bluuebunny/crossref_metadata_2025_split huggingface dataset:
19 mm Sized Bileaflet Valve Prostheses’ flow Field Investigated by Bidimensional Laser Doppler Anemometry (part II: Maximum Turbulent Shear Stresses)
Authors: Barbaro V. , Grigioni M. , Daniele C. , D'avenio G. , Boccanera G. 
Published: March 2018

The investigation of the flow field generated by cardiac valve prostheses is a necessary task to gain knowledge on the possible relationship between turbulence-derived stresses and the hemolytic and thrombogenic complications in patients after valve replacement. The study of turbulence flows downstream of cardiac prostheses, in literature, especially concerns large-sized prostheses with a variable flow regime from very low up to 6 L/min. The Food and Drug Administration draft guidance requires the study of the minimum prosthetic size at a high cardiac output to reach the maximum Reynolds number conditions. Within the framework of a national research project regarding the characterization of cardiovascular endoprostheses, an in-depth study of turbulence generated downstream of bileaflet cardiac valves is currently under way at the Laboratory of Biomedical Engineering of the Istituto Superiore di Sanità. Four models of 19 mm bileaflet valve prostheses were used: St Jude Medical HP, Edwards Tekna, Sorin Bicarbon, and CarboMedics. The prostheses were selected for the nominal Tissue Annulus Diameter as reported by manufacturers without any assessment of valve sizing method, and were mounted in aortic position. The aortic geometry was scaled for 19 mm prostheses using angiographic data. The turbulence-derived shear stresses were investigated very close to the valve (0.35 D0), using a bidimensional Laser Doppler anemometry system and applying the Principal Stress Analysis. Results concern typical turbulence quantities during a 50 ms window at peak flow in the systolic phase. Conclusions are drawn regarding the turbulence associated to valve design features, as well as the possible damage to blood constituents.
An Algorithm for the Rational Choice of Sodium Profile during Hemodialysis
Authors: Ursino M. , Colì L. , Dalmastri V. , Volpe F. , La Manna G. , Avanzouni G. , Stefoni S. , Bonomini V. 
Published: March 2018

The incidence of intradialytic disequilibrium syndrome and symptomatic hypotension has increased significantly among dialysis patients over the last ten years. Profiled hemodialysis (PHD) is a new technique, based on the intradialytic modulation of dialysate sodium concentration, which aspires to reduce to previous imbalances. This paper presents a new algorithm for the determination of a rational dialysate sodium profile during PHD. A mathematical model of solute kinetics, monocompartmental for sodium and bicompartmental for urea is used. The algorithm allows the sodium profile to be elaborated a priori before each dialysis session, respecting the individual sodium mass removal and weight gain. A procedure allowing the adjustment of the method to the individual characteristics, on the basis of routine measurements performed before each session is also presented. The method was validated during seven dialysis sessions. Comparison between data measured in vivo and those predicted by the model showed standard deviations corresponding to the range of laboratory measurement errors: 1.50 mEq/L for sodium and 0.87 mmol/L for urea. In vivo implementation of PHD by our algorithm allows one to remove an amount of sodium close to that established a priori on the basis of patient's need.
Pathophysiological Considerations concerning Uni- and Biventricular Mechanical Cardiac Assist
Authors: Waldenberger F.R. 
Published: March 2018

Mechanical assisted circulation by the means of cardiac assist devices is a routine procedure in modern cardiac surgery and cardiology. We investigated the impact of mechanical unloading on regional myocardial “stunning” and the influence of assisted circulation on left heart and right heart failure persevered by an ultimate addition of pulmonary hypertension in experimental set ups. We found that mechanical unloading either during ischemia or in the early reperfusion phase attenuates stunning and enhances the return of synchronous heart performance. In our global dysfunction model we showed that the right heart is dispensable. Sufficient inflow to the left heart is provided unless pulmonary hypertension is present. Also additional left heart support can not overcome the deleterious situation and in select cases only additional right heart support can prevent the “low LVAD output” syndrome. We conclude that mechanical assisted circulation and mechanical unloading are beneficial in case of regional and global dysfunction persevered by pulmonary hypertension, however, the knowledge about interactions of assist systems and the circulation has to be improved in order to optimize clinical assist device performance.
Measurement of the Upper Limit of Vulnerability during Defibrillator Implantation can Substitute Defibrillation Threshold Measurement
Authors: Bessho R. , Tanaka S. 
Published: March 2018

