Overcoming translational barriers impeding development of Alzheimer's disease modifying therapies.

PubMed

Golde, Todd E

2016-10-01

It has now been ~ 30 years since the Alzheimer's disease (AD) research entered what may be termed the 'molecular era' that began with the identification of the amyloid β protein (Aβ) as the primary component of amyloid within senile plaques and cerebrovascular amyloid and the microtubule-associated protein tau as the primary component of neurofibrillary tangles in the AD brain. These pivotal discoveries and the subsequent genetic, pathological, and modeling studies supporting pivotal roles for tau and Aβ aggregation and accumulation have provided firm rationale for a new generation of AD therapies designed not to just provide symptomatic benefit, but as disease modifying agents that would slow or even reverse the disease course. Indeed, over the last 20 years numerous therapeutic strategies for disease modification have emerged, been preclinically validated, and advanced through various stages of clinical testing. Unfortunately, no therapy has yet to show significant clinical disease modification. In this review, I describe 10 translational barriers to successful disease modification, highlight current efforts addressing some of these barriers, and discuss how the field could focus future efforts to overcome barriers that are not major foci of current research efforts. Seminal discoveries made over the past 25 years have provided firm rationale for a new generation of Alzheimer's disease (AD) therapies designed as disease modifying agents that would slow or even reverse the disease course. Unfortunately, no therapy has yet to show significant clinical disease modification. In this review, I describe 10 translational barriers to successful AD disease modification, highlight current efforts addressing some of these barriers, and discuss how the field could focus future efforts to overcome these barriers. This article is part of the 60th Anniversary special issue. © 2016 International Society for Neurochemistry.

Theoretical analysis of the rotational barrier of ethane.

PubMed

Mo, Yirong; Gao, Jiali

2007-02-01

The understanding of the ethane rotation barrier is fundamental for structural theory and the conformational analysis of organic molecules and requires a consistent theoretical model to differentiate the steric and hyperconjugation effects. Due to recently renewed controversies over the barrier's origin, we developed a computational approach to probe the rotation barriers of ethane and its congeners in terms of steric repulsion, hyperconjugative interaction, and electronic and geometric relaxations. Our study reinstated that the conventional steric repulsion overwhelmingly dominates the barriers.

Overcoming barriers to exercise among parents: A social cognitive theory perspective

PubMed Central

Mailey, Emily L.; Phillips, Siobhan M.; Dlugonski, Deirdre; Conroy, David E.

2017-01-01

Parents face numerous barriers to exercise and exhibit high levels of inactivity. Examining theory-based determinants of exercise among parents may inform interventions for this population. The purpose of this study was to test a social-cognitive model of parental exercise participation over a 12-month period. Mothers (n=226) and fathers (n=70) of children <16 completed measures of exercise, barriers self-efficacy, perceived barriers, and exercise planning at baseline and one year later. Panel analyses were used to test the hypothesized relationships. Barriers self-efficacy was related to exercise directly and indirectly through perceived barriers and prioritization/planning. Prioritization and planning also mediated the relationship between perceived barriers and exercise. These paths remained significant at 12 months. These results suggest efforts to increase exercise in parents should focus on improving confidence to overcome exercise barriers, reducing perceptions of barriers, and helping parents make specific plans for prioritizing and engaging in exercise. PMID:27108160

Overcoming barriers to exercise among parents: a social cognitive theory perspective.

PubMed

Mailey, Emily L; Phillips, Siobhan M; Dlugonski, Deirdre; Conroy, David E

2016-08-01

Parents face numerous barriers to exercise and exhibit high levels of inactivity. Examining theory-based determinants of exercise among parents may inform interventions for this population. The purpose of this study was to test a social-cognitive model of parental exercise participation over a 12-month period. Mothers (n = 226) and fathers (n = 70) of children <16 completed measures of exercise, barriers self-efficacy, perceived barriers, and exercise planning at baseline and 1 year later. Panel analyses were used to test the hypothesized relationships. Barriers self-efficacy was related to exercise directly and indirectly through perceived barriers and prioritization/planning. Prioritization and planning also mediated the relationship between perceived barriers and exercise. These paths remained significant at 12 months. These results suggest efforts to increase exercise in parents should focus on improving confidence to overcome exercise barriers, reducing perceptions of barriers, and helping parents make specific plans for prioritizing and engaging in exercise.

Open access for the non-English-speaking world: overcoming the language barrier

PubMed Central

Fung, Isaac CH

2008-01-01

This editorial highlights the problem of language barrier in scientific communication in spite of the recent success of Open Access Movement. Four options for English-language journals to overcome the language barrier are suggested: 1) abstracts in alternative languages provided by authors, 2) Wiki open translation, 3) international board of translator-editors, and 4) alternative language version of the journal. The Emerging Themes in Epidemiology announces that with immediate effect, it will accept translations of abstracts or full texts by authors as Additional files. Editorial note: In an effort towards overcoming the language barrier in scientific publication, ETE will accept translations of abstracts or the full text of published articles. Each translation should be submitted separately as an Additional File in PDF format. ETE will only peer review English-language versions. Therefore, translations will not be scrutinized in the review-process and the responsibility for accurate translation rests with the authors. PMID:18173854

Overcoming ocular drug delivery barriers through the use of physical forces.

PubMed

Huang, Di; Chen, Ying-Shan; Rupenthal, Ilva D

2018-02-15

Overcoming the physiological barriers in the eye remains a key obstacle in the field of ocular drug delivery. While ocular barriers naturally have a protective function, they also limit drug entry into the eye. Various pharmaceutical strategies, such as novel formulations and physical force-based techniques, have been investigated to weaken these barriers and transport therapeutic agents effectively to both the anterior and the posterior segments of the eye. This review summarizes and discusses the recent research progress in the field of ocular drug delivery with a focus on the application of physical methods, including electrical fields, sonophoresis, and microneedles, which can enhance penetration efficiency by transiently disrupting the ocular barriers in a minimally or non-invasive manner. Copyright © 2017 Elsevier B.V. All rights reserved.

How do Dutch primary care providers overcome barriers to advance care planning with older people? A qualitative study.

PubMed

Glaudemans, Jolien J; de Jong, Anja E; Onwuteaka Philipsen, Bregje D; Wind, Jan; Willems, Dick L

2018-06-11

Few older people benefit from advance care planning (ACP), due to several barriers related to primary care professionals, such as insufficient knowledge, negative beliefs and a lack of time. Information on overcoming these barriers is limited. We assumed primary care professionals experienced in ACP with older patients are likely to have learned how to overcome these barriers. To investigate how Dutch primary care professionals experienced in ACP with older patients overcome these barriers. A qualitative study, based on semi-structured interviews, among a purposive sample of 14 Dutch primary care professionals experienced in ACP with older people. Transcripts were thematically analysed. We interviewed eight general practitioners (GPs), three nurses and three elderly care physicians, experienced in ACP with older people. Respondents overcame their own insufficient knowledge and skills, as well as their negative attitudes and beliefs by gaining experience through practicing ACP in their daily practices, exchanging and reflecting on those experiences with peers, pursuing continuing education, teaching and participating in research. To overcome patients' and families' lack of initiative and openness to ACP, respondents prepared them for further steps in ACP. To overcome a lack of time, respondents used tools and information communication technology, delegated parts of ACP to other primary care professionals, acquired financing and systematized documentation of ACP. Primary care professionals can overcome barriers to ACP with older patients by practicing, reflecting on experiences and pursuing continuing education, by preparing patients and involving family and by investing in support to approach ACP more efficiently.

Overcoming Pedagogical, Social/Cultural, and Attitudinal Barriers to Technology Integration in K-5 Schools

ERIC Educational Resources Information Center

Durff, Lisa

2017-01-01

Technology engages and increases academic achievement for K-5 students, but teachers face attitudinal, social/cultural, and pedagogical barriers when they integrate technology for student learning. Although some teachers overcome these barriers, it remains unclear how they do so. The purpose of this qualitative multiple case study was to analyze…

Overcoming barriers to ITS : lessons from other technologies : final task E report

DOT National Transportation Integrated Search

1995-12-01

The Task E report involves an analysis of franchises and license agreements for the provision of public services, which is the fourth in a series in the study. Overcoming Barriers to ITS - Lessons from Other Technologies. This report follows alternat...

"Closing the Loop": Overcoming barriers to locally sourcing food in Fort Collins, Colorado

NASA Astrophysics Data System (ADS)

DeMets, C. M.

2012-12-01

Environmental sustainability has become a focal point for many communities in recent years, and restaurants are seeking creative ways to become more sustainable. As many chefs realize, sourcing food locally is an important step towards sustainability and towards building a healthy, resilient community. Review of literature on sustainability in restaurants and the local food movement revealed that chefs face many barriers to sourcing their food locally, but that there are also many solutions for overcoming these barriers that chefs are in the early stages of exploring. Therefore, the purpose of this research is to identify barriers to local sourcing and investigate how some restaurants are working to overcome those barriers in the city of Fort Collins, Colorado. To do this, interviews were conducted with four subjects who guide purchasing decisions for restaurants in Fort Collins. Two of these restaurants have created successful solutions and are able to source most of their food locally. The other two are interested in and working towards sourcing locally but have not yet been able to overcome barriers, and therefore only source a few local items. Findings show that there are four barriers and nine solutions commonly identified by each of the subjects. The research found differences between those who source most of their food locally and those who have not made as much progress in local sourcing. Based on these results, two solution flowcharts were created, one for primary barriers and one for secondary barriers, for restaurants to assess where they are in the local food chain and how they can more successfully source food locally. As there are few explicit connections between this research question and climate change, it is important to consider the implicit connections that motivate and justify this research. The question of whether or not greenhouse gas emissions are lower for locally sourced food is a topic of much debate, and while there are major developments

Using Appropriate Digital Tools to Overcome Barriers to Collaborative Learning in Classrooms

ERIC Educational Resources Information Center

Wardlow, Liane; Harm, Eian

2015-01-01

Collaborative learning provides students with vital opportunities to create and build knowledge. Existing technologies can facilitate collaborative learning. However, barriers exist to enacting collaborative practices related to the coverage of material for assessments and classroom management concerns, among others. Teachers can overcome these…

Overcoming Terminology Barrier Using Web Resources for Cross-Language Medical Information Retrieval

PubMed Central

Lu, Wen-Hsiang; Lin, Ray Shih-Jui; Chan, Yi-Che; Chen, Kuan-Hsi

2006-01-01

A number of authoritative medical websites, such as PubMed and MedlinePlus, provide consumers with the most up-to-date health information. However, non-English speakers often encounter not only language barriers (from other languages to English) but also terminology barriers (from laypersons’ terms to professional medical terms) when retrieving information from these websites. Our previous work addresses language barriers by developing a multilingual medical thesaurus, Chinese-English MeSH, while this study presents an approach to overcome terminology barriers based on Web resources. Two techniques were utilized in our approach: monolingual concept mapping using approximate string matching and crosslingual concept mapping using Web resources. The evaluation shows that our approach can significantly improve the performance on MeSH concept mapping and cross-language medical information retrieval. PMID:17238395

Overcoming Barriers to Integrating Behavioral Health and Primary Care Services

PubMed Central

Grazier, Kyle L.; Smiley, Mary L.; Bondalapati, Kirsten S.

2016-01-01

Objective: Despite barriers, organizations with varying characteristics have achieved full integration of primary care services with providers and services that identify, treat, and manage those with mental health and substance use disorders. What are the key factors and common themes in stories of this success? Methods: A systematic literature review and snowball sampling technique was used to identify organizations. Site visits and key informant interviews were conducted with 6 organizations that had over time integrated behavioral health and primary care services. Case studies of each organization were independently coded to identify traits common to multiple organizations. Results: Common characteristics include prioritized vulnerable populations, extensive community collaboration, team approaches that included the patient and family, diversified funding streams, and data-driven approaches and practices. Conclusions: While significant barriers to integrating behavioral health and primary care services exist, case studies of organizations that have successfully overcome these barriers share certain common factors. PMID:27380923

Sustainable steric stabilization of colloidal titania nanoparticles

NASA Astrophysics Data System (ADS)

Elbasuney, Sherif

2017-07-01

A route to produce a stable colloidal suspension is essential if mono-dispersed particles are to be successfully synthesized, isolated, and used in subsequent nanocomposite manufacture. Dispersing nanoparticles in fluids was found to be an important approach for avoiding poor dispersion characteristics. However, there is still a great tendency for colloidal nanoparticles to flocculate over time. Steric stabilization can prevent coagulation by introducing a thick adsorbed organic layer which constitutes a significant steric barrier that can prevent the particle surfaces from coming into direct contact. One of the main features of hydrothermal synthesis technique is that it offers novel approaches for sustainable nanoparticle surface modification. This manuscript reports on the sustainable steric stabilization of titanium dioxide nanoparticles. Nanoparticle surface modification was performed via two main approaches including post-synthesis and in situ surface modification. The tuneable hydrothermal conditions (i.e. temperature, pressure, flow rates, and surfactant addition) were optimized to enable controlled steric stabilization in a continuous fashion. Effective post synthesis surface modification with organic ligand (dodecenyl succinic anhydride (DDSA)) was achieved; the optimum surface coating temperature was reported to be 180-240 °C to ensure DDSA ring opening and binding to titania nanoparticles. Organic-modified titania demonstrated complete change in surface properties from hydrophilic to hydrophobic and exhibited phase transfer from the aqueous phase to the organic phase. Exclusive surface modification in the reactor was found to be an effective approach; it demonstrated surfactant loading level 2.2 times that of post synthesis surface modification. Titania was also stabilized in aqueous media using poly acrylic acid (PAA) as polar polymeric dispersant. PAA-titania nanoparticles demonstrated a durable amorphous polymeric layer of 2 nm thickness. This

Designing Caregiver-Implemented Shared-Reading Interventions to Overcome Implementation Barriers

PubMed Central

Logan, Jessica R.; Damschroder, Laura

2015-01-01

Purpose This study presents an application of the theoretical domains framework (TDF; Michie et al., 2005), an integrative framework drawing on behavior-change theories, to speech-language pathology. Methods A multistep procedure was used to identify barriers affecting caregivers' implementation of shared-reading interventions with their children with language impairment (LI). The authors examined caregiver-level data corresponding to implementation issues from two randomized controlled trials and mapped these to domains in the TDF as well as empirically validated behavior-change techniques. Results Four barriers to implementation were identified as potentially affecting caregivers' implementation: time pressures, reading difficulties, discomfort with reading, and lack of awareness of benefits. These were mapped to 3 TDF domains: intentions, beliefs about capabilities, and skills. In turn, 4 behavior-change techniques were identified as potential vehicles for affecting these domains: reward, feedback, model, and encourage. An ongoing study is described that is determining the effects of these techniques for improving caregivers' implementation of a shared-reading intervention. Conclusions A description of the steps to identifying barriers to implementation, in conjunction with an ongoing experiment that will explicitly determine whether behavior-change techniques affect these barriers, provides a model for how implementation science can be used to identify and overcome implementation barriers in the treatment of communication disorders. PMID:26262941

Designing Caregiver-Implemented Shared-Reading Interventions to Overcome Implementation Barriers.

PubMed

Justice, Laura M; Logan, Jessica R; Damschroder, Laura

2015-12-01

This study presents an application of the theoretical domains framework (TDF; Michie et al., 2005), an integrative framework drawing on behavior-change theories, to speech-language pathology. A multistep procedure was used to identify barriers affecting caregivers' implementation of shared-reading interventions with their children with language impairment (LI). The authors examined caregiver-level data corresponding to implementation issues from two randomized controlled trials and mapped these to domains in the TDF as well as empirically validated behavior-change techniques. Four barriers to implementation were identified as potentially affecting caregivers' implementation: time pressures, reading difficulties, discomfort with reading, and lack of awareness of benefits. These were mapped to 3 TDF domains: intentions, beliefs about capabilities, and skills. In turn, 4 behavior-change techniques were identified as potential vehicles for affecting these domains: reward, feedback, model, and encourage. An ongoing study is described that is determining the effects of these techniques for improving caregivers' implementation of a shared-reading intervention. A description of the steps to identifying barriers to implementation, in conjunction with an ongoing experiment that will explicitly determine whether behavior-change techniques affect these barriers, provides a model for how implementation science can be used to identify and overcome implementation barriers in the treatment of communication disorders.

Overcoming a nucleosomal barrier to replication

PubMed Central

Chang, Han-Wen; Pandey, Manjula; Kulaeva, Olga I.; Patel, Smita S.; Studitsky, Vasily M.

2016-01-01

Efficient overcoming and accurate maintenance of chromatin structure and associated histone marks during DNA replication are essential for normal functioning of the daughter cells. However, the molecular mechanisms of replication through chromatin are unknown. We have studied traversal of uniquely positioned mononucleosomes by T7 replisome in vitro. Nucleosomes present a strong, sequence-dependent barrier for replication, with particularly strong pausing of DNA polymerase at the +(31–40) and +(41–65) regions of the nucleosomal DNA. The exonuclease activity of T7 DNA polymerase increases the overall rate of progression of the replisome through a nucleosome, likely by resolving nonproductive complexes. The presence of nucleosome-free DNA upstream of the replication fork facilitates the progression of DNA polymerase through the nucleosome. After replication, at least 50% of the nucleosomes assume an alternative conformation, maintaining their original positions on the DNA. Our data suggest a previously unpublished mechanism for nucleosome maintenance during replication, likely involving transient formation of an intranucleosomal DNA loop. PMID:27847876

Peer support for CKD patients and carers: overcoming barriers and facilitating access.

PubMed

Taylor, Francesca; Gutteridge, Robin; Willis, Carol

2016-06-01

Peer support is valued by its users. Nevertheless, there is initial low take-up of formal peer support programmes among patients with chronic kidney disease (CKD), with fewer patients participating than expressing an interest. There is little evidence on reasons for low participation levels. Few studies have examined the perspectives of carers. To explore with CKD patients and carers their needs, wants and expectations from formal peer support and examine how barriers to participation may be overcome. Qualitative interviews with a sample of 26 CKD stage five patients and carers. Principles of Grounded Theory were applied to data coding and analysis. Six NHS Hospital Trusts. Whilst informal peer support might occur naturally and is welcomed, a range of emotional and practical barriers inhibit take-up of more formalized support. Receptivity varies across time and the disease trajectory and is associated with emotional readiness; patients and carers needing to overcome complex psychological hurdles such as acknowledging support needs. Practical barriers include limited understanding of peer support. An attractive peer relationship is felt to involve reciprocity based on sharing experiences and both giving and receiving support. Establishing rapport is linked with development of reciprocity. There is potential to facilitate active uptake of formal peer support by addressing the identified barriers. Our study suggests several facilitation methods, brought together in a conceptual model, including clinician promotion of peer support as an intervention suitable for anyone with CKD and their carers, and opportunity for choice of peer supporter. © 2015 The Authors Health Expectations Published by John Wiley & Sons Ltd.

How to Overcome Barriers and Establish a Successful Home HD Program

PubMed Central

Chan, Christopher; Blagg, Christopher; Lockridge, Robert; Golper, Thomas; Finkelstein, Fred; Shaffer, Rachel; Mehrotra, Rajnish

2012-01-01

Summary Home hemodialysis (HD) is an underused dialysis modality in the United States, even though it provides an efficient and probably cost-effective way to provide more frequent or longer dialysis. With the advent of newer home HD systems that are easier for patients to learn, use, and maintain, patient and provider interest in home HD is increasing. Although barriers for providers are similar to those for peritoneal dialysis, home HD requires more extensive patient training, nursing education, and infrastructure support in order to maintain a successful program. In addition, because many physicians and patients do not have experience with home HD, reluctance to start home HD programs is widespread. This in-depth review describes barriers to home HD, focusing on patients, individual physicians and practices, and dialysis facilities, and offers suggestions for how to overcome these barriers and establish a successful home HD program. PMID:23037981

Cancer cells remodel themselves and vasculature to overcome the endothelial barrier.

PubMed

Shenoy, Anitha K; Lu, Jianrong

2016-10-01

Metastasis refers to the spread of cancer cells from a primary tumor to distant organs mostly via the bloodstream. During the metastatic process, cancer cells invade blood vessels to enter circulation, and later exit the vasculature at a distant site. Endothelial cells that line blood vessels normally serve as a barrier to the movement of cells into or out of the blood. It is thus critical to understand how metastatic cancer cells overcome the endothelial barrier. Epithelial cancer cells acquire increased motility and invasiveness through epithelial-to-mesenchymal transition (EMT), which enables them to move toward vasculature. Cancer cells also express a variety of adhesion molecules that allow them to attach to vascular endothelium. Finally, cancer cells secrete or induce growth factors and cytokines to actively prompt vascular hyperpermeability that compromises endothelial barrier function and facilitates transmigration of cancer cells through the vascular wall. Elucidation of the mechanisms underlying metastatic dissemination may help develop new anti-metastasis therapeutics. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Barriers to women engaging in collective action to overcome sexism.

PubMed

Radke, Helena R M; Hornsey, Matthew J; Barlow, Fiona Kate

2016-12-01

Over centuries women have fought hard to obtain increasing gender equality, but despite these successes absolute equality remains an elusive goal. Theoretically, women's numerical strength makes them well-placed to take effective collective action, and millions of women engage in feminist collective action every day. In this article, however, we argue that women also face barriers to engaging in feminist collective action; barriers that are associated with the social construction and experience of what it means to be a woman. Our review synthesizes sexism research under a contemporary collective action framework to clarify our current understanding of the literature and to offer novel theoretical explanations for why women might be discouraged from engaging in feminist collective action. Using the antecedents of collective action identified by van Zomeren, Postmes, and Spears' (2008) meta-analysis, we critically review the sexism literature to argue that women face challenges when it comes to (a) identifying with other women and feminists, (b) perceiving sexism and expressing group-based anger, and (c) recognizing the efficacy of collective action. We then outline a research agenda with a view to investigating ways of overcoming these barriers. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Overcoming Barriers: Adolescents’ Experiences Using a Mobile Phone Dietary Assessment App

PubMed Central

Svensson, Åsa; Magnusson, Maria

2016-01-01

Background The use of new technology has the potential to increase participation rates in dietary studies and improve the validity of collected dietary data. However, to evaluate the usability of developed dietary methods, qualitative studies of participants’ experiences and perceptions are needed. Objective To explore adolescents’ experiences using a newly developed mobile phone dietary assessment app, with a focus on factors that could affect their recording of dietary intake. Methods Focus group interviews were conducted with 75 participants who had used a newly developed mobile phone dietary assessment app in a quantitative evaluation study. The interviews were analyzed using qualitative content analysis and the theoretical framework of Self Determination Theory was applied. Results The adolescents’ use of the mobile phone dietary assessment app was characterized by their struggle to overcome several perceived barriers. Facilitators that helped adolescents complete the method were also identified. Motivation was found to be an important facilitator, and intrinsically motivated participants completed the method because they found it fun to use. The autonomous extrinsically motivated participants completed the method for the greater good, in order to contribute to the study. The controlled extrinsically motivated participants completed the method to get a reward or avoid punishment. Amotivated participants did not complete the method. More motivated participants were assumed to be more able to overcome barriers and needed less facilitators. Conclusions Future studies that examine the recording of food intake should include systematic efforts that aim to minimize identified barriers and promote identified facilitators. Further research should specifically aim at studying methods for (and effects of) increasing intrinsic motivation by supporting autonomy, competence, and relatedness among adolescents asked to participate in dietary studies. PMID:27473462

Exploring How Lay Rescuers Overcome Barriers to Provide Cardiopulmonary Resuscitation: A Qualitative Study.

PubMed

Mathiesen, Wenche Torunn; Bjørshol, Conrad Arnfinn; Høyland, Sindre; Braut, Geir Sverre; Søreide, Eldar

2017-02-01

Survival rates after out-of-hospital cardiac arrest (OHCA) vary considerably among regions. The chance of survival is increased significantly by lay rescuer cardiopulmonary resuscitation (CPR) before Emergency Medical Services (EMS) arrival. It is well known that for bystanders, reasons for not providing CPR when witnessing an OHCA incident may be fear and the feeling of being exposed to risk. The aim of this study was to gain a better understanding of why barriers to providing CPR are overcome. Using a semi-structured interview guide, 10 lay rescuers were interviewed after participating in eight OHCA incidents. Qualitative content analysis was used. The lay rescuers were questioned about their CPR-knowledge, expectations, and reactions to the EMS and from others involved in the OHCA incident. They also were questioned about attitudes towards providing CPR in an OHCA incident in different contexts. The lay rescuers reported that they were prepared to provide CPR to anybody, anywhere. Comprehending the severity in the OHCA incident, both trained and untrained lay rescuers provided CPR. They considered CPR provision to be the expected behavior of any community citizen and the EMS to act professionally and urgently. However, when asked to imagine an OHCA in an unclear setting, they revealed hesitation about providing CPR because of risk to their own safety. Mutual trust between community citizens and towards social institutions may be reasons for overcoming barriers in providing CPR by lay rescuers. A normative obligation to act, regardless of CPR training and, importantly, without facing any adverse legal reactions, also seems to be an important factor behind CPR provision. Mathiesen WT , Bjørshol CA , Høyland S , Braut GS , Søreide E . Exploring how lay rescuers overcome barriers to provide cardiopulmonary resuscitation: a qualitative study. Prehosp Disaster Med. 2017;32(1):27-32.

Mental health care for irregular migrants in Europe: Barriers and how they are overcome

PubMed Central

2012-01-01

Background Irregular migrants (IMs) are exposed to a wide range of risk factors for developing mental health problems. However, little is known about whether and how they receive mental health care across European countries. The aims of this study were (1) to identify barriers to mental health care for IMs, and (2) to explore ways by which these barriers are overcome in practice. Methods Data from semi-structured interviews with 25 experts in the field of mental health care for IMs in the capital cities of 14 European countries were analysed using thematic analysis. Results Experts reported a range of barriers to mental health care for IMs. These include the absence of legal entitlements to health care in some countries or a lack of awareness of such entitlements, administrative obstacles, a shortage of culturally sensitive care, the complexity of the social needs of IMs, and their fear of being reported and deported. These barriers can be partly overcome by networks of committed professionals and supportive services. NGOs have become important initial points of contact for IMs, providing mental health care themselves or referring IMs to other suitable services. However, these services are often confronted with the ethical dilemma of either acting according to the legislation and institutional rules or providing care for humanitarian reasons, which involves the risk of acting illegally and providing care without authorisation. Conclusions Even in countries where access to health care is legally possible for IMs, various other barriers remain. Some of these are common to all migrants, whilst others are specific for IMs. Attempts at improving mental health care for IMs should consider barriers beyond legal entitlement, including communicating information about entitlement to mental health care professionals and patients, providing culturally sensitive care and ensuring sufficient resources. PMID:22607386

Overcoming Codes and Standards Barriers to Innovations in Building Energy Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Pamala C.; Gilbride, Theresa L.

2015-02-15

In this journal article, the authors discuss approaches to overcoming building code barriers to energy-efficiency innovations in home construction. Building codes have been a highly motivational force for increasing the energy efficiency of new homes in the United States in recent years. But as quickly as the codes seem to be changing, new products are coming to the market at an even more rapid pace, sometimes offering approaches and construction techniques unthought of when the current code was first proposed, which might have been several years before its adoption by various jurisdictions. Due to this delay, the codes themselves canmore » become barriers to innovations that might otherwise be helping to further increase the efficiency, comfort, health or durability of new homes. . The U.S. Department of Energy’s Building America, a program dedicated to improving the energy efficiency of America’s housing stock through research and education, is working with the U.S. housing industry through its research teams to help builders identify and remove code barriers to innovation in the home construction industry. The article addresses several approaches that builders use to achieve approval for innovative building techniques when code barriers appear to exist.« less

Overcoming the Confucian psychological barrier in government cyberspace.

PubMed

Lee, Ook; Gong, Sung Jin

2004-02-01

The Confucian tradition still dictates the behavior of many people in East Asian countries such as South Korea. Even in e-mail communication, people try their best to show signs of respect which is required by the Confucian tradition. This psychological barrier can be detrimental to the development of democracy as people are educated not to challenge opinions of elders or bosses. After a long military dictatorship, South Korea has emerged as a newly democratized nation where the Confucian tradition is less emphasized. However, this tradition dies hard, and citizens are still afraid of offending government officials who have the power to affect lives of citizens. In light of creating a more democratic society, the e-government project has been implemented, and one of the features of cyber-government is to give citizens a place in cyberspace to express their concerns. Even though citizens have to use their real names, it is found that those who wrote messages in the bulletin board of the city of Seoul government's web pages tend not to use terms that are often used in e-mails for the purpose of expressing respect. A survey was conducted, and results show that people were able to overcome the Confucian psychological barrier in government cyberspace. Self-efficacy is proposed to explain this phenomenon.

Overcoming barriers to recruiting ethnic minorities to mental health research: a typology of recruitment strategies.

PubMed

Waheed, Waquas; Hughes-Morley, Adwoa; Woodham, Adrine; Allen, Gill; Bower, Peter

2015-05-02

The ethnic minority population in developed countries is increasing over time. These groups are at higher risk of mental illness and demonstrate lower participation in research. Published evidence suggests that multiple factors like stigma, lack of trust, differences in explanatory models, logistical issues and lack of culturally aware researchers act as barriers to ethnic minority recruitment into mental health research. To reduce inequalities in participation, there is a need to devise innovative and culturally sensitive recruitment strategies. It is important that researchers share their experience of employing these strategies so that ethnic minority participation can be facilitated. We previously published a systematic review of barriers to recruiting ethnic minority participants into mental health research. The nine papers included in our prior review formed the basis for developing a typology of barriers to recruiting ethnic minorities into mental health research. This typology identified 33 barriers, described under five themes. We further extracted data on the strategies used to overcome these recruitment barriers, as described in the included studies. The strategies employed by the authors could be matched to all but two barriers (psychopathology/substance misuse and limited resource availability). There was evidence that multiple strategies were employed, and that these depended upon the population, clinical set-up and resources available. This typology of strategies to overcome barriers to recruiting ethnic minorities provides guidance on achieving higher rates of recruitment. It is important that researchers plan to deploy these strategies well in advance of initiating recruitment. Whilst adopting these strategies, the authors have not been able to quantify the positive impact of these strategies on recruitment. The typology should encourage researchers to employ these strategies in future research, refine them further and quantitatively evaluate their

How Greek nurses perceive and overcome the barriers in implementing treatment for pressure ulcers: 'against the odds'.

PubMed

Kaba, E; Kelesi, M; Stavropoulou, A; Moustakas, D; Fasoi, G

2017-09-01

Although the occurrence of pressure ulcers (PUs) is now considered as an indicator of poor quality nursing care, questions and concerns remain regarding situations where PUs were unavoidable, irrespective of the care provided. The aim of this study was to explore Greek nurses' perceptions about the barriers involved and to identify the factors that influence care planning in PU treatment. A grounded theory approach was used and semi-structured interviews were conducted with nurses who provided pressure care to clients in a rehabilitation centre in Greece. Data were analysed using the constant comparative method. We interviewed seven nurses. Findings revealed one main category entitled 'anarchy' in delivery of care consisted of the following three subcategories: interdisciplinary conflicts; total trust in traditional knowledge; and devaluation of other's work/role and a core category 'Against the odds': the perceived value of prevention and treatment can overcome the barriers in treating PUs. This study gives an overview of the views and beliefs of nurses about the problems and barriers involved in PU prevention and treatment. The study reveals that although some barriers to good practice may exist, nurses can hold a positive attitude toward PU prevention and treatment, and their perceived value of prevention and treatment may help nurses to overcome the barriers in managing PUs.

Overcoming early barriers to PCMH practice improvement in family medicine residencies.

PubMed

Fernald, Douglas H; Deaner, Nicole; O'Neill, Caitlin; Jortberg, Bonnie T; degruy, Frank Verloin; Dickinson, W Perry

2011-01-01

Residency programs face inevitable challenges as they redesign their practices for higher quality care and resident training. Identifying and addressing early barriers can help align priorities and thereby augment the capacity to change. Evaluation of the Colorado Family Medicine Residency PCMH Project included iterative qualitative analysis of field notes, interviews, and documents to identify early barriers to change and strategies to overcome them. Nine common but not universal barriers were identified: (1) a practice's history reflected some negative past experiences with quality improvement or routines incompatible with transformative change, (2) leadership gaps were evident in unprepared practice leaders or hierarchical leadership, (3) resistance and skepticism about change were expressed through cynicism aimed at change or ability to change, (4) unproductive team processes were reflected in patterns of canceled meetings, absentee leaders, or lack of accountability, (5) knowledge gaps about the Patient-centered Medical Home (PCMH) were apparent from incomplete dissemination about the project or planned changes, (6) EHR implementation distracted focus or stalled improvement activity, (7) sponsoring organizations' constraints emerged from staffing rules and differing priorities, (8) insufficient staff participation resulted from traditional role expectations and structures, and (9) communication was hampered by ineffective methods and part-time faculty and residents. Early barriers responded to varying degrees to specific interventions by practice coaches. Some barriers that interfere with practices getting started with cultural and structural transformation can be addressed with persistent attention and reflection from on-site coaches and by realigning the talents, leaders, and priorities already in these residency programs.

Challenges confronting female surgical leaders: overcoming the barriers.

PubMed

Kass, Rena B; Souba, Wiley W; Thorndyke, Luanne E

2006-05-15

The number of women reaching top ranks in academic surgery is remarkably low. The purpose of this study was to identify: 1) barriers to becoming a female surgical leader; 2) key attributes that enable advancement and success; and 3) current leadership challenges faced as senior leaders. Semi-structured interviews of ten female surgical leaders queried the following dimensions: attributes for success, lessons learned, mistakes, key career steps, the role of mentoring, gender advantages/disadvantages, and challenges. Perseverance (60%) and drive (50%) were identified as critical success factors, as were good communication skills, a passion for scholarship, a stable home life and a positive outlook. Eighty percent identified discrimination or gender prejudice as a major obstacle in their careers. While 90% percent had mentors, 50% acknowledged that they had not been effectively mentored. Career advice included: develop broad career goals (50%); select a conducive environment (30%); find a mentor (60%); take personal responsibility (40%); organize time and achieve balance (40%); network (30%); create a niche (30%); pursue research (30%); publish (50%); speak in public (30%); and enjoy the process (30%). Being in a minority, being highly visible and being collaborative were identified as advantages. Obtaining buy-in and achieving consensus was the greatest leadership challenge reported. Female academic surgeons face challenges to career advancement. While these barriers are real, they can be overcome by resolve, commitment, and developing strong communication skills. These elements should be taken into consideration in designing career development programs for junior female surgical faculty.

Overcoming Barriers to Public Engagement through a Multi-Institution Consortium

NASA Astrophysics Data System (ADS)

Lambert, K. F.; Weiss, M.; Garlick, S.

2016-12-01

A growing body of evidence suggests that public engagement with science (PES) can enhance the relevance and impact of science on society. At the same time, advances in our understanding of public engagement suggest that greater skills, resources, and time horizons are often required to create effective programs. Consequently, despite a proliferation of training programs, many scientists still face the challenge of balancing the demands of public engagement with the requirements of their disciplinary research. Novel institutions are emerging that bring together interdisciplinary networks of principle investigators with PES practitioners to overcome barriers to effective and sustained public engagement in the environmental sciences. We will use the Science Policy Exchange (SPE), a consortium housed at the Harvard Forest, Harvard University, to illustrate how PIs and PES practitioners can collaborate to design public engagement processes, conduct policy-relevant scientific syntheses, and implement science communication strategies. Results from two SPE case studies demonstrate how multi-institutional consortia can help scientists overcome barriers such as lack of knowledge of evidence-based PES approaches, limits on time and funding to implement PES projects, and the need to integrate PES activities with research. The case studies also show how SPE strives to achieve credibility, saliency, and legitimacy in different public policy contexts: (1) engagement between scientists and local stakeholders to develop scenarios of landscape change; and (2) engagement between scientists and policy makers to understand the relationship between power plant emission standards, and air quality, human health and ecosystem function. The presentation will conclude with examples of how SPE programs have led to institutional change (staffing and budget), cultural change (attitudes and expectations of senior leaders), and research change (development of research questions, funding proposals

Overcoming Barriers in Kidney Health-Forging a Platform for Innovation.

PubMed

Linde, Peter G; Archdeacon, Patrick; Breyer, Matthew D; Ibrahim, Tod; Inrig, Jula K; Kewalramani, Reshma; Lee, Celeste Castillo; Neuland, Carolyn Y; Roy-Chaudhury, Prabir; Sloand, James A; Meyer, Rachel; Smith, Kimberly A; Snook, Jennifer; West, Melissa; Falk, Ronald J

2016-07-01

Innovation in kidney diseases is not commensurate with the effect of these diseases on human health and mortality or innovation in other key therapeutic areas. A primary cause of the dearth in innovation is that kidney diseases disproportionately affect a demographic that is largely disenfranchised, lacking sufficient advocacy, public attention, and funding. A secondary and likely consequent cause is that the existing infrastructure supporting nephrology research pales in comparison with those for other internal medicine specialties, especially cardiology and oncology. Citing such inequities, however, is not enough. Changing the status quo will require a coordinated effort to identify and redress the existing deficits. Specifically, these deficits relate to the need to further develop and improve the following: understanding of the disease mechanisms and pathophysiology, patient engagement and activism, clinical trial infrastructure, and investigational clinical trial designs as well as coordinated efforts among critical stakeholders. This paper identifies potential solutions to these barriers, some of which are already underway through the Kidney Health Initiative. The Kidney Health Initiative is unique and will serve as a current and future platform from which to overcome these barriers to innovation in nephrology. Copyright © 2016 by the American Society of Nephrology.

Overcoming barriers to implementation of evidence-based practice concepts in athletic training education: perceptions of select educators.

PubMed

Manspeaker, Sarah; Van Lunen, Bonnie

2011-01-01

The need to include evidence-based practice (EBP) concepts in entry-level athletic training education is evident as the profession transitions toward using evidence to inform clinical decision making. To evaluate athletic training educators' experience with implementation of EBP concepts in Commission on Accreditation of Athletic Training Education (CAATE)-accredited entry-level athletic training education programs in reference to educational barriers and strategies for overcoming these barriers. Qualitative interviews of emergent design with grounded theory. Undergraduate CAATE-accredited athletic training education programs. Eleven educators (3 men, 8 women). The average number of years teaching was 14.73 ± 7.06. Interviews were conducted to evaluate perceived barriers and strategies for overcoming these barriers to implementation of evidence-based concepts in the curriculum. Interviews were explored qualitatively through open and axial coding. Established themes and categories were triangulated and member checked to determine trustworthiness. Educators identified 3 categories of need for EBP instruction: respect for the athletic training profession, use of EBP as part of the decision-making toolbox, and third-party reimbursement. Barriers to incorporating EBP concepts included time, role strain, knowledge, and the gap between clinical and educational practices. Suggested strategies for surmounting barriers included identifying a starting point for inclusion and approaching inclusion from a faculty perspective. Educators must transition toward instruction of EBP, regardless of barriers present in their academic programs, in order to maintain progress with other health professions' clinical practices and educational standards. Because today's students are tomorrow's clinicians, we need to include EBP concepts in entry-level education to promote critical thinking, inspire potential research interest, and further develop the available body of knowledge in our

Overcoming Barriers to Sustained Engagement in Mental Health Care: Perspectives of Rural Veterans and Providers.

PubMed

Fischer, Ellen P; McSweeney, Jean C; Wright, Patricia; Cheney, Ann; Curran, Geoffrey M; Henderson, Kathy; Fortney, John C

2016-09-01

To better understand the attitudes, beliefs, and values that influence use of mental health care among rural veterans. In-depth, semistructured interviews were conducted with 25 rural veterans and 11 rural mental health care providers in 4 states. Experienced qualitative interviewers asked participants about the attitudinal factors they thought most influenced rural veterans' decisions to seek and sustain mental health care. Verbatim transcriptions were analyzed using content analysis and constant comparison. Rural veterans and their mental health care providers reported the same major attitudinal barriers to veterans' mental health treatment-seeking. Pre-eminent among those barriers was the importance rural veterans place on independence and self-reliance. The centrality of self-reliance was attributed variously to rural, military, religious, and/or gender-based belief systems. Stoicism, the stigma associated with mental illness and health care, and a lack of trust in the VA as a caring organization were also frequently mentioned. Perceived need for care and the support of other veterans were critical to overcoming attitudinal barriers to initial treatment-seeking, whereas critical facilitators of ongoing service use included "warm handoffs" from medical to mental health care providers, perceived respect and caring from providers, as well as provider accessibility and continuity. Attitudes and values, like self-reliance, commonly associated with rural culture may play an important role in underutilization of needed mental health services. System support for peer and provider behaviors that generate trust and demonstrate caring may help overcome attitudinal barriers to treatment-seeking and sustained engagement in mental health care among rural veterans. © 2016 National Rural Health Association.

Danish research-active clinical nurses overcome barriers in research utilization.

PubMed

Adamsen, Lis; Larsen, Kristian; Bjerregaard, Lene; Madsen, Jan K

2003-03-01

The aim of this study was to examine whether there was a difference between clinical nurses who were research-active, and clinical nurses who were nonresearch-active in utilization of research. A further aim was to identify the most significant barriers faced by a group of Danish clinical nurses in their use of research. Discrepancy between the improved quality of research results and the lack of implementing them was the starting point for a series of studies which showed the types of barriers clinical nurses found especially cumbersome when applying the research results of other researchers. This study investigates whether the clinical nurses' own engagement in research had any impact on their perception of research utilization. The study had an exploratory and descriptive design. Seventy-nine Danish clinical nurses participated and semi-structured interviewing was used as the research method. There was a statistically significant difference between the research-active and nonresearch-active nurses on various variables. The study showed that, to a larger extent, research-active nurses used evidence-based knowledge and were generally more internationally orientated. Furthermore, two important barriers for research utilization were identified by all 79 clinical nurses included in the study, i.e. 90% of the nurses explained that the quantity of research results was overwhelming, and 75% of them found that they were unable to evaluate the quality of the research. Clinical nurses, who were research-active themselves, experienced more success in overcoming some of the barriers, which existed in applying research to practice. The research potential found amongst clinical nurses in Denmark needed to be further supported through training and guidance in research methodology, establishing introductory stipends and part-time research positions. By doing so, some of the barriers affecting research utilization and the so-called theory-practice gap might be reduced. Further

Smart nanoparticles improve therapy for drug-resistant tumors by overcoming pathophysiological barriers

PubMed Central

Liu, Jian-ping; Wang, Ting-ting; Wang, Dang-ge; Dong, An-jie; Li, Ya-ping; Yu, Hai-jun

2017-01-01

The therapeutic outcome of chemotherapy is severely limited by intrinsic or acquired drug resistance, the most common causes of chemotherapy failure. In the past few decades, advancements in nanotechnology have provided alternative strategies for combating tumor drug resistance. Drug-loaded nanoparticles (NPs) have several advantages over the free drug forms, including reduced cytotoxicity, prolonged circulation in the blood and increased accumulation in tumors. Currently, however, nanoparticulate drugs have only marginally improved the overall survival rate in clinical trials because of the various pathophysiological barriers that exist in the tumor microenvironment, such as intratumoral distribution, penetration and intracellular trafficking, etc. Smart NPs with stimulus-adaptable physico-chemical properties have been extensively developed to improve the therapeutic efficacy of nanomedicine. In this review, we summarize the recent advances of employing smart NPs to treat the drug-resistant tumors by overcoming the pathophysiological barriers in the tumor microenvironment. PMID:27569390

Smart nanoparticles improve therapy for drug-resistant tumors by overcoming pathophysiological barriers.

PubMed

Liu, Jian-Ping; Wang, Ting-Ting; Wang, Dang-Ge; Dong, An-Jie; Li, Ya-Ping; Yu, Hai-Jun

2017-01-01

The therapeutic outcome of chemotherapy is severely limited by intrinsic or acquired drug resistance, the most common causes of chemotherapy failure. In the past few decades, advancements in nanotechnology have provided alternative strategies for combating tumor drug resistance. Drug-loaded nanoparticles (NPs) have several advantages over the free drug forms, including reduced cytotoxicity, prolonged circulation in the blood and increased accumulation in tumors. Currently, however, nanoparticulate drugs have only marginally improved the overall survival rate in clinical trials because of the various pathophysiological barriers that exist in the tumor microenvironment, such as intratumoral distribution, penetration and intracellular trafficking, etc. Smart NPs with stimulus-adaptable physico-chemical properties have been extensively developed to improve the therapeutic efficacy of nanomedicine. In this review, we summarize the recent advances of employing smart NPs to treat the drug-resistant tumors by overcoming the pathophysiological barriers in the tumor microenvironment.

Autism and Overcoming Job Barriers: Comparing Job-Related Barriers and Possible Solutions in and outside of Autism-Specific Employment

PubMed Central

Lorenz, Timo; Frischling, Cora; Cuadros, Raphael; Heinitz, Kathrin

2016-01-01

The aim of this study was to discover how individuals with autism succeed in entering the job market. We therefore sought to identify expected and occurred barriers, keeping them from taking up and staying in employment as well as to identify the solutions used to overcome these barriers. Sixty-six employed individuals with autism–17 of them with autism-specific employment–participated in an online survey. Results showed a variety of possible barriers. Individuals in autism-specific employment named formality problems–problems with organizational and practical process-related aspects of the job entry–most frequently while individuals in non-autism-specific employment mentioned social problems–obstacles concerning communication and human interaction–most. In terms of solutions, both groups used their own resources as much as external help, but differed in their specific strategies. In addition, correlations of an autism-specific employment with general and occupational self-efficacy as well as life and job satisfaction were examined. Possible implications of the results are discussed with regard to problem solving behavior and the use of strengths. PMID:26766183

Nanocarrier mediated retinal drug delivery: overcoming ocular barriers to treat posterior eye diseases.

PubMed

Bisht, Rohit; Mandal, Abhirup; Jaiswal, Jagdish K; Rupenthal, Ilva D

2018-03-01

Effective drug delivery to the retina still remains a challenge due to ocular elimination mechanisms and complex barriers that selectively limit the entry of drugs into the eye. To overcome these barriers, frequent intravitreal injections are currently used to achieve high drug concentrations in vitreous and retina. However, these repetitive injections may result in several side effects. Recent advancements in the field of nanoparticle-based drug delivery could overcome some of these unmet needs and various preclinical studies conducted to date have demonstrated promising results of nanotherapies in the treatment of retinal diseases. Compared to the majority of commercially available ocular implants, the biodegradable nature of most nanoparticles (NPs) avoids the need for surgical implantation and removal after the release of the payload. In addition, the sustained drug release from NPs over an extended period of time reduces the need for frequent intravitreal injections and the risk of associated side effects. The nanometer size and highly modifiable surface properties make NPs excellent candidates for targeted ocular drug delivery. Studies have shown that nanocarriers enhance the intravitreal half-life and thus bioavailability of a number of drugs including proteins and peptides. In addition, they have shown promising results in delivering genetic material to the retinal tissues by protecting it from possible intravitreal degradation. This review covers the various challenges associated with drug delivery to the posterior segment of the eye, particularly the retina, and highlights the application of nanocarriers to overcome these challenges in context with recent advances in preclinical studies. WIREs Nanomed Nanobiotechnol 2018, 10:e1473. doi: 10.1002/wnan.1473 This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Implantable Materials and Surgical Technologies > Nanomaterials and Implants. © 2017 Wiley Periodicals

Translating Research to Practice: Overcoming Barriers to Implementing Effective Off-Campus Party Intervention. Issues in Prevention

ERIC Educational Resources Information Center

Higher Education Center for Alcohol, Drug Abuse, and Violence Prevention, 2012

2012-01-01

This issue of "Issues in Prevention" focuses on overcoming barriers in implementing effective off-campus party intervention. This issue contains the following articles: (1) Confronting the Problems Associated With Off-Campus Parties With Evidence-Based Strategies (John D. Clapp); (2) Overview of Research on Effective Off-Campus Party…

Overcoming Barriers to Implementation of Evidence-Based Practice Concepts in Athletic Training Education: Perceptions of Select Educators

PubMed Central

Manspeaker, Sarah; Van Lunen, Bonnie

2011-01-01

Context: The need to include evidence-based practice (EBP) concepts in entry-level athletic training education is evident as the profession transitions toward using evidence to inform clinical decision making. Objective: To evaluate athletic training educators' experience with implementation of EBP concepts in Commission on Accreditation of Athletic Training Education (CAATE)-accredited entry-level athletic training education programs in reference to educational barriers and strategies for overcoming these barriers. Design: Qualitative interviews of emergent design with grounded theory. Setting: Undergraduate CAATE-accredited athletic training education programs. Patients or Other Participants: Eleven educators (3 men, 8 women). The average number of years teaching was 14.73 ± 7.06. Data Collection and Analysis: Interviews were conducted to evaluate perceived barriers and strategies for overcoming these barriers to implementation of evidence-based concepts in the curriculum. Interviews were explored qualitatively through open and axial coding. Established themes and categories were triangulated and member checked to determine trustworthiness. Results: Educators identified 3 categories of need for EBP instruction: respect for the athletic training profession, use of EBP as part of the decision-making toolbox, and third-party reimbursement. Barriers to incorporating EBP concepts included time, role strain, knowledge, and the gap between clinical and educational practices. Suggested strategies for surmounting barriers included identifying a starting point for inclusion and approaching inclusion from a faculty perspective. Conclusions: Educators must transition toward instruction of EBP, regardless of barriers present in their academic programs, in order to maintain progress with other health professions' clinical practices and educational standards. Because today's students are tomorrow's clinicians, we need to include EBP concepts in entry-level education to promote

School-based service delivery for homeless students: relevant laws and overcoming access barriers.

PubMed

Sulkowski, Michael L; Joyce-Beaulieu, Diana K

2014-11-01

Schools in the United States are facing a record number of homeless students. These students are highly at-risk for experiencing negative life outcomes, and they face considerable academic and social-emotional functional impairments. To help address the complex needs of homeless students, this article reviews the intersection of laws and practices that impact homeless students, as well as contemporary school-based service delivery efforts to support the academic and social-emotional needs of these students. In addition, this article also reviews several barriers to school-based service delivery for homeless students and ways to overcome these barriers. These barriers include confusion regarding consent and record-sharing procedures, ineffectively utilizing homeless liaisons, and misapplying tenants of Multitiered Systems of Support (MTSS), which is a school-based service-delivery framework that has been adopted by and implemented in many U.S. schools. Ultimately, this article aims to provide members of school communities with practical information that they can use to support the homeless youth they encounter and serve. (c) 2014 APA, all rights reserved.

Steric Pressure among Membrane-Bound Polymers Opposes Lipid Phase Separation.

PubMed

Imam, Zachary I; Kenyon, Laura E; Carrillo, Adelita; Espinoza, Isai; Nagib, Fatema; Stachowiak, Jeanne C

2016-04-19

Lipid rafts are thought to be key organizers of membrane-protein complexes in cells. Many proteins that interact with rafts have bulky polymeric components such as intrinsically disordered protein domains and polysaccharide chains. Therefore, understanding the interaction between membrane domains and membrane-bound polymers provides insights into the roles rafts play in cells. Multiple studies have demonstrated that high concentrations of membrane-bound polymeric domains create significant lateral steric pressure at membrane surfaces. Furthermore, our recent work has shown that lateral steric pressure at membrane surfaces opposes the assembly of membrane domains. Building on these findings, here we report that membrane-bound polymers are potent suppressors of membrane phase separation, which can destabilize lipid domains with substantially greater efficiency than globular domains such as membrane-bound proteins. Specifically, we created giant vesicles with a ternary lipid composition, which separated into coexisting liquid ordered and disordered phases. Lipids with saturated tails and poly(ethylene glycol) (PEG) chains conjugated to their head groups were included at increasing molar concentrations. When these lipids were sparse on the membrane surface they partitioned to the liquid ordered phase. However, as they became more concentrated, the fraction of GUVs that were phase-separated decreased dramatically, ultimately yielding a population of homogeneous membrane vesicles. Experiments and physical modeling using compositions of increasing PEG molecular weight and lipid miscibility phase transition temperature demonstrate that longer polymers are the most efficient suppressors of membrane phase separation when the energetic barrier to lipid mixing is low. In contrast, as the miscibility transition temperature increases, longer polymers are more readily driven out of domains by the increased steric pressure. Therefore, the concentration of shorter polymers required

Consumer direction in long-term care policy: overcoming barriers to promoting older adults' opportunity for self-direction.

PubMed

Ruggiano, Nicole

2012-01-01

There has been a growing trend in long-term care policy to offer individuals with disabilities the option of consumer direction (CD), where responsibility of managing care and support services is transferred from agencies to care recipients, thus supporting clients' self-determination. Although CD has been accepted as an option for non-elderly individuals with disabilities, barriers persist to promoting older adults' autonomy through CD. This article reviews the incorporation of CD in long-term care policy, addresses the current barriers to providing older adults the right to self-direct, and makes recommendations for overcoming these barriers through social work practice, policy, and research.

Overcoming free energy barriers using unconstrained molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Hénin, Jérôme; Chipot, Christophe

2004-08-01

Association of unconstrained molecular dynamics (MD) and the formalisms of thermodynamic integration and average force [Darve and Pohorille, J. Chem. Phys. 115, 9169 (2001)] have been employed to determine potentials of mean force. When implemented in a general MD code, the additional computational effort, compared to other standard, unconstrained simulations, is marginal. The force acting along a chosen reaction coordinate ξ is estimated from the individual forces exerted on the chemical system and accumulated as the simulation progresses. The estimated free energy derivative computed for small intervals of ξ is canceled by an adaptive bias to overcome the barriers of the free energy landscape. Evolution of the system along the reaction coordinate is, thus, limited by its sole self-diffusion properties. The illustrative examples of the reversible unfolding of deca-L-alanine, the association of acetate and guanidinium ions in water, the dimerization of methane in water, and its transfer across the water liquid-vapor interface are examined to probe the efficiency of the method.

Cronobacter sakazakii clinical isolates overcome host barriers and evade the immune response.

PubMed

Almajed, Faisal S; Forsythe, Stephen J

2016-01-01

Cronobacter sakazakii is the most frequently clinically isolated species of the Cronobacter genus. However the virulence factors of C. sakazakii including their ability to overcome host barriers remains poorly studied. In this study, ten clinical isolates of C. sakazakii were assessed for their ability to invade and translocate through human colonic carcinoma epithelial cells (Caco-2) and human brain microvascular endothelial cells (HBMEC). Their ability to avoid phagocytosis in human macrophages U937 and human brain microglial cells was investigated. Additionally, they were tested for serum sensitivity and the presence of the Cronobacter plasminogen activation gene (cpa) gene, which is reported to confer serum resistance. Our data showed that the clinical C. sakazakii strains invaded and translocated through Caco-2 and HBMEC cell lines and some strains showed significantly higher levels of invasion and translocation. Moreover, C. sakazakii was able to persist and even multiply in phagocytic macrophage and microglial cells. All strains, except one, were able to withstand human serum exposure, the single serum sensitive strain was also the only one which did not encode for the cpa gene. These results demonstrate that C. sakazakii clinical isolates are able to overcome host barriers and evade the host immune response indicating their capacity to cause diseases such as necrotizing enterocolitis (NEC) and meningitis. Our data showed for the first time the ability of C. sakazakii clinical isolates to survive and multiply within human microglial cells. Additionally, it was shown that C. sakazakii clinical strains have the capacity to translocate through the Caco-2 and HBMEC cell lines paracellularly. Copyright © 2015 Elsevier Ltd. All rights reserved.

Teams, tribes and patient safety: overcoming barriers to effective teamwork in healthcare.

PubMed

Weller, Jennifer; Boyd, Matt; Cumin, David

2014-03-01

Modern healthcare is delivered by multidisciplinary, distributed healthcare teams who rely on effective teamwork and communication to ensure effective and safe patient care. However, we know that there is an unacceptable rate of unintended patient harm, and much of this is attributed to failures in communication between health professionals. The extensive literature on teams has identified shared mental models, mutual respect and trust and closed-loop communication as the underpinning conditions required for effective teams. However, a number of challenges exist in the healthcare environment. We explore these in a framework of educational, psychological and organisational challenges to the development of effective healthcare teams. Educational interventions can promote a better understanding of the principles of teamwork, help staff understand each other's roles and perspectives, and help develop specific communication strategies, but may not be sufficient on their own. Psychological barriers, such as professional silos and hierarchies, and organisational barriers such as geographically distributed teams, can increase the chance of communication failures with the potential for patient harm. We propose a seven-step plan to overcome the barriers to effective team communication that incorporates education, psychological and organisational strategies. Recent evidence suggests that improvement in teamwork in healthcare can lead to significant gains in patient safety, measured against efficiency of care, complication rate and mortality. Interventions to improve teamwork in healthcare may be the next major advance in patient outcomes.

Helping Our Most Vulnerable Families Overcome Barriers to Work and Achieve Financial Success. KIDS COUNT 2005 Essay

ERIC Educational Resources Information Center

Annie E. Casey Foundation, 2005

2005-01-01

This essay, taken from the 2005 KIDS COUNT Data Book, examines four employment barriers that policymakers and others consider among the most difficult to overcome: substance abuse, domestic violence, a history of incarceration, and depression. These burdens can diminish a person's motivation and ability to find work. Furthermore, they can make it…

Overcoming free energy barriers using unconstrained molecular dynamics simulations.

PubMed

Hénin, Jérôme; Chipot, Christophe

2004-08-15

Association of unconstrained molecular dynamics (MD) and the formalisms of thermodynamic integration and average force [Darve and Pohorille, J. Chem. Phys. 115, 9169 (2001)] have been employed to determine potentials of mean force. When implemented in a general MD code, the additional computational effort, compared to other standard, unconstrained simulations, is marginal. The force acting along a chosen reaction coordinate xi is estimated from the individual forces exerted on the chemical system and accumulated as the simulation progresses. The estimated free energy derivative computed for small intervals of xi is canceled by an adaptive bias to overcome the barriers of the free energy landscape. Evolution of the system along the reaction coordinate is, thus, limited by its sole self-diffusion properties. The illustrative examples of the reversible unfolding of deca-L-alanine, the association of acetate and guanidinium ions in water, the dimerization of methane in water, and its transfer across the water liquid-vapor interface are examined to probe the efficiency of the method. (c) 2004 American Institute of Physics.

College Students Must Overcome Barriers to Use Calorie Labels in Fast-Food Restaurants.

PubMed

Stran, Kimberly A; Knol, Linda L; Turner, Lori W; Severt, Kimberly; McCallum, Debra M; Lawrence, Jeannine C

2016-02-01

To explore predictors of intention of college students to use calorie labels on fast-food menus and differences in calories ordered after viewing calorie information. Quasi-experimental design. Participants selected a meal from a menu without calorie labels, selected a meal from the same menu with calorie labels, and completed a survey that assessed demographics, dietary habits, Theory of Planned Behavior constructs, and potential barriers to use of calorie labeling. A southern university. Undergraduate university students (n = 97). Predictors of intention to use calorie labels and whether calories selected from the nonlabeled menu differed from the labeled menu. Confirmatory factor analysis, exploratory factor analysis, multiple regression, and paired t tests. Participants ordered significantly fewer calories (P = .02) when selecting from the labeled menu vs the menu without labels. Attitudes (P = .006), subjective norms (P < .001), and perceived behavioral control (P = .01) predicted intention to use calorie information but did not predict a difference in the calories ordered. Hunger (P = .03) and cost (P = .04) were barriers to using the calorie information. If students can overcome barriers, calorie labeling could provide information that college students need to select lower-calorie items at fast-food restaurants. Copyright © 2016 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

'We do the impossible': women overcoming barriers to cervical cancer screening in rural Honduras--a positive deviance analysis.

PubMed

Garrett, Jenna J; Barrington, Clare

2013-01-01

Cervical cancer is the leading cause of cancer death for women in Honduras, and sexual behaviour and low screening uptake are two major factors contributing to high rates of morbidity and mortality. A qualitative study was conducted to investigate barriers that prevent rural Honduran women from engaging in screening and ways that women overcome those barriers. This study examined examples of positive deviance, or individuals engaging in the uncommon but beneficial practise of screening. Amor por sí misma (self-love), and social support were identified as two constructs women employed to overcome barriers to screening. Participants defined self-love as the act of displaying care and concern for oneself and one's health and suggested that it compels women to participate in screening. Social support was defined as receiving tangible aid and advice from others that facilitated women's screening participation. Findings suggest that the concept of self-love could be used in future screening promotion efforts and that integrating social support would also be beneficial. Engaging men in sexual and reproductive health programming is suggested in order to ensure male partners offer social support for screening and to challenge the cultural, gender and sexual norms that place women at higher risk for cervical cancer.

From information theory to quantitative description of steric effects.

PubMed

Alipour, Mojtaba; Safari, Zahra

2016-07-21

Immense efforts have been made in the literature to apply the information theory descriptors for investigating the electronic structure theory of various systems. In the present study, the information theoretic quantities, such as Fisher information, Shannon entropy, Onicescu information energy, and Ghosh-Berkowitz-Parr entropy, have been used to present a quantitative description for one of the most widely used concepts in chemistry, namely the steric effects. Taking the experimental steric scales for the different compounds as benchmark sets, there are reasonable linear relationships between the experimental scales of the steric effects and theoretical values of steric energies calculated from information theory functionals. Perusing the results obtained from the information theoretic quantities with the two representations of electron density and shape function, the Shannon entropy has the best performance for the purpose. On the one hand, the usefulness of considering the contributions of functional groups steric energies and geometries, and on the other hand, dissecting the effects of both global and local information measures simultaneously have also been explored. Furthermore, the utility of the information functionals for the description of steric effects in several chemical transformations, such as electrophilic and nucleophilic reactions and host-guest chemistry, has been analyzed. The functionals of information theory correlate remarkably with the stability of systems and experimental scales. Overall, these findings show that the information theoretic quantities can be introduced as quantitative measures of steric effects and provide further evidences of the quality of information theory toward helping theoreticians and experimentalists to interpret different problems in real systems.

Overcoming cellular barriers for RNA therapeutics.

PubMed

Dowdy, Steven F

2017-03-01

RNA-based therapeutics, such as small-interfering (siRNAs), microRNAs (miRNAs), antisense oligonucleotides (ASOs), aptamers, synthetic mRNAs and CRISPR-Cas9, have great potential to target a large part of the currently undruggable genes and gene products and to generate entirely new therapeutic paradigms in disease, ranging from cancer to pandemic influenza to Alzheimer's disease. However, for these RNA modalities to reach their full potential, they first need to overcome a billion years of evolutionary defenses that have kept RNAs on the outside of cells from invading the inside of cells. Overcoming the lipid bilayer to deliver RNA into cells has remained the major problem to solve for widespread development of RNA therapeutics, but recent chemistry advances have begun to penetrate this evolutionary armor.

Enzyme decorated drug carriers: Targeted swords to cleave and overcome the mucus barrier.

PubMed

Menzel, Claudia; Bernkop-Schnürch, Andreas

2018-01-15

The use of mucus permeating drug carrier systems being able to overcome the mucus barrier can lead to a remarkable enhancement in bioavailability. One promising approach is the design of mucolytic enzyme decorated carrier systems (MECS). These systems include micro- and nanoparticles as well as self-emulsifying drug delivery systems (SEDDS) decorated with mucin cleaving enzymes such as papain (PAP) or bromelain (BRO). MECS are able to cross the mucus barrier in a comparatively efficient manner by cleaving mucus substructures in front of them on their way to the epithelium. Thereby these enzymes hydrolyze peptide bonds of mucus glycoproteins forming tiny holes or passages through the mucus. In various in vitro and in vivo studies MECS proved to be superior in their mucus permeating properties over nanocarriers without enzyme decoration. PAP decorated nanoparticles, for instance, remained 3h after oral administration to an even 2.5-fold higher extend in rat small intestine than the corresponding undecorated nanoparticles permeating the intestinal mucus gel layer to a much lower degree. As MECS break up the mucus network only locally without destroying its overall protective barrier function, even long term treatments with such systems seem feasible. Within this review article we address different drug carrier systems decorated with various types of enzymes, their particular pros and cons and potential applications. Copyright © 2017 Elsevier B.V. All rights reserved.

What Are the Barriers Which Discourage 15-16 Year-Old Girls from Participating in Team Sports and How Can We Overcome Them?

PubMed Central

Wetton, Abigail R.; Jones, Angela R.; Pearce, Mark S.

2013-01-01

Given the clear benefits of regular physical activity (such as reduced risks of cardiovascular disease and obesity, as well as other benefits including those related to mental health), exploration of the reasons that adolescent girls give for not taking part in team sports may be particularly valuable for enhancing later rates of participation. We combined questionnaires (n = 60) and semistructured interviews (n = 6) to assess the barriers that prevent 15-16-year-old girls from participating in extracurricular team games and what can be done to overcome these barriers and improve physical activity levels. Four barriers became prominent as to why girls in this sample do not participate: Internal Factors, Existing Stereotypes, Other Hobbies and Teachers. Methods to overcome these barriers were identified; changing teachers' attitudes and shifting the media's focus away from male sport. Following the successful summer Olympics and Paralympics in the UK, and the resulting positive focus on some of the nation's female athletes, a shift in focus may be possible. However, this needs to be maintained to allow girls more opportunities, role models and motivation to participate in sport. PMID:24073416

Implementing an intravenous insulin protocol in your practice: practical advice to overcome clinical, administrative, and financial barriers.

PubMed

Kelly, Janet L; Hirsch, Irl B; Furnary, Anthony P

2006-01-01

Diabetes mellitus is the fourth most common comorbid condition among hospitalized patients, and 30% of patients undergoing open-heart surgery have diabetes. The link between hyperglycemia and poor outcome has been well described, and large clinical trials have shown that aggressive control of blood glucose with an insulin infusion can improve these outcomes. The barriers to implementing an insulin infusion protocol are numerous, despite the fact that doing so is paramount to clinical success. Barriers include safety concerns, such as fear of hypoglycemia, insufficient nursing staff to patient ratios, lack of administrative and physician support, various system and procedural issues, and resistance to change. Key steps to overcome the barriers include building support with multidisciplinary champions, involving key staff, educating staff, and administrators of the clinical and economic benefits of improving glycemic control, setting realistic goals, selecting a validated insulin infusion protocol, and internally marketing the success of the protocol.

AccessAbility: Overcoming Information Barriers. Proceedings from the 1987 Spring Meeting of the Nebraska Library Association, College and University Section (Omaha, Nebraska, May 29, 1987).

ERIC Educational Resources Information Center

Kacena, Barbara J., Ed.

Various aspects of the theme, "AccessAbility: Overcoming Information Barriers," are considered in the conference papers collected in this document. They include: (1) "The Library Image: A Barrier to Accessibility" (Janice S. Boyer); (2) "The Educationally Disadvantaged Student: How Can the Library Help?" (Michael Poma…

Overcoming barriers to high performance seismic design using lessons learned from the green building industry

NASA Astrophysics Data System (ADS)

Glezil, Dorothy

NEHRP's Provisions today currently governing conventional seismic resistant design. These provisions, though they ensure the life-safety of building occupants, extensive damage and economic losses may still occur in the structures. This minimum performance can be enhanced using the Performance-Based Earthquake Engineering methodology and passive control systems like base isolation and energy dissipation systems. Even though these technologies and the PBEE methodology are effective reducing economic losses and fatalities during earthquakes, getting them implemented into seismic resistant design has been challenging. One of the many barriers to their implementation has been their upfront costs. The green building community has faced some of the same challenges that the high performance seismic design community currently faces. The goal of this thesis is to draw on the success of the green building industry to provide recommendations that may be used overcome the barriers that high performance seismic design (HPSD) is currently facing.

