A mathematical model of venous neointimal hyperplasia formation

<p>Abstract</p> <p>Background</p> <p>In hemodialysis patients, the most common cause of vascular access failure is neointimal hyperplasia of vascular smooth muscle cells at the venous anastomosis of arteriovenous fistulas and grafts. The release of growth factors due to surgical injury, oxidative stress and turbulent flow has been suggested as a possible mechanism for neointimal hyperplasia.</p> <p>Results</p> <p>In this work, we construct a mathematical model which analyzes the role that growth factors might play in the stenosis at the venous anastomosis. The model consists of a system of partial differential equations describing the influence of oxidative stress and turbulent flow on growth factors, the interaction among growth factors, smooth muscle cells, and extracellular matrix, and the subsequent effect on the stenosis at the venous anastomosis, which, in turn, affects the level of oxidative stress and degree of turbulent flow. Computer simulations suggest that our model can be used to predict access stenosis as a function of the initial concentration of the growth factors inside the intimal-luminal space.</p> <p>Conclusion</p> <p>The proposed model describes the formation of venous neointimal hyperplasia, based on pathogenic mechanisms. The results suggest that interventions aimed at specific growth factors may be successful in prolonging the life of the vascular access, while reducing the costs of vascular access maintenance. The model may also provide indication of when invasive access surveillance to repair stenosis should be undertaken.</p

OPTIMASI SINTESIS ASAM AZELAT DARI ASAM OLEAT DAN HIDROGEN PEROKSIDA MENGGUNAKAN KATALIS ASAM TUNGSTAT

Azealic acid is an oleochemical product which is an output from oleic acid with oxidation cleavage process and commonly its aplication in polymer industry such as nylon production, plastic industry, glue industry and also as fiber in polyester industry. The purpose of this research is to obtain comparison design and analysis of variance in two method of synthesis azelaic acid namely one step and two steps oxidation. The result design reviewed by Response Surface Methodology using Minitab 17 trial version program with percent mass of the catalyst variable, molar ratio of the substrate variable and temperature variable. Based on the statistic analysis the percentage conversion&nbsp;(Y)in one step&nbsp;Y&nbsp;:&nbsp;97,99 + 3,907X1&nbsp;+ 3,651X2&nbsp;– 4,556X3&nbsp;– 1,467X12&nbsp;– 4,299X22&nbsp;– 4,453X32&nbsp;+ 0,57X1X2&nbsp;+ 0,63X1X3&nbsp;+ 1,37X2X3&nbsp;and for two steps&nbsp;Y&nbsp;:&nbsp;98,505 + 6,164X2&nbsp;+ 2,164X3-7,83X22-5,18X32. The design has R2&nbsp;= 92,80 % for one step&nbsp;and&nbsp;89,95 % in two steps

Community perceptions matter: a mixed-methods study using local knowledge to define features of success for a community intervention to improve quality of care for children under-5 in Jigawa, Nigeria

Objectives In this study, we used the information generated by community members during an intervention design process to understand the features needed for a successful community participatory intervention to improve child health. Design We conducted a concurrent mixed-methods study (November 2019–March 2020) to inform the design and evaluation of a community–facility linkage participatory intervention. Setting Kiyawa Local Government Area (Jigawa State, Nigeria)—population of 230 000 (n=425 villages). Participants Qualitative data included 12 community conversations with caregivers of children under-5 (men, older and younger women; n=9 per group), 3 focus group discussions (n=10) with ward development committee members and interviews with facility heads (n=3). Quantitative data comprised household surveys (n=3464) with compound heads (n=1803) and women (n=1661). Results We analysed qualitative data with thematic network analysis and the surveys with linear regression—results were triangulated in the interpretation phase. Participants identified the following areas of focus: community health education; facility infrastructure, equipment and staff improvements; raising funds to make these changes. Community involvement, cooperation and empowerment were recognised as a strategy to improve child health, and the presence of intermediate bodies (development committees) was deemed important to improve communication and solve problems between community and facility members. The survey showed functional community relations’ dynamics, with high levels of internal cohesion (78%), efficacy in solving problems together (79%) and fairness of the local leaders (82%). Conclusions Combining the results from this study and critical theories on successful participation identified community-informed features for a contextually tailored community–facility link intervention. The need to promote a more inclusive approach to future child health interventions was highlighted. In addition to health education campaigns, the relationship between community and healthcare providers needs strengthening, and development committees were identified as an essential feature for successfully linking communities and facilities for child health. Trial registration number ISRCTN39213655

Gene products and processes contributing to lanthanide homeostasis and methanol metabolism in \u3cem\u3eMethylorubrum extorquens\u3c/em\u3e AM1

