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1.
Inorg Chem ; 62(30): 11876-11886, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37449705

RESUMO

New solid electrolytes are crucial for the development of all-solid-state lithium batteries with advantages in safety and energy densities over current liquid electrolyte systems. While some of the best solid-state Li+-ion conductors are based on sulfides, their air sensitivity makes them less commercially attractive, and attention is refocusing on air-stable oxide-based systems. Among these, the LISICON-structured systems, such as Li2+2xZn1-xGeO4 and Li3+xV1-xGexO4, have been relatively well studied. However, other systems such as the Li4GeO4-Li2MoO4 system, which also show LISICON-type structures, have been relatively little explored. In this work, the Li4-2xGe1-xMoxO4 solid solution is investigated systematically, including the solid solution limit, structural stability, local structure, and the corresponding electrical behavior. It is found that a γ-LISICON structured solution is formed in the range of 0.1 ≤ x < 0.4, differing in structure from the two end members, Li4GeO4 and Li2MoO4. With increasing Mo content, the ß-phase becomes increasingly more stable than the γ-phase, and at x = 0.5, a pure ß-phase (ß-Li3Ge0.5Mo0.5O4) is readily isolated. The structure of this previously unknown compound is presented, along with details of the defect structure of Li3.6Ge0.8Mo0.2O4 (x = 0.2) based on neutron diffraction data. Two basic types of defects are identified in Li3.6Ge0.8Mo0.2O4 involving interstitial Li+-ions in octahedral sites, with evidence for these coming together to form larger defect clusters. The x = 0.2 composition shows the highest conductivity of the series, with values of 1.11 × 10-7 S cm-1 at room temperature rising to 5.02 × 10-3 S cm-1 at 250 °C.

2.
Glob Chang Biol ; 27(21): 5514-5531, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34486773

RESUMO

Marine spatial planning that addresses ocean climate-driven change ('climate-smart MSP') is a global aspiration to support economic growth, food security and ecosystem sustainability. Ocean climate change ('CC') modelling may become a key decision-support tool for MSP, but traditional modelling analysis and communication challenges prevent their broad uptake. We employed MSP-specific ocean climate modelling analyses to inform a real-life MSP process; addressing how nature conservation and fisheries could be adapted to CC. We found that the currently planned distribution of these activities may become unsustainable during the policy's implementation due to CC, leading to a shortfall in its sustainability and blue growth targets. Significant, climate-driven ecosystem-level shifts in ocean components underpinning designated sites and fishing activity were estimated, reflecting different magnitudes of shifts in benthic versus pelagic, and inshore versus offshore habitats. Supporting adaptation, we then identified: CC refugia (areas where the ecosystem remains within the boundaries of its present state); CC hotspots (where climate drives the ecosystem towards a new state, inconsistent with each sectors' present use distribution); and for the first time, identified bright spots (areas where oceanographic processes drive range expansion opportunities that may support sustainable growth in the medium term). We thus create the means to: identify where sector-relevant ecosystem change is attributable to CC; incorporate resilient delivery of conservation and sustainable ecosystem management aims into MSP; and to harness opportunities for blue growth where they exist. Capturing CC bright spots alongside refugia within protected areas may present important opportunities to meet sustainability targets while helping support the fishing sector in a changing climate. By capitalizing on the natural distribution of climate resilience within ocean ecosystems, such climate-adaptive spatial management strategies could be seen as nature-based solutions to limit the impact of CC on ocean ecosystems and dependent blue economy sectors, paving the way for climate-smart MSP.


