Priming Solution Research Articles

GREPHRO: Nature-inspired optimization duo for Internet-of-Things

The optimization techniques usually work with the maximization or minimization of the problem to obtain the local loci or cumulative global loci. Two-dimensional bio-inspired optimization techniques face convexing problems towards a global solution and use an increased number of iterations. Besides, the duality principle considers the dual optimization aspects of the problems leading to a large duality gap of uncertain deviations and optimization errors between any prime solution and its dual solution. Moreover, several problems exist where one objective function requires maximization and another objective function requires minimization using the same set of parameters and some chaining of the feedback process. In such cases, we generally use two different optimization problems as per the best suit to the problem environment and obtain the different sub-solutions of the individual problems. This increases the complexity of the system and often deviates from the original optimal solution. We address these problems of dual optimization in our present work.In this paper, we introduce the first optimization duo model for computing services. To be specific, our proposed model is the first optimization model that works in a dual combined mode with maximization and minimization simultaneously to obtain a global optimum value or loci. We call our model GREen PHotosynthesis and Respiratory-based Optimization (GREPHRO). GREPHRO is primarily motivated by the observation of plants’ photosynthesis and respiratory processes, which work on the same set of environmental variables and have a chaining process. Further, our proposed nature-inspired GREPHRO can value the global optima or infimum point considering a single objective function serving as maximization and minimization combined. GREPHRO uses the Lagrange dual principle and non-linear parameters to obtain a linear solution for the infimum optima. We use a set of experiments on the GREPHRO model in the domain of Wireless Sensor Network (WSN)-based Internet of Thing (IoT) to derive the use case of our proposed work. The experimental results and the comparative analysis with the two of our previous works show that GREPHRO takes fewer iterations with more stability of the optimum solution. Moreover, the computational and memory complexities are also less. Therefore, GREPHRO is efficient and suitable for two-dimensional optimization problems in resource-constrained environments for IoTs.

Medical Mobile Application for The Management of Heart-Lung Machine during Cardiac Surgery

The goal of this work is to construct a mobile application device that has a wide variety of functions which has clinical planning and decision making for heart-lung machine controlling and to assess the users’ level of satisfaction. The app was constructed according to the steps of design, algorithm, and validation, which is based on the ionic framework. The levels of satisfaction with the developed mobile app among 20 perfusionists were assessed by a questionnaire. The project researchers have officially assigned this medical mobile application with the name is Perfusion Assistant app. that can be accessed and used effectively cross platform on iOS and Android. The application is comprised of 5 main categories which includes: a perfusion calculator, myocardial protection chart, drugs details, priming solution, and parameters values. This finding shown that all cardiovascular parameters did not significant differ from Perfusion Assistant app. when compared to manual calculation. User’s satisfaction was at 3.64 ± 0.76 in the first evaluation. After modification with feedback from experts, the satisfaction of this application was evaluated with a 4.13 ± 0.56. Thereby, Perfusion Assistant app. is an application designed in clinical planning and decision of heart-lung machine controlling for perfusionists and medical staff that work in an opened heart surgery arena. Perfusion Assistant app. offers a variety of calculations related to cardiopulmonary bypass including blood flow rate, systemic vascular resistant, priming volume, and predicted hematocrit. Furthermore, Perfusion Assistant app. provides a quick, easy access, and real-time application for cardiopulmonary bypass that user’s satisfaction was a good level.

Seed priming with various chemical agents stimulates the germination and growth attributes synergistically in wheat (Triticum aestivum L.) varieties

Seed priming is a pre-sowing technique that involves the soaking of seeds in water or other solutions to initiate germination and early growth. This study explores the impact of different seed priming solutions on both the germinate on rate and overall performance of the wheat varieties Banganga and Bijaya. The seeds were subjected to different treatments, including polyethylene glycol (PEG) (10 %), boric acid (0.1 %), urea (2 %), polyethylene glycol (PEG) (5 %), ZnSO4 (2 %), MoP (2 %), DAP (2 %), CaCO3 (2 %), and with untreated seeds serving as the control. There was significant variation among the seed priming agents and that they also had a significant effect on the germination percentage, speed of germination, and seedling growth of wheat. CaCO3 (2 %), DAP (2 %), and untreated seeds were found to be the most effective priming solutions, showing superiority in all parameters measured, including shoot length, root length, and fresh weight. Furthermore, Bijaya exhibited higher germination parameters, while Banganga displayed better growth parameters. In conclusion, the findings suggest that using Bijaya with DAP (2 %) or CaCO3 (2 %) as seed priming agents can significantly improve the germination and growth parameters of wheat seedlings. This research sheds light on the potential of various chemical agents applied during seed priming to enhance the germination and growth of two different varieties of wheat.

