Search

Background: Connecting an infusion line to a closed stopcock results in pressurization of fluid within the syringe infusion pump assembly leading to flow irregularities when opening the stopcock and activating the pump. Aims: It was the purpose of this study to assess the extent of pressurization under different conditions and its impact on start‐up fluid delivery. Methods: Intraluminal pressures and start‐up fluid delivery at 1 mL/h flow rate were assessed with connection of the infusion line 1 min (delayed connection) or immediately after purging (immediate connection) using two different infusion lines made from polyvinylchloride (PVC) or polyethylene (PE). Results: Delayed connection resulted in an increase of intraluminal pressures from zero to 5.1 [4.5 to 5.7] mmHg with the PVC line and from zero to 47.1 [44.8 to 49.3] mmHg with the PE line (mean difference 42.0 [95% CI 39.3–44.7] mmHg; p <.0001). Immediate connection resulted in an increase of intraluminal pressures from zero to 44.3 [41.8–46.8] mmHg with the PVC line and from zero to 61.3 [57.2–65.4] mmHg with the PE line (mean difference 17.0 [95% CI 11.8–22.2] mmHg; p <.0001). The increase in intraluminal pressures was significantly higher with PE lines for both delayed and immediate connection when compared to the PVC lines (mean difference 29.5 [95% CI 19.3–39.7] mmHg; p <.0001). Related fluid volumes delivered at 10 s and 360 s after starting the pump ranged from −252% to 1321% (10 s) of expected infusion volumes and from 59% to 129% (360 s), respectively. Conclusions: Both, timing of infusion line connection after purging and infusion line characteristics considerably affect intraluminal pressures and start‐up fluid delivery when connecting a new syringe infusion pump assembly to a closed stopcock. Consecutive alterations in drug administration can have considerable hemodynamic consequences when dealing with catecholamine infusions in critically ill patients. [ABSTRACT FROM AUTHOR]

Micropumps have an important influence on the field of microfluidics, with particular interest in pumps based on liquid metal that operate without mechanical moving parts. While previous research has primarily focused on pumping alkaline media, this article aims to advance the field by demonstrating a liquid metal pump suitable for acidic environments. A key strategy involves reducing the interfacial tension between the liquid metal and the surrounding solution through the addition of surface‐active anions (I−). Theoretical analysis first evaluates the effectiveness of this approach. These experimental results confirm that increasing KI concentrations leads to a decrease in interfacial tension, enabling the deformation and actuation of liquid metal droplets at lower voltages compared to acidic media alone. Subsequently, an acidic media pump is constructed, and various parameters influencing its performance are examined, including acidity, iodide anion concentration, voltage, frequency, and droplet volume. This research offers strategies for developing liquid metal pumps with high flow rates and low energy consumption, thereby expanding the application potential of liquid metal in microfluidics. [ABSTRACT FROM AUTHOR]

The crustacean molting cycle is triggered by the elevation of ecdysteroid levels in the hemolymph during late pre‐molt. It is known that these animals absorb water through the intestine and gills to promote bodily swelling and rupture of the old exoskeleton. The participation of two membrane proteins responsible for the most uptake of water during the late pre‐molt has been shown in the gill and gut cells of the freshwater shrimp Palaemon argentinus: Na+/K+‐ATPase (NKA), which generates an osmoionic gradient, and Aquaporins (AQPs), water channels, which provide higher water permeability. Studies investigating the action of ecdysteroids on these proteins are scarce. Therefore, we investigated 20‐hydroxyecdisone (20E) in relation to the regulation of NKA and AQPs in the gill and gut cells of P. argentinus. We exposed primary cultures of both gut and gill cells to 20E. Gill cells treated with hormone in the presence of NKA‐blockers, exhibited a reduction in volume, and cells treated with 20E showed a greater expression of NKA than untreated cells. Additionally, gills cells treated with 20E showed an increase in volume (∼60%), which the aquaporin inhibitor (HgCl2) prevented. The participation of AQPs in the influx of water was corroborated by a greater expression of AQP in cells treated with 20E compared to untreated cells. Gut cells of animals in intermolt exposed to hormone (20E) maintained their initial cell volume. With the addition of HgCl2, these cells showed a reduction in volume similar to cells of animals in pre‐molt. Immunocytochemistry showed a high expression of AQP in gut cells treated with 20E. These findings suggest that 20E regulates the expression of AQP and NKA in the late pre‐molt, to provide water uptake for molting. This work offers new perspectives concerning the molting hormone, placing it as a crucial part of water uptake for ecdysis. [ABSTRACT FROM AUTHOR]

