This paper is one of a series exploring the implications of complexity for systematic reviews and guideline development, commissioned by the WHO. The paper specifically explores the role of qualitative evidence synthesis. Qualitative evidence synthesis is the broad term for the group of methods used to undertake systematic reviews of qualitative research evidence. As an approach, qualitative evidence synthesis is increasingly recognised as having a key role to play in addressing questions relating to intervention or system complexity, and guideline development processes. This is due to the unique role qualitative research can play in establishing the relative importance of outcomes, the acceptability, fidelity and reach of interventions, their feasibility in different settings and potential consequences on equity across populations. This paper outlines the purpose of qualitative evidence synthesis, provides detail of how qualitative evidence syntheses can help establish understanding and explanation of the complexity that can occur in relation to both interventions and systems, and how qualitative evidence syntheses can contribute to evidence to decision frameworks. It provides guidance for the choice of qualitative evidence synthesis methods in the context of guideline development for complex interventions, giving ‘real life’ examples of where this has occurred. Information to support decision-making around choice qualitative evidence synthesis methods in the context of guideline development is provided. Approaches for reporting qualitative evidence syntheses are discussed alongside mechanisms for assessing confidence in the findings of a review. Qualitative evidence syntheses (QES) enable researchers to gain a greater understanding of individual’s experiences, views, beliefs and priorities for healthcare.QES are beginning to be incorporated in the development of guidelines for complex interventions.Detail is provided on how QES can help explain the complexity that can occur in relation to both interventions and systems.Guidance is given for the choice of QES methodology in the context of guideline development for complex interventions.Guideline producers are encouraged to consider the role of QES for reviews and guidelines on complex interventions implemented in complex systems.This paper is one of a series exploring the implications of complexity for systematic reviews and guideline development, commissioned by the WHO. The paper specifically explores the role of qualitative evidence synthesis (QES), the types of questions likely to be addressed and the methods available in the context of guideline development for complex interventions and systems. It offers options for guideline developers to assist in making informed decisions about which QES methods to adopt.Qualitative evidence synthesis (QES) is an umbrella term for the methodologies associated with the systematic review of qualitative research evidence, conducted either as a stand-alone review or as a part of a review of complex interventions, systems or of guideline development.Methods for conducting QES have developed against a backdrop of increasing demand from decision makers for evidence that goes beyond ‘what works’; a form of evidence traditionally established through systematic reviews of quantitative evidence, particularly reviews of randomised controlled trials (RCT). It is increasingly recognised that healthcare provision involves complex, multifactorial decisions which may require more than this original ‘rationalist’ model of synthesis can provide.2In understanding why a QES can have a central role within guideline development for complex interventions or systems, it is important to appreciate the purpose of qualitative research, on which a QES is reliant. Qualitative research is generally interpretative in nature and through this seeks to develop understanding of and explanation for the behaviours, experiences and interactions of individuals and the social contexts in which these occur. Within the broad context of health, qualitative approaches can help determine the attitudes, beliefs and perspectives of patients, carers and clinicians to a condition, intervention, policy, context and structure of healthcare; can help understanding of the interpersonal nature of caregiver and patient relationships and behaviours; or enable insight into an illness experience.Health-related behaviours or experiences of illness.Why and how a policy or intervention works.Appropriateness or acceptability of interventions.Barriers and facilitators to implementation of interventions.Gaps in primary qualitative research evidence, for example, gaps about knowledge of the acceptability of intervention.A QES, when used within clinical, public health, policy and health systems, can explore:One of the strengths of QES is the ability to bring together multiple perspectives, including contradictory viewpoints, which may not be represented within a single study alone.1Exploring intervention complexity.Examining the context and success or failure of implementation.Determining the impact of wider health system issues.Exploring issues with fidelity, dose, reach, equity, process and outcomes.In addition QES can, in relation to the specific focus to this paper, help inform the evaluation and implementation of complex interventions by:Therefore, QES can be useful within a guideline development process by helping to explain the complexity that can occur in relation to interventions; whether this complexity exists within the intervention itself , or within the system in which the intervention is to be implemented (understanding the dynamic properties of the context into which the intervention is to be introduced).Box 1Develop a theory of why and how an intervention (complex or simple) works.Explore the experiences of recipients or providers of healthcare.Explore the experiences of living with a condition, which can impact on the feasibility and acceptability of an intervention.Examine the factors affecting implementation, including context.Determine how components of complex interventions work to produce effects.Establish how and why the implementation of interventions varies across contexts.Examine how a system changes when a complex intervention is introduced.What explains changes in the system over time.Depending on the purpose of the review, and drawing on the first paper in the series,An example of the way in which recipient experiences of a service can be integrated into the development of a guideline is demonstrated through the recent WHO recommendations on antenatal care for a positive pregnancy experience.5Box 2Balance of health benefits and harms.Human rights and sociocultural acceptability.Health equity, equality and non-discrimination.Societal implications.Financial and economic considerations.Feasibility and health system considerations.A QES can be conducted separately or can be integrated with some form of quantitative synthesis. Within a guideline development process, findings from a QES will often be integrated with evidence of effectiveness in an evidence to decision (EtD) framework, used to formulate recommendations.8Guidelines may be developed for many different purposes, including to inform clinical, public health and health system programmes and policies. Within the guideline process the research question underpins the purpose and, ultimately, the methods of a review. Unlike the typically fixed Population-Intervention-Comparison-Outcome question of quantitative synthesis, a QES question may be used as either the ‘compass’ or the ‘anchor’ for the review.11–13Problem framing: Identifying the issues that need addressing.QES is used in reviews of complex interventions and guideline development to increase understanding of aspects such as context, implementation and views of a complex intervention. As a result, the issues that need addressing are directly linked to the need for evidence that describes or explains the phenomenon. There are multiple ways to frame a problem which subsequently inform the direction a review may take. A transparent process is recommended, as the review question may be revised on the basis of preliminary findings from the problem framing.14Involving stakeholders in problem framing is key, in order to explore ‘What’, ‘For whom’ and ‘Why’ and in ‘What context’ the problem exists. Through consultation with stakeholders, issues such as acceptability and implementation challenges will become apparent.Constructing a preliminary framework or logic model to illustrate relationships.The use of theoretical frameworks or logic models in reviews of complex interventions/systems is becoming increasingly common across all types of QES. Such frameworks or models seek to present relationships between the problem, its explanatory evidence, how it may be implemented and its outcomes which, in turn, inform the focus and direction of the review.14Developing an understanding of context: Selecting a contextual frame that is appropriate to the complexity of the review question.et al in this series.19One of the fundamental purposes of a QES conducted with a complexity perspective is to develop an understanding of relevant contextual factors. Knowledge of such factors will inform decisions on the ultimate scope of the search, inclusion and exclusion criteria and later considerations of transferability. How context may be addressed in relation to question formulation is explained in more detail in the paper by Booth Identifying potential lines of inquiry: Considering which questions relate to effectiveness, implementation, feasibility, appropriateness of the intervention or strategy for implementation.The qualitative component of a review of complex interventions/systems may select one or more lines of inquiry in order to fully interrogate the question. Lines of inquiry addressed by the qualitative component can include questions about meaningfulness, appropriateness, feasibility, equity, affordability and implementation.Searching to explore the knowledge base: Scoping the amount and type of knowledge and evidence currently available.Scoping the literature is vital to allow for the emergence of clear research questions to guide the reviewers.14Formulating, focusing and refining questions: In relation to what is already known.Following scoping, the review question can be revisited or refocused where required prior to the main review searches being undertaken. Frameworks for structuring the question are well established,Developing the protocol: Using the preliminary questions and searching to understand how and why an intervention might work, taking into account the interactions between individuals and surrounding context.A protocol should be developed that presents an argument for the importance of the review, its relevance to the problems described and its potential utility to policymakers. The review question(s) should emerge naturally from the preliminary work and should include an approach to both the selection and appraisal of studies and synthesis that potentially enables reviewers to answer the questions.Further guidance on determining the focus of a QES to inform or explain effectiveness and complexity is provided elsewhere.The choice of method for a QES depends on the nature of the problem or research question being framed, the relationships determined within the framework, context and potential lines of enquiry