Lanthanide elements have been recently recognized as “new life metals” yet much remains unknown regarding lanthanide acquisition and homeostasis. In Methylorubrum extorquens AM1, the periplasmic lanthanide-dependent methanol dehydrogenase XoxF1 produces formaldehyde, which is lethal if allowed to accumulate. This property enabled a transposon mutagenesis study and growth studies to confirm novel gene products required for XoxF1 function. The identified genes encode an MxaD homolog, an ABC-type transporter, an aminopeptidase, a putative homospermidine synthase, and two genes of unknown function annotated as orf6 and orf7. Lanthanide transport and trafficking genes were also identified. Growth and lanthanide uptake were measured using strains lacking individual lanthanide transport cluster genes, and transmission electron microscopy was used to visualize lanthanide localization. We corroborated previous reports that a TonB-ABC transport system is required for lanthanide incorporation to the cytoplasm. However, cells were able to acclimate over time and bypass the requirement for the TonB outer membrane transporter to allow expression of xoxF1 and growth. Transcriptional reporter fusions show that excess lanthanides repress the gene encoding the TonB-receptor. Using growth studies along with energy dispersive X-ray spectroscopy and transmission electron microscopy, we demonstrate that lanthanides are stored as cytoplasmic inclusions that resemble polyphosphate granules

Prospectus, December 9, 1991

https://spark.parkland.edu/prospectus_1991/1018/thumbnail.jp

Pulse oximetry and oxygen services for the care of children with pneumonia attending frontline health facilities in Lagos, Nigeria (INSPIRING-Lagos): study protocol for a mixed-methods evaluation

INTRODUCTION: The aim of this evaluation is to understand whether introducing stabilisation rooms equipped with pulse oximetry and oxygen systems to frontline health facilities in Ikorodu, Lagos State, alongside healthcare worker (HCW) training improves the quality of care for children with pneumonia aged 0-59 months. We will explore to what extent, how, for whom and in what contexts the intervention works. METHODS AND ANALYSIS: Quasi-experimental time-series impact evaluation with embedded mixed-methods process and economic evaluation. SETTING: seven government primary care facilities, seven private health facilities, two government secondary care facilities. TARGET POPULATION: children aged 0-59 months with clinically diagnosed pneumonia and/or suspected or confirmed COVID-19. INTERVENTION: 'stabilisation rooms' within participating primary care facilities in Ikorodu local government area, designed to allow for short-term oxygen delivery for children with hypoxaemia prior to transfer to hospital, alongside HCW training on integrated management of childhood illness, pulse oximetry and oxygen therapy, immunisation and nutrition. Secondary facilities will also receive training and equipment for oxygen and pulse oximetry to ensure minimum standard of care is available for referred children. PRIMARY OUTCOME: correct management of hypoxaemic pneumonia including administration of oxygen therapy, referral and presentation to hospital. SECONDARY OUTCOME: 14-day pneumonia case fatality rate. Evaluation period: August 2020 to September 2022. ETHICS AND DISSEMINATION: Ethical approval from University of Ibadan, Lagos State and University College London. Ongoing engagement with government and other key stakeholders during the project. Local dissemination events will be held with the State Ministry of Health at the end of the project (December 2022). We will publish the main impact results, process evaluation and economic evaluation results as open-access academic publications in international journals. TRIAL REGISTRATION NUMBER: ACTRN12621001071819; Registered on the Australian and New Zealand Clinical Trials Registry

Integrated Sustainable childhood Pneumonia and Infectious disease Reduction in Nigeria (INSPIRING) through whole system strengthening in Jigawa, Nigeria: study protocol for a cluster randomised controlled trial

BACKGROUND: Child mortality remains unacceptably high, with Northern Nigeria reporting some of the highest rates globally (e.g. 192/1000 live births in Jigawa State). Coverage of key protect and prevent interventions, such as vaccination and clean cooking fuel use, is low. Additionally, knowledge, care-seeking and health system factors are poor. Therefore, a whole systems approach is needed for sustainable reductions in child mortality. METHODS: This is a cluster randomised controlled trial, with integrated process and economic evaluations, conducted from January 2021 to September 2022. The trial will be conducted in Kiyawa Local Government Area, Jigawa State, Nigeria, with an estimated population of 230,000. Clusters are defined as primary government health facility catchment areas (n = 33). The 33 clusters will be randomly allocated (1:1) in a public ceremony, and 32 clusters included in the impact evaluation. The trial will evaluate a locally adapted 'whole systems strengthening' package of three evidence-based methods: community men's and women's groups, Partnership Defined Quality Scorecard and healthcare worker training, mentorship and provision of basic essential equipment and commodities. The primary outcome is mortality of children aged 7 days to 59 months. Mortality will be recorded prospectively using a cohort design, and secondary outcomes measured through baseline and endline cross-sectional surveys. Assuming the following, we will have a minimum detectable effect size of 30%: (a) baseline mortality of 100 per 1000 livebirths, (b) 4480 compounds with 3 eligible children per compound, (c) 80% power, (d) 5% significance, (e) intra-cluster correlation of 0.007 and (f) coefficient of variance of cluster size of 0.74. Analysis will be by intention-to-treat, comparing intervention and control clusters, adjusting for compound and trial clustering. DISCUSSION: This study will provide robust evidence of the effectiveness and cost-effectiveness of community-based participatory learning and action, with integrated health system strengthening and accountability mechanisms, to reduce child mortality. The ethnographic process evaluation will allow for a rich understanding of how the intervention works in this context. However, we encountered a key challenge in calculating the sample size, given the lack of timely and reliable mortality data and the uncertain impacts of the COVID-19 pandemic. TRIAL REGISTRATION: ISRCTN 39213655 . Registered on 11 December 2019