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https://www.readbyqxmd.com/read/28722131/kept-in-the-loop-longitudinal-strain-volume-relationships-for-the-assessment-of-left-ventricular-mechanical-performance
#1
Stephen P Wright, Robert Lakin, Denise J Wooding, Leah Groves
In health, the aortic valve facilitates unidirectional forward flow from the left ventricle (LV) to the systemic circulation. This article is protected by copyright. All rights reserved.
July 19, 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
#2
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
#3
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
#4
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...
June 12, 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
#5
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
#6
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
#7
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
#8
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...
April 21, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28390491/ferric-reducing-antioxidant-potential-frap-of-antioxidants-using-reaction-flow-chromatography
#9
A Jones, S Pravadali-Cekic, G R Dennis, R Bashir, P J Mahon, R A Shalliker
High performance liquid chromatography coupled with post column derivatisation (HPLC-PCD) may be used to profile the antioxidant content of a sample. There are, however, drawbacks in the use of HPLC-PCD setups; namely the high volume reaction coils that are typically used lowering the observed separation efficiency. Reaction flow chromatography has the ability to overcome these inefficiencies by using a more efficient mixing technique inside the outlet fitting itself, post column reaction loops can be removed with resulting improvement in signal to noise response, plus the separation efficiency is maintained...
May 15, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28372840/restriction-capillaries-as-an-innovative-mixing-unit-for-intermediate-mobile-phase-exchange-in-multidimensional-analysis
#10
Glenn Loos, Konstantin Shoykhet, Monika Dittmann, Deirdre Cabooter
A novel mixing unit is proposed for the serial coupling of orthogonal columns to analyze polar and non-polar compounds in a single run. The principle relies on the isolation of unretained peaks eluting from a first dimension column in a sample loop, before directing them to a second column for separation. Since the mobile phases employed in highly orthogonal separations are not directly compatible, a mixing unit is required to alter the mobile phase composition before executing the second dimension separation...
May 12, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28368344/the-combination-of-micro-diaphragm-pumps-and-flow-sensors-for-single-stroke-based-liquid-flow-control
#11
Christoph Jenke, Jaume Pallejà Rubio, Sebastian Kibler, Johannes Häfner, Martin Richter, Christoph Kutter
With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout-differential pressure based flow sensors and thermal calorimetric flow sensors-are evaluated for their suitability of combining them with mircopumps...
April 3, 2017: Sensors
https://www.readbyqxmd.com/read/28298663/lean-flow-optimizing-cardiopulmonary-bypass-equipment-and-flow-for-obese-patients-a-technique-article
#12
Joshua M Blessing, Jeffrey B Riley
The goal of this chart review was to investigate the use of down-sized cardiopulmonary bypass (CPB) circuits for obese patients. The effects of transitioning from larger to smaller oxygenators, reservoirs, and arteriovenous tubing loops were evaluated through a retrospective review of 2,816 adult non-congenital procedure perfusion records. This technique report and case series is a continuation of our original prescriptive CPB circuit quality improvement project. An algorithm was derived to adjust body surface area (BSA) to lower body mass index (BMI) to provide down-sized extracorporeal circuit components capable of meeting the metabolic needs of the patient...
March 2017: Journal of Extra-corporeal Technology
https://www.readbyqxmd.com/read/28272309/determination-of-the-clean-air-delivery-rate-cadr-of-photocatalytic-oxidation-pco-purifiers-for-indoor-air-pollutants-using-a-closed-loop-reactor-part-ii-experimental-results
#13
Valérie Héquet, Frédéric Batault, Cécile Raillard, Frédéric Thévenet, Laurence Le Coq, Éric Dumont
The performances of a laboratory PhotoCatalytic Oxidation (PCO) device were determined using a recirculation closed-loop pilot reactor. The closed-loop system was modeled by associating equations related to two ideal reactors: a perfectly mixed reservoir with a volume of VR = 0.42 m³ and a plug flow system corresponding to the PCO device with a volume of VP = 5.6 × 10(-3) m³. The PCO device was composed of a pleated photocatalytic filter (1100 cm²) and two 18-W UVA fluorescent tubes. The Clean Air Delivery Rate (CADR) of the apparatus was measured under different operating conditions...
March 6, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28228405/inhibition-of-romk-blocks-macula-densa-tubuloglomerular-feedback-yet-causes-renal-vasoconstriction-in-anesthetized-rats
#14
Magali Araujo, William J Welch, Xiaoyan Zhou, Kathleen Sullivan, Shawn Walsh, Alexander Pasternak, Christopher S Wilcox
The Na+/K+/2Cl- cotransporter (NKCC2) on the loop of Henle is the site of action of furosemide. Since outer medullary potassium channel (ROMK) inhibitors prevent reabsorption by NKCC2, we tested the hypothesis that ROMK inhibition with a novel, selective ROMK inhibitor (Compound C) blocks tubuloglomerular feedback (TGF) and reduces vascular resistance. Loop perfusion of either ROMK inhibitor or furosemide caused dose-dependent blunting of TGF, but the response to furosemide was 10-fold more sensitive (IC50= 10-6M for furosemide and IC50=10-5M for Compound C)...