We investigated whether defibrillation thresholds (DFTs) could be measured more safely during defibrillator implantation by measuring the upper limit of vulnerability (ULV) without using any special equipment. Nonthoracotomy ICD implantation with endocardial leads was performed in 13 patients, and through the use of the ICD function itself, ULV and DFT were measured using the delayed four-episode up-down algorithm. Myocardial injures caused by high-energy current were assessed by electrocardiograms and serial CPK-MB. ULV was confirmed in all cases, and it strongly correlated with DFT. The average ULV was 5.9 ± 3.3J, while the average DFT was 7.9 ± 4.3J (r = 0.89, p < 0.0001, DFT = 1.20+1.14x ULV). The average ULV was thus significantly lower (p < 0.01). Although six patients were on amiodarone therapy, the strong correlation between ULV and DFT was also maintained (r = 0,97), p < 0.01) in these patients. In all cases, the CPK-MB failed to increase, and no myocardial injuries were detectable on electrocardiograms. We confirmed that ULV could be easily and safety measured during ICD implantation, and that ULV could be used instead of DFT.
Exhaustion of Vascular Endowment in Hemodialysis: Proposal for a Permanent Inlet Access
Authors: Bellinghieri G. , Ricciardi B. , Costantino G. , Torre F. , Santoro D. , Cimadoro D. , Savica V. 
Published: March 2018

The subcutaneous reservoir is a new vascular access for patients on regular hemodialysis (HD). A double chamber in Titanium- Pirolytic Carbon with siliconic boreable superior caps is inserted in to a subcutaneous subclavian side, and always in subcutis connected to two siliconic catheters located in the right jugular resulting in the right atrium. The puncture of each chamber is performed with a special hemodialysis-cannula telescopically assembled on a “dilatation tube”, in which a stylet is inserted. In correct sequence, the cutaneous planes and the caps are bored, dilated, and finally the HD cannula after sliding over the previous structures is positioned in the inner chamber, closing the HD circuit. In our study two patients were implanted, with a survival of 24 months, good compliance, no cardiovascular impairments and lack of catheteral pathology.
Salvage and Reinfusion of Chyle in Closed Chest Injury
Authors: Montebugnoli M. , Borghi B. , Bugamelli B. , Righi U. , Boaron D.M. , Valbonesi M. , Baroncini S. 
Published: March 2018

The aim of this study was to describe a system of salvaging and reinfusing chyle which accumulated in the right pleural cavity of a patient after a thoracic duct lesion caused by a closed chest injury associated with amyelic fracture of the dorsal spine D10-D11. The chyle was collected in a reservoir (BT 844 Dideco), transfered by an electronic pump (BT 797 recovery Dideco) to a storage bag, microfiltered and then reinfused to the patient. A solution was needed to prevent the patient with severe chylothorax, from having immunological and metabolic imbalance. The long period of conservative treatment with our system was imposed by the onset of acute post-traumatic myocardic infarction which delayed surgery. From experience gained, we can say that using total parenteral nutrition, chyle can not only be salvaged but also reinfused, respecting the strict rules of hygiene.
Grim FATE: Learning About Systems Thinking in an In-Depth Climate Change Simulation
Authors: Waddington David I. , Fennewald Thomas 
Published: March 2018