and the literature available. Established and evolving methods for QES sit on a continuum between interpretative and integrative positions, the choice of which is determined by the focus of the review and the need to understand complexity within it.22When considering the use of the methods for a QES it is helpful to recognise the ongoing variation in the use of terminology associated with QES; a number of terms have evolved as the approaches to QES have developed. QES is used as the overall term to refer to all methods that involve bringing together diverse types of qualitative evidence and is the term favoured by international groups such as the Cochrane Qualitative and Implementation Methods Group (CQIMG). This is due to its flexibility to incorporate broad types of qualitative evidence , and also its acknowledgement that a separate set of methods, sensitive to the qualitative paradigm of research, is required.There is currently a range of methods available for QES, at varying levels of development and sophistication. Many draw on the principles of primary qualitative research and extend these to the level of synthesis. There are broad categories of QES on a continuum between integrative and interpretive approaches. Integrative synthesis focuses on summarising or aggregating data or themes, is a more deductive approach and often used when concepts or themes are clearly defined in primary research. Examples of such methods are thematic synthesis and framework synthesis. Interpretive synthesis allows for the development of concepts and theories grounded in the data contained in the primary studies; themes are developed inductively and the aim is to generate concepts and further develop theory, for example, using meta-ethnography. The approach to QES taken is dependent on the question and scope of the review.There are specific considerations when choosing a QES methodology within the context of reviews of complex interventions and guideline development. Another paper in this series outlines the philosophical approaches and methods for integration.et al.21With these caveats in mind, aspects to consider when choosing a QES methodology are presented below . These aExamples of how the methods have been used in the context of guideline development follow.When a guideline tackles a question relating to sociocultural acceptability of a complex intervention, a QES using thematic synthesis may work well due to its ability to develop either descriptive or analytic themes to inform the guideline. Although ‘thematic synthesis’ is an umbrella term covering several different ways of synthesising qualitative evidence to develop themes, the various approaches follow similar methods and synthesis processes. Thomas and Harden’s version of thematic synthesis8The National Institute for Health and Care Excellence (NICE) commissioned a guideline on long-term rehabilitation after stroke.The findings from the seven included quantitative studies highlighted that the standard approaches to goal setting for patients used by health professionals did not incorporate a patient-centred approach. The findings of the thematic synthesis identified that patients considered active participation in goal setting as vital to their rehabilitation.When a question in a guideline relates to feasibility or health system considerations, framework synthesis is a good choice of QES method due to the extent of the complexity the method can accommodate. As with thematic synthesis, the origins of framework synthesis can be traced to a corresponding method from primary research; in this case framework analysis. Framework analysis was developed by qualitative researchers in 1994 and is particularly suited for policy analysis.Framework synthesis is currently the most commonly used approach in a guideline process and is a good choice when a question requires an understanding of complexity around feasibility and health system considerations. A QES of the barriers and facilitators to the implementation of lay health worker (LHW) programmes to improve access to maternal and child healthThis QES used a pre-existing framework .http://www.stir.ac.uk/emerge/).46Transparent reporting has emerged as an increasingly important consideration for evidence synthesis; historically it has not been done well.When undertaking a QES it is important to be able to assess the degree of confidence in which the key findings are a reasonable representation of the phenomenon of interest. The Grades of Recommendation, Assessment, Development and Evaluation-Confidence in the Evidence from Qualitative Reviews  approachGRADE-CERQual provides a transparent and systematic framework containing four components for assessing how much confidence to place in key findings: (1) the methodological limitations of the individual qualitative studies contributing to a review finding; (2) the coherence of the review finding; (3) the adequacy of data supporting a review finding; and (4) the relevance to the review question of the individual studies contributing to a review finding. A fifth component, dissemination (or publication) bias, may also be important and is being explored.The use of GRADE-CERQual is particularly helpful when undertaking QES for guideline development of complex interventions/systems. As its approach is congruent with other GRADE approaches it can be easily integrated into decision-making processes. Its use can enable QES to address a range of issues of complexity, a process vital to integrating qualitative evidence within EtD frameworks, including establishing which outcomes are important to stakeholders; the acceptability and feasibility of interventions along with any unintended consequences of interventions; and key factors to consider regarding implementation.48QES has a key role to play in the development of guidelines for complex interventions. This paper provides a summary of what QES is, how it can contribute to systematic reviews and guidelines of complex interventions, and provides a series of options for QES methods to support guideline developers in making informed decisions depending on the type of complexity-related question being asked.


Background: In 1997, the pursuit of greater accountability and effectiveness in humanitarian response prompted a multi-stakeholder collaboration to develop a set of indicators and standards to guide humanitarian practitioners, published later in the form of the Sphere Handbook. Twenty years after the first edition of the Handbook was developed, and in order to guide the 2018 revision, an assessment of the evidence base for current Water, Sanitation and Hygiene (WASH), Food Security and Nutrition, and Health Action indicators, as compared to evidence collated by the 2015 LSHTM Humanitarian Health Evidence Review (HHER), was conducted.Methodology: In order to assess the utility of the Sphere indicators as a tool with which to monitor and evaluate humanitarian activities, indicators from the WASH, Food Security and Nutrition, and Health Action chapters of the Sphere Handbook were analysed and classified according to the SMART criteria. Each indicator was then assessed based on existing evidence related to the effectiveness of humanitarian health interventions as compiled in the HHER.Results: Of the 159 Sphere indicators intended to guide humanitarian response, only 2 met all of the SMART criteria. The remaining 157 did not provide any time indication for the measurement of the indicator. Furthermore, only 11 standards (23%) and 14 indicators (8%) are supported in part by 33 studies identified in the HHER. Less than one third of studies captured by HHER that explore interventions related to WASH, nutrition, or health could be linked to existing Sphere indicators.Conclusion: It is not possible to adequately link the 2011 Sphere indicators and standards to their sources in their current constitution, and they are not sufficiently evidence-informed. In the absence of clear measurement definitions, they do not provide necessarily detailed guidance. While recognising that a number of indicators have emerged as a combination of empirical evidence, expert experience, and “common sense”, a focus on fewer indicators, each better defined, is likely to enhance the practical application of the Sphere Handbook in humanitarian settings. Evidence-Informed Humanitarian Response & The Sphere Standards,The pursuit of effectiveness and ethical practice in humanitarian health response, coupled with demands for improved accountability, have prompted calls to improve the evidence base for humanitarian interventions 1Evidence-informed decision-making in humanitarian crises is now recognised as a priority by humanitarian practitioners ,9,10,8,10,12,9,The Sphere Project is responsible for the development and periodical update of the Sphere Handbook, which comprises both a Humanitarian Charter and Minimum Standards in Humanitarian Response 8At its inception, the Sphere Project identified a set of minimum standards related to four key lifesaving sectors: water supply, sanitation and hygiene promotion (WASH); food security and nutrition; shelter, settlement and non-food items; and health action. The minimum standards have been described as ‘evidence-based’ and are intended to reflect ‘sector-wide consensus on best practice in humanitarian response, derived from the principle that all crisis-affected people have a right to a dignified life’ Prior to the fourth revision of the Sphere Handbook, a survey commissioned by Enhancing Learning and Research for Humanitarian Assistance (ELRHA) and conducted in collaboration with the Sphere Project was conducted to assess knowledge of the Handbook and the extent of its contemporary use, along with views on its structure and content Table 1). These three chapters were chosen as they are closely comparable with evidence synthesised in the HHER. Each indicator was classified as follows: SMART criteria met (green); SMART criteria met with supporting guidance notes and / or appendices (yellow); not SMART (red). For the purpose of this analysis, the “R” component was interpreted either as relevant, or realistic. This expanded definition was adopted as a number of the Sphere indicators may be unrealistic, or only possible to measure in very specific settings such as in small, well organised refugee camps. While it is clear that humanitarian assistance is intended to reach all crisis-affected people, it is rarely realistic to fully achieve indicators that use language such as “all users”, “all staff”, “all disaster-affected people”, “all targeted beneficiaries”, “at all times”, and “no cases of health hazards”.In order to assess the utility of the Sphere indicators as a tool with which to monitor and evaluate humanitarian activities, indicators from the WASH, Food Security and Nutrition, and Health Action  chapters of the Sphere Handbook were analysed and classified according to the SMART criteria  3Once matched, the following information was provided for each study that provided evidence to support a Sphere standard or indicator: author, year of publication, study design, study category, and a basic summary of key findings. Study categories were defined as category A if the study reported a statistical association between an intervention and health-related outcomes, and category B if the study measured changes in health-related outcomes, but did not report a statistical association.Classification