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1.
Environ Sci Technol ; 57(51): 21779-21790, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38091466

RESUMO

Arbuscular mycorrhizal (AM) fungi play an important role in organic matter (OM) stabilization in Fe ore tailings for eco-engineered soil formation. However, little has been understood about the AM fungi-derived organic signature and organo-mineral interactions in situ at the submicron scale. In this study, a compartmentalized cultivation system was used to investigate the role of AM fungi in OM formation and stabilization in tailings. Particularly, microspectroscopic analyses including synchrotron-based transmission Fourier transform infrared (FTIR) and scanning transmission X-ray microspectroscopy combined with near-edge X-ray absorption fine structure spectroscopy (STXM-NEXAFS) were employed to characterize the chemical signatures at the AM fungal-mineral and mineral-OM interfaces at the submicron scale. The results indicated that AM fungal mycelia developed well in the tailings and entangled mineral particles for aggregation. AM fungal colonization enhanced N-rich OM stabilization through organo-mineral association. Bulk spectroscopic analysis together with FTIR mapping revealed that fungi-derived lipids, proteins, and carbohydrates were associated with Fe/Si minerals. Furthermore, STXM-NEXAFS analysis revealed that AM fungi-derived aromatic, aliphatic, and carboxylic/amide compounds were heterogeneously distributed and trapped by Fe(II)/Fe(III)-bearing minerals originating from biotite-like minerals weathering. These findings imply that AM fungi can stimulate mineral weathering and provide organic substances to associate with minerals, contributing to OM stabilization and aggregate formation as key processes for eco-engineered soil formation in tailings.


Assuntos
Compostos Férricos , Micorrizas , Compostos Férricos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Síncrotrons , Análise de Fourier , Minerais/química , Solo/química , Ferro
2.
J Environ Manage ; 344: 118488, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37393870

RESUMO

Mineral tailings dams pose high pollution risks to the environment and catastrophic failures. Dry stacking has been identified as a promising alternative to mitigate these risks and offers various benefits to the mining industry but lacks systematic research outcomes. To facilitate dry stacking, coal tailings slurries were dewatered using either filtration or centrifugation methods, resulting in a semi-solid form (cake) that can be safely disposed of. The handleability and disposability of these cakes are greatly influenced by the selection of chemical aids (such as polymer flocculants) and the mechanical dewatering technique employed. The effects of polyacrylamide (PAM) flocculants with a range of molecular weight, charge, and charge density are presented. Coal tailings samples with differences in clay mineralogy were dewatered using press filtration, solid bowl centrifugation, and natural air drying. Handleability and disposability of the tailings were assessed by their rheological properties, including yield stress, adhesive and cohesive stresses, and stickiness. Residue moisture, type of polymer flocculants, and clay mineralogy were found to be crucial factors affecting the handleability and disposability of the dewatered cakes. The tailing yield stress (shear strength) increased as the solid concentration increased. In the semi-solid regime (above 60 wt% solids), the tailings displayed stiff exponential growth. Similar trends were observed for stickiness and adhesive/cohesive energy of the tailings with a steel (truck) surface. Adding polymer flocculants increased the shear strength of the dewatered tailings by 10-15%, thus favouring disposability. However, the polymer selection for coal tailing handling and processing is a trade-off between its disposability and handleability, which requires a multi-criteria decision-making process. The current results also suggested that cationic PAM could be most suitable for dewatering by press filtration, while anionic PAM should be selected for dewatering by solid bowl centrifugation.


Assuntos
Carvão Mineral , Polímeros , Argila , Resistência ao Cisalhamento , Poluição Ambiental
3.
BMC Geriatr ; 22(1): 527, 2022 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-35761212

