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https://www.readbyqxmd.com/read/29029075/improving-health-systems-performance-in-low-and-middle-income-countries-a-system-dynamics-model-of-the-pay-for-performance-initiative-in-afghanistan
#1
O Alonge, S Lin, T Igusa, D H Peters
System dynamics methods were used to explore effective implementation pathways for improving health systems performance through pay-for-performance (P4P) schemes. A causal loop diagram was developed to delineate primary causal relationships for service delivery within primary health facilities. A quantitative stock-and-flow model was developed next. The stock-and-flow model was then used to simulate the impact of various P4P implementation scenarios on quality and volume of services. Data from the Afghanistan national facility survey in 2012 was used to calibrate the model...
September 23, 2017: Health Policy and Planning
https://www.readbyqxmd.com/read/28985746/porcine-model-of-progressive-cardiac-hypertrophy-and-fibrosis-with-secondary-postcapillary-pulmonary-hypertension
#2
Mariann Gyöngyösi, Noemi Pavo, Dominika Lukovic, Katrin Zlabinger, Andreas Spannbauer, Denise Traxler, Georg Goliasch, Ljubica Mandic, Jutta Bergler-Klein, Alfred Gugerell, Andras Jakab, Zsuzsanna Szankai, Levente Toth, Rita Garamvölgyi, Gerald Maurer, Frederic Jaisser, Faiez Zannad, Thomas Thum, Sándor Bátkai, Johannes Winkler
BACKGROUND: Meaningful translational large animal models for cardiac diseases are indispensable for studying disease mechanisms, development of novel therapeutic strategies, and evaluation of potential drugs. METHODS: For induction of heart failure, cardiac hypertrophy and fibrosis, a bare metal stent was implanted in the descending aorta of growing pigs (n = 7), inducing pressure stress on the left ventricle (group HYPI). The constant stent size in growing pigs resulted in antegrade partial obstruction of the aortic flow with a gradual increase in afterload...
October 6, 2017: Journal of Translational Medicine
https://www.readbyqxmd.com/read/28977686/in-loop-flow-11-c-co2-fixation-and-radiosynthesis-of-n-n-11-c-dibenzylurea
#3
Joseph Downey, Salvatore Bongarzonev, Stefan Hader, Antony D Gee
Cyclotron-produced carbon-11 is a highly valuable radionuclide for the production of positron emission tomography (PET) radiotracers. It is typically produced as relatively unreactive carbon-11 carbon dioxide ([(11) C]CO2 ) which is most commonly converted into a more reactive precursor for synthesis of PET radiotracers. The development of [(11) C]CO2 fixation methods have more recently enabled the direct radiolabeling of a diverse array of structures directly from [(11) C]CO2 , and the advantages afforded by the use of a loop-based system employed in (11) C-methylation and (11) C-carboxylation reactions inspired us to apply the [(11) C]CO2 fixation "in-loop"...
October 4, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/28961240/myocardial-wall-stiffening-in-a-mouse-model-of-persistent-truncus-arteriosus
#4
Christine Miller Buffinton, Alyssa K Benjamin, Ashley N Firment, Anne M Moon
BACKGROUND: Genetic and epigenetic programs regulate dramatic structural changes during cardiac morphogenesis. Concurrent biomechanical forces within the heart created by blood flow and pressure in turn drive downstream cellular, molecular and genetic responses. Thus, a genetic-morphogenetic-biomechanical feedback loop is continually operating to regulate heart development. During the evolution of a congenital heart defect, concomitant abnormalities in blood flow, hemodynamics, and patterns of mechanical loading would be predicted to change the output of this feedback loop, impacting not only the ultimate morphology of the defect, but potentially altering tissue-level biomechanical properties of structures that appear structurally normal...
