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1.
Phys Rev Lett ; 130(26): 266701, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37450805

RESUMO

We report resonant elastic x-ray scattering of long-range magnetic order in EuPtSi_{3}, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi_{3} stabilizes type A antiferromagnetism featuring various long-wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fanlike superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized resonant elastic x-ray scattering, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky-Moriya spin-orbit coupling of similar strength.


Assuntos
Temperatura Baixa , Campos Magnéticos , Raios X , Radiografia
2.
Nat Commun ; 14(1): 2246, 2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37076453

RESUMO

Neutron scattering experiments at three-axes spectrometers (TAS) investigate magnetic and lattice excitations by measuring intensity distributions to understand the origins of materials properties. The high demand and limited availability of beam time for TAS experiments however raise the natural question whether we can improve their efficiency and make better use of the experimenter's time. In fact, there are a number of scientific problems that require searching for signals, which may be time consuming and inefficient if done manually due to measurements in uninformative regions. Here, we describe a probabilistic active learning approach that not only runs autonomously, i.e., without human interference, but can also directly provide locations for informative measurements in a mathematically sound and methodologically robust way by exploiting log-Gaussian processes. Ultimately, the resulting benefits can be demonstrated on a real TAS experiment and a benchmark including numerous different excitations.

3.
J Appl Crystallogr ; 55(Pt 6): 1424-1431, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36570654

RESUMO

A modulation of intensity with zero effort (MIEZE) setup is proposed for high-resolution neutron spectroscopy at momentum transfers up to 3 Å-1, energy transfers up to 20 meV and an energy resolution in the microelectronvolt range using both thermal and cold neutrons. MIEZE has two prominent advantages compared with classical neutron spin echo. The first is the possibility to investigate spin-depolarizing samples or samples in strong magnetic fields without loss of signal amplitude and intensity. This allows for the study of spin fluctuations in ferromagnets, and facilitates the study of samples with strong spin-incoherent scattering. The second advantage is that multi-analyzer setups can be implemented with comparatively little effort. The use of thermal neutrons increases the range of validity of the spin-echo approximation towards shorter spin-echo times. In turn, the thermal MIEZE option for greater ranges (TIGER) closes the gap between classical neutron spin-echo spectroscopy and conventional high-resolution neutron spectroscopy techniques such as triple-axis, time-of-flight and back-scattering. To illustrate the feasibility of TIGER, this paper presents the details of its implementation at the RESEDA beamline at FRM II by means of an additional velocity selector, polarizer and analyzer.

4.
BMJ Open ; 12(9): e063365, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36127108

RESUMO

OBJECTIVES: To describe and map scientific literature related to alcohol consumption, its determinants, governance, harm and control policies by publication output, author affiliations, funding, countries of study and research themes. DESIGN: Bibliometric analysis using performance analysis and science mapping techniques. DATA SOURCES: Scientific articles. ELIGIBILITY CRITERIA: Indexed scientific articles published between 1 January 2010 and 31 December 2021 with an English abstract focused on alcohol consumption, its determinants, harms, governance and control policies. DATA EXTRACTION AND SYNTHESIS: Searches were run in Web of Science and PubMed. Performance metrics were analysed using descriptive statistics. Keywords were used for science mapping in a deductive approach to cluster articles by five main research themes. The 'policy response' theme was further analysed by six subthemes. RESULTS: 4553 articles were included in the analysis. Three out of four articles (3479/4553, 76.4%) were authored solely by authors affiliated with HIC institutions. One in five articles (906/4553, 19.9%) had at least one author affiliated to an institution from an upper-middle-income, middle-income or low-income country context. Governments, followed by research institutions, were the predominant funding source. Half (53.1%) studied a single country and, of these, 77.0% were high-income countries (HICs). Australia, USA and UK were the most studied countries, together accounting for 44.9% (975/2172) of country-specific articles. Thematically, 'consumption' was most studied, and 'alcohol determinants', least. 'Policy response' articles were predominately conducted in HIC contexts. CONCLUSIONS: Although the attributable harm of alcohol is known to affect more significantly lower-income and middle-income countries, scientific publications primarily report on HIC contexts by authors from HICs. Research themes reflect known cost-effective policy actions, though skewed towards HICs and a focus on consumption. The implementation of context-specific alcohol control policies requires addressing the determinants of the uneven geographical and thematic distribution of research.