Methylprednisolone Does Not Enhance Paraoxonase 1 Activity During Cardiopulmonary Bypass Surgery—A Randomized, Controlled Clinical Trial

ObjectivesCardiopulmonary bypass (CPB) is linked to systemic inflammatory responses and oxidative stress. Paraoxonase 1 (PON1) is an antioxidant enzyme with a cardioprotective role, whose activity is decreased in systemic inflammation, and in patients with acute myocardial and global ischemia. Glucocorticoids counteract the effect of oxidative stress by up-regulating PON1 gene expression. We aimed to determine the effect of methylprednisolone on PON1 activity during cardiac surgery on CPB. DesignProspective, randomized, controlled clinical trial. SettingThe study was conducted at the University Medical Centre Ljubljana, Slovenia. Participants40 adult patients, who underwent complex cardiac surgery on CPB between February 2016 and December 2017, were randomized into methylprednisolone and control group (n=20 each). InterventionsPatients in the methylprednisolone group received 1g of methylprednisolone in the CPB priming solution, while patients in the control group were not given methylprednisolone during CPB. Measurements and Main ResultsWe compared the effect of methylprednisolone from CPB priming solution with standard care during CPB on PON1 activity until the 5. postoperative day. Correlations of PON1 activity with lipid status, mediators of inflammation, and hemodynamics were analyzed as well. No significant differences existed between study groups for PON1 activity, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) in any of the measurement intervals (p>0.016). Methylprednisolone group had significantly lower TNF-a (p<0.001), IL-6 (p<0.001), as well as CRP and procalcitonin (p<0.016) after surgery. No significant difference was found between groups for hemodynamic parameters. A positive correlation existed between PON1 and lipid status, whereas a negative correlation was found between PON1 activity and TNF-a, IL-6, as well as CPB duration. ConclusionsMethylprednisolone doesn't influence PON1 activity during cardiac surgery on CPB.

Comparison of six percent hydroxyethyl starch 130/0.4 and ringer's lactate as priming solutions in patients undergoing isolated open heart valve surgery: A double-blind randomized controlled trial.

Colloids are added to the priming solution of the cardiopulmonary bypass (CPB) pump to maintain colloid osmotic pressure and prevent fluid overload. This study aimed to compare the effects of 6% hydroxyethyl starch (HES) 130/0.4 and ringer's lactate (RL) priming solution on patients' outcomes undergoing isolated heart valve surgery with CPB. This randomized clinical trial included one hundred and 20 patients undergoing heart valve surgery, and those were allocated into two groups. Patients in the RL group received 1500mL of RL, and those in the RL + HES group were given 500mL of HES and 1000mL of RL. The patients' median age was 52 (IQR 42-60) and 50 (IQR 40-61) years in the RL + HES and the RL group, respectively (p = .71). The number of cases that required blood product transfusion in both the operating room and intensive care unit was also significantly higher in the RL + HES group compared to the RL group (RR 2.04, 95% CI 1.50-2.76; p < .01 and RR 1.42, 95% CI 1.01-2.01; p = .05, respectively). Declines in postoperative creatinine levels and platelet counts were higher in the RL + HES compared to the RL group (between-subjects effect p = .007 and p = .038, respectively), while the incidence of acute kidney injury was comparable between groups (RR 0.66, 95% CI 0.13-3.30; p = .55). Among patients undergoing heart valve surgery with CPB, 6% HES added to RL for priming compared with only RL increased the risk of the need for blood product transfusion over the hospitalization period.