of the Sphere IndicatorsThe WASH, Food Security and Nutrition, and Health Action  chapters of the Sphere Handbook report a total of 48 standards and 159 associated indicators, comprising 13 minimum standards and 58 indicators for WASH, 18 minimum standards and 63 indicators for Food Security and Nutrition, and 17 minimum standards and 38 indicators for Health Action.Only two indicators  of the 159 indicators report a loosely time-bound element: that assessment should take place following completion of a measles campaign for the measurement of measles and vitamin A coverage; and once routine Expanded Programme of Vaccination (EPI) services have been re-established for Diphtheria, Pertussis and Tetanus (DPT) coverage. For ease of further analysis, “Time” was dropped from the SMART criteria, such that all of the remaining indicators was assessed against their Specific, Measurable, Attainable, and Relevant (SMAR) qualities.Fig. 1).There is a notable discrepancy between chapters in the way that indicators are constructed. More than half of the WASH  and the food security and nutrition  indicators can be categorised as “SMAR”, or “SMAR with guidance notes and/or appendices” with a larger proportion of “SMAR with guidance notes and/or appendices” for the food security and nutrition compared to the WASH chapter (19.0% versus 8.6%). In contrast, the health action chapter is supported by a much larger proportion of SMAR or SMAR with guidance notes and/or appendices indicators  . Very few of these studies provide evidence for the standards and indicators listed in the Sphere Handbook.Table 2). All 4 studies measured statistical associations between an intervention and diarrhoea (i.e. category A). While the included studies provide some evidence, they do not support fully the associated indicator. For example, a study on soap distribution and diarrhoeal disease does not include all “hygiene items”, while the study on bucket provision and diarrhoeal disease does not specify a size or number of buckets.The WASH chapter of the Sphere Handbook contains 13 minimum standards and 58 indicators. Of the 6 studies included in the HHER, 4 studies support 3 (5.2%) of the indicators included in the Sphere Handbook and 3 (23.1%) of the standards. Four studies support directly 3 of the indicators associated with two of the water supply standards, and one of the hygiene promotion standards (see Table 3). While it should be noted that food security was not included in the HHER, 6 of the included studies support 5 food security indicators. All of the studies provide evidence in direct support of the indicators and 7 measure a statistical association between intervention and health outcome , while the remaining paper measured a change in the prevalence of acute malnutrition but did not report a statistical association (category B). As with the evidence in support of the WASH indicators, the evidence only partially supports the selected Food Security and Nutrition indicators.The Food Security and Nutrition chapter of the Sphere Handbook contains 18 minimum standards and 63 indicators. Of the 77 studies included in the review, 8 provide evidence for 7 (11.1%) of the 63 indicators, and 5 (27.8%) of the standards (see Table 4). Two indicators related to measles and routine EPI vaccination are supported by some evidence related to the positive impact of the vaccination itself, but with no supporting evidence regarding the coverage that should be achieved. Of the 21 supporting studies, 12 measure statistical associations between interventions and health outcomes (category A), while 9 measure changes in health outcomes, but do not report statistical associations (category B).The Health Action chapter contains 17 minimum standards and 38 indicators . Of the 236 studies included in the review, 21 support to some extent 4 (10.5%) of the 38 indicators  chapters of the Sphere Handbook were assessed as being SMART. The 157 remaining indicators did not provide any time indication for the measurement of the indicator. Excluding time bound information, 97 of 159 indicators (61%) were defined as SMAR and thus can be used as complete measurement tools. According to the Sphere Project, indicators “are ‘signals’ that assist in determining whether a standard has been attained. They provide a way of measuring and communicating the processes and results of key actions”. As such, the way in which many of the current Sphere indicators are phrased represents a weakness in terms of their operational applicability as tools for effective monitoring and evaluation. Furthermore, discrepancies were noted between chapters: a larger proportion of SMAR indicators were found in the Health Action chapter compared to WASH and the Food Security and Nutrition chapters (82% versus 52% and 57% respectively). While described as ‘evidence-based’ ,These findings are broadly in keeping with other studies that have sought to both qualify and quantify the evidence base that informs humanitarian interventions 3The use of indicators is essential in assessing the impact of an intervention. The Sphere Project tend to focus on process indicators  or outcome indicators (such as clinic attendance) rather than impact indicators , which may raise fewer issues, as many such interventions have a vast literature detailing positive impact (for example measles vaccination or Vitamin A supplementation) The lack of evidence to support certain humanitarian interventions is largely attributable to challenges associated with the conduct of research in insecure settings, but also to the use of inappropriate methodologies and unsuitable study designs by many researchers attempting to investigate the effectiveness of humanitarian interventions In the absence of a strong empirical evidence base, the authors of this paper recommend a thorough process of consultations with experts, with a detailed description of the consultation process and rationale for decisions. Accordingly, the Sphere Project suggests that “evidence-based” includes not only scientific evidence but also expert opinion and sectoral consensus. Although we agree that expert opinion and consensus may establish the foundation for some indicators, we have not adopted the same definition for the purpose of this analysis The authors of this paper have some concerns related to the number of indicators  in the current Sphere Handbook. In 2011, the US Centers for Disease Control (CDC) developed the Measurement of Selected Sphere Indicators (MeSSI) project for humanitarian response Nevertheless, it is important to note that since its launch in 1997 the Sphere Project has had a tremendous influence on humanitarian practice by defining minimum standards and situating accountability as a core principle in humanitarian practice. As demonstrated by a survey conducted by the authors of this paper and published in a companion report Following an earlier evaluation of the Sphere Project in 2004, Van Dyke and Waldman expressed a need to revise the standards, clarify the difference between standards and indicators, and a need to rely more heavily on evidence Following the publication of the latest Sphere Handbook in 2011, the humanitarian community has acknowledged a series of new challenges. The number, intensity, and scale of humanitarian emergencies has changed in the last ten years Finally, it is important to note that the HHER only gathered published, quantitative evidence from crisis-affected settings. As such, not only did the HHER not recognise evidence that has emerged from expert consensus or “common sense” approaches, but it also did not capture evidence from stable settings, some of which has been applied in the development of the current Sphere standards and indicators.The Sphere Handbook was conceived in 1997 by a group of non-governmental organisations, in part to respond to the overall lack of accountability experienced during, and in the aftermath of, the Rwandan genocide in 1994. The Sphere Project developed from a recognition amongst humanitarian actors of the need for greater accountability and effectiveness in humanitarian response. Twenty years later, these concepts that underpin the Sphere Handbook remain as relevant as ever, in a time when humanitarian actors require up-to-date guidance to assist in their response to established and emerging issues, such as the management of non-communicable diseases in urban, middle-income contexts.This study has demonstrated that humanitarian initiatives such as the Sphere Project must make better use of existing evidence, and document all decisions made by experts, during the development and revision of humanitarian standards and indicators. The Sphere standards and indicators published in 2011 were not sufficiently robust nor adequately evidence-informed, and do not stand as incontestable guidance, in light of the lack of clear measurement definitions that leave room for interpretation. We hope that our recommendations for greater transparency in the basis for, and origin of, the humanitarian standards and indicators, and a more refined selection of core SMART-compliant indicators, will be addressed in the next edition of the Sphere Handbook, due to be published in 2018. These recommendations, and outputs from the many expert consultations held worldwide, have the potential to reaffirm the relevance of the Sphere Handbook as one of the leading sources of technical guidance for humanitarian response.Karl Blanchet: karl.blanchet@lshtm.ac.ukThe authors declare no competing interests. The study funding source had no role in the analysis of the data, or the publication of results.All data used in this review is cited in-text.


We have found that the color change of a ((4-MPBA + AuNPs) + H2O2) mixture caused by H2O2 is more sensitive than that of a ((4-MPBA + H2O2) + AuNPs) mixture. For the former mixture, the color changes obviously with H2O2 concentrations in the range of 0~0.025%. However, for the latter mixture, the corresponding H2O2 concentration is in the range of 0~1.93%. The mechanisms on the color change originating from the aggregation of AuNPs occurring in the two mixtures were investigated in detail. For the ((4-MPBA + H2O2) + AuNPs) mixture, free 4-MPBA is oxidized by H2O2 to form bis(4-hydroxyphenyl) disulfide (BHPD) and peroxoboric acid. However, for the ((4-MPBA+AuNPs) + H2O2) mixture, immobilized 4-MPBA is oxidized by H2O2 to form 4-hydroxythiophenol (4-HTP) and boric acid. The decrease in charge on the surface of AuNPs caused by BHPD, which has alarger steric hindrance, is poorer than that caused by -4-HTP, and this is mainly responsible for the difference in the aggregation of AuNPs in the two mixtures. The formation of boric acid and peroxoboric acid in the reaction between 4-MPBA and H2O2 can alter the pH of the medium, and the effect of the pH change on the aggregation of AuNPs should not be ignored. These findings not only offer a new strategy in colorimetric assays to expand the detection range of hydrogen peroxide concentrations but also assist in deepening the understanding of the aggregation of citrate-capped AuNPs involved in 4-MPBA and H2O2, as well as in developing other probes.The difference in gold nanoparticle (AuNPs) aggregation caused by different mixing orders of AuNPs, 4-mercaptophenylboronic acid (4-MPBA), and hydrogen peroxide (H A well-2+ ,11, ATP 2+ , and dop2+ .2O2. For these probes, the selective and efficient reaction between