Background: Connection and opening a syringe infusion pump to a central venous line can lead to acute anterograde or retrograde fluid shifts depending on the level of central venous pressure. This may lead to bolus events or to prolonged lag times of intravenous drug delivery, being particularly relevant when administering vasoactive or inotropic drugs in critically ill patients using microinfusion. The aim of this study was to assess the effect of syringe pump positioning at different vertical heights on start‐up fluid delivery before versus after purging and connection the pump to the central venous catheter. Methods: This in vitro study measured ante‐ and retrograde infusion volumes delivered to the central venous line after starting the syringe pump at a set infusion rate of 1 mL/h. In setup one, the pump was first positioned to vertical levels of +43 cm or –43 cm and then purged and connected to a central venous catheter. In setup two, the pump was first purged and connected at zero level and secondarily positioned to a vertical level of +43 cm or –43 cm. Central venous pressure was adjusted to 10 mmHg in both setups. Results: Positioning of the pump prior to purging and connection to the central venous catheter resulted in a better start‐up performance with delivered fluid closer to programmed and expected infusion volumes when compared to the pump first purged, connected, and then positioned. Significant backflow volumes were observed with the pump purged and connected first and then positioned below zero level. No backflow was measured with the pump positioned first below zero level and then purged and connected. Conclusions: Syringe infusion pump assemblies should be positioned prior to purging and connection to a central venous catheter line when starting a new drug, particularly when administering highly concentrated vasoactive or inotropic drugs delivered at low flow rates. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Intravenous administration of highly concentrated and potent drugs at low flow rates is common practice, particularly in critically ill children. Drug delivery during infusion start‐up can be considerably delayed by intrinsic factors of syringe infusion pump assemblies. The impact of central venous pressures on the course of start‐up fluid delivery of such microinfusions remains unknown. Methods: Infusion volumes delivered after activation of the start button in a conventional 50 mL syringe infusion pump assembly equilibrated (representing classical in vitro testing) and not equilibrated (representing real clinical conditions) to central venous pressure levels of 0, 10 and 20 mmHg at a set infusion flow rate of 1 mL/h were measured using a fluidic flow sensor. Results: The experimental setup mimicking real life conditions demonstrated considerable differences in fluid delivery during pump start‐up depending on central venous pressure. A central venous pressure of 0 mmHg resulted in massive fluid delivery at infusion start‐up, while central venous pressure levels of 10 and 20 mmHg resulted in retrograde flows with related mean (95% CI) zero‐drug delivery times of 3.22 (2.98–3.46) min and 4.51 (4.33–4.69) min, respectively (p <.0001). Conclusion: Depending on central venous pressure level, connection and starting a new syringe pump can result in significant antegrade or retrograde fluid volumes. In clinical practice, this can lead to hemodynamic instability and hence requires clinical alertness. Further research and methods to improve start‐up performance in syringe infusion pump systems are desirable. [ABSTRACT FROM AUTHOR]

Background: Intrathecal baclofen (ITB) is a proven, effective treatment for refractory spasticity and chronic pain, with applications ranging from spinal cord injury to amyotrophic lateralsclerosis (ALS). Despite its effectiveness, the withdrawal syndrome of intrathecal baclofen can be life‐threatening. Case Report: This case describes the treatment of a patient with chronic spasticity related to ALS with an ITB pump infection requiring explant and a prolonged period of antibiotics before reimplantation. A 62‐year‐old man with ALS‐related spasticity maintained on high‐dose ITB for 20 years presented to the emergency department with one week of fever, confusion, and localized erythema to the R‐side of his abdomen. Laboratories indicated a mild leukocytosis 12.9 K/uL and imaging showed a 2.9‐cm fluid collection with fat stranding surrounding the ITB pump. The pack was explanted, and the patient started on intravenous antibiotics. Due to the high baclofen dosage, our pain service recommended PO (per os) baclofen 30 mg every 6 h via gastrostomy and PO diazepam 10 mg every 6 h via gastrostomy. These doses were titrated carefully to avoid oversedation while preventing withdrawal symptoms. On Day 23 postexplant, the patient had the baclofen pump reimplanted and baclofen titrated over three days to his previous dose of ITB. Conclusion: This case demonstrates a successful approach to avoiding severe baclofen withdrawal using PO baclofen combined with PO diazepam. The high dose of maintenance ITB (1188.8 mcg/day), the inability to reinsert the patient's intrathecal pump, and the high risk of intubation in a patient with severe neuromuscular dysfunction all made this a challenging case. [ABSTRACT FROM AUTHOR]

Introduction: Indianapolis Coalition for Patient Safety, Inc. (ICPS) identified practice variation across participating health‐systems related to intravenous Patient‐Controlled Analgesia (PCA) in 2018. No evidence‐based published recommendations were available to provide optimization for the medication use process during this evaluation, leading to development of an ad hoc interdisciplinary group to address gaps. Objectives: Primary objectives were to operationalize safe use of PCA and evaluate implementation of ICPS PCA consensus recommendations at an academic medical center by assessing PCA prescribing patterns following policy and electronic health record (EHR) changes. Secondary objectives focused on markers of adoption changes and employee engagement. Methods: ICPS formed an interdisciplinary, diverse group of content experts representing six health‐systems to review current PCA processes. Significant variations were identified, and a gap‐analysis was completed to develop consensus recommendations. To evaluate implementation of these recommendations, a retrospective pre‐/post‐analysis was completed of patients at a safety‐net, academic medical center from March 2021 to July 2022 who received an order for PCA. Prescribing patterns and electronic documentation were analyzed. Results: The ICPS PCA Safety Summit developed 45 consensus recommendations addressing the following PCA medication use processes: ordering, patient assessment, administration, EHR design, documentation tools, smart pump drug library settings, policies, adverse event monitoring, and education. Evaluation included a total of 155 patients. The ordered total number of morphine milligram equivalent (MME) potentially available per day to a patient from PCA, electronic documentation of opioid tolerance, and PCA smart infusion pump review all significantly improved post‐implementation. Conclusion: City‐wide standardization and development of PCA consensus guidelines filled a gap in practice to provide direction and optimization for the medication use process surrounding these high‐alert medications. Organizational results following implementation provide evidence that using new EHR order sets and incorporating opioid tolerance resulted in more intentional PCA prescribing and more thorough electronic nursing documentation. [ABSTRACT FROM AUTHOR]

