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1.
Molecules ; 28(2)2023 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-36677823

RESUMO

Coatings of metal specimens are known to have an impact on hydrogen gettering (hydrogen absorption). The coating can have one or more functions, such as enhancing gettering, preventing gettering and/or preventing oxidation of the metal substrate. It is known that contaminants and surface texture can impact hydrogen gettering/absorption performance, but has not previously been thoroughly explored. This study evaluated the role of different post-plating heat treatments of nickel-plated zircaloy-4 getters (NPGs) and the role of the heat treatments on gettering rates, surface composition and texture. Nickel plating is applied to prevent oxidation of the Zircaloy-4 surface and also enhances gettering. The nickel plating must be heat treated before desirable gettering can occur. Our NPG getters with historically known satisfying performance were pre-heat treated in air followed by activation heat treatment in a vacuum at a higher temperature. In this study, we were interested in finding out if both heat treatment steps were necessary to obtain a desirable gettering performance, or if one step could be omitted. XPS analysis showed that if the nickel surface is not heat treated before bonding the nickel to the zirconium in the activation step, there will be carbon contaminants on the surface, which significantly reduces gettering. We studied the texture of Zircaloy-4 using SEM/EBSD to compare NPGs with both heat treatment steps with NPGs that had no post-plating heat treatment to learn if the degree of cold work could be impacted by the heat treatment steps. We did not observe any differences in texture between them. We measured gettering rates of both pretreated and activated NPGs and NPGs that had been activated without first being pre-heat treated. We found that the NPGs without the first post-plating heating step had up to a seven times slower gettering rate and obtained higher plateau pressures due to the contaminated surface. Thus, the pre-heat treatment in air before activation is necessary to avoid slower gettering rates and higher plateau pressures.


Assuntos
Galactosilceramidas , Níquel , Níquel/química , Temperatura Alta , Temperatura Baixa
2.
Health Res Policy Syst ; 16(1): 73, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-30071858

RESUMO

Major pharmaceutical companies contribute important expertise to health research and development (R&D), particularly in their ability to develop and bring pharmaceuticals to market. The Access to Medicine Index evaluates how 20 of the world's largest pharmaceutical companies are directing R&D efforts towards the needs of people living in low- and middle-income countries. In dissemination of its findings, the Index stimulates pharmaceutical companies to expand R&D activities in this direction. The Index methodology is reviewed every 2 years, most recently for the 2018 Index, to ensure their R&D activity is benchmarked against current health R&D priorities as defined by the global health community. The review is based on consensus-building processes involving global health stakeholders. In the latest review, two main changes to the methodology were made that will further deepen the Index's analysis of (1) how far companies' R&D activity aligns with global health priorities; and (2) whether companies make plans to ensure resulting innovations reach populations in need globally. These changes will be applied in the 2018 Access to Medicine Index. Importantly, the methodology review process highlighted the need for further prioritisation from the global health community, in particular to emphasise to innovators which product innovations are needed most critically to address the burden of non-communicable diseases in low- and middle-income countries. Should such prioritisations be developed, the Index can play an important role in tracking and stimulating company contributions towards them.


Assuntos
Pesquisa Biomédica , Países em Desenvolvimento , Difusão de Inovações , Indústria Farmacêutica , Estudos de Avaliação como Assunto , Prioridades em Saúde , Acessibilidade aos Serviços de Saúde , Saúde Global , Necessidades e Demandas de Serviços de Saúde , Humanos , Disseminação de Informação , Motivação , Doenças não Transmissíveis , Pesquisa
5.
Bull World Health Organ ; 93(11): 799-805, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26549908