Overcoming Barriers in Unhealthy Settings

PubMed Central

Lemke, Michael K.; Meissen, Gregory J.; Apostolopoulos, Yorghos

2016-01-01

We investigated the phenomenon of sustained health-supportive behaviors among long-haul commercial truck drivers, who belong to an occupational segment with extreme health disparities. With a focus on setting-level factors, this study sought to discover ways in which individuals exhibit resiliency while immersed in endemically obesogenic environments, as well as understand setting-level barriers to engaging in health-supportive behaviors. Using a transcendental phenomenological research design, 12 long-haul truck drivers who met screening criteria were selected using purposeful maximum sampling. Seven broad themes were identified: access to health resources, barriers to health behaviors, recommended alternative settings, constituents of health behavior, motivation for health behaviors, attitude toward health behaviors, and trucking culture. We suggest applying ecological theories of health behavior and settings approaches to improve driver health. We also propose the Integrative and Dynamic Healthy Commercial Driving (IDHCD) paradigm, grounded in complexity science, as a new theoretical framework for improving driver health outcomes. PMID:28462332

Overcoming Barriers: Women in Superintendency

ERIC Educational Resources Information Center

Miller, Claire M.

2009-01-01

Women currently represent the largest number of teachers in the United States but remain underrepresented in the superintendent position. This suggests that the superintendency has been influenced by patriarchy. If women are to break through the barriers that prevent them from attaining a superintendency, we will need to understand the social…

Overcoming Barriers to the Market Access of Biosimilars in the European Union: The Case of Biosimilar Monoclonal Antibodies.

PubMed

Moorkens, Evelien; Jonker-Exler, Clara; Huys, Isabelle; Declerck, Paul; Simoens, Steven; Vulto, Arnold G

2016-01-01

In 2014, six of the top ten blockbuster medicines were monoclonal antibodies. This multibillion-dollar market with expiring patents is the main driver for the development of biosimilar mAbs. With the ever-increasing cost of healthcare and the economic pressure to reduce or sustain healthcare expenses, biosimilars could be instrumental in reducing costs for medication and increasing patient access to treatment. The aim of this study is to identify and describe the barriers to market access of biosimilar mAbs in the European Union and to analyze how these barriers could be overcome. A narrative literature review was carried out using the databases PubMed, Embase, and EconLit. Studies were published in English or Dutch. Additionally, the reference list of the articles was checked for relevant studies. Articles and conference papers known to the authors were included as well. Articles were also identified by searching on the website of the Generics and Biosimilars Initiative (GaBI) journal. Six barriers were identified based on available literature: The manufacturing process, the regulatory process, intellectual property rights, lack of incentive, the impossibility of substitution, and the innovator's reach. These six barriers are presented as a possible framework to study the market access of biosimilar mAbs. Based on the literature search, recommendations can be made to overcome these barriers: (i) invest initially in advanced production processes with the help of single-use technology, experience or outsourcing (ii) gain experience with the regulatory process and establish alignment between stakeholders (iii) limit patent litigation, eliminate evergreening benefits, build out further the unitary patent and unified patent litigation system within the EU (iv) create demand-side policies, disseminate objective information (v) change attitude toward biosimilar switching/substitution, starting with physician, and patient education (vi) differentiate the biosimilar by

Overcoming Barriers to the Market Access of Biosimilars in the European Union: The Case of Biosimilar Monoclonal Antibodies

PubMed Central

Moorkens, Evelien; Jonker-Exler, Clara; Huys, Isabelle; Declerck, Paul; Simoens, Steven; Vulto, Arnold G.

2016-01-01

Background: In 2014, six of the top ten blockbuster medicines were monoclonal antibodies. This multibillion-dollar market with expiring patents is the main driver for the development of biosimilar mAbs. With the ever-increasing cost of healthcare and the economic pressure to reduce or sustain healthcare expenses, biosimilars could be instrumental in reducing costs for medication and increasing patient access to treatment. Objectives: The aim of this study is to identify and describe the barriers to market access of biosimilar mAbs in the European Union and to analyze how these barriers could be overcome. Methods: A narrative literature review was carried out using the databases PubMed, Embase, and EconLit. Studies were published in English or Dutch. Additionally, the reference list of the articles was checked for relevant studies. Articles and conference papers known to the authors were included as well. Articles were also identified by searching on the website of the Generics and Biosimilars Initiative (GaBI) journal. Results: Six barriers were identified based on available literature: The manufacturing process, the regulatory process, intellectual property rights, lack of incentive, the impossibility of substitution, and the innovator's reach. These six barriers are presented as a possible framework to study the market access of biosimilar mAbs. Based on the literature search, recommendations can be made to overcome these barriers: (i) invest initially in advanced production processes with the help of single-use technology, experience or outsourcing (ii) gain experience with the regulatory process and establish alignment between stakeholders (iii) limit patent litigation, eliminate evergreening benefits, build out further the unitary patent and unified patent litigation system within the EU (iv) create demand-side policies, disseminate objective information (v) change attitude toward biosimilar switching/substitution, starting with physician, and patient

Protein unfolding with a steric trap.

PubMed

Blois, Tracy M; Hong, Heedeok; Kim, Tae H; Bowie, James U

2009-10-07

The study of protein folding requires a method to drive unfolding, which is typically accomplished by altering solution conditions to favor the denatured state. This has the undesirable consequence that the molecular forces responsible for configuring the polypeptide chain are also changed. It would therefore be useful to develop methods that can drive unfolding without the need for destabilizing solvent conditions. Here we introduce a new method to accomplish this goal, which we call steric trapping. In the steric trap method, the target protein is labeled with two biotin tags placed close in space so that both biotin tags can only be bound by streptavidin when the protein unfolds. Thus, binding of the second streptavidin is energetically coupled to unfolding of the target protein. Testing the method on a model protein, dihydrofolate reductase (DHFR), we find that streptavidin binding can drive unfolding and that the apparent binding affinity reports on changes in DHFR stability. Finally, by employing the slow off-rate of wild-type streptavidin, we find that DHFR can be locked in the unfolded state. The steric trap method provides a simple method for studying aspects of protein folding and stability in native solvent conditions, could be used to specifically unfold selected domains, and could be applicable to membrane proteins.

Preparing Dental Students and Residents to Overcome Internal and External Barriers to Evidence-Based Practice.

PubMed

Coleman, Brandon G; Johnson, Thomas M; Erley, Kenneth J; Topolski, Richard; Rethman, Michael; Lancaster, Douglas D

2016-10-01

In recent years, evidence-based dentistry has become the ideal for research, academia, and clinical practice. However, barriers to implementation are many, including the complexity of interpreting conflicting evidence as well as difficulties in accessing it. Furthermore, many proponents of evidence-based care seem to assume that good evidence consistently exists and that clinicians can and will objectively evaluate data so as to apply the best evidence to individual patients' needs. The authors argue that these shortcomings may mislead many clinicians and that students should be adequately prepared to cope with some of the more complex issues surrounding evidence-based practice. Cognitive biases and heuristics shape every aspect of our lives, including our professional behavior. This article reviews literature from medicine, psychology, and behavioral economics to explore the barriers to implementing evidence-based dentistry. Internal factors include biases that affect clinical decision making: hindsight bias, optimism bias, survivor bias, and blind-spot bias. External factors include publication bias, corporate bias, and lack of transparency that may skew the available evidence in the peer-reviewed literature. Raising awareness of how these biases exert subtle influence on decision making and patient care can lead to a more nuanced discussion of addressing and overcoming barriers to evidence-based practice.

Steric and Electronic Effects of Bidentate Phosphine Ligands on Ruthenium(II)-Catalyzed Hydrogenation of Carbon Dioxide.

PubMed

Zhang, Pan; Ni, Shao-Fei; Dang, Li

2016-09-20

The reactivity difference between the hydrogenation of CO2 catalyzed by various ruthenium bidentate phosphine complexes was explored by DFT. In addition to the ligand dmpe (Me2 PCH2 CH2 PMe2 ), which was studied experimentally previously, a more bulky diphosphine ligand, dmpp (Me2 PCH2 CH2 CH2 PMe2 ), together with a more electron-withdrawing diphosphine ligand, PN(Me) P (Me2 PCH2 N(Me) CH2 PMe2 ), have been studied theoretically to analyze the steric and electronic effects on these catalyzed reactions. Results show that all of the most favorable pathways for the hydrogenation of CO2 catalyzed by bidentate phosphine ruthenium dihydride complexes undergo three major steps: cis-trans isomerization of ruthenium dihydride complex, CO2 insertion into the Ru-H bond, and H2 insertion into the ruthenium formate ion. Of these steps, CO2 insertion into the Ru-H bond has the lowest barrier compared with the other two steps in each preferred pathway. For the hydrogenation of CO2 catalyzed by ruthenium complexes of dmpe and dmpp, cis-trans isomerization of ruthenium dihydride complex has a similar barrier to that of H2 insertion into the ruthenium formate ion. However, in the reaction catalyzed by the PN(Me) PRu complex, cis-trans isomerization of the ruthenium dihydride complex has a lower barrier than H2 insertion into the ruthenium formate ion. These results suggest that the steric effect caused by the change of the outer sphere of the diphosphine ligand on the reaction is not clear, although the electronic effect is significant to cis-trans isomerization and H2 insertion. This finding refreshes understanding of the mechanism and provides necessary insights for ligand design in transition-metal-catalyzed CO2 transformation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Overcoming Barriers to Shared Decision Making

MedlinePlus

... a social worker can help. Barrier: Language differences Solution: More than 13 million people in the U.S. age 5 and older speak little or no English, according to the U.S. Census Bureau. Some hospitals ...

Steric and electrostatic surface forces on sulfonated PEG graft surfaces with selective albumin adsorption.

PubMed

Bremmell, Kristen E; Britcher, Leanne; Griesser, Hans J

2013-06-01

Addition of ionized terminal groups to PEG graft layers may cause additional interfacial forces to modulate the net interfacial interactions between PEG graft layers and proteins. In this study we investigated the effect of terminal sulfonate groups, characterizing PEG-aldehyde (PEG-CHO) and sulfonated PEG (PEG-SO3) graft layers by XPS and colloid probe AFM interaction force measurements as a function of ionic strength, in order to determine surface forces relevant to protein resistance and models of bio-interfacial interaction of such graft coatings. On the PEG-CHO surface the measured interaction force does not alter with ionic strength, typical of a repulsive steric barrier coating. An analogous repulsive interaction force of steric origin was also observed on the PEG-SO3 graft coating; however, the net interaction force changed with ionic strength. Interaction forces were modelled by steric and electrical double layer interaction theories, with fitting to a scaling theory model enabling determination of the spacing and stretching of the grafted chains. Albumin, fibrinogen, and lysozyme did not adsorb on the PEG-CHO coating, whereas the PEG graft with terminal sulfonate groups showed substantial adsorption of albumin but not fibrinogen or lysozyme from 0.15 M salt solutions. Under lower ionic strength conditions albumin adsorption was again minimized as a result of the increased electrical double-layer interaction observed with the PEG-SO3 modified surface. This unique and unexpected adsorption behaviour of albumin provides an alternative explanation to the "negative cilia" model used by others to rationalize observed thromboresistance on PEG-sulfonate coatings. Copyright © 2013 Elsevier B.V. All rights reserved.

Physicochemical properties of polymers: An important system to overcome the cell barriers in gene transfection.

PubMed

Namvar, Ali; Bolhassani, Azam; Khairkhah, Niloofardokht; Motevalli, Fatemeh

2015-07-01

Delivery of the macromolecules including DNA, miRNA, and antisense oligonucleotides is typically mediated by carriers due to the large size and negative charge. Different physical (e.g., gene gun or electroporation), and chemical (e.g., cationic polymer or lipid) vectors have been already used to improve the efficiency of gene transfer. Polymer-based DNA delivery systems have attracted special interest, in particular via intravenous injection with many intra- and extracellular barriers. The recent progress has shown that stimuli-responsive polymers entitled as multifunctional nucleic acid vehicles can act to target specific cells. These nonviral carriers are classified by the type of stimulus including reduction potential, pH, and temperature. Generally, the physicochemical characterization of DNA-polymer complexes is critical to enhance the transfection potency via protection of DNA from nuclease digestion, endosomal escape, and nuclear localization. The successful clinical applications will depend on an exact insight of barriers in gene delivery and development of carriers overcoming these barriers. Consequently, improvement of novel cationic polymers with low toxicity and effective for biomedical use has attracted a great attention in gene therapy. This article summarizes the main physicochemical and biological properties of polyplexes describing their gene transfection behavior, in vitro and in vivo. In this line, the relative efficiencies of various cationic polymers are compared. © 2015 Wiley Periodicals, Inc.

Barriers that practitioners face when initiating insulin therapy in general practice settings and how they can be overcome

PubMed Central

Bin rsheed, Abdulaziz; Chenoweth, Ian

2017-01-01

AIM To explore primary care physicians’ perspectives on possible barriers to the use of insulin. METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight electronic databases were searched (between January 1, 1994 and August 31, 2014) for relevant studies. A search for grey literature and a review of the references in the retrieved studies were also conducted. Studies that focused on healthcare providers’ perspectives on possible barriers to insulin initiation with type 2 diabetic patients were included, as well as articles suggesting solutions for these barriers. Review articles and studies that only considered patients’ perspectives were excluded. RESULTS A total of 19 studies met the inclusion criteria and were therefore included in this study: 10 of these studies used qualitative methods, 8 used quantitative methods and 1 used mixed methods. Studies included a range of different health care settings. The findings are reported under four broad categories: The perceptions of primary care physicians about the barriers to initiate insulin therapy for type 2 diabetes patients, how primary care physicians assess patients prior to initiating insulin, professional roles and possible solutions to overcome these barriers. The barriers described were many and covered doctor, patient, system and technological aspects. Interventions that focused on doctor training and support, or IT-based decision support were few, and did not result in significant improvement. CONCLUSION Primary care physicians’ known delay in insulin initiation is multifactorial. Published reports of attempts to find solutions for these barriers were limited in number. PMID:28138362

Creating sustainable local health information exchanges: can barriers to stakeholder participation be overcome?

PubMed

Grossman, Joy M; Kushner, Kathryn L; November, Elizabeth A

2008-02-01

Local health information exchanges (HIEs) hold the promise of collecting patient clinical data across sites of care to provide more complete and timely information for treatment, as well as supporting quality improvement and reporting, public health activities, and clinical research. Findings from a study of stakeholder perspectives on participation in four HIEs by the Center for Studying Health System Change (HSC) and the National Institute for Health Care Management (NIHCM) Foundation suggest, however, that barriers to achieving data exchange remain high. Concerns about loss of competitive advantage and data misuse impede provider and health plan willingness to contribute patient data. Additionally, uncertainty about who benefits from HIEs is affecting stakeholder willingness to fund the exchanges. The more mature exchanges--Cincinnati-based HealthBridge and the Indiana Health Information Exchange (IHIE)--have achieved some viability by meeting a specific business need--more efficient delivery of hospital test results to physicians. The newer exchanges--CareSpark, serving northeast Tennessee and southwest Virginia, and the Tampa Bay Regional Health Information Organization (RHIO)--have struggled to identify and finance initial services without a similar critical mass of hospital participation. While narrow data exchange efforts that improve transaction efficiency may be a pragmatic first step to overcome barriers to stakeholder participation, expanding HIEs to achieve the broad-based data exchange necessary for quality reporting and pay-for-performance (P4P) activities raises more challenges.

Psychology of Success: Overcoming Barriers to Pursuing Further Education

ERIC Educational Resources Information Center

Goto, Stanford T.; Martin, Connie

2009-01-01

Of the many barriers that prevent adults from continuing their education, psychological barriers are least often addressed by educators. This is an important area of concern because psychological factors influence how prospective students respond to other barriers. This qualitative study was conducted to describe how adults negotiate…

Overcoming autopsy barriers in pediatric cancer research.

PubMed

Alabran, Jennifer L; Hooper, Jody E; Hill, Melissa; Smith, Sandra E; Spady, Kimberlee K; Davis, Lara E; Peterson, Lauren S; Malempati, Suman; Ryan, Christopher W; Acosta, Rae; Spunt, Sheri L; Keller, Charles

2013-02-01

More than 13,000 children annually in the United States and Canada under the age of 20 will be diagnosed with cancer at a mortality approaching 20% 1,2. Tumor samples obtained by autopsy provide an innovative way to study tumor progression, potentially aiding in the discovery of new treatments and increased survival rates. The purpose of this study was to identify barriers to autopsies and develop guidelines for requesting autopsies for research purposes. Families of children treated for childhood cancer were referred by patient advocacy groups and surveyed about attitudes and experiences with research autopsies. From 60 interviews, barriers to autopsy and tumor banking were identified. An additional 14 interviews were conducted with medical and scientific experts. Ninety-three percent of parents of deceased children did or would have consented to a research autopsy if presented with the option; however, only half of these families were given the opportunity to donate autopsy tissue for research. The most significant barriers were the physicians' reluctance to ask a grieving family and lack of awareness about research opportunities. The value of donating tumor samples to research via an autopsy should be promoted to all groups managing pediatric cancer patients. Not only does autopsy tumor banking offer a potentially important medical and scientific impact, but the opportunity to contribute this Legacy Gift of autopsy tumor tissue also creates a positive outlet for the grieving family. Taking these findings into account, our multidisciplinary team has developed a curriculum addressing key barriers. Copyright © 2012 Wiley Periodicals, Inc.

Rural Veteran Access to Healthcare Services: Investigating the Role of Information and Communication Technologies in Overcoming Spatial Barriers

PubMed Central

Schooley, Benjamin L; Horan, Thomas A; Lee, Pamela W; West, Priscilla A

2010-01-01

This multimethod pilot study examined patient and practitioner perspectives on the influence of spatial barriers to healthcare access and the role of health information technology in overcoming these barriers. The study included a survey administered to patients attending a Department of Veterans Affairs (VA) health visit, and a focus group with VA care providers. Descriptive results and focus group findings are presented. Spatial distance is a significant factor for many rural veterans when seeking healthcare. For this sample of rural veterans, a range of telephone, computer, and Internet technologies may become more important for accessing care as Internet access becomes more ubiquitous and as younger veterans begin using the VA health system. The focus group highlighted the negative impact of distance, economic considerations, geographic barriers, and specific medical conditions on access to care. Lack of adequate technology infrastructure was seen as an obstacle to utilization. This study discusses the need to consider distance, travel modes, age, and information technology infrastructure and adoption when designing health information technology to care for rural patients. PMID:20697468

Advocating for responsible oil and natural gas extraction policies; FracTracker as a mechanism for overcoming the barriers to scientific advocacy for academics and communities

NASA Astrophysics Data System (ADS)

Ferrar, K. J.; Malone, S.; Kelso, M.; Lenker, B.

2013-12-01

The inability to translate data to scientific information that can readily be incorporated by citizens into the public arena is an obstacle for science-based advocacy. This issue is particularly poignant for shale oil and natural gas development via hydraulic fracturing, as the issue has become highly politicized. Barriers to engaging in policy debate are different but highly related for community members and scientists. For citizens and interest groups, barriers including accessibility, public awareness and data presentation limit the motivation for community involvement in political interactions. To overcome such barriers, social researchers call for public engagement to move upstream and many call for a broad engagement of scientists in science-based advocacy. Furthermore surveys have shown that citizens, interest groups, and decision-makers share a broad desire for scientists to engage in environmental policy development. Regardless, scientists face a number of perceived barriers, with academics expressing the most resistance to overcoming the tension created by adherence to the scientific method and the need to engage with the broader society, described by Schneider (1990) as the 'double ethical bind'. For the scientific community the appeal of public dissemination of information beyond the scope of academic journals is limited for a number of reasons. Barriers include preservation of credibility, peer attitudes, training, and career trajectory. The result is a lack of translated information available to the public. This systematic analysis of the FracTracker platform provides an evaluation of where the features of the public engagement, GIS platform has been successful at overcoming these barriers to public dissemination, where the platform needs further development or is ill-suited to address these issues, and the development of FracTracker as an outlet for scientific researchers to engage with citizens. The analysis will also provide insight into what

Steric hindrances create a discrete linear Dy4 complex exhibiting SMM behaviour.

PubMed

Lin, Shuang-Yan; Zhao, Lang; Ke, Hongshan; Guo, Yun-Nan; Tang, Jinkui; Guo, Yang; Dou, Jianmin

2012-03-21

Two linear tetranuclear lanthanide complexes of general formula [Ln(4)(L)(2)(C(6)H(5)COO)(12)(MeOH)(4)], where HL = 2,6-bis((furan-2-ylmethylimino)methyl)-4-methylphenol, () and Ln(III) = Dy(III) (1) and Gd(III) (2), have been synthesized and characterized. The crystal structural analysis demonstrates that two Schiff-base ligands inhibit the growth of benzoate bridged 1D chains, leading to the isolation of discrete tetranuclear complexes due to their steric hindrances. Every Ln(III) ion is coordinated by eight donor atoms in a distorted bicapped trigonal-prismatic arrangement. Alternating current (ac) susceptibility measurements of complex 1 reveal a frequency- and temperature-dependent out-of-phase signal under zero dc field, typical of single-molecule magnet (SMM) behaviour with an anisotropic barrier Δ(eff) = 17.2 K.

Overcoming barriers to implementing patient-reported outcomes in an electronic health record: a case report.

PubMed

Harle, Christopher A; Listhaus, Alyson; Covarrubias, Constanza M; Schmidt, Siegfried Of; Mackey, Sean; Carek, Peter J; Fillingim, Roger B; Hurley, Robert W

2016-01-01

In this case report, the authors describe the implementation of a system for collecting patient-reported outcomes and integrating results in an electronic health record. The objective was to identify lessons learned in overcoming barriers to collecting and integrating patient-reported outcomes in an electronic health record. The authors analyzed qualitative data in 42 documents collected from system development meetings, written feedback from users, and clinical observations with practice staff, providers, and patients. Guided by the Unified Theory on the Adoption and Use of Information Technology, 5 emergent themes were identified. Two barriers emerged: (i) uncertain clinical benefit and (ii) time, work flow, and effort constraints. Three facilitators emerged: (iii) process automation, (iv) usable system interfaces, and (v) collecting patient-reported outcomes for the right patient at the right time. For electronic health record-integrated patient-reported outcomes to succeed as useful clinical tools, system designers must ensure the clinical relevance of the information being collected while minimizing provider, staff, and patient burden. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Poisson-Nernst-Planck equations with steric effects - non-convexity and multiple stationary solutions

NASA Astrophysics Data System (ADS)

Gavish, Nir

2018-04-01

We study the existence and stability of stationary solutions of Poisson-Nernst-Planck equations with steric effects (PNP-steric equations) with two counter-charged species. We show that within a range of parameters, steric effects give rise to multiple solutions of the corresponding stationary equation that are smooth. The PNP-steric equation, however, is found to be ill-posed at the parameter regime where multiple solutions arise. Following these findings, we introduce a novel PNP-Cahn-Hilliard model, show that it is well-posed and that it admits multiple stationary solutions that are smooth and stable. The various branches of stationary solutions and their stability are mapped utilizing bifurcation analysis and numerical continuation methods.

A Social Constructionist Inquiry Study on the Lived Experiences of Educators with Dyslexia Overcoming Workplace Barriers and Increasing Their Capacity for Success

ERIC Educational Resources Information Center

Taylor, Kathryn R.

2017-01-01

The purpose of this qualitative research is to journey the lives of educators with dyslexia growing up as K-12 students, working in the K-12 educational environment, and the means by which those educators overcome workplace barriers as analyzed by three guidelines under the Universal Design for Learning (UDL) principle, multiple means of…

Unlocking the sugar "steric gate" of DNA polymerases.

PubMed

Brown, Jessica A; Suo, Zucai

2011-02-22

To maintain genomic stability, ribonucleotide incorporation during DNA synthesis is controlled predominantly at the DNA polymerase level. A steric clash between the 2'-hydroxyl of an incoming ribonucleotide and a bulky active site residue, known as the "steric gate", establishes an effective mechanism for most DNA polymerases to selectively insert deoxyribonucleotides. Recent kinetic, structural, and in vivo studies have illuminated novel features about ribonucleotide exclusion and the mechanistic consequences of ribonucleotide misincorporation on downstream events, such as the bypass of a ribonucleotide in a DNA template and the subsequent extension of the DNA lesion bypass product. These important findings are summarized in this review.

Cosmetic dermatologic surgical training in US dermatology residency programs: identifying and overcoming barriers.

PubMed

Bauer, Bruce; Williams, Erin; Stratman, Erik J

2014-02-01

The public and other medical specialties expect dermatologists who offer cosmetic dermatology services to provide competent care. There are numerous barriers to achieving cosmetic dermatology competency during residency. Many dermatology residents enter the workforce planning to provide cosmetic services. If a training gap exists, this may adversely affect patient safety. To identify resources available for hands-on cosmetic dermatology training in US dermatology residency training programs and to assess program director (PD) attitudes toward cosmetic dermatology training during residency and strategies, including discounted pricing, used by training programs to overcome barriers related to resident-performed cosmetic dermatology procedures. An online survey in academic dermatology practices among PDs of US dermatology residency programs. Frequency of cosmetic dermatology devices and injectables used for dermatology resident hands-on cosmetic dermatology training, categorizing PD attitudes toward cosmetic dermatology training during residency and describing residency-related discounted pricing models. Responses from PDs were received from 53 of 114 (46%) US dermatology residency programs. All but 3 programs (94%) offered hands-on cosmetic dermatology training using botulinum toxin, and 47 of 53 (89%) provided training with hyaluronic acid fillers. Pulsed dye lasers represented the most common laser use experienced by residents (41 of 52 [79%]), followed by Q-switched Nd:YAG (30 of 52 [58%]). Discounted procedures were offered by 32 of 53 (60%) programs, with botulinum toxin (30 of 32 [94%]) and fillers (27 of 32 [84%]) most prevalent and with vascular lasers (17 of 32 [53%]) and hair removal lasers (12 of 32 [38%]) less common. Various discounting methods were used. Only 20 of 53 (38%) PDs believed that cosmetic dermatology should be a necessary aspect of residency training; 14 of 52 (27%) PDs thought that residents should not be required to perform any cosmetic

SOLUTIONS TO OVERCOME BARRIERS TO IMPLEMENTATION OF TREATMENT TECHNOLOGIES

EPA Science Inventory

To make treatment a viable option for remediation you must first identify the barriers to implementing treatment. The primary barrier is economics. Treatment options are relatively expensive and there is a lack of funds for treatment. The cost of technologies can be lowered by 1)...

Brownian dynamics of sterically-stabilized colloidal suspensions

DOE Office of Scientific and Technical Information (OSTI.GOV)

TeGrotenhuis, W.E.; Radke, C.J.; Denn, M.M.

1994-02-01

One application where microstructure plays a critical role is in the production of specialty ceramics, where colloidal suspensions act as precursors; here the microstructure influences the structural, thermal, optical and electrical properties of the ceramic products. Using Brownian dynamics, equilibrium and dynamic properties are calculated for colloidal suspensions that are stabilized through the Milner, Witten and Cates (1988) steric potential. Results are reported for osmotic pressures, radial distributions functions, static structure factors, and self-diffusion coefficients. The sterically-stabilized systems are also approximated by equivalent hard spheres, with good agreement for osmotic pressure and long-range structure. The suitability of the potential tomore » model the behavior of a real system is explored by comparing static structure factors calculated from Brownian dynamics simulations to those measured using SANS. Finally, the effects of Hamaker and hydrodynamic forces on calculated properties are investigated.« less

Transformed Science: Overcoming Barriers of Inequality and Mistrust to Pursue the Agenda of Underrepresented Communities

NASA Astrophysics Data System (ADS)

Lyons, Renee

Educational programs created to provide opportunities for all, in reality often reflect social inequalities. Such is the case for Public Participation in Scientific Research (PPSR) Projects. PPSR projects have been proposed as an effective way to engage more diverse audiences in science, yet the demographics of PPSR participants do not correspond with the demographic makeup of the United States. The field of PPSR as a whole has struggled to recruit low SES and underrepresented populations to participate in project research efforts. This research study explores factors, which may be affecting an underrepresented community's willingness to engage in scientific research and provides advice from PPSR project leaders in the field, who have been able to engage underrepresented communities in scientific research, on how to overcome these barriers. Finally the study investigates the theoretical construct of a Third Space within a PPSR project. The research-based recommendations for PPSR projects desiring to initiate and sustain research partnerships with underrepresented communities well align with the theoretical construct of a Third Space. This study examines a specific scientific research partnership between an underrepresented community and scientific researchers to examine if and to what extent a Third Space was created. Using qualitative methods to understand interactions and processes involved in initiating and sustaining a scientific research partnership, this study provides advice on how PPSR research partnerships can engage underrepresented communities in scientific research. Study results show inequality and mistrust of powerful institutions stood as participation barriers for underrepresented community members. Despite these barriers PPSR project leaders recommend barriers can be confronted by open dialogue with communities about the abuse and alienation they have faced, by signaling respect for the community, and by entering the community through someone the

“My hair or my health”: Overcoming Barriers to Physical Activity in African American women with a focus on hairstyle-related factors

PubMed Central

Huebschmann, Amy G.; Campbell, Lucille Johnson; Brown, Candace S.; Dunn, Andrea L.

2016-01-01

Physical activity disparities among African American (AA) women may be related to sociocultural barriers, including difficulties with restyling hair after exercise. We sought to identify physical activity barriers and facilitators in AA women with a focus on sociocultural factors related to hairstyle maintenance. Participants (n=51) were AA women aged 19–73 years who completed valid surveys and participated in structured focus groups, stratified by age and physical activity levels, from 11/2012 to 2/2013. The Constant Comparison method was used to develop qualitative themes for barriers and facilitators. The most frequently reported general physical activity barrier among exercisers was “lack of money” (27%) and among non-exercisers was “lack of self-discipline” (57%). A hairstyle-related barrier of “sweating out my hairstyle,” was reported by 7% of exercisers and 29% of non-exercisers. This hairstyle-related barrier included the need for extra time and money to restyle hair due to perspiration. Hairstyle-related facilitators included: prioritizing health over hairstyle and high self-efficacy to restyle hair after perspiration. Participants were interested in resources to simplify hairstyle maintenance. AA women whose hairstyle is affected by perspiration may avoid physical activity due to time and financial burdens. Increasing self-efficacy to restyle hair after perspiration may help to overcome this barrier. PMID:26495938

Unlocking the Sugar ‘Steric Gate’ of DNA Polymerases†

PubMed Central

Brown, Jessica A.; Suo, Zucai

2011-01-01

To maintain genomic stability, ribonucleotide incorporation during DNA synthesis is controlled predominantly at the DNA polymerase level. A steric clash between the 2′-hydroxyl of an incoming ribonucleotide and a bulky active site residue, known as the ‘steric gate’, establishes an effective mechanism for most DNA polymerases to selectively insert deoxyribonucleotides. Recent kinetic, structural, and in vivo studies have illuminated novel features about ribonucleotide exclusion and the mechanistic consequences of ribonucleotide misincorporation on downstream events, such as the bypass of a ribonucleotide in a DNA template and the subsequent extension of the DNA lesion bypass product. These important findings are summarized in this review article. PMID:21226515

Overcoming barriers to membrane protein structure determination.

PubMed

Bill, Roslyn M; Henderson, Peter J F; Iwata, So; Kunji, Edmund R S; Michel, Hartmut; Neutze, Richard; Newstead, Simon; Poolman, Bert; Tate, Christopher G; Vogel, Horst

2011-04-01

After decades of slow progress, the pace of research on membrane protein structures is beginning to quicken thanks to various improvements in technology, including protein engineering and microfocus X-ray diffraction. Here we review these developments and, where possible, highlight generic new approaches to solving membrane protein structures based on recent technological advances. Rational approaches to overcoming the bottlenecks in the field are urgently required as membrane proteins, which typically comprise ~30% of the proteomes of organisms, are dramatically under-represented in the structural database of the Protein Data Bank.

Use of steric encumbrance to develop conjugated nanoporous polymers for metal-free catalytic hydrogenation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Chengcheng; Zhu, Xiang; Abney, Carter W.

The design and synthesis of metal-free heterogeneous catalysts for efficient hydrogenation remains a great challenge. Here we report a novel approach to create conjugated nanoporous polymers with efficient hydrogenation activities toward unsaturated ketones by leveraging the innate steric encumbrance. The steric bulk of the framework as well as the local sterics of the Lewis basic sites within the polymeric skeleton result in the generation of the putative catalyst. This approach opens up new possibilities for the development of innovative metal-free heterogeneous catalysts.

Use of steric encumbrance to develop conjugated nanoporous polymers for metal-free catalytic hydrogenation

DOE PAGES

Tian, Chengcheng; Zhu, Xiang; Abney, Carter W.; ...

2016-09-08

The design and synthesis of metal-free heterogeneous catalysts for efficient hydrogenation remains a great challenge. Here we report a novel approach to create conjugated nanoporous polymers with efficient hydrogenation activities toward unsaturated ketones by leveraging the innate steric encumbrance. The steric bulk of the framework as well as the local sterics of the Lewis basic sites within the polymeric skeleton result in the generation of the putative catalyst. Lastly, this approach opens up new possibilities for the development of innovative metal-free heterogeneous catalysts.

Use of steric encumbrance to develop conjugated nanoporous polymers for metal-free catalytic hydrogenation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tian, Chengcheng; Zhu, Xiang; Abney, Carter W.

The design and synthesis of metal-free heterogeneous catalysts for efficient hydrogenation remains a great challenge. Here we report a novel approach to create conjugated nanoporous polymers with efficient hydrogenation activities toward unsaturated ketones by leveraging the innate steric encumbrance. The steric bulk of the framework as well as the local sterics of the Lewis basic sites within the polymeric skeleton result in the generation of the putative catalyst. Lastly, this approach opens up new possibilities for the development of innovative metal-free heterogeneous catalysts.

Overcoming the barrier of narrative adherence in conflicts through awareness of the psychological bias of naïve realism.

PubMed

Nasie, Meytal; Bar-Tal, Daniel; Pliskin, Ruthie; Nahhas, Eman; Halperin, Eran

2014-11-01

One significant socio-psychological barrier for peaceful resolution of conflicts is each party's adherence to its own collective narrative. We hypothesized that raising awareness to the psychological bias of naïve realism and its identification in oneself would provide a path to overcoming this barrier, thus increasing openness to the adversary's narrative. We conducted three experimental studies in the context of the Israeli-Palestinian conflict. Studies 1 and 2, conducted among Jewish Israelis and Palestinian Israelis, respectively, revealed that participants with hawkish political ideology reported greater openness to the adversary's narrative when they were made aware of naïve realism bias. Study 3 revealed that hawkish participants at the baseline adhered to the ingroup narrative and resisted the adversary's narrative more than dovish participants. They were also more able to identify the bias in themselves upon learning about it. This identification may explain why the manipulation led to bias correction only among hawkish participants. © 2014 by the Society for Personality and Social Psychology, Inc.

Sulfur-Specific Microbial Desulfurization of Sterically Hindered Analogs of Dibenzothiophene

PubMed Central

Lee, M. K.; Senius, J. D.; Grossman, M. J.

1995-01-01

Dibenzothiophenes (DBTs) bearing alkyl substitutions adjacent to the sulfur atom, such as 4,6-diethyldibenzothiophene (4,6-DEDBT), are referred to as sterically hindered with regard to access to the sulfur moiety. By using enrichment cultures with 4,6-DEDBT as the sole sulfur source, bacterial isolates which selectively remove sulfur from sterically hindered DBTs were obtained. The isolates were tentatively identified as Arthrobacter species. 4,6-DEDBT sulfone was shown to be an intermediate in the 4,6-DEDBT desulfurization pathway, and 2-hydroxy-3,3(prm1)-diethylbiphenyl (HDEBP) was identified as the sulfur-free end product. PMID:16535189

WSB1 overcomes oncogene-induced senescence by targeting ATM for degradation

PubMed Central

Kim, Jung Jin; Lee, Seung Baek; Yi, Sang-Yeop; Han, Sang-Ah; Kim, Sun-Hyun; Lee, Jong-Min; Tong, Seo-Yun; Yin, Ping; Gao, Bowen; Zhang, Jun; Lou, Zhenkun

2017-01-01

Oncogene-induced senescence (OIS) or apoptosis through the DNA-damage response is an important barrier of tumorigenesis. Overcoming this barrier leads to abnormal cell proliferation, genomic instability, and cellular transformation, and finally allows cancers to develop. However, it remains unclear how the OIS barrier is overcome. Here, we show that the E3 ubiquitin ligase WD repeat and SOCS box-containing protein 1 (WSB1) plays a role in overcoming OIS. WSB1 expression in primary cells helps the bypass of OIS, leading to abnormal proliferation and cellular transformation. Mechanistically, WSB1 promotes ATM ubiquitination, resulting in ATM degradation and the escape from OIS. Furthermore, we identify CDKs as the upstream kinase of WSB1. CDK-mediated phosphorylation activates WSB1 by promoting its monomerization. In human cancer tissue and in vitro models, WSB1-induced ATM degradation is an early event during tumorigenic progression. We suggest that WSB1 is one of the key players of early oncogenic events through ATM degradation and destruction of the tumorigenesis barrier. Our work establishes an important mechanism of cancer development and progression in premalignant lesions. PMID:27958289

Nucleophilic substitution at silicon (SN2@Si) via a central reaction barrier.

PubMed

Bento, A Patrícia; Bickelhaupt, F Matthias

2007-03-16

It is textbook knowledge that nucleophilic substitution at carbon (SN2@C) proceeds via a central reaction barrier which disappears in the corresponding nucleophilic substitution reaction at silicon (SN2@Si). Here, we address the question why the central barrier disappears from SN2@C to SN2@Si despite the fact that these processes are isostructural and isoelectronic. To this end, we have explored and analyzed the potential energy surfaces (PES) of various Cl-+CR3Cl (R=H, CH3) and Cl-+SiR3Cl model reactions (R=H, CH3, C2H5, and OCH3). Our results show that the nature of the SN2 reaction barrier is in essence steric, but that it can be modulated by electronic factors. Thus, simply by increasing the steric demand of the substituents R around the silicon atom, the SN2@Si mechanism changes from its regular single-well PES (with a stable intermediate transition complex, TC), via a triple-well PES (with a pre- and a post-TS before and after the central TC), to a double-well PES (with a TS; R=OCH3), which is normally encountered for SN2@C reactions.

Avoiding Steric Congestion in Dendrimer Growth through Proportionate Branching. A Twist on da Vinci's Rule of Tree Branching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Xuyi; Taraban, Marc B.; Hyland, Laura L.

2012-10-05

In making defect-free macromolecules, the challenge occurs during chemical synthesis. This challenge is especially pronounced in dendrimer synthesis where exponential growth quickly leads to steric congestion. To overcome this difficulty, proportionate branching in dendrimer growth is proposed. In proportionate branching, both the number and the length of branches increase exponentially but in opposite directions to mimic tree growth. The effectiveness of this strategy is demonstrated through the synthesis of a fluorocarbon dendron containing 243 chemically identical fluorine atoms with a MW of 9082 Da. Monodispersity is confirmed by nuclear magnetic resonance spectroscopy, mass spectrometry, and small-angle X-ray scattering. Moreover, growingmore » different parts proportionately, as nature does, could be a general strategy to achieve defect-free synthesis of macromolecules.« less

Sterically Hindered Chiral Organometallic Complexes: AN X-Ray Crystallographic, NMR Spectroscopic and Ehmo Study.

NASA Astrophysics Data System (ADS)

Malisza, Krisztina Laura

Sterically crowded organometallic complexes present fascinating problems of structure and molecular dynamics. Tetrahedral clusters such as (RCequivCR ^')rm(C_5H_5)_2M _2(CO)_4, where M = Mo or W, crystallize in conformations possessing three terminal carbonyls while the fourth is semi-bridging. However, these ligands undergo a rapid exchange process which can be followed by variable -temperature NMR spectroscopy. When the R substituent is derived from a chiral natural product, the low temperature NMR spectra reveal the presence of diastereomers which are interconvertible via rotations of the organometallic vertices. The fluxional behaviour of tetrahedral clusters containing such vertices as Co(CO)_3, Fe(CO)_3 or rm(C_5H _5)Mo(CO)_2 can be rationalized by means of molecular orbital calculations at the extended Huckel level of approximation. These studies show that the barriers to vertex rotation can usually be traced to one principal orbital interaction in each case. However, in rm(C_5H_5)_2Mo_2(CO) _4(R-CequivC-R) clusters, the barriers are primarily steric in character. The ability of transition metal clusters to delocalize electronic charge is well known and, in principle, could be used to stabilize intermediates of biochemical significance. Treatment of 2-methylcyclopentanone with an alkyne anion was carried out in order to generate 1-alkynyl-2-methylcyclopentanols in which the methyl and alkynyl groups are trans diaxial; the aim was to mimic the "D"-ring of the steroidal contraceptive mestranol. In fact, the major epimer was the one in which the methyl and alkynyl substituents were disposed in a cis manner. The conformation of 2-methyl-1-phenylethynylcyclopentanol 47 was elucidated by two-dimensional NMR techniques. Moreover, the structure of 47 and also of its rm Co _2(CO)_6 derivative have been determined crystallographically. Protonation of the dicobalt or dimolybdenum complexes of 47 lead to stable cations; treatment of these cations with nucleophiles

Influence of ion sterics on diffusiophoresis and electrophoresis in concentrated electrolytes

NASA Astrophysics Data System (ADS)

Stout, Robert F.; Khair, Aditya S.

2017-01-01

We quantify the diffusiophoresis and electrophoresis of a uniformly charged, spherical colloid in a binary electrolyte using modified Poisson-Nernst-Planck equations that account for steric repulsion between finite sized ions. Specifically, we utilize the Bikerman (Bik) lattice gas model and the Carnahan-Starling (CS) and Boublik-Mansoori-Carnahan-Starling-Leland (BMCSL) equations of state for monodisperse and polydisperse, respectively, hard spheres. We compute the phoretic mobility for weak applied fields using an asymptotic approach for thin diffuse layers, where ion steric effects are expected to be most prevalent. The thin diffuse layer limit requires λD/R →0 , where λD is the Debye screening length and R is the particle radius; this limit is readily attained for micron-sized colloids in concentrated electrolytic solutions. It is well known that the classic Poisson-Boltzmann (PB) model for pointlike, noninteracting ions leads to a prediction of a maximum in both the diffusiophoretic and electrophoretic mobilities with increasing particle zeta potential (at fixed λD/R ). In contrast, we find that ion sterics essentially eliminate this maximum (for reasonably attainable zeta potentials) and increase the mobility relative to PB. Next, we consider the more experimentally relevant case of a particle with a constant surface charge density and vary the electrolyte concentration, neglecting charge regulation on surface active sites. Rather surprisingly, there is little difference between the predictions of the four models (PB, Bik, CS, and BMCSL) for electrophoretic mobility in concentrated solutions, at reasonable surface charge densities (˜1 -10 μ C /cm2 ). This is because as the concentration increases, the zeta potential is reduced (to below the thermal voltage for concentrations above about 1 M) and therefore the diffuse layer structure is largely unaffected by ion sterics. For gradients of symmetric electrolytes (equal diffusivities, charge, and size

Overcoming barriers to electronic medical record (EMR) implementation in the US healthcare system: A comparative study.

PubMed

Kumar, Sameer; Aldrich, Krista

2010-12-01

An EMR system implementation would significantly reduce clinician workload and medical errors while saving the US healthcare system major expense. Yet, compared to other developed nations, the US lags behind. This article examines EMR system efforts, benefits, and barriers, as well as steps needed to move the US closer to a nationwide EMR system. The analysis includes a blueprint for implementation of EMR, industry comparisons to highlight the differences between successful and non-successful EMR ventures, references to costs and benefit information, and identification of root causes. 'Poka-yokes' (avoid (yokeru) mistakes (poka)) will be inserted to provide insight into how to systematically overcome challenges. Implementation will require upfront costs including patient privacy that must be addressed early in the development process. Government structure, incentives and mandates are required for nationwide EMR system in the US.

Preparation of chitosan-based multifunctional nanocarriers overcoming multiple barriers for oral delivery of insulin.

PubMed

Li, Lei; Jiang, Guohua; Yu, Weijiang; Liu, Depeng; Chen, Hua; Liu, Yongkun; Tong, Zaizai; Kong, Xiangdong; Yao, Juming

2017-01-01

To overcome multiple barriers for oral delivery of insulin, the chitosan-based multifunctional nanocarriers modified by L-valine (LV, used as a target ligand to facilitate the absorption of the small intestine) and phenylboronic acid (PBA, used as a glucose-responsive unit) have been designed and evaluated in this study. The resultant nanocarriers exhibited low cytotoxicity against HT-29 cells and excellent stability against protein solution. The insulin release behaviors were evaluated triggered by pH and glucose in vitro. The chemical stability of loaded insulin against digestive enzyme were established in presence of simulated gastric fluid (SGF) containing pepsin and simulated intestinal fluid (SIF) containing pancreatin, respectively. The uptake behavior of HT-29 cells was evaluated by confocal laser scanning microscope. After oral administration to the diabetic rats, an effective hypoglycemic effect was obtained compared with subcutaneous injection of insulin. This work suggests that L-valine modified chitosan-based multifunctional nanocarriers may be a promising drug delivery carrier for oral administration of insulin. Copyright © 2016 Elsevier B.V. All rights reserved.

Steric interactions determine side-chain conformations in protein cores.

PubMed

Caballero, D; Virrueta, A; O'Hern, C S; Regan, L

2016-09-01

We investigate the role of steric interactions in defining side-chain conformations in protein cores. Previously, we explored the strengths and limitations of hard-sphere dipeptide models in defining sterically allowed side-chain conformations and recapitulating key features of the side-chain dihedral angle distributions observed in high-resolution protein structures. Here, we show that modeling residues in the context of a particular protein environment, with both intra- and inter-residue steric interactions, is sufficient to specify which of the allowed side-chain conformations is adopted. This model predicts 97% of the side-chain conformations of Leu, Ile, Val, Phe, Tyr, Trp and Thr core residues to within 20°. Although the hard-sphere dipeptide model predicts the observed side-chain dihedral angle distributions for both Thr and Ser, the model including the protein environment predicts side-chain conformations to within 20° for only 60% of core Ser residues. Thus, this approach can identify the amino acids for which hard-sphere interactions alone are sufficient and those for which additional interactions are necessary to accurately predict side-chain conformations in protein cores. We also show that our approach can predict alternate side-chain conformations of core residues, which are supported by the observed electron density. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Overcoming learning barriers through knowledge management.

PubMed

Dror, Itiel E; Makany, Tamas; Kemp, Jonathan

2011-02-01

The ability to learn highly depends on how knowledge is managed. Specifically, different techniques for note-taking utilize different cognitive processes and strategies. In this paper, we compared dyslexic and control participants when using linear and non-linear note-taking. All our participants were professionals working in the banking and financial sector. We examined comprehension, accuracy, mental imagery & complexity, metacognition, and memory. We found that participants with dyslexia, when using a non-linear note-taking technique outperformed the control group using linear note-taking and matched the performance of the control group using non-linear note-taking. These findings emphasize how different knowledge management techniques can avoid some of the barriers to learners. Copyright © 2010 John Wiley & Sons, Ltd.

Atropisomerisation in sterically hindered α,β-disubstituted cyclopentenones derived from an intermolecular cobalt(0)-mediated Pauson-Khand reaction.

PubMed

Moulton, Benjamin E; Lynam, Jason M; Duhme-Klair, Anne-Kathrin; Zheng, Wenxu; Lin, Zhenyang; Fairlamb, Ian J S

2010-12-07

4-(2-Phenylethynyl)-2H-chromen-2-one reacts with norbornene and Co(2)(CO)(8) in an intermolecular Pauson-Khand reaction by focused microwave dielectric heating. Two regioisomeric products are formed; the electron-deficient coumarin moiety preferentially occupies the β-position of the cyclopentenone ring system, whereas the phenyl occupies the α-position. The sterically hindered α,β-(2,3)-disubstituted cyclopentenone regioisomeric products exhibit pronounced atropisomerisation, and the magnitude of the energetic barrier to interconversion between these atropisomers is dependent on the relative position of the coumarin moieties. Interconversion is slow when the coumarin is found in the α-position, whereas interconversion is relatively fast when found in the β-position.

Automation U.S.A.: Overcoming Barriers to Automation.

ERIC Educational Resources Information Center

Brody, Herb

1985-01-01

Although labor unions and inadequate technology play minor roles, the principal barrier to factory automation is "fear of change." Related problems include long-term benefits, nontechnical executives, and uncertainty of factory cost accounting. Industry support for university programs is helping to educate engineers to design, implement, and…

Sterically shielded diboron-containing metallocene olefin polymerization catalysts

DOEpatents

Marks, Tobin J.; Ja, Li; Yang, Xinmin

1995-09-05

A non-coordinating anion, preferably containing a sterically shielded diboron hydride, if combined with a cyclopenta-dienyl-substituted metallocene cation component, such as a zirconocene metallocene, is a useful olefin polymerization catalyst component. The anion preferably has the formula ##STR1## where R is branched lower alkyl, such as t-butyl.

An emancipatory research on CBR and the barriers faced by persons with disabilities.

PubMed

Deepak, Sunil; Kumar, Jayanth; Ramasamy, Parthipan; Griffo, Giampiero

2014-01-01

Abstract Purpose: The aim of this research was to understand the barriers faced by persons with disabilities in their daily lives and the role of CBR projects in overcoming them. A group of persons with disabilities involved in CBR activities was identified and trained in participatory research methodologies. Research was carried out, with support from a scientific advisory group, through sharing of life stories in residential meetings focusing on specific themes. These meetings were attended by 368 persons with disabilities. The barriers identified ranged from isolation, neglect, abuse and violence to lack of access to social, health, education and livelihood opportunities. People faced their first barriers in their own families. Families also played an important role in overcoming some barriers at the individual level. CBR projects assisted people in overcoming barriers mainly by providing information, by facilitating access to existing support and by helping persons in communities to take collective action against the barriers. The research also stimulated DPOs and CBR projects to identify some gaps in tackling the barriers and to start action to overcome them. CBR projects can play a role in overcoming some barriers faced by persons with disabilities. Emancipatory research yields rich data, facilitates ownership and possibly future sustainability. Implications for Rehabilitation Community-based rehabilitation (CBR) programmes can promote mainstreaming and helping in overcoming some barriers faced by persons with disabilities in the communities. CBR programmes can facilitate collective action by persons with disabilities in overcoming barriers to inclusion and participation. Participatory research approaches such as emancipatory research can play a role in understanding disability issues and at the same time, help CBR programmes to identify gaps and strengthen activities.

Teaching English Language Learners: Strategies for Overcoming Barriers

ERIC Educational Resources Information Center

Helfrich, Sara R.; Bosh, Amy J.

2011-01-01

The number of English language learners (ELLs) in today's classrooms is increasing. In this article, the authors identify four perceived barriers beginning and veteran teachers face in teaching literacy to ELLs: the lack of understanding of the role of literacy in other cultures, the teacher's inability to differentiate instruction to meet the…

Overcoming Barriers to Experience Benefits: A Qualitative Analysis of Electronic Health Records and Health Information Exchange Implementation in Local Health Departments

PubMed Central

Williams, Karmen S.; Shah, Gulzar H.; Leider, JP; Gupta, Akarti

2017-01-01

Introduction: Electronic Health Records (EHRs) and Health Information Exchanges (HIEs) are changing surveillance and analytic operations within local health departments (LHDs) across the United States. The objective of this study was to analyze the status, benefits, barriers, and ways of overcoming challenges in the implementation of EHRs and HIEs in LHDs. Methods: This study employed a mixed methods approach, first using the 2013 National Profile of LHDs survey to ascertain the status of EHR and HIE implementation across the US, as well as to aid in selection of respondents for the second, interview-based part of project. Next, forty-nine key-informant interviews of local health department staff were conducted. Data were coded thematically and independently by two researchers. Coding was compared and re-coded using the consensus definitions. Results: Twenty-three percent of LHDs nationwide are using EHRs and 14 percent are using HIEs. The most frequently mentioned benefits for implementation were identified as care coordination, retrieval or managing information, and the ability to track outcomes of care. A few mentioned barriers included financial resources, resistance to change, and IT related issues during implementation. Discussion: Despite financial, technical capacity, and operational constraints, leaders interviewed as part of this project were optimistic about the future of EHRs in local health departments. Recent policy changes and accreditation have implications of improving processes to affect populations served. Conclusions: Overcoming the challenges in implementing EHRs can result in increased efficiencies in surveillance and higher quality patient care and tracking. However, significant opportunity cost does exist. PMID:29881738

Overcoming immunological barriers in regenerative medicine.

PubMed

Zakrzewski, Johannes L; van den Brink, Marcel R M; Hubbell, Jeffrey A

2014-08-01

Regenerative therapies that use allogeneic cells are likely to encounter immunological barriers similar to those that occur with transplantation of solid organs and allogeneic hematopoietic stem cells (HSCs). Decades of experience in clinical transplantation hold valuable lessons for regenerative medicine, offering approaches for developing tolerance-induction treatments relevant to cell therapies. Outside the field of solid-organ and allogeneic HSC transplantation, new strategies are emerging for controlling the immune response, such as methods based on biomaterials or mimicry of antigen-specific peripheral tolerance. Novel biomaterials can alter the behavior of cells in tissue-engineered constructs and can blunt host immune responses to cells and biomaterial scaffolds. Approaches to suppress autoreactive immune cells may also be useful in regenerative medicine. The most innovative solutions will be developed through closer collaboration among stem cell biologists, transplantation immunologists and materials scientists.

Retinal Photoisomerization in Rhodopsin: Electrostatic and Steric Catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomasello, Gaia; Altoe, Piero; Stenta, Marco

2007-12-26

Excited state QM(CASPT2//CASSCF)/MM(GAFF) calculations, by our recently developed code COBRAMM (Computations at Bologna Relating Ab-initio and Molecular Mechanic Methods), were carried out in rhodopsin to investigate on the steric and electrostatic effects in retinal photoisomerization catalysis due to the {beta}-ionone ring and glutammate 181 (GLU 181), respectively. The excited state photoisomerization channel has been mapped and a new christallographyc structure (2.2 Aa resolution) has been used for this purpose. Two different set-ups have been used to evaluate the electrostatic effects of GLU 181 (which is very close to the central double bond of the chromophore): the first with a neutralmore » GLU 181 (as commonly accepted), the second with a negatively charged (i.e. deprotonated) GLU 181 (as very recent experimental findings seem to suggest). On the other hand, {beta}-ionone ring steric effects were evaluated by calculating the photoisomerization path of a modified chromophore, where the ring double bond has been saturated. Spectroscopic properties were calculated and compared with the available experimental data.« less

Overcoming Barriers through the Use of the Familiar

ERIC Educational Resources Information Center

Turner, William James

2015-01-01

There is no such thing as being "English-y" or "maths-y." One person may find English comes more naturally, but being naturally gifted at one subject does not make a person bad at the others. Just because we may find it more challenging to access certain content, this does not mean there is a barrier. William James Turner…

Steric parameters, molecular modeling and hydropathic interaction analysis of the pharmacology of para-substituted methcathinone analogues

PubMed Central

Sakloth, F; Kolanos, R; Mosier, P D; Bonano, J S; Banks, M L; Partilla, J S; Baumann, M H; Negus, S S; Glennon, R A

2015-01-01

Background and Purpose There is growing concern over the abuse of certain psychostimulant methcathinone (MCAT) analogues. This study extends an initial quantitative structure–activity relationship (QSAR) investigation that demonstrated important steric considerations of seven 4- (or para-)substituted analogues of MCAT. Specifically, the steric character (Taft's steric ES) of the 4-position substituent affected in vitro potency to induce monoamine release via dopamine and 5-HT transporters (DAT and SERT) and in vivo modulation of intracranial self-stimulation (ICSS). Here, we have assessed the effects of other steric properties of the 4-position substituents. Experimental Approach Definitive steric parameters that more explicitly focus on the volume, width and length of the MCAT 4-position substituents were assessed. In addition, homology models of human DAT and human SERT based upon the crystallized Drosophila DAT were constructed and docking studies were performed, followed by hydropathic interaction (HINT) analysis of the docking results. Key Results The potency of seven MCAT analogues at DAT was negatively correlated with the volume and maximal width of their 4-position substituents, whereas potency at SERT increased as substituent volume and length increased. SERT/DAT selectivity, as well as abuse-related drug effects in the ICSS procedure, also correlated with the same parameters. Docking solutions offered a means of visualizing these findings. Conclusions and Implications These results suggest that steric aspects of the 4-position substituents of MCAT analogues are key determinants of their action and selectivity, and that the hydrophobic nature of these substituents is involved in their potency at SERT. PMID:25522019

nRGD modified lycobetaine and octreotide combination delivery system to overcome multiple barriers and enhance anti-glioma efficacy.

PubMed

Chen, Tijia; Song, Xu; Gong, Ting; Fu, Yao; Yang, Liuqing; Zhang, Zhirong; Gong, Tao

2017-08-01

For glioma as one of the most common and lethal primary brain tumors, the presence of BBB, BBTB, vasculogenic mimicry (VM) channels and tumor-associated macrophages (TAMs) are key biological barriers. Here, a novel drug delivery system which could efficiently deliver drugs to glioma by overcoming multi-barriers and increase antitumor efficacy through multi-therapeutic mechanisms was well developed. In this study, a multi-target peptide nRGD was used to transport across the BBB, mediate tumor penetration and target TAMs. Lycobetaine (LBT) was adopted to kill glioma cells and octreotide (OCT) was co-delivered to inhibit VM channels and prevent angiogenesis. LBT-OCT liposomes (LPs) showed controlled release profile in vitro, increased uptake efficiency, improved inhibitory effect against glioma cells and VM formation, and enhanced BBB-crossing capability. The median survival time of glioma-bearing mice administered with LBT-OCT LPs-nRGD was significantly longer than LBT-OCT LPs (P<0.01). Besides, nRGD achieved a stronger inhibitory effect against tumor associated macrophages (TAMs) compared to LPs-iRGD treatment groups in vivo. Thus, LPs-nRGD represented a promising versatile delivery platform for combination drug therapy in glioma treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

Principles of nanoparticle design for overcoming biological barriers to drug delivery

PubMed Central

Blanco, Elvin; Shen, Haifa; Ferrari, Mauro

2016-01-01

Biological barriers to drug transport prevent successful accumulation of nanotherapeutics specifically at diseased sites, limiting efficacious responses in disease processes ranging from cancer to inflammation. Although substantial research efforts have aimed to incorporate multiple functionalities and moieties within the overall nanoparticle design, many of these strategies fail to adequately address these barriers. Obstacles, such as nonspecific distribution and inadequate accumulation of therapeutics, remain formidable challenges to drug developers. A reimagining of conventional nanoparticles is needed to successfully negotiate these impediments to drug delivery. Site-specific delivery of therapeutics will remain a distant reality unless nanocarrier design takes into account the majority, if not all, of the biological barriers that a particle encounters upon intravenous administration. By successively addressing each of these barriers, innovative design features can be rationally incorporated that will create a new generation of nanotherapeutics, realizing a paradigmatic shift in nanoparticle-based drug delivery. PMID:26348965

Overcoming the barrier of lactose intolerance to reduce health disparities.

PubMed Central

Jarvis, Judith K.; Miller, Gregory D.

2002-01-01

Federal health goals for the public have focused on reducing health disparities that exist between whites and various racial and ethnic groups. Many of the chronic diseases for which African Americans are at greater risk- hypertension, stroke, colon cancer, and obesity-may be exacerbated by a low intake of calcium and/or other dairy-related nutrients. For example, a low intake of dairy food nutrients, such as calcium, potassium, and magnesium, may contribute to the high risk of hypertension seen in African Americans. The Dietary Approaches to Stop Hypertension (DASH) study demonstrated that a low-fat diet rich in fruits and vegetables (8 to 10 servings) and low-fat dairy foods (3 servings) significantly reduced blood pressure-and was twice as effective in African-American participants. Calcium and dairy food consumption is particularly low among African-American, Hispanic, and Asian populations. Average intakes are near the threshold of 600 to 700 mg/day, below which bone loss and hypertension can result. Although lactose intolerance may be partly to blame for the low calcium intakes due to reduced dairy food consumption by minority populations, culturally determined food preferences and dietary practices learned early in life also play a role. The high incidence figures for primary lactose maldigestion among minority groups grossly overestimates the number who will experience intolerance symptoms after drinking a glass of milk with a meal. Randomized, double-blind, controlled clinical trials have demonstrated that by using a few simple dietary strategies, those who maldigest lactose (have low levels of the lactase enzyme) can easily tolerate a dairy-rich diet that meets calcium intake recommendations. Physicians and other health professionals can help their minority patients and the general public understand how to improve calcium nutrition by overcoming the surmountable barrier of lactose intolerance. At the same time they will be helping to reduce the incidence

Overcoming the barrier of lactose intolerance to reduce health disparities.

PubMed

Jarvis, Judith K; Miller, Gregory D

2002-02-01

Federal health goals for the public have focused on reducing health disparities that exist between whites and various racial and ethnic groups. Many of the chronic diseases for which African Americans are at greater risk- hypertension, stroke, colon cancer, and obesity-may be exacerbated by a low intake of calcium and/or other dairy-related nutrients. For example, a low intake of dairy food nutrients, such as calcium, potassium, and magnesium, may contribute to the high risk of hypertension seen in African Americans. The Dietary Approaches to Stop Hypertension (DASH) study demonstrated that a low-fat diet rich in fruits and vegetables (8 to 10 servings) and low-fat dairy foods (3 servings) significantly reduced blood pressure-and was twice as effective in African-American participants. Calcium and dairy food consumption is particularly low among African-American, Hispanic, and Asian populations. Average intakes are near the threshold of 600 to 700 mg/day, below which bone loss and hypertension can result. Although lactose intolerance may be partly to blame for the low calcium intakes due to reduced dairy food consumption by minority populations, culturally determined food preferences and dietary practices learned early in life also play a role. The high incidence figures for primary lactose maldigestion among minority groups grossly overestimates the number who will experience intolerance symptoms after drinking a glass of milk with a meal. Randomized, double-blind, controlled clinical trials have demonstrated that by using a few simple dietary strategies, those who maldigest lactose (have low levels of the lactase enzyme) can easily tolerate a dairy-rich diet that meets calcium intake recommendations. Physicians and other health professionals can help their minority patients and the general public understand how to improve calcium nutrition by overcoming the surmountable barrier of lactose intolerance. At the same time they will be helping to reduce the incidence

Parameterization of phosphine ligands demonstrates enhancement of nickel catalysis via remote steric effects.

PubMed

Wu, Kevin; Doyle, Abigail G

2017-08-01

The field of Ni-catalysed cross-coupling has seen rapid recent growth because of the low cost of Ni, its earth abundance, and its ability to promote unique cross-coupling reactions. Whereas advances in the related field of Pd-catalysed cross-coupling have been driven by ligand design, the development of ligands specifically for Ni has received minimal attention. Here, we disclose a class of phosphines that enable the Ni-catalysed Csp 3 Suzuki coupling of acetals with boronic acids to generate benzylic ethers, a reaction that failed with known ligands for Ni and designer phosphines for Pd. Using parameters to quantify phosphine steric and electronic properties together with regression statistical analysis, we identify a model for ligand success. The study suggests that effective phosphines feature remote steric hindrance, a concept that could guide future ligand design tailored to Ni. Our analysis also reveals that two classic descriptors for ligand steric environment-cone angle and % buried volume-are not equivalent, despite their treatment in the literature.

Parameterization of phosphine ligands demonstrates enhancement of nickel catalysis via remote steric effects

NASA Astrophysics Data System (ADS)

Wu, Kevin; Doyle, Abigail G.

2017-08-01

The field of Ni-catalysed cross-coupling has seen rapid recent growth because of the low cost of Ni, its earth abundance, and its ability to promote unique cross-coupling reactions. Whereas advances in the related field of Pd-catalysed cross-coupling have been driven by ligand design, the development of ligands specifically for Ni has received minimal attention. Here, we disclose a class of phosphines that enable the Ni-catalysed Csp3 Suzuki coupling of acetals with boronic acids to generate benzylic ethers, a reaction that failed with known ligands for Ni and designer phosphines for Pd. Using parameters to quantify phosphine steric and electronic properties together with regression statistical analysis, we identify a model for ligand success. The study suggests that effective phosphines feature remote steric hindrance, a concept that could guide future ligand design tailored to Ni. Our analysis also reveals that two classic descriptors for ligand steric environment—cone angle and % buried volume—are not equivalent, despite their treatment in the literature.

Roadblocks in the gut: barriers to enteric infection.

PubMed

Gill, Navkiran; Wlodarska, Marta; Finlay, B Brett

2011-05-01

This review discusses the barriers an enteric pathogen encounters when establishing an infection in the intestinal tract. There are potential barriers in the lumen that increase competition for nutrients and space. The role of mucus layer, and the antimicrobial peptides and secretory IgA sequestered within it, are also significant barriers. After overcoming these defences, the pathogen encounters the epithelial layer. This layer can be broken down into various protective components including enterocytes, Paneth cells, goblet cells, M cells and pathogen recognition receptors. Collectively, these intestinal defences constitute significant barriers that pathogens must overcome to successfully colonize this important mucosal surface. © 2011 Blackwell Publishing Ltd.

Steric sea level change in the Bay of Bengal: investigating the most variable component of sea level change

NASA Astrophysics Data System (ADS)

Uebbing, Bernd; Kusche, Jürgen; Rietbroek, Roelof; Shum, Ck

2015-04-01

Regional sea level change is influenced by contributions from mass sources, like melting of glaciers and the ice-sheets in Greenland and Antarctica, as well as steric contributions from changes in temperature and salinity of the oceans. Radar altimetry indicates a sea level trend in the Bay of Bengal of about 6 mm- yr over the time period of 2002-2014, which is significantly larger than the global mean trend. Here, we explain 80% of this rise by steric contributions and 20% by mass-related contributions. The increased rise of sea level in the Bay of Bengal threatens the coastal vulnerability of the surrounding countries like Bangladesh, where this effect is exacerbated in combination with land subsidence of the very low lying coastal areas. The BanD-AID (Bangladesh Delta: Assessment of the Causes of Sea-level Rise Hazards and Integrated Development of Predictive Modeling Towards Mitigation and Adaptation) project tries to assess the current and future sea level rise and its impacts on the people living in the threatened coastal areas. As a part of this, it is necessary to analyze the different mass and steric contributors to the total sea level rise to aid in the prediction of future risks. We use data from radar altimetry and the GRACE mission to separate the total sea level rise into contributions from mass sources and steric changes. In our approach, temporal GRACE gravity data and Jason-1 and -2 along track altimetry data are fitted to time invariant spatial patterns (fingerprints) to avoid problems with GRACE resolution, filtering, geocenter and related issues. Our results show that in the Bay of Bengal the steric component is influenced by annual and interannual phenomena and, at the same time, it is significantly larger compared to the individual mass contributions, which show a linear and relatively stable behavior over time. We validate the steric component of our inversion by comparing it to independent steric estimates from 4-D gridded temperature and

Desensitization: Overcoming the Immunologic Barriers to Transplantation

PubMed Central

Choi, Jua; Vo, Ashley; Peng, Alice; Jordan, Stanley C.