Polder is usually used for flood control in the river delta area. With the rapid development of urbanization, the dikes or pumps cut the original stream network system, and the stream network connectivity (SNC) and the river system pattern have changed. The dikes or pumps generally force up the river's water level, and regional flood formation mechanisms and processes have changed. In order to quantitatively describe the characteristics of polder‐type flood control measure (PFCM) and the change law of SNC, firstly, the streams inside polders were generalized as virtual streams, a hydrological‐hydrodynamic model was constructed by connecting Hydrologic Engineering Center‐Hydrologic Modeling System and MIKE11 model. Secondly, an SNC evaluation model was constructed based on flow resistance and hydrological process. Finally, the SNC under different scenarios was simulated and evaluated to reveal the influence of the PFCM on SNC. And the dominance analysis method obtained the main control factors of SNC changes. The results showed that the pumps as the main drainage facility under the PFCM, SNC after the opening of the pumps were increased by 0.060, 0.103, and 0.311 for 50%, 30%, and 3% frequency flood scales compared with the pumps closed, respectively. However, compared with the natural stream (without the PFCM), the SNC decreased by 0.391, 0.456, and 0.487, respectively, at the same time of the same flood scale. The PFCM negatively impacted the SNC, and the number of pumps was the main control factor of the SNC. [ABSTRACT FROM AUTHOR]

Objective: Regulatory legislation in both the United States and Canada requires water users with medium to high intake volumes to monitor entrainment losses to determine effects and to assess potential mitigation strategies to reduce harm to fish. Recent studies have recommended the use of both increased sampling frequency and sampling volume to characterize fish entrainment for large power plants on the Great Lakes. There is little doubt that increasing the flow rate and volume of water collected for sampling reduces the uncertainty in estimates of annual entrainment. Depending on the type of pump and the pumping flow rate used for entrainment sampling, considerable damage to fish larvae can occur. A screw‐type centrifugal pump has many qualities that make it ideal for entrainment sampling, but it has not yet been used as a sampling device for fish entrainment applications at power plants or other large industrial water users. The objective of this study was to determine mortality of entrainable fish eggs and larvae due to passage through a screw‐type centrifugal pump. Methods: In a laboratory setting, Lake Trout Salvelinus namaycush eggs and larvae, Lake Whitefish Coregonus clupeaformis eggs, and Rainbow Trout Oncorhynchus mykiss juveniles were passed through a screw‐type centrifugal pump at three treatment flow rates: 39.5, 47.3, and 59.1 m3/h. Fish and eggs were monitored for mortality posttreatment and again at 24 and 48 h. Result: Across treatments, very few mortalities were observed. Species specific moralities were four larval Lake Trout, one Lake Whitefish egg, and one juvenile Rainbow Trout. No mortality was observed for Lake Trout eggs. Conclusion: The present study identified high egg and larval survival (≥99%) after passage through a screw‐type centrifugal pump. High survival reduces error associated with identification and counting of entrained organisms, which provides more accurate estimates of annual entrainment losses. Impact statementA screw‐type centrifugal impeller pump results in high survival of entrainable fish (eggs and larvae), which reduces error associated with estimating fish mortality due to entrainment. Reduced error improves entrainment mortality estimates that may be used to develop compensation strategies to mitigate loss of fish from aquatic systems. [ABSTRACT FROM AUTHOR]

Receptor‐like kinases (RLKs) are a large group of plant‐specific transmembrane proteins mainly acting as receptors or co‐receptors of various extracellular signals. They usually turn extracellular signals into intracellular responses via altering gene expression profiles. However, recent studies confirmed that many RLKs can physically interact with diverse membrane‐localized transport proteins and regulate their activities for speedy responses in limited tissues or cells. In this minireview, we highlight recent discoveries regarding how RLKs can work with membrane transport proteins collaboratively and thereby trigger cellular responses in a precise and rapid manner. It is anticipated that such regulation broadly presents in plants and more examples will be gradually revealed when in‐depth analyses are conducted for the functions of RLKs. [ABSTRACT FROM AUTHOR]