Development of new colloid osmotic pressure measurement method using ultrafiltration membrane during cardiopulmonary bypass

Background: Clinical practice of measuring colloid osmotic pressure (COP) was abandoned after correcting hypoosmolarity did not improve overall patient outcomes. However, the use of albumin and colloidal solutions has contributed to maintaining intraoperative and postoperative fluid balance at lower levels. Reduced perioperative fluid balance is consistently reported to have positive effects on clinical outcomes. Priming solutions for cardiopulmonary bypass typically include colloids; however, the optimal type of priming solution has not yet been determined. Stricter COP management may further improve postoperative courses. To achieve this, the widespread adoption of a measurement method suitable for COP monitoring during cardiopulmonary bypass is required. Methods: A test circuit was made which measured COP using an ultrafiltration membrane method based on the changes in hydrostatic pressure that occurs across a semipermeable membrane. We then compared the measurements obtained using this method with colloidal osmometer measurements. Results: COP measurements were obtained for a total of 100 tests (10 times each for 10 test solutions). The evaluation parameters included simultaneous reproducibility, correlation with the colloid osmometer, and measurement time. The results demonstrated high accuracy of the ultrafiltration membrane method, simultaneous reproducibility within 3%, a high positive correlation with the colloid osmometer (correlation coefficient: R2 = 0.99; p &lt; 0.01), and equal time required for measurement. Conclusion: Measuring COP using ultrafiltration membranes solves problems within existing measurement methods. Although further improvements in the method are necessary, it has implications for future research and clinical applications.

Effect of Priming on Brassica rapa subsp. chinensis (Bok Choy) Seeds Germination

Brassica rapa subsp. Chinensis, commonly known as Bok Choy, is a nutrient-rich vegetable with substantial antioxidant content. Therefore, this study aimed to evaluate the effect of hydropriming and bio-nutri-priming using Sandwich compost leachate on seed germination, SPAD reading, and dry matter accumulation in 280 dwarf variants of Bok Choy seeds sourced from Green Eagle. The experimental process involved hydropriming with tap water, bio-nutri-priming using 0.2% Sandwich compost leachate, and a control group cultivated in soil without priming. A complete randomization design (CRD) with three replications assessed seed germination performance, SPAD, root and shoot dry matter, and root-to-shoot ratio. While there was no significant difference in the germination percentage (88.35±1.13%), the entire priming seeds exhibited a 2-day peak germination period, compared to 3 days for the non-priming counterparts. Bio-nutri-priming seeds showed faster median and mean germination times due to enhanced nutrient uptake. They further displayed high SPAD readings, suggesting a lack of toxic compounds. The dry matter production of all treated Bok Choy was similar because administered treatments did not interfere with plant growth and development. Therefore, applying bio-nutri-priming using Sandwich compost leachate positively affected seed germination performance, warranting its recommendation as a seeds priming solution.

Hydropriming improves seed germination in horned melon (Cucumis metuliferus E. Mey. Ex Naudin) landraces

The global popularity of horned melon highlights the need of sound crop establishment processes, since uniform and quick seed germination has a substantial influence on crop yield and quality. Using a Completely Randomised Design (CRD) with a factorial structure, the effects of hydro priming durations (0, 8, 16, 24, 32, and 40 h) on seeds of two horned melon landrace (L1&amp;L2) were investigated. Hydro priming had significant (P&gt;0.05) influence on several germination indices (germination percentage, relativized percentage, mean germination rate, germination index, synchronization, duration to 50 % germination, mean daily germination, peak value, and germination value). Among the germination indicators tested, landrace (L2) exhibited a considerably stronger germination response than L1. The findings also reveal a curvilinear relationship between priming length and germination percentage, with 24 hours being greatest proportionately. The mean germination rate, germination index, mean daily germination, peak value of germination, and germination value all rose as the hydro priming duration increased. Primed seeds germinated more quickly than unprimed ones. With increasing priming duration, the synchronization index fell linearly. The interaction between landraces and hydro priming was not significant (P&gt;0.05) for final seed germinated, relativized germination, and synchronization indices, but it had a significant impact on all other indices. Because the efficacy of hydro priming tends to lessen with extended soaking, we recommend using it for a maximum of 32 hours. Future study should concentrate on alternative priming chemicals and the applicability of various priming solutions for various agroecosystems

ON THE DYNAMICS OF A ClASS OF THIRD-ORDER POLYNOMIAL DIFFERENCE EQUATIONS WITH INFINITE NUMBER OF PERIOD-THREE SOLUTIONS

We study the local dynamics and global character of third-order polynomial difference in the first octant of initial conditions with infinite number of prime period-three solutions (three cycles). It is also presented the case when the observed difference equation may be extended to the whole ℝ𝟑.