2017-01-01

HLA (Human Leucocyte Antigen) sensitization is a significant barrier to successful kidney transplantation. It often translates into difficult crossmatch before transplant and increased risk of acute and chronic antibody mediated rejection after transplant. Over the last decade, several immunomodulatory therapies have emerged allowing for increased access to kidney transplantation for the immunologically disadvantaged group of HLA sensitized end stage kidney disease patients. These include IgG inactivating agents, anti-cytokine antibodies, costimulatory molecule blockers, complement inhibitors, and agents targeting plasma cells. In this review, we discuss currently available agents for desensitization and provide a brief analysis of data on novel biologics, which will likely improve desensitization outcomes, and have potential implications in treatment of antibody mediated rejection. PMID:28127571

Demonstration of an algorithm to overcome health system-related barriers to timely diagnosis of breast diseases in rural Zambia

PubMed Central

Nzayisenga, Jean-Baptiste; Shibemba, Aaron; Kusweje, Victor; Chiboola, Hector; Amuyunzu-Nyamongo, Mary; Kapambwe, Sharon; Mwaba, Catherine; Lermontov, Pavlo; Mumba, Chibamba; Henry-Tillman, Ronda; Parham, Groesbeck P.

2018-01-01

Background Long delays to diagnosis is a major cause of late presentation of breast diseases in sub-Saharan Africa. Aims We designed and implemented a single-visit breast care algorithm that overcomes health system-related barriers to timely diagnosis of breast diseases. Methods A multidisciplinary team of Zambian healthcare experts trained a team of mid- and high-level Zambian healthcare practitioners how to evaluate women for breast diseases, and train trainers to do likewise. Working collaboratively, the two teams then designed a clinical platform that provides multiple breast care services within a single visit. The service platform was implemented using a breast outreach camp format, during which breast self-awareness, psychosocial counseling, clinical breast examination, breast ultrasound, ultrasound-guided biopsy, imprint cytology of biopsy specimens and surgical treatment or referral, were offered within a single visit. Results Eleven hundred and twenty-nine (1129) women attended the camps for breast care. Mean age was 35.9 years. The majority were multiparous (79.4%), breast-fed (76.0%), and reported hormone use (50.4%). Abnormalities were detected on clinical breast examination in 122 (10.8%) women, 114 of whom required ultrasound. Of the 114 who underwent ultrasound, 48 had identifiable lesions and were evaluated with ultrasound-guided core needle biopsy (39) or fine-needle aspiration (9). The concordance between imprint cytology and histopathology was 100%, when breast specimens were classified as either benign or malignant. However, when specimens were classified by histopathologic subtype, the concordance between imprint cytology and histology was 85.7% for benign and 100% for malignant lesions. Six (6) women were diagnosed with invasive cancer. Eighteen (18) women with symptomatic breast lesions had next-day surgery. Significance Similar to its impact on cervical cancer prevention services, a single visit breast care algorithm has the potential to

The GEOFAR Project - Geothermal Finance and Awareness in Europeans Regions - Development of new schemes to overcome non-technical barriers, focusing particularly on financial barriers

NASA Astrophysics Data System (ADS)

Poux, Adeline; Wendel, Marco; Jaudin, Florence; Hiegl, Mathias

2010-05-01

Numerous advantages of geothermal energy like its widespread distribution, a base-load power and availability higher than 90%, a small footprint and low carbon emissions, and the growing concerns about climate changes strongly promote the development of geothermal projects. Geothermal energy as a local energy source implies needs on surface to be located close to the geothermal resource. Many European regions dispose of a good geothermal potential but it is mostly not sufficiently developed due to non-technical barriers occurring at the very early stages of the project. The GEOFAR Project carried out within the framework of EU's "Intelligent Energy Europe" (IEE) program, gathers a consortium of European partners from Germany, France, Greece, Spain and Portugal. Launched in September 2008, the aim of this research project is to analyze the mentioned non-technical barriers, focusing most particularly on economic and financial aspects. Based on this analysis GEOFAR aims at developing new financial and administrative schemes to overcome the main financial barriers for deep geothermal projects (for electricity and direct use, without heat pumps). The analysis of the current situation and the future development of geothermal energy in GEOFAR target countries (Germany, France, Greece, Spain, Portugal, Slovakia, Bulgaria and Hungary) was necessary to understand and expose the diverging status of the geothermal sector and the more and less complicated situation for geothermal projects in different Europeans Regions. A deeper analysis of 40 cases studies (operating, planned and failed projects) of deep geothermal projects also contributed to this detailed view. An exhaustive analysis and description of financial mechanisms already existing in different European countries and at European level to support investors completed the research on non-technical barriers. Based on this profound analysis, the GEOFAR project has made an overview of the difficulties met by project

Overcoming the ten most common barriers to effective team communication.

PubMed

Hills, Laura

2013-01-01

Communication is at the heart of medical practice management. Yet there are many barriers to effective communication that can interfere with the smooth running of the practice. This article describes the 10 most common barriers to effective medical practice team communication and offers six steps the practice manager can take to break them down. This article also suggests that the practice develop a team communication strategy. It suggests 10 communication principles readers can share directly with their teams and describes three hallmarks of effective team communication. Finally, this article provides a list of 25 practical questions practice managers can use to improve their team's communication.

Deterministic folding: The role of entropic forces and steric specificities

NASA Astrophysics Data System (ADS)

da Silva, Roosevelt A.; da Silva, M. A. A.; Caliri, A.

2001-03-01

The inverse folding problem of proteinlike macromolecules is studied by using a lattice Monte Carlo (MC) model in which steric specificities (nearest-neighbors constraints) are included and the hydrophobic effect is treated explicitly by considering interactions between the chain and solvent molecules. Chemical attributes and steric peculiarities of the residues are encoded in a 10-letter alphabet and a correspondent "syntax" is provided in order to write suitable sequences for the specified target structures; twenty-four target configurations, chosen in order to cover all possible values of the average contact order χ (0.2381⩽χ⩽0.4947 for this system), were encoded and analyzed. The results, obtained by MC simulations, are strongly influenced by geometrical properties of the native configuration, namely χ and the relative number φ of crankshafts-type structures: For χ<0.35 the folding is deterministic, that is, the syntax is able to encode successful sequences: The system presents larger encodability, minimum sequence-target degeneracies and smaller characteristic folding time τf. For χ⩾0.35 the above results are not reproduced any more: The folding success is severely reduced, showing strong correlation with φ. Additionally, the existence of distinct characteristic folding times suggests that different mechanisms are acting at the same time in the folding process. The results (all obtained from the same single model, under the same "physiological conditions") resemble some general features of the folding problem, supporting the premise that the steric specificities, in association with the entropic forces (hydrophobic effect), are basic ingredients in the protein folding process.

Overcoming Barriers to Eye Care: Patient Response to a Medical Social Worker in a Glaucoma Service.

PubMed

Fudemberg, Scott J; Amarasekera, Dilru C; Silverstein, Marlee H; Linder, Kathryn M; Heffner, Paul; Hark, Lisa A; Waisbourd, Michael

2016-08-01

This paper investigates the patient response to a medical social worker in a glaucoma clinic. The literature suggests that medical social workers are effective in a variety of health care settings, yet the efficacy of a medical social worker in an adult ophthalmic setting has not been studied. We present the results of a retrospective chart review of 50 patients with glaucoma referred to a medical social worker between January 5, 2015 and June 31, 2015 in an outpatient clinic of an urban eye hospital. Clinical and demographic data, as well as the data from a quality of care questionnaire, were collected for each patient. Patients rated their interaction with the medical social worker as highly positive (mean = 4.75, 5-point Likert scale), and nearly 90 % of patients expressed interest in future contact with the social worker. Additionally, most patients reported that the social worker resolved the issues they were facing (61.1 %), supported them in seeing their ophthalmologist (70.6 %), and helped them to manage their glaucoma (69.7 %). Reported barriers to glaucoma care were emotional distress; cost of office visits and medications; lack of medical insurance; transportation; poor medication adherence; impairment of daily activities; follow-up adherence; and language. As vision loss from glaucoma is irreversible, it is important to detect and treat patients at early stages of the disease. Therefore, it is imperative for patients to regularly visit their eye care providers and adhere to treatment and follow-up recommendations. This study suggests that a medical social worker could play a pivotal role in helping patients with glaucoma overcome barriers to treatment and facilitate disease management.

Mass-induced sea level variations in the Red Sea from steric-corrected altimetry, GRACE, in-situ bottom pressure records, and hydrographic observations

NASA Astrophysics Data System (ADS)

Feng, Wei; Lemoine, Jean-Michel; Zhong, Min; Xu, Houze

2014-05-01

An annual amplitude of ~18 cm mass-induced sea level variations (SLV) in the Red Sea is detected from steric-corrected altimetry and the Gravity Recovery and Climate Experiment (GRACE) satellites from 2003 to 2011, which dominates the mean sea level in the region. Seawater mass variations here generally reach maximum in late January/early February. The steric component of SLV calculated from oceanographic temperature and salinity data is relatively small and peaks about seven months later than mass variations. The phase difference between the steric SLV and the mass-induced SLV indicates that when the Red Sea gains the mass from inflow water in winter, the steric SLV fall, and vice versa in summer. In-situ bottom pressure records in the eastern coast of the Red Sea validate the high mass variability observed by steric-corrected altimetry and GRACE. Furthermore, we compare the horizontal water mass flux in the Red Sea from steric-corrected altimetry and GRACE with that estimated from hydrographic observations.

The BARRIERS scale -- the barriers to research utilization scale: A systematic review

PubMed Central

2010-01-01

Background A commonly recommended strategy for increasing research use in clinical practice is to identify barriers to change and then tailor interventions to overcome the identified barriers. In nursing, the BARRIERS scale has been used extensively to identify barriers to research utilization. Aim and objectives The aim of this systematic review was to examine the state of knowledge resulting from use of the BARRIERS scale and to make recommendations about future use of the scale. The following objectives were addressed: To examine how the scale has been modified, to examine its psychometric properties, to determine the main barriers (and whether they varied over time and geographic locations), and to identify associations between nurses' reported barriers and reported research use. Methods Medline (1991 to September 2009) and CINHAL (1991 to September 2009) were searched for published research, and ProQuest® digital dissertations were searched for unpublished dissertations using the BARRIERS scale. Inclusion criteria were: studies using the BARRIERS scale in its entirety and where the sample was nurses. Two authors independently assessed the study quality and extracted the data. Descriptive and inferential statistics were used. Results Sixty-three studies were included, with most using a cross-sectional design. Not one study used the scale for tailoring interventions to overcome identified barriers. The main barriers reported were related to the setting, and the presentation of research findings. Overall, identified barriers were consistent over time and across geographic locations, despite varying sample size, response rate, study setting, and assessment of study quality. Few studies reported associations between reported research use and perceptions of barriers to research utilization. Conclusions The BARRIERS scale is a nonspecific tool for identifying general barriers to research utilization. The scale is reliable as reflected in assessments of internal

Activation barriers for methylation of DNA bases by dimethyl sulfate

NASA Astrophysics Data System (ADS)

Eichler, Daniel R.; Papadantonakis, George A.

2017-12-01

The SN2 transition states of the methylation reaction of DNA bases with dimethyl sulfate were examined employing DFT/ M06-2X/6-31+G∗ and DFT/B3LYP-D3/6-311+G (2df, 2p) levels of theory. Solvation effects were examined using the conductor-like polarizable continuum model (CPCM). Calculation results and feedback from electrostatic potential maps show that in water, charge separation lowers the activation barriers relative to the gas phase for the reactions at N7 of guanine, N3 of adenine and cytosine. Also, the reaction at the O6 site of guanine is governed by steric interference and exhibits a higher activation barrier in water.

Effect of sterically demanding substituents on the conformational stability of the collagen triple helix.

PubMed

Erdmann, Roman S; Wennemers, Helma

2012-10-17

The effect of sterically demanding groups at proline residues on the conformational stability of the collagen triple helix was examined. The thermal stabilities (T(m) and ΔG) of eight different triple helices derived from collagen model peptides with (4R)- or (4S)-configured amidoprolines bearing either methyl or bulkier tert-butyl groups in the Xaa or Yaa position were determined and served as a relative measure for the conformational stability of the corresponding collagen triple helices. The results show that sterically demanding substituents are tolerated in the collagen triple helix when they are attached to (4R)-configured amidoprolines in the Xaa position or to (4S)-configured amidoprolines in the Yaa position. Structural studies in which the preferred conformation of (4R)- or (4S)-configured amidoproline were overlaid with the Pro and Hyp residues within a crystal structure of collagen revealed that the sterically demanding groups point to the outside of these two triple helices and thereby do not interfere with the formation of the triple helix. In all of the other examined collagen derivatives with lower stability of the triple helices, the acetyl or pivaloyl residues point toward the inside of the triple helix and clash with a residue of the neighboring strand. The results also revealed that unfavorable steric dispositions affect the conformational stability of the collagen triple helix more than unfavorable ring puckers of the proline residues. The results are useful for the design of functionalized collagen based materials.

Overcoming the barriers to implementing patient-focused care.

PubMed

McQueen, J

1993-01-01

Potential barriers to implementing PFC sometimes seem enormous. Instead of orienting toward problems associated with implementing PFC, we can eliminate some of the barriers simply by focusing on and pursuing the ideal, "the seamless patient care experience." Fundamentally improving our health care delivery systems is not really a strategic option. It is our responsibility. We must do things better, faster, with more compassion, and at less cost. What evidence will demonstrate that your organization is becoming more patient-focused? Patients will not be inconvenienced because of "how the system works." They will consider your organization "best in class." They will know that the hospital's medical care and services will meet or exceed their expectations. Physicians and staff will feel more highly valued by the organization. Management empowers them by improving the systems they must use, providing ongoing training, and decentralizing the authority they need to deliver excellent medical care and satisfy patients' personal needs. Communication improves vertically and horizontally throughout the organization. The hospital becomes increasingly attractive to employers and HMOs. Reengineered processes result in increases in productivity. Better patient outcomes, at less cost, can be demonstrated. Occupancy rates stabilize or grow, utilization is carefully managed, and improvements in the bottom line strengthen the organization. How do we make these visions a reality? By committing to PFC and getting started right away. Just as "quality" is multidimensional, so must be our operating strategy. Patient-focused care is the model that will redefine the future of health care.

Cell-to-Cell Transmission Can Overcome Multiple Donor and Target Cell Barriers Imposed on Cell-Free HIV

PubMed Central

Ilinskaya, Anna; Dorjbal, Batsukh; Truong, Rosaline; Derse, David; Uchil, Pradeep D.; Heidecker, Gisela; Mothes, Walther

2013-01-01

Virus transmission can occur either by a cell-free mode through the extracellular space or by cell-to-cell transmission involving direct cell-to-cell contact. The factors that determine whether a virus spreads by either pathway are poorly understood. Here, we assessed the relative contribution of cell-free and cell-to-cell transmission to the spreading of the human immunodeficiency virus (HIV). We demonstrate that HIV can spread by a cell-free pathway if all the steps of the viral replication cycle are efficiently supported in highly permissive cells. However, when the cell-free path was systematically hindered at various steps, HIV transmission became contact-dependent. Cell-to-cell transmission overcame barriers introduced in the donor cell at the level of gene expression and surface retention by the restriction factor tetherin. Moreover, neutralizing antibodies that efficiently inhibit cell-free HIV were less effective against cell-to-cell transmitted virus. HIV cell-to-cell transmission also efficiently infected target T cells that were relatively poorly susceptible to cell-free HIV. Importantly, we demonstrate that the donor and target cell types influence critically the extent by which cell-to-cell transmission can overcome each barrier. Mechanistically, cell-to-cell transmission promoted HIV spread to more cells and infected target cells with a higher proviral content than observed for cell-free virus. Our data demonstrate that the frequently observed contact-dependent spread of HIV is the result of specific features in donor and target cell types, thus offering an explanation for conflicting reports on the extent of cell-to-cell transmission of HIV. PMID:23308151

Steric Effect on the Nucleophilic Reactivity of Nickel(III) Peroxo Complexes.

PubMed

Kim, Jalee; Shin, Bongki; Kim, Hyunjeong; Lee, Junhyung; Kang, Joongoo; Yanagisawa, Sachiko; Ogura, Takashi; Masuda, Hideki; Ozawa, Tomohiro; Cho, Jaeheung

2015-07-06

A set of nickel(III) peroxo complexes bearing tetraazamacrocyclic ligands, [Ni(III)(TBDAP)(O2)](+) (TBDAP = N,N'-di-tert-butyl-2,11-diaza[3.3](2,6)pyridinophane) and [Ni(III)(CHDAP)(O2)](+) (CHDAP = N,N'-dicyclohexyl-2,11-diaza[3.3](2,6)pyridinophane), were prepared by reacting [Ni(II)(TBDAP)(NO3)(H2O)](+) and [Ni(II)(CHDAP)(NO3)](+), respectively, with H2O2 in the presence of triethylamine. The mononuclear nickel(III) peroxo complexes were fully characterized by various physicochemical methods, such as UV-vis, electrospray ionization mass spectrometry, resonance Raman, electron paramagnetic resonance, and X-ray analysis. The spectroscopic and structural characterization clearly shows that the NiO2 cores are almost identical where the peroxo ligand is bound in a side-on fashion. However, the different steric properties of the supporting ligands were confirmed by X-ray crystallography, where the CHDAP ligand gives enough space around the Ni core compared to the TBDAP ligand. The nickel(III) peroxo complexes showed reactivity in the oxidation of aldehydes. In the aldehyde deformylation reaction, the nucleophilic reactivity of the nickel(III) peroxo complexes was highly dependent on the steric properties of the macrocyclic ligands, with a reactivity order of [Ni(III)(TBDAP)(O2)](+) < [Ni(III)(CHDAP)(O2)](+). This result provides fundamental insight into the mechanism of the structure (steric)-reactivity relationship of metal peroxo intermediates.

Study on steric transition in asymmetrical flow field-flow fractionation and application to characterization of high-energy material.

PubMed

Dou, Haiyang; Lee, Yong-Ju; Jung, Euo Chang; Lee, Byung-Chul; Lee, Seungho

2013-08-23

In field-flow fractionation (FFF), there is the 'steric transition' phenomenon where the sample elution mode changes from the normal to steric/hyperlayer mode. Accurate analysis by FFF requires understanding of the steric transition phenomenon, particularly when the sample has a broad size distribution, for which the effect by combination of different modes may become complicated to interpret. In this study, the steric transition phenomenon in asymmetrical flow FFF (AF4) was studied using polystyrene (PS) latex beads. The retention ratio (R) gradually decreases as the particle size increases (normal mode) and reaches a minimum (Ri) at diameter around 0.5μm, after which R increases with increasing diameter (steric/hyperlayer mode). It was found that the size-based selectivity (Sd) tends to increase as the channel thickness (w) increases. The retention behavior of cyclo-1,3,5-trimethylene-2,4,6-trinitramine (commonly called 'research department explosive' (RDX)) particles in AF4 was investigated by varying experimental parameters including w and flow rates. AF4 showed a good reproducibility in size determination of RDX particles with the relative standard deviation of 4.1%. The reliability of separation obtained by AF4 was evaluated by transmission electron microscopy (TEM). Copyright © 2013 Elsevier B.V. All rights reserved.

Community based saving groups: an innovative approach to overcome the financial and social barriers in health care seeking by the women in the rural remote communities of Pakistan.

PubMed

Shaikh, Babar Tasneem; Noorani, Qayyum; Abbas, Shazia

2017-01-01

In remote rural areas of Pakistan, access to the maternal, newborn and child health (MNCH) care provided by a skilled health provider is quite difficult. There are many reasons such as women's restricted social mobility, lack of education, disenfranchised in decision making and poverty. To overcome these barriers and impediments in district Chitral, which is the largest territory in terms of geography in province Khyber Pakhtunkhwa, local women of reproductive age, were mobilized to form the Community Based Saving Groups (CBSGs) at the village level. In these CBSGs, they pool-in their money, and then provide soft loans to the expecting mothers to meet the expenses of delivery. Simultaneously, young literate women were identified from the local communities; they were trained as Community Midwives (CMWs), using national MNCH curriculum, and later deployed in their respective villages within the district. This study captured their perceptions about the formation of CBSGs to overcome the financial and social barriers, and subsequent use of CMW services. A qualitative enquiry was conducted with the delivered mothers and their husbands through gender specific separate focus group discussions, with CBSG members and with non-members in four different sites of District Chitral. CBSG member women were far more aware on health issues. Information sought from these forums brought a noticeable change in the health seeking practices. Seeking care from a trained birth attendant in the community became easier. Women associated with the CBSGs as members, expressed an increased access to money for utilizing the CMW services, better awareness on MNCH issues, and empowerment to decide for seeking care. CBSG have been an instrumental platform for social networking, helping each other in other household matters. Women have started using the services of CMW and the CBSGs have actually helped them overcome the financial barriers in health care seeking. Moreover, the CBSGs became a medium

Three-Dimensional Mapping of Microenvironmental Control of Methyl Rotational Barriers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hembree, William I; Baudry, Jerome Y

2011-01-01

Sterical (van der Waals-induced) rotational barriers of methyl groups are investigated theoretically, using ab initio and empirical force field calculations, for various three-dimensional microenvironmental conditions around the methyl group rotator of a model neopentane molecule. The destabilization (reducing methyl rotational barriers) or stabilization (increasing methyl rotational barriers) of the staggered conformation of the methyl rotator depends on a combination of microenvironmental contributions from (i) the number of atoms around the rotator, (ii) the distance between the rotator and the microenvironmental atoms, and (iii) the dihedral angle between the stator, rotator, and molecular environment around the rotator. These geometrical criteria combinemore » their respective effects in a linearly additive fashion, with no apparent cooperative effects, and their combination in space around a rotator may increase, decrease, or leave the rotator s rotational barrier unmodified. This is exemplified in a geometrical analysis of the alanine dipeptide crystal where microenvironmental effects on methyl rotators barrier of rotation fit the geometrical mapping described in the neopentane model.« less

Metal-Free Approaches to Sterically-Hindered Bonds

NASA Astrophysics Data System (ADS)

Dunham, Veronica Vin-yi

Developing methods to perform cross coupling reactions by means of catalysis is highly desirable in chemistry. Many industries in today's society, such as the petroleum, agriculture, pharmaceutical, electronics, and polymer industry, use catalysis to some extent whether it is to make molecules that offer crop protection or toward the synthesis of the active ingredient of a medication. It is noteworthy that over 90% of chemicals are made through catalytic processes and that the catalyst market reached $17 billion in 2014, which demonstrates the demand for such methods. While transition metal catalysts have advantages such as low catalyst loading, broad reactivity, and that they have been well studied, some disadvantages are that they can be relatively expensive and sometimes air sensitive which can make them challenging to use. Organocatalysis, specifically noncovalent catalysis operating through hydrogen bond donating interactions, offers an environmentally-friendly alternative to transition metal catalysis. Our lab utilizes organocatalysis as a strategy to synthesize challenging, sterically-hindered bonds. Nitrimines have been identified as powerful coupling partners for the sustainable construction of new sterically congested carbon-carbon and carbon-heteroatom bonds. Using urea catalysis, a metal-free method to synthesize previously inaccessible enamines has been developed. Conventional routes to synthesize enamines as important building blocks toward target molecules generally require Lewis/Bronsted acids or expensive transition metals; however, these methods are often unsuccessful when stericallyhindered substrates are used. To address this synthetic challenge, it was hypothesized that hydrogen bonding interactions between a urea organocatalyst and nitrimine would generate a reactive species suited for the effective carbon-nitrogen coupling with amines to give the desired enamine products. This reaction provides high yields (up to 99%) of enamines using a

Nested barriers to low-carbon infrastructure investment

NASA Astrophysics Data System (ADS)

Granoff, Ilmi; Hogarth, J. Ryan; Miller, Alan

2016-12-01

Low-carbon, 'green' economic growth is necessary to simultaneously improve human welfare and avoid the worst impacts of climate change and environmental degradation. Infrastructure choices underpin both the growth and the carbon intensity of the economy. This Perspective explores the barriers to investing in low-carbon infrastructure and some of the policy levers available to overcome them. The barriers to decarbonizing infrastructure 'nest' within a set of barriers to infrastructure development more generally that cause spending on infrastructure--low-carbon or not--to fall more than 70% short of optimal levels. Developing countries face additional barriers such as currency and political risks that increase the investment gap. Low-carbon alternatives face further barriers, such as commercialization risk and financial and public institutions designed for different investment needs. While the broader barriers to infrastructure investment are discussed in other streams of literature, they are often disregarded in literature on renewable energy diffusion or climate finance, which tends to focus narrowly on the project costs of low- versus high-carbon options. We discuss how to overcome the barriers specific to low-carbon infrastructure within the context of the broader infrastructure gap.

Self-Assembled Peptide-Lanthanide Nanoclusters for Safe Tumor Therapy: Overcoming and Utilizing Biological Barriers to Peptide Drug Delivery.

PubMed

Yan, Jin; He, Wangxiao; Yan, Siqi; Niu, Fan; Liu, Tianya; Ma, Bohan; Shao, Yongping; Yan, Yuwei; Yang, Guang; Lu, Wuyuan; Du, Yaping; Lei, Bo; Ma, Peter X

2018-02-27

Developing a sophisticated nanomedicine platform to deliver therapeutics effectively and safely into tumor/cancer cells remains challenging in the field of nanomedicine. In particular, reliable peptide drug delivery systems capable of overcoming biological barriers are still lacking. Here, we developed a simple, rapid, and robust strategy to manufacture nanoclusters of ∼90 nm in diameter that are self-assembled from lanthanide-doped nanoparticles (5 nm), two anticancer peptides with different targets (BIM and PMI), and one cyclic peptide iNGR targeted to cancer cells. The peptide-lanthanide nanoclusters (LDC-PMI-BIM-iNGR) enhanced the resistance of peptide drugs to proteolysis, disassembled in response to reductive conditions that are present in the tumor microenvironment and inhibited cancer cell growth in vitro and in vivo. Notably, LDC-PMI-BIM-iNGR exhibited extremely low systemic toxicity and side effects in vivo. Thus, the peptide-lanthanide nanocluster may serve as an ideal multifunctional platform for safe, targeted, and efficient peptide drug delivery in cancer therapy.

Overcoming endosomal barrier by amphotericin B-loaded dual pH-responsive PDMA-b-PDPA micelleplexes for siRNA delivery.

PubMed

Yu, Haijun; Zou, Yonglong; Wang, Yiguang; Huang, Xiaonan; Huang, Gang; Sumer, Baran D; Boothman, David A; Gao, Jinming

2011-11-22

The endosomal barrier is a major bottleneck for the effective intracellular delivery of siRNA by nonviral nanocarriers. Here, we report a novel amphotericin B (AmB)-loaded, dual pH-responsive micelleplex platform for siRNA delivery. Micelles were self-assembled from poly(2-(dimethylamino)ethyl methacrylate)-block-poly(2-(diisopropylamino)ethyl methacrylate) (PDMA-b-PDPA) diblock copolymers. At pH 7.4, AmB was loaded into the hydrophobic PDPA core, and siRNA was complexed with a positively charged PDMA shell to form the micelleplexes. After cellular uptake, the PDMA-b-PDPA/siRNA micelleplexes dissociated in early endosomes to release AmB. Live cell imaging studies demonstrated that released AmB significantly increased the ability of siRNA to overcome the endosomal barrier. Transfection studies showed that AmB-loaded micelleplexes resulted in significant increase in luciferase (Luc) knockdown efficiency over the AmB-free control. The enhanced Luc knockdown efficiency was abolished by bafilomycin A1, a vacuolar ATPase inhibitor that inhibits the acidification of the endocytic organelles. These data support the central hypothesis that membrane poration by AmB and increased endosomal swelling and membrane tension by a "proton sponge" polymer provided a synergistic strategy to disrupt endosomes for improved intracellular delivery of siRNA. © 2011 American Chemical Society

Chromosome doubling to overcome the chrysanthemum cross barrier based on insight from transcriptomic and proteomic analyses.

PubMed

Zhang, Fengjiao; Hua, Lichun; Fei, Jiangsong; Wang, Fan; Liao, Yuan; Fang, Weimin; Chen, Fadi; Teng, Nianjun

2016-08-09

Cross breeding is the most commonly used method in chrysanthemum (Chrysanthemum morifolium) breeding; however, cross barriers always exist in these combinations. Many studies have shown that paternal chromosome doubling can often overcome hybridization barriers during cross breeding, although the underlying mechanism has seldom been investigated. In this study, we performed two crosses: C. morifolium (pollen receptor) × diploid C. nankingense (pollen donor) and C. morifolium × tetraploid C. nankingense. Seeds were obtained only from the latter cross. RNA-Seq and isobaric tags for relative and absolute quantitation (iTRAQ) were used to investigate differentially expressed genes and proteins during key embryo development stages in the latter cross. A previously performed cross, C. morifolium × diploid C. nankingense, was compared to our results and revealed that transcription factors (i.e., the agamous-like MADS-box protein AGL80 and the leucine-rich repeat receptor protein kinase EXS), hormone-responsive genes (auxin-binding protein 1), genes and proteins related to metabolism (ATP-citrate synthase, citrate synthase and malate dehydrogenase) and other genes reported to contribute to embryo development (i.e., LEA, elongation factor and tubulin) had higher expression levels in the C. morifolium × tetraploid C. nankingense cross. In contrast, genes related to senescence and cell death were down-regulated in the C. morifolium × tetraploid C. nankingense cross. The data resources helped elucidate the gene and protein expression profiles and identify functional genes during different development stages. When the chromosomes from the male parent are doubled, the genes contributing to normal embryo developmentare more abundant. However, genes with negative functions were suppressed, suggesting that chromosome doubling may epigenetically inhibit the expression of these genes and allow the embryo to develop normally.

Overcoming barriers to public understanding of climate change

NASA Astrophysics Data System (ADS)

Hayhoe, K.

2012-12-01

Humans are interfering with global climate, increasing the risk of serious consequences for human society and the natural environment. As the scientific evidence builds, however, so does the public controversy surrounding this issue. Why is climate change so contentious? What makes it so hard to comprehend? I argue that there is no single reason for this, but rather a perfect storm of multiple confounding factors; scientific, historical, ideological, psychological and even physiological in nature. Education—of both the messengers and the audience—can play a critical role in surmounting many of the common barriers to understanding, accepting, and acting this important issue.

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

PubMed

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

Mechanochemical Preparation of Stable Sub-100 nm γ-Cyclodextrin:Buckminsterfullerene (C60) Nanoparticles by Electrostatic or Steric Stabilization.

PubMed

Van Guyse, Joachim F R; de la Rosa, Victor R; Hoogenboom, Richard

2018-02-21

Buckminster fullerene (C 60 )'s main hurdle to enter the field of biomedicine is its low bioavailability, which results from its extremely low water solubility. A well-known approach to increase the water solubility of C 60 is by complexation with γ-cyclodextrins. However, the formed complexes are not stable in time as they rapidly aggregate and eventually precipitate due to attractive intermolecular forces, a common problem in inclusion complexes of cyclodextrins. In this study we attempt to overcome the attractive intermolecular forces between the complexes by designing custom γ-cyclodextrin (γCD)-based supramolecular hosts for C 60 that inhibit the aggregation found in native γCD-C 60 complexes. The approach entails the introduction of either repulsive electrostatic forces or increased steric hindrance to prevent aggregation, thus enhancing the biomedical application potential of C 60 . These modifications have led to new sub-100 nm nanostructures that show long-term stability in solution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Trends and interannual variability of mass and steric sea level in the Tropical Asian Seas

NASA Astrophysics Data System (ADS)

Kleinherenbrink, Marcel; Riva, Riccardo; Frederikse, Thomas; Merrifield, Mark; Wada, Yoshihide

2017-08-01

The mass and steric components of sea level changes have been separated in the Tropical Asian Seas (TAS) using a statistically optimal combination of Jason satellite altimetry, GRACE satellite gravimetry, and ocean reanalyses. Using observational uncertainties, statistically optimally weighted time series for both components have been obtained in four regions within the TAS over the period January 2005 to December 2012. The mass and steric sea level variability is regressed with the first two principal components (PC1&2) of Pacific equatorial wind stress and the Dipole Mode Index (DMI). Sea level in the South China Sea is not affected by any of the indices. Steric variability in the TAS is largest in the deep Banda and Celebes seas and is affected by both PCs and the DMI. Mass variability is largest on the continental shelves, which is primarily controlled by PC1. We argue that a water flux from the Western Tropical Pacific Ocean is the cause for mass variability in the TAS. The steric trends are about 2 mm yr-1 larger than the mass trends in the TAS. A significant part of the mass trend can be explained by the aforementioned indices and the nodal cycle. Trends obtained from fingerprints of mass redistribution are statistically equal to mass trends after subtracting the nodal cycle and the indices. Ultimately, the effect of omitting the TAS in global sea level budgets is estimated to be 0.3 mm yr-1.

The origin of the ligand-controlled regioselectivity in Rh-catalyzed [(2 + 2) + 2] carbocyclizations: steric vs. stereoelectronic effects.

PubMed

Crandell, Douglas W; Mazumder, Shivnath; Evans, P Andrew; Baik, Mu-Hyun

2015-12-01

Density functional theory calculations demonstrate that the reversal of regiochemical outcome of the addition for substituted methyl propiolates in the rhodium-catalyzed [(2 + 2) + 2] carbocyclization with PPh 3 and ( S )-xyl-binap as ligands is both electronically and sterically controlled. For example, the ester functionality polarizes the alkyne π* orbital to favor overlap of the methyl-substituted terminus of the alkyne with the p π -orbital of the alkenyl fragment of the rhodacycle during alkyne insertion with PPh 3 as the ligand. In contrast, the sterically demanding xyl-binap ligand cannot accommodate the analogous alkyne orientation, thereby forcing insertion to occur at the sterically preferred ester terminus, overriding the electronically preferred orientation for alkyne insertion.

Designing Caregiver-Implemented Shared-Reading Interventions to Overcome Implementation Barriers

ERIC Educational Resources Information Center

Justice, Laura M.; Logan, Jessica R.; Damschroder, Laura

2015-01-01

Purpose: This study presents an application of the theoretical domains framework (TDF; Michie et al., 2005), an integrative framework drawing on behavior-change theories, to speech-language pathology. Methods: A multistep procedure was used to identify barriers affecting caregivers' implementation of shared-reading interventions with their…

Kidney Exchange to Overcome Financial Barriers to Kidney Transplantation.

PubMed

Rees, M A; Dunn, T B; Kuhr, C S; Marsh, C L; Rogers, J; Rees, S E; Cicero, A; Reece, L J; Roth, A E; Ekwenna, O; Fumo, D E; Krawiec, K D; Kopke, J E; Jain, S; Tan, M; Paloyo, S R

2017-03-01

Organ shortage is the major limitation to kidney transplantation in the developed world. Conversely, millions of patients in the developing world with end-stage renal disease die because they cannot afford renal replacement therapy-even when willing living kidney donors exist. This juxtaposition between countries with funds but no available kidneys and those with available kidneys but no funds prompts us to propose an exchange program using each nation's unique assets. Our proposal leverages the cost savings achieved through earlier transplantation over dialysis to fund the cost of kidney exchange between developed-world patient-donor pairs with immunological barriers and developing-world patient-donor pairs with financial barriers. By making developed-world health care available to impoverished patients in the developing world, we replace unethical transplant tourism with global kidney exchange-a modality equally benefitting rich and poor. We report the 1-year experience of an initial Filipino pair, whose recipient was transplanted in the United states with an American donor's kidney at no cost to him. The Filipino donor donated to an American in the United States through a kidney exchange chain. Follow-up care and medications in the Philippines were supported by funds from the United States. We show that the logistical obstacles in this approach, although considerable, are surmountable. © 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

13C and 1H nuclear magnetic resonance of methyl-substituted acetophenones and methyl benzoates: steric hindrance and inhibited conjugation.

PubMed

Budesínský, Milos; Kulhánek, Jirí; Böhm, Stanislav; Cigler, Petr; Exner, Otto

2004-10-01

The 1H and 13C NMR spectra of 14 methyl-substituted acetophenones and 14 methyl-substituted methyl benzoates were assigned and interpreted with respect to the conformation of the C(ar)-C(O) bond. The substituent effects are proportional in the two series and can be divided into polar and steric: each has different effects on the 13C SCS of the individual atoms. In the case of C atoms C(O), C(1) and CH3(CO), the steric effects were quantitatively separated by comparing SCS in the ortho and para positions. The steric effects are proportional for the individual C atoms and also to steric effects estimated from other physical quantities. However, they do not depend simply on the angle of torsion phi of the functional group as anticipated hitherto. A better description distinguishes two classes of compounds: sterically not hindered or slightly hindered planar molecules and strongly sterically hindered, markedly non-planar. In order to confirm this reasoning without empirical correlations, the J(C,C) coupling constants were measured for three acetophenone derivatives labeled with 13C in the acetyl methyl group. The constants confirm unambiguously the conformation of 2-methylacetophenone; their zero values are in accord with the conformation of 2,6-dimethylacetophenone. The zero values in the unsubstituted acetophenone are at variance with previous erroneous report but all J(C,C) values are in accord with calculations at the B3LYP/6-311++G(2d,2p)//B3LYP/6-311+G(d,p) level. Copyright 2004 John Wiley & Sons, Ltd.

The role of "blebbing" in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans

USGS Publications Warehouse

Knickerbocker, C.; Nordstrom, D. Kirk; Southam, G.

2000-01-01

Brimstone Basin, in southeastern Yellowstone National Park, Wyoming is an ancient hydrothermal area containing solfataric alteration. Drainage waters flowing from Brimstone Basin had pH values as low as 1.23 and contained up to 1.7×106 MPN/ml acidophilic sulfur-oxidizing bacteria. Thiobacillus thiooxidans was the dominant sulfur-oxidizing bacterium recovered from an enrichment culture and was used in a structural examination of bacterial sulfur oxidation. Growth in these sulfur cultures occurred in two phases with cells in association with the macroscopic sulfur grains and in suspension above these grains. Colonization of sulfur grains by individual cells and microcolonies was facilitated by organic material that appeared to be responsible for bacterial adhesion. Transmission electron microscopy of negatively stained (2% [wt./vol.] uranyl acetate), sulfur-grown T. thiooxidans revealed extensive membrane blebbing (sloughing of outer membrane vesicles) and the presence of approximately 100 nm sized sulfur particles adsorbed to membrane material surrounding individual bacteria. Sulfite-grown bacteria did not possess membrane blebs. The amphipathic nature of these outer membrane vesicles appear to be responsible for overcoming the hydrophobic barrier necessary for the growth of T. thiooxidans on elemental sulfur.

Barriers to Immunizations and Strategies to Enhance Immunization Rates in Adults with Autoimmune Inflammatory Diseases.

PubMed

Kirchner, Elizabeth; Ruffing, Victoria

2017-02-01

For as long as there have been immunizations, there have been barriers to them. Immunization rates in the United States are below target. Rheumatologists and rheumatology practitioners need to understand the issues of immunizations in patients with autoimmune inflammatory disease to identify and overcome barriers to immunization. Several strategies for overcoming these barriers are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Mass-induced sea level variations in the Red Sea from GRACE, steric-corrected altimetry, in situ bottom pressure records, and hydrographic observations

NASA Astrophysics Data System (ADS)

Feng, W.; Lemoine, J.-M.; Zhong, M.; Hsu, H. T.

2014-08-01

An annual amplitude of ∼18 cm mass-induced sea level variations (SLV) in the Red Sea is detected from the Gravity Recovery and Climate Experiment (GRACE) satellites and steric-corrected altimetry from 2003 to 2011. The annual mass variations in the region dominate the mean SLV, and generally reach maximum in late January/early February. The annual steric component of the mean SLV is relatively small (<3 cm) and out of phase of the mass-induced SLV. In situ bottom pressure records at the eastern coast of the Red Sea validate the high mass variability observed by steric-corrected altimetry and GRACE. In addition, the horizontal water mass flux of the Red Sea estimated from GRACE and steric-corrected altimetry is validated by hydrographic observations.

Evidence-based surgery: barriers, solutions, and the role of evidence synthesis.

PubMed

Garas, George; Ibrahim, Amel; Ashrafian, Hutan; Ahmed, Kamran; Patel, Vanash; Okabayashi, Koji; Skapinakis, Petros; Darzi, Ara; Athanasiou, Thanos

2012-08-01

Surgery is a rapidly evolving field, making the rigorous testing of emerging innovations vital. However, most surgical research fails to employ randomized controlled trials (RCTs) and has particularly been based on low-quality study designs. Subsequently, the analysis of data through meta-analysis and evidence synthesis is particularly difficult. Through a systematic review of the literature, this article explores the barriers to achieving a strong evidence base in surgery and offers potential solutions to overcome the barriers. Many barriers exist to evidence-based surgical research. They include enabling factors, such as funding, time, infrastructure, patient preference, ethical issues, and additionally barriers associated with specific attributes related to researchers, methodologies, or interventions. Novel evidence synthesis techniques in surgery are discussed, including graphics synthesis, treatment networks, and network meta-analyses that help overcome many of the limitations associated with existing techniques. They offer the opportunity to assess gaps and quantitatively present inconsistencies within the existing evidence of RCTs. Poorly or inadequately performed RCTs and meta-analyses can give rise to incorrect results and thus fail to inform clinical practice or revise policy. The above barriers can be overcome by providing academic leadership and good organizational support to ensure that adequate personnel, resources, and funding are allocated to the researcher. Training in research methodology and data interpretation can ensure that trials are conducted correctly and evidence is adequately synthesized and disseminated. The ultimate goal of overcoming the barriers to evidence-based surgery includes the improved quality of patient care in addition to enhanced patient outcomes.

Barriers to Asthma Management as Identified by School Nurses

ERIC Educational Resources Information Center

Quaranta, Judith E.; Spencer, Gale A.

2016-01-01

Asthma rates are increasing in children. School nurses have opportunities to care for children with asthma but need to overcome barriers impacting their ability to manage asthma in the school setting. This study (a) assessed barriers present in the school setting, (b) determined the impact of barriers on performance of asthma management behaviors,…

Increasing Rural Adults' Participation in Collegial Programs: Exemplary Programs. Proceedings of the Rural Action Conference "Programs and Activities to Overcome Barriers to Rural Adult Participation in Postsecondary Education" (Blacksburg, Virginia, June 1-3, 1987).

ERIC Educational Resources Information Center

Sullins, W. Robert, Ed.; And Others

Approximately 85 educators from six states participated in a regional conference designed to showcase exemplary and collaborative programs to overcome many of the barriers faced by rural adults in pursuing higher education. After the keynote address, "The Role of Adult Learning in Revitalizing Rural Communities," by Cornelia Butler Flora, the…

Cultural Barriers to Change in Assessment Practices in Higher Education

ERIC Educational Resources Information Center

Jenkins, Deborah Bainer

2007-01-01

The culture at the authors' institution raised barriers to changing from traditional assessment to portfolio assessment in the doctoral program. A Culture of Independence presented barriers of time and functional inadequacy. A Culture of Compliance raised trust, group process, and membership issues. These barriers were managed and overcome using…

Peptide probes reveal a hydrophobic steric ratchet in the anthrax toxin protective antigen translocase

PubMed Central

Colby, Jennifer M.; Krantz, Bryan A.

2015-01-01

Anthrax toxin is a tripartite virulence factor produced by Bacillus anthracis during infection. Under acidic endosomal pH conditions, the toxin's protective antigen (PA) component forms a transmembrane channel in host cells. The PA channel then translocates its two enzyme components, lethal factor (LF) and edema factor (EF), into the host cytosol under the proton motive force (PMF). Protein translocation under a PMF is catalyzed by a series of nonspecific polypeptide binding sites, called clamps. A 10-residue guest/host peptide model system, KKKKKXXSXX, was used to functionally probe polypeptide-clamp interactions within wild-type PA channels. The guest residues were Thr, Ala, Leu, Phe, Tyr, and Trp. In steady-state translocation experiments, the channel blocked most tightly with peptides that had increasing amounts of nonpolar surface area. Cooperative peptide binding was observed in the Trp-containing peptide sequence but not the other tested sequences. Trp substitutions into a flexible, uncharged linker between LF amino-terminal domain and diphtheria toxin A chain expedited translocation. Therefore, peptide clamp sites in translocase channels can sense large steric features (like tryptophan) in peptides; and while these steric interactions may make a peptide translocate poorly, in the context of folded domains they can make the protein translocate more rapidly presumably via a hydrophobic steric ratchet mechanism. PMID:26363343

Overcoming Barriers for Displaced Homemakers in Nontraditional Occupations. A Manual of Strategies.

ERIC Educational Resources Information Center

Far West Lab. for Educational Research and Development, San Francisco, CA.

This manual examines problems the displaced homemaker encounters on the job and offers strategies which vocational educators, counselors, and other service providers can suggest to nontraditional students for overcoming these problems. A brief overview of the displaced homemaker is provided and the term "nontraditional occupation" is defined. An…

Steric stabilization of nonaqueous silicon slips. I - Control of particle agglomeration and packing. II - Pressure casting of powder compacts

NASA Technical Reports Server (NTRS)

Kerkar, Awdhoot V.; Henderson, Robert J. M.; Feke, Donald L.

1990-01-01

The application of steric stabilization to control particle agglomeration and packing of silicon powder in benzene and trichloroethylene is reported. The results provide useful guidelines for controlling unfavorable particle-particle interactions during nonaqueous processing of silicon-based ceramic materials. The application of steric stabilization to the control and improvement of green processing of nonaqueous silicon slips in pressure consolidation is also demonstrated.

Improving halide-containing magnesium-ion electrolyte performance via sterically hindered alkoxide ligands

NASA Astrophysics Data System (ADS)

Nist-Lund, Carl A.; Herb, Jake T.; Arnold, Craig B.

2017-09-01

While homoleptic magnesium dialkoxides (MgR2, R = alkoxide) have shown promise as precursors for magnesium-ion electrolytes, the effect of ligand steric bulk on the performance of electrolytes based on these compounds is not fully understood. Increasing steric hindrance, studied via R groups with additional phenyl moieties, produces electrolytes with sequentially lower deposition overpotentials (less than -90 mV), higher purity Mg deposits (ca. 100% Mg), and lower overall cell impedances. The two largest alkoxide ligands show consistent cycling behavior and low stripping and plating overpotentials over 200 constant-current plating/stripping cycles. A deep-red visual change and the presence of large solubilized magnesium particulates above 450 nm in size is observed in an electrolyte containing magnesium bis(triphenylmethoxide) and aluminum chloride in contact with an abraded magnesium anode. Further morphological and impedance characterization show that this electrolyte system rapidly activates the magnesium metal anode surface to produce low overpotentials and, as such, is a candidate for further investigation.

Using steric hindrance to design new inhibitors of class C beta-lactamases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trehan, Indi; Morandi, F.; Blaszczak, L.C.

{beta}-lactamases confer resistance to {beta}-lactam antibiotics such as penicillins and cephalosporins. However, {beta}-lactams that form an acyl-intermediate with the enzyme but subsequently are hindered from forming a catalytically competent conformation seem to be inhibitors of {beta}-lactamases. This inhibition may be imparted by specific groups on the ubiquitous R1 side chain of {beta}-lactams, such as the 2-amino-4-thiazolyl methoxyimino (ATMO) group common among third-generation cephalosporins. Using steric hindrance of deacylation as a design guide, penicillin and carbacephem substrates were converted into effective {beta}-lactamase inhibitors and antiresistance antibiotics. To investigate the structural bases of inhibition, the crystal structures of the acyl-adducts of themore » penicillin substrate amoxicillin and the new analogous inhibitor ATMO-penicillin were determined. ATMO-penicillin binds in a catalytically incompetent conformation resembling that adopted by third-generation cephalosporins, demonstrating the transferability of such sterically hindered groups in inhibitor design.« less

Overcoming research barriers in Chagas disease-designing effective implementation science.

PubMed

Henao-Martínez, Andrés F; Colborn, Kathryn; Parra-Henao, Gabriel

2017-01-01

Chagas disease is a complex tropical parasitic infection. It affects a significant portion of the population in Latin America, especially in areas of poverty and poor access to health care. It also affects immigrants in high-income countries who lack access to health care due to their legal status. Millions of people are at risk of contracting the disease, and approximately 30 % of chronically infected patients will develop cardiomyopathy. The cost of caring for patients that have been infected is substantial. Basic science research has introduced new concepts and knowledge for the parasite and vector biology as well as better understanding of the pathophysiology of the disease. These research findings nevertheless require effective and timely translation into clinical practice. Likewise, the design of new research projects should account for the multiple system-based barriers. Implementation science facilitates the applicability of research findings and identifies barriers to its execution. Creation of implementation science measures to reach and sustain research programs with greater potential to impact Chagas disease are lacking. This point of view proposes opportunities for implementation science in Chagas disease and strategies for researching effective interventions for preventing and treating the disease.

Promoting Physical Activity: Addressing Barriers and Moving Forward

ERIC Educational Resources Information Center

Beighle, Aaron; Morrow, James R.

2014-01-01

The barriers that keep individuals from adopting and maintaining active lifestyles are very complex. Strategies for overcoming these barriers and to incentivize and assist inactive individuals to benefit from physical activity are necessary. In addition, it is important to examine the impact of public policy on active living. As youth physical…

OXIDATION OF CYCLOHEXANE WITH AIR CATALYZED BY A STERICALLY HINDERED IRON (II) COMPLEX

EPA Science Inventory

Oxidation of Cyclohexane with Air Catalyzed by a Sterically Hindered Iron(II) Complex.


Thomas M. Becker, Michael A. Gonzalez*

United States Environmental Protection Agency; National Risk Management Research Laboratory; Sustainable Technology Division; Clean Pr...

Peptide Probes Reveal a Hydrophobic Steric Ratchet in the Anthrax Toxin Protective Antigen Translocase.

PubMed

Colby, Jennifer M; Krantz, Bryan A

2015-11-06

Anthrax toxin is a tripartite virulence factor produced by Bacillus anthracis during infection. Under acidic endosomal pH conditions, the toxin's protective antigen (PA) component forms a transmembrane channel in host cells. The PA channel then translocates its two enzyme components, lethal factor and edema factor, into the host cytosol under the proton motive force. Protein translocation under a proton motive force is catalyzed by a series of nonspecific polypeptide binding sites, called clamps. A 10-residue guest/host peptide model system, KKKKKXXSXX, was used to functionally probe polypeptide-clamp interactions within wild-type PA channels. The guest residues were Thr, Ala, Leu, Phe, Tyr, and Trp. In steady-state translocation experiments, the channel blocked most tightly with peptides that had increasing amounts of nonpolar surface area. Cooperative peptide binding was observed in the Trp-containing peptide sequence but not the other tested sequences. Trp substitutions into a flexible, uncharged linker between the lethal factor amino-terminal domain and diphtheria toxin A chain expedited translocation. Therefore, peptide-clamp sites in translocase channels can sense large steric features (like tryptophan) in peptides, and while these steric interactions may make a peptide translocate poorly, in the context of folded domains, they can make the protein translocate more rapidly presumably via a hydrophobic steric ratchet mechanism. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Determining the Effective Density and Stabilizer Layer Thickness of Sterically Stabilized Nanoparticles

PubMed Central

2016-01-01

A series of model sterically stabilized diblock copolymer nanoparticles has been designed to aid the development of analytical protocols in order to determine two key parameters: the effective particle density and the steric stabilizer layer thickness. The former parameter is essential for high resolution particle size analysis based on analytical (ultra)centrifugation techniques (e.g., disk centrifuge photosedimentometry, DCP), whereas the latter parameter is of fundamental importance in determining the effectiveness of steric stabilization as a colloid stability mechanism. The diblock copolymer nanoparticles were prepared via polymerization-induced self-assembly (PISA) using RAFT aqueous emulsion polymerization: this approach affords relatively narrow particle size distributions and enables the mean particle diameter and the stabilizer layer thickness to be adjusted independently via systematic variation of the mean degree of polymerization of the hydrophobic and hydrophilic blocks, respectively. The hydrophobic core-forming block was poly(2,2,2-trifluoroethyl methacrylate) [PTFEMA], which was selected for its relatively high density. The hydrophilic stabilizer block was poly(glycerol monomethacrylate) [PGMA], which is a well-known non-ionic polymer that remains water-soluble over a wide range of temperatures. Four series of PGMAx–PTFEMAy nanoparticles were prepared (x = 28, 43, 63, and 98, y = 100–1400) and characterized via transmission electron microscopy (TEM), dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS). It was found that the degree of polymerization of both the PGMA stabilizer and core-forming PTFEMA had a strong influence on the mean particle diameter, which ranged from 20 to 250 nm. Furthermore, SAXS was used to determine radii of gyration of 1.46 to 2.69 nm for the solvated PGMA stabilizer blocks. Thus, the mean effective density of these sterically stabilized particles was calculated and determined to lie between 1.19 g

Do we need to overcome barriers to learning in the workplace for foundation trainees rotating in neurosurgery in order to improve training satisfaction?

PubMed

Phan, Pho Nh; Patel, Keyur; Bhavsar, Amar; Acharya, Vikas

2016-01-01

Junior doctors go through a challenging transition upon qualification; this repeats every time they start a rotation in a new department. Foundation level doctors (first 2 years postqualification) in neurosurgery are often new to the specialty and face various challenges that may result in significant workplace dissatisfaction. The neurosurgical environment is a clinically demanding area with a high volume of unwell patients and frequent emergencies - this poses various barriers to learning in the workplace for junior doctors. We identify a number of key barriers and review ideas that can be trialed in the department to overcome them. Through an evaluation of current suggestions in the literature, we propose that learning opportunities need to be made explicit to junior doctors in order to encourage them to participate as a member of the team. We consider ideas for adjustments to the induction program and the postgraduate medical curriculum to shift the focus from medical knowledge to improving confidence and clinical skills in newly qualified doctors. Despite being a powerful window for opportunistic learning, the daily ward round is unfortunately not maximized and needs to be more learner focused while maintaining efficiency and time consumption. Finally, we put forward the idea of an open forum where trainees can talk about their learning experiences, identify subjective barriers, and suggest solutions to senior doctors. This would be achieved through departmental faculty development. These interventions are presented within the context of the neurosurgical ward; however, they are transferable and can be adapted in other specialties and departments.

Ion-Conserving Modified Poisson-Boltzmann Theory Considering a Steric Effect in an Electrolyte

NASA Astrophysics Data System (ADS)

Sugioka, Hideyuki

2016-12-01

The modified Poisson-Nernst-Planck (MPNP) and modified Poisson-Boltzmann (MPB) equations are well known as fundamental equations that consider a steric effect, which prevents unphysical ion concentrations. However, it is unclear whether they are equivalent or not. To clarify this problem, we propose an improved free energy formulation that considers a steric limit with an ion-conserving condition and successfully derive the ion-conserving modified Poisson-Boltzmann (IC-MPB) equations that are equivalent to the MPNP equations. Furthermore, we numerically examine the equivalence by comparing between the IC-MPB solutions obtained by the Newton method and the steady MPNP solutions obtained by the finite-element finite-volume method. A surprising aspect of our finding is that the MPB solutions are much different from the MPNP (IC-MPB) solutions in a confined space. We consider that our findings will significantly contribute to understanding the surface science between solids and liquids.

Mid-Atlantic Wind - Overcoming the Challenges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel F. Ancona III; Kathryn E. George; Lynn Sparling

2012-06-29

This study, supported by the US Department of Energy, Wind Powering America Program, Maryland Department of Natural Resources and Chesapeake Bay Foundation, analyzed barriers to wind energy development in the Mid-Atlantic region along with options for overcoming or mitigating them. The Mid-Atlantic States including Delaware, Maryland, North Carolina and Virginia, have excellent wind energy potential and growing demand for electricity, but only two utility-scale projects have been installed to date. Reasons for this apathetic development of wind resources were analyzed and quantified for four markets. Specific applications are: 1) Appalachian mountain ridgeline sites, 2) on coastal plains and peninsulas, 3)more » at shallow water sites in Delaware and Chesapeake Bays, Albemarle and Pamlico Sounds, and 4) at deeper water sites off the Atlantic coast. Each market has distinctly different opportunities and barriers. The primary barriers to wind development described in this report can be grouped into four categories; state policy and regulatory issues, wind resource technical uncertainty, economic viability, and public interest in environmental issues. The properties of these typologies are not mutually independent and do interact. The report concluded that there are no insurmountable barriers to land-based wind energy projects and they could be economically viable today. Likewise potential sites in sheltered shallow waters in regional bay and sounds have been largely overlooked but could be viable currently. Offshore ocean-based applications face higher costs and technical and wind resource uncertainties. The ongoing research and development program, revision of state incentive policies, additional wind measurement efforts, transmission system expansion, environmental baseline studies and outreach to private developers and stakeholders are needed to reduce barriers to wind energy development.« less

Overcoming Barriers to the Sexual Expression of Women with Developmental Disabilities.

ERIC Educational Resources Information Center

Stinson, Jennifer; Christian, LeeAnn; Dotson, Lori Ann

2002-01-01

This article discusses barriers to sexual fulfillment faced by women with developmental disabilities, including: access to gynecological healthcare, limited choices regarding reproductive issues, lack of sex education, and prevailing negative stereotypes that affect the way women are viewed by others and the way they view themselves.…

Newborn screening progress in developing countries--overcoming internal barriers.

PubMed

Padilla, Carmencita D; Krotoski, Danuta; Therrell, Bradford L

2010-04-01

Newborn screening is an important public health measure aimed at early identification and management of affected newborns thereby lowering infant morbidity and mortality. It is a comprehensive system of education, screening, follow-up, diagnosis, treatment/management, and evaluation that must be institutionalized and sustained within public health systems often challenged by economic, political, and cultural considerations. As a result, developing countries face unique challenges in implementing and expanding newborn screening that can be grouped into the following categories: (1) planning, (2) leadership, (3) medical support, (4) technical support, (5) logistical support, (6) education, (7) protocol and policy development, (8) administration, (9) evaluation, and (10) sustainability. We review some of the experiences in overcoming implementation challenges in developing newborn screening programs, and discuss recent efforts to encourage increased newborn screening through support networking and information exchange activities in 2 regions-the Asia Pacific and the Middle East/North Africa. Copyright 2010 Elsevier Inc. All rights reserved.

Establishment of Constraints on Amyloid Formation Imposed by Steric Exclusion of Globular Domains.

PubMed

Azizyan, Rafayel A; Garro, Adriana; Radkova, Zinaida; Anikeenko, Alexey; Bakulina, Anastasia; Dumas, Christian; Kajava, Andrey V

2018-06-01

In many disease-related and functional amyloids, the amyloid-forming regions of proteins are flanked by globular domains. When located in close vicinity of the amyloid regions along the chain, the globular domains can prevent the formation of amyloids because of the steric repulsion. Experimental tests of this effect are few in number and non-systematic, and their interpretation is hampered by polymorphism of amyloid structures. In this situation, modeling approaches that use such a clear-cut criterion as the steric tension can give us highly trustworthy results. In this work, we evaluated this steric effect by using molecular modeling and dynamics. As an example, we tested hybrid proteins containing an amyloid-forming fragment of Aβ peptide (17-42) linked to one or two globular domains of GFP. Searching for the shortest possible linker, we constructed models with pseudo-helical arrangements of the densely packed GFPs around the Aβ amyloid core. The molecular modeling showed that linkers of 7 and more residues allow fibrillogenesis of the Aβ-peptide flanked by GFP on one side and 18 and more residues when Aβ-peptide is flanked by GFPs on both sides. Furthermore, we were able to establish a more general relationship between the size of the globular domains and the length of the linkers by using analytical expressions and rigid body simulations. Our results will find use in planning and interpretation of experiments, improvement of the prediction of amyloidogenic regions in proteins, and design of new functional amyloids carrying globular domains. Copyright © 2018 Elsevier Ltd. All rights reserved.

Tuning main group redox chemistry through steric loading: subvalent Group 13 metal complexes of carbazolyl ligands.

PubMed

Mansaray, Hassanatu B; Kelly, Michael; Vidovic, Dragoslav; Aldridge, Simon

2011-05-02

The ability of substituted carbazol-9-yl systems to ligate in σ fashion through the amido N-donor, or to adopt alternative coordination modes through the π system of the central five-membered ring, can be tuned by systematic variation in the steric demands of substituents in the 1- and 8-positions. The differing affinities of the two modes of coordination for hard and soft metal centres can be shown to influence not only cation selectivity, but also the redox properties of the metal centre. Thus, the highly sterically sterically demanding 1,3,6,8-tetra-tert-butylcarbazolyl ligand can be used to generate the structurally characterised amido-indium(I) complex, [{(tBu(4)carb)In}(n)], (together with its isostructural thallium counterpart) in which the metal centre interacts with the central pyrrolyl ring in η(3) fashion [d(In-N)=2.679(3) Å; d(In-C)=2.819(3), 2.899(3) Å]. By contrast, the smaller 3,6-di-tert-butylcarbazolyl system is less able to restrict the metal centre from binding at the anionic nitrogen donor in the plane of the carbazolyl ligand (i.e. in σ fashion). Analogous chemistry with In(I) precursors therefore leads to disproportionation to the much harder In(II) [and In(0)], and the formation of the mixed-valence product, [In(2){In(2)(tBu(2)carb)(6)}], a homoleptic molecular [In(4)(NR(2))(6)] system. This chemistry reveals a flexibility of ligation for carbazolyl systems that contrasts markedly with that of the similarly sterically encumbered terphenyl ligand family. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The role of atomic level steric effects and attractive forces in protein folding.

PubMed

Lammert, Heiko; Wolynes, Peter G; Onuchic, José N

2012-02-01

Protein folding into tertiary structures is controlled by an interplay of attractive contact interactions and steric effects. We investigate the balance between these contributions using structure-based models using an all-atom representation of the structure combined with a coarse-grained contact potential. Tertiary contact interactions between atoms are collected into a single broad attractive well between the C(β) atoms between each residue pair in a native contact. Through the width of these contact potentials we control their tolerance for deviations from the ideal structure and the spatial range of attractive interactions. In the compact native state dominant packing constraints limit the effects of a coarse-grained contact potential. During folding, however, the broad attractive potentials allow an early collapse that starts before the native local structure is completely adopted. As a consequence the folding transition is broadened and the free energy barrier is decreased. Eventually two-state folding behavior is lost completely for systems with very broad attractive potentials. The stabilization of native-like residue interactions in non-perfect geometries early in the folding process frequently leads to structural traps. Global mirror images are a notable example. These traps are penalized by the details of the repulsive interactions only after further collapse. Successful folding to the native state requires simultaneous guidance from both attractive and repulsive interactions. Copyright © 2011 Wiley Periodicals, Inc.

Lutetium functionalities supported by a sterically encumbered β-diketiminate ligand

DOE PAGES

Beattie, Ross J.; Sutton, Andrew D.; Scott, Brian L.; ...

2018-01-06

The sterically encumbered NacNac ligand, [HC(MeCNAr) 2] – (Ar = 2,6- i-Pr 2C 6H 3), was investigated as a platform for supporting Lu-halide complexes, sought for their potential capability of being further converted into hydrocarbyl derivatives via metathetical chemistries with alkali metal alkyls. As a result, these substituted analogs were targeted as potentially viable candidates for alkane elimination chemistries, with an eye towards the formation of an isolable Lu-alkylidene fragment.

Supporting Instructors in Overcoming Self-Efficacy and Background Barriers to Adoption

ERIC Educational Resources Information Center

Reid, Pat

2017-01-01

Most academic technology areas of higher education institutes do not feel faculty technology adoption is adequate (Hartman (EDUCAUSE Rev 43(6), 2008)). Among the barriers to instructional technology adoption are faculty self-efficacy and background. Self-efficacy encompasses the faculty member's belief or confidence in his ability to succeed.…

Perceived barriers to infection prevention and control for nursing home certified nursing assistants: a qualitative study.

PubMed

Travers, Jasmine; Herzig, Carolyn T A; Pogorzelska-Maziarz, Monika; Carter, Eileen; Cohen, Catherine C; Semeraro, Patricia K; Bjarnadottir, Ragnhildur I; Stone, Patricia W

2015-01-01

Healthcare-associated infections, while preventable, result in increased morbidity and mortality in nursing home (NH) residents. Frontline personnel, such as certified nursing assistants (CNAs), are crucial to successful implementation of infection prevention and control (IPC) practices. The purpose of this study was to explore barriers to implementing and maintaining IPC practices for NH CNAs as well as to describe strategies used to overcome these barriers. We conducted a multi-site qualitative study of NH personnel important to infection control. Audio-recorded interviews were transcribed verbatim and transcripts were analyzed using conventional content analysis. Five key themes emerged as perceived barriers to effective IPC for CNAs: 1) language/culture; 2) knowledge/training; 3) per-diem/part-time staff; 4) workload; and 5) accountability. Strategies used to overcome these barriers included: translating in-services, hands on training, on-the-spot training for per-diem/part-time staff, increased staffing ratios, and inclusion/empowerment of CNAs. Understanding IPC barriers and strategies to overcome these barriers may better enable NHs to achieve infection reduction goals. Copyright © 2015 Elsevier Inc. All rights reserved.

Overcoming barriers to cancer-helpline professionals providing decision support for callers: an implementation study.

PubMed

Stacey, Dawn; Chambers, Suzanne K; Jacobsen, Mary Jane; Dunn, Jeff

2008-11-01

To evaluate the effect of an intervention on healthcare professionals' perceptions of barriers influencing their provision of decision support for callers facing cancer-related decisions. A pre- and post-test study guided by the Ottawa Model of Research Use. Australian statewide cancer call center that provides public access to information and supportive cancer services. 34 nurses, psychologists, and other allied healthcare professionals at the cancer call center. Participants completed baseline measures and, subsequently, were exposed to an intervention that included a decision support tutorial, coaching protocol, and skill-building workshop. Strategies were implemented to address organizational barriers. Perceived barriers and facilitators influencing provision of decision support, decision support knowledge, quality of decision support provided to standardized callers, and call length. Postintervention participants felt more prepared, confident in providing decision support, and aware of decision support resources. They had a stronger belief that providing decision support was within their role. Participants significantly improved their knowledge and provided higher-quality decision support to standardized callers without changing call length. The implementation intervention overcame several identified barriers that influenced call center professionals when providing decision support. Nurses and other helpline professionals have the potential to provide decision support designed to help callers understand cancer information, clarify their values associated with their options, and reduce decisional conflict. However, they require targeted education and organizational interventions to reduce their perceived barriers to providing decision support.

Overcoming barriers to work participation for patients with postpoliomyelitis syndrome.

PubMed

Ten Katen, Kim; Beelen, Anita; Nollet, Frans; Frings-Dresen, Monique H W; Sluiter, Judith K

2011-01-01

This study aimed to explore the perceived work ability of patients with postpoliomyelitis syndrome (PPS), to identify barriers and factors that are impeding or conducive, respectively, to work participation, and to identify possible interventions. Qualitative cross-sectional interview study with 17 subjects with PPS, 12 women and 5 men, mean age 49 years (SD: 11). Semi-structured interviews were held with the subjects in their homes, with the aid of a topic list. The COREQ criteria list for qualitative research was used as guideline in design and analysis. Thirteen out of 17 subjects rated their work ability six or higher on a scale from 0 to 10. Most subjects worked in an administrative, educational or managerial function. Five subjects stopped working, four worked between 0 and 20 h/week and eight worked between 20 and 40 h/week. Factors conducive to working were physical adaptations in the workplace, accessibility of the workplace and high decision latitude. Barriers to full work ability in PPS patients were high physical job demands, low social support and the symptoms of PPS, especially fatigue and pain. These findings suggest that work-oriented interventions aimed at preventing PPS patients from dropping out of the workforce should primarily focus on reducing physical job demands, arranging adaptations in the workplace and increasing job control.