RESUMO

BACKGROUND: Frailty in older people is associated with increased risk of falls, longer length of stay in hospital, increased risk of institutionalisation and death. Frailty can be measured using validated tools. Multi-component frailty interventions are recommended in clinical practice guidelines but are not routinely implemented in clinical practice. METHODS: The Frailty in Older people: Rehabilitation, Treatment, Research Examining Separate Settings (FORTRESS) trial is a multisite, hybrid type II, stepped wedge, cluster, randomised trial with blinded assessment and intention-to-treat analysis being conducted in Australia. The study aims to determine the effectiveness and cost-effectiveness of an embedded individualised multicomponent frailty intervention (commencing in hospital and continuing in the community) on readmissions, frailty and quality of life when compared with usual care. Frail older people admitted to study wards with no significant cognitive impairment, who are expected to return home after discharge, will be eligible to participate. Participants will receive extra sessions of physiotherapy, pharmacy, and dietetics during their admission. A Community Implementation Facilitator will coordinate implementation of the frailty management strategies and primary network liaison. The primary outcome is number of days of non-elective hospital readmissions during 12 month follow-up period. Secondary outcomes include frailty status measured using the FRAIL scale; quality of life measured using the EQ-5D-5L; and time-to-event for readmission and readmission rates. The total cost of delivering the intervention will be assessed, and cost-effectiveness analyses will be conducted. Economic evaluation will include analyses for health outcomes measured in terms of the main clinical outcomes. Implementation outcomes will be collected as part of a process evaluation. Recruitment commenced in 2020 and we are aiming to recruit 732 participants over the three-year duration of the study. DISCUSSION: This study will reveal whether intervening with frail older people to address factors contributing to frailty can reduce hospital readmissions and improve frailty status and quality of life. If the FORTRESS intervention provides a clinically significant and cost-effective result, it will demonstrate an improved approach to treating frail patients, both in hospital and when they return home. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12620000760976p . ANZCTR registered 24 July 2020.


Assuntos
Fragilidade , Acidentes por Quedas , Idoso , Austrália/epidemiologia , Fragilidade/diagnóstico , Fragilidade/terapia , Hospitalização , Humanos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Bull World Health Organ ; 99(1): 50-61, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33658734

RESUMO

OBJECTIVE: To investigate factors associated with survival after out-of-hospital cardiac arrest in Viet Nam. METHODS: We did a multicentre prospective observational study of people (> 18 years) presenting with out-of-hospital cardiac arrest (not caused by trauma) to three tertiary hospitals in Viet Nam from February 2014 to December 2018. We collected data on characteristics, management and outcomes of patients with out-of-hospital cardiac arrest and compared these data by type of transportation to hospital and survival to hospital admission. We assessed factors associated with survival to admission to and discharge from hospital using logistic regression analysis. FINDINGS: Of 590 eligible people with out-of-hospital cardiac arrest, 440 (74.6%) were male and the mean age was 56.1 years (standard deviation: 17.2). Only 24.2% (143/590) of these people survived to hospital admission and 14.1% (83/590) survived to hospital discharge. Most cardiac arrests (67.8%; 400/590) occurred at home, 79.4% (444/559) were witnessed by bystanders and 22.3% (124/555) were given cardiopulmonary resuscitation by a bystander. Only 8.6% (51/590) of the people were taken to hospital by the emergency medical services and 32.2% (49/152) received pre-hospital defibrillation. Pre-hospital defibrillation (odds ratio, OR: 3.90; 95% confidence interval, CI: 1.54-9.90) and return of spontaneous circulation in the emergency department (OR: 2.89; 95% CI: 1.03-8.12) were associated with survival to hospital admission. Hypothermia therapy during post-resuscitation care was associated with survival to discharge (OR: 5.44; 95% CI: 2.33-12.74). CONCLUSION: Improvements are needed in the emergency medical services in Viet Nam such as increasing bystander cardiopulmonary resuscitation and public access defibrillation, and improving ambulance and post-resuscitation care.


