, 1993 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-17810204

RESUMO

About 70 percent of tropical western Atlantic mollusk species have become extinct since the Pliocene, which has led to perceptions of a corresponding decline in diversity. However, a compilation of gastropod species from Plio-Pleistocene faunas of the United States Atlantic coastal plain and from Recent western Atlantic faunas indicates that regional diversity has not changed since the Pliocene. Gastropod diversity in the Pliocene Pinecrest Beds in Florida approximates that seen today on either coast of Florida. Gastropod diversity is not demonstrably different in the Recent tropical western Atlantic than in the Recent tropical eastern Pacific. High extinction rates must have been balanced by high origination rates.

11.
Horm Metab Res ; 41(7): 573-9, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19322744

RESUMO

Highly active antiretroviral therapy (HAART) leads to lipodystrophy and is associated with detrimental changes in glucose and lipid metabolism. This study investigated the impact of rosiglitazone on insulin sensitivity, beta cell function, bone mineral density, and body composition in HIV+ nondiabetic subjects under HAART. In this randomized, double blind, placebo controlled parallel group study, 40 HIV+ subjects were treated with rosiglitazone 4 mg/day (R, n=23) or placebo (P, n=17) for 6 months. Glucose, insulin and C peptide concentrations were analyzed for assessing insulin sensitivity and secretion. Adiponectin and leptin were evaluated. Body fluid compartments were measured with bioelectrical impedance spectroscopy, and bone mineral density and body composition with Dual X Ray absorptiometry. Rosiglitazone improved peripheral insulin sensitivity (+36.7+/-15.7 ml/min/m (2), p=0.03, means+/-SEM), while no change was observed in P (+4.5+/-19.5 ml/min/m (2), p=0.55). Liver insulin resistance, beta cell activity, and hepatic insulin clearance did not change. Plasma adiponectin increased (R: +2.47+/-0.86 microg/ml, p=0.01 vs. P: +0.45+/-0.60, p=0.28). Rosiglitazone had no influence on body composition, fat distribution and bone mineral density but expanded extra-cellular fluid volume in HIV infected persons (R: +0.50+/-0.21 l, p=0.02 vs. P: 0.10+/-0.25 l, p=0.32). Lipid metabolism in P remained unchanged, in R total cholesterol and LDL cholesterol levels increased significantly (p<0.05). Rosiglitazone treatment resulted in improved peripheral insulin sensitivity with increased circulating adiponectin in HIV patients under HAART. No effect was seen on body fat distribution, bone mineral density, and weight. These side effects and their potential for cardiac risk must be weighed against the beneficial effects on glucose metabolism.


Assuntos
Terapia Antirretroviral de Alta Atividade/efeitos adversos , Composição Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Síndrome de Lipodistrofia Associada ao HIV/tratamento farmacológico , Hipoglicemiantes/administração & dosagem , Células Secretoras de Insulina/fisiologia , Insulina/metabolismo , Tiazolidinedionas/administração & dosagem , Adulto , Glicemia/efeitos dos fármacos , Método Duplo-Cego , Feminino , Síndrome de Lipodistrofia Associada ao HIV/metabolismo , Síndrome de Lipodistrofia Associada ao HIV/fisiopatologia , Humanos , Células Secretoras de Insulina/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Rosiglitazona
12.
Colorectal Dis ; 11(2): 162-7, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18462237

RESUMO

OBJECTIVE: 'Fast-track' rehabilitation has been shown to accelerate recovery, reduce general morbidity and decrease hospital stay after elective colonic surgery. Despite this evidence, there is no information on the acceptance and utilization of these concepts among the entirety of Austrian and German surgeons. METHOD: In 2006, a questionnaire concerning perioperative routines in elective, open colonic resection was sent to the chief surgeons of 1270 German and 120 Austrian surgical centres. RESULTS: The response rate was 63% in Austria (76 centres) and 30% in Germany (385 centres). Mechanical bowel preparation is used by the majority (Austria, 91%; Germany, 94%); the vertical incision is the standard method of approach to the abdomen in Austria (79%) and Germany (83%), nasogastric decompression tubes are rarely used, one-third of the questioned surgeons in both countries use intra-abdominal drains. Half of the surgical centres allow the intake of clear fluids on the day of surgery and one-fifth offer solid food on that day. Epidural analgesia is used in three-fourths of the institutions. CONCLUSION: Although there is an evident benefit of fast-track management, the survey shows that they are not yet widely used as a routine in Austria and Germany.


