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https://www.readbyqxmd.com/read/29203113/improved-separation-by-at-column-dilution-in-preparative-hydrophilic-interaction-chromatography
#1
Geoffrey Jaffuel, Laura Chappuis, Davy Guillarme, Ted C J Turlings, Gaétan Glauser
We evaluated at-column dilution (ACD) as a possible approach to reduce peak distortion caused by the injection of strong solvents in preparative hydrophilic interaction chromatography (HILIC). Three model compounds, namely uridine, cytidine and guanosine were selected and injected either in conventional or ACD conditions, using various proportions of water and acetonitrile in the sample diluent. Plate number and peak capacity were systematically investigated under both isocratic and gradient elution conditions, respectively...
December 1, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29193495/premature-birth-affects-the-degree-of-airway-dysanapsis-and-mechanical-ventilatory-constraints
#2
Joseph W Duke, Igor M Gladstone, A William Sheel, Andrew T Lovering
Adult survivors of very preterm birth (≤32 weeks gestational age) without (PRE) and with bronchopulmonary dysplasia (BPD) have obstructive lung disease as evidenced by reduced expiratory airflow at rest and have significant mechanical ventilatory constraints during exercise. Airflow obstruction, under any condition, could be due to several factors including small airways. PRE and/or BPD could have smaller airways than their counterparts born at full-term (CON) due to a greater degree of dysanaptic airway development during the pre- and/or post-natal period...
November 29, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/29190612/assessment-of-bronchial-obstruction-using-lateral-pressure-measurement-during-bronchoscopy
#3
Hiroki Nishine, Takehiko Hiramoto, Takeo Inoue, Naoki Furuya, Hirotaka Kida, Hiroshi Handa, Seiichi Nobuyama, Masamichi Mineshita, Teruomi Miyazawa
BACKGROUND: In patients with bronchial obstruction estimating the location of the maximal obstruction is crucial for guiding interventional bronchoscopy. However, flow-volume curves cannot discriminate between the right and left lungs. OBJECTIVES: The aim of this study was to physiologically evaluate bronchial obstruction during interventional bronchoscopy. METHODS: We prospectively measured lateral airway pressure (Plat) at either side of the obstruction using a double-lumen catheter (pressure-pressure [P-P] curve) simultaneously to assess the degree of bronchial obstruction in 22 patients...
November 30, 2017: Respiration; International Review of Thoracic Diseases
https://www.readbyqxmd.com/read/29097129/recycling-potential-of-post-consumer-plastic-packaging-waste-in-finland
#4
Helena Dahlbo, Valeria Poliakova, Ville Mylläri, Olli Sahimaa, Reetta Anderson
Recycling of plastics is urged by the need for closing material loops to maintain our natural resources when striving towards circular economy, but also by the concern raced by observations of plastic scrap in oceans and lakes. Packaging industry is the sector using the largest share of plastics, hence packaging dominates in the plastic waste flow. The aim of this paper was to sum up the recycling potential of post-consumer plastic packaging waste in Finland. This potential was evaluated based on the quantity, composition and mechanical quality of the plastic packaging waste generated by consumers and collected as a source-separated fraction, within the mixed municipal solid waste (MSW) or within energy waste...
October 30, 2017: Waste Management
https://www.readbyqxmd.com/read/29080776/comprehensive-computational-assessment-of-blood-flow-characteristics-of-left-ventricle-based-on-in-vivo-mri-in-presence-of-artificial-myocardial-infarction
#5
Ali Imanparast, Nasser Fatouraee, Farhad Sharif
BACKGROUND: Understanding the effects of cardiac diseases on the heart's functionality which is the purpose of many biomedical researches, directly affects the diagnostic and therapeutic methods. Myocardial infarction (MI) is a common complication of cardiac ischemia, however, the impact of MI on the left ventricle (LV) flow patterns has not been widely considered by computational fluid dynamics studies thus far. METHODS: In this study, we present an insightful numerical method that creates an artificial MI on an image-based fluid-structure interactional model of normal LV to investigate its influence on the flow in comparison with the normal case...
October 26, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/29067926/rare-tracheal-tumor-solitary-plasmacytoma
#6
R Stevic, M Ercegovac, J Stojšić, N Čolić
Primary tracheal tumors are rare and trachea is an exceedingly rare site of extramedullary plasmacytoma (EMP). We report a case of solitary tracheal plasmacytoma causing symptoms of airway obstruction in a 59-year-old man. Flow/volume loop indicated the fixed central airway obstruction. Computerized tomography and bronchoscopy demonstrated a sessile tumor on posterior tracheal wall obstructing 80% of the lumen. Partial tracheal resection with T-T anastomosis was performed. Pathologic analysis of resected mass revealed EMP...
October 23, 2017: Journal of Postgraduate Medicine
https://www.readbyqxmd.com/read/29056459/low-flow-support-of-the-chronic-pressure-overloaded-right-ventricle-induces-reversed-remodeling
#7
Tom Verbelen, Piet Claus, Daniel Burkhoff, Ronald B Driesen, Chandan Kadur Nagaraju, Erik Verbeken, Karin Sipido, Marion Delcroix, Filip Rega, Bart Meyns
BACKGROUND: Mechanical right ventricular (RV) support in pulmonary arterial hypertension patients has been feared to cause pulmonary hemorrhage and to be detrimental for the after-load-sensitive RV. Continuous low-flow pumps offer promise but remain insufficiently tested. METHODS: The pulmonary artery was banded in 20 sheep in this study. Eight weeks later, a Synergy micro-pump (HeartWare International, Framingham MA) was inserted in 10 animals, driving blood from the right atrium to the pulmonary artery...
September 29, 2017: Journal of Heart and Lung Transplantation
https://www.readbyqxmd.com/read/29053169/whole-body-physiologically-based-modelling-of-beta-blockers-in-the-rat-events-in-tissues-and-plasma-following-an-intravenous-bolus-dose
#8
S Y A Cheung, T Rodgers, L Aarons, I Gueorguieva, G L Dickinson, S Murby, C Brown, B Collins, M Rowland
BACKGROUND AND PURPOSE: Whole body physiologically based pharmacokinetic (PBPK) models have been increasingly applied in drug development to describe kinetic events of therapeutic agents in animals and human. The advantage of such modelling is the ability to incorporate vast amounts of physiological information, such as organ blood flow and volume, to ensure that the model is as close to reality as possible. EXPERIMENTAL APPROACH: Prior PBPK model development of enantiomers of a series of seven racemic betablockers, namely acebutolol, betaxolol, bisoprolol, metoprolol, oxprenolol, pindolol and propranolol, together with S-timolol in rat was based on tissue and blood concentration data at steady state...
October 20, 2017: British Journal of Pharmacology
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
#9
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...
December 1, 2017: Health Policy and Planning
https://www.readbyqxmd.com/read/28985746/porcine-model-of-progressive-cardiac-hypertrophy-and-fibrosis-with-secondary-postcapillary-pulmonary-hypertension
#10
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
#11
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
#12
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
#13
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...
November 2017: Alimentary Pharmacology & Therapeutics
https://www.readbyqxmd.com/read/28875449/an-extracorporeal-carbon-dioxide-removal-ecco2r-device-operating-at-hemodialysis-blood-flow-rates
#14
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
#15
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
#16
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
#17
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
#18
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
#19
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
#20
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
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