Assuntos
Bibliometria , Publicações , Consumo de Bebidas Alcoólicas , Humanos , Renda , Pobreza
5.
Front Digit Health ; 4: 817810, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35373182

RESUMO

Children and youth merit special attention from digital health policymakers and practitioners because of the great potential for digital transformations to both enhance and undermine their health and wellbeing. However, an analysis of digital health strategies from 10 African countries with young populations suggest that national approaches to digital health are overlooking young people's specific health needs and unique risks in relation to digital technologies and data. To better serve the needs of children and youth in a digital age, future digital health strategies-and the global guidance that many strategies are based upon-should consider the ways in which digital transformations can positively or negatively impact the health and wellbeing of different populations, and the forms of cross-sectoral and multi-stakeholder collaboration required to amplify or mitigate them. Future strategies should be developed through inclusive processes that support young people's right to participate in decision-making that affects their lives.

7.
Acta Odontol Scand ; 79(8): 582-592, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34171197

RESUMO

OBJECTIVE: A new technique of primary tooth autotransplantation has recently been published demonstrating reliable replacement of missing permanent incisors in young children due to trauma or agenesis. This retrospective clinical study reports on the longterm success of this new technique in a larger patient group regarding its potential to support bone and soft tissue growth. STUDY DESIGN: 40 children (age range: 2.7-17.6 years) received 53 primary tooth autotransplants (49 canines and 4 incisors) due to traumatic tooth loss (73%), agenesis (19%) or dysplasia/displacement (8%). Clinical and radiological follow-up examinations were performed to check up on root resorption, bone and soft tissue growth, survival and success. RESULTS: 22 transplants still present in the oral cavity of 18 patients yielded a success rate of 77%. The Kaplan-Meier estimator measured a median survival time of 86 months (7.2 years) for all 53 grafts. In all cases, increasing soft tissue and bone development enabled a successful prosthetic rehabilitation regarding aesthetics and function. CONCLUSIONS: Primary tooth autotransplantation reliably restores edentulous anterior space in children experiencing traumatic tooth loss or agenesis and acts as an immediate therapy before other therapies such as premolar transplantation or orthodontic space closure can be carried out at a later time. It guarantees the co-development of soft tissue and bone in the teenage jaw which is associated with high patient satisfaction and acceptance of this method.


Assuntos
Incisivo , Dente , Adolescente , Criança , Pré-Escolar , Seguimentos , Humanos , Estudos Retrospectivos , Dente/diagnóstico por imagem , Dente Decíduo , Transplante Autólogo , Resultado do Tratamento
8.
J Phys Condens Matter ; 31(38): 385601, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31170703

RESUMO

CeCuAl3 and CeAuAl3, crystallizing in the non-centrosymmetric BaNiSn3 tetragonal structure, are known mainly for their unusual neutron scattering spectra involving additional excitations ascribed to vibron quasi-bound quantum state in CeCuAl3 and anti-crossing of phonon and crystal field excitations in CeAuAl3. In this work, we present results of nuclear magnetic resonance (NMR) experiments on their lanthanum analogues-[Formula: see text] and [Formula: see text]. The character of NMR spectra of [Formula: see text], [Formula: see text], and 65Cu measured in [Formula: see text] and [Formula: see text] is dominated by electric quadrupole interaction. The spectral parameters acquired from experimental data are confronted with values obtained from the electronic structure calculations. The results show remarkable differences for the two compounds. The [Formula: see text] spectrum in [Formula: see text] can be interpreted by a single spectral component corresponding to uniform environment of La atoms in the crystal structure, whereas for [Formula: see text] the spectrum decomposition yields a wide distribution of spectral parameters, which is not possible to explain by a single La environment, and multiple non-equivalent La positions in the crystal structure are required to interpret the spectrum.