Assuntos
Colectomia/reabilitação , Assistência Perioperatória/métodos , Padrões de Prática Médica , Anestesia Epidural/estatística & dados numéricos , Áustria , Cirurgia Colorretal , Alemanha , Pesquisas sobre Atenção à Saúde , Humanos , Tempo de Internação
13.
Clin Nutr ; 38(6): 2477-2498, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-30685297

RESUMO

BACKGROUND & AIMS: Malnutrition in older adults results in significant personal, social, and economic burden. To combat this complex, multifactorial issue, evidence-based knowledge is needed on the modifiable determinants of malnutrition. Systematic reviews of prospective studies are lacking in this area; therefore, the aim of this systematic review was to investigate the modifiable determinants of malnutrition in older adults. METHODS: A systematic approach was taken to conduct this review. Eight databases were searched. Prospective cohort studies with participants of a mean age of 65 years or over were included. Studies were required to measure at least one determinant at baseline and malnutrition as outcome at follow-up. Study quality was assessed using a modified version of the Quality in Prognosis Studies (QUIPS) tool. Pooling of data in a meta-analysis was not possible therefore the findings of each study were synthesized narratively. A descriptive synthesis of studies was used to present results due the heterogeneity of population source and setting, definitions of determinants and outcomes. Consistency of findings was assessed using the schema: strong evidence, moderate evidence, low evidence, and conflicting evidence. RESULTS: Twenty-three studies were included in the final review. Thirty potentially modifiable determinants across seven domains (oral, psychosocial, medication and care, health, physical function, lifestyle, eating) were included. The majority of studies had a high risk of bias and were of a low quality. There is moderate evidence that hospitalisation, eating dependency, poor self-perceived health, poor physical function and poor appetite are determinants of malnutrition. Moderate evidence suggests that chewing difficulties, mouth pain, gum issues co-morbidity, visual and hearing impairments, smoking status, alcohol consumption and physical activity levels, complaints about taste of food and specific nutrient intake are not determinants of malnutrition. There is low evidence that loss of interest in life, access to meals and wheels, and modified texture diets are determinants of malnutrition. Furthermore, there is low evidence that psychological distress, anxiety, loneliness, access to transport and wellbeing, hunger and thirst are not determinants of malnutrition. There appears to be conflicting evidence that dental status, swallowing, cognitive function, depression, residential status, medication intake and/or polypharmacy, constipation, periodontal disease are determinants of malnutrition. CONCLUSION: There are multiple potentially modifiable determinants of malnutrition however strong robust evidence is lacking for the majority of determinants. Better prospective cohort studies are required. With an increasingly ageing population, targeting modifiable factors will be crucial to the effective treatment and prevention of malnutrition.


Assuntos
Desnutrição , Idoso , Idoso de 80 Anos ou mais , Cognição , Exercício Físico , Feminino , Hospitalização , Humanos , Masculino , Desnutrição/epidemiologia , Desnutrição/fisiopatologia , Desnutrição/psicologia , Fatores de Risco
14.
Sci Total Environ ; 635: 228-239, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29674257