2017: PloS One
https://www.readbyqxmd.com/read/28940225/treatment-of-refractory-ascites-with-an-automated-low-flow-ascites-pump-in-patients-with-cirrhosis
#5
G Stirnimann, T Berg, L Spahr, S Zeuzem, S McPherson, F Lammert, F Storni, V Banz, J Babatz, V Vargas, A Geier, A Stallmach, C Engelmann, C Trepte, J Capel, A De Gottardi
BACKGROUND: Refractory ascites (RA) is a frequent complication of cirrhosis, requiring large volume paracentesis or placement of a transjugular intrahepatic portosystemic shunt (TIPSS). The automated low-flow ascites pump (alfapump, Sequana Medical AG, Zurich, Switzerland) is an innovative treatment option for patients with RA. AIM: To assess safety and efficacy of this treatment in patients with a contraindication to TIPSS. METHODS: Fifty-six patients (43 males; mean age 62 years) from centres in Germany, Switzerland, UK and Spain were included and followed for up to 24 months...
September 21, 2017: Alimentary Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28875449/an-extracorporeal-carbon-dioxide-removal-ecco2r-device-operating-at-hemodialysis-blood-flow-rates
#6
R Garrett Jeffries, Laura Lund, Brian Frankowski, William J Federspiel
BACKGROUND: Extracorporeal carbon dioxide removal (ECCO2R) systems have gained clinical appeal as supplemental therapy in the treatment of acute and chronic respiratory injuries with low tidal volume or non-invasive ventilation. We have developed an ultra-low-flow ECCO2R device (ULFED) capable of operating at blood flows comparable to renal hemodialysis (250 mL/min). Comparable operating conditions allow use of minimally invasive dialysis cannulation strategies with potential for direct integration to existing dialysis circuitry...
September 6, 2017: Intensive Care Medicine Experimental
https://www.readbyqxmd.com/read/28874820/image-based-closed-loop-feedback-for-highly-mono-dispersed-microdroplet-production
#7
D F Crawford, C A Smith, G Whyte
Micron-scale droplets isolated by an immiscible liquid can provide miniaturised reaction vessels which can be manipulated in microfluidic networks, and has seen a rapid growth in development. In many experiments, the precise volume of these microdroplets is a critical parameter which can be influenced by many external factors. In this work, we demonstrate the combination of imaging-based feedback and pressure driven pumping to accurately control the size of microdroplets produced in a microfluidic device. The use of fast-response, pressure-driving pumps allows the microfluidic flow to be quickly and accurately changed, while directly measuring the droplet size allows the user to define the more meaningful parameters of droplet size and generation frequency rather than flow rates or pressures...
September 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28862717/an-original-valveless-artificial-heart-providing-pulsatile-flow-tested-in-mock-circulatory-loops
#8
Piergiorgio Tozzi, Audrey Maertens, Jonathan Emery, Samuel Joseph, Matthias Kirsch, François Avellan
PURPOSE: We present the test bench results of a valveless total artificial heart that is potentially compatible with the pediatric population. METHODS: The RollingHeart is a valveless volumetric pump generating pulsatile flow. It consists of a single spherical cavity divided into 4 chambers by 2 rotating disks. The combined rotations of both disks produce changes in the volumes of the 4 cavities (suction and ejection). The blood enters/exits the spherical cavity through 4 openings that are symmetrical to the fixed rotation axis of the first disk...
August 11, 2017: International Journal of Artificial Organs
https://www.readbyqxmd.com/read/28856715/feasibility-of-quantitative-regional-ventilation-and-perfusion-mapping-with-phase-resolved-functional-lung-preful-mri-in-healthy-volunteers-and-copd-cteph-and-cf-patients
#9
Andreas Voskrebenzev, Marcel Gutberlet, Filip Klimeš, Till F Kaireit, Christian Schönfeld, Alexander Rotärmel, Frank Wacker, Jens Vogel-Claussen
PURPOSE: In this feasibility study, a phase-resolved functional lung imaging postprocessing method for extraction of dynamic perfusion and ventilation parameters using a conventional 1H lung MRI Fourier decomposition acquisition is introduced. METHODS: Time series of coronal gradient-echo MR images with a temporal resolution of 288 to 324 ms of two healthy volunteers, one patient with chronic thromboembolic hypertension, one patient with cystic fibrosis, and one patient with chronic obstructive pulmonary disease were acquired at 1...