the boronic acid group of 4-MPBA and H2O2 can form 4-hydroxythiophenol (4-HTP) [2O2produced from the oxidation of glucose by the glucose oxidase immobilized by PSA. Based on the aforementioned blue-to-red color change of AuNPs, PSA determination could be achieved [2O2 forms p-benzenediol to result in the dis-aggregation of aggregated BDBA/AuNPs, the electrochemical and colorimetric assays of hydrogen peroxide could also be constructed [2O2 with 4-MPBA adsorbed on the surface of a gold mirror, H2O2 or the glucose selectively bound to 4-MPBA could be detected using surface-enhanced Raman spectroscopy (SERS) [2O2 and be coupled with glucose oxidase (GOx) to achieve the selective detection of glucose [2O2 to yield a change of pH in a range of 2 to 6, which results in a steady-state change in the electrochemical potential. Based on this finding, a potentiometric hydrogen peroxide probe was constructed [2O2 have been widely investigated, the difference in the aggregation that occurs in ((4-MPBA + AuNPs) + H2O2) mixtures and ((H2O2 + 4-MPBA) + AuNPs) mixtures has so far not been reported.For these methods, some probes are based on the reaction of4-MPBA/AuNPs with H (4-HTP) ,15,16, wachieved . Based ostructed . By emply (SERS) . Similarstructed . Evident2O2 in inducing AuNP aggregation. Herein, we describe not only the two different approaches to induce aggregation of AuNPs involved in 4-MPBA and H2O2 but also, especially, their corresponding mechanisms. The results indicate that the difference in the concentration range of hydrogen peroxide in AuNP aggregation is mainly related to the difference in the reaction of H2O2 with free and immobilized 4-MPBA. In the mixture of ((4-MPBA + AuNPs) + H2O2), the immobilized 4-MPBAis oxidized by H2O2 to form 4-hydroxythiophenol (4-HTP). The change of 4-MPBA to 4-HTP makes the loaded charge on the surface of AuNPs decrease, resulting in the aggregation of AuNPs. In the mixture of ((H2O2 + 4-MPBA) + AuNPs), however, the free 4-MPBA is oxidized by H2O2 to form bis(4-hydroxyphenyl) disulfide (BHPD), and the immobilization of BHPD with bigger steric hindrance onto surface of AuNPs is more difficult than that of 4-HTP. This difference makes the mixture of ((4-MPBA + AuNPs) + H2O2 more sensitive to the aggregation of AuNPs caused by H2O2 compared with the mixture of ((H2O2 + 4-MPBA) + AuNPs). In addition, some details in the change of pH during the reaction for the two mixtures have also been revealed. The new findings should assist in expanding the detection range of H2O2 concentrations by AuNP-based colorimetric assays. Additionally, the revealed mechanisms should not only assistin deepening the understanding of the physical and chemical behavior of the system containing AuNPs, 4-MPBA, and H2O2, but also have a significant positive effect on developing new AuNP-based probes.Interestingly, for the two mixtures, we found that there is a great difference in the concentration range of H4·4H2O, purity ≥ 99.9%), hydrogen peroxide , and absolute ethanol (purity ≥99.99%) were obtained from Sinopharm Chemical Reagent Co., Ltd. . Trisodium citrate (AR) and potassium hydroxide  were received from TIANLI Chemical Reagents Ltd. . All reactants were used without further purification. Milli-Q water was used in all experiments. All used glassware was treated with aqua regia, rinsed in Milli-Q water, and oven-dried prior to use.4-Mercaptophenylboronic acid  and 4-hydroxythiophenol (4-HTP) were purchased from Sigma Aldrich . Tetrachloroauric (HAuCl4 (25 mM) aqueous was injected into a boiling solution of 150 mL sodium citrate (2.2 mM), and then the solution was kept boiling for 10 min. The color of the solution changed from yellow to bluish gray and then to soft pink. After the solution was cooled down to 90 °C, a 2 mL solution was drawn, and then the rest of solution was used as the seed solution . Then, 1mL HAuCl4 solution(25 mM) was added into the seed solution and maintained at a temperature of 90 °C for 30 min, and this process was repeated twice. After the reaction was quenched by an ice-water bath, AuNPs with ∼20 nm were obtained. The concentration of the final AuNPs was approximately the same as the seed particles (∼3 × 1012 NPs/mL). The citrate-stabled AuNPs were synthesized via previously reported methods . Briefly2O2, and AuNPs, some related reactive conditions were selected, as shown in To investigate the interactions among 4-MPBA, H13C, 1H, and 11B NMR (nuclear magnetic resonance) spectra were monitored by a JNE-ECZ400S/L1 Nuclear Magnetic Resonance Spectrometer . Raman measurements were performed on an in Via Raman microspectrometer  with 532 nm laser excitation. Transmission electron microscopy (TEM) images were recorded on a JEM-2100 system  with an accelerating voltage of 200 kV. The effective surface charge on4-MPBA/AuNPs in the different conditions shown in α X-ray source (1486.71 eV of photons). Further details can be found in the UV-visible spectra were acquired with a Lambda 35 UV-Vis Spectrometer . The The change in UV-Vis spectra of citrate-capped AuNPs with the change in concentration of 4-MPBA is shown in Combining these reports in the literature with our experimental results, we believe that the aggregation of 4-MPBA/AuNPs is mainly attributed to the decrease of electrostatic repulsive force. In particular, we found that the mixture of the well-dispersed citric acid-capped AuNPs and well-dispersed 4-MPBA/AuNPs also remains well dispersed for a long time, further implying that the reaction between 4-MPBA and citric acid scarcely occurred. This conclusion, i.e., that the aggregation of 4-MPBA/AuNPs is actually attributed to the weakened electrostatic interaction, will be proved again in following experiments. 2O2) and Mixt.2 (a lower ratio of 4-MPBA to H2O2).Mixt.1 is a series of mixtures where the given amounts of 4-MPBA and AuNPs were first mixed then followed by the addition of different amounts of H2O2, while Mixt.2 is a series of mixtures that given amounts of 4-MPBA was first mixed with different amounts of H2O2 followed by the addition of a given amount of AuNPs. 2O2 reacts with the immobilized 4-MPBA molecules. As displayed in 2O2 in the 4-MPBA/AuNP solution, besides the almost constant peak around 523 nm, a new absorbance peak gradually appears between 600 to 900 nm, and the solution color visibly changes from ruby red to blue. These results suggest that the aggregation of AuNPs enhances with the increase of H2O2, which is further proved by TEM images , and this change is responsible for the aggregation of 4-MPBA/AuNPs. To verify this extrapolation, in the UV-Vis spectra of Mixt.4, the change in the UV-Vis spectra of the AuNP solution in the presence of different amounts of 4-HTP was recorded . Apart from the decrease in charge density, hydrogen bonding is likely another factor in enhancing the interaction between 4-HT and AuNPs. The phenol groups are expected to be partially dissociated at around pH 10. The hydrogen bonding between the dissociated phenolate group and the undissociated phenol group is stronger than that between undissociated phenols [It is well known that aryl boronate molecules can react selectively and efficiently with Hnol form . Here, irecorded . Comparerecorded , even un2O2 in a lower ratio of 4-MPBA to H2O2, and then a given amount of AuNPs was separately added. In these mixtures, 4-MPBA molecules are first free and oxidized by H2O2, and then the products interact with AuNPs. The UV-Vis spectra of Mixt.2 are shown in 2O2 is shown in 2O2, and the solution color visibly changes from ruby red to blue. However, compared with Mixt.1, the concentration of H2O2 that induces the color change of solution is remarkably higher in Mixt.2. This difference could also be seen in the comparison of 2O2 in Mixt.1 is similar to that caused by 1.64% H2O2 in Mixt.2. The obvious color change of Mixt2is with aH2O2 concentration in the range of 0~1.93%. In principle, this concentration possesses relativity, because it depends on the ration of AuNPs to 4-MPBA. Here, this concentration is only to show the effect of H2O2 concentration on the trend in the color change of the mixture (AuNPs-4-MPBA-H2O2). However, for Mixt.1, the corresponding H2O2 concentration is in the range of 0~0.025%. This difference is explained in the next section. For Mixt.2, 4-MPBA was first mixed with H2O2 have been reported, to our knowledge, it has rarely been reported with systematical characterization of products formed in the reaction. Here, the main products formed in the reaction between 4-MPBA and H2O2 were characterized.Although many colorimetric probes based on the aggregation of AuNPs involving 4-MPBA and H2O2 for the two mixtures that contain different ratios of 4-MPBA to H2O2 in the absence of AuNPs. For the mixture with the higher ratio of 4-MPBA to H2O2 (as similar to Mixt.1), the pH gradually increases with the increase of H2O2 content  to form 4-HTP (pKa = 10) and boric acid (pKa = 8.9) [2O2 is not enough to continue the reaction because of the stoichiometric coefficient for the reaction of 4-MPBA with H2O2. Thus, for the mixture with a higher ratio of 4-MPBA to H2O2, the pH of the solution increases with H2O2 content. However, for the mixture with the lower ratio of 4-MPBA to H2O2  disulfide (BHPD) (pKa = 10) [2O2 to form peroxoboric acid ((HO)2BOOH) with a stronger acidity (pKa = 5.7) [ content A. In con of H2O2 B. For tha = 8.9) . Althoug to H2O2 B, besideKa = 10) ,34, and a = 5.7) ,35. Alth2O2 was testified using 11B NMR spectroscopy (3 appears and progressively strengthens [3BOOH−1 or (HO)2B(OOH)2−1 gradually increases and then decreases [The formation of boronic acid and BHPD in the mixture containing excess of Htroscopy . From Fiengthens . Additioecreases . This reecreases .13C and 1H NMR spectroscopy. 13C and 1H spectra of the reaction solution of 4-MPBA and H2O2 in the late reaction period. For the mixture of H2O2 and 4-MPBA, two peaks at 127.2 ppm and 134.7 ppm attributed to the primary carbon of benzene ring of 4-MPBA decreases [More importantly, the formation of BHPD was also testified by using ecreases , while tecreases ,40  related to hydrogen atoms in 4-MPBA almost disappear to be replaced by the characteristic peaks  of BHPD [2O [These results are consistent with the finding shown in the corresponding  spectra B. After  of BHPD ,40. The BHPD [2O . It is wBHPD [2O .2O2 (2O2 (2O2 (0.012%)  [All above results indicate that the reaction between 4-MPBA and He thiols ,46,47 ane thiols ,48,49,50alcohol) ; however2O2 (see −1 (νCC + δCH), 1009 cm−1 (γcc + γccc), 641 cm−1(νC–S) [−1 (νCH + νCS + νCC) [−1(νS–S), and 499 cm−1(νOBO) [−1 (νSH), 1369 cm−1 (νBO),1186 cm−1 (βCH + βBOH), 907 cm−1 (βCSH), 756 cm−1 (γCH), and 631 cm−1 (νCS) [2O2 can form 4-HTP and BHPD. This conclusion was also proven by the XPS result shown in −1 (δBOH), 879 cm−1 (νS(BO3)), and 499 cm−1 (δOBO) [−1 is confidently assigned to the stretching mode of the peroxide bond (O-O) [Interestingly, an insoluble white precipitate was observed during the reaction of 4-MPBA and H2O2 see . Raman s−1(νC–S) , 1072 cmS + νCC) , 524 cm−−1(νOBO) , being a1 (δOBO) ,58, and nd (O-O) ,60, indi2O2, regardless of the 4-MPBA firstly being mixed with AuNPs  and the mixture of ((H2O2 + 4-MPBA) + AuNPs)has been found for the first time, and the corresponding mechanisms were investigated. Based on the experimental results, the following conclusions can be drawn:The difference in the aggregation of AuNPs occurring in the mixture of ((4-MPBA + AuNPs) + H2O2 + 4-MPBA) + AuNPs), the color change of the mixture of ((4-MPBA + AuNPs) + H2O2) is more sensitive to H2O2, and this diversity that stems from the reaction of free and immobilized 4-MPBA with H2O2 is different. For the mixture of ((H2O2 + 4-MPBA) + AuNPs), free 4-MPBAis oxidized by H2O2 to form BHPD with greater steric hindrance and peroxoboric acid with stronger acidity. However, for the mixture of ((4-MPBA + AuNPs) + H2O2), the immobilized 4-MPBAis oxidized by H2O2 to form 4-HPT and boric acid. These differences make the mixture of ((4-MPBA + AuNPs) + H2O2) more sensitive to the aggregation of AuNPs caused by H2O2 than the mixture of ((4-MPBA + H2O2) + AuNPs).