Assuntos
Mudança Climática , Ecossistema , Adaptação Fisiológica , Conservação dos Recursos Naturais , Pesqueiros , Oceanografia
3.
Pain Med ; 21(11): 2903-2912, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32719856

RESUMO

OBJECTIVES: Objectively measuring pain sensitivity has not been easy in primary care clinics. A sphygmomanometer test (a sensory test that measures an individual's nociceptive response to pressure using a standard blood pressure cuff) has recently been established to test pain sensitivity. Here, we examined the feasibility of using the sphygmomanometer test with chronic pain patients. DESIGN: Population, observational study. SETTINGS: A community hospital multidisciplinary Pain Center and a private nonprofit university. SUBJECTS: Healthy controls and chronic pain patients were recruited. METHODS: All subjects underwent four pain sensitivity tests: a pressure algometer test, a cold pressure test, a heat sensitivity test, and a sphygmomanometer test. Participants then completed four established surveys for evaluating depression (Patient Health Questionnaire-9), anxiety (General Anxiety Disorder-7), fatigue (Fatigue Severity Scale), and pain catastrophizing (Pain Catastrophizing Scale). RESULTS: Although pain patients had significantly higher levels of depression, anxiety, fatigue, and pain catastrophizing, as well as reported pain scores, no significant differences in pain sensitivity were detected via any of the pain sensitivity tests. In the control but not the patient group, results from all pain sensitivity tests including the sphygmomanometer test were significantly correlated with each other. Unlike other pain sensitivity tests, the sphygmomanometer test did not correlate with measures of depression, anxiety, fatigue, or pain catastrophizing characteristics. CONCLUSIONS: Our results indicate the unique characteristics of the sphygmomanometer test as a pain sensitivity test, particularly when utilized for individuals with chronic pain. Multiple pain sensitivity tests that assess various sensory modalities are needed to evaluate pain sensitivities in chronic pain patients.


Assuntos
Dor Crônica , Ansiedade/diagnóstico , Catastrofização , Dor Crônica/diagnóstico , Depressão/diagnóstico , Humanos , Medição da Dor , Limiar da Dor , Esfigmomanômetros , Inquéritos e Questionários
4.
BMC Med Inform Decis Mak ; 20(1): 267, 2020 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-33069228

RESUMO

BACKGROUND: Chronic pain has emerged as a disease in itself, affecting a growing number of people. Effective patient-provider communication is central to good pain management because pain can only be understood from the patient's perspective. We aimed to develop a user-centered tool to improve patient-provider communication about chronic pain and assess its feasibility in real-world settings in preparation for further evaluation and distribution. METHODS: To identify and prioritize patient treatment goals for chronic pain, strategies to improve patient-provider communication about chronic pain, and facilitate implementation of the tool, we conducted nominal group technique meetings and card sorting with patients with chronic pain and experienced providers (n = 12). These findings informed the design of the PainAPP tool. Usability and beta-testing with patients (n = 38) and their providers refined the tool and assessed its feasibility, acceptability, and preliminary impact. RESULTS: Formative work revealed that patients felt neither respected nor trusted by their providers and focused on transforming providers' negative attitudes towards them, whereas providers focused on gathering patient information. PainAPP incorporated areas prioritized by patients and providers: assessing patient treatment goals and preferences, functional abilities and pain, and providing patients tailored education and an overall summary that patients can share with providers. Beta-testing involved 38 patients and their providers. Half of PainAPP users shared their summaries with their providers. Patients rated PainAPP highly in all areas. All users would recommend it to others with chronic pain; nearly all trusted the information and said it helped them think about my treatment goals (94%), understand my chronic pain (82%), make the most of my next doctor's visit (82%), and not want to use opioids (73%). Beta-testing revealed challenges delivering the tool and summary report to patients and providers in a timely manner and obtaining provider feedback. CONCLUSIONS: PainAPP appears feasible for use, but further adaptation and testing is needed to assess its impact on patients and providers. TRIAL REGISTRATION: This study was approved by the University of New England Independent Review Board for the Protection of Human Subjects in Research (012616-019) and was registered with ClinicalTrials.gov (protocol ID: NCT03425266) prior to enrollment. The trial was prospectively registered and was approved on February 7, 2018.