Assuntos
Parada Cardíaca Extra-Hospitalar/mortalidade , Parada Cardíaca Extra-Hospitalar/terapia , Serviços Médicos de Emergência , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Análise de Sobrevida , Transporte de Pacientes , Vietnã/epidemiologia
5.
Environ Sci Technol ; 55(19): 13045-13060, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34565140

RESUMO

Dissolved organic matter (DOM) plays an important role in soil structure and biogeochemical function development, which are fundamental for the eco-engineering of tailings-soil formation to underpin sustainable tailings rehabilitation. In the present study, we have characterized the DOM composition and its molecular changes in an alkaline Fe ore tailing primed with organic matter (OM) amendment and plant colonization. The results demonstrated that microbial OM decomposition dramatically increased DOM richness and average molecular weight, as well as its degree of unsaturation, aromaticity, and oxidation in the tailings. Plant colonization drove molecular shifts of DOM by depleting the unsaturated compounds with a high value of nominal oxidation state of carbon (NOSC), such as tannin-like and carboxyl-rich polycyclic-like compounds. This may be partially related to their sequestration by secondary Fe-Si minerals formed from rhizosphere-driven mineral weathering. Furthermore, the molecular shifts of DOM may have also resulted from plant-regulated microbial community changes, which further influenced DOM molecules through microbial-DOM interactions. These findings contribute to the understanding of DOM biogeochemistry and ecofunctionality in the tailings during early pedogenesis driven by OM input and pioneer plant/microbial colonization, providing an important basis for the development of strategies and technologies toward the eco-engineering of tailings-soil formation.


Assuntos
Microbiota , Poluentes do Solo , Minerais , Rizosfera , Solo , Poluentes do Solo/análise
6.
Br J Clin Pharmacol ; 86(12): 2414-2423, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32374041

RESUMO

AIMS: To determine the prevalence of potentially inappropriate medication (PIM) use at hospital admission and discharge, and the contribution to hospital admission among residential aged care facility residents with and without dementia. METHODS: We conducted a secondary analysis using data from a multihospital prospective cohort study involving consecutively admitted older adults, aged 75 years or older, who were taking 5 or more medications prior to hospital admission and discharged to a residential aged care facility in South Australia. PIM use was identified using the 2015 Screening Tool for Older Persons' Prescription and 2019 Beers criteria. An expert panel of clinicians with geriatric medicine expertise evaluated the contribution of PIM to hospital admission. RESULTS: In total, 181 participants were included, the median age was 87.5 years and 54.7% were female. Ninety-one (50.3%) had a diagnosis of dementia. Participants with dementia had fewer PIMs, according to at least 1 of the 2 screening criteria, than those without dementia, at admission (dementia: 76 [83.5%] vs no dementia: 84 [93.3%], P = .04) and discharge (78 [85.7%] vs 83 [92.2%], P = .16). PIM use was causal or contributory to the admission in 28.1% of study participants (n = 45) who were taking at least 1 PIM at admission. CONCLUSIONS: Over 80% of acutely admitted older adults took PIMs at hospital admission and discharge and for over a quarter of these people the admissions were attributable to PIM use. Hospitalisation presents an opportunity for comprehensive medication reviews, and targeted interventions that enhance such a process could reduce PIM use and related harm.


Assuntos
Demência , Lista de Medicamentos Potencialmente Inapropriados , Idoso , Idoso de 80 Anos ou mais , Demência/tratamento farmacológico , Demência/epidemiologia , Feminino , Hospitalização , Hospitais , Humanos , Prescrição Inadequada , Masculino , Estudos Prospectivos
7.
Biophys J ; 116(10): 1918-1930, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31060812

RESUMO

Fluorescent proteins (FPs) have revolutionized cell biology by allowing genetic tagging of specific proteins inside living cells. In conjunction with Förster's resonance energy transfer (FRET) measurements, FP-tagged proteins can be used to study protein-protein interactions and estimate distances between tagged proteins. FRET is mediated by weak Coulombic dipole-dipole coupling of donor and acceptor fluorophores that behave independently, with energy hopping discretely and incoherently between fluorophores. Stronger dipole-dipole coupling can mediate excitonic coupling in which excitation energy is distributed near instantaneously between coherently interacting excited states that behave as a single quantum entity. The interpretation of FP energy transfer measurements to estimate separation often assumes that donors and acceptors are very weakly coupled and therefore use a FRET mechanism. This assumption is considered reasonable as close fluorophore proximity, typically associated with strong excitonic coupling, is limited by the FP ß-barrel structure. Furthermore, physiological temperatures promote rapid vibrational dephasing associated with a rapid decoherence of fluorophore-excited states. Recently, FP dephasing times that are 50 times slower than traditional organic fluorophores have been measured, raising the possibility that evolution has shaped FPs to allow stronger than expected coupling under physiological conditions. In this study, we test if excitonic coupling between FPs is possible at physiological temperatures. FRET and excitonic coupling can be distinguished by monitoring spectral changes associated with fluorophore dimerization. The weak coupling mediating FRET should not cause a change in fluorophore absorption, whereas strong excitonic coupling causes Davydov splitting. Circular dichroism spectroscopy revealed Davydov splitting when the yellow FP VenusA206 dimerizes, and a novel approach combining photon antibunching and fluorescence correlation spectroscopy was used to confirm that the two fluorophores in a VenusA206 homodimer behave as a single-photon emitter. We conclude that excitonic coupling between VenusA206 fluorophores is possible at physiological temperatures.