(1) Compared with the mixture of ((H(2) The aggregation of the citrate-capped AuNPs in the two mixtures mainly stems from the change in the charge density on the surface of AuNPs. 2O2 can affect the pH of the medium. The effect of this pH change on the aggregation of AuNPs should not be ignored. (3) The formation of boric acid or peroxoboric acid in the reaction between 4-MPBA and H2O2 detection but also assist in deepening the understanding of the aggregation of citrate-capped AuNPs involved in 4-MPBA and H2O2. Additionally, based on our new results, some possible methods in the determination of specific target analytes will be developed. For example, the detection of hydrogen peroxide produced from the reaction of glucose oxidase and glucose can be used to determine glucose; melamine could be determined based on the fact that the consumption of melamine combined with H2O2 could decrease the concentration of H2O2 and cause a change in the aggregation of 4-MPBA/AuNPs. In principle, the 4-MPBA/AuNPs system could be used to determine some specific substances that are related to the formation or consumption of H2O2.These findings not only offer a new strategy in colorimetric assays to respectively meet sensitivity and broad ranges of H


Evidence-based public health (EBPH) practice, also called evidence-informed public health, can improve population health and reduce disease burden in populations. Organizational structures and processes can facilitate capacity-building for EBPH in public health agencies. This study involved 51 structured interviews with leaders and program managers in 12 state health department chronic disease prevention units to identify factors that facilitate the implementation of EBPH. Verbatim transcripts of the de-identified interviews were consensus coded in NVIVO qualitative software. Content analyses of coded texts were used to identify themes and illustrative quotes. Facilitator themes included leadership support within the chronic disease prevention unit and division, unit processes to enhance information sharing across program areas and recruitment and retention of qualified personnel, training and technical assistance to build skills, and the ability to provide support to external partners. Chronic disease prevention leaders’ role modeling of EBPH processes and expectations for staff to justify proposed plans and approaches were key aspects of leadership support. Leaders protected staff time in order to identify and digest evidence to address the common barrier of lack of time for EBPH. Funding uncertainties or budget cuts, lack of political will for EBPH, and staff turnover remained challenges. In conclusion, leadership support is a key facilitator of EBPH capacity building and practice. Section and division leaders in public health agencies with authority and skills can institute management practices to help staff learn and apply EBPH processes and spread EBPH with partners. Evidence-based public health (EBPH) practice involves complex processes to improve population health and reduce disease burden –3. ExampThe Centers for Disease Control and Prevention (CDC) and other federal agencies increasingly require the use of evidence-based approaches when funding population-based chronic disease prevention and control units in state public health departments to fund and support local implementation. In chronic disease prevention, many of the evidence-based interventions promoted by The Community Guide and CDC, such as those to reduce tobacco use or increase physical activity opportunities, are multilevel and involve complex system-wide and/or environmental and policy changes . Such chOrganizational structures and processes can facilitate capacity building for EBPH. Leadership commitment to EBPH is consistently described as a key facilitator in literature reviews from public health, healthcare, business, and qualitative studies with local health departments in Canada and state injury prevention agencies in Australia , 10–14. The purpose of this multi-state qualitative study was to identify facilitators of EBPH capacity building in state health department chronic disease prevention and management units.Interviews were conducted in 2016 as part of a larger multi-year project. The purpose of the larger study was to better understand how university-based applied researchers could support state health departments to enhance capacity for evidence-based chronic disease prevention. The multi-year study was a group randomized trial with state health department chronic disease units (states) randomly selected and assigned to receive study team EBPH training and follow-up support (six states) or receive links to electronic resources for EBPH and participate in data collection (six states), with opportunity to receive study team training after data collection. Methods and pre-post survey findings from the larger study are reported elsewhere –20. WhilA purposive sample of interview participants was selected by the chronic disease directors in the 12 states in collaboration with the study team. Interview participants were mostly chronic disease unit  leaders and program managers. The respondents were often three to five layers below the state health officer. A few managers working cross-agency in quality improvement or performance management were also interviewed. After interview participants were invited by email and provided informed consent, a one-hour interview appointment was set for a later date, allowing further opportunity to decline at any time. Interviews were conducted in 2016 by phone by the study team  and ranged from 45 to 60 min in length. LB interviewed individuals with whom PA had worked during the study; PA interviewed others.The structured interview guide contained open-ended questions on activities of chronic disease units to support EBPH capacity building and application, internal and external influences, facilitators, challenges, and recommendations for the future. The first question was “how does your work unit use management practices to support evidence-based processes”. Participants were also asked to describe “the work unit environment as it relates to using evidence-based processes”, “any additional evidence-based process supports at the division or agency level”, acceptance of practices intended to support EBPH, what facilitated getting supportive practices in place, challenges encountered and how challenges were addressed, and “supports and expectations created for external partnering organizations for evidence-based processes”.Each phone interview was audio-recorded with participant permission and transcribed verbatim. Each de-identified transcript was independently coded in NVIVO 10 qualitative software by two study team members who then met to reach consensus on any disagreements in text blocks and codes . QueriedFifty-one of 54 invited state health department managers from 12 states completed 45–60-min phone interviews in 2016. Most (74%) participants were women, 31% held a public health graduate degree, and 37% had a master’s or doctorate degree in another field. Participants had worked in their positions an average of 5.9 years, in their agency 12.7 years, and in public health for 20.1 years. Participants directly supervised an average of 8.3 employees. At the time of the interviews, four of the 12 state health departments were accredited by the Public Health Accreditation Board, four were actively preparing to apply, two had temporarily abandoned preparations due to competing priorities and/or changes in leadership, and two had recently started preparations.In addition to the “constant drum beat” of federal funding and national accreditation requirements for evidence-based approaches, four themes emerged as key facilitators to building capacity for integrating EBPH into day-to-day practice: leadership support; incorporation of EBPH into agency structures and processes; commitment to professional development and hiring of staff with training and/or experience in EBPH; and external partner relationship building, training, and technical assistance. In addition to budget cuts and funding uncertainty, main challenges discussed by participants were lack of time; lack of external political will or support for EBPH; and staff turnover. Interview findings mapped onto the EBPH capacity building framework shown in Fig. Most participants discussed section and division leadership support as key levels of support that furthered EBPH. In most states, section and division leaders had to advocate for EBPH both up and down the agency hierarchies. In the two states in which participants described their agency-wide leaders as active drivers of EBPH, participants viewed such top-down support and requirements as crucial. In the other states, top agency leader nods of encouragement or permission to proceed were seen as beneficial but not essential to moving forward within sections or divisions. Section leaders were viewed as the central EBPH role models, but some program managers or section leadership team members also served as EBPH champions.“Leadership modeling” involved far more than just valuing EBPH and encouraging it. Section or division leadership support meant being a “key driver”, “role model”, “champion” of EBPH, and having “the vision to see it move forward”. “Staff seeing that she was excited about this was really, really helpful…seeing her promote this has been really great.” Another participant noted the section leader “has given us energy that we need to feel comfortable and competent.” “Ability to speak to the evidence, and talk about evidence evaluation, and changing programs according to what you find in evaluation, it helped us as we wrote a new DOH strategic plan.” “To have a leader who was sold on it [EBPH] and was continuing to bring it up and lead by example, was an important contributor to why it got incorporated more.”The main way leaders showed their support of EBPH was creating “continued conversation” and regularly asking for evidence in meetings. Leaders would ask “Well, is that evidence-based? What’s the science behind that idea or that proposed objective?” “She wants to know, do we know that this is something that will work, or can work, and what’s going to back that up? So are we making decisions based on the best evidence that we have?” “How do you know that you’re making a difference? What data sources do you have that could track your success? And how do you know you’re reaching the people you intend to reach?” “Part of the way he shows his support is by communicating about it and also by making specific requests when we present potential decisions…and so he has something to present to his constituents and his leadership”.Leaders provided “space” for EBPH and a supportive organizational environment. Leaders gave program managers and staff “permission”, time, and “room” to find and think through the evidence, “and to use that information as we are developing programs, developing policies.” Leaders ensured that “we allocate resources efficiently, responsibly, transparently, and we know that’s through using evidence-based strategies and programs, we don’t like to veer off that pathway”. EBPH is “ingrained”, “understood”, “part of the culture”, “inherent in how we work on program efforts”, “the way we do business”.