Assuntos
Dor Crônica/diagnóstico , Comunicação , Tomada de Decisão Compartilhada , Sistemas de Apoio a Decisões Clínicas/normas , Manejo da Dor/métodos , Relações Profissional-Paciente , Dor Crônica/terapia , Inglaterra , Estudos de Viabilidade , Feminino , Humanos , Masculino
5.
Inorg Chem ; 58(1): 715-723, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30525524

RESUMO

On the orthosilicate join, Li4SiO4-Mn2SiO4, the new phase Li3Mn0.5SiO4 and a range of Li2+2 xMn1- xSiO4 solid solutions with ∼0.76 ≤ x ≤ 1 have been prepared by high-temperature, solid-state reaction and characterized. Li3Mn0.5SiO4 is orthorhombic, space group Pnma, with a = 10.722(3) Å, b = 6.239(2) Å, and c = 5.052(3) Å. A combined analysis of X-ray and neutron powder diffraction data show that its structure is derived from the γII tetrahedral structural family typified by Li3PO4, but with additional Li+ in partially occupied, distorted octahedral sites. These octahedral sites are linked by a combination of edge- and face-sharing, similar to that in the nickel arsenide structure and their partial occupancy is responsible for an Li+ ion conductivity of, for example, ∼ 1 × 10-8 S cm-1 at 60 °C, with activation energy 0.93(1) eV, which is many orders of magnitude higher than that of Li2MnSiO4.

6.
Inorg Chem ; 57(12): 7025-7035, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29812935

RESUMO

This paper describes a study of the system MoO3-Nd2O3 using a combination of X-ray powder diffraction (XRD), neutron powder diffraction (NPD), thermogravimetric analysis (TGA), and ac impedance spectroscopy (IS). A phase-pure material is observed at a composition of 45.5 mol % Nd2O3, which corresponds to an ideal stoichiometry of Nd5Mo3O16.5. XRD and NPD show that the crystal structure is a superstructure of the fluorite arrangement, with long-range ordering of the two cation species leading to a doubled unit cell parameter. The sample is found to be significantly oxygen deficient, i.e. Nd5Mo3O15.63(4), when it is prepared by a solid-state reaction at 1473 K in air. TGA measurements indicate that the sample loses only minimal mass on heating to 1273 K in O2. IS studies of the mean conductivity under different atmospheres show that the sample is a mixed conductor between ambient temperature and 873 K, with a dominant electronic component at higher temperatures, as demonstrated by measurements under inert atmosphere. NPD measurements indicate that the anion vacancies are preferentially located on the O2 sites, while studies of the temperature dependence performed under an O2 atmosphere to 1273 K show significantly anisotropic thermal parameters of the anions. Together with analysis of the total neutron scattering data, this supports a model of oxygen ions hopping between O2 positions, with a vacancy, rather than interstitial, mechanism for the anion diffusion.

7.
Inorg Chem ; 56(6): 3657-3662, 2017 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-28263582

RESUMO

In situ neutron diffraction was used to characterize the effect of temperature on the crystal structure of LiNiPO4. LiNiPO4 adopts an ordered olivine structure at room temperature, but, with increasing temperature, this work shows that a significant amount of Li and Ni cation exchange occurs, for example, ∼15% at 900 °C. The antisite disorder is detected by residual nuclear densities on the M1 and M2 octahedral sites in the olivine structure using difference Fourier maps and by changes in cation site occupancies, lattice parameters, and mean ⟨M-O⟩ bond distances. The antisite disorder is also responsible for chemical expansion of the crystal lattice in addition to thermal expansion. Antisite defect formation at high temperature and its reversibility on cooling can be understood as an entropically driven feature of the crystal structure of LiNiPO4. The lithium ion diffusion pathway, that follows a curved trajectory along the b axis in the olivine structure, is, therefore, susceptible to be blocked if synthesis conditions are not carefully controlled and should also be influenced by the chemically expanded lattice of the disordered structure if this is preserved to ambient temperature by rapid cooling.