Unitary Responses in Frog Olfactory Epithelium to Sterically Related Molecules at Low Concentrations

PubMed Central

Getchell, Thomas V.

1974-01-01

Responses of receptor cells in the frog's olfactory epithelium were recorded using platinum-black metal-filled microelectrodes. Spontaneous activity varied over a wide range from 0.07 to 1.8 spikes/s. Mean interspike intervals ranged from 13.7 to 0.5 s. Excitatory responses to six sterically related compounds at low concentrations were investigated. Stimuli were delivered in an aqueous medium. Thresholds for impulse initiation varied from greater than 1 mM down to the nanomolar concentration range. Thresholds of different olfactory receptors to the same stimulus could vary by several log units. Thresholds of the same receptor cell to different stimuli could be within the same order of magnitude, or could vary by as much as 5 log units. Based upon quantitative measures of stimulus-evoked excitatory responses it appeared that some receptors did not discriminate among sterically related molecules, whereas other receptors clearly discriminated between stimuli which evoke similar odor sensations. PMID:4211101

Conducting a Multisite Education Research Project: Strategies to Overcome the Barriers to Achieve the Benefits.

PubMed

Beischel, Kelly P; Hart, Julie; Turkelson, Sandra L

2016-01-01

Multisite education research projects have many benefits as well as perceived barriers. In this article, we share our experiences with a multisite education research project and the barriers we overcame to reap the benefits. The outcome of our research resulted in increased rigor, role-modeling professional collaboration, and promotion of future multisite education studies. The strategies presented in this article will help alleviate perceived barriers and ameliorate the process of conducting multisite education research studies.

miR-155 Deletion in Mice Overcomes Neuron-Intrinsic and Neuron-Extrinsic Barriers to Spinal Cord Repair.

PubMed

Gaudet, Andrew D; Mandrekar-Colucci, Shweta; Hall, Jodie C E; Sweet, David R; Schmitt, Philipp J; Xu, Xinyang; Guan, Zhen; Mo, Xiaokui; Guerau-de-Arellano, Mireia; Popovich, Phillip G

2016-08-10

Axon regeneration after spinal cord injury (SCI) fails due to neuron-intrinsic mechanisms and extracellular barriers including inflammation. microRNA (miR)-155-5p is a small, noncoding RNA that negatively regulates mRNA translation. In macrophages, miR-155-5p is induced by inflammatory stimuli and elicits a response that could be toxic after SCI. miR-155 may also independently alter expression of genes that regulate axon growth in neurons. Here, we hypothesized that miR-155 deletion would simultaneously improve axon growth and reduce neuroinflammation after SCI by acting on both neurons and macrophages. New data show that miR-155 deletion attenuates inflammatory signaling in macrophages, reduces macrophage-mediated neuron toxicity, and increases macrophage-elicited axon growth by ∼40% relative to control conditions. In addition, miR-155 deletion increases spontaneous axon growth from neurons; adult miR-155 KO dorsal root ganglion (DRG) neurons extend 44% longer neurites than WT neurons. In vivo, miR-155 deletion augments conditioning lesion-induced intraneuronal expression of SPRR1A, a regeneration-associated gene; ∼50% more injured KO DRG neurons expressed SPRR1A versus WT neurons. After dorsal column SCI, miR-155 KO mouse spinal cord has reduced neuroinflammation and increased peripheral conditioning-lesion-enhanced axon regeneration beyond the epicenter. Finally, in a model of spinal contusion injury, miR-155 deletion improves locomotor function at postinjury times corresponding with the arrival and maximal appearance of activated intraspinal macrophages. In miR-155 KO mice, improved locomotor function is associated with smaller contusion lesions and decreased accumulation of inflammatory macrophages. Collectively, these data indicate that miR-155 is a novel therapeutic target capable of simultaneously overcoming neuron-intrinsic and neuron-extrinsic barriers to repair after SCI. Axon regeneration after spinal cord injury (SCI) fails due to neuron

The Gendered International School: Barriers to Women Managers' Progression

ERIC Educational Resources Information Center

Sanderson, Ruth Elizabeth; Whitehead, Stephen

2016-01-01

Purpose: The purpose of this paper is to examine the barriers women identify to their promotion in international schools and also the ways in which women can overcome these barriers. Design/methodology/approach: The field of enquiry is international schools, with the study drawing on qualitative research. The researchers interviewed 11 women from…

Barriers and Strategies in Guideline Implementation—A Scoping Review

PubMed Central

Fischer, Florian; Lange, Kerstin; Klose, Kristina; Greiner, Wolfgang; Kraemer, Alexander

2016-01-01

Research indicates that clinical guidelines are often not applied. The success of their implementation depends on the consideration of a variety of barriers and the use of adequate strategies to overcome them. Therefore, this scoping review aims to describe and categorize the most important barriers to guideline implementation. Furthermore, it provides an overview of different kinds of suitable strategies that are tailored to overcome these barriers. The search algorithm led to the identification of 1659 articles in PubMed. Overall, 69 articles were included in the data synthesis. The content of these articles was analysed by using a qualitative synthesis approach, to extract the most important information on barriers and strategies. The barriers to guideline implementation can be differentiated into personal factors, guideline-related factors, and external factors. The scoping review revealed the following aspects as central elements of successful strategies for guideline implementation: dissemination, education and training, social interaction, decision support systems and standing orders. Available evidence indicates that a structured implementation can improve adherence to guidelines. Therefore, the barriers to guideline implementation and adherence need to be analysed in advance so that strategies that are tailored to the specific setting and target groups can be developed. PMID:27417624

Adolescents' struggles with swallowing tablets: barriers, strategies and learning.

PubMed

Hansen, Dana Lee; Tulinius, Ditte; Hansen, Ebba Holme

2008-01-01

To explore adolescents' struggles with taking oral medications. Copenhagen, Denmark. Semi-structured qualitative interviews were conducted with 89 adolescents (33 boys, 56 girls) between the ages of 11 and 20. Adolescents were recruited through four public schools. To identify struggles with taking oral medication, interview transcripts were systematically searched for statements including the terms swallow, chew, crush and eat. Thematic analysis of the identified statements was carried out to reveal dominant themes in the adolescents' accounts. Over one-third of the adolescents spontaneously provided accounts of the difficulties they experienced with taking oral medications, especially with swallowing tablets. Three themes were dominant in their narratives: barriers, strategies and learning. Barriers experienced by the adolescents involved the medications' properties, e.g. taste. Adolescents developed strategies to overcome these barriers, e.g. crushing tablets. Via a process of learning-by-doing and the acquisition of increased experience and autonomy, many adolescents mastered the skill of swallowing tablets. Many adolescents experienced barriers in their attempts to swallow tablets. They developed various strategies to overcome these barriers and gradually mastered taking medicines in a learning-by-doing process.

Math Is Like a Scary Movie? Helping Young People Overcome Math Anxiety

ERIC Educational Resources Information Center

Kulkin, Margaret

2016-01-01

Afterschool teachers who tutor students or provide homework help have a unique opportunity to help students overcome the social or emotional barriers that so often block learning. They can embrace a creative and investigative approach to math learning. Margaret Kulkin's interest in being a math attitude "myth-buster" led her to apply to…

Optical properties and progressive sterical hindering in pyridinium phenoxides

NASA Astrophysics Data System (ADS)

Boeglin, A.; Barsella, A.; Fort, A.; Mançois, F.; Rodriguez, V.; Diemer, V.; Chaumeil, H.; Defoin, A.; Jacques, P.; Carré, C.

2007-07-01

Pyridinium phenoxides are model compounds associating large dipole moments with high optical nonlinearities. A progression of sterically hindered forms of such zwitterions has been synthesized in order to investigate their structure/property relationships. Their UV-vis absorption in acetonitrile has been analyzed as a function of concentration in order to assess the presence of aggregates and the level of protonation. The quadratic optical properties have been measured by the EFISH and hyper-Rayleigh techniques and are interpreted via semi-empirical calculations. The solvation model used leads to results that agree with our experimental findings indicating an increased response for intermediate twist angles.

Overcoming resistance to culture change: nursing home administrators' use of education, training, and communication.

PubMed

Tyler, Denise A; Lepore, Michael; Shield, Renee R; Looze, Jessica; Miller, Susan C

2014-01-01

Nursing home culture change is becoming more prevalent, and research has demonstrated its benefits for nursing home residents and staff-but little is known about the role of nursing home administrators in culture change implementation. The purpose of this study was to determine what barriers nursing home administrators face in implementing culture change practices, and to identify the strategies used to overcome them. The authors conducted in-depth individual interviews with 64 administrators identified through a nationally representative survey. Results showed that a key barrier to culture change implementation reported by administrators was staff, resident, and family member resistance to change. Most nursing home administrators stressed the importance of using communication, education and training to overcome this resistance. Themes emerging around the concepts of communication and education indicate that these efforts should be ongoing, communication should be reciprocal, and that all stakeholders should be included.

Overcoming Resistance to Culture Change: Nursing Home Administrators’ Use of Education, Training and Communication

PubMed Central

Tyler, Denise A.; Lepore, Michael; Shield, Renee R.; Looze, Jessica; Miller, Susan C.

2014-01-01

Nursing home culture change is becoming more prevalent and research has demonstrated its benefits for nursing home residents and staff, but little is known about the role of nursing home administrators in culture change implementation. The purpose of this study was to determine what barriers nursing home administrators faced in implementing culture change practices and to identify the strategies used to overcome these. We conducted in-depth individual interviews with 64 administrators identified through a nationally representative survey. Results showed that a key barrier to culture change implementation reported by administrators was staff, resident and family member resistance to change. Most nursing home administrators stressed the importance of using communication, education and training to overcome this resistance. Themes emerging around the concepts of communication and education indicate that these efforts should be ongoing, communication should be reciprocal, and that all stakeholders should be included. PMID:24266678

New sterically stabilized vesicles based on nonionic surfactant, cholesterol, and poly(ethylene glycol)-cholesterol conjugates.

PubMed Central

Beugin, S; Edwards, K; Karlsson, G; Ollivon, M; Lesieur, S

1998-01-01

Monomethoxypoly(ethylene glycol) cholesteryl carbonates (M-PEG-Chol) with polymer chain molecular weights of 1000 (M-PEG1000-Chol) and 2000 (M-PEG2000-Chol) have been newly synthesized and characterized. Their aggregation behavior in mixture with diglycerol hexadecyl ether (C16G2) and cholesterol has been examined by cryotransmission electron microscopy, high-performance gel exclusion chromatography, and quasielastic light scattering. Nonaggregated, stable, unilamellar vesicles were obtained at low polymer levels with optimal shape and size homogeneity at cholesteryl conjugate/ lipids ratios of 10 mol% M-PEG1000-Chol or 5 mol% M-PEG2000-Chol, corresponding to the theoretically predicted brush conformational state of the PEG chains. At 20 mol% M-PEG1000-Chol or 10 mol% M-PEG2000-Chol, the saturation threshold of the C16G2/cholesterol membrane in polymer is exceeded, and open disk-shaped aggregates are seen in coexistence with closed vesicles. Higher levels up to 30 mol% lead to the complete solubilization of the vesicles into disk-like structures of decreasing size with increasing PEG content. This study underlines the bivalent role of M-PEG-Chol derivatives: while behaving as solubilizing surfactants, they provide an efficient steric barrier, preventing the vesicles from aggregation and fusion over a period of at least 2 weeks. PMID:9635773

Overcoming barriers to investigating mother-infant interactions in the first two hours of life.

PubMed

Powers, Nancy G; Parham, Douglas F; Goldberg, Lynette R

2011-08-01

As a result of the unexpected delays experienced in a study designed to investigate mother-infant interactions and infant cry patterns in the first 2 hours following delivery, the study was assessed to identify the barriers that the investigators had encountered in its planning and conduct. These barriers can be categorized as issues with (1) institutional review board approval, (2) participant recruitment and retention, (3) requirements for study personnel, (4) instrumentation, (5) potential observer and participant bias, and (6) budgeting. Each barrier is detailed, along with suggested solutions. It is hoped that that these experiences will be of value to other researchers, particularly those working in non-research-intensive institutions, as they gather data to contribute to the understanding of mother-infant interactions in the immediate postpartum period.

Identifying real and perceived barriers to therapeutic education programs for individuals with inflammatory arthritis.

PubMed

Bain, Lorna; Sangrar, Ruheena; Bornstein, Carolyn; Lukmanji, Sara; Hapuhennedige, Sandani; Thorne, Carter; Beattie, Karen A

2016-09-01

Therapeutic Education Programs (TEPs) grounded in self-management principles have been shown to improve quality of life of patients with chronic conditions and reduce patient-related healthcare costs. Though these programs are becoming more readily available, patients often experience barriers in participating. This study sought to identify barriers faced by inflammatory arthritis (IA) patients in attending a TEP and understand how patients overcame perceived barriers. A mixed-method study design was used. Questionnaires were distributed to individuals with IA who were invited to attend a TEP between 2010 and 2013. Respondents were those that chose not to attend (group A), individuals who attended ≤4 of 10 sessions (group B), individuals who attended ≥5 of 10 sessions prior to May 2013 (group C), and individuals who attended ≥5 of 10 sessions from June 2013 to November 2013 (group D). Individuals in group D were also invited to participate in focus groups to discuss how they had overcome perceived barriers. Real barriers identified by individuals in groups A and B included time, distance, and cost associated with attendance. Individuals who overcame perceived barriers (groups C and D) discussed strategies they used to do so. Aspects of the overall program experience and access to clinic and program also contributed to patients being able to overcome barriers. Time, distance, and cost are external barriers that prevented individuals from utilizing self-management education opportunities. These barriers were overcome if and when individuals had resources available to them. Readiness for behavior change also influenced commitment to participate in the program.

Breaking the BBC (Buoyancy Barriers to Cryovolcanism)

NASA Astrophysics Data System (ADS)

McGovern, P. J.; White, O. L.

2018-06-01

Like Australian table wines, Cryovolcanism has been poo-poohed, because of a perceived negative buoyancy problem. Here we point out that several basaltic planets have overcome far worse barriers, and calculate a scenario for cyrovolcanism on Pluto.

Exploring Linguistic Barriers to Help-Seeking Behaviors: The Lived Experiences of Chinese Undergraduate Students

ERIC Educational Resources Information Center

Hillis, Erin Rene

2017-01-01

First time college undergraduate students from China face linguistic and cultural barriers when seeking academic help from their faculty members, but there is little research addressing these students' experiences of encountering these barriers, nor how the barriers are overcome. This qualitative transcendental phenomenological study sought…

Conservation of direct dynamics in sterically hindered SN2/E2 reactions.

PubMed

Carrascosa, Eduardo; Meyer, Jennifer; Michaelsen, Tim; Stei, Martin; Wester, Roland

2018-01-21

Nucleophilic substitution (S N 2) and base-induced elimination (E2), two indispensable reactions in organic synthesis, are commonly assumed to proceed under stereospecific conditions. Understanding the way in which the reactants pre-orient in these reactions, that is its stereodynamics, is essential in order to achieve a detailed atomistic picture and control over such processes. Using crossed beam velocity map imaging, we study the effect of steric hindrance in reactions of Cl - and CN - with increasingly methylated alkyl iodides by monitoring the product ion energy and scattering angle. For both attacking anions the rebound mechanism, indicative of a direct S N 2 pathway, is found to contribute to the reaction at high relative collision energies despite being increasingly hindered. An additional forward scattering mechanism, ascribed to a direct E2 reaction, also contributes at these energies. Inspection of the product energy distributions confirms the direct and fast character of both mechanisms as opposed to an indirect reaction mechanism which leads to statistical energy redistribution in the reaction complex. This work demonstrates that nonstatistical dynamics and energetics govern S N 2 and E2 pathways even in sterically hindered exchange reaction systems.

Conservation of direct dynamics in sterically hindered SN2/E2 reactions

PubMed Central

Carrascosa, Eduardo; Meyer, Jennifer; Michaelsen, Tim; Stei, Martin

2017-01-01

Nucleophilic substitution (SN2) and base-induced elimination (E2), two indispensable reactions in organic synthesis, are commonly assumed to proceed under stereospecific conditions. Understanding the way in which the reactants pre-orient in these reactions, that is its stereodynamics, is essential in order to achieve a detailed atomistic picture and control over such processes. Using crossed beam velocity map imaging, we study the effect of steric hindrance in reactions of Cl– and CN– with increasingly methylated alkyl iodides by monitoring the product ion energy and scattering angle. For both attacking anions the rebound mechanism, indicative of a direct SN2 pathway, is found to contribute to the reaction at high relative collision energies despite being increasingly hindered. An additional forward scattering mechanism, ascribed to a direct E2 reaction, also contributes at these energies. Inspection of the product energy distributions confirms the direct and fast character of both mechanisms as opposed to an indirect reaction mechanism which leads to statistical energy redistribution in the reaction complex. This work demonstrates that nonstatistical dynamics and energetics govern SN2 and E2 pathways even in sterically hindered exchange reaction systems. PMID:29629138

Steric Shielding of Surface Epitopes and Impaired Immune Recognition Induced by the Ebola Virus Glycoprotein

PubMed Central

Francica, Joseph R.; Varela-Rohena, Angel; Medvec, Andrew; Plesa, Gabriela; Riley, James L.; Bates, Paul

2010-01-01

Many viruses alter expression of proteins on the surface of infected cells including molecules important for immune recognition, such as the major histocompatibility complex (MHC) class I and II molecules. Virus-induced downregulation of surface proteins has been observed to occur by a variety of mechanisms including impaired transcription, blocks to synthesis, and increased turnover. Viral infection or transient expression of the Ebola virus (EBOV) glycoprotein (GP) was previously shown to result in loss of staining of various host cell surface proteins including MHC1 and β1 integrin; however, the mechanism responsible for this effect has not been delineated. In the present study we demonstrate that EBOV GP does not decrease surface levels of β1 integrin or MHC1, but rather impedes recognition by steric occlusion of these proteins on the cell surface. Furthermore, steric occlusion also occurs for epitopes on the EBOV glycoprotein itself. The occluded epitopes in host proteins and EBOV GP can be revealed by removal of the surface subunit of GP or by removal of surface N- and O- linked glycans, resulting in increased surface staining by flow cytometry. Importantly, expression of EBOV GP impairs CD8 T-cell recognition of MHC1 on antigen presenting cells. Glycan-mediated steric shielding of host cell surface proteins by EBOV GP represents a novel mechanism for a virus to affect host cell function, thereby escaping immune detection. PMID:20844579

Restricted amide rotation with steric hindrance induced multiple conformations

NASA Astrophysics Data System (ADS)

Krishnan, V. V.; Vazquez, Salvador; Maitra, Kalyani; Maitra, Santanu

2017-12-01

The Csbnd N bond character is dependent directly upon the resonance-contributor structure population driven by the delocalized nitrogen lone-pair of electrons. In the case of N, N-dibenzyl-ortho-toluamide (o-DBET), the molecule adopts subpopulations of conformers with distinct NMR spectral features, particularly at low temperatures. This conformational adaptation is unique to o-DBET, while the corresponding meta- and para- forms do not show such behavior. Variable-temperature (VT) NMR, two-dimensional exchange spectroscopy (EXSY), and qualitative molecular modeling studies are used to demonstrate how multiple competing interactions such as restricted amide rotation and steric hindrance effects can lead to versatile molecular adaptations in the solution state.

Learning from the Best: Overcoming Barriers to Reforms-Based Elementary Science Teaching

ERIC Educational Resources Information Center

Banchi, Heather May

2009-01-01

This study explored the characteristics of elementary science teachers who employ reforms-based practices. Particular attention was paid to the consistency of teachers' practices and their beliefs, the impact of professional development experiences on practices, and how teachers mitigated barriers to reforms-based instruction. Understanding how…

Tailored interventions to overcome identified barriers to change: effects on professional practice and health care outcomes

PubMed Central

Baker, Richard; Camosso-Stefinovic, Janette; Gillies, Clare; Shaw, Elizabeth J; Cheater, Francine; Flottorp, Signe; Robertson, Noelle

2014-01-01

Background In the previous version of this review, the effectiveness of interventions tailored to barriers to change was found to be uncertain. Objectives To assess the effectiveness of interventions tailored to address identified barriers to change on professional practice or patient outcomes. Search methods For this update, in addition to the EPOC Register and pending files, we searched the following databases without language restrictions, from inception until August 2007: MEDLINE, EMBASE, CINAHL, BNI and HMIC. We searched the National Research Register to November 2007. We undertook further searches to October 2009 to identify potentially eligible published or ongoing trials. Selection criteria Randomised controlled trials (RCTs) of interventions tailored to address prospectively identified barriers to change that reported objectively measured professional practice or healthcare outcomes in which at least one group received an intervention designed to address prospectively identified barriers to change. Data collection and analysis Two reviewers independently assessed quality and extracted data. We undertook quantitative and qualitative analyses. The quantitative analyses had two elements. We carried out a meta-regression to compare interventions tailored to address identified barriers to change with either no interventions or an intervention(s) not tailored to the barriers.We carried out heterogeneity analyses to investigate sources of differences in the effectiveness of interventions. These included the effects of: risk of bias, concealment of allocation, rigour of barrier analysis, use of theory, complexity of interventions, and the reported presence of administrative constraints. Main results We included 26 studies comparing an intervention tailored to address identified barriers to change to no intervention or an intervention(s) not tailored to the barriers. The effect sizes of these studies varied both across and within studies. Twelve studies provided

Effect of Pendant Side-Chain Sterics and Dipole Forces on Short Range Ordering in Random Polyelectrolytes

NASA Astrophysics Data System (ADS)

Nwosu, Chinomso; Pandey, Tara; Herring, Andrew; Coughlin, Edward; University of Massachusetts, Amherst Collaboration; Colorado School of Mines Collaboration

Backbone-to-backbone spacing in polymers is known to be dictated by the length of the pendant side-chains. Dipole forces in random polyelectrolytes lead to ionic clusters with a characteristic spacing that can be observed by SAXS. Repulsion due to side-chain sterics will compete with dipole forces driving cluster formation in random polyelectrolytes. A model study on short range order in anion exchange membranes (AEMs) of quaternized P4VP-ran-PI is presented. Quaternization of P4VP with alkyl bromides having different numbers of carbons, CnBr, introduces pendant side-chains as well as charges. X-ray scattering performed on PQ4VP-ran-PI(CnBr) show that when n <5 the dipole forces dominate leading to the formation of ionic clusters. However, when n >4, the chains remain separated due to sterics, forming a distinct backbone-to-backbone spacing morphology. For n=3, both dipole clustering and backbone spacing can coexist. Crosslinking of the isoprene units increased the coexistence window from n=3 to n=6. Impedance measurements show that a maximum conductivity of 110mS/cm was obtained for PQ4VP-ran-PI(C3Br). A discussion on short range order due to competition, or counter balancing, of steric repulsion and dipole forces will be presented. US Army MURI project (W911NF1010520).

A Steric-inhibition model for regulation of nucleotide exchange via the Dock180 family of GEFs.

PubMed

Lu, Mingjian; Kinchen, Jason M; Rossman, Kent L; Grimsley, Cynthia; Hall, Matthew; Sondek, John; Hengartner, Michael O; Yajnik, Vijay; Ravichandran, Kodi S

2005-02-22

CDM (CED-5, Dock180, Myoblast city) family members have been recently identified as novel, evolutionarily conserved guanine nucleotide exchange factors (GEFs) for Rho-family GTPases . They regulate multiple processes, including embryonic development, cell migration, apoptotic-cell engulfment, tumor invasion, and HIV-1 infection, in diverse model systems . However, the mechanism(s) of regulation of CDM proteins has not been well understood. Here, our studies on the prototype member Dock180 reveal a steric-inhibition model for regulating the Dock180 family of GEFs. At basal state, the N-terminal SH3 domain of Dock180 binds to the distant catalytic Docker domain and negatively regulates the function of Dock180. Further studies revealed that the SH3:Docker interaction sterically blocks Rac access to the Docker domain. Interestingly, ELMO binding to the SH3 domain of Dock180 disrupted the SH3:Docker interaction, facilitated Rac access to the Docker domain, and contributed to the GEF activity of the Dock180/ELMO complex. Additional genetic rescue studies in C. elegans suggested that the regulation of the Docker-domain-mediated GEF activity by the SH3 domain and its adjoining region is evolutionarily conserved. This steric-inhibition model may be a general mechanism for regulating multiple SH3-domain-containing Dock180 family members and may have implications for a variety of biological processes.

Barriers to healthcare for transgender individuals.

PubMed

Safer, Joshua D; Coleman, Eli; Feldman, Jamie; Garofalo, Robert; Hembree, Wylie; Radix, Asa; Sevelius, Jae

2016-04-01

Transgender persons suffer significant health disparities and may require medical intervention as part of their care. The purpose of this manuscript is to briefly review the literature characterizing barriers to healthcare for transgender individuals and to propose research priorities to understand mechanisms of those barriers and interventions to overcome them. Current research emphasizes sexual minorities' self-report of barriers, rather than using direct methods. The biggest barrier to healthcare reported by transgender individuals is lack of access because of lack of providers who are sufficiently knowledgeable on the topic. Other barriers include: financial barriers, discrimination, lack of cultural competence by providers, health systems barriers, and socioeconomic barriers. National research priorities should include rigorous determination of the capacity of the US healthcare system to provide adequate care for transgender individuals. Studies should determine knowledge and biases of the medical workforce across the spectrum of medical training with regard to transgender medical care; adequacy of sufficient providers for the care required, larger social structural barriers, and status of a framework to pay for appropriate care. As well, studies should propose and validate potential solutions to address identified gaps.

Overcoming nanoscale friction barriers in transition metal dichalcogenides

NASA Astrophysics Data System (ADS)

Cammarata, Antonio; Polcar, Tomas

2017-08-01

We study the atomic contributions to the nanoscale friction in layered M X2 (M =Mo , W; X =S , Se, Te) transition metal dichalcogenides by combining ab initio techniques with group-theoretical analysis. Starting from stable atomic configurations, we propose a computational method, named normal-modes transition approximation (NMTA), to individuate possible sliding paths from only the analysis of the phonon modes of the stable geometry. The method provides a way to decompose the atomic displacements realizing the layer sliding in terms of phonon modes of the stable structure, so as to guide the selection and tuning of specific atomic motions promoting M X2 sheets gliding, and to adjust the corresponding energy barrier. The present results show that main contributions to the nanoscale friction are due to few low frequency phonon modes, corresponding to rigid shifts of M X2 layers. We also provide further evidences that a previously reported Ti-doped MoS2 phase is a promising candidate as new material with enhanced tribologic properties. The NMTA approach can be exploited to tune the energetic and the structural features of specific phonon modes, and, thanks to its general formulation, can also be applied to any solid state system, irrespective of the chemical composition and structural topology.

Overcoming the barriers to effective treatment for attention-deficit/hyperactivity disorder: a neuro-educational approach.

PubMed

Monastra, Vincent J

2005-10-01

Despite specific diagnostic criteria, published practice guidelines for assessing patients, and the availability of effective pharmacological treatments for children diagnosed with attention-deficit/hyperactivity disorder (AD/HD), a review of prescription practices in the United States indicates that as few as 25-50% of these patients receive even minimal medical treatment for this condition. Because untreated children with AD/HD are at increased risk for psychoactive substance abuse, criminal behavior, and other social problems as adults, the provision of effective care during childhood is essential. In order to clarify the factors impeding treatment during childhood and develop a targeted intervention to overcome these barriers, two studies involving 1514 families were conducted. Each family included one child diagnosed with AD/HD. Factors associated with treatment failure or non-compliance with medical advice included: dissatisfaction with a diagnostic process limited to brief observation, interview, and review of behavior rating scales; fear of stimulant medication; lack of medication response within the first month; development of side-effects during the first month; lack of understanding of the reasons stimulants were being prescribed for a child, and insufficient clinical response. Based on these findings, an intervention program consisting of a comprehensive evaluation process (that included neuropsychological and neurophysiological tests of attention, and medical screening for other health problems associated with inattention and hyperactivity) and parent education about the medical causes of AD/HD, the biochemical action of medications, the relationship between dietary habits and attention, and the educational rights of children with AD/HD was conducted. Following completion of this three session intervention, 95% of patients complied with medical recommendations, initiated pharmacological treatment, and continued medication for a 2-year follow-up period

Cancer chemoprevention and cancer preventive vaccines--a call to action: leaders of diverse stakeholder groups present strategies for overcoming multiple barriers to meet an urgent need.

PubMed

Herberman, Ronald B; Pearce, Homer L; Lippman, Scott M; Pyenson, Bruce S; Alberts, David S

2006-12-15

The emerging field of cancer prevention through chemoprevention agents and cancer vaccines offers significant promise for reducing suffering and death from cancer. However, that promise may not be kept unless major barriers to progress are lowered or eliminated. Among the most significant barriers are the relatively small investment from government and industry in research and development of cancer preventive agents; a predominant emphasis of translational cancer research on therapeutic interventions for metastatic or advanced cancer; complexities of prevention trial design; a relatively uncharted Food and Drug Administration (FDA) approval process for preventive agents; insufficient public and patient understanding of the importance and potential for cancer preventive measures, with consequent unpredictable public and patient willingness to take preventive agents; an uncertain reimbursement from payors; and limitations in patent law, liability protection, and data package exclusivity that undermine the opportunity for recouping investment. Viewed individually or collectively, each of these barriers serves as a substantial deterrent to intellectual and financial investment by all sectors of the cancer community. In an effort to ultimately overcome these barriers, a Cancer Prevention Research Summit was assembled June 12-13, 2006 in Bethesda, Maryland, organized by C-Change with support from the AACR. The Summit brought together some 120 leaders from private, public, and not-for-profit entities, including cancer researchers and clinicians; federal health officials; regulatory agency representatives; pharmaceutical, biotech, and food industry leaders; patent attorneys; economists; public and private provider group executives; and advocates. Participants engaged in a detailed process to more carefully define the major barriers, identify potential solutions, and formulate initial priorities and recommendations for action. At the conclusion of this dialogue among

Stepwise DNA Methylation Changes Are Linked to Escape from Defined Proliferation Barriers and Mammary Epithelial Cell Immortalization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novak, Petr; Jensen, Taylor J.; Garbe, James C.

The timing and progression of DNA methylation changes during carcinogenesis are not completely understood. To develop a timeline of aberrant DNA methylation events during malignant transformation, we analyzed genome-wide DNA methylation patterns in an isogenic human mammary epithelial cell (HMEC) culture model of transformation. To acquire immortality and malignancy, the cultured finite lifespan HMEC must overcome two distinct proliferation barriers. The first barrier, stasis, is mediated by the retinoblastoma protein and can be overcome by loss of p16(INK4A) expression. HMEC that escape stasis and continue to proliferate become genomically unstable before encountering a second more stringent proliferation barrier, telomere dysfunctionmore » due to telomere attrition. Rare cells that acquire telomerase expression may escape this barrier, become immortal, and develop further malignant properties. Our analysis of HMEC transitioning from finite lifespan to malignantly transformed showed that aberrant DNA methylation changes occur in a stepwise fashion early in the transformation process. The first aberrant DNA methylation step coincides with overcoming stasis, and results in few to hundreds of changes, depending on how stasis was overcome. A second step coincides with immortalization and results in hundreds of additional DNA methylation changes regardless of the immortalization pathway. A majority of these DNA methylation changes are also found in malignant breast cancer cells. These results show that large-scale epigenetic remodeling occurs in the earliest steps of mammary carcinogenesis, temporally links DNA methylation changes and overcoming cellular proliferation barriers, and provides a bank of potential epigenetic biomarkers that mayprove useful in breast cancer risk assessment.« less

Using self-efficacy theory to develop interventions that help older people overcome psychological barriers to physical activity: a discussion paper.

PubMed

Lee, Ling-Ling; Arthur, Antony; Avis, Mark

2008-11-01

Only a fifth of older people undertake a level of physical activity sufficient to lead to health benefit. Misconceptions about the ageing process and beliefs about the costs and benefits of exercise in late life may result in unnecessary self-imposed activity restriction. Thus, adhering to a physical activity can be difficult particularly when the benefits of exercise are often not immediate. Many of the barriers to engaging in physical activity among older people are attitudinal. It is therefore important to take account of the non-physical aspects of physical activity intervention programmes, such as increasing confidence. Self-efficacy is a widely applied theory used to understand health behaviour and facilitate behavioural modification, such as the increase of physical activity. This paper aims to examine the ways in which self-efficacy theory might be used in intervention programmes designed to overcome psychological barriers for increasing physical activity among older people. A number of studies have demonstrated that exercise self-efficacy is strongly associated with the amount of physical activity undertaken. Evidence from some trials supports the view that incorporating the theory of self-efficacy into the design of a physical activity intervention is beneficial. Physical activity interventions aimed at improving the self perception of exercise self-efficacy can have positive effects on confidence and the ability to initiate and maintain physical activity behaviour. There are a number of ways for nurses to facilitate older people to draw on the four information sources of self-efficacy: performance accomplishments, vicarious learning, verbal encouragement, and physiological and affective states. Research challenges that future studies need to address include the generalisability of exercise setting, the role of age as an effect modifier, and the need for more explicit reporting of how self-efficacy is operationalised in interventions.

Expertise, Time, Money, Mentoring, and Reward: Systemic Barriers That Limit Education Researcher Productivity-Proceedings From the AAMC GEA Workshop.

PubMed

Yarris, Lalena M; Juve, Amy Miller; Artino, Anthony R; Sullivan, Gail M; Rougas, Steven; Joyce, Barbara; Eva, Kevin

2014-09-01

To further evolve in an evidence-based fashion, medical education needs to develop and evaluate new practices for teaching, learning, and assessment. However, educators face barriers in designing, conducting, and publishing education research. To explore the barriers medical educators face in formulating, conducting, and publishing high-quality medical education research, and to identify strategies for overcoming them. A consensus workshop was held November 5, 2013, at the Association of American Medical Colleges annual meeting. A working group of education research experts and educators completed a preconference literature review focusing on barriers to education research. During the workshop, consensus-based and small group techniques were used to refine the broad themes into content categories. Attendees then ranked the most important barriers and strategies for overcoming them with the highest potential impact. Barriers participants faced in conducting quality education research included lack of (1) expertise, (2) time, (3) funding, (4) mentorship, and (5) reward. The strategy considered most effective in overcoming these barriers involved building communities of education researchers for collaboration and networking, and advocating for education researchers' interests. Other suggestions included trying to secure increased funding opportunities, developing mentoring programs, and encouraging mechanisms to ensure protected time. Barriers to education research productivity clearly exist. Many appear to result from feelings of isolation that may be overcome with systemic efforts to develop and enable communities of practice across institutions. Finally, the theme of "reward" is novel and complex and may have implications for education research productivity.

Barriers to overcome for effective cancer control in Africa.

PubMed

Harford, Joe B

2015-08-01

Cancer control in Africa is complicated due to large differences in cancer incidence between countries caused by differences in exposure to known risk factors. For example, substantial differences are seen when selected cancers in north Africa are compared with those in sub-Saharan Africa. In the future, population growth and demographic shifts are likely to have profound effects on the prevalence of cancer across the continent. Likewise, many factors outside of health care such as language differences, conflict, and poverty can affect cancer control efforts. Although cooperation in cancer control efforts is desirable, differences in cultural and geopolitical factors that characterise African countries and their populations, together with the sheer size of the continent, present unique challenges to effective cancer control. This Series paper discusses factors related to the size, diversity, and conditions within Africa that present barriers to optimal collaboration in cancer control efforts across the continent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Overcoming barriers to the use of osteopathic manipulation techniques in the emergency department.

PubMed

Roberge, Raymond J; Roberge, Marc R

2009-08-01

Osteopathic Manipulation Techniques (OMT) have been shown to be effective therapeutic modalities in various clinical settings, but appear to be underutilized in the emergency department (ED) setting. To examine barriers to the use of OMT in the ED and provide suggestions to ameliorate these barriers. Literature review While the medical literature cites numerous obstacles to the use of OMT in the ED setting, most can be positively addressed through education, careful planning, and ongoing research into use of these techniques. Recent prospective clinical trials of OMT have demonstrated the utility of these modalities. Osteopathic Manipulation Techniques are useful therapeutic modalities that could be utilized to a greater degree in the ED. As the number of osteopathic emergency physicians increases, the opportunity to employ these techniques should increase.

Planning and Implementing Immunization Billing Programs at State and Local Health Departments: Barriers and Possible Solutions.

PubMed

Corriero, Rosemary; Redmon, Ginger

Before participating in a project funded by the Centers for Disease Control and Prevention, most state and local health departments (LHDs) were not seeking reimbursement or being fully reimbursed by insurance plans for the cost of immunization services (including vaccine costs and administration fees) they provided to insured patients. Centers for Disease Control and Prevention's Billables Project was designed to enable state and LHDs to bill public and private insurance plans for immunization services provided to insured patients. Identify and describe key barriers state and LHDs may encounter while planning and implementing a billing program, as well as possible solutions for overcoming those barriers. This study used reports from Billables Project participants to explore barriers they encountered when planning and implementing a billing program and steps taken to address those barriers. Thirty-eight state immunization programs. Based on project participants' reports, barriers were noted in 7 categories: (1) funding and costs, (2) staff, (3) health department characteristics, (4) third-party payers and insurance plans, (5) software, (6) patient insurance status, and (7) other barriers. Possible solutions for overcoming those barriers included hiring or seeking external help, creating billing guides and training modules, streamlining workflows, and modifying existing software systems. Overcoming barriers during planning and implementation of a billing program can be challenging for state and LHDs, but the experiences and suggestions of past Billables Project participants can help guide future billing program efforts.

β-Octabromo- and β-Octakis(trifluoromethyl)isocorroles: New Sterically Constrained Macrocyclic Ligands

DOE PAGES

Thomas, Kolle E.; Beavers, Christine M.; Gagnon, Kevin J.; ...

2017-05-26

Here, we present a study of the acid-induced demetalation of two sterically hindered copper corroles, Cu β-octabromo-meso-triphenylcorrole (Cu[Br 8TPC]) and β-octakis(trifluoromethyl)-meso-tris(p-methoxyphenyl)corrole (Cu[(CF 3) 8TpOMePC]). Unlike reductive demetalation, which affords the free-base β-octabromocorrole, demetalation of Cu[Br 8TPC] under non- reductive conditions (CHCl 3/H 2SO 4) resulted in moderate yields of free-base 5- and 10-hydroxy isocorroles. The isomeric free bases could be complexed to Co II and Ni II, affording stable complexes. Only reductive demetalation was found to work for Cu[(CF 3) 8TpOMePC], affording a highly saddled, hydrated corrole, H 3[5-OH,10-H-(CF 3) 8TpOMePC], where the elements of water had added across C5more » and C10. Interaction of this novel free base with Co II resulted in Co[iso-10-H-[CF 3) 8TpOMePC], a Co II 10-hydro isocorrole. Finally, the new metal complexes were all characterized by single-crystal X-ray diffraction analysis and, despite their sterically hindered nature, were found to exhibit almost perfectly planar isocorrole cores.« less

ENA study cites barriers to NPSG compliance.

PubMed

2009-04-01

There are many barriers to compliance with the National Patient Safety Goals, as a recent study shows. However, emergency medicine experts say there are several strategies you can adopt to help overcome those barriers. Send the right message to your staff by establishing a culture of shared responsibility for safety. Establish scripts for talking with patients. Standardization will help ensure they are getting the correct information. Put standardized abbreviations on posters in your department, and list them on your medication reconciliation form.

Disease management in Canada: surmounting barriers to adoption.

PubMed

Gallant, Christopher R; MacKinnon, Neil J; Sprague, Denise A

2007-01-01

Disease Management (DM) programs are used to optimize economic outcomes and improve patient outcomes. Despite this, relative to the United States, Canadian health care organizations have been slow to adopt them. The objective of this article is to examine the concept of DM programs, the existing evidence to support their use and the barriers to their adoption in Canada. Several solutions aimed at overcoming the barriers to DM in Canada are proposed.

Barrier mechanism of multilayers graphene coated copper against atomic oxygen irradiation

NASA Astrophysics Data System (ADS)

Zhang, Haijing; Ren, Siming; Pu, Jibin; Xue, Qunji

2018-06-01

Graphene has been demonstrated as a protective coating for Cu under ambient condition because of its high impermeability and light-weight oxidation barrier. However, it lacks the research of graphene as a protective coating in space environment. Here, we experimentally and theoretically study the oxidation behavior of graphene-coated Cu in vacuum atomic oxygen (AO) condition. After AO irradiation, the experimental results show multilayer graphene has better anti-oxidation than monolayer graphene. Meanwhile, the calculation results show the oxidation appeared on the graphene's grain boundaries or the film's vacancy defects for the monolayer graphene coated Cu foil. Moreover, the calculation results show the oxidation process proceeds slowly in multilayers because of the matched defects overlaps each other to form a steric hindrance to suppress the O atom diffusion in the vertical direction, and the mismatched defects generates potential energy barriers for interlayer to suppress the O atom diffusion in the horizontal direction. Hence, multilayer graphene films could serve as protection coatings to prevent diffusion of O atom.

Barriers vs Creativity in Translator Training

ERIC Educational Resources Information Center

Yazici, Mine

2016-01-01

This paper discusses translation problems awaiting Turkish students as well as the creative solutions they develop in overcoming them. It consists of two parts; The first part studies the barriers concerning translation procedures from the perspective of translation theory and Turkish translation history; The second parts analyses the impact of…

Overcoming Barriers to the Use of Osteopathic Manipulation Techniques in the Emergency Department

PubMed Central

Roberge, Raymond J.; Roberge, Marc R.

2009-01-01

Background: Osteopathic Manipulation Techniques (OMT) have been shown to be effective therapeutic modalities in various clinical settings, but appear to be underutilized in the emergency department (ED) setting. Objective: To examine barriers to the use of OMT in the ED and provide suggestions to ameliorate these barriers. Methods: Literature review Results: While the medical literature cites numerous obstacles to the use of OMT in the ED setting, most can be positively addressed through education, careful planning, and ongoing research into use of these techniques. Recent prospective clinical trials of OMT have demonstrated the utility of these modalities. Conclusion: Osteopathic Manipulation Techniques are useful therapeutic modalities that could be utilized to a greater degree in the ED. As the number of osteopathic emergency physicians increases, the opportunity to employ these techniques should increase. PMID:19718381

Development of the Motivators of and Barriers to Health-Smart Behaviors Inventory

ERIC Educational Resources Information Center

Tucker, Carolyn M.; Rice, Kenneth G.; Hou, Wei; Kaye, Lillian B.; Nolan, Sarah E. M.; Grandoit, Delphia J.; Gonzales, Lucia; Smith, Mary B.; Desmond, Frederic F.

2011-01-01

The Motivators of and Barriers to Health-Smart Behaviors Inventory (MB-HSBI) was developed for use in identifying self-reported motivators of and barriers to the following health-promoting behaviors (called "health-smart behaviors") that should occur daily to help promote health and overcome illnesses/diseases: eating a healthy…

Overcoming barriers to HIV testing: preferences for new strategies among clients of a needle exchange, a sexually transmitted disease clinic, and sex venues for men who have sex with men.

PubMed

Spielberg, Freya; Branson, Bernard M; Goldbaum, Gary M; Lockhart, David; Kurth, Ann; Celum, Connie L; Rossini, Anthony; Critchlow, Cathy W; Wood, Robert W

2003-03-01

To determine strategies to overcome barriers to HIV testing among persons at risk. We developed a survey that elicited testing motivators, barriers, and preferences for new strategies among 460 participants at a needle exchange, three sex venues for men who have sex with men, and a sexually transmitted disease clinic. Barriers to testing included factors influenced by individual concern (fear and discrimination); by programs, policies, and laws (named reporting and inability to afford treatment); and by counseling and testing strategies (dislike of counseling, anxiety waiting for results, and venipuncture). The largest proportions of participants preferred rapid testing strategies, including clinic-based testing (27%) and home self-testing (20%); roughly equal proportions preferred oral fluid testing (18%), urine testing (17%), and standard blood testing (17%). One percent preferred home specimen collection. Participants who had never tested before were significantly more likely to prefer home self-testing compared with other strategies. Blacks were significantly more likely to prefer urine testing. Strategies for improving acceptance of HIV counseling and testing include information about access to anonymous testing and early treatment. Expanding options for rapid testing, urine testing, and home self-testing; providing alternatives to venipuncture; making pretest counseling optional; and allowing telephone results disclosure may encourage more persons to learn their HIV status.

Barriers to exotic weed management

Treesearch

Faith T. Campbell

1998-01-01

In order to increase effective efforts to reduce the impacts of invasive alien plant species· on our natural areas, we must overcome numerous barriers. Some of these are technical in nature, e.g., determining the most appropriate control method for a specific species in a particular ecosystem, or devising a better program to exclude new invasive plant species from our...

Oculocutaneous albinism: identifying and overcoming barriers to vision care in a Nigerian population.

PubMed

Udeh, N N; Eze, B I; Onwubiko, S N; Arinze, O C; Onwasigwe, E N; Umeh, R E

2014-06-01

To assess eye care service utilization, and identify access barriers in a south-eastern Nigerian albino population. The study was a population-based, cross-sectional survey conducted in Enugu state between August, 2011 and January, 2012. Using the data base of the state's Albino Foundation and tailored awareness creation, persons living with albinism were identified and recruited at two study centres. Data on participants' socio-demographics, perception of vision, visual needs, previous eye examination and or low vision assessment, use of glasses or low vision devices were collected. Reasons for non-utilisation of available vision care services were also obtained. Descriptive and comparative statistics were performed. A p < 0.05 was considered statistically significant. The participants (n = 153; males 70; females 83; sex ratio: 1:1.1) were aged 23.46 + 10.44 SD years (range 6-60 years). Most--95.4 % of the participants had no previous low vision assessment and none--0.0% had used low vision device. Of the participants, 82.4% reported previous eye examination, 33.3% had not used spectacles previously, despite the existing need. Ignorance--88.9% and poor access--8.5% were the main barriers to uptake of vision care services. In Enugu, Nigeria, there is poor awareness and low utilization of vision care services among people with albinism. The identified barriers to vision care access are amenable to awareness creation and logistic change in the provision of appropriate vision care services.

Experimental verification of the steric-entropic mode of retention in centrifugal field-flow fractionation using illite clay plates.

PubMed

Tadjiki, Soheyl; Beckett, Ronald

2018-02-23

The commonly used theory to describe the normal Brownian mode of field-flow fractionation (FFF) assumes the particles to be point masses and hence the shape is ignored. Beckett and Giddings extended this theory to include the effect of thin rods and discs being forced very close to the accumulation wall. By including the decrease in the entropy this causes, they derived new expressions for the retention of such nonspherical particles in FFF. The steric-entropic theory predicts that when the sample cloud thickness is less than the major dimension of the rods or discs then particles elute earlier than predicted by the Brownian mode theory. This leads to an underestimation of the buoyant mass and equivalent spherical diameter calculated from FFF data. In this paper we report for the first time experimental data for the retention of thin illite particles in centrifugal FFF that agrees well with these steric-entropic predictions. Not only do the size distributions calculated using the Brownian mode theory shift to lower size when the field is increased but the shift in the retention ratio of the peak maxima of the FFF fractograms could be predicted fairly accurately by the steric-entropic equations. Copyright © 2018 Elsevier B.V. All rights reserved.

The importance of reproductive barriers and the effect of allopolyploidization on crop breeding

PubMed Central

Tonosaki, Kaoru; Osabe, Kenji; Kawanabe, Takahiro; Fujimoto, Ryo

2016-01-01

Inter-specific hybrids are a useful source for increasing genetic diversity. Some reproductive barriers before and/or after fertilization prevent production of hybrid plants by inter-specific crossing. Therefore, techniques to overcome the reproductive barrier have been developed, and have contributed to hybridization breeding. In recent studies, identification of molecules involved in plant reproduction has been studied to understand the mechanisms of reproductive barriers. Revealing the molecular mechanisms of reproductive barriers may allow us to overcome reproductive barriers in inter-specific crossing, and to efficiently produce inter-specific hybrids in cross-combinations that cannot be produced through artificial techniques. Inter-specific hybrid plants can potentially serve as an elite material for plant breeding, produced through the merging of genomes of parental species by allopolyploidization. Allopolyploidization provides some benefits, such as heterosis, increased genetic diversity and phenotypic variability, which are caused by dynamic changes of the genome and epigenome. Understanding of allopolyploidization mechanisms is important for practical utilization of inter-specific hybrids as a breeding material. This review discusses the importance of reproductive barriers and the effect of allopolyploidization in crop breeding programs. PMID:27436943

Overcoming access barriers to health services through membership-based microfinance organizations: a review of evidence from South Asia

PubMed Central

Saha, Somen; Annear, Peter Leslie

2015-01-01

It is a challenge for the poor to overcome the barriers to accessing health services. Membership-based microfinance with associated health programmes can improve health outcomes for the poor. This study reviewed the evidence published between 1993 and 2013 on the role of membership-based microfinance with associated health programmes in improving health outcomes for the poor in South Asia. A total of 661 papers were identified and 26 selected for inclusion, based on the relevance and rigour of the research methods. Of these 26, five were evidence reviews. Of the remaining 21 papers, 12 were from India, seven from Bangladesh, and one each from Sri Lanka and Indonesia. Three papers addressed more than one theme. Five key themes emerged from the review: (i) the impact of microfinance programmes on the social and economic situation of the poor; (ii) the impact of microfinance programmes on community health; (iii) the impact of integrated microfinance health programmes on raising client awareness; (iv) the impact of integrated microfinance health programmes on financing health care; and (v) the impact of integrated microfinance health programmes on affordable health-care products and services. The review provides new evidence on the pathways through which microfinance helps to improve population health and value for money for such programmes. Among countries with large populations in the informal sector, there is a strong case for policy-makers to support these groups in providing access to life-saving health care among the poor. PMID:25685728

Barriers and Strategies for Success for American Indian College Students: A Review

ERIC Educational Resources Information Center

Keith, Jill F.; Stastny, Sherri N.; Brunt, Ardith

2016-01-01

American Indian and Alaska Native students have a significantly lower college graduation rate than that of other ethnic groups in the United States. These students often face a variety of barriers to the completion of their education. Overcoming barriers for the achievement of an advanced education takes commitment, hard work, and dedication on…

Targeting Brain Tumors with Nanomedicines: Overcoming Challenges of Blood Brain Barrier.

PubMed

Ningaraj, Nagendra S; Reddy, Polluru L; Khaitan, Divya

2018-04-12

This review elucidates ongoing research, which show improved delivery of anticancer drugs alone and/ or enclosed in carriers collectively called nanomedicines to cross the Blood brain barrier (BBB) / blood-brain tumor barrier (BTB) to kill tumor cells and impact patient survival. We highlighted various advances in understanding the mechanism of BTB function that impact on anticancer therapeutics delivery. We discussed latest breakthroughs in developing pharmaceutical strategies, including nanomedicines and delivering them across BTB for brain tumor management and treatment. We highlight various studies on regulation of BTB permeability regulation with respect to nanotech-based nanomedicines for targeted treatment of brain tumors. We have reviewed latest literature on development of specialized molecules and nanospheres for carrying pay load of anticancer agents to brain tumor cells across the BBB/ BTB and avoid drug efflux systems. We discuss identification and development of distinctive BTB biomarkers for targeted anti-cancer drug delivery to brain tumors. In addition, we discussed nanomedicines and multimeric molecular therapeutics that were encapsulated in nanospheres for treatment and monitoring of brain tumors. In this context, we highlight our research on calcium-activated potassium channels (KCa) and ATP-sensitive potassium channels (KATP) as portals of enhanced antineoplastic drugs delivery. This review might interest both academic and drug company scientists involved in drug delivery to brain tumors. We further seek to present evidence that BTB modulators can be clinically developed as combination drug or/ and as stand-alone anticancer drugs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Barriers to Successful Implementation of Technology Integration in Educational Settings: A Case Study

ERIC Educational Resources Information Center

Laferrière, T.; Hamel, C.; Searson, M.

2013-01-01

Representing issues discussed at the EduSummIT 2011 relative to essential conditions and barriers to successful technology integration, this article presents a systemic analysis of barriers that needed to be overcome for an information technology initiative (Remote Networked School project) to be successfully implemented. The analysis was…

Overcoming barriers in care for the dying: Theoretical analysis of an innovative program model.

PubMed

Wallace, Cara L

2016-08-01

This article explores barriers to end-of-life (EOL) care (including development of a death denying culture, ongoing perceptions about EOL care, poor communication, delayed access, and benefit restrictions) through the theoretical lens of symbolic interactionism (SI), and applies general systems theory (GST) to a promising practice model appropriate for addressing these barriers. The Compassionate Care program is a practice model designed to bridge gaps in care for the dying and is one example of a program offering concurrent care, a recent focus of evaluation though the Affordable Care Act. Concurrent care involves offering curative care alongside palliative or hospice care. Additionally, the program offers comprehensive case management and online resources to enrollees in a national health plan (Spettell et al., 2009).SI and GST are compatible and interrelated theories that provide a relevant picture of barriers to end-of-life care and a practice model that might evoke change among multiple levels of systems. These theories promote insight into current challenges in EOL care, as well as point to areas of needed research and interventions to address them. The article concludes with implications for policy and practice, and discusses the important role of social work in impacting change within EOL care.

Overcoming barriers to treating iron overload in patients with lower-risk myelodysplastic syndrome.

PubMed

Zeidan, Amer M; Pullarkat, Vinod A; Komrokji, Rami S

2017-09-01

Myelodysplastic syndromes (MDS) constitute a group of heterogeneous hematopoietic neoplasms characterized by ineffective erythropoiesis, anemia, and/or cytopenias. Supportive care for patients with MDS involves frequent red blood cell transfusions, which places patients with ongoing transfusional dependence (TD) at risk for iron overload (IO). Development of IO and tissue iron deposition can increase the risk of cardiac, hepatic, and endocrine toxicities, infection, and progression to acute myeloid leukemia. Iron chelation therapy (ICT) is an option for lower-risk MDS patients to reduce their degree of IO and possibly improve survival; use of these agents in thalassemia patients with TD and IO has been associated with reduced IO-associated complications and better survival. At present, there are several barriers to the regular use of ICT, such as a lack of randomized trial evidence and consistent guidance on diagnosis of IO and when to implement ICT, as well as barriers in adherence to/tolerability of ICT. Copyright © 2017 Elsevier B.V. All rights reserved.

Overcoming barriers to a research-ready national commercial claims database.

PubMed

Newman, David; Herrera, Carolina-Nicole; Parente, Stephen T

2014-11-01

Billions of dollars have been spent on the goal of making healthcare data available to clinicians and researchers in the hopes of improving healthcare and lowering costs. However, the problems of data governance, distribution, and accessibility remain challenges for the healthcare system to overcome. In this study, we discuss some of the issues around holding, reporting, and distributing data, including the newest "big data" challenge: making the data accessible to researchers and policy makers. This article presents a case study in "big healthcare data" involving the Health Care Cost Institute (HCCI). HCCI is a nonprofit, nonpartisan, independent research institute that serves as a voluntary repository of national commercial healthcare claims data. Governance of large healthcare databases is complicated by the data-holding model and further complicated by issues related to distribution to research teams. For multi-payer healthcare claims databases, the 2 most common models of data holding (mandatory and voluntary) have different data security requirements. Furthermore, data transport and accessibility may require technological investment. HCCI's efforts offer insights from which other data managers and healthcare leaders may benefit when contemplating a data collaborative.

Behavioral training and AIDS risk reduction: overcoming barriers to condom use.

PubMed

Weisse, C S; Turbiasz, A A; Whitney, D J

1995-02-01

To assess the short- and long-term effects of an AIDS-prevention workshop on undergraduates' attitudes about condom use and AIDS, 31 participants and 31 controls were studied immediately after training sessions as well as three months later. The workshop was aimed at reducing embarrassment to purchase condoms, encouraging positive attitudes about condoms, and promoting knowledge about AIDS. To help students overcome their embarrassment over condom purchases, a behavioral intervention was included allowing students to make condom purchases at nearby drug stores. Results revealed that participants reported less embarrassment over condom purchases after training sessions and that this effect became even stronger over time. Knowledge about AIDS and positive attitudes about condoms also increased immediately after the workshop, but these changes did not persist. Results suggest that AIDS prevention workshops may lead to transient changes unless a specific skill (i.e., condom purchasing) is targeted via behavioral training.

Overcoming Barriers between Volunteer Professionals Advising Project-Based Learning Teams with Regulation Tools

ERIC Educational Resources Information Center

Rees Lewis, Daniel G.; Easterday, Matthew W.; Harburg, Emily; Gerber, Elizabeth M.; Riesbeck, Christopher K.

2018-01-01

To provide the substantial support required for project-based learning (PBL), educators can incorporate professional experts as "design coaches." However, previous work shows barriers incorporating design coaches who can rarely meet face-to-face: (1) communication online is time-consuming, (2) updating coaches online is not perceived as…

Steric sea level variability (1993-2010) in an ensemble of ocean reanalyses and objective analyses

NASA Astrophysics Data System (ADS)

Storto, Andrea; Masina, Simona; Balmaseda, Magdalena; Guinehut, Stéphanie; Xue, Yan; Szekely, Tanguy; Fukumori, Ichiro; Forget, Gael; Chang, You-Soon; Good, Simon A.; Köhl, Armin; Vernieres, Guillaume; Ferry, Nicolas; Peterson, K. Andrew; Behringer, David; Ishii, Masayoshi; Masuda, Shuhei; Fujii, Yosuke; Toyoda, Takahiro; Yin, Yonghong; Valdivieso, Maria; Barnier, Bernard; Boyer, Tim; Lee, Tony; Gourrion, Jérome; Wang, Ou; Heimback, Patrick; Rosati, Anthony; Kovach, Robin; Hernandez, Fabrice; Martin, Matthew J.; Kamachi, Masafumi; Kuragano, Tsurane; Mogensen, Kristian; Alves, Oscar; Haines, Keith; Wang, Xiaochun

2017-08-01

Quantifying the effect of the seawater density changes on sea level variability is of crucial importance for climate change studies, as the sea level cumulative rise can be regarded as both an important climate change indicator and a possible danger for human activities in coastal areas. In this work, as part of the Ocean Reanalysis Intercomparison Project, the global and regional steric sea level changes are estimated and compared from an ensemble of 16 ocean reanalyses and 4 objective analyses. These estimates are initially compared with a satellite-derived (altimetry minus gravimetry) dataset for a short period (2003-2010). The ensemble mean exhibits a significant high correlation at both global and regional scale, and the ensemble of ocean reanalyses outperforms that of objective analyses, in particular in the Southern Ocean. The reanalysis ensemble mean thus represents a valuable tool for further analyses, although large uncertainties remain for the inter-annual trends. Within the extended intercomparison period that spans the altimetry era (1993-2010), we find that the ensemble of reanalyses and objective analyses are in good agreement, and both detect a trend of the global steric sea level of 1.0 and 1.1 ± 0.05 mm/year, respectively. However, the spread among the products of the halosteric component trend exceeds the mean trend itself, questioning the reliability of its estimate. This is related to the scarcity of salinity observations before the Argo era. Furthermore, the impact of deep ocean layers is non-negligible on the steric sea level variability (22 and 12 % for the layers below 700 and 1500 m of depth, respectively), although the small deep ocean trends are not significant with respect to the products spread.

The effect of a walking program on perceived benefits and barriers to exercise in postmenopausal African American women.

PubMed

Williams, Bernadette R; Bezner, Janet; Chesbro, Steven B; Leavitt, Ronnie

2006-01-01

Rates of exercise participation among African Americans is low. Identifying and overcoming perceived benefits/ barriers unique to African American women (AAW) may increase their exercise participation. The purpose of this study was to describe perceived benefits/barriers to exercise in AAW before and after participation in a walking program. Thirty-five postmenopausal AAW participated in a 7-week structured walking program with 2 walking goals. Perceived benefits and barriers to exercise were assessed using the Exercise Benefits/Barriers Scale at the beginning and end of the program. Participants engaged in a postintervention interview to further assess benefits/barriers to exercise participation. Perceived benefits/barriers to exercise did not change significantly with participation in a walking program. Lack of time due to work and family responsibilities affected achievement of the brisk walking goal. Postmenopausal AAW in this study strongly believed in the benefits of exercising and had increased levels of participation in a walking program when lack of time was not a barrier. Overcoming this barrier is the true challenge to health care professionals.

Influence of steric hindrance on enantioseparation of Dns-amino acids and pesticides on terguride based chiral selectors in capillary electrophoresis.

PubMed

Honzátko, Ales; Cvak, Jan; Vaingátová, Silvie; Flieger, Miroslav

2005-05-01

Three urea derivatives of ergoline-based chiral selectors (CSs), differing in the size of the urea side chain, i.e. dimethyl- (CSI), diethyl- (CSII), and diisopropylurea (CSIII), were used to study the effect of steric hindrance on the enantioseparation of dansyl amino acids (Dns-AAs), pesticides, and mandelic acid under condition of capillary electrophoresis (CE) in linear polyacrylamide coated capillaries. A mixture of organic modifiers (MeOH/THF, 4:1 v/v) in a BGE consisting of 100 mM beta-alanine-acetate was used to increase the solubility of CSs up to 25 mM. The capillary was filled with CS (high UV absorption), and the inlet and outlet vials contained buffer solutions only. The best enantioseparation of Dns-AAs was achieved on CSI. Increased steric hindrance of the chiral binding site led to reduction of both enantioselectivity and resolution. The opposite pattern was observed for the separation of mandelic acid enantiomers, where the best enantioseparation and resolution was obtained with CSIII. Most of the pesticides studied reached maximum selectivity on the diethylurea ergoline derivative (CSII). Enantioseparation of fenoxaprop was found to be independent of steric hindrance.

Technology Integration Barriers: Urban School Mathematics Teachers Perspectives

NASA Astrophysics Data System (ADS)

Wachira, Patrick; Keengwe, Jared

2011-02-01

Despite the promise of technology in education, many practicing teachers face several challenges when trying to effectively integrate technology into their classroom instruction. Additionally, while national statistics cite a remarkable improvement in access to computer technology tools in schools, teacher surveys show consistent declines in the use and integration of computer technology to enhance student learning. This article reports on primary technology integration barriers that mathematics teachers identified when using technology in their classrooms. Suggestions to overcome some of these barriers are also provided.

Barriers, Successes and Enabling Practices of Education for Sustainability in Far North Queensland Schools: A Case Study

ERIC Educational Resources Information Center

Evans, Neus; Whitehouse, Hilary; Gooch, Margaret

2012-01-01

There are many documented barriers to implementing school-based sustainability. This article examines a) the barriers faced by principals and staff in two regional primary schools in Far North Queensland, Australia, well known for their exemplary practice, and b) ways the barriers were overcome. Through interviews conducted with principals and key…

Barriers to Industrial Energy Efficiency - Report to Congress, June 2015

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2015-06-01

This report examines barriers that impede the adoption of energy efficient technologies and practices in the industrial sector, and identifies successful examples and opportunities to overcome these barriers. Three groups of energy efficiency technologies and measures were examined: industrial end-use energy efficiency, industrial demand response, and industrial combined heat and power. This report also includes the estimated economic benefits from hypothetical Federal energy efficiency matching grants, as directed by the Act.

Comment on "Rabbit-Ears Hybrids, VSEPR Sterics, and Other Orbital Anachronisms": A Reply to a Criticism

ERIC Educational Resources Information Center

Hiberty, Philippe C.; Danovich, David; Shaik, Sason

2015-01-01

This commentary summarizes the authors' basic disagreements with the paper, "Rabbit-Ears, VSEPR Sterics, and Other Orbital Anachronisms," which criticizes the authors' usage of the hybrid orbitals for H[subscript 2]O in their book, "A Chemist's Guide to Valence Bond Theory" (Shaik and Hiberty, 2008). The current article shows…

Revealing climate modes in steric sea levels: lessons learned from satellite geodesy, objective analyses and ocean reanalyses

NASA Astrophysics Data System (ADS)

Pfeffer, J.; Tregoning, P.; Purcell, A. P.

2017-12-01

Due to increased greenhouse gases emissions, the oceans are accumulating heat. In response to the ocean circulation and atmospheric forcing, the heat is irregularly redistributed within the oceans, causing sea level to rise at variable rates in space and time. These rates of steric expansion are extremely difficult to assess because of the sparsity of in-situ hydrographic observations available within the course of the 20th century. We compare here three methods to reconstruct the steric sea levels over the past 13, 25 and 58 years based on satellite geodesy, objective analyses and ocean reanalyses. The interannual to decadal variability of each dataset is explored with a model merging six climate indices representative of the natural variability of the ocean and climate system. Consistent regional patterns are identified for the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) in all datasets at all timescales. Despite the short time coverage (13 years), the combination of satellite geodetic data (altimetry and GRACE) also reveals significant steric responses to the North Pacific Gyre Oscillation (NPGO), Indian Dipole (IOD) and Indian ocean basinwide (IOBM) mode. The richer information content in the ocean reanalyses allows us to recover the regional fingerprints of the PDO, ENSO, NPGO, IOD and IOBM, but also of the Atlantic Multidecadal Oscillation (AMO) acting over longer time scales (40 to 60 years). Therefore, ocean reanalyses, coupled with climate mode analyses, constitute innovative and promising tools to investigate the mechanisms triggering the variability of sea level rise over the past decades.

Barriers to Healthier Eating in a Disadvantaged Community

ERIC Educational Resources Information Center

O'Neill, Martin; Rebane, Deanne; Lester, Carolyn

2004-01-01

Objective: The research objective was to identify how healthy eating was understood in a disadvantaged community and how barriers to healthy eating might be overcome. Design: Participatory action research. Setting: Communities in Gurnos, Merthyr Tydfil, one of the most deprived areas in the UK. Method: Trainees on a participative methods course…

Blood brain barrier: a challenge for effectual therapy of brain tumors.

PubMed

Bhowmik, Arijit; Khan, Rajni; Ghosh, Mrinal Kanti

2015-01-01

Brain tumors are one of the most formidable diseases of mankind. They have only a fair to poor prognosis and high relapse rate. One of the major causes of extreme difficulty in brain tumor treatment is the presence of blood brain barrier (BBB). BBB comprises different molecular components and transport systems, which in turn create efflux machinery or hindrance for the entry of several drugs in brain. Thus, along with the conventional techniques, successful modification of drug delivery and novel therapeutic strategies are needed to overcome this obstacle for treatment of brain tumors. In this review, we have elucidated some critical insights into the composition and function of BBB and along with it we have discussed the effective methods for delivery of drugs to the brain and therapeutic strategies overcoming the barrier.