9.
Proc Natl Acad Sci U S A ; 116(14): 6695-6700, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30894488

RESUMO

Nearly a century of research has established the Born-Oppenheimer approximation as a cornerstone of condensed-matter systems, stating that the motion of the atomic nuclei and electrons may be treated separately. Interactions beyond the Born-Oppenheimer approximation are at the heart of magneto-elastic functionalities and instabilities. We report comprehensive neutron spectroscopy and ab initio phonon calculations of the coupling between phonons, CEF-split localized 4f electron states, and conduction electrons in the paramagnetic regime of [Formula: see text], an archetypal Kondo lattice compound. We identify two distinct magneto-elastic hybrid excitations that form even though all coupling constants are small. First, we find a CEF-phonon bound state reminiscent of the vibronic bound state (VBS) observed in other materials. However, in contrast to an abundance of optical phonons, so far believed to be essential for a VBS, the VBS in [Formula: see text] arises from a comparatively low density of states of acoustic phonons. Second, we find a pronounced anticrossing of the CEF excitations with acoustic phonons at zero magnetic field not observed before. Remarkably, both magneto-elastic excitations are well developed despite considerable damping of the CEFs that arises dominantly by the conduction electrons. Taking together the weak coupling with the simultaneous existence of a distinct VBS and anticrossing in the same material in the presence of damping suggests strongly that similarly well-developed magneto-elastic hybrid excitations must be abundant in a wide range of materials. In turn, our study of the excitation spectra of [Formula: see text] identifies a tractable point of reference in the search for magneto-elastic functionalities and instabilities.

10.
BMJ Glob Health ; 3(Suppl 1): e000598, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29915672

RESUMO

The annual funding need for global health SDG targets is estimated by WHO at US$134 billion per year, rising to US$274-$371bn by 2030. This paper examines the challenge of making sustainable investment structures in global health more attractive for mainstream financial markets. The objective is a framework for targeted future debate with financial sector actors. Four case studies of innovative sustainable investment mechanisms are analysed, elaborating potential transfer of green and impact investment models in order to channel additional private sector funds to health. To increase private sector involvement, profit must accrue to providers of finance. The paper shows how health criteria can be incorporated into structures, which create triple bottom line return opportunities. Health infrastructure projects based on risk sharing models with governments or multilateral agencies could use long-term funding, with better credit ratings and lower cost of capital. Outcomes based investment, similar to green or social impact bonds, with third-party certification of measurable health impact, satisfy the private sector need for return with social interest objectives. Responsible investment could expand by adding a 'health' (H) criterion to the Environmental, Social and Governance (ESG) framework, implementing ESG+H for mainstream investment screening. These models are scalable, satisfy the need to dedicate funds to health and incorporate consistent critical success metrics. The conclusion finds that strong legal frameworks and exploration of fiscal incentives will be critical next steps to facilitate scaling up and broadening of interest from private sector financial actors. The impact these investments have on overall population health is a positive externality of sustainable global health investment.

11.
BMJ Glob Health ; 3(Suppl 1): e000597, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29736278

RESUMO

The world faces multiple health financing challenges as the global health burden evolves. Countries have set an ambitious health policy agenda for the next 15 years with prioritisation of universal health coverage under the Sustainable Development Goals. The scale of investment needed for equitable access to health services means global health is one of the key economic opportunities for decades to come. New financing partnerships with the private sector are vital. The aim of this study is to unlock additional financing sources, acknowledging the imperative to link financial returns to the providers of capital, and create profitable, sustainable financing structures. This paper outlines the global health investment opportunity exploring intersections of financial and health sector interests, and the role investment in health can play in economic development. Considering increasing demand for impact investments, the paper explores responsible financing initiatives and expansion of the global movement for sustainable capital markets. Adding an explicit health component (H) to the Environmental, Social and Governance (ESG) investment criteria, creating the ESG+H initiative, could serve as catalyst for the inclusion of health criteria into mainstream financial actors' business practices and investment objectives. The conclusion finds that health considerations directly impact profitability of the firm and therefore should be incorporated into financial analysis. Positive assessment of health impact, at a broad societal or environmental level, as well as for a firm's employees can become a value enhancing competitive advantage. An ESG+H framework could incorporate this into mainstream financial decision-making and into scalable investment products.

15.
Lancet ; 390(10097): 898-912, 2017 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-28684024

RESUMO

Germany has become a visible actor in global health in the past 10 years. In this Series paper, we describe how this development complements a broad change in perspective in German foreign policy. Catalysts for this shift have been strong governmental leadership, opportunities through G7 and G20 presidencies, and Germany's involvement in managing the Ebola virus disease outbreak. German global health engagement has four main characteristics that are congruent with the health agenda of the Sustainable Development Goals; it is rooted in human rights, multilateralism, the Bismarck model of social protection, and a link between development and investment on the basis of its own development trajectory after World War 2. The combination of momentum and specific characteristics makes Germany well equipped to become a leader in global health, yet the country needs to accept additional financial responsibility for global health, expand its domestic global health competencies, reduce fragmentation of global health policy making, and solve major incoherencies in its policies both nationally and internationally.