Assuntos
Proteínas Luminescentes/química , Multimerização Proteica , Temperatura , Células HEK293 , Humanos , Modelos Moleculares , Estrutura Quaternária de Proteína
8.
Environ Sci Technol ; 53(23): 13720-13731, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31697487

RESUMO

The formation of water-stable aggregates in finely textured and polymineral magnetite Fe ore tailings is one of the critical processes in eco-engineering tailings into soil-like substrates as a new way to rehabilitate the tailings. Organic matter (OM) amendment and plant colonization are considered to be effective in enhancing water-stable aggregation, but the underlying mechanisms have not yet been elucidated. The present study aimed to characterize detailed changes in physicochemistry, Fe-bearing mineralogy, and organo-mineral interactions in magnetite Fe ore tailings subject to the combined treatments of OM amendment and plant colonization, by employing various microspectroscopic methods, including synchrotron-based X-ray absorption fine structure spectroscopy and nanoscale secondary ion mass spectroscopy. The results indicated that OM amendment and plant colonization neutralized the tailings' alkaline pH and facilitated water-stable aggregate formation. The resultant aggregates were consequences of ligand-promoted bioweathering of primary Fe-bearing minerals (mainly biotite-like minerals) and the formation of secondary Fe-rich mineral gels. Especially, the sequestration of OM (rich in carboxyl, aromatic, and/or carbonyl C) by Fe-rich minerals via ligand-exchange and/or hydrophobic interactions contributed to the aggregation. These findings have uncovered the processes and mechanisms of water-stable aggregate formation driven by OM amendment and plant colonization in alkaline Fe ore tailings, thus providing important basis for eco-engineered pedogenesis in the tailings.


Assuntos
Sequestro de Carbono , Óxido Ferroso-Férrico , Minerais , Solo , Água
9.
Int J Geriatr Psychiatry ; 34(10): 1498-1505, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31173395

RESUMO

OBJECTIVE: To investigate the prevalence of potentially inappropriate prescribing (PIP) using the Screening Tool of Older Person's Prescriptions (STOPP) criteria in people with dementia compared with people without dementia. METHODS: A retrospective cohort study was conducted using the Pharmaceutical Benefits Scheme 10% sample of pharmacy claims. People with dementia were defined as those dispensed a medicine for dementia (cholinesterase inhibitors, memantine, or risperidone for behavioural and psychological symptoms of dementia) between 1 January 2005 and 31 December 2015, aged 65 years or older at 1 January 2016 and alive at the end of 2016. An age- and gender-matched comparison cohort of people not dispensed medicines for dementia was identified. PIP prevalence was determined between 1 January 2016 and 31 December 2016. RESULTS: In total, 8280 people dispensed medicines for dementia and 41 400 comparisons not dispensed medicines for dementia were included: 63% were female and the median age was 82 years. PIP prevalence was 79% among people with dementia compared with 70% among the comparison group (P < .0001). Use of anticholinergics, long-term use of high-dose proton pump inhibitors, and use of benzodiazepines were the most common instances of PIP in people with dementia. After adjustments for age, gender, comorbidity, and number of prescribers, people with dementia were more likely to be exposed to PIP than comparisons (adjusted OR 1.44, 95% CI, 1.35-1.53, P < .0001). CONCLUSIONS: PIP was more common in people dispensed medicines for dementia than comparisons. These results highlight the need for effective interventions to optimize prescribing in people with dementia.