Steric-electronic effects in malarial peptides inducing sterile immunity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreno-Vranich, Armando; Patarroyo, Manuel E., E-mail: mepatarr@mail.com; Universidad Nacional de Colombia, Bogota

Highlights: Black-Right-Pointing-Pointer Is it evident that the residues position are relevant regarding of {phi} angular value. Black-Right-Pointing-Pointer The geometry considered for detailing the alterations undergone by HABPs. Black-Right-Pointing-Pointer The inter planar interactions ruled by clashes between the atoms making them up. -- Abstract: Conserved Plasmodium falciparum high activity binding peptides' (HABPs) most relevant proteins involved in malaria parasite invasion are immunologically silent; critical binding residues must therefore be specifically replaced to render them highly immunogenic and protection-inducing. Such changes have a tremendous impact on these peptides' steric-electronic effects, such as modifications to peptide length peptide bonds and electronic orbitals' disposition,more » to allow a better fit into immune system MHCII molecules and better interaction with the TCR which might account for the final immunological outcome.« less

The Employers' perspective on barriers and facilitators to employment of people with intellectual disability: A differential mixed-method approach.

PubMed

Kocman, Andreas; Fischer, Linda; Weber, Germain

2018-01-01

Obtaining employment is among the most important ambitions of people with intellectual disability. Progress towards comprehensive inclusive employment is hampered by numerous barriers. Limited research is available on these barriers and strategies to overcome them. A mixed method approach in a sample of 30 HR-managers was used to assess (i) differences in perceived barriers for employment of people with specific disabilities and mental disorders; (ii) barriers specific to employing people with intellectual disability; (iii) strategies to overcome these barriers. Employers perceive more barriers for hiring people with intellectual disability and mental disorders than for physical disabilities. Employment for this population is hampered by a perceived lack of skills and legal issues. Strategies perceived as beneficial are supplying information, changes in organizational strategies and legal changes. Employers' differentiated expectations and reservations towards hiring individuals with specific disabilities need to be taken into account to increase employment for people with intellectual disability. © 2017 John Wiley & Sons Ltd.

Extremely bulky secondary phosphinoamines as substituents for sterically hindered aminosilanes.

PubMed

Böttcher, Tobias; Jones, Cameron

2015-09-07

The synthesis of a series of extremely bulky secondary amines with a phosphine function, Ar(†)(PR2)NH (Ar(†) = C6H2{C(H)Ph2}2Pr(i)-2,6,4; R = Ph, NEt2, NPr(i)2) is described. Deprotonation with either n-BuLi or KH yields the respective alkali metal amides in some cases. Their reaction with the chlorosilanes SiCl4, HSiCl3, Cl2SiPh2, Cl3Si-SiCl3 and Si5Cl10 allows access to monomeric molecular compounds bearing the extremely bulky amino substituents via salt elimination. The products obtained may serve as precursors for subsequent reduction reactions to access sterically protected low valent and low coordinate silicon compounds.

Nanocrystal: a novel approach to overcome skin barriers for improved topical drug delivery.

PubMed

Patel, Viral; Sharma, Om Prakash; Mehta, Tejal

2018-04-01

Skin is an important route of drug delivery for the treatment of various dermatological conditions. The advent of nanotechnology is paving the roadmaps for topical drug delivery by providing sustained release as well as maintaining a localized effect, outweighing the toxicity concern. Area covered: This review highlighted the morphology of skin, its barrier nature as well as drug penetration pathways after topical application of formulations. The existing methods to improve topical drug delivery, by infringing or permeating the skin barriers, are discussed. This context concretes the foundation to accentuate the need for the development of nanocrystal-based topical formulation. The mechanism of drug release, immediate as well as sustained release, after topical administration of drug nanocrystals is also elaborated. The special emphasis is given on the breakthrough achieved, in topical drug delivery using drug nanocrystals, so far in the plethora of literature, patents, and products, under clinical trial as well as in the market. Expert opinion: The current research on nanocrystals for topical drug delivery is highlighting the breakthroughs achieved so far. The output of these research envisages that topical nanocrystals based formulations can be a novel strategy for the drugs which are facing solubility, bioavailability and toxicity concerns.

Overcoming recruitment challenges in palliative care clinical trials.

PubMed

LeBlanc, Thomas W; Lodato, Jordan E; Currow, David C; Abernethy, Amy P

2013-11-01

Palliative care is increasingly viewed as a necessary component of cancer care, especially for patients with advanced disease. Rigorous clinical trials are thus needed to build the palliative care evidence base, but clinical research-especially participant recruitment-is difficult. Major barriers include (1) patient factors, (2) "gatekeeping," and (3) ethical concerns. Here we discuss an approach to overcoming these barriers, using the Palliative Care Trial (PCT) as a case study. The PCT was a 2 × 2 × 2 factorial randomized controlled trial (RCT) of different service delivery models to improve pain control in the palliative setting. It used a recruitment protocol that fused evidence-based strategies with principles of "social marketing," an approach involving the systematic application of marketing techniques. Main components included (1) an inclusive triage algorithm, (2) information booklets targeting particular stakeholders, (3) a specialized recruitment nurse, and (4) standardization of wording across all study communications. From an eligible pool of 607 patients, the PCT enrolled 461 patients over 26 months. Twenty percent of patients referred to the palliative care service were enrolled (76% of those eligible after screening). Several common barriers were minimized; among those who declined participation, family disinterest was uncommon (5%), as was the perception of burden imposed (4%). Challenges to clinical trial recruitment in palliative care are significant but not insurmountable. A carefully crafted recruitment and retention protocol can be effective. Our experience with designing and deploying a social-marketing-based protocol shows the benefits of such an approach.

Sports participation after rehabilitation: Barriers and facilitators.

PubMed

Jaarsma, Eva A; Dekker, Rienk; Geertzen, Jan H B; Dijkstra, Pieter U

2016-01-01

To analyse barriers to, and facilitators of, sports participation among people with physical disabilities after rehabilitation and to compare differences between inactive and active participants regarding these experienced barriers and facilitators. Participants were 1,223 adults (mean age 51.6 years, standard deviation 15.1 years) treated in the Rehabilitation Centre of the University Medical Center Groningen, who completed a questionnaire. The questionnaire consisted of a self-constructed questionnaire regarding barriers and facilitators. Fifty-eight percent of the participants were active in sports after their rehabilitation. Younger age and a higher level of education were positively associated with sports participation, whereas using assistive devices and experiencing environmental barriers were negatively associated. Facilitators of sports participation were health, fun and increasing physical strength, and advice from rehabilitation professionals. Rehabilitation professionals should emphasize the health benefits of, and enjoyment from, sports participation for people with physical disabilities. They should repeatedly remind people with physical disabilities to stay/become active after completing their rehabilitation programme. Rehabilitation professionals should also provide information about strategies to reduce environmental barriers to sports participation, which could help people using assistive devices to overcome these barriers.

Industry-College Cooperation: New Components, Barriers and Strategies.

ERIC Educational Resources Information Center

Rinehart, Richard L.

A variety of linkage components that can help build and maintain effective relationships between the worlds of work and education are identified, and barriers to the development of such relationships and techniques for overcoming them are described in this report. The first section lists different forms of industry/education cooperation and their…

Steric interactions lead to collective tilting motion in the ribosome during mRNA-tRNA translocation

NASA Astrophysics Data System (ADS)

Nguyen, Kien; Whitford, Paul C.

2016-02-01

Translocation of mRNA and tRNA through the ribosome is associated with large-scale rearrangements of the head domain in the 30S ribosomal subunit. To elucidate the relationship between 30S head dynamics and mRNA-tRNA displacement, we apply molecular dynamics simulations using an all-atom structure-based model. Here we provide a statistical analysis of 250 spontaneous transitions between the A/P-P/E and P/P-E/E ensembles. Consistent with structural studies, the ribosome samples a chimeric ap/P-pe/E intermediate, where the 30S head is rotated ~18°. It then transiently populates a previously unreported intermediate ensemble, which is characterized by a ~10° tilt of the head. To identify the origins of head tilting, we analyse 781 additional simulations in which specific steric features are perturbed. These calculations show that head tilting may be attributed to specific steric interactions between tRNA and the 30S subunit (PE loop and protein S13). Taken together, this study demonstrates how molecular structure can give rise to large-scale collective rearrangements.

Steric hindrance effects in the use of heterocyclic azodyestuffs as spectrophotometric reagents.

PubMed

Geary, W J; Bottomley, F

1967-05-01

The heterocyclic azo dyestuffs 4-(n-methyl-2 -pyridylazo)-resorcinol (where n = 3', 4', 5', 6') have been prepared, and their possible use as spectrophotometric reagents investigated. The dyestuffs are shown to function analogously to the parent ligand 4-(2'-pyridylazo) resorcinol (PAR) in giving red complexes with the ions Co(2+), Ni(2+), Cu(2+), Zn(2+) and UO(2)(2+). Steric effects resulting from the position of the methyl group in the heterocyclic ring are shown to occur in relation both to the spectra of the dyestuffs themselves and to the sensitivity of their reactions with the metal ions.

Deconstructing barriers: perceptions of students labeled with learning disabilities in higher education.

PubMed

Denhart, Hazel

2008-01-01

This phenomenological study investigated barriers to higher education faced by 11 college students labeled with learning disabilities (LD) using their voice as the primary data. Data were analyzed and interpreted through a disability theory perspective revealing barriers stemmed largely from external social causes rather than individual pathology. Barriers included being misunderstood by faculty, being reluctant to request accommodations for fear of invoking stigma, and having to work considerably longer hours than nonlabeled peers. Findings indicated barriers could be overcome through raising faculty awareness about LD issues, engaging the assistance of the college LD specialist, and participation in a LD democratic empowerment community on campus.

Role of water and steric constraints in the kinetics of cavity-ligand unbinding.

PubMed

Tiwary, Pratyush; Mondal, Jagannath; Morrone, Joseph A; Berne, B J

2015-09-29

A key factor influencing a drug's efficacy is its residence time in the binding pocket of the host protein. Using atomistic computer simulation to predict this residence time and the associated dissociation process is a desirable but extremely difficult task due to the long timescales involved. This gets further complicated by the presence of biophysical factors such as steric and solvation effects. In this work, we perform molecular dynamics (MD) simulations of the unbinding of a popular prototypical hydrophobic cavity-ligand system using a metadynamics-based approach that allows direct assessment of kinetic pathways and parameters. When constrained to move in an axial manner, the unbinding time is found to be on the order of 4,000 s. In accordance with previous studies, we find that the cavity must pass through a region of sharp wetting transition manifested by sudden and high fluctuations in solvent density. When we remove the steric constraints on ligand, the unbinding happens predominantly by an alternate pathway, where the unbinding becomes 20 times faster, and the sharp wetting transition instead becomes continuous. We validate the unbinding timescales from metadynamics through a Poisson analysis, and by comparison through detailed balance to binding timescale estimates from unbiased MD. This work demonstrates that enhanced sampling can be used to perform explicit solvent MD studies at timescales previously unattainable, to our knowledge, obtaining direct and reliable pictures of the underlying physiochemical factors including free energies and rate constants.

Role of water and steric constraints in the kinetics of cavity–ligand unbinding

PubMed Central

Tiwary, Pratyush; Mondal, Jagannath; Morrone, Joseph A.; Berne, B. J.

2015-01-01

A key factor influencing a drug’s efficacy is its residence time in the binding pocket of the host protein. Using atomistic computer simulation to predict this residence time and the associated dissociation process is a desirable but extremely difficult task due to the long timescales involved. This gets further complicated by the presence of biophysical factors such as steric and solvation effects. In this work, we perform molecular dynamics (MD) simulations of the unbinding of a popular prototypical hydrophobic cavity–ligand system using a metadynamics-based approach that allows direct assessment of kinetic pathways and parameters. When constrained to move in an axial manner, the unbinding time is found to be on the order of 4,000 s. In accordance with previous studies, we find that the cavity must pass through a region of sharp wetting transition manifested by sudden and high fluctuations in solvent density. When we remove the steric constraints on ligand, the unbinding happens predominantly by an alternate pathway, where the unbinding becomes 20 times faster, and the sharp wetting transition instead becomes continuous. We validate the unbinding timescales from metadynamics through a Poisson analysis, and by comparison through detailed balance to binding timescale estimates from unbiased MD. This work demonstrates that enhanced sampling can be used to perform explicit solvent MD studies at timescales previously unattainable, to our knowledge, obtaining direct and reliable pictures of the underlying physiochemical factors including free energies and rate constants. PMID:26371312

Barriers to female sex addiction treatment in the UK.

PubMed

Dhuffar, Manpreet K; Griffiths, Mark D

2016-12-01

Background Over the last 20 years, behavioral addictions (e.g., addictions to gambling, playing video games, work, etc.) have become more accepted among both public and scientific communities. Addiction to sex is arguably a more controversial issue, but this does not take away from the fact that some individuals seek professional help for problematic excessive sex, irrespective of how the behavior is conceptualized. Empirical evidence suggests that among treatment seekers, men are more likely than women to seek help for sex addiction (SA). Methods Using the behavioral addiction literature and the authors' own expertise in researching female SA, this paper examines potential barriers to the treatment for female sex addicts. Results Four main types of barriers for female sex addicts not seeking treatment were identified. These comprised (a) individual barriers, (b) social barriers, (c) research barriers, and (d) treatment barriers. Conclusions Further research is needed to either confirm or disconfirm the identified barriers that female sex addicts face when seeking treatment, and if conformation is found, interested stakeholders should provide better awareness and/or see ways in which such barriers can be overcome to aid better uptake of SA services.

Overcoming Barriers to Family Planning through Integration: Perspectives of HIV-Positive Men in Nyanza Province, Kenya

PubMed Central

Steinfeld, Rachel L.; Newmann, Sara J.; Onono, Maricianah; Cohen, Craig R.; Bukusi, Elizabeth A.; Grossman, Daniel

2013-01-01

This study explored barriers to and facilitators of using family planning services among HIV-positive men in Nyanza Province, Kenya. From May to June 2010, in-depth interviews were conducted with 30 men receiving care at 15 HIV clinics. The key barriers to the use of family planning included concerns about side effects of contraceptives, lack of knowledge about contraceptive methods, myths and misconceptions including fear of infertility, structural barriers such as staffing shortages at HIV clinics, and a lack of male focus in family planning methods and service delivery. The integration of family planning into HIV clinics including family planning counseling and education was cited as an important strategy to improve family planning receptivity among men. Integrating family planning into HIV services is a promising strategy to facilitate male involvement in family planning. Integration needs to be rigorously evaluated in order to measure its impact on unmet need for contraception among HIV-positive women and their partners and assure that it is implemented in a manner that engages both men and women. PMID:23738057

Building a Three-Dimensional Nano-Bio Interface for Aptasensing: An Analytical Methodology Based on Steric Hindrance Initiated Signal Amplification Effect.

PubMed

Du, Xiaojiao; Jiang, Ding; Hao, Nan; Qian, Jing; Dai, Liming; Zhou, Lei; Hu, Jianping; Wang, Kun

2016-10-04

The development of novel detection methodologies in electrochemiluminescence (ECL) aptasensor fields with simplicity and ultrasensitivity is essential for constructing biosensing architectures. Herein, a facile, specific, and sensitive methodology was developed unprecedentedly for quantitative detection of microcystin-LR (MC-LR) based on three-dimensional boron and nitrogen codoped graphene hydrogels (BN-GHs) assisted steric hindrance amplifying effect between the aptamer and target analytes. The recognition reaction was monitored by quartz crystal microbalance (QCM) to validate the possible steric hindrance effect. First, the BN-GHs were synthesized via self-assembled hydrothermal method and then applied as the Ru(bpy) 3 2+ immobilization platform for further loading the biomolecule aptamers due to their nanoporous structure and large specific surface area. Interestingly, we discovered for the first time that, without the aid of conventional double-stranded DNA configuration, such three-dimensional nanomaterials can directly amplify the steric hindrance effect between the aptamer and target analytes to a detectable level, and this facile methodology could be for an exquisite assay. With the MC-LR as a model, this novel ECL biosensor showed a high sensitivity and a wide linear range. This strategy supplies a simple and versatile platform for specific and sensitive determination of a wide range of aptamer-related targets, implying that three-dimensional nanomaterials would play a crucial role in engineering and developing novel detection methodologies for ECL aptasensing fields.

The effects of temperature on the lattice barrier for twin wall motion

NASA Astrophysics Data System (ADS)

Zreihan, Noam; Faran, Eilon; Shilo, Doron

2015-07-01

The sideways motion of twin walls in ferroic materials requires overcoming an intrinsic energy barrier that originates from the periodicity of the crystal structure. Here, we measure the temperature dependence of the lattice barrier in a ferromagnetic Ni-Mn-Ga crystal using the pulsed magnetic field method. Our results reveal a monotonic decrease in the lattice barrier with increasing temperature. Yet, the barrier does not vanish as the temperature approaches the temperature of the martensite to austenite transformation. These findings enable the formulation of an analytical expression that correlates the lattice barrier to the physical properties of the twin wall, such as its thickness and the associated transformation strain. The derived relation provides a good quantitative description of the data measured in Ni-Mn-Ga.

Reducing Barriers To The Use of High-Efficiency Lighting Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peter Morante

2005-12-31

With funding from the U.S. Department of Energy (DOE), the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute completed the four-year research project, Reducing Barriers to the Use of High-Efficiency Lighting Systems. The initial objectives were: (1) identifying barriers to widespread penetration of lighting controls in commercial/industrial (C/I) applications that employ fluorescent lamp technologies, and (2) making recommendations to overcome these barriers. The addition of a fourth year expanded the original project objectives to include an examination of the impact on fluorescent lamps from dimming utilizing different lamp electrode heating and dimming ratios. The scope of the project was narrowedmore » to identify barriers to the penetration of lighting controls into commercial-industrial (C/I) applications that employ fluorescent lamp technologies, and to recommend means for overcoming these barriers. Working with lighting manufacturers, specifiers, and installers, the project identified technological and marketing barriers to the widespread use of lighting controls, specifically automatic-off controls, occupancy sensors, photosensors, dimming systems, communication protocols and load-shedding ballasts. The primary barriers identified include cost effectiveness of lighting controls to the building owner, lack of standard communication protocols to allow different part of the control system to communicate effectively, and installation and commissioning issues. Overcoming the identified barriers requires lighting control products on the market to achieve three main goals: (1) Achieve sufficient functionality to meet the key requirements of their main market. (2) Allow significant cost reduction compared to current market standard systems. Cost should consider: hardware capital cost including wiring, design time required by the specifier and the control system manufacturer, installation time required by the electrician, and commissioning time

A prospective examination of exercise and barrier self-efficacy to engage in leisure-time physical activity during pregnancy.

PubMed

Cramp, Anita G; Bray, Steven R

2009-06-01

Pregnant women without medical contraindications should accumulate 30 min of moderate exercise on most days of the week, yet many pregnant women do not exercise at recommended levels. The purpose the study was to examine barriers to leisure-time physical activity (LTPA) and investigate barrier and exercise self-efficacy as predictors of self-reported LTPA during pregnancy. Pregnant women (n = 160) completed questionnaires eliciting barriers to LTPA, measures of exercise and barrier self-efficacy, and 6-week LTPA recall at gestational weeks 18, 24, 30, and 36. A total of 1,168 barriers were content-analyzed, yielding nine major themes including fatigue, time constraints, and physical limitations. Exercise self-efficacy predicted LTPA from gestational weeks 18 to 24 (beta = 0.32, R(2) = 0.26) and weeks 30 to 36 (beta = 0.41, R(2) = 0.37), while barrier self-efficacy predicted LTPA from weeks 24 to 30 (beta = 0.40, R(2) = 0.32). Pregnant women face numerous barriers to LTPA during pregnancy, the nature of which may change substantially over the course of pregnancy. Higher levels of self-efficacy to exercise and to overcome exercise barriers are associated with greater LTPA during pregnancy. Research and interventions to understand and promote LTPA during pregnancy should explore the dynamic nature of exercise barriers and foster women's confidence to overcome physical activity barriers.

Overcoming barriers to addressing education problems with research design: a panel discussion.

PubMed

Yarris, Lalena M; Gruppen, Larry D; Hamstra, Stanley J; Anders Ericsson, K; Cook, David A

2012-12-01

A plenary panel session at the 2012 Academic Emergency Medicine consensus conference "Education Research in Emergency Medicine: Opportunities, Challenges, and Strategies for Success" discussed barriers educators face in imagining, designing, and implementing studies to address educational challenges. This proceedings article presents a general approach to getting started in education research. Four examples of studies from the medical education literature that illustrate a distinct way to approach specific research questions are discussed. The study designs used are applicable to a variety of education research problems in emergency medicine (EM). Potential applications of studies are discussed, as well as effects and lessons learned. © 2012 by the Society for Academic Emergency Medicine.

Sterically controlled mechanochemistry under hydrostatic pressure

NASA Astrophysics Data System (ADS)

Yan, Hao; Yang, Fan; Pan, Ding; Lin, Yu; Hohman, J. Nathan; Solis-Ibarra, Diego; Li, Fei Hua; Dahl, Jeremy E. P.; Carlson, Robert M. K.; Tkachenko, Boryslav A.; Fokin, Andrey A.; Schreiner, Peter R.; Galli, Giulia; Mao, Wendy L.; Shen, Zhi-Xun; Melosh, Nicholas A.

2018-02-01

Mechanical stimuli can modify the energy landscape of chemical reactions and enable reaction pathways, offering a synthetic strategy that complements conventional chemistry. These mechanochemical mechanisms have been studied extensively in one-dimensional polymers under tensile stress using ring-opening and reorganization, polymer unzipping and disulfide reduction as model reactions. In these systems, the pulling force stretches chemical bonds, initiating the reaction. Additionally, it has been shown that forces orthogonal to the chemical bonds can alter the rate of bond dissociation. However, these bond activation mechanisms have not been possible under isotropic, compressive stress (that is, hydrostatic pressure). Here we show that mechanochemistry through isotropic compression is possible by molecularly engineering structures that can translate macroscopic isotropic stress into molecular-level anisotropic strain. We engineer molecules with mechanically heterogeneous components—a compressible (‘soft’) mechanophore and incompressible (‘hard’) ligands. In these ‘molecular anvils’, isotropic stress leads to relative motions of the rigid ligands, anisotropically deforming the compressible mechanophore and activating bonds. Conversely, rigid ligands in steric contact impede relative motion, blocking reactivity. We combine experiments and computations to demonstrate hydrostatic-pressure-driven redox reactions in metal-organic chalcogenides that incorporate molecular elements that have heterogeneous compressibility, in which bending of bond angles or shearing of adjacent chains activates the metal-chalcogen bonds, leading to the formation of the elemental metal. These results reveal an unexplored reaction mechanism and suggest possible strategies for high-specificity mechanosynthesis.

Modeling Multivalent Ligand-Receptor Interactions with Steric Constraints on Configurations of Cell-Surface Receptor Aggregates

PubMed Central

Monine, Michael I.; Posner, Richard G.; Savage, Paul B.; Faeder, James R.; Hlavacek, William S.

2010-01-01

Abstract We use flow cytometry to characterize equilibrium binding of a fluorophore-labeled trivalent model antigen to bivalent IgE-FcεRI complexes on RBL cells. We find that flow cytometric measurements are consistent with an equilibrium model for ligand-receptor binding in which binding sites are assumed to be equivalent and ligand-induced receptor aggregates are assumed to be acyclic. However, this model predicts extensive receptor aggregation at antigen concentrations that yield strong cellular secretory responses, which is inconsistent with the expectation that large receptor aggregates should inhibit such responses. To investigate possible explanations for this discrepancy, we evaluate four rule-based models for interaction of a trivalent ligand with a bivalent cell-surface receptor that relax simplifying assumptions of the equilibrium model. These models are simulated using a rule-based kinetic Monte Carlo approach to investigate the kinetics of ligand-induced receptor aggregation and to study how the kinetics and equilibria of ligand-receptor interaction are affected by steric constraints on receptor aggregate configurations and by the formation of cyclic receptor aggregates. The results suggest that formation of linear chains of cyclic receptor dimers may be important for generating secretory signals. Steric effects that limit receptor aggregation and transient formation of small receptor aggregates may also be important. PMID:20085718

Barriers in education of indigenous nursing students: a literature review.

PubMed

Foxall, Donna

2013-11-01

The poor health status of indigenous people has been identified internationally as a critical issue. It is now commonly accepted that the ability to address this concern is hindered, in part, by the disproportionately low number of indigenous health professionals, including nurses. This paper reports the findings of a review of literature that aimed to identify key barriers in the education of the indigenous undergraduate nursing students in the tertiary sector, to identify strategies to overcome these, and discuss these elements within the New Zealand context. A number of health-related databases were searched and a total of 16 peer-reviewed articles from Canada, U.S.A., Australia and New Zealand were reviewed. Key barriers to recruitment and retention and strategies to overcome these are presented. Barriers to recruitment included: academic unpreparedness; poor understanding of cultural needs; and conflicting obligations, and financial constraints. Barriers to retention included lack of cultural and academic support, family obligations and financial hardship. Strategies to address recruitment barriers included: addressing pre-entry education requirements; targeted promotion of nursing programmes; indigenous role models in the recruitment process; and streamlining enrolment processes to make programmes attractive and attainable for indigenous students. Strategies to address retention barriers included: cultural relevance within the curriculum; identifying and supporting cultural needs of indigenous students with active participation of indigenous staff; engaging communities and funding support. The crucial development of partnerships between academic institutes and indigenous communities to ensure the provision of a culturally safe, supportive environment for the students was stressed. In New Zealand, while government-level policy exists to promote the success of MBori nursing students, the translation of what is known about the recruitment and retention of

Exercise barriers self-efficacy: development and validation of a subcale for individuals with cancer-related lymphedema.

PubMed

Buchan, Jena; Janda, Monika; Box, Robyn; Rogers, Laura; Hayes, Sandi

2015-03-18

No tool exists to measure self-efficacy for overcoming lymphedema-related exercise barriers in individuals with cancer-related lymphedema. However, an existing scale measures confidence to overcome general exercise barriers in cancer survivors. Therefore, the purpose of this study was to develop, validate and assess the reliability of a subscale, to be used in conjunction with the general barriers scale, for determining exercise barriers self-efficacy in individuals facing lymphedema-related exercise barriers. A lymphedema-specific exercise barriers self-efficacy subscale was developed and validated using a cohort of 106 cancer survivors with cancer-related lymphedema, from Brisbane, Australia. An initial ten-item lymphedema-specific barrier subscale was developed and tested, with participant feedback and principal components analysis results used to guide development of the final version. Validity and test-retest reliability analyses were conducted on the final subscale. The final lymphedema-specific subscale contained five items. Principal components analysis revealed these items loaded highly (>0.75) on a separate factor when tested with a well-established nine-item general barriers scale. The final five-item subscale demonstrated good construct and criterion validity, high internal consistency (Cronbach's alpha = 0.93) and test-retest reliability (ICC = 0.67, p < 0.01). A valid and reliable lymphedema-specific subscale has been developed to assess exercise barriers self-efficacy in individuals with cancer-related lymphedema. This scale can be used in conjunction with an existing general exercise barriers scale to enhance exercise adherence in this understudied patient group.

Barriers to pediatric pain management: a nursing perspective.

PubMed

Czarnecki, Michelle L; Simon, Katherine; Thompson, Jamie J; Armus, Cheryl L; Hanson, Tom C; Berg, Kristin A; Petrie, Jodie L; Xiang, Qun; Malin, Shelly

2011-09-01

This study describes strategies used by the Joint Clinical Practice Council of Children's Hospital of Wisconsin to identify barriers perceived as interfering with nurses' (RNs) ability to provide optimal pain management. A survey was used to ascertain how nurses described optimal pain management and how much nurses perceived potential barriers as interfering with their ability to provide that level of care. The survey, "Barriers to Optimal Pain management" (adapted from Van Hulle Vincent & Denyes, 2004), was distributed to all RNs working in all patient care settings. Two hundred seventy-two surveys were returned. The five most significant barriers identified were insufficient physician (MD) orders, insufficient MD orders before procedures, insufficient time to premedicate patients before procedures, the perception of a low priority given to pain management by medical staff, and parents' reluctance to have patients receive pain medication. Additional barriers were identified through narrative comments. Information regarding the impact of the Acute Pain Service on patient care, RNs' ability to overcome barriers, and RNs' perception of current pain management practices is included, as are several specific interventions aimed at improving or ultimately eliminating identified barriers. Copyright © 2011 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Social, ethical and legal barriers to e-health.

PubMed

Anderson, James G

2007-01-01

Information technology such as electronic medical records (EMRs), electronic prescribing and decision support systems are recognized as essential tools in Europe, the U.S., Canada, Australia, and New Zealand. But significant barriers impede wide-scale adoption of these tools, especially EMR systems. The objectives of this study were to investigate the present status of information technology in health care, the perceived benefits and barriers by primary care physicians. Literature analysis and survey data from primary care physicians on adoption of information technology are reviewed. The U.S. trails European countries as well as Canada, Australia and New Zealand in the use of information technology in primary care. The results of the study indicate that physicians in general perceive benefits to information technology, but also cite major barriers to its implementation in their practices. These barriers include lack of access to capital by health care providers, complex systems and lack of data standards that permit exchange of clinical data, privacy concerns and legal barriers. Overcoming these barriers will require subsidies and performance incentives by payers and government; certification and standardization of vendor applications that permit clinical data exchange; removal of legal barriers; and greater security of medical data to convince practitioners and patients of the value of EMRs.

Sexual health and gynecological cancer: conceptualizing patient needs and overcoming barriers to seeking and accessing services.

PubMed

McCallum, Megan; Lefebvre, Monique; Jolicoeur, Lynne; Maheu, Christine; Lebel, Sophie

2012-09-01

The current study explored the subjective experiences of women treated for a gynecological cancer, with a focus on filling gaps in the current literature. Topics explored were: (1) women's own definitions of healthy sexuality; (2) services desired to meet needs; and (3) barriers to participation in sexual health-related services. Fifteen women participated in a one-on-one, semistructured interview. Data collection and analysis were based on guidelines of interpretive description. Definitions of healthy sexuality included emotional intimacy, body image, sexual self-schema, and sexual response. Unmet sexual needs were reported when women's current sexual experiences did not correspond with their subjective perceptions of healthy sexuality. Most women desired informational services, delivered one-on-one or through written material. Younger women often did not utilize services due to practical barriers and emotional avoidance, while older women reported that shyness and stigma discouraged them from discussing sexuality with their health care team. In order to understand patient needs and desire for help, health care providers should assess current sexual health and patient perceptions of healthy sexuality. To increase effectiveness of distress screening and treatment interventions, potential barriers must be evaluated and addressed.

Learning from the best: Overcoming barriers to reforms-based elementary science teaching

NASA Astrophysics Data System (ADS)

Banchi, Heather May

This study explored the characteristics of elementary science teachers who employ reforms-based practices. Particular attention was paid to the consistency of teachers' practices and their beliefs, the impact of professional development experiences on practices, and how teachers mitigated barriers to reforms-based instruction. Understanding how successful elementary science teachers develop fills a gap in the science reforms literature. Participants included 7 upper elementary science teachers from six different schools. All schools were located within two suburban school districts in the south-Atlantic United States and data was collected during the spring of 2008. Data collection included use of the Reformed Teaching Observation Protocol (RTOP) to evaluate the level of reforms-based instruction, as well as 35 hours of classroom observation field notes and 21 hours of audio-taped teacher interviews. The variety of data sources allowed for triangulation of evidence. The RTOP was analyzed using descriptive statistics and classroom observations and interview data were analyzed using Erickson's (1986) guidelines for analytic induction. Findings indicated (a) reforms-based elementary science teaching was attainable, (b) beliefs and practices were consistent and both reflected reforms-based philosophies and practices, (c) formal professional development experiences were limited and did not foster reforms-based practices, (d) informal professional development pursued by teachers had a positive impact on practices, (e) barriers to reforms-based instruction were present but mitigated by strong beliefs and practical strategies like curriculum integration. These findings suggest that there are common, salient characteristics of reforms-based teachers' beliefs, practices, and professional development experiences. These commonalities contribute to an understanding of how reforms-based teachers develop, and inform efforts to move all elementary teachers in the direction of

Benefits, Facilitators, Barriers, and Strategies to Improve Pesticide Protective Behaviors: Insights from Farmworkers in North Carolina Tobacco Fields

PubMed Central

Linnan, Laura; Sanchez-Birkhead, Ana; Mooney, Kathi

2017-01-01

Pesticide exposure is associated with deleterious health effects. Prior studies suggest Latino farmworkers perceive little control over their occupational health. Using the Health Belief Model as a theoretical guide, we explored the perceptions of Latino farmworkers working in tobacco in North Carolina (n = 72) about benefits and facilitators of pesticide protective behaviors as well as barriers, and strategies to overcome barriers to their use. Interviews were conducted with participants at farmworker housing during non-work time. Qualitative data were analyzed using ATLAS.ti. Farmworkers recognized pesticide protective behaviors as helping them to not get sick and stay healthy. Farmworkers perceived work experience as facilitating protective behaviors. Wetness in the field was the most commonly cited barrier to protective behavior use. To overcome this barrier, farmworkers suggested use of water-resistant outerwear, as well as packing a change of clothes for mid-day, with space and time to change provided by employers. Examination of the efficacy and feasibility of farmworkers’ suggestions for addressing barriers is warranted. Training and behavior modeling by experienced peers may improve behavior adoption and perceived control. PMID:28644414

Benefits, Facilitators, Barriers, and Strategies to Improve Pesticide Protective Behaviors: Insights from Farmworkers in North Carolina Tobacco Fields.

PubMed

Walton, AnnMarie Lee; LePrevost, Catherine E; Linnan, Laura; Sanchez-Birkhead, Ana; Mooney, Kathi

2017-06-23

Pesticide exposure is associated with deleterious health effects. Prior studies suggest Latino farmworkers perceive little control over their occupational health. Using the Health Belief Model as a theoretical guide, we explored the perceptions of Latino farmworkers working in tobacco in North Carolina ( n = 72) about benefits and facilitators of pesticide protective behaviors as well as barriers, and strategies to overcome barriers to their use. Interviews were conducted with participants at farmworker housing during non-work time. Qualitative data were analyzed using ATLAS.ti. Farmworkers recognized pesticide protective behaviors as helping them to not get sick and stay healthy. Farmworkers perceived work experience as facilitating protective behaviors. Wetness in the field was the most commonly cited barrier to protective behavior use. To overcome this barrier, farmworkers suggested use of water-resistant outerwear, as well as packing a change of clothes for mid-day, with space and time to change provided by employers. Examination of the efficacy and feasibility of farmworkers' suggestions for addressing barriers is warranted. Training and behavior modeling by experienced peers may improve behavior adoption and perceived control.

Nucleosomal Barrier to Transcription: Structural Determinants and Changes in Chromatin Structure

PubMed Central

Studitsky, Vasily M.; Nizovtseva, Ekaterina V.; Shaytan, Alexey K.; Luse, Donal S.

2016-01-01

Packaging of DNA into chromatin affects all processes on DNA. Nucleosomes present a strong barrier to transcription, raising important questions about the nature and the mechanisms of overcoming the barrier. Recently it was shown that DNA sequence, DNA–histone interactions and backtracking by RNA polymerase II (Pol II) all contribute to formation of the barrier. After partial uncoiling of nucleosomal DNA from histone octamer by Pol II and backtracking of the enzyme, nucleosomal DNA recoils on the octamer, locking Pol II in the arrested state. Histone chaperones and transcription factors TFIIS, TFIIF and FACT facilitate transcription through chromatin using different molecular mechanisms. PMID:27754494

SAXS Study of Sterically Stabilized Lipid Nanocarriers Functionalized by DNA

NASA Astrophysics Data System (ADS)

Angelov, Borislav; Angelova, Angelina; Filippov, Sergey; Karlsson, Göran; Terrill, Nick; Lesieur, Sylviane; Štěpánek, Petr

2012-03-01

The structure of novel spontaneously self-assembled plasmid DNA/lipid complexes is investigated by means of synchrotron radiation small-angle X-ray scattering (SAXS) and Cryo-TEM imaging. Liquid crystalline (LC) hydrated lipid systems are prepared using the non-ionic lipids monoolein and DOPE-PEG2000 and the cationic amphiphile CTAB. The employed plasmid DNA (pDNA) is encoding for the human protein brain-derived neurotrophic factor (BDNF). A coexistence of nanoparticulate objects with different LC inner organizations is established. A transition from bicontinuous membrane sponges, cubosome intermediates and unilamelar liposomes to multilamellar vesicles, functionalized by pDNA, is favoured upon binding and compaction of pBDNF onto the cationic PEGylated lipid nanocarriers. The obtained sterically stabilized multicompartment nanoobjects, with confined supercoiled plasmid DNA (pBDNF), are important in the context of multicompartment lipid nanocarriers of interest for gene therapy of neurodegenerative diseases.

The Need for More Research on Language Barriers in Health Care: A Proposed Research Agenda

PubMed Central

Jacobs, Elizabeth; Chen, Alice HM; Karliner, Leah S; Agger-Gupta, Niels; Mutha, Sunita

2006-01-01

Many U.S. residents who speak little English may face language barriers when seeking health care. This article describes what is currently known about language barriers in health care and outlines a research agenda based on mismatches between the current state of knowledge of language barriers and what health care stakeholders need to know. Three broad areas needing more research are discussed: the ways in which language barriers affect health and health care, the efficacy of linguistic access service interventions, and the costs of language barriers and efforts to overcome them. In each of these areas, we outline specific research questions and recommendations. PMID:16529570

Steric restrictions of RISC in RNA interference identified with size-expanded RNA nucleobases.

PubMed

Hernández, Armando R; Peterson, Larryn W; Kool, Eric T

2012-08-17

Understanding the interactions between small interfering RNAs (siRNAs) and the RNA-induced silencing complex (RISC), the key protein complex of RNA interference (RNAi), is of great importance to the development of siRNAs with improved biological and potentially therapeutic function. Although various chemically modified siRNAs have been reported, relatively few studies with modified nucleobases exist. Here we describe the synthesis and hybridization properties of siRNAs bearing size-expanded RNA (xRNA) nucleobases and their use as a novel and systematic set of steric probes in RNAi. xRNA nucleobases are expanded by 2.4 Å using benzo-homologation and retain canonical Watson-Crick base-pairing groups. Our data show that the modified siRNA duplexes display small changes in melting temperature (+1.4 to -5.0 °C); substitutions near the center are somewhat destabilizing to the RNA duplex, while substitutions near the ends are stabilizing. RNAi studies in a dual-reporter luciferase assay in HeLa cells revealed that xRNA nucleobases in the antisense strand reduce activity at some central positions near the seed region but are generally well tolerated near the ends. Most importantly, we observed that xRNA substitutions near the 3'-end increased activity over that of wild-type siRNAs. The data are analyzed in terms of site-dependent steric effects in RISC. Circular dichroism experiments show that single xRNA substitutions do not significantly distort the native A-form helical structure of the siRNA duplex, and serum stability studies demonstrated that xRNA substitutions protect siRNAs against nuclease degradation.

Double bonds? Studies on the barrier to rotation about the cumulenic C=C bonds of tetraaryl[n]cumulenes (n = 3, 5, 7, 9).

PubMed

Buehringer, Martina U; Padberg, Kevin; Phleps, Martin; Maid, Harald; Placht, Christian; Neiss, Christian; Ferguson, Michael; Goerling, Andreas; Tykwinski, Rik R

2018-03-31

Bonding is the fundamental aspect of organic chemistry, yet the magnitude of C=C bonding in [n]cumulenes as a function of increasing chain length has yet to be experimentally verified for derivatives longer than n = 5. The synthesis of a series of apolar and unsymmetrically substituted tetraaryl[n]cumulenes (n = 3, 5, 7, 9) has been developed and rotational barriers for Z-/E-isomerization have been measured using dynamic VT-NMR spectroscopy. Both experiment and theory confirm a dramatic reduction of the rotational barrier (through estimation of G≠rot for the isomerization) from >24 to 19 to 15 to 11 kcal-1 in [n]cumulenes with n = 3, 5, 7, 9, respectively. Thus, the reduction of cumulenic bonding in longer cumulenes affords bond rotational barriers that are more characteristic of a sterically hindered single bond than that of a double bond. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Barriers to immunization among children of migrant workers from Myanmar living in Tak province, Thailand.

PubMed Central

Plugge, Emma; Suwanjatuporn, Suporn; Sombatrungjaroen, Suteera; Nosten, François

2011-01-01

Abstract Problem Immunization is a cost-effective means of improving child survival but implementation of programmes in low- and middle-income countries is variable. Children of migrants are less likely to be immunized. Approach The qualitative study aimed to identify barriers to the successful implementation of migrant immunization programmes in Tak province, Thailand. We ran a total of 53 focus groups involving 371 participants in three sites. Local setting Tak province in Thailand borders Myanmar and has an estimated 200 000 migrants from Myanmar. Vaccine-preventable diseases are a documented cause of morbidity in this population but there is no systematic or coordinated immunization programme in the area. Relevant changes As a result of the findings, the subsequent immunization campaign targeted children in school to overcome those barriers of distance to immunization services, fear of arrest, not remembering immunization appointments, and the disruption of parental work. The campaigns also included immunization education for both parents and teachers. Lessons learnt Migrant parents identified similar barriers to accessing childhood immunization programmes as migrant populations elsewhere in the world, although a unique barrier identified by parents from Myanmar was “fear of arrest”. The subsequent school-based strategy to overcome these barriers appears to be effective. PMID:21734767

Breaking Barriers to Bike Share: Insights from Residents of Traditionally Underserved Neighborhoods

DOT National Transportation Integrated Search

2017-06-01

Evidence has shown that higher income and white populations are overrepresented in both access to and use of bike share. Efforts to overcome underserved communities barriers to access and use of bike share have been initiated in a number of cities...

Overcoming the barriers to patient-centred care: time, tools and training.

PubMed

West, Elizabeth; Barron, David N; Reeves, Rachel

2005-04-01

To investigate whether nurses experience barriers to delivering high quality care in areas that are of particular concern to patients and to describe which aspects of care are most affected when nurses lack the required resources, such as time, tools and training to do their job. Patient surveys conducted in the National Health Service of the United Kingdom tend to show there is variation in the extent to which they are satisfied with care in a number of important areas, such as physical comfort, emotional support and the coordination of care. A sample of nurses working in 20 acute London hospitals was asked to complete a postal questionnaire based on a prototype employee survey developed in the United States and adapted by the authors for use in the United Kingdom. Staff in the human resources departments of participating hospitals mailed the questionnaires to nurses' home addresses. After two reminders, 2880 (out of 6160) useable responses were returned, giving a response rate of 47%. Nurses are aware that there are deficits in standards of care in areas that are particularly important to patients. The majority feel overworked (64%) and report that they do not have enough time to perform essential nursing tasks, such as addressing patients' anxieties, fears and concerns and giving patients and relatives information. Their work is often made more difficult by the lack of staff, space, equipment and cleanliness. They are often unable to control noise and temperature in clinical areas. Nurses in acute London hospitals are subject to high levels of aggressive behaviour, mainly from patients and their relatives, but also from other members of staff. More positively, high proportions of the nurses in our survey expressed the desire for further training, particularly in social and interpersonal aspects of care. This paper goes beyond reporting problems with the quality and safety of care to try to understand why patients do not always receive optimum care in areas that

Sterically allowed configuration space for amino acid dipeptides

NASA Astrophysics Data System (ADS)

Caballero, Diego; Maatta, Jukka; Sammalkorpi, Maria; O'Hern, Corey; Regan, Lynne

2014-03-01

Despite recent improvements in computational methods for protein design, we still lack a quantitative, predictive understanding of the intrinsic propensities for amino acids to be in particular backbone or side-chain conformations. This question has remained unsettled for years because of the discrepancies between different experimental approaches. To address it, I performed all-atom hard-sphere simulations of hydrophobic residues with stereo-chemical constraints and non-attractive steric interactions between non-bonded atoms for ALA, ILE, LEU and VAL dipeptide mimetics. For these hard-sphere MD simulations, I show that transitions between α-helix and β-sheet structures only occur when the bond angle τ(N -Cα - C) >110° , and the probability distribution of bond angles for structures in the `bridge' region of ϕ- ψ space is shifted to larger angles compared to that in other regions. In contrast, the relevant bond-angle distributions obtained from most molecular dynamics packages are broader and shifter to larger values. I encounter similar correlations between bond angles and side-chain dihedral angles. The success of these studies is an argument for re-incorporating local stereochemical constraints into computational protein design methodology.

Why do kids eat healthful food? Perceived benefits of and barriers to healthful eating and physical activity among children and adolescents.

PubMed

O'dea, Jennifer A

2003-04-01

The goal was to have children and adolescents identify and rank the major perceived benefits of and barriers to healthful eating and physical activity and to suggest strategies for overcoming barriers. Semistructured, in-depth focus groups were undertaken using standardized questions and prompts. Students in grades 2 through 11(ages 7 through 17; N=213) from 34 randomly selected schools participated in 38 focus groups. Major benefits of healthful eating included improvements to cognitive and physical performance, fitness, endurance, psychological benefits, physical sensation (feeling good physically), and production of energy. Barriers included convenience, taste, and social factors. Benefits of physical activity included social benefits, enhancement of psychological status, physical sensation, and sports performance. Barriers included a preference for indoor activities, lack of energy and motivation, time constraints, and social factors. Suggested strategies for overcoming barriers included support from parents and school staff, better planning, time management, self-motivation, education, restructuring the physical environment, and greater variety of physical activities.

Rhodium Carbenoid Approach for Introduction of 4-Substituted (Z)-Pent-2-enoates into Sterically Encumbered Pyrroles and Indoles

PubMed Central

Lian, Yajing; Davies, Huw M. L.

2010-01-01

An unusual rhodium-carbenoid approach for introduction of 4-substituted (Z)-pent-2-enoates into sterically encumbered pyrroles and indoles is described. These studies show that (Z)-vinylcarbenoids have a greater tendency than (E)-vinylcarbenoids to react at the vinylogous position of the carbenoid rather than at the carbenoid center. PMID:20121078

Barriers to reporting medication errors and near misses among nurses: A systematic review.

PubMed

Vrbnjak, Dominika; Denieffe, Suzanne; O'Gorman, Claire; Pajnkihar, Majda

2016-11-01

To explore barriers to nurses' reporting of medication errors and near misses in hospital settings. Systematic review. Medline, CINAHL, PubMed and Cochrane Library in addition to Google and Google Scholar and reference lists of relevant studies published in English between January 1981 and April 2015 were searched for relevant qualitative, quantitative or mixed methods empirical studies or unpublished PhD theses. Papers with a primary focus on barriers to reporting medication errors and near misses in nursing were included. The titles and abstracts of the search results were assessed for eligibility and relevance by one of the authors. After retrieval of the full texts, two of the authors independently made decisions concerning the final inclusion and these were validated by the third reviewer. Three authors independently assessed methodological quality of studies. Relevant data were extracted and findings were synthesised using thematic synthesis. From 4038 identified records, 38 studies were included in the synthesis. Findings suggest that organizational barriers such as culture, the reporting system and management behaviour in addition to personal and professional barriers such as fear, accountability and characteristics of nurses are barriers to reporting medication errors. To overcome reported barriers it is necessary to develop a non-blaming, non-punitive and non-fearful learning culture at unit and organizational level. Anonymous, effective, uncomplicated and efficient reporting systems and supportive management behaviour that provides open feedback to nurses is needed. Nurses are accountable for patients' safety, so they need to be educated and skilled in error management. Lack of research into barriers to reporting of near misses' and low awareness of reporting suggests the need for further research and development of educational and management approaches to overcome these barriers. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anti-amyloid precursor protein antibodies inhibit amyloid-β production by steric hindrance

PubMed Central

Thomas, Rhian S.; Liddell, J. Eryl; Kidd, Emma J.

2015-01-01

Summary Cleavage of amyloid precursor protein (APP) by β- and γ-secretases results in the production of amyloid-β (Aβ) in Alzheimer’s disease (AD). We raised two monoclonal antibodies, 2B3 and 2B12, that recognise the β-secretase cleavage site on APP but not Aβ. We hypothesised that these antibodies would reduce Aβ levels via steric hindrance of β-secretase. Both antibodies decreased extracellular Aβ levels from astrocytoma cells, but 2B3 was more potent than 2B12. Levels of soluble sAPPα from the non-amyloidogenic α-secretase pathway and intracellular APP were not affected by either antibody nor were there any effects on cell viability. 2B3 exhibited a higher affinity for APP than 2B12 and its epitope appeared to span the cleavage site while 2B12 bound slightly upstream. Both of these factors probably contribute to its greater effect on Aβ levels. After 60 minutes incubation at pH 4.0, most 2B3 and 2B12 remained bound to their antigen, suggesting that the antibodies will remain bound to APP in the acidic endosomes where β-secretase cleavage probably occurs. Only 2B3 and 2B12, but not control antibodies, inhibited the cleavage of sAPPα by β-secretase in a cell-free assay where effects of antibody internalisation and intracellular degradation were excluded. 2B3 virtually abolished this cleavage. In addition, levels of C-terminal APP fragments, βCTF, generated following β-secretase cleavage, were significantly reduced in cells after incubation with 2B3. These results strongly suggest that anti-cleavage site antibodies can generically reduce Aβ levels via inhibition of β-secretase by steric hindrance and may provide a novel alternative therapy for AD. PMID:21122073

High-throughput rare cell separation from blood samples using steric hindrance and inertial microfluidics.

PubMed

Shen, Shaofei; Ma, Chao; Zhao, Lei; Wang, Yaolei; Wang, Jian-Chun; Xu, Juan; Li, Tianbao; Pang, Long; Wang, Jinyi

2014-07-21

The presence and quantity of rare cells in the bloodstream of cancer patients provide a potentially accessible source for the early detection of invasive cancer and for monitoring the treatment of advanced diseases. The separation of rare cells from peripheral blood, as a "virtual and real-time liquid biopsy", is expected to replace conventional tissue biopsies of metastatic tumors for therapy guidance. However, technical obstacles, similar to looking for a needle in a haystack, have hindered the broad clinical utility of this method. In this study, we developed a multistage microfluidic device for continuous label-free separation and enrichment of rare cells from blood samples based on cell size and deformability. We successfully separated tumor cells (MCF-7 and HeLa cells) and leukemic (K562) cells spiked in diluted whole blood using a unique complementary combination of inertial microfluidics and steric hindrance in a microfluidic system. The processing parameters of the inertial focusing and steric hindrance regions were optimized to achieve high-throughput and high-efficiency separation, significant advantages compared with existing rare cell isolation technologies. The results from experiments with rare cells spiked in 1% hematocrit blood indicated >90% cell recovery at a throughput of 2.24 × 10(7) cells min(-1). The enrichment of rare cells was >2.02 × 10(5)-fold. Thus, this microfluidic system driven by purely hydrodynamic forces has practical potential to be applied either alone or as a sample preparation platform for fundamental studies and clinical applications.

Eliminating Language Barriers Online at European Prisons (ELBEP): A Case-Study

ERIC Educational Resources Information Center

Barkan, M.; Toprak, E.; Kumtepe, A. T.; Kumtepe, E. Genc; Ataizi, M.; Pilanci, H.; Mutlu, M. E.; Kayabas, I.; Kayabas, B. Kip

2011-01-01

ELBEP (Eliminating Language Barriers in European Prisons Through Open and Distance Education Technology) is a multilateral project funded by the European Union (EU) Lifelong Learning, Grundtvig (Adult Education) Programme. It aims to overcome language/communication problems between prison staff and foreign inmates at European prisons via online…

Remote Steric Effect as a Facile Strategy for Improving the Efficiency of Exciplex-Based OLEDs.

PubMed

Hung, Wen-Yi; Wang, Ting-Chih; Chiang, Pin-Yi; Peng, Bo-Ji; Wong, Ken-Tsung

2017-03-01

This work reports a new strategy of introducing remote steric effect onto the electron donor for giving the better performance of the exciplex-based organic light-emitting device (OLED). The bulky triphenylsilyl group (SiPh 3 ) was introduced onto the fluorene bridge of 4,4'-(9H-fluorene-9,9-diyl)bis(N,N-di-p-tolylaniline) (DTAF) to create remote steric interactions for increasing the possibility of effective contacts between electron-donating chromophores and acceptor molecules, rendering the resulting exciplex to have a higher photoluminescence quantum yield (PLQY). The green exciplex device based on DSDTAF:3N-T2T (1:1) as an emitting layer exhibits a low turn-on voltage of 2.0 V, high maximum efficiencies (13.2%, 42.9 cd A -1 , 45.5 lm W -1 ), which are higher than the device employed DTAF (without SiPh 3 groups) (11.6%, 35.3 cd A -1 , 41.3 lm W -1 ) as donor under the same device structure. This strategy was further examined for blue exciplex, where the EQE was enhanced from 9.5% to 12.5% as the electron acceptor PO-T2T mixed with a tert-butyl group substituted carbazole-based donor (CPTBF) as the emitting exciplex in device. This strategy is simple and useful for developing high performance exciplex OLEDs.

Strategies for Overcoming Barriers to Training and Education for Canadians with Disabilities. Lessons in Learning

ERIC Educational Resources Information Center

Canadian Council on Learning, 2009

2009-01-01

If stronger skills and more education are key to greater labour force participation, then it is important to identify critical barriers to education and training for Canadians with disabilities. In 2008, the Canadian Council on Learning's Adult Learning Knowledge Centre funded a "Community Outreach Initiative for Learner's with…

Barriers to cancer screening among Orthodox Jewish women.

PubMed

Tkatch, Rifky; Hudson, Janella; Katz, Anne; Berry-Bobovski, Lisa; Vichich, Jennifer; Eggly, Susan; Penner, Louis A; Albrecht, Terrance L

2014-12-01

The increased risk of genetic cancer mutations for Ashkenazi Jews is well known. However, little is known about the cancer-related health behaviors of a subset of Ashkenazi Jews, Orthodox Jews, who are a very religious and insular group. This study partnered with Rabbinical leadership and community members in an Orthodox Jewish community to investigate barriers to cancer screening in this community. Orthodox Jewish women were recruited to participate in focus groups designed to elicit their perspectives on barriers to cancer screening. A total of five focus groups were conducted, consisting of 3-5 members per group, stratified by age and family history of cancer. Focus groups were audio recorded and transcribed. Transcripts were coded using conventional content analysis. The resulting themes identified as barriers to cancer screening were: preservation of hidden miracles, fate, cost, competing priorities, lack of culturally relevant programming, lack of information, and fear. These results provide a unique perspective on barriers to cancer screening in a high risk but understudied population. Findings from this study may serve to inform culturally appropriate cancer education programs to overcome barriers to screening in this and other similar communities.

Achieving Crossed Strong Barrier Coverage in Wireless Sensor Network.

PubMed

Han, Ruisong; Yang, Wei; Zhang, Li

2018-02-10

Barrier coverage has been widely used to detect intrusions in wireless sensor networks (WSNs). It can fulfill the monitoring task while extending the lifetime of the network. Though barrier coverage in WSNs has been intensively studied in recent years, previous research failed to consider the problem of intrusion in transversal directions. If an intruder knows the deployment configuration of sensor nodes, then there is a high probability that it may traverse the whole target region from particular directions, without being detected. In this paper, we introduce the concept of crossed barrier coverage that can overcome this defect. We prove that the problem of finding the maximum number of crossed barriers is NP-hard and integer linear programming (ILP) is used to formulate the optimization problem. The branch-and-bound algorithm is adopted to determine the maximum number of crossed barriers. In addition, we also propose a multi-round shortest path algorithm (MSPA) to solve the optimization problem, which works heuristically to guarantee efficiency while maintaining near-optimal solutions. Several conventional algorithms for finding the maximum number of disjoint strong barriers are also modified to solve the crossed barrier problem and for the purpose of comparison. Extensive simulation studies demonstrate the effectiveness of MSPA.

Overcoming practical challenges to conducting clinical research in the inpatient stroke rehabilitation setting.

PubMed

Campbell, Grace B; Skidmore, Elizabeth R; Whyte, Ellen M; Matthews, Judith T

2015-10-01

There is a shortage of published empirical studies conducted in acute inpatient stroke rehabilitation, though such studies are greatly needed in order to shed light on the most efficacious inpatient stroke rehabilitation interventions. The inherent challenges of inpatient research may dissuade researchers from undertaking this important work. This paper describes our institution's experience devising practical solutions to research barriers in this setting. Through concentrated efforts to overcome research barriers, such as by cultivating collaborative relationships and capitalizing on unanticipated benefits, we successfully facilitated conduct of five simultaneous inpatient stroke studies. Tangible benefits realized include increased effectiveness of research participant identification and enrollment, novel collaborative projects, innovative clinical care initiatives, and enhanced emotional and practical support for patients and their families. We provide recommendations based on lessons learned during our experience, and discuss benefits of this collaboration for our research participants, clinical staff, and the research team.

Modulated nematic structures induced by chirality and steric polarization

NASA Astrophysics Data System (ADS)

Longa, Lech; PajÄ k, Grzegorz

2016-04-01

What kind of one-dimensional modulated nematic structures (ODMNS) can form nonchiral and chiral bent-core and dimeric materials? Here, using the Landau-de Gennes theory of nematics, extended to account for molecular steric polarization, we study a possibility of formation of ODMNS, both in nonchiral and intrinsically chiral liquid crystalline materials. Besides nematic and cholesteric phases, we find four bulk ODMNS for nonchiral materials, two of which, to the best of our knowledge, have not been reported so far. These two structures are longitudinal (NLP) and transverse (NTP) periodic waves where the polarization field being periodic in one dimension stays parallel and perpendicular, respectively, to the wave vector. The other two phases are the twist-bend nematic phase (NTB) and the splay-bend nematic phase (NSB), but their fine structure appears more complex than that considered so far. The presence of molecular chirality converts nonchiral NTP and NSB into new NTB phases. Surprisingly, the nonchiral NLP phase can stay stable even in the presence of intrinsic chirality.

Steric Restrictions of RISC in RNA Interference Identified with Size-Expanded RNA Nucleobases

PubMed Central

Hernández, Armando R.; Peterson, Larryn W.; Kool, Eric T.

2012-01-01

Understanding the interactions between small interfering RNAs (siRNAs) and the RNA-induced silencing complex (RISC) – the key protein complex of RNA interference (RNAi) – is of great importance to the development of siRNAs with improved biological, and potentially therapeutic, function. Although various chemically modified siRNAs have been reported, relatively few studies with modified nucleobases exist. Here we describe the synthesis and hybridization properties of siRNAs bearing size-expanded RNA (xRNA) nucleobases, and their use as a novel and systematic set of steric probes in RNAi. xRNA nucleobases are expanded by 2.4 Å using benzo-homologation and retain canonical Watson-Crick base-pairing groups. Our data show that the modified siRNA duplexes display small changes in melting temperature (+1.4 to −5.0 °C); substitutions near the center are somewhat destabilizing to the RNA duplex, while substitutions near the ends are stabilizing. RNAi studies in a dual-reporter luciferase assay in HeLa cells revealed that xRNA nucleobases in the antisense strand reduce activity at some central positions near the seed region, but are generally well tolerated near the ends. Most importantly, we observed that xRNA substitutions near the 3′-end increased activity over wild-type siRNAs. The data are analyzed in terms of site-dependent steric effects in RISC. Circular dichroism experiments show that single xRNA substitutions do not significantly distort the native A-form helical structure of the siRNA duplex, and serum stability studies demonstrated that xRNA substitutions protect siRNAs against nuclease degradation. PMID:22646660

E-Learning Barriers and Solutions to Knowledge Management and Transfer

ERIC Educational Resources Information Center

Oye, Nathaniel David; Salleh, Mazleena

2013-01-01

This paper present a systematic overview of barriers and solutions of e-learning in knowledge management (KM) and knowledge transfer (KT) with more focus on organizations. The paper also discusses KT in organizational settings and KT in the field of e-learning. Here, an e-learning initiative shows adaptive solutions to overcome knowledge transfer…

Barriers to Asthma Management for School Nurses: An Integrative Review.

PubMed

Hanley Nadeau, Ellen; Toronto, Coleen E

2016-04-01

Childhood asthma is a growing health concern. Asthma is the most common chronic illness of childhood and a leading cause of emergency room visits, hospitalizations, and school absenteeism. School nurses play a valuable role in asthma management. The purpose of this integrative review is to examine barriers to asthma management for school nurses in the school setting. Findings revealed multiple barriers school nurses encounter in managing asthma. Six themes emerged that included lack of resources and support, insufficient time, communication challenges, limited knowledge, and lack of awareness of school nurses' expertise. Students, parents, primary care physicians, school administration, staff, and school nurses themselves all play a role in constructing barriers to asthma management. There is a need for school nurses and school nurse leaders to focus efforts to develop strategies to overcome barriers to ensure evidence-based, best practice management of asthma in the school setting. © The Author(s) 2015.

Identifying Barriers to Collaboration Between Primary Care and Public Health: Experiences at the Local Level.

PubMed

Pratt, Rebekah; Gyllstrom, Beth; Gearin, Kim; Lange, Carol; Hahn, David; Baldwin, Laura-Mae; VanRaemdonck, Lisa; Nease, Don; Zahner, Susan

Interest is increasing in collaborations between public health and primary care to address the health of a community. Although the understanding of how these collaborations work is growing, little is known about the barriers facing these partners at the local level. The objective of this study was to identify barriers to collaboration between primary care and public health at the local level in 4 states. The study team, which comprised 12 representatives of Practice-Based Research Networks (networks of practitioners interested in conducting research in practice-based settings), identified 40 key informants from the public health and primary care fields in Colorado, Minnesota, Washington State, and Wisconsin. The key informants participated in standardized, semistructured telephone interviews with 8 study team members in 2014 and 2015. Interviews were audio recorded and transcribed verbatim. We analyzed key themes and subthemes by drawing on grounded theory. Primary care and public health participants identified similar barriers to collaboration. Barriers at the institutional level included the challenges of the primary care environment, in which providers feel overwhelmed and resources are tight; the need for systems change; a lack of partnership; and geographic challenges. Barriers to collaboration included mutual awareness, communication, data sharing, capacity, lack of resources, and prioritization of resources. Some barriers to collaboration (eg, changes to health care billing, demands on provider time) require systems change to overcome, whereas others (eg, a lack of shared priorities and mutual awareness) could be addressed through educational approaches, without adding resources or making a systemic change. Overcoming these common barriers may lead to more effective collaboration.

CAI: Overcoming Attitude Barriers.

ERIC Educational Resources Information Center

Netusil, Anton J.; Kockler, Lois H.

During each of two school quarters, approximately 60 college students enrolled in a mathematics course were randomly assigned to an experimental group or a control group. The control group received instruction by the lecture method only; the experimental group received the same instruction, except that six computer-assisted instruction (CAI) units…

Consensus on Bridges for Barriers to Insulin Therapy.

PubMed

Kalra, Sanjay; Ghosal, Samit; Shah, Parag

2017-03-01

Insulin is an effective, safe and well-tolerated drug for glycaemic control. However, there are significant barriers to its use. This consensus statement aims to define these barriers and suggest bridges to overcome them. The consensus statements are based upon deliberations of a meeting held at New Delhi, India on 20 August 2016. The expert group committee reviewed various barriers to insulin use and categorized them into various categories: patient/community-related, physician-related and drug-related. The committee further proposed recommendations, based on published literature and their clinical experience, to address each of these barriers. Barriers (and bridges) can be classified as patient/community, physician/provider, and drug/device. Patient and physician barriers can further be categorized as those related to perceived inadequacy, perceived high cost, and perceived lack of benefit. Drug and device barriers can similarly be classified as those linked with perceived inadequacy, perceived high cost, and perceived lack of tolerability. Such a classification allows diabetes care providers to build appropriate bridges, which in turn facilitate timely insulin usage. Patient related barriers can be bridged by education, support and counselling. Use of modern insulin regimes and social marketing can address barriers related to perceived cost and lack of benefit. Physician related barriers can be resolved by training on various aspects of diabetes care. This will also help to break drug and device barriers, by ensuring appropriate choice of regimes, preparations and delivery devices. The consensus statements provide an easily understandable taxonomic structure of barriers to insulin use. By using a reader-friendly rubric, and by focusing on bridges (rather than barriers alone), it promotes a proactive and positive approach to diabetes management. The consensus statement should serve as a useful pedagogic and clinical tool for diabetes care professionals, and

Healthcare librarians and the delivery of critical appraisal training: barriers to involvement.

PubMed

Maden-Jenkins, Michelle

2011-03-01

  Many healthcare librarians are undertaking training in critical appraisal but a significant number are not cascading the training to their end-users.   To examine the barriers to healthcare librarian involvement in delivering critical appraisal training.   A questionnaire survey of 57 library services across 48 NHS Trust Library Services in north west England followed up with 21 semi-structured interviews.   Two types of barriers were noted: extrinsic barriers (organisational, environmental, training, role expectations) and intrinsic barriers (knowledge, skills, attitude).   These barriers are not mutually exclusive and by overcoming one of them it does not necessarily follow that healthcare librarians will engage in delivering critical appraisal skills training. The challenge lies in developing strategies to deal effectively with these barriers to encourage and support healthcare librarians in the delivery of critical appraisal training at a level at which they feel confident and able. © 2010 The authors. Health Information and Libraries Journal © 2010 Health Libraries Group.

Lis1 regulates dynein by sterically blocking its mechanochemical cycle

PubMed Central

Toropova, Katerina; Zou, Sirui; Roberts, Anthony J; Redwine, William B; Goodman, Brian S; Reck-Peterson, Samara L; Leschziner, Andres E

2014-01-01

Regulation of cytoplasmic dynein's motor activity is essential for diverse eukaryotic functions, including cell division, intracellular transport, and brain development. The dynein regulator Lis1 is known to keep dynein bound to microtubules; however, how this is accomplished mechanistically remains unknown. We have used three-dimensional electron microscopy, single-molecule imaging, biochemistry, and in vivo assays to help establish this mechanism. The three-dimensional structure of the dynein–Lis1 complex shows that binding of Lis1 to dynein's AAA+ ring sterically prevents dynein's main mechanical element, the ‘linker’, from completing its normal conformational cycle. Single-molecule experiments show that eliminating this block by shortening the linker to a point where it can physically bypass Lis1 renders single dynein motors insensitive to regulation by Lis1. Our data reveal that Lis1 keeps dynein in a persistent microtubule-bound state by directly blocking the progression of its mechanochemical cycle. DOI: http://dx.doi.org/10.7554/eLife.03372.001 PMID:25380312

Poliovirus intrahost evolution is required to overcome tissue-specific innate immune responses.

PubMed

Xiao, Yinghong; Dolan, Patrick Timothy; Goldstein, Elizabeth Faul; Li, Min; Farkov, Mikhail; Brodsky, Leonid; Andino, Raul

2017-08-29

RNA viruses, such as poliovirus, have a great evolutionary capacity, allowing them to quickly adapt and overcome challenges encountered during infection. Here we show that poliovirus infection in immune-competent mice requires adaptation to tissue-specific innate immune microenvironments. The ability of the virus to establish robust infection and virulence correlates with its evolutionary capacity. We further identify a region in the multi-functional poliovirus protein 2B as a hotspot for the accumulation of minor alleles that facilitate a more effective suppression of the interferon response. We propose that population genetic dynamics enables poliovirus spread between tissues through optimization of the genetic composition of low frequency variants, which together cooperate to circumvent tissue-specific challenges. Thus, intrahost virus evolution determines pathogenesis, allowing a dynamic regulation of viral functions required to overcome barriers to infection.RNA viruses, such as polioviruses, have a great evolutionary capacity and can adapt quickly during infection. Here, the authors show that poliovirus infection in mice requires adaptation to innate immune microenvironments encountered in different tissues.