8.
Phys Chem Chem Phys ; 18(34): 24070-80, 2016 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-27526388

RESUMO

This work presents a structural investigation of La2-xNdxCe2O7 (x = 0.0, 0.5, 1.0, 1.5, 2.0) using X-ray powder diffraction and total scattering neutron powder diffraction, analysed using Rietveld and the reverse Monte Carlo method (RMC). Ab initio molecular dynamics (MD) modelling is also performed for further investigations of the local order. The main intensities in the neutron diffraction data for the La2-xNdxCe2O7 series correspond to the fluorite structure. However, additional C-type superlattice peaks are visible for x > 0 and increase in intensity with increasing x. The Nd-containing compositions (x > 0) are best fitted with Rietveld analysis by using a combination of oxygen deficient fluorite and oxygen excess C-type structures. No indications of cation order are found in the RMC or Rietveld analysis, and the absence of cation order is supported by the MD modelling. We argue that the superlattice peaks originate from oxygen vacancy ordering and associated shift in the cation position away from the ideal fluorite site similar to that in the C-type structure, which is seen from the Rietveld refinements and the observed ordering in the MD modelling. The vacancies favour alignments in the 〈110〉, 〈111〉 and especially the 〈210〉 direction. Moreover, we find that such ordering might also be found to a small extent in La2Ce2O7, explaining the discernible modulated background between the fluorite peaks. The observed overlap of the main Bragg peaks between the fluorite and C-type phase supports the co-existence of vacancy ordered and more disordered domains. This is further supported by the observed similarity of the radial distribution functions as modelled with MD. The increase in long range oxygen vacancy order with increasing Nd-content in La2-xNdxCe2O7 corresponds well with the lower oxide ion conductivity in Nd2Ce2O7 compared to La2Ce2O7 reported earlier.

9.
Chem Mater ; 35(1): 189-206, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36644215

RESUMO

The BIMEVOXes are among the best oxide ion conductors at low and intermediate temperatures. Their high conductivity is associated with local defect structure. In this work, the local structures of two BIMEVOX compositions, Bi2V0.9Ge0.1O5.45 and Bi2V0.95Sn0.05O5.475, are examined using total neutron and X-ray scattering methods, with both compositions exhibiting the ordered α-phase at 25 °C and the disordered γ-phase at 700 °C. While the diffraction data for the α-phase do not allow for the polar (C2) and nonpolar (C2/m) structures to be readily distinguished, measurements of dielectric permittivity suggest the α-phase is weakly ferroelectric in character, consistent with calculations of spontaneous polarization based on a combination of density functional calculations and machine learning methodology. Reverse Monte Carlo (RMC) analysis of total scattering data reveals Ge preferentially adopts tetrahedral geometry at both temperatures, while Sn is found to predominantly adopt octahedral coordination in the α-phase and tetrahedral coordination in the γ-phase. In all cases, V polyhedra are found to consist of tetrahedral, pentacoordinate, and octahedral geometries, as also predicted by the crystallographic analysis and confirmed by 51V solid state NMR spectroscopy. Although similar long-range structures are observed at room temperature, the oxide ion vacancy distributions were found to be quite different between the two studied compositions, with a nonrandom deficiency in vacancy pairs in the second-nearest shell along the ⟨100⟩ tetragonal direction for BIGEVOX10, compared with a long-distance (>8.0 Å) ordering of equatorial vacancies for BISNVOX05. This is attributed to the differences in the preferred coordination geometries of the substituent cations in the two systems. Impedance spectroscopy measurements reveal both compositions show high conductivity in the order of 10-1 S cm-1 at 600 °C.

10.
J Phys Condens Matter ; 34(32)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35609585

RESUMO

We revisit the pressure-induced order-disorder transition between phases II and IV in ammonium bromide-d4using neutron diffraction measurements to characterise both the average and local structures. We identify a very sluggish transition that does not proceed to full conversion and local structure correlations indicate a slight preference for ammonium cation ordering along ⟨110⟩ crystallographic directions, as pressure is increased. Simultaneous cooling below ambient temperature appears to facilitate the pressure-induced transition. Variable-temperature, ambient-pressure measurements across the IV → III → II transitions show slower conversion than previously observed, and that phase III exhibits metastability above ambient temperature.