RESUMO

Mercury (Hg) was discharged in the late 1960s into the Penobscot River by the Holtra-Chem chlor-alkali production facility, which was in operation from 1967 to 2000. To assess the transport and distribution of total Hg, and recovery of the river and estuary system from Hg pollution, physical and radiochemical data were assembled from sediment cores collected from 58 of 72 coring stations sampled in 2009. These stations were located throughout the lower Penobscot River, and included four principal study regions, the Penobscot River (PBR), Mendall Marsh (MM), the Orland River (OR), and the Penobscot estuary (ES). To provide the geochronology required to evaluate sedimentary total Hg profiles, 58 of 72 sediment cores were dated using the atmospheric radionuclide tracers 137Cs, 210Pb, and 239,240Pu. Sediment cores were assessed for depths of mixing, and for the determination of sediment accumulation rates using both geochemical (total Hg) and radiochemical data. At most stations, evidence for significant vertical mixing, derived from profiles of 7Be (where possible) and porosity, was restricted to the upper ~1-3cm. Thus, historic profiles of both total Hg and radionuclides were only minimally distorted, allowing a reconstruction of their depositional history. The pulse input tracers 137Cs and 239,240Pu used to assess sediment accumulation rates agreed well, while the steady state tracer 210Pb exhibited weaker agreement, likely due to irregular lateral sediment inputs.


Assuntos
Estuários , Sedimentos Geológicos/análise , Mercúrio/análise , Rios/química , Poluentes Químicos da Água/análise , Maine
15.
J Phys Condens Matter ; 30(20): 205401, 2018 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-29611814

RESUMO

In BaTiO3 the phase transition from tetragonal to cubic is connected with the disappearance of the ferroelectric polarization. In photoelectron spectroscopy huge transient shifts in the binding energies of all core-level photoemission lines have been observed while heating and cooling through the Curie temperature. Excitation energies from 2 keV to 6 keV have been used to show this to be a bulk effect and not a surface effect alone. These observations are discussed in terms of charging, which results from the disappearance of the ferroelectric polarization. This mechanism has previously been proposed as the origin of electron emission in ferroelectric materials. Besides the jump-like shifts, additional permanent shifts in binding energies have been observed for the tetragonal and the cubic phase. These experimental shifts have been related to theoretical ones from ab initio calculations. In addition to BaTiO3 single crystals, systems with CoFe2O4 and NiFe2O4 overlayers on BaTiO3 have been investigated. The low conductivity of these layers sets them apart from metallic overlayers like Fe or Co, where the shifts are suppressed. This difference adds further support for charging as the origin of the effect.

16.
Sci Total Environ ; 622-623: 172-183, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29223075

RESUMO

We examined total mercury (Hg) distributions in sediments from the Penobscot River and estuary, Maine, a site of extensive Hg releases from HoltraChem (1967-2000). Our objectives were to quantify: (1) bottom sediment Hg inventories (upper ~1m; 50-100 y); (2) sediment accumulation rates; and (3) contemporary Hg fluxes to bottom sediments; by sampling the Penobscot River (PBR), Mendall Marsh (MM), the Orland River (OR) and the Penobscot estuary (ES). Hg was rapidly distributed here, and the cumulative total (9.28 metric tons) associated with sediments system-wide was within the range released (6-12 metric tons). Evidence of sediment/Hg remobilization was observed in cores primarily from the PBR, and to a lesser extent the ES, whereas cores from MM, most of the OR, the ES, and half from the PBR exhibited sharp peaks in Hg concentrations at depth, followed by gradual decreases towards the surface. Based on background PBR sediment Hg concentrations (100ngg-1), "elevated" (300ngg-1), or "highly elevated" (600ngg-1) Hg concentrations in sediments, and resulting inventories, we assessed impact levels ("elevated"≥270, or "highly elevated"≥540mgm-2). 71% of PBR stations had "elevated", and 29% had "highly elevated" Hg inventories; 45% of MM stations had "elevated", and 27% had "highly elevated" inventories; 80% of OR stations had "elevated" inventories only; and 17% of ES stations had "elevated" inventories only. Most "highly elevated" stations were located within 8km of HoltraChem, in MM, in the PBR, and in the OR. Near-surface sediments in the OR, PBR and MM were all "highly elevated", while those in the ES were "elevated", on average. Mean Hg fluxes to bottom sediments were greatest in the OR (554), followed by the PBR (469), then MM (452), and finally the ES (204ngcm-2y-1).

