Search results for " pumps"
showing 10 items of 28 documents
A more efficient cutting planes approach for the green vehicle routing problem with capacitated alternative fuel stations
2021
AbstractThe Green Vehicle Routing Problem with Capacitated Alternative Fuel Stations assumes that, at each station, the number of vehicles simultaneously refueling cannot exceed the number of available pumps. The state-of-the-art solution method, based on the generation of all feasible non-dominated paths, performs well only with up to 2 pumps. In fact, it needs cloning the paths between every pair of pumps. To overcome this issue, in this paper, we propose new path-based MILP models without cloning paths, for both the scenario with private stations (i.e., owned by the fleet manager) and that with public stations. Then, a more efficient cutting plane approach is designed for addressing both…
A novel technique for intraduodenal administration of drug suspensions/solutions with concurrent pH monitoring applied to ibuprofen formulations
2019
Characterization of dissolution of solid suspended drug particles in vivo is important for developing biopredictive in vitro tests. Therefore, methods to gain deeper insights into particle dissolution in vivo are needed. The soft Bioperm intubation method, a well established tool for investigation of permeability, absorption, metabolism, and drug interactions at predefined locations in the gastroinstinal tract, was modified. The novel intubation method involved pump-controlled infusion of pharmaceutical suspensions as well as simultaneous pH monitoring. This technique was used in a proof of concept study in healthy humans. Plasma sampling and non-compartmental analysis allowed comparison of…
Plasma PCSK9 is a late biomarker of severity in patients with severe trauma injury.
2013
PCSK9 (proprotein convertase subtilisin kexin type 9) is a secreted protease that modulates cholesterol homeostasis by decreasing low-density lipoprotein receptor expression. Low levels of plasma lipoproteins are related to severity of illness and survival in patients of intensive care units (ICU).The aim of the study was to investigate the regulation of plasma PCSK9 and its association with plasma lipid parameters and clinical markers of severity during critical illness.The plasma biobank from the previously published HYPOLYTE prospective study was used to measure PCSK9 concentrations by ELISA at days 0 and 8 in 111 patients admitted to surgical ICU for severe multiple trauma. Patients wer…
Glucose insulin potassium infusion improves systolic function in patients with chronic ischemic cardiomyopathy
2002
Objective: We assessed the effects of glucose–insulin–potassium (GIK) by echocardiography in stable patients with ischemic dysfunction. Methods: Twelve male patients with stable coronary disease (SCD) and ejection fraction (EF) <45% were studied for systolic function. GIK (glucose 30%, 300 insulin units and KCl 6 g/l) was infused at 1 ml/kg per h over 20 min. Hemodynamic and echocardiographic measurements were recorded at rest (T0), at the end (20 min) of GIK infusion (T + 20), 20 and 40 min after the end of the infusion (T + 40 and T + 60). Results: At T + 20, a significant decrease in WMSI (wall motion score index) was observed compared with T0 (2.16±0.14 vs. 2.30±0.16: P<0.05). An increa…
Pulsatile versus continuous oxytocin infusion for the oxytocin challenge test.
1994
In a prospective study, 140 patients had an oxytocin challenge test with either a continuous or a pulsed infusion (one minute of infusion in every five minutes). Both infusion regimens had similar success rates in terms of uterine contractions (97.1 vs 98.6%). The potency ratio (pulsed versus continuous infusion) was significant at 2.7 (1.27 to 5.2), which means that more uterine activity was induced with each mU of oxytocin with pulsatile than with continuous administration. The total amount of oxytocin required to obtain three good contractions in 10 minutes was about 40% less with pulsed administration than with continuous infusion, but the test took 40 minutes longer with the pulsed tha…
Cost analysis of target-controlled infusion-based anesthesia compared with standard anesthesia regimens.
2000
UNLABELLED With the development of new computer-assisted target-controlled infusion (TCI) systems and the availability of short-acting anesthetics, total IV anesthesia (TIVA) has become increasingly popular. The aim of this study was to compare costs of TCI-based anesthesia with two standard anesthesia regimens. Sixty patients undergoing elective laparoscopic cholecystectomy were randomly divided into three groups. Group 1 (TIVA/TCI) received TIVA using a propofol-based TCI system and continuous administration of remifentanil; Group 2 (isoflurane) underwent inhaled anesthesia with isoflurane, fentanyl, and N2O; Group 3 (standard propofol) received fentanyl and N2O and a continuous infusion …
Requirement for the Proton-Pumping NADH Dehydrogenase I of Escherichia Coli in Respiration of NADH to Fumarate and Its Bioenergetic Implications
1997
In Escherichia coli the expression of the nuo genes encoding the proton pumping NADH dehydrogenase I is stimulated by the presence of fumarate during anaerobic respiration. The regulatory sites required for the induction by fumarate, nitrate and O2 are located at positions around –309, –277, and downstream of –231 bp, respectively, relative to the transcriptional-start site. The fumarate regulator has to be different from the O2 and nitrate regulators ArcA and NarL. For growth by fumarate respiration, the presence of NADH dehydrogenase I was essential, in contrast to aerobic or nitrate respiration which used preferentially NADH dehydrogenase II. The electron transport from NADH to fumarate …
Counterdiabatic vortex pump in spinor Bose-Einstein condensates
2017
Topological phase imprinting is a well-established technique for deterministic vortex creation in spinor Bose-Einstein condensates of alkali metal atoms. It was recently shown that counter-diabatic quantum control may accelerate vortex creation in comparison to the standard adiabatic protocol and suppress the atom loss due to nonadiabatic transitions. Here we apply this technique, assisted by an optical plug, for vortex pumping to theoretically show that sequential phase imprinting up to 20 cycles generates a vortex with a very large winding number. Our method significantly increases the fidelity of the pump for rapid pumping compared to the case without the counter-diabatic control, leadin…
Análisis de dos clavos y un rodamiento del pecio Bou Ferrer (La Vila-Joiosa, Alicante)
2020
El pecio Bou Ferrer contiene los restos sumergidos de una nave de comercio romana altoimperial que conserva una parte importante de su arquitectura naval. Analizamos tres objetos de metal procedentes del yacimiento, dos clavos y un hipotético rodamiento de la bomba de achique, para conocer la composición elemental. El resultado ha revelado que los clavos son de cobre y el cojinete de una aleación ternaria de bronce que contiene cobre, estaño y plomo. Este hallazgo abre la posibilidad de investigar el uso especializado del bronce plomado para mejorar el rendimiento mecánico de las bombas de achique en los barcos romanos. The Bou Ferrer wreck contains the underwater remains of a high-empire R…
Organelle pH studies using targeted avidin and fluorescein–biotin
2000
Abstract Background: Mammalian organelles of the secretory pathway are of differing pH. The pH values form a decreasing gradient: the endoplasmic reticulum (ER) is nearly neutral, the Golgi is mildly acidic and the secretory granules are more acidic still (∼pH 5). The mechanisms that regulate pH in these organelles are still unknown. Results: Using a novel method, we tested whether differences in H + ‘leak' and/or counterion conductances contributed to the pH difference between two secretory pathway organelles. A pH-sensitive, membrane-permeable fluorescein–biotin was targeted to endoplasmic-reticulum- and Golgi-localized avidin-chimera proteins in HeLa cells. In live, intact cells, ER pH (…