August 30, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28814081/monitoring-genetic-population-biomarkers-for-wastewater-based-epidemiology
#10
Zhugen Yang, Gaolian Xu, Julien Reboud, Barbara Kasprzyk-Hordern, Jonathan M Cooper
We report a rapid "sample-to-answer" platform that can be used for the quantitative monitoring of genetic biomarkers within communities through the analysis of wastewater. The assay is based on the loop-mediated isothermal amplification (LAMP) of nucleic acid biomarkers and shows for the first time the ability to rapidly quantify human-specific mitochondrial DNA (mtDNA) from raw untreated wastewater samples. mtDNA provides a model population biomarker associated with carcinogenesis including breast, renal and gastric cancers...
August 29, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28741664/in-vitro-evaluation-of-an-immediate-response-starling-like-controller-for-dual-rotary-blood-pumps
#11
Andrew F Stephens, Michael C Stevens, Shaun D Gregory, Matthias Kleinheyer, Robert F Salamonsen
Rotary ventricular assist devices (VADs) are used to provide mechanical circulatory support. However, their lack of preload sensitivity in constant speed control mode (CSC) may result in ventricular suction or venous congestion. This is particularly true of biventricular support, where the native flow-balancing Starling response of both ventricles is diminished. It is possible to model the Starling response of the ventricles using cardiac output and venous return curves. With this model, we can create a Starling-like physiological controller (SLC) for VADs which can automatically balance cardiac output in the presence of perturbations to the circulation...
July 25, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28732941/comments-on-the-use-of-loop-reactors-in-sonochemical-processes
#12
M Vinatoru, Timothy Mason
For sonochemical processing on an industrial scale the traditional choice is either a batch or flow system. The former is straightforward in concept but it requires large scale powerful ultrasonic transducers capable of delivering high intensity ultrasound to large volumes of liquid. Unfortunately at the moment the cost and problems involved in building very large sonication devices for batch processes cannot justify the replacement of existing industrial processes. For this reason most sonochemists prefer some form of flow system where small quantities of reagents can be treated as they are pumped from a large vat of reagents through a smaller sonochemical reactor where high intensity ultrasound can be applied...
November 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28722131/kept-in-the-loop-longitudinal-strain-volume-relationships-for-the-assessment-of-left-ventricular-mechanical-performance
#13
Stephen P Wright, Robert Lakin, Denise J Wooding, Leah Groves
No abstract text is available yet for this article.
September 1, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28711449/intrarenal-flow-alterations-during-transition-from-euvolemia-to-intravascular-volume-expansion-in-heart-failure-patients
#14
Petra Nijst, Pieter Martens, Matthias Dupont, W H Wilson Tang, Wilfried Mullens
OBJECTIVES: The goal of this study was to assess: 1) the intrarenal flow in heart failure (HF) patients during the transition from euvolemia to intravascular volume overload; and 2) the relationship between intrarenal flow and diuretic efficiency. BACKGROUND: Intrarenal blood flow alterations may help to better understand impaired volume handling in HF. METHODS: Resistance index (RI) and venous impedance index (VII) were assessed in 6 healthy subjects, 40 euvolemic HF patients with reduced ejection fraction (HFrEF) and 10 HF patients with preserved ejection fraction (HFpEF)...
July 6, 2017: JACC. Heart Failure
https://www.readbyqxmd.com/read/28695443/3d-experimental-and-computational-analysis-of-eccentric-mitral-regurgitant-jets-in-a-mock-imaging-heart-chamber
#15
Yifan Wang, Annalisa Quaini, Sunčica Čanić, Marija Vukicevic, Stephen H Little
Mitral valve regurgitation (MR) is a disorder of the heart in which the mitral valve does not close properly. This causes an abnormal leaking of blood backwards from the left ventricle into the left atrium during the systolic contractions of the left ventricle. Noninvasive assessment of MR using echocardiography is an ongoing challenge. In particular, a major problem are eccentric or Coanda regurgitant jets which hug the walls of the left atrium and appear smaller in the color Doppler image of regurgitant flow...