Chemoprevention and therapy of mouse mammary carcinomas with doxorubicin encapsulated in sterically stabilized liposomes.

PubMed

Vaage, J; Donovan, D; Loftus, T; Abra, R; Working, P; Huang, A

1994-05-01

The objective of this study was to determine the ability of doxorubicin, encapsulated in sterically stabilized liposomes (Doxil [Liposome Technology, Inc., Menlo Park, CA]), to inhibit the spontaneous development of mammary carcinomas in mice. Monthly prophylactic intravenous injections of 6 mg/kg doses of Doxil were started when retired breeding C3H/He mice were 26 weeks old. Mice that developed a mammary carcinoma were then given weekly intravenous injections of 6 mg/kg doses to determine whether the tumors were susceptible or resistant to Doxil therapy. The monthly injections reduced the incidence of first mammary carcinomas in up to 88-week-old retired breeding C3H/He mice from 65 of 66 (98%) in untreated mice to 22 of 47 (47%) in treated mice. The first 15 mice that developed a mammary tumor while on the prophylactic protocol were then placed on a weekly therapeutic protocol. The therapeutic use of Doxil cured 3 of 15 mice and inhibited the growth of 12 tumors. Drug resistance as a result of treatments was not observed. The mean survival of tumor-bearing mice was extended from 24 days in untreated mice to 87 days in treated mice. Toxic side effects were limited to transient weight loss during the weekly Doxil treatments and to epidermal necrosis and dermal fibrosis due to drug extravasation at the sites of intravenous injections. The authors concluded that doxorubicin in sterically stabilized liposomes deserves to be explored further in comparative studies with free doxorubicin for the prophylaxis and therapy of mammary cancer.

Steric and mass-induced Mediterranean sea level trends from 14 years of altimetry data

NASA Astrophysics Data System (ADS)

Criado-Aldeanueva, Francisco; Del Río Vera, Jorge; García-Lafuente, Jesús

2008-02-01

Long-term series of almost 14 years of altimetry data (1992-2005) have been analysed along with Sea Surface Temperature (SST) and temperature and salinity profiles to investigate sea level trends over the Mediterranean Sea. Although sea level variations are mainly driven by the steric contribution, the mass-induced component plays some role in modulating its oscillation. A spatially averaged positive trend of 2.1 ± 0.6 mm/year has been observed, but a change in sign in 2001 seems to appear. Steric effects (mainly on thermal origin) account for ˜ 55% of sea level trend. Although Mediterranean Sea is a semi-enclosed basin, this value is comparable to that reported for the global ocean. Sea level rise is particularly important in the Levantine basin south of Crete with values up to 10 ± 1 mm/year. Other areas of sea level rise are localised throughout the Levantine basin and in the Adriatic and Alboran Seas, with more moderate values. Sea level drop areas are localised in the Algerian basin, between the Balearic Islands and the African coasts and, particularly, in the Ionian basin. In this area, negative trends as high as - 10 ± 0.8 mm/year are detected mainly due to the mass-induced contribution, which suggests decadal changes of surface circulation. The inferred sea level trends have been correlated with North Atlantic Oscillation (NAO) indices and a low but significant correlation has been detected between sea level in the Levantine and Balearic basins and NAO index.

Barriers to effective feedback in undergraduate medical education: Case study from Saudi Arabia.

PubMed

Alrebish, Saleh Ali

2018-01-01

Students' feedback is an essential source of data for evaluation and improvement of the quality of education. Nonetheless, feedback may be routinely practised for accreditation purposes, and it is considered as a ritual employed by students, which makes its effectiveness questionable. The aim of this study is to explore and analyze the students' perceptions about the importance of feedback and the barriers for effective feedback and suggest proper ways to overcome these barriers. This cross-sectional, anonymous, questionnaire-based study was conducted in the College of Medicine, Qassim University. A total of 299 medical students, composed of 185 male and 114 female, from different levels during December 2015 participated. Mean value, standard deviation, and proportion were used to quantify the quantitative and categorical study and outcome variables. 47% of students responded to the questionnaire with more participation of juniors and females. Half of the students believed that feedback is not important and agreed for the presence of barriers for effective feedback. 5 th level students exhibited higher resistance for participation in feedback, and there was a significant difference between male and female students. Promisingly, most of the participant did not believe the presence cultural barrier for feedback. Saudi medical students are willing to involve in effective feedback. Some barriers that make feedback practised as tokenistic is present. They can be overcome through proper orientation and appropriate closing the loop with response to the feedback declared to students. Further investigation is needed to explore barriers to feedback in higher education settings and help designing an approach to enhance the effectiveness of feedback on a national level.

Parents' barriers and strategies to promote healthy eating among school-age children.

PubMed

Nepper, Martha J; Chai, Weiwen

2016-08-01

The home environment is considered one of the most important settings in regards to the development of healthy eating habits among children. The primary purpose of this study was to explore parents' barriers and strategies in promoting healthy eating in the home. The secondary objective was to determine whether the barriers and strategies parents had were different between healthy weight and overweight/obese school-age children. Semi-structured individual interviews with 14 parents of healthy weight and 11 parents of overweight/obese children (6-12 years) were conducted in family homes from August 2014 to March 2015. Transcripts were recorded and codes and themes were verified by the research team and one qualitative expert. Themes emerging from both parents of healthy weight and overweight/obese children were: 1) Parents are busy and strapped for time; 2) Cost is a barrier in providing healthy food, but parents are resourceful; 3) Children ask for junk food regularly, but parents have strategies to manage; 4) Picky eaters are a challenge but parents know they have to overcome this barrier; and 5) Early exposure to unhealthy eating influences children's food choices but strategies can help. However, parents of overweight/obese children felt a lack of support from their spouses/partners for healthy eating in the home, which was not expressed among parents of healthy weight children. Additionally, barriers and strategies were similar among parents of children from different age groups [6-9 years vs. 10-12 years (pre-adolescents)]. Our results suggest while parents faced some challenges in promoting healthy eating in the home, they utilized several strategies to overcome these barriers, which are valuable for direct intervention to improve home food environment and manage children's weight. Copyright © 2016 Elsevier Ltd. All rights reserved.

Diazo Reagents with Small Steric Footprints for Simultaneous Arming/SAR Studies of Alcohol-Containing Natural Products via O–H Insertion

PubMed Central

Chamni, Supakarn; He, Qing-Li; Dang, Yongjun; Bhat, Shridhar; Liu, Jun O.; Romo, Daniel

2011-01-01

Natural products are essential tools for basic cellular studies leading to the identification of medically relevant protein targets and the discovery of potential therapeutic leads. The development of methods that enable mild and selective derivatization of natural products continues to be of significant interest for mining their information-rich content. Herein, we describe novel diazo reagents for simultaneous arming and structure-activity relationship (SAR) studies of alcohol-containing natural products with a small steric footprint, namely an α-trifluoroethyl (HTFB) substituted reagent. The Rh(II)-catalyzed O–H insertion reaction of several natural products, including the potent translation inhibitor lactimidomycin, was investigated and useful reactivity and both chemo- and site (chemosite) selectivities were observed. Differential binding to the known protein targets of both FK506 and fumagillol was demonstrated, validating the advantage of the smaller steric footprint of trifluoroethyl derivatives. A p-azidophenyl diazo reagent is also described that will prove useful for photoaffinity labeling of low affinity small molecule protein receptors. PMID:21894934

Mentoring women in academic surgery: overcoming institutional barriers to success.

PubMed

Hoover, Eddie L

2006-09-01

Women now comprise 50% of Caucasian matriculants to medical school; 66.6% of African Americans, 48% of Hispanics and 51.3% of Asians beginning medical school are also women. This trend is likely to continue since women now earn 57% of all undergraduate degrees, and they earn more degrees in the health professions and biological sciences than men. Black and Hispanic women now earn 66% and 60% of bachelor's degrees in their respective ethnic groups. Overall, women are concentrated at the lowest faculty ranks at medical schools, with 70% holding the rank of instructor or assistant professor. Women continue to experience difficulty with recruitment, retention, promotion and pay issues compared to men. They also experience additional gender-specific issues, including primary responsibility for rearing families and quality-of-life issues in some specialties, including most of the surgical disciplines. Clearly, there is an evolving population shift at work here; the pool of candidates for medical school faculty positions is likely to be evenly split between men and women for Caucasians, Hispanics and Asians, while the African-American pool is likely heavily weighted in favor of the women. Women are beginning to garner more Latin honors recognition at graduation as well and the definition of the "best and the brightest" is being redefined. Therefore, institutions must continue to identify the barriers that deter women from entering surgery, to develop research tools to understand how to improve the process of developing leadership skills among women and to insure a "buy-in" of their male counterparts when components of the plan are being implemented.

Physical activity and exercise after stoma surgery: overcoming the barriers.

PubMed

Russell, Sarah

2017-03-09

This article presents the results from a large nationwide survey completed in 2016 that investigated the physical health and wellbeing of people living with stomas in the UK. In particular, the survey looked at physical activity and exercise, general attitudes and opinions about exercise, whether or not advice about physical activity had been received and other general questions about parastomal hernia and quality of life. There were 2631 respondents making it one of the largest known surveys to date. The findings were concerning yet unsurprising, highlighting a trend toward inactivity after stoma surgery and a fear of exercise in general. People also seem to have poor knowledge about appropriate activities, with many suggesting that the fear of developing a parastomal hernia is a major barrier to activity. Unsurprisingly, those who have a stoma owing to cancer seem to fare worse, reporting even lower levels of physical activity and worse quality of life compared to those with other conditions. This indicates that people who have a combination of a cancer diagnosis and also a stoma may need more specific or additional support in the longer term. The most concerning finding, however, was that the majority of patients could not recall being given any advice about exercise or physical activity by their nurse or surgeon. While this survey presents some initial findings, it raises questions for further research and work. It also highlights a significantly neglected area in both research and support for stoma patients and the health professionals caring for them.

Barriers and facilitators to senior centers participating in translational research.

PubMed

Felix, Holly C; Adams, Becky; Cornell, Carol E; Fausett, Jennifer K; Krukowski, Rebecca A; Love, ShaRhonda J; Prewitt, T Elaine; West, Delia Smith

2014-01-01

Senior centers are ideal locations to deliver evidence-based health promotion programs to the rapidly growing population of older Americans to help them remain healthy and independent in the community. However, little reported research is conducted in partnership with senior centers; thus, not much is known about barriers and facilitators for senior centers serving as research sites. To fill this gap and potentially accelerate research within senior centers to enhance translation of evidence-based interventions into practice, the present study examined barriers and facilitators of senior centers invited to participate in a cluster-randomized controlled trial. Primary barriers to participation related to staffing and perceived inability to recruit older adult participants meeting research criteria. The primary facilitator was a desire to offer programs that were of interest and beneficial to seniors. Senior centers are interested in participating in research that provides benefit to older adults but may need assistance from researchers to overcome participation barriers. © The Author(s) 2012.

Investigating the mechanisms of surface-bound functional groups in overcoming kinetic barriers to the precipitation of ordered dolomite at low temperature (Invited)

NASA Astrophysics Data System (ADS)

Kenward, P. A.; Roberts, J.; Fowle, D.; Goldstein, R.; Moore, D.; Gonzalez, L. A.

2013-12-01

The mineral dolomite, while abundant in the geologic record, is scarce in modern environments and limited to specific environments, due to kinetic barriers at low temperature (< 50°C). The microbial mediation of dolomite has been extensively studied using numerous microorganisms and disordered dolomite has been synthesized under abiotic conditions. However these studies either yielded disordered dolomite or failed to elucidate the specific mechanism(s) necessary to achieve the precipitation ordered phases of dolomite. Our work [1,2] demonstrates laboratory synthesis of dolomite at 25 °C using microcosms composed of either microbial biomass or abiotic carboxylated polystyrene micro-spheres and fluids with a range of marine-type compositions. We identify the density of surface-bound carboxyl-groups of organic matter as a primary control in ordered dolomite formation at low temperatures under the conditions studied. We hypothesize that surface-bound carboxyl-groups, such as those associated with organic matter or microbial biomass, overcome slow reaction kinetics for dolomite precipitation by dehydrating Mg2+ in an energetically favorable reaction. The precipitation of solid carbonate phases remains the most effective means of permanently sequestering CO2 from the atmosphere. As such, an increased understanding of dolomite kinetics at low temperature affords us the opportunity to apply this mechanism to engineered systems designed to enhance carbon sequestration in environments which do not kinetically favor the formation of carbonate mineral phases. [1] Kenward et al. (2013) AAPG, in press. [2] Roberts et al. (2013) PNAS, in press.

Overcoming barriers to effectiveness in a health care operational environment: building on the lessons of American industry.

PubMed

Zimmerer, L W; Zimmerer, T W; Yasin, M M

1999-01-01

Several of the manufacturing-based philosophies, techniques and tools, such as Total Quality Management (TQM), Continuous Improvement (CI), Business Process Reengineering (BPR) and Time-based Competition (TBC) have been successfully adapted for use within the service sector. Diverse service industries including airlines, insurance, food services and hospitality have increased customer satisfaction and performance through the use of the quality driven, manufacturing-based philosophies. This article explores the reasons for the limited success of TQM/CI, BPR, TBC and benchmarking within the health care industry. Sixteen barriers to change are identified, possible counter-measures to these barriers are outlined and two conceptual frameworks are offered as possible facilitators of change for the health care industry.

Barriers to blood glucose monitoring in a multiethnic community.

PubMed

Zgibor, Janice C; Simmons, David

2002-10-01

We studied a multiethnic community to determine factors associated with blood glucose monitoring (BGM) and to determine the independent association between barriers to diabetes care and BGM. A total of 323 participants (35.6% European, 32.2% Maori, and 32.2% Pacific Islander) from the South Auckland Diabetes Project (free of major complications by self-report) completed a qualitative survey to determine barriers to diabetes care. Five barriers to diabetes care categories were generated including internal psychological (self efficacy/health beliefs), external psychological (psychosocial environment), internal physical (comorbidities/side effects of treatment), external physical (finance/access to care), and educational (knowledge of diabetes/services) barriers. Characteristics associated with BGM greater than or equal to twice weekly were female sex, HbA(1c) >8%, higher diabetes knowledge scores, and insulin use. Multivariate analyses demonstrated that those reporting external physical barriers (OR 0.47, 95% CI 0.26-0.84), external psychological barriers (0.55, 0.30-1.0), and internal psychological barriers (0.56, 0.32-1.0) were less likely to perform BGM independent of ethnicity, insulin use, age, sex, diabetes knowledge, and glycemic control. Further multivariate analyses demonstrated that those reporting external physical barriers, particularly related to personal finance, were less likely to perform BGM. These data demonstrate that patient-reported barriers to diabetes care are associated with BGM, particularly in relation to financial, psychosocial, and self-efficacy issues. Understanding these barriers and overcoming them within the context of the patient's ethnic environment may lead to increased participation in self-care.

Electronic health records: what are the most important barriers?

PubMed

Ayatollahi, Haleh; Mirani, Nader; Haghani, Hamid

2014-01-01

The process of design and adoption of electronic health records may face a number of barriers. This study aimed to compare the importance of the main barriers from the experts' point of views in Iran. This survey study was completed in 2011. The potential participants (62 experts) included faculty members who worked in departments of health information technology and individuals who worked in the Ministry of Health in Iran and were in charge of the development and adoption of electronic health records. No sampling method was used in this study. Data were collected using a Likert-scale questionnaire ranging from 1 to 5. The validity of the questionnaire was established using content and face validity methods, and the reliability was calculated using Cronbach's alpha coefficient. The response rate was 51.6 percent. The participants' perspectives showed that the most important barriers in the process of design and adoption of electronic health records were technical barriers (mean = 3.84). Financial and ethical-legal barriers, with the mean value of 3.80 were other important barriers, and individual and organizational barriers, with the mean values of 3.59 and 3.50 were found to be less important than other barriers from the experts' perspectives. Strategic planning for the creation and adoption of electronic health records in the country, creating a team of experts to assess the potential barriers and develop strategies to eliminate them, and allocating financial resources can help to overcome most important barriers to the adoption of electronic health records.

The conversion to electronic hospital notes at Mayo Clinic. Overcoming barriers and challenges.

PubMed

Andreen, Debra L; Dobie, Linda J; Jasperson, Jan C; Lucas, Thomas A; Wubbenhorst, Cathryn L

2010-01-01

This article describes the conversion to electronic hospital notes at a large, multi-specialty group practice: Mayo Clinic in Rochester, Minnesota. Because of the size of the institution and the barriers to the adoption of electronic notes, the process was a gradual one that took several years. Making a convincing case for change to institutional leaders and maintaining their support was crucial to success. Equally vital was the careful investigation of user requirements and the development of software features that allowed providers to complete their notes quickly in the fast-paced hospital environment. Care providers discovered the value of having immediate access to legible hospital notes throughout the campus and from remote locations.

The Employers' Perspective on Barriers and Facilitators to Employment of People with Intellectual Disability: A Differential Mixed-Method Approach

ERIC Educational Resources Information Center

Kocman, Andreas; Fischer, Linda; Weber, Germain

2018-01-01

Background: Obtaining employment is among the most important ambitions of people with intellectual disability. Progress towards comprehensive inclusive employment is hampered by numerous barriers. Limited research is available on these barriers and strategies to overcome them. Method: A mixed method approach in a sample of 30 HR-managers was used…

Mozambican midwives' views on barriers to quality perinatal care.

PubMed

Pettersson, Karen Odberg; Johansson, Eva; Pelembe, Maria de Fatima M; Dgedge, Clemencia; Christensson, Kyllike

2006-02-01

Our purpose in this study was to explore the midwives' perception of factors obstructing or facilitating their ability to provide quality perinatal care at a central labor ward in Maputo. In-depth interviews were undertaken with 16 midwives and were analyzed according to grounded theory technique. Barriers to provision of quality perinatal care were identified as follows: (i) the unsupportive environment, (ii) nonempowering and limited interaction with women in labor, (iii) a sense of professional inadequacy and inferiority, and (iv) nonappliance of best caring practices. A model based on the midwives' reflections on barriers to quality perinatal care and responses to these were developed. Actions aimed at overcoming the barriers were improvising and identifying areas in need of change. Identified evading actions were holding others accountable and yielding to dysfunction and structural control. In order to improve perinatal care, the midwives need to see themselves as change agents and not as victims of external and internal causal relationships over which they have no influence. It is moreover essential that the midwives chose actions aiming at overcoming barriers to quality perinatal care instead of choosing evading actions, which might jeopardize the health of the unborn and newborn infant. We suggest that local as well as national education programs need to correspond with existing reality, even if they provide knowledge that surpasses the present possibilities in practice. Quality of intrapartum and the immediate newborn care requires a supportive environment, however, which in the context of this study presented such serious obstacles that they need to be addressed on the national level. Structural and administrative changes are difficult to target as these depend on national organization of maternal health care (MHC) services and national health expenditures.

Unfavorable regions in the ramachandran plot: Is it really steric hindrance? The interacting quantum atoms perspective

PubMed Central

Maxwell, Peter I.

2017-01-01

Accurate description of the intrinsic preferences of amino acids is important to consider when developing a biomolecular force field. In this study, we use a modern energy partitioning approach called Interacting Quantum Atoms to inspect the cause of the φ and ψ torsional preferences of three dipeptides (Gly, Val, and Ile). Repeating energy trends at each of the molecular, functional group, and atomic levels are observed across both (1) the three amino acids and (2) the φ/ψ scans in Ramachandran plots. At the molecular level, it is surprisingly electrostatic destabilization that causes the high‐energy regions in the Ramachandran plot, not molecular steric hindrance (related to the intra‐atomic energy). At the functional group and atomic levels, the importance of key peptide atoms (Oi –1, Ci, Ni, Ni +1) and some sidechain hydrogen atoms (Hγ) are identified as responsible for the destabilization seen in the energetically disfavored Ramachandran regions. Consistently, the Oi –1 atoms are particularly important for the explanation of dipeptide intrinsic behavior, where electrostatic and steric destabilization unusually complement one another. The findings suggest that, at least for these dipeptides, it is the peptide group atoms that dominate the intrinsic behavior, more so than the sidechain atoms. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:28841241

Overcoming barriers to health-care access: A qualitative study among African migrants in Guangzhou, China.

PubMed

Lin, Lavinia; Brown, Katherine B; Hall, Brian J; Yu, Fan; Yang, Jingqi; Wang, Jason; Schrock, Joshua M; Bodomo, Adams B; Yang, Ligang; Yang, Bin; Nehl, Eric J; Tucker, Joseph D; Wong, Frank Y

2016-10-01

Guangzhou is China's third most populous city, and the region's burgeoning manufacturing economy has attracted many young African businessmen and entrepreneurs to the city. The aims of this study were to examine strategies that African migrants in Guangzhou have adopted in response to health-care barriers, and explore their perceptions of how to address their needs. Twenty-five semi-structured interviews and two focus groups were conducted among African migrants residing in Guangzhou, China. Facing multiple barriers to care, African migrants have adopted a number of suboptimal and unsustainable approaches to access health care. These included: using their Chinese friends or partners as interpreters, self-medicating, using personal connections to medical doctors, and travelling to home countries or countries that offer English-speaking doctors for health care. Health-care providers and health organisations in Guangzhou have not yet acquired sufficient cultural competence to address the needs of African migrants residing in the city. Introducing linguistically and culturally competent health-care services in communities concentrated with African migrants may better serve the population. With the growing international migration to China, it is essential to develop sustainable approaches to improving health-care access for international migrants, particularly those who are marginalised.

Steric effects in the dynamics of electrolytes at large applied voltages. II. Modified Poisson-Nernst-Planck equations.

PubMed

Kilic, Mustafa Sabri; Bazant, Martin Z; Ajdari, Armand

2007-02-01

In situations involving large potentials or surface charges, the Poisson-Boltzman (PB) equation has shortcomings because it neglects ion-ion interactions and steric effects. This has been widely recognized by the electrochemistry community, leading to the development of various alternative models resulting in different sets "modified PB equations," which have had at least qualitative success in predicting equilibrium ion distributions. On the other hand, the literature is scarce in terms of descriptions of concentration dynamics in these regimes. Here, adapting strategies developed to modify the PB equation, we propose a simple modification of the widely used Poisson-Nernst-Planck (PNP) equations for ionic transport, which at least qualitatively accounts for steric effects. We analyze numerical solutions of these modified PNP equations on the model problem of the charging of a simple electrolyte cell, and compare the outcome to that of the standard PNP equations. Finally, we repeat the asymptotic analysis of Bazant, Thornton, and Ajdari [Phys. Rev. E 70, 021506 (2004)] for this new system of equations to further document the interest and limits of validity of the simpler equivalent electrical circuit models introduced in Part I [Kilic, Bazant, and Ajdari, Phys. Rev. E 75, 021502 (2007)] for such problems.

Beyond the Barrier: Communication in the Root through the Endodermis1

PubMed Central

Robbins, Neil E.; Trontin, Charlotte; Duan, Lina; Dinneny, José R.

2014-01-01

The root endodermis is characterized by the Casparian strip and by the suberin lamellae, two hydrophobic barriers that restrict the free diffusion of molecules between the inner cell layers of the root and the outer environment. The presence of these barriers and the position of the endodermis between the inner and outer parts of the root require that communication between these two domains acts through the endodermis. Recent work on hormone signaling, propagation of calcium waves, and plant-fungal symbiosis has provided evidence in support of the hypothesis that the endodermis acts as a signaling center. The endodermis is also a unique mechanical barrier to organogenesis, which must be overcome through chemical and mechanical cross talk between cell layers to allow for development of new lateral organs while maintaining its barrier functions. In this review, we discuss recent findings regarding these two important aspects of the endodermis. PMID:25125504

Barriers to the conduct of randomised clinical trials within all disease areas.

PubMed

Djurisic, Snezana; Rath, Ana; Gaber, Sabrina; Garattini, Silvio; Bertele, Vittorio; Ngwabyt, Sandra-Nadia; Hivert, Virginie; Neugebauer, Edmund A M; Laville, Martine; Hiesmayr, Michael; Demotes-Mainard, Jacques; Kubiak, Christine; Jakobsen, Janus C; Gluud, Christian

2017-08-01

Randomised clinical trials are key to advancing medical knowledge and to enhancing patient care, but major barriers to their conduct exist. The present paper presents some of these barriers. We performed systematic literature searches and internal European Clinical Research Infrastructure Network (ECRIN) communications during face-to-face meetings and telephone conferences from 2013 to 2017 within the context of the ECRIN Integrating Activity (ECRIN-IA) project. The following barriers to randomised clinical trials were identified: inadequate knowledge of clinical research and trial methodology; lack of funding; excessive monitoring; restrictive privacy law and lack of transparency; complex regulatory requirements; and inadequate infrastructures. There is a need for more pragmatic randomised clinical trials conducted with low risks of systematic and random errors, and multinational cooperation is essential. The present paper presents major barriers to randomised clinical trials. It also underlines the value of using a pan-European-distributed infrastructure to help investigators overcome barriers for multi-country trials in any disease area.

Patient-Reported Outcomes and Survivorship in Radiation Oncology: Overcoming the Cons

PubMed Central

Siddiqui, Farzan; Liu, Arthur K.; Watkins-Bruner, Deborah; Movsas, Benjamin

2014-01-01

Purpose Although patient-reported outcomes (PROs) have become a key component of clinical oncology trials, many challenges exist regarding their optimal application. The goal of this article is to methodically review these barriers and suggest strategies to overcome them. This review will primarily focus on radiation oncology examples, will address issues regarding the “why, how, and what” of PROs, and will provide strategies for difficult problems such as methods for reducing missing data. This review will also address cancer survivorship because it closely relates to PROs. Methods Key articles focusing on PROs, quality of life, and survivorship issues in oncology trials are highlighted, with an emphasis on radiation oncology clinical trials. Publications and Web sites of various governmental and regulatory agencies are also reviewed. Results The study of PROs in clinical oncology trials has become well established. There are guidelines provided by organizations such as the US Food and Drug Administration that clearly indicate the importance of and methodology for studying PROs. Clinical trials in oncology have repeatedly demonstrated the value of studying PROs and suggested ways to overcome some of the key challenges. The Radiation Therapy Oncology Group (RTOG) has led some of these efforts, and their contributions are highlighted. The current state of cancer survivorship guidelines is also discussed. Conclusion The study of PROs presents significant benefits in understanding and treating toxicities and enhancing quality of life; however, challenges remain. Strategies are presented to overcome these hurdles, which will ultimately improve cancer survivorship. PMID:25113760

Barriers to conducting research: A survey of trainees in emergency medicine.

PubMed

Olaussen, Alexander; Jennings, Paul A; O'Reilly, Gerard; Mitra, Biswadev; Cameron, Peter A

2017-04-01

Research underpins evidence-based practice, but there are significant barriers to conducting research relevant to each clinical discipline. Understanding these barriers could allow strategies to reduce their impact. The present study was undertaken to understand specific barriers to research for emergency medicine (EM) trainees. EM trainees attending research short courses were surveyed. Free-text responses were classified into themes and a list of pre-specified potential barriers was used for ranking purposes. The responders (n = 61/90; 67.8%) were young, mostly male with low confidence in leading a research project and limited previous research experience. There were 155 unique barriers identified from 55 respondents, which fitted into nine categories. The most frequently perceived barrier was time (29%), followed by skills (22.6%) and cultural factors (19.4%). Most trainees (n = 54/56, 96.4%) believed that the barriers could be overcome. Strategies suggested included protection of time, mentoring and education, as well as top-down improved research culture. Barriers to research in EM are similar to other specialities and were perceived to be manageable. Reorganisation and refocus of the Australasian College for Emergency Medicine training curriculum may be an option to foster an environment to promote research. © 2017 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.

Evaluating barriers to adopting telemedicine worldwide: A systematic review.

PubMed

Scott Kruse, Clemens; Karem, Priyanka; Shifflett, Kelli; Vegi, Lokesh; Ravi, Karuna; Brooks, Matthew

2018-01-01

Introduction and objective Studies on telemedicine have shown success in reducing the geographical and time obstacles incurred in the receipt of care in traditional modalities with the same or greater effectiveness; however, there are several barriers that need to be addressed in order for telemedicine technology to spread. The aim of this review is to evaluate barriers to adopting telemedicine worldwide through the analysis of published work. Methods The authors conducted a systematic literature review by extracting the data from the Cumulative Index of Nursing and Allied Health Literature (CINAHL) and PubMed (MEDLINE) research databases. The reviewers in this study analysed 30 articles (nine from CINAHL and 21 from Medline) and identified barriers found in the literature. This review followed the checklist from Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009. The reviewers organized the results into one table and five figures that depict the data in different ways, organized by: barrier, country-specific barriers, organization-specific barriers, patient-specific barriers, and medical-staff and programmer-specific barriers. Results The reviewers identified 33 barriers with a frequency of 100 occurrences through the 30 articles. The study identified the issues with technically challenged staff (11%), followed by resistance to change (8%), cost (8%), reimbursement (5%), age of patient (5%), and level of education of patient (5%). All other barriers occurred at or less than 4% of the time. Discussion and conclusions Telemedicine is not yet ubiquitous, and barriers vary widely. The top barriers are technology-specific and could be overcome through training, change-management techniques, and alternating delivery by telemedicine and personal patient-to-provider interaction. The results of this study identify several barriers that could be eliminated by focused policy. Future work should evaluate policy to identify which one to lever to

Barriers to health care for people with hearing loss: a review of the literature.

PubMed

Scheier, Donna B

2009-01-01

Deaf individuals face many barriers when trying to access health care. The reasons why barriers are encountered, difficulties met as a result of the barriers, and ways that health professionals and others working with deaf people can overcome obstacles are included in this review of the literature. A brief summary of Deaf culture and history gives background information to better understand the problems. Misunderstandings by d/Deaf patients and hearing health professionals are addressed, as well as issues related to medical interpreters. This paper aims to make health professionals more aware of the needs and cultural differences that must be considered when providing care to the d/Deaf population.

Overcoming Barriers to Health Care Access: A Qualitative Study among African Migrants in Guangzhou, China

PubMed Central

Lin, Lavinia; Brown, Katherine B.; Hall, Brian J.; Yu, Fan; Yang, Jingqi; Wang, Jason; Schrock, Joshua M.; Bodomo, Adams B.; Yang, Ligang; Yang, Bin; Nehl, Eric J.; Tucker, Joseph D.; Wong, Frank Y.

2015-01-01

Guangzhou is China's third most populous city, and the region's burgeoning manufacturing economy has attracted many young African businessmen and entrepreneurs to the city. The aims of this study were to examine strategies that African migrants in Guangzhou have adopted in response to health care barriers, and explore their perceptions of how to address their needs. Twenty-five semi-structured interviews and two focus groups were conducted among African migrants residing in Guangzhou, China. Facing multiple barriers to care, African migrants have adopted a number of suboptimal and unsustainable approaches to access health care. These included: using their Chinese friends or partners as interpreters, self-medicating, using personal connections to medical doctors, and traveling to home countries or countries that offer English-speaking doctors for health care. Health care providers and health organizations in Guangzhou have not yet acquired sufficient cultural competence to address the needs of African migrants residing in the city. Introducing linguistically and culturally competent health care services in communities concentrated with African migrants may better serve the population. With the growing international migration to China, it is essential to develop sustainable approaches to improving health care access for international migrants, particularly those who are marginalized. PMID:26400191

The barriers to clinical coding in general practice: a literature review.

PubMed

de Lusignan, S

2005-06-01

Clinical coding is variable in UK general practice. The reasons for this remain undefined. This review explains why there are no readily available alternatives to recording structured clinical data and reviews the barriers to recording structured clinical data. Methods used included a literature review of bibliographic databases, university health informatics departments, and national and international medical informatics associations. The results show that the current state of development of computers and data processing means there is no practical alternative to coding data. The identified barriers to clinical coding are: the limitations of the coding systems and terminologies and the skill gap in their use; recording structured data in the consultation takes time and is distracting; the level of motivation of primary care professionals; and the priority within the organization. A taxonomy is proposed to describe the barriers to clinical coding. This can be used to identify barriers to coding and facilitate the development of strategies to overcome them.

Barrier-free communication in maternity care of allophone migrants: BRIDGE study protocol.

PubMed

Origlia Ikhilor, Paola; Hasenberg, Gabriele; Kurth, Elisabeth; Stocker Kalberer, Barbara; Cignacco, Eva; Pehlke-Milde, Jessica

2018-02-01

To describe communication and access barriers encountered by allophone women of different migration backgrounds in the Swiss maternity care services, from the perspective of users, healthcare professionals and intercultural interpreters. In addition to the challenges of maternal adjustment, pregnant migrant women must also deal with an unfamiliar health service system. Some must overcome language barriers and the stress of uncertain residence status. Limited access to maternity care increases perinatal morbidity and mortality. Almost 10% of foreigners speak none of Switzerland's official languages. Factors that facilitate or hinder communication between migrant women and perinatal healthcare professionals are under-studied and must be understood if we are to overcome those barriers in clinical practice. Qualitative exploratory study with quantitative sub-study. Participants will be drawn from German to speaking regions of Switzerland. We will conduct focus group discussions and semi-structured interviews with users in their own language (Albanian and Tigrinya) and with healthcare professionals and intercultural interpreters (March-June 2016), then perform Thematic Analysis on the data. In the sub-study, midwives will report their experience of using a telephone interpreting service during postnatal home visits in a questionnaire (October 2013-March 2016). Data will be analysed with descriptive statistics. Our study will reveal patterns in communications between allophone migrant women and healthcare providers and communication barriers. By incorporating multiple perspectives, we will describe the challenges all parties face. Our results will inform those who draft recommendations to improve provision of maternity care to allophone women and their families. ClinicalTrials.gov ID: BernUAS NCT02695316. © 2017 John Wiley & Sons Ltd.

Do "trainee-centered ward rounds" help overcome barriers to learning and improve the learning satisfaction of junior doctors in the workplace?

PubMed

Acharya, Vikas; Reyahi, Amir; Amis, Samuel M; Mansour, Sami

2015-01-01

Ward rounds are widely considered an underutilized resource with regard to medical education, and therefore, a project was undertaken to assess if the initiation of "trainee-centered ward rounds" would help improve the confidence, knowledge acquisition, and workplace satisfaction of junior doctors in the clinical environment. Data were collated from junior doctors, registrar grade doctors, and consultants working in the delivery suite at Luton and Dunstable University Hospital in Luton over a 4-week period in March-April 2013. A review of the relevant literature was also undertaken. This pilot study found that despite the reservations around time constraints held by both junior and senior clinicians alike, feedback following the intervention was largely positive. The junior doctors enjoyed having a defined role and responsibility during the ward round and felt they benefited from their senior colleagues' feedback. Both seniors and junior colleagues agreed that discussing learning objectives prior to commencing the round was beneficial and made the round more learner-orientated; this enabled maximal learner-focused outcomes to be addressed and met. The juniors were generally encouraged to participate more during the round and the consultants endeavored to narrate their decision-making, both were measures that led to greater satisfaction of both parties. This was in keeping with the concept of "Legitimate peripheral participation" as described by Lave and Wenger. Overall, trainee-centered ward rounds did appear to be effective in overcoming some of the traditional barriers to teaching in the ward environment, although further work to formalize and quantify these findings, as well as using greater sample sizes from different hospital departments and the inclusion of a control group, is needed.

Group Qigong for Adolescent Inpatients with Anorexia Nervosa: Incentives and Barriers

PubMed Central

Gueguen, Juliette; Piot, Marie-Aude; Orri, Massimiliano; Gutierre, Andrea; Le Moan, Jocelyne; Berthoz, Sylvie; Falissard, Bruno; Godart, Nathalie

2017-01-01

Background Qigong is a mind-body intervention focusing on interoceptive awareness that appears to be a promising approach in anorexia nervosa (AN). In 2008, as part of our multidimensional treatment program for adolescent inpatients with AN, we began a weekly qigong workshop that turned out to be popular among our adolescent patients. Moreover psychiatrists perceived clinical benefits that deserved further exploration. Methods and findings A qualitative study therefore sought to obtain a deeper understanding of how young patients with severe AN experience qigong and to determine the incentives and barriers to adherence to qigong, to understanding its meaning, and to applying it in other contexts. Data were collected through 16 individual semi-structured face-to-face interviews and analyzed with the interpretative phenomenological analysis method. Eleven themes emerged from the analysis, categorized in 3 superordinate themes describing the incentives and barriers related to the patients themselves (individual dimension), to others (relational dimension), and to the setting (organizational dimension). Individual dimensions associated with AN (such as excessive exercise and mind-body cleavage) may curb adherence, whereas relational and organizational dimensions appear to provide incentives to join the activity in the first place but may also limit its post-discharge continuation. Once barriers are overcome, patients reported positive effects: satisfaction associated with relaxation and with the experience of mind-body integration. Conclusions Qigong appears to be an interesting therapeutic tool that may potentiate psychotherapy and contribute to the recovery process of patients with AN. Further analysis of the best time window for initiating qigong and of its place in overall management might help to overcome some of the barriers, limit the risks, and maximize its benefits. PMID:28152083

Unfavorable regions in the ramachandran plot: Is it really steric hindrance? The interacting quantum atoms perspective.

PubMed

Maxwell, Peter I; Popelier, Paul L A

2017-11-05

Accurate description of the intrinsic preferences of amino acids is important to consider when developing a biomolecular force field. In this study, we use a modern energy partitioning approach called Interacting Quantum Atoms to inspect the cause of the φ and ψ torsional preferences of three dipeptides (Gly, Val, and Ile). Repeating energy trends at each of the molecular, functional group, and atomic levels are observed across both (1) the three amino acids and (2) the φ/ψ scans in Ramachandran plots. At the molecular level, it is surprisingly electrostatic destabilization that causes the high-energy regions in the Ramachandran plot, not molecular steric hindrance (related to the intra-atomic energy). At the functional group and atomic levels, the importance of key peptide atoms (O i -1 , C i , N i , N i +1 ) and some sidechain hydrogen atoms (H γ ) are identified as responsible for the destabilization seen in the energetically disfavored Ramachandran regions. Consistently, the O i -1 atoms are particularly important for the explanation of dipeptide intrinsic behavior, where electrostatic and steric destabilization unusually complement one another. The findings suggest that, at least for these dipeptides, it is the peptide group atoms that dominate the intrinsic behavior, more so than the sidechain atoms. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. © 2017 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

Gauche effect in 1,2-difluoroethane. Hyperconjugation, bent bonds, steric repulsion.

PubMed

Goodman, Lionel; Gu, Hongbing; Pophristic, Vojislava

2005-02-17

Natural bond orbital deletion calculations show that whereas the gauche preference arises from vicinal hyperconjugative interaction between anti C-H bonds and C-F* antibonds, the cis C-H/C-F* interactions are substantial (approximately 25% of the anti interaction). The established significantly >60 degrees FCCF dihedral angle for the equilibrium conformer can then be rationalized in terms of the hyperconjugation model alone by taking into account both anti interactions that maximize near 60 degrees and the smaller cis interactions that maximize at a much larger dihedral angle. This explanation does not invoke repulsive forces to rationalize the 72 degrees equilibrium conformer angle. The relative minimum energy for the trans conformer is the consequence of a balance between decreasing hyperconjugative stabilization and decreasing steric destabilization as the FCCF torsional angle approaches 180 degrees . The torsional coordinate is predicted to be strongly contaminated by CCF bending, with the result that approximately half of the trans --> gauche stabilization energy stems from mode coupling.

Barriers to GPs' use of evidence-based medicine: a systematic review

PubMed Central

Zwolsman, Sandra; te Pas, Ellen; Hooft, Lotty; Waard, Margreet Wieringa-de; van Dijk, Nynke

2012-01-01

Background GPs report various barriers to the use and practice of evidence-based medicine (EBM). A review of research on these barriers may help solve problems regarding the uptake of evidence in clinical outpatient practice. Aim To determine the barriers encountered by GPs in the practice of EBM and to come up with solutions to the barriers identified. Design A systematic review of the literature. Method The following databases were searched: MEDLINE® (PubMed®), Embase, CINAHL®, ERIC, and the Cochrane Library, until February 2011. Primary studies (all methods, all languages) that explore the barriers that GPs encounter in the practice of EBM were included. Results A total of 14 700 articles were identified, of which 22 fulfilled all inclusion criteria. Of the latter, nine concerned qualitative, 12 concerned quantitative, and one concerned both qualitative and quantitative research methods. The barriers described in the articles cover the categories: evidence (including the accompanying EBM steps), the GP’s preferences (experience, expertise, education), and the patient’s preferences. The particular GP setting also has important barriers to the use of EBM. Barriers found in this review, among others, include lack of time, EBM skills, and available evidence; patient-related factors; and the attitude of the GP. Conclusion Various barriers are encountered when using EBM in GP practice. Interventions that help GPs to overcome these barriers are needed, both within EBM education and in clinical practice. PMID:22781999

Overcoming Spatial and Temporal Barriers to Public Access Defibrillators Via Optimization

PubMed Central

Sun, Christopher L. F.; Demirtas, Derya; Brooks, Steven C.; Morrison, Laurie J.; Chan, Timothy C.Y.

2016-01-01

BACKGROUND Immediate access to an automated external defibrillator (AED) increases the chance of survival from out-of-hospital cardiac arrest (OHCA). Current deployment usually considers spatial AED access, assuming AEDs are available 24 h a day. OBJECTIVES We sought to develop an optimization model for AED deployment, accounting for spatial and temporal accessibility, to evaluate if OHCA coverage would improve compared to deployment based on spatial accessibility alone. METHODS This was a retrospective population-based cohort study using data from the Toronto Regional RescuNET cardiac arrest database. We identified all nontraumatic public-location OHCAs in Toronto, Canada (January 2006 through August 2014) and obtained a list of registered AEDs (March 2015) from Toronto emergency medical services. We quantified coverage loss due to limited temporal access by comparing the number of OHCAs that occurred within 100 meters of a registered AED (assumed 24/7 coverage) with the number that occurred both within 100 meters of a registered AED and when the AED was available (actual coverage). We then developed a spatiotemporal optimization model that determined AED locations to maximize OHCA actual coverage and overcome the reported coverage loss. We computed the coverage gain between the spatiotemporal model and a spatial-only model using 10-fold cross-validation. RESULTS We identified 2,440 atraumatic public OHCAs and 737 registered AED locations. A total of 451 OHCAs were covered by registered AEDs under assumed 24/7 coverage, and 354 OHCAs under actual coverage, representing a coverage loss of 21.5% (p < 0.001). Using the spatiotemporal model to optimize AED deployment, a 25.3% relative increase in actual coverage was achieved over the spatial-only approach (p < 0.001). CONCLUSIONS One in 5 OHCAs occurred near an inaccessible AED at the time of the OHCA. Potential AED use was significantly improved with a spatiotemporal optimization model guiding deployment. PMID

Barriers to Diagnosis Access for Chagas Disease in Colombia

PubMed Central

Toquica Gahona, Christian Camilo; Rodríguez Hernández, Jorge Martín

2018-01-01

Chagas disease is the leading cause of nonischemic cardiomyopathy in Latin America. Timely access to diagnosis and trypanocidal treatment and preventive tools for millions of infected people continues to be a challenge. The purpose of this study was to identify potential barriers for the diagnosis of Chagas disease in Colombia from the perspective of healthcare providers. Using a simultaneous mixed-methods study design, we analyzed trends in access to screening and diagnosis for Chagas disease in Colombia and assessed the national barriers to access. The main barriers to access at the national level included a limited governmental public health infrastructure for the diagnosis of Chagas disease and limited physician awareness and knowledge of the disease. Data indicate that 1.5% of total expected cases based on national prevalence estimates were reported. Few public health laboratories have the capacity to perform complementary tests for the diagnosis of Chagas disease and almost 6 months elapse between the requests of the tests and the confirmation of the disease. This study shows that infected people must overcome a number of barriers to achieve diagnosis. Reducing barriers to early diagnosis of Chagas disease is an important goal in the fight against the disease. PMID:29568648

Steric effects in the design of Co-Schiff base complexes for the catalytic oxidation of lignin models to para-benzoquinones

Treesearch

Berenger Biannic; Joseph J. Bozell; Thomas Elder

2014-01-01

New Co-Schiff base complexes that incorporate a sterically hindered ligand and an intramolecular bulky piperazine base in close proximity to the Co center are synthesized. Their utility as catalysts for the oxidation of para-substituted lignin model phenols with molecular oxygen is examined. Syringyl and guaiacyl alcohol, as models of S and G units in lignin, are...

Compound design guidelines for evading the efflux and permeation barriers of Escherichia coli with the oxazolidinone class of antibacterials: Test case for a general approach to improving whole cell Gram-negative activity.

PubMed

Spaulding, Andrew; Takrouri, Khuloud; Mahalingam, Pornachandran; Cleary, Dillon C; Cooper, Harold D; Zucchi, Paola; Tear, Westley; Koleva, Bilyana; Beuning, Penny J; Hirsch, Elizabeth B; Aggen, James B

2017-12-01

Previously we reported the results from an effort to improve Gram-negative antibacterial activity in the oxazolidinone class of antibiotics via a systematic medicinal chemistry campaign focused entirely on C-ring modifications. In that series we set about testing if the efflux and permeation barriers intrinsic to the outer membrane of Escherichia coli could be rationally overcome by designing analogs to reside in specific property limits associated with Gram-negative activity: i) low MW (<400), ii) high polarity (clogD 7.4 <1), and iii) zwitterionic character at pH 7.4. Indeed, we observed that only analogs residing within these limits were able to overcome these barriers. Herein we report the results from a parallel effort where we explored structural changes throughout all three rings in the scaffold for the same purpose. Compounds were tested against a diagnostic MIC panel of Escherichia coli and Staphylococcus aureus strains to determine the impact of combining structural modifications in overcoming the OM barriers and in bridging the potency gap between the species. The results demonstrated that distributing the charge-carrying moieties across two rings was also beneficial for avoidance of the outer membrane barriers. Importantly, analysis of the structure-permeation relationship (SPR) obtained from this and the prior study indicated that in addition to MW, polarity, and zwitterionic character, having ≤4 rotatable bonds is also associated with evasion of the OM barriers. These combined results provide the medicinal chemist with a framework and strategy for overcoming the OM barriers in GNB in antibacterial drug discovery efforts. Copyright © 2017. Published by Elsevier Ltd.

Confronting Barriers, Creating Solutions: Parental Leave for Junior Colleagues

NASA Astrophysics Data System (ADS)

Helfand, David J.

2013-01-01

Barriers to instituting parental leave policies for graduate students and postdoctoral fellows are present at the departmental, university/institute, and federal levels. Within departments, collegial persuasion involving both those affected and senior leadership can be successful in overcoming sociological resistance, although financial constraints may be harder to surmount. Universities are constrained by internal policies and the structure of their fringe benefits pools which are in turn limited by reimbursement rates that must be negotiated with their federal oversight agencies. Federal effort-reporting rules also complicate the situation. I will describe the type of creative solutions that can work at the departmental level, as well as discussing the actions the Society is pursuing in an attempt to lower the external barriers to local action.

The nanometre-scale physiology of bone: steric modelling and scanning transmission electron microscopy of collagen–mineral structure

PubMed Central

Alexander, Benjamin; Daulton, Tyrone L.; Genin, Guy M.; Lipner, Justin; Pasteris, Jill D.; Wopenka, Brigitte; Thomopoulos, Stavros

2012-01-01

The nanometre-scale structure of collagen and bioapatite within bone establishes bone's physical properties, including strength and toughness. However, the nanostructural organization within bone is not well known and is debated. Widely accepted models hypothesize that apatite mineral (‘bioapatite’) is present predominantly inside collagen fibrils: in ‘gap channels’ between abutting collagen molecules, and in ‘intermolecular spaces’ between adjacent collagen molecules. However, recent studies report evidence of substantial extrafibrillar bioapatite, challenging this hypothesis. We studied the nanostructure of bioapatite and collagen in mouse bones by scanning transmission electron microscopy (STEM) using electron energy loss spectroscopy and high-angle annular dark-field imaging. Additionally, we developed a steric model to estimate the packing density of bioapatite within gap channels. Our steric model and STEM results constrain the fraction of total bioapatite in bone that is distributed within fibrils at less than or equal to 0.42 inside gap channels and less than or equal to 0.28 inside intermolecular overlap regions. Therefore, a significant fraction of bone's bioapatite (greater than or equal to 0.3) must be external to the fibrils. Furthermore, we observe extrafibrillar bioapatite between non-mineralized collagen fibrils, suggesting that initial bioapatite nucleation and growth are not confined to the gap channels as hypothesized in some models. These results have important implications for the mechanics of partially mineralized and developing tissues. PMID:22345156

A stapled BIM peptide overcomes apoptotic resistance in hematologic cancers

PubMed Central

LaBelle, James L.; Katz, Samuel G.; Bird, Gregory H.; Gavathiotis, Evripidis; Stewart, Michelle L.; Lawrence, Chelsea; Fisher, Jill K.; Godes, Marina; Pitter, Kenneth; Kung, Andrew L.; Walensky, Loren D.

2012-01-01

Cancer cells subvert the natural balance between cellular life and death, achieving immortality through pathologic enforcement of survival pathways and blockade of cell death mechanisms. Pro-apoptotic BCL-2 family proteins are frequently disarmed in relapsed and refractory cancer through genetic deletion or interaction-based neutralization by overexpressed antiapoptotic proteins, resulting in resistance to chemotherapy and radiation treatments. New pharmacologic strategies are urgently needed to overcome these formidable apoptotic blockades. We harnessed the natural killing activity of BCL-2–interacting mediator of cell death (BIM), which contains one of the most potent BH3 death domains of the BCL-2 protein family, to restore BH3-dependent cell death in resistant hematologic cancers. A hydrocarbon-stapled peptide modeled after the BIM BH3 helix broadly targeted BCL-2 family proteins with high affinity, blocked inhibitory antiapoptotic interactions, directly triggered proapoptotic activity, and induced dose-responsive and BH3 sequence–specific cell death of hematologic cancer cells. The therapeutic potential of stapled BIM BH3 was highlighted by the selective activation of cell death in the aberrant lymphoid infiltrates of mice reconstituted with BIM-deficient bone marrow and in a human AML xenograft model. Thus, we found that broad and multimodal targeting of the BCL-2 family pathway can overcome pathologic barriers to cell death. PMID:22622039

Persisting Barriers to Employment for Recently Housed Adults with Mental Illness Who Were Homeless.

PubMed

Poremski, Daniel; Woodhall-Melnik, Julia; Lemieux, Ashley J; Stergiopoulos, Vicky

2016-02-01

Adults with mental illness who are homeless experience multiple barriers to employment, contributing to difficulties securing and maintaining housing. Housing First programs provide quick, low-barrier access to housing and support services for this population, but their success in improving employment outcomes has been limited. Supported employment interventions may augment Housing First programs and address barriers to employment for homeless adults with mental illness. The present paper presents data from qualitative interviews to shed light on the persisting barriers to employment among people formerly homeless. Once housed, barriers to employment persisted, including the following: (1) worries about disclosing sensitive information, (2) fluctuating motivation, (3) continued substance use, and (4) fears about re-experiencing homelessness-related trauma. Nevertheless, participants reported that their experiences of homelessness helped them develop interpersonal strength and resilience. Discussing barriers with an employment specialist helps participants develop strategies to overcome them, but employment specialists must be sensitive to specific homelessness-related experiences that may not be immediately evident. Supported housing was insufficient to help people return to employment. Supported employment may help people return to work by addressing persisting barriers.

Barriers to diagnosis and treatment of depression: voices from a rural African-American faith community.

PubMed

Bryant, Keneshia; Greer-Williams, Nancy; Willis, Nathaniel; Hartwig, Mary

2013-07-01

Mental health disparities exist for rural African-Americans regarding the early detection of depression and its effective treatment. Disparities that are evident in rural communities include limited mental health resources and the stigma of depression. The faith community has a long-standing history of being the initial source of help to those who experience depression. The purpose of this qualitative study was to examine how rural African-American faith communities view the barriers to diagnosis and treatment of depression. A convenience sample of 24 persons (N = 24) participated in focus groups and interviews. Four internal barriers were identified: personal business, "mindset," "denial," and "put on a front." Additionally,four external barriers were identified: "spiritual beliefs," "lack of medical resources," "lack of education about depression," and "stigma." The identified barriers supported the results from previous studies, but they also highlighted other less acknowledged barriers. In conclusion, interventions are needed to overcome these barriers in order to eliminate the depression disparities experienced by this population.

Structural barriers to ART adherence in Southern Africa: challenges and potential ways forward

PubMed Central

KAGEE, A.; REMIEN, R.H.; BERKMAN, A.; HOFFMAN, S.; CAMPOS, L.; SWARTZ, L.

2010-01-01

Structural barriers to antiretroviral treatment (ART) adherence are economic, institutional, political and cultural factors, that collectively influence the extent to which persons living with HIV follow their medication regimens. We identify three sets of structural barriers to ART adherence that are salient in Southern Africa: poverty-related, institutional, and political and cultural. Examples of poverty-related barriers are competing demands in the context of resource-constrained settings, the lack of transport infrastructure, food insecurity, the role of disability grants and poor social support. Examples of institutional factors are logistical barriers, overburdened health care facilities, limited access to mental health services and difficulties in ensuring adequate counseling. Examples of political and cultural barriers are controversies in the provision of treatment for AIDS, migration, traditional beliefs about HIV and AIDS, poor health literacy and gender inequalities. In forging a way forward, we identify ways in which individuals, communities and health care systems may overcome some of these structural barriers. Finally, we make recommendations for further research on structural barriers to ART adherence. In all likelihood, enhancing adherence to ART requires the efforts of a variety of disciplines, including public health, psychology, anthropology, sociology and medicine. PMID:20509066

Pediatrician-experienced barriers in the medical care for refugee children in the Netherlands.

PubMed

Baauw, A; Rosiek, S; Slattery, B; Chinapaw, M; van Hensbroek, M Boele; van Goudoever, J B; Kist-van Holthe, J

2018-04-20

Pediatricians in the Netherlands have been confronted with high numbers of refugee children in their daily practice. Refugee children have been recognized as an at-risk population because they may have an increased burden of physical and mental health conditions, and their caretakers may experience barriers in gaining access to the Dutch health care system. The aim of the study was to gain insight into the barriers in the health care for refugee children perceived by pediatricians by analyzing logistical problems reported through the Dutch Pediatric Surveillance Unit, an online system where pediatricians can report predefined conditions. Pediatricians reported 68 cases of barriers in health care ranging from mild to severe impact on the health outcome of refugee children, reported from November 2015 till January 2017. Frequent relocation of children between asylum seeker centers was mentioned in 28 of the reports on lack of continuity of care. Unknown medical history (21/68) and poor handoffs of medical records resulting in poor communication between health professionals (17/68) contributed to barriers to provide good medical care for refugee children, as did poor health literacy (17/68) and cultural differences (5/68). Frequent relocations and the unknown medical history were reported most frequently as barriers impacting the delivery of health care to refugee children. To overcome these barriers, the Committee of International Child Health of the Dutch Society of Pediatrics recommends stopping the frequent relocations, improving medical assessment upon entry in the Netherlands, improving handoff of medical records, and improving the health literacy of refugee children and their families. What is Known: • Pediatricians in the Netherlands are confronted with high numbers of refugee children • Refugee children represent a population that is especially at risk due to their increased burden of physical and mental health conditions What is New: • Refugee children

Perceived Barriers, Facilitators and Benefits for Regular Physical Activity and Exercise in Patients with Rheumatoid Arthritis: A Review of the Literature.

PubMed

Veldhuijzen van Zanten, Jet J C S; Rouse, Peter C; Hale, Elizabeth D; Ntoumanis, Nikos; Metsios, George S; Duda, Joan L; Kitas, George D

2015-10-01

Rheumatoid arthritis (RA) is an autoimmune disease, which not only affects the joints but can also impact on general well-being and risk for cardiovascular disease. Regular physical activity and exercise in patients with RA have numerous health benefits. Nevertheless, the majority of patients with RA are physically inactive. This indicates that people with RA might experience additional or more severe barriers to physical activity or exercise than the general population. This narrative review provides an overview of perceived barriers, benefits and facilitators of physical activity and exercise in RA. Databases were searched for articles published until September 2014 using the terms 'rheumatoid arthritis', 'physical activity', 'exercise', 'barriers', 'facilitators', 'benefits', 'motivation', 'motivators' and 'enablers'. Similarities were found between disease-specific barriers and benefits of physical activity and exercise, e.g. pain and fatigue are frequently mentioned as barriers, but reductions in pain and fatigue are perceived benefits of physical activity and exercise. Even though exercise does not influence the existence of barriers, physically active patients appear to be more capable of overcoming them. Therefore, exercise programmes should enhance self-efficacy for exercise in order to achieve long-term physical activity and exercise behaviour. Encouragement from health professionals and friends/family are facilitators for physical activity and exercise. There is a need for interventions that support RA patients in overcoming barriers to physical activity and exercise and help sustain this important health behaviour.

Barriers to Treatment Among African Americans with Obsessive-Compulsive Disorder

PubMed Central

Williams, M.T.; Domanico, J.; Marques, L.; Leblanc, N.J.; Turkheimer, E.

2012-01-01

African Americans are underrepresented in OCD treatment centers and less likely to experience a remission of symptoms. This study examines the barriers that prevent African Americans with OCD from receiving treatment. Seventy-one adult African Americans with OCD were recruited and administered the modified Barriers to Treatment Participation Scale (BTPS) and the Barriers to Treatment Questionnaire (BTQ). Comparing the BTQ between a European American Internet sample (N=108) and the African American OCD sample (N=71) revealed barriers unique to African Americans, including not knowing where to find help and concerns about discrimination. A Mokken Scale Analysis of the BTPS in the African American participants identified seven major barriers, including the cost of treatment, stigma, fears of therapy, believing that the clinician will be unable to help, feeling no need for treatment, and treatment logistics (being too busy or treatment being too inconvenient). Pearson and point-biserial correlations of the scales and demographic and psychological variables were conducted. Significant relationships emerged between age, gender, income, education, insurance status, and ethnic affirmation/belonging among several of the Mokken scales. A one-way ANOVA demonstrated that concerns about cost were significantly greater for those without insurance, versus those with public or private plans. Suggestions for overcoming barriers are presented, including community education, affordable treatment options, and increasing cultural competence among mental health providers. PMID:22410094

Evaluation of two sterically directed attachments of biomolecules on a coaxial nanofibre membrane to improve the development of optical biosensors.

PubMed

Ramon-Marquez, Teresa; Medina-Castillo, Antonio L; Fernandez-Gutierrez, Alberto; Fernandez-Sanchez, Jorge F

2018-09-01

In this study, we have optimised the sterically directed attachment of biomolecules on the surface of coaxial membranes prepared by co-electrospinning which have been proved to be a material with very high performance for the development of biosensors with optical oxygen transduction. Uricase has been used as model enzyme. Two sterically directed strategies: a) covalent attachment via maleimide, and b) affinity bonding via biotin-streptavidin interaction, have been tested in order to preserve the enzymatic activity of uricase and to improve the analytical figures of merits on the determination of uric acid. The best results were obtained with biotin-streptavidin affinity interaction and using a biotinylation reagent containing a polyethylene glycol chain. The developed biosensor showed high sensitivity towards uric acid with a detection limit of 0.5 µM, a quantification limit of 1.8 µM and linear range from 1.8 to 250 µM. The applicability of the membrane as biosensor with optical oxygen transduction was proved by determining uric acid in serum samples. The obtained results showed a good correlation (0.999) with those obtained by an external reference laboratory. Copyright © 2018 Elsevier B.V. All rights reserved.

An assessment of the barriers to accessing the Basic Package of Health Services (BPHS) in Afghanistan: was the BPHS a success?

PubMed

Frost, Alexandra; Wilkinson, Matthew; Boyle, Peter; Patel, Preeti; Sullivan, Richard

2016-11-15

Afghanistan is one of the most fragile and conflict-affected countries in the world. It has experienced almost uninterrupted conflict for the last thirty years, with the present conflict now lasting over a decade. With no history of a functioning healthcare system, the creation of the Basic Package of Health Services (BPHS) in 2003 was a response to Afghanistan's dire health needs following decades of war. Its objective was to provide a bare minimum of essential health services, which could be scaled up rapidly through contracting mechanisms with Non-Governmental Organisations (NGOs). The central thesis of this article is that, despite the good intentions of the BPHS, not enough has been done to overcome the barriers to accessing its services. This analysis, enabled through a review of the existing literature, identifies and categorises these barriers into the three access dimensions of: acceptability, affordability and availability. As each of these is explored individually, analysis will show the extent to which these barriers to access are a critical issue, consider the underlying reasons for their existence and evaluate the efforts to overcome these barriers. Understanding these barriers and the policies that have been implemented to address them is critical to the future of health system strengthening in Afghanistan.

Nurse Scientists Overcoming Challenges to Lead Transdisciplinary Research Teams

PubMed Central

Kneipp, Shawn M.; Gilleskie, Donna; Sheely, Amanda; Schwartz, Todd; Gilmore, Robert M.; Atkinson, Daryl

2017-01-01

Increasingly, scientific funding agencies are requiring that researchers move toward an integrated, transdisciplinary team science paradigm. While the barriers to and rewards of conducting this type of research have been discussed in the literature, examples of how nurse investigators have led these teams to reconcile the differences in theoretical, methodological, and/or analytic perspectives that inevitably exist are lacking. In this article, we describe these developmental trajectory challenges through a case study of one transdisciplinary team, focusing on team member characteristics and the leadership tasks associated with successful transdisciplinary science teams in the literature. Specifically, we describe how overcoming these challenges has been essential to examining the complex, and potentially cumulative effects that key intersections between legal, social welfare, and labor market systems may have on the health of disadvantaged women. Finally, we discuss this difficult, but rewarding work within the context of lessons learned and transdisciplinary team research in relation to the future of nursing science. PMID:25015404

Mechanical Barriers Restrict Invasion of Herpes Simplex Virus 1 into Human Oral Mucosa

PubMed Central

Thier, Katharina; Petermann, Philipp; Rahn, Elena; Rothamel, Daniel; Bloch, Wilhelm

2017-01-01

ABSTRACT Oral mucosa is one of the main target tissues of the human pathogen herpes simplex virus 1 (HSV-1). How the virus overcomes the protective epithelial barriers and penetrates the tissue to reach its receptors and initiate infection is still unclear. Here, we established an ex vivo infection assay with human oral mucosa that allows viral entry studies in a natural target tissue. The focus was on the susceptibility of keratinocytes in the epithelium and the characterization of cellular receptors that mediate viral entry. Upon ex vivo infection of gingiva or vestibular mucosa, we observed that intact human mucosa samples were protected from viral invasion. In contrast, the basal layer of the oral epithelium was efficiently invaded once the connective tissue and the basement membrane were removed. Later during infection, HSV-1 spread from basal keratinocytes to upper layers, demonstrating the susceptibility of the stratified squamous epithelium to HSV-1. The analysis of potential receptors revealed nectin-1 on most mucosal keratinocytes, whereas herpesvirus entry mediator (HVEM) was found only on a subpopulation of cells, suggesting that nectin-1 acts as primary receptor for HSV-1 in human oral mucosa. To mimic the supposed entry route of HSV-1 via microlesions in vivo, we mechanically wounded the mucosa prior to infection. While we observed a limited number of infected keratinocytes in some wounded mucosa samples, other samples showed no infected cells. Thus, we conclude that mechanical wounding of mucosa is insufficient for the virus to efficiently overcome epithelial barriers and to make entry-mediating receptors accessible. IMPORTANCE To invade the target tissue of its human host during primary infection, herpes simplex virus (HSV) must overcome the epithelial barriers of mucosa, skin, or cornea. For most viruses, the mechanisms underlying the invasion into the target tissues of their host organism are still open. Here, we established an ex vivo infection

Mechanical Barriers Restrict Invasion of Herpes Simplex Virus 1 into Human Oral Mucosa.

PubMed

Thier, Katharina; Petermann, Philipp; Rahn, Elena; Rothamel, Daniel; Bloch, Wilhelm; Knebel-Mörsdorf, Dagmar

2017-11-15

Oral mucosa is one of the main target tissues of the human pathogen herpes simplex virus 1 (HSV-1). How the virus overcomes the protective epithelial barriers and penetrates the tissue to reach its receptors and initiate infection is still unclear. Here, we established an ex vivo infection assay with human oral mucosa that allows viral entry studies in a natural target tissue. The focus was on the susceptibility of keratinocytes in the epithelium and the characterization of cellular receptors that mediate viral entry. Upon ex vivo infection of gingiva or vestibular mucosa, we observed that intact human mucosa samples were protected from viral invasion. In contrast, the basal layer of the oral epithelium was efficiently invaded once the connective tissue and the basement membrane were removed. Later during infection, HSV-1 spread from basal keratinocytes to upper layers, demonstrating the susceptibility of the stratified squamous epithelium to HSV-1. The analysis of potential receptors revealed nectin-1 on most mucosal keratinocytes, whereas herpesvirus entry mediator (HVEM) was found only on a subpopulation of cells, suggesting that nectin-1 acts as primary receptor for HSV-1 in human oral mucosa. To mimic the supposed entry route of HSV-1 via microlesions in vivo , we mechanically wounded the mucosa prior to infection. While we observed a limited number of infected keratinocytes in some wounded mucosa samples, other samples showed no infected cells. Thus, we conclude that mechanical wounding of mucosa is insufficient for the virus to efficiently overcome epithelial barriers and to make entry-mediating receptors accessible. IMPORTANCE To invade the target tissue of its human host during primary infection, herpes simplex virus (HSV) must overcome the epithelial barriers of mucosa, skin, or cornea. For most viruses, the mechanisms underlying the invasion into the target tissues of their host organism are still open. Here, we established an ex vivo infection model of

Synthesis of zinc phthalocyanine with large steric hindrance and its photovoltaic performance for dye-sensitized solar cells.

PubMed

Lin, Li; Peng, Bosi; Shi, Wenye; Guo, Yingying; Li, Renjie

2015-03-28

A zinc phthalocyanine (ZnPc) derivative (Zn-tri-PcNc-8) containing tri-benzonaphtho-condensed porphyrazine with one carboxylic and six diphenylphenoxy peripheral substitutions was designed and synthesized as a sensitizer for dye-sensitized solar cells (DSSCs). For the purpose of extending the absorption spectra while minimizing the formation of ZnPc molecular aggregates, bulky 2,6-diphenylphenoxy groups were used as electron donor moieties, and the carboxylic group as an anchoring group to graft the sensitizer onto the semiconductor. It was found that a TiO2-based solar cell sensitized by Zn-tri-PcNc-8 shows a maximum incident photon-to-current conversion efficiency in the red/near-IR light range (650-750 nm), and a solar cell sensitized at near room temperature (30 °C) for 48 h exhibits the best efficiency (3.01%). The efficiency was much higher than that (1.96%) for a solar cell sensitized by its analogue (Zn-tri-PcNc-2) having one carboxyl and three tert-butyl groups without chenodeoxycholic acid (CDCA), indicating that the introduction of six bulky diphenylphenoxy substitutions with large steric hindrance in the ZnPc macrocycle can effectively suppress the molecular aggregates, thus resulting in an improved conversion efficiency. The present results shed light on an effective solution to adjust the ZnPc property via chemical modification such as changing the "push-pull" effect and adding large steric hindrance substituents to further improve the efficiency of the phthalocyanine-sensitized solar cell.