Amphibian populations globally are in decline. One great threat is the abstraction of water resources that alter surface‐water hydrology. Conservation actions aimed at restoring or manipulating surface water are employed as a management tool, but empirical evidence on the effectiveness of these approaches is scarce. In this systematic review, we summarized the global experience of manipulating water for amphibian conservation. We explored examples of manipulating water to conserve amphibian species and communities. Approaches varied in their frequency of implementation and in their success. Extending hydroperiod to match larval requirements showed encouraging results, as did off‐season drying to control predators. Spraying water into the environment showed several potential applications, but successes were limited. Despite some promising interventions, we identified few (n = 17) empirically supported examples of successful water manipulation to benefit amphibians. It is unclear whether this stems from publication bias or if it is an artifact of language selection. However, manipulating water shows some potential in amphibian conservation, particularly at sites with a proximal water source and in regions where aridity is increasing due to climate change. Regardless of the scale of the intervention or its perceived probability of success, high‐quality reporting of empirical results will further understanding of how water manipulations can benefit threatened amphibian populations. Article impact statement: Manipulating water is a promising management tool in amphibian conservation, particularly where aridity increases due to climate change. [ABSTRACT FROM AUTHOR]

This study presents convex modeling of drainage pumps so that real‐time control systems can be implemented to minimize their energy use. A convex model is built based on pump curves and then used in mixed‐integer optimization to allow pumps to be turned on or off. It is implemented as an extension to the open source software package RTC‐Tools. The formulation is such that the continuous relaxations of the mixed‐integer problem are convex, hence branch‐and‐bound techniques may be used to find a global optimum. The formulation can be used for variable‐speed and constant‐speed pumps. There are several possible applications, such as optimization of polder systems, pumped‐storage systems, or certain water distribution networks. Finally, an example of the drainage pump is presented to compare the method to current methods and show that energy can be saved by using the proposed method. Plain Language Summary: Pumps are present in several water systems, like drinking water networks or drainage pumps. Drainage pumps are one of the greatest energy consumers in low‐lying countries. Water managers decide when to turn them on depending on the sea level, weather prediction, and other factors. The operation costs depend on the time of operation. This article explains a method to decide when to turn these pumps on to use the least amount of energy, cheaper, and more sustainable drainage possible. The method can be further applied to any water systems containing pumps. Key Points: Convex modeling of pumps for minimizing energy use is presentedMixed‐integer optimization is used to reach the global optimumRTC‐Tools toolbox is used to minimize energy use of the drainage pumps [ABSTRACT FROM AUTHOR]

Purpose: fMRI is widely used to study brain activity. Unfortunately, conventional fMRI methods assess neuronal activity only indirectly, through hemodynamic coupling. Here, we show that active, steady‐state transmembrane water cycling (AWC) could serve as a basis for a potential fMRI mechanism for direct neuronal activity detection. Methods: AWC and neuronal actitivity in rat organotypic cortical cultures were simultaneously measured with a hybrid MR‐fluorescence system. Perfusion with a paramagnetic MRI contrast agent, Gadoteridol, allows NMR determination of the kinetics of transcytolemmal water exchange. Changes in intracellular calcium concentration, [Cai2+] were used as a proxy of neuronal activity and were monitored by fluorescence imaging. Results: When we alter neuronal activity by titrating with extracellular [K+] near the normal value, we see an AWC response resembling Na+‐K+‐ATPase (NKA) Michaelis‐Menten behavior. When we treat with the voltage‐gated sodium channel inhibitor, or with an excitatory postsynaptic inhibitor cocktail, we see AWC decrease by up to 71%. AWC was found also to be positively correlated with the basal level of spontaneous activity, which varies in different cultures. Conclusions: These results suggest that AWC is associated with neuronal activity and NKA activity is a major contributor in coupling AWC to neuronal activity. Although AWC comprises steady‐state, homeostatic transmembrane water exchange, our analysis also yields a simultaneous measure of the average cell volume, which reports any slower net transmembrane water transport. [ABSTRACT FROM AUTHOR]

Worldwide the number of people with diabetes mellitus is increasing. There are estimations that diabetes is one of the leading causes of death. The most important goals for the treatment of diabetes are self‐management of the disease and an optimal quality of diabetes control. In the therapy new technologies, like real‐time continuous interstitial glucose monitoring, continuous subcutaneous insulin infusion (CSII), electronic tools for the monitoring of therapeutic approaches, automated bolus calculators for insulin and electronic tools for education and information of patients, have become widespread and play important roles. All these efforts are related to the interaction between patients, caregivers, scientists or researchers and industry. The presentation of different aspects of new technological approaches in the present article should give more information about different technologies. However, because of the rather quickly appearance of new technologies, the presentation can only be a spotlight. Further studies are mandatory to analyze the effects and long‐term benefits of each technology and electronic device. [ABSTRACT FROM AUTHOR]