Background. Simulations of complex systems have a long history of use for the study and promotion of systems thinking, yet more can be done in identifying games that promote development of systems thinking. Aim. This study is an exploration of the hypothesis that FATE OF THE WORLD, a challenging and complex climate change simulation, can promote systems thinking about climate change. Questions. This article analyzes players’ engagement with FATE OF THE WORLD using three key questions: 1. In what ways does the game support thinking about climate change as a complex system? 2. Does the game correspond to players’ a priori model of climate change? 3. How do players relate to FATE as an artifact they embrace, critique, and tinker with? Method. 33 participants were matched into control and test groups, and experimental participants were assigned to play a full game scenario of FATE OF THE WORLD. Experimental and control groups were compared using pre-and-post intervention concept maps. Post interviews were conducted with the test group. Results.Concept maps revealed statistically significant differences between the control and test groups. Interviews revealed diversity in learning outcomes and the ways in which acceptance of the game’s model of climate change influenced learning. Conclusions. FATE serves as proof-of-concept for the power of complex simulations to promote systems thinking as well as in-depth reflection on key social challenges. However, simulations like FATE are unlikely to serve well as stand-alone educational tools, which highlights the importance of effective teaching to accompany the game.
A Systematic Review of Placental Biomarkers Predicting Small-for-Gestational-Age Neonates
Authors: Ruchob Rungnapa , Rutherford Julienne N. , Bell Aleeca F. 
Published: March 2018

Background: Neonates born small for gestational age (SGA) face increased risk of neonatal mortality, childhood developmental problems, and adult disease. The placenta is a key factor in SGA development because of its multiple biological processes that underlie fetal growth. However, valid and reliable placental biomarkers of SGA have not been determined. Objectives: The objective of this article was to systematically identify and review studies examining associations between placental biomarkers and SGA and assess those biomarkers’ predictive value. Methods: Use of the matrix method and the PRISMA guidelines ensured systematic identification of relevant articles based on selection criteria. PubMed, CINAHL, and EMBASE were searched for English articles published in 2005–2016 that addressed relationships between placental biomarkers and SGA. Results: The search captured 466 articles; 13 met selection criteria. The review identified 14 potential placental biomarkers for SGA, with placental growth factor and soluble fms-like tyrosine kinase 1 being the most commonly studied. However, findings for these and other biomarkers have often been contradictory. Thus, no placental biomarkers have been confirmed as reliable for predicting SGA. Conclusion: The inconsistent findings suggest low placental biomarker reliability, perhaps due to the multifactorial nature of SGA. This review is novel in its focus on identifying potential placental biomarkers for SGA, producing a better understanding of how placental function underlies fetal growth. Nevertheless, use of placental biomarkers alone may not be adequate for predicting SGA. Therefore, combinations of biomarkers and other predictive tests should be evaluated for their ability to predict risk of SGA.
Effect of arteriovenous graft flow rate on vascular access hemodynamics in a novel modular anastomotic valve device
Authors: McNally Andrew , Akingba A George , Sucosky Philippe 
Published: March 2018

Purpose: Perturbed vascular access hemodynamics is considered a potential driver of intimal hyperplasia, the leading cause of vascular access failure. To improve vascular access patency, a modular anastomotic valve device has been designed to normalize venous flow between hemodialysis periods while providing normal vascular access during hemodialysis. The objective of this study was to quantify the effects of arteriovenous graft flow rate on modular anastomotic valve device vascular access hemodynamics under realistic hemodialysis conditions. Methods: Modular anastomotic valve device inlet and outlet flow conditions and velocity profiles were measured by ultrasound Doppler in a vascular access flow loop replicating arteriovenous graft flow rates of 800, 1000, and 1500 mL/min. Fluid–structure interaction simulations were performed to identify low wall shear stress regions on the vein wall and to characterize them in terms of temporal shear magnitude, oscillatory shear index, and relative residence time. The model was validated with respect to the Doppler measurements. Results: The low wall shear stress region generated downstream of the anastomosis under low and moderate arteriovenous graft flow rates was eliminated under the highest arteriovenous graft flow rate. Increase in arteriovenous graft flow rate from 800 to 1500 mL/min resulted in a substantial increase in wall shear stress magnitude (27-fold increase in temporal shear magnitude), the elimination of wall shear stress bidirectionality (0.20-point reduction in oscillatory shear index), and a reduction in flow stagnation (98% decrease in relative residence time). While the results suggest the ability of high arteriovenous graft flow rates to protect the venous wall from intimal hyperplasia–prone hemodynamics, they indicate their adverse impact on the degree of venous hemodynamic abnormality.
Using an Assessment Tool to Further Tobacco Control Accomplishment in Thailand
Authors: Charoenca Naowarut , Kungskulniti Nipapun , Sritabutra Duangkamon , Pitayarangsarit Siriwan , Hamann Stephen L 
Published: March 2018