Density functional theory analysis of the impact of steric interaction on the function of switchable polarity solvents

DOE PAGES

McNally, Joshua S.; Noll, Bruce; Orme, Christopher J.; ...

2015-05-04

Here, a density functional theory (DFT) analysis has been performed to explore the impact of steric interactions on the function of switchable polarity solvents (SPS) and their implications on a quantitative structure-activity relationship (QSAR) model previously proposed for SPS. An x-ray crystal structure of the N,N-dimethylcyclohexylammonium bicarbonate (Hdmcha) salt has been solved as an asymmetric unit containing two cation/anion pairs, with a hydrogen bonding interaction observed between the bicarbonate anions, as well as between the cation and anion in each pair. DFT calculations provide an optimized structure of Hdmcha that closely resembles experimental data and reproduces the cation/anion interaction withmore » the inclusion of a dielectric field. Relaxed potential energy surface (PES) scans have been performed on Hdmcha-based computational model compounds, differing in the size of functional group bonded to the nitrogen center, to assess the steric impact of the group on the relative energy and structural properties of the compound. Results suggest that both the length and amount of branching associated with the substituent impact the energetic limitations on rotation of the group along the N-R bond and NC-R bond, and disrupt the energy minimized position of the hydrogen bonded bicarbonate group. The largest interaction resulted from functional groups that featured five bonds between the ammonium proton and a proton on a functional group with the freedom of rotation to form a pseudo-six membered ring which included both protons.« less

Planar varactor frequency multiplier devices with blocking barrier

NASA Technical Reports Server (NTRS)

Lieneweg, Udo (Inventor); Frerking, Margaret A. (Inventor); Maserjian, Joseph (Inventor)

1994-01-01

The invention relates to planar varactor frequency multiplier devices with a heterojunction blocking barrier for near millimeter wave radiation of moderate power from a fundamental input wave. The space charge limitation of the submillimeter frequency multiplier devices of the BIN(sup +) type is overcome by a diode structure comprising an n(sup +) doped layer of semiconductor material functioning as a low resistance back contact, a layer of semiconductor material with n-type doping functioning as a drift region grown on the back contact layer, a delta doping sheet forming a positive charge at the interface of the drift region layer with a barrier layer, and a surface metal contact. The layers thus formed on an n(sup +) doped layer may be divided into two isolated back-to-back BNN(sup +) diodes by separately depositing two surface metal contacts. By repeating the sequence of the drift region layer and the barrier layer with the delta doping sheet at the interfaces between the drift and barrier layers, a plurality of stacked diodes is formed. The novelty of the invention resides in providing n-type semiconductor material for the drift region in a GaAs/AlGaAs structure, and in stacking a plurality of such BNN(sup +) diodes stacked for greater output power with and connected back-to-back with the n(sup +) GaAs layer as an internal back contact and separate metal contact over an AlGaAs barrier layer on top of each stack.

The barrier to ice nucleation in monatomic water

NASA Astrophysics Data System (ADS)

Prestipino, Santi

2018-03-01

Crystallization from a supercooled liquid initially proceeds via the formation of a small solid embryo (nucleus), which requires surmounting an activation barrier. This phenomenon is most easily studied by numerical simulation, using specialized biased-sampling techniques to overcome the limitations imposed by the rarity of nucleation events. Here, I focus on the barrier to homogeneous ice nucleation in supercooled water, as represented by the monatomic-water model, which in the bulk exhibits a complex interplay between different ice structures. I consider various protocols to identify solidlike particles on a computer, which perform well enough for the Lennard-Jones model, and compare their respective impact on the shape and height of the nucleation barrier. It turns out that the effect is stronger on the nucleus size than on the barrier height. As a by-product of the analysis, I determine the structure of the nucleation cluster, finding that the relative amount of ice phases in the cluster heavily depends on the method used for classifying solidlike particles. Moreover, the phase which is most favored during the earlier stages of crystallization may happen, depending on the nucleation coordinate adopted, to be different from the stable polymorph. Therefore, the quality of a reaction coordinate cannot be assessed simply on the basis of the barrier height obtained. I explain how this outcome is possible and why it just points out the shortcoming of collective variables appropriate to simple fluids in providing a robust method of particle classification for monatomic water.

Direct access to highly crystalline mesoporous nano TiO2 using sterically bulky organic acid templates

NASA Astrophysics Data System (ADS)

Bakre, Pratibha V.; Tilve, S. G.

2018-05-01

Sterically bulky monocarboxylic acid templates pivalic acid and phenoxyacetic acid are reported for the first time as organic templates in the sol-gel synthesis of TiO2. Mesoporous nanoparticulates of pure anatase phase and of well defined size were synthesized. The characterization of the materials prepared was done by various methods such as XRD, SEM, TEM, FTIR, UV-DRS, BET, etc. The prepared TiO2 samples were evaluated for the day light photodegradation of methylene blue by comparing with Degussa P25 and templates free synthesized TiO2 and were found to be more efficient.

Impermeable flexible liquid barrier film for encapsulation of DSSC metal electrodes

PubMed Central

Yang, Junghee; Min, Misook; Yoon, Yeoheung; Kim, Won Jung; Kim, Sol; Lee, Hyoyoung

2016-01-01

Encapsulation of electronic devices such as dye-sensitized solar cells (DSSCs) is prone to degradation under normal atmospheric conditions, even with hermetic barriers on the metal electrodes. Overcoming this problem is crucial to increasing DSSC lifetimes and making them commercially viable. Herein, we report a new impermeable flexible liquid barrier film using polyvinyl alcohol (PVA) and partially reduced graphene oxide (PrGO), which dramatically enhances the lifetime of Ag metal electrodes (typically used in DSSCs) immersed in a highly acidic iodolyte solution. The Ag metal electrode encapsulated by the PVA/PrGO film survived for over 500 hrs, superior to existing barriers of glass frits, epoxy resins and polymers. The PVA/PrGO film strongly adheres to the Ag metal surface, and the resulting PVA/PrGO/Ag electrode is stable even on a curved substrate, with a sheet resistance nearly independent of curvature. These results give new insight for the design of high-performance and solution-processable flexible liquid barrier films for a wide range of applications, in particular for the encapsulation of electronic devices with liquid electrolytes. PMID:27263654

Overcoming psychosocial and developmental barriers to blood and marrow transplantation (BMT) in an adolescent/young adult (AYA) transgender patient with chronic myelogenous leukemia.

PubMed

Khazal, Sajad; Abdel-Azim, Hisham; Kapoor, Neena; Mahadeo, Kris M

2014-11-01

Adolescents/young adults (AYAs) afflicted with cancer face unique barriers to potentially standard curative therapies, such as blood and marrow transplantation (BMT). Transgender AYAs face additional barriers and there is a dearth of published literature regarding their oncology-related experience. We present the case of an AYA male-to-female (MTF) transgender patient on cross-sex hormone therapy, with a history of Chronic Myelogenous Leukemia (CML) and significant psychosocial barriers, which initially served as a barrier to BMT at two different centers; we modified our standard consent and education process and was able to successfully proceed with BMT and subsequently cure her CML. Despite unique challenges, AYA and transgender patients with significant psychosocial barriers may achieve successful outcomes with BMT. Research is needed regarding guidelines for cross-sex hormone therapy administration for patients undergoing BMT and other issues, which may be unique to the transgender experience.

Overcoming breastfeeding problems

MedlinePlus

Plugged milk ducts; Nipple soreness when breastfeeding; Breastfeeding - overcoming problems; Let-down reflex ... Breastfeeding (nursing) your baby can be a good experience for both the mother and the baby. It ...

Resonant interaction of electromagnetic wave with plasma layer and overcoming the radiocommunication blackout problem

NASA Astrophysics Data System (ADS)

Bogatskaya, A. V.; Klenov, N. V.; Tereshonok, M. V.; Adjemov, S. S.; Popov, A. M.

2018-05-01

We present an analysis of the possibility of penetrating electromagnetic waves through opaque media using an optical-mechanical analogy. As an example, we consider the plasma sheath surrounding the vehicle as a potential barrier and analyze the overcoming of radiocommunication blackout problem. The idea is to embed a «resonator» between the surface on the vehicle and plasma sheath which is supposed to provide an effective tunneling of the signal to the receiving antenna. We discuss the peculiarities of optical mechanical analogy applicability and analyze the radio frequency wave tunneling regime in detail. The cases of normal and oblique incidence of radiofrequency waves on the vehicle surface are studied.

OVERCOMING BARRIERS To DIVERSITY IN CHIROPRACTIC PATIENT AND PRACTITIONER POPULATIONS: A COMMENTARY.

PubMed

Young, Kenneth J

2015-01-01

Increasing the diversity of practitioner and patient populations has been identified as a worthy goal in the chiropractic profession, which has predominantly white male practitioners and white female patients in the USA. Toward that end, 'diversity' has been the topic of several papers and was the theme of a 2012 conference of chiropractic educators. However, generally just the microcosm of the interactions of practitioners with patients or teachers with students has been discussed. The macrocosm of larger societal issues and government policies has not been broached. Examples of issues and policies that affect diversity within a profession include portrayals of, and value judgements on diversity by the media and politicians, as well as public funding for healthcare and education. Diversity was defined in this paper to mean differences in race, sex, sexual orientation, economic status, ethnicity, religion and other life circumstances in a population. The purpose of this paper is to raise awareness of evidence that social issues and government policy affect the diversity of practitioners and patients, and to suggest that the barriers to diversity present in these realms be addressed with a cogent, profession-wide effort in order to help increase the diversity of people involved with chiropractic.

Possible steric control of the relative strength of chelation enhanced fluorescence for zinc(II) compared to cadmium(II): metal ion complexing properties of tris(2-quinolylmethyl)amine, a crystallographic, UV-visible, and fluorometric study.

PubMed

Williams, Neil J; Gan, Wei; Reibenspies, Joseph H; Hancock, Robert D

2009-02-16

The idea is examined that steric crowding in ligands can lead to diminution of the chelation enhanced fluorescence (CHEF) effect in complexes of the small Zn(II) ion as compared to the larger Cd(II) ion. Steric crowding is less severe for the larger ion and for the smaller Zn(II) ion leads to Zn-N bond length distortion, which allows some quenching of fluorescence by the photoinduced electron transfer (PET) mechanism. Some metal ion complexing properties of the ligand tris(2-quinolylmethyl)amine (TQA) are presented in support of the idea that more sterically efficient ligands, which lead to less M-N bond length distortion with the small Zn(II) ion, will lead to a greater CHEF effect with Zn(II) than Cd(II). The structures of [Zn(TQA)H(2)O](ClO(4))(2).1.5 H(2)O (1), ([Pb(TQA)(NO(3))(2)].C(2)H(5)OH) (2), ([Ag(TQA)(ClO(4))]) (3), and (TQA).C(2)H(5)OH (4) are reported. In 1, the Zn(II) is 5-coordinate, with four N-donors from the ligand and a water molecule making up the coordination sphere. The Zn-N bonds are all of normal length, showing that the level of steric crowding in 1 is not sufficient to cause significant Zn-N bond length distortion. This leads to the observation that, as expected, the CHEF effect in the Zn(II)/TQA complex is much stronger than that in the Cd(II)/TQA complex, in contrast to similar but more sterically crowded ligands, where the CHEF effect is stronger in the Cd(II) complex. The CHEF effect for TQA with the metal ions examined varies as Zn(II) > Cd(II) > Ni(II) > Pb(II) > Hg(II) > Cu(II). The structure of 2 shows an 8-coordinate Pb(II), with evidence of a stereochemically active lone pair, and normal Pb-N bond lengths. In 3, the Ag(I) is 5-coordinate, with four N-donors from the TQA and an oxygen from the perchlorate. The Ag(I) shows no distortion toward linear 2-coordinate geometry, and the Ag-N bonds fall slightly into the upper range for Ag-N bonds in 5-coordinate complexes. The structure of 4 shows the TQA ligand to be involved in pi

Inhibition of Apoptosis Overcomes Stage-Related Compatibility Barriers to Chimera Formation in Mouse Embryos.

PubMed

Masaki, Hideki; Kato-Itoh, Megumi; Takahashi, Yusuke; Umino, Ayumi; Sato, Hideyuki; Ito, Keiichi; Yanagida, Ayaka; Nishimura, Toshinobu; Yamaguchi, Tomoyuki; Hirabayashi, Masumi; Era, Takumi; Loh, Kyle M; Wu, Sean M; Weissman, Irving L; Nakauchi, Hiromitsu

2016-11-03

Cell types more advanced in development than embryonic stem cells, such as EpiSCs, fail to contribute to chimeras when injected into pre-implantation-stage blastocysts, apparently because the injected cells undergo apoptosis. Here we show that transient promotion of cell survival through expression of the anti-apoptotic gene BCL2 enables EpiSCs and Sox17 + endoderm progenitors to integrate into blastocysts and contribute to chimeric embryos. Upon injection into blastocyst, BCL2-expressing EpiSCs contributed to all bodily tissues in chimeric animals while Sox17 + endoderm progenitors specifically contributed in a region-specific fashion to endodermal tissues. In addition, BCL2 expression enabled rat EpiSCs to contribute to mouse embryonic chimeras, thereby forming interspecies chimeras that could survive to adulthood. Our system therefore provides a method to overcome cellular compatibility issues that typically restrict chimera formation. Application of this type of approach could broaden the use of embryonic chimeras, including region-specific chimeras, for basic developmental biology research and regenerative medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

Steric engineering of metal-halide perovskites with tunable optical band gaps

NASA Astrophysics Data System (ADS)

Filip, Marina R.; Eperon, Giles E.; Snaith, Henry J.; Giustino, Feliciano

2014-12-01

Owing to their high energy-conversion efficiency and inexpensive fabrication routes, solar cells based on metal-organic halide perovskites have rapidly gained prominence as a disruptive technology. An attractive feature of perovskite absorbers is the possibility of tailoring their properties by changing the elemental composition through the chemical precursors. In this context, rational in silico design represents a powerful tool for mapping the vast materials landscape and accelerating discovery. Here we show that the optical band gap of metal-halide perovskites, a key design parameter for solar cells, strongly correlates with a simple structural feature, the largest metal-halide-metal bond angle. Using this descriptor we suggest continuous tunability of the optical gap from the mid-infrared to the visible. Precise band gap engineering is achieved by controlling the bond angles through the steric size of the molecular cation. On the basis of these design principles we predict novel low-gap perovskites for optimum photovoltaic efficiency, and we demonstrate the concept of band gap modulation by synthesising and characterising novel mixed-cation perovskites.

The dragons of inaction: psychological barriers that limit climate change mitigation and adaptation.

PubMed

Gifford, Robert

2011-01-01

Most people think climate change and sustainability are important problems, but too few global citizens engaged in high-greenhouse-gas-emitting behavior are engaged in enough mitigating behavior to stem the increasing flow of greenhouse gases and other environmental problems. Why is that? Structural barriers such as a climate-averse infrastructure are part of the answer, but psychological barriers also impede behavioral choices that would facilitate mitigation, adaptation, and environmental sustainability. Although many individuals are engaged in some ameliorative action, most could do more, but they are hindered by seven categories of psychological barriers, or "dragons of inaction": limited cognition about the problem, ideological world views that tend to preclude pro-environmental attitudes and behavior, comparisons with key other people, sunk costs and behavioral momentum, discredence toward experts and authorities, perceived risks of change, and positive but inadequate behavior change. Structural barriers must be removed wherever possible, but this is unlikely to be sufficient. Psychologists must work with other scientists, technical experts, and policymakers to help citizens overcome these psychological barriers.

Transient thermography testing of unpainted thermal barrier coating surfaces

NASA Astrophysics Data System (ADS)

Ptaszek, Grzegorz; Cawley, Peter; Almond, Darryl; Pickering, Simon

2013-01-01

This paper has investigated the effects of uneven surface discolouration of a thermal barrier coating (TBC) and of its IR translucency on the thermal responses observed by using mid and long wavelength IR cameras. It has been shown that unpainted blades can be tested satisfactorily by using a more powerful flash heating system and a long wavelength IR camera. The problem of uneven surface emissivity can be overcome by applying 2nd derivative processing of the log-log surface cooling curves.

Barriers to comparing the usability of electronic health records.

PubMed

Ratwani, Raj M; Hettinger, A Zachary; Fairbanks, Rollin J

2017-04-01

Despite the widespread adoption of electronic health records (EHRs), usability of many EHRs continues to be suboptimal, with some vendors failing to meet usability standards, resulting in clinician frustration and patient safety hazards. In an effort to increase EHR vendor competition on usability, recommendations have been made and legislation drafted to develop comparison tools that would allow purchasers to better understand the usability of EHR products prior to purchase. Usability comparison can be based on EHR vendor design and development processes, vendor usability testing as part of the Office of the National Coordinator for Health Information Technology certification program, and usability of implemented products. Barriers exist within the current certified health technology program that prevent effective comparison of usability during each of these stages. We describe the importance of providing purchasers with improved information about EHR usability, barriers to making usability comparisons, and solutions to overcome these barriers. © The Author 2016. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Barriers to Breast and Cervical Cancer Screening in Singapore: a Mixed Methods Analysis.

PubMed

Malhotra, Chetna; Bilger, Marcel; Liu, Joy; Finkelstein, Eric

2016-01-01

In order to increase breast and cervical cancer screening uptake in Singapore, women's perceived barriers to screening need to be identified and overcome. Using data from both focus groups and surveys, we aimed to assess perceived barriers and motivations for breast and cervical cancer screening. We conducted 8 focus groups with 64 women, using thematic analysis to identify overarching themes related to women's attitudes towards screening. Based on recurring themes from focus groups, several hypotheses regarding potential barriers and motivations to screen were generated and tested through a national survey of 801 women aged 25-64. Focus group participants had misconceptions related to screening, believing that the procedures were painful. Cost was an issue, as well as efficacy and fatalism. By identifying barriers to and motivators for screening through a mixed-method design that has both nuance and external validity, this study offers valuable suggestions to policymakers to improve breast and cervical cancer screening uptake in Singapore.

Barriers to involvement of men in ANC and VCT in Khayelitsha, South Africa.

PubMed

Mohlala, Boshishi K F; Gregson, Simon; Boily, Marie-Claude

2012-01-01

We used qualitative methods to assess pregnant women and men's attitudes, feelings, beliefs, experiences and reactions to male partners' involvement in antenatal clinic (ANC) in Khayelitsha, Cape Town, South Africa. The aims of these studies were to determine barriers to male partners' attendance of ANC with their pregnant female partners and to identify possible strategies to overcome these barriers. Findings from the qualitative studies demonstrated that pregnant women were keen to invite their male sexual partners and that men would attend if invited. The main barrier to male participation was lack of awareness and the healthcare facility environment. The findings of these studies emphasized the need to increase awareness among men in Khayelitsha of the need for male attendance of ANC and the need to address the barriers to male attendance of ANC. It was clear that community sensitization programmes coupled with improvement of the health facility environment to be receptive to men are essential for increasing male attendance of ANC.

Barriers to and facilitators of HIV-positive patients' adherence to antiretroviral treatment regimens.

PubMed

Roberts, K J

2000-03-01

HIV-positive patients must strictly adhere to antiretroviral regimens for the medications to work properly. Little, however, is known about the obstacles that patients face in adhering to the regimens or what, if anything, helps patients to adhere. The goals of the project were to describe, from HIV-positive patients' own perspectives, the barriers they face in adhering to antiretroviral regimens and the strategies they use to maximize their adherence. Five main barriers (forgetfulness, social/physical environment, complexity of the regimens, medication side effects, and inadequate patient knowledge) to adherence and six main facilitators (mechanical devices, "making a commitment," "routinizing," health beliefs, social support, and professional support) emerged from the data. Patients may overcome some of these barriers by receiving better health education about the need for adherence, professional and lay support for their efforts, and mechanical devices such as alarm clocks and medi-sets. Other barriers, however, such as the complexity of the medications, highlight the need for simplified antiretroviral regimens.

Understanding barriers to implementation of an adaptive land management program

USGS Publications Warehouse

Jacobson, S.K.; Morris, J.K.; Sanders, J.S.; Wiley, E.N.; Brooks, M.; Bennetts, R.E.; Percival, H.F.; Marynowski, S.

2006-01-01

The Florida Fish and Wildlife Conservation Commission manages over 650,000 ha, including 26 wildlife management and environmental areas. To improve management, they developed an objective-based vegetation management (OBVM) process that focuses on desired conditions of plant communities through an adaptive management framework. Our goals were to understand potential barriers to implementing OBVM and to recommend strategies to overcome barriers. A literature review identified 47 potential barriers in six categories to implementation of adaptive and ecosystem management: logistical, communication, attitudinal, institutional, conceptual, and educational. We explored these barriers through a bureau-wide survey of 90 staff involved in OBVM and personal interviews with area managers, scientists, and administrators. The survey incorporated an organizational culture assessment instrument to gauge how institutional factors might influence OBVM implementation. The survey response rate was 69%. Logistics and communications were the greatest barriers to implementing OBVM. Respondents perceived that the agency had inadequate resources for implementing OBVM and provided inadequate information. About one-third of the respondents believed OBVM would decrease their job flexibility and perceived greater institutional barriers to the approach. The 43% of respondents who believed they would have more responsibility under OBVM also had greater attitudinal barriers. A similar percentage of respondents reported OBVM would not give enough priority to wildlife. Staff believed that current agency culture was hierarchical but preferred a culture that would provide more flexibility for adaptive management and would foster learning from land management activities. In light of the barriers to OBVM, we recommend the following: (1) mitigation of logistical barriers by addressing real and perceived constraints of staff, funds, and other resources in a participatory manner; (2) mitigation of

Understanding barriers to implementation of an adaptive land management program.

PubMed

Jacobson, Susan K; Morris, Julie K; Sanders, J Scott; Wiley, Eugene N; Brooks, Michael; Bennetts, Robert E; Percival, H Franklin; Marynowski, Susan

2006-10-01

The Florida Fish and Wildlife Conservation Commission manages over 650,000 ha, including 26 wildlife management and environmental areas. To improve management, they developed an objective-based vegetation management (OBVM) process that focuses on desired conditions of plant communities through an adaptive management framework. Our goals were to understand potential barriers to implementing OBVM and to recommend strategies to overcome barriers. A literature review identified 47 potential barriers in six categories to implementation of adaptive and ecosystem management: logistical, communication, attitudinal, institutional, conceptual, and educational. We explored these barriers through a bureau-wide survey of 90 staff involved in OBVM and personal interviews with area managers, scientists, and administrators. The survey incorporated an organizational culture assessment instrument to gauge how institutional factors might influence OBVM implementation. The survey response rate was 69%. Logistics and communications were the greatest barriers to implementing OBVM. Respondents perceived that the agency had inadequate resources for implementing OBVM and provided inadequate information. About one-third of the respondents believed OBVM would decrease their job flexibility and perceived greater institutional barriers to the approach. The 43% of respondents who believed they would have more responsibility under OBVM also had greater attitudinal barriers. A similar percentage of respondents reported OBVM would not give enough priority to wildlife. Staff believed that current agency culture was hierarchical but preferred a culture that would provide more flexibility for adaptive management and would foster learning from land management activities. In light of the barriers to OBVM, we recommend the following: (1) mitigation of logistical barriers by addressing real and perceived constraints of staff, funds, and other resources in a participatory manner; (2) mitigation of

Ocular Drug Delivery Barriers-Role of Nanocarriers in the Treatment of Anterior Segment Ocular Diseases.

PubMed

Bachu, Rinda Devi; Chowdhury, Pallabitha; Al-Saedi, Zahraa H F; Karla, Pradeep K; Boddu, Sai H S

2018-02-27

Ocular drug delivery is challenging due to the presence of anatomical and physiological barriers. These barriers can affect drug entry into the eye following multiple routes of administration (e.g., topical, systemic, and injectable). Topical administration in the form of eye drops is preferred for treating anterior segment diseases, as it is convenient and provides local delivery of drugs. Major concerns with topical delivery include poor drug absorption and low bioavailability. To improve the bioavailability of topically administered drugs, novel drug delivery systems are being investigated. Nanocarrier delivery systems demonstrate enhanced drug permeation and prolonged drug release. This review provides an overview of ocular barriers to anterior segment delivery, along with ways to overcome these barriers using nanocarrier systems. The disposition of nanocarriers following topical administration, their safety, toxicity and clinical trials involving nanocarrier systems are also discussed.

Perceptions of barriers to paternal presence and contribution during childbirth: an exploratory study from Syria.

PubMed

Abushaikha, Lubna; Massah, Rana

2013-03-01

The barriers that face fathers during childbirth are an understudied phenomenon. The objective of our study was to explore Syrian parents' perceptions of barriers to paternal presence and contribution during childbirth. A descriptive phenomenological qualitative approach based on Colaizzi's method was used with a purposive sample of 23 mothers and 14 fathers recruited from a major public maternity hospital in Syria. In our study, four themes on barriers to paternal presence and contribution during childbirth were found: 1) sociocultural influences and rigidity; 2) being unprepared; 3) unsupportive policies and attitudes; and 4) unfavorable reactions and circumstances. Common and current sociocultural norms in Syria do not encourage fathers to be present or contribute during childbirth. Therefore, establishing culturally sensitive supportive policies and practices is a vital step toward overcoming these barriers. © 2013, Copyright the Authors Journal compilation © 2013, Wiley Periodicals, Inc.

Overcoming job stress

MedlinePlus

... medlineplus.gov/ency/patientinstructions/000884.htm Overcoming job stress To use the sharing features on this page, ... stay healthy and feel better. Causes of Job Stress Although the cause of job stress is different ...

Barriers to Diagnosis and Treatment of Depression: Voices from a Rural African-American Faith Community

PubMed Central

Bryant, Keneshia; Greer-Williams, Nancy; Willis, Nathaniel; Hartwig, Mary

2014-01-01

Mental health disparities exist for rural African-Americans regarding the early detection of depression and its effective treatment. Disparities that are evident in rural communities include limited mental health resources and the stigma of depression. The faith community has a long-standing history of being the initial source of help to those who experience depression. The purpose of this qualitative study was to examine how rural African-American faith communities view the barriers to diagnosis and treatment of depression. A convenience sample of 24 persons (N = 24) participated in focus groups and interviews. Four internal barriers were identified: personal business, “mind-set,” “denial,” and “put on a front.” Additionally, four external barriers were identified: “spiritual beliefs,” “lack of medical resources,” “lack of education about depression,” and “stigma.” The identified barriers supported the results from previous studies, but they also highlighted other less acknowledged barriers. In conclusion, interventions are needed to overcome these barriers in order to eliminate the depression disparities experienced by this population. PMID:24218871

Barriers and paths to market for genetically engineered crops.

PubMed

Rommens, Caius M

2010-02-01

Each year, billions of dollars are invested in efforts to improve crops through genetic engineering (GE). These activities have resulted in a surge of publications and patents on technologies and genes: a momentum in basic research that, unfortunately, is not sustained throughout the subsequent phases of product development. After more than two decades of intensive research, the market for transgenic crops is still dominated by applications of just a handful of methods and genes. This discrepancy between research and development reflects difficulties in understanding and overcoming seven main barriers-to-entry: (1) trait efficacy in the field, (2) critical product concepts, (3) freedom-to-operate, (4) industry support, (5) identity preservation and stewardship, (6) regulatory approval and (7) retail and consumer acceptance. In this review, I describe the various roadblocks to market for transgenic crops and also discuss methods and approaches on how to overcome these, especially in the United States.

Family Physicians’ Barriers to Cancer Screening in Extremely Obese Patients

PubMed Central

Ferrante, Jeanne M.; Fyffe, Denise C.; Vega, Marielos L.; Piasecki, Alicja K.; Ohman-Strickland, Pamela A.; Crabtree, Benjamin F.

2010-01-01

Extremely obese women are less likely than nonobese women to receive breast and cervical cancer screening examinations. Reasons for this disparity are unclear and may stem from patient and/or physician barriers. This sequential mixed-methods study used individual in-depth interviews of 15 family physicians followed by a mail survey of 255 family physicians (53% response rate) to understand the barriers they faced in performing cancer screening examinations in extremely obese women. Barriers fell into three main areas: (i) difficulty doing pelvic and breast exams; (ii) inadequate equipment; and (iii) challenges overcoming patient barriers and refusal. This led some physicians to avoid performing breast and pelvic examinations on extremely obese women. Having more knowledge about specific examination techniques was associated with less difficulty in palpating lumps on breast and pelvic examinations (P < 0.005). Physicians perceived that embarrassment, aversion to undressing, and avoidance of discussions related to their weight were the most frequent barriers extremely obese women had with getting physical examinations. Educating and/or motivating patients and addressing fears were strategies used most frequently when patients refused mammograms or Pap smears. Interventions focusing on physician barriers, such as educating them on specific examination techniques, obtaining adequate equipment and supplies, and providing resources to assist physicians in dealing with patient barriers and refusal, may be fruitful in increasing cancer screening rates in extremely obese patients. Future research studies testing the effectiveness of these strategies are needed to improve cancer outcomes in this high-risk population. PMID:20019676

Intranasal gene delivery for treating Parkinson's disease: overcoming the blood-brain barrier.

PubMed

Aly, Amirah E-E; Waszczak, Barbara L

2015-01-01

Developing a disease-modifying gene therapy for Parkinson's disease (PD) has been a high priority for over a decade. However, due to the inability of large biomolecules to cross the blood-brain barrier (BBB), the only means of delivery to the brain has been intracerebral infusion. Intranasal administration offers a non-surgical means of bypassing the BBB to deliver neurotrophic factors, and the genes encoding them, directly to the brain. This review summarizes: i) evidence demonstrating intranasal delivery to the brain of a number of biomolecules having therapeutic potential for various CNS disorders; and ii) evidence demonstrating neuroprotective efficacy of a subset of biomolecules specifically for PD. The intersection of these two spheres represents the area of opportunity for development of new intranasal gene therapies for PD. To that end, our laboratory showed that intranasal administration of glial cell line-derived neurotrophic factor (GDNF), or plasmid DNA nanoparticles encoding GDNF, provides neuroprotection in a rat model of PD, and that the cells transfected by the nanoparticle vector are likely to be pericytes. A number of genes encoding neurotrophic factors have therapeutic potential for PD, but few have been tested by the intranasal route and shown to be neuroprotective in a model of PD. Intranasal delivery provides a largely unexplored, promising approach for development of a non-invasive gene therapy for PD.

Breaking down information barriers: a guide to international research of medical resources on the World Wide Web.

PubMed

Risin, J A

1998-01-01

The purpose of this paper is to facilitate international research of medical resources on the World Wide Web. International research consists of overcoming a unique set of obstacles and challenges that are not involved when undertaking research tasks using only U.S.-based information. Utilizing the World Wide Web can help us to overcome most of the restraints we would have to face when we perform research outside of our local geography. Currently, there are a number of Internet Web sites that may assist us in breaking down the barriers to undertaking international research.

Laser flash photolysis and CIDNP studies of steric effects on coupling rate constants of imidazolidine nitroxide with carbon-centered radicals, methyl isobutyrate-2-yl and tert-butyl propionate-2-yl.

PubMed

Zubenko, Dmitry; Tsentalovich, Yuri; Lebedeva, Nataly; Kirilyuk, Igor; Roshchupkina, Galina; Zhurko, Irina; Reznikov, Vladimir; Marque, Sylvain R A; Bagryanskaya, Elena

2006-08-04

Time-resolved chemically induced dynamic nuclear polarization (TR-CIDNP) and laser flash photolysis (LFP) techniques have been used to measure rate constants for coupling between acrylate-type radicals and a series of newly synthesized stable imidazolidine N-oxyl radicals. The carbon-centered radicals under investigation were generated by photolysis of their corresponding ketone precursors RC(O)R (R = C(CH3)2-C(O)OCH3 and CH(CH3)-C(O)-OtBu) in the presence of stable nitroxides. The coupling rate constants kc for modeling studies of nitroxide-mediated polymerization (NMP) experiments were determined, and the influence of steric and electronic factors on kc values was addressed by using a Hammett linear free energy relationship. The systematic changes in kc due to the varied steric (Es,n) and electronic (sigmaL,n) characters of the substituents are well-described by the biparameter equation log(kc/M- 1s(-1)) = 3.52sigmaL,n + 0.47Es,n + 10.62. Hence, kc decreases with the increasing steric demand and increases with the increasing electron-withdrawing character of the substituents on the nitroxide.

Uptake Mechanism of ApoE-Modified Nanoparticles on Brain Capillary Endothelial Cells as a Blood-Brain Barrier Model

PubMed Central

Wagner, Sylvia; Zensi, Anja; Wien, Sascha L.; Tschickardt, Sabrina E.; Maier, Wladislaw; Vogel, Tikva; Worek, Franz; Pietrzik, Claus U.; Kreuter, Jörg; von Briesen, Hagen

2012-01-01

Background The blood-brain barrier (BBB) represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE) appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. Methodology/Principal Findings In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. Conclusions/Significance This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier. PMID:22396775

Uptake mechanism of ApoE-modified nanoparticles on brain capillary endothelial cells as a blood-brain barrier model.

PubMed

Wagner, Sylvia; Zensi, Anja; Wien, Sascha L; Tschickardt, Sabrina E; Maier, Wladislaw; Vogel, Tikva; Worek, Franz; Pietrzik, Claus U; Kreuter, Jörg; von Briesen, Hagen

2012-01-01

The blood-brain barrier (BBB) represents an insurmountable obstacle for most drugs thus obstructing an effective treatment of many brain diseases. One solution for overcoming this barrier is a transport by binding of these drugs to surface-modified nanoparticles. Especially apolipoprotein E (ApoE) appears to play a major role in the nanoparticle-mediated drug transport across the BBB. However, at present the underlying mechanism is incompletely understood. In this study, the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells was investigated to differentiate between active and passive uptake mechanism by flow cytometry and confocal laser scanning microscopy. Furthermore, different in vitro co-incubation experiments were performed with competing ligands of the respective receptor. This study confirms an active endocytotic uptake mechanism and shows the involvement of low density lipoprotein receptor family members, notably the low density lipoprotein receptor related protein, on the uptake of the ApoE-modified nanoparticles into the brain capillary endothelial cells. This knowledge of the uptake mechanism of ApoE-modified nanoparticles enables future developments to rationally create very specific and effective carriers to overcome the blood-brain barrier.

Multi-barrier field-emission behavior in PBTTT thin films at low temperatures

PubMed Central

Kang, Evan S. H.; Kim, Eunseong

2015-01-01

We investigated the low-temperature transport mechanism for poly[2,5-bis(3-alkylthiophen-2-yl)thieno(3,2-b)thiophene] (PBTTT). The temperature-dependent transport behavior was studied by varying the drain–source electric field and gate bias. The results suggest that low-temperature charge transport is dominated by direct tunneling at low electric fields, while field emission is prevailing for high electric fields with high carrier densities. However, the obtained barrier heights are remarkably greater than expected in a conventional field emission. We propose a simplified model of field emission through quasi-one-dimensional path with multiple barriers which shows good agreement with the results more clearly. Field emission across the domain boundaries may assist in overcoming the transport barriers induced by the interchain disorder, which results in the weak temperature dependence of conductivities and nonlinear current–voltage relation at low temperatures. PMID:25670532

Spiritual beliefs and barriers among managed care practitioners.

PubMed

McCauley, Jeanne; Jenckes, Mollie W; Tarpley, Margaret J; Koenig, Harold G; Yanek, Lisa R; Becker, Diane M

2005-01-01

Ninety percent of American adults believe in God and 82% pray weekly. A majority wants their physicians to address spirituality during their health care visit. However, clinicians incorporate spiritual discussion in less than 20% of visits. Our objectives were to measure clinician beliefs and identify perceived barriers to integrating spirituality into patient care in a statewide, primary care, managed care group. Practitioners completed a 30-item survey including demographics and religious involvement (DUREL), spirituality in patient care (SPC), and barriers (BAR). We analyzed data using frequencies, means, standard deviations, and ANOVA. Clinicians had a range of religious denominations (67% Christian, 14% Jewish, 11% Muslim, Hindu or Buddhist, 8% agnostic), were 57% female and 24% had training in spirituality. Sixty-six percent reported experiencing the divine. Ninety-five percent felt that a patient's spiritual outlook was important to handling health difficulties and 68% percent agreed that addressing spirituality was part of the physician's role. Ninety-five percent of our managed care group noted 'lack of time' as an important barrier, 'lack of training' was indicated by 69%, and 21% cited 'fear of response from administration'. Managed care practitioners in a time constrained setting were spiritual themselves and believed this to be important to patients. Respondents indicated barriers of time and training to implementing these beliefs. Comparing responses from our group to those in other published surveys on clinician spirituality, we find similar concerns. Clinician education may overcome these barriers and improve ability to more fully meet their patients' expressed needs regarding spirituality and beliefs.

Barriers to quality health care for the transgender population.

PubMed

Roberts, Tiffany K; Fantz, Corinne R

2014-07-01

The transgender community is arguably the most marginalized and underserved population in medicine. A special issue focusing on men's health would be incomplete without mention of this vulnerable population, which includes those transitioning to and from the male gender. Transgender patients face many barriers in their access to healthcare including historical stigmatization, both structural and financial barriers, and even a lack of healthcare provider experience in treating this unique population. Historical stigmatization fosters a reluctance to disclose gender identity, which can have dire consequences for long-term outcomes due to a lack of appropriate medical history including transition-related care. Even if a patient is willing to disclose their gender identity and transition history, structural barriers in current healthcare settings lack the mechanisms necessary to collect and track this information. Moreover, healthcare providers acknowledge that information is lacking regarding the unique needs and long-term outcomes for transgender patients, which contributes to the inability to provide appropriate care. All of these barriers must be recognized and addressed in order to elevate the quality of healthcare delivered to the transgender community to a level commensurate with the general population. Overcoming these barriers will require redefinition of our current system such that the care a patient receives is not exclusively linked to their sex but also considers gender identity. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Understanding the Steric Height Long Term Variability at the Bermuda Atlantic Time-Series Study (BATS) Site with a Neutral Density Approach

NASA Astrophysics Data System (ADS)

Goncalves Neto, A.; Johnson, R. J.; Bates, N. R.

2016-02-01

Rising sea level is one of the main concerns for human life in a scenario with global atmosphere and ocean warming, which is of particular concern for oceanic islands. Bermuda, located in the center of the Sargasso Sea, provides an ideal location to investigate sea level rise since it has a long term tide gauge (1933-present) and is in close proximity to deep ocean time-series sites, namely, Hydrostation `S' (1954-present) and the Bermuda Atlantic Time-Series Study site (1988-present). In this study, we use the monthly CTD deep casts at BATS to compute the contribution of steric height (SH) to the local sea surface height (SSH) for the past 24 years. To determine the relative contribution from the various water masses we first define 8 layers (Surface Layer, Upper Thermocline, Subtropical Mode-Water, Lower Thermocline, Antarctic Intermediate Water, Labrador Sea Water, Iceland-Scotland Overflow Water, Denmark Strait Overflow Water) based on neutral density criteria for which SH is computed. Additionally, we calculate the thermosteric and halosteric components for each of the defined neutral density layers. Surprisingly, the results show that, despite a 3.3mm/yr sea level rise observed at the Bermuda tide gauge, the steric contribution to the SSH at BATS has decreased at a rate of -1.1mm/yr during the same period. The thermal component is found to account for the negative trend in the steric height (-4.4mm/yr), whereas the halosteric component (3.3mm/yr) partially compensates the thermal signal and can be explained by an overall cooling and freshening at the BATS site. Although the surface layer and the upper thermocline waters are warming, all the subtropical and polar water masses, which represent most of the local water column, are cooling and therefore drive the overall SH contribution to the local SSH. Hence, it suggests that the mass contribution to the local SSH plays an important role in the sea level rise, for which we investigate with GRACE data.

Home Blood Pressure Telemonitoring: Rationale for Use, Required Elements, and Barriers to Implementation in Canada.

PubMed

Wood, Peter W; Boulanger, Pierre; Padwal, Raj S

2017-05-01

Contemporary hypertension guidelines strongly endorse the use of home blood pressure (BP) monitoring for hypertension diagnosis and management. However, barriers exist that prevent optimal use of home BP measurements. Patients might not follow the recommended home BP measurement protocol, might not take the required number of readings, and/or might report only selected readings to their providers. Providers might not calculate the mean (used for clinical decision-making) and/or incorporate home BP measurements into the medical record. Use of home BP telemonitoring, defined as the process by which home BP readings are securely teletransmitted and summarized within a health care portal or electronic medical record for provider use, might overcome these barriers. Telemonitoring, especially when combined with protocolized case management, leads to statistically significant and clinically important BP reductions, and improvements in overall BP control. Despite evidence supporting its use, home BP telemonitoring is not widely used in Canada. Barriers to adoption can be classified as structural and financial. Although technological advancements have made telemonitoring highly feasible, infrastructure is lacking, and implementation remains a challenge; this is especially true with respect to creating simple and cost-effective systems that are user-friendly and acceptable to patients as well as to providers. Ensuring data security is crucial to successful implementation, as is developing appropriate reimbursement models for providers. If these barriers can be overcome, home BP telemonitoring has the potential to make care provision easier and more convenient for patients and providers, while improving BP control in Canadians with hypertension. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Institutional barriers and strategies to health promotion: perspectives and experiences of Cape Verdean women health promoters.

PubMed

De Jesus, Maria

2010-06-01

Health promoters are critical resources in improving health care access and in providing culturally-responsive health education and interventions to members of medically underserved communities. Little is known about the barriers that impede their health-promoting practices and the strategies used to overcome these barriers. In-depth, semi-structured interviews were conducted with nine Cape Verdean women health promoters to examine their perspectives on barriers and strategies to health promotion. Findings revealed how their health promotion practice is influenced by a host of institutional barriers, including insufficient program funding, restrictive institutional policies, and a lack of culturally and linguistically appropriate health resources. Adaptive and resistant strategies used to counterbalance these barriers included forming supportive internal and external alliances, having a good mentor, and "making noise." A complete and effective model of health promotion must embrace not only individual-level factors, but also macro-level factors, thus emphasizing the need for institutional change to enhance health-promoting practices.

Institutional Barriers and Strategies to Health Promotion: Perspectives and Experiences of Cape Verdean Women Health Promoters

PubMed Central

2015-01-01

Background Health promoters are critical resources in improving health care access and in providing culturally-responsive health education and interventions to members of medically underserved communities. Little is known about the barriers that impede their health-promoting practices and the strategies used to overcome these barriers. Methods In-depth, semi-structured interviews were conducted with nine Cape Verdean women health promoters to examine their perspectives on barriers and strategies to health promotion. Results Findings revealed how their health promotion practice is influenced by a host of institutional barriers, including insufficient program funding, restrictive institutional policies, and a lack of culturally and linguistically appropriate health resources. Adaptive and resistant strategies used to counterbalance these barriers included forming supportive internal and external alliances, having a good mentor, and “making noise.” Discussion A complete and effective model of health promotion must embrace not only individual-level factors, but also macro-level factors, thus emphasizing the need for institutional change to enhance health-promoting practices. PMID:18307042

Benefits of and Barriers to Pharmacogenomics-Guided Treatment for Major Depressive Disorder.

PubMed

Ahmed, Ahmed T; Weinshilboum, Richard; Frye, Mark A

2018-05-01

Antidepressants have reduced the symptom burden for many Major Depressive Disorder (MDD) patients, but drug-related side effects and treatment resistance continue to present major challenges. Pharmacogenomics represents one approach to enhance antidepressant efficacy and avoid adverse reactions, but concerns remain with regard to the overall "value equation," and several barriers must be overcome to achieve the full potential of MDD pharmacogenomics. © 2018 American Society for Clinical Pharmacology and Therapeutics.

Barriers to Access to Palliative Care

PubMed Central

Hawley, Pippa

2017-01-01

Despite significant advances in understanding the benefits of early integration of palliative care with disease management, many people living with a chronic life-threatening illness either do not receive any palliative care service or receive services only in the last phase of their illness. In this article, I explore some of the reasons for failure to provide palliative care services and recommend some strategies to overcome these barriers, emphasizing the importance of describing palliative care accurately. I provide language which I hope will help health care professionals of all disciplines explain what palliative care has to offer and ensure wider access to palliative care, early in the course of their illness. PMID:28469439

Toward (-)-Enterocin: An Improved Cuprate Barbier Protocol To Overcome Strain and Sterical Hindrance.

PubMed

Rizzo, Antonio; Trauner, Dirk

2018-04-06

An approach toward (-)-enterocin, an antibiotic isolated from Streptomyces hygroscopicus, is described. Its compact, heavily oxidized protoadamantane core represents a daunting challenge for an efficient synthesis. Convergent assembly of its 2-oxabicyclo[3.3.1]nonane core with a cuprate-mediated Barbier reaction is disclosed. Its functionalization to a suitable substrate for a biomimetic aldol to close the final ring of the natural product is evaluated.

Harnessing atomistic simulations to predict the rate at which dislocations overcome obstacles

NASA Astrophysics Data System (ADS)

Saroukhani, S.; Nguyen, L. D.; Leung, K. W. K.; Singh, C. V.; Warner, D. H.

2016-05-01

Predicting the rate at which dislocations overcome obstacles is key to understanding the microscopic features that govern the plastic flow of modern alloys. In this spirit, the current manuscript examines the rate at which an edge dislocation overcomes an obstacle in aluminum. Predictions were made using different popular variants of Harmonic Transition State Theory (HTST) and compared to those of direct Molecular Dynamics (MD) simulations. The HTST predictions were found to be grossly inaccurate due to the large entropy barrier associated with the dislocation-obstacle interaction. Considering the importance of finite temperature effects, the utility of the Finite Temperature String (FTS) method was then explored. While this approach was found capable of identifying a prominent reaction tube, it was not capable of computing the free energy profile along the tube. Lastly, the utility of the Transition Interface Sampling (TIS) approach was explored, which does not need a free energy profile and is known to be less reliant on the choice of reaction coordinate. The TIS approach was found capable of accurately predicting the rate, relative to direct MD simulations. This finding was utilized to examine the temperature and load dependence of the dislocation-obstacle interaction in a simple periodic cell configuration. An attractive rate prediction approach combining TST and simple continuum models is identified, and the strain rate sensitivity of individual dislocation obstacle interactions is predicted.

Bacteriophage-encoded virion-associated enzymes to overcome the carbohydrate barriers during the infection process.

PubMed

Latka, Agnieszka; Maciejewska, Barbara; Majkowska-Skrobek, Grazyna; Briers, Yves; Drulis-Kawa, Zuzanna

2017-04-01

Bacteriophages are bacterial viruses that infect the host after successful receptor recognition and adsorption to the cell surface. The irreversible adherence followed by genome material ejection into host cell cytoplasm must be preceded by the passage of diverse carbohydrate barriers such as capsule polysaccharides (CPSs), O-polysaccharide chains of lipopolysaccharide (LPS) molecules, extracellular polysaccharides (EPSs) forming biofilm matrix, and peptidoglycan (PG) layers. For that purpose, bacteriophages are equipped with various virion-associated carbohydrate active enzymes, termed polysaccharide depolymerases and lysins, that recognize, bind, and degrade the polysaccharide compounds. We discuss the existing diversity in structural locations, variable architectures, enzymatic specificities, and evolutionary aspects of polysaccharide depolymerases and virion-associated lysins (VALs) and illustrate how these aspects can correlate with the host spectrum. In addition, we present methods that can be used for activity determination and the application potential of these enzymes as antibacterials, antivirulence agents, and diagnostic tools.

Breakthrough revisited: investigating the requirements for growth of dust beyond the bouncing barrier

NASA Astrophysics Data System (ADS)

Booth, Richard A.; Meru, Farzana; Lee, Man Hoi; Clarke, Cathie J.

2018-03-01

For grain growth to proceed effectively and lead to planet formation, a number of barriers to growth must be overcome. One such barrier, relevant for compact grains in the inner regions of the disc, is the `bouncing barrier' in which large grains (˜mm size) tend to bounce off each other rather than sticking. However, by maintaining a population of small grains, it has been suggested that cm-size particles may grow rapidly by sweeping up these small grains. We present the first numerically resolved investigation into the conditions under which grains may be lucky enough to grow beyond the bouncing barrier by a series of rare collisions leading to growth (so-called `breakthrough'). Our models support previous results, and show that in simple models breakthrough requires the mass ratio at which high-velocity collisions transition to growth instead of causing fragmentation to be low, ϕ ≲ 50. However, in models that take into account the dependence of the fragmentation threshold on mass ratio, we find that breakthrough occurs more readily, even if mass transfer is relatively inefficient. This suggests that bouncing may only slow down growth, rather than preventing growth beyond a threshold barrier. However, even when growth beyond the bouncing barrier is possible, radial drift will usually prevent growth to arbitrarily large sizes.

Barriers to use of refractive services in Mozambique.

PubMed

Thompson, Stephen; Naidoo, Kovin; Gonzalez-Alvarez, Carmen; Harris, Geoff; Chinanayi, Farai; Loughman, James

2015-01-01

Uncorrected refractive error remains a leading cause of visual impairment (VI) across the globe with Mozambique being no exception. The establishment of an optometry profession in Mozambique that is integrated into the public health system denotes significant progress with refractive services becoming available to the population. As the foundations of a comprehensive refractive service have now been established, this article seeks to understand what barriers may limit their uptake by the general population and inform decision making on improved service delivery. A community-based cross-sectional study using two-stage cluster sampling was conducted. Participants with VI were asked to identify barriers that were reflective of their experiences and perceptions of accessing refractive services. A total of 4601 participants were enumerated from 76 clusters in Nampula, Mozambique. A total of 1087 visually impaired participants were identified (884 with near and 203 with distance impairment). Cost was the most frequently cited barrier, identified by more than one in every two participants (53%). Other barriers identified included lack of felt need (20%), distance to travel (15%), and lack of awareness (13%). In general, no significant influence of sex or type of VI on barrier selection was found. Location had a significant impact on the selection of several barriers. Pearson χ analysis indicated that participants from rural areas were found to feel disadvantaged regarding the distance to services (p ≤ 0.001) and adequacy of hospital services (p = 0.001). For a comprehensive public sector refractive service to be successful in Mozambique, those planning its implementation must consider cost and affordability. A clear strategy for overcoming lack of felt need will also be needed, possibly in the form of improved advocacy and health promotion. The delivery of refractive services in more remote rural areas merits careful and comprehensive consideration.

Barriers to Use of Refractive Services in Mozambique

PubMed Central

Thompson, Stephen; Naidoo, Kovin; Gonzalez-Alvarez, Carmen; Harris, Geoff; Chinanayi, Farai; Loughman, James

2015-01-01

ABSTRACT Purpose Uncorrected refractive error remains a leading cause of visual impairment (VI) across the globe with Mozambique being no exception. The establishment of an optometry profession in Mozambique that is integrated into the public health system denotes significant progress with refractive services becoming available to the population. As the foundations of a comprehensive refractive service have now been established, this article seeks to understand what barriers may limit their uptake by the general population and inform decision making on improved service delivery. Methods A community-based cross-sectional study using two-stage cluster sampling was conducted. Participants with VI were asked to identify barriers that were reflective of their experiences and perceptions of accessing refractive services. A total of 4601 participants were enumerated from 76 clusters in Nampula, Mozambique. Results A total of 1087 visually impaired participants were identified (884 with near and 203 with distance impairment). Cost was the most frequently cited barrier, identified by more than one in every two participants (53%). Other barriers identified included lack of felt need (20%), distance to travel (15%), and lack of awareness (13%). In general, no significant influence of sex or type of VI on barrier selection was found. Location had a significant impact on the selection of several barriers. Pearson χ2 analysis indicated that participants from rural areas were found to feel disadvantaged regarding the distance to services (p ≤ 0.001) and adequacy of hospital services (p = 0.001). Conclusions For a comprehensive public sector refractive service to be successful in Mozambique, those planning its implementation must consider cost and affordability. A clear strategy for overcoming lack of felt need will also be needed, possibly in the form of improved advocacy and health promotion. The delivery of refractive services in more remote rural areas merits careful and

Buckling of thermally fluctuating spherical shells: Parameter renormalization and thermally activated barrier crossing

NASA Astrophysics Data System (ADS)

Baumgarten, Lorenz; Kierfeld, Jan

2018-05-01

We study the influence of thermal fluctuations on the buckling behavior of thin elastic capsules with spherical rest shape. Above a critical uniform pressure, an elastic capsule becomes mechanically unstable and spontaneously buckles into a shape with an axisymmetric dimple. Thermal fluctuations affect the buckling instability by two mechanisms. On the one hand, thermal fluctuations can renormalize the capsule's elastic properties and its pressure because of anharmonic couplings between normal displacement modes of different wavelengths. This effectively lowers its critical buckling pressure [Košmrlj and Nelson, Phys. Rev. X 7, 011002 (2017), 10.1103/PhysRevX.7.011002]. On the other hand, buckled shapes are energetically favorable already at pressures below the classical buckling pressure. At these pressures, however, buckling requires to overcome an energy barrier, which only vanishes at the critical buckling pressure. In the presence of thermal fluctuations, the capsule can spontaneously overcome an energy barrier of the order of the thermal energy by thermal activation already at pressures below the critical buckling pressure. We revisit parameter renormalization by thermal fluctuations and formulate a buckling criterion based on scale-dependent renormalized parameters to obtain a temperature-dependent critical buckling pressure. Then we quantify the pressure-dependent energy barrier for buckling below the critical buckling pressure using numerical energy minimization and analytical arguments. This allows us to obtain the temperature-dependent critical pressure for buckling by thermal activation over this energy barrier. Remarkably, both parameter renormalization and thermal activation lead to the same parameter dependence of the critical buckling pressure on temperature, capsule radius and thickness, and Young's modulus. Finally, we study the combined effect of parameter renormalization and thermal activation by using renormalized parameters for the energy

Measurements and Quasi-Quantum Modeling of the Steric Asymmetry and Parity Propensities in State-to-State Rotationally Inelastic Scattering of NO ( 2Π 1/2) with D 2

DOE PAGES

Taatjes, Craig A.; Gijsbertsen, Arjan; de Lange, Marc J. L.; ...

2007-06-02

In this paper, relative integrated cross sections are measured for spin-orbit-conserving, rotationally inelastic scattering of NO ( 2Π 1/2), hexapole-selected in the upper Λ-doublet level of the ground rotational state (j = 0.5), in collisions with D 2 at a nominal energy of 551 cm -1. The final state of the NO molecule is detected by laser-induced fluorescence (LIF). The state-selected NO molecule is oriented with either the N end or the O end toward the incoming D 2 molecule by application of a static electric field E in the scattering region. This field is directed parallel or antiparallel tomore » the relative velocity vector v. Comparison of signals taken for the different applied field directions gives the experimental steric asymmetry SA, defined by SA = (σ v↑↓E - σ v↑↑E)/(σ v↑↓E + σ v↑↑E), which is equal to within a factor of -1 to the molecular steric effect, S i→f ≡ (σ D2→NO - σ D2→ON)/(σ D2→NO + σ D2→ON). The dependence of the integral inelastic cross section on the incoming Λ-doublet component is also measured as a function of the final rotational (j final) and Λ-doublet (ε final) state. The measured steric asymmetries are similar to those previously observed for NO-He scattering. Spin-orbit manifold-conserving collisions exhibit a larger propensity for parity conservation than their NO-He counterparts. The results are interpreted in the context of the recently developed quasi-quantum treatment (QQT) of rotationally inelastic scattering. The QQT predictions can be inverted to obtain a fitted hard-shell potential that reproduces the experimental steric asymmetry; this fitted potential gives an empirical estimate of the anisotropy of the repulsive interaction between NO and D 2. Finally, QQT computation of the differential cross section using this simple model potential shows reasonable agreement with the measured differential cross sections.« less

Overcoming barriers to effective early parenting interventions for attention-deficit hyperactivity disorder (ADHD): parent and practitioner views

PubMed Central

Smith, E; Koerting, J; Latter, S; Knowles, M M; McCann, D C; Thompson, M; Sonuga-Barke, E J

2015-01-01

Background The importance of early intervention approaches for the treatment of attention-deficit hyperactivity disorder (ADHD) has been increasingly acknowledged. Parenting programmes (PPs) are recommended for use with preschool children with ADHD. However, low ‘take-up’ and high ‘drop-out’ rates compromise the effectiveness of such programmes within the community. Methods This qualitative study examined the views of 25 parents and 18 practitioners regarding currently available PPs for preschool children with ADHD-type problems in the UK. Semi-structured interviews were undertaken to identify both barriers and facilitators associated with programme access, programme effectiveness, and continued engagement. Results and conclusions Many of the themes mirrored previous accounts relating to generic PPs for disruptive behaviour problems. There were also a number of ADHD-specific themes. Enhancing parental motivation to change parenting practice and providing an intervention that addresses the parents' own needs (e.g. in relation to self-confidence, depression or parental ADHD), in addition to those of the child, were considered of particular importance. Comparisons between the views of parents and practitioners highlighted a need to increase awareness of parental psychological barriers among practitioners and for better programme advertising generally. Clinical implications and specific recommendations drawn from these findings are discussed and presented. PMID:24814640

Overcoming barriers to effective early parenting interventions for attention-deficit hyperactivity disorder (ADHD): parent and practitioner views.

PubMed

Smith, E; Koerting, J; Latter, S; Knowles, M M; McCann, D C; Thompson, M; Sonuga-Barke, E J

2015-01-01

The importance of early intervention approaches for the treatment of attention-deficit hyperactivity disorder (ADHD) has been increasingly acknowledged. Parenting programmes (PPs) are recommended for use with preschool children with ADHD. However, low 'take-up' and high 'drop-out' rates compromise the effectiveness of such programmes within the community. This qualitative study examined the views of 25 parents and 18 practitioners regarding currently available PPs for preschool children with ADHD-type problems in the UK. Semi-structured interviews were undertaken to identify both barriers and facilitators associated with programme access, programme effectiveness, and continued engagement. Many of the themes mirrored previous accounts relating to generic PPs for disruptive behaviour problems. There were also a number of ADHD-specific themes. Enhancing parental motivation to change parenting practice and providing an intervention that addresses the parents' own needs (e.g. in relation to self-confidence, depression or parental ADHD), in addition to those of the child, were considered of particular importance. Comparisons between the views of parents and practitioners highlighted a need to increase awareness of parental psychological barriers among practitioners and for better programme advertising generally. Clinical implications and specific recommendations drawn from these findings are discussed and presented. © 2014 The Authors. Child: Care, Health and Development published by John Wiley & Sons Ltd.

Hepatitis B Screening in Asian and Pacific Islanders: New Guidelines, Old Barriers.

PubMed

Nguyen, Cathina T; Lin, Steven Y

2015-10-01

Chronic hepatitis B virus (HBV) infection is a serious liver disease that disproportionately affects Asian and Pacific Islander immigrants. In May 2014, the U.S. Preventive Services Task Force released new HBV screening guidelines that expanded screening to non-pregnant adolescents and adults who were born in Asia and the Pacific Islands, and U.S.-born persons not vaccinated as infants whose parents were born in Central or Southeast Asia. Although the guidelines empower health care providers and community health workers to expand their screening efforts, old barriers to screening remain deeply rooted in this population. These barriers include cultural beliefs about wellness, myths and misconceptions about HBV, and lack of access to appropriate, culturally sensitive care. Through a combination of strategies--retooling the current health care workforce to be more culturally sensitive providers, involving oriental medicine practitioners in patient education, and engaging grassroots organizations--we can overcome barriers and take full advantage of the new HBV screening guidelines.

Barriers to nurse entrepreneurship: a study of the process model of entrepreneurship.

PubMed

Elango, B; Hunter, Gary L; Winchell, Mike

2007-04-01

The potential for nurse entrepreneurship to contribute to the effectiveness of healthcare delivery is well acknowledged, yet it has not been fully realized. Using the process model of entrepreneurship, we attempted to glean information from nursing professionals through focus groups on the barriers to starting a business. Two focus groups were used and expert moderators conducted these exercises. The first focus group included two hospital administrators, a nurse entrepreneur, an ophthalmology entrepreneur, and a dean of the nursing school familiar with nurse entrepreneurship. The second focus group used 20 students in a nurse practitioner program. The study findings indicate nurse practitioners and other nursing professionals do recognize the potential of nurse entrepreneurship. However, several barriers prevent them from exploiting the identified opportunity. While the barriers are significant, we believe they can be overcome with coordinated action by individual nurses, professional associations, and public policy initiatives. Several suggestions are offered to nurses seeking to become nurse entrepreneurs.

Sport Participation for Elite Athletes With Physical Disabilities: Motivations, Barriers, and Facilitators.

PubMed

McLoughlin, Gabriella; Weisman Fecske, Courtney; Castaneda, Yvette; Gwin, Candace; Graber, Kim

2017-10-01

There are many reasons why individuals are motivated to participate in sports. Less attention, however, is given for studying motivation and athlete development in adapted sport. The purpose of this study was to identify the motivations, facilitators, and barriers to sports participation of elite athletes with a physical disability. Participants (N = 23, 17 males, six females, mean age: 24.3 years) were recruited through online listservs, e-mails, and snowball sampling. A semistructured interview guide was employed. Analysis was conducted and grounded in self-determination theory and literature surrounding barriers and facilitators of sports participation. Through coding by multiple researchers, six themes emerged. Themes indicated that athletes attributed participation to constructs of self-determination theory as well as overcoming specific barriers such as cost, time constraints, and lack of opportunity. Among facilitators to their athletic development, there were empowerment and advocacy, increased health, college scholarships, and achieving performance-related goals.

Barriers to genuine consumer and carer participation from the perspectives of Australian systemic mental health advocates.

PubMed

Gee, Alison; McGarty, Craig; Banfield, Michelle

2016-06-01

Consumer and carer participation in mental health service development and evaluation has widespread nominal support. However, genuine and consistent participation remains elusive due to systemic barriers. This paper explores barriers to reform for mental health services from the perspectives of consumers and carers actively engaged in advocating for improvements in the mental health system. Qualitative research with two mental health systemic advocacy organisations analysed 17 strategic communication documents and nine interviews to examine barriers to reform and participation identified by consumer and carer advocates and staff. A number of individual-level barriers were described, however advocates gave more focus to systemic barriers, for which five themes emerged. These reflected lack of awareness, limited participation opportunities, slow progress for change, policy issues and mental health culture including stigma. Findings highlight systemic barriers to participation for consumer and carer advocates as a whole and the influence of these barriers on the individual experiences of those engaged in advocacy and representation work. Participants also emphasised the need for leadership to overcome some of these obstacles and move towards genuine consumer and carer participation and reform. Findings are discussed in the context of power within mental health systems.

Barriers of inter-organisational integration in vocational rehabilitation.

PubMed

Wihlman, Ulla; Lundborg, Cecilia Stålsby; Axelsson, Runo; Holmström, Inger

2008-06-19

A project of vocational rehabilitation was studied in Sweden between 1999 and 2002. The project included four public organisations: the social insurance office, the local health services, the municipal social service and the office of the state employment service. The aim of this paper was to analyse perceived barriers in the development of inter-organisational integration. Theories of inter-professional and inter-organisational integration, and theories on organisational change. In total, 51 semi-structured interviews and 14 focus group discussions were performed with actors within the project between 1999 and 2002. A thematic approach was used for the analysis of the data. THREE DIFFERENT MAIN THEMES OF BARRIERS EMERGED FROM THE DATA: A Uncertainty, B Prioritising own organisation and C Lack of communication. The themes are interconnected in an intricate web and hence not mutually exclusive. The barriers found are all related partly to organisational change in general and partly to the specific development of organisational integration. Prioritising of own organisation led to flaws in communication, which in turn led to a high degree of uncertainty within the project. This can be seen as a circular relationship, since uncertainty might increase focus on own organisation and lack of communication. A way to overcome these barriers would be to take the needs of the clients as a point of departure in the development of joint services and to also involve them in the development of inter-organisational integration.

Steric exclusion and protein conformation determine the localization of plasma membrane transporters.

PubMed

Bianchi, Frans; Syga, Łukasz; Moiset, Gemma; Spakman, Dian; Schavemaker, Paul E; Punter, Christiaan M; Seinen, Anne-Bart; van Oijen, Antoine M; Robinson, Andrew; Poolman, Bert

2018-02-05

The plasma membrane (PM) of Saccharomyces cerevisiae contains membrane compartments, MCC/eisosomes and MCPs, named after the protein residents Can1 and Pma1, respectively. Using high-resolution fluorescence microscopy techniques we show that Can1 and the homologous transporter Lyp1 are able to diffuse into the MCC/eisosomes, where a limited number of proteins are conditionally trapped at the (outer) edge of the compartment. Upon addition of substrate, the immobilized proteins diffuse away from the MCC/eisosomes, presumably after taking a different conformation in the substrate-bound state. Our data indicate that the mobile fraction of all integral plasma membrane proteins tested shows extremely slow Brownian diffusion through most of the PM. We also show that proteins with large cytoplasmic domains, such as Pma1 and synthetic chimera of Can1 and Lyp1, are excluded from the MCC/eisosomes. We hypothesize that the distinct localization patterns found for these integral membrane proteins in S. cerevisiae arises from a combination of slow lateral diffusion, steric exclusion, and conditional trapping in membrane compartments.

Patient and partner perspectives on patient-delivered partner screening: acceptability, benefits, and barriers.

PubMed

McBride, Kimberly R; Goldsworthy, Richard C; Fortenberry, J Dennis

2010-10-01

The study examined willingness to engage in patient-delivered partner screening (PDPS) and preferences for expedited partner services (EPS). Forty urban U.S. sexually transmitted infection (STI) clinic patients participated in individual mixed-methods interviews exploring EPS preferences and PDPS willingness. Most participants selected PDPS and PDPT together and uptake varied by patient–partner relationship closeness. For PDPS, several potentially important barriers and benefits were identified. Perceived benefits included improved sexual health for patients and their sexual partner(s) as well as convenience, privacy, and the potential to enhance trust between sexual partners. Perceived barriers included concerns about PDPS processes (e.g., time it would take to receive the result, risk of sample contamination), the accuracy of results, STI stigma and associated blame, lack of trust for a sexual partner, and the packaging/appearance of the screening kit. PDPS affords benefits and may overcome treatment barriers in some situations; however, it shares common PDPT barriers and has its own unique challenges. There are also concerns regarding how the offer of PDPS may interact with PDPT utilization.

How to address barriers to peritoneal dialysis in the elderly.

PubMed

Brown, Edwina A

2011-03-01

Older patients on dialysis have unique needs and characteristics and their outcomes vary from that of their younger counterparts. Comparatively fewer will start or be maintained on peritoneal dialysis (PD) compared to younger patients, despite the fact that hemodialysis is often poorly tolerated. Barriers to PD for older patients include poor vision, frailty, cognitive dysfunction, accommodation issues, and a bias from renal teams that older patients cannot do PD. The development of assisted PD can overcome many of these barriers. The ability of older patients to use PD as their dialysis modality should not be determined by whether they live in an area where the nephrologist is a PD enthusiast. All patients should be given nonbiased information so they can choose the dialysis modality that gives them the best quality of life and suits their and their family's lifestyle.

Evaluating Restorative Justice Circles of Support and Accountability: Can Social Support Overcome Structural Barriers?