11.
PLoS One ; 17(6): e0269790, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35731823

RESUMO

Tourism and outdoor leisure is an important economic sector for many countries, and has a substantial reliance on natural capital. Natural capital may be the primary purpose for tourism, or it may be a secondary factor, where the choice of location for a leisure activity is influenced by natural capital. Typically, when valuing tourism and outdoor leisure, all expenditure associated with the activity is assigned to the ecosystem it occurs in. However, this value illustrates the dependency on natural capital, rather than the contribution of natural capital. In natural capital accounting, a major challenge is to separately identify the contribution of natural capital from that of other forms of capital. In this study we develop a transparent and repeatable method that is able to attribute the contribution of natural capital (here defined as ecosystems) to the output of multiple tourism and outdoor leisure activities. Using national statistics from Great Britain, we calculate the natural capital contribution to tourism spend by activity at a national and regional scale, and for a case study map and value the contributing ecosystems. We estimated that, out of a total £36 billion spent on tourism and leisure activities in 2017, £22.5 billion was attributable to natural capital. This equates to 0.9% of the UK GDP. The Gross Value Added component of this attributable was £10.5 billion, equivalent to 0.4% of the UK GDP. Regions with the highest natural capital contribution in Great Britain were Scotland and Wales, with the lowest being Greater London and the West Midlands in England. For the case study, the ecosystems with the greatest contribution to terrestrial activities were marine and enclosed farmland. These methods can be applied worldwide for anywhere with aggregate economic statistics on expenditure associated with tourism and outdoor leisure, with the aid of open source GIS datasets.


Assuntos
Contabilidade , Ecossistema , Fazendas , Atividades de Lazer , Turismo
12.
Med Sci Educ ; 31(2): 479-488, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34457905

RESUMO

OBJECTIVE: To address the need for increased and more effective medical education regarding chronic pain and pain management, an inter-professional (IP) training program in the form of a supervised student IP pain clinic was implemented in 2016. In the current study, we evaluated its feasibility and effectiveness in improving health care professional students' skills in (1) managing chronic pain and (2) working in an IP team. METHODS: From January 2016 to December 2018, we assembled 12 IP teams that included students from the following six professions at the University of New England: nursing, osteopathic medicine (OM), occupational therapy (OT), pharmacy, physical therapy (PT), and social work (SW). During this 12-week training program, each team conducted the initial evaluation, generated treatment plans, and performed follow-up examinations for its assigned patient under the supervision of a pain specialist at the Mercy Pain Center. Surveys were conducted with all participating students and patients. RESULTS: Overall, students showed significant improvement in knowledge regarding pain physiology and chronic pain management as well as attitude and perception regarding IP practice and perceived team skills. Specifically, prior to the program, nursing students showed the greatest pain-related knowledge and perceived team skills, while OT students scored the highest in attitude and perception regarding IP practice. Following the program, improvement in various measures was observed in all professions with PT students showing the most significant improvement in all areas. Surveys also indicated patients' satisfaction with their IP pain clinic experience. CONCLUSIONS: These results demonstrated the feasibility and the effectiveness of this IP training program for all participating professions.

13.
Cureus ; 12(2): e7071, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32226672

RESUMO

Introduction Emergency department (ED) patients with chronic disease are known to benefit from exercise; however, there are few studies examining the prescription of exercise in the ED. We asked, is exercise prescription in the ED feasible and effective? Methods In this pilot prospective block randomized trial, consented patients were divided into control and intervention groups. The control group received routine care. The intervention group received combined written and verbal prescriptions for moderate exercise of 150 minutes/week. Both groups were followed up by phone at two months. The primary outcome was achieving 150 minutes of exercise per week. Secondary outcomes included change in exercise and differences in reported median weekly exercise. Results Follow-up was completed for 23/28 patients (11 control; 12 intervention). Baseline reported median (with interquartile range) weekly exercise was similar between groups: control 0 (0-0) minutes, intervention 0 (0-45) minutes. There was no difference between groups for the primary outcome at two months (control 3/11; intervention 4/12, relative risk [RR] 1.33 (95% confidence interval [CI] 0.38-4.6; p=1.0). There was a significant increase in median exercise from baseline in both groups, but no difference between the groups (control 75 (10-225) minutes; intervention 120 (52.5-150) minutes; NS). A post hoc comparison of patients actually receiving intervention vs. no intervention revealed a significant increase in patients meeting the primary outcome (no intervention 0/8; intervention 7/15, RR 2.0 (95% CI 1.2-3.4); p=0.05). Conclusion The improvement seen in patients receiving the exercise prescription intervention, and the increase in reported exercise in both groups suggests that exercise prescription for ED patients may be beneficial.