“We use evidence-based practices because that’s what good public health is.”“Climate has changed to the point where people [staff] actually get upset if we aren’t doing something that’s evidence-based.”In addition to leadership support, managers emphasized the importance of developing documented systems, structures, and procedures to ensure EBPH incorporation became permanent. “There’s a lot of culture here around documenting processes and testing to see if they can be improved.” At least two state health departments restructured their formal administrative units to better share information and support EBPH across program areas. All 12 participating state health departments instituted regular meetings across chronic disease prevention and/or broader units to provide EBPH messaging and share information, plans, and successes. More than half of the states capitalized on agency-wide development or expansion of centralized data systems to increase internal and partner access to data and intervention evidence and share performance measures. Half of the chronic disease units incorporated EBPH learning and practice objectives into employee evaluations within their states’ existing performance review systems. Managers described increased commitment to hire evaluators and epidemiologists to support EBPH, and to hire program staff trained and/or experienced in EBPH. Several managers formalized this commitment by including expectations for EBPH in job descriptions and interview questions. Each chronic disease unit transitioned to requiring EBPH in contracts that funded in-state partners.“If you don’t change the systems and structures down to the level we were talking about, about changing the questions that are asked on a proposal…then the change is dependent on that person [leader] being there and continuing to be inspiring.”Leaders realized that ongoing periodic training was also needed to ensure staff members were well prepared for EBPH. All participating states provided or hosted brief EBPH-related overview and topical skills trainings for their chronic disease prevention staff to some extent, as well as quality improvement and/or performance management training for staff agency-wide. “Adequate training in evidence-based practice is most useful, without that we can’t really move forward at state or local level.” Half of the states initiated new employee orientation to EBPH. Managers acknowledged state health department accreditation efforts had provided impetus and agency support for EBPH workforce development and improved documentation. “So we are all much more in tune to documenting what we do and making sure we understand why.”The managers emphasized the importance of building and maintaining relationships with external partners while promoting EBPH practice through contracts. Managers said they and their state-level staff needed “the ability to develop strong, healthy, productive relationships with the people around the state that are doing the work.” Interview participants stressed the importance of compromise, listening, getting input, building trust, and being transparent about decision-making processes. They also spoke about avoiding being directive or pushing too hard or fast, instead “needing to be thoughtful and realistic, it brings a larger majority along together”. It was important “to listen to how things seem to be going according to our partners’ perspectives, what they see as barriers or challenges, and then to be responsive to that.” “Once you get their trust and they’re [partners] onboard, they understand that what’s evidence-based is going to make the biggest difference in their communities.”“Sometimes partners are very passionate and advocate for their particular issue that they want addressed that may not necessarily be what the evidence is showing as the biggest issue…You have to balance, think about the relationships, and be able to address the relationships.”“And so what we work to do is to be really clear on how we’re establishing priorities and what kinds of criteria we’re considering. And taking input and then reaching a compromise and letting people know that we value their input and we take it very seriously and take it to heart.”In addition to relationship building and maintenance, participants discussed the importance of EBPH training and technical assistance they provided to external partners. States provided multiple brief webinars, in-person partner trainings on program evaluation, grant writing, or other topics, and emailed notices of trainings provided by others. EBPH technical assistance was through one-on-one or small group phone calls and in-person visits. Technical assistance included program planning, discussion of contract menu options, guidance on program evaluation, orientation of new partners, review of “what went well, what didn’t go as well as hoped” and “open, honest dialogue with folks about how can we help you make this work in your community.” State health department staff then wrote EBPH objectives and menus of evidence-based strategies, which were incorporated into requests for in-state proposals and contracts.To sustain EBPH capacity and practice, managers emphasized the importance of documented agency structures and processes to make supports for EBPH practice permanent, documentation and use of common language for EBPH internally across program areas and with external partners, and ongoing refresher trainings. Managers also spoke about the importance of “continuing the conversation” about EBPH through “constant reinforcement of what is considered EBPH”, cross-program meetings to share EBPH examples and evaluation plans across program areas and provide EBPH reinforcement reminders, starting program planning with the evidence and data, and incorporating EBPH into employee performance evaluations.Four main challenges to EBPH emerged: (1) funding uncertainties or budget cuts, (2) lack of time, (3) lack of political will or support for EBPH, and (4) staff turnover. Participants attributed the time challenge to inadequate staffing levels and the extra time EBPH planning took. Staff turnover was a common frustration. “You get staff trained and they leave, so you lose that piece that was gained.” Managers viewed EBPH orientation of new staff and periodic brief trainings as partial solutions. Offering flex scheduling, learning opportunities, and resources needed for the work were strategies managers were using to hire and retain qualified staff despite non-competitive low pay. While managers in three state health departments said they enjoyed political support for EBPH, participants in the other states expressed frustration at sometimes being asked by agency or state political leaders to take approaches not grounded in evidence. Managers said competing priorities or “hot issues” sometimes put evidence-based chronic disease prevention aside. Lack of evidence in some program areas or with some population groups was also mentioned.Participant recommendations to further incorporate and sustain EBPH practice largely mirrored the findings covered above. Participants in 10 states recommended reinforcing an organizational climate supportive of EBPH. Managers stated this could be accomplished through establishment of EBPH as a foundational or guiding principle and increased incorporation of EBPH in goals and work plans, commitment to EBPH through formal EBPH accountability procedures, frequency of employee and contractor monitoring for EBPH application, communication about EBPH within the agency, and continued incorporation of EBPH in strategic planning. Participants recommended continuing education including ongoing EBPH orientation for new staff and training in program evaluation, leadership development training and mentoring, and training on how organizations change, benefits of organizational change, and staff roles and coping strategies in organizational change. “I think in order to keep it [EBPH] building and growing as you bring on new staff it has to be a part of orientation.” Participants recommended training sessions be recorded for later review, possibly in an interactive webinar format.To build EBPH capacity and supports, chronic disease directors and program managers in 12 state health departments emphasized the importance of section and division leadership support, creation of in-house procedures to make EBPH processes more permanent and less dependent on individual EBPH champions, ongoing workforce development in EBPH, and creation of EBPH expectations and capacity-building supports with external partners.Leadership support provided by chronic disease directors and division leadership to build EBPH capacity and practice included role modeling, consistently asking what the evidence was for each planned or proposed approach, creating a supportive work environment for EBPH, and giving staff time to obtain and digest evidence. Leadership support is considered a key component in other studies as well , 26–28. http://www.chronicdisease.org/). Section, bureau, and division managers also need flexibility to institute procedural changes such as those managers in this study described and to create environments supportive of EBPH [Leaders at several levels in public health agencies need leadership and management skill development opportunities and support . State a of EBPH , which wProcedural changes within public health agencies can help ensure application of EBPH processes, as discussed here and found in the literature. Participants in the present study cited leader and staff turnover, which is a documented problem , 32. To Workforce development for EBPH requires a long-term commitment and multi-faceted approaches , 35. In Provision of training and technical assistance with external partners is also essential to advance the work of state health department chronic disease units, since local partners both within and outside of the public health sector implement complex multi-level evidence-based approaches , 11, 37.In conclusion, leadership support at the section, bureau, and division levels is a key facilitator of EBPH capacity building and practice. As discussed by study participants, even if political or agency-wide leadership is lacking, section and division leaders with authority and skills can institute management practices to help staff learn and apply EBPH processes and spread EBPH to partners. Section and division leaders need training and support to do this. In addition to leadership support, individual and organizational EBPH capacity can be enhanced through ongoing training and technical assistance with staff and partners, use of information systems that cross program areas coupled with clear and transparent expectations for EBPH practice in internal documents and external requests for proposals and contracts.