RESUMO

Hepatitis C is a global epidemic. Worldwide, 185 million people are estimated to be infected, most of whom live in low- and middle-income countries. Recent advances in the development of antiviral drugs have produced therapies that are more effective, safer and better tolerated than existing treatments for the disease. These therapies present an opportunity to curb the epidemic, provided that they are affordable, that generic production of these medicines is scaled up and that awareness and screening programmes are strengthened. Pharmaceutical companies have a central role to play. We examined the marketed products, pipelines and access to medicine strategies of 20 of the world's largest pharmaceutical companies. Six of these companies are developing medicines for hepatitis C: AbbVie, Bristol-Myers Squibb, Gilead, Johnson & Johnson, Merck & Co. and Roche. These companies employ a range of approaches to supporting hepatitis C treatment, including pricing strategies, voluntary licensing, capacity building and drug donations. We give an overview of the engagement of these companies in addressing access to hepatitis C products. We suggest actions companies can take to play a greater role in curbing this epidemic: (i) prioritizing affordability assessments; (ii) developing access strategies early in the product lifecycle; and (iii) licensing to manufacturers of generic medicines.


L'hépatite C est une épidémie mondiale. On estime à 185 millions le nombre d'individus infectés par ce virus dans le monde, la plupart vivant dans des pays à revenu faible ou intermédiaire. Les récents progrès dans la mise au point de médicaments antiviraux ont conduit à des traitements plus efficaces, plus surs et mieux tolérés que les traitements existants pour soigner cette maladie. Ces traitements permettraient de freiner l'épidémie, à condition que leur coût soit abordable, que la production de médicaments génériques soit intensifiée et que les programmes de sensibilisation et de dépistage soient renforcés. Les sociétés pharmaceutiques ont, à cet égard, un rôle central à jouer. Nous avons examiné les produits commercialisés, les produits à l'étude et les stratégies d'accès aux médicaments de 20 des plus importantes sociétés pharmaceutiques mondiales. Six de ces sociétés développent des médicaments pour soigner l'hépatite C: AbbVie, Bristol-Myers Squibb, Gilead, Johnson & Johnson, Merck & Co. et Roche. Ces sociétés adoptent diverses approches pour faciliter le traitement de l'hépatite C, qui reposent notamment sur des stratégies de fixation des prix, l'octroi volontaire de licences, un renforcement des capacités et des dons de médicaments. Nous donnons un aperçu des efforts déployés par ces sociétés pour faciliter l'accès aux médicaments permettant de soigner l'hépatite C, et proposons des actions que peuvent mener ces sociétés afin de jouer un plus grand rôle dans l'enraiement de cette épidémie: (i) donner un degré de priorité élevé aux évaluations de l'accessibilité économique; (ii) développer des stratégies d'accès au début du cycle de vie du produit; et (iii) octroyer des licences aux fabricants de médicaments génériques.


La hepatitis C es una epidemia global. Se estima que, en todo el mundo, hay 185 millones de personas infectadas, la mayoría de las cuales viven en países de ingresos bajos y medios. Los recientes avances en el desarrollo de antivirales han producido terapias más efectivas, seguras y de mejor tolerancia que los tratamientos para la enfermedad existentes. Estas terapias presentan una oportunidad para poner freno a la epidemia, siempre y cuando sean asequibles, aumentar la producción genérica de dichos medicamentos y reforzar los programas de sensibilización y detección. Las empresas farmacéuticas juegan un papel central. Se examinaron los productos comercializados, tuberías y estrategias de acceso a los medicamentos de veinte de las mayores empresas farmacéuticas del mundo. Seis de estas empresas están desarrollando medicamentos para tratar la hepatitis C: AbbVie, Bristol-Myers Squibb, Gilead, Johnson & Johnson, Merck & Co. y Roche. Estas empresas emplean una gama de enfoques para apoyar el tratamiento para la hepatitis C, incluyendo las estrategias de fijación de precios, la concesión voluntaria de licencias, la creación de capacidad y las donaciones de medicamentos. Ofrecemos una visión general del compromiso de estas empresas a la hora de ofrecer acceso a los productos para tratar la hepatitis C. Sugerimos acciones que las empresas pueden llevar a cabo para tener un papel más importante a la hora de frenar esta epidemia: (i) dar prioridad a los criterios de asequibilidad; (ii) desarrollar estrategias de acceso al principio del ciclo de vida del producto; y (iii) ofrecer licencias a los fabricantes de medicamentos genéricos.