Effectiveness of Dexmedetomidine as Myocardial Protector in Children With Classic Tetralogy of Fallot Having Corrective Surgery: A Randomized Controlled Trial

ObjectivesEfficacy of dexmedetomidine as cardioprotective agent in Indonesian children undergoing classic tetralogy of Fallot (TOF) repair with cardiopulmonary bypass (CPB). DesignA prospective, parallel trial utilizing block randomization along with double-blinded preparation of treatment agents by other parties. SettingNational Cardiovascular Center Harapan Kita, Indonesia. Participants66 children with classic TOF scheduled for corrective surgery. No children were excluded. All patients had fulfilled criteria for analysis. Interventions0.5 mcg/kg bolus of dexmedetomidine was added in CPB priming solution, followed by 0.25 mcg/kg/hour maintenance during bypass. Placebo group used normal saline. Follow-ups were up to 30 days. Measurement and Main ResultsTroponin I was lower in the dexmedetomidine (Dex) group at 6 hours (30.48± 19.33 vs. 42.73± 27.16, p = 0.039) and 24 hours after CPB (8.89± 5.42 vs. 14.04± 11.17, p = 0.02). Within similar timeframe, Dexmedetomidine successfully lowered IL-6 (p = 0.03; p = 0.035, respectively). Lactate was lower in the Dex group at 1, 6, and 24 hours after CPB (p = <0.01; p = 0.048; p = 0.035, respectively). Dexmedetomidine increased cardiac output and index from 6 hours after bypass, but vice versa in systemic vascular resistance. Reduction of vasoactive inotropic score was seen during ICU monitoring in the Dex group (p = 0.049). Nevertheless, dexmedetomidine did not significantly affect length of ventilation (p = 0.313), ICU stay (p = 0.087), and mortality (p >0.99). ConclusionsDexmedetomidine during CPB is an effective cardioprotective agent in TOF children having surgery. Postoperative mortality was comparable across groups.

Effects of Prolonged Serum Calcium Suppression during Extracorporeal Cardiopulmonary Resuscitation in Pigs.

Controlled reperfusion by monitoring the blood pressure, blood flow, and specific blood parameters during extracorporeal reperfusion after cardiac arrest has the potential to limit ischemia-reperfusion injury. The intracellular calcium overload as part of the ischemia-reperfusion injury provides the possibility for the injury to be counteracted by the early suppression of serum calcium with the aim of improving survival and the neurological outcome. We investigated the effects of prolonged serum calcium suppression via sodium citrate during extracorporeal resuscitation using the CARL protocol (CARL-controlled automated reperfusion of the whole body) compared to a single-dose approach in a porcine model after prolonged cardiac arrest. A control group (N = 10) was resuscitated after a 20 min cardiac arrest, initially lowering the intravascular calcium with the help of a single dose of sodium citrate as part of the priming solution. Animals in the intervention group (N = 13) received additional sodium citrate for the first 15 min of reperfusion. In the control group, 9/10 (90.0%) animals survived until day 7 and 7/13 (53.8%) survived in the intervention group (p = 0.09). A favorable neurological outcome on day 7 after the cardiac arrest was observed in all the surviving animals using a species-specific neurological deficit score. The coronary perfusion pressure was significantly lower with a tendency towards more cardiac arrhythmias in the intervention group. In conclusion, a prolonged reduction in serum calcium levels over the first 15 min of reperfusion after prolonged cardiac arrest tended to be unfavorable regarding survival and hemodynamic variables compared to a single-dose approach in this animal model.