Ketorolac tromethamine is a nonsteroidal anti-inflammatory drug that exhibits analgesic activity with no sedative or anxiolytic properties. Twelve healthy male subjects were enrolled in a study to receive either of 2 treatments over 2 periods in an open-label, randomized, 2-way crossover design: (A) 120 mg of ketorolac tromethamine administered as a continuous subcutaneous infusion over a 24-hour period; or (B) an identical total daily dose administered as 4 intramuscular bolus injections of 30 mg each given every 6 hours (current labeled treatment regimen). The pharmacokinetic and safety profiles were evaluated for both treatments. Both modes of administration have similar values for area under the curve (AUC) and half-life (t1/2), suggesting that continuous subcutaneous infusion and repeated intramuscular bolus injections have similar bioavailability. The peak plasma concentration (Cmax) was 40% lower when ketorolac was administered as a continuous subcutaneous infusion compared with repeat intramuscular bolus injections. The concentration at steady-state (Css) for continuous subcutaneous infusion was between the Cmax and Ctrough values obtained following the 4 intramuscular injections. Both treatment arms were well tolerated. [ABSTRACT FROM AUTHOR]

Abstract: We observed the curative effect of the 3C insulin system in combination with non‐invasive ventilation in a patient with type 2 diabetes and obstructive sleep apnea syndrome (OSAS). The 3C insulin pump is a system of devices that closely monitors and effectively regulates blood glucose levels. Non‐invasive ventilation has been shown to be an effective treatment for OSAS. A type 2 diabetes patient with concomitant OSAS was treated with a 3C insulin pump system for real‐time continuous glucose monitoring and nocturnal non‐invasive ventilation for OSAS. Treatment‐induced diabetic remission with improved sleep and reduced hypoglycemic episodes was achieved. Therefore, the 3C insulin pump system, in combination with non‐invasive ventilation, is an effective treatment for type 2 diabetes patients with concomitant OSAS. [ABSTRACT FROM AUTHOR]

Water quality monitoring programs across multiple disciplines use total suspended solids ( TSS), and volatile suspended solids ( VSS), to assess potential impairments of surface water and groundwater. While previous methods for instream filtering have been developed, the need for rapid, cost-effective, high volume sampling has increased with the need to verify and supplement data produced by sondes and instantaneous data loggers. We present an efficient method to filter water instream with a portable drill pump that results in reduced sample processing time, and potentially reduced error associated with sample transportation, preservation, contamination, and homogenization. This technical note outlines the advantages of filtering instream vs. in the laboratory. It also compares TSS and VSS concentrations filtered with a drill pump vs. standard filtration methods with a vacuum pump as outlined by USEPA methods 160.2 and 160.4. Samples were collected at 4 sites and filtered in the field, or transported to the laboratory and filtered within 12 or 24 h of collection. Overall TSS and VSS samples filtered instream with a drill pump vs. in the laboratory produced similar concentrations with a similar range in variability for each method. Sample filtering with a drill pump decreased processing time by five minutes per sample. [ABSTRACT FROM AUTHOR]

Low flow rate pumping of cell suspensions finds current applications in bioreactors for short-term dynamic cell culture and adhesion assays. The aim of this study was to develop an atraumatic pump and hemodynamically adapted test circuit to allow operating periods of at least several hours. A computer-controlled mini-pump ( MP) was constructed based on non-occlusive local compression of an elastic tube with commercial bi-leaflet valves directing the pulsatile flow into a compliant circuit. Cell damage and activation in the system were tested with whole blood in comparison with a set with a conventional peristaltic pump ( PP). Activation of circulating THP-1 monocytes was tested by measuring the expression of CD54 ( ICAM-1). Additionally, monocyte-endothelial interactions were monitored using a parallel-plate flow chamber with an artificial stenosis. The system required a priming volume of only 20 mL, delivering a peak pulsatile flow of up to 35 mL/min. After 8 h, blood hemolysis was significantly lower for MP with 11 ± 3 mg/ dL compared with PP with 100 ± 16 mg/ dL. CD142 (tissue factor) expression on blood monocytes was 50% lower for MP. With MP, THP-1 cells could be pumped for extended periods (17 h), with no enhanced expression of CD54 permitting the long-term co-culture of THP-1 with endothelial cells and the analysis of flow pattern effects on cell adhesion. A low-damage assay setup was developed, which allows the pulsatile flow of THP-1 cells and investigation of their interaction with other cells or surfaces for extended periods of time. [ABSTRACT FROM AUTHOR]

Over the last 20 years, conventional automotive engine ancillaries have migrated from being mechanically powered to electrically powered in order to meet market demand. To adopt this trend in heavy trucks requires a higher power electrical system in order to cope with the higher loads placed upon it. Until the advent of the hybrid electric heavy truck (HET) this power infrastructure has not been available. HET's require a higher voltage system in order to reduce losses and provide adequate power and voltage levels for the traction motor. This study investigates for the first time the benefit of electrifying a hydraulic power assisted steering system in an HET. The developed electrical hydraulic power steering (EHPS), using a high‐voltage traction battery, is found to drastically reduce the consumed energy over a drive cycle by optimal operation of the pump over the driving cycle. Empirical data from a prototype HET with EHPS confirms the simulation results from Dymola. [ABSTRACT FROM AUTHOR]