Assuntos
Demência/tratamento farmacológico , Prescrição Inadequada/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Benzodiazepinas/uso terapêutico , Antagonistas Colinérgicos/uso terapêutico , Comorbidade , Feminino , Humanos , Masculino , Inibidores da Bomba de Prótons/uso terapêutico , Estudos Retrospectivos
11.
Langmuir ; 34(23): 6955-6962, 2018 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-29757650

RESUMO

Current analytical models for sessile droplet evaporation do not consider the nonuniform temperature field within the droplet and can overpredict the evaporation by 20%. This deviation can be attributed to a significant temperature drop due to the release of the latent heat of evaporation along the air-liquid interface. We report, for the first time, an analytical solution of the sessile droplet evaporation coupled with this interfacial cooling effect. The two-way coupling model of the quasi-steady thermal diffusion within the droplet and the quasi-steady diffusion-controlled droplet evaporation is conveniently solved in the toroidal coordinate system by applying the method of separation of variables. Our new analytical model for the coupled vapor concentration and temperature fields is in the closed form and is applicable for a full range of spherical-cap shape droplets of different contact angles and types of fluids. Our analytical results are uniquely quantified by a dimensionless evaporative cooling number Eo whose magnitude is determined only by the thermophysical properties of the liquid and the atmosphere. Accordingly, the larger the magnitude of Eo, the more significant the effect of the evaporative cooling, which results in stronger suppression on the evaporation rate. The classical isothermal model is recovered if the temperature gradient along the air-liquid interface is negligible ( Eo = 0). For substrates with very high thermal conductivities (isothermal substrates), our analytical model predicts a reversal of temperature gradient along the droplet-free surface at a contact angle of 119°. Our findings pose interesting challenges but also guidance for experimental investigations.

12.
BMC Health Serv Res ; 18(1): 587, 2018 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-30055601

RESUMO

BACKGROUND: Results from a previous study showed that 40 to 60% of the price of off-patent medicines in Vietnam was typically spent to induce prescribers to use the medicines, and to persuade procurement officers within hospitals to buy them. In this article we examine how and why inducements were paid by the pharmaceutical industry to health care providers in Vietnam. METHODS: We use a theoretically informed analysis to understand pharmaceutical companies' account of giving inducements and prescribers' account of taking them, elicited through in-depth interviews. RESULTS: Analysis of the emergent concepts derived from our qualitative data led to viewing the constructs from the theoretical framework of opportunities; pressures; and rationalization within a hierarchy of systemic factors and individual factors. Economic survival pressures in an imperfectly competitive market reportedly encouraged pharmaceutical companies and prescribers to be linked financially. Although individual factors such as professional ethics and personal values influenced doctors' responses to corrupt practices, entrenched systemic issues, including lack of transparency, accountability, poor enforcement of legislation and prevalence of corruption emerged as important factors supporting corrupt practice or even making it very difficult for individuals to opt out of corrupt practices. CONCLUSIONS: Our theoretically informed analysis of inducements provides an in-depth understanding of an angle of corruption in Vietnam's health sector, showing the need for multifaceted strategies in the fight against corruption in the health sector. Remedial strategies need to address both systemic and individual factors including interventions to relieve dependencies for survival of health care services on the corrupt system.


Assuntos
Indústria Farmacêutica/economia , Prescrições de Medicamentos/economia , Motivação , Crime/economia , Custos de Medicamentos , Medicamentos Genéricos/economia , Setor de Assistência à Saúde/economia , Pessoal de Saúde/economia , Humanos , Médicos , Padrões de Prática Médica/economia , Medicamentos sob Prescrição/economia , Responsabilidade Social , Vietnã
13.
Biophys J ; 112(6): 1270-1281, 2017 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-28355553