EFFECT OF MANNITOL ON ELECTROLYTES AND ITS RELATION WITH KIDNEY INJURY IN CARDIOPULMONARY BYPASS

The optimal composition of the priming solution used in cardiopulmonary bypass (CPB) during human cardiac surgery is still uncertain. Mannitol is a common component of CPB priming solutions, but its efficacy is debated. To clarify the effect of mannitol on CPB prime solutions, a prospective, randomized, double-blind trial was conducted on 40 patients with sound cardiac and renal functions who were undergoing coronary artery bypass grafting. The trial included two groups: one received Ringer's acetate-based prime (n = 20), and the other received a combination of Ringer's acetate and 200 mL mannitol as prime (n = 20). The study examined changes in renal-related parameters, electrolytes, osmolality, and acid-base balance. Interestingly, no significant differences in osmolality were observed between the Mannitol and Ringer's acetate groups. However, the Mannitol group showed a significant decrease in sodium levels from 138.7±2.8 mmol/L at the start of anesthesia to 133.9±2.6 mmol/L after the initiation of CPB (p &lt;0.001). Renal parameters remained consistent across groups, except for a temporary effect of mannitol on post-surgery urine output (p = 0.003). In conclusion, this study found no significant differences in osmolality between Ringer's acetate-based prime and Mannitol-based prime in individuals with healthy cardiac and renal function. However, the addition of mannitol to the prime resulted in a significant, albeit short-term, reduction in sodium levels. These findings contribute to the ongoing discourse on optimizing CPB prime solutions, especially in cardiac surgical procedures involving mannitol inclusion.

Effect of RMGI Roughness and Dentin Bonding Primer on Shear Bond Strength of Sandwich-type Restorations.

The open sandwich technique is a reliable alternative to amalgam placement in deep proximal box preparations, where proper isolation and enamel bonding may not be possible. It is often difficult to prepare the box for composite placement without affecting the resin-modified glass ionomer (RMGI) that has been placed in the gingival portion. We hypothesized that RMGI surfaces that are roughened or those that use all steps in the manufacturing bonding protocol, including the priming solution, applied before placing a bonded composite increment, would have greater composite/RMGI shear bond strength. Shear bond strengths (SBS) of RMGI tested in the presence and absence of SiC roughening and primer-coating were tested using a fourth-generation dentin bonding agent to composite after thermocycling. Twenty specimens for four test conditions were fabricated and investigated. Data were subjected to a two-way ANOVA and the Holm-Sidak post-hoc test. Placing dentin primer on unabraded RMGI provided a statistically significant improvement in SBS, but only modestly. Furthermore, because bond failure consistently occurred within the RMGI itself, none of the surface modifications have a clinically relevant impact on SBS at the RMGI to the composite interface. Clinicians should be aware that they need not avoid RMGI abrasion and do not need to incorporate all components of a fourth-generation bonding system when covering an RMGI sandwich layer with composite.

Plasmalyte and Ringer Lactate as Priming Solutions in Pediatric Cardiopulmonary Bypass: A Comparative Study

Background: Pediatric heart surgery, particularly for cyanotic congenital heart conditions, commonly requires the utilization of cardiopulmonary bypass (CPB) to assist with surgical interventions. The choice of priming solution for the CPB circuit can influence postoperative outcomes. This study aimed to assess the impact of two different priming solutions, Plasmalyte and Ringer's Lactate, on postoperative outcomes, blood biochemistry, pulmonary and renal function, bleeding, and hemostasis in children undergoing open cardiac surgery with CPB. Methods: This randomized prospective study was conducted on 80 pediatric patients aged 1 to 10 years, undergoing elective cardiac surgery with CPB. Patients were randomly assigned to receive either Plasmalyte (Group A) or Ringer's Lactate (Group B) as their CPB circuit priming solution. Standardized protocols for anesthesia, CPB circuit components, and surgical techniques were maintained. Postoperative parameters including blood chemistry, perfusion indicators, and physiological measurements were recorded and analyzed. Results: After CPB initiation, lactate levels were significantly higher in Group B (Ringer's Lactate) compared to Group A (Plasmalyte) (P-value &lt;0.001). Calcium levels also showed a significant difference between the two groups (P-value &lt;0.001). Postoperative lactate levels remained higher in Group B (P-value &lt;0.001), while bicarbonate, calcium, urine output, urea, and creatinine levels at 6th hour postoperatively were statistically significant (p&lt;0.05). Conclusions: Priming the CPB circuit with Plasmalyte may be associated with favorable outcomes in terms of lactate and calcium levels compared to Ringer Lactate in pediatric patients undergoing cardiac surgery.