17.
Clin Pharmacol Ther ; 81(4): 580-5, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17235334

RESUMO

Thiazolidinediones (TZD) may improve insulin resistance in patients with diabetes and HIV. The novel adipocytokines visfatin and retinol-binding protein-4 (RBP-4) have been proposed to influence the development of impaired glucose tolerance. The impact of TZD on these cytokines is yet unknown. In this randomized, double-blind, placebo-controlled parallel group study, 37 lean HIV-positive subjects aged 19-50 years were treated with 8 mg/day rosiglitazone (n=20) or placebo (n=17) for 6 months. Insulin sensitivity was estimated from the homeostasis model assessment (HOMA) index. Fasting visfatin, RBP-4, leptin, and adiponectin plasma concentrations were analyzed by immunoassays. Rosiglitazone had no effect on impaired insulin sensitivity, but increased median plasma visfatin from 6.2 ng/ml (95% CI: 5.9; 6.5) to 13.7 ng/ml (12.6; 19.1) (P<0.001) and adiponectin from 3.2 ng/ml (2.2; 4.0) to 4.0 ng/ml (3.3; 8.5; P<0.001). RBP-4 was lowered from 21.0 ng/ml (19.6; 23.1) to 16.3 ng/ml (15.2; 17.0; P<0.001), and leptin concentrations were unchanged. Adipocytokine concentrations were stable in subjects receiving placebo, where a deterioration in insulin sensitivity was detectable (P<0.05). Changes in visfatin and RBP-4 were correlated in subjects receiving rosiglitazone (r=-0.64, P<0.01) but not placebo (r=0.12, P=0.15). TZD treatment affects circulating adipocytokine concentrations in subjects with HIV. Reductions in RBP-4 and increases in visfatin may contribute to the pharmacodynamic action of TZD on glucose homeostasis. Quantification of adipocytokines might be useful to assess TZD treatment effectiveness in insulin-resistant subjects with HIV.


Assuntos
Citocinas/sangue , Soropositividade para HIV/sangue , Hipoglicemiantes/sangue , Hipoglicemiantes/farmacologia , Proteínas de Ligação ao Retinol/metabolismo , Tiazolidinedionas/farmacologia , Adiponectina/sangue , Tecido Adiposo/metabolismo , Adulto , Citocinas/metabolismo , Feminino , Humanos , Resistência à Insulina , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Nicotinamida Fosforribosiltransferase , Análise de Regressão , Proteínas Plasmáticas de Ligação ao Retinol , Rosiglitazona , Tiazolidinedionas/sangue
18.
Nanotechnology ; 18(49): 495202, 2007 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-20442468

RESUMO

In this work we investigate the electrical transport properties and growth conditions of tungsten carbon (WC) and palladium carbon (PdC) nanostructures on Si substrates using a focused ion beam and scanning electron microscope. In situ energy dispersive x-ray (EDX) characterizations reveal that electron-beam-induced WC and PdC nanostructure depositions (EBID) show a lower metal concentration (below 3% atomic percentage) than in ion-beam-induced deposition (IBID) (above 20%). In the case of PdC the growth pattern and the Pd/C content were optimized by adjusting the deposition temperature of the precursor material. In situ measurements of the resistivity of the nanostructures as a function of thickness reveal a minimum at a thickness approximately 200 nm. The lowest resistivity obtained for the PdC and WC structures is two orders of magnitude higher than the corresponding bulk values for pure Pd and W. The EBID samples show a non-metallic behaviour due to the low metal content. The temperature and magnetic field dependence of the IBID structures reveal a behaviour similar to disordered or granular conductors. The upper critical field and critical current density of the WC structures were measured below the superconducting critical temperature of approximately 5 K.