February 22, 2017: American Journal of Physiology. Renal Physiology
https://www.readbyqxmd.com/read/28214133/dynamic-hyperinflation-in-patients-with-asthma-and-exercise-induced-bronchoconstriction
#15
Olga Mediano, Raquel Casitas, Carlos Villasante, Elisabet Martínez-Cerón, Raúl Galera, Ester Zamarrón, Francisco García-Río
BACKGROUND: Little is known about the behavior of operative lung volumes during exercise in patients with asthma and exercise-induced bronchoconstriction (EIB). OBJECTIVE: To compare the presence of dynamic hyperinflation (DH) in patients with mild asthma with and without EIB and in healthy individuals and to relate the changes in end-expiratory lung volume (EELV) with postexercise airflow reduction. METHODS: A total of 122 consecutive stable patients (>12 years of age) with mild asthma and 38 controls were studied...
April 2017: Annals of Allergy, Asthma & Immunology
https://www.readbyqxmd.com/read/28202552/airway-dynamics-in-copd-patients-by-within-breath-impedance-tracking-effects-of-continuous-positive-airway-pressure
#16
András Lorx, Dorottya Czövek, Zoltán Gingl, Gergely Makan, Bence Radics, Dóra Bartusek, Szabolcs Szigeti, János Gál, György Losonczy, Peter D Sly, Zoltán Hantos
Tracking of the within-breath changes of respiratory mechanics using the forced oscillation technique may provide outcomes that characterise the dynamic behaviour of the airways during normal breathing.We measured respiratory resistance (Rrs) and reactance (Xrs) at 8 Hz in 55 chronic obstructive pulmonary disease (COPD) patients and 20 healthy controls, and evaluated Rrs and Xrs as functions of gas flow (V') and volume (V) during normal breathing cycles. In 12 COPD patients, additional measurements were made at continuous positive airway pressure (CPAP) levels of 4, 8, 14 and 20 hPa...
February 2017: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/28149069/impact-of-yoga-in-a-case-of-vocal-cord-dysfunction-with-dysautonomia
#17
Rozina Wadhwania
A 23-year-old female with a past medical history of gastroesophageal reflux disease presented with shortness of breath induced by exercise and certain odors. She reported the symptoms of autonomic dysfunction including fatigue, chest pain, lightheadedness, headaches, numbness/tingling in the arms and legs, and exercise intolerance. Vital signs were significant for orthostatic intolerance. Volume flow loop in the pulmonary function tests showed a flattening of the inspiratory portion characteristic of vocal cord dysfunction...
January 2017: International Journal of Yoga
https://www.readbyqxmd.com/read/28144465/incidence-rate-of-post-intubation-tracheal-stenosis-in-patients-admitted-to-five-intensive-care-units-in-iran
#18
Roya Farzanegan, Behrooz Farzanegan, Mahdi Zangi, Majid Golestani Eraghi, Shahram Noorbakhsh, Neda Doozandeh Tabarestani, Mohammad Behgam Shadmehr
BACKGROUND: Tracheal stenosis is one of the worst complications associated with endotracheal intubation and it is the most common reason for reconstructive airway surgeries. Due to various local risk factors, the incidence rate of tracheal stenosis may vary in different countries. In order to estimate the incidence rate of post-intubation tracheal stenosis (PITS) in patients admitted to an intensive care unit (ICU), a follow-up study was planned. As there was no similar methodological model in the literature, a feasibility step was also designed to examine the whole project and to enhance the follow-up rate...
September 2016: Iranian Red Crescent Medical Journal
https://www.readbyqxmd.com/read/28105847/compact-ultrahigh-pressure-nanoflow-capillary-liquid-chromatograph
#19
Xiaofeng Zhao, Xiaofeng Xie, Sonika Sharma, Luke T Tolley, Alex Plistil, Hal E Barnett, Martin P Brisbin, Adam C Swensen, John C Price, Paul B Farnsworth, H Dennis Tolley, Stanley D Stearns, Milton L Lee
A compact ultrahigh-pressure nanoflow liquid chromatograph (LC) was developed with the purpose in mind of creating a portable system that could be easily moved to various testing locations or placed in close proximity to other instruments for optimal coupling, such as with mass spectrometry (MS). The system utilized innovative nanoflow pumps integrated with a very low volume stop-flow injector and mixing tee. The system weighed only 5.9 kg (13 lbs) or 4.5 kg (10 lbs) without a controller and could hold up to 1100 bar (16000 psi) of pressure...
January 3, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28047932/tu-h-campus-iep3-02-neurovascular-4d-parametric-imaging-using-co-registration-of-biplane-dsa-sequences-with-3d-vascular-geometry-obtained-from-cone-beam-ct
#20
A Balasubramoniam, D Bednarek, S Rudin, C Ionita
PURPOSE: To create 4D parametric images using biplane Digital Subtraction Angiography (DSA) sequences co-registered with the 3D vascular geometry obtained from Cone Beam-CT (CBCT). METHODS: We investigated a method to derive multiple 4D Parametric Imaging (PI) maps using only one CBCT acquisition. During this procedure a 3D-DSA geometry is stored and used subsequently for all 4D images. Each time a biplane DSA is acquired, we calculate 2D parametric maps of Bolus Arrival Time (BAT), Mean Transit Time (MTT) and Time to Peak (TTP)...
June 2016: Medical Physics
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