Assuntos
Saúde Global/tendências , Política de Saúde , Liderança , Política , Política Pública/tendências , Alemanha , Governo , Humanos , Cooperação Internacional
16.
Eur J Pharm Biopharm ; 115: 84-93, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28232106

RESUMO

The 3D printing technique of fused deposition modeling® (FDM) has lately come into focus as a potential fabrication technique for pharmaceutical dosage forms and medical devices that allows the preparation of delivery systems with nearly any shape. This is particular promising for implants administered at application sites with a high anatomical variability where an individual shape adaption appears reasonable. In this work different polymers (Eudragit®RS, polycaprolactone (PCL), poly(l-lactide) (PLLA) and ethyl cellulose (EC)) were evaluated with respect to their suitability for FDM of drug loaded implants and their drug release behaviour was evaluated. The fluorescent dye quinine was used as a model drug to visualize drug distribution in filaments and implants. Quinine loaded filaments were produced by solvent casting and subsequent hot melt extrusion (HME) and model implants were printed as hollow cylinders using a standard FDM printer. Parameters were found at which model implants (hollow cylinders, outer diameter 4-5mm, height 3mm) could be produced from all tested polymers. The drug release which was examined by incubation of the printed implants in phosphate buffered saline solution (PBS) pH 7.4 was highly dependent on the used polymer. The fastest relative drug release of approximately 76% in 51days was observed for PCL and the lowest for Eudragit®RS and EC with less than 5% of quinine release in 78 and 100days, respectively. For PCL further filaments were prepared with different quinine loads ranging from 2.5% to 25% and thermal analysis proved the presence of a solid dispersion of quinine in the polymer for all tested concentrations. Increasing the drug load also increased the overall percentage of drug released to the medium since nearly the same absolute amount of quinine remained trapped in PCL at the end of drug release studies. This knowledge is valuable for future developments of printed implants with a desired drug release profile that might be controlled by the choice of the polymer and the drug load.


Assuntos
Implantes de Medicamento/química , Preparações Farmacêuticas/química , Polímeros/química , Resinas Acrílicas/química , Celulose/análogos & derivados , Celulose/química , Liberação Controlada de Fármacos/efeitos dos fármacos , Poliésteres/química , Impressão Tridimensional , Quinina/química , Tecnologia Farmacêutica/métodos
18.
Biomed Tech (Berl) ; 61(s1): 125-132, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27682693
19.
Sci Rep ; 5: 8945, 2015 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-25755010

RESUMO

Thermoelectric effects in magnetic tunnel junctions are promising to serve as the basis for logic devices or memories in a "green" information technology. However, up to now the readout contrast achieved with Seebeck effects was magnitudes smaller compared to the well-established tunnel magnetoresistance effect. Here, we resolve this problem by demonstrating that the tunnel magneto-Seebeck effect (TMS) in CoFeB/MgO/CoFeB tunnel junctions can be switched on to a logic "1" state and off to "0" by simply changing the magnetic state of the CoFeB electrodes. This new functionality is achieved by combining a thermal gradient and an electric field. Our results show that the signal crosses zero and can be adjusted by tuning a bias voltage that is applied between the electrodes of the junction; hence, the name of the effect is bias-enhanced tunnel magneto-Seebeck effect (bTMS). Via the spin- and energy-dependent transmission of electrons in the junction, the bTMS effect can be configured using the bias voltage with much higher control than the tunnel magnetoresistance and even completely suppressed for only one magnetic configuration. Moreover, our measurements are a step towards the experimental realization of high TMS ratios without additional bias voltage, which are predicted for specific Co-Fe compositions.

20.
J Phys Condens Matter ; 25(42): 425301, 2013 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-24077299

RESUMO

The theoretical description of modern nanoelectronic devices requires a quantum mechanical treatment and often involves disorder, e.g. from alloys. Therefore, the ab initio theory of transport using non-equilibrium Green's functions is extended to the case of disorder described by the coherent potential approximation. This requires the calculation of non-equilibrium vertex corrections. We implement the vertex corrections in a Korringa-Kohn-Rostoker multiple scattering scheme. In order to verify our implementation and to demonstrate the accuracy and applicability we investigate a system of an iron-cobalt alloy layer embedded in copper. The results obtained with the coherent potential approximation are compared to supercell calculations. It turns out that vertex corrections play an important role for this system.

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