19.
Arch Gerontol Geriatr ; 68: 25-32, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27588891

RESUMO

BACKGROUND: In older adults, fear of falling (FOF) leads to a decline in daily physical activity quality of life and an increased risk of falling. The aim of this randomised controlled trial was to assess the effects of a 12-week home-based intervention program carried out by lay volunteers on FOF in frail older adults. METHODS: Thirty-nine participants were randomised to a physical training and nutrition (PTN) group and 41 participants to a social support (SOSU) group. In the PTN group, strength training and conversation about optimising nutrition were performed twice weekly, and the SOSU group received home visits without intervention. FOF and change of FOF were assessed using the Falls Efficacy Scale - International (FES-I). The Short Physical Performance Battery (SPPB), the Physical Activity Scale for the Elderly (PASE) and maximum handgrip strength and their changes were also assessed. RESULTS: The mean FES-I score at baseline was 42.7 points and was significantly associated with the SPPB and PASE scores. The FES-I score significantly changed in the PTN group from 44.1 to 39.9 points over the course of the intervention. Twenty-seven percent of the participants showed a decreased FES-I score of at least 4 points. This decrease was associated with an increase in the SPPB score and an increase in handgrip strength CONCLUSION: A 12-week structured physical training and nutrition intervention carried out by lay volunteers, which leads to an increase in physical activity and improved physical performance, can reduce FOF by about 10%.


Assuntos
Acidentes por Quedas/prevenção & controle , Medo , Idoso Fragilizado , Assistência Domiciliar , Voluntários , Idoso de 80 Anos ou mais , Dieta , Feminino , Humanos , Masculino , Treinamento Resistido , Apoio Social
20.
Clin Nutr ; 36(1): 49-64, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27642056

RESUMO

BACKGROUND: A lack of agreement on definitions and terminology used for nutrition-related concepts and procedures limits the development of clinical nutrition practice and research. OBJECTIVE: This initiative aimed to reach a consensus for terminology for core nutritional concepts and procedures. METHODS: The European Society of Clinical Nutrition and Metabolism (ESPEN) appointed a consensus group of clinical scientists to perform a modified Delphi process that encompassed e-mail communication, face-to-face meetings, in-group ballots and an electronic ESPEN membership Delphi round. RESULTS: Five key areas related to clinical nutrition were identified: concepts; procedures; organisation; delivery; and products. One core concept of clinical nutrition is malnutrition/undernutrition, which includes disease-related malnutrition (DRM) with (eq. cachexia) and without inflammation, and malnutrition/undernutrition without disease, e.g. hunger-related malnutrition. Over-nutrition (overweight and obesity) is another core concept. Sarcopenia and frailty were agreed to be separate conditions often associated with malnutrition. Examples of nutritional procedures identified include screening for subjects at nutritional risk followed by a complete nutritional assessment. Hospital and care facility catering are the basic organizational forms for providing nutrition. Oral nutritional supplementation is the preferred way of nutrition therapy but if inadequate then other forms of medical nutrition therapy, i.e. enteral tube feeding and parenteral (intravenous) nutrition, becomes the major way of nutrient delivery. CONCLUSION: An agreement of basic nutritional terminology to be used in clinical practice, research, and the ESPEN guideline developments has been established. This terminology consensus may help to support future global consensus efforts and updates of classification systems such as the International Classification of Disease (ICD). The continuous growth of knowledge in all areas addressed in this statement will provide the foundation for future revisions.


Assuntos
Desnutrição/diagnóstico , Desnutrição/terapia , Política Nutricional , Terminologia como Assunto , Caquexia/complicações , Consenso , Dieta , Nutrição Enteral , Fragilidade/complicações , Humanos , Avaliação Nutricional , Estado Nutricional , Obesidade/complicações , Sobrepeso/complicações , Nutrição Parenteral , Sarcopenia/complicações , Sociedades Científicas
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