Assuntos
Antivirais/provisão & distribuição , Antivirais/uso terapêutico , Acessibilidade aos Serviços de Saúde , Hepatite C/tratamento farmacológico , Antivirais/economia , Países em Desenvolvimento , Custos de Medicamentos , Indústria Farmacêutica/economia , Humanos , Internacionalidade , Relações Interprofissionais
6.
Lancet ; 382(9900): 1286-307, 2013 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-23697824

RESUMO

The need to align investments in health research and development (R&D) with public health demands is one of the most pressing global public health challenges. We aim to provide a comprehensive description of available data sources, propose a set of indicators for monitoring the global landscape of health R&D, and present a sample of country indicators on research inputs (investments), processes (clinical trials), and outputs (publications), based on data from international databases. Total global investments in health R&D (both public and private sector) in 2009 reached US$240 billion. Of the US$214 billion invested in high-income countries, 60% of health R&D investments came from the business sector, 30% from the public sector, and about 10% from other sources (including private non-profit organisations). Only about 1% of all health R&D investments were allocated to neglected diseases in 2010. Diseases of relevance to high-income countries were investigated in clinical trials seven-to-eight-times more often than were diseases whose burden lies mainly in low-income and middle-income countries. This report confirms that substantial gaps in the global landscape of health R&D remain, especially for and in low-income and middle-income countries. Too few investments are targeted towards the health needs of these countries. Better data are needed to improve priority setting and coordination for health R&D, ultimately to ensure that resources are allocated to diseases and regions where they are needed the most. The establishment of a global observatory on health R&D, which is being discussed at WHO, could address the absence of a comprehensive and sustainable mechanism for regular global monitoring of health R&D.


Assuntos
Pesquisa Biomédica/estatística & dados numéricos , Bases de Dados como Assunto/estatística & dados numéricos , Saúde Pública/estatística & dados numéricos , Pesquisa Biomédica/economia , Ensaios Clínicos como Assunto/estatística & dados numéricos , Coleta de Dados , Países Desenvolvidos/economia , Países Desenvolvidos/estatística & dados numéricos , Países em Desenvolvimento/economia , Países em Desenvolvimento/estatística & dados numéricos , Saúde Global/economia , Saúde Global/estatística & dados numéricos , Humanos , Disseminação de Informação , Avaliação das Necessidades/estatística & dados numéricos , Editoração/estatística & dados numéricos , Apoio à Pesquisa como Assunto/economia , Apoio à Pesquisa como Assunto/estatística & dados numéricos
7.
Front Reprod Health ; 5: 1144217, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37266447

RESUMO

Introduction: Women in sub-Saharan Africa (SSA) experience the world's highest rates of both HIV infection and unintended pregnancy. The Dual Prevention Pill (DPP) is a novel multipurpose prevention technology (MPT) that co-formulates HIV pre-exposure prophylaxis (PrEP) and combined hormonal oral contraception into a single daily pill. As a dual indication product, the DPP may be preferred by women facing these overlapping health risks. However, most SSA countries face severe healthcare resource constraints. Research is needed to assess whether, in what populations, and in what use cases the DPP would be cost-effective. Methods: We augmented an agent-based SSA HIV model with maternal health parameters including unintended pregnancy, abortion, and maternal mortality. Based on a previous market analysis, we assumed a primary DPP user population of current oral contraceptive users ages 25-49, and alternative user populations in different risk groups (age 15-24, sex workers, HIV-serodiscordant couples) and baseline product use profiles (unmet need for contraception, oral PrEP use, condom use). In three geographies (western Kenya, Zimbabwe, South Africa), we estimated HIV infections averted, pregnancies averted, disability-adjusted life-years (DALYs) averted, and the incremental cost-effectiveness ratio (ICER) over a 30-year time horizon, assuming equivalent adherence to the DPP as to oral contraceptives, higher adherence, or lower adherence. Results: The DPP is likely to be a cost-effective alternative to oral PrEP among users in need of contraception. Among women not already using PrEP, the DPP is likely to be cost-saving in sex workers and serodiscordant couples. The DPP is unlikely to be cost-effective in oral contraceptive users in the general population. Switching from oral contraception to the DPP could be net harmful in some settings and populations if it were to substantially reduces adherence to oral contraception. Results were robust to a range of time horizons or discount rates. Conclusion: The DPP has the potential to be cost-effective and cost-saving in populations at substantial HIV risk. Outcomes are sensitive to adherence, implying that effective counseling and decision-making tools for users considering the DPP will be essential. More research is needed to understand real-life adherence patterns and ensure health benefits achieved from contraception alone are not lost.