14.
Orthopedics ; 43(4): 250-255, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32674176

RESUMO

Dual-mobility constructs have been shown to significantly and substantially decrease dislocations after revision total hip arthroplasty (THA). The authors have previously shown that dual-mobility (DM) constructs are cost-effective given their ability to decrease dislocations and re-revision for dislocation. The goal was to report the costs of DM and large femoral head (LFH) constructs in revision THAs from a European health care payer perspective. A Markov model was constructed to analyze the costs incurred by payers in the United Kingdom, Germany, Italy, and Spain over 3 years in revision THAs with DM or LFH constructs. Model states and probabilities were derived from prospectively collected registry data in 302 patients who underwent revision THA with a DM or 40-mm LFH construct and were then mapped to corresponding procedural reimbursement codes and tariffs for each country. Costs were weighted average national payments for reintervention procedures performed in the 3 years following revision THA. Probabilistic sensitivity analysis examined the effect of combined uncertainty across all model parameters. During a 3-year period following revision THA, reintervention rates were 9% for DM constructs and 19% for LFH constructs (P=.01). Comparing DM and LFH constructs, cumulative incremental costs over 3-years' follow-up were £428 vs £1447 in the United Kingdom, euro 451 vs euro 1272 in Germany, euro 540 vs euro 1425 in Italy, and euro 523 vs euro 1562 in Spain, respectively. At mid-term follow-up, DM constructs used in revision THAs were associated with a significantly lower risk of reintervention, which translated to lower health care payer costs compared with LFH constructs among European health care payers. [Orthopedics. 2020;43(4):250-255.].


Assuntos
Artroplastia de Quadril/economia , Artroplastia de Quadril/instrumentação , Análise Custo-Benefício , Custos de Cuidados de Saúde/estatística & dados numéricos , Prótese de Quadril/economia , Reoperação/economia , Reoperação/instrumentação , Adulto , Idoso , Europa (Continente) , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Sistema de Registros
15.
J Phys Condens Matter ; 21(21): 215401, 2009 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-21825547

RESUMO

The Zr(0.5-0.5x)Y(0.5+0.25x)Nb(0.25x)O(1.75) solid solution possesses an anion-deficient fluorite structure across the entire 0≤x≤1 range. The relationship between the disorder within the crystalline lattice and the preferred anion diffusion mechanism has been studied as a function of x, using impedance spectroscopy measurements of the ionic conductivity (σ), powder neutron diffraction studies, including analysis of the 'total' scattering to probe the nature of the short-range correlations between ions using reverse Monte Carlo (RMC) modelling, and molecular dynamics (MD) simulations using potentials derived with a strong ab initio basis. The highest total ionic conductivity (σ = 2.66 × 10(-2) Ω(-1) cm(-1) at 1473 K) is measured for the Zr(2)Y(2)O(7) (x = 0) end member, with a decrease in σ with increasing x, whilst the neutron diffraction studies show an increase in lattice disorder with x. This apparent contradiction can be understood by considering the local structural distortions around the various cation species, as determined from the RMC modelling and MD simulations. The addition of Nb(5+) and its stronger Coulomb interaction generates a more disordered local structure and enhances the mobility of some anions. However, the influence of these pentavalent cations is outweighed by the effect of the additional Y(3+) cations introduced as x increases, which effectively trap many anions and reduce the overall concentration of the mobile O(2-) species.