Analyses in chromatographic systems able to save mobile and stationary phases without reducing efficiency and resolution are of current interest. These advantages regarding savings have challenged us to develop a system dedicated to miniaturized liquid chromatography. This paper reports on the development of a high-pressure syringe-type pump, an oven able to perform isothermal and temperature programming and a software program to control these chromatographic devices. The experimental results show that the miniaturized system can generate reproducible and accurate temperature and flow rate. The system was applied to the separation of statins and tetracylines and showed excellent performance. [ABSTRACT FROM AUTHOR]

Aim Carbohydrate counting ( CC) is widely used in insulin pumps. The primary objectives of this study were improvement of HbA1c and meal-related plasma glucose (PG) levels when using CC. Methods Forty patients with pump treatment, aged 13.8 ± 3.4 yr (range 5.0-19.5) and diabetes duration 8.0 ± 3.8 (1.8-16.8) years completed a 1-yr multi-center study. HbA1c at start was 7.6 ± 0.9% Diabetes Control and Complications Trial ( DCCT), 59 ± 10 mmol/mol International Federation for Clinical Chemistry and Laboratory Medicine ( IFCC). They were randomized into (A) control group, (B) manual CC, and (C) CC with a bolus calculator in the pump for calculations. (B) and (C) received education in CC while (A) received equal hours of traditional dietary education. Glucose meters were downloaded at visits and the standard deviation ( PG-SD) calculated. PG measurements from before and 2 h after meals were registered separately. Results We found no difference in HbA1c between the groups. Group C had a non-significant decrease in PG-SD (p = 0.056) compared to start, and a significantly higher number of post-meal PG between 4 and 8 mmol/L at 12 months compared to group A (55.3% vs. 30.6%, p = 0.014). The frequency of hypoglycemia was reduced for the whole study group (p = 0.01), but with no significant difference between groups. (A) significantly increased their basal-insulin dosage at 12 months. In (C), all subjects wanted to continue CC after the study. The insulin:carbohydrate ratio correlated significantly to the insulin-dose/24 h (p = 0.003) and the correction factor to the insulin-dose/24 h (p = 0.035) and age (p < 0.001). Conclusions We conclude that CC using a bolus calculator may help decrease PG-fluctuations and increase post-meal PG values within target. [ABSTRACT FROM AUTHOR]

Study Objective To examine the effect of the drug interaction between clopidogrel and proton pump inhibitors ( PPIs) on the risk of an adverse cardiovascular event. Design Population-based, retrospective cohort study. Data Source IMS LifeLink Health Plan administrative claims database. Patients A total of 10,101 patients aged 18 years or older with a diagnosis of acute coronary syndrome ( ACS) made during a hospitalization or emergency department visit between 2001 and 2008 and who had their first clopidogrel prescription within 90 days after their ACS diagnosis were included in the study. Patients were stratified according to concurrent use (clopidogrel plus PPI group) or no use (clopidogrel alone group) of the following PPIs: esomeprazole, lansoprazole, omeprazole, pantoprazole, or rabeprazole. Measurements and Main Results Data were collected on baseline patient demographic and clinical characteristics. Patients were followed from their first clopidogrel prescription until they experienced an adverse cardiovascular event, defined as inpatient hospitalization or emergency department visits for myocardial infarction, percutaneous coronary intervention, or intermediate coronary syndrome; were disenrolled; discontinued clopidogrel; or reached the end of the study period. Using a propensity scoring method, the clopidogrel plus PPI group was matched in a 1:1 ratio with the clopidogrel alone group. Exposure to overlapping clopidogrel- PPI prescriptions was modeled as a time-dependent covariate. The Cox hazards regression model was used to estimate the risk of an adverse cardiovascular event in the clopidogrel plus PPI group versus the clopidogrel alone group. Propensity score matching resulted in 2674 patient pairs. In the propensity score-matched sample, the mean age was 61.30 years, with a mean follow-up of 268 days, and 70.04% were male. Concurrent use of clopidogrel with a PPI was associated with a significantly increased risk of a cardiovascular adverse event (hazard ratio 1.438, 95% confidence interval 1.237-1.671) compared with clopidogrel alone. Conclusion Concurrent use of clopidogrel plus a PPI was associated with a significant increase in risk of an adverse cardiovascular event in patients with ACS. Large randomized studies are needed to confirm this finding. Until then, clinicians should prescribe the concurrent use of these two drugs cautiously. [ABSTRACT FROM AUTHOR]