8.
J Electron Microsc (Tokyo) ; 61(6): 393-400, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23042825

RESUMO

Formation of nanoscale helium (He) bubbles in reduced activation ferritic/martensitic steels may lead to degradation of mechanical properties of materials. Transmission electron microscopy (TEM) has commonly been used to image the Fresnel contrast of He bubbles, using an underfocus of 0.5-1 µm. This paper presents our study of multislice simulation of the size correlation between imaged Fresnel rings and the actual He bubbles. It was found that for bubbles equal to or >3 nm in diameter, the imaged bubble size, represented by its inner diameter of the first dark Fresnel ring (D(in)) in underfocused imaging conditions, increases with increasing electron-beam incoherency, but decreases with increasing underfocus. The electron-beam accelerating voltage, bubble size, bubble position and TEM sample thickness were found to have no significant influence on the deviation of D(in) from the actual bubble size (D(0)). However, for bubbles equal to or <2 nm, D(in)/D(0) increases dramatically with increasing underfocus when it is above a threshold limit (e.g. Δf = -1 µm for a 2-nm bubble). The results of this study also suggested that He bubbles can be differentiated from argon (Ar) bubbles by contrast differences.

9.
J Pharm Policy Pract ; 12: 26, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31508235

RESUMO

BACKGROUND: Two billion people worldwide, predominantly in low- and middle-income countries, cannot consistently access required essential medications, thus affecting their ability to attain optimal health outcomes. Access to appropriate medicines may be compromised due to issues involving cost, availability, quality, and prescribing practices, and system-wide factors such as a lack of transparency and accountability. Pharmaceutical promotional practices impact many of these issues, thus influencing the use of appropriate medicines,. Good governance is ultimately the responsibility of national governments through strong health systems with transparent and accountable practices that facilitate appropriate medicine use. We designed a structured set of indicators, based on existing tools, to assess the strength of the national governance of pharmaceutical promotion. In this exploratory study, we trialed the indicators in Ghana. METHODS: Two existing tools, one developed by the World Health Organization and the other by Health Action International with the Medicines Transparency Alliance, were adapted to examine the governance of pharmaceutical promotion, resulting in a hybrid framework of 45 indicators of system strength, grouped into four categories: a) Governance of prescription medicines, b) Health care professional codes and regulations, c) Anti-corruption governance, and d) Indexes. Evidence was gathered via desk-based research to establish whether indicator requirements were met. RESULTS: Our desk-based research discovered the following: a) 21 of 45 indicators for the governance of prescription medicines were met in Ghana, including the existence of a national medicines policy, national medicines list, medicines regulatory authority and a national guide for the promotion of prescription pharmaceuticals; b) pharmacists have a code of conduct specific to ethical promotion though co-development with the pharmaceutical industry should be further examined; and c) anti-corruption indicators were met for 10 of 12 criteria; and d) two indexes were available that were relevant to Ghana. CONCLUSION: Our set of indicators identified gaps and opportunities for the governance of medicines promotion in Ghana. These indicators have the potential to highlight areas requiring improved governance and could therefore form a useful diagnostic tool for identifying key discussion points for policy strengthening within low- and middle-income countries.