RESUMO

While kinases are typically composed of one or two subunits, calcium-calmodulin (CaM)-dependent protein kinase II (CaMKII) is composed of 8-14 subunits arranged as pairs around a central core. It is not clear if the CaMKII holoenzyme functions as an assembly of independent subunits, as catalytic pairs, or as a single unit. One strategy to address this question is to genetically engineer monomeric and dimeric CaMKII and evaluate how their activity compares to the wild-type (WT) holoenzyme. Here a technique that combines fluorescence correlation spectroscopy and homo-FRET analysis was used to characterize assembly mutants of Venus-tagged CaMKIIα to identify a dimeric CaMKII. Spectroscopy was then used to compare how holoenzyme structure and function changes in response to activation with CaM in the dimeric mutant, WT-holoenzyme, and a monomeric CaMKII oligomerization-domain deletion mutant control. CaM triggered an increase in hydrodynamic volume in both WT and dimeric CaMKII without altering subunit stoichiometry or the net homo-FRET between Venus-tagged catalytic domains. Biochemical analysis revealed that the dimeric mutant also functioned like WT holoenzyme in terms of its kinase activity with an exogenous substrate, and for endogenous T286 autophosphorylation. We conclude that the fundamental functional units of CaMKII holoenzyme are paired catalytic-domains.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/química , Transferência Ressonante de Energia de Fluorescência , Multimerização Proteica , Células HEK293 , Holoenzimas/química , Humanos , Estrutura Quaternária de Proteína
14.
BMC Geriatr ; 17(1): 298, 2017 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-29284416

RESUMO

BACKGROUND: Medications are frequently reported as both predisposing factors and inducers of delirium. This review evaluated the available evidence and determined the magnitude of risk of postoperative delirium associated with preoperative medication use. METHODS: A systematic search in Medline and EMBASE was conducted using MeSH terms and keywords for postoperative delirium and medication. Studies which included patients 18 years and older who underwent major surgery were included. The methodological quality of included studies was assessed independently by two authors using the Newcastle-Ottawa quality assessment scale for cohort studies. RESULTS: Twenty-nine studies; 25 prospective cohort, three retrospective cohort and one post hoc analysis of RCT data were included. Only four specifically aimed to assess medicines as an independent predictor of delirium, all other studies included medicines among a number of potential predictors of delirium. Of the studies specifically testing the association with a medication class, preoperative use of beta-blockers (OR = 2.06[1.18-3.60]) in vascular surgery and benzodiazepines RR 2.10 (1.23-3.59) prior to orthopedic surgery were significant. However, evidence is from single studies only. Where medicines were included as one possible factor among many, hypnotics had a similar risk estimate to the benzodiazepine study, with one significant and one non-significant result. Nifedipine use prior to cardiac surgery was found to be significantly associated with delirium. The non-specific grouping of psychoactive medication use preoperatively was generally higher with an associated two-to-seven-fold higher risk of postoperative delirium, while only two studies included narcotics without other agents, with one significant and one non-significant result. CONCLUSIONS: There was a limited number of high quality studies in the literature quantifying the direct association between preoperative medication use and postsurgical delirium. More studies are required to evaluate the association of specific preoperative medications on the risk of postoperative delirium so that comprehensive guidelines for medicine use prior to surgery can be developed to aid delirium prevention. TRIAL REGISTRATION: This systematic review has been registered on PROSPERO International prospective register of systematic reviews (Registration number: CRD42016051245 ).


Assuntos
Benzodiazepinas/uso terapêutico , Delírio , Complicações Pós-Operatórias , Pré-Medicação , Cuidados Pré-Operatórios , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Idoso , Delírio/diagnóstico , Delírio/etiologia , Delírio/prevenção & controle , Humanos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Pré-Medicação/efeitos adversos , Pré-Medicação/métodos , Cuidados Pré-Operatórios/efeitos adversos , Cuidados Pré-Operatórios/métodos , Risco Ajustado/métodos , Procedimentos Cirúrgicos Operatórios/métodos
15.
Environ Geochem Health ; 39(2): 403-415, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27619818