Background: Because implementation of the Framework Convention on Tobacco Control (FCTC), a World Health Organization (WHO) treaty to reduce tobacco use, is an important goal of the 2015 United Nations Sustainable Development Goals (SDGs) and Thailand has sought to fully comply with all its articles, a multiperspective assessment was developed to ensure that any gaps in compliance with FCTC provisions were identified and addressed. Method: One assessment mechanism of this multicomponent assessment was the development by experts and use by stakeholders of a 3-tiered rating of all major provisions of the main articles of the FCTC. The results of the performance ratings on FCTC articles by a diverse group of stakeholders were used to spotlight areas of local and regional implementation and compliance with FCTC provisions. Results: Implementation ratings by stakeholders generally followed the chronology of WHO priorities as reflected in the development by WHO of guidelines for the various FCTC articles with highest ratings for articles 6, 8, 11, 12, 14, 15, and 16. However, only 5 articles (Articles 6, 11, 12, 15, and 16) reached level 2 (effectiveness) of the 3-level rating; articles 6, 8, 11, 13, and 14 are discussed because they are the WHO priority articles of the MPOWER tobacco control policy. Importantly, stakeholders cited problems with lack of completeness of present Thai law and processes for enforcement, as well as lack of public understanding regarding tobacco control strategies and provisions. Conclusions: Overall, the breadth and inclusiveness of the stakeholder approach devised for improving implementation by the Tobacco Control Research and Knowledge Management Center provided greater understanding about shortcomings of present policy and resource management which informed the Tobacco Products Control Act passed in 2017 and plans for advancing stronger Thai regulation by local and national government.
Further Delineation of the Clinical Phenotype of Cerebellar Ataxia, Mental Retardation, and Disequilibrium Syndrome Type 4
Authors: Alsahli Saud , Alrifai Muhammad Talal , Al Tala Saeed , Mutairi Fuad Al , Alfadhel Majid 
Published: March 2018

Background: Cerebellar ataxia, mental retardation, and disequilibrium syndrome (CAMRQ) is a heterogeneous group of genetic disorders that have been grouped by shared clinical features; all of these features are transmitted via an autosomal recessive mechanism. Four variants of this syndrome have been identified so far, and each one differs in terms of both clinical and genotypical features. CAMRQ4 is a rare genetic disorder characterized by mental retardation, ataxia or an inability to walk, dysarthria and, in some patients, quadrupedal gait. Methods: We investigated three Saudi families with CAMRQ4. Blood samples were collected from the affected patients, their parents, and healthy siblings. DNA was extracted from whole blood, and whole-exome sequencing was performed. Findings were confirmed by segregation analysis, which was performed on other family members. Results: Thus far, 17 patients have been affected by CAMRQ4. Genetic analysis of all patients, including our current patients, showed a mutation in the aminophospholipid transporter, class I, type 8A, member 2 gene ( ATP8A2). A series of common phenotypical features have been reported in these patients, with few exceptions. Ataxia, mental retardation, and hypotonia were present in all patients, consanguinity in 90% and abnormal movements in 50%. Moreover, 40% achieved ambulation at least once in their lifetime, 40% had microcephaly, whereas 30% were mute. Magnetic resonance imaging (MRI) of the brain was normal in 60% of patients. Conclusions: We described the largest cohort of patients with CAMRQ4 syndrome and identified three novel mutations. CAMRQ4 syndrome should be suspected in patients presenting with ataxia, intellectual disability, hypotonia, microcephaly, choreoathetoid movements, ophthalmoplegia, and global developmental delay, even if brain MRI appears normal.
Latino Solo Grandparents Raising Grandchildren
Authors: Whitley Deborah M. , Fuller-Thomson Esme 
Published: March 2018