16.
RSC Adv ; 9(17): 9640-9653, 2019 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35520691

RESUMO

A detailed study of the defect structure in a di-substituted δ-Bi2O3 type phase, δ-Bi5PbY2O11.5, is presented. Using a combination of conventional Rietveld analysis of neutron diffraction data, reverse Monte Carlo (RMC) analysis of total neutron scattering data and ab initio molecular dynamics (MD) simulations, both average and local structures have been characterized. δ-Bi5PbY2O11.5 represents a model system for the highly conducting δ-Bi2O3 type phases, in which there is a higher nominal vacancy concentration than in the unsubstituted parent compound. Uniquely, the methodology developed in this study has afforded the opportunity to study both oxide-ion vacancy ordering as well as specific cation-cation interactions. Oxide-ion vacancies in this system have been found to show a preference for association with Pb2+ cations, with some evidence for clustering of these cations. The system shows a non-random distribution of vacancy pair alignments, with a preference for 〈100〉 ordering, the extent of which shows thermal variation. MD simulations indicate a predominance of oxide-ion jumps in the 〈100〉 direction.

17.
Heart Rhythm ; 5(2): 300-5, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18242558

RESUMO

BACKGROUND: Unexpected sudden death among apparently healthy individuals remains a daunting problem. We have previously shown that autonomic modulation of cardiac arrhythmias and autonomic markers, such as baroreflex sensitivity (BRS) and heart rate variability (HRV), carry predictive power after myocardial infarction. OBJECTIVE: We tested the hypothesis that a parameter combining BRS and HRV could predict risk for ventricular fibrillation (VF) during a first ischemic episode in otherwise healthy dogs. METHODS: In 43 fully instrumented dogs, BRS and frequency domain analysis of HRV were determined, as well as the occurrence (n = 10, high-risk) or absence (n = 33, low-risk) of VF during 2 minutes of myocardial ischemia superimposed on submaximal exercise. TARVA (Tonic and Reflex Vagal Activity), expressed in units, is the parameter resulting from the multiplication of BRS by HF/LF (an index of tonic vagal activity). RESULTS: High-risk dogs had markedly lower TARVA values, reflecting lower cardiac vagal activity, than low-risk animals (12 +/- 5 versus 56 +/- 43 units, P < .001). The area under the receiver-operator characteristic curve for TARVA was 0.96 (95% confidence interval 0.86 to 0.99); its optimal cutoff had a 100% sensitivity and a 88% specificity with positive and negative predictive values of 71% and 100%, respectively. CONCLUSION: Differences in cardiac autonomic activity, present in healthy dogs, allow prediction of arrhythmic risk during a first ischemic episode. Increased risk is associated with reduced vagal activity. If confirmed in humans, this finding would open the way to the identification of those apparently healthy subjects at risk for sudden cardiac death during their first episode of myocardial ischemia.


Assuntos
Arritmias Cardíacas/fisiopatologia , Sistema Nervoso Autônomo/fisiopatologia , Barorreflexo , Morte Súbita Cardíaca/etiologia , Frequência Cardíaca , Fibrilação Ventricular/fisiopatologia , Animais , Arritmias Cardíacas/etiologia , Cães , Infarto do Miocárdio/complicações , Infarto do Miocárdio/fisiopatologia , Valor Preditivo dos Testes , Projetos de Pesquisa , Fatores de Risco , Fibrilação Ventricular/etiologia
18.
J Am Diet Assoc ; 107(6): 1002-7, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17524721

RESUMO

Twenty-four-hour dietary recalls are used to collect high-quality dietary data. Because they require highly trained interviewers, recalls are expensive and impractical for large-scale nutrition research, leading to the use of food frequency questionnaires. We are developing a computer-based, self-administered 24-hour dietary recall for use by adults. Our goal is an easy-to-use, low-cost, publicly available, Web-enabled instrument that will include elements of the Automated Multiple Pass Method developed by the US Department of Agriculture, which uses five passes to enhance recall. The initial pass is called the "quick list" and allows respondents to report foods consumed the previous day freely, in any order, and without detail. Using a crossover design, we conducted initial formative pilot testing among 18 adults in a self-administered computer environment. We tested two versions of a "quick list" (the first Automated Multiple Pass Method pass) for remembering foods consumed the previous day: "unstructured" and "meal-based." Respondents showed a strong preference for the meal-based version (13 of 18), although positive features of both were identified. Chronological reporting was most common, although many foods were sporadically reported out of order. Versions did not appreciably differ in number of foods reported, moved, or deleted. Usability issues and preferences were also identified. If these developmental efforts prove successful, the use of affordable automated recalls could be valuable in clarifying diet-disease associations in observational epidemiologic studies and measuring dietary compliance in clinical trials. This pilot work illustrates the usefulness of formative cognitive and usability testing for questionnaire and software development.