If cross-sectional imaging techniques often disclose the presence of an accessory spleen, they seldom detect a wandering accessory spleen. This latter diagnosis can be challenging but important and derives great benefit from computed tomography with curved multiplanar and three-dimensional reconstructions displaying the long vascular pedicle connecting the small mass to the splenic vessels. We call this anatomical complex the “Jokari sign”, in reference to the ball-on-a-string racket game. The diagnosis of a wandering accessory spleen (WAS) may prove delicate. It is nevertheless most important in three clinical scenarios. First, the nodule can mimic a lymphadenopathy or an abdominal tumor, second, the WAS can occasionally trigger symptoms in case of torsion, rupture or hemorrhage, third, its existence must be recognized when the functional splenic tissue must be surgically resected.A WAS will essentially be identified on the basis of cross-sectional imaging techniques. The excellent spatial resolution of computed tomography (CT), in particular, enables a correct diagnosis based essentially on curved multiplanar and three-dimensional (3D) reconstructions.A 60-year old woman with a right breast neoplasm is presented to the Radiology Department for a thoraco-abdominal CT scan. The only anomaly displayed on the axial images is a well-marginated, 3 cm in diameter, enhancing mass at the level of the left upper abdominal quadrant between the spleen and the diaphragm. Although the lesion resembles an accessory spleen based on similar enhancement characteristics of the main spleen, a metastatic nodule is not entirely excluded Fig. .Since the patient underwent previous thoracic CT scans for recurrent pneumonia, we reviewed those displaying some upper abdominal axial images. The nodule was already visible but its location was different: it was then spotted anterior to the lower pole of the spleen, between the greater curvature of the stomach and the upper left colon Fig. .An examination of the thin slices of the last oncological CT reveals that the small mass is fed by an 18 cm-long thin vascular pedicle that we submit to curved multiplanar and 3D reconstructions. The obvious link between the nodule and the splenic vessels, a complex that we call the “Jokari sign”, enables us to give a correct diagnosis of a WAS Figs. .The spleen is an intra-peritoneal lymphoid organ weighing about 200 g usually located in the left upper abdominal quadrant under the rib cage. It is maintained in its position by two ligaments: the gastrosplenic ligament, which links the greater curvature of the stomach to the ventral face of the spleen, and the splenorenal ligament extending between the left kidney and the spleen, attaching the latter to the posterior abdominal wall. The spleen is more or less a tetrahedron whose shape is conditioned by the neighboring organs, among others, the diaphragm and the left kidney. Though it is most often unique and homogeneous, the spleen may display notches, even clefts, which are remnants of the fetal lobulation of the organ. These variants must be recognized in order not to be mistaken for expansive loco-regional lesions .Accessory spleens result from a failure of fusion of the splenic buds, during the fifth week of fetal life, in the dorsal mesogastrium . AccordiThe wandering spleen is a rare entity whose incidence is estimated at about 1.5% and where the organ is found outside its usual location. The etiology of this presentation results from a laxity or a maldevelopment of the splenic ligaments with, as a corollary, a ubiquitous splenic positioning in the abdomino-pelvic area depending on the length of the vascular pedicle , 7. MostThe WAS remains an extremely rare occurrence with only few cases described in the literature and in which an accessory spleen with a long vascular pedicle is mobile in the abdomino-pelvic cavity , 2, 8. TA WAS is an extremely rare entity which must nevertheless be recognized in the frame of oncological evaluations, during painful abdominal episodes or when a hemato-oncological surgery has been programmed.Its correct diagnosis is essentially based on CT, whose incomparable spatial resolution enables multiplanar and 3D reconstructions of the long vascular pedicle connecting the small mass to the splenic vessels or “Jokari sign”.The authors declare that they have no competing interests.


Staphylococcus, Bacillus, Lactococcus, Lactobacillus, Debaryomyces, and Aspergillus were identified as the predominant genera. Accordingly, 13 representative strains were selected from the dominant genera, and their BAs formation and degradation properties were evaluated. Finally, the results of fermented meats model experiment indicated that the Staphylococcus isolates including Staphylococcus pasteuri Sp, Staphylococcus epidermidis Se, Staphylococcus carnosus Sc1, Staphylococcus carnosus Sc2, and Staphylococcus simulans Ss could significantly reduce BAs, possessing the potential as the starter cultures to control the BAs in fermented meat products. The present study not only helped to explain the BAs accumulation mechanism in Chinese sausage, but also developed the candidates for potential BAs control in fermented meat products.Biogenic amines (BAs) in sausages represent a health risk for consumers, and thus investigating the BAs accumulation mechanism is important to control the BAs. In this study, the BAs profiles of 16 typical Chinese sausage samples were evaluated, and 8 kinds of common BAs were detected from different samples. As a whole, the BAs contents of the majority of Chinese sausage samples were within the safe dosage range, except that the total BAs and histamine concentrations of sample HBBD were above the toxic dosage levels. Furthermore, the bacterial and fungal communities of the Chinese sausage samples were investigated by high-throughput sequencing analysis, and  Biogenic amines (BAs) are mainly generated from amino acid decarboxylation by food-related microorganisms and are commonly considered as potential toxic nitrogenous substances in foods . The typChinese sausages are traditional fermented meat products in China. Due to their characteristic color, texture, and flavor, Chinese sausages have been popular with a long history in China . HoweverStaphylococcus was identified as the dominant genus , SCCD (Chengdu), GXWZ (Wuzhou), ZJHZ (Hangzhou), JXJGS (Jinggangshan), GDHP (Huangpu), HNXX (Xiangxi), HLJHEB (Haerbin), HBES (Enshi), ZJJH (Jinhua), JLCC (Changchun), HBBD (Baoding), GZZY (Zunyi), AHXC (Xuancheng), NMGTL (Tongliao), and JSRG (Rugao). Each sample was collected in three replicates, and stored at -20°C for further analysis.2HPO4 2 g/L, MgSO4 0.2 g/L, MnSO4 0.04 g/L, Tween 80 1 g/L, pH = 5.7), and SDB medium . Agar (1.5 wt%) was added to prepare the solid medium.The media used in this study included LB medium , MRS medium  following the manufacturer’s instructions. The purity of the genomic DNA was confirmed by the subsequent pyrosequencing analysis with 1% agarose gel electrophoresis. Primers 338F (ACTCCTACGGGAGGCAGCA) and 806R (GGACTACHVGGGTWTCTAAT) were designed according to the V3–V4 region of bacterial 16S rRNA gene. Primers ITS1F (CTTGGTCATTTAGAGGAAGTAA) and 2043R (GCTGCGTTCTTCATCGATGC) were designed based on the ITS1F-ITS2 region of the fungal internal transcribed spacer (ITS). After PCR and purification, a DNA library was constructed and run on the Miseq Illumina platform at Majorbio Bio-Pharm Technology Co., Ltd. .1, including richness estimators, Chao1 index, diversity estimators, and Shannon index. The number of operational taxonomic units (OTUs) (with >97% sequences similarity being defined as one OTU) was obtained by Usearch program (version 7.1) using furthest neighbor algorithm and established the phylogenetic tree with the relative abundances of OTUs. Taxonomy was assigned by the Silva Database Project classifier  with the sterile water. For each dilution, 200 μL sample solution was, respectively, plated onto LB plates, MRS plates with 20 g/L CaCO3 and SDB plates with 50 mg/L rifampicin. LB plates were incubated at 37°C for 24 h. SDB plates were cultured at 37°C for 48–72 h (depending on the strains), and MRS agar plates were incubated at 37°C for 48 h. And the colonies with different forms were selected for further analysis.Chinese sausage samples (5 g) were crushed and added with 45 mL sterile water. The mixtures were incubated at 37°C for 40 min in a rotatory shaker with 140 rpm. Samples were then serially diluted  following the manufacturer’s protocol, and the genomic DNA of fungi was extracted using a SDS-based DNA extraction method described previously . The 16ShdcA), tyrosine decarboxylase (tyrdc), ornithine decarboxylase (odc), agmatine deiminase (aguA and aguD) and lysine decarboxylase (ldc). The primers used in this study were listed in PCR amplification were performed to confirm the presence of BAs-related genes of histidine decarboxylase (Bacillus and Staphylococcus), MRS medium (Enterococcus and Lactobacillus) or SDB medium (Candida), and all the media were added with 1 g/L of histidine, tyrosine, tryptophan, phenylalanine, ornithine monohydrochloride, lysine, or agmatine sulfate salt. The BAs concentrations after 48 h incubating were determined. To evaluate the BAs degradation properties, the strains were cultured at 37°C for 12–24 h and then collected by centrifugation at 6000 ×g for 5 min. The cell pellets were washed with 0.05 mol/L phosphate buffer (pH = 7), re-suspended to reach OD600 at 0.8 in phosphate buffer (0.05 mol/L) containing 100 mg/L of histamine, tyramine, tryptamine, β-phenethylamine, putrescine, cadaverine, spermidine and spermine. The cell suspension was then cultured at 37°C for 48 h and the residual BAs in the suspension was determined. The phosphate buffer without cell pellets was applied as control. The BA-degradation rate was calculated asThe BAs production properties of different strains were characterized by assessing the biotransformation of precursors to corresponding BAs. The strains were cultured in 5 mL LB medium  to be inoculated into a 50 mL sterilized flask with 10 g of fresh pork slices containing 2% salt, 1% glucose and 4% sucrose. The microbe-meat mixture was incubated at 37°C for 7 days to analyze the total BAs, and the meat inoculated with equal volume of sterilized water was used as the control.The model fermented meat was constructed to evaluate the BAs-controlling properties of as-selected strains. In brief, the cells were inoculated into corresponding broth at 37°C for 12 h to reach ODA/B = 1:1; 3–20 min, A/B = 1:1 to A/B = 1:9; 20–29 min, A/B = 1:9; 29–32 min, A/B = 1:9 to A/B = 1:1; 32–35 min, A/B = 1:1.The BAs were extracted and pretreated according to the methods described previously ,b. The BAll analysis experiments