10.
Sci Rep ; 9(1): 12744, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484940

RESUMO

Crystalline materials exhibit long-range ordered lattice unit, within which resides nonperiodic structural features called defects. These crystallographic defects play a vital role in determining the physical and mechanical properties of a wide range of material systems. While computer vision has demonstrated success in recognizing feature patterns in images with well-defined contrast, automated identification of nanometer scale crystallographic defects in electron micrographs governed by complex contrast mechanisms is still a challenging task. Here, building upon an advanced defect imaging mode that offers high feature clarity, we introduce DefectSegNet - a new convolutional neural network (CNN) architecture that performs semantic segmentation of three common crystallographic defects in structural alloys: dislocation lines, precipitates and voids. Results from supervised training on a small set of high-quality defect images of steels show high pixel-wise accuracy across all three types of defects: 91.60 ± 1.77% on dislocations, 93.39 ± 1.00% on precipitates, and 98.85 ± 0.56% on voids. We discuss the sources of uncertainties in CNN prediction and the training data in terms of feature density, representation and homogeneity and their effects on deep learning performance. Further defect quantification using DefectSegNet prediction outperforms human expert average, presenting a promising new workflow for fast and statistically meaningful quantification of materials defects.

11.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 9): 1291-1296, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31523452

RESUMO

A cadmium germanium arsenide compound, Cd3Ge2As4, was synthesized using a double-containment fused quartz ampoule method within a rocking furnace and a melt-quench technique. The crystal structure was determined from single-crystal X-ray diffraction (SC-XRD), scanning and transmission electron microscopies (i.e. SEM, STEM, and TEM), and selected area diffraction (SAD) and confirmed with electron backscatter diffraction (EBSD). The chemistry was verified with electron energy loss spectroscopy (EELS).

12.
Ultramicroscopy ; 193: 12-23, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29906519

RESUMO

Dislocation imaging using transmission electron microscopy (TEM) has been an invaluable tool for characterizing crystallographic defects in metals. Compared to conventional TEM imaging, diffraction contrast imaging scanning transmission electron microscopy (DCI STEM) with appropriate setting can provide better defect contrast with almost negligible bend contour artifacts, enabling more effective analysis of dislocation structures. Here, we investigated why STEM can suppresses bend contour, and how dislocation contrast behaves along with different STEM imaging parameters. Using a body-centered cubic HT-9 ferritic/martensitic alloy as an example, a simple procedure and operational theory are described at the beginning to help set up DCI STEM experiments. Comparing with conventional TEM and the STEM strictly complying with the principle of reciprocity, we found that a pair of STEM convergence and collection semi-angles, αS and ßS, a few milliradians in size is essential for bend-contour-free defect imaging. It works in concert such that the convergence STEM probe opens up the reciprocal space, and then a comparable collection region evens out the rocking-curve oscillation and alleviates bend contours from the reciprocal space. This fundamental advantage is unique in DCI STEM. Practical guidelines regarding STEM parameters and specimen orientation and thickness are then provided for DCI STEM dislocation imaging. Lastly, we show that coupling DCI STEM with spectrum images of electron energy loss spectroscopy and of energy-dispersive X-ray Spectroscopy offers a comprehensive characterization of crystallographic defects and chemical information of complex microstructures.

13.
Sci Rep ; 7(1): 15813, 2017 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-29150617

RESUMO

Accelerator-based ion beam irradiation techniques have been used to study radiation effects in materials for decades. Although carbon contamination induced by ion beams in target materials is a well-known issue in some material systems, it has not been fully characterized nor quantified for studies in ferritic/martensitic (F/M) steels that are candidate materials for applications such as core structural components in advanced nuclear reactors. It is an especially important issue for this class of material because of the strong effect of carbon level on precipitate formation. In this paper, the ability to quantify carbon contamination using three common techniques, namely time-of-flight secondary ion mass spectroscopy (ToF-SIMS), atom probe tomography (APT), and transmission electron microscopy (TEM) is compared. Their effectiveness and shortcomings in determining carbon contamination are presented and discussed. The corresponding microstructural changes related to carbon contamination in ion irradiated F/M steels are also presented and briefly discussed.

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