RESUMO

A wide range of waste biomass/waste wood feedstocks abundantly available at mine sites provide the opportunity to produce biochars for cost-effective improvement of mine tailings and contaminated land at metal mines. In the present study, soft- and hardwood biochars derived from pine and jarrah woods at high temperature (700 °C) were characterized for their physiochemical properties including chemical components, electrical conductivity, pH, zeta potential, cation-exchange capacity (CEC), alkalinity, BET surface area and surface morphology. Evaluating and comparing these characteristics with available data from the literature have affirmed the strong dictation of precursor type on the physiochemical properties of the biochars. The pine and jarrah wood feedstocks are mainly different in their proportions of cellulose, hemicellulose and lignin, resulting in biochars with heterogeneous physiochemical properties. The hardwood jarrah biochar exhibits much higher microporosity, alkalinity and electrostatic capacity than the softwood pine. Correlation analysis and principal component analysis also show a good correlation between CEC-BET-alkalinity, and alkalinity-ash content. These comprehensive characterization and analysis results on biochars' properties from feedstocks of hardwood (from forest land clearance at mine construction) and waste pine wood (from mining operations) will provide a good guide for tailoring biochar functionalities for remediating metal mine tailings. The relatively inert high-temperature biochars can be stored for a long term at mine closure after decades of operations.


Assuntos
Carvão Vegetal/química , Eucalyptus , Pinus , Madeira/química , Biomassa , Condutividade Elétrica , Recuperação e Remediação Ambiental , Concentração de Íons de Hidrogênio , Especificidade da Espécie , Propriedades de Superfície , Temperatura
16.
Biophys J ; 108(9): 2158-70, 2015 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-25954874

RESUMO

Between 8 to 14 calcium-calmodulin (Ca(2+)/CaM) dependent protein kinase-II (CaMKII) subunits form a complex that modulates synaptic activity. In living cells, the autoinhibited holoenzyme is organized as catalytic-domain pairs distributed around a central oligomerization-domain core. The functional significance of catalytic-domain pairing is not known. In a provocative model, catalytic-domain pairing was hypothesized to prevent ATP access to catalytic sites. If correct, kinase-activity would require catalytic-domain pair separation. Simultaneous homo-FRET and fluorescence correlation spectroscopy was used to detect structural changes correlated with kinase activation under physiological conditions. Saturating Ca(2+)/CaM triggered Threonine-286 autophosphorylation and a large increase in CaMKII holoenzyme hydrodynamic volume without any appreciable change in catalytic-domain pair proximity or subunit stoichiometry. An alternative hypothesis is that two appropriately positioned Threonine-286 interaction-sites (T-sites), each located on the catalytic-domain of a pair, are required for holoenzyme interactions with target proteins. Addition of a T-site ligand, in the presence of Ca(2+)/CaM, elicited a large decrease in catalytic-domain homo-FRET, which was blocked by mutating the T-site (I205K). Apparently catalytic-domain pairing is altered to allow T-site interactions.


Assuntos
Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/química , Domínio Catalítico , Sequência de Aminoácidos , Cálcio/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Células HEK293 , Holoenzimas/química , Holoenzimas/metabolismo , Humanos , Dados de Sequência Molecular , Ligação Proteica , Treonina/química , Treonina/metabolismo
17.
Ann Plast Surg ; 74(3): 300-3, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24322646

RESUMO

Closed traumatic rupture of the thenar muscles is an unusual and rare injury. Traumatic musculotendinous injuries in the hand and wrist occur primarily from penetrating trauma. Only 2 such cases were identified in medical literature. We report a case of closed traumatic rupture of the thenar muscles in an otherwise healthy 33-year-old female nurse who sustained a hyperabduction injury of her right thumb and wrist during a daily occupational routine, resulting in complete avulsion of the right abductor pollicis brevis and opponens pollicis from their origins. After declining initial surgical management, the patient subsequently returned 6 months later reporting continued pain, paresthesias, and thenar deformation, and requested surgical intervention. On examination, she continued to exhibit weakness of thumb abduction and mild weakness with opposition. She was again offered an open carpal tunnel release with exploration of the thenar eminence and possible tendon transfer, although she adamantly refused any tendon transfer. An open right carpal tunnel release was performed with exploration and direct muscle repair through a lateral thenar incision. Primary muscular reattachment was accomplished by suturing the abductor pollicis brevis and opponens pollicis to the flexor retinaculum and the trapezium. Functional results 15 months after surgery were satisfactory with improvements in abduction and opposition of the thumb and restoration of the thenar contour. The chosen surgical technique for repair resulted in good functional outcome, while avoiding the need for tendon transfer.