Assuntos
Inquéritos sobre Dietas , Dieta/estatística & dados numéricos , Rememoração Mental , Avaliação Nutricional , Design de Software , Inquéritos e Questionários/normas , Adolescente , Adulto , Idoso , Automação , Estudos Cross-Over , Feminino , Humanos , Internet , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estados Unidos , United States Department of Agriculture
19.
Popul Health Manag ; 20(S1): S1-S11, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28920768

RESUMO

Sexually Transmitted Infections: Compelling Case for an Improved Screening Strategy Stephen Hull, MHS, Seán Kelley, MD, MSc, and Janice L. Clarke, RN, BBA Editorial: Sexually Transmitted Infections-A Fixable Problem: David B. Nash, MD, MBA S-3 Introduction S-3 Rising Prevalence of Sexually Transmitted Diseases (STIs) S-4 Current Screening Rates for Chlamydia and Gonorrhea S-4 The Human Toll and Economic Burden of STI-Related Illness S-5 Current Screening Guidelines for Chlamydia and Gonorrhea S-5 Factors Contributing to Inadequate Screening, Diagnosis, and Treatment for STIs S-6 Methods Used to Improve Screening Rates S-7 Benefits of Opt-Out Screening Strategies for STIs S-8 Cost-Effectiveness of Screening for STIs S-8 Discussion S-9 Conclusion S-10.


Assuntos
Programas de Rastreamento , Infecções Sexualmente Transmissíveis , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Análise Custo-Benefício , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Programas de Rastreamento/economia , Programas de Rastreamento/métodos , Programas de Rastreamento/estatística & dados numéricos , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/economia , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/prevenção & controle , Adulto Jovem
20.
J Am Diet Assoc ; 106(3): 393-402, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16503230

RESUMO

BACKGROUND: A growing interest exists in using glycemic index and glycemic load as potentially important exposures in investigations of risk for a variety of chronic diseases. OBJECTIVE: We added values for glycemic index and glycemic load to the nutrient database of a commonly used dietary assessment instrument, the Diet History Questionnaire (DHQ). DESIGN: The nutrient database for the DHQ is based on 4,200 individual foods reported by adults in the 1994-1996 US Department of Agriculture Continuing Survey of Food Intakes by Individuals (CSFII). This list was condensed into 225 nutritionally similar groupings of individual foods. Using published glycemic index values we assigned glycemic index values to each of the individual CSFII foods in these food groups. In cases where CSFII foods did not correspond tightly to foods with published glycemic index values, we used decision criteria to assign glycemic index values. We then calculated sex- and serving size-specific glycemic load for each of the 225 food groups using the weighted mean method. Quality assessments were made to help evaluate the success of this method for assigning glycemic load values. RESULTS: Seventy-one percent of the top carbohydrate-contributing food groups had in excess of 90% of the CSFII mentions linked directly to a published glycemic index value (ie, no imputation was required), and 100% of these food groups had at least 50% of total mentions linked directly. CONCLUSIONS: Using this method, it is now possible to use DHQ responses to assess the associations between reported glycemic load and glycemic index and risk of many chronic diseases in epidemiologic studies.


Assuntos
Doença Crônica/epidemiologia , Bases de Dados Factuais , Carboidratos da Dieta/metabolismo , Alimentos/classificação , Índice Glicêmico , Adulto , Glicemia/metabolismo , Peso Corporal/fisiologia , Registros de Dieta , Feminino , Humanos , Masculino , Fatores de Risco , Inquéritos e Questionários , Estados Unidos
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