The total number and condition of fish extracted via high and low flow irrigation pumps was assessed over a 2-year period in the Namoi River, Australia. A combination of boat electric fishing and fyke netting was used for 10 weeks during the peak irrigation period to determine species and size classes susceptible to entrainment during water abstraction. Over 2300 fish passed through the pump outlets over the study period, with many individuals (7.5% of total) both killed and injured. The maximum number of fish entrained in a single day was 232. Mortality was significantly higher from the high volume pump site, but only large (>200 mm long) or small (<50 mm long) fish were killed. Medium-sized fish (50–200 mm long) largely survived the abstraction process; although 70 were injured (3% of total), only one was killed (0.07%). The Electric fishing surveys showed that only four species were present in storage dams, suggesting that survival through the pump systems may be size and species specific. Fish that survived the water abstraction process had no opportunities to return to the main river system and were effectively classified as lost from the main river population. The development of suitable mitigation measures, including operational changes and screening, are suggested as mechanisms to prevent extraction and minimise any adverse impacts arising from irrigation development. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the performance in terms of red cell damage of two peristaltic volumetric infusion pumps – the Alaris IVAC 572 (San Diego, CA, USA) and Arcomed Volumed VP7000 (Regensdorf, Switzerland). Various infusion pumps are available to transfuse blood at a predetermined rate. It is recommended that each machine should be individually assessed. This experiment used six units of single-donor-transfusable packed red cells and ran each unit through both pumps. This was carried out at 9, 28 and 35 days post-donation at rates from 2 to 150 mL h−1. Post-pumping samples from these experiments, and a pre-pumping sample in each case, were analysed for levels of potassium and free haemoglobin (Hb). They were also examined microscopically for evidence of cell damage. Potassium levels showed no significant change with pumping on any occasion, but rose significantly as the samples aged. Free Hb showed some variation, but the only consistent finding was a similar rise in value with increasing pack age. Microscopic examination revealed no cell damage under any condition. Both pumps performed to an acceptable level and appear safe to be used for red cell transfusion. [ABSTRACT FROM AUTHOR]

To compare the efficacy of insulin pump treatment with multiple daily injections in the treatment of poorly controlled obese Type 2 diabetic patients already receiving two or more daily injections of insulin plus metformin. Forty obese Type 2 diabetic subjects (using insulin) were randomized to treatment with continuous subcutaneous infusion pump (CSII) (Minimed®) or multiple daily insulin injections (MDI). At the end of the first 18-week treatment period, patients underwent a 12-week washout period during which they were treated with MDI plus metformin. They were then crossed-over to the other treatment for an 18-week follow-up period. Patients performed 4-point daily self blood-glucose monitoring (SBGM) on a regular basis and 7-point monitoring prior to visits 2, 8, 10 and 16. A subset of patients underwent continuous glucose monitoring using the Minimed® continuous glucose monitoring system (CGMS) at visits 2, 8, 10 and 16. A standard meal test was performed in which serum glucose was tested at fasting and once each hour for 6 h following a test meal. Glucose levels were plotted against time and the area under the curve (AUC) was calculated. HbA1c, weight, daily insulin dose and hypoglycaemic episodes were recorded. In obese Type 2 diabetic patients already treated with insulin, treatment with CSII significantly reduced HbA1c levels compared with treatment with MDI. An additional CSII treatment benefit was demonstrated by reduced meal-test glucose AUC. Initial reduction of daily insulin requirement observed in CSII-treated subjects during the first treatment period was attributable to a period effect and did not persist over time. In the intent-to-treat analysis, CSII appeared to be superior to MDI in reducing HbA1c and glucose AUC values without significant change in weight or insulin dose in obese, uncontrolled, insulin-treated Type 2 diabetic subjects. Diabet. Med. 22, 1037–1046 (2005) [ABSTRACT FROM AUTHOR]

Turbo-pumps have weak points, such as when the pumping operation becomes unstable in the rising portion of the head characteristics and/or the cavitation occurs under the intolerably low suction head. To overcome both weak points simultaneously, this article proposes a unique pumping system with counter-rotating mechanism, which consists of two-stage impellers and a peculiar motor with double rotors. The front and the rear impellers are driven by the inner and the outer rotors of the motor, respectively, keeping the relative rotational speed constant and counter-balancing the rotational torque. Such driving conditions not only smartly improve the unstable performance at lower discharge, but also suppress the cavitation at higher discharge, in the optimum cooperation with the impeller works and the rotor outputs. [ABSTRACT FROM AUTHOR]

The meridional flow channel design of a pump impeller affects its performance. However, since so many design parameters exist, a new design method is proposed in which a meridional and blade-to-blade flow channel is designed by the parallel use of the circulation distribution provided by the designer. Thus, an optimization method was used to design an axis-symmetrical meridional flow channel from the circulation distribution. In addition, the inverse design method proposed by Zangeneh et al. (1996) was employed to design a three-dimensional blade-to-blade flow channel from the circulation distribution and the optimized meridional shape. In this article, a few design examples and these Computational Fluid Dynamics (CFD) validations are also given. [ABSTRACT FROM AUTHOR]

In this study we have modeled a high-temperature Root's type compressor and compared predicted results with measurements. Compression process is modeled using multiple control volumes. Initially, there are two control volumes connected by an "expansion nozzle" naturally formed by the rotor tip and the blower casing. The "nozzle" has time-varying geometry and is modeled to allow transition from choked to non-choked flow. The well-filling process is modeled via expansion of the compressed gas from the high-pressure reservoir into the well through this "nozzle." When the pressures in the well and reservoir equalize, the "passive" part of the compression process is taken to be complete. At this point, the gas in the well is assumed to be fully-mixed and the two control volumes are subsequently considered as one. Then the "active" part of compression takes place. Numerical computations are shown to agree well with the experimental data. [ABSTRACT FROM AUTHOR]