Effect of Prime Solutions Used in Coronary Bypass Surgeries on Postoperative Blood Transfusion

Effect of Prime Solutions Used in Coronary Bypass Surgeries on Postoperative Blood Transfusion

Effect of albumin usage during cardiopulmonary bypass on postoperative acute kidney injury in cardiac surgery patients: A historical cohort study.

Acute kidney injury (AKI) after cardiac surgery is a common and serious postoperative complication and is associated with an increased risk of mortality, morbidity, length of hospital stay, and costs. We evaluated the effect of albumin usage on postoperative AKI in patients who underwent on-pump Coronary Artery Bypass Graft Surgery (CABG). This non-randomized cohort study was conducted on data from adult patients who underwent elective CABG, from March of 2015 to March of 2019. We assessed two groups of patients including the albumin (who received 50cc albumin 20% in priming solution) and the non-albumin groups. We recorded demographic data, medical history, and preoperative laboratory data. We compared postoperative changes in serum creatinine (Cr), blood urea nitrogen (BUN), and Glomerular Filtration Rate (GFR) up to 72 hours after surgery with preoperative ones. Also, the stage of kidney dysfunction was assessed according to the AKIN classification. The statistical analysis of the data was processed by SPSS 24 program. Overall, we reviewed 506 patients chart [260 (51.4%) in albumin and 246 (48.6%) in non-albumin group]. In both groups, serum Cr, BUN, and GFR increased in 72 hours postoperatively compared with preoperative levels. This increase was greater in the non-albumin group than in the albumin group. However, the difference was not statistically significant between the two groups (p > 0.05). None of the patients developed renal failure or required dialysis. We concluded that the use of albumin in prime solution did not have a statistically significant effect on postoperative renal dysfunction after CABG.

Utilizing retrograde autologous priming for blood conservation in cardiac surgery.

The use of crystalloid priming for extracorporeal circuit in adult cardiac surgery causes inevitable haemodilution. The haemodilution can be reduced by using methods such as retrograde autologous priming (RAP) with the patient's blood. This study compares the RAP technique with standard priming with regards to safety and the impact on haemodilution. This was a retrospective cohort study between a control group (n = 100) consisting of consecutive patients undergoing first time isolated coronary artery bypass surgery (CABG) with crystalloid priming solution in the circuit, and the RAP group (n = 100) consisting of patients undergoing isolated first time CABG with the RAP method. All demographics, procedure and perfusion data were gathered from the local surgical and perfusion database. Despite starting with comparable mean pre-operative haemoglobin (Hb) levels (control 127 mg/dL versus RAP 129 mg/dL), the RAP group had significantly higher mean post-op Hb level (109 mg/dL versus 92 mg/dL, P < 0.01). Crystalloid use was also significantly lower in RAP group (3.15 L versus 4.17 L P < 0.02). Freedom from red blood cell transfusion (86% versus 76% P = 0.038) and freedom from blood products (78% versus 66%, P = 0.032) was also significantly better in the RAP group. This study demonstrates that retrograde autologous priming is a safe and effective method for priming the cardiopulmonary bypass circuit in adult cardiac surgery, with significantly beneficial effects on transfusion rates and intra operative fluid requirements. Given these results the RAP method should be considered as a routine step in priming an extracorporeal circuit for adult cardiac operations.

Diophantine approximation with prime denominator in real quadratic function fields

In the thirties of the last century, I.M. Vinogradov proved that the inequality ||pα||≤p−1/5+ε has infinitely prime solutions p, where ||.|| denotes the distance to a nearest integer. This result has subsequently been improved by many authors. In particular, Vaughan (1978) replaced the exponent 1/5 by 1/4 using his celebrated identity for the von Mangoldt function and a refinement of Fourier analytic arguments. The current record is due to Matomäki (2009) who showed the infinitude of prime solutions of the inequality ||pα||≤p−1/3+ε. This exponent 1/3 is considered the limit of the current technology. Recently, in [3], the authors established an analogue of Matomäki's result on imaginary quadratic extensions of the function field k=Fq(T). In this paper, we consider the case of real quadratic extensions of k of class number 1, for which we prove a function field analogue of Vaughan's above-mentioned result (exponent θ=1/4). Our method uses versions of Vaughan's identity and the Dirichlet approximation theorem for function fields. The latter was established by Arijit Ganguly in the appendix to our previous paper [3] on the imaginary quadratic case. We also simplify arguments in the paper [1] on the same problem for real quadratic number fields by D. Mazumder and the first-named author.