PubMed

Bohmert, Miriam Northcutt; Duwe, Grant; Hipple, Natalie Kroovand

2018-02-01

In a climate in which stigmatic shaming is increasing for sex offenders as they leave prison, restorative justice practices have emerged as a promising approach to sex offender reentry success and have been shown to reduce recidivism. Criminologists and restorative justice advocates believe that providing ex-offenders with social support that they may not otherwise have is crucial to reducing recidivism. This case study describes the expressive and instrumental social support required and received, and its relationship to key outcomes, by sex offenders who participated in Circles of Support and Accountability (COSAs), a restorative justice, reentry program in Minnesota. In-depth interviews with re-entering sex offenders and program volunteers revealed that 75% of offenders reported weak to moderate levels of social support leaving prison, 70% reported receiving instrumental support in COSAs, and 100% reported receiving expressive support. Findings inform work on social support, structural barriers, and restorative justice programming during sex offender reentry.

Structure and Dynamics of Highly PEG-ylated Sterically Stabilized Micelles in Aqueous Media

PubMed Central

Vuković, Lela; Khatib, Fatima A.; Drake, Stephanie P.; Madriaga, Antonett; Brandenburg, Kenneth S.; Král, Petr; Onyuksel, Hayat

2011-01-01

Molecular assemblies of highly PEG-ylated phospholipids are important in many biomedical applications. We study sterically stabilized micelles (SSM) of self-assembled DSPE-PEG2000 in pure water and isotonic HEPES buffered saline solution. The observed SSM sizes of 2 – 15 nm largely depend on the solvent and the lipid concentration used. The critical micelle concentration (CMC) of DSPE-PEG2000 is ≈ 10 times higher in water than in buffer and the viscosity of the dispersion dramatically increases with the lipid concentration. To explain the experimentally observed results, we perform atomistic molecular dynamics simulations of the solvated SSM. Our modeling reveal that the observed assemblies have very different aggregation numbers of Nagg ≈ 90 (saline solution) and Nagg < 8 (water), due to very different screening of their charged −PO4− groups. We also demonstrate that the micelle cores can inflate and their corona highly fluctuate, allowing thus storage and delivery of molecules with different chemistry. PMID:21780810

Structure and dynamics of highly PEG-ylated sterically stabilized micelles in aqueous media.

PubMed

Vuković, Lela; Khatib, Fatima A; Drake, Stephanie P; Madriaga, Antonett; Brandenburg, Kenneth S; Král, Petr; Onyuksel, Hayat

2011-08-31

Molecular assemblies of highly PEG-ylated phospholipids are important in many biomedical applications. We have studied sterically stabilized micelles (SSMs) of self-assembled DSPE–PEG2000 in pure water and isotonic HEPES-buffered saline solution. The observed SSM sizes of 2–15 nm largely depend on the solvent and the lipid concentration used. The critical micelle concentration of DSPE–PEG2000 is 10 times higher in water than in buffer, and the viscosity of the dispersion dramatically increases with the lipid concentration. To explain the experimentally observed results, we performed atomistic molecular dynamics simulations of solvated SSMs. Our modeling revealed that the observed assemblies have very different aggregation numbers (N(agg) ≈ 90 in saline solution and N(agg) < 8 in water) because of very different screening of their charged PO4(–) groups. We also demonstrate that the micelle cores can inflate and their coronas can fluctuate strongly, thus allowing storage and delivery of molecules with different chemistries.

Shape-Persistent, Sterically Crowded Star Mesogens: From Exceptional Columnar Dimer Stacks to Supermesogens.

PubMed

Lehmann, Matthias; Maier, Philipp

2015-08-10

Hexasubstituted C3 -symmetric benzenes with three oligophenylenevinylene (OPV) arms and three pyridyl or phenyl substituents are shape-persistent star mesogens that are sterically crowded in the center. Such molecular structures possess large void spaces between their arms, which have to be filled in condensed phases. For the neat materials, this is accomplished by an exceptional formation of dimers and short-range helical packing in columnar mesophases. The mesophase is thermodynamically stable for the pyridyl compound. Only this derivative forms filled star-shaped supermesogens in the presence of various carboxylic acids. The latter do not arrange as dimers, but as monomers along the columnar stacks. In this liquid crystal (LC) phase, the guests are completely enclosed by the hosts. Therefore, the host can be regarded as a new LC endoreceptor, which allows the design of columnar functional structures in the future. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Overcoming Workplace Barriers: A Focus Group Study Exploring African American Mothers' Needs for Workplace Breastfeeding Support.

PubMed

Johnson, Angela Marie; Kirk, Rosalind; Muzik, Maria

2015-08-01

Persistent racial disparities in breastfeeding show that African American women breastfeed at the lowest rates. Return to work is a critical breastfeeding barrier for African American women who return to work sooner than other ethnic groups and more often encounter unsupportive work environments. They also face psychosocial burdens that make breastfeeding at work uniquely challenging. Participants share personal struggles with combining paid employment and breastfeeding and suggest workplace and personal support strategies that they believe will help continue breastfeeding after a return to work. To explore current perspectives on ways to support African American mothers' workplace breastfeeding behavior. Pregnant African American women (n = 8), African American mothers of infants (n = 21), and lactation support providers (n = 9) participated in 1 of 6 focus groups in the Greater Detroit area. Each focus group audiotape was transcribed verbatim. Thematic analysis was used to inductively analyze focus group transcripts and field notes. Focus groups explored thoughts, perceptions, and behavior on interventions to support African American women's breastfeeding. Participants indicate that they generally believed breastfeeding was a healthy option for the baby; however, paid employment is a critical barrier to successful breastfeeding for which mothers receive little help. Participants felt breastfeeding interventions that support working African American mothers should include education and training for health care professionals, regulation and enforcement of workplace breastfeeding support policies, and support from peers who act as breastfeeding role models. Culturally appropriate interventions are needed to support breastfeeding among working African American women. © The Author(s) 2015.

Overcoming Workplace Barriers: A Focus Group Study Exploring African American Mothers' Needs for Workplace Breastfeeding Support

PubMed Central

Johnson, Angela Marie; Kirk, Rosalind; Muzik, Maria

2015-01-01

Background Persistent racial disparities in breastfeeding show that African American women breastfeed at the lowest rates. Return to work is a critical breastfeeding barrier for African American women who return to work sooner than other ethnic groups and more often encounter unsupportive work environments. They also face psychosocial burdens that make breastfeeding at work uniquely challenging. Participants share personal struggles with combining paid employment and breastfeeding and suggest workplace and personal support strategies that they believe will help continue breastfeeding after a return to work. Objective To explore current perspectives on ways to support African American mothers' workplace breastfeeding behavior. Methods Pregnant African American women (n = 8), African American mothers of infants (n = 21), and lactation support providers (n = 9) participated in 1 of 6 focus groups in the Greater Detroit area. Each focus group audiotape was transcribed verbatim. Thematic analysis was used to inductively analyze focus group transcripts and field notes. Focus groups explored thoughts, perceptions, and behavior on interventions to support African American women's breastfeeding. Results Participants indicate that they generally believed breastfeeding was a healthy option for the baby; however, paid employment is a critical barrier to successful breastfeeding for which mothers receive little help. Participants felt breastfeeding interventions that support working African American mothers should include education and training for health care professionals, regulation and enforcement of workplace breastfeeding support policies, and support from peers who act as breastfeeding role models. Conclusion Culturally appropriate interventions are needed to support breastfeeding among working African American women. PMID:25714345

Bryozoan diversity around the Falkland and South Georgia Islands: Overcoming Antarctic barriers.

PubMed

Figuerola, Blanca; Barnes, David K A; Brickle, Paul; Brewin, Paul E

2017-05-01

There are a number of remote archipelagos distributed between 45 and 60 °S. The biota of these islands provide useful information to describe and understand patterns in biodiversity and biogeography as well as potential impacts of climate change on marine ecosystems. They are in key locations either side of the Polar Front but also have limited influence from human activities. Here we investigate one taxon, bryozoans, on South Atlantic shelf habitats of the Falkland (FI) and the sub-Antarctic island of South Georgia (SG). We present new data on spatial distribution in these islands, as well as an analysis of the bryozoological similarities between these and neighbouring regions. A total of 85 species of cheilostome bryozoans (351 samples) were found, belonging to 33 genera, including 18 potentially new genera and 23 new species. Remarkably 65% and 41% of species were reported for the first time at FI and SG, respectively. The highest and the lowest value of species richness and species/genus ratio were found at East (EFI) and West Falkland (WFI), respectively, likely showing a tendency for stronger intrageneric competition. New data from this study were jointly analysed with data from the literature and existing databases, revealing new bathymetric ranges in 32 species. The biogeographic affinities of the bryozoans found give further evidence of the hypothesis of sequential separation of Gondwana and support the changing concept that although the Polar Front acts as a circumpolar biogeographic barrier it is not as impermeable as originally thought. Potential dispersal mechanisms are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beating the Language Barrier in Science Education: In-Service Educators' Coping with Slow Learners in Mauritius

ERIC Educational Resources Information Center

Cyparsade, Mohun; Auckloo, Pritee; Belath, Ismut; Dookhee, Helina; Hurreeram, Navin

2013-01-01

This study describes how in-service teachers in the pre-vocational sector in Mauritius adopted specific strategies to overcome the language barrier in the learning of science (Van Driel, Verloop & de Vos, 1998). Students of form III were taught few basic ideas related to "Earth & Space" through the use of role play and ICT. The…

Microscopic localization of sterically stabilized liposomes in colon carcinoma-bearing mice.

PubMed

Huang, S K; Lee, K D; Hong, K; Friend, D S; Papahadjopoulos, D

1992-10-01

Using light and electron microscopy, we investigated the in vivo distribution of liposomes sterically stabilized by specific lipids which prolong their circulation in blood. Tissue distribution of sterically stabilized liposomes composed of distearoyl phosphatidylcholine:cholesterol:monosialoganglioside GM1 (10:5:1)-encapsulated 67Ga-Desferal indicates that more than 30% of liposomes still remain in the blood at 24 h after tail vein injection. Moreover, such liposomes accumulated in tumors (C-26 colon carcinoma cells implanted s.c.), reaching almost the same level of uptake as liver (approximately 20% injected dose/g tissue). The microscopic localization of liposomes labeled with encapsulated colloidal gold or rhodamine-labeled dextran coincided well with the tissue distribution. To evaluate circulation parameters, two sizes of gold-containing egg phosphatidylcholine:cholesterol:distearoyl phosphatidylethanolamine (derivatized at its amino position with a 1900 molecular weight segment of polyethylene glycol) (10:5:0.8) liposomes were injected. The plasma was examined by electron microscopy of negative-stained preparations at 0.5, 4, and 24 h after liposome injection. It was found that the ratio of small (less than 100 nm diameter) to large (greater than 100 nm) liposomes increased with time, indicating a much faster clearance of the larger liposomes. To detect the localization of liposomes in various tissues, appropriate samples were fixed 24 h after the injection of gold-containing liposomes (between 80 and 100 nm in diameter) composed of egg phosphatidylcholine:cholesterol:monosialoganglioside GM1 (10:5:1) or egg phosphatidylcholine:cholesterol:derivatized distearoyl phosphatidylethanolamine. The tissues examined for this study included normal liver, bone marrow, and implanted neoplasms. Silver-enhanced colloidal gold was found predominantly within Kupffer cells in the normal liver and within macrophages in the bone marrow. Rarely were any silver-enhanced gold

Patient-perceived barriers to lifestyle interventions in cirrhosis.

PubMed

Ney, Michael; Gramlich, Leah; Mathiesen, Vanessa; Bailey, Robert J; Haykowsky, Mark; Ma, Mang; Abraldes, Juan G; Tandon, Puneeta

2017-01-01

Sarcopenia, muscle weakness, and physical frailty are independent predictors of mortality in cirrhosis. These adverse prognostic factors are potentially modifiable with lifestyle interventions, including adequate nutritional intake and physical activity. Our aim was to identify patient-perceived barriers and enablers to these interventions. Adult patients with cirrhosis were prospectively recruited from two tertiary care liver clinics. Patients were excluded if they had hepatocellular carcinoma beyond transplant criteria, other active malignancy, or advanced chronic disease. A total of 127 patients (mean age: 60 ± 9 years, 58% males, and 48% with Child-Pugh-B/C (CP-B/C) disease) were included. Two-thirds of the patients had cirrhosis related to alcohol or hepatitis C. CP-B/C patients were more likely to take oral nutritional supplements (56% vs 29%) and less likely to consume animal protein daily (66% vs 85%) when compared to CP-A patients. Early satiety, altered taste, and difficulty in buying/preparing meals were more common in CP-B/C patients and even present in 20-30% of CP-A patients. Most patients reported adequate funds to purchase food. As quantified by the International Physical Activity Questionnaire-Short Form, 47% reported low activity levels, with no significant differences between groups. CP-B/C patients were more fatigued with exercise, however, overall Exercise Benefits/Barriers Scale scores were similar across groups. Barriers to nutritional intake and physical activity are common in cirrhosis and should be evaluated and treated in all patients. Asking simple screening questions in clinic and referring at-risk patients to expert multidisciplinary providers is a reasonable strategy to address these barriers. Future research should evaluate techniques to overcome modifiable barriers and enhance enablers.

Observation of steric hindrance effect controlling crystal packing structures and physical properties in three new isomeric nitronyl nitroxide radicals

NASA Astrophysics Data System (ADS)

Zhao, Hai-Rong; Sun, Jia-Sen; Sui, Yun-Xia; Ren, Xiao-Ming; Yao, Bin-Qian; Shen, Lin-Jiang; Meng, Qing-Jin

2009-07-01

Three isomeric nitronyl nitroxide radical compounds, 2-[ n-( N-benzyl)pyridinium]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide bromide ( n = 2, 3 and 4 for 1, 2 and 3, respectively), have been synthesized and structurally characterized. The influence of steric hindrance on the molecular packing structures and physical properties has been observed. In the radical 1, such steric hindrance leads to a folding conformation of the imidazoline and benzene rings and the intramolecular C-H…π interaction between the methyl group and the benzene ring. There is no such effect in 2 and 3. In crystal of 2, there are the intermolecular C-H…π between methyl groups and benzene ring and intermolecular π…π stacking interaction between pyridine and benzene rings. Crystal of 2 with a chiral space group P2 12 12 1 shows the SHG response about 0.4 times as that of urea. In crystal of 3, there are three symmetry-independent radical molecules, which form an unusually six-membered supramolecular ring via intermolecular O…π interactions. For the solid sample of 3, the X-band EPR exhibits an axially symmetric signal and magnetic susceptibility data suggest intermolecular antiferromagnetic (AFM) coupling interactions and very weak intermolecular ferromagnetic (FM) coupling interactions which is more likely caused by magnetic anisotropy, while measurements of both 1 and 2 show isotropic X-band EPR signals and simple Currie-Weiss magnetic behavior.

Physical activity barriers and facilitators among working mothers and fathers.

PubMed

Mailey, Emily L; Huberty, Jennifer; Dinkel, Danae; McAuley, Edward

2014-06-27

The transition to parenthood is consistently associated with declines in physical activity. In particular, working parents are at risk for inactivity, but research exploring physical activity barriers and facilitators in this population has been scarce. The purpose of this study was to qualitatively examine perceptions of physical activity among working parents. Working mothers (n = 13) and fathers (n = 12) were recruited to participate in one of four focus group sessions and discuss physical activity barriers and facilitators. Data were analyzed using immersion/crystallization in NVivo 10. Major themes for barriers included family responsibilities, guilt, lack of support, scheduling constraints, and work. Major themes for facilitators included being active with children or during children's activities, being a role model for children, making time/prioritizing, benefits to health and family, and having support available. Several gender differences emerged within each theme, but overall both mothers and fathers reported their priorities had shifted to focus on family after becoming parents, and those who were fitting in physical activity had developed strategies that allowed them to balance their household and occupational responsibilities. The results of this study suggest working mothers and fathers report similar physical activity barriers and facilitators and would benefit from interventions that teach strategies for overcoming barriers and prioritizing physical activity amidst the demands of parenthood. Future interventions might consider targeting mothers and fathers in tandem to create an optimally supportive environment in the home.

Physical activity barriers and facilitators among working mothers and fathers

PubMed Central

2014-01-01

Background The transition to parenthood is consistently associated with declines in physical activity. In particular, working parents are at risk for inactivity, but research exploring physical activity barriers and facilitators in this population has been scarce. The purpose of this study was to qualitatively examine perceptions of physical activity among working parents. Methods Working mothers (n = 13) and fathers (n = 12) were recruited to participate in one of four focus group sessions and discuss physical activity barriers and facilitators. Data were analyzed using immersion/crystallization in NVivo 10. Results Major themes for barriers included family responsibilities, guilt, lack of support, scheduling constraints, and work. Major themes for facilitators included being active with children or during children’s activities, being a role model for children, making time/prioritizing, benefits to health and family, and having support available. Several gender differences emerged within each theme, but overall both mothers and fathers reported their priorities had shifted to focus on family after becoming parents, and those who were fitting in physical activity had developed strategies that allowed them to balance their household and occupational responsibilities. Conclusions The results of this study suggest working mothers and fathers report similar physical activity barriers and facilitators and would benefit from interventions that teach strategies for overcoming barriers and prioritizing physical activity amidst the demands of parenthood. Future interventions might consider targeting mothers and fathers in tandem to create an optimally supportive environment in the home. PMID:24974148

Drug delivery in overcoming the blood–brain barrier: role of nasal mucosal grafting

PubMed Central

Marianecci, Carlotta; Rinaldi, Federica; Hanieh, Patrizia Nadia; Di Marzio, Luisa; Paolino, Donatella; Carafa, Maria

2017-01-01

The blood–brain barrier (BBB) plays a fundamental role in protecting and maintaining the homeostasis of the brain. For this reason, drug delivery to the brain is much more difficult than that to other compartments of the body. In order to bypass or cross the BBB, many strategies have been developed: invasive techniques, such as temporary disruption of the BBB or direct intraventricular and intracerebral administration of the drug, as well as noninvasive techniques. Preliminary results, reported in the large number of studies on the potential strategies for brain delivery, are encouraging, but it is far too early to draw any conclusion about the actual use of these therapeutic approaches. Among the most recent, but still pioneering, approaches related to the nasal mucosa properties, the permeabilization of the BBB via nasal mucosal engrafting can offer new potential opportunities. It should be emphasized that this surgical procedure is quite invasive, but the implication for patient outcome needs to be compared to the gold standard of direct intracranial injection, and evaluated whilst keeping in mind that central nervous system diseases and lysosomal storage diseases are chronic and severely debilitating and that up to now no therapy seems to be completely successful. PMID:28184152

Physical activity preferences, motivators, barriers and attitudes of adults with mental illness.

PubMed

Chapman, Justin J; Fraser, Sarah J; Brown, Wendy J; Burton, Nicola W

2016-10-01

Adults with mental illness may have specific attitudes toward physical activity (PA). To assess the PA attitudes of non-institutionalised adults with mental illness, and associations with psychological distress. Participants completed questionnaires on activity preferences (type, context and sources of support), motivators, barriers and attitudes toward personal training (PT). Relationships between responses and distress were assessed using logistic regressions. One-hundred forty-two participants completed the questionnaires. PA context preferences included activities done close to home, outdoors, with professional instruction, with people of the same ability, as part of a healthy lifestyle program and with a social component. The most commonly endorsed source of support was an exercise instructor. Most respondents had never received PT; however, PT had high acceptability. Common barriers included poor physical and mental health, and lack of money. Distress was positively associated with barriers of poor mental health, tiredness, disorganisation, exhaustion and being shy/embarrassed (p ≤ 0.001). Local outdoor walking groups that include social and healthy lifestyle components, and that are led by an exercise instructor who can provide support for overcoming barriers, may best meet PA interests of this group. PT could be an acceptable method for offering individualised support.

Multifaceted catalytic hydrogenation of amides via diverse activation of a sterically confined bipyridine-ruthenium framework.

PubMed

Miura, Takashi; Naruto, Masayuki; Toda, Katsuaki; Shimomura, Taiki; Saito, Susumu

2017-05-16

Amides are ubiquitous and abundant in nature and our society, but are very stable and reluctant to salt-free, catalytic chemical transformations. Through the activation of a "sterically confined bipyridine-ruthenium (Ru) framework (molecularly well-designed site to confine adsorbed H 2 in)" of a precatalyst, catalytic hydrogenation of formamides through polyamide is achieved under a wide range of reaction conditions. Both C=O bond and C-N bond cleavage of a lactam became also possible using a single precatalyst. That is, catalyst diversity is induced by activation and stepwise multiple hydrogenation of a single precatalyst when the conditions are varied. The versatile catalysts have different structures and different resting states for multifaceted amide hydrogenation, but the common structure produced upon reaction with H 2 , which catalyzes hydrogenation, seems to be "H-Ru-N-H."

Identifying and Overcoming Critical Barriers to Widespread Second Use of PEV Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neubauer, J.; Smith, K.; Wood, E.

2015-02-01

Both the market penetration of plug-in electric vehicles (PEVs) and deployment of grid-connected energy storage systems are presently restricted by the high cost of batteries. Battery second use (B2U) strategies--in which a single battery first serves an automotive application, then is redeployed into a secondary market--could help address both issues by reducing battery costs to the primary (automotive) and secondary (electricity grid) users. This study investigates the feasibility of and major barriers to the second use of lithium-ion PEV batteries by posing and answering the following critical B2U questions: 1. When will used automotive batteries become available, and how healthymore » will they be? 2. What is required to repurpose used automotive batteries, and how much will it cost? 3. How will repurposed automotive batteries be used, how long will they last, and what is their value? Advanced analysis techniques are employed that consider the electrical, thermal, and degradation response of batteries in both the primary (automotive) and secondary service periods. Second use applications are treated in detail, addressing operational requirements, economic value, and market potential. The study concludes that B2U is viable and could provide considerable societal benefits due to the large possible supply of repurposed automotive batteries and substantial remaining battery life following automotive service. However, the only identified secondary market large enough to consume the supply of these batteries (utility peaker plant replacement) is expected to be a low margin market, and thus B2U is not expected to affect the upfront cost of PEVs.« less

Self-sampling for cervical screening: could it overcome some of the barriers to the Pap test?

PubMed

Mullins, Robyn; Scalzo, Katherine; Sultana, Farhana

2014-12-01

To determine which groups of women would be most likely to take part in self-sampling for cervical screening, and what they perceive as the key barriers and benefits to self-sampling. A random sample of 3000 women aged 18-69 in Victoria, Australia, were asked questions about "taking their own Pap test" in a telephone survey about cervical screening; 2526 answered the questions about self-sampling. The terminology "Pap test" was used in questions, due to the very low understanding of HPV and its link to cervical cancer. One-third of women (34.0%) indicated they would prefer to self-sample, 57.2% would not and 8.7% were unsure. Preference for self-sampling was significantly stronger among women who had not had a Pap test for more than three years (64.8%, p < .001) or who had never had one (62.1%, p < .001), compared with those up-to-date (27.0%). Convenience was a key benefit (37.8%), as was less embarrassment (31.5%). For those who did not want to self-sample or were unsure, key factors included professionals being more skilled (53.4% and 28.2% respectively), and doubts about being able to do it properly (28.9% and 23.6%). Self-sampling was most popular among women who needed to have a Pap test, and could potentially reach some women who are not participating appropriately in cervical screening. Key barriers to participation could be addressed by providing information about the test being for HPV, and being easier to do properly than a Pap test. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Mucosal Vaccination Overcomes the Barrier to Recombinant Vaccinia Immunization Caused by Preexisting Poxvirus Immunity

NASA Astrophysics Data System (ADS)

Belyakov, Igor M.; Moss, Bernard; Strober, Warren; Berzofsky, Jay A.

1999-04-01

Overcoming preexisting immunity to vaccinia virus in the adult population is a key requirement for development of otherwise potent recombinant vaccinia vaccines. Based on our observation that s.c. immunization with vaccinia induces cellular and antibody immunity to vaccinia only in systemic lymphoid tissue and not in mucosal sites, we hypothesized that the mucosal immune system remains naive to vaccinia and therefore amenable to immunization with recombinant vaccinia vectors despite earlier vaccinia exposure. We show that mucosal immunization of vaccinia-immune BALB/c mice with recombinant vaccinia expressing HIV gp160 induced specific serum antibody and strong HIV-specific cytotoxic T lymphocyte responses. These responses occurred not only in mucosal but also in systemic lymphoid tissue, whereas systemic immunization was ineffective under these circumstances. In this context, intrarectal immunization was more effective than intranasal immunization. Boosting with a second dose of recombinant vaccinia was also more effective via the mucosal route. The systemic HIV-specific cytotoxic T lymphocyte response was enhanced by coadministration of IL-12 at the mucosal site. These results also demonstrate the independent compartmentalization of the mucosal versus systemic immune systems and the asymmetric trafficking of lymphocytes between them. This approach to circumvent previous vaccinia immunity may be useful for induction of protective immunity against infectious diseases and cancer in the sizable populations with preexisting immunity to vaccinia from smallpox vaccination.

Preparation of metallic cation conducting polymers based on sterically hindered phenols containing polymeric systems

DOEpatents

Skotheim, Terje A.; Okamoto, Yoshiyuki; Lee, Hung S.

1989-01-01

The present invention relates to ion-conducting solvent-free polymeric systems characterized as being cationic single ion conductors. The solvent-free polymer electrolytes comprise a flexible polymer backbone to which is attached a metal salt, such as a lithium, sodium or potassium salt, of a sterically hindered phenol. The solid polymer electrolyte may be prepared either by (1) attaching the hindered phenol directly to a flexible polymeric backbone, followed by neutralization of the phenolic OH's or (2) reacting the hindered phenol with a polymer precursor which is then polymerized to form a flexible polymer having phenolic OH's which are subsequently neutralized. Preferably the hindered phenol-modified polymeric backbone contains a polyether segment. The ionic conductivity of these solvent-free polymer electrolytes has been measured to be in the range of 10.sup.-4 to 10.sup.-7 S cm.sup.-1 at room temperature.

Preparation of metallic cation conducting polymers based on sterically hindered phenols containing polymeric systems

DOEpatents

Skotheim, T.A.; Okamoto, Yoshiyuki; Lee, H.S.

1989-11-21

The present invention relates to ion-conducting solvent-free polymeric systems characterized as being cationic single ion conductors. The solvent-free polymer electrolytes comprise a flexible polymer backbone to which is attached a metal salt, such as a lithium, sodium or potassium salt, of a sterically hindered phenol. The solid polymer electrolyte may be prepared either by (1) attaching the hindered phenol directly to a flexible polymeric backbone, followed by neutralization of the phenolic OH's or (2) reacting the hindered phenol with a polymer precursor which is then polymerized to form a flexible polymer having phenolic OH's which are subsequently neutralized. Preferably the hindered phenol-modified polymeric backbone contains a polyether segment. The ionic conductivity of these solvent-free polymer electrolytes has been measured to be in the range of 10[sup [minus]4] to 10[sup [minus]7] S cm[sup [minus]1] at room temperature.

Barriers to Participation of Women in Technological Education and the Role of Distance Education. Occasional Paper No. 1.

ERIC Educational Resources Information Center

Evans, Karen

Throughout the world, women are underrepresented in technical fields as a result of the segmentation of the labor market and the internalization of expectations for women. Distance education can make an important contribution in overcoming barriers to women's participation in technology in the developed and developing world. The Open University in…

Perceived barriers to and benefits of attending a stop smoking course during pregnancy.

PubMed

Ussher, Michael; Etter, Jean-Francois; West, Robert

2006-06-01

During pregnancy, the uptake of smoking cessation courses is very low. We assessed perceived barriers to and benefits of attending a cessation course during pregnancy. A decisional-balance questionnaire was devised, including 10 statements reflecting benefits of attending a cessation course and 10 statements of barriers to attendance. The questionnaire was delivered via the Internet and targeted pregnant smokers/recent ex-smokers. Participants completed the questionnaire on a single occasion, indicating their agreement with each statement. Among 443 respondents, the most frequently endorsed barriers were 'Being afraid of disappointing myself if I failed' (54%) and not tending to seek help for this sort of thing (41%). The most frequently endorsed benefits were advice about cigarette cravings (74%) and praise and encouragement with quitting (71%). A greater interest in receiving help with quitting from a counselor was significantly associated with: being older, lower income, husband/partner advising cessation and less confidence in quitting. Pregnant smokers perceive many benefits of smoking cessation courses. However, these women also perceive many barriers to attendance and studies are needed to evaluate interventions for overcoming such barriers. Smoking cessation services need to address the perceived barriers to attending stop smoking courses during pregnancy, to publicise the benefits of these courses and to target women who feel that they cannot quit without this type of support.

Controlled growth of aligned carbon nanotube using pulsed glow barrier discharge

NASA Astrophysics Data System (ADS)

Nozaki, Tomohiro; Kimura, Yoshihito; Okazaki, Ken

2002-10-01

We first achieved a catalytic growth of aligned carbon nanotube (CNT) using atmospheric pressure pulsed glow barrier discharge combined with DC bias (1000 V). Aligned CNT can grow with the directional electric field, and this is a big challenge in barrier discharges since dielectric barrier does not allow DC bias and forces to use AC voltage to maintain stable plasma conditions. To overcome this, we developed a power source generating Gaussian-shape pulses at 20 kpps with 4% duty, and DC bias was applied to the GND electrode where Ni-, Fe-coated substrate existed. With positive pulse, i.e. substrate was the cathode, random growth of CNT was observed at about 10^9 cm-2. Growth rate significantly reduced when applied negative pulse; Negative glow formation near substrate is essential for sufficient supply of radical species to the catalyst. If -DC was biased, aligned CNT with 20 nm was synthesized because negative bias enhanced negative glow formation. Interestingly, 2 to 3 CNTs stuck each other with +DC bias, resulting in 50-70 nm and non-aligned CNT. Atmospheric pressure glow barrier discharges can be highly controlled and be a potential alternative to vacuum plasmas for CVD, micro-scale, nano-scale fabrication.

Using community-based participatory research to identify potential interventions to overcome barriers to adolescents’ healthy eating and physical activity

PubMed Central

Goh, Ying-Ying; Sipple-Asher, Bessie Ko; Uyeda, Kimberly; Hawes-Dawson, Jennifer; Olarita-Dhungana, Josephina; Ryan, Gery W.; Schuster, Mark A.

2010-01-01

Using a community-based participatory research approach, we explored adolescent, parent, and community stakeholder perspectives on barriers to healthy eating and physical activity, and intervention ideas to address adolescent obesity. We conducted 14 adolescent focus groups (n = 119), 8 parent focus groups (n = 63), and 28 interviews with community members (i.e., local experts knowledgeable about youth nutrition and physical activity). Participants described ecological and psychosocial barriers in neighborhoods (e.g., lack of accessible nutritious food), in schools (e.g., poor quality of physical education), at home (e.g., sedentary lifestyle), and at the individual level (e.g., lack of nutrition knowledge). Participants proposed interventions such as nutrition classes for families, addition of healthy school food options that appeal to students, and non-competitive physical education activities. Participants supported health education delivered by students. Findings demonstrate that community-based participatory research is useful for revealing potentially feasible interventions that are acceptable to community members. PMID:19544091

Barriers and Solutions to Fieldwork Education in Hand Therapy.

PubMed

Short, Nathan; Sample, Shelby; Murphy, Malachi; Austin, Brittany; Glass, Jillian

2017-08-09

Survey. Fieldwork education is a vital component of training the next generation of CHTs. Barriers and solutions to fieldwork rotations in hand therapy are examined, as well as proposed solutions, including recommendations for student preparation. This descriptive study examined barriers for certified hand therapist clinicians to accept students for clinical rotations and clinicians' preferences for student preparation before a rotation in a hand setting. A survey was developed, peer reviewed, and distributed using the electronic mailing list of the Hand Therapy Certification Commission via SurveyMonkey. Aggregate responses were analyzed to identify trends including barriers to student clinical rotations and recommendations for students to prepare for hand rotations. A total of 2080 participants responded to the survey, representing a 37% response rate. Common logistical barriers were identified for accepting students such as limited clinical time and space. Many clinicians (32% agree and 8% strongly agree) also felt that the students lack the clinical knowledge to be successful. Areas of knowledge, skill set, and experience were surveyed for development before a clinical rotation in a hand setting. Most respondents (74%) reported increased likelihood of accepting a student with the recommended preparation. Novel qualitative responses to improve clinical experiences are presented as well. Student preparation before a clinical rotation in a hand setting appears to be a significant barrier based on the survey results. Areas of recommended knowledge, skill set, and experience may serve to guide both formal and informal methods of student preparation before a hand-specific clinical rotation to facilitate knowledge translation from experienced certified hand therapists to the next generation. Although logistical barriers may be difficult to overcome, hand-specific preparation based on clinician' recommendations may facilitate student acceptance and success in hand

Barriers to the use of genetic information for the development of new epilepsy treatments.

PubMed

Ferraro, Thomas N

2016-01-01

Genetic analysis is providing new information on the biological basis of epilepsy at a rapid pace; this article identifies factors acting as major barriers to use of these data for therapy development. Disease heterogeneity is a primary obstacle since so many genes can cause or predispose to epilepsy and the clinical presentation of epilepsy is so diverse, thus making it difficult to define the most therapeutically relevant targets. Further, many epilepsy genes affect brain development, an observation that represents a barrier unto itself given the challenge of reversing or preventing genetically mediated alterations of brain pathway formation. Finally, the lack of appropriate models for testing new therapies is also recognized as a fundamental limitation. Overcoming these barriers will be aided by full characterization of the genetic landscape of epilepsy, elucidation of key pathway points for therapeutic intervention and creation of unique experimental models to validate results.

Trench Safety–Using a Qualitative Approach to Understand Barriers and Develop Strategies to Improve Trenching Practices

PubMed Central

FLYNN, MICHAEL A.; SAMPSON, JULIE M.

2015-01-01

Despite efforts to ensure workplace safety and health, injuries and fatalities related to trenching and excavation remain alarmingly high in the construction industry. Because properly installed trenching protective systems can potentially reduce the significant number of trenching fatalities, there is clearly a need to identify the barriers to the use of these systems and to develop strategies to ensure these systems are utilized consistently. The current study reports on the results of focus groups with construction workers and safety management personnel to better understand these barriers and to identify solutions. The results suggest several factors, from poor planning to pressures from experienced workers and supervisors, which present barriers to safe trenching practices. Based on the results, it is recommended that safety trainings incorporate unique messages for new workers, experienced workers and management in an effort to motivate each group to work safely as well as provide them with solutions to overcome the identified barriers. PMID:26550006

Barriers and Facilitators of African American Participation in Alzheimer’s Disease Biomarker Research

PubMed Central

Williams, Monique M.; Scharff, Darcell P.; Mathews, Katherine J.; Hoffsuemmer, Jonathan S.; Jackson, Pamela; Morris, John C.; Edwards, Dorothy F.

2010-01-01

African Americans experience a greater risk of Alzheimer’s disease (AD), but are underrepresented in AD research. Our study examined barriers and facilitators of AD research participation among African Americans. Investigators conducted 11 focus groups with African American participants (n=70) who discussed barriers and facilitators to AD research participation including lumbar puncture (LP) studies. The moderator and co-moderator independently reviewed transcripts, identified themes, and coded transcripts for analysis. Participants were predominately female (73%) with a mean age of 52y (range 21–86y). Concerns and attitudes were consistent across education, socioeconomic status, and gender. Mistrust was a fundamental reason for nonparticipation. Additional barriers included insufficient information dissemination in the African American community, inconvenience, and reputation of the researcher and research institution. Barriers to participation in AD biomarker studies were fear of the unknown and adverse effects. Altruism and relevance of research projects to the individual, family members, or the African American community facilitate participation. Increased participation results from relationships with the community that extend beyond immediate research interests, dissemination of research findings, and emphasis on relevance of proposed studies. Pervasive barriers impede African American participation in AD research but can be overcome through a sustained presence in the community. PMID:20711059

"We Don't Want to Talk about That": Overcoming Barriers to Rural Aging Research and Interventions on Sensitive Topics

ERIC Educational Resources Information Center

Zanjani, Faika; Rowles, Graham D.

2012-01-01

Geographical, economic, social and cultural barriers to accessing services in rural areas are widely reported. Less widely discussed are dilemmas posed by individual and community reluctance to address sensitive health issues. This article, focusing on the highly sensitive area of mental health, and employing a participatory action approach,…

Overcoming nursing barriers to intensive care unit early mobilisation: A quality improvement project.

PubMed

Hunter, Oluwatobi O; George, Elisabeth L; Ren, Dianxu; Morgan, Douglas; Rosenzweig, Margaret; Klinefelter Tuite, Patricia

2017-06-01

To increase adherence with intensive care unit mobility by developing and implementing a mobility training program that addresses nursing barriers to early mobilisation. An intensive care unit mobility training program was developed, implemented and evaluated with a pre-test, immediate post-test and eight-week post-test. Patient mobility was tracked before and after training. A ten bed cardiac intensive care unit. The training program's efficacy was measured by comparing pre-test, immediate post-test and 8-week post-test scores. Patient mobilisation rates before and after training were compared. Protocol compliance was measured in the post training group. Nursing knowledge increased from pre-test to immediate post-test (p<0.0001) and pre-test to 8-week post-test (p<0.0001). Mean test scores decreased by seven points from immediate post-test (80±12) to 8-week post-test (73±14). Fear significantly decreased from pre-test to immediate post-test (p=0.03), but not from pre-test to 8-week post-test (p=0.06) or immediate post-test to 8-week post-test (p=0.46). Post training patient mobility rates increased although not significantly (p=0.07). Post training protocol compliance was 78%. The project successfully increased adherence with intensive care unit mobility and indicates that a training program could improve adoption of early mobility. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exploring the barriers to and facilitators of implementing research into practice.

PubMed

Johnston, Bridget; Coole, Carol; Narayanasamy, Melanie; Feakes, Ruth; Whitworth, Gillian; Tyrell, Tracy; Hardy, Beth

2016-08-02

District and community nursing roles have changed rapidly in recent years. Community nurses are increasingly being tasked with carrying out multiple roles, which require them to put research into practice and use evidence-based tools and interventions. The implementation of interventions and tools needs to be developed from empirical research, requiring evidence, to be translated into practice. However, this process may be compromised or enhanced by a number of factors. This exploratory, descriptive qualitative study sought to identify barriers and facilitators to community nurses implementing research into practice. Four focus groups were conducted with registered community nurses and district nurses (n=22). Analysis identified four main themes: keeping up to date with evidence; using a clinical tool; education/training and implementation. Findings suggest that there are barriers at a personal, professional and organisational level. Strategies are suggested to overcome these obstacles.

Mechanisms and Barriers in Cancer Nanomedicine: Addressing Challenges, Looking for Solutions.

PubMed

Anchordoquy, Thomas J; Barenholz, Yechezkel; Boraschi, Diana; Chorny, Michael; Decuzzi, Paolo; Dobrovolskaia, Marina A; Farhangrazi, Z Shadi; Farrell, Dorothy; Gabizon, Alberto; Ghandehari, Hamidreza; Godin, Biana; La-Beck, Ninh M; Ljubimova, Julia; Moghimi, S Moein; Pagliaro, Len; Park, Ji-Ho; Peer, Dan; Ruoslahti, Erkki; Serkova, Natalie J; Simberg, Dmitri

2017-01-24

Remarkable progress has recently been made in the synthesis and characterization of engineered nanoparticles for imaging and treatment of cancers, resulting in several promising candidates in clinical trials. Despite these advances, clinical applications of nanoparticle-based therapeutic/imaging agents remain limited by biological, immunological, and translational barriers. In order to overcome the existing status quo in drug delivery, there is a need for open and frank discussion in the nanomedicine community on what is needed to make qualitative leaps toward translation. In this Nano Focus, we present the main discussion topics and conclusions from a recent workshop: "Mechanisms and Barriers in Nanomedicine". The focus of this informal meeting was on biological, toxicological, immunological, and translational aspects of nanomedicine and approaches to move the field forward productively. We believe that these topics reflect the most important issues in cancer nanomedicine.

Sustainable fuel, food, fertilizer and ecosystems through a global artificial photosynthetic system: overcoming anticompetitive barriers.

PubMed

Bruce, Alex; Faunce, Thomas

2015-06-06

This article discusses challenges that artificial photosynthetic (AP) systems will face when entering and competing in a global market characterized by established fossil fuel technology. It provides a perspective on the neoliberal principles underpinning much policy entrenching such environmentally destructive technology and outlines how competition law could aid overcoming these hurdles for AP development. In particular, it critiques the potential for competition law to promote a global AP initiative with greater emphasis on atmospheric carbon dioxide and nitrogen fixation (as well as solar-driven water splitting) to produce an equitable, globally distributed source of human food, fertilizer and biosphere sustainability, as well as hydrogen-based fuel. Some relevant strategies of competition law evaluated in this context include greater citizen-consumer involvement in shaping market values, legal requirements to factor services from the natural environment (i.e. provision of clean air, water, soil pollution degradation) into corporate costs, reform of corporate taxation and requirements to balance maximization of shareholder profit with contribution to a nominated public good, a global financial transactions tax, as well as prohibiting horizontal cartels, vertical agreements and unilateral misuse of market power.

Sustainable fuel, food, fertilizer and ecosystems through a global artificial photosynthetic system: overcoming anticompetitive barriers

PubMed Central

Bruce, Alex; Faunce, Thomas

2015-01-01

This article discusses challenges that artificial photosynthetic (AP) systems will face when entering and competing in a global market characterized by established fossil fuel technology. It provides a perspective on the neoliberal principles underpinning much policy entrenching such environmentally destructive technology and outlines how competition law could aid overcoming these hurdles for AP development. In particular, it critiques the potential for competition law to promote a global AP initiative with greater emphasis on atmospheric carbon dioxide and nitrogen fixation (as well as solar-driven water splitting) to produce an equitable, globally distributed source of human food, fertilizer and biosphere sustainability, as well as hydrogen-based fuel. Some relevant strategies of competition law evaluated in this context include greater citizen–consumer involvement in shaping market values, legal requirements to factor services from the natural environment (i.e. provision of clean air, water, soil pollution degradation) into corporate costs, reform of corporate taxation and requirements to balance maximization of shareholder profit with contribution to a nominated public good, a global financial transactions tax, as well as prohibiting horizontal cartels, vertical agreements and unilateral misuse of market power. PMID:26052427

Threshold concepts as barriers to understanding climate science

NASA Astrophysics Data System (ADS)

Walton, P.

2013-12-01

Whilst the scientific case for current climate change is compelling, the consequences of climate change have largely failed to permeate through to individuals. This lack of public awareness of the science and the potential impacts could be considered a key obstacle to action. The possible reasons for such limited success centre on the issue that climate change is a complex subject, and that a wide ranging academic, political and social research literature on the science and wider implications of climate change has failed to communicate the key issues in an accessible way. These failures to adequately communicate both the science and the social science of climate change at a number of levels results in ';communication gaps' that act as fundamental barriers to both understanding and engagement with the issue. Meyer and Land (2003) suggest that learners can find certain ideas and concepts within a discipline difficult to understand and these act as a barrier to deeper understanding of a subject. To move beyond these threshold concepts, they suggest that the expert needs to support the learner through a range of learning experiences that allows the development of learning strategies particular to the individual. Meyer and Land's research into these threshold concepts has been situated within Economics, but has been suggested to be more widely applicable though there has been no attempt to either define or evaluate threshold concepts to climate change science. By identifying whether common threshold concepts exist specifically in climate science for cohorts of either formal or informal learners, scientists will be better able to support the public in understanding these concepts by changing how the knowledge is communicated to help overcome these barriers to learning. This paper reports on the findings of a study that examined the role of threshold concepts as barriers to understanding climate science in a UK University and considers its implications for wider

Bridging the gap: exploring the barriers to using economic evidence in healthcare decision making and strategies for improving uptake.

PubMed

Merlo, Gregory; Page, Katie; Ratcliffe, Julie; Halton, Kate; Graves, Nicholas

2015-06-01

Evidence from economic evaluations is often not used to inform healthcare policy despite being well regarded by policy makers and physicians. This article employs the accessibility and acceptability framework to review the barriers to using evidence from economic evaluation in healthcare policy and the strategies used to overcome these barriers. Economic evaluations are often inaccessible to policymakers due to the absence of relevant economic evaluations, the time and cost required to conduct and interpret economic evaluations, and lack of expertise to evaluate quality and interpret results. Consistently reported factors that limit the translation of findings from economic evaluations into healthcare policy include poor quality of research informing economic evaluations, assumptions used in economic modelling, conflicts of interest, difficulties in transferring resources between sectors, negative attitudes to healthcare rationing, and the absence of equity considerations. Strategies to overcome these barriers have been suggested in the literature, including training, structured abstract databases, rapid evaluation, reporting checklists for journals, and considering factors other than cost effectiveness in economic evaluations, such as equity or budget impact. The factors that prevent or encourage decision makers to use evidence from economic evaluations have been identified, but the relative importance of these factors to decision makers is uncertain.

13C nuclear magnetic resonance data of lanosterol derivatives—Profiling the steric topology of the steroid skeleton via substituent effects on its 13C NMR

NASA Astrophysics Data System (ADS)

Dias, Jerry Ray; Gao, Hongwu

2009-12-01

The 13C NMR spectra of over 24 tetracyclic triterpenoid derivatives have been structurally analyzed. The 13C NMR chemical shifts allow one to probe the steric topology of the rigid steroid skeleton and inductive effects of its substituents. Use of deuterium labeling in chemical shift assignment and B-ring aromatic terpenoids are also featured.

Direct force measurements reveal that protein Tau confers short-range attractions and isoform-dependent steric stabilization to microtubules

PubMed Central

Chung, Peter J.; Choi, Myung Chul; Miller, Herbert P.; Feinstein, H. Eric; Raviv, Uri; Li, Youli; Wilson, Leslie; Feinstein, Stuart C.; Safinya, Cyrus R.

2015-01-01

Microtubules (MTs) are hollow cytoskeletal filaments assembled from αβ-tubulin heterodimers. Tau, an unstructured protein found in neuronal axons, binds to MTs and regulates their dynamics. Aberrant Tau behavior is associated with neurodegenerative dementias, including Alzheimer’s. Here, we report on a direct force measurement between paclitaxel-stabilized MTs coated with distinct Tau isoforms by synchrotron small-angle X-ray scattering (SAXS) of MT-Tau mixtures under osmotic pressure (P). In going from bare MTs to MTs with Tau coverage near the physiological submonolayer regime (Tau/tubulin-dimer molar ratio; ΦTau = 1/10), isoforms with longer N-terminal tails (NTTs) sterically stabilized MTs, preventing bundling up to PB ∼ 10,000–20,000 Pa, an order of magnitude larger than bare MTs. Tau with short NTTs showed little additional effect in suppressing the bundling pressure (PB ∼ 1,000–2,000 Pa) over the same range. Remarkably, the abrupt increase in PB observed for longer isoforms suggests a mushroom to brush transition occurring at 1/13 < ΦTau < 1/10, which corresponds to MT-bound Tau with NTTs that are considerably more extended than SAXS data for Tau in solution indicate. Modeling of Tau-mediated MT–MT interactions supports the hypothesis that longer NTTs transition to a polyelectrolyte brush at higher coverages. Higher pressures resulted in isoform-independent irreversible bundling because the polyampholytic nature of Tau leads to short-range attractions. These findings suggest an isoform-dependent biological role for regulation by Tau, with longer isoforms conferring MT steric stabilization against aggregation either with other biomacromolecules or into tight bundles, preventing loss of function in the crowded axon environment. PMID:26542680

Steric modifications tune the regioselectivity of the alkane oxidation catalyzed by non-heme iron complexes.

PubMed

He, Yu; Gorden, John D; Goldsmith, Christian R

2011-12-19

Iron complexes with the tetradentate N-donor ligand N,N'-di(phenylmethyl)-N,N'-bis(2-pyridinylmethyl)-1,2-cyclohexanediamine (bbpc) are reported. Despite the benzyl groups present on the amines, the iron compounds catalyze the oxygenation of cyclohexane to an extent similar to those employing less sterically encumbered ligands. The catalytic activity is strongly dependent on the counterion, with the highest activity and the strongest preference for alkane hydroxylation correlating to the most weakly coordinating anion, SbF(6)(-). The selectivity for the alcohol product over the ketone is amplified when acetic acid is present as an additive. When hydrocarbon substrates with both secondary and tertiary carbons are oxidized by H(2)O(2), the catalyst directs oxidation toward the secondary carbons to a greater degree than other previously reported iron-containing homogeneous catalysts. © 2011 American Chemical Society

Intracavity double diode structures with GaInP barrier layers for thermophotonic cooling

NASA Astrophysics Data System (ADS)

Tiira, Jonna; Radevici, Ivan; Haggren, Tuomas; Hakkarainen, Teemu; Kivisaari, Pyry; Lyytikäinen, Jari; Aho, Arto; Tukiainen, Antti; Guina, Mircea; Oksanen, Jani

2017-02-01

Optical cooling of semiconductors has recently been demonstrated both for optically pumped CdS nanobelts and for electrically injected GaInAsSb LEDs at very low powers. To enable cooling at larger power and to understand and overcome the main obstacles in optical cooling of conventional semiconductor structures, we study thermophotonic (TPX) heat transport in cavity coupled light emitters. Our structures consist of a double heterojunction (DHJ) LED with a GaAs active layer and a corresponding DHJ or a p-n-homojunction photodiode, enclosed within a single semiconductor cavity to eliminate the light extraction challenges. Our presently studied double diode structures (DDS) use GaInP barriers around the GaAs active layer instead of the AlGaAs barriers used in our previous structures. We characterize our updated double diode structures by four point probe IV- measurements and measure how the material modifications affect the recombination parameters and coupling quantum efficiencies in the structures. The coupling quantum efficiency of the new devices with InGaP barrier layers is found to be approximately 10 % larger than for the structures with AlGaAs barriers at the point of maximum efficiency.

Barriers to HIV Cure.

PubMed

Stein, J; Storcksdieck Genannt Bonsmann, M; Streeck, H

2016-10-01

Since the beginning of the epidemic, more than 70 million people have been infected with human immunodeficiency virus (HIV) and about 38 million have died from acquired immune deficiency syndrome (AIDS)-related illnesses. While the discovery of highly active antiretroviral therapy (HAART) in the mid 90's has saved millions of lives, a complete eradication of HIV is still not possible as HIV can persist for decades in a small reservoir of latently infected cells. Once reactivated, these latently infected cells can actively produce viral particles. Recent studies suggest that several sanctuaries exist within infected individuals where HIV can remain undetected by the immune system. These cellular, anatomical and microanatomical viral reservoirs represent a major obstacle for the eradication of HIV. Here we review recent findings on potential sanctuaries of HIV and address potential avenues to overcome these immunological barriers. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Conformational Analysis of Retinoic Acids: Effects of Steric Interactions on Nonplanar Conjugated Polyenes.

PubMed

Cox, Bryan D; Muccio, Donald D; Hamilton, Tracy P

2013-05-01

Retinoic acids and other vitamin A analogs contain a trimethylcyclohexenyl ring in conjugation with a polyene chain joined at carbon-6 (C6) and carbon-7 (C7). A MP2-SCS/cc-pVDZ// B3LYP/6-31G(d) 2-D potential energy surface was computed for all- trans retinoic acid, which had 6 minima (3 enantiomeric pairs). The global minima were distorted s-gauche enantiomers ( 6-7 = 53°) with half-chair conformations of the ring. Distorted s-gauche enantiomers ( 6-7 = 55°) with inverted half-chair ring conformations were 1.7 kJ/mol above the global minima. The s-trans enantiomers ( 6-7 = 164°) were 11.3 kJ/mol above the global minima. Steric energies were computed by the method of Guo and Karplus to identify key structural elements in retinoic acids which determines their conformation. Small molecule crystal structures in the CCDC database with trimethylcyclohexenyl ring and exocyclic double bonds have ring-chain geometries near to one of the 6 energy minima of retinoic acids, except for retinaldehyde iminium cations.

Steric hindrance and the enhanced stability of light rare-earth elements in hydrothermal fluids

USGS Publications Warehouse

Mayanovic, Robert A.; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming

2009-01-01

A series of X-ray absorption spectroscopy (XAS) experiments were made to determine the structure and stability of aqueous REE (La, Nd, Gd, and Yb) chloride complexes to 500 ??C and 520 MPa. The REE3+ ions exhibit inner-sphere chloroaqua complexation with a steady increase of chloride coordination with increasing temperature in the 150 to 500 ??C range. Furthermore, the degree of chloride coordination of REE3+ inner-sphere chloroaqua complexes decreases significantly from light to heavy REE. These results indicate that steric hindrance drives the reduction of chloride coordination of REE3+ inner-sphere chloroaqua complexes from light to heavy REE. This results in greater stability and preferential transport of light REE3+ over heavy REE3+ ions in saline hydrothermal fluids. Accordingly, the preferential mobility of light REE directly influences the relative abundance of REE in rocks and minerals and thus needs to be considered in geochemical modeling of petrogenetic and ore-forming processes affected by chloride-bearing hydrothermal fluids.

Unlocking the steric gate of DNA polymerase η leads to increased genomic instability in Saccharomyces cerevisiae

PubMed Central

Donigan, Katherine A.; Cerritelli, Susana M.; McDonald, John P.; Vaisman, Alexandra; Crouch, Robert J.; Woodgate, Roger

2015-01-01

DNA polymerase η (pol η) is best characterized for its ability to perform accurate and efficient translesion DNA synthesis (TLS) through cyclobutane pyrimidine dimers (CPDs). To ensure accurate bypass the polymerase is not only required to select the correct base, but also discriminate between NTPs and dNTPs. Most DNA polymerases have a conserved “steric gate” residue which functions to prevent incorporation of NMPs during DNA synthesis. Here, we demonstrate that the Phe35 residue of S. cerevisiae pol η functions as a steric gate to limit the use of ribonucleotides during polymerization both in vitro and in vivo. Unlike the related polι enzyme, wild-type pol η does not readily incorporate NMPs in vitro. In contrast, a pol η F35A mutant incorporates NMPs on both damaged and undamaged DNA in vitro with a high degree of base selectivity. An S. cerevisiae strain expressing pol η F35A (rad30-F35A) that is also deficient for nucleotide excision repair (rad1Δ) and the TLS polymerase, pol ζ (rev3Δ), is extremely sensitive to UV-light. The sensitivity is due, in part, to RNaseH2 activity, as an isogenic rnh201Δ strain is roughly 50-fold more UV-resistant than its RNH201+ counterpart. Interestingly the rad1Δ rev3Δ rad30-F35A rnh201Δ strain exhibits a significant increase in the extent of spontaneous mutagenesis with a spectrum dominated by 1 bp deletions at runs of template Ts. We hypothesize that the increased mutagenesis is due to rA incorporation at these sites and that the short poly rA tract is subsequently repaired in an error-prone manner by a novel repair pathway that is specifically targeted to polyribonucleotide tracks. These data indicate that under certain conditions, pol η can compete with the cell’s replicases and gain access to undamaged genomic DNA. Such observations are consistent with a role for pol η in replicating common fragile sites (CFS) in human cells. PMID:26340535

Unlocking the steric gate of DNA polymerase η leads to increased genomic instability in Saccharomyces cerevisiae.

PubMed

Donigan, Katherine A; Cerritelli, Susana M; McDonald, John P; Vaisman, Alexandra; Crouch, Robert J; Woodgate, Roger

2015-11-01

DNA polymerase η (pol η) is best characterized for its ability to perform accurate and efficient translesion DNA synthesis (TLS) through cyclobutane pyrimidine dimers (CPDs). To ensure accurate bypass the polymerase is not only required to select the correct base, but also discriminate between NTPs and dNTPs. Most DNA polymerases have a conserved "steric gate" residue which functions to prevent incorporation of NMPs during DNA synthesis. Here, we demonstrate that the Phe35 residue of Saccharomyces cerevisiae pol η functions as a steric gate to limit the use of ribonucleotides during polymerization both in vitro and in vivo. Unlike the related pol ι enzyme, wild-type pol η does not readily incorporate NMPs in vitro. In contrast, a pol η F35A mutant incorporates NMPs on both damaged and undamaged DNA in vitro with a high degree of base selectivity. An S.cerevisiae strain expressing pol η F35A (rad30-F35A) that is also deficient for nucleotide excision repair (rad1Δ) and the TLS polymerase, pol ζ (rev3Δ), is extremely sensitive to UV-light. The sensitivity is due, in part, to RNase H2 activity, as an isogenic rnh201Δ strain is roughly 50-fold more UV-resistant than its RNH201(+) counterpart. Interestingly the rad1Δ rev3Δ rad30-F35A rnh201Δ strain exhibits a significant increase in the extent of spontaneous mutagenesis with a spectrum dominated by 1bp deletions at runs of template Ts. We hypothesize that the increased mutagenesis is due to rA incorporation at these sites and that the short poly rA tract is subsequently repaired in an error-prone manner by a novel repair pathway that is specifically targeted to polyribonucleotide tracks. These data indicate that under certain conditions, pol η can compete with the cell's replicases and gain access to undamaged genomic DNA. Such observations are consistent with a role for pol η in replicating common fragile sites (CFS) in human cells. Published by Elsevier B.V.

An Action Research Study of Barriers to Differentiated Instruction in Reading for Georgia Middle School Students in the Inclusive Classroom

ERIC Educational Resources Information Center

Boston, Alicia

2017-01-01

The purpose of this qualitative action research study was to explore middle school inclusion teacher perceptions to overcome barriers to successful DI implementation in reading for students with special needs. Inclusion reading teachers are faced with the challenge of providing classroom instruction to students with varying abilities, levels, and…

Sterics level the rates of proton transfer to [Ni(XPh){PhP(CH₂CH₂PPh₂)₂}]⁺ (X = O, S or Se).

PubMed

Alwaaly, Ahmed; Henderson, Richard A

2014-09-04

Rates of proton transfers between lutH(+) (lut = 2,6-dimethylpyridine) and [Ni(XPh)(PhP{CH2CH2PPh2}2)](+) (X = O, S or Se) are slow and show little variation (k(O) : k(S) : k(Se) = 1 : 12 : 9). This unusual behaviour is a consequence of sterics affecting the optimal interaction between the reactants prior to proton transfer.

Breaking down patient and physician barriers to optimize glycemic control in type 2 diabetes.

PubMed

Ross, Stuart A

2013-09-01

Approximately half of patients with type 2 diabetes (T2D) do not achieve globally recognized blood glucose targets, despite the availability of a wide range of effective glucose-lowering therapies. Failure to maintain good glycemic control increases the risk of diabetes-related complications and long-term health care costs. Patients must be brought under glycemic control to improve treatment outcomes, but existing barriers to optimizing glycemic control must first be overcome, including patient nonadherence to treatment, the failure of physicians to intensify therapy in a timely manner, and inadequacies in the health care system itself. The reasons for such barriers include treatment side effects, complex treatment regimens, needle anxiety, poor patient education, and the absence of an adequate patient care plan; however, newer therapies and devices, combined with comprehensive care plans involving adequate patient education, can help to minimize barriers and improve treatment outcomes. Copyright © 2013 Elsevier Inc. All rights reserved.

Predicting performance and performance satisfaction: mindfulness and beliefs about the ability to deal with social barriers in sport.

PubMed

Blecharz, Jan; Luszczynska, Aleksandra; Scholz, Urte; Schwarzer, Ralf; Siekanska, Malgorzata; Cieslak, Roman

2014-05-01

This research investigates the role of beliefs about the ability to deal with specific social barriers and its relationships to mindfulness, football performance, and satisfaction with one's own and team performance. Study 1 aimed at eliciting these social barriers. Study 2 tested (i) whether self-efficacy referring to social barriers would predict performance over and above task-related self-efficacy and collective efficacy and (ii) the mediating role of self-efficacy to overcome social barriers in the relationship between mindfulness and performance. Participants were football (soccer) players aged 16-21 years (Study 1: N=30; Study 2: N=101, longitudinal sample: n=88). Study 1 resulted in eliciting 82 social barriers referring to team, peer leadership, and coaches. Study 2 showed that task-related self-efficacy and collective efficacy explained performance satisfaction at seven-month follow-up, whereas self-efficacy referring to social barriers explained shooting performance at seven-month follow-up. Indirect associations between mindfulness and performance were found with three types of self-efficacy referring to social barriers, operating as parallel mediators. Results provide evidence for the role of beliefs about the ability to cope with social barriers and show a complex interplay between different types of self-efficacy and collective efficacy in predicting team sport performance.

Perceived barriers to healthy eating and physical activity among adolescents in seven Arab countries: a cross-cultural study.

PubMed

Musaiger, Abdulrahman O; Al-Mannai, Mariam; Tayyem, Reema; Al-Lalla, Osama; Ali, Essa Y A; Kalam, Faiza; Benhamed, Mofida M; Saghir, Sabri; Halahleh, Ismail; Djoudi, Zahra; Chirane, Manel

2013-01-01

To highlight the perceived personal, social, and environmental barriers to healthy eating and physical activity among Arab adolescents. A multistage stratified sampling method was used to select 4698 students aged 15-18 years (2240 males and 2458 females) from public schools. Seven Arab counties were included in the study, namely, Algeria, Jordan, Kuwait, Libya, Palestine, Syria, and the United Arab Emirates. Self-reported questionnaire was used to list the barriers to healthy eating and physical activity facing these adolescents. It was found that lack of information on healthy eating, lack of motivation to eat a healthy diet, and not having time to prepare or eat healthy food were the main barriers to healthy eating among both genders. For physical activity, the main barriers selected were lack of motivation to do physical activity, less support from teachers, and lack of time to do physical activity. In general, females faced more barriers to physical activity than males in all countries included. There were significant differences between males and females within each country and among countries for most barriers. Intervention programmes to combat obesity and other chronic noncommunicable diseases in the Arab world should include solutions to overcome the barriers to weight maintenance, particularly the sociocultural barriers to practising physical activity.

Perceived Barriers to Healthy Eating and Physical Activity among Adolescents in Seven Arab Countries: A Cross-Cultural Study

PubMed Central

Musaiger, Abdulrahman O.; Tayyem, Reema; Al-Lalla, Osama; Ali, Essa Y. A.; Kalam, Faiza; Benhamed, Mofida M.; Saghir, Sabri; Halahleh, Ismail; Djoudi, Zahra; Chirane, Manel

2013-01-01

Objective. To highlight the perceived personal, social, and environmental barriers to healthy eating and physical activity among Arab adolescents. Method. A multistage stratified sampling method was used to select 4698 students aged 15–18 years (2240 males and 2458 females) from public schools. Seven Arab counties were included in the study, namely, Algeria, Jordan, Kuwait, Libya, Palestine, Syria, and the United Arab Emirates. Self-reported questionnaire was used to list the barriers to healthy eating and physical activity facing these adolescents. Results. It was found that lack of information on healthy eating, lack of motivation to eat a healthy diet, and not having time to prepare or eat healthy food were the main barriers to healthy eating among both genders. For physical activity, the main barriers selected were lack of motivation to do physical activity, less support from teachers, and lack of time to do physical activity. In general, females faced more barriers to physical activity than males in all countries included. There were significant differences between males and females within each country and among countries for most barriers. Conclusion. Intervention programmes to combat obesity and other chronic noncommunicable diseases in the Arab world should include solutions to overcome the barriers to weight maintenance, particularly the sociocultural barriers to practising physical activity. PMID:24348144

Human immunodeficiency virus-associated disruption of mucosal barriers and its role in HIV transmission and pathogenesis of HIV/AIDS disease

PubMed Central

Tugizov, Sharof

2016-01-01

Abstract Oral, intestinal and genital mucosal epithelia have a barrier function to prevent paracellular penetration by viral, bacterial and other pathogens, including human immunodeficiency virus (HIV). HIV can overcome these barriers by disrupting the tight and adherens junctions of mucosal epithelia. HIV-associated disruption of epithelial junctions may also facilitate paracellular penetration and dissemination of other viral pathogens. This review focuses on possible molecular mechanisms of HIV-associated disruption of mucosal epithelial junctions and its role in HIV transmission and pathogenesis of HIV and acquired immune deficiency syndrome (AIDS). PMID:27583187

Learning from failure in health care: frequent opportunities, pervasive barriers.

PubMed

Edmondson, A C

2004-12-01

The notion that hospitals and medical practices should learn from failures, both their own and others', has obvious appeal. Yet, healthcare organisations that systematically and effectively learn from the failures that occur in the care delivery process, especially from small mistakes and problems rather than from consequential adverse events, are rare. This article explores pervasive barriers embedded in healthcare's organisational systems that make shared or organisational learning from failure difficult and then recommends strategies for overcoming these barriers to learning from failure, emphasising the critical role of leadership. Firstly, leaders must create a compelling vision that motivates and communicates urgency for change; secondly, leaders must work to create an environment of psychological safety that fosters open reporting, active questioning, and frequent sharing of insights and concerns; and thirdly, case study research on one hospital's organisational learning initiative suggests that leaders can empower and support team learning throughout their organisations as a way of identifying, analysing, and removing hazards that threaten patient safety.

Learning from failure in health care: frequent opportunities, pervasive barriers

PubMed Central

Edmondson, A

2004-01-01

The notion that hospitals and medical practices should learn from failures, both their own and others', has obvious appeal. Yet, healthcare organisations that systematically and effectively learn from the failures that occur in the care delivery process, especially from small mistakes and problems rather than from consequential adverse events, are rare. This article explores pervasive barriers embedded in healthcare's organisational systems that make shared or organisational learning from failure difficult and then recommends strategies for overcoming these barriers to learning from failure, emphasising the critical role of leadership. Firstly, leaders must create a compelling vision that motivates and communicates urgency for change; secondly, leaders must work to create an environment of psychological safety that fosters open reporting, active questioning, and frequent sharing of insights and concerns; and thirdly, case study research on one hospital's organisational learning initiative suggests that leaders can empower and support team learning throughout their organisations as a way of identifying, analysing, and removing hazards that threaten patient safety. PMID:15576689

Overcoming Learning Barriers through Knowledge Management

ERIC Educational Resources Information Center

Dror, Itiel E.; Makany, Tamas; Kemp, Jonathan

2011-01-01

The ability to learn highly depends on how knowledge is managed. Specifically, different techniques for note-taking utilize different cognitive processes and strategies. In this paper, we compared dyslexic and control participants when using linear and non-linear note-taking. All our participants were professionals working in the banking and…

Overcoming Barriers to Classroom Technology Integration

ERIC Educational Resources Information Center

Kelly, Daniel P.

2015-01-01

Technology-savvy teachers are often the "go to" staff members in schools for their colleagues' technology issues. These teachers are seen as leaders within their schools with respect to technology and often do not understand their peers' difficulties when bringing technology into the classroom. Understanding both the reasons teachers may…

Overcoming the Cutaneous Barrier with Microemulsions

PubMed Central

Lopes, Luciana B.

2014-01-01

Microemulsions are fluid and isotropic formulations that have been widely studied as delivery systems for a variety of routes, including the skin. In spite of what the name suggests, microemulsions are nanocarriers, and their use as topical delivery systems derives from their multiple advantages compared to other dermatological formulations, such as ease of preparation, thermodynamic stability and penetration-enhancing properties. Composition, charge and internal structure have been reported as determinant factors for the modulation of drug release and cutaneous and transdermal transport. This manuscript aims at reviewing how these and other characteristics affect delivery and make microemulsions appealing for topical and transdermal administration, as well as how they can be modulated during the formulation design to improve the potential and efficacy of the final system. PMID:24590260

Financing and systems barriers to seasonal influenza vaccine delivery in community settings.