Assuntos
Traumatismos da Mão/cirurgia , Músculo Esquelético/lesões , Enfermagem , Traumatismos Ocupacionais/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Adulto , Feminino , Traumatismos da Mão/diagnóstico , Humanos , Músculo Esquelético/cirurgia , Traumatismos Ocupacionais/diagnóstico
18.
Opt Lett ; 39(8): 2419-22, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24979008

RESUMO

A new microwave photonic instantaneous frequency measurement system that can simultaneously measure multiple-frequency signals while achieving very high resolution and wide frequency measurement range is presented. It is based on the frequency-to-time mapping technique implemented using a frequency shifting recirculating delay line loop and a narrowband optical filter realized by the in-fiber stimulated Brillouin scattering effect. Experimental results demonstrate the realization of a multiple-frequency measurement capability over a frequency range of 0.1-20 GHz that can be extended to 90 GHz, and with a measurement resolution of 250 MHz.

19.
Langmuir ; 30(22): 6544-7, 2014 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-24873776

RESUMO

The transient shape and volume of evaporating sessile droplets are critical to our understanding and prediction of deposits left over on the solid surface after droplet evaporation. The 2/3 power law of scaling, (V/Vo)(ß) = 1 - t/tf with ß = 2/3, has been widely used. The 1/1 power law of scaling with ß = 1 was also obtained for vanishingly small contact angles. Here we show that ß significantly deviates from 2/3 and 1 when the droplet base is pinned: ß depends on both initial and transient contact angles. The 1/1 power law presents the upper limit of ß = 1, while ß = 2/3 is the lower limit if contact angles are smaller than 148°. Unexpectedly, ß can be smaller than 2/3 if contact angles are larger than 148°. We also present a semianalytical approximation for ß as a function of the initial contact angle.

20.
Gerontologist ; 64(7)2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38712983

RESUMO

BACKGROUND AND OBJECTIVES: There is a high prevalence of frailty amongst older patients in hospital settings. Frailty guidelines exist but implementation to date has been challenging. Understanding health professional attitudes, knowledge, and beliefs about frailty is critical in understanding barriers and enablers to guideline implementation, and the aim of this study was to understand these in rehabilitation multidisciplinary teams in hospital settings. RESEARCH DESIGN AND METHODS: Twenty-three semistructured interviews were conducted with health professionals working in multidisciplinary teams on geriatric and rehabilitation wards in Adelaide and Sydney, Australia. Interviews were audio recorded, transcribed, and coded by 2 researchers. A codebook was created and interviews were recoded and applied to the Framework Method of thematic analysis. RESULTS: Three domains were developed: diagnosing frailty, communicating about frailty, and managing frailty. Within these domains, 8 themes were identified: (1) diagnosing frailty has questionable benefits, (2) clinicians don't use frailty screening tools, (3) frailty can be diagnosed on appearance and history, (4) frailty has a stigma, (5) clinicians don't use the word "frail" with patients, (6) frailty isn't always reversible, (7) there is a lack of continuity of care after acute admission, and (8) the community setting lacks resources. DISCUSSION AND IMPLICATIONS: Implementation of frailty guidelines will remain challenging while staff avoid using the term "frail," don't perceive benefit of using screening tools, and focus on the individual aspects of frailty rather than the syndrome holistically. Clinical champions and education about frailty identification, reversibility, management, and communication techniques may improve the implementation of frailty guidelines in hospitals.


Assuntos
Atitude do Pessoal de Saúde , Idoso Fragilizado , Fragilidade , Pesquisa Qualitativa , Humanos , Masculino , Feminino , Idoso , Austrália , Fragilidade/diagnóstico , Idoso Fragilizado/psicologia , Pessoal de Saúde/psicologia , Avaliação Geriátrica/métodos , Conhecimentos, Atitudes e Prática em Saúde , Pessoa de Meia-Idade , Entrevistas como Assunto , Adulto
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