July 10, 2017: Cardiovascular Engineering and Technology
https://www.readbyqxmd.com/read/28614118/the-renal-response-to-potassium-stress-integrating-past-with-present
#16
Cary R Boyd-Shiwarski, Arohan R Subramanya
PURPOSE OF REVIEW: The current review combines past findings with recent advances in our understanding of the homeostatic response to potassium imbalance. RECENT FINDINGS: Following the ingestion of a dietary potassium load, a combination of extrarenal and renal mechanisms act to maintain extracellular K+ within a tight window. Through hormonal regulation and direct K+ sensing, the nephron is ideally suited to respond to wide shifts in external K+ balance. Current evidence indicates that dietary K+ loading triggers a coordinated kaliuretic response that appears to involve voltage-dependent changes in sodium transport across multiple nephron segments, including the proximal tubule, medullary loop of Henle, and distal tubule...
September 2017: Current Opinion in Nephrology and Hypertension
https://www.readbyqxmd.com/read/28597590/in-vitro-evaluation-of-pediatric-hollow-fiber-membrane-oxygenators-on-hemodynamic-performance-and-gaseous-microemboli-handling-an-international-multicenter-multidisciplinary-approach
#17
Shigang Wang, Luiz F Caneo, Marcelo B Jatene, Fábio B Jatene, Idagene A Cestari, Allen R Kunselman, Akif Ündar
The objective of this study was to compare the hemodynamic performances and gaseous microemboli (GME) handling ability of two pediatric oxygenators in a simulated pediatric cardiopulmonary bypass (CPB) model and the importance of adding an arterial filter in the circuit. The circuit consisted of a Braile Infant oxygenator or a Maquet Quadrox-I Pediatric oxygenator without integrated arterial filter (parallel arrangement), 1/4 in. ID tubing A-V loop, and a 12-Fr arterial cannula, primed with lactated Ringer's solution and packed red blood cells...
June 8, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28579836/update-on-the-renal-toxicity-of-iodinated-contrast-drugs-used-in-clinical-medicine
#18
REVIEW
Michele Andreucci, Teresa Faga, Raffaele Serra, Giovambattista De Sarro, Ashour Michael
An important side effect of diagnostic contrast drugs is contrast-induced acute kidney injury (CI-AKI; a sudden decrease in renal function) occurring 48-72 hours after injection of a contrast drug that cannot be attributed to other causes. Its existence has recently been challenged, because of some retrospective studies in which the incidence of AKI was not different between subjects who received a contrast drug and those who did not, even using propensity score matching to prevent selection bias. For some authors, only patients with estimated glomerular filtration rate <30 mL/min/1...
2017: Drug, Healthcare and Patient Safety
https://www.readbyqxmd.com/read/28559470/flow-decay-a-novel-spirometric-index-to-quantify-dynamic-airway-resistance
#19
Anita Oh, Tessa A Morris, Isaac T Yoshii, Timothy A Morris
BACKGROUND: Dynamic airway resistance from obstructive disease causes a concavity in the mid-expiratory portion of the spirometric flow-volume loop. We developed a simple model to measure the exponential decay in air flow during forced exhalation to quantify the extent of dynamic airway obstruction and facilitate the detection of obstructive airway diseases clinically. METHODS: We calculated flow decay as the slope of volume versus ln(1/flow) in mid-exhalation. We derived the normal range in a derivation group of healthy volunteers in whom spirometry had been performed repeatedly...
May 30, 2017: Respiratory Care
https://www.readbyqxmd.com/read/28402103/patient-derived-airway-secretion-dissociation-technique-to-isolate-and-concentrate-immune-cells-using-closed-loop-inertial-microfluidics
#20
Hyunryul Ryu, Kyungyong Choi, Yanyan Qu, Taehong Kwon, Janet S Lee, Jongyoon Han
Assessment of airway secretion cells, both for research and clinical purposes, is a highly desired goal in patients with acute and chronic pulmonary diseases. However, lack of proper cell isolation and enrichment techniques hinder downstream evaluation and characterization of cells found in airway secretions. Here, we demonstrate a novel enrichment method to capture immune-related cells from clinical airway secretions using closed-loop separation of spiral inertial microfluidics (C-sep). By recirculating the output focusing stream back to the input reservoir and running continuously with a high flow processing rate, one can achieve optimal concentration, recovery and purity of airway immune cells from a large volume of diluent, which was not readily possible in the single-pass operation...
May 16, 2017: Analytical Chemistry
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