were conducted at least three replicates. The difference significance was analyzed by one-way ANOVA method using the statistical software SPSS 20.0, and mean values were compared by Tukey’s HSD test at 5%.The BAs contents in different Chinese sausage samples were shown in After the quality control, a total of 1,351,248 high-quality 16S rRNA gene sequences and 1,490,880 high-quality ITS gene sequences were recovered from sixteen sausage samples. The Chao richness estimator and Shannon index were calculated based on 3% genetic distance for the samples, and the results are shown in Firmicutes was predominant bacterial phylum in most samples, particularly in NMGTL with up to 99.82% of the total sequences  with tryptamine, β-phenethylamine, putrescine, cadaverine, histamine and tyramine. The Candida genus was positively correlated (P < 0.05) with β-phenethylamine, cadaverine and histamine. The genera such as Enterococcus and Streptococcus, were commonly reported as BA-producers, while spearman analysis showed that they had no relationship with BAs formation. Due to the complexity of microbial communities, the correlation analysis might not reveal the accurate relationship between microbial communities and BAs. Therefore, it is necessary to isolate the representative strains from the dominant communities to evaluate their capabilities to produce and degrade BA, which will be more accurate to reflect the relationships between main strains and BAs.The relationships between microbial communities and BAs were also evaluated by spearman analysis . The genStaphylococcus, Bacillus, and Lactobacillus were major genera in most sausages samples, and Staphylococcus species were commonly used as the starter cultures in fermented meat products. Therefore, we mainly selected the isolates belonging to Staphylococcus, Bacillus, and Lactobacillus. We obtained 13 isolates, including Staphylococcus pasteuri (1 isolate), Staphylococcus epidermidis (1 isolate), Staphylococcus carnosus (2 isolates), Staphylococcus simulans (1 isolate), Bacillus subtilis (1 isolate), Bacillus amyloliquefaciens (1 isolate), Bacillus pumilus (1 isolate), Enterococcus faecium (3 isolates), Lactobacillus curvatus (1 isolate), and Candida metapsilosis (1 isolate)  .C. metapsilosis Cm and three E. faecium isolates were positive in tyrosine decarboxylase gene detection, and they also showed strong tyramine-producing abilities (L. curvatus Lc (L. curvatus Lc had the capacity to produce putrescine from ornithine (hdcA), lysine decarboxylase gene (ldc) and agmatine deiminase gene (aguA and aguD) using primers HdC1/HdC2, Cad2F/Cad2R, CadAf/CadAr, AgmSq1/AgmSq2, and AgD1/AgD2. Accordingly, most isolated strains showed no ability to produce histamine, cadaverine and putrescine from histidine, lysine and agmatine, respectively, and just low concentrations were detected from several strains. These results indicated that unknown amine acid decarboxylases or isoenzymes with low activities might exist in some strains, which will be further investigated in the future. On the other hand, more than 60% of the strains produced tryptamine and β-phenethylamine. Among the 13 isolates, S. epidermidis Se and S. simulans Ss showed no capability to generate BAs, and S. pasteuri Sp, B. subtilis Bs, and B. amyloliquefaciens Ba produced low concentrations of BAs, with high contents of BAs observed in the rest isolates.Common BAs-forming genes in 13 isolates were detected to evaluate their potential BAs-producing abilities, and their capabilities for biotransformation of amino acid precursor to corresponding BA were also measured. bilities . The ornvatus Lc , which arnithine . None ofStaphylococcus isolates exhibited relatively high degradation abilities for each BA.The 13 isolates were tested for their capabilities of degrading tryptamine, β-phenethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine. Most isolates were capable of degrading eight common BAs with different efficiencies . As a whStaphylococcus isolates showed high BAs-degradation abilities , which was probably due to the native microbes in meat. And the individual content of BA found in the meat model were indicated in S. pasteuri Sp, S. epidermidis Se, S. carnosus Sc1, S. carnosus Sc2, or S. simulans Ss, were reduced (S. epidermidis Se, S. carnosus Sc1, S. carnosus Sc2, and S. simulans Ss revealed relatively high abilities of inhibiting the BAs accumulation in model fermented meat.Fermentation of sausages is a complex process involving various microbes, thus we constructed a spontaneous fermentation meat model to investigate effects of the strains on BAs control. Above results showed that all the bilities . Moreoveproducts . Therefo reduced . In partExcess intake of BAs can cause various harmful effects, for example that histamine can lead to nausea, headache, hot fushes and skin rashes, and tyramine, β-phenylethylamine and tryptamine can cause migraine and hypertensive crises . HoweverFirmicutes and Ascomycota were the predominant phylum in bacteria and fungi, respectively. At the genus level, Staphylococcus, Bacillus, Lactococcus, and Lactobacillus were the dominant bacterial genera in most samples. Similar results were also reported that Staphylococcus and lactic acid bacteria were the representative genera in fermented meat products (Debaryomyces and Aspergillus were the predominant fungal genera in some sausage samples, and these fungi were also reported as the major genera in other meat products (Generally speaking, the accumulated BAs in fermented foods mainly depend on two sides, including the BAs formation by amino acids decarboxylases and the BAs degradation by amine oxidases, which were significantly affected by complex microbial communities . The marproducts . Debaryoproducts .Staphylococcus, Bacillus, Enterococcus, Lactobacillus, and Candida, which were commonly reported in fermented meat products (E. faecium Ef1, Ef2, Ef3 and C. metapsilosis Cm possessed the tyrosine decarboxylase gene, as well as the high tyramine-generating abilities. The ornithine decarboxylase gene was just detected in L. curvatus Lc, and identical conclusion was also obtained in biotransformation analysis, which was consistent with a previous study (E. faecium also showed high capacity of producing β-phenylethylamine, which was similar with previous researches (Staphylococcus isolates showed relatively high degradation abilities for all BAs. The results indicated that it was possible design of microbial-based solutions to reduce BAs content in fermented food (Staphylococcus were usually used as the starter cultures for sausages fermentation (Staphylococcus isolates on BAs accumulation were accessed in model fermented meat to select the potential starter culture for BA control. Interestingly, inoculation of S. pasteuri Sp, S. epidermidis Se, S. carnosus Sc1, S. carnosus Sc2, and S. simulans Ss could significantly reduce the BAs accumulation, and these Staphylococcus strains could be used as potential candidates for BAs control in fermented meat products. In previous studies, S. carnosus FS19 and Staphylococcus xylosus No. 0538 were reported as starter cultures to control the BAs accumulation in fermentation of meat products (According to the microbial community results, we screened thirteen representative strains from two typical sausage samples with significantly different BAs contents, including products . The BA us study . Exceptisearches . These sted food . Meanwhientation . Thus, eproducts , and thiStaphylococcus strains were confirmed to be efficient for BAs control in the fermented meat model. This study not only explained the microbial contribution to BAs accumulation in Chinese sausages, but also provided the potential starter cultures for BAs control in fermented meat products industry.In summary, this study evaluated the BAs profiles of 16 typical Chinese sausage samples, indicating the potential BAs-related safety risk in Chinese sausages. Based on microbial community analysis results, 13 representative strains were selected from the dominant microbial genera, and their contributions to BAs formation and degradation were explained. Moreover, five XW and LL designed the study. DZ and LR executed the experimental work. LL and DZ analyzed the data. XW contributed reagents and materials. LL, XW, ZW, SC, and LX wrote and revised the manuscript. All authors read and approved the final manuscript.LX was employed by the company Carollo Engineer, Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Venous ulcers are a common chronic problem in many countries especially in Northern Europe and USA. The overall prevalence of this condition is 1% rising to 3% in the over 65 years of age. Over the last 25 years, there have been many developments applicable to its diagnosis and treatment. These advances, notwithstanding healing response and recurrence, are variable, and the venous ulcer continues to be a clinical challenge.The pathogenesis of venous ulcers is unrelieved or ambulatory venous hypertension resulting mostly from deep venous thrombosis leading to venous incompetence, lipodermatosclerosis, leucocyte plugging of the capillaries, tissue hypoxia and microvascular dysfunction. It is not known what initiates venous ulcers. Triggers vary from trauma of the lower extremity to scratching to relieve itchy skin over the ankle region. Venous ulcers can be painful, and this condition presents an increasing burden of care. A systematic analysis of the role of technology used for diagnosis and management strongly supports the use of compression as a mainstay of standardised care. It further shows good evidence for the potential of some treatment procedures to accelerate healing. This article reviews the pathogenetic mechanisms, current diagnostic methods and standard care and its limitations. VLUs are among the most common chronic wounds presenting on the lower extremities and feet in man with prevalence up to 3% in the over 65 years of age in the UK  [s may be a logical first step to be followed by designed trials with adequate sample size to test the efficacy of specific nutritional supplementation.Guest et al.  reported1–1.59)] . This res. VLUs are the result of macro- and microvascular dysfunction, i.e. structural changes in the veins and tissues as well as haemodynamic changes which in skin breakdown over the ankles. Standardised care and mainstay of treatment for VLUs have been defined based on evidence. It is clear from the evidence that our management of VLUs must be improved and that suitable compression techniques for use in warmer countries as found in Asia and Africa need to be developed. There is also an unmet need for adjunct devices to speed wound healing.The purpose of this paper was to review the pathogenesis and evidence for treatment of VLU