Hierarchical algorithms have been developed for enhanced physiologic control and monitoring of blood pumps using pressure inputs. Pressures were measured at pump inlet and outlet using APEX pressure sensors (APSs). The APS is a patented, long-term implantable, flow-through blood pressure sensor and designed to control implantable heart pumps. The algorithms have been tested using a Donavan circulatory mock-loop setup, a generic rotary pump, and LabVIEW software. The hierarchical algorithms control pump speed using pump inlet pressure as a primary independent variable and pump outlet pressure as a secondary dependent variable. Hierarchical control algorithms based on feedback from pressure sensors can control the speed of the pump to stably maintain ventricular filling pressures and arterial pressures. Monitoring algorithms based on pressure inputs are able to approximate flow rate and hydraulic power for the pump and the left ventricle. [ABSTRACT FROM AUTHOR]

xxBackground: Measurement of airborne allergens has hitherto been done with the use of fixed-location pumps or personal air samplers. Our objective was to find out whether ionizers could be good tools for collecting airborne allergens. As a model we have used cat allergen (Fel d 1). We have compared Fel d 1 levels collected by the ionizer at different time periods, as well as comparing Fel d 1 levels obtained with the ionizer with those of low- and high-volume pumps. Methods: Dust samples from floors and air samples collected with ionizers and pumps, obtained in 31 homes with cat, 23 homes without cats, and 28 day-care centres, were analysed for cat allergen content (Fel d 1) by ELISA. Results: Fel d 1 was present in the reservoir in all homes with cats, ranging from 660 to 375000 ng/g (GM 75000) and in the air collected by the ionizer from 2.0 to 204 ng/24 h (GM 19.3). The allergen in homes without cat varied from <55 to 1800 ng/g (GM 166). Corresponding levels in air were found in two of these homes (2.3 and 7.3 ng/24 h). There was a correlation between the number of cats and the amount of airborne cat allergen (r: 0.47; P<0.05). The levels in day-care centres were <55 to 3070 ng/g in dust (GM 360) and <1.1 to 7.9 ng/24 h in the air (GM 1.6). We obtained a moderately strong correlation between air and dust samples in homes with cats (rs: 0.64; P<0.001) and in day-care centres (rs: 0.49; P<0.05). We found that a collection period of 24 h is preferable for the ionizer. The intrahome reliability coefficient was nearly two times higher for the ionizer (r: 0.69) than the pump (r: 0.39). Conclusions: The ionizer seems to be a good tool for monitoring the environment. It is easy to use and silent and does not disturb the airflow in the room. [ABSTRACT FROM AUTHOR]

Fluid delivery from four types of commercially available 50-ml syringes was measured using an electronic balance at an infusion rate of 1 ml.h-1. Retrograde aspiration volume and zero-drug delivery time were recorded after lowering the syringe pump by 50 cm. Syringe compliance was calculated from the volume of bolus released after occlusion at 100 mmHg. Zero-drug delivery times differed significantly between syringes, ranging from [mean (SD)] 3.26 (0.40) min to 6.38 (0.56) min (F = 55.5, d.f. = 3/20, p < 0.0001). Syringe compliance correlated well with aspiration volume (Pearson r2 = 0.92, p < 0.001) and zero-drug delivery time (r2 = 0.90, p < 0.001). Syringe design affected the internal syringe compliance. All syringes were associated with potentially relevant zero-drug delivery times after moderate vertical displacement. To minimise this risk, vertical displacement of syringe pumps delivering highly vasoactive drugs should be avoided. [ABSTRACT FROM AUTHOR]

The Cleveland Clinic continuous flow blood pump is the central element of our innovative ventricular assist system (IVAS). Recent progress has been made in the design/fabrication of a pulsatile mock loop, journal bearing materials testing, and evaluation of a system control algorithm. These results have allowed an acceleration of our program. [ABSTRACT FROM AUTHOR]

The subcellular distribution of the calmodulin-stimulated plasma-membrane Ca2+-ATPase (PMCA) has been studied in rat and rabbit skeletal muscle cells by indirect realmodulin gel overlaysi and direct (Western blotting with specific antibodies) methods. It has also been studied in situ in immunocytochemistry experiments. The distribution of PMCA has been compared with that of the Na+/Ca2+ exchanger and of the dihydropyridine receptor, which has been studied by Western blotting with specific antibodies. Both PMCA and the Na+/Ca2+ exchanger had a dual localizatin, i.e., they were found in the plasma membrane and in the transverse-tubule fractions of the two main types of skeletal muscles studied. The pump and the exchanger were not diffusely distributed in the transverse-tubule-membrane system, but specifically confined to the membrane domain where the dihydropyridine receptor was also localized, i.e., the junctional membrane. Experiments with isoform-specific antibodies have shown that the pump isoform expressed in skeletal muscle is PMCA 1. [ABSTRACT FROM AUTHOR]