Charge Estimation of Piezoelectric Actuators: A Comparative Study

This article first reviews the position control of piezoelectric actuators, particularly charge-based sensorless control systems, which often include a charge estimator as a key component. The rest of the paper is about charge estimators for piezoelectric actuators. Two of the most recent/effective types of these estimators utilise either a sensing capacitor (type I in this paper) or a sensing resistor (type II); the latter (and the newer) type is broadly known as a digital charge estimator. Some experimental results in the literature show that, with the same loss in excitation voltage, a considerably higher amount of charge can be estimated with a type II estimator in comparison with a type I estimator; therefore, the superiority of type II estimators was acknowledged. In order to re-assess this conclusion, this paper equitably compares type I and II estimators through analytical modelling and experimentation. The results indicate that type II estimators have only a slight advantage in estimating higher amounts of charge, if both type I and II estimators are designed appropriately. At the same time, type II estimators have disadvantages; e.g., the resistance of type II estimators has to be tuned to suit different excitation frequencies. This research concludes that capacitor-based (type I) charge estimators for piezoelectric actuators, with pertinent design and implementation, can be still the prime solution for many charge estimation problems despite claims in the literature in the last decade.

The Use of Priming Solutions to Scavenge Free Hb and Free Hb Catabolism Byproducts Reduces Hemolysis-Induced Hypertension in Venovenous Extracorporeal Circulation

Extracorporeal circulation procedures often utilize a pump as part of the circuit to drive blood flow, which subjects red blood cells (RBCs) to excessively high shear stresses, resulting in hemolysis and free hemoglobin (Hb). Plasma Hb (pHb) is not stable within the circulation, and can degrade into toxic byproducts, resulting in NO scavenging, vasoconstriction, inflammation, and increased production of reactive oxygen species (ROS). The goal of this study is to determine whether a protein complex containing apohemoglobin and haptoglobin (ApoHb-Hp) can alleviate the sequelae associated with hemolysis induced with a model of venous-venous extracorporeal circulation. Male Golden Syrian hamsters instrumented with window chambers underwent surgery with isoflurane anesthetic to insert two venous cannulas; the drainage cannula was positioned in the inferior vena cava, while the reinfusion cannula was inserted into the left jugular vein. To monitor mean blood pressure (MAP), heart rate (HR), hematocrit (Hct), and pHb, an arterial line was placed into the left carotid artery. After surgery, the animal was heparinized (2.5 IU/g), and the cannulas connected to an extracorporeal circuit consisting of a roller pump and a bubble trap. The circuit was randomly primed with one of three solutions tested: 5% human serum albumin (HSA) solution, ApoHb-Hp complex solution, or a protein solution containing hemopexin (3.05 mg/mL), transferrin (29.3 mg/mL), and haptoglobin (8.25 mg/mL) (protein cocktail). The experimental procedure after surgery lasted a total of 2 hours and was broken down into seven stages. First, baseline measurements were taken after hemodilution by slow infusion of the extracorporeal circuit volume at 0.2 mL/min. Then, the flow rate was ramped up to 50% of the animal’s cardiac output (CO), and maintained at this flow rate for 35 minutes. The flow was then ramped down to 0.2 mL/min, and maintained for an additional 15 minutes to help equilibrate the blood within the animal with that contained in the circuit. Lastly, the flow was stopped for 15 minutes, placing the animal off pump support. Results show that MAP was significantly elevated in the HSA group as compared to the apoHb-Hp group during the ramp up phase, the equilibration phase, and the off pump phase at the end. The MAP for the protein cocktail group was significantly lower than the HSA group at all timepoints after flow rate was ramped up. While an increase in pHb was expected for all groups tested, the protein cocktail group was significantly lower than the HSA group at the end of the ramp up, equilibration, and off-pump phase. Interestingly, the protein cocktail group displayed a significantly lower pHb level when compared to the apoHb-Hp group at the end of the experiment. These results taken in conjunction suggest that the use of Hb and heme scavenging solutions as a priming fluid for extracorporeal circulation procedures can help reduce hemolysis-induced hypertension. This work was supported by funding from NIH/NHLBI grants R01HL162120, R01HL159862. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.