Introduction: The purpose of this descriptive report is to provide the first representative information on the sociodemographic profile and the prevalence of mental and physical health conditions of two “at-risk” groups of Latino caregivers: solo grandparent caregivers and single parents. Methods: The 2012 Behavior Risk Factor Surveillance System was used to compare five dimensions of health on a sample of Latino solo grandparents and Latino single parents, raising their grandchildren/children alone. Bivariate and logistic regression comparative analyses were conducted on study measures. Results: Latino solo grandparents have a high prevalence of chronic health conditions, including arthritis (51%), depression (40%), diabetes (34%), and asthma (34%). Latino single parents have lower but troubling health risks, including depression (22%), diabetes (14%), and asthma (14%). Differences between the two groups were largely due to the grandparents older age. Discussion: Latino solo grandparents have a high prevalence of several chronic medical conditions. The prevalence of disorders is much lower for Latino single parents, although they too have disturbing health risks. Conclusion: Latino solo grandparents perform their parenting role under intense physical and emotional strain. Health professionals can be instrumental in facilitating interventions that affect the well-being of this expanding family group.
Outcomes of arteriovenous fistula for hemodialysis in octogenarian population
Authors: Kocaaslan Cemal , Kehlibar Tamer , Yilmaz Mehmet , Mehmetoglu Mehmet E , Gunay Rafet , Aldag Mustafa , Ketenci Bulend , Demirtas Mahmut M 
Published: March 2018

Introduction Guidelines have been recommending the use of arteriovenous fistula among the hemodialysis population, but no clear conclusion has emerged with regard to the adequate access type in octogenarians. In this paper, the outcomes of arteriovenous fistula in octogenarian cohort were presented for death-censored cumulative patency rate, complications, and patients’ survival rate. Methods A retrospective review of 88 consecutive arteriovenous fistula interventions in 70 octogenarian patients were performed at one referral institution between January 2010 and June 2014. The patients’ records were analyzed and postoperative complications were documented. Death-censored cumulative arteriovenous fistula patency rates were calculated, and Kaplan–Meier method was used to analyze patient survival for 24 months. Findings: Eighty-eight arteriovenous fistula constructions and six salvage procedures were performed in 70 octogenarians. Fifty-four (61.3%) forearm and 34 (38.7%) upper arm fistulas were created. All types of fistulas had 6-, 12-, 18-, and 24-month death-censored cumulative patency rates of 63.6%, 58.3%, 48.8%, and 41.4%, respectively. The primary failure rate was 40.9%. A total of 15 complications were documented as edema, hematoma/bleeding, infection, distal ischemia, and venous aneurysm, all of which had been treated. Patient survival rates for 12 and 24 months were 68.5% and 58.5%, respectively. Discussion and conclusion: This analysis regarding arteriovenous fistula in octogenarian end-stage renal disease patients figured out equal death-censored cumulative patency compared to nonelderly, and two-year survival rate was acceptable. This study strengthens the argument that arteriovenous fistula should be the best proper choice in selected octogenarians; older age only should not be considered as an absolute contraindication for arteriovenous fistula creation in octogenarians; and patient-based approach should be applied.
The contribution of internet use in personal networks of support for long-term condition self-management
Authors: Allen Chris , Vassilev Ivaylo , Lin Sharon Xiaowen , Culliford David , Rogers Anne 
Published: March 2018

Objectives To describe the individual and network characteristics of the personal communities of people using the internet and the role of offline support, network resources and community participation in using the internet for condition management. Methods Secondary analysis of survey data using logistic regression analysis to determine the factors associated with differential internet use for condition management. This study involved 300 participants from 19 primary care providers in Manchester in 2010 and 2011. Results Using the internet is associated with age, deprivation, education and having access to a personal network member who understands how to fix computer problems. Those using the internet for condition management received more offline emotional work. No associations were found between using the internet for health and other types of offline support. Those using the internet for support reported lower levels of happiness. Conclusion Network processes and engagement shape online contact and use of resources for condition management. Those with access to personal networks who provide emotional work are likely to make use of online resources during non-crisis situations, suggesting that these resources act as an extension of offline network support. Those with greater levels of